Selecting Pesticides and Nonchemical Alternatives: Green Thumbs' Rules of Thumb Decision Tools

This study of a sample of home gardeners indicates that rules of thumb, or heuristics, are used to select between chemical pesticides and nonchemical alternatives. Such rules of thumb serve to simplify otherwise complicated choice decisions. Heuristics commonly used to choose pesticides include how safe, effective, efficacious, and economical they are, whereas for alternative products consumers more often take into account convenience, efficiency, competency, and handiness. Generally, in an overall ranking of 24 individual choice attributes, pesticies rank low on these attributes where alternatives rank high and vice versa. Gender, age, and years using pesticides are significantly correlated with pesticide selection.     

CENTRAL GOVERNMENT BUDGET DEFICITS AND EX ANTE REAL LONG TERM INTEREST RATES IN ITALY: AN EMPIRICAL NOTE FOR 1955-1989

This paper empirically investigates the impact of central government budget deficits upon interest rates in Italy. The period studied runs from 1955 to 1989, and annual data are used. The interest rate measure is the ex ante real rate of interest. It is found, using an instrumental variables technique to control for the endogeneity of the budget deficit, that the budget deficit raises the ex ante real interest rate in Italy.     

WICKSELL'S INFLATIONARY CREDIT CYCLE

The credit cycle implicit in Wicksell's upward cumulative process (UCP) is described. UCP may be interpreted as a stable cycle with two phases and an upper turning point corresponding to the maximum 2-rate-differential. The volume of credit and the rate of inflation is shown to expand in phase 1 and to contract in phase 2. The role of velocity increasing in causing a higher inflation rate is also described. This cycle has not been noticed in the literature because Lectures(2) was unclear about how long it would take to reach an upper turning point. But, Interest and Prices emphasized that the continuous return of the inflation rate to zero equilibrium would begin after a relatively short period.     

Structured packings for use in oxygen service: Flammability considerations

Metallic structured packings have found increasing use in the cryogenic distillation of air. An experimental program was performed to test the flammability of selected metal packings under simulated high oxygen concentration operating conditions. Aluminum flammability in gaseous oxygen has been shown to be very dependent upon argon dilution, and in the presence of liquid oxygen, strong energy releases have been observed. Brass packing exhibited an unexpectedly high relative flammability whereas copper has been found to be non-flammable in all tested oxygen purities. These findings suggest the use of copper structured packing in higher purity GOX/LOX regions of an air separation distillation column and aluminum structured packing in the remainder of the column.     

An approach to evaluate the acute impacts from simulated accidental releases of chlorine and ammonia

The manner in which specific chemicals are used is studied in order to identify plausible release scenarios and the probability of their occurrence.     

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.