نتایج جستجو برای: static coil

تعداد نتایج: 132066  

2015
Yongli Liang Lizhong Xu

In this study, the authors proposed an electromagnetic harmonic movable tooth drive system. , The forced response equation of the drive system to exciting currents was developed. Using this equation, the forced responses of the drive system to exciting currents were investigated. The results show that the forced responses of the drive system to the exciting currents were affected by mechanical ...

2001
Aysen Arsoy Yilu Liu Paulo. F. Ribeiro

This paper discusses the incorporation of a Superconducting Magnetic Energy Storage (SMES) coil into a voltage source inverter based static synchronous compensator (StatCom) in damping dynamic oscillations in power systems. A 100 MJ 96 MW (peak) SMES coil is attached to the voltage source inverter front end of a 160 MVA StatCom via a dc-dc chopper. The performance of the StatCom, a self-commuta...

Journal: :iranian journal of medical physics 0
m.a. oghabian associate professor, physics and biomedical engineering, tehran university of medical sciences, tehran, iran. research center for science & technology in medicine, imam khomeini hospital, tehran. iran. sh. mehdipour m.sc. in research center for science & technology in medicine, imam khomeini hospital, tehran. iran. n. riahicalam associate professor, physics and biomedical engineering, tehran university of medical sciences, tehran, iran. research center for science & technology in medicine, imam khomeini hospital, tehran. iran. b. rafie b. sc. in medical imaging center, imam khomeini hospital, tehran university of medical sciences, tehran, iran. h. ghanaati associate professor, radiology dept., medical imaging center, imam khomeini hospital, tehran university of medical sciences, tehran, iran.

introduction: one of the major causes of image non-uniformity in mri is due to the existence of  non-homogeneity in rf receive and transmit. this can be the most effective source of error in  quantitative  studies  in  mri  imaging.  part  of  this  non-homogeneity  demonstrates  the  characteristics of rf coil and part of it is due to the interaction of rf field with the material being  imaged...

2009
G. Ferrand M. Luong P. Chauvet M. A. Cloos A. Amadon

INTRODUCTION The knowledge of the complex-valued + 1 B map generated by each channel of a phased-array RF coil has become essential for high field MRI systems operating above 7 T, a cornerstone for static or dynamic shimming techniques, whose aim is to provide a uniform excitation over any region of interest (ROI). The maps must be measured experimentally for each RF coil and each subject under...

1998
David C. Meeker Eric H. Maslen Rogers C. Ritter Francis M. Creighton

Very small implanted permanent magnets guided by large electromagnetic coils have been proposed previously as a method for delivering hyperthermia to or guiding catheters through brain tissue. This procedure is termed “magnetic stereotaxis.” Early efforts employed a single coil on a movable boom, a design that proved logistically difficult to use on human patients. The present work deals instea...

2008
Q. Shen T. Q. Duong

INTRODUCTION Arterial spin labeling (ASL) technique has been widely used to measure cerebral blood flow (CBF) in animals and humans. This approach uses “pair-wise” subtraction of alternate images taken with labeled and non-labeled conditions to obtain a difference signal that arises only from inflowing “labeling” water. Although the static tissue signal from static brain water is subtracted out...

Journal: :journal of heat and mass transfer research(jhmtr) 2014
seyed faramarz ranjbar mir hatef seyyedvalilu

helical coil heat exchangers are widely used in industrial applications ranging fromcryogenic processes, air-conditioning, and nuclear reactors to waste heat recovery due totheir compact size and high heat transfer coefficient. in this kind of heat exchangers, flowand heat transfer are complicated. this paper reports a numerical investigation of theinfluence of different parameters such as coil...

2012
C. P. Oden

Several experimental time-domain EM induction instruments have recently been developed for unexploded ordnance (UXO) detection and characterization that use multiple transmitting and receiving coil combinations. One such system, the US Geological Survey’s ALLTEM system, is unique in that it measures both the electrodynamic response (i.e., induced eddy currents) and the magneto-static response (...

Journal: :Magnetic resonance in medical sciences : MRMS : an official journal of Japan Society of Magnetic Resonance in Medicine 2007
Hiroyuki Muranaka Takayoshi Horiguchi Shuji Usui Yoshitake Ueda Osamu Nakamura Fumiaki Ikeda

PURPOSE We evaluated radiofrequency (RF) heating of a humerus implant embedded in a gel phantom during magnetic resonance (MR) imaging for the specific absorption rate (SAR), angle between the implant and static magnetic field (B(0)), and position of the implant in the irradiation coil. METHODS We embedded a stainless steel humerus implant 2 cm deep in tissue-equivalent loop and mass phantoms...

A Andisheh-Tadbir A Haghnegahdar A Zamani, Gh Mortazavi, H Khosrovpanah H Parsaei, M Haghani M Saeedi Moghadam M Shojaei Fard O Koohi SMJ Mortazavi,

Background: Effects of electromagnetic fields on healing have been investigated for centuries. Substantial data indicates that exposure to electromagnetic field can lead to enhanced healing in both soft and hard tissues. Helmholtz coil is a device that generates pulsed electromagnetic fields. Objective: In this study, a pair of Helmholtz coils for enhancing thehealing process in periodontitis w...

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