M-machine Reentrant Permutation Flowshop Scheduling to Minimize Makespan Using Particle Swarm Optimization Algorithm

M-machine Reentrant Permutation Flowshop Scheduling to Minimize Makespan Using Particle Swarm Optimization Algorithm

… Download …


Part of #M-machine Reentrant Permutation Flowshop Scheduling to Minimize Makespan Using Particle Swarm Optimization Algorithm# :

Publishing year : 2015

Conference : International Congress on Management, Economics and Business Development

Number of pages : 9

Abstract: In recent years, the reentrant permutation flowshop has been attracting attention from both researchers and industry. A common assumption in the classical permutation flowhop scheduling model is that each job is processed on each machine at most once. However, reentrant flowhop scheduling allows a job to revisit a particular machine several times. Considering the complexity of the m-machine reentrant permutation flowhop scheduling problem, this paper proposes a particle swarm optimization algorithm to solve the problem with makepan criterion. We perform simulation experiments to test the effectiveness of the proposed algorithm and compare it with existing heuristics. Computational results and comparisons show that the proposed algorithm outperforms the existing heuristics in terms of objective solutions and computing times. Therefore, enterprises can introduce the proposed method to generate profits by fully exploiting its benefits and lower overhead manufacturing costs.

Stress Intensity Factors for a Weld Toe Crack in a Tubular Joint

Stress Intensity Factors for a Weld Toe Crack in a Tubular Joint

… Download …


Part of #Stress Intensity Factors for a Weld Toe Crack in a Tubular Joint# :

Publishing year : 2003

Conference : 6th International Conference on Civil Engineering

Number of pages : 6

Abstract: A sample structural base support with a weld toe crack is considered. Three different types of loading are applied to the structure: a bending moment, a shear load, and a compressive load. Three-dimensional finite element analyzes are used to study variations of mode I and mode II stress intensity factors with crack lengths. Because of complexity in geometry and loading conditions, the crack is subjected to mixed mode loading. It is shown that the stress intensity factor of the mode II is not negligible compared to the mode stress intensity factor. The variations of stress intensity factors with the crack length vary significantly for different loading conditions.

numerical investigation of bearing capacity of strip footing placed on granular soil reinforced with grid anchor system

numerical investigation of bearing capacity of strip footing placed on granular soil reinforced with grid anchor system

… Download …


Part of #numerical investigation of bearing capacity of strip footing placed on granular soil reinforced with grid anchor system# :

Publishing year : 2012

Conference : Ninth International Congress of Civil Engineering

Number of pages : 9

Abstract: In this research, a new reinforcing element, which comprises attaching polymeric elements (anchors) to the common geogridnamed Grid Grid-Anchors for increasing pull-out resistance of reinforcements, is introduced. The effect of the first reinforcement layer, the vertical spacing, the number And the width of reinforcement layers, the angle of anchors, the stiffness of reinforcement and anchors and the distance that anchors are effective. Two-dimensional finite element analysis by PLAXISsoftware indicated Also, the bearing capacity was also found to increase with increasing number of reinforcing layer, if there was a force cement placed within a range of effective depth. In addition, the analysis indicated that the reinforcement and anchor stiffness increase beyond threshold value does not result in Further increase in bearing capacity.

Numerical simulation of plasma actuator effects on flow control over airfoil

Numerical simulation of plasma actuator effects on flow control over airfoil

… Download …


Part of #Numerical simulation of plasma actuator effects on flow control over airfoil# :

Publishing year : 2009

Conference : 17th Annual Conference of Mechanical Engineering

Number of pages : 5

Abstract: In this paper, the effects of plasma acuator on the flow of airfoil with different velocities have been studied. The plasma actuator effect has been simulated by introducing the external body force field into a navier -stokes equation.

