Effect Of Ambient Temperature Research Articles

Effects of ambient temperature on drivers’ speed-selective behavior at different risk levels: A driving simulation study

Abnormal or inappropriate ambient conditions can lead to reduced driving performance or even crashes, and the ambient temperature could be the most critical and fundamental factor. However, the coupling effects of the ambient temperature and the road and traffic conditions on basic speed-selection behavior are rarely investigated. To this end, this study attempted to evaluate drivers’ speed-selective behavior at low-medium-high risk levels under the low (16 °C ± 2 °C), medium (26 °C ± 2 °C), and high (36 °C ± 2 °C) ambient temperature ranges. To achieve this, a series of driving simulation experiments were conducted with 45 participants. Results showed that, at the low-risk level, the limitations of low-temperature or high-temperature conditions resulted in higher average speed than the medium-temperature condition. At the medium-risk level, the driver’s dynamic speed adjustment behavior was degraded under low-temperature or high-temperature conditions, and the deceleration rate was higher than the medium-temperature condition. At the high-risk level, drivers failed to diminish their speed in a timely way under low-temperature or high-temperature conditions, increasing the risk of crashes. However, decreasing the speed at the point of conflict could be effective in reducing the severity of the collision. The findings of this study can be applied to autonomous vehicles (AVs) to search for better safety countermeasures.

The effects of ambient temperature on non-accidental mortality in the elderly hypertensive subjects, a cohort-based study

BackgroundThe association between ambient temperature and mortality has yielded inconclusive results with previous studies relying on in-patient data to assess the health effects of temperature. Therefore, we aimed to estimate the effect of ambient temperature on non-accidental mortality among elderly hypertensive patients through a prospective cohort study conducted in northeastern China.MethodsA total of 9634 elderly hypertensive patients from the Kailuan research who participated in the baseline survey and follow-up from January 1, 2006 to December 31, 2017, were included in the study. We employed a Poisson generalized linear regression model to estimate the effects of monthly ambient temperature and temperature variations on non-accidental mortality.ResultsAfter adjusting for meteorological parameters, the monthly mean temperature (RR = 0.989, 95% CI: 0.984–0.993, p < 0.001), minimum temperature (RR = 0.987, 95% CI: 0.983–0.992, p < 0.001) and maximum temperature (RR = 0.989, 95% CI: 0.985–0.994, p < 0.001) exhibited a negative association with an increased risk of non-accidental mortality. The presence of higher monthly temperature variation was significantly associated with an elevated risk of mortality (RR = 1.097, 95% CI:1.051–1.146, p < 0.001). Further stratified analysis revealed that these associations were more pronounced during colder months as well as among male and older individuals.ConclusionsDecreased temperature and greater variations in ambient temperature were observed to be linked with non-accidental mortality among elderly hypertensive patients, particularly notable within aging populations and males. These understanding regarding the effects of ambient temperature on mortality holds clinical significance for appropriate treatment strategies targeting these individuals while also serving as an indicator for heightened risk of death.

Uniaxial compression stress–strain relationship of fully aeolian sand concrete at low temperatures

Abstract The aim of this study is to investigate the impact of various ambient temperatures on the mechanical properties of full aeolian sand concrete (ASC100). Using ordinary concrete (ASC0) as the control group, we analyzed the effects of different ambient temperatures (−20, −15, −10, −5, 0, and 20°C) on the mechanical properties of both ASC0 and ASC100 through cube compression, splitting tensile, and uniaxial compression tests. The results demonstrate that the compressive strength and splitting tensile strength of concrete cubes increased with decreasing temperature. At −20°C, the compressive strength of ASC100 increased by 30.1% and that of ASC0 increased by 27.31% compared to that at 20°C. Additionally, compared to normal temperatures, the elastic modulus of ASC0 and ASC100 at subzero temperatures increased by 28.2–61.4% and 6.8–65.7%, respectively, while the peak stress increased by 7–35% and 6.8–38%, respectively. The stress–strain curve of ASC100 showed three stages: elastic, elastic-plastic, and yield failure, serving as the reference group. Finally, based on the classical constitutive model, we modified the constitutive parameters by axial compressive strength and temperature, proposing a constitutive model of concrete suitable for different low-temperature environments, which is in good agreement with experimental data.

