Search Results (210)

The aim of this experiment was to determine whether reticulorumen temperature (ReT), rumination, activity or pH captured by a rumen sensor bolus system (smaXtec animal care GmbH, Graz, Austria) can be used as an early indicator of heat load (HL) and to assess how its daily patterns are influenced by diurnal effects. Physiological and behavioral data from 70 male feedlot cattle (Uckermärker, Hereford, Simmentaler) housed in a closed barn were investigated using the calculated temperature-humidity index (THI) from remote HOBO Onset climate sensors over a period of 210 days. Using time series analysis and seasonal ARIMA modeling, it was found that ReT followed the same patterns throughout days with a THI < 74 as well as days under heat load conditions. Time series and correlation analyses were also performed for the rumen pH, rumination index and activity index. The collective mean ReT over the winter days assessed (n = 14,971) was 39.48 °C, with a minimum mean of 38.31 °C and a maximum mean of 40.69 °C. In comparison, the collective mean ReT over the summer days assessed (n = 14,030) was 39.53 °C, with a minimum mean of 38.39 °C and a maximum mean of 42.02 °C. Pearson’s correlation did not reveal a relationship between THI and ReT (r = −0.06; p < 0.001) and only minimally for rumination (r = −0.11; p < 0.001). Rumination clearly decreased with increasing ambient temperature in comparison to days with a THI < 74. A long-term effect is also visible when the monthly mean rumination from all bulls tends to decrease slightly from February to May and then increases beginning in June. The mean pH values decreased throughout the summer months. Nevertheless, the comparison between daily fluctuations in pH values under HL failed to yield significant deviations from those captured on days of winter. The Pearson correlation for rumen pH showed a weak negative linear relationship with THI (r = −0.3; p < 0.001). The monthly means of the motion activity index could also not verify that HL led to increasing activity (Pearson correlation for motion activity and THI: r = 0.04; p < 0.001). The heat load had no visible short-term effects on the ReT or rumen pH, but rumination and peak motion activity were reduced on days with high ambient temperatures. Full article

This study investigates the characteristics, meteorological drivers, and transport pathways of air pollution in Yining City from 2020 to 2024 based on meteorological records and air pollutant monitoring data. An integrated modeling approach combining the Weather Research and Forecasting (WRF) model and the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model was employed. Results reveal an overall annual decrease in ambient pollutant concentrations in Yining, with PM_2.5 and PM₁₀ consistently below the national secondary standards, In contrast, the O₃ concentration shows a marked yearly increase. Pronounced seasonal variations were identified: the elevated O₃ concentrations in summer were driven by high temperatures and intense solar radiation. The significant increase in PM_2.5 and PM₁₀ concentrations during winter was predominantly attributed to coal-based heating emissions and temperature inversion conditions. Pollutant concentrations were strongly associated with gaseous precursors (e.g., CO and NO₂) and meteorological factors. Higher temperatures and lower relative humidity aggravated O₃ formation, whereas lower temperatures and higher relative humidity favored PM_2.5 pollution. Correlation analysis revealed that NO₂ and CO showed the strongest correlations with PM_2.5 (r = 0.84) and O₃ (r = −0.62), respectively. Backward trajectory analysis revealed that higher pollution levels were associated with air masses originating from the southwest and southeast. Full article

Background: Cutaneous synthesis of vitamin D depends primarily on exposure to solar ultraviolet B (UVB) radiation. Nevertheless, populations in the Mediterranean region, including pregnant women, continue to experience high rates of hypovitaminosis D. Pregnancy is a particularly vulnerable period due to increased physiological demands and reduced outdoor activity. The aim of this study was to examine the seasonal and environmental determinants of maternal and neonatal vitamin D status in an urban Greek population. Methods: We conducted a cross-sectional observational study on 248 pregnant women and their neonates admitted for delivery at Tzaneio General Hospital of Piraeus between September 2019 and January 2022. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured and temporally matched with environmental variables including UV index, sunshine hours, ambient temperature, and PM2.5 levels. Results: Both maternal and neonatal 25(OH)D levels exhibited marked seasonal variation, with levels peaking in late summer and declining sharply in winter. A significant positive correlation was observed between UV index and vitamin D concentrations (r = 0.45, p < 0.001), while elevated PM2.5 concentrations were inversely associated with vitamin D status. Despite supplementation, insufficiency persisted in most neonates, particularly during the low-UV season. This underlines the need for comprehensive prenatal care strategies, integrating both supplementation policies and individualized nutritional counseling, to better secure maternal and neonatal vitamin D adequacy. Conclusions: Seasonal and environmental factors, particularly solar radiation and particulate air pollution, have a decisive role in determining maternal and neonatal vitamin D status, even in regions with abundant sunlight. These findings emphasize the importance of adaptive prenatal care strategies that combine supplementation with dietary counseling and take into account seasonal variation and air quality. In addition, the study provides novelty by integrating maternal–neonatal vitamin D status with environmental exposure metrics such as UV and PM2.5. Full article

