Vocab v28

cultured (bio)

(of tissue cells, bacteria, etc.) grown or propagated in an artificial medium.

what is b12?

Cobalamin Vitamin B₁₂, also known as cobalamin, is a water-soluble vitamin involved in the metabolism of every cell of the human body: it is a cofactor in DNA synthesis, and in both fatty acid and amino acid metabolism.

commissure

a band of nerve tissue connecting the hemispheres of the brain, the two sides of the spinal cord, etc.

viscerotonia

temperament type characterized by love of physical comfort, sociability, tolerance for others, and extroversion a temperament characterized by predominance of social over intellectual and physical traits a pattern of temperament that is marked by predominance of social over intellectual or physical factors and exhibits conviviality, tolerance, complacency, and love of food — compare cerebrotonia, somatotonia.

DDOS

A distributed denial-of-service (DDoS) attack is a malicious attempt to disrupt normal traffic of a targeted server, service or network by overwhelming the target or its surrounding infrastructure with a flood of Internet traffic. In computing, a denial-of-service attack is a cyber-attack in which the perpetrator seeks to make a machine or network resource unavailable to its intended users by temporarily or indefinitely disrupting services of a host connected to the Internet.

roundtable

A group of experts who meet on an equal basis to review and discuss specialized, professional matters, either in closed session or, more frequently, before an audience. a meeting of peers for discussion and exchange of views

kiss of death

A kiss of death is an act of betrayal or any action which causes another's downfall. an action or event that causes certain failure for an enterprise. "it would be the kiss of death for the company if it could be proved that the food was unsafe"

Payload fairing

A payload fairing is a nose cone used to protect a spacecraft against the impact of dynamic pressure and aerodynamic heating during launch through an atmosphere. More recently, an additional function on some flights has been to maintain the cleanroom environment for precision instruments.

speakeasy

A place where alcoholic drinks were sold and consumed illegally during prohibition During the time of Prohibition, people who wanted an alcoholic drink had to visit a speakeasy, or an illegal bar.

viscometer

A viscometer is an instrument used to measure the viscosity of a fluid. ... Viscometers only measure under one flow condition. In general, either the fluid remains stationary and an object moves through it, or the object is stationary and the fluid moves past it. The drag caused by relative motion of the fluid and a surface is a measure of the viscosity. The flow conditions must have a sufficiently small value of Reynolds number for there to be laminar flow.

Epicyclical (Planetary) Gear

An epicyclic gear train consists of two gears mounted so that the centre of one gear revolves around the centre of the other. A carrier connects the centres of the two gears and rotates to carry one gear, called the planet gear or planet pinion, around the other, called the sun gear or sun wheel.

ICBM Rocket

An intercontinental ballistic missile is a guided ballistic missile with a minimum range of 5,500 kilometres primarily designed for nuclear weapons delivery. Similarly, conventional, chemical, and biological weapons can also be delivered with varying effectiveness, but have never been deployed on ICBMs Elon tried to buy three from the russians initially for spacex. They tried to scam him with the high price.

Ground effect

As an airplane nears the ground, the flow over the wing cannot be deflected as far downward as it can in flight away from the ground. The result is that the lift is increased and the induced drag is decreased. In fixed-wing aircraft, ground effect is the increased lift and decreased aerodynamic drag that an aircraft's wings generate when they are close to a fixed surface. When landing, ground effect can give the pilot the feeling that the aircraft is floating.

balancing shaft

Balance shafts are used in piston engines to reduce vibration by cancelling out unbalanced dynamic forces. The balance shafts have eccentric weights and rotate in opposite direction to each other, which generates a net vertical force

DOS

DOS (Disk Operating System) is an operating system that runs from a hard disk drive. The term can also refer to a particular family of disk operating systems, most commonly MS-DOS (Microsoft Disk Operating System).

debt restructuring

Debt restructuring is a process that allows a private or public company or a sovereign entity facing cash flow problems and financial distress to reduce and renegotiate its delinquent debts to improve or restore liquidity so that it can continue its operations. used to receive something instead of nothing

What is the difference between supercapacitor and ultracapacitor?

Discover how the supercapacitor can enhance the battery. The supercapacitor, also known as ultracapacitor or double-layer capacitor, differs from a regular capacitor in that it has very high capacitance. A capacitor stores energy by means of a static charge as opposed to an electrochemical reaction A true "super capacitor" is a low voltage, polarized, DC capacitor that's a cross between a capacitor and a battery, has a capacitance of one to many Farads and can run a DC system for a while in the absence of external power. There's no possible application for one of these in an AC unit.

backhaul network

In a hierarchical telecommunications network, the backhaul portion of the network comprises the intermediate links between the core network, or backbone network, and the small subnetworks at the edge of the network.

ACH Network

In banking, ACH stands for Automated Clearing House, which is a network that coordinates electronic payments and automated money transfers. ACH is a way to move money between banks without using paper checks, wire transfers, credit card networks, or cash.

Born rule

In its simplest form it states that the probability density of finding the particle at a given point is proportional to the square of the magnitude of the particle's wave function at that point. The Born rule is one of the key principles of quantum mechanics.

price inelastic market

Inelastic is an economic term referring to the static quantity of a good or service when its price changes. Inelastic means that when the price goes up, consumers' buying habits stay about the same, and when the price goes down, consumers' buying habits also remain unchanged. Price elasticity of demand is a measure used in economics to show the responsiveness, or elasticity, of the quantity demanded of a good or service to increase in its price when nothing but the price changes.

inconel

It is an alloy of nickel, chromium and iron. Inconel is a family of austenitic nickel-chromium-based superalloys. Inconel alloys are oxidation-corrosion-resistant materials well suited for service in extreme environments subjected to pressure and heat. When heated, Inconel forms a thick, stable, passivating oxide layer protecting the surface from further attack. Inconel alloys are typically used in high temperature applications. SpaceX uses inconel in the engine manifold of their Merlin rocket engine which powers the Falcon 9 launch vehicle. In a first for 3D printing, the SpaceX SuperDraco rocket engine that provides launch escape system and propulsive-landing thrust for the Dragon V2 crew-carrying space capsule is fully printed.

kwaj island

Omelek Island is part of the Kwajalein Atoll in the Republic of the Marshall Islands. It is controlled by the United States military under a long-term lease and is part of the Ronald Reagan Ballistic Missile Defense Test Site. spacex launched from the islands when they first started

why does ozone remove odors?

Ozone removes the smell and odors by reacting and destroying the offensive smelling particulates, molecules, and bacteria. The ozone chemically reacts with them breaking them down into molecules and particulates and bacteria that don't smell Ozone generators work well in removing odors from automobiles, boats and recreational vehicles. They do not mask odors; ozone generators destroy odors, never to return. There are two proven ways to get rid of mold and mildew in your home or office. Ozone generators intentionally produce the toxic gas ozone and are sold as air cleaners for commercial and residential applications. Specifically, they are advertised to deodorize, disinfect, kill or remove dangerous or irritating airborne particles in indoor environments.

skin in the game

Term used when Founders have invested their own cash in the start-up. Looked upon favorably by investors.

Atkinson Cycle

The Atkinson-cycle engine is a type of internal combustion engine invented by James Atkinson in 1882. The Atkinson cycle is designed to provide efficiency at the expense of power density. A modern variation of this approach is used in some modern automobile engines. While originally seen exclusively in hybrid electric applications such as the earlier-generation Toyota Prius, later hybrids and some non-hybrid vehicles now feature engines with variable valve timing, which can run in the Atkinson cycle as a part-time operating regimen, giving good economy while running in Atkinson cycle, and conventional power density when running as a conventional, Otto cycle engine. Atkinson produced three different designs that had a short compression stroke and a longer expansion stroke. The first Atkinson-cycle engine, the differential engine, used opposed pistons. The second and most well-known design, was the cycle engine, which used an over-center arm to create four piston strokes in one crankshaft revolution. The reciprocating engine had the intake, compression, power, and exhaust strokes of the four-stroke cycle in a single turn of the crankshaft, and was designed to avoid infringing certain patents covering Otto-cycle engines.[1] Atkinson's third and final engine, the utilite engine, operated much like any two-stroke engine.

Sarbanes-Oxley Act

The Sarbanes-Oxley Act of 2002 is a federal law that established sweeping auditing and financial regulations for public companies. Lawmakers created the legislation to help protect shareholders, employees and the public from accounting errors and fraudulent financial practices.

translife mission

The Translife Mission is a Mars Society program to determine whether mammals from Earth can live, give birth, and develop properly in Martian gravity. ... The capsule will spin, providing Mars-level gravity to its inhabitants

Why do some engines sound different even through the engine is the same in both cars?

The cylinder firing order is different.

low polar moment of inertia

The farther away from the axis of rotation the mass is, the harder it is to make it turn. Conversely, if the mass is concentrated near the centre, it is easier to make it turn. Mid engine cars have a low polar moment of inertia which makes it easier to make them rotate, and therefore easier for them to turn.

Firing order

The firing order of an internal combustion engine is the sequence of ignition for the cylinders. In a spark ignition (e.g. gasoline/petrol) engine, the firing order corresponds to the order in which the spark plugs are operated. In a Diesel engine, the firing order corresponds to the order in which fuel is injected into each cylinder. Firing order affects the vibrations, sound and evenness of power output from the engine. The firing order heavily influences crankshaft design. Formula: Strokes(180) / number of cylinders 4 (180) / 5 = 144° firing interval 5 cylinders / 360° in circle = 72° per cylinder so after 144° another cylinder will fire making the firing order 12453

Are 8 speed transmissions good?

The highly efficient 8 speed transmission comes with many benefits to the consumer. The first and most sought after benefit is the increase in fuel efficiency. It can improve fuel economy 11% compared the older 6 speed transmission and up to 14% compared to modern 5 speed transmissions. The purpose of a transmission is to provide power to the wheels at the proper rate based on the speed you are driving. It starts in a low gear to allow the vehicle to get going, then it shifts into higher gears to accommodate for the wheels moving faster at higher rates of speed

Tom Mueller

Thomas Mueller is an American rocket engineer and rocket engine designer. He is a founding employee of SpaceX, a space transport services company headquartered in Hawthorne, California. He is best known for his engineering work on the TR-106, the Dragon spacecraft propulsion, and Merlin Rocket Engines.

Elon musk on patents

When I started out with my first company, Zip2, I thought patents were a good thing and worked hard to obtain them. And maybe they were good long ago, but too often these days they serve merely to stifle progress, entrench the positions of giant corporations and enrich those in the legal profession, rather than the actual inventors. After Zip2, when I realized that receiving a patent really just meant that you bought a lottery ticket to a lawsuit, I avoided them whenever possible. At Tesla, however, we felt compelled to create patents out of concern that the big car companies would copy our technology and then use their massive manufacturing, sales and marketing power to overwhelm Tesla. We couldn't have been more wrong. The unfortunate reality is the opposite: electric car programs (or programs for any vehicle that doesn't burn hydrocarbons) at the major manufacturers are small to non-existent, constituting an average of far less than 1% of their total vehicle sales. At best, the large automakers are producing electric cars with limited range in limited volume. Some produce no zero emission cars at all. Given that annual new vehicle production is approaching 100 million per year and the global fleet is approximately 2 billion cars, it is impossible for Tesla to build electric cars fast enough to address the carbon crisis. By the same token, it means the market is enormous. Our true competition is not the small trickle of non-Tesla electric cars being produced, but rather the enormous flood of gasoline cars pouring out of the world's factories every day.

see this through

[see something through] to continue doing something until it is finished, especially something unpleasant or difficult. Having come this far, she was determined to see things through.

overdraft

a deficit in a bank account caused by drawing more money than the account holds.

split brain

a condition resulting from surgery that isolates the brain's two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them They are experiments done in those who have their corpus callosum cut apart. These bundle of fibers are how the left and right hemispheres of the brain communicate and distance from each other. These split-brain experiments have discovered that many cognitive and affective processes are lateralized in the hemispheres. In a nutshell, these are the results from various experiments in how the hemispheres specialize in functions in general. Note that the left brain and right brain personality idea is a myth and oversimplification of brain lateralization. Left Hemisphere: Abstract/Conceptual Cogniton Denotative Language Semantic (Generic) Memory Atomistic Processing Narrowing of Attention Right Hemisphere: Concrete/Perceptual Cognition Connotative Language and Meaning Episodic (Context-Specific) Memory Gestalt Awareness Broadening and Sustaining of Attention Facial Recognition and Expression. In the first months after her surgery, shopping for groceries was infuriating. Standing in the supermarket aisle, Vicki would look at an item on the shelf and know that she wanted to place it in her trolley — but she couldn't. "I'd reach with my right for the thing I wanted, but the left would come in and they'd kind of fight," she says. "Almost like repelling magnets." Picking out food for the week was a two-, sometimes three-hour ordeal. Getting dressed posed a similar challenge: Vicki couldn't reconcile what she wanted to put on with what her hands were doing. Sometimes she ended up wearing three outfits at once. "I'd have to dump all the clothes on the bed, catch my breath and start again." In one crucial way, however, Vicki was better than her pre-surgery self. She was no longer racked by epileptic seizures that were so severe they had made her life close to unbearable. She once collapsed onto the bar of an old-fashioned oven, burning and scarring her back. "I really just couldn't function," she says. When, in 1978, her neurologist told her about a radical but dangerous surgery that might help, she barely hesitated. If the worst were to happen, she knew that her parents would take care of her young daughter. "But of course I worried," she says. "When you get your brain split, it doesn't grow back together." But what Vicki could never have known was that her surgery would turn her into an accidental superstar of neuroscience. She is one of fewer than a dozen 'split-brain' patients, whose brains and behaviours have been subject to countless hours of experiments, hundreds of scientific papers, and references in just about every psychology textbook of the past generation. And now their numbers are dwindling. Through studies of this group, neuroscientists now know that the healthy brain can look like two markedly different machines, cabled together and exchanging a torrent of data. But when the primary cable is severed, information — a word, an object, a picture — presented to one hemisphere goes unnoticed in the other. Michael Gazzaniga, a cognitive neuroscientist at the University of California, Santa Barbara, and the godfather of modern split-brain science, says that even after working with these patients for five decades, he still finds it thrilling to observe the disconnection effects first-hand. "You see a split-brain patient just doing a standard thing — you show him an image and he can't say what it is. But he can pull that same object out of a grab-bag," Gazzaniga says. "Your heart just races!" Work with the patients has teased out differences between the two hemispheres, revealing, for instance, that the left side usually leads the way for speech and language computation, and the right specializes in visual-spatial processing and facial recognition. "The split work really showed that the two hemispheres are both very competent at most things, but provide us with two different snapshots of the world," says Richard Ivry, director of the Institute of Cognitive and Brain Sciences at the University of California, Berkeley. The idea of dichotomous consciousness captivated the public, and was greatly exaggerated in the notion of the 'creative right brain'. But further testing with split-brain patients gave a more-nuanced picture. The brain isn't like a computer, with specific sections of hardware charged with specific tasks. It's more like a network of computers connected by very big, busy broadband cables. The connectivity between active brain regions is turning out to be just as important, if not more so, than the operation of the distinct parts. "With split-brain patients, you can see the impact of disconnecting a huge portion of that network, but without damage to any particular modules," says Michael Miller, a psychologist at the University of California, Santa Barbara.

board of directors

a group of persons elected by the stockholders to manage a corporation A board of directors is a team of people elected by a corporation's shareholders to represent the shareholders' interests and ensure that the company's management acts on their behalf. The head of the board of directors is the chairman or chairperson of the board. In general, the board makes decisions as a fiduciary on behalf of shareholders. ... In addition to those duties, a board of directors is responsible for helping a corporation set broad goals, supporting executive duties, and ensuring the company has adequate, well-managed resources at its disposal.

