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Study of Ultrasonic and Thermal Properties for Heat Transfer Enhancement in Fe 2 O 3 Nanoparticles-Ethylene Glycol Nanofluids Int. J. Thermophys. (IF 0.794) Pub Date : 2021-03-02 Shakti Pratap Singh; A. K. Verma; A. K. Jaiswal; Devraj Singh; R. R. Yadav
In present work, semiconducting iron (III) oxide (Fe2O3) nanoparticles have been synthesized by sol–gel method. X-ray diffraction (XRD), UV–Visible (UV–Vis) absorption spectroscopy and transmission electron microscopy (TEM) have been used for the characterization of the synthesized nanoparticles. Two-step technique was used to formulate stable ethylene glycol (EG) based Fe2O3 nanofluids at room temperature
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Large-Group Proficiency Testing on Calibration of Platinum Resistance Thermometers from − 196 °C to 650 °C Int. J. Thermophys. (IF 0.794) Pub Date : 2021-03-01 Inseok Yang; Young Hee Lee
Proficiency testing on calibration by comparison of platinum resistance thermometers (PRTs) among several calibration laboratories in Korea was conducted. The challenges faced in organizing this proficiency testing were the required wide temperature range (from − 196 °C to 650 °C) and the large number of participants (43). Maintaining the stability of the test items was key to achieving the goal of
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A Three-Dimensional Analysis of Homogeneous and Functionally Graded Thermoelectric Cylinders Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-27 Zhi-He Jin
This paper analyzes a homogeneous thermoelectric (TE) circular cylinder as well as an exponentially graded TE cylinder under three-dimensional (3D) conditions. Analytical solutions of the temperature fields are obtained using an eigenfunction expansion method. The energy conversion efficiencies are determined and the material property gradation and leg geometry effects are examined. For the homogeneous
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CFD Simulation of CO 2 Capture in a Microchannel by Aqueous Mixtures of MEA and [Bmim]BF 4 Modified with TiO 2 Nanoparticles Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-26 M. A. Makarem, M. R. Kiani, M. Farsi, M. R. Rahimpour
In this research, a novel aqueous solvent, i.e., nanoparticle-enhanced ionic liquid (NEIL), is proposed for CO2 capture by mixing of MEA as the base fluid and [Bmim]BF4 ionic liquid and TiO2 nanoparticles as chemical additives. Then, the flow hydrodynamics, mass transfer characteristics, and CO2 absorption performance of the proposed solvent are investigated in a T-shaped microchannel structure by
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A Novel Finite Element Model for Simulating Residual Stress in Laser Melting Deposition Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-25 Yu Zhan, Enda Zhang, Peng Fan, Jiateng Pan, Changsheng Liu, Xiangwei Kong
The geometry of the cladding pass cross section cannot be easily predicted in laser melting deposition. Due to the huge difference between the actual and the predicted cross section, it is difficult to conduct numerical simulations. In this paper, the finite element method (FEM) with thermal–mechanical coupling is performed. A novel cladding pass cross section model, isosceles trapezoid model, is proposed
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Nucleate and Film Boiling Performance of Ethanol-Based Nanofluids on Horizontal Flat Plate: An Experimental Investigation Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-21 Seyed Hadi Golkar, Morteza Khayat, Masoud Zareh
In this paper, the heat transfer characteristics of nanofluid nucleate and film boiling are studied experimentally. For this purpose, Al2O3 and SiO2 ethanol-based nanofluids prepared with three volumetric concentrations of 0.1 %, 0.3 %, and 0.5 %. The boiling experiments were conducted on a circular and polished copper surface with a diameter of 25 mm. The results showed that the addition of nanoparticles
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The Thermal Diffusivity of Glass Sieves: I. Liquid Saturated Frits Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-16 Ulf Hammerschmidt, Muhammad Abid
The thermal diffusivity of evacuated and liquid-saturated borosilicate glass sieves (frits) of porosities between 20 % and 48 % is presented as measured at room temperature. The saturants cover a range in thermal diffusivity from 0.091 mm2·s−1 to 0.143 mm2·s−1. The runs were carried out using a transient hot bridge (THB) measuring instrument of an expanded uncertainty of 5 % to 10 %. The experimental
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Novel Method of Fast Measurement of Thermal Conductivity in Wide Range of Temperatures Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-16 Naftaly Menn
Theoretical aspects and practical realization of a new method of fast measurement of thermal conductivity of coating materials (like deposits on wall and tubes of the boilers using fossil fuel, or high-temperature ceramics and adhesive materials) are presented. The method is based on analytical solution of the problem of unsteady heat transfer from the heated probe with coating to the environmental
