Effect Of Temperature Research Articles

Thermal conductivity of MX80 powders-granules mixture and its prediction for high-level radioactive waste repository

Bentonite granules and their mixtures with powders are considered to be a preferred sealing material for filling gaps between buffer layer and surrounding rock in high-level radioactive waste (HLW) repository. Due to continuous release of decay heat from nuclides, thermal conductivity of bentonite granules must be assessed. In this study, the effects of water content, dry density, temperature on the thermal conductivity in the directions parallel (λpar) and perpendicular (λperp) to the bedding plane of MX80 powders-granules mixture (PGM) were investigated by thermal probe technique. Test results showed that the thermal conductivity of powdered bentonite (PB) was higher than that of PGM and λpar was higher than λperp. With increasing water content, the difference rate (δPSD) in thermal conductivity between PB and PGM increased, and anisotropy coefficient α (a ratio of λpar to λperp) decreased, while the effects of dry density and temperature on δPSD and α were not obvious. The factor importance was analyzed, and results showed that the effects of water content, dry density, temperature, and particle size distribution decreased successively. A modified geometric mean (MGM) model for predicting thermal conductivity of PGM with temperature is proposed and it predicted thermal conductivity of MX80 PGM well.

Effect of extrusion temperature on microstructure and mechanical properties of ZTM631 magnesium alloy

Magnesium alloys are widely used in the fields of aviation, electronics, and automotive manufacturing due to their advantages of lightweight and high specific strength. Studying high-performance and low-cost deformed magnesium alloys to adapt to more application scenarios has important value. In the present work, the effect of extrusion temperature on the microstructure and mechanical properties of Mg-6Zn-3Sn-0.9Mn (ZTM631) alloy was investigated. Besides, the ultra-high cycle fatigue (VHCF) performance and fatigue failure mechanism of ZTM631 alloy was explored. Results show that extrusion temperature significantly affect the microstructure of ZTM631 alloys. Firstly, alloys extruded at 300℃ possess a relatively fine grain size, because the lower extrusion temperature prevent the grain growth. Secondly, phases precipitate at 300°C and 350°C with a large size (more than 1µm) are mainly α-Mn phase. while for the alloys extruded at 400°C, both α-Mn and Mg2Sn phases with the size larger than 1µm can be found in the matrix. Thirdly, alloys extruded at 400℃ exhibit the best mechanical properties, due to the combination of the grain refinement and precipitation strengthening. Fourthly, during the VHCF failure process, the crack preferentially generates at the densely distributed α-Mn phases for the alloy extruded at 300°C and 350°C, while the crack initiate near the Mg2Sn particles for the alloy extruded at 400°C. Also, undynamic recrystallized (un-DRXed) grains with severe deformation exist in the alloys extruded at 300℃ and 350℃, thus accelerating the crack initiation. This fundamental investigation provides theoretical information for developing high-performance Mg-Zn-Sn alloys with high strength and expanded their application fields.

Effect of temperature on the reaction of pristine and Au-doped SnO2 pyramid clusters with H2: A transition state theory study

Effect of temperature on the reaction of pristine and Au-doped SnO2 pyramid clusters with H2: A transition state theory study

The Effect of Temperature and Film Thickness on Domain Wall Energy Density, Coercivity Force, and Magnetostriction of Galfenol Films

The Effect of Temperature and Film Thickness on Domain Wall Energy Density, Coercivity Force, and Magnetostriction of Galfenol Films

The potential of biochar derived from banana peel/Fe3O4/ZIF-67@K2CO3 as magnetic nanocatalyst for biodiesel production from waste cooking oils

