Search results for "Electricity"
showing 10 items of 1225 documents
Physical properties of (1−x)Ba0.95Pb0.05TiO3+xCo2O3 (x=0, 0.1, 0.3, 0.5, 1.0, 2.0wt%) ceramics
2015
The paper reports studies of the (1−x)Ba0.95Pb0.05TiO3 – xCo2O3 (x≤0.02) ceramics. Results of X-ray powder diffraction, dielectric, magnetic and IR measurements, as well as ab initio simulations are presented. The Co-doping induces small decrease of the (c/a) tetragonality of the perovskite lattice and leads to the gradual shift of the ferroelectric transition temperature from 398 K for x=0 down to 357 K for x=0.02. The conductivity activation energies are in the range 0.8–0.9 eV in agreement with the calculations. The high-temperature conductivity can be ascribed by the migration of oxygen vacancies introduced to compensate the charge deficiency due to Co3+ valence at the B-site of the per…
Transition to distributed energy generation in Finland: Prospects and barriers
2015
Abstract Small-scale distributed energy generation is expected to play an important role in helping Finland increase its energy self-sufficiency. However, the overall strategy to date for promoting distributed energy remains unclear. It is not yet well understood which factors promote the growth of the distributed energy sector and what barriers need to be removed. In this article we present the results of a questionnaire directed at a panel of 26 experts from the distributed energy value chain and 15 semi-structured interviews with industry and non-industry representatives. We investigated, from a sociotechnical transition perspective, the possibilities and challenges of the transition to …
Modern Electrochemical Aspects for the Synthesis of Value‐Added Organic Products
2017
The use of electricity instead of stoichiometric amounts of oxidizers or reducing agents in synthesis is very appealing for economic and ecological reasons, and represents a major driving force for research efforts in this area. To use electron transfer at the electrode for a successful transformation in organic synthesis, the intermediate radical (cation/anion) has to be stabilized. Its combination with other approaches in organic chemistry or concepts of contemporary synthesis allows the establishment of powerful synthetic methods. The aim in the 21st Century will be to use as little fossil carbon as possible and, for this reason, the use of renewable sources is becoming increasingly impo…
An equivalent single-layer model for magnetoelectroelastic multilayered plate dynamics
2012
Abstract An equivalent single-layer model for the dynamic analysis of magnetoelectroelastic laminated plates is presented. The electric and magnetic fields are assumed to be quasi-static and the first-order shear deformation theory is used. The formulation of the model provides for a preliminary fulfillment of the electro-magnetic governing equations, which allows to determine the electric and magnetic potential as functions of the mechanical variables. Then, by using this result, the equations of motion are written leading to the problem governing equations. They involve the same terms of the elastic dynamic problem weighted by effective stiffness coefficients, which take the magneto-elect…
Creep Modeling with Time-Dependent Damping Parameters in Piezoelectric Actuators
2019
This paper develops a creep model based on the Kelvin-Voigt model with time varying damping parameters. In the piezoelectric actuators, the creep phenomenon is an important issue in precise positioning applications as well as the hysteresis property. It is well-known that the creep effect can be represented by a series connection of a number of Kelvin-Voigt elements as a viscoelastic model. In the motion for the continuous stepwise positioning, however, the creep shape is different for each response. Since the phenomenon can be captured as temporal creep relaxation, time-dependent damping parameters are introduced to improve the reproducibility of the creep for the various motion. On the ot…
Effect of high-intensity pulsed electric fields processing and conventional heat treatment on orange-carrot juice carotenoids.
2005
Liquid chromatography (LC) was the method of choice for quantification of carotenoids (including geometrical isomers) to evaluate the effects of high-intensity pulsed electric field (HIPEF), a nonthermal preservation method, with different parameters (electric field intensities and treatment times), on an orange−carrot juice mixture (80:20, v/v). In parallel, a conventional heat treatment (98 °C, 21 s) was applied to the juice. HIPEF processing generally caused a significant increase in the concentrations of the carotenoids identified as treatment time increased. HIPEF treatment at 25 and 30 kV/cm provided a vitamin A concentration higher than that found in the pasteurized juice. Keywords: …
Energy and environmental assessment of residual bio-wastes management strategies
2021
Abstract This paper assesses the potential energy and environmental impacts of an anaerobic digester coupled with a combined heat and power plant powered with bio-wastes from the agri-food sector. The analysis is carried out through the Life Cycle Assessment methodology following a “cradle-to-grave” approach and is based mostly on primary data. The anaerobic digester - combined heat and power plant is analysed considering a twofold perspective: one more energy – oriented where the main function of the system is to generate renewable electricity and a waste – oriented one in which the main function is treating bio-wastes. In addition, the environmental indirect effects related to potential c…
Sustainable Energy Supply Based on Sunflower Seed Husk for Oil mills
2019
The use of biomass, including sunflower husk, for in-situ energy generation has undergone a development in Ukraine last decades. Within this work, four combined heat and power technologies based on oil utilization, husk combustion, gasification, and methanization have been investigated. Their electricity and heat potential has been determined. Criteria for techno-economical assessment of CHP technologies have been suggested. Husk biogas and gasification technologies are not mature. CHP plants based on husk combustion are competitive. Steam turbine generators with a nominal electric capacity higher 1.5 MW may be profitable too.
A Hybrid Power Supply with Variable Speed Drive for Automatically Move Irrigation Equipment: Margin of Feasibility
2021
Center pivot irrigation systems are widely used in agriculture. Their water pumping systems are primary energy consumers. The use of photovoltaic power plants and variable speed drives of electric motors can reduce energy costs. The purpose of this study is to determine the feasibility of integrating variable speed drives and photovoltaic modules into water pumping systems. A novel architecture of a pumping system was suggested. Its features are no battery backup and the sale of electricity into the grid.
Design, modeling, and simulation of a photovoltaic water pumping system
2018
Electric pumps cannot be fed in those areas where they are not connected to the electric public distribution grid. In those areas, it is useful to feed electric pumps by means of the electricity generated from renewable energy sources plants. Among these, the Solar Water Pumping Systems feed electric pump thanks to the electricity generated by a photovoltaic plant. In this paper, a whole SWPS is fully designed, modelled, and simulated in Matlab environment. The proposed implementation is an useful tool for SWPS testing.