جستجوی مقالات مرتبط با کلیدواژه « non » در نشریات گروه « مهندسی شیمی، نفت و پلیمر »

The effects of N-methylpyrrolidone (NMP) concentration contained in bore fluid and coagulation bath temperature were studied with respect to the structure as well as the performance of the polysulfone hollow fiber membranes. In order to determine the structural characteristics of prepared membranes, a set of analyses including scanning electron microscopy (SEM), mechanical strength test, pure water permeability and mean pore radius of surface pores were used and separation of 1 g/L solution of collagen protein was studied to determine the performance of the membranes. The obtained results from SEM analysis showed that at constant coagulation bath temperature, the increase in NMP concentration in bore fluid increased the number of pores in the inner surface of membranes, decreased the formation of finger-like voids and increased the mean pore radius of the pores and also sponge-like pores near the inner radius of hollow fiber membranes. Moreover, pure water permeability and mechanical strength of the prepared membranes increased about 160% and 44%, respectively with increases in the content of NMP in bore fluid. In addition, at constant NMP content of 40% in bore fluid, pure water permeability increased by above 92% as the coagulation bath temperature increased from 30°C to 50°C, whereas the mechanical strength decreased by 32%. Finally, it was revealed that the rejection of the prepared membranes in the separation of collagen protein solution decreased by increasing NMP content in the bore fluid at constant coagulation bath temperature and also deacreased by increasing coagulation bath temperature at constant NMP content in the bore fluid.

Formation of condensates around the wellbore in gas condensate reservoirs reduces the efficiency of well performance, and it can be intensified depending on the fluid type, reservoir and well properties. Adequate and appropriate information can be helpful for accurate modelling of gas condensate reservoirs. Disregarding the dependence of gas-oil relative permeability on capillary number and high the velocity flow (non-Darcy flow) may cause miscalculations and poor estimations in gas condensate reservoirs. In this paper, a sector model of South-Pars gas condensate field located in the Persian Gulf was simulated using ECLIPSE-300, and the effect of the capillary number and non-Darcy flow on cumulative condensate production and condensate formation near the wellbore and in the reservoir were investigated. Obtained results reveal that production increases as the bottom-hole pressure decreases and/or the production flow rate increases; however, more pressure drop and condensate blockage were occurred. Thus, bottom-hole pressure and the production flow rate should be optimized for efficient production. In addition, taking into account the effect of the capillary number on relative permeability decreases condensate formation near the wellbore and in the reservoir. Non-Darcy flow increases pressure drop, resulting in more condensate blockage near the wellbore. Ignoring the effect of the capillary number and non-Darcy flow in simulation process will strongly affect the accurate prediction of well performance in gas condensate reservoirs.

At non-ideal multicomponent adsorption systems, adsorbed phase behavior is not well predicted by ideal adsorption solution theory (IAST). At these systems, real adsorption solution theory (RAST) can present more accurate predictions by introducing adsorbed phase activity coefficients provided that they are obtained with a suitable thermodynamic model. In this paper, RAST with Wilson equation was develop for modeling of adsorbed phase behavior. In obtaining activity coefficients of components, Gibbs–Duhem equation at only constant temperature was utilized because the spreading pressure varies at the adsorption process. According to the results of the systems investigated, it was revealed that the model reduces the average prediction errors to about 10% (in worst case) while it is more than 50% by IAST.

The formulation, gun and safety of the sticky foams as a non-lethal weapon are studied. Sticky foams are one of the polymeric materials which have specific properties such as low density, high adhesion and suitable tensile strength. Sticky foams are a type of pressure-sensitive adhesive ()PSA) which are mixed with a foaming agent. Sticky foams are prepared by blending different compounds such as thermoplastic elastomers, tacky resin, surfactant and foaming agent. The foams are stored in tanks under pressure and released to atmospheric pressure at a desirable time. In addition, increase in the amount of the tacky resin and softener will lead to enhancement in the adhesion properties. The weapon needs a pressure vessel for storing the sticky foam formulation in order to release the sticky foam. Weight, throwing power and sticky-foam storage capacity are important parameters associated with asticky foam gun. Contacting the skin surface of the bodywith a sticky foam leads to irritation and local inflammation. Long-term continual exposure may lead to cancer due tooil derivatives and heavy hydrocarbons present in the sticky foam formulation. Sticky foams have various applications in obscuring the military sites, weakening the visibility of the military tools such as tanks and combatting insurgency in prisons and street demonstrations.

