163 research outputs found

    Performance of Isolated Footing with Several Corrosion Levels under Axial Loading

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    This research aims to illustrate the corrosion process and its effect on the deterioration of reinforced concrete (RC) isolated footings using a small-scale model (1/8) and present the results of a prototype-scale study using a numerical model with different concrete depths and corrosion levels under axial load. The experimental program consisted of testing five small-scale (1/8) model RC isolated footings under axial loading after subjecting them to accelerated corrosion tests with a constant current. The main variable in the small-scale sample test was the corrosion level. This study presents an experimental approach, using the constant current method and the finite element method (FEM) with the ABAQUS package, to examine its effect on the axial load behavior under different corrosion ratios, which were 0%, 4.21%, 9.11%, 24.56%, and 30.67%. On the prototype scale, the variables were the corrosion level and the RC depths of 300 mm, 400 mm, and 500 mm. The results indicated that the average deviation in ultimate load between the experimental and FEM outcomes for the small-scale was below 5.6%, while the average deflection deviation was 6.8%. Also, the study found that an increase in the depth of the RC footing and corrosion ratio led to a more pronounced impact of the cracking pattern in the concrete and corroded bars, as well as a greater difference in the failure load. The experimental results suggest that the proposed numerical model is accurate and effective. These findings have important implications for the evaluation of isolated footings affected by corrosion damage using FEM, and can help inform decisions related to their design and maintenance. The failure loads of non-corroded footings with different depths were compared with the ECP-203 provisions of the 2018 Egyptian Code, and how corrosion ratios can be simulated by numerical models. The percentage variation between the design loads by code and the numerical loads by ABAQUS for controlled footings with thicknesses of 300, 400, and 500 mm was found to be 73%, 80%, and 78%, respectively. Using the derived relationship, the equivalent corrosion ratio percentages were 23.8%, 20.2%, and 32%, respectively. Doi: 10.28991/CEJ-2023-09-06-011 Full Text: PD

    Detection of multiple defects based on structural health monitoring of pipeline using guided waves technique

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    Monitoring and inspecting the health condition and state of the pipelines are significant processes for an early detection of any leaking or damages for avoiding disasters. Although most Non Destructive Test (NDT) techniques are able to detect and locate damage during the maintenance intervals, interrupted services could result in high cost and lots of time consumed. In addition, most NDTs are utilized to detect and locate single damage such as axial crack, circular crack, or vertical crack only. Unfortunately, these NDTs are unable to detect or localize multi-type of damages, simultaneously. In this research, the proposed method utilizes the Structural Health Monitoring (SHM) based on guided wave techniques for monitoring steel pipeline continuously in detecting and locating multi-damages. These multi damages include the circumference, hole and slopping cracks. A physical experimental works as well as numerical simulation using ANSYS were conducted to achieve the research objectives. The experimental work was performed to validate the numerical simulation. An artificial neural network was used to classify the damages into ten classes for each type of damage including circumference, hole and sloping cracks. The obtained results showed that the numerical simulation was in agreement with the experimental work with relative error of less than 1.5%. In addition, the neural network demonstrated a feasible method for classifying the damages into classes with the accuracy ranged from 75% to 82%. These results are important to provide substantial information for active condition monitoring activities

    Assessment of vehicular live load and load factors for design of short-span bridges according to the new Egyptian Code

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    AbstractThe new Egyptian Code (ECP-201:2012) introduces new vehicular live loads (VLL) and new load combinations for the design of roadway bridges. The new VLL and load combinations introduced in ECP-201:2012 are fundamentally different than those presented in previous versions of the code. The impact of these new loads and load combinations on the design of new bridges or the structural safety of the existing bridges that have been designed according to ECP-201:2003 or ECP-201:1993 has not been fully addressed for the different bridge deck systems. Three different bridge deck systems, i.e. concrete I-shaped girders, composite steel plate girders, and concrete box-girders with different spans were numerically modeled using two-dimensional grillage analogy. The bridge decks were analyzed under main gravity loads using VLL according to ECP-201:2012 and ECP-201:2003. The internal forces of individual load cases, total un-factored load combination, and total factored load combination of ECP-201:2012 and ECP-201:2003 were compared.The study shows that concrete box-girders designed according to ECP-201:2012 and ECP-201:2003 using the ultimate limit state method yield almost the same demand. Despite the increase in the VLL of ECP-201:2012, and consequently the live load forces, concrete I-shaped girder bridges will be subjected to less total factored internal forces in comparison to ECP-201:2003 This is attributed to the interaction between the live to dead loads ratio and the load combinations. Design of composite steel plate girder bridges according to ECP-201:2012 using the allowable stress design method yields over designed sections

