bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural Frequency Veering Patterns of Planetary Gears Under Design Parameter Variation
Authors: Lin Jian , Parker Robert G. 
Published: December 2020

Abstract
Noise and vibration reduction is a critical concern in planetary gear applications. During the design process, system parameters are varied to evaluate alternative design choices, avoid resonances, optimize load distribution, and reduce weight. It is important to characterize the effects of parameter variations on the natural frequencies and vibration modes for effective vibration tuning. In planetary gear dynamic models (Figure 1), the key design parameters include the mesh stiffness, support/bearing stiffness, component mass, and moment of inertia. Some plots of natural frequencies versus planetary gear parameters are presented by Cunliffe et al. (1974), Botman (1976), Kahraman (1994), and Saada and Velex (1995). Lin and Parker (1999a) analytically characterized the unique, highly-structured properties of planetary gear natural frequency spectra and vibration modes. They also derived simple, closed-form expressions for the sensitivities of natural frequencies and vibration modes to these parameters (Lin and Parker, 1999b). The natural frequency plots in the above literature show natural frequency veering phenomena where two eigenvalue loci approach each other as a parameter is varied but then abruptly veer away like two similar charges repelling (Figure 2a). The phenomenon has been extensively studied (Leissa, 1974; Perkins and Mote, 1986; Pierre, 1988; Chen and Ginsberg, 1992; Happawana et al., 1998). The vibration modes of the veering eigenvalues are strongly coupled and undergo dramatic changes in the veering neighborhood. Eigenvalue veering is also related to mode localization that can occur when disorder is introduced into nominally symmetric systems like turbine blades, space antennae, multi-span beams and other structures (Pierre, 1988). In the case of especially sharp veering, it is sometimes difficult to distinguish between intersection and veering just by observing eigenvalue plots. Curve veering/crossing complexity obstructs the tracing of eigenvalue loci under parameter changes. Also, when multiple curves veer or intersect close together (Figure 3), strong modal coupling (and associated operating condition response changes) occurs that is not identifiable from frequency loci plots. The objective of this work is to analytically characterize the rules of eigenvalue veering in planetary gear vibration. The special veering patterns derived here help to trace natural frequencies and examine impacts of design parameters on vibration. These veering patterns, combined with the unique modal properties (Lin and Parker, 1999a) and the eigensensitivies analysis (Lin and Parker, 1999b), provide designers considerable insight into planetary gear free vibration.
Analyzing Transmission Rattle: Object-Oriented Simulating and Testing the Dynamic Interaction Among Driveline Components
Authors: Bellomo Pietro , De Vito Nicola , Lang Claus-Hermann 
Published: December 2020

Abstract
In the global market of the 21st century the time-to-market reduction is an imperative statement for every automotive company. Automobile manufacturers must continue their efforts in order to exceed the customers’ expectations for improved quality during the engineering phase of new vehicles. Two available technological methods to meet that goal are simulation and bench testing. These enable advanced engineering and testing departments of the automotive industry to reduce development time and costs, identify weak spots of components or systems before volume parts are ever produced.
This paper presents an integrated approach described as object-oriented simulation and testing for vehicle driveline vibrations. It is also aimed to investigate transmission rattle, which is a well-known classical noise-vibration-harshness (NVH) phenomenon. It affects the vehicle ride and comfort resulting in customer satisfaction. The target of this combined analysis, simulation and testing, is to investigate the dynamic interaction of all driveline components by exciting them with the angular speed irregularities of a 4-cylinder diesel engine.
A new benefit with this approach is the ability for fine-tuning of the vehicle driveline. They also contribute to reduction of the time-to-market bottleneck during design and the development process. Also highlighting new methods to particularly research the transmission rattle phenomenon.
The application of the previously mentioned tools in a real vehicle rattling case is presented to show the potential of this approach.
Tooth Undercutting of Beveloid Gears
Authors: Liu Chia-Chang , Tsay Chung-Biau 
Published: December 2020

