Increase In Environmental Temperature Research Articles

THE MECHANICAL PROPERTIES AND FAILURE MODE OF SIMULATED LUNAR ROCK BY IN SITU TEMPERATURE REAL-TIME ACTION OF LUNAR-BASED

To achieve in situ condition-preserved coring of the lunar surface and deep lunar rocks and a return mission, it is necessary to explore the mechanical properties and failure modes of simulated lunar rocks that have physical and mechanical properties approximately equivalent to those of mare basalt under simulated lunar temperature environments ([Formula: see text][Formula: see text]C to 200[Formula: see text]C). To this end, real-time uniaxial compression tests were conducted on simulated lunar rocks under corresponding in situ temperature conditions, and the mechanical properties, deformation characteristics, micromorphology, and failure modes were analyzed. Based on the macroscopic analysis, as the environmental temperature decreases, the uniaxial compressive strength, peak strain, and peak strain duration of simulated lunar rocks exhibit a nonlinear increasing trend, with maximum increases of 33.00[Formula: see text], 36.16[Formula: see text], and 49.25[Formula: see text] from those at room temperature, respectively. Based on microscopic analysis, the intergranular fractures run through the entire samples under the environmental temperature. As the environmental temperature increases, intergranular and transgranular fractures coexist, and layered fractures appear at high temperatures. At the same time, some samples exhibit undulating and stepped morphologies caused by shear stress. For the fractal dimension of a simulated lunar rock main fracture surface, the fractal dimension of the actual angle and the corrected angle increase first and then decrease with increasing environmental temperature, and the maximum error of the two is only 1.84[Formula: see text]. The overall fractal dimension ranges from 2.02 to 2.28, and the fractal dimension under real-time high-temperature conditions is higher than that under real-time low-temperature conditions. In addition, the failure mode of the simulated lunar rocks under real-time in situ temperature changes is a combined tensile–shear failure mode with shear failure (primary) and tensile failure (secondary). The above research results are expected to be applied to in situ condition-preserved coring in extreme lunar environments and provide a scientific basis for the design and development of in situ condition-preserved coring robot systems for the extreme environment of deep space.

Effects of squeezed vacuum field on force sensing for a dissipative optomechanical system

We investigate the force sensing of a mechanical membrane in a dissipative cavity optomechanical system (OMS) driven by a squeezed vacuum field accompanying a strong pump laser. Specifically, the red-detuned laser exhibits a more significant improvement for force sensing compared to the blue-detuned laser. The optimal phase angle contributes to achieving much better force sensing. When injecting a squeezed vacuum field with appropriate squeezing parameter and squeezing phase, the standard quantum limit of force measurement can be easily beaten. Furthermore, the adverse effects of the increase in environment temperature and mechanical damping can be suppressed, simultaneously. This scheme provides a theoretical basics for force sensing of mechanical membranes in dissipative OMS and has potential applications in force feedback control, precision measurement, and force sensor design.

Unveiling the potential of Moringa oleifera Lam. gums: An investigation into optimal tapping strategies

To optimize the best tapping technique for enhanced gum production with minimal injury to the trees, suitable Moringa oleifera Lam. trees were selected for experimentation, and the trees were treated with different tapping techniques for moringa gum production. When gum inducer was applied to trees treated with battery and hand-operated drills with ½ inch drill bit diameter and 1.0 in. drilling diameter, the gum yield was about fifteen times higher than when the inducer was not applied. It was about four times higher for trees treated with hand-operated drills and 1.0 in. drilling diameter. When employing the Gum tapping blazer-75 to develop a blaze, the average gum production was 1.29 times higher than when using a chisel. Bore hole developed with 1.0 in. diameter hand drill with inducer application yielded the highest total gum yield, followed by ½ inch diameter hand drill and ½ inch battery operated drill with inducer application, blaze developed with Gum tapping blazer-75, bore hole developed with 1.0 in. diameter hand drill without inducer application, blaze developed with chisel, bore hole developed with ½ inch hand drill without inducer application, and bore hole developed with battery operated drill having ½ inch drill bit without inducer application, respectively. A regular increasing trend in moringa gum yield was observed almost in all the treatments with an increase in environmental temperature, which indicates that moringa gum can be tapped throughout the year but a higher quantity of gum may be collected during April–September. When employing the Gum tapping blazer-75, blaze is produced on the tree trunk with ease and sharp edges. The use of developed blazer made blazing faster compared with blaze making using chisel. Gum production was higher with gum inducer technology than with any other method when it came to tapping moringa gum from Moringa oleifera trees using a hand drill. Data on quality characteristics determined for engineering can be used as references in development of equipments and machineries for processing and value addition of moringa gum while chemical properties for various applications in food, pharmaceutical and cosmetic industries for development of high value products.