The effects of zinc citrate, selenium citrate, and germanium citrate on hematological parameters of rabbits under heat stress

Background. The environmental crisis has affected the annual ambient tempera­ture increase, adversely affecting the mammalian body. Due to their lack of sweat glands, Rabbits are more sensitive to heat stress than other animals. The effect of elevated ambient temperatures on the rabbit body leads to violations of blood parame­ters, endocrine regulation, immune and reproductive function, which reduces their productivity and increases animal mortality. Particular attention is now paid to the study of organic compounds of trace elements, which are characterized by high physiological activity, are non-toxic, have a wide range of biological effects, and have a positive impact on reducing the negative effect of elevated ambient temperatures on animals. However, their action depends on the element and its applied quantity. Therefore, the main objective of this study was to investigate the effect of zinc citrate, selenium citrate, and germanium citrate on changes in the number of blood cells in rabbits to mitigate the effects of heat stress. Materials and methods. The studies were conducted on young analog rabbits of the Termon White breed from 35 to 78 days of age. The rabbits were kept indoors at elevated ambient temperatures from 28.9 to 30 °C and relative humidity from 78.1 to 87.4 %. Animals of the control group were kept on the main diet with feeding of standard balanced granulated compound feed and water without restriction. Rabbits of groups I, II, and III of the study groups consumed the same compound feed as in control, but within 24 hours, they received water: group I – zinc citrate – 60 mg Zn/L or 12 mg Zn/kg of body weight; group II – selenium citrate – 300 μg Se/L or 60 μg Se/kg of body weight; group III – germanium citrate – 62.5 μg Ge/L or 12.5 μg Ge/kg of body weight. Using individual drinkers for each animal and placing the animals in different cages allowed us to control the amount of water consumed by each rabbit. Blood for the study was selected for supplementation on the 14th day of the prepara­tory period and the 14th and 29th days of the study period. During the study period, the room temperature was monitored, taking into account the temperature and humidity index. Results. The addition of micronutrient citrates to the diet of rabbits during 29 days of study under heat stress caused haematological changes in indicators compared to the control: the number of erythrocytes in the blood of rabbits of experimental groups I and II increased by 16.4 and 13.6 % and 19.9 and 14.5 % on day 14 and 29, respectively, in group III by 15.3 % on day 14; the haemoglobin content of groups I, II and III increased by 20.8, 21.6 and 19.5 % on day 14 and 11.1, 12.5 and 9.7 % on day 29; haematocrit value of groups I and II increased by 24.1 and 15.7 % and 21.1 and 16.5 % during the study, group III by 18.6% on day 14; the number of leukocytes of groups I, II and III decreased by 13.1 and 8.3 %; 11.2 and 10.4 % and by 11.4 and 9.3 % on days 14 and 29; the number of lymphocytes of groups I, II and III decreased by 25.9, 27.3 and 29.0 % on day 14 and by 20.4, 21.7 and 16.0 % on day 29; the number of monocytes of groups I and II increased by 14.8 and 21.3 % and 17.0 and 18.3 % over 29 days; the number of platelets in animals of group II decreased by 29.4 % on day 29, the average volume of red blood cells increased by 11.6 and 14.6 % on days 14 and 29 of the experiment. Conclusions. Adding micronutrient citrates to the rabbit diet mitigated the effects of heat stress on the body. The effect of these additives on animals resulted in significant changes in the hematological parameters of the rabbits’ blood, of which the best results were observed under the influence of selenium citrate (60 μg Se/kg body weight) and zinc citrate (12 mg Zn/kg body weight): red blood cell count (p &lt;0.05–0.01), leukocyte (p &lt;0.05–0.01), lymphocyte (p &lt;0.05–0.01), monocyte (p &lt;0.05–0.01), haemoglobin content (p &lt;0.01–0.001), haematocrit value (p &lt;0.01), compared to the control. Feeding germanium citrate led to less pronounced changes in these blood parameters.

