This paper presents the analysin ,design and implementation of a high voltage ratio topology of DC-DC converter. The DC-DC converter has high voltage ratio with reduced input current, output voltage and output current ripple, and also reduces the voltage and current rating of power electronics components and compared with conventional boost converter. The voltage stress on the switches are  red...

OBJECTIVES The effects of operational modes of intra-aortic balloon pumping (IABP) on coronary haemodynamics and oxygen delivery/demand ratio are unknown and were investigated in an experimental model of myocardial ischaemia reperfusion. METHODS Healthy swine (n = 24) underwent 120-minute ligation of the left anterior descending coronary artery followed by 24 h of reperfusion and were randoml...

Objective(s): Use of a positron emission tomography (PET)/single-photonemission computed tomography (SPECT) system facilitates the simultaneousacquisition of images with fluorine-18 fluorodeoxyglucose (18F-FDG) andtechnetium (99mTc)-tetrofosmin. However, 18F has a short half-life, and 511keV Compton-scattered photons are detected in the 99mTc energy window.Therefore, in this study, we aimed to ...

Turbocharged CNG engines produce high NOx emission due to the fuel type and high combustion temperature. In this research, the effects of lean-burn and waste gate opening pressure threshold on NOx emission are studied theoretically and experimentally at WOT condition as well as 13-mode ECE-R49 test cycle. A code is developed in MATLAB environment for predicting engine NOx and the results are va...

PURPOSE We compared strain ratio vs. qualitative elastography for the further differentiation of focal breast lesions, with special focus on limiting factors. MATERIALS AND METHODS 215 patients with 224 histologically proven breast masses (116 malignant, 108 benign) were prospectively examined using a high-end ultrasound system (Philips iU22) with serial elastography function. B-mode scans an...

objective(s): use of a positron emission tomography (pet)/single-photonemission computed tomography (spect) system facilitates the simultaneousacquisition of images with fluorine-18 fluorodeoxyglucose (18f-fdg) andtechnetium (99mtc)-tetrofosmin. however, 18f has a short half-life, and 511kev compton-scattered photons are detected in the 99mtc energy window.therefore, in this study, we aimed to ...

results sixty patients were involved in this study. in asv mode, values including peak airway pressure (p-peak), end-tidal carbon dioxide (etco2), tidal volume and respiratory dead space were significantly lower than simv mode. although the mean value for dynamic compliance had no significant difference in the two types of ventilation, it was better in asv mode. methods in a crossover study, pa...

Mixed-mode, high-cycle fatigue-crack growth thresholds are reported for through-thickness cracks (large compared to microstructural dimensions) in a Ti±6Al±4V turbine blade alloy with a bimodal microstructure. Speci®cally, the e€ect of combined mode I and mode II loading, over a range of phase angles b ˆ tanÿ1…DKII=DKI† from 0° to 82° …DKII=DKI 0±7), is examined for load ratios (ratio of minimu...

A new mode of 0°–360° bistable twisted nematic ~BTN! liquid crystal display is developed by using a parameter space method. This new mode possesses a large dDn value that provides a possibility of using a 4.8–7 mm cell gap and a 6.5 V operating voltage for the new 0°–360° BTN cells. The high-contrast ratios above 80 within 280°–80° viewing-angle ranges are obtained experimentally in a horizonta...

We present an ultra-short distributed Bragg reflector fiber laser written in Er/Yb co-doped fiber. The entire laser is only 8.4 mm in length. The lasing threshold is less than 1 mW. The optical signal-to-noise ratio of the laser output is better than 70 dB. The laser emits two orthogonal polarization modes and generates a beat signal with signal-to-noise ratio of approximately 70 dB and 3-dB li...