Standard Language Research Articles

Do intraoral scanning technologies affect the trueness of dental arches with crowding, diastema, and edentulous spaces? A clinical perspective

ObjectivesTo evaluate the trueness of dental arches digitised by two intraoral scanning (IOS) technologies from patients presenting crowding, diastema, and bilateral posterior edentulous space with tilted molar. MethodsConventional impressions and dental stone models were generated from three patients presenting the aforementioned dental arch conditions. These models were digitised on a desktop scanner, and the resulting mesh was used as reference. Subsequently, the patients were scanned using confocal based (CF; iTero Element 2) and blue laser-multiscan (BLM; Virtuo Vivo) imaging IOS technology, totalling thirty scans. The meshes from the scans were exported in Standard Tessellation Language format and analysed using Geomagic Control X software. Root mean square (RMS) indicated deviation magnitude. Differences in IOS technologies were evaluated with paired t-tests, and dental arch conditions compared using ANOVA and post-hoc Tukey tests (α=0.05). ResultsDigital dental arch from blue laser-multiscan technology showed lower trueness compared to confocal based technology for crowding (p = 0.0084) and edentulous spaces (p = 0.0025) conditions. When the types of oral condition were compared, discrepancies were significantly different for both IOS technologies, featuring the arch with diastema showing the lowest trueness, followed by edentulous spaces and crowding. ConclusionDental arches presenting crowding and edentulous spaces digitised by blue laser-multiscan technology exhibited greater discrepancies compared to confocal based imaging technology. Furthermore, trueness varied among the dental arch conditions. Clinical SignificanceThe IOS technology and patient's dental arch condition can influence the trueness of dental arch digitisation. Being aware of these effects allows clinicians to take them into account during scanning procedures, digital planning and manufacturing.

Optimizing Regulatory Reviews for Clinical Protocols that Use Radiopharmaceuticals: Findings of the University of Pennsylvania Radiation Research Safety Committee.

Institutional radiation safety committees review research studies with radiation exposure. However, ensuring that the potential patient benefit and knowledge gained merit the radiation risks involved often necessitates revisions that inadvertently delay protocol activations. This quality-improvement study analyzed protocols, identified factors associated with approval time by a radiation safety committee, and developed guidelines to expedite reviews without compromising quality. Clinical protocols submitted to the University of Pennsylvania's Radiation Research Safety Committee (RRSC) for review between 2017 and 2021 were studied. Protocol characteristics, review outcome, stipulations, and approval times were summarized. Statistical analysis (Spearman's rho) was used to investigate stipulations and approval time; rank-sum analysis (Kruskal-Wallis or Wilcoxon) was used to determine whether approval time differed by protocol characteristics. One hundred ten (110) protocols were analyzed. Approximately two-thirds of protocols used approved radiopharmaceuticals to aid investigational therapy trials. Twenty-three percent (23%) of protocols received RRSC approval, and 73% had approval withheld with stipulations, which included requests for edits or additional information. Submissions had a median of three stipulations. Median and mean RRSC approval times were 62 and 80.1 d, and 41% of protocols received RRSC approval after IRB approval. RRSC approval time was positively correlated with stipulations (Spearman's rho = 0. 632, p < 0.001). RRSC approval time was longer for studies using investigational new drugs (median 80 d) than approved radiopharmaceuticals (median 57 d, p = 0.05). The review process is lengthy and may benefit from changes, including publishing standardized radiation safety language and commonly required documents and encouraging timely response to stipulations.

With uncertainty comes opportunity: Repurposing coal assets to create new beginnings in the U.S.

Coal power plants are retiring in the United States due to a sharp decline in natural gas prices along with an aging fleet, the rising cost of coal, and decarbonization goals. In the last five years alone (2019–2023), more than 58 gigawatts (GW) of coal power capacity retired in the United States, while almost 30 percent of the remaining 194 GW of operating capacity is expected to retire by 2040. The cessation of operations at an existing power plant can have important impacts on the local economy, including job loss and a potential reduction in total economic output. Repurposing these assets effectively, including conversion into other power generation technologies, industrial manufacturing facilities, or commercial buildings, among others, can at least partially offset any negative economic impacts. This paper provides a review of ongoing and planned repurposing activities related to former coal power plants (not including repurposing related to fuel-switching from coal to natural gas) being pursued by utilities across the United States and discusses the costs, benefits, and challenges presented by types of repurposing assets or prospects.22Some of the concepts/metrics described have standard language and the authors have tried to stick to the use of these terms for consistency. The review shows that the repurposing type and capacity of the new projects is typically unrelated to the asset type and capacity being retired. The decision to repurpose a retiring power plant or unit is a result of a combination of factors that include, among others, decommissioning costs, land availability, and financial and regulatory incentives directed towards a clean and just energy transition. A list of current planned, in-process (under construction), or completed repurposing projects for energy and non-energy alternatives is presented, including several reference examples of repurposing from fuels other than coal. Relevant factors to consider in repurposing existing retiring assets, including the relevance of incentives for retiring assets in a just energy transition, are identified and described.

