An optimal level of dust explosion risk management: Framework and application

The current research provides guidance on the prevention and mitigation of dust explosion using a Quantitative Risk Management Framework (QRMF). Using concepts drawn from previous studies, the framework consists of three main steps: (i) a new combined safety management protocol, (ii) the use of DESC (Dust Explosion Simulation Code) and FTA (Fault Tree Analysis) to assess explosion consequences and likelihood, respectively, and (iii) application of the hierarchy of controls (inherent, engineered and procedural safety). QRMF assessment of an industrial case study showed that the original process was at high risk. DESC simulations and Probit equations determined the destructive percentages. FTAs revealed high probabilities of explosion occurrence; in addition, detailed individual and societal risks calculations were made, before and after the framework was applied. Based on the hierarchy of controls technique, the framework showed significant risk reduction to the point where the residual risk was acceptable for the process.     

Worst-case identification of gas dispersion for gas detector mapping using dispersion modeling

To quickly and accurately quantify the material release in process units, gas detectors may be placed according to the results of gas dispersion modeling. DNV's PHAST software is one of the most useful and reliable tools for material dispersion modeling. In this software, fluid dispersion is modeled based on the process conditions, the weather conditions and the specifications of the material release point. However, varying weather conditions throughout the year and the exact determination of the release point on the plot plan and the release elevation are problematic; these issues cause the results to be non-exact and non-integrated. Choosing the most appropriate conditions is challenging. In this paper, a scheme was provided to select the most appropriate conditions for gas dispersion modeling. This scheme approaches modeling based on the worst-case scenario (the situation in which the dispersed gas reaches the detector later in comparison to the other cases). Therefore, different weather conditions, release elevations and release points on the plot plan were modeled for an absorber tower of the Gonbadli Dehydration Unit of the Khangiran Refinery. The worst case of each release condition was then chosen. Finally, gas detectors were placed using the gas dispersion modeling results based on the worst-case scenario.     

Physical Symptoms in Young Adults and Their Use of Different Computers and Mobile Phones

This paper presents the use of new technical equipment by young adults (30 years old or younger), and the physical symptoms they have. The paper then analyses how the symptoms are associated with the use of computers and mobile phones, taking into account the background information. The study is based on a survey of 15000 working-age ( 18-65) Finns. The responses (1563) covering young adults’ physical symptoms were analysed. Altogether 53.3% of all young adults had pretty often or more frequently pain, numbness or aches in the neck and 32.2% had aches in the hip and lower back. Women experienced more pain, numbness or aches in the neck (65.0%) than men (34.5%). The use of different computers at leisure quite often had an association with some symptoms in different parts of the body. In addition, exhaustion at work had associations with some physical symptoms. In the future, it is essential to note ergonomic reasons and exhaustion at work when young adults experience pain, numbness or aches.     

Analysis of Conditions and Organization of Work of Notebook Computer Users

Abstract

Aim. The aim of this study was to evaluate working conditions with a notebook computer (notebook) as a potential cause of musculoskeletal disorders. Material and methods. The study had 2 stages. The first one was a questionnaire survey among 300 notebook users. The next stage was an expert analysis of 53 randomly selected workstations. The questionnaire survey included questions about the participants, their working conditions, work organization and also duration of work with a notebook. Results and conclusions. The results of the research showed that most examined operators used a notebook as a basic working tool. The most important irregularities included an unadjustable working surface, unadjustable height of the seat pan and backrest, unadjustable height and distance between the armrests and no additional ergonomic devices (external keyboard, docking station, notebook stand or footstool).     

A Comparison of VDT Workstation Adjustment Methods by Evaluating and Optimizing VDT Operator’s Seated Posture

Three methods of visual display terminal (VDT) workstation adjustment were compared in this study in order to investigate their effects on the operator’s seated posture. The first two methods were adjustments made both with and without any suggestion on the correct seated posture. The third method was an adjustment after which the workstation settings were initially set according to the results recommended by the IntelAd computer program. Ten male and 5 female participants were asked to readjust a VDT workstation until their most comfortable seated posture was obtained. When comparing the final seated postures to the ones ergonomically recommended, it was found that the workstation adjustment assisted by the computer program yielded the best result, followed by the adjustment without any suggestion on the seated posture, and then the adjustment with a suggestion on the seated posture. Furthermore, factors such as gender and typing skill level were not found to have any significant influence on the results.     

