Vocab v46

tributary

a river or stream flowing into a larger river or lake.

tomography

a technique for displaying a representation of a cross section through a human body or other solid object using X-rays or ultrasound. Tomography is imaging by sections or sectioning, through the use of any kind of penetrating wave. The method is used in radiology, archaeology, biology, atmospheric science, geophysics, oceanography, plasma physics, materials science, astrophysics, quantum information, and other areas of science

who were the huns

a tribe of nomads from Asia who pushed the Visigoths into Roman territory The Huns were a nomadic people who lived in Central Asia, the Caucasus, and Eastern Europe, between the 4th and 6th century AD. ... In 451, the Huns invaded the Western Roman province of Gaul, where they fought a combined army of Romans and Visigoths at the Battle of the Catalaunian Fields, and in 452 they invaded Italy.

shield volcano

a wide, gently sloping mountain made of layers of lava and formed by quiet eruptions a broad domed volcano with gently sloping sides, characteristic of the eruption of fluid, basaltic lava. what all volcanoes on mars are

hyperhidrosis

abnormal condition of excessive sweat excessive sweating

hypertension

abnormally high blood pressure

arrested development

an abnormal state in which development has stopped e.g. mars: it started off with water, an atmosphere, a hot core, etc. but over time something happened that caused the water to leave which took away the atmosphere and the core cooled rapidly to stop the dynamo from maintaining the protective magnetic field

smut

an offensive or indecent word or phrase

blackbox

any complex piece of equipment, typically a unit in an electronic system, with contents that are mysterious to the user.

rheumatism

any disease marked by inflammation and pain in the joints, muscles, or fibrous tissue, especially rheumatoid arthritis.

impulse

change in momentum force * time F*t = m(v1 - v0)

cerebrospinal fluid (CSF)

circulates throughout the brain and spinal cord Cerebrospinal fluid (CSF) is a clear, colorless body fluid found in the brain and spinal cord. It is produced by specialised ependymal cells in the choroid plexuses of the ventricles of the brain, and absorbed in the arachnoid granulations. There is about 125mL of CSF at any one time, and about 500 mL is generated every day. CSF acts as a cushion or buffer, providing basic mechanical and immunological protection to the brain inside the skull. CSF also serves a vital function in the cerebral autoregulation of cerebral blood flow. CSF is derived from blood plasma and is largely similar to it, except that CSF is nearly protein-free compared with plasma and has some different electrolyte levels. Due to the way it is produced, CSF has a higher chloride level than plasma, and an equivalent sodium level. CSF contains approximately 0.3% plasma proteins, or approximately 15 to 40 mg/dL, depending on sampling site.[6] In general, globular proteins and albumin are in lower concentration in ventricular CSF compared to lumbar or cisternal fluid.[7] This continuous flow into the venous system dilutes the concentration of larger, lipid-insoluble molecules penetrating the brain and CSF.[8] CSF is normally free of red blood cells, and at most contains only a few white blood cells. Any white blood cell count higher than this constitutes pleocytosis.[9] CSF contains nucleic acids, in particular cell-free DNA.[10]

Bio-ink

extracellular matrix environment to support the adhesion, proliferation, and differentiation of living cells. Bioinks distinguish themselves from traditional biomaterials such as hydrogels, polymer networks, and foam scaffolds due to their ability to be deposited as filaments during an additive manufacturing process.[1] Additionally, unlike traditional additive manufacturing materials such as thermoplastic polymers, ceramics, and metals which require the use of harsh solvents, cross-linking modalities and high temperatures to be printed, bioinks are processed under much milder conditions. These mild conditions are necessary to preserve compatibility with living cells, and prevent degradation of bioactive molecules and macroproteins. These bioinks are often adopted from existing hydrogel biomaterials and derived from natural polymers such as gelatins, alginates, fibrin, chitosan, and hyaluronic acids that are sensitive to their processing conditions. Unlike the thermoplastics that are often utilized in traditional 3D printing, the chain entanglements and ionic interactions within the hydrogel-like [3] bioink rather than temperature dominate shape fidelity. The natural derivation of many bioinks often results in a high water content and sensitivity to harsh processing conditions.[4] Therefore, bioink filaments are often deposited at or below human body temperature and under mild conditions to preserve bioink printability. Additional considerations must be taken into account when printing bioinks blended with a cell suspension due to the need to preserve cell viability.

concordant

harmonious, agreeing in agreement; consistent.

what is the retina made of?

The retina is made up of 200 million neurons. The retina contains photoreceptors that absorb light and then transmits those signals through the optic nerve to the brain. The photoreceptors in the retina are called rods and cones. Our retina contains 120 million rods and about 6 million cone photoreceptors. We have three types of cones: blue, green, and red. The human eye only has about 6 million cones. Many of these are packed into the fovea, a small pit in the back of the eye that helps with the sharpness or detail of images. Other animals have different numbers of each cell type

air flow increases evaporation

The speed at which air flows over the surface of water affects the rate at which the water evaporates. As the wind blows, it sweeps away airborne water particles that are in the air. The humidity of the air in the region of this evaporation is reduced, which allows more water molecules to dissipate into the air.

load shifting

The transfer of an electric load, or need, from on peak time to off peak time Load shifting essentially moves electricity consumption from one time period to another. For example, postponing an industrial process to another time. The idea is that by shifting the load to another time, the returns generated through energy cost savings or DSR participation are greater than the loss of production

Lipochrome

The type and amount of pigmentation in the iris determines the colour. There are two types of pigment cells. The first type is called eumelanin and the second one is called pheomelanin (or lipochrome). ... When your stroma (iris) contains only a small amount of the eumelanin cells, chances are high you will have blue eyes. Lipochrome is a naturally occurring fat-soluble pigment. Lipofuscin, a product of fat breakdown in lysosomes is a type of lipochrome that is associated with the decomposition of cell membranes.

echolalia

The uncontrollable and immediate repetition of words spoken by another person

Olympus mons

The volcano has a height of nearly 22 km (13.6 mi or 72,000 ft) as measured by the Mars Orbiter Laser Altimeter (MOLA). Olympus Mons is about two and a half times Mount Everest's height above sea level. 440 mile diameter Shield volcano. Got so big because mars has no plate tectonics

what is rat poison made of?

There are four common active ingredients in mouse and rat poisons: long-acting anticoagulants, cholecalciferol, bromethalin, and phosphides. Long-acting anticoagulants (LAACs) are the most common and well known type of mouse and rat poisons. This type of poison prevents the blood from clotting, resulting in internal bleeding. Long-acting anticoagulants work similarly to the "blood thinner" medications that people take (e.g., warfarin or Coumadin®). When dogs or cats ingest LAACs, it typically takes 3-5 days before signs of poisoning are visible. However, if the pet has been chronically exposed to the product, the onset of clinical signs may be sooner. Common signs of poisoning include signs of internal bleeding: lethargy, exercise intolerance, coughing, difficulty breathing (due to bleeding into the lungs), weakness, and pale gums. Less common signs include vomiting, diarrhea (with or without blood), nose bleeds, bruising, bloody urine, swollen joints, inappetence, and bleeding from the gums. Cholecalciferol is one of the most potent mouse and rat poisons on the market. When ingested in toxic amounts, cholecalciferol, or activated vitamin D3, can cause life-threatening elevations in blood calcium and left untreated can result in kidney failure. Common signs of poisoning may not be evident for 1-3 days, when the poison has already resulted in significant and potentially permanent damage to the body. Increased thirst and urination, weakness, lethargy, decreased appetite, and vomiting may be seen. Acute kidney failure usually develops 2-3 days after ingestion of this type of mouse and rat poison. Mouse and rat poisons containing bromethalin cause swelling of the brain which results in neurological symptoms when ingested in toxic amounts. Unlike the long-acting anticoagulant (LAAC) mouse and rat poisons, this type of bait does not cause bleeding and is not treated with vitamin K1. Common signs of bromethalin poisoning include lethargy, weakness, incoordination (ataxia), tremors, seizures, paralysis, and eventually death. Unfortunately, this type of mouse and rat poison does not have an antidote and cause serious and long-lasting effects. Treatment includes decontamination, IV fluids, and specific drugs to decrease brain swelling. Cats are more sensitive to bromethalin than dogs. As this type of mouse and rat poison has a narrow margin of safety and no antidote, prompt therapy is often needed in all species. Phosphides are found in certain types of mouse and rat poison or in mole or gopher baits. Phosphides work by releasing deadly phosphine gas, which is produced when the poison mixes with stomach acid. Food in the stomach will increase the amount of gas produced and, therefore, increase the toxicity of phosphide poisoning. Therefore, do not feed your dog or cat after they get into this type of poison. Clinical signs seen from phosphides include drooling, nausea, stomach bloating, vomiting, abdominal pain, shock, collapse, seizures, liver damage, lung damage, and even death.

Light emitting diode dental curing lights

These curing lights use one or more light-emitting diodes [LEDs] and produce blue light that cures the dental material. LEDs as light-curing sources were first suggested in the literature in 1995.[8] A short history of LED curing in dentistry was published in 2013.[9] This light uses a gallium nitride-based semiconductor for blue light emission.[6] A 2004 article in the American Dental Association's journal explained, "In LED's, a voltage is applied across the junctions of two doped semi- conductors (n-doped and p-doped), resulting in the generation and emission of light in a specific wavelength range. By controlling the chemical composition of the semiconductor combination, one can control the wavelength range. The dental LED curing lights use LED's that produce a narrow spectrum of blue light in the 400-500 nm range (with a peak wavelength of about 460 nm), which is the useful energy range for activating the CPQ molecule most commonly used to initiate the photo-polymerization of dental monomers." These curing lights are very different from halogen curing lights. They are more lightweight, portable and effective. The heat generated from LED curing lights is much less which means it does not require a fan to cool it. Since the fan was no longer needed, a more lightweight and smaller light could be designed. The portability of it comes from the low consumption of power. The LED can now use rechargeable batteries, making it much more comfortable and easier to use. The newest[when?] LED curing light cures material much faster than halogen lamps and previous LED curing lights. It uses a single high-intensity blue LED with a larger semiconductor crystal.[6] Light intensity and the illumination area has been increased with an output of 1,000 mW/cm2.[6] In order to emit such a high intensity light, it uses a highly reflective mirror film consisting of "multilayer polymer film technology". The development of the curing light greatly changed dentistry. Prior to the development of the dental curing light, different materials had to be used in order to have a resin based composite material placed in a tooth. The material used prior to this development was a self-curing resin material. These materials, an A material and a B material, were mixed separately before application. The A material was the base and the B material was the catalyst. This resin material was mixed first and then placed in the tooth. It is then self-cured/hardened fully after 30-60 seconds. This presented several issues to the dentist. One issue was that the dentist did not have control over how quickly the material cured—once mixed the curing process started. This resulted in the dentist having to quickly and properly place the material in the tooth. If the material was not properly placed, then the material had to be excavated and the process started over again. The development of this new technology gave way to new light activated resin materials. These new materials are very different from the previous ones. These materials do not need to be mixed and can be dispensed directly into the site. This new malleable resin material can only be fully cured/hardened with a dental curing light. This presents new advantages for dentists: the time constraint is now lifted and the dentist can now assure that the material is properly placed.

Alpine tundra

This biome has permafrost and is found at the top of mountains above the treeline. Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets lower until it reaches sea level, and alpine tundra merges with polar tundra.

pyruvate

Three-carbon compound that forms as an end product of glycolysis. Pyruvate is an important chemical compound in biochemistry. It is the output of the metabolism of glucose known as glycolysis. One molecule of glucose breaks down into two molecules of pyruvate, which are then used to provide further energy, in one of two ways.

all the cards are on the table

To put all your cards on the table is to be truthful and reveal your true intentions or plans without holding anything back; to be transparent, especially in business dealings or other negotiations

What does white phosphorus do to the body?

To start with, it would be good to describe what white phosphorus actually does in general terms. White phosphorus allows for significantly intense and long lasting burning. And I literally mean as intense as you can imagine (not as intense as the Sun, but you get the idea). One of the only very few ways of putting out white phosphorus is to literally starve it of oxygen. Imagine an incredibly intense burning substance, even just a small piece that gets trapped in a person. It will keep on burning, it will keep on producing intense heat until it is removed or literally suffocated while still stuck in that person (intense suffering included). Napalm works in a similar way in that it blankets a target area with fire. White phosphorus does a very similar job, but it is a whole lot more nightmarish as compared to napalm. And you can imagine how bloody terrifying napalm already is. In terms of the effect on the human body, napalm can cause the skin to literally fall away from the body. White phosphorus on the other hand, causes flesh and muscle to literally fall away from the bone. Have you ever had such wonderfully cooked meat that it just slides right off the bone? White phosphorus does that to a living human being.

can uv filters kill viruses?

UV light kills bacteria, viruses, and some cysts. It does not kill Giardia lamblia cysts or Cryptosporidium parvum oocysts, which must be removed by filtration or distillation. ... It is important to note that, although UV is an effective disinfectant, disinfection only occurs inside the unit.

