Supplementation of vitamin E or a botanical extract as antioxidants to improve growth performance and health of growing pigs housed under thermoneutral or heat-stressed conditions

Background Heat stress has severe negative consequences on performance and health of pigs,leading to significant economic losses.The objective of this study was to investigate the effects of supplemental vitamin E and a botanical extract in feed or drinking water on growth performance,intestinal health,and oxidative and immune status in grow-ing pigs housed under heat stress conditions.Methods Duplicate experiments were conducted,each using 64 crossbred pigs with an initial body weight of 50.7±3.8 and 43.9±3.6 kg and age of 13-week and 12-week,respectively.Pigs(n=128)were housed individually and assigned within weight blocks and sex to a 2×4 factorial arrangement consisting of 2 environments(thermo-neutral(21.2℃)or heat-stressed(30.9℃))and 4 supplementation treatments(control diet;control+100 IU/L of D-α-tocopherol in water;control+200 IU/kg of DL-α-tocopheryl-acetate in feed;or control+400 mg/kg of a botanical extract in feed).Results Heat stress for 28 d reduced(P≤0.001)final body weight,average daily gain,and average daily feed intake(-7.4 kg,-26.7%,and-25.4%,respectively)but no effects of supplementation were detected(P>0.05).Serum vitamin E increased(P<0.001)with vitamin E supplementation in water and in feed(1.64 vs.3.59 and 1.64 vs.3.24),but not for the botanical extract(1.64 vs.1.67 mg/kg)and was greater when supplemented in water vs.feed(P=0.002).Liver vitamin E increased(P<0.001)with vitamin E supplementations in water(3.9 vs.31.8)and feed(3.9 vs.18.0),but not with the botanical extract(3.9 vs.4.9 mg/kg).Serum malondialdehyde was reduced with heat stress on d 2,but increased on d 28(interaction,P<0.001),and was greater(P<0.05)for antioxidant supplementation compared to control.Cellular proliferation was reduced(P=0.037)in the jejunum under heat stress,but increased in the ileum when vitamin E was supplemented in feed and water under heat stress(interaction,P=0.04).Tumor necrosis factor-αin jejunum and ileum mucosa decreased by heat stress(P<0.05)and was reduced by vitamin E sup-plementations under heat stress(interaction,P<0.001).Conclusions The addition of the antioxidants in feed or in drinking water did not alleviate the negative impact of heat stress on feed intake and growth rate of growing pigs.

Milk production and composition and metabolic alterations in the mammary gland of heat-stressed lactating dairy cows

This experiment was conducted to investigate the effects of heat stress(HS) on the feed intake, milk production and composition and metabolic alterations in the mammary gland of dairy cows. Twenty Holstein cows were randomly assigned to one of two treatments according to a completely randomized design. Half of the cows were allocated to the HS group in August(summer season), and the other half were assigned to the HS-free group in November(autumn season). HS reduced(P<0.01) dry matter intake(DMI), milk yield, milk protein and milk urea nitrogen(MUN) of cows compared with HSfree control, but increased(P<0.01) milk somatic cell counts(SCC). We determined the HS-induced metabolic alterations and the relevant mechanisms in dairy cows using liquid chromatography mass spectrometry combined with multivariate analyses. Thirty-four metabolites were identified as potential biomarkers for the diagnosis of HS in dairy cows. Ten of these metabolites, glucose, lactate, pyruvate, lactose, β-hydroxybutyrate, citric acid, α-ketoglutarate, urea, creatine, and orotic acid, had high sensitivity and specificity for HS diagnoses, and seven metabolites were also identified as potential biomarkers of HS in plasma, milk, and liver. These substances are involved in glycolysis, lactose, ketone, tricarboxylic acid(TCA), amino acid and nucleotide metabolism, indicating that HS mainly affects lactose, energy and nucleotide metabolism in the mammary gland of lactating dairy cows. This study suggested that HS might affect milk production and composition by affecting the feed intake and substance metabolisms in the mammary gland tissue of lactating dairy cows.

