Search Results (20)

Successful dental implant therapy relies on accurate planning and placement, e.g., through static, computer-aided implant surgery using CAD/CAM-fabricated surgical guides. This study examined production methods’ influence on surgical guide sleeve housing geometry. A model with two edentulous spaces was digitized using intraoral scanning and CBCT, and two virtually positioned implants were planned. Ten guides per group were produced using milling (MCX5), DLP printing (ASIGA and SHERA), and SLA printing (FORM), printing with 50 µm and 100 µm layers each. Each guide (n = 70) was then digitized using an industrial scanner before and after sterilization. Superimposition of the actual guide data with the reference data allowed for evaluation of deviations at the drill sleeve housing along the x-, y-, z-, and dxyz-axes. Descriptive and statistical evaluation was performed (significance level: p ≤ 0.0125). Significant differences existed among the production methods: Milling and SLA showed higher deviations than the DLP group (p < 0.001). Milled guides post-sterilization showed the highest deviations (0.352 ± 0.08 mm), while one DLP printer at 50 μm layer thickness showed lowest deviations (0.091 ± 0.04 mm). The layer thickness was insignificant, whereas sterilization increased deviation (p < 0.001). DLP produced the most precise implant surgical guides. All 3D printers were suitable for fabricating clinically acceptable surgical guides. Full article

Background/Objectives: The introduction of composite attachments has greatly improved orthodontic aligner therapy, through better force delivery, more predictable movements, and enhanced retention. This in vitro study aims to present and investigate an innovative digital protocol for aligner attachment fabrication incorporating the latest 3D technology used in dentistry. Methods: A virtual attachment measuring 2.5 × 2 × 2 mm was designed using computer-aided design (CAD) software (Meshmixer, Autodesk Inc., San Francisco, CA, USA) and exported as an individual STL file. The attachments were fabricated using a digital light processing (DLP) 3D printer (model: Elegoo 4 DLP, Shenzhen, China) and a dental-grade biocompatible resin. A custom 3D-printed placement guide was used to ensure precise positioning of the attachments on the printed maxillary dental models. A flowable resin was applied to secure the attachments in place. Following attachment placement, the models were scanned using a laboratory desktop scanner (Optical 3D Smart Big, Open Technologies, Milano, Italy) and three intraoral scanners: iTero Element (Align Technology, Tempe, AZ, USA), Aoral 2, and Aoral 3 (Shining 3D, Hangzhou, China). Results: Upon comparison, the scans revealed that the iTero Element exhibited the highest precision, particularly in the attachment, with an RMSE of 0.022 mm and 95.04% of measurements falling within a ±100 µm tolerance. The Aoral 2 scanner showed greater variability, with the highest RMSE (0.041 mm) in the incisor area and wider deviation margins. Despite this, all scanners produced results within clinically acceptable limits. Conclusions: In the future, custom attachments made by 3D printing could be a valid alternative to the traditional composite attachments when it comes to improving aligner attachment production. While these preliminary findings support the potential applicability of such workflows, further in vivo research is necessary to confirm clinical usability. Full article