Summary judgment

a judgment decided by a trial court without that case going to trial; a summary judgment is an attempt to stop a case from going to trial

magic bullet

a medicine or other remedy, especially an undiscovered or hypothetical one, with wonderful or highly specific properties. "there's no magic bullet, and we should just try to eat as varied and well-balanced a diet as possible"

agonist

a molecule that increases a neurotransmitter's action a molecule that, by binding to a receptor site, stimulates a response (biochemistry) a drug that can combine with a receptor on a cell to produce a physiological reaction

pushback

a negative or unfavorable reaction or response.

once-over

a rapid inspection or search. a piece of work that is done quickly.

Rocker arm

a rocking lever in an engine, especially one in an internal combustion engine that serves to work a valve and is operated by a pushrod from the camshaft. A rocker arm is an oscillating lever that conveys radial movement from the cam lobe into linear movement at the poppet valve to open it. One end is raised and lowered by a rotating lobe of the camshaft while the other end acts on the valve stem.

rocker arm

a rocking lever in an engine, especially one in an internal combustion engine that serves to work a valve and is operated by a pushrod from the camshaft. located on camshaft

diddly

a thing of little or no value a small worthless amount

in good faith

absence of knowledge of any defects or problems Honesty; a sincere intention to deal fairly with others. honesty or sincerity of intention. "the details contained in this brochure have been published in good faith"

newfound

adj. newly discovered or found

shell-shocked

affected with a nervous or mental disorder resulting from the strain of battle shocked or confused because of a sudden alarming experience.

mono

an acute disease characterized by fever and swollen lymph nodes and an abnormal increase of mononuclear leukocytes or monocytes in the bloodstream; not highly contagious; some believe it can be transmitted by kissing Mononucleosis is an infectious illness that's usually caused by the Epstein-Barr virus (EBV). It's also called mono or "the kissing disease." You can get the virus through kissing as well as things like sharing drinks or silverware

a siren song

an alluring utterance or appeal, especially one that is seductive or deceptive

gleam in his eye

an expression in your eyes that shows that you are amused or that you have a secret: "I can't tell you that yet, but I will soon,"

Central bank

an institution designed to oversee the banking system and regulate the quantity of money in the economy A central bank, reserve bank, or monetary authority is an institution that manages the currency, money supply, and interest rates of a state or formal monetary union, and oversees their commercial banking system. The Federal Reserve System is the central banking system of the United States of America. It was created on December 23, 1913, with the enactment of the Federal Reserve Act, after a series of financial panics led to the desire for central control of the monetary system in order to alleviate financial crises.

Atoll

an island consisting of a circular coral reef surrounding a lagoon

enamel

an opaque or semi transparent glassy substance applied to metallic or other hard surfaces for ornament or as a protective coating.

hag

an ugly evil-looking old woman A hag is a witch, or a witch-like old woman. Many fairy tales include a hag as a frightening character.

bernoulli effect

as the velocity of airflow increases, pressure decreases with total energy remaining constant In fluid dynamics, Bernoulli's principle states that an increase in the speed of a fluid occurs simultaneously with a decrease in static pressure or a decrease in the fluid's potential energy.

IVF

in vitro fertilization a medical procedure whereby an egg is fertilized by sperm in a test tube or elsewhere outside the body. First, you take medication that makes several of your eggs mature and ready for fertilization. Then the doctor takes the eggs out of your body and mixes them with sperm in a lab, to help the sperm fertilize the eggs. Then they put 1 or more fertilized eggs (embryos) directly into your uterus. Pregnancy happens if any of the embryos implant in the lining of your uterus. IVF has many steps, and it takes several months to complete the whole process. It sometimes works on the first try, but many people need more than 1 round of IVF to get pregnant. IVF definitely increases your chances of pregnancy if you're having fertility problems, but there's no guarantee — everyone's body is different and IVF won't work for everyone.

IUD

intrauterine device; contraceptive birth control implant The copper in the IUD prevents sperm from surviving, and alters your cervical mucus to prevent sperm from reaching an egg. An IUD may also work by stopping a fertilised egg from implanting in the uterus. An IUD doesn't cause an abortion. The Mirena is a levonorgestrel (progestin)-releasing intrauterine system, which is an estrogen-free device that delivers small amounts of hormone directly into the uterus. As a result, the hormone level is almost undetectable in the bloodstream as it is concentrated right in the uterus to help protect against pregnancy. The Mirena provides lower and more balanced hormones than the pill. The Mirena, made of soft flexible plastic, is inserted into the uterus during an office visit. It is good for five years, is 99.9% successful in preventing pregnancy and is easily removed when you wish it to be.

leveraging

investing with borrowed money as a way to amplify potential gains (at the risk of greater losses)

unceremonious

lacking proper formality; abrupt without ceremony or formality

enzyme inhibitors

substrate imposters that plug up the active site Enzyme inhibitors are substances which alter the catalytic action of the enzyme and consequently slow down, or in some cases, stop catalysis. There are three common types of enzyme inhibition - competitive, non-competitive and substrate inhibition. Examples of slow-binding inhibitors include some important drugs, such methotrexate, allopurinol, and the activated form of acyclovir. Many therapeutic drugs are enzyme inhibitors. Important examples are penicillin, which inhibits an enzyme necessary for bacterial cell wall synthesis , A computer image of the structure of a protease inhibitor.

yank my chain

tease someone by leading them to believe something untrue.

a cool welcome

the act of greeting or receiving a person or thing; reception the new theory had a cool welcome. wear out one's welcome to come more often or stay longer than is acceptable or pleasing.

trigonometry

the branch of mathematics dealing with the relations of the sides and angles of triangles and with the relevant functions of any angles.

antipode

the direct opposite of something else

corpus callosum

the large band of neural fibers connecting the two brain hemispheres and carrying messages between them They are experiments done in those who have their corpus callosum cut apart. These bundle of fibers are how the left and right hemispheres of the brain communicate and distance from each other. These split-brain experiments have discovered that many cognitive and affective processes are lateralized in the hemispheres.

firm

the members of a business organization that owns or operates one or more establishments

hold dear

to be fond of, to love; cherish

hand over fist

very rapidly

1 horsepower (hp) = 2,545 btu per hour (btu/h) 1 horsepower is equivalent to 746 watts. So if you took a 1-horsepower horse and put it on a treadmill, it could operate a generator producing a continuous 746 watts. 1 horsepower (over the course of an hour) is equivalent to 2,545 BTU (British thermal units). If you took that 746 watts and ran it through an electric heater for an hour, it would produce 2,545 BTU (where a BTU is the amount of energy needed to raise the temperature of 1 pound of water 1 degree F). One BTU is equal to 1,055 joules, or 252 gram-calories or 0.252 food Calories. Presumably, a horse producing 1 horsepower would burn 641 Calories in one hour if it were 100-percent efficient.

/

No matter how bad of a situation you are in, it can always get worse.

/

i've been there. at some point in one of my relationships i came to the realization that i wasn't in love with her; i was in love with the idea that she cared about me.

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Differential car purpose

- To aim the engine power at the wheels - To act as the final gear reduction in the vehicle, slowing the rotational speed of the transmission one final time before it hits the wheels - To transmit the power to the wheels while allowing them to rotate at different speeds (This is the one that earned the differential its name.) Car wheels spin at different speeds, especially when turning. You can see from the animation that each wheel travels a different distance through the turn, and that the inside wheels travel a shorter distance than the outside wheels. Since speed is equal to the distance traveled divided by the time it takes to go that distance, the wheels that travel a shorter distance travel at a lower speed. Also note that the front wheels travel a different distance than the rear wheels. For the non-driven wheels on your car -- the front wheels on a rear-wheel drive car, the back wheels on a front-wheel drive car -- this is not an issue. There is no connection between them, so they spin independently. But the driven wheels are linked together so that a single engine and transmission can turn both wheels. If your car did not have a differential, the wheels would have to be locked together, forced to spin at the same speed. This would make turning difficult and hard on your car: For the car to be able to turn, one tire would have to slip. With modern tires and concrete roads, a great deal of force is required to make a tire slip. That force would have to be transmitted through the axle from one wheel to another, putting a heavy strain on the axle components. The differential is found on all modern cars and trucks, and also in many all-wheel-drive (full-time four-wheel-drive) vehicles. These all-wheel-drive vehicles need a differential between each set of drive wheels, and they need one between the front and the back wheels as well, because the front wheels travel a different distance through a turn than the rear wheels. Note that the input pinion is a smaller gear than the ring gear; this is the last gear reduction in the car. You may have heard terms like rear axle ratio or final drive ratio. These refer to the gear ratio in the differential. If the final drive ratio is 4.10, then the ring gear has 4.10 times as many teeth as the input pinion gear. When a car makes a turn, the wheels must spin at different speeds. Another time open differentials might get you into trouble is when you are driving off-road. If you have a four-wheel drive truck, or an SUV, with an open differential on both the front and the back, you could get stuck. Now, remember -- as we mentioned on the previous page, the open differential always applies the same torque to both wheels. If one of the front tires and one of the back tires comes off the ground, they will just spin helplessly in the air, and you won't be able to move at all. The solution to these problems is the limited slip differential (LSD), sometimes called positraction. Limited slip differentials use various mechanisms to allow normal differential action when going around turns. When a wheel slips, they allow more torque to be transferred to the non-slipping wheel. The clutch-type LSD is probably the most common version of the limited slip differential This type of LSD has all of the same components as an open differential, but it adds a spring pack and a set of clutches. Some of these have a cone clutch that is just like the synchronizers in a manual transmission. The spring pack pushes the side gears against the clutches, which are attached to the cage. Both side gears spin with the cage when both wheels are moving at the same speed, and the clutches aren't really needed -- the only time the clutches step in is when something happens to make one wheel spin faster than the other, as in a turn. The clutches fight this behavior, wanting both wheels to go the same speed. If one wheel wants to spin faster than the other, it must first overpower the clutch. The stiffness of the springs combined with the friction of the clutch determine how much torque it takes to overpower it. Getting back to the situation in which one drive wheel is on the ice and the other one has good traction: With this limited slip differential, even though the wheel on the ice is not able to transmit much torque to the ground, the other wheel will still get the torque it needs to move. The torque supplied to the wheel not on the ice is equal to the amount of torque it takes to overpower the clutches. The result is that you can move forward, although still not with the full power of your car. The viscous coupling is often found in all-wheel-drive vehicles. It is commonly used to link the back wheels to the front wheels so that when one set of wheels starts to slip, torque will be transferred to the other set. The viscous coupling has two sets of plates inside a sealed housing that is filled with a thick fluid, as shown in below. One set of plates is connected to each output shaft. Under normal conditions, both sets of plates and the viscous fluid spin at the same speed. When one set of wheels tries to spin faster, perhaps because it is slipping, the set of plates corresponding to those wheels spins faster than the other. The viscous fluid, stuck between the plates, tries to catch up with the faster disks, dragging the slower disks along. This transfers more torque to the slower moving wheels -- the wheels that are not slipping. When a car is turning, the difference in speed between the wheels is not as large as when one wheel is slipping. The faster the plates are spinning relative to each other, the more torque the viscous coupling transfers. The coupling does not interfere with turns because the amount of torque transferred during a turn is so small. However, this also highlights a disadvantage of the viscous coupling: No torque transfer will occur until a wheel actually starts slipping. A simple experiment with an egg will help explain the behavior of the viscous coupling. If you set an egg on the kitchen table, the shell and the yolk are both stationary. If you suddenly spin the egg, the shell will be moving at a faster speed than the yolk for a second, but the yolk will quickly catch up. To prove that the yolk is spinning, once you have the egg spinning quickly stop it and then let go -- the egg will start to spin again (unless it is hard boiled). In this experiment, we used the friction between the shell and the yolk to apply force to the yolk, speeding it up. When we stopped the shell, that friction -- between the still-moving yolk and the shell -- applied force to the shell, causing it to speed up. In a viscous coupling, the force is applied between the fluid and the sets of plates in the same way as between the yolk and the shell. The locking differential is useful for serious off-road vehicles. This type of differential has the same parts as an open differential, but adds an electric, pneumatic or hydraulic mechanism to lock the two output pinions together. This mechanism is usually activated manually by switch, and when activated, both wheels will spin at the same speed. If one wheel ends up off the ground, the other wheel won't know or care. Both wheels will continue to spin at the same speed as if nothing had changed. The Torsen differential* is a purely mechanical device; it has no electronics, clutches or viscous fluids. The Torsen (from Torque Sensing) works as an open differential when the amount of torque going to each wheel is equal. As soon as one wheel starts to lose traction, the difference in torque causes the gears in the Torsen differential to bind together. The design of the gears in the differential determines the torque bias ratio. For instance, if a particular Torsen differential is designed with a 5:1 bias ratio, it is capable of applying up to five times more torque to the wheel that has good traction. These devices are often used in high-performance all-wheel-drive vehicles. Like the viscous coupling, they are often used to transfer power between the front and rear wheels. In this application, the Torsen is superior to the viscous coupling because it transfers torque to the stable wheels before the actual slipping occurs. However, if one set of wheels loses traction completely, the Torsen differential will be unable to supply any torque to the other set of wheels. The bias ratio determines how much torque can be transferred, and five times zero is zero. The HMMWV, or Hummer, uses Torsen® differentials on the front and rear axles. The owner's manual for the Hummer proposes a novel solution to the problem of one wheel coming off the ground: Apply the brakes. By applying the brakes, torque is applied to the wheel that is in the air, and then five times that torque can go to the wheel with good traction.

