Experimental and Theoretical Study of Heat Transport Parameters of Plasters Containing Pozzolanic Admixtures

2016 ◽  
Vol 675-676 ◽  
pp. 569-572
Author(s):  
Lukáš Fiala ◽  
Monika Čáchová ◽  
Eva Vejmelková ◽  
Robert Černý
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Moisture Content ◽  
Building Materials ◽  
Theoretical Study ◽  
Calculated Data ◽  
Pulse Method ◽  
Shape Effect ◽  
Transport Parameters ◽  
Materials Properties

Measurements of basic materials properties of building materials with pozzolanic waste admixture originated from grinding of thermally insulating bricks were performed by means of pycnometry method. Besides, the thermal conductivity dependence on the moisture content measurements were carried out by using a non-stationary pulse method. Obtained data were subsequently analyzed by simple Wiener’s bounds and sophisticated homogenization formula taking into account the shape of ellipsoidal pore inclusions. Validity of applied homogenization models were assessed by comparison of the measured and the calculated data. On the basis of experimental data and homogenization analysis, the shape effect on the thermal conductivity is discussed.

Experimental Analysis of Thermal Conductivity for Building Materials Depending on Moisture Content

2012 ◽  
Vol 33 (8-9) ◽  
pp. 1674-1685 ◽  
Author(s):  
M. Dell’Isola ◽  
F. R. d’Ambrosio Alfano ◽  
G. Giovinco ◽  
E. Ianniello
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Experimental Analysis ◽  
Building Materials

Energetic and Exergetic Analysis of the Clay Bricks Drying in an Industrial Tunnel Dryer

2016 ◽  
Vol 369 ◽  
pp. 104-109 ◽  
Author(s):  
G.S. Almeida ◽  
F.V.S. Tavares ◽  
W.M.P.B. Lima ◽  
A.G. Barbosa de Lima
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Moisture Content ◽  
Theoretical Study ◽  
Clay Bricks ◽  
Tunnel Dryer ◽  
Energy And Exergy ◽  
Exergetic Analysis ◽  
Good Agreement ◽  
Hollow Bricks

The purpose of this paper is to present a theoretical study of industrial hollow bricks drying in across flow tunnel dryer. The theoretical model is based on the 1st and 2nd laws of Thermodynamic applied to the system. To validate the methodology, numerical and experimental data of the moisture content of the brick during the drying in an industrial scale are compared and a good agreement was obtained. Results of moisture content and temperature of the product and air, and energy and exergy efficiencies are presented and analysed.

scholarly journals Thermal Conductivity of Building Materials in Iraq

2021 ◽  
Vol 28 (4) ◽  
pp. 37-49
Author(s):  
Madgeed A. Al-Doury ◽  
Atif Ali Hasan ◽  
Raheem Kadhim Mohammed ◽  
Riyadh H. Al-Jawad
Keyword(s):  
Thermal Conductivity ◽  
Thermal Performance ◽  
Air Conditioning ◽  
Building Materials ◽  
Thermal Loads ◽  
Insulating Materials ◽  
Materials Properties ◽  
Wire Method ◽  
Air Conditioning Systems ◽  
The Relationship

Thermophysical Properties of Building Materials are Considered to have high importance in predicting building thermal performance, calculating thermal loads inside building, and optimizing the use of a building and insulating materials. Due to the lack of measurements of local building materials properties, designers and air- conditioning engineers have no choice but to use the published foreign data, which probably leads to inaccurate predictions of thermal loads and may give a false thermal performance. At the same time, it leads to an over-designed capacity of air- conditioning systems that lead to increased energy consumption in the building. Thus, it is clear that it was important to conduct this research to evaluate the thermal conductivity and thermal resistance of Iraqi building materials. The number of the local building materials were listed, and specimens were collected from their sites, factories, and suppliers such as bricks, stones, concrete products, gypsum, etc. Those samples were dimensioned to the specific size required when a measurement was conducted by the Hot Wire method. All measurements were carried out at room temperature. The relationship between thermal conductivity, density, moisture content, and pressure for a number of materials was Studied. A comparison between the measurements of the Iraqi building materials and results published in the ASHRAE, CIBS Guide, Australian Specifications, and Jordanian Specifications was made. However, the availability of such data is important for the climatic design of buildings, thermal load calculations for air- conditioning, and choosing the insulating materials.

scholarly journals Polymer waste as a combustible additive for wall ceramics production

2019 ◽  
Vol 91 ◽  
pp. 04007 ◽  
Author(s):  
Kseniya Perovskaya ◽  
Daria Petrina ◽  
Evgeniy Pikalov ◽  
Oleg Selivanov
Keyword(s):  
Thermal Conductivity ◽  
Building Materials ◽  
Climatic Conditions ◽  
Liquid Phase Sintering ◽  
Thermal Engineering ◽  
Charge Composition ◽  
Vitreous Phase ◽  
Polymer Waste ◽  
Materials Properties ◽  
Engineering Standards

