bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of Additive Manufactured GRCop-42 Alloy Developed by Directed Energy Deposition Methods
Authors: Landes Scott , Suresh Trupti , Prasad Anamika , Letcher Todd , Gradl Paul , Ellis David 
Published: February 2021

Abstract
GRCop is an alloy family constructed of copper, chromium, and niobium and was developed by NASA for high heat flux applications. GRCop-alloys were specifically formulated for the requirements in channel-cooled main combustion chambers allowing for repeat use in high heat flux environments [1]. GRCop-84 was evolved using additive manufacturing techniques under a NASA development program. To further increase thermal conductivity while maintaining material strength characteristics, the percentage of alloying elements were cut in half and GRCop-42 was developed. In recent years, NASA has successfully additively manufactured GRCop-42 with comparable material characteristics to extruded GRCop-42 using a Laser Powder Bed Fusion (L-PBF) process. Benefits of this process include fabrication of intricate internal cooling channels as well as a decrease in manufacturing time. However, there are some large disadvantages in using this process. The nature of the powder bed process imposes a strict volume constraint as well as an excessive amount of material inventory required. A Directed Energy Deposition (DED) process addresses these limitations while also speeding up the manufacturing process. With little data on how DED performs with GRCop-42, an investigation into the mechanical properties was conducted. More specifically, Blown Powder Directed Energy Deposition (BPD), was used to compare material properties to that of the L-PBF manufactured GRCop-42. The DED manufactured material was found to have less than 0.1% porosity. Tensile tests concluded that the DED manufactured GRCop-42 had lower tensile strengths at room temperature. The results point towards a process capable of producing fully dense parts capable of meeting mechanical strength requirements with some possible refinement of printing parameters.
Degradation of the Strength of a Grain Boundary of Ni-Base Superalloys Under Creep-Fatigue Loading at Elevated Temperature
Authors: Takahashi Yukako , Luo Yifan , Ishihara Kenta , Suzuki Shujiro , Miura Hideo 
Published: February 2021

Abstract
The degradation of the strength of a grain boundary was measured by using a micro tensile test in a scanning electron microscope. The change of the crystallinity of grain boundaries during creep-fatigue tests of Ni-base alloy such as Alloy 617 and 625 at elevated temperatures was monitored by electron back-scatter diffraction analysis. The image quality (IQ) value obtained from the analysis, which indicates the total density of defects, was applied to the quantitative evaluation of the crystallinity. It was clearly observed that the accumulation of defects occurred at grain boundaries which were perpendicular to the loading direction and consisted of grains with large difference of Schmid factor. Bicrystal specimens with different crystallinity were cut from the tested samples and the strength of the bicrystal specimens were measured by using the micro tensile test system. It was confirmed that the strength of a grain boundary decreased monotonically by about 50% with the decrease of IQ value, in other words, the increase in the total density of various defects such as vacancies and dislocations. On the other hand, the effective yielding stress of grains increased monotonically with the decrease of the IQ value. This is because the increase in the total density of these defects suppresses the movement of dislocations, in other words, plastic deformation. Therefore, there were three independent strengths, the strength of two grains and that of a grain boundary which consisted of the bicrystal specimen. Since the strength of grains increased, at the same time, that of a grain boundary decreased monotonically with the decrease of the IQ value, it was confirmed that there was critical IQ value at which the fracture mode of a bicrystal specimen changed from conventional transgranular cracking to intergranular cracking under the application of uniaxial tensile load.
Light Assisted Hybrid Direct Write Additive Manufacturing of Thermosets
Authors: Alrashdan Abdulrahman , Wright William Jordan , Celik Emrah 
Published: February 2021

