Lower Average Temperature Research Articles

Statistical characteristics of heterogeneous ice nucleation temperature for sessile saltwater droplets on supercooled solid surfaces

The formation of ice nuclei in seawater droplets on supercooled solid surfaces is a prevalent phenomenon in nature and industrial applications. However, the statistical characteristics and mechanism of types of salt affecting their nucleation temperature remain poorly understood. This study experimentally investigates the nucleation process of saltwater droplets on solid surfaces, focusing on the effects of salinity, droplet volume, and the types of salt on nucleation temperature. The results reveal that the nucleation temperatures of saltwater droplets with varying salinities, volumes, and types of salt exhibit stochastic behavior and conform to a normal distribution. As salinity increases or droplet volume decreases, the nucleation temperature distribution broadens, shifts toward lower temperatures, and shows a decline in the average nucleation temperature. Furthermore, nucleation rates decrease with reduced droplet volume, increased salinity, or higher temperature. For droplets containing different types of salt, MgCl2 and CaCl2 droplets exhibit lower average nucleation temperatures and nucleation rates compared to LiCl, NaCl, and KCl droplets, with MgCl2 showing the lowest values. In contrast, LiCl, NaCl, and KCl droplets exhibit no notable differences. This trend is inversely correlated with the energy required during nucleation (the sum of dehydration energy and the energy barrier) for droplets containing different cations. These results offer valuable insight into the nucleation behavior and mechanisms of seawater droplets on supercooled solid surfaces, advancing the understanding and optimization of desalination technologies for seawater droplet freezing.

Impact of Room Colors and Construction Materials on Temperature Distribution in Tropical Climate: An Experimental Study in Nonthaburi, Thailand

This experimental research investigates the thermal performance of different room colors and construction materials under Thailand's tropical climate conditions. The study was conducted over a six-month period in Nonthaburi, Thailand, examining temperature variations across multiple room configurations. Using precision monitoring equipment, we analyzed how traditional Thai building materials and various wall colors affect indoor temperature distribution. The research encompassed both modern and traditional Thai construction materials, including concrete, brick, traditional teak wood, and bamboo, combined with different wall colors (white, cream, terra cotta, and dark blue). Results demonstrated that rooms with traditional materials like teak wood maintained lower average temperatures (by 3.2°C) compared to modern concrete structures, while light-colored walls showed up to 4.1°C temperature difference compared to darker colors during peak sunshine hours.

Anti-inflammatory Properties of Hibiscus Leaf Extracts: A Potential Therapeutic Agent for Post-immunization Fever in Infants

Post-immunization fever is a common side effect in infants, often causing discomfort and concern for parents. Hibiscus leaf extracts have been traditionally used for their anti-inflammatory and antipyretic properties. This study investigated the efficacy of hibiscus leaf extracts as a potential therapeutic agent for post-immunization fever in infants. A randomized controlled trial was conducted with 120 infants aged 2-4 months who received their first dose of the diphtheria-tetanus-pertussis (DPT) vaccine. Participants were randomly assigned to either the hibiscus extract group (n=60) or the control group (n=60). The hibiscus extract group received a standardized dose of hibiscus leaf extract orally, while the control group received standard care. Fever was assessed at regular intervals for 48 hours post-immunization. Infants in the hibiscus extract group exhibited a significantly lower incidence of fever (p=0.02) and a reduced duration of fever (p=0.04) compared to the control group. Furthermore, the hibiscus extract group showed a lower average temperature throughout the observation period. No adverse effects were reported in the hibiscus extract group. In conclusion, hibiscus leaf extracts demonstrate promising anti-inflammatory properties and may serve as a safe and effective therapeutic agent for post-immunization fever in infants. Further research is warranted to explore the underlying mechanisms and long-term effects.