Using biomass-based catalysts in biodiesel production can make the process more economical and environmentally friendly. In this study, a new magnetic nanocatalyst was developed using banana peel biochar, ZIF-67, Fe3O4, and K2CO3, and then utilized in a catalytic transesterification process to convert waste cooking oils (WCO) into biodiesel. The level of free fatty acids of the treated WCO (WCOT) was reduced to generate a biodiesel with more suitable characteristics. The physicochemical aspects of the magnetic nanocatalyst were characterized by Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) and map techniques. In the transesterification process, the effect of temperature, methanol-to-oil ratio, process time, and nanocatalyst weight on the potential of nanocatalyst to produce biodiesel from WCO and WCOT was explored. The highest yield of biodiesel from WCO (96.82%) and WCOT (99.18%) was attained at 65 °C, nanocatalyst weight of 3 wt %, methanol-to-oil ratio of 19:1, a processing time of 3 h, and a mixing rate of 600 rpm. Based on thermodynamic studies, the biodiesel production process was endothermic and non-spontaneous. The regeneration of the nanocatalyst was studied using various solvents and n-hexane had a good ability to recover the catalyst (90% up to 5 stages). The results of the 1H NMR test revealed that the desired nanocatalyst had a high potential to generate biodiesel from WCO and WCOT. The properties of produced biodiesel met ASTM D6751 and EN 14214 standards.

Effects of temperature and pressure on the limiting current density of PEM electrolysis cells based on a theoretical prediction model and experiments

Operation at high current density of polymer electrolyte membrane electrolysis cell (PEMEC) can reduce its electrode area and capital expense. The high current density operation is limited by the limiting current density (LCD), where electrolysis voltage abruptly increases. Effects of operating temperature and pressure on the LCD were evaluated in a lab-scale PEMEC within a range from 70 to 90 °C and from 0.1 to 0.3 MPa. Also, a theoretical model was developed to predict the LCD, and to clarify what determines LCD and how the operating conditions influence the LCD. The theoretical analysis suggests that when current density is close to the LCD, water mass transport at anode reaches a limitation, which indicates that water saturation reaches almost zero at anodic catalyst layer. The analysis also finds that lower operating temperature and higher operating pressure can reduce oxygen gas saturation and raise the water saturation in porous transport layer at anode, and finally enlarge the LCD.

Temperature Effect on Buckling Properties of Thin-Walled Composite Profile Subjected to Axial Compression

Temperature Effect on Buckling Properties of Thin-Walled Composite Profile Subjected to Axial Compression

Recent research and developments of degradation assessment and its diagnosis methods for solar PV plant: a review

The world is moving forward to a transition in the form of increasing the contribution of renewable energy sources in the energy sector, and among these, solar photovoltaic-based power generation is catching pace. Several factors are responsible for the lowering of outputs due to different degradation causes such as hotspots, corrosion, humidity, ultraviolet (UV) irradiation, temperature effects, dust, aging, weathering, yellowing, snail trails, discoloration, junction box failure, delamination, cracks, and faults from the solar photovoltaic (PV) plants. This paper presents a comprehensive review of the various form of degradation and their implications on solar PV power plant performance. The review has been carried out considering the different degradation causes and their identification methods in solar PV plant. Further, the analysis has been done on the basis of the earlier studies to understand the rates of degradation for various solar PV power plants in various climatic conditions. The PV technologies used in solar power plants are also responsible for the change in the performance of power plants over time; therefore, degradation based on different solar PV cell technologies is also analyzed. The visual inspection tools like thermal imaging with IR cameras help identify areas with abnormal heat patterns, indicating potential issues like cell or interconnect failures, loose electrical connections, or bypass diode malfunctions while EL cameras are used to identify low-level electrical excitation and defects such as cracks, hotspots, and cell-level degradation.

Effect of solution temperature on the microstructure and properties of ceramic coating on the surface of 2024 aluminum alloy

This study investigates the influence of the 2024 aluminum alloy was treated with solution before ceramic treatment on the microstructure and characteristics of ceramic coatings applied to 2024 aluminum alloy substrates. The microhardness, corrosion resistance, and microstructural properties of these ceramic coatings were assessed using a microhardness tester, an electrochemical workstation, and a scanning electron microscope. The findings indicate that pre-treatment involving solution treatment significantly enhances the hardness and corrosion resistance of 2024 aluminum alloy ceramic coatings. Notably, when the solution temperature was maintained at 460 °C, the most rapid decrease in current density was observed during the ceramization process, resulting in the attainment of the lowest final stable current density. This particular condition yielded ceramic coatings with optimal hardness and corrosion resistance, with hardness exhibiting a remarkable increase of 48.9 HV, self-corrosion potential rising by 0.207 V, and polarization resistance surging by 5310.7 Ω. Moreover, the surface of the ceramic coating displayed remarkable smoothness and was devoid of discernible defects such as cracks or looseness. In light of these findings, it can be concluded that the optimum solution temperature for achieving these desirable properties is 460 °C. This conclusion is derived from a comprehensive analysis encompassing both the morphology and corrosion resistance of ceramic coatings.