Abstract
In the past recent years, numerous studies have been conducted on additive manufacturing of thermosets and thermoset composites. Thermosets are an important class of polymers used in engineering applications. Monomer units in these material systems irreversibly cross-link when external stimuli or a chemical crosslinking agent is applied in terms of the curing or photopolymerization process. Thermally curing thermosets mark unique mechanical properties including, high temperature resistance, strong chemical bond, and structural integrity and therefore these materials find wide range of applications currently. However, direct write additive manufacturing of these material systems at high resolution and at complex geometries is challenging. This is due to the slow curing rate of thermally curing thermoset polymers which can adversely affect the printing process, and the final shape of the printed object. On the other hand, VAT Polymerization additive manufacturing, which is based on curing the photopolymer resin by Ultraviolet (UV) light, can allow the fabrication of complex geometries and excellent surface finish of the printed parts due to the fast curing rate of photopolymers used in this technique. Mechanical properties of photopolymers, however, are usually weaker and more unstable compared to the thermally curing polymers used in the direct write additive manufacturing method. Therefore, this study focuses on taking the advantages of these two thermoset additive manufacturing methods by utilizing both the thermally cured epoxy and photopolymer resins together. Using the direct writing, the resin mixture is extruded though a nozzle and the final 3D object is created on the print bed. Simultaneously, the deposited ink is exposed to the UV light enhancing the yield strength of the printed material and partially curing it. Therefore, thermally cured epoxy is used to obtain the desirable mechanical properties, while the addition of the photopolymer resin allows the thermoset mixture to partially solidify the printed ink when exposed to the UV light. The results achieved in this study showed that, the hybrid additive manufacturing technology is capable of fabricating complex and tall structure which cannot be printable via additive manufacturing method. In addition, mechanical properties of the hybrid thermoset ink are comparable to the thermally cured thermoset polymer indicating the great potential of the light-assisted, hybrid manufacturing to fabricate mechanically strong parts at high geometrical resolution.
A Comparison of Smoothed Particle Hydrodynamics (SPH) and Coupled SPH-FEM Methods for Modeling Machining
Authors: Ojal Nishant , Cherukuri Harish P. , Schmitz Tony L. , Jaycox Adam W. 
Published: February 2021

Abstract
Smoothed Particle Hydrodynamics (SPH), a particle-based, meshless method originally developed for modeling astrophysical problems, is being increasingly used for modeling fluid mechanics and solid mechanics problems. Due to its advantages over grid-based methods in the handling of large deformations and crack formation, the method is increasingly being applied to model material removal processes. However, SPH method is computationally expensive. One way to reduce the computational time is to partition the domain into two parts where, the SPH method is used in one segment undergoing large deformations and material separation and in the second segment, the conventional finite element (FE) mesh is used.
In this work, the accuracy of this SPH-FEM approach is investigated in the context of orthogonal cutting. The high deformation zone (where chips form and curl) is meshed with the SPH method, while the rest of the workpiece is modeled using the FE method. At the interface, SPH particles are coupled with FE mesh for smooth transfer of stress and displacement. The boundary conditions are applied to tool and FE zone of the workpiece. For comparison purposes, a fully-SPH model (workpiece fully discretized by SPH) is also developed. This is followed by a comparison of the results from the coupled SPH-FE model with the SPH model. A comparison of the chip profile, the cutting force, the von Mises stress and the damage parameter show that the coupled SPH-FE model reproduces the SPH model results accurately. However, the SPH-FE model takes almost 40% less time to run, a significant gain over the SPH model. Similar reduction in computation time is observed for in a micro-cutting application (depth of cut of 300 nm). Based on these results, it is concluded that coupling SPH with FEM in machining models decreases simulation time significantly while still producing accurate results. This observation suggests that three-dimensional machining problems can be modeled using the combined SPH-FEM approach without sacrificing accuracies.
Braking Safety Design and Analysis for Railway Vehicles
Authors: Fang Ziwen , Zhang Yanping , Zheng Caihui , Wang Xintian , Cheng Ming , Zhang Haifeng , Hong Haifeng 
Published: February 2021

