Life cycle assessment of advanced zero emission combined cycle power plants

This study investigated different concepts for natural-gas-fired power plants with the CO[2] capture, and compared them based on the net plant efficiency and emission of CO[2]. The cycles were based on a six oxy-fuel, one post-combustion and two pre-combustion capture concept. This paper presented the results of an environmental evaluation performed by the application of the Life Cycle Analysis [LCA] method using SimaPro model to compare an Advanced Zero Emission Power Plant [AZEP] concept with a conventional combined cycle power plant from 50MW to 400MW. The LCA study was built upon the calculation and the comparison of several impacts [emissions of CO[2], CO, NO[X], and SO[X], consumption of water and primary energy] and several impact categories [climate change, acid rain, ozone depletion and Ecotoxicity]. The work was developed entirely using the Eco-indicator99 of the LCA method. The results showed that for all studied impacts, the AZEP power plants have fewer impacts. However, compared to the conventional combined cycle power plants, the total primary energy consumption in the AZEP concept is bigger due to the lower electric efficiency

[Effect of hydrostatic pressure on in vitro maturation of mouse oocytes]

Examining of the effect of hydrostatic pressure on in vitro maturation of mouse oocytes. Female NMRI mice 6-8-week-old was selected. Antral follicles with diameter of 500 micro m were isolated from ovaries. Then follicles were divided into control and experiment groups. In experiment group, follicles were transferred to pressure chamber and subjected to 20 mm pressure for 30 min. Follicles without pressure exposure used as control. Each follicle cultured individually in 100 micro l alpha-MEM supplemented with 5% FBS, 100 mlU/ml rFSH, 10 ng/ml rEGF and 7.5 lU/ml HCG for in vitro maturation, under mineral oil. Follicles from two groups were cultured for 48 h and evaluated in vitro maturation of oocyte by the percentage of oocytes in GV, GVBD and MIL Viability of oocytes and cumulus cells was assessed with nuclear vital staining [propidium iodide and bisbensamide]. The results showed that, exposure to hydrostatic pressure improved the oocyte in vitro maturation. After 24 h the percentage of GVBD and metaphase [MII] oocytes increased in hydrostatic pressure treated follicles compared to control [P<0.05]. After 48 h, the percentage of metaphase [MII] oocytes increased in hydrostatic pressure treated follicles compared to control [P<0.05]. Furthermore, a significant increase in the cumulus cells was observed [P<0.05]. Hydrostatic pressure had no effect on oocyte viability. It seems that hydrostatic pressure can be a cell death inducer in cumulus cells. Hydrostatic pressure may play a role in oocyte maturation and fertilization by improving in releasing and mediating signals to oocyte by increasing cell death in cumulus cells