Preparation of mesoporous biogas residue biochar via a self-template strategy for efficient removal of ciprofloxacin: Effect of pyrolysis temperature

Biochar preparation and application is an anticipated pathway for the resource utilization of biogas residue. In this study, biochars were prepared by the pyrolysis of biogas residue from food waste anaerobic digestion (named as BRBCs) under various pyrolysis temperatures (300, 500, 700, and 900 °C), and the effect of pyrolysis temperatures on the physicochemical characteristics of BRBCs was examined. The adsorption performance toward ciprofloxacin (CIP), a typical antibiotic in waterbodies, was also investigated. The results showed that pyrolysis temperature significantly changed the physicochemical properties of BRBCs. In addition, the minerals in the biogas residue, especially SiO2, were rearranged to form a mesoporous structure in biochar through a self-template strategy (without activator). BRBC prepared at 900 °C exhibited a high specific surface area and pore volume, well-developed mesopore structure, and more carbon structure defects, and exhibited the largest CIP adsorption capacity with 70.29 mg g−1, which was ascribed to the combined interaction of pore diffusion, π–π interactions, hydrogen bonding, complexation, and electrostatic forces. Furthermore, the adsorption of CIP by BRBC900 was well described by two-compartment kinetic and Langmuir isotherm models. BRBC900 showed good adsorption performance toward CIP at pH 7–9. The adsorption of CIP by BRBC is a spontaneous, exothermic, entropy-increasing process. Moreover, BRBC also presented a good recycling potential. Therefore, the preparation of mesoporous biochar based on a self-template strategy not only provides an option for the resource utilization of biogas residue but also offers a new option for the treatment of antibiotic wastewater.

Effects of high temperature and high relative humidity drying on moisture distribution, starch microstructure and cooking characteristics of extruded whole buckwheat noodles

Effects of high temperature and high relative humidity drying on moisture distribution, starch microstructure and cooking characteristics of extruded whole buckwheat noodles

Prediction of Axial Compression Behavior of Confined Concrete Columns Considering the Effect of Cryogenic Temperatures

Prediction of Axial Compression Behavior of Confined Concrete Columns Considering the Effect of Cryogenic Temperatures

Facile fabrication of nickel-cobalt oxide for efficient oxygen evolution reaction from ammonia leaching solution of spent lithium-ion batteries

Ammonia leaching has been gained considerable attention for its ability to selectively extract nickel and cobalt from spent ternary cathode material. Despite its efficacy, the subsequent recovery of ammonia leachate remains challenging. Herein, a short-process and sustainable method for the synthesis of nickel-cobalt oxide via ammonia evaporation of ammonia leachate and heat treatment of the resultant precursor has been proposed. The ammonia evaporation process, conducted at an evaporation temperature of 130 °C with hydrazine hydrate as a reducing agent, facilitated the precipitation of ∼95% Ni and ∼99% Co as a precursor. Subsequently, the effect of precursor roasting temperature on electrode material synthesis was systematically studied. The precursor was roasted at 300 °C to successfully synthesize nickel-cobalt oxide. Physical and electrochemical characterizations revealed that the nickel-cobalt oxide possesses a significant specific surface area of 161.150 m2/g, and exhibits excellent oxygen evolution reaction performance, evidenced by an overpotential of 350.7 mV at 10 mA/cm2 and a Tafel slope of 159.8 mV/dec. Overall, the proposed method not only promotes the recycling and utilization of ammonia reagents and mother liquor, but also introduces an innovative approach for the synthesis of nickel-cobalt oxide as an electrode material.

