Feature Papers in Eng

A special issue of Eng (ISSN 2673-4117).

Deadline for manuscript submissions: closed (28 February 2022) | Viewed by 45648

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INAMAT^2-Departamento de Ciencias, Edificio de los Acebos, Universidad Pública de Navarra, Campus de Arrosadía, 31006 Pamplona, Spain
Interests: preparation, characterization, and catalytic activity of metal-supported catalysts; surface properties of solids; pollutants adsorption; environmental management; industrial waste valorization
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Special Issue Information

Dear Colleagues,

As Editor-in-Chief of Eng, I am pleased to announce this Special Issue, entitled "Feature Papers in Eng". This Special Issue will be a collection of high-quality reviews and original papers from editorial board members, guest editors, and leading researchers discussing new knowledge or new cutting-edge developments in the field of engineering. The potential topics include, but are not limited to:

  • Electrical, electronic, and information engineering
  • Chemical and materials engineering
  • Energy engineering
  • Mechanical and automotive engineering
  • Industrial and manufacturing engineering
  • Civil and structural engineering
  • Aerospace engineering
  • Biomedical engineering
  • Geotechnical engineering and engineering geology
  • Ocean and environmental engineering

We therefore very much look forward to your valued contributions to make this Special Issue a reference resource of essential knowledge for future researchers in the engineering field.

Prof. Dr. Antonio Gil Bravo
Guest Editor

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Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Eng is an international peer-reviewed open access quarterly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Electrical, electronic, and information engineering
  • Chemical and materials engineering
  • Energy engineering
  • Mechanical and automotive engineering
  • Industrial and manufacturing engineering
  • Civil and structural engineering
  • Aerospace engineering
  • Biomedical engineering
  • Geotechnical engineering and engineering geology
  • Ocean and environmental engineering

Published Papers (15 papers)

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Editorial

Jump to: Research, Review

5 pages, 204 KiB  
Editorial
Special Issue: Feature Papers in Eng 2021
by Antonio Gil Bravo
Eng 2022, 3(2), 254-258; https://doi.org/10.3390/eng3020019 - 01 May 2022
Viewed by 1787
Abstract
The aim of this first Eng Special Issue is to collect experimental and theoretical research relating to engineering science and technology [...] Full article
(This article belongs to the Special Issue Feature Papers in Eng)

