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The electrical output of solar absorbers like monocrystalline photovoltaic (PV) panels besides the solar irradiance, heavily rely on the operating temperature within the environment. This work investigates an innovative cooling technique to mitigate the detrimental impact of temperature rise on PV panel performance, especially in a temperate region. Nanocoolants have higher thermal conductivity than conventional fluid, hence the effect of its good thermal properties was investigated to observe its influence on the electrical performance of the PV panels. The work involved numerical analysis using the commercial code ANSYS. The Multiphysics approach begins with the steady state analysis and then CFD to observe the thermal flow behaviours of the different components making the panels. The simulation considered three different PV arrangements, the uncooled, the nano-cooled and the water-cooled panels. The panel's surface was exposed to solar irradiance of 650 W/m2 and the operating temperature of 40°. The result found that Al2O3-water nanofluid as a cooling agent by spraying on the solar panel module at the velocity of 0.01m/s can decrease the temperature of the solar panel from 73.85 °C to 35.95 °C. Hence utilization of Nanocoolant for cooling of PV has a good potential in electrical performance enhancement. [ABSTRACT FROM AUTHOR]

The research work is investigating of sintering behavior of ZrO2−TiO2−Al2O3 Ternary system, the composite was prepared by precipitation of hydroxides from their water soluble salts followed by calcinations and sintering, the sintering behavior studied in 1:1:1 mole ratio of ZrO2, TiO2, Al2O3 between 1550°C to 1600°C. Densification depends on the function of temperature and MgO addition. It shows in significant change in densification as well as micro-structure development upto a 1mole percentage. XRD study showed that MgO addition facilitated the stabilization of tetragonal and cubic zirconia together with aluminum-titanate and Magnesio-aluminate with a dense microstructure. This Ternary system we used to mention as composite in the proceeding orders to understand clearly and this composite (Ternary system) was used at High temperature applications, it resists to mechanical (erosion) and chemical attack and thermal properties. The role of MgO in matrix is stabilized the zirconia. The result is expected to develop the formation of MgAl2O4 spinel phase and ZrTiO4 spinel phase and produce the cubic-zirconia phase with alumina Titania reinforcement. [ABSTRACT FROM AUTHOR]

Electronic and thermal properties of rare-earth chalcogenide compounds R2X3 (R = Dy/Tb and X = S/Se) are investigated using Density Functional Theory. The effective mass, deformation potential and elastic constants are calculated. The rare-earth chalcogenide compounds are dynamically stable. The lattice thermal conductivity for these compounds is calculated using slack model. The lowest value of kl 4.5W/mK is obtained for Tb2Se3 This low thermal conductivity of these compounds can have several application in various fields like thermoelectric, thermal insulation and phononics. [ABSTRACT FROM AUTHOR]

Ceramic materials based on the composition 0.98(Na0.5K0.5NbO3) + 0.02(Sr Bi0.5Nb0.5O3) + x ZnO (x=0.0, 0.45) have been synthesized through a solid-state reaction method and characterized to explore their unique properties and potential applications. In this study, we investigated the influence of varying " x wt% ZnO values on the physical, electrical, and structural characteristics of Na-K-Nb-O and Sr-Bi-Nb-O matrix (coded as NKBN) ceramics. Our findings show that the dielectric characteristics of the NKBN ceramics are significantly affected by the addition of ZnO to the ceramics. We noticed differences in the dielectric constant and dielectric loss depending on the ZnO doping. Additionally, the crystal structure and microstructure of the ceramics were revealed through structural analysis utilising methods including X-ray diffraction and scanning electron microscopy, which had an impact on their mechanical and thermal properties. With rising frequency and temperature, it was found that the dielectric characteristics decreased, which showed that the samples' conductivity had increased. The change in dielectric behavior were observed and confirmed from the dielectric study of the samples for electronic application. [ABSTRACT FROM AUTHOR]

Using the ab-initio FP-LAPW technique, the structural and thermal characteristics of V3Si are investigated. The equilibrium structural parameters and the formation enthalpy obtained are in good agreement with the results of the existing experimental and theoretical data. To determine the internal energy, Helmholtz free energy, entropy, heat capacity at constant volume and pressure, Grüneisen parameter, thermal expansion coefficient and Debye temperature of V3Si, the ab-initio total energy calculations are linked with the second-generation software Gibbs2. It employs the Debye Slater and Debye Grüneisen models. The existing experimental and theoretical data are in accord with all of the current findings. [ABSTRACT FROM AUTHOR]

Utilizing the D-Optimal Mixture in Design of Experiments (DOE) software, this investigation aimed to create a composite of recycled polypropylene-reinforced oil palm vacant fruit bunches and fly ash. The formulation was derived by employing many ratios based on the data collected through the utilization of Design of Experiments (DOE) software. The thermal properties of twenty formulations were compared by analyzing their reaction by Thermogravimetric Analysis (TGA). The residue remaining, also known as ash content, was utilized as a criterion for selecting the optimal formulation ratio. This study endeavors focused on investigating the feasibility of achieving optimal flame-retardant composite formulations through the precise blending of appropriate ratios. Thermogravimetric Analysis (TGA) was employed to acquire the thermal characteristics. The temperature of the thermogravimetric analysis (TGA) was recorded within the range of 25°C to 900°C, employing a heating rate of 10°C/min and utilizing nitrogen gas as the medium. The formulation of the composite was determined by utilizing Design of Experiment (DOE) software to analyze its thermal response. This formulation enhances the thermal breakdown of pure recycled polypropylene, resulting in a 50% increase in ash residual content. The thermal degradation loss rate is observed to decrease from 152.40°C to 95.34°C. The formulation of recycled polypropylene reinforced with oil palm empty fruit bunch (OPEFB) and fly ash (FA) for enhancing thermal properties is considered to possess promising potential as a substitute for synthetic fibers in the context of building insulation. [ABSTRACT FROM AUTHOR]

