Antonella Sola, Wei Juene Chong, Dejana Pejak Simunec, Yuncang Li, Adrian Trinchi, Ilias (Louis) Kyratzis, and Cuie Wen
Polymer Testing, Vol 117, Iss , Pp 107859- (2023)
Tensile properties, International standard, Size effect, Additive manufacturing, Fused filament fabrication, Fused deposition modeling, Polymers and polymer manufacture, and TP1080-1185
Additive manufacturing (AM, also commonly termed 3D printing) is progressing from being a rapid prototyping tool to serving as pillar of the Industry 4.0 revolution. Thanks to their low density and ease of printing, polymers are receiving increasing interest for the fabrication of structural and lightweight parts. Nonetheless, the lack of appropriate standards, specifically conceived to consistently verify the tensile properties of polymer parts and benchmark them against conventional products, is a major obstacle to the wider uptake of polymer AM in industry. After reviewing the standardisation needs in AM with a focus on mechanical testing, the paper closely examines the hurdles that are encountered when existing standards are applied to measure the tensile properties of polymer parts fabricated by fused filament fabrication (FFF, aka fused deposition modeling, FDM), which is presently the most popular material extrusion AM technique. Existing standards are unable to account for the numerous printing parameters that govern the mechanical response of FFF parts. Moreover, the literature suggests that the raster- and layer-induced anisotropic behaviour and the complicated interplay between structural features at different length scales (micro/meso/macro-structure) undermine pre-existing concepts regarding the specimen geometry and classical theories regarding the size effect, and ultimately jeopardise the transferability of conventional tensile test standards to FFF parts. Finally, the statistical analysis of the tensile properties of poly(lactic acid) (PLA) FFF specimens printed according to different standards (ASTM D638 type I and ASTM D3039) and in different sizes provides experimental evidence to confirm the literature-based argumentation. Ultimately, the literature survey, supported by the experimental results, demonstrates that, until dedicated standards become available, existing standards for tensile testing should be applied to FFF with prudence. Whilst not specified in conventional standards, set-up and printing parameters should be fully reported to ensure the repeatability of the results, rectangular geometries should be preferred to dumbbell-like ones in order to avoid premature failure at the fillets, and the size of the specimens should not be changed arbitrarily.
Risna Sari, Anggi Muhammad Rifa’i, Muhammad Salimy Ahsan, Mohammad Rezza Pahlevi, and M. Ilham Arief
International Journal of Research and Applied Technology, Vol 2, Iss 2, Pp 154-171 (2022)
software engineering, spiral model, slr, Information technology, and T58.5-58.64
The spiral model is one of the methods used to perform software engineering development and can also be used for development in other fields. This spiral model is the result of a modification from the combination of the waterfall model and prototyping model so that it has many advantages including in each result an evaluation will be carried out, carried out sequentially or systematically, and is more focused in carrying out risk analysis from each stage. Has a function in development to make changes, additions and developments by determining accuracy and speed based on needs. In its implementation the spiral model has been carried out in various fields, but the results of the implementation are not yet known in what scope and how many implementations each year. This study aims to identify the results of the implementation of the spiral model development with data obtained from related papers in the 2012-2022 range. The method used in this study is the Systematic Literature Review (SLR) with the aim of identifying, reviewing, evaluating, and concluding all research on each relevant paper. The results showed that the spiral model development was mostly implemented in software development with a total of 19 papers and in the education sector as many as 17 papers, while the peak of the spiral model development was mostly implemented in 2016 and then increased again in 2021
Measurement: Sensors, Vol 24, Iss , Pp 100557- (2022)
Computational technique, Prototype, Software development, Artificial intelligent, Electric apparatus and materials. Electric circuits. Electric networks, and TK452-454.4
The software development process is witnessing an increasing trend among many educational and non-educational institutions and companies. Where many enterprise managers are attracted to the benefits of software development to improve the performance of the existing programs and increase their efficiency.The present study aims to develop an employee information management system. To obtain this objective, the initial Prototype was adopted in the development process. A new analysis and design that is commensurate with the opinions of senior managers is conducted in the present study with the participation of users to facilitate the process of software design and to analyze the current system for development purposes using prototypes in the UML environment.On the other hand, Through this study, we reached results There are many benefits through the development of the existing programs such as reducing costs and time that systems designers spend in the stages of system creation through implementation, training, maintenance, and system testing.