    Highlight of Grid-connected PV systems in administrative buildings in Egypt

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    Solar energy applications are becoming increasingly common in Egypt. The abundant sunshine in Egypt, as well as the increasing competitiveness of solar energy systems including- but not limited to photovoltaic (PV), – predicts that these technologies could be weighed to be raised in Egypt.PV systems are installed on roof tiles or other parts of building structures to supplement grid utility, reduce electric bills, and provide emergency back–up energy. Moreover, they simultaneously reduce significant amounts of CO2 emissions. It is foreseen, a number of residential and public buildings in Egypt are using solar power to cut electric utility bills significantly. The approximately payback period to recover the investment costs for PV systems is up to about 5 years.  In addition, it is more economical to use PV system than grid utility systems. The two components that determine the total initial price of a grid- connected PV system are the modules and the balance of systems (BOS). The BOS includes different components such as mounting frames, inverters and site- specific installation hardware.The Government of Egypt (GOE) has endorsed the deployment of PV systems through three approaches. It started with a prime minister decree to install PV projects on one-thousand of the governmental buildings. This was followed by as an initiative called "Shamsk ya Masr", and finally the Feed-in Tariff (FiT) projects.Following the prime minster decree the Egyptian Electricity Holding Company (EEHC) and its affiliated companies took the lead to install PV systems at the top roof of their administrative buildings and interconnect these systems to the electricity network where the suitable locations have been selected for mounting them. About 90 PV systems have been already mounted with about a capacity of 9 MW. On the other hand, "Shamsk ya Masr" has considered energy efficiency (EE) so as to complement the PV systems, which will be installed on administrative buildings. Cost- effective EE measures should be implemented prior to or at the same time as implemented PV program. The amount of electricity that a PV system produces depends on the system type, orientation and the available solar resource. In 2014, the GOE issued the Feed-in Tariff program to further promote RE technologies in general and PV in particular. Egyptian Electric Utility and Consumer Protection Regulatory Authority (Egypt ERA) has set the regulations, promotion and awareness for PVs. This approach has been applied for administrative buildings as well.The paper highlights the impact of the previously mentioned mechanisms in deploying PV technologies through small scale projects. It also represents a cost- benefit analysis for the installed systems taking into account the measured value for PV parameters (kWh/kWp, PSH) and daily load profiles of the selected administrative buildings.</p

    Making cities smarter for an inclusive green transition towards a long‐term sustainable development: A critical literature review

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    This review critically approaches the literature on smart cities while describing the significance of more value‐based rationality and more reflexive practice for constructing smart cities, rethinking how human experiences are approached to improve it to be more balanced and engaging. This transition establishes a sense of place in the city necessary to enhance people's attitudes and overall well‐being. As the vision of smart cities promotes them as more liveable cities while focusing on achieving more efficient services, the review clarifies the need to improve the ability of smart cities to produce more engaging experiences to achieve long‐term sustainable development, planning and governance as part of their green transition. The authors promote innovative approaches to realising agendas of citizen engagement and sustainability by clarifying the potential of interdisciplinary cooperation among art, place and technology. This will help redefine progress in city development from merely enhancing basic functions to improving the human experience

    The role of art in smart cities research and making

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    This article promotes the role and importance of art in the research and making of smart cities. To elucidate the potential of using relational artworks for a more vibrant interaction in the city as well as various visuals in knowledge production and/or implications of overlooking them, a case study of Milton Keynes is presented in the article. Visual comparisons and analysis contributed to making the argument clearer by reflecting on the situation on the ground. Qualitative methods have been used for data collection and analysis, which included interviews, document analysis and on-field observations. The findings were presented under three main sections: Innovation in knowledge production, vocabulary and design, and art in Milton Keynes and Milton Keynes in art. The themes are used to clearly discuss the need for innovative methods in knowledge production and cities making while explaining the benefits of integrating art with science. By reflecting on the benefits of accommodating the need for effective communication, higher engagement and fulfilling experience in research and design of cities, the powers of visual and relational art are unpacked throughout the article. Thus, the role of art is introduced to be beyond that of decoration to help facilitate cities development and production

    The Level of Punctuation Usage in Writing among Third Year Pre-service Class Teachers Field study at Education faculty, Tishreen University

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     This research aimed to explore the level of punctuation usage in writing among third year pre-service class teacher at Tishreen University. Thus, the researcher set an unpunctuated text for the student to punctuate it. Then, the tool was administered to 160 pre-service class teachers, registered in 2015/2016 academic year. Findings showed a medium level in using punctuation among the participants; the highest error ratio went to semicolon (94.37%), while the lowest error ratio went to question mark (8.75%). Findings also showed significant differences between students with literary Baccalauréat, and their scientific peers in using punctuation. Moreover, significant differences were found between males and females

    Implant Site Preparation Using Conventional Drilling Technique Versus Magnetic Malleting Technique (Randomized Clinical Study).

