Journal Description
Eng
Eng
is an international, peer-reviewed, open access journal on all areas of engineering, published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within ESCI (Web of Science), Scopus, EBSCO and other databases.
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 28.3 days after submission; acceptance to publication is undertaken in 3.6 days (median values for papers published in this journal in the first half of 2024).
- Recognition of Reviewers: APC discount vouchers, optional signed peer review, and reviewer names published annually in the journal.
Latest Articles
Economic, Societal, and Environmental Impacts of Available Energy Sources: A Review
Eng 2024, 5(3), 1232-1265; https://doi.org/10.3390/eng5030067 (registering DOI) - 28 Jun 2024
Abstract
The impacts that the available energy sources have had on society, the environment, and the economy have become a focus of attention in recent years, generating polarization of opinions. Understanding these impacts is crucial for rational evaluation and the development of strategies for
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The impacts that the available energy sources have had on society, the environment, and the economy have become a focus of attention in recent years, generating polarization of opinions. Understanding these impacts is crucial for rational evaluation and the development of strategies for economic growth and energy security. This review examines such impacts of the main energy resources currently exploited or in development, including fossil fuels, geothermal, biomass, solar, hydropower, hydrogen, nuclear, ocean, and wind energies on society through analysis and comparison. It is essential to consider how high energy demand influences energy prices, the workforce, and the environment and to assess the advantages and disadvantages of each energy source. One significant finding from this review is that the levelized cost of energy (LCOE) may vary substantially depending on the energy source used and show substantial ranges for different applications of the same energy source. Nuclear energy has the lowest LCOE range whereas ocean energy has the highest LCOE range among the nine energy sources considered. Fossil fuels were found to have the most substantial societal impacts, which involved on the positive side providing by far the largest number of jobs and highest tax revenues. However, on the negative side, fossil fuels, biomass, and nuclear energy sources pose the most significant health threats and social well-being impacts on communities and societies compared to other energy sources. On the other hand, solar, ocean and wind energy pose the lowest risk in terms of health and safety, with solar and wind also currently providing a substantial number of jobs worldwide. Regarding environmental consequences, fossil fuels generate the highest greenhouse gas (GHG) emissions and have the highest adverse impacts on ecosystems. In contrast, nuclear, ocean, solar and wind energies have the lowest GHG emissions and low to moderate impacts on ecosystems. Biomass, geothermal and hydropower energy sources have moderate to high ecosystem impacts compared to the other energy sources. Hydropower facilities require the most materials (mainly concrete) to build per unit of energy generated, followed by wind and solar energy, which require substantial steel and concrete per unit of energy generated. The lack of substantial materials recycling causes associated with solar and wind energy sources. All the energies that use thermal power generation process consume substantial quantities of water for cooling. The analysis and comparisons provided in this review identified that there is an urgent need to transition away from large-carbon-footprint processes, particularly fossil fuels without carbon capture, and to reduce the consumption of construction materials without recycling, as occurs in many of the existing solar and wind energy plants. This transition can be facilitated by seeking alternative and more widely accessible materials with lower carbon footprints during manufacturing and construction. Implementing such strategies can help mitigate climate change and have a positive impact on community well-being and economic growth.
Full article
(This article belongs to the Special Issue GeoEnergy Science and Engineering 2024)
Open AccessArticle
The Issue of Estimating the Maintenance and Operation Costs of Buildings: A Case Study of a School
by
Dino Obradović, Martina Briš Alić and Ksenija Čulo
Eng 2024, 5(3), 1209-1231; https://doi.org/10.3390/eng5030066 - 27 Jun 2024
Abstract
The operations and maintenance phase is typically the longest phase within the building life cycle. Proper and consistent building maintenance is imperative for several reasons, including extending the life of buildings, improving occupants’ comfort and safety, and ultimately saving on long-term costs. Budgets
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The operations and maintenance phase is typically the longest phase within the building life cycle. Proper and consistent building maintenance is imperative for several reasons, including extending the life of buildings, improving occupants’ comfort and safety, and ultimately saving on long-term costs. Budgets for maintenance should be foreseen. The costs of statutory periodic inspections, the costs of replacing worn materials and elements, the costs of periodic works and repairs, the costs of reactive maintenance and the costs of operation will be shown for the analyzed building—a school. This paper outlines the development of a 15-year maintenance plan and program for the building, covering the period from 2024 to 2038. The plan incorporates a discount rate of 3.64% and accounts for inflation when calculating costs. The present value of the costs of maintenance and operation of the building for 15 years is EUR 1,978,292.20 and the largest share of these costs is the operation cost of the building with EUR 1,599,002.18 (80.83%). A sensitivity analysis was conducted by varying the discount rate and analysis period, resulting in recalculated present values for maintenance costs. The analysis reveals a correlation of 26.73% between the present value of maintenance and operation costs over a 15-year period and the associated capital costs.
