Case history examples

An SVE pilot test was conducted at a service station site that had experienced a release of gasoline. Some LNAPL had been removed, but high concentrations of vapor persisted across the site. The site was underlain by silty clay, which overlies weathered and highly fractured shale at a depth of approximately 7 ft. The water table occurs within the upper portion of the shale at a depth of approximately 11 ft. 

The underground tanks at this site were located in a tank hold that extended into the shale. When the release occurred, gasoline migrated downward into the shale and groundwater. Groundwater in the shallow aquifer in this area is not used, due to limited quantity and poor quality, although a significant concern existed due to elevated hydrocarbon vapors. A local basement fire had been attributed to the presence of the vapors. 

Remediation commenced with the interception of the recoverable gasoline. One 4-in.-diameter vapor extraction well and three 2-in. vapor monitor wells were installed. Each well was constructed with 4 ft of well screen placed and filter packed across the unsaturated portion of the shale. The annulus of the wells was sealed to the surface with bentonite and cement grout according to local standards. The monitor wells were located in a triangular pattern around the vapor extraction well at distances of 5.3, 10.6, and 25.4 ft. 

As this is an demonstrative example, only a portion of the data will be discussed here. When the SVE unit was started, the vacuum in the recovery well rapidly 

Soil Vapor Extraction TPH Recovery Results Concentration Recovery Rate  

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Case Histories Following are examples of fatal accidents resulting from lack of oxygen ... 

Correct application of this principle can lead to what would appear to he peculiar recommendations. For example, if just one member of a couple is to be coated, it should be the noble member. Most coating systems leave holidays or tiny openings where the metal is exposed. If the active metal is coated, the area of exposure at the holidays can be quite small compared to the area of the noble metal, resulting in an unfavorable area ratio. On the other hand, if the noble metal is coated, the holidays provide a small cathodic area and hence a highly favorable area ratio with respect to the active metal. Similarly, if dissimilar metal fasteners must be used, they should be noble relative to the metals being fastened (see Case History 16.1). 

Reference 2 gives a case history for a 30-in. line at I3,000gpm, and the author has observed a plant example for a 6-in. line at I45gpm. Both had Froude numbers in the troublesome range and both caused big problems. 

Suits and Bueche conclude their case-histories with a superb analysis of the sources, tactics and uses of applied research, and make the comment The case histories just summarised show, first of all, the futility of trying to label various elements of the research and development process as basic , applied or development . Given almost any definition of these terms, one can find variations or exceptions among the examples. ... 

This outline case-history is an excellent example of a parepisteme which began as a metallurgical curiosity and developed, at a leisurely pace, into a well-understood phenomenon, from which it became, at a much accelerated pace, an important industrial process. 

Very specific forms of low pH localized corrosion may develop in large high heat-flux WT boilers. Where subsequent analysis work is undertaken, the results usually provide the basis for a traceable chain of cause and effect. An example of such a chain of cause and effect is detailed in an interesting corrosion case history provided by Maringer, Saavedra, Selby, and Haberman, and published by Tall Oaks Publishing, Inc. A synopsis is provided below (with kind permission of Tall Oaks Publishing). 

This is the step by step history of the planning and building of a medium size industrial laboratory. The progress and problems involved in this typical case history will serve to illustrate many of the more general or theoretical examples given in previous chapters. 

Types of wood and their chemical resistance and physical characteristics are reviewed, including examples showing the manufacture of typical tank and pipe construction. In-service case histories are included. While this coverage takes you from the Forest to the plants making acetic acid, that is beyond the need for most users it is hoped that the reader becomes aware that this product family is the only MOC for several CPI applications and is a competitive choice over some quite exotic materials, e.g., titanium, in others. 

This book, which incorporates materials written by some of the finest minds in pharmacy practice and education, can enable the reader to play a crucial role in improving the drug use process for patients, providers, payers, and society. The purpose of this book is to help hone your skills so you can make a real improvement in the therapies you provide to your patients. Current and future clinicians can rely on the information laid out here to enhance your knowledge and allow you to assist your patients with the sound advice that they expect you to provide. Use the text, case histories, and numerous examples detailed here to expand your therapeutic skills, and to help positively impact your patients in the years to come. 

This book, combined with its predecessor, forms a resource that is comprehensive in scope and directly applicable to waste management problems in a wide range of industries. Complete with numerous figures, tables, examples, and case histories, this volume provides the clear understanding of the technical and economic concepts needed to develop total environmental control programs that can benefit industry as well as local municipalities. 

One example of the application of in situ electrochemical epr concerns the study of the Kolbe reaction. As was discussed in section 1.3, the Kolbe reaction involves some extremely complex processes and considerable effort has been expended in the search for the identities of the radical intermediates. Evidence for such intermediates remains sparse but one system that has provided such evidence is the electro-oxidation of triphenyl acetic acid (TPA) at a platinum electrode in acetonitrile (Waller and Compton, 1989). The case history of epr in the study of this system is a very good example of the application of the technique to provide details of a reaction mechanism. In... 

Three general situations involving chemical reactivity hazards are described in this section. Examples of significant incidents are given for each situation. Additional case histories are summarized in Appendix A-l,... 

These data contradict a common assumption that a majority of reactive incidents involve chemical reactor vessels. Chemical processing and storage equipment (excluding reactors) and bulk storage drums account for over 65 percent of the equipment involved in reactive incidents. The case histories highlighted throughout Section 3.0 are examples of reactive incidents that did not occur in reaction vessels. 

Refer to Appendix A, Case History 4, for an example cooling tower fire that resulted in over 2 million dollars damage (1997 dollars). 

Valuable case history information can often be exchanged informally during conferences and seminars. This is especially true for those incidents in which litigation is not expected. Additional information on case histories can be found in Chapter 15. Examples of conferences and seminars are the annual AIChE Loss Prevention Symposium and the CCPS 2000 International Conference Process Industry Incidents. Members of the American Chemistry Council have endorsed a policy for sharing information with outside groups, and other industry associations encourage sharing. 

The edternative to a one-to-one confrontation is to involve the whole group or team, as is exemplified by the case history in Box 7.3. This example has been chosen, partly because I have first hand knowledge of the episode, but more particularly because it was handled by an internal manager rather than by an external third party. Not only does It illustrate well the simplicity of the principles involved, it also shows that this sort of intervention can be done perfectly competently by an ordinary manager. Although the procedure is simple, the emotional stress involved in undertaking such a confrontation, and the self-confidence required too, should not be underestimated. 

In the aforementioned chapter in the First Edition Reference 1,1 mentioned, There is no such thing as a standard approach to solve compactor scale-up or compactor equipment changes in the pharmaceutical production process (1). At that time of the publication, it appeared that was very much the case history of roller compaction scale-up in the pharmaceutical industry. This understanding was based on the fact that there were no pharmaceutical industrial journal articles published at the time on the subject. On the other hand, it was also true that considerations, approaches, and examples presented in that chapter were experienced by others and were not all-inclusive. 

As an example on the interpretation of survey data and proposal focus, a case history is presented. 

Progress was not smooth mistakes were made, decisions took considerable time to be made, and the early trial results were not spectacular. In fact, this case history mirrors the kinds of real-life problems that water treatment buyers and sellers often experience, especially with large accounts. However, fortunately, most plant surveys are not this complicated, nor do they involve cooling systems anywhere near as large as this example. 

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