Predicting liquid jet breakup and aerosol formation during the accidental release of pressurized hydrogen fluoride

The safe production and handling of toxic chemicals is an issue of growing importance for public officials, legislators and petrochemical plant managers. Industrial and academic research is improving the understanding of a variety of phenomena related to risk assessment, and communicating these risks to concerned parties. Several groups are investigating the behavior and mitigation of accidental releases of anhydrous hydrofluoric acid. Forthcoming results of these studies will include the key issue of aerosol formation.     

Hazard analysis and safety considerations in refrigerated ammonia storage tanks

A systematic approach to find out the probability of Ammonia tank failure was adopted and a consequence analysis in case of accidental Ammonia release from refrigerated ammonia storage tanks was made. The study revealed that construction of a concrete bund wall around the tanks is not justified. Instead, it would be adequate to upgrade the safety in the common dyke around the tanks by adopting additional conventional methods.     

工贸企业危险化学品使用安全现状探析

为进一步加强危险化学品使用环节的规范化,对广东省M市工贸企业危险化学品的使用情况进行了广泛调研,并选取141家重点企业作为研究对象,利用大数据和粗糙集的约简功能,分别确定一级安全指标(安全资料、储存场所、使用场所)的18项二级安全指标的权重,并据此对使用危险化学品的工贸企业进行事故隐患分析。结果表明:工贸企业危险化学品使用过程中应将风险管理重点放到物理危险的管控上,其中易燃液体、加压气体、金属腐蚀物、易燃气体、氧化性液体的总占比达到91.6%,普遍具有火灾、爆炸、腐蚀等风险;权重结果显示,安全资料方面没有显著问题存在,储存场所中安全警示标志和仓储管理问题较突出,使用场所中需重点整治安全警示标志、防火间距、防雷与静电的问题。研究结果对工贸企业构建覆盖危险化学品使用的安全风险管控长效机制具有指导意义。     

Preventing explosions during chemicals and materials storage

Simple passive means are considered for preventing explosions in connection with storage of non-reactive and reactive materials. For high-pressure storage, special attention is given to the elimination of BLEVEs. Cost-effective passive features are proposed to accommodate both global and local fire impingement conditions. For atmospheric pressure storage, passive features are considered to accommodate potential fire exposure and prevent runaway scenarios for reactive systems.     

Mixed Oligopoly and Market Power Mitigation: Evidence from the Colombian Wholesale Electricity Market*

Using information on price bids in wholesale electricity pools and empirical techniques described in the literature on electricity markets, this study identifies the market power mitigation effect of public firms in the Colombian market. The results suggest that while private firms exercise less market power than is predicted by a profit-maximization model, there are marked differences between private and public firms in their exercise of unilateral market power. These findings support the hypothesis of the market power mitigation effect of public firms.     

Using the ASTM CHETAH program in chemical process hazard evaluation

The CHETAH program has proven to be of great utility in the assessment of reactive chemicals hazards associated with the development of new chemicals and chemical processes. At the Dow Chemical Company, the most frequent use of the program is for the estimation of heats of reaction. Reaction heats are often the single most important parameter in reactive chemicals evaluation since most “worst case” scenarios involve the instantaneous liberation of the reaction energy. Another common use of the program is using CHETAH's unique capability to predict the “explosive” behavior of a material or mixture solely from a knowledge of its molecular structure. Several examples of day-to-day use of the program are presented. Current development activity in the ASTM subcommittee which supports CHETAH are discussed. These include new hazard evaluation criteria, better thermodynamic property estimation techniques, and user friendly versions of the program.     

Management of hazardous materials at the local community level

Increasing media visibility, public concern, and restrictive legislation over the effects of chemicals in use by society is creating a range of problems and liabilities that many local jurisdictions are currently unprepared to cope with. Communities around the nation are struggling to develop cost effective, sustainable internal systems to manage their responsibilities for hazardous chemicals which are used, stored, manufactured or transported within their areas of responsibilities. Within the past few years, federal and state legislation has mandated new local responsibilities for management of chemical hazards. The sheer volume of statutes, regulations, guidance and advice available from public and private sources on how to manage these new responsibilities and liabilities can be overwhelming.     

