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Researchers have used nanomaterials as additives in base oil to improve its specifications, especially to minimize wear and friction during its applications. In this study, calcium carbonate (CaCO3) nanoparticles were selected as an additive to serve as a protective layer between components and anti-wear properties. In this study, calcium carbonate (CaCO3) nanoparticles were selected as an additive to serve as a protective layer between components and anti-wear properties. Nano lubricant samples were prepared using mass variations of CaCO3 and SAE 10W-30 base oil with concentrations of 0.05, 0.1, 0.15, and 0.2%, then homogenized. The nanolubricant samples obtained were analyzed for thermophysical, rheological properties and lubricant performance with the addition of nano CaCO3 in improving the wear resistance of FC25 cast iron. The results of thermophysical and rheological properties analysis suggest that the nanolubricant has better tribological properties compared to base lubricants. The highest values of thermal conductivity, density, and viscosity (40 °C) are 0.139 W/m.K, 812.203 kg/m³, and 106 mPa.s (40 °C). Meanwhile, the highest CoF, disc mass loss, and surface roughness of nanolubricant are 0.0706, 0.0037 grams, and 0.50 µm, respectively. These results indicate that the greatest wear-reducing agent is from the nanolubricant with the addition of CaCO3 nanopowder additives at 0.1 wt% concentration. These results are expected significant insights into the advancement of nano technology-based lubricants in the future. [ABSTRACT FROM AUTHOR]

This paper shows experimental study results on the thermophysical and stability of nanofluids of Titanium oxide (TiO2) dispersed in high-purity of Virgin Coconut Oil (VCO). Nanofluid samples that functioned as a lubricant were prepared by a two-step preparation method at different volume fractions (0.1, 0.3, and 0.5 vol.%) and different temperatures (28, 40, and 100°C). The dynamic viscosity and density were performed using Falling Ball Viscometer and Pycnometer, respectively. The sedimentation photograph method using a digital camera was applied to analyze the stability. A maximum dynamic viscosity enhancement of 62.78% was recorded for TiO2/VCO nanofluid with 0.5% nanoparticle volume fraction and at the temperature of 100°C). Whereas, the highest density improvement was recorded for TiO2/VCO nanofluid with 0.5% nanoparticle volume fraction. Freshly prepared nanofluids did not show any significant change in stability. However, a trivial phase separation appeared in the samples after 8 days. The results indicated that adding TiO2 nanoparticles increased the dynamic viscosity and density. It can be concluded that the volume in fraction has the effect to enhance the thermophysical stability of TiO2/VCO nanofluids.

While IN738 Ni-based superalloy is a high strength alloy, it is feasible to improve its properties at the bulk level by reinforcing with graphene nanoplatelets (GNPs), taking advantage of the superior mechanical, tribological and thermal properties using the spark plasma sintering technique. In the present study, the influence of spark plasma sintering temperature range between 900 and 1100 °C on the microstructure, mechanical, tribological and thermophysical properties of GNPs/IN738 composite is assessed. The dispersion of GNPs reinforcement and alloying metals to form composite powder is conducted using a turbular mixer and low-frequency planetary ball milling, followed by spark plasma sintering. The relative density of the sintered samples assessed following Archimedes' method indicates increasing densification with the increasing sintering temperature from 94.7% (900 °C) to 98.5% (1100 °C). The microstructure assessed via SEM, XRD and Raman spectroscopy indicates the formation of precipitate gamma, intermetallic gamma prime, solid solution and GNPs strengthening phases. Thus, the mechanical (micro/nano hardness and Young's modulus), tribological (wear rate and coefficient of friction), and thermophysical (thermal diffusivity, thermal conductivity, and specific heat capacity) properties increased with the increasing sintering temperature. The microhardness increased from 354HV (900 °C) to 469HV (1100 °C), nanohardness from 8 GPa (900 °C) to 17 GPa (900 °C), and Young's modulus from 190 GPa (900 °C) to 291 GPa (1100 °C). The wear rate reduced with an increase in sintering temperature for the three loads of 5, 10 and 20N. The thermophysical properties assessed from 25 to 600 °C show the formation of few inflection points as the temperature increases, which is attributed to the dissolution and rearrangement of precipitate gamma prime and Cr in solid solution phases. Similarly, the small increment in the thermal diffusivity is equally associated with the smoother phonon transition at the GNPs/matrix interface.

The specific heat capacity plays a crucial role in influencing the heat transfer efficiency of materials. Considering the relatively low specific heat capacity of metals, this study focuses on investigating the impact of second-phase nano Ni particles on the microstructure and thermophysical properties of the alloy matrix. The alloys' phase compositions and microstructures were examined using X-ray diffraction phase analysis (XRD), electron probe micromorphology analysis (EPMA), and X-ray fluorescence spectroscopy (XRF). Furthermore, the thermophysical properties of the alloys were comprehensively analyzed through the employment of a differential scanning calorimeter (DSC) and the laser flash method (LFA). The addition of second-phase nanoparticles significantly increased the specific heat capacity of the alloy in the liquid state; however, the phenomenon of nanoparticle agglomeration diminishes this improvement. The analysis of the specific heat enhancement mechanism indicates that ordered states are formed between the second-phase solid nanoparticles and the melted metal in the liquid state. With the increase in temperature, the destruction of these ordered states requires additional heat, resulting in the increase of specific heat capacity. [ABSTRACT FROM AUTHOR]

The study explored the thermal insulation potential of composite material made from clay and Luffa cylindrica. Clay/ Luff cylindrica composite (denoted as Clay/L-C) was developed from natural resources. In the research, Luffa cylindrica particles of different grain sizes and different proportions were mixed with clay, and thermal evaluations were done with respect to thermal conductivity, thermal diffusivity, specific heat capacity, mass depletion with temperature, and microstructure. Two different mixture ratios, namely 4:1and 3:2 corresponding to 20 wt % and 40 wt % Luffa cylindrica particle, respectively, were used for Clay/ Luffa cylindrica combination. While Luffa cylindrica particle sizes varied from 600µm to 300µm and 150µm, the effects of Luffa cylindrica content and particle size on thermal properties were then examined. These novel composite materials developed in this study demonstrate motivating potential for enhanced thermal insulation when compared to unmodified clay. Improved thermal insulation performance indicated by thermal properties was observed for all the modified samples. This is on the account of reduced thermal conductivity of the modified samples. The best sample possessed thermal conductivity, thermal resistivity, thermal diffusivity, specific heat capacity, and porosity values of 0.216 W/mK, 462.90°C.cm/W, 0.123 mm/s2 1.493 MJ/m3K, and 89.3%, respectively. Results show that Luffa cylindrica fiber can be applied as an additive for effective thermal insulation. Development in this area of study is very necessary especially as the raw materials are readily available and cost-effective. [ABSTRACT FROM AUTHOR]

