932 resultados para Regime semi-aberto
Resumo:
Several modern-day cooling applications require the incorporation of mini/micro-channel shear-driven flow condensers. There are several design challenges that need to be overcome in order to meet those requirements. The difficulty in developing effective design tools for shear-driven flow condensers is exacerbated due to the lack of a bridge between the physics-based modelling of condensing flows and the current, popular approach based on semi-empirical heat transfer correlations. One of the primary contributors of this disconnect is a lack of understanding caused by the fact that typical heat transfer correlations eliminate the dependence of the heat transfer coefficient on the method of cooling employed on the condenser surface when it may very well not be the case. This is in direct contrast to direct physics-based modeling approaches where the thermal boundary conditions have a direct and huge impact on the heat transfer coefficient values. Typical heat transfer correlations instead introduce vapor quality as one of the variables on which the value of the heat transfer coefficient depends. This study shows how, under certain conditions, a heat transfer correlation from direct physics-based modeling can be equivalent to typical engineering heat transfer correlations without making the same apriori assumptions. Another huge factor that raises doubts on the validity of the heat-transfer correlations is the opacity associated with the application of flow regime maps for internal condensing flows. It is well known that flow regimes influence heat transfer rates strongly. However, several heat transfer correlations ignore flow regimes entirely and present a single heat transfer correlation for all flow regimes. This is believed to be inaccurate since one would expect significant differences in the heat transfer correlations for different flow regimes. Several other studies present a heat transfer correlation for a particular flow regime - however, they ignore the method by which extents of the flow regime is established. This thesis provides a definitive answer (in the context of stratified/annular flows) to: (i) whether a heat transfer correlation can always be independent of the thermal boundary condition and represented as a function of vapor quality, and (ii) whether a heat transfer correlation can be independently obtained for a flow regime without knowing the flow regime boundary (even if the flow regime boundary is represented through a separate and independent correlation). To obtain the results required to arrive at an answer to these questions, this study uses two numerical simulation tools - the approximate but highly efficient Quasi-1D simulation tool and the exact but more expensive 2D Steady Simulation tool. Using these tools and the approximate values of flow regime transitions, a deeper understanding of the current state of knowledge in flow regime maps and heat transfer correlations in shear-driven internal condensing flows is obtained. The ideas presented here can be extended for other flow regimes of shear-driven flows as well. Analogous correlations can also be obtained for internal condensers in the gravity-driven and mixed-driven configuration.
Resumo:
Objectivo: Este estudo tem como objectivo principal a avaliação do impacto do acompanhamento farmacoterapêutico sobre o estado de saúde de doentes com tuberculose (casos novos) em tratamento em regime de ambulatório. Métodos: O estudo incluiu um período de screening com a duração de um mês, seguindo de um período de estudo com a duração de 12 meses. O estudo foi aberto, multicêntrico, randomizado com um grupo de estudo (n=35) e um grupo controlo (n=41). Como metodologia de intervenção foi aplicado uma metodologia baseada num estado de situação do doente e avaliação sistemática de resultados clínicos negativos da medicação. Os dados foram trabalhados em folha de cálculo Microsoft excel2003. Resultados: No grupo de estudo foram efectuadas 665 intervenções farmacêuticas, sobre 490 resultados clínicos negativos da medicação e 175 riscos de resultados clínicos negativos da medicação, de um total de 737 detectados. Houve intervenção sobre 90,23% dos resultados clínicos negativos da medicação, tendo-se resolvido 80,73%. O grupo de estudo teve uma melhor adesão à terapêutica (73,17% no grupo de estudo; 26,83% no grupo controlo) e melhores resultados microbiológicos (p=0,046)), não tendo sido encontradas diferenças estatísticas relativamente aos parâmetros clínicos e radiológicos. Conclusão: O acompanhamento farmacoterapêutico permite detectar, prevenir e resolver resultados clínicos negativos da medicação, resultando assim num impacto positivo sobre o estado de saúde dos doentes com tuberculose em regime de ambulatório. ABSTRACT: Objective: Main objective of this study is to evaluate the impact of medication follow up on the health status of patients with tuberculosis (incident cases) in treatment in an ambulatory regimen. Methods: The study included a screening period of one month and then a follow-up period of twelve months. lt was an open study, multicentric, randomized, with a study group (n=35) and a control group (n=41). Intervention consists in a process based on gathering patients’ therapeutic profile and its systematic evaluation of medication negative clinical outcomes. Data were processed in Microsoft Excel 2003 worksheet. Results: ln the study group 665 pharmaceutical interventions on 490 medication negative clinical outcomes due were recorded and 175 risk of negative clinical outcomes, having being detected a total of 737. Pharmacist interventions were done on 90.23% of negative clinical outcomes, resolving 80.73%. The study group had a better therapeutic compliance (73.17% in the study group; 26.83% in the control group) and better microbiological results (p=0.046). However, there were no differences concerning clinical and radiological parameters. Conclusion: Medication follow-up allows detecting, preventing and resolving medication negative clinical outcomes, having a positive impact on tuberculosis patients' health status treated in an ambulatory regimen.
