The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The threshold switching characteristics of amorphous NbOx thin films is investigated with particular emphasis on temperature dependence of the switching characteristics. Threshold switching in this material is believed to result from a thermally-induced insulator-metal-transition (IMT) induced along a filamentary path by local Joule heating. Increasing the operating temperature is shown to lead to...
We utilize high power VCSEL arrays for several applications where high efficiency especially at high operating temperatures is essential. Our approach to design VCSEL devices optimized for the requirements of these applications is presented.
The contribution presents a flexible simulation model of thermoelectric devices, suitable for the design and control verification of related energy systems, e.g. waste heat recovery by a Thermoelectric Generator. The models are built according to the object-oriented scheme of the Modelica® language. Based on the essential physical effects of thermoelectric materials, the model components are applicable...
Electrical technology diagnostics is a branch of science examining the actual state of electrical machinery under the operation when using two basic accesses. The first and older one is an “off-line diagnostics”. It means a device or an appliance subjected to diagnostic process need to be for example disconnected from circuit, turned off or stopped. An on-line diagnostics — diagnosing a device during...
The n-type nonstoichiometric Pb0.55Te0.45 materials were prepared by melting and quenching combined with a subsequent high pressure high temperature (HPHT) treatment. After adequately annealed at 623 K in the argon atmosphere, the thermoelectric transport properties of the prepared samples have been systematically investigated. The results show that the pressure effectively adjusts the carrier concentration...
We have developed an on-line game, built around a simple simulator, as an innovative approach to mitigate the time and budget constraints that hinder the development of engineering expertise within a typical one-semester course. Students playing the game, as an alternative to calculation-based homework sets, develop a rich empirical understanding of the engineering principles of interest. A variety...
The use of temperature and time dependent material parameters is state-of-the-art in mechanical engineering. An advanced measurement method for the determination of moisture dependent parameters for micro and nano scale samples was developed. In combination with FE-analysis, this tool (involving time, temperature, and humidity) ensures a sure deployability. The present paper deals with the influence...
PIN-PMN-PT (Pb(Infrac12Nbfrac12)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3) single crystals with 26%-59% PIN were successfully grown by Bridgman technique. Elastic, dielectric and piezoelectric properties of ternary PIN-PMN-PT crystals were studied in comparison with PMN-PT (Pb(Mg1/3Nb2/3)O3 - PbTiO3) crystals. It was demonstrated that PIN-PMN-PT crystals possess as excellent piezoelectric properties as PMN-PT crystals,...
We measured, in the 873-1173 K temperature range, the temperature- and Cd vapor-pressure-dependences of the free electron density in single Cd1-xZnxTe≪In≫ (0 ≤ × ≤ 0.1) crystals with different In contents. Increasing the cooling rate of the crystals and/or decreasing the well-defined Cd vapor pressure reduced the free-electron density. We interpreted and modelled these phenomena and the crystal’s...
We measured, in the 873–1173 K temperature range, the temperature- and Cd vapor-pressure-dependences of the free electron density in single Cd1-xZnxTe≪In≫ (0 ≤ × ≤ 0.1) crystals with different In contents. Increasing the cooling rate of the crystals and/or decreasing the well-defined Cd vapor pressure reduced the free-electron density. We interpreted and modelled these phenomena and the crystal’s...
Investigations of the dielectric properties hysteresis formation in the artificial composite media based on the nanoparticles of the oxides and sulfides of the transition metals (copper, zinc, cobalt, cadmium) stabilized into the low density polyethylene (LDPE) matrix were carried out. Also investigation of the transition processes with the different metals contact were carried out. Mechanism of the...
Advances in micromachining technology can facilitate the integration of SAW (Surface Acoustic Wave) devices and CMOS circuitry on IC scale substrate for Monolithic fabrication. The optimal design and performance of these filters can be reached by using new Smart materials. The key component in the structure of the SAW device is the piezoelectric materials used which depends mainly on some important...
A physical yet analytical phase change memory (PCM) model simultaneously accounting for thermal and electrical conductivities is presented. Due to the physics based nature of the model, the essential temperature from heating and cooling of PCM during operation is instantaneously updated. More importantly, the model can be applied to non-conventional circuit design technique. We show that for the first...
In this study, investigation of the insulation performances of the silicone oil as an insulating medium is studied with aim of realization of environmental friendly electric power apparatus, which is considered to be flame retardant. This investigation is searching for the streaming electrification characteristics when silicone oil flows in consideration of cooling of electric power apparatus. In...
ldquoDevelopment for advanced thermoelectric conversion systemsrdquo supported by the new energy and industrial technology development organization (NEDO) has been successfully completed as one of the Japanese national energy conservation projects. Three types of the cascaded thermoelectric modules operating up to 850 K in high electrode temperature and two types of Bi-Te thermoelectric modules operating...
Thermoelectric properties of ternary silver thallium tellurides: Ag8T12Te5 and AgT13Te2 were studied above room temperature to slightly below the melting temperature. As for Ag8T12Te5, the effects of Te content on the thermoelectric properties were also studied by characterizing the samples of Ag8T12Tex (x = 5.0, 5.1, 5.2). Both compounds show positive Seebeck coefficient (S). Ag8T12Te5 indicates...
Angle resolved photoemission spectroscopy (ARPES) with a synchrotron radiation as an incident photon source was performed on the layered cobalt oxides Na0.8CoO2. The measured electronic structure was compared with that of the Na0.7CoO2 previously reported. The observed energy-momentum dispersion of the Na0.8CoO2 was essentially the same with that of the Na0.7CoO2 except for the small difference in...
Thermoelectric and galvanomagnetic properties have been studied in n-Bi2-xSbxTe3-y-zSeySz and p-Bi2-xSbxTe3-y-zSey multicomponent solid solutions with various atomic substitutions in both sublattices of Bi2Te3. Anisotropy of the constant energy surface and charge carrier scattering was determined within the framework of a many-valley-model of energy spectrum using isotropic and anisotropic scattering...
A theoretical model is proposed in this work for an evaluation of the specific heat and Debye temperature of thin-film semiconductors. In the model, the specific heat contributed by the confined acoustic phonons is calculated first. An effective Debye temperature is then defined by fitting the conventional Debye model to the calculated specific heat. It is found that the so-defined Debye temperatures...
The polycrystalline samples of BaSi2, SrSi2, and LaSi were prepared by spark plasma sintering (SPS). The electrical resistivity (rho) and Seebeck coefficient (S) were measured above room temperature. The S of BaSi2 was negative and the absolute values were rather high (-669 muVK-1 at 337 K). The S of SrSi2 was positive and the absolute values were lower (118 muVK-1 at 332 K) than those of BaSi2. For...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.