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Evaluation of Mass Accommodation Coefficients of Water over a Wide Temperature Range and Determination of Diffusion Coefficient of Water in Nitrogen Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-11 Yongyang Su, Wenliang Wang, Wei Wang, Lihua Zhai, Xiaopan Shen, Jiang Xu, Zhiming Li
Diffusion coefficient of water in nitrogen (Dvg) is a critical thermophysical parameter. However, the widely used empirical parametrizations of Dvg are only applicable in the temperature range from 273 K to 373 K. In the supercooled range, the reported experimental values of Dvg is sparse, and Dvg varies with temperature in a way different from the empirical equations and the recently reported first-principles
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Experimental Study on Thermophysical Properties of Propylene Glycol-Based Graphene Nanofluids Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-11 Fei Dong, Junshen Wan, Yakang Feng, Zhiming Wang, Jie Ni
This study determined the optimal dispersion conditions of nanofluids by orthogonal experiments. Stable graphene/propylene glycol nanofluids are successfully prepared by a "two-step method" using a 60 wt % propylene glycol deionized water solution as the base fluid, and its thermal conductivity and viscosity are evaluated. Additionally, the effects of the graphene mass concentration and nanofluid temperature
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Reference Correlation for the Thermal Conductivity of Xenon from the Triple Point to 606 K and Pressures up to 400 MPa Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-11 Danai Velliadou, Marc J. Assael, Konstantinos D. Antoniadis, Marcia L. Huber
A new wide-ranging correlation for the thermal conductivity of xenon, based on the most recent theoretical calculations and critically evaluated experimental data, is presented. The correlation is designed to be used with a high-accuracy Helmholtz equation of state, and it is valid from the triple-point temperature to 606 K and pressures up to 400 MPa. The estimated expanded uncertainty (at a coverage
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Determination and Modeling of Optimum Insulation Thickness for Thermal Insulation of Buildings in All City Centers of Turkey Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-11 Ahmet Erhan Akan
In this study, research has been carried out in which the optimum insulation thickness for the thermal insulation of buildings in all city centers of Turkey is determined according to life cycle cost analysis. Besides, the total annual net savings of the buildings in all city centers and the payback period of the insulation were concluded according to the determined optimum insulation thickness. In
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Relation of the Electrical Conductivity and the Thermal Conductivity to the Young’s Modulus of Buckypapers Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-11 Bokang Mu, Xin Li, Xin Feng, Yong Li, Chao Ding, Gutian Zhao, Juekuan Yang
Buckypapers (BPs) are porous films of randomly oriented carbon nanotubes (CNTs), and have potential applications in many fields. To get better performance, the properties of BPs are needed to be tuned to meet the demands of various applications. In this paper, the effects of annealing on tuning the Young’s modulus, the electrical conductivity, and the thermal conductivity of BPs were studied. Our results
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Thermal Finite Element Simulation of Dry Block Calibrator Based on Multi-fixed-Point Cells Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-11 Fanchao Zeng, Jianping Sun, Xiang Hu, Chengyu Fu
On-site thermometer calibration by the temperature scale transfer technique based on fixed points can effectively improve the calibration level of thermometers in large-diameter hot water pipes. Calibrations of contact thermometers in large-diameter hot water pipes are often carried out using dry block calibrators. Axial temperature gradients and the drift of reference thermometers are the main sources
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Thermal Performance Optimization of Lightweight Concrete/EPS Layered Composite Building Blocks Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-11 Osman Gencel, Juan José del Coz Díaz, Mucahit Sutcu, Fatih Kocyigit, F. P. Álvarez Rabanal, Mar Alonso-Martínez, Gonzalo Martinez Barrera
The aim of this paper is to study and optimize the thermal performance of new lightweight and insulating composite blocks (CBlocks). These CBlocks are made up of a central expanded polystyrene (EPS) layer and two lightweight concrete layers with cavities. The aggregate of the lightweight concrete is pumice. A complete corner wall composed of six composite blocks and a specific corner block is numerically
