Comparison of calculated data for the flammability and the oxidation potential according to ISO 10156 with experimentally determined values

The classification of flammable gas mixtures is based on either testing or calculation methods proposed by the revised international standard ISO 10156. This standard is used for classification of physical hazards in Chapters 2.2 and 2.4 of the UN Globally Harmonized System of Classification and Labelling of Chemicals (GHS) and in the UN Recommendations on Transport of Dangerous Goods (TDG). The test methods of flammability and oxidizing potential in this standard were developed by BAM. Earlier versions of this standard are not based on triangular diagrams and on the reference combustible substance “ethane”. The old material characteristics, especially in case of oxidizing potential, are based mostly on practical experience without any quantifiable test results. First time it is possible to compare experimental results from the CHEMSAFE database with the newly developed calculation method. In this paper the basic principles of the calculation methods are presented and the methods are validated by examples. A comparison of experimental flammability data with classification results gained by the calculation methods of ISO 10156 is demonstrated.     

房采采空区失稳危险性评价

由房采采空区失稳引发的灾害已成为危害矿山及社会安全的重要因素之一。为了对房采采空区失稳进行危险性评价,在分析影响房采采空区失稳危险状态的自然地质条件因素与指数W1和开采技术条件因素与指数W2的基础上,采用综合指数法对房采采空区危险源进行分级研究,确定房采采空区失稳危险状态等级评定的综合指数W。将房采采空区失稳危险源分为4级,即Ⅰ级危险源(特大危险性,W≥0.8);Ⅱ级危险源(重大危险性,0.6≤W<0.8);Ⅲ级危险源(较大危险性,0.3≤W<0.6)和Ⅳ级危险源(一般危险性,W<0.3)。结合实例,对陕西某矿区房采采空区失稳危险性进行分级,并提出预防性措施。     

Laminar jet modelling for hazardous area classification

A previous article dealt with turbulent jet flow modelling with the aim at developing a method for estimating the size of explosive clouds following a high Reynolds number release, within hazardous area classification scheme. The results have demonstrated that the standard EN 60079-10 (2009) largely overestimates the real size of clouds resulting from a piping or a vessel leak. On the other hand, laminar jets are possible also at moderately high Reynolds numbers; furthermore, a reduced momentum, typical of laminar jets, is often assumed in QRA studies, as a conservative assumption, due to the expected lower air entrainment and to the corresponding larger size of the flammable cloud volume. These considerations have suggested the suitability to extend the previous analysis also to laminar regime, taking into account the effect of density and viscosity differences between air and flammable gas.     

一种系统化的生产安全事故分级新方法研究

为了强化《生产安全事故报告和调查处理条例》(493号令)对事故管理及其影响评价的重要作用。笔者在论证了关于提出事故分级新方法的必要性后,在前人已有研究成果的基础上,结合生产安全事故特点,初步提出了一种基于"人员伤亡、财产损失、社会影响和环境污染"四个指标的系统化事故分级新方法。该事故分级理念及方法能更好地切合生产安全事故定义,对新时期下事故分级理念中事故影响多样性内涵的引入是一种积极和有效的探索,具有一定意义。     

Resource abundance and financial development: Evidence from China

In this paper, we extend the debate on the resource curse by focusing on a new mechanism. Theoretically, resource abundance may have a negative influence on financial development by impacting trade openness, the demand for financial reforms, social capital accumulation and productive investments. Using provincial panel data of China, the empirical analysis confirms such a negative link between mineral resource abundance and financial development. The resource-rich regions tend to have a slower pace of financial development than resource-poor ones. Since the positive relationship between financial development and long-run growth is also confirmed by the analysis, our findings suggest that financial development constitutes an important mechanism through which resource abundance can impact economic performance.     

Aggregates in England—Economic contribution and environmental cost of indigenous supply

Aggregates represent one of the largest material flows in the UK economy; however, the importance of these minerals in underpinning economic activity is frequently not recognised. Features such as the spatial imbalance between resources and demand centres, exacerbated by changes in demographics and public perception, are placing increased pressure on the planning system to maintain supply. This paper sets out the direct and indirect economic contributions made by the indigenous aggregates industry to the English economy through Gross Value Added and employment sustained. It describes the key role of aggregates in construction activities, assesses the links between infrastructure development and economic growth. In 2005, aggregates extraction directly contributed £810 million of Gross Value Added to the English economy. Primary aggregates are, however, extracted at a cost to the environment and this cost, based on amenity value reduction, is estimated by updating previously published contingent valuation data. Estimates for the costs associated with carbon dioxide emissions are derived from values published by the European Union and, separately, by the UK Government. These two elements combined result in an environmental cost of indigenous extraction of £445 million in 2005. Additionally, an examination of the potential for a significant increase in the level of aggregate imports into England is made and the consequences assessed. This includes an evaluation of shipping costs and port capacity, and concludes that there are significant barriers to any substantial increase in the level of aggregate imports into England. As a consequence, indigenous supply is likely to predominate into the foreseeable future.     

