OBJECTIVE It was the goal of this study to compare endothelium-dependent and endothelium-independent flow reserve in vascular regions supplied by the left internal mammary artery before and after bypass graft surgery. METHODS The native internal mammary artery in situ was investigated in 13 patients (age 61.8 +/- 8.0 years) with angiographically proven coronary artery disease. The internal ma...

electrochemical impedance spectroscopy (eis) is a suitable and powerful diagnostic testing method for fuel cells (fcs) since it is non-destructive and provides useful information about fc performance and its components. in this study, for the first time, a 500w cascade type 4 cells stack with integrated humidifier, water separator and internal manifolds was designed, fabricated and tested. the ...

2014 A junction was grown by d.c. sputtering of n-type silicon on a p-type crystalline substrate. Ohmic contacts were deposited by evaporation of aluminum. The junction obeyed Schottky model both under forward and reverse bias conditions, but with higher idealization factor « n » due to its high internal resistance. The 1/C2-V relation showed the presence of localized and interface states. The ...

Previous work from our laboratory has revealed that the intrinsic contractility of the left ventricle is depressed in rats at 24 months, and the ventricular internal resistance shows declines with age. The aim of this study was to determine whether food restriction (FR) delays the development of age-related changes in left ventricular (LV) contractility and internal resistance. Male Fischer 344...

Si composite negative electrodes for lithium secondary batteries degrade in the dealloying period with an abrupt increase in internal resistance that is caused by a breakdown of conductive network made between Si and carbon particles. This results from a volume contraction of Si particles after expansion in the previous alloying process. Due to the large internal resistance, the dealloying reac...

The internal resistance is the key parameter for determining power, energy efficiency and lost heat of a lithium ion cell. Precise knowledge of this value is vital for designing battery systems for automotive applications. Internal resistance of a cell was determined by current step methods, AC (alternating current) methods, electrochemical impedance spectroscopy and thermal loss methods. The o...

An upflow microbial fuel cell (UMFC) system with a U-shaped cathode inside the anode chamber was developed and produced a maximum volumetric power of 29.2 W/m3 at a volumetric loading rate of 3.40 kg COD/(m3 day) and an operating temperature of 35 degrees C while feeding sucrose continuously. The Coulombic efficiency decreased from 51.0% to 10.6% with the increase in the volumetric loading rate...

conditional monitoring is prerequisite to prevent severe damage or falling down the trees. problems such as trunk decays, reduces trees resistance against wind and floods. in this study, a mathematical modeling technique is being selected to determine the trees strength against such events. finally, an applicable model for safety factor was created by having numeral (dimensions of crown and tru...

BACKGROUND Hydraulic dilatation is a novel method of cervical dilatation that is based on continuous controllable dilatation (CCBD) by the pumping of fluid into the balloon extension of the system. The main advantage of this procedure is that it allows control of and insight into the process of cervical dilatation. METHODS For the purposes of our research, we created a new and upgraded system...