Effect of temperature and relative humidity on the moisture recovery and specific resistance of yak hair fiber

This study measured the moisture regain and specific resistance values of yak hair fiber in a humidified environment to provide a theoretical basis for the development and utilization of yak hair fiber in the fields of textile, electronics and manufacturing. The effects of temperature and relative humidity on moisture absorption and electrical resistance of yak hair fiber were measured, and the effects of ambient temperature and humidity on the moisture regain and specific resistance of yak hair fiber were evaluated when using a new type of water-cooled textile air conditioner as a humidifying device, and the amino acid structure and crystallinity were compared between yak hair fiber and wool fiber. The experimental results show that temperature and relative humidity have a greater effect on the moisture regain rate and specific resistance value of the fiber, and the higher the temperature and relative humidity, the higher the moisture regain rate of yak hair fiber and the lower the specific resistance. When the temperature was 30 °C and the relative humidity was 85%, the fiber had the lowest specific resistance value and the highest moisture return rate. In terms of amino acid species, there is not much difference in chemical structure between yak hair fiber and wool fiber. The crystallinity of yak hair fiber is lower than that of wool fiber.

Impact of curing conditions on the mechanical properties and micro characteristics of alkali-activated material synthesized from industrial waste soda residue

Alkali-activated materials (AAM) are considered a type of green cementitious material because they are produced without the grinding and calcining required for cement production, significantly reducing carbon emissions. However, their production typically involves the use of commercial alkalis, which are often corrosive, irritating, and expensive. As an industrial waste from sodium carbonate production, soda residue (SR) has a large reserve and is challenging to dewater and utilize, making its disposal a widespread technical challenge. In this paper, considering the alkaline nature and high salt content of SR, a soda residue activated granulated blast-furnace slag cementitious material (SAG) was synthesized directly using undried and unground SR slurry as the alkali activator, with a mass ratio of SR to granulated blast-furnace slag (GBFS) of 30:70. The effects of ambient temperature (AT) curing, water curing, various heat curing temperatures (45°C, 60°C, 75°C, and 90°C), and different heat curing durations (6 h, 12 h, 18 h, and 24 h) on the properties of SAG were investigated. Specifically, the effect of curing conditions on the mechanical properties of SAG was analyzed through unconfined compressive strength (UCS) testing of mortar specimens. The impact of curing conditions on the phase composition and changes in SAG was characterized using XRD, TG, and FTIR, while the effect on the microstructure of SAG was characterized using SEM. The results showed that SAG achieved the highest UCS (3 d/56 d: 28.1 MPa/36.7 MPa) when subjected to heat curing at 75°C for 12 h. The UCS increased significantly by 3022 % and 321 %, respectively, compared to those under AT sealed curing. This was attributed to the fact that SAG under heat curing produced more C-(A)-S-H gels and hydrocalumite crystals, optimizing pore structure and resulting in a denser microstructure. However, exceeding the threshold temperature of 75°C led to an excessively rapid hydration reaction that adversely affected the further dissolution of GBFS and the uniform distribution of hydration products, thereby diminishing the positive effects of heat curing on UCS. In addition, excessively prolonging the heat curing time exacerbated the development of microcracks within the SAG, leading to a deterioration of UCS over age. In this paper, a novel AAM was synthesized using undried and unground industrial waste without the addition of commercial alkali, and the impact of curing conditions on their properties was studied. This broadens the range of applications for SAG, fills a gap in research on the impact of curing conditions on AAM without commercial alkali, and provides a theoretical basis for the low-carbon utilization of industrial waste.

Wheel tread temperature assessment and its impact on rolling contact fatigue under long-term braking conditions

To analyze the temperature rise of the wheel tread under braking conditions and its impact on the rolling contact fatigue (RCF) of the wheels, this paper proposes a numerical analysis method based on thermodynamics, material mechanics, and wheel-rail contact mechanics. This method has features of simplicity and fast computing speed. The study shows that the temperature rise of the wheel tread is mainly affected by the thermal friction between the brake pad and the wheel tread. The effects of track gradient, braking speed, and ambient temperature on wheel tread temperature rise are 16 °C/‰, 9.4 °C/km h⁻¹ , and 10 °C/°C, respectively. Therefore, reducing the gradient of the track, locomotive braking speed, and braking duration can help reduce the wheel tread temperature, thereby slowing the development of RCF of the wheels. The study shows that the value of RCF considering the temperature rise of the wheel tread is about 1.55 times that without considering the temperature rise, while the value of wear damage is reduced by 23 %. Therefore, when analyzing wheel damage, the comprehensive effects of RCF, wear, plastic flow, and temperature are recommended to be considered from different angles to provide a basis for reducing wheel damage.

