فهرست مطالب صدیقه سلطانی

People's participation in the management of urban affairs guarantees the realization of good and worthy urban governance. In urban management, the principle of participation at all levels of decision-making is considered essential. Participation as the most basic element in achieving development goals, especially urban development, is of particular importance. In this study, a comparative evaluation of citizens' participation in urban management in the planned neighborhood of Etemadiyeh and the neighborhood of informal wireless housing in the City of Zanjan has been conducted. The present study is applied in terms of purpose and descriptive-analytical (survey) and comparative in terms of method. The collected data were analyzed in two parts- descriptive statistics and inferential statistics- using SPSS software. The results showed that there was a positive and significant relationship among all the features and factors of citizen participation in urban management (citizen participation in urban affairs, cooperation with the municipality and other urban management institutions, citizen participation in civic activities, citizen participation in urban management, status of payment of economic and revenue expenses of the city, status of criticism and presence of urban management performance, status of cooperation and participation in preparing urban plans, participation in voluntary activities in the field of urban management, urban management in the field of citizen participation based on type of participation) on one hand and good and decent urban governance on the other hand. Also, the results of the study showed that there is a significant difference between citizens' participation in planned and prosperous neighborhoods in the city and informal and deprived neighborhoods, and these neighborhoods differed in their participation in urban management.

Carboxy methyl cellulose is a water-soluble polymer that is used in various industries. There are various sources for carboxy methyl cellulose one of them is bagasse. Sugarcane bagasse is composed of cellulose, hemicellulose, and lignin. Since 30-40% of this fibrous residue contains cellulose, it can be used as a source of cellulose for the preparation of carboxymethyl cellulose. In this project hemicellulose and lignin were separated from bagasse by diluted acid and sodium hydroxide solution and cellulose were extracted. The results showed that dilute sulfuric acid removed more hemicellulose than dilute nitric acid in the acid treatment stage. In order to separate cellulose completely, various concentrations of sulfuric acid and sodium hydroxide were used at different reaction times. The normalized areas under the characteristic peaks of FT-IR spectra of the samples were calculated by Origin software and the sample with the highest yield of extracted cellulose was selected. In the next stage, the extracted cellulose was used to prepare carboxymethyl cellulose. Response Surface Methodology (RSM) with Box-Behnken Design (BBD), was used to achieve the highest degree of substitution of carboxymethyl cellulose. The independent variables were reaction temperature, the concentration of sodium hydroxide solution, and the amount of sodium mono-chloroacetate per gram of cellulose. The highest degree of substitution was 0.66 while the calculated satisfaction factor was 97.14 percent, which shows good correspondence with the experimental data. Viscosity and molecular weight for the solution of 2% carboxymethyl cellulose in water with 0.66 degrees of substitution were 24.8 cp and 261000 grams per mole respectively which has been used in detergent materials.

This study investigates monetary and financial shocks on macroeconomic variables, focusing on the role of banking intervention. For this purpose, a Keynesian dynamic stochastic general equilibrium (DSGE) model is designed for Iran’s economy that involves financial and banking sectors. The results of the model simulation show that the financial accelerator theory works in the Iranian economy. Also, the intermediary role is confirmed by the impulse response function. In other words, economic policies can impress on macroeconomic indicators more when banks intervene in the economy. Therefore, to control the effects of economic shocks on banks' performance, it has been suggested that monetary policymakers pay attention to the important roles of financial markets in the transfer mechanism and monetary policy intensity. On the other hand, because of mandatory rules of interest rates determination, banks have to establish a commission and nonprofit services instead of sharing income to decrease the effect of economic shocks.

Hypothesis: Short fibers can be incorporated directly into the rubber compound along with other nanoparticles. The state of filler dispersion and orientation in the matrix, their size and aspect ratio as well as the interactions with the rubber chains have been shown to be crucial parameters that determine the reinforcing ability of these fillers. These nanocomposites are light weight and there is tremendous potential in stiffness/weight ratios over conventional materials. In this study, nanocomposites of (NR/SBR) elastomer/short nylon fiber with different amounts of carbon nanotubes were prepared in the presence ofhydrated silica-resorcinol-hexamethylene tetramine (HRH) as bonding agent.