The Feasibility Study of In Situ Conversion of Oil Shale Based on Calcium-Oxide-Based Composite Materia Hydration Exothermic Reaction

Oil shale, as a vast potential resource, is considered an important alternative energy source, and its effective development and economic utilization are of significant importance in alleviating the contradiction between energy supply and demand. Presently, the in situ conversion technology for oil shale has gained significant global attention, with numerous extraction methods undergoing active research and development. One of these methods is the in situ conversion of oil shale based on the hydration reaction of calcium-oxide-based composite material (CaO-CM). This approach harnesses the heat produced by the reaction between CaO-CM and water as a heat source for the pyrolysis of oil shale. This paper conducted experiments to assess the feasibility of temperature associated with this method. The feasibility study mainly includes two aspects: First, it is necessary to investigate whether the temperature generated by the hydration reaction of CaO-CM can meet the temperature requirements for the pyrolysis of oil shale. Through pyrolysis experiments of Xinjiang oil shale, the minimum temperature required for oil shale pyrolysis was determined to be 330 °C. High-temperature and high-pressure reaction vessels were employed to explore the temperature generated by the hydration reaction of CaO-CM. The results show that with the increase in environment pressure, environment temperature, and reaction mass, the maximum temperature generated by the hydration reaction of CaO-CM also increases (reach 455.5 °C), meeting the temperature requirements for the pyrolysis of oil shale. Second, the study evaluates whether the hydration reaction of CaO-CM can induce pyrolysis hydrocarbons of the oil shale. Through the pyrolysis experiments of oil shale based on the hydration reaction of CaO-CM, the changes in the content of pyrolysis hydrocarbons (S2) in oil shale before and after pyrolysis are measured. The results show that under 10 MPa pressure, the content of pyrolysis hydrocarbons in the oil shale decreased from 40.96 mg/g to 0.08 mg/g after pyrolysis. This confirms the feasibility of the temperature conditions for the in situ conversion of oil shale based on the hydration reaction of CaO-CM.

Performance of a deep in situ pressure-preserving coring controller in a high-temperature and ultrahigh-pressure test system

The pressure-preserving controller is the key component of deep in situ pressure-preserving coring (IPP-Coring). With increasing drilling depth, the environmental temperature and pressure increase accordingly. However, due to the strength and sealing problems of pressure-preserving controllers, the coring pressure is generally lower than 70 MPa. Establishing a high-temperature and ultrahigh-pressure test system is highly important for improving the strength and sealing performance of pressure-preserving controllers. This paper introduces a high-temperature and ultrahigh-pressure test system for deep IPP-Coring controller performance analysis. The device includes six parts: an auxiliary air source system, a pressurization system, a temperature control system, a hydraulic system, a data acquisition and electrical control system, and an ultrahigh-pressure vessel. The test system can reconstruct a 150 °C and 200 MPa in situ environment and simulate and test the movement state of the corer and the stability of the pressure-preserving action trigger of the pressure-preserving controller in the deep IPP-Coring process. To verify the performance of this test system, saddle-shaped pressure-preserving controllers made of four different materials were subjected to pressure tests under normal-temperature and high-temperature conditions. The results showed that the ultimate pressure-bearing capability of the pressure-preserving controller greatly varied between normal-temperature and high-temperature conditions. The pressure-preserving ability and sealing performance of the pressure-preserving controller decreased significantly at high temperature, and the pressure-preserving controller exhibited significantly different sealing failure characteristics due to material differences. This study is important for progressing the extraction and evaluation of deep reservoir resources.

Population-specific responses to developmental temperature in the arboviral vector Aedes albopictus: Implications for climate change.

