898 resultados para RATIONALE
Resumo:
A Lagoa de Araruama é reconhecida como a maior laguna hipersalina do mundo, cercada por dunas e vegetação de restinga que, emoldurando a sua decantada beleza natural, configura uma condição de cartão postal internacional. Isso associado à sua grande importância ecológica, faz com que ela se caracterize como um ambiente ímpar, dentro do contexto ambiental. Todavia a degradação de suas margens, ensejada pela sua ocupação desordenada, inclusive através da implantação de salinas, que vem ocorrendo há mais de um século, teve como consequência o desmatamento dessas áreas de preservação permanente, que se constituem na Faixa Marginal de Proteção (FMP). A fundamentação dessa proposta se pauta no fato de que a FMP vigente da lagoa, demarcada e aprovada através de Decreto n 42.694, de 11de novembro de 2010, não levou em conta esse aspecto de extrema relevância ambiental. Nessas condições, faz-se necessária a implementação de política voltada para ações com o objetivo de revitalizar o entorno da lagoa, de sorte a assegurar a preservação desse ecossistema localizado nas áreas limítrofes à orla da Lagoa de Araruama e garantir a sustentabilidade ambiental. O presente estudo se ateve ao levantamento das áreas em que se verificou a ocorrência de vegetação, com o intuito de ordenar a sua classificação, precipuamente com interesse em delimitar as áreas de restinga, que são consideradas Áreas de Preservação Permanente pela Resolução CONAMA 303/2002 e como parte integrante da FMP pelo Código Florestal, quando fixadoras de dunas e estabilizadoras de mangue. Em função dos resultados desse levantamento, propôs-se a inclusão, na Faixa Marginal de Proteção (FMP), das áreas em que ocorre a presença de vegetação de restinga, com respaldo no Código Florestal (Lei Federal n 4771/65) que, atualmente, disciplina o assunto, de sorte a preservar o corpo hídrico como um todo e garantir a sustentabilidade ambiental.
Resumo:
Esse trabalho propõe uma reflexão sobre a relação entre a organização da estrutura hospitalar baseada em sua divisão por enfermarias de especialidades e a perpetuação da lógica fragmentadora própria da Biomedicina, racionalidade médica hegemônica ocidental. O campo estudado foi o Hospital Universitário Pedro Ernesto. Através de entrevistas semiestruturadas com médicos clínicos, especialistas e profissionais responsáveis pela regulação de vagas desse hospital é discutida a existência de dois discursos diferentes: o discurso clínico e o discurso especialista. A partir da análise dessas entrevistas, foi apontada e debatida a profunda relação entre esses discursos, a estrutura hospitalar e a assistência médica oferecida aos pacientes. A análise realizada evidencia que embora os dois discursos estejam absolutamente inseridos no paradigma biomédico, a clínica médica se identifica e é identificada como responsável pelo paciente como um todo, enquanto as especialidades são reconhecidas como responsáveis apenas por uma determinada parte. Essa diferença apresentou influência tanto na forma de cuidar do paciente, como na função de cada serviço dentro do hospital. As enfermarias de clínica se caracterizaram por serem setores consensualmente capazes de conduzir satisfatoriamente a maioria dos pacientes.Se por um lado a abrangência da clínica é motivo de orgulho para os clínicos, por outro, a falta de autonomia decorrente dessa característica determina um sentimento de depreciação por parte desses profissionais. Esse trabalho foi realizado sob perspectiva hermenêutica filosófica proposta por Hans-Georg Gadamer e com o auxílio dos conceitos de paradigma proposto por Thomas Kuhn e estilo de pensamento elaborado por Ludwik Fleck.
Resumo:
Along the west coast of the United States, the potential impact of increasing pinniped populations on declining salmonid (Oncorhynchus spp.) stocks has become an issue of concern. Fisheries managers need species-specific estimates of consumption by pinnipeds to evaluate their impact on salmonid stocks. To estimate consumption, we developed a model that estimates diet composition by reconstructing prey biomass from fecal samples. We applied the model to data collected from harbor seals (Phoca vitulina) that are present year-round in the lower Columbia River where endangered stocks of salmonids pass as returning adults and as seaward-migrating smolts. Using the same data, we applied the split-sample frequency of occurrence model, which avoids reconstructing biomass by assuming that each fecal sample represents an equal volume of consumption and that within each sample each prey item represents an equal proportion of the volume. The two models for estimating diet composition yielded size-specific differences in consumption estimates that were as large as tenfold for the smallest and largest prey. Conclusions about the impact of harbor seal predation on adult salmonids, some of their largest prey species, remain uncertain without some appropriate rationale or further information (e.g. empirical captive studies) to discriminate between these models.