This paper presents an optimization of the Al2O3/distilled water-based nanofluid process parameters for enhancing its thermal conductivity. Nanoparticle volume concentration, nanoparticle size, sonication time, stirring time, and surfactant volume concentration are selected as optimization factors to obtain higher thermal conductivity. Eighteen different nanofluid samples having various preparation parameters are determined and prepared as per the Taguchi orthogonal array. Thermal conductivity was measured using the KD2 Pro thermal properties analyzer at a working temperature of 28 °C. To study the structure and crystallite size of alumina nanoparticles, we used X-ray diffraction. A scanning electron microscope is used to investigate the morphology and size of Al2O3 nanoparticles. To assess the effect of each parameter on thermal conductivity, the main effect plot for means and the signal-to-noise ratio are utilized. The statistical contribution percentage of each parameter on thermal conductivity is determined using an analysis of variance. The signal-to-noise ratio demonstrated that the nanoparticle concentration in a base fluid is the most affecting parameter, with a delta value of 0.715. Furthermore, with delta values of 0.461, 0.413, 0.272, and 0.177, the stirring time, sonication time, surfactant concentration, and nanoparticle size all play significant roles in nanofluid thermal conductivity. The outcome of the analysis of variance shows that the nanoparticle concentration in the base fluid has the most significant impact on the thermal conductivity of the nanofluid with a contribution of 36.64%, whereas initial stirring has a contribution of 26.82% and sonication time has a contribution of 19.76%, while surfactant concentration has an 8.83% contribution and nanoparticle size has a less significant contribution with a 4.06% contribution on the thermal conductivity of the nanofluid. The obtained results indicate that the thermal conductivity of the Al2O3/distilled water-based nanofluid increased by 7.146% compared to the base fluid, i.e., distilled water. The optimum thermal conductivity is obtained as 0.640732 W/m-K at optimum parameter settings of 0.3% of nanoparticle concentration, with a nanoparticle size of 50 nm, 40 minutes of sonication time, and 10 minutes of initial stirring time with 0.2% of surfactant concentration, A confirmation test with optimized parameters was finally carried out to ensure the method's confidence. [ABSTRACT FROM AUTHOR]

Now-a-days technologists are more interested opted as one of the prime research in the natural fibers in order to save the entire eco system. In this reason behind, technologists doing vigorous materials characterization on newly available natural fibers and find out the newer natural fibers to increase the increasing demand on the materials science. Since natural fibers are abundantly available in nature, as well processing and disposable after use also would not affect the eco system as such observed in the synthetic fibers, because of this reason natural fibers are widely opted for various purposes. Moreover, plant are rich in fibers and easily cultivated throughout the year, apart from that it has the better weight to stiffness ratio and not hazardous to human health. Besides, natural fibres provide enhanced thermal and acoustic wadding as compared to synthetic fibers. Additionally, fibers gotten from the numerous plants are processed and mixed with (Reinforced) various set of matrix materials to enhance their physical and thermal properties. This current research article examines various natural fibers material currently being used in the industry and their current eminence in the specific research activity. [ABSTRACT FROM AUTHOR]

Composites prepared by Friction stir processing (FSP), having exceptional surface characteristics, are being widely used in various thermal environments, such as in automobiles and aircraft industries. The addition of one or more ceramic reinforcements may improve their thermal conductivities and reduce the thermal expansion coefficients leading to greater dimensional stability thereby making them more efficient for such applications. In the present work, FSP is utilized to fabricate surface composites with varying compositions of copper and graphene powders as the reinforcements. The composites prepared are inspected for their thermal and microstructural characteristics for different reinforcement compositions and FSP pass numbers. It is observed that the composites with higher copper weight% have higher thermal expansion coefficient in comparison to that with lower copper weight%. Also, the addition of higher graphene content in the aluminium alloys lowers the coefficient of thermal expansion (CTE) of the composite and vice-versa. Besides, the composites prepared by lesser number of passes (two) have higher values of CTE than that prepared by higher number of passes (four). This is due to the reason that the microstructure of the composite is more refined when prepared with more pass numbers and so the space between the particles is lesser preventing the tendency of the sample to be easily be expanded on heating. This approach finds a wide scope to draw useful insights for the composite fabrication conditions for their high temperature applications. [ABSTRACT FROM AUTHOR]

The article is focused on studying Fused Filament Fabrication (FFF) of alumina-filled polymer objects and their thermal properties. To track influence of inclusion type on thermal diffusivity of 3D printed samples with equiaxed and needle-like Al2O3 particles were made. The difference between the microstructure of needle and equiaxed compositions was evaluated using Phenom G2Pro (Phenom-World BV, Eindhoven, The Netherlands). The tests of thermal diffusivity were carried out on LFA 467 HT HyperFlash setup (NETZSCH Inc., Germany). It was found that the addition of 20 vol. % of ceramic particles in polyamide (PA12) increases its thermal conductivity, and the shape and location of inclusions play an important role in heat flow processes. It is shown that specimens with alumina needle-like inclusions demonstrated the highest values of thermal diffusivity. [ABSTRACT FROM AUTHOR]

The bio-heat equation is a popular tool for determining how heat is distributed in living organisms. Moreover, the Pennes bio-heat equation is crucial in the field of ablation therapy computation. Using the finite element approach, we investigated the stability criteria for the bio-heat equation in this article. In a semi-discretized finite element formulation, first-order difference techniques are employed to discretize the time derivative term. When the implicit scheme is replaced with the explicit scheme, the time step becomes reliant on the thermal properties of the tissue and the eigenvalue of the global matrix. [ABSTRACT FROM AUTHOR]

Measurement and assessment of thermo-physical properties of magnesium oxychloride cement (MOC) with implemented phase change material based on paraffin wax encapsulated in polymer shell, is presented in the paper. The measurement method and mathematical interpretation of thermal conductivity and specific heat capacity assessment was derived from the Thermophysical Transient Tester 1.02 that was developed at the Institute of Physics, Slovak Academy of Sciences. Within the test, thermal responses between two thermal sources were measured during the step wise heat reference source and source generating step wise heat. It was revealed that both investigated thermal parameters depend on the dosage of PCM in composite mixture, thus porosity of prepared materials and thermal characteristics of PCM itself. The obtained data point to the substantial improvement of heat storage capacity of MOC by the use of powdered PCM. [ABSTRACT FROM AUTHOR]

Although the term of women leadership sound familiar due to its significance on achieving gender equality in all nations, however lack of evidence was found on this domain particularly in the context of Malaysia. Following that, this research aims to examine the associations between personality, work-life balance (WLB) and emotional intelligence (EI) towards women leadership, specifically in the Malaysian manufacturing-based industry. A total of 391 out of 1846 engineers from the Malaysian manufacturing-based companies filled out questionnaires. SPSS was used to analyse the associations between all variables. Also, the mean for all variables were reported in this research. Specifically, a high mean indication with µ=4.02 for women leadership; µ=3.96 for personality; µ=3.85 for WLB; and µ=4.10 for EI were revealed based on this research. Next, Pearson correlation results presented the highest association between WLB and women leadership (r=.737, p=.000); followed by personality (r=.724, p=.000); and EI (r=.722, p=.000). This research added new information to the existing literature by empirically tested the role of personality, WLB and EI on women leadership. Thus, by nurturing the proven indicators of polishing the women engineers to be leaders in the manufacturing-based companies, the goal of gender equality for the country was expected can be achieved. [ABSTRACT FROM AUTHOR]