Effects of Bupleurum extract on blood metabolism, antioxidant status and immune function in heat-stressed dairy cows

This experiment was conducted to evaluate the effects of Bupleurum extract （BE） on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were randomly assigned to 1 of 4 treatments. The treatments consisted of 0, 0.25, 0.5, and 1.0 g of BE kg-1 dry matter. Supplementation with BE decreased （P〈0.05） blood urea nitrogen （BUN） contents and increased blood total protein （TP） and albumin （ALB） levels compared with control cows, but it had no effects （P〉0.05） on blood glucose （GLU）, nonesterified fatty acid （NEFA）, total triglycedde （TG）, low-density lipoprotein cholesterol （LDL-C）, and high density lipoprotein cholesterol （HDL-C）. Compared with control cows, cows fed BE had higher （P〈0.05） superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） activity. However, supplementation with BE had no effect （P〉0.05） on total antioxidant capacity （T-AOC） or malondialdehyde （MDA） levels. The immunoglobulin （Ig） A and G contents increased （P〈0.05） in cows fed 0.25 or 0.5 g of BE kg-1. Interleukin （IL）-2 and IL-4 levels were higher （P〈0.05） in cows fed 0.5 and 1.0 g of BE kg-1, and IL-6 was significantly elevated （P〈0.05） in cows fed 0.5 g of BE kg-1. There were no treatment effects （P〉0.05） on the CD4＋ and CD8＋ T lymphocyte ratios, CD4＋/CD8＋ratio, or tumor necrosis factor-α （TNF-α） level among the groups. These findings suggest that BE supplementation may improve protein metabolism, in addition to enhancing antioxidant activity and immune function in heat-stressed dairy cows.

Predicting heat-stressed EEG spectra by self-organising feature map and learning vector quantizers——SOFM and LVQ based stress prediction

Self-Organising Feature Map (SOFM) along with learning vector quantizers (LVQ) have been designed to identify the alterations in brain electrical potentials due to exposure to high environmental heat in rats. Three groups of rats were considered—acute heat stressed, chronic heat stressed and control groups. After long EEG recordings following heat exposure, EEG data representing three different vigilance states such as slow wave sleep (SWS), rapid eye movement (REM) sleep and AWAKE were visually selected and further subdivided into 2 seconds long epoch. In order to evaluate the performance of artificial neural network (ANN) in recognizing chronic and acute effects of heat stress with respect to the control subjects, unsupervised learning algorithm was applied on EEG data. Mean performance of SOFM with quadratic taper function was found to be better (chronic-92.6%, acute-93.2%) over the other two tapers. The effect of LVQ after the initial SOFM training seems explicit giving rise to considerable improvements in performance in terms of selectivity and sensitivity. The percentage increase in selectivity with uniform taper function is maximum for chronic and its control group (4.01%) and minimum for acute group (1.29%) whereas, with Gaussian it is almost identical (chronic-2.57%, acute-2.03%, control- 2.33%). Quadratic taper function gives rise to an increase of 2.41% for chronic, 1.96% for acute and 2.91% for control patterns.

Optimum Profiles of Endwall Contouring for Enhanced Net Heat Flux Reduction and Aerodynamic Performance

Successfully utilized non-axisymmetric endwalls to enhance turbine efficiencies(aerodynamic and turbine inlet temperatures)by controlling the characteristics of the secondary flow in a blade passage.This is accomplished by steady-state numerical hydrodynamics and deep knowledge of the field of flow.Because of the interaction between mainstream and purge flow contributing supplementary losses in the stage,non-axisymmetric endwalls are highly susceptible to the inception of purge flow exit compared to the flat and any advantage rapidly vanishes.The conclusions reveal that the supreme endwall pattern could yield a lowering of the gross pressure loss at the design stage and is related to the size of the top-loss location being productively lowered.This has led to diminished global thermal exchange lowered in the passage of the vane alone.The reverse flow adjacent to the suction side corner of the endwall is migrated farther from the vane surface,as the deviated pressure spread on the endwall accelerates the flow and progresses the reverse flow core still downstream.The depleted association between the tornado-like vortex and the corner vortex adjacent to the suction side corner of the endwall is the dominant mechanism of control in the contoured end wall.In this publication,we show that the non-axisymmetric endwall contouring by selective numerical shape change method at most prominent locations is advantageous in lowering the thermal load in turbines to augment the net heat flux reduction as well as the aerodynamic performance using multi-objective optimization.

