bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Preliminary Analysis of the Variable Axisymmetric Divergent Bypass Dual Throat Nozzle
Authors: Wang Yangsheng , Xu Jinglei , Huang Shuai , Jiang Jingjing , Pan Ruifeng 
Published: January 2020

Abstract
Turbofan engines with afterburners usually have variable nozzle throat area, and the nozzle throat area may increase by 50–100% during afterburning. An axisymmetric divergent bypass dual throat nozzle (ADBDTN) can offer high thrust vectoring efficiency without requiring additional secondary flow in the pitch and yaw directions. In this study, a variable ADBDTN configuration with flow adaptive capability, wide nozzle throat area adjustment range, and excellent overall performance was designed and investigated numerically. The nozzle throat and exit area can be controlled mechanically, while thrust vectoring is achieved via fluidic methods. Both the original variable geometry schemes and their corresponding improved schemes, namely, “slider-rocker mechanism & rotation” (SRM-R) and “slider-rocker mechanism & slide” (SRM-S) schemes, along with their improved schemes, were proposed and investigated. Results indicated that compared to the original variable geometry schemes, the nozzle configurations with improved variable geometry schemes not only achieve 50% increase in the nozzle throat area but also acquire flow adaptive capability and excellent overall performance by appropriately adjusting the nozzle exit area. At a nozzle pressure ratio (NPR) of 4.47, the highest thrust coefficient reaches 0.940; the largest pitch thrust-vector angle is 19.52 deg; and the discharge coefficients are 0.968 and 0.970 under the nonafterburning and afterburning states, respectively. In addition, compared to the improved SRM-R scheme, the nozzle configuration with improved SRM-S scheme possesses better overall performance.
Reynolds Number Dependence of Zero Pressure Gradient Turbulent Boundary Layers Including Third-Order Moments and Spatial Correlations
Authors: Volino Ralph J. 
Published: January 2020

Abstract
Measurements were made in zero pressure gradient turbulent boundary layers on a smooth wall, at momentum thickness Reynolds numbers, ranging from 800 to 6340. The experiments were conducted in a recirculating water tunnel. Two-component velocity profiles were acquired using laser Doppler velocimetry at five streamwise stations and three different freestream velocities. Velocity field measurements were acquired using particle image velocimetry in streamwise-wall normal and streamwise–spanwise planes. Profiles of mean velocity and turbulence statistics including the Reynolds normal and shear stresses, and triple products of the velocity fluctuations are presented in both inner and outer coordinates. Variations in the profiles at representative distances from the wall are presented and quantified as functions of Reynolds number. The triple products are explained in terms of transport of Reynolds stresses though motions associated with quadrant analysis, and variation with Reynolds number is consistent with that of Reynolds stresses. The structure of turbulence was considered through two-point correlations of the fluctuations in velocity fields. In general, the shape and inclination angles of the structures did not change with Reynolds number, but some streamwise and spanwise growth was observed as Reynolds number increased.
Numerical Simulation of Tidal Breathing Through the Human Respiratory Tract
Authors: Azarnoosh Jamasp , Sreenivas Kidambi , Arabshahi Abdollah 
Published: January 2020

Abstract
The objective of this study is to explore the complexity of airflow through the human respiratory tract by carrying out computational fluid dynamics simulation. In order to capture the detailed physics of the flow in this complex system, large eddy simulation (LES) is performed. The crucial step in this analysis is to investigate the impact of breathing transience on the flow field. In this connection, simulations are carried out for transient breathing in addition to peak inspiration and expiration. To enable a fair comparison, the flowrates for constant inspiration/expiration are selected to be identical to the peak flowrates during the transient breathing. Physiologically appropriate regional ventilation for two different flowrates is induced. The velocity field and turbulent flow features are discussed for both flowrates. The airflow through the larynx is observed to be significantly complex with high turbulence level, recirculation, and secondary flow while the level of turbulence decreases through the higher bifurcations.
Influence of Emergency Stop Operation for Strength of Brazed Structure With Rectangular Fins and Plates in Liquefied Natural Gas Heat Exchanger
Authors: Ma Hongqiang , Song Xingpeng , Liu Yemin , Liang Nuo , Han Jianping , Hou Caiqin 
Published: January 2020

