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Topic Review
Conventional Tools for Neurodegenerative Disease Diagnosis
Conventional approaches in neurodegenerative disease (ND) diagnosis and challenges in clinical routine testing are addressed in order to understand the context of how molecular-based diagnosis techniques can perform in real, in vivo sampling and bioassays for early ND diagnosis.
  • 340
  • 15 May 2023
Topic Review
Quantum Information Education
Quantum information is an emerging scientific and technological discipline attracting a growing number of professionals from various related fields. Although it can potentially serve as a valuable source of skilled labor, the Internet provides a way to disseminate information about education, opportunities, and collaboration.
  • 285
  • 12 May 2023
Topic Review
Methods for Improving Thermal Fatigue Resistance of Copper
Thermal fatigue is the fatigue failure phenomenon caused by the thermal stress (or thermal strain) cycle caused by the temperature gradient cycle. 
  • 365
  • 11 May 2023
Topic Review
Elasticity
In physics and materials science, elasticity is the ability of a body to resist a distorting influence and to return to its original size and shape when that influence or force is removed. Solid objects will deform when adequate loads are applied to them; if the material is elastic, the object will return to its initial shape and size after removal. This is in contrast to plasticity, in which the object fails to do so and instead remains in its deformed state. The physical reasons for elastic behavior can be quite different for different materials. In metals, the atomic lattice changes size and shape when forces are applied (energy is added to the system). When forces are removed, the lattice goes back to the original lower energy state. For rubbers and other polymers, elasticity is caused by the stretching of polymer chains when forces are applied. Hooke's law states that the force required to deform elastic objects should be directly proportional to the distance of deformation, regardless of how large that distance becomes. This is known as perfect elasticity, in which a given object will return to its original shape no matter how strongly it is deformed. This is an ideal concept only; most materials which possess elasticity in practice remain purely elastic only up to very small deformations, after which plastic (permanent) deformation occurs. In engineering, the elasticity of a material is quantified by the elastic modulus such as the Young's modulus, bulk modulus or shear modulus which measure the amount of stress needed to achieve a unit of strain; a higher modulus indicates that the material is harder to deform. The SI unit of this modulus is the pascal (Pa). The material's elastic limit or yield strength is the maximum stress that can arise before the onset of plastic deformation. Its SI unit is also the pascal (Pa).
  • 1.6K
  • 06 May 2023
Topic Review
Structural and Physiochemical Characteristics of Chitosan
Chitosan is a fibrous compound derived from chitin, which is the second most abundant natural polysaccharide and is produced by crustaceans, including crabs, shrimps, and lobsters. Chitosan has all of the important medicinal properties, including biocompatibility, biodegradability, and hydrophilicity, and it is relatively nontoxic and cationic in nature. 
  • 483
  • 04 May 2023
Topic Review
Gallium Nitride Epitaxy
Gallium nitride (GaN) is a wide-bandgap semiconductor material with excellent electrical and optical properties, making it a promising candidate for various electronic and optoelectronic devices. In particular, the unique characteristics of GaN make it a popular choice for high-power and high-frequency applications, such as power electronics, RF amplifiers, and light-emitting diodes (LEDs).
  • 732
  • 25 Apr 2023
Topic Review
Thin Films of Sn Perovskites
Compared to Pb-based perovskites solar cells (PSCs), tin-based perovskite solar cells (TPSCs) exhibit a much lower power conversion energy (PCE), mainly due to the poor film quality, correlated degradation, and detrimental effects. Perovskite films are often fabricated from solutions due to ease of fabrication. In order to create a high-performance tin-based PSC, it is imperative to form dense, compact, well-crystalline perovskite films. Many ways have been proposed to resolve the instabilities of tin-based perovskites. The first step to enhance the stability of the device is to gain a deeper understanding of the degradation mechanisms. Earlier, the researchers briefly pointed out the effects of moisture, oxygen, illumination, ion migration, and chemical reactions which are the most common causes of degradation in perovskite halides.
  • 300
  • 20 Apr 2023
Topic Review
Multicore Fiber Interferometric Sensors
Due to the specificity of fiber structure, i.e., multiple cores integrated into only one fiber cladding, multicore fiber (MCF) interferometric sensors exhibit many desirable characteristics compared with traditional fiber interferometric sensors based on single-core fibers, such as structural and functional diversity, high integration, space-division multiplexing capacity, etc. Thanks to the unique advantages, e.g., simple fabrication, compact size, and good robustness, MCF interferometric sensors have been developed to measure various physical and chemical parameters such as temperature, strain, curvature, refractive index, vibration, flow, torsion, etc., among which the extraordinary vector-bending sensing has also been extensively studied by making use of the differential responses between different cores of MCFs.
  • 336
  • 14 Apr 2023
Topic Review
Short Wavelength Energy-Efficient High-Speed Vertical-Cavity Surface-Emitting Lasers
Vertical-cavity surface-emitting lasers (VCSELs) were becoming the dominating optical sources for data communication in such centers for all distances and wavelengths. VCSELs are of low production cost, can be tested on-wafer, and enable low energy consumption. 850 nm multi-mode VCSELs are widely used for the optical links inside data centers and supercomputers, together with multi-mode fibers. Long-wavelength single-mode VCSELs (1310 nm or 1550 nm) based on InP extend the transmission distance and enable wavelength division multiplexing (WDM) technologies.
  • 426
  • 13 Apr 2023
Topic Review Peer Reviewed
Wavefunction Collapse Broadens Molecular Spectrum
Spectral lines in the optical spectra of atoms, molecules, and other quantum systems are characterized by a range of frequencies ω or a range of wavelengths λ=2πc/ω, where c is the speed of light. Such a frequency or wavelength range is called the width of the spectral lines (linewidth). It is influenced by many specific factors. Thermal motion of the molecules results in broadening of the lines as a result of the Doppler effect (thermal broadening) and by their collisions (pressure broadening). The electric fields of neighboring molecules lead to Stark broadening. The linewidth to be considered here is the so-called parametric broadening (PB) of spectral lines in the optical spectrum. PB can be considered the fundamental type of broadening of the electronic vibrational–rotational (rovibronic) transitions in a molecule, which is the direct manifestation of the basic concept of the collapse of a wavefunction that is postulated by the Copenhagen interpretation of quantum mechanics. Thus, that concept appears to be not only valid but is also useful for predicting physically observable phenomena.
  • 868
  • 11 Apr 2023
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