bevel gear

Bevel gears are useful when the direction of a shaft's rotation needs to be changed. They are usually mounted on shafts that are 90 degrees apart, but can be designed to work at other angles as well. This feature is used in many car differentials. The ring gear of the differential and the input pinion gear are both hypoid

displacement per cylinder

Engines are measured by displacement, usually expressed in liters (L) or cubic centimeters (cc). Displacement is the total volume of all the cylinders in an engine. An engine with four cylinders of 569cc each totals 2276cc, and will be rounded off and referred to as a 2.3 liter engine.

rotary engine

Crucial to Industrial revolution, it could pump water from a mine efficiently. Invented by James Watt in 1784. The rotary engine was an early type of internal combustion engine, usually designed with an odd number of cylinders per row in a radial configuration, in which the crankshaft remained stationary in operation, with the entire crankcase and its attached cylinders rotating around it as a unit.

How Diesel Engines Work

In 1878, Rudolf Diesel was attending the Polytechnic High School of Germany (the equivalent of an engineering college) when he learned about the low efficiency of gasoline and steam engines. This disturbing information inspired him to create an engine with a higher efficiency, and he devoted much of his time to developing a "Combustion Power Engine." By 1892 Diesel had obtained a patent for what we now call the diesel engine. In theory, diesel engines and gasoline engines are quite similar. They are both internal combustion engines designed to convert the chemical energy available in fuel into mechanical energy. This mechanical energy moves pistons up and down inside cylinders. The pistons are connected to a crankshaft, and the up-and-down motion of the pistons, known as linear motion, creates the rotary motion needed to turn the wheels of a car forward. Both diesel engines and gasoline engines convert fuel into energy through a series of small explosions or combustions. The major difference between diesel and gasoline is the way these explosions happen. In a gasoline engine, fuel is mixed with air, compressed by pistons and ignited by sparks from spark plugs. In a diesel engine, however, the air is compressed first, and then the fuel is injected. Because air heats up when it's compressed, the fuel ignites. Remember that the diesel engine has no spark plug, that it intakes air and compresses it, and that it then injects the fuel directly into the combustion chamber (direct injection). It is the heat of the compressed air that lights the fuel in a diesel engine. When working on his calculations, Rudolf Diesel theorized that higher compression leads to higher efficiency and more power. This happens because when the piston squeezes air with the cylinder, the air becomes concentrated. Diesel fuel has a high energy content, so the likelihood of diesel reacting with the concentrated air is greater. Another way to think of it is when air molecules are packed so close together, fuel has a better chance of reacting with as many oxygen molecules as possible. Rudolf turned out to be right — a gasoline engine compresses at a ratio of 8:1 to 12:1, while a diesel engine compresses at a ratio of 14:1 to as high as 25:1. One big difference between a diesel engine and a gas engine is in the injection process. Most car engines use port injection or a carburetor. A port injection system injects fuel just prior to the intake stroke (outside the cylinder). A carburetor mixes air and fuel long before the air enters the cylinder. In a car engine, therefore, all of the fuel is loaded into the cylinder during the intake stroke and then compressed. The compression of the fuel/air mixture limits the compression ratio of the engine -- if it compresses the air too much, the fuel/air mixture spontaneously ignites and causes knocking. Because it causes excessive heat, knocking can damage the engine. Some diesel engines contain a glow plug. When a diesel engine is cold, the compression process may not raise the air to a high enough temperature to ignite the fuel. The glow plug is an electrically heated wire (think of the hot wires you see in a toaster) that heats the combustion chambers and raises the air temperature when the engine is cold so that the engine can start. All functions in a modern engine are controlled by the ECM communicating with an elaborate set of sensors measuring everything from R.P.M. to engine coolant and oil temperatures and even engine position (i.e. T.D.C.). Glow plugs are rarely used today on larger engines. The ECM senses ambient air temperature and retards the timing of the engine in cold weather so the injector sprays the fuel at a later time. The air in the cylinder is compressed more, creating more heat, which aids in starting. Smaller engines and engines that do not have such advanced computer control use glow plugs to solve the cold-starting problem. Diesel fuel has a higher energy density than gasoline. On average, 1 gallon (3.8 L) of diesel fuel contains approximately 155x106 joules (147,000 BTU), while 1 gallon of gasoline contains 132x106 joules (125,000 BTU). This, combined with the improved efficiency of diesel engines, explains why diesel engines get better mileage than equivalent gasoline engines.

torque converter

In an automatic transmission, this automatically varies the amount of torque supplied automatically shifts the amount of torque used according to what is needed In brief, the torque converter is a type of fluid coupling, which allows the engine to spin somewhat independently of the transmission. It is responsible for pressurizing automatic transmission fluid, a pressurization that supplies the force necessary to shift transmission gears. If you've read about manual transmissions, you know that an engine is connected to a transmission by way of a clutch. Without this connection, a car would not be able to come to a complete stop without killing the engine. But cars with an automatic transmission have no clutch that disconnects the transmission from the engine. Instead, they use an amazing device called a torque converter. It may not look like much, but there are some very interesting things going on inside. A torque converter is a type of fluid coupling, which allows the engine to spin somewhat independently of the transmission. If the engine is turning slowly, such as when the car is idling at a stoplight, the amount of torque passed through the torque converter is very small, so keeping the car still requires only a light pressure on the brake pedal. If you were to step on the gas pedal while the car is stopped, you would have to press harder on the brake to keep the car from moving. This is because when you step on the gas, the engine speeds up and pumps more fluid into the torque converter, causing more torque to be transmitted to the wheels. The housing of the torque converter is bolted to the flywheel of the engine, so it turns at whatever speed the engine is running at. The fins that make up the pump of the torque converter are attached to the housing, so they also turn at the same speed as the engine. The cutaway below shows how everything is connected inside the torque converter. The pump inside a torque converter is a type of centrifugal pump. As it spins, fluid is flung to the outside, much as the spin cycle of a washing machine flings water and clothes to the outside of the wash tub. As fluid is flung to the outside, a vacuum is created that draws more fluid in at the center. The fluid then enters the blades of the turbine, which is connected to the transmission. The turbine causes the transmission to spin, which basically moves your car. You can see in the graphic below that the blades of the turbine are curved. This means that the fluid, which enters the turbine from the outside, has to change direction before it exits the center of the turbine. It is this directional change that causes the turbine to spin. In order to change the direction of a moving object, you must apply a force to that object -- it doesn't matter if the object is a car or a drop of fluid. And whatever applies the force that causes the object to turn must also feel that force, but in the opposite direction. So as the turbine causes the fluid to change direction, the fluid causes the turbine to spin. The fluid exits the turbine at the center, moving in a different direction than when it entered. If you look at the arrows in the figure above, you can see that the fluid exits the turbine moving opposite the direction that the pump (and engine) are turning. If the fluid were allowed to hit the pump, it would slow the engine down, wasting power. This is why a torque converter has a stator. The stator resides in the very center of the torque converter. Its job is to redirect the fluid returning from the turbine before it hits the pump again. This dramatically increases the efficiency of the torque converter. The stator has a very aggressive blade design that almost completely reverses the direction of the fluid. A one-way clutch (inside the stator) connects the stator to a fixed shaft in the transmission (the direction that the clutch allows the stator to spin is noted in the figure above). Because of this arrangement, the stator cannot spin with the fluid -- it can spin only in the opposite direction, forcing the fluid to change direction as it hits the stator blades. Something a little bit tricky happens when the car gets moving. There is a point, around 40 mph (64 kph), at which both the pump and the turbine are spinning at almost the same speed (the pump always spins slightly faster). At this point, the fluid returns from the turbine, entering the pump already moving in the same direction as the pump, so the stator is not needed. Even though the turbine changes the direction of the fluid and flings it out the back, the fluid still ends up moving in the direction that the turbine is spinning because the turbine is spinning faster in one direction than the fluid is being pumped in the other direction. If you were standing in the back of a pickup moving at 60 mph, and you threw a ball out the back of that pickup at 40 mph, the ball would still be going forward at 20 mph. This is similar to what happens in the turbine: The fluid is being flung out the back in one direction, but not as fast as it was going to start with in the other direction. At these speeds, the fluid actually strikes the back sides of the stator blades, causing the stator to freewheel on its one-way clutch so it doesn't hinder the fluid moving through it. In addition to the very important job of allowing your car come to a complete stop without stalling the engine, the torque converter actually gives your car more torque when you accelerate out of a stop. Modern torque converters can multiply the torque of the engine by two to three times. This effect only happens when the engine is turning much faster than the transmission. At higher speeds, the transmission catches up to the engine, eventually moving at almost the same speed. Ideally, though, the transmission would move at exactly the same speed as the engine, because this difference in speed wastes power. This is part of the reason why cars with automatic transmissions get worse gas mileage than cars with manual transmissions. To counter this effect, some cars have a torque converter with a lockup clutch. When the two halves of the torque converter get up to speed, this clutch locks them together, eliminating the slippage and improving efficiency.

Guantanamo Bay

Military base granted to the US in Cuba which is now used as a prison It is a converted military prison used by the US government to un-constitutionally evade the mandates for fair treatment and protection of human Rights enshrined in Our Constitution. Something of which USA should be very ashamed and for which people should be prosecuted, including for the crime of torture. It is a gulag with regular and horrific torture, holding hundreds of innocent men in appalling conditions.

oil cycle in IC engine

Oil is vacuum pulled through the strainer in the bottom of the sump. It them passes through the pump, into an oil pressure regulator and then though the oil filter to remove impurities. It then makes its way to the crankshaft, cylinders, and camshaft. The oil is sprayed onto this components via small orifice spouts. It then will eventually make its way back to the sump and the cycle will repeat.

anesthesia awareness

Phenomenon of patients being partially awake while under general anesthesia consciousness without movement

torque converter vs clutch pad

Torque converters are used on automatic transmissions in place of a clutch pad which is used on a manual transmission.

Michel engine

The Michel engine was an unusual form of opposed-piston engine. It was unique in that its cylinders, instead of being open-ended cylinders containing two pistons, were instead joined in a Y-shape and had three pistons working within them. The Michel engine was a two-stroke diesel engine, of piston-ported opposed-piston design. Its unusual feature was that rather than two pistons sharing a cylinder, the cylinders here were Y shaped and contained three pistons. The two upper pistons controlled the inlet ports, with the one lower piston controlling the exhaust ports. Having two inlet (scavenge air) pistons to one exhaust piston provided good scavenging and efficient combustion. The engine was water-cooled. Early versions of the Michel engine were cam engines. These do not use a crankshaft in the conventional sense, but instead have a shaped cam. The pistons or their connecting rods have cam followers that slide over the surface of this cam. Although most cams use rotary motion to generate a linear motion, this 'crankshaft' use is also possible, where the linear motion of the pistons is used to drive the rotary motion of the cam and the engine's output shaft.

breach of contract

The failure, without legal excuse, of a promisor to perform the obligations of a contract. the nonperformance of a contractual duty A failure to perform, as promised, at the time the performance was due.

You mentioned steam engines in this article — are there any advantages to steam engines and other external combustion engines?

The main advantage of a steam engine is that you can use anything that burns as the fuel. For example, a steam engine can use coal, newspaper or wood for the fuel, while an internal combustion engine needs pure, high-quality liquid or gaseous fuel.

prime meridian

The meridian, designated at 0° longitude, which passes through the Royal Observatory at Greenwich, England.

gear ratio

The ratio of the speed of the driving member of a gear train to that of the driven member. On any gear, the ratio is determined by the distances from the center of the gear to the point of contact. For instance, in a device with two gears, if one gear is twice the diameter of the other, the ratio would be 2:1.

How does an IC engine work?

