Influence Of Temperature Variation Research Articles

Short term creep properties of WPC at different temperatures—An experimental and numerical investigation at different stress levels

AbstractUsing a two‐step molding process, wood plastic composite (WPC) were prepared under temperatures ranging from 160 to 180°C. Uniaxial compression tests of WPC were conducted at temperatures of −20°C, 0°C, 20°C, and 40°C, determining stress levels of 30%, 45%, and 60% based on the test results. Subsequently, 24‐hour compression creep tests were performed for WPC under 12 different conditions. The Findley power law model was employed to fit the experimental results, indicating that creep deformation increased with both stress level and environmental temperature. Notably, specimens at 0°C failed after sustaining a load for 13.6 hours at 60% stress, while those at 20°C failed after only 0.72 hours under the same conditions. Overall, the Findley model effectively predicted the creep behavior of WPC under all temperature conditions and stress levels.Highlights The influence of temperature variation on the strength of WPC. Short term creep of WPC under different stress levels. Creep of WPC at different temperatures. Prediction of creep performance under different operating conditions.

A new method for investigating the impact of temperature on in-situ reservoir properties using high-temperature AFM

Accurately evaluating the influence of temperature variations is crucial for geothermal engineering. Existing conventional testing methods are limited in providing detailed characterizations of reservoir micro properties at high temperatures. This study employed variable-temperature AFM testing techniques to examine sandstone and limestone under in-situ temperatures (25-200°C). The study analyzed the mechanisms behind the temperature effects on rock properties and established theoretical models for porosity and permeability variations with elevated temperatures based on these mechanisms. The research revealed that sandstone and limestone exhibit similar temperature effects at high temperatures. The pore fractal dimension of sandstone and limestone does not change with temperature change. As the temperature increases, sandstone and limestone experience mean roughness (Ra) and porosity reductions. The impact of high temperature was more pronounced on sandstone compared to limestone, with sandstone showing a decrease of 2.8 % and 0.59 % in mean roughness (Ra) and AFM porosity, respectively, from 25 °C to 200 °C, while limestone exhibited reductions of 1.4 % and 0.085 %, respectively. With increasing temperature, sandstone transformed some pores with equivalent diameters of 1-2.5 μm to pores smaller than 1μm, while limestone did not show significant changes in pore structure. The temperature effects on sandstone and limestone were attributed to mineral expansion. Sandstone contains a higher proportion of minerals with a high coefficient of thermal expansion, such as quartz. In contrast, limestone primarily comprises minerals with lower thermal expansion coefficients, such as calcite, resulting in a more significant temperature impact on sandstone than on limestone. The theoretical models based on the mechanisms for porosity and permeability at high temperatures exhibited good predictive performance for sandstone and are more suitable for reservoirs predominantly composed of minerals with high coefficients of thermal expansion. The variation of porosity and permeability at high temperatures have different impacts on geothermal reservoirs. Temperature effects on porosity and permeability should be considered in geothermal engineering.

Effect of temperature rise on the mechanical behaviour of deep-sea clay surrounding oil and gas pipelines

The mechanical behaviour of deep-sea clay is crucial for oil and gas pipeline safety and is traditionally assessed through in situ penetration testing, which is usually conducted in a low-temperature environment (usually at temperatures lower than 4 °C). However, the temperature of deep-sea clay surrounding high-temperature pipelines can reach approximately 20 °C. To date, the influence of temperature variation on the mechanical properties of deep-sea clay, especially strain-softening behaviour, has been largely overlooked, posing a safety risk to practical engineering. Consequently, this study first establishes a temperature-controlled cyclic penetration testing platform. Then, an enhanced mini-spherical penetrometer is employed to investigate the undrained strength and strain-softening behaviour of undisturbed deep-sea clay samples at 4 °C, 10 °C and 20 °C. In particular, an improved framework is proposed to quantitatively characterize the mechanical behaviour. Finally, a strain-softening law considering temperature variations is established and rigorously validated through in situ tests. The findings underscore several significant observations: (a) deep-sea clay in its intact state exhibits a heightened sensitivity to temperature variations compared to that in its remoulded state; (b) temperature variations influence the strain-softening parameters of deep-sea clay, resulting in distinct behaviours; and (c) the proposed strain-softening law considering temperature variations is verified to be more logical.