The increase of environmental temperature due to current global warming is not only favouring the expansion of the distribution range of many insect species, but it is also changing their phenology. Insect phenology is tightly linked to developmental timing, which is regulated by environmental temperatures. However, the degree to which the effects of developmental temperatures extend across developmental stages and their inter-stage relationships have not been thoroughly quantified in mosquitoes. Here, we used the mosquito Aedes albopictus, which is an aggressive invasive species and an arboviral vector, to study how developmental temperature influences fitness across developmental stages, thermal traits, energy reserves, transcriptome and Wolbachia prevalence in laboratory-reared populations originally collected from either temperate or tropical regions. We show that hatchability, larval and pupal viability and developmental speed are strongly influenced by temperature, and these effects extend to wing length, body mass, longevity and content of water, protein and lipids in adults in a population-specific manner. On the contrary, neither adult thermal preference nor heat resistance significantly change with temperature. Wolbachia density was generally lower in adult mosquitoes reared at 18°C than at other tested temperatures, and transcriptome analysis showed enrichment for functions linked to stress responses (i.e. cuticle proteins and chitin, cytochrome p450 and heat shock proteins) in mosquitoes reared at both 18 and 32°C. Our data showed an overall reduced vector fitness performance when mosquitoes were reared at 32°C, and the absence of isomorphy in the relationship between developmental stages and temperature in the laboratory population deriving from larvae collected in northern Italy. Altogether, these results have important implications for reliable model projections of the invasion potentials of Ae. albopictus and its epidemiological impact.

Tetraploid wheat (Triticum turgidum) lines from the United States as a source of Hessian fly (Mayetiola destructor) resistance

AbstractDeploying resistant wheat cultivars is the most economical and environment‐friendly strategy to manage the devastating effects of the dipteran pest, Hessian fly (Hf; Mayetiola destructor). Currently, 37 Hf resistance genes have been identified to combat the 18 Hf genotypes documented so far. However, the Hf populations adapt rapidly to overcome the newly deployed resistance genes within a few years of release resulting in development of virulent Hf biotypes and breakdown of plant resistance. Identification of new and novel sources of resistance offers breeders additional resources that can be included in the breeding programmes to develop elite Hf‐resistant cultivars. In the current study, we screened 374 wheat (tetraploid and hexaploid) accessions originating from different regions of the United States and identified three tetraploid (Triticum turgidum) pasta wheat lines, one originating from North Dakota (PI 639869) and two from Minnesota (PI 352398 and CItr 15710) exhibiting ≥95% resistance to Hf biotype L at 20°C. Further, the wheat cultivar PI 352398 showed 100% resistance to six additional Hf genotypes including biotypes B, C, D, O, GP and vH13. The lines PI 639869 and CItr 15710 also showed >70% resistance with most biotypes, except against biotype GP with the former and biotype B with the latter. Interestingly, a few plants from these two cultivars exhibited putative tolerance to these biotypes where the plants showed normal growth but harboured white, live larvae and showed cell permeability that was intermediate in levels between Hf‐infested resistant and susceptible wheat. Additionally, since the increase in environmental temperatures to 25–30°C also negatively impacts Hf resistance, the three T. turgidum (PI 639869, PI 352398 and CItr 15710) cultivars were evaluated for Hf resistance at 30°C. None of the wheat cultivars were resistant to Hf biotype L at 30°C indicating a temperature‐dependent breakdown of resistance and are therefore not suitable for geographical regions with higher environmental temperatures. Taken together, these three wheat lines represent additional sources of Hf resistance that can be leveraged by breeders for developing durable elite lines.

Linear modeling analysis of the heat balance of the transmission line in high frequency critical ice melting state

Abstract The icing of transmission lines can cause many problems such as increased line load, unbalanced tension, and galloping, posing a serious threat to the reliable operation of the power system. Therefore, linear modeling analysis of the heat balance under a high-frequency critical ice melting state of transmission lines is studied. The thermal conduction states of melting, heating, twisting, rotating melting, and ice layer detachment of ice melting conductors are analyzed. Based on the heat conduction process of thermal melting of ice on transmission lines, a simplified calculation formula for thermal melting ice time is derived to calculate times for heating, ice layer torsion, and air gap increase. At the same time, based on the law of conservation of energy, thermodynamic boundary conditions for iced conductors were established and corresponding physical models were constructed. Based on this model, we conduct a linear modeling of the heat balance in the melting state in order to provide a more accurate prediction of temperature distribution. The experimental results show that there is a negative correlation between environmental temperature and critical melting current, and the melting time decreases with the increase of environmental temperature.

