@article { author = {Boostan, A. and Massah, S. R. and Ghodrati Amiri, GH.R.}, title = {Seismic Response of 4-Legged Self-Supporting Telecommunication Towers}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {107-126}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Telecommunication tower is an important component of the basic infrastructure of communication systems and thus preserving them in events of natural disasters - such as a severe earthquake - is of high priority. In past studies, researchers have mostly considered the effects of wind and earthquake-induced loads on 3-legged (triangular cross-section) self-supporting steel telecommunication towers. In this study, the seismic sensitivity of 4-legged telecommunication towers is investigated based on modal superposition analysis. For this purpose, ten of the existing 4-legged self-supporting telecommunication towers in Iran are studied under the effects of wind and earthquake loadings. To consider the wind effects on the prototypes, the provisions of the TIA/EIA code are employed and the wind is treated as a static load throughout the analysis. In addition, to consider the earthquake effects on the models, the standard design spectrum based on the Iranian seismic code of practice and the normalized spectra of Manjil, Tabas and Naghan earthquakes have been applied. Since Iran is considered to be located in a high seismic risk region, a base design acceleration of A = 0.35 g is used for normalization of the spectra. It was observed that in the case of towers with rectangular cross section, the effect of simultaneous earthquake loading in two orthogonal directions is important. At the end, a number of empirical relations are presented that can help designers to approximate the dynamic response of towers under seismic loadings.}, keywords = {Seismic response,Earthquake and Wind Loadings,self,Supporting 4,Legged Telecommunication Towers}, url = {https://www.ije.ir/article_71645.html}, eprint = {https://www.ije.ir/article_71645_019ae2a60057ee02c287da9ae61a9135.pdf} } @article { author = {Hassanpour, Hamid and Razzazi, M.R.}, title = {Design and Implementation of a Software System for Detecting Orthographical or Morphological Errors in Persian Words}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {127-132}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {This paper presents a new method for analyzing words in the Persian language context to find orthographical and structural errors regardless of the meaning. This technique tokenizes each word in a statement then tries to detect the kind of word, and analyses its correctness in terms of orthography and morphology by means of a lexicon. It should be noted that some words in the Persian language have the same stem, which are constructed by adding particles to them according to certain rules. For these words the researchers present a new method to reduce the size/volume of the lexicon and to quicken in searching.}, keywords = {Orthographical Error,lexicon,stem}, url = {https://www.ije.ir/article_71647.html}, eprint = {https://www.ije.ir/article_71647_ee8ec26900f3f9b3f0bcf224cf498fdd.pdf} } @article { author = {Sadrnezhaad, S.K. and Mos'hefi Shabestari, Z. and Mos'hefi Shabestari, Z. and Haghshenas, D. F. and Darvishi, D. and Keshavarz Alamdari, Eskandar}, title = {Leaching Recovery of Zinc, Cobalt and Manganese from Zinc Purification Residue}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {133-140}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {This paper reports on the recovery of zinc, cobalt and manganese by two-step leaching of zinc-plants purification residue with sulfuric acid. The residue, hot filter press cake (HFC), contains 14 % ZnO, 4.8 % Co3O4 and 22.9 % MnO. Effects of different parameters are determined and used to optimize the process. With acid to hot filter press cake (HFC) stoichiometry of 0.85, acid concentration of 30 g/L and temperature of 25ºC, it took two minutes to separate zinc from zinc plant residue. Hydrogen peroxide (H2O2) was used as an oxidation agent. The most suitable acid concentration for leaching of both cobalt and manganese was 50 g/L. Recovery of cobalt and manganese increased with peroxide concentration in the leaching solution.}, keywords = {Leaching,Recovery,Hydrometallurgy,Zinc Plant Residue,Filter Press Cake}, url = {https://www.ije.ir/article_71649.html}, eprint = {https://www.ije.ir/article_71649_b6f25579e46d3a32b4212b3a54bc4b24.pdf} } @article { author = {Nahid, P. and Moslehi, P.}, title = {Heavy Metal Removal from Water and Wastewater Using Raw and Modified Diatomite (TECHNICAL NOTE)}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {141-146}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {heavy metal removal from water and wastewater was investigated by using raw and modified diatomite from Iranian mines. Modification of diatomite was done by impregnating the diatomite surface with 0.35 g of manganese oxide in one gram of diatomite. This modified diatomite was named Mn-Diatomite. The surface area measurements for Mn-diatomite showed a 2.2 fold increase, hence higher removal capacity for the heavy metals. The results of the removal showed an increase in adsorption capacity which was for Pb2+ about 40 mg/g, for Ni2+ about 34mg/g and for Cu2+ about 33mg/g. The filtration quality of diatomite was significantly enhanced with surface modification by manganese oxide.