Search results for "Electric field"

Synthesis of Liquid-Crystalline Colloids in Nonpolar Media and their Manipulation in Electric Fields

2009

The first synthesis of anisotropic liquid-crystalline colloids in silicone oil by a direct (radical) polymerization of a monomer in THF/silicone oil mixtures with the help of siloxane containing stabilizers is described. The size of the colloids is in the lower μm range and can be adjusted by varying the mixture. The resulting colloids show a bipolar director configuration if they are small (<1.5 μm) and a radial configuration if they are larger. The colloids are sterically stabilized, and, due to the nonpolarity of the solvent, the disturbing effects of migrating ions are excluded and experiments in the electric field can be conducted. Both line formation in DC fields and a periodic switch…

Electrically Driven Magnetic Domain Wall Rotation in Multiferroic Heterostructures to Manipulate Suspended On-Chip Magnetic Particles

2015

In this work, we experimentally demonstrate deterministic electrically driven, strain-mediated domain wall (DW) rotation in ferromagnetic Ni rings fabricated on piezoelectric [Pb(Mg1/3Nb2/3)O3]0.66-[PbTiO3]0.34 (PMN-PT) substrates. While simultaneously imaging the Ni rings with X-ray magnetic circular dichroism photoemission electron microscopy, an electric field is applied across the PMN-PT substrate that induces strain in the ring structures, driving DW rotation around the ring toward the dominant PMN-PT strain axis by the inverse magnetostriction effect. The DW rotation we observe is analytically predicted using a fully coupled micromagnetic/elastodynamic multiphysics simulation, which v…

Electric Field Control of Spin-Dependent Dissipative Electron Transfer Dynamics in Mixed-Valence Molecules

2015

We demonstrate that the borderline class II/III magnetic MV dimers, which can be referred to as single molecule multiferroics, provide a unique possibility to achieve electric field control of the electron transfer (ET) dynamics. As an example, we consider a MV dimer d2-d1 in which an extra electron is delocalized over two spin-cores (s0 = 1/2), and the ET is spin-dependent due to the double exchange mechanism. It is assumed that the “extra” electron is coupled to the only intramolecular vibration, and a weak coupling to the dissipative subsystem (thermal bath) is taken into account. The vibronic energy levels and the wave functions of the isolated dimer (quantum part of the system) are num…

Complexity and Nonlinearity Analysis of the Time Series of Electric Field Intensity

2021

In this work, the conditional entropy (CE) and the method of surrogate data are applied on time series of electric field (EF) intensity to explore their degree of complexity and the possible presence of nonlinear dynamics. The time series were obtained during the wide-band cumulative EF intensity monitoring, performed by one sensor of the Serbian EMF RATEL monitoring system installed in the campus area of the University of Novi Sad, and are re-sampled at one sample per two hours over consecutive time epochs of one month duration. The field intensity measurements during the years 2019 and 2020 allowed us to explore the effects of mobility restrictions related to the COVID-19 pandemic on the …

Measurement of ultra-low heating rates of a single antiproton in a cryogenic Penning trap

2019

Physical review letters 122(4), 043201 (2019). doi:10.1103/PhysRevLett.122.043201

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…

New approaches for the effective valorization of papaya seeds: Extraction of proteins, phenolic compounds, carbohydrates, and isothiocyanates assiste…

2015

Abstract The study compares the efficiency of common aqueous extraction (CE) at different pH (2.5–11) and temperatures (20–60 °C) and extraction assisted by pulsed electric energy (pulsed electric fields, PEF or high voltage electrical discharges, HVED) of nutritionally valuable and antioxidant compounds from papaya seeds. The exponential decay pulses with initial electric field strengths of ≈ 13.3 kV/cm and ≈ 40 kV/cm for PEF and HVED treatments, respectively, were used. The number of pulses n was changed within 1–2000. The impacts of temperature and pH on extraction efficiency of different components (proteins, total phenolic compounds, carbohydrates, isothiocyanates) and antioxidant capa…

Impact of pulsed electric fields and high voltage electrical discharges on extraction of high-added value compounds from papaya peels

2014

Abstract Extraction of the nutritionally valuable and antioxidant compounds from papaya peels using conventional aqueous extraction (E) (at 20 °C, 50 °C, and 60 °C) and extraction assisted by pulsed electric field (PEF) or by high voltage electrical discharges (HVED) was studied. Increase of extraction temperature or extraction in basic media (pH = 11) not always resulted in an increase of the yields or TEAC values. E.g., the concentration of proteins and TEAC values at pH = 7 and pH = 11 were noticeably smaller at 60 °C as compared to those measured at 50 °C. HVED-assisted technique showed a higher extraction efficiency of high-added value compounds compared to PEF-assisted extraction. E.g…

Some effects of a buried electricity transmission cable on bulk soil.

2007

A case study in NW Italy investigating an underground electric line (1 m depth triple cable at operative voltages 220-380 kV) measured electric fields in the surrounding soil virtually close to zero but magnetic fields (microTs) 20 times the background level. After 6 months, the influence radius around the cable on microbial activity (estimated by soil ATP), organic carbon, and total nitrogen follows exactly the inverse trend of the MF, shifting the biological activity with a lag distance of 5 m from the 220 kV cable.

Fermi condensates for dynamic imaging of electromagnetic fields.

2008

Ultracold gases provide micrometer size atomic samples whose sensitivity to external fields may be exploited in sensor applications. Bose-Einstein condensates of atomic gases have been demonstrated to perform excellently as magnetic field sensors \cite{Wildermuth2005a} in atom chip \cite{Folman2002a,Fortagh2007a} experiments. As such, they offer a combination of resolution and sensitivity presently unattainable by other methods \cite{Wildermuth2006a}. Here we propose that condensates of Fermionic atoms can be used for non-invasive sensing of time-dependent and static magnetic and electric fields, by utilizing the tunable energy gap in the excitation spectrum as a frequency filter. Perturbat…