Advanced Engineering Forum

Journal Information
EISSN : 2234-991X
Published by: Trans Tech Publications, Ltd. (10.4028)
Total articles ≅ 1,434
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Latest articles in this journal

Jorge A. Gordillo
Advanced Engineering Forum, Volume 45, pp 49-56;

This paper shown and describe this behaviour an original conceptual design of an electrical transformer. The device it is constituted by an electrodynamic actuator and piezoelectric crystals.The input AC voltage generates an axial vibration in the electrodynamic actuator. The axial vibration is transmitted to a piezoelectric crystal which is polarized in the axial direction and generates the output voltage. In a reduced volumes and a single step, it would be possible to reach voltages of tens of MV and great transformation ratios-achieving these voltages is impossible with conventional systems-The transformer works at axial resonance of the piezoelectric crystal. This device operates to the frequency of order kHz; therefore could be used to generate electromagnetic waves. The capacitive and inductive at its output negligible respect conventional transformer. This transformer could be used in countless devices, such as gamma‐ray machines, electron microscope, solid-state propulsion system, Ion thruster, small particle accelerator etc.
Advanced Engineering Forum, Volume 45, pp 57-64;

Several researchers working on the axes of solid particle transport, river flow, as well as the vulnerability of structures built on rivers have focused their work on the phenomenon of local scour, where many scour formulas have been proposed. Most of these formulas have been developed using laboratory data, estimated from simplified scaled-down models. This led to uncertainties and considerable inaccuracies in the scour estimation, sometimes causing serious consequences for the stability of structures subject to scour. These formulas were rarely tested using field data, where, until recently, there was very little data to validate them. This study aims to propose a new local scour formula using multiple nonlinear regression (MNLR). The data used is in situ data from an extensive database. The new proposed formula includes different parameters of the three fields involved in the triggering and development of the local scour, namely; the bridge, the flow, and the suspended characteristic of the eroded particle. The results obtained in the training phase and the validation show relatively better performances of the new formula compared to the existing empirical formulas.
Zheng Yi Song, Young Moon
Advanced Engineering Forum, Volume 45, pp 97-102;

Cyber-Manufacturing System (CMS) is a vision for the factory of the future, where physical components and processes are seamlessly integrated with computing processes to form highly adaptive and responsive manufacturing operations. In CMS, manufacturing resources and capabilities are digitized and shared with users and stakeholders through a local area network (LAN) and the Internet. CMS aims to utilize the manufacturing data obtained during all product lifecycle phases to provide agile and scalable manufacturing solutions. Currently, a centralized cloud-based computing environment supported by the distributed Internet of Things (IoT) devices network is used to enable the typical functionalities—such as manufacturing resource sharing and large-scale manufacturing collaborations. However, facing the explosion of manufacturing data from factory floors, cloud-based computing solutions show limitations in providing low-latency services, performing real-time state analysis, configuring the machines, and controlling other executors in the physical manufacturing end. Furthermore, private production data and technical details cannot be appropriately masked in the public cloud platform. In this research, a Cloud-Fog Continuum Computing Architecture is introduced to better utilize and govern the manufacturing data for manufacturing enterprise stakeholders and customers in CMS. A Hadoop-Raspberry Pi computing system is presented as a proof-of-concept of the proposed continuum computing mechanism to provide machining services in CMS.
Fadzai Lesley Chawarambwa, Tika Erna Putri, Pankaj Attri, Kunihiro Kamataki, Naho Itagaki, Kazunori Koga, Masaharu Shiratani
Advanced Engineering Forum, Volume 45, pp 1-13;

In a dye-sensitized solar cell (DSSC) the CE is responsible for the collection of electrons from the external circuit and the electrocatalysis reaction of the electrolyte. This paper reports the effect of spin-coating rate on the surface roughness, film thickness, and electrochemical properties of a Pt polymer counter electrode (CE). In this work, the spin-coating rate has been investigated in the range 1000-6000 rpm and the results indicate that low spin-coating speeds produce the thickest films with the smoothest surfaces, while high spin speeds produce thinner films with higher surface roughness. The thickness of the film decreased from 7.03 μm at 1000 rpm to 1.30 μm at 6000 rpm. Results also indicate a decrease in electrocatalysis properties and conductivity with the increase in film spin-coat rate. The resistance at the CE/electrolyte interface decreased from 9.3 Ω at 1000 rpm to 14.8 Ω at 6000 rpm. The spin-coating rate also affects the light transmittance of the CE and photovoltaic characteristics of the DSSC, such as current density and overall cell conversion efficiency. This study demonstrates a method to develop cost-effective counter electrodes for application in bifacial solar cells.
Adolfo Perez, Armando Roman
Advanced Engineering Forum, Volume 45, pp 43-48;