Abstract
In order to ensure the structural safety of a liquefied natural gas (LNG) heat exchanger in emergency stop operation process, the strength of a brazed structure with rectangular fins and plates is investigated by means of the finite element method. The microstructure of brazed joints and brazing filler is tested by metallographic examination with a scanning electron microscope (SEM). The results show that the maximum shear stress is the main reason for the structural failure at the brazing seam while the brazed joint is mainly subjected to the maximum normal stress. The peak value of the Von Mises equivalent stress in brazed structure with rectangular fins and plates linearly increases with the HMR pressure when the temperature difference is less than 10 K between HMR and LMR. At the same time, the peak value of Von Mises equivalent stress also increases with the equilibrium temperature and temperature difference between LMR and HMR. The aggregation of the elemental Si in the brazed joints and brazing seam will exacerbate the structural safety of the brazed structure in the emergency stop operation process. The above results provide some constructive guidance for the emergency stop operational process for an LNG heat exchanger.
In Situ Measurement of Carbon Nanotube Growth Kinetics in a Rapid Thermal Chemical Vapor Deposition Reactor With Multizone Infrared Heating
Authors: Abdulhafez Moataz , Lee Jaegeun , Bedewy Mostafa 
Published: January 2020

Abstract
Understanding and controlling the growth of vertically aligned carbon nanotube (VACNT) forests by chemical vapor deposition (CVD) is essential for unlocking their potential as candidate materials for next generation energy and mass transport devices. These advances in CNT manufacturing require developing in situ characterization techniques capable of interrogating how CNTs grow, interact, and self-assemble. Here we present a technique for real-time monitoring of VACNT forest height kinetics applied to a unique custom designed rapid thermal processing (RTP) reactor for CVD of VACNTs. While the integration of multiple infrared heating lamps enables creating designed spatiotemporal temperature profiles inside the reactor, they pose challenges for in situ measurements. Hence, our approach relies on contrast-adjusted videography and image processing, combined with calibration using 3D optical microscopy with large depth-of-field. Our work enables reliably measuring VACNT growth rates and catalytic lifetimes, which are not possible to measure using ex situ methods.
Multi-stage arc magma evolution recorded by apatite in volcanic rocks
Authors: Nathwani Chetan L. , Loader Matthew A. , Wilkinson Jamie J. , Buret Yannick , Sievwright Robert H. , Hollings Pete 
Published: January 2020

AbstractProtracted magma storage in the deep crust is a key stage in the formation of evolved, hydrous arc magmas that can result in explosive volcanism and the formation of economically valuable magmatic-hydrothermal ore deposits. High magmatic water content in the deep crust results in extensive amphibole ± garnet fractionation and the suppression of plagioclase crystallization as recorded by elevated Sr/Y ratios and high Eu (high Eu/Eu*) in the melt. Here, we use a novel approach to track the petrogenesis of arc magmas using apatite trace element chemistry in volcanic formations from the Cenozoic arc of central Chile. These rocks formed in a magmatic cycle that culminated in high-Sr/Y magmatism and porphyry ore deposit formation in the Miocene. We use Sr/Y, Eu/Eu*, and Mg in apatite to track discrete stages of arc magma evolution. We apply fractional crystallization modeling to show that early-crystallizing apatite can inherit a high-Sr/Y and high-Eu/Eu* melt chemistry signature that is predetermined by amphibole-dominated fractional crystallization in the lower crust. Our modeling shows that crystallization of the in situ host-rock mineral assemblage in the shallow crust causes competition for trace elements in the melt that leads to apatite compositions diverging from bulk-magma chemistry. Understanding this decoupling behavior is important for the use of apatite as an indicator of metallogenic fertility in arcs and for interpretation of provenance in detrital studies.
Is kidney function associated with primary open-angle glaucoma? Findings from the Asian Eye Epidemiology Consortium
Authors: Tham Yih-Chung , Tao Yijin , Zhang Liang , Rim Tyler Hyung Taek , Thakur Sahil , Lim Zhi Wei , Chee Miao Li , Bikbov Mukharram M , Kazakbaeva Gyulli M , Wang Ningli , Cao Kai , Hao Jie , Nangia Vinay , Panda-Jonas Songhomitra , Wang Ya Xing , Wong Ian Y , Chan Jonathan Cheuk Hung , Meng Qianli , Sabanayagam Charumathi , Wong Tien Y , Jonas Jost B , Zhong Hua , Cheng Ching-Yu 
Published: January 2020

Aim
To comprehensively examine the association between kidney function and primary open angle glaucoma (POAG) in a large consortium of multiple Asian population-based studies.