Evaluation of the cooling performance of various heat-reflective cool pavement coatings for Urban Heat Island mitigation

Abstract This paper investigates the optimization of heat-reflective cool pavement coatings to address the critical Urban Heat Island (UHI) effect, which significantly increases energy consumption for urban cooling and adversely impacts thermal comfort and public health. With pavements constituting about 30% of urban surfaces, their role in amplifying UHI effects underscores the need for innovative solutions. This study evaluated the cooling effect of heat reflective coatings (HRC) using water-based and oil-based binders, such as Acrylic Emulsions and Epoxy Resins, with the addition of functional fillers and pigments, including Titanium oxide, Iron oxide, and Silicon oxide. The results showed that both waterborne (acrylic emulsion) and oil-based (epoxy resin) HRC significantly reduced pavement surface temperatures, achieving maximum cooling effects of up to 20°C. During nighttime cooling simulations, these coatings maintained lower average temperatures, demonstrating their effectiveness both day and night. Waterborne HRC exhibited a rougher surface texture, resulting in higher skid resistance compared to the smoother epoxy resin HRC, which poses a potential risk for skid resistance and requires anti-skid additives. However, waterborne HRC showed signs of cracking after 24 hours of drying, indicating lower durability. Incorporating SiO2 maintained the cooling performance of epoxy resin HRCs while reducing glossiness, enhancing safety and efficacy. Conversely, SiO2 reduced the cooling effect in acrylic emulsion HRCs, suggesting that their natural matte appearance is already optimal. While yellow and white HRCs have high cooling effects, they may not be suitable for all applications due to potential glare and aesthetic mismatches, particularly in architectural and heritage settings.

Topology optimization of microreactors for hydrogen production by ammonia catalytic decomposition

Microreactor is a promising technique for producing hydrogen by ammonia catalytic decomposition. In this study, a topology optimization (TO) model is developed to optimize the distribution of porous catalysts in microreactors to improve the conversion from ammonia (NH3) to hydrogen (H₂), which considers the fully coupled processes of flow, heat transfer, mass transport and reaction with variable physical properties. Dual objectives of reducing the flow resistance and decreasing the average temperature of the microreactor are employed for the TO model to generate innovative structures. The effects of different weight coefficients, input heat, volume fractions of the catalyst, and microreactor sizes on TO structures are explored. As validated by three-dimensional (3D) simulations, the TO microreactor can obtain lower pressure drop, lower average temperature, and higher NH3 conversion compared to traditional microreactors. At a weight coefficient of 0.95 and a catalyst volume fraction of 0.6, the optimized microreactor shows a 5.78% increase in NH3 conversion, an 18.05% decrease in pressure drop, and a 4.26% decrease in average temperature compared to the traditional straight-channel microreactor. Finally, it is interesting to find that all TO structures generated are characterized by the gradually decreased size of the catalyst block along the flow direction which allows more NH3 to be decomposed at higher temperature regions with higher reaction rates, leading to higher conversion. The present study provides valuable insights for the design of next generation microreactors with enhanced performance.

Combining pin-fins and superhydrophobic surfaces to enhance the performance of microchannel heat sinks

Electronics cooling and thermal management presents an immense challenge to the electrification of society. From mobile devices to stationary systems, power densification of electronics platforms is putting pressureon thermal systems. This research uniquely combines superhydrophobic surfaces with pin-fin structures to investigate their combined effects on thermal performance and fluid dynamics. We examine the impact of superhydrophobic surfaces on different internal walls for both finned and non-finned microchannels. Three-dimensional finite volume method simulations are used to analyze fluid flow and heat transfer, with surface wettability modeled using a custom user-defined function. The results of the simulations were first validated against experimental data. Thermal-hydraulic performance for finned and non-finned microchannels was studied for both conventional and superhydrophobic surfaces. Superhydrophobic properties on different internal surfaces of the microchannel yielded different outcomes for finned versus non-finned designs. We show that superhydrophobic surfaces are effective in enhancing the performance of finned channels at high Reynolds number (Re). At Re = 500, finned microchannels with superhydrophobic side walls have the same performance factor (η) as a conventional microchannel without fins with a 9.4 °C lower average base surface temperature. Additionally, superhydrophobic side walls increase the pressure drop and Nusselt number by 8.9 % and 6.6 %, respectively, compared to conventional non-superhydrophobic finned surfaces. Conversely, superhydrophobic top and bottom surfaces reduce the pressure drop and Nusselt number by 13 % and 18.5 %, respectively. Our findings reveal that the location and intensity of vortices, influenced by fins, vary with different superhydrophobic surface configurations.

Multi-Omics Analysis Uncovers the Mechanism for Enhanced Organic Acid Accumulation in Peach (Prunus persica L.) Fruit from High-Altitude Areas.

