In this study, the heat transfer coefficient of the pool boiling is evaluated in the nuclear region for the fluid at different concentrations of water-ethanol solution on a horizontal cylinder at 1 atm. For this purpose is examined the diameter of the growing bubble of water-ethanol solution in a heat flux range of 1 to 60 kW.m-2 in different concentrations on the horizontal cylinder of stainless steel. The results show that by an increase in heat flux, bubble diameter increases. The diameter of the bubbles created in heat flux is examined and compared with different dynamic models that according to the calculated average error of the model. Hamzehkhani model has better consistency with the experimental data. Recently, optimization methods have been widely used in fuzzy equilibrium calculations. Among these methods, genetic algorithms can be used to calculate the binary interaction components of activity coefficient patterns in equilibrium systems. The equations and relations of previous for the solution have a high error in predicting the heat transfer coefficient, so using the obtained data and applying the genetic algorithm. A newer experimental equation is presented which has a good fitting with the experimental data.

Oxidative stress has been implicated in the pathogenesis of many diseases, while multiple drug resistance constitutes a major problem in management of infectious diseases. The aforementioned problems necessitate continuous investigations for development of novel antioxidant and antimicrobial agents. Here, phytochemical constituents, antioxidant, and antimicrobial activities of n-hexane, ethyl-acetate, 70%-ethanol and methanol extracts of Parquetina nigrescens leaves were investigated. Antioxidant activities were evaluated by total phenolic content, total flavonoid content, total antioxidant capacity, reducing power, DPPH, nitric oxide, and lipid peroxidation assays. Antibacterial (Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli) and antifungal (Aspergillus niger, Aspergillus flavus, Candida albican and Penicillium spp.) activities of the extracts were examined using agar well diffusion method. Phytochemical investigations revealed presence of various phytochemicals, including alkaloids, tannins, flavonoids, cardiac glycosides, and terpenoids. Total phenolic contents were in the range 0.321±0.030–0.432±0.030 mg gallic acid/g extract, while total flavonoid contents were in the range 0.020±0.003–0.064±0.006 mg quercetin/g extract. The extracts displayed moderate total antioxidant capacity (TAC) and ferric reducing power; having TAC values in the range 0.820±0.060–0.876±0.030 mg ascorbic acid/g extract and reducing powers in the range 0.01–0.68. The extracts showed moderate to high activities against DPPH radical, nitric oxide and lipid peroxidation; having IC50 values in the range 59.3±10.8–87. 1±14.2 µg/mL, 52.7±10.6–56.9±10.1 µg/mL, and 58.9±18.6–101.3±10.2 µg/mL, respectively. Furthermore, ethyl-acetate extract showed broad spectrum antibacterial activities, while n-hexane extract demonstrated narrow spectrum antifungal activity. These findings suggest that P. nigrescens leaves have potentials as source of antioxidant and antimicrobial agents.

Nickel oxide nanoparticles were prepared using solid-state thermal decomposition of NiCl2 at the presence of maleic acid at 600°C, characterized by FT-IR spectroscopy, XRD, FE-SEM, and applied as a new adsorbent for the removal of methyl green (MG) from aqueous solution. FT-IR and XRD results confirmed the preparation of cubic NiO nanoparticles. SEM image showed that NiO nanoparticles have a wide size distribution from 50 to 200 nm. The pH of the solution, adsorbent dosage, and contact time effect on MG removal efficiency were considered. The uptake of MG was determined to be >96% in 60 min and adsorbent dosage of 0.02 g

Adsorption process has been widely used as one of the efficient methods in removing pollutants that are hardly biodegradable. In this study, new epichlohydrine crosslinked Schiff base chitosan/Fe2O3 nanocomposite was prepared and applied as adsorbent material. The synthesized adsorbent was characterized by FT-IR, XRD, TGA/DTA, DSC, EDS, BET, XRD and FE-SEM to explore morphology, structure and functional groups. The adsorbent was applied for removal of methyl green (MG) from aqueous solutions through batch experiments. Different parameters such as adsorbent dosage, pH and contact time were considered. The removal efficiency of 94.8 % was acquired at the optimum condition of pH = 8, adsorbent dosage of 0.02 g and contact time of 30 min. The adsorption capacity of the sorbent was found to be 47.4 mg/g. This nanocomposite could be a suitable candidate for the removal of other organic dyes.

