Increase In Ambient Temperature Research Articles

Association of Psychiatric Emergency Visits and Warm Ambient Temperature during Pregnancy: A Time-Stratified Case-Crossover Study.

Acute exposure to high ambient temperature and heat waves during the warm season has been linked with psychiatric disorders. Emerging research has shown that pregnant people, due to physiological and psychological changes, may be more sensitive to extreme heat, and acute exposure has been linked to increased risk of pregnancy complications; however, few studies have examined psychiatric complications. Our objective was to examine the association between acute exposure to warm ambient temperatures and emergency department (ED) visits for mental disorders during pregnancy. A time-stratified case-crossover design with conditional logistic regression was performed on psychiatric ED visits for pregnant patients in North Carolina, from May to September 2016 to 2019. Daily average ambient temperature was the main exposure and was linked to daily visits by maternal zip code of residence for prenatal mood and anxiety disorders (PMAD), severe mental illness (SMI), mental disorder of pregnancy (MDP), suicidal thoughts (SUIC), and any psychiatric disorder (Any). Effect modification by trimester, residential segregation, economic segregation, urbanicity, and availability of greenspace was also investigated. Each increase in same-day exposure to warm ambient temperature on case days was associated with an increase in incidence rate ratio (IRR) for any psychiatric disorder [IRR = 1.07; 95% confidence interval (CI): 1.01, 1.14] including anxiety (IRR = 1.14; 95% CI: 1.00, 1.30), bipolar disorder (IRR = 1.28; 95% CI: 0.98, 1.67), and suicidal thoughts (IRR = 1.28; 95% CI: 1.00, 1.65) compared to control days. In general, the associations were strongest for warm season temperatures on the same day of exposure or for temperatures averaged over the 3 or 6 d preceding the ED visit. The greatest risk of an incident ED admission for PMAD (RR = 1.20; 95% CI: 1.04, 1.39), particularly for anxiety (RR = 1.30; 95% CI: 1.07, 1.59), and any psychiatric disorder (RR = 1.17; 95% CI: 1.07, 1.28) occurred following cumulative exposure to hot temperatures the week before admission. Higher psychiatric burden from temperature was observed in urban areas and on extreme heat days. For this pregnant population in the southeastern United States, short-term exposure to high ambient temperatures during the warm season was associated with a greater risk of ED visits for an array of psychiatric disorders. Findings show that climate-related increases in ambient temperature may contribute to psychiatric morbidity in pregnant people. https://doi.org/10.1289/EHP13293.

Microbial transformation mechanisms of particulate organic carbon to mineral-associated organic carbon at the chemical molecular level: Highlighting the effects of ambient temperature and soil moisture

Soil dissolved organic matter (DOM), an important component of active soil organic carbon (C), plays a crucial role in controlling C transformation. However, the role of DOM in mediating the conversion of particulate organic C (POC) into mineral-associated organic C (MAOC) at the molecular level remains unclear. In this study, the microbial conversion of POC to MAOC at the molecular level was investigated at different ambient temperatures and soil moisture levels. An increase in ambient temperature led to the conversion of POC to labile C, whereas MAOC increased with soil moisture. CHO, CHNO, and CHOS increased with soil moisture and temperature. The highest temperature (35 °C) promoted conversion of lignin/cram (carboxyl-rich alicyclic molecules)-like molecules into aromatic components with the highest intragroup transformation of DOM (74%). The highest soil moisture (60%) favoured the conversion of refractory substances into aliphatic/peptide and lipid components with the highest intergroup transformation (28%). Compared to fungi, bacteria were the main driving force for DOM transformation. Therefore, changes in ambient temperature and soil moisture control the microbial formation and transformation of different C fractions (i.e. POC and MAOC) via DOM differently at the molecular level.

