934 resultados para engineering and maintenance enterprises
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MCM-41 periodic mesoporous silicates with a high degree of structural ordering are synthesized and used as model adsorbents to study the isotherm prediction of nitrogen adsorption. The nitrogen adsorption isotherm at 77 K for a macroporous silica is measured and used in high-resolution alpha(s)-plot comparative analysis to determine the external surface area, total surface area and primary mesopore volume of the MCM-41 materials. Adsorption equilibrium data of nitrogen on the different pore size MCM-41 samples (pore diameters from 2.40 to 4.92 nm) are also obtained. Based on the Broekhoff and de Boer' thermodynamic analysis, the nitrogen adsorption isotherms for the different pore size MCM-41 samples are interpreted using a novel strategy, in which the parameters of an empirical expression, used to represent the potential of interaction between the adsorbate and adsorbent, are obtained by fitting only the multilayer region prior to capillary condensation for C-16 MCM-41. Subsequently the entire isotherm, including the phase transition, is predicted for all the different pore size MCM-41 samples without any fitting. The results show that the prediction of multilayer adsorption and total adsorbed amount are in good agreement with the experimental isotherms. The predictions of the relative pressure corresponding to capillary equilibrium (coexistence) transition agree remarkably with experimental data on the adsorption branch even for hysteretic isotherms, confirming that this is the branch appropriate for pore size distribution analysis. The impact of pore radius on the adsorption film thickness and capillary coexistence pressure is also investigated, and found to agree with the experimental data. (C) 2003 Elsevier Inc. All rights reserved.
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Ouabain increases vascular resistance and may induce hypertension by inhibiting the Na+ pump. The effects of 0.18 and 18 µg/kg, and 1.8 mg/kg ouabain pretreatment on the phenylephrine (PHE; 0.1, 0.25 and 0.5 µg, in bolus)-evoked pressor responses were investigated using anesthetized normotensive (control and uninephrectomized) and hypertensive (1K1C and DOCA-salt treated) rats. Treatment with 18 µg/kg ouabain increased systolic and diastolic blood pressure in all groups studied. However, the magnitude of this increase was larger for the hypertensive 1K1C and DOCA-salt rats than for normotensive animals, while the pressor effect of 0.18 µg/kg ouabain was greater only in DOCA-salt rats. A very large dose (1.8 mg/kg) produced toxic effects on the normotensive control but not on uninephrectomized or 1K1C rats. Rat tail vascular beds were perfused to analyze the effects of 10 nM ouabain on the pressor response to PHE. In all animals, 10 nM ouabain increased the PHE pressor response, but this increase was larger in hypertensive DOCA-salt rats than in normotensive and 1K1C rats. Results suggested that a) increases in diastolic blood pressure induced by 18 µg/kg ouabain were larger in hypertensive than normotensive rats; b) in DOCA-salt rats, smaller ouabain doses had a stronger effect than in other groups; c) hypertensive and uninephrectomized rats were less sensitive to toxic doses of ouabain, and d) after treatment with 10 nM ouabain isolated tail vascular beds from DOCA-salt rats were more sensitive to the pressor effect of PHE than those from normotensive and 1K1C hypertensive rats. These data suggest that very small doses of ouabain, which might produce nanomolar plasma concentrations, enhance pressor reactivity in DOCA-salt hypertensive rats, supporting the idea that endogenous ouabain may contribute to the increase and maintenance of vascular tone in hypertension.
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Protein-based polymers are present in a wide variety of organisms fulfilling structural and mechanical roles. Advances in protein engineering and recombinant DNA technology allow the design and production of recombinant protein-based polymers (rPBPs) with an absolute control of its composition. Although the application of recombinant proteins as biomaterials is still an emerging technology, the possibilities are limitless and far superior to natural or synthetic materials, as the complexity of the structural design can be fully customized. In this work, we report the electrospinning of two new genetically engineered silk-elastin-like proteins (SELPs) consisting of alternate silk- and elastin-like blocks. Electrospinning was performed with formic acid and aqueous solutions at different concentrations without addition of further agents. The size and morphology of the electrospun structures was characterized by scanning electron microscopy showing to be dependent of concentration and solvent used. Treatment with air saturated with methanol was employed to stabilize the structure and promote water insolubility through a time-dependent conversion of random coils into β-sheets (FTIR). The resultant methanol-treated electrospun mats were characterized for swelling degree (570-720%), water vapour transmission rate (1083 g/m2/day) and mechanical properties (modulus of elasticity of ~126 MPa). Furthermore, the methanol-treated SELP fiber mats showed no cytotoxicity and were able to support adhesion and proliferation of normal human skin fibroblasts. Adhesion was characterized by a filopodia-mediated mechanism. These results demonstrate that SELP fiber mats can provide promising solutions for the development of novel biomaterials suitable for tissue engineering applications.