STUDY ON MICROSTRUCTURE DEVELOPMENT OF PS/ORGANOCLAY PREPARED BY IN SITU SOLUTION POLYMERIZATION PROCESS

STUDY ON MICROSTRUCTURE DEVELOPMENT OF PS/ORGANOCLAY PREPARED BY IN SITU SOLUTION POLYMERIZATION PROCESS

… Download …


Part of #STUDY ON MICROSTRUCTURE DEVELOPMENT OF PS/ORGANOCLAY PREPARED BY IN SITU SOLUTION POLYMERIZATION PROCESS# :

Publishing year : 2014

Conference : The first national conference on modern technologies in chemistry and petrochemicals

Number of pages : 6

Abstract: The main objective of this paper was to synthesize polystyrene-clay nanocomposites through solution polymerization of styrene monomer in the presence of organomodified montmorillonite (OMMT) clay. Polymerization was carried out in a 500cc laboratory batch reactor (3-neck). The results of the thermal analysis, including the Thermo Gravimetric Analysis (TGA) and the Differential Scanning Calorimeter (DSC), showed a higher thermal stability for those composites samples compared to non-polystyrene. The FTIR characteristic picks of nanocomposites samples were found to be similar to those observed for polystyrene. XRD patterns showed a relatively high degree of intercalation which remained almost unchanged after completing the reaction (after 6 hours). The results of linear viscoelastic measurements performed on the samples showed higher viscosity and storage modules (G ") especially at low shear rate range compared to non-polystyrene by the same polymerization condition. The linear viscoelastic results of the dispersion also showed that increasing the reaction time after 6 Hours do not have an effect on the dispersion of nanoclay inpolystyrene matrix. In addition, after this, due to some side reactions such as the transfer reaction to the solvent occurring in the reactor, and the molecular weight of the samples decreases with increasing reaction time after 6 hours

Cyclometalated Ruthenium (II) Electronic Structure Influence on dye-sensitized solar cell performance: A Density Functional Theory

Cyclometalated Ruthenium (II) Electronic Structure Influence on dye-sensitized solar cell performance: A Density Functional Theory

… Download …


Part of #Cyclometalated Ruthenium (II) Electronic Structure Influence on dye-sensitized solar cell performance: A Density Functional Theory# :

Publishing year : 2015

Conference : International Conference on Environment and Natural Resources

Number of pages : 4

Abstract: According to the problems arising from the use of fossil fuels to generate electricity, solar energy has been considered. One method that can be used for this issue is dye-sensitized solar cell technology. There are several ways to increase the efficiency of a cell, one of which is choosing appropriate color molecules. In this paper, the FT series of colors was selected and the effect of the electronegative group as well as the length of the alkyl chain is examined. All DFT calculations were performed with a plane-wave basis set. According to the results, substituting an electronegative group leads to a reduction in the difference between HOMO energy and potential energy of I- / I3- to facilitate the transfer of electron from I- / I3 to the stable energy. The energy difference between the LUMO of the dye sensitizer and the conductivity band of the semiconductor TiO2 decreases as the substitution takes place on the anchoring bidentate ligand of the Ru (II) complex. Whatever the difference is less; Dye regeneration will be favored and cell efficiency improved. In addition, FT57 is the most effective dye in the considered dyes due to its appropriate electronic and quantum properties. Keywords: Cyclometalated Ruthenium (II) Sensitizer; Dye Sensitized Solar Cell; Efficiency; Conduction band (CB) of TiO2; Oxidized state

Water saving and efficient use in water coolers(Case Study: Ilam City)

Water saving and efficient use in water coolers(Case Study: Ilam City)

… Download …


Part of #Water saving and efficient use in water coolers(Case Study: Ilam City)# :

Publishing year : 2015

Conference : Second International Conference on Science and Engineering

Number of pages : 6

Abstract: Due to the limitations of water resources in terms of quality and quantity, the inappropriate use of water resources, groundwater, treated water, thelack of management and proper systematic planning for the use of water and the past few decades in Iran, A lot of problems have been made in terms of water shortage for this country. Given the critical situation of water in the world and Iran, and the lack of rainfall and low water levels in the Ilam dam, which provides about 90% of the water for Ilam, and the need to save the drinking water that its large volume wastedorconsumed by water coolers in The warm months of the year between June 10th and 17th, we estimate the amount of savings in the cooler with shade and without shade and measure the amount of water consumptionin And, finally, compare these two coolers for an hour according to the coolness and moisture generated by each one as well as the changesin the temperature and the amount of consumed water in them at the same hour of 13:30 pm when is the peak hour of Water heat and vaporization. The comparison of changes in room temperature and the percentage of air humidity for both coolers is almost equal to a minor error rate. The results indicate that the cooler underneath the shade has 2.04liters of water per hour less than the cooler without shade. Ultimately, there are suggestions to improve and reduce the consumption of this system.

