In this paper, a new method for designing an active dual-band dipole antenna is proposed. The operating frequencies of the proposed antenna are 150 and 450 MHz that are usually used in military applications. Using a series stub is the main idea in the proposed dual-band antenna, where it makes an independent resonance frequency higher than the main resonance frequency of a conventional dipole. ...

Premature combustion that affects outputs, thermal efficiencies and lifetimes of internal combustion engine is called “knock effect”. However knock signal detection based on acoustic sensor is a challenging task due to existing of noise in the same frequency spectrum. Experimental results revealed that vibration signals, generated from knock, has certain frequencies related to vibration resonan...

thisis a case report of a 24-year-old man who presented with increased pain and firm swelling of the right foot after a minor twisting injury. radiography, computed tomography (ct) and magnetic resonance imaging (mri) findings showed ancillary information that was helpful for surgical treatment. the final diagnosis was confirmed aschondroblastoma of the navicular bone based on the pathology rep...

conclusions although in our study washout pattern was the most powerful indicator for malignant pathology in non mass like enhancing lesions, more studies with larger sample size needs in this regard. background several studies on the diagnostic efficacy of mri has not real consensus for the accuracy of mri characteristics in non mass like breast lesions, and the number of malignant lesions in ...

the silver spr chip was modified by alkaline-silane condensation with aminopropyltriethoxysilane (aptes) in naoh aqueous solution at different times. silver sputtered slides coated with aptes were immersed in naoh solution, enabling us to produce silver surfaces homogeneously covered with aptes. the surface properties of grafted aptes on sputtered silver surface as a occasion of time were studi...

in this paper, a novel decision based median (dbm) filter for enhancing mr images has been proposed. the method is based on eliminating impulse noise from mr images. a median-based method to remove impulse noise from digital mr images has been developed. each pixel is leveled from black to white like gray-level. the method is adjusted in order to decide whether the median operation can be appli...

brachial plexus injury (bpi) is an uncommon complication of median sternotomy capable of causing a permanent or transitory sensitivity and/or motor function impairment in the upper limbs. during a cardiac surgery through sternotomy, for the assessment of the thoracic cage configuration and the site of mediastinal structures, a broader surgical field may be required. if the sternal retractors ar...

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conclusion distinct neurochemical and histological structure changes (cortico-striatal-thalamic-cortical cycle) exist in patients with first-episode ocd. 1h-mrs is capable of identifying these changes by assessing metabolic abnormalities. objectives this study aims to use magnetic resonance spectroscopy (mrs) to discover substance-metabolism abnormalities of brain circuits in patients with firs...