Association of ambient temperature with intentional self-harm and suicide death in Seoul: a case-crossover design with a distributed lag nonlinear model.

Previous epidemiological studies have reported a short-term association between ambient temperature and suicide risk. To gain a clearer understanding of this association, it is essential to differentiate the risk factors for intentional self-harm (ISH) from those specifically associated with suicide deaths. Therefore, this study aims to examine whether the association between daily temperature and ISH or suicide deaths differs by age and sex. Between 2014 and 2019, cases of emergency room visits related to ISH and suicide deaths in Seoul were identified. A time-stratified case-crossover design was used to adjust for temporal trends and seasonal variation. A distributed lag nonlinear model was used to analyze the nonlinear and time-delayed effect of ambient temperature on ISH and suicide deaths. Positive associations were observed between temperature and both ISH and suicide deaths. For ISH, the relative risk (RR) was high at 1.17 (95% confidence interval (CI): 1.03, 1.34) for a temperature of 25.7°C compared with 14.8°C. The RR for suicide death was higher than those for ISH, at 1.43 (95% CI: 1.03, 2.00) for a temperature of 33.7°C. These associations varied by age and sex, with males and females aged 35-64 years showing increased susceptibility to suicide deaths. This study provides detailed evidence that unusually high temperatures, both anomalous and out of season, may trigger suicidal behaviors, including both ISH and suicide deaths.

Impact resistance and energy absorption characteristics of nickel-based alloy ring at elevated temperatures

To evaluate the high-temperature containment capability of a turbine casing, the impact resistance of half-ring specimens and full circular casings made of GH4169 nickel-based alloy was investigated. Ballistic impact tests were first conducted on GH4169 half-ring specimens using blade-shaped projectiles of DZ125 material fired from a single-stage gas gun. Meanwhile, explicit finite element simulations of the half-ring impact tests were performed with LS-DYNA. Comparing experimental and simulation results validated the accuracy of the model and revealed the effects of impact angle and ambient temperature. Then the process of a turbine casing containing a blade at 500 °C was simulated using the validated FE model. The results showed that the impact angle and the ambient temperature significantly affect the impact resistance of GH4169 half-ring specimen. Furthermore, the interaction mechanism between the turbine blade and casing differs across the three stages of the containment process.

The effect of non-optimal ambient temperature on daily mortality in Colombia 2010-2019

The effect of non-optimal ambient temperature on daily mortality in Colombia 2010-2019

Spatial heterogeneity in the acute effects of ambient air pollution and temperature on pediatric seizures and epilepsy across New York

Spatial heterogeneity in the acute effects of ambient air pollution and temperature on pediatric seizures and epilepsy across New York

Study on performance of a multi-heat source heat pump coupled energy storage system for plant factory heating system

CO2 air source heat pump (CASHP) faces challenges of performance degradation caused by the high return water temperature and the low ambient temperature for building heating. This study proposed a novel multi-heat source heat pump system (MHSHP) that combined with a CO2 air source heat pumps (CASHP) and ground source heat pumps (GSHP) with the implementation of a thermal storage tank. The performance and CO2 emissions of both CASHP and MHSHP systems were investigated by applying a plant factory located in Beijing, China. The effects of user-side parameters and ambient temperature were explored with the storage water temperatures ranging from 20 °C to 40 °C. The results demonstrated that the heating performance of the CASHP improved with an increase of user water flow rate and ambient temperatures, while it decreased as the storage water temperature increased. At the flow rate of 1.1 m3/h, the increase of the compressor frequency from 40 Hz to 60 Hz led to a significant improvement in heating capacity by 53.3 %, and a reduction in COP by 23.3 %. When the user-side water flow ratio decreased or the total flow rate increased, the COP of the MHSHP system showed improvement and outperformed that of the CASHP system, with an increase ranging from 46.9 % to 61.5 %. Additionally, it exhibits reduced sensitivity to ambient temperature fluctuations, resulting in a decrease in COP variability from 33.3 % to 20.6 %. Moreover, the CO2 emissions of the system decrease as the COP increases, with significant reduction of 69.2 %.