Abstract
A beveloid gear can be viewed as an involute gear of which the profile-shifted coefficient linearly decreases from the heel to the toe. Therefore, tooth undercutting occurs and singular points appear on the tooth surfaces near the toe. When undercutting occurs, the gear tooth is comparatively weak. In this study, the conditions of tooth undercutting of beveloid gears were derived and specific phenomena were also investigated by numerical illustrated examples. In addition, according to the characteristics of tooth undercutting on the beveloid gear tooth surface, a novel type hob cutter with varying cutting depths was designed to avoid tooth undercutting of the beveloid gear.
Vibration Characteristics and Surface Durability of Non-Involute Helical Gears
Authors: Nagamura Kazuteru , Ikejo Kiyotaka 
Published: December 2020

Abstract
This paper describes two non-involute helical gears that have involute-cycloid composite tooth profile and modified cycloid tooth profile. We designed and made involute-cycloid composite tooth profile helical gear and modified cycloid tooth profile helical gear to obtain high performance. Using these non-involute helical gears, the circumferential vibration acceleration of the helical gears, the tooth root stress, and the transmission error were measured on the running test. The experimental results showed that the vibration characteristics of the non-involute helical gears do not differ from that of the involute helical gear. Furthermore, we proved that the surface durability of the non-involute helical gears is superior to that of the involute helical gear from pitting test results.
Mixed Mode Fatigue Fracture Criteria for the Plates With an Inclined Semi-Elliptical Crack
Authors: Bian Lichun , Soh Ai Kah 
Published: December 2020

Abstract
The behaviour of fatigue crack propagation of rectangular steel plates, each consisting of an inclined semi-elliptical crack, subjected to axial loading was investigated both experimentally and theoretically. The inclined angle of the crack with respect to the axis of loading varied between 0° and 90°. In the present investigation, the Von Mises yield criterion was applied to define the core region, instead of a core region with a constant distance r from the crack tip. Based on Von Mises elasto-plastic boundary, the two commonly used fracture criteria, the maximum tensile stress and the minimum strain energy density criteria, were modified. The results obtained using the two improved fracture criteria were compared with those obtained using the commonly used mixed mode fracture criteria and experimental results. A mixed mode fatigue crack criterion has been established based on the experimental data.
Elasto-Plastic Behavior of Thermoplastic Matrix Roller Chain Link Plates Reinforced With Steel Fibers
Authors: Arslan Nurettin , Sancaktar Erol , Celik Mehmet 
Published: December 2020

Abstract
The elastic and elasto-plastic stress analysis of thermoplastic matrix roller chain link plates reinforced with steel fibers is performed by using Finite Elements Analysis (FEA). A two-dimensional finite element computer program is developed for elasto-plastic stress analysis. Isoparametric quadratic element with four nodes is used with Lagrange polynomial as an interpolation function. The results of elastic and elasto-plastic finite element stress analysis by using the computer program prepared, are compared with experimental, (photoelastic) results. The spreads of the plastic zones due to the external load applied on the pin-hole of the plate and variations of the residual stresses are determined in different orientation angles and loads. It is shown that the geometry of the link plates can be designed to decrease the stress concentrations. Furthermore, it is shown that the tensile load limit of the roller chain link plate is extended by the residual stresses.
Leisure Sedentary Behavior Levels and Meeting Program Goals in a Community Lifestyle Intervention for Diabetes Prevention
Authors: Rockette-Wagner Bonny , Miller Rachel G. , Eaglehouse Yvonne L. , Arena Vincent C. , Kramer M. Kaye , Kriska Andrea M. 
Published: December 2020