Effects of Temperature and Layer Thickness on the Static and Dynamic Behaviors of Biocomposite Materials with Interleaved Viscoelastic Layers

This study investigated the influence of temperature variations on the mechanical and dynamic behaviors of biobased composites incorporating a passive control layer. These composites, which include an external layer made up of Flax/polylactic acid (PLA) and an internal layer of rubber, were manufactured using 3D printing technique. To better understand their mechanical characteristics, bending tests were carried out on samples of Flax/PLA with and without a rubber coating at temperatures ranging from [Formula: see text]C to [Formula: see text]C. To evaluate the bending response of the materials under several temperatures settings, three-point bending tests were also conducted on the materials with different viscoelastic layer thicknesses. Additionally, resonance vibration studies were carried out at various temperatures to explore dynamic characteristics like frequencies and damping factors. The analysis of the data revealed the consequences of incorporating a functional rubber layer under diverse circumstances. The results demonstrated that increasing temperatures negatively impacts the mechanical and dynamic characteristics degradation of the composite with the viscoelastic layer. The main objective of this work is that under various thermal settings, passive control layers in biocomposites can display modified mechanical and dynamic behaviors. This understanding of how these biobased composites perform in different environments offers significant context for their possible applications.

Effect of temperature modulation on the performance of top contact bottom gate organic thin film transistor

This research article investigates the influence of temperature variations on the performance parameters of Top Contact Bottom Gate (TCBG) Organic Thin Film Transistors (OTFTs). Employing the Arrhenius equation and Schottky emission model, the study explores temperature-dependent charge carrier mobility and injection mechanisms. Analyzing a wide range of parameters, the research unveils a complex interplay between temperature and OTFT behavior. The linear and saturation mobilities exhibit a decline due to enhanced carrier-phonon interactions and lattice vibrations. Transconductance and ION/IOFF ratio display a concomitant decrease at higher temperatures, indicative of the heightened susceptibility of OTFT performance to temperature fluctuations. The depreciation in subthreshold slope and threshold voltage with rising temperatures underscores the influence of temperature on trap states. The research emphasizes the importance of considering temperature’s impact during OTFT design for diverse applications, enhancing the reliability and functionality of organic electronic devices.

Harnessing solar power with aesthetic innovation: An in‐depth study on spherical and hemispherical photovoltaic configurations

AbstractIn pursuing advancing solar energy systems, this research uniquely occupies a position at the intersection of photovoltaic (PV) efficiency, innovative design and aesthetic integration into urban landscapes. This study explores the potential of thin solar cells applied to spherical and hemispherical surfaces and the influence of temperature variations throughout the day. By conducting a comprehensive analysis of voltage–current diagrams, the study deciphers the intricate interconnections of spherical geometries and their response to external thermal impacts, elucidating their subsequent effects on energy conversion efficiency. Moreover, it delved into the dynamics of connecting multiple spherical modules, unveiling their potential to form artistic and utilitarian constructs such as solar trees and architectural embellishments. The findings indicate that while spherical configurations provide superior aesthetics and a power generation profile comparable to solar tracking systems, hemispherical configurations offer a 32% increase in efficiency compared with the spherical configuration and a notable reduction in land footprint. This research underscores the importance of striking a balance between aesthetic appeal, efficiency and land utilization, providing valuable insights for the future of PV technology integration into urban and agricultural landscapes.

A Study on the Importance of Temperature in Baking

The art and science of baking have been integral to culinary traditions across cultures for centuries. Among the myriad factors influencing the outcome of baked goods, temperature plays a pivotal role in determining the texture, flavor, and overall quality of the final product. This study delves into the significance of temperature control during various stages of the baking process and its profound impact on the characteristics of baked goods. The research encompasses an extensive review of existing literature on baking science, temperature-related chemical reactions, and the role of temperature in ingredient transformations. Experimental investigations are conducted using a range of baked goods, including bread, cakes, and pastries, with meticulous temperature monitoring throughout the entire baking process. The study also explores the influence of temperature variations on the Maillard reaction, fermentation, and other critical processes that contribute to the sensory attributes of baked items. The findings of this research have practical implications for both home bakers and professional pastry chefs, providing insights into optimal temperature parameters for different recipes. Additionally, the study contributes to a deeper understanding of the underlying mechanisms that govern the baking process, offering a foundation for further research and innovation in the field of culinary science. Ultimately, this study underscores the vital role that temperature precision plays in achieving desired outcomes in baking, emphasizing the need for a nuanced approach to temperature management to enhance the quality and consistency of baked goods. As a result, this research contributes valuable knowledge to the culinary community, fostering a more informed and deliberate approach to the temperature aspect of the baking craft.