Research

Jump to: Editorial, Review

18 pages, 4181 KiB  
Article
Generalized Damping Model for MEMS Oscillators from Molecular to Viscous Flow Regime
by Tobias Zengerle, Abdallah Ababneh and Helmut Seidel
Eng 2022, 3(1), 124-141; https://doi.org/10.3390/eng3010011 - 25 Feb 2022
Cited by 1 | Viewed by 2131
Abstract
In this study, we investigate the damping phenomena acting on piezoelectrically driven MEMS oscillators. Three different geometrical shapes of MEMS oscillators are presented, including cantilevers, bending oscillators, and paddle oscillators. An analytical model for their resonance frequencies is derived. The bending modes of [...] Read more.
In this study, we investigate the damping phenomena acting on piezoelectrically driven MEMS oscillators. Three different geometrical shapes of MEMS oscillators are presented, including cantilevers, bending oscillators, and paddle oscillators. An analytical model for their resonance frequencies is derived. The bending modes of these micro-oscillator structures are characterized regarding their resonance frequency and their quality factor as a function of the ambient pressure in a nitrogen atmosphere as well as the dependence on the distance to a neighboring plate representing a geometrical boundary (e.g., to the package or to the mounting). The investigations cover a pressure range from 10−3 mbar up to 900 mbar and a gap width from 150 µm to 3500 µm. Consequently, a Knudsen number range over six orders of magnitude from 100 to 10−4 is covered. The measurement data are evaluated with a generalized damping model consisting of four parts representing the individual damping mechanisms (intrinsic, molecular, transitional, and viscous). The evaluated parameters are analyzed as a function of the resonance frequency and the gap width. The data reveal an exponential growing saturation behavior, which is determined by two characteristic lengths, being correlated with the viscous and the thermal boundary layer thickness, respectively. This leads to an estimation of the strength and of the range of the damping effect just by calculating the boundary layer thicknesses given by the resonance frequency and the gas properties. From these results, we gain fundamental insights on the viscous and transitional damping mechanisms as well as on the intrinsic losses. In conclusion, a basic concept is provided to reduce the damping of micro-oscillator bending modes and thus increase the quality factor. Additionally, the results are supported by finite element simulations revealing the temperature and pressure distribution within the gap. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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8 pages, 1096 KiB  
Communication
An Analytical Method to Estimate Supersaturation in Gas–Liquid Systems as a Function of Pressure-Reduction Step and Waiting Time
by Sushobhan Pradhan and Prem Kumar Bikkina
Eng 2022, 3(1), 116-123; https://doi.org/10.3390/eng3010010 - 21 Feb 2022
Cited by 5 | Viewed by 3083
Abstract
When the concentration of a gas exceeds the equilibrium concentration in a liquid, the gas–liquid system is referred as a supersaturated system. The supersaturation can be achieved by either changing the pressure and/or temperature of the system. The gas from a supersaturated liquid [...] Read more.
When the concentration of a gas exceeds the equilibrium concentration in a liquid, the gas–liquid system is referred as a supersaturated system. The supersaturation can be achieved by either changing the pressure and/or temperature of the system. The gas from a supersaturated liquid escapes either through bubble nucleation that usually occurs on solid surface and/or gas diffusion through the gas–liquid interface. The bubble nucleation requires a minimum threshold supersaturation. A waiting time is required to observe whether the applied supersaturation is sufficient to initiate bubble nucleation. When the supersaturation is not sufficient to cause bubble nucleation, some or all of the supersaturated gas may diffuse out from the liquid through the gas–liquid interface before further reducing the pressure in order to increase the supersaturation. In this article, using Fick’s second law of diffusion and Henry’s law, an analytical method is proposed to estimate the level of supersaturations generated in three gas–liquid systems at different step-down pressures. Characteristic times of the gas–liquid systems were estimated to validate whether the waiting times used in this study are in accordance with the semi-infinite diffusion model used to estimate the supersaturations generated. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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16 pages, 2206 KiB  
Article
Optimal Hybridization of Conventional ICE Vehicles
by Zhemin Hu, Ramin Tafazzoli Mehrjardi, Lin Lai and Mehrdad Ehsani
Eng 2021, 2(4), 592-607; https://doi.org/10.3390/eng2040037 - 12 Nov 2021
Cited by 3 | Viewed by 2541
Abstract
Most commercially available hybrid electric vehicle (HEV) drivetrains are made of small internal combustion (IC) engines and large electric drives to improve fuel economy. They usually have higher cost than the conventional IC-engine-based vehicles because of the high costs of the electric drives. [...] Read more.