The characteristics of vast dune sands in southern Algeria create the potential for exploitation in high-temperature resistance performances for refractory mortar manufacturing used in building construction. The refractory mortar examined in this work incorporates amounts of fine addition of liquid crystal display glass electronic waste (DGE-waste) in order to optimize the thermophysical and mechanical performance of the mortar and correct the granular distribution of the used sand. The aim of this paper is to study new refractory mortar products containing DGE-waste to reduce the demand for conventional mortars while providing a new sustainable waste management solution. The dune sand was partially substituted (0 %, 5 %, 10 %, 15 %, and 20 % in weight) with DGE-waste powder with a w/c ratio of 0.6. The DGE-waste powder and four of the five samples were analyzed using a scanning electron microscope (SEM). The thermophysical properties, such as thermal conductivity, were experimentally measured in dry states. These properties were determined as a function of the DGE-waste powder percentage using a high-temperature oven at different temperatures (200 °C, 400 °C, 600 °C, and 800 °C), whose mechanical behavior at high temperatures has not been extensively studied. We statistically analyzed the obtained data using one-way analysis of variance (ANOVA) with a level of significance of 0.05. The results confirm that increasing the replacement levels of additions of DGE-waste significantly improves the thermo-physical and thermo-mechanical properties of dune sand-based mortar. As a result, the results show that thermal conductivity decreases with increasing temperature and/or decreased replacement rate. Therefore, the incorporation of DGE-waste powder can significantly affect the thermophysical and thermomechanical properties as compared with the control mortar. The results revealed that a more reasonable way to find refractory dune sand mortar is by incorporating DGE-waste. [ABSTRACT FROM AUTHOR]

The thermophysical properties of 1A2P (1-amino-2-propanol) (1) with AAc (methyl acetate (MAc) or ethyl acetate (EAc) or propyl acetate (PAc) or butyl acetate (BAc)) (2) were examined for understanding the molecular interactions between given binary liquid mixtures. Viscosity (η) was measured for 1A2P, AAc (alkyl acetate) and their binary mixture at five different temperatures (T = 298.15 to 318.15 K) and at 0.1 MPa pressure. From η data, the deviation in viscosity, Δη, and excess Gibbs free energy of activation, G∗E, were calculated. The Δη values were more positive for the 1A2P (1) + MAc (2) binary mixture at equimolar composition which indicate that there is strong intermolecular interaction between 1A2P and MAc molecules. Further, Δη values were also analyzed by Graph theoretical approach (GTA) and predicted that CO-----H-O interactions are stronger than OH----O-C interactions between 1A2P and AAc molecules in the liquid mixture which is also recognized by FTIR spectroscopic studies. Density functional theory (DFT) studies were employed to investigate the strength of molecular interactions.

The present paper aims to study the thermophysical and physicochemical properties of CaO-CaF2-SiO2-22.5% TiO2 based electrode coating for welding the components of advanced ultra-supercritical power plants. The mixture design methodology was used to formulate thirteen coating mixtures to explore the effect of flux coating properties, i.e., density, change in enthalpy, weight loss, thermal conductivity, specific heat, and thermal diffusivity. Flux coating properties play an essential role in achieving better weldments. Fourier transformation and X-ray diffraction were used to analyze electrode coating composition structural behavior. The coating composition was also characterized by using a thermogravimetric analyzer and hot disc apparatus, and after that, a regression model analysis was carried out to study individual, and their interaction effects on the thermophysical and physicochemical properties. CaO.CaF2, CaO.SiO2, and CaF2.SiO2 is the most effective binary mixture which has an increasing effect on density. The weight loss of coating observed during thermogravimetric analysis is affected by individual constituents significantly. The binary interaction of SiO2.CaO and CaF2.SiO2 is the most favorable and has an increasing effect on weight loss. Individual components affect change in enthalpy significantly. The binary interaction of CaO.SiO2 and CaF2.SiO2 is the most effective and has an increasing effect on change in enthalpy. The thermal properties of coating composition observed during hot disc are affected by individual and binary mixture constituents. Binary mixture CaF2.CaO and CaF2.SiO2 is having an increasing effect on thermal conductivity. Binary mixture SiO2.CaO shows a decreasing impact on thermal diffusivity. Binary mixture constituents CaF2.CaO, SiO2.CaO is the most effective and has an increasing effect on specific heat. [ABSTRACT FROM AUTHOR]

The development of coffee bean porosity during roasting was captured for a Kenyan Arabica coffee roasted under different constant inlet air temperature conditions in a pilot-scale spouted bed roaster. Coffee bean porosity was characterised using X-ray Micro Computed Tomography (Micro-CT). These data demonstrated a significant increase in coffee bean porosity of up to 60% during roasting. The coffee's intrinsic physical properties were also analysed to identify the relationship between porosity, thermophysical properties (density, thermal conductivity, specific heat capacity) and common process indicators (colour, mass, moisture, volume). Implications for heat transfer during roasting are also discussed. As Micro-CT, pycnometry and thermal properties analysers are not readily available tools, correlation of costly analytical methods with rapid discriminative tests are presented, allowing developers to utilise more accessible characterisation techniques to inform modulation of their processes and products. The data-driven approach to map coffee's physicochemical development during roasting provides comprehensive data that could be used to calibrate mechanistic or kinetic models. These physics-driven models could then be used as routine equations nested in heat and mass transfer simulations for developers to predict coffee's thermal evolution and subsequent physical transformation during roasting. [ABSTRACT FROM AUTHOR]

The specific heat capacity plays a crucial role in influencing the heat transfer efficiency of materials. Considering the relatively low specific heat capacity of metals, this study focuses on investigating the impact of second-phase nano Ni particles on the microstructure and thermophysical properties of the alloy matrix. The alloys’ phase compositions and microstructures were examined using X-ray diffraction phase analysis (XRD), electron probe micromorphology analysis (EPMA), and X-ray fluorescence spectroscopy (XRF). Furthermore, the thermophysical properties of the alloys were comprehensively analyzed through the employment of a differential scanning calorimeter (DSC) and the laser flash method (LFA). The addition of second-phase nanoparticles significantly increased the specific heat capacity of the alloy in the liquid state; however, the phenomenon of nanoparticle agglomeration diminishes this improvement. The analysis of the specific heat enhancement mechanism indicates that ordered states are formed between the second-phase solid nanoparticles and the melted metal in the liquid state. With the increase in temperature, the destruction of these ordered states requires additional heat, resulting in the increase of specific heat capacity.