In this paper a NACA 6412 regulated shape will be inverted to understand the behaviour of the air flow around the shape, this with the intention of convert the lifting effect to a downforce and braking effect changing the shape of the wing, displacing the trailing edge approximately 100mm over the first stage position. Using analysis as Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) to depicts the operational parameters of the two stages of the inverted NACA 6412 air foil. To reach this displacement, the main idea is using a flexure hinge designed as a M-Shape beam, this flexure hinge works as a spring to allows to the morphing wing moves around the 100mm of trailing edge displacement and the spring-beam effect creates an inverse force, when the wing moves close to the110mm and does not exceed the yield strength of the Acrylonitrile butadiene styrene (ABS) of 74Mpa. As a result of this motion parameters, we could integrate a flexure hinge to an inverted air foil regulated to reach braking and downforce forces in order to slow down vehicles or aerodynamic devices.
Kayode Timothy Akindeji, Remy Tiako,
Advanced Engineering Forum, Volume 45, pp 77-96;

This paper presents an optimization model to minimize the fuel cost and CO2 emision on university campuses using an hybrid power system (HPS). The HPS is made up of solar photovoltaic (PV), diesel generator (DG), wind turbine (WT) and battery energy storage system (BESS). Two university campuses are used as case study to investigate the efficiency of the proposed HPS. The objective function is formulated such that each campus load is met by the renewable energy source (RES) when available and the DG only swicthes on when the output of the RES is not eneough to meet the load. The resulting non linear optimization problem is solved using a function in MATLAB called “quadprog”. The results of the simulation are analyzed and compared with the base case in which the DG is used exclusively to meet the entire load. The results show the effectiveness of the optimized HPS in saving fuel when compared to the base case and reflect the effects of seasonal variations in fuel costs.
Youcef Sara, Seghairi Nora, Djoudi Ramzi
Advanced Engineering Forum, Volume 45, pp 65-75;

This work aims to conduct a comparative study between two natural substrates (clay and gravel) used in constructed wetlands to treat domestic wastewater effluent in arid regions. Experiments were carried out using four basins planted with phragmites australis, where two were filled with clay and two with gravel substrates. The efficiency of filtration systems has been studied by monitoring several physicochemical and organic parameters. This study is of great importance in determining the most effective type of local substrate in light of the lack of previous studies and the low spread of CWs in arid regions.Results showed that the clay filters clogged very fast, and the total Suspended Solids increased in the planted clay filter by 4 % and decreased in the planted gravel filter, where the removal efficiency was 73%. The pH was generally around neutral, with values between 6.8 and 7.2 regardless of the substrate, and the temperature was related solely to local weather conditions. The electrical conductivity was higher in the effluent from clay than the gravel filters, with 9.72 and 5.47 mS/cm, respectively. The nitrate concentration increased in all filters due to the complete transformation of ammonium to nitrate. After five days, nitrite and chemical oxygen demand removal efficiencies were 38.33%, 75% in the planted clay filter, and 60%, 88% in the planted gravel filter, respectively.
Ifeoluwaposi Ogundana, Adewale Olalemi, Daniel Arotupin
Advanced Engineering Forum, Volume 45, pp 15-30;

