|
Engine Break-in
Break-in or breaking in, also known as run-in or running in, is the procedure of conditioning a new piece of equipment by giving it an initial period of running, usually under light load, but sometimes under heavy load or normal load. It is generally a process of moving parts wearing against each other to produce the last small bit of size and shape adjustment that will settle them into a stable relationship for the rest of their working life. One of the most common examples of break-in is engine break-in for petrol engines and diesel engines. Engine break-in A new engine is broken in by following specific driving guidelines during the first few hours of its use. The focus of breaking in an engine is on the contact between the piston rings of the engine and the cylinder wall. There is no universal preparation or set of instructions for breaking in an engine. Most importantly, experts disagree on whether it is better to start engines on high or low power to break them in. While ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petrol Engine
A petrol engine (gasoline engine in American English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as liquefied petroleum gas and ethanol blends (such as ''E10'' and ''E85''). Most petrol engines use spark ignition, unlike diesel engines which typically use compression ignition. Another key difference to diesel engines is that petrol engines typically have a lower compression ratio. Design Thermodynamic cycle Most petrol engines use either the four-stroke Otto cycle or the two-stroke cycle. Petrol engines have also been produced using the Miller cycle and Atkinson cycle. Layout Most petrol-powered piston engines are straight engines or V engines. However, flat engines, W engines and other layouts are sometimes used. Wankel engines are classified by the number of rotors used. Compression ratio Cooling Petrol engines are either air-cooled or water-cooled. Ignition Petrol e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit Cost
The unit cost is the price incurred by a company to produce, store and sell one unit of a particular product. Unit costs include all fixed costs and all variable costs Variable costs are costs that change as the quantity of the good or service that a business produces changes.Garrison, Noreen, Brewer. Ch 2 - Managerial Accounting and Costs Concepts, pp 48 Variable costs are the sum of marginal costs over all u ... involved in production. Cost unit is a form of measurement of volume of production or service. Cost unit vs unit cost Cost unit is the standard unit for buying the minimum of any product. Unit cost is the minimum cost for buying any standard unit. References {{Business-term-stub Costs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shoe
A shoe is an item of footwear intended to protect and comfort the human foot. They are often worn with a sock. Shoes are also used as an item of decoration and fashion. The design of shoes has varied enormously through time and from culture to culture, with form originally being tied to function. Though the human foot can adapt to varied terrains and climate conditions, it is still vulnerable to environmental hazards such as sharp rocks and temperature extremes, which shoes protect against. Some shoes are worn as safety equipment, such as steel-toe boots which are required footwear at industrial worksites. Additionally, fashion has often dictated many design elements, such as whether shoes have very high heels or flat ones. Contemporary footwear varies widely in style, complexity and cost. Basic sandals may consist of only a thin sole and simple strap and be sold for a low cost. High fashion shoes made by famous designers may be made of expensive materials, use complex constr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burn-in
Burn-in is the process by which components of a system are exercised before being placed in service (and often, before the system being completely assembled from those components). This testing process will force certain failures to occur under supervised conditions so an understanding of load capacity of the product can be established. The intention is to detect those particular components that would fail as a result of the initial, high-failure rate portion of the bathtub curve of component reliability. If the burn-in period is made sufficiently long (and, perhaps, artificially stressful), the system can then be trusted to be mostly free of further early failures once the burn-in process is complete. Theoretically, any weak components would fail during the "Burn In" time allowing those parts to be replaced. Replacing the weak components would prevent premature failure, infant mortality failure, or other latent defects. When the equivalent lifetime of the stress is extended i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Confirmation Bias
Confirmation bias is the tendency to search for, interpret, favor, and recall information in a way that confirms or supports one's prior beliefs or values. People display this bias when they select information that supports their views, ignoring contrary information, or when they interpret ambiguous evidence as supporting their existing attitudes. The effect is strongest for desired outcomes, for emotionally charged issues, and for deeply entrenched beliefs. Confirmation bias cannot be eliminated, but it can be managed, for example, by education and training in critical thinking skills. Biased search for information, biased interpretation of this information, and biased memory recall, have been invoked to explain four specific effects: # ''attitude polarization'' (when a disagreement becomes more extreme even though the different parties are exposed to the same evidence) # ''belief perseverance'' (when beliefs persist after the evidence for them is shown to be false) # the ''irr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anecdotal Evidence
Anecdotal evidence is evidence based only on personal observation, collected in a casual or non-systematic manner. The term is sometimes used in a legal context to describe certain kinds of testimony which are uncorroborated by objective, independent evidence such as notarized documentation, photographs, audio-visual recordings, etc. When used in advertising or promotion of a product, service, or idea, anecdotal reports are often called a testimonial, which are highly regulated in some jurisdictions. When compared to other types of evidence, anecdotal evidence is generally regarded as limited in value due to a number of potential weaknesses, but may be considered within the scope of scientific method as some anecdotal evidence can be both empirical and verifiable, e.g. in the use of case studies in medicine. Other anecdotal evidence, however, does not qualify as scientific evidence, because its nature prevents it from being investigated by the scientific method. Where only one or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Applied Science