The aim of this study is to investigate the physicochemical and thermophysical properties of CaO–TiO 2 –SiO 2 –Na 3 AlF 6 based electrode coating developed for the welding of advanced ultra-supercritical (AUSC) thermal power plant components. The extreme vertices approach has been used to create twenty-six electrode coating compositions. Various physicochemical and thermophysical properties were characterized using experiments. The coating properties are essential in ensuring sound weld with desirable in-service performance. The developed coating's structural behavior was analyzed using Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD). In addition, regression analysis was carried out to evaluate the influence of coating constituents. Individual constituents and their interaction were found to have a prominent role in influencing the physicochemical and thermophysical properties. [ABSTRACT FROM AUTHOR]

Thermal cycling can reduce or eliminate thermal stresses in aluminum matrix composites, which is essential to improve the dimensional stability of the composites. In this work, the effect of thermal cycling process on the thermophysical properties of 6092 aluminum alloy/silicon carbide/zirconium tungstate composites was investigated by combining response surface optimization and multi-objective genetic algorithm. The purpose is to elucidate the effects of the process of heating temperature, heating time and cycles on the coefficient of thermal expansion (CTE), micro-strain and thermal conductivity of the composites. A series of robust response models were proposed and verified using analysis of variance, externally studentized residuals distribution and the predicted residuals distribution. According to these models, the heating temperature, heating time and cycles interact in a nonlinear manner concerning on thermophysical properties. The experimental results confirmed that thermal cycling can effectively reduce or eliminate thermal residual stresses in the composites and induce the phase transformation process of zirconium tungstate. The heating temperature plays a dominant role in promoting the thermal mismatch stress release between the metal matrix and the reinforcing particles. The Pareto-optimal hypersurface results on the response surface were obtained according to the non-dominated sorting genetic algorithms (NSGA-II), indicating that the optimal thermal cycling processes were 200 °C, 2 h and 3 cycles with corresponding CTE, micro-strain and thermal conductivity of 20.55 × 10–6/K, 1.16 × 10–3 and 116.68 W/(m K), respectively. [ABSTRACT FROM AUTHOR]

The results obtained from the exergoeconomic and exergy analysis of a model of a generic air conditioning (A/C) system without and with an air membrane exchanger using three commercially available refrigerants: R410A, R407C, and R134a, are reported. The model used specialized software that was validated against recently published data and showed good agreement. A/C systems are energy intensive and consume a significant portion of global electricity. Improving their efficiency by even a small amount will produce considerable savings, reduce running costs, and lower pollution emissions. The efficiency of the same A/c system without and with a membrane was investigated for different ambient temperatures, relative humidities (RHs), and pressure ratios of the compressor. It was shown that the inclusion of a membrane improved the efficiency of the system for all three refrigerants tested, particularly at higher ambient temperature. Both the coefficient of performance and exergetic efficiency reduced with the increase in the pressure ratio due to increasing fuel exergy and losses. In all system components except one, it was found that the source of the cost is inefficiencies; hence, increasing the efficiency at the expense of the non-exergy cost will improve the cost effectiveness of the entire system. [ABSTRACT FROM AUTHOR]

Nanofluids and hybrid nanofluids containing nano-sized metal oxide particles are known to perform better in terms of thermal conductivity when used as working fluids in thermal systems. The thermal and physical properties of working fluids are important parameters in the solution of many heat and flow problems. In this study, the thermophysical properties of nanofluids obtained by adding certain ratios to the pure water such that CuO, ZnO, MgO particles and CuO + ZnO, MgO + CuO, MgO + ZnO hybrid particles are nano-sized were determined theoretically using the models in the literature. Thermal conductivity, specific heat, viscosity values of nanofluids with different concentrations such as 0.5%, 1%, 2% and 2.5% were calculated and the models were compared.

• Measured ρ , η , u and n D of 1-propanol (1) + 1,3-diaminopropane (2) + ethyl acetate (3). • Evaluated V m E , Δ η , Δ u , k s E , V f E , L f E , V a E and Δ n D from the measured properties. • V m E data analyzed in terms of Singh, Nagata and Cibulka equations. • u data analyzed by Schaaff's collision factor theory (CFT) and Jacobson's free length theory (JFLT). • Analyzed data were interpreted in terms of molecular interaction. In the present report, density (ρ), viscosity (η), speed of sound (u) and refractive index (n D) of ternary liquid mixture containing 1-propanol (1P) (1) + 1,3-diaminopropane (1,3-DAP) (2) + ethyl acetate (EAc) (3) were measured at five different temperatures (T = 298.15 to 318.15 K) and at 0.1 MPa pressure. Data of ρ , η , u and n D were used to compute the excess molar volume, V m E , deviation in viscosity, Δ η , deviation in ultrasonic speed, Δ u , excess isentropic compressibility, k s E , excess free volume, V f E , excess intermolecular free length, L f E , excess available volume, V a E , and deviation in refractive index, Δ n D , and these computed physicochemical properties were fitted to Singh equation. The V m E data were fitted to the Nagata and Cibulka equations. Further, Kohler model, Tsao-Smith model, Radojkovic model, Jacob-Fitzner model and Rastogi model were used to calculate the V m E values. The speed of sound data was analyzed by various correlations such as Van Dael, Nomato, Impedance dependence, Schaaff's collision factor theory (CFT) and Jacobson's free length theory (JFLT). Various correlations like Heller, Arago-Biot, Lorentz-Lorenz, Erying, Newton, Gladstone-Dale, and Weiner were used to correlate n D data. [ABSTRACT FROM AUTHOR]

