Effect Of Temperature Variation Research Articles

Modeling temperature-dependent transport properties in dissipative particle dynamics: A top-down coarse-graining toward realistic dynamics at the mesoscale.

Dissipative particle dynamics (DPD) is a widespread computational tool to simulate the behavior of soft matter and liquids in and out of equilibrium. Although there are many applications in which the effect of temperature is relevant, most of the DPD studies have been carried out at a fixed system temperature. Therefore, this work investigates how to incorporate the effect of system temperature variation within the DPD model to capture realistic temperature-dependent system properties. In particular, this work focuses on the relationship between temperature and transport properties, and therefore, an extended DPD model for transport properties prediction is employed. Transport properties, unlike the equilibrium properties, are often overlooked despite their significant influence on the flow dynamics of non-isothermal mesoscopic systems. Moreover, before simulating the response of the system induced by a temperature change, it is important to first estimate transport properties at a certain temperature. Thus here, the same fluid is simulated across different temperature conditions using isothermal DPD with the aim to identify a temperature-dependent parametrization methodology, capable of ensuring the correctness of both equilibrium and dynamical properties. Liquid water is used as a model system for these analyses. This work proposes a temperature-dependent form of the extended DPD model where both conservative and non-conservative interaction parameters incorporate the variation of the temperature. The predictions provided by our simulations are in excellent agreement with experimental data.

Production of activated carbon from spent coffee grounds (SCG) for removal of hexavalent chromium from synthetic wastewater solutions

In this research, spent coffee grounds (SCG) are converted into a highly valuable porous adsorbent which removes chromium (VI) from wastewater with high efficiency. A set of nine Spent Coffee Ground Activated Carbon (SCG-AC) adsorbent samples were synthesized, by varying key parameters including pyrolysis temperature (400, 600 °C), pyrolysis duration (1 and 2 h), and the impregnation ratio of the activating agent, KOH (ranging from 0:1 to 2:1). Characterizations of these adsorbent samples were conducted by advanced analytical tools including SEM, EDX, XRD, FTIR, TGA, and BET. Furthermore, we carried out adsorption studies, exploring the effects of temperature and dosage variations. Additionally, point zero charge experiments and desorption studies were carried out to further understand the adsorption process. The outcomes of our investigation demonstrate the successful synthesis of these spent coffee ground-derived adsorbents, with a yield of up to 34%. Notably, these adsorbents exhibited high efficiency in extracting chromium (VI) from water, with removal efficiencies ranging from 75% to 100%. The adsorption isotherms revealed the Langmuir model to be the most fitting descriptor of the adsorption behavior. Moreover, a thermodynamics study revealed the process to be endothermic in nature which furthers our understanding of the underlying mechanisms. Importantly, our cost assessment shows the economic advantage of the synthesized adsorbent over commercial counterparts such as zeolite, making it a competitive choice for real-world applications. In summation, the study not only introduces an innovative and sustainable utilization of spent coffee grounds but also delivers an in-depth exploration of the synthesized adsorbent's ability in chromium (VI) removal. Our holistic approach, encompassing thorough experimentation, characterization, and economic evaluation, solidifies the significance of this research in tackling environmental concerns and propelling advancements in wastewater treatment methodologies.

Effect of temperature variations on the fabrication of SLS-Na2CO3-ES-P2O5-CaF2-Al2O3 based bioglass-ceramics

Effect of temperature variations on the fabrication of SLS-Na2CO3-ES-P2O5-CaF2-Al2O3 based bioglass-ceramics

Transcription factor roles in the local adaptation to temperature in the Andean Spiny Toad Rhinella spinulosa