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Magnetic Properties and Compensation Temperature in Tri-layer Graphyne-Like Structure: Monte Carlo Simulations Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-08 Z. Fadil, N. Maaouni, A. Mhirech, B. Kabouchi, L. Bahmad, W. Ousi Benomar
In this paper, we study the magnetic properties of a tri-layer graphyne-like structure using Blume-Capel Ising model. The studied system is composed by a mixed spins σ = ± 5/2, ± 3/2 and ± 1/2 (in the plane B) and S = ± 2, ± 1 and 0 (in the plane A). The study is performed through Monte Carlo simulations under the Metropolis algorithm. Besides, we examine the effects of the exchange coupling interactions
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Molecular Dynamics Simulations of the Effects of a Nanoparticle Surface Adsorption Layer on the Thermal Conductivity of a Cu–Ar Nanofluid Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-08 Liang Zhang, Linchao Tian, Anlong Zhang, Yuyan Jing, Pingping Qu
Nanofluids formed by adding a small volume fraction of solid nanoparticles to the conventional fluid can greatly enhance the thermal transport performance of the conventional fluid. This study reveals the mechanism of thermal conductivity by studying the microscopic effect of nanoparticles in a Cu–Ar nanofluid on the base fluid. Due to the presence of a trapped, adsorbed Ar layer on the surface of
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Density Measurements of Two Liquefied Biomethane-Like Mixtures over the Temperature Range from (100 to 180) K at Pressures up to 9.0 MPa Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-03 Giuseppe Cavuoto, Nils von Preetzmann, Philipp Eckmann, Jianrong Li, Adriaan M. H. van der Veen, Reiner Kleinrahm, Markus Richter
Densities of two synthetic biomethane-like mixtures were measured in the homogeneous liquid phase and the supercritical region using a low-temperature single-sinker magnetic-suspension densimeter. Both mixtures consist of methane, nitrogen, hydrogen and oxygen, whereas the second mixture additionally contains carbon dioxide. For the first mixture, four isotherms from (100 to 160) K were studied over
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An Investigation on Thermophysical and Dielectric Properties of Ammonium Dihydrogen Phosphate Single Crystal for Opto-electronic Device Applications Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-02 J. Thirupathy
Ammonium dihydrogen phosphate (ADP) crystal utilizes several applications such as Q-switching, electro-optical, and second harmonic generation in nonlinear optics. In the present article, a good-quality single crystal of ADP was grown via Sankaranarayanan–Ramasamy (SR) method for the dimension of 120 mm in length and 12 mm in diameter. The grown ADP crystal is used for diverse characterizations like
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Calibration and Uncertainty Estimation for Water Content Measurement in Solids Int. J. Thermophys. (IF 0.794) Pub Date : 2021-02-02 Rudolf Aro, Mohamed Wajdi Ben Ayoub, Ivo Leito, Éric Georgin, Benoit Savanier
In the field of water content measurement, the calibration of coulometric methods (e.g., coulometric Karl Fischer titration or evolved water vapor analysis) is often overlooked. However, as coulometric water content measurement methods are used to calibrate secondary methods, their results must be obtained with the highest degree of confidence. The utility of calibrating such instruments has been recently
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The Thermal Conductivity of Glass Sieves: II. Liquid and Gas-Saturated Frits Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-27 Ulf Hammerschmidt, Muhammad Abid
The thermal conductivity of liquid and gas-saturated glass sieves (frits) of porosities between 20 and 48 % is presented as measured at room temperature and ambient pressure. The saturating fluids cover a range in thermal conductivity from 0.018 W⋅m−1⋅K−1 to 0.598 W⋅m−1⋅K−1. The experimental results are fitted to a simple two-dimensional composite model for the heat transfer in porous media. The runs
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Solid–Liquid Equilibria of Binary Systems Containing Amines: Experimental Data and Prediction with DISQUAC and UNIFAC Models Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-22 Fayrouz Djellouli, Abdallah Dahmani, Aicha Hassani
Group contribution models can be used to predict the thermodynamic properties. The basic data used to determine the interaction parameters are VLE, HE and infinite dilution activity coefficient data. However in the absence of the required data, SLE measurements of eutectic systems are of great interest for fitting interaction parameters of group contribution methods. The knowledge of solid–liquid equilibria
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Distilled Water-Based AlN + ZnO Binary Hybrid Nanofluid Utilization in a Heat Pipe and Investigation of Its Effects on Performance Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-21 Erdem Çiftçi
