THE EFFECT OF SUPPLEMENTARY CALCIUM ON SERUM LIPIDS, LIPOPROTEINS AND APOLIPOPROTEINS IN HEALTHY ADULT WOMEN AGED 18-30 YEARS

Introduction: Several authors have noted that oral calcium treatment was associated with a change in serum Lipids and reduce the risk of cardiovascular disease. In present sutdy, we determined the effect of supplementary caicium on serum total cholesterol. TG, HOLe, LDLc, LDLcl HDLe, Apo AI, Apo B and Apo All Apo B profile in young healthy adult women.
 Methods: 53 volunteers were divided into two groups randomly, the treatment group received 1000 mg/day calcium (four doses of 625 mgs calcium carbonate) for one complete menstrual period and the control group received placebo (dextrose). Total cholesterol, TG and HDLc was determined enzymatically, Apo AI and Apo B was determined immunoturbidimetrically.
 Results: There were no correlation between any of the studied variables and calcium intake from food, calcium supplement did not change correlation coefficient of LDLc with HDLc and Apo AI with Apo B. Compared to placebo, calcium carbonate decreased serum Apo B concentration (13.7 mg/dl , p < 0.01) and incrdased Apo All Apo B (0.32 unit, P < 0.05) and TG (15.75 mg/dl, p <0.05) but the changes in other variables were not significant.
 Conclusion: These results suggest that calcium supplement increase serum TG and ApoAll Apo B but decrease Apo B. It seems that calcium supplementation may be useful for people who receive less calcium than recommended dietary allowance

On the hydrodynamics of membrane assisted fluidized bed reactors using X-ray analysis

\u3cp\u3eThe application of membrane assisted fluidized bed reactors for distributed energy production has generated considerable research interest during the past few years. It is widely accepted that, due to better heat and mass transfer characteristics inside fluidized bed reactors, the reactor efficiency can outperform other reactor configurations such as packed bed units. Although many experimental studies have been performed to demonstrate and monitor the long term performance of membrane assisted fluidized bed reactors, the hydrodynamics of membrane-assisted fluidized bed reactors has thus far only been studied in pseudo-2D geometries. In this work the solids concentration inside a real 3D fluidized bed reactor geometry was measured using a fast X-ray analysis technique. Experiments were conducted in absence and presence of two different membrane modules with different configurations and number of membranes (porous Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e tubes) for two types of particles, viz. 400–600 μm polystyrene (Geldart B type) and 80–200 μm Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e (Geldart A/B type). Results from the experiments with Geldart B type particles revealed that the membrane modules (both the membranes and the spacers) can significantly reduce bubble growth along the fluidized bed resulting in a smaller average bubble diameter, expected to improve the bubble-to-emulsion mass transfer, whereas for the experiments with fine Geldart A/B particles, and at a very high extraction values (40% of the inlet flow), a densified layer with high solids concentration was formed near the membrane, which may impose an additional mass transfer resistance for gas components to reach the surface of the membranes (concentration polarization). The results from this study help designing and optimizing the positioning of the membranes and membrane spacers for optimal performance of fluidized bed membrane reactors.\u3c/p\u3

Fluidized bed membrane reactors for ultra pure H\u3csub\u3e2\u3c/sub\u3e production - A step forward towards commercialization

\u3cp\u3eIn this research the performance of a fluidized bed membrane reactor for high temperature water gas shift and its long term stability was investigated to provide a proof-of-concept of the new system at lab scale. A demonstration unit with a capacity of 1 Nm\u3csup\u3e3\u3c/sup\u3e/h of ultra-pure H\u3csub\u3e2\u3c/sub\u3e was designed, built and operated over 900 h of continuous work. Firstly, the performance of the membranes were investigated at different inlet gas compositions and at different temperatures and H\u3csub\u3e2\u3c/sub\u3e partial pressure differences. The membranes showed very high H\u3csub\u3e2\u3c/sub\u3e fluxes (3.89 × 10\u3csup\u3e-6\u3c/sup\u3e mol·m\u3csup\u3e-2\u3c/sup\u3e· Pa\u3csup\u3e-1\u3c/sup\u3e·s\u3csup\u3e-1\u3c/sup\u3e at 400 °C and 1 atm pressure difference) with a H\u3csub\u3e2\u3c/sub\u3e/N\u3csub\u3e2\u3c/sub\u3e ideal perm-selectivity (up to 21,000 when integrating five membranes in the module) beyond the DOE 2015 targets. Monitoring the performance of the membranes and the reactor confirmed a very stable performance of the unit for continuous high temperature water gas shift under bubbling fluidization conditions. Several experiments were carried out at different temperatures, pressures and various inlet compositions to determine the optimum operating window for the reactor. The obtained results showed high hydrogen recovery factors, and very low CO concentrations at the permeate side (in average \u3c/p\u3

Palladium based membrane reactors for hydrogen production

The application of membrane reactors has been widely studied for methane steam reforming and water gas shift using Pd-alloy membranes. The integration of reaction and separation allows obtaining higher conversion degrees, smaller reactor volumes and higher efficiencies compared with conventional systems. In the last decade, much thinner dense Pd-based membranes have been produced that can be used in membrane reactors. However, the thinner the membranes the higher the flux and the higher the effect of concentration polarization in packed beds. A reactor concept that can circumvent (or at least strongly reduce) concentration polarization is the fluidized bed membrane reactor configuration, and also can improve the heat transfer. Tecnalia and TU/e are involved in four European projects that are related to development of fluidized bed membrane reactors for hydrogen production using thin Pd-Ag (<5 µm) supported membranes for different application: In DEMCAMER project a water gas shift membrane reactor was developed for high purity hydrogen production. REFORCELL aims at developing a high efficient heat and power micro-cogeneration system (m-CHP) using a methane reforming fluidized membrane reactor. The main objective of FERRET is the development of a flexible natural gas membrane reformer directly linked to the fuel processor of the micro-CHP system. FLUIDCELL aims the Proof-of-Concept of a m-CHP system for decentralized off-grid using a bioethanol reforming membrane reactor. The fluidized bed system allows operating at a virtually uniform temperature which is beneficial in terms of both membrane stability and durability and for the reaction selectivity and yield. The main results obtained in these projects in terms of performance of the membranes and the membrane reactors will presented in this work