@article { author = {Ehsani, M.R. and Rajaie, H. and ramezanianpour, A and Momayez, A.}, title = {Experimental Investigation of the Methods of Evaluating the Bond Strength Between Concrete Substrate and Repair Materials}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {319-332}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {This investigation was aimed at studying the effect of test methods on bond strength between concrete substrate and repair material. Four test methods with cementations or modified-cementations repair materials, and two surface roughnesses were studied. The methods used were pull-off, slant shear, splitting prism and a new direct shear named Bi-Surface shear test. While the coefficient of variation for each type of test was acceptable, the bond strengths from some tests were up to 8 times larger than those obtained from others. It is imperative that the bond tests be selected such that they represent the state of stress the structure is subjected to in the field. The new test method was easy to carry out and had reasonable results and can be developed by further investigations.  }, keywords = {Concrete,Repair,Bond strength,Shear strength,Silica fume,Test Method}, url = {https://www.ije.ir/article_71389.html}, eprint = {https://www.ije.ir/article_71389_4a7565693e8a496d47fc1e31a9ac415d.pdf} } @article { author = {Mohammadian, E. and Noorzaie, J.}, title = {Seismic Response of the Kavar Concrete Face Rockfill Dam (RESEARCH NOTE)}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {333-346}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {This study deals with the dynamic behavior of the kavar concrete Abstract face rockfill damwhich is the first dam of this type to be const ructed in a highly active seismic prone area,situated in the state of Fars southern part of the Islamic Republic of Iran. The finite elementmethod was used as a tool to carry out this study. The finite element discretization was carriedout under plane strain condition by representing the body of the dam, rock system, berm onupstream and the concrete slab through an eight noded isoparametric element. To account forthe interfacial behavior between concrete slab and the body of the dam, the joint element hasbeen utilized. By using direct integration technique, analysis of the behavior of the dam for theaverage section was carried out. It has been found that the dam is safe with respect to designbasis level (DBL) earthquake record.}, keywords = {Seismic response,Dam,Rockfill,Kavar,Earthquake,Concrete,Finite Element,Fars}, url = {https://www.ije.ir/article_71392.html}, eprint = {https://www.ije.ir/article_71392_20abf61c062614fe03a9a2806d947d49.pdf} } @article { author = {Sadr Karimi, Jamshid}, title = {Geotechnical Properties of Lacustrine Carbonate Sediment}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {347-356}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {Results of laboratory tests on specimens produced from subsoil studies were evaluated tocharacterize geotechnical properties of Tabriz Marl. It was concluded that, Tabriz Marl may be considered as a high liquid limit silt or clay (MH & CH). Range of changes of index, physical and mechanical properties of the Tabriz Marl are comparatively vast. Correlation between these properties has been introduced in this paper. A representative specimen was tested for swell potential after compaction and also for thermal and lime treatment effects. Swell percent and pressure as high as 13.6 % and 1020 kPa were measured and need for treatment was proved. It was shown that with thermal treatment substantial modification only starts as the temperature rises beyond 300° C. At 500°C the plasticity index and also the swell percent decrease to less than 5.0 % and 1.0 %, respectively. With lime treatment, plasticity index decreases as the lime content is increased until the lime fixation point is achieved at about 3 % lime content, beyond which, modification effects are not considerable.Addition of just 1.0 % lime to the soil decreased the swell potential to 5.0 %. Further results, merits and shortcomings of both treatment methods are introduced during the text.}, keywords = {Marl,Swell Potential,Lime Treatment,Thermal treatment}, url = {https://www.ije.ir/article_71394.html}, eprint = {https://www.ije.ir/article_71394_852a8cabad3bf7d4ea59fd0a4635f3f5.pdf} } @article { author = {Sadrnejad, S. A.