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Destructive Testing
In destructive testing (or destructive physical analysis, DPA) tests are carried out to the specimen's failure, in order to understand a specimen's performance or material behavior under different loads. These tests are generally much easier to carry out, yield more information, and are easier to interpret than nondestructive testing. Destructive testing is most suitable, and economic, for objects which will be mass-produced, as the cost of destroying a small number of specimens is negligible. It is usually not economical to do destructive testing where only one or very few items are to be produced (for example, in the case of a building). Analyzing and documenting the destructive failure mode is often accomplished using a high-speed camera recording continuously (movie-loop) until the failure is detected. Detecting the failure can be accomplished using a sound detector or stress gauge which produces a signal to trigger the high-speed camera. These high-speed cameras have advanced r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nondestructive Testing
Nondestructive testing (NDT) is any of a wide group of analysis techniques used in science and technology industry to evaluate the properties of a material, component or system without causing damage. The terms nondestructive examination (NDE), nondestructive inspection (NDI), and nondestructive evaluation (NDE) are also commonly used to describe this technology. Because NDT does not permanently alter the article being inspected, it is a highly valuable technique that can save both money and time in product evaluation, troubleshooting, and research. The six most frequently used NDT methods are eddy-current, magnetic-particle, liquid penetrant, radiographic, ultrasonic, and visual testing. NDT is commonly used in forensic engineering, mechanical engineering, petroleum engineering, electrical engineering, civil engineering, systems engineering, aeronautical engineering, medicine, and art. Innovations in the field of nondestructive testing have had a profound impact on medica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2012 Boeing 727 Crash Experiment
On April 27, 2012, a multinational team of television studios staged an airplane crash near Mexicali, Mexico. An unmanned Boeing 727-200, fitted with numerous cameras, crash test dummies and other scientific instruments, was flown into the ground. The exercise was filmed for television. Aircraft and test site The aircraft used was a Boeing 727-200 purchased by the television production companies, registration ''XB-MNP'' (formerly N293AS). The site in Mexico was chosen because authorities in the United States would not allow the test to take place. The aircraft's original owner was Singapore Airlines. The last United-States-based owner was Broken Wing LLC of Webster Groves, Missouri, who then exported it and transferred it to a Mexican production company. Broken Wing is also the company that planned and executed the experiment. The aircraft had been leased to Bob Dole's 1996 presidential election campaign by the then-owner AvAtlantic. Flight Several federal permits by the Mexic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Testability
Testability is a primary aspect of Science and the Scientific Method and is a property applying to an empirical hypothesis, involves two components: #Falsifiability or defeasibility, which means that counterexamples to the hypothesis are logically possible. #The practical feasibility of observing a reproducible series of such counterexamples if they do exist. In short, a hypothesis is testable if there is a possibility of deciding whether it is true or false based on experimentation by anyone. This allows anyone to decide whether a theory can be supported or refuted by data. However, the interpretation of experimental data may be also inconclusive or uncertain. Karl Popper introduced the concept that scientific knowledge had the property of Falsifiability.as published in ''The Logic of Scientific Discovery.Karl Popper "The Logic of Scientific Discovery", 1934 (as Logik der Forschung, English translation 1959)'', ISBN 0415278449 and 2002 ISBN 9780415278447, 0415278449 See also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress Test (other)
Stress test may refer to: *Cardiac stress test, testing of the heart (a.k.a. "treadmill test") *Stress testing of software, hardware, or nuclear plants ** Stress test (hardware) ** Stress testing (software) * Stress test (financial) * ''Stress Test'' (book), a book by former United States Secretary of the Treasury Timothy Geithner *"Stress Test", a 1990 episode of ''The Raccoons'' * Stress analysis, methods for computing mechanical stress * Contraction stress test, relating to labor and delivery * Trier social stress test, a procedure used to induce stress in human research participants * Voice stress analysis, sometimes called a voice stress test See also *Highly accelerated life test, generally for electronic equipment * Fatigue (material) *Stress (mechanics) In continuum mechanics, stress is a physical quantity. It is a quantity that describes the magnitude of forces that cause deformation. Stress is defined as ''force per unit area''. When an object is pulled apart by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Show And Display
The "Show or Display" rule is a statutory amendment to the United States Federal Motor Vehicle Safety Standards (FMVSS) that allows certain privately imported automobiles to be exempted, if the vehicle in question is deemed to meet a standard of "historical or technological significance". The amendment, which became law on August 13, 1999, is intended to apply to vehicles that could not feasibly be brought into compliance with the FMVSS, including requirements for destructive testing and that do not have a similar make or model certified for sale in the United States market. Applications are managed by the National Highway Traffic Safety Administration, and may allow limited use on public roads ( annually). Because of the expense and effort required to import a vehicle with this exemption, the approved vehicle list is mainly limited to high-value sports and touring cars. Background The United States is not signatory to the United Nations World Forum for Harmonization of Vehicle Reg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproducibility
