AMIRKABIR
Year:2006 | Volume:17 | Issue:64-D (TOPICS IN: GROUPS OF ENGINEERING, TEXTILE, POLYMER, CHEMISTRY)|Papers Count:12

Melt grafting of maleic anhydride onto SBR with a peroxide initiator has been studied by use of an internal mixer (Brabcnder plasticorder). The percentage of crosslinking (gel content) was measured by titration and the results was compared with FTIR spectrographs. It was revealed that both grafting and crosslinking reaction proceed simultaneously at all formulaticlls and depend on the amount of maleic anhydride and peroxide.High grafting with low gel content was achieved at low concentrations of maleic anhydride (1phr) and benzoyl peroxide (0.06phr).Processing parameters in eluding temperature and material feeding method and fill factor were studied.

The printing and ink manufactures industries, have constantly been under pressure to replace the various hydrocarbon solvents used in the ink and coating formulations. water based inks and coatings technologies have been the primary vehicles in this drive to replace hydrocarbons and other pollutants in the workplace and in the community. In the present paper the effect of varying formulation of water based inks on their properties were studied. Three variants, ie the amount of solid content of the resin, the amount of pigment and the mixture of two resins were considered. The special cubic experimental design was used in order to optimize the formulation. on this basis a series of water based flexography ink in three hues ie, blue, red and yellow were prepared and were subsequently applied on pre-treatment polyethylene sheets. Gloss, adhesion, abrasion resistance, and friction coefficient were then measured. Stat-Ease software was used to plot the contour lines on the triangle diagrams.

The effects of erosive burning of solid propellant in a prototype motor have been investigated through "Interrupt Burning" method. The motor is composed of three internal-external combustion cylindrical propellant in motor section with the L/D ratio of 5 and one two-ended internal combustion cylindrical propellant in test section. Erosive burning will be examined taking into consideration of three working pressures and mass flux that occurred in the port. In this paper, a new equation will be introduced in which the effects of mass flux, burning rate, combustion chamber pressure and motor dimensions are included. The prototype motor will be tested and then the obtained results will be used to determin the parameters of the proposed. Therefore an applicable equation in grain designing will be obtained.

Glucose isomerization to fructose by immobilized glucose isomerase as an example of solid-liquid enzyme reaction has been studied in a down flow jet loop reactor (DJR). Conversion of glucose to fructose has been measured and compared with that formed in a batch reactor. The performance capability of the DJR was observed to be higher than that of the conventional reactors. The optimum operating conditions of the reaction system have been also determined using the Taguchi experimental design method. The effects of enzyme loading, draft tube diameter, position of nozzle inside the draft tube, and gas and liquid flow rates on glucose conversion have been considered. Analysis of the results revealed that the draft tube diameter has the highest and the ratio of the liquid circulation rate to the gas flow rate has the least effects on the conversion of glucose. It was found that the experimental data could be correlated favorably with a mofidied structure of the michalis-menten model consisting of two transition complexes.

In this paper, bubble formation process has been studied numerically by entering air into a submerged orifice placed in a cylinder. The SOLA-VOF method was used to simulate the bubble formation. In This code, complete form of Navier-stocks equations was predicted two dimension and using finite difference method. Also in this study, the effect of air flow rate on the bubble size and its formation time at very low rates was studied.

Color constancy and metamerism are two phenomena that take place when the spectral power distribution of illuminant is changed. The difference between the color inconstancies of the metameric pairs is the source of metamerism.In present study, 98 actual metameric pairs were used to find the relation between these phenomena. The results showed that after parameric correction, the value of metameric index in the color difference group was equal to difference between their color inconstancy indices with acceptable approximation. The accuracy increased when the metameric indices were calculated after adaptation.

In this research the effect of combing process on physical and mechanical properties of cotton rotor yams and the fabrics woven from these yams is studied. Also, the effect of rotor diameter and combination of rotor diameter and rotor groove angle on the yam properties are studied. For this purpose, combed and carded rotor yams were produced with the count of 30Ne from a blend of 4 types of cotton and then were used in woven fabrics construction as weft yam.The results show that combing process reduces the CV% of yarns and improves the strength. It also decreases the twist insertion ratio and hairiness of yams. The dye absorption of combed yams is better than the carded one.It was also seen that the strength, bending and abrasion resistance of fabrics woven from combed yams is more than carded yarns, but the drape is less. Furthermore, It was considered that the air permeability of fabrics woven from combed yams is higher than carded ones. The statistical t-student tests were carried out in 95% confidence interval by using SPSS 9.0 software to evaluate the combed and carded yarn properties. The obtained results confirm the statistical difference between the produced yarn and fabric samples of combed and carded rotor yarns.

In the present study, the catalyst preparation and reaction kinetic modeling of syngas transformation into dimethyl ether using a mixture of a metallic oxides, (CuO, ZnO, Al2O3) and an acidic component (g-Al2O3) as catalyst has been investigated. Twenty three catalysts were prepared according to a pre-designed research program consisting of four phases. In each phase, applying the Taguchi experimental design method, a number of catalysts was synthesized by co-precipitation method, using different percent of metal nitrates solutions. It was noted that the ZnO content of the catalyst, the nature of the precipitant agent, mass ratio of gamma-alumina to total metal oxides and calcination temperature, had the highest impacts on the activity of the catalysts.Catalysts activity and kinetic measurements were carried out using a catalytic fixed bed micro reactor. The operating temperature range was 230-300°C and the pressure was 8 barg. The experimental mns were performed applying a wide range of catalyst to feed ratios. A kinetic expression devised, based on Graff model for methanol synthesis and Bercic model for methanol dehydration and was correlated with the experimental results obtained in this study. The degree of agreement between the two sets of data was 90-95%.

The northern part of the city located in higher elevations is of the main concerns in Tehran during winter which leads to the shortage in gas supply. To deal with this problem, National Iranian Gas Company (NIGC) decided to store gas in nearby natural reservoirs during hot season and produce it during cold season. Sarajeh gas condensate reservoir was considered for UGS to deal with gas demand. In this study, we first present the significance of UGS, different types of reservoirs considered for UGS and its history. Next, using GEM software, a coarse grid model of the reservoir is built. Then, simulation and history matching of Sarajeh gas field are introduced and briefly discussed. Finally conclusions and recommendation for future work is presented. Based on available information and those results generated by the model, this field could be a candidate for UGS plan. The results showed that two horizontal and one vertical gas production wells need to be drilled to achieve pressure drop in the reservoir and deliver 150 MMSCF of gas per day including production from former producers. Reservoir performance after history matching using depletion scenarios is predicted. Depletion last for 4.5 years. Ultimate recovery factor is 65% for gas and 40% for gas condensate. Following reservoir depletion to approximately 2400 psia, gas injection cycles in 6 months during hot season with the injection rate of 160 MMSCF per day and gas production cycles in 5 months in cold season with the rate of 175MMscfD can start. Total gas volume stored in each cycles is approximately 0.84x1012m3.

In this research, a film-model-based for gas sweetening by alkanolamine is considered and three different approaches to the solution of the CO2 mass transfer- reaction in the liquid film are studied. Also the results are compared with each other and pilot plant data. The first approach is based on numerical method for solving nonlinear boundary value problem. The second approach requires a simplification of differential transport equation by assuming uniform amine concentration in liquid film and bulk of liquid. The third approach is polynomial method and furthers these two later methods, by taking advantage of an analytical technique. Numerical method was solved by complex matrix solution. Advantage and disadvantage of these methods are analyzed and investigated. The three models have good agreement with pilot plant data.