علیرضا ردایی

Emulsifying porous polymers have many pharmaceutical and industrial applications and are considered as new materials for separation. In this research, first the emulsion synthesis of poly (styrene-di vinylbenzene) was performed and then the effect of increasing the functional group of sodium styrene sulfonic acid on the hydrophilicity of the emulsion porous polymer poly (styrene-divinylbenzene) was investigated. Scanning Electron Microscope to study surface morphology and determine the size distribution of surface cavities and Energy Dispersive X-ray analysis test to investigate the presence of sulfur and sodium atoms in the surface of functionalized porous polymer and contact angle measuring device with Coupled-Camera Devise(CCD) and with software for measuring the contact angle of droplet contact with the surface to evaluate the hydrophilicity of the surface of polymerized emulsion polymer poly (styrene-divinylbenzene) were used. Increasing sodium styrene sulfonic acid has no effect on the shape and size of the cavities formed, but the hydrophilicity of the samples increased with increasing sulfone factor in the aqueous phase and the appropriate percentage of sodium styrene sulfonic acid in the aqueous phase was about 2%. With an increase of more than 2%, a slight increase in the hydrophilicity of the surface of the emulsion porous polymer poly (styrene-divinylbenzene) was activated and the graph became almost flat with slope changes insignificant.

Highly porous polymers are mainly produced by emulsion polymerization. In this study, first the emulsion synthesis of poly (styrene-divinylbenzene) was performed and then the effect of increasing the amount of salt in the aqueous phase on the structure of porous polymer was investigated. Scanning electron microscopy was used to study the surface morphology and determine the size distribution of surface cavities. The appropriate amount of aqueous phase to oil phase for emulsion polymerization and production of porous polymer is at least 75% and adding of one percent of salt in the aqueous phase caused more pores with smaller size on the surface of the porous polymer and by increasing the salt, pores with larger diameter and more uniform distribution were obtained. According to the purpose of the study, which was to create fine surface cavities, the appropriate sample in this field was a sample containing 1% salt with a ratio of water phase to oil phase of 75% to 25%, in which case more cavities with smaller size in two index sizes with distribution uniform and symmetrical scattering with PDI of about 1 with an average diameter of 5.21 μm was obtained.

Superplasticizers can be synthesized in different ways. The aim of this study is to present a two-step method for the synthesis of polycarboxylate ether and to investigate the temperature change in synthesis. In the first stage synthesis, the main chain and in the second stage synthesis, the side chains are created.

The synthesis of the primary copolymer was done by mass method and free radical mechanism. FTIR analysis was performed to identify the functional groups formed according to the predictions and to reach the desired copolymer. Then the copolymer viscosity was determined as a parameter determining the progression of the main chain length and in the second step, polycarboxylate ether was synthesized by solution using an optimized AA copolymer. First, FTIR analysis was performed to confirm the structure and HNMR test was performed to confirm the final synthesis. Then, GPC test was performed to determine the characteristics of the synthesized ether polycarboxylate, including the average molecular weight of the polymer and the molecular weight distribution curve, and MW and PDI values ​​were reported. Finally, the slump test was performed to confirm the performance.

With increasing the temperature of copolymer synthesis, the length of the main chain also increases and the intensity of this increase is higher at high temperatures, but on the other hand, temperatures higher than 70 ° C also caused the destruction of the copolymer, which was detectable in the form of viscosity reduction and discoloration of the solution. Therefore, the initial synthesis should be performed at 70 ° C for 8 hours. The synthesis of polycarboxylate ether with equal molar ratios and maintaining the same conditions and only at different temperatures showed that the best synthesis temperature is 70 ° C for 6 hours. By increasing the molecular weight of polycarboxylate ether, by increasing the side chain, a better slump and flow in concrete was created.

Hypothesis: 

In recent years, much attention has been paid to the use of BaFe12O19 barium ferrite magnetic material in the manufacture of polymer composite magnets. Hence, nitrile butadiene rubber-polyvinyl chloride (NBR-PVC) polymer composite magnets containing barium ferrite alloy powder BaFe12O19 with particles less than 5 microns were made with optimal properties

The effect of different amounts of barium ferrite magnetic powder in the polymer substrate on the magnetic, morphological and mechanical properties of barium ferrite polymer magnets was investigated using SEM images and VSM diagrams and tensile test.

NBR-PVC/ BaFe12O19 composite magnets containing 70 %wt NBR and 30 %wt PVC with 100 units of base rubber (phr) including 2 units of sulfur as baking agent, 4 units of zinc oxide as activator, 3 units of stearic acid as lubricant, 2 units of tetramethyl thioram disulfide (TMTD) and 2 units of mercapto-benzythiazyl disulfide (MBTS) as accelerator and barium ferrite powder BaFe12O19 were fabricated with a particle size of less than 5 microns and a combination of different percentages as a magnetic agent. Among the samples made, N-P/F80 composite magnets with a ratio of 20:80 (powder:polymer) had the highest saturation magnetism of Ms and the residual magnetization of Mr and the lowest intrinsic coercivity of Hc. As expected, the best sample in terms of tensile strength was N-P/F20 with a powder:polymer ratio of 80:20, and finally, according to all the results related to the magnetic, morphological and mechanical properties of the samples, the most suitable one in terms of good particle dispersion in the polymer substrate and suitable tensile strength and appropriate magnetic properties of N-P/F50 with 50:50 (powder:polymer) ratio was selected.

The purpose of this study was modeling some selected method of load carriage during sitting and arising, in order to introduce the best method to reduce energy consumption and risk of injury among troops.
In this research, ten subjects participate to determine the anatomical constraints, record the kinematic of motions and extract some parameters for modeling. Subsequently, the center of gravity position of four equipment for load carriage, including: Backpack, Double pack, Trunk vest and Double satchel, were determined and four different dynamic models of body and the load entered, were developed based on inverse dynamics equations by Lagrangian method. To calculate joint torque and mechanical energy, two dimensional models with four segments were run with kinematics information.
According to investigation results, mechanical energy consumption in Backpack method and hip torque in Double satchel method were lowest.
A more practical choice for military operations is to carry a load as close as possible to the center of mass of the body. In a nutshell, between all methods, carrying operation by Backpack method, according to its capabilities, is the best choice for carrying heavy and bulky equipment.

The purpose of this study is regarding the organizational readiness for deployment of knowledge management with organizational performance in The Power Distribution Company of Yazd province. So in this research is used the EFQM approach to verify this objective. Thus is used the enabling dimensions of this model for assess organizational readiness for knowledge management and the results dimensions of this model for provide indicators of organizational performance. StatisticalSociety of this study is the operationstaff of The Power Distribution Company of Yazd province in year 2011 that table standardMorganwas usedforcalculating thenumberofSample. For collect information is used of the questionnaire. Also is usedof the factor analysis for the validity analysis ofquestionnaire، toexaminethe relationship betweeneach of thedimensions ofknowledge managementandorganizational performanceof thePearson correlation coefficient، toinvestigate the potential ofeach of thedimensions ofknowledge managementonthe organizationalperformance predictionof the Stepwiseregressionmethod. The overall results of this study were to demonstrate that all aspects of the organization''s readiness for deployment of knowledge management are significant and positive relationship with organizational performance.

For improve the operation of one electrochemical system, we must design and optimize internal structure therefore we must study and discussion discharge curves. In this paper for high-energy seawater battery, done the optimization of current collector structure and discharge curves in case of constant current discharge state for variation of voltage with time, study and draw for different condition for optimization of current collector structure. Also study on effect of silver electroplating, effect of electrode surface and effect of current collector thickness in seawater battery.