Environmental temperature strongly influences the adaptation dynamics of amphibians, whose limited regulation capabilities render them susceptible to thermal oscillations. A central element of the adaptive strategies is the transcription factors (TFs), which act as master regulators that orchestrate stress responses, enabling species to navigate the fluctuations of their environment skillfully. Our study delves into the intricate relationship between TF expression and thermal adaptation mechanisms in the Rhinella spinulosa populations. We sought to elucidate the dynamic modulations of TF expression in prometamorphic and metamorphic tadpoles that inhabit two thermally contrasting environments (Catarpe and El Tatio Geyser, Chile) and which were exposed to two thermal treatments (25 °C vs. 20 °C). Our findings unravel an intriguing dichotomy in response strategies between these populations. First, results evidence the expression of 1374 transcription factors. Regarding the temperature shift, the Catarpe tadpoles show a multifaceted approach by up-regulating crucial TFs, including fosB, atf7, and the androgen receptor. These dynamic regulatory responses likely underpin the population’s ability to navigate thermal fluctuations effectively. In stark contrast, the El Tatio tadpoles exhibit a more targeted response, primarily up-regulating foxc1. This differential expression suggests a distinct focus on specific TFs to mitigate the effects of temperature variations. Our study contributes to understanding the molecular mechanisms governing thermal adaptation responses and highlights the resilience and adaptability of amphibians in the face of ever-changing environmental conditions.

Direct effect of artificial warming on communities is stronger than its indirect effect through body mass reduction

Theory predicts that morphological and bioenergetic constraints due to temperature‐induced body size reduction can modulate the direct effects of warming on biotic interactions, with consequent effects on trophic cascades and biomass distribution. However, these theoretical predictions have rarely been tested empirically. Our aim was to distinguish the indirect effects of warming‐induced body size reductions from the direct effects of warming on community structure. We conducted a mesocosm experiment manipulating factorially 1) body size reduction in the medaka fish Oryzias latipes using two populations raised for several generations under contrasted climate conditions and 2) warming (+4°C), to test their independent and interactive effects on the structure of prey and primary resource communities, the predator–prey biomass ratio and the biomass size spectra. We further dissected the effects of seasonal temperature variation from the effects of constant artificial warming. We found that the indirect effects of warming (i.e. fish body size reduction) on composition and structure of communities as well as their biomass size spectra were of marginal amplitude compared to the direct effects of seasonal temperature variation and constant warming. There were no changes in community composition in response to fish body size reduction or constant warming. However, the density of macroinvertebrates and zooplankton were maximal at intermediate seasonal water temperatures and lower in constantly‐heated mesocosms. Contrastingly, phytoplankton was not strongly affected by seasonal temperature or warming, but rather responded to grazing effects of zooplankton. Finally, we found a reduction in predator–prey biomass ratio under warming and at the warmest seasonal temperature, inducing a steeper slope of the biomass size spectra under increasing seasonal (but not constant) temperature. We conclude that the direct effects of climate change on freshwater communities are stronger than its indirect effects mediated by body mass reduction.

Gut Microbial Adaptation to Varied Altitudes and Temperatures in Tibetan Plateau Yaks.

The yak (Bos grunniens) exhibits exceptional regional adaptability, enabling it to thrive in the distinctive ecological niches of the Qinghai-Tibet Plateau. Its survival relies on the intricate balance of its intestinal microbiome, essential for adapting to harsh environmental conditions. Despite the documented significance of bacteria and fungi in maintaining intestinal homeostasis and supporting immune functions, there is still a substantial gap in understanding how the composition and functionality of yak gut microbiota vary along altitude-temperature gradients. This study aims to fill this gap by employing 16S rRNA and ITS amplicon sequencing techniques to analyze and compare the intestinal microbiome of yaks residing at different elevations and exposed to varying temperatures. The findings demonstrate subtle variations in the diversity of intestinal bacteria and fungi, accompanied by significant changes in taxonomic composition across various altitudes and temperature gradients. Notably, Firmicutes, Actinobacteriota, and Bacteroidota emerged as the dominant phyla across all groups, with Actinobacteriota exhibiting the highest proportion (35.77%) in the LZF group. Functional prediction analysis revealed significant associations between the LZF group and metabolic pathways related to amino acid metabolism and biosynthesis. This suggests a potential role for actinomycetes in enhancing nutrient absorption and metabolism in yaks. Furthermore, our findings suggest that the microbiota of yaks may enhance energy metabolism and catabolism by modulating the Firmicutes-to-Bacteroidota ratio, potentially mitigating the effects of temperature variations. Variations in gut bacterial and fungal communities among three distinct groups were analyzed using metagenomic techniques. Our findings indicate that microbial genera exhibiting significant increases in yaks at lower altitudes are largely beneficial. To sum up, our research investigated the changes in gut bacterial and fungal populations of yaks residing across diverse altitude and temperature ranges. Moreover, these results enhance comprehension of gut microbial makeup and variability, offering perspectives on the environmental resilience of dry lot feeding yaks from a microbial angle.

