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Advanced Composite Materials (engineering)
In materials science, advanced composite materials (ACMs) are materials that are generally characterized by unusually high strength fibres with unusually high stiffness, or modulus of elasticity characteristics, compared to other materials, while bound together by weaker matrices. These are termed "advanced composite materials" in comparison to the composite materials commonly in use such as reinforced concrete, or even concrete itself. The high strength fibers are also low density while occupying a large fraction of the volume. Advanced composites exhibit desirable physical and chemical properties that include light weight coupled with high stiffness ( elasticity), and strength along the direction of the reinforcing fiber, dimensional stability, temperature and chemical resistance, flex performance, and relatively easy processing. Advanced composites are replacing metal components in many uses, particularly in the aerospace industry. Composites are classified according to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
States Of Matter
In physics, a state of matter is one of the distinct forms in which matter can exist. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma. Many intermediate states are known to exist, such as liquid crystal, and some states only exist under extreme conditions, such as Bose–Einstein condensates (in extreme cold), neutron-degenerate matter (in extreme density), and quark–gluon plasma (at extremely high energy). For a complete list of all exotic states of matter, see the list of states of matter. Historically, the distinction is made based on qualitative differences in properties. Matter in the solid state maintains a fixed volume (assuming no change in temperature or air pressure) and shape, with component particles (atoms, molecules or ions) close together and fixed into place. Matter in the liquid state maintains a fixed volume (assuming no change in temperature or air pressure), but has a variable shape that adapts to fit its container ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undergraduate Education
Undergraduate education is education conducted after secondary education and before postgraduate education. It typically includes all postsecondary programs up to the level of a bachelor's degree. For example, in the United States, an entry-level university student is known as an ''undergraduate'', while students of higher degrees are known as '' graduate students''. Upon completion of a number of required and elective courses as part of an undergraduate program, the student would earn the corresponding degree. (In some regions, individual "courses" and the "program" collection are given other terms, such as "units" and "course", respectively.) In some other educational systems, undergraduate education is postsecondary education up to the level of a master's degree; this is the case for some science courses in Britain and some medicine courses in Europe. Programs Africa Nigerian system In Nigeria, undergraduate degrees (excluding Medicine, Medical Laboratory Science, Nursing, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comanche Helicopter
The Comanche or Nʉmʉnʉʉ ( com, Nʉmʉnʉʉ, "the people") are a Native American tribe from the Southern Plains of the present-day United States. Comanche people today belong to the federally recognized Comanche Nation, headquartered in Lawton, Oklahoma. The Comanche language is a Numic language of the Uto-Aztecan family. Originally, it was a Shoshoni dialect, but diverged and became a separate language. The Comanche were once part of the Shoshone people of the Great Basin. In the 18th and 19th centuries, Comanche lived in most of present-day northwestern Texas and adjacent areas in eastern New Mexico, southeastern Colorado, southwestern Kansas, and western Oklahoma. Spanish colonists and later Mexicans called their historical territory ''Comanchería''. During the 18th and 19th centuries, Comanche practiced a nomadic horse culture and hunted, particularly bison. They traded with neighboring Native American peoples, and Spanish, French, and American colonists and se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Aviation Administration
The Federal Aviation Administration (FAA) is the largest transportation agency of the U.S. government and regulates all aspects of civil aviation in the country as well as over surrounding international waters. Its powers include air traffic management, certification of personnel and aircraft, setting standards for airports, and protection of U.S. assets during the launch or re-entry of commercial space vehicles. Powers over neighboring international waters were delegated to the FAA by authority of the International Civil Aviation Organization. Created in , the FAA replaced the former Civil Aeronautics Administration (CAA) and later became an agency within the U.S. Department of Transportation. Major functions The FAA's roles include: *Regulating U.S. commercial space transportation *Regulating air navigation facilities' geometric and flight inspection standards *Encouraging and developing civil aeronautics, including new aviation technology *Issuing, suspending, or revoki ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Army Aviation