This study evaluates the thermal comfort and energy performance of Qiang Zhuangfang manor houses in high-altitude regions, using Mao County’s Heihuzhai settlement as a representative case. Field surveys, tabulated data analysis, and computer simulations were conducted to measure wall surface temperature, ambient radiation temperature, air temperature, and relative humidity, comparing Zhuangfang buildings with brick Qiang houses. Results show that Zhuangfang walls have minor surface temperature differences, lower thermal conductivity, and superior insulation—retaining heat in winter, blocking heat in summer, and reducing solar gain. Optimization measures were tested through a model, revealing that lowering the main structure by 0.1 m and adding a surface material layer improved insulation while maintaining load-bearing capacity. The findings confirm that Zhuangfang houses are better suited to the local climate, offering ecological benefits in energy saving and heat preservation. Full article

Atmospheric formaldehyde (HCHO) is a major component of oxygenated volatile organic compounds (OVOCs) and plays an important role in O₃ formation and atmospheric oxidation capacity. In this study, seasonal observations of gaseous pollutants (HCHO, O₃, peroxyacetyl nitrate (PAN), CO, NOx, and VOCs) and ambient conditions (J_HCHO, J_NO2, solar radiation, temperature, relative humidity, wind speed, and wind direction) were conducted in a coastal city in southeast China. The average HCHO concentrations were 2.54 ppbv, 3.38 ppbv, 2.53 ppbv, and 1.98 ppbv in spring, summer, autumn, and winter, respectively. Diurnal variations were high in the daytime and low in the nighttime, and the peak times varied in different seasons. The correlation between HCHO and O₃ was not significant in spring and winter, which is likely related to the effects of photochemical reactions and diffusion conditions. The contributions of background (23.0%), primary (47.6%), and secondary (29.4%) sources to HCHO were quantified using multiple linear regression (MLR) models, revealing that secondary formation was the most significant contributor in summer, whereas primary emissions were predominant in spring. These findings help to improve the understanding of the influence of atmospheric formaldehyde on photochemical pollution control in coastal cities. Full article

This study examines the dynamic response of autoclaved aerated concrete (AAC) under solar radiation and ambient temperature coupling. A comparative analysis is conducted between traditional sintered bricks (brick), AAC, and autoclaved aerated concrete sandwich insulated wall panels (ATIM), using three thermal engineering models. The experimental group focuses on the south wall, with differentiated designs: Model A (brick), Model B (AAC), and Model C (ATIM). Temperature data collectors assess heat transfer and internal temperature regulation in winter. The results show that the AAC sandwich system significantly reduces thermal fluctuations, with a 26% and 14.8% attenuation in temperature amplitude compared to brick and AAC. The thermal inertia index of the AAC sandwich structure system is 51.5% and 14.58% higher than that of traditional brick walls and AAC walls, respectively. The heat consumption index of ATIM is, on average, 14% lower than that of AAC and 74.5% lower than that of the brick system. The study confirms that the AAC sandwich rock wool wall structure enhances temperature stability and energy efficiency, supporting green building and low-carbon energy-saving goals. Full article

