Comparison of PM2.5 in Seoul, Korea Estimated from the Various Ground-Based and Satellite AOD

Based on multiple linear regression (MLR) models, we estimated the PM2.5 at Seoul using a number of aerosol optical depth (AOD) values obtained from ground-based and satellite remote sensing observations. To construct the MLR model, we consider various parameters related to the ambient meteorology and air quality. In general, all AOD values resulted in the high quality of PM2.5 estimation through the MLR method: mostly correlation coefficients >~0.8. Among various polar-orbit satellite AODs, AOD values from the MODIS measurement contribute to better PM2.5 estimation. We also found that the quality of estimated PM2.5 shows some seasonal variation; the estimated PM2.5 values consistently have the highest correlation with in situ PM2.5 in autumn, but are not well established in winter, probably due to the difficulty of AOD retrieval in the winter condition. MLR modeling using spectral AOD values from the ground-based measurements revealed that the accuracy of PM2.5 estimation does not depend on the selected wavelength. Although all AOD values used in this study resulted in a reasonable accuracy range of PM2.5 estimation, our analyses of the difference in estimated PM2.5 reveal the importance of utilizing the proper AOD for the best quality of PM2.5 estimation.

Winter is coming: harsh environments limit independent reproduction of cooperative-breeding queens in a socially polymorphic ant

Cooperative breeding animals frequently inhabit harsh environments. It is widely accepted that harsh environments hinder independent reproduction, and this constraint maintains individuals in family groups. Yet the assumption that harsh ecological conditions reduce the success of members of cooperative breeding groups when breeding independently has not been experimentally tested. We addressed this shortcoming using the socially polymorphic Alpine silver ant, Formica selysi . This species has single-queen (independent breeders) and multiple-queen (cooperative breeders) colonies coexisting within populations. We placed newly mated queens emerging from each type of colony to breed alone in either a harsh or mild winter condition and recorded their brood production and survival. Queens emerging from single-queen colonies were unaffected by the winter condition and were more successful at founding a nest independently than queens from multiple-queen colonies. By contrast, queens from multiple-queen colonies had higher mortality after a harsh than after a mild winter. These results support the long-held assumption that harsh environments constrain independent reproduction of members of cooperative breeding groups.

Energy savings potential from prismatic glass structure

The simulation analysis of the potential energy savings from the prismatic glass structure has been provided. The two conventional triple glazings and two proposed triple glazings with prismatic glass have been experimentally tested to obtain the realistic angular selective optical properties. The experimental results have been compared with conventional triple glazing with clear glass panes and triple glazing with solar control pane applied. The comparison indicated high potential advantages of triple glazing with prismatic glass structures (especially for reverse symmetrical prism): low transmittance for high solar altitude–summer condition, high transmittance for low solar altitude–winter condition. The obtained transmittance characteristics were used as input data for the annual simulation of a typical office in the Czech Republic. The simulation has been performed in TRNSYS and TRNBuild software. The gathered results confirmed, that prismatic glass structure can bring energy savings for both cooling and heating energy demands.

Thermal Modeling and Performance Analysis of a Hybrid Photovoltaic/Thermal System Under Combined Surface Water Cooling in Winter Season: An Experimental Approach

In this paper, thermal modeling of a hybrid photovoltaic/thermal (PV/T) system has been developed under combined (front and back) water surface cooling. An analytical expression has been derived for solar cell temperature (Tcs), back surface temperature (Tbs), and overall efficiency (ηOE) of the hybrid PV/T system for the winter condition. Statistical analysis has been performed in the cold climate of MNIT, Jaipur (India), for determining performance parameters of the hybrid PV/T system. An experimental validation has been carried out for the developed thermal model, and fair agreement between the numerical and experimental observations has been observed. We have also calculated the electrical (ηele), thermal (ηth), and overall efficiency (ηOE) as 18.83%, 43.8%, and 64.56%, respectively, and output power as 57.39 mW in the winter condition. We have also noticed that better performance is given by 1.5 LPM out of the four (1, 1.5, 2, and 2.5 LPM) flow rates.

Efficacy of fall-applied residual herbicides on weedy rice control in rice (Oryza sativa L.)

Field experiments were initiated near Colt, AR, in the fall of 2016 and continued through the summer of 2018 to evaluate rice tolerance and weedy (or red) rice control after fall-applied very-long-chain fatty acid (VLCFA)-inhibiting herbicides. A split-plot design was used for the experiment, with the whole-plot factor being winter condition (flooded or non-flooded) and the split-plot factors being herbicide and rate. Herbicide treatments included acetochlor, dimethenamid-P, pethoxamid, pyroxasulfone, andS-metolachlor applied at 1,050, 525, 420, 205, and 1,070 g ai ha−1and at 2,100, 1,050, 840, 410, and 2,140 g ha−1for low rates and high rates, respectively. Herbicides were applied in the fall, then ‘CL172’ rice was drill seeded in the spring of the following calendar year. Weedy rice control differed between years, but acetochlor and pyroxasulfone consistently provided the greatest levels of control across rates and flood conditions. Consequently, herbicides that best controlled weedy rice also caused the greatest injury to cultivated rice. Rice injury did not exceed 13% regardless of herbicide treatment at 3 wk after planting (WAP). However, the high rate of pyroxasulfone caused 20% rice injury at 5 WAP in 2018. Although it was expected that winter condition may affect residual activity of the VLCFA-inhibiting herbicides, herbicide selection and application rate both had much greater effects on rice injury and on weedy rice control. Based on these results, rice injury would be minimal or nonexistent after fall applications of the tested VLCFA inhibitors, and intermediate levels of weedy rice control may be achieved. The implementation of VLCFA-inhibiting herbicides in rice production systems would offer a novel herbicide site of action and offer a degree of selective control of weedy rice.

Assessment of The Effects of Winter Condition on Sweet Sorghum Yield and Sugar Content

Sweet sorghum is an important crop which is produced for food, energy and feed (Almodares and Hadi, 2009). The crop prefers warm moist soil for germination and emergence. However, it would be more beneficial if it can be grown in different seasons. A field experiment was carried to evaluate sixteen sweet sorghum genotypes [Sorghum bicolor (L.) Moench] under winter conditions in order to assess the possibility of producing the crop throughout the year since the crop consumes less water and has a short life cycle when compared with sugarcane. The genotypes we recollected from different areas of Sudan. The experiment was planted using a Randomized Complete Block Design with three replications. There were significant differences among genotypes with respect to the number of days to germination, plant height, number of leaves per plant, chlorophyll content, stem diameter, head weight, shoot fresh weight, head to shoot ratio, brix value, juice weight and number of days to maturity. A highly positive correlation (0.92) was observed between juice and shoot weight, and there was a negative correlation (-0.14) between brix value and head weight. The genotypes showed high variability in all mentioned parameters, hence, could be useful genetic resources for breeding winter adaptation.