Wolbachia effects on thermal preference of natural Drosophila melanogaster are influenced by host genetic background, Wolbachia type, and bacterial titer.

Temperature plays a fundamental role in the fitness of all organisms. In particular, it strongly affects metabolism and reproduction in ectotherms that have limited physiological capabilities to regulate their body temperature. The influence of temperature variation on the physiology and behaviour of ectotherms is well studied but we still know little about the influence of symbiotic interactions on thermal preference (Tp ) of the host. A growing number of studies focusing on the Wolbachia-Drosophila host-symbiont system found that Wolbachia can influence Tp in Drosophila laboratory strains. Here, we investigated the effect of Wolbachia on Tp in wild-type D. melanogaster flies recently collected from nature. Consistent with previous data, we found reduced Tp compared to an uninfected control in one of two fly strains infected with the wMelCS Wolbachia type. Additionally, we, for the first time, found that Wolbachia titer variation influences the thermal preference of the host fly. These data indicate that the interaction of Wolbachia and Drosophila resulting in behavioural variation is strongly influenced by the genetic background of the host and symbiont. More studies are needed to better understand the evolutionary significance of Tp variation influenced by Wolbachia in natural Drosophila populations.

Investigation on micro region deformation of residual indents during temperature recovery

Observation of residual indent is widely adopted to evaluate the mechanical properties of material in temperature indentation test. However, the potential influence of the difference between the testing and observing temperatures on the material is always neglected. In this study, crystal plasticity finite element model of copper was constructed, and the processes of high-temperature indentation test and specimen temperature reduction to the observed temperature after the test were simulated. The simulations showed that the error of test hardness can reach up to 4.92% as the residual indent area decreases with temperature decreasing from 800 °C to 20 °C. The stress values of the indentation influence zone were also reduced considerably, in which the maximum stress at 20 °C was 59% of that at 800 °C. The distribution of stresses at surface and subsurface both changed substantially, while the depth of the influence zone increased by 31%. The mechanical properties of material were also found to affect the micro region deformation of residual indents during temperature recovery. Therefore, the influence of temperature variation between the testing and observing processes on residual indent should be seriously considered.

The north-south divide? Macroalgal functional trait diversity and redundancy varies with intertidal aspect.

Marine macroalgae ('seaweeds') are critical to coastal ecosystem structure and function, but also vulnerable to the many environmental changes associated with anthropogenic climate change (ACC). The local habitat conditions underpinning observed and predicted ACC-driven changes in intertidal macroalgal communities are complex and probably site-specific and operate in addition to more commonly reported regional factors such as sea surface temperatures. We examined how the composition and functional trait expression of macroalgal communities in SW England varied with aspect (i.e. north-south orientation) at four sites with opposing Equator- (EF) and Pole-facing (PF) surfaces. Previous work at these sites had established that average annual (low tide) temperatures vary by 1.6 °C and that EF-surfaces experience six-fold more frequent extremes (i.e. >30 °C). PF macroalgal communities were consistently more taxon rich; 11 taxa were unique to PF habitats, with only one restricted to EF. Likewise, functional richness and dispersion were greater on PF-surfaces (dominated by algae with traits linked to rapid resource capture and utilization, but low desiccation tolerance), although differences in both taxon and functional richness were probably driven by the fact that less diverse EF-surfaces were dominated by desiccation-tolerant fucoids. Although we cannot disentangle the influence of temperature variation on algal ecophysiology from the indirect effects of aspect on species interactions (niche pre-emption, competition, grazing, etc.), our study system provides an excellent model for understanding how environmental variation at local scales affects community composition and functioning. By virtue of enhanced taxonomic diversity, PF-aspects supported higher functional diversity and, consequently, greater effective functional redundancy. These differences may imbue PF-aspects with resilience against environmental perturbation, but if predicted increases in global temperatures are realized, some PF-sites may shift to a depauperate, desiccation-tolerant seaweed community with a concomitant loss of functional diversity and redundancy.