Short-term Effects of Ambient Temperature on Pediatric Incident Seizure: A Case-crossover Analysis Using Distributed Lag Non-linear Models

Short-term Effects of Ambient Temperature on Pediatric Incident Seizure: A Case-crossover Analysis Using Distributed Lag Non-linear Models

A Thermal Tanks-in-Series Model for Simulating over-Discharge Cycling in Lithium-Ion Batteries

Energy storage will play a crucial role in the transition to clean and renewable sources of energy production to meet future consumption demands.1 Lithium-ion (Li-ion) batteries are widely adopted due to their high energy density, low self-discharge rate and fast charging capabilities for applications like electric vehicles and grid storage.2 Li-ion batteries for high voltage operations, where several cells are connected in series, can experience inadvertent over-discharge due to differences between cells3,4. These differences can arise due to many reasons including changes in internal resistance and deviation in electrochemical degradation that can cause divergence of cell open circuit potentials. Over-discharge is a condition when the manufacturer recommended lower voltage limit is crossed while discharging4, which results in various side effects such as electrolyte decomposition, capacity degradation, cathode morphology change and possible internal short circuit3,5. Increase in anode potential during over-discharge leads to copper dissolution from the anode current collector and subsequent plating within cell components. The Solid Electrolyte Interface (SEI) can decompose during excessive deintercalation and reform during charging, reducing the lithium inventory. Excessive heat generation during cycle life testing after occurrences of over-discharges has been found in some cases to lead to temperatures >150 °C6,7.Temperature plays a key role in the electrochemical performance of individual cells, affecting the diffusivities of ions, kinetics of reactions and rate of degradation of the battery. A physics-based modeling approach coupled with a thermal model can be employed to understand the effect of over-discharge on the electrochemical behavior of Li-ion batteries and provides insights into the interplay of various degradation mechanisms that cause capacity fade.The Thermal Tank-In-Series9,10(TTiS) model is a systematically volume-averaged form of the standard pseudo-2-dimensional (p2D)11 model with energy balance equations for the current collectors, cathode, separator and anode. This reduces the number of equations in the model and improves computational speed while maintaining accuracy, as it is sensitive to changes in the battery’s state of charge (SOC) and cell temperature, which helps predict the overpotential changes to the cell electrodes and thermodynamics.We use the TTiS model to identify the dominant fade mechanisms in 3 sets of experimental cycling and temperature data for the: i) normal operating window (2.5V – 4.2V), ii) 5 initial cycles of over-discharge (1.5V – 4.2V) followed by normal operation until 20% capacity fade and iii) 5 cycles of periodic over-discharge every 20 cycles, until 20% capacity fade. Analysis on the effect of C-rate, ambient temperature and voltage window of operation will facilitate understanding the temperature behavior and overpotentials in a cell sandwich. Key considerations required in extending a model to simulate over-discharge will also be examined. References S.P. S. Badwal, S. S. Giddey, C. Munnings, A. I. Bhatt, and A. F. Hollenkamp, Frontiers in Chemistry, 2, 28 (2014).G. Pistoia. Lithium-Ion Batteries: Advances and Applications. First ed. Elsevier, Amsterdam (2014).R. Guo, L. Lu., M. Ouyang, X. Feng. Sci Rep 6, 30248 (2016).G.Zhang, X. Wei, S. Chen, J. Zhu, G. Han, and H. Dai. J. Power Sources, 521, 230990. (2022).C. Fear, D. Juarez-Robles, J. A. Jeevarajan, and P. P. Mukherjee, J. Electrochem. Soc., 165, A1639–A1647 (2018).D. Juarez-Robles, Purdue Univ. Ph.D. Thesis (2019).H. Maleki and J. N. Howard, J. Power Sources, 160, 1395–1402 (2006).H. Liu, Z. Wei, W. He, and J. Zhao, Energy Convers. Manag., 150, 304–330 (2017).A. Subramaniam, S. Kolluri, S. Santhanagopalan, and V. R. Subramanian, J. Electrochem. Soc., 167, 113506 (2020).A. Subramaniam, S. Kolluri, C. D. Parke, M. Pathak, S. Santhanagopalan, and V. R. Subramanian, J. Electrochem. Soc., 167, 013534 (2020).M. Doyle, T. F. Fuller, and J. Newman, J. Electrochem. Soc., 140, 1526 (1993)

Modeling Diurnal and Annual Ethylene Generation from Solar-Driven Electrochemical CO2 Reduction Devices

