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Biography
Barbara Jacak
Barbara Jacak is a nuclear physicist who uses heavy ion collisions for fundamental studies of hot, dense nuclear matter. She is Director of the Nuclear Science Division, Lawrence Berkeley National Laboratory, and a professor of Physics at UC Berkeley.[1] Before going to Berkeley, she was a member of the Department of Physics and Astronomy at Stony Brook University, where she held the rank of Dis
  • 843
  • 06 Dec 2022
Topic Review
Barrier Grid Animation and Stereography
Barrier-grid animation, also known as a kinegram, and "picket fence" animation, which was originated in the late 1890s and then re-popularized by Rufus Butler Seder's trademarked "Scanimation(r)" books in the early 2,000s, is an animation effect created by moving a striped transparent overlay across an interlaced image. The barrier-grid technique and its history overlap with parallax stereography (also known as "Relièphographie") for 3D autostereograms. The technique has also been used for color-changing pictures, but to a much lesser extent. The development of barrier-grid technologies can also be regarded as a step towards lenticular printing, although the technique has remained after the invention of lenticular technologies as a relatively cheap and simple way to produce animated images in print.
  • 845
  • 18 Nov 2022
Topic Review
BatteryMAX (Idle Detection)
BatteryMAX is an idle detection system used for computer power management under operating system control developed at Digital Research, Inc.'s European Development Centre (EDC) in Hungerford, UK. It was created to address the new genre of portable personal computers (laptops) which ran from battery power. As such, it was also an integral part of Novell's PalmDOS 1.0 operating system tailored for early palmtops in 1992.
  • 386
  • 24 Nov 2022
Topic Review
Belgrade Observatory
Belgrade Observatory is an astronomical observatory located in the eastern part of Belgrade, Serbia, in the natural environment of Zvezdara Forest.
  • 283
  • 18 Oct 2022
Topic Review
Bell Test Experiments
A Bell test experiment or Bell's inequality experiment, also simply a Bell test, is a real-world physics experiment designed to test the theory of quantum mechanics in relation to Albert Einstein's concept of local realism. The experiments test whether or not the real world satisfies local realism, which requires the presence of some additional local variables (called "hidden" because they are not a feature of quantum theory) to explain the behavior of particles like photons and electrons. To date, all Bell tests have found that the hypothesis of local hidden variables is inconsistent with the way that physical systems behave. According to Bell's theorem, if nature actually operates in accord with any theory of local hidden variables, then the results of a Bell test will be constrained in a particular, quantifiable way. If a Bell test is performed in a laboratory and the results are not thus constrained, then they are inconsistent with the hypothesis that local hidden variables exist. Such results would support the position that there is no way to explain the phenomena of quantum mechanics in terms of a more fundamental description of nature that is more in line with the rules of classical physics. Many types of Bell test have been performed in physics laboratories, often with the goal of ameliorating problems of experimental design or set-up that could in principle affect the validity of the findings of earlier Bell tests. This is known as "closing loopholes in Bell test experiments". In a novel experiment conducted in 2016, over 100,000 volunteers participated in an online video game that used human choices to produce the data for researchers conducting multiple independent tests across the globe.
  • 4.3K
  • 29 Nov 2022
Topic Review
Bessel Beam
Diffraction is a phenomenon related to the wave nature of light and arises when a propagating wave comes across an obstacle. Consequently, the wave can be transformed in amplitude or phase and diffraction occurs. Those parts of the wavefront avoiding an obstacle form a diffraction pattern after interfering with each other. In this review paper, we have discussed the topic of non-diffractive beams, explicitly Bessel beams. Such beams provide some resistance to diffraction and hence are hypothetically a phenomenal alternate to Gaussian beams in several circumstances. Several outstanding applications are coined to Bessel beams and have been employed in commercial applications. We have discussed several hot applications based on these magnificent beams such as optical trapping, material processing, free-space long-distance self-healing beams, optical coherence tomography, superresolution, sharp focusing, polarization transformation, increased depth of focus, birefringence detection based on astigmatic transformed BB and encryption in optical communication. According to our knowledge, each topic presented in this entry is justifiably explained.
  • 2.6K
  • 09 Dec 2020
Topic Review
Beta (Plasma Physics)
The beta of a plasma, symbolized by β, is the ratio of the plasma pressure (p = n kB T) to the magnetic pressure (pmag = B²/2μ0). The term is commonly used in studies of the Sun and Earth's magnetic field, and in the field of fusion power designs. In the fusion power field, plasma is often confined using strong magnets. Since the temperature of the fuel scales with pressure, reactors attempt to reach the highest pressures possible. The costs of large magnets roughly scales like β½. Therefore, beta can be thought of as a ratio of money out to money in for a reactor, and beta can be thought of (very approximately) as an economic indicator of reactor efficiency. For tokamaks, betas of larger than 0.05 or 5% are desired for economically viable electrical production. The same term is also used when discussing the interactions of the solar wind with various magnetic fields. For example, beta in the corona of the Sun is about 0.01.
  • 352
  • 08 Oct 2022
Topic Review
Beta Function
In theoretical physics, specifically quantum field theory, a beta function, β(g), encodes the dependence of a coupling parameter, g, on the energy scale, μ, of a given physical process described by quantum field theory. It is defined as and, because of the underlying renormalization group, it has no explicit dependence on μ, so it only depends on μ implicitly through g. This dependence on the energy scale thus specified is known as the running of the coupling parameter, a fundamental feature of scale-dependence in quantum field theory, and its explicit computation is achievable through a variety of mathematical techniques.
  • 504
  • 22 Nov 2022
Topic Review
Beyond Special Relativity
There are two different ways in which one can go beyond the kinematics of Special Relativity (SR). One can consider adding to the Standard Model (SM) Lagrangian new terms that violate Lorentz Invariance (LIV). In case one wants to preserve the relativistic invariance, one should modify the transformations between inertial frames and accordingly modify the special relativistic kinematics; this is what is called Doubly/Deformed Special Relativity (DSR). 
  • 407
  • 13 Jul 2022
Topic Review
Biaxial Tensile Test
Biaxial tensile test is a tensile testing in which the sample is stretched in two distinct directions. This technique is used to obtain the mechanical characteristics of anisotropic materials, such as composite materials, textiles, and soft biological tissues. There are three main types of biaxial tensile testing: Bursting test, based on a circular specimen clamped along the edge and inflated by air or water under pressure until the specimen bursts; Cylinder test, based on a hollow cylinder subjected to internal pressure and axial pressure or tension; Plane biaxial test, which offers the best result because of the independent force introduction in the two main directions.
  • 1.3K
  • 28 Oct 2022
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