Optimal synthesis of heat-integrated distillation configurations using the two-column superstructure

In the realm of the synthesis of heat-integrated distillation configurations,the conventional approach for exploring more heat integration possibilities typically entails the splitting of a single column into a twocolumn configuration.However,this approach frequently necessitates tedious enumeration procedures,resulting in a considerable computational burden.To surmount this formidable challenge,the present study introduces an innovative remedy:The proposition of a superstructure that encompasses both single-column and multiple two-column configurations.Additionally,a simultaneous optimization algorithm is applied to optimize both the process parameters and heat integration structures of the twocolumn configurations.The effectiveness of this approach is demonstrated through a case study focusing on industrial organosilicon separation.The results underscore that the superstructure methodology not only substantially mitigates computational time compared to exhaustive enumeration but also furnishes solutions that exhibit comparable performance.

A coupled thermo-mechanical peridynamic model for fracture behavior of granite subjected to heating and water-cooling processes

Thermal damage and thermal fracture of rocks are two important indicators in geothermal mining projects.This paper investigates the effects of heating and water-cooling on granite specimens at various temperatures.The laboratory uniaxial compression experiments were also conducted.Then,a coupled thermo-mechanical ordinary state-based peridynamic(OSB-PD)model and corresponding numerical scheme were developed to simulate the damage of rocks after the heating and cooling processes,and the change of crack evolution process was predicted.The results demonstrate that elevated heating temperatures exacerbate the thermal damage to the specimens,resulting in a decrease in peak strength and an increase in ductility of granite.The escalating occurrence of thermal-induced cracks significantly affects the crack evolution process during the loading phase.The numerical results accurately reproduce the damage and fracture characteristics of the granite under different final heating temperatures(FHTs),which are consistent with the test results in terms of strength,crack evolution process,and failure mode.

The regulation of ferrocene-based catalysts on heat transfer in highpressure combustion of ammonium perchlorate/hydroxyl-terminated polybutadiene/aluminum composite propellants

The regulation of the burning rate pressure exponent for the ammonium perchlorate/hydroxylterminated polybutadiene/aluminum(AP/HTPB/Al)composite propellants under high pressures is a crucial step for its application in high-pressure solid rocket motors.In this work,the combustion characteristics of AP/HTPB/Al composite propellants containing ferrocene-based catalysts were investigated,including the burning rate,thermal behavior,the local heat transfer,and temperature profile in the range of 7-28 MPa.The results showed that the exponent breaks were still observed in the propellants after the addition of positive catalysts(Ce-Fc-MOF),the burning rate inhibitor((Ferrocenylmethyl)trimethylammonium bromide,Fc Br)and the mixture of Fc Br/catocene(GFP).However,the characteristic pressure has increased,and the exponent decreased from 1.14 to 0.66,0.55,and 0.48 when the addition of Ce-FcMOF,Fc Br and Fc Br/GFP in the propellants.In addition,the temperature in the first decomposition stage was increased by 7.50℃ and 11.40℃ for the AP/Fc Br mixture and the AP/Fc Br/GFP mixture,respectively,compared to the pure AP.On the other hand,the temperature in the second decomposition stage decreased by 48.30℃ and 81.70℃ for AP/Fc Br and AP/Fc Br/GFP mixtures,respectively.It was also found that Fc Br might generate ammonia to cover the AP surface.In this case,a reaction between the methyl in Fc Br and perchloric acid caused more ammonia to appear at the AP surface,resulting in the suppression of ammonia desorption.In addition,the coarse AP particles on the quenched surface were of a concave shape relative to the binder matrix under low and high pressures when the catalysts were added.In the process,the decline at the AP/HTPB interface was only exhibited in the propellant with the addition of Ce-Fc-MOF.The ratio of the gas-phase temperature gradient of the propellants containing catalysts was reduced significantly below and above the characteristic pressure,rather than 3.6 times of the difference in the blank propellant.Overall,the obtained results demonstrated that the pressure exponent could be effectively regulated and controlled by adjusting the propellant local heat and mass transfer under high and low pressures.