The preparation and utilization of hybrid nanofluids in thermal systems have become popular nowadays owing to their improved thermophysical properties. Although a nanofluid suspension increases the performance of the thermal system, hybrid nanofluids improve the heat transfer performance more by removing the disadvantages of each component. The aqueous hybrid nanofluids consisting of AlN and ZnO nanoparticles
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An Experimental Investigation on Rheological and Heat Transfer Performance of Hybrid Nanolubricant and Its Effect on the Vibration and Noise Characteristics of an Automotive Spark-Ignition Engine Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-20 Bhavin K. Bharath, V. Arul Mozhi Selvan
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Measurement and Uncertainty Assessment of the Thermal Conductivity and Diffusivity of Silica Glass using Step-Wise Transient Method Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-19 Svetozár Malinarič, Ahmed Elkholy
This paper investigates the accuracy of the step-wise transient (SWT) method and proposes a modified model that embodies the real-world experimental setup. The presented model incorporates all the imperfections of the thermocouple and heater, such as the thermal capacity and thermal contact resistance with the specimen. The viability of the proposed hypothesis was confirmed via the experiment simulation
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Upgrading of the Performance of an Air-to-Air Heat Exchanger Using Graphene/Water Nanofluid Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-19 Adnan Sözen, Çağdaş Filiz, İpek Aytaç, Kerim Martin, Hafiz Muhammad Ali, Kurtuluş Boran, Yaşar Yetişken
The aim of this study is to improve the thermal performance of air-to-air heat recovery units, containing heat pipes by using graphene/water nanofluid as a working fluid. The experimental set up of this work consists of two air ducts. To study the effect of the airflow rate and the temperature on the performance of the heat recovery unit, different values of airflow rates and temperatures are used
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Model for Predicting the Thermal Conductivity of Concrete Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-19 Xiaochun Lu, Fuguo Tong, Gang Liu, Jinkun Guan
Thermal conductivity of concrete greatly influences the heat transfer of buildings and affected by many factors. This paper presents a prediction model for thermal conductivity of concrete by adopting the theory of Wiener bounds and considering concrete to have four components (water, air, aggregate, and cement mortar). The proposed model considers the combined effects of porosity, water saturation
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Characterization of Solar Absorber Coated by Reduced Graphene Oxide Polymer Composite on Metal Sheets Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-18 S. M. Zafar Iqbal, Karwan Wasman Qadir, Hewa Y. Abdullah, Ali M. Dastgheib, Muhammad Mehran Bashir
This paper presents the characterization of solar heat absorber coatings on metal sheets using reduced graphene oxide polymer composites. The reduced graphene oxide (rGO) polymer composite material was evenly coated by the silk-screen method on three types of metal sheets. The thickness of the coated sheet samples was 0.25 mm which were exposed under solar radiation and the variations in temperatures
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Modeling of the Interfacial Behavior of Carbon Dioxide + Methyl Myristate, Carbon Dioxide + Palmitate, and Carbon Dioxide + Methyl Myristate + Methyl Palmitate Mixtures Using CPA-EOS and Gradient Theory Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-18 Ariel Hernández, Damelys Zabala
This work presents the vapor–liquid equilibrium and the interfacial behavior modeling of binary and ternary CO\(_2\) + ester mixtures, with the cubic plus association equation of state (CPA-EOS) combined with the density gradient theory. The binary mixtures, CO\(_2\) + methyl myristate and CO\(_2\) + methyl palmitate, were studied at temperatures from 313.15 K to 333.15 K, considering the ester molecules
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A CFD Study of [C2mim][CH3SO3]/Al 2 O 3 Ionanofluid Flow and Heat Transfer in Grooved Tubes Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-18 Mehrdad Mesgarpour, Mehdi Bahiraei, Somchai Wongwises, Amin Jodat, Omid Mahian
The present article deals with the computational fluid dynamics (CFD) investigation of flow and heat transfer of a [C2mim][CH3SO3]/Al2O3 ionanofluid in one conventional tube and two different grooved tubes. The flow is considered to be single-phase and laminar (500 < Re < 2000), and the range of nanoparticle concentration is between 0.05 and 2 %. For properties of the ionanofluid, experimental data
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Insights on the Heating Characteristics of Mn and Co Ferrites Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-14 J. Shebha Anandhi, R. Justin Joseyphus
The heating characteristics of ferrite nanoparticles are inconsistent due to various factors that affect the optimum particle size required for maximum power dissipation. The heating mechanism of Fe3O4, MnFe2O4, and Co0.5Fe2.5O4 in the size range 10–40 nm with varying particle size distribution is correlated with the effective specific absorption rate (ESAR). The effective magnetic anisotropy of the
