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14 posts

Filters: category: Engineering & Measurement Clear

The Effect of Proximity Sensor & Grip Sensor Use on Specific Absorption Rate (SAR) in Smartphones

Research RF Safe Research Library Jan 1, 2025

This engineering study examined how smartphone proximity and grip sensors affect SAR during LTE and 5G NR operation in a 3D measurement environment. The abstract reports that enabling these sensors reduces SAR relative to being turned off, with reductions varying by sensor and frequency. The authors attribute the…

Magnetic characterization of Mumetal® for passive shielding of stray fields down to the nano-Tesla level

Research RF Safe Research Library Feb 1, 2021

This engineering study addresses stray magnetic fields as a performance-limiting imperfection for the Compact Linear Collider (CLIC), where simulations indicate sensitivity to fields on the order of 0.1 nT. It presents DC and AC magnetic characterization of two Mumetal® samples (annealed in final form vs…

Electromagnetic Field Analysis of Low-Magnitude High-Frequency Vibrator with Multiple Plungers.

Research RF Safe Research Library Jan 1, 2018

This conference paper describes an engineering design for a low-magnitude high-frequency vibrator with multiple plungers, aiming to minimize electromagnetic fields during vibrational stimulation experiments. The authors analyze the device’s EMF using finite element methods in COMSOL. No direct biological or health…

Characterization of thrombus stiffening in radio frequency (rf) Mechanical thrombectomy.

Research RF Safe Research Library Jan 1, 2016

This engineering-focused conference paper characterizes thrombus stiffening after radio frequency (rf) electric current treatment in the context of intra-arterial mechanical thrombectomy. The abstract reports thrombus stiffness increased by more than eightfold after rf treatment, attributed to increased crosslinking.…

Strain in YBCO Double-Pancake Coil With Stainless Steel Overband Under External Magnetic Field.

Research RF Safe Research Library Jan 1, 2015

This engineering study evaluates mechanical hoop strain in a YBCO coated-conductor double-pancake coil intended for a high-field HTS insert in an NMR magnet. The authors present experimental strain-gauge measurements and analytical stress/strain calculations for a coil operated with and without a stainless steel…

Magnetic field tunability of optical microfiber taper integrated with ferrofluid.

Research RF Safe Research Library Jan 1, 2013

This engineering study reports theoretical analysis and experimental demonstration of an S-tapered optical microfiber integrated with ferrofluid for magnetic-field tunability. The transmission spectrum and dip wavelengths were found to vary with magnetic-field intensity, with a Langevin-like response and a linear…

Tuning Mie scattering resonances in soft materials with magnetic fields.

Research RF Safe Research Library Jan 1, 2013

This paper proposes a reversible approach to tune Mie scattering resonances in random media using external low induction magnetic fields. The experimental demonstration uses ultrasound in emulsions of fluorinated ferrofluid droplets dispersed in a Bingham fluid. Magnetic-field-induced droplet deformation is reported…

Removal of earth's magnetic field effect on magnetoelastic resonance sensors by an antisymmetric bias field.

Research RF Safe Research Library Jan 1, 2012

This engineering study addresses measurement error in magnetoelastic resonance sensors caused by Earth's magnetic field. The authors present an antisymmetric magnetic bias field approach and compare the ribbon response to external perturbation fields against a conventional design. They report a 77% reduction in the…

Response identification in the extremely low frequency region of an electret condenser microphone.

Research RF Safe Research Library Jan 1, 2011

This engineering study describes an experimental setup using a small electret condenser microphone connected to a notebook/PC to detect extremely low frequency signals. Using a small air cell made from a drilled DVD plate with a speaker and microphone on opposite sides, the microphone captured signals in the 0.5–20…

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.…

Focused-ion-beam-assisted magnet fabrication and manipulation for magnetic field detection applications.

Research RF Safe Research Library Jan 1, 2009

This engineering study describes a focused-ion-beam-assisted technique for fabricating reduced-size NdFeB nanomagnets and integrating them onto a thin-film bulk acoustic resonator (FBAR). After bonding the magnet, the FBAR showed a downshift in resonance frequency and a reduced quality factor. The magnetic behavior…

Theory for nanoparticle retention time in the helical channel of quadrupole magnetic field-flow fractionation.

Research RF Safe Research Library Jan 1, 2009

This paper presents a theoretical treatment of nanoparticle retention in quadrupole magnetic field-flow fractionation (QMgFFF) using a helical separation channel. It defines the retention ratio as the ratio of transit times for non-retained versus retained material. Equations are derived for angular and longitudinal…

Surface-induced nonlinearities of liquid crystals driven by an electric field.

Research RF Safe Research Library Jan 1, 2008

This experimental physics study examines how a static electric field affects the optical nonlinearity of methyl-red doped nematic liquid crystals. The authors report that low voltages below the Fredericks transition threshold can change the optical nonlinearity by orders of magnitude. They state that the data fit a…

[Determination of electric field distribution in dielectric barrier surface glow discharge by spectroscopic method].

Research RF Safe Research Library Jan 1, 2008

This engineering study reports spectroscopic determination of net electric field distribution in a dielectric barrier surface glow discharge in low-pressure air. Optical emission spectroscopy was used to infer electric field distribution from the intensity ratio of nitrogen spectral lines at 391.4 nm and 337.1 nm.…

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