Low-energy-consumption temperature swing system for CO_(2) capture by combining passive radiative cooling and solar heating

Temperature-swing adsorption(TSA)is an effective technique for CO_(2) capture,but the temperature swing procedure is energy-intensive.Herein,we report a low-energy-consumption system by combining passive radiative cooling and solar heating for the uptake of CO_(2) on commercial activated carbons(CACs).During adsorption,the adsorbents are coated with a layer of hierarchically porous poly(vinylidene fluoride-co-hexafluoropropene)[P(VdF-HFP)HP],which cools the adsorbents to a low temperature under sunlight through radiative cooling.For desorption,CACs with broad absorption of the solar spectrum are exposed to light irradiation for heating.The heating and cooling processes are completely driven by solar energy.Adsorption tests under mimicked sunlight using the CACs show that the performance of this system is comparable to that of the traditional ones.Furthermore,under real sunlight irradiation,the adsorption capacity of the CACs can be well maintained after multiple cycles.The present work may inspire the development of new temperature swing procedures with little energy consumption.

Overall Performance, Carcass Yield, Meat Safety Potentials and Economic Value of Heat-Stressed Broilers Fed Diets with Balanced Electrolytes

Tropical regions across the globe are characterized by an annually prolonged hot weather conditions that showcase limiting production efficiency in livestock industry, as domesticated animals leave the zone of maximum comfort, under heat stress, with death and reduced carcass yield accompanying the subsequent alteration in body chemistry and behavior. However, pen house orientation, cooling systems, genetic modification and different dietary manipulations have been employed in poultry industry, but many of such did not account for the body’s acid-base equilibrium and the potentials of aggregate levels of dietary electrolytes in enhancing carcass yield of broilers under severe heat stress conditions. Therefore, this study was conducted to investigate the effects of different electrolyte-balanced diets on overall performance, carcass yield, meat safety potentials and economic value of heat-stressed broilers reared for five weeks. Arbor Acre broiler chicks (n = 300) were randomly allotted to diets with aggregate electrolyte balance of 210 (T1), 240 (T2), 270 (T3), 300 (T4), 330 (T5) and 360 (T6) mEq/Kg, in a completely randomised design. On day 35, birds whose weights were closest to the mean class weight were selected from each replicate pen for carcass yield assessment. Also, data on performance and cost-benefit analysis were analysed using descriptive statistics and ANOVA at α = 0.05. Electrolyte-balanced diets though contained salts that presumably could have improved satiety, yet they do not enhance appetite in heat-stressed broilers. However, dietary protein efficiency was enhanced at an electrolyte balance levels of 240 and 270 mEq/kg, which translated into increased body weight gain. Weights of primal parts of birds on 270 mEq/kg DEB were highest at 35 days. Feed cost values (per kilogram weight gain) of rations with 240 mEq/kg and 270 mEq/kg DEB were lower and showcased promising economic buoyancy to both rural and commercial poultry farmers, while ensuring a high food safety standard under tropical conditions.

A particle-resolved heat-particle-fluid coupling model by DEM-IMB-LBM

Multifield coupling is frequently encountered and also an active area of research in geotechnical engineering.In this work,a particle-resolved direct numerical simulation(PR-DNS)technique is extended to simulate particle-fluid interaction problems involving heat transfer at the grain level.In this extended technique,an immersed moving boundary(IMB)scheme is used to couple the discrete element method(DEM)and lattice Boltzmann method(LBM),while a recently proposed Dirichlet-type thermal boundary condition is also adapted to account for heat transfer between fluid phase and solid particles.The resulting DEM-IBM-LBM model is robust to simulate moving curved boundaries with constant temperature in thermal flows.To facilitate the understanding and implementation of this coupled model for non-isothermal problems,a complete list is given for the conversion of relevant physical variables to lattice units.Then,benchmark tests,including a single-particle sedimentation and a two-particle drafting-kissing-tumbling(DKT)simulation with heat transfer,are carried out to validate the accuracy of our coupled technique.To further investigate the role of heat transfer in particle-laden flows,two multiple-particle problems with heat transfer are performed.Numerical examples demonstrate that the proposed coupling model is a promising high-resolution approach for simulating the heat-particle-fluid coupling at the grain level.

