Journal Description
Designs
Designs
is an international, peer-reviewed, open access journal of engineering designs published bimonthly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High visibility: indexed within Scopus, Inspec, and other databases.
- Journal Rank: CiteScore - Q2 (Engineering (miscellaneous))
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 15.2 days after submission; acceptance to publication is undertaken in 3.8 days (median values for papers published in this journal in the first half of 2024).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Latest Articles
An Approach for Predicting the Lifetime of Lead-Free Soldered Electronic Components: Hitachi Rail STS Case Study
Designs 2024, 8(4), 74; https://doi.org/10.3390/designs8040074 - 26 Jul 2024
Abstract
Throughout much of the 20th century, Sn–Pb solder dominated electronics. However, environmental and health concerns have driven the adoption of lead-free alternatives. Since 2006, legislation such as the European Union’s RoHS Directive has mandated lead-free solder in most electronic devices, prompting extensive research
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Throughout much of the 20th century, Sn–Pb solder dominated electronics. However, environmental and health concerns have driven the adoption of lead-free alternatives. Since 2006, legislation such as the European Union’s RoHS Directive has mandated lead-free solder in most electronic devices, prompting extensive research into high-performance substitutes. Lead-free solders offer advantages such as reduced environmental impact and improved reliability but replacing Sn–Pb presents challenges in areas like melting point and wetting ability. This transition is primarily motivated by a focus on protecting environmental and human health, while ensuring equal or even improved reliability. Research has explored lead-free solder’s mechanical properties, microstructure, wettability, and reliability. However, there is a notable lack of studies on its long-term performance and lifetime influence. To address this gap, mathematical models are used to predict intermetallic bond evolution from process conditions, validated with experimental tests. This study contributes by extending these models to predict bond evolution under typical operating conditions of devices and comparing the predictions with actual intermetallic thickness values found through metallographic sections.
Full article
(This article belongs to the Special Issue Mixture of Human and Machine Intelligence in Digital Manufacturing)
Open AccessArticle
Design of an Innovative Twin-Disc Device for the Evaluation of Wheel and Rail Profile Wear
by
Matteo Magelli, Rosario Pagano and Nicolò Zampieri
Designs 2024, 8(4), 73; https://doi.org/10.3390/designs8040073 - 26 Jul 2024
Abstract
The tribological properties of steels used to realise railway wheels play a fundamental role in the performances of both vehicle and infrastructure. In particular, the wear process, caused by the wheel–rail interaction, modifies the shape of wheel and rail profiles, changing the performances
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The tribological properties of steels used to realise railway wheels play a fundamental role in the performances of both vehicle and infrastructure. In particular, the wear process, caused by the wheel–rail interaction, modifies the shape of wheel and rail profiles, changing the performances of the vehicle. For this reason, research institutes and vehicle manufacturers have worked hard to develop predictive tools able to estimate the evolution of the wheel and rail profiles. The efficiency of these tools is strongly influenced by the tribological properties of the materials, i.e., the wear coefficients, which are used as input data. The characterisation of these properties requires specific tools and long-lasting experimental campaigns, which are usually performed under controlled operating conditions, using twin-disc test benches. These devices usually do not consider the real contact conditions in terms of normal load, contact geometry, and slip velocity, since they are equipped with small-size rollers. The paper proposes an innovative 1:5 scaled twin-disc, which allows the reproduction of the real wheel–rail contact conditions, thanks to Pascal’s scaling technique. The testing device allows the reproduction of a wide range of typical operating conditions of railway vehicles, thanks to high-power independent brushless motors, used to actuate the rollers, and an innovative loading system.
