bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transient Melt Pool Formation in Laser-Powder Bed Fusion Process
Authors: Rauniyar Santosh , Chou Kevin 
Published: January 2021

Abstract
Parts are built in a layer-by-layer fashion in the laser powder bed fusion process. Each layer of scan in the parts is defined by a scan strategy that consists of many small patches and scans. The scan length of those multiple scans is not always long enough to have reached a quasi-steady state of the melt pool. The length at which it achieves a steady state is different for different process parameters. The available literature related to the melt pool considers the melt pool has already achieved a steady state, which holds true to a large extent. However, there is always a transient state of melt pool with different characteristics compared to the quasi-steady state. The transient state of the melt pool is particularly significant for small features and thin walls. This paper explores the cross-section and width of the melt track in the transient state. Single-tracks are deposited on semi-cylindrical samples with Ti-6Al-4V powder particles for three levels of power and speed combinations. The single tracks are built at a certain height from the base plate instead of on the build plate to include the effect of the powder particles. The experiment includes single tracks of four scan lengths i.e. 0.25, 0.5, 1 and 2 mm. Once the parts are built and removed from the build plate, White light interferometer is used to capture the melt track information and data processing is done in Matlab™. The results show that the transient length is directly proportional to the laser power and inversely proportional to the scan speed. The highest transient length value is obtained for the highest power of 195 W and lowest scan speed of 50 mm/s.
Fault Diagnosis of Timed Event Systems: An Exploration of Machine Learning Methods
Authors: Cohen Joseph , Jiang Baoyang , Ni Jun 
Published: January 2021

Abstract
Especially common in discrete manufacturing, timed event systems often require a high degree of synchronization for healthy operation. Discrete event system methods have been used as mathematical tools to detect known faults, but do not scale well for problems with extensive variability in the normal class. A hybridized discrete event and data-driven method is suggested to supplement fault diagnosis in the case where failure patterns are not known in advance. A unique fault diagnosis framework consisting of signal data from programmable logic controllers, a Timed Petri Net of the normal process behavior, and machine learning algorithms is presented to improve fault diagnosis of timed event systems. Various supervised and unsupervised machine learning algorithms are explored as the methodology is implemented to a case study in semiconductor manufacturing. State-of-the-art classifiers such as artificial neural networks, support vector machines, and random forests are implemented and compared for handling multi-fault diagnosis using programmable logic controller signal data. For unsupervised learning, classifiers based on principal component analysis utilizing major and minor principal components are compared for anomaly detection. The rule-based extreme random forest classifier achieves the highest validation accuracy of 98% for multi-fault classification. Likewise, the unsupervised learning approach shows similar success, yielding anomaly detection rates of 98% with false alarms under 3%. The industrial feasibility of this method is notable, with the results achieved with a training set 99% smaller than the supervised learning classifiers.
A Machine Learning Approach to Model the Electrospinning Process of Biocompatible Materials
Authors: Toscano Juan Diego , Li Zebin , Segura Luis Javier , Sun Hongyue 
Published: January 2021

Abstract
Electrospinning is a manufacturing technique that can produce microfibers and nanofibers from polymeric solutions. It has a broad range of applications in areas such as tissue engineering, flexible electronics, filtering, etc. However, due to its chaotic behavior, the fibers obtained by this process are prone to high diameter variations. The high diameter variations will cause poor final product functionality. The diameter is affected by process variables, ambient conditions and in-situ measurements. It is therefore important to model their effect on the fiber diameter variation, which is rarely investigated in the literature. Towards this end, this paper systematically studies the electrospinning process of a biocompatible polymer (i.e., polyacrylonitrile (PAN) 10%) via experimental study and data-driven modeling. In particular, three critical process variables (i.e., voltage, tip-to-collector distance, and polymer flow rate), are varied in a central composite design of experiment. Twenty-four runs are executed for the data collection, during which the in-situ measurements are collected via a customized sensing system. After each experiment, scanning electron microscope (SEM) images are taken from the nonwoven mats and characterized to capture the diameter and the diameter variations. Three machine learning methods, Lasso, random forest (RF), and support vector machine (SVM), are applied to the collected data. The model performance is evaluated in the real case study on the electrospinning of polymeric solution. The most predictive model (RF) can yield an around 15% relative error for prediction in testing data on average over 100 replications.
Investigation of Circuit Parameters in Tube Electrode High-Speed Electrochemical Discharge Machining
Authors: Zhang Yan , Rashedul Islam Md. , Ji Lei , Jiang Baoyang 
Published: January 2021