The carbon fibers-diamond (50 vol%)/ Al composite (CFs-D/Al) was successfully designed and fabricated using gas pressure infiltration. By comparing it to the carbon fiber/Al composite (CFs/Al), a dual reinforcement structure with both soft and hard materials was formed, resulting in improved anisotropy. This improvement can be attributed to the high hardness of diamond (D), which bears most of the pressure during infiltration. The thermal conductivity (TC) of the CFs-D/Al in the XY plane and Z direction were measured to be 249.97 W·m−1·K−1 and 225.81 W·m−1·K−1, respectively. These values represent a 27.24% and 133.2% increase in TC compared to CFs/Al. The improved anisotropy, excellent TC of diamond, high density, and good interface are the main factors contributing to this enhancement in thermal conductivity. Additionally, CFs-D/Al demonstrated acceptable coefficients of thermal expansion (CTEs) of 7.26 × 10−6 K−1 (in the XY plane) and 10.04 × 10−6 K−1 (along the Z direction). This is mainly attributed to the low CTE of carbon fibers and diamond, as well as the presence of good interfacial pinning and residual stress in the composite. Furthermore, the addition of carbon fibers greatly reduced the wear of cutting tools compared to D/Al. The surface roughness of the CFs-D/Al after machining was measured to be 5.939 μm, which is 51.86% and 70.97% lower than that of CFs/Al and D/Al, respectively. This reduction in surface roughness can be attributed to the lubricating effect of CFs and the ability of D to prevent peel pits under the adhesive wear mechanism. This research utilized the design concept of combining the advantages of different reinforcements to surpass the limitations of using a single reinforcement for heat dissipation purposes. [Display omitted] • A new Al matrix composite with CFs and D double reinforcements was designed and prepared. • The combination of CFs and D improves the disadvantages of single reinforcement in thermophysics and machinability. • The TC of CFs-D/Al on the Z direction is 225.81 W·m-1·K-1, improving by 133.20%, compared with CFs/Al. • Compared with CFs/Al and D/Al, the surface roughness of CFs-D/Al workpiece after turning is reduced by 51.86% and 70.97%, respectively. [ABSTRACT FROM AUTHOR]

The flammability and explosiveness are the disadvantages of the application of R290 practically as an alternative refrigerant of R22. However, adding flame‐retardant R1234ze(E) to R290 can make up for those shortcomings. The refrigerant mixture R290/R1234ze(E) with mass ratio 55%:45% (coded RC01) was proposed to replace R22. The data of RC01 were obtained by calculating using the refrigerant software REFPROP9.1. The environmental impact indexes, temperature glide characteristics, thermodynamic and thermophysical properties, theoretical thermodynamic cycle performances, safety, and lubrication properties of RC01 were analyzed and compared with that of R22, R410A, R407C, R290, R1234ze(E), respectively. The results show that the RC01, with the ozone depletion potential of 0 and global warming potential of 12, is a near‐azeotropic refrigerant whose glide temperature is approximately 0, and it has better thermodynamic and thermophysical properties as well as theoretical thermodynamic cycle performances. The RC01 also has good lubrication characteristics and low flammability. So it is technically feasible to replace R22. [ABSTRACT FROM AUTHOR]

In this work, a series of polysulfide polymers were synthesized using organic monomer (ethylene dichloride) and sodium-based aqueous monomers via interfacial polymerization. The structural characteristics of aqueous monomers and synthesized polysulfide polymers were identified by Fourier transform infrared (FT-IR), Raman, and ultraviolet–visible-near infrared (UV–VIS-NIR) spectroscopies. The Optimum temperature of polymerization was obtained at 75°C. Benzyltriethylammonium chloride (BTEACl) and tetrabutylammonium bromide (TBAB) were used as phase transfer catalysts (PTC) where BTEACl showed better performance regarding the polymerization yield. Moreover, adding ethanol to polymerization media increased the polymerization yield significantly. The results showed that along with increasing sulfur in the structure of polymers, solubility and flexibility were increased whereas it decreased the hardness, melting point (Tm) and glass transition temperature (Tg) of obtained polymers. [ABSTRACT FROM AUTHOR]

This paper investigates the thermophysical, physicochemical, and surface properties of mineral waste red ochre, assessing suitability for application in welding consumable development. Red ochre is an anhydrous iron oxide derived from tailings of iron ore haematite. High iron and silica concentration makes it suitable for various engineering applications. Iron in the electrode coatings is known to increase arc stability, bead smoothness, and also it enhances slag detachability along with smoothening bead profile. The red ochre has been characterized for the properties of weight loss, density, specific heat, enthalpy, thermal conductivity, and diffusivity. Structural analysis of red ochre powder has been done using Fourier transformed infrared spectroscopy and X-ray diffraction. BET (Brunauer, Emmett, and Teller) surface area analysis has been done to estimate the surface properties, which include pore radius and specific surface area. The shielded metal arc welding electrodes have been developed by adding red ochre in a fixed proportion, and produced welds have been examined for visual defects, microstructure, and microhardness. [ABSTRACT FROM AUTHOR]

The present research investigates on task-specific deep eutectic solvents (TDES) based aqueous two-phase extraction and purification of immunoglobulins by chromatography from quail egg. The synthesis of TDES was accomplished with quaternary ammonium salt as hydrogen bond acceptor (HBA) and glycerol as hydrogen bond donor (HBD). Aqueous two-phase (ATPS) formation of TDESs with various salts was established and phase partitioning ability was evaluated using standard bovine immunoglobulin. Ultrasound-assisted liquid-liquid microextraction (UA-LLME) was performed with ATPS of better partitioning ability for quail egg yolk. Optimization of influential variables with response surface methodology was accomplished and maximum yield was achieved for 85% (v/v) of NADES for feed of 18 μg/ml of egg yolk isolate with ultrasound temperature of 35 °C and 12 min contact time respectively. The quantification of recovery was accomplished by gel filtration process with the determination of retention time, volume and resolution of separation using marker protein. Ultrapure immunoglobulin-Y (IgY) is achieved with anion exchange chromatography and yield was calculated. The results revealed that the selective concentration of immunoglobulin-Y from quail egg yolk could be performed using environment-friendly TDES based UA-LLME coupled with chromatography. • Five ammonium ionic liquid based HDES were synthesised at lowest possible molar ratio. • Thermophysical derogation of synthesised HDES was evaluated. • Ultrasonic assisted liquid-liquid ternary micro extraction was developed. • High partition coefficient of Reactive Yellow 135 was obtained. • Thermodynamic efficiency of extraction estimated and Gibb's free energy of phase transfer was calculated. [ABSTRACT FROM AUTHOR]

This paper presents a methodology that can be used to consider local variations in thermomechanical and thermophysical material properties, residual stresses, and strength-differential effects in finite element analyses of cast components. The methodology is based on applying process simulations and structural analyses together with experimentally established, or already available literature data, in order to describe element-specific material variations. A cast-iron cylinder head was used in order to evaluate the influence of several simplifications that are commonly performed in computer aided engineering. It is shown that non-trivial errors of a potentially large magnitude are introduced by not considering residual stresses, compressive behaviour, temperature dependence, and process-induced material property variations. By providing design engineers with tools that allow them to consider the complex relationships between these aspects early in the development phase, cast components have the potential to be further optimized with respect to both weight and performance. [ABSTRACT FROM AUTHOR]

