Jim Shewchun

Learn More
In this review paper we show that MIS (metal-insulator-semiconductor) and SIS (semiconductor-insulator-semiconductor) solar cells are basically one and the same type of device, even though they are usually regarded as being separate and are reported as such. Experimental results on the two most common systems, Al-SiO<inf>x</inf>-pSi and(More)
A laser absorption spectrometer is described which employs a wavelength-tunable Pb(1-x) Sn(x) Se diode in conjunction with a multipass White cell and which is capable of measuring SO(2) concentrations in the low ppb range. We describe in some detail the modulation techniques used in signal detection which enable us to measure absorption coefficients as low(More)
In 16 consecutive patients, thrombosis, anastomotic and intragraft stenoses, and residual venous communications (arteriovenous fistulas [AVFs]), after in situ saphenous vein bypass of femoropopliteal and infrapopliteal arteries, were treated with interventional angiographic techniques. Streptokinase infusion for graft thrombosis was performed in four(More)
Direct puncture of a thrombosed lower extremity bypass graft may be the only angiographic access to the graft when it cannot be opacified or cannulated by conventional angiographic techniques. In I patient, fibrinolytic therapy was performed from this approach using the “crossed two catheter” technique previously described for thrombosed dialysis grafts.
Measurements have been made with a line tunable CO(2) laser on ozone in order to establish some useful criteria for pollution monitoring via the direct absorption scheme. The absorption coefficient a and the pressure dependence of the extinction coefficient k(nu)(P) at frequencies nu corresponding to the P(8) to P(36) vibration-rotation lines of the CO(2)(More)
Experimental coincidences between CO laser lines and seventeen NO lines have been observed. Three important parameters, the separation between each laser line and the nearest NO line (Deltanu), the pressure broadening parameter (gammaL degrees ), and the line strength ((Supsilon,J)), have been determined for each laser wavelength using the best match(More)
Low-dose catheter-directed fibrinolytic therapy (LDCF) using streptokinase (35) and urokinase (7) was performed on 42 separate occasions in 36 patients for recent lower extremity thromboembolic occlusion. Twenty-seven grafts and 15 native arteries were treated. Causes of occlusion were known in 32 instances: native artery proximal or distal occlusive(More)
In order to understand the photovoltaic effect in polycyrstalline GaAs MIS solar cells, we have studied the grain boundary problem. The grain boundary region width is assumed to be very small compared to the width of the depletion region. The mechanism for current conduction is tunneling through the insulator of a polycrystalline MIS diode. Theoretical(More)