Abstract
Tube electrode high-speed electrochemical discharge machining (TSECDM) has been effectively used in the manufactures of micro holes with difficult-to-cut conductive materials in the field of aerospace industry. The design and parameters of circuit are critical for the machining performances of TSECDM. In this paper, the influences of circuit on the TSECDM performances are studied. Firstly, a relaxation type RLC generator is designed and analyzed by MATLAB simulation. Secondly, the effects of RLC circuit parameters such a resistor (R), capacitor (C) and inductor (L) on machining performances are investigated by experiments on the bulk of SS304 alloys by limiting factors changing. Finally, the analysis achievement indicated that the circuit selection parameters value R (15Ω); C (220nF); L (0.13mH) can be used to obtain a better machining performance.
Surrogate Pore Generations in L-PBF Ti64 and Effects on Mechanical Behavior
Authors: Zhang Shanshan , Chertmanova Sabina , Chou Kevin 
Published: January 2021

Abstract
In this study, surrogate pores were designed and generated at specific locations inside tensile specimens fabricated by laser powder bed fusion (L-PBF) processing and further evaluated in porosity characteristics and mechanical properties. The objectives are to demonstrate the feasibility of pore generation and to characterize the pores and examine the effect from various process conditions. The pore-generated specimens were fabricated in an L-PBF system using Ti-6Al-4V (Ti64) powder. Overall, specimens were made using default settings. But, during processing the middle section of the tensile specimens, single track exposures were applied to induce keyhole pores with different energy density levels as well as different scan track numbers and layers. An X-ray computed tomography system was utilized to measure and analyze surrogate pores in the fabricated specimens in pore counts, volumes and sphericity related to process conditions. The results showed that, as expected, pore formation increases with the laser energy density applied and the number of tracks and layers exposed, although individual tracks exhibit a high variability. Specimens evaluated by tensile testing and fractography show that surrogate pores produced in this study so far influence only the ductility of the specimens noticeably, but not Young’s modulus, nor the yield and tensile strengths.
Vision-Based Precision Deburring and Edge Breaking Process Quality Control
Authors: Gupta Kartik , Grimm Cindy , Sencer Burak , Balasubramanian Ravi 
Published: January 2021

Abstract
This paper presents a computer vision system for evaluating the quality of deburring and edge breaking on aluminum and steel blocks. This technique produces both quantitative (size) and qualitative (quality) measures of chamfering operation from images taken with an off-the-shelf camera. We demonstrate that the proposed computer vision system can detect edge chamfering geometry within a 1–2mm range. The proposed technique does not require precise calibration of the camera to the part nor specialized hardware beyond a macro lens. Off-the-shelf components and a CAD model of the original part geometry are used for calibration. We also demonstrate the effectiveness of the proposed technique on edge breaking quality control.
Experimental Study on Cost-Effective Additive Manufacturing of Silica Aerogel
Authors: Guo Zipeng , Yang Ruizhe , Wang Tianjiao , An Lu , Ren Shenqiang , Zhou Chi 
Published: January 2021