The purpose of a gasoline car engine is to convert gasoline into motion so that your car can move. Currently the easiest way to create motion from gasoline is to burn the gasoline inside an engine. Therefore, a car engine is an internal combustion engine — combustion takes place internally. There are different kinds of internal combustion engines. Diesel engines are one type and gas turbine engines are another. Each has its own advantages and disadvantages. There is also the external combustion engine. The steam engine in old-fashioned trains and steamboats is the best example of an external combustion engine. The fuel (coal, wood, oil) in a steam engine burns outside the engine to create steam, and the steam creates motion inside the engine. Internal combustion is a lot more efficient than external combustion, plus an internal combustion engine is a lot smaller. The principle behind any reciprocating internal combustion engine: If you put a tiny amount of high-energy-density fuel (like gasoline) in a small, enclosed space and ignite it, an incredible amount of energy is released in the form of expanding gas. You can use that energy for interesting purposes. For example, if you can create a cycle that allows you to set off explosions like this hundreds of times per minute, and if you can harness that energy in a useful way, what you have is the core of a car engine. Almost every car with a gasoline engine uses a four-stroke combustion cycle to convert gasoline into motion. The four-stroke approach is also known as the Otto cycle, in honor of Nikolaus Otto, who invented it in 1867. The four strokes are illustrated in Figure 1. They are: Intake stroke Compression stroke Combustion stroke Exhaust stroke The piston is connected to the crankshaft by a connecting rod. As the crankshaft revolves, it has the effect of "resetting the cannon." Here's what happens as the engine goes through its cycle: The piston starts at the top, the intake valve opens, and the piston moves down to let the engine take in a cylinder full of air and gasoline. This is the intake stroke. Only the tiniest drop of gasoline needs to be mixed into the air for this to work. (Part 1 of the figure) Then the piston moves back up to compress this fuel/air mixture. Compression makes the explosion more powerful. (Part 2 of the figure) When the piston reaches the top of its stroke, the spark plug emits a spark to ignite the gasoline. The gasoline charge in the cylinder explodes, driving the piston down. (Part 3 of the figure) Once the piston hits the bottom of its stroke, the exhaust valve opens and the exhaust leaves the cylinder to go out the tailpipe. (Part 4 of the figure) Now the engine is ready for the next cycle, so it intakes another charge of air and gas. In an engine, the linear motion of the pistons is converted into rotational motion by the crankshaft. The rotational motion is nice because we plan to turn (rotate) the car's wheels with it anyway. The core of the engine is the cylinder, with the piston moving up and down inside the cylinder. Single cylinder engines are typical of most lawn mowers, but usually cars have more than one cylinder (four, six and eight cylinders are common). In a multi-cylinder engine, the cylinders usually are arranged in one of three ways: inline, V or flat (also known as horizontally opposed or boxer), as shown in the figures to the left. The spark plug supplies the spark that ignites the air/fuel mixture so that combustion can occur. The spark must happen at just the right moment for things to work properly. The intake and exhaust valves open at the proper time to let in air and fuel and to let out exhaust. Note that both valves are closed during compression and combustion so that the combustion chamber is sealed. Piston rings provide a sliding seal between the outer edge of the piston and the inner edge of the cylinder. The rings serve two purposes: They prevent the fuel/air mixture and exhaust in the combustion chamber from leaking into the sump during compression and combustion. They keep oil in the sump from leaking into the combustion area, where it would be burned and lost. Most cars that "burn oil" and have to have a quart added every 1,000 miles are burning it because the engine is old and the rings no longer seal things properly. Many modern vehicles use more advance materials for piston rings. That's one of the reasons why engines last longer and can go longer between oil changes. The sump surrounds the crankshaft. It contains some amount of oil, which collects in the bottom of the sump (the oil pan). So you go out one morning and your engine will turn over but it won't start. What could be wrong? Now that you know how an engine works, you can understand the basic things that can keep an engine from running. Three fundamental things can happen: a bad fuel mix, lack of compression or lack of spark. Beyond that, thousands of minor things can create problems, but these are the "big three." Based on the simple engine we have been discussing, here is a quick rundown on how these problems affect your engine: A bad fuel mix can occur in several ways: You are out of gas, so the engine is getting air but no fuel. - The air intake might be clogged, so there is fuel but not enough air. - The fuel system might be supplying too much or too little fuel to the mix, meaning that combustion does not occur properly. - There might be an impurity in the fuel (like water in your gas tank) that prevents the fuel from burning. Lack of compression: If the charge of air and fuel cannot be compressed properly, the combustion process will not work like it should. Lack of compression might occur for these reasons: - Your piston rings are worn (allowing the air/fuel mix to leak past the piston during compression). - The intake or exhaust valves are not sealing properly, again allowing a leak during compression. - There is a hole in the cylinder. The most common "hole" in a cylinder occurs where the top of the cylinder (holding the valves and spark plug and also known as the cylinder head) attaches to the cylinder itself. Generally, the cylinder and the cylinder head bolt together with a thin gasket pressed between them to ensure a good seal. If the gasket breaks down, small holes develop between the cylinder and the cylinder head, and these holes cause leaks. Lack of spark: The spark might be nonexistent or weak for several reasons: - If your spark plug or the wire leading to it is worn out, the spark will be weak. - If the wire is cut or missing, or if the system that sends a spark down the wire is not working properly, there will be no spark. - If the spark occurs either too early or too late in the cycle (i.e. if the ignition timing is off), the fuel will not ignite at the right time. If the battery is dead, you cannot turn over the engine to start it. If the bearings that allow the crankshaft to turn freely are worn out, the crankshaft cannot turn so the engine cannot run. If the valves do not open and close at the right time or at all, air cannot get in and exhaust cannot get out, so the engine cannot run. If you run out of oil, the piston cannot move up and down freely in the cylinder, and the engine will seize. The valve train consists of the valves and a mechanism that opens and closes them. The opening and closing system is called a camshaft. The camshaft has lobes on it that move the valves up and down. Most modern engines have what are called overhead cams. This means that the camshaft is located above the valves, as shown in Figure 5. The cams on the shaft activate the valves directly or through a very short linkage. Older engines used a camshaft located in the sump near the crankshaft. A timing belt or timing chain links the crankshaft to the camshaft so that the valves are in sync with the pistons. The camshaft is geared to turn at one-half the rate of the crankshaft. Many high-performance engines have four valves per cylinder (two for intake, two for exhaust), and this arrangement requires two camshafts per bank of cylinders, hence the phrase "dual overhead cams." The ignition system (Figure 6) produces a high-voltage electrical charge and transmits it to the spark plugs via ignition wires. The charge first flows to a distributor, which you can easily find under the hood of most cars. The distributor has one wire going in the center and four, six or eight wires (depending on the number of cylinders) coming out of it. These ignition wires send the charge to each spark plug. The engine is timed so that only one cylinder receives a spark from the distributor at a time. This approach provides maximum smoothness. The cooling system in most cars consists of the radiator and water pump. Water circulates through passages around the cylinders and then travels through the radiator to cool it off. In a few cars (most notably pre-1999 Volkswagen Beetles), as well as most motorcycles and lawn mowers, the engine is air-cooled instead (You can tell an air-cooled engine by the fins adorning the outside of each cylinder to help dissipate heat.). Air-cooling makes the engine lighter but hotter, generally decreasing engine life and overall performance. So now you know how and why your engine stays cool. But why is air circulation so important? Most cars are normally aspirated, which means that air flows through an air filter and directly into the cylinders. High-performance and modern fuel-efficient engines are either turbocharged or supercharged, which means that air coming into the engine is first pressurized (so that more air/fuel mixture can be squeezed into each cylinder) to increase performance. The amount of pressurization is called boost. A turbocharger uses a small turbine attached to the exhaust pipe to spin a compressing turbine in the incoming air stream. A supercharger is attached directly to the engine to spin the compressor. Since the turbocharger is reusing hot exhaust to spin the turbine and compress the air, it increases the power from smaller engines. So a fuel-sipping four-cylinder can see horsepower that you might expect a six-cylinder engine to put out while getting 10 to 30 percent better fuel economy. Increasing your engine's performance is great, but what exactly happens when you turn the key to start it? The starting system consists of an electric starter motor and a starter solenoid. When you turn the ignition key, the starter motor spins the engine a few revolutions so that the combustion process can start. It takes a powerful motor to spin a cold engine. The starter motor must overcome: - All of the internal friction caused by the piston rings - The compression pressure of any cylinder(s) that happens to be in the compression stroke - The energy needed to open and close valves with the camshaft - All of the other things directly attached to the engine, like the water pump, oil pump, alternator, etc. Because so much energy is needed and because a car uses a 12-volt electrical system, hundreds of amps of electricity must flow into the starter motor. The starter solenoid is essentially a large electronic switch that can handle that much current. When you turn the ignition key, it activates the solenoid to power the motor. When it comes to day-to-day car maintenance, your first concern is probably the amount of gas in your car. How does the gas that you put in power the cylinders? The engine's fuel system pumps gas from the gas tank and mixes it with air so that the proper air/fuel mixture can flow into the cylinders. Fuel is delivered in modern vehicles in two common ways: port fuel injection and direct fuel injection. In a fuel-injected engine, the right amount of fuel is injected individually into each cylinder either right above the intake valve (port fuel injection) or directly into the cylinder (direct fuel injection). Older vehicles were carbureted, where gas and air were mixed by a carburetor as the air flowed into the engine. Oil also plays an important part. The lubrication system makes sure that every moving part in the engine gets oil so that it can move easily. The two main parts needing oil are the pistons (so they can slide easily in their cylinders) and any bearings that allow things like the crankshaft and camshafts to rotate freely. In most cars, oil is sucked out of the oil pan by the oil pump, run through the oil filter to remove any grit, and then squirted under high pressure onto bearings and the cylinder walls. The oil then trickles down into the sump, where it is collected again and the cycle repeats. Now that you know about some of the stuff that you put in your car, let's look at some of the stuff that comes out of it. The exhaust system includes the exhaust pipe and the muffler. Without a muffler, what you would hear is the sound of thousands of small explosions coming out your tailpipe. A muffler dampens the sound. The emission control system in modern cars consists of a catalytic converter, a collection of sensors and actuators, and a computer to monitor and adjust everything. For example, the catalytic converter uses a catalyst and oxygen to burn off any unused fuel and certain other chemicals in the exhaust. An oxygen sensor in the exhaust stream makes sure there is enough oxygen available for the catalyst to work and adjusts things if necessary. Besides gas, what else powers your car? The electrical system consists of a battery and an alternator. The alternator is connected to the engine by a belt and generates electricity to recharge the battery. The battery makes 12-volt power available to everything in the car needing electricity (the ignition system, radio, headlights, windshield wipers, power windows and seats, computers, etc.) through the vehicle's wiring. Increase displacement: More displacement means more power because you can burn more gas during each revolution of the engine. You can increase displacement by making the cylinders bigger or by adding more cylinders. Twelve cylinders seems to be the practical limit. Increase the compression ratio: Higher compression ratios produce more power, up to a point. The more you compress the air/fuel mixture, however, the more likely it is to spontaneously burst into flame (before the spark plug ignites it). Higher-octane gasolines prevent this sort of early combustion. That is why high-performance cars generally need high-octane gasoline — their engines are using higher compression ratios to get more power. Stuff more into each cylinder: If you can cram more air (and therefore fuel) into a cylinder of a given size, you can get more power from the cylinder (in the same way that you would by increasing the size of the cylinder) without increasing the fuel required for combustion. Turbochargers and superchargers pressurize the incoming air to effectively cram more air into a cylinder. Cool the incoming air: Compressing air raises its temperature. However, you would like to have the coolest air possible in the cylinder because the hotter the air is, the less it will expand when combustion takes place. Therefore, many turbocharged and supercharged cars have an intercooler. An intercooler is a special radiator through which the compressed air passes to cool it off before it enters the cylinder. Let air come in more easily: As a piston moves down in the intake stroke, air resistance can rob power from the engine. Air resistance can be lessened dramatically by putting two intake valves in each cylinder. Some newer cars are also using polished intake manifolds to eliminate air resistance there. Bigger air filters can also improve air flow. Let exhaust exit more easily: If air resistance makes it hard for exhaust to exit a cylinder, it robs the engine of power. Air resistance can be lessened by adding a second exhaust valve to each cylinder. A car with two intake and two exhaust valves has four valves per cylinder, which improves performance. When you hear a car ad tell you the car has four cylinders and 16 valves, what the ad is saying is that the engine has four valves per cylinder. If the exhaust pipe is too small or the muffler has a lot of air resistance, this can cause back-pressure, which has the same effect. High-performance exhaust systems use headers, big tail pipes and free-flowing mufflers to eliminate back-pressure in the exhaust system. When you hear that a car has "dual exhaust," the goal is to improve the flow of exhaust by having two exhaust pipes instead of one. Make everything lighter: Lightweight parts help the engine perform better. Each time a piston changes direction, it uses up energy to stop the travel in one direction and start it in another. The lighter the piston, the less energy it takes. This results in better fuel efficiency as well as better performance. Inject the fuel: Fuel injection allows very precise metering of fuel to each cylinder. This improves performance and fuel economy.

open differential vs limited slip

The vast majority of rear-wheel drive cars have an open differential. This means that the rear wheels can spin independently of each other. ... If the other wheel spins in the opposite direction, you have an open differential. If it spins in the same direction, you have a limited slip differential, or LSD. Tesla uses open differential for traction control. They have a PCB that monitors traction and adjusts as needed.

Why have eight cylinders in an engine? Why not have one big cylinder of the same displacement of the eight cylinders instead?

