Lower Average Temperature Research Articles

Heat Transfer Performance of Water-cooled Heat Sink for I&C System Controller Chip in Nuclear Power Plant

To improve the heat dissipation reliability of the nuclear power control system chip, the structure of its water-cooled heat sink is compared and analyzed. Three schemes of water-cooled heat sinks are proposed, and CFD analyzes the heat dissipation performance of the heat sink. The simulation data of the heat transfer coefficient, pressure loss, and heat sink comprehensive coefficient are compared. The results show that the average temperature of the bottom surface of the three heat sinks tends to be flat with the flow velocity increase, and the heat dissipation coefficient Nu is also the same. The S-type heat sink has a higher heat transfer coefficient and lower average bottom temperature. The pressure loss of the S-type heat sink is much higher than that of the other two schemes with the increased flow rate, and the system resistance is large. By calculating the comprehensive coefficient of the heat dissipation process of the three heat sinks and considering the heat dissipation capacity and other factors, it is considered that the circular fin heat sink can be the optimal solution.

Association between ambient particulate matter and preterm birth stratified by temperature: A population-based pregnancy cohort study.

A growing body of literature reports associations between exposure to particulate matter with aerodynamic diameters ≤2.5μm (PM2.5) and 2.5-10μm (PM10-2.5) during pregnancy and preterm birth (PTB). However, the role of ambient temperature in PM-PTB associations was rarely investigated. In Israel, we used Maccabi Healthcare Services data to establish a population-based cohort of 381,265 singleton births reaching 24-42 weeks' gestation and birth weight of 500-5000g (2004-2015). Daily PM and ambient temperature predictions from a satellite-based spatiotemporal model, at a 1×1km spatial resolution, were linked to the date of birth and maternal residence. Mixed effects Cox regression models, adjusted for covariates, with a random intercept at the mother level were used to assess associations between mean exposure during pregnancy and PTB. We found that exposure to PM2.5 was positively associated with PTB when the average exposure during pregnancy was either low (first quintile) or high (fifth quintile), compared to exposure in the 2nd-4th quintiles, with hazard ratios (HRs) 1.18 (95% confidence interval [CI], 1.13-1.24) and 1.07 (95% CI, 1.02-1.12), respectively. The results revealed effect modification of temperature. For mothers exposed to low (below median) average temperature during pregnancy, HRs of PTB were 0.93 (95% CI, 0.87-1.00) and 1.21 (95% CI, 1.14-1.29) for the first and fifth PM2.5 quintiles, respectively, when compared to the 2nd-4th quintiles. However, a reverse trend was indicated for high-temperature pregnancies, where the corresponding HRs were 1.48 (95% CI, 1.39-1.58) and 0.92, (95% CI, 0.96-0.98). In conclusion, consideration of climatic factors can provide new insights into the risk of PTB as a result of exposure to PM2.5 during pregnancy.

Occurrence of putative Culicoides biting midge vectors (Diptera: Ceratopogonidae) inside and outside barns in Germany and factors influencing their activity

BackgroundAfter several years without bluetongue disease, a ruminant illness caused by Culicoides-borne bluetongue virus (BTV), two new autochthonous cases were reported in 2018 in Germany. By contrast, Schmallenberg virus (SBV), another Culicoides-borne virus pathogenic to ruminants, has continuously circulated in Germany since its first emergence in 2011. The disease outbreaks have triggered numerous studies on the biology of the Culicoides vectors, but many ecological details are still obscure.MethodsCulicoides biting midge species were collected with UV-light traps on 10 farms in Germany, with one trap inside and one trap outside barns on each of the farms. Traps were run once a week for 24 h from January to December 2019. Collected biting midges were morphologically identified, counted and statistically evaluated, with a focus on the Obsoletus Group and the Pulicaris Complex of the ceratopogonid genus Culicoides, which are believed to contain the major virus vectors. Temperature and relative humidity recorded at each trap were linked to the quantity of caught Culicoides. Correlations between relative Culicoides abundance and presence of livestock or type of husbandry were also investigated.ResultsA total of 38,886 Culicoides biting midges were trapped, with most of them belonging to the Obsoletus Group (51.0%) and the Pulicaris Complex (38.8%). The majority of captured specimens were collected in traps inside the barns. Obsoletus Group individuals were caught from late January to the last week of December while Pulicaris Complex individuals were captured from the end of March to early December. The lowest average temperatures at which members of the two groups were collected were 10.7 °C and 12.8 °C, respectively. While temperature had a statistically significant effect on the activity of both the Obsoletus Group and the Pulicaris Complex, relative humidity only significantly affected the activity of the latter. The presence of livestock significantly influenced the number of captured Obsoletus Group, but not of Pulicaris Complex specimens. Inside the barns, no statistical difference was found between numbers of caught Obsoletus Group and Pulicaris Complex specimens in livestock holdings with deep litter and manure scraper or slatted floor husbandry systems.ConclusionsThe almost year-round presence of Obsoletus Group biting midges and the demonstrated high relative abundance of other potential Culicoides vector species inside barns suggest a high risk of indoor virus transmission to ruminants should BTV or SBV circulate locally. Appropriate structural, organisational and vector control measures to reduce biting midge exposure should be implemented.Graphical