Study on performance of direct-expansion heat pump water heater integrated uninsulated micro-channel PV/T solar collector

In this paper, a direct-expansion heat pump water heater system integrated uninsulated micro-channel PV/T solar collector (UMC-PVT-SC) is proposed. This system can realize storage for both thermal energy and electricity, ensuring the supply of domestic hot water. The theoretical models of micro-channel PV/T solar collector, hot water storage tank, compressor and electronic expansion valve are established to investigate the performance of the micro-channel PV/T heat pump water heater system. R134a is used as refrigerant. The system performance is numerically simulated using MATLAB for different solar radiation intensity, ambient temperature and wind speed. The results show that solar radiation intensity has the largest influence on the system performance, followed by ambient temperature and wind speed. The coefficient of performance of the heat pump (COPHP) and the overall coefficient of performance (COPpvt) of the integrated system increase while the required operating time reduces, as solar radiation intensity and ambient temperature increase. The uninsulated micro-channel PV/T solar collector (evaporator) can absorb thermal energy from both ambient air and solar radiation and therefore achieve high COPHP, electric efficiency and COPpvt. Even under cold weather conditions, the proposed solar collector and heat pump heater demonstrate high efficiencies, heating and power generation capacities. When ambient temperature is −18.6 °C and solar irradiance is 322 W/m2, the collector efficiency and electric efficiency of UMC-PVT-SC are still at 0.718 and 0.244, respectively, and the COPHP and COPpvt of the heat pump heater are 3.5, 5.63, respectively. The present work is of potential value for delivering net zero.

Effect of increasing ambient temperature on physiological changes, oxidative stress, nitric oxide, total antioxidant power, and mitochondrial activity of Nile tilapia (Oreochromis niloticus Linn.)

The objective of this study was to investigate the effect of high ambient temperature on physiological changes of live Nile tilapia (Oreochromis niloticus Linn.) and biochemical parameters in Nile tilapia blood cells. Live Nile tilapia and Nile tilapia blood cells were maintained at temperature ranges from 24 to 34 °C and 24–38 °C, respectively. Then, physiological parameters (body temperature, body color score, pulse rate, ventilation rate, oxygen saturation) of the live Nile tilapia and biochemical parameters (total antioxidant power, hydrogen peroxide, malondialdehyde, nitric oxide, and mitochondrial activity) of the Nile tilapia blood cells were measured for every 2 °C increase. It was found that when the ambient temperature increases, body temperature of live Nile tilapia continually increased. Total antioxidant power and hydrogen peroxide, pulse rate, body color score, malondialdehyde, ventilation rate and mitochondrial activity commenced to increase at 26, 28, 30, 32, 34 °C (P < 0.05), respectively. Blood oxygen saturation decreased at 32 °C (P < 0.05). The response of nitric oxide of Nile tilapia blood cells responded to increased temperature in two phases. In the first phase, nitric oxide decreased at 28–32 °C (P < 0.05), then increased and decreased again at a temperature of 38 °C (P < 0.05). These phenomena indicated that when the live Nile tilapias and the Nile tilapia blood cells were exposed to high ambient temperature, they were under heat stress and oxidative stress. In addition, physiological responses in the live Nile tilapia and biochemical changes in their blood cells when exposed to high ambient temperature occurred in a consistent manner when the temperature continually increased.

Anthropogenic heat from buildings in Los Angeles County: A simulation framework and assessment

Anthropogenic heat (AH), i.e., waste heat from buildings to the ambient environment, increases urban air temperature and contributes to the urban heat island effect, which leads to more air-conditioning energy use and higher associated waste heat during summer, forming a positive feedback loop. This study used a bottom-up simulation approach to develop a dataset of the annual hourly AH profiles for 1.7 million buildings in Los Angeles (LA) County for the year 2018 aggregated at three spatial resolutions: 450 m, 12 km, and the census tract. Building AH exhibits strong seasonal and diurnal patterns, as well as large spatial variations across the urban areas. Building AH peaks in May and reaches a maximum of 878 W/m2 within one of several AH hotspots in the region. Among the three major AH components (surface convection, heat rejection from HVAC systems, and zonal air exchange), the surface convection component is the largest, accounting for 78% of the total building AH across LA County. Higher AH is attributed to large building density, a high percentage of industrial buildings, and older building stock. While AH peaks during the day, the resulting ambient temperature increases are much larger during the night. During the July 2018 heatwave in LA County, building AH (excluding the surface component) leads to a daily maximum ambient temperature increase of up to 0.6 °C and a daily minimum ambient temperature increase of up to 2.9 °C. It is recommended that reducing summer building AH should be considered by policy makers in developing mitigation measures for cities to transition to clean energy while improving heat resilience.

