Risk and mitigation of self-heating and spontaneous combustion in underground coal storage

While the self-heating and spontaneous combustion of coal is a known challenge at coal mines and storage sites, there are known methods for mitigating this challenge for typical open stockpile storage. However, closing the storage will reduce access for corrective action, and it is then important to manage the storage and its transport system with added attention without unduly adding cost or hindering availability. This paper aims to discuss the risk, prevention and extinguishing of fires in closed coal storage facilities, particularly in light of the experience with the Salmisaari underground rock storage facility in Finland. The observed autoignition events have indicated an array of contributing factors, some of which are unique to underground silo storage facilities. On the other hand, many features of the storage facilities can be compared with other extant closed storage systems. The factors affecting fire risk are described and the associated fault and event trees are outlined for autoignition at underground storage. Drawing upon the experiences with past events of self-heating and spontaneous combustion, recommendations are given on cost-effective preventive, corrective and other mitigating action for minimising fire risk and promoting storage availability.     

Thermal manikin measurements--exact or not?

According to the European prestandard ENV 342:1998, the thermal insulation of cold-protective clothing is measured with a thermal manikin. Systematic studies on the reproducibility of the values, measured with different types of clothing on the commonly used standing and walking manikins, have not been reported in the literature. Over 300 measurements were done in 8 different European laboratories. The reproducibility of the thermal insulation test results was good. The coefficient of variation was lower than 8%. The measured clothing should fit the manikin precisely, because poorly fitting clothing gave an error in the results. The correlation between parallel and serial insulation values was excellent and parallel values were about 20% lower than serial ones. The influence of ambient conditions was critical only in the case of air velocity. The reproducibility of thermal insulation test results in a single laboratory was good, and the variation was lower than 3%.     

Sustainable Food Consumption: Exploring the Consumer “Attitude – Behavioral Intention” Gap

Although public interest in sustainability increases and consumer attitudes are mainly positive, behavioral patterns are not univocally consistent with attitudes. This study investigates the presumed gap between favorable attitude towards sustainable behavior and behavioral intention to purchase sustainable food products. The impact of involvement, perceived availability, certainty, perceived consumer effectiveness (PCE), values, and social norms on consumers’ attitudes and intentions towards sustainable food products is analyzed. The empirical research builds on a survey with a sample of 456 young consumers, using a questionnaire and an experimental design with manipulation of key constructs through showing advertisements for sustainable dairy. Involvement with sustainability, certainty, and PCE have a significant positive impact on attitude towards buying sustainable dairy products, which in turn correlates strongly with intention to buy. Low perceived availability of sustainable products explains why intentions to buy remain low, although attitudes might be positive. On the reverse side, experiencing social pressure from peers (social norm) explains intentions to buy, despite rather negative personal attitudes. This study shows that more sustainable and ethical food consumption can be stimulated through raising involvement, PCE, certainty, social norms, and perceived availability.     

Effect of Climate Warming and Drought on Urban Stream Temperatures in a Semiarid,Seasonal System

Stream temperatures are key indicators for aquatic ecosystem health, and are of particular concern in highly seasonal, water‐limited regions such as California that provide sensitive habitat for cold‐water species. Yet in many of these critical regions, the combined impacts of a warmer climate and urbanization on stream temperatures have not been systematically studied. We examined recent changes in air temperature and precipitation, including during the recent extreme drought, and compared the stream temperature responses of urban and nonurban streams under four climatic conditions and the 2008–2018 period. Metrics included changes in the magnitude and timing of stream temperatures, and the frequency of exceedance of ecologically relevant thresholds. Our results showed that minimum and average daily air temperatures in the region have increased by >1°C over the past 20 years, warming both urban and nonurban streams. Stream temperatures under drought warmed most (1°C–2°C) in late spring and early fall, effectively lengthening the summer warm season. The frequency of occurrence of periods of elevated stream temperatures was greater during warm climate conditions for both urban and nonurban streams, but urban streams experienced extreme conditions 1.5–2 times as often as nonurban streams. Our findings underscore that systematically monitoring and managing urban stream temperatures under climate change and drought is critically needed for seasonal, water‐limited urban systems.     

Nachhaltigkeit in der Pflanzenproduktion

The purpose of part II is to develop and to discuss a methodological approach for the practical implementation of sustainable crop production. In part I the term “sustainable crop production” has been defined and explained. Based on this definition the approach presented here entails several steps starting with the identification of the whole range of crop management measures and the emissions and other releases associated with them. Through an impact pathway assessment these releases are traced from their point of origin, the farm or production level, to their end points, namely agroecosystems and adjacent ecosystems. At the ecosystem level condition-indicators, which describe the condition of the ecosystems affected by agricultural crop production measures, need to be selected. For these condition-indicators threshold values (i.e. maximally tolerable values) have to be determined. These should not be exceeded if irreversible changes in the respective ecosystems and ecosystem compartments are to be avoided. By tracing the maximally tolerable values back along their impact pathway, they are transposed to the level of crop production. At the farm level they prescribe a framework within which agricultural crop production must remain to prevent irreversible changes in the affected ecosystems. The framework consists of production indicators and their respective threshold values (i.e. critical uses of farm inputs), which have to be adhered to in order to ensure sustainable crop production.     

Effects of organic matter and ageing on the bioaccessibility of arsenic

Arsenic-contaminated soils may pose a risk to human health. Redevelopment of contaminated sites may involve amending soils with organic matter, which potentially increases arsenic bioaccessibility. The effects of ageing on arsenic-contaminated soils mixed with peat moss were evaluated in a simulated ageing period representing two years, during which arsenic bioaccessibility was periodically measured. Significant increases (p = 0.032) in bioaccessibility were observed for 15 of 31 samples tested, particularly in comparison with samples originally containing >30% bioaccessible arsenic in soils naturally rich in organic matter (>25%). Samples where percent arsenic bioaccessibility was unchanged with age were generally poor in organic matter (average 7.7%) and contained both arsenopyrite and pentavalent arsenic forms that remained unaffected by the organic matter amendments. Results suggest that the addition of organic matter may lead to increases in arsenic bioaccessibility, which warrants caution in the evaluation of risks associated with redevelopment of arsenic-contaminated land.