bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Composite Blade/Casing Rub Stability Through Delayed Differential Equations
Authors: Xiao Jiaguangyi , Chen Yong , Tian Jie , Ouyang Hua , Wang Anjenq 
Published: September 2019

Abstract
To improve aerodynamic efficiencies, the clearances between blades and casings are becoming smaller and smaller in the aero-engine industry, which might lead to the interactions between these components. These unexpected interactions are known as the so-called blade/casing rubs. Abradable materials are implemented on the inner surface of the casings to reduce the potential damages caused by it. However, failures may still arise from blade/casing rubs according to experimental investigations and actual accidents. In this paper, a reduced-order delayed differential equations (DDEs) are used to simplify the rubbing process between composite blade and casing. It is assumed that the removal of the abradable material in blade/casing rubbing process shares a resemblance with machine tool chatters encountered in machining. The DDEs are established with centrifugal stiffness and the impacts of stacking sequences on the blade damping taking into consideration. Semidiscretization method (SDM) is used to study the stabilities of the simplified system, which is verified by cluster treatment of characteristic roots (CTCR) and direct integrations. The results show that the stacking sequences, rub positions, blade damping, and stiffness could have much impact on the relatively dangerous interaction regimes. With the help of this method, one can assist the design processes of the composite blade-casing interface in initial aero-engine structural designs.
A Reduced-Order Model for Loosening of Bolted Joints Subjected to Axial Shock Excitation
Authors: Moore Keegan J. 
Published: September 2019

Abstract
Maintaining preload in bolted joints is critical for the safe and efficient operation of nearly all built-up structures. Dynamic loss of preload during operation occurs when sufficient shear force is applied to the joint such that slip is induced in at least the threads if not the entire bolt. Such shear forces are often realized when the joint is subjected to sustained vibrations, resulting in loosening over relatively long periods of time, or extreme shock loading where loosening occurs over fractions of a second. Modeling of joint loosening often focuses on complex analytical approaches or high-fidelity simulations using finite element models. While such approaches may succeed for a single bolt, they are unfeasible for use in simulations of entire built-up structures, which may possess dozens to thousands of joints. Thus, there is a need for reduced-order models (ROMs) that capture the dominant governing physics, but at drastically lower computational costs. This research introduces a phenomenological ROM for loosening in bolted joints subjected to axial shock excitation. The model introduces a mathematical relationship between the stiffness of the joint and torque of the fastener and treats the torque as a dynamic internal variable governed by a first-order, ordinary differential equation. The proposed ROM is presented then applied to an experimental study of a split-Hopkinson pressure bar with a threaded joint subjected to extreme shock loading. The results demonstrate that the proposed ROM is able to reproduce the dominant effects of loosening in bolted joints subjected to axial shock excitation.
Design and Modeling of a Continuously Tunable Stiffness Arm for Safe Physical Human–Robot Interaction
Authors: She Yu , Su Hai-Jun , Meng Deshan , Lai Cheng 
Published: September 2019

Abstract
To reduce injury in physical human–robot interactions (pHRIs), a common practice is to introduce compliance to joints or arm of a robotic manipulator. In this paper, we present a robotic arm made of parallel guided beams whose stiffness can be continuously tuned by morphing the shape of the cross section through two four-bar linkages actuated by servo motors. An analytical lateral stiffness model is derived based on the pseudo-rigid-body model and validated by experiments. A physical prototype of a three-armed manipulator is built. Extensive stiffness and impact tests are conducted, and the results show that the stiffness of the robotic arm can be changed up to 3.6 times at a morphing angle of 37 deg. At an impact velocity of 2.2 m/s, the peak acceleration has a decrease of 19.4% and a 28.57% reduction of head injury criteria (HIC) when the arm is tuned from the high stiffness mode to the low stiffness mode. These preliminary results demonstrate the feasibility to reduce impact injury by introducing compliance into the robotic link and that the compliant link solution could be an alternative approach for addressing safety concerns of physical human–robot interactions.
BPNN-QSTR Models for Triazine Derivatives for Lubricant Additives
Authors: Wang Tingting , Wang Zhan , Chen Hao , Dai Kang , Gao Xinlei 
Published: September 2019

