Air Pollution and Heat Exposure Study in the Workplace in a Glass Manufacturing Unit in India

Air pollution in the workplace environment due to industrial operation have been found to cause serious occupational health hazard. Similarly, heat stress is still most neglected occupational hazard in the tropical and subtropical countries like India. The hot climate augments the heat exposure close to sources like furnaces. In this study an attempt is made to assess air pollution and heat exposure levels to workers in the workplace environment in glass manufacturing unit located in the State of Gujarat, India. Samples for workplace air quality were collected for SPM, SO₂, NO₂ and CO₂ at eight locations. Results of workplace air quality showed 8-hourly average concentrations of SPM: 165–9118 μg/m³, SO₂: 6–9 μg/m³ and NO₂: 5–42 μg/m³, which were below the threshold limit values of workplace environment. The level of CO₂ in workplace air of the plant was found to be in the range 827–2886 μg/m³, which was below TLV but much higher than the normal concentration for CO₂ in the air (585 mg/m³). Indoor heat exposure was studied near the furnace and at various locations in an industrial complex for glass manufacturing. The heat exposure parameters including the air temperature, the wet bulb temperature, and the globe parameters were measured. The Wet Bulb Globe Temperature (WBGT), an indicator of heat, exceeded ACGIH TLVs limits most of the time at all the locations in workplace areas. The recommended duration of work and rest have also been estimated.     

方轧件在椭圆孔型中轧制温度场的三维有限元分析

应用MARC/autoforge有限元软件对方轧件在椭圆孔型中的轧制温度场进行了热力耦合模拟.研究了模拟过程中的传热边界条件,分析了轧制前和轧制过程中轧件中温度场的分布和变化规律.模拟计算结果和实验结果的比较说明二者基本是相符的.     

辛基酚的体内类雌激素活性评价

利用体内大鼠子宫增重试验检测辛基酚（OP）的类雌激素活性，并对其观测终点及影响因素进行了初步研究。结果显示，OP经大鼠体内染毒，可引起大鼠子宫湿重、子宫内皮细胞厚度、子宫腺数量明显增加，具有明显的类雌激素活性。三条染毒途径检测敏感度腹腔染毒＞经皮下染毒＞经灌胃染毒。     

在降雨量极少的条件下日本琵琶湖的环境因子的分布(英文)

琵琶湖是日本第一大淡水湖,20世纪60年代以来,由于经济的发展,湖水水质逐步变坏。1977年湖的北部出现赤潮,1983年湖的南部出现了湖泊富营养化的产物微囊藻。多年来,在深水区湖水温度分层情况下,叶绿素a或浮游植物主要分布在湖的表层(Tezuka,1984)。但在1994年夏季,降雨量极少的情况下,在深水区叶绿素a或浮游植物主要分布在温跃层附近,这种现象在琵琶湖是罕见的(Nakanishi,1995)。最近,琵琶湖北湖的藻类爆发显著增加了溶氧的消耗,导致了湖底层溶氧的减少。如果湖底层溶氧持续减少,底泥储存的磷就会释放到湖水中,从而加快湖泊富营养化的进程。本文分析了琵琶湖南北10个点1994年4月至1995年3月每月1次的常规观测资料,深入剖析了全湖物理化学参数的时空分布,不仅发现叶绿素的峰值在湖水温度分层时出现在温跃层的上部,而且湖底边界层同时出现了低溶氧和高浊度的现象。分析认为绿素a和溶氧、浊度的对应关系表明温跃层是一光合成活跃的区间。     

A reflection on four impactful Ambio papers: The biotic perspective: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Climate change impacts

Climate change represents one of the most pressing societal and scientific challenges of our time. While much of the current research on climate change focuses on future prediction, some of the strongest signals of warming can already be seen in Arctic and alpine areas, where temperatures are rising faster than the global average, and in the oceans, where the combination of rising temperatures and acidification due to increased CO₂ concentrations has had catastrophic consequences for sensitive marine organisms inhabiting coral reefs. The scientific papers highlighted as part of this anniversary issue represent some of the most impactful advances in our understanding of the consequences of anthropogenic climate change. Here, we reflect on the legacy of these papers from the biotic perspective.     

高温(70℃)玉米秸秆水解液产氢行为及群落结构

考察了高温条件下(70℃)牛粪堆肥、土壤、厌氧污泥、腐烂秸秆种接种物利用玉米秸秆水解液的产氢行为。结果表明:牛粪堆肥接种时达到最大的产气量(1355.7mL/L)和氢气产量(608.4mL/L),随后依次为腐烂秸秆、厌氧污泥和土壤。修改的Gompertz方程可以较好描述产氢量随时间变化趋势(R2>0.99)。牛粪堆肥接种时达到最大的产氢潜力(676.0mL/L),而土壤接种时的迟滞时间最小(9.8h)。DGGE图谱显示:不同接种物对应不同的微生物群落结构。Bacillus thermozeamaize,Enterobacter sp.JDM-19和Thermoanaerobacterium polysaccharolyticum strain,KMTHCJT和可能分别是牛粪堆肥,厌氧污泥和腐烂秸秆接种条件下的关键产氢微生物。     

Warm forming die design,Part II: Parting surface temperature response characterization of a novel thermal finite element modeling code

The majority of the research activities in the area of warm forming are concentrated on demonstrating or simulating the improved formability associated with forming lightweight materials such as aluminum alloys at elevated temperatures. However, the ability to design the proper thermal management system within the forming tool is a critical aspect to delivering this technology as a viable, stable production alternative to traditional stamping. This work begins to address the thermal stability issues of this process by examining the impact of process cycle time on the parting surface temperature response. Cycle times of 10, 15, 30, and 300 s were evaluated using a reciprocating surface and a self-heated experimental block of 1020 steel fitted with resistance cartridge heaters. The presented results indicate that cycle time does not significantly impact the steady-state temperature response at the parting surface for a well-insulated die that has proper thermal management. Parting surface experimental results were compared to values obtained numerically and through the use of the novel thermal finite element analysis software PASSAGE/Forming^®.     

