bluuebunny/crossref_metadata_2025_split huggingface dataset:
Visualization of an Oscillating Heat Pipe with Hydraulic Diameter Far Exceeding the Conventional Maximum Hydraulic Diameter
Authors: Ji Yulong , Chu Lilin , Yu Chunrong , Wang Zongyu , Ma Hongbin 
Published: February 2020

Abstract
For an oscillating heat pipe (OHP), the hydraulic diameter must be sufficiently small so that vapor plug and liquid slug can be formed by the capillary action. Therefore, the hydraulic diameter should not exceed a critical value named maximum hydraulic diameter (MHD). In the current research, a glass OHP with a hydraulic diameter of 6 mm was fabricated, and ethanol was used as the working fluid (Figs. 1 and 2). With a hydraulic diameter far exceeding the maximum hydraulic diameter (MHD) defined by dh,max≤{2σBo[(ρl−ρv)g]}1/2, the OHP can function. But the flow pattern is very different from that with a diameter smaller than the MHD, and depends on the filling ratio. When the OHP is charged with a higher filling ratio, the flow pattern is from the bubbly flow to the slug flow as shown in Fig, 3. When the charging ratio is low, the dispersed bubbly flow with many small bubbles generated on the surface was observed, and the dispersed bubbly flow was directly transformed into the annular flow as shown in Fig. 4. [This research work was supported by National Natural Science Foundation of China under Grant No. 51876019, the Preresearch of General Armament Department (6140922011310), LiaoNing Revitalization Talents Program (XLYC1807117), and the Fundamental Research Funds for the Central Universities of China under Grant No.3132019331.]
Laser Doppler Velocimetry Characterization of Unsteady Vaned Diffuser Flow in a Centrifugal Compressor
Authors: Gooding William J. , Fabian John C. , Key Nicole L. 
Published: February 2020

Abstract
Modern turbomachinery faces increased performance demands in terms of efficiency, compactness, and pressure-rise. Advancements in computational technology have allowed numerical methods to become the backbone of design development efforts. However, the unique complexities of centrifugal compressor flow-fields pose difficult computational problems. As such, advanced experimental methods must be used to obtain high-quality data sets to further inform, improve, and validate computational methods in complex flow regimes. A recent experimental work on a high-speed centrifugal compressor has provided detailed, unsteady, three-component velocity data using laser Doppler velocimetry. A passage vortex is present, and its nascent tied to the increased incidence at mid-span associated with impeller wake flow. This vortex begins in the hub-pressure side corner and grows to fill the passage and become temporally stable. The vortex development is unsteady in nature, and the unsteady effects persist 40% downstream of the throat. Distinct jet and wake flow patterns from the impeller also do not agglomerate until 40% downstream of the throat. Additionally, the critical impact of the unsteady flow development on the time-averaged flow-field is explained.
Multipoint optimization of an axial turbine cascade using a hybrid algorithm
Authors: Châtel Arnaud , Verstraete Tom , Coussement Grégory 
Published: February 2020

Abstract
This paper presents a multipoint optimization of the LS89 cascade. The objective of the optimization consists in minimizing the entropy losses generated inside the cascade over a predefined operating range. Two aerodynamic constraints are imposed in order to conserve the same performance as the original cascade. The first constraint is established on the outlet flow angle in order to achieve at least the same flow turning as the LS89. The second constraint limits the mass-flow passing through the cascade. The optimization is performed using a hybrid algorithm which combines a classical evolutionary algorithm with a gradient-based method. The hybridization between both methods is based on the Lamarckian approach which consists in incorporating the gradient method inside the loop of the evolutionary algorithm. In this methodology, the evolutionary method allows to globally explore the design space while the gradient-based method locally improves certain designs located in promising regions of the search space. First, the better performance of the hybrid method compared to the performance of an evolutionary algorithm is demonstrated on benchmark problems. Then, the methodology is applied on the LS89 application. The optimization allows to find a new profile which reduces the entropy losses over the entire operating range by at least 9.5 %. Finally, the comparison of the flows computed in the baseline and in the optimized cascades demonstrates that the reduction of the losses is due to a decrease of the entropy generated downstream the trailing edges and within the passages between the optimized blades.
Collaborative Robotics: A Survey
Authors: Vicentini Federico 
Published: February 2020