Abstract
Triazine derivatives are a kind of lubricant additives with excellent tribological properties. It is of great significance to study the quantitative relationship between their chemical structure and tribological properties. In the present study, the quantitative structure tribo-ability relationships (QSTR) between 20 triazine derivatives and their respective extreme-pressure properties as lubricant additives were analyzed by the back propagation neural network (BPNN) method. The BPNN-QSTR model had satisfactory stability and predictive ability (R2 = 0.9965, R2(LOO) = 0.9195, q2 = 0.8274). The anti-wear model also yielded good predictions (R2 = 0.9757, R2(LOO) = 0.6261, q2 = 0.8022). Two- and three-dimensional structural descriptors were used to analyze molecular structures that affected extreme-pressure and anti-wear properties. The results indicate that the three-dimensional molecular dimensions and the bonding modes of the skeleton atoms in the molecules were important factors. In addition, the effects of N, P, O, and other hetero-atoms on the tribological properties were reflected in their corresponding group types and electronic structures.
Modeling for Microslip Behavior of Lap Joints Based on Non-Gaussian Rough Surfaces
Authors: Li Wei , Zhan Wanglong , Huang Ping 
Published: September 2019

AbstractA general contact model for a lap joint interface based on non-Gaussian surfaces was proposed. The effect of surface topography parameters on microslip behavior in a lap joint interface was studied. Pearson system was applied to produce non-Gaussian surfaces. Combining the topographical-dependent Zhao–Maietta–Chang (ZMC) model with the physical-related Iwan model, the nonlinear constitutive relationship of a lap interface was constructed by using Masing hypothesis. Meanwhile, the probability density function of asperity heights of an infinitely smooth surface was mathematically proved to be a delta function, verifying that the calculated value of friction in the model conforms to the physical law. Gauss-Legendre quadrature was conducted to calculate contact relations of different Pearson distribution surfaces. Furthermore, numerical results of microslip loops under oscillating tangential forces were compared with the published experiments, indicating the present model considering non-Gaussian surfaces could agree well with the experiments.
Magnetohydrodynamic Natural Convection Heat Transfer of Hybrid Nanofluid in a Square Enclosure in the Presence of a Wavy Circular Conductive Cylinder
Authors: Tayebi Tahar , Chamkha Ali J. 
Published: September 2019

Abstract
In this paper, steady natural convective heat transfer and flow characteristics of Al2O3-Cu/water hybrid nanofluid filled square enclosure in the presence of magnetic field has been investigated numerically. The enclosure is equipped with a wavy circular conductive cylinder. The natural convection in the cavity is induced by a temperature difference between the vertical left hot wall and the other right cold wall. The steady 2-D equations of laminar natural convection problem for Newtonian and incompressible mixture are discretized using the finite volume method. The effective thermal conductivity and viscosity of the hybrid nanofluid are calculated using Corcione correlations taking into consideration the Brownian motion of the nanoparticles. A numerical parametric investigation is carried out for different values of the nanoparticles volumic concentration, Hartmann number, Rayleigh number, and the ratio of fluid to solid thermal conductivities. According to the results, the corrugated conductive block plays an important role in controlling the convective flow characteristic and the heat transfer rate within the system.
Series-Type Pendulum Tuned Mass Damper-Tuned Sloshing Damper
Authors: Love J. S. , McNamara K. P. , Tait M. J. , Haskett T. C. 
Published: September 2019