Solar UV interaction with atmosphere

UV that hits water vapor in the atmosphere will break it into hydrogen and oxygen. The hydrogen will then easily escape while the oxygen will quickly combine with other elements to form oxides, ultimately falling to the ground. Does this explain all the iron oxide on mars?

watermelon snow parasite

Watermelon snow, also called snow algae, pink snow, red snow, or blood snow, is a phenomenon caused by Chlamydomonas nivalis, a species of green algae containing a secondary red carotenoid pigment (astaxanthin) in addition to chlorophyll. Unlike most species of fresh-water algae, it is cryophilic (cold-loving) and thrives in freezing water. This type of snow is common during the summer in alpine and coastal polar regions worldwide, such as the Sierra Nevada of California. Here, at altitudes of 10,000 to 12,000 feet (3,000-3,600 m), the temperature is cold throughout the year, and so the snow has lingered from winter storms. Compressing the snow by stepping on it or making snowballs leaves it looking red. Walking on watermelon snow often results in getting bright red soles and pinkish trouser cuffs.

Circle of Competence

When ego and not competence drives what we undertake, we have blind spots. If you know what you understand, you know where you have an edge over others. When you are honest about where your knowledge is lacking you know where you are vulnerable and where you can improve. Understanding your circle of competence improves decision making and outcomes.

is kg mass or weight

When we use kilograms to measure weight, we are actually referring to kgf or kilogram-force. From Wikipedia: One kilogram-force is equal to the magnitude of the force exerted by one kilogram of mass in a 9.80665 m/s2 gravitational field. In other words, the weight(force) of one kg is equal to one kgf, or 9.8N.

polycarbonate

Which of the following materials would make the safest lens in all circumstances? Plastic alternative to glass.

does terminal velocity exist in a vacuum?

"Terminal velocity" is a property of some kind of resistance. In a vacuum, there is no resistance. But it's not possible for something to accelerate indefinitely, because energy is finite. ... So it's always accelerating, but its speed is always limited by the constant change of direction of acceleration.

Homo habilis

(man of skill) first to make stone tools Homo habilis is an archaic species of Stone Age human which lived between roughly 2.1 and 1.5 million years ago, during the Early Pleistocene. The species was first discovered by anthropologists Mary and Louis Leakey at Olduvai Gorge, Tanzania in 1955, associated with the Oldowan stone tool industry.

"Action without reflection leads to burnout. Reflection without action leads to depression."

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"All the information you need is out there, all you need is the right questions to access them."

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"Any event that has a non zero probability of occurring, given infinite time, will occur"

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"Any science distinguishable from magic is insufficiently advanced."

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"Everybody just yells and screams at each other. Nobody's civil anymore! Nobody thinks what it's like to be the other guy. You think men like Thomas Wayne ever think what it's like to be someone like me? To be somebody but themselves? They don't." Civil people are hard to find nowadays. Or people with any sensibility.

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"Fear knocked...courage answered...and nothing was there." - unknown author

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"I was not proud of what I had learned, but I never doubted that it was worth knowing." - Hunter S. Thompson

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"If it feels totally safe, you are not driving fast enough."

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"The present is the key to the past."

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According to the Big Bang theory of modern cosmology, matter was created with an equal amount of anti-matter. If it had stayed that way, matter and anti-matter should have eventually met and annihilated one to one, leading up to a complete annihilation. But our existence contradicts this theory. To overcome a complete annihilation, the Universe must have turned a small amount of anti-matter into matter creating an imbalance between them. The imbalance needed is only a part in a billion. But it has remained a complete mystery when and how the imbalance was created.

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Burnout has nothing to do with expending energy in itself. To be so lucky to be in a position where one can exercise one's talents giveth at birth in leverage with opportunities presented to us throughout our lives, at pace of one's own will, is truly a blessing. To do be able to do so without the obstruction of corruption or ill deceitful power is somewhat of a miracle. Burn out comes from politics, fundings pulled, impossible requirements, vague requirements, vague hierarchy and vague role descriptions, friends turning on you, dishonor, disgrace and vendettas. As a software engineer, I'm so tired of this work hard, play hard attitude in tech. To everyone going through a tough time at work, running on a nearly empty gas tank psychologically, don't keep your head down and keep at it. It's not your company and its not worth it. Reach out and talk about it, to anyone, and you will likely find it's not you, but an error on system level.

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But the real question is what metric do you use to measure "better". If it is a vague existential concept that is not easily translatable into words, then you need to first work on that point. Because you can't succeed if you can't define success. And once you identify specific actionable issues, you can work on plans to address them. Or you may decide that what you have is good, once you have done the work to consider the options and view it objectively.

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I am not a fool, but I respect your sincerity in asking my advice. I ask you though, in listening to what I say, to remember that all advice can only be a product of the man who gives it. What is truth to one may be disaster to another. I do not see life through your eyes, nor you through mine. If I were to attempt to give you specific advice, it would be too much like the blind leading the blind. And indeed, that IS the question: whether to float with the tide, or to swim for a goal. It is a choice we must all make consciously or unconsciously at one time in our lives. So few people understand this! Think of any decision you've ever made which had a bearing on your future: I may be wrong, but I don't see how it could have been anything but a choice however indirect — between the two things I've mentioned: the floating or the swimming.

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I'm 31 and I've done this twice already. One of my friends who has also sold everything and built a new life from scratch said "the more often you start over, the longer your life feels." I don't feel younger than 31, but I don't really feel the acceleration in time that my peers talk about. I figure in life if you're privileged enough to have a chance to pursue self-actualization you choose between one of two roads: 1. competence: you get really good at something (like a career). That gets you a lot of respect and probably an enormous sense of accomplishment. 2. diversity of experience I chose #2 and because of that I'm kind of the perpetual beginner. The hardest part for me is not to beat myself up for not being successful. I've acquired so much life from living this way, I think it suits me.

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If you talk to god, you're praying, If god talks to you, you have schizophrenia.

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Jupiter's moon Io — the solar system's most volcanic world — has inspired a new way to find distant exoplanets. As the moon orbits Jupiter, it tugs on the planet's magnetic field, generating bright auroras in Jupiter's atmosphere. Even if we couldn't see Io itself, the enormous auroras, pulsing to the beat of a hidden orbiting body, would tell us that something was out there. Scientists have long suspected that a similar process might be at work with distant planets and the stars they orbit. Now, for the first time, astronomers say they have discovered an exoplanet by mapping the auroras of its host star, opening a new chapter in the quest to map the galactic menagerie of unseen worlds.

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Kinda same logic as "if you don't believe in god what's stopping you from raping and murdering everyone?" "I do rape all I want and that amount is zero. I do murder all I want and that amount is zero. The fact that these people think that if they didn't have this person watching over them that they would go on killing raping rampages is the most self damning thing I can imagine"

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Our single most valuable asset in life is time; it's the only thing you're guaranteed to run out of and you have no idea how much you have left. Seen through this lens, it was easy to drop a life that felt routine and safe for the opportunity to seek out new experiences and challenges.

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Some say that don't try to find your passion at all. Instead try to be very good at what you do (whatever that is) and the passion emerges from there. The passion lies in the details. It's hidden there, you have to dig it out.

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Some wise person said that life is all about trying different things and observing the experiences. Maybe after all it is all about experimenting a lot. Learning about the different aspects of life. Maybe the passion can be found through this journey. Maybe the meaning of one's life is actually the very process of trying to figure out the meaning of one's life.

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There isn't any purpose, you just gotta say "f**k-it" and go out and make one up.

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Whenever I've talked to people who are envious of the freedom birds have, I have to remind them that birds are free because they have no one. A bird flies wherever it wants, because no one waits for him. No one calls him and no one misses him. He is just as independent as he is unneeded. And, at the end of the day... At the end of the day, there's the evening. I mean, what are people ultimately complaining about. That they have something, some financial safety or friends that hold them to a particular place. And they dislike it. Like the best thing in the world were just wandering around aimlessly. That the glorious life is the life of a hobo. My feet have walked many white roads and they are just that. Roads that lead to places. "But I have a job, so I can't..." Leave. Simple as that. You think birds have money for food? If the winter comes too soon, if they can't find food? They die. They die free. No soup kitchen for birds. "But I have a child..." Leave. It'll hurt. Because cutting off a piece of your heart should hurt. So you have something that would hurt to leave. You have a lot. To miss or to be missed is the greatest thing. I suppose it is. I guess we all just want what we don't have. People do imagine that the world is like Skyrim, full of adventures and you are the main character. But, at the end of the day, it feels to me like a huge sandbox without a quest. You jump from planet to planet gathering resources, you walk from village to village doing odd jobs and that's it. All the spots in the world, all the places are just places, not events. Spots, not adventures. It's not the place that gives the birth to an experience. Whenever one wants to be as free as a bird, I remind him that he is. Get up and go. Just like that. But, before you do, do me a little favor I beg. Tonight walk out in the evening, sit on your porch and look at the crow sitting quietly in the tree. He has everywhere to go and he has nowhere to go. He flies for two reasons only. To find food and to find a friend. And he sleeps alone tonight, hoping for another day to trade in his freedom for something that matters. And if you closed the door behind you, don't return. Done. You are free now. Then again, as you said... Coulda been a lot worse, that's for sure.

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Yes to short and long-term goals. Especially long-term. Once you stop thinking long-term, inertia can creep in and that's when life can deal you some nasty blows that you're not prepared for.

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You want to have a leader who is a 'learn-it-all.'

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sarcastic antagonist

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specific gravity of water vapor

0.6218

specific gravity of oxygen

1.1044 sinks

Dutch auction

A Dutch auction is one of several similar types of auctions for buying or selling goods. Most commonly, it means an auction in which the auctioneer begins with a high asking price in the case of selling, and lowers it until some participant accepts the price, or it reaches a predetermined reserve price.

Xi double-charm baryon

A Xi baryon is composed of two charm quarks and one up quark. Its mass is 3621 MeV, nearly four times that of the proton.

Isoamyl acetate

A byproduct of fermentation that produces a banana or peardrop flavor. Isoamyl acetate, also known as isopentyl acetate, is an organic compound that is the ester formed from isoamyl alcohol and acetic acid. It is a colorless liquid that is only slightly soluble in water, but very soluble in most organic solvents. Isoamyl acetate has a strong odor which is also described as similar to both banana and pear.[3] Pure isoamyl acetate, or mixtures of isoamyl acetate, amyl acetate, and other flavors may be referred to as Banana oil.[4]

capsid

A capsid is the protein shell of a virus. It consists of several oligomeric structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The capsid encloses the genetic material of the virus.

101955 Bennu

A carbonaceous asteroid in the Apollo group. Has a diameter of approx. 492 m, 1614 ft. Bennu is the target of the OSIRIS-REx mission which is intended to return samples to Earth in 2023 for further study.[14][15][16] On 3 December 2018, the OSIRIS-REx spacecraft arrived at Bennu after a two-year journey.[17] Before attempting to obtain a sample from the asteroid, it will map out Bennu's surface in detail and orbit the asteroid to calculate its mass.[18]

how do electric fields accelerate particles?

A charged particle produces an electric field. This electric field exerts a force on other charged particles. Positive charges accelerate in the direction of the field and negative charges accelerate in a direction opposite to the direction of the field. Particle accelerators use electric fields to speed up and increase the energy of a beam of particles, which are steered and focused by magnetic fields. The particle source provides the particles, such as protons or electrons, that are to be accelerated

dimer

A dimer is an oligomer consisting of two monomers joined by bonds that can be either strong or weak, covalent or intermolecular. The term homodimer is used when the two molecules are identical and heterodimer when they are not. The reverse of dimerisation is often called dissociation.

Collenchyma Cell

A flexible plant cell type that occurs in strands or cylinders that support young parts of the plant without restraining growth has cell walls that range from thin to thick, providing support while still allowing the plant to grow. These cells are most common in the younger tissues of leaves and shoots. They often form into strands. Collenchyma cells are elongated cells with irregularly thick cell walls that provide support and structure. Their thick cell walls are composed of the compounds cellulose and pectin. These cells are often found under the epidermis, or the outer layer of cells in young stems and in leaf veins.

Activated carbon

A form of specially treated, porous carbon, used to absorb various odors and vapors. Activated carbon is used in methane and hydrogen storage,[1][2] air purification, solvent recovery, decaffeination, gold purification, metal extraction, water purification, medicine, sewage treatment, air filters in gas masks and respirators, filters in compressed air, teeth whitening, production of hydrogen chloride in dark and many other applications. Activated carbon is used to treat poisonings and overdoses following oral ingestion. Tablets or capsules of activated carbon are used in many countries as an over-the-counter drug to treat diarrhea, indigestion, and flatulence. However, activated charcoal shows no effect on intestinal gas and diarrhea, and is, ordinarily, medically ineffective if poisoning resulted from ingestion of corrosive agents such as alkalis and strong acids, iron, boric acid, lithium, petroleum products, or alcohol. Activated carbon will not prevent these chemicals from being absorbed into the human body.