Most commercially available hybrid electric vehicle (HEV) drivetrains are made of small internal combustion (IC) engines and large electric drives to improve fuel economy. They usually have higher cost than the conventional IC-engine-based vehicles because of the high costs of the electric drives. This paper proposes a hybridized powertrain composed of the original full-size engine of the vehicle and a universally optimum size parallel electric drive. The dynamic programming (DP) algorithm was used to obtain the sensitivity of the maximum miles per gallon (MPG) values versus the power rating of the electric drive. This sensitivity was then analyzed to determine the optimal window of the electric drive power ratings. This was proven to be universal for all passenger cars of various masses and engine powers. The fuel economy and vehicle performance of this HEV was compared with those of the 2019 Toyota Corolla, a conventional IC-engine-based vehicle, and the 2019 Toyota Prius, a commercially available HEV. The results showed that the proposed universally optimized HEV powertrain achieved better fuel economy and vehicle performance than both the original ICE and HEV vehicles, at low additional vehicle cost. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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18 pages, 3554 KiB  
Article
Eco-Dimensioning Approach for Planar Transformer in a Dual Active Bridge (DAB) Application
by Glauber de Freitas Lima, Boubakr Rahmani, Maud Rio, Yves Lembeye and Jean-Christophe Crebier
Eng 2021, 2(4), 544-561; https://doi.org/10.3390/eng2040035 - 09 Nov 2021
Cited by 4 | Viewed by 3199
Abstract
Power electronics converters are traditionally designed regarding efficiency, power density, cost, and reliability figures of merit. Today, with the extreme spread of power electronic applications in our modern societies, together with the earth limits in terms of materials resources, it is important to [...] Read more.
Power electronics converters are traditionally designed regarding efficiency, power density, cost, and reliability figures of merit. Today, with the extreme spread of power electronic applications in our modern societies, together with the earth limits in terms of materials resources, it is important to consider the ecological impact of the converter not only during its usage, but over its whole life cycle. This article introduces an eco-dimensioning methodology for analyzing and accounting for the energy consumption over the entire converter life. The analysis is applied on a small DC-DC converter considering the main components dual active bridge (DAB) converter. The planar transform is one of the key elements modeled in this article, including material and manufacturing conditions. The traditional and eco-dimensioning approaches are carried out and compared in order to emphasize the possible consequences on total energy cost. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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13 pages, 1012 KiB  
Article
Analysis of Available Components and Performance Estimation of Optical Multi-Band Systems
by Dimitris Uzunidis, Fotini Apostolopoulou, Gerasimos Pagiatakis and Alexandros Stavdas
Eng 2021, 2(4), 531-543; https://doi.org/10.3390/eng2040034 - 08 Nov 2021
Cited by 4 | Viewed by 2469
Abstract
Optical multi-band (OMB) systems exploit the low-loss spectrum of the single mode fiber (SMF) and are key enablers to increase the transportation capacity and node connectivity of already deployed systems. The realization of OMB systems is mainly based on the technological advances on [...] Read more.
Optical multi-band (OMB) systems exploit the low-loss spectrum of the single mode fiber (SMF) and are key enablers to increase the transportation capacity and node connectivity of already deployed systems. The realization of OMB systems is mainly based on the technological advances on the component and system level, and for this purpose, a broad gamut of various structural elements, such as transceivers, amplifiers, filters, etc. have been commercialized already or are close to commercialization. This wide range of options, which aid in unlocking the concurrent transmission in all amplification bands, is reviewed here for the first time, whilst their pros and cons as well as their limitations are discussed. Furthermore, the needs for additional components in order to fully exploit the ≈390 nm low-loss wavelength range of SMF, which spans from 1260 to 1650 nm, are highlighted. Finally, based on a physical layer formalism, which incorporates the impact of the most important physical layer constraints for an OMB system, the attainable capacity and transparent reach of each amplification band are quantified. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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11 pages, 5235 KiB  
Article
Human Body Specific Absorption Rate Reduction Employing a Compact Magneto-Dielectric AMC Structure for 5G Massive-MIMO Applications
by Reza Karimian, Mansoor Dashti Ardakani, Shahrokh Ahmadi and Mona Zaghloul
Eng 2021, 2(4), 501-511; https://doi.org/10.3390/eng2040032 - 04 Nov 2021
Cited by 9 | Viewed by 2702
Abstract
A compact artificial magnetic conductor (AMC) structure for the application of specific absorption rate (SAR) reduction is presented in this paper. A magneto-dielectric (MD) structure as a host of AMC substrate is used to miniaturize the AMC size. The magneto-dielectric has been designed [...] Read more.