Full article
(This article belongs to the Section Chemical, Civil and Environmental Engineering)
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Open AccessArticle
A New Algorithmic Method for Reverse Osmosis Desalination Analysis: Design Optimization and Parametric Study
by
Rima Aridi, Mohamad Al Mawla, Elias Harika, Thierry Lemenand, Mahmoud Khaled and Mostafa Gad El-Rab
Eng 2024, 5(3), 1183-1208; https://doi.org/10.3390/eng5030065 - 26 Jun 2024
Abstract
Population growth, coupled with industrial and agricultural development, has resulted in increased demand for freshwater supply. For countries with scarce water resources, desalination constitutes the only viable solution to this problem. Reverse osmosis (RO) technology has become widely used as the membrane materials
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Population growth, coupled with industrial and agricultural development, has resulted in increased demand for freshwater supply. For countries with scarce water resources, desalination constitutes the only viable solution to this problem. Reverse osmosis (RO) technology has become widely used as the membrane materials have been upgraded and the costs have been reduced. Nowadays, RO is the foremost technology for desalting different types of water such as seawater, brackish, and tap water. However, its design is critical since many parameters are involved in obtaining a good design. The high use of RO encourages the establishment of a procedure that facilitates the design process and helps in obtaining an optimum-performance RO desalination system. This paper presents a procedure divided into three parts: (1) classifying RO parameters; (2) choosing the parameters in a certain order and doing the calculation process through 12 steps; and (3) then inserting the selected parameters and the obtained values on RO System Analysis (ROSA) software. These points are then summarized by creating an algorithmic chart to follow during the design phase of the RO system using ROSA. An example on the proposed list is then taken to validate the procedure, and a comparison is conducted on choosing different values for the parameters. The results of this comparative study show that choosing different parameters affects the RO system productivity. Additionally, every design has a specific optimum set of parameters, which depends upon the design constraints set by the user.
Full article
(This article belongs to the Section Chemical, Civil and Environmental Engineering)
Open AccessArticle
Recalibrated Correlations between Dynamic Cone Penetrometer (DCP) Data and California Bearing Ratio (CBR) in Subgrade Soil
by
Jirawat Chokkerd, Artit Udomchai, Sivarit Sultornsanee, Niwat Angkawisittpan, Piyanat Jantosut, Noppadol Sangiamsak and Nopanom Kaewhanam
Eng 2024, 5(3), 1173-1182; https://doi.org/10.3390/eng5030064 - 26 Jun 2024
Abstract
This study investigates the correlation between the California Bearing Ratio (CBR) and the Dynamic Cone Penetrometer (DCP) for subgrade soil analysis. The paper aims to provide practical equations for predicting CBR values from DCP test results, therefore enhancing the efficiency of soil assessments
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This study investigates the correlation between the California Bearing Ratio (CBR) and the Dynamic Cone Penetrometer (DCP) for subgrade soil analysis. The paper aims to provide practical equations for predicting CBR values from DCP test results, therefore enhancing the efficiency of soil assessments in engineering practice. By analyzing test data and proposing correlations for different soil groups, the study introduces recalibrated correlations that demonstrate high accuracy in predicting CBR values. The newly proposed equations offer reliable predictions with values of 0.89, 0.92, and 0.94 for clean sand, silty sand or sandy silt, and cohesive soil, respectively. These correlations serve as valuable tools for engineers, enabling rapid and accurate CBR estimations for improved decision-making in various engineering projects.
Full article
(This article belongs to the Section Chemical, Civil and Environmental Engineering)
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Open AccessArticle
An Investigation of Increased Power Transmission Capabilities of Elastic–Plastic-Designed Press–Fit Connections Using a Detachable Joining Device
by
Jan Falter, Daniel Herburger, Hansgeorg Binz and Matthias Kreimeyer
Eng 2024, 5(3), 1155-1172; https://doi.org/10.3390/eng5030063 - 21 Jun 2024
Abstract
Drive systems are an important part of general mechanical engineering, automotive engineering, and various other fields, with shaft–hub connections being an important part of such systems. Decisive aspects in the development of such systems today are, for example, high transmittable forces and torques,
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Drive systems are an important part of general mechanical engineering, automotive engineering, and various other fields, with shaft–hub connections being an important part of such systems. Decisive aspects in the development of such systems today are, for example, high transmittable forces and torques, low masses, and the cheapest possible production of components. A possibly threefold increase in the force and torque transmission capacity can be achieved by using press–fit connections with an elastic–plastic design as opposed to regular elastically designed alternatives. An elastic–plastic design of the press–fit connection is achieved by using a large interference. A large transition geometry on the shaft (which replaces the conventional chamfer) is required to join such an interference. The material and space requirements have a negative impact on lightweight applications and limited building spaces. Therefore, the objective of the research presented in this paper is to design and analyze a detachable joining device that substitutes this geometry. A simulation study was conducted to determine the geometry of the joining device that improves the stress state and consequently the force and torque transmission capacity of the connection. Moreover, the influence of manufacturing tolerances of the joining device and the shaft, corresponding risks, and measures to mitigate them are analyzed using finite element analysis. The results show that large transition radii, enabled by using a joining device, lead to a homogenous distribution of plastic strain and pressure in the press–fit connection, even for large interferences ξ and soft hub materials like wrought aluminum alloys. The influence of manufacturing tolerances on the stress state was quantified, leading to design guidelines that minimize the risk of, e.g., the front face collision of a shaft and hub, while maximizing the power transmission of the connection. The results show the capability of a detachable joining device to enable elastic–plastic press–fit connections and the corresponding threefold increase in the force and torque transmission capacity in lightweight applications, resulting from the substitution of the installation space consuming and mass increasing the transition geometry of the shaft.