This study investigates the effects of ambient temperature on NO_x (NO + NO₂) emissions from model year 2011 and later heavy-duty (HD) diesel vehicles. Emission measurements were collected in Perry, Utah, using the Fuel Efficiency Automobile Test (FEAT) remote sensing device. Data were limited to model year 2011 and later to focus on vehicles likely equipped with selective catalytic reduction (SCR) systems, which control tailpipe NO_x emissions and are shown to be temperature sensitive. HD diesel vehicles measured in the winter of 2020 had consistently higher NO_x emissions than those measured in the summer of 2023, most significantly for vehicles aged 0 to 3. A non-linear model fit to the data that accounts for age effects, predicts fleet-average NO_x emissions to be two times higher at colder ambient temperatures (−4.4 °C, 24 °F) than warmer ambient temperatures (28.1 °C, 82.5 °F). The temperature effect from this study supports temperature effects observed in other studies measuring real-world emissions from HD diesel vehicles. One possible improvement to the accuracy of NO_x emission inventories could be including a temperature effect for SCR-equipped HD diesel vehicles. Full article

This study evaluates the energy performance and efficiency of a low-concentration photovoltaic (CPV) system integrated with a phase change material (PCM), referred to as the CPV–PCM system, which stores and delivers thermal energy for building applications. A paraffin-based PCM with a melting point range of 58–60 °C was selected to align with typical building temperature requirements. The system was tested over three consecutive days in July at Al Ain, United Arab Emirates, under extreme climatic conditions (2100 W/m² solar irradiance, 35–45 °C ambient temperature), and its performance was compared to standard CPV and traditional tracked PV systems. The results demonstrate that PCM integration significantly enhances thermal regulation, reducing CPV peak temperatures by 38 °C (from 123 °C to 85 °C) and average temperatures by 22 °C (from 88 °C to 66 °C). The CPV–PCM system achieved a total energy efficiency of 60%, doubling that of standard CPV (30%) and tracked PV (25%), with cumulative electrical and thermal energy outputs of 370 Wh and 290 Wh, respectively. This dual electrical–thermal output enables the system to meet building heating demands, such as ~200–300 Wh/m² for domestic hot water and ~100–150 Wh/m² for space heating in United Arab Emirates winters, positioning it as a sustainable solution for energy-efficient buildings in arid regions. The findings underscore the advantages of PCM-based thermal control in CPV systems for hot climates, addressing gaps in prior studies focused on moderate conditions. Future research should explore long-term durability, optimized containment techniques, and alternative PCMs to further improve performance. Full article

This study presents a novel switchable multi-inlet Building integrated photovoltaic/thermal (BIPV/T) curtain wall system designed to enhance solar energy utilization in commercial buildings. The system integrates controllable air inlets and motorized dampers that dynamically adjust airflow patterns in response to real-time environmental conditions such as solar irradiance, ambient air temperature, and PV panel temperature. A steady-state energy balance model, developed using a thermal network analogy and implemented in Python, was used to simulate winter operation in Montréal, Canada. Three operating modes with different air inlet configurations were assessed to evaluate system performance across variable air velocities and solar conditions. Results indicate that the switchable system improves combined thermal and electrical generation by 2% to 25% compared to fixed one- or two-inlet systems. Under low irradiance and air velocity, one-inlet operation is dominant, while higher solar gain and airflow favor two-inlet configurations. The system demonstrates effective temperature control and enhanced energy yield through optimized airflow management. This work highlights the potential of integrated control strategies and modular façade design in improving the efficiency of solar building envelope systems and offers practical implications for scalable deployment in energy-efficient, heating-dominated climates. Full article

Electric buses (EBs) are increasingly adopted for their environmental and operational benefits, yet their real-world efficiency is influenced by climate, route characteristics, and auxiliary energy demands. While most existing research identifies winter as the most energy-intensive season due to cabin heating and reduced battery performance, this study presents a contrasting perspective based on a three-year longitudinal analysis of the LYMMO fleet in Orlando, Florida—a subtropical U.S. region. The findings reveal that summer is the most energy-intensive season, primarily due to sustained HVAC usage driven by high ambient temperatures—a seasonal pattern rarely reported in the current literature and a key regional contribution. Additionally, idling time exceeds driving time across all seasons, with HVAC usage during idling emerging as the dominant contributor to total energy consumption. To mitigate these inefficiencies, a proxy-based HVAC energy estimation method and an optimization model were developed, incorporating ambient temperature and peak passenger load. This approach achieved up to 24% energy savings without compromising thermal comfort. Results validated through non-parametric statistical testing support operational strategies such as idling reduction, HVAC control, and seasonally adaptive scheduling, offering practical pathways to improve EB efficiency in warm-weather transit systems. Full article