Effect of Extrusion Temperature Variations for Manufacturing 3D Printer Filament Based on Used Bottle Waste on Impact Strength

Effect of Extrusion Temperature Variations for Manufacturing 3D Printer Filament Based on Used Bottle Waste on Impact Strength

Parameters estimation and sensitivity analysis of lithium-ion battery model uncertainty based on osprey optimization algorithm

To advance the field of lithium-ion battery (LIB) research, this paper unveils an accurate modelling of LIB that primarily relies on the equivalent circuit model, backed by the Osprey Optimization Algorithm (OOA). In the modelling stage, both single and double resistance-capacitance models are evaluated to depict the charge dynamics, incorporating the effects of fading, load, and temperature variations. The OOA approach is utilized to minimize integral squared errors between the actual measured and model-predicted battery voltages under constraints imposed by the model design variables. This approach is applied to a commercial 2.6 Ahr Panasonic LIB, with the performance of the OOA-based model being benchmarked against models developed by means of other optimization algorithms for further validation. Moreover, the robustness of the OOA method is assessed under battery uncertainty conditions or model parameter variation. A sensitivity analysis is performed on the battery model by employing a proposed approach that evaluates the impact of varying each parameter of the battery model by ±5 %, in a sequence that ascends and descends from 0 to 5 %. The single resistance-capacitance model is selected for in-depth validations. Notably, the OOA approach excels in estimating parameters for LIB modeling under both normal and abnormal operating conditions.

Comprehensive evaluation of the influence of PEM water electrolyzers structure on mass transfer performance based on entropy weight method

The proton exchange membrane water electrolyzer (PEMWE) has broad prospects in hydrogen production due to its green and efficient advantages. This paper comprehensively analyzes the performance and water-gas transport characteristics of PEMWE with different cell structures, in which polarization curves, flow velocity distribution, oxygen concentration, temperature, liquid water saturation, and pressure are investigated. Simultaneously, the study explores the effects of variations in inlet velocity, inlet temperature, porosity, and thickness of the anode porous transport layer (APTL) on the four flow fields. Finally, the technique for order preference by similarity to ideal solution (TOPSIS) based on entropy weight method is employed for a comprehensive evaluation of the flow fields. The results indicate that, compared to parallel flow field (PFF), sinusoidal wave flow field (SWFF), intercepted flow field (ICFF), and single-serpentine flow field (SSFF) exhibit stronger exhaust capabilities, with temperature uniformity increasing by 83.65 %, 59.24 %, and 70.15 %, respectively. However, the longer flow channel of SSFF results in a high pressure drop and lower liquid water saturation. An increase in inlet velocity leads to a decrease in temperature, causing an increase in voltage, as higher temperatures reduce activation and ohmic overpotentials. Additionally, an increase in the porosity and thickness of APTL deteriorates the polarization performance of PEMWE. The research results of this study can provide valuable assistance for the future design of PEMWE.