Abstract
A pendulum-type tuned mass damper (TMD)-tuned sloshing damper (TSD) system is proposed as a cost-effective device to reduce wind-induced structural motion. Lagrange's principle is employed to develop an equivalent mechanical model for the system. The sloshing liquid provides additional gravitational restoring force to the pendulum TMD but does not provide a corresponding increase to its inertia. As a result, the natural frequency of the pendulum TMD is increased due to the TSD degree-of-freedom. Shake table testing is conducted on several pendulum TMD-TSD systems that are subjected to harmonic base excitation at discrete frequencies near the natural frequency of the pendulum TMD. The modeled and experimental results are in reasonable agreement when the liquid is not shallow or the response amplitude is not large. The pendulum TMD-TSD is coupled to a linear structure, and it is demonstrated through an analytical study that the device provides performance that is comparable to a traditional TMD. The proposed system is advantageous because it does not require a viscous damping system that is often one of the most costly components of traditional TMDs.
Trends in incidence of total or type 2 diabetes: systematic review
Authors: Magliano Dianna J , Islam Rakibul M , Barr Elizabeth L M , Gregg Edward W , Pavkov Meda E , Harding Jessica L , Tabesh Maryam , Koye Digsu N , Shaw Jonathan E 
Published: September 2019

Abstract

Objective
To assess what proportions of studies reported increasing, stable, or declining trends in the incidence of diagnosed diabetes.

Design
Systematic review of studies reporting trends of diabetes incidence in adults from 1980 to 2017 according to PRISMA guidelines.

Data sources
Medline, Embase, CINAHL, and reference lists of relevant publications.

Eligibility criteria
Studies of open population based cohorts, diabetes registries, and administrative and health insurance databases on secular trends in the incidence of total diabetes or type 2 diabetes in adults were included. Poisson regression was used to model data by age group and year.

Results
Among the 22 833 screened abstracts, 47 studies were included, providing data on 121 separate sex specific or ethnicity specific populations; 42 (89%) of the included studies reported on diagnosed diabetes. In 1960-89, 36% (8/22) of the populations studied had increasing trends in incidence of diabetes, 55% (12/22) had stable trends, and 9% (2/22) had decreasing trends. In 1990-2005, diabetes incidence increased in 66% (33/50) of populations, was stable in 32% (16/50), and decreased in 2% (1/50). In 2006-14, increasing trends were reported in only 33% (11/33) of populations, whereas 30% (10/33) and 36% (12/33) had stable or declining incidence, respectively.

Conclusions
The incidence of clinically diagnosed diabetes has continued to rise in only a minority of populations studied since 2006, with over a third of populations having a fall in incidence in this time period. Preventive strategies could have contributed to the fall in diabetes incidence in recent years. Data are limited in low and middle income countries, where trends in diabetes incidence could be different.

Systematic review registration
Prospero CRD42018092287.
Role of public involvement in the Royal College of Physicians’ Future Hospitals healthcare improvement programme: an evaluation
Authors: Frith Lucy , Hepworth Lauren , Lowers Victoria , Joseph Frank , Davies Elizabeth , Gabbay Mark 
Published: September 2019

ObjectivesThe Royal College of Physician’s (RCP) Future Hospital Programme (FHP) set out a blueprint for a radical new model of care that put patient experience centre stage. This paper reports on the results of an independent evaluation of the FHP and focuses on the role public patient involvement (PPI) played in these projects. The paper explores the perceptions and experiences of those involved in the FHP of how PPI was operationalised in this context, and develops an ‘ex-post’ programme theory of PPI in the FHP. We conclude by assessing the benefits and challenges of this work.SettingSecondary care. The FHP consisted of eight clinician-led healthcare improvement hospital development sites with two phases.ParticipantsDevelopment site clinical teams, patient representatives, the RCP’s Patient and Carer Network, members of the FHP team, and fellows and members of the RCP.Design/methodsWe conducted an independent evaluation of the FHP using FHP documentation and data collected specifically for the evaluation: qualitative interviews, focus groups and a web-based survey.ResultsThe PPI initiatives set out to develop more patient-centred care and improve the patient experience. The mechanisms designed to meet these goals were (1) a programme of PPI in the development site’s projects, (2) a better understanding of patient experience and (3) evaluation of patient experience.ConclusionThis evaluation of the FHP identifies some key elements that need to be considered when attempting to more closely integrate PPI and co-production in service re-design. The structure of FHP over two phases enabled learning from phase I to be incorporated into phase II. Having the PPI representatives closely involved, developing communities of practice, and the oversight and measuring activities acted as ‘disciplinary structures’ that contributed to embedding PPI in the FHP and kept the patient experience at the forefront of the improvement initiatives.
Developing a cerebral palsy-specific preference-based measure for a six-dimensional classification system (CP-6D): protocol for a valuation study
Authors: Bahrampour Mina , Norman Richard , Byrnes Joshua , Downes Martin , Scuffham Paul A 
Published: September 2019

