bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalyst explosion: A case history
Authors: De Haven E. S. , Dietsche T. J. 
Published: June 2004

AbstractIn May, 1979, an explosive rupture of a vessel took place during preparation of a catalyst solution at the Pittsburg, California plant of Dow Chemical U.S.A. About fifty contractor employees were injured, including two fatalities. Property damage amounted to two million dollars.The operation consisted of chlorination of powdered iron suspended in an agitated mixture of chlorinated aromatic heterocyclics to produce a ferric chloride solution for use elsewhere. The operation had been subjected to then current reactive chemicals screening tests and to a number of pilot plant runs; these tests and runs did not reveal any potential for explosion. Today's tests, including the CSI‐ARC, properly conducted and analyzed, would have revealed potential difficulties.
Management of quantitative risk assessment in the chemical process industry
Authors: Arendt J. S. 
Published: June 2004

AbstractGrowing concern about the risk of major chemical accidents in the U.S. has led both government and industry to find new ways to identify and evaluate potential hazards. Among the most promising (and misunderstood) approaches is a collection of techniques called quantitative risk assessment (QRA). Adapted primarily from probabilistic risk assessment approaches developed in other industries, the use of QRA is spreading rapidly through the U.S. chemical industry. Of equal importance, legislators and regulatory agencies at the state and federal level are making QRA an integral part of their proposals for mandatory accident prevention measures.This paper summarizes a workshop on QRA that was presented at the International Conference and Workshop on Process Safety Management, sponsored by the AIChE Center for Chemical Process Safety, in Toronto during May 1990. It is based on A Manager's Guide to QRA [1] developed for the Chemical Manufacturers Association. This paper gives an overview of the Guide and discusses important implications concerning the increasing acceptance of QRA as a chemical regulatory tool.
Process safety management within Dupont
Authors: Burk Arthur F. , Smith William L. 
Published: June 2004

AbstractThis paper presents and discusses the principles and essential features of a process safety management system which if practiced and implemented will prevent industrial catastrophes. The importance of the corporate mission/philosophy and of establishing that sense of operating discipline are also discussed. The corporate mission/philosophy provides the leadership and foundation for a process safety management system. Operating discipline is what takes a process safety management effort from a “paper” program to an “action” program!
A comprehensive test method for inline flame arresters
Authors: Roussakis N. , Lapp K. 
Published: June 2004

AbstractThe certification test standards that presently exist for flame arresters are highly inadequate for inline applications. A proper flame arrester test method should ensure that a unit will work with any flame front conditions that it could be exposed to in actual use. When evaluating flame arrester performance, it is just as dangerous to neglect deflagration testing as detonation testing. The comprehensive inline flame arrester test method outlined here involves exposing a unit to the entire flame propagation pressure spectrum. This includes low, medium and high pressure deflagrations as well as overdriven and stable detonations. The test method also takes into account the following factors: flow restriction on the protected side of the flame arrester, flame propagation through a flowing gas, initial system pressure and temperature, and specified gas mixture. Flow restriction on the protected side of the flame arrester has a very significant effect on performance and has not previously been given consideration in flame arrester testing. Besides moving flame front test, endurance burn testing and hydrostatic pressure testing are also discussed here. Major regulatory organizations have recently adopted these findings as the basis for new standards proposed to cover an inline flame arrester test method.
Specification of flame arresting devices for manifolded low pressure storage tanks
Authors: Piotrowski Thomas C. 
Published: June 2004

AbstractThe current regulations and accepted recommended practices relating to the use of mechanical flame arresting devices on low pressure, flammable liquid storage tanks will be reviewed. The applicability of these recommendations to typical manifolded tank and closed piping vapor recovery systems, as opposed to the more common “stand alone”, venting to atmosphere storage tanks, will be examined with particular emphasis on the widely varying service conditions that mechanical flame arresting devices may encounter. The limitations placed on the use of commercially available Factory Mutual Approved and Underwriters Laboratories Listed flame arresters will be explained.
Using thermodynamic availability to determine the energy of explosion
Authors: Crowl Daniel A. 
Published: June 2004

AbstractCurrent methods to determine the thermodynamic energy of explosion are based on the Helmholtz free energy. The Helmholtz free energy represents the maximum work available from a system during a constant temperature process. For many real explosions, the material is initially at a temperature or pressure higher than the ambient environment. Thus, the Helmholtz free energy does not account for all of the energy sources.The thermodynamic availability provides a general approach to determine the maximum work available from any process. Furthermore, the availability provides a much more formal and structured method for performing the calculations.This paper provides the formal basis, demonstrates the application of availabilty using a number of examples, and provides a table of availability data.
The use of spreadsheets in modelling accidental releases of toxic chemicals
Authors: Freeman R. A. , Shaw D. A. 
Published: June 2004