The early-ripening peach industry has undergone rapid development in the Panxi region of the Sichuan Basin in recent years. However, after the introduction of some new peach varieties to the high-altitude peach-producing areas in Panxi, the titratable acid content in peach fruit has significantly increased. This study compared the fruit quality indicators of early-ripening peach varieties cultivated in Xide County (a high-altitude peach-producing area) and Longquanyi District (a low-altitude peach-producing area) in Sichuan Province and analyzed the differences in organic acid metabolism by combining primary metabolomic and transcriptomic approaches. The results showed that the 'Zhongtaohongyu' fruit from the high-altitude peach-producing area had a much higher accumulation of malic acid and, accordingly, a significantly higher organic acid content than the other samples. The lower annual average temperature and stronger ultraviolet radiation in high-altitude peach-producing areas may lead to the increased expression of genes (PpNAD-ME1, PpNADP-ME3, and PpPEPC1) in the organic acid synthesis pathway and the decreased expression of genes (PpACO2, PpNAD-MDH2/3/4/5, and PpPEPCK2) in the organic acid degradation pathway in peach fruit, ultimately resulting in the accumulation of more organic acids. Among them, the downregulation of the key genes PpNAD-MDH3/4/5 involved in malic acid metabolism may be the main reason for the higher malic acid accumulation in peach fruit from high-altitude peach-producing areas. Overall, this study elucidates the mechanism by which environmental factors enhance the accumulation of organic acids in peach fruit from high-altitude peach-producing areas from a multi-omics perspective, as well as providing a theoretical basis for screening key genes involved in organic acid metabolism in peach fruit.

Numerical Simulation of the Effects of Compartment Height, Fire Source Location, and Vent Location on Compartment Fire Phenomena with a Ceiling Vent

In this study, the numerical simulations of the effects of compartment height, fire source location, and vent location on the compartment fire phenomena with a ceiling vent were performed. Under the same fire source and vent location conditions, the compartment height of 5.5 m showed a higher mass flow rate across the vent than that of 11 m. For the fire source at the center, the vent on the left showed a lower mass flow rate than that at the center for both compartment heights. For the fire source on the left, the vents on the right and left exhibited the lowest mass flow rates at the compartment heights of 5.5 m and 11 m, respectively. Moreover, for the fire source on the left, a macroscopic rotational flow in the clockwise direction was observed at the compartment height of 5.5 m, whereas at the compartment height of 11 m, macroscopic rotational flows in the clockwise and counterclockwise directions appeared at its lower and upper portions, respectively. It was confirmed that these macroscopic rotational flows were closely related to the change in the mass flow rate across the vent with the vent location. The compartment height of 11 m had a lower average temperature inside the compartment than that of 5.5 m, which was because of the increase in the surrounding wall area. In addition, under each compartment height condition, the changes in the average temperature inside the compartment with the fire source and vent locations were minor.

Geo-climatic factors co-drive the phenotypic diversity of wild hemp (Cannabis sativa L.) in the Potohar Plateau and Lesser Himalayas

Hemp (Cannabis sativa L.) is an annual, and dioecious herb belonging to the Cannabaceae family. This plant is native to Central and Southeast Asia. The wild races of this species are commonly growing in Khyber Pakhtunkhwa and Punjab provinces, as well as in Islamabad, Pakistan. This study provides crucial insights into how environmental variables influence the wild hemp populations, which can be utilized in for conservation and breeding. The present study was aimed at evaluating the effects of key environmental factors such as altitude, geographical location, precipitation, relative humidity, maximum, minimum, and average temperature on 16 morpho-agronomic traits of a wild population of hemp growing in the Potohar Plateau and Lesser Himalayas. Our findings indicated that high relative humidity (> 64%), low average temperature (< 15 °C), intermediate average temperature (19–22 °C), and high average temperature (> 22 °C) played significant roles in determining the distribution pattern of the wild hemp. Correlation analysis demonstrated that average annual temperature contributed a higher percentage of variation in phenotypic diversity than geographic variables. Additionally, cluster analysis indicated three groups for the selected 35 populations. Clustering and Principal Component Analysis (PCA) of the morpho-agronomic traits indicated that group 1 from the Lesser Himalayas showed high relative humidity (> 64%) and low average temperature (< 15 °C). Conversely, Group 2 populations from the Potohar Plateau demonstrated intermediate average temperature (19–22 °C). There is an existence of Group 3 in the Potohar Plateau with a high average temperature (> 22 °C) compared to Group 1 and Group 2. Our examination highlights the complex interplay between ecological factors, and morphological attributes in native landraces of Cannabis sativa, giving significant insight into knowledge for preservation and breeding initiatives. A study of genetic diversity could complement morpho-agronomic traits in future research to learn more about how genetic variation affects environmental adaptation.

