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This paper presents a fuzzy search controller approach along with the look-up tables, to optimize the efficiency of a pump-induction motor drive. The induction motor and the converter are modeled based on thermal loss; and for modeling the pump and the hydraulic system, which are non-linear and relatively complicated, the neural network is used. In the designed system, in order to optimize the efficiency of the pump and the hydraulic system, the amount of outflow is controlled by adjusting the pump’s rotating speed. Meanwhile by choosing the suitable switching frequency of the inverter and feeding the motor by proper amount of voltage and frequency, the loss amount of the drive system is minimized. Simulation results show that the proposed controller improving the efficiency of the drive system under flow-changing conditions, as well as it has improved the problems that existed in some of the classical efficiency optimization approaches, such as the slowness of the converging, and the oscillation around the optimal point.

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Aims: Chlamydial infections could lead to ectopic pregnancy and infertility. Considering the high prevalence of infertility in Iran and little information about the role of urogenital bacterial infections in this disease, this study aimed to evaluate the prevalence and sequence types of Chlamydia trachomatis in the urogenital tract of infertile couples in North Khorasan.
Materials & Methods: Cervical or urethral swabs collected from infertile patients referring to two private clinics and the infertility center of Bent Al-Hoda hospital in Bojnurd during 2017-2021 were tested for C. trachomatis. These specimens were evaluated using PCR for C. trachomatis orf8 gene. Multi-locus sequence typing (MLST) was performed on positive samples using PCR amplification of seven housekeeping genes (GlyA, leuS, lysS, mdhC, pdhA, pykF, and yhbG) following a previously described protocol.
Findings. Out of 268 samples tested, 44 (16.4%) samples were positive for C. trachomatis. Among which, 35 cases were obtained from women, and nine samples were from men. Of the 44 positive samples, 10 cases were not typable. Only two sequence types were detected among 34 typeable isolates: 25 (73.5%) isolates belonged to ST80, and nine (26.5%) samples belonged to ST4.
Conclusion. The high prevalence of ST4 and ST80 in most symptomatic infertile patients may be attributed to the higher pathogenicity of these types in the urogenital tract. However, our sample size was insufficient to draw such a conclusion.,  Further research on the prevention and treatment of Chlamydial infections could potentially help to reduce infertility in Iran.
 

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Objectives: Staphylococcus aureus is an important cause of serious infection in both hospital and the community. Methicillin-resistant S. aureus (MRSA) is associated with high morbidity and mortality rates with rapid development of resistance. There is a need for early and reliable detection of MRSA infection to direct antibiotic therapy, and more effectively control cross-infection. In this study, resistance to methicillin was detected by a disk diffusion method, the determination of MIC, and the PCR for mecA gene. Materials and Methods: A total of 174 S.aureus strains were isolated from different clinical specimens from three teaching Hospitals. Antibiotic susceptibility was determined by disk diffusion method, MIC for oxacillin was made by the agar dilution, and mecA gene was identified by specific primers. Results: The prevalence of MRSA by three methods ranged from 47% to 50%, and mecA positive isolates were more resistant to all of the antibiotic tested than mecA negative isolates. All S. aureus isolates were resistant to penicillin, and susceptible to vancomycin. The results of agar dilution test indicated a low-level resistance to methicillin (MIC>64mg/l). The distribution of MRSA isolates were uniform between three hospitals, and there were not significant differences in the presence of MRSA between isolates from different clinical specimens. Conclusion: The PCR method was the best test for routine detection of MRSA in the present study. An additional benefit of the mecA PCR is the potential to generate a susceptibility report, 24h earlier than the time of generation of results of conventional susceptibility testing methods.

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Fluid flow through channels and ducts in nano scales is an important issue which needs numerical simulations for better analysis of fluid behavior because of the limitations of experimental methods. Hence, in the present study Molecular Dynamics simulation is used as a precise method for molecular scale problems to investigate fluid behavior. This method which is based on Newton’s second law, is applied to investigate liquid Argon flow in steady Couette flows through smooth and rough nanochannels. Using LAMMPS software, were performed simulation. In the present study, the fluid velocity and fluid slip in steady Couette flows were obtained to investigate various effects including: wall velocity, channel height, wall density, fluid-wall interaction, and surface roughness with different shapes such as rectangular and triangular in different dimensions. Based on the results, an increase in wall velocity increases the fluid slip velocity. For velocity constant values, an increase of channel height will decrease the fluid slip velocity. In steady Couette flow, decrease of wall density will result in decrease of fluid slip velocity. Reducing the energy parameter between fluid and wall will increase the fluid slip velocity and on the other hand, decreasing the fluid-wall length parameter will decrease the fluid slip velocity. The rectangular and triangular roughness at the bottom wall reduces the fluid slip velocity, and an increase of roughness height will further decrease the fluid slip velocity.

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Thermal creep is often associated with the flowing of a rarefied gas via the effect of temperature difference in solid boundaries. Recently the feasibility of such flow in dense fluids becomes a challenge. This paper deals with simulating the thermal creep flow in liquids confined in nanotubes. The investigations are carried on by molecular dynamics simulation method. The goal of this work is providing a clean picture of the thermal creep phenomenon mechanism in liquids. Simulation results show the existence of such flow in liquids in nanotubes. The thermal creep effect is stronger in nanotubes with narrower cross sections. Molecular data provided by the simulations shows there is a fluid layering phenomenon near the solid wall. The fluid layering together with the wall temperature gradient develops a pressure gradient near the wall. This pressure gradient acts as a planar force and is assumed to be responsible for the thermal creep effect. This force causes the fluid to flow toward the hot side of the tube. The mechanism of thermal creep phenomena is justified by the use of molecular principles and molecular data which are obtained from the molecular dynamics simulations.

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In this paper, the results obtained from experimental measurements of average and turbulence quantities of a turbulent rectangular impinging jet hitting a fixed wall is reported using the laser doppler anemometry (LDA) method. The nozzle to plate distance is 10 times the nozzle width, and the tests are repeated for three different Reynolds numbers, namely Re=3000, 6000 and 9000. The aim of the current research was to investigate and comparise of flow in different Re and also to determine the two effective experimental errors on average velocities, namely data sampling and residence time in measurement volume. The results reveal that the previous stated correlation for prediction of the number of data required for ensuring independence of the average flow variables on the number of the sampled data is not sufficient by itself, and depending on the turbulence intensity of the flow, this correlation could become ineffective. Further, in the present study, the residence time is used for calculation of average velocities, and the results are compared with those obtained by particle image velocimetry (PIV) method. The comparison shows good agreement between the results from LDA and PIV when considering effect of residence time within the avaraging equations in the former method. The results show that the behavior and quantity of the dimensionless average velocities for various Reynolds numbers are identical at most cross sections of the flow domain while the dimensionless turbulent stresses have different quantities at different values of the Reynolds number.