Heat Transfer Study in a Pilot-Plant Scale Bubble Column

The Effects of Superficial Gas Velocity on Heat Transfer Coefficient and its Time-Averaged Radial Profiles Along the Bed Height Have Been Investigated in a Pilot-Plant Scale Bubble Column of 0.44. M Diameter using Air-Water System. Notable Differences Were Observed in Heat Transfer Coefficients Along the Bed Axial Locations Particularly between the Sparger (Z/D= 0.28) and the Fully Developed Flow (Z/D= 4.8) Regions. in the Fully Developed Flow Region Larger Heat Transfer Coefficient Values Were Obtained Compared to Those in the Sparger Region. About 14-22% Increase in Heat Transfer Coefficients Measured in the Fully Developed Flow Region Has Been Observed Compared to Those Measured in the Distributor Region When the Superficial Gas Velocity Increases from 0.05 to 0.45. M/s. the Heat Transfer Coefficients in the Column Center for All the Conditions Studied Are About 9-13% Larger Than Those Near the Wall Region. It Has Been Noted that in the Fully Developed Flow Region, the Axial Variation of the Heat Transfer Coefficients Was Not Significant. © 2010

Effects of pimobendan (UD-CG 115) on the contractile function of the normal and "postischemic" canine myocardium.

Pimobendan (UD-CG 115) is a long-acting positive inotropic drug with arterio- and venodilator properties. To determine to what extent this new agent is able to affect contractile function in previously ischemic areas of the left ventricle (LV), the effects of pimobendan on global and regional LV function were studied in eight conscious dogs, 2 days after a 2-h coronary occlusion followed by reperfusion. Before pimobendan, percentage of systolic shortening and mean velocity of shortening were lower in reperfused segments than in control areas (0.41 +/- 0.17 vs. 0.93 +/- 0.07 s-1 and 7 +/- 3 vs. 15 +/- 1%, respectively; both p less than 0.05). Infusion of 1 mg of pimobendan significantly improved peak + dP/dt (3202 +/- 372 to 3848 +/- 498 mm Hg/s; p less than 0.05) and ejection time (166 +/- 13 to 156 +/- 15 ms; p less than 0.05). Cumulative infusion up to 2.5 mg further improved these indexes to 5199 +/- 934 mm Hg/s and to 125 +/- 11 ms, (respectively; both p less than 0.05) without affecting mean arterial pressure (91 +/- 14 to 93 +/- 22 mm Hg; NS). Mean velocity of shortening rose to 1.18 +/- 0.09 s-1 (p less than 0.05) in control segments and to 0.62 +/- 0.18 s-1 (p less than 0.05) in reperfused segments. The ratio between end-systolic pressure and length increased by 26 +/- 9% (p less than 0.05) in the reperfused segments and by 20 +/- 8% (p less than 0.05) in control areas.(ABSTRACT TRUNCATED AT 250 WORDS