فهرست مطالب سیامک علی پور

The current study aims to investigate the microstructural and dielectric properties of the composite based on Polyvinyl alcohol-CaCu3Ti4O12 (CCTO-PVA) containing 0, 10, 30, and 70 wt % ceramic phase as the dielectric promoter. To this end, CCTO particles were first prepared by calcination of CuO, TiO2, and CaCO3 mixture at 1000 °C to fabricate the composite. Then, solutions with adequate amounts of PVA in water were provided, and the CCTO was added to solutions considering the composite weight percentage. Finally, the mixtures were dried at 60 °C. The X-Ray Diffraction (XRD) results of the powder indicated that upon increasing the amount of CCTO considerably, the semi-crystal peak height of the PVA would decrease. In addition, according to Scanning Electron Microscopy (SEM), the CCTO particles were dispersed preferably well in the polymeric phase. Dielectric properties were measured at 1 KHz, and the findings revealed that the dielectric constant and dissipation factors of the CCTO were measured as 1360 and 0.04, respectively. Moreover, these parameters of the PVA were obtained as 4 and 0.15, respectively. Increasing the CCTO weight percent of composites from zero to 70 % would increase the dielectric constant from 4 to 68 and reduce the dissipation factor from 0.17 to 0.04. The comparison of the dielectric constants with the results from different models indicated that the composite behavior was in good agreement with the logarithm model output.

Levulinic acid (LA) has been reported as an important building block in the road map of converting biomass to value added compounds. Since LA is a versatile molecule, techno-economic analysis of its production from C-6 monosaccharides has been investigated. In this study, the process of glucose and fructose conversion to LA was designed in an aqueous solution in presence of HCl as the homogeneous acid catalyst based on published data. In order to perform the economic analysis, parameters were considered as feed mass flow rate 300 tons/day, working days per year 330, plant lifetime of 20 years, and 10% internal interest rate. Based on economic evaluations, the minimum selling price (MSP) of LA produced from fructose and glucose were 1.457 and 1.628 $/Kg, respectively. Sensitivity analysis was conducted to investigate different parameters impacts on MSP. Results indicate that feed price and product yield are major affecting parameters.

Foot-and-Mouth (FMD) is a viral and contagious disease that endangers both domestic and wild animals and this disease has caused a lot of social and economic damage to the livestock industry in Iran. Considering the endemism of this disease in Iran, the main purpose of this study is to investigate the temporal trend, discover spatial and spatio-temporal clusters and determine the impact of environmental factors and model the disease in order to better understand the spatio-temporal epidemiology of FMD in Iran. In this study, data related to the incidence of disease as well as environmental variables including meteorological variables, vegetation and topography of the region were used. This study was performed on 12442 cases of registered diseases in the years 1396-1387 in the city for the whole of Iran. First, general auto correlation indices including Moranchr('39')I index, General G index and Ripleychr('39')s K index were used to investigate the distribution of the spatial pattern of the disease. Local Moran and the Gatis-Ord G* index were used to detect hot and cold spots. Then, with the help of the points of occurrence and time of the disease, spatial and spatio-temporal clusters of the disease were discovered. Spearmanchr('39')s correlation and linear regression analysis were used to evaluate the type and severity of correlation between environmental parameters and disease incidence. The results showed that the maximum incidence is in spring (44%) and the minimum incidence is in summer (15%). The months of Ordibehesht, Farvardin, Khordad and Dey, with a total of 6650 cases, were the most riskful months of the year, respectively. Autocorrelation tests showed the distribution of FMD clusters for every 10 years studied. The results of the local Moran index and the Gatis-Ord G* showed that the foci of this disease are still active in Iran and parts of Semnan, Tehran, Markazi, Fars, Lorestan, Khorasan Razavi and East Azerbaijan provinces are hot spots of FMD. In spatial scan, 8 clusters were identified, which confirmed the results of Moran and the Gatis-Ord G* index. In the spatio-temporal scan, 5 clusters were discovered that were consistent with the results of the spatial scan. Spearman analysis showed that there is a positive correlation between the incidence of the disease and vegetation, which is decreasing from the beginning to the end of the year and has a negative relationship in winter. Also, a positive and increasing correlation was observed with wind speed and precipitation from the beginning to the end of the year. In addition, a positive correlation between the incidence of the disease and altitude and a negative relationship with the direction of the slope was calculated. Linear regression analysis was also used to evaluate the effect of variables, which resulted in confirming Spearman correlation outputs. The results of the model showed that vegetation and topography are the most important environmental factors that affect the prevalence of snow fever in the region. The results of this study identify areas that are at higher risk and need more planning and attention to control the disease.