Methods

28 925 participants (57 340 eyes) from 9 population-based studies (from China, Hong Kong, India, Korea, Russia, Singapore) of the Asian Eye Epidemiology Consortium were included. Across all studies, POAG was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria. Estimated glomerular filtration rate (eGFR) was calculated from serum creatinine. Chronic kidney disease (CKD) was defined as eGFR<60 mL/min/1.73 m
2
. Eye-specific data were pooled from each study. Multivariable regression analysis with generalised estimating equation models was performed to evaluate the associations between kidney function with POAG and intraocular pressure (IOP).

Results

After adjusting for age, gender, study group, hypertension, diabetes, hyperlipidaemia, body mass index, smoking status and IOP, lower eGFR (per 10 mL/min/1.73 m
2
decrease) was not significantly associated with POAG (OR=1.01; p=0.77). Presence of CKD was also not significantly associated with POAG (OR=1.01; p=0.739). Furthermore, lower eGFR and presence of CKD were not associated with IOP (all p≥0.12), However, in the subgroup of combined Korean and Chinese individuals, significant associations between lower eGFR (OR=1.09; 95% CI 1.00 to 1.18; p=0.048) and severe kidney function decline (<45 mL/min/1.73 m
2
; OR=2.57; 95% CI 1.34 to 4.93; p=0.004) with POAG, were observed.

Conclusion
In this large pooled-analysis of multiple Asian population-based studies, our findings suggest that the association between CKD and POAG may only be present in East Asians specifically but not in the overall Asian population. Further evaluation in Japanese population is warranted to confirm this observation.
Outcomes in randomised controlled trials of multifocal lenses in cataract surgery: the case for development of a core outcome set
Authors: Evans Jennifer R , de Silva Samantha R , Ziaei Mohammed , Kirthi Varo , Leyland Martin D 
Published: January 2020

Background/aimsTo describe and summarise the outcomes reported in randomised controlled trials of multifocal versus monofocal intraocular lenses in cataract surgery.MethodsWe identified all randomised controlled trials of multifocal versus monofocal lenses in a Cochrane review (last search date June 2016). We extracted and summarised data on all outcomes reported using the framework of domain, measurement, metric and method of aggregation.ResultsAll studies collected data on distance and near visual acuity but there was considerable variation in the measures used and whether these outcomes were unaided or best corrected. Most studies reported final value measurements, rather than change from baseline. Approximately half of the studies reported data as a continuous measure only, one-third reported both continuous and categorical measures and a minority reported categorical measures only. There was little consensus as to cut-points. Although a majority of studies included one or more patient-reported outcome measures, none of the studies reported patient involvement in the choice of outcomes.ConclusionThe collection and analysis of data on outcome measures in studies of multifocal intraocular lenses in cataract surgery are complicated. As a result, there is considerable heterogeneity in collection and reporting in the medical literature. This makes it difficult to synthesise such data to provide robust estimates of effect and is a potential source of research waste. Investigators in this field must produce a core outcome set that is informed by patients’ views and we propose an initial set of outcomes on which these could be based.
Accuracy of the ISNT rule and its variants for differentiating glaucomatous from normal eyes in a population-based study
Authors: Maupin Edouard , Baudin Florian , Arnould Louis , Seydou Allasane , Binquet Christine , Bron Alain M , Creuzot-Garcher Catherine P 
Published: January 2020

