Journal of Engineering and Applied Science
ISSN / EISSN : 1110-1903 / 2536-9512
Published by: Springer Nature (10.1186)
Total articles ≅ 11
Latest articles in this journal
Journal of Engineering and Applied Science, Volume 68, pp 1-12; https://doi.org/10.1186/s44147-021-00013-z
This article investigates utilization of polypropylene microfibers as reinforcement in geopolymer concrete to enhance the ductility characteristics since the geopolymer concrete is considered a brittle material. The polypropylene microfibers were added to geopolymer concrete at the fiber volume content of 0.5%, 1.0%, and 1.5%. In this article, a slump test and compressive strength were tested for geopolymer concretes to measure the effect of polypropylene microfibers on geopolymer concretes. Also, static flexural strength and dynamic loading were applied to find out the attitude of polypropylene fiber-reinforced geopolymer concrete and to measure both the deflection and number of load cycles until failure. While comparing the results with reference geopolymer concrete, all samples were tested at 28 days and, finally, a statistical test was carried out. The results concluded that the use of polypropylene microfibers improves the compressive strength and enhances the properties of polypropylene fiber-reinforced geopolymer concretes, increases the loading for the appearance of the first crack, and decreases the deflection of polypropylene fiber-reinforced geopolymer concretes compared with reference geopolymer concrete.
Journal of Engineering and Applied Science, Volume 68, pp 1-41; https://doi.org/10.1186/s44147-021-00014-y
In recent times, the rapid growth in mobile subscriptions and the associated demand for high data rates fuels the need for a robust wireless network design to meet the required capacity and coverage. Deploying massive numbers of cellular base stations (BSs) over a geographic area to fulfill high-capacity demands and broad network coverage is quite challenging due to inter-cell interference and significant rate variations. Cell-free massive MIMO (CF-mMIMO), a key enabler for 5G and 6G wireless networks, has been identified as an innovative technology to address this problem. In CF-mMIMO, many irregularly scattered single access points (APs) are linked to a central processing unit (CPU) via a backhaul network that coherently serves a limited number of mobile stations (MSs) to achieve high energy efficiency (EE) and spectral gains. This paper presents key areas of applications of CF-mMIMO in the ubiquitous 5G, and the envisioned 6G wireless networks. First, a foundational background on massive MIMO solutions-cellular massive MIMO, network MIMO, and CF-mMIMO is presented, focusing on the application areas and associated challenges. Additionally, CF-mMIMO architectures, design considerations, and system modeling are discussed extensively. Furthermore, the key areas of application of CF-mMIMO such as simultaneous wireless information and power transfer (SWIPT), channel hardening, hardware efficiency, power control, non-orthogonal multiple access (NOMA), spectral efficiency (SE), and EE are discussed exhaustively. Finally, the research directions, open issues, and lessons learned to stimulate cutting-edge research in this emerging domain of wireless communications are highlighted.
Journal of Engineering and Applied Science, Volume 68, pp 1-16; https://doi.org/10.1186/s44147-021-00012-0
As cities get more crowded and polluted, eco-landscape design gains increasing attention. Open spaces play a vital role in healing the natural environment as well as the physical and mental health of the citizens. This paper presents an exploratory eco-park design project in Helwan, Egypt. The project focuses on the opportunity of integrating marginalised natural environments, such as Wadis (dry streams), with the urban fabric through Eco-landscape design. The current work explores the complex environment, characterised by detailed multidisciplinary data, which requires multi-layer analysis. The discussion evaluates the tremendous effect of integrating the participatory qualitative method with other analytical and digital tools, such as modelling and Geographic Information Systems (GIS), to deduce scientific details and activities in the preliminary phases of zoning plans. This results in a constructive framework for merging these multi-methods and tools within the participatory eco-landscape design process. In addition, the conclusion highlights the peculiarity of the eco-landscape design and practice in the current Egyptian situation in a broad sense.
