Search Results (150)

In order to establish the influence of prolonged exposure to high temperatures on 14MoV6-3 steel, three different weld joints were designed. New-to-new material, new-to-used material, and used-to-used material joints were welded using two welding technologies—GTAW and a combination of GTAW + MMA. The weldments were tested by means of microstructure and tensile testing. The results showed that in all weldments, a fracture occurred in the base metal. Also, in the case of the new-to-used welded sample, the fracture always occurred in the used base metal. Since both materials have the same chemical composition, the difference in microstructure was related to long exposure to high temperatures. New steel has a considerably smaller grain size, while the used material underwent grain growth coupled with carbide coarsening, which decreased its strength. The yield strength (YS) of the new material was higher than the YS of the used material, which exhibited similar values in the used base metal and both weldments. It can be assumed that, since deformation starts in the area with the lowest yield point, the used material is the critical place in a given weldment. Therefore, the accurate extent of strength decrease cannot be evaluated based on the testing of new material, i.e., there is a need to reconsider the traditional qualifications of welding technology. Full article

This study examines the key obstacles that hinder the mass adoption of additive manufacturing (AM) processes for fabrication and processing of metal parts. To address these challenges, the necessity of integrating an intelligent decision support system (DSS) into the workflow of AM process engineers is demonstrated. The advantages of applying a two-level ontological approach to the creation of semantic information to develop an ontology-based DSS are pointed out. A key feature of this approach is that the ontological models are clearly separated from data and knowledge bases formed on this basis. An ensemble of ontological models is presented, which is the basis for the intelligent DSS being developed. The ensemble includes ontologies for equipment and materials reference databases, a library of laser processing technological operation protocols, knowledge base of settings used for laser processing and for mathematical model database. The ensemble of ontological models is implemented via the IACPaaS cloud platform. Ontologies, databases and knowledge base, as well as DSS, are part of the laser-based AM knowledge portal, which was created and is being developed on the platform. Knowledge and experience obtained by various technologists and accumulated within the portal will allow one to lessen a number of extensive trial-and-error experiments to find suitable processing settings. In the long term, the deployment of this portal is expected to reduce the qualification requirements for AM process engineers. Full article

The rolling system for stainless steel, particularly in the production of diamond plates, represents a complex industrial control scenario. The process requires precise load distribution to effectively manage pattern height, due to the high strength, hardness, and required dimensional accuracy of the material. This paper addresses the limitations of offline methods, which include heavy reliance on initial conditions, intricate parameter settings, susceptibility to local optima, and suboptimal performance under stringent constraints. A Multi-Objective Adaptive Rolling Iteration method that incorporates local constraints (MOARI-LC) is proposed. The MOARI-LC method simplifies the complex multi-dimensional nonlinear constrained optimization problem of load distribution, into a one-dimensional multi-stage optimization problem without explicit constraints. This simplification is achieved through a single variable cycle iteration involving reduction rate and rolling equipment selection. The rolling results of HBD-SUS304 show that the pattern height to thickness ratio obtained by MOARI-LC is 0.20–0.22, which is within a specific range of dimensional accuracy. It outperforms the other two existing methods, FCRA-NC and DCRA-GC, with results of 0.19~0.24 and 0.15~0.25, respectively. MOARI-LC has increased the qualification rate of test products by more than 25%, and it has also been applied to the other six industrial production experiments. The results show that MOARI-LC can control the absolute value of the rolling force prediction error of the downstream stands of the hot strip finishing rolls within 5%, and the absolute value of the finished stand within 3%. These results validate the scalability and accuracy of MOARI-LC. Full article

An overview of the steps employed to advance non-volatile Pb(Zr_xTi_1−x)O₃-based materials from parallel capacitor array test structures to embedded 130 nm (1.5 V operation) memory product release is presented. Specific development stages include parallel capacitor array evaluation, capacitor characterization array development, memory macro creation and measurement, and initial product design and qualification. Representative data, learning goals, and critical outputs will be presented for each development phase. We note that the cost and complexity of the development effort increase dramatically as the new technology approaches high-volume manufacturing. We hope that the documentation of our experiences in this manuscript may be of assistance to those teams striving to create the next generations of non-volatile embedded memory technology. Full article

