Archive

933 posts

Showing results for: DU

Impact of a pulsed electric field on damage of plant tissues: effects of cell size and tissue electrical conductivity.

Research RF Safe Research Library Jan 1, 2011

This experimental and modeling study examined pulsed electric field (PEF) permeabilization in several fruit and vegetable tissues at 293 K using 1000 μs pulses and field strengths of 400 and 1000 V·cm(-1). While electroporation theory predicts greater damage in tissues with larger cells, the authors report this…

Increased blood oxygen level-dependent (BOLD) sensitivity in the mouse somatosensory cortex during electrical forepaw stimulation using a cryogenic radiofrequency probe.

Research RF Safe Research Library Jan 1, 2011

This engineering-focused mouse fMRI study evaluated a 400-MHz cryogenic RF probe (CryoProbe) versus a conventional room-temperature surface coil during electrical forepaw stimulation. The CryoProbe increased image SNR and temporal SNR and reduced temporal noise compared with the room-temperature coil. The authors…

Reduction of implant RF heating through modification of transmit coil electric field.

Research RF Safe Research Library Jan 1, 2011

This engineering study describes modifying MRI RF transmit coil electric-field distributions to create electric field-free zones without substantially changing transmit sensitivity. Phantom experiments are reported to show reduced implant heating when a zero electric-field plane is aligned with the implant location.…

Impact of a static magnetic field on the electricity production of Shewanella-inoculated microbial fuel cells.

Research RF Safe Research Library Jan 1, 2011

This study investigated how exposure to a static magnetic field affects electricity production in Shewanella-inoculated microbial fuel cells across different reactor configurations. A 100 mT field was reported to increase maximum voltage and the effect was described as immediate and reversible, with possible adverse…

Transient and steady-state magnetic fields induce increased fluorodeoxyglucose uptake in the rat hindbrain.

Research RF Safe Research Library Jan 1, 2011

This animal PET study examined whether a weak 60-Hz magnetic field alters brain glucose utilization in rats. The abstract reports increased FDG uptake in hindbrain voxels when a 2.5-G field was oriented orthogonally to the sagittal plane, but not when field direction varied randomly. Distinct activation effects were…

Human keratinocytes in culture exhibit no response when exposed to short duration, low amplitude, high frequency (900 MHz) electromagnetic fields in a reverberation chamber.

Research RF Safe Research Library Jan 1, 2011

This in vitro study exposed normal human epidermal keratinocytes to non-thermal 900 MHz electromagnetic fields in a mode-stirred reverberation chamber under two short-duration conditions. Microarray analysis found only limited gene modulation (20 genes) with small expression ratios and no shared genes across…

Correction of main and transmit magnetic field (B0 and B1) inhomogeneity effects in multicomponent-driven equilibrium single-pulse observation of T1 and T2.

Research RF Safe Research Library Jan 1, 2011

This methods paper addresses how B0 (main field) and B1 (transmit field) inhomogeneities can bias SPGR and bSSFP steady-state MRI signals used for multicomponent T1/T2 relaxometry and myelin water analysis. It describes using DESPOT1-HIFI to calibrate flip angles and adding a B0-related parameter with multiple…

Frequency-dependent electrodeformation of giant phospholipid vesicles in AC electric field.

Research RF Safe Research Library Jan 1, 2010

This paper presents a theoretical model of giant phospholipid vesicle deformation in an alternating-current electric field, based on minimizing membrane bending energy and electric-field energy. The model treats the membrane and surrounding aqueous media as leaky dielectrics and reports good quantitative agreement…

Ohmic heating of peaches in the wide range of frequencies (50 Hz to 1 MHz).

Research RF Safe Research Library Jan 1, 2010

This engineering/food science study examined ohmic heating of peaches at 60 V/cm using bipolar pulses across frequencies from 50 Hz to 1 MHz. Heating time to a target temperature and multiple electrical properties were frequency-dependent, particularly for intact tissue. The authors report faster electro-thermal…

Disintegration efficiency of pulsed electric field induced effects on onion (Allium cepa L.) tissues as a function of pulse protocol and determination of cell integrity by ¹H-NMR relaxometry.

Research RF Safe Research Library Jan 1, 2010

This experimental study examined how pulsed electric field (PEF) processing parameters affect cell membrane rupture in onion tissue disks, using ion leakage as the primary integrity measure. Disintegration efficiency increased with field strength up to 500 V/cm and varied with pulse width, pulse number, and…

High-intensity pulsed electric fields processing parameters affecting polyphenoloxidase activity of strawberry juice.

Research RF Safe Research Library Jan 1, 2010

This study evaluated high-intensity pulsed electric fields (HIPEF) as a processing method to inactivate polyphenoloxidase (PPO) in strawberry juice. Using response surface methodology at a constant electric field of 35 kV/cm, the authors report strong PPO reductions across tested parameter ranges. Bipolar mode,…

Spin current pumped by a rotating magnetic field in zigzag graphene nanoribbons.

Research RF Safe Research Library Jan 1, 2010

This theoretical study models electron spin resonance and spin/charge pumping in zigzag graphene nanoribbons driven by a transverse rotating magnetic field without applied bias. It reports that pumped spin current density increases with ribbon size and rotating-field intensity, and that even-chain ribbons can also…

High magnetic field induced charge density waves and sign reversal of the Hall coefficient in graphite.