Full article
(This article belongs to the Section Vehicle Engineering Design)
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Open AccessArticle
Optimized Floating Offshore Wind Turbine Substructure Design Trends for 10–30 MW Turbines in Low-, Medium-, and High-Severity Wave Environments
by
Joseph Habib Dagher, Andrew J. Goupee and Anthony M. Viselli
Designs 2024, 8(4), 72; https://doi.org/10.3390/designs8040072 - 18 Jul 2024
Abstract
Floating offshore wind is a promising renewable energy source, as 60% of the wind resources globally are found at depths requiring floating technologies, it minimizes construction at sea, and provides opportunities for industrialization given a lower site dependency. While floating offshore wind has
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Floating offshore wind is a promising renewable energy source, as 60% of the wind resources globally are found at depths requiring floating technologies, it minimizes construction at sea, and provides opportunities for industrialization given a lower site dependency. While floating offshore wind has numerous advantages, a current obstacle is its cost in comparison to more established energy sources. One cost-reduction approach for floating wind is increasing turbine capacities, which minimizes the amount of foundations, moorings, cables, and O&M equipment. This work presents trends in mass-optimized VolturnUS hull designs as turbine capacity increases for various wave environments. To do this, a novel rapid hull optimization framework is presented that employs frequency domain modeling, estimations of statistical extreme responses, industry constructability requirements, and genetic algorithm optimization to generate preliminary mass-optimal VolturnUS hull designs for a given turbine design and set of site conditions. Using this framework, mass-optimized VolturnUS hull designs were generated for 10–30 MW turbines for wave environments of varying severities. These design studies show that scaling up turbine capacities increases the mass efficiency of substructure designs, with decreasing returns, throughout the examined turbine capacity range. Additionally, increased wave environment severity is shown to increase the required mass of a given substructure design.
Full article
(This article belongs to the Special Issue Design and Analysis of Offshore Wind Turbines)
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Open AccessArticle
Mechanical Transmissions with Convex–Concave Multipair Contact of Teeth in Precessional Gearing
by
Viorel Bostan, Ion Bostan and Maxim Vaculenco
Designs 2024, 8(4), 71; https://doi.org/10.3390/designs8040071 - 11 Jul 2024
Abstract
In this study, we propose a new toothed gear for mechanical transmissions built from a satellite wheel with two toothed conical crowns, one of which conjugates with a fixed central conical wheel mounted in the transmission housing and the other with a movable
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In this study, we propose a new toothed gear for mechanical transmissions built from a satellite wheel with two toothed conical crowns, one of which conjugates with a fixed central conical wheel mounted in the transmission housing and the other with a movable conical wheel installed on the flange of the driven shaft. The satellite wheel is mounted on the inclined portion of the crankshaft and performs spherospatial motion around a fixed point. When the crankshaft rotates, the teeth of the wheels engage with spherospatial interaction in two lateral gearings of the satellite wheel, yielding kinematic ratios dependent on the correlation of the number of teeth. The teeth of the satellite wheel are used with circular arc profiles, and the teeth of the central wheel have flank profiles with variable curvatures increasing continuously from the root to the tip, so that, in meshing, the teeth form multipair contacts with convex–concave geometry with a small difference in flank curvatures. The flank profile geometry and pairs of teeth simultaneously engage depending on the configurational parameters of the gearing and can use up to 100% of pairs of simultaneously conjugated teeth.
Full article
(This article belongs to the Section Mechanical Engineering Design)
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Open AccessArticle
Design and Operational Assessment of a Railroad Track Robot for Railcar Undercarriage Condition Inspection
by
James Kasch and Mehdi Ahmadian
Designs 2024, 8(4), 70; https://doi.org/10.3390/designs8040070 - 10 Jul 2024
Abstract
The operational effectiveness of a railroad track robot that is designed for railcar undercarriage inspection is provided. Beyond describing the robot’s design details and onboard imaging system, the paper analyzes the recorded video images and offers design improvements to increase their clarity. The
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The operational effectiveness of a railroad track robot that is designed for railcar undercarriage inspection is provided. Beyond describing the robot’s design details and onboard imaging system, the paper analyzes the recorded video images and offers design improvements to increase their clarity. The robot is designed to be deployed trackside, traverse over the rails, and then maneuver in between the rails beneath a stopped train in a siding or a railyard. The under-carriage conditions are documented by onboard video cameras for automated or manual postprocessing. The intent is to inspect the components that are not visible to the conductor or train inspector during a walk-along inspection of a stationary train. An assessment of the existing design, followed by modification and validation, is presented. The results from a prototype unit developed by the Railway Technologies Laboratory at Virginia Tech (RTL) indicate that with proper positioning of off-the-shelf imaging systems such as cameras manufactured by GoPro® in San Mateo, CA, USA and appropriate lighting, it is possible to capture videos that are sufficiently clear for manual (by a railroad engineer), semi-automated, or fully automated (using Artificial Intelligence or Machine Learning methods) inspections of rolling stock undercarriages. Additionally, improvements to the control, mobility, and reliability of the system are documented, although reliability throughout operation and the ability to consistently climb out of the track bed remain points of future investigation.