Near-Earth object

A near-Earth object (NEO) is any small Solar System body whose orbit brings it to proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU).[2] If a NEO's orbit crosses the Earth's, and the object is larger than 140 meters (460 ft) across, it is considered a potentially hazardous object (PHO).[3] Most known PHOs and NEOs are asteroids, but a small fraction are comets.[1]

7-Dehydrocholesterol

A precursor cholesterol compound in the skin that when irradiated by sunlight produces cholecalciferol (D3). precursor of vitamin D found in the skin 7-Dehydrocholesterol is a zoosterol (a sterol produced by animals rather than plants). It is a provitamin-D. The presence of this compound in skin enables humans to manufacture vitamin D3 from ultraviolet rays via an intermediate isomer provitamin D3. It is also found in breast milk.

Casimir effect

A quantum mechanical effect, where two very large plates placed close to each other will experience an attractive force, in the absence of other forces. The cause is virtual particle-antiparticle pair creation in the vicinity of the plates. Also, the speed of light will be increased in the region between the two plates, in the direction perpendicular to them. The Casimir effect is a small attractive force that acts between two close parallel uncharged conducting plates. It is due to quantum vacuum fluctuations of the electromagnetic field. The effect was predicted by the Dutch physicist Hendrick Casimir in 1948.

Stereolithography

A rapid prototyping process that fabricates a part layer-wise by hardening a photopolymer with a guided laser beam. Stereolithography (SLA or SL; also known as stereolithography apparatus, optical fabrication, photo-solidification, or resin printing) is a form of 3D printing technology used for creating models, prototypes, patterns, and production parts in a layer by layer fashion using photochemical processes by which light causes chemical monomers and oligomers to cross-link together to form polymers.[1] Those polymers then make up the body of a three-dimensional solid. Research in the area had been conducted during the 1970s, but the term was coined by Chuck Hull in 1984 when he applied for a patent on the process, which was granted in 1986.[2] Stereolithography can be used to create prototypes for products in development, medical models, and computer hardware, as well as in many other applications. While stereolithography is fast and can produce almost any design, it can be expensive.

Parenchyma cell

A relatively unspecialized plant cell type that carries out most of the metabolism, synthesizes and stores organic products, and develops into a more differentiated cell type. most common type of plant cell, it stores ; starch, oils, and water for the plant. You can find parenchyma cells throughout a plant. These cells have thin walls and large water- filled vacuoles in the middle. Photosynthesis occurs in green chloroplasts within parenchyma cells in leaves. A generalized plant cell type, parenchyma cells are alive at maturity. They function in storage, photosynthesis, and as the bulk of ground and vascular tissues. Palisade parenchyma cells are elogated cells located in many leaves just below the epidermal tissue.

sclerenchyma cells

A rigid, supportive plant cell type usually lacking protoplasts and possessing thick secondary walls strengthened by lignin at maturity. Mature sclerenchyma cells are usually dead cells that have heavily thickened secondary walls containing lignin. The cells are rigid and nonstretchable and are usually found in nongrowing regions of plant bodies, such as the bark or mature stems.

3 knockdown rule

A rule requiring that a boxer who is knocked down three times in the same round be declared knocked out.

emphysema

A serious disease that destroys lung tissue and causes breathing difficulties. Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath due to over-inflation of the alveoli (air sacs in the lung). In people with emphysema, the lung tissue involved in exchange of gases (oxygen and carbon dioxide) is impaired or destroyed.

killer app

A software application that is so useful and popular that it fuels sales of the hardware type or operating system for which it was written. a feature, function, or application of a new technology or product which is presented as virtually indispensable or much superior to rival products.

Archimedes Cannon

A steam cannon is a cannon that launches a projectile using only heat and water, or using a ready supply of high-pressure steam from a boiler. The first steam cannon was designed by Archimedes during the Siege of Syracuse. Leonardo Da Vinci was also known to have designed one.

Ciphertext

A string of text that has been converted to a secure form using encryption.

valley network

A system of dry drainage channels on Mars that resembles the beds of rivers and tributary streams on Earth. Valley networks are branching networks of valleys on Mars that superficially resemble terrestrial river drainage basins.[1] They are found mainly incised into the terrain of the martian southern highlands, and are typically - though not always - of Noachian age (approximately four billion years old). The individual valleys are typically less than 5 kilometers wide, though they may extend for up to hundreds or even thousands of kilometers across the martian surface.

The caterpillar larvae 'plastivores' that consume and metabolize polyethylene

A team of researchers at Brandon University has found that greater wax moth caterpillar larvae are "plastivores" that are able to consume and metabolize polyethylene. In their paper published in Proceedings of the Royal Society B, the group describes their study of the caterpillars and what they learned about them and their gut microbiome. Prior research has shown that plastics are becoming a major pollutant. In addition to piling up in landfills, they are also broken down into microplastics, which are polluting the world's oceans. And while there have been some attempts to curb their use, they are still produced and used in abundance in many parts of the world. Thus, scientists have been searching for a way to force such materials to degrade faster—natural degradation takes approximately 100 years. In this new effort, the researchers studied wax moths and their larvae, which are known to invade beehives to eat the honeycombs inside. The researchers with this new effort had learned of anecdotal evidence that the larvae, which exist as caterpillars, eat low-density polyethylene. To find out if this was true, they obtained multiple caterpillars and fed them a diet of plastic grocery bags. They found that 60 of the caterpillars were able to consume approximately 30 square centimeters of the plastic in a week. They also found that the caterpillars could survive for a week eating nothing but the plastic. The researchers also studied the gut microbiomes of several of the caterpillars and identified bacteria that were involved in digesting plastic. They also allowed some of the bacteria to feast on plastic outside of the caterpillar gut and found that some of them were able to survive for up to a year eating nothing but plastic. The researchers also found that there was a symbiotic relationship between the caterpillars and their gut microbiomes—the caterpillars in conjunction with their gut bacteria were able to consume more plastics than the bacteria alone. The news was not all positive, however—the researchers also found that when the caterpillars fed on plastic, they excreted ethylene glycol, which is toxic.

hypertumor

A tumor that invades and destroys part of an previously existing tumor. Tumour: I'm about to end this man's career Hypertumor: Allow us to introduce ourselves.

Cerebral shunt

A ventriculoperitoneal (VP) shunt is a medical device that relieves pressure on the brain caused by fluid accumulation. VP shunting is a surgical procedure that primarily treats a condition called hydrocephalus. This condition occurs when excess cerebrospinal fluid (CSF) collects in the brain's ventricles.

Gas mask

Absorption is the process of being drawn into a (usually larger) body or substrate, and adsorption is the process of deposition upon a surface. This can be used to remove both particulate and gaseous hazards. Although some form of reaction may take place, it is not necessary; the method may work by attractive charges. For example, if the target particles are positively charged, a negatively charged substrate may be used. Examples of substrates include activated carbon, and zeolites. This effect can be very simple and highly effective, for example using a damp cloth to cover the mouth and nose while escaping a fire. While this method can be effective at trapping particulates produced by combustion, it does not filter out harmful gases which may be toxic or which displace the oxygen required for survival. A modern mask typically is constructed of an elastic polymer in various sizes. It is fitted with various adjustable straps which may be tightened to secure a good fit. Crucially, it is connected to a filter cartridge near the mouth either directly, or via a flexible hose. Some models contain drinking tubes which may be connected to a water bottle. Corrective lens inserts are also available for users who require them. Masks are typically tested for fit before use. After a mask is fitted, it is often tested by various challenge agents. Isoamyl acetate, a synthetic banana flavourant, and camphor are often used as innocuous challenge agents. In the military, teargases such as CN, CS, and stannic chloride in a chamber may be used to give the users confidence in the efficiency of the mask.[5]

Second-Order Thinking

Almost everyone can anticipate the immediate results of their actions. This type of first-order thinking is easy and safe but it's also a way to ensure you get the same results that everyone else gets. Second-order thinking is thinking farther ahead and thinking holistically. It requires us to not only consider our actions and their immediate consequences, but the subsequent effects of those actions as well. Failing to consider the second and third order effects can unleash disaster.

SSL

An abbreviation for Secure Sockets Layer; it is a protocol that provides security when communicating on the Internet Transport Layer Security (TLS), and its now-deprecated predecessor, Secure Sockets Layer (SSL),[1] are cryptographic protocols designed to provide communications security over a computer network.[2] Several versions of the protocols find widespread use in applications such as web browsing, email, instant messaging, and voice over IP (VoIP). Websites can use TLS to secure all communications between their servers and web browsers. The connection is private (or secure) because symmetric cryptography is used to encrypt the data transmitted. The keys for this symmetric encryption are generated uniquely for each connection and are based on a shared secret that was negotiated at the start of the session (see § TLS handshake). The server and client negotiate the details of which encryption algorithm and cryptographic keys to use before the first byte of data is transmitted (see § Algorithm below). The negotiation of a shared secret is both secure (the negotiated secret is unavailable to eavesdroppers and cannot be obtained, even by an attacker who places themselves in the middle of the connection) and reliable (no attacker can modify the communications during the negotiation without being detected).

impact winter

An impact winter is a hypothesized period of prolonged cold weather due to the impact of a large asteroid or comet on the Earth's surface. If an asteroid were to strike land or a shallow body of water, it would eject an enormous amount of dust, ash, and other material into the atmosphere, blocking the radiation from the sun. This would cause the global temperature to decrease drastically.[1][2] If an asteroid or comet with the diameter of about 5 km (3.1 mi) or more were to hit in a large deep body of water or explode before hitting the surface, there would still be an enormous amount of debris ejected into the atmosphere.[1][2][3] It has been proposed that an impact winter could lead to mass extinction, wiping out many of the world's existing species.

would an asteroid impact cause cooling?

An impact winter is a hypothesized period of prolonged cold weather due to the impact of a large asteroid or comet on the Earth's surface. If an asteroid were to strike land or a shallow body of water, it would eject an enormous amount of dust, ash, and other material into the atmosphere, blocking the radiation from the sun. This would cause the global temperature to decrease drastically.[1][2] If an asteroid or comet with the diameter of about 5 km (3.1 mi) or more were to hit in a large deep body of water or explode before hitting the surface, there would still be an enormous amount of debris ejected into the atmosphere.[1][2][3] It has been proposed that an impact winter could lead to mass extinction, wiping out many of the world's existing species.

Artificial photosynthesis

Artificial photosynthesis is a chemical process that biomimics the natural process of photosynthesis to convert sunlight, water, and carbon dioxide into carbohydrates and oxygen. The term artificial photosynthesis is commonly used to refer to any scheme for capturing and storing the energy from sunlight in the chemical bonds of a fuel (a solar fuel). Photocatalytic water splitting converts water into hydrogen and oxygen and is a major research topic of artificial photosynthesis. Light-driven carbon dioxide reduction is another process studied that replicates natural carbon fixation. Research of this topic includes the design and assembly of devices for the direct production of solar fuels, photoelectrochemistry and its application in fuel cells, and the engineering of enzymes and photoautotrophic microorganisms for microbial biofuel and biohydrogen production from sunlight. The photosynthetic reaction can be divided into two half-reactions of oxidation and reduction, both of which are essential to producing fuel. In plant photosynthesis, water molecules are photo-oxidized to release oxygen and protons. The second phase of plant photosynthesis (also known as the Calvin-Benson cycle) is a light-independent reaction that converts carbon dioxide into glucose (fuel). Researchers of artificial photosynthesis are developing photocatalysts that are able to perform both of these reactions. Furthermore, the protons resulting from water splitting can be used for hydrogen production. These catalysts must be able to react quickly and absorb a large percentage of the incident solar photons.[1] Whereas photovoltaics can provide energy directly from sunlight, the inefficiency of fuel production from photovoltaic electricity (indirect process) and the fact that sunshine is not constant throughout the day sets a limit to its use.[2][3] One way of using natural photosynthesis is for the production of a biofuel, which is an indirect process that suffers from low energy conversion efficiency (due to photosynthesis' own low efficiency in converting sunlight to biomass), the cost of harvesting and transporting the fuel, and conflicts due to the increasing need of land mass for food production.[4] The purpose of artificial photosynthesis is to produce a fuel from sunlight that can be stored conveniently and used when sunlight is not available, by using direct processes, that is, to produce a solar fuel. With the development of catalysts able to reproduce the major parts of photosynthesis, water and sunlight would ultimately be the only needed sources for clean energy production. The only by-product would be oxygen, and production of a solar fuel has the potential to be cheaper than gasoline.[5]

fastest time to run 100 miles

At 11 hours and 19 minutes, Manitowoc native Zach Bitter, recently set the world record for the 100-mile run, at a pace of 6 minutes and 48 seconds per mile.

surface tension of mercury vs water

At 20 °C: Water-air: 72.86 mN·m⁻¹ Mercury-air: 486.5 mN·m⁻¹

Backpropagation

Backpropagation, short for "backward propagation of errors," is an algorithm for supervised learning of artificial neural networks using gradient descent. Given an artificial neural network and an error function, the method calculates the gradient of the error function with respect to the neural network's weights.

what gives bananas their distinct smell?