• Measured viscosity (η) of 1,2-diaminopropane (1) + alkyl acetate (MAc or EAc or PAc or BAc) (2). • Evaluated Δ η and G ∗ E from the measured η data. • The Δ η values were interpreted by Bloomfield and Dewan model and Graph theoretical approach. • The η values were correlated with various correlations. • Data obtained interpreted qualitatively in terms of intermolecular interactions. The liquid mixtures are used as a solvent in most of the natural systems and chemical processes. Therefore, the physicochemical properties of liquid mixtures at different compositions and at different temperatures have a significant role in the optimization of chemical processes. In the present report, the dynamic viscosity (η) of 1,2-DAP (1,2-Diaminopropane) (1) with AAc (alkyl acetates) (C 1 -C 4) (2) were measured at different temperatures (T = 298.15 to 318.15 K) at pressure 0.1 MPa. Deviation in dynamic viscosity, Δ η , and excess Gibbs free energy of activation, G ∗ E , for these binary mixtures were calculated from measured dynamic viscosity data and fitted to Redlich-Kister polynomial equation (R.K.). Δ η data were examined in terms of the Bloomfield and Dewan (BFD) model and Graph theoretical approach (GTA) to study the intermolecular interactions in binary mixtures. Further, different correlation like Hind-McLaughlin-Ubbelohde, Bingham, Arrhenius, Kendall, Heric-Brewer, Kendall-Monroe, Tamura-Kurata, Lulian, Grunberg-Nissan, Krishnan-Laddha Frenkel, Katti-Chaudhari, Heric and McAllister were used to correlate η values. [ABSTRACT FROM AUTHOR]

• Measuredρ,η, n D and u of water + amines binary liquid mixtures at T= 298.15–318.15 K. • Evaluated V m E , Δη, Δ n D , uE and k s E from the measured data. • The V m E and Δη values were interpreted by Graph theoretical approach. • The η and n D values were correlated with various correlations. • IR analysis results predicted the OH—NH as probable intermolecular interactions. Liquid mixtures are used as a solvent in most of the natural systems and chemical processes. Therefore, the physicochemical properties of liquid mixtures at different compositions and at different temperatures have a significant role in the optimization of chemical processes. The present report involves the analysis of the thermophysical properties of water (1) and amines (2). Density, ρ, dynamic viscosity, η, refractive index, n D , and speed of sound, u , data were measured for binary mixtures of water (1) and amines (1A2P (1-amino-2-propanol), 1,2-DAP (1,2-diaminopropane) and 1,3-DAP (1,3-diaminopropane) (2) at five different temperatures (T = 298.15 to 318.15 K) and at 0.1 MPa pressure. Based on experimental data, the excess molar volume, V m E , deviation in dynamic viscosity, Δη, excess Gibbs free energy of activation, G * E , deviation in refractive index, Δ n D , excess ultrasonic speed, uE , excess isentropic compressibility, K s E , deviation in free volume, Δ V f , excess available volume, V a E , and excess intermolecular free length, L f E , were calculated and these evaluated properties were fitted to Redlich-Kister polynomial (R.K.). The V m E data was analyzed by Prigogine-Flory-Patterson (PFP) theory. The dynamic viscosity, η, values were studied by different correlations. The V m E and Δη data were also analyzed by Graph theoretical approach (GTA). Raman and FT-IR spectroscopic studies give important information about the intermolecular interactions present between unlike molecules water (1) and amines (2) which is also recognized by GTA. The value of V m E and K s E values were found negative over the whole composition range, and it follow the sequence as: 1,2-DAP > 1,3-DAP > 1A2P with water at equimolar composition. GTA and PFP well supported the V m E data. GTA studies help in investigating the specific intermolecular interactions between unlike components. Further, Graph theory studies predicted OH—–NH interaction is dominant interaction among all interactions which were also supported by Raman and FTIR spectroscopic studies. [Display omitted] [ABSTRACT FROM AUTHOR]

Refrigerated transport and storage of mango fruit are essential to maintain quality, reduce food waste and the associated embodied energy losses. Refrigeration is also key to enable successful transcontinental export to distant markets. To minimize the environmental impact of the cold chain and to optimize logistics, a better knowledge of the fruit quality evolution within individual shipments would be extremely valueable. For this purpose, a digital fruit twin is developed, based on mechanistic modeling. This digital twin simulates the thermal behavior of mango fruit throughout the cold chain, based on the measured environmental temperature conditions, namely the air temperature in the vicinity of the fruit. At the same time, the evolution of associated quality attributes, due to enzymatically-driven, temperature-dependent biochemical degradation reactions, is quantified. Also, a biophysical counterpart of real mango fruit – an innovative fruit simulator sensing device – was developed and used for model validation of fruit pulp temperatures. We identified – in-silico – the impact of the unique delivery air temperature history and cold chain length on fruit quality evolution for actual maritime vs. airfreight transport pathways. Digital twins were found to provide complementary insights in the thermophysical behavior of fruit, particularly in supply chains of very perishable species, and for storage at low airflow rates. Such mechanistic modeling enabled to understand, record, and predict where temperature-dependent fruit quality loss occurs in each supply chain. In that way, digital twins can help to improve refrigeration processes and logistics to reduce food losses, thereby making the refrigerated supply chain greener. [ABSTRACT FROM AUTHOR]

Due to renewed interest in uranium silicide compounds as a candidate for nuclear reactor fuels, there is a need for extensive investigations of their thermophysical properties as a function of temperature. In this work, we calculate the thermophysical properties of the U 3 Si 2 compound within the framework of molecular dynamics (MD) using a semi-empirical modified Embedded-Atom Method (MEAM) potential and density functional theory (DFT). Thermal expansion, thermal conductivity, heat capacity, and elastic properties are presented as a function of temperature from 300 to 1800 K. The thermal conductivity of U 3 Si 2 increases with temperature due to the electronic contribution while the phonon contribution decreases with increasing temperature. The phonon contribution to the thermal conductivity at 300 K is estimated at 2.03 W/mK and 1.41 W/mK using non-equilibrium molecular dynamics (NEMD) and equilibrium molecular dynamics (EMD), respectively. The electronic contribution is estimated to be 8.56 W/mK using the semi-classical Boltzmann transport theory at 300 K. Furthermore, we compared the thermal conductivity in two different crystallographic directions to shed light on the spatial anisotropy using NEMD and EMD methods. The inherent anisotropic thermophysical properties can be used to parametrize phase field models to incorporate anisotropic thermal conductivity and thermal expansion, allowing for a more accurate description of microstructural evolution under variable temperature and irradiation conditions. [ABSTRACT FROM AUTHOR]

