Design charts for two-phase flashing flow in emergency pressure relief systems

The design charts of this paper apply to the high velocity flow of a boiling liquid and its vapor during two-phase emergency pressure relief events. These charts are used to size relief system components to handle a given minimum relief flow requirement. This flow requirement is determined by computer simulation programs such as that described in [1], or by special-case models [2, 3, 4]. Though intended for use in sizing pressure relief systems, the charts are applicable to high-velocity flashing flow problems.     

The use of spreadsheets in modelling accidental releases of toxic chemicals

Many hazardous industrial chemicals are stored as liquidfied compressed gases. To evaluate the possible consequences of a pipeline rupture, hose break, or tank puncture, the safety or process engineer needs a means to estimate the two-phase (liquid and gas) flow rate. Recent technical advances by the American Institute of Chemical Engineers Design Institute of Emergency Relief Systems (DIERS) have produced methods that can be used to compute the two-phase flow rate. These methods are simple and can be completed using a personal computer and a standard spreadsheet program such as Excel (Macintosh) or Lotus (DOS based). This paper presents the two-phase flow rate calculation method and shows how spreadsheets can be used for these calculations.     

Managing service innovation: the need for selectivity rather than 'best practice'

In this paper we contrast the notions of best practice and configurations contingent on environmental conditions. The analysis draws upon our study of 38 UK and 70 US service firms. Four system configurations are identified, and the results provide an opportunity for updating the typologies of services, and suggest that practices and performance are multi-dimensional.     

The role of instrumentation and process controls in minimizing accidental releases

Most accidental releases are the result of either mechanical failures or measures taken to prevent such failures, such as, venting through emergency vents, relief valves, or rupture discs. Where the mechanical failure is the result of defective materials, inadequate design, or external factors, little can be done by means of instrumentation to prevent the release. It may be possible, however, to reduce the flow. Many failures are due to process upsets such as overpressure, internal explosions, and runaway reactions. The probability of these failures occurring can be substantially reduced by proper instrumentation.     

Effect of fireproofing design on thermal performance of horizontal members with top flange exposed

It is common practice in the industrial sector to leave the top flanges of fireproofed beams bare. The main reason for this is to permit placement of pipes and grating on the beams without interference from fireproofing materials. To the authors' knowledge, tests of such configurations have not been conducted to determine actual resistance to fire. However, structures fireproofed in this manner have survived actual fire exposures. The purpose of this paper is to examine theoretically the effect of various fireproofing designs on the performance of these members and point out which practices can lead to premature failure of fireproofed beams where top surfaces are left bare. An approximate but practical analytical model is used to evaluate bare steel, encased (concrete/contour) and box (hollow) constructions. The need for reinforcements is demonstrated by examining the effect of bond loss in decomposable systems. Thermal performance is related to load carrying capability of the member.     

The DIERS users group: A forum for development/dissemination of emergency relief system design technology

DIERS was formed in 1976 to develop methods for the design of emergency relief systems capable of handling runaway reactions [1, 2]. Of particular interest at the time were when tow-phase flow venting would occur and the applicability of different methods for sizing emergency relief systems for two-phase, vapor-liquid flashing flow. Approximately $1.6MM was devoted to investigations of two-phase, vapor-liquid onset/disengagement dynamics and the hydrodynamics of emergency relief systems.     

Design of quench system for runaway reactions using bench-scale equipment

Runaway chemical reactions are a potential problem in many sectors of the chemical industry. The typical hazard scenario involves a batch (or semi-batch) chemical reaction where, due to an operator error or instrument failure, the reaction temperature begins to accelerate rapidly. The rise in temperature is, of course, accompanied by a rise in pressure and in order to prevent vessel rupture, some means of protection must be provided. The common approach to overpressure protection in the industry is to fit a relief device to the reactor vessel in question; the device opens at a predetermined pressure and, provided it is sized correctly, the maximum pressure can be kept within acceptable limits. The Design Institute for Emergency Relief Systems (DIERS), organized through the auspices of the AIChE [1], undertook several years of research to develop the methodology for the sizing of relief systems to cope with runaway reactions. The emphasis in industry has changed so considerably since the DIERS work that companies are interested in avoiding the release of chemicals to the environment in addition to preventing equipment damage. This adds considerable complexity to the relief system and must be evaluated with the same thoroughness as the vent design.     

Achieving relational governance effectiveness: An examination of B2B management practices in Taiwan

This study examines the antecedents of relational governance effectiveness in a country context where the prevalence of Confucian values is expected to create a culturally ingrained preference for relational governance. We also explore whether different management practices are better predictors of relational governance effectiveness under different collaborative inter-firm relationship configurations. Results from an analysis of 182 alliance relationships in Taiwan, a dynamic newly developed economy, reveal that, generally, demonstrating trustworthiness, establishing just and fair procedures, and building effective platforms for connectivity are management practices that are good predictors of relational governance effectiveness. The multi-group analysis provided more nuanced insights. The findings suggest that different inter-firm relationship configurations require different subsets of management practices. Building effective platforms for connectivity is a strong predictor of relational governance effectiveness in equity-based alliances with foreign partners. In equity-based alliances with domestic partners, establishing fair and just procedures is emphasized. In contractual alliances with foreign partners, ensuring contractual clarity and building effective platforms for connectivity are found to be facilitators of relational governance effectiveness. Last, contractual alliances with domestic partners seem to rely on a portfolio of management practices encompassing demonstrating trustworthiness, establishing just and fair procedures, and building effective platforms for connectivity.     

