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Topic Review
Anomaly
In quantum physics an anomaly or quantum anomaly is the failure of a symmetry of a theory's classical action to be a symmetry of any regularization of the full quantum theory. In classical physics, a classical anomaly is the failure of a symmetry to be restored in the limit in which the symmetry-breaking parameter goes to zero. Perhaps the first known anomaly was the dissipative anomaly in turbulence: time-reversibility remains broken (and energy dissipation rate finite) at the limit of vanishing viscosity. In quantum theory, the first anomaly discovered was the Adler–Bell–Jackiw anomaly, wherein the axial vector current is conserved as a classical symmetry of electrodynamics, but is broken by the quantized theory. The relationship of this anomaly to the Atiyah–Singer index theorem was one of the celebrated achievements of the theory. Technically, an anomalous symmetry in a quantum theory is a symmetry of the action, but not of the measure, and so not of the partition function as a whole.
  • 580
  • 04 Nov 2022
Topic Review Video
Black Hole
Black holes are the celestial objects existing at the center of every galaxy. They can currently only be described by their spin, charge, and angular momentum, with other attributes derived from the basic properties. The existence of black holes was first predicted by German physicist and astronomer Karl Schwarzschild in 1916, with the exact solutions to Einstein's field equations of general relativity one year after its publication. Finnish physicist Gunnar Nordström proposed a theory of gravity and electromagnetism with four spatial dimensions in 1914, and later developed into the stationary charged black hole in 1918.
  • 581
  • 15 Oct 2023
Topic Review
Endeavour House
Endeavour House is the Suffolk County Council headquarters located in Ipswich, Suffolk, England. Endeavour House was originally owned by the American-based energy and electric company, TXU Corporation. Located on Russell Road Ipswich, England ; Endeavour House was constructed between 2001 and 2003 by Bovis Lend Lease (now Lend Lease Project Management & Construction) contractors as well as M&S contractors and was designed by TTSP architects. The building had an original construction cost of £28 million (Suffolk County Council paid £16.75 million for the building) and is one of the most energy efficient office buildings in Europe.
  • 579
  • 17 Oct 2022
Biography
Prabhakar Misra
Prabhakar Misra is an American physicist, who researches and teaches at Howard University in Washington, D.C., and is currently a Professor in the Department of Physics and Astronomy. Born and raised in India, he came to the United States to pursue graduate studies in physics. He earned an M.S. in Physics from Carnegie Mellon University in 1981 (Pittsburgh, Pennsylvania), followed by a Ph D.
  • 579
  • 25 Nov 2022
Biography
Franz Josef Giessibl
Franz Josef Gießibl (born 27 May 1962 in Amerang) is a Germany physicist and university professor at the University of Regensburg. Giessibl studied physics from 1982 to 1987 at the Technical University of Munich and at Eidgenössische Technischen Hochschule Zürich. He received a diploma in experimental physics in 1988 with Professor Gerhard Abstreiter and continued with a PhD in physics wit
  • 579
  • 12 Dec 2022
Topic Review
Computational Simulations of Heart Valves
Computational methods are a cost-effective tool that can be used to evaluate the flow parameters of heart valves. Valve repair and replacement have long-term stability and biocompatibility issues, highlighting the need for a more robust method for resolving valvular disease. For example, while fluid–structure interaction analyses are still scarcely utilized to study aortic valves, computational fluid dynamics is used to assess the effect of different aortic valve morphologies on velocity profiles, flow patterns, helicity, wall shear stress, and oscillatory shear index in the thoracic aorta. It has been analyzed that computational flow dynamic analyses can be integrated with other methods to create a superior, more compatible method of understanding risk and compatibility.
  • 577
  • 10 May 2022
Biography
Shin-Tson Wu
Shin-Tson Wu, (Chinese:吳詩聰) is an American physicist and inventor. He is currently a Pegasus professor at CREOL, The College of Optics and Photonics, University of Central Florida. Wu's contributions to liquid-crystal research and the resulting patent portfolio for next-generation liquid crystal displays (LCDs), adaptive optics, laser-beam steering, biophotonics, and new photonic materials
  • 577
  • 28 Nov 2022
Topic Review
Luminescent Carbon Nanoparticles
Among the newest nanostructured luminescent materials, carbon nanoparticles, commonly known as carbon nanodots (CNDs), are of special interest. The term CNDs is commonly used to refer to carbonaceous particles with a size of less than 10 nm. However, the structure and morphology of these particles can be quite diverse. They can include nanoparticles of diamond and graphite, as well as amorphous nanoparticles with a diamond-like, polymer-like, or graphite-like structure. Nanoflakes of graphene and graphene oxide are also often referred to as CNDs. This manuscript referes to luminescent carbon nanoprecipitates synthesised by pyrolysis/thermolysis of organic precursors and  despersed in nanoporous silicas.
  • 577
  • 20 Dec 2021
Topic Review
Polarization Lidar
Traditional lidar techniques mainly rely on the backscattering/echo light intensity and spectrum as information sources. In contrast, polarization lidar (P-lidar) expands the dimensions of detection by utilizing the physical property of polarization. By incorporating parameters such as polarization degree, polarization angle, and ellipticity, P-lidar enhances the richness of physical information obtained from target objects, providing advantages for subsequent information analysis.
  • 575
  • 12 Oct 2023
Topic Review
Biological Small-Angle Scattering
Biological small-angle scattering is a small-angle scattering method for structure analysis of biological materials. Small-angle scattering is used to study the structure of a variety of objects such as solutions of biological macromolecules, nanocomposites, alloys, and synthetic polymers. Small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) are the two complementary techniques known jointly as small-angle scattering (SAS). SAS is an analogous method to X-ray and neutron diffraction, wide angle X-ray scattering, as well as to static light scattering. In contrast to other X-ray and neutron scattering methods, SAS yields information on the sizes and shapes of both crystalline and non-crystalline particles. When used to study biological materials, which are very often in aqueous solution, the scattering pattern is orientation averaged. SAS patterns are collected at small angles of a few degrees. SAS is capable of delivering structural information in the resolution range between 1 and 25 nm, and of repeat distances in partially ordered systems of up to 150 nm in size. Ultra small-angle scattering (USAS) can resolve even larger dimensions. The grazing-incidence small-angle scattering (GISAS) is a powerful technique for studying of biological molecule layers on surfaces. In biological applications SAS is used to determine the structure of a particle in terms of average particle size and shape. One can also get information on the surface-to-volume ratio. Typically, the biological macromolecules are dispersed in a liquid. The method is accurate, mostly non-destructive and usually requires only a minimum of sample preparation. However, biological molecules are always susceptible to radiation damage. In comparison to other structure determination methods, such as solution NMR or X-ray crystallography, SAS allows one to overcome some restraints. For example, solution NMR is limited to protein size, whereas SAS can be used for small molecules as well as for large multi-molecular assemblies. Solid-State NMR is still an indispensable tool for determining atomic level information of macromolecules greater than 40 kDa or non-crystalline samples such as amyloid fibrils. Structure determination by X-ray crystallography may take several weeks or even years, whereas SAS measurements take days. SAS can also be coupled to other analytical techniques like size-exclusion chromatography to study heterogeneous samples. However, with SAS it is not possible to measure the positions of the atoms within the molecule.
  • 576
  • 09 Oct 2022
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