Assessing the Color Stability of Polymethyl Methacrylate (PMMA) Dental Restorations Polished With a Novel Polishing Agent Derived From Pulverized Old Alginate Impressions.

Interim restorations are essential in restorative dentistry, serving as temporary solutions until permanent restorations can be placed. Polymethyl methacrylate (PMMA) is a promising solution for customizing teeth for removable dentures to match the exact requirements of patients. The color stability of these restorations is critical for patient satisfaction. PMMAis a widely used material for interim restorations due to its favorable properties. The study compares the color stability of PMMA interim restorations polished using traditional pumice versus Algishine, a novel polishing agent derived from pulverized old alginate impressions. The 3-D design software Geomagic Design X (3D Systems, Rock Hill, CA) created a standard tessellation language file of 2-cm radius circles. Sixty PMMA samples were milled and divided into two groups of 30 each. Group A samples were polished using pumice, while group B samples were polished with Algishine. Baseline color measurements were taken using a spectrophotometer (VITA Easyshade V, VITA Zahnfabrik, Bad Säckingen, Germany). The samples were then subjected to staining with coffee, tea, and red wine solutions for 30 days, simulating oral conditions. Post-staining color measurements were taken, and color changes (ΔE) were calculated at the seven-day (t1) and one-month (t2) mark. The Shapiro-Wilk test assessed normality, followed by a two-way ANOVA testto compare color change values at different time points. At t1 (seven days), there were no significant differences between groups A and B in the coffee and tea staining groups. However, significant differences were observed in red wine staining, with group B exhibiting lower ΔE values (0.14 ± 0.067) compared to group A (0.38 ± 0.076) (p < 0.01). At t2 (30 days), significant differences were noted in all staining groups. Group B consistently showed lower ΔE values: coffee (0.125 ± 0.084 vs. 0.236 ± 0.015, p < 0.01), tea (0.254 ± 0.087 vs. 0.391 ± 0.015, p < 0.01), and red wine (1.174 ± 0.045 vs. 1.309 ± 0.074, p < 0.01), indicating superior resistance to staining compared to group A. The results suggest that Algishine is more effective than pumice in maintaining the color stability of PMMA interim restorations. The novel polishing agent derived from old alginate impressions enhances esthetic longevity and provides an eco-friendly solution for recycling dental material waste. Algishine performs superiorly in preserving the color of PMMA interim restorations against common staining agents. Its application can potentially improve patient satisfaction and contribute to sustainable dental practices.

Development of a three-dimensional printed model from a digital impression of a real patient for aesthetic dentistry undergraduate teaching.

The acquisition of skills and manual dexterity in aesthetic dentistry in undergraduate teaching requires preclinical practices with simulation that should approximate real clinical situations. We will present a digital procedure for the creation of three-dimensional (3D) resin models adapted to the practices of the Aesthetic Dentistry course. Stereolithography or Standard Tesellation Language (STL) files of a real patient were previously obtained with a 3-shape intraoral scanner. Using the Exocad computer programme for dental prosthesis design, various modifications were made, such as incisor rotation, surface alterations imitating dysplasias or erosions, the creation of diastemas, or even changes in tooth size. The virtual model was printed in resin for use by students. Once the practices were finished, the students and the teachers evaluated the use of the 3D printed models. The result is the typodont model, in which seven laboratory sessions took place: 1-Restoration of conoid tooth morphology, 2-Cervical abrasion/ erosion restoration, 3-Direct Composite Veneer, 4-Aesthetic correction in a tooth with rotation, 5-Diastem closure, 6-Occlusal abrasions/ erosion, and 7-Maryland bridge. 90.48% of the students evaluated the designed 3D model as the best method for laboratory practice compared to other methods, obtaining a general assessment of 8.3 out of 10. The method used has provided a reproducible standard analog model for direct aesthetic dental restoration practice, with a good assessment by students and teachers.

False memories in bilinguals: Integration of information across languages and limits on proficiency effects.

