996 resultados para Industrias Organización, control, etc.
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There is an interest to create zinc/tin alloys to replace cadmium as a corrosion protective coating material. Existing aqueous electroplating systems for these alloys are commercially available but have several limitations. Dangerous and highly toxic complexing agents are uses e.g. cyanides. To overcome these problems, ionic liquids could provide a solution to obtain an alloy containing 20 to 30% of zinc. Ionic liquids (ILs) often have wider electrochemical windows which allow the deposition of e.g. refractive metals that can not be deposited from aqueous solutions. In ILs it is often not necessary to add complexing agents. The Zn/Sn alloy deposition from ILs is therefore a promising application for the plating industry. Nevertheless, there are some issues with this alternative for aqueous systems. The degradation of the organic components, the control of the concentration of two metals and the risk of a two phase deposition instead of an alloy had to be overcome first. It is the main purpose of this thesis to obtain a Zn/Sn alloy with 20% zinc using ILs as an electrolyte. First a separate study was performed on both the zinc and the tin deposition. Afterwards, an attempt to deposit a Zn/Sn alloy was made. An introduction to a study about the electrodeposition of refractive metals concludes this work. It initiated the research for oxygen-free ILs to deposit molybdenum or tungsten. Several parameters (temperature, metal source and concentration, organic complexing agents,) were optimized for both the zinc, tin and zinc/tin deposition. Experiments were performed both in a parallel plate cell and a Hull cell, so as to investigate the effect of current density as well. Ethaline200 was selected as electrolyte. As substrate, brass and iron were selected, while as anode a plate of the metal to deposit was chosen, tin for the alloy. The best efficiencies were always obtained on brass; however the iron substrate resulted in the best depositions. A concentration of 0.27M ZnCl2, 0.07M SnCl2 with 0.015M of K3-HEDTA as complexant resulted in a deposition containing the desired alloy with the amount of 20% zinc and 80% tin with good appearance. Refractory metals as molybdenum and tungsten cannot be electrodeposited from aqueous solutions without forming a co-deposition with Ni, Co or Fe. Here, ILs could again provide a solution. A first requirement is the dissolution of a metal source. MoO3 could be suitable, however there are doubts about using oxides. Oxygen-free ILs were sought for. A first attempt was the combination of ZnCl2 with chlormequat (CCC), which gave liquids below 150C in molar ratios of 2 : 1 and 3 : 1. Unfortuna tely, MoO3 didnt dissolve in these ILs. Another route to design oxygen-free ILs was the synthesis of quaternary ammonium salts. None of the methods used, proved viable as reaction time was long and resulted in very low yields. Therefore, no sufficient quantities were obtained to perform the possible electrochemical behavior of refractive metals.
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Objectives - Review available guidance for quality assurance (QA) in mammography and discuss its contribution to harmonise practices worldwide. Methods - Literature search was performed on different sources to identify guidance documents for QA in mammography available worldwide in international bodies, healthcare providers, professional/scientific associations. The guidance documents identified were reviewed and a selection was compared for type of guidance (clinical/technical), technology and proposed QA methodologies focusing on dose and image quality (IQ) performance assessment. Results - Fourteen protocols (targeted at conventional and digital mammography) were reviewed. All included recommendations for testing acquisition, processing and display systems associated with mammographic equipment. All guidance reviewed highlighted the importance of dose assessment and testing the Automatic Exposure Control (AEC) system. Recommended tests for assessment of IQ showed variations in the proposed methodologies. Recommended testing focused on assessment of low-contrast detection, spatial resolution and noise. QC of image display is recommended following the American Association of Physicists in Medicine guidelines. Conclusions - The existing QA guidance for mammography is derived from key documents (American College of Radiology and European Union guidelines) and proposes similar tests despite the variations in detail and methodologies. Studies reported on QA data should provide detail on experimental technique to allow robust data comparison. Countries aiming to implement a mammography/QA program may select/prioritise the tests depending on available technology and resources.