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With favored offshore and downstream advection, the question of which physical mechanism may promote onshore transport of larvae in upwelling systems is of central interest. We have conducted a semi-realistic high resolution (0.25 km) numerical study of Lagrangian transports across the inner-shelf under upwelling-favorable wind forcing conditions, focusing on the shelf area of the Southwestern Portuguese coast, in the lee of Cape Sines. We add our findings to several years of biological observations of C. montagui, a planktonic species with higher recruitment during the upwelling peak timely with the daylight flood. Simulations cover a fifteen days period during the summer of 2006. We focused on Spring and Neap tide periods and observed upfront differences between simulations and the in situ observa- tions. However, the model is capable of representing the main dynamics of the region, namely the re- petitive character of the inner-shelf currents. We find that the cross-shore flow varies significantly in the daily cycle, and locally within a scale of a few kilometers in association with local topography and the presence of the cape. We consider the region immediately in the lee of the cape to be an upwelling shadow where the larvae became retained, and found that tidally tied migration proves beneficial for successful recruitment during the spring tides period. Our work suggested that the wind is not the only mechanism responsible for the daily variability of the cross-shore exchange. However, its sharp reversal at midday is critical for the advection of larvae towards the coast.
Comparison of Regime Switching, Probit and Logit Models in Dating and Forecasting US Business Cycles
Resumo:
Market-based environmental regulation is becoming increasingly common within international and national frameworks. Environmental offset and trading regimes are part of the market-based instrument revolution. This paper proposes that environmental market mechanisms could be used to introduce an ethic of land holder responsibility. In order for market based regimes to attract sufficient levels of stakeholder engagement, participants within such scheme require an incentive to participate and furthermore need to feel a sense of security about investing in such processes. A sense of security is often associated with property based interests. This paper explores the property related issues connected with environmental offset and trading scheme initiatives. Relevant property-related considerations include land tenure considerations, public versus private management of land choices, characteristics and powers associated with property interests, theories defining property and the recognition of legal proprietal interests. The Biodiversity Banking Scheme in New South Wales is then examined as a case study followed by a critique on the role of environmental markets.
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Based on Newmark-β method, a structural vibration response is predicted. Through finding the appropriate control force parameters within certain ranges to optimize the objective function, the predictive control of the structural vibration is achieved. At the same time, the numerical simulation analysis of a two-storey frame structure with magneto-rheological (MR) dampers under earthquake records is carried out, and the parameter influence on structural vibration reduction is discussed. The results demonstrate that the semi-active control based on Newmark-β predictive algorithm is better than the classical control strategy based on full-state feedback control and has remarkable advantages of structural vibration reduction and control robustness.