Experimental study on refrigeration system performance of pure electric refrigerator car based on medium pressure air supply

In view of the low refrigeration efficiency of the refrigeration system of the pure electric logistics car under the high temperature environment, an experimental platform of the refrigeration system based on medium pressure air supply of the pure electric refrigerator car was built with R404A as the refrigerant, the experiment results show that the system refrigerating capacity, COP and EER decrease with the increase of external environment temperature under the same internal environment temperature, the compressor power and exhaust temperature increase with the increase of the external environment temperature. When the external environment temperature is 43 °C, the medium pressure air supply technology is obviously better than the non-air supply technology, the refrigerating capacity increased by 4.1–12.73 %, the compressor power and EER changed little, the COP increased by 1.3–6.38 %, and the exhaust temperature reduced by 3.4 °C-7.11 °C, especially at -3 °C, the system refrigerating capacity decreases by 30.1 %, the compressor power increases by 35.6 %, the COP and EER distribution decreases by 51.24 % and 42.68 %.

Resolving 3D microstructure evolution of ceramifiable composites at elevated temperatures using in-situ X-ray computed tomography

Ceramifiable polymer composites suffers significant microstructure change during the polymer-to-ceramic conversion as the environmental temperature increases. The present study employs in-situ X-ray computed tomography (XCT) to reveal the microstructure evolution of high-silica/boron-phenolic composites modified with B4C and talc (B4C-talc_HSF/BPR) in three dimensions as the composites is heated to 1000 °C. The cracks are classified based on their locations, and the temporal sequence of their formation is identified. The evolution of internal pore distribution is reconstructed and analyzed quantitatively. Furthermore, the 3D deformation fields of composites during in-situ heating were calculated using digital volume correlation. It is found that the equivalent strain along the thickness direction shows a multi-stage behavior corresponding to the thermal degradation and ceramization transformation processes. The findings provide a 3D visualization of crack propagation and deformation during the polymer-to-ceramic conversion process, which can provide a foundation for further developments in material design.

Geography and developmental plasticity shape post-larval thermal tolerance in the golden star tunicate, Botryllus schlosseri

Local adaptation and phenotypic plasticity play key roles in mediating organisms’ ability to respond to spatiotemporal variation in temperature. These two processes often act together to generate latitudinal or elevational clines in acute temperature tolerance. Phenotypic plasticity is also subject to local adaptation, with the expectation that populations inhabiting more variable environments should exhibit greater phenotypic plasticity of thermal tolerance. Here we examine the potential for local adaptation and developmental plasticity of thermal tolerance in the widespread invasive tunicate Botryllus schlosseri. By comparing five populations across a thermal gradient spanning 4.4° of latitude in the northwest Atlantic, we demonstrate that warmer populations south of the Gulf of Maine exhibit significantly increased (∼0.2 °C) post-larval temperature tolerance relative to the colder populations within it. We also show that B. schlosseri post-larvae possess a high degree of developmental plasticity for this trait, shifting their median temperature of survival (LT50) upwards by as much as 0.18 °C per 1 °C increase in environmental temperature. Lastly, we found that populations vary in their degrees of developmental plasticity, with populations that experience more pronounced short-term temperature variability exhibiting greater developmental plasticity, suggesting the local adaptation of developmental plasticity. By comparing the thermal tolerance of populations across space and through time, we demonstrate how geography and developmental plasticity have shaped thermal tolerance in B. schlosseri. These results help inform our understanding of how species are able to adjust their thermal physiology in new environments, including those encountered during invasion and under increasingly novel climate conditions.