Solar dew technology is a suitable technique for saline oily wastewater treatment using renewable solar energy. It is a good option for wastewater treatment in desert oil fields. The material which is used in this system is a non-porous hydrophilic membrane. The membrane is a non-porous and thus does not allow salts to pass; so this is a non-fouling and non-scaling membrane and there is no need for any water pretreatment. Different kinds of saline oily wastewater can be used as the influent. In this study, preparing and evaluation of membrane were considered. A membrane from Akzo Nobel Company, which is used in solar dew pilot at Sarkhoon gas refinery, was chosen as a reference. After the characterization of the membrane, it was produced by blow molding technique and then its physical and mechanical properties and vapor permeation were evaluated. Finally, the analyses of sea water and Sarkhoon gas refinery wastewater passed through the membrane were evaluated and the results were compared with the same system without a membrane. The study on physical and mechanical properties of the used membrane showed a high tensile, impact strength, and elongation. The results of the water vapor permeability of the membrane compared with porous membranes show a high performance of this membrane for using in the pervaporation system. As the membrane production is economic, it is a good candidate for using in solar dew systems.

Precipitation polymerization is almost one of the newest polymerization procedure used for producing micro and nano polymer particles. Even it is favorable for producing various kinds of copolymers or inorganic-organic nanocomposites. Due to catalytic or indicator properties of these materials, precipitation polymerization has find more interested in literature. Nanoprecipitation polymerization is a novel subsection of this kind of polymerization that is used for manufacturing of block copolymers. The scientific behavior of this polymerization depends on many factors such as the initiator and monomer concentration and especially, kind of the used non-solvent, as here the effect of these factors, separation methods and available scientific theories for synthesizing various kinds of copolymers or inorganic-organic nanocomposites are investigated. Also, the advantages of this polymerization in comparison to other kinds of polymerization such as better control on the molecular weight of polymers and polymer particle morphologies, in absence of stabilizers should be analysized, as well.

In this research، batch kinetic experiments were carried out for the sorption of Reactive Red 198 onto magnetic activated carbon. Effect of pH and contact time on the adsorption process was studied. The equilibrium time decreased with agitation of solution. The experimental kinetic data were fitted to the pseudo-first order، pseudo-second order، and intra-particle diffusion models by linear and non-linear methods using Mathematica software. The results showed that non-linear method is the most appropriate method to predict the rate kinetic parameters. Also، dye adsorption kinetics followed both pseudo-second order and intra-particle diffusion models. J. Color Sci. Tech. 9 (2015)، 225-238©. Institute for Color Science and Technology.

In this work, the changes of drilling mud viscosity have been studied and Cross and Bingham plastic model parameters were determined based on some reported experimental data. For the non-Newtonian behavior of drilling mud, Cross model has a better prediction than the other models. Moreover, an analytical solution was derived for fluid with Cross model and a 2D numerical code was developed to solve momentum and continuity equations with a finite volume method. For the validation of the code, the velocity profiles and friction coefficient of Newtonian and non-Newtonian fluids in pipes and annulus were calculated and compared with the results of theoretical relations and analytical solutions. The results show good agreement and the friction factor error for Cross model is 5%, while, for Bingham model, it is 12%. Additionally, the flow field for Cross non-Newtonian fluid through the annulus was simulated and the results were presented in dimensionless terms. The friction factor in fully developed region and the entrance length was calculated and for the prediction of these two quantities, two new correlations were presented as a function of Reynolds number.

