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Engineered products
Published in Mike Tooley, Engineering GCSE, 2012
Materials with a very low resistance to the flow of an electric current are good electrical conductors. Materials with a very high resistance to the flow of electric current are good insulators. Generally, metals are good conductors and non-metals are good insulators (poor conductors). A notable exception is carbon which conducts electricity despite being a non-metal. The electrical resistance of a metal conductor depends upon: Its length (the longer it is the greater its resistance)Its thickness (the thicker it is the lower its resistance)Its temperature (the higher its temperature the greater is its resistance)Its resistivity (this is the resistance measured between the opposite faces of a metre cube of the material).
Electrical separation
Published in D.V. Subba Rao, Mineral Beneficiation, 2011
Examples of conductors include metals, aqueous solutions of salts, graphite, water and the human body. Examples of insulators include plastics, paper, rubber, glass, wood and dry air. Some materials are neither good conductors nor good insulators, since their electrical characteristics fall between those of conductors and insulators. These in-between materials are classified as Semi-conductors. Germanium and silicon are two common semiconductors. Different materials may be placed along a continuum as in figure 18.1. The conductivity of a metal might be as much as a million trillion times greater than that of glass.
Insulation, Coatings, and Adhesives in Transmission and Distribution Electrical Equipment
Published in Bella H. Chudnovsky, Transmission, Distribution, and Renewable Energy Generation Power Equipment, 2017
In electrical systems, insulators are commonly used as a flexible coating on electric wire and cable to avoid wires from touching each other and be touched, and therefore preventing electrocution and fire hazards. In coaxial cables, the center conductor must be supported exactly in the middle of the hollow shield in order to prevent electromagnetic wave reflections. An insulated wire or cable has a voltage rating and a maximum conductor temperature rating. It may not have an ampacity (current-carrying capacity) rating, since this depends on the surrounding environment (e.g., ambient temperature).
Equivalent Salt Deposit Density Prediction of Silicone Rubber Insulators Under Simulated Pollution Conditions
Published in Electric Power Components and Systems, 2018
Abdelrahman K. Abouzeid, Ayman El-Hag, Khaled Assaleh
In both distribution and transmission systems [1], outdoor insulators first support overhead lines to withstand different mechanical loads, resulting from tensile, vibration, and compression forces under steady state conditions. Secondly, when the insulators electrically isolate the bare conductors from the surrounding structures, they need to withstand the steady state electric stress as well as the transient stresses resulted from lightning and switching events. Both the electrical and mechanical roles of outdoor insulators are performed in varying environmental conditions, which include temperature variations, moisture, contamination, and ultra-violet radiation from sunlight.
Scattering of elastic wave from poroelastic inclusions located in a fluid
Published in Waves in Random and Complex Media, 2022
Mikhail Markov, Anatoly Markov
In the current work, we have obtained the solution of the problem of the scattering of an elastic compressional wave on a porous inclusion located in a fluid. The solution of this problem is of technical interest in connection with the development of acoustic insulators. Such insulators can be used, for example, in geophysics, when creating measuring devices for boreholes or in shipbuilding, when designing the hulls of underwater vessels.
Synthesis, spectroscopic characterization and solid-state electrical behavior of [Ni(L)2] [L = 1,2-di(4-methoxyphenyl)ethene-1,2-dithiolate]: a computational investigation on UV–vis-NIR absorption and electrical transport
Published in Journal of Coordination Chemistry, 2023
Arghya Dutta, Sanjay Mondal, Soumya Biswas, Vinayak B Kamble, Shubhamoy Chowdhury, Rajarshi Ghosh
The electric conductivity depends on HOMO-LUMO energy band gap. Materials with large band gaps (more than 4 eV) are insulators. In contrast, materials having band gap of 1.5–3.0 eV are considered as semiconductors, whereas about 0.0 eV band gap materials are metals [19]. The electrical conductivity of a molecular device can be calculated by DFT [20].