Inherently safer plants: An update

Instead of adding on protective equipment to control hazards, in an inherently safer plant we avoid them by using less of the hazardous material. Another option is to implement safer alternatives. Though the chemical industry has been slow to adopt such designs there has been some progress.     

Preventing fires and explosions in pilot plants

While the magnitude of potential consequences might vary, most hazards encountered in pilot plant operations are the same as those experienced in full scale commercial facilities. For example, safeguarding hazardous chemicals storage and transfer, protecting reaction vessels against catastrophic failure or runaways, all require careful consideration regardless of scale. We, however, want to address some aspects of pilot plants which can introduce hazards unique or more common to their operation. To illustrate, we present some case histories from our own pilot plant experience in BASF's Chemical Engineering Department, and include a brief discussion of some corresponding safeguards to mitigate these situations.     

A new release of the ASTM CHETAH program for hazard evaluation: Versions for mainframe and personal computer

CHETAH, which stands for the Chemical Thermodynamic and Energy Release Program, was introduced in 1974. Since then, the CHETAH program has been widely used in the chemical industry for hazard evaluation. Although its chief aim is to predict deflagration/detonation potential from molecular structure, it can also be used to estimate heats of reaction, heat capacities, and entropies. One of the limitations of the original program was its rigid, punched card oriented format for data input and the lack of an overall hazard rating derived from the several hazard criteria. A new release of this program alleviates these shortcomings and includes other improvements. The main features of the new release are: 1) a totally interactive front end, 2) an interpreter subroutine which uses sophisticated pattern recognition techniques to combine the four hazard criteria into an overall hazard rating, 3) recognition of certain atomic groupings which are known to be sensitive, 4) correct handling of the symmetry number, and 5) an updated data bank. One of the most important features of this release is its availability in an IBM PC compatible version, making the program accessible to more users.     

BOOK REVIEWS

Dynamics and Conflict in Regional Structura1 Change—Essay in Honor of Walter Isard Volume 2 Practical Methods of Regional Science and Empirical Applications—Selected Papers of Walter Isard, Volume 2 Department of Economics Loughborough University Export Promotion Strategies—Theory and Evidence from Developing Countries Commonwealth Secretariat Export Market Development Division Human Development Report 1990 for the United Nations Development Programme (UNDP) (New York and Oxford: University of Nottingham The World Bank and the Environment—First Annual Report Fiscal 1990, The World Bank (New York: The World Bank, 1990 London Environmental Economics Centre University College London The European Communities' Single Market: The Challenge of 1992 for Sub-Saharan Africa Loughborough University     

Cost and Quality Factors in Parents' Choice of After-School Child Care

The child care choice of parents has been a prime item of policy discussion at all levels of government in recent years. Researchers have responded by examining aspects of cost and quality of care and their implications for the family. One area in which the research effort is in its early stage is after-school child care. This paper presents an attempt to implement a test of a model of child care choice, adapted to after-school care. The results of the implementation are reported and recommendations made for the development of a larger-scale data base.     

Family Composition,Parental Time,and Market Goods: Life Cycle Trade-Offs

The present study supplements Canadian consumer expenditure survey data with unique time use data to analyze family life cycle decisions regarding allocation of full income to market purchased consumption goods, home production, and leisure time. Results confirm that young children's presence causes families to increase their shares of full income allocated to home production and to decrease the shares of full income allocated to leisure. As a share of full income, expenditures for market goods steadily increase while expenditures for women's home production diminish as children age.     

More bang for the buck: Getting the most from accident investigations

An Incident Investigation system based on a combination of Fault Tree Analysis logic and the Deming Principles of Systems and Quality was developed during a three-year period. The system was given an excellent test in the investigation of the explosion of a tank car filled with methacrylic acid. In this case, the Event Tree constructed during the investigation was easily converted into a Fault Tree. The Fault Tree so constructed was then used to evaluate the effectiveness of proposed corrective changes to the production, loading, and analytical systems before the changes were actually implemented. By making use of these tools to guide the addition of feedback loops (“And” Gates in fault Tree terminology), the intrinsic safety of the methacrylic acid production and shipping system was greatly enhanced at a relatively low cost.     

The Impact of Comparative Food Price Information on Consumers and Grocery Retailers: Some Preliminary Findings of a Field Experiment

There is reason to believe that consumers face a difficult task in securing adequate and accurate information upon which to judge relative price levels of competing foodstores. The objective of the research reported here was to investigate the potential of retail food price reporting for correcting this information problem. Both consumer and grocery retailer responses to this comparative food price information were analyzed. A pretest-post-test design with four pairs of experimental-control cities (with replications at two levels of concentration) was employed to collect price data. A modified Solomon-four group design was used for surveys of food consumers in experimental and control cities. The results of analysis of variance models lend support to the hypothesis that price reporting can lower the relative level of food prices, both for items individually identified in a price report and items not identified in the report. The magnitude of this effect varied among the cities. It appears that consumers' role in this experiment was a passive one: consumer behavior and patronage patterns did not change in a manner that would consistently reinforce the competitive effects of the price reports.