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Grease Pencil
The grease pencil, a wax writing tool also known as a wax pencil, china marker, or chinagraph pencil (especially in the United Kingdom), is a writing implement made of hardened colored wax and is useful for marking on hard, glossy non-porous surfaces. This pencil is usually made from non-toxic opaque wax (such as paraffin, beeswax, ceresin, carnauba or spermaceti wax) that is similar to a crayon but stronger. Marks made by grease pencils are resistant to moisture and can usually be removed by rubbing the marked surface with a paper towel. Grease pencils are available in several forms. The outer casing may be made of wood (like an ordinary pencil) and sharpened with a knife or pencil sharpener. Other types are covered in paper and sharpened by pulling a string to peel off the paper, needing no additional tools to remain functional. More recently, it has been produced in propelling form, essentially similar to a mechanical pencil, this type in particular being associated with kne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grease Pencil
The grease pencil, a wax writing tool also known as a wax pencil, china marker, or chinagraph pencil (especially in the United Kingdom), is a writing implement made of hardened colored wax and is useful for marking on hard, glossy non-porous surfaces. This pencil is usually made from non-toxic opaque wax (such as paraffin, beeswax, ceresin, carnauba or spermaceti wax) that is similar to a crayon but stronger. Marks made by grease pencils are resistant to moisture and can usually be removed by rubbing the marked surface with a paper towel. Grease pencils are available in several forms. The outer casing may be made of wood (like an ordinary pencil) and sharpened with a knife or pencil sharpener. Other types are covered in paper and sharpened by pulling a string to peel off the paper, needing no additional tools to remain functional. More recently, it has been produced in propelling form, essentially similar to a mechanical pencil, this type in particular being associated with kne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rock (geology)
In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's outer solid layer, the crust, and most of its interior, except for the liquid outer core and pockets of magma in the asthenosphere. The study of rocks involves multiple subdisciplines of geology, including petrology and mineralogy. It may be limited to rocks found on Earth, or it may include planetary geology that studies the rocks of other celestial objects. Rocks are usually grouped into three main groups: igneous rocks, sedimentary rocks and metamorphic rocks. Igneous rocks are formed when magma cools in the Earth's crust, or lava cools on the ground surface or the seabed. Sedimentary rocks are formed by diagenesis and lithification of sediments, which in turn are formed by the weathering, transport, and deposition of existing ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. Radio waves (pulsed or continuous) from the transmitter reflect off the objects and return to the receiver, giving information about the objects' locations and speeds. Radar was developed secretly for military use by several countries in the period before and during World War II. A key development was the cavity magnetron in the United Kingdom, which allowed the creation of relatively small systems with sub-meter resolution. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aircraft Control
A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight. Aircraft engine controls are also considered as flight controls as they change speed. The fundamentals of aircraft controls are explained in flight dynamics. This article centers on the operating mechanisms of the flight controls. The basic system in use on aircraft first appeared in a readily recognizable form as early as April 1908, on Louis Blériot's Blériot VIII pioneer-era monoplane design. Cockpit controls Primary controls Generally, the primary cockpit flight controls are arranged as follows:Langewiesche, WolfgangStick and Rudder: An Explanation of the Art of Flying McGraw-Hill Professional, 1990, , . * a control yoke (also known as a control column), centre stick or side-stick (the latter two also colloquially known as a control or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Color Gel
Color (American English) or colour (British English) is the visual perceptual property deriving from the spectrum of light interacting with the photoreceptor cells of the eyes. Color categories and physical specifications of color are associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra. By defining a color space, colors can be identified numerically by their coordinates. Because perception of color stems from the varying spectral sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantified by the degree to which they stimulate these cells. These physical or physiological quantifications of color, however, do not fully explain the psychophysical perception of color appearance. Color science includes the perception of color by the eye and brain, the origin of color in materials, color theory in art, and the physics of electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