Experimental study on pure-shear cyclic deformation of dielectric elastomer at different temperatures

A series of pure-shear cyclic tests were performed on VHB™4910 dielectric elastomer at various temperatures, and the investigations were focused on the influence of temperature variations on the cyclic deformation of the elastomer and the influences of loading level and loading rate on the temperature-dependent cyclic deformation. The results demonstrate that the temperature-dependent deformation of VHB™4910 dielectric elastomer primarily manifests its viscoelasticity, while the hyper-elastic part shows comparatively weaker temperature-dependence. At different temperatures, the elastomer exhibits a cyclic softening during the strain-controlled cyclic loading. Both the peak stress and residual strain reduce with increasing the temperature and reach a stable state more rapidly at higher temperatures. A more pronounced temperature-dependence is exhibited in the stress response of the elastomer at a high loading rate; while a lower rate-dependence is observed at a high temperature. The ratchetting of the elastomer presented in the stress-controlled tests becomes more prominent as the temperature increases, but the rate-dependence of ratchetting is weaker at higher temperatures. Moreover, the temperature-dependence of ratchetting is more significant at a high-stress level as compared to that at a low-stress level.

The role of short‐term temperature variability and light in shaping the phenology and characteristics of seagrass beds

AbstractSeagrass beds inhabit highly heterogeneous temperature regimes that characterize the marine nearshore. Temperature directly influences seagrasses and also provides indirect information on other ecologically relevant environmental variables. Multiple temperature processes operate on seasonal and sub‐seasonal timescales (i.e., hours to months) and include variation from seasonal air–sea heat fluxes, advective heat transport from upwelling and tidal circulation, and daily heating and cooling of shallow waters. Despite this, seagrass–temperature studies typically only examine a single isolated temperature process, often seasonal heating/cooling or marine heatwaves. Furthermore, elucidation of relationships between different short‐term temperature processes and seagrass metrics could provide insights into biologically relevant temperature metrics for seagrasses. Here, we examine the effects of multiple short‐term temperature processes on Zostera marina beds in Atlantic Canada, by describing the seasonal phenology of bed characteristics, plant morphology, and physiology across different temperature regimes and by identifying relationships between different temperature and seagrass metrics. We also include water depth as a proxy for light availability. Four distinct short‐term temperature processes (median temperature, growing degree day [heat accumulation], daily temperature range, and time in the optimal temperature range [5–23°C]) were used to categorize temperature regimes across our study sites as warm and highly variable, or cool and less variable. We found that both temperature regime and light availability were important for leaf area index (LAI) and shoot density, which both decreased with increasing depth yet had the strongest seasonal differences and maximum rates of increase (shoot density) or lowest values and maximum rates of decrease (LAI) in warm and highly variable temperature regimes. These temperature regimes were also associated with seasonal patterns in number of leaves, reduced leaf lengths and number of leaves per shoot, and thinner rhizomes with less carbohydrate storage. Generalized additive models (GAMs) for each seagrass metric using the four temperature processes indicated that while median temperature displayed expected relationships with almost every seagrass metric, inclusion of other temperature processes revealed additional insights not evident from median temperature alone. Our study shows that different sources of short‐term temperature variation influence seagrass properties and that accounting for these will improve our understanding of the temperature–seagrass interaction.

Performance analysis of geometric variations in circular double gate MOSFETs at sub-7nm technology nodes

Circular Double Gate Transistors (CDGTs) is one of the alternative layout-based solutions to mitigate the short-channel effects with superior electrostatic controllability. In this article, TCAD based analysis of the CDGT at the 7 nm node for low-power (LP) applications is carried out and extracted electrical characteristics. The proposed CDGT device offers outstanding performance with ON current of 5.5 × 10−4 Amps, an OFF current of 5.9 × 10−12 Amps, and a corresponding switching ratio of 9.3 × 107 at 300 K. Furthermore, this study examined the performance of CDGT on device geometry by scaling of the gate length from 20 nm to 12 nm and Si thickness variation in the range of 5 nm–8 nm. Additionally, the influence of temperature variation is also studied on CDGT and extracted the temperature compensation point (TCP). Moreover, this simulation illustrates the use of CDGT devices for high switching applications with excellent ON current for lower sub 7 nm technology nodes.

Optimization and comparison of two-stage thermoelectric generators considering the influence of temperature variation on materials for waste heat utilization

Thermoelectricity technology, as a kind of cost-effective and pollution-free power generation solution, is often used for waste heat recovery and utilization. In this paper, the temperature distribution of a Two-stage Thermoelectric Generator (TTEG) under constant temperature conditions has been studied using a one-dimensional heat conduction model. Moreover, by combining the obtained temperature distribution with the three-dimensional size of TTEG, a calculation formula of resistance and voltage was developed based on the calculus method. When the sum of cross-sectional areas of all the PN-type thermoelectric arms respectively in high- and low-temperature layers is constant, the optimal ratio between cross-sectional areas of a single PN-thermoelectric arm respectively in high- and low-temperature layers can be calculated using the proposed formula in this study to achieve the maximum output power. Results also showed the relationship between the heights of PN-type thermoelectric arms and the temperature distributions in high- and low-temperature layers. Using PbTe as the medium temperature thermoelectric material and Bi2Te3 as the low temperature thermoelectric material, a case study was conducted on the PN-type thermoelectrics with the same total height and the same total cross-sectional area. The theoretical calculation results showed that the bigger of maximum output power between the two-stage thermoelectric generator and that of the Segmented Thermoelectric Generator (STEG) is related to the hot and cold end temperature.