Full article
(This article belongs to the Special Issue Advancements in Robotic Design, Manufacturing, and the Action-Perception Loop)
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Open AccessArticle
Computational Investigation of the Fluidic Properties of Triply Periodic Minimal Surface (TPMS) Structures in Tissue Engineering
by
Muhammad Noman Shahid, Muhammad Usman Shahid, Shummaila Rasheed, Muhammad Irfan and Muhannad Ahmed Obeidi
Designs 2024, 8(4), 69; https://doi.org/10.3390/designs8040069 - 10 Jul 2024
Abstract
Tissue engineering, a rapidly advancing field in medicine, has made significant strides with the development of artificial tissue substitutes to meet the growing need for organ transplants. Three-dimensional (3D) porous scaffolds are widely utilized in tissue engineering, especially in orthopedic surgery. This study
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Tissue engineering, a rapidly advancing field in medicine, has made significant strides with the development of artificial tissue substitutes to meet the growing need for organ transplants. Three-dimensional (3D) porous scaffolds are widely utilized in tissue engineering, especially in orthopedic surgery. This study investigated the fluidic properties of diamond and gyroid structures with varying porosity levels (50–80%) using Computational Fluid Dynamics (CFD) analysis. The pressure and velocity distributions were analyzed, and it was observed that the pressure decreased gradually, whereas the velocity increased in the central area of the surface structures. Specifically, the pressure drop ranged from 2.079 to 0.984 Pa for the diamond structure and from 1.669 to 0.943 Pa for the gyroid structure as the porosity increased from 50% to 80%. It was also found that the permeability increased as the porosity level increased, with values ranging from to for the diamond structure and from to for the gyroid structure. The wall shear stress (WSS) was also analyzed, showing a consistent decrease with increased porosity for both types of structures, with WSS values ranging from to for the diamond structure and from to for the gyroid structure. Overall, this study provides insights into the fluidic properties of diamond and gyroid structures, which can be useful in various applications such as tissue engineering.
Full article
(This article belongs to the Special Issue Post-manufacturing Testing and Characterization of Materials)
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Open AccessArticle
Mapping the Potential of Zero-Energy Building in Greece Using Roof Photovoltaics
by
Angeliki Kitsopoulou, Dimitris Pallantzas, Evangelos Bellos and Christos Tzivanidis
Designs 2024, 8(4), 68; https://doi.org/10.3390/designs8040068 - 4 Jul 2024
Abstract
The present study investigates the incorporation of renewable rooftop photovoltaic systems in fully electrified residential buildings and estimates the zero-energy demand building potential in relation to the climatic data of Greece. Specifically, the aim of the analysis is to calculate the maximum possible
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The present study investigates the incorporation of renewable rooftop photovoltaic systems in fully electrified residential buildings and estimates the zero-energy demand building potential in relation to the climatic data of Greece. Specifically, the aim of the analysis is to calculate the maximum possible number of stories and therefore the total building height for a complete transformation to zero-net-energy building. The energy analysis, which is conducted using the DesignBuilder software, focuses on single-floor up to seven-story buildings. The importance of the present work lies in the acknowledgment of the diversity of the Greek residential sector, the adherence to national energy policies, and the European goal of fully electrified buildings. The examined case studies are equipped with electrically driven air-to-air heat pumps serving the space heating and cooling demands and with an air-to-water heat pump covering the domestic hot water requirements. The investigated locations are the four main cities of Greece, Athens, Thessaloniki, Chania, and Kastoria, which represent the country’s four climatic categories. The conducted analysis allows for the mapping of the zero-energy building potential for the climatic data of Greece, demonstrating the possibility of striking a positive building energy balance through the integration of on-site renewable energy sources and the production of necessary electrical energy. The novelty of the present work lies in the identification of a key factor, namely, the building height, which determines the feasibility of transforming multifamily buildings into zero-energy buildings. According to the analysis results, the critical number of stories is calculated at six for Chania, five for Athens, four for Thessaloniki, and two for Kastoria. Regarding a three-story residential building, the incorporation of a renewable photovoltaic system can result in an annual surplus electricity production of 13,741 kWh (Chania), 10,424 kWh (Athens), and 6931 kWh (Thessaloniki), and a corresponding coverage of 100% (Chania), 69.0% (Athens), 38.9% (Thessaloniki) and 0% (Kastoria).