Effects of EGCG on Liver Antioxidation and Fat Metabolism in Heat-stressed Broilers

This study aims to investigate the effects of EGCG on the lipid deposition and liver anti-oxidative capacity of broilers under heat stress.One hundred and ninety-two 2-week-old broilers were divided into four groups with 6 replicates per group and 8 chickens per replicate:one thermoneutral control group(28℃,TN group),which was fed the basal diet,and three cyclic high-temperature groups(35℃from 7:00 to 19:00 h;28℃from 19:00 h to 7:00 h,heat stress(HS)group),which were fed the basal diet added with EGCG at doses of 0(HS0 group),300(HS300 group),and 600 mg/kg(HS600 group),respectively.The liver metabolism and lipid deposition indices were performed at 35 d of age.The results showed that heat stress decreased the activities of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px),and the Nrf2 mRNA expression in liver,and increase significantly the levels of malondialdehyde(MDA)and the expression of LITAF,NF-KB,FAS,SREBP1 mRNA and the lipid deposition compared with TN group.EGCG(HS300 and HS600 group)increased the activities of SOD and GSH-Px and catalase(CAT),increased the Nrf2 mRNA expression,decreased the MDA contents,and reduced the lipid deposition and expression of LITAF,NF-KB,FAS and SREBP1 mRNA.In conclusion,the results of this study show that EGCG can improve liver antioxidative capacity to alleviate oxidative damage caused by heat stress.

A comprehensive review on microchannel heat sinks for electronics cooling

The heat generation of electronic devices is increasing dramatically,which causes a serious bottleneck in the thermal management of electronics,and overheating will result in performance deterioration and even device damage.With the development of micro-machining technologies,the microchannel heat sink(MCHS)has become one of the best ways to remove the considerable amount of heat generated by high-power electronics.It has the advantages of large specific surface area,small size,coolant saving and high heat transfer coefficient.This paper comprehensively takes an overview of the research progress in MCHSs and generalizes the hotspots and bottlenecks of this area.The heat transfer mechanisms and performances of different channel structures,coolants,channel materials and some other influencing factors are reviewed.Additionally,this paper classifies the heat transfer enhancement technology and reviews the related studies on both the single-phase and phase-change flow and heat transfer.The comprehensive review is expected to provide a theoretical reference and technical guidance for further research and application of MCHSs in the future.

Operation optimization of prefabricated light modular radiant heating system:Thermal resistance analysis and numerical study

The utilization of prefabricated light modular radiant heating system has demonstrated significant increases in heat transfer efficiency and energy conservation capabilities.Within prefabricated building construction,this new heating method presents an opportunity for the development of comprehensive facilities.The parameters for evaluating the effectiveness of such a system are the upper surface layer’s heat flux and temperature.In this paper,thermal resistance analysis calculation based on a simplified model for this unique radiant heating system analysis is presented with the heat transfer mechanism’s evaluation.The results obtained from thermal resistance analysis calculation and numerical simulation indicate that the thermal resistance analysis method is highly accurate with temperature discrepancies ranging from 0.44℃ to−0.44℃ and a heat flux discrepancy of less than 7.54%,which can meet the requirements of practical engineering applications,suggesting a foundation for the prefabricated radiant heating system.