Impact of long-term temperature shifts on activated sludge microbiome dynamics and micropollutant removal

Micropollutants removal efficiency strongly vary across different aerobic wastewater treatment plants, resulting in their frequent detection in surface and ground waters. Seasonal temperature variation is a major factor influencing plant performance, but it is still unclear how prolonged periods of temperature change impact microbiome and micropollutant biotransformation. This work investigates the effect of long-term temperature variation on the microbial dynamics in an activated sludge system, and the impact on micropollutant biotransformation. Sequencing batch reactors were used as model system and 4–40 °C temperature range was studied. 16S rRNA amplicon sequencing showed that temperature drives microbial structure (gDNA) and activity (RNA), rather than time, and this was stronger below 15 °C and above 25 °C. The microbial community was richest and more diverse at 20 °C, while rarer and more specific taxa became predominant over time, at more extreme temperatures. This suggested that less abundant taxa might be responsible for maintaining the biotransformation capability in the activated sludge at extreme temperatures. Micropollutant biotransformation rates mostly deviated from the classic Arrhenius model below 15 °C and above 25 °C, indicating that prolonged exposure to temperature changes leads to temperature-induced taxonomic shifts, resulting in the emerging of different sets of biotransformation pathways over different temperature ranges.

Impact of seasonal global land surface temperature (LST) change on gross primary production (GPP) in the early 21st century

Understanding the impact of global land surface temperature (LST) changes on gross primary production (GPP) is crucial for addressing global sustainability challenges effectively. This article explores the effects of winter and summer temperature variations on GPP from 2001 to 2020 on a global scale, employing a range of modeling techniques to investigate the complex relationship between temperature changes and GPP. The study employs various modeling approaches, including linear regression models, artificial neural networks, Random Forest (RF) models, and the XGBoost algorithm to examine both linear and non-linear relationships between global temperature changes and GPP. The results reveal that the RF and XGBoost models effectively capture the non-linear relationship between LST and GPP during both summer and winter, demonstrating a high level of statistical significance (P < 0.01) and achieving R2 values of 0.598. Furthermore, the study applies a Sen+MK trend analysis model to identify six distinct trend patterns in LST and GPP during both summer and winter seasons. In summer, the area exhibiting a non-significant increasing trend (NSI) for GPP covers 65,066,274.77 km2, whereas in winter, a strong significant decreasing trend (SSD) for GPP spans 64,537,108.31 km2. Notably, GPP patterns closely mirror those of LST, suggesting that rising high-temperature conditions during summer lead to reduced GPP, while increased low temperatures during winter promote GPP growth. Robust correlations between LST and GPP are observed under various trend conditions in both summer and winter, displaying strong statistical significance (P < 0.01), with SSD achieving a maximum R2 of 0.594. These findings contribute significantly to our comprehensive understanding of the dynamic relationship between LST and GPP and offer valuable insights for addressing the sustainable development of global climate change challenges.

Design and analysis of mode-matched decoupled mass MEMS gyroscope with improved thermal stability

This paper presents an efficient design approach for microelectromechanical systems (MEMS) gyroscope considering the design constraint of MEMSCAP’s Silicon-on-Insulator Multi-User MEMS Processes (SOIMUMPs). A design for a decoupled mass MEMS resonant gyroscope with tuning electrodes is presented to minimize cross-axis coupling and optimize the gyroscope’s performance. The device features a size of 1.8 ×2.772 mm2 . A decoupled mass MEMS gyroscope has been designed using a novel mechanical beam configuration that optimizes the structural design to reduce unwanted interactions between drive and sense axes motions. Mode order has been achieved by obtaining the first two modes as drive and sense modes at 9946.3 Hz and 10 202.7 Hz, respectively. Parallel plate electrostatic tuning electrodes have been added to adjust and match the drive and sense modes at the resonant frequencies of 9946 Hz. This mode matching is crucial for optimizing gyroscope performance, accuracy, and sensitivity. The effects of temperature variation on the performance of the designed decoupled mass MEMS gyroscope have been investigated, particularly in terms of its mode-matched operation achieved using tuning electrodes. Finite element method (FEM) simulations were conducted, demonstrating that thermal stability was achieved, and mode-matched operation was maintained within the temperature range of −40 °C to 80 °C. The gyroscope exhibits enhanced performance compared to existing MEMS gyroscopes under mode-matched conditions, featuring a lower temperature coefficient of frequency (TCF) at 0.0415 Hz °C−1 in the drive mode and 0.0165 Hz °C−1 in the sense mode. FEM analysis for the fabrication process tolerances has been done, where MEMS gyroscope’s resonant frequencies, output capacitance, output displacement, and sense mode quality factor have shown negligible changes to fabrication process tolerances. Transient analysis was conducted using CoventorWare MEMS+ 3D schematic, which was integrated with MATLAB Simulink to measure the MEMS gyroscope’s output response, which corresponded with the varying input angular velocity signal.

