China
Africa
Explore chapters and articles related to this topic
Introduction to Nanosensors
Published in Vinod Kumar Khanna, Nanosensors, 2021
Temperature is a measure of the degree of hotness or coldness of a body, that is, the average kinetic energy of the molecules of the body. Absolute zero is the theoretical lowest attainable temperature = –273.15°C or 0 K, at which all atomic motion has ceased. It cannot be attained because it requires an infinite amount of energy.
Introduction to Energy, Heat and Thermodynamics
Published in S. Bobby Rauf, Thermodynamics Made Simple for Energy Engineers, 2021
Unlike the Celsius temperature scale system, where 0°C represents the freezing point of water, the absolute temperature scale defines temperature independent of the properties of any specific substance. According to the laws of thermodynamics, absolute zero cannot be reached because this would require a thermodynamic system to be fully removed from the rest of the universe. Absolute zero is the theoretical temperature at which entropy would reach its minimum value. Absolute zero is defined as 0°K on the Kelvin scale and as −273.15°C on the Celsius scale. This equates to −459.67°F on the Fahrenheit scale.
Concepts and Principal Provisions of Fundamental and Applied Superconductivity
Published in V.R. Romanovskii, Basic Macroscopic Principles of Applied Superconductivity, 2021
Bardeen, Cooper and Schrieffer advanced the understanding of superconductivity through the microscopic theory of superconductivity (Bardeen et al. 1957). It explains superconductivity at temperatures close to absolute zero. Their theory offered that atomic lattice vibrations affect the entire current in the superconductor. They force the electrons to pair up into teams that could pass all the obstacles, which cause the resistance of a normal conductor.
A novel AI approach for modeling land surface temperature of Freetown, Sierra Leone, based on land-cover changes
Published in International Journal of Digital Earth, 2022
Mosbeh R. Kaloop, Mudassir Iqbal, Mohamed T. Elnabwy, Elhadi K. Mustafa, Jong Wan Hu
Where, is the wavelength of emitted radiance (11.5 µm) (Tarawally, Xu et al. 2018), , is the Stefan–Boltzmann’s constant (1.38 × 10−23 JK−1), is the Planck’s constant (6.26 × 10−34 Js), is the velocity of light (2.998 × 108 ms−1), and is the surface emissivity. Finally, the derived values were converted to the conventional Degree Celsius (°C) unit by adding the absolute zero, which is approximately minus 273.5°C.
Atomic scale study of the anti-vortex domain structure in polycrystalline ferroelectric
Published in Philosophical Magazine, 2018
Xiaobao Tian, Xiaoqiao He, Jian Lu
In this simulation, the BaTiO3 (BTO) polycrystal consists of 12 hexagonal grains with 10 nm diameter and 2.4 nm height (Figure 1(a)). The hexagonal grains has been found in an experiment [20]. The crystallographic axis of grain can rotate in the x–y plane, which leads to a different polarisation distribution marked with different colours in Figure 1(b). Each hexagonal grain has different orientation and the GB is formed due to the different grain orientations as marked by the local coordinate axis which is shown in each grain with labels from 1 to 12. The tips for building the GB sample is deleting the lattice cell to which an atom belongs in the GB critical region following the Pauli Exclusion Principle. Therefore, the GBs can keep the electron zero and the electric field is suitable for structure balance. Vacancy due to the deleting atom is relaxed by the MD simulation. Finally, the atomic position on the GB or the GB width is determined by the grain interaction which can be changed under external force fields and external constrains. Moreover, the simulation results demonstrate that the polarisation is almost the same along the height direction of hexagonal grains and, thus, only the polarisation distribution in the x-y plane is presented in the following simulations in which periodic boundary conditions are imposed on all surfaces of the model and electric boundary conditions on all sample surfaces are open-circuited. The temperature is set as 5 Kelvin near absolute zero, but particles are still active and can move easily to proper positions [25].
Order–disorder competition in equiatomic 3d–transition–metal quaternary alloys: phase stability and electronic structure
Published in Science and Technology of Advanced Materials: Methods, 2023
Hiroshi Mizuseki, Ryoji Sahara, Kenta Hongo
One of the main objectives of this study is to investigate whether a semi-ordered phase (OP0) is more stabilized than the corresponding RSS for each studied quaternary alloy. That is, we intended to determine the ‘crossover’ temperature () at which the phase transition between the OP0 and RSS occurs for each composite of the quaternary alloy. Therefore, it is important to consider the configurational entropy term to discuss phase stability in HEAs in the finite temperature region. It is imperative to quantitatively analyze the influences of VEC and temperature on the stable HEA crystal structures for investigating the order–disorder competition and phase stability. This is because the enthalpy term defined at the absolute zero temperature correlates with VEC, whereas the entropy effect is temperature dependent; the most stable phase is determined by free energy, i.e. the sum of the enthalpy and entropy terms. Guo et al [40,41]. reported several HEA systems wherein the single FCC phase was stable in the region of VEC , the single BCC phase was stable in the region of VEC , and the mixed FCC and BCC phases appeared in the region of . The average VEC values of magnetic HEAs are greater than 7.50, and therefore, they possess the FCC structure. The present study considers only single FCC phases in order to systematically elucidate a VEC dependence of their relative stability within the FCC crystal system, thereby clarifying our discussion. Hence, this study does not focus on the lattice type of magnetic HEAs, but on their magnetic orderings.