Daily Heat Research Articles

The consequences of heatwaves for the reproductive success and physiology of the wingless sub-Antarctic fly Anatalanta aptera

Sub-lethal effects of warming temperatures are an important, yet sometimes overlooked impact of climate change that may threaten the long-term survival of numerous species. This, like many other effects of climate change, is especially concerning for cold-adapted ectotherms living in rapidly warming polar regions. This study examines the effects of warmer temperatures on cold-adapted Diptera, using the long-lived sub-Antarctic sphaerocerid fly, Anatalanta aptera, as a focal species. We conducted two experiments to assess heat stress in adult flies, one varying the intensity of the heat stress (daily heating from 4 °C to 8 °C, 20 °C, or 24 °C) and one varying the frequency of heat stress exposure (heating from 4 °C to 12 °C every one, two, or three days) and examined consequences for reproductive success and metabolic responses. We found that more heat stress reduced reproductive output, but not timing of reproduction. Surprisingly, individuals sampled at different times during heat stress exposure were undifferentiable when all metabolite concentrations were analysed with redundancy analysis, however some individual metabolites did exhibit significant differences. Overall, our findings suggest that warmer temperatures in the sub-Antarctic may put this species at greater risk, especially when combined with other concurrent threats from biological invasions.

Infrared Thermography Inspection of Stay Cables

The injection of petroleum waxes into bridge stay cables is a proven method for protection against corrosion, primarily due to their sealing properties, adhesion to strands, and thermal stability. However, with a liquefaction point below 70°C, exceptional ambient conditions can lead to partial liquefaction of the injected waxes, especially for cables with a dark sheath, resulting in leaks and extrusions. Sections of stay cables may lose their corrosion protection without visible signs from the outside. This study explores the use of infrared thermography for identifying and mapping areas lacking wax. It involves acquiring high-resolution infrared thermal images of the stay cables and studying temperature variations. Since wax has a higher thermal inertia than air, a thermal gradient is expected between areas with wax and those without after the daily heating cycle. This paper presents a campaign conducted on a cable-stayed bridge in France. During this campaign, temporary instrumentation was deployed to identify the optimal intervention window. Multiple sessions of acquisitions using a high-precision thermal camera were then performed. The acquired images were subsequently rectified and assembled to create uniform and comprehensive panoramas of the stay cables. The results obtained for several characteristic cables are presented and discussed in this paper.

Daily heat and mortality among people experiencing homelessness in 2 urban US counties, 2015-2022.

High and low daily ambient temperatures are associated with higher mortality in the general population. People experiencing homelessness (PEH) are thought to be particularly vulnerable, but there is almost no direct evidence available. We examined the temperature-mortality association among PEH in 2 populous, urban counties in hot-climate regions of the United States, focusing on heat effects. Study setting was Los Angeles County, CA, and Clark County, NV, which encompass the cities of Los Angeles and Las Vegas, respectively. Outcomes were 2015-2022 deaths among decedents categorized as homeless in county administrative records. We used quasi-Poisson distributed lag nonlinear models to estimate the association of mortality with daily temperatures and with 7-day lagged temperatures, adjusting for day of week, seasonality, and long-term trends. We estimated the minimum mortality temperature and fraction of mortality attributable to temperatures above and below minimum mortality temperature. The association between daily temperature and PEH mortality was skewed towards greater risk at higher temperatures, especially in Clark County. Temperature-attributable mortality equaled 50.1% of deaths in Clark County (95% CI, 29.0-62.8) and 7.0% in Los Angeles County (95% CI, 1.4-12.1). In both counties, most temperature-attributable deaths were attributable to heat rather than cold. In these hot-climate urban counties, our estimates of heat-attributable mortality among PEH were orders of magnitude greater than those reported in prior research on the general population. These results indicate that temperature vulnerability, particularly heat vulnerability, requires stronger public health and policy responses. This article is part of a Special Collection on Environmental Epidemiology.