The influence of heat stress on the antioxidant protection glutathione link and the content of lipid peroxidation products in chicken liver

Heat stress is one of the main reactions of the body’s response to environmental factors, negatively affecting the welfare of various animal species. An increase in environmental temperature can cause stress, which, in turn, potentially has various negative consequences for animals including disruption of the antioxidant system functioning. Violating the antioxidant-prooxidant balance can lead to an increased free radicals formation in the body, which can damage cells and promote the development of various diseases. The article presents the study results of the artificially simulated heat stress effect on individual indicators of the antioxidant system and lipid peroxidation products in the chickens’ liver. The choice of these animals for this study is due to the fact that the poultry is particularly sensitive to the elevated environmental temperatures and, accordingly, to heat stress. This is caused by the biological peculiarities of birds, in particular, they lack sweat glands, and their body surface is mostly covered with feathers, which, together with the high density of keeping in the industrial poultry farming, often leads to the heat stress. The purpose of this work was to find out the presence or absence of changes in individual indicators of the antioxidant system glutathione link and the lipid peroxidation products content in chickens’ liver. The analysis of indicators such as lipid hydroperoxides (LOOH), TBA-active products, reduced glutathione (GSH), glutathione peroxidase (GSH-Px) and glutathione reductase (GR) will allow us to obtain information about the body’s antioxidant defense system state and the oxidative stress level under heat stress conditions. In this study we used 18 hens of the white Leghorn breed. The research was conducted in the vivarium of the Institute of Animal Biology of the National Academy of Sciences in two stages. During the first stage, chickens were kept at an air temperature of 20°С for 7 days. During the second stage, we created heat stress conditions by increasing the temperature to 35°С 6 hours a day, also for 7 days. It has been found that as the ambient temperature increased, the content of LOOH, GSH, and activity of GSH-Px in the liver of chickens increased (P<0.01), while, on the contrary, the content of TBA-active products and activity of GR decreased (P<0.01). The obtained data prove the heat stress effect on the antioxidant protection glutathione link in chicken liver. Research results can be of practical value for improving the bird keeping conditions in the industrial poultry farming, developing strategies for protection against stress, and improving the conditions to ensure the animals’ welfare and health.

Lamp for light: How temperature and humidity determine light management in Upper Paleolithic decorated cave environments

Analysis of lighting system management in Upper Paleolithic decorated caves is crucial to our understanding of the light sources used to create and observe depictions created deep in the interior halls. We developed a novel method for analyzing the environmental effects of the different light systems used in Upper Paleolithic caves. Our method uses a computer simulation to analyze the interplay between fire intensity, cave hall structure, and internal environmental conditions. We show that the potential for fire use in the deep interior halls is limited due to the dangerous conditions produced by the increase in environmental temperature combined with the cave's natural high humidity. To avoid serious heat-related illnesses such as heat stroke, careful management of the light system would be required. We identified cave opening height as the primary factor determining the safety parameters for human activity. We thus conclude that depictions located in deep, dark halls with a small entrance height must have been created using minimal artificial light.

Chromatin conformations of HSP12 during transcriptional activation in the Saccharomyces cerevisiae stationary phase

During evolution, living cells have developed sophisticated molecular and physiological processes to cope with a variety of stressors. These mechanisms, which collectively constitute the Environmental Stress Response, involve the activation/repression of hundreds of genes that are regulated to respond rapidly and effectively to protect the cell. The main stressors include sudden increases in environmental temperature and osmolarity, exposure to heavy metals, nutrient limitation, ROS accumulation, and protein-damaging events. The growth stages of the yeast S. cerevisiae proceed from the exponential to the diauxic phase, finally reaching the stationary phase. It is in this latter phase that the main stressor events are more active. In the present work, we aim to understand whether the responses evoked by the sudden onset of a stressor, like what happens to cells going through the stationary phase, would be different or similar to those induced by a gradual increase in the same stimulus. To this aim, we studied the expression of the HSP12 gene of the HSP family of proteins, typically induced by stress conditions, with a focus on the role of chromatin in this regulation. Analyses of nucleosome occupancy and three-dimensional chromatin conformation suggest the activation of a different response pathway upon a sudden vs a gradual onset of a stress stimulus. Here we show that it is the three-dimensional chromatin structure of HSP12, rather than nucleosome remodeling, that becomes altered in HSP12 transcription during the stationary phase.