There are a couple of reasons why a big 4.0-liter engine has eight half-liter cylinders rather than one big 4-liter cylinder. The main reason is smoothness. A V-8 engine is much smoother because it has eight evenly spaced explosions instead of one big explosion. Another reason is starting torque. When you start a V-8 engine, you are only driving two cylinders (1 liter) through their compression strokes, but with one big cylinder you would have to compress 4 liters instead.

planetary gear uses

This type of gearing is sometimes used in tractors and construction equipment to provide high torque to the drive wheels. In bicycle hub gears, the sun is usually stationary, being keyed to the axle or even machined directly onto it. The planetary gear carrier is used as input. Used in automatic transmissions

Climate change / Global warming

Weather is local and short-term. If it snows in the town where you live next Tuesday, that's weather. Climate is long-term and doesn't relate to one small location. The climate of an area is the average weather conditions in a region over a long period of time. If the part of the world you live in has cold winters with lots of snow, that would be part of the climate for the region you live in. The winters there have been cold and snowy for as long as weather has been recorded, so we know generally what to expect. It's important to understand that when we talk about climate being long-term, we mean really long-term. Even a few hundred years is pretty short-term when it comes to climate. In fact, changes in climate sometimes take tens of thousands of years. That means if you happen to have a winter that isn't as cold as usual, with not very much snow -- or even two or three such winters in a row -- that isn't a change in climate. That's just an anomaly -- an event that falls outside of the usual statistical range but doesn't represent any permanent, long-term change. It's also important to understand that even small changes in climate can have major effects. When scientists talk about "the Ice Age," you probably envision the world frozen, covered with snow and suffering from frigid temperatures. In fact, during the last ice age (ice ages recur roughly every 50,000 to 100,000 years), the earth's average temperature was only 5 Celsius degrees cooler than modern temperature averages [Source: NASA]. Global warming is a significant increase in the Earth's climatic temperature over a relatively short period of time as a result of the activities of humans. The Intergovernmental Panel on Climate Change (IPCC), a group of over 2,500 scientists from countries across the world, convened in Paris in February, 2007 to compare and advance climate research. The scientists determined that the Earth has warmed .6 degrees Celsius between 1901 and 2000. When the timeframe is advanced by five years, from 1906 to 2006, the scientists found that the temperature increase was .74 degrees Celsius. Of the last 12 years, 11 have ranked among the warmest years since 1850. The ocean's temperature has increased at least to depths of 3,000 meters (over 9,800 feet); the ocean absorbs more than 80 percent of all heat added to the climate system. Average Arctic temperatures increased by nearly twice the global average rate over the last 100 years (the IPCC also noted that Arctic temperatures have are highly variable from decade to decade). The greenhouse effect is a little more complicated than your hot car. When the sun's rays hit the Earth's atmosphere and the surface of the Earth, approximately 70 percent of the energy stays on the planet, absorbed by land, oceans, plants and other things. The other 30 percent is reflected into space by clouds, snow fields and other reflective surfaces [Source: NASA]. But even the 70 percent that gets through doesn't stay on earth forever (otherwise the Earth would become a blazing fireball). The Earth's oceans and land masses eventually radiate heat back out. Some of this heat makes it into space. The rest of it ends up getting absorbed when it hits certain things in the atmosphere, such as carbon dioxide, methane gas and water vapor. After these components in our atmosphere absorb all this heat, they emit energy (also in the form of heat). The heat that doesn't make it out through Earth's atmosphere keeps the planet warmer than it is in outer space, because more energy is coming in through the atmosphere than is going out. This is all part of the greenhouse effect that keeps the Earth warm. Carbon dioxide (CO2) is a colorless gas that is a byproduct of the combustion of organic matter. It makes up less than 0.04 percent of Earth's atmosphere, most of which was put there by volcanic activity very early in the planet's life. Today, human activities are pumping huge amounts of CO2 into the atmosphere, resulting in an overall increase in carbon dioxide concentrations [Source: Keeling, C.D. and T.P. Whorf]. These increased concentrations are considered the primary factor in global warming, because carbon dioxide absorbs infrared radiation. Most of the energy that escapes Earth's atmosphere comes in this form, so extra CO2 means more energy absorption and an overall increase in the planet's temperature. The Worldwatch Institute reports that carbon emissions worldwide have increased from about 1 billion tons in 1900 to about 7 billion tons in 1995. The Institute also notes that the average surface temperature of Earth has gone from 14.5 degrees C in 1860 to 15.3 degrees C in 1980. The Earth's main ice-covered landmass is Antarctica at the South Pole, with about 90 percent of the world's ice (and 70 percent of its fresh water). Antarctica is covered with ice an average of 2,133 meters (7,000 feet) thick. If all of the Antarctic ice melted, sea levels around the world would rise about 61 meters (200 feet). But the average temperature in Antarctica is -37°C, so the ice there is in no danger of melting. In fact, in most parts of the continent it never gets above freezing. At the other end of the world, the North Pole, the ice is not nearly as thick as at the South Pole. The ice floats on the Arctic Ocean. If it melted, sea levels would not be affected. There is a significant amount of ice covering Greenland, which would add another 7 meters (20 feet) to the oceans if it melted. Because Greenland is closer to the equator than Antarctica, the temperatures there are higher, so the ice is more likely to melt. Scientists from the Universities of London and Edinburgh say that ice loss in Antarctica and Greenland together contribute approximately 12 percent of the rise in sea levels [Source: Science Daily]. The most devastating effects, and also the hardest to predict, are the effects on the world's living ecosystems. Many ecosystems are very delicate, and the slightest change can kill off several species as well as any other species that depend on them. Most ecosystems are interconnected, so the chain reaction of effects could be immeasurable. The results could be something like a forest gradually dying off and turning to grassland or entire coral reefs dying. Many species of plants and animals would adapt or move to deal with the shift in climate, but many would become extinct. The human cost of global warming is hard to quantify. Thousands of lives per year could be lost as the elderly or ill suffer from heat stroke and other heat-related trauma. Poor and underdeveloped nations would suffer the worst effects, since they would not have the financial resources to deal with the problems that come with an increase in temperature. Huge numbers of people could die from starvation if a decrease in precipitation limits crop growth and from disease if coastal flooding leads to widespread water-borne illness. The Carnegie Institution estimates that around $5 billion in crop losses per year are due to global warming. Farmers see a decrease of about 40 million metric tons of cereal grains like wheat, barley and corn each year. Scientists discovered that an increase of 1 degree Fahrenheit in average temperature results in a 3 to 5 percent drop in crop yields [Source: Science Daily].

Throttle plate on carburetor

When you pull the trigger you open the throttle plate allowing more air to enter. When the engine is idling, the throttle plate is nearly closed (the position of the throttle plate in the photos is the idle position). There is not really enough air flowing through the venturi to create a vacuum. However, on the back side of the throttle plate there is a lot of vacuum (because the throttle plate is restricting the airflow). If a tiny hole is drilled into the side of the carb's tube, fuel can be drawn into the tube by the throttle vacuum. This tiny hole is called the idle jet. The other screw of the pair seen in photo 1 is labeled "Lo" and controls the amount of fuel that flows through the idle jet.

Dual-clutch transmission

When compared to manual transmissions and traditional automatics, dual-clutch automatics are quicker to shift. The powertrain never has to be disconnected from the transmission, which allows for lightning-quick gear changes. The result is improved acceleration compared to a traditional manual or a regular automatic. But there's also something in between that offers the best of both worlds -- the dual-clutch transmission, also called the semi-automatic transmission, the "clutchless" manual transmission and the automated manual transmission. In the world of racecars, semi-automatic transmissions, such as the sequential manual gearbox (or SMG), have been a staple for years. A dual-clutch transmission offers the function of two manual gearboxes in one. To understand what this means, it's helpful to review how a conventional manual gearbox works. When a driver wants to change from one gear to another in a standard stick-shift car, he first presses down the clutch pedal. This operates a single clutch, which disconnects the engine from the gearbox and interrupts power flow to the transmission. Then the driver uses the stick shift to select a new gear, a process that involves moving a toothed collar from one gear wheel to another gear wheel of a different size. Devices called synchronizers match the gears before they are engaged to prevent grinding. Once the new gear is engaged, the driver releases the clutch pedal, which re-connects the engine to the gearbox and transmits power to the wheels. So, in a conventional manual transmission, there is not a continuous flow of power from the engine to the wheels. Instead, power delivery changes from on to off to on during gearshift, causing a phenomenon known as "shift shock" or "torque interrupt." For an unskilled driver, this can result in passengers being thrown forward and back again as gears are changed. A dual-clutch gearbox, by contrast, uses two clutches, but has no clutch pedal. Sophisticated electronics and hydraulics control the clutches, just as they do in a standard automatic transmission. In a DCT, however, the clutches operate independently. One clutch controls the odd gears (first, third, fifth and reverse), while the other controls the even gears (second, fourth and sixth). Using this arrangement, gears can be changed without interrupting the power flow from the engine to the transmission. Because a dual-clutch transmission is similar to an automatic, you might think that it requires a torque converter, which is how an automatic transfers engine torque from the engine to the transmission. DCTs, however, don't require torque converters. Instead, DCTs currently on the market use wet multi-plate clutches. A "wet" clutch is one that bathes the clutch components in lubricating fluid to reduce friction and limit the production of heat. Several manufacturers are developing DCTs that use dry clutches, like those usually associated with manual transmissions, but all production vehicles equipped with DCTs today use the wet version. Many motorcycles have single multi-plate clutches. Like torque converters, wet multi-plate clutches use hydraulic pressure to drive the gears. The fluid does its work inside the clutch piston, seen in the diagram above. When the clutch is engaged, hydraulic pressure inside the piston forces a set of coil springs part, which pushes a series of stacked clutch plates and friction discs against a fixed pressure plate. The friction discs have internal teeth that are sized and shaped to mesh with splines on the clutch drum. In turn, the drum is connected to the gearset that will receive the transfer force. Audi's dual-clutch transmission has both a small coil spring and a large diaphragm spring in its wet multi-plate clutches. To disengage the clutch, fluid pressure inside the piston is reduced. This allows the piston springs to relax, which eases pressure on the clutch pack and pressure plate. Hopefully it's becoming clear why the DCT is classified as an automated manual transmission. In principle, the DCT behaves just like a standard manual transmission: It's got input and auxiliary shafts to house gears, synchronizers and a clutch. What it doesn't have is a clutch pedal, because computers, solenoids and hydraulics do the actual shifting. Even without a clutch pedal, the driver can still "tell" the computer when to take action through paddles, buttons or a gearshift. Perhaps the most compelling advantage of a DCT is improved fuel economy. Because power flow from the engine to the transmission is not interrupted, fuel efficiency increases dramatically. Some experts say that a six-speed DCT can deliver up to a 10 percent increase in relative fuel efficiency when compared to a conventional five-speed automatic. Many car manufacturers are interested in DCT technology. However, some automakers are wary of the additional costs associated with modifying production lines to accommodate a new type of transmission. This could initially drive up the costs of cars outfitted with DCTs, which might discourage cost-conscious consumers.

carnation

a double-flowered cultivated variety of clove pink, with gray-green leaves and showy pink, white, or red flowers.

cannabinoid

any of a group of closely related compounds which include cannabinol and the active constituents of cannabis. A cannabinoid is one of a class of diverse chemical compounds that acts on cannabinoid receptors, which are part of the endocannabinoid system found in cells that alter neurotransmitter release in the brain. Ligands for these receptor proteins include the endocannabinoids produced naturally in the body by animals; phytocannabinoids, found in cannabis; and synthetic cannabinoids, manufactured artificially. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC), the primary psychoactive compound in cannabis. Cannabidiol (CBD) is another major constituent of the plant. There are at least 113 different cannabinoids isolated from cannabis, exhibiting varied effects. Synthetic cannabinoids encompass a variety of distinct chemical classes: the classical cannabinoids structurally related to THC, the nonclassical cannabinoids (cannabimimetics) including the aminoalkylindoles, 1,5-diarylpyrazoles, quinolines, and arylsulfonamides as well as eicosanoids related to endocannabinoids.

wallaby

any of various small or medium-sized kangaroos; often brightly colored

slag

the scum formed by oxidation at the surface of molten metals

undercut

(v.) to undermine something or detract from its force (v.) to charge less for something than somebody else

"People who live in glass houses shouldn't throw stones."

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Where is the camshaft in a 2 stroke engine?

