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...

In this study, a reputable Kalina cycle system, KCS 11, is simulated and analysed. Within this efficient cycle, there are three heat exchangers: the first heat exchanger is designated for heat absorption from the heat source, the second heat exchanger is designed for heat release to the cold source, and the third heat exchanger is designed for energy recovery. In order to achieve precise si...

Joule-Thomson cooling systems are used in refrigeration and liquefaction processes. There are extensive studies on Joule-Thomson cryogenic systems, but most of them coverage steady state conditions or lack from experimental data. In the present work, transient thermal behavior of Joule-Thomson cooling system including counter current helically coiled tube in tube heat exchanger, expansion valve...

AIMS In end-stage heart failure, an alteration in the expression of the Na+-Ca2+ exchanger has been reported. Regulation of its expression is largely unknown. We sought to find out whether Na+-Ca2+ exchanger in human heart failure is regulated by sympathetic activation. In addition, since Na+-Ca2+-exchange is electrogenic, we conjectured whether increased expression of Na+-Ca2+ exchanger is ass...

In present work, comparison of three different tube bundles for particular heat exchanger is proposed. Three types are smooth, micro finned and corrugated tubes. Heat exchanger will be designed with smooth tube bundle and simulated. Micro fin and corrugation over tube is applied separately for same heat exchanger in feasible size and simulated for performance. Besides, comparison is done with h...

The present study reports on the location of the Na(+)-Ca2+ exchanger in cardiac sarcolemma with immunofluorescence and immunoelectron microscopy. Both polyclonal and monoclonal antibodies to the Na(+)-Ca2+ exchanger were used. The mAb was produced from a hybridoma cell line generated by the fusion of mouse myeloma NS-1 cells with spleen cells from a mouse repeatedly immunized with isolated rec...

Xie Y, Ottolia M, John SA, Chen J, Philipson KD. Conformational changes of a Ca -binding domain of the Na /Ca exchanger monitored by FRET in transgenic zebrafish heart. Am J Physiol Cell Physiol 295: C388–C393, 2008. First published June 11, 2008; doi:10.1152/ajpcell.00178.2008.—The Na /Ca exchanger is the major Ca extrusion mechanism in cardiac myocytes. The activity of the cardiac Na /Ca exch...

Task I: Source Requirements and Scaling Relationships ................................................................................ 9 Vehicle Dependent: Power, Range, Run time .............................................................................................. 9 Flux and Heat Exchanger Requirements........................................................................................

Title of Document: DEVELOPMENT OF AN ADVANCED HEAT EXCHANGER MODEL FOR STEADY STATE AND FROSTING CONDITIONS Varun Singh Doctor of Philosophy, 2009 Directed By: Reinhard Radermacher, Professor Department of Mechanical Engineering Air-to-refrigerant fin-and-tube heat exchangers are a key component in the heating, air conditioning and refrigeration industry. Considering their dominance, the indust...