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Radiative Transfer Equation and Diffusion Theory for Photon Transport in Biological Tissue
The RTE can mathematically model the transfer of energy as photons move inside a tissue. The flow of radiation energy through a small area element in the radiation field can be characterized by radiance [math]\displaystyle{ L(\vec{r},\hat{s},t) (\frac{W}{m^2 sr}) }[/math]. Radiance is defined as energy flow per unit normal area per unit solid angle per unit time. Here, [math]\displaystyle{ \vec{r} }[/math] denotes position, [math]\displaystyle{ \hat{s} }[/math] denotes unit direction vector and [math]\displaystyle{ t }[/math] denotes time. 
  • 2.7K
  • 16 Nov 2022
Topic Review
Homogeneity
In physics, a homogeneous material or system has the same properties at every point; it is uniform without irregularities. A uniform electric field (which has the same strength and the same direction at each point) would be compatible with homogeneity (all points experience the same physics). A material constructed with different constituents can be described as effectively homogeneous in the electromagnetic materials domain, when interacting with a directed radiation field (light, microwave frequencies, etc.). Mathematically, homogeneity has the connotation of invariance, as all components of the equation have the same degree of value whether or not each of these components are scaled to different values, for example, by multiplication or addition. Cumulative distribution fits this description. "The state of having identical cumulative distribution function or values".
  • 3.0K
  • 15 Nov 2022
Topic Review
Socialist Party USA
The Socialist Party USA, officially the Socialist Party of the United States of America (SPUSA), is a multi-tendency democratic socialist party in the United States . The SPUSA was founded in 1973 as a successor to the Socialist Party of America, which had been renamed Social Democrats, USA a year before. The party is officially committed to multi-tendency democratic socialism. Along with its predecessor, the Socialist Party USA has received varying degrees of support when its candidates have competed against those from the Republican and Democratic parties. The SPUSA advocates for complete independence from the Democratic Party. Self-described as opposing all forms of oppression, specifically capitalism and authoritarian forms of communism, the party advocates for the creation of a "radical democracy that places people's lives under their own control—a non-racist, classless, feminist, socialist society [... in which] the people own and control the means of production and distribution through democratically-controlled public agencies, cooperatives, or other collective groups [...] full employment is realized for everyone who wants to work [...] workers have the right to form unions freely, and to strike and engage in other forms of job actions [...] production of society is used for the benefit of all humanity, not for the private profit of a few". Headquartered at the A.J. Muste Institute, the SPUSA's National Office is located at 168 Canal Street in the Chinatown neighborhood of New York City. The party has four chartered state organizations in California, Michigan, Maine and New Jersey as well as twenty eight chartered locals throughout the country. In October 2015, the Socialist Party USA nominated Mimi Soltysik for President and Angela Nicole Walker for Vice President.
  • 3.2K
  • 15 Nov 2022
Topic Review
Argonaut Class Reactor
The Argonaut class reactor is a design of small nuclear research reactor. Many have been built throughout the world, over a wide range of power levels. Its functions are to teach nuclear reactor theory, nuclear physics and for use in engineering laboratory experiments.
  • 2.3K
  • 15 Nov 2022
Topic Review
Ultrafast Laser Spectroscopy
Ultrafast laser spectroscopy is a spectroscopic technique that uses ultrashort pulse lasers for the study of dynamics on extremely short time scales (attoseconds to nanoseconds). Different methods are used to examine dynamics of charge carriers, atoms and molecules. Many different procedures have been developed spanning different time scales and photon energy ranges; some common methods are listed below.
  • 1.1K
  • 15 Nov 2022
Topic Review
Saffron (Use)
In the context of use, Saffron is a key seasoning, fragrance, dye, and medicine in use for over three millennia. From antiquity to modern times the history of saffron is full of applications in food, drink, and traditional herbal medicine: from Africa and Asia to Europe and the Americas the brilliant red threads were—and are—prized in baking, curries, and liquor. It coloured textiles and other items and often helped confer the social standing of political elites and religious adepts. Ancient and medieval peoples believed saffron could be used to treat a wide range of ailments, from stomach upsets to the plague.