Full article
(This article belongs to the Special Issue Design and Applications of Positive Energy Districts)
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Open AccessArticle
Designs of Miniature Optomechanical Sensors for Measurements of Acceleration with Frequencies of Hundreds of Hertz
by
Marina Rezinkina and Claus Braxmaier
Designs 2024, 8(4), 67; https://doi.org/10.3390/designs8040067 - 4 Jul 2024
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Some applications, such as aerospace testing and monitoring the operating conditions of equipment on space missions, require mechanical sensors capable of measuring accelerations at frequencies of several hundred hertz. For such measurements, optomechanical sensors can be used, providing the ability to measure accelerations
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Some applications, such as aerospace testing and monitoring the operating conditions of equipment on space missions, require mechanical sensors capable of measuring accelerations at frequencies of several hundred hertz. For such measurements, optomechanical sensors can be used, providing the ability to measure accelerations without calibration. To enable such measurements, improved designs of drum-type sensors with the assigned performance have been elaborated. Such designs make it possible to provide the necessary levels of natural frequencies for optomechanical sensors and eliminate crosstalk. Using mathematical modeling, the dependencies of the mechanical characteristics of the proposed types of acceleration sensors versus their parameters were obtained. The use of such sensor designs ensures their compactness, making their manufacturing more technologically sound and suitable for use, in particular, in space missions.
Full article
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Open AccessArticle
Marine Applications and Design of High-Efficiency Small-Scale Gas Turbines
by
Dario Barsi, Luciano Frezza, Francesca Satta, Yigang Luan and Pietro Zunino
Designs 2024, 8(4), 66; https://doi.org/10.3390/designs8040066 - 28 Jun 2024
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In today’s era of heightened environmental awareness, industries and means of transport are under increasing pressure to minimize their ecological footprint. In particular, small-scale power plants for the marine sector pose environmental challenges due to their pollutant emissions. One promising technology to address
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In today’s era of heightened environmental awareness, industries and means of transport are under increasing pressure to minimize their ecological footprint. In particular, small-scale power plants for the marine sector pose environmental challenges due to their pollutant emissions. One promising technology to address this purpose is represented by small-scale gas turbines. In this work, the design of a radial turbine and a centrifugal compressor for a 5 MW engine to be employed onboard ships is developed. After a one-dimensional design, the project involves the aerodynamic and structural design optimization of the two machines using fluid dynamic and structural simulation software. The final configuration obtained by the optimization process and its performance are analyzed, demonstrating that the use of a radial architecture for the construction of a 5 MW small gas-turbine assembly for marine propulsion is feasible. Both the compressor and the turbine optimization procedures led to final values of polytropic efficiencies that were three percentage points larger than the first-guess design machine values, simultaneously allowing for reductions in stress usage factors by more than 38% and 32% for the compressor and the turbine, respectively.
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Open AccessEditorial
Biomaterials Design for Human Body Repair
by
Richard Drevet and Hicham Benhayoune
Designs 2024, 8(4), 65; https://doi.org/10.3390/designs8040065 - 27 Jun 2024
Abstract
The global clinical demand for biomaterials is constantly increasing due to the aging population [...]
Full article
(This article belongs to the Collection Editorial Board Members’ Collection Series: Biomaterials Design)
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Open AccessArticle
A Novel Tire and Road Testing Bench for Modern Automotive Needs
by
Francesco Favilli, Michele Sgamma, Francesco Bucchi, Francesco Frendo, Pietro Leandri and Massimo Losa
Designs 2024, 8(4), 64; https://doi.org/10.3390/designs8040064 - 24 Jun 2024
Abstract
The automotive industry is currently transforming, primarily due to the rise of electric and hybrid vehicle technologies and the need to reduce vehicle mass and energy losses to decrease consumption, pollution, and raw material usage. Additionally, road surface manufacturers emphasize improving pavement durability
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The automotive industry is currently transforming, primarily due to the rise of electric and hybrid vehicle technologies and the need to reduce vehicle mass and energy losses to decrease consumption, pollution, and raw material usage. Additionally, road surface manufacturers emphasize improving pavement durability and reducing rolling noise. This necessitates precise load condition definitions and drives the need for reliable wheel testing benches. Many current benches use abrasive-coated rollers or synthetic tapes, but devices capable of testing on actual road surfaces are rare. In this work, a novel device for testing tire-pavement interaction is proposed. The system features a cart moving along a closed-track platform, ensuring test repeatability and enabling structural durability tests on uneven surfaces with installed obstacles. The cart is equipped with a cantilever arm capable of supporting either a testing wheel with customizable dimensions and kinematic parameters or a tire integrated with a complete suspension system, moving along a customizable pavement surface. The system includes actuators and sensors for applying vertical loads and adjusting the alignment of the testing wheel (slip angle, camber angle, etc.), allowing the characterization of tire behavior such as wear, fatigue, rolling noise, and rolling resistance. Multibody simulations were performed to evaluate the bench’s feasibility in terms of kinematics, power requirements, and structural loads. Results confirmed how this novel test bench represents a promising advancement in tire testing capabilities, enabling comprehensive studies on tire performance, noise reduction, and the structural dynamics of vehicle subsystems.