Ningxia has emerged as a strategic hub for China’s photovoltaic (PV) industry by leveraging abundant solar energy resources and geoclimatic advantages. This study analyzed the spatiotemporal expansion trends and microclimatic impacts of PV installations (2015–2024) using Gaofen-1 (GF-1) and Landsat8 satellite imagery with deep learning algorithms and multidimensional environmental metrics. Among semantic segmentation models, DeepLabV3+ had the best performance in PV extraction, and the Mean Intersection over Union, precision, and F1-score were 91.97%, 89.02%, 89.2%, and 89.11%, respectively, with accuracies close to 100% after manual correction. Subsequent land surface temperature inversion and spatial buffer analysis quantified the thermal environmental effects of PV installation. Localized cooling patterns may be influenced by albedo and vegetation dynamics, though further validation is needed. The total PV site area in Ningxia expanded from 59.62 km² to 410.06 km² between 2015 and 2024. Yinchuan and Wuzhong cities were primary growth hubs; Yinchuan alone added 99.98 km² (2022–2023) through localized policy incentives. PV installations induced significant daytime cooling effects within 0–100 m buffers, reducing ambient temperatures by 0.19–1.35 °C on average. The most pronounced cooling occurred in western desert regions during winter (maximum temperature differential = 1.97 °C). Agricultural zones in central Ningxia exhibited weaker thermal modulation due to coupled vegetation–PV interactions. Policy-driven land use optimization was the dominant catalyst for PV proliferation. This study validates “remote sensing + deep learning” framework efficacy in renewable energy monitoring and provides empirical insights into eco-environmental impacts under “PV + ecological restoration” paradigms, offering critical data support for energy–ecology synergy planning in arid regions. Full article

In enzymatic reaction glucose detection chips, the enzyme can easily dislodge from the electrode, which harms both the chip and test stability. Additionally, enzyme activity significantly decreases at low temperatures. Consequently, immobilizing the enzyme at the appropriate substrate and ambient temperature is a critical step for improving the chip. To address this issue, an electrochemical detection chip was modified using the nanomaterial MXene, known for its large specific surface area, excellent adsorption, good dispersion, and high conductivity. Meanwhile, AgNO₃ solution was added to the Ti₃C₂T_x MXene nanosheet solution, and the AgNP@MXene material was prepared by heating in a water bath. This process further enhances photothermal conversion efficiency due to the localized surface plasmon resonance effect of silver nanoparticles and MXene. This MXene-based photothermally enhanced paper chip exhibits outstanding photothermal conversion performance and sensitive photoelectrochemical responsiveness, along with good cycling stability. Moreover, improved glucose detection sensitivity at low winter temperatures has been achieved, and the ambient temperature range of the paper chip has been expanded to 25–37 °C. Full article

Controlling low ambient temperatures and ammonia levels is critical for effective environmental management in poultry houses during winter, as both represent persistent stressors affecting bird health and productivity. However, evidence regarding their combined long-term effects on the physiological responses of laying hens remains limited. In this study, 576 eighteen-week-old Hy-Line Brown hens were randomly assigned to six treatments (8 replicates with 12 birds per replicate each treatment) and housed in environmentally controlled chambers for 20 weeks: T1 (8 °C, ≤5 ppm ammonia), T2 (8 °C, 20 ppm ammonia), T3 (8 °C, 45 ppm ammonia), T4 (20 °C, ≤5 ppm ammonia; control), T5 (20 °C, 20 ppm ammonia), and T6 (20 °C, 45 ppm ammonia). Plasma samples were collected at 22, 26, 30, 34, and 38 weeks to evaluate physiological stress biomarkers (corticosterone, CORT; total antioxidant capacity, T-AOC), immunoglobulins (IgG, IgM, and IgA), and reproductive hormones (luteinizing hormone, LH; follicle-stimulating hormone, FSH; estradiol, E2). At 38 weeks, hypothalamus, pituitary, and spleen tissues were collected to assess the relative mRNA expression of gonadotropin-releasing hormone (GnRH), FSH, tumor necrosis factor-α (TNF-α), and interleukins (IL-1β, IL-6, and IL-10). Results showed that both cold and ammonia stress reduced antioxidant capacity, disrupted immune homeostasis, and altered reproductive hormone profiles. Cold exposure induced acute immunoendocrine alterations with partial physiological adaptation over time, whereas ammonia exerted progressive and cumulative damage, including elevated immunoglobulins (IgG and IgM) and downregulation of GnRH and FSH expression. Combined exposure significantly upregulated TNF-α and IL-1β expression, suggesting a synergistic inflammatory response. These results highlight complex, parameter-specific interactions between cold and ammonia stressors, emphasizing the need for targeted environmental strategies. Stage-specific interventions—thermal regulation in early laying and ammonia control in later phases—are recommended to safeguard hen health and optimize productivity under winter conditions. Full article

