Comparative evaluation of sizing of metal hydride (MH) hydrogen storage tank filled with different alloys

This study presents a comparative analysis of sizing of metal hydride tank filled with different alloys. Alloys include solid solutions and intermetallic compounds of the generic families AB₅, AB₂, AB, A₂B. The effects of the different alloys on the sizing of metal hydride hydrogen storage tanks are complicated and depend on many factors. In this paper, a thermoeconomic optimization analysis with a simple algebraic formula was presented for the estimation of optimum metal hydride tank surface area for heat transfer enhancement. The optimum area of the metal hydride tank filled with commercially available different alloys (LaN₅, Ti_0,98Zr_0,02V_0,43Fe_0,09Cr_0,05Mn_1,5, TiFe, Mg₂NiH₄) was evaluated and compared by the developed method. The optimum net savings and the value of payback were determined for four alloys. It is found that mathematical model can be employed for the determination of optimum metal hydride tank design and increasing net savings according to alloy types. The optimum areas of the tanks filled with four alloys (LaN₅, Ti_0,98Zr_0,02V_0,43Fe_0,09Cr_0,05Mn_1,5, TiFe, Mg₂NiH₄) were calculated as 0.136, 0.130, 0.133, and 0.173 m², respectively. The optimum net savings for tanks filled with four alloys (LaN₅, Ti_0,98Zr_0,02V_0,43Fe_0,09Cr_0,05Mn_1,5, TiFe, Mg₂NiH₄) are about 461.0, 409.3, 419.6, and 979.6 $ and the values of payback are about 1.98, 2.1, 2.17, and 1.37 years, respectively. Excessive area of the metal hydride tank would not be as economical as the optimum tank area. Thermal management of metal hydride tank must be designed for optimum points calculated at which maximum savings occur.     

Cytogenetic monitoring of domestic mammals exposed to wastewaters from the localities of Dladla and Boukallou near Settat, Morocco

The aim of this work was to know the biological impact of wastewaters on livestock in the localities of Dladla and Boukallou (Town of Settat, Morocco), where wastewaters are largely used by the local population for their agricultural activities. We used the micronucleus (MN) test in cytochalasin B blocked binucleated cells (BNC) to assess the possible induced genetic effects. The cellular proliferation index (PI) was also calculated. Blood samples were collected from sheep, bovines and mules and peripheral blood cultures were made according to our laboratories' standard methodology. The results showed a significant increase of micronucleated cells in the lymphocytes of the exposed animals (14+/-8.79 MN/500 BNC) compared to the control (3+/-1.54 MN/500 BNC). The PI showed a nonsignificant decrease in the exposed animals. The highest MN frequency was found in mules which is probably due to their more sedentary life. Direct use of the wastewater by the animals as their source of drinking water significantly increased the frequency of cells with micronuclei. We also established an inverse correlation between the chromosome number and the PI. These results suggest a serious degradation of the ecosystem due to the wastewaters with a direct impact on its inhabitants.