The Behaviour of Disperse Dyes at High Temperatures

Investigations on disperse dyes in the vapour phase are described. The various methods of determining the vapour pressure of such dyes at high temperatures are compared. By means of direct spectrophotometric determination, a relation is established between the partial vapour pressure of a disperse dye over its solution in polyester, and its concentration in polyester. It is shown that the heat-fastness properties of such dyes depend on their vapour pressures, any exceptions being due to the instability of the particular dye under the conditions of testing. Finally, the kinetics of such processes are considered and some attempt is made to analyse practical systems.     

TEXTURE IMPROVEMENT OF FRESH-PACK DILL PICKLES BY ADDITION OF LACTOSE AND SUCROSE

The influence of small amounts of lactose or sucrose on texture of fresh-pack dill pickles was evaluated by Instron texture profile analysis (TPA). Pickles were prepared with 0, 2, 4 and 6% by weight of either lactose or sucrose in a commerical brine. After equilibration of pickles with brine (30, 64 and 77 days), TPA values were obtained for brittleness, hardness, elasticity and total work of compression. Analysis of variance for the linear regression showed significant relationships between TPA values and sugar concentration. A minimum of 6% sugar is considered necessary for meaningful texture improvement. Sensory evaluation showed that sweetness may be detectable at the 4% and 6% sucrose levels. The presence of lactose was not objectionable at these levels.     

CHANGING AMERICAN CONCEPTS OF MICROBIOLOGICAL STANDARDS FOR FOODS

A dramatic change has taken place during this century in American attitudes towards microbiological standards. The original concern for public health has been largely alleviated by the success of earlier efforts, and we now see a tendency for applying microbiological standards to measure market quality. Such efforts are frequently arbitrary and not necessarily in the interest of the consumer. It is suggested that microbiological standards be limited to use in safeguarding public health; other standards, if they are to be used, should be voluntary, similar to ASA, USP, ACS, or ASTM standards for various industrial non-food products and processes. Such voluntary standards for microbiological food quality and acceptability could solve many current disputes and contribute to the betterment of the American diet and the American food industry.     

Microstructure of Reaction-Bonded Silicon Nitride Consolidated by Isostatic Hot-Pressing

Reaction-bonded Si₃N₄ specimens which had been isostatically hot-pressed at 1850°, 1950°, and 2050°C were examined microstructurally and by chemical analyses. Previously reported data indicated an increase in the 1200°C bend strength of reaction-bonded Si3N4 only after it was pressed at 2050°C. Observations from the present study indicate that this behavior results from the relative oxygen levels of the isostatically hot-pressed specimens. Calculations show that an Si02 content of 52.2 vol% is required to realize an increase in the 1200°C strength.     

Use of Magnetic Resonance Procedures for Measurement of Oil in French-style Dressings

Magnetic resonance imaging and spectroscopy techniques have been developed for measuring percentage of edible oil in French-style salad dressings. In imaging, one takes advantage of the variations in signal intensities related to differences in relaxation times of the oil and aqueous phases, and of the proportionality of projected frequencies to spatial distribution of sample constituents. In spectroscopy, percentage of oil is determined from standard curves where the integrals of oil/ total spectra are correlated to known amounts of oil in standard preparations. Both procedures permit rapid, nondestructive analysis of commercially packaged dressings in unopened bottles with nonmagnetic closures. Results obtained in imaging or by NMR spectroscopy were within ± 2% of the expected values.     

DIVERGENT PERSPECTIVES ON THE FUTURE OF CLEVELAND'S NEIGHBORHOODS: ECONOMIC,PLANNING, AND SOCIOLOGICAL APPROACHES TO THE STUDY OF NEIGHBORHOOD CHANGE

ABSTRACT: The purpose of this article is to evaluate the degree to which three ecological models can predict the direction of neighborhood change. Three models —the life cycle, arbitrage, and composition—are commonly found in the literature on neighborhood change, but each focuses on a different aspect of this process. To date, researchers have evaluated these models individually, but few have compared their predictive ability. Using census tract data from Cleveland, Ohio, this study conducts a regression analysis to evaluate the efficiency of each model. The lifecycle model had the greatest predictive value, but none of the models performed well. The state of Cleveland's industrial-based economy combined with the diminished federal role in urban development were identified as contributing factors to a declining inner-city environment. The condition of Cleveland's housing market was reflected in the models.     

EFFECTS OF GROWTH REGULATORS ON YIELD AND QUALITY OF MUNGBEAN SPROUTS GROWN IN AN AUTOMATICALLY CONTROLLED CHAMBER

High quality mungbean sprouts are characterized by thick hypocotyls and short roots. In this study, three plant growth regulators (gibberellic acid, ethephon and abscisic acid) were applied to mungbean sprouts during growth in a microprocessor controlled chamber. Ethephon and gibberellic acid treatments produced sprouts having substantially more food value (dry matter, protein, ascorbic acid) per 100 g of mungbeans than the nontreated controls. Single application (10 or 20 ppm) or double application (20 ppm) ethephon treatment improved mungbean sprout quality through its root-shortening and hypocotylthickening effects. The chamber developed in this study eliminated labor and provided a simple, convenient and reproducible sprout growing process. It has potential in small factories or restaurants as well as in the laboratory.