Impact of thermal manipulation during embryogenesis on thermotolerance and semen quality of Mandarah roosters exposed to heat stress.

The management of incubation conditions impacts embryonic development, hatchability, and post-hatch performance. This study aimed to examine the effects of thermal manipulation (TM) during embryonic development on roosters' thermotolerance, antioxidant activity, immunity, and semen quality under heat-stress conditions. 1200 fertile eggs were distributed evenly between two groups, each containing three replicates (200 eggs/replicate). The first group (G1) was held in the commercial setter with a consistent temperature of 37.5°C and 55% relative humidity (RH) through the 18-day incubation period, acting as a control, while the second group (G2) experienced these conditions until only the 11th day. The eggs were incubated at 39.5°C with 60% RH for 4 h each day from the 12th to the 18th day. From the 19th to 22nd incubation days, both groups maintained a consistent temperature of 37.2°C with a RH of 70%. Two hundred hatched male chicks per treatment group were moved into a closed-system house. All roosters were exposed to a 6-h daily heat challenge with a temperature of 35°C and a humidity of 70% between their 36th and 40th weeks of age. Roosters of G2 exposed to thermal challenge showed improvements (p ≤ 0.05) in multiple blood biochemical, antioxidant, and immunity markers, including total protein, globulin, aspartate aminotransferase, alanine aminotransferase, triiodothyronine, thyroxine, corticosterone, testosterone, total antioxidant capacity, malondialdehyde, immunoglobulin G, immunoglobulin M, and immunoglobulin A levels. Improved semen quality characteristics, including ejaculate volume, sperm concentration, motility, livability, and quality factor, as well as enhanced thermoregulation in post-hatch cocks, were also achieved (p ≤ 0.05). To boost antioxidant activity, immunity, thermotolerance, and semen parameters in roosters under heat-stress conditions, TM application during egg incubation, specifically at 12-18 days, is recommended.

Assessing the Applicability of Solar Thermal Technologies for Industrial Tea Drying

Most process heat being used for various industrial applications is supplied from fossil fuels. Coal, gas, and wood fuel are the most used heat resources which usually power steam boilers for production of heat used in a wide range of industrial processes. Since economic growth is largely linked to industrial production, it implies that, a shift towards use of clean energy technologies in industries is crucial to meet the rising demand of process heat while, cutting down carbon emissions to mitigate climate change. Solar thermal systems have over the past years shown potential as a practical alternative to fossil fuels for production of heat for several applications including, water and space heating, industrial process heating and electricity generation in thermal power plants. This study seeks to assess the feasibility of employing solar thermal technologies for drying purposes at Tingamira-Tanganda Tea estate in Zimbabwe. Systems advisor model (SAM) was applied to simulate performance of linear Fresnel (LF) and parabolic trough (PT) solar thermal technologies for industrial tea drying. Information on daily heat demand, required process temperatures and current heat sources was obtained to inform the design process of the proposed solar thermal systems. LF system exhibited better techno-economic performance. It requires a smaller collector area (360 m2) with a lower initial capital cost which is about 8% cheaper. Moreover, it produces higher annual energy at lower levelized cost of heat for solar multiples higher than 1. Carbon footprint of the factory would be reduced by about 114 tonnes CO2 annually. Sensible thermal energy storage technology can be considered for back up heat and heat recovery.

Rice Husk-Based Insulators: Manufacturing Process and Thermal Potential Assessment.