AbstractMany 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.
Chemical accident prevention under the clean air act amendments of 1990
Authors: Craig Matthiessen R. 
Published: June 2004

AbstractThe Clean Air Act Amendments of 1990 enacted recently contain provisions for the prevention of chemical accidents under Title III—Hazardous Air Pollutants. Some of these provisions include: a general duty clause, preparation of a list of substances and thresholds, requirements for the preparation of risk management plans by industry, specific accident prevention regulations, establishment of a Chemical Safety and Hazard Investigation Board, and requirements for the Occupational Safety and Health Administration (OSHA) to promulgate a process safety management standard. These provisions, approaches with respect to process safety management by the Environmental Protection Agency (EPA), and coordination with OSHA will be discussed.
Analysis of titanium/carbon steel heat exchanger fire
Authors: Prine Brenda A. 
Published: June 2004

AbstractIn the past fifteen years two serious titanium fires have occurred at scrap dealer facilities. Both incidents involved the cutting of titanium/carbon steel heat exchangers by scrap metal dealers. This paper reviews the properties of titanium and carbon steel under extreme conditions and the oxy‐acetylene cutting process relevant to its potential for initiating titanium fires. The probable modes of propagation involved in these specific incidents are considered. The formation of low melting eutectic mixtures and the Thermite reaction are both felt to contribute to the incident once initiated. Alternate methods of cutting titanium/carbon steel exchangers are discussed.
Deflagration protection of pipes
Authors: Chatrathi Kris 
Published: June 2004

AbstractThe potential for gas and dust explosions in the process industries has been historically recognized. Potentially explosible materials, both organic and inorganic, are handled in large quantities on a daily basis. These hazardous materials are processed in vessels and/or pipes: that is volumes with small length to diameter (L/D) ratios or volumes with large length to diameter ratios. It has also been historically recognized that explosions have different characteristics in different volumes. This difference becomes critically important when explosion protection methods are being designed.
Mitigation of hazardous emergency release source terms via quench tanks
Authors: Fauske Hans K. , Grolmes Michael A. 
Published: June 2004

AbstractAnalyses and test data indicate that for many hazardous materials the use of a passive quench tank can effictively eliminate airborne releases. New test data on quench tank performance indicate similarities between condensation, absorption and neutralization reactions. Both two‐phase and all‐gas releases are considered.
Predicting and controlling flammability of multiple fuel and multiple inert mixtures
Authors: Hansel James G. , Mitchell John W. , Klotz Herbert C. 
Published: June 2004

AbstractLe Chatelier's Rule is in wide use for predicting the flammability of mixtures with multiple fuels present. The rule does not conveniently handle multiple inerts or elevated temperatures and pressures. This paper describes an alternate method, developed at Air Products, called FLAMCHEKTM, which conveniently handles these variables. This method for predicting flammability is based upon the commonality of the adiabatic flame temperature of a wide variety of fuels at their upper and lower flammable limits. The method, if PC based, can be extended to automatically control the addition of inerts, fuels, or oxidizers in order to avoid flammable conditions. The concept may be extended to more involved applications, such as within an oil well with fuel gas mixtures containing oxygen. In this case, the location from which a gas sample is obtained for analysis (wellhead) may have a different fuel analysis and flammability condition than the location where an explosion is likely to initiate (bottom of well). Hence a correction of the fuels analysis is required.
Acceptable risk—an overview
Authors: Philley Jack O. 
Published: June 2004

AbstractThis paper offers an overview of the concept of acceptable risk. Variations in the definition of risk are addressed as well as criteria for measuring and evaluating risk. Risk acceptance depends on many factors, some of which are highlighted. The myth of zero risk is addressed with relevant examples such as dioxin and the U.S. space program. Practical applications of acceptable risk concepts are discussed, featuring the RISK MATRIX from system safety MIL‐STD‐882. Some sample guidelines and benchmarks are offered.
Disengagement predictions via drift flux correlation vertical, horizontal and spherical vessels
Authors: Sheppard Charles M. 
Published: June 2004