Bananas owe their unique scent and taste to an organic compound called isoamyl acetate. It's found in several fruits—and, oddly, a small amount is produced from a bee sting—but it's especially prominent in bananas. How to make it: Isoamyl acetate is prepared by the acid catalyzed reaction (Fischer esterification) between isoamyl alcohol and glacial acetic acid as shown in the reaction equation below. Typically, sulfuric acid is used as the catalyst. What molecule is used for banana laffy taffy? For an example, let's go back to isoamyl acetate. Despite its fake taste, isoamyl acetate is found in bananas. It's generally considered to be the molecule that makes bananas so banana-flavored — your Laffy Taffy is just missing the many other flavor compounds that come with it, so it tastes one-dimensional

Why is O- the universal donor?

Because it has no antigens People with type O- blood are called universal donors because their donated red blood cells have no A, B or Rh antigens and can therefore be safely given to people of any blood group. ... Their plasma does not contain A or B antibodies and can be transfused safely to all blood types. Antigen: a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.

What is "neutrinoless double-beta decay", and why are scientists looking for it?

Beta decay is a kind of radioactive decay where a nucleus ejects an electron and an antineutrino and becomes a nucleus with one proton more and one neutron less. than the original, parent one (ok, there are other types of beta decays, but this is the most common one). This can only happen if the energy of the daughter nucleus is lower than the energy of the parent one, and the energy difference is sufficient to produce two extra particles. The antineutrino is absolutely necessary ingredient in that decay, without it the decay would break angular momentum conservation, which is considered a very fundamental law. So, no neutrinoless normal beta decay. Now add the "double". It happens, through rarely, that for a given nucleus the energy of the nucleus with one proton more and one neutron less is only slightly lower, or even higher than that of the original one, and thus normal beta decay is not possible, due to energy conservation. However a nucleus with two protons more and two neutrons less has much lower energy, the difference is sufficient to produce two electrons and two antineutrinos. In such a case a double beta decay can occur, it means that the nucleus emits simultaneously two electrons and two antineutrinos. It is rare but happens in nature. You may find a list of isotopes for which such double decay has been observed on Wikipedia: Double beta decay - Wikipedia. Now, other than in normal beta decays, in double beta decays you don't need the neutrinos to conserve angular momentum. A double beta decay without neutrinos would still violate the lepton number conservation, but well, lepton number conservation is not really a fundamental law and physicists won't be much worried if it turned out that it is violated. So: neutrinoless double beta decay is a hypothetical decay in which a nucleus emits two electrons, but no neutrinos. Why are we looking for it? It has to do with the nature of neutrinos. The only way a neutrino interacts (other than gravity) is through weak interaction. And weak interaction depends on particle spin: only left-handed neutrinos and right-handed antineutrinos interact. Right-handed neutrinos and left-handed neutrinos don't interact, from the point of view of the Standard Model they could not exist at all. This led to an idea, that right-handed neutrinos could in fact not exist — they would be identical with right-handed antineutrinos. Flipping a neutrino spin would be identical with changing it into its antiparticle. A fermion with this property is called a Majorana fermion, because it obeys Majorana equation, different from Dirac equation describing "normal" fermions, like electrons. Now, the neutrinoless double beta decay is only possible, if neutrino is a Majorana particle. Detecting it is thus a way to find out if neutrinos a Majorana - in fact it is the best way we know to find it out. That's why physicists are looking for that decay.

Camphorquinone (CPQ)

Camphorquinone, also known as 2,3-bornanedione, is a photoinitiator used in curing dental composites.[1] Polymerization is induced very slowly by camphorquinone, so amines such as N,N-dimethyl-p-toluidine, 2-ethyl-dimethylbenzoate, N-phenylglycine are generally added to increase the rate of curing. It absorbs very weakly at 468 nm (extinction coefficient of 40 M−1·cm−1) giving it a pale yellow color. Photoexcitation results in nearly quantitative formation of its triplet state through intersystem crossing and very faint fluorescence. It can be hydrolyzed by the enzyme 6-oxocamphor hydrolase.

pyrophoric

Capable of igniting spontaneously in air liable to ignite spontaneously on exposure to air. Pyrophoricity: A pyrophoric substance is a substance that ignites spontaneously in air at or below 54 °C or within 5 minutes after coming into contact with air. Examples are iron sulfide and many reactive metals including plutonium and uranium, when powdered or thinly sliced.

why is toilet paper white?

Cellulose fibers are also naturally white. The glue holding them together, however, is brown which goes away thanks to bleach, Carette says. So it's not necessarily just the process, but also the raw material that makes toilet paper white.

acceleration

Change in velocity divided by time

Deep learning

Deep learning (also known as deep structured learning or differential programming) is part of a broader family of machine learning methods based on artificial neural networks with representation learning. Learning can be supervised, semi-supervised or unsupervised. Deep learning architectures such as deep neural networks, deep belief networks, recurrent neural networks and convolutional neural networks have been applied to fields including computer vision, speech recognition, natural language processing, audio recognition, social network filtering, machine translation, bioinformatics, drug design, medical image analysis, material inspection and board game programs, where they have produced results comparable to and in some cases surpassing human expert performance. Artificial neural networks (ANNs) were inspired by information processing and distributed communication nodes in biological systems. ANNs have various differences from biological brains. Specifically, neural networks tend to be static and symbolic, while the biological brain of most living organisms is dynamic (plastic) and analog.

DeepDream

DeepDream is a computer vision program created by Google engineer Alexander Mordvintsev which uses a convolutional neural network to find and enhance patterns in images via algorithmic pareidolia, thus creating a dream-like hallucinogenic appearance in the deliberately over-processed images. insane.

Degenerate matter

Degenerate matter is a highly dense state of fermionic matter in which particles must occupy high states of kinetic energy to satisfy the Pauli exclusion principle. The description applies to matter composed of electrons, protons, neutrons or other fermions. Degenerate matter[1] is a highly dense state of fermionic matter in which particles must occupy high states of kinetic energy to satisfy the Pauli exclusion principle. The description applies to matter composed of electrons, protons, neutrons or other fermions. The term is mainly used in astrophysics to refer to dense stellar objects where gravitational pressure is so extreme that quantum mechanical effects are significant. This type of matter is naturally found in stars in their final evolutionary states, such as white dwarfs and neutron stars, where thermal pressure alone is not enough to avoid gravitational collapse. Degenerate matter is usually modelled as an ideal Fermi gas, an ensemble of non-interacting fermions. In a quantum mechanical description, particles limited to a finite volume may take only a discrete set of energies, called quantum states. The Pauli exclusion principle prevents identical fermions from occupying the same quantum state. At lowest total energy (when the thermal energy of the particles is negligible), all the lowest energy quantum states are filled. This state is referred to as full degeneracy. This degeneracy pressure remains non-zero even at absolute zero temperature.[2][3] Adding particles or reducing the volume forces the particles into higher-energy quantum states. In this situation, a compression force is required, and is made manifest as a resisting pressure. The key feature is that this degeneracy pressure does not depend on the temperature but only on the density of the fermions. Degeneracy pressure keeps dense stars in equilibrium, independent of the thermal structure of the star.

Deimos (moon)

Deimos (systematic designation: Mars II)[7] is the smaller and outermost of the two natural satellites of the planet Mars, the other being Phobos. Deimos has a mean radius of 6.2 km (3.9 mi) and takes 30.3 hours to orbit Mars.[2] Deimos is 23,460 km (14,580 mi) from Mars, much further than Mars's other moon, Phobos.[8] It is named for Deimos who in Greek mythology is the twin brother of Phobos, and personifies terror.

Why Did the Democratic and Republican Parties Switch Platforms?

During the 1860s, Republicans, who dominated northern states, orchestrated an ambitious expansion of federal power, helping to fund the transcontinental railroad, the state university system and the settlement of the West by homesteaders, and instating a national currency and protective tariff. Democrats, who dominated the South, opposed these measures. After the Civil War, Republicans passed laws that granted protections for African Americans and advanced social justice; again, Democrats largely opposed these expansions of power. Sound like an alternate universe? Fast forward to 1936. Democratic president Franklin Roosevelt won reelection that year on the strength of the New Deal, a set of Depression-remedying reforms including regulation of financial institutions, founding of welfare and pension programs, infrastructure development and more. Roosevelt won in a landslide against Republican Alf Landon, who opposed these exercises of federal power. So, sometime between the 1860s and 1936, the (Democratic) party of small government became the party of big government, and the (Republican) party of big government became rhetorically committed to curbing federal power. How did this switch happen? [How Have Tax Rates Changed Over Time?] Eric Rauchway, professor of American history at the University of California, Davis, pins the transition to the turn of the 20th century, when a highly influential Democrat named William Jennings Bryan blurred party lines by emphasizing the government's role in ensuring social justice through expansions of federal power — traditionally, a Republican stance. Republicans didn't immediately adopt the opposite position of favoring limited government. "Instead, for a couple of decades, both parties are promising an augmented federal government devoted in various ways to the cause of social justice," Rauchway wrote in a 2010 blog post for the Chronicles of Higher Education. Only gradually did Republican rhetoric drift to the counterarguments. The party's small-government platform cemented in the 1930s with its heated opposition to the New Deal. But why did Bryan and other turn-of-the-century Democrats start advocating for big government? According to Rauchway, they, like Republicans, were trying to win the West. The admission of new western states to the union in the post-Civil War era created a new voting bloc, and both parties were vying for its attention. Democrats seized upon a way of ingratiating themselves to western voters: Republican federal expansions in the 1860s and 1870s had turned out favorable to big businesses based in the northeast, such as banks, railroads and manufacturers, while small-time farmers like those who had gone west received very little. Both parties tried to exploit the discontent this generated, by promising the little guy some of the federal largesse that had hitherto gone to the business sector. From this point on, Democrats stuck with this stance — favoring federally funded social programs and benefits — while Republicans were gradually driven to the counterposition of hands-off government. From a business perspective, Rauchway pointed out, the loyalties of the parties did not really switch. "Although the rhetoric and to a degree the policies of the parties do switch places," he wrote, "their core supporters don't — which is to say, the Republicans remain, throughout, the party of bigger businesses; it's just that in the earlier era bigger businesses want bigger government and in the later era they don't." In other words, earlier on, businesses needed things that only a bigger government could provide, such as infrastructure development, a currency and tariffs. Once these things were in place, a small, hands-off government became better for business.

Elysium

Elysium or the Elysian Fields is a conception of the afterlife that developed over time and was maintained by some Greek religious and philosophical sects and cults. Initially separate from the realm of Hades, admission was reserved for mortals related to the gods and other heroes.

homomorphic encryption

Enables processing of encrypted data without the need to decrypt the data. It allows the cloud customer to upload data to a cloud service provider for processing without the requirement to decipher the data first. Homomorphic encryption is a form of encryption that allows computation on ciphertexts, generating an encrypted result which, when decrypted, matches the result of the operations as if they had been performed on the plaintext. Homomorphic encryption can be used for privacy-preserving outsourced storage and computation.

how does encryption work?

Encryption is a process that encodes a message or file so that it can be only be read by certain people. Encryption uses an algorithm to scramble, or encrypt, data and then uses a key for the receiving party to unscramble, or decrypt, the information. ... In its encrypted, unreadable form it is referred to as ciphertext.

Scientists created carbon-sucking 'Frankenstein' bricks using microbes. The material can spawn its own babies.

Engineers at the University of Colorado Boulder recently conducted an experiment that sounds almost like a kids' science project: They added colonies of green bacteria to a mix of sand and grocery-store gelatin. The microbes in the brick are cyanobacteria, which perform photosynthesis to grow, taking in carbon dioxide. They produce a powdery substance called calcium carbonate — the main ingredient in cement — which toughens the material. However, the atmosphere needs to be humid in order for the bacteria to grow. The building and construction sector is responsible for nearly 40% of the world's carbon emissions. A living brick could help offset some of this pollution, since cyanobacteria captures carbon dioxide.

Battle of Dunkirk

England saves almost all of the 350,000 troops trapped Allied forces met the Germans in Belgium, the Allies where pushed back to the beaches in Dunkirk they were rescued by private boats evacuating them across the English Channel the battle on northern french coast in which germany defeated france and britain who retreated across the english channel

size of a cell

Eukaryotic cells normally range between 1- 100µm in diameter. The mouse cells in Figure above are about 10 µm in diameter. One exception, however, is eggs. Eggs contain the largest known single cell, and the ostrich egg is the largest of them all.Dec 5, 2014

why do fans make rooms cooler?

Fans don't make a room any cooler, they merely make you feel cooler. By moving air over your skin, a fan can lower your body temperature, but will do nothing for the heat inside a room. So if you're not in the room, you're just wasting energy by leaving the fan on.

Charles Gates

First person to have home A/C installed. Charles Gilbert Gates was the son of John Warne Gates, the pioneer manufacturer of barbed wire. In July 1913 he drove from his home in Minneapolis to New York City, where he had a seat on the New York Stock Exchange. He died in Cody, Wyoming in 1913. After his death his home was completed and was the first to have air conditioning installed.

how many types of cones do mantis shrimp have?

For example, humans have three types of cones in our eyes, allowing us to see the colors red through violet. Mantis shrimp, on the other hand, have 16 types of cones. We have three types of cones: red, green, and blue.

francium

Francium is a chemical element with the symbol Fr and atomic number 87. Prior to its discovery, it was referred to as eka-caesium. It is extremely radioactive; its most stable isotope, francium-223 (originally called actinium K after the natural decay chain it appears in), has a half-life of only 22 minutes. Francium was discovered by Marguerite Perey in 1939 when she was researching the radioactive decay of actinium-227. The discovery took place at the Curie Institute in Paris. The element takes its name from the country of its discovery - France. ... She produced an ultra-pure actinium sample and studied its radiation.