The development of bio-insultation materials has attracted increasing attention in building energy-saving fields. In tropical and hot-humid climates, building envelope insulation is important for an energy efficient and comfortable indoor environment. In this study, several experiments were carried out on a bio-insulation material, which was prepared by using rice husk as a raw material. Square rice husk-based insultation panels were developed, considering the ASTM C-177 dimensions, to perform thermal conductivity coefficient tests. The thermal conductivity coefficient obtained was 0.073 W/(m K), which is in the range of conventional thermal insulators. In a second phase of this study, two experimental enclosures (chambers) were constructed, one with rice husk-based insulation panels and the second one without this insulation. The measures of the temperatures and thermal flows through the chambers were obtained with an electronic module based on the ARDUINO platform. This module consisted of three DS18B20 temperature sensors and four Peltier plates. Daily temperature and heat flux data were collected for the two chambers during the dry season in Panama, specifically between April and May. In the experimental chamber that did not have rice husk panel insulation on the roof, a flow of up to 28.18 W/m2 was observed, while in the chamber that did have rice husk panels, the presence of a flow toward the interior was rarely observed. The rice husk-based insulation panels showed comparable performance with conventional insulators, as a sustainable solution that takes advantage of a local resource to improve thermal comfort and the reduction of the environmental impact.

Predicting daily heating energy consumption in residential buildings through integration of random forest model and meta-heuristic algorithms

This research utilizes a sophisticated hybrid model integrating the Random Forest algorithm with meta-heuristic optimization techniques to estimate heating energy consumption in residential buildings. The study addresses key variables including architectural characteristics, occupancy, and ambient temperature. The primary objective is to enhance the prediction accuracy of heating energy consumption using a novel approach combining Random Forest with various meta-heuristic algorithms. The study employs six combinations of the Random Forest algorithm and meta-heuristic optimizers. To mitigate overfitting, K-Fold cross-validation is implemented during model training. The model's performance is evaluated using five statistical indices: coefficient of determination (R2), Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), Relative Absolute Error (RAE), and Theil Inequality Coefficient (TIC). Results demonstrate the hybrid model's high predictive accuracy, with the Arithmetic Optimization Algorithm enhancing Random Forest's performance significantly. Notable statistical achievements include R2 = 0.977201, RMSE = 0.1179, MAE = 0.0573, RAE = 0.0930, and TIC = 0.0187. Additionally, the Ant Lion Optimizer shows excellent convergence, achieving a TIC value of 0.014986 after 101 iterations. The proposed hybrid model significantly outperforms traditional methods in predicting residential heating energy consumption. The integration of Random Forest with advanced meta-heuristic algorithms offers a robust framework for enhancing prediction accuracy in energy consumption modeling.

Amplification of the discrepancy between simplified and physics-based wet-bulb globe temperatures in a warmer climate

The Simplified Wet Bulb Globe Temperature (sWBGT) is widely used in heat stress assessments for climate-change studies, but its limitations have not been thoroughly explored. Building on recent critiques of sWBGT's use for current climate on global scale, this study examines sWBGT's biases using dynamically-downscaled sub-daily climate projections under multiple future emission scenarios. The analysis is aimed at understanding caveats in the application of sWBGT and the uncertainties in existing climate change analysis dependent on sWBGT. Results indicate sWBGT's biases are heavily influenced by local near-surface air temperature, with overestimation of heat stress in East Asia regions, particularly hot and humid areas, due to static assumptions of radiation and wind speed. This overestimation is amplified in warmer climates, leading to exaggerated projected heat stress increases in future. In contrast, underestimations are found for heat stress levels attributed to low wind speeds and strong radiations, such as over the Tibetan Plateau and certain extreme events. Additionally, sWBGT underestimates variability in extreme heatwave events compared to WBGT in both current and future climates, irrespective of overestimation in absolute heatwave intensities. This study emphasizes the limitations of sWBGT, especially in future warmer climates. Importance of sub-daily data for capturing daily maximum heat stress level and reflecting diurnal variations in different components is also discussed. In conclusion, we recommend using Liljegren's model (i.e., physics-based calculation) with high-resolution sub-daily climate data for more accurate outdoor heat stress assessments in climate change studies.