Robot acceptance is rapidly increasing in many different industrial applications. The advancement of production systems and machines requires addressing the productivity complexity and flexibility of current manufacturing processes in quasi-real time. Nowadays, robot placement is still achieved via industrial practices based on the expertise of the workers and technicians, with the adoption of offline expensive software that demands time-consuming simulations, detailed time-and-motion mapping activities, and high competencies. Current challenges have been addressed mainly via path planning or robot-to-workpiece location optimization. Numerous solutions, from analytical to physical-based and data-driven formulation, have been discussed in the literature to solve these challenges. In this context, the machine learning approach has proven its superior performance. Nevertheless, the industrial environment is complex to model, generating extra training effort and making the learning procedure, in some cases, inefficient. The industrial problems concern workstation productivity; path-constrained minimal-time motions, considering the actuator’s torque limits; followed by robot vibration and the reduction in its accuracy and lifetime. This paper presents a procedure to find the robot base location for a prescribed task within the robot’s workspace, complying with multiple criteria. The proposed hybrid procedure includes analytical, physical-based, and data-driven modeling to solve the optimization problem. The contribution of the algorithm, for a given user-defined task, is the search for the best robot base location that enables the target points, maximizing the manipulability, avoiding singularities, and minimizing energy consumption. Firstly, the established method was verified using an anthropomorphic robot that considers different levels of a priori kinematics and system dynamics knowledge. The feasibility of the proposed method was evaluated through various simulations for small- and medium-sized robots. Then, a commercial offline program was compared, considering three scenarios and fourteen robots demonstrating an energy reduction in the 7.6–13.2% range. Moreover, the unknown joint dependency in real robot applications was investigated. From 11 robot positions for each active joint, a direct kinematic was appraised with an automatic DH scheme that generates the 3D workspace with an RMSE lower than 65.0 µm. Then, the inverse kinematic was computed using an ANN technique tuned with a genetic algorithm showing an RMSE in an S-shape task close to 702.0 µm. Finally, three experimental campaigns were performed with a set of tasks, repetitions, end-effector velocity, and payloads. The energy consumption reduction was observed in the 12.7–22.9% range. Consequently, the proposed procedure supports the reduction in workstation setup time and energy saving during industrial operations. Full article

In recent years, Poland has implemented substantial changes to its energy mix, resulting in an increased proportion of energy production from photovoltaics (PV). However, the photovoltaic energy market’s development is determined by several factors, and still requires further analysis. Therefore, the study’s main objective was to comprehensively understand the PV phenomenon and its development in Poland. Furthermore, a PESTEL analysis was undertaken to assess the macroeconomic context of the photovoltaic industry in Poland. A systematic literature review methodology was employed to achieve this. The study’s principal findings identified a number of pivotal opportunities and barriers to PV development. The environmental benefits of CO₂ reduction and the economic advantages, including cost savings and subsidies, were identified as significant opportunities, as were social acceptance and enhanced energy security. However, obstacles to progress include outdated grid infrastructure, high investment costs, environmental concerns during the PV lifecycle, and political uncertainties. Technical challenges like grid stability and high battery costs also impede growth. Potential strategies for improvement involve better public awareness campaigns, enhanced self-consumption through storage systems, and optimised system placement. Addressing these factors could transform current neutral aspects into either opportunities or threats for PV deployment. Full article

This study investigates consumer preference and acceptance of three meat alternatives—plant-based, lab-grown, and insect-based—as sustainable choices to meet the demands of a growing population and evolving food systems. Insights were gathered from European consumers regarding their perceptions and consumption patterns using a mixed-methods approach. The approach employed a questionnaire followed by focus group discussions conducted in Slovenia and the UK to understand the motivations and barriers behind their responses. The UK and Slovenia were chosen as they provided the highest response rates to the questionnaire and they have differing legislation. The results show that plant-based alternatives are the most familiar and accepted option, while lab-grown meat and insect-based products are less familiar and have lower acceptance rates. Moreover, they show that although sustainability factors are important to consumers, they are not their only concern; health and nutrition are the primary motivators for choosing meat alternatives. These are followed closely by sensory appeal, pricing, and a preference for natural, minimally processed options. Based on insights from the focus groups, strategies to overcome the barriers to the acceptance of meat alternatives should include targeted product categorisation and placement, educational campaigns, effective use of media, and greater transparency in product information. Full article

