Effect of Sintering Atmosphere on Phase Evolution of Hydroxyapatite Nanocomposite Powders

In the present work, pure hydroxyapatite, hydroxyapatite-20 wt% alumina and hydroxyapatite-20 wt% titanium mixtures were pressed and sintered in air, moist, and reduction atmospheres at 1200 C for 2 h. XRD investigations of sintered samples showed that, pure hydroxyapatite is stable in all three atmospheres. But, moist and reduction atmospheres were preferred to suppress the hydroxyapatite decomposition in hydroxyapatite -alumina and hydroxyapatite – titanium nanocomposites, respectively. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3494

The use of artificial neural network to evaluate the effects of human and physiographic factors on forest stock volume

Increase in human factors coupled with physiographic factors will impact stock volume in forest ecosystems. The scale of this process and critical information in forestry management provide an incentive for the development of model to predict the forest stock volume. In this paper, we use data derived from Siahrood, Guilan Province, Iran using Field inventory by cluster sampling in a network (1 × 1 km) with 90 clusters and 900 circular plots (1000 m2). To evaluate modeling approaches for stock volume responses to changing condition. The relationship between the standing volume and human factors and each physiographic factor were examined using Pearson and the Artificial Neural Network method. Based on Field  observations it was observed that  different stock volume exhibit in specific  physiographic response to population density, livestock density, distance from village, aspect, slope and elevation. Results show that Multilayer Neural Networks with 12 nodes can predict the forest stock volume with the lowest RMSE (48.76m3). In addition, the artificial neural network designed for the buffer of three populations with 85.5%  accuracy was selected as the best model to predict the volume based on the mentioned components. The results suggest ANN is an effective approach to predict exact forest stock volume and human factors in certain topography conditions and provides  useful information for the acceptable amount of standing inventory using the present human population in future experiment.Keywords: stock volume, human factors, physiographic factors, neural network Corresponding autho

Influence of zinc incorporation on microstructure of hydroxyapatite to characterize the effect of pH and calcination temperatures

AbstractThis work was focused to study the existence of Zn2+ in structure, chemical composition as well as particle and crystallite size of hydroxyapatite (HAp) to characterize the effect of pH of the solution and calcination temperature. Non-stoichiometric HAp (nHAp) powders containing 4at.% zinc fraction were synthesized via solution–precipitation method. In order to characterize the effect of pH (values: 9 and 10.5) and two calcination temperatures (550 and 1000°C) on chemical composition, molecule internal bonds, particle and crystallite size of the synthesized powders, XRD, EDS, FTIR and SEM techniques were utilized. The results showed that zinc cations could be incorporated in the HAp atomic structure to form low crystalline single phase of nHAP. The pH adjustment to 10.5 caused the formation of powders with smaller particle and crystallite sizes. The results also indicated that calcination temperature up to 1000°C caused decomposition of zinc doped nHAp to β-tri calcium phosphate and tri zinc calcium phosphate phases which are used to control the speed of biodegradation

Prevalence of chronic kidney disease and its associated risk factors: The first report from Iran using both microalbuminuria and urine sediment

Background: The incidence of major risk factors of chronic kidney disease (CKD) in the world is on the rise, and it is expected that this incidence and prevalence, particularly in developing countries, will continue to increase. Using data on urinary sediment and microalbuminuria, we aimed to estimate the prevalence of CKD in northeast Iran. Methods: In a cross-sectional study, the prevalence of CKD in a sample of 1557 regionally representative people, aged � 18 years, was analyzed. CKD was determined based on glomerular filtration rate (GFR) and microalbuminuria. Life style data, urine and blood samples were collected. Urine samples without any proteinuria in the initial dipstick test were checked for qualitative microalbuminuria. If the latter was positive, quantitative microalbuminuria was evaluated. Results: 1557 subjects with a mean age of 56.76 ± 12.04 years were enrolled in this study. Based on the modifcation of diet in renal disease (MDRD) equation, 137 subjects (8.89%) were categorized as CKD stages III-V. Based on urine abnormalities, the prevalence of combined CKD stages I and II was 10.63%, and based on macro- and microalbuminuria it was 14.53%. The prevalence of CKD was significantly associated with sex, age, marital status, education, diabetes mellitus (DM), hypertension (HTN), ischemic heart disease (IHD), waist to hip ratio, myocardial infarction (MI), and cerebrovascular accident (CVA). Conclusion: CKD and its main risk factors are common and represent a definite health threat in this region of Iran. Using and standardizing less expensive screening tests in low resource countries could be a good alternative that may improve the outcome through early detection of CKD