Resumo:
Where natural resources are a key component of the rural economy, the ability of the poor to realize their visions for the future depends significantly on institutional structures that govern resource access and management. This case study reports on an initiative on the shores of Lake Kariba in Zambia, where lakeshore residents face competition over fishing, tourism, and commercial aquaculture. Multistakeholder dialogue produced agreements with investors and increased accountability of state agencies and traditional leaders, enabling communities to have greater influence over their futures through improvements in aquatic resource governance. The report documents the rationale for the approach followed and steps in the capacity-building process, discusses obstacles encountered, and identifies lessons for policymakers and practitioners seeking to implement a similar approach.
Resumo:
Human ingenuity has made it possible to advent the chromosome manipulation techniques to produce individuals with differing genomic status in a number of fish using various causal agents such as physical shocks (temperature or hydrostatic pressure), chemical (endomitotics) and anesthetic treatments either to suppress the second meiotic division shortly after fertilization of eggs or to prevent the first mitotic division shortly prior to mitotic cleavage formation. This results in the induction of polyploidy (triploidy and tetraploidy), gynogenesis (both meiotic and mitotic leading to clonal lines) and androgenesis in fish population. The rationale for the induction of such ploidy in fish has been its potential for generating sterile individuals, rapidly inbred lines and masculinized fish, which could be of benefit to fish farming and aquaculture. In this paper, these are critically reviewed and the implication of recently developed chromosome manipulation techniques to various fin fishes is discussed.
Resumo:
A new method for multivariable control was proposed in McFarlane and Glover (1988 CDC). This method involved shaping the open-loop singular values with pre and/or post compensators and then designing a controller to robustly stabilize a normalized coprime factorization of this weighted plant. The method has many attractive features including guaranteed loop shape and robust stability and performance. This talk will outline the rationale of this method and illustrate its use on a number of applications.
Resumo:
Over recent years academia and industry have engaged with the challenge of model testing deepwater structures at conventional scales. One approach to the limited depth problem has been to truncate the lines. This concept will be introduced, highlighting the need to better understand line dynamic processes. The type of line truncation developed here models the upper sections of each line in detail, capturing wave action and all coupling effects with the vessel, terminating to an approximate analytical model that aims to simulate the remainder of the line. A rationale for this is that in deep water transverse elastic waves of a line are likely to decay before they are reflected at the seabed because of nonlinear hydrodynamic drag forces. The first part of this paper is centered on verification of this rationale. A simplified model of a mooring line that describes the transverse dynamics in wave frequency is used, adopting the equation of motion of an inextensible taut string. The line is submerged in still water, one end fixed at the bottom the other assumed to follow the vessel response, which can be harmonic or random. A dimensional analysis, supported by exact benchmark numerical solutions, has shown that it is possible to produce a universal curve for the decay of transverse vibrations along the line, which is suitable for any kind of line with any top motion. This has a significant engineering benefit, allowing for a rapid assessment of line dynamics - it can be useful in deciding whether a truncated line model is appropriate, and if so, at which point truncation might be applied. This is followed by developing a truncation mechanism, formulating an end approximation that can reproduce the correct impedance, had the line been continuous to full depth. It has been found that below a certain length criterion, which is also universal, the transverse vibrational characteristics for each line are inertia driven. As such the truncated model can assume a linear damper whose coefficient depends on the line properties and frequency of vibration. Copyright © 2011 by the International Society of Offshore and Polar Engineers (ISOPE).
