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Showing results for: temperature

The influence of temperature and electric field history on the conductivity of the charge density wave system o-TaS3.

Research RF Safe Research Library Jan 1, 2010

This laboratory study examined how temperature and prior electric-field exposure affect low-field conductivity in the charge density wave material o-TaS3. Conductivity differed between cooling and heating below the CDW transition, and applying increasing electric fields drove the system toward a stable,…

Nanocrystalline hydroxyapatite bioceramic using microwave radiation: Synthesis and characterization.

Research RF Safe Research Library Jan 1, 2010

This engineering/materials study synthesized nanocrystalline hydroxyapatite bioceramic powder using microwave radiation and then characterized the resulting material. The authors report highly crystalline HAp nanopowder with nanoscale size, mixed morphology, and elemental composition consistent with the HAp phase.…

Apparent violation of the Wiedemann-Franz law near a magnetic field tuned metal-antiferromagnetic quantum critical point.

Research RF Safe Research Library Jan 1, 2008

This paper reports calculations of interlayer electrical and thermal resistivity in a layered metal assuming Fermi-liquid quasiparticles inelastically scattered by two-dimensional antiferromagnetic spin fluctuations. The model yields linear-in-temperature behavior over a broad range and suggests that extrapolations…

Silicon-on-insulator-based radio frequency single-electron transistors operating at temperatures above 4.2 K.

Research RF Safe Research Library Jan 1, 2008

This engineering study demonstrates a silicon-on-insulator (SOI) radio-frequency single-electron transistor (RF-SET) operating at temperatures above 4.2 K. The device was optimized to address high resistance in SOI SETs and showed stable transport characteristics after repeated thermal cycling. RF-SET operation was…

Effect of temperature (-5 to 130 degrees C) and fiber direction on the dielectric properties of beef Semitendinosus at radio frequency and microwave frequencies.

Research RF Safe Research Library Jan 1, 2008

This study measured dielectric properties of beef Semitendinosus across 27, 915, and 1800 MHz and temperatures from -5 to 130 °C using an open-ended coaxial probe. The results indicate that frequency, temperature, and muscle fiber orientation influence dielectric constant, dielectric loss, and calculated penetration…

Plasma-assembled carbon nanotubes: electric field-related effects.

Research RF Safe Research Library Jan 1, 2008

This engineering-focused paper compares carbon nanotube growth in dense low-temperature plasma versus on a substrate surface using hybrid/Monte-Carlo simulations. It reports that plasma parameters strongly influence ion fluxes and nanotube growth kinetics, with large differences in growth rates and fluxes between…

[Microstrip antenna design and system research of radio frequency identification temperature sensor].

Research RF Safe Research Library Jan 1, 2008

This engineering paper introduces an RFID sensor network concept integrating RFID with wireless sensor networks and emphasizes the role of antennas. It discusses coil, dipole, and microstrip antennas and reports designing a microstrip antenna for a wireless temperature monitoring and control system. Measurements are…

Radiofrequency dosimetry in subjects implanted with metallic straight wires: a numerical study.

Research RF Safe Research Library Jan 1, 2008

This numerical FDTD study modeled RF exposure at 900 and 1800 MHz in tissue containing thin metallic straight wire implants. The model indicates that the wire can substantially increase local SAR, creating high SAR gradients. Despite this, the authors report that exposures below current safe levels resulted in…

Combined effect of temperature and pulsed electric fields on apple juice peroxidase and polyphenoloxidase inactivation.

Research RF Safe Research Library Jan 1, 2008

This laboratory study evaluated pulsed electric fields (PEF) combined with preheating to inactivate peroxidase (POD) and polyphenoloxidase (PPO) in freshly prepared apple juice. The highest reported inactivation occurred with preheating to 50°C and PEF at 40 kV/cm for 100 μs, exceeding the reductions seen with…

In-line application of electric field in capillary separation systems: Joule heating, pH and conductivity.

Research RF Safe Research Library Jan 1, 2008

This engineering study investigated factors affecting current when an electric field is applied in-line in a capillary separation system. Temperature measurements and a replicated cooling setup were used to estimate Joule heating effects, which were reported to be relatively small. In contrast, significant pH shifts…

A benzene-core trinuclear GdIII complex: towards the optimization of relaxivity for MRI contrast agent applications at high magnetic field.

Research RF Safe Research Library Jan 1, 2008

This chemistry/engineering study reports the synthesis and NMR/MRI-relevant characterization of a trinuclear Gd(III) chelate intended for high-field MRI contrast applications. Using 17O NMR and proton relaxivity across multiple fields and temperatures, the authors infer bishydration, quantify water exchange and…

Dependence of RF heating on SAR and implant position in a 1.5T MR system.

Research RF Safe Research Library Jan 1, 2007

This phantom study measured RF-induced heating of a stainless steel humerus implant during 1.5T MR imaging while varying SAR, implant angle to B0, and implant position in the RF coil. Temperature rise at implant tips increased linearly with SAR, with larger rises when the implant was parallel to B0. Heating decreased…

Magnetic field switching between the two orbital-ordered states in DyVO3.

Research RF Safe Research Library Jan 1, 2007

This Physical Review Letters study investigates phase competition between spin- and orbital-ordered states in a DyVO3 single crystal. The abstract reports reentrant temperature-driven transitions in spin ordering and orbital ordering. It also reports that an applied magnetic field can switch between orbital-ordered…

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