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The implementation of ‘good governance’ in Indonesia’s regional government sector became a central tenet in governance research following the introduction of the national code for governance in 2006. The code was originally drafted in 1999 as a response to the Asian financial crises and many cases of unearthed corruption, collusion, and nepotism. It was reviewed in 2001 and again in 2006 to incorporate relevant political, economical, and social developments. Even though the national code exists along with many regional government decrees on good governance, the extent of implementation of the tenets of good governance in Indonesia’s regional government is still questioned. Previous research on good governance implementation in Indonesian regional government (Mardiasmo, Barnes and Sakurai, 2008) identified differences in the nature and depth of implementation between various Indonesian regional governments. This paper analyses and extends this recent work and explores key factors that may impede the implementation and sustained application of governance practices across regional settings. The bureaucratic culture of Indonesian regional government is one that has been shaped for over approximately 30 years, in particular during that of the Soeharto regime. Previous research on this regime suggests a bureaucratic culture with a mix of positive and negative aspects. On one hand Soeharto’s regime resulted in strong development growth and strong economic fundamentals, resulting in Indonesia being recognised as one of the Asian economic tigers prior to the 1997 Asian financial crises. The financial crises however revealed a bureaucratic culture that was rife with corruption, collusion, and nepotism. Although subsequent Indonesian governments have been committed to eradicating entrenched practices it seems apparent that the culture is ingrained within the bureaucracy and eradication of it will take time. Informants from regional government agree with this observation, as they identify good governance as an innovative mechanism and to implement it will mean a deviation from the “old ways.” Thus there is a need for a “changed” mind set in order to implement sustained governance practices. Such an exercise has proven to be challenging so far, as there is “hidden” resistance from within the bureaucracy to change its ways. The inertia of such bureaucratic cultures forms a tension against the opportunity for the implementation of good governance. From this context an emergent finding is the existence of a ‘bureaucratic generation gap’ as an impeding variable to enhanced and more efficient implementation of governance systems. It was found that after the Asian financial crises the Indonesian government (both at national and regional level) drew upon a wider human resources pool to fill government positions – including entrants from academia, the private sector, international institutions, foreign nationals and new graduates. It suggested that this change in human capital within government is at the core of this ‘inter-generational divide.’ This divergence is exemplified, at one extreme, by [older] bureaucrats who have been in-position for long periods of time serving during the extended Soeharto regime. The “new” bureaucrats have only sat in their positions since the end of Asian financial crisis and did not serve during Soeharto’s regime. It is argued that the existence of this generation gap and associated aspects of organisational culture have significantly impeded modernising governance practices across regional Indonesia. This paper examines the experiences of government employees in five Indonesian regions: Solok, Padang, Gorontalo, Bali, and Jakarta. Each regional government is examined using a mixed methodology comprising of on-site observation, document analysis, and iterative semi-structured interviewing. Drawing from the experiences of five regional governments in implementing good governance this paper seeks to better understand the causal contexts of variable implementation governance practices and to suggest enhancements to the development of policies for sustainable inter-generational change in governance practice across regional government settings.
Resumo:
To date, most theories of business models have theorized value capture assuming that appropriability regimes were exogenous and that the firm would face a unique, ideal-typical appropriability regime. This has led theory contributions to focus on governance structures to minimize transaction costs, to downplay the interdepencies between value capture and value creation, and to ignore revenue generation strategies. We propose a reconceptualization of business models value capture mechanisms that rely on assumptions of endogeneity and multiplicity of appropriability regimes. This new approach to business model construction highlights the interdependencies and trade-offs between value creation and value capture offered by different types and combinations of appropriability regimes. The theory is illustrated by the analysis of three cases of open source software business models
Resumo:
Media organizations are simultaneously key elements of an effective democracy and, for the most part, commercial entities seeking success in the market. They play an essential role in the formation of public opinion and the influence on personal choices. Yet most of them are commercial enterprises seeking readers or viewers, advertising, favorable regulatory decisions for their media, and other assets. This creates some intrinsic difficulties and produces some sharp tensions within media ethics. In this article, we examine such tensions—in theory and practice. We then consider the feasibility of introducing an ethics regime to the media industry—a regime that would be effective in a deregulated environment in protecting public interest and social responsibility. In the article, we also outline a rationale and a methodology for the institutionalization of an acceptable and workable media ethics regime that aims to protect the integrity of the industry in a future of undoubtedly increasing commercial pressure.
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Section 35 of the Insurance Contracts Act 1984 requires insurers offering insurance policies in six prescribed areas "to clearly inform" prospective insureds of any departure their policies may constitute from the standard covers established by the Act and its accompanying Regulations. This prescribed insurance contracts regime was designed to remedy comprehension problems generated by the length and complexity of insurance documents and to alleviate misunderstanding over the terms and conditions of individual policies. This article examines the rationale underpinning s 35 and the prescribed insurance contracts regime and looks at the operation of the legislation with particular reference to home contents insurance in Australia. It is argued that the means whereby disclosure of derogation from standard cover may be effected largely negates the thrust of the prescribed insurance contract reform. Recommendations to address these operational deficiencies are made.
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An algorithm to improve the accuracy and stability of rigid-body contact force calculation is presented. The algorithm uses a combination of analytic solutions and numerical methods to solve a spring-damper differential equation typical of a contact model. The solution method employs the recently proposed patch method, which especially suits the spring-damper differential equations. The resulting semi-analytic solution reduces the stiffness of the differential equations, while performing faster than conventional alternatives.