55 research outputs found

    Computer Simulation and Fire Drill in an Educational Building

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    Despite the evolution of computational models for evacuation simulations, there's still some doubt if they can generate accurate results. The objective is to analyze and compare the evacuation times of a fire drill and a computer simulation in an educational building. The method consisted of a fire drill with prior notice of a 4-floor building with classrooms in a public university. A computational model was developed for the same building and population using the evacuation simulation software Pathfinder. The results were that the evacuation times observed in the computer simulation were slightly lower than the times of the fire drill because people covered smaller distances due to the random distribution performed by the Pathfinder software and because in the drill some time was spent for the start of the movement toward the exit, which was estimated at around 30 seconds, while the software was configured for a pre-movement time equal to zero. The use of the computer simulation, therefore, proved to be an effective solution to replace the fire drill, since it allows for the identification of design failures and for the simulation of different scenarios in less time and without the need to mobilize people

    Semiclassical limit for Dirac particles interacting with a gravitational field

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    The behavior of spin-1/2 particle in a weak static gravitational field is considered. The Dirac Hamiltonian is diagonalized by the Foldy-Wouthuysen transformation providing also the simple form for the momentum and spin polarization operators. The operator equations of momentum and spin motion are derived for a first time. Their semiclassical limit is analyzed. The dipole spin-gravity coupling in the previously found (another) Hamiltonian does not lead to any observable effects. The general agreement between the quantum and classical analysis is established, contrary to several recent claims. The expression for gravitational Stern-Gerlach force is derived. The helicity evolution in the gravitational field and corresponding accelerated frame coincides, being the manifestation of the equivalence principle.Comment: 8 pages, no figures; version to appear in Physical Review

    Development of a Computational Tool for the Analysis of Hydro-Sanitary Designs

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    The high demand for hydro-sanitary designs to be analyzed by the public system, in addition to the long time it takes to complete such analyses, reveals that the employed verification methodology and bureaucratic procedures are obsolete. The main objective of this work was to develop a computational tool for releasing and analyzing hydro-sanitary systems, seeking to automate the process. The methodology was initiated with the creation of an electronic archive of the rules and laws pertinent to the subject, followed by the identification of the work routines for hydro-sanitary designs, the programming of the tool, the creation of an electronic repository for objects and, finally, the validation of the software through testing. As a result, the computational model will automatically retrieve project data in the BIM platform and assess information of designs developed in CAD. Based on this work, the conclusion can be drawn that the automation of the release and analysis processes of hydro-sanitary designs is possible and achievable

    Thomas rotation and Thomas precession

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    Exact and simple calculation of Thomas rotation and Thomas precessions along a circular world line is presented in an absolute (coordinate-free) formulation of special relativity. Besides the simplicity of calculations the absolute treatment of spacetime allows us to gain a deeper insight into the phenomena of Thomas rotation and Thomas precession.Comment: 20 pages, to appear in Int. J. Theo. Phy

    Investigação da ocorrência de eventos epigenéticos em Haemonchus contortus e sua relação com a resistência ao anti-helmíntico monepantel.

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    Os nematoides gastrintestinais, principalmente Haemonchus contortus, constituem o maior obstáculo à produção de ovinos e são controlados, em sua maioria, pelo uso de anti-helmínticos. Entretanto, os parasitas adquirem resistência a esses fármacos de maneira que, atualmente, o monepantel é o único anti-helmíntico efetivo na maioria dos rebanhos de pequenos ruminantes

    Spin, gravity, and inertia

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    The gravitational effects in the relativistic quantum mechanics are investigated. The exact Foldy-Wouthuysen transformation is constructed for the Dirac particle coupled to the static spacetime metric. As a direct application, we analyze the non-relativistic limit of the theory. The new term describing the specific spin (gravitational moment) interaction effect is recovered in the Hamiltonian. The comparison of the true gravitational coupling with the purely inertial case demonstrates that the spin relativistic effects do not violate the equivalence principle for the Dirac fermions.Comment: Revtex, 12 pages, no figures, accepted in Phys. Rev. Let

    Innovation Pathways to Adaption for Humanitarian and Development Goals: A Case Study of Aftershock Forecasting for Disaster Risk Management