IntroductionCerebral palsy (CP) is a lifelong condition. The CP quality of life (CPQOL) instrument is a frequently used disease-specific instrument to assess health-related quality of life (HRQoL) in people with CP, but it cannot be used to generate quality-adjusted life years (QALY) which are the basis of cost utility analysis (CUA). Generic utility instruments (such as the EQ-5D or SF-6D) that are used to value HRQOL may be insensitive to small but important health changes in children with CP. This study aims to generate a preference-based scoring algorithm for the CP six dimensions (CP-6D), a classification system developed from the CPQOL.Methods and analysisA discrete choice experiment with duration (DCEtto) will be administrated to value health states described by the CP-6D classification system. These health states will be presented to members of Australian general population and parents of children with CP via an online survey. Conditional logit regression will be used to produce the utility algorithm for CP-6D.Ethics and disseminationThe Griffith University Human Research Ethics Committee approved for the study (reference HREC/number 2018/913). The developed algorithm can be applied to previous and future economic evaluation of interventions and treatments targeting people with CP which have used either the CPQOL or CP-6D.
Reliability of instruments that measure situation awareness, team performance and task performance in a simulation setting with medical students
Authors: Hultin Magnus , Jonsson Karin , Härgestam Maria , Lindkvist Marie , Brulin Christine 
Published: September 2019

ObjectivesThe assessment of situation awareness (SA), team performance and task performance in a simulation training session requires reliable and feasible measurement techniques. The objectives of this study were to test the Airways–Breathing–Circulation–Disability–Exposure (ABCDE) checklist and the Team Emergency Assessment Measure (TEAM) for inter-rater reliability, as well as the application of Situation Awareness Global Assessment Technique (SAGAT) for feasibility and internal consistency.DesignMethodological approach.SettingData collection during team training using full-scale simulation at a university clinical training centre. The video-recorded scenarios were rated independently by four raters.Participants55 medical students aged 22–40 years in their fourth year of medical studies, during the clerkship in anaesthesiology and critical care medicine, formed 23 different teams. All students answered the SAGAT questionnaires, and of these students, 24 answered the follow-up postsimulation questionnaire (PSQ). TEAM and ABCDE were scored by four professionals.MeasuresThe ABCDE and TEAM were tested for inter-rater reliability. The feasibility of SAGAT was tested using PSQ. SAGAT was tested for internal consistency both at an individual level (SAGAT) and a team level (Team Situation Awareness Global Assessment Technique (TSAGAT)).ResultsThe intraclass correlation was 0.54/0.83 (single/average measurements) for TEAM and 0.55/0.83 for ABCDE. According to the PSQ, the items in SAGAT were rated as relevant to the scenario by 96% of the participants. Cronbach’s alpha for SAGAT/TSAGAT for the two scenarios was 0.80/0.83 vs 0.62/0.76, and normed χ² was 1.72 vs 1.62.ConclusionTask performance, team performance and SA could be purposefully measured, and the reliability of the measurements was good.
Development of reporting guidance and core outcome sets for seamless, standardised evaluation of innovative surgical procedures and devices: a study protocol for content generation and a Delphi consensus process (COHESIVE study)
Authors: Avery Kerry , Blazeby Jane , Wilson Nicholas , Macefield Rhiannon , Cousins Sian , Main Barry , Blencowe Natalie S , Zahra Jesmond , Elliott Daisy , Hinchliffe Robert , Potter Shelley 
Published: September 2019