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The progressive aging of the population requires new kinds of social and medical intervention and the availability of different services provided to the elder population. New applications have been developed and some services are now provided at home, allowing the older people to stay home instead of having to stay in hospitals. But an adequate response to the needs of the users will imply a high percentage of use of personal data and information, including the building up and maintenance of user profiles, feeding the systems with the data and information needed for a proactive intervention in scheduling of events in which the user may be involved. Fundamental Rights may be at stake, so a legal analysis must also be considered.
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In this paper we aim to identify and analyze a set of variables that can potentially influence the adoption and knowledge of the Balanced Scorecard (BSC) in Portugal. Hypotheses were tested using data obtained from a questionnaire sent to 591 publicly-owned organizations (local governments, municipal corporations and hospitals) and 549 privately-owned organizations (large companies and small and medium enterprises) in Portugal. The results allow us to conclude that although the majority of respondents claimed to know the BSC, its use in Portugal is still limited and very recent, particularly in the public sector organizations. However, it should be noted that its use has increased in Portugal in recent years. The study also reveals that in spite of the noticeable differences between public and private sector, the BSC is used in the public sector after a few adjustments to the traditional model. Using as theoretical framework the contingency and institutional theories, we found that decentralization, vertical differentiation and the degree of higher education are associated with the implementation of the BSC.
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In this article we aim to identify and analyze a set of variables that can potentially influence the adoption of the Balanced Scorecard (BSC)in Portugal. Hypotheses were tested using data obtained from a questionnaire sent to 591 publicly-owned organizations (local governments, municipal corporations and hospitals) and 549 privately-owned organizations (large companies and small and medium enterprises) in Portugal, with an overall response rate of 31.3%. The results allow us to conclude that although the majority of respondents claimed to know the BSC, its use in Portugal is still limited and very recent, particularly in the public sector organizations. However, it should be noted that its use has increased in Portugal in recent years. Using as theoretical framework the contingency and institutional theories, we found that decentralization, vertical differentiation and the degree of higher education are associated with the implementation of the BSC.
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The purpose of this study is to characterise the environmental management systems (EMS) certification process (International Organization for Standardization (ISO) 14001) in Portuguese small and medium enterprises (SMEs) following quality management system (QMS) certification (ISO 9001). The study is based on a sample from Portuguese SMEs which characterise the local reality in terms of companies certified in accordance with ISO 14001 after ISO 9001 certification. Some Portuguese SMEs have the EMS implemented but not certified, mainly given the lack of investment support and because it is considered merely a form of marketing. As such, they do not feel motivated to certificate an EMS in the company since they consider that it is a form of advertising and not a way to protect the environment. Nonetheless, it is already evident form other Portuguese SMEs that gained EMS certification that gains supersede marketing benefits and allow for evermore enduring benefits such as prevention of environmental risks, environment protection, improved company image, compliance with legislation and efficient use of natural resources. This paper also presented the main difficulties in achieving an EMS certification, including high certification costs, human resources, motivation issues and difficulties in changing the company’s culture.
