farshbaf

CCR5 is known as a main co-receptor in HIV infection. Many studies demonstrated that 32bp deletion in both CCR5 alleles provide natural resistance to HIV infection, so new treatment approaches are based on inducing this resistance by means of gene and cell therapies. This projects aim was the discovery of suitable candidates for new therapeutic strategies in addition to determining the CCR5 Δ32 mutation frequency in healthy individuals in Zanjan province for the first time.
Blood samples were collected from 200 healthy individuals in EDTA pre-coated tubes. Genomic DNA was extracted and analyzed for CCR5 Δ32 mutation by GAP-PCR. The allele frequency was calculated using the Hardy-Weinberg equilibrium (HWE).
Our findings showed 1 healthy individual had CCR5 Δ32/Δ32 mutation and the allele frequency of CCR5Δ32 was calculated to be 0.5%.
Results of this study proved previous reports that Iranian populations are more susceptible to HIV/AIDS compared to the European population. Different climate-geographical conditions, migration and positive natural selection could explain various distribution of Δ32 allele frequency in European countries compared to Iran. Consequently, Iranians require more effective and novel therapeutic approaches for HIV infection therapy and could benefit from reducing retro-viral drug restrictions.

Due to low porosity and slow water flow in clayey soils, the dominant pollutant transport mechanism may be molecular diffusion. The effect of consolidation of clayey soil on the chloride diffusion coefficient was investigated. The soil sample was collected from Nazloo region on North West of Urmia. After determination of soil physical parameters, the consolidation parameters were obtained. For determination of the chloride diffusion coefficient at different degrees of consolidation, when the cylindrical soil sample reached a certain degree of consolidation in the consolidation apparatus, the diffusion test was conducted and the diffusion coefficient was measured. This was conducted by the computer code POLLUTE by fitting the computed data on the observed concentration-time data. The results showed that by increasing the degree of consolidation and decreasing the soil void ratio from 0.4 to 0.35, in the range of stresses from 25 kPa to 400 kPa, the diffusion coefficient decreased from 5.94×10-10 m2/s to 5.36×10-10 m2/s. In the unloading process of consolidation from 400 kPa to 50 kPa the diffusion coefficient increased from 5.36×10-10 m2/s to 5.42×10-10 m2/s. The results of this study showed that the process of pollutant migration by molecular diffusion in the fine grained clayey soil of Nazloo was dependent on the degree of consolidation of the soil but the effect of consolidation on the decrease of soil diffusion coefficient is not significant. The good agreement between the observed and predicted data showed that the designed physical model, the adopted laboratory procedures and the theoretical model had good accuracy.

One of the important aspects neglected in the literature related to cell formation problem is human issues. In this study, a bi-objective mathematical model is developed in which human issues and dynamic cell formation are taken into consideration simultaneously. The rst objective function deals with costs associated with machines and human issues. The costs of human issues relate to salary, hiring, ring, reward/penalty policy, and worker assignment. The second objective function takes into account labor utilization as a criterion for reward/penalty policy. Since the available time in di erent real conditions is not constant, we include learning e ect to consider the real workers time. The nature of dynamic cell formation problem is NP-hard, and thus a Linear Programming embedded Genetic Algorithm (LP-GA) is employed to solve the model. In order to improve the performance of the applied GA, its parameters are tuned by means of Central Composite Design (CCD) method. Moreover, to validate the LP-GA, some test problems are solved and the results are compared with those obtained from an exact method and GA. The computational results show that the near optimal solutions yielded by LP-GA are better than GA in large-sized problems.

The aim of this research is to investigate triggering of fault slip due to stress perturbation caused by hydraulic fracturing. The importance of this issue is to study the observed destructive effects of dam construction at locations adjacent to the superficial faults. Therefore, we use the Matlab programming and SimDesigner system as an analytical extension. Concentrated stresses are applied after defining the nodes for fracture surfaces. By having the fault surface, analyses start to reach an equilibrium state. By defining the reaction forces in boundary condition, comparison of nodal dislocations become possible. The basis for vertical stress calculation is the upper rock layer and for horizontal stress is Coulomb failure stress. We estimate the stress perturbation through theory of tip stress about tensile fractures. The resultant stress field obtained combination of fractural and regional stresses gives primary condition to study triggered fault slip and related earthquake magnitude. The results show a maximum 2 meters of cumulative slip along the fault surface close to the hydraulic fracturing. Based on moment magnitude of earthquake calculations, this slip gives a magnitude of 3.8 upon the Richter scale. This process needs the increased precision for nodal dislocations and optimized finite elements in order to better improve the future works.

Several algorithms are developed for speed estimation and sensorless control of induction machines which among them, reduced-order based methods have proved acceptable performance. In this paper, a reduced-order speed estimation method, is introduced for sensorless control of DFIGs, in which, rotor currents and stator fluxes are used as state variables and dynamic of rotor currents error is applied to extract adaptation mechanism. Since current dynamic is faster than flux dynamic, proposed observer dynamic is improved. Dynamic stability of proposed method is demonstrated using Lyapunov stability criteria. The suggested speed estimation algorithm is confirmed utilizing a laboratory setup, in addition to simulations. Laboratory setup is based on a 16-bit DSPIC and practical results are extracted using a 250 watts induction machine. Both simulation and practical results show effective and stable operation of proposed method, especially at speed tracking.