Heat waves and pediatric emergency department febrile-related visits

BackgroundIn recent decades, we have observed an increase in ambient temperature due to the effects of climate change. ObjectiveIn this study, we aimed to determine whether there is a correlation between environmental temperature and urgent consultations of pediatric patients related to febrile processes. Research design and methodWe conducted an observational, retrospective, single-center study in the pediatric ED of the Hospital Universitario La Paz, Madrid, Spain. We analyzed visits to the ED for febrile processes during the last heat waves in Madrid. ResultsBetween 2018 and 2022, seven heat waves were recorded in Madrid. A total of 3967 patients with fever as the main reason for consultation attended during this period. In two of the seven heat waves analyzed, febrile-related visits were higher during the heat alert. The first occurred between 6/11/2022 and 6/16/2022, with 345 febrile-related ED visits, 25.4% more than the previous days and 19.7% more than the following days. During this heat wave, we observed a positive correlation between the maximum temperature recorded and the number of visits to the ED for febrile processes (Rs=0.552; p = 0.018). During the heat wave between 09/07/2022 and 17/07/2022, 362 febrile-related ED visits were 3.1% more than the previous days and 24.9% more than the following days. ConclusionDuring recent heat waves in our city, we registered an increase in febrile-related visits compared with non-heat alert periods.

Optical, electrical, and thermal performance of low-concentrating photovoltaic/thermal system using microencapsulated phase change material suspension as a coolant

Concentrated photovoltaic/thermal (C-PV/T) systems exhibit superior output compared to common PV/T collectors. To address potential issues caused by excessive concentration of conventional parabolic concentrators and enhance the electro-thermal co-generation capability, this work proposes a low-concentrating PV/T (LC-PV/T) system that integrates two improved concentrator designs and a coolant of microencapsulated phase change material suspension (MPCMS). A numerical model is established to investigate the effects of working conditions and meteorological conditions on the optical, electrical and thermal performances. The results indicate that the improved concentrator designs effectively prevent over-concentration of sunlight while maintaining a comparable concentration ratio (CR). The electrical output increases with an increase in mass fraction, inlet mass flow rate and solar irradiance, but decreases with an increase in ambient temperature and inlet temperature. Conversely, thermal output increases with an increase in all of these parameters except for the inlet temperature. This system can achieve 17 % electrical efficiency and 72 % thermal efficiency due to the high-efficiency solar cells, optimized concentrator design, and unique MPCMS coolant. The system can produce a maximum electrical power of 4.76 kW/m2 and a maximum thermal power of 19.53 kW/m2. Throughout the day, total electrical and thermal energies are approximately 4.1 kWh and 58.8 MJ.

Comparative Analysis of Current-Voltage Characteristics of Photovoltaic (PV) Systems in Selected Climatic Regions in Cross River State, Nigeria

This study investigated the effect of solar radiation’s intensity and ambient temperature on the current-voltage (I-V) characteristics of monocrystalline and polycrystalline photovoltaic (PV) systems in the generation of electricity in Calabar and Okuku, Cross River State, Nigeria. Appropriate measuring devices were employed to record daily readings of these parameters at the study locations, from July to August 2022. The data were collected and results graphically analyzed and calculated. The results indicate that current (Isc), voltage (Voc) as well as the maximum power (Pmax) of both module types increased positively with increase in solar radiation and ambient temperature. Results from collected and computed data also show average daily readings across the locations for solar radiation ranging between 271Wm-2 and 409Wm-2 and ambient temperature between 320C and 370C. The calculated Pmax ranges between 49W and 63W from the 130W solar modules used for the investigation. Another notable result is that the polycrystalline module exhibits higher Pmax than the monocrystalline module in both locations. In spite of the low solar radiation and ambient temperature obtained during this study period, which is considered the worst climatic period of the year (July and August), it is desirable and recommendable to employ solar modules as an alternative power generation in Calabar and Okuku, Cross River State, Nigeria.

