In this paper, a new method for modelling and estimation of reliability parameters of power transformer components in distribution and transmission voltage levels for preventive-corrective maintenance schedule of transformers is proposed. In this method, with optimal estimation of Weibull distribution parameters using least squares method and input data uncertainty reduction, failure rate and p...

In this research, the feasibility of using mathematical modelling in the ball milling process has been evaluated to verify the hardness changes of an aluminium nanostructure. Considering the model of normal force displacement (NFD), the radius of elastic-plastic and normal displacement of two balls were computed by applying analytical modelling and coding in MATLAB. Properties of balls and alum...

Pipes are widely used in many industrial and mechanical applications and devices. Although there are many different constructions according to the specific application and device, these can show helical pattern, such as spiral pipes, wire-reinforced pipes/shells, spring-suspension, and so on. Theoretical modelling of wave propagation provides a prediction about the dynamic behavior, and it is f...

In many active noise control (ANC) applications, an online secondary path modelling method that uses a white noise as a training signal is required. This paper proposes a new feedback ANC system. Here we modified both the FxLMS and the VSS-LMS algorithms to raised noise attenuation and modelling accuracy for the overall system. The proposed algorithm stops injection of the white noise at the op...

In many active noise control (ANC) applications, an online secondary path modelling method that uses a white noise as a training signal is required. This paper proposes a new feedback ANC system. Here we modified both the FxLMS and the VSS-LMS algorithms to raised noise attenuation and modelling accuracy for the overall system. The proposed algorithm stops injection of the white noise at the op...

water desorption isotherms of raw and osmotically dehydrated (at 25ºc, for 2 hours, with 10 and 26% nacl solutions) garlic slices at different temperatures (25, 40, 55, and 70ºc) were experimentally determined over a range of water activity of 0.05–0.90 using a static gravimetric method. desorption isotherms can be classified as type iii. the water desorption isotherms of raw garlic clearly sho...

in this paper, a cfd model of syngas flow in slurry bubble column was developed. the model is based on an eulerian-eulerian approach and includes three phases: slurry of solid particles suspended in paraffin oil and syngas bubbles. numerical calculations carried out for catalyst particles, bubble coalescence and breakup included bubble-fluid drag force and interfacial area effects. also, the ef...

background: the monte carlo method is the most accurate method for simulation of radiation therapy equipment. the linear accelerators are currently the most widely used machines in radiation therapy centers. methods: in this work, a monte carlo modelling of the siemens oncor linear accelerator in 6 mv and 18 mv beams was performed. the results of simulation were validated by measurements in wat...

abstract the industrial dairy farms in iran are facing several economic problems and about six percent of these farms were shut down in fars province due to low profitability. despite such problems and availability of other enterprises in the region, farmers do not switch to other farm activities. in this context, the factors affecting acceptance of diversification options were investigated in ...