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Diffraction
Diffraction
Diffraction
refers to various phenomena that occur when a wave encounters an obstacle or a slit. It is defined as the bending of light around the corners of an obstacle or aperture into the region of geometrical shadow of the obstacle. In classical physics, the diffraction phenomenon is described as the interference of waves according to the Huygens–Fresnel principle. These characteristic behaviors are exhibited when a wave encounters an obstacle or a slit that is comparable in size to its wavelength. Similar effects occur when a light wave travels through a medium with a varying refractive index, or when a sound wave travels through a medium with varying acoustic impedance
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Steam
Steam
Steam
is water in the gas phase, which is formed when water boils. Steam
Steam
is invisible; however, "steam" often refers to wet steam, the visible mist or aerosol of water droplets formed as this water vapour condenses. At lower pressures, such as in the upper atmosphere or at the top of high mountains, water boils at a lower temperature than the nominal 100 °C (212 °F) at standard pressure. If heated further it becomes superheated steam. The enthalpy of vaporization is the energy required to turn water into the gaseous form when it increases in volume by 1,700 times at standard temperature and pressure; this change in volume can be converted into mechanical work by steam engines such as reciprocating piston type engines and steam turbines, which are a sub-group of steam engines
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Sound Wave
In physics, sound is a vibration that typically propagates as an audible wave of pressure, through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain.[1] Humans can only hear sound waves as distinct pitches when the frequency lies between about 20 Hz and 20 kHz. Sound
Sound
above 20 kHz is ultrasound and is not perceptible by humans. Sound
Sound
waves below 20 Hz are known as infrasound
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Jetty
A jetty is a structure that projects from the land out into water. Often, "jetty" refers to a walkway accessing the centre of an enclosed waterbody. The term is derived from the French word jetée, "thrown", and signifies something thrown out.[1]Contents1 For regulating rivers 2 For berthing at docks 3 At entrances to jetty harbors 4 At lagoon outlets 5 Rivers5.1 At the outlet of tideless rivers 5.2 At the mouth of tidal rivers6 See also 7 Notes 8 ReferencesFor regulating rivers[edit] Another form of jetties, wing dams are extended out, opposite one another, from each bank of a river, at intervals, to contract a wide channel, and by concentration of the current to produce a deepening.[2] For berthing at docks[edit] Where docks are given sloping sides, openwork timber jetties are generally carried across the slope, at the ends of which vessels can lie in deep water or more solid structures are erected over the slope for supporting coal-tips
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Hot Spring
A hot spring is a spring produced by the emergence of geothermally heated groundwater that rises from the Earth's crust. While some of these springs contain water that is a safe temperature for bathing, others are so hot that immersion can result in injury or death.Contents1 Definitions 2 Sources of heat 3 Flow rates3.1 High flow hot springs4 Therapeutic uses 5 Biota in hot springs 6 Notable hot springs 7 Etiquette 8 See also 9 References 10 Further reading 11 External linksDefinitions[edit]"Blood Pond" hot spring in Beppu, JapanThere is no universally accepted definition of a hot spring
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Aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are, which is of great importance for the appearance at the image plane.[2] If an aperture is narrow, then highly collimated rays are admitted, resulting in a sharp focus at the image plane. A wide aperture admits uncollimated rays, resulting in a sharp focus only for rays coming from a certain distance. This means that a wide aperture results in an image that is sharp for things at the correct distance. The aperture also determines how many of the incoming rays are actually admitted and thus how much light reaches the image plane (the narrower the aperture, the darker the image for a given exposure time)
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Glory (optical Phenomenon)
A glory is an optical phenomenon that resembles an iconic saint's halo about the shadow of the observer's head, caused by light of the Sun or (more rarely) the Moon interacting with the tiny water droplets that make up mist or clouds. The glory consists of one or more concentric, successively dimmer rings, each of which is red on the outside and bluish towards the centre
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Ultrasonic Transducer
Ultrasonic transducers are divided into three broad categories: transmitters, receivers and transceivers. Transmitters convert electrical signals into ultrasound, receivers convert ultrasound into electrical signals, and transceivers can both transmit and receive ultrasound. In a similar way to radar and sonar, ultrasonic transducers are used in systems which evaluate targets by interpreting the reflected signals