Context and There are stories in Medias and scientific and political communities’ organizations that acquire nuclear weapons. The latest and the most catastrophic kind of terrorism is nuclear terrorism. This paper deals with nuclear terrorism and strategies to combat it with an international approach. This paper is descriptive- analytic and library based. Since now nuclear terrorism in its narrow sense the use of nuclear weapons by terrorist groups- has not happened; but in its other instances, it has largely happened. Nuclear terrorism has become one of the biggest problems and concerns in the international level. This concern is serious that former UN secretary General Kofi Annan on 1 October 2001 at the General assembly stated that “a terrorist attack with nuclear weapons can kill millions while the world was not even able to prevent the 11 September terrorist attacks.” In addition, in his last major report in 2005, he considered the nuclear terrorism a global treat and the future challenge of international community. Also, the presidents of many western countries believe that nuclear terrorism is the greatest treat to their national security. Security council Resolution 1540 in 2004, amending the convention on physical protection of Nuclear Materials and ratifying the International Convention on the suppression of nuclear terrorism are among activities that have been done in international level to deal with terrorism.

Power system stabilizers (PSSs) must be capable of providing appropriate stabilization signals over a broad range of operating conditions and disturbances. The main idea of this paper is changing a classic PSS (CPSS) to an adaptive PSS using genetic algorithm. This new genetic algorithm based on adaptive PSS (GAPSS) improves power system damping, considerably. The controller design issue is formulated as an optimization problem that is solved by GA to identify PSS parameters in various operating conditions. Numerical simulation studies have been done on a modified model of IEEE second benchmark. The consequence of these studies shows that, the performance of the suggested genetic algorithm based adaptive PSS in damping of electromechanical oscillations of power system is better than CPSS.

Tuning parameters has the most important effect in performance of Neural Network. Main problem in using of ANN is parameter tuning because there is no definite and explicit method to select optimal parameters for the ANN parameters. In this study, three artificial neural network performance criteria and also three important factors which affect the selected criteria have been introduced. Moreover, Box-Behnken design has been applied to analyze the ANN structure parameters and its performance. The proposed approach has been implemented for a simulated process according to a complex mathematical function. After extracting relation between controllable factors and performance criteria, fuzzy programming is used for finding the optimal combination of controllable factors in order the best performance of Neural Network. Results attained from the numerical example show efficiency of the proposed method. Generally, proposed approach can be used for tuning of neural network’s parameters in other problems.

In this paper, a combinational optimization algorithm is introduced to obtain the best size and location of Static Compensator (STATCOM) in power systems. Its main contribution is considering contingency analysis where lines outages may lead to infeasible solutions especially at peak loads and it commonly can be vanished by load-shedding. The objective of the proposed algorithm is firstly to prevent infeasible power flow solutions without undesired load-shedding, which is critical in contingency analysis; and secondly to mitigate overall power losses and costs. Moreover, active and reactive powers generation costs are considered in the proposed objective function. Since there are various constraints such as lines outages number, cost and their duration that must be taken to account, Bacterial Foraging oriented by Particle Swarm Optimization (BF-PSO) algorithm combined with Optimal Power Flow (OPF) is used to solve and overcome the complexity of this combinational nonlinear problem. In order to validate the accuracy of the proposed method, two test systems, including IEEE 30 bus standard system and Azarbaijan regional power system of Iran, are applied in simulation studies. All obtained optimization results show the effectiveness of the suggested combinational method in loss and cost reduction and preventing load-shedding.

method combines the two conventional chopper and Kramer methods to control the slip power of the motor. The mentioned method acts in two modes، first the drive is forced to chopper control for starting up the motor and then the system switches to the Kramer control when motor passes the 80% of the reference speed. The combined converter eliminates the conventional resistor starters of the traditional Kramer converters and also provides speed sensorless control of the drive. Furthermore a sensorless control scheme is proposed which eliminates DC offset problem of some conventional methods. Simulation results show that the system reduces some drawbacks of the two conventional methods. Finally a low power laboratory set-up is constructed to show some dynamic behaviors of the combined method. In the laboratory set-up، a chopper controlled converter is designed and using a real-time control system، speed sensorless control and start-up process is successfully performed.

The total concentrations of six elements (Pb, Cu, Zn, Ni, Cr and Co) were determined in soil samples from surrounding of Tehran cement and smelting factories. The samples were analyzed by XRD analysis. The abundance of heavy metals, measured in these soils, decreases as follows: Pb > Zn > Cr > Cu > Ni >> Co. The relationship between concentration of each heavy metal and different parameters such as soil pH, type and amount of clay, organic matter, cation exchange capacity (CEC), amount of calcium carbonate and iron and aluminum oxides contents were determined. Any parameter can be detected as clearly related to each heavy metal content but Fe-oxides, Al-oxides, clay content, pH significantly and SiO2, sand percent and CEC to a lesser extend have most influence to heavy metal absorption. The results indicate high levels of Pb pollution, low to moderate levels of Cu and Zn pollution in studied soils. The source of these elements are found to be of anthropogenic origin. These soils are unpolluted with respect to Ni, Cr and Co. These elements are originated from the natural sources.