This study presents an innovative and simple way to increase the rate of heat transfer in a spiral plate heat exchanger model. Several circular cross-section rods, as continuous vortex generators, have been inserted within the spiral plate heat exchanger in the cross-stream plane. The vortex generators are located at various azimuth angles of α=30◦, 60◦, 90◦, and 120◦ with non-dimensional diame...

on the circular curve, lateral acceleration affects comfort. on the spiral, both lateral acceleration and jerk affect comfort.  the determination of maximum curving speed on the basis of lateral acceleration only is not critical because the lateral acceleration is proportional to the square of speed whereas jerk is proportional to cubic power of speed. the maximum speed on a curve is thus signi...

conclusions in most cases, the conus artery can be visualized in cardiac ct. a description of the conus artery should be a part of the standard clinical coronary ct angiography description. objectives to examine whether it is possible to visualize the conus artery in multi-slice computed tomography (ct). patients and methods in 79 consecutive patients (aged 56 ± 12.9 years; 13 women), 64-slice ...

in this study, generation of the transient evoked ooacoustic emissions in human ear has been simulated using a new electroacoustic model. the method of state variables was adopted to calculate the auditory model, and numerical integration methods have been used to solve differential equations in matlab. simulation results have been compared with the real data. in this study, latency curves, fre...

Introduction: Using computed tomography (CT) is increasing significantly in Iran and worldwide. Reduction of CT's radiation dose is a critical concern. The aim of this study was evaluating the effect of localizer kVp on spiral CT images when the tube current modulation (TCM) is activated. Materials and Methods: A special wedding cake phantom with circular in...

background and aims. the imaging techniques commonly used for foreign body detection include plain radiography, xeroradiography, computed tomography (ct) scans, magnetic resonance imaging (mri) and ultrasonography. the aim of the present study was to compare cone-beam computed tomography (cbct) with conventional ct scan in determination of the exact location of a foreign body in the maxillofaci...

the ribs are essential structures of the osseous thorax that provide certain significant information and aid interpretation of radiologic images in daily routine practice. intrathoracic rib is a rare congenital anomaly that is usually discovered incidentally, but may cause in vain interventions in case of being unaware. we herein report an intrathoracic rib in a girl whose chest x-ray was stran...

Background: X-ray computed tomography (CT) examinations deliver a significant amount of radiation doses to patients comparing to conventional radiography examinations. The objective of the current study was to analyze and investigate the average patient received dose from axial and spiral CT exams in a medical imaging center. Material and Methods: In this study, the patient imaging tec...

Formation and selection of multiarmed spiral wave due to spontaneous symmetry breaking are investigated in a regular network of Hodgkin-Huxley neuron by changing the excitability and imposing spatial forcing currents on the neurons in the network. The arm number of the multiarmed spiral wave is dependent on the distribution of spatial forcing currents and excitability diversity in the network, ...