Along with declaratives and interrogatives, imperatives are one of the three major clause types of human language. In Spanish, imperative verb forms present poor morphology, yet complex syntax. The present study examines the acquisition of (morpho)syntactic properties of imperatives in Spanish among English-speaking heritage speakers of Spanish. With the use of production and acceptability judgment tasks, this study investigates the acquisition of verb morphology and clitic placement in canonical and negative imperatives. The results indicate that the acquisition of Spanish imperatives among heritage speakers is shaped by the heritage speakers’ productive vocabulary knowledge, lexical frequency and syntactic complexity. Indeed, most of the variability in their knowledge was found in their production of negative imperatives: heritage speakers show a rather stable receptive grammatical knowledge while their production shows signs of variability modulated by the heritage speakers’ productive vocabulary knowledge and by the lexical frequency of the verb featured in the test items. Full article

Assessing concrete quality as construction goes on provides early warnings of potential flaws and leads to timely corrections in mix proportioning and placement techniques. Compressive strength and maturity modeling are among the most common parameters used by the concrete industry. Past studies indicated that non-destructive methods, NDTs, relate well to maturity and concrete strength predictions. In this study, the hydration temperature–time history of concrete was explored in defining “master curves” for concrete maturity for the first time. Well-accepted NDTs, such as ultrasonic pulse velocity and resonant frequency, were used in this effort. The study findings indicated that the novel approach of “master curves” for the maturity of concrete can be defined and follow a generalized logarithmic form. The best fit models relating NDT response and the maturity temperature–time product provided a high coefficient of determination (i.e., in almost all cases above 0.9 and p < 0.05), thus resulting in a very good fit. The shift factors for each mixture’s maturity function in relation to the master curve were related to concrete properties. The shifted maturity functions from the concrete mixtures included in the study had a perfect transition to the master curve (i.e., all the shifted data overlap the master curve trend line with an R² = 1). The NDTs’ ability to capture the hydration temperature-time history was assessed with impeded sensors into the concrete mixtures. This approach has provided strength prediction models with a high accuracy (i.e., good agreement between observed and predicted strength values with R² = 0.93). The proposed NDT-based maturity modeling through “master curve” development provides significant benefits in relation to traditional maturity modeling since it offers the opportunity to: (i) predict strength without having to repeat maturity testing each time a producer adjusts mixture proportioning to fine tune mix design; (ii) save testing time and cost due to reduced maturity evaluation from the use of master curves; and (iii) be able to quickly predict without further testing what the strength gain will be due to variations in mixture proportioning. The ability to monitor concrete maturity, and thus strength, with NDTs in reinforced concrete is of particular interest since using cores is problematic due to the presence of reinforcement. Full article

This paper explores the effect of product placement strategies on customer behavior in the Chinese context and the results will help companies in China select appropriate marketing strategies to achieve sustainable development. Following the Foote, Cone and Belding (FCB) grid model, we construct a product difference model in which products are classified into four types, namely High Involvement/Thinking, High Involvement/High Feeling, Low Involvement/Thinking, and Low Involvement/High Feeling. Further, we conduct a questionnaire survey to analyze the effect of product placement strategies on various behaviors, including awareness, recognition, attitude and purchase intention. The results of repeated measures of General Linger model suggest that Chinese customers accept product placement strategies. Furthermore, among the four product types, the positive effect of product placement strategies on customer behavior is more pronounced in the Low Involvement/High Feeling product type. However, the purchase intention of Chinese customers is stable and hard to change. The results also help the company to avoid misleading advertising and to design sustainable marketing strategies by applying more effective tools in terms of specific product types. As a result, the company will reduce financial expenditure to achieve sustainable development. Full article