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Radar Antenna
Radar
Radar
engineering details are technical details pertaining to the components of a radar and their ability to detect the return energy from moving scatterers — determining an object's position or obstruction in the environment.[1][2][3] This includes field of view in terms of solid angle and maximum unambiguous range and velocity, as well as angular, range and velocity resolution
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Thomas Young (scientist)
Thomas Young (13 June 1773 – 10 May 1829) was an English polymath and physician. Young made notable scientific contributions to the fields of vision, light, solid mechanics, energy, physiology, language, musical harmony, and Egyptology. He "made a number of original and insightful innovations"[1] in the decipherment of Egyptian hieroglyphs
Egyptian hieroglyphs
(specifically the Rosetta Stone) before Jean-François Champollion
Jean-François Champollion
eventually expanded on his work. He was mentioned by, among others, William Herschel, Hermann von Helmholtz, James Clerk Maxwell, and Albert Einstein
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Quantum Mechanics
Quantum mechanics (QM; also known as quantum physics or quantum theory), including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles.[2] Classical physics
Classical physics
(the physics existing before quantum mechanics) is a set of fundamental theories which describes nature at ordinary (macroscopic) scale
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Wind Wave
In fluid dynamics, wind waves, or wind-generated waves, are surface waves that occur on the free surface of bodies of water (like oceans, seas, lakes, rivers, canals, puddles or ponds). They result from the wind blowing over an area of fluid surface. Waves in the oceans can travel thousands of miles before reaching land. Wind
Wind
waves on Earth range in size from small ripples, to waves over 100 ft (30 m) high.[1] When directly generated and affected by local winds, a wind wave system is called a wind sea. After the wind ceases to blow, wind waves are called swells. More generally, a swell consists of wind-generated waves that are not significantly affected by the local wind at that time
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Deli Meat
Lunch meats—also known as cold cuts, luncheon meats, cooked meats, sliced meats, cold meats and deli meats—are precooked or cured meat, often sausages or meat loaves, that are sliced and served cold or hot on sandwiches or on party trays.[1] They can be bought pre-sliced in vacuum packs at a supermarket or grocery store, or they can be purchased at a delicatessen or deli counter, where they might be sliced to order
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Acoustic Impedance
Acoustic impedance and specific acoustic impedance are measures of the opposition that a system presents to the acoustic flow resulting of an acoustic pressure applied to the system. The SI unit of acoustic impedance is the pascal second per cubic metre (Pa·s/m3) or the rayl per square metre (rayl/m2), while that of specific acoustic impedance is the pascal second per metre (Pa·s/m) or the rayl.[1] In this article the symbol rayl denotes the MKS rayl
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Wave Equation
The wave equation is an important second-order linear partial differential equation for the description of waves—as they occur in classical physics—such as sound waves, light waves and water waves. It arises in fields like acoustics, electromagnetics, and fluid dynamics. Historically, the problem of a vibrating string such as that of a musical instrument was studied by Jean le Rond d'Alembert, Leonhard Euler, Daniel Bernoulli, and Joseph-Louis Lagrange.[1][2][3][4] In 1746, d’Alembert discovered the one-dimensional wave equation, and within ten years Euler discovered the three-dimensional wave equation.[5]Contents1 Introduction 2 Scalar wave equation in one space dimension2.1 Derivation of the wave equation2.1.1 From Hooke's law 2.1.2 Stress pulse in a bar2.2 General solution2.2.1 Algebraic approach 2.2.2
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Umbra, Penumbra And Antumbra
The umbra, penumbra and antumbra are three distinct parts of a shadow, created by any light source after impinging on an opaque object. For a point source only the umbra is cast. These names are most often used for the shadows cast by celestial bodies, though they are sometimes used to describe levels of darkness, such as in sunspots.Contents1 Umbra 2 Penumbra 3 Antumbra 4 See also 5 ReferencesUmbra[edit]Umbra, penumbra, and antumbra formed through windows and shuttersThe umbra (Latin for "shadow") is the innermost and darkest part of a shadow, where the light source is completely blocked by the occluding body. An observer in the umbra experiences a total eclipse. The umbra of a round body occluding a round light source forms a right circular cone; to a viewer at the cone's apex, the two bodies are equal in apparent size
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