This article proposed a novel topology of dynamic voltage regulator using transformer and PWM multi-level AC/AC converter. In this paper for finding the best value of duty ratio for switches to minimize the THD, the GA algorithm has been used and THD output voltage is assumed to be fitness function. The proposed voltage regulator employs multi-level AC/AC converter to generate compensation volt...

A novel design and facile synthesis process for carbon based hybrid materials, i.e., cobalt monoxide (CoO)-doped graphitic porous carbon microspheres (Co-GPCMs), have been developed. With the synthesis strategy, the mixture of cobalt gluconate, α-cyclodextrin and poly (ethylene oxide)₁₀₆-poly (propylene oxide)₇₀-poly (ethylene oxide)₁₀₆ is treated hydrothermally, followed by pyrolysis in argon....

Pulsewidth modulated (PWM) current-source rectifiers (CSR), among other alternatives, offer marked improvements over thyristor line-commutated rectifiers as a source of variable dc power. Advantages include reduced line current harmonic distortion and complete displacement power factor control, including unity displacement power factor operation. However, due to nonlinearities of the PWM-CSR mo...

By minimizing the total potential energy function and deploying the virtual work principle, a higher-order stiffness matrix is achieved. This new tangent stiffness matrix is used to solve the frame with geometric nonlinear behavior. Since authors’ formulation takes into account the higher-order terms of the strain vector, the convergence speed of the solution process will increase. In fac...

We investigated how varying the x-ray tube voltage and image receptor input exposure affected image quality and patient radiation doses in interventional neuroradiologic imaging. Digital subtraction angiography (DSA) images were obtained of a phantom with 1 mm diameter vessels containing iodine at concentrations between 4.5 and 50 mg/cc. The detection threshold concentration of iodine was deter...

The LVRT (Low Voltage Ride Through) is the main characteristic of every power system in faulty conditions. When fault occurs, it is essential for power system such as microgrid to control the voltage and frequency normally. Naturally in fault status, the unbalanced voltage and current are inevitable, but with the aid of LVRT technique, microgrid can keep stability in main system parameters such...

We have built a vertical seismometer that works based on the moiré technique. One grating is attached to the suspended mass and one to the frame of the instrument. The two gratings are in relative motion, and the resulting moiré pattern magnifies this motion. The intensity of a light beam passing through the moving moiré fringes changes with time, and a light detecting syst...