@article { author = {Ale Ebrahim, H. and Jamshidi, E.}, title = {a New Approximate Solution Technique (Quantized Method) for Simultaneous Gas Solid Reactions}, journal = {International Journal of Engineering}, volume = {9}, number = {4}, pages = {181-188}, year = {1996}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Simultaneous reactions between solids and gases are very important in the chemical and metallurgical processes. In the modeling, the chemical reaction and diffusion of gases must be considered. Therefore, a set of coupled partial differential equations is found. When the kinetic is a function of solid concentration, there is not any analytical solution for these equations. Therefore, numerical or approximate solutions have been used. In this paper a new approximate method has been developed for solution of two gases-one solid reaction equations. This technique offers some new mathematical expressions for rapid calculations. The results of this method are compared with the existing solutions. The quantized solution shows a better accuracy than other approximate method.}, keywords = {New Approximate Solution,Simultaneous,Gas,solid Reactions}, url = {https://www.ije.ir/article_71160.html}, eprint = {https://www.ije.ir/article_71160_6fba430ee224e799019107505e6034c2.pdf} } @article { author = {Abbasi, A. and Faiz, Jawad.}, title = {Analysis of Shaded Pole Induction Motors Considering Asymmetrical Flux Distribution and Saturation Effects}, journal = {International Journal of Engineering}, volume = {9}, number = {4}, pages = {189-200}, year = {1996}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Several methods are available for performance prediction of single phase shaded pole induction motors. A simple model, in conjunction with a more complicated and accurate model, which considers the asymmetrical windings and core loss, is used to compare the prediction methods against experimental results. Saturation is incorporated in the model. Fundamental and harmonic flux density wave distributions under the pole are determined by employing the accurate mathematical model of the motor and the influence of the shading angle upon this distribution is shown. The effect of airgap length upon the torque speed characteristic of the motor is also investigated.}, keywords = {Induction motor,Shaded Pole,Single Phase Motor,Saturation Effect,Asymmetrical Windings}, url = {https://www.ije.ir/article_71161.html}, eprint = {https://www.ije.ir/article_71161_b76837e0f537b99c8b65ee2cce238283.pdf} } @article { author = {Baradaran Rahimi, A.}, title = {Pressure Calculation in the Flow Between Two Rotating Eccentric Cylinders at High Renolds Numbers}, journal = {International Journal of Engineering}, volume = {9}, number = {4}, pages = {201-210}, year = {1996}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {This paper reports the result of an analytical investigation of a steady, incompressible and viscous flow between two eccentric, rotating cylinders at high Reynolds number. A one dimensional case is far from reality because the gap between the cylinders is very small. Further, when their axes are displaced by a small distance, usually caused by bearing loads, two dimensional effects become obvious. Here the equations of motion are perturbed and made linear. Then utilizing the boundary layer theory, these equations are solved for the case of large Reynolds number. The results are compared to those of other works.}, keywords = {Pressure Calculation,Rotating Cylinders,Perturbation Method}, url = {https://www.ije.ir/article_71162.html}, eprint = {https://www.ije.ir/article_71162_9636ce3190631b7086dd490424a97e3f.pdf} } @article { author = {Rahmani, A. A.}, title = {Spherical Oil Agglomeration (SOA)/ Colloidal Gas Aphrons (CGA) Flotation}, journal = {International Journal of Engineering}, volume = {9}, number = {4}, pages = {211-220}, year = {1996}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {The main aim of this experimental work was to develop a separation process using micro- bubbles less than 100 µm in diameter. Micro-agglomerates were produced using 10kg crude oil/tone feed coal treated compared to 250 kg/tone feed coal treated for conventional spherical oil agglomeration. These micro-agglomerates were separated from the unagglomerated minerals by micro-bubble flotation. Colloidal Gas Aphrons, CGA, were produced by using various surfactants. Sodium lauryl sulphate (SLS) surfactant was chosen for the production of CGA because it is thought that its anionic character would depress the flotation of the mineral particles. The combination of micro-agglomeration followed by "Dry CGA" flotation was an effective process in coal de-mineralisation under laboratory conditions. All the particles were-45 µm in size.}, keywords = {Spherical Oil Agglomeration (SOA),Colloidal Gas Aphrons (CGA),dmm,Recovery,Grade,Micro,agglomerates,Spinning Disc,Aphrons Generator,Cleaner,Rougher,Scavenger}, url = {https://www.ije.ir/article_71163.html}, eprint = {https://www.ije.ir/article_71163_3b4a68f9ff73f8766ec0042e544beda6.pdf} } @article { author = {Ghahraman, B.}, title = {Giuh- Gciuh Comparison for Two Watersheds in Iran (RESEARCH NOTE)}, journal = {International Journal of Engineering}, volume = {9}, number = {4}, pages = {221-230}, year = {1996}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Two representative watersheds, Ammameh and Kasilian, located in Southern and Norten Elborz mountain in Iran respectively were considered. Fourteen events of rainfall-runoff in nonmelting seaons were chosen and their storms and flood hydrographs were gathered from an automatic recording station. Base flow separation was made by recession limb analysis while Philip equation was used for the calculation of effective rainfall. The ordinates of Instantaneous Unit Hydrograph (IUH) was determined by using the GcIUH and GIUH theory for each rainfall-runoff event separately. Direct runoff hydrographs were determined by convoluting IUH and effective rainfall hyetograph. Mean flow velocity and kinematic wave parameter were correlated to peak discharge separately. Therefore, these indices were estimated for each rainfall-runoff event, knowing its peak discharge. It is found that GcIUH shows a better results for all determination of its value may be the main reason for predicting less accurate results. GcIUH, on the other hand has lower sensitivity to kinematic wave parameter variations. Mean while for wide channels, this parameter does not depend on discharge.  }, keywords = {IUH,GIUH,GcIUH,Flood Forecasting,Representative Watersheds}, url = {https://www.ije.ir/article_71164.html}, eprint = {https://www.ije.ir/article_71164_aa57a2cd0f0b57d5e907232194c7903b.pdf} } @article { author = {A. Jeddi, A. A.}, title = {Studies Into the Omission of Take-Down Tension System in Circular Kniting Machanes (TECHNICAL NOTE)}, journal = {International Journal of Engineering}, volume = {9}, number = {4}, pages = {231-233}, year = {1996}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {This paper reports on an attempt to modify a circular knitting machine such that it would operate without the need for a customary tension system where a kinitting machine can operate without an asymmetric take-down system preliminary results appear promising and warrant further development. }, keywords = {Circular Knitting Machine,Take,down Tension System,Double Jersey Fabric,Dial Neelde,Cylinder Needle,Yarn Breakage}, url = {https://www.ije.ir/article_71165.html}, eprint = {https://www.ije.ir/article_71165_de8321c82b1ec4213efa3c83653426e0.pdf} }