Development of a heat load index and risk map for grazing sheep

ABSTRACT A total of 5500 measurements of the respiration rate of 123 sheep with and without access to shade were obtained on 40 days in the summers (January–April) of 2022(Year 1) and 2023(Year 2). Models to predict respiration rate (breaths per minute (BPM)) based on temperature, humidity, wind speed, and solar radiation were calibrated to the Year 1 unshaded dataset (R2 =0.35, RMSE=39 BPM) and validated with the Year 2 unshaded dataset (R2=0.58, RMSE=40 BPM). Respiration rate increased 6 BPM for each 1°C increase in temperature. The shade treatment decreased respiration rate by 24 BPM and the shaded model for respiration rate had a validation RMSE of 47 BPM. The between sheep variability in respiration rate was described by a standard deviation of 18.9 BPM. The probability of open mouth and tongue out behaviours both increased linearly from 200 BPM. We constructed a daily Heat Load Index based on the cumulative respiration rate greater than 200 BPM. Climate data and sheep density information were used to construct a heat stress risk map for New Zealand from October 2018 to March 2022. Heat stress risk was concentrated in January–February and was primarily located on the east coast of the North Island.

Design and thermal performance evaluation of the thermal storage layer of a solar air collector with comprehensive consideration of six factors of phase-change materials

The heat storage layer of fully filled phase-change materials (PCM) does not melt completely, and this significantly reduces the heat storage capacity, heat-release time, output temperature difference, collection efficiency, heat peak migration ability, and PCM cost of PCM-based solar air collectors (SACs), thereby affecting the comprehensive heating requirements of building households. To solve these problems and obtain the optimal filling rate for PCM, four PCM filling schemes were designed with comprehensive consideration of the six factors of PCM. (Type I is a SAC filled with 0 % PCM, Type II is the upper portion filled with 25 % PCM, Type III is the upper portion filled with 50 % PCM, and Type IV is filled with 100 % PCM). Four models were constructed for comparative experiments. A comparative analysis of the thermal performance evaluation indices indicated that the phase-change heat storage process of the Type III thermal storage layer only uses 1.25 h to store 1.505 × 106 J of heat energy, thus indicating that Type III possesses a better heat storage capacity. The max-output temperature difference of the Type III collector decreased by 20.1 °C compared to that of Type I. This indicates that Type III collectors can balance the range of output temperatures and increase indoor thermal comfort. After the solar energy ceases, the continuous heat-release time of the Type III collector is 13.75 h, and the ratio of its heat-release time to non-solar time is 94.83 %. This indicates that Type III possesses a better heat release time. The daily average heat collection efficiency of Type III filled was 37.77 %, and this was only 6.72 % higher than that of Type IV, thus indicating that Type III exhibited better heat peak migration ability, PCM utilisation efficiency, and lower PCM cost.

Heat therapy preconditioning improves the skeletal muscle contractile and mitochondrial function in a mouse model of access-related hand dysfunction