The research presents the experimental results devoted to the charge composition development for the production of wall ceramic products, based on low plasticity clay using additives. One of the additives is polymer waste in the amount of 15 wt. %, in particular it is unplasticized polyvinyl chloride used as a combustible additive for increasing ceramics porosity thus decreasing its density and consequently the load on the basement when the walls are constructed. Besides it decreases thermal conductivity and improves energy efficiency of developed wall ceramics application. Boric acid is a second additive used as a fuse thus reducing the temperature of ceramics liquid-phase sintering and forming a vitreous phase, which increases the strength characteristics and reduces water absorption, and therefore increases the product frost resistance. However the vitreous phase amount is insignificant and the products still are characterized by porosity sufficient for density and thermal conductivity reduction up to the level of conditionally effective thermal performance. Thus the application of the developed wall ceramics facilitate the production of energy effective products, which can be used for multi-layers walls construction providing modern thermal engineering standards and rational consumption of building materials. Herewith the developed materials properties correspond to the requirements of solid ceramic bricks used in Russian climatic conditions and help to combine the functions of bearing, heat-insulating and partly facing layers to a certain extend thus expanding their application.

scholarly journals Moisture dependent thermal properties of selected vegetables in Akwa Ibom State, Nigeria

2019 ◽  
Vol 65 (No. 2) ◽  
pp. 56-62
Author(s):  
Olugbenga Abiola Fakayode ◽  
Olayemi Olubunmi Ojoawo
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Linear Regression ◽  
Moisture Content ◽  
Specific Heat ◽  
Regression Equations ◽  
Content Variation

The thermal properties of some selected vegetables in Akwa Ibom State, Nigeria were investigated. The specific heat, thermal conductivity and thermal diffusivity for the five selected vegetables (Afang, Nkong, Atama, Editan and Nton) were determined and the moisture content variation was investigated. The specific heat values ranged from 2,348–4,580 J·kg<sup>–1</sup>·K<sup>–1</sup>, while the thermal conductivity values ranged from 0.00368–0.489 and the thermal diffusivity values ranged from 1.03 × 10<sup>–7</sup>–1.99 × 10<sup>–7</sup> m<sup>2</sup>·s<sup>–1</sup>. Nton had the highest specific heat and thermal conductivity, while Editan had the highest diffusivity. An increase in the moisture content increased the specific heat, thermal conductivity and diffusivity of the vegetables and the relationships were found to be linear. Regression equations for the thermal properties were established as a function of the product’s moisture content with the experimental data from this study. The thermal properties of the vegetables varied linearly with the moisture content and there were significant differences in the thermal properties of the selected vegetables.

Moisture content influence on the thermal conductivity of insulating building materials made from date palm fibers mesh

2017 ◽  
Vol 148 ◽  
pp. 811-823 ◽  
Author(s):  
Lahcen Boukhattem ◽  
Mustapha Boumhaout ◽  
Hassan Hamdi ◽  
Brahim Benhamou ◽  
Fatima Ait Nouh
Keyword(s):  
Thermal Conductivity ◽  
Moisture Content ◽  
Building Materials ◽  
Date Palm ◽  
Date Palm Fibers

scholarly journals ELECTROROTATION OF COLLOIDAL SUSPENSIONS

2003 ◽  
Vol 17 (01n02) ◽  
pp. 221-225 ◽  
Author(s):  
J. P. HUANG ◽  
K. W. YU ◽  
G. Q. GU
Keyword(s):  
Experimental Data ◽  
Cell Shape ◽  
Theoretical Study ◽  
Colloidal Suspensions ◽  
Shape Effect ◽  
Oblate Spheroidal ◽  
Theoretical Predictions ◽  
Analytic Expressions ◽  
Particle Shape Effect ◽  
Good Agreement

We investigate the pressure effect on the eletrorotation (ER) spectrum of living cell suspensions by considering the particle shape effect. Based upon the spectral representation theory, we consider coated oblate spheroidal particles and present a theoretical study of ER spectrum. Analytic expressions for the characteristic frequency as well as the dispersion strength can be obtained, thus simplifying the fitting of experimental data. From the theoretical analysis, we find that the cell shape, coating as well as material parameters can change the ER spectrum. We demonstrate good agreement between our theoretical predictions and experimental data on human erythrocytes suspensions.

Thermoelectric Properties of PbSr(Se,Te)-Based Low Dimensional Structures

2000 ◽  
Vol 626 ◽  
Author(s):  
Harald Beyer ◽  
Joachim Nurnus ◽  
Harald Böttner ◽  
Armin Lambrecht ◽  
Lothar Schmitt ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Evaluation Method ◽  
Interband Transition ◽  
Multiple Quantum Well ◽  
Calculated Data ◽  
Multiple Quantum ◽  
Ir Transmission ◽  
Low Dimensional

ABSTRACTThermoelectric properties of low dimensional structures based on PbTe/PbSrTe-multiple quantum-well (MQW)-structures with regard to the structural dimensions, doping profiles and levels are presented. Interband transition energies and barrier band-gap are determined from IR-transmission spectra and compared with Kronig-Penney calculations. The influence of the data evaluation method to obtain the 2D power factor will be discussed. The thermoelectrical data of our layers show a more modest enhancement in the power factor σS2 compared with former publications and are in good agreement with calculated data from Broido et al. [5]. The maximum allowed doping level for modulation doped MQW structures is determined. Thermal conductivity measurements show that a ZT enhancement can be achieved by reducing the thermal conductivity due to interface scattering. Additionally promising lead chalcogenide based superlattices for an increased 3D figure of merit are presented.

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