风险评估技术在压力容器行业的应用

2009版《固容规》将基于失效模式的风险评估理念引入到压力容器的设计、制造、检验和使用中。本文举例介绍了风险评估技术在压力容器设计中的具体应用以及RBI技术在化工装备管理中的实施方法。风险评估技术的采用将大大推动压力容器行业的发展和我国技术经济的进步。     

Prevention of travel-related foodborne diseases: Microbiological risk assessment of food handlers and ready-to-eat foods in northern Italy airport restaurants

The focus of this study was to assess the hygienic standards of 44 foodservice facilities located in three Italian International Airports (with an output ranging from 100 to 800 meals a day), by monitoring the microbiological quality and safety of foods ready for consumption (n = 773), food contact surfaces (n = 302), and food handlers (n = 287). The hygienic standard of surfaces was sufficiently high. Only 7.9% of surfaces did not conform with advisory standards in terms of total coliforms, and 2.6% were found to be contaminated with Enterococcus spp. at ≥1.0 log₁₀ CFU/cm². The hygienic standard of washed and disinfected hands of food workers was not adequately high: the total bacterial count and coagulase positive Staphylococci exceeded the satisfactory limit in 8.4% and 3.5% of cases, respectively. The microbial analysis of foods examined showed an absence of Listeria monocytogenes and Salmonella spp. Food sample analyses highlighted a percentage of samples that did not conform to microbial reference standards: Staphylococcus aureus non-conforming percentages ranged from 2.3% for “fully cooked food” to 9.2% for “raw fruit and vegetables”; Escherichia coli, from 0.0% for “raw fruit and vegetables” to 6.1% for “cooked and uncooked foods”; total coliforms from 14.3% for “fully cooked food” to 79.8% for “cooked and uncooked food”. In conclusion, the results suggest that more effort is needed in the application of HACCP principles. In order to prevent travel-related foodborne infections, various changes in the timing of food preparation and holding temperatures are needed, together with further training of food handlers.     

Microbiological quality assessment of garri with reference to thermonuclease activity

The microbiological quality of garri obtained from open markets and traditional processing industry in Benin City with reference to staphylococcal contamination was investigated. Enumeration of the total heterotrophic bacteria, total fungal propagules and Staphylococcus aureus in food samples was carried out using appropriate media. The staphylococcal thermonuclease activity determination was used as an indicator of previous (substantial) growth of S. aureus and possible presence of staphylococcal enterotoxins. The total heterotrophic bacterial count of the open markets’ samples was 7.75±2.87×10³ cfu/g with corresponding staphylococcal count of 1.65±0.82×10³ and fungal propagule count of 2.50±1.14×10² cfu/g. Samples obtained immediately after processing from the traditional garri industry revealed total heterotrophic bacterial count of 5.00×10¹ cfu/g; staphylococcal count of 5.00×10⁰ cfu/g and no fungal count. The zone diameter of thermonuclease activity was 8.13±0.52 mm for open markets’ samples while traditional processing industry samples have 7.83±0.54 mm. From the study, it was found that there was contamination and growth of S. aureus and possibly the presence of staphylococcal enterotoxin in the product. The public health significance of the microorganisms with the production of thermonuclease and enterotoxins by S. aureus are discussed.     

Advances in biofilm control for food and beverage industry using organo-silane technology: A review

Cell adhesion can be a potential problem as well as a valuable tool for microbiological engineering. It can lead to biofouling, contamination of product and corrosion. On the other hand, cell adhesion is purposely employed in fermenters and bioreactors to influence reactor performance. This paper presents an overview of organo-functional silanes – their chemistry, properties, use, and the main laboratory experiments that can be of interest to the food and beverage industry. The purpose is to introduce and explore possibilities for using organo-silane combinations to enhance or reduce microbial adhesion.     