The mixing behaviour of Cd-Tl, In-Tl and Sn-Tl liquid alloys have been examined using formalism that relates viscosity and chemical diffusion with thermodynamic properties. We found that the atomic interactions in these systems are weak; Cd-Tl has the weakest atomic interactions, while the interactions in Sn-Tl are weaker than in In-Tl. Also, the systems exhibit weak homocoordination tendency; Cd-Tl is the most homocoordinated when C, while Sn-Tl is the most homocoordinated when C. Additionally, enthalpic and entropic effects significantly influenced the viscosity of Cd-Tl in the entire thallium composition but only influenced the viscosities of In-Tl and Sn-Tl in some thallium compositions. Furthermore, the atomic size difference has the most pronounced effect on the viscosity of Cd-Tl, while it has more effect on the viscosity of In-Tl than on the viscosity of Sn-Tl. This study provides useful insight on the structure and binding in three thallium-based alloys. [ABSTRACT FROM AUTHOR]

The NiFe2O4 magnetic nanoparticles synthesized and used to prepare stable water-based magnetic nanofluids of various concentrations by ultrasonically assisted two-step techniques. Thermophysical investigations are made on the nanofluids at different temperatures ranging from 20 to 80 °C. The measurements revealed that the thermal conductivity of nanofluids significantly enhances with an increase in the percentage of nanoparticle volume fraction. The thermal conductivity measurements showed that the maximum enhancement is 32.65% achieved at 1% nanoparticle volume fraction and at 80 °C. Specific heat of nanofluids was decreased with increasing nanoparticle volume fractions, and it augments with increasing temperature. Viscosity measurements showed that nanofluid had a Newtonian behavior at all nanoparticle volume fractions and temperatures considered. The viscosity of the nanofluid increased with increasing nanoparticle concentration and decreasing temperature. Experimental results revealed that the viscosity sensitivity to temperature variation is minor, while it is more sensitive to the variations of nanoparticle volume fraction. The density of nanofluids was increased with increasing nanoparticle volume fractions and decreased with increasing temperature. Lastly, efforts were made to provide a precise correlation to estimate the thermal conductivity, as well as other thermophysical properties at various temperatures and volume fractions of nanoparticles. The comparison between the results and the correlation results showed a good agreement. [ABSTRACT FROM AUTHOR]

Abstract Although there have been reported cases of rapid improvement in the research and development of materials used for the betterment of firefighting tunics in developed countries, however, in developing countries, especially in Nigeria, the dearth of such research and development has led to the loss of lives and properties on numerous occasions due to the use of substandard firefighting tunics when combating fire. Hence, it is necessary to carry out a performance assessment on the firefighting tunic available in Nigeria. The safety of the firefighters is important as it is only then that they can fully carry out their duties and tasks. Of all the products that make up a complete assemble of the firefighters' Personal Protective Equipment (PPE), it is their personal protective tunic that was employed for this research. The city of Ota in Nigeria was used as a case study due to the high concentration of industries and teeming population which makes it a target for pipeline explosions amongst others. Having a single fire station in the city, a sample of the firefighters' personal protective tunic was obtained and specified experiments were carried out to determine its thermophysical and elemental properties with a goal to understand its quality and standard. The research seeks to provide useful information to stakeholders in the firefighting industry on the standard of protective tunics used in fire stations. [ABSTRACT FROM AUTHOR]

Since technology progresses, the need to optimize the thermal system’s heat transfer efficiency is continuously confronted by researchers. A primary constraint in the production of heat transfer fluids needed for ultra-high performance was its intrinsic poor heat transfer properties. MXene, a novel 2D nanoparticle possessing fascinating properties has emerged recently as a potential heat dissipative solute in nanofluids. In this research, 2D MXenes (Ti3C2) are synthesized via chemical etching and blended with a binary solution containing Diethylene Glycol (DEG) and ionic liquid (IL) to formulate stable nanofluids at concentrations of 0.1, 0.2, 0.3 and 0.4 wt%. Furthermore, the effect of different temperatures on the studied liquid’s thermophysical characteristics such as thermal conductivity, density, viscosity, specific heat capacity, thermal stability and the rheological property was experimentally conducted. A computational analysis was performed to evaluate the impact of ionic liquid-based 2D MXene nanofluid (Ti3C2/DEG+IL) in hybrid photovoltaic/thermal (PV/T) systems. A 3D numerical model is developed to evaluate the thermal efficiency, electrical efficiency, heat transfer coefficient, pumping power and temperature distribution. The simulations proved that the studied working fluid in the PV/T system results in an enhancement of thermal efficiency, electrical efficiency and heat transfer coefficient by 78.5%, 18.7% and 6%, respectively.

• Novel protic deep eutectic mixtures synthesized and thermophysical properties determined. • Ultrasound-assisted oxidative extractive desulfurization of tire pyrolysis oil accomplished. • Synergetic effect between ultrasound and DES on the process elucidated. • The physicochemical parameters and calorific value of resulting TPO was determined. One-pot ultrasound-assisted selective oxidative extractive desulfurization (UA-SOEDS) of tire pyrolysis oil (TPO) was carried out with sustainable protic deep eutectic solvent (pDES) synthesized with quaternary ammonium salts as HBA and organic acids as HBD. The Tetrabutyl ammonium chloride and malic acid-based pDES with moderate viscosity resulted in a maximum Sulphur removal of (92.6 % (w/v)). A central composite design-based optimization of essential variables (US time (12 min), US temperature (333.15 K), US power (1.2 kW) and pDES/TPO ratio (22.5 % v/v)) was carried out resulting in an effective sulfur removal rate of (93.6% w/w). The pDES post extraction was recovered with the addition of isooctane and reused for consecutive cycles of UA-SOEDS process, loosing its characteristic oxidative extraction property after 3rd cycle (68.53%). The chromatographic analysis confirmed the presence of long-chain hydrocarbons in the oxidized TPO which confirms its property as a good fuel. The physicochemical properties and the calorific value of the resulting base oil were determined making it a suitable candidate as an alternative green fuel meeting the international standards of soluble Sulphur. [ABSTRACT FROM AUTHOR]

Due to the improved thermophysical characteristics of ionic liquids (ILs), such as their strong ionic conductivity, negligible vapor pressure, and thermal stability at high temperatures, they are being looked at viable contender for future heat transfer fluids. Additionally, the dispersing nanoparticles can further improve the thermophysical characteristics and thermal performance of ionic liquids, which is one of the emerging research interests to increase the heat transfer rates of the thermal devices. The latest investigations about the utilization of ionic liquid nanofluids as a heat transfer fluid is summarized in this work. These summaries are broken down into three types: (a) the thermophysical parameters including thermal conductivity, viscosity, density, and specific heat of ionic liquids (base fluids), (b) the thermophysical properties like thermal conductivity, viscosity, density, and viscosity of ionic liquids based nanofluids (IL nanofluids), and (iii) utilization of IL nanofluids as a heat transfer fluid in the thermal devices. The techniques for measuring the thermophysical characteristics and the synthesis of IL nanofluids are also covered. The suggestions for potential future research directions for IL nanofluids are summarized., (© 2023 Wiley-VCH GmbH.)