Research on shell-side heat and mass transfer with multi-component in LNG spiral-wound heat exchanger under sloshing conditions

The spiral-wound heat exchanger(SWHE) is the primary low-temperature heat exchanger for large-scale LNG plants due to its high-pressure resistance, compact structure, and high heat exchange efficiency. This paper studied the shell-side heat and mass transfer characteristics of vapor-liquid two-phase mixed refrigerants in an SWHE by combining a multi-component model in FLUENT software with a customized multicomponent mass transfer model. Besides, the mathematical model under the sloshing condition was obtained through mathematical derivation, and the corresponding UDF code was loaded into FLUENT as the momentum source term. The results under the sloshing conditions were compared with the relevant parameters under the steady-state condition. The shell-side heat and mass transfer characteristics of the SWHE were investigated by adjusting the component ratio and other working conditions. It was found that the sloshing conditions enhance the heat transfer performance and sometimes have insignificant effects. The sloshing condition is beneficial to reduce the flow resistance. The comprehensive performance of multi-component refrigerants has been improved and the improvement is more significant under sloshing conditions, considering both the heat transfer and pressure drop.These results will provide theoretical support for the research and design of multi-component heat and mass transfer enhancement of LNG SWHE under ocean sloshing conditions.

How Does Heat-Stress Intensity Affect the Stability of Microbial Activity and Diversity of Soil Microbial Communities in Outfields and Homefields’ Cultivation Practices in the Senegalese Groundnut Basin?

Agroecosystems in the Senegalese groundnut basin experience long periods of high temperatures and drought, which disrupt the stability of soil microbial communities. This study evaluated how that stability is affected by homefields and outfields’ agricultural practices and the duration of heat stress. Specifically, we collected soils from organically farmed fields that receive continual high inputs of manure (homefields), and from fields that are rarely manured (outfields). Soil samples were submitted to artificial heat stress at 60°C for 3, 14, and 28 days, followed by 28 days of recovery at 28°C. We examined the functional stability of microbial communities by quantifying C mineralization, and characterized the stability of the communities’ taxonomic compositions via high-throughput DNA sequencing. We found that the microbial communities have a low resistance to heat stress in soils from both types of fields. However, the manuring practice does affect how the functional stability of microbial communities responds to different durations of heat stress. Although functional stability was not recovered fully in either soil, microbial community resilience seemed to be greater in homefield soils. Differences in manuring practices also affected the structural taxonomic stability of microbial communities: relative abundances of Bacilli, Chloroflexia, Actinobacteria and Sordariomycetes increased in the homefield stressed-soils, but decreased significantly in outfield soils. In contrast, relative abundances of α-Proteobacteria, γ-Proteobacteria and Eurotiomycetes increased significantly in outfield stressed-soils, while decreasing significantly in the homefield soils. Relative abundances of Bacilli changed little in outfield soils, indicating that this taxon is resistant to heat stress. In summary, the microbial communities’ capacities to resist heat stress and recover from it depend upon the organic richness of the soil (i.e., manuring practice) and the adaptation of soil microbes to environmental conditions.

Ion heat transport in electron cyclotron resonance heated L-mode plasma on the T-10 tokamak

Anomalous ion heat transport is analyzed in the T-10 tokamak plasma heated with electron cyclotron resonance heating(ECRH) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that in ECRH plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport is required. To study this effect two scans are presented: over the EC resonance position and over the ECRH power. The EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. The scan over the heating power is presented with on-axis and mixed ECRH regimes. Discharges with high anomalous ion heat transport are obtained in all considered regimes. In these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. The high ion heat transport regimes are distinguished by three parameters: the ratio Te/Ti, the normalized electron density gradient R/■, and the ion–ion collisionality νii~*. The combination of high Te/Ti, high νii~*, and R/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.