Risk factors for intraoperative hypothermia in infants during general anesthesia: A retrospective study.

This study aimed to determine the incidence and evaluate the risk factors and outcomes of intraoperative hypothermia (IH) during general anesthesia in infants. Retrospective analysis of prospectively collected data. A total of 754 infants younger than 1 year old who underwent surgery under general anesthesia were included. Intraoperative body temperature fluctuations, surgical and anesthetic data, postoperative complications, and infant outcomes were recorded. Logistic regression algorithms were used to evaluate potential risk factors. Among the 754 infants, 47.88% developed IH (<36 °C) and 15.4% of them experienced severe hypothermia (<35 °C). The average lowest temperature in hypothermia patients was 35.06 ± 0.69°C with a duration of 82.23 ± 50.59 minutes. Neonates tended to experience hypothermia (37.7% vs 7.6%, P < .001) and prematurity was more common in patients with IH (29.4% vs 16.8%, P < .001). Infants with hypothermia experienced a longer length of stay in the post anesthesia care units and intensive care units, postoperative hospitalizations, and tracheal extubation as well as a higher rate of postoperative hemorrhage than those with normothermia (all P < .05). Several factors were proved to be associated with an increased risk of IH after multivariate analysis: neonate (odds ratio [OR] = 3.685, 95% CI 1.839-7.382), weight (OR = 0.599, 95% CI 0.525-0.683), American society of anesthesiologists (OR = 3.418, 95% CI 2.259-5.170), fluid > 20 mL/kg (OR = 2.380, 95% CI 1.389-4.076), surgery time >60 minutes (OR = 1.785, 95% CI 1.030-3.093), and pre-warming (OR = 0.027, 95% CI 0.014-0.052). This retrospective study found that neonates, lower weight, longer surgery times, more fluid received, higher American society of anesthesiologists stage, and no pre-warming were all significant risk factors for IH during general anesthesia in infants.

Spatio-temporal characteristics and driving factors of flash drought recovery: From the perspective of soil moisture and GPP changes

Flash drought recovery is significant to evaluate the impact of flash drought and the resilience of ecosystem. However, the definition of flash drought recovery stage and its mechanism remain unclear, with limited research in this area. This study proposes the definitions of flash drought recovery stage based on soil moisture change and gross primary productivity (GPP) change. The spatio-temporal characteristics, driving factors and differences between two identifications are investigated in Xiang River Basin (XRB) and Wei River Basin (WRB), two typical humid and semiarid basins in China. The main results are as follows: (1) XRB has a slightly longer recovery time and a higher recovery rate in terms of soil moisture-based definition, while GPP-based definition shows similar recovery times for both basins, with WRB having a higher recovery rate. (2) Based on soil moisture-based definition, the recovery time and recovery rates of different flash drought events in the same basin vary greatly, while most flash drought events in both basins recover within 2*8 days in terms of GPP-based definition. (3) Under both definitions, regions with relatively higher precipitation, lower average temperature and lower solar radiation tend to have higher recovery rates and shorter recovery time. Besides, grasslands tend to recover more quickly from flash drought than forests with GPP-based definition. (4) The recovery stage with soil moisture-based definition begins with the changes in associated meteorological variables, while the recovery stage with GPP-based definition begins 8 to 2*8 days after the changes of meteorological variables occur. This study proposes preliminary definitions for the recovery stage of flash drought and reveals the mechanism underlying the flash drought recovery, which are crucial for understanding the evolution of flash drought and reducing the risks resulting from it.