Integrated solar fuels devices for CO2 reduction (CO2R) are a promising technology class towards achieving net-negative carbon emissions. Designing integrated CO2R solar fuels devices requires careful co-design of electrochemical and photovoltaic components as well as consideration of the diurnal and seasonal effects of solar irradiance, temperature, and other meteorological factors expected for ‘on-sun’ deployment. Using a photovoltaic-electrochemical (PV-EC) platform, we developed a temperature and potential-dependent diurnal and annual model using experimental CO2R performance of Cu-based electrocatalysts, local meteorological data from the National Solar Radiation Database (NSRD), and modeled performance of commercial c-Si PVs. We simulated diurnal product outputs with and without the effects of ambient temperature to determine gaseous product temperature sensitivity. From these outputs, we observed seasonal variation in gaseous product generation, with up to two-fold increases in ethylene productivity between the Winter and Summer, analyzed the consequences of dynamic cloud coverage, and identified periods where device cooling/heating mechanisms could be implemented to maximize ethylene generation. Finally, we modeled the annual ethylene generation for a scaled 1 MW solar farm at three different locations (Beijing, CN; Sydney, AUS; Barstow, CA) to determine the consequences of local meteorological climates on PV-EC CO2R product output, recording a maximum ethylene output of 18.5 tonne/yr at Barstow. Overall, this model presents a critical tool for streamlining the translation of experimental solar-driven electrochemical research to real-world implementation.

Numerical study of bischofite precursor droplet evaporation and thermal decomposition for spray pyrolysis systems

Understanding the evaporation and decomposition process of bischofite precursor droplets in a pyrolysis furnace is the prerequisite for designing an efficient spray bischofite treatment facility. However, current research lacks guidance on this behavior. Here, it provided a new theoretical basis for understanding evaporation characteristics and decomposition behavior by introducing the Abramzon-Sirignano and kinetics models. In addition, the effects of ambient temperature and relative humidity on the evaporation characteristics of different precursors were analyzed. Meanwhile, the decomposition products and yield changes were studied in detail under different temperatures and times. The results show that the mass transfer coefficient and latent heat of vaporization have the most significant influence on droplet evaporation. To high recovery rate, the reaction temperature must be above 1125 °C. The current work can guide obtaining high magnesium oxide yield from waste bischofite in pyrolysis.

Cyclooxygenase-2 (COX-2)-dependent mechanisms mediate sleep responses to microbial and thermal stimuli

Prostaglandins (PGs) play a crucial role in sleep regulation, yet the broader physiological context that leads to the activation of the prostaglandin-mediated sleep-promoting system remains elusive. In this study, we explored sleep-inducing mechanisms potentially involving PGs, including microbial, immune and thermal stimuli as well as homeostatic sleep responses induced by short-term sleep deprivation using cyclooxygenase-2 knockout (COX-2 KO) mice and their wild-type littermates (WT). Systemic administration of 0.4 µg lipopolysaccharide (LPS) induced increased non-rapid-eye movement sleep (NREMS) and fever in WT animals, these effects were completely absent in COX-2 KO mice. This finding underscores the essential role of COX-2-dependent prostaglandins in mediating sleep and febrile responses to LPS. In contrast, the sleep and fever responses induced by tumor necrosis factor α, a proinflammatory cytokine which activates COX-2, were preserved in COX-2 KO animals, indicating that these effects are independent of COX-2-related signaling. Additionally, we examined the impact of ambient temperature on sleep. The sleep-promoting effects of moderate warm ambient temperature were suppressed in COX-2 KO animals, resulting in significantly reduced NREMS at ambient temperatures of 30 °C and 35 °C compared to WT mice. However, rapid-eye-movement sleep responses to moderately cold or warm temperatures did not differ between the two genotypes. Furthermore, 6 h of sleep deprivation induced rebound increases in sleep with no significant differences observed between COX-2 KO and WT mice. This suggests that while COX-2-derived prostaglandins are crucial for the somnogenic effects of increased ambient temperature, the homeostatic responses to sleep loss are COX-2-independent. Overall, the results highlight the critical role of COX-2-derived prostaglandins as mediators of the sleep-wake and thermoregulatory responses to various physiological challenges, including microbial, immune, and thermal stimuli. These findings emphasize the interconnected regulation of body temperature and sleep, with peripheral mechanisms emerging as key players in these integrative processes.