Research on false memory in bilinguals using the DRM task has shown that false memories transfer across languages, but comparisons to within-language conditions have yielded mixed results. In two experiments, Spanish-English bilinguals completed standardized language assessments and a DRM task. Experiment 1 (N = 96) had several study-recall cycles before a final recognition test, and Experiment 2 (N = 72) only tested recognition. Relative to within-language conditions, more critical lures were recalled when the language changed from study to test and when words were studied in mixed-language sequences. With no prior recall test, the rate of critical lure recognition did not differ across language conditions. Language proficiency was not associated with the false-memory effects. Associations of false and veridical memory were negative in recall and positive in recognition. Overall, the findings indicate that proficient bilinguals can integrate information across their languages via a shared semantic network to form false memories.

THE IDEOLOGY OF NATIONAL EDUCATION CELEBRATION SPEECH: A CRITICAL DISCOURSE ANALYSIS OF TEXT

This study aims to discover critical discourse analysis in the text of speeches by Nadiem Makarim and Muhadjir Effendy. The speeches of these two figures were chosen because the text is a kind of Critical Discourse Analysis object (CDA). The Critical Discourse Analysis (CDA) method examines the relationship between language, ideology, and power. The descriptive qualitative method was used in this study. The researcher uses Norman Fairclough's three-dimensional framework (CDA) to analyze Critical Discourse Analysis data. The researchers used qualitative data analysis theory from Miles and Huberman (1994) to present and analyze the data, which included data reduction, data display or representation, and conclusion drawing or verification. The result of this study shows that both the script of speeches from Nadiem Makarim and Muhadjir Effendy have micro, mezzo, and macro-level related to the framework of Norman Fairclough. The language used in both speeches is the standard language. Still, the speech of Nadiem Makarim used more natural and creative language that can touch the millennial generations. In contrast, in the speech of Muhadjir, familiar words can confuse the audience.

Graph Theory to Map Nursing Knowledge of Diagnosis and Interventions in Women's Health.

Apply Graph Theory to analyze and map knowledge about nursing diagnoses and interventions, based on records of consultations carried out by nurses, in women's health, in primary health care. Secondary data from a cross-sectional study were used. Records of nursing consultations carried out during the month of October 2016, in 21 health units, in a Brazilian municipality were analyzed. Network analysis was carried out using Graphs from 61 nursing consultations. 175 diagnoses were recorded, an average of three per consultation; and 380 interventions, an average of six per consultation. In the analysis, four diagnostic and four intervention network groupings were identified. The mapping allowed reflection on phenomena of interest to Nursing and fostering critical thinking in decision making. The findings are useful for teaching and training nurses, as well as strengthening the use of standardized language systems.

Kinyarwanda Language Change: A Prescriptivism Perspective of Selected Settings

With the advancement of technology, language change has gained a stronghold among the 21st century linguistic studies. Language change is generally fueled by diverse factors. Generation by generation, pronunciations evolve, new words are borrowed, others are invented, the meaning of old words drifts, and morphology develops or decays. In this study, the researchers explore factors pertaining to Kinyarwanda language change in the post-1994 Genocide period, with particular focus on lexicosemantic features. The study is framed in prescriptivism, which holds that there are correct and wrong ways of using language. Both written and spoken data was collected from various public places and social media sources, where Kinyarwanda is widely used on different occasions. Contextual data analysis was carried out, taking into consideration the general use of standard Kinyarwanda. Findings highlight that Kinyarwanda is negatively affected by historical, technological, and social factors that impede the respect of the prescribed rules of the standard Kinyarwanda language. The study recommends that efforts be made to cope with the identified critical factors so as to preserve Kinyarwanda, which is not only means of communication, reflection of people’s culture and identity but also an official and academic language in the Rwandan context and even beyond it.

Abbreviations in SMS Messages in the Bosnian Language

The paper presents the abbreviations used in SMS messages in the Bosnian language. Abbreviations recorded in the analyzed corpus are diverse in origin, shortening mechanisms, and morphological and syntactic features. Recognized abbreviations are first classified according to the type of shortened units – into abbreviations formed from words (nouns, adjectives, pronouns, numbers, verbs, adverbs, prepositions, conjunctions, particles) and abbreviations formed from groups of words, sentences, or utterances. Within the classes defined in that way, abbreviations are divided about the mechanism of shortening and described. Abbreviations in SMS messages are in some cases formed by the norms of the standard language but usually deviate from the standard forms. The same words and constructions can be abbreviated in several different ways, and abbreviations most often vary in terms of the use of upper and lower case letters as well as the writing or omission of a period at the end. Abbreviations are most often created by final elision, i.e. by omitting the end of the word and reducing the word to the beginning. They are also created by reducing the word to the first letter and some other meaningful letters inside the word or at the end of the word. In the corpus, not a single word of the Bosnian language was found in which numbers and letters are used as logograms or are incorporated into larger expressions that are read as rebuses. A particularly interesting phenomenon in shortening is the unmotivated multiplication of graphemes at the end of some abbreviations. A significant number of abbreviations created by dropping vowels and some consonants or reducing them to only some consonants are confirmed in the corpus.

