Search results for "electric [charge]"
showing 10 items of 729 documents
Concepts for medium-high to high temperature thermoelectric heat-to-electricity conversion: a review of selected materials and basic considerations o…
2015
Within the last decade, novel materials concepts and nanotechnology have resulted in a great increase of the conversion efficiency of thermoelectric materials. Despite this, a mass market for thermoelectric heat-to-electricity conversion is yet to be opened up. One reason for this is that the transfer of the lab records into fabrication techniques which enable thermoelectric generator modules is very challenging. By closing the gap between record lab values and modules, broad industrial applications may become feasible. In this review, we compare three classes of materials, all designed for medium-high to high temperature applications in the field of waste heat recovery: skutterudites, half…
A Hybrid Energy Storage Sizing for a Vertical Take-off and Landing Electric Aircraft
2021
The energy storage sizing procedure for an all-electric aircraft, characterised by vertical take-off and landing (VTOL), is presented in the paper. In order to define the energy consumption, the propulsion system model has been developed and simulated, referring to a specific configuration of VOLT obtained by the transformation of a very light twin-propeller aircraft named Tecnam P2012 T. Specifically, a flight mission-oriented to air city taxing has been considered. The simulation results highlight the presence of significant peak power during take-off and landing. At the aim of optimising the weight and the volume of the energy storage systems (ESSs), considered a critical issue in all-el…
Transverse distribution of beam current oscillations of a 14 GHz electron cyclotron resonance ion source
2014
The temporal stability of oxygen ion beams has been studied with the 14 GHz A-ECR at JYFL (University of Jyvaskyla, Department of Physics). A sector Faraday cup was employed to measure the distribution of the beam current oscillations across the beam profile. The spatial and temporal characteristics of two different oscillation “modes” often observed with the JYFL 14 GHz ECRIS are discussed. It was observed that the low frequency oscillations below 200 Hz are distributed almost uniformly. In the high frequency oscillation “mode,” with frequencies >300 Hz at the core of the beam, carrying most of the current, oscillates with smaller amplitude than the peripheral parts of the beam. The result…
Study of the pyroelectricity in LiIns2 crystal
2002
Abstract Pyroelectric current measurements performed on a LiInS2 monodomain single crystal show a linear variation of the current between 120 and 260 K. Near room temperature, a space charge relaxation screens pyroelectricity. The pyroelectric coefficient follows a linear thermal dependence leading to an extrapolated value of 6×10−10 C K−1 cm−2 at 300 K. As for other oxide-type pyroelectric compounds, this value is shown to be proportional to the electro-optic coefficient r333 of LiInS2.
Physical Fundamentals of Biomaterials Surface Electrical Functionalization
2020
This article is focusing on electrical functionalization of biomaterial&rsquo
EoP250. Recent advances in transparent ferroelectric ceramics research and applications
1992
Abstract The studies of field-induced lattice rearrangement and field-induced phase transition (PT), laser beam effects in transparent ferroelectric ceramics (TFC), dopant and radiation effects in PLZT, Kerr effect demonstration and application of an intracavity matrix-addressed spatial-time modulator are discussed.
Assessing the feasibility of cogeneration retrofit and district heating/cooling networks in small Italian islands
2017
Sustainability of energy supply strategies in small islands has been emerging as a severe issue, due to the large margins for improvement and rationalization of the most frequently adopted solutions. In most of the European islands, large amounts of heat are wasted by the operation of engine-based power plants; conversely, heat is produced by boilers (supplied by liquid fuels) or by electric equipment for a number of different uses, like domestic hot water production or space heating in winter. In this paper a techno-economic analysis is proposed to assess the feasibility of CHP-retrofit of the existing power plants and the possible utilization of the recovered heat to supply, via a distric…
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…
Formation and Rupture of Schottky Nanocontacts on ZnO Nanocolumns
2007
In this paper, the electrical transport and mechanical properties of Pt/ZnO Schottky nanocontacts have been studied simultaneously during the formation and rupture of the nanocontacts. By combining multidimensional conducting scanning force spectroscopy with appropriated data processing, the physical relevant parameters (the ideality factor, the Schottky barrier height, and the rupture voltage) are obtained. It has been found that the transport curves strongly depend on the loading force. For loading forces higher than a threshold value, the transport characteristics are similar to those of large-area Schottky contact, while below this threshold deviations from strictly thermionic emission …
Electric field driven domain wall transfer in hybrid structures
2012
Domain wall (DW) motion devices attracts much interest with their prospective logic and memory applications[1][2]. Present on-chip DW manipulations by a magnetic field of electric currents or electron spin torque raise the problem of high Ohmic energy losses. We show that such a difficulty can be avoided by applying an exchange field H eff to the magnetic layer from the proximate graphene (Gr), instead of using an actual magnetic field. H eff is shown to be dependent on carrier density gradient in Gr, which is easily manipulated with a gate voltage. A novel memory device implementing this concept is designed and modeled, demonstrating switching power well below femto-Joule while maintaining…