Dynamische Berechnung der Stromgestehungskosten von Energiespeichern für die Energiesystemmodellierung und -einsatzplanung

Due to the transition in energy supply from fossil to renewable energy sources, energy storage systems are getting more and more important for the security of power supply. Therefore also the modeling of those storage systems in energy system modeling needs to be further discussed. This paper focuses on the levelized costs of energy storage. In the beginning, the existing approaches of calculating those costs are analyzed in a literature review. It will be shown that all of the approaches calculate the levelized costs on the basis of the energy storages’ lifetime. For the usage in energy system modeling it is mandatory that the calculation can be done for variable and shorter time periods. Therefore this work’s approach calculates the costs based on the time of operation in any period chosen. Additionally, the model can be used for any type of storage system. After introducing the mathematical model, the levelized costs of energy storage will be calculated to illustrate the models properties and then verified with reference load profiles for five different energy storage types. Following this, particular input parameters are varied and sensitivities are pointed out. Most of the programs for power plant dispatch calculations use linear or mixed integer linear programing algorithms. As the calculation of levelized costs of electricity is non-linear, most programs use fixed values during the whole time of simulation. In this article the integration of the presented approach into a linear optimization program via recursive and shifted calculation is elaborated. Results are presented and discussed.     

Quantifying the costs of a nationwide public safety wireless network

The existing US public safety wireless infrastructure consists of thousands of disparate systems built by separate local agencies. Problems with interoperability, cost, spectral efficiency, and limited functionality plague these systems but could be significantly reduced through the deployment of a single nationwide network that serves all public safety personnel. Two major efforts towards such a nationwide network are the federal-government-only Integrated Wireless Network (IWN) and an FCC-led effort to create a public-private partnership in the 700 MHz band; the future of both projects is uncertain due in part to concerns surrounding cost. This paper presents a model to estimate cost for two fundamental approaches to a nationwide network: a public-safety-only network and a public–private partnership which serves both public safety and commercial subscribers. We apply this general model to four network scenarios which differ in the amount and band of spectrum allocated as well as the number and type of subscribers (public-safety-only versus commercial and public safety) under three traffic scenarios: voice-only, data-only, and voice and data. We demonstrate that the nation's many small systems could be replaced with a single nationwide network with a small fraction of the tower sites and spectrum. The cost of building this new infrastructure is comparable to what is likely to be spent in just a few years on upgrading and maintaining the existing infrastructure. In addition, we show that these cost estimates are highly dependent on some key system design parameters including the public safety capacity required and signal coverage reliability, which must therefore be well-defined in advance.     

Travel time models in automated storage/retrieval systems: A critical review

This paper presents a brief, critical review and a comparative study of some design aspects of automated storage/retrieval systems with special emphasis on travel time models. These aspects include improving throughput rate, changing retrieval sequencing rules, using order batching algorithms, applying various dwell point strategies and increasing the storage/retrieval machine capacity. Some of the results and discussions used in this paper have been adopted from available sources and the rest have been compiled and/or calculated from the recent literature as mentioned therein. A conclusion is made on the salient issues prevailing in the design of automated storage/retrieval systems.     

Neo‐Rawlsian Fringes: A New Approach to Market Segmentation and New Product Development*

Prior research into the link between new product development and market segmentation has focused on two main approaches: (1) design, segment, and do limited competitive evaluation; and (2) segment first, design second. This paper proposes a third approach, which is to simultaneously design, perform segmentation according to benefit and to evaluate against competitive designs. This research uses a benefit segmentation technique based on conjoint analysis (or other techniques that relate product attributes to consumer utility) in which the segments emerge simultaneously with the design based on certain design principles or “strategies.” Herein a method is proposed to narrow down the many possible feasible designs (combinations of attributes) to a finite set and to examine the appeal of each design. Five distinct design strategies are proposed for modeling and studying competitive reaction. These include “traditional” ones such as differentiation and new ones whose fringe customers have high utility. The paper shows that these five strategies are adequate for modeling competitive reaction using simulation. Another contribution of the paper is the way competitive reaction is modeled. In generating and evaluating a design the desire herein is also to assess the defensibility of the design and include it in the evaluation criteria. These issues are addressed by decomposing the solution procedure into two phases. In the first phase, different optimal designs are created based on predefined product development strategies. In the second, these optimal designs are compared against one another with regard to market share and potential to secure market leadership. This work shows that the nature of competition as well as the variability of customer preferences are critical to how a strategy performs. This process uncovers a surprisingly robust design strategy—developing attributes such that a “lower fringe” is most satisfied—that even achieves market dominance under certain conditions. This methodology is also applied to partworth data on refrigerators, which provides a concrete example of the concepts and demonstrates results consistent with the propositions developed earlier in the paper.     