Private voluntary standards in the food system: The perspective of major food retailers in OECD countries

The paper examines the main economic and institutional incentives which have driven major OECD food retailers in their use of private voluntary standards and discusses their growing role in shaping the agri-food system. It is based on interviews with quality and safety directors of major OECD retailers and a brief survey of retailers’ actual buyer practices. Though not all retailers are included, these firms account for over 70% of retail food sales in OECD countries. We find that the growing voice of civil society, changing legal and institutional frameworks, increased market concentration and buying power as well as their integration with financial markets has provided the setting for development of private standards. While food safety and quality standards are seen as key to maintaining and improving reputation as well as against legal liabilities, additional standards such as labour, environmental and animal welfare are also gaining ground as strategies for customer loyalty and market shares. The grass-roots retailer move in the harmonization of food safety standards is seen as an initial step towards a global approach to managing the food system, with harmonization of other standards likely in the future. Given their buyer power, these developments can be viewed as a way of governing the food system and will be important for both OECD and non-OECD food and agricultural sector evolution in the coming years.     

Government and food distribution in LDCs: The Turkish experience

Opinions differ over the extent to which governments directly intervene in the actual buying and selling of food products, and thus act as intermediaries. Although private sector intermediaries continue to be the central core of the food distribution system in developing countries, the recent trend has been toward increasing government involvement. Patterns and characteristics of food distribution systems in use differ within developing countries. In this article, these differences are related systematically to the differences in the government environment, and is specifically illustrated by the situation in Turkey. Governmental factors are analyzed to show that differing food distribution practices are the result of the prevailing environmental conditions. The author also suggests that the introduction of certain food distribution insitutions, methods and techniques in developing countries is dependent upon appropriate governmental conditions.     

An overview of emergency relief system design practice

Cost effective loss prevention requires an optimizing strategy to prevent, moderate (relieve) and contain runaway reactions. Ensuring that an emergency relief system design will either avoid or accommodate two-phase vapor-liquid flow is of particular importance. Use of adiabatic runaway reaction test information in combination with digital computer simulation is a powerful method to design an emergency relief system.     

Consumer awareness of organic products in Spain: An application of multinominal logit models

Organically produced foods have shown remarkable industry growth. Even with strict adherence to the production practices and increasing availability, the majority of consumers are still not aware of organically produced alternatives. Awareness of organics does not necessarily translate into actual consumption. Achieving awareness and understanding the linkage between awareness and purchasing organics is fundamental to impacting the demand for organically grown products. This study focuses on the responses of Spanish consumers regarding their state of knowledge about organic foods products. Consumer demographic characteristics, knowledge of enriched foods, and price perceptions are shown to impact awareness and consumption. Multinomial logit models are used to predict probabilities of awareness. Then probit models are estimated to link awareness and the actual consumption of organic foods. Factors impacting both awareness and consumption are explored using simulation methods and the coefficients from the logit and probit models.     

图像浮雕算法及其在防伪印刷中的应用

图像浮雕技术是指通过一种特殊处理,改变二维平面图像中的有效内容、图像边缘或者特定区域的颜色值,增强图像立体显示效果的技术。基于孔斯曲面理论,本研究提出了一种新的矢量图像浮雕算法,即通过矢量线条的局部变形来再现图像雕刻般凹凸效果。实验表明,通过上述方法得到的图像浮雕图案克服了现有算法中固定浮雕角度偏移的缺陷,所表现的浮雕凹凸效果更加细腻,既能达到美观的艺术效果,同时作为一种非常重要的版纹防伪元素在防伪印刷中有着广泛的应用价值。     

Laboratory techniques for the quantitative study of thermal decompositions

Two experimental methods are described for studying thermal decomposition reactions in solids and liquids. The first allows early detection of initial exothermicity, calculation of pseudo kinetic parameters describing subsequent decomposition, and estimation of scale effects on the initial temperature for self-sustaining reaction. The second method yields additional data which provides a basis for relief system design.     

Incremental Automation with Sampling Applied to an Advanced Manufacturing System

Capital budgeting models for project selection have been extensively explored, but relatively little attention has been given to the aspects of post-audit and project control for the projects implemented. This paper examines the area of project control and proposes a method that incorporates post-audit information as an active element in the decision to maintain or terminate an initiated project. Project selection is primarily based on anticipated performance, as determined from the most accurate information available. However, in a sequential decision environment, information that is accurate at one point in time may become inaccurate at another. This paper will show how the Dirichlet distribution can be utilized to formulate appropriately weighted prior probability beliefs, and how these initial beliefs can be updated as we receive post-audit information. To do this, we incorporate categorized cash flow data in a unique Bayesian-based framework. To illustrate the use of the Dirichlet distribution, we present a case study of an actual automation decision for a flexible manufacturing system. This case study also demonstrates how decision strategies can be improved by using post-audit information, when compared with conventional methods.     

