Application of genetic algorithms to pattern recognition of defectsin GIS

A computerized pattern recognition system based on the analysis of phase resolved partial discharge (PRPD) measurements, and utilizing genetic algorithms, is presented. The recognition system was trained to distinguish between basic types of defects appearing in gas-insulated system (GIS), such as voids in spacers, moving metallic particles, protrusions on electrodes, and floating electrodes. The classification of defects is based on 60 measurement parameters extracted from PRPD patterns. Classification of defects appearing in GIS installations is performed using the Bayes classifier combined with genetic algorithms and is compared to the performance of the other classifiers, including minimal-distance, percent score and polynomial classifiers. Tests with a reference database of more than 600 individual measurements collected during laboratory experiments gave satisfactory results of the classification process     

Microdischarge activity in vacuum insulating systems with Cu-coatedceramic spacers

This paper presents the measured results of microdischarge activity in a vacuum insulating system after deposition of a Cu layer on a ceramic spacer's surface. The frequency of occurrence vs. charge magnitude characteristics of microdischarges were obtained using a multichannel pulse-height analyzer. The parameters describing microdischarge intensity which were evaluated, included total and maximum charge of microdischarges, number of pulses and average charge of pulse. Relations between microdischarge intensity and voltage as well as time for various thickness of Cu-deposited layers were determined     

Purification and characterization of aPenicillium sp. lipase which discriminates against diglycerides

A lipase was isolated fromPenicillium sp. strain UZLM-4 and characterized. This lipase has a molecular weight of 27,344 (determined by mass spectrometry) and hydrolyzes triglycerides in preference to mono- and diglyceride substrates. Among various triglyceride substrates, tributyrin is hydrolyzed about four times faster than any other tested. The lipase has a preference for hydrolysis at the 1,3 positions of the lipids and shows a weak stereoselectivity for the S enantiomer. Unlike most other lipases, this lipase is stable and has a high activity at low surface pressures (5–10 mN/m).     

Comparing follicle stimulating hormone from two commercial sources for oocyte production from out-of-season dairy goats

Until recently, two sources of follicle stimulating hormone (FSH-P; Schering-Plough; Kenilworth, NJ and Super-Ov; FSH-SOV; AUSA International, Tyler, TX) have been commercially available in the United States and routinely used for superovulation of ruminants. Because there have been no comparative follicle stimulating hormone studies on small ruminants, we determined the difference between the number of follicles induced and the number of oocytes that can subsequently be harvested from goats stimulated with either of these two follicle stimulating hormone products. Anestrous Saanen does were fitted with a progestin implant then randomly assigned to one of two ovarian stimulation groups. Starting 4 d after introducing the progestin implant, donors in treatment 1 were administered daily injections of FSH-P for 4 d. Does in treatment 2 were similarly treated but were administered FSH-SOV for 4 d. Follicle aspirations were performed by laparotomy in the morning of treatment d 8. In summary, no difference was detected between the two stimulatory agents for the number of follicles and quality of oocytes harvested from stimulated does, indicating that these two commercial FSH products could be used successfully for ovarian stimulation of anestrous dairy goats.     

Analysis of glutaminase activity and RNA expression in preimplantation mouse embryos

The efficiency of the American Optical Company (Hardy, Rand and Rittler) (HRR) plates for screening, grading and classifying red-green colour deficiency was examined for 401 male colour deficient subjects previously identified and diagnosed with Nagel anomaloscope. There were 83 protanopes, 30 protanomalous trichromats, 96 deuteranopes and 192 deuteranomalous trichromats. Screening sensitivity was found to be 100% for dichromats and 96.4% for anomalous trichromats based on one screening error (35 subjects, including 7 dichromats, where identified by a single error). Thirty subjects (13.5%) made errors on screening plates only and were identified as having minimal colour deficiency. The HRR grading system did not distinguish dichromats and anomalous trichromats; 54% of dichromats were graded as having moderate rather than severe colour deficiency. Protan/deutan classification was correct for 95% of subjects who failed grading plates. HRR grades for anomalous trichromats were compared with the anomaloscope matching range and with pass or fail of the D15 test. The results show that only two rather than four grading categories can be distinguished by the HRR plates and that both the D15 and the HRR plates are needed in a vocational test battery to establish the severity of colour deficiency.     

Maximation of the signal-to-interference ratio for a doubly spread target: Problems in nonlinear programming

Three optimization problems concerning the maximization of the signal-to-interference ratio for a doubly spread target via signal design are expressed in terms of equivalent nonlinear programming problems defined on a real space by restricting the transmit and processing waveforms to be complex weighted, uniformly spaced pulse trains. Each subpulse can be different in shape and occupy the entire interpulse spacing interval. The approach taken is analogous to the Rayleigh-Ritz technique. The first two optimization problems involve maximization with respect to the complex weights, The third problem involves maximization with respect to the subpulse parameters (e.g., frequency deviation, swept bandwidth, etc.) and allows one to find optimum frequency hop codes.One need not develop algorithms to solve these problems, but rather, one can simply use standard computer programs or methods which are available for solving nonlinear programming problems.     

Redesigning the active site of Geotrichum candidum lipase

Attempts to engineer enzymes with unique catalytic propertieshave largely focused on altering the existing specificitiesby reshaping the substrate binding pockets. Few experimentshave aimed at modifying the configuration of the residues essentialfor catalysis. The difference in the topological location ofthe triad acids of Geotrichum candidum lipase (GCL) and thecatalytic domain of human pancreatic lipase (HPL), despite greatsimilarities in their topologies and 3-D structures, suggestthat these are related enzymes whose catalytic triads have beenrearranged in the course of evolution (Schrag et aL, 1992).In this study we prepared a double mutant GCL in which the catalytictriad acid is shifted to the position equivalent to the locationof the triad acid of HPL. The double mutant maintains 10% ofthe wild type activity against triglycerides and the fluorogenicester 4-methylumbelliferyl-oleate. The only significant differencesbetween the 3-D structures of the double mutant and wild typeGCL are at the mutated sites. Even the water structure in theregion of the triad is unchanged. The hydrogen bonding patternof the catalytic triad of the double mutant is very similarto that of pancreatic lipase. The acid of the double mutantis stabilized by only two hydrogen bonds, whereas three hydrogenbonds are observed in the wild type enzyme. These results stronglysupport the hypothesis that the pancreatic Upases are evolutionaryswitchpoints between the two observed arrangements of the catalytictriads supported by the /ß hydrolase fold and suggestthat this fold provides a stable protein core for engineeringenzymes with unique catalytic properties.     

Simultaneous preferential crystallization in a coupled batch operation mode. Part II: Experimental study and model refinement

In the previous part of this series a parametric study was presented to assess theoretically the performance of a novel crystallizer configuration. Complementary, the present work addresses a comprehensive, systematic experimental examination accompanied by an analysis of some relevant process parameters (mass of seeds, CSD of seeds, starting point for the mother liquor exchange, process duration) of two general concepts for preferential crystallization in which the amino acid threonine dissolved in water was used as a model system. In the first step of investigations, the impact of these process parameters was studied for conventional single batch crystallization. The experimental results are discussed and compared with the theoretical ones. Moreover, a configuration consisting of two coupled crystallization vessels was investigated. The specific manipulation of the concentration profiles of each enantiomer in solution as well as of the temperature profiles was found to be suitable to enhance the process performance. This is reflected by higher achievable process productivities and higher product purities.