Fool. There is no camshaft in a two stroke engine.

where is centripetal force used

For example, If you whirl a ball on a string above your head, the centripetal force is the force of tension. If you're in a spacecraft orbiting the earth, the centripetal force is the force of gravity. If you drive a car in a circle, the centripetal force is the force of friction between the road and the tires.

superchargers vs turbos

If you know how a jet engine works, you're halfway to understanding a car's turbocharger. A jet engine sucks in cold air at the front, squeezes it into a chamber where it burns with fuel, and then blasts hot air out of the back. As the hot air leaves, it roars past a turbine (a bit like a very compact metal windmill) that drives the compressor (air pump) at the front of the engine. This is the bit that pushes the air into the engine to make the fuel burn properly. The turbocharger on a car applies a very similar principle to a piston engine. It uses the exhaust gas to drive a turbine. This spins an air compressor that pushes extra air (and oxygen) into the cylinders, allowing them to burn more fuel each second. However, in practice, an engine fitted with a turbocharger is much smaller and lighter than an engine producing the same power without a turbocharger, so a turbocharger car can give better fuel economy in that respect. Manufacturers can often now get away with fitting a much smaller engine to the same car (such as a turbocharged V6 instead of a V8, or a turbocharged four-cylinder engine instead of a V6). Turbochargers give a car more power, but that extra power is not coming directly from the waste exhaust gas—and that sometimes confuses people. With a turbocharger, we harness some of the energy in the exhaust to drive the compressor, which allows the engine to burn more fuel each second. This extra fuel is where the car's extra power comes from. All the exhaust gas is doing is powering the turbocharger and, because the turbocharger isn't connected to the car's crankshaft or wheels, it's not directly adding to the car's driving power in any way. It's simply enabling the same engine to burn fuel at a faster rate, so making it more powerful. That's why a turbocharged car can produce more power (which is another way of saying "more energy per second"). A supercharger (or "mechanically driven supercharger" to give it its full name) is very similar to a turbocharger, but instead of being driven by exhaust gases using a turbine, it's powered from the car's spinning crankshaft. That's usually a disadvantage: where a turbocharger is powered by waste energy in the exhaust, a supercharger actually steals energy from the car's own power source (the crankshaft), which is generally unhelpful. One way to improve an engine is to use a turbocharger—a pair of fans that harness waste exhaust power from the back of an engine to cram more air into the front, delivering more "oomph" than you'd otherwise get. Keeping the air that enters the engine cool is an important part of the design of both superchargers and turbochargers. Compressing air increases its temperature, so it is common to use a small radiator called an intercooler between the pump and the engine to reduce the temperature of the air. There are three main categories of superchargers for automotive use: - Centrifugal turbochargers - driven from exhaust gases. - Centrifugal superchargers - driven directly by the engine via a belt-drive. - Positive displacement pumps - such as the Roots, twin-screw (Lysholm), and TVS (Eaton) blowers. Roots blowers tend to be only 40-50% efficient at high boost levels; by contrast centrifugal (dynamic) superchargers are 70-85% efficient at high boost. Lysholm-style blowers can be nearly as efficient as their centrifugal counterparts over a narrow range of load/speed/boost, for which the system must be specifically designed. Mechanically driven superchargers may absorb as much as a third of the total crankshaft power of the engine and are less efficient than turbochargers. However, in applications for which engine response and power are more important than other considerations, such as top-fuel dragsters and vehicles used in tractor pulling competitions, mechanically driven superchargers are very common. The thermal efficiency, or fraction of the fuel/air energy that is converted to output power, is less with a mechanically driven supercharger than with a turbocharger, because turbochargers use energy from the exhaust gas that would normally be wasted. For this reason, both economy and the power of a turbocharged engine are usually better than with superchargers. Turbochargers suffer (to a greater or lesser extent) from so-called turbo-spool (turbo lag; more correctly, boost lag), in which initial acceleration from low RPM is limited by the lack of sufficient exhaust gas mass flow (pressure). Once engine RPM is sufficient to raise the turbine RPM into its designed operating range, there is a rapid increase in power, as higher turbo boost causes more exhaust gas production, which spins the turbo yet faster, leading to a belated "surge" of acceleration. This makes the maintenance of smoothly increasing RPM far harder with turbochargers than with engine-driven superchargers, which apply boost in direct proportion to the engine RPM. The main advantage of an engine with a mechanically driven supercharger is better throttle response, as well as the ability to reach full-boost pressure instantaneously. With the latest turbocharging technology and direct gasoline injection, throttle response on turbocharged cars is nearly as good as with mechanically powered superchargers, but the existing lag time is still considered a major drawback, especially considering that the vast majority of mechanically driven superchargers are now driven off clutched pulleys, much like an air compressor. Turbocharging has been more popular than superchargers among auto manufacturers owing to better power and efficiency.

how many people on food stamps?

Participants. A summary statistical report indicated that an average of 44.2 million people used the program in FY 2016, down from 45.8 million in 2015 and below the 2013 peak of 47.6 million. SNAP is able to support 75% of those eligible for the program.

for-profit

A business organization whose goal is to make a profit for the owners denoting an organization that operates to make a profit, especially one (such as a hospital or school) that would more typically be nonprofit.

cerebrotonia

A mental over-intensity that promotes apprehensiveness and social inhibition tense, introverted, socially restrained, inhibited personality

Scientists Discover Method to Turn CO2 Into Methane

A new catalyst can turn carbon dioxide or carbon monoxide into methane. The catalyst the researchers discovered is similar to the chlorophyll in a plant, only instead of turning CO2 into oxygen it turns it into methane. The molecule uses energy from the sun to break up the CO2 molecule into carbon and oxygen atoms, which then combine with hydrogen to form methane and water. The team was initially trying to turn CO2 into carbon monoxide, which is easier and more commonly done. They succeeded, but noticed their catalyst was also producing methane. After a series of experiments they realized that not only could their catalyst turn CO2 into carbon monoxide, it could then turn that carbon monoxide into methane.

postnuptial financial agreement

A postnuptial agreement is a contract created by spouses after entering into marriage that outlines the ownership of financial assets in the event of a divorce. ... A postnuptial agreement is also known as a "post-marital agreement" or "postnup.

reciprocating mass

A reciprocating mass is a weighted object that spins or moves. In an engine, that would be the crankshaft, connecting rods, pistons, camchain or belt, camshaft(s), valvetrain, and flywheel. Every single one of those parts move as the engine runs Want to have 2 pistons go in opposite directions to cancel out each others forces

Supercharger

A supercharger is an air compressor that increases the pressure or density of air supplied to an internal combustion engine. This gives each intake cycle of the engine more oxygen, letting it burn more fuel and do more work, thus increasing power. Power for the supercharger can be provided mechanically by means of a belt, gear, shaft, or chain connected to the engine's crankshaft. Common usage restricts the term supercharger to mechanically driven units; when power is instead provided by a turbine powered by exhaust gas, a supercharger is known as a turbocharger or just a turbo - or in the past a turbosupercharger. There are two main types of superchargers defined according to the method of gas transfer: positive displacement and dynamic compressors. Positive displacement blowers and compressors deliver an almost constant level of pressure increase at all engine speeds (RPM). Dynamic compressors do not deliver pressure at low speeds; above a threshold speed pressure increases exponentially.[8]

worm gear

A type of gear that is a single tooth wrapped around a cylinder like a screw. gear consisting of a shaft with screw thread (the worm) that meshes with a toothed wheel (the worm wheel) used in car differentials Worm gears are used when large gear reductions are needed. It is common for worm gears to have reductions of 20:1, and even up to 300:1 or greater.

superbugs

Superbugs are germs that have become resistant to the drugs that should destroy them. These drug resistant bacteria and fungi are difficult to control and treat. Often, superbugs are bacteria that have become resistant to antibiotics. They can also be fungi. When bacteria grow and spread, they can develop mutations in their DNA that make them resistant to certain types of drugs. When antibiotics are used to treat an infection, bacteria without the resistance mechanism die, while those that have the resistance mechanism may continue to live and multiply.

deleveraging

The inverse of "leveraging," whereby businesses increase their financial power by borrowing money (debt) in addition to their own assets (equity). In times of uncertainty or credit tightening, the same businesses seek to improve their debt-to-equity ratios by shedding debt through the sale of assets purchased with borrowed money. A time period when credit use shrinks in an economy instead of expanding as during normal economic times

snell's law

The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, for a given frequency. Snell's law is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air.

vitalism

Vitalism is the belief that "living organisms are fundamentally different from non-living entities because they contain some non-physical element or are governed by different principles than are inanimate things"

central vacuum

With a central vacuum system, you place inlets around your home at convenient locations. Instead of plugging a portable vacuum into pre-determined electrical outlets and hoping the cord reaches around your home, you can move the central vacuum hose from inlet to inlet. Where you put the inlets is up to you. You can even install an automatic dustpan that lets you quickly sweep debris into a wall vent using a regular broom.

The Carburetor

a device that blends air and fuel for most older cars (pre-1990) and small engines. As air moves quickly through the _____, it creates a vacuum, which draws more and more fuel into the mixture The carburetor on a chain saw is pretty simple, as carbs go, but it's not entirely uncomplicated. The job of the carb is to accurately meter extremely tiny quantities of fuel and mix it with the air entering the engine so that the engine runs properly. If there is not enough fuel mixed with the air, the engine "runs lean" and either will not run or potentially gets damaged (in a two-stroke engine, the fuel also supplies the engine's lubricant). If there is too much fuel mixed with the air, the engine "runs rich" and either will not run (it floods), runs with a lot of smoke, runs poorly (bogs down, stalls easily) or, at the very least, wastes fuel. The carb is in charge of getting the mixture just right. Here are the parts of a carb: - A carburetor is essentially a tube. - There is an adjustable plate across the tube called the throttle plate, which controls how much air can flow through the tube. You can see this circular brass plate in photo 1 above. - At some point in the tube there is a narrowing, called the venturi, and in this narrowing a vacuum is created. - - In this narrowing there is a hole, called a jet, that lets the vacuum draw in fuel. You can see the jet on the left side of the venturi in photo 2.

port fuel injection

a fuel injection system that uses one injector at each cylinder, making fuel distribution exactly equal among all the cylinders.

secularist

a person who advocates separation of the state from religious institutions someone who believes religion and society should be separate an advocate of secularism; someone who believes that religion should be excluded from government and education

Gestalt psychology

a psychological approach that emphasizes that we often perceive the whole rather than the sum of the parts Gestalt psychology is a school of thought that looks at the human mind and behavior as a whole. When trying to make sense of the world around us, Gestalt psychology suggests that we do not simply focus on every small component

mesomorphy

a tendency toward muscularity pertaining to or having a muscular or sturdy body build characterized by the relative prominence of structures developed from the embryonic mesoderm (contrasted with ectomorphic, endomorphic).

endomorphy

a tendency toward obesity round, fat, and heavy Endomorphs are said to have a higher percentage of body fat with less muscle mass. They're often heavier and rounder, but not necessarily obese. Because of their physical makeup, people with endomorphic bodies are more sensitive to calorie consumption than people with other body types.

Otto Cycle

a thermodynamic cycle, consisting of a pair of adiabatic processes and a pair of isochoric processes, that converts heat into work, e.g., the four-stroke engine cycle of intake, compression, ignition, and exhaust The Otto cycle is a description of what happens to a mass of gas as it is subjected to changes of pressure, temperature, volume, addition of heat, and removal of heat. The mass of gas that is subjected to those changes is called the system. The system, in this case, is defined to be the fluid (gas) within the cylinder.

deflagration

a very rapid oxidation reaction accompanied by the generation of a low-intensity pressure wave that can disrupt the surroundings Deflagration is subsonic combustion propagating through heat transfer; hot burning material heats the next layer of cold material and ignites it. Most "fires" found in daily life, from flames to explosions such as that of black powder, are deflagrations. the action of heating a substance until it burns away rapidly.

deformation

alteration in the shape or dimensions of an object as a result of the application of stress to it change shape; alter from original state; morph

45 Percent of Surveyed American Adults Doubt Vaccine Safety

https://www.infectioncontroltoday.com/vaccines-vaccination/45-percent-surveyed-american-adults-doubt-vaccine-safety

interlinking

join or connect (two or more things) together. linked or locked closely together as by dovetailing

sought

looked for I have long sought an answer to the following question: If sought is the past tense of seek, how come you say "we played hide and seek all afternoon" instead of "we hid and sought all afternoon?" seek past tense

off-putting

makes you feel you do not want to go there again unpleasant, disconcerting, or repellent.

deep cryogen

near absolute zero substance

alongside

next to someone or something Use the adverb alongside when two things are right next to each other, like a boat and a dock or a hunter and her loyal dog.

third-rate

of very poor quality of inferior or very poor quality.

crackpot

one given to eccentric or lunatic notions an eccentric or foolish person A crackpot is a colorfully strange or odd person. You might describe your neighbor as a crackpot if he keeps farm animals inside his house and wears a clown costume everywhere he goes.

fermat's principle

or Principle of Least Time - a light ray follows the path between two points that requires a minimum amount of travel time Fermat's principle, also known as the principle of least time, is the link between ray optics and wave optics. In its original "strong" form, Fermat's principle states that the path taken by a ray between two given points is the path that can be traversed in the least time.

yogi

practitioner of yoga one who practices yoga and has achieved a high level of spiritual insight

primer bulb

primer bulb will typically need to be pressed to introduce gasoline into the carburetor.

raison d'etre

reason or justification for existing the most important reason or purpose for someone or something's existence.

postnuptial

relating to events after a marriage

bear in mind

remember, keep in mind or to keep in mind. phrase. If you tell someone to bear something in mind or to keep something in mind, you are reminding or warning them about something important which they should remember.

pigeon holed

stereotyped to decide that someone or something belongs to a particular type or group, especially without knowing much about them. There's a tendency to put handsome young actors into a pigeonhole.

ectomorphic

tall and thin characterized by a slender physical build developed from the outside layer of the embryo (adj) having a lean, slightly muscular body type

buffering capacity

the ability of a substance to resist changes in pH Surface waters and their fragile ecosystems are perhaps the most famous victims of acid rain. Most of the precipitation that enters a lake, river, stream or marsh must first pass over and seep through soil. All soil has a buffering capacity, or ability to resist changes in acidity and alkalinity. The soil's buffering capacity determines a water body's acidity. If the capacity is low, or has reached its limit, acid rain can pass through un-neutralized. Most life is comfortable at a near-neutral pH -- stray too far from pH 7.0, and delicate organisms begin to die. Plankton and invertebrates are sensitive to changes in acidity and die first. At pH 5.0, fish eggs degrade and young cannot develop. Adult fish and frogs can sometimes tolerate acidities as low as pH 4.0, but they starve as their weaker food sources die out. When acid rain disrupts the food chain, biodiversity decreases.

armchair psychology

the practice of answering questions about human behavior and mental processes through informal observation and speculation some dingus sitting behind a screen thinking they are a credible source on a topic they know nothing about armchair ____________ e.g. physicist, technician, etc.

