TECHNICAL QUESTIONS - Topics for diploma examination for degree of Batchelor of Science Engineer for Engineering Management

History of paper

- invented in China 2000 yrs ago (105 year) (Ts'ai dun) - used hemp, mulberry bark, and old cloth with mater and water mushed into a pulp and let it dry to make paper - wood used now to make it

History of steam engines

1712 - Thomas Newcomen 1763 - James Watt - improvements Parts of a steam engine: - a fire where coal burns - a boiler full of water that fire heats up to make steam - a cylinder and piston - steam from the boiler is piped into the cylinder, causing the piston to move first one way and then the other (reciprocating) - a machine attached to a piston (water pump, factory machine, locomotive etc)

History of electric engines (electric motors)

1834 - Thomas Davenport of Vermont Electrical energy to mechanical energy. Interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied the motor's shaft.

History of combustion engines

1872 - George Brayton - first liquid fueled internal combustion engine. High temperature combustion process + spark plug + fuel and air mixture + exhaust => transmission => output power

History of hunting tools

2.6 million years ago - sharpened stones 1.6 million years ago - stone handaxe 80 000 - 40 000 years ago - cutting blades 11 000 - 17 000 years ago - sharp microblades 12 000 years ago - axes, celts, chisels

history of clocks

Ancient times - sundials Candle clocks Water clocks Mechanical water clocks XIIIth Century Europe - fully mechanical clock 1815 - electric clock

Efficiency of processes and machines

Definition of machinery efficiency - It is the percent of work put into a machine by the user (input work) that becomes work done by the machine (output work). It is a measure of how well a machine reduces friction. How to measure the efficiency of friction: to calculate the efficiency of the process we need to divide the total process time by the overall cycle time (process time + waiting time)

History of fire making

Early middle Paleolithic (old Stone Age) 300 000 to 30 000 years ago

History of the reactor

Enrico Fermi - nuclear reactor - 1942 World's first nuclear chain reaction - Chicago Pile - 1 Controlled, self - sustained, nuclear reaction using fissile material.

Metalworking - its essence, technologies, tools, products, effects on the environment and on humans

Essence - a process of shaping and reshaping metals to create useful objects. As a term it covers a wide and diverse range of processes, skills and tools for producing objects. Technologies: - casting (lost wax casting, centrifugal casting, die casting, sand casting, shell casting, spin casting) - forming processess (cold sicing, extrusion, drawing, forging, powder metallurgy, friction drilling, rolling, burnishing) - cutting processes (drilling, machining, turning, milling, grinding) - joining processes (welding, braining, soldering, riveting) - sheet and tube forming (stamping, shearing etc) Tools: - general use machine tools, safety equipment, furnace, klin, torch, saw, chisel, shear, snips, water jet, angle grinder, air compressor, electirc grinder Products: - household appliences, construction equipment, electrical components, farming equipment, defense weapons, tools and equipment, transportation and machining tools, pneumatic angle grinder, welding helmet Effects: - recyclable but air and noi^ %UTY7

Abrasive machining - essence, technologies, tools, products, effect on environment and on humans

Essence - abrasive machining is a machining process where material is removed from a workpiece using a multitude of small abrasive particles. Works by forcing the abrasive particles or grains into the surface of a workpiece, so that each particle cuts away small bits of material. Technologies: -> fixed (bonded) abrasive processes: - grinding - polishing - tape fishing - sanding -> loose abrasive processes: - polishing - lapping - AFM (abrasive flow machining) - hydro - erosive grinding - water - jet cutting Tools: - abrasive particles, abrasive jet machine, diamond abrasive based cutting tool for processing Product: - tooling (machine parts)

Erosive machining - essence, technologies, tools, products, effect on environment and on humans

Essence - erosive machining (electrical discharge machining) EDM - metal fabrication process - a desired shape is obtained by using electrical discharges (sparks). Material is removed from the workpiece by a series of rapidly recurring current discharges between two electrodes, separated by a dialectric liquid and subject to alectric voltage (there is a tool electrode and workpiece electrode). The process depends on those two electrodes not making physical contact). Technologies: - die -sink EDM - wire -sink EDM Tools: - tool electrode, workpiece electrode, EDM control panel, diaelectric liquid Products: turbine blade, tooling (f.e. with small holes) Effects - waste, high energy consuption

Machining - essence, technologies, tools, products, effect on environment and on humans