Quantitative risk assessment of the presence of fumonisin in corn produced in different regions of Brazil: Influence of climatic conditions

In this study, the probability of occurrence of fumonisins in corn in the states of greatest production in Brazil was determined. The data were analyzed through quantitative risk analysis using the Monte Carlo simulation. The results indicated that there is a strong correlation between fumonisins contamination levels and the geographical region due to the influence of climatic characteristics, with temperature having the main influence. The Southern states presented higher risks of occurrence and concentration levels of fumonisins in corn due to the temperate climate with lower average temperature and higher relative humidity and precipitation indices. Cultivation in the best season indicates a significant reduction in the production of fumonisins when this period was evaluated, with average concentration levels up to 42% lower. The generated data are important for regulatory agencies and the agricultural sector, which needs to be aware that the chance of success in grain production depends on efficient planning of the growing season, mainly concerning the climatic conditions to which it is subject to minimize the risks.

Effects of Cooling System Boundary Conditions on the Performance of Proton Exchange Membrane Fuel Cell: A Comprehensive Analysis

Abstract We developed a three-dimensional multiphysics numerical model of a proton exchange membrane fuel cell (PEMFC) with a cathode mesh structure to investigate how coolant flowrate and temperature impact its performance. After experimentally validating the model, we compared the performance of the cathode mesh structure PEMFC with that of the traditional straight-flow PEMFC. The results indicate that the cathode mesh structure PEMFC has a lower pressure drop and a more index of uniform distribution (IUD), leading to enhanced performance, better temperature distribution, and improved water management of the PEMFC. The investigation of the cooling system’s operating parameters revealed that the temperature of the cathode catalyst layer in the PEMFC is the highest, while the temperature of the bipolar plate is the lowest. Of the nine cases that we evaluated, Case 7, with a coolant inlet temperature and flowrate of 303.15 K and 0.07 m/s, respectively, yielded the highest power density and the lowest average temperature. The IUD of the proton exchange membrane (PEM) in Case 5 was 0.608, suggesting that the temperature distribution of the PEM is more uniform when the coolant inlet temperature and flowrate are 323.15 K and 0.05 m/s, respectively. We have demonstrated through calculations a strong correlation between temperature difference and IUDs. These findings have significant implications for the optimization and application of PEMFCs.

Spatial Distribution of Ethnic Villages in the Mountainous Region of Northwest Yunnan and Their Relationship with Natural Factors

The mountainous region of northwest Yunnan is a multi-ethnic region in China where several ethnic groups, such as the Tibetans, Lisu, and Naxi, reside. This study utilises the average nearest neighbour index, kernel density analysis, and GeoDetector (Geographical Detector) to analyse the spatial distribution characteristics of different types of ethnic villages, their correlation with the natural environment, and differences in the influence of various natural environmental factors. The results show the following: (1) the spatial distribution of the three types of ethnic villages in the mountainous region of northwest Yunnan are clustered. (2) Tibetan villages are characterised by high elevation, gentle slopes, proximity to the river, low annual average temperature, and low annual precipitation. Lisu villages are characterised by medium elevation, steep slopes, high annual average temperature, and high annual precipitation. Multi-ethnic villages are characterised by low elevation, medium slopes, proximity to rivers, high annual average temperature, and high annual precipitation. (3) Ethnic villages are affected by various natural factors such as elevation, slope, river buffer zone, annual average temperature, annual precipitation, and ecological environment. Among these, ecological environment has the greatest impact on Tibetan villages, and annual precipitation has the greatest impact on Lisu and multi-ethnic villages. (4) The distribution of the Tibetan villages is mostly constrained by the composite factors of ecosystem and precipitation, while that of the Lisu villages by the composite factors of precipitation and elevation, and that of the multi-ethnic villages by the composite factors of precipitation and temperature.

