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Acceptance Angle (solar Concentrator)
Acceptance angle is the maximum angle at which incoming sunlight can be captured by a solar concentrator. Its value depends on the concentration of the optic and the refractive index in which the receiver is immersed. Maximizing the acceptance angle of a concentrator is desirable in practical systems and it may be achieved by using nonimaging optics. For concentrators that concentrate light in two dimensions, the acceptance angle may be different in the two directions. Definition The "acceptance angle" figure illustrates this concept. The concentrator is a lens (optics), lens with a receiver ''R''. The left section of the figure shows a set of parallel Ray (optics), rays incident on the concentrator at an angle ''α'' ''θ'' to the optical axis. All rays now miss the receiver and all light is lost. Therefore, for incidence angles ''α'' ''θ'' all light is lost. The concentrator is then said to have a (half) acceptance angle ''θ'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunlight
Sunlight is the portion of the electromagnetic radiation which is emitted by the Sun (i.e. solar radiation) and received by the Earth, in particular the visible spectrum, visible light perceptible to the human eye as well as invisible infrared (typically perceived by humans as warmth) and ultraviolet (which can have physiological effects such as sunburn) lights. However, according to the American Meteorological Society, there are "conflicting conventions as to whether all three [...] are referred to as light, or whether that term should only be applied to the visible portion of the spectrum." Upon reaching the Earth, sunlight is light scattering by particles, scattered and attenuation, filtered through the atmosphere of Earth, Earth's atmosphere as daylight when the Sun is above the horizon. When direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat (atmospheric). When cloud cover, blocked by clouds or dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresnel Lens
A Fresnel lens ( ; ; or ) is a type of composite compact lens (optics), lens which reduces the amount of material required compared to a conventional lens by dividing the lens into a set of concentric annular sections. The simpler Dioptrics, dioptric (purely refraction, refractive) form of the lens was first proposed by Georges-Louis Leclerc, Comte de Buffon, and independently reinvented by the French physicist Augustin-Jean Fresnel (1788–1827) for use in lighthouses. The Catadioptric system, catadioptric (combining refraction and reflection) form of the lens, entirely invented by Fresnel, has outer Prism (optics), prismatic elements that use total internal reflection as well as refraction to capture more oblique light from the light source and add it to the beam, making it visible at greater distances. The design allows the construction of lenses of large aperture and short focal length without the mass and volume of material that would be required by a lens of conventional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guided Ray
A guided ray (also bound ray or trapped ray) is a ray of light in a multi-mode optical fiber, which is confined by the core. For step index fiber, light entering the fiber will be guided if it falls within the acceptance cone of the fiber, that is if it makes an angle with the fiber axis that is less than the acceptance angle, :\theta < \arcsin \left( \sqrt \right) , where :''θ'' is the angle the ray makes with the fiber axis, ''before'' entering the fiber, :''n''0 is the along the central axis (core) of the fiber, and :''n''c is the refractive index of the cladding. The quantity is the of the fiber. The quantity |
Etendue
Etendue or étendue (; ) is a property of light in an optical system, which characterizes how "spread out" the light is in area and angle. It corresponds to the beam parameter product (BPP) in Gaussian beam optics. Other names for etendue include acceptance, throughput, light grasp, light-gathering power, optical extent, and the AΩ product. ''Throughput'' and ''AΩ product'' are especially used in radiometry and radiative transfer where it is related to the view factor (or shape factor). It is a central concept in nonimaging optics. From the source point of view, etendue is the product of the area of the source and the solid angle that the system's entrance pupil subtends as seen from the source. Equivalently, from the system point of view, the etendue equals the area of the entrance pupil times the solid angle the source subtends as seen from the pupil. These definitions must be applied for infinitesimally small "elements" of area and solid angle, which must then b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRC Press
The CRC Press, LLC is an American publishing group that specializes in producing technical books. Many of their books relate to engineering, science and mathematics. Their scope also includes books on business, forensics and information technology. CRC Press is now a division of Taylor & Francis, itself a subsidiary of Informa. History The CRC Press was founded as the Chemical Rubber Company (CRC) in 1903 by brothers Arthur, Leo and Emanuel Friedman in Cleveland, Ohio, based on an earlier enterprise by Arthur, who had begun selling rubber laboratory aprons in 1900. The company gradually expanded to include sales of laboratory equipment to chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...s. In 1913 the CRC offered a short (116-page) manual called the ''Rubber Handboo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium (optics)
In optics, an optical medium is material through which light and other electromagnetic waves propagate. It is a form of transmission medium. The permittivity and permeability of the medium define how electromagnetic waves propagate in it. Properties The optical medium has an '' intrinsic impedance'', given by ::\eta = where E_x and H_y are the electric field and magnetic field, respectively. In a region with no electrical conductivity, the expression simplifies to: ::\eta = \sqrt\ . For example, in free space the intrinsic impedance is called the characteristic impedance of vacuum, denoted ''Z''0, and ::Z_0 = \sqrt\ . Waves propagate through a medium with velocity c_w = \nu \lambda , where \nu is the frequency and \lambda is the wavelength of the electromagnetic waves. This equation also may be put in the form : c_w = \ , where \omega is the angular frequency of the wave and k is the wavenumber of the wave. In electrical engineering, the symbol \beta, called the '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acceptance Angle-Angular Aperture Of Sunlight