Coexpression Regulation of New and Ancient Genes in the Dynamic Transcriptome Landscape of Stem and Rhizome Development in "Bainianzhe"-An Ancient Chinese Sugarcane Variety Ratooned for Nearly 300 Years.

The sucrose yield in sugarcane largely depends on stem morphology, including length, diameter and sugar content, making sugarcane stem a key trait in breeding. The "Bainianzhe" variety from Songxi County, Fujian Province, possesses both aerial stems and rhizomes, providing a unique model for studying stem development. We performed a spatiotemporal transcriptomic analysis of the base, middle and apical sections of both aerial stems and rhizomes. The analysis categorized transcriptomes by developmental stage-base, middle and apical-rather than environmental differences. Apical segments were enriched with genes related to cell proliferation, while base segments were linked to senescence and fibrosis. Gene regulatory networks revealed key TFs involved in stem development. Orphan genes may be involved in rhizome development through coexpression networks. Plant hormones, especially genes involved in ABA and GAs synthesis, were highly expressed in rhizomes. Thiamine-related genes were also more prevalent in rhizomes. Furthermore, the apical segments of rhizomes enriched in photosynthesis-related genes suggest adaptations to light exposure. Low average temperatures in Songxi have led to unique cold acclimation in Bainianzhe, with rhizomes showing higher expression of genes linked to unsaturated fatty acid synthesis and cold-responsive calcium signalling. This indicates that rhizomes may have enhanced cold tolerance, aiding in the plant's overwintering success.

Lightweight and highly heat-resistant copolymerized polyimide foams for superior thermal insulation and acoustic absorption

The development of lightweight and highly heat-resistant polyimide foams (PIFs) remains a great challenge in areas of aerospace, military ships, transportation, and industries. Herein, a series of lightweight and highly thermal-resistant copolymerized PIFs are successfully fabricated by the “stepwise heating-holding” thermal foaming of the copolymerized polyester ammonium salts (C-PEAS), using 3,3′,4,4′-benzophenone tetracarboxylic acid dianhydride (BTDA) and 2,3,3′,4′-biphenyl tetracarboxylic acid dianhydride (α-BPDA) as codianhydride, and p-phenylenediamine (PDA) as diamine. The introduction of α-BPDA increases the rigidity of PI molecule chains and foamability of C-PEAS, and significantly improves the heat resistance of PIFs. The resultant copolymerized PIFs exhibit ultra-low densities (<10 kg m−3), excellent heat resistance (Tg ranging from 351.2 °C to 405.6 °C), and high thermal stability. Moreover, they possess high flame retardancies (LOI>44 %) and low thermal conductivities (as low as 0.0463 W m−1 K−1 at 20 °C and no more than 0.0825 W m−1 K−1 at 200 °C), demonstrating their excellent thermal insulation properties in a wide temperature range. After the continuous heating at 200 °C for 40 min, the upper surface of PIFs present low average temperatures less than 60 °C. Additionally, the copolymerized PIFs exhibit remarkable acoustic properties with average acoustic absorption coefficients above 0.6 and noise reduction coefficients (NRC) above 0.3. Therefore, the lightweight and highly heat-resistant copolymerized PIFs show great application potentials in the extreme environments of aerospace, military ships, transportation, and industries.