Research RF Safe Research Library Jan 1, 2010

This condensed-matter study investigates highly oriented pyrolytic graphite under very strong magnetic fields at low temperature. It reports a magnetic-field-induced charge density wave transition and a subsequent sign reversal of the Hall coefficient from negative to positive. The reported angular dependence…

The effect of magnetic field and disorders on the electronic transport in graphene nanoribbons.

Research RF Safe Research Library Jan 1, 2010

This paper presents a mesoscopic transport modeling framework (NEGF plus a real-space π-orbital model) to study how a uniform perpendicular magnetic field affects electronic transport in armchair graphene nanoribbons. The authors report width-dependent equilibrium current profiles and edge-localized transport under…

Anomalous magnetic field dependence of Y Ba(2)Cu(3)O(7 - δ): effect of orthorhombic distortion.

Research RF Safe Research Library Jan 1, 2010

This paper presents a theoretical model to investigate the origin of a mixed symmetry pairing state in the high-Tc superconductor YBa2Cu3O7-δ under applied magnetic fields between Hc1 and Hc2. The authors report that the model’s results, and their stated agreement with relevant experimental data, suggest orthorhombic…

Quantitative determination of domain distribution in SrTiO3-competing effects of applied electric field and mechanical stress.

Research RF Safe Research Library Jan 1, 2010

This neutron diffraction study quantifies how tetragonal structural domains in SrTiO3 redistribute below 105 K under external electric fields and uniaxial mechanical stress. The authors report that electric field and stress act competitively, and that applying both produces complex domain redistribution. The results…

Thermodynamic behavior of the XXZ Heisenberg s = 1/2 chain around the factorizing magnetic field.

Research RF Safe Research Library Jan 1, 2010

This paper theoretically investigates zero- and finite-temperature behavior of an anisotropic antiferromagnetic Heisenberg XXZ spin-1/2 chain under a transverse magnetic field, focusing between the factorizing and critical fields. It reports an entanglement phase transition at the factorizing field where entanglement…

Effect of two length scales on the properties of MgB(2) for arbitrary applied magnetic field.

Research RF Safe Research Library Jan 1, 2010

This paper analyzes anomalous magnetic-field and temperature dependences observed in MgB(2) superconductivity experiments using a two-order-parameter Ginzburg-Landau theory with two length scales. The authors numerically solve the nonlinear Ginzburg-Landau equations for arbitrary applied fields between Hc1 and Hc2 to…

The modulation of the de Haas-van Alphen effect in graphene by electric field.

Research RF Safe Research Library Jan 1, 2010

This theoretical/physics paper examines how an in-plane uniform electric field affects the de Haas-van Alphen (dHvA) effect in graphene. It reports that magnetization, magnetic susceptibility, and dHvA oscillation behavior depend on a dimensionless parameter β = E/(vF B), with divergences described at a critical…

Spin polarization induced by in-plane electric and magnetic fields in two-dimensional heavy-hole systems.

Research RF Safe Research Library Jan 1, 2010

This theoretical study uses a nonequilibrium Green function approach to analyze current-induced spin polarization in a two-dimensional heavy-hole system with cubic Rashba spin-orbit coupling under in-plane electric and magnetic fields. The authors report monotonic decreases in longitudinal conductivity with…

Surface superconducting states in a yttrium hexaboride single crystal in a tilted magnetic field.

Research RF Safe Research Library Jan 1, 2010

This experimental study examined nucleation of superconductivity at the surface of a single-crystal yttrium hexaboride (YB6) in a tilted dc magnetic field. The authors measured Hc3 on each side of the sample as a function of the angle between the field and the surface. They report Hc3/Hc2 ≈ 1.28 for a perpendicular…

An extension of the Czjzek model for the distributions of electric field gradients in disordered solids and an application to NMR spectra of 71Ga in chalcogenide glasses.

Research RF Safe Research Library Jan 1, 2010

This paper discusses the Czjzek model for distributions of electric field gradient (EFG) tensors in disordered solids and highlights its underlying assumptions and characteristics. It then introduces an extended model that combines a defined local EFG environment with an adjustable Gaussian (Czjzek) noise term to…

Slow relaxation of magnetoresistance in AlGaAs-GaAs quantum well structures quenched in a magnetic field.

Research RF Safe Research Library Jan 1, 2010

This study reports slow relaxation of magnetoresistance in selectively doped p-GaAs-AlGaAs structures following application of a magnetic field. The authors emphasize efforts to rule out temperature fluctuation artifacts and state that the main relaxation features remain. They interpret the phenomenon using a…

Electric field induced structuring in clay-oil suspensions: new insights from WAXS, SEM, leak current, dielectric permittivity, and rheometry.

Research RF Safe Research Library Jan 1, 2010

This laboratory/engineering study examined electric-field-induced structuring in clay-oil suspensions using WAXS, SEM, rheometry, and electrical measurements. Particle orientation was quantified via an orientational order parameter derived from diffraction peak azimuthal changes, and chain versus column formation was…

Ultrasonic propagation velocity in magnetic and magnetorheological fluids due to an external magnetic field.

Research RF Safe Research Library Jan 1, 2010

This engineering-focused study measured ultrasonic propagation velocity in hydrocarbon-based magnetic and magnetorheological fluids under an external magnetic field. The authors report that clustering structures formed in the fluids influence ultrasonic propagation velocity, with observed hysteresis and anisotropy.…

← Prev Page 34 / 38 Next →