871 research outputs found

    Certain Building Materials with Respect to Their Thermal Properties as Well as to Their Impact to Environment

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    Thermal properties of certain building materials were studied with respect to environmental aspects. The building materials with significant insulation properties were laboratory tested using the special equipment based on Peltier module. During the experimental work, the samples of the following materials were tested: Expanded polystyrene (EPS), Autoclaved aerated concrete (AAC): Ytong, Calcium Silicate Board: Super-Isol and Foam glass (Cellular Glass Insulation): PERINSUL. The temperature was measured directly in connection of material with the Peltier module as well as in the distances of 5mm, 27.5mm, 50mm and 95mm from the Peltier module. The temperature taken at the surface of Peltier module reached -22°C, a typical temperature in the cold winter season. The results of the laboratory experimental work were modelled using the graphic representation. Modelling the thermal distribution will help to determine the ideal material thickness in the design of the building insulation. 

    Evaluation or perfusion and thermal parameters of skiin tissue using cold provocation and thermographic measurements

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    Measurement of the perfusion coefficient and thermal parameters of skin tissue using dynamic thermography is presented in this paper. A novel approach based on cold provocation and thermal modelling of skin tissue is presented. The measurement was performed on a person’s forearm using a special cooling device equipped with the Peltier module. The proposed method first cools the skin, and then measures the changes of its temperature matching the measurement results with a heat transfer model to estimate the skin perfusion and other thermal parameters. In order to assess correctness of the proposed approach, the uncertainty analysis was performed

    The elusive half-pole in the transfer function of Peltier thermoelectric devices

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    it is shown that the transfer function of thermoelectric devices includes a half pole, which could be useful in precisione control loop

    Modelling of a thin film thermoelectric micro-Peltier module

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    A micro Peltier cooler/heater module has been modelled. The module consists of n-type bismuth telluride and p-type antimony telluride thermoelectric materials. The commercial software package CFD-ACE+ has been used to implement and analyse the model. A two-dimensional coupled electrical and thermal simulation was performed. This software includes the possibility to incorporate the Peltier effect. The temperature, electric field intensity and wall heat flux distributions were simulated for different applied potentials. The variation in temperature difference with respect to the Seebeck coefficient of the material was calculated and analysed

    Dirac-Surface-State-Dominated Spin to Charge Current Conversion in the Topological Insulator (Bi0.22Sb0.78)2Te3(Bi_{0.22}Sb_{0.78})_2Te_3 Films at Room Temperature

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    We report the spin to charge current conversation in an intrinsic topological insulator (TI) (Bi0.22Sb0.78)2Te3(Bi_{0.22}Sb_{0.78})_2Te_3 film at room temperature. The spin currents are generated in a thin layer of permalloy (Py) by two different processes, spin pumping (SPE) and spin Seebeck effects (SSE). In the first we use microwave-driven ferromagnetic resonance of the Py film to generate a SPE spin current that is injected into the TI (Bi0.22Sb0.78)2Te3(Bi_{0.22}Sb_{0.78})_2Te_3 layer in direct contact with Py. In the second we use the SSE in the longitudinal configuration in Py without contamination by the Nernst effect made possible with a thin NiO layer between the Py and (Bi0.22Sb0.78)2Te3(Bi_{0.22}Sb_{0.78})_2Te_3 layers. The spin-to-charge current conversion is attributed to the inverse Edelstein effect (IEE) made possible by the spin-momentum locking in the electron Fermi contours due to the Rashba field. The measurements by the two techniques yield very similar values for the IEE parameter, which are larger than the reported values in the previous studies on topological insulators.Comment: 18 pages and 7 figure

    Characterization of a Peltier module working as a thermoelectric generator

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    Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Any: 2015, Tutor: Cèsar FerraterWe studied the suitability of current thermoelectric devices as electrical power generators, measuring the I-V curves of a Peltier cooler under field-like conditions. We designed an experimental system that allowed the Peltier module to work under a constant thermal input ux or a constant temperature difference. From these I-V curves we have calculated the thermoelectric figure of merit and the conversion e ciency of the device, comparing it with maximum theoretical values

    Simulácie a modelovanie absorpčnej chladiacej jednotky pomocou Peltierovho modulu

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    Article refers to function of absorption cooling unit simulated by means of Peltier module. Although, this system works on entirely different physical principle, it is necessary to use it as equiv-alent of absorption cooling what is proved in more detail in article.Článok poukazuje na činnosť absorpčnej chladiacej jednotky simulovanej pomocou Peltierovho modulu. Hoci tento systém pracuje na úplne odlišnom fyzikálnom princípe, je možné ho použiť ako ekvivalent absorpčného chladenia, čo je bližšie dokázané v článku
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