scholarly journals Thermal response of electronic, optical, mechanical properties, phonon frequencies, and sound velocity of InPxAsySb1-x-y/InAs quaternary semiconductor system

2022 ◽  
Author(s):  
A R Degheidy ◽  
A M AbuAli ◽  
Elkenany B Elkenany
Keyword(s):  
Thermal Properties ◽  
Thermal Response ◽  
Quaternary Alloy ◽  
Potential Method ◽  
Effect Of Temperature ◽  
Virtual Crystal Approximation ◽  
Semiconductor System ◽  
Acoustic Velocities ◽  
Experimental Values ◽  
Pseudo Potential

Abstract The temperature dependence of acoustic velocities, thermal properties, and phonon frequencies, mechanical, electronic, and optical properties for the InPxAsySb1-x-y/InAs system has been studied. The physical properties of the binary components InSb, InP, and InAs that constitute the quaternary alloy were used in this research. The study has been done using the empirical pseudo-potential method (EPM) under the virtual crystal approximation (VCA). The thermal properties, phonon frequencies, and acoustic velocities for the InPxAsySb1-x-y/InAs system under the effect of temperature have not been fully studied. Therefore, we have focused on these properties under the influence of temperature. Due to the lack of the published theoretical and experimental values on these properties, our findings will provide a significant reference for future experimental work.

First-Principles Study on Electronic and Thermal Properties of Zinc-Blende Metal Telluride

2011 ◽  
Vol 335-336 ◽  
pp. 1056-1060
Author(s):  
Dong Chen ◽  
Feng Peng
Keyword(s):  
Crystal Structure ◽  
Heat Capacity ◽  
Thermal Properties ◽  
Plane Wave ◽  
First Principles ◽  
Sharp Increase ◽  
Potential Method ◽  
Zinc Blende ◽  
Structure Density ◽  
Pseudo Potential

The equilibrium crystal structure, band structure, density of states, bulk modulus and its first pressure derivate of CdTe are systemically calculated by first-principles plane-wave pseudo-potential method, and then compared with experimental results. Applying the vibrational Debye-like model, complete sets of isochoric heat capacities can be obtained up to 1000K at pressure or not. With the temperature increasing from 0 to 1000K, a sharp increase in the heat capacity is observed. Moreover, the dependences between cell volume and pressure are also successfully obtained. Our calculated results are in agreement with available results.

Extensions of the Pseudo-Potential Method

2018 ◽  
Author(s):  
Sauro Succi
Keyword(s):  
Potential Method ◽  
Original Model ◽  
Original Formulation ◽  
The Face ◽  
Pseudo Potential

This chapter provides an account of subsequent extensions of the Shan-Chen pseudo-potential method, including more elaborated potentials which extend beyond the first Brillouin cell. These extensions permit us to lift a number of limitations of the original model and considerably expand its scope and range of applications. In Chapter 27, a variety of LB techniques for nonideal fluids have been discussed. As usual, each method comes with its ups and downs, but actual evidence shows that the Shan–Chen (SC) model has enjoyed increasing popularity over the years. Interestingly, such popularity stands in the face of a fair amount of substantial criticism. In this chapter, first the Shan–Chen model is revisited in some more detail along with a discussion of ways out of the above criticism. Subsequently, the extension of the SC technique to the case of multi-range potentials extending beyond the first Brillouin cell is discussed. This extension proves pretty effective in softening many of the weaknesses of the original formulation, thereby considerably expanding its scope and range of applications.

scholarly journals Continental vs. Global Niche-Based Modelling of Freshwater Species’ Distributions: How Big Are the Differences in the Estimated Climate Change Effects?

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 816
Author(s):  
Danijela Markovic ◽  
Jörg Freyhof ◽  
Oskar Kärcher
Keyword(s):  
Climate Change ◽  
Thermal Properties ◽  
Safety Margin ◽  
Thermal Response ◽  
Future Climate Change ◽  
Freshwater Species ◽  
Response Curves ◽  
Preferred Temperature ◽  
Continental Scale ◽  
Management Actions

