نتایج جستجو برای: frequency measurement

تعداد نتایج: 899245  

Journal: :فیزیک زمین و فضا 0
محمد حامدپور دارابی استادیار، گروه فیزیک، دانشگاه هرمزگان، ایران مریم نورافشان مربی، گروه فیزیک، دانشگاه هرمزگان، ایران جان دیرینگ استاد، گروه جغرافیا، دانشگاه لیورپول، انگلستان

using a magnetic property measurement system (mpms), we measure magnetic susceptibility continuously at frequencies from 0 to 1000 hz for three different superparamagnetic (sp) grain sizes of magnetite (5nm, 7 nm and 10 nm) suspended in hydrocarbons (ferrofluids). our results confirm non-zero values of frequency-dependent susceptibility in the fine tail of nano-sized grains and provide new empi...

Journal: :journal of sciences islamic republic of iran 0

we propose a scheme for localizing an atom in a four-level configuration inside a classical standing wave field, conditioned upon the measurement of frequency of a weak probe field. in the classical standing wave field, the interaction between the atom and the field is position dependent due to the rabi-frequency of the driving field. hence, as the absorption frequency of the probe field is mea...

2002
Arnoud P. van der Wel Eric A. M. Klumperink Bram Nauta

A measurement technique [1] is presented that allows measurement of MOSFET low frequency (LF) noise under large signal RF (Radio Frequency) excitation. Measurements indicate that MOSFETS exhibit a reduction in LF noise when they are cycled from inversion to accummulation and that this reduction does not depend on the frequency of excitation for excitation frequencies of up to 3 GHz. The measure...

Journal: :Optics letters 2012
Shilong Pan Jianbin Fu Jianping Yao

A photonic approach to the simultaneous measurement of the frequency, pulse amplitude (PA), pulse width (PW), and time of arrival (TOA) of an unknown pulsed microwave signal is proposed and demonstrated. The measurement is performed based on optical carrier-suppressed modulation, complementary optical filtering, low-speed photodetection, and electrical signal processing. A proof-of-concept expe...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه صنعتی خواجه نصیرالدین طوسی - دانشکده مهندسی برق و کامپیوتر 1391

power transformers are important equipments in power systems. thus there is a large number of researches devoted of power transformers. however, there is still a demand for future investigations, especially in the field of diagnosis of transformer failures. in order to fulfill the demand, the first part reports a study case in which four main types of failures on the active part are investigate...

Journal: :international journal of advanced design and manufacturing technology 0
mohammadmahdi amiri phd student center of excellence in precision dimensional measurement technology development institute (tdi), acecr, sharif university branch. tehran, iran. m. tabatabaee ghomi assistant professor center of excellence in precision dimensional measurement technology development institute (tdi), acecr, sharif university branch. tehran, iran. *corresponding author gh. liaghat full professor mechanical engineering department tarbiat modares university tehran, iran.

in this paper a new method for nondestructive testing or nondestructive evaluation is proposed for glass-epoxy composite. for this purpose, impact-echo is used to evaluate the properties of composite materials, detecting internal defects and thickness measurement. in the impact-echo method a steel ball impacts on a composite plate and generates stress waves or p-waves which will be transferred ...

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