AbstractThe behavior of an open system is modeled. Thus, for special cases, the void fraction is predicted as a function of location and time. The open system may be an open vessel or a vessel with an open relief device. A single governing equation is derived based on combining the material and energy balances with the churn‐turbulent drift flux relationship and assuming no radial gradients. This partial differential equation is not solved. It is, however, bounded by homogeneous and all vapor venting. These special cases are solved. In homogeneous venting the key variable is time. In all vapor venting under pseudo‐steady‐state conditions the key variable is location. The solution of the partial differential equation is also discussed.Under pseudo‐steady‐state and churn‐turbulent conditions, the open system is modeled. The minimum void fractions (corresponding to a maximum liquid inventory) with all vapor venting, for vertical, horizontal, and spherical vessels are predicted and compared. Analytical expressions for the local and average void fractions in a vertical vessel and non‐unity distribution parameters are presented. Void fraction profiles are compared for three cases: 1. vertical cylinders with distribution parameters (Co values) of unity and 1.5, 2. horizontal and vertical cylinders with varying L/D ratios, and 3. spheres with inscribed vertical cylinders having constant gas production to bubble rise ratio (Ψ′ value). The vertical cylinder average void fraction for non‐unity distribution parameters can now be calculated analytically. The horizontal cylinder average void fraction predicted by turning it upright results in an over prediction of at most 4%. The sphere average void fraction predicted via an inscribed vertical cylinder, with the same Ψ′ value, is consistenly high by at most 8%.
New aspects of electrophylic aromatic substitution mechanism: Computational model of nitration reaction
Authors: Sokolov Alexey V. 
Published: June 2004

AbstractSystematic studies of reaction of nitronium with substituted benzenes (Alk‐, X‐Ph‐, CH3O‐, Cl‐, ‐COOCH3, ‐NO2, and other) were performed using semiempirical methods Austin model 1 and Solvation model v. 2.1 (SM2.1). Reaction path and maps of potential energy surface were investigated, including charge and thermodynamic properties of transition states and intermediate σ‐complexes. Main factors of reactivity—deformation energy and orbital and coulomb interaction—were considered by means of energy partitioning procedure, theory of Perturbation of Molecular Orbitals (PMO), etc. Firm correlation between calculated activation barriers and enthalpies of σ‐complex formation was found. It was found that the above‐mentioned factors successfully joined in enthalpy of protonation of aromatic substrates; thus, this parameter appeared to be ideal index of reactivity of arenes in nitration reaction. Coulomb interaction of nitronium and substituent in transition states explained cases of abnormally high reactivity of ortho position (e.g., in substituted biphenyls). © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Kontrolle ohne Löcher — Der Sarbanes‐Oxley‐Act (SOX) und seine Auswirkungen auf die IT‐Sicherheit
Authors: Hammes Sigrid , Kob Timo 
Published: June 2004

AbstractOb KontraG, KWG oder Basel II — kaum eine Vorschrift, die nicht von Sicherheitsberatern und Produktherstellern benutzt wird, um auf die Bedeutung der IT‐Sicherheit im Allgemeinen und die sich aus den Vorschriften zwingend ergebenden Anforderungen im Speziellen zu verweisen. Da kommt mit dem Sarbanes‐Oxley Act (SOX) die nächste Vorgabe gerade recht. Doch was ist dran? Welche Aussagen lassen sich wirklich aus SOX in Bezug auf die IT‐Sicherheit ableiten und für wen sind diese von Belang?
Was ist der „Cash Flow at Risk”︁?
Authors: Hager Peter 
Published: June 2004

AbstractAt‐Risk‐Modelle gehören heute fast schon zur Grundausstattung eines ordentlichen Kaufmanns. Value‐at‐Risk‐Verfahren (vgl. RISKNEWS 02/2004, S. 50 f.) erfreuen sich großer Beliebtheit in der Finanzwelt, da sie der Messung potenzieller Barwertverluste dienen. Für Industrieunternehmen erscheint eine Risiko‐Definition in Form der Abweichung von einem erwarteten Cash Flow praxisnäher als ein potenzieller Barwertverlust.
Stream regulation and nitrogen dynamics in sediment interstices: comparison of natural and straightened sectors of a third‐order stream
Authors: Lefebvre S. , Marmonier P. , Pinay G. 
Published: June 2004