Effects of Production–Living–Ecological Space Patterns Changes on Land Surface Temperature

Rapid economic and social development has triggered competition for limited land space from different industries, accelerating the evolution of Beijing’s urban landscape types. The increase in impermeable surfaces and the decrease in ecological land have led to an increase in the impact on the urban thermal environment. Since previous studies have mainly focused on the impact of a single urban landscape on the urban thermal environment and lacked an exploration of the combined impact of multiple landscapes, this study applied standard deviation ellipses, Pearson correlation analysis, land surface temperature (LST) profile analysis, and hot spot analysis to comprehensively explore the influence of the evolving production–living–ecological space (PLES) pattern on LST. The results show that the average LST of various spaces continued to increase before 2009 and decreased slowly after 2009, with the highest average temperature being living space, followed by production space, and the lowest average temperature being ecological space for each year. The spatiotemporal shift path of the thermal environment is consistent with the shift trajectory of the living space center of gravity in Beijing; LST is positively correlated with living space (LS) and negatively correlated with production space (PS) and ecological space (ES). LST is positively correlated with LS and negatively correlated with PS and ES. Influenced by the change in bedding surface type, the longitudinal thermal profile curve of LST shows a general trend of “low at both ends and high in the middle”. With the change in land space type, LST fluctuates significantly, and the horizontal thermal profile curve shows a general trend of “first decreasing, followed by increasing and finally decreasing”. In addition, the hot spot analysis shows that the coverage area of very hot spots, hot spots, and warm spots increased by 0.72%, 1.13%, and 2.03%, respectively, in the past 30 years, and the main expansion direction is southeast, and very cold spots and cold spots are distributed in the northwest ecological space, and the area change first decreases and then increases.

Niche suitability and spatial distribution patterns of anurans in a unique Ecoregion mosaic of Northern Pakistan.

The lack of information regarding biodiversity status hampers designing and implementing conservation strategies and achieving future targets. Northern Pakistan consists of a unique ecoregion mosaic which supports a myriad of environmental niches for anuran diversity in comparison to the deserts and xeric shrublands throughout the rest of the country. In order to study the niche suitability, species overlap and distribution patterns in Pakistan, we collected observational data for nine anuran species across several distinct ecoregions by surveying 87 randomly selected locations from 2016 to 2018 in Rawalpindi District and Islamabad Capital Territory. Our model showed that the precipitation of the warmest and coldest quarter, distance to rivers and vegetation were the greatest drivers of anuran distribution, expectedly indicating that the presence of humid forests and proximity to waterways greatly influences the habitable range of anurans in Pakistan. Sympatric overlap between species occurred at significantly higher density in tropical and subtropical coniferous forests than in other ecoregion types. We found species such as Minervarya spp., Hoplobatrachus tigerinus and Euphlyctis spp. preferred the lowlands in proximal, central and southern parts of the study area proximal to urban settlements, with little vegetation and higher average temperatures. Duttaphrynus bengalensis and D. stomaticus had scattered distributions throughout the study area with no clear preference for elevation. Sphaerotheca pashchima was patchily distributed in the midwestern extent of the study area as well as the foothills to the north. Microhyla nilphamariensis was widely distributed throughout the study area with a preference for both lowlands and montane terrain. Endemic frogs (Nanorana vicina and Allopaa hazarensis) were observed only in locations with higher elevations, higher density of streams and lower average temperatures as compared to the other seven species sampled. It is recommended to provide legal protection to amphibians of Pakistan, especially endemic species, through revision in the existing wildlife laws. We suggest studying the effectiveness of existing amphibian tunnels and corridors or designing new ones tailored to the needs of our species to prevent their local extinction due to ongoing or proposed urban development which might affect their dispersal and colonization.

Influence of air ceiling diffusers in enclosed spaces: An experimental and numerical investigation

Within the past few years, IEQ has been a hot topic among building occupants, government officials, and academics all around the globe. Most modern life is spent indoors, in homes, workplaces, and shopping centres. People’s awareness of the need for healthy indoor air quality (IAQ) rises in tandem with their rising standard of living. Along with air temperature, humidity, and cleanliness, air velocity in a climate-controlled room affects the space’s microclimate. In particular, reducing discomfort in enclosed areas is a function of having an adequate distribution of air velocities. This study employs computational fluid dynamics (CFD) models to examine the effects of types of air diffusers in an enclosed office space in Alexandria, Egypt, on the ensuing air velocities and temperature gradients. Model accuracy has been confirmed by comparing numerical simulations to physical measurements. The simulations demonstrated that the square diffuser was superior in temperature distribution uniformity within the office volume but that there was a significant interaction between supply diffusers. The round diffuser had faster velocities in the standing and sitting planes (1.2 and 1.8 m) and a lower average temperature, implying that it can be employed with a reduced fan speed than the square diffuser, reducing overall power use.