Essence - machining is a process, in which a material (often metal, can be wood, plastic, ceramic, composite material) is cut to a desired final shape and size by a controlled material - removal process. Material removal = subtractive manufacturing Technology: - turning (remove material from rotating workpiece into a cylindrical shape) - drilling (round hole) - boring (enlarging a hole and improvement of its accurracy) - reaming (removing material from the already drilled hole) - milling (plane or straight surface) -> in modern machining - CNC machines (computer numerical control) are used to control the movement and operation of the mills, lathes and other cutting machines Tools: mills, lathes, cutting machines, CNSs Products: parts of components for f.e. automotive, energy, medical, security, communication, military and safety industries Effect: high energy consumption - air pollution, carbon footprint, creating waste, coolants and oils (lubricants) - dangerous for humans and for the environment Many shops receycle waste, few recycle machines

Metal casting - essence, technologies, tools, products, effect on environment and on humans

Essence - metal casting is a 7 000 years old process used in manufacturing. Molten metal is transferred from a crucidible into a mold to create a positive metal cast object. The metal and mold are cooled, and the metal object is removed and finished. Technologies: - lost wax casting - plaster mold casting - die casting - sand casting (there are reusable molds and expendable molds). Tools: - a mold, a crucidible, tongs, a furnace, torch or klin, safety equipment and well - ventilated workspace Products: - tools, weapons, jouelery, religious objects, household appliences, construction equipment, electrical components, farming equipment, trasnportation, machining tools Effects: worse air quality, noise pollution no hazarsous waste, recyclable

History of computer

First computer - Babbage Difference Engine by Charles Babbage - 1822

Phenomenon of friction in technology

Friction is an important topic when it comes to technology, especially machines that have moving parts. Mankind's attempts to control friction move back to the invention of the wheel. Fundamentals of surface contact, use of various lubricants, and specific applications such as brakes, piston rings, and machine components are all part of the phenomenon of friction. Friction drilling of metals •Friction of tires and road surfaces Frictional behavior of a wide range of materials, coatings, and surface treatments, both traditional and advanced, such as thermally oxidized titanium alloys, nanocomposites, ultra-low friction films, laser-dimpled ceramics, and carbon composites. Even after centuries of study, friction continues to conceal its subtle origins, especially in practical engineering situations in which surfaces are exposed to complex and changing environments.

History of the wheel

IVth Century bc - lower Mesopotamia, Summarian people, inserted rotating axels into solid discs of wood

Machines in aid of intellectual processes in humans

Intelligent machines try to imitate how the human brain is organized and functions but they can process a lot more data and so they can help aid intellectual processes of humans. -> MACHINE LEARNING the field of study that gives computers the capability to learn without being explicitly programmed. It has applications across business problems and to make predictions. -> ANN (Artificial Naural Networks) form the base of deep learing, which is a subset of machine learning, where algorithms are inspierd by the human brain. ANN take in the data by input layer, train themselves to recognize patterns using hidden layer and then predict the output for a new set of similar data in the output layer. -> GA (genetic algorithms) is a search technique used in computers to find true or approximate solutions to optimization and search problems.

Thermal and thermo-chemical treatment (essence, technologies, tools, products, effect on the environment and on humans)

Material engineering processes that are intended to give materials specific properties through material transfer with environment. This primarly takes place in the surface layers during heat treatment. The substitute materials can be introduced in the form of solids (powders, pasters), loquids (molten metals) or gasses (air, nitrogen). Technologies - carburizing, boronising, carbonitriding, nnitriding, oxidizing, sulphidising, chromizing, altising, siliconizing, magnising. Products - enhanced metals, bearings, Tools : salt baths, gas generating, annealing machines, hardening machine, carburizing machines Machining has serious impact on both humans and environment. Machining causes release of gases as well as machined particles which when inhaled may appear hazardous. Modern companies often introduce health aware systems which are meant to lower the risk of pollution. When heavy metals are released to environment they stay in the ground and waters surrounding for long time as they do not decompose naturally. (to samo w 10,11,12)

Non - permanent fastening in mechanical engineering

Non-permanent fasteners are designed to allow for easy removal and re-use. Parts can be assembled and re-assembled if necessary. Non-permanent fasteners: - THREADED - bolts - screws - studs - NON-THREADED - pins - retaining rings

Permanent fastening in mechanical engineering

Permanent fastening - fasteners will not come apart without breaking - provide immovable solution. Examples: - RIVETS before bing installed, a rivet consists of a smooth cylindrical shaft with a head on one end and tail on the other - WELDING a fabrication process that joins materials, usually metals or thermoplastics togehter by using heat to melt parts together and allowing them to cool to cause fusion - SOLDERING joining two types of metals together by melting solder - a metal alloy (tin and lea melted using iron) heated abobe 600 degrees fahrenheit, when cools there is strong electrical bond - BRAZING two or more metal items are joined together by melting and flowing a filler metal into a joint, with the filler metal having lower melting point then adjoining material (differs from welding as it does not involve melting the work pieces).

