Accurate calculation of transient overvoltages and dielectric stresses from fast-front excitations is required to obtain an optimal dielectric design of power components subjected to these conditions, which are commonly due to switching and lightning, as well as utilization of power-electronic devices. Toroidal transformers are generally used at the low voltage level. However, recent investigations and developments have explored their use at the medium voltage level. This paper analyzes the model-based improvement of the insulation design of medium voltage toroidal transformers. Lumped and distributed parameter models are used and compared to predict the transient response and dielectric stress along the transformer winding. The parameters of the toroidal transformer are computed using the finite element method considering a three-dimensional geometry. Different strategies for insulation design are proposed by means of optimal insulation thickness and electrostatic shield to reduce transient overvoltage and dielectric stress. The results show that the proposed optimal insulation design based on particle swarm optimization with electrostatic shield can substantially reduce the dielectric stress and dielectric distances. Comparison between simulations and experimental results demonstrates that the frequency domain modeling approach results in accurate calculation of transient overvoltages produced by fast front excitation and can be used effectively for insulation design.
The international standing has an impact on the strategic importance of the country in its relations with other regional and international countries. The strategic position of Taiwan has an impact on the US-Chinese relations, as it is one of the most important issues that raise dispute between the two countries. The while the Chinese consider Taiwan is an ancient legacy of their republic, and an integral part of it, the Americans consider it as an area linking the U.S. to the Asia-Pacific region, through which it intends to help its allies (Japan and South Korea). Moreover, Taiwan has huge economic importance as it is one of the largest manufacturers of electronic chips and semiconductors. This fact represents one of the most important issu
... Show MoreThe growth curves of the children are the most commonly used tools to assess the general welfare of society. Particularity child being one of the pillars to develop society; through these tools, we can path a child's growth physiology. The Centile line is of the important tools to build these curves, which give an accurate interpretation of the information society, also respond with illustration variable age. To build standard growth curves for BMI, we use BMI as an index. LMSP method used for finding the Centile line which depends on four curves represents Median, Coefficient of Variation, Skews, and Kurtosis. These can be obtained by modeling four parameters as nonparametric Smoothing functions for the illustration variable. Ma
... Show MoreThe present study aimed to assess the impact of seed Rhizobia treatment and potyvirus inoculation on bacterial nodulation and nitrogen fixation in cowpeas. The plants were infected with the virus two weeks post-germination. Nodules were present on the roots of plants treated with Rhizobia; however, almost no nodules were detected on untreated plants. The average number of nodules per plant on virus-inoculated plants was significantly lower than the average number per noninoculated plant. The virus caused a substantial decrease in the weight of nodules also. The study revealed that the presence of Rhizobia resulted in a significant rise in nitrogen content in the foliage. Specifically, the nitrogen percentage increased from 1.29% in plants n
... Show MoreThis study is directed at investigating the liquefaction potential within earth dams using numerical modelling by two-dimensional finite element analyses method for considering the Makhool earth dam on the Tigris River in Iraq. The effect of peak ground acceleration of 0.02g, 0.04g, 0.06g, and 0.08g is viewed for a shell, and the crest is presented for all scaled earthquake duration 25 s, 50 s, 75 s, and 100 s. The current study program comprises selecting a representative history point within the Makhool earth dam as a case study. Many points were allocated at different locations within the shell and crest to observe the fluctuation in the factor of safety against liquefaction. The seepage analysis results viewed graphically for the operat
... Show MoreThe aim of this study is to provide an overview of various models to study drug diffusion for a sustained period into and within the human body. Emphasized the mathematical compartment models using fractional derivative (Caputo model) approach to investigate the change in sustained drug concentration in different compartments of the human body system through the oral route or the intravenous route. Law of mass action, first-order kinetics, and Fick's perfusion principle were used to develop mathematical compartment models representing sustained drug diffusion throughout the human body. To adequately predict the sustained drug diffusion into various compartments of the human body, consider fractional derivative (Caputo model) to investiga
... Show MoreActive worms have posed a major security threat to the Internet, and many research efforts have focused on them. This paper is interested in internet worm that spreads via TCP, which accounts for the majority of internet traffic. It presents an approach that use a hybrid solution between two detection algorithms: behavior base detection and signature base detection to have the features of each of them. The aim of this study is to have a good solution of detecting worm and stealthy worm with the feature of the speed. This proposal was designed in distributed collaborative scheme based on the small-world network model to effectively improve the system performance.
Over the last few years, the interior designer has been given the ability to access many innovative tools for new forms of unprecedented diversity and efficiency. Some design experts have described the new parametric procedures they are introducing to create new interior projects as a radical transformation that carries all the elements of a qualitative shift in interior design. The best of these parametric procedures is the technical capabilities offered by us to create new forms that are different from what has been discussed in everything that has been produced by designers and architects since modernity and even before it to the present time, which returns our design products through a series of computer programs that perform the pro
... Show MoreThis research has discussed the origins of ESP, addressed key notions about ESP and examined issues in ESP syllabus design. The content of the paper was determined by a need identified based on my experience as an ESL instructor designing and delivering the content-based language program - Language Preparation for the Cadets and Employment in the Iraqi College of Police . These issues, where possible, have been supported by current and pertinent academic literature. It is my sincerest hope that these observations will lend insight into the challenges facing the ESL instructor acting as ESP syllabus developer.
The current research dealt with the rapid development of industrial product design in recent times, and this development in the field of design led to the emergence of modern trends in many terms and theories to direct greater interest in the cognitive foundations of design and its relationship with the components of other natural sciences, and despite the impressive technological development, nature remains With its content of formative values and structural dimensions, it is the first source of inspiration and the source of all modern mathematical sciences and theories, as God made them tend towards organization to continue to provide us with endless inspiration. Hence, the fractional one, which is an important part of dedicating the d
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