Biomass is widely recognized as an essential source of renewable energy. The most abundant organic resources in the plantation field are oil palm frond (OPF) and trunk (OPT). These lignocellulose biomaterials are rich in renewable biobased products. The recalcitrance of oil palm biomass directly linked with the cellulose, hemicellulose, and lignin structure remains a challenge. The pretreatment process is still a consideration because the recalcitrant lignocellulose structure prevents depolymerization from releasing the appropriate substrate to a new approach. This study is aimed to characterize the oil palm frond and trunk pretreated by a combination of ultrasonication with a dilute sulfuric acid medium. This study considers the morphological and thermal characteristics intending to explore their future potential application. The procedure in this research was that the raw OPF and OPT were weighed and transferred into a 1000 ml beaker containing a low acid concentration of H2SO4 in the ratio of 1: 25. The deionized water (DW) was used as a control. The mixture was stirred and incubated in an ultrasonic bath for 30 minutes at an ultrasonic frequency of 40 kHz and an ambient temperature of 80°C. The operating time and power were set at the start of the pretreatment. The ultrasonicated materials were characterized by Scanning Electron Microscope (SEM) and Thermogravimetric Analysis (TG-STA). The results demonstrated that the yield percentages of OPT's ultrasound-assisted low sulfuric acid (ULSA) are about 10% higher than the deionized water pretreatment. SEM results showed that the ULSA pretreatment of OPF and OPT revealed a significant disruption of their surface structures. The DTG analysis revealed that the maximum temperature degradation of ULSA pretreatment is shifted to a higher temperature than the raw material, which is 273.43℃ for OPF and 265.15 for OPT to 314.43℃ for ULSA-OPF (SOPF) and 318.88℃ ULSA-OPT (SOPT). The thermogravimetric data indicates that the ULSA pretreatment produced more thermal stability than untreated oil palm biomass. Thermal stability is an essential criterion for determining the best lignocellulose material for a particular application, including energy. Hence, ultrasound coupled with the low sulfuric acid medium in both oil palm frond and the trunk has potential as a renewable material for use in many future applications of the bio-based material. [ABSTRACT FROM AUTHOR]

Gelling polymers, used for the fabrication of hydrogels, are employed for various applications in medical engineering. The present paper explores a novel approach for the additive manufacturing of polypropylene-hydrogel composites by applying laser-based powder bed fusion of powder blends at ambient temperatures, hence allowing for the integration of additives sensitive to heat degradation. Based on applying superposed fractal exposure strategies for the temporally and spatially discretized melting of prepared powder blends, the processing of composites containing a proportion of up to 75% of agarose can be demonstrated. Prepared specimens depict a water absorption exceeding 100 wt-% while exhibiting non-linear, progressive mechanical properties under compressive stress and enhanced stress relaxation similar to human cartilage tissue. The results illustrate the suitability of fractal exposure strategies for the processing of materials sensitive to heat degradation with divergent thermal properties. Furthermore, the proposed approach provides a novel process route for the fabrication of functionalized polymer components, representing a foundation for the integration of hydrogels for medical applications, such as drug delivery applications and functionalized, load-bearing scaffolds. [ABSTRACT FROM AUTHOR]

Thermoplastic over-extrusion is a continuous production process in which reinforcing UD-fibers are preheated and guided at constant line speed into an extrusion die. Here the fibers are surrounded by molten polymer. After the extrusion die, the composite is cooled by a combination of calibration units and water baths. At the end of the process line, the parts are cut to length. Products made with this process have a (or multiple) reinforced zone(s) in their cross-section, allowing for improved mechanical performance with a minimum of reinforcing materials when strategically located. However, due to the mismatch in coefficient of thermal expansion between the reinforcing fibers and the surrounding polymer, excessive warpage and residual stresses after cooldown are often present in the final products. Reducing these unwanted effects is currently done by a costly and lengthy trial-and-error approach. This study presents a multiphysics (thermal-structural) simulation laying the basis to predict warpage and residual stresses in an over-extruded product with complex cross-section using UD-GF/PET commingled yarns over-extruded with rigid PVC. It makes use of experimentally determined temperature-dependent mechanical properties as well as temperature-dependent thermal properties (specific heat capacity, thermal conductivity). The finite element model is compared to experimental data in order to check the validity. The thermal simulation has a maximum deviation of less than 15% when compared to experimentally determined temperatures. A strong overestimation is observed regarding the warpage prediction when compared to experimental data, which has been attributed to the simulated bonding conditions between the components. [ABSTRACT FROM AUTHOR]

All-cellulose composite (ACC) is a novel single component bio-based material that consists of cellulose for both fiber and matrix phases. ACC has good mechanical, thermal and optical properties due to the compatibility of fiber and matrix phases. However, abundant hydroxyl groups in the cellulose molecules make ACC hydrophilic thus limiting the potential outdoor applications of ACC. In this present study, the ACC was fabricated by using solvent infusion processing (SIP) from rayon textile. The NaOH/urea was used as the solvent to partially dissolve the cellulose. Then, ACC was treated with hexadecyltrimethoxysilane (HDTMS) to produce hydrophobic ACC. The FTIR spectra of HDTMS treated ACC showed the new peak appears at 2850 cm−1, 1103 cm−1, and 793 cm−1 that attributed to -CH2 stretching, asymmetric stretching of Si-O-Si band and Si-OH stretching vibrations, respectively. The surface morphology of HDTMS treated ACC was rougher compared to untreated ACC. Furthermore, the HDTMS treated ACC exhibited significant hydrophobicity with a high water contact angle that can go up to 145.1°. [ABSTRACT FROM AUTHOR]

The present study uses density functional theory (DFT) and non-equilibrium Green's function (NEGF) to investigate the transmission coefficient T (E) for dithino-naphtridine molecules with different positions of side group oxygen atoms. The electric conductance calculation shows that the bare molecule has a higher conductance than the molecules with oxygen dangling, which varied from-4.7 to-5.5(eV), while the Seebeck coefficient (S) is found for all molecules with a positive sign with a higher value of 254 (µV/K) for molecules terminated by hydrogen around Fermi level EF = 0. Other thermal parameters are calculated, such as thermal conductance K which is found to change between 55 x10−15 for M_1and 4x10−15 (w/K.m) for M_3. Finally, the higher value of the figure of merit (ZT) is about 0.8 for molecule M_3. [ABSTRACT FROM AUTHOR]

