Current Issue : April-June Volume : 2022 Issue Number : 2 Articles : 5 Articles
In this paper, the reliability analysis and residual life assessment model of gas pipelines with multiple corrosion pits are established. Aiming at the simulation evaluation of small failure probability of gas pipelines, a new method for reliability analysis and residual life assessment of gas pipelines with multiple internal corrosion pits is proposed, which is called the Hamiltonian Monte Carlo subset simulation (HMC-SS) method. Compared with the traditional MCS (Monte Carlo simulation) algorithm, the HMC-SS method has the advantages of less sampling, low cost, and high accuracy. And compared with the random walk SS method, the HMC-SS method can analyze the state space more efficiently and achieve faster convergence. In this paper, the HMC-SS method is applied to the reliability analysis and residual life assessment of gas pipeline engineering, and the sensitivity analysis of the random parameters affecting the failure probability of the pipeline is carried out. 'e results show that the corrosion rate, the depth of corrosion defects, and the wall thickness of the pipeline have great influence on the residual life of the pipeline, while the yield strength, working pressure, and the length of corrosion pits have no obvious influence on the failure probability and residual life of the pipeline. 'e analysis shows that the proposed HMC-SS method can be used as a reasonable tool for failure assessment of natural gas pipelines affected by corrosion to determine the remaining life of the pipeline system. 'is method provides a reliable theoretical basis for the integrity management of the gas pipeline....
Photovoltaic systems are a technology for the generation of electrical energy that is constantly increasing thanks to current technological advances and that contributes to sustainable development. The main stages of photovoltaic systems are the conversion stage, using an inverter, and filtering. These systems may be considered as a mature and growing technology; however, regarding its reliability, there exists some uncertainties, and they are related to the operation, incidents, and its potential failures, due to the number of elements, the environment, and the operating nominal values. For this reason, this article presents a comparative analysis of the reliability of single-phase transformerless photovoltaic inverters used to inject active power into the grid. This evaluation is carried out under the same design specifications for all the inverters analyzed; the study is made using a mission profile considering the IEC TR 62380 standard, where the events and environmental operating conditions are defined, and numerical simulations. This work is aimed at providing suggestions to improve the quality of the photovoltaic system also considering reliability....
The objective of this study is to assess the quality of the artesian borehole water consumed by the population of the village of Dogbo Ahomey in order to prevent pathologies on the populations. Methodology and Results: The household surveys were supplemented by a campaign to analyze the water samples in the laboratory. The samples were analyzed according to the standardized methods of the American Public Health Association (APHAAWWA-WPCF, 1994). A total of twenty (20) physico-chemical parameters and four (04) microbiological parameters were used to assess the quality of the different water samples. The results of the physico-chemical analysis showed that the water samples studied present values that are below the standards recommended by the WHO and by the Beninese standards for the quality of drinking water (Standards, 2001). From a microbiological analysis point of view, of the four samples studied, two show strong pollution by germs. This could be a significant health risk for households who take water from these sources to meet their needs....
Electrical equipment and supply cables demand a better quality of supply, with the recent advancements in integrated sensitive solid-state controls. Divergently, proliferated heavy inductive motors and some performance additions based on power electronics have introduced power quality issues to the network. 'us, this study mainly investigates the impact of switching transients generated by electromechanical machines in industrial power systems on insulation deterioration while taking transient overvoltages due to capacitor bank switching also to support. Transients with a high rate of rise are likely to catalyze the degradation of the insulation quality and break down the insulating material through ionization. 'ese steeply passing overvoltage stresses let partial discharges ensue, which can attack the insulation over long service. To unveil this danger, 314 common-mode transient waveforms were measured in the electrical machines of five tea factories in Sri Lanka, in a 50 ms measurement window, taken in 55 measuring attempts. Most of the transients observed are in the form of a damped oscillatory waveform tailed by fast exponential collapse. 'at correlates to insulation degradation having a very steep rise as 30.04 V/ns, the highest at the withering section. When machines are heavily loaded, situations tend to generate transients with high amplitudes. 'ere were transient bursts that spread as 426.3 ms, while 14 ns fast rise times were recorded from withering motors. Unlike electrical resonance and power-frequency overvoltages, electromagnetic switching transients last even less than 100 ms. To underline this, an analysis of the frequency domain of transients was also presented, which proves high density of high-frequency components reaching 107 kHz range. Accepting the fact that frequency and amplitude are always under the influences of innumerable dynamics, the observational evidence of the study endorses that electrical stress built by the transient nature of the factories reduces the life expectancy of electrical insulation....
An integrated-circuit testing model (DITM) is used to describe various factors that affect test yield during a test process. We used a probability distribution model to evaluate test yield and quality and introduced a threshold test and a guardband test. As a result of the development speed of the semiconductor manufacturing industry in the future being unpredictable, we use electrical properties of existing products and the current manufacturing technology to estimate future product-distribution trends. In the development of very-large-scale integration (VLSI) testing, the progress of testing technology is very slow. To improve product testing yield and quality, we change the test method and propose an unbalanced-test method, leading to improvements in test results. The calculation using our proposed model and data estimated by the product published by the IEEE International Roadmap for Devices and Systems (IRDS, 2017) proves that the proposed unbalanced-test method can greatly improve test yield and quality and achieve the goal of highquality, near-zero-defect products....
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