AbstractCollaborative robotics is an umbrella term that conveys the general idea of proximity between machines and humans for some useful tasks in a shared space, with a range of options for timing (continuously, synchronously, alternately, etc.). While this type of human robot interaction is fairly common in many fields of robotics, this survey is dedicated to the technology and situations that are typical of industrial applications. The current state-of-the-art in collaborative robotics for industrial applications is the result of a long legacy of research and development in actuation principles and mechanisms from 2000s onward, together with an abundant literature about improving control performances, intuitive interaction modes, and perception with sensors. Safety technology and standardization is discussed according to the principles of risk estimation and the typical strategies for risk reduction that are suitable for different classes of robot systems are used in collaborative applications. The organization of applications (planning, role assignment, optimization of resources) has a major impact on both the quality and the safety of collaborative robotics solutions, with most of the literature focused on investigating those performance metrics that combine human factors and production figures. The survey is intended to delineate an interpretation key for the design of collaborative robotics solution that explains the relationship among all relevant factors: actuation, control, safety, physical interaction, usability, and productivity.
Dynamic Modeling of the Cable-Driven Continuum Robots in Hybrid Position-Force Actuation Mode
Authors: Ehsani-Seresht Abbas , Hashemi-Pour Moosavi Shahin 
Published: February 2020

Abstract
Dynamic models of the cable-driven continuum robots are commonly employed for those robots that are actuated by the cables’ forces. In this paper, a dynamic model is proposed for the cable-driven continuum robots actuated by position and/or force actuated cables, which is appropriate for any desired number of actuation cables and their routing. The robot is supposed to have an extensible backbone with the capability of bending and torsion in three-dimensional spaces. The proposed dynamic model is developed based on the Euler–Lagrange formulation of equations of motion taking into account all the effective forces including gravity force, cable actuation forces, external forces, and cable-disk friction forces. Furthermore, an iterative numerical solution method is presented for the dynamic model which requires much less memory and computational effort in comparison with the closed-form methods. The static model of the robots is also developed based on the dynamic model and the results obtained from the simulations and experiments are used for the validation of the static and dynamic models. The final results indicate the accuracy of the proposed models for estimating the kinematics, statics, and dynamics of the cable-driven continuum robots.
Transcranial Direct Current Stimulation: No Effect on Aerobic Performance, Heart Rate, or Rating of Perceived Exertion in a Progressive Taekwondo-Specific Test
Authors: Mesquita Paulo H.C. , Franchini Emerson , Romano-Silva Marco A. , Lage Guilherme M. , Albuquerque Maicon R. 
Published: February 2020

Purpose: To investigate the effects of anodal transcranial direct current stimulation (a-tDCS) on the aerobic performance, heart rate (HR), and rating of perceived exertion (RPE) of highly trained taekwondo athletes. Methods: Twelve (8 men and 4 women) international/national-level athletes received a-tDCS or sham treatment over the M1 location in a randomized, single-blind crossover design. The stimulation was delivered at 1.5 mA for 15 min using an extracephalic bihemispheric montage. Athletes performed the progressive-specific taekwondo test 10 min after stimulation. HR was monitored continuously during the test, and RPE was registered at the end of each stage and at test cessation. Results: There were no significant differences between sham and a-tDCS in time to exhaustion (14.6 and 14.9, respectively, P = .53, effect size = 0.15) and peak kicking frequency (52 and 53.6, respectively, P = .53, effect size = 0.15) or in HR (P > .05) and RPE responses (P > .05). Conclusions: Extracephalic bihemispheric a-tDCS over M1 did not influence the aerobic performance of taekwondo athletes or their psychophysiological responses, so athletes and staff should be cautious when using it in a direct-to-consumer manner.
Enrichment of chalcophile elements in seawater accompanying the end-Cretaceous impact event
Authors: Maruoka Teruyuki , Nishio Yoshiro , Kogiso Tetsu , Suzuki Katsuhiko , Osawa Takahito , Hatsukawa Yuichi , Terada Yasuko 
Published: February 2020

AbstractChalcophile elements are enriched in the Cretaceous–Paleogene (KPg) boundary clays from Stevns Klint, Denmark. As the concentrations of Cu, Ag, and Pb among several chalcophile elements such as Cu, Zn, Ga, As, Ag, and Pb are correlated with those of Ir, we suggest that these elements were supplied to the oceans by processes related to the end-Cretaceous asteroid impact. Synchrotron X-ray fluorescence images revealed that Cu and Ag exist as trace elements in pyrite grains or as 1–10-µm-sized discrete phases specifically enriched in Cu or Ag. The difference in carrier phases might depend on the materials that transported these elements to the seafloor. Based on their affinities with Cu, Ag, and Ir, iron oxides/hydroxides and organic matter were identified as the potential carrier phases that supplied these elements to the seafloor. Chalcophile elements adsorbed on iron oxides/hydroxides might have been released during reductive dissolution of iron oxides/hydroxides and incorporated into the pyrite produced simultaneously with the reductive dissolution of iron oxides/hydroxides. Both iron oxides/hydroxides and chalcophile elements were possibly released from the KPg target rocks (i.e., sedimentary rocks and/or basement crystalline rocks) by impact heating.Elements with a high affinity to organic matter would have been released upon its degradation and then converted into discrete minerals because of the deficiency in Fe ions. As such discrete minerals include the elements that form acid soluble sulfides such as Cu, Ag, and Pb, enrichment of these elements might have been induced by the intense acid rain just after the end-Cretaceous asteroid impact.
Evidence of wildfires and elevated atmospheric oxygen at the Frasnian–Famennian boundary in New York (USA): Implications for the Late Devonian mass extinction
Authors: Liu Zeyang , Selby David , Hackley Paul C. , Over D. Jeffrey 
Published: February 2020