devitalize

to make weak or lifeless sap of life or energy

nod

to move your head up and down

Yeast

unicellular fungi Yeasts are eukaryotic single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and 1,500 species are currently identified. They are estimated to constitute 1% of all described fungal species. Yeasts are unicellular organisms that evolved from multicellular ancestors, with some species having the ability to develop multicellular characteristics by forming strings of connected budding cells known as pseudohyphae or false hyphae. Yeast sizes vary greatly, depending on species and environment, typically measuring 3-4 µm in diameter, although some yeasts can grow to 40 µm in size. Most yeasts reproduce asexually by mitosis, and many do so by the asymmetric division process known as budding. Yeasts, with their single-celled growth habit, can be contrasted with molds, which grow hyphae. Fungal species that can take both forms (depending on temperature or other conditions) are called dimorphic fungi ("dimorphic" means "having two forms"). The yeast species Saccharomyces cerevisiae converts carbohydrates to carbon dioxide and alcohols a process known as fermentation. For thousands of years the carbon dioxide has been used in baking and the alcohol in alcoholic beverages. It is also a centrally important model organism in modern cell biology research, and is one of the most thoroughly researched eukaryotic microorganisms. Researchers have used it to gather information about the biology of the eukaryotic cell and ultimately human biology. Other species of yeasts, such as Candida albicans, are opportunistic pathogens and can cause infections in humans. Yeasts have recently been used to generate electricity in microbial fuel cells, and produce ethanol for the biofuel industry. Yeasts do not form a single taxonomic or phylogenetic grouping. The term "yeast" is often taken as a synonym for Saccharomyces cerevisiae, but the phylogenetic diversity of yeasts is shown by their placement in two separate phyla: the Ascomycota and the Basidiomycota. The budding yeasts ("true yeasts") are classified in the order Saccharomycetales, within the phylum Ascomycota.

on the face of it

used when you are describing how a situation seems on the surface without knowing all of the relevant facts; at first glance.

irreducibility

when you can't break something down any more; a fundamental element

in vitro

within a glass, observable within a test tube In vitro comes from the Latin term "in glass." The term refers to studies of biological properties that are done in a test tube (i.e. in a glass vessel) rather than in a human or animal. In vitro studies are often contrasted to in vivo ("in life") studies which are done inside an organism.

meaningless

without a purpose; lacking in importance; not important

idolatrously

worshiping idols. treating someone or something as an idol.

nicotinic acid

Niacin Niacin, also known as nicotinic acid, is an organic compound and a form of vitamin B3, an essential human nutrient. It has the formula C6H5NO2 and belongs to the group of the pyridinecarboxylic acid.

olga of kiev

Olga of Kiev, murdered over 5000 people in revenge for the murder of her husband, converted to Christianity and became a Saint. With a company of the Derevlian's best men now dead, Olga set her sights on the rest of their warriors in Dereva. So, this time she went to Dereva's capitol Iskorosten, with the official reason of holding a funeral for her late husband. The Derevlians threw a grand feast with much, much alcohol. Olga waited until the Derevlians were quite drunk, then ordered them all killed. Around 5,000 Derevlians were killed in the ensuing slaughter. She is known for her obliteration of the Drevlians, a tribe that had killed her husband Igor of Kiev. Even though it would be her grandson Vladimir that would convert the entire nation to Christianity, her efforts to spread Christianity through the Rus' earned Olga veneration as a saint. https://www.reddit.com/r/ProRevenge/comments/6pz8po/kill_my_husband_the_tale_of_princess_olga/

Other revelations about Musk are even more amazing. The new Elon Musk book reveals that Musk rents sumo wrestlers and castles for his parties. Also, he fears that Google is building a robot army that could accidentally wipe out humankind. The Musk biography also includes some fascinating quotes. He would rather commit "seppuku" (samurai ritual suicide) than fail. Also, after obtaining malaria during a 2000 trip, Musk learned that a vacation will "kill" people, according to SFIST.

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Santa Claus was the first form of surveillance.

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Four-cylinder engines commonly come in "straight" or "inline" configurations while 6-cylinder engines are usually configured in the more compact "V" shape, and thus are referred to as V6 engines. V6 engines were the engine of choice for American automakers because they're powerful and quiet, but turbocharging technologies have made four-cylinder engines more powerful and attractive to buyers. Historically, American auto consumers turned their noses up at four-cylinder engines, believing them to be slow, weak, unbalanced and short on acceleration. However, when Japanese auto makers, such as Honda and Toyota, began installing highly efficient four-cylinder engines in their cars in the 1980s and '90s, Americans found a new appreciation for the compact engine. Japanese models, such as the Toyota Camry, began quickly outselling comparable American models

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Batch file

A text file containing a series of OS commands. Autoexec.bat is a batch file. A batch file is a script file in DOS, OS/2 and Microsoft Windows. It consists of a series of commands to be executed by the command-line interpreter, stored in a plain text file.

what is a turbo on car?

A turbocharger, colloquially known as a turbo, is a turbine-driven forced induction device that increases an internal combustion engine's efficiency and power output by forcing extra compressed air into the combustion chamber. ... Twincharger refers to an engine with both a supercharger and a turbocharger.

how a touch screen works

A resistive touch screen consists of two thin flexible metallic layers separated by a small gap. These two layers contain an electric current running through them. When someone touches the top flexible layer of the screen, it pushes down and touches the bottom layer, thus interrupting the flow of current. There are many types of touch screens(Resistive, Capacitive,Acoustic, Optical Imaging, Infrared) but if you're talking about mobile phones there are basically two types of touch screens right now. Resistive Touch screen and Capacitive Touch screen. 1. Resistive Touch Screen: The resistive touch screen resists your touch literally and if you press harder you can feel the screen bent slightly. This is what makes the resistive touch work. There are two layers in the resistive touch, the resistive layer and the conducting layer. These are separated by tiny dots called spacers. The electric current flows through the conductive layer at all times but when you touch the screen i.e. resistive layer, it comes in contact with the conducting layer. Thus the electric current changes at that point and the function corresponding to that point is carried out. 2.Capacitive Touch Screen: Unlike Resistive touch Screen, it does not use the pressure of your finger for the flow of electricity. Instead, they work with anything that holds an electric charge, including human skin. They are made from materials like copper and indium tin oxide that hold electric charges in an electrostatic grid of wire each smaller than a human hair. There's a glass substance,a conductive layer , a protector, a controller and electrodes at the corners. The electrodes apply a low voltage to the conductive layer to form a electrostatic field. When a finger hits the screen, a tiny electrostatic charge is transferred to the field that completes the circuit. A voltage drop is created at that point. The location of the voltage drop is reported by the controller. And this is how a capacitive touchscreen works! Now a days , The mobile phones only come with capacitive touch screens.

Automatic transmission: has 2-3 planetary gear sets (depending on the transmission speeds. More gear sets = more speeds) and a torque converter. The main components of an automatic transmission include the torque converter, planetary gearset, pump, clutches, bands, sensors, valve body, and last but not least is the transmission fluid, otherwise known as ATF. Manual transmission: Uses normal gear pairs and clutch pad. Clutch and Clutch Pedal. Consisting of various small components, the clutch transmits engine torque to the transmission. Flywheel, Selector Fork and Collar, Synchronizers, Layshaft and Output Shaft, Gears

Image of manual transmission

Torque

Imagine that you have a big socket wrench with a 2-foot-long handle on it, and you apply 50 pounds of force to that 2-foot handle. What you are doing is applying a torque, or turning force, of 100 pound-feet (50 pounds to a 2-foot-long handle) to the bolt. You could get the same 100 pound-feet of torque by applying 1 pound of force to the end of a 100-foot handle or 100 pounds of force to a 1-foot handle.

Catalytic Converters

Used in a car to convert toxins such as CO, NO, NO2 and hydrocarbons to harmless gases, like nitrogen and carbon dioxide. In the catalytic converter, there are two different types of catalyst at work, a reduction catalyst and an oxidation catalyst. Both types consist of a ceramic structure coated with a metal catalyst, usually platinum, rhodium and/or palladium. The idea is to create a structure that exposes the maximum surface area of catalyst to the exhaust stream, while also minimizing the amount of catalyst required, as the materials are extremely expensive. Some of the newest converters have even started to use gold mixed with the more traditional catalysts. Gold is cheaper than the other materials and could increase oxidation, the chemical reaction that reduces pollutants, by up to 40 percent. The reduction catalyst is the first stage of the catalytic converter. It uses platinum and rhodium to help reduce the NOx emissions. When an NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom out of the molecule and holds on to it, freeing the oxygen in the form of O2. The nitrogen atoms bond with other nitrogen atoms that are also stuck to the catalyst, forming N2. For example: 2NO => N2 + O2 or 2NO2 => N2 + 2O2 The oxidation catalyst is the second stage of the catalytic converter. It reduces the unburned hydrocarbons and carbon monoxide by burning (oxidizing) them over a platinum and palladium catalyst. This catalyst aids the reaction of the CO and hydrocarbons with the remaining oxygen in the exhaust gas. For example: 2CO + O2 => 2CO2 There are two main types of structures used in catalytic converters -- honeycomb and ceramic beads. Most cars today use a honeycomb structure. The third stage of conversion is a control system that monitors the exhaust stream, and uses this information to control the fuel injection system. There is an oxygen sensor mounted upstream of the catalytic converter, meaning it is closer to the engine than the converter. This sensor tells the engine computer how much oxygen is in the exhaust. The engine computer can increase or decrease the amount of oxygen in the exhaust by adjusting the air-to-fuel ratio. This control scheme allows the engine computer to make sure that the engine is running at close to the stoichiometric point, and also to make sure that there is enough oxygen in the exhaust to allow the oxidization catalyst to burn the unburned hydrocarbons and CO. The catalytic converter does a great job at reducing the pollution, but it can still be improved substantially. One of its biggest shortcomings is that it only works at a fairly high temperature. When you start your car cold, the catalytic converter does almost nothing to reduce the pollution in your exhaust. One simple solution to this problem is to move the catalytic converter closer to the engine. This means that hotter exhaust gases reach the converter and it heats up faster, but this may also reduce the life of the converter by exposing it to extremely high temperatures. Most carmakers position the converter under the front passenger seat, far enough from the engine to keep the temperature down to levels that will not harm it. Preheating the catalytic converter is a good way to reduce emissions. The easiest way to preheat the converter is to use electric resistance heaters. Unfortunately, the 12-volt electrical systems on most cars don't provide enough energy or power to heat the catalytic converter fast enough. Most people would not wait several minutes for the catalytic converter to heat up before starting their car. Hybrid cars that have big, high-voltage battery packs can provide enough power to heat up the catalytic converter very quickly. Catalytic converters in diesel engines do not work as well in reducing NOx. One reason is that diesel engines run cooler than standard engines, and the converters work better as they heat up. Some of the leading environmental auto experts have come up with a new system that helps to combat this. They inject a urea solution in the exhaust pipe, before it gets to the converter, to evaporate and mix with the exhaust and create a chemical reaction that will reduce NOx. Urea, also known as carbamide, is an organic compound made of carbon, nitrogen, oxygen and hydrogen. It's found in the urine of mammals and amphibians. Urea reacts with NOx to produce nitrogen and water vapor, disposing more than 90 percent of the nitrogen oxides in exhaust gases. All over the country, SUVs and trucks are becoming targets for opportunists looking to cash in on the valuable precious metals used inside catalytic converters. A standard catalytic converter contains several hundred dollars worth of platinum, palladium and rhodium. The ground clearance on trucks and SUVs makes for easy access to the converters, so all a thief needs is a reciprocating saw and about 60 seconds. This trend has police on the lookout in many parts of the country where this kind of theft has been a problem. Police caution SUV and truck drivers to park in busy, well-lit areas.

full circle

360 degrees arriving back at the starting point through a series of developments that lead back to the original source, position, or situation or to a complete reversal of the original position —usually used in the phrase come full circle.

Collatz conjecture

3n + 1 = 1 Some lame math party trick no one has found a solution to. Lothar Collatz likely posed the eponymous conjecture in the 1930s. The problem sounds like a party trick. Pick a number, any number. If it's odd, multiply it by 3 and add 1. If it's even, divide it by 2. Now you have a new number. Apply the same rules to the new number. The conjecture is about what happens as you keep repeating the process.

estuaries

A bay or drowned valley where a river empties into the sea brackish water

Cam engine

A cam engine is a reciprocating engine where, instead of the conventional crankshaft, the pistons deliver their force to a cam that is then caused to rotate. The output work of the engine is driven by this cam. Cam engines have been a success. The first engine to get an airworthiness certificate from the United States government was, in fact, a radial cam engine. A variation of the cam engine, the swashplate engine (also the closely related wobble-plate engine), was briefly popular. These are generally thought of as internal combustion engines, although they have also been used as hydraulic- and pneumatic motors. Hydraulic motors, particularly the swashplate form, are widely and successfully used. Internal combustion engines, though, remain almost unknown. Some cam engines are two-stroke engines, rather than four-stroke. Two modern example are the KamTech and Earthstar, both radial-cam engines. In a two-stroke engine, the forces on the piston act uniformly downwards, throughout the cycle. In a four-stroke engine, these forces reverse cyclically: In the induction phase, the piston is forced upwards, against the reduced induction depression. The simple cam mechanism only works with a force in one direction. In the first Michel engines, the cam had two surfaces, a main surface on which the pistons worked when running and another ring inside this that gave a desmodromic action to constrain the piston position during engine startup. Usually, only one cam is required, even for multiple cylinders. Most cam engines were thus opposed twin or radial engines. An early version of the Michel engine was a rotary engine, a form of radial engine where the cylinders rotate around a fixed crank.

Clutch

A clutch is a mechanical device which engages and disengages power transmission especially from driving shaft to driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts.

Desmodromic valve

A desmodromic valve is a reciprocating engine poppet valve that is positively closed by a cam and leverage system, rather than by a more conventional spring. The valves in a typical four-stroke engine allow the air/fuel mixture into the cylinder at the beginning of the cycle and exhaust gases to be expelled at the end of the cycle. In a conventional four-stroke engine valves are opened by a cam and closed by return spring. An engine using desmodromic valves has two cams and two actuators, each for positive opening and closing without a return spring.