Introduction: Hemodialysis via arteriovenous fistula (AVF) is a life-line treatment for patients with end-stage kidney disease. However, hemodialysis access-related hand dysfunction (ARHD) including ischemia, muscle weakness and alterations in mitochondrial function is prevalent following AVF placement. We tested the hypothesis that two-weeks of daily heat therapy prior to AVF surgery would improve hindlimb function in a mouse model of ARHD. Methods: Adult male C57BL/6J mice (N=9-11/group) were fed a 0.2% adenine diet to induce chronic kidney disease. Following two weeks of the initial adenine diet, animals were randomly allocated to heat therapy (HT) or control (CON) groups. Animals assigned to HT were exposed to environmental heat at 40°C in a climate chamber for 30 min/day, six days/week, for two weeks while the control mice were exposed to room temperature (~22°C). The AVF was created using the left common iliac artery and vein 24-48 hours after the last treatment session. Laser Doppler perfusion to the ventral paw was assessed post-operatively (POD) and AVF patency was verified using a high-frequency duplex ultrasound system three days prior to euthanasia. Following 14 days of recovery, in situ tibialis anterior (TA) muscle contractility and gastrocnemius muscle mitochondrial function were assessed. RNA sequencing analysis of the hindlimb skeletal muscle (N=4/group) was performed. Results: Compared to baseline, the level of blood urea nitrogen was similarly elevated ( P<0.05) in both groups following four weeks of adenine diet. In both groups, blood perfusion to the paw was decreased by ~50% immediately after AVF creation and progressively recovered to ~80% at POD13 without a treatment effect ( P=0.4467). No differences in body weight and muscle mass in the TA, extensor digitorum longus, and soleus muscles were observed (all P>0.05). Notably, however, the absolute ( P=0.0250) and specific force ( P=0.0101) frequency relationship of the TA muscle were significantly improved in the animals exposed to HT. In addition, compared with control animals, HT mice had significant improvement in oxidative phosphorylation (OXPHOS) in both pyruvate ( P=0.0145) and octanoylcarnitine ( P=0.0196) fueled conditions. RNA sequencing results revealed that genes involved in nervous system development and metabolism were significantly different between HT and CON groups. Conclusion: Daily application of heat therapy for two weeks prior to the AVF surgery has beneficial effects on both skeletal muscle contractile and mitochondrial function suggesting this pre-habilitation strategy may mitigate the risk of ARHD in patients undergoing AVF surgery. Funding Support: National Institutes of Health grant R01HL148597 and American Heart Association grant POST903198. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Investigation on heat transfer characteristics of multi-duct Trombe wall based on multi-mode heat exchange in winter

For the areas where solar energy resources are available and the demand is high, the low heat transfer efficiency of the traditional Trombe wall needs to be solved, so this study combines the traditional Trombe wall with tubular solar collectors and proposes a form of Trombe wall with multi-pipe and multi-heat transfer modes. Numerical simulation analysis is conducted based on the measured data near the wall surface of residential buildings in Zhengzhou City, China, in December. The thermal performance of different heat transfer modes is evaluated based on the simulation results, and the structural form of the multi-duct Trombe walls is optimized. The results show that the coupled heat transfer mode achieves the highest thermal efficiency. Compared with the traditional interlayer heat transfer mode, the coupled heat transfer mode has a faster start-up speed and more stable performance, with a 27.8 % increase in average daily thermal efficiency and a 36 % increase in heating capacity. Research has found that the 9-duct multi-duct Trombe wall performs better in terms of overall performance. Increasing the number of branch pipes further has limited effect on improving thermal performance. When the diameter of the heat collection branch pipe is 60 mm, the multi-duct Trombe wall achieves the highest average daily thermal efficiency of 70.3 %; adopting a non-uniform pipe distribution mode with the center distance of the middle 5 branch pipes being twice that of the other branch pipes, the Trombe wall achieves the highest average daily thermal efficiency and heating capacity.

Influence of air-conditioning intermittent operation on the cooling load from opaque envelopes in residences

Air-conditioning (AC) intermittent operation is extensively employed owing to occupancy regulations and residents' habits. This conditioning operation type significantly affects the indoor air temperature as a result of the on-off cycles of AC, leading to potential high temperature differences between adjacent rooms due to varying operation rules. Based on this, numerical simulations were done to deal with the overall thermal behavior of typical bedrooms under intermittent operation, and the individual contributions from different envelope components were discussed considering four models of AC operation in adjacent rooms. The results demonstrate that optimizing these four envelope components can lower average transient heat flows by 16.6 %–65.03 % with the consideration of the operation model. Among these components, the ceiling exhibited the highest energy efficiency potential with a reduction ratio of up to 42.8 %. Furthermore, the AC operation model in adjacent rooms had a significant impact on cooling load, and optimizing these four envelope components greatly reduced thermal disturbances from neighboring rooms. The fluctuation percentage of daily heat transfer capacities decreased from 33.89%-37.16 % to 20.64%–23.76 %. Specifically, optimizing opaque envelopes resulted in reductions in heat transfer capacities by 32.06 % and 30.48 % respectively, with ceilings contributing most significantly at 15.1 % and 14.2 %.