Objective: The aim of this systematic review was to evaluate the effectiveness and safety of various laser wavelengths for debonding orthodontic metal brackets compared to traditional plier-based methods. The primary outcomes assessed were enamel damage, pulp temperature changes, adhesive remnant index (ARI), and shear bond strength (SBS). Materials and Methods: In September 2024, an electronic search was performed across the PubMed, Web of Science (WoS), and Scopus databases, adhering to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and the PICO framework. The initial search yielded 453 records. After eliminating 256 duplicates, 197 unique records were left for screening, which ultimately led to the qualification of 8 articles that met the inclusion criteria for both qualitative and quantitative analyses. The risk of bias in the articles was assessed by two independent reviewers. Results: The included studies demonstrated that laser-assisted debonding generally resulted in less adhesive residue on the enamel surface compared to conventional methods, as evidenced by the reductions in ARI scores reported in two studies. Temperature increases during laser use varied depending on the laser type and power settings. The Nd:YAG (neodymium-yttrium, aluminum, garnet) laser was found to cause significant temperature rises, posing a potential risk to pulp tissue, while the Er:YAG (erbium—yttrium, aluminum, garnet) and Er,Cr:YSGG (erbium, chromium—yttrium, scandium, gallium, garnet) lasers produced only negligible increases in pulp temperature. SBS comparisons revealed no significant differences between the laser-assisted and traditional debonding methods. Additionally, diode lasers demonstrated the potential to minimize enamel damage, particularly when operated at lower power settings. Four publications were assessed as high quality (low risk of bias), and another four as moderate quality (average risk of bias). Conclusions: In conclusion, laser-assisted orthodontic metal bracket debonding, when conducted with appropriately calibrated parameters, is a safe method for preserving tooth tissue. However, its advantages appear to be minimal compared to conventional plier-based methods, highlighting the need for further research to justify its broader clinical application. Full article

Background and Objectives: Sports injury prevention programs (SIPPs) are crucial for mitigating sports injuries and enhancing athletes’ performance. In Saudi Arabia, the sports sector is growing, and the awareness and implementation of sports injury prevention programs (SIPPs) among physical therapists require examination. This study aims to evaluate physiotherapists’ awareness of and the implementation of sports injury prevention programs (SIPPs) in the Saudi Arabian region with findings that could enhance rehabilitation and sports injury prevention practices. Materials and Methods: A self-administered online questionnaire was distributed to licensed physiotherapists in Saudi Arabia. Three hundred sixty-six participants responded to the questionnaire, of whom 55.5% were male and 44.5% were female physiotherapists. Results: Licensed physical therapists show a high awareness of sports injury prevention, with 83.9% agreeing or strongly agreeing. However, only 53.8% were aware of sports injury prevention programs, and 37.7% reported actively implementing them. Sports physical therapists scored significantly higher in awareness and implementation than other specialties (p < 0.001) with no significant regional differences. Educational qualification was also significant, with those holding a master’s degree or higher reporting greater awareness and implementation than those with a bachelor’s degree (p = 0.007). There was a strong positive correlation between awareness and implementation (r = 0.723, p < 0.01), along with weak correlations between awareness and perceived barriers (r = 0.270, p < 0.01) and implementation and barriers (r = 0.280, p < 0.01). Conclusions: This study finds that physical therapists in Saudi Arabia have moderate-to-low awareness and implementation of sports injury prevention programs (SIPPs), especially outside of sports-specific fields. Sports physical therapists and those with higher education have significant awareness. There are minimal regional differences but a strong positive correlation between awareness and implementation. Enhanced training, resources, and institutional support are needed to improve SIPP implementation in rehabilitation. Full article

Objectives: Parenteral drug products manufactured under GMP conditions should be visually inspected for defects and particulate contamination by trained and qualified personnel. Although personnel qualification is required, no practical protocols or formal guidelines are available for the development of qualification test sets (QTSs) used for qualification procedures. The current practice is to either procure a standardized QTS from a commercial supplier or amass sufficient manufacturing rejects during visual inspection procedures to compile in-house QTSs. However, both strategies inherently possess disadvantages and limitations. The objective of this study was to develop a manufacturing protocol for an optimal and adaptable QTS for training and qualification procedures. Methods: We combined the results of a literature search, survey of five Dutch hospital pharmacy compounding facilities, semi-structured personnel interviews, and extensive pre-GMP formulation studies to develop an optimal and adaptable QTS manufacturing protocol. Results: The literature search did not identify a manufacturing protocol for an optimal and adaptable QTS, but did identify specifications and requirements for optimal QTSs. The survey among hospital pharmacy compounding facilities revealed considerable variability in the qualification procedures and used QTSs. Semi-structured personnel interviews and pre-GMP formulation studies demonstrated that defects encountered during routine productions could be realistically simulated with pharmaceutical-grade excipients. As a proof-of-concept, we manufactured two different QTSs under GMP conditions and assessed these for formal GMP training and qualification purposes, which were considered a significant improvement compared to using manufacturing rejects. Conclusions: To the best of our knowledge, this is the first study presenting these data and our adaptable protocol, which is provided in the Supplemental Materials, may aid compounding facilities in the standardization, training, and qualification of personnel involved in visual inspection procedures. Full article