Energy and exergy-based degree-hours in estimation of heat requirements for heating and cooling purposes

This study presents an innovative exergy-based methodology to revolutionize the assessment of heating and cooling energy utilization, transcending the limitations of traditional heating and cooling degree-hours (HDH and CDH) analyses. The study’s distinctiveness stems from its investigation into variations in HDH and CDH concerning critical parameters such as ambient temperature, solar-air temperature, solar absorptivity, surface emissivity, and total heat transfer coefficient. This fosters a profound comprehension of the thermodynamic performance of building heating and cooling systems, empowering decision-makers with the insights needed to optimize energy utilization effectively. As demonstrated through a case study conducted in Antalya, Turkey, this study uncovers significant findings. A mere 1 °C increase in ambient temperature results in an average 14 % surge in heating demand and an average 17 % decline in cooling demand, leading to a substantial 1000°-h discrepancy between heating and cooling requirements. Furthermore, we underscore the sensitivity of energy demand to temperature fluctuations, the substantial impact of design temperature on energy consumption, the notable influence of solar effects on environmental conditions, and the potential for optimization in parameters such as solar absorptivity, surface emissivity, and total heat transfer coefficient. These insights underscore the significance of exergy-based systems, offering heightened energy efficiency, swift adaptability to temperature changes, integration of renewable energy sources, and intelligent control features that contribute to sustainability and energy savings.

Climate Change and Stroke: A Topical Narrative Review.

The impacts of accumulating atmospheric greenhouse gases on the earth's climate are now well established. As a result, there have been increases in ambient temperatures and resultant higher frequency and duration of temperature extremes and other extreme weather events, which have been linked to a wide range of adverse health outcomes. This topical narrative review provides a summary of published evidence on the links between climate change and stroke. There is consistent evidence of associations between stroke incidence and mortality and increasing ambient temperature and air pollution. Associations have also been shown for changes in barometric pressure, wildfires, and desert dust and sandstorms, but current evidence is limited. Flooding and other extreme weather events appear to primarily cause service disruption, but more direct links to stroke may emerge. Synergies between dietary changes that reduce stroke risk and may also reduce carbon footprint are being explored. We also discuss the impact on vulnerable populations, proposed pathophysiologic mechanisms, mitigation strategies, and current research priorities. In conclusion, climate change increasingly impacts the stroke community, warranting elevated attention.

Impact of ambient temperature on the filter polychromators performance and accuracy of thomson scattering diagnostics

Thomson scattering is one of the most important diagnostic methods for measuring plasma electron temperature (Te) and electron density (ne). In the diagnostic system, the polychromator is often used to analyze the spectral broadening and intensity of the detected scattered light. The performance of the avalanche photodiode (APD) used in the polychromator is greatly affected by the ambient temperature. The change of ambient temperature will seriously affect the accuracy of Thomson scattering diagnosis. Through experimental analysis, when the ambient temperature increases, the gain of APD will be significantly reduced, resulting in a significant deviation in electron density measurement. Taking the system response at an ambient temperature of 24.1 °C as reference, the deviation of electron density measurement varies from 43% to −16%, with the ambient temperature from 16.6 °C to 29.9 °C. However, the change of ambient temperature has little impact on the measurement of electron temperature. Detailed test of the polychromator shows that the estimated deviation of the electron temperature is within 3%. Due to the change of ambient temperature, the response of the detectors in each channel of the polychromator is inconsistent, which will cause random errors. The influence on electronic temperature calculation is analyzed by numerical simulation.

Exposure to ambient temperature and heat index in relation to DNA methylation age: A population-based study in Taiwan