Background: The importance of leisure sedentary behavior (LSB) change in diabetes prevention efforts is not well known. This study examines the relationships between changes in self-reported LSB and the primary intervention goals (weight and moderate-intensity to vigorous-intensity physical activity [MVPA]) during a community-based translation of the Diabetes Prevention Program (the Group Lifestyle Balance Program). Methods: A total of 322 adults at risk for type 2 diabetes were recruited from 3 community centers, a worksite, and military site. Community and worksite participants were randomized to immediate or delayed-delivery (control) intervention. All military site participants (n = 99) received immediate intervention. Logistic and linear generalized estimating equations were used to determine associations between LSB changes and weight-related outcomes and MVPA. Results: Results were obtained for 259 (80.4%) participants. The LSB decreased after 6 and 12 months (mean [95% confidence interval]: −25.7 [−38.6 to −12.8] and −16.1 [−28.2 to −3.9] min/d; both P < .05). Each 20-minute reduction in LSB was associated with a 5% increase in odds of meeting the weight-loss goal (6 mo: odds ratio = 1.05 [1.002 to 1.102]; P = .042; adjusted model including MVPA), but LSB was not related to changes in reported MVPA minutes or MVPA goal achievement. Conclusion: Within the context of existing lifestyle intervention programs, reducing sedentary behavior has the potential to contribute to weight loss separately from reported MVPA improvement.
Injury patterns differ with age in male youth football: a four-season prospective study of 1111 time-loss injuries in an elite national academy
Authors: Wik Eirik Halvorsen , Lolli Lorenzo , Chamari Karim , Materne Olivier , Di Salvo Valter , Gregson Warren , Bahr Roald 
Published: December 2020

ObjectivesTo describe age group patterns for injury incidence, severity and burden in elite male youth football.MethodsProspective cohort study capturing data on individual exposure and time-loss injuries from training and matches over four seasons (2016/2017 through 2019/2020) at a national football academy (U13–U18; age range: 11–18 years). Injury incidence was calculated as the number of injuries per 1000 hours, injury severity as the median number of days lost and injury burden as the number of days lost per 1000 hours.ResultsWe included 301 players (591 player-seasons) and recorded 1111 time-loss injuries. Overall incidence was 12.0 per 1000 hours (95% CI 11.3 to 12.7) and burden was 255 days lost per 1000 hours (252 to 259). The mean incidence for overall injuries was higher in the older age groups (7.8 to 18.6 injuries per 1000 hours), while the greatest burden was observed in the U16 age group (425 days; 415 to 435). In older age groups, incidence and burden were higher for muscle injuries and lower for physis injuries. Incidence of joint sprains and bone stress injuries was greatest for players in the U16, U17 and U18 age groups, with the largest burden observed for U16 players. No clear age group trend was observed for fractures.ConclusionInjury patterns differed with age; tailoring prevention programmes may be possible.
(Not) talking about fertility: the role of digital technologies and health services in helping plan pregnancy. A qualitative study
Authors: French Rebecca S , Shawe Jill , Tilouche Nerissa , Earle Sarah , Grenfell Pippa 
Published: December 2020

AimTo explore how women and their partners navigate (pre)conception healthcare and the role of Natural Cycles fertility awareness technology in this process.MethodsIn-depth interviews with 24 cisgender women aged 24–43 years who had used Natural Cycles’ ‘Plan a Pregnancy’ mode, and six partners of Natural Cycles users, all cisgender men aged 30–39 years. Participants were recruited via direct messaging in the Natural Cycles app, social media and, for partners, snowball sampling. Purposive sampling was conducted to ensure diversity among participants. Interviews were audio-recorded and transcribed verbatim. An iterative, inductive approach was adopted for thematic data analysis.ResultsNatural Cycles helped most users better understand their menstrual cycles and fertility. Fertility awareness and preconception counselling with healthcare providers were uncommon. Women felt discussions about planning pregnancy in healthcare settings were often fraught with difficulties. They described not wanting to be an extra burden to overworked staff, being concerned that their worries about trying for pregnancy would be dismissed, or feeling staff did not have expertise in fertility awareness. Some women had shared their Natural Cycles data with healthcare professionals to demonstrate their menstrual cycle data or time of conception. However, it was not always clear to those not accessing services when they should seek further advice, for example, those using the app for longer time periods who had not yet conceived.ConclusionsDigital technologies can provide information and support for those wanting to conceive. They should, however, complement care in statutory services, and be accompanied by greater investment in fertility awareness and preconception support.
Young-onset colorectal cancer risk among individuals with iron-deficiency anaemia and haematochezia
Authors: Demb Joshua , Liu Lin , Murphy Caitlin C. , Doubeni Chyke A. , Martínez María Elena , Gupta Samir 
Published: December 2020