计算机模拟警戒作业疲劳与绩效测量实验设计*

为探索警戒作业工间休息机制,设计计算机模拟监控警戒作业实验研究疲劳与绩效之间的关系。通过对9个时间单元绩效数据的两两比较,发现原有实验方案存在不合理性。分析心理厌倦和暂时性注意缺失对作业绩效的干扰,找出问题根源。通过调整任务界面和参数、增加声音警示音、设置时间进度条、加强实验前自我检查和培训环节对实验方案进行改进,并检验改进效果。结果表明:改进后实验方案产生的数据能客观描述监控警戒作业疲劳与绩效之间的关系,实验结论可为设计警戒作业工间休息制度提供理论依据。     

A Radio Communication System for Neuronal Signals

Abstract

To collect neuronal activity data from awake, freely behaving animals, we developed miniature telemetry recording system. The integrated system consists of four major components: 1) Microelectrodes and micro-driver assembly, 2) analog front end (AFE), 3) programmable system on chip (PSoC), and 4) radio transceiver and the LabVIEW were used as a platform for the graphic user interface. The result showed the system was able to record and analyze neuronal recordings in freely moving animals and lasted continuously for a time period of a week or more. This is very useful for the study of the interdisciplinary research of neuroscience and information engineering techniques. The circuits and architecture of the devices can be adapted for neurobiology and research with other small animals.     

Minimizing external indirect health costs due to aerosol population exposure: a case study from Northern Italy

Environmental Agencies require Decision Support Systems, in order to plan Air Quality Policies considering the cost of emission reduction measures and the human health effects (with related social costs). The use of Decision Support Systems is also useful to spread information to general public, explaining the effectiveness of proposed air quality plans. In this paper, a multi-objective approach to control PM10 concentration at a regional level is presented. The problem considers both the internal costs (due to the implementation of emission reduction measures) and the external costs (due to population exposure to high PM10 concentrations). To model PM10 concentrations, a single surrogate model is used for the entire domain, allowing the implementation of a very efficient optimization procedure. The surrogate model is derived through a set of 10 simulations, performed using a Chemistry Transport Model fed with different emission reduction scenarios. The methodology is applied to Northern Italy, a region affected by very high PM10 concentrations that exceed the limit values specified by the EU legislation.     

System dynamics modeling for municipal water demand estimation in an urban region under uncertain economic impacts

Accurate prediction of municipal water demand is critically important to water utilities in fast-growing urban regions for drinking water system planning, design, and water utility asset management. Achieving the desired prediction accuracy is challenging, however, because the forecasting model must simultaneously consider a variety of factors associated with climate changes, economic development, population growth and migration, and even consumer behavioral patterns. Traditional forecasting models such as multivariate regression and time series analysis, as well as advanced modeling techniques (e.g., expert systems and artificial neural networks), are often applied for either short- or long-term water demand projections, yet few can adequately manage the dynamics of a water supply system because of the limitations in modeling structures. Potential challenges also arise from a lack of long and continuous historical records of water demand and its dependent variables. The objectives of this study were to (1) thoroughly review water demand forecasting models over the past five decades, and (2) propose a new system dynamics model to reflect the intrinsic relationship between water demand and macroeconomic environment using out-of-sample estimation for long-term municipal water demand forecasts in a fast-growing urban region. This system dynamics model is based on a coupled modeling structure that takes into account the interactions among economic and social dimensions, offering a realistic platform for practical use. Practical implementation of this water demand forecasting tool was assessed by using a case study under the most recent alternate fluctuations of economic boom and downturn environments.     

探析模糊控制无线节点网路技术在石油化工安全中的应用

在石油化工领域,为了有效预防和控制易燃易爆有毒气体的泄漏燃烧爆炸,利用计算机技术和电信通讯网络,处理信息和传输信息,以监测探头、无线接收发模块、监控主计算机三部分构建一套安全预警监控系统。在化工厂或危险源区域的危险点,设置多处监测节点,接受信息传输到无线接收发模块,进行模糊化计算、推理,判断后输出结果到监控主计算机,监控主计算机向安全管理人员、现场工作人员等发出报警信息。