Applied science is the use of the scientific method and knowledge obtained via conclusions from the method to attain practical goals. It includes a broad range of disciplines such as engineering and medicine. Applied science is often contrasted with basic science, which is focused on advancing scientific theories and laws that explain and predict events in the natural world. Applied science can also apply formal science, such as statistics and probability theory, as in epidemiology. Genetic epidemiology is an applied science applying both biological and statistical methods. Applied research Applied research is the practical application of science. It accesses and uses accumulated theories, knowledge, methods, and techniques, for a specific state-, business-, or client-driven purpose. Applied Research can be better understood in any area when contrasting it with, basic, or pure, research. Basic geography research strives to create new theories and methods that aid in the expl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regulatory Compliance
In general, compliance means conforming to a rule, such as a specification, policy, standard or law. Compliance has traditionally been explained by reference to the deterrence theory, according to which punishing a behavior will decrease the violations both by the wrongdoer (specific deterrence) and by others (general deterrence). This view has been supported by economic theory, which has framed punishment in terms of costs and has explained compliance in terms of a cost-benefit equilibrium (Becker 1968). However, psychological research on motivation provides an alternative view: granting rewards (Deci, Koestner and Ryan, 1999) or imposing fines (Gneezy Rustichini 2000) for a certain behavior is a form of extrinsic motivation that weakens intrinsic motivation and ultimately undermines compliance. Regulatory compliance describes the goal that organizations aspire to achieve in their efforts to ensure that they are aware of and take steps to comply with relevant laws, policies, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compliance (medicine)
In medicine, patient compliance (also adherence, capacitance) describes the degree to which a patient correctly follows medical advice. Most commonly, it refers to medication or drug compliance, but it can also apply to other situations such as medical device use, self care, self-directed exercises, or therapy sessions. Both patient and health-care provider affect compliance, and a positive physician-patient relationship is the most important factor in improving compliance. Access to care plays a role in patient adherence, whereby greater wait times to access care contributing to greater absenteeism. The cost of prescription medication also plays a major role. Compliance can be confused with concordance, which is the process by which a patient and clinician make decisions together about treatment. Worldwide, non-compliance is a major obstacle to the effective delivery of health care. 2003 estimates from the World Health Organization indicated that only about 50% of patients with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accuracy And Precision
Accuracy and precision are two measures of ''observational error''. ''Accuracy'' is how close a given set of measurements ( observations or readings) are to their ''true value'', while ''precision'' is how close the measurements are to each other. In other words, ''precision'' is a description of '' random errors'', a measure of statistical variability. ''Accuracy'' has two definitions: # More commonly, it is a description of only '' systematic errors'', a measure of statistical bias of a given measure of central tendency; low accuracy causes a difference between a result and a true value; ISO calls this ''trueness''. # Alternatively, ISO defines accuracy as describing a combination of both types of observational error (random and systematic), so high accuracy requires both high precision and high trueness. In the first, more common definition of "accuracy" above, the concept is independent of "precision", so a particular set of data can be said to be accurate, precise, both, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diesel Engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-called compression-ignition engine (CI engine). This contrasts with engines using spark plug-ignition of the air-fuel mixture, such as a petrol engine (gasoline engine) or a gas engine (using a gaseous fuel like natural gas or liquefied petroleum gas). Diesel engines work by compressing only air, or air plus residual combustion gases from the exhaust (known as exhaust gas recirculation (EGR)). Air is inducted into the chamber during the intake stroke, and compressed during the compression stroke. This increases the air temperature inside the cylinder to such a high degree that atomised diesel fuel injected into the combustion chamber ignites. With the fuel being injected into the air just before combustion, the dispersion of the fuel is une ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Finish
Surface finish, also known as surface texture or surface topography, is the nature of a surface as defined by the three characteristics of lay, surface roughness, and waviness.. It comprises the small, local deviations of a surface from the perfectly flat ideal (a true plane). Surface texture is one of the important factors that control friction and transfer layer formation during sliding. Considerable efforts have been made to study the influence of surface texture on friction and wear during sliding conditions. Surface textures can be isotropic or anisotropic. Sometimes, stick-slip friction phenomena can be observed during sliding, depending on surface texture. Each manufacturing process (such as the many kinds of machining) produces a surface texture. The process is usually optimized to ensure that the resulting texture is usable. If necessary, an additional process will be added to modify the initial texture. The latter process may be grinding (abrasive cutting), polishing, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