The household sector consumes the largest amount of energy compared to other sectors in Indonesia. The most consuming instrument is the air conditioning (AC) system, as the tropical climate of Indonesia yields outdoor temperature that is higher than the standardized temperature for thermal comfort. Phase change material (PCM) possesses the potential to reduce the employment of energy for the AC system by reducing the total envelope heat transfer rate incorporated into a building through the walls. However, the selection of PCM and its integration configuration with the building materials are subjected to the climate environment. This study examined the thermal performance of some PCMs that are integrated with lightweight concrete through numerical simulation using EnergyPlus software. The integration of lightweight concrete with a PCM titled RT 35 manufactured by Rubitherm Technologies GmbH company yields the highest envelope heat gain transfer rate reduction. Meanwhile, the middle-layer placement of the PCM performs better than the configurations that placed the PCM on the wall's outer and inner surface. This is due to the PCM being imposed on a smaller temperature difference with its surroundings. Analysis of the thermal properties of the 20 mm thick PCM RT 35 placed on the middle layer of the walls yields the thermal resistance value of 0.141 m2-K/W. [ABSTRACT FROM AUTHOR]

This article presents the results of the thermal properties of modified cellulose-containing materials with oligomeric flame retardants synthesized on the basis of 3-chloro-1,2-hydroxypropane with 2,4,6-triamino-1,3,5-triazine. The dependences of the mass loss of cellulose materials modified with a fire retardant, the rate of mass loss, temperature, and the dynamics of the release of combustible gases from time to time were studied. [ABSTRACT FROM AUTHOR]

In recent years, materials of nanometric size have become the object of interest of scientists, due to the possibilities of using them in various industries, including the paint and varnish industry. Companies are looking for new solutions and patents to make coatings mainly environmentally friendly as well as harmless to people. Very often, scientists use nano-metals or their oxides, because they are characterized by different properties at the nano-scale. The aim of the study was to obtain silver nanoparticles by reducing silver nitrate and their addition to the paint composition. The stability and size of particles of dispersion systems containing nano-silver have been examined. It was found that the nano-silver content in the amount of 2% (w/w) exerts a positive influence on the stability. More detailed analysis has shown that the dispersion system under consideration undergoes the normal distribution. More amount of nano-silver makes the particles smaller. The studies of the thermal properties of the layers obtained from the paint composition showed that the increase in the nano-silver content in the system shifts the range of the film temperature towards higher values. Consequently, the layer becomes harder and less flexible. Derywatography analysis has indicated that the maximal temperatures of the exothermic effect−after addition of nano-silver particles−lead to higher temperature values in the systems. It was shown that the addition of nano-silver into the varnish composition has a beneficial effect both on its stability (backscattering, turbiscan stability index) and the properties of the layers formed. [ABSTRACT FROM AUTHOR]

A composite hydrogel beads bio-sorbent was introduced through this work by cross-linking cellulose, chitosan, magnetite, and alginate (CCMA) for removal of heavy metal copper. The effect of CCMA's dosage and contact time in adsorbate solution was also studied through this work to determine the highest percentage of copper metal, Cu (II) removal. Based on the effect of CCMA dosage and adsorption contact time in copper solution studied, an excellent percentage of Cu (II) removal of 97.47% was achieved at 4g of CCMA dosage and 24-hour contact time to reach its adsorption equilibrium state. Moreover, the thermal properties and stability of CCMA investigated through TGA analysis in this work revealed that the thermal stability of CCMA was significantly improved with a high mass residual of 92.35% compared to cellulose and chitosan powder. Thus, it is proven that the cross-linking of cellulose-chitosan-magnetite-alginate (CCMA) in this work was successfully done. [ABSTRACT FROM AUTHOR]

This study investigates the influence of microstructure and its related performances on the thermal and mechanical behaviors of porous concrete impregnated with phase-change material (PCM), referred to as PoroPCM. The material is composed of microencapsulated PCM particles embedded in a composite of aqueous foam and cement paste binder. Cement paste and 20% volume replacement of paraffin-based melamine-formaldehyde-coated PCM were used to prepare the paste, which was mixed with 20%, 40%, and 60% volume substitution of foam to prepare specimens. Two mixing methods were applied, one involving gentle mixing and other utilizing a high energy mixer. X-ray computed tomography (CT) was used to visualize the 3D microstructures of the specimens, and the datasets obtained from X-ray CT scans showed that micropore structures differed according to the mixing method. Thermal behavior was measured by inserting thermocouples at the center of cube specimens and increasing their temperature in a controlled environment chamber. Results of temperature rise at the center of cube specimens showed significant temperature control performance (temperature rise delay) with the phase transition of PCM. While compressive strength results revealed that it depended mainly on the porosity of the specimens, the specimens failed with large ductile deformations and cracks failed to propagate owing to the disaggregation of local collapse of the pore walls. [ABSTRACT FROM AUTHOR]

Currently, fiberglass is used as an insulation material, and this synthetic fiber is categorised as non-biodegradable and causes air pollution. This study compared the thermal and acoustical properties of Betong bamboo (Dendrocalamus Asper) and fiberglass. Conductivity (K-Value) and sound absorption coefficient (SAC) were measured for both materials. The SAC was calculated using an impedance tube at low and high frequencies in accordance with EN ISO 10534-2:2001, while thermal conductivity was measured using Solteq HE110 thermal conductivity apparatus. From data analysis, the k-values of bamboo and fibreglass were 0.05 and 0.04, respectively. The analysis also showed that the difference in k-value between natural and synthetic fibers was 0.01 at 25 mm thickness, while fiberglass was 4.986. For sound acoustic, bamboo fibre showed 0.54 and 0.86 SAC between 2000 Hz and 2500 Hz, while 0.47 and 0.71 SAC were recorded for fibreglass. It can be concluded that bamboo fibre could be used as thermal and sound insulation, with performance equal to or better than fibreglass. Further research can be extended to make bamboo fibers as natural insulation for ducting, or in building. This study recommends refining bamboo fibres using different binders to increase durability and be used as insulation in the future. [ABSTRACT FROM AUTHOR]