A compact artificial magnetic conductor (AMC) structure for the application of specific absorption rate (SAR) reduction is presented in this paper. A magneto-dielectric (MD) structure as a host of AMC substrate is used to miniaturize the AMC size. The magneto-dielectric has been designed with a low-profile spiral loop in a way to have a high permittivity and permeability for the desired center frequency of 3.5 GHz. Simulation results confirm the zero-degree reflection phase of the proposed AMC unit cell. Moreover, a 70% reduction has been achieved in comparison to the conventional AMC. To validate the simulation results, a prototype of the board is fabricated and measured with a coplanar waveguide (CPW) antenna for the reflection coefficient. The measurement results display an excellent agreement with the simulation ones. A VOXEL model of a human body is utilized to determine the SAR value of the proposed structure. Considering the maximum SAR value for an average of 10 g human tissue, more than 70% SAR reduction is verified for the CPW antenna with the recommended MD-AMC structure compared to a conventional single CPW antenna. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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12 pages, 3233 KiB  
Article
The Application of Food-Grade Chemical Treatment and Its Effect on the Mechanical Performance Characteristics of Ham Nets
by Md. Al-Amin, Charles Freeman, Wes Schilling, Catherine Black, Yan Li Campbell, Wenjie Shao, Santanu Kundu and Anandavalli Varadajan
Eng 2021, 2(4), 468-479; https://doi.org/10.3390/eng2040029 - 22 Oct 2021
Cited by 4 | Viewed by 2293
Abstract
This study involves the use of food-grade chemicals in the integrated pest management of dry-cured ham through the use of 100% polyester weft knitted mesh nets, an idea that was derived from a previously published study in the literature. Tubular mesh nets that [...] Read more.
This study involves the use of food-grade chemicals in the integrated pest management of dry-cured ham through the use of 100% polyester weft knitted mesh nets, an idea that was derived from a previously published study in the literature. Tubular mesh nets that are used to contain dry-ageing hams, commonly referred to as ham nets, were treated with a patent-pending food-grade chemical solution (40% Propylene Glycol + 1% Propylene Glycol Alginate + 1% Carrageenan) to control ham mites. Both treated and untreated ham nets were compared for mechanical performance characteristics based on the following standards: abrasion resistance (ASTM D4966), elastic recovery (BS EN 14704-1:2005), breaking strength (ASTM D5034-09), and bursting strength (ASTM D3786). The results indicate that the chemical treatment had minimal to no impact on the mechanical performance characteristics of ham nets. The obtained SEM images also showed no negative effect on the fiber morphology due to the applied chemical solution. The findings support the use of treated ham nets to increase the end-use functionality and provide ham producers an option for integrated pest management without compromising mechanical performance needs. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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19 pages, 5437 KiB  
Article
An Investigation into Current Sand Control Testing Practices for Steam Assisted Gravity Drainage Production Wells
by Omar Kotb, Mohammad Haftani and Alireza Nouri
Eng 2021, 2(4), 435-453; https://doi.org/10.3390/eng2040027 - 08 Oct 2021
Cited by 5 | Viewed by 2875
Abstract
Sand control screens (SCD) have been widely installed in wells producing bitumen from unconsolidated formations. The screens are typically designed using general rules-of-thumb. The sand retention testing (SRT) technique has gained attention from the industry for the custom design and performance assessment of [...] Read more.
Sand control screens (SCD) have been widely installed in wells producing bitumen from unconsolidated formations. The screens are typically designed using general rules-of-thumb. The sand retention testing (SRT) technique has gained attention from the industry for the custom design and performance assessment of SCD. However, the success of SRT experimentation highly depends on the accuracy of the experimental design and variables. This work examines the impact of the setup design, sample preparation, near-wellbore stress conditions, fluid flow rates, and brine chemistry on the testing results and, accordingly, screen design. The SRT experiments were carried out using the replicated samples from the McMurray Formation at Long Lake Field. The results were compared with the test results on the original reservoir samples presented in the literature. Subsequently, a parametric study was performed by changing one testing parameter at a test, gradually making the conditions more comparable to the actual wellbore conditions. The results indicate that the fluid flow rate is the most influential parameter on sand production, followed by the packing technique, stress magnitude, and brine salinity level. The paper presents a workflow for the sand control testing procedure for designing the SCD in the steam-assisted gravity drainage (SAGD) operations. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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15 pages, 7784 KiB  
Article
Effect of Martensitic Transformation and Grain Misorientation on Surface Roughening Behavior of Stainless Steel Thin Foils
by Abdul Aziz, Ming Yang, Tetsuhide Shimizu and Tsuyoshi Furushima
Eng 2021, 2(3), 372-385; https://doi.org/10.3390/eng2030024 - 15 Sep 2021
Cited by 2 | Viewed by 2763
Abstract