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    The innovation process is central to effective adaption to climate change and development challenges, but models from business and management tend to dominate innovation theory, which sits outside the adaption-development paradigm. This paper presents an alternative conceptual framework to visualise innovations as pathways across the adaption-development landscape for humanitarian and development goals. This useful tool can reveal, map and coordinate innovation strategy. To demonstrate and validate this approach we analyse a case study of innovation in aftershock forecasting for humanitarian decision-making and show that the most effective strategy is for multiple innovation strands and hubs to move concurrently and cumulatively towards transformative humanitarian and development goals

    Avaliação do cumprimento da NR-18 em função do porte de obra residencial e proposta de lista de verificação da NR-18

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    O presente trabalho investiga as reais condições dos ambientes de trabalho da indústria da construção, tendo em vista os problemas relacionados à segurança do trabalho nos canteiros de obras. Formulou-se a hipótese de haver discrepância no grau de cumprimento da NR-18 em obras de diferentes portes (pequena, média e grande). Baseado em uma lista de verificação do grau de cumprimento dos requisitos da NR-18, foram avaliados 115 canteiros de obra na cidade de Chapecó - SC. Para cada item da lista de verificação foi atribuída uma nota e, após compilar as informações, estas foram avaliadas conforme os objetivos da pesquisa. Fez-se uma análise crítica para os cinco piores e os cinco melhores itens observados para as obras pequenas, médias e grandes. Analisando-se os resultados é possível afirmar que há uma diferença significativa de aplicação da NR-18 nos diferentes portes de obras, sendo que as obras de grande porte obtiveram uma média final (6,47) significativamente superior em relação às obras pequenas (1,97). Desta forma, foi corroborada a hipótese formulada, podendo se atribuir este resultado a diversos fatores, entre os quais a falta de habilidades gerenciais de segurança e saúde do trabalho nas pequenas empresas. Outra contribuição deste artigo foi a proposta de uma nova lista de verificação para avaliar o grau de cumprimento da NR-18 nos canteiros de obra

    Successful and unsuccessful approaches to imaging carcinoids: Comparison of a radiolabelled tryptophan hydroxylase inhibitor with a tracer of biogenic amine uptake and storage, and a somatostatin analogue

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    A mouse mastocytoma model was used to determine the biodistribution and tumour uptake of four radiopharmaceuticals developed to target the serotonin synthetic pathway in carcinoid tumours. Three of the compounds were competitive inhibitors of the rate-limiting enzyme of serotonin synthesis, tryptophan hydroxylase. Radiolabelled iodo- dl -phenylalanine (iodine-131 PIPA) was found to have the highest uptake and tumourto-liver ratio. Four patients with known carcinoid tumours were then injected with 0.5 mCi 131 I-PIPA and imaged at 1, 4, 24 and 48 h post-injection. The radiopharmaceutical, however, failed to localize in the known tumour sites. This result was in contrast to the authors' experience of 131 I- and 123 I-MIBG imaging of carcinoid tumours. Seven patients with known metastatic carcinoid tumours, two patients with symptoms of recurrence following tumour resection, one patient with completely resected disease, and two patients with a flushing syndrome of uncertain aetiology were studied with 131 I-MIBG. Three of the seven patients with known metastatic disease had positive 131 I-MIBG scans. Both patients with clinical evidence of recurrent disease had negative scans, as did the patient who was considered to have had complete resection of her primary tumour. The two patients with idiopathic flushing syndrome also had negative scans. Among seven patients imaged with 123 I-MIBG there were four true-negative scans and one falsenegative, the latter in a patient with biochemical and CT evidence of recurrence. In a seventh patient with distant metastases there was variable uptake in some of the lesions. Four patients were studied with indium-111 penetetreodide. Two patients with metastatic carcinoid disease had positive scans, although hepatic metastases were not seen in one. Another two with idiopathic flushing syndrome had normal studies. The literature suggests that up 50% of carcinoid tumour cases are detected with 131 I-MIBG, compared to a sensitivity of 87% reported with somatostatin receptor imaging using 111 In-pentetreotide. The experience with 123 I-MIBG is much less extensive. The mechanisms of carcinoid tumour localization for each of the three classes of radiotracers are discussed and contrasted to their varying sensitivities. The relative success of 131 I-MIBG and 111 In-pentetreotide relative to 131 I-PIPA may be related to the fact that 131 I-MIBG is actively taken up and stored by the enterochromaffin cells of the tumours and 111 In-pentetreotide binds to cell surface receptors, whereas 131 I-PIPA binds to tryptophan hydroxylase, which may be present in quantities too small to permit tumours to be imaged.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46840/1/259_2005_Article_BF01731835.pd
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