Machine Learning optimization of a zero energy building (ZEB) by waste heat recovery in a co-generation system

Waste heat recovery is known as one of the newest methods to increase the energy and exergy efficiencies of thermal systems. The concept has been also developed in co-generation systems where productions of electricity, cooling and heating are considered, simultaneously. This study investigates tri-generation system with a co-generation ammonia-water cycle (AWC) and an organic Rankine cycle (ORC) to supply cooling, heating, and power, simultaneously. As novelty, six different working fluids of Ammonia, R124, R134a, R152a, R245fa and R290 were investigated, as six scenarios for ORC. As result, the R124 was found as the best one and the next investigations were followed just with this fluid. Minimizing total cost and maximizing exergy efficiency at the same time are the main aim of this paper. Design Expert software was used to find out about this optimum point. Four cities in Australia were selected and the effect of annual ambient temperatures of them were studied on the outputs of the system, using TRNSYS software. Also, the optimum values of the effective parameters, including the isentropic efficiencies of pumps, compressor, and turbines, heat source temperature, ammonia concentration, utmost pressures of ORC and AWC, were obtained and reported by means of TOPSIS. As results, the monthly generations in electricity, heating and cooling were estimated. It was revealed that the lower ambient temperature, the higher electricity generation, according to the thermodynamic cycle of the proposed co-generation system. Finally, the results showed that application of the suggested co-generation system can cover the electricity demand of 294 apartments, heating for 208 apartments, and cooling load for 18,999 apartments.

Low-cost preparation of multifunctional anti-fog coating with double-layer composite structure

This study presents the development of a two-layer superhydrophilic nanocoating (superhydrophilic SFPn coating) for transparent materials to mitigate the negative effects of ambient temperature on their performance. The proposed coating combines excellent superhydrophilic and anti-reflective features and has high mechanical stability due to the anchoring structure formed by the underlying layer with spherical silica sols and the bonding effect of fibrous silica sols. The influence of the average particle size of the fibrous silica sol on the morphology and properties of the coating was investigated. The results show that the superhydrophilic SFPn coating prepared with a fibrous silica sol with an average particle size of 2.456 nm achieves a significant light transmission of 98.93% at 454 nm, which is an 8% improvement compared to bare glass. The proposed coating achieved a water contact angle of 6.7°. Extensive testing has demonstrated the effectiveness of the coating in terms of anti-fogging, adhesion and self-cleaning. These findings highlight the potential of the proposed coating to improve the reliability and performance of transparent materials and offer promising solutions for the application of transparent materials in a variety of fields such as optical instruments, agriculture, and automotive.

Heat transfer processes in 'Shine Muscat' grapevine leaves in solar greenhouses under different irrigation treatments

The use of solar greenhouses in China is increasing because they permit environmental conditions to be controlled. Studies of the heat transfer processes in the leaves of plants cultivated within solar greenhouses are needed. Here, we studied heat transfer processes in 'Shine Muscat' grapevine leaves under moderate deficit irrigation (MDI), severe deficit irrigation (SDI), and full irrigation (FI) treatments under varying weather conditions. The stomatal conductance, leaf temperature, and transpiration rate of both shade and sun grapevine leaves were measured, and the effects of ambient temperature and relative humidity on these variables were determined. A thermal physics model of the leaves was established to explore the heat dissipation process. On sunny days, the transpiration heat transfer of sun leaves in the MDI, SDI, and FI treatments was 2.62 MJ m−2·day−1, 2.44 MJ m−2·day−1, and 3.86 MJ m−2·day−1and 0.818 MJ m−2·day−1, 0.782 MJ m−2·day−1, and 1.185 MJ m−2·day−1 on rainy days, respectively. There was a significant difference in transpiration heat transfer under fully irrigated and deficit irrigation conditions under different weather conditions. Furthermore, transpiration heat transfer accounted for 41.49 % and 25.03 % of the total heat transfer of sun leaves in the FI treatment and 33.94 % and 29.43 % of the total heat transfer of shade leaves on rainy days, respectively, indicating that relative humidity plays a key role in determining transpiration heat transfer and leaf temperature and that its effect was greater on sun leaves than on shade leaves.