A cementitious composite carefully designed and mixed using aggregates, cement and waste materials forms a green concrete, providing potential for saving the environment, especially by reducing the carbon consumption in the construction industry. The reliable design of green cementitious composites' thermal conductivity leads to significant energy savings in residential buildings, especially when used as exterior or interior walls. This preliminary study briefly describes a concept of mathematical modeling of green concrete heat transfer since an effective solution to the problem will not only improve the energy saving inside the residential but also increase the efficiency in heat-protection of the structures. The study aims to generate a mathematical model to simulate the thermal properties into a computational model to understand the model behaviour under constant and elevated temperature considering steady-state and transient-state solutions. A two-dimensional thermal model is created first then the thermal properties such as thermal conductivity, mass density, and specific heats are assigned into the model. Seven variables to express the thermal conductivity of concrete are adopted in this study based on previous research. The analysis is then continued by specifying a heat source within two model geometries, i.e. a solid model and a model with cavity. The heat flux is also assigned to estimate the heat exchange between the boundaries. The model is then analyzed, the mathematical model is solved to generate the results of temperature, gradient, and heat rates as well as heat fluxes. This study enables the characterization of thermal transfer and distribution on a green concrete model to be used as approximations in predicting the trends related to thermal properties of a green cementitious composite. [ABSTRACT FROM AUTHOR]

In this research, nano composites materials consisting of epoxy coating were prepared as a base material (EP) and some different oxides nano particales (TiO2, SiO2, Al2O3) as reinforcement materials include (EP+ TiO2), (EP+ TiO2 + SiO2), (EP+ TiO2 + Al2O3) to improve several of mechanistic and thermal properties of epoxy coating at a weight fraction (4w%). Mechanical properties (tensile strength, impact strength, hardness) and thermal conductivity studied. The method of Hand Lay -Up molding was used to prepare the Nano composites materials, and from the results obtained, mechanical and thermal properties after reinforcement by the oxides nano particles has been improved, where the nano composite material (EP+ TiO2) had the highest value for tensile strength(8.48) ᴍPa, hardness(77.9) and thermal conductivity(0.526671) watt / m. c◦, while the composite material (EP+ TiO2+ SiO2) had the highest value for impact strength(7.96) KJ/m2. [ABSTRACT FROM AUTHOR]

Knowledge of the thermal variation of elastic properties of solids is essential for proper design and selection of solids in case of their thermal properties study. An Equation of States (EoS) based investigations have been done to characterize the thermal variations of elastic properties for solids. To make a good understanding for the equation of state for solid, the analysis of temperature dependence behaviour of elasticity is reported in this work. We have investigated the thermal variation of volume for NaCl, KCl, MgO and CaO based on Anderson model. We have evaluated the values of elastic constants C11, C44 and KT at different temperatures based on Murnaghan and Tallon models. The Tallon's model with second approximation presents somewhat reliable agreement with experimental results. It is shown that the Anderson-Gruneisen parameter may be pondered as directly proportional to the volume ratio. The Debye temperature (θD) for NaCl and KCl are close to room temperature (304 and 230 K) whereas those for CaO and MgO are much higher (945 and 670 K). We have taken a temperature range from room temperature to 950 K for NaCl, KCl and upto 2800 K for CaO and MgO. This theoretical method can be used to successfully predict the values of elastic constants for solids. [ABSTRACT FROM AUTHOR]

Recently, new composite materials based on natural wood-based materials have been increasingly used in modern construction of houses because of their good physical, mechanical and thermal insulation properties. This raises the need to characterize their Thermophysical properties. As part of our project 'Research of selected properties of sustainable insulating materials with the potential for use in wooden buildings', we measured samples of High and Middle density particleboards made from chips of Turkey oak wood (Turkish oak HDPB, Turkish oak MDPB) and samples made from mixture of Turkey Oak wood and Orange wood (OOPB). A cuboid model for the pulse transient method was used to estimate the parameters. The model takes into account the cuboid geometry of the sample with a square base, the heat losses from the free surface of the sample to the surroundings using the coefficient of heat transfer from the surface of the sample to the surroundings in the lateral direction, as well as the infinitely large heat capacity of the heat exchangers between which the sample is placed. The heat transfer coefficient between the heat source and the sample is infinitely large. The surface of the particleboard is usually rough and porous due to the size and nature of its particles. In addition, the interfaces of the three parts of the sample set are hand-polished, so that the edges and corners are not perfectly flush with the central area of the surface. As a result of manual polishing, the interfaces at the corners and edges of the sample parts usually have air-filled gaps. Free gaps cause additional thermal resistance to heat flow from the heat source to the body of the sample. Then, the coefficient of heat transfer from the heat source to the sample is not infinitely large and does not correspond to the conditions of the cuboid model. While the Turkey Oak HDPB had a perfectly flat surface, the Orange-Oak PB suffered from loose gaps at the interfaces. Therefore, we filled them with silicone glue as a thermal contact agent and measured them again. The consequence of flatness differences for all results was discussed within the theoretical analysis based on sensitivity coefficients, uncertainty calculations, as well as the assumption of a thermally dependent heat transfer coefficient between the heat source, air gap and the sample. The criterion for the quality of the fitting of the thermal responses by the cuboid model was the residual graph within the thermal noise of the thermocouple ± 0.005 K. [ABSTRACT FROM AUTHOR]

The measurement of thermal properties, such as thermal conductivity, thermal resistivity, heat capacity, and thermal diffusivity for materials, is essential for many civil and electrical engineering projects as well as numerous field applications, including heating the soil beneath a building, producing electricity, removing waste from thermal and nuclear power plants, and burying cables. Different geotechnical factors, such as the type of soil, water content, grain size distribution, density, and compaction factors, all affect the thermal conductivity of soil. Literature studies has been done related to work and presented in this paper. In previous research, heat source methods were used to test the thermal conductivity of soil. Consequently, doing laboratory and field measurements is expensive and time-consuming. In this work, a constructed probe is used to measure thermal conductivity. Glycerin was used to calibrate the manufactured probe. Water has a greater thermal conductivity than soil minerals, and particle to particle interface increases as density improves. As a result of these fundamental influences, thermal conductivity of the soil improves as water content and density improves. Therefore, obtained thermal conductivity values were represented and explained with graphs for considered materials. [ABSTRACT FROM AUTHOR]

This study aims to assess the mechanical and thermal characteristics of epoxy/aluminum and unsaturated polyester/aluminum composite systems, using the formulations (1-x) EP+(x) Al microparticles and (1-x) UP+(x) Al microparticles, where x equals 0.00, 0.01, 0.03, and 0.05 wt%. Test specimens were created using an open mold-type die, and their impact strength, hardness, and thermal conductivity were experimentally examined. According to the results, epoxy/aluminum composites achieved their highest impact strength (15.63 KJ/m2) at 0.05 wt%, while the unsaturated polyester/aluminum composites achieved their highest impact strength (8.03 KJ/m2) at the same weight percentage. Moreover, the epoxy/aluminum composites exhibited superior impact strength compared to the unsaturated polyester/aluminum composites at the 0.05 wt% ratio. In terms of hardness, the epoxy/aluminum composites reached the highest Shore D value (78.6 H.NO.) at 0.05 wt%. On the other hand, the unsaturated polyester/aluminum composites displayed higher Shore D values (88.03 H.NO.) in the laboratory, with the 88.03 value being the highest for this type of composite, compared to 78.6 for the epoxy variant. Lastly, the thermal conductivity (K) value increased in both epoxy/aluminum and unsaturated polyester/aluminum composites as the proportion of added aluminum powder grew. [ABSTRACT FROM AUTHOR]