Outflow channels

Geological feature on Mars that appears to have been caused by sudden flooding. Outflow channels are extremely long, wide swathes of scoured ground on Mars, commonly containing the streamlined remnants of pre-existing topography and other linear erosive features indicating sculpting by fluids moving downslope.[1] Channels extend many hundreds of kilometers in length and are typically greater than one kilometer in width; the largest valley (Kasei Vallis) is around 3,500 km (2,200 mi) long, greater than 400 km (250 mi) wide and exceeds 2.5 km (1.6 mi) in depth cut into the surrounding plains. These features tend to appear fully sized at fractures in the Martian surface, either from chaos terrains or from canyon systems or other tectonically controlled, deep graben, though there are exceptions. Besides their exceptional size, the channels are also characterized by low sinuosities and high width:depth ratios compared both to other Martian valley features and to terrestrial river channels. Crater counts indicate that most of the channels were cut since the early Hesperian,[2] though the age of the features is variable between different regions of Mars. Some outflow channels in the Amazonis and Elysium Planitiae regions have yielded ages of only tens of million years, extremely young by the standards of Martian topographic features.[3] Image: Kasei Valles, seen in MOLA elevation data. Flow was from bottom left to right. North is up. Image is approx. 1,600 km (990 mi) across. The channel system extends another 1,200 km (750 mi) south of this image to Echus Chasma.

Hydrocephalus

Hydrocephalus is a condition in which an accumulation of cerebrospinal fluid (CSF) occurs within the brain.[1] This typically causes increased pressure inside the skull. Older people may have headaches, double vision, poor balance, urinary incontinence, personality changes, or mental impairment. In babies, it may be seen as a rapid increase in head size. Other symptoms may include vomiting, sleepiness, seizures, and downward pointing of the eyes. Hydrocephalus can occur due to birth defects or be acquired later in life.[1] Associated birth defects include neural tube defects and those that result in aqueductal stenosis. Hydrocephalus is typically treated by the surgical placement of a shunt system.

does e=mc2 apply to neutrino oscillation?

If neutrinos can oscillate between types with different masses, then Einstein's equation E = mc^2, where c is the speed of light in vacuum, implies that the (rest) energy of a neutrino changes during a mass oscillation.

lowland

land, usually level, at a low elevation below sea level

Valhalla

In Norse mythology, Valhalla is a majestic, enormous hall located in Asgard, ruled over by the god Odin. Chosen by Odin, half of those who die in combat travel to Valhalla upon death, led by valkyries, while the other half go to the goddess Freyja's field Fólkvangr.

What is a displacement current in a capacitor?

In a capacitor, you always have a displacement current and never a conduction current under normal conditions (i.e. you apply a potential difference across it which is below it's specified max. voltage). Conduction currents is when electrons actually move. But in displacement current, no charge carriers are involved. It's just the variations in the electric field, which are imagined to be equivalent to a current. Capacitor contains an insulating material (called dielectric) sandwiched between two conductors. Since insulators can carry only an electric field but not moving carriers, the above paragraph is justified. However, if you apply a huge voltage across a capacitor, it behaves differently. Under sufficiently large potential differences, many insulators stop insulating. i.e. they conduct electricity. So if you apply a large voltage beyond the specified limit, the dielectric behaves as a conductor. So you get a conduction current in the capacitor. This happens just like a lightning strike, when the potential difference between the clouds and the earth becomes so large, that the atmosphere is forced to conduct and the electric flash strikes the ground. This is called breaking down of a capacitor. When a capacitor breaks down, it no longer carries displacement current. Because it's now a conductor! So, just like any other conductor, the electric field inside it is zero, and so is the displacement current. These days, you get very compact capacitors. Due to their compactness, their dielectric breaks down rather easily. For example, many of today's tiny capacitors are manufactured to function properly only up to 60V, beyond which their breakdown occurs. _____________ The way I understand it is that an electric field is equivalent to using an electron to carry the charge. In the case of a capacitor, a non-zero amount of charge carriers i.e. electrons pass through the dielectric, and instead the current is transmitted via an electric field to the opposing plate in the capacitor to continue the circuit. But now the question arises, what dictates when the capacitor will discharge? Is it just the frequency of the supply AC current? Does frequency play into what it takes to breakdown a capacitor dielectric? In other words, if you apply a high frequency will the capacitor operate with less dielectric stress and compensate for power factor worse? Or is the opposite true, high frequency = more stress? Man this stuff is confusing.

radical chemistry

In chemistry, a radical is an atom, molecule, or ion that has an unpaired valence electron. With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spontaneously dimerize. Most organic radicals have short lifetimes. A dimer is an oligomer consisting of two monomers joined by bonds that can be either strong or weak, covalent or intermolecular. The term homodimer is used when the two molecules are identical and heterodimer when they are not. The reverse of dimerisation is often called dissociation.

photocatalytic oxidation

In chemistry, photocatalysis is the acceleration of a photoreaction in the presence of a catalyst. In catalysed photolysis, light is absorbed by an adsorbed substrate. In photogenerated catalysis, the photocatalytic activity (PCA) depends on the ability of the catalyst to create electron-hole pairs, which generate free radicals (e.g. hydroxyl radicals: •OH) able to undergo secondary reactions. Its practical application was made possible by the discovery of water electrolysis by means of titanium dioxide (TiO2). The Photocatalytic Oxidation process combines UVC irradiation with a substance (catalyst) titanium dioxide (TiO2) which results in a reaction that changes malignant contaminants into water, carbon dioxide and detritus.

convolutional neural network

In deep learning, a convolutional neural network is a class of deep neural networks, most commonly applied to analyzing visual imagery. They are also known as shift invariant or space invariant artificial neural networks, based on their shared-weights architecture and translation invariance characteristics.

Displacement current

In electromagnetism, displacement current is a quantity appearing in Maxwell's equations that is defined in terms of the rate of change of electric displacement field. Displacement current has the units of electric current density, and it has an associated magnetic field just as actual currents do. In a capacitor, you always have a displacement current and never a conduction current under normal conditions (i.e. you apply a potential difference across it which is below it's specified max. voltage). Conduction currents is when electrons actually move. But in displacement current, no charge carriers are involved. It's just the variations in the electric field, which are imagined to be equivalent to a current. _______________________ In electromagnetism, displacement current density is the quantity ∂D/∂t appearing in Maxwell's equations that is defined in terms of the rate of change of D, the electric displacement field. Displacement current density has the same units as electric current density, and it is a source of the magnetic field just as actual current is. However it is not an electric current of moving charges, but a time-varying electric field. In physical materials (as opposed to vacuum), there is also a contribution from the slight motion of charges bound in atoms, called dielectric polarization. The idea was conceived by James Clerk Maxwell in his 1861 paper On Physical Lines of Force, Part III in connection with the displacement of electric particles in a dielectric medium. Maxwell added displacement current to the electric current term in Ampère's Circuital Law. In his 1865 paper A Dynamical Theory of the Electromagnetic Field Maxwell used this amended version of Ampère's Circuital Law to derive the electromagnetic wave equation. This derivation is now generally accepted as a historical landmark in physics by virtue of uniting electricity, magnetism and optics into one single unified theory. The displacement current term is now seen as a crucial addition that completed Maxwell's equations and is necessary to explain many phenomena, most particularly the existence of electromagnetic waves.

Double beta decay

In nuclear physics, double beta decay is a type of radioactive decay in which two neutrons are simultaneously transformed into two protons, or vice versa, inside an atomic nucleus. As in single beta decay, this process allows the atom to move closer to the optimal ratio of protons and neutrons. As a result of this transformation, the nucleus emits two detectable beta particles, which are electrons or positrons. The literature distinguishes between two types of double beta decay: ordinary double beta decay and neutrinoless double beta decay. In ordinary double beta decay, which has been observed in several isotopes, two electrons and two electron antineutrinos are emitted from the decaying nucleus. In neutrinoless double beta decay, a hypothesized process that has never been observed, only electrons would be emitted.

In the desert I saw a creature, naked, bestial, Who, squatting upon the ground, Held his heart in his hands, And ate of it. I said, "Is it good, friend?" "It is bitter—bitter," he answered; "But I like it "Because it is bitter, "And because it is my heart."

In the Desert BY STEPHEN CRANE

Kugelblitz

In theoretical physics, a kugelblitz (German: "ball lightning") is a concentration of heat, light or radiation so intense that its energy forms an event horizon and becomes self-trapped: according to general relativity and the equivalence of mass and energy, if enough radiation is aimed into a region, the concentration of energy can warp spacetime enough for the region to become a black hole, although this would be a black hole whose original mass-energy had been in the form of radiant energy rather than matter.[1] In simpler terms, a kugelblitz is a black hole formed from radiation as opposed to matter. Such a black hole would nonetheless have properties identical to one of equivalent mass and angular momentum formed in a more conventional way, in accordance with the no-hair theorem. The best-known reference to the kugelblitz idea in English is probably John Archibald Wheeler's 1955 paper "Geons",[2] which explored the idea of creating particles (or toy models of particles) from spacetime curvature, called geons. Wheeler's paper on geons also introduced the idea that lines of electric charge trapped in a wormhole throat might be used to model the properties of a charged particle-pair. Kugelblitz drives have been considered as possible future black hole starship engines.

Absolute hot

It's the highest possible temperature that matter can attain, according to conventional physics, and well, it's been measured to be exactly 1,420,000,000,000,000,000,000,000,000,000,000 degrees Celsius (2,556,000,000,000,000,000,000,000,000,000,000 degrees Fahrenheit) Absolute hot is a theoretical upper limit to the thermodynamic temperature scale, conceived as an opposite to absolute zero. Contemporary models of physical cosmology postulate that the highest possible temperature is the Planck temperature, which has the value 1.416785(71)×10^32 kelvin, or about 2.55×10^32 fahrenheit.[1] Above about 10^32 K, particle energies become so large that gravitational forces between them would become as strong as other fundamental forces according to current theories. There is no existing scientific theory for the behavior of matter at these energies; a quantum theory of gravity would be required.[2] The models of the origin of the universe based on the Big Bang theory assume that the universe passed through this temperature about 10^−42 s (one Planck time) after the Big Bang as a result of enormous entropy expansion.[1]

How was an atom of antimatter (anti-protons in the nuclei, positrons surrounding it) created?

Just as you can expect: take an anti-proton and let it combine with a positron to form anti-hydrogen. The biggest problem is getting antiprotons with sufficiently low energy, so you can recombine them with positrons. Positrons are easy to come by, you can get them from beta+ radioactive decay. But to get an antiproton you need to produce it in collisions of protons accelerated to very high energies with some nuclei. There is a small probability, that such a collision would produce a proton-antiproton pair, magnetic field can then be used to catch the antiprotons and form them into a beam. But, as the antiprotons are created in high energy collisions, they themselves have usually high energies, so you need to slow them down. At CERN they have built a special "inverse accelerator" called Antiproton Deceleator (AD for short) just for the purpose of slowing down antiprotons, to be able to experiment with them at low energies. But antiprotons leaving the decelerator still have too high energy, to produce antihydrogen you need to slow them down or "cool them" further. This can be done by sending the beam through thin metal foils, where antiprotons lose their energy by ionising atoms, and then mixing them with low energy electron plasma. So, once you have low energy antiprotons, you just inject them into a vacuum chamber, add positrons in, let them recombine and try to trap produced antihydrogen atoms by specially configured magnetic fields. That's what ATENA experiment has first done 15 years ago, and what the ALPHA experiment is doing now.

Kinetic diameter

Kinetic diameter is a measure applied to atoms and molecules that expresses the likelihood that a molecule in a gas will collide with another molecule. It is an indication of the size of the molecule as a target. The kinetic diameter is not the same as atomic diameter defined in terms of the size of the atom's electron shell, which is generally a lot smaller, depending on the exact definition used. Rather, it is the size of the sphere of influence that can lead to a scattering event.[1]

lignin makes wood brown

Lignin makes wood stiff and trees stand upright. It eventually turns paper yellow because of oxidation. Paper is made from wood, which is made up mainly of white cellulose. Wood also has a lot of a dark substance in it called lignin, which ends up in the paper, too, along with the cellulose.

lipofuscin

Lipofuscin is the name given to fine yellow-brown pigment granules composed of lipid-containing residues of lysosomal digestion. It is considered to be one of the aging or "wear-and-tear" pigments, found in the liver, kidney, heart muscle, retina, adrenals, nerve cells, and ganglion cells.

Maltodextrin

Maltodextrin is a polysaccharide (many carbohydrates joined together in a molecular chain) that is used as a food additive. It is produced from vegetable starch by partial hydrolysis and is usually found as a white hygroscopic spray-dried powder.

Boomerang Nebula

Measurements show the Boomerang Nebula has an incredible temperature of minus 458 degrees Fahrenheit (1 degree Kelvin). It is the coldest known object in the Universe. The nebula is colder than the faint afterglow of the Big Bang, which is the natural background temperature of space.

does water ice sublimate in space?

