Analysis of hydrocarbon leaks and verification as an operational barrier

Prevention of hydrocarbon (HC) leaks is important; they are the most critical precursor events that may lead to major accidents, such as the Piper Alpha catastrophe in 1988. The number of HC leaks on offshore production installations on the Norwegian Continental Shelf peaked just after year 2000, with more than 40 leaks per year with initial rate above 0.1?kg/s. The Norwegian Oil and Gas Association carried out a reduction project from 2003 until 2007, which resulted in 10 HC leaks above 0.1?kg/s in 2007. The number of leaks increased in the years after 2007 and was on average 15 in the period 2008–2010, without any significant increase in the number of installations. A new initiative was launched early in 2011 in order to reduce the number of HC leaks further. A study performed by the project concludes that more than 50% of the leaks are associated with failure of operational barriers during manual intervention into the process systems. Human and organisational factors are dominating with respect to circumstances and root causes. The study has further demonstrated the high importance of verification as an operational barrier and has shown that many of the failures do not have multiple operational barriers in the form of several verifications and a leak test at the end. This finding is crucial in order to understand the criticality of performing the planned verifications, perform them in an independent manner according to the procedures and make sure that the focus is on detecting failures during the verification. This paper presents the analysis of HC leaks, with emphasis on operational barriers and importance of verification.     

水银血压计的正确使用维修保养对其在计量检定中的影响

目的:分析水银血压计在计量检定中的常见故障和维修方法,为更好的使用保养维修水银血压计提供借鉴。方法:统计与分析2009年度萝北县计量检定测试所对萝北县区域内的十家医院的188台水银血压计的检定记录和维修记录。结果:虽然水银血压计经维修后合格率高达98.94%,但是一次性检定合格率并不高,只有61.17%,其中经维修后合格的比例占总检定台件数的37.76%。在维修过程中,又以示值管内壁有污物,气囊、橡胶球、橡胶管老化最多。示值管内有污物的故障占总检定台件数的29.79%,气囊、胶管、胶球漏气老化故障占总检定台件数的5.85%,其他的故障占总检定台件数的3.19%。结论:加强水银血压计的日常维护保养,熟练掌握其使用技术,是保障水银血压计准确度的关键。     

浅谈煤矿建筑修缮工程的造价控制

由于国内大多数矿务集团的大中型煤矿建立于六七十年代,建筑设施陈旧老化严重,正处于老化加速期,随着建筑物服务年限的增长,修缮工程投资会逐步加大。如何控制好修缮工程的造价成为了煤矿后勤基建工作中的重点和难点。这就要求我们工程技术人员针对煤矿建筑和修缮工程管理工作的特点,增强经济意识,通过技术、经济手段,有效地控制修缮工程的造价,使企业以合理的资金达到投资的目的。     

AP1000仪控保护系统的设计验证与测试方案研究

本文对AP1000电站仪控保护系统的设计验证与测试方案进行了深入研究,从其遵循的法规体系,设计验证方法,测试范围,集成策略,测试分级,实施过程等多个方面进行了分析,从而形成了一套针对于第三代非能动核电站仪控保护系统,自开发至应用的完整框架结构,对后续项目的开展有着十分重要的借鉴意义,也为后期系统国产化推进提供了参照标准。     

Enabling model checking for collaborative process analysis: from BPMN to ‘Network of Timed Automata’

Interoperability is a prerequisite for partners involved in performing collaboration. As a consequence, the lack of interoperability is now considered a major obstacle. The research work presented in this paper aims to develop an approach that allows specifying and verifying a set of interoperability requirements to be satisfied by each partner in the collaborative process prior to process implementation. To enable the verification of these interoperability requirements, it is necessary first and foremost to generate a model of the targeted collaborative process; for this research effort, the standardised language BPMN 2.0 is used. Afterwards, a verification technique must be introduced, and model checking is the preferred option herein. This paper focuses on application of the model checker UPPAAL in order to verify interoperability requirements for the given collaborative process model. At first, this step entails translating the collaborative process model from BPMN into a UPPAAL modelling language called ‘Network of Timed Automata’. Second, it becomes necessary to formalise interoperability requirements into properties with the dedicated UPPAAL language, i.e. the temporal logic TCTL.     

矿产资源两库衔接中各数据库对应关系清理

在四川省两库衔接工作中,各数据库来源独立、差异性明显、关联性差,导致不能简单的将核查成果引入储量数据库。涉及矿产资源储量管理的资源储量登记数据库、储量数据库和采矿权管理库的对应关系清理工作成为关键环节,为储量库的修改工作奠定基础。     

义乌国际货运代理企业特殊“外贸”服务探究

在目前国际贸易机制下,外商个人来义乌现场采购有时会遇到资金瓶颈、外汇核销等难题,需要有解决方案的提供方。而国际货运代理企业在开展经营活动时,会应客户需求提供相应的服务。因此,义乌部分货代企业在行业竞争激烈的背景下,为了更好地掌握货源,迎合外商的特殊需求,提供采购资金支持、核销服务等特殊＂外贸＂服务。该类服务是现行对外经济发展特定阶段的产物,将随着国家外贸运行机制的逐步完善而逐渐消失。     

一种利用EDA技术快速验证序列信号发生器设计的教学探索

本文针对《数字电子技术》课程中序列信号发生器的设计这一教学难点问题,提出了利用EDA电子工作平台Multisim进行快速验证的教学方法,首先从理论上介绍了序列信号发生器的两种设计方案,即反馈移位型和计数型,进而以11010序列信号发生器为例详细描述了实现两种设计方案的各个步骤,在完成理论设计后即用Multisim构造电路图进行仿真验证,教学实践表明,仿真波形直观有效,此教法效果很好。该教法方便、简单、具有很强的实用性,是数字电子技术课程教学方法的一种积极探索。     

上市公司社会责任审计的理论建构与实践问题探索

随着上市公司履行社会责任情况的信息披露日益受到利益相关者的密切关注,作为履行第三方鉴证责任的上市公司社会责任审计也越来越受到理论界和实务界的重视,因此通过理论建构与实践操作两个层面对上市公司社会责任审计问题进行有关探索十分必要。上市公司社会责任审计的理论框架可以从审计依据、审计原则、审计主体、审计内容、审计目标五个方面来构建;上市公司社会责任审计的实践问题可以从强化上市公司社会责任审计信息披露的监管、构建上市公司社会责任审计的标准、巩固上市公司社会责任审计的依据、探索上市公司社会责任审计的辅助机制和培养上市公司社会责任审计人员几个方面来探索。     

国外森林认证研究综述

对近年来国外学者对森林认证研究成果进行综述,着重归纳分析了森林认证的特点、实施的影响因素、森林认证的影响、森林认证与合法性验证、企业社会责任、信任与森林认证关系等方面的成果和主要观点。在评价的基础上指出未来的研究趋势。