bluuebunny/crossref_metadata_2025_split huggingface dataset:
Static Nodes of an Axially Moving String With Time-Varying Supports
Authors: Lu Lei , Yang Xiao-Dong , Zhang Wei 
Published: February 2020

Abstract
By investigating the transverse vibrations of an axially moving string with time-varying supports, the existence and the pattern of static nodes are studied based on the assumed mode method and the linear superposition method. The explicit expressions for the response of the system with five different boundary conditions are illustrated. Traditional excited static strings show nodes when resonance occurs. However, it is found in this study that the static nodes of axially moving strings appear under arbitrary frequency even far away from resonance, if the excitation frequency is higher than the fundamental frequency. The varying nodes and frequencies under different time-varying supports are revealed.
Controlling Porosity of Anode Support in Tubular Solid Oxide Fuel Cells by Freeze Casting
Authors: Emley Benjamin , Panthi Dhruba , Du Yanhai , Yao Yan 
Published: February 2020

Abstract
Precise porosity control is highly desirable for improving the electrochemical performance of solid oxide fuel cells (SOFCs). Freeze casting is an established method for enabling high bulk porosity in structures and controlling pore orientation. In this study, freeze casting was used to fabricate tubular, anode-supported SOFCs with aligned and varying amounts of porosity by controlling the solids/water ratio in different casting slurries. SOFCs were prepared with a Ni/yttria and scandia stabilized zirconia (ScYSZ) anode support (AS), an anode functional layer (AFL), a ScYSZ electrolyte, a lanthanum strontium manganite (LSM)/ScYSZ cathode interlayer (CIL), and an LSM cathode. The permeability of the anode support was found to increase from 1.4 × 10−2 to 1.8 × 10−2 m2 as porosity was increased from 57 to 64 vol%, while the total cell resistance decreased by 35% from 0.93 to 0.60 Ohm cm2. When evaluated with 30 vol% H2 as the fuel at 800 °C, the decrease of concentration polarization enabled an increase in electrochemical performance by 42% from 0.35 to 0.50 W/cm2 as the porosity in the anode support was increased. Mechanical strength characterization using a three-point method showed there is a practical upper limit of the amount of porosity that can be designed into the anode support. This work paves a way for controlling porosity by freeze casting and understanding the correlation between porosity and concentration polarization losses in SOFCs.
Influence of Hemodialysis Catheter Insertion on Hemodynamics in the Central Veins
Authors: Park Min-Hyuk , Qiu Yue , Cao Haoyao , Yuan Ding , Li Da , Jiang Yi , Peng Liqing , Zheng Tinghui 
Published: February 2020

Abstract
Central venous catheter (CVC) related thrombosis is a major cause of CVC dysfunction in patients under hemodialysis. The aim of our study was to investigate the impact of CVC insertion on hemodynamics in the central veins and to examine the changes in hemodynamic environments that may be related to thrombus formation due to the implantation of CVC. Patient-specific models of the central veins with and without CVC were reconstructed based on computed tomography images. Flow patterns in the veins were numerically simulated to obtain hemodynamic parameters such as time-averaged wall shear stress (TAWSS), oscillating shear index (OSI), relative residence time (RRT), and normalized transverse wall shear stress (transWSS) under pulsatile flow. The non-Newtonian effects of blood flow were also analyzed using the Casson model. The insertion of CVC caused significant changes in the hemodynamic environment in the central veins. A greater disturbance and increase of velocity were observed in the central veins after the insertion of CVC. As a result, TAWSS and transWSS were markedly increased, but most parts of OSI and RRT decreased. Newtonian assumption of blood flow would overestimate the increase in TAWSS after CVC insertion. High wall shear stress (WSS) and flow disturbance, especially the multidirectionality of the flow, induced by the CVC may be a key factor in initiating thrombosis after CVC insertion. Accordingly, approaches to decrease the flow disturbance during CVC insertion may help restrain the occurrence of thrombosis. More case studies with pre-operative and postoperative modeling and clinical follow-up need to be performed to verify these findings. Non-Newtonian blood flow assumption is recommended in computational fluid dynamics (CFD) simulations of veins with CVCs.
Biomechanical Relationships Between Manual Wheelchair Steering and the Position of the Human Body's Center of Gravity
Authors: Wieczorek B. , Kukla M. 
Published: February 2020

Abstract
The purpose of this investigation was to analyze the impact of differential steering of a wheelchair with a pushrim on changes in the position of the body's center of gravity. The method assumed measuring the wheelchair trajectory and the body's center of gravity and determining the transverse relocation of the measured body's center of gravity in relation to a point on the wheelchair trajectory. Twenty-seven measurement tests which demonstrated various wheelchair trajectories were carried out within the investigation. The trajectories were 10 to 15 m long and involved moving forward (test 2), reversing (test 3), turning left (test 1) and right (test 4). The factor of deviation of the center of gravity of human body from the wheelchair trajectory was determined for selected characteristic turning maneuvers. The measured values ranged from 51 to 192 mm. The impact of the wheelchair trajectory on the position of the body's center of gravity was demonstrated as a result of this investigation. Consequently, a trajectory deviation factor for relocation of the human body weight on one side of the wheelchair has been demonstrated.
Quantification of Passive Ventilation Produced by Manual Chest Compressions Using a New Cardiopulmonary Resuscitation Feedback Device
Authors: Taleb Lhoucine Ben , Essoukaki Elmaati , Mouhsen Azeddine , Lyazidi Aissam , Assir Abdelhadi , Harmouchi Mohammed , Rattal Mourad 
Published: February 2020

AbstractSeveral studies have shown that chest compressions (CC) alone may produce in addition to blood circulation, a short-term passive ventilation. However, it is not clear whether high CC quality may produce in even greater amount of ventilation volumes. The aim of this study was to evaluate whether CC, using a new feedback device, can produce a substantial and sustainable passive volumes compared to standard CC. Thirty inexperienced volunteers performed CC for 2 min on a developed thoracic lung model and using a new feedback device. Participants were randomized into two groups that performed either CC with feedback first, followed by a trial without feedback, or vice versa. Efficient compression rate (correct CC rate and depth simultaneously) was significantly higher in feedback session (43.6% versus 25.5%; P = 0.006). As well, CC rate and depth efficiency were improved with feedback. Moreover, average tidal volumes and minute volumes that occurred during CC alone were significantly improved in feedback session (79.8 ± 5 ml versus 72.9 ± 7 ml) and (8.8 l/min versus 7.9 l/min), respectively (P &lt; 0.001). Yet, no significant difference was found between the first and the 90th second interval (9.04 l/min versus 8.68 l/min, P = 0.163) in the feedback session. Conversely, a significant difference was evident after the first 15th seconds interval without feedback (8.77 l/min initially versus 8.38 l/min; P = 0.041). This study revealed that the new CPR feedback device improved CC quality in inexperienced volunteers. As well, the passive ventilation volumes were significantly increased and sustained when the device was used.
The Effect of Isentropic Exponent on Transonic Turbine Performance
Authors: Baumgärtner David , Otter John J. , Wheeler Andrew P. S. 
Published: February 2020

Abstract
The isentropic exponent is one of the most important properties affecting gas dynamics. Nonetheless, its effect on turbine performance is not well known. This paper discusses a series of experimental and computational studies to determine the effect of isentropic exponent on the flow field within a turbine vane. Experiments are performed using a newly modified transient wind tunnel that enables annular cascade testing with a wide range of working fluids and