Meteorological impact on gravimeter and seismometer readings

Background. The density of atmospheric air varies with temperature. Therefore, variations in the atmospheric layer temperature leads the emergence of local gravity anomalies. The amplitude of such anomalies can exceed ±0.1 mGal. The results obtained by the Arti Geophysical Observatory(Yekaterinburg, Russia) on the non-tidal variations of gravity confirm the influence of temperature variations on gravimeter readings, which may significantly exceed the calculated data. Aim. To assess the impact of weather changes on seismic and gravity fields.Materials and methods. At the RAS Bishkek Geodynamic Test Area (Bishkek, Kyrgyzstan), RAS Institute of Geophysics (Yekaterinburg, Russia) and Zapolye Observatory (Vladimir, Russia), gravity was measured by CG-5 AUTOGRAV gravimeters. At the Shults Cape (Vladivostok, Russia), Arti (Yekaterinburg, Russia) and BFO (Black Forest, Germany [10]) observatories, gravimetric measurements were conducted by La Coste & Romberg tidal gravimeters. Results. Variations in the atmospheric layer temperature were found to lead to the emergence of local gravity anomalies. The amplitude of such anomalies can exceed ±0.1 mGal. The results obtained by the Arti Geophysical Observatory (Yekaterinburg, Russia) on the non-tidal variations of gravity confirm the influence of temperature on gravimeter readings, which may significantly exceed the calculated data. Conclusion. Meteorological processes, such as liquid-water content and the Earth’s atmospheric temperature, affect the readings of gravimeters and seismometers. The atmospheric air density varies with temperature. Along with temperature, gravimeters and seismometers are affected by pressure, humidity and water content of the atmosphere. This is related to atmospheric deformations under the influence of the Moon and the Sun. Meteor streams and their impact on the Earth’s atmosphere have the greatest influence on the readings of gravimeters and seismometers.

The silent impact of underground climate change on civil infrastructure

Urban areas increasingly suffer from subsurface heat islands: an underground climate change responsible for environmental, public health, and transportation issues. Soils, rocks, and construction materials deform under the influence of temperature variations and excessive deformations can affect the performance of civil infrastructure. Here I explore if ground deformations caused by subsurface heat islands might affect civil infrastructure. The Chicago Loop district is used as a case study. A 3-D computer model informed by data collected via a network of temperature sensors is used to characterize the ground temperature variations, deformations, and displacements caused by underground climate change. These deformations and displacements are significant and, on a case-by-case basis, may be incompatible with the operational requirements of civil structures. Therefore, the impact of underground climate change on civil infrastructure should be considered in future urban planning strategies to avoid possible structural damage and malfunction. Overall, this work suggests that underground climate change can represent a silent hazard for civil infrastructure in the Chicago Loop and other urban areas worldwide, but also an opportunity to reutilize or minimize waste heat in the ground.

EFFECT OF IMMERSION TEMPERATURE VARIATION OF SODIUM LAURYL SULFATE 4% AS A DELIPIDATION AGENT ON QUALITY OF COLON TISSUE PREPARATIONS

Background: Adipose or fatty tissue will interfere with the maturation process of the tissue, causing the tissue to become hard, difficult to cut and interfere with the staining of the preparation. Therefore, the adipose tissue needs to be diluted through the delipidation stage. The purpose of this study was to determine the effect of variations in the immersion temperature of colonic tissue using SLS 4% for 6 hours on the quality of the tissue preparations produced and the presence of differences in the quality of the preparations produced.
 Method: This research method uses a quasi-experimental type of research using data obtained from measuring the level of clarity and quality of tissue preparations and then processed statistically using the Paired Sample T-Test . The samples used in this study are the remaining samples in the form of colonic tissue that are no longer used by the Anatomical Pathology Laboratory of Cibabat Hospital. The colonic tissues used is as many 15 units. The parameters used are a 4% SLS clarity rate, and the quality of colonic tissues preparations that are observed microscopically and using ImageJ software.
 Result: The results of the Paired Sample T-Test obtained a value of t = -1.740, df = 14 and gave a p-value much smaller than 0.05. The results of the study showed that there was an influence of temperature variations on the quality of colonic tissue preparations and there were differences in the quality of the colonic tissue preparations produced.
 Conclusion: Colonic tissues that are immersed using a 4% SLS at 60°C provide a more optimal quality preparation compared to colonic tissue at 4% room temperature SLS immersion and tissues that do not go through delipidation.The research suggestion is to conduct further research to obtain optimal time, temperature and concentration in SLS as a delipidation agent so that good quality preparations are obtained but do not eliminate fat completely.