Thermal response curves that depict the probability of occurrence along a thermal gradient are used to derive various species’ thermal properties and abilities to cope with warming. However, different thermal responses can be expected for different portions of a species range. We focus on differences in thermal response curves (TRCs) and thermal niche requirements for four freshwater fishes (Coregonus sardinella, Pungitius pungitius, Rutilus rutilus, Salvelinus alpinus) native to Europe at (1) the global and (2) European continental scale. European ranges captured only a portion of the global thermal range with major differences in the minimum (Tmin), maximum (Tmax) and average temperature (Tav) of the respective distributions. Further investigations of the model-derived preferred temperature (Tpref), warming tolerance (WT = Tmax − Tpref), safety margin (SM = Tpref − Tav) and the future climatic impact showed substantially differing results. All considered thermal properties either were under- or overestimated at the European level. Our results highlight that, although continental analyses have an impressive spatial extent, they might deliver misleading estimates of species thermal niches and future climate change impacts, if they do not cover the full species ranges. Studies and management actions should therefore favor whole global range distribution data for analyzing species responses to environmental gradients.

scholarly journals Multidisciplinary Approaches for Assessing a High Temperature Borehole Thermal Energy Storage Facility at Linköping, Sweden

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4379
Author(s):  
Max Hesselbrandt ◽  
Mikael Erlström ◽  
Daniel Sopher ◽  
Jose Acuna
Keyword(s):  
Thermal Properties ◽  
High Temperature ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Thermal Response ◽  
Site Investigation ◽  
Thermal Response Test ◽  
Response Test ◽  
Crystalline Bedrock

Assessing the optimal placement and design of a large-scale high temperature energy storage system in crystalline bedrock is a challenging task. This study applies and evaluates various methods and strategies for pre-site investigation for a potential high temperature borehole thermal energy storage (HT-BTES) system at Linköping in Sweden. The storage is required to shift approximately 70 GWh of excess heat generated from a waste incineration plant during the summer to the winter season. Ideally, the site for the HT-BTES system should be able to accommodate up to 1400 wells to 300 m depth. The presence of major fracture zones, high groundwater flow, anisotropic thermal properties, and thick Quaternary overburden are all factors that play an important role in the performance of an HT-BTES system. Inadequate input data to the modeling and design increases the risk of unsatisfactory performance, unwanted thermal impact on the surroundings, and suboptimal placement of the HT-BTES system, especially in a complex crystalline bedrock setting. Hence, it is crucial that the subsurface geological conditions and associated thermal properties are suitably characterized as part of pre-investigation work. In this study, we utilize a range of methods for pre-site investigation in the greater Distorp area, in the vicinity of Linköping. Ground geophysical methods, including magnetic and Very Low-Frequency (VLF) measurements, are collected across the study area together with outcrop observations and lab analysis on rock samples. Borehole investigations are conducted, including Thermal Response Test (TRT) and Distributed Thermal Response Test (DTRT) measurements, as well as geophysical wireline logging. Drone-based photogrammetry is also applied to characterize the fracture distribution and orientation in outcrops. In the case of the Distorp site, these methods have proven to give useful information to optimize the placement of the HT-BTES system and to inform design and modeling work. Furthermore, many of the methods applied in the study have proven to require only a fraction of the resources required to drill a single well, and hence, can be considered relatively efficient.

scholarly journals Ro-vibrational energies of cesium dimer and lithium dimer with molecular attractive potential

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. A. Onate ◽  
T. A. Akanbi ◽  
I. B. Okon
Keyword(s):  
Thermal Properties ◽  
Attractive Potential ◽  
Average Deviation ◽  
Radial Wave ◽  
Lithium Dimer ◽  
Temperature Parameter ◽  
Vibrational Energies ◽  
Experimental Values ◽  
Uvarov Method ◽  
Potential Parameters

AbstractAn approximate solution of the Schrӧdinger equation for a molecular attractive potential was obtained using the parametric Nikiforov–Uvarov method. The energy equation and the corresponding radial wave functions were calculated. The effects of the potential parameters on the energy eigenvalues were examined. The thermal properties under the molecular attractive potential were calculated and the behaviour of the thermal properties with the maximum quantum state (λ) and the temperature parameter (β) respectively, were studied. Using the molecular spectroscopic parameters, the Rydberg–Klein–Rees (RKR) of cesium dimer and lithium dimer were both obtained and compared with the experimental values. The RKR values of both cesium dimer and lithium dimer calculated aligned with the observed values. The deviation and average deviation of the RKR for each molecule were also calculated.

