INTERNATIONAL JOURNAL OF INDUSTRIAL ENGINEERING AND PRODUCTION MANAGEMENT (IJIE) (INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE) (PERSIAN)
Year:2001 | Volume:12 | Issue:2|Papers Count:17

In recent years applications of artificial neural networks are extended to the analysis and design of structures. In this paper a general introduction is provided to the neural networks, and their applications to the problems in the field of structural analysis. Networks with single layer and multiple layers are considered for this purpose. The networks trained can be used as a fast structural analyzer in nonlinear analysis and optimal design of structures. Examples are included to illustrate the efficiency of the present nets.

This paper introduces a stochastic dynamic programming (SDP) model which considers water demand as a state variable. This model called uncertain demand SDP (UDSDP), is a developed form of variable demand-driven advanced models. In this model demand is converted from deterministic to stochastic form. At first, using available climatic data and methods of determination for evapotranspiration of crops for a region in Isfahan, Iran, the time series of irrigation demand is built. Subsequently, the statistical characteristic of this time series is calculated to incorporate demand uncertainty in optimization model.Optimal policies of UDSDP model are evaluated for Zayandeh-rud riverreservoir system in a real time simulation model. Reliability indices of this model is calculated and compared with the results of a deterministic demand optimization model. This comparison shows the ability and effectiveness of UDSDP model especially when the value of demand uncertainty is significant relative to other uncertainties in reservoir operation model.

One of the problems that often happens in activated sludge systems is poor settling and compactibility of sludge in secondry clarifiers. Poor settling of sludge causes decreasing quality of treated wastewater and increasing cost of sludge treatment.In this project, causes of poor settling and compactibility of sludge was determined by experimental method in Zargandeh wastewater treatment plant (Tehran). In the first stage, sludge settling characteristics were determined by caculating sludge volume index (SVI). Because one of the causes of sludge rising and floating is denitrification in the second stage, denirtification phenomenon was investingated by measurment of nitrogen in varius compounds. In the third stage, sludge flocs was investigated by microscope for determining flocs structure and bulking phenomenon and consequently, identificating filamentous bacteria. The dominat bacteria that cause bulking in Zargandeh wastewater treatment plant is M. parvicella and secondary bacteria is type 0092. The growth of these bacteria probably was arised from low F/M, low DOES and completely mixed hydroulic regime of the aeration basin. In the fourth stage, design criteria and operation parameters of the treament plant were controled. The comparsion of these data have shown that this system has hydroulic over load.

Distributed sediment yield models may be improved by using remote sensing to identify land cover classes and RADAR precipitation data as input. Sediment yields are calculated separately for each land cover class and then routed downstream. Calibration and validation are accomplished with data from an experimental watershed. The model simulated run off hydrographs which correlated closely with those observed. The sediment discharge graphs were comparable to observed data.

Electro kinetic remediation is a promising technology for contaminated clayey soils. In order to estimate the efficiency of process on different soils, knowing the interaction of simultaneous different processes is very important. The results of electro kinetic process are water flow, ion and species migration against an electrical field.In this paper the feasibility of phenol removal from kaolinite using Electro kinetic remediation is investigated. Results of three one dimentional tests at constant current condition are presented. The tests were conducted for about 50 hours. Variations of pH, electrical gradient, electro osmotic flow and phenol concentration in anode and cathode chambers as well as soil specimen were measured.The efficiency of phenol removal along the soil specimen was calculated at the end of each test. In one case more than 80 percent of phenol removal was achived from soil sample. Results indicated that electro kinetic remediation is suitable for phenol removal from contaminated clayey soils in short time. Further experiment needed to evalute the efficiency of this technology on contaminant removal of natural polluted soils.

Infilled materials affect characteristics of steel frames. This will considerably change the resistance, internal forces, period, and other characteristics of infilled steel frames, as compared with linearly behavior of steel frames. Therefore inelastic behaviour of infilled materials and frames, especially after crack development, needs to be investigated. In this paper, a compatable model of ANSYS is used for nonlinear analysis of infilled frames. The results show the improvement of steel frames performances when infilled materials are used under some special provisions.

Recently, Sequencing Batch Reactors (SBRs) are used for wastewater treatment in many industries. This system has many advantages in treating wastewaters from industries such as petrochemical, food and etc. Industrial wastewaters have important impact on the environment. Discharging of these wastewaters to the receiving bodies does always have unavoidable effects on the physical, chemical and biological characteristics of the environment. Iran Wood Fiber Company is one of the factories that pollute The Caspian Sea. Considering of high organic content and high suspended solids of the effluent wastewater, choice of the proper way for decreasing and removing pollutants before discharging to the environment is necessary.The objective of this biological treatment was using Sequencing Batch Reactors in laboratory pilot scale for treating the wastewater from Iran Wood Fiber Company.The results indicated that SBRs system with one day detention time and C/N/P=100/5.1/1 has the best efficiency with 92, 84, 52 percent removal in COD, turbidity and total solids, respectively.

