Micropollutant removal and disinfection byproduct control by sequential peroxymonosulfate-UV treatment in water: A case study with sulfamethoxazole

UV/peroxymonosulfate (UV/PMS) advanced oxidation process has attracted significant attention for removal of micropollutants in water. However, during practical water treatment applications, the PMS treatment must be performed before the UV treatment to achieve full contact. In this study, sulfamethoxazole (SMX) was selected as the target micropollutant. Four different operational approaches, including UV alone, PMS alone, simultaneous UV/PMS and sequential PMS-UV, were compared for their differences in SMX removal and disinfection by-product (DBP) formation potentials during chlorine-driven disinfection. Among the four approaches, UV/PMS and PMS-UV achieved over 90% removal efficiencies for SMX without substantial differences. For raw water, the trichloronitromethane (TCNM) formation potential after treatment with PMS-UV was lower than that after UV/PMS treatment. The time interval over which the PMS-UV process was conducted had little effect on the final removal efficiency for SMX. However, a brief (5 min) pre-PMS treatment significantly reduced the TCNM formation potential and the genotoxicity from DBPs. The formation risk for TCNM during chlorination increased markedly with increasing PMS dosages, and the appropriate dosage under these experimental conditions was suggested to be 0.5–1.0 mmol/L. Under alkaline conditions, PMS-UV treatment can enhance SMX degradation as well as dramatically reduced the formation potentials for haloketones, haloacetonitriles and halonitromethanes. This study suggests that proper optimization of UV/PMS processes can remove SMX and reduce its DBP formation.     

关于设立公共消防安全管理硕士教育的构想

消防安全是社会安定与经济发展的保证.提高公共消防安全管理水平,实现消防安全,是人心所向.然而,我国目前缺乏高层次消防管理人才,消防硕士教育中没有公共消防安全管理专业,这严重影响了公共消防安全管理水平的提高.本文认为,我国消防硕士教育专业设置不合理,提出了增设公共消防安全管理硕士的必要性和重要性,并提出了公共消防安全管理学科体系的构建与公共消防管理硕士课程体系的设置框架.     

Safety and associated parameters influencing performance of rail road grade crossings: A critical review of state of the art

Introduction: Railroad grade crossings (RRGCs) have emerged as critical transportation infrastructures from the point of safety and operational aspects because two modes of transportation intermingle at the intersecting zone; the understanding of safety and traffic operation at RRGC is of prime concern while planning and designing this transportation facility. Method: In this context, this work tries to comprehend RRGC performance-related parameters from published literature and figure out critical gaps. An international synthesis on the identified potential parameters influencing the RRGC performance (i.e., safety, driver behavior, and operational impact) was carried out by critically reviewing the articles published worldwide. Furthermore, key findings, used variables, analysis methods, research gaps, and recommendations were studied. Results: The review revealed that many researchers had explored the driver behavior and safety aspect based on past crash data and violations prevailing at RRGC. However, little research has been done to evaluate the effect of highways' operational characteristics on the performance of RRGC. Moreover, limited investigation has been carried out to understand the dilemma of drivers and the proactive safety evaluation of pedestrians and non-motorized vehicles at RRGC. A total of seven critical research gaps concerning parameters are recognized, facilitating a clear agenda for further research pertaining to RRGC performance.     

我国安全软科学的发展历程、现状与未来趋势

为准确梳理我国安全软科学进展,以GB/T 13745-2009《学科分类与代码》安全科学技术(620)一级学科体系中的软科学分支学科为范畴,论证安全软科学的价值作用及其要素贡献率;从历史与历程、演进与现状、趋势与挑战3个层面以及学科发展、学科体系、学科范畴、体制法制、监管治理、研究热点、研究前沿等多维度和多视角进行归纳...     

Emergency resources demand prediction using case-based reasoning

The demand prediction on emergency resources is the premise and basis of optimal allocation of emergency resources. Nowadays, there are only few researches on this aspect in China and abroad. For this reason, the paper aims at the characteristics of emergency resource demand prediction and presents a method for emergency resource demand prediction using case-based reasoning (CBR), which is also a method based on risk analysis. This prediction method cannot only provide a basis for emergency resource reserve and allocation in future, but also provide a method and model support for the emergency resources allocation decision-making system to be constructed in future.     

