Total Organic Carbon,an Important Tool in an Holistic Approach to Hydrocarbon Source Fingerprinting

The identification and allocation of multiple hydrocarbon sources in marine sediments is best achieved using an holistic approach. Total organic carbon (TOC) is one important tool that can constrain the contributions of specific sources and rule out incorrect source allocations in cases where inputs are dominated by fossil organic carbon. In a study of the benthic sediments from Prince William Sound (PWS) and the Gulf of Alaska (GOA), we find excellent agreement between measured TOC and TOC calculated from hydrocarbon fingerprint matches of polycyclic aromatic hydrocarbons (PAH) and chemical biomarkers. Confirmation by two such independent source indicators (TOC and fingerprint matches) provides evidence that source allocations determined by the fingerprint matches are robust and that the major TOC sources have been correctly identified. Fingerprint matches quantify the hydrocarbon contributions of various sources to the benthic sediments and the degree of hydrocarbon winnowing by waves and currents. TOC contents are then calculated using source allocation results from fingerprint matches and the TOCs of contributing sources. Comparisons of the actual sediment TOC values and those calculated from source allocation support our earlier published findings (Boehm et al ., 2001) that the natural petrogenic hydrocarbon background in sediments in this area comes from eroding Tertiary shales and associated oil seeps along the northern GOA coast and exclude thermally mature area coals from being important contributors to the PWS background due to their high TOC content.     

基于文本挖掘的管制运行风险主题分析*

为充分挖掘管制运行风险信息和隐藏规律,实现数据驱动的风险管理。以某管制单位2004—2019年共269条管制原因不安全事件数据为挖掘语料,在考虑上下文语义的基础上,运用潜在狄利克雷分配（LDA）主题模型挖掘管制运行风险主题及关键词,使用Word2Vec挖掘主题之间、关键词之间的关联关系,运用社会网络分析软件UCINET、可视化工具NETDRAW构建语义网络将关联关系进行可视化并进行网络分析。结果表明:LDA主题模型可以通过运行数据实现对管制运行风险的高效提取和深层挖掘,挖掘到管制人为因素、特情处置、地空配合、班组资源管理、组织管理、运行环境、管制指挥共7个主题,其中管制人为因素主题是核心主题,与其他主题都具有较强的相互关联;Word2Vec和语义网络相结合能够更准确地挖掘风险之间的关系,确定主题的重要度排序,识别关键风险。     

Cities vs. agriculture: A review of intersectoral water re-allocation

Water demand management, or making better use of the water we have — as opposed to augmenting supply — is increasingly proposed as a way of mitigating water-scarcity problems. Moving water away from agriculture to uses with higher economic value is one of the main measures widely seen as desirable. Sectoral "allocation stress" is seen as resulting from the disproportionate share, and inefficient use of water in the agricultural sector. This apparent misallocation is often attributed to the failure of government to allocate water rationally.
This paper revisits this commonly-accepted wisdom and examines the nature of urban water scarcity, showing the importance of economic and political factors, shaped by incentives to decision-makers, and sometimes compounded by climatic conditions. It shows that cities' growth is not generally constrained by competition with agriculture. In general, rather than using a narrow financial criterion, cities select options that go along the "path of least resistance," whereby economic, social and political costs are considered in conjunction. The question of allocation stress is thus reframed into an inquiry of how transfers effectively occur and can be made more effective.     

Safety investment optimization in process industry: A risk-based approach

Process plant safety is a critical indicator of organizational performance. Adequate investment into safety practices to avoid future accident cost is therefore a beneficial strategy. The current approach to such investments in the process industry is driven largely by simple risk-based heuristics, insurance market premiums, organizational culture and management judgment. There is, however, an absence of an overarching methodology to assist such an effort. Therefore, there is a need for developing a robust decision-making framework for enabling systematic and optimal allocation of financial resources across all significant risk elements within a process plant.The present work proposes a safety investment optimization (SIO) framework for a typical process plant. Such an optimization approach targets maximal reduction of risk values across all potential hazards within the constraint of a given safety investment budget at the incipient stage of establishing a plant such that it saves future cost to company by reducing the risk from accidents. At the same time the framework takes into account the need to comply with the regulatory requirements imposed by the government. Additionally, access to insurance market as a strategy to transfer risk is also integrated. Finally, the residual risks are managed through investments in selective safeguards while ensuring that the benefits over-weigh the cost of such an exercise. For illustrating the application of the framework, a representative process plant with a select number of risk scenarios is chosen and all steps suggested by the framework are demonstrated quantitatively. It is anticipated that the proposed SIO framework will help optimal resource allocation for managing the risks implicit in a typical process plant.     