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Recentemente, tem-se assistido utilizao de ambientes imersivos 3D em vrios domnios tais como: actividades empresariais, educativas, ldicas, entre outras devido expanso do Second Life. A finalidade deste conceito oferecer aos utilizadores um acesso alternativo a valncias existentes no mundo real, a partir de um computador ligado Internet. Uma aplicao prtica pode ser a sua utilizao em laboratrios remotos, com a finalidade de controlar remotamente instrumentos de medio, a partir de um ambiente imersivo. Para isso, o mesmo deve permitir a construo de um laboratrio virtual e respectivos instrumentos, tambm virtuais. Este tipo de soluo vivel, devido a existirem dispositivos com interfaces de acesso remoto, e ambientes 3D desenvolvidos em linguagens de programao que possuem bibliotecas de cdigo para protocolos de redes de computadores. A finalidade deste trabalho desenvolver uma metodologia de acesso remoto, a instrumentos de medio em laboratrios de electricidade e electrnica, usando ambientes imersivos 3D. Como caso de estudo, o instrumento utilizado um multmetro, controlado remotamente a partir de uma reproduo num mundo virtual, construdo no ambiente 3D Open Wonderland. Nessa reproduo virtual, numa primeira fase, s sero disponibilizadas para medio, um conjunto limitado das variveis elctricas passveis de medir atravs do multmetro seleccionado.
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Mestrado em Contabilidade Analtica e Financeira
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A implementao e venda de robs autnomos tem sido um sector que nos ltimos anos tem adquirido cada vez mais quota no mercado, nomeadamente no sector militar, agrcola e da vigilncia. Como tal, tem sido tambm de grande importncia a capacidade de implementar e testar robs por parte das entidades que os fabricam. Uma das formas que tem garantido o sucesso do desenvolvimento de robs a simulao prvia dos mesmos antes que estes passem a fase de produo. Sendo assim, o LSA como entidade de desenvolvimento de robs autnomos, tem necessidade de adquirir um sistema que simule os robs em desenvolvimento. O trabalho desta tese consiste na realizao de um sistema que simule robs autnomos terrestres de forma que se possa observar o comportamento da cinemtica, dinnica e hardware dos robs em ambiente 3D. Esta aplicao de simulao pode mais tarde ser utilizada pelo laboratrio para testar misses, validar alteraes de estrutura, sensores, etc. Para alm disso, com recurso ao simulador Player/Stage/Gazebo testar o rob LINCE e implementar algoritmos de controlo para o mesmo. Os algoritmos de controlo implementados baseiam-se em primitivas de controlo bsico para serem utilizadas pelo sistema de navegao e gerar trajectrias complexas. Os algoritmos desenvolvidos nesta tese baseiam-se nas equaes cinemticas do veculo estudado. Estes algoritmos depois de testados no simulador, podero ser colocados no Hardware do rob. Desta forma consegue-se desenvolver algoritmos para determinado rob sem que este esteja operacional.
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OBJECTIVE: To assess the relationship between locus of control and knowledge, attitude and practice regarding pill and condom use among university students. METHODS: The inquiry was developed in Campinas, a city in Southeastern Brazil, in 2006. A total of 295 adolescent newcomers to a public university answered a structured questionnaire and Levenson's multidimensional locus of control scale. The scores of the dimensions of locus of control were calculated and Spearman's correlation coefficient was used to assess their correlation with knowledge and practice concerning pill and condom use. In order to assess the relationship between the dimensions of locus of control and sociodemographic variables and variables related to the individuals' sex life, Kruskal-Wallis and Mann-Whitney tests were used. RESULTS: Male adolescents had higher scores of powerful others externality when compared to female adolescents (p=0.01). Students living alone had lower internality (p=0.01). When locus of control was compared to condom use in the first intercourse, considering only the 102 students who informed the age of the beginning of sexual activity, greater internality was found among male adolescents who did not use condoms (p<0.05). When the locus of control scores were correlated with contraceptive knowledge and practice, it was found that the higher the powerful others externality locus, the lower the adequate use of contraceptive methods (r = -0.22, p=0.03). CONCLUSIONS: The powerful others externality locus influences the practice of contraceptive use in this group of adolescents.