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(This article belongs to the Special Issue Feature Papers in Eng 2024)
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Open AccessArticle
Geotechnical Study for Assessing Slope Stability at the Proposed Weito Dam Site in Ethiopia: Implications for Environmental Sustainability and Resilience
by
Tadesse Demisie, Ephrem Getahun, Muralitharan Jothimani and Shengwen Qi
Eng 2024, 5(2), 1140-1154; https://doi.org/10.3390/eng5020062 - 20 Jun 2024
Abstract
There is a proposed dam at Weito in Ethiopia’s Southern Nations Nationalities and People Regional State. This embankment-type dam primarily serves irrigation purposes. Weito’s proposed dam’s slope stability is the primary focus of this investigation. The objective is to assess the geological and
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There is a proposed dam at Weito in Ethiopia’s Southern Nations Nationalities and People Regional State. This embankment-type dam primarily serves irrigation purposes. Weito’s proposed dam’s slope stability is the primary focus of this investigation. The objective is to assess the geological and geotechnical conditions influencing slope stability using the slope mass rating (SMR) classification system. This study examined various slope stability parameters. Uniaxial compressive strength, rock quality designation, joint condition, discontinuity spacing, joint orientation, and groundwater conditions were measured. An analysis of field data, including geological structures and lithology, was used to generate a structural discontinuity map. The slope mass rating was calculated to assess rock mass stability. The study area was examined for faults, joints, fractures, and shear zones during fieldwork. Schmidt hammer tests indicated a range of 10.5–50 MPa uniaxial compressive strength. Rock quality designation values were also within 72.5% to 95%. Additionally, the joint spacing of rocks varied from 3.95 cm to 47.5 cm. Rock mass ratings ranged from 39% to 62%. The study contributes to the understanding of the geological conditions at the Weito dam site and ensures the dam’s safe design and construction.
Full article
(This article belongs to the Section Chemical, Civil and Environmental Engineering)
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Open AccessArticle
Carbon Fiber-Reinforced Polymer Composites Integrated Beam–Column Joints with Improved Strength Performance against Seismic Events: Numerical Model Simulation
by
Noor Alhuda Sami Aljabbri, Abdulamir Atalla Karim and Fareed Hameed Majeed
Eng 2024, 5(2), 1112-1139; https://doi.org/10.3390/eng5020061 - 14 Jun 2024
Abstract
Strength enhancement of non-seismic concrete beam–column joints (NSCBCJs) via carbon fiber-reinforced polymer composites (CFRPCs) integration has become a viable strategy. However, the implementation of these NSCBCJs without transverse reinforcement shows poor performance during earthquakes in seismic locations. Thus, strengthening the anti-seismic performance of
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Strength enhancement of non-seismic concrete beam–column joints (NSCBCJs) via carbon fiber-reinforced polymer composites (CFRPCs) integration has become a viable strategy. However, the implementation of these NSCBCJs without transverse reinforcement shows poor performance during earthquakes in seismic locations. Thus, strengthening the anti-seismic performance of NSCBCJs to meet the acceptance criteria of ACI 374.1-05 is fundamentally significant. Yet, in addition to limited experimental results, only a few numerical studies based on the finite element model have been performed to determine the anti-seismic behavior of NSCBCJs. Consequently, the stress contribution of CFRPCs to NSCBCJs is not clearly understood. Therefore, we used a finite element model to examine the strength contribution of CFRPCs to NSCBCJs. The performance of the proposed finite element model was validated using the experimental results, demonstrating a good agreement between them. It was shown that the strength of NSCBCJs was improved due to CFRPC incorporation, thereby achieving compliance with the seismic requirements of ACI 374.1-05. In addition, CFRPCs presence could enhance the confinement, reduce the deformation of the NSCBCJs and, thus, decrease their stiffness and strength degradation, while simultaneously improving the energy dissipation.