Melting is the process of ice turning into water. Because comets are in space, as the sun warms the ice to a sufficient temperature, the ice sublimates - meaning it turns directly into a gas.

where does the argon in the atmosphere come from?

Nearly all of the argon in the Earth's atmosphere is radiogenic argon-40, derived from the decay of potassium-40 in the Earth's crust. In the universe, argon-36 is by far the most common argon isotope, as it is the most easily produced by stellar nucleosynthesis in supernovas. Banana air bruh Argon is the third noble gas, in period 8, and it makes up about 1% of the Earth's atmosphere. Argon has approximately the same solubility as oxygen and it is 2.5 times as soluble in water as nitrogen . This chemically inert element is colorless and odorless in both its liquid and gaseous forms.

Neuroregeneration

Neuroregeneration refers to the regrowth or repair of nervous tissues, cells or cell products. Such mechanisms may include generation of new neurons, glia, axons, myelin, or synapses. Neuroregeneration differs between the peripheral nervous system (PNS) and the central nervous system (CNS) by the functional mechanisms involved, especially in the extent and speed of repair. When an axon is damaged, the distal segment undergoes Wallerian degeneration, losing its myelin sheath. The proximal segment can either die by apoptosis or undergo the chromatolytic reaction, which is an attempt at repair. In the CNS, synaptic stripping occurs as glial foot processes invade the dead synapse.[1]

Hanlon's Razor

Never attribute to malice that which is adequately explained by stupidity. Don't attribute to maliciousness that which is more easily explained by incompetence. When something bad happens to us, as egocentric humans we have a tendency to quickly judge that it was the result of malice - of some bad intent. That person that cut you off in traffic? We can often automatically assume they are a selfish jerk. But if we apply Hanlon's Razor, we might consider that maybe they are just quite an unskilled driver and possibly didn't even see us!

Peto's paradox

No correlation between body size and cancer between species (there is a correlation with in a species though i.e. dogs) Peto's paradox is the observation, named after Richard Peto, that at the species level, the incidence of cancer does not appear to correlate with the number of cells in an organism. For example, the incidence of cancer in humans is much higher than the incidence of cancer in whales.

Which noble gases form stable compounds?

Noble gas compounds are chemical compounds that include an element from the noble gases. Although the noble gases are generally nonreactive elements, many such compounds have been observed, particularly involving the element xenon. The noble gases are divided into two main groups: Reactive Noble Gases: - Krypton - Xenon - Radon Non-reactive Noble Gases: - Argon - Neon - Helium Among these noble gases, Xenon is known to form the maximum number of stable compounds. ______________________________ Xenon hexafluoride is a noble gas compound with the formula XeF6. It is one of the three binary fluorides of xenon, the other two being XeF2 and XeF4. All known are exergonic and stable at normal temperatures. XeF6 is the strongest fluorinating agent of the series. It is a colorless solid that readily sublimes into intensely yellow vapors. Xenon difluoride is a powerful fluorinating agent with the chemical formula XeF2, and one of the most stable xenon compounds. Like most covalent inorganic fluorides it is moisture-sensitive. It decomposes on contact with light or water vapor but is otherwise stable in storage. Xenon difluoride is a dense, white crystalline solid. Xenon tetrafluoride is a chemical compound with chemical formula XeF4. It was the first discovered binary compound of a noble gas. Radon difluoride (RnF2) is a compound of radon, a noble gas. Radon reacts readily with fluorine to form a solid compound, but this decomposes on attempted vaporization and its exact composition is uncertain.[1][2] Calculations suggest that it may be ionic,[3] unlike all other known binary noble gas compounds. The usefulness of radon compounds is limited because of the radioactivity of radon. The longest-lived isotope, radon-222, has a half-life of only 3.82 days, which decays by α-emission to yield polonium-218. Argon fluorohydride (systematically named fluoridohydridoargon) or argon hydrofluoride is an inorganic compound with the chemical formula HArF (also written ArHF). It is a compound of the chemical element argon. _________________ Every semester when I show my students the Lewis structure of xenon tetrafluoride: Yeah, I mean Noble gasses are certainly less reactive than the other groups, and some are virtually non reactive under reasonable conditions. But I don't know why it's perpetuated that they are entirely unreactive. Because if they have the amount of electrons they want why would they change? Because the octet rule is a lie. It's more like the octet suggestion

Armistice Day

November 11, 1918; Germany signed an armistice (an agreement to stop fighting); this US holiday is now known as Veterans Day Armistice Day is commemorated every year on 11 November to mark the armistice signed between the Allies of World War I and Germany at Compiègne, France at 5:45 am,[1] for the cessation of hostilities on the Western Front of World War I, which took effect at eleven o'clock in the morning—the "eleventh hour of the eleventh day of the eleventh month" of 1918. But, according to Thomas R. Gowenlock, an intelligence officer with the U.S. First Division, shelling from both sides continued for the rest of the day, only ending at nightfall.[2][3] The armistice initially expired after a period of 36 days and had to be extended several times. A formal peace agreement was only reached when the Treaty of Versailles was signed the following year.[4]

people used to sleep on roofs in egypt

Often during the hot months, the ancient Egyptians cooked, ate and slept on their roofs. In fact, most of their lives even during other times of the year are spent outside. The is known because most egyptian homes had doors that lead directly to their rooftops.

Unix

Operating system developed by AT&T. It is considered portable, meaning it can run on just about any hardware platform. Unix is an operating system. It supports multi-tasking and multi-user functionality. Unix is most widely used in all forms of computing systems such as desktop, laptop, and servers. On Unix, there is a Graphical user interface similar to windows that support easy navigation and support environment.

non-deterministic

Outcome cannot be predicted with certainty In computer science, a nondeterministic algorithm is an algorithm that, even for the same input, can exhibit different behaviors on different runs, as opposed to a deterministic algorithm. There are several ways an algorithm may behave differently from run to run.

red phosphorus chemical formula

P4 Elemental phosphorus can exist in several allotropes, the most common of which are white and red solids. Solid violet and black allotropes are also known. Gaseous phosphorus exists as diphosphorus and atomic phosphorus. Red, white, black. and violet are all allotropes of phosphorus. Allotrope: each of two or more different physical forms in which an element can exist. Graphite, charcoal, and diamond are all allotropes of carbon. Red phosphorus is used in the production of semiconductors, pyrotechnics, fertilizers, safety matches, pesticides, smoke bombs, incendiary shells in organic synthesis reactions and certain flame retardants. It is also used in electroluminescent coatings. Red phosphorus does not ignite in air at temperatures below 240 °C (464 °F), whereas pieces of white phosphorus ignite at about 30 °C (86 °F). ... Under standard conditions it is more stable than white phosphorus, but less stable than the thermodynamically stable black phosphorus.

Hyperparasite

Parasite that feeds on another parasite. A hyperparasite is a parasite whose host, often an insect, is also a parasite, often specifically a parasitoid. Hyperparasites are found mainly among the wasp-waisted Apocrita within the Hymenoptera, and in two other insect orders, the Diptera and Coleoptera. The most common examples are insects that lay their eggs inside or near parasitoid larvae, which are themselves parasitizing the tissues of a host, again usually an insect larva. A well-studied case is that of the small white butterfly (Pieris rapae), a serious horticultural pest of Brassica such as cabbage and Brussels sprouts. Its larvae are parasitized by the larvae of the wasps Cotesia glomerata and C. rubecula, both of which are in turn parasitized by the wasp Lysibia nana. Plant volatiles are emitted from plants as a defense against herbivory. The volatiles emitted attract parasitic wasps that in turn, attack the herbivores. Hyperparasitoids are known to find their victims through herbivore-induced plant volatiles emitted in response to attack by caterpillars that in turn had been parasitized by primary parasitoids. The larvae of parasitic wasps developing inside the caterpillar alter the composition of the oral secretions of their herbivorous host and thereby affect the cocktail of volatiles the plant produces.[7] The pupae of primary parasitoid species are parasitized by many hyperparasitoid species.

Phobos (moon)

Phobos is a small, irregularly shaped object with a mean radius of 11 km (7 mi)[1] and is seven times as massive as the outer moon, Deimos. Phobos is named after the Greek god Phobos, a son of Ares (Mars) and Aphrodite (Venus) and the personification of fear (cf. phobia). Phobos orbits 6,000 km (3,700 mi) from the Martian surface, closer to its primary body than any other known planetary moon. It is so close that it orbits Mars much faster than Mars rotates, and completes an orbit in just 7 hours and 39 minutes. As a result, from the surface of Mars it appears to rise in the west, move across the sky in 4 hours and 15 minutes or less, and set in the east, twice each Martian day. Images and models indicate that Phobos may be a rubble pile held together by a thin crust, and that it is being torn apart by tidal interactions.[9] Phobos gets closer to Mars by about 2 meters every one hundred years, and it is predicted that within 30 to 50 million years it will either collide with the planet, or break up into a planetary ring.[6] The origin of the Martian moons is still controversial.[45] Phobos and Deimos both have much in common with carbonaceous C-type asteroids, with spectra, albedo, and density very similar to those of C- or D-type asteroids.[46] Based on their similarity, one hypothesis is that both moons may be captured main-belt asteroids.[47][48] Both moons have very circular orbits which lie almost exactly in Mars's equatorial plane, and hence a capture origin requires a mechanism for circularizing the initially highly eccentric orbit, and adjusting its inclination into the equatorial plane, most probably by a combination of atmospheric drag and tidal forces,[49] although it is not clear that sufficient time is available for this to occur for Deimos.[45] Capture also requires dissipation of energy. The current Martian atmosphere is too thin to capture a Phobos-sized object by atmospheric braking.[45] Geoffrey A. Landis has pointed out that the capture could have occurred if the original body was a binary asteroid that separated under tidal forces.[48]

Do other planets have plate tectonics?

Planets without tectonic plates are known as stagnant lid planets. On these planets, the crust is one giant, spherical plate floating on mantle, rather than separate pieces. These are thought to be more widespread than planets with plate tectonics. In fact, Earth is the only planet with confirmed tectonic plates.

energy density of carbohydrates

Proteins and most carbohydrates both have about 17 kJ/g (4 kcal/g). The differing energy density of foods (fat, alcohols, carbohydrates and proteins) lies mainly in their varying proportions of carbon, hydrogen, and oxygen atoms. What is the energy density of a lithium ion battery? They have one of the highest energy densities of any battery technology today (100-265 Wh/kg or 250-670 Wh/L). 17 kJ/g = 4722 Wh/kg Carbs have INSANE energy storage potential. Could this somehow be brought to scale?

relentless.com

Relentless.com Is A Secret Way You Can Get To Amazon.com. ... In fact, he liked it so much that Amazon's actually using it. "Friends suggested that it sounded a bit sinister," Stone writes

C-type asteroid

Roughly 75 percent of the main-belt asteroids are the dark, black carbonaceous, orbiting the Sun in the outer half of the belt. One of a class of very dark asteroids whose reflectance spectra show no absorption features due to the presence of minerals. C-type (carbonaceous) asteroids are the most common variety, forming around 75% of known asteroids.[1] They are distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks and minerals. They occur most frequently at the outer edge of the asteroid belt, 3.5 astronomical units (AU) from the Sun, where 80% of the asteroids are of this type, whereas only 40% of asteroids at 2 AU from the Sun are C-type.[2] The proportion of C-types may actually be greater than this, because C-types are much darker (and therefore less detectable) than most other asteroid types except for D-types and others that are mostly at the extreme outer edge of the asteroid belt.

SSL Certificates

SSL Certificates are small data files that digitally bind a cryptographic key to an organization's details. When installed on a web server, it activates the padlock and the https protocol and allows secure connections from a web server to a browser.

why is there so much nitrogen in the atmosphere?

Scientists believe that most of the nitrogen in the air was carried out from deep inside the earth by volcanoes. The nitrogen molecule is heavier than most other molecules in the atmosphere, so it tends to settle towards the bottom. You question should perhaps be "why is therre so much nitrogen...?" Part of the answer to that is that nitrogen gas is relatively unreactive with the other materials of the earths atmosphere, oceans, and solid parts, and it's relatively abundant in the universe. Oxygen, however, reacts quickly with lots of minerals. Hydrogen and helium are too light to stick around, and others are too reactive.

what is henna made of?

You may be familiar with henna, a reddish-brown coloring made from a flowering plant that grows in tropical and subtropical regions of Africa and Asia. Since the Bronze Age, people have used dried henna, ground into a paste, to dye skin, hair, fingernails, leather, silk and wool Would be crazy to see a whole army come charging at you with henna all over their bodies

Oligomer

Short chain of monomer liquids that is often thick, sticky, and gel-like and that is not long enough to be considered a polymer. An oligomer is a molecular complex of chemicals that consists of a few repeating units, in contrast to a polymer, where the number of monomers is, in principle, infinite. Dimers, trimers, and tetramers are, for instance, oligomers composed of two, three, and four monomers, respectively.

