Experimental studies of structural, electrical and thermal properties of multifunctional BiFeO3 ceramic

2019 ◽  
Author(s):  
Vikash Kumar Jha ◽  
M. Roy ◽  
S. N. Alam
Keyword(s):  
Thermal Properties ◽  
Experimental Studies ◽  
Bifeo3 Ceramic

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.

Recycled Polymer Concrete Composite: A Retrospective Review of the Literature and Framework for Thermal Comfort in Homes

2020 ◽  
Vol 1015 ◽  
pp. 15-21
Author(s):  
Cesar Humberto Ortega-Jimenez ◽  
Eduardo Ardón ◽  
Jose Pineda ◽  
Carlos Ventura ◽  
Carlos Núñez ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Thermal Comfort ◽  
Polymer Composite ◽  
Building Materials ◽  
Materials Science ◽  
Experimental Studies ◽  
Concrete Block ◽  
Polymer Concrete ◽  
Future Research ◽  
Testing And Evaluation

The aim of this paper is to review the literature on Materials science to identify the current research and to provide direction for future research in thermal properties of the concrete block composite, either with Polyethylene Terephthalate (PET) or Polystyrene (PS), presenting the opportunity to make an important methodological contribution by applying systematic review in three areas of Materials science: Composites, Building Materials, as well as Testing and Evaluation of Materials. This is a growing interdisciplinary field since there are no current comparative papers addressing both PET and PS in the same research for concrete composites. Papers investigating to what extent, what type and how academic publications are integrated on the analysis of the characteristics of the two recycled polymers (PET and PS), to improve the thermal properties of the concrete block and contribute to the research of sustainable thermal comfort in homes. They were reviewed, keywords were identified within a framework of composites, building materials, as well as testing and evaluation of materials, and a lexical analysis of the papers was conducted. The results of current research show that both forms of recycling (PS and PET), combined with concrete, have sustainability in thermal comfort. The analysis reveals that previous research has focused on PET-Concrete (i.e., concrete-PET polymer composite) since it is more viable, due to its large amount of recycling. While this has benefited home builders in their ability to respond with some thermal comfort with higher construction efficiency, it also clarifies that there has been research done on PS-Concrete (i.e., concrete-PS polymer composite), presenting greater thermal comfort, because it has lower thermal conductivity. This finding suggests the need for further research within this narrow field, with absence of data, since most prescriptive recommendations have not been tested and lack practical applications, which is why the need for more empirical and experimental studies are identified. Based on the novelty of the PET or PS recycling concepts, we highlight the need of better collaboration between academic disciplines, such as engineering and architecture to provide better experimental evidence for recycling of polymers, including empirical approaches for the different types of composites and aggregate distributions, which can be made with concrete to improve thermal insulation performance and energy savings for manufacturers.

scholarly journals INVESTIGATION OF THE INTERACTION OF UDP METALS WITH PRODUCTS OF THERMAL DECOMPOSITION OF TETRAZOLE BINDER

2021 ◽  
pp. 276-280
Author(s):  
М.В. Комарова ◽  
А.Г. Вакутин
Keyword(s):  
Thermal Decomposition ◽  
Thermal Properties ◽  
Nickel Alloys ◽  
Experimental Studies ◽  
Metal Powders ◽  
Iron Powders ◽  
Iron Aluminum ◽  
Ultrafine Metal ◽  
Titanium Zinc ◽  
Zinc Nickel

В статье приводятся экспериментальные исследования ультрадисперсных металлических порошков алюминия, меди, железа, вольфрама, титана, цинка, никеля, сплавов меди с алюминием, меди с железом и латуни. Описаны термические свойства их смесей с метилполивинилтетразолом, пластифицированным динитратпропиленгликолем; указаны численные величины значимых характеристик.Результаты исследования показали, что существенное количество тепла выделяется при нагреве порошков алюминия, цинка, титана и железа; при нагреве смесей со связующим, наилучшие результаты соответствуют сплаву меди с железом, алюминию и сплаву меди с алюминием. The article presents experimental studies of ultrafine metal powders of aluminum, copper, iron, tungsten, titanium, zinc, nickel, alloys of copper with aluminum, copper with iron and brass. The thermal properties of their mixtures with methyl polyvinyl tetrazole and plasticized propylenglycoldinitrate are described; numerical values of significant characteristics are indicated.The results of the study showed that a significant amount of heat is released when heating aluminum, zinc, titanium and iron powders; when heating mixtures with a binder, the best results correspond to an alloy of copper with iron, aluminum and an alloy of copper with aluminum.