Full article
(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)
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Open AccessArticle
Gasification of Lignocellulosic Waste in Supercritical Water: Study of Thermodynamic Equilibrium as a Nonlinear Programming Problem
by
Julles Mitoura dos Santos Junior and Adriano Pinto Mariano
Eng 2024, 5(2), 1096-1111; https://doi.org/10.3390/eng5020060 - 12 Jun 2024
Abstract
As one of the main industrial segments of the current geoeconomics scenario, agro-industrial activities generate excessive amounts of waste. The gasification of such waste using supercritical water (SCWG) has the potential to convert the waste and generate products with high added value, hydrogen
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As one of the main industrial segments of the current geoeconomics scenario, agro-industrial activities generate excessive amounts of waste. The gasification of such waste using supercritical water (SCWG) has the potential to convert the waste and generate products with high added value, hydrogen being the product of greatest interest. Within this context, this article presents studies on the SCWG processes of lignocellulosic residues from cotton, rice, and mustard husks. The Gibbs energy minimization (minG) and entropy maximization (maxS) approaches were applied to evaluate the processes conditioned in isothermal and adiabatic reactors, respectively. The thermodynamic and phase equilibria were written as a nonlinear programming problem using the Peng–Robinson state solution for the prediction of fugacity coefficients. As an optimization tool, TeS (Thermodynamic Equilibrium Simulation) software v.10 was used with the help of the trust-constr algorithm to search for the optimal point. The simulated results were validated with experimental data presenting surface coefficients greater than 0.99, validating the use of the proposed modeling to evaluate reaction systems of interest. It was found that increases in temperature and amounts of biomass in the process feed tend to maximize hydrogen formation. In addition to these variables, the H2/CO ratio is of interest considering that these processes can be directed toward the production of synthesis gas (syngas). The results indicated that the selected processes can be directed to the production of synthesis gas, including the production of chemicals such as methanol, dimethyl ether, and ammonia. Using an entropy maximization approach, it was possible to verify the thermal behavior of reaction systems. The maxS results indicated that the selected processes have a predominantly exothermic character. The initial temperature and biomass composition had predominant effects on the equilibrium temperature of the system. In summary, this work applied advanced optimization and modeling methodologies to validate the feasibility of SCWG processes in producing hydrogen and other valuable chemicals from agro-industrial waste.
Full article
(This article belongs to the Special Issue Sustainable and Green Technologies for Industrial Chemical Engineering)
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Open AccessArticle
Characterization of Pupillary Light Response through Low-Cost Pupillometry and Machine Learning Techniques
by
David A. Gutiérrez-Hernández, Miguel S. Gómez-Díaz, Francisco J. Casillas-Rodríguez and Emmanuel Ovalle-Magallanes
Eng 2024, 5(2), 1085-1095; https://doi.org/10.3390/eng5020059 - 7 Jun 2024
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This article employed pupillometry as a non-invasive technique to analyze pupillary light reflex (PLR) using LED flash stimuli. Particularly, for the experiments, only the red LED with a wavelength of 600 nm served as the light stimulation source. To stabilize the initial pupil
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This article employed pupillometry as a non-invasive technique to analyze pupillary light reflex (PLR) using LED flash stimuli. Particularly, for the experiments, only the red LED with a wavelength of 600 nm served as the light stimulation source. To stabilize the initial pupil size, a pre-stimulus (PRE) period of 3 s was implemented, followed by a 1 s stimulation period (ON) and a 4 s post-stimulus period (POST). Moreover, an experimental, low-cost pupillometer prototype was designed to capture pupillary images of 13 participants. The prototype consists of a 2-megapixel web camera and a lighting system comprising infrared and RGB LEDs for image capture in low-light conditions and stimulus induction, respectively. The study reveals several characteristic features for classifying the phenomenon, notably the mobility of Hjórth parameters, achieving classification percentages ranging from 97% to 99%, and offering novel insights into pattern recognition in pupillary activity. Moreover, the proposed device successfully captured the PLR from all the participants with zero reported incidents or health affectations.