Implementation of non-regulatory food safety management schemes in New Zealand: A survey of the food and beverage industry

Using a questionnaire survey, this paper examines the motivations, challenges, and impacts, and the role of third-party certification bodies' (CBs) in the implementation of non-regulatory food safety management schemes (FSMS) in the New Zealand food and beverage industry. The survey involved 115 manufacturing enterprises out of which 95.7% indicated that they had one or more FSMS in place, and 43.5% stated that they implemented one or more non-regulatory FSMS. Three main categories of non-regulatory FSMS have been implemented in New Zealand: public international standard schemes, public industry sector schemes and private individual firm schemes. The most important motivation for implementing non-regulatory FSMS is meeting the requirements of major customers. As a consequence of the implementation of non-regulatory FSMS, desirable changes have been experienced by the respondents, such as the improvement of product traceability, increasing food safety awareness of employees, satisfaction with the ability to maintain customers, decreasing the cost of wastage and reduced customer complaints. The results also indicated that the major challenges encountered during the implementation of non-regulatory FSMS were increased paper work, record keeping and documentation, and the cost of development and implementation. The costs of system design and development, and external audit fees are the major implementation costs of non-regulatory FSMS, while external surveillance audit fees and product testing are the significant operating costs of non-regulatory FSMS. The third-party CBs' service was rated by 66.0% of respondents as an important tool for them to continuously improve their food safety management.     

Protecting child health by preventing school-related foodborne illnesses: Microbiological risk assessment of hygiene practices,drinking water and ready-to-eat foods in Italian kindergartens and schools

The purpose of this study was to evaluate hygiene and microbial safety in 26 Italian school catering establishments. This involved monitoring the microbiological quality and safety of ready-to-eat foods (n = 395), drinking water (n = 43), food contact surfaces (n = 139), and food handlers (n = 249). Food samples analyses revealed an adequate level of microbiological quality and safety. Of particular concern was the isolation of Salmonella spp. and Listeria monocytogenes in 5.8% and 1.9% of raw vegetable samples, respectively. Escherichia coli counts exceeded the microbial reference standards in 8.6% of soft cheeses samples and in 27.3% of multi-ingredients preparations. Staphylococcus aureus counts exceeded the reference limits only in 5.7% of soft cheeses samples. The hygienic level of food contact surfaces was very high, since only 1.4% of samples showed unacceptable contamination. Concerning the food workers' hands, the results showed that the total bacterial count, coagulase positive staphylococci and Enterobacteriaceae levels exceeded the reference standards in 18.1%, 10.4%, and 11.2% of cases, respectively. The results of the water analyses indicated that 47.8% of the tap water and 10.0% of drinking water samples examined were found to be non-conforming to law limits. In conclusion, since children have a relatively lower immunity than adults, additional safety measures are needed to protect them from foodborne pathogens and high microbial contamination in school lunches. Consequently, our results suggest that various changes in the timing of food preparation and holding temperatures are needed, and good manufacturing practices and HACCP principles need to be applied more rigorously.     

The use of quantitative risk assessment in HACCP

During the hazard analysis as part of the development of a HACCP-system, first the hazards (contaminants) have to be identified and then the risks have to be assessed. Often, this assessment is restricted to a qualitative analysis. By using elements of quantitative risk assessment (QRA) the hazard analysis can be transformed into a more meaningful managerial tool. In this way the effect of control measures can be quantified, so the occurrence of contaminants in the endproducts can be estimated. Also, the quantitative risk assessment is a tool to derive or validate control measures and critical limits at process steps (CCPs). The practical use of quantitative risk assessment is demonstrated by two examples: the risk of raw fermented sausages and the risk of a pressurized meat product. It can be concluded that quantitative risk assessment is a powerful combination of food microbiology, modelling and applied statistics. It is recommended as the input for managing food safety issues as an extension or validation of the HACCP-system.     