Beyond seeking equivalents: exploring Chinese master’s students’ use of machine translation as a translanguaging process in EAP writing

ABSTRACT Purpose This study employs the translanguaging theory to explore how Chinese master’s students use machine translation (MT) as part of their semiotic and spatial repertoires in the English for academic purpose (EAP) writing process. Design The study gathered data through interviews, field observations, screen recordings, artifacts of written texts, and post-class conversations to show students’ use of MT and their perceived affordances and constraints. The data were subject to thematic analysis. Findings Students flexibly employed their biliteracy and digital literacy to improve MT outputs. They also integrated MT with other semiotic and spatial resources, which empowered their negotiation of linguistic and cultural differences. However, the challenges for the translanguaging approach to using MT arose from the emphasis on monolithic language standards over students’ rhetorical agency and linguistic flexibility in the EAP educational context. Originality/value This study reveals that multilingual learners could draw upon the full range of their meaning-making toolkits, encompassing linguistic, semiotic, and cultural resources with spatial affordance in their MT engagement in EAP writing. The study suggests that EAP education should value students as bilingual/multilingual authors who can compose with a broad spectrum of linguistic, multimodal, and spatial resources, with MT being a key component, to enrich their learning practices.

Trueness of the apical and middle root portion segments of 3D-printed removable die and alveolar cast designs manufactured using stereolithographic 3D printing.

The present study evaluated the effects of the root portion design, segment (middle vs. apical), and part (die vs. cast) on the trueness of three-dimensional (3D)-printed removable die-cast complex. The trueness of apical and middle segments of the root portion of 45 3D-printed removable dies and casts with three different root portion designs (n = 15) was assessed using a metrology-grade computer program. The three removable dies and cast designs (root form [RF], conical [CON], and cylindric [CYL]) were created using professional computer-aided manufacturing computer programs (DentalCAD 3.1 Rijeka, and InLab CAD 22.0), and manufactured using stereolithographic 3D printer (Form3; FormLabs, Somerville, MA). Subsequently, the 3D-printed removable dies and casts were scanned by a single operator with an intraoral scanner (PrimeScan; Dentsply Sirona, Charlotte, NC), and their respective standard tessellation language files were aligned and compared to master reference files in a metrology-grade computer program (Geomagic Control X; 3D systems, Rock Hill, NC). The root mean square (RMS) values of the middle and apical segments for each removable die and cast were calculated and analyzed using a mixed model including a repeated measure 3-way analysis of variance (ANOVA) and post-hoc stepdown Bonferroni-corrected pairwise comparisons (α = 0.05). A statistically significant 3-way interaction between factors was detected, suggesting that the part (removable die or alveolar cast) and their design affected the RMS values of their apical and middle root portion segment. (p = 0.045). The post-hoc analysis identified significant differences between RMS values of the apical segments of the CON and CYL removable dies (p = 0.005). Significant differences were observed between the middle and apical segments of the CON (p < 0.001) and RF removable die designs (p = 0.004). No statistically significant differences were noticed between the RMS of the different alveolar cast designs (p > 0.05). Significant differences were detected between the apical and middle segments of the same alveolar cast design (p < 0.05). For the manufacturing trinomial and 3D printing strategy used in the present study, the interaction of the part, design, and segment affected the trueness of removable dies and alveolar casts. The trueness was higher on the middle segment on removable dies and alveolar casts in all designs used, except for CYL removable dies, where the trueness difference between segments was small. Higher trueness values may be achieved with designs with simple apical segment geometries.