Background and Objectives: Palliative care is a very important part of medicine, aimed at ensuring an improvement in quality of life and a reduction in distressing symptoms in patients with serious, incurable, progressive diseases. The issues of the accessibility and quality of these services should be a focus for health policymakers and researchers, although it is acknowledged that a significant portion of the public has not heard about this service. For this reason, it is important to investigate the experience of the accessibility and quality of palliative care services in primary healthcare facilities. Materials and Methods: A quantitative study was conducted in institutions providing outpatient and inpatient palliative care services. A total of 784 patients and 219 family members participated in the study. Participants expressed their opinions through a questionnaire containing 24 statements, to which they responded by indicating their level of agreement on a Likert scale. The collected data were analyzed using statistical analysis software. Results: Palliative care services are widely available in large cities, but their accessibility is very limited in small towns and rural areas. Patients and their families are not familiar with the concept of palliative care, often equating it with the provision of treatment and nursing services, and they see the support of clergy as unnecessary. Although patients and their families rate the quality of the services received positively, they note shortcomings related to communication among staff. Conclusions: Palliative care services are provided within the primary healthcare system by specialists with qualifications regulated by legislation; however, patients do not see the need to receive assistance from clergy members. Based on the study results, it can be concluded that in Lithuania, the accessibility of palliative care is ensured in larger cities but is insufficient in smaller towns and rural areas. Patients tend to rate indicators reflecting the quality of palliative care services positively; however, they are not convinced that these services improve their quality of life. Full article

I describe in this paper selected aspects of the Erasmusplus Project Education for Citizenship Competence to Participation and Sustainability, performed by three European countries, in order to empower students for civic engagement through citizenship education. The partners from Italy, Spain and Romania worked from 2021 to 2023 to develop strategies and materials to enhance the qualification of teachers in civic and citizenship education to support participation of young people across Europe. The project provides new solutions to the problems identified, in order to improve civic education, to avoid the risks of indoctrination and to offer effective teaching materials, available in open access. The main products are the Toolkit with flexible teaching/educational proposals for the students and the Guidelines for the teachers, the Matrix of competences for the teachers, and the Competence Cards for the students with indicators to (self)assess the improvements. The working materials were used in the ECCOPS Learning/Teaching/Training Activities for teachers and for students, monitored through videos observed by critical friends. I discuss in this paper especially the work carried out to foster multiperspectivity, starting from the Competence Card ‘Multiperspectivity’, with the aim of preventing radicalism and fanaticism, considering different points of view on controversial topics and developing knowledge, skills and values to enable students to have a greater understanding of what makes up an effective civic participation. The most relevant project results are expected to have an impact at both institutional and practical levels in civic and citizenship education. Full article

Moulds for aeronautical applications must fulfil highly demanding requirements, including the geometrical tolerances before and after curing cycles at high temperatures and pressures. The growing availability of thermoplastic materials printed by material extrusion systems requires research to verify the geometrical accuracy after three-dimensional printing processes to assess whether the part can meet the required geometry through milling processes. In this sense, the application of automated techniques to assess quick and reliable measurements is an open point under this promising technology. This work investigates the integration of a 3D vision system using a structured-light 3D scanner, placed onto an industrial robot in an eye-in-hand configuration and synchronized by a computer. The complete system validates an in-house algorithm, which inspects the whole reconstructed part, acquiring several views from different poses, and makes the alignment with the theoretical model of the geometry of big parts manufactured by 3D printing. Moreover, the automation of the validation process for the manufactured parts using contactless detection of the offset-printed material can be used to define milling strategies to achieve the geometric qualifications. The algorithm was tested using several parts printed by the material extrusion of a thermoplastic material based on black polyamide 6 reinforced with short carbon fibres. The complete inspection process was performed in 38 s in the three studied cases. The results assure that more than 95.50% of the evaluated points of each reconstructed point cloud differed by more than one millimetre from the theoretical model. Full article