Full article
(This article belongs to the Section Vehicle Engineering Design)
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Open AccessArticle
Design and Implementation of a Low-Power Device for Non-Invasive Blood Glucose
by
Luis Miguel Pires and José Martins
Designs 2024, 8(4), 63; https://doi.org/10.3390/designs8040063 - 24 Jun 2024
Abstract
Glucose is a simple sugar molecule. The chemical formula of this sugar molecule is C6H12O6. This means that the glucose molecule contains six carbon atoms (C), twelve hydrogen atoms (H), and six oxygen atoms (O). In human
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Glucose is a simple sugar molecule. The chemical formula of this sugar molecule is C6H12O6. This means that the glucose molecule contains six carbon atoms (C), twelve hydrogen atoms (H), and six oxygen atoms (O). In human blood, the molecule glucose circulates as blood sugar. Normally, after eating or drinking, our bodies break down the sugars in food and use them to obtain energy for our cells. To execute this process, our pancreas produces insulin. Insulin “pulls” sugar from the blood and puts it into the cells for use. If someone has diabetes, their pancreas cannot produce enough insulin. As a result, the level of glucose in their blood rises. This can lead to many potential complications, including blindness, disease, nerve damage, amputation, stroke, heart attack, damage to blood vessels, etc. In this study, a non-invasive and therefore easily usable method for monitoring blood glucose was developed. With the experiment carried out, it was possible to measure glucose levels continuously, thus eliminating the disadvantages of invasive systems. Near-IR sensors (optical sensors) were used to estimate the concentration of glucose in blood; these sensors have a wavelength of 940 nm. The sensor was placed on a small black parallelepiped-shaped box on the tip of the finger and the output of the optical sensor was then connected to a microcontroller at the analogue input. Another sensor used, but only to provide more medical information, was the heartbeat sensor, inserted into an armband (along with the microprocessor). After processing and linear regression analysis, the glucose level was predicted, and data were sent via the Bluetooth network to a developed APP. The results of the implemented device were compared with available invasive methods (commercial products). The hardware consisted of a microcontroller, a near-IR optical sensor, a heartbeat sensor, and a Bluetooth module. Another objective of this experiment using low-cost and low-power hardware was to not carry out complex processing of data from the sensors. Our practical laboratory experiment resulted in an error of 2.86 per cent when compared to a commercial product, with a hardware cost of EUR 8 and a consumption of 50 mA.
Full article
(This article belongs to the Collection Editorial Board Members’ Collection Series: Biomaterials Design)
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Open AccessArticle
Printed Primary Battery in a Rolled-Up Form Factor
by
Andreas Willert, Sven Voigt, Tobias Zschau and Ralf Zichner
Designs 2024, 8(4), 62; https://doi.org/10.3390/designs8040062 - 21 Jun 2024
Abstract
In battery systems, there are several established form factors targeting mass market applications, like D, C, AA, AAA series, lithium round cells, and coin cells. Besides these standardized batteries, in printed electronics, there are several approaches to realize flat batteries of different material
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In battery systems, there are several established form factors targeting mass market applications, like D, C, AA, AAA series, lithium round cells, and coin cells. Besides these standardized batteries, in printed electronics, there are several approaches to realize flat batteries of different material systems fabricating primary and secondary battery types. For a dedicated application in agriculture, a sensor system requires a degradable primary battery. In this paper, the development of a dedicated zinc–carbon battery is described, supplying the sensor application with 4.5 Vnom. The battery has a 170 mm length and a 23 mm outer diameter. while the inner core is open for the antenna system of the application. The active area is up to 161 cm2. The design and manufacturing aspects are described. The rolled-up battery system is fully charged after manufacturing and ready to operate. It may remain inside the degradable sensor system after use in the field.