Analysis of converter transformer pressboard insulation degradation under surge using mathematical morphology

Nowadays, with the significant expansion of industrial growth, the bulk power requirement can only be satisfied through high-voltage direct current HVDC transmission. The converter transformer is the utmost vital part of the HVDC transmission. Pressboard insulation is most commonly used as inter-disc insulation in converter transformers. During working conditions due to elevated temperature and different operational stresses, insulation material gets deteriorated. It may cause a risk to the life of the converter transformer. The effects of elevated temperatures as well as frequency on pressboard insulation of the converter transformer are examined in this study. The condition evaluation and morphological changes in pressboard insulation at elevated temperatures can evaluate with the help of frequency domain spectroscopy (FDS) and atomic force microscopy (AFM) techniques. The impact of elevated temperatures on insulation material can be analyzed based on surface roughness and dielectric parameters. In MATLAB Simulink environment, a dual winding single-phase converter transformers valve side star winding 60 discs model is constructed for impulse test. Based upon arrival time and velocity of traveling wave, insulation degradation location can be identified by using mathematical morphology. The simulation results demonstrate that the suggested method can notably located degradation across disc winding.

Finite element analysis of a generalized rotating FGM vessel subjected to thermo-mechanical loadings: Effect of Poisson ratio and inhomogeneity parameters.

Cylinders and thick walled cylindrical shells are commonly utilized in several industries to transport and store fluids under certain pressure and temperature conditions. In the present paper, a numerical solution is developed in order to investigate displacement, temperature and stress fields in a rotating pressure vessel made of generalized functionally graded material (FGM) subjected to different thermo-mechanical boundary conditions. The aim is to investigate the effect of Poisson ratio, internal pressure and temperature and inhomogeneity parameters on the stress and deformation distributions of the rotating pressure vessel. The material is considered isotropic nonhomogeneous and linearly elastic with its properties varying along the radial direction. Additionally, certain conditions, such as exterior or interior problems where r → ∞ or r → 0, respectively, are impossible to resolve using the variation of attributes as a power-law distribution. An approach to the spatial Young modulus distribution that is more broad has been suggested in the literature which can be applied to such physical challenges. The rotation of the pressure vessel is considered in the analysis, and the temperature distribution is assumed to be non-uniform. Since an analytical solution to the differential equation is not accessible, the conventional Galerkin discretization approach of the Finite Element Method (FEM) is applied, nowadays is considered one of the main numerical tools for solving Boundary Value Problems (BVP). It is addressed how stress, strain, and displacement are affected by the inhomogeneity parameter, rotation speed, pressure, temperature, and Poisson ratio. The examination of the various findings indicates that changes in the temperature profile, rotation, and inhomogeneity parameter on the thermoelastic field have a substantial impact on the stress and strain in the FGM cylinder. The findings indicate that the Poisson ratio and inhomogeneity parameters have a significant impact on the stress and deformation distributions. According to the results, the above-mentioned parameters can be adapted to control the thermoelastic filed in a FGM cylinder. The present research offers significant perspectives on the development and enhancement of rotating FGM pressure vessels intended for high-temperature applications.

A technique for separating the impact of cycle aging and temperature on Li-ion battery capacity

Reduction of battery capacity is a well-known symptom of aging, making it a universally accepted indicator of the state of health. Capacity also significantly depends on temperature, therefore, separating the effect of temperature from that due to aging has utmost important for a proper state of health assessment. However, according to the latest literature, there is a lack of information about how the temperature dependency of capacity changes with battery aging. In this respect, the study presented in this paper is based on an experimental campaign aimed at measuring battery capacity at different temperatures and cycling levels. Starting from the obtained results, an analytical model describing how the variation law of battery capacity with temperature is affected by cycling was proposed and validated. The achieved accuracy is better than 0.6 % for all the considered operating conditions.

Thermal transport in disordered wurtzite ScAlN alloys using machine learning interatomic potentials

Disordered wurtzite ScAlN alloy is an emerging material with a strong piezoelectric coefficient that promotes its application in 5G communication devices. To extend the service lifetime of the device, it is an urgent task to understand the thermal transport properties of this alloy for thermal management. Yet a thorough understanding of the thermal transport in the disordered ScAlN alloy is hindered by the inaccuracy of empirical interatomic potentials adopted for atomistic simulations. Herein, we developed an accurate and efficient neuro-evolution potential and combined it with Allen and Feldman theory and molecular dynamics to investigate thermal transport properties of disordered ScAlN alloys with varying ratios. This potential is shown to have the same computational accuracy as first principles by comparing the phonon spectrum and radial distribution function. Based on the homogeneous non-equilibrium molecular dynamics simulations, the lattice thermal conductivity of the disordered alloys reaches its maximum value (less than 12W/m·K) at room temperature. Further investigation of the temperature effects on the vibrational modes shows that it affects the mode lifetimes for the propagons and the mode heat capacities for the diffusions. In addition, it was found that both mode lifetime and diffusivity decrease with increasing Sc concentration. This work aims to train a universal machine learning interatomic potential of disordered ScAlN alloys, seeking to accelerate the thermal management design of related devices.