Epoxides are molecules with extensive usages in various products synthesis. They are capable of reacting with different nucleophiles and their potential in the ring-opening of epoxides adds to their importance as pioneers in the synthesis of organic compounds. In the present research, a green and easy method for the synthesis of zinc oxide nanoparticles as a catalyst has been expressed. Synthesized zinc oxide nanoparticles were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The UV-Vis spectrum of the nanoparticles showed an absorption peak at 327 nm corresponding to the ZnO nanoparticles. X-ray diffraction analysis also showed a high degree of crystallinity of the synthesized nanoparticles with the hexagonal structure. Zinc oxide nanoparticles were studied as an effective catalyst for epoxide ring-opening. The reactions were done by aliphatic and aromatic amines and alcohols as a nucleophile at room temperature and under microwave conditions. The results of the reactions show that the presence of zinc oxide nanoparticles catalyzes the ring-opening of the epoxides well. The ZnO nanocatalyst leads to the synthesis of products with high efficiency and good regioselectivity in a short period of time.

Refrigerant fluids are widely used to reduce temperature in heat transfer systems and study of the thermal conductivity of these fluids is of great importance in design of heat transformers, pumps and refrigeration cycles. The main goal of this work is intended to serve as the assessment of corresponding states correlation of thermal conductivity in terms of pair interaction potential energy for R125, R134a, R12, R14 and R141b refrigerants, considering the anisotropy of potential interactions. In order to present a concise theoretical model for calculation of thermal conductivity, we first applied the extended Chapman-Enskog formalism and calculated the collision integrals and thermal conductivity values for R125, R134a, R12, R14 and R141b dilute fluids and subsequently, made a comparison between the computed results and the most accurate available experimental data. In this respect, the efficiency of intermolecular potential parameters to reproduce thermal conductivity values ??of R125, R134a, R12, R14 and R141b refrigerants was assessed. In the next step, the effect of non-spherical potential energy functions and the contribution of internal degrees of freedom for the thermal conductivity of the mentioned refrigerants fluids have been formulated and led to more accurate computational results. Finally, we have shown that the present theoretical model provide a good overall account of the experimental thermal conductivity of these compounds, considering the stated uncertainty in the measurements.

Introduction: The various parts of Citrus sinensis plant have been employed over the years for medicinal purposes. As part of the concept of waste to wealth, the medicinal importance of the peels was exploited. This study aimed at determining the antioxidant and in vitro antidiabetic activities of fermented peel extracts of C. sinensis.Method: Fermentation of the peels was carried out, and phytochemical tests were done. DPPH free radical scavenging activity, anti-lipid peroxidation and Antidiabetic assay method were performed in vitro using standard procedures.Results: C. sinensis were rich in polyphenols and reducing sugars. Radical scavenging assay showed an IC50 of 0.57µg/ml and 1.60µg/ml for fresh peels and dried peels respectively for DPPH assay, and 0.67µg/ml (fresh) and 0.72µg/ml (dried) for anti-lipid peroxidation assay. The a-amylase inhibition assay showed that the fermented fresh peels and fermented dried peels had IC50 values of 2.23µg/ml and 2.73µg/ml respectively. The a-glucosidase assay showed better inhibition by the extracts. Fermented fresh and dried peels had IC50 values of 0.03µg/ml and 0.03µg/ml respectively.Conclusion: Fermented fresh peels of C. sinensis expressed relatively stronger protection in the antioxidant and antidiabetic assays than the fermented dried peels. This study revealed that extracts can be considered as an important addition to the therapeutic management for diabetes.