A reinforced concrete deep beam is one of the structural members which is used in highrise building basement slabs, shear walls, bridges, dams and offshore structures. They are specified by their span to depth ratio, and generally a deep beam refered to a beam with span to depth ratio less than 5. In this paper behavior and failure modes of 18 simply supported deep beam with span to depth ratio less than 3 loaded from the top mid-span considered. The experimental results indicate the main failure is shear, when small amount of main flexural reinforcement (0.004bde), used the beam failed in flexural and when high amount of main reinforcement (0.017bde), used the beam failed in bearing. Furthermore; for the analysis of the beams the existing methods and proposed method are used. The results of existing methods are not consistence and about 30-60 percent conservative, whereas the proposed method has given safe, consistence and accurate results.

The free undamped vibration analysis of a shell of general shape is formulated with a degenerated curved lagrangian finite element, without neglecting shear deformations and z/R with consistent mass matrix. The shell element with nine nodes and 45 degree of freedoms (three transverse and two rotations) is applicable for both thin and thick shell analysis. The accuracy and efficiency of this proposed finite element are illustrated by examples and the results are compared with those obtained by other analytical and numerical methods. The comparisons show that the method yields very good results with a relatively small number of elements.

Boundary element method is adopteato estimate the hydrodynamic pressures of reservoirs on dams due to the dynamic forces. In this paper, mathematical model in three dimensional form is presented in time domain and a set of computer 'programs are developed to determine these pressures. Different models of dam- reservoir are chosen for the investigation of the effect of bed slope of reservoir and variation of pressure along the height of dams due to the dynamic excitation. The hydrodynamic forces along the length of the crest of dams are also studied. The results obtained from three dimensional analysis are compared with two dimensional analysis of Westergard and Chopra, and are presented in this paper.

The economic values of human-being lives lost in rural road accidents in Iran and also the cost of permanent disabilities, grief and mental injuries are discussed and evaluated.First, different scientific views concerning how to monetize the non monetizable items are presented. Then their actual effects on road construction and maintenance projects are illustrated. New scientific views concerning "human capital" and the "Comparison of GNP and court verdicts, methods" are followed. Finally, the result and few useful proposals are presented.

In comparsion between the different systems of transportation consideration type and amount of cargo type of the path and it's geographical spacifications and also the volume of damand for cargo transportation, almost any system or transportation will be more economical than the others.For the time being, the needed fuel for Tehran Railway Station which consists 30% of the fuel consumption of the Iranian Railways is supplied by Rey Refinary the fuel is transported to tehran Railways station by tank cars. In this paper after an evaluation of existing systems of fuel transportation, the fuel transportation by rail for Tehranian Railway Station has been discussed. And then the other forms such as road and pipe transportation has been compaired with the rail type, and their possibility and cost analysis has been presented and finally among all the ways of fuel transportation to the Tehran Railway Station, the optimum way has been proposed.

Determination of cohesion and angle of internal friction of the asphalt is of special importance for designing and estimating the bearing capacity of asphalt mixtures. This is usually done by performing the triaxial test. To perform such experiment, however, advanced experimental equipments and experienced people are needed.In the present study, a new method to determine the cohesion and angle of internal friction parameters of the asphalt is introduced. This method is based on using the unconfined compression and indirect tensile tests instead of triaxial test to measure the shear strength parameters (C,f). In the present study, asphalt samples with different size distribution, percentage of filler, percentage of fracturing and percentage of bitumen were made and tested against Unconfined and indirect tensile experiments. Based on the results obtained from these experiments, the Mohr- Coulomb circles were plotted and cohesion and angle of internal friction of asphalt were determined using Mohr- Coulomb theory. To assess the validity of the results, the Hveem test was performed on the samples with similar characteristics as tested samples with unconfined and indirect tensile experiments and the relation among the results was obtained and analysed.

One of the important topics in geotechnical engineering is determination of critical slip surfaces of slopes. In this paper, the Genetic Algorithm (GA) is used to find the minimum factor of safety of a slope. This method, which can solve slope stability problems both in homogeneous and heterogeneous eath slopes, is a non-classical optimization technique. Solving a few slope stability problem, it becomes evident that GA is a powerful optimization method which can easily find the global minimum safety factor of a slope and the corresponding slip surface.

Unequal settlement in special structures is of great importance since it can cause additional stresses in upper structure. In cooling towers due to long foundation and often ununiform condition of subsoil and also because of different internal. Forces in columns which specially are caused by wind load, unequal settlement is of most probable and the structure must be design for it.In' this paper a mathematical model was defined for unequal settlement of cooling towers and was applied to shahid Montazeri power plant extension cooling towers and the influence on the state of stress and displacement in shell, columns and foundation ring was considered.