Comparative analysis of single-axis solar tracker performance with and without reflector under various weather conditions

This research explores a sun tracking system for solar panels that affects the power output of the panels. To address this, a unidirectional sun tracking system is implemented to ensure the solar panels are perpendicular to the sun, thus optimizing solar radiation. Additionally, reflectors are integrated to capture more sunlight. This research aims to design the system of unidirectional sun tracking to enhance the power output generated by solar panels and compare its performance with stationary (static) solar panels. The results demonstrate that the system of sun tracking improves the power output of solar panels. However, when reflectors are used in conjunction with the sun tracking system, no significant increase in power output is observed. Moreover, solar panels equipped with the unidirectional sun tracking system exhibit a power increase of 52.06 Watts compared to stationary solar panels. This research indicates that employing a unidirectional sun tracking system with the addition of reflectors does not enhance power output but instead reduces it due to the increased temperature effect caused by the sunlight reflection from the added reflectors.

How the fertility of males and females is affected by stress, lifestyle and pharmaceutical agents

Background: Infertility in men is the most discussed issue among couples. It is generally believed that about half of infertility in couples is due to the men side, mainly due to frustrations in the process of spermatogenesis. Currently it has been found that lifestyle modifications are vital to improve infertility and interest in this area has increased. Examples include maturation, mental stress, diet, active work, high temperature of scrotum, hot water, caffeine, and mobile phone use. This review will examine the effects of personal satisfaction (a modifiable lifestyle factor) and mental stress on infertility in male. It will also show the effects of high scrotal temperature and unhealthy views of exercise on infertility in male. Materials and Methods: Forty of the 118 (34%) men patients who underwent IVF agreed to participate in this review. Only patients having IVF for the first time were recalled for re-examination to reduce the adjustments to the sperms sample screening process that would occur in men with some experience of IVF. Of these, 31 completed the retest and eight decided not to proceed after the initial testing period; one patient's cycle was cancelled prior to ovulation. Conclusion: Our study found that IVF patients had significantly lower sperm quality when they collected their eggs, which suggests a link between sperm quality and psychological stress. Whether physical (frozen reserve sperm samples) or psychological (evacuation preparation, targeted morphology, treatment groups) interventions are effective in reducing stress in male IVF patients and controlling stress-related changes in sperm quality is still unknown. Further studies are awaited to light some further developments.

Unraveling the reasons for failure to control Amaranthus albus: insights into herbicide application at different growth stages, temperature effect, and herbicide resistance on a regional scale.

This study investigates factors contributing Amaranthus albus control failure in processing tomato fields in northern Israel. The study region is characterized by a significant climate gradient from east to west, providing the opportunity to investigate the effect of critical elements of the agricultural environment, e.g., temperature. Eight populations were collected from commercial fields in this region. Post-emergence herbicide efficacy of metribuzin, a photosystem II inhibitor, and rimsulfuron, an acetolactate synthase (ALS) inhibitor, was assessed through dose-response analyses at various growth stages. Temperature effects on control efficacy and resistance mechanisms were also explored. Standard metribuzin dose (X) was ineffective on A. albus plants with more than six true-leaves, whereas 2X dose proved effective. Rimsulfuron at 16X dose was ineffective on plants with more than four true-leaves. We report here the first case of target site resistance to ALS inhibitors in A. albus, due to point mutation in the ALS gene (Pro197 to Leu). Furthermore, our findings suggest potential involvement of CYT P450 enzymes in enhanced metabolizing of rimsulfuron. An overall decrease in dry weight was observed in response to both herbicides at 16/22 °C (P < 0.0001). Rimsulfuron was effective against only one population when applied at 28/34 °C. A possible fitness cost associated with target site-resistant biotypes was observed under low temperature conditions, leading to effective control. This regional-scale study highlights the challenges faced by growers, emphasizes the need for adapting management practices to the local climatic conditions and lays the groundwork for implementing location-specific weed management strategies in commercial fields. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.