Revista de Economie Mondială, Vol 13, Iss 2, Pp 23-47 (2022)
additive manufacturing, 3d printing, china, Economics as a science, and HB71-74
Additive manufacturing - or three-dimensional (3D) printing - refers to a group of technologies characterised by an accelerating maturation trend, which allow the creation of three-dimensional objects based on digital models, by sequentially applying and integrating layers of various traditional and innovative materials, from metals, polymers and ceramics, to graphene and other nanomaterials and composites. The technologies have applications in a variety of industries, from consumer goods production, automotive and aircraft parts, architecture and construction, to medical services and devices, or research and defence. Globally, the additive manufacturing market, which includes equipment, materials and 3D printing as a service, as well as their applications for prototyping and rapid manufacturing, has been valued at USD 15.4billion in 2020, with existing projections reflecting a four-fold increase to USD 61.1 billion in 2027. By the same date, China – the current 'factory of the world' – is projected to have a significant but less than one-quarter share of the global market – USD14.5 billion – against the backdrop of existing gaps difficult to narrow down.
Digital fashion, digital twin, digital transformation, culture, fashion design, business model, Social sciences (General), and H1-99
This article provides a comprehensive overview of the digital transformation of the fashion industry and describes the opportunities and influences on supply chains, business models, and sustainability-oriented innovations that it offers. Desk research was performed to review emerging cases of companies that engage actively in using 3-dimensional virtual and digital (3DVD) technologies, such as 3D modeling, virtual and augmented reality (VR and AR), 2- and 3-dimensional (2D/3D) scanning, and digital twinning (DT). The analysis shows how the adoption of digital technologies provides opportunities to dematerialize the traditional fashion supply-chain model of garment production and distribution and maps the innovative shifts occurring in the fashion industry’s processes, products, and services. The adoption of 3DVD technologies by fashion companies unleashes new opportunities with respect to innovation in products/services and optimization of operational processes to streamline activities, shorten the lead time for designing, prototyping, manufacturing, marketing and retailing, and reorganizing the working phases. These capabilities also drive multicentred business-model innovations and thus affect value creation and delivery and capture changes. In addition, the analysis shows that digital transformation affects the four dimensions of sustainability that are interconnected intrinsically across supply-chain processes. Cultural sustainability is paramount, as fashion is a complex cultural system that is able to create products/services that influence the environment, economy, and society. In particular, 3DVD technologies promote cultural transformation of design processes to achieve a remix of skills and open knowledge, a behavioral shift from the consumer perspective in terms of diversity and self-expression, and a change in the organizational culture of companies that drive the digital transformation.
Nature consists of numerous solutions to overcome challenges in designing artificial systems. Various actuation mechanisms have been implemented in microrobots to mimic the motion of microorganisms. Such bio-inspired designs have contributed immensely to microscale developments. Among the actuation mechanisms, magnetic actuation is widely used in bio-inspired microrobotic systems and related propulsion mechanisms used by microrobots to navigate inside a magnetic field and are presented in this review. In addition, the considered robots are in microscale, and they can swim inside a fluidic environment with a low Reynolds number. In relation to microrobotics, mimicry of bacteria flagella, sperm flagella, cilia, and fish are significant. Due to the fact that these biological matters consist of different propulsion mechanisms, the effect of various parameters was investigated in the last decade and the review presents a summary that enhances understanding of the working principle of propulsion mechanisms. In addition, the effect of different parameters on the various speeds of the existing microrobots was analyzed to identify their trends. So, the swimming speeds of the microrobots show an upward trend with increasing body length, frequency, magnetic flux density, and helix angle. Microfabrication techniques play a significant role in the microscale because the device designs are highly dependent on the availability of the techniques. The presented microrobots were manufactured by 3D/4D photolithography and rapid prototyping techniques. Proper materials enable effective fabrication of microrobots using the mentioned techniques. Therefore, magnetically active material types, matrix materials, biocompatible and biodegradable materials are presented in this study. Utilizing biocompatible and biodegradable materials avoids adverse effects to the organs that could occur otherwise. In addition, magnetic field generation is significant for the propulsion of such microrobots. We conclude the review with an overview of the biomimicry of microrobots and magnetically actuated robot propulsion.