AbstractNitrogen dynamics were studied in the interstitial environment (i.e. hyporheic zone) of a sandy‐bottom stream in a rural landscape. A third‐order stream in Brittany (France) was studied at 11 stations (riffles) to evaluate spatial patterns of water exchange between surface and interstitial habitats. More intensive sampling was conducted in three riffles selected according to their hydrological characteristics. Chemical characteristics (especially nitrogen) and microbial denitrification were studied at 12.5 and 25 cm depth upstream, and 25 cm depth downstream of each riffle. This study confirms that the interstitial habitat of a N‐rich stream acts as a sink for the nitrate‐nitrogen. Experimental manipulation of sediment cores indicates that denitrification is limited by carbon in surface (i.e. benthic) and by nitrate in hyporheic sediments. River regulation increases inputs of fine sediments, modifies river channel location, and generates changes in the spatial patterns of biogeochemical processes, water origins, and hydrologic exchanges. Copyright © 2004 John Wiley & Sons, Ltd.
Acute exposure to gas‐supersaturated water does not affect reproductive success of female adult chinook salmon late in maturation
Authors: Gale William L. , Maule Alec G. , Postera Ann , Peters Mary H. 
Published: June 2004

AbstractAt times, total dissolved gas concentrations in the Columbia and Snake rivers have been elevated due to involuntary spill from high spring runoff and voluntary spill used as a method to pass juvenile salmonids over dams. The goal of this project was to determine if acute exposure to total dissolved gas supersaturation (TDGS) affects the reproductive performance of female chinook salmon late in their maturation. During this study, adult female spring chinook salmon were exposed to mean TDGS levels of 114.1% to 125.5%. We ended exposures at first mortality, or at the appearance of impending death. Based on this criterion, exposures lasted from 10 to 68 h and were inversely related to TDGS. There was no effect of TDGS on pre‐spawning mortality or fecundity when comparing treatment fish to experimental controls or the general hatchery population four to six weeks after exposures. Egg quality, based on egg weight and egg diameter, did not differ between treatment and control fish. Fertilization rate and survival to eyed‐stage was high ( > 94%) for all groups. With the exception of Renibacterium salmoninarum (the causative agent of bacterial kidney disease; BKD), no viral or bacterial fish pathogens were isolated from experimental fish. The prevalence (about 45%) and severity of R. salmoninarum did not differ among the groups or the general hatchery population. We conclude that these acute exposures to moderate levels of gas‐supersaturated water—perhaps similar to that experienced by immigrating adult salmon as they approach and pass a hydropower dam on the Columbia River—did not affect reproductive success of female chinook salmon late in their maturation. These results are most applicable to summer and fall chinook salmon, which migrate in the summer/fall and spawn shortly after reaching their natal streams. Published in 2004 by John Wiley & Sons, Ltd.
Determinants of software volatility: a field study
Authors: Zhang Xiaoni , Windsor John , Pavur Robert 
Published: June 2004

AbstractAlthough technology advances have provided new tools for maintaining software, maintenance costs remain the largest component of software life cycle cost. A basic factor claimed to be one of the driving factors in the cost of maintenance is software volatility. The objective of this research is to investigate the relationship between certain software attributes and software volatility. In this study, software volatility refers to the frequency or number of enhancements per unit of application over a specified time normalized. However, this metric is divided by the number of source lines of code (SLOC) to obtain a measure that takes into account the size of the software application. The research model is built on previous research concerning software volatility. Three factors are examined to determine their influence on software volatility normalized for SLOC: age, software complexity, and software complexity normalized for SLOC. In addition, we introduce the notion that mean time between software enhancements moderates the relationship of age, complexity, and complexity normalized for SLOC with software volatility. A field study at a major corporation allowed for the collection of data from a 13‐year‐time period. These data are used to empirically test the hypotheses presented in this study. As a moderator variable, mean time between enhancements significantly contributes to the explanatory power of a prediction model for software volatility adjusted for SLOC. Software administrators may wish to use the proposed model in their decision‐making plans to control for software costs. Copyright © 2003 John Wiley & Sons, Ltd.
Queering high school biology textbooks
Authors: Snyder Vicky L. , Broadway Francis S. 
Published: June 2004

AbstractAs teachers committed to educating all students, we need to learn more about how instructional materials shape representations of sexuality and gender. Through its insistent deconstruction of the norms that structure practice and belief, queer theory offers perspectives from which science educators can question assumptions embedded in textbooks. This article applies queer theory to analyze eight biology textbooks used in the United States. Specifically, we ask how biology textbooks address sexuality outside the heterosexual norm and if they propagate heteronormative attitudes. The textbooks examined offer deafening silences, antiseptic factoids, socially sanitized concepts, and politically correct binary‐gendered illustrations. In these textbooks, the termhomosexualitywas used only in the context of AIDS where, along with iv drug users, they were identified as an affected group. The pervasive acceptance of heteronormative behavior privileges students that fit the heterosexual norm, and oppresses through omission and silence those who do not. We offer implications for practice to help science educators broaden their perspectives on the constructs of sexuality and gender to construct new ways of knowing and understanding differences in science classrooms and the natural world. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 617–636, 2004