Canadian national sport organisations’ eating disorder-related policies and practice guidelines: a summative content analysis

ABSTRACT Athletes are at significant risk of developing eating disorders (EDs). To address EDs in sport, policies can support the prevention, management, and return to sport following EDs. Although Canadian National Sport Organisations (NSOs) must comply with a universal code of conduct to address maltreatment in sport, there may be a need for additional policies and guidelines to address EDs. The purpose of this study was to examine the scope and content of ED-related policies and practice guidelines within Canadian NSOs. We searched all publicly available policy and guideline documents from Canada’s 64 NSOs and screened them for keywords related to disordered eating, body image, nutrition, diet, and exercise, yielding 98 policies and 39 guidelines. We conducted a summative content analysis to examine the contextual use of our keywords and the sociocultural implications of such use. No NSO had specific policy or practice guidelines addressing EDs. Policies described body shaming-related maltreatment using standard language from the universal code of conduct. Within guidelines, ED-related topics were discussed in relation to mental health, athlete development, nutrition, coaching female athletes, positive body image, and weight management. Comparing content within policies and guidelines revealed a lack of coherence, wherein policies outlined ‘what not to do’ but guidelines did not provide adequate guidance on ‘what to do’, drawing instead on weight-normative and gendered discourse to address ED topics. This study provides insight into the current state of systemic (in)action surrounding EDs in Canadian sport and serves as a preliminary step towards the development of ED policy.

Custom fabricated three-dimensional printed surgical guide for trephine bur in autogenous bone graft: A technique report.

This technique presents a workflow that designs the custom surgical guide to cover a trephine bur using simple slicer software and three-dimensional (3D) printing to perform the semilunar technique. This method in autogenous bone grafting surgery harvests a thin layer of cortical bone in the donor site with a trephine bur. Its biologically favorable, round shape can be used as a shell to reconstruct the ridge with a 3D contour acceptable for future implant placement. A 78-year-old female patient required vertical and horizontal bone grafting for future implant placement due to the infection caused by the vertically fractured root of a premolar. The patient's cone beam computed tomography (CBCT) file was translated into a standard tessellation language (STL) file, and recipient and donor site models were created. Simulated surgery was done using the software first to detect any possible complications during surgery. The trephine bur planned for use in surgery was measured in necessary dimensions, and the values were added to create a guide for surgery in slicer software. Then, it was 3D-printed with a stereolithography (SLA) printer. After testing the fit of the guide, it was further tested on a fused filament fabrication (FFF) printed donor site model to check if the desired shape and size of the plate were acquired after harvest. Then, the plates were used for model surgery on the recipient site model. After no issues from the previous steps, the final patient surgery was approved and completed with success. This technique utilizes the SLA printing method to create the custom surgical guide for a trephine bur without using commercially available products. Moreover, it could be tested on FFF 3D-printed anatomical models to ensure its validity. With this innovative technique, clinicians can efficiently perform a semilunar technique, facilitating the surgery and improving patient care.

Defining accurate terminology for post-injury weightbearing instructions - a multidisciplinary, nationally approved consensus policy.

Weightbearing instructions after musculoskeletal injury or orthopaedic surgery are a key aspect of the rehabilitation pathway and prescription. The terminology used to describe the weightbearing status of the patient is variable; many different terms are used, and there is recognition and evidence that the lack of standardized terminology contributes to confusion in practice. A consensus exercise was conducted involving all the major stakeholders in the patient journey for those with musculoskeletal injury. The consensus exercise primary aim was to seek agreement on a standardized set of terminology for weightbearing instructions. A pre-meeting questionnaire was conducted. The one-day consensus meeting, including patient representatives, identified three agreed terms only to be used in defining the weightbearing status of the patient: 1) non-weightbearing; 2) limited weightbearing; and 3) unrestricted weightbearing. This study represents the first and only exercise in standardizing rehabilitation terminology in orthopaedics, as agreed by all major stakeholders in the patient pathway and the patients themselves. The standardization of language allows for higher-quality and more accurate research to be conducted, and is one small part of the bigger picture in increasing the mobility of patients after orthopaedic injury or surgery.

Assessing the Language Abilities of Preterm-Born Children: An Examination of Standardized Testing and Language Sample Analysis.