An economical and environmentally friendly approach has been introduced to synthesize highly stable graphene nanoplatelets (GNPs) dispersions with different solvents e.g. water, ethylene glycol, methanol, ethanol, and 1-hexanol. The strategy involved with the introduction of hydroxyl groups through mild oxidation of GNPs which was then grafted with citric acid and xylitol that polymerized together, improving the solubility of GNPs. The functionalization of GNPs was proved by Fourier transform infrared (FTIR), Raman spectroscopy and high resolution-transmission electron microscope (HRTEM). Further study was carried out by using xylitol and citric acid (XC)-treated GNPs as an additive in base fluid to check their thermophysical properties. Great stability for water-, methanol-, ethanol-, 1-hexanol- and ethylene glycol-based XC-treated GNPs dispersions at 0.01 wt% was achieved, representing stable weight concentrations of 89%, 75%, 72%, 64% and 82% after 15 days, respectively. In addition, the XC-treated GNPs show remarkable enhancement in the thermal conductivity up to 34% at 60 °C. Furthermore, water-based XC-treated GNPs dispersions with different concentrations show Newtonian behaviour. [ABSTRACT FROM AUTHOR]

The quality determination of biofuels requires identifying the chemical and physical parameters. The key physical parameters are rheological, thermal and electrical properties. In our study, we investigated samples of diesel blends with rapeseed methyl esters content in the range from 3 to 100%. In these, we measured basic thermophysical properties, including thermal conductivity and thermal diffusivity, using two different transient methods - the hot-wire method and the dynamic plane source. Every thermophysical parameter was measured 100 times using both methods for all samples. Dynamic viscosity was measured during the heating process under the temperature range 20-80°C. A digital rotational viscometer (Brookfield DV 2T) was used for dynamic viscosity detection. Electrical conductivity was measured using digital conductivity meter (Model 1152) in a temperature range from -5 to 30°C. The highest values of thermal parameters were reached in the diesel sample with the highest biofuel content. The dynamic viscosity of samples increased with higher concentration of bio-component rapeseed methyl esters. The electrical conductivity of blends also increased with rapeseed methyl esters content. [ABSTRACT FROM AUTHOR]

• Measured density (ρ), viscosity (η) and speed of sound (u) of 1-Propanol (1) + AAc (MAc or EAc or PAc or BAc) (2) • Evaluated V m E , Δ η , u E and k s E from the measured ρ , η and u data. • The V m E values were interpreted by Graph theoretical approach and PFP. • The Δ η values were interpreted by Bloomfield and Dewan model and Graph theoretical approach. • FT-IR investigations and DFT studies well supported the experimental results and qualitative interpretation. The molecular interactions between 1-propanol (1P) (1) and alkyl acetates (AAc) (C 1 -C 4) (2) were examined by understanding of thermophysical properties of given binary liquid mixtures. Density (ρ), viscosity (η) and speed of sound (u) were measured for 1P, AAc and their binary mixture at T = 298.15–318.15 K with interval of 5 K at 0.1 MPa. Experimental data of ρ , η and u were used to evaluate V m E (excess molar volume), u E (excess ultrasonic speed), Δ η (deviation in viscosity), k s E (excess molar isentropic compressibility), G ∗ E (excess Gibbs free energy of activation of viscous flow), V f E (excess free volume), L f E (excess intermolecular free length) and V a E (excess available volume) and correlated with R.K. (Redlich-Kister polynomial) equation. V m E data was also examined in term of Graph theoretical approach (GTA) and Prigogine-Flory-Patterson (PFP) theory. Δ η were analyzed by Bloomfield and Dewan model (BFD) and also examined in terms of Graph theoretical approach (GTA). The u data was examined by different correlations like Van Dael, Nomoto, JFLT (Jacobson's free length theory), Impedance dependence and CFT (Schaaff's collision factor theory). FT-IR spectroscopic studies provide important information for understanding the intermolecular interactions between 1P (1) and AAc (2) components in the binary mixture which is also recognized by GTA. Further, DFT studies indicated the strength of molecular interactions and supported the graph theory in predicting probable associative molecular species in the liquid mixtures. [ABSTRACT FROM AUTHOR]

The thermophysical properties of 1A2P (1-amino-2-propanol) (1) with AAc (methyl acetate (MAc) or ethyl acetate (EAc) or propyl acetate (PAc) or butyl acetate (BAc)) (2) were examined for understanding the molecular interactions between given binary liquid mixtures. Viscosity (η) was measured for 1A2P, AAc (alkyl acetate) and their binary mixture at five different temperatures (T = 298.15 to 318.15 K) and at 0.1 MPa pressure. From η data, the deviation in viscosity, Δ η , and excess Gibbs free energy of activation, G ∗ E , were calculated. The Δ η values were more positive for the 1A2P (1) + MAc (2) binary mixture at equimolar composition which indicate that there is strong intermolecular interaction between 1A2P and MAc molecules. Further, Δ η values were also analyzed by Graph theoretical approach (GTA) and predicted that C O-----H-O interactions are stronger than O H----O-C interactions between 1A2P and AAc molecules in the liquid mixture which is also recognized by FTIR spectroscopic studies. Density functional theory (DFT) studies were employed to investigate the strength of molecular interactions. [ABSTRACT FROM AUTHOR]

The physical characteristics of NixZr100-x proportions based on stretching and heating processes were investigated using molecular dynamics (MD) simulation. The physical characteristics included axial stretching, slip vector of dislocation nucleation, radial distribution function, Poisson’s ratio, and internal energy of thermophysical properties of the NixZr100-x proportions. The second-moment approximation for tight-binding many-body potential was used for NixZr100-x physical characteristics during the MD simulation. Results show that the most Zr atoms of NixZr100-x models after axis stretching obviously move and accumulate at the outside of the NixZr100-x models due to high-temperature softening behavior and high covalent bond strength. The Poisson’s ratios of the Ni20Zr80, Ni40Zr60, Ni50Zr50 Ni60Zr40, and Ni80Zr20, are 0.401, 0.397, 0.490, 0.437, and 0.385, respectively. The Ni50Zr50 proportion has highest Poisson’s ratio, indicating that the transverse contraction strain to longitudinal extension strain is largest than others proportions. For the thermophysical properties, the atoms of Ni50Zr50 in solids are orientation order. [ABSTRACT FROM AUTHOR]