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Este trabalho de pesquisa e desenvolvimento tem como fundamento principal o Conceito de Controlo por Lgica Difusa. Utilizando as ferramentas do software Matlab, foi possvel desenvolver um controlador com base na inferncia difusa que permitisse controlar qualquer tipo de sistema fsico real, independentemente das suas caractersticas. O Controlo Lgico Difuso, do ingls Fuzzy Control, um tipo de controlo muito particular, pois permite o uso simultneo de dados numricos com variveis lingusticas que tem por base o conhecimento heurstico dos sistemas a controlar. Desta forma, consegue-se quantificar, por exemplo, se um copo est meio cheio ou meio vazio, se uma pessoa alta ou baixa, se est frio ou muito frio. O controlo PID , sem dvida alguma, o controlador mais amplamente utilizado no controlo de sistemas. Devido sua simplicidade de construo, aos reduzidos custos de aplicao e manuteno e aos resultados que se obtm, este controlador torna-se a primeira opo quando se pretende implementar uma malha de controlo num determinado sistema. Caracterizado por trs parmetros de ajuste, a saber componente proporcional, integral e derivativa, as trs em conjunto permitem uma sintonia eficaz de qualquer tipo de sistema. De forma a automatizar o processo de sintonia de controladores e, aproveitando o que melhor oferece o Controlo Difuso e o Controlo PID, agrupou-se os dois controladores, onde em conjunto, como poderemos constatar mais adiante, foram obtidos resultados que vo de encontro com os objectivos traados. Com o auxlio do simulink do Matlab, foi desenvolvido o diagrama de blocos do sistema de controlo, onde o controlador difuso tem a tarefa de supervisionar a resposta do controlador PID, corrigindo-a ao longo do tempo de simulao. O controlador desenvolvido denominado por Controlador FuzzyPID. Durante o desenvolvimento prtico do trabalho, foi simulada a resposta de diversos sistemas entrada em degrau unitrio. Os sistemas estudados so na sua maioria sistemas fsicos reais, que representam sistemas mecnicos, trmicos, pneumticos, elctricos, etc., e que podem ser facilmente descritos por funes de transferncia de primeira, segunda e de ordem superior, com e sem atraso.
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OBJECTIVE: To investigate the relationship between physical activity during the second trimester pregnancy and low birth weight, preterm birth, and intrauterine growth restriction. METHODS: Case-control study including 273 low birth weight newborns and 546 controls carried out in the city of So Paulo, Southeastern Brazil, in 2005. Low birth weight cases were grouped into two subsamples: preterm birth (n=117) and intrauterine growth restriction (n=134), with their related controls. Information was collected by means of interviews with mothers shortly after birth and transcription of medical records. Data were analyzed using conditional multiple and hierarchical logistic regression. RESULTS: Light physical activity for over 7 hours per day was shown to be protective against low birth weight (adjusted OR=0.61; 95% CI 0.39-0.94) with a dose-response relationship (p-value for trend=0.026). A similar trend was found for intrauterine growth restriction (adjusted OR=0.51; 95% CI 0.26-0.97). Homemaking activities were associated as a protective factor for both low birth weight and preterm birth (p-value for trend=0.013 and 0.035, respectively). Leisure-time walking was found to be protective against preterm birth. CONCLUSIONS: Mild physical activity during the second trimester of pregnancy such as walking has an independent protective effect on low birth weight, preterm birth, and intrauterine growth restriction.