Previously, the nano-sized tricalcium phosphate samples are prepared by the sol-gel method in this work. There are three samples of the nano-sized tricalcium phosphate resulted from its gel in the dry form, when temperature at 800 °C, 1000 °C, and 1200 °C are applied on the gel phases of the sample. After that, several parameters of the crystal characteristic have been confirmed by using the XRD to reveal the relevant parameters, such as the crystallite size, crystallite strain, crystallite dislocation, and crystallinity degree. Meanwhile, the thermal characteristics, such as the melting point, specific heat capacity, enthalpy of fusion, and crystallization enthalpy parameters, they are studied by using the DSC-TG. [ABSTRACT FROM AUTHOR]

Nowadays, the adaptability of biodegradable Polyhydroxyalkanoates (PHA) polymer has been thoroughly assessed to its full potential including shape, mechanical characteristics, thermal properties and biocompatibility. Additionally, PHA has been produced as biomaterials with potential applications in bone regeneration. Similar to the mineral apatite found in human bones, nano calcium phosphates (nCaP) are minerals that are necessary for tissue development and cell adhesion, which have an impact on newly formed apatite. This study aims to investigate the influence of additives on thermal stability of biocomposite via thermogravimetric analysis (TGA) machine. PHA pellets were mixed with nCaP as filler ranging from 3-15wt% and 10wt% of chitosan binder via conventional melt compounding. Thermal analysis showed that the addition of bio-filler improves thermal stability of PHA with highest onset temperature recorded at 208.1°C. Morphological analysis showed that the addition of nCaP and chitosan alters the flow characteristics of the composite resulting in surface roughness. Subsequently, in order to prevent the biocomposite from decomposing, all heat-related activities particularly those involving machining, it is recommended to perform at temperatures that do not exceed the onset temperature. [ABSTRACT FROM AUTHOR]

Polyurethanes (PURs) are a group of materials that have gained significant attention in recent years due to their unique properties and wide range of applications. PURs are known for their excellent mechanical properties, chemical resistance, and durability, making them highly desirable in many fields, including automotive, construction, and biomedical industries. This work aims to provide a comprehensive analysis of the changes in dielectric properties that occur when magnesium oxide (MgO) nanoparticles were incorporated into PURs at different weight ratios (1, 3 and 5 wt.%) via direct dispersion method. Specifically, it concerns the dielectric parameters such as relative permittivity, dissipation factor, or volume resistivity at different voltage (0.5–2 kV) and temperature (30–120 °C) ranges. The results of this study have important implications for the use of PURs in the electrical industry. The following facts result from the conducted investigation. The addition of magnesium oxide has a significant effect on the thermal stabilization of the resulting material, particularly with regard to the dielectric losses (decrease within one order of magnitude), relative permittivity (decrease up to 12 %), and volume resistivity (increase within the order of magnitude). The effect of the applied field intensity is negligible within the monitored voltage ranges. The conducted research has demonstrated that the incorporation of MgO nanoparticles into composites can enhance their electrical and thermal properties, thus making them highly desirable for diverse applications. [ABSTRACT FROM AUTHOR]

Nylon coil springs are thermally controlled linear actuators. They have a perspective application as artificial muscles. This article describes thermal experiments that were conducted on samples to determine thermal properties of these coiled springs. The experiments were performed in a temperature regulated environmental chamber. Measurements correctly shown negative value for the coefficient of apparent thermal expansion. Results of these experiments will be used to validate numerical models. [ABSTRACT FROM AUTHOR]

The study of structural, electronic, and thermal properties of two dimensional NbSe2 monolayer is performed using density functional theory (DFT). The binding energy and phonon spectra are calculated to ensure the structural and thermal stability of the monolayer. Moreover, the free energy, is decreases with the temperature while the entropy and specific heat increases. The reason of metallic character of NbSe2 ML is discussed. Furthermore, the stress-strain relationship is studied to calculate the tensile strength. The uniaxial strain deviate the C3v point group symmetry which leads to induced half metallic nature of monolayer manifests its important application in the field of futuristic spintronics. [ABSTRACT FROM AUTHOR]

Fabrication of wearable sensors using composites with zero temperature coefficient of resistance (TCR) as sensing materials is an effective strategy to eliminate temperature interference. The zero TCR feature can be realized by choosing specific composites that contain two elements with positive and negative TCR as sensing materials. Metal nanowires exhibit an increase in resistance with temperature (positive TCR) whereas reduced graphene oxide (rGO) exhibits an opposite behaviour (negative TCR). Zero TCR for the composite can be achieved by tuning the composition such that the TCRs of the metal nanowires and rGO cancels out. Herein, we use silver nanowires owing to its high conductivity, good mechanical and electrical properties and rGO due to its zero bandgap. AgNWs were synthesized using low temperature hydrothermal method having average aspect ratio about 17 and an ink is prepared. The structural, morphological and thermal properties are investigated. [ABSTRACT FROM AUTHOR]

Fiber-reinforced polymer composites have extended their discovery and application in a variety of industries, such as automobile, marine and aerospace. Polymer composite materials are used to protect the re-entry space vehicles from heat. Carbon fiber (Cf) composites based on polyacrylonitrile (PAN) reinforced along with phenolic resin (PR) are suitable for high-temperature thermal protection system (TPS). This paper describes the experimental evaluation of PAN-based carbon-phenolic composites for thermal protection system. The hand-layup approach was utilized to construct the Cf-PR composite laminates, with curing temperatures ranging from 120°C to 150°C and pressures ranging from 80 to 100 kg/cm2 for four hours under a hydraulic hot compression machine. The prepared composites were characterized by, interlaminar shear strength (ILSS) and flexural strength, compression strength, bar coal hardness, thermal conductivity, and density tests. The Cf-PR developed composites shown good thermo-mechanical properties for the application of TPS. [ABSTRACT FROM AUTHOR]