Despite the significant advances made involving the additive manufacturing (AM) of metals, including those related to both materials and processes, challenges remain in regard to the rapid qualification and insertion of such materials into applications. In general, understanding the process–microstructure–property interrelationships is essential. To successfully understand these interrelationships on a process-by-process basis and exploit such knowledge in practice, leveraging monitoring, modeling, and statistical analysis is necessary. Monitoring allows for the identification and measurement of parameters and features associated with important physical processes that may vary spatially and temporally during the AM processes that will influence part properties, including spatial variations within a single part and part-to-part variability, and, ultimately, quality. Modeling allows for the prediction of physical processes, material states, and properties of future builds by creating material state abstractions that can then be tested or evolved virtually. Statistical analysis permits the data from monitoring to inform modeling, and vice versa, under the added consideration that physical measurements and mathematical abstractions contain uncertainties. Throughout this review, the feedstock, energy source, melt pool, defects, compositional distribution, microstructure, texture, residual stresses, and mechanical properties are examined from the points of view of monitoring, modeling, and statistical analysis. As with most active research subjects, there remain both possibilities and limitations, and these will be considered and discussed as appropriate. Full article

Background and Objectives: Children with disabilities face unique challenges that can affect their well-being and quality of life (QOL). This study aimed to assess the QOL and coping strategies adopted by children with disabilities and explore how socio-demographic factors influence QOL and coping strategies. Materials and Methods: This cross-sectional study, which was conducted in Saudi Arabia with children aged 6 to 18 years, used a stratified random sample to ensure representation from a variety of demographic groups. Short Form-12 (SF-12) was used to assess the QOL in the sample population. The Brief COPE Inventory was used to examine coping strategies among the children. One-way analysis of variance was applied to examine differences in the QOL, coping strategies scores, and demographic variables. Multiple regression analyses were performed to examine the role of demographic variables in predicting QOL and p value was considered statistical significance at p < 0.05. Results: The results of the study clearly revealed significant differences between the mean scores of QOL for gender, age, and type of disability, duration of disability, education qualification, family status, family occupation, and housing status. Female participants showed better QOL in physical functioning than their male counterparts. Children with intellectual disability reported better QOL in general health, vitality, social functioning, and mental health. Participants with seven to eight years of disability reported higher scores in physical functioning, vitality, and mental health. Children whose parents were working in private agencies and living in rented houses scored higher on the general health aspects of quality of life. The findings also revealed that the duration of the disability was a significant predictor of the QOL. The mean scores of different dimensions of coping strategies clearly revealed that male participants used dysfunctional coping (p < 0.01), as compared to problem-focused and emotional-focused coping while female children relied more on emotional-focused coping. Emotion-focused coping was significantly higher in participants with visual (p < 0.01), learning (p < 0.01), and intellectual disabilities (p < 0.01). Dysfunctional coping scores were higher among children with auditory disabilities (p < 0.01) and multiple disabilities (p < 0.01). Conclusions: This study highlights the significance of demographic factors in understanding and improving the well-being of a diverse population of disabled juveniles. It offers valuable insights into the subtle factors affecting quality of life. Future interventions and policies can leverage these findings to enhance the quality of life of individuals with disabilities and to foster a more supportive and inclusive approach. Full article

In this work, a laminate based on bioresin and natural fibers was produced. Flax fabric was selected as the natural fiber. The biocomposite was subjected to strength tests. Stress–strain characteristics and strength indicators were determined. The workability of the laminate produced was also tested using milling technology. The tests were carried out using five carbide shank cutters for different purposes. The cutters with the geometry used in the processing of polymer materials and composites, general purpose cutters, and cutters with the geometry for aluminum and with different numbers of blades were analyzed. In order to obtain information on the workability of the prepared material, machining tests with different configurations of technological parameters were carried out. For each cutter, the effect of cutting speed and feed rate on the quality of the machined surface was tested. Due to the small thickness of the laminate, the machining was carried out in one pass, as a result of which the cutting depth in each case was constant. Changes in cutting speed and feed were evenly distributed over five levels. The quality of machining was assessed in two stages. The first stage included a visual assessment of the machined surface, involving a preliminary qualification of the machining parameters. The criterion was the amount of chips, frays, burrs, etc., remaining after machining that adhered to the surface. The next stage was the measurement of the geometric structure of the surface, during which the roughness parameters were analyzed using an optical microscope with a roughness analysis attachment. Quantitative analysis was performed for the best quality composite surfaces from each measurement series. The studies showed a dependence of the quality of machining on the technological parameters used. High tool speed, regardless of the type, especially at low feed, led to the sticking of chips, which had a very delicate form. In turn, low tool speed and high feed, due to the chip thickness, favored the formation of burrs. Machining with different types of tools showed that the process progresses better for tools with sharp blade geometry. Machining with a regular and polished cutter did not show any differences in the scope of the process progress. Full article