}, title = {Hydrodynamics Induced Vibration to Trash Racks (TECHNICAL NOTE)}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {357-368}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In conventional power plants trash-racks are provided at the intakes to protect the turbines. In pumped storage plants, the draft tube or tailrace must also have trash-racks to protect the units while pumping. Because the loads believed to cause many failures of trash-racks are dynamic in nature, it is important to understand the dynamic characteristics of trash-rack structures in general and a single rack in particular. The classical added-mass solution structure-fluid dynamic interaction is known as an approximate solution procedure. An accurate added-mass approach mixed with implementation in finite element framework is proposed. In this proposal, experimental conclusions, supported by theory, led to presentation of more accurate results in vibration of trash-racks. This numerical solution as a powerful method to solve such a complex problem can be employed to carry out dynamic characteristics of these structures while vibrating in water.}, keywords = {Trash,racks,Natural frequency,Numerical Solution}, url = {https://www.ije.ir/article_71397.html}, eprint = {https://www.ije.ir/article_71397_561c05e520a6eac31c360ad481db246d.pdf} } @article { author = {Collier, Michael}, title = {An Intelligent Computer Interface Utilizing Parallel Picocontrollers (TECHNICAL NOTE)}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {367-370}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {The design of an interface unit is described, in which RS232 serial data is converted to latched parallel data on 22 independent lines. The data direction of each line is programmable through the serial port. Two picocontrollers are employed in a parallel processing mode to give the required number of I/O pins, and data on the shared serial line is coded to separate data streams to the individual picocontrollers, and to avoid contention. The hardware configuration and the software for both the computer and microcontroller are described. The speed penalty of such a system compared with direct bus connection is analyzed.}, keywords = {Computer Interface,Picocontroller,Serial Communication}, url = {https://www.ije.ir/article_71399.html}, eprint = {https://www.ije.ir/article_71399_cab0c42d95b017a193a29f72b86c0204.pdf} } @article { author = {Haese-Coat, V. and Saryazdi, S. and Ronsin, J.}, title = {Visual Pattern Image Coding by a Morphological Approach (RESEARCH NOTE)}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {371-378}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {This paper presents an improvement of the Visual Pattern image coding (VPIC) scheme presented by Chen and Bovik in [2] and [3]. The patterns in this improved scheme are defined by morphological operations and classified by absolute error minimization. The improved scheme identifies more uniform blocks and reduces the noise effect. Therefore, it improves the compression ratio and image quality is steel preserved. To achieve a better compression ratio, a hierarchical approach based on the merging of uniform blocks is also described. Experimental results show that the improved scheme provides higher compression ratios compared to ordinary VPIC.}, keywords = {Image Compression,Visual Pattern Image Coding,Mathematical Morphology}, url = {https://www.ije.ir/article_71400.html}, eprint = {https://www.ije.ir/article_71400_789181d861539de5b3688cc6ecfd8839.pdf} } @article { author = {Collier, Michael and Sibanda, M.}, title = {The Opportunities Afforded by Embedded Computer Systems for Monitoring and Control of Industrial Processes in Less-Industrialised Countries (TECHNICAL NOTE)}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {379-384}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {The dramatic changes in integrated-circuit technology over the last two decades have been of great benefit to countries such as Zimbabwe. High volume production of VLSI chips has produced a supply of intelligent, versatile electronic processing devices at very low cost. In particular the facilities of the microcontroller have steadily developed to the accompaniment of a reduction in price. Since, in essence, the microcontroller is a complete computer tailored to control and monitoring operations, one is now provided with a device capable of application to a great variety of industrial and domestic situations. The major challenges lie in the interfacing and programming of the devices, and these are cerebral skills with which many less-industrialized countries are well endowed. The paper examines the opportunities in the embedded-systems area by means of a number of case studies of real industrial problems, whose solution has been achieved through these techniques.