Abstract
The conventional manufacturing process of aerogel insulation material relies largely on the supercritical drying, which suffers from issues of massive energy consumption, high-cost equipment and prolonged processing time. With the consideration of large market demand of the aerogel insulation material in the next decade, a low-cost and scalable fabrication technique is highly desired. In this paper, a direct ink writing (DIW) method is used to three-dimensionally fabricate the silica aerogel insulation material, followed by room-temperature and ambient pressure drying. Compared to the supercritical drying and freeze-drying, the reported method significantly reduces the fabrication time and costs. The cost-effective DIW technique offers the capability to print complex hollow internal structures, coupled with the porous structure, is found to be beneficial to the thermal insulation property. The addition of fiber to the ink assures the durability of the fabricated product. The foam ink preparation methods and the printability are demonstrated in this paper, along with the printed samples for characterizing thermal insulation performance and mechanical properties.
Small-Groups Versus Full-Class Exergaming on Urban Minority Adolescents’ Physical Activity, Enjoyment, and Self-Efficacy
Authors: McDonough Daniel J. , Liu Wenxi , Su Xiwen , Gao Zan 
Published: January 2021

Background: The effects of school-based exergaming interventions on adolescents’ physical activity (PA) and psychosocial outcomes have been mixed. Researchers speculate this may be attributed to design issues. Therefore, this study examined differences in urban minority adolescents’ PA, enjoyment, and self-efficacy during small-groups and full-class exergaming.Methods: Forty-seven urban minority adolescents (83% black;) completed two 15-minute exergaming sessions on the Xbox One Kinect Just Dance: (1) small groups (n = 3–4) and (2) full class (n = 23–24). Participants’ time in sedentary behavior, light PA, and moderate to vigorous PA and steps were retrieved from ActiGraph GT3X+ accelerometers with enjoyment and self-efficacy assessed using validated surveys.Results: Participants spent significantly more time in sedentary behavior (5.9 [5.2] min vs 3.5 [2.7] min, respectively:P < .001,d = 0.57) and less time in moderate-to-vigorous PA (2.1 [2.8] min vs 5.5 [2.2] min, respectively:P < .001,d = 0.85) during the full-class versus the small-groups session. Moreover, small-groups exergaming resulted in significantly higher steps than the full-class exergaming (504.2 [132.1] vs 387.8 [122.1], respectively:P = .01,d = 0.50) and significantly greater enjoyment (3.5 [1.1] vs 3.2 [1.0], respectively:P = .02,d = 0.37). There were no significant differences between sessions for time in light PA and self-efficacy.Conclusions: Small-groups exergaming appears ideal for promoting enjoyable PA at higher intensities and lower sedentary time in underserved minority adolescents.
The convexity of carbonate hilltops: 36Cl constraints on denudation and chemical weathering rates and implications for hillslope curvature
Authors: Ben-Asher Matan , Haviv Itai , Crouvi Onn , Roering Joshua J. , Matmon Ari 
Published: January 2021

Abstract
Carbonate hillslopes are often soil mantled and display a classic convex morphology. In this study we examine controls on carbonate hillslope denudation and morphology using a modified regolith mass balance equation to account for chemical weathering and dust input—two fluxes that are commonly neglected in settings with silicate-dominated bedrock. We utilize seven study sites in the Eastern Mediterranean across a significant gradient in the mean annual rainfall and dust deposition flux. Combining cosmogenic 36Cl-derived hilltop denudation rates with an estimate of the regolith chemical depletion and the quantified fraction of dust in the regolith we predict hilltop curvature and compare our predictions with observations based on high-resolution airborne LiDAR (light detection and ranging).
Denudation rates vary from 5 to 210 mm/k.y. and increase with mean annual rainfall. Less resistant carbonates (chalk) experience faster denudation rates relative to more resistant dolo-limestone and are less prone to chemical weathering. Soil production exhibits a humped dependency on soil thickness.
The observed hilltop curvature varies as a function of rainfall and dust flux with a minimum at sub-humid sites. While trends in hilltop convexity are often solely attributed to variations in erosion rate, our results illustrate the additional effects of dust production and chemical depletion. Our mass balance model implies that drier sites in the south probably experienced a more intricate history of regolith production due to dust flux fluctuations. Thus, by incorporating dust flux and chemical weathering to the classic hillslope evolution model we are able to identify a complex relation between hilltop curvature, soil production, and climate.
Evaluation of an OPEN Stewardship generated feedback intervention to improve antibiotic prescribing among primary care veterinarians in Ontario, Canada and Israel: protocol for evaluating usability and an interrupted time-series analysis
Authors: Acharya Kamal Raj , Brankston Gabrielle , Soucy Jean-Paul R , Cohen Adar , Hulth Anette , Löfmark Sonja , Davidovitch Nadav , Ellen Moriah , Fisman David N , Moran-Gilad Jacob , Steinman Amir , MacFadden Derek R , Greer Amy L 
Published: January 2021

