3,127 research outputs found
Powering a Biosensor Using Wearable Thermoelectric Technology
Wearable medical devices such as insulin pumps, glucose monitors, hearing aids, and electrocardiograms provide necessary medical aid and monitoring to millions of users worldwide. These battery powered devices require battery replacement and frequent charging that reduces the freedom and peace of mind of users. Additionally, the significant portion of the world without access to electricity is unable to use these medical devices as they have no means to power them constantly. Wearable thermoelectric power generation aims to charge these medical device batteries without a need for grid power.
Our team has developing a wristband prototype that uses body heat, ambient air, and heat sinks to create a temperature difference across thermoelectric modules thus generating ultra-low voltage electrical power. A boost converter is implemented to boost this voltage to the level required by medical device batteries. Our goal was to use this generated power to charge medical device batteries off-the-grid, increasing medical device user freedom and allowing medical device access to those without electricity. We successfully constructed a wearable prototype that generates the voltage required by an electrocardiogram battery; however, further thermoelectric module and heat dissipation optimization is necessary to generate sufficient current to charge the battery
Padrão de desenvolvimento brasileiro: o agronegócio e sua dinâmica no oeste baiano
XX Encontro Nacional de Economia Política: desenvolvimento Latino-Americano, Integração e Inserção Internacional - UNILA, Foz do Iguaçu, 26 a 29 de maio de 2015A expansão do agronegócio nas últimas três décadas da economia
brasileira, suscita debates nos mais variados campos da sociedade.
Seja no âmbito acadêmico, econômico, político ou ambiental, as
questões que envolvem o tema “agronegócio” estão cada vez mais
presentes. Este trabalho tem como objetivo caracterizar e discutir a
relação existente entre a dinâmica do agronegócio da soja e o atual
padrão de desenvolvimento brasileiro denominado, neste trabalho,
Modelo Liberal Periférico. Nesse sentido, este artigo lança mão de
um aporte teórico para a compreensão do processo dialético de
reprodução do capital numa formação social específi ca, o conceito
de padrão de desenvolvimento e seu uso na experiência histórico-
concreta da economia brasileira. A metodologia do trabalho tem
como base os dados empíricos da economia brasileira e o arcabouço
teórico da economia políticaBanco Nacional de Desenvolvimento Econômico e Social (BNDES); Usina Hidrelétrica de Itaipu (ITAIPU); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) e Universidade Federal da Integração Latino-Americana (UNILA
Perspectiva da fruticultura na Amazônia: uma análise macro.
O impacto mais visível da questão ambiental na Amazônia desencadeado pós-assassinato de Chico Mendes, em 1988, foi dar visibilidade a frutas amazônicas como açaí, cupuaçu, bacuri, pupunha, taperebá, tucumã, uxi, bacaba, que antes tinha consumo local e restrito a época da safra de 3 a 4 meses. Com o crescimento do mercado foram aperfeiçoadas as técnicas de beneficiamento e armazenamento, fazendo com que o consumo seja efetuado durante o ano, além do crescimento do mercado local e a entrada no mercado nacional e internacional. Outras frutas cultivadas no país, também, tiveram grande crescimento como abacaxi, laranja, banana, maracujá, acerola, entre as principai
Dimensões da prática pedagógica do professor de Química
A pesquisa teve como objetivo investigar as abordagens metodológicas adotadas por um grupo de professores de Química do Ensino Médio. Elegendo a água como tema gerador, elaboramos um questionário que foi respondido por onze professores de Química vinculados a sete escolas públicas estaduais, por meio de entrevistas semi-estruturadas. O roteiro de questões contemplou formas de abordagens, recursos didáticos e atividades desenvolvidas no processo ensino-aprendizagem. As respostas dos entrevistados foram transcritas e categorizadas de acordo com os pressupostos teóricos e metodológicos da Análise de Conteúdo. Os resultados evidenciaram uma prática tradicional de ensino exercida pela maioria dos entrevistados, a qual parece ser pautada na transmissão dos conhecimentos científicos
Automatic grid refinement criterion for lattice Boltzmann method
In all kinds of engineering problems, and in particular in methods for
computational fluid dynamics based on regular grids, local grid refinement is
of crucial importance. To save on computational expense, many applications
require to resolve a wide range of scales present in a numerical simulation by
locally adding more mesh points. In general, the need for a higher (or a lower)
resolution is not known a priori, and it is therefore difficult to locate areas
for which local grid refinement is required. In this paper, we propose a novel
algorithm for the lattice Boltzmann method, based on physical concepts, to
automatically construct a pattern of local refinement. We apply the idea to the
two-dimensional lid-driven cavity and show that the automatically refined grid
can lead to results of equal quality with less grid points, thus sparing
computational resources and time. The proposed automatic grid refinement
strategy has been implemented in the parallel open-source library Palabos
Switching to efficient technologies in traditional biomass intensive countries: The resultant change in emissions
This paper aims to quantify the benefits of switching from a system dependent on traditional biomass to systems running on more efficient fuels and technologies. It is estimated that even when open fires burning fuelwood are replaced by improved cooking stoves (ICSs) and liquefied petroleum gas (LPG) stoves, and biomass is processed in dedicated biomass power plants, a net reduction in CO2 emissions is still obtained. The ICS/LPG stove/biomass combustion power plant configuration could provide an average net reduction of 84 kg-C-e/tDM. Meanwhile, a net reduction of 105 kg-C-e/tDM could be obtained when implementing a ICS/LPG stove/biomass gasification power plant scheme. Main factors influencing the net reduction of CO2 emissions are technology efficiency and the fraction of non-renewable fuel wood use. The switch from traditional biomass to modern biomass in traditional biomass intensive countries must not only be done to reduce CO2 emissions but also to avoid indoor pollution and energy poverty. Health improvements should be more important than energy savings. Results also indicate that the use of modern biomass systems not only could provide a reduction of local environmental pollution, but also could boost the local economy by the creation of biomass infrastructures
The role of Nav1.9 channel in the development of neuropathic orofacial pain associated with trigeminal neuralgia
BACKGROUND: Trigeminal neuralgia is accompanied by severe mechanical, thermal and chemical hypersensitivity of the orofacial area innervated by neurons of trigeminal ganglion (TG). We examined the role of the voltage-gated sodium channel subtype Nav1.9 in the development of trigeminal neuralgia. RESULTS: We found that Nav1.9 is required for the development of both thermal and mechanical hypersensitivity induced by constriction of the infraorbital nerve (CION). The CION model does not induce change on Nav1.9 mRNA expression in the ipsilateral TG neurons when evaluated 9 days after surgery. CONCLUSIONS: These results demonstrate that Nav1.9 channels play a critical role in the development of orofacial neuropathic pain. New routes for the treatment of orofacial neuropathic pain focussing on regulation of the voltage-gated Nav1.9 sodium channel activity should be investigated
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