Optimization Of Thermal Module Solar Photovoltaic Using CFD-Simulation

Photovoltaic panels can directly generate electricity by converting solar energy, but the panels temperature reduce the efficiency of photovoltaic cells. The photovoltaic thermal PVT system technology is used to improve the electrical performance. In this study, the daily and monthly global solar radiation on a horizontal surface for Iraq have been measured and presented then used with PVT water system. ANSYS software is used to simulate the water temperature differences behavior and measure the surface temperature of PVT model using the collected irradiation with the mass flow rate at 0.01 and 0.02 kg per second. The CFID results were validated with previous studies and observed a good agreement. The simulation tests apply a constant input temperature to the PVT system in all the yearly weather conditions in order to enhance the surface temperature. The results observe the PVT thermal efficiency behavior and show the maximum enhancement which is reached to 61% with the mass flowrate 0.03 kg per second and constant low input temperature.

A New Dual Polarity Direct AC-AC Voltage Regulator Ensuring Voltage Step-Up and Step-Down Capabilities

The problem of voltage sag and swell is one of the major reasons for low-quality power in the distribution system. Normally, it results from the system’s faults, including line-to-ground and line-to-line, non-linear characteristics of loads and sources. Its effect is very serious for the critical loads as their performance is very sensitive to the variation in voltage. The stabilization of voltage is a mandatory requirement in such a situation. The correction of such problems requires the addition and subtraction of the voltage once the line voltage is decreased and increased. This behavior of the correcting voltage is ensured by the use of voltage controllers that can convert a constant input voltage into a non-inverted and inverted variable form. Their voltage gains depend on the depth level of the problem. The voltage buck and boost capabilities of the AC voltage stabilizers can tackle the problems having any depth level. The smartness of such a system depends on the number of electronic devices as they are the key elements in the power conversion system. Therefore, this research proposes a new AC voltage controller with fewer solid-state devices. Its overall impact is low volume and cost. The validation of the introduced approach is ensured with the help of simulation modeling and results gained from the practical setup.

A Secure Recommendation System for Providing Context-Aware Physical Activity Classification for Users

Advances in Wireless Body Area Networks, where embedded accelerometers, gyroscopes, and other sensors empower users to track real-time health data continuously, have made it easier for users to follow a healthier lifestyle. Various other apps have been intended to choose suitable physical exercise, depending on the current healthcare environment. A Mobile Application (Mobile App) based recommendation system is a technology that allows users to select an apt activity that might suit their preferences. However, most of the current applications require constant input from end-users and struggle to include those who have hectic schedules or are not dedicated and self-motivated. This research introduces a methodology that uses a “Selective Cluster Cube” recommender system to intelligently monitor and classify user behavior by collecting accelerometer data and synchronizing with its calendar. We suggest customized daily workouts based on historical user and related user habits, interests, physical status, and accessibility. Simultaneously, the exposure of customer requirements to the server is also a significant concern. Developing privacy-preserving protocols with basic cryptographic techniques (e.g., protected multi-party computing or HE) is a standard solution to address privacy issues, but in combination with state-of-the-art advising frameworks, it frequently provides far-reaching solutions. This paper proposes a novel framework, a Privacy Protected Recommendation System (PRIPRO), that employs HE for securing private user data. The PRIPRO model is compared for accuracy and robustness using standard evaluation parameters against three datasets.

Analysis of loss on single-phase dry transformers with non-linear load

The paper studies power losses in transformers due to non-linear loads. The research aims to analyze the power loss in a single-phase dry transformer under a non-linear load. The research uses an SW43W Power supply type, FlukeView Power Quality Analyzer as a DC or AC power supply on the primary side of the transformer. The non-linear load is connected to the secondary side. The loading test of the dry transformer was carried out at non-linear loads. The load variations used 0 %; 12.5 %; 25 %; 37.5 %; 50 %; 62.5 %; 75 %; 87.5 % and 100 %, as well as variations in the THD value by adjusting the ignition angle (α). The non-linear loads used are Half-Wave Rectifier and Controlled Half-Wave Rectifier with resistive loads with variations in THD values. The results showed that the transformer losses comprised Pno load and Pload. The operation of the transformer with constant input voltage and frequency with THDv<5 % resulted in a constant Pno load value at all load values. The greater the percentage of the load, the higher the load. The increase in THD because of non-linear load will increase the load on the transformer. The value of the derating factor is obtained by connecting the increase in losses (∆PLosses), which is influenced by THD and the increase in temperature T(°C) in dry transformers. When the transformer is loaded with a non-linear load, the derating factor<1. THD and derating factor form a linear relationship, when THD increases, the derating factor value decreases. Linear load on the transformer causes a decrease in its capacity, but if it gets a non-linear load with THD=39.1 %, it can withstand a load of 84.294 %, besides the increase in total harmonic distortion will increase losses and reduce transformer capacity