The surface roughening (Ra), martensitic phase transformation (MPT), and grain misorientation (GMO) behavior of stainless steel 304 and 316 in various grain sizes (Dg) were studied experimentally, including five cycles of sequential uniaxial tensile stress testing and Scanning Electron Microscope-Electron Back Scattered Diffraction [...] Read more.
The surface roughening (Ra), martensitic phase transformation (MPT), and grain misorientation (GMO) behavior of stainless steel 304 and 316 in various grain sizes (Dg) were studied experimentally, including five cycles of sequential uniaxial tensile stress testing and Scanning Electron Microscope-Electron Back Scattered Diffraction (SEM-EBSD) investigation. The MPT and GMO characteristics were sequentially investigated using tensile testing and SEM-EBSD analysis. The correlation between MPT, GMO, martensitic volume fraction (Mf), and Ra behavior were investigated. The experimental results showed that increasing the total strain from 5.0% to 25.0% increased the MPT, GMO, and Mf, which were transformed from the metastable austenitic phase in stainless steel (SUS) 304. The increasing total strain increased Ra for all kinds of Dg. Furthermore, SUS 304 and SUS 316 were used to compare the roughening mechanism. The MPT was very high and spread uniformly in fine grain of SUS 304 thin foil, but the MPT was low and not uniform in coarse grain of SUS 304 thin foil. There was no MPT in SUS 316 thin foil, both in coarse and fine grain. The GMO in fine grains, both in SUS 304 and SUS 316 thin foils, spread uniformly. The GMO in coarse grains, both in SUS 304 and SUS 316 thin foils, did not spread uniformly. Surface roughness increased higher in coarse grain than fine grain for both of SUS 304 and SUS 316 thin foil. SUS 304 increased higher than SUS 316 thin foil. The effect of inhomogeneous deformation due to the MPT is a more important factor than GMO in coarse grain. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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17 pages, 4233 KiB  
Article
Ultrasonic Effects on Foam Formation of Fruit Juices during Bottling
by Julian Thünnesen, Bernhard Gatternig and Antonio Delgado
Eng 2021, 2(3), 356-371; https://doi.org/10.3390/eng2030023 - 14 Sep 2021
Cited by 4 | Viewed by 3458
Abstract
Non-carbonated fruit juices often tend to foam over during bottling. The resulting foam height corresponds to the equilibrium of foam formation and decay. Therefore, the foam unexpectedly occupies more space in the bottle and carries parts of the juice out of the bottle, [...] Read more.
Non-carbonated fruit juices often tend to foam over during bottling. The resulting foam height corresponds to the equilibrium of foam formation and decay. Therefore, the foam unexpectedly occupies more space in the bottle and carries parts of the juice out of the bottle, resulting in product loss under filled containers and hygienic problems in the plant. Chemical antifoams are likewise undesirable in most cases. Recent ultrasonic defoamers are effective but only capable outside the container and after the filling. In this article, a lateral ultrasonication through the bottle wall with frequencies between 42 and 168 kHz is used in-line for non-invasive foam prevention during filling. Foam formation during hot bottling of orange juice, apple juice, and currant nectar at 70 °C happens at flow rates between 124–148 mL/s. The comparably high frequencies have a particular influence on the fresh foams, where a large fraction of small resonant bubbles is still present. Foam volume reductions of up to 50% are reached in these experiments. A low power of 15 W was sufficient for changing the rise of entrained bubbles and minimizing the foam development from the start. The half-life of the remaining foam could be reduced by up to 45% from the reference case. The main observed effects were a changed rise of entrained bubbles and an increased drainage. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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16 pages, 677 KiB  
Article
Multi-Point Shape Optimization of a Horizontal Axis Tidal Stream Turbine
by Hassan el Sheshtawy, Ould el Moctar and Satish Natarajan
Eng 2021, 2(3), 340-355; https://doi.org/10.3390/eng2030022 - 30 Aug 2021
Cited by 3 | Viewed by 2915
Abstract
A method was developed to perform shape optimization of a tidal stream turbine hydrofoil using a multi-objective genetic algorithm. A bezier curve parameterized the reference hydrofoil profile NACA 63815. Shape optimization of this hydrofoil maximized its lift-to-drag ratio and minimized its pressure coefficient, [...] Read more.
A method was developed to perform shape optimization of a tidal stream turbine hydrofoil using a multi-objective genetic algorithm. A bezier curve parameterized the reference hydrofoil profile NACA 63815. Shape optimization of this hydrofoil maximized its lift-to-drag ratio and minimized its pressure coefficient, thereby increasing the turbines power output power and improving its cavitation characteristics. The Elitist Non-dominated Sorting Genetic Algorithm (NSGA-II) was employed to perform the shape optimization. A comparative study of two- and three-dimensional optimizations was carried out. The effect of varying the angle of attack on the quality of optimized results was also studied. Predictions based on two-dimensional panel method results were also studied. Predictions based on a two-dimensional panel method and on a computational fluid dynamics code were compared to experimental measurements. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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Review