天然气钻井人因失误事故风险定量评价方法

天然气钻井行业的事故率一直较高且人因失误占较高比例,目前尚无针对钻井施工过程人因失误事故风险的定量评价方法。为此,提出了应用德尔菲专家判断法定量评价钻井施工人因事故风险的方法,通过专家评分获得了与11类钻井作业活动相关的10种风险类别的可能性和严重度数据,计算了不同作业活动的风险水平。研究数据显示,钻井施工人因失误事故风险最高的风险类型是物体打击;人因失误事故风险最高的作业活动是钻进作业。研究结果可应用于跟踪钻井过程异常高风险时段,以便有针对性地采取风险消减措施,合理地部署现场安全工作,避免高风险的累加效应。该方法在5支钻井队应用后取得了较好的效果,可报告事故率由7.54%下降到5.24%。     

地区等级升级后的天然气管道定量风险评价技术

随着我国经济社会建设的快速发展,部分在役天然气管道所通过的地区逐渐由过去人口稀少的一级、二级地区升级为人口密集的三级、四级地区,管道失效的风险大幅度增加,急需建立相应的定量风险评价技术以确定管道的实际风险水平。为此,提出了基于可靠性的天然气管道定量风险评价流程:首先采用基于可靠性的极限状态方法计算评价管段的失效概率、采用管道失效后果模型计算管道的失效风险,并依据计算结果对地区等级升级后的天然气管道进行定量风险评价;然后引入风险可接受准则,判定地区等级升级后天然气管道的个体风险水平和社会风险水平;进而有针对性地制订风险消减、防护措施。实际应用结果表明:该技术不仅可以实现天然气管道失效风险的定量计算和评价,而且还能够对不同风险消减、防护措施进行效果检查及对比,在保障天然气管道风险可接受的前提下,实现天然气管道风险控制管理技术性和经济性的最优化。     

Environmental risk assessment for food-related substances

This report analyses various environmental risk assessment practices that are currently in place for food-related substances in both the EU and the USA. Within the EU, REACH requires the systematic review of the toxicity of chemicals, with varying degrees of extensiveness of testing required based on the quantities of the chemicals used in practice. Genetically modified organisms are another example of how the environmental impacts of food-producing crops are assessed. The requirements for the use of substances in organic agriculture imply that these should also be assessed for environmental impact. In the USA, the FDA requires environmental assessments for food substance requiring this agency’s action. The EPA has elaborated guidelines for ecological risk assessment that show parallels with the food safety assessment, including the stages of problem formulation, analysis (assessment), and risk characterisation. Also the stakeholder involvement and risk management play an important role in the procedures envisaged by these guidelines. The utility of integrated assessments has been further stressed by WHO/IPCS. It is considered that the new integrated risk-analysis approach recommended by SAFE FOODS can benefit from the integration of environmental issues, including their assessment in the risk–benefit stage of the risk analysis cycle.     

地质风险评价中的不确定性分析

地质风险概率法被广泛应用于油气资源评价中的地质风险评价。由于很难直接定义每一地质评价因子的评价(“打分”)概率模型,专家给出的都是每一评价因子的确定性评价值(“点估计”)—— 单一的、确定性评价结果并不能够很好地反映目标区域复杂地质情况的多种可能性,不可避免地出现含油气有无的高估或低估的情况。结合油气资源一体化评价软件(PetroV)的开发经验,从如何更客观地去描述地质评价因子的不确定性入手,阐述如何采用多种不确定性分析技术,更好地融合、体现专家经验以及客观表达地下复杂地质情况,从而提高地质风险概率法的不确定性表达能力：(1)通过自信度转换数学模型体现专家主观认知的不确定性;(2)将专家的定性认知进行合理的知识规则化转换,充分量化地质模型的不确定性;(3)基于地质风险概率法数学模型,利用蒙氏模拟计算符合概率分布特征的地质风险评价结果;(4)据地质风险不确定性评价结果,可获取目标区域地质风险评价的多分位评价值,为后续的勘探决策给出尽可能全面的决策方案。     

石化装置蒸气云爆炸多米诺效应风险评估

根据石化装置蒸气云爆炸的特点,引入多米诺效应风险评价法,对冲击波超压引起的多米诺效应进行研究,得出了超压对不同设备损坏概率的评价方法。     

套管段井筒完整性风险评价方法研究

井筒完整性评价的目的在于了解井筒风险状况,以便防止井筒结构产生失效破坏。影响井筒完整性的因素包括技术套管完整性、水泥环质量和地层因素3个环节,技术套管完整性是井筒完整性最重要的因素,而水泥环质量不好和地层条件差会增大井筒失效的风险,因此,整个井筒失效是3个环节失效综合的结果。利用层次分析法建立了套管井段井筒完整性的系统模型,给出了井筒完整性评价的整体思路,提出了利用套管监测、预测、测井等手段评价任意井段的井筒完整性方法,给出了对任意井深井筒完整性状态及全口井井筒完整性状态的风险评价模型。     