Abstract
The Devonian Period experienced significant fluctuations of atmospheric oxygen (O2) levels (∼25–13%), for which the extent and timing are debated. Also characteristic of the Devonian Period, at the Frasnian–Famennian (F–F) boundary, is one of the “big five” mass extinction events of the Phanerozoic. Fossilized charcoal (inertinite) provides a record of wildfire events, which in turn can provide insight into the evolution of terrestrial ecosystems and the atmospheric composition. Here, we report organic petrology, programmed pyrolysis analysis, major and trace element analyses, and initial osmium isotope (Osi) stratigraphy from five sections of Upper Devonian (F–F interval) from western New York, USA. These data are discussed to infer evidence of a wildfire event at the F–F boundary. Based on the evidence for a wildfire at the F–F boundary we also provide an estimate of atmospheric O2 levels of ∼23–25% at this interval, which is in agreement with the models that predict elevated pO2 levels during the Late Devonian. This, coupled with our Os isotope records, support the currently published Osi data that lacks any evidence for an extra-terrestrial impact or volcanic event at the F–F interval, and therefore to act as a trigger for the F–F mass extinction. The elevated O2 level at the F–F interval inferred from this study supports the hypothesis that pCO2 drawdown and associated climate cooling may have acted as a driving mechanism of the F–F mass extinction.
Effects of plaque brachytherapy and proton beam radiotherapy on prognostic testing: a comparison of uveal melanoma genotyped by microsatellite analysis
Authors: Thornton Sophie , Coupland Sarah E , Heimann Heinrich , Hussain Rumana , Groenewald Carl , Kacperek Andrzej , Damato Bertil , Taktak Azzam , Eleuteri Antonio , Kalirai Helen 
Published: February 2020

Background/aimsProton beam radiotherapy and plaque brachytherapy are commonly applied in primary uveal melanoma (UM); however, their effect on chromosome 3 classification of UM by microsatellite analysis (MSA) for prognostication purposes is unknown, where the tumour is sampled post-irradiation. This study examined the prognostic accuracy of genotyping UM biopsied before or after administration of radiotherapy, by MSA.Methods407 UM patients treated at the Liverpool Ocular Oncology Centre between January 2011 to December 2017, were genotyped for chromosome 3 by MSA; 172 and 176 primary UM were sampled prior to and post irradiation, respectively.ResultsGenotyping by MSA was successful in 396/407 (97%) of UM samples (196 males, 211 females; median age of 61 years (range 12 to 93) at primary treatment). There was no demonstrable association between a failure of MSA to produce a chromosome 3 classification and whether radiation was performed pre-biopsy or post-biopsy with an OR of 0.96 (95% CI 0.30 to 3.00, p=0.94). There was no evidence of association (measured as HRs) between risk of metastatic death and sampling of a primary UM before administration of radiotherapy (HR 1.1 (0.49 to 2.50), p=0.81). Monosomy 3 (HR 12.0 (4.1 to 35.0), p<0.001) was significantly associated with increased risk of metastatic death.Conclusions and relevanceThis study revealed that successful genotyping of UM using MSA is possible, irrespective of irradiation status. Moreover, we found no evidence that biopsy prior to radiotherapy increases metastatic mortality.
One small step for man, one giant leap for men’s health: a meta-analysis of behaviour change interventions to increase men’s physical activity
Authors: Sharp Paul , Spence John C , Bottorff Joan L , Oliffe John L , Hunt Kate , Vis-Dunbar Mathew , Caperchione Cristina M 
Published: February 2020

Objective
To determine the effects of behaviour change interventions on men’s physical activity (postintervention), sustained change in physical activity behaviour (≥12 months postintervention) and to identify variations in effects due to potential moderating variables (eg, theoretical underpinning, gender-tailored, contact frequency).

Design

Systematic review with meta-analysis. Pooled effect size (Cohen’s
d
) was calculated assuming a random-effects model. Homogeneity and subsequent exploratory moderator analyses were assessed using Q, T
2
and I
2
.

Data sources
Medline, EMBASE, CINAHL, SportDiscus and Web of Science to April 2019.

Eligibility criteria for selected studies
Randomised control trials of behaviour change interventions in men (≥18 years) where physical activity was an outcome and data were from men-only studies or disaggregated by sex.