Design and Validation of Lifetime Prediction Model for Lithium-Thiocarbonyl Chloride Batteries Based on Accelerated Aging Experiments

The purpose of this study is to establish a life prediction model of lithium-thiocarbonyl chloride batteries by semi-empirical method. In the experiment, accelerated life tests on several groups of batteries at different temperatures were conducted. After a period of operation in the range from 25 °C to 74 °C, it was found that the higher the temperature, the less the remaining capacity of the batteries. According to the study of the battery aging mechanism, the characteristic parameter impedance of an aging battery would change exponentially with the increase of storage time and environmental temperature. The established life prediction model showed that the change in battery impedance spectrum had a good law, which made it possible to predict the state of charge (SOC) of the battery according to the local change characteristics of the electrochemical impedance spectroscopy (EIS) spectrum. The experimental data were compared with the fitted prediction curve, and the maximum deviation of the prediction was only 4.1036%, which indicated that the constructed model had high accuracy.

Chronic heat stress induces lung injury in broiler chickens by disrupting the pulmonary blood-air barrier and activating TLRs/NF-κB signaling pathway

As an important respiratory organ, the lung is susceptible to damage during heat stress due to the accelerated breathing frequency caused by an increase in environmental temperature. This can affect the growth performance of animals and endanger their health. This study aimed to explore the mechanism of lung tissue damage caused by heat stress. Broilers were randomly divided into a control group (Control) and a heat stress group (HS). The HS group was exposed to 35°C heat stress for 12 h per d from 21-days old, and samples were taken from selected broilers at 28, 35, and 42-days old. The results showed a significant increase in lactate dehydrogenase (LDH) activity in the serum and myeloperoxidase (MPO) activity in the lungs of broiler chickens across all 3 age groups after heat stress (P < 0.01), while the total antioxidant capacity (T-AOC) was significantly enhanced at 35-days old (P < 0.01). Heat stress also led to significant increases in various proinflammatory factors in serum and expression levels of HSP60 and HSP70 in lung tissue. Histopathological results showed congestion and bleeding in lung blood vessels, shedding of pulmonary epithelial cells, and a large amount of inflammatory infiltration in the lungs after heat stress. The mRNA expression of TLRs/NF-κB-related genes showed an upward trend (P < 0.05) after heat stress, while the mRNA expression of MLCK, a gene related to pulmonary blood-air barrier, significantly increased after heat stress, and the expression levels of MLC, ZO-1, and occludin decreased in contrast. This change was also confirmed by Western blotting, indicating that the pulmonary blood-air barrier is damaged after heat stress. Heat stress can cause damage to the lung tissue of broiler chickens by disrupting the integrity of the blood-air barrier and increasing permeability. This effect is further augmented by the activation of TLRs/NF-κB signaling pathways leading to an intensified inflammatory response. As heat stress duration progresses, broiler chickens develop thermotolerance, which gradually mitigates the damaging effects induced by heat stress.

Effects of fermentation chamber temperature on microbes and quality of cigar wrapper tobacco leaves.

The natural fermentation of cigar tobacco leaves usually utilizes natural temperature and humidity for fermentation. Cigars produced in China are often fermented in winter, and the low environmental temperatures can lead to slow heating of the tobacco stack, affecting the cigar tobacco leaves quality. This study aimed to determine the minimum chamber temperature required to initiate the process of fermentation for cigar tobacco leaves and to explore the impact of temperature on the microbial community of tobacco leaves. Here, the cigar variety "Dexue 1" were subjected to stacking fermentation under three temperature parameters (20 ℃, 27 ℃, 34 ℃). With an increase in environmental temperature, the temperature inside the stack of cigar leaves increased significantly, the protein, total sugar, starch, and total alkaloid content in fermented tobacco leaves decreased, and the aroma components and amino acid content increased. Microbial richness and community diversity associated with fermented tobacco were highest at chamber temperatures of above 27 ℃. The relative abundance of Chryseobacterium and Rhodococcus was significantly negatively correlated with protein, alkaloids, total sugar, and starch, and positively correlated with amino acids and aroma components. Chryseobacterium and Rhodococcus may be responsible for the degradation of macromolecular substances and the conversion of favorable aromatic substances, thus improving the tobacco leaves quality. This study demonstrated that increasing the fermentation chamber temperature above 27 ℃ was conductive to raising the inner-stack temperature, increased microbial diversity and aromatic quality, reduced the strength and irritation, and extremely enhanced the overall quality of fermented cigar tobacco leaves. KEY POINTS: • The environmental temperature of the fermentation chamber has a significant impact on the quality of tobacco • Temperature > 27 ℃ can initiate the process of cigar tobacco leaves fermentation and increase inner-stack temperature and microbial diversity and abundance • Chryseobacterium and Rhodococcus may be related to the degradation of macromolecular substances and the transformation of aromatic substances, thereby improving the quality of tobacco leaves.

