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Introduction to Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
So, the “height of the surface” is somewhat arbitrarily defined as the tip–sample separation for which tunneling current is fixed at a particular constant value, Iset, for a particular applied bias voltage, Vset. In practical terms, a fixed current is chosen at −100 pA, for a bias voltage of −100 mV. This is arbitrary but gains support from the fact that, in accordance with expectations, atoms and other structural features are not seen, even over a wider range of choices of Iset and Vset. The most widely varying DOS features of the superconducting samples studied so far appear to be within 75 meV of the Fermi level. Superconductivity is the occurrence of zero electrical resistance in certain materials below a characteristic temperature.
The evolution of future societies with unlimited energy supply?
Published in Kléber Ghimire, Future Courses of Human Societies, 2018
Superconductors are generally classified by critical temperature, the temperature below which those materials show the superconductivity phenomena. Superconductor materials include elements such as, for example, mercury, lead or carbonium (in a particular configuration such as fullerenes and nanotubes), several alloys such as niobium-titanium, germanium-niobium, niobium nitride and ceramics as MgB2. These materials have a critical transition temperature to superconductor state from −265°C to −230°C, thus require very expensive and complicated technologies to manage such low temperatures on a large scale. In 1985, a new class of superconductors was discovered, called high temperature superconductors (YBCO and BISCO). These materials show the phenomenon of superconductivity at higher temperatures (when cooled with liquid nitrogen at −200°C). This discovery fostered the hope that human societies will develop a superconductor material that shows the superconductivity phenomenon at room temperature (Keimer et al., 2015, pp. 179–186).
Induction Mass Heating
Published in Valery Rudnev, Don Loveless, Raymond L. Cook, Handbook of Induction Heating, 2017
Valery Rudnev, Don Loveless, Raymond L. Cook
Theoretically speaking, the phenomenon of superconductivity can be used to drastically reduce the value of ρcoil and, therefore, significantly improve coil efficiency particularly when heating low-resistive metals. Studies show that because of the phenomenon of superconductivity when heating aluminum billets, the coil electrical efficiency can be increased from approximately 45%–55% to 80%–88%. Unfortunately, in order to create a condition for the existence of superconductivity, it is necessary to have extremely low subfreezing temperatures. In order to create such low temperatures, it is necessary to use liquid nitrogen for cooling coil turns instead of water. Such an approach would result in a significant increase of the capital cost of the equipment, leading to difficulty in providing a cost-effective, reliable, and robust system. Besides that, although the coil electrical efficiency can be noticeably improved when cooled with liquid nitrogen, the system total efficiency can still suffer because of poor efficiency of the cryogenic system.
Automatic knowledge acquisition from superconductivity information in literature
Published in Science and Technology of Advanced Materials: Methods, 2023
Kento Mitsui, Yutaka Sasaki, Ryoji Asahi
Research on information extraction in materials science has gained momentum over the past few years [3–8]. Watson et al. proposed a method for extracting terms, such as material compositions and analytical methods, for inorganic materials [8], and Friedrich et al. proposed an information extraction task related to solid oxide fuel cells [7]. However, the corpus of materials, that includes compositions, structures, properties, synthesis processing, and analyses, remains in an early stage of development. Superconducting material is an important research field in science and technology, with a wide range of applications. In particular, the development of high-temperature superconductors able to exhibit superconductivity at higher transition temperatures (typically than 77 K, the boiling temperature of liquid nitrogen) has been intensively pursued for practical applications, such as linear bullet trains, medical analyses, and solutions to energy problems. To this end, the exploration of new superconducting materials remains a popular issue.
SuperMat: construction of a linked annotated dataset from superconductors-related publications
Published in Science and Technology of Advanced Materials: Methods, 2021
Luca Foppiano, Sae Dieb, Akira Suzuki, Pedro Baptista de Castro, Suguru Iwasaki, Azusa Uzuki, Miren Garbine Esparza Echevarria, Yan Meng, Kensei Terashima, Laurent Romary, Yoshihiko Takano, Masashi Ishii
Entities (also referred as Named Entities, mentions, or surface forms) are chunks of texts that represent an information of interest, as follow: Class (tag: <class>) represents a group of materials defined by certain characteristics. Superconducting materials can be classified according to different criteria such as the composition and magnetic properties. Among publications collected for this study, the domain experts identified three types of classes based on: (a) the composition and crystal structure, (b) material phenomena (e.g. “I-type” and “II-type superconductivity”, “BCS superconductors”, “nematic”, and “conventional/unconventional superconductivity”), and (c) high/low Tc value (e.g. “high-tc” superconductors).
Numerical simulation for peristaltic transport of radiative and dissipative MHD Prandtl nanofluid through the vertical asymmetric channel in the presence of double diffusion convection
Published in Numerical Heat Transfer, Part B: Fundamentals, 2023
Variable electrical conductivity, or VEC, is not taken into account in the works mentioned above. The application of an electric field, however, is one of the most efficient ways to improve heat transport. This technology can be combined with nanofluid, another passive technique. Additionally, by choosing fluids with the proper electrical conductivity, engineers may control the metallurgical processes. In the same context, to optimize electronic applications such refrigerators, heat engines, air conditioners, and heat pumps, the examination of the temperature- and concentration-dependent electrical conductivity instances is more crucial. The first definition of electrical conductivity is provided by Sakai et al. [67] study results, which also specify the particular resistance of metals at relatively low temperature to determine whether it would continue to decrease linearly with the temperature reduction or would be fixed at a particular value. Slightly earlier on, scientists, modelers, and investigators studied how electrical conductivity affected its many applications, including superconductivity in cables and medical mechanisms like magnetic resonance imaging devices, digital electrical circuits, and particle accelerators. For more information, see Refs. [68–72]. A suggestion for the effect of electrical conductivity modification on the flowing of Casson nanofluid was made in the context of fluids by Obalalu et al. [73]. They hypothesized that the fluid’s temperature had an inverse relationship with electrical conductivity. As a contrast, Qasim et al. [74] investigated how Joule dissipation affected the peristaltic transfer of nanofluid flow. They suggested that there is a direct correlation between electrical conductivity and fluid temperature. This work introduces a novel theoretical perspective on the relationship between fluid temperature and concentration and electrical conductivity. Recently, [75] investigated how non-Newtonian nanofluid pasting radially stretched surfaces were affected by varying electrical conductivity. [76] looked into the impact of varying electrical conductivity on MHD convective flow in conjunction with a vertical isothermal plate. They discovered that the temperature profile is improved by the variable electrical conductivity parameter.