Comparison and mechanism study on solidification of loose pisha sandstone by indigenous bacteria and sporosarcina pasteurii

Pisha sandstone is a kind of sandstone which is easy to collapse by water in Shanxi, Shaanxi and Inner Mongolia of China, and suffers from hydraulic erosion all the year round. In recent years, some scholars have used microbial induced calcium carbonate precipitation (MICP) technology to solidify Pisha sandstone to improve the water erosion resistance of Pisha sandstone. However, for the climate environment with low average temperature in Pisha sandstone area, the commonly used Sporosarcina pasteurii are not well adapted. The purpose of this study is to use the indigenous strainsto solidify the loose Pisha sandstone, and to compare the growth adaptability, mechanical properties and water erosion resistance of the solidified layer with Sarcina pasteurii at different temperatures, and to explore the mechanism of different temperatures and strains affecting the microbial solidification of Pisha sandstone from the micro scale. At the same time, a mixed bacterial liquid solidification test was also set up. The results showed that the solidified thickness of indigenous strains was 4.65 % higher than that of Sporosarcina pasteurii, and the thickness and strength of mixed strains were increased by 19.57 % and 36.62 %, respectively. The growth and solidification effect of indigenous strains were less affected by low temperature. Compared with Sporosarcina pasteurii, at low temperature, the bacterial concentration decrease of indigenous strains was reduced by 26.13 %, the thickness loss of solidified layer was reduced by 13.04 %, and the strength loss of solidified layer was reduced by 13.39 %. The effect of low temperature on the growth of bacteria is mainly reflected in affecting the maximum concentration of bacteria and the growth rate. The effect on MICP mainly reflected in affecting the life activities of bacteria and the crystal form and morphology of calcium carbonate. The research results provide a theoretical basis for the MICP technology application of indigenous strains and multi-strains in Pisha sandstone area soil reinforcement and solidification slope.

Sustainable Rubber Production Intercrop with Mixed Fruits to Improve Physiological Factors, Productivity, and Income

This study investigated the impact of various rubber intercropping models on productivity, income, and physiological factors, compared to rubber monocropping in Tamod subdistrict, Phatthalung province, Thailand. Three intercropping models from rubber smallholder farms with mature Hevea trees were evaluated: rubber with timber trees (RT), rubber with timber and fruit trees (RTF), and rubber with timber, fruit, and shrub trees (RTFS). The rubber monoculture served as the control treatment. Data was collected from May 2021 to April 2022. Results revealed that intercropping had an 11.3% lower Tapping Panel Dryness incidence than monocropping (88.7%). The RTFS model had the highest latex yield at 1,866.31 kg/ha/year and dry rubber content at 40.11%, outperforming the other models. In the RTF model, fruit yields were 809, 92, 458, and 61 kg/ha/year for Durio zibethinus L., Lansium domesticum, Garcinia mangostana, and Nephelium lappaceum L. The RTFS model had a Salacca zalaca fruit yield of 1,220 kg/ha/year. Environmentally, the RTFS model had the lowest average temperature (30.5°C), highest humidity (68.8%), and lowest light intensity (2,955 lux) compared to the other models. Soil moisture tension was also least negative in RTFS at -5.7 kPa and -5.3 kPa at 30cm and 50cm depths. Economically, the RTF model had the highest net profit at 4,892 USD/ha/year with a benefit-cost ratio of 2.75 and a return on investment of 176%. Sensitivity analysis showed RTF maintained the highest profits even with ±10% changes in revenue and costs. Rubber intercropping, particularly the RTFS model, improved productivity, income, and environmental conditions compared to monocropping.

No-impact trajectory design and fabrication of surface structured CBN grinding wheel by laser cladding remelting method

The structured grinding wheels have a specially designed macro or microstructure on the surface, with a relatively low average grinding force and temperature in the cutting zone and more space for chips and coolant. Most traditional grinding wheel fabrication methods, such as electroplating, sintering, and brazing, have the problems of poor abrasive grain holding strength, random abrasive distribution, or thermal deformation of the substrate. To address this, laser cladding remelting technology is introduced to fabricate the structured CBN grinding wheel. A no-impact trajectory was designed on the substrate of the grinding wheel, which can reduce the fluid friction in the channel and increase the fluid pressure at the outlet. The temperature and velocity fields of the grinding process were simulated to verify the feasibility of the designed structure theoretically. The optimal process parameters for the bonding among the metal bond, the abrasive grains, and the substrate were determined by orthogonal and full-scale factorial experiments. The chemical metallurgical reactions between CBN grain and metal bond, as well as between the metal bond and substrate, were formed, increasing the holding force of CBN grains. The method can realize the fabrication of high-strength and long-life structured grinding wheels with an orderly arrangement of abrasive grains. The micro-mechanism of fabrication was analyzed using element distribution measurement and XRD analysis.