180 Effect of leg wraps on skin temperature in exercising horses

Tendon or ligament injuries are common in performance horses and have a negative impact on training time and economics in all equestrian disciplines. There are some factors that increase the risk of tendon and ligament injury including fitness level, overexertion, and tendon core temperature. In vitro studies have shown fibroblast death at tendon core temperatures of 43° to 48°C, suggesting that repeated hyperthermic events may predispose the horse to tendon or ligament injury. The distal limb of the horse houses tendons and ligaments only, and is often covered in boots or polo wraps during exercise to protect the limb from trauma. Previous studies of exercising horses have compared distal limb skin temperature under solid boots, perforated boots, and polo wraps, and found that increased airflow is important to reduce skin temperature and likely tendon core temperature. Currently on the market are several brands of polo wraps that claim to promote airflow and keep the limb cooler during exercise than traditional coverings. The objective of this study was to investigate this claim and compare the distal limb skin temperature under a traditional pair and 2 brands of cooling polo wraps during and after exercise. Using a HOBO TidbiT MX Temperature Data Logger taped on the skin halfway between the ergot and accessory carpal bone, a total of 5horses were used to test a different covering each day: traditional fleece polo wrap, cooling wrap 1, and cooling wrap 2. The temperature under the wraps was recorded during exercise and for an additional 5 min afterward at rest. For all 3 treatment conditions, the median was used as the measure of center for the distributions of average temperature change because the distributions for the cooling wraps were highly right skewed. Because of the small sample size, a Friedman test (P = .05) was conducted to determine if there was a significant difference in the average heat buildup between the 3 treatments. The median of the average temperature change was 4.24°C for the regular fleece polo wrap, 3.50°C for cooling wrap 1 and 2.70°C for cooling wrap 2. There were no statistically significant differences found in the distributions of average temperature across the 3 treatments (P = 0.247). However, the data did show a trend of lower average temperature under the cooling wraps compared with the traditional fleece wraps. These results prompt further study of larger sample size, time to plateau and cool down under the wraps, and temperatures under more rigorous exercise to fully evaluate the difference between treatments.

Influence of Living Mulch and Nitrogen Dose on Yield and Fruit Quality Parameters of Malus domestica Borkh. cv. ‘Sampion’

This study was conducted to estimate the yield, and to identify and quantify primary and secondary metabolites in fruit of Malus domestica Borkh. cv. ‘Sampion’ under two agrotechnical factors: the floor management (herbicide fallow and living mulch) and the dose of nitrogen (50, 80, 110, and 140 kg ha−1). Compared to herbicide fallow, living mulch did not decrease yield. Research showed a rich composition of phenolic and volatile organic compounds in apples, which varied with the evaluated factors, as well as with the weather conditions during the vegetation season. The precipitation deficit and high summer temperatures did not contribute to proper fruit growth and development and led to a higher content of phenolic compounds in the fruit flesh from trees in herbicide fallow compared to living mulch. Living mulch, which could be a factor regulating the availability of nitrogen to trees, stimulated the synthesis of anthocyanins, which was also potentiated by low average temperatures at harvest time, resulting in a large area of fruit skin red blush.

Плотность древесины сосны обыкновенной в осушаемом сосняке сфагновом

The task of increasing forest productivity has been and remains one of the current interests of the European North of Russia, especially after the period of primary development of the forest areas. In the European Northeast, excessive humidity is observed at rather low average temperatures, which prevents active surface evaporation. In the twentieth century, the hydrotechnical reclamations were conducted on the large areas of swampy forests that increased the total productivity. The ecologists have an ambivalent attitude concerning forest draining. The supporters, who try to protect the undisturbed forest territories, counteract such activities. At the same time, the cultivation of highly productive forests of the right composition and quality requires measures for natural afforestation, or artificial forests must be created. Besides the total productivity of the stands, wood quality is an important factor in the hydroamelioration. It is mainly determined by density and the ratio between early and late wood. The influence of the landscape peculiarities of the drained forests on the quality of the wood was examined by the devotion of the areas according to the most typical groups of microrelief: flat areas, elevations, transitional areas. In cases of extensive humidity, the death of seedlings and artificial forest plantings was observed (soaking, frost extrusion, etc.). The creation of micro-elevations and the drainage of the excessive moisture guarantee the regeneration and establishment of the highly productive forests. The differences in the density of pine wood before and after the hydrotechnical reclamation were detected according to the landscape. The largest changes in the indicator were determined at the elevations and the flat areas, with the increase and the decrease, respectively. The trees that grow on the flat terrain after the reclamation show a relative excess of early wood over late wood, while at the elevations the presence of the late wood is predominant. For citation: Zagorodski M.A., Tretyakov S.V., Koptev S.V. Density of Scots Pine Wood in Drained Sphagnum Pine Forest. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 2, pp. 160–171. (In Russ.). https://doi.org/10.37482/0536-1036-2023-2-160-171