A reference material (RM), as defined by the International Vocabulary of Metrology (VIM 2012), must be homogeneous, stable, and suitable for use in measurements. Certified reference materials (CRMs) are RMs with documented property values, uncertainties, and traceability. ISO 17034:2018 outlines the requirements for RM producers, ensuring that CRMs meet standards for stability, uniformity, and reproducibility. In Europe, CE marking, from French “conformité Européenne”, which means European conformity, has been mandatory for thermal insulation products since 2002, ensuring their thermal performance is verified by accredited laboratories using RMs like IRMM440 and ERM FC440. Annually, European manufacturers produce over 200 million cubic meters of thermal insulation, necessitating thousands of thermal conductivity measurements daily to maintain CE marking compliance. Key characteristics of Reference Materials include long-term stability, thermal conductivity within specified ranges, and minimal dependence on density, thickness, and applied load. Sample thickness must conform to apparatus specifications, and homogeneity must be quantified. Reference Materials must also have appropriate dimensions, surface smoothness, and manufacturability. The Joint Research Centre (JRC) Geel has produced two Reference Materials, IRMM 440 and ERM FC 440, with specific characteristics to meet these requirements. Both are glass wool fibers with low thermal conductivity and specific density and thickness. The qualification of RMs involves inter-laboratory comparisons to ensure the accuracy and traceability of thermal conductivity measurements. The European market’s organization, including the use of Reference Materials and CE marking, has significantly improved measurement consistency and product quality. This system has led to lower uncertainties in thermal conductivity measurements compared to North America, highlighting the impact of standardized RMs on industry practices. Future needs include developing RMs with lower conductivity and increased thickness to accommodate market trends towards super insulation materials and bio-based components, enhancing energy performance calculations for buildings. This paper will present the process of defining a reference material and how it affects the uncertainty level of the calculation of building energy performance. This level depends on the characteristics of the materials used, their implementation, and external factors, such as the weather, as well as the reference material used for calibration of all European thermal conductivity measurement devices. Full article

Aim: The aim of this study was to evaluate corneal cross-linking (CXL) for keratoconus in pediatric patients. Materials and methods: After keratometric qualification according to the Amsler–Krumeich system, corneal collagen cross-linking was performed using ultraviolet light and photosensitizing riboflavin drops in 111 eyes of 74 children with a mean age of 15 ± 1.67 years. None of the children studied wore contact lenses before the procedure. Visual acuity, intraocular pressure, keratometry, and pachymetry parameters were analyzed before and after corneal cross-linking. Results: Visual acuity was 0.64 ± 0.31 and 0.66 ± 0.29 before CXL and at the end of the follow-up, respectively; the difference was not statistically significant. The mean intraocular pressure before CXL was 14.48 ± 3.13 mmHg, while the mean value at the end of the follow-up was 14.23 ± 3.03 mmHg; no statistically significant difference was found. Pre- and post-CXL astigmatism was 3.98 ± 2.34 Dcyl and 3.63 ± 1.86 Dcyl, respectively; the difference was not statistically significant. The mean keratometry before CXL was 47.99 ± 3.96 D; the mean post-follow-up value was 47.74 ± 3.63 D. The mean corneal thickness (pachymetry) at the apex of the keratoconus—the thinnest zone of the cornea—before CXL was 492.16 ± 38.75 µm, while the mean value at the end of the follow-up was 479.99 ± 39.71 µm; the difference was statistically significant. Conclusions: Corneal cross-linking is an effective method for preventing keratoconus progression in children. However, further and detailed ophthalmic follow-up of patients who underwent CXL before the age of 18 is highly advisable. Full article