Opposed-piston engine

An opposed-piston engine is a piston engine in which each cylinder has a piston at both ends, and no cylinder head. Petrol and diesel opposed-piston engines have been used, mostly in large scale applications such as ships, military tanks and in factories. Compared to contemporary two-stroke engines which used a conventional design of one piston per cylinder, the advantages of the opposed-piston engine were: - Eliminating the cylinder head and valvetrain, which reduces weight, complexity, cost, heat loss and friction loss of the engine. - Creating a uniflow-scavenged movement of gas through the combustion chamber, which avoided the drawbacks associated with the contemporary crossflow-scavenged designs (however later advancements have provided methods for achieving uniflow scavenging in conventional piston engine designs). Also released in 1954 was the Napier Deltic engine military boats. It uses three crankshafts, one at each corner, to form the three banks of double-ended cylinders arranged in an equilateral triangle. The Deltic engine was later British Rail Class 55 and British Rail Class 23 locomotives and to power fast patrol boats and Royal navy mine sweepers.

Antoni Gaudí

Antoni Gaudí i Cornet was a Catalan architect known as the greatest exponent of Catalan Modernism. Gaudí's works have a highly individualized, one-of-a-kind style. Most are located in Barcelona, including his main work, the church of the Sagrada Família.

low bandwidth

Bandwidth describes the maximum data transfer rate of a network or Internet connection. It measures how much data can be sent over a specific connection in a given amount of time. ... Similarly, a download will finish much faster when you have a high-bandwidth connection rather than a low-bandwidth connection.

How Diesel Two-Stroke Engines Work

If you read How Two-stroke Engines Work, you learned that one big difference between two-stroke and four-stroke engines is the amount of power the engine can produce. The spark plug fires twice as often in a two-stroke engine -- once per every revolution of the crankshaft, versus once for every two revolutions in a four-stroke engine. This means that a two-stroke engine has the potential to produce twice as much power as a four-stroke engine of the same size. The two-stroke engine article also explains that the gasoline engine cycle, where gas and air are mixed and compressed together, is not really a perfect match for the two-stroke approach. The problem is that some unburned fuel leaks out each time the cylinder is recharged with the air-fuel mixture. (See How Two-stroke Engines Work for details.) It turns out that the diesel approach, which compresses only air and then injects the fuel directly into the compressed air, is a much better match with the two-stroke cycle. Many manufacturers of large diesel engines therefore use this approach to create high-power engines. At the top of the cylinder are typically two or four exhaust valves that all open at the same time. There is also the diesel fuel injector (shown above in yellow). The piston is elongated, as in a gasoline two-stroke engine, so that it can act as the intake valve. At the bottom of the piston's travel, the piston uncovers the ports for air intake. The intake air is pressurized by a turbocharger or a supercharger (light blue). The crankcase is sealed and contains oil as in a four-stroke engine. The two-stroke diesel cycle goes like this: - When the piston is at the top of its travel, the cylinder contains a charge of highly compressed air. Diesel fuel is sprayed into the cylinder by the injector and immediately ignites because of the heat and pressure inside the cylinder. - The pressure created by the combustion of the fuel drives the piston downward. This is the power stroke. - As the piston nears the bottom of its stroke, all of the exhaust valves open. Exhaust gases rush out of the cylinder, relieving the pressure. - As the piston bottoms out, it uncovers the air intake ports. Pressurized air fills the cylinder, forcing out the remainder of the exhaust gases. - The exhaust valves close and the piston starts traveling back upward, re-covering the intake ports and compressing the fresh charge of air. This is the compression stroke. - As the piston nears the top of the cylinder, the cycle repeats with step 1. From this description, you can see the big difference between a diesel two-stroke engine and a gasoline two-stroke engine: In the diesel version, only air fills the cylinder, rather than gas and air mixed together. This means that a diesel two-stroke engine suffers from none of the environmental problems that plague a gasoline two-stroke engine. On the other hand, a diesel two-stroke engine must have a turbocharger or a supercharger, and this means that you will never find a diesel two-stroke on a chain saw -- it would simply be too expensive.

What is the difference between a gasoline engine and a diesel engine?

In a diesel engine, there is no spark plug. Instead, diesel fuel is injected into the cylinder, and the heat and pressure of the compression stroke cause the fuel to ignite. Diesel fuel has a higher energy density than gasoline, so a diesel engine gets better mileage.

electric powertrain

In a motor vehicle, the powertrain or powerplant comprises the main components that generate power and deliver that power to the road surface, water, or air. This includes the engine, transmission, drive shafts, differentials, and the final drive (drive wheels, continuous track (as in military tanks or caterpillar tractors), propeller, etc.). Hybrid powertrains also include one or more electric traction motors that operate to drive the vehicle wheels. All-electric vehicles ("electric cars") eliminate the engine altogether, relying solely on electric motors for propulsion. Powertrain of a modern automobile, comprising engine, torque converter or flywheel, transmission, drive shaft, suspension and the wheels. This specific powertrain features all-wheel drive. A motor vehicle's driveline or drivetrain consists of the parts of the powertrain excluding the engine. It is the portion of a vehicle, after the prime mover, that changes depending on whether a vehicle is front-wheel, rear-wheel, or four-wheel drive, or less-common six-wheel or eight-wheel drive. In a wider sense, the powertrain includes all of the components used to transform stored (chemical, solar, nuclear, kinetic, potential, etc.) energy into kinetic energy for propulsion purposes. This includes the utilization of multiple power-sources and non-wheel-based vehicles.

What is a choke?

In an internal combustion engine, a choke valve modifies the air pressure in the intake manifold, thereby altering the ratio of fuel and air quantity entering the engine. Choke valves are generally used in naturally aspirated engines with carburetors to supply a richer fuel mixture when starting the engine. Restricts air flow allowing more fuel to enter upon startup.

Split-single engine

In internal combustion engines, a split-single design is a type of two-stroke where two cylinders share a single combustion chamber. The first production split-single engine was built from 1918 and the design was used on several motorcycles and cars until the mid 1950s, although one company continued producing split-single engines for motorcycles until 1970. During this time, the design was also occasionally used for engines with four or more cylinders.

What is the difference between a two-stroke and a four-stroke engine?

Most chainsaws and boat motors use two-stroke engines. A two-stroke engine has no moving valves, and the spark plug fires each time the piston hits the top of its cycle. A hole in the lower part of the cylinder wall lets in gas and air. As the piston moves up it is compressed, the spark plug ignites combustion, and exhaust exits through another hole in the cylinder. You have to mix oil into the gas in a two-stroke engine because the holes in the cylinder wall prevent the use of rings to seal the combustion chamber. Generally, a two-stroke engine produces a lot of power for its size because there are twice as many combustion cycles occurring per rotation. However, a two-stroke engine uses more gasoline and burns lots of oil, so it is far more polluting.

push mower how it works?

Push, or walk-behind, mowers commonly feature a pulling mechanism that is designed to turn the crank shaft and start the lawn mower engine. Most rotary lawn mowers are powered by an internal combustion engine, which runs on either two cycles or four. Two-cycle motors burn a mixture of gasoline and oil, while four-cycle motors burn gasoline and have a separate lubrication system. The blade typically spins at 3,000 revolutions per minute and slices the grass as it passes over it. Blade is connected to the crankshaft. When you pull the starting string on the mower it rotates the crankshaft to get the piston started. A flywheel is also connected to the crankshaft and there is are permanent magnets in the flywheel so as it rotates past the ignition coil it will generate a voltage for the spark plug to ignite fuel in the cylinder.

Rack and Pinion Gears

Rack and pinion gears are used to convert rotation into linear motion. A perfect example of this is the steering system on many cars. The steering wheel rotates a gear which engages the rack. As the gear turns, it slides the rack either to the right or left, depending on which way you turn the wheel.

Spanish flu

The 1918 influenza pandemic was an unusually deadly influenza pandemic, the first of the two pandemics involving H1N1 influenza virus. It infected 500 million people around the world, including people on remote Pacific islands and in the Arctic.

Ulfberht

The Ulfberht swords are a group of medieval swords found in Europe, dated to the 9th to 11th centuries, with blades inlaid with the inscription +VLFBERH+T or +VLFBERHT+. That word is a Frankish personal name that became the basis of a trademark of sorts, used by multiple bladesmiths for several centuries. The secret to Ulfberht swords was the distribution of carbon in the blade. Steel swords were made by mixing iron and carbon to produce steel. ... The process involved using trace amounts of other minerals and heating them together with iron and carbon in a crucible to produce first-rate steel. The swords are at the transitional point between the Viking sword and the high medieval knightly sword. Most have blades of Oakeshott type X. They are also the starting point of the much more varied high medieval tradition of blade inscriptions. The reverse sides of the blades are inlaid with a geometric pattern, usually a braid pattern between vertical strokes. There are also numerous blades which have this type of geometric pattern but no Vlfberht inscription.[5]

critical loads

The amount of added nutrient, usually nitrogen or phosphorus, that can be absorbed by plants without damaging ecosystem integrity. Monitoring acid deposition helps determine critical loads, or the amount of pollutants an ecosystem can support before damage. Accurate critical loads help set effective targets for SO2 and NOx reductions.

installation art

The combining of elements into a singular artwork that is specifically located in one place; an artwork that exists only in the place in which it was/is installed, and is not able to be relocated like a painting or print. Installation art is an artistic genre of three-dimensional works that often are site-specific and designed to transform the perception of a space.

compression ratio of engine

The compression ratio is the ratio of the volume of the cylinder and the combustion chamber when the piston is at the bottom, and the volume of the combustion chamber when the piston is at the top. Automotive engineers can improve fuel efficiency and fuel economy by designing engines with high compression ratios. Compression ratios usually range from 8:1 to 10:1. A higher compression ratio -- say, from 12:1 to 14:1 -- means higher combustion efficiency. Higher compression ratios and combustion efficiency mean more power with less fuel, and fewer exhaust gases. By definition, the compression ratio is the total swept volume of the cylinder with the piston at bottom dead center (BDC), divided by the total compressed volume with the piston at top dead center (TDC).

Twin-turbo

Twin-turbo refers to an engine in which two turbochargers compress the intake fuel/air mixture (or intake air, in the case of a direct-injection engine). The most common layout features two identical turbochargers in parallel; other twin-turbo layouts include sequential and staged turbocharging. A parallel configuration refers to using two equally-sized turbochargers which each receive half of the exhaust gases. Some designs combine the intake charge from each turbocharger into a single intake manifold, while others use a separate intake manifold for each turbocharger. Parallel configurations are well suited to V6 and V8 engines, since each turbocharger can be assigned to one cylinder bank, reducing the amount of exhaust piping needed. In this case, each turbocharger is fed exhaust gases by a separate exhaust manifold. For four-cylinder engines and straight-six engines, both turbochargers can be mounted to a single exhaust manifold. Staged turbocharging (also called "serial turbocharging") is where the turbochargers are connected in series with the output of the first turbocharger then being further compressed by the second turbocharger. A sequential turbo can also be of use to a system where the output pressure must be greater than can be provided by a single turbo, commonly called a staged twin-turbo system. In this case, multiple similarly sized turbochargers are used in sequence, but both operate constantly. The first turbo boosts provides the initial compression (for example to three times the intake pressure). Subsequent turbos take the charge from the previous stage and compress it further (for example to an additional three times intake pressure, for a total boost of nine times atmospheric pressure). A downside of staged turbocharging is that it often leads to large amounts of turbo lag,[8] therefore it is mostly used on piston engine aircraft which usually do not need to rapidly raise and lower engine speed. (and thus where turbo lag is not a primary design consideration), and where the intake pressure is quite low due to low atmospheric pressure at altitude, requiring a very high pressure ratio. High-performance diesel engines also sometimes use this configuration,[9] since diesel engines do not suffer from pre-ignition issues and can therefore use high boost pressures.

twin turbo engine

Twin-turbo refers to an engine in which two turbochargers compress the intake fuel/air mixture. The most common layout features two identical turbochargers in parallel; other twin-turbo layouts include sequential and staged turbocharging.

dynamometer

an instrument which measures the power output of an engine. If you want to know the horsepower of an engine, you hook the engine up to a dynamometer. A dynamometer places a load on the engine and measures the amount of power that the engine can produce against the load. Similarly, if you attach a shaft to an engine, the engine can apply torque to the shaft. A dynamometer measures this torque. You can easily convert torque to horsepower by multiplying torque by rpm/5,252. What dynamometers actually measure is torque (in pound-feet), and to convert torque to horsepower you simply multiply torque by rpm/5,252. If you plot the horsepower versus the rpm values for the engine, what you end up with is a horsepower curve for the engine. A typical horsepower curve for a high-performance engine might look like this (this happens to be the curve for the 300-horsepower engine in the Mitsubishi 3000 twin-turbo): What a graph like this points out is that any engine has a peak horsepower -- an rpm value at which the power available from the engine is at its maximum. An engine also has a peak torque at a specific rpm.

hell or high water

come hell or high water. informal. If you say that you will do something come hell or high water, you mean that you are determined to do it, despite any difficulties that there might be: I'll get you to the airport by noon, come hell or high water! you'll do something no matter what

played all the right notes

did everything correct to manipulate someone

barbiturate

drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment an addictive depressant used to relieve anxiety or induce sleep organic compound having powerful soporific effect; overdose can be fatal Type of sedative

somatotonia

energetic desire for adventure and physical activity a pattern of temperament that is marked by predominance of physical over social or intellectual factors, aggressiveness, love of physical activity, vigor, and alertness — compare cerebrotonia, viscerotonia.

smoke and mirrors

false impressions, deceit, trickery the obscuring or embellishing of the truth of a situation with misleading or irrelevant information.

unnerved

filled with apprehension; deprived of courage and strength To be unnerved is to lose courage or become uneasy. You might think you want to try bungee jumping, only to feel unnerved once you're standing on the edge of a bridge preparing to jump.

self-inquiry

gives you the tools to explore the hidden quadrants of your being as well as those blind and unknown aspects of self and draw them into the open asking questions of yourself in search of a possible topic introspection