Energy, exergy, sustainability and environmental emission analysis of coal-fired thermal power plant

Exergy analysis has recently gained importance in understanding process control and mechanism. Above-mentioned approach is detrimental in dealing with today’s stringent policies in energy security, saving, reclamation through various strategies. The current investigation is an integrated coal-fired thermal power plant, from which one-unit processes at 210 MW. Through the energy analysis, about 64.24% of the total energy loss in the installed condenser is the major equipment for energy destruction. From the evaluated exergy analysis, the major equipment, the boiler in the overall plant, has exergy destruction of 88.91%. From sustainability analysis infers that the generation system's high depletion number corresponds to a low SI between 1.546 and 1.594. With an increase in environment temperature from 25 °C to 45 °C, reduction of coal consumption and ash generation per unit fuel increases from 19.01 to 21.05 kg/h. Also, CO2 and SO2 emission reduction increases from 35.03 and 0.213 to 38.79 and 0.236 kg/h.

Worldwide comparison between the potential distribution of Rhipicephalus microplus (Acari: Ixodidae) under climate change scenarios.

The cattle tick Rhipicephalus microplus (Acari: Ixodidae) has demonstrated its ability to increase its distribution raising spatially its importance as a vector for zoonotic hemotropic pathogens. In this study, a global ecological niche model of R. microplus was built in different scenarios using Representative Concentration Pathway (RCP), Socio-Economic Pathway (SSP), and a climatic dataset to determine where the species could establish itself and thus affect the variability in the presentation of the hemotropic diseases they transmit. America, Africa and Oceania showed a higher probability for the presence of R. microplus in contrast to some countries in Europe and Asia in the ecological niche for the current period (1970-2000), but with the climate change, there was an increase in the ratio between the geographic range preserved between the RCP and SSP scenarios obtaining the greatest gain in the interplay of RCP4.5-SSP245. Our results allow to determine future changes in the distribution of the cattle tick according to the increase in environmental temperature and socio-economic development influenced by human development activities and trends; this work explores the possibility of designing integral maps between the vector and specific diseases.

Optimizing a Polycarboxylate Superplasticizer Molecular Structure to Reduce Apparent Viscosity of Cement Paste at Higher Environmental Temperatures

A high environmental temperature can increase the apparent viscosity of high-performance concrete mixtures, causing difficulties in mixing, transporting, pumping, and molding the mixtures. Although polycarboxylate ether–based superplasticizers (PCEs) have been proven effective in reducing the apparent viscosity of cement pastes, little work has focused on how PCEs with various molecular structures affect the apparent viscosity of high-performance concrete mixtures when environmental temperature increases. In this study, a PCE (T54C3.5), which was synthesized by reacting acrylic acid (AA) and isoprenyloxypoly (ethylene glycol) ether macromonomer (TPEG) (mw=2,400 g/mol) with a ratio equal to 3.5∶1, was used as the control group. Variations on the molecular structure of T54C3.5, including different carboxylate-to-macromonomer ratios, backbone lengths, backbone compositions, side-chain lengths, and side-chain compositions, were made to investigate the effectiveness of the various PCEs in changing the apparent viscosity of an ordinary portland cement paste with the water-to-cement ratio of 0.23 at different environmental temperatures. A rotational viscometer was used to measure the apparent viscosity of cement pastes containing different PCEs, and the working mechanisms for the effective PCEs were discussed. Results showed that reducing the backbone length was more effective than the other variations in improving the viscosity-reducing ability of PCEs at all tested temperatures. The PCEs containing ester bonds were able to retain or slightly decrease the viscosity of their cement pastes when the environment temperature increased from 20°C to 40°C. Reducing the backbone length and introducing ester groups are two effective ways of improving the viscosity-reducing ability of PCEs at a high environmental temperature. Using PCEs with these structures can significantly simplify the manufacturing processes of the cement mixtures with a low water-to-cement ratio when the environmental temperature increases from 20°C to 40°C, without any special mixing or casting method.