Cellulose is the most abundant biomass material in nature and has several promising properties. Interest in nanocrystalline cellulose (NCC) has increased dramatically exponential because it is relatively easy to prepare in high yields, it is strong, has a low weight, a high specific surface, thermal stability, and is biodegradable. NCC with a length ranging from 100 to 500 nm and a diameter of less than 10 nm, is a promising material because it can be applied in various fields, such as biomedicine, adsorbent, emulsifier, filler, and a composites. However, the hydrophilic properties of the NCC surface causes a the limited application because of its incompatibility with hydrophobic polymers. Therefore, various modifications to the surface of NCC have been investigated to increase the compatibility between NCC and hydrophobic matrix polymers. This paper summarizes several methods that can be used for surface modification of NCC, including cationization modification, acetylation, oxidation, carbamination, non-silane and its application resulted a better interaction with a hydrophobic polymer. The improved mechanical, barrier, water resistant and thermal properties have a positive effect when the NCC is used as reinforcement material. [ABSTRACT FROM AUTHOR]

This study focuses on evaluating the thermal conductivity of different types of sandwich panels. The first type was a traditional sandwich panel made of two galvanized steel face sheets with a core of polyurethane foam (PSP); the second was a honeycomb sandwich panel made of two face sheets of aluminum with a structural core of polyvinyl chloride PVC tubes (HSP1); the third was (HSP1) with the thermal insulation paint coated on the two face sheets (HSP2); and the fourth was (HSP1) using polyurethane foam to fill the core cells (HSP3). The properties of heat transfer and thermal conductivity of sandwich panels were investigated. The third honeycomb sandwich panel (HSP3) has lower thermal conductivity compared to the other tested sandwich panels, with significant mechanical properties. [ABSTRACT FROM AUTHOR]

The epoxy system content in the filament winding process is significant for the mechanical and thermal properties of the rocket motor casing. Three types of epoxy resin with different epoxy and hardener compositions were studied using Differential Thermogravimetry/Thermal Gravimetry Analysis (DTG/TGA) and Fourier Transform Infra-Red (FTIR) spectroscopy. The cured epoxy resin's thermal stability was analyzed using the Integral Procedural Decomposition Temperature (IPDT) and ASTM E1131-08. After heating to 750 C, Gurit (GU) and Huntsman (HU) epoxy resin systems have stages decomposition process, and both have lost almost all their mass (∼99%). In comparison, the Gurit Silres (GS) epoxy resin has three stages of the decomposition process but lost only 73.85% of its mass. The IPDT results show that GS epoxy resin has the highest thermal stability. The FTIR images revealed that the GS epoxy resin system has siloxane groups (Si-O-Si and Si-O-C) that contributed to higher thermal stability than the GU and the HU epoxy resin system. The result suggested that the GS epoxy resin system is thermally stable and recommended for the filament winding process of rocket motor casing. [ABSTRACT FROM AUTHOR]

Natural fibers taken from the trunk which are lingo-cellulosic fibers are now a day's using as reinforcement in composite materials, also used as an alternative for synthetic fibers. These are environmentally friendly materials used in many applic ations like engineering, space, construction, sports etc. In the present study, a new lingo-cellulosic fiber extracted from Hardwickia Binata was reinforced with epoxy for fabricating composite material. Studies on mechanical, degradation temperatures and features of the uniaxial cellulosic alkali treated Hardwickia Binata fibers were carried out. Hardwickia Binata fiber (HBF) reinforced epoxy composites were prepared varying fiber loading (0, 5, 10, 15 and 20%). Increase in the tensile strength and degradation temperatures are observed with increase in the fiber loading. The increased characteristics are towards the removal of the amorphous cellulose after cleaning with alkaline solution. Degradation temperatures of the fiber focuses towards the applications of car bumpers, automobile parts etc. [ABSTRACT FROM AUTHOR]

Polylactic acid (PLA) based shape memory polymer has potential applications in many applications. It attracted research interest in the past five years. However, limited data is available and little is known on the PLA blends, its processing and the shape memory performance. This work attempts to investigate different PLA blends and its properties, with potential as 3D printing filament for producing PLA based shape memory polymer. Blends of a polylactide (PLA) with thermoplastic polyurethane (TPU) were prepared at a blending ratio of 50/50 and 75/25 wt% in an internal mixer. Then the mixtures were extruded through a single-screw extruder (SSE) at processing temperatures ranging from 150°C to 185°C. A number of testing techniques such as differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were performed to characterise the material. The finding shows that the high composition of TPU decreases the energy required to melt the material. The tested material's glass transition temperature and melting temperature ranged from 58°C to 61°C and 153°C to 155°C respectively. These parameters are essential to determine the shape memory performance of a material. [ABSTRACT FROM AUTHOR]

Nowadays it is state of the art to review, assess and solve problems in all phases of an injection molding process by using the injection molding simulation software such as Moldex3D, Moldflow and Sigmasoft. In order to receive good injection molding simulation results, it is necessary to have a correct and complete material properties. The required material properties for the simulation processes of the injection molding include value of heat capacity and thermal conductivity, a viscosity model and its fitted parameters, a pressure-volume-temperature (PVT) model and its fitted parameters. Especially in the injection molding simulation of thermoset materials it requires defining information about a curing model and its fitted parameters. The material properties in the simulation processes of thermosets injection molding are now found in limited sources and are seldom available from data bank of simulation software. This is because the generation of material properties requires comprehensive knowledge not only in the measurement of reactive viscosity and thermal properties, but also in the field of mathematics such as optimization algorithms. In this research, the fitting tool called Thermoset – TU – Fitting tool has been developed by authors to investigate and evaluate the adaptation of different reactive viscosity models and cure kinetics models in the viscosity and curing kinetics characterization of reactive injection molding materials. Consequently, the material properties of some commercial thermoset materials for the simulation processes of reactive injection molding were successful created with the optimal cure kinetics and reactive viscosity model. A remarkable agreement between simulation results and experimental results shows that it is possible to use Thermoset – TU – Fitting tool to generate the material properties for the simulation processes of the reactive injection molding in a reliable and fast way. Thermoset – TU – Fitting tool is now a package available to all the scientific and industrial community through Professorship of Plastics Engineering, TU Chemnitz. [ABSTRACT FROM AUTHOR]