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Open AccessArticle
Determination of Permanent Deformations of Non-Cohesive Soils in Pavement Structures under Repeated Traffic Load
by
Mate Janos Vamos and Janos Szendefy
Eng 2024, 5(2), 1067-1084; https://doi.org/10.3390/eng5020058 - 1 Jun 2024
Abstract
One of the main types of distress in pavement structures is rutting, which may also reduce serviceability significantly. Most design methods typically attribute rutting to the asphalt layer alone, proposing that it can be managed by controlling vertical deformation or stress at the
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One of the main types of distress in pavement structures is rutting, which may also reduce serviceability significantly. Most design methods typically attribute rutting to the asphalt layer alone, proposing that it can be managed by controlling vertical deformation or stress at the subgrade’s top. Furthermore, these methods frequently lack precise measurements for rut depth. On-site measurements show that the majority of permanent deformation occurs in the unbound layers beneath the asphalt; attention should be directed towards these layers. In recent literature, there are calculation methods that account for accumulating strains in soils. However, further investigation is needed regarding the effect of soil properties and the significance of the pavement cross-section. The literature is also somewhat contractionary regarding the origin of permanent deformations. In this research, the residual settlement of soils (base, subbase, and subgrade) under flexible pavement systems was analyzed due to the repeated traffic loads. Rut depths were calculated and analyzed using the High-Cycle Accumulation (HCA) model. The different behaviour in each course of the pavement system is discussed to reveal their contribution to total ruts. The effect of the grain size distribution of the subgrade was analyzed, and its significance on the rutting depths was demonstrated. Standardized pavement cross-sections with different asphalt thicknesses were evaluated, and the calculated settlements of the pavement originating from the ground during the design lifetime are also presented. It is shown that, with the same number of repetitions, the settlements calculated in each traffic load class are proportional to the thickness of the asphalt course. The contribution of the base, subbase, and subgrade courses to the total settlement is also presented for different subgrade types and traffic load classes.
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(This article belongs to the Section Chemical, Civil and Environmental Engineering)
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Open AccessArticle
Performance Evaluation of Self-Compacting Glass Fiber Concrete Incorporating Silica Fume at Elevated Temperatures
by
Hussein Kareem Sultan, Abbas Abdulhssein Abd Noor and Ghasan Fahim Huseien
Eng 2024, 5(2), 1043-1066; https://doi.org/10.3390/eng5020057 - 1 Jun 2024
Abstract
In this work, the properties of self-compacting concrete (SCC) and SCC containing 0.5 and 1% glass fibers (with lengths of 6 and 13 mm) were experimentally investigated, as well as their performance at high temperatures. With a heating rate of 5 °C/min, high-temperature
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In this work, the properties of self-compacting concrete (SCC) and SCC containing 0.5 and 1% glass fibers (with lengths of 6 and 13 mm) were experimentally investigated, as well as their performance at high temperatures. With a heating rate of 5 °C/min, high-temperature experiments were conducted at 200, 400, 600, and 800 °C to examine mass loss, spalling, and the remaining mechanical properties of SCC with and without glass fibers. According to the results of the flowability and passing ability tests, adding glass fibers does not affect how workable and self-compacting SCCs were. These findings also demonstrated that the mechanical properties of samples with and without glass fibers rose up to 200 °C but then decreased at 400 °C, whereas the mixture containing 0.5% glass fibers of a length of 13 mm displayed better mechanical properties. Both SCC samples with and without glass fibers remained intact at 200 °C. Some SCC samples displayed some corner and edge spalling when the temperature reached about 400 °C. Above 400 °C, a significant number of microcracks started to form. SCC samples quickly spalled and were completely destroyed between 600 and 800 °C. According to the results, glass fibers cannot stop SCC from spalling during a fire. Between 200 and 400 °C, there was no discernible mass loss. At 600 °C, mass loss starts to accelerate quickly, and it increased more than ten times beyond 200 °C. The ultrasonic pulse velocity (UPV) of SCC samples with glass fibers increased between room temperature and 200 °C, and the mixture containing 0.5% glass fibers of a length of 13 mm showed a somewhat higher UPV than other SCC mixtures until it started to decline at about 400 °C.
Full article
(This article belongs to the Special Issue Advances in Structural Analysis and Rehabilitation for Existing Structures)
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Open AccessArticle
Preparation of Injectable Dicalcium Phosphate Bone Cement for Potential Orthopedic Applications
by
Kholoud Jabar Wali, Ali Taha Saleh and Ghasan Fahim Huseien
Eng 2024, 5(2), 1028-1042; https://doi.org/10.3390/eng5020056 - 1 Jun 2024
Abstract
Various natural wastes can be promising for mining more valuable compounds if some specialized extraction techniques are adopted. Hydroxyapatite (HA) is a significant biomaterial that can be extracted from waste bovine bones by heating them at 700 °C and 900 °C. Based on
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Various natural wastes can be promising for mining more valuable compounds if some specialized extraction techniques are adopted. Hydroxyapatite (HA) is a significant biomaterial that can be extracted from waste bovine bones by heating them at 700 °C and 900 °C. Based on this idea, we made a novel dicalcium phosphate (DCP) bone cement (BC) by extracting HA via the reaction with monocalcium phosphate monohydrate (MCPM) and trisodium citrate. The setting time, injectability, and compressive strength (CS) of this DCPBC were examined using various analytical techniques, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) attached with energy-dispersive X-ray (EDX) spectroscopy, and Fourier-transformed infrared spectroscopy (FTIR). The phase composition, surface morphology, and chemical compositions of HA and DCP were evaluated. A Gillmore needle apparatus was used to measure the initial and final setting times of the specimens. The CS values of the prepared specimens were determined using INSTRON Series IX. The in vitro dissolution behavior of all samples was evaluated by immersing them in simulated body fluid (SBF) over 7 days at 37 °C. The final setting times of samples 3, 4, and 5 were 20, 24, and 18 min, respectively. In addition, the CS value of sample 1 before immersion in SBF was much lower (1.23 MPa) compared to sample 5 (21.79 MPa) after 7 days of immersion. The CS of the DCP after 3 days of immersion was increased to 33.75 MPa. The in vitro results for the dissolution and bioactivity of HA showed the highest degradation rate after 1 day of immersion and then decreased with the increase in the immersion duration. The HA layer thickness was considerably improved with longer incubation times. The proposed injectable DCP bone cement may have potential in future orthopedic applications.