Environmental drivers of tree species richness in the southernmost portion of the Paranaense forests

BackgroundThe Rio de la Plata grassland region is dominated by temperate grasslands, with the scarce natural forests, influenced floristically by adjacent biogeographical provinces. Uruguay represents the southern limit for many tree species of the Paranaense Province, several of which inhabit the hillside forests. With many species shifting poleward due to climate change, we do not yet know how current environmental factors, particularly climatic ones, are linked to the tree diversity of this flora nowadays. The aim of this study is to understand the geographic pattern of tree richness in the hillside forests of Uruguay, evaluating the water–energy and the environmental heterogeneity hypotheses. The distribution of the hillside forest trees was obtained by compiling and updating the herbaria database and distribution maps of woody plants of Uruguay. The presence/absence of each species, and then the species richness, were georeferenced over a grid that covers Uruguay with 302 cells (660 km2). Over the same grid were compiled environmental variables associated with climate and environmental heterogeneity. The relationship between richness and environmental variables was studied by applying general linear models (GLM). As a strong autocorrelation was detected, a residuals auto-covariate term was incorporated into the GLM, to take into account the species richness spatial structure.ResultsThe tree flora of the hillside forest was composed mainly by Paranaense species that show a latitudinal gradient, with two high richness cores, in the east and northeast of Uruguay. The final model including the environmental variables and the spatial term explained 84% of the variability of tree richness. Species richness showed a positive relationship with precipitation, forest cover, potential evapotranspiration and productivity, while a negative effect of temperature variation was found. The spatial component was the primary predictor, accounting for a 30% of spatial pattern of tree richness.ConclusionsThis study accounts for a large proportion of the environmental and spatial variations of the tree richness pattern of the Paranense flora in its southernmost portion. It brings support to both water–energy and environmental heterogeneity hypotheses, emphasizing the role of climate and its variation and the habitat availability on the hillside forest diversity.

Effects of Cl-ion and temperature variations on steel corrosion in supercritical CO2 saturated aqueous environments

This study explored the influence of Cl-ion and temperature variations on the corrosion behavior of pipeline steel in supercritical CO2 (s-CO2) saturated aqueous environments. The steel exposed to the s-CO2 saturated salt solution at 50°C shows a higher corrosion rate (CR) of 5.02 mm/year compared to that exposed to deionized (DI) water, which has a corrosion rate of 1.47 mm/year. This trend is more pronounced at higher temperatures. This performance enhancement is attributed to the formation of a dense and protective FeCO3 film, facilitated by the Cl-ion presence, with a more pronounced effect observed at higher temperatures. The corrosion mechanism, commencing with the impact of Cl- ions on interactions between CO2 and the dissolved HCO3- ions with iron at the steel surface, is comprehensively elucidated via density functional theory (DFT) in s-CO2 systems at varied temperatures. The findings from this study offer valuable insights into mitigating corrosion-related challenges in s-CO2 system.