AimsTo evaluate the accuracy of the ISNT rule (I=inferior, S=superior, N=nasal, T=temporal) and its variants with neuroretinal rim width and retinal nerve fibre layer (RNFL) thickness measurements differentiating normal from glaucomatous eyes.MethodsThe diagnosis accuracy of the ISNT rule and its variants was evaluated in a population-based study. Neuroretinal rim widths were measured on monoscopic optic disc photographs with an image-processing program. RNFL thickness measurements were obtained with spectral-domain optical coherence tomography (SD-OCT).ResultsIn this study including 940 normal subjects and 93 patients with glaucoma, the sensitivity of the ISNT rule with optic disc photographs was 94.1% (95% CI 90.2 to 98.1), whereas its specificity was 49.2% (46.9 to 51.6). When using the IST rule, the sensitivity decreased to 69.9% (62.1 to 77.6) with a higher specificity, 87.0% (85.3 to 88.6). All the diagnosis indicators were somewhat lower for the different rules using RNFL thickness: the sensitivity of the ISNT rule was 79.4% (72.6 to 86.2) and its specificity was 34.1% (31.9 to 36.4). With the IST rule, the sensitivity decreased to 50.0% (41.6 to 58.4) while the specificity increased to 64.9% (62.7 to 67.2).ConclusionsThe ISNT and IST rules applied to neuroretinal rim width measurement by optic disc photographs are useful and simple tools for differentiating normal from glaucomatous eyes. The translation of these rules to RNFL thickness by SD-OCT is of limited value.
Prehospital critical care is associated with increased survival in adult trauma patients in Scotland
Authors: Maddock Alistair , Corfield Alasdair R , Donald Michael J , Lyon Richard M , Sinclair Neil , Fitzpatrick David , Carr David , Hearns Stephen 
Published: January 2020

BackgroundScotland has three prehospital critical care teams (PHCCTs) providing enhanced care support to a usually paramedic-delivered ambulance service. The effect of the PHCCTs on patient survival following trauma in Scotland is not currently known nationally.MethodsNational registry-based retrospective cohort study using 2011–2016 data from the Scottish Trauma Audit Group. 30-day mortality was compared between groups after multivariate analysis to account for confounding variables.ResultsOur data set comprised 17 157 patients, with a mean age of 54.7 years and 8206 (57.5%) of male gender. 2877 patients in the registry were excluded due to incomplete data on their level of prehospital care, leaving an eligible group of 14 280. 13 504 injured adults who received care from ambulance clinicians (paramedics or technicians) were compared with 776 whose care included input from a PHCCT. The median Injury Severity Score (ISS) across all eligible patients was 9; 3076 patients (21.5%) met the ISS>15 criterion for major trauma. Patients in the PHCCT cohort were statistically significantly (all p<0.01) more likely to be male; be transported to a prospective Major Trauma Centre; have suffered major trauma; have suffered a severe head injury; be transported by air and be intubated prior to arrival in hospital. Following multivariate analysis, the OR for 30-day mortality for patients seen by a PHCCT was 0.56 (95% CI 0.36 to 0.86, p=0.01).ConclusionPrehospital care provided by a physician-led critical care team was associated with an increased chance of survival at 30 days when compared with care provided by ambulance clinicians.
Injuries among all-terrain vehicle users: a population-based study
Authors: Siman-Tov Maya , Marom-Trabelsi Inbar , Radomislensky Irina , Bodas Moran , Peleg Kobi 
Published: January 2020

BackgroundThe use of off-road vehicles such as all-terrain vehicles (ATVs) and recreational off-highway vehicles has increased in recent years. A higher percentage of patients hospitalised following ATV crashes suffered severe injuries, compared with those hospitalised following other MVCs.ObjectiveTo identify incidence of ATV-related injury and characterise groups with higher prevalence.MethodsA retrospective study of the Israel National Trauma Registry data between years 2008 and 2016. ATV crash victims were compared with other types of MVC casualties according to demographics, injuries and hospital resource utilisation. Identifying groups with greater prevalence for severe injuries caused by ATV crashes was conducted using logistic regressions.ResultsAn increase of 49% in the number of casualties hospitalised following an ATV crash was observed between 2013 and 2016. Non-Jews, males and users 15–29 years old were hospitalised at a higher rate compared with their proportion in the population. ATV crash casualties were more severely injured compared with other MVC casualties (22% vs 14%), had longer hospital length of stay (8+ days) (25% vs 18%), more admissions to intensive care units (16% vs 10%) and underwent more surgery (39% vs 26%, respectively). Males, non-Jews and casualties who did not wear a helmet were about two times more likely to suffer from severe head injury (95% CI 1.20 to 3.60, 1.41 to 2.75 and 1.27 to 4.73, respectively).ConclusionsAn increase in ATV-related casualties was observed. A customised safety intervention programme is needed that targets demographic groups identified with higher injury incidence. Awareness of legislated and common sense ATV safety practices, specifically helmet use, should be raised.
IMPACT and CRASH prognostic models for traumatic brain injury: external validation in a South-American cohort
Authors: Wongchareon Kwankaew , Thompson Hilaire J , Mitchell Pamela H , Barber Jason , Temkin Nancy 
Published: January 2020