Resumo:
Rationale: Discriminating right from left is an everyday cognitive ability. Repeated exposure to certain drugs, such as heroin, can produce poor performance on many cognitive tasks. However, it is yet unclear whether drug abuse impairs the ability of right-left discrimination. Objectives: The aim of the present study is to examine whether the spatial ability measured by the right-left discrimination task can be affected by heroin abuse and whether such drug effect, if it exists, is gender related. Methods: A paper-and-pen test was used. The test consists of line drawings of a person with no arm, one arm, or both arms crossing the vertical body axis of the figure. The line drawings are viewed from the back, from the front, or randomly alternating between the back and front drawings. The subjects task is to mark which is the right or left hand in the figure as fast as possible. Results: A main finding in this study was that the ability to discriminate between left and right in visual space was impaired in heroin-dependent patients. Especially, heroin-dependent females performed poorer than control females in all conditions but heroin-dependent males only performed poorly in part of conditions. Conclusions: Recent heroin abuse impairs the ability of right-left discrimination and such impairment is gender related: heroin-dependent females demonstrated greater performance deficits than males.
Resumo:
EAFFRO and UNPP/LVFRP bottom trawl exploratory data have been used to describe the depth distributional pattern. relative abundance and magnitude of the demersai fishes in Lake Victoria. The results have been compared with the commercial catch estimates, and various interpretations of the trends in the annual catches and experimental biomass estimates in relation to possible future developments of the fishery have been suggested. Though it is highly desirable to develop the fishery such as by supplementary trawling, certain social and biological consequences and considerations needs to proceed in graded steps guided by several research disciplines. The past trends of the fisheries of Lake Victoria are briefly considered. Recent exploratory bottom trawl data, by EAFFRO and UNDP/LVFRP, have been used to define demersal fish stocks of Lake Victoria in terms of their magnitude, relative abundance and distribution pattern by depth. Enstence of disparity between the relative abundance of the various species in their commercial catches and in their present biomass estimates is pointed out and the various aspects associated with the necessary modification of the fishing practices are discussed. Further and continuing research of the bio-socio-economic vectors of the fishery will be necessary in order to generate the rationale of an efficient fishing regime for a rational management strategy and realistic utilization of the fishery resource.
Resumo:
This paper will provide a rationale for developing control systems based on the availability of automated identification (Auto ID) information provision. Much of the Auto-ID research has to date focussed on developing the essential infrastructure for dynamically extracting, networking and storing product data. These developments will help to revolutionise the accuracy, quality and timeliness of data acquired by Business Information Systems and should lead to major cost savings and performance improvements as a result. This paper introduces an additional phase of Auto ID research and development in which the nature of control system decisions is reconsidered in the light of the availability of ubiquitous, unique, item-level information. The paper will: (i) Indicate why the availability of ubiquitous, unique, item-level data can enable enhanced and fundamentally different control approaches and highlight potential benefits from control systems incorporating this Auto ID data (ii) Demonstrate what is required to develop control systems based around the availability of Auto ID data. (iii) Outline the research challenges in determining how such systems will be developed.
Resumo:
Model tests for global design verification of deepwater floating structures cannot be made at reasonable scales. An overview of recent research efforts to tackle this challenge is given first, introducing the concept of line truncation techniques. In such a method the upper sections of each line are modelled in detail, capturing the wave action zone and all coupling effects with the vessel. These terminate to an approximate analytical model, that aims to simulate the remainder of the line. The rationale for this is that in deep water the transverse elastic waves of a line are likely to decay before they are reflected at the seabed. The focus of this paper is the verification of this rationale and the ongoing work, which is considering ways to produce a truncation model. Transverse dynamics of a mooring line are modelled using the equations of motion of an inextensible taut string, submerged in still water, one end fixed at the bottom the other assumed to follow the vessel response, which can be harmonic or random. Nonlinear hydrodynamic damping is included; bending and VIV effects are neglected. A dimensional analysis, supported by exact benchmark numerical solutions, has shown that it is possible to produce a universal curve for the decay of transverse vibrations along the line, which is suitable for any kind of line with any top motion. This has a significant engineering benefit, allowing for a rapid assessment of line dynamics - it is very useful in deciding whether a truncated line model is appropriate, and if so, at which point truncation might be applied. Initial efforts in developing a truncated model show that a linearized numerical solution in the frequency domain matches very closely the exact benchmark. Copyright © 2011 by ASME.