Wonkyo Kim, Jungho Kim, Jonghyo Won, Dongho Yu, and Ick-Jae Yoon
Applied Sciences, Vol 12, Iss 11811, p 11811 (2022)
dielectric lens antenna, 3D printing technology, radiation performance improvement, effective dielectric constant, ring resonator, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, and QD1-999
In this work, we present a method for designing a dielectric lens with a reduced height that is easily printed with one-take 3D printing. For the first time, we prove that the configuration of a printout made of resin material can be modified for effective permittivity variation and apply the technique to a lens antenna design. The lens is printed with SLA printing and mounted on top of a conventional patch antenna, resulting in a 6.87 dB directivity improvement. The height of the proposed lens is reduced by about 15% compared to the reference lens design. The final proposed lens antenna operates at 5.8 GHz, with a height and diameter of 1.35 λ and 1.35 λ, respectively. A prototype was built, and all of the computed expectations from the full-wave electromagnetic simulations in this work were verified experimentally.
Abstract Background Many clinical studies have reported the high success rate of the All-on-4 concept. In the present study, we aimed to compare the stress distribution with different tilted distal implants and cantilever lengths in an All-on-4 system using the two-dimensional photoelastic method and to establish the All-on-4 implant photoelastic model by computer-aided design (CAD) and rapid prototyping (RP). Methods The data of the human edentulous mandible were acquired by computed tomography (CT). Three human edentulous mandible All-on-4 implant models with different distally inclined implant holes were fabricated using Mimic, Geomagic Studio software, and a light solidifying fast shaping machine. Then the final photoelastic models were established through the traditional method. Each of the three models had four NobelSpeedy Replace implants between the interforaminal regions. The two posterior implants were placed 0, 15, and 45 degrees distally before the mental foramen. The four implants were splinted by wrought cobalt-chromium alloy frameworks. Each of the three photoelastic models was submitted to a 150 N vertical load at five points on the framework: the central fossa of the mandibular first molar, and 0 mm, 5 mm, 10 mm, and 15 mm of the cantilever length. The stress produced in the models was photographed with a digital camera, and the highest value of the stressed fringe pattern was recorded. Results The All-on-4 implant photoelastic model established by CAD and RP was highly controllable and easy to modify. The position and inclination of implants were accurate, and the frameworks could be passively emplaced. The stress values were higher around a single tilted implant compared with the distal implant in All-on-4 with the same inclination. The 0-degree distal implant and 45-degree distal implant demonstrated the highest and lowest stress when loading at the central fossa of the mandibular first molar, respectively. With the same inclination of distal implant, the peri-implant bone stress increased as the length of cantilever increased. Conclusion The method of establishing the All-on-4 implant photoelastic model by CAD and RP was highly controllable, convenient, fast, and accurate. The tilted implants splinted in the fully fixed prosthesis with reduced cantilever lengths did not increase the stress level compared with the vertical distal implants.And this illustrated that the influence of cantilever on stress distribution was greater than the influence of implant inlination.