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Boundary Element Modeling for Simulation and Optimization of Three-Temperature Anisotropic Micropolar Magneto-thermoviscoelastic Problems in Porous Smart Structures Using NURBS and Genetic Algorithm Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-13 M. A. Fahmy, S. Shaw, S. Mondal, A. E. Abouelregal, Kh. Lotfy, I. A. Kudinov, A. H. Soliman
The main objective of the present paper is to propose a new boundary element modeling technique for simulation and optimization of three-temperature micropolar magneto-thermoviscoelastic problems in anisotropic porous smart structures, where we implemented the genetic algorithm (GA), as a method of optimization based on the free form deformation (FFD) methodology to improve the performance of our proposed
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Investigation of Thermal and Strength Properties of Composite Panels Fabricated with Plaster of Paris for Insulation in Buildings Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-12 Ubong Williams Robert, Sunday Edet Etuk, Okechukwu Ebuka Agbasi, Sylvester Andrew Ekong, Zaidoon Taha Abdulrazzaq, Armstrong Udochukwu Anonaba
This study was designed to assess the possibility of tailoring waste papers and wood dust into composite materials with plaster of Paris (P.O.P) and also determine the suitability of using the developed composites as ceiling panels in building construction. Assorted un-used papers collected as waste materials were processed into waste paper ash (WPA) which was then after utilized like untreated wood
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Characterisation of the NPL Thermal Conductivity Reference Material Inconel 600 Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-12 Jiyu Wu, Roger Morrell, Jamie Clark, Lindsay Chapman
Due to the depletion of the thermal conductivity reference materials, the National Physical Laboratory (NPL) has certified a new thermal conductivity reference material, NPL code 2I09 that is based on Inconel 600. This batch of material has been thermally and electrically characterised over the temperature range 100 °C to 500 °C. The primary thermal conductivity measurements used to generate the certified
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Inverse Identification of Temperature-Dependent Thermal Conductivity for Charring Ablators Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-12 Xiang-Yang Wang, Na Liu, Rui Zhao, Yong-Le Nian, Wen-Long Cheng
Estimation of thermal conductivity of charring composite is a key issue for both design and optimization of an ablative thermal protection system. This paper presents a method for predicting temperature-dependent thermal conductivity of charring ablator using genetic algorithm and cubic spline interpolation, and a special ablative material composed of phenolic resin, glass fibers and quartz fibers
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Constitutive Equations Developed for Modeling of Heat Conduction in Bio-tissues: A Review Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-12 Chen-yang Lyu, Ren-jun Zhan
In order to further study the mechanism of heat conduction in bio-tissues, so as to provide a solid theoretical basis for the research of related fields, this paper summarizes in detail the theoretical models used by scholars from various countries to analyze the heat conduction process in the photothermal effect of laser-bio-tissues for many years. The rationality of the theoretical model largely
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ANN Modeling of Thermal Conductivity and Viscosity of MXene-Based Aqueous IoNanofluid Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-11 Naman Parashar, Navid Aslfattahi, Syed Mohd Yahya, R. Saidur
Research shows that due to enhanced properties IoNanofluids have the potential of being used as heat transfer fluids (HTFs). A significant amount of experimental work has been done to determine the thermophysical and rheological properties of IoNanofluids; however, the number of intelligent models is still limited. In this work, we have experimentally determined the thermal conductivity and viscosity
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Intercomparison of Thermal Conductivity Measurements on a Nanoporous Organic Aerogel Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-07 Hans-Peter Ebert, Stephan Braxmeier, Gudrun Reichenauer, Frank Hemberger, Fabian Lied, Dirk Weinrich, Marc Fricke
Due to their special combination of nanostructure and high porosity, aerogels are key materials for high performance thermal insulation. However, measuring reliable thermal conductivity values, which are essential for material’s optimization and as product parameter, is a challenging task in the case of aerogels. Experimentally derived thermal conductivity values for aerogels are so far more or less