实验室条件下温度升高对水体叶绿素a的影响研究

以23℃为基础,按2℃温差设置温度梯度,最高温度组为29℃。每隔10d取样一次,进行叶绿素α浓度的测定。结果显示温度低于25℃时,增温有助于藻类生物量的提高,而温度超过25℃时,增温限制了藻类生物量的提高。水体温度量对浮游植物生物的影响程度与增温幅度和培养时间有关。Pearson相关性分析结果显示:温度与叶绿素a浓度相关性显著(P0.05),叶绿素a浓度与培养时间呈极显著正相关(P0.01)。     

Characterization of the toxic effects of cadmium and 3.5-dichlorophenol on nitrifying activity and mortality in biologically activated sludge systems—effect of low temperature

Background, aims, and scope  Sometimes, urban wastewaters convey a more or less significant part of toxic products from industries or the craft industry. Nitrifying activity can be affected by these substances, implying higher ammonia concentrations in the outlet effluent and contributing to toxicity for the aquatic environment. Moreover, the more stringently treated wastewater standards now require a reliable treatment for nitrogen. One of the key issues is the identification of the inhibition behavior of nitrifying bacteria facing a toxic substance. This new understanding could then finally be integrated into models in order to represent and to optimize wastewater treatment plants (WWTP) operation in cases involving ‘toxic scenarios’. Materials and methods  The toxic substances studied in this work, cadmium and 3.5-dichlorophenol (3.5-DCP), are representative of chemical substances commonly found in municipal sewage and industrial effluents and symbolize two different contaminant groups. The effects of Cd and 3.5-DCP on nitrification kinetics have been investigated using respirometry techniques. Results  IC50 values determination gives concentrations of 3.1 mg/L for 3.5-DCP and 45.8 mg/L for Cd at 21 ± 1°C. The variation to low temperature seems to have no real effect on IC50 for DCP, but induces a decrease of cadmium IC50 to 27.5 mg/L at 14°C. Finally, specific respirometric tests have been carried out in order to determine the potential effect of these toxic substances on the nitrifying decay rate b _a . No significant effect has been noticed for Cd, whereas the presence of 3.5-DCP (at IC50 concentration) induced a dramatic increase of b _a at 20°C. The same behavior has been confirmed by experiments performed in winter periods with a sludge temperature around 12°C. Discussion  The target substances have different modes of action on activity and mortality, notably due to the abilities of the contaminant to be precipitated, accumulated, or even to be progressively degraded. Studies realized at low temperature confirmed this assumption, and put in evidence the effect of temperature on toxic substances capable of being biosorbed. However, the change in the sludge sample characteristics can be pointed out as a problem in the investigation of the temperature effect on nitrification inhibition, as biosorption, bioaccumulation, and predation are directly linked to the sludge characteristics (VSS concentration, temperature) and the plant operating conditions (loading rates, sludge age, etc.). Conclusions  This work brings new understandings concerning the action mode of these specific contaminants on nitrifying bacteria and, in particular, on the role of temperature. The experiments lead to the determination of the IC50 values for both toxic substances on biological nitrification. The inhibition mechanisms of Cd and 3.5-DCP on nitrifying activity have been simply represented by a non-competitive inhibition model. Recommendations and perspectives  Other experiments carried out in a continuous lab-scale pilot plant should be done with a proper control of the operating conditions and of the sludge characteristics in order to better understand the mechanisms of nitrification inhibition for each contaminant. Finally, these first results show that toxic substances can have an effect on the growth rate but also on the decay rate, depending on the characteristics of the toxic substance and the sludge. This eventual double effect would imply different strategies of WWTP operation according to the behavior of the contaminant on the bacteria.     

The influence of Chinese population policy change on resources and the environment

Universal two-child policy has been implemented since the end of 2015 in China. This policy is anticipated to bring a significant increase in the total population, with profound influences on the resources and environment in the future. This paper analyzes the changing dynamics of urban and rural population, and forecasts urban and rural population from 2016 to 2030 at national and provincial scale using a double log linear regression model. Drawing upon the results of these two predictions, the impact of the population policy change on Chinese resources consumption and environmental pollution are predicted quantitatively. Given the future total population maintains current levels on resources consumption and environmental emission, the additional demand of resources and environment demand for the new population is forecasted and compared against the capacity on supply side. The findings are as follows: after implementing the universal two-child policy, China’s grain, energy consumption, domestic water demand, and pollutant emissions are projected to increase at different rates across provinces. To meet the needs arising from future population growth, food and energy self-sufficiency rate will be significantly reduced in the future, while relying more on imports. Stability of the water supply needs to be improved, especially in Beijing, Henan, Jiangsu, Qinghai, and Sichuan where the gap in future domestic water demand is comparatively larger. Environmental protection and associated governing capability are in urgent need of upgrade not least due to the increasing pressure of pollution.