With the intensification of the global energy crisis, the application of air-source transcritical CO₂ heat pumps has attracted increasing attention, especially in cold regions. Existing research mainly focuses on the evaluation of steady-state performance while paying less attention to the dynamic characteristics of the system during the actual operation process. In order to deeply study the dynamic performance of the air-source transcritical CO₂ heat pump system under the winter climate conditions in the Yan‘an area, this study established a system simulation model with multiple parameter inputs and systematically analyzed the influences of ambient temperature, discharge pressure, and inlet and outlet water temperatures on the heating capacity and COP. The research starts from both dynamic and steady-state perspectives, revealing the variation law of system performance with environmental temperature and conducting a quantitative analysis. As the ambient temperature rose from −11 °C to 2 °C, the COP of the system increased by approximately 15% and exhibited significant dynamic response characteristics, indicating that the increase in ambient temperature significantly improved system efficiency. At different ambient temperatures, the optimal discharge pressure increased with the rise in temperature. At the highest ambient temperature (2 °C), the optimal discharge pressure was 11.7 MPa. Compared with the optimal discharge pressure of 11.0 MPa at −11 °C, the performance improved by nearly 13.3%. Through the dynamic simulation method, theoretical support is provided for the optimization of energy-saving control strategies in cold regions, and thoughts are offered regarding the application of transcritical CO₂ systems under similar climatic conditions. Full article

Air pollution is a major environmental risk factor that contributes significantly to the global burden of disease, particularly through its impact on respiratory and cardiovascular health. The aim of this study is to investigate the temporal variations of ambient air pollutants and the influence of MPs (MPs) on their concentrations in the metropolitan area of Tehran from 2017 to 2021. Hourly data for PM_2.5, PM₁₀, O₃, NO₂, SO₂, and CO from all air quality monitoring stations were obtained. Effects of MPs for the same period were assessed. The results revealed that Tehran’s residents are continuously exposed to harmful levels of PM_2.5 (5.7 to 6.3 times), PM₁₀ (4.5–5.6 times), and NO₂ (8.7–10.0 times) that are significantly higher than the updated World Health Organization (WHO) air quality guidelines. All other air pollutants (except for O₃) showed the lowest and highest concentrations during summer and winter, respectively. The highest concentration of O₃ was found on weekends (weekend effect), while other ambient air pollutants had higher levels on weekdays (holiday effect). Although other air pollutants exhibited two peaks, in the morning and late evening, the hourly concentration of O₃ reached its maximum level at 3:00 pm. Approximately 51% to 65% of the Air Quality Index (AQI) values were classified as unhealthy for sensitive groups. Throughout the study period, PM_2.5 was identified as the primary pollutant affecting air quality in Tehran. Among MPs, temperature was the most important factor in increasing the concentration of O₃, while the other ambient pollutants decreased under the influence of wind speed. Given the current situation, effective and evidence-based air quality management strategies, like those that have been successfully applied elsewhere, are now a necessity to avoid the public health impact and economic losses from air pollution. Although this research focuses on Tehran as a model case of rapidly developing cities facing severe air quality challenges, the findings and recommendations have broader applicability to similar urban environments worldwide. Full article