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Biography
Ilesanmi Adesida
Ilesanmi Adesida (born 1949, Ifon, Ondo State, Nigeria) is a naturalized United States [1] physicist of Yoruba Nigerian descent.[2] He has been the provost at Nazarbayev University in Astana, Kazakhstan, from September 2016.[3] Adesida is also the Donald Biggar Willett Professor Emeritus of Engineering[4] at the University of Illinois at Urbana-Champaign;[5] he retired from Illinois in 2016. In
  • 506
  • 27 Dec 2022
Topic Review
Loopholes in Bell Test Experiments
In Bell test experiments, there may be problems of experimental design or set-up that affect the validity of the experimental findings. These problems are often referred to as "loopholes". See the article on Bell's theorem for the theoretical background to these experimental efforts (see also John Stewart Bell). The purpose of the experiment is to test whether nature is best described using a local hidden variable theory or by the quantum entanglement theory of quantum mechanics. The "detection efficiency", or "fair sampling" problem is the most prevalent loophole in optical experiments. Another loophole that has more often been addressed is that of communication, i.e. locality. There is also the "disjoint measurement" loophole which entails multiple samples used to obtain correlations as compared to "joint measurement" where a single sample is used to obtain all correlations used in an inequality. To date, no test has simultaneously closed all loopholes. Ronald Hanson of the Delft University of Technology claims the first Bell experiment that closes both the detection and the communication loopholes. (This was not an optical experiment in the sense discussed below; the entangled degrees of freedom were electron spins rather than photon polarization.) Nevertheless, correlations of classical optical fields also violate Bell's inequality. In some experiments there may be additional defects that make "local realist" explanations of Bell test violations possible; these are briefly described below. Many modern experiments are directed at detecting quantum entanglement rather than ruling out local hidden variable theories, and these tasks are different since the former accepts quantum mechanics at the outset (no entanglement without quantum mechanics). This is regularly done using Bell's theorem, but in this situation the theorem is used as an entanglement witness, a dividing line between entangled quantum states and separable quantum states, and is as such not as sensitive to the problems described here. In October 2015, scientists from the Kavli Institute of Nanoscience reported that the Quantum nonlocality phenomenon is supported at the 96% confidence level based on a "loophole-free Bell test" study. These results were confirmed by two studies with statistical significance over 5 standard deviations which were published in December 2015. However, Alain Aspect writes that No experiment can be said to be totally loophole-free.
  • 507
  • 10 Oct 2022
Topic Review
Hercules
Hercules is a prominent constellation in the northern celestial hemisphere, named after the legendary hero from Greek mythology known for his incredible strength and courage. It is the fifth-largest of the 88 modern constellations.
  • 505
  • 15 Mar 2024
Topic Review
Liquid Crystal-Tuned Planar Optics in Terahertz Range
Terahertz waves of higher frequencies compared to microwave and radio frequency have shown great potential in radar detection and high-speed wireless communication. To spatially control the wavefront of terahertz beams, various novel components, such as terahertz filters, polarization converters and lenses, have been investigated. Metamaterials and metasurfaces have become the most promising technique for the free manipulation of terahertz waves. Metadevices integrated with liquid crystals have been widely used in active terahertz devices.
  • 505
  • 17 Feb 2023
Topic Review
Einstein's Constant
Einstein's gravitational constant, denoted κ (kappa), is the constant appearing in the Einstein field equation which can be written: where Gαγ is the Einstein tensor and Tαγ is the stress–energy tensor. This equation relates to the curvature of spacetime, indicating that stress–energy is what causes the curvature of spacetime, thus gravitation. The constant κ is directly related to Newton's gravitational constant G: The above is for the stress–energy tensor in units of mass density (i.e., mass per volume). The units of Einstein's constant depends on how the stress–energy tensor is defined, so an alternative choice for T with units of energy density (i.e., energy per volume) yields
  • 504
  • 14 Nov 2022
Topic Review
Two-Dimensional Nanostructures as Surface-Enhanced Raman Scattering Substrates
Two-dimensional nanostructures (2DNS) attract tremendous interest and have emerged as potential materials for a variety of applications, including biomolecule sensing, due to their high surface-to-volume ratio, tuneable optical and electronic properties. Advancements in the engineering of 2DNS and associated technologies have opened up new opportunities. Surface-enhanced Raman scattering (SERS) is a rapid, highly sensitive, non-destructive analytical technique with exceptional signal amplification potential. Several structurally and chemically engineered 2DNS with added advantages (e.g., π–π* interaction), over plasmonic SERS substrates, have been developed specifically towards biomolecule sensing in a complex matrix, such as biological fluids. 
  • 504
  • 11 Jan 2023
Topic Review
On Ghost Imaging Studies for Information Optical Imaging
To understand, study, and optimize optical imaging systems from the information-theoretic viewpoint has been an important research subfield. However, the "direct point-to-point" image information acquisition mode of traditional optical imaging is lacking in "Coding-decoding" operation on the image information, and limits the development of further imaging capabilities. On the other hand, ghost imaging (GI) systems, combined with modern light-field modulation and digital photoelectric detection technologies, behave more in line with the modulation–demodulation information transmission mode compared to traditional optical imaging. This puts forward imperative demands and challenges for understanding and optimizing ghost imaging systems from the viewpoint of information theory, as well as bringing more development opportunities for the research field of information optical imaging. Here, several specific GI systems and studies with various extended imaging capabilities will be briefly reviewed. 
  • 504
  • 14 Nov 2022
Biography
Mounir Laroussi
File:Mounir Laroussi.tif Mounir Laroussi, is a Tunisian-American scientist. He is known for his work in plasma science, especially low temperature plasmas and their biomedical applications. Mounir Laroussi was born and raised in Sfax, Tunisia, the son of Habib Laroussi and Manana Jeloul. He is the middle child of three siblings. Laroussi attended the Alexander Dumas Elementary School and
  • 504
  • 23 Jan 2023
Biography
Mirza
Mirza Bichurin is Professor and Head of the Department of Design and Technology of Radioelectronic Equipment, Yaroslav-the Wise Novgorod State University, Russia. He has authored 6 books and more than 160 articles in international refereed journals and holds credit for 20 patents. His most famous works: 1.“Magnetoelectricity in Composites.” Eds. M. I. Bichurin and D. Viehland, Pan Stanf
  • 503
  • 29 Jan 2023
Topic Review
Soyuz TMA-20
Soyuz TMA-20 was a human spaceflight to the International Space Station (ISS) and was part of the Soyuz programme. It lifted off from the Baikonur Cosmodrome in Kazakhstan on December 15, 2010, and docked with the ISS two days later. The three-person crew of Soyuz TMA-20 – Dmitri Kondratyev, Catherine Coleman and Paolo Nespoli – represented the ISS partner organizations of Roscosmos, NASA and the European Space Agency (ESA). Soyuz TMA-20's crew represented half of the members of Expedition 27; the other three members of the expedition arrived at the station on board Soyuz TMA-21 on April 6, 2011. The COSPAR ID of Soyuz TMA-20 was 2010-067A. It is ISS flight 25S. On May 24, 2011, after spending 159 days in space, the Soyuz TMA-20 descent module landed safely in Zhezkazgan, Kazakhstan, carrying Kondratyev, Coleman and Nespoli.
  • 503
  • 17 Nov 2022
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