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Mechanical Properties of Clonal Eucalyptus Wood Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-07 Mahyoub Amer, Bousselham Kabouchi, Mohamed Rahouti, Abderrahim Famiri, Abdelwahed Fidah, Salah El Alami
The mechanical properties of wood are important factors to demonstrate its suitability in construction and crafts applications. The aim of this study is to evaluate the mechanical parameters for two clones of eucalyptus wood (E. grandis; E. camaldulensis). At 12 % moisture content, axial compression, axial tension, four-points bending and elasticity dynamic modulus resulting from the propagation of
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Experimental Thermal Conductivity of Alumina Nanoparticles in Water With and Without Sonication Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-07 Sandra Corasaniti, Gianluigi Bovesecchi, Fabio Gori
Experimental thermal conductivity of alumina nanoparticles in water is measured with the transient thermal probe, in the presence of sonication (i.e., with ultrasounds), or not. We investigate two types of alumina particles, with the diameter equal to 7 nm and 50 nm. The experimental results, with and without sonication, show that the effective thermal conductivity is greater for the alumina nanoparticle
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Thermal Investigation of Direct Vapor Transport (DVT) Grown Quaternary Cu 2 ZnSnS 4 Single Crystals Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-07 Anilkumar B. Hirpara, Sunil H. Chaki, Ankurkumar J. Khimani, Rohitkumar M. Kannaujiya, M. P. Deshpande
The single crystals of Cu2ZnSnS4 (CZTS) are grown by direct vapor transport technique. The analysis of X-ray from energy dispersion confirmed that the as-grown single crystals are near stoichiometric. The analysis of the as-grown CZTS single crystals by diffraction of X-ray (XRD) showed the crystal possess tetragonal structure having lattice parameters; a = b = 5.42 Å, c = 10.84 Å and α = β = γ = 90º
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Evaluation of the Cooling Potential of Earth Air Heat Exchanger Using Concrete Pipes Int. J. Thermophys. (IF 0.794) Pub Date : 2021-01-05 Baljit Singh, A. K. Asati, Rakesh Kumar
An earth air heat exchanger (EAHE) has advantages of its simplicity, easy implementation and low operating cost. The EAHE system is found less expensive for cooling and heating of buildings in severe climates. In this research paper, efforts have been made to analyze the accomplishment of a low-cost cooling system of outdoor air for the hot-dry & hot-humid climate. The effect of velocity, length and
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Speeds of Sound in n -Hexane and n -Heptane at Temperatures from (233.33 to 353.21) K and Pressures up to 20 MPa Int. J. Thermophys. (IF 0.794) Pub Date : 2020-12-28 Christian W. Scholz, Markus Richter
The speed of sound in high-purity n-hexane and n-heptane was experimentally studied utilizing the double-path length pulse-echo technique. Measurements with each alkane were carried out at temperatures from (233 to 353) K with pressures up to 20 MPa. Considering the uncertainty contributions from temperature, pressure, path-length calibration, pulse timing and sample purity, the relative expanded combined
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Re-investigation of the Normal Spectral Emissivity at 684.5 nm of Solid and Liquid Molybdenum Int. J. Thermophys. (IF 0.794) Pub Date : 2020-12-28 Alexander Eber, Peter Pichler, Gernot Pottlacher
In this work, we present normal spectral emissivity data of solid and liquid molybdenum at a wavelength of 684.5 nm. The presented results are novel measurements on molybdenum, a material, which was already measured 15 years ago by our group. The present results indicate a lower emissivity in the liquid phase. The novel measurements were done within the European Metrology Programme for Innovation and
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Surface Tension and Density of Liquid Hot Work Tool Steel W360 by voestalpine BÖHLER Edelstahl GmbH & Co KG Measured with an Electromagnetic Levitation Apparatus Int. J. Thermophys. (IF 0.794) Pub Date : 2020-12-28 Thomas Leitner, Anna Werkovits, Siegfried Kleber, Gernot Pottlacher
W360 is a hot work tool steel produced by voestalpine BÖHLER Edelstahl GmbH & Co KG, a special steel producer located in Styria, Austria. Surface tension and density of liquid W360 were studied as a function of temperature in a non-contact, containerless fashion using the oscillating drop method inside an electromagnetic levitation setup. For both, surface tension and density, a linear model was adapted
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Effusion of Gas Through a Small Hole Int. J. Thermophys. (IF 0.794) Pub Date : 2020-11-20 Mohammad Khorrami
A vessel containing a classical non-relativistic ideal gas is studied, which has a small hole. Gas effuses through this hole, but the hole is so tiny that the gas inside the vessel remains homogeneous. The density and the temperature of the gas inside the vessel are obtained as functions of time.
