Increased concerns about climate change and day by day increment in energy cost has created the importance of Refrigeration & Air Conditioning system with high COP. COP of a Vapour Compression Refrigeration system is mainly influenced by the effectiveness of the Heat Exchanger being Employed. Optimization in the design of Heat Exchanger is highly desirable to improve their effectiveness and red...

The Na/Ca exchanger is associated with 160, 120 and 70 kDa polypeptides whose nature is poorly understood. We have purified and characterized the Na/Ca exchanger from bovine cardiac sarcolemmal vesicles (SLVs) by using ion-exchange and affinity chromatographies. The Na/Ca exchanger-enriched fraction was reconstituted into asolectin liposomes [lipid to protein ratio 10:1 (w/w)] that showed Na/Ca...

Park, Choon-Ok, Xiao-Hui Xiao, and David G. Allen. Changes in intracellular Na1 and pH in rat heart during ischemia: role of Na1/H1 exchanger. Am. J. Physiol. 276 (Heart Circ. Physiol. 45): H1581–H1590, 1999.—The role of the Na1/H1 exchanger in rat hearts during ischemia and reperfusion was investigated by measurements of intracellular Na1 concentration ([Na]i) and intracellular and extracellul...

Perturbations of Ca(2+) metabolism are central to the pathogenesis of cardiac hypertrophy. The electrogenic Na(+)-Ca(2+) exchanger mediates a substantial component of transmembrane Ca(2+) movement in cardiac myocytes and is up-regulated in heart failure. However, the role of the exchanger in the pathogenesis of cardiac hypertrophy is poorly understood. Thoracic aortic banding in mice induced 50...

The configuration of a plate heat exchanger comprises its number of plates, pass arrangement, location of the inlet and outlet connections and type of channel flow. The effective optimization of the configuration is a complex task since it is not possible to represent the mathematical model of the exchanger explicitly in the configuration elements. To overcome this limitation, the configuration...

The Na+/H+ exchanger is a pH-regulatory protein that extrudes one H+ ion in exchange for one Na+ ion when intracellular pH declines. A number of studies have shown phorbol ester stimulation of activity in intact cells, leading to the idea that the exchanger is regulated by protein kinase C-mediated phosphorylation in vivo. cDNA encoding the protein has been cloned, and a recent model suggests a...

An experimental study has been conducted to evaluate the performance of a compact round-tube louver-fin condenser, each with frontal areas of 0.25 m in both dry and wet conditions. Deluge water cooling is achieved by incorporating a perforated bottom plate-type water distributor on top of the round tube heat exchanger. Water is used as a refrigerant, and enters the heat exchanger tubes at 35°C ...

The reduction of SO2 and PM for marine engines was investigated using the electrostatic precipitator (ESP) with the heat exchanger. The experiments were carried out to reduce SO2 due to condensation of water in the exhausted gas. The experimental system consists of the diesel engine, the heat exchanger and the ESP. The exhausted gas at 180 o C of the temperature is cooled to 20 o C, and generat...

With distributed power generation market, the most economical solution today is to generate power through small gas turbine systems, arbitrarily categorized as microturbines (5 – 200 kW) and miniturbines (200 – 500 kW). The thermal efficiency of such microturbines is about 20% or less if no recuperator is used in the system. Using a recuperator (regenerator can also be considered but has a numb...

BACKGROUND In the failing human heart, sarcoplasmic reticulum (SR) calcium handling is impaired, and therefore, calcium elimination and diastolic function may depend on the expression of sarcolemmal Na+-Ca2+ exchanger. METHODS AND RESULTS Force-frequency relations were studied in ventricular muscle strip preparations from failing human hearts (n=29). Protein levels of Na+-Ca2+ exchanger and S...