Journal of Engineering and Applied Science, Volume 68, pp 1-18; https://doi.org/10.1186/s44147-021-00011-1
The debate about polycentricity and subordinacy has always been a critical topic that planners, economists, and socialists argued about for centuries. The idea of concentricity vs decentralization has affected all life metabolic activities. Urban structure has always been declared to be the key factor that affects life metabolism significantly. However, after the pandemic COVID-19, the planning strategies have changed dramatically. The main purpose is to investigate the most appropriate urbanization approach that achieves the best development results. The research methodology is to define and measure the fabric independency as an approach to estimate its self-sufficiency that enables it to stand in front of the pandemic challenges at different circumstances. The paper uses the fabric diversity index as a sensitive indicator of independency and polycentricity of the urban structure. The main conclusion for this paper is that independent polycentric urban agglomerations that are strongly linked achieve much better development results than subordinate cities depending on the main core city. The data used for the analysis are extracted from the Urban Atlas developed by the European Environmental Agency in addition to the UN-Habitat annual report. All calculations, analyses, and deductions are exclusively carried by the author.
Journal of Engineering and Applied Science, Volume 68, pp 1-13; https://doi.org/10.1186/s44147-021-00010-2
Collaboration among disciplines is becoming a standard practice in Architecture, Engineering, and Construction (AEC) industry. However, limited studies have addressed the involvement of interdisciplinarity into architectural undergraduate curricula. The study seeks to expand the literature on this topic, namely by offering an alternative model for teaching an Interdisciplinary Design Course (IDC), mainly in architectural engineering departments, with the participation of engineering departments. The authors hypothesize that by the adoption of the IDC, architecture students would have a better understanding of the nature of AEC interdisciplinary design knowledge. The study aims to highlight the value of the IDC and to test the hypothesis. A qualitative research methodology has been adopted, including the design of an experiment and then the application of a case study comprising four instructors and 24 students from four departments in the Faculty of Engineering, Cairo University. Students’ design process, teamwork attitude, and own experiences on the IDC have been recorded using direct observation, interviews, and surveys. Data have been analyzed using descriptive statistics to identify the effectiveness and challenges of the experiment, in addition to the comparison with the traditional design studio. The results have shown the students’ satisfaction with collaboration with their peers from other disciplines, as it boosted their understanding of the integrated design process and increased their knowledge about each other’s discipline. In addition, architecture students commended the IDC much more than the traditional design studio.
Journal of Engineering and Applied Science, Volume 68, pp 1-15; https://doi.org/10.1186/s44147-021-00009-9
Achieving the Sustainable Development Goals (SDGs) by 2030 ad is one of the challenges and among the cross-cutting issues that countries around the world strive to achieve, despite it is not mandatory, to take control of the various negative environmental, economic, social, and urban impacts that threatened cities, in addition to benefits that are realized from achieving it. The research aims to promote the achievement of Sustainable Development Goals from the perspective of solid waste management (SWM) plans and programs, through analyzing and finding the interrelationship between SWM plans and programs and the related specific targets for each goal, in addition to using experts’ questionnaires to conclude the varying degrees of impact of SWM plans and programs at the level of 17 SDGs, which have been classified into groups, according to the most and the least affected by the SWM plans and programs. Where the goals of “sustainable cities and communities” and “good health and well-being” came in the lead of the goals; however, the goals of “quality education” and “peace, justice, and institutions” came in the tail of the goals that are affected by SWM plans and programs, according to the experts’ opinion.
Journal of Engineering and Applied Science, Volume 68, pp 1-25; https://doi.org/10.1186/s44147-021-00001-3
In this study, numerical models were developed to predict the behavior of steel extended end-plate moment connections subjected to static and blast-like loading. Two types of extended end-plate connections were considered, stiffened, and unstiffened, with pretensioned bolts. The models were verified by comparing the results with published experimental data. The models were used to compute the moment-rotation curves for the connection under static loading, and then under different blast durations. The pressure impulse diagram and the energy dissipation for the connection under dynamic loading were determined. The failure modes were examined, and the numerical results were compared with the simplified models presented in codes and standards. Improvement in the performance of the connection by adding one or two stiffeners was demonstrated. For the configuration studied, introducing a stiffener increased plastic dissipation energy for blast loading by 45% compared to the unstiffened connection, whereas under static loading, the plastic energy dissipation for stiffened connection, SC2, was higher than the unstiffened connection by 30%. A conservative estimate for the dynamic increase factor (DIF) was found to be 1.2 for steel yield stress and 1.05 for bolt failure.