COMPETITION AND COST OVERRUNS IN PROCUREMENT*

Most cases of cost overruns in public procurement are related to important changes in the initial project design. This paper provides a rationale for the observed pattern in public procurement of underinvestment in design specification. We propose a two‐stage model in which the sponsor first decides how much to invest in design specification and auctions the project to horizontally differentiated contractors. After the contract has been awarded and implemented, the sponsor and contractor receive new information about the optimal project design and renegotiate the contract to accommodate changes in the initial project's design. We show that the sponsor's optimal strategy is to underinvest in design specification, which makes significant cost overruns likely. Since no such underinvestment occurs when contractors are not horizontally differentiated, cost overruns are seen to arise as a consequence of lack of competition in the procurement market.     

Environmental research joint ventures among manufactures

This paper explores the reasons that firms form research joint ventures by focusing on a particular type of venture — namely, ventures that are developing new processes to reduce toxic air emissions. The legislative expression of government concern and intent to develop regulations for toxic chemicals prompts firms to join forces in joint ventures that address the problems posed by the chemicals. The cooperative R&D ventures do not appear to be a way for companies to avoid Schumpeterian competitive pressures that stimulate R&D investment. New, primary data at the disaggregated level of a particular type of R&D for particular companies support the belief that cooperative R&D ventures among manufacturing companies may well promote economic efficiency.     

Advertising and Natural Vacancies in Rental Housing Markets

We formulate a model that explains vacancy durations arising from lags in matches between the suppliers and demanders of housing units. We emphasize rental housing markets in this exposition although the model could be extended to competitive or noncompetitive rental or home-ownership markets. In the case of rental markets, if tenants do not immediately inform landlords upon initiating search for a new unit, landlords are delayed in their search for a new tenant. These matching delays induce a positive natural vacancy rate that cannot be reduced to zero, even in competitive markets. Price-taking landlords are, however, able to affect the resulting vacancy duration through advertising in a Cournot-Nash equilibrium and will, in general, invest in inefficient levels of advertising. As a consequence, there may be a role for public policy to provide incentives that would induce noncooperative landlords to choose the vacancy cost-minimizing advertising solution.     

CO2 Speicherung in Deutschland: Eine Brückentechnologie als Klimalösung?

The technology for CO₂ capture, transport and storage (CCTS) in the power plant and industrial sector are considered as an important component in a portfolio of technologies for CO₂ reduction. However, delayed or canceled demonstration projects show that the cost of the capture unit, the necessary pipeline infrastructure and the scarce storage potential in geological formations restrict the CCTS potential. In addition, growing public resistance could lead a further reduction of the CO₂ abatement potential. In this paper the contribution of the CCTS technology for CO₂ reduction in the energy and industrial sectors in Germany is calculated using the model CCTSMOD. It turns out that the application of CCTS is economically interesting for selected industrial sectors under CO₂ certificate prices of 50 €/t and for the power sector under certificate prices of 75 €/t. Because of the limited storage potential, lack of alternative mitigation options and low cost of the deposition, a predominant use of technology in the steel and cement sector is recommended.     

Development of the conceptual model of energy and utility management in textile processing: A soft systems approach

This paper aims to use soft systems methodology (SSM) to identify management support system opportunities for managing energy and utility usage in textile manufacturing processes. It presents an approach based on SSM to analyze the complex situation of developing an effective energy and utility management support system (EUMSS). This involves the identification of the scope of the system and user requirements, conceptual modeling of complex problem situations, identification of actors and decision processes, and information-needs modeling. The current study pioneers the examination of the application of SSM to the development of a novel EUMSS and contributes to the body of information systems knowledge in the context of EUMSS design. There appears to be limited academic research in the field of energy and utility system development and, in particular, in the area of EUMSS design, and none in the area of the application of SSM to EUMSS design. In addition, the modeling process could be beneficial if EUMSS design ideas could be widely shared and discussed. The identified scope and system requirements can serve as a guideline for designing and developing an effective EUMSS for textile processing.     