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(This article belongs to the Special Issue Green Engineering for Sustainable Development 2024)
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Open AccessReview
A Review—Durability, Mechanical and Hygrothermal Behavior of Building Materials Incorporating Biomass
by
Houssam Affan, Badreddine El Haddaji, Soukaina Ajouguim and Fouzia Khadraoui
Eng 2024, 5(2), 992-1027; https://doi.org/10.3390/eng5020055 - 1 Jun 2024
Abstract
The growing importance of environmental efficiency in reducing carbon emissions has prompted scientists around the world to intensify their efforts to prevent the destructive effects of a changing climate and a warming planet. Global carbon emissions rose by more than 40% in 2021,
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The growing importance of environmental efficiency in reducing carbon emissions has prompted scientists around the world to intensify their efforts to prevent the destructive effects of a changing climate and a warming planet. Global carbon emissions rose by more than 40% in 2021, leading to significant variations in the planet’s weather patterns. Nevertheless, a significant proportion of natural resources continue to be exploited. To prepare for this challenge, it is essential to implement a sustainable approach in the construction industry. Biobased materials are made primarily from renewable raw materials like hemp, straw, miscanthus, and jute. These new materials provide excellent thermal and acoustic performance and make optimum use of local natural resources such as agricultural waste. Nowadays, cement is one of the most important construction materials. In an attempt to meet this exciting challenge, biobased materials with low-carbon binders are one of the proposed solutions to create a more insulating and less polluting material. The aim of this review is to investigate and to analyze the impact of the incorporation of different types of biobased materials on the mechanical, thermal, and hygric performance of a mix using different types of binder.
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(This article belongs to the Section Materials Engineering)
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Open AccessArticle
Efficient Reduction of Carbon Tetrachloride in an Electrochemical Reactor with a Three-Dimensional Electrode
by
Víctor M. Molina, Esteban Moreno-Toral and Antonio Ramos-Carrillo
Eng 2024, 5(2), 983-991; https://doi.org/10.3390/eng5020054 - 26 May 2024
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A selective electrochemical synthesis of chloroform from carbon tetrachloride (CT) in a laboratory-scale electrochemical reactor using a carbon felt three-dimensional electrode is studied. The characterization of the electrochemical reactor from the point of view of material transport was carried out, obtaining good correlations
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A selective electrochemical synthesis of chloroform from carbon tetrachloride (CT) in a laboratory-scale electrochemical reactor using a carbon felt three-dimensional electrode is studied. The characterization of the electrochemical reactor from the point of view of material transport was carried out, obtaining good correlations both in the adjustment to a simple bath reactor model and the adjustment to a piston-flow model, and the operating parameters were obtained, such as the material transport coefficient or the limiting intensity. The galvanostatic electrolysis of CT in the filter-press reactor obtained good values for current efficiency and selectivity, so that only hydrogen was obtained as a by-product. With respect to the use of flat electrodes, the three-dimensional carbon felt electrode improves the results in all the studied parameters under identical experimental conditions.