This design activity is an innovative method of rapid assembly system for folding chairs. The research methods used in this study included literature analysis, TRIZ the method, human factors engineering (HFE), universal design, and IPA. First, the design of the folding chair and the layout of the literature related to the chair are analyzed. The contradiction matrix was used in the TRIZ method to find the principle of invention and analyze it, to provide a reference for the innovative design of folding chairs, and then use the relevant literature on materials to help design and select materials quickly. Next, the chair is assembled and unfolded and universal design is applied to design it into an acceptable product, causing it to be more popular. The human–machine interaction with HFE makes the design of rapid assembly and the design of folding chairs faster and safer. Finally, the IPA method is used to understand the subjective feelings of customers on the products of this research and the satisfaction and importance are used as the basis for evaluation; a two-dimensional matrix graph is drawn. After drawing a simulation using drawing software, it is compared with the traditional folding chair and the research results are as follows: (1) Quick unfolding function: use the pull ring upwards and it naturally unfolds downwards by gravity. (2) Quick folding and storage function: use the foot pedal, single-foot operation, and the folding chair can be quickly stored. (3) Rapid transportation and unfolding function: The chair back can be connected with other chair backs and has the functions of quick unfolding and quick storage, so as to realize the quick placement of the folding chair. This design activity realizes the preliminary design concept and design simulation of the product design through a systematic and innovative method. Through this design activity, we can understand the problems existing in product improvement before product development, so as to conduct market research and production cost assessment in the actual mass production later, and further reduce the cost of product design improvement. Full article

Vacuum-insulated glazing (VIG) has excellent sound and heat insulation and anti-fogging properties, having been a typical structure–function-integrated glass deep processing product. However, overlapping, vacancy and excessive spacing distance of the supporting pillars will increase the concentrated stress for the glass substrate, raising the potential risk of failure. Therefore, this study, aiming to address the high cost of sample preparation and the multiple factors affecting stress distribution, developed a multi-objective design for supporting stress. In this paper, a multi-objective optimization model was designed based on comprehensive mechanical analysis under square-distributed supporting. The critical supporting pillars radius as well as the critical spacing distance were solved and met the strength requirement. Case simulation demonstrated that a 0.2 mm or more radius and a 63 mm or less spacing distance for the supporting pillars were acceptable placement methods which conformed to the design requirements. This research will act as a theoretical reference for future studies, promoting the in-depth development of VIG and exploration of high-strength safety products. Full article

Unhealthy food and beverage availability and sponsorship undermine healthy food practices in sport and recreation. We conducted a focused ethnography with reflexive photo-interviewing to examine parents’ awareness, reactions, and experiences of food and beverage marketing in and around their children’s physical activity in public sport and recreation facilities. Eleven parents took photos of what they thought their facility was ‘saying about food and eating’. Photos guided semi-structured interviews on the ‘4Ps’ of marketing (product, pricing, placement, promotion). Thematic analysis was conducted by holistic coding followed by in vivo, versus, and value coding. Photo-taking increased parents’ awareness of food marketing in facilities. Reactions to food and beverage marketing were positive or negative depending on parents’ perspectives of healthy food availability (choice), marketers’ motives, and mixed messages within the facility. Parents experienced their children requesting ‘junk’ food at the facility leading to parents actively attempting to reduce the frequency of these requests. Healthy eating promotion in sport and recreation facilities was misaligned with the foods and beverages available which contributed to parents’ distrust of social marketing initiatives. Critically evaluating the alignment of commercial and social marketing in recreation and sport may help inform effective healthy eating interventions that are accepted and supported by parents. Full article