An army aviation unit is an aviation-related unit of a nation's army, sometimes described as an air corps. These units are generally separate from a nation's dedicated air force, and usually comprise helicopters and light support fixed-wing aircraft. Prior to the establishment of separate national air forces, many armies had military aviation units, which as the importance of aviation increased, were spun off into independent services. As the separation between a nation's army and air force led to a divergence of priorities, many armies sought to re-establish their own aviation branches to best serve their own organic tactical needs. History Military aviation first began as either army or naval aviation units established as force multipliers to allow armies and navies to better do what they were already doing, this taking mostly the form of reconnaissance and artillery spotting, this led to the first fighter aircraft whose purpose was to shoot down enemy reconnaissance and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Advanced Space Transportation Program
The Advanced Space Transportation Program (ASTP) is a NASA program to intentionally advance current space transportation system technologies, and innovate novel technologies, through intense research efforts that are intended to culminate in regularizing the outer space environment decades from now. The intense efforts aim to accelerate scientific and technological breakthroughs. History and funding Routine space travel As NASA's core technology program for all space transportation, the Advanced Space Transportation Program at the Marshall Space Flight Center is advancing technologies that substantially increase the safety, and reliability of space transportation, as well as reduce the cost. Presently, it costs $10,000 to put a pound of payload in Earth orbit. NASA's goal is to reduce the cost of getting to space to hundreds of dollars per pound within 25 years and tens of dollars per pound within 40 years. The high cost of space transportation coupled with unreliability c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sports Equipment
Sports equipment, sporting equipment, also called sporting goods, are the tools, materials, apparel, and gear used to compete in a sport and varies depending on the sport. The equipment ranges from balls, nets, and protective gear like helmets. Sporting equipment can be used as protective gear or a tool used to help the athletes play the sport. Over time, sporting equipment has evolved because sports have started to require more protective gear to prevent injuries. Sporting equipment may be found in any department store or specific sporting equipment shops. History and development of sports Historically many sports players have developed their own sporting equipment over time. For instance, the use of a football dates back to ancient China, between 225 BC and 220 AD. As football remains the most popular sport in the 21st century, the material of the ball has completely changed over the centuries; from being made out of animal skin, to being lined with multiple layers of polyes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines. Common examples of aircraft include airplanes, helicopters, airships (including blimps), gliders, paramotors, and hot air balloons. The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called '' aeronautics.'' Crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion, usage and others. History Flying model craft and stories of manned flight go back many centuries; however, the first manned ascent — and safe descent — in modern times took place by larger h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of an electric charge, which can be either positive or negative, produces an electric field. The movement of electric charges is an electric current and produces a magnetic field. When a charge is placed in a location with a non-zero electric field, a force will act on it. The magnitude of this force is given by Coulomb's law. If the charge moves, the electric field would be doing work on the electric charge. Thus we can speak of electric potential at a certain point in space, which is equal to the work done by an external agent in carrying a unit of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geometry
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is called a ''geometer''. Until the 19th century, geometry was almost exclusively devoted to Euclidean geometry, which includes the notions of point, line, plane, distance, angle, surface, and curve, as fundamental concepts. During the 19th century several discoveries enlarged dramatically the scope of geometry. One of the oldest such discoveries is Carl Friedrich Gauss' ("remarkable theorem") that asserts roughly that the Gaussian curvature of a surface is independent from any specific embedding in a Euclidean space. This implies that surfaces can be studied ''intrinsically'', that is, as stand-alone spaces, and has been expanded into the theory of manifolds and Riemannian geometry. Later in the 19th century, it appeared that geome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitude
Longitude (, ) is a geographic coordinate that specifies the east– west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Meridians are semicircular lines running from pole to pole that connect points with the same longitude. The prime meridian defines 0° longitude; by convention the International Reference Meridian for the Earth passes near the Royal Observatory in Greenwich, England on the island of Great Britain. Positive longitudes are east of the prime meridian, and negative ones are west. Because of the Earth's rotation, there is a close connection between longitude and time measurement. Scientifically precise local time varies with longitude: a difference of 15° longitude corresponds to a one-hour difference in local time, due to the differing position in relation to the Sun. Comparing local time to an absolute measure of time a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