The application of aqueous extracts of leaves, stem and seed of Azadirachta indica as good green corrosion inhibitors of mild steels in 0.25 M hydrochloric acid (HCL) was evaluated. Extracts were prepared by evaporating the filtrate of the aqueous solution obtained from dried samples, hence, used for the preparation of inhibitor test solutions. Mild steel rods of 8 mm diameter were used. Phytochemical screening of aqueous leaf, stem and seed extracts of Azadirachta indica (Neem) and corrosion inhibition rates of the extracts in 0.25 M HCl were determined by gravimetric analysis. The weight loss was calculated after each measurement, the inhibitory efficiency (I%), corrosion rate (Cr) and surface coverage (θ) were calculated using mathematical relationships. The mechanism of inhibitor adsorption on the metal steel surface was studied using Langmuir adsorption isotherms. The results revealed that extracts of leaves, stem and seed of Azadirachta indica were effective at inhibiting the rate of corrosion on the mild steels in 0.25 M HCl medium. The effectiveness of the extracts as corrosion inhibitors was observed to be dependent on the concentration of the extracts. The extracts were most effective after 9 days exposure period with inhibition efficiencies of 94.22 % (leaves), 86.27 % (stem), 83.22 % (seed) at 1.0 g concentration, while at the end of the 15 days exposure period, 1.0 g concentration of the extracts produced the highest inhibition efficiency at 94.17 %, 86.18 % and 83.11 % for the leaves, stem and seed extracts respectively. The Langmuir isotherm was obeyed by the extracts. The findings of this study demonstrated that neem leaves, stem and seed aqueous extracts are good green corrosion inhibitors therefore, their use as corrosion inhibitors should be greatly encouraged.
Prakash Kumar Sen, Mahesh Bhiwapurkar, S.P. Harsha
Advanced Engineering Forum, Volume 45, pp 31-42;

In service condition rail joints, especially the weldments are under the action of various loadings which are not only working in multiple axis direction but also time-dependent having a cyclic and mixed-mode in nature and non-relative to each other. The surface of the rail and its weldment is acted by very high repetitive stress through the wheel and because of this contact stress the running surface or subsurface may have cracks or fractures due to fatigue. This work is based on numerical simulation of an aluminum thermite weldment on a UIC 60 rail under multi-axial fatigue crack propagation under the friction with surficial interaction between weldment and wheel with bending load due to vertically applied load through the wheel on the weld. Since contact is highly influenced by vertical load and also for minimizing the simulation time the lateral and longitudinal traction forces are not included in this study. The work formulation and discretization have been done with the finite element method and a non-linear lagrangian algorithm solver is applied. A 3-D rail-weld wheel model assembly and a semi-elliptical crack as a flaw on the weld surface are used to identify 3-Modes of SIFs along with its graphical plot generation. Simulation is performed under multi-axial weld wheel surface contact at different locations on weld running surface, taking into account varying position of fracture crack on weld 3-D model to calculate fracture life of weld joint and observation of fatigue crack propagation. This work involves the numerical and theoretical approach of fracture mechanics on created FE fatigue model using the Linear Elastic Fracture Mechanics (LEFM) method following Paris law for fracture mechanics. All the numerical simulation for critical fracture dimension and cycle count with stress intensity factor for weld failure data is estimated using software ANSYS 2020 academic and plotted, then comparison of predicted and observed transverse crack growth behavior and fatigue life of weld, based on Millions Gross Tonnes (MGT) is discussed.
Hadia Aounallah, Mourad Zaabat, Abdelouahab Noua, Tarek Diab Ounis
Advanced Engineering Forum, Volume 44, pp 17-28;

In this study, Aluminum (Al) and Manganese (Mn) co-doped ZnO thin films were successfully synthesized into glass substrates by the sol-gel dip-coating method with different Al concentrations (1%, 3%, and 5%). The structural, morphological, and optical properties of the obtained thin films were characterized by X-ray diffraction (XRD), Atomic force microscopy (AFM), and UV–VIS spectroscopy. XRD pattern revealed that the films have a polycrystalline hexagonal structure with a preferred orientation along (101) for undoped ZnO thin films, further the co-doped ZnO thin films show a shift in the preferred orientation to (002) direction without any Mn or Al related phases. The morphological analysis showed that the films have a uniform and dense ZnO grains, without any voids and cracks, and it was found that the surface roughness (RMS) increases from 8,27 to 14,43 nm when the Al doping concentration increased from 1% to 3%; however, when Al doping concentration is 5%, the RMS value decreased to 2,80 nm. From the optical analysis, the higher average transmittance was found to be corresponding to 5% Al doping concentration.
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