To understand how best to assess the language abilities of preterm-born children, this study: (a) compared preterm- and term-born children's language skills using standardized testing and language sample analysis (LSA), (b) investigated how executive function skills and the language sampling context respectively affect standardized test and LSA scores, and (c) examined the pattern of associations between standardized test and LSA scores among preterm-/term-born groups. Twenty-five term-born and 23 preterm-born 2-year-old singletons were administered the language scales of the Bayley Scales of Infant and Toddler Development-Third Edition (receptive communication, expressive communication, language composite scores). Parent-child free-play recordings were used to quantify the (para)linguistic features of the children's speech. Executive function was measured via parent report. The preterm-born group obtained significantly lower scores than the term-born group on all Bayley language measures (though differences were not consistently observed when using cutoff scores). Few preterm-term differences in LSA measures were found. The preterm-term differences in Bayley scores were not explained by between-group differences in executive function. Some preterm-term differences in LSA scores were moderated by the language sampling context. The preterm- and term-born groups exhibited different patterns of Bayley-LSA correlations. Preterm language difficulties were more apparent on standardized test than LSA scores. Nonetheless, the Bayley-LSA correlations indicate that poor test performance (linked with preterm birth) is associated with functional communication difficulties. The discussion outlines the complementary utility of standardized tests and LSA while acknowledging the limited utility of cutoff scores and the confounding influence of the language sampling context. https://doi.org/10.23641/asha.26142661.

DEVELOPING COMMUNICATIVE COMPETENCE OF STUDENTS AT ENGLISH LESSONS

In the article the importance of developing communicative competence of students at English lessons, as one of the backgrounds for forming an individual is considered. The recent studies of solving this issue, as one of the necessary conditions in learning a foreign language, are overviewed. In the article the notion “communicative competence” and its components are determined: grammatical competence, discourse competence, that is the ability to build sentences in discourse for the purpose of forming meaningful integrity from a set of utterances, sociolinguistic competence, which lies in understanding the right usage of language standards, that depend on a particular context and strategic competence, which determines language techniques, that are used when interlocutors have a communication gap as a result of imperfect language knowledge. These techniques include: correction, paraphrase, parable, repetition and pause. The article exercises, tasks for developing communicative competence worked out by its author. Special attention is paid to the brainstorming activities, as an example, the author gives spidergram “Teacher”. The developed approach allows to monitor communicative competence development of students and to fulfil additional methodological approaches for developing creative activities of students.

Evaluation of the accuracy of conventional and digital implant impression techniques in bilateral distal extension cases: a randomized clinical trial

BackgroundThis clinical study aims to evaluate the accuracy of the conventional implant impression techniques compared to the digital impression ones in bilateral distal extension cases.MethodsA total of 32 implants were placed in eight patients missing all mandibular posterior teeth except the first premolars. Each patient received a total of four implants, with two implants placed on each side, in order to provide support for three units of screw-retained zirconia restorations. Following osteointegration, the same patient underwent two implant-level impression techniques: Conventional open-tray impressions CII (splinted pick-up) and digital implant impressions DII with TRIOS 3 Shape intraoral scanner. The accuracy of impressions was evaluated utilizing a three-dimensional superimposition analysis of standard tessellation language (STL) files. Subsequently, the scan bodies were segmented using Gom inspect software to measure three-dimensional deviations in a color-coding map. Data were statistically analyzed using the Kruskal Wallis test and then a post-hoc test to determine the significance level (P < 0.05).ResultsThe study revealed that higher angular and positional deviations were shown toward distal scan bodies compared to mesial ones for both impression techniques. However, this difference was not statistically significant (P > 0.05).ConclusionSplinted open-tray conventional impression and intraoral scanning implant impression techniques have demonstrated comparable accuracy.Trial registrationClinical Trials.gov Registration ID NCT05912725. Registered 22/06/ 2023- Retrospectively registered, https://register.clinicaltrials.gov.

Lingua francas as evidence of standard language ideology in historical perspective

Lingua francas as evidence of standard language ideology in historical perspective

A Cost-effective approach for quality control in PLA-based material extrusion 3D printing using 3D scanning

In this article, our aim is to underscore the importance of verifying that components produced through material extrusion additive manufacturing exhibit geometric and dimensional conformity with the STL (Standard Tessellation Language) model. Currently, the business world is heavily investing in additive technologies, but it is crucial to obtain feedback on the accuracy of the printed component without excessive economic expenditure. For this reason, we have opted to utilize a mid-range 3D scanner (Revopoint Mini with an accuracy of 0.02 mm) to investigate any disparities in print results using PLA material. Each model has been scanned and compared with the initial mesh to qualitatively and quantitatively assess the present errors. The analysis has revealed that the majority of features can be effectively controlled, while the remaining ones either fall within the tool's precision or necessitate a higher-quality scan. Particularly in the analysed case, flat surfaces, profiles of complex geometries, and holes have demonstrated dimensional and geometric controllability. However, details of reduced dimensions or those difficult to reach by the scanner do not allow for adequate comparison due to excessive standard deviation in the error. The analysed layer heights do not exhibit a significant impact on component accuracy.