CRITERIA USED BY RESEARCH AND DEVELOPMENT ENGINEERS IN THE SELECTION OF AN INFORMATION SOURCE.

INVESTIGATED THE CRITERIA EMPLOYED BY ENGINEERS IN THE SELECTION OF VARIOUS TECHNICAL INFORMATION CHANNELS IN PROBLEM-SOLVING ENDEAVORS. FOCUSES ON THE RELATIONSHIPS OF CERTAIN CRITERIA IDENTIFIED IN PAST RESEARCH TO SUCH FACTORS AS FREQUENCY OF CHANNEL UTILIZATION AND THE RATE AT WHICH ENGINEERS ACCEPT OR REJECT TECHNICAL INFORMATION RECEIVED FROM SPECIFIC CHANNELS. A DIRECT RELATIONSHIP IS FOUND BETWEEN PERCEIVED ACCESSIBILITY OF INFORMATION CHANNELS AND SEVERAL OBJECTIVE MEASURES OF UTILIZATION, WHEREAS NO DEFINITE SUPPORT IS FOUND FOR THE HYPOTHESIS THAT THE CHANNELS PERCEIVED HIGHEST IN TECHNICAL QUALITY ARE THOSE USED MOST FREQUENTLY. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Initial Temperatures of Zirconia Phase Changes and Solid-Solution Reactions

Mixtures of zirconia with yttria, magnesia, calcia, ceria, and combinations of calcia and magnesia were investigated by X-ray diffraction at temperatures up to 2870°F. The initial stabilizing reactions occurred at temperatures ranging between 900° and 2700°F. Magnesia apparently showed the lowest temperature of initial reaction and yttria the highest. Combinations of calcia and magnesia showed initial solid solution at temperatures lower than calcia but higher than magnesia, although magnesia seemed to be the first to react. Inconclusive evidence indicated that some exsolution occurred in some combinations when temperatures were lowered.     

Changes in Plant community at Foxcote Reservior Following Use of Ferric Sulphate to Control Nutrient Levels

I n an attempt to control planktonic algal growth in I n an attempt to cosntrol planktonic algal growth in Foxcote water supply reservoir, which is supplied by eutrophic waters from the river Great Ouse, ferric sulphate has been used to reduce ortho-phosphate concentrations in the pumped inlet water. Internal recycling of sediment-bound nutrients retarded the expected algal control for almost three years. During the third year, a marked change in the ecology of the reservoir occurred, and planktonic algae were largely replaced by prolific growths of filamentous species and rooted macrophytes. While the changed flora have caused their own problems, the reservoir is now less prone to closure due to intractable water treatment problems.     

Assay Systems and Characterization of Pacific Whiting (Merluccius productus) Protease

Commonly used protease assays and substrates were compared for sensitivity and simplicity in analyzing proteolytic activity in Pacific whiting causing gel weakening of surimi during heat-setting. Assay based on detection of trichloroacetic acid (TCA)-soluble products, using azocasein as substrate, showed highest sensitivity. By that assay, optimal pH of the protease was 5.5, and optimal temperature, 55°. The validity of the assay for measuring activity was confirmed by pH profiles of residual proteolytic and autolytic activities of uncooked surimi. These analyses showed pH profiles similar to those of fish juice with a pH optimum of 5.5.     

Effect of Subcritical Crack Growth on Fracture Toughness and Work-of-Fracture Tests Using Chevron-Notched Specimens

A correlation between the plane strain stress intensity factor K_I , load, and crack extension has been analyzed for constant displacement and constant loading rate experiments, using chevron-notched, four-point-bend specimens. It is assumed that at the beginning of the experiment the chevron triangle tip is not ideally sharp. As loading continues, the crack initially moves with velocity v_t at K_I equal to a threshold value K_t . Maximum crack velocity is reached at K_I= K_IC , the fracture toughness. Depending on the type of material tested, a specific displacement or loading rate must be used to correlate the maximum load with K_Ic . An error in K_IC calculation is estimated if different displacement rates are applied. Repeated loading-unloading work-of-fracture (WOF) experiments generate values related to the resistance of the material to fracture initiation, K_t , only when the crack length approaches 100% of the specimen width. Values related to material's fracture toughness, K_IC are not generated in WOF tests.     

The Production of High-Quality Effluents in Sewage Treatment Using the Biocarbone Process

The Biocarbone process is a new system for water and effluent purification in which biological treatment and physical filtration take place in the same reactor. Because the use of the process for tertiary treatment of sewage effluent had not been fully investigated, a pilot-scale evaluation was undertaken at Severn Trent's Wigston sewage-treatment works. This paper presents the results.
The study corroborates performance information published by the manufacturer. It shows that the process is an alternative to conventional technology for producing fully-nitrified tertiary effluents having low biochemical oxygen demand (BOD) and suspended solids (SS) concentrations.     

Fruit ripening in Vitis vinifera L.: possible relation of veraison to turgor and berry softening

Background and Aims:  Vitis vinifera L. berries exhibit dynamic changes in water relations during development, but the possible connections between water relations, particularly cell turgor pressure ( P ), and ripening have received little attention, and the water relations have been studied by mostly indirect methods.
Methods and Results:  The cell pressure probe was utilized to examine directly the in situ P of cells in the mesocarp. Mesocarp cell P demonstrated a consistent pattern of a high value early in development, followed by a decrease to less than 1.0 bar that was maintained during ripening. Sugar accumulation did not increase significantly until P had declined to less than 1.0 bar. Fruit 'elasticity' was used to evaluate fruit firmness during development. Fruit elasticity changed dynamically and synchronously with P . When growth was prevented with plastic boxes, the decline in cell P was delayed over 14 days, and the onset of skin colour and sugar accumulation was similarly delayed.
Conclusions:  The results show that when the decrease in P was delayed, the onset of ripening was delayed, and, therefore, are consistent with a central role of P in the onset of ripening.
Significance of the Study:  This study showed that boxing preveraison berries similarly delayed P decrease and colour increase in Cabernet Sauvignon berries. Thus, this system may be useful to study the relationship between P and gene expression in developing berries.