65 research outputs found

    Where is the best site for embryo transfer? A study of relation of embryo-fundal distance with pregnancy rate in ICSI-ET cycle

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    Background: Embryo transfer is the ultimate and most critical step of IVF-ICSI treatment cycle. It has a significant impact on the success rate of IVF cycle. Undoubtedly, it has significant impact of the pregnancy rate and implantation rate. Along with the other factors the impact of the site of embryo transfer has also been studied by several investigators. There is lack of clear consensus about the ideal site of embryo transfer.Methods: This study includes a retrospective analysis of 200 embryo transfers done in 200 infertile couples done at our infertility clinics from January 2016 to March 2016. Transfer cycles of gamete donation, embryo donation and frozen embryos were excluded from the study. The study involved patients undergoing their first IVF- ICSI cycle with fresh embryo transfer at our IVF Unit. All patients were stimulated using Antagonist protocol starting Gonadotropins from day 2/3 of menses.Results: The clinical pregnancy rate was highest (55.2%) in group 2 when the embryo fundal distance was more than 10 mm but less than or equal to 15 mm. In group 3 when embryos were placed beyond 15 mm distance from the fundus, the clinical pregnancy rate was 34.66%. The lowest pregnancy rate - 30% was found in group 1 when embryos were places less than 10 mm from fundus. There was only a single case of ectopic pregnancy in the study group. The ectopic pregnancy was seen in group 1. There two cases of abortion each in group 2. The miscarriage rate was higher in group 3-5. 33% as compared to 1.9% in group 2. The sample size was small to determine if these results were significant enough.Conclusions: The present study demonstrates that higher pregnancy rates are obtained if the embryos are selectively placed at a distance between 10mm to 15 mm from the fundal endometrial surface. It is not possible to determine exact location of embryo placed in utero by any method. The findings of our study can be considered as a guiding force by clinicians

    Microwave Hydrothermal Carbonization of Rice Straw: Optimization of Process Parameters and Upgrading of Chemical, Fuel, Structural and Thermal Properties.

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    The process parameters of microwave-induced hydrothermal carbonization (MIHTC) play an important role on the hydrothermal chars (hydrochar) yield. The effect of reaction temperature, reaction time, particle size and biomass to water ratio was optimized for hydrochar yield by modeling using the central composite design (CCD). Further, the rice straw and hydrochar at optimum conditions have been characterized for energy, chemical, structural and thermal properties. The optimum condition for hydrochar synthesis was found to be at a 180 °C reaction temperature, a 20 min reaction time, a 1:15 weight per volume (w/v) biomass to water ratio and a 3 mm particle size, yielding 57.9% of hydrochar. The higher heating value (HHV), carbon content and fixed carbon values increased from 12.3 MJ/kg, 37.19% and 14.37% for rice straw to 17.6 MJ/kg, 48.8% and 35.4% for hydrochar. The porosity, crystallinity and thermal stability of the hydrochar were improved remarkably compared to rice straw after MIHTC. Two characteristic peaks from XRD were observed at 2? of 15° and 26°, whereas DTG peaks were observed at 50?150 °C and 300?350 °C for both the materials. Based on the results, it can be suggested that the hydrochar could be potentially used for adsorption, carbon sequestration, energy and agriculture applications

    A review of catalytic hydrogen production processes from biomass

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    Hydrogen is believed to be critical for the energy and environmental sustainability. Hydrogen is a clean energy carrier which can be used for transportation and stationary power generation. However, hydrogen is not readily available in sufficient quantities and the production cost is still high for transportation purpose. The technical challenges to achieve a stable hydrogen economy include improving process efficiencies, lowering the cost of production and harnessing renewable sources for hydrogen production. Lignocellulosic biomass is one of the most abundant forms of renewable resource available. Currently there are not many commercial technologies able to produce hydrogen from biomass. This review focuses on the available technologies and recent developments in biomass conversion to hydrogen. Hydrogen production from biomass is discussed as a two stage process – in the first stage raw biomass is converted to hydrogen substrate in either gas, liquid or solid phase. In the second stage these substrates are catalytically converted to hydrogen. © 2009 Elsevier Ltd. All rights reserved

    Nanostructured catalysts for hydrogen production by liquid phase reforming of sugarcane solutions

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    Sugarcane is an ideal source of hydrogen in Australia. The influence of several reaction parameters on hydrogen production using reforming of aqueous sugar solution over innovative Pt, Pd, and Ni nanometals supported on mesoporous metal oxides at 185°-250°C under high pressure was studied. Bimetallic catalysts, e.g., Pt-Ni, Pt-Pd, and Pd-Ni had higher activity for the production of hydrogen using aqueous solutions of sugars and ethylene glycol compared with the monometallic catalysts. The catalyst support also affected the selectivity for hydrogen production with hydrogen selectivity decreasing in the order γ-Al O > ZrO > CeAl. The rate of formation of hydrogen varied for different sugars in the order sucrose > fructose > glucose > ethylene glycol and it also increased as temperature increased from 185°-220°C. A good catalyst for production of H by liquid-phase reforming must facilitate C-C bond cleavage and promote removal of adsorbed CO species by the water-gas shift reaction, but the catalyst must not facilitate C-O bond cleavage and hydrogenation of CO or CO . This is an abstract of a paper presented at the 18th International Congress of Chemical Process Engineering (Praque, Czech Republic 8/24-28/2008)
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