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Open AccessArticle
Assessing the Suitability of Automation Using the Methods–Time–Measurement Basic System
by
Malte Jakschik, Felix Endemann, Patrick Adler, Lennart Lamers and Bernd Kuhlenkötter
Eng 2024, 5(2), 967-982; https://doi.org/10.3390/eng5020053 - 24 May 2024
Abstract
Due to its high complexity and the varied assembly processes, hybrid assembly systems characterized by human–robot collaboration (HRC) are meaningful. Suitable use cases must be identified efficiently to ensure cost-effectiveness and successful deployment in the respective assembly systems. This paper presents a method
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Due to its high complexity and the varied assembly processes, hybrid assembly systems characterized by human–robot collaboration (HRC) are meaningful. Suitable use cases must be identified efficiently to ensure cost-effectiveness and successful deployment in the respective assembly systems. This paper presents a method for evaluating the potential of HRC to derive automation suitability based on existing or to-be-collected time data. This should enable a quick and favorable statement to be made about processes, for efficient application in potential analyses. The method is based on the Methods–Time–Measurement Basic System (MTM-1) procedure, widely used in the industry. This ensures good adaptability in an industrial context. It extends existing models and examines how much assembly activities and processes can be optimized by efficiently allocating between humans and robots. In the process model, the assembly processes are subdivided and analyzed with the help of the specified MTM motion time system. The suitability of the individual activities and sub-processes for automation are evaluated based on criteria derived from existing methods. Two four-field matrices were used to interpret and classify the analysis results. The process is assessed using an example product from electrolyzer production, which is currently mainly assembled by hand. To achieve high statement reliability, further work is required to classify the results comprehensively.
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(This article belongs to the Special Issue Feature Papers in Eng 2024)
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Open AccessArticle
Innovative Integration of Triboelectric Nanogenerators into Signature Stamps for Energy Harvesting, Self-Powered Electronic Devices, and Smart Applications
by
Lakshakoti Bochu, Supraja Potu, Madathil Navaneeth, Uday Kumar Khanapuram, Rakesh Kumar Rajaboina and Prakash Kodali
Eng 2024, 5(2), 958-966; https://doi.org/10.3390/eng5020052 - 23 May 2024
Abstract
In this manuscript, we present a novel approach for integrating Triboelectric Nanogenerators (TENGs) into signature stamps, termed Stamp TENG (S-TENG). We have modified a commercially available stamp holder to integrate triboelectric layers for multiple applications like effective energy harvesting, sensing, and embedded electronics
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In this manuscript, we present a novel approach for integrating Triboelectric Nanogenerators (TENGs) into signature stamps, termed Stamp TENG (S-TENG). We have modified a commercially available stamp holder to integrate triboelectric layers for multiple applications like effective energy harvesting, sensing, and embedded electronics for data prediction. S-TENG has been further explored in remote monitoring systems for elderly individuals and for gathering real-time statistics regarding persons or events at specific locations. The S-TENG is fabricated using FEP and Al as functional layers. It demonstrates an output voltage of 310 V, a current of 165 μA, and a power density of 14.8 W/m2. The simplicity of the S-TENG’s design is noteworthy. Its ability to generate energy through simple, repetitive stam** actions, which anyone can perform without specialized training, stands out as a key feature. The device is also designed for ease of use, being handheld and user-friendly. Its flexible and adaptable structure ensures that individuals with varying physical capabilities can comfortably operate it. An impressive capability of the TENG is its ability to illuminate 320 LEDs with each stamp press momentarily. Furthermore, using energy management circuits, the S-TENG can power small electronic gadgets such as digital watches and thermometers for a few seconds. In addition, when integrated with electronics, the S-TENG shows great potential in data prediction for various practical applications.
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(This article belongs to the Section Electrical and Electronic Engineering)
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Open AccessArticle
NACA 2412 Drag Reduction Using V-Shaped Riblets
by
Smitha Mol Selvanose, Siva Marimuthu, Abdul Waheed Awan and Kamran Daniel
Eng 2024, 5(2), 944-957; https://doi.org/10.3390/eng5020051 - 23 May 2024
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This research focuses on addressing a significant concern in the aviation industry, which is drag. The primary objective of this project is to achieve drag reduction through the implementation of riblets on a wing featuring the NACA 2412 aerofoil, operating at subsonic speeds.
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This research focuses on addressing a significant concern in the aviation industry, which is drag. The primary objective of this project is to achieve drag reduction through the implementation of riblets on a wing featuring the NACA 2412 aerofoil, operating at subsonic speeds. Riblets, with the flow direction on wing surfaces, have demonstrated the potential to effectively decrease drag in diverse applications. This investigation includes computational analysis within the ANSYS Workbench framework, employing a polyhedral mesh model. The scope of this research encompasses the analysis of both a conventional wing and a modified wing with riblets. A comparative analysis is conducted to assess variations in drag values between the two configurations. Parameters, including geometry, dimensions, and riblet placement at varying angles of attack, are explored to comprehend their impact on drag reduction. Notably, 15.6% and 23% reductions in drag were identified at a 16-degree angle of attack with midspan and three-riblet models, separately. The computational mesh and method were validated using appropriate techniques.