Thermal characteristics analysis and cooling model optimization of motorized spindle

Aiming at the influence of poor cooling conditions and traditional cooling control strategy on motorized spindle temperature and machining performance. Firstly, the heat transfer model of the motorized spindle cooling system is studied. Secondly, the influence of coolant inlet flow rate and temperature on the thermal characteristics of the motorized spindle is studied. Then, a thermal network model is established to solve the temperature of each temperature measuring point. Finally, the thermal characteristic experiment of the motorized spindle is carried out, and the cooling fluid flow optimization model is established based on the particle swarm optimization algorithm and simulated annealing algorithm. The results show that the temperature difference of the motorized spindle does not exceed 45 °C, the thermal deformation does not exceed 40.2 μm, and the thermal elongation is inhibited by 36 %. The maximum error of the Thermal Network Method and Finite Element Method（FEM）is 14.24 %. The utilization of the average logarithmic temperature difference for assessing the cooling effectiveness of optimal flow rates revealed that the particle swarm optimization algorithm demonstrates a comparatively lower average logarithmic temperature difference in comparison to the simulated annealing algorithm. The heat exchange efficiency of the motorized spindle is higher under the optimal flow rate obtained by the particle swarm algorithm.

Inter‐row soil management affecting soil moisture in non‐irrigated vineyard ecosystems: A meta‐analysis

AbstractSoil moisture or soil water content (SWC) is crucial for ecosystem functioning, affecting plant health and soil quality. Imbalances in soil moisture can result in reduced fruit production and altered soil biotic and abiotic parameters. Vineyards, especially those located on sloping terrains, or in less fertile soils, are highly susceptible to these issues. An effective nature‐based solution to reduce erosion, improve soil health and increase the biodiversity of soils in vineyards is implementing green cover in the inter‐row spaces. However, trade‐offs related to green cover management need to be carefully evaluated to ensure optimal outcomes. Therefore, we conducted a literature review and a meta‐analysis to analyse how soil water content changes when a green cover (perennial grass or cover crops) management method is used in a vineyard compared to no vegetation or tilled inter‐rows. We found 70 data sets concerning soil water content (SWC) in non‐irrigated vineyards involving tillage and green cover. The data revealed that SWC enhancement depends on the type of green cover, as perennial grass (GC) tended to increase SWC (on average by 15%), whereas cover crops (CC) decreased overall SWC (on average by 20%). Sub‐humid climates showed 35%–73% higher SWC compared to semi‐arid research sites. Temperature zones also revealed that the lower (&lt;12°C) average annual air temperature sites had the highest SWC. In general, the highest average SWC in GC also included the highest soil organic carbon (SOC) content and the lowest average bulk density (1.41 g cm−3) in the data set. However, changes in overall bulk density values were not significant among inter‐row soil management. We found that green cover generally increases penetration resistance (22% for GC and 61% for CC) and reduces the saturated hydraulic conductivities of the soils (i.e. 30% for GC and 79% for CC). However, our data set shows high deviations between research sites' values and climatic conditions, and while there are numerous benefits of green cover use in vineyard inter‐rows, site‐specific assessment is highly recommended prior to making changes in management practices.

Study on the Influence of Structural Parameters of Microwave Heating Device on the Heating Effect of Natural Gas Hydrate Reservoir

Abstract The investigation into microwave heating technology for enhancing gas production from hydrate reservoir has attracted wide attention. However, the initial microwave heating device structure still has limitations of low average temperature and uneven temperature distribution in the reservoir during microwave heating. This study has established the microwave heating simulation model, which is validated by the reservoir microwave heating experiment results. Based on the simulation results of microwave heating model, the optimized structure parameters of microwave heating device are obtained: the slots distribution method is cross-distribution, the slot shape is rectangle, the slot angle is 75°, and the slot length is 30 mm. Following microwave heating with the optimized structure for 10 hours, the average temperature within the 1-meter radius of the reservoir rises from 2 °C to 9.52 °C, the maximum temperature in the reservoir is 58.21 °C, and the temperature standard deviation is 9.15 °C. The results mentioned above indicate that the optimized structure can well increase the temperature in the gas hydrate reservoir and the temperature distribution is uniform. This study will further promote the application of microwave heating technology in the actual exploitation of natural gas hydrate.