Multiscale modeling of thermal properties of silicene using molecular dynamics

2018 ◽  
Vol 32 (27) ◽  
pp. 1850331 ◽  
Author(s):  
D. K. Das ◽  
Jit Sarkar
Keyword(s):  
Molecular Dynamics ◽  
Thermal Properties ◽  
Multiscale Modeling ◽  
Experimental Studies ◽  
Md Simulations ◽  
Heat Of Fusion ◽  
Sample Sizes ◽  
Different Temperatures ◽  
Pressure Melting ◽  
Non Equilibrium Molecular Dynamics

Silicene sheet is prepared by atomistic multiscale modeling using molecular dynamics (MD) simulations to evaluate thermal properties of silicene at different temperatures and variable sample sizes. In this paper, by MD simulation study, we have estimated coefficient of linear and surface expansion between a temperature range from 318 K to 398 K, specific heat at constant volume and pressure, melting point, heat of fusion and thermal conductivity of silicene at different sample sizes by both equilibrium molecular dynamics (EMD) and non-equilibrium molecular dynamics (NEMD) approaches. The presented multiscale modeling approaches could guide experimental studies to design silicene sheet with required thermal properties for operation under specific conditions.

An Analytic Strategy for Studying Assemblage-Scale Ceramic Variation: A Case Study from Southeast Missouri

1993 ◽  
Vol 58 (3) ◽  
pp. 530-543 ◽  
Author(s):  
Patrice A. Teltser
Keyword(s):  
Thermal Properties ◽  
Experimental Studies ◽  
Simple Classification ◽  
Southeast Missouri ◽  
Analytic Strategy ◽  
Ceramic Assemblages

For ceramic assemblages composed exclusively of sherds, inferences at the scale of artifact are often problematic. Drawing on information provided by experimental studies, observations can be made such that technology and use are expressed at the scale of assemblage. A simple classification is used to describe variation in paste composition for an assemblage of shell-tempered ceramics from southeast Missouri. Using these classes as a set of analytic units, variables reflecting on technology and use are examined. The analytic results suggest that while some coarse-shell ceramics may have been used preferentially for cooking vessels, the distinction between coarse and fine shell is not as straightforward as cooking vs. noncooking, and that coarse-shell pastes were used to manufacture vessels used in a wider range of contexts than fine-shell pastes. Furthermore, not all variation can be understood in terms of the mechanical or thermal properties usually emphasized in experimental studies.

STRUCTURAL, ELECTRONIC, THERMODYNAMIC AND THERMAL PROPERTIES OF ZINC-BLENDE InP, InAs AND THEIR InAsx P1-x TERNARY ALLOYS VIA FIRST PRINCIPLES CALCULATIONS

2013 ◽  
Vol 27 (27) ◽  
pp. 1350166 ◽  
Author(s):  
O. NEMIRI ◽  
S. GHEMID ◽  
Z. CHOUAHDA ◽  
H. MERADJI ◽  
F. EL HAJ HASSAN
Keyword(s):  
Thermal Properties ◽  
Bulk Modulus ◽  
Band Gap ◽  
Lattice Constant ◽  
First Principles ◽  
Density Functional ◽  
Experimental Studies ◽  
Ternary Alloys ◽  
Full Potential ◽  
First Principles Calculations

First-principles calculations are performed to study the structural, electronic, thermodynamic and thermal properties of the InP and InAs bulk materials and InAs x P 1-x ternary alloys using the full potential-linearized augmented plane wave method (FP-LAPW) within the density functional theory (DFT). The dependence of the lattice constant, bulk modulus, band gap, Debye temperature, heat capacity and mixing entropy on the composition x was analyzed. The lattice constant for InAs x P 1-x alloys exhibits a marginal deviation from the Vegard's law. A large deviation of the bulk modulus from linear concentration dependence (LCD) was observed for our alloys. We found that the composition dependence of the energy band gap is almost linear by using the mBJ and EV-GGA approximations. The microscopic origins of the gap bowing were explained and detailed by using the approach of Zunger and co-workers. Furthermore, the calculated phase diagram shows a miscibility gap for these alloys with a high critical temperature. Thermal effects on some macroscopic properties of InAs x P 1-x alloys are predicted using the quasi-harmonic Debye model, in which the phononic effects are considered. This is the first quantitative theoretical prediction of the thermal properties of the InAs x P 1-x alloys, and we still expect the confirmation of experimental studies.

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