Q&A: The Engineer Who Wants To Power The World With Carbs

You might like carbs, but probably not in the way Percival Zhang does. Zhang, a chemical engineer at Virginia Tech, runs a lab that's dedicated to converting carbohydrates into electricity. The lab's inventions include proofs of concepts showing that carbohydrates are able to power everything from cell phones to cars. "In my personal view, I think carbohydrates are some of the best chemical compounds for energy storage," he says. "Nature chose this one already." He means that living things, including humans, break down molecules of carbohydrates when they need energy to breathe, eat and generally do all the things organisms do. On the other hand, most of humanity's inventions run on the energy that comes from breaking down molecules called hydrocarbons, which are found in coal, natural gas, and crude oil. Just last week, Zhang his colleagues debuted a prototype battery that uses maltodextrin, a carbohydrate that often goes into processed foods, as its source of electrons for producing electricity. Other labs have created carbohydrate-based batteries before, but the Zhang lab model extracts a high number of electrons, resulting in a battery that lasts longer. The battery is at least a few years away from being market-ready, but if such technology does become viable in the future, its makers hope it could be an environmentally friendly replacement for the batteries in smartphones and other small devices. The basic idea is, we want to use sugar because sugar is the most renewable carbon compound. So sugar is very good, but can we extract all its energy and convert it to electricity? We designed a special enzyme pathway so, for the first time, we can extract 24 electrons per glucose molecule to convert to electricity. Then we can use this electricity to power portable devices. PS: You've also worked on using carbohydrates to make fuel cells in electric cars and biofuels that can go into internal combustion engines. You can do all this with enzymes? YZ: Yes, most of the time, we use enzymes in our research. We use enzymes to mimic the energy-producing reactions of microorganisms, but when you use only enzymes, you put many enzymes together in a pathway that is not available in nature, and you can do much better than microorganisms. We do a lot of reactions microorganisms cannot do. For example, like in this sugar battery case, we use enzymes to extract all of the energy. If you try to use a microorganism, the microorganism will duplicate himself and waste a lot of energy. He will not produce as much electricity as we can now. PS: Do you use enzymes that appear in nature, or do you design your own with synthetic biology? YZ: For now, we use enzymes from natural organisms. As the next step, we will engineer enzymes. That will work much better. PS: Is there anything else we would be able to do if we had the technology to convert carbohydrates to electricity and vice versa? YZ: The big issue with solar and wind energy is how to store it. So our idea is that in times when you have so much electricity, we can try to generate sugar, because sugar is a chemical compound. You can store sugar for a long time. When you need electricity, you can convert sugar to electricity through a sugar battery. There are so many competing ideas for storing energy from solar and wind. In my personal view, I think carbohydrates are some of the best chemical compounds for energy storage because nature chose this one already. ________________ Far future: Even if we wouldn't be able to make these batteries last for a long period of time, being that it is biologically based, and bio-3D printers exist, it is very possible that you could just 3D print one of these on your own whenever the battery fails. It really seems like storage is moving towards more biological means with DNA data storage and now carb based battery storage. But tbh, it makes sense. Why reinvent the processes with silicon when nature has already succeeded with carbon? Former Virginia Tech Professor Charged in Federal Indictment Yiheng Percival Zhang Charged with Seven Felonies in Relation to Federal Grants RIP to this man. https://www.popsci.com/article/science/qa-engineer-who-wants-power-world-carbs/ https://www.nature.com/articles/ncomms4026

does rem sleep decrease with age?

Studies on the sleep habits of older Americans show an increase in the time it takes to fall asleep (sleep latency), an overall decline in REM sleep, and an increase in sleep fragmentation (waking up during the night) with age.

surface tension role in if something will float

Surface tension and the buoyancy force are both working together to keep the object to keep floating. Surface tension keeps light object from falling into the water; buoyancy pulls up the object.

What is a quantum material?

Technically, every material is a quantum material, because quantum mechanics is required to understand almost every microscopic and aggregate property of a crystalline solid. However, in the condensed matter research community, the term "quantum material" has come to mean something more specific: materials with strong electronic correlations and/or interesting topological properties of the many body electron wavefunction[1][2] . A unifying theme among these often (but not always) disparate pillars of quantum materials is emergence—the idea that aggregate phenomena in a many body system cannot always be explained with a reductionist approach of understanding the individual constituents. The rise of 'quantum materials' as a buzzword in the past decade is illustrated by a series of year-restricted google scholar queries (which pick up both the text of papers and authors' affiliations). Prior to the mid 2000s, the term 'quantum materials' showed up seldom in the research literature, but the yearly frequency rose by more than two orders of magnitude since then. Quantum materials is a broad term in condensed matter physics, to put under the same umbrella, materials that present strong electronic correlations and/or some type of electronic order (superconducting, magnetic order), or materials whose electronic properties are linked to non-generic quantum effects, such as topological insulators, Dirac electron systems such as graphene, as well as systems whose collective properties are governed by genuinely quantum behavior, such as ultra-cold atoms, cold excitons, polaritons, and so forth. A common thread in the study of quantum materials is the concept of emergence.[citation needed].

Does current flow through a capacitor?

Technically, yes. Depends on what you mean by 'current'. Actual charges do NOT flow through a capacitor. That is because there is no conductor between the plates of the capacitor. Even if you consider the negligible conductance of the mica in between, (the resistance of a dielectric isn't infinite, you know) the current conducted is too small to make any difference. What flows are displacement currents, changes in electric field density with time which cause effects similar to currents. These also flow when light passes or radio waves pass. They flow out of an induction heater. They flow out of a lot of places, but usually the value is negligible. In a capacitor, its a lot more. So when a capacitor 'closes' the circuit, its not because the charges flow through it (actual current), but due to the changes of electric field between its plates (displacement current). ______________________ When a capacitor, which is made up of two separate "plate surfaces" physically very close together is in a circuit, and two difference of potential sources, such as a battery; is connected; valence electrons will move as described above. This will create a condition where an abundance of valence electrons will be "collected" on the "less negative / more positive plate of the capacitor until the "collected" potential value matches that of the external battery pole difference and does not increase. That condition is when a capacitor is considered being "charged up". Remember that the difference is measured between the two capacitor plates, where one plate becomes more negative while the other becomes more positive, caused by the depletion of elevated electron-volt valence electrons on it's collective surface, so a "charge" is actually measured between the two capacitor plates and not in relation to any external connection. When a capacitor is discharged, the valence electron movement is through external circuitry only between the capacitor plates — there is no "internal" electron movement or connection. Because the capacitor plates are in actuality, extremely close in commercial capacitors, there is what is called the "Casimir" effect between the two capacitor plates and is outside the question posed here. Again, there is no actual valence electron movement. between the two capacitor plates. and "current" has nothing to do with it; as it is incorrect.

Terby (crater)

Terby is a crater on the northern edge of Hellas Planitia, Mars. It is in the Iapygia quadrangle. The 174 km diameter crater is centered at 28°S, 73°E with an elevation of −5 km. It is named after François J. Terby. It is the site of an ancient lakebed and has clay deposits Evidence for lake on mars

Antarctic Impulsive Transient Antenna (ANITA)

The Antarctic Impulsive Transient Antenna (ANITA) experiment has been designed to study ultra-high-energy (UHE) cosmic neutrinos by detecting the radio pulses emitted by their interactions with the Antarctic ice sheet. This is to be accomplished using an array of radio antennas suspended from a helium balloon flying at a height of about 37,000 meters.[1] The neutrinos, with energies on the order of 1018 eV, produce radio pulses in the ice because of the Askaryan effect. It is thought that these high-energy cosmic neutrinos result from interaction of ultra-high-energy (1020 eV) cosmic rays with the photons of the cosmic microwave background radiation. It is thus hoped that the ANITA experiment can help to explain the origin of these cosmic rays.[2] As of January 2020, ANITA made three flights and detected numerous neutrinos coming from above the experiment, where the radio waves are reflected before they reach ANITA. Two events have signatures indicating that they came from below. These events were unexpected as Earth should absorb most neutrinos of this energy.[6][7] A follow-up study by the IceCube experiment did not find equivalent events.[8]

Askaryan radiation

The Askaryan radiation[1][2] also known as Askaryan effect is the phenomenon whereby a particle traveling faster than the phase velocity of light in a dense dielectric (such as salt, ice or the lunar regolith) produces a shower of secondary charged particles which contain a charge anisotropy and thus emits a cone of coherent radiation in the radio or microwave part of the electromagnetic spectrum. It is similar to the Cherenkov radiation. It is named after Gurgen Askaryan, a Soviet-Armenian physicist who postulated it in 1962. The radiation was first observed experimentally in 2000, 38 years after its theoretical prediction. So far the effect has been observed in silica sand,[3] rock salt,[4] ice,[5] and Earth's atmosphere. The effect is of primary interest in using bulk matter to detect ultra-high energy neutrinos. The Antarctic Impulse Transient Antenna (ANITA) experiment uses antennas attached to a balloon flying over Antarctica to detect the Askaryan radiation produced as cosmic neutrinos travel through the ice.[7][8] Several experiments have also used the Moon as a neutrino detector based on detection of the Askaryan radiation.[9][10][11][12]

How does a particle accelerator work?

The Cockcroft-Walton pre-accelerator provides the first stage of acceleration. Inside this device, hydrogen gas is ionized to create negative ions, each consisting of two electrons and one proton. The ions are accelerated by a positive voltage and reach an energy of 750,000 electron volts (750 keV). This is about 30 times the energy of the electron beam in a television's picture tube. Next, the negative hydrogen ions enter a linear accelerator, approximately 500 feet long. Oscillating electric fields accelerate the negative hydrogen ions to 400 million electron volts (400 MeV). Before entering the third stage, the ions pass through a carbon foil, which removes the electrons, leaving only the positively charged protons. The third stage, the Booster, is located about 20 feet below ground. The Booster is a circular accelerator that uses magnets to bend the beam of protons in a circular path. The protons travel around the Booster about 20,000 times so that they repeatedly experience electric fields. With each revolution the protons pick up more energy, leaving the Booster with 8 billion electron volts (8 GeV). The Main Injector, completed in 1999, accelerates particles and transfers beams. It has four functions: (1) It accelerates protons from 8 GeV to 150 GeV. (2) It produces 120 GeV protons, which are used for antiproton production (see picture and text at bottom). (3) It receives antiprotons from the Antiproton Source and increases their energy to 150 GeV. (4) It injects protons and antiprotons into the Tevatron. Inside the Main Injector tunnel, physicists have also installed an Antiproton Recycler (green ring). It stores antiprotons that return from a trip through the Tevatron, waiting to be re-injected. The Tevatron receives 150 GeV protons and antiprotons from the Main Injector and accelerates them to almost 1000 GeV, or one tera electron volt (1 TeV). Traveling only 200 miles per hour slower than the speed of light, the protons and antiprotons circle the Tevatron in opposite directions. The beams cross each other at the centers of the 5000-ton CDF and DZero detectors located inside the Tevatron tunnel, creating bursts of new particles. To produce antiprotons, the Main Injector sends 120 GeV protons to the Antiproton Source, where the protons collide with a nickel target. The collisions produce a wide range of secondary particles including many antiprotons. The antiprotons are collected, focused and then stored in the Accumulator ring. When a sufficient number of antiprotons has been produced, they are sent to the Main Injector for acceleration and injection into the Tevatron.

IceCube Neutrino Observatory

The IceCube Neutrino Observatory (or simply IceCube) is a neutrino observatory constructed at the Amundsen-Scott South Pole Station in Antarctica.[1]The project is a recognized CERN experiment (RE10).[2][3] Its thousands of sensors are located under the Antarctic ice, distributed over a cubic kilometre. Similar to its predecessor, the Antarctic Muon And Neutrino Detector Array (AMANDA), IceCube consists of spherical optical sensors called Digital Optical Modules (DOMs), each with a photomultiplier tube (PMT)[4] and a single-board data acquisition computer which sends digital data to the counting house on the surface above the array.[5] IceCube was completed on 18 December 2010.[6] DOMs are deployed on strings of 60 modules each at depths between 1,450 and 2,450 meters into holes melted in the ice using a hot water drill. IceCube is designed to look for point sources of neutrinos in the TeV range to explore the highest-energy astrophysical processes. In November 2013 it was announced that IceCube had detected 28 neutrinos that likely originated outside the Solar System.[7] IceCube is part of a series of projects developed and supervised by the University of Wisconsin-Madison. Collaboration and funding are provided by numerous other universities and research institutions worldwide.[8] Construction of IceCube was only possible during the Antarctic austral summer from November to February, when permanent sunlight allows for 24-hour drilling. Construction began in 2005, when the first IceCube string was deployed and sufficient data was collected to verify that the optical sensors functioned correctly.[9] In the 2005-2006 season, an additional eight strings were deployed, making IceCube the largest neutrino telescope in the world.

sigma baryons

The Sigma baryons are a family of subatomic hadron particles which have two quarks from the first flavour generation (up and/or down quarks), and a third quark from higher flavour generations, in a combination where the wavefunction does not swap sign when any two quark flavours are swapped. They are thus baryons, with total Isospin of 1, and can either be neutral or have an elementary charge of +2, +1, 0, or −1. They are closely related to the Lambda baryons, which differ only in the wavefunction's behaviour upon flavour exchange.