BackgroundClimate change caused an increase in ambient temperature in the past decades. Exposure to high ambient temperature could result in biological aging, but relevant studies in a warm environment were lacking. We aimed to study the exposure effects of ambient temperature and heat index (HI) in relation to age acceleration in Taiwan, a subtropical island in Asia. MethodsThe study included 2,084 participants from Taiwan Biobank. Daily temperature and relative humidity data were collected from weather monitoring stations. Individual residential exposure was estimated by ordinary kriging. Moving averages of ambient temperature and HI from 1 to 180 days prior to enrollment were calculated to estimate the exposure effects in multiple time periods. Age acceleration was defined as the difference between DNA methylation age and chronological age. DNA methylation age was calculated by the Horvath’s, Hannum’s, Weidner’s, ELOVL2, FHL2, phenotypic (Pheno), Skin & blood, and GrimAge2 (Grim2) DNA methylation age algorithms. Multivariable linear regression models, generalized additive models (GAMs), and distributed lag non-linear models (DLNMs) were conducted to estimate the effects of ambient temperature and HI exposures in relation to age acceleration. ResultsExposure to high ambient temperature and HI were associated with increased age acceleration, and the associations were stronger in prolonged exposure. The heat stress days with maximum HI in caution (80-90°F), extreme caution (90-103°F), danger (103-124°F), and extreme danger (>124°F) were also associated with increased age acceleration, especially in the extreme danger days. Each extreme danger day was associated with 571.38 (95 % CI: 42.63–1100.13), 528.02 (95 % CI: 36.16–1019.87), 43.9 (95 % CI: 0.28–87.52), 16.82 (95 % CI: 2.36–31.28) and 15.52 (95 % CI: 2.17–28.88) days increase in the Horvath’s, Hannum’s, Weidner’s, Pheno, and Skin & blood age acceleration, respectively. ConclusionHigh ambient temperature and HI may accelerate biological aging.

Exploring Climate Change Adaptation Practices and Agricultural Livelihoods among Rice Farmers of the Brahmaputra Valley in Northeast India.

Global climate change has seriously threatened agriculture and connected sectors, especially in developing countries like India. The Brahmaputra Valley in Assam, Northeast India, is vulnerable to climate change due to its agrarian economy, fragile geo-ecological setting, recurrent floods and droughts, and poor socioeconomic conditions of the farmers. The climate-induced hindrances faced by the rice farming community of this region and the local adaptation practices they employ have not been adequately studied. Therefore, we carried out a survey among 635 rice farmers across four agro-climatic zones of Assam, namely the Upper Brahmaputra Valley Zone, North Bank Plain Zone, Central Brahmaputra Valley Zone, and Lower Brahmaputra Valley Zone, to understand how they perceive and respond to climatic changes. The survey revealed that all the respondents have perceived an increase in ambient temperature, and 65% of the respondents have perceived a slight change in rainfall characteristics over the years. Most farmers reported adjusting the existing farming practices and livelihood choices to adapt to the changing climate. Farming adjustments were made mainly in terms of field preparation and management of water, rice variety, nutrients, and pests. Environmental variables like rainfall, flood, drought, and pest level, and socioeconomic variables like family size, education, farming experience, training, digital media exposure, and land area were found to influence farmers' adaptation choices. The findings imply that policies to strengthen flood, drought, pest management, education, land-use planning, agricultural training, and digital media applications in agriculture are needed for effective climate change adaptation in this region.

Change of Dielectric Constant of Highly Doped-Silica Glass Used in Optical Fibers with Frequency and Temperature Under the Effect of Polarization

In this study, the variation of the dielectric constant, i.e. relative permittivity of highly doped-silica glass used in optical fibers with frequency and temperature under the effect of polarization has been investigated. In this context, simulations of the relationship between the dielectric constant and both frequency and temperature have been carried out in the Matlab environment. According to simulation and theoretical analysis, it has been concluded that the dielectric constant of highly doped-silica glass tends to increase with the increase of ambient temperature. On the other hand, as the frequency of the source increases linearly, the dielectric constant decreases. Hence, the variations of highly doped-silica glass with temperature and frequency have been found to be 2.884 × 10-5 (°K)-1 and – 7.50 × 10-15 (Hz)-1, respectively. Moreover, in response to the change in frequency between 1011 Hz and 1012 Hz, the dielectric constant has taken values between 2.085 and 2.070. Additionally, for dielectric constant variations in 2.070 – 2.085 range, values of the relative change in polarization have been obtained in the range of 9.4695 × 10-12 F/m – 9.6023 × 10-12 F/m.