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  • 15 Nov 2022
Topic Review
Molten Salt Reactor
A molten salt reactor (MSR) is a class of nuclear fission reactor in which the primary nuclear reactor coolant and/or the fuel is a molten salt mixture. Only two MSRs have ever operated, both research reactors in the United States . The 1950's Aircraft Reactor Experiment was primarily motivated by the compact size that the technique offers, while the 1960's Molten-Salt Reactor Experiment aimed to prove the concept of a nuclear power plant which implements a thorium fuel cycle in a breeder reactor. Increased research into Generation IV reactor designs began to renew interest in the technology, with multiple nations having projects and, as of September 2021, China is on the verge of starting its TMSR-LF1 thorium MSR. MSRs are considered safer than conventional reactors because they operate with fuel already in a molten state, and in event of an emergency, the fuel mixture is designed to drain from the core where it will solidify, preventing the type of nuclear meltdown and associated hydrogen explosions (like what happened in the Fukushima nuclear disaster) that are at risk in conventional (solid-fuel) reactors. They operate at or close to atmospheric pressure, rather than the 75-150 times atmospheric pressure of a typical light-water reactor (LWR), hence reducing the need for large, expensive reactor pressure vessels used in LWRs. Another characteristic of MSRs is that the radioactive fission gases produced are absorbed into the molten salt, as opposed to conventional reactors where the fuel rod tubes must contain the gas. MSR's can also be refueled while operating (essentially online-nuclear reprocessing) while conventional reactors must be shut down for refueling (Heavy water reactors like the CANDU or the Atucha-class PHWRs being a notable exception). A further key characteristic of MSRs is operating temperatures of around 700 °C (1,292 °F), significantly higher than traditional LWRs at around 300 °C (572 °F), providing greater electricity-generation efficiency, the possibility of grid-storage facilities, economical hydrogen production, and, in some cases, process-heat opportunities. Relevant design challenges include the corrosivity of hot salts and the changing chemical composition of the salt as it is transmuted by the neutron flux in the reactor core. MSRs offer multiple advantages over conventional nuclear power plants, although for historical reasons they have not been deployed.
  • 3.6K
  • 15 Nov 2022
Topic Review
Precambrian
The Precambrian (or Pre-Cambrian, sometimes abbreviated pЄ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian (colored green in the timeline figure) is an informal unit of geologic time, subdivided into three eons (Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago (Ga) to the beginning of the Cambrian Period, about 541 million years ago (Ma), when hard-shelled creatures first appeared in abundance.
  • 4.0K
  • 15 Nov 2022
Topic Review
Difference
Difference is a key concept of philosophy, denoting the process or set of properties by which one entity is distinguished from another within a relational field or a given conceptual system. In the Western philosophical system, difference is traditionally viewed as being opposed to identity, following the Principles of Leibniz, and in particular, his Law of the identity of indiscernibles. In structuralist and poststructuralist accounts, however, difference is understood to be constitutive of both meaning and identity. In other words, because identity (particularly, personal identity) is viewed in non-essentialist terms as a construct, and because constructs only produce meaning through the interplay of differences (see below), it is the case that for both structuralism and poststructuralism, identity cannot be said to exist without difference.
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  • 15 Nov 2022
Topic Review
Pillsbury Winthrop Shaw Pittman
Template:Infobox Law Firm Pillsbury is a full-service law firm with an industry focus on the energy and natural resources, financial services including financial institutions, real estate and construction, technology, and travel and hospitality. Based in the world's major financial, technology and energy centers, Pillsbury counsels clients on global business, regulatory and litigation matters. It has approximately 700 attorneys operating from 20 offices in the U.S., London, Asia, and the Middle East. The firm has connections to the two main political parties in the United States. The law firm's two oldest predecessor firms were founded in New York City in 1868 and in San Francisco in 1874, following the California Gold Rush. The San Francisco firm helped create a number of new West Coast businesses including Chevron and Pacific Bell (now known as AT&T). In the 2000s, Pillsbury has become an advocate of labor outsourcing as a means of firms cutting costs by offering services to both buyers and providers of outsourcing services.
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  • 15 Nov 2022
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