Abstract
Brake is a safety critical system for railway vehicles and brake failures have caused many catastrophic accidents in the history. Detailed accident investigation reports are available and National Transportation Safety Board (NTSB) also makes safety recommendations to Federal Railroad Administration and the industry. However, there is limited research on how to improve the brake safety from the perspective of design, system integration and safety analysis. In this paper, a framework for braking safety design and analysis is introduced, which includes four parts: failure alarming system, safety design, safety analysis and preventative maintenance. For failure alarming, according to the severity level, the failures will be notified to the operator, to Operation Control Center (OCC) or saved for the maintainer. For safety design, redundant design for fail-safe feature, automatic braking, brake release, weight control, ergonomics design for easy operation and maintenance are discussed and several application examples are illustrated. In the safety analysis section, Preliminary Hazard Analysis (PHA) as a semi-quantitative analysis, Failure Modes, Effects, and Criticality Analysis (FMECA) as a bottom-up method and Fault Tree Analysis as a top-down method are used. The hazards details, system assurance actions and closure references are recorded in the Hazard Tracking Log (HTL) to ensure all the safety related items are well tracked and documented. Preventative Maintenance (PM) which is regularly performed on the brake components to lessen the likelihood of failing is also discussed in combination with the reliability prediction and safety analysis for a balance of safety and economy. The safety design framework and principles introduced in this paper can also be applied into other railway systems, such as Propulsion, Signaling, Doors, etc. and may provide insights to similar industries such as automotive, energy and so on.
“Keep Moving”: Experiences of People With Parkinson’s and Their Care Partners in a Dance Class
Authors: Prieto Laura , Norris Michael L. , Columna Luis 
Published: February 2021

The purpose of this study was to examine the experiences of people with Parkinson’s (PwP) and their care partners (CPs) who participated in a Parkinson’s-focused community dance class in a northeastern state of the United States. In this qualitative inquiry, participants included five PwP and their respective CPs (n = 5). Three major, recurrent, and interrelated themes emerged from the data. These themes were (a) keep moving, (b) compassion in action, and (c) acceptance and freedom in dance. These themes captured personal and environmental factors that influenced the participation of PwP and their CPs in a dance class and how they perceived that dance influenced their quality of life. The themes described the obstacles, motives, and perceived outcomes of participating in dance. The findings emphasize the need for future dance interventions and programs that consider the CPs’ role in promoting participation for PwP in dance classes.
Spousal concordance in pathophysiological markers and risk factors for type 2 diabetes: a cross-sectional analysis of The Maastricht Study
Authors: Silverman-Retana Omar , Brinkhues Stephanie , Hulman Adam , Stehouwer Coen D A , Dukers-Muijrers Nicole H T M , Simmons Rebecca K , Bosma Hans , Eussen Simone , Koster Annemarie , Dagnelie Pieter , Savelberg Hans H C M , Schaper Nicolaas C , van Dongen Martien C J M , Witte Daniel R , Schram Miranda T 
Published: February 2021

IntroductionWe compared the degree of spousal concordance in a set of detailed pathophysiological markers and risk factors for type 2 diabetes to understand where in the causal cascade spousal similarities are most relevant.Research design and methodsThis is a cross-sectional analysis of couples who participated in The Maastricht Study (n=172). We used quantile regression models to assess spousal concordance in risk factors for type 2 diabetes, including four adiposity measures, two dimensions of physical activity, sedentary time and two diet indicators. We additionally assessed beta cell function and insulin sensitivity and glucose metabolism status with fasting and 2-hour plasma glucose and hemoglobin A1c.ResultsThe strongest spousal concordance (beta estimates) was observed for the Dutch Healthy Diet Index (DHDI) in men. A one-unit increase in wives’ DHDI was associated with a 0.53 (95% CI 0.22 to 0.67) unit difference in men’s DHDI. In women, the strongest concordance was for the time spent in high-intensity physical activity (HPA); thus, a one-unit increase in husbands’ time spent in HPA was associated with a 0.36 (95% CI 0.17 to 0.64) unit difference in women’s time spent in HPA. The weakest spousal concordance was observed in beta cell function indices.ConclusionsSpousal concordance was strongest in behavioral risk factors. Concordance weakened when moving downstream in the causal cascade leading to type 2 diabetes. Public health prevention strategies to mitigate diabetes risk may benefit from targeting spousal similarities in health-related behaviors and diabetes risk factors to design innovative and potentially more effective couple-based interventions.
Short maternal stature and gestational weight gain among refugee and migrant women birthing appropriate for gestational age term newborns: a retrospective cohort on the Myanmar-Thailand border, 2004–2016
Authors: Lee Sue J , Hashmi Ahmar H , Min Aung Myat , Gilder Mary Ellen , Tun Nay Win , Wah Lay Lay , Wah Mu , Win Elsi , Ner Ma , Charunwatthana Prakaykaew , Nosten François H , Carrara Verena I , McGready Rose 
Published: February 2021

