Sharif Digital Repository

Winding configuration is a crucial factor that highly affects the accuracy of resolvers. A nonoptimal winding could also make the manufacturing process complicated and costly inefficient. In this article, an approach to determine the optimal winding configuration for the resolvers is proposed. This method is applicable for both wound rotor (WR) and variable reluctance (VR) resolvers, and significantly simplifies the winding configuration of resolvers with different pole pairs and teeth numbers. Based on the proposed approach, the winding configuration of multiturn resolvers, which are generally more complicated than single-turn resolvers, is simplified for WR and VR type resolver with... 

In this study by using a Cylindrical Capacitive Sensor (CCS), the Electrical Conductivity (EC), effects on the capacitance measurements of the water liquids was investigated. Theoretical values of the capacitance measurements of water liquids with the cylindrical length in the range 0.5-5 cm are calculated. Our obtained results indicate that measured capacitance value by CCS depends on the liquid capacitance and reactance capacitance. Liquid capacitance value of the distilled water for permittivity of 80 is about 33.5 pF and reactance capacitance value is about 0.290 μF, when the cylindrical length value is about 1.6 cm. The reactance capacitance for the mineral, tap and dilute salt water... 

In this study, a numerical finite difference model of self-boring pressuremeter test (SBPM) is performed. Limit pressure is believed to be a key parameter for estimation of soil parameters from pressuremeter tests, however; self-boring pressuremeter tests are practically conducted up to 10-15% strains, so determination of limit pressure usually needs extrapolation. For an alternative solution, it is recommended to consider cavity pressure corresponding to 10% strain (P10) for interpretation of soil parameters instead of limit pressure; therefore, more than 5000 numerical analyses of SBPM are carried out to correlate cavity pressure corresponding to 10% strain (P10) to sand parameters with... 

Monitoring embankment dams is of crucial importance. In earth dams, the pore pressures, earth pressures, and displacements occurring during construction and function are measured at the time of the first impounding and exploitation by installing essential instruments, and so the dam's performance is evaluated and analyzed. Scope of the present research is the evaluation of Siah-Sang Dam performance through the results of instruments and back analysis, conducted by FLAC software. The Mohr-Coulomb elasticplastic model has been considered as the behavioral model of the dam, and the effect of the upstream shell's materials deformation has been modeled at the time of the initial impounding.... 

Undoubtedly, microfluidics has been a focal point of interdisciplinary science during the last two decades, resulting in many developments in this area. Centrifugal microfluidic platforms have good potential for use in point-of-care devices because they take advantage of some intrinsic forces, most notably centrifugal force, which obviates the need to any external driving forces. Herein, we introduce a newly designed detection chamber for use on microfluidic discs that can be employed as an absorbance readout step in cases where the final solution has a very low viscosity and surface tension. In such situations, our chamber easily eliminates the air bubbles from the final solution without... 

The effects of different parameters including membrane type (regenerated cellulose and polysulphone), transmembrane pressure (TMP), the content of oil in the feed, the flow velocity of the feed and pH on the ultrafiltration of an emulsion of kerosene in water were studied. It was found that the important factors affecting ultrafiltration were, in order, membrane type, pressure and oil concentration. The greatest flux at the optimum conditions here of 3 bar, an oil content of 3% (v/v) and with membrane type C30F was predicted as 108 L/(m2 h) that was within the range of the confidence limit of the measured value of 106 L/(m2 h). The normalised FTIR results of the virgin cellulosic membranes...