Introduction: Endometrial polyps destroy the endometrial texture and play an important role in the implantation failure and miscarriage. There is no consensus about the management of patients diagnosed with endometrial polyp in IVF cycles. The purpose of this study was to do a hysteroscopic polypectomy during stimulation period in the ART cycle.Materials and Methods: In this study, nine patients who underwent ART cycles were diagnosed to have endometrial polyps less than 1.5 cm by transvaginal ultrasonography. Eight patients were treated by GnRH Agonist long protocol and one patient was the recipient of the egg donation cycle. In All patients, polyp resection was performed through hysteroscopic polypectomy under general anesthesia after obtaining the informed consent. Polypectomy was done during ovarian stimulation in ART cycle, along with hormone replacement therapy in the recipient of egg donation cycle. The interval between polyp resection and embryo transfer was two to sixteen days.Results: As a result, four patients achieved pregnancy (two twins, two singletons), four patients were unsuccessful, and one pregnancy was terminated because of a blighted ovum. All of the successful pregnancies are still ongoing.Conclusion: There is a dilemma regarding the management of patients diagnosed with endometrial polyp in an ART cycle. If polypectomy before embryo transfer in the same IVF cycle is proven to be safe, then embryo transfer without canceling the cycle would be done. This study has been done in nine patients; However further studies with more patients are required to confirm these findings.

This study investigated different concepts for natural-gas-fired power plants with the CO2 capture, and compared them based on the net plant efficiency and emission of CO2. 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 CO2, CO, NOX, and SOX, 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.

A thermodynamic model for an open inverse Brayton cycle (refrigeration or heat pump cycle) with pressure drop irreversibilities is established. There are seven flow resistances (or pressure drops) encountered by the working fluid stream for the inverse Brayton cycle. Two of these, the friction through the blades and vanes of the compressor and the expander, are related to the isentropic efficiencies. The remaining flow resistances are always present because of the changes in flow cross-section at the compressor inlet and outlet, heat exchanger inlets and outlets and expander inlet and outlet. The analytical formulae about the cooling load of refrigeration cycle, the heating load of heat pump cycle and other coefficients are derived, which indicate that the thermodynamic performance for open inverse Brayton cycle can be optimized by adjusting the mass flow rate (or the distribution of pressure losses along the flow path). It is shown that there are optimal air mass flow rates (or the distribution of pressure losses along the flow path) which maximize the cooling load of refrigeration cycle, and the optimal air mass flow rates are smaller than the one at the maximum power output of the direct Brayton cycle.

Background: Life-cycle assessment (LCA) is a comprehensive method used to evaluate the environmental effects throughout the entire lifespan (from creation to disposal) of a product or process. In this study, we conducted an analysis of the environmental impact associated with generating 1 kilowatt-hour of electricity in a combined-cycle power plant located in the southwest region of Iran.Methods: An LCA following ISO 14044 standards was conducted via the ReCiPe method evaluating 10 impact categories at the midpoint level, and covering the entire life cycle. This method was selected for its comprehensive modeling of potential impacts from numerous chemicals and its practicality at both midpoint and endpoint levels.Results: The study found that resource availability (RA) has the highest impact at 53% in endpoint categories, mainly due to natural land transformation (NLT) and fuel depletion (FD). Human health (HH) contributes 43%, while ecosystem diversity (ED) has a minor 4% role. In midpoint categories, over 99% of global warming potential (GWP) and climate change (CC) are from CO2 emissions due to fossil fuel combustion.Conclusion: Midpoint analysis identified NLT, FD, CC, freshwater ecotoxicity, terrestrial ecotoxicity, human toxicity, photochemical oxidant formation, terrestrial acidification, freshwater eutrophication, and water depletion as the most impacted categories by the power plant. However, at the endpoint level, RA, HH, and ED were the primary concerns. Fossil fuel use significantly shaped the environmental impact throughout the power plant’s life cycle.