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Hybrid Thermal Treatment Based on Microwaves and Heating Resistance for Composite Materials Int. J. Thermophys. (IF 0.794) Pub Date : 2020-11-20 Cristian Jimenez, Ivan Amaya, Rodrigo Correa
Nowadays, it is well known that volumetric heating through microwaves inhibits certain surface properties from being achieved. Similarly, exclusively heating via thermal radiation is neither deep nor homogeneous enough for short periods of time. But combining both approaches can alleviate such issues. In fact, this kind of hybrid heating has been used for many years in real processes for thermal treatment
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Modeling Vapor–Liquid Equilibria and Surface Tension of Carboxylic Acids + Water Mixtures Using Peng–Robinson Equation of State and Gradient Theory Int. J. Thermophys. (IF 0.794) Pub Date : 2020-11-16 Ariel Hernández
This work has been dedicated to modeling the vapor–liquid equilibria and surface tension of carboxylic acids + water mixtures at different temperatures. The Peng–Robinson equation of state with modified Huron–Vidal + Wilson mixing rule correctly models the vapor pressure and vapor mole fraction of these mixtures. The modified Huron–Vidal mixing rule was better than quadratic mixing rule to model the
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Heat Transfer Capability of Ionanofluids for Heat Transfer Applications Int. J. Thermophys. (IF 0.794) Pub Date : 2020-11-11 Gabriela Huminic, Angel Huminic
Ionanofluids are mixtures of ionic liquid and solid particles with enhanced thermo-physical properties. Using the properties of these ionanofluids (thermal conductivity, dynamic viscosity, specific heat, and density), a comprehensive analysis concerning their heat transfer capability was performed. Two nanomaterials, silicon carbide (SiC) and graphene dispersed in 1-hexyl-3-methylimidazolium tetrafluoroborate
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Marangoni Forced Convective Flow of Second Grade Fluid with Irreversibility Analysis and Chemical Reaction Int. J. Thermophys. (IF 0.794) Pub Date : 2020-11-04 T. Hayat, Sohail A. Khan, Ahmed Alsaedi, Habib M. Fardoun
Here we analyze the Marangoni convective magnetohydrodynamic flow of second grade liquid. Heat transportation is discussed through Joule heating and viscous dissipation. Characteristics of thermo-diffusion and diffusion-thermo are also considered. Gibbs–Marangoni effect is the solutal transfer along the boundary between liquids as a result of gradient of surface tension. Furthermore Bénard–Marangoni
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Methods for the Determination of Nanofluid Optical Properties: A Review Int. J. Thermophys. (IF 0.794) Pub Date : 2020-11-02 Hossain Md Fazle Rabbi, Ahmet Z. Sahin, Bekir S. Yilbas, Abdullah Al-Sharafi
Methods for the determination of the optical properties of both conventional and hybrid nanofluids are presented. The optical properties considered included the extinction coefficient, absorptance, transmittance, and reflectivity. Experimental, theoretical, and numerical approaches for the evaluation of the optical properties are reviewed. The effects of nanoparticle concentration, size, and shape
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Approximate Analytical Solutions of the Klein–Gordon Equation with Generalized Morse Potential Int. J. Thermophys. (IF 0.794) Pub Date : 2020-11-02 A. N. Ikot, U. S. Okorie, G. J. Rampho, P. O. Amadi
In this study, the Klein–Gordon equation for the newly proposed generalized Morse potential (GMP) was solved using the newly proposed Nikiforov–Uvarov-functional analysis (NUFA) method for solving central potentials. The analytical expressions of Eigen solutions for GMP were obtained in closed form. The effects of the GMP parameters on the energy eigenvalues have been discussed. The wave function and
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Thermal Conductivity and Viscosity Correlations in Different Kinds of Aqueous Surfactant Solutions at Atmospheric Pressure as a Function of Temperature Int. J. Thermophys. (IF 0.794) Pub Date : 2020-10-31 Aycan Altun, Osman Nuri Şara
Surfactants with a wide range of uses are often preferred to reduce particle aggregation in nanofluid and provide stability. However, added surfactants affect the properties of not only nanofluids but also base fluids. In this study, binary mixtures were prepared by using water and three different surfactants, namely, SDS, Tween 80, and NP 10, in four different concentrations of 0.2 % to 0.8 % by weight
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Investigation of Energy Saving Potential in Buildings Using Novel Developed Lightweight Concrete Int. J. Thermophys. (IF 0.794) Pub Date : 2020-10-27 Ahmet Erhan Akan, Fatih Ünal, Fatih Koçyiğit