Estimation of spatio-temporal distribution of 137Cs concentrations in litter layer of forest ecosystems in Fukushima using FoRothCs model

The nuclear power plant accident in Fukushima had led to pollution of forest ecosystems with 137Cs in 2011. In this study, we simulated the spatiotemporal distribution of 137Cs concentrations of litter layer in the contaminated forest ecosystems in two decades from 2011, which is one of the key environmental components of 137Cs migration in the environment due to the high bioavailability of 137Cs in the litter. Our simulations showed that 137Cs deposition is the most important factor in the degree of contamination of the litter layer but vegetation type (evergreen coniferous/deciduous broadleaf) and mean annual temperature are also important for changes over time. Deciduous broadleaf trees had higher initial concentrations in the litter layer due to the direct initial deposition on the forest floor. However, the concentrations remained higher than those in evergreen conifers after 10 years due to redistribution of 137Cs by vegetation. Moreover, areas with lower average annual temperatures and lower litter decomposition activity retained higher 137Cs concentrations in the litter layer. The results of the spatiotemporal distribution estimation of the radioecological model suggest that, in addition to 137Cs deposition, elevation and vegetation distribution should also be considered in the long-term management of contaminated watersheds, which can be informative in identifying hotspots of 137Cs contamination on a long-term scale.

Impact of circular economy on the decarbonization of the Italian residential sector

Circular economy is a new economic model that aims at overcoming today's linear “take, make, dispose” pattern, decoupling global economic development from finite resource consumption. Household appliances are a promising field for the adoption of Circular Economy, being one of the most resource-intensive industries and due to the global e-waste problem. The aim of this work is to quantify the potential contribution of making the household appliances sector more circular to the decarbonization of the Italian energy system, using the TIMES-RSE model. First, a literature review of the available circular measures was performed and used as a basis for modeling assumptions. The following circular measures were considered: extending the lifetime of appliances, increased adoption of remanufactured appliances, growing importance of leasing, lower average washing temperature for washing machines, and lower usage of tumble dryers. Second, each circular practice was modeled either as a new technology available for the optimization of the system or as a change in demand for a certain commodity. The reference scenario is the Italian Long Term Strategy. It is shown that the modeled circular practices can reduce the energy consumption of household appliances in 2050 by 0,327 Mtoe (−16%) and cut in half their costs through the 2020–2050 period, saving 96 billion euros (−47%). Moreover, savings could be even higher if efforts are taken to remove barriers to their diffusion, including consumers' habits and manufacturers' inertia. As the energy weight of appliances is low within the overall residential sector, energy savings of these circular practices are negligible at the sectoral level, however, economic savings of 107 billion euros are achieved over 2020–2050 (−22%).

Changes in soil total nitrogen induced by crop residue return: A meta-analysis

Residue return has a profound effect on soil total nitrogen (STN) content and thereby the global soil N cycle. However, a specific understanding of the key factors influencing STN changes after residue return is currently lacking. A meta-analysis of 502 comparisons from China based on 152 published papers was performed to quantify the changes in STN after residue return and assess the effect sizes of the predictor variables. Results showed that residue return significantly increased STN in 0–20 cm by 11.1% compared to no residue return. The STN accumulation accompanying return of crop residues was greater in areas with higher latitude (>40°), lower rainfall (<700 mm) and lower average annual temperature (<5 °C) such as in Northeast China. Crop management, climatic factors, soil properties, residue management and fertilizer addition all significantly affected STN after residue return. Land use and mean annual precipitation (MAP) were the most influential predictors of the changes in STN following residue return. The results of structural equation model showed that the duration of residue return, the amount of residue, and the initial STN content of the soil had direct effects on final STN following residue return. In particular, the initial STN content both directly affected the changes in STN and was a transitional factor indirectly affecting changes in STN influenced by MAT, MAP and N fertilizer addition. More generally, land use, climatic attributes, the duration of residue return and the initial STN content are important aspects which should be given more consideration in the process of developing management strategies for returning residue.