The 2018 Heat Wave’s Impact on the Mortality of Older People in Seoul, South Korea

ABSTRACT Few studies on social welfare in South Korea have examined the effects of climate change, especially heat waves on vulnerable populations. The present study aims to investigate how heat waves affect vulnerable populations. This study utilized a cross-sectional study design, using the daily heat index and heat-related mortality data for Seoul, South Korea, in summer 2018. The research used micro-raw data of deaths caused by hypertensive, ischemic heart, and cerebrovascular diseases, as well as heat index data. An effect was observed for the heat index on mortality for individuals over 65 years of age, men, people with spouses, and those ages 75–79 years.

Ambient heat exposure and kidney function in patients with chronic kidney disease: a post-hoc analysis of the DAPA-CKD trial

Higher temperatures are associated with higher rates of hospital admissions for nephrolithiasis and acute kidney injury. Occupational heat stress is also a risk factor for kidney dysfunction in resource-poor settings. It is unclear whether ambient heat exposure is associated with loss of kidney function in patients with established chronic kidney disease. We assessed the association between heat index and change in estimated glomerular filtration rate (eGFR) in participants from the DAPA-CKD trial in a post-hoc analysis. DAPA-CKD was a randomised controlled trial of oral dapagliflozin 10 mg once daily or placebo that enrolled participants aged 18 years or older, with or without type 2 diabetes, with a urinary albumin-to-creatinine ratio of 200-5000 mg/g, and an eGFR of 25-75 mL/min per 1·73 m2. In this post-hoc analysis, we explored the association between time-varying daily centre-level heat index (ERA5 dataset) and individual-level change in eGFR in trial participants using linear mixed effect models and case-time series. The DAPA-CKD trial is registered with ClinicalTrials.gov, NCT03036150. Climate and eGFR data were available for 4017 (93·3%) of 4304 participants in 21 countries (mean age: 61·9 years; mean eGFR: 43·3 mL per 1·73 m2; median 28 months follow-up). Across centres, a heat index of more than 30°C occurred on a median of 0·6% of days. In adjusted linear mixed effect models, within each 120-day window, each 30 days' heat index of more than 30°C was associated with a -0·6% (95% CI -0·9% to -0·3%) change in eGFR. Similar estimates were obtained using case-time series. Additional analyses over longer time-windows showed associations consistent with haemodynamic or seasonal variability, or both, but overall estimates corresponded to an additional 3·7 mL per 1·73 m2 (95% CI 0·1 to 7·0) loss of eGFR per year in a patient with an eGFR of 45 mL per 1·73 m2 located in a very hot versus a temperate environment. Higher ambient heat exposure is associated with more rapid eGFR decline in those with established chronic kidney disease. Efforts to mitigate heat exposure should be tested as part of strategies to attenuate chronic kidney disease progression. None.

Bedrock morphology influences rock barrens turtle nesting habitat energy dynamics.