IntroductionAntimicrobial resistance (AMR) impacts the health and well-being of animals, affects animal owners both socially and economically, and contributes to AMR at the human and environmental interface. The overuse and/or inappropriate use of antibiotics in animals has been identified as one of the most important drivers of the development of AMR in animals. Effective antibiotic stewardship interventions such as feedback can be adopted in veterinary practices to improve antibiotic prescribing. However, the provision of dedicated financial and technical resources to implement such systems are challenging. The newly developed web-based Online Platform for Expanding Antibiotic Stewardship (OPEN Stewardship) platform aims to automate the generation of feedback reports and facilitate wider adoption of antibiotic stewardship. This paper describes a protocol to evaluate the usability and usefulness of a feedback intervention among veterinarians and assess its impact on individual antibiotic prescribing.Methods and analysisApproximately 80 veterinarians from Ontario, Canada and 60 veterinarians from Israel will be voluntarily enrolled in a controlled interrupted time-series study and their monthly antibiotic prescribing data accessed. The study intervention consists of targeted feedback reports generated using the OPEN Stewardship platform. After a 3-month preintervention period, a cohort of veterinarians (treatment cohort, n=120) will receive three feedback reports over the course of 6 months while the remainder of the veterinarians (n=20) will be the control cohort. A survey will be administered among the treatment cohort after each feedback cycle to assess the usability and usefulness of various elements of the feedback report. A multilevel negative-binomial regression analysis of the preintervention and postintervention antibiotic prescribing of the treatment cohort will be performed to evaluate the impact of the intervention.Ethics and disseminationResearch ethics board approval was obtained at each participating site prior to the recruitment of the veterinarians. The study findings will be disseminated through open-access scientific publications, stakeholder networks and national/international meetings.
Incidence of HIV and HCV in people who inject drugs: a systematic and meta-analysis review protocol
Authors: Sharhani Asaad , Jorjoran Shushtari Zahra , Rahmani Azam , Armoon Bahram , Noroozi Mehdi , Ahounbar Elaheh , Karimi Salah Eddin , Higgs Peter 
Published: January 2021

IntroductionHIV and hepatitis C virus (HCV) are major health concerns globally. This systematic review and meta-analysis protocol study aims to estimate the incidence of HIV and HCV among people who inject drugs (PWIDs) by reviewing studies that have applied mathematical modelling. The primary purpose of this systematic review is to identify and review mathematical modelling studies of HIV and HCV incidence in PWIDs.Methods and analysis cohort, cross-sectional and clinical trial studies conducted to estimate the incidence of HIV and HCV based on mathematical models or have evaluated the effectiveness of mathematical models will be considered for inclusion in the review. A comprehensive search applying a Cochrane approach will be used to identify relevant primary studies, published between January 2000 and July 2020, and indexed in PubMed, EMBASE, Opengrey, WOS, SCOPUS and Cochrane Library with no restriction on language. This protocol was prepared according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). Study selection and data extraction will be performed by two independent reviewers. Assessment of risk of bias will be implemented using forms of the Critical Appraisal Skills Programme. Publication bias will be assessed by funnel plots, Begg’s and Egger’s tests. A meta-analysis will be conducted to answer the first research question, ‘What is the incidence of HIV and HCV when applying mathematical model in PWID?’. Clinical heterogeneity will be assessed by looking at the characteristics of participants, method of diagnosis and case definitions in the included primary studies. In addition, subgroup analyses will be conducted for population and secondary outcomes.Ethics and disseminationThere are no ethical issues related to this study. The findings will be published in peer-reviewed scientific journals and presented at international and national conferences.PROSPERO registration numberCRD42019126476.
Instantaneous wave-free ratio guided multivessel revascularisation during percutaneous coronary intervention for acute myocardial infarction: study protocol of the randomised controlled iMODERN trial
Authors: Beijnink Casper W H , Thim Troels , van der Heijden Dirk Jan , Klem Igor , Al-Lamee Rasha , Vos Jacqueline L , Koop Yvonne , Dijkgraaf Marcel G W , Beijk Marcel A M , Kim Raymond J , Davies Justin , Raposo Luis , Baptista Sérgio B , Escaned Javier , Piek Jan J , Maeng Michael , van Royen Niels , Nijveldt Robin 
Published: January 2021