A 4500-Year Tree-Ring Record of Extreme Climatic Events on the Yamal Peninsula

Based on the analysis of the frequency of anomalous anatomical structures in the wood of Siberian larch and Siberian spruce (frost rings, light rings, and false rings, as well as missing and narrow rings), we reconstructed a timeline of climatic extremes (summer frosts, sharp multiday decreases in air temperature during the growing season, and low average summer temperatures) in Yamal (Western Siberia) over the last 4500 years. In total, 229 years were determined to have experienced extreme events. The most significant temperature extremes were recorded in 2053, 1935, 1647, 1626, 1553, 1538, 1410, 1401, 982, 919, 883 BCE, 143, 404, 543, 640, 1209, 1440, 1453, 1466, 1481, 1601 and 1818 CE. These dates with extrema observed in Yamal corrobarated with tree ring data from other regions and revealed several coincidences. That is, in these years, the observed extremes appeared to have been on a global rather than a regional scale. Moreover, these dates coincided with traces of large volcanic eruptions found in ice cores from Greenland and Antarctica, dated to approximately the same years. Therefore, the cause of the extreme summer cooling on a global scale, in most cases, can be linked to large volcanic eruptions.

Effect of incident direction and droplet position on dynamic and heat transfer behaviors of droplet impacting on super-hydrophilic cylindrical surface

Abnormal impact of droplet with different incident directions and positions can be found in evaporator, desalinator and nuclear engineering etc. The researches devoted to droplet abnormal impingement on a super-hydrophilic cylindrical surface are limited. In this paper, a numerical study of individual droplet impacting on super-hydrophilic cylindrical heated surface was conducted by applying VOF method. The incident direction and position of droplet were characterized by the impact angle φ and horizontal offset δx, the effect of which on dynamic and heat transfer behaviors was analyzed. Results show that there is an anisotropic spread during droplet impingement. Compared to no-offset vertical impact, the peaks of liquid film thickness for impact with an impact angle or horizontal offset are not the same at two edges of liquid film along circumferential direction. Impact angle or horizontal offset leads to a reduced contact area, a lower average temperature of liquid film and smaller total droplet input heat flow. For φ from 0° to 75° and δx from 0 mm to 5 mm, the maximum total droplet input heat flow decreases by 42.1% and 27.6% respectively. The local heat flux shows apparent fluctuations along the circumferential direction, and the high heat flux region is concentrated at a lower position in the circumferential direction of the cylinder for a larger φ or δx due to the auxiliary effect of gravity.

Cycle of Potential Fishing Area of WPP-NRI 711 Year 2011-2020

This study discussed the cycle of potential fishing areas in WPP-NRI 711 based on the distribution of Sea Surface Temperature (SST) and distribution of chlorophyll-a concentration using MODIS Aqua satellite imagery. The distribution of Potential Fishing Areas (PFA) was determined based on the distribution of the thermal front which was processed using MGET (Marine Geospatial Ecology Tools) and chlorophyll-a. Determination of fluctuations and the emergence period of PFA for 10 years (2011-2020) is carried out using wavelets. The results showed that the average SST in WPP-NRI 711 was 29 °C. The highest average SST is 31 °C in May of the Transitional I Season, and the lowest average temperature is 27.9 °C in February of the West Monsoon Season. The average chlorophyll-a concentration was 0.6 mg/m3, the highest average chlorophyll-a concentration was 0.76 mg/m3 in December West Monsoon Season, and the lowest average was 0.53 mg/m3 in October Transitional II Season. The average PFA distribution area is 1.111 km2, the highest average area is 1.324 km2 in the West Monsoon Season, then the lowest area is 924 km2 in the Transitional II Season. Based on global spectrum and wavelet analysis, it is known that the period of the appearance of PFA is 3-6 months or Seasonal. then in the Northern Region segment of WPP-NRI 711, covering the Natuna Sea, the appearance of PFA is strongly influenced by Seasonal current movements. Meanwhile in the southern part, including the Karimata Strait, the emergence of PFA is strongly influenced by river runoff and changing Seasons.