}, keywords = {Diatomite,Mn,heavy metals,Adsorption and Wastewater}, url = {https://www.ije.ir/article_71651.html}, eprint = {https://www.ije.ir/article_71651_dd1ccab688b98f66f027659f0f3c86b5.pdf} } @article { author = {Norouzi, M. and Salmanpour, S. and Ideris, A. and Najafpour, Ghasem}, title = {Acid Hydrolysis of Pretreated Palm Oil Lignocellulosic Wastes}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {147-156}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Palm oil solid wastes consist of cellulose, hemicellulose and lignin. In this study, a single stage of acid hydrolysis process of palm oil empty fruit bunch (EFB) for production of fermentable sugar was carried out under moderate temperature (45°C) and ambient pressure. The effect of four different process variables such as solid size, HCl concentration, solid percentage and temperature were investigated. In addition, the effect of pretreatment with 0.5-1M NaOH solution in acid hydrolysis was also investigated. Smaller particles provided more surfaces for acid-solid contact and longer reaction time was necessary if the large solid particles were used. High acid concentration improved the reaction rate and sugar yield. Therefore, the sugar yield was found to be dependent on acid concentration and the employed temperature as well. For a reaction time of 40 minutes, 5 % EFB solid with 15, 20, 25 and 30 percent of HCl, EFB lignocellulose fibers conversion of 36, 60, 65 and 80 % were achieved, respectively. The sugar concentration in acid hydrolysis of the pretreated fibers with 0.5 M sodium hydroxide solution resulted in 35 % more sugar.}, keywords = {Acid Hydrolysis,Pretreated Fibers,Agro,Wastes,Fermentable Sugars}, url = {https://www.ije.ir/article_71653.html}, eprint = {https://www.ije.ir/article_71653_6ea64b2bd2b1efc150b2141350fd860d.pdf} } @article { author = {Shahmiri, M. and Kharrazi, Y. H. K.}, title = {The Effects of Gating Systems on the Soundness of Lost Foam Casting (LFC) Process of Al-Si Alloy (A.413.0)}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {157-166}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {The effects of gating systems, number of runner, and their locations, in the Lost Foam Casting (LFC) of Aluminum alloy (A.413.0) were investigated. Six different gating systems, with one or two running systems were designed. X-ray radiography and the three axis-bending tests have been employed to evaluate the casting soundness and quality. The results revealed that gating systems have a major effect on the formation of the casting defects, i.e. the bottom gated produced the lowest porosity and folded, in comparison with the side and the top gated systems respectively. The number of runners, which is the melt filling entrance to the mold, can either eliminate or reduce the casting defects, whilst the increased number of runners with the reduced surface area can increase the formation of the defects.}, keywords = {Lost Foam Casting (LFC),Aluminum Alloy (A.413.0),Gating System,Runners}, url = {https://www.ije.ir/article_71654.html}, eprint = {https://www.ije.ir/article_71654_3540b4f98ab6ba30c30e97621f097a61.pdf} } @article { author = {Amanifard, Nima and Hosseini, S.M.}, title = {Presenting a Modified SPH Algorithm for Numerical Studies of Fluid-Structure Interaction Problems}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {167-178}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {A modified Smoothed Particle Hydrodynamics (SPH) method is proposed for fluid-structure interaction (FSI) problems especially, in cases which FSI is combined with solid-rigid contacts. In current work, the modification of the utilized SPH concerns on removing the artificial viscosities and the artificial stresses (which such terms are commonly used to eliminate the effects of tensile and numerical instabilities) as well as decreasing the CPU time with achieving more accuracy and the easier programming in comparison with other methods in the similar cases. The mentioned performance of the proposed algorithm is assessed by solving a test case including deformation of an elastic plate subjected to time-dependent water pressure. The obtained results are in close agreement with other high accuracy methods and experimental results.}, keywords = {Smoothed Particles Hydrodynamics (SPH),Fluid,Structure Interaction (FSI) Models,Lagrangian Method,solid,Rigid Contact,Deformation of an Elastic Plate}, url = {https://www.ije.ir/article_71656.html}, eprint = {https://www.ije.ir/article_71656_f035366d5d8ac27533b929421f6932e1.pdf} } @article { author = {Farhanieh, B. and Roshandel, R.