IntroductionTo examine the interactions between short maternal stature, body mass index (BMI) and gestational weight gain (GWG) among appropriate for gestational age (AGA) term newborns in a population of refugees and migrants in Southeast Asia.MethodsThis is a retrospective cohort study from 2004 to 2016, including women delivering term, singleton newborns, with first trimester height, weight and gestation dated by ultrasound and a last body weight measured within 4 weeks of birth. AGA newborns were those not classified as small for gestational age or large for gestational age by either INTERGROWTH-21st or Gestation Related Optimal Weight standards. The influence of maternal stature on GWG in delivering an AGA newborn was analysed, with GWG compared with existing National Academy of Medicine (NAM) recommendations.Results4340 women delivered AGA newborns. Mean maternal height (SD) was 151.5 cm (5.13), with 58.5% of women considered too short by INTERGROWTH-21st standards. Only one in four women (26.5%, 1150/4340) had GWG within NAM recommendations. Women of shorter stature had a significantly lower mean GWG compared with taller women in underweight and normal BMI categories (p<0.001 for both BMI categories). Mean GWG of overweight and obese women did not differ by height (p=1.0 and p=0.85, respectively) and fell within the lower range of NAM recommendations.ConclusionThese results suggest that short maternal stature can be an important predictor of GWG and should be considered with prepregnancy BMI. Limited-resource settings and special populations need robust GWG recommendations that reflect height and BMI.
Impact of team-based community healthcare on preventable hospitalisation: a population-based cohort study in Taiwan
Authors: Jan Chyi-Feng Jeff , Chang Che-Jui Jerry , Hwang Shinn-Jang , Chen Tzeng-Ji , Yang Hsiao-Yu , Chen Yu-Chun , Huang Cheng-Kuo , Chiu Tai-Yuan 
Published: February 2021

ObjectivesThe objective of this study was to explore the impact of Taiwan’s Family Practice Integrated Care Project (FPICP) on hospitalisation.DesignA population-based cohort study compared the hospitalisation rates for ambulatory care sensitive conditions (ACSCs) among FPICP participating and non-participating patients during 2011–2015.SettingThe study accessed the FPICP reimbursement database of Taiwan’s National Health Insurance (NHI) administration containing all NHI administration-selected patients for FPICP enrolment.ParticipantsThe NHI administration-selected candidates from 2011 to 2015 became FPICP participants if their primary care physicians joined the project, otherwise they became non-participants.InterventionsThe intervention of interest was enrolment in the FPICP or not. The follow-up time interval for calculating the rate of hospitalisation was the year in which the patient was selected for FPICP enrolment or not.Primary outcome measuresThe study’s primary outcome measures were hospitalisation rates for ACSC, including asthma/chronic obstructive pulmonary disease (COPD), diabetes or its complications and heart failure. Logistic regression was used to calculate the ORs concerning the influence of FPICP participation on the rate of hospitalisation for ACSC.ResultsThe enrolled population for data analysis was between 3.94 and 5.34 million from 2011 to 2015. Compared to non-participants, FPICP participants had lower hospitalisation for COPD/asthma (28.6‰–35.9‰ vs 37.9‰–42.3‰) and for diabetes or its complications (10.8‰–14.9‰ vs 12.7‰–18.1‰) but not for congestive heart failure. After adjusting for age, sex and level of comorbidities by logistic regression, participation in the FPICP was associated with lower hospitalisation for COPD/asthma (OR 0.91, 95% CI 0.87 to 0.94 in 2015) and for diabetes or its complications (OR 0.87, 95% CI 0.83 to 0.92 in 2015).ConclusionParticipation in the FPICP is an independent protective factor for preventable ACSC hospitalisation. Team-based community healthcare programs such as the FPICP can strengthen primary healthcare capacity.
Rationalisations for women-only randomised controlled trials in conditions that affect both sexes: a scoping review protocol
Authors: Matthewson Ainsley , Bereznyakova Olena , Dewar Brian , Davis Alexandra , Fedyk Mark , Yogendrakumar Vignan , Fergusson Dean A , Gocan Sophia , Dowlatshahi Dar , Fahed Robert , Shamy Michel 
Published: February 2021