Effects of packaging methods and temperature variations on the quality and microbial diversity of grouper (Epinephelus Lanceolatus) during cold storage

Microbial growth and its metabolism are the primary reasons for fish spoilage. In this study, the effects of temperature fluctuations and modified atmosphere packaging (MAP) on the quality and microbial diversity of grouper (Epinephelus lanceolatus) during cold storage were investigated. Fish fillets were packed in air packaging (AP), vacuum packaging (VP), MAP1 (40% CO2/55% N2/5% O2), and MAP2 (60% CO2/35% N2/5% O2), and stored at T1 (4 °C) and T2 (4–8 °C temperature fluctuations), respectively. Total viable counts (TVC), psychrophilic bacteria count, Pseudomonas count, and H2S-producing bacteria count all increased during cold storage. Pseudomonas, Serratia, and Carnobacterium were the dominant genera in AP, VP, and MAP2 at T1 storage, with relative abundances of 82.7%, 54.5%, and 57.3%, respectively. Temperature fluctuations accelerated the spoilage process of the grouper, and increased the relative abundance of Serratia in the samples, but had less effect on the composition of these spoilage bacterial members. The microbial community was more affected by the different gas atmospheres. MAP inhibited the growth of Pseudomonas and increased the relative abundance of Carnobacterium and Psychrobacter in the samples. Low temperature and MAP effectively suppressed the rise of pH, total volatile basic nitrogen (TVB-N), trimethylamine (TMA), thiobarbituric acid reactive substances (TBARs), and K values and maintained the water holding capacity (WHC) and sensory quality of the samples. Grouper had the longest shelf life under MAP2-T1 treatment. The MAP2-T1 samples maintained lower levels of TVB-N (151.8 mg/kg), TMA (7.6 mg/kg), TBARs (0.90 mg MDA/kg), and K value (48.5%) and higher levels of WHC (77.6%) on the 18th day, with a lower degree of spoilage compared to other samples.

Effects of variation in air conditioner temperature on lung functions of air conditioner users

Background: As a result of increasing environmental temperature, use of air conditioner(AC) has become very popular specially in the urban areas mostly during hot months of the year. Regular exposure to cold, dry air of AC can cause various alterations in lung functions of AC users which can lead to many lung diseases in future. These alterations in lung functions can be influenced by AC temperature fixation. Objective: This study aimed to observe the effect of variation of AC temperature on lung function in apparently healthy adult subjects living in Dhaka city, Bangladesh. Method:This cross sectional study was conducted on 48 apparently healthy adult male and female who were exposed to cold air discharged by air conditioner for at least 6 hours per day for minimum 5 days per week for the past 2 to 4 years. They were then divided into two groups based on setting temperature at which AC was regulated. Group A was consisted of 24 subjects (12 male and 12 female) who were exposed to AC temperature constantly regulated in between 18° C to 22°C. Group B consisted of 24 subjects (12 male and 12 female) who were exposed to AC temperature constantly regulated in between 23°C to 25°C. Forced vital capacity(FVC),forced expiratory volume in first second (FEV1), and ratio of FEV1/FVC were estimated in all subjects to assess lung functions using Minato Autospiro AS-507.Percentage of predicted value of all parameter was used in data analysis. Statistical analysis was done by unpaired Student’s ‘t’ test. Results: In this study mean percentage (%) of predicted value of FVC FEV1, and FEV1/FVC were significantly lower in group A in comparison to group B. Conclusion: Regulation of AC at a lower temperature can lead to more reduction of lung function in AC users. J Bangladesh Soc Physiol 2022;17(2): 72-77

Confluence Effect of Debris-Filled Damage and Temperature Variations on Guided-Wave Ultrasonic Testing (GWUT)

Continuous monitoring of structural health is essential for the timely detection of damage and avoidance of structural failure. Guided-wave ultrasonic testing (GWUT) assesses structural damages by correlating its sensitive features with the damage parameter of interest. However, few or no studies have been performed on the detection and influence of debris-filled damage on GWUT under environmental conditions. This paper used the pitch–catch technique of GWUT, signal cross-correlation, statistical root mean square (RMS) and root mean square deviation (RMSD) to study the combined influence of varying debris-filled damage percentages and temperatures on damage detection. Through experimental result analysis, a predictive model with an R2 of about 78% and RMSE values of about 7.5×10−5 was established. When validated, the model proved effective, with a comparable relative error of less than 10%.