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Open AccessArticle
Novel Synthesis of Nanocalcite from Phosphogypsum and Cesium Carbonate: Control and Optimization of Particle Size
by
Meryem Bensemlali, Badreddine Hatimi, Asmae Sanad, Layla El Gaini, Meryeme Joudi, Najoua Labjar, Hamid Nasrellah, Abdellatif Aarfane and Mina Bakasse
Eng 2024, 5(2), 932-943; https://doi.org/10.3390/eng5020050 - 21 May 2024
Abstract
This study investigates a controlled synthesis and particle size optimization of nanocalcite particles using phosphogypsum, a waste byproduct from the phosphate fertilizer industry, and cesium carbonate (Cs2CO3), a common carbonate source. The effects of synthesis parameters, including temperature and
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This study investigates a controlled synthesis and particle size optimization of nanocalcite particles using phosphogypsum, a waste byproduct from the phosphate fertilizer industry, and cesium carbonate (Cs2CO3), a common carbonate source. The effects of synthesis parameters, including temperature and pH, on the size, morphology, and crystallinity of the synthesized nanocalcite particles were systematically examined. The optimized synthesis conditions for obtaining nanocalcite particles with desired properties are discussed. The synthesized nanocalcite particles were characterized using various techniques, such as XRD, FTIR, and SEM, to analyze their crystal structure, morphology, and elemental composition. Particle sizes were determined using the Debye–Scherrer method, and accordingly, nanometric sizes were achieved. The potential applications of the synthesized nanocalcite particles in cementitious materials, agriculture, and drug delivery are highlighted. This research provides valuable insights into the sustainable synthesis and size optimization of nanocalcite particles from phosphogypsum and Cs2CO3 at a controlled temperature and pH.
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(This article belongs to the Section Materials Engineering)
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Open AccessArticle
Process-Driven Layout Optimization of a Portable Hybrid Manufacturing Robotic Cell Structure
by
Harry Bikas, Dimitrios Manitaras, Thanassis Souflas and Panagiotis Stavropoulos
Eng 2024, 5(2), 918-931; https://doi.org/10.3390/eng5020049 - 20 May 2024
Abstract
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Hybrid manufacturing combines manufacturing processes (typically additive manufacturing and machining) exploiting the benefits of each and enabling repair scenarios. Such an approach can be integrated with a robot, and if made portable, can form a flexible machine tool that can be easily transported
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Hybrid manufacturing combines manufacturing processes (typically additive manufacturing and machining) exploiting the benefits of each and enabling repair scenarios. Such an approach can be integrated with a robot, and if made portable, can form a flexible machine tool that can be easily transported anywhere to enable repairs in the field. However, the design of the load-bearing structure determines its transportability, and its stiffness plays a crucial functional role under dynamic loads and affects the product quality. Finding the right balance between weight and stiffness requires accurate boundary conditions and an effective design. In this work, a method is proposed towards process-driven optimization of a portable manufacturing cell structure. The dynamic cutting forces are determined through a machining process model and, via a simplified model of the robot arm, the forces at the base of the robot are estimated. Since the frame consists of beams, the layout optimization method is applied, using the estimated process forces as boundary conditions to optimize the arrangement of beams. The proposed method achieved 0.05 mm displacement in the load-bearing structure under milling and an acceptable accuracy of the position of a hole’s center during drilling, while the overall weight reduced by 17.6%.
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Open AccessArticle
An Efficient Approach for Damage Identification of Beams Using Mid-Span Static Deflection Changes
by
Quoc-Bao Nguyen and Huu-Hue Nguyen
Eng 2024, 5(2), 895-917; https://doi.org/10.3390/eng5020048 - 20 May 2024
Abstract
In structural health monitoring, determining the location and index of damage is a critical task in order to ensure the safe operation of the construction project and to enable the early recovery of losses. This paper presents a novel method for identifying damage
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In structural health monitoring, determining the location and index of damage is a critical task in order to ensure the safe operation of the construction project and to enable the early recovery of losses. This paper presents a novel method for identifying damage location and damage index in simply supported (SS) beams by analyzing deflection changes at the mid-span point. Theoretical equations for mid-span deflection of simply supported beams with local damage are derived based on the principle of Virtual Work. Utilizing mid-span deflection, formulas for deflection change (DC) between two structural states, along with the first and second derivatives of DC at the mid-span point, are developed. The method of determining the location and damage index is then extended from intact beams to cases of beams with multiple damage zones and from damaged beams to beams with new failures. The graphical analysis of these quantities facilitates the determination of the number, location, and index of new damages. Various case studies on simply supported beams, involving one, two, and four damage zones at different positions and with varying damage indexes, are examined. The comparison of the theoretical method with the numerical simulations using Midas FEA NX 2020 (v1.1) software yields consistent results, affirming the accuracy and efficacy of the proposed approach in identifying and determining the damage locations as well as the damage indices.
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(This article belongs to the Section Chemical, Civil and Environmental Engineering)
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