Analytical Study of the Transient Motion of a Falling Spherical Particle in Incompressible Newtonian Media, Comparison with HPM

Analytical Study of the Transient Motion of a Falling Spherical Particle in Incompressible Newtonian Media, Comparison with HPM

… Download …


Part of #Analytical Study of the Transient Motion of a Falling Spherical Particle in Incompressible Newtonian Media, Comparison with HPM# :

Publishing year : 2012

Conference : 20th Annual Conference of Mechanical Engineering

Number of pages : 4

Abstract: In this paper, the acceleration motion of a vertically-dropped spherical particle in incompressible Newtonian media is investigated. The instantaneous velocity and acceleration are carried out using a differential transformation method (DTM) which is an analytical solution technique. By using DTM, the nonlinear constrained governing equations are reduced to recurrence relations, and related initial conditions are transformed into a set of algebraic equations. The solutions are subsequently solved by a process of inverse transformation. The current results are then compared with those derived from the homotopy perturbation method (HPM) and the established fourth order Runge-Kutta method in order to verify the accuracy of the proposed method. It is found that this method can achieve more suitable results compared to HPM

Physical and Mechanical Properties of Copolyimide based Fuel Cell Membranes

Physical and Mechanical Properties of Copolyimide based Fuel Cell Membranes

… Download …


Part of #Physical and Mechanical Properties of Copolyimide based Fuel Cell Membranes# :

Publishing year : 2009

Conference : Sixth International Congress of Chemical Engineering

Number of pages : 6

Abstract: Physical and mechanical properties of four series of chemically and thermally stable sulfonated copolyimides as ion-conducting ionomers for application in a fuel cell membrane, depending on the chemical structure of diamine monomers, were studied. The physical and mechanical properties of solid polymer membranes, including thermal stability, mechanical strength, water absorption, water stability and morphology were evaluated. All of the polymers were thermally stable. The SEM micrographs revealed that the hydrophobic-hydrophilic phase separation in the polyimide was not occurred. The use of flexible monomers such as 4,4 "oxidian (ODA) and 4,4" – (4-aminophenoxy) diphenylsulfone (APDS) in the hydrophobic sequences increased the plastic behavior compared to the rigid polymers prepared from 4,4 "- 5-amino-1-naphthoxy) diphenylsulfone (ANDS) and m-phenylenediamine (m-PDA). It was concluded that the properties of polymeric films were strictly dependent on the chemical composition of monomers and the molecular weight of copolymers.

The Effect of Super Viscose and Air Entrainment on Reducing Corrosion of Light Concrete with Leca Aggregate

The Effect of Super Viscose and Air Entrainment on Reducing Corrosion of Light Concrete with Leca Aggregate

… Download …


Part of #The Effect of Super Viscose and Air Entrainment on Reducing Corrosion of Light Concrete with Leca Aggregate# :

Publishing year : 2012

Conference : Ninth International Congress of Civil Engineering

Number of pages : 8

Abstract: Due to high humidity in coastal areas, concrete frame structures are more common than metal frame structures. However, corrosive ions and salts such as chlorine, sodium, various sorts of sulfates and destructive particles within fogs made in these areas, In addition to continuous cycles of structures that become dry and wet, cause aggravating in the destruction of buried concretes in earth and concrete Which is in direct contact with air or sea water proximity. On the other hand, since light concrete generally has more porosity and higher water absorption, it has less strength against adverse effects. That is why, deploying light concrete, despite its numerous advantages, has not been expanded in coastal areas. In summary, this paper deals with the analysis of the effects of viscose materials, air entrainment and anti-sulfate cements upon concrete corrosion, it was done by performing pressure and electrical resistance experiments, and comparing the amount of water absorption in light concrete models that were Constructed with artificial leca aggregate