Power-Efficient Hybrid Energy Storage System for Seismic NodesRead the full article
Journal of Engineering publishes research in several areas of engineering, including chemical engineering, civil engineering, computer engineering, electrical engineering, industrial engineering and mechanical engineering.
Chief Editor, Professor Wang, is the Vice Deputy Dean of the School of Aerospace Engineering at Tsinghua University.
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A New Empirical Correlation for Estimation of EBF Steel Frame Behavior Factor under Near-Fault Earthquakes Using the Genetic Algorithm
The most important feature of the behavior factor is that it allows the structural designer to be able to evaluate the structural seismic demand, using an elastic analysis, based on force-based principles quickly. In most seismic codes, this coefficient is merely dependent on the type of lateral resistance system and is introduced with a fixed number. However, there is a relationship between the behavior factor, ductility (performance level), structural geometric properties, and type of earthquake (near and far). In this paper, a new and accurate correlation is attempted to predict the behavior factor (q) of EBF steel frames, under near-fault earthquakes, using the genetic algorithm (GA). For this purpose, a databank consisting of 12960 data is created. To establish different geometrical properties of models, 3−, 6−, 9−, 12−, 15, and 20− story steel EBF frames were considered with 3 different types of link beam, 3 different types of column stiffness, and 3 different types of brace slenderness. Using nonlinear time history under 20 near-fault earthquake, all models were analyzed to reach 4 different performance levels. 6769 data were used as GA training data. Moreover, to validate the correlation, 2257 data were used as test data for calculating mean squared error (MSE) and correlation coefficient (R) between the predicted values of (q) and the real values. In addition, the MSE and R were calculated for correlation in the train and test data. Also, the comparison of the response of maximum inelastic displacement of 5 stories EBF from the proposed correlation and the mean inelastic time-history analysis confirms the accuracy of the estimate relationship.
The Practical Influence of Climate Change on the Performance of Road Stormwater Drainage Infrastructure
The atmospheric temperature globally has risen during the last few centuries, causing global warming and climate dynamics. The impact of global warming has caused environmental effects that include increased rainfall intensity, which is recognised as the leading cause of flooding, and destruction and devastation to the surrounding environment, infrastructure, and human life. Road stormwater drainage systems are used for removing and controlling excess runoff water to the right way. However, regardless of enhanced technologies, the reliability of drainage system schemes remains a major undertaking for water and hydraulic engineers alike. In this study, a thorough evaluation of the methods employed in previous studies and research on rainfall forecasting models was undertaken. Further to that, the effect resulting from climate change on structures of drainage infrastructure is considered in addition to the methods to enhance drainage system challenges with recent models developed for advanced drainage and waterway requirements that need to be designed in consideration of climate change.
Design and Fabrication of a Plastic Biogas Digester for the Production of Biogas from Cow Dung
Biogas digester dimensions and materials of construction are important factors of consideration during the design and fabrication phase. The aim of this study is to provide a detailed analysis of the design and fabrication of a 2.15 m3 pilot plastic biogas digester for biogas generation. To establish this, a design equation covering the volume of the digester, inlet and outlet chambers, and digester cover plate were developed considering the shape of the digester. The digestion chamber of the biogas digester under study was fabricated using high-density polyethylene (HDPE) plastic, while the inlet and outlet chambers were constructed with bricks/cement. The study was motivated due to some limitations such as leakage associated with previous designs. In the present study, a ventilation test was conducted after the fabrication to ensure the digester is leak free. Results obtained showed a total volumetric methane gas yield of 2.18 m3 (54.50%) and carbon dioxide yield of 1.77 m3 (44.25%) making up a total biogas yield of 4.00 m3. In addition, the percentage concentration of methane and carbon dioxide were found to be 60% and 30%, respectively. The developed plastic biogas digester has been found to be appropriate for biogas production using cow dung as substrate.
CFG Pile Composite Foundation: Its Engineering Applications and Research Advances
Problematic soils exist almost everywhere on the globe. State-of-the-art solutions to make civil engineering infrastructures built on them are still highly sought. The CFG (cement-fly ash-gravel) pile composite foundation system has been widely used in buildings, highways, railways, and bridge transition sections owing to its proven engineering characteristics in soft ground treatment. This paper discusses about the development and achievements of its engineering applications, along with possible future research directions. The remarkable evolution took place in the past to address projects’ strict differential and postconstruction settlement control requirements including embedding the geosynthetic layer into the load transfer platform and combining it with rigid slabs, as seen implemented in few CFG pile-supported embankments. It was also observed that the interaction of the existing CFG pile composite foundation with an adjacent new foundation pit excavation inevitably presents a complex soil-structure interaction mechanism among the fundamental components—the retaining wall, mat, piles, cushion, and soil.
Performance Indicators for Spare Parts and Maintenance Management: An Analytical Study
A properly implemented maintenance management system has an impact at different levels. Maintenance is defined as the set of actions to maintain a property in a specified state. The unavailability of the spare parts required, to carry out the maintenance intervention, causes an extension of the inactivity time of the installation. On the contrary, an excessive stock of spare parts confines enormous capital and entails an enormous cost of ownership. According to the literature already made, we have directed in our work to propose a model of joint management of maintenance and spare parts based on stochastic-deterministic batch Petri networks. We studied this model by simulation using a graphical interface dedicated to the graphical tool used. So, we present, in this paper, the analytical study of the model by defining the performance indicators and viewing the influence of system parameters on these indicators. The main stages of the analytical study are developing the μ-marking graph, the associated Markov process which gives the associated transition matrix, and the definition of performance indicators using the probability distribution of the states. We deal with an application of the analytical evaluation of the proposed model. We end this article with an analysis and synthesis.
Method for Evaluating the Effect of the Design and the Environmental Conditions of the Manufacturing Cells toImprove Work Performance
A method is proposed to improve work performance through an adequate design of the manufacturing cell along with optimal environmental conditions to contribute to the well-being of the worker. The methodology used was divided into four stages: the first corresponds to the analysis of operations; the second is the analysis of the effect of the design of the manufacturing cell; the third is the evaluation of environmental conditions such as lighting, noise, and temperature to compare them with the official standard and determine if they meet the permitted levels; and the fourth is to conclude and recommend improvements to the manufacturing cell. The method was applied in a company in the automotive industry, where a change was made from a linear cell distribution to an L-shaped distribution, with a 50% reduction in workforce and an increase in the productive time of the worker of 49%. Also, the environmental conditions of the cell comply with the requirements of official standards.