History of stone tool making

Prehistory - stone age (4000 to 2000 bce) Africa, examples: arrow heads, spear heads, hand axes, querns

Principle of energy conservation

Principle of conservation of energy states that energy is neither created nor destroyed. It may transform from one type to another. It is an empirical law. The common forms of energy include: - thermal - electrical - chemical - mechanical - kinetic - potential. The sum of all kinds of energy is constant. Sum(E(k)) = constant E - energy k - different types of energy Many engineering applications include transformation of energy between two or three types of energy only: - dynamics problems - kinetic and potential (in some cases frictional work) - chemical reactions - conservation of energy includes thermal and chemical energies - (most) thermodynamics problems - applied to nonreactive systems - thermal and mechanical energies (in all cases, other forms of energy are ignored)

Energy accumulation in technology

Some of energy storage technologies: - pumped - storage hydropoer (PSH) (most popular) - compressed air - molten salt (thermal) - Li - ou battery - lead-acid battery - flow battery - hydrogen - flywheel Definition of accumulation of energy: - the storing of energy by various means.

Surface treatment (essence, technologies, tools, products, effect on the environment and on humans)

Surface treatment is performed in order to achieve certain property of material. It may be done to improve appearance, adhesion, wettability, solderability, corrosion resistance, tarnish resistance, chemical resistance, wear resistance, hardness, modify electrical conductivity, remove burrs and control surface friction. It is surface finishing which can be categorized in to 2 types - removing and adding. Methods : Blanching, case hardening, electroplating, conversion coating, grinding, sandblasting. Tools: Case hardening can be performed with fire and chemical solutions, grinder, sandblaster, grinding stone Machining has serious impact on both humans and environment. Machining causes release of gases as well as machined particles which when inhaled may appear hazardous. Modern companies often introduce health aware systems which are meant to lower the risk of pollution. When heavy metals are released to environment they stay in the ground and waters surrounding for long time as they do not decompose naturally. (to samo w 10,11,12)

Normalization and system of compliance assessment in technology

System of compliance assessment: - local laws - rules and regulations - standards - internal policies - ethical practices Standards - ISO - International Organization for Standardization - developed and published international standards The standardization is necessary because this process is considered the building block for d developing a product under the defined rules and protocols that are followed universally and adopted by everyone. Normalization is the process of reorganizing data in a database so that it meets two basic requirements: There is no redundancy of data, all data is stored in only one place. Data dependencies are logical,all related data items are stored together. Also, maybe they are asking about the bolts, shafts, screws atc that have to be in normalized or standardiezed sizes so that they are available and easily used by everyone.

General principles of calculating strength of materials at various loads

The main purpose of calculating the strength of a material is to determine its strength and stiffness. This field of study focuses on calculating stresses and strain in structural members such as beams, columns and shafts. There are various models used to asses properties of material such as yield strength, ultimate strength, young's modulus and poisson's ratio. Yield point - point which indicates limit of elastic behavior and beginning of plastic behavior (below this point material will return to previous shape) Ultimate Strength - maximum stress which can be applied to the material Youngs modulus - mechanical property that measures the tensile or compressive stiffness of solid material Poisons ratio - deformation of material in directions perpendicular to specific direction of loading. Following factors are important in assessing the strength of material: 1. Force applied 2. Elasticity modulus 3. Area of material 4. Strain

Use and construction of clutches and breaks in machines

Use - clutches and breaks are used to adjust the speed of rotating elements. A clucth connencts an in-line or parallel shafts to either start or adjust the speed of the load. A break is used to slow, stop or hold the load static by transferring energy to the machine framr or motor flange. Construction: - CLUTCH Discontinues the flow of power to the transmission There is a female cone, a male cone, shaft, friction material, spring, clutch control and rotation in a particular direction. - BREAK There are: wheel bearing, wheel studs, caliper assembly, disc pads, disc/motor in a DISC BREAK.