In this paper, a modified formulation of class G cement for manufacturing and production has been proposed. Since the produced industry cements have no proper rheological properties, thickening time, and compressive strength, a new formulation has been proposed on the laboratory scale. The clinker was classified into a wide range of particle sizes and the final cement was prepared by mixing them with gypsum. The designed cement is non-uniform and coarser than conventional cements and 50 percent of particles are in the range of 3-30 µm, which shows a 20-30% decrease in the aforementioned range as compared to standard cements. Although the designed cement has very good rheological properties, thickening time, and lesser water usage about 10% which causes a higher 24-hour compressive strength, there is a lower early compressive strength when compared to standard cements. Hence the production system was changed from ball mill and sieves to production by ball mill alone and homogenous cement with the same specific surface area was produced. In addition to having all the desired properties, by a 10% decrease of water usage in the cement system, the early compressive strength was improved by 21% compared to standard cements based on quality control results. Moreover, this production system can completely be implemented at the production plants.

Research Institute of Petroleum Industry (RIPI), Tehran, Iran [email protected] Relative permeability is one of the most important parameters affecting reservoir performance; it is determined from experimental measurements (e.g. cores), which can be time consuming and costly. Considering the relationship between relative permeability and resistivity, the relative permeability of phase diagrams (wet and nonwet) can be estimated by using resistivity data. This study determined the relative permeability by using resistivity logs in one of the Iran oil fields and compared it with experimental results. In view of the availability of resistivity logs from oil wells, this research can play an important role in the feasibility study of estimating the relative permeability by resistivity logs, which could be valuable in terms of saving time, economics, and dynamic reservoir simulation.

Due to the difference between price and value of natural versus synthetic dyes, it has always been very important to distinguish these two categories for handmade carpet. This study aimed to investigate Near-IR spectrometry technique to identify natural madder and synthetic dyes used in handmade carpets. To do this woolen samples with two major races (Baluchi and Kermanshahi) were dyed with madder dye with alum and tin chloride mordant, and also synthetic dyes to provide conventional red-colored shades. The 60 dyed samples including of 24 madder, a set of 10 mixed (combination of Madder and synthetic dyes), 26 synthetic dyes, and 5 cases gotten from carpet, and in total 65 samples were prepared. Results showed that the spectral reflectance of the madder samples has an increasing slope in NIR region while the NIR spectral reflectance of synthetic dyes does not show any noticeable increasing trend. Considering the obtained results of this research, NIR spectrometry can be a feasible method to distingush between madder and synthetic dyes and it was quiet possible for the test samples with almost no errors. However, investigating on more samples would be suggested. Note that it is not possible to detect samples dyed with a mixture of madder and synthetic dyes. The mixed samples were presented in one of the two groups; synthetic or madder.

In this article which is the outcome of a joint project between Science and Industry University of Iran and Shishe Va Gas co, an assessment on the laboratory scale production of four different groups of Non – fluoride opals is carried out.In this project ten samples of calcium- phosphate opals with different chemical compositions, five samples of calcium – zinc - phosphate opals, twelve samples of spontaneous calcium – magnesium opals and fourteen samples of spontaneous calcium opals were produced in laboratory.In all tests, the completely mixed batch was heated at 1450 °c in a high alumina refractory crucible for 2 hours. The molten glass produced was then poured into a small preheated steel mould (at 400 °c) with the dimensions 150×20×20 mm.Finally all the glass samples were annealed at Tg + 5 °c for 30 minutes.The problems facing the melting and fining of opal batches, and also the effect of chemical composition (specially with respect to alakali and alkali earth oxides) on the opacity of glass samples are considerered and discussed thoroughly. Physical and chemical properties of opal glass samples including dilatometric curves, opacity, bending strength, resistance to alkaline and acidic solutions were tested according to standard procedures, and the results are presented in the article, Based on these results, the optimum chemical composition for each group of opal glasses is advised.