}, title = {Numerical Simulation of Non-Uniform Gas Diffusion Layer Porosity Effect on Polymer Electrolyte Membrane Fuel Cell Performance}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {179-192}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Gas diffusion layers are essential components of proton exchange membrane fuel cell since the reactants should pass through these layers. Mass transport in these layers is highly dependent on porosity. Many of simulations have assumed, for simplicity, the porosity of GDL is constant, but in practice, there is a considerable variation in porosity along gas diffusion layers. In the present study the porosity variation in GDL is calculated by considering the applied pressure and the amount of water generated in the cell. A two dimensional mathematical model is developed to investigate the effect of stack compression and water generation on porosity of GDL and cell performance. The validity of the model is assessed by comparing the computed results with experimental data. The results show that when the electrical current density is low, the porosity variation in the gas diffusion layer has no significant influence on the level of polarization whereas at higher current density the influence is very significant. It is also shown that, the electrical current has a sharp gradient across the catalyst layer. Therefore, the better cell performance could be achieved by adding a certain amount of catalyst loading to each electrode, with respect to the reactant concentration.           }, keywords = {Simulation,Polymer Electrolyte,Fuel Cell,Gas Diffusion Layer,porosity}, url = {https://www.ije.ir/article_71658.html}, eprint = {https://www.ije.ir/article_71658_393050d2c915ad0577af954deb800338.pdf} } @article { author = {Babaei, R. and Sohrabi, A. and SavadKouhi, L.}, title = {Research and Assessment of Applying Dimethyl Ether “DME” Extracted from Natural Gas “Ng”, on Diesel Engine as a Clean Fuel (TECHNICAL NOTE)}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {193-201}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Due to the shortage of liquid hydrocarbon fuels for compression ignition engines, researchers have constantly been looking for alternative fuels. Recently, dim ethyl ether (DME) with its interesting properties, such as high cetane number and low exhaust emission has drawn a lot of interst as a suitable fuel for diesel engines. The main objective of this study was to assess the potentials and feasibility of using DME in a diesel engine by designing a suitable fuel injection system that would generate a basis for future optimizations and developments. For one model of diesel engines, a new fuel injection pump was designed and manufactured. A series of performance tests based on ISO procedure were performed, and the results showed that DME used in the newly designed fuel injection pump can compete fairly well with the conventional diesel fuel system as far as power and torque output is concerned. Proposals for future development are also presented.}, keywords = {Dimethylether,Alternative fuels,Fuel Injection Systems}, url = {https://www.ije.ir/article_71660.html}, eprint = {https://www.ije.ir/article_71660_04391fc5f21374d5766e91546a67e46e.pdf} } @article { author = {Moghassem, Abdolrasool}, title = {Study on the Damaging of Dyed Cotton Fibers with Direct Dye in Spinning Processes and its Effect on the Properties of Cotton Mélange Yarn}, journal = {International Journal of Engineering}, volume = {20}, number = {2}, pages = {203-210}, year = {2007}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {The influence of dyeing and spinning on the characteristics of cotton fibers and its impact on the properties of cotton mélange yarn has been investigated. Grey cotton fibers with mean fiber length and fineness of 29 mm and 4.2 micronair were pre-treated and dyed. Three ring yarns were spun from 100 % grey cotton (R.R.Y), 50-50 % blend of dyed and grey cotton (M.R.Y) and 100 % dyed cotton fibers (D.R.Y). The extent of fiber damage was assessed by measuring the length and the mechanical characteristics of cotton fibers after passing the lap machine and the draw frame II. Consequently, properties of R.R.Y, M.R.Y and D.R.Y yarn samples were examined. According to the results, the tenacity and elongation at the break of grey and dyed cotton fiber were very close together. Differences between fibers length by weight and number, nep, short fiber content of grey and dyed cotton fiber were meaningful. There is not a meaningful difference between the elongations of three yarn samples. Tenacity of the R.R.Y yarn sample was the highest and coefficient of mass variation (Cv %), imperfections and hairiness of this yarn sample was the lowest in comparison with those parameters for M.R.Y and D.R.Y yarn samples respectively.}, keywords = {Cotton Mélange Yarn,Dyed Cotton Fibers,Grey Cotton Fibers,Extent of Fibers Damage,Short Fiber Content}, url = {https://www.ije.ir/article_71662.html}, eprint = {https://www.ije.ir/article_71662_a1feb2472b9b4954b2ee3676b04b8233.pdf} }