805 resultados para Process of construction


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Intestinal pathogens are exposed to various stress conditions during their infectious cycle. Anaerobiosis, one of such hostile condition, is offered by the host within gut and intestinal lumen, where survival, multiplication and entry into intestinal epithelial cells are priority for the invasion of the pathogen. The fumarate reductase (frdABCD), dimethyl sulfoxide (DMSO)-trimethylamine N-oxide (TMAO) reductase (dmsABC), and nitrate reductase (narGHIJ) operons in Salmonella Typhimurium (STM) encode enzymes involved in anaerobic respiration to the electron acceptors fumarate, DMSO, TMAO, and nitrate, respectively. They are regulated in response to nitrate and oxygen availability and changes in cell growth rate. Vitamin B12 (cobalamin) is synthesized by Salmonella Typhimurium only under anaerobic growth conditions used as a cofactor in four known reactions. The deletion of cobS and cbiA genes prevent any form of cobalamin production. In the present study we evaluate the infection of birds by mutants of STM, with the anaerobic respiratory system committed by mutations in the genes: narG, napA, cobS, cbiA, frdA, dmsA, and torC. Virulence was assessed by oral inoculation of groups of one-day-old broilers with 0.1 mL of culture contained 10 8 colony forming units (CFU)/mL or diluted at 10 -3 and 10 -2 of strains mutants of Salmonella Typhimurium. Clinical signs and mortality were recorded over a period of 21 days. In general, the symptoms of chickens infected with the mutant strains were similar to those presenting by control birds. Except for STMNalr cbiA, all showed reduced capacity to cause mortality in comparison with the original strain. The mortality of group of chickens infected with STMNal r △narG, STMNal r △frdA, STMNal r △dmsA and STMNal r △cobS△cbiA showed significant decrease in mortality compared to control group (p<0.05).

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This article aims to present proposals for improvement of key standards and resolutions concerned about the methodology for calculating the indicator of total harmonic voltage distortion, and should contribute to the process of examining the compatibility of potentially disturbing loads in electric power quality in distribution systems. These proposals were drawn from the analysis of results from measurement campaigns conducted in a case study including analysis of the connection of a new induction furnace in a foundry served by a distributor of São Paulo state. A general historical situating the quality of electric energy in the electricity sector is presented, and methodological guidelines and procedures used in experimental trials are shown. The analysis and discussion of results are prepared to answer the main questions that arise during the implementation of standards, resolutions and procedures. © 2011 IEEE.

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This paper presents a methodology and a specialist tool for failure probability analysis of induction type watt-hour meters, considering the main variables related to their measurement degradation processes. The database of the metering park of a distribution company, named Elektro Electricity and Services Co., was used for determining the most relevant variables and to feed the data in the software. The modeling developed to calculate the watt-hour meters probability of failure was implemented in a tool through a user friendly platform, written in Delphi language. Among the main features of this tool are: analysis of probability of failure by risk range; geographical localization of the meters in the metering park, and automatic sampling of induction type watt-hour meters, based on a risk classification expert system, in order to obtain information to aid the management of these meters. The main goals of the specialist tool are following and managing the measurement degradation, maintenance and replacement processes for induction watt-hour meters. © 2011 IEEE.

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The software industry has become more and more concerned with the appropriate application of activities that composes requirement engineering as a way to improve the quality of its products. In order to support these activities, several computational tools have been available in the market, although it is still possible to find a lack of resources related to some activities. In this context, this paper proposes the inclusion of a module to aid in the requirements specification to a tool called Requirements Elicitation Support Tool. This module allows to specify requirements in accordance with IEEE 830 standard, thus contributing to the documentation of the requirements established for a software system, besides supporting the learning of concepts related to the requirements specification, which improves the skills of users of the tool. © 2012 IEEE.

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This study analyses business schools' incorporating environmental management issues into their core activities, defined through teaching, research, outreach and management. Taking into account the relative lack of literature on this theme, case study fieldwork is utilized. Two case studies were conducted at Brazilian business schools. The results were analyzed using the conceptual background of barriers to organizational change, transition to a more sustainable society, and path dependence. The main findings indicate that: (a) the incorporation of environmental management issues tends to begin with researching and teaching; (b) this incorporation process depends on the personal motivation of few or single faculty researchers; (c) the trajectory of the analyzed business schools is marked by advances and stagnation, when analyzing the incorporation of environmental management issues to its four core activities; (d) paradoxically, the analyzed business schools can be considered academic leaders in the field, but have had difficulties in adopting environmental management practices internally; (e) there is a path dependence effect in this process; (f) there are barriers to organizational change towards green business schools; (g) institutional entrepreneurs are important to the process of greening. This research represents the first research shedding light to understanding the process of greening of Brazilian business schools while considering the multidimensional aspects (teaching, research, outreach and university management). © 2013 Elsevier Ltd. All rights reserved.