Currently, a number of disadvantages hampers the use of recycled concrete aggregates (RCA). The current review proves that concretes made with complete replacement of natural aggregate with RCA allow the production of high-quality concrete. One of the possibilities for improving concrete properties with RCA is the use of extended curing and pozzolanic materials with varying cement ratios. The potential use of RCA concretes is in the production of high-value materials that increase environmental and financial benefits. RCA have strong potential in the development of a new generation of concrete and stimulate economic activity in many countries in addition to optimizing natural resources. Economic benefits include minimal travel costs; cheaper sources of concrete than newly mined aggregates; reduction of the landfill area required for the placement of concrete waste; the use of RCA minimizes the need for gravel extraction, etc. The proposed strategy could be to sequentially separate demolition waste such as roof finishes, waterproof materials, interior and exterior materials, etc. Closing life cycles is the main approach used for efficient structures for the recycling and reuse of construction and demolition waste in the production and recovery of materials, especially when recycling and reusing materials. In the life cycle, the recycling of recovered materials allows them to be used for new construction purposes, avoiding the use of natural concrete aggregates. Government, design institutes, construction departments and project managers should be involved in the creation and use of RCA. In demolition and construction, the main players are the project owners. Their obligations, expectations and responsibilities must be properly aligned. For the past 20 years, recycled concrete aggregate from demolition and construction waste has been considered as an alternative to pure concrete in structural concrete to minimize the environmental impact of construction waste and demolition waste and the conversion of natural aggregate resources. It is now recognized that the use of RCA for the generations of concrete is a promising and very attractive technology for reducing the environmental impact of the construction sector and conserving natural resources. In the market, the selling price is not an obstacle for market applications of RCA, as there are scenarios in which their cost is lower than the cost of products made from conventional building materials. This is more of an acceptance factor in the market for recycled concrete aggregates. In this sector, the lack of identification, accreditation and uniform quality certification systems and their narrow application cause some marketing problems. With proper RCA preparation, concrete with standard physical and mechanical properties and performance characteristics can be obtained. Full article

An important factor in consumers’ acceptability, beyond visual appearance and taste, is food texture. The elderly and people with dysphagia are more likely to present malnourishment due to visually and texturally unappealing food. Three-dimensional Printing is an additive manufacturing technology that can aid the food industry in developing novel and more complex food products and has the potential to produce tailored foods for specific needs. As a technology that builds food products layer by layer, 3D Printing can present a new methodology to design realistic food textures by the precise placement of texturing elements in the food, printing of multi-material products, and design of complex internal structures. This paper intends to review the existing work on 3D food printing and discuss the recent developments concerning food texture design. Advantages and limitations of 3D Printing in the food industry, the material-based printability and model-based texture, and the future trends in 3D Printing, including numerical simulations, incorporation of cooking technology to the printing, and 4D modifications are discussed. Key challenges for the mainstream adoption of 3D Printing are also elaborated on. Full article

We pose that instead of problematizing negative attitudes of local stakeholders, such as citizens and NGOs, wind energy implementers should be more focused on scrutinizing the acceptability of their projects. The emphasis in this study is on the potential for representation of local stakeholders’ values in the project design, including amongst others business model and placement. Informed by value sensitive design literature, we analyzed two contrasting, locally-owned wind projects in the Dutch province of Groningen: the implementation of mini-turbines in a national landscape and a large-scale multi MW wind project in an industrialized area close to a World Heritage nature reserve. The study analyses how the respective farmer-developers and other local stakeholders attempted to resolve or ameliorate inter- and intra-value conflicts regarding livability, economy, landscape, and nature. The value conflicts turned out to be fruitful to identifying key issues and creating more widely shared value conceptualizations and design priorities. Hence, from this study it can be concluded that value conflict can be productive if carefully unpacked and managed. Uneven power distribution among stakeholders in the planning process, overcoming incommensurability of perspectives, and creating intersubjectivity remain challenges. Full article

Nowadays, product placements are commonly presented on mobile social media but related studies are rare. The main purpose of the study is to investigate the effects of content likeability, content credibility, and social media engagement on users’ acceptance of product placement in mobile social networks. The results of the online survey indicate that content likeability is an antecedent of social media engagement and content credibility; social media engagement has an influence on content credibility; and content likeability, content credibility, and social media engagement both directly affect user acceptance of product placement in mobile social networks. Furthermore, social media engagement has an interaction effect with content likeability on the content credibility of mobile social networks. The results of the multi-group analysis indicate that young adults show differences with middle-aged adults in the direct effect of content likeability on social media engagement and in the interaction effect of content credibility and social media engagement on the acceptance of product placement in mobile social networks. The implications for practitioners are discussed on the basis of the empirical findings. Full article