Technological prediction as a means of identifying additional competitive advantages of a specific production process

Results are presented from predictions of the quality indices of metal products used in critical applications. The predictions are obtained for combinations of technological factors that are not used in the actual production process. The reliability of the predictions is confirmed by the fact that the index values obtained with the use of regression models agree with the values obtained using corresponding genetic algorithms. The advantages of the methodology described in the article are demonstrated using the example of analysis of the multi-stage cold rolling of tubes made of zirconium alloys. The introduction of procedures for making technological predictions will help make production processes more efficient and, thus, more competitive. __________ Translated from Metallurg, No. 2, pp. 31–36, February, 2007.     

Heat transfer enhancement by oscillatory perturbation of a stable separated flow

Numerical and experimental results for laminar flow and forced convection in a grooved channel indicate that significant heat transfer enhancement is possible by appropriately-tuned modulation of a steady, separated flow. The frequency r response of the enhancement is strongly peaked around the frequency of the least stable (decaying) mode of the unmodulated flow, suggesting that a simple resonance phenomenon is responsible for the transport augmentation.     

General solution of one-dimensional,time dependent coupled heat flow systems

A new, powerful method of analysis, involving the combined use of finite integral transform and finite element techniques, is presented for the solution of time dependent heat flow systems composed of many one-dimensional elements connected through the nodes. This method leads to an eigenvalue problem which is not of the conventional Sturm-Liouville type. A procedure for the determination of the eigenvalues is described. The solution obtained is in the form of an infinite series and contains quasi-steady and transient terms. The general solution obtained can be applied in the mathematical modelling of many engineering applications such as the determination of the penetration of the daily temperature cycle into buildings, the analysis of heat transfer in array of extended surfaces in compact heat exchangers, and many others.     

Gamma-Irradiation of Frozen Kiwifruit Pulp

Frozen (–18°C) de-seeded kiwifruit pulp (Actinidia deliciosa) was irradiated at a dose of 100 krad and stored at -18°C. Irradiation resulted in a 2.11 log₁₀ reduction in aerobic plate count (APC) with bacteria being most susceptible. Molds were less susceptible than yeasts. Assessments carried out over 6 months storage showed no significant differences in physical, chemical and sensory properties between irradiated and nonirradiated pulps. The microbial populations of the pulps decreased in parallel throughout the storage period. Frozen storage without irradiation resulted in a 3 log₁₀ reduction in APC over the 6 months period, a 38% reduction in ascorbic acid, and a slight loss of color. Three days frozen storage (– 18°C) following irradiation resulted in an APC only 0.89 log₁₀ higher than 6 months frozen storage (- 18°C) without irradiation with potential savings in energy and holding times which could have economic benefits.     

Effect of vitamins A, E and K on the indices of the glutathione antiperoxide system in gingival tissues in periodontosis

Glutathione reductase is activated and the content of glutathione sulfhydryl groups is increased in the gingival tissue of patients afficted with parodontosis. The degree of alterations depends on the degree of the development and character of the disease. Application of antioxidant vitamin therapy (vitamins A, E and K) locally and per os normalizes the parameters under study and improves the status of the parodontium.     

Dominant negative alleles of SEC10 reveal distinct domains involved in secretion and morphogenesis in yeast

The accurate targeting of secretory vesicles to distinct sites on the plasma membrane is necessary to achieve polarized growth and to establish specialized domains at the surface of eukaryotic cells. Members of a protein complex required for exocytosis, the exocyst, have been localized to regions of active secretion in the budding yeast Saccharomyces cerevisiae where they may function to specify sites on the plasma membrane for vesicle docking and fusion. In this study we have addressed the function of one member of the exocyst complex, Sec10p. We have identified two functional domains of Sec10p that act in a dominant-negative manner to inhibit cell growth upon overexpression. Phenotypic and biochemical analysis of the dominant-negative mutants points to a bifunctional role for Sec10p. One domain, consisting of the amino-terminal two-thirds of Sec10p directly interacts with Sec15p, another exocyst component. Overexpression of this domain displaces the full-length Sec10 from the exocyst complex, resulting in a block in exocytosis and an accumulation of secretory vesicles. The carboxy-terminal domain of Sec10p does not interact with other members of the exocyst complex and expression of this domain does not cause a secretory defect. Rather, this mutant results in the formation of elongated cells, suggesting that the second domain of Sec10p is required for morphogenesis, perhaps regulating the reorientation of the secretory pathway from the tip of the emerging daughter cell toward the mother-daughter connection during cell cycle progression.     

The influence of selenium and neuroleptics on the rat brain nuclear regulatory mechanism in carcinogenesis

alpha-Crystallins possess molecular chaperone properties and are one of the most abundant of the lenticular proteins. Posttranslational modifications of these proteins have been implicated as a possible etiology of human cataracts. This article will review current knowledge concerning the effects of known posttranslational modifications upon the molecular chaperone properties and aggregation behavior of alpha-A and alpha-B crystallin. Based upon these effects, experimental approaches will be discussed that may be useful in the development of reagents that may selectively inhibit the cataractogenic process in the aging human lens.     

Near-field optical imaging of unstained bacteria: comparison with normal atomic force and far-field optical microscopy in air and aqueous media

Simultaneous near-field scanning optical and atomic force imaging of bacteria is presented. The bacteria imaged in these studies were unstained. The near-field optical images had excellent signal-to-noise and showed excellent contrast even in these unstained specimens. The images obtained were interpreted in terms of the images that have been obtained by transmission electron microscopy and X-ray imaging. The results show that bacterial near-field optical imaging is going to be a very important tool in the arsenal of the bacteriologist both in terms of understanding the fundamental processes in the life cycle of bacteria with and without cytochemical staining and in terms of clinical diagnostic applications.