Full article
(This article belongs to the Section Smart Manufacturing System Design)
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Open AccessArticle
Optimising Lead–Air Battery Performance through Innovative Open-Cell Foam Anodes
by
Amel Hind Hassein-Bey, Abd-Elmouneïm Belhadj, Selma Toumi, Hichem Tahraoui, Mohammed Kebir, Abdeltif Amrane, Derradji Chebli, Abdallah Bouguettoucha, Meriem Zamouche and Jie Zhang
Designs 2024, 8(4), 61; https://doi.org/10.3390/designs8040061 - 21 Jun 2024
Abstract
In the dynamic realm of sustainable energy storage technologies, the global research landscape presents myriad scientific and economic challenges. The erratic growth of renewable energies alongside the phasing out of conventional power plants poses a significant hurdle in maintaining a stable balance between
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In the dynamic realm of sustainable energy storage technologies, the global research landscape presents myriad scientific and economic challenges. The erratic growth of renewable energies alongside the phasing out of conventional power plants poses a significant hurdle in maintaining a stable balance between energy supply and demand. Consequently, energy storage solutions play a pivotal role in mitigating substantial fluctuations in demand. Metal–air batteries, distinguished by their superior energy density and enhanced safety profile compared to other storage devices, emerge as promising solutions. Leveraging the well-established lead–acid battery technology, this study introduces a novel approach utilising open-cell foam manufactured through the Excess Salt Replication process as an anode for lead–air battery cells. This innovation not only conserves lead but also reduces battery weight. By employing a 25% antimonial lead alloy, open-cell foams with diameters ranging from 2 mm to 5 mm were fabricated for the antimonial lead–air battery. Preliminary findings suggest that the effective electrical conductivity of primary battery cells, measured experimentally, surpasses that of cells composed of the same dense, non-porous antimonial lead alloy. This improvement is primarily attributed to their extensive specific surface area, facilitating oxidation–reduction reactions. A correlation between effective electrical conductivity and cell diameter is established, indicating optimal conductivity achieved with a 5 mm cell diameter. These results underscore the feasibility of implementing such an electrical system.
Full article
(This article belongs to the Special Issue Design and Manufacture of Electric Vehicles)
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Open AccessArticle
Design and Application of Low-Temperature Geothermal Thermoelectric Power Generation (Lotemg–TPG) in Sari Ater Hot Spring, Ciater, Subang, West Java, Indonesia
by
Harapan Marpaung, Supriyadi, Ni Ketut Lasmi, Alamta Singarimbun and Wahyu Srigutomo
Designs 2024, 8(3), 60; https://doi.org/10.3390/designs8030060 - 17 Jun 2024
Abstract
The use of surface geothermal manifestations in Indonesia is still very limited as a tourist attraction. Solid-state thermoelectric generator technology is an alternative to converting electrical energy directly from a heat source in the form of low-temperature geothermal manifestation. Low-temperature geothermal thermoelectric power
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The use of surface geothermal manifestations in Indonesia is still very limited as a tourist attraction. Solid-state thermoelectric generator technology is an alternative to converting electrical energy directly from a heat source in the form of low-temperature geothermal manifestation. Low-temperature geothermal thermoelectric power generation (Lotemg–TPG) was designed, manufactured, and tested to take advantage of this opportunity. It was also applied to the Sari Ater Hot Spring, Ciater. The Lotemg–TPG unit comprises seven M8T modules in two frame blocks equipped with hot- and cold-water circulation channels. The M8T module is the main part of the Lotemg–TPG, which consists of eight TEG elements of type TEG1-241-1.4-1.2, flanked by a hot-side radiator and a cold-side radiator. The measurement results showed that at the temperature difference between the hot-side Th and the cold-side Tc of ∆T 17.38 °C, one module can produce 1.30 W of power, so the total power of the Lotemg–TPG unit is around 9.10 W. This result is quite good considering that the heat source is obtained for free, and the device can operate to produce stable electrical power.
