Optimal feed profile for a second order reaction in a semi-batch reactor under safety constraints: Experimental study

Maximising the yield of the second order reaction (2-butanol+propionic anhydride) by manipulating the inlet flow rate is considered for an isothermal semi-batch process. First a procedure for the determination of the kinetic parameters using coupled spectroscopic and calorimetric methods is presented. Then an optimisation of the reaction system is performed numerically and verified experimentally. Constraints on the amount of heat produced and on the temperature attainable in the case of cooling failure are imposed for safety consideration.     

我国部分保健与安全活动经济代价的初步评价

社会中的许多卫生保健活动都需要在经济代价和人的安全健康之间作出权衡。这种权衡往往需要确定危害人们健康和安全的经济价值。笔者从人力资本和支付意愿两个方面,对我国卫生、环保、安全有关的经济数据进行了评价分析。在人力资本方面,考虑了人均终生的国民生产总值、国民收入、消费水平、职工工资、城乡居民收入。在支付意愿方面,考虑了医疗救治的费用、社会保险费用、司法赔偿、职业劳动保护费用、降低辐射危害的费用以及政府采用数值等。根据这些分析评价,笔者建议：我国卫生保健有关的人的社会经济价值,若以１９９０ 年可比价格计算,分布在（９～４０）万元之间,适中的估计为２０ 万元。     

简论安全管理的警示职能——墨菲定律的启示

通过对墨菲定律的研究,得到两点启示,进而论证了安全管理必须发挥警示职能的科学道理,同时也表明了发挥警示职能对于提高安全管理水平的重要作用     

煤矿事故中“安全流变-突变论”的研究

“安全流变－ 突变论”是安全科学理论的一个新内容。通过用此理论,对煤矿几类典型的事故分析和综合,进一步认识事故发生、发展以及结束的机理,获得与事故密切联系的几个关键状态点,由这些状态点可以预测、预报事故。     

Basic Principles and Ecological Consequences of Altered Flow Regimes for Aquatic Biodiversity

The flow regime is regarded by many aquatic ecologists to be the key driver of river and floodplain wetland ecosystems. We have focused this literature review around four key principles to highlight the important mechanisms that link hydrology and aquatic biodiversity and to illustrate the consequent impacts of altered flow regimes: Firstly, flow is a major determinant of physical habitat in streams, which in turn is a major determinant of biotic composition; Secondly, aquatic species have evolved life history strategies primarily in direct response to the natural flow regimes; Thirdly, maintenance of natural patterns of longitudinal and lateral connectivity is essential to the viability of populations of many riverine species; Finally, the invasion and success of exotic and introduced species in rivers is facilitated by the alteration of flow regimes. The impacts of flow change are manifest across broad taxonomic groups including riverine plants, invertebrates, and fish. Despite growing recognition of these relationships, ecologists still struggle to predict and quantify biotic responses to altered flow regimes. One obvious difficulty is the ability to distinguish the direct effects of modified flow regimes from impacts associated with land-use change that often accompanies water resource development. Currently, evidence about how rivers function in relation to flow regime and the flows that aquatic organisms need exists largely as a series of untested hypotheses. To overcome these problems, aquatic science needs to move quickly into a manipulative or experimental phase, preferably with the aims of restoration and measuring ecosystem response.     

Dynamic risk analysis of offloading process in floating liquefied natural gas (FLNG) platform using Bayesian Network

The growing demand for natural gas has pushed oil and gas exploration to more isolated and previously untapped regions around the world where construction of LNG processing plants is not always a viable option. The development of FLNG will allow floating plants to be positioned in remote offshore areas and subsequently produce, liquefy, store and offload LNG in the one position. The offloading process from an FLNG platform to a gas tanker can be a high risk operation. It consists of LNG being transferred, in hostile environments, through loading arms or flexible cryogenic hoses into a carrier which then transports the LNG to onshore facilities. During the carrier's offloading process at onshore terminals, it again involves risk that may result in an accident such as collision, leakage and/or grounding. It is therefore critical to assess and monitor all risks associated with the offloading operation. This study is aimed at developing a novel methodology using Bayesian Network (BN) to conduct the dynamic safety analysis for the offloading process of an LNG carrier. It investigates different risk factors associated with LNG offloading procedures in order to predict the probability of undesirable accidents. Dynamic failure assessment using Bayesian theory can estimate the likelihood of the occurrence of an event. It can also estimate the failure probability of the safety system and thereby develop a dynamic failure assessment tool for the offloading process at a particular FLNG plant. The main objectives of this paper are: to understand the LNG offloading process, to identify hazardous events during offloading operation, and to perform failure analysis (modelling) of critical accidents and/or events. Most importantly, it is to evaluate and compare risks. A sensitivity analysis has been performed to validate the risk models and to study the behaviour of the most influential factors. The results have indicated that collision is the most probable accident to occur during the offloading process of an LNG carrier at berth, which may have catastrophic consequences.     

