Search results for "electric [charge]"
showing 10 items of 729 documents
Manufacturing Te/PEDOT Films for Thermoelectric Applications
2017
In this work, flexible Te films have been synthesized by electrochemical deposition using PEDOT [poly(3,4-ethylenedioxythiophene)] nanofilms as working electrodes. The Te electrodeposition time was varied to find the best thermoelectric properties of the Te/PEDOT double layers. To show the high quality of the Te films grown on PEDOT, the samples were analyzed by Raman spectroscopy, showing the three Raman active modes of Te: E1, A1, and E2. The X-ray diffraction spectra also confirmed the presence of crystalline Te on top of the PEDOT films. The morphology of the Te/PEDOT films was studied using scanning electron microscopy, showing a homogeneous distribution of Te along the film. Also an a…
1/f noise in streaming electrification
2005
The paper presents the measurement results of the noise generated by static electricity. The tests were performed in the spinning-disk system. Insulation liquid (transformer oil) was used for electrostatic charge generation. The element measured was the current flowing to the disk surface. A stochastic term is present in the current. Existance of this term is due to the complex chemical constitution of the oil. A relaxation of the polar molecules has inertial character. The spreading of a large amount of the relaxation phenomena can lead to forming a compounded spectrum close in shape to 1/f noise. Power spectral density of the polarization was defined for periodic step function. The calcul…
Local Metamaterial-Based Waveguides in Gaps Between Parallel Metal Plates
2009
This letter presents a new metamaterial-based waveguide technology referred to as ridge gap waveguides. The main advantages of the ridge gap waveguides compared to hollow waveguides are that they are planar and much cheaper to manufacture, in particular at high frequencies such as for millimeter and sub- millimeter waves. The latter is due to the fact that there are no mechanical joints across which electric currents must float. The gap waveguides have lower losses than microstrip lines, and they are completely shielded by metal so no additional packaging is needed, in contrast to the severe packaging problems associated with microstrip circuits. The gap waveguides are realized in a narrow …
Electrical connections and driving electronics for piezo-actuated x-ray thin glass optics
2016
Use of thin glass modular optics is a technology currently under study to build light, low cost, large area X-ray telescopes for high energy astrophysics space missions. The angular resolution of such telescopes is limited by local deviations from the ideal shape of the mirrors. One possible strategy to improve it consists in actively correcting the mirror profile by gluing thin ceramic piezo-electric actuators on the back of the glasses. A large number of actuators, however, requires several electrical connections to drive them with the different needed voltages. We have developed a process for depositing conductive paths directly on the back of non-planar thin foil mirrors by means of a p…
Local Bonding Influence on the Band Edge and Band Gap Formation in Quaternary Chalcopyrites
2017
Quaternary chalcopyrites have shown to exhibit tunable band gaps with changing anion composition. Inspired by these observations, the underlying structural and electronic considerations are investigated using a combination of experimentally obtained structural data, molecular orbital considerations, and density functional theory. Within the solid solution Cu2ZnGeS4-x Se x , the anion bond alteration parameter changes, showing larger bond lengths for metal-selenium than for metal-sulfur bonds. The changing bonding interaction directly influences the valence and conduction band edges, which result from antibonding Cu-anion and Ge-anion interactions, respectively. The knowledge of the underlyi…
Dielectric and acoustic properties of modified barium titanate ceramics
2019
This work was supported in part by the Ministry of Education and Science of the Russian Federation.
Depletion-induced percolation in networks of nanorods.
2006
Above a certain density threshold, suspensions of rod-like colloidal particles form system-spanning networks. Using Monte Carlo simulations, we investigate how the depletion forces caused by spherical particles affect these networks in isotropic suspensions of rods. Although the depletion forces are strongly anisotropic and favor alignment of the rods, the percolation threshold of the rods decreases significantly. The relative size of the effect increases with the aspect ratio of the rods. The structural changes induced in the suspension by the depletant are characterized in detail and the system is compared to an ideal fluid of freely interpenetrable rods.
Friction based Solid State Welding Techniques for Transportation Industry Applications
2014
Abstract Solid bonding based processes represent an effective solution in terms of both joints mechanical performances and sustainability. In the last years, both the academic and the industrial researchers focused their work on two solid-state processes: Friction Stir Welding (FSW) and Linear Friction Welding (LFW). The former, patented in 1991 by TWI, is used to weld sheet metal in different joint morphologies, i.e. butt, lap T and 3D joints. The latter has been known for several years, but a growing interest is observed in the last years due to the enhancement of the welding machines performances. LFW, used to join bulk components, is particularly suited for aeronautical and aerospace ap…
Enhanced thermoelectric performance of chalcopyrite nanocomposite via co-milling of synthetic and natural minerals
2020
Chalcopyrite CuFeS2 was shown to be a promising thermoelectric material. Considering thermoelectric efficiency, its relatively high and temperature weakly dependent power factor, economic affordability and ecological benignity is counterbalanced by a high lattice thermal conductivity. Thus it is highly desirable to lower the thermal conductivity of chalcopyrite thermoelectric material without deterioration of other thermoelectric characteristics. In our study, we demonstrate that mechanosynthesis followed by appropriate sintering enables to prepare such nanostructured ceramics with a favourable thermoelectric response. Our study shows that mechanosynthesis is a low-cost technological route …
Hybrid Tribo-Piezo-Electric Nanogenerator with Unprecedented Performance Based on Ferroelectric Composite Contacting Layers
2019
This research was supported by the European Regional Development Fund within the project ‘‘Hybrid energy harvesting systems’’ 1.1.1.1./16/A/013.