ObjectiveTo develop a robust prognostic model, the more diverse the settings in which the system is tested and found to be accurate, the more likely it will be generalisable to untested settings. This study aimed to externally validate the International Mission for Prognosis and Clinical Trials in Traumatic Brain Injury (IMPACT) and Corticosteroid Randomization after Significant Head Injury (CRASH) models for low-income and middle-income countries using a dataset of patients with severe traumatic brain injury (TBI) from the Benchmark Evidence from South American Trials: Treatment of Intracranial Pressure study and a simultaneously conducted observational study.MethodA total of 550 patients with severe TBI were enrolled in the study, and 466 of those were included in the analysis. Patient admission characteristics were extracted to predict unfavourable outcome (Glasgow Outcome Scale: GOS<3) and mortality (GOS 1) at 14 days or 6 months.ResultsThere were 48% of the participants who had unfavourable outcome at 6 months and these included 38% who had died. The area under the receiver operating characteristic curve (AUC) values were 0.683–0.775 and 0.640–0.731 for the IMPACT and CRASH models respectively. The IMPACT CT model had the highest AUC for predicting unfavourable outcomes, and the IMPACT Lab model had the best discrimination for predicting 6-month mortality. The discrimination for both the IMPACT and CRASH models improved with increasing complexity of the models. Calibration revealed that there were disagreement between observed and predicted outcomes in the IMPACT and CRASH models.ConclusionThe overall performance of all IMPACT and CRASH models was adequate when used to predict outcomes in the dataset. However, some disagreement in calibration suggests the necessity for updating prognostic models to maintain currency and generalisability.
Preclinical evaluation of the ANCD thrombectomy device: safety and efficacy in a swine clot model
Authors: Sanchez Sonia , Bailey Lynn , Ducore Rebecca , Andersson Tommy , Nogueira Raul , Cognard Christophe , Ribo Marc , Villanova Helena , Rios Anna , Galve Iñaki 
Published: January 2020

BackgroundThe Advanced Thrombectomy System (ANCD) provides a new funnel component designed to reduce clot fragmentation and facilitate retrieval in patients with stroke by locally restricting flow, allowing distal aspiration in combination with a stent retriever (SR).ObjectiveTo evaluate the preclinical efficacy and safety of the ANCD in a swine clot model.MethodsSoft and firm clots were implanted in the lingual and cervical arteries of 11 swine to obtain Thrombolysis in Cerebral Infarction (TICI) 0 blood flow. Mechanical thrombectomy was performed with either a balloon guide catheter+Solitaire 2 stent retriever (BGC+SR, n=13) or ANCD+SR (n=13). TICI flow was evaluated and successful revascularization was defined as TICI 3 (normal perfusion). To characterize safety, a total of 3 passes were performed in each vessel independent of recanalization. Tissues were explanted for histopathological analysis after 3 and 30 days, respectively.ResultsFirst pass reperfusion rates were ANCD+SR: 69% and BGC+SR: 46%. Reperfusion increased after the third pass in both groups (ANCD+SR: 100%, vs BGC+SR: 77%). Recanalization was achieved after an average of 1.4 and 1.9 passes in ANCD+SR and BGC+SR (p=0.095), respectively. Vessel injury was comparable in both groups; endothelial loss at 3 days was the most common injury seen (ANCD+SR: 1.78±1.22; BGC+SR: 2.03±1.20; p=0.73), while other histopathological markers were absent or minimal. Tissues downstream from targeted vessels also showed absence or minimal lesions across both groups.ConclusionsResults in a swine clot model support the high efficacy of the ANCD+SR without causing clinically significant vessel injury potentially related to the new funnel component.