Related Research Articles
In physics, the term dielectric strength has the following meanings:
Space charge is a concept in which excess electric charge is treated as a continuum of charge distributed over a region of space rather than distinct point-like charges. This model typically applies when charge carriers have been emitted from some region of a solid—the cloud of emitted carriers can form a space charge region if they are sufficiently spread out, or the charged atoms or molecules left behind in the solid can form a space charge region.
A Lichtenberg figure, or Lichtenberg dust figure, is a branching electric discharge that sometimes appears on the surface or in the interior of insulating materials. Lichtenberg figures are often associated with the progressive deterioration of high voltage components and equipment. The study of planar Lichtenberg figures along insulating surfaces and 3D electrical trees within insulating materials often provides engineers with valuable insights for improving the long-term reliability of high-voltage equipment. Lichtenberg figures are now known to occur on or within solids, liquids, and gases during electrical breakdown.
Electrical breakdown or dielectric breakdown is a process that occurs when an electrical insulating material, subjected to a high enough voltage, suddenly becomes an electrical conductor and electric current flows through it. All insulating materials undergo breakdown when the electric field caused by an applied voltage exceeds the material's dielectric strength. The voltage at which a given insulating object becomes conductive is called its breakdown voltage and depends on its size and shape. Under sufficient electrical potential, electrical breakdown can occur within solids, liquids, gases or vacuum. However, the specific breakdown mechanisms are different for each kind of dielectric medium.
The breakdown voltage of an insulator is the minimum voltage that causes a portion of an insulator to become electrically conductive.
Diffusion-limited aggregation (DLA) is the process whereby particles undergoing a random walk due to Brownian motion cluster together to form aggregates of such particles. This theory, proposed by T.A. Witten Jr. and L.M. Sander in 1981, is applicable to aggregation in any system where diffusion is the primary means of transport in the system. DLA can be observed in many systems such as electrodeposition, Hele-Shaw flow, mineral deposits, and dielectric breakdown.
In statistical mechanics, universality is the observation that there are properties for a large class of systems that are independent of the dynamical details of the system. Systems display universality in a scaling limit, when a large number of interacting parts come together. The modern meaning of the term was introduced by Leo Kadanoff in the 1960s, but a simpler version of the concept was already implicit in the van der Waals equation and in the earlier Landau theory of phase transitions, which did not incorporate scaling correctly.
Fereydoon Family is a leading Persian physicist in the field of nanotechnology and solid-state physics. He is currently Samuel Candler Dobbs Professor of Physics and a member of the Emerson Center for Scientific Computation at Emory University in Atlanta, Georgia. He is an elected fellow of the American Physical Society, and a recipient of the Southeastern Section of the American Physical Society's highest honor, the J.W. Beams Award.
A capacitor is a device that stores electrical energy in an electric field. It is a passive electronic component with two terminals.
Dielectric elastomers (DEs) are smart material systems that produce large strains. They belong to the group of electroactive polymers (EAP). DE actuators (DEA) transform electric energy into mechanical work. They are lightweight and have a high elastic energy density. They have been investigated since the late 1990s. Many prototype applications exist. Every year, conferences are held in the US and Europe.
The antenna effect, more formally plasma induced gate oxide damage, is an effect that can potentially cause yield and reliability problems during the manufacture of MOS integrated circuits. Factories (fabs) normally supply antenna rules, which are rules that must be obeyed to avoid this problem. A violation of such rules is called an antenna violation. The word antenna is something of a misnomer in this context—the problem is really the collection of charge, not the normal meaning of antenna, which is a device for converting electromagnetic fields to/from electrical currents. Occasionally the phrase antenna effect is used in this context, but this is less common since there are many effects, and the phrase does not make clear which is meant.
DP is a free software package for physicists implementing ab initio linear-response TDDFT in frequency-reciprocal space and on a plane wave basis set. It allows to calculate both dielectric spectra, such as EELS, IXSS and CIXS, and also optical spectra, e.g. optical absorption, reflectivity, refraction index. The systems range from periodic/crystalline solids, to surfaces, clusters, molecules and atoms made of insulators, semiconductors and metal elements. It implements the RPA, the TDLDA or ALDA plus other non-local approximations, including or neglecting local-field effects. It is distributed under the scientific software open-source academic for free license.
Boris Valerianovich Chirikov was a Soviet and Russian physicist. He was the founder of the physical theory of Hamiltonian chaos and made pioneering contributions to the theory of quantum chaos. In 1959, he invented the Chirikov criterion which gives an analytical estimate for the overlap of resonances and provides the conditions for transition from integrability to global chaos in Hamiltonian dynamical systems.
Luciano Pietronero is an Italian physicist and full professor at the department of Physics at the Sapienza University of Rome. He is also Director of the Institute of Complex Systems of the National Research Council.
In solid-state physics, the Poole–Frenkel effect is a model describing the mechanism of trap-assisted electron transport in an electrical insulator. It is named after Yakov Frenkel, who published on it in 1938, extending the theory previously developed by H. H. Poole.
A diffusion-limited enzyme catalyses a reaction so efficiently that the rate limiting step is that of substrate diffusion into the active site, or product diffusion out. This is also known as kinetic perfection or catalytic perfection. Since the rate of catalysis of such enzymes is set by the diffusion-controlled reaction, it therefore represents an intrinsic, physical constraint on evolution. Diffusion limited perfect enzymes are very rare. Most enzymes catalyse their reactions to a rate that is 1,000-10,000 times slower than this limit. This is due to both the chemical limitations of difficult reactions, and the evolutionary limitations that such high reaction rates do not confer any extra fitness.
Vascular remodelling is a process which occurs when an immature heart begins contracting, pushing fluid through the early vasculature. The process typically begins at day 22, and continues to the tenth week of human embryogenesis. This first passage of fluid initiates a signal cascade and cell movement based on physical cues including shear stress and circumferential stress, which is necessary for the remodelling of the vascular network, arterial-venous identity, angiogenesis, and the regulation of genes through mechanotransduction. This embryonic process is necessary for the future stability of the mature vascular network.
The index of physics articles is split into multiple pages due to its size.
Thomas Witten is an American theoretical physicist working in the field of soft matter physics.
Dynamic scaling is a litmus test that shows whether an evolving system exhibits self-similarity. In general a function is said to exhibit dynamic scaling if it satisfies:
References
- ↑ Niemeyer, L.; Pietronero, L.; Wiesmann, H. J. (1984-03-19). "Fractal Dimension of Dielectric Breakdown". Physical Review Letters. American Physical Society (APS). 52 (12): 1033–1036. Bibcode:1984PhRvL..52.1033N. doi:10.1103/physrevlett.52.1033. ISSN 0031-9007.