Jump to: Editorial, Research

14 pages, 1322 KiB  
Review
A Review on the Synthesis and Current and Prospective Applications of Zirconium and Titanium Phosphates
by Zakariae Amghouz, José R. García and Alaa Adawy
Eng 2022, 3(1), 161-174; https://doi.org/10.3390/eng3010013 - 14 Mar 2022
Cited by 10 | Viewed by 3555
Abstract
Metal phosphates represent an important group of materials with established industrial applications that are still attracting special scientific interest, owing to their outstanding physical and chemical properties. In this review, we account on the different synthetic routes and applications of zirconium and titanium [...] Read more.
Metal phosphates represent an important group of materials with established industrial applications that are still attracting special scientific interest, owing to their outstanding physical and chemical properties. In this review, we account on the different synthetic routes and applications of zirconium and titanium phosphates, with a special focus on their application in the medicinal field. While zirconium phosphate has been extensively studied and explored with several reported industrial and medicinal applications, especially for drug delivery applications, titanium phosphates have not yet attracted the deserved attention regarding their established applications. However, titanium phosphates have been the focus of several structural studies with their different polymorphic forms, varied chemical structures, and morphologies. These variations introduce titanium phosphates as a strong candidate for technological and, particularly, biomedical applications. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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14 pages, 1036 KiB  
Review
A Critical Look at the Need for Performing Multi-Hazard Probabilistic Risk Assessment for Nuclear Power Plants
by Egemen M. Aras and Mihai A. Diaconeasa
Eng 2021, 2(4), 454-467; https://doi.org/10.3390/eng2040028 - 10 Oct 2021
Cited by 10 | Viewed by 3333
Abstract
Probabilistic Risk Assessment (PRA) is one of the technologies that is used to inform the design, licensing, operation, and maintenance activities of nuclear power plants (NPPs). A PRA can be performed by considering the single hazard (e.g., earthquake, flood, high wind, landslide) or [...] Read more.
Probabilistic Risk Assessment (PRA) is one of the technologies that is used to inform the design, licensing, operation, and maintenance activities of nuclear power plants (NPPs). A PRA can be performed by considering the single hazard (e.g., earthquake, flood, high wind, landslide) or by considering multi-hazards (e.g., earthquake and tsunami, high wind and internal fire). Single hazard PRA was thought sufficient to cover the analysis of a severe accident until the Fukushima Daiichi NPP accident in 2011. Since then, efforts were made to consider multi-hazards as well; thus, multi-hazard PRAs are starting to be seen as being indispensable for NPPs. In addition to the changing frequency of global and local natural hazards, other reasons to be highlighted are that the number and diversity of NPPs will probably increase. Moreover, advanced reactors are close to becoming a reality by designing them with passive safety systems, smaller, standardized, and even transportable to make them cheaper across the design, licensing construction, and operation stages. Thus, multi-hazards should be addressed in any future full-scope PRA. Although we found a few studies discussing multi-hazards, a general framework for multi-hazard PRA is still missing. In this paper, we argue that the starting point for any multi-hazard PRA general framework should be the Advanced Non-LWR Licensing Basis Event Selection (LBE) Approach and Probabilistic Risk Assessment Standard for Non-Light Water Reactor (non-LWR) Nuclear Power Plants. For Probabilistic Risk Assessment (PRA), history has shown us the path forward before, with Three Mile Accident being seen as one milestone to understand the necessity of PRA. The Fukushima Daiichi NPP Accident is another milestone in the development of PRA, showing the need for performing multi-hazard PRA for the current and future NPPs. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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30 pages, 3886 KiB  
Review
Simulation and Sensitivity Analysis for Various Geometries and Optimization of Solid Oxide Fuel Cells: A Review
by Mina Tonekabonimoghaddam and Ahmad Shamiri
Eng 2021, 2(3), 386-415; https://doi.org/10.3390/eng2030025 - 17 Sep 2021
Cited by 3 | Viewed by 4335
Abstract
Solid oxide fuel cells (SOFCs) are considered as one of the most promising fuel cell types for application as high efficiency power generators. This work reviews the use of computational fluid dynamics (CFD) to maximise SOFC performance and life, and minimise cost, by [...] Read more.
Solid oxide fuel cells (SOFCs) are considered as one of the most promising fuel cell types for application as high efficiency power generators. This work reviews the use of computational fluid dynamics (CFD) to maximise SOFC performance and life, and minimise cost, by considering numerous configurations and designs. A critical analysis of available literature proves that detailed research on the simulation of thermal stress and its damaging impact on the SOFC is still in its early stage of development. Numerical simulation is expected to help optimize the design, operating parameters and fuel cell materials. Therefore, sensitivity analysis of fuel cell parameters using simulation models is analysed to address the issue. Finally, the present status of the SOFC optimization efforts is summarized so that unresolved problems can be identified and solved. Full article
(This article belongs to the Special Issue Feature Papers in Eng)
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