IntroductionWomen have historically been under-represented in randomised controlled trials (RCTs), including many landmark RCTs that established standards of care. In light of this fact, some modern researchers are calling for replication of earlier landmark trials with women only. This approach is ethically concerning, in that it would require some enrolled women to be deprived of treatments that are currently considered standard of care.ObjectiveIn an attempt to better understand the justification of a women-only approach to designing clinical trials, this study looks to systematically categorise the number of women-only RCTs for conditions that affect both men and women and the reasons given within the medical and philosophical literatures to perform them.MethodologyThis scoping review of the literature will search, screen and select articles based on predetermined inclusion/exclusion criteria, after which a grounded theory approach will be used to synthesise the data. It is expected that there will be a variety of reasons given for why a women-only trial may be justified. Electronic databases that will be searched include MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Clinical Trials Register, Web of Science Proceedings, ClinicalTrials.gov, Philosopher’s Index, Phil Papers, JSTOR, Periodicals Archive Online, Project MUSE and the National Reference Centre for Bioethics.SignificanceThe scope of this study is to determine published rationales used to justify women-only randomised trials, both in the case of new trials and in the repetition of landmark trials.Ethics and disseminationResearch ethics board approval is not required for this study as there is no participant involvement. Results will be published as a stand-alone manuscript and will inform a larger project related to the ethics of a women-only RCT of carotid intervention for women with symptomatic high-grade carotid stenosis.
Epidemiology of chronic pain in children and adolescents: a protocol for a systematic review update
Authors: Tutelman Perri R , Langley Charlotte L , Chambers Christine T , Parker Jennifer A , Finley G Allen , Chapman Darlene , Jones Gareth T , Macfarlane Gary J , Marianayagam Justina 
Published: February 2021

IntroductionChronic pain, defined as persistent or recurring pain or pain lasting longer than 3 months, is a common childhood problem and can profoundly impact children’s physical, psychological and social functioning. The last comprehensive systematic review estimating the prevalence of chronic pain in children and adolescents was published in 2011. Since then, the literature on paediatric chronic pain has grown substantially. This manuscript outlines a protocol for an updated systematic review to provide updated estimates of the prevalence of various forms of chronic pain in children and adolescence. The review will also examine the relationship between sociodemographic and psychosocial factors related to chronic pain prevalence.Methods and analysisThis review will follow Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We will search EMBASE, PubMed, CINAHL and PsycINFO for observational studies published in English between 2009 and 2020 reporting population-based estimates of chronic non-disease-related pain prevalence in children or adolescents (age ≤19 years). Two independent reviewers will screen the titles and abstracts retrieved from the search based on predefined eligibility criteria. The full texts of relevant studies will then be assessed by two reviewers. Studies meeting inclusion criteria will be categorised according to the type of pain investigated: headache only, abdominal pain only, back pain only, musculoskeletal pain, combined pain, general pain and other pain. Data will be extracted using customised forms and studies will be assessed for risk of bias using a 10-item tool developed by Hoyet al(2012). A narrative synthesis will summarise the prevalence estimates of paediatric chronic pain and associated sociodemographic and psychosocial correlates. Meta-analyses and meta-regressions will be performed if the data permit.Ethics and disseminationEthical approval is not required. Findings will be disseminated through publication in an academic journal, presentations at conferences and in various media.PROSPERO registration numberCRD42020198690.