Journal of Engineering and Applied Science, Volume 68, pp 1-28; https://doi.org/10.1186/s44147-021-00008-w
The impact echo technique is one of the most useful non-destructive test methods for determining the thickness of concrete or detecting possible cracks or cavities in the internal parts of a concrete structure without damaging the surface. Many types of unstable conditions in railway tracks, including various modes of irregularities, may occur when cavities are generated directly under a concrete slab track or when a slight open space is made under a loose sleeper. In this study, we developed a nondestructive testing (NDT) system for detecting abnormalities in concrete tracks and performed 3D numerical simulations using the ABAQUS finite element analysis (FEA) program to investigate the impact echo response from a concrete track slab with different sizes of cavities. Sections of concrete slab were simulated as solid body masses under the railway tracks with gaps in the bodies themselves or with cavities existing between the track concrete layer (TCL) and the hydraulically stabilized base (HSB). We investigated the locations and depths of the cavities and gaps in the model concrete slab using the acoustic impact echo response based on the frequency response of the elastic waves generated in the slab. In addition, a Short-time Fourier Transform (STFT) and a wavelet technique were adopted for a time frequency analysis. Our study demonstrated that the impact echo technique developed in this study by FEA and NDT can measure and confirm the location and depth of cavities in concrete slabs.
Journal of Engineering and Applied Science, Volume 68, pp 1-19; https://doi.org/10.1186/s44147-021-00006-y
A refining column in the middle east that started its official production in 2020 provides its sour wastewater from all refinery plants to two sour water units (SWS1 and SWS2) to strip H2S and NH3. Sour gas from the refinery uses a lean amine solution for gas sweetening to absorb H2S in different absorbers. Rich amine with H2S is then stripped in two amine regeneration units (ARU1 and ARU2). The overhead of SWS and ARU units provide the acid gas feed to the sulphur recovery unit (SRU) to produce sulphur and prevent any acidic emissions against environmental regulations. First, the SWS1 unit is simulated using Aspen HYSYS V.11. A complete exergy study is conducted in the unit. Exergy destruction, exergy efficiency and percentage share in the destruction are calculated for all equipment. The highest exergy destruction rate was in the stripper with 5028.58 kW and a percentage share of 81.94% of the total destruction. A comparison was conducted between the exergy results of this study with two other exergy studies performed in the same refinery plant. The columns in the three studies showed the highest destruction rates exceeding 78% of the total destruction of each unit. The air coolers showed the second-highest destruction rates in their units with a percentage share exceeding 7% of the total destruction. The pumps showed the lowest destruction rates with values of less than 1% of the total destruction of each unit. Then, an individual simulation is conducted for stripper1 of SWS1, stripper2 for SWS2, regenerator1 of ARU1 and regenerator2 of ARU2. The individual simulations are combined in one simulation named combined simulation to compute the composition of acid gas from SWS and ARU units feeding SRU. Then, the SRU unit is simulated via a special package in HYSYS V.11 named SULSIM. The computed composition from SWS and ARU is exported to excel where it is linked with SRU simulation to calculate sulphur production. For the first time in any article in the world, all data feeding SWS, ARU, and SRU units are connected to a live system named Process Historian Database (PHD) to gather live data from the plant and perform plant optimization.
Journal of Engineering and Applied Science, Volume 68, pp 1-14; https://doi.org/10.1186/s44147-021-00002-2
This study investigates the effect of using steel filings from the waste of blacksmiths workshops on the clay bricks mixture to improve the bricks’ compressive strength. On the other hand, this process can reduce workshops’ waste by recycling it to preserve the resources and achieve sustainability. Adding steel filings to the mixture of red clay bricks was in different proportions by weight (1%, 2%, 3%, and 4%) on prototype bricks produced in a lab. Moreover, it aims to increase the effectiveness of clay bricks used in load-bearing walls, which can be used extensively in economical housing to reduce the cost if its strength increases by utilizing it in the load-bearing walls system instead of skeleton. The experimental approach was adopted to reach conclusions, as it is the appropriate approach suitable for this research. Before and after adding steel filings, many properties were tested, such as dimensions, weight, density, water absorption, and compressive strength. It is observed that on increasing the steel filings ratios by the mixture’s weight, the prototypes’ compressive strength also increases. The highest percentage of increased compressive strength occurred for the specimen with 3% steel filings by the mixture’s weight is (84%).