Reproducibility, also known as replicability and repeatability, is a major principle underpinning the scientific method. For the findings of a study to be reproducible means that results obtained by an experiment or an observational study or in a statistical analysis of a data set should be achieved again with a high degree of reliability when the study is replicated. There are different kinds of replication but typically replication studies involve different researchers using the same methodology. Only after one or several such successful replications should a result be recognized as scientific knowledge. With a narrower scope, ''reproducibility'' has been introduced in computational sciences: Any results should be documented by making all data and code available in such a way that the computations can be executed again with identical results. In recent decades, there has been a rising concern that many published scientific results fail the test of reproducibility, evoking a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nondestructive Testing
Nondestructive testing (NDT) is any of a wide group of analysis techniques used in science and technology industry to evaluate the properties of a material, component or system without causing damage. The terms nondestructive examination (NDE), nondestructive inspection (NDI), and nondestructive evaluation (NDE) are also commonly used to describe this technology. Because NDT does not permanently alter the article being inspected, it is a highly valuable technique that can save both money and time in product evaluation, troubleshooting, and research. The six most frequently used NDT methods are eddy-current, magnetic-particle, liquid penetrant, radiographic, ultrasonic, and visual testing. NDT is commonly used in forensic engineering, mechanical engineering, petroleum engineering, electrical engineering, civil engineering, systems engineering, aeronautical engineering, medicine, and art. Innovations in the field of nondestructive testing have had a profound impact on medica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallographic Test
Metallography is the study of the physical structure and components of metals, by using microscopy. Ceramic and polymeric materials may also be prepared using metallographic techniques, hence the terms ceramography, plastography and, collectively, materialography. Preparing metallographic specimens The surface of a metallographic specimen is prepared by various methods of grinding, polishing, and etching. After preparation, it is often analyzed using optical or electron microscopy. Using only metallographic techniques, a skilled technician can identify alloys and predict material properties. Mechanical preparation is the most common preparation method. Successively finer abrasive particles are used to remove material from the sample surface until the desired surface quality is achieved. Many different machines are available for doing this grinding and polishing, which are able to meet different demands for quality, capacity, and reproducibility. A systematic preparat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Median Lethal Dose
In toxicology, the median lethal dose, LD50 (abbreviation for " lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a toxin, radiation, or pathogen. The value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. LD50 figures are frequently used as a general indicator of a substance's acute toxicity. A lower LD50 is indicative of increased toxicity. The test was created by J.W. Trevan in 1927. The term semilethal dose is occasionally used in the same sense, in particular with translations of foreign language text, but can also refer to a sublethal dose. LD50 is usually determined by tests on animals such as laboratory mice. In 2011, the U.S. Food and Drug Administration approved alternative methods to LD50 for testing the cosmetic drug Botox without animal tests. Conventions The LD50 is usually expressed as the mass of substance administered pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardness
In materials science, hardness (antonym: softness) is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. In general, different materials differ in their hardness; for example hard metals such as titanium and beryllium are harder than soft metals such as sodium and metallic tin, or wood and common plastics. Macroscopic hardness is generally characterized by strong intermolecular bonds, but the behavior of solid materials under force is complex; therefore, hardness can be measured in different ways, such as scratch hardness, indentation hardness, and rebound hardness. Hardness is dependent on ductility, elastic stiffness, plasticity, strain, strength, toughness, viscoelasticity, and viscosity. Common examples of hard matter are ceramics, concrete, certain metals, and superhard materials, which can be contrasted with soft matter. Measuring hardness There are three main types of hardness measurements: ''s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crash Test
A crash test is a form of destructive testing usually performed in order to ensure safe design standards in crashworthiness and crash compatibility for various modes of transportation (see automobile safety) or related systems and components. Types * Frontal-impact tests: which is what most people initially think of when asked about a crash test. Vehicles usually impact a solid concrete wall at a specified speed, but these can also be vehicle impacting vehicle tests. SUVs have been singled out in these tests for a while, due to the high ride-height that they often have. * Moderate Overlap tests: in which only part of the front of the car impacts with a barrier (vehicle). These are important, as impact forces (approximately) remain the same as with a frontal impact test, but a smaller fraction of the car is required to absorb all of the force. These tests are often realized by cars turning into oncoming traffic. This type of testing is done by the U.S.A. Insurance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marlene Dietrich
Marie Magdalene "Marlene" DietrichBorn as Maria Magdalena, not Marie Magdalene, according to Dietrich's biography by her daughter, Maria Riva ; however Dietrich's biography by Charlotte Chandler cites "Marie Magdalene" as her birth name . (, ; 27 December 1901 – 6 May 1992) was a German and American actress and singer whose career spanned from the 1910s to the 1980s. In 1920s Berlin, Dietrich performed on the stage and in silent films. Her performance as Lola-Lola in Josef von Sternberg's ''The Blue Angel'' (1930) brought her international acclaim and a contract with Paramount Pictures. She starred in many Hollywood films, including six iconic roles directed by Sternberg: ''Morocco'' (1930) (her only Academy Award nomination), ''Dishonored'' (1931), '' Shanghai Express'' and ''Blonde Venus'' (both 1932), ''The Scarlet Empress'' (1934) and '' The Devil Is a Woman'' (1935), '' Desire'' (1936) and ''Destry Rides Again'' (1939). She successfully traded on her glamorous persona ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