An experimental setup for studying conduction and radiation heat transfer in a rotary drum

This study presents the development of a novel heating system that aims to bridge the experimental gap for analyzing both radiation and conduction heat transfer in a rotary drum. The experiments were conducted by loading the drum with 4 mm silica glass beads at varying fill levels (10 %, 17.5 %, and 25 %) and rotation rates (2, 5, and 10 RPM), and monitoring the temperature evolution with an infrared camera. Higher fill levels resulted in lower average particle bed temperatures, while rotation rate influenced the contact time between particles and the drum wall and the exposure to radiative heat. A rotation rate of 5 RPM resulted in the highest average bed temperature due to optimal contact and exposure time for conduction and absorption of radiative heat, respectively. Thus, a balance between adequate particle mixing and optimal contact/exposure time is crucial for maximizing heat transfer efficiency in rotary drums exhibiting conduction and radiation.

Modernization of small-sized drying plant for searching optimal modes with thermovision control

The climatic features of the Murmansk region (low average annual temperature; insignificant number of sunny days) do not contribute to the effective use of natural methods of drying aquatic organisms and determine the use of artificial dehydration methods using appropriate equipment. The capabilities of ship fish processing complexes are limited; highly productive coastal fish processing plants are required to supply the population with fish products. The development and testing of new drying modes has been carried out using a small-sized drying unit UPOR-M2. In the course of the study, a drying unit modernization project has been developed, equipment has been selected (thermal imaging system; damper and fan control modules), the system has been modernized and a number of experiments has been conducted to determine the effectiveness of the work performed. The modernization of the drying unit has made it possible to increase the accuracy of the data obtained by 25 % (temperature), 20 % (relative humidity), 18 % (weight), to implement remote control of the processes and to ensure reliable operation of the drying system. Further research of different drying modes for aquatic organisms should include upgrading the air supply control system and improving communication equipment.

The impact of air temperature and humidity on Children’s blood pressure mediated by Lipids: A prospective cohort study

ObjectivesFew studies illustrate the mechanism between air temperature and blood pressure (BP) in childhood. This study aims to investigate the associations between air temperature, humidity exposure, and BP trajectories in children and adolescents, and explore the potential mediating roles of lipid profiles in these relationships. MethodsThis prospective cohort study included 5,971 children with 10,800 person-times measurements at baseline from the Chongqing Health Cohort, with evaluations conducted in 2014–2015 (baseline) and follow-ups in 2016 (urban areas) and 2019 (urban and rural areas). Multilevel mixed-effects models were used to analyse the impacts of air temperature and humidity on BP levels and the incidence of elevated BP, while accounting for potential confounders. Mediation analyses were performed to evaluate the mediating effects of lipid profiles, including low-density lipoprotein (LDL), total cholesterol (TC), and specific lipid species. ResultsAfter adjusting for covariates, higher air temperature quartiles were associated with both decreased BP levels and elevated BP risk (RR: 0.83; 95 % CIs: 0.78, 0.89; P = 0.028). Conversely, higher humidity quartiles exhibited a U-shaped relationship with BP levels. Greater variability in air temperature was linked to increase BP levels. The cumulative effects of air temperature exposure on BP were significant from pregnancy to age 10, with females exhibiting larger effects (β:-3.291, 95 % CIs: −4.242,-2.340, P < 0.001). LDL and TC partially mediated the associations between air temperature and BP levels, particularly in males. Specific lipid species, including SM (d21:1), LPC (17:0), and PC (O-36:3), also exhibited significant mediating effects. ConclusionsThis study provides novel insights into the intricate interplay between air temperature, humidity, lipid metabolism, and blood pressure regulation in children. Lower average temperatures and extreme humidity levels were associated with increased risks of elevated BP, potentially mediated by lipid profiles. Early interventions targeting air temperature exposure and lipid metabolism could mitigate hypertension risk, promoting improved cardiovascular outcomes in children.