Techno-economic assessment of the modified Allam cycle configurations with multi-stage pump/compressor for efficient operation in hot regions

The Allam cycle is renowned for its zero-carbon power generation and high efficiency. However, it faces challenges in hot regions where there is no available cold source for carbon dioxide liquefaction, leading to deterioration in its performance. In this study, a multi-stage pump/compressor is introduced, aiming to enhance the net electric efficiency of the conventional Allam cycle. Various potential enhancement methods are explored and analyzed through comprehensive thermodynamic and economic analyses. Among the configurations under consideration, the Allam cycle combined with two-stage pump/compressor and bypass compressor exhibits the best performance, achieving a 6.71 % increase in the efficiency of the conventional cycle. For the conventional Allam cycle, the efficiency decreases by 0.42 % for every 1 ℃ increase in ambient temperature, however, it is 0.17 % for the Allam-MPC cycle, which indicates it is less responsive to changes in ambient temperature. Moreover, the economic performance of the proposed cycle is better than that of the conventional cycle, which has higher revenue and lower levelized cost of electricity. The capital costs of the modified equipment represent around 1.43 % of the total capital costs of the conventional Allam cycle, and the investment-increment payback period is less than 0.5 years when the ambient temperature exceeds 30 ℃. Sensitivity analyses suggest that the proposed cycle will be more economically viable in hot regions with lower natural gas prices and higher electricity prices. Overall, this study provides a promising approach to improving the performance of Allam cycle in hot regions and offering valuable references for its practical implementation.

Study on improving flavor and antioxidant capacity of 3D printed spinach gel system by combining modified atmosphere and ambient temperature

This study aimed to control printing ambient temperature and oxygen content collaboratively to achieve synchronous improvement of the sensory and nutritional quality of printed products. In this study, spinach juice and potato snowflake powder were used as raw materials to prepare printing materials. The results showed that the printing material with a 20% addition of potato snowflake powder had the best printing performance. Enhancing the flavor of the printed products in the printing process by increasing the printing ambient temperature, the printed product with better flavor quality was obtained at 40 °C. However, the increase in ambient temperature had adverse effects on the color and antioxidant capacity of the printed product, the ΔE value of the printed product at 40 °C was 6.18 ± 0.64. Based on this ambient temperature, reducing the oxygen content in the printing environment inhibited the adverse effects of rising temperature on the color and antioxidant capacity of printed products. When the oxygen content was below 1%, the printed product maintained the color and antioxidant capacity before printing, the ΔE value of the printed product was only 0.95 ± 0.09, and there was no significant difference in antioxidant properties (total chlorophyll content, total carotenoid content, total phenolic content, free radical scavenging activity). Therefore, while successfully improving the flavor of the product, this study achieved the maintenance of color, antioxidant capacity, and other qualities, which is an effective exploration of using 3D printing technology to produce high-quality food.

Temperature dependence of atomic‑oxygen irradiation mechanism of hydrogenated diamond-like carbon film

Hydrogenated diamond-like carbon (H-DLC) films are effective lubricants for aerospace moving parts, but the service of H-DLC is severely threatened by atomic oxygen (AO) in low Earth orbit (LEO). The interaction between AO and H-DLC strongly depends on ambient temperature; however, the interactive mechanism has not been fully understood. In this study, we report different temperature dependences of AO irradiation behavior on H-DLC film. Under the AO irradiation with low energy, the increase in ambient temperature can only increase the surfacial oxidation; while, the effect of temperature under high AO irradiation energy is more significant, resulting in the transition from the surficial oxidation to continuous carbon removal. Subsequent analysis of the AO trajectories shows that the different repulsion mechanisms of the H-DLC surface against high and low energy AO result in the different temperature dependence. For AO incident with low energy, the incident AO cannot touch the H-DLC surface anymore due to the repulsion of the surfacial oxygen in the later irradiation stage. Nevertheless, high energy AO could overcome the repulsion of oxidized surface to contact the H-DLC surface, the increase in temperature can continuously promote the AO irradiation on the H-DLC surface.