Full article
(This article belongs to the Collection Editorial Board Members’ Collection Series: Smart Energy Systems Design)
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Open AccessArticle
Requirements and Characteristics for the Development and Selection of Design Methods
by
Johannes Matschewsky, Sergio A. Brambila-Macias, Abhijna Neramballi and Tomohiko Sakao
Designs 2024, 8(3), 59; https://doi.org/10.3390/designs8030059 - 14 Jun 2024
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While many design methods are developed, tested and reported in the literature, their utilization in industry practice remains low. Design methods are receiving substantial scholarly focus and are considered central to efficiently achieving reliable outcomes in the engineering design process. They are particularly
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While many design methods are developed, tested and reported in the literature, their utilization in industry practice remains low. Design methods are receiving substantial scholarly focus and are considered central to efficiently achieving reliable outcomes in the engineering design process. They are particularly vital as industrial companies increasingly transition to integrated offerings of products and services with a lifecycle perspective, leading to additional uncertainty and complexity. Thus, the presented research aims to support method selection and development, focusing on resource-efficient offerings. This is achieved through an in-depth, practice-centric, empirical study of users’ requirements of design methods and the corresponding characteristics of design methods aimed at meeting these requirements in resource-efficient offerings. Highly relevant insight supporting a broad set of stakeholders is reported. Firstly, the user requirements and method characteristics reported support practitioners seeking to identify a design method fitting their needs. Secondly, academics and practitioners aiming to enhance the usefulness and impact of a design method may benefit from considering these requirements and characteristics during method development. Lastly, the systematic approach taken in this research can be applied by both method developers and potential users to identify additional requirements and corresponding characteristics specific to their conditions. Two use cases for the results attained are reported, focusing on applying the research results for method selection and deriving overall guidelines for developing design methods directed toward resource-efficient offerings.
Full article
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Open AccessArticle
Quadcopter Unmanned Aerial Vehicle Structural Design Using an Integrated Approach of Topology Optimization and Additive Manufacturing
by
Luttfi A. Al-Haddad, Alaa Abdulhady Jaber, Wojciech Giernacki, Zeashan Hameed Khan, Khalid Mohsin Ali, Mauwafak Ali Tawafik and Amjad J. Humaidi
Designs 2024, 8(3), 58; https://doi.org/10.3390/designs8030058 - 14 Jun 2024
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The performance of quadcopter frames, particularly in terms of weight and crash resistance, is significantly influenced by their structural design and manufacturing process. In this work, a methodology is proposed that integrates advanced principles of topology optimization (TO) and additive manufacturing (AM) techniques
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The performance of quadcopter frames, particularly in terms of weight and crash resistance, is significantly influenced by their structural design and manufacturing process. In this work, a methodology is proposed that integrates advanced principles of topology optimization (TO) and additive manufacturing (AM) techniques to optimize the frame structure for improved performance. First, an analysis is conducted to evaluate existing quadcopter frame configurations, identifying areas for improvement. Experimental evaluations of thrust and moment of motors are performed to assess the performance of the enhanced quadcopter frame, with a focus on advancing the design through computer-aided simulations of static structural analysis and impact tests. The TO technique is then employed to determine the optimal distribution of material within the frame, governed by constraints such as weight reduction and mechanical strength. The results demonstrate that the overall performance of a quadcopter frame is significantly improved by the proposed methodology, showcasing advancements in stability, weight reduction, and crashworthiness. The resulting optimized frame design is subsequently manufactured using AM methods, which offer advantages such as design flexibility and the ability to produce complex geometries. The findings of this study contribute to the field of quadcopter design and optimization by highlighting the synergies between TO and AM techniques. An avenue is offered for the development of lightweight and robust quadcopter frames, as the capabilities and performance of quadcopter systems are advanced. The insights gained from this research open up opportunities for further advancements in the design and manufacturing of UAVs.
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Open AccessArticle
Biomechanics of a Novel 3D Mandibular Osteotomy Design
by
Carlos Aurelio Andreucci, Elza M. M. Fonseca and Renato N. Jorge
Designs 2024, 8(3), 57; https://doi.org/10.3390/designs8030057 - 13 Jun 2024
Cited by 1
Abstract
Elective mandibular surgical osteotomies are commonly used to correct craniofacial discrepancies. Since the modifications proposed by Obwegeser, Dal Pont, and Hunsuck, no effective variations have been proposed to improve the biomechanical results of these mandibular osteotomies. With technological developments and the use of
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Elective mandibular surgical osteotomies are commonly used to correct craniofacial discrepancies. Since the modifications proposed by Obwegeser, Dal Pont, and Hunsuck, no effective variations have been proposed to improve the biomechanical results of these mandibular osteotomies. With technological developments and the use of three-dimensional images from CT scans of patients, much has been done to plan and predict outcomes with greater precision and control. To date, 3D imaging and additive manufacturing technologies have not been used to their full potential to create innovative mandibular osteotomies. The use of 3D digital images obtained from CT scans as DICOM files, which were then converted to STL files, proved to be an efficient method of developing an innovative mandibular ramus beveled osteotomy technique. The new mandibular osteotomy is designed to reduce the likelihood of vasculo-nervous damage to the mandible, reduce the time and ease of surgery, and reduce post-operative complications. The proposed osteotomy does not affect traditional osteotomies. Anatomical structures such as the inferior alveolar nerve and intraoral surgical access were preserved and maintained, respectively. The results obtained from the digital images were validated on an additively manufactured 3D synthetic bone model.