Using a quantitative risk assessment to mitigate risk of Listeria monocytogenes in ready-to-eat meats in Australia

To provide guidance to Australia meat processors a Monte Carlo simulation model that estimates the risk of listeriosis from processed meats in Australia [Ross, T., Rasmussen, S. R., Fazil, A., Paoli, G., & Sumner, J. (accepted for publication). Quantitative risk assessment of Listeria monocytogenes in ready-to-eat meats in Australia. International Journal of Food Microbiology] was used to assess the efficacy of alternative strategies proposed to reduce the risk of listeriosis from these products. The structure of the model enabled estimates of levels of Listeria monocytogenes throughout the predicted life of the product, and facilitated modelling of the proposed mitigations. Technological and economic constraints relevant to the Australian industry meant that, of the various proposed risk reduction strategies, the use of growth-rate retarding additives, such as salts of organic acids, were identified as the preferred risk mitigation option.     

HAZOP技术在CNG储气井风险评价中的应用

HAZOP技术是一种用于辨识装置设计缺陷、工艺过程危害及可操作性问题的定性风险评价方法,主要通过偏差查找事故发生的原因、可能造成的后果,并且在已有保护措施的基础上,提出控制或降低风险的建议措施。因其分析的系统性、科学性等优点,目前已广泛应用于石油、化工等行业。针对地下储气井腐蚀、老化等问题的日益凸显,采用HAZOP技术对CNG地下储气井展开安全性分析,共提出了建议措施94条,采用率达到90%以上,为生产安全管理工作提供了有力依据。同时,归纳总结了HAZOP技术的优缺点,明确了今后改进的方向。     

A risk profile of the Australian red meat industry: Approach and management

A risk profile of microbial, chemical and physical hazards across the supply continuum for the Australian beef, sheep and goat meat industries was developed. The aim was to provide risk managers with a risk rating of hazard:meat and meat product combinations, advise on the feasibility and advisability of risk analyses and identify research and development priorities. Hazard:red meat combinations arising from manufacturing and catering settings that have been associated with food-borne illness and their risk ranking are reported elsewhere. The profiling process was completed within a one-year timeframe and involved a planned iterative consultation process between risk managers and assessors to ensure outputs remained relevant to current risk management concerns.     

城镇燃气管网风险评估管理技术的完善建议

本文针对当前城镇燃气管网风险评估现状进行分析,以此提出相应管理技术的完善建议。     

基于钻前风险预测的井身结构优化方法

考虑钻井工程风险、基于钻前风险预测的井身结构设计是钻井施工安全顺利进行的保证。钻井工程风险在实钻过程中的主要表现是:井漏、井喷、井塌、卡钻以及井下工具失效等问题。首先基于邻井资料求取了待钻目标井含可信度的地层压力剖面,再利用钻井风险评价方法对待钻目标井井身结构设计方案进行评价,在钻前预测出可能发生的工程风险,并基于预测结果优化井身结构设计方案,规避钻井风险的发生。新方法为合理规避工程风险、调整施工方案、安全快速钻井提供了科学的依据,可以有效降低钻井工程风险发生的概率和频度,缩短建井周期,对于安全、高效钻井具有重要意义。     

含缺陷冷凝器的使用风险评价

采用有限元方法模拟了1台含缺陷冷凝器的应力状况,并进行了静强度分析。针对焊接缺陷,采用断裂力学方法分析了该含缺陷结构的安全性。利用模糊分析方法讨论了冷凝器的使用风险。结果认为,该冷凝器满足安定性理论且合乎使用原则,在使用过程中用户应承担严重的风险。