Resumo:
This paper provides an overview of the rationale behind the significant interest in polymer-based on-board optical links together with a brief review of recently reported work addressing certain challenges in this field. Polymer-based optical links have garnered considerable research attention due to their important functional attributes and compelling cost-benefit advantages in on-board optoelectronic systems as they can be cost-effectively integrated on conventional printed circuit boards. To date, significant work on the polymer materials, their fabrication process and their integration on standard board substrates have enabled the demonstration of numerous high-speed on-board optical links. However, to be deployed in real-world systems, these optoelectronic printed circuit boards (OE PCBs) must also be cost-effective. Here, recent advances in the integration process focusing on simple direct end-fire coupling schemes and the use of low-cost FR4 PCB substrates are presented. Performance of two proof-of-principle 10 Gb/s systems based on this integration method are summarised while work in realising more complex yet compact planar optical components is outlined. © 2011 IEEE.
Resumo:
Design rationale is an effective way of capturing knowledge, since it records the issues addressed, the options considered, and the arguments used when specific decisions are made during the design process. Design rationale is generally captured by identifying elements and their dependencies, i.e. in a structured way. Current retrieval methods focus mainly on either the classification of rationale or on keyword-based searches of records. Keyword-based retrieval is reasonably effective as the information in design rationale records is mainly described using text. However, most of the current keyword-based retrieval methods discard the implicit structures of these records, resulting either in poor precision of retrieval or in isolated pieces of information that are difficult to understand. This ongoing research aims to go beyond keyword-based retrieval by developing methods and tools to facilitate the provision of useful design knowledge in new design projects. Our first step is to understand the structured information derived from the relationship between lumps of text held in different nodes in the design rationale captured via a software tool currently used in industry, and study how this information can be utilised to improve retrieval performance. Specifically, methods for utilising various structured information are developed and implemented on a prototype keyword-based retrieval system developed in our earlier work. The implementation and evaluation of these methods shows that the structured information can be utilised in a number of ways, such as filtering the results and providing more complete information. This allows the retrieval system to present results that are easy to understand, and which closely match designers' queries. Like design rationale, other methods for representing design knowledge also in essence involve structured information and thus the methods proposed can be generalised to be adapted and applied for the retrieval of other kinds of design knowledge. Copyright © 2002-2012 The Design Society. All rights reserved.
Resumo:
Low-temperature (∼600 °C), scalable chemical vapor deposition of high-quality, uniform monolayer graphene is demonstrated with a mapped Raman 2D/G ratio of >3.2, D/G ratio ≤0.08, and carrier mobilities of ≥3000 cm(2) V(-1) s(-1) on SiO(2) support. A kinetic growth model for graphene CVD based on flux balances is established, which is well supported by a systematic study of Ni-based polycrystalline catalysts. A finite carbon solubility of the catalyst is thereby a key advantage, as it allows the catalyst bulk to act as a mediating carbon sink while optimized graphene growth occurs by only locally saturating the catalyst surface with carbon. This also enables a route to the controlled formation of Bernal stacked bi- and few-layered graphene. The model is relevant to all catalyst materials and can readily serve as a general process rationale for optimized graphene CVD.
Resumo:
A systematic study of the parameter space of graphene chemical vapor deposition (CVD) on polycrystalline Cu foils is presented, aiming at a more fundamental process rationale in particular regarding the choice of carbon precursor and mitigation of Cu sublimation. CH 4 as precursor requires H 2 dilution and temperatures ≥1000 °C to keep the Cu surface reduced and yield a high-quality, complete monolayer graphene coverage. The H 2 atmosphere etches as-grown graphene; hence, maintaining a balanced CH 4/H 2 ratio is critical. Such balance is more easily achieved at low-pressure conditions, at which however Cu sublimation reaches deleterious levels. In contrast, C 6H 6 as precursor requires no reactive diluent and consistently gives similar graphene quality at 100-150 °C lower temperatures. The lower process temperature and more robust processing conditions allow the problem of Cu sublimation to be effectively addressed. Graphene formation is not inherently self-limited to a monolayer for any of the precursors. Rather, the higher the supplied carbon chemical potential, the higher the likelihood of film inhomogeneity and primary and secondary multilayer graphene nucleation. For the latter, domain boundaries of the inherently polycrystalline CVD graphene offer pathways for a continued carbon supply to the catalyst. Graphene formation is significantly affected by the Cu crystallography; i.e., the evolution of microstructure and texture of the catalyst template form an integral part of the CVD process. © 2012 American Chemical Society.