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RESUMO: Hoje em dia o software tornou-se num elemento útil na vida das pessoas e das empresas. Existe cada vez mais a necessidade de utilização de aplicações de qualidade, com o objectivo das empresas se diferenciarem no mercado. As empresas produtoras de software procuram aumentar a qualidade nos seus processos de desenvolvimento, com o objectivo de garantir a qualidade do produto final. A dimensão e complexidade do software aumentam a probabilidade do aparecimento de não-conformidades nestes produtos, resultando daí o interesse pela actividade de testes de software ao longo de todo o seu processo de concepção, desenvolvimento e manutenção. Muitos projectos de desenvolvimento de software são entregues com atraso por se verificar que na data prevista para a sua conclusão não têm um desempenho satisfatório ou por não serem confiáveis, ou ainda por serem difíceis de manter. Um bom planeamento das actividades de produção de software significa usualmente um aumento da eficiência de todo o processo produtivo, pois poderá diminuir a quantidade de defeitos e os custos que decorrem da sua correcção, aumentando a confiança na utilização do software e a facilidade da sua operação e manutenção. Assim se reconhece a importância da adopção de boas práticas no desenvolvimento do software. Para isso deve-se utilizar uma abordagem sistemática e organizada com o intuito de produzir software de qualidade. Esta tese descreve os principais modelos de desenvolvimento de software, a importância da engenharia dos requisitos, os processos de testes e principais validações da qualidade de software e como algumas empresas utilizam estes princípios no seu dia-a-dia, com o intuito de produzir um produto final mais fiável. Descreve ainda alguns exemplos como complemento ao contexto da tese. ABSTRACT: Nowadays the software has become a useful element in people's lives and it is increasingly a need for the use of quality applications from companies in order to differentiate in the market. The producers of software increase quality in their development processes, in order to ensuring final product quality. The complexity and size of software, increases the probability of the emergence of non-conformities in these products, this reason increases of interest in the business of testing software throughout the process design, development and maintenance. Many software development projects are postpone because in the date for delivered it’s has not performed satisfactorily, not to be trusted, or because it’s harder to maintain. A good planning of software production activities, usually means an increase in the efficiency of all production process, because it can decrease the number of defects and the costs of it’s correction, increasing the reliability of software in use, and make it easy to operate and maintenance. In this manner, it’s recognized the importance of adopting best practices in software development. To produce quality software, a systematic and organized approach must be used. This thesis describes the main models of software development, the importance of requirements engineering, testing processes and key validation of software quality and how some companies use these principles daily, in order to produce a final product more reliable. It also describes some examples in addition to the context of this thesis.
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Versão editor: http://www.isegi.unl.pt/docentes/acorreia/documentos/European_Challenge_KM_Innovation_2004.pdf
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An increasing amount of research is being developed in the area where technology and humans meet. The success or failure of technologies and the question whether technology helps humans to fulfill their goals or whether it hinders them is in most cases not a technical one. User Perception and Influencing Factors of Technology in Everyday Life addresses issues of human and technology interaction. The research in this work is interdisciplinary, ranging from more technical subjects such as computer science, engineering, and information systems, to non-technical descriptions of technology and human interaction from the point of view of sociology or philosophy. This book is perfect for academics, researchers, and professionals alike as it presents a set of theories that allow us to understand the interaction of technology and humans and to put it to practical use.
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The way humans interact with technology is undergoing a tremendous change. It is hard to imagine the lives we live today without the benefits of technology that we take for granted. Applying research in computer science, engineering, and information systems to non-technical descriptions of technology, such as human interaction, has shaped and continues to shape our lives. Human Interaction with Technology for Working, Communicating, and Learning: Advancements provides a framework for conceptual, theoretical, and applied research in regards to the relationship between technology and humans. This book is unique in the sense that it does not only cover technology, but also science, research, and the relationship between these fields and individuals' experience. This book is a must have for anyone interested in this research area, as it provides a voice for all users and a look into our future.
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Globalisation has eliminated frontiers and in the case of Europe helped the crossing of borders and changed forever the concept of social (and I would also say individual) geography: the rest of the world is out there; we can pretend not to see it, but we cannot avoid it. Moreover, Europe is undergoing a serious crisis, also economic, and new markets and business partners are welcome. In this context, cultural bonds like a common language can open new investment paths and give rise to successful stories. In this paper we intend to present an example of how low linguistic distance can lead to good business, even if a) in the internationalization process of the companies’ language is often forgotten as a management element and b) consumers of language products (like User Guides) are also not stimulating investment in language by the companies. Through the results of 2 studies carried out in 2010 and 2011 we will show how a pluricentric language like Portuguese is managed in multinational companies (MC) and Small and medium Enterprises (SMEs). The second study is based on an online survey questioning the effectiveness, efficiency and general quality of User Guides and the reaction of consumers to language. Results show that although playing a role in the internationalization process of companies in the same linguistic space, language is opportunistically used. On the other hand, Portuguese and Brazilian consumers show a very functional perception of the Portuguese language...