Impact of Ambient Temperature and Humidity on the Performance of Vapour Compression Air Conditioning System - Experimental and Numerical Investigation

Due to global warming, population growth, and urbanisation, demands for space cooling in buildings have significantly increased. Mechanical vapour compression cooling technology is relatively mature, well-understood and most commonly used globally. However, they suffer from high energy consumption and adverse environmental impact due to the refrigerants used. As ambient temperature and humidity have significant effects on the performance of vapour compression systems, this paper experimentally and numerically investigates their impact on the performance of vapour compression air conditioning system in terms of power consumption and cooling capacity. It was concluded that at ambient humidity of 55%, as the ambient temperature increases from 22 °C to 40 °C, the compressor temperature has increased from 46 °C to 59 °C which increased its power consumption from 751.2 to 935.52 Watts, giving an increase of 10.24 Watts for every one degree of ambient temperature increase. Also, as ambient humidity in-creased from 32% to 88%, the power consumption increased from 739.2 Watts to 853.2 Watts, an increase of 114 Watts. A validated CFD (Computational Fluid Dynamics) model was developed and predicted a loss in the enthalpy change from 11.7kJ/kg.d.a to 3.6kJ/kg.d.a. due to ambient temperature increasing from 22 °C to 40 °C and a loss of enthalpy change from 12.857kJ/kg.d.a to 5.524kJ/kg.d.a. due to increasing the ambient air humidity from 32% to 88%. This work high-lighted the impacts of ambient conditions on the performance of vapour compression cooling system in terms of increased power consumption and loss of cooling capacity.

Experimental Investigation of Thermal Effect on the Frictional Characteristics of HCC Friction Clutch Material

Increasing temperature due to frictional heat from sliding between contacting surfaces leads to increased wear and friction. Therefore, the researchers continue investigations to find the most suitable friction materials with good mechanical and thermal properties for frictional facings of clutch performance under this condition. In this research paper, the behavior and performance of the friction material HCC was studied under different normal load conditions (125, 175, 225, and 275 N) and different working environment temperatures (300 K and 390 K), where the rotation speed was 300 rpm. The results of the coefficient of friction and friction forces variation under different working conditions were analyzed and discussed in detail. XTM 500 tribometer test rig was used to perform the required tests, and the samples were made of the HCC friction material. The obtained results proved that the ambient temperature of the friction system has a significant negative effect on both the coefficient of friction and the force of friction. So, when the friction system's ambient temperature increases, the magnitude of the friction coefficient will decrease, and, thus, the transmitted torque will reduce too.

Climate-adaptive resilience in district buildings and cross-regional energy sharing in Guangzhou-Shenzhen-Hong Kong Greater Bay Area

Climate change imposes challenges on Sustainable Develop Goals (SDGs) with uncertainty in the energy supply, energy consumption, climate-adaptive design and operation, renovation and retrofit on traditional energy systems. However, academic studies focus on district energy system sizing, operation and energy analysis under typical year, without considering future climate change due to the lack of updated meteorological database. In this study, models are developed to predict meteorological parameters in Greater Bay Area. Building physical models are developed in TRNSYS 18 platform with power-to-cooling/heating conversions and thermal/electrical energy storages to quantitatively analyse the impact of climate change on cooling/heating/electric loads, rated capacity resizing and onsite renewable energy supply. Considering the differences in building intensity, types, available spatiotemporal spaces in the Greater Bay Area, spatiotemporal energy sharing networks with E-mobility in cross-boundary Guangdong-Hong Kong-Macao are developed for cross-regional renewable self-consumption and stablising local microgrid power/voltage. Results indicate that, both solar radiation and ambient temperature increase under the future climate change, while building services systems designed in the typical year fail to cover cooling demands due to future climate change. Immediate response and sufficient reaction to climate change with climate-adaptive design require gradual increase on rated capacities of chillers, together with the increase in total electricity consumptions (i.e., increased by 34.3%, 29.9%, 14.2% and 20.5% for residential buildings, hotel, office, and commercial buildings from typical year to the year 2100). Technical strategies for future climate change adaption include complementary solar-wind energy integration, E-mobility based cross-regional energy sharing, renewable-to-EV charging and EV discharging for grid support under the Vehicle-to-Grid (V2G) mode. The V2G mode is economically beneficial with overwhelming superiority in grid import cost saving than battery degradation cost. This study can contribute to future climate change prediction, climate-adaptive designs, operations and controls, and energy resilience improvement.