Energy absorption and flow through a nest is an important aspect of embryonic development in many reptile species including turtles. To date, few studies have explicitly attempted to quantify the energy flow through turtle nests, opting instead for the simplified approach offered by temperature index models. However, the quantification of the energy can provide an explicit abiotic link that can link biological models to biometeorological and ecohydrological processes and models. We investigated the energy flow through turtle nests occupying different bedrock morphologies within a Canadian Shield Rock Barren landscape, in Ontario, Canada. The taxons studied were Spotted Turtle (Clemmys guttata), Midland Painted Turtle (Chrysemys picta marginata), and Blanding's Turtle (Emydoidea blandingii). Nest temperature and soil moisture were measured in 2018 and 2019 using sensors placed in the soil adjacent to 12 turtle nest cavities. Three main rock morphologies were identified for each nest location, Crevice, Ledge, and Flat types, that are in order of decreasing bedrock percentage contact with the nest site. Ground heat flux and change in heat storage were determined using the calorimetric method for each nest, while the direction of energy flux between the atmosphere and the underlying rock was also determined. The Crevice nest morphology experienced the lowest ground heat flux on average (1.56 × 10-1 W m-2) and lowest cumulative heat storage (230 MJ) compared to the Flat (440 MJ) and Ledge (331 MJ) nests. However, over the diurnal cycle, large heat gains by Flat nests were mostly balanced out by nighttime heat losses. While Crevice nests saw the lowest daily heat storage gains, they experienced much lower heat losses over the evening period compared to the other nest types. Furthermore, we found that 59% of the energy is directed from the underlying bedrock into the Crevice nest, highlighting the importance of the bedrock in controlling thermal dynamics in the turtle nesting habitat. The lower variability in energy parameters for Crevice nest types can be attributed to higher amounts of nest-to-bedrock contact, compared to the flat nest types. Our results indicate that Crevice morphology may be ideal for turtles nesting at their northern limits because minimal heat loss during the evening can result in a more stable thermal incubation environment. Future conservation and habitat restoration efforts should consider the importance of bedrock morphology and prioritize the protection of Crevice nest sites. Furthermore, this work highlights important opportunities for potential interdisciplinary work between ecologists, climatologists, biologists, and hydrologists, specifically the integration of ecohydrological and biological models. This work also underscores the potential uncertainty of climate change impacts on turtle egg hatching success and nest sex ratios.

Analysis of Solar Radiation Differences for High-Voltage Transmission Lines on Micro-Terrain Areas

The stable operation of high-voltage transmission lines is significantly affected by atmospheric icing. Research on the physical processes of icing and de-icing of transmission lines in micro-terrain, as well as the factors affecting them, is a crucial theoretical foundation for enhancing current icing prediction capabilities and guiding the planning of transmission lines in mountainous areas. The difficulty lies in the fact that, unlike the calculation of surface radiation, the amount of radiation received by the lines is affected by a combination of terrain, environmental shading, and the orientation of the lines. Therefore, this work initially establishes a method for calculating the total amount of radiant heat received per unit length of the line throughout the day at various heights from the ground, based on the angle of solar incidence and the three-dimensional spatial position of the lines. Furthermore, a method of mapping the regional heat radiation by gridding the direction of the lines was proposed, providing the daily heat radiation and equivalent Joule heat. The proposed mapping method supports anti-icing planning for high-voltage transmission lines in micro-terrain areas.

Feasibility Investigation of Geothermal Energy Heating System in Mining Area: Application of Mine Cooling and Aquifer Thermal Energy Exploitation Technique

Mine heat hazards have resulted in large amounts of high-quality coal resources in deep that cannot be mined. The mining industry is paying more and more attention to the extraction and utilization of geothermal energy in mines, while at the same time reducing the underground temperature to realize co-extraction of coal and heat. In addition, coal mines tend to burn large amounts of coal to heat mine buildings and provide hot water for workers’ daily baths, creating operating costs and increasing greenhouse gas emissions. Therefore, it is of great significance to investigate the feasibility of extracting geothermal energy to provide the daily heat load for mines. Currently, there is little research on the feasibility of geothermal energy extraction and utilization in productive mines instead of abandoned mines. In this study, according to the actual situation of Xinhu mine in eastern China, a combined geothermal water system and heat-pump heating system is proposed, aiming to effectively realize mine cooling and geothermal exploitation and utilization. The geothermal storage capacity in the area is analyzed, and an economic analysis is developed. The economic analysis indicates that the main factors affecting the feasibility of the system are the number of mine users, the distance from the geothermal production well to the mine buildings, and the coal price. The research shows that the economic efficiency of the system is better when the heating scale is larger and the distance is smaller. As coal prices rise, the combined geothermal water and heat-pump heating system will be more economical than traditional coal heating. If a mine has 2000 workers, the application of this system can prevent 334.584 t of CO2 emissions per year.