Results
Twenty-six articles described 24 eligible studies. The overall mean intervention effect on men’s physical activity was 0.35 (SE=0.05; 95% CI 0.26 to 0.45; p<0.001). This effect size is consistent with an increase of approximately 97 min of total physical activity per week or 980 steps per day. Intervention moderators associated with greater increases in physical activity included objective physical activity outcome measures, a gender-tailored design, use of a theoretical framework, shorter length programmes (≤12 weeks), using four or more types of behaviour change techniques and frequent contact with participants (≥1 contact per week). 12 studies included additional follow-up assessments (≥12 months postintervention) and the overall mean effect was 0.32 (SE=0.09; 95% CI 0.15 to 0.48; p<0.001) for that sustained increase in physical activity.

Summary
Behaviour change interventions targeting men’s physical activity can be effective. Moderator analyses are preliminary and suggest research directions.
Association between financial links to indoor tanning industry and conclusions of published studies on indoor tanning: systematic review
Authors: Adekunle Lola , Chen Rebecca , Morrison Lily , Halley Meghan , Eng Victor , Hendlin Yogi , Wehner Mackenzie R , Chren Mary-Margaret , Linos Eleni 
Published: February 2020

AbstractObjectiveTo assess whether an association exists between financial links to the indoor tanning industry and conclusions of indoor tanning literature.DesignSystematic review.Data sourcesPubMed, Embase, and Web of Science, up to 15 February 2019.Study selection criteriaArticles discussing indoor tanning and health were eligible for inclusion, with no article type restrictions (original research, systematic reviews, review articles, case reports, editorials, commentaries, and letters were all eligible). Basic science studies, articles describing only indoor tanning prevalence, non-English articles, and articles without full text available were excluded.Results691 articles were included in analysis, including empiric articles (eg, original articles or systematic reviews) (357/691; 51.7%) and non-empiric articles letters (eg, commentaries, letters, or editorials) (334/691; 48.3%). Overall, 7.2% (50/691) of articles had financial links to the indoor tanning industry; 10.7% (74/691) articles favored indoor tanning, 3.9% (27/691) were neutral, and 85.4% (590/691) were critical of indoor tanning. Among the articles without industry funding, 4.4% (27/620) favored indoor tanning, 3.5% (22/620) were neutral, and 92.1% (571/620) were critical of indoor tanning. Among the articles with financial links to the indoor tanning industry, 78% (39/50) favored indoor tanning, 10% (5/50) were neutral, and 12% (6/50) were critical of indoor tanning. Support from the indoor tanning industry was significantly associated with favoring indoor tanning (risk ratio 14.3, 95% confidence interval 10.0 to 20.4).ConclusionsAlthough most articles in the indoor tanning literature are independent of industry funding, articles with financial links to the indoor tanning industry are more likely to favor indoor tanning. Public health practitioners and researchers need to be aware of and account for industry funding when interpreting the evidence related to indoor tanning.Systematic review registrationPROSPERO CRD42019123617.
Process evaluation of the central chronic medicines dispensing and distribution programme in Namakwa district, Northern Cape province protocol: a multimethod approach
Authors: Smith Kim Grace , Nicol Edward 
Published: February 2020

IntroductionThe quadruple burden of disease in South Africa, including the HIV/AIDS epidemic, has placed enormous strains on public healthcare (PHC) facilities. These strains specifically compromised the resources available to deal with high volumes of chronic diseases that contribute to medicine shortages and poor service delivery. In an attempt to address these challenges, the Central Chronic Medicines Dispensing and Distribution (CCMDD) programme, which aimed to provide public sector patients with alternative access to vital antiretroviral and other chronic medication, was implemented. This paper describes the protocol for a process evaluation of the programme compliance at the facility level in Namakwa district, to assess patient experiences and staff expectations of the programme; as well as, identifying factors that may affect the programme implementation so that guidance can be given on which approach to take to achieve programme objectives.Methods and analysisA multimethod approach will be used in a cross-sectional process evaluation of the CCMDD programme at 11 PHC facilities in Namakwa district. These methods will use checklists to assess programme compliance and subsequently gain an understanding of whether the programme was implemented as planned. Structured questionnaires together with focus group discussions will be conducted with selected patients enrolled in the programme and facility staff to determine patient experiences with and staff expectations of the programme, respectively. Furthermore, in-depth interviews will be conducted with key actors to explore barriers and facilitators of the programme implementation. Descriptive statistics will be conducted to analyse the quantitative data and an inductive interpretive approach will be used to analyse the qualitative data.Ethics and disseminationThe protocol was approved by Stellenbosch University Health Research Ethics Committee (S19/02/047) and the study will be conducted in line with the principles of the Declaration of Helsinki (1964). Findings from the study will be communicated to the study population, and at appropriate local and international conferences, in addition to publishing in peer-reviewed journals.