Natural rubber and styrene butadiene rubber (NR/SBR), reinforced with short nylon fibers and carbon nanotubes, were prepared in a two-roll mill mixer. The effect of different amounts of modified and unmodified multiwall carbon nanotubes (MCNTs) between 0 and 3 phr on the mechanical properties, structure and morphology of nanocomposite samples were investigated. The adhesion of the fiber to the rubber matrix was enhanced by the addition of a dry bonding system consisting of HRH. The structure of nanocomposites was studied by scanning electron microscopy (SEM). Findings: By enhancing the amount of modified carbon nanotube and unmodified carbon nanotube, the curing time and the swelling index decreased, while the curing rate and maximum torque increased. The mechanical properties, tear strength, hardness and compressibility were increased as the content of modified and unmodified multi-wall carbon nanotubes increased in both directions of longitudinal (L) and transverse (T) in the nanocomposite. The resilience of nanocomposites was reduced by increasing the carbon nanotube content, and there was a further decrease in the modified nanotube. The microscopy results indicated that by adding carbon nanotubes, specially modified carbon nanotube in longitudinal direction, the fibers pull out and hollow holes decreased at the fracture surface due to the strong bond between the rubber matrix and the fibers and carbon nanotubes. In transverse direction, there was increased pull out and weak bonding

Various samples of poly (vinyl alcohol) have been prepared under different conditions. Temperature and time in the presence of catalyst were assumed as important parameters affecting the properties of poly (vinyl alcohol). The degree of hydrolysis and molecular weight، as dependent parameters، were determined. First the temperature was kept at 45°C and hydrolysis reactions were conducted at different times. To investigate the effect of temperature on hydrolysis process the time was kept constant at 40 min and the reaction was carried out at various temperatures. By considering the various uses of poly (vinyl alcohol) and the properties of its various grades such as solubility، surface tension، resistance in tension، viscosity، the crystallinity properties of various prepared samples were investigated using differential scanning calorimetry. Increasing the time and temperature of the reaction led to higher degree of hydrolysis and lower molecular weight. Molecular weight، thermal treatment، degree of hydrolysis and the type of configuration of the molecules were the most important parameters affecting the crystallinity. Increasing the degree of hydrolysis increased the crystallinity and reduction in molecular weight and in this respect the effect of degree of hydrolysis on crystallinity was more evident than the molecular weight. In order to have similar molecular configuration for raw material the same polyvinyl acetate was used in all the tests. FTIR results showed that syndiotactic structure was dominant and favored the crystallinity. By considering the variation in three parameters during reaction the individual and associated effects of degree of hydrolysis، molecular weight and configuration was investigated on the crystallinity and melting point.

In order to achieve dramatic improvements in the performance of rubber materials، attempts were made to develop carbon nanotube (CNT) -reinforced rubber composites. The maleic anhydride (MAH) modification of EPDM is an interesting way of compatibilizing the EPDM rubber with CNT. Novel ternary nanocomposites were prepared based on EPDM/EPDM grafted maleic anhydride (EPDM-g-MAH) blend composition with various concentrations (0-7 phr) of multi-wall carbon nanotube (MWCNT) on a two-roll mill. The effect of EPDM-g-MAH as a compatibilizer and MWCNT concentration were investigated on cure characteristics، mechanical، morphological and rheological properties of nanocomposites. The microstructure of nanocomposites has been characterized using scanning electron microscopy (SEM). At the same time the rheological behavior has been evaluated by a rubber processing analyzer (RPA). It was found that the cure time (t90) and scorch time (t5) decreased while maximum torque (MH) and minimum torque (ML) of the compatibilized composites were increased with increasing MWCNT loading which was consistent with the swelling data. It is observed that by increasing MWCNT loading the swelling index in solvent was decreased. This can be related to good interactions between carbon nanotube and EPDM matrix in presence of EPDM-g-MAH compatibilizer. The fracture surface study indicated that compatibilizer facilitated a homogenous dispersion of MWCNTs inside the matrix. On the other hand، carbon nanotubes in matrix caused roughness of the fractured surface compared with uncompatibilized samples. The mechanical properties such as tensile strength and elongation-at-break of compatibilized EPDM/MWCNT were higher than those of uncompatibilized nanocomposites. In addition، due to increasing MWCNT content the rheological properties such as storage modulus (G'') increased with respect to angular frequency while the complex viscosity decreased.