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Este trabalho uma anlise dos efeitos da implementao das ltimas recomendaes do Basel Committee on Banking Supervision (BCBS) tambm conhecidas como o Basel III de 2010 que devero ser faseadamente implementadas desde 1 de Janeiro de 2013 at 1 de Janeiro de 2019, no capital prprio dos bancos Portugueses. Neste trabalho assume-se que os ativos pesados pelo risco de 2012 mantm-se constantes e o capital ter de ser aumentado segundo as recomendaes ano aps ano at ao fim de 2018. Com esta anlise, pretende-se entender o nvel de robustez do capital prprio dos bancos Portugueses e se os mesmos tm capital e reservas suficientes para satisfazer as recomendaes de capital mnimo sugeridas pelo BCBS ou caso contrrio, se necessitaro de novas injees de capital ou tero de reduzir a sua atividade econmica. O Basel III ainda no foi implementado em Portugal, pois a Unio Europeia est no processo de desenvolvimento e implementao do Credit Requirement Directive IV (CRD IV) que uma recomendao que todos os bancos centrais dos pases da zona Euro devero impor aos respetivos bancos. Esta diretiva da Unio Europeia baseada totalmente nas recomendaes do Basel III e dever ser implementada em 2014 ou nos anos seguintes. At agora, os bancos Portugueses seguem um sistema com base no aviso 6/2010 do Banco de Portugal que recomenda o clculo dos rcios core tier 1, tier 1 e tier 2 usando o mtodo notaes internas (IRB) de avaliao da exposio do banco aos riscos de crdito, operacional, etc. e onde os ativos ponderados pelo risco so calculados como 12,5 vezes o valor dos requisitos totais de fundos calculados pelo banco. Este mtodo baseado nas recomendaes do Basel II que sero substitudas pelo Basel III. Dado que um dos principais motivos para a crise econmica e financeira que assolou o mundo em 2007 foi a acumulao de alavancagem excessiva e gradual eroso da qualidade da base do capital prprio dos bancos, importante analisar a posio dos bancos Portugueses, que embora no sejam muito grandes a nvel global, controlam a economia do pas. Espera-se que com a implementao das recomendaes do Basel III no haja no futuro uma repetio dos choques sistmicos de 2007. Os resultados deste estudo usando o mtodo padro recomendado pelo BCBS mostram que de catorze bancos Portugueses includos neste estudo, apenas seis (BES, Montepio, Finantia, BIG, Invest e BIC) conseguem enquadrar nas recomendaes mnimas do Basel III at 1-1- 2019 e alguns outros esto marginalmente abaixo dos rcios mnimos (CGD, Ita e Crdito Agrcola).
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Electroanalytical methods based on square-wave adsorptive-stripping voltammetry (SWAdSV) and flow-injection analysis with square-wave adsorptive-stripping voltammetric detection (FIA-SWAdSV) were developed for the determination of fluoxetine (FXT). The methods were based on the reduction of FXT at a mercury drop electrode at -1.2 V versus Ag/AgCl, in a phosphate buffer of pH 12.0, and on the possibility of accumulating the compound at the electrode surface. The SWAdSV method was successfully applied in the quantification of FXT in pharmaceutical products, human serum samples, and in drug dissolution studies. Because the presence of dissolved oxygen did not interfere significantly with the analysis, it was possible to quantify FXT in several pharmaceutical products using FIA-SWAdSV. This method enables analysis of up to 120 samples per hour at reduced costs.