In this study, three different composite materials were produced from mixtures of natural and waste materials in different proportions. The produced composites were used to determine the insulation thickness of exterior walls of buildings located in 12 provinces selected from the four different climate zones of Turkey. The selection of provinces was made according to Turkish standard TS 825. The produced
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Thermoelectric and Piezoelectric Properties in Half-Heusler Compounds TaXSn (X = Co, Rh and Ir) Based on Ab Initio Calculations Int. J. Thermophys. (IF 0.794) Pub Date : 2020-10-27 Z. A. A. R. Almaghbash, O. Arbouche, A. Dahani, A. Cherifi, M. Belabbas, A. Zenati, H. Mebarki, A. Hussain
In this paper, we report a theoretical study of the structural, electronic, thermoelectric and piezoelectric properties of TaXSn (X = Co, Rh and Ir) half-Heusler compounds crystallizing with cubic MgAgAs-type structure. We have made a quantitative evaluation of thermoelectric figure of merit (ZT) and the electromechanical coupling coefficient (k14) of these compounds. Accordingly, we intend to combine
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Optimized Design for a Device to Measure Thermal Contact Conductance During Friction Stir Welding Int. J. Thermophys. (IF 0.794) Pub Date : 2020-10-27 Daniel Ellis, Matthew Goodson, Michael Miles, Troy Munro
Friction stir welding (FSW) is a solid-state welding process that is finding increasing use in a variety of industries, owing to its ability to create high-quality welds with less heat input than fusion welding. While the modeling of FSW has been an active effort for at least 15 years, two input parameters, namely the friction coefficient and the heat transfer coefficient, are still adjustable quantities
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Temperature-Dependent Emissivity Models of Aeronautical Alloy DD6 and Modified Function for Emissivity Computation with Different Roughness Int. J. Thermophys. (IF 0.794) Pub Date : 2020-10-27 Yanfen Xu, Kaihua Zhang, Kun Yu, Yanlei Liu, Yufang Liu
In this study, the spectral emissivity of aeronautical alloy DD6 at eight temperatures (473 K, 523 K, 573 K, 623 K, 673 K, 723 K, 773 K and 823 K) over the spectral range from 3 μm to 20 μm is systematically studied under argon condition. The multi-temperature calibration method is adopted to accurately obtain the FTIR spectrometer response, and then the improved method that eliminates the disturbances
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Effect of Impedance Boundary on the Reflection of Plane Waves in Fraction-Order Thermoelasticity in an Initially Stressed Rotating Half-Space with a Magnetic Field Int. J. Thermophys. (IF 0.794) Pub Date : 2020-10-26 Anand Kumar Yadav
In this research article, the propagation of the plane waves in an initially stressed rotating magneto-thermoelastic solid half-space in the context of fractional-order derivative thermoelasticity is studied. The governing equations in the x–z plane are formulated and solved to obtain a cubic velocity equation that indicates the existence of three coupled plane waves. A reflection phenomenon for the
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Thermal Conductivity of Supercritical CO 2 -Saturated Coal Int. J. Thermophys. (IF 0.794) Pub Date : 2020-10-26 Asbat E. Ramazanova, Ilmutdin M. Abdulagatov
The present study reports the effective thermal conductivity (ETC) of supercritical (SC) CO2-saturated black coal sample at temperatures from (304.15 to 323.15) K and pressures up to 20 MPa using a steady-state guarded parallel-plate method. The expanded uncertainty of thermal conductivity, pressure, and temperature measurements at the 95 % confidence level with a coverage factor of k = 2 was estimated
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Determination and Correlation of Solubilities of Benzoic Acid, Salicylic Acid, Resorcinol and Hydroquinone in Water and in 1-Octanol at Temperatures from 297.25 K to 334.45 K Int. J. Thermophys. (IF 0.794) Pub Date : 2020-10-24 Boucif Belhachemi, Hamdi Makhlouf, Mohammed Habib Belhachemi
The solubilities of benzoic acid, salicylic acid, resorcinol and hydroquinone in water and in 1-octanol were measured by the dynamic method which is also called the synthetic method from 297.25 K to 334.45 K. Using differential scanning calorimetry (DSC Q2000 and SDT Q600), the melting temperature and the enthalpy of fusion of these solutes were determined. The obtained results show that the solubility
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