安全系统学科建设安全工程专业的研究

通过对安全系统学科的认识与研究．认为我国安全工程高等教育按安全系统学科建设安全工程专业,构架符合安全科学规律的安全工程专业知识结构,培养和造就掌握系统安全科学理论与技术知识,能够解决客观物质系统中的系列安全问题的既“专”又“博“的安全工程技术人才,才能满足社会对安全人才的需要和市场对安全人才的要求。     

Development of an integrated decision-support model for density management within jack pine stand-types

The objectives of this study were to (1) develop a modular-based structural stand density management model (SSDMM) and corresponding algorithmic analogue for natural (naturally regenerated stands without a history of density regulation) and managed (naturally or artificially regenerated stands with a history of density regulation) jack pine (Pinus banksiana Lamb.) stand-types, and (2) demonstrate the utility of the model in operational density management decision-making. Employing an Ontario-centric database consisting of 262 and 221 tree-list measurements obtained from 91 and 139 permanent and temporary sample plots situated within natural and managed stand-types, respectively, combined with data derived from density control experiments and sawmill simulation studies, six integrated estimation modules were constructed: Module A consisted of the parameterization of the core yield–density relationships which together drive the entire yield prediction system (e.g., size–density relationships for quadratic mean diameter, dominant height, mean volume, and mean live crown ratio, and site-specific height–age relationships); Module B consisted of the development of Weibull-based parameter prediction equation systems for recovering diameter distributions and composite height-diameter equations for height estimation; Module C consisted of the development of composite taper equations for predicting log products and stem volumes; Module D consisted of the development of allometric-based composite biomass equations for each above-ground component (bark, stem, branch and foliage) from which biomass estimates and associated carbon-based equivalents were derived; Module E consisted of the development of sawmill-specific composite equations for estimating chip and lumber volumes; and Module F consisted of the development of composite equations for estimating wood density and mean maximum branch diameter. The utility of the model was demonstrated by simultaneously contrasting a set of complex density management regimes (commercial thinning and variable planting densities) in terms of a broad array of stand-level yield outcomes and performance measures: overall productivity, log-product distributions, biomass production and carbon yields, recoverable products (chip and lumber volumes) and associated monetary values, economic efficiency, duration of optimal site occupancy, structural stability, and fibre attributes (wood density and mean maximum branch diameter). In summary, the modular-based SSDMM provides the analytical foundation for evaluating the likelihood of realizing a multitude of stand-level objectives when designing density control regimes for jack pine stand-types.     

On the operator action analysis to reduce operational risk in research reactors

Human errors during operation and the resulting increase in operational risk are major concerns for nuclear reactors, just as they are for all industries. Additionally, human reliability analysis together with probabilistic risk analysis is a key element in reducing operational risk. The purpose of this paper is to analyze human reliability using appropriate methods for the probabilistic representation and calculation of human error to be used alongside probabilistic risk analysis in order to reduce the operational risk of the reactor operation. We present a technique for human error rate prediction and standardized plant analysis risk. Human reliability methods have been utilized to quantify different categories of human errors, which have been applied extensively to nuclear power plants. The Tehran research reactor is selected here as a case study, and after consultation with reactor operators and engineers human errors have been identified and adequate performance shaping factors assigned in order to calculate accurate probabilities of human failure.     

HALT试验技术的研究

高加速寿命应力试验（HALT）,是一种通过施加阶梯强化应力于试品,达到快速发现产品潜在缺陷,操作设计边际及结构强度极限的试验方法,主要应用于产品研发设计阶段。由于该方法效果明显,目前已越来越多的电子电气产品制造商认可并推广使用,成为研发设计工程师提高产品可靠性的重要试验手段。本文简要介绍HALT试验的目的,并结合实际,探讨了HALT试验设备的关键性能指标。另外,基于日常实践经验,重点分析和讨论了HALT试验过程中应该关注的一些技术处置措施,从而帮助测试人员正确执行HALT。     

ABR反应器处理低浓度废水的研究

对ABR反应器处理低浓度废水的效果及运行特性进行了研究。在中温(35±0.5℃),进水有机负荷为0.5～7.0kgCODCr/(m~3.d),HRT=3～12h,进水CODCr浓度分别为150,350,550和850mg/L时,CODCr去除率分别达50%,80%～87%,86%～92%和90%～95%,反应器出水CODCr浓度在70～90mg/L。研究表明,该反应器处理低浓度废水时,不仅具有良好的处理效果,而且运行稳定。