环境空气质量改善导向的财政资金分配模型与实施机制

"十三五"时期改进环境空气质量是首要任务,如何充分发挥财政资金对地方环境质量改善的引导和激励功能。文章提出了基于环境空气质量导向的财政激励资金分配模型和实施机制,并以2014~2015年的城市PM监测数据2.5进行了案例分析,结果表明该分配模型和实施机制具有科学性和可操作性,可以为建立环境空气质量导向的财政机制提供管理技术支撑。     

河口人工湿地植物配置与景观建设维护研究——以沈阳市辉山明渠河口湿地为例

以沈阳市辉山明渠入浑河河口湿地为研究对象,通过植物适应性分析、湿地植物选择、湿地植物优化配置、景观合理性配置等综合调控措施,使辉山明渠入浑河水质得到有效改善、湿地生物多样性得到恢复、人工湿地生态系统稳定性增强、形成独具特色的河口湿地景观。     

Design of Mass Exchange Network and Effluent Distribution System for effective water management

The environmental impact of industrial wastewater and higher cost of fresh water are the serious challenges faced by the process industries. It has led to the development of many new techniques to minimize fresh water consumption. Of the many approaches, which have been developed, the Water Source Diagram (WSD) is a flexible and dynamic alternative for the generation of different scenarios for the management of water networks with reduction in total consumption. In the present study WSD concept was coupled with water mains concept to mains simplify the piping network and reduce the cost. A new procedure was developed for integrating the effluent treatment processes to evolve Effluent Treatment Network. Example from literature having multi contaminants was considered. This simple procedure involving hand calculations will be a useful tool for process engineers to design water and effluent treatment networks. Also the WSD and ETN were combined to form an evolutionary WAMEN (Water Allocation and Mass Exchange Network) and the proposed WAMEN aims for minimum fresh water consumption.     

Influence of allocation methods on the environmental performance of biorefinery products—A case study

Life Cycle Assessment (LCA) methodology is the prevailing framework for estimating the environmental performances of a product/service. The application of LCA frequently requires practitioners to address allocation issues, especially when a large number of co-products are produced. The choice of an allocation approach for multifunctional processes is among the most debated methodological aspects in the LCA community, given its potentially large influence on final outcomes. Despite numerous efforts, a uniform consensus on the best allocation practice is still lacking and no single method appears as the most suitable for all situations.The aim of this paper is to assess how different allocation methods affect the environmental performances of a lignocellulosic biorefinery. Biorefinery systems represent a good example of a multifunctional process, since they co-produce multiple energy and material products. The following allocation procedures are applied: system expansion (also named substitution method), partitioning method according to different features of co-products (mass, energy, exergy and economic value), and hybrid approach (given by a combination of the previous ones). In order to enhance the clarity of the discussion, a mathematical notation for these allocation procedures is adopted, and analytical interrelations are investigated. Results show the influence of the allocation methods on the environmental impacts assigned to the individual products, both on a unit and annual flow basis.     

MTBE Transport Screening Analysis in Vadose Zone Risk and Liability Apportionment Assessment

The problem of allocating liability cleanup costs is an arduous task when more than one potentially responsible party has contributed to the groundwater plume. This problem is most likely to be encountered when dealing with methyl- tert -butyl-ether (MTBE) contamination, as MTBE is seen to travel large distances in underlying aquifers. There has been a signi®cant effort in the recent past to develop liability allocation methodologies that incorporate fate and transport behavior and toxicological characteristics of the contaminants. The application of such methods often requires estimation of contaminant input from the vadose zone into the underlying aquifer. A screening level analysis is presented here to develop preliminary insights on relative mass contributions arising from different source types. The analysis illustrates how different vadose zone conceptualizations lead to vastly different contaminant loadings. Parametric studies indicate that the contaminant flux into the aquifer is very sensitive to changes in water infiltration rates. Hence, a reliable estimate of this parameter is critical for equitable allocation of remedial costs. Conceptual model formulation, should focus on identifying whether the fuel present in the aquifer can flow as a separate phase. It is also important to obtain reliable estimates for fluid saturations at the site.