Web GIS-Based Temporal Analysis of Climatic Factors Impacting Heat Stroke in Karachi

This study focuses on the impact of climate change, specifically the increasing threat of heatwaves, in Pakistan, with a particular emphasis on the city of Karachi. The Pakistan Meteorological Department (PMD) analysed a century of climatic data to reveal warming trends, attributing them to human-induced factors. The vulnerability of Pakistan to climate change is highlighted, given its warm climate and location in a region where temperature increases are expected to surpass global averages. The study examines the past three decades, noting a significant rise in the frequency of hot days, especially in Karachi, where heatwaves have become more prevalent. The aims and objectives of the study involve identifying temporal changes in temperature, rainfall, humidity, and wind speed from 1984 to 2014 in Karachi. The literature review emphasizes the health implications of heatwaves, citing increased mortality during such events globally. The study incorporates a comprehensive temporal analysis, addressing gaps in previous research by considering multiple climate indicators responsible for heatwaves. The methodology involves statistical analyses, including linear regression and Pearson correlation, applied to temperature data and urbanization parameters. Results indicate an increasing trend in heat index temperature, with heatwave vulnerability peaking in the last three decades. Heat Index Temperature Anomalies show a clear surge, emphasizing the need for new indices to control critical heat stress conditions. The study concludes that tropical climate variability, particularly heat index, is linked to extreme hot days, urging measures to reduce population vulnerability. The findings underscore the importance of policy strategies, such as integrated coastal zone management, to mitigate the adverse health effects of heatwaves in Karachi’s vulnerable population.

Impact of Dietary Lactobacillus plantarum Postbiotics on the Performance of Layer Hens under Heat Stress Conditions

This experiment was conducted to determine the performance of heat-stressed layers fed a diet containing the probiotic Lactobacillus plantarum RS5 or its products of fermentation (postbiotics). Twenty-week-old Isa White layers, were subdivided into six treatments of 32 individually caged birds. Half of the birds were reared under regular temperature conditions, while the other half was subjected to cyclic daily heat stress. Layers were offered one of three diets: 1) Control;2) Control + Lactobacillus plantarum RS5 probiotic;3) Control + Lactobacillus plantarum RS5 postbiotics. Birds were tested for performance and visceral organ development for 5 months. Heat stress negatively affected the birds’ feed intake, egg weight, shell weight percentage, Haugh unit, shell thickness, yolk color, body weight and spleen weight percentage. Postbiotics significantly increased egg production (p < 0.05) in comparison to the control and the probiotic fed group (94.8% vs 92.6% vs 93.1%, respectively). Birds under probiotic or postbiotic diet showed a significantly higher (p < 0.05) feed intake and egg weight, although the probiotic had a more pronounced and gradual effect. Specific gravity, yolk weight percentage and shell thickness didn’t show differences among dietary groups. The Haugh Unit was significantly higher (p < 0.05) in probiotic group which also showed a significantly lower yolk color index (p < 0.05). The different feed treatments did not impact the bird’s viscera weight percentage, except for the ileum that was significantly lower (p < 0.05) under postbiotic supplementation. Both probiotics and postbiotics could be used as a potential growth promoters and might alleviate heat stress impact in poultry industry.

Paraffin–CaCl_(2)·6H_(2)O dosage effects on the strength and heat transfer characteristics of cemented tailings backfill

The challenge of high temperatures in deep mining remains harmful to the health of workers and their production efficiency The addition of phase change materials (PCMs) to filling slurry and the use of the cold storage function of these materials to reduce downhole temperatures is an effective approach to alleviate the aforementioned problem.Paraffin–CaCl_(2)·6H_(2)O composite PCM was prepared in the laboratory.The composition,phase change latent heat,thermal conductivity,and cemented tailing backfill (CTB) compressive strength of the new material were studied.The heat transfer characteristics and endothermic effect of the PCM were simulated using Fluent software.The results showed the following:(1) The new paraffin–CaCl_(2)·6H_(2)O composite PCM improved the thermal conductivity of native paraffin while avoiding the water solubility of CaCl_(2)·6H_(2)O.(2) The calculation formula of the thermal conductivity of CaCl_(2)·6H_(2)O combined with paraffin was deduced,and the reasons were explained in principle.(3) The“enthalpy–mass scale model”was applied to calculate the phase change latent heat of nonreactive composite PCMs.(4)The addition of the paraffin–CaCl_(2)·6H_(2)O composite PCM reduced the CTB strength but increased its heat absorption capacity.This research can give a theoretical foundation for the use of heat storage backfill in green mines.