Heat Exposure, Preterm Birth, and the Role of Greenness in Australia

Preterm birth (PTB) is associated with adverse health outcomes. The outcomes of heat exposure during pregnancy and the moderating association of greenness with PTB remain understudied. To investigate associations between heat exposure, greenness, and PTB, as well as interactions between these factors. Included in this cohort study were births occurring in Sydney, New South Wales, Australia, between 2000 and 2020, retrieved from New South Wales Midwives Data Collection. Participants with incomplete or missing data on their residential address or those who resided outside of New South Wales during their pregnancy were excluded. Data were analyzed from March to October 2023. Greenness measured using normalized difference vegetation index (NDVI) and tree cover derived from satellite images. Daily extreme heat and nighttime extreme heat were defined as above the 95th percentile of community- and trimester-specific daily mean temperatures and nighttime temperatures. Logistic regression models estimated the independent association of extreme heat with PTB, adjusting for individual- and area-level covariates, season of conception, and long-term trend. An interaction term between extreme heat exposure and greenness was included to explore potential modification. With a significant interaction observed, the number of preventable heat-associated PTBs that were associated with greenness was estimated. A total of 1 225 722 births (median [IQR] age, 39 [38-40] weeks; 631 005 male [51.5%]) were included in the analysis, including 63 144 PTBs (median [IQR] age, 35 [34-36] weeks; 34 822 male [55.1%]). Compared with those without heat exposure, exposure to daily extreme heat and nighttime extreme heat in the third trimester was associated with increased risks of PTB, with an adjusted odds ratio (OR) of 1.61 (95% CI, 1.55-1.67) and 1.51 (95% CI, 1.46-1.56]), respectively (PTB rates: exposed, 4615 of 61 338 [7.5%] vs unexposed, 56 440 of 1 162 295 [4.9%] for daily extreme heat and 4332 of 61 337 [7.1%] vs 56 723 of 1 162 296 [4.9%] for nighttime extreme heat). Disparities in associations between extreme heat exposure and PTB were observed, with lower odds of PTB among pregnant individuals residing in greener areas. The associations between extreme heat exposure and PTB could be mitigated significantly by higher greenness. Improving NDVI and tree cover could reduce daily extreme heat-associated PTB by 13.7% (95% CI, 2.3%-15.1%) and 20.9% (95% CI, 5.8%-31.5%), respectively. For nighttime extreme heat-associated PTB, reductions were 13.0% (0.2%-15.4%) and 17.2% (4.1%-27.0%), respectively. Results of this large birth cohort study suggest that extreme heat exposure was adversely associated with PTB, with greenness playing a moderating role. Increasing greenness levels in residential communities could prevent heat-associated PTBs. These findings emphasize the importance of integrating heat mitigation strategies and improving green space in urban planning and public health interventions.

Numerical Study of the Solar Energy-Powered Embedded Pipe Envelope System

This study introduces a Solar Energy-Powered Embedded Pipe Envelope System (SEPES) designed to enhance indoor thermal comfort and reduce heating loads during the heating season. To achieve this objective, a dynamic simulation model coupling a SEPES and building thermal environment was established under the TRNSYS environment. Based on the model, a case analysis was conducted to investigate the operational characteristics of the system during the heating season in a rural building in Beijing. The results indicate that, on the coldest heating day, the system can elevate the indoor temperature by 14.5 °C, reducing the daily heat load from 76.3 kWh to 20.3 kWh, achieving a remarkable energy savings of 73.4%. Additionally, due to the utilization of lower solar heat collection temperatures, the energy efficiency of the system reaches 26.9%. Throughout the entire heating season, the SEPES system enhances the natural indoor temperature by 13.3 °C to 16.6 °C, demonstrating significant effectiveness. Moreover, regional adaptability analysis indicates that the SEPES achieves energy savings ranging from 43.9% to 66% during the heating season in cold regions and regions with hot summers and cold winters in China. Overall, the SEPES is most suitable for climates characterized by both low temperatures and abundant solar radiation in order to achieve optimal performance.