What’s missing from Ostrom? Combining design principles with the theory of sociocultural viability

Since 1990, Elinor Ostrom’s design principles for common property resource (CPR) institutions have been highly influential, offering a counter to pessimistic arguments about resource users’ prospects of cooperating to manage CPRs sustainably. However, the theoretical underpinnings of Ostrom’s theory have been criticised: as unfairly negative towards macro-level interventions; as utilising an overly narrow conceptualisation of rationality; and under appreciative of the role of power. These criticisms are examined using insights drawn from the theory of sociocultural viability (cultural theory, for short), a theory of plural rationality related to context. Utilising the case of Faroese whaling, the research aim is to assess the extent that cultural theory ameliorates criticisms laid at Ostrom’s design principles. It finds that Ostrom’s research trajectory was reaching the limits of methodological individualism’s ability to grasp rational behaviour and suggests the design principles may in effect be integrated with cultural theory.     

TAMMEF therapy in the treatment of shoulder periarthritis: efficacy and safety

The utility and the safety of the extremely low frequencies (ELF) electromagnetic fields in the treatment of numerous diseases have been demonstrated. Moreover, the effects of these fields seem to depend on their respective codes (frequency, intensity, waveform). We want to value the effects and the safety of the therapeutic application of a musically modulated electromagnetic field (TAMMEF) system, which field is piloted by a musical signal and its parameters (frequency, intensity, waveform) are modified in time, randomly varying within the respective ranges, so that all possible codes can occur during a single application. Sixty subjects, affected by shoulder periarthritis were enrolled in the study and randomly divided into three groups of 20 patients each: the first exposed to TAMMEF, the second exposed to ELF, the third exposed to a simulated field. All subjects underwent a cycle of 15 daily sessions of 30 min each and a clinical examination upon enrolment, after 7 days of therapy, at the end of the cycle and at a follow-up 30 days later. All the patients of TAMMEF group and ELF group completed the therapy without the appearance of side effects: they presented a significant improvement of the subjective pain and the functional limitation, which remained stable at the follow-up examination. In those exposed to a simulated field group, there was no improvement of the pain symptoms or articular functionality. This study suggests that the TAMMEF system is efficacious and safe in the control of pain symptoms and in the reduction of functional limitation in patients with shoulder periarthritis. Moreover, the effects of the TAMMEF system cover those produced by the ELF field.     

A toxicity-based method for evaluating safety of reclaimed water for environmental reuses

A large quantity of toxic chemical pollutants possibly remains in reclaimed water due to the limited removal efficiency in traditional reclamation processes. It is not enough to guarantee the safety of reclaimed water using conventional water quality criteria. An integrated assessment method based on toxicity test is necessary to vividly depict the safety of reclaimed water for reuse. A toxicity test battery consisting of lethality, genotoxicity and endocrine disrupting effect was designed to screen the multiple biological effects of residual toxic chemicals in reclaimed water. The toxicity results of reclaimed water were converted into the equivalent concentrations of the corresponding positive reference substances（EQC）. Simultaneously, the predicted no-effect concentration（PNEC） of each positive reference substance was obtained by analyzing the species sensitivity distribution（SSD） of toxicity data. An index ＂toxicity score＂ was proposed and valued as 1, 2, 3, or 4 depending on the ratio of the corresponding EQC to PNEC. For vividly ranking the safety of reclaimed water, an integrated assessment index ＂toxicity rank＂ was proposed, which was classified into A, B, C, or D rank with A being the safest. The proposed method was proved to be effective in evaluating reclaimed water samples in case studies.     

自然资源与环境价值评估:条件估值法及应用原则探讨

自然资源与环境价值评估是当前环境经济学的研究热点,条件估值法C(VM)在国外经过近40年的发展已较为完善并已成为自然资源和环境价值评估的主要技术方法之一。但由于缺少一套完备的原则框架加以指导,国内具体实证研究存在不同的问题和困惑。论文系统回顾了条件价值法的国内外主要研究进展,基于国际上已建立的CVM原则并结合我国自然资源与环境价值评估的实际情形,提出了当前国内CVM研究可供遵循的9条建议性原则,涉及问卷设计与预调查、调查实施、数据分析和费用效益分析等各步骤。以此为基础对国内CVM价值评估研究存在的一些问题作了初步探讨。最后指出,环境资源价值评估CVM研究需要遵循的原则和注意的问题,可能还不止于所建原则,具体操作过程可能需要适时适地地调整并需要继续完善。