The morphologic and thermophysical characteristics of part of the extensive lava flow fields southwest of Arsia Mons (22.5–27.5°S, 120–130°W) have been examined using a combination of orbital VNIR and TIR datasets. THEMIS images provide context for the regional geology and record diurnal temperature variability that is diverse and unusual for flow surfaces in such close proximity. CTX images were used to distinguish dominant flow types and assess local age relationships between individual lava flows. CTX and HiRISE images provide detailed information on flow surface textures and document aeolian effects as they reveal fine-grained deposits in many low-lying areas of the flow surfaces as well as small patches of transverse aeolian ridges. Although this region is generally dust-covered and has a lower overall thermal inertia, the THEMIS data indicate subtle spectral variations within the population of lava flows studied. These variations could be due to compositional differences among the flows or related to mixing of flow and aeolian materials. Specific results regarding flow morphology include: a) Two main lava flow types (bright, rugged and dark, smooth as observed in CTX images) dominate the southwest Arsia Mons/NE Daedalia Planum region; b) the bright, rugged flows have knobby, ridged, and/or platy surface textures, commonly have medial channel/levee systems, and may have broad distal lobes; c) the dark, smooth flows extend from distributary systems that consist of combinations of lava channels, lava tubes, and/or sinuous ridges and plateaus; and d) steep-sided, terraced margins, digitate breakout lobes, and smooth-surfaced plateaus along lava channel/tube systems are interpreted as signatures of flow inflation within the dark, smooth flow type. These flows exhibit smoother upper surfaces, are thinner, and have more numerous, smaller lobes, which, along with their the channel-/tube-fed nature, indicate a lower viscosity lava than for the bright, rugged flows. Flow patterns and local interfingering and overlapping relationships are delineated in CTX images and allow reconstruction of the complex flow field surfaces. Darker channel-/tube-fed flows are generally younger than adjacent thicker, bright, rugged flows; however, the diversity and complexity of temporal relationships observed, along with the thermophysical variability, suggests that lava sources with different eruptive styles and magnitudes and/or lavas that experienced different local emplacement conditions were active contemporaneously. [ABSTRACT FROM AUTHOR]

Prediction of temperature-dependent thermophysical properties (thermal conductivity, density, specific heat, and thermal diffusivity) is an important component of process design for food manufacturing. Current models for prediction of thermophysical properties of foods are based on the composition, specifically, fat, carbohydrate, protein, fiber, water, and ash contents, all of which change with temperature. The objectives of this investigation were to reevaluate and improve the prediction expressions for thermophysical properties. Previously published data were analyzed over the temperature range from 10 to 150 °C. These data were analyzed to create a series of relationships between the thermophysical properties and temperature for each food component, as well as to identify the dependence of the thermophysical properties on more specific structural properties of the fats, carbohydrates, and proteins. Results from this investigation revealed that the relationships between the thermophysical properties of the major constituents of foods and temperature can be statistically described by linear expressions, in contrast to the current polynomial models. Links between variability in thermophysical properties and structural properties were observed. Relationships for several thermophysical properties based on more specific constituents have been identified. Distinctions between simple sugars (fructose, glucose, and lactose) and complex carbohydrates (starch, pectin, and cellulose) have been proposed. The relationships between the thermophysical properties and proteins revealed a potential correlation with the molecular weight of the protein. The significance of relating variability in constituent thermophysical properties with structural properties--such as molecular mass--could significantly improve composition-based prediction models and, consequently, the effectiveness of process design. [ABSTRACT FROM AUTHOR]

The aim of this experimental study is to measure and analyze the thermophysical properties (density, thermal conductivity, viscosity, and specific heat) and optical properties (transmittance, extinction coefficient) of SWCNTs nanofluids. Different concentrations of 0.1, 0.25, and 0.5 vol.% were investigated. SWCNTs-based nanofluids exhibit significant enhancement compared to water at low volume concentration. The favorable stability, thermophysical, and optical properties of SWCNTs nanofluids are promising for solar thermal applications. They can be utilized as working fluids for DASCs and volumetric solar collectors. [ABSTRACT FROM AUTHOR]

The application of 3D printing techniques is a recently developing area used within foundry technology. Digital production of sand molds and cores eliminates the need for hard tooling, drastically reduces lead times and offers design freedoms not possible in the traditional pattern making. Even though mold and core making technologies are refined from both scientific and practical points of view, casting defects may still occur in the final products. Thus, molding material related casting research is required to generate state-of-the-art methods and understandings to avoid the formation of casting defects. In this paper, a pioneering method is presented which is suitable to determine novel thermophysical and heat transfer properties of various types of molding materials. These properties are strongly connected to the cooling capacity and the gas evolution features of the cores used in casting production. The method is based on temperature measurements inside spherical shaped core sand specimens and evaluated by a special application of Fourier thermal analysis. Temperature measurements were performed in test samples produced by two different 3D core printing systems. The registered temperature data were processed by Fourier thermal analysis to calculate the thermal properties and the decomposition characteristics of the 3D printed cores. The experiments were executed under different heating conditions analogous to aluminium and cast iron production. [ABSTRACT FROM AUTHOR]

Present paper focused on the study of the role of thermophysical properties of nanofluid in changing convective heat transfer and hydrodynamic performances in the conduit flow. The investigation was conducted in a 2-D pipe flow model assigned with specific boundaries while a set of constitutive equations based on finite volume approach were established to solve the model. A fully developed boundary profile for velocity and turbulent parameters was adopted at the inlet which serves as the new approach for investigation of nanofluid to obtain more accurate and faster convergence results. TiO 2 nanoparticle dispersed in water was used in the present study. The plots of the wall parameters showed that the fully developed benchmark was attained at axial distance, x < 1D in comparison to the conventional approach of using constant inlet boundary profiles which require x > 5D. Plots of thermophysical property profiles showed extreme variation from the near wall to the turbulent core regions. It was found that, at mean velocity ratio of unity between the base fluid and nanofluid, the heat transfer augmentation manifested at low velocity and particle concentration. The results highlighted negative heat transfer enhancement above 3% v particle concentration, indicating the degradation of heat transfer performance with increasing particle loading. [ABSTRACT FROM AUTHOR]