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Recently, certain oral contraceptive preparations have been found to affect the pituitary and adrenal cortical secretions ( 1-3). Some oral contraceptive pills have been reported to cause changes in carbohydrate (4-6), fat (7, 8), and protein (9) metabolism. Progesterone was found to increase the secretion of mineralocorticoids from the adrenal (10, 11). This change in secretion rates of mineralocorticoids might be expected to change the mineral metabolism of those taking oral contraceptive pills. The present studies were designed to determine whether the digestibility and retention of various nutrients were affected by feeding female rats for short and long periods, norethynodrel and mestranol, the synthetic progestational and estrogenic compounds used in the preparation of several oral contraceptives. The present experiments were also undertaken to study whether these oral steroids would alter body composition and to determine whether the alterations were reversible upon withdrawal of the steroids. Methods. Ninety 3-week-old IfemaleSprague-Dawley rats were fed a basal grain ration3 until they were 11 weeks old and weighed, on an average, 256 g. A t this time, steroids were fed to 45 of these rats. The other 45 remained on the basal diet and served as controls. Ten rats each of the control and treated rats were used for measuring ~

Flooding of the cathode flow channel is a major hindrance in achieving maximum performance from Proton Exchange Membrane Fuel Cells (PEMFC) during the scaling up process. Water accumulated between the interface region of Gas Diffusion Layer (GDL) and rib of the cathode flow field can be removed by the use of Porous Sponge Inserts (PSI) on the ribs. In the present work, the experimental investigations are carried out on PEMFC for the various reaction areas, namely 25, 50 and 100 cm2. Stoichiometry value of 2 is maintained for all experiments to avoid variations in power density obtained due to differences in fuel utilization. The experiments include two flow fields, namely Serpentine Flow Field (SFF) and Modified Serpentine with Staggered provisions of 4 mm PSI (4 mm × 2 mm × 2 mm) Flow Field (MSSFF). The peak power densities obtained on MSSFF are 0.420 W/cm2, 0.298 W/cm2 and 0.232 W/cm2 compared to SFF which yields 0.242 W/cm2, 0.213 W/cm2 and 0.171 W/cm2 for reaction areas of 25, 50 and 100 cm2 respectively. Further, the reliability of experimental results is verified for SFF and MSSFF on 25 cm2 PEMFC by using Electrochemical Impedance Spectroscopy (EIS). The use of 4 mm PSI is found to improve the performance of PEMFC through the better water management.

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