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(This article belongs to the Collection Editorial Board Members’ Collection Series: Biomaterials Design)
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Open AccessArticle
Dimensional Accuracy in 4D-Printed PLA Objects with Holes: Experimental and Numerical Investigations
by
Alexandru-Antonio Ene, Tudor George Alexandru and Diana Popescu
Designs 2024, 8(3), 56; https://doi.org/10.3390/designs8030056 - 6 Jun 2024
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This study investigates the impact of material and process parameters—specifically, filament color, infill density, and pattern—on the dimensional accuracy of 4D-printed polylactic acid (PLA) objects featuring holes of varying diameters (6, 8, and 10 mm) that undergo a heat-induced recovery process. The objective
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This study investigates the impact of material and process parameters—specifically, filament color, infill density, and pattern—on the dimensional accuracy of 4D-printed polylactic acid (PLA) objects featuring holes of varying diameters (6, 8, and 10 mm) that undergo a heat-induced recovery process. The objective was to understand how these factors affect shape retention and the dimensional accuracy of holes through a comparative analysis of the diameters before and after recovery. Increased variability in the hole diameters was noted after recovery, regardless of the values of the independent variables. The objects did not fully return to their original planar shape, and the holes did not completely return to their circular form, resulting in smaller diameters for each sample. No significant differences in the hole diameters could be determined. Additionally, there was no consistent trend in identifying the most influential parameter affecting the accuracy of the recovered holes. However, it was observed that higher infill densities improved shape retention. A quasi-static finite elements analysis model was developed to capture the mechanical behavior of the 4D-printed parts. This model incorporated temperature-dependent material characteristics to predict the strain occurring near the holes. Nodal displacements were defined according to the deformed shape. A correlation was established between the observed strains and the post-recovery dimensional accuracy of the specimens. The importance of this work was demonstrated through a case study involving a two-sieve filtering device for small objects.
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Open AccessArticle
Experimental Behaviour of Tensioner for Rigid Hangers of Arch Bridges
by
Michele Fabio Granata, Benedetta Fontana, Marco Rosone and Giovanni Culotta
Designs 2024, 8(3), 55; https://doi.org/10.3390/designs8030055 - 5 Jun 2024
Abstract
In steel tied arch bridges where the hangers are made of rigid bars, the replacement of damaged hangers is rather complex. In fact, while generally the cable hangers are already prepared with anchors at the ends and their replacement traces the initial stages
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In steel tied arch bridges where the hangers are made of rigid bars, the replacement of damaged hangers is rather complex. In fact, while generally the cable hangers are already prepared with anchors at the ends and their replacement traces the initial stages of construction with their prestressing, on the contrary, the rigid bars are welded to the arch and the deck, so their replacement must include the design of a new suspension system that allows the insertion of a pretension where this had never been considered. To check the reliability of this new system, a prototype of tensioner was studied for the case of a steel arch bridge in which the high level of corrosion made it necessary to replace all the original hangers with new ones. This entailed the need to test the tensioner performance with the aim of ensuring the axial force transmission between the two hanger segments without slippage in the threads, as well as to test the correct tension setting before construction and putting into service the hangers to be replaced. For this reason, a predictive experimental campaign was carried out on a prototype by means of tests for the mechanical characterization of the materials used, tensile tests of the system, and tensioning tests under load, measuring the displacements and strains of the system elements. The results of the tests, with slippage in the threads limited to the 2% of total elongation, and the turnaround-stressing curves were useful for the definition of the pieces to be assembled during on-site work and for addressing the operating procedures of the tensioning phases on-site during hanger replacement. Validation with the on-site monitoring of stressing operation was conducted at the end; the monitoring of tension through dynamic tests confirmed the agreement of on-site results with the predictive loading tests of the experimental campaign on the tensioner prototype.
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(This article belongs to the Topic Resilient Civil Infrastructure)
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