Gang Xu, Geeth Silva, Tim Bourne, Graeme Hall, and Aaron Vogel
BMJ Open Quality, Vol 11, Iss 4 (2022)
Medicine (General) and R5-920
Introduction University Hospitals of Leicester (UHL) has co-developed and deployed a novel Electronic Prescribing and Medicines Administration (EPMA) application as part of the trust electronic patient record (EPR) programme that meets specific clinical demands and interoperability standards of the National Health Service (NHS) despite clinical pressures from the COVID-19 pandemic.Methods Following an initial limited pilot deployment, a big-bang whole site-based approach allowed transition of 1844 acute adult inpatients beds from an existing standalone EMPA to the new system. This project used a frontline driven and agile management strategy. Clinical risk was managed using a combination of standard risk logs, robust clinical prototyping and robust disaster recovery plans. Early engagement with clinical teams allowed for advanced product configuration before live deployment and reduced the need for sustained transition support for clinical staff.Results An iterative, well-governed approach, led by a combination of information technology (IT) and clinical staff with a responsive vendor, enabled a complex new EPMA system in a large acute NHS trust to be deployed with limited resources despite the ongoing COVID-19 pandemic.Discussion The development and deployment of EMPA and EPR systems across NHS trusts is a key enabler for better healthcare delivery. This case study shows it is possible to deploy a new clinical IT system at scale without interruption of clinical services and with a relatively modest deployment team. Sustainability of the project was also ensured through a clear clinically led governance structure to manage risk quickly and carry lessons learnt onto new developments.
In the following research work, an experiment of guided innovation is presented. The context is the Innovation for Change (I4C) program, in which a group of students, either PhDs or MBAs, are asked to solve a challenge provided by a stakeholder. The problem is “the future of work” in the context of a post pandemic scenario, with a focus on how to manage spaces remained empty due to remote working. The solution obtained is the consequence of a combination of brainstorming sessions, problem definition, benchmarking and interviewing stakeholders, experimental validation and prototyping. The outcome is a platform, B-Hub, which exploits empty locations to create a network of decentralised co-working spaces in which employees from every company can remotely work.
Christina Schreppel, Andreas Pfeiffer, Julian Ruggaber, and Jonathan Brembeck
Computers, Vol 11, Iss 165, p 165 (2022)
Kalman filter, vehicle state estimation, road friction estimation, C implementation, embedded systems, Electronic computers. Computer science, and QA75.5-76.95
Having knowledge about the states of a system is an important component in most control systems. However, an exact measurement of the states cannot always be provided because it is either not technically possible or only possible with a significant effort. Therefore, state estimation plays an important role in control applications. The well-known and widely used Kalman filter is often employed for this purpose. This paper describes the implementation of nonlinear Kalman filter algorithms, the extended and the unscented Kalman filter with square-rooting, in the programming language C, that are suitable for the use on embedded systems. The implementations deal with single or double precision data types depending on the application. The newly implemented filters are demonstrated in the context of semi-active vehicle damper control and the estimation of the tire–road friction coefficient as application examples, providing real-time capability. Their per-formances were evaluated in tests on an electronic control unit and a rapid-prototyping platform.
MAV, UAV, OAV, UAS, coleopter, convertible aircraft, Motor vehicles. Aeronautics. Astronautics, and TL1-4050
This paper opens with an historical overview of efforts to develop micro-, mini-, and organic aerial vehicles (MAVs and OAVs) in the 1990’s. Although conceived during WWII, coleopters would not see serial production for 60 years. The paper continues with programmatic aspects of hovering coleopter development of the 1990’s and describes the technical motivations behind in-flight conversion from hover-mode to missile-mode flight and the record-setting XQ-138 family of convertible coleopters. As the first commercially successful family of such aircraft, the XQ-138 was taken from initial concept through configuration design, detailed design, patenting, prototyping, proof-of-concept, production, flight testing, qualification, and eventually high rate production, all with private funding. The paper lists basic engineering drivers, covers fundamental sizing methods, presents weight fraction data, and describes flight test procedures, locations, conditions, and results. High-speed flight test data show the stock aircraft achieving speeds in excess of 164 mph (263 kph) with endurances in excess of an hour at that speed with a special dash-optimized version reaching 288 mph (463 kph) for a few minutes. Videos from flight testing and live-fire exercises are shown at Redstone Arsenal, Eglin Air Force Base, and Fort Benning test ranges under extreme conditions. The paper concludes with an assessment of civil and military variants for a variety of military missions and commercial uses.