Acceptance in psychology is a person's recognition and assent to the finality of a situation without attempting to change or protest it. This plays out at both the individual and societal level as people experience change. Types of acceptance The term ''acceptance'' is a noun with various meanings. Self-acceptance Self-acceptance is described as the state of being satisfied with one's current self, or the ongoing process of striving to be satisfied with one's current self. It is an agreement with oneself to appreciate, validate, and support the self as it is, despite deficiencies and negative past behavior. Some have trouble accepting themselves because of guilt, trauma, or a perceived lack of motivation. Self-acceptance has an effect on a person mentally, emotionally, within relationships and overall life. Psychological acceptance Acceptance is a core element of acceptance and commitment therapy (ACT) and cognitive behavioral therapy (CBT). In this context, accep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Aberration
In optics, aberration is a property of optical systems, such as Lens (optics), lenses and mirrors, that causes the ''image'' created by the optical system to not be a faithful reproduction of the ''object'' being observed. Aberrations cause the image formed by a lens to be blurred, distorted in shape or have color fringing or other effects not seen in the object, with the nature of the distortion depending on the type of aberration. Aberration can be defined as a departure of the performance of an optical system from the predictions of paraxial optics. In an imaging system, it occurs when light from one point of an object does not converge into (or does not diverge from) a single point after transmission through the system. Aberrations occur because the simple paraxial theory is not a completely accurate model of the effect of an optical system on light, rather than due to flaws in the optical elements. An image-forming optical system with aberration will produce an image which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acceptance Angle-Optical Imperfections
Acceptance in psychology is a person's recognition and assent to the finality of a situation without attempting to change or protest it. This plays out at both the individual and societal level as people experience change. Types of acceptance The term ''acceptance'' is a noun with various meanings. Self-acceptance Self-acceptance is described as the state of being satisfied with one's current self, or the ongoing process of striving to be satisfied with one's current self. It is an agreement with oneself to appreciate, validate, and support the self as it is, despite deficiencies and negative past behavior. Some have trouble accepting themselves because of guilt, trauma, or a perceived lack of motivation. Self-acceptance has an effect on a person mentally, emotionally, within relationships and overall life. Psychological acceptance Acceptance is a core element of acceptance and commitment therapy (ACT) and cognitive behavioral therapy (CBT). In this context, accep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Tracking
A solar tracker is a device that orients a payload toward the Sun. Payloads are usually solar panels, parabolic troughs, Fresnel reflectors, lenses, or the mirrors of a heliostat. For flat-panel photovoltaic systems, trackers are used to minimize the angle of incidence between the incoming sunlight and a photovoltaic panel, sometimes known as the cosine error. Reducing this angle increases the amount of energy produced from a fixed amount of installed power-generating capacity. In standard photovoltaic applications, it was predicted in 2008–2009 that trackers could be used in at least 85% of commercial installations greater than one megawatt from 2009 to 2012. As the pricing, reliability, and performance of single-axis trackers have improved, the systems have been installed in an increasing percentage of utility-scale projects. According to data from WoodMackenzie/GTM Research, global solar tracker shipments hit a record 14.5 gigawatts in 2017. This represents growth of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parabolic Trough
A parabolic trough collector (PTC) is a type of solar thermal collector that is straight in one dimension and curved as a parabola in the other two, lined with a polished metal mirror. The sunlight which enters the mirror parallel to its plane of symmetry is focused along the focal line, where objects are positioned that are intended to be heated. In a solar cooker, for example, food is placed at the focal line of a trough, which is cooked when the trough is aimed so the Sun is in its plane of symmetry. For other purposes, a tube containing a fluid runs the length of the trough at its focal line. The sunlight is concentrated on the tube and the fluid heated to a high temperature by the energy of the sunlight. The hot fluid can be piped to a heat engine (e.g. ORC or water/steam Rankine cycle), which uses the heat energy to drive machinery, or to generate electricity. This solar energy collector is the most common and best known type of parabolic trough. When heat transfer fluid i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Concentrator
Concentrated solar power (CSP, also known as concentrating solar power, concentrated solar thermal) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight into a receiver. Electricity is generated when the concentrated light is converted to heat (solar thermal energy), which drives a heat engine (usually a steam turbine) connected to an electrical power generator or powers a thermochemical reaction. As of 2021, global installed capacity of concentrated solar power stood at 6.8 GW. As of 2023, the total was 8.1 GW, with the inclusion of three new CSP projects in construction in China and in Dubai in the UAE. The U.S.-based National Renewable Energy Laboratory (NREL), which maintains a global database of CSP plants, counts 6.6 GW of operational capacity and another 1.5 GW under construction. Comparison between CSP and other electricity sources As a thermal energy generating power station, CSP has more in common with thermal power sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