Public and private intervention for next-generation access deployment: Possibilities for three European countries

How next-generation access (NGA) deployment can be encouraged is a challenge that many countries are facing, and one that has been widely and actively discussed around the globe. This discussion has highlighted a dilemma that ultimately shapes investment—how to encourage the widespread deployment of NGA while enabling operators to achieve reasonable returns. This paper focuses on the tensions that arise as a consequence of this investment challenge in three countries – the Netherlands, Sweden and the United Kingdom (UK) – and uses the analysis of extensive data collection with k7ey actors to argue the case for the injection of public or private incentives. The paper finds that markets with competitive infrastructure will not benefit from public investment while markets with geographical constraints are in need of public support. The paper also explains that regulatory intervention is necessary in the early stage of NGA roll-out, even in currently competitive markets. In all the discussions it becomes evident that, among the three cases, the UK is most in need of public intervention.     

OSHA's interest in chemical plant safety

The Occupational Safety and Health Administration (OSHA) has been required by the Clean Air Act Amendments of 1990 to promulgate a process safety management (PSM) standard for the prevention of catastrophic incidents and to protect the safety and health of employees in the covered plants. The law requires the OSHA standard to cover at least 14 areas or issues and to cover highly hazardous chemicals which include toxic, flammable, highly reactive and explosive substances. The paper will describe in detail how OSHA has responded to this statute and what we have accomplished in the rulemaking effort. Also the interface with other relevant OSHA standards, including the Hazard Communication standard, the Hazardous Waste Operations and Emergency Response standard, the Control of Hazardous Energy Sources (Lockout/Tagout) standard, and others will be discussed. In addition other recent laws that relate to and impact the OSHA PSM standard such as the Hazardous Materials Transportation Uniform Safety Act of 1990, the Oil Pollution Act of 1990, and the Superfund Amendments and Reauthorization Act (SARA) of 1986, will be explained as to their relationship to PSM. The emergency preparedness efforts required of employers under PSM and the relationship to SARA Title III efforts by local community emergency response organization will be covered, as well as the interface with the EPA Risk Management Program initiative that EPA must do under the Clean Air Act Amendments.     

Knowledge work: its evaluation and reward

Abstract . Much conflict arises in Indian research institutions as a consequence of unsatisfactory systems of evaluating and rewarding individual performance. The paper reviews existing systems critically and lays down guidelines for the development of an open consensus system designed to remove objections to current predominantly closed and secret practices. The basis for an evaluation proforma suitable for Indian conditions is put forward; this would include information on current achievement, future potential and personal characteristics with respect to each of the functions (research, teaching, consultancy, etc.) that a knowledge worker might perform. An example of how the various elements could be weighted and combined is also provided. The paper contains advice on the administration of the system to ensure the eventual emergence of a consensus. It concludes with a discussion of the factors to take into account and the problems likely to be met in translating the evaluation results into monetary and non-monetary rewards, based on Maslow's hierarchy of needs.     

Design of the optimal feeding policy in an assembly system

This paper describes an innovative and integrated approach to component management optimization within a production/assembly system. In a mixed-models assembly process the handling of parts and components for each work station represents a substantial variable that can greatly affect job duration and efficiency. This paper is strictly related to Assembly to Order/Manufacturing to Order (ATO and MTO) systems, where lead time has to be very short and flexibility is at its maximum level. In Assembly to Order (ATO) or Make to Order (MTO) systems, the production is increasingly getting more customized in response to the demand, thanks to the progresses reached in both manufacturing and information technologies. It is becoming increasingly possible to assemble or make products specifically in response to the requests of either end customers or retailers. As a consequence of such customization, the design of the whole system must take into direct account several elements: parts warehouses location, feeding policies and feeding systems. In some cases the collection of parts and components required picking activities, in other the movement of entire units load.In several instances experts have analyzed the problems about material centralization/decentralization, storage policies and assembly feeding problem in different and independent ways, while the problem needs an integrated approach. While many researches regarding components allocation problems in ATO and MTO systems, did not consider feeding policies, material picking, packing activities and vehicles optimization, this paper cover focuses on filling such gap using an integrated framework that considers both aspects of the problem: the centralization/decentralization of components in order to minimize the total storage costs and the right feeding policies.Feeding problems in assembly lines are some of the most important aspects to consider during the analysis and design of an assembly system, to allow the maximization of efficiency and flexibility. To reach such goals, a multi-factorial analysis has been carried out during this experiment and will validate the introduced framework. An industrial application of the introduced framework is illustrated to explain its real significant production implication.