Search results for " electric field"
showing 10 items of 35 documents
Modeling X-ray emission from stellar coronae
2008
By extrapolating from observationally derived surface magnetograms of low-mass stars we construct models of their coronal magnetic fields and compare the 3D field geometry with axial multipoles. AB Dor, which has a radiative core, has a very complex field, whereas V374 Peg, which is completely convective, has a simple dipolar field. We calculate global X-ray emission measures assuming that the plasma trapped along the coronal loops is in hydrostatic equilibrium and compare the differences between assuming isothermal coronae, or by considering a loop temperature profiles. Our preliminary results suggest that the non-isothermal model works well for the complex field of AB Dor, but not for the…
Electrochemical remediation of kaolin-soil contaminated by phenol: effect of several operative parameters
Electrochemical remediation technology is considered an appealing strategy for the remediation of fine- grained soils, characterized by a low hydraulic conductivity and large specific surface area, contaminated with inorganic, organic, and mixed pollutants. In both Electrokinetic (EK) and Electrochemical Geo-Oxidation (ECGO) technologies, an electric field is imposed on the contaminated soil to remove the pollutants by the combined mechanisms of electroosmosis, electromigration, and/or electrophoresis. Moreover, ECGO uses low voltage and both direct and alternating amperage (DC/AC) applied in a proprietary series to induce reduction-oxidation reactions on soil surfaces at the micro-scale. A…
Dielectric response of BaTiO electronic states under AC fields via microsecond time-resolved X-ray absorption spectroscopy
2021
This research was performed under the approval of the Photon Factory Program Advisory Committee (PF-PAC; Contract Numbers 2015G580, 2017G587, and 2019G614) and was financially supported by JSPS KAKENHI Grant Numbers 18H01153 , 19H02426 , and 18K19126 . The experiment for measuring spectra in Fig. 6 (b) was performed on beamline BM26A (proposal MA 2731) at the European Synchrotron Radiation Facility (ESRF), Grenoble, France. We are grateful to Local Contact at the ESRF for providing assistance in using beamline BM26A. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPRE…
Application of Pulsed Electric Field Treatment for Food Waste Recovery Operations
2016
International audience; Food industry is generating annually huge quantities of by-products and waste, which are generally considered as problem, as their disposal is associated with environmental and health related issues. During the last decade, numerous research groups and industries have been interested in valorizing these by-products by extracting valuable compounds and incorporating them generally in food and/or cosmetic products, which enhances the profitability of the process. Conventional extraction methods (i.e., maceration, thermal extraction) are exten- sively used for such purposes and showed high yields in many cases. However, the need to replace toxic organic solvents, shorte…
Electric Field Effect on the Thermal Decomposition and Co-combustion of Straw with Solid Fuel Pellets
2019
The aim of this study was to provide more effective use of straw for energy production by co-firing wheat straw pellets with solid fuels (wood, peat pellets) under additional electric control of the combustion characteristics at thermo-chemical conversion of fuel mixtures. Effects of the DC electric field on the main combustion characteristics were studied experimentally using a fixed-bed experimental setup with a heat output up to 4 kW. An axisymmetric electric field was applied to the flame base between the positively charged electrode and the grounded wall of the combustion chamber. The experimental study includes local measurements of the composition of the gasification gas, flame tempe…
Effect of Pulsed Electric Field Pretreatment on Drying Kinetics, Color, and Texture of Parsnip and Carrot.
2018
The aim of the study was to evaluate the effect of pulsed electric field (PEF) pretreatment on drying kinetics and on color and textural changes in sliced parsnip and carrot. Cell disintegration index measured in parsnips after PEF pretreatment significantly differed from the ones measured for carrots and, consequently, the reduction of the time needed to dry both samples to a final moisture content up to 5% (wet basis). The drying time of the PEF pretreated parsnip was reduced by up to 28% at 70 °C and by up to 21% at 60 °C in carrot, in comparison to untreated samples. The PEF pretreatment influenced the effective diffusivity of water into the samples going from 50 °C to 70 °C: in carrots…
Mild processing applied to the inactivation of the main foodborne bacterial pathogens: A review
2017
International audience; Salmonella, Listeria monocytogenes, Escherichia coli O157:H7 and Campylobacter are the major bacterial pathogens associated with foodborne diseases and their inactivation is fundamental to ensure microbiologically safe products. Although efficient in generating safe foods with proper shelf-lives, pasteurization and commercial sterilization may result in numerous nutritional and sensory changes in foods. To address these disadvantages, mild processing methods (i.e., processing technologies for food preservation that apply mild temperature; <40 °C) aiming to destroy microbial food contaminants have been developed.Scope and approachThis review emphasizes the main applic…
Pulsed Electric Field: Fundamentals and Effects on the Structural and Techno-Functional Properties of Dairy and Plant Proteins
2022
Dairy and plant-based proteins are widely utilized in various food applications. Several techniques have been employed to improve the techno-functional properties of these proteins. Among them, pulsed electric field (PEF) technology has recently attracted considerable attention as a green technology to enhance the functional properties of food proteins. In this review, we briefly explain the fundamentals of PEF devices, their components, and pulse generation and discuss the impacts of PEF treatment on the structure of dairy and plant proteins. In addition, we cover the PEF-induced changes in the techno-functional properties of proteins (including solubility, gelling, emulsifying, and foamin…
Comparing the effects of thermal and non-thermal technologies on pomegranate juice quality: A review.
2019
The consumption of pomegranate juice (PJ) has increased substantially since scientific literature reported its therapeutic benefits that are attributable to antioxidant, antimicrobial, anti-carcinogenic, and anti- inflammatory properties. The growing consumer demands for fresh and high-quality food products have led to the interest in non- thermal technologies for preservation of fruit juices. Although thermal pasteurization is the most widely used preservation technology, it has adverse effects on the nutritional and sensory quality of juices. Conversely, non- thermal technologies are suitable alternatives for preservation and without negative effects on the quality. However, there is limi…
Study of the role of particle-particle dipole interaction in dielectrophoretic devices for biomarkers identification
2015
A three dimensional Coupled Monte Carlo-Poisson method has been used to evaluate the impact of particle-particle dipole interactions in the equilibrium distribution of a system of uncharged polarizable particles suspended in a static liquid medium under the action of an oscillating non-uniform electric field generated by polynomial electrodes. We compare the simulated distributions with experimental ones both for micro- (MDA-MB-231 breast tumor cells) and nano-(multiwall carbon nanotubes) particles. In both cases the equilibrium distributions near the electrodes are dominated by dipole interactions which locally enhance the DEP effect and promote long particles chains.