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Several antineoplasic drugs have been demonstrated to be carcinogenic or to have mutagenic and teratogenic effects. The greatest protection is achieved with the implementation of administrative and engineering controls and safety procedures. Objective: to evaluate the improvements on pharmacy technicians' work practices, after the implementation of operational procedures related to individual protection, biologic safety cabinet disinfection and cytotoxic drug preparation. Method: case-study in a hospital pharmacy undergoing a certification process. Six pharmacy technicians were observed during their daily activities. Characterization of the work practices was made using a checklist based on ISOPP and PIC guidelines. The variables studied concerning cleaning/disinfection procedures, personal protective equipment and procedures for preparing cytotoxic drugs. The same work practices were evaluated after four months of operational procedures implementation. Concordance between work practices and guidelines was considered to be a quality indicator (guidelines concordance practices number/total number of practices x 100). Results: improvements were observed after operational procedures implementation. An improvement of 6,25% in personal protective equipment practice was achieved by changing second pair of gloves every thirty minutes. The major progress, 10%, was obtained in disinfection procedure, where 80% of tasks are now realized according to guidelines.By now, we hot an improvement of only 1% at drug preparation procedure by placing one cytotoxic drug at a time inside the biological safety cabinet. Then, 85% of practices are according to guidelines. Conclusion: before operational procedures implementation 80,3% of practices were according to the guidelines, while now is 84,4%. This indicates that is necessary to review the procedures frequently in the benefit to reduce the risks associated with handling cytotoxic drugs and maintenance of drug specifications.
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Currently, power systems (PS) already accommodate a substantial penetration of distributed generation (DG) and operate in competitive environments. In the future, as the result of the liberalisation and political regulations, PS will have to deal with large-scale integration of DG and other distributed energy resources (DER), such as storage and provide market agents to ensure a flexible and secure operation. This cannot be done with the traditional PS operational tools used today like the quite restricted information systems Supervisory Control and Data Acquisition (SCADA) [1]. The trend to use the local generation in the active operation of the power system requires new solutions for data management system. The relevant standards have been developed separately in the last few years so there is a need to unify them in order to receive a common and interoperable solution. For the distribution operation the CIM models described in the IEC 61968/70 are especially relevant. In Europe dispersed and renewable energy resources (D&RER) are mostly operated without remote control mechanisms and feed the maximal amount of available power into the grid. To improve the network operation performance the idea of virtual power plants (VPP) will become a reality. In the future power generation of D&RER will be scheduled with a high accuracy. In order to realize VPP decentralized energy management, communication facilities are needed that have standardized interfaces and protocols. IEC 61850 is suitable to serve as a general standard for all communication tasks in power systems [2]. The paper deals with international activities and experiences in the implementation of a new data management and communication concept in the distribution system. The difficulties in the coordination of the inconsistent developed in parallel communication and data management standards - are first addressed in the paper. The upcoming unification work taking into account the growing role of D&RER in the PS is shown. It is possible to overcome the lag in current practical experiences using new tools for creating and maintenance the CIM data and simulation of the IEC 61850 protocol – the prototype of which is presented in the paper –. The origin and the accuracy of the data requirements depend on the data use (e.g. operation or planning) so some remarks concerning the definition of the digital interface incorporated in the merging unit idea from the power utility point of view are presented in the paper too. To summarize some required future work has been identified.
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The International Agency for Research on Cancer classified formaldehyde as carcinogenic to humans because there is “sufficient epidemiological evidence that it causes nasopharyngeal cancer in humans”. Genes involved in DNA repair and maintenance of genome integrity are critically involved in protecting against mutations that lead to cancer and/or inherited genetic disease. Association studies have recently provided evidence for a link between DNA repair polymorphisms and micronucleus (MN) induction. We used the cytokinesis-block micronucleus (CBMN assay) in peripheral lymphocytes and MN test in buccal cells to investigate the effects of XRCC3 Thr241Met, ADH5 Val309Ile, and Asp353Glu polymorphisms on the frequency of genotoxicity biomarkers in individuals occupationally exposed to formaldehyde (n = 54) and unexposed workers (n = 82). XRCC3 participates in DNA double-strand break/recombination repair, while ADH5 is an important component of cellular metabolism for the elimination of formaldehyde. Exposed workers had significantly higher frequencies (P < 0.01) than controls for all genotoxicity biomarkers evaluated in this study. Moreover, there were significant associations between XRCC3 genotypes and nuclear buds, namely XRCC3 Met/Met (OR = 3.975, CI 1.053–14.998, P = 0.042) and XRCC3 Thr/Met (OR = 5.632, CI 1.673–18.961, P = 0.005) in comparison with XRCC3 Thr/Thr. ADH5 polymorphisms did not show significant effects. This study highlights the importance of integrating genotoxicity biomarkers and genetic polymorphisms in human biomonitoring studies.