ObjectiveYoung-onset colorectal cancer (YCRC) incidence is rising. Scant data exist on YCRC risk after presentation with concerning symptoms such as iron-deficiency anaemia (IDA) or haematochezia. We examined the association between IDA and YCRC, and haematochezia and YCRC.DesignCohort study of US Veterans aged 18–49 years receiving Veterans Health Administration (VHA) care 1999–2016. IDA analytic cohort was created matching individuals without incident IDA to those with IDA 4:1 based on sex, birth year and first VHA visit date (n=239 000). We used this approach to also create a distinct haematochezia analytic cohort (n=653 740). Incident YCRC was ascertained via linkage to cancer registry and/or cause-specific mortality data. We computed cumulative incidence, risk difference (RD) and HRs using Cox models in each cohort.ResultsFive-year YCRC cumulative incidence was 0.45% among individuals with IDA versus 0.05% without IDA (RD: 0.39%, 95% CI: 0.33%–0.46%), corresponding to an HR of 10.81 (95% CI: 8.15–14.33). Comparing IDA versus no IDA, RD was 0.78% for men (95% CI: 0.64%–0.92%) and 0.08% for women (95% CI: 0.03%–0.13%), and RD increased by age from 0.14% for <30 years to 0.53% for 40–49 years. YCRC cumulative incidence was 0.33% among individuals with haematochezia versus 0.03% without haematochezia (RD: 0.30%, 95% CI: 0.26%–0.33%), corresponding to an HR of 10.66 (95% CI: 8.76–12.97). Comparing haematochezia versus no haematochezia, RD increased by age from 0.04% for <30 years to 0.43% for 40–49 years.ConclusionColonoscopy should be strongly considered in adults aged <50 years with IDA or haematochezia without a clinically confirmed alternate source.
Revisiting heart failure assessment based on objective measures in NYHA functional classes I and II
Authors: Blacher Mariana , Zimerman André , Engster Pedro H B , Grespan Eduardo , Polanczyk Carisi A , Rover Marciane M , Neto José A de Figueiredo , Danzmann Luiz C , Bertoldi Eduardo G , Simões Marcus Vinicius , Beck-da-Silva Luis , Biolo Andréia , Rohde Luis E 
Published: December 2020

ObjectiveNew York Heart Association (NYHA) functional class plays a central role in heart failure (HF) assessment but might be unreliable in mild presentations. We compared objective measures of HF functional evaluation between patients classified as NYHA I and II in the Rede Brasileira de Estudos em Insuficiência Cardíaca (ReBIC)-1 Trial.MethodsThe ReBIC-1 Trial included outpatients with stable HF with reduced ejection fraction. All patients had simultaneous protocol-defined assessment of NYHA class, 6 min walk test (6MWT), N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and patient’s self-perception of dyspnoea using a Visual Analogue Scale (VAS, range 0–100).ResultsOf 188 included patients with HF, 122 (65%) were classified as NYHA I and 66 (35%) as NYHA II at baseline. Although NYHA class I patients had lower dyspnoea VAS Scores (median 16 (IQR, 4–30) for class I vs 27.5 (11–49) for class II, p=0.001), overlap between classes was substantial (density overlap=60%). A similar profile was observed for NT-proBNP levels (620 pg/mL (248–1333) vs 778 (421–1737), p=0.015; overlap=78%) and for 6MWT distance (400 m (330–466) vs 351 m (286–408), p=0.028; overlap=64%). Among NYHA class I patients, 19%–34% had one marker of HF severity (VAS Score >30 points, 6MWT <300 m or NT-proBNP levels >1000 pg/mL) and 6%–10% had two of them. Temporal change in functional class was not accompanied by variation on dyspnoea VAS (p=0.14).ConclusionsMost patients classified as NYHA classes I and II had similar self-perception of their limitation, objective physical capabilities and levels of natriuretic peptides. These results suggest the NYHA classification poorly discriminates patients with mild HF.
Initiation of immunotherapy with activated natural killer cells and anti-GD2 antibody dinutuximab prior to resection of primary neuroblastoma prolongs survival in mice
Authors: Zobel Michael John , Zamora Abigail K , Wu Hong-wei , Sun Jianping , Lascano Danny , Malvar Jemily , Wang Larry , Sheard Michael A , Seeger Robert C , Kim Eugene S 
Published: December 2020