}, keywords = {Embedded Computer,Picocontroller,Zimbabwe,industrial research}, url = {https://www.ije.ir/article_71402.html}, eprint = {https://www.ije.ir/article_71402_74d80f379bbbf5501f362eb4f2a42936.pdf} } @article { author = {Asayesh, M. and Behzad, M.}, title = {Vibration Analysis of Rotating Shaft with Loose Disk}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {385-393}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {In this paper energy method is used to calculate rotor response with loose rotating disk on it. System equation of motion is obtained based on energy method and Lagrange equation. Mathematical modeling of loose disk in a rotor bearing system has resulted in terms similar to unbalance and gyroscopic effect in the system equation of motion. The effect of loose disk axial position and orthotropic bearing has been considered in this investigation. By assuming that shaft and loose disk are always in contact, the results of these study shows that clearance between loose disk and shaft, shaft speed, mass and mass moment of inertia of disk have a major effect on a rotor response and beating phenomena.}, keywords = {Loose Rotating Part,Rotor Dynamics,FEM,Machine Diagnostic}, url = {https://www.ije.ir/article_71404.html}, eprint = {https://www.ije.ir/article_71404_efb239d905c42a98cd09c0af67ab7663.pdf} } @article { author = {Sheikhzadeh, G. A. and Mansouri, S. H. and Mehrabian, M. A.}, title = {The Overall Heat Transfer Characteristics of a Double Pipe Heat Exchanger: Comparison of Experimental Data with Predictions of Standard Correlations}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {395-406}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {The single-phase flow and thermal performance of a double pipe heat exchanger are examined by experimental methods. The working fluid is water at atmospheric pressure. Temperature measurements at the inlet and outlet of the two streams and also at an intermediate point half way between the inlet and outlet is made, using copper-constantan thermocouple wires. Mass flow rates for each stream are also measured using calibrated rotameters. Heat is supplied to the inner tube stream by an immersion heater. The overall heat transfer coefficients are inferred from the measured data. The heat transfer coefficient of the inner tube flow (circular cross section) is calculated using the standard correlations. The heat transfer coefficient of the outer tube flow (annular cross section) is then deduced. Higher heat transfer coefficients are reported in the laminar flow regime in comparison to the predictions of standard correlations for straight and smooth tubes. The reasons for this discrepancy are identified and discussed. Experimental errors in measuring temperatures and mass flow rates are studied and their effects on the heat transfer coefficients are estimated. Experimental results for the range of operating conditions used in this work show that the outer tube side heat transfer coefficients are smaller than the inner side heat transfer coefficients by a factor of almost 1.5 and 3.4 in counter flow and parallel flow arrangements, respectively. The agreement with predictions is very good for the counter flow arrangement, but not very good for the parallel flow arrangement.}, keywords = {Double Pipe Heat Exchanger,Heat Transfer Coefficient,Inner Tube Flow,Outer Tube Flow}, url = {https://www.ije.ir/article_71406.html}, eprint = {https://www.ije.ir/article_71406_cfd724d21b8e7c70ebe33aafc656a417.pdf} } @article { author = {Alamdar Yazdi, A.}, title = {Evaluation of the Shearing Properties of Woven Fabrics: Rated Force}, journal = {International Journal of Engineering}, volume = {15}, number = {4}, pages = {406-416}, year = {2002}, publisher = {Materials and Energy Research Center}, issn = {1025-2495}, eissn = {1735-9244}, doi = {}, abstract = {This paper introduces a very simple way to evaluate low stress shearing properties of woven fabrics with the advantages of simplicity and easy accessibility. A 200-gram load is applied on small portion of the sample instead of applying the load overall width of the fabric. As a result, buckling of the fabric will happen and the loading-unloading curve will show the behavior of the fabric during the deformations. Initial slope after buckling and the gap area between loading-unloading curves above the buckling point are the elements, which could show the shearing behavior of the woven fabrics.}, keywords = {Low Stress,Shearing Properties,Woven Fabrics,Critical Point,Buckling Point,Concentrated Force}, url = {https://www.ije.ir/article_71407.html}, eprint = {https://www.ije.ir/article_71407_9075b824ff9afedb18cc491388443645.pdf} }