Natural rubber and styrene butadiene rubber (NR/SBR) reinforced with short nylon fibers along with nanoclay (Cloisite 15A) hybrid composites were prepared in an internal and a two roll-mill mixer by a three-step mixing process. The effects of fiber content at a constant loading of 3 wt% nanoclay were studied on the microstructure, mechanical and morphological properties of the prepared nanocomposites. The adhesion between the fiber and the rubber was enhanced by the addition of a dry bonding system consisting of resorcinol, hexamethylene tetramine and hydrated silica (HRH). The curing characteristics of the composites were determined and subsequently vulcanized at 150°C using a hot press. It was observed that the cure time and swelling index of the composites decreased while maximum torque, and cure rate increased with increasing of short fiber and nanoclay contents. The structure and fracture surface morphology of the nanocomposites were characterized using X-ray diffraction, scanning electron microscopy. X-ray diffraction results of nanocomposites indicated that the interlayer distance of silicate layers increased. The mechanical properties (tensile, tear strength, elongation-at-break and hardness) ofnanocomposites containing virgin and waste fibers in the longitudinal direction are compared.

Afinite element model of a bias truck tire under static vertical load using aglobal/local technique is designed in two parts. In the first part a previouslycreated model for radial tires is developed to take the constructionalvariables of bias tires into account. It is shown that the technique can successfullybe used for bias tires. The main challenge here is the selection of the initial layout ofthe tire, which due to the use of nylon fibers in bias tires undergo considerable variationin shapes on being released from mold. Therefore, the selection of the tire layoutin the mold as the initial starting point for finite element calculations leads to significanterrors in the final results. In the second part, a highly refined mesh has beencreated from contacting region of the tire tread pattern as a local model. This modelis analyzed using the results of the first (global) model as the boundary condition. Itis also shown that the developed method is capable of precisely predicting the geometryof the footprint area without any extra computational cost and efforts needed infinite element calculations of full tire models

Acrylonitrile butadiene rubber (NBR) composites are prepared from wastenylon 66 short fiber using a two-roll mill mixer. The effects of fiber contentand bonding agent on the mechanical and morphological properties of thecomposites are studied. The curing characteristics of the composites have been studiedby using cure rheometer. The cure and scorch time of the composites decrease whilecure rate is increased when short fiber content is increased. The mechanical propertiesof the composites show improvement in both longitudinal and transverse directions withincrease in short fiber content. The adhesion between the fiber and rubber is enhancedby using a dry bonding system consisting of resorcinol, hexamethylenetetramine andhydrated silica (HRH). The swelling behavior of the composites in N,N-dimethylformamideis tested to find the effect of bonding agent on adhesion strength of the matrixand fibers. Fracture surface morphology of composites is studied by scanning electronmicroscopy. The restriction to swelling is higher for composites containing bondingagent, especially, in the longitudinal direction. The morphology of the fracture surfaceshows less fiber pull out when the bonding agent is introduced

Natural rubber/fiber composites were prepared in a laboratory mixer using new and waste short nylon fiber by a one-step mixing process. Fiber loading and bonding agent effects on the microstructure and mechanical properties of the composites were studied. The cure characteristics of composites were investigated by using rheometer. Cure and scorching times of the composites decreased while maximum torques increased with increasing fiber loading. The mechanical properties of the composites improved with increasing the short fibers. The adhesion between the fiber and the rubber was enhanced by the addition of a dry bonding system consisting of resorcinol, hexamethylene tetramine and hydrated silica (HRH).