Abstract: Quadrature-axis reactance for various reasons comes into account as one of the most important parameters of salient pole synchronous machine. There are several common standard methods for measuring this parameter that also have been explained with some details in the standards, scientific papers and text books. One of these methods is the maximum lagging current test that is done simply at no-load, having a three phase voltage source and applying very low power even for a high power machine. How this experiment is done is described at some references such as the books related to electrical machinery. This paper presents a detail analysis and description of the test and some simulation results regarding the performance of the machine during pole-slipping. It is shown when the reversal field current is increased very slowly, the transient of the pole-slipping commences at load angle equal to 45 degrees or by a better language at 225 instead of zero which is the common opinion of almost all the previously published literatures. In this paper, a realistically developed analysis of the test is presented applying appropriate assumptions. The maximum lagging current test is then simulated applying a small salient pole machine with the rated 31.5 kVA using MATLAB/SIMULINK. Some simulation results are illustrated that prove correctness and validity of the new analysis and the proof described by the present paper.

The use of PSS in order to improve dynamical stability of the power systems has been recently increased. For this purpose, there are varieties of methods for determining the controller coefficients of the system stabilizers. If these coefficients are modified in each operational point by adaptive mechanism, the robust performance of the system is improved. In this paper, a new method for determining the coefficients of a self-tuning PSS with lead-lag controller based on pole assignment and pole-shifting techniques is presented. In the design procedure, the required identification in self-tuning regulator is performed by using active and reactive power values. Moreover, the properties of the proposed methodology are compared with self-tuning PID stabilizer whose coefficients are determined by using pole assignment technique. Then, the advantages of the proposed stabilizer in which parameter adaptation is accomplished based on the proposed self tuning method by combining the pole-assignment and pole-shifting techniques, is expressed with respect to other stabilizers. Finally, in order to show the effectiveness of the proposed methodology, some simulation results on a power system with definite parameters and different operational points are provided.

In this paper, we investigate special points in which poles of the Green’s function of the D3/D7 branes are skipping. The system that we consider is SU (N c) N=4 SYM theory coupled to N_f flavors N=2 hypermultplets. We fluctuate the scalar field and find that there is no such special values of frequency and momentum to skip the poles. This behavior is different than scalar field in the AdS black brane background.

Purpose: To describe our technique and experience with retroperitoneoscopic upper pole nephroureterectomy in duplex kidney, focusing on the role of dilated upper ureter. Materials and Methods: From November 2004 to August 2011, retroperitoneoscopic upper pole nephroureterectomy was performed in 31 patients with a duplex kidney by a single, experienced laparoscopic surgeon. We developed our own surgical technique to suit this technically challenging procedure. Follow-up studies were performed using renal ultrasonography, intravenous urography (IVU) and/or dimercaptosuccinic acid (DMSA) renal scan in all patients at 3 months postoperatively and annually thereafter. Results: All procedures were completed laparoscopically without conversion to open surgery and blood transfusion. The mean operative time was 106 (90-157) min. The estimated blood loss was < 50 mL in all cases. The mean postoperative hospital stay was 4. 2 (3-7) days. Perioperative complications were limited to 1 case of peritoneal tear during a procedure and 1 case of transient postoperative fever. No major intraoperative and postoperative complication occurred. With the mean follow-up period of 41 months (range 3 to 80), no case was observed to have functional loss of the remaining lower moiety on postoperative IVU or DMSA renal scan. Conclusion: Retroperitoneoscopic upper pole nephroureterectomy using our technique is safe and effective.

Polar diagram is a generalization of Voronoi diagram in which the angle is used as the metric. This Problem has many applications in visibility, image Processing, telecommunication, antenna, and Path Planning Problems. In recent years two kinds of Polar diagram have been proposed and appropriate algorithm have been Presented for some types of sites. Also, some algorithms has presented for kinetic data and dynamic states. In this Paper, it is assumed that the Pole is moving and an algorithm is presented that updates near Pole Polar diagram of sites with moving pole efficiently and in a sub linear time. In this approach, the Preprocessing time is 〖 O(n^4 log〗 _2⁡ 〖 n)〗 and updating time for diagram with each successive movement is 〖 O(log〗 _2⁡ 〖 n +k)〗 that k is the number of sites in region T which its site’ s regions may be changed.

In this paper, a novel method to design and optimization of a 1.5 kW, 4-pole, 36-slot salient-pole permanent magnet synchronous machine (SPPMSM) based on a three-step skewed pole shoe method to reduce the output torque ripple and the cogging torque is investigated. In the first step, an initial model of the SPPMSM is designed, simulated, and verified through the Finite-Element method (FEM). The simulation results ensure the electromagnetic performance of the initial model of the machine under any operating conditions. Next, a novel method to re-design and optimize the SPPMSM based on a three-step skewed pole shoe shape is presented.. The significant results obtained from the optimized model of the SPPMSM are as: The output average torque and the air gap flux density are increased approximately by 12.65% and 3.33%, respectively compared to the initial design of the SPPMSM. The torque ripple is an important parameter in the design of the machine, and so, is decreased by about 16.03% which is equal to 10.41% in comparison with the initial model which is equal to 12.41%. The cogging torque in the initial model of the SPPMSM is equal to 0.036 N.m and with a 19.44% reduction, in the optimized model, it is 0.029 N.m. And finally, the back-EMF voltage of the SPPMSM is improved by 1.27% compared to the initial design model.

Producion of efficient antimicrobial drugs against to common human pathogens is one of the most important challenges in the field of medical microbiology. Continuous screening of clinical isolates and survey of antimicrobial resistance pattern is critical.Today, disk diffusion and dilution methods are known as the common antimicrobial susceptibility testing methods. Disk diffusion method does not render dependable results in determination of antimicrobial susceptibility pattern because this method is semi quantitative. MIC determination by microdilution and macrodilution techniques and recent method “E-Test”, have given interpretable results to researchers. Microdilution and macrodilution methods are also time consuming, expensive and error- prone methods. Whereas E-Test method is one of the means by which we will be able to determine susceptibility pattern of known species in low cost and short time. In this survey, constructing and printing of E-Test, coating of antibiotic on O.H.P film and quality control of constructed E-Tests were performed according to M7 A7 CLSI Standard. In this study quality of required materials for E-Test Production were suitable. Evaluation of constructed strips was performed using standard strain of staphylococcus aureus and reproducibly of results was appreciated.