The effects of rice husk silica (RSi) and vinyltriethoxysilane (VTES) content on cure characteristics, mechanical, morphological, and thermal properties of natural rubber (NR) composites were studied. NR is a renewable material that is widely used in a variety of products. In the production of NR products, several fillers may be used to manufacture a product with the desired properties. However, the majority of fillers are non-environmentally friendly and incompatible with rubber. To solve these issues, rice husk ash (RHA) from biomass power plant was used to produce silica for use as a filler and VTES was used as a compatibilizer. The cure characteristics, mechanical, morphological, and thermal properties of NR/RSi composite at various RSi contents (0, 5, 10, and 20 phr) were studied. The optimal RSi content was used to study the effect of VTES content on mechanical, morphological, and thermal properties of NR/RSi/VTES composite. The increasing RSi content improves mechanical and thermal properties of NR/RSi composites with the optimal RSi loading at 20 phr. While the mechanical properties of NR/RSi/VTES composites show the optimal VTES loading at 0.5 phr. [ABSTRACT FROM AUTHOR]

Buildings account for almost 40% of total energy use, in the European Union. Energy losses in this sector should be reduced. To reach this, thermal insulation of buildings is a key solution. Polystyrene insulations are ordinary, and their thermal properties are well known. However, the most promising type is the graphite enhanced one with relatively less information. These graphite doped material products have much better thermal insulation properties than the conventional (white) ones. This paper will present measurements of sorption isotherms, combined with kinetic vapour experiments performed in a climatic chamber. Based on the results, the identification of the sorption isotherm will be shown. Moreover, the other scope of the paper is to apply a theoretical model used for diffusion after immersion to calculate the vapour diffusion in the samples treated in a climatic chamber. Furthermore, grain size analysis will be executed from microscope images, too. [ABSTRACT FROM AUTHOR]

The global production of fired ceramic bricks represents a large environmental burden in form of energy consumption and greenhouse gasses emission. The production process has therefore become an object of interests of several studies aiming at its optimization to reduce the negative environmental impacts. Within these optimizations, the precise knowledge of thermal properties of clays undergoing the firing process is one of the key information that conditions the successful solution of the problem. This paper therefore aims at determination of temperature-dependent thermal conductivity of clays. Using a set of thermocouples, the temperature distribution in the sample is monitored, being exposed to one-sided heating. The temperature field deformation due to presence of metal wires is then overcame using computational modelling that is able to distinguish the particular contributions of clay/thermocouples to the ongoing heat transfer. Based on this assumption, such a thermal conductivity of clay is then sought, that provides the same temperature distribution as the experiment. The thermal conductivity values of clays were found to range between 0.58 W·m−1·K−1 and 1.97 W·m−1·K−1, depending on the temperature. [ABSTRACT FROM AUTHOR]

Cement composites exposed to high temperatures change their microstructure, composition and properties. In different temperature ranges, various physical and chemical processes take place in both their matrix and aggregates, which significantly affect the heat and mass transfer parameters, as well as the strength characteristics. In this paper, the effect of plasticizers on thermal properties of heat resistant composites based on calcium aluminate cement is studied. Thermal conductivity, specific heat capacity, and thermal strain are determined as a function of thermal load and compared with a reference material. The experimental results show that for the analyzed composites modified carboxylate is the most convenient choice while melamine-formaldehyde resin is found unsuitable. [ABSTRACT FROM AUTHOR]

In order to analyze the structural properties of the HgBa2Ca2Cu3O8+δ sample, X-ray diffraction was used. To determine the type of crystal structure, the results showed that the compound has a tetragonal crystal structure. The crystal lattice constants (a, b, c) were calculated with obvious differences in the crystal lattice properties. The crystal size was calculated by four different methods (Scherrer, Williamson-Hall, Halder-Wagner and size-strain plot), which showed the best result using the (Halder-Wagner) method, where the crystal size (C.S=22.27 nm) and determination coefficient (R=0.9903), which is the best method among the four methods for preparing this compound. The titration method of the samples (HgBa2Ca2Cu3O8+δ) was used to find out the percentages of oxygen content (δ) and it was found that the oxygen content was (δ=0.269). And by using the four probes method to determine the transition temperature, it was found that the transition temperature (Tconset) is equal to (147K), where the electrical resistance begins with a strong gradient and becomes zero at the critical temperature (Tcoffset = 128K). The thermal properties were studied using the(Lee's disk) method, the results showed that the thermal conductivity of the sample decreases whenever the temperature is applied to it, as the compound is characterized by a thermal curve that begins to show thermal conductivity at (0.12945) at temperature (313K) and the curve decreases to (0.09888) at temperature (553K). The dielectric properties of the compound were examined using a device (LCR counter) which included: dielectric constant (real and imaginary), loss factor and alternating electrical conductivity, the dielectric properties were studied as a function of frequency and range (50 Hz) to (1 MHz) at room temperature. [ABSTRACT FROM AUTHOR]

The present paper includes the fabrication of Al7075-Mica-Kaolinite HMMC with various reinforcement ratios (i.e., Mica (0%, 3%, 5%, 7%, 9% wt%) and Kaolinite (0%, 3%, 5%, 7%, 9% wt%) respectively by using Stir casting method. The work operations performed on the fabricated specimen are Thermal conductivity testing, Microstructure Analysis, and Wear behavior. After analyzing the specimen under various tests, a conclusion was made. Theresult of the Metallurgical microscope reveals that the average grain size decreases as the reinforcement ratios increase. We observed that the wear rate and coefficient of friction increase by load and decrease by an increase in reinforcement in both dry and wet conditions. [ABSTRACT FROM AUTHOR]

The concept of using solid particles as heat transfer and storage medium has drawn interest in recent years with the advantages over the existing technologies. However, the behavior of particles in the commercial systems should be predicted beforehand, which can be modeled with DEM accurately. This study focuses on investigating mechanical interaction and thermal properties of sintered bauxite and sand particles that are input to DEM models of heat transfer and storage systems. Direct measurements and calibration approaches were utilized together to obtain the mechanical interaction properties of particles. A resultant mechanical interaction parameter set including rolling and sliding friction coefficients and restitution coefficients between particles and particles and metal boundary for sand and sintered bauxite particles is presented. It is found that rolling and sliding friction coefficients between particles and wall does not show apparent difference depending on particle type. However, the rolling friction coefficient between sand particles is higher than sand sintered bauxite particles which can be explained by the shape effect. The interparticle sliding friction coefficient of sand particles is lower than sintered bauxite particles, which proves that the sliding friction coefficient is not related to the shape effect but the material itself. Sintered bauxite particles have higher interparticle and particle-wall restitution coefficients than sand particles, which is coherent with previous experimental results and observations. Effects of thermal cycling and high temperatures on mechanical interaction properties were examined. Hot Disk measurement equipment was used to validate the available data of temperature-dependent thermal properties of examined particles. Measurement results obtained in this study show a maximum 10.45% deviation from the available results in the literature. Sensor bias of the measurement equipment, which occurs at high temperatures, was corrected. [ABSTRACT FROM AUTHOR]