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    Background The purpose of our current study is to determine whether using a Magnetic Mallet during oral and implant surgical procedures is more effective than using traditional instruments with regard to complication rate, tissue healing, and surgical results (primary stability and crestal bone loss). According to a number of writers, a Magnetic Mallet can be utilized for implant insertion, ridge expansion, sinus lifts, tooth extractions, and implant site preparation. So, this study was conducted to ascertain whether using a Magnetic Mallet Throughout the process of oral and surgical implant operations is effective and to assume on whether it might help prevent failures and implications. Material and Methods: In the current investigation, nine patients had twenty implants placed bilaterally in the posterior maxilla to compare the advanced osteotome technique (Magnetic Mallet) with the conventional drilling approach clinically and radiographically after loading. They were chosen from the Department of Oral and Maxillofacial Surgery, Faculty of Oral and Dental Medicine, Future University in Egypt\u27s outpatient clinics. On one side, eight patients were recruited as study subjects, while on the other side, then they were recruited as control subjects. They were given one implant on the control side and one on the study side. The last patient had two implants on the control side and two on the research side. Results: It was noticed that Stability at baseline was significantly higher in the Magnetic Mallet (Study group) (71.77±2.71) than in the Conventional (Control group) (68.67±2.36) in our study. When the amount of difference from baseline to 6 months was compared between groups, it was shown that the Magnetic Mallet (Study group) showed an increased gain in stability (6.21±1.78) than the Conventional (Control group) (4.49±0.9). Regarding marginal bone loss, there was no statistically significant difference between the two groups in the current investigation. Conclusion: From the current study it was concluded that the usage of Magnetic Mallets is reported to offer better clinical benefits than the traditional instruments. Due to its safety, predictability, speed, and simplicity of use, it can be useful during dental and implant surgery procedures. The Magnetic Mallet improves implant stability compared to conventional drilling technique, but it doesn\u27t reduce the amount of marginal bone loss around dental implants. The Magnetic Mallet is quick, precise, and effective in bone condensing and an appropriate tool for preparing implant bed in softer maxillary bone

    A Cyber-Physical Architecture for Microgrids based on Deep learning and LORA Technology

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    This paper proposes a cyber-physical architecture for the secured social operation of isolated hybrid microgrids (HMGs). On the physical side of the proposed architecture, an optimal scheduling scheme considering various renewable energy sources (RESs) and fossil fuel-based distributed generation units (DGs) is proposed. Regarding the cyber layer of MGs, a wireless architecture based on low range wide area (LORA) technology is introduced for advanced metering infrastructure (AMI) in smart electricity grids. In the proposed architecture, the LORA data frame is described in detail and designed for the application of smart meters considering DGs and ac-dc converters. Additionally, since the cyber layer of smart grids is highly vulnerable to cyber-attacks, t1his paper proposes a deep-learning-based cyber-attack detection model (CADM) based on bidirectional long short-term memory (BLSTM) and sequential hypothesis testing (SHT) to detect false data injection attacks (FDIA) on the smart meters within AMI. The performance of the proposed energy management architecture is evaluated using the IEEE 33-bus test system. In order to investigate the effect of FDIA on the isolated HMGs and highlight the interactions between the cyber layer and physical layer, an FDIA is launched against the test system. The results showed that a successful attack can highly damage the system and cause widespread load shedding. Also, the performance of the proposed CADM is examined using a real-world dataset. Results prove the effectiveness of the proposed CADM in detecting the attacks using only two samples

    Economic Study to Production and Consumption of Onion and Tomato Crops in Egypt

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    Vegetable crops are considered among the agricultural intensification crops with a quick return due to their short survival in the soil, which aims to achieve national food security due to their daily nutritional importance to humans when consuming them, whether in their fresh or processed form, and despite the attention paid by the state in the recent period to the production of vegetable crops and due to their nutritional importance and value Many of them are exported, but in the recent period it was noticed a decrease in the cultivated area, especially the tomato crop, and the obvious fluctuation in the percentage of self-sufficiency in each of the onion and tomato crops, which was important to study the production and consumption situation of the onion and tomato crop at the national level, The objectives of the study represent some axes in which we can study the production and consumption situation and the rate of self-sufficiency of the onion and tomato crop in Egypt in the period (2001-2018) by studying the development of indicators of production, consumption and self-sufficiency of the onion and tomato crop in Egypt
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