IntroductionRigorous evaluation of innovative invasive procedures and medical devices is uncommon and lacks reporting standardisation. Devices may therefore enter routine practice without thorough evaluation, resulting in patient harm. Detailed guidance on how to select and report outcomes at each stage of evaluation is lacking. Development of reporting guidance and core outcome sets (COS) is one strategy to promote safe and transparent evaluation.Methods and analysisA COS, comprising outcome domains applicable to all phases of evaluation of procedure/device introduction and modification and, if necessary, supplementary domains relevant to specific phases or types of innovation (procedure or device), will be developed according to principles outlined by Core Outcome Measures in Effectiveness Trials (COMET) and Core Outcome Set-Standards for Development (COS-STAD) guidelines. Reporting guidance will be developed concurrently. The study will have the following three phases:1. Generation of a list of relevant outcome domains and reporting items identified from (a) published studies, (b) hospital policy documentation, (c) regulatory body documentation and (d) stakeholder qualitative interviews. Identified items/domains will be categorised using a conceptual framework and formatted into Delphi consensus survey questionnaire items.2. Key stakeholders, including 50 patients and 150 professionals (surgeons, researchers, device manufacturers, regulatory representatives, journal editors) sampled from multinational sources, will complete a Delphi survey to score the importance of each reporting item and outcome.3. A consensus meeting with key stakeholders will discuss and agree the final content of the reporting guidance and COS(s).Ethics and disseminationEthical approval has been granted by North East-Newcastle and North Tyneside 1 Health Research Authority Research Ethics Committee (18/NE/0378). Dissemination strategies include scientific meeting presentations, peer-reviewed journal publications, development of plain English summaries/materials, patient engagement events, development of a social media identity, workshops and other events.
Methotrimeprazine versus haloperidol in palliative care patients with cancer-related nausea: a randomised, double-blind controlled trial
Authors: Hardy Janet Rea , Skerman Helen , Philip Jennifer , Good Phillip , Currow David C , Mitchell Geoffrey , Yates Patsy 
Published: September 2019

ObjectivesMethotrimeprazine is commonly used for the management of nausea but never tested formally against other drugs used in this setting. The aim was to demonstrate superior antiemetic efficacy.DesignDouble-blind, randomised, controlled trial of methotrimeprazine versus haloperidol.Setting11 palliative care sites in Australia.ParticipantsParticipants were >18 years, had cancer, an average nausea score of ≥3/10 and able to tolerate oral medications. Ineligible patients had acute nausea related to treatment, nausea for which a specific antiemetic was indicated, were about to undergo a procedure or had received either of the study drugs or a change in glucocorticoid dose within the previous 48 hours.InterventionsBased on previous studies, haloperidol was used as the control. Participants were randomised to encapsulated methotrimeprazine 6·25 mg or haloperidol 1·5 mg one time or two times per day and assessed every 24 hours for 72 hours.Main outcome measuresA ≥two-point reduction in nausea score at 72 hours from baseline. Secondary outcome measures were as follows: complete response at 72 hours (end nausea score less than 3), response at 24 and 48 hours, vomiting episodes, use of rescue antiemetics, harms and global impression of change.ResultsResponse to treatment at 72 hours was 75% (44/59) in the haloperidol (H) arm and 63% (36/57) in the methotrimeprazine (M) arm with no difference between groups (intention-to-treat analysis). Complete response rates were 56% (H) and 51% (M). In theper protocolanalysis, there was no difference in response rates: (85% (44/52) (H) and 74% (36/49) (M). Completeper protocolresponse rates were 64% (H) and 59% (M). Toxicity worse than baseline was minimal with a trend towards greater sedation in the methotrimeprazine arm.ConclusionThis study did not demonstrate any difference in response rate between methotrimeprazine and haloperidol in the control of nausea.Trial registration numberACTRN 12615000177550.