Municipal fiber in the United States: A financial assessment

Despite growing interest in broadband provided by municipally owned and operated fiber-to-the-home networks, the academic literature has yet to undertake a systematic assessment of these projects' financial performance. To fill this gap, we utilize municipalities' official reports to offer an empirical evaluation of the financial performance of every municipal fiber project in the U.S. operating in 2010 through 2019. An analysis of the actual performance of the resulting fifteen-project panel dataset reveals that none of the projects generated sufficient nominal cash flow in the short run to maintain solvency without infusions of additional cash from outside sources or debt relief. Similarly, 87% have not actually generated sufficient nominal cash flow to put them on track to achieve long-run solvency. In addition, 73% generated negative nominal cash flow over the past three fiscal years, leaving them poorly positioned to make up their deficits and causing them to fall farther into debt. An assessment based on the net present value of these projects' operating cash flow indicates that 53% of projects would not be on track to breakeven even assuming the theoretical best-case performance in terms of capital expenditures and debt service. Close analysis of these projects’ performance reveals that revenue generation likely plays a more important role in generating cash flow than efficiency in construction costs or operating efficiency.     

淮北矿业集团安全文化的创新与实践

结合煤矿实际,从安全宣传教育、安全文化、安全生产体系3个方面,论述了淮北矿业集团在安全文化建设上的系统谋划、理论创新与具体实践。     

Concerned innovation: The ebb and flow between market and society

This paper examines concerned market innovations i.e. new market configurations which integrate non-economic values and collective concerns. We focus on a specific example of concerned market innovation: the evolution over a ten-year period of a cell phone take-back scheme in a single European country. Adopting a practical constructivist perspective, we note that in the case of concerned market innovation, market configurations are shaped by non-economic values and collective concerns and that, in turn, non-economic values and collective concerns are shaped by market configurations. The analysis of market practices integrating, and at the same time, performing values and concerns, leads us to the conceptualization of a theoretical model which shows that one of the difficulties of realizing concerned market innovations resides in the distinction between market and society.     

An Examination of New Product Development Best Practice

Efforts continue to identify new product development (NPD) best practices. Examples of recognized studies include those by the Product Development and Management Association's Comparative Performance Assessment Study and the American Productivity Quality Center NPD best practices study. While these studies designate practices that distinguish top‐performing companies, it is unclear whether NPD practitioners as a group (not just researchers) are knowledgeable about what represents a NPD best practice. The importance of this is that it offers insight into how NPD practitioners are translating potential NPD knowledge into actual NPD practice. In other words, are practitioners aware of and able to implement NPD best practices designated by noteworthy studies? The answer to this question ascertains a current state of the field toward understanding NPD best practice and the maturity level of various practices. Answering this question further contributes to our understanding of the diffusion of NPD best practices knowledge by NPD professionals, possibly identifying gaps between prescribed and actual practice. Beginning the empirical examination by conducting a Delphi methodology with 20 leading innovation researchers, the study examined the likely dimensions of NPD and corresponding definitions to validate the NPD practices framework originally proposed by Kahn, Barczak, and Moss. A survey was then conducted with practitioners from the United States, United Kingdom, and Ireland to gauge opinions about perceptions of the importance of different NPD dimensions, specific characteristics reflected by each of these dimensions, and the level of NPD practice maturity that these characteristics would represent. The study is therefore unique in that it relies on the opinions of NPD practitioners to see what they perceive as best practice versus prior studies where the researcher has identified and prescribed best practices. Results of the present study find that seven NPD dimensions are recommended, whereas the 2006 Kahn, Barczak, and Moss framework had suggested six dimensions. Among practitioners across the three country contexts, there is consensus on which dimensions are more important, providing evidence that NPD dimensions may be generalizable across Western contexts. Strategy was rated higher than any of the other dimensions followed by research, commercialization, and process. Project climate and metrics were perceived as the lowest in importance. The high weighting on strategy and low weighting on metrics and project climate reinforce previous best practice findings. Regarding the characteristics of each best practice dimension, practitioners appear able to distinguish what constitutes poor versus best practice, but consensus on distinguishing middle range practices are not as clear. The suggested implications of these findings are that managers should emphasize strategy when undertaking NPD efforts and consider the fit of their projects with this strategy. The results further imply that there are clearly some poor practices that managers should avoid and best practices to which managers should ascribe. For academics, the results strongly suggest a need to do a better job of diffusing NPD knowledge and research on best practices. Particular attention by academics to the issues of metrics, project climate, and company culture appears warranted.