Mathematical modelling of oscillating patterns for chronic autoimmune diseases

Many autoimmune diseases are chronic in nature, so that in general patients experience periods of recurrence and remission of the symptoms characterizing their specific autoimmune ailment. In order to describe this very important feature of autoimmunity, we construct a mathematical model of kinetic type describing the immune system cellular interactions in the context of autoimmunity exhibiting recurrent dynamics. The model equations constitute a non-linear system of integro-differential equations with quadratic terms that describe the interactions between self-antigen presenting cells, self-reactive T cells and immunosuppressive cells. We consider a constant input of self-antigen presenting cells, due to external environmental factors that are believed to trigger autoimmunity in people with predisposition for this condition. We also consider the natural death of all cell populations involved in our model, caused by their interaction with cells of the host environment. We derive the macroscopic analogue and show positivity and well-posedness of the solution, and then we study the equilibria of the corresponding dynamical system and their stability properties. By applying dynamical system theory, we prove that steady oscillations may arise due to the occurrence of a Hopf bifurcation. We perform some numerical simulations for our model, and we observe a recurrent pattern in the solutions of both the kinetic description and its macroscopic analogue, which leads us to conclude that this model is able to capture the chronic behaviour of many autoimmune diseases.

Electro-Hydraulic Proportional System Real Time Tracking Control Development Based on Pulse width Modulation Method

The presented work was directed to develop the dynamic performance of an electro-hydraulic proportional system (EHPS). A mathematical model of the EHPS is presented using electro- hydraulic proportional valve (EHPV) by Matlab-Simulink, which facilitates the simulation of the hydraulic behavior inside the main control unit. Experimental work is done and the closed loop system is designed using the linear variable displacement transducer sensor (LVDT). The controller of the system is an Arduino uno, which is considered as a processor of the system. The model is validated by the experimental system. The study also presents a real time tracking control method, based on pulse width modulation, by controlling the speed of the actuator to achieve the position tracking with minimum error and low transient time, by applying the constant input signal 50mm the transient time was 0.9 seconds and the error 1.8%.

Comparative Review on Efficient Design of Reversible Sequential Circuits based on Optimization Parameters

Reversible computing, a well known research area in the field of computer science. One of the aims of reversible computing is to design low power digital circuits that dissipates no energy to heat. The main challenge of designing reversible circuits is to optimize the parameters which make the design costly. In this paper, we review different designs of efficient reversible sequential circuits and prepare a comparative statement based on eight optimization parameters such as Quantum Cost (QC), Delay (del), Garbage Output (GO), Constant Input (CI), Gate Level (GL), Number of Gate (NoG), Type of Gate (ToG), Hardware Complexity (HC) of Circuit.

Dynamical behaviors in the FitzHugh–Nagumo system with a memory trace

In this paper, the dynamical behaviors of the FitzHugh–Nagumo (FHN) system with a memory trace, which has time-fractional derivatives, are investigated. For the case of a classical order, the constant input current can change the stability of the equilibrium point in a single FHN unit, and the equilibrium is unstable in a certain range of the current. A decrease of the order of the time-fractional derivative may lead to a linear reduction of the range and the appearance of a solution of mixed-mode oscillations, which consist of subthreshold small-amplitude oscillation and suprathreshold large-amplitude oscillation. In the parameter space of the input current and the fractional order, the region of existing the mixed-mode oscillation is linearly widened when the fractional order moves toward its small value. If a suprathreshold perturbation is periodically applied, there exist some obvious bands, on which the excited period is locked to the perturbation period according to some rational ratios. As a result, the bands can be narrowed by decreasing the value of fractional order and their location has a slight drift toward the small value of the perturbation period. In addition, the properties of solitary traveling waves and wave train solutions are also studied in the one-dimensional space. It is illustrated that the traveling pulse is wider for a smaller value of fractional order, and its velocity is larger. Further, some relations of wave trains have a great change when the value of the fractional order is changed.