BackgroundImmunotherapy with anti-disialoganglioside dinutuximab has improved survival for children with high-risk neuroblastoma (NB) when given after induction chemotherapy and surgery. However, disease recurrence and resistance persist. Dinutuximab efficacy has not been evaluated when initiated before primary tumor removal. Using a surgical mouse model of human NB, we examined if initiating dinutuximab plus ex vivo-activated natural killer (aNK) cells before resection of the primary tumor improves survival.MethodsIn vitro, human NB cells (SMS-KCNR-Fluc, CHLA-255-Fluc) were treated with dinutuximab and/or aNK cells and cytotoxicity was measured. In vivo, NB cells (SMS-KCNR-Fluc, CHLA-255-Fluc, or COG-N-415x PDX) were injected into the kidney of NOD-scid gamma mice. Mice received eight intravenous infusions of aNK cells plus dinutuximab beginning either 12 days before or 2 days after resection of primary tumors. Tumors in control mice were treated by resection alone or with immunotherapy alone. Disease was quantified by bioluminescent imaging and survival was monitored. aNK cell infiltration into primary tumors was quantified by flow cytometry and immunohistochemistry at varying timepoints.ResultsIn vitro, aNK cells and dinutuximab were more cytotoxic than either treatment alone. In vivo, treatment with aNK cells plus dinutuximab prior to resection of the primary tumor was most effective in limiting metastatic disease and prolonging survival. aNK cell infiltration into xenograft tumors was observed after 1 day and peaked at 5 days following injection.ConclusionDinutuximab plus aNK cell immunotherapy initiated before resection of primary tumors decreases disease burden and prolongs survival in an experimental mouse model of NB. These findings support the clinical investigation of this treatment strategy during induction therapy in patients with high-risk NB.
Factors impacting health and well-being and the utilisation of supports among Australian doctors in medical specialty training
Authors: Abhary Sotoodeh , Botti Mari , Dhulia Anjali , Tham Christopher , Loh Erwin , Catford John 
Published: December 2020

PurposeTo explore factors impacting the health and well-being of doctors undertaking various specialty training programs, and attitudes towards and utilisation of supports during their training. This is a subset of data from a larger study exploring experiences of doctors in Australian specialty training—a qualitative study of enablers, stressors and supports.MethodsIn this qualitative study, registrars in specialist training programmes in Australia were invited and interviewed between August 2015 and August 2016. Semistructured open-ended questions were used to explore topics of relevance to their workplace, training, support service utilisation and personal lives. Interviews were transcribed verbatim, deidentified and content and thematic analysis undertaken. Recruitment was ceased when data saturation was reached and no new themes emerged. Emerging key themes are reported in this studyResults17 participants were recruited (including 1 Indigenous and 1 international medical graduate). A total of six specialty training programmes, across multiple states at various locations across Australia, were represented.Common themes impacting health and well-being regarding workplace and training stressors were identified, including poor supervision, shiftwork and on-call, inability to take sick leave, bullying and harassment, college-related factors, examination preparation and work–life imbalance. Several of these were identified as having actual and perceived negative impacts on patient outcomes and safety.The majority of participants underused existing supports and were unaware of the breadth of support services available to them. Barriers to accessing these services included concerns about their confidentiality and career repercussions.ConclusionsThis first Australian pilot study highlighted many stressors and enablers in the workplace, training and personal lives of registrars. The underutilisation and barriers to access of support services were discovered. Several multisystem strategies are required and discussed in this report to address these complex issues identified as affecting the health and well-being of junior doctors.