Climate adaptation investments: Short-term shocks and long-term effects of temperature variation on air conditioning adoption

Air conditioning (AC) has gradually become the main way for households to adapt to climate change. Using a climate econometric model with two-way fixed effects, we systematically examine the short-term shocks and long-term effects of temperature variation on AC ownership in urban and rural households in the Yangtze River Delta region of China. When considering short-term shocks of temperature variation, our results indicate that cooling demand is the main driver of growth in AC ownership while heating demand and intra-seasonal temperature variance are not. In terms of the long-term effect, we find mean summer temperature has a positive lagged effect, with the cumulative effect being larger for rural households. The analysis of heterogeneity shows that while the greater elasticity of air conditioning ownership to temperature variation for rural residents indicates a faster diffusion of air conditioning during 2001–2020, the larger income elasticity (greater than 1) suggests that air conditioning is still a luxury item for them. Our findings not only provide empirical evidence for studying the pattern of climate adaptation investments in response to temperature variation, but also offer policy guidelines for households to better adapt to climate change.

Investigation of the unsteady thermal storage performance of metal foam dual-phase change unit thermal storage tanks in solar thermal utilization systems

The adoption of metal foam thermal energy storage (TES) tanks in solar thermal utilization systems is crucial for enhancing energy supply stability. In this study, to investigate the transient thermal storage performance of TES tanks, a model of a solar thermal utilization system integrated with solar collectors and TES tanks was established. The model was validated through a literature review and experiments. The effects of initial temperature variation of solar collectors and the addition of metal foam on the transient heat transfer characteristics and thermal efficiency of TES tanks were analyzed. The results indicate that the porous structure of metal foam restricts natural convection, thereby improving temperature drift caused by displacement due to phase change material density variation. Maintaining the same initial temperature of solar collectors, filling metal foam can avoid the occurrence of melting dead zones at the bottom of pure paraffin phase change units, leading to an enhancement in the thermal efficiency of TES tanks and a reduction of 48.44% in phase change completion time. Additionally, a low initial temperature of the solar thermal collection system contributes to improving the thermal efficiency of metal foam composite TES tanks.

Effect of Varied Cure Temperature on the Cure Behavior, Mechanical Properties and Heat Build-Up of Solid Tire Tread Compound Containing Different Particles Sizes of Ground Tire Rubber

This work investigates the effect of variation in vulcanization temperature on the cure behavior, tensile properties, tear strength, hardness, Akron abrasion loss and heat build-up of vulcanized tire tread compound in which the total rubber was replaced with 10% and 20% ground tire rubber (GTR) of 40, 60 and 80 mesh sizes. The first step was the characterization of the GTR using optical microscopy and a thermogravimetric analyzer. The first step of mixing each rubber compound was carried out using an internal mixer (Brabender) at 60°C and 40 rev/min rotor speed and the second step was done on a two-roll mill. The mooney viscosity of each rubber compound was investigated. the cure behavior of the rubber compounds was studied at 140°C, 150°C, and 160°C respectively. Results show that the introduction of GTR reduced vulcanization time, while increased cure temperature resulted in a lower vulcanization time. No significant difference was observed in the vulcanization time at a particular temperature of the rubber sample with different particle sizes and varied amounts of GTR. The introduction of ground tire rubber in the rubber vulcanizate however resulted in decreased tensile strength, tear strength and elongation, and increased hardness, abrasion resistance, modulus and heat build-up. An increase in the vulcanization temperature from 140°C to 150°C and 160°C did not impart a significant reduction in the tensile strength of the vulcanizates containing GTR. Vulcanization at higher temperatures resulted in reduced hardness, and modulus, slightly increased abrasion loss and increased elongation of the vulcanizates containing GTR. The heat build-up increased as the cure temperature increased. Generally, the control sample with no content of ground tire rubber exhibited the best properties. If GTR is to be introduced in rubber matrix at an amount up to 20%, the results suggest that 60 mesh size particles will impart better properties. The optimal vulcanization temperature recommended based on the findings from the work is 150°C.