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OBJETIVO: Analizar medidas municipales implementadas para el control de la epidemia del dengue, sobretodo las de coordinacin sectorial, gobernanza y participacin de grupos sociales. MTODOS: Estudio de observacin, realizado en Morelos, Mxico, 2007. Los datos colectados en entrevistas y observaciones directas fueron sometidos a anlisis de contenido y mapeo poltico. El software Policy Marker fue utilizado para evaluar los pesos atribuidos a los datos de desempeo (e.g. criterios alto, medio y bajo) y el papel de actores (acciones realizadas sean ellas de vigilancia, control o administrativas). Se realiz anlisis estratgico de las oportunidades y desafos en el cumplimiento de las polticas pblicas y control del dengue. RESULTADOS: Las bases jurdicas indican que la respuesta a la epidemia es una tarea multisectorial. Sin embargo, la respuesta est centrada en actividades de los servicios de la salud, que estn forzados a dar mayor apoyo financiero y derivar los recursos humanos necesarios, en contraste con la contribucin de otros sectores (e.g. agua y saneamiento bsico), que desconocen sus responsabilidades. El sector de la salud presenta alto nivel de factibilidad para la vinculacin intra?institucional, en trminos de optimizacin de recursos y cumplimiento de objetivos, particularmente entre autoridades de salud en los niveles estatal, jurisdiccional, municipal y local. CONCLUSIONES: El abordaje multidisciplinario y el fortalecimiento de las responsabilidades polticas permitirn la respuesta eficaz ante la epidemia del dengue, sustentada en la coordinacin sectorial e involucramiento activo de la poblacin afectada.
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Celiac disease (CD) is an autoimmune enteropathy, characterized by an inappropriate T-cell-mediated immune response to the ingestion of certain dietary cereal proteins in genetically susceptible individuals. This disorder presents environmental, genetic, and immunological components. CD presents a prevalence of up to 1% in populations of European ancestry, yet a high percentage of cases remain underdiagnosed. The diagnosis and treatment should be made early since untreated disease causes growth retardation and atypical symptoms, like infertility or neurological disorders. The diagnostic criteria for CD, which requires endoscopy with small bowel biopsy, have been changing over the last few decades, especially due to the advent of serological tests with higher sensitivity and specificity. The use of serological markers can be very useful to rule out clinical suspicious cases and also to help monitor the patients, after adherence to a gluten-free diet. Since the current treatment consists of a life-long glutenfree diet, which leads to significant clinical and histological improvement, the standardization of an assay to assess in an unequivocal way gluten in gluten-free foodstuff is of major importance.
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The purpose of the present work is to determine the antioxidant capacity (AC) of 27 commercial beers. The AC indicates the degree of protection of a certain organism against oxidative damage provoked by reactive oxygen and nitrogen species. Assays were carried out by the following methods: (i) total radical trapping antioxidant parameter (TRAP); (ii) trolox equivalent antioxidant capacity (TEAC); (iii) trolox equivalent antioxidant capacity (DPPH); (iv) ferric-ion reducing antioxidant parameter (FRAP); (v) cupric reducing antioxidant capacity (CUPRAC); (vi) oxygen radical absorbance capacity (ORAC). Ascorbic acid (AA), gallic acid (GA) and trolox (TR) were used as standards. All beers showed antioxidant power, but a wide range of ACs was observed. The effect of several factors upon these differences was studied. Statistical differences were found between ACs of beers of different colours. ORAC method provided always higher experimental ACs, of significant statistical differences to other assays.
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The state of the art of voltammetric and amperometric methods used in the study and determination of pesticides in crops, food, phytopharmaceutical products, and environmental samples is reviewed. The main structural groups of pesticides, i.e., triazines, organophosphates, organochlorides, nitrocompounds, carbamates, thiocarbamates, sulfonylureas, and bipyridinium compounds are considered with some degradation products. The advantages, drawbacks, and trends in the development of voltammetric and amperometric methods for study and determination of pesticides in these samples are discussed.
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Este articulo es una reflexin acerca del impacto de la epidemia 2009 en Argentina, con 26.000 afectados y seis muertes, y como las consecuencias pudieron haber sido mucho menores si hubiese existido dialogo y entendimiento entre epidemiologa y poltica sanitaria. La falta de preparacin, la descoordinacin en la respuesta y el impacto sobre la poblacin, confirman la brecha existente entre la evidencia cientfica y la toma de decisin poltica. La epidemiologia y la poltica sanitaria tienen distintas prioridades, distintos tiempos y distinta escala de valores. Las lecciones de la epidemia de 2009 deberan servir para acercar estos dos pilares de la salud publica de cara al beneficio de la comunidad, que al fin, es el objetivo comn.