Investigations of the Optical Properties of LaNi5 and LaNi4.5Sn0.5

2013 ◽  
Vol 321-324 ◽  
pp. 495-498 ◽  
Author(s):  
Dong Chen ◽  
Chao Xu
Keyword(s):  
Experimental Data ◽  
Refractive Index ◽  
Optical Properties ◽  
Density Functional ◽  
Low Frequency ◽  
Potential Method ◽  
Frequency Region ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Pseudo Potential

The reflectivity, loss function, refractive index, extinction coefficient and dielectric function of the LaNi5and LaNi4.5Sn0.5intermetallic compounds are investigated through the plane-wave pseudo-potential method based on the density functional theory. The effects of Sn impurity are discussed and some interesting features are found in the low frequency region. Some important optical properties such as static dielectric constant and static refractive index are obtained. The equation [n (0)]2=ε1(0)is satisfied according to our calculation, which indicates that our results are correct and reasonable. Nevertheless, the calculated results need to be testified in the future due to the lack of experimental data.

scholarly journals Structural, elastic, electronic and thermal properties of InAs: A study of functional density

2017 ◽  
Vol 26 (46) ◽  
Author(s):  
Víctor Mendoza-Estrada ◽  
Melissa Romero-Baños ◽  
Viviana Dovale-Farelo ◽  
William López-Pérez ◽  
Álvaro González-García ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Experimental Studies ◽  
Debye Model ◽  
Band Gap Energy ◽  
Functional Theory ◽  
Zinc Blende ◽  
The Density Functional Theory ◽  
The Stability ◽  
Experimental Values

In this research, first-principles calculations were carried out within the density functional theory (DFT) framework, using LDA and GGA, in order to study the structural, elastic, electronic and thermal properties of InAs in the zinc-blende structure. The results of the structural properties (a, B0, ) agree with the theoretical and experimental results reported by other authors. Additionally, the elastic properties, the elastic constants (C11, C12 and C44), the anisotropy coefficient (A) and the predicted speeds of the sound ( , , and ) are in agreement with the results reported by other authors. In contrast, the shear modulus (G), the Young's modulus (Y) and the Poisson's ratio (v) show some discrepancy with respect to the experimental values, although, the values obtained are reasonable. On the other hand, it is evident the tendency of the LDA and GGA approaches to underestimate the value of the band-gap energy in semiconductors. The thermal properties (V, , θD yCV) of InAs, calculated using the quasi-harmonic Debye model, are slightly sensitive as the temperature increases. According to the stability criteria and the negative value of the enthalpy of formation, InAs is mechanically and thermodynamically stable. Therefore, this work can be used as a future reference for theoretical and experimental studies based on InAs.

Numerical simulation of thermal properties at Cu/Al interfaces based on hybrid model

2015 ◽  
Vol 32 (3) ◽  
pp. 574-584
Author(s):  
Yunqing Tang ◽  
Liqiang Zhang ◽  
Haiying Yang ◽  
Juan Guo ◽  
Ningbo Liao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Bonding Temperature ◽  
Dissimilar Materials ◽  
Element Model ◽  
Potential Method ◽  
Interfacial Thermal Resistance ◽  
Interfacial Region ◽  
Fe Model ◽  
Content Type

Purpose – The purpose of this paper is to investigate thermal properties at Cu/Al interfaces. Design/methodology/approach – A hybrid (molecular dynamics-interface stress element-finite element model (MD-ISE-FE) model is constructed to describe thermal behaviors at Cu/Al interfaces. The heat transfer simulation is performed after the non-ideal Cu/Al interface is constructed by diffusion bonding. Findings – The simulation shows that the interfacial thermal resistance is decreasing with the increase of bonding temperature; while the interfacial region thickness and interfacial thermal conductivity are increasing with similar trends when the bonding temperature is increasing. It indicates that the higher bonding temperature can improve thermal properties of the interface structure. Originality/value – The MD-ISE-FE model proposed in this paper is computationally efficient for interfacial heat transfer problems, and could be used in investigations of other interfacial behaviors of dissimilar materials. All these are helpful for the understanding of thermal properties of wire bonding interface structures. It implies that the MD-ISE-FE multiscale modeling approach would be a potential method for design and analysis of interfacial characteristics in micro/nano assembly.

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