IntroductionRecent randomised clinical trials showed benefit of non-culprit lesion revascularisation in ST-elevation myocardial infarction (STEMI) patients. However, it remains unclear whether revascularisation should be performed at the index procedure or at a later stage.Methods and analysisThe instantaneous wave-free ratio (iFR) Guided Multivessel Revascularisation During Percutaneous Coronary Intervention for Acute Myocardial Infarction trial is a multicentre, randomised controlled prospective open-label trial with blinded evaluation of endpoints. After successful primary percutaneous coronary intervention (PCI), eligible STEMI patients with residual non-culprit lesions are randomised, to instantaneous wave-free ratio guided treatment of non-culprit lesions during the index procedure versus deferred cardiac MR-guided management within 4 days to 6 weeks. The primary endpoint of the study is the combined occurrence of all-cause death, recurrent myocardial infarction and hospitalisation for heart failure at 12 months follow-up. Clinical follow-up includes questionnaires at 3 months and outpatient visits at 6 months and 12 months after primary PCI. Furthermore, a cost-effectiveness analysis will be performed.Ethics and disseminationPermission to conduct this trial has been granted by the Medical Ethical Committee of the Amsterdam University Medical Centres (loc. VUmc, ID NL60107.029.16). The primary results of this trial will be shared in a main article and subgroup analyses or spin-off studies will be shared in secondary papers.Trial registration numberNCT03298659.
Symptom Screening in Pediatrics Tool in children and adolescents with high-risk malignancies: a pilot study
Authors: Szepetowski Sarah , Saultier Paul , Andre Nicolas , Pauly Vanessa , Dupuis L. Lee , Sung Lillian , Revon-Rivière Gabriel 
Published: January 2021

ObjectiveChildhood and adolescent cancer can result in high burden of distressing symptoms, particularly in high-risk malignancies. The Symptom Screening in Pediatrics Tool (SSPedi) is a reliable and valid approach to measure bothersome symptoms in paediatric patients receiving cancer treatments. Objective was to describe the feasibility of using SSPedi administration among paediatric patients with high-risk malignancies.MethodsWe conducted a single-centre, cross-sectional study of patients aged 8–18 years with high-risk malignancies in a French paediatric oncology unit. Patients self-reported the degree of bothersome symptoms using SSPedi and difficulty with SSPedi completion. The total SSPedi Score ranging from 0 to 60 (where 60 is worst) and most common moderately bothersome symptoms (scored ≥2 on 0–4 Likert Scale) were described. Feasibility was defined as more than 75% of patients agreeing to participate and more than 90% completion of SSPedi questionnaire.ResultsOut of 16 patients approached, 1 declined participation. Median age was 13 years (IQR 8–19). All were able to self-report SSPedi without difficulty. Patients experienced a median number of 6 (range 0–15) bothersome symptoms (score >0). The mean total SSPedi Score was 12 (SD=9.4). Most common moderately bothersome symptoms were pain (8/15), changes in hunger (8/15) and feeling tired (7/15).ConclusionPatient-reported symptom assessment among children and adolescents with high-risk malignancies is feasible using SSPedi. These patients experience a high burden of bothersome symptoms.