Optimal Operation of Micro-grids Considering the Uncertainties of Demand and Renewable Energy Resources Generation

Nowadays, due to technical and economic reasons, the distributed generation (DG) units are widely connected to the low and medium voltage network and created a new structure called micro-grid. Renewable energies (especially wind and solar) based DGs are one of the most important generations units among DG units. Because of stochastic behavior of these resources, the optimum and safe management and operation of micro-grids has become one of the research priorities for researchers. So, in this study, the optimal operation of a typical micro-grid is investigated in order to maximize the penetration of renewable energy sources with the lowest operation cost with respect to the limitations for the load supply and the distributed generation resources. The understudy micro-grid consists of diesel generator, battery, wind turbines and photovoltaic panels. The objective function comprises of fuel cost, start-up cost, spinning reserve cost, power purchasing cost from the upstream grid and the sales revenue of the power to the upstream grid. In this paper, the uncertainties of demand, wind speed and solar radiation are considered and the optimization will be made by using the GAMS software and mixed integer planning method (MIP).Article History: Received May 21, 2016; Received in revised form July 11, 2016; Accepted October 15, 2016; Available onlineHow to Cite This Article: Jasemi, M., Adabi, F., Mozafari, B., and Salahi, S. (2016) Optimal Operation of Micro-grids Considering the Uncertainties of Demand and Renewable Energy Resources Generation, Int. Journal of Renewable Energy Development, 5(3),233-248.http://dx.doi.org/10.14710/ijred.5.3.233-24

A case report of Enteritis Redmouth Disease in cultured rainbow trout (Oncorhynchus mykiss) in Kohkyloyeh va Boyerahmad Province in Iran

An unknown mortality was occurred in some ponds of a farm in an area of Kohgiloyeh-&- Boyerahmad province. Three ponds showed the highest mortality rate, about 5 to 20 dead fish were reported daily for 45 days. Afflicted fish have darkening in the skin and swimming near surface or at the floor of pond and swam unmatched with flock. Some fish showed hemorrhages around and within the oral cavity and exophthalmia occasionally. About 45 moribund rainbow trout were sampled for dissection and bacteriological examination. Kidney, liver and spleen of the fishes were examined for the detection and identification of bacteria causative agent of disease in rainbow trout. They cultivated aseptically on different media (Blood Agar, Tryptic soy Agar, TCBS Agar and MacConkey Agar). All fish have been infected and suffered septicemia. A type of gram's negative bacteria was responsible of infection and mix infection was not confirmed. The bacterium was being able to grow on Mac Conkey agar. It was a bacterium very similar with Yersinia ruckeri which induced infection. Detection was based on clinical finding and bacteriological laboratory results so using of some confirmation methods such as FAT or PCR would be recommended strongly

A pilot double-blind randomised placebo-controlled trial of the effects of fixed-dose combination therapy ('polypill') on cardiovascular risk factors

SummaryAim: Our objective was to investigate the effects and tolerability of fixed-dose combination therapy on blood pressure and LDL in adults without elevated blood pressure or lipid levels. Methods: This was a double-blind randomised placebo-controlled trial in residents of Kalaleh, Golestan, Iran. Following an 8-week placebo run-in period, 475 participants, aged 50 to 79 years, without cardiovascular disease, hypertension or hyperlipidaemia were randomised to fixed-dose combination therapy with aspirin 81 mg, enalapril 2.5 mg, atorvastatin 20 mg and hydrochlorothiazide 12.5 mg (polypill) or placebo for a period of 12 months. The primary outcomes were changes in LDL-cholesterol, systolic and diastolic blood pressure and adverse reactions. Analysis was by intention-to-treat basis. Results: At baseline, there were differences in systolic blood pressure (6 mmHg). Taking account of baseline differences, at 12 months, polypill was associated with statistically significant reductions in blood pressure (4.5/1.6 mmHg) and LDL-cholesterol (0.46 mmol/l). The study drug was well tolerated, but resulted in the modest reductions in blood pressure and lipid levels. Conclusion: The effects of the polypill on blood pressure and lipid levels were less than anticipated, raising questions about the reliability of the reported compliance. There is a case for a fully powered trial of a polypill for the prevention of cardiovascular disease. © 2010 Blackwell Publishing Ltd