The impact of commodity price risk management on the profits of a company

It is well recognized that for the producing companies hedging the commodity price using financial products like forwards or futures has become an important part of the company's production process. But apart from the direct impacts of hedging on the production and hedging costs the use of financial products affects the financing of the company: hedging the volatile commodity prices leads to a reduction of the risk premium the company has to pay for its debt capital, since hedging contributes to more confidence of the investors in the redemption of the debt. In this paper we therefore analyze this dependency of hedging and financing and derive optimal hedging extents for companies in different market situations based on a long-term model. By hedging the commodity price, companies can realize a surplus in profits. Thereby, the optimal hedging extent for a monopolist is often up to 100%, whereas for companies in a polypolistic market the optimum is always less than 100%. These results are illustrated by examples for a producing company.     

A Methodology for Space-Time Classification of Groundwater Quality

Safeguarding groundwater from civil, agricultural and industrial contamination is matter of great interest in water resource management. During recent years, much legislation has been produced stating the importance of groundwater as a source for drinking water supplies, underlining its vulnerability and defining the required quality standards. Thus, schematic tools, able to characterise the quality and quantity of groundwater systems, are of very great interest in any territorial planning and/or water resource management activity.This paper proposes a groundwater quality classification method which has been applied to a real aquifer, starting from several studies published by the Italian National Hydrogeologic Catastrophe Defence Group (GNDCI).The methodology is based on the concentration values of several parameters used as indexes of the natural hydro-chemical water condition and of potential man-induced modifications of groundwater quality. The resulting maps, although representative of the quality, do not include any information on its evolution in time. In this paper, this “stationary” classification method has been improved by crossing the quality classes with three indexes of temporal behaviour during recent years. It was then applied to data from monitoring campaigns, performed in spring and autumn, from 1990 to 1996, in the plain of Modena aquifer (central Italy). The results are reported in the form of space-time classification table and maps.     

Relevance of Hydro-Climatic Change Projection and Monitoring for Assessment of Water Cycle Changes in the Arctic

Rapid changes to the Arctic hydrological cycle challenge both our process understanding and our ability to find appropriate adaptation strategies. We have investigated the relevance and accuracy development of climate change projections for assessment of water cycle changes in major Arctic drainage basins. Results show relatively good agreement of climate model projections with observed temperature changes, but high model inaccuracy relative to available observation data for precipitation changes. Direct observations further show systematically larger (smaller) runoff than precipitation increases (decreases). This result is partly attributable to uncertainties and systematic bias in precipitation observations, but still indicates that some of the observed increase in Arctic river runoff is due to water storage changes, for example melting permafrost and/or groundwater storage changes, within the drainage basins. Such causes of runoff change affect sea level, in addition to ocean salinity, and inland water resources, ecosystems, and infrastructure. Process-based hydrological modeling and observations, which can resolve changes in evapotranspiration, and groundwater and permafrost storage at and below river basin scales, are needed in order to accurately interpret and translate climate-driven precipitation changes to changes in freshwater cycling and runoff. In contrast to this need, our results show that the density of Arctic runoff monitoring has become increasingly biased and less relevant by decreasing most and being lowest in river basins with the largest expected climatic changes.     

硫酸庆大霉素废水处理的研究

抗生素工业废水具有成分复杂、污染物浓度高、色度大、生物毒性等特点,比较难于治理。硫酸庆大霉素是常用的抗生素之一,其废水除具备上述特点外,还存在pH值波动范围大、水质、水量不均、SO42-浓度高等问题。本研究采用交换母液絮凝过滤-水解酸化-IC-SBR-MBR工艺处理含有硫酸庆大霉素的废水,在进水COD浓度6 000 mg/L～10 000 mg/L、SS浓度2 000 mg/L～3 000 mg/L的条件下,通过优化交换母液絮凝过滤药剂用量、水解酸化池废水停留时间、IC池的容积负荷、SBR池、MBR的污泥负荷等处理工艺,使出水水质能够达到COD 60 mg/L、BOD5 10 mg/L、NH3-N 10 mg/L。