Determination of diffusion coefficient and convective heat transfer coefficient for non-isothermal desorption-diffusion of gas from coal particles

Experiments investigating gas adsorption/desorption-diffusion in coal particles typically involve putting coal particles into a sample cell in a water bath to ensure a constant-temperature environment. Numerical simulations of such experiments have also been performed under isothermal condition. However, the coal particle temperature is not constant, and the influence of temperature variation on the diffusion coefficient back-calculation is often neglected. In this study, CO2 desorption-diffusion experiments are conducted with coal particles first, using the abovementioned water bath technique, and the coal particle temperature is monitored. Then, a coupled thermal-gas model for CO2 adsorption/desorption-diffusion in coal particle is proposed, in which the interaction between gas adsorption/desorption and coal temperature variation is considered. Finally, numerical simulations of the CO2 desorption-diffusion experiments are described, and the applied thermal boundary conditions are validated. The impacts of temperature variation on the desorbed-diffused gas amount and the diffusion coefficient back-calculation are also evaluated. The experimental results show that the coal particle temperature first decreases and then increases. Thus, setting an isothermal boundary condition for the particle surface will not lead to an accurate simulation of the temperature variation, which will ultimately also affect the accuracy of the diffusion coefficient back-calculation. Instead, adopting a convective heat boundary condition for the particle surface can better reproduce the evolution of desorbed-diffused gas and coal temperature changes, thereby improving the accuracy of the diffusion coefficient back-calculation. The results also indicate that the magnitude of coal diffusion coefficient and the size of coal particle both have significant effects on the temperature variation and the subsequent desorption-diffusion of adsorbed gas.

A hybrid CapSA-WHO method used for performance enhancement of tandem perovskite solar cell

This manuscript proposes a hybrid method for determining the effects of contact-electrode and light-power in tandem perovskite solar-cell (PSC) efficiency. The proposed system combines the Capuchin-Search-Algorithm (CapSA) and the Wild-Horse-Optimizer (WHO), together known as CapSA-WHO method. The proposed work creates the following major contributions: (i) investigating the composition of the tandem Perovskite Solar-Cell (SC) layer; (ii) investigating the effectiveness of PSC depending on Formamidinium and tin; (iii) modelling proficient hybrid solar cells; and (iv) analyzes the performance of the proposed SC. The CapSA-WHO technique is used to examine the effect of absorbent layer materials and optimize the devices. This work also investigated the impacts of various materials, such as hole and transport layers, as well as metal back contact, absorber layer flaws, light radiation power, and so on. Moreover, the influence of temperature variation on absorber layer defect density on solar cell is examined. The proposed CapSA-WHO hybrid method is executed in MATLAB or Simulink site and its performance is compared to existing methods. The system gives an optimal solution with minimal computing time by employing the CapSA-WHO technique. Furthermore, the proposed method discovered minimum fault density to attain maximum device efficiency.

Influence of pH and temperature in the performance of Zn phosphate conversion coatings

The influence of variations in temperature (from 50 °C to 70 °C) and pH (2.4 and 2.9) in the Zn phosphate conversion treatment of a high-strength steel was assessed in this study. The effect of the temperature changes depends on the pH of the bath. The results evidenced an enhanced corrosion resistance with the increased temperature for baths at pH 2.4, whereas no relevant differences were concluded for baths at pH 2.9. This latter pH condition provided a better surface coverage, even with lower coating masses, than the former value. The microstructural analysis showed the development of films composed of smaller crystals for the treatments at pH 2.9. Impedance spectroscopy was established as a powerful tool with great potential for characterising phosphate layers. The accuracy of this methodology greatly depends on the equivalent circuit used for the simulation. A model based on the transmission line allows the reliable estimation of the percentage of exposed area (coating efficiency), the identification of changes in the film conductivity, and the qualitative analysis of its structure.