Tevatron

The Tevatron was a circular particle accelerator (active until 2011) in the United States, at FermiLab The main achievement of the Tevatron was the discovery in 1995 of the top quark—the last fundamental fermion predicted by the standard model of particle physics. On July 2, 2012, scientists of the CDF and DØ collider experiment teams at Fermilab announced the findings from the analysis of around 500 trillion collisions produced from the Tevatron collider since 2001, and found that the existence of the suspected Higgs boson was highly likely with only a 1-in-550 chance that the signs were due to a statistical fluctuation. The findings were confirmed two days later as being correct with a likelihood of error less than 1 in a million by data from the LHC experiments.[3]

Xi baryon

The Xi baryons or cascade particles are a family of subatomic hadron particles which have the symbol Ξ and may have an electric charge (Q) of +2 e, +1 e, 0, or −1 e, where e is the elementary charge. Like all conventional baryons, they contain three quarks. Xi baryons, in particular, contain one up or down quark plus two more massive quarks: either strange, charm or bottom. They are historically called the cascade particles because of their unstable state; they decay rapidly into lighter particles through a chain of decays.[1] The first discovery of a charged Xi baryon was in cosmic ray experiments by the Manchester group in 1952.

Neural tube

a groove formed in the top layer of differentiated cells in the embryo that eventually becomes the brain and spinal cord In the developing chordate (including vertebrates), the neural tube is the embryonic precursor to the central nervous system, which is made up of the brain and spinal cord. The neural groove gradually deepens as the neural folds become elevated, and ultimately the folds meet and coalesce in the middle line and convert the groove into the closed neural tube. In humans, neural tube closure usually occurs by the fourth week of pregnancy (28th day after conception). The ectodermal wall of the tube forms the rudiment of the nervous system. The centre of the tube is the neural canal.

Atomic radius

The atomic radius of a chemical element is a measure of the size of its atoms, usually the mean or typical distance from the center of the nucleus to the boundary of the surrounding shells of electrons. Since the boundary is not a well-defined physical entity, there are various non-equivalent definitions of atomic radius. Three widely used definitions of atomic radius are: Van der Waals radius, ionic radius, and covalent radius.

Is anybody else perplexed by the reaction to coronavirus compared to the reaction to climate change?

The big difference is that in the case of the coronavirus we are the victims, and in the case of the climate we are the virus.

Escape velocity on mars

The escape velocity of Mars is 4.25 km. s. The escape velocity of Earth is 11.19 km/s On the surface of the Earth, the escape velocity is about 11.2 km/s, which is approximately 33 times the speed of sound (Mach 33) and several times the muzzle velocity of a rifle bullet (up to 1.7 km/s). However, at 9,000 km altitude in "space", it is slightly less than 7.1 km/s.

what are match tips made of?

The head of safety matches are made of an oxidizing agent such as potassium chlorate, mixed with sulfur, fillers and glass powder. The side of the box contains red phosphorus, binder and powdered glass.

identity crisis

a period of uncertainty and confusion in which a person's sense of identity becomes insecure, typically due to a change in their expected aims or role in society.

what is the iris made of?

The iris is made of connective tissue, smooth muscle fibers, and pigments that give the iris its color. The pigments in the iris are made of melanin (the same pigment that gives skin its color) and lipochrome. The amount of pigment in the eye creates eye color.

machine learning vs deep learning

The key difference between deep learning vs machine learning stems from the way data is presented to the system. Machine learning algorithms almost always require structured data, whereas deep learning networks rely on layers of the ANN (artificial neural networks).

The Map is not the Territory

The map of reality is not reality. Even the best maps are imperfect. That's because they are reductions of what they represent. If a map were to represent the territory with perfect fidelity, it would no longer be a reduction and thus would no longer be useful to us. A map can also be a snapshot of a point in time, representing something that no longer exists. This is important to keep in mind as we think through problems and make better decisions.

most contagious disease

The most contagious disease on Earth is Rotavirus, followed by Malaria and Measles. As has been explained by others, the measure of contagiousness is the average reproduction number = average number of people an infected person is likely to infect. This is different from deadliness which is measured by mortality rates = how many of those infected will likely die. On that measure, untreated rabies, untreated HIV and Ebola are the three deadliest diseases.

Principal-agent problem

The principal-agent problem, in political science and economics occurs when one person or entity, is able to make decisions and/or take actions on behalf of, or that impact, another person or entity: the "principal. The really short version is that people act according to their own incentives, so if you hire someone to act on your behalf, you'd better make sure that their incentives align with yours. If you don't, they might want to work towards an outcome that's not the best possible for you. The classic case is an auto mechanic who recommends an expensive procedure. You don't know whether they're making that recommendation because it's the best thing for your car, or because it generates a lot of money for them. The usual method of addressing the principal-agent problem is to write up a contract that aligns the incentives of both parties. Sometimes that's not too bad to do. Sometimes it's very difficult.

Zeppelin

large gas-filled balloon (used by Germany to bomb England) A Zeppelin is a type of rigid airship named after the German Count Ferdinand von Zeppelin who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874 and developed in detail in 1893. How do they work? The same way boats do. Buoyancy. Zeppelins have a metal or composite frame that holds their shape - in contrast to blimps, which have no rigid structure, using gas pressure to maintain their shape. Inside the rigid frame, there are bags filled with a lifting gas - usually hydrogen or helium. These two gasses are less dense than air. The concept of buoyancy functions thusly: You have a container that displaces a volume of fluid. If the stuff in that container is heavier than the equivalent volume worth of whatever it is displacing, it will sink. If it is lighter, it will float. In a boat, the container is the boat itself. It is filled with air and cargo, and it is displacing water. On Earth, water weighs 1000kg/m^3, so if your boat has a volume of 1m^3, if it weighs 1000.1kg, it will sink. Take out one bag of rice, and it will float again. In a zeppelin, the container is the gas bag, and it is displacing air. At sea level on Earth, air weighs 1.225kg/m^3, so if your zeppelin has gas bags of volume 1000m^3, the zeppelin should weigh 1225kg. If it is lighter than that, it will float up, if it is heavier than that, it will sink. Air density reduces with altitude above sea-level, so if you make your zeppelin lighter or increase the volume of the gas bags, it will float upwards until it reaches some hight where the density of air and the weight of the zeppelin reaches some equilibrium and it is 'neutrally buoyant'. Zeppelins used to use hydrogen has a lifting gas. This was great because it is extremely cheap. The downside is that it is also extremely explosive. Modern zeppelins use helium, which is very expensive, but does not explode under any circumstances. The problem with this, is that gas expands as you increase in altitude, due to the dropping outside air pressure. Zeppelins filled with hydrogen can just let out some gas to stop the gas bags bursting. This would be way to expensive to do with helium, so zeppelins filled with helium have to start with gas bags that aren't completely full. As the helium expands, it fills the bag. This means that even though the net lift of helium and hydrogen is nearly the same, the payload capacity of a hydrogen-filled zeppelin is significantly more than the same airship filled with helium - almost twice in some cases. Once the airship pilot has balanced weight and buoyancy, the airship is neutrally buoyant - it doesn't sink nor float. Then she flies the aircraft forward, and uses the movable fins on the back to direct it up or down, left and right.

echopraxia

mimicking the movements of another meaningless repetition or imitation of the movements of others as a symptom of psychiatric disorder.

hydroxyl radicals

most reactive of the toxic forms of oxygen The hydroxyl radical, •OH, is the neutral form of the hydroxide ion (OH−). Hydroxyl radicals are highly reactive (easily becoming hydroxyl groups) and consequently short-lived; however, they form an important part of radical chemistry.[2] Most notably hydroxyl radicals are produced from the decomposition of hydroperoxides (ROOH) or, in atmospheric chemistry, by the reaction of excited atomic oxygen with water. It is also an important radical formed in radiation chemistry, since it leads to the formation of hydrogen peroxide and oxygen, which can enhance corrosion and SCC in coolant systems subjected to radioactive environments. Hydroxyl radicals are also produced during UV-light dissociation of H2O2 (suggested in 1879) and likely in Fenton chemistry, where trace amounts of reduced transition metals catalyze peroxide-mediated oxidations of organic compounds. The hydroxyl radical is often referred to as the "detergent" of the troposphere because it reacts with many pollutants, decomposing them through "cracking", often acting as the first step to their removal. It also has an important role in eliminating some greenhouse gases like methane and ozone.[3] The rate of reaction with the hydroxyl radical often determines how long many pollutants last in the atmosphere, if they do not undergo photolysis or are rained out. For instance methane, which reacts relatively slowly with hydroxyl radical, has an average lifetime of >5 years and many CFCs have lifetimes of 50 years or more. Other pollutants, such as larger hydrocarbons, can have very short average lifetimes of less than a few hours.

crying over spilt milk

o express regret about something that has already happened or cannot be changed: Yes, we made a mistake, but there's no point in crying over spilled milk

What P.S means in a letter?

post scriptum If you are talking about P.S. when used in writing, it stands for postscript, from the Latin post scriptum, meaning "written after." It is generally used in letter-writing to indicate something added after the body of the letter was completed and signed.

Photolithography

process of making micro-processing chips Photolithography, also called optical lithography or UV lithography, is a process used in microfabrication to pattern parts on a thin film or the bulk of a substrate (also called a wafer). It uses light to transfer a geometric pattern from a photomask (also called an optical mask) to a photosensitive (that is, light-sensitive) chemical photoresist on the substrate. A series of chemical treatments then either etches the exposure pattern into the material or enables deposition of a new material in the desired pattern upon the material underneath the photoresist. In complex integrated circuits, a CMOS wafer may go through the photolithographic cycle as many as 50 times. Photolithography shares some fundamental principles with photography in that the pattern in the photoresist etching is created by exposing it to light, either directly (without using a mask) or with a projected image using a photomask. This procedure is comparable to a high precision version of the method used to make printed circuit boards. Subsequent stages in the process have more in common with etching than with lithographic printing. This method can create extremely small patterns, down to a few tens of nanometers in size. It provides precise control of the shape and size of the objects it creates and can create patterns over an entire surface cost-effectively. Its main disadvantages are that it requires a flat substrate to start with, it is not very effective at creating shapes that are not flat, and it can require extremely clean operating conditions. Photolithography is the standard method of printed circuit board (PCB) and microprocessor fabrication. Directed self-assembly is being evaluated as an alternative to photolithography.[1]

ependymal cells

produce and circulate cerebrospinal fluid The ependyma is the thin neuroepithelial lining of the ventricular system of the brain and the central canal of the spinal cord.[1] The ependyma is one of the four types of neuroglia in the central nervous system (CNS). It is involved in the production of cerebrospinal fluid (CSF), and is shown to serve as a reservoir for neuroregeneration. The ependyma is made up of ependymal cells called ependymocytes, a type of glial cell. These cells line the CSF-filled ventricles in the brain and the central canal of the spinal cord. These are nervous tissue cells with a ciliated simple columnar[2] shape, much like that of some mucosal epithelial cells. The basal membranes of these cells are characterized by tentacle-like extensions that attach to astrocytes.

alpine

relating to high mountains. "alpine and subalpine habitats"

stereo-

relating to solid forms having three dimensions.

pulmonary

relating to the lungs. Pulmonary hypertension: A type of high blood pressure that affects arteries in the lungs and in the heart.

omega baryons

represented by the symbol Ω and are either neutral or have a +2, +1 or −1 elementary charge. They are baryons containing no up or down quarks. Omega baryons containing top quarks are not expected to be observed. This is because the Standard Model predicts the mean lifetime of top quarks to be roughly 5×10−25 s,[2] which is about a twentieth of the timescale for strong interactions, and therefore that they do not form hadrons.

Bayesian reasoning

systematically combining information regarding new evidence with prior beliefs to determine the probability of a hypothesis Bayesian inference is a method of statistical inference in which Bayes' theorem is used to update the probability for a hypothesis as more evidence or information becomes available. Bayesian inference is an important technique in statistics, and especially in mathematical statistics

venera 13

the name of the Soviet space craft that landed on Venus and was able to send back to earth two photographs of Venus' surface Venera 13 and 14 were identical spacecraft built to take advantage of the 1981 Venus launch opportunity and launched 5 days apart, Venera 13 on 30 October 1981 at 06:04 UTC and Venera 14 on 4 November 1981 at 05:31 UTC, both with an on-orbit dry mass of 760 kg (1,680 lb).

lithography

the process of printing from a flat surface treated so as to repel the ink except where it is required for printing. an analogous method for making printed circuits.

Momentum

the product of the mass of an object and its velocity kg * m/s

Xenobiology

the study of non-terrestrial life Xenobiology is a subfield of synthetic biology, the study of synthesizing and manipulating biological devices and systems. The name "xenobiology" derives from the Greek word xenos, which means "stranger, alien". Xenobiology is a form of biology that is not familiar to science and is not found in nature.

Treaty of Versailles

the treaty imposed on Germany by the Allied powers in 1920 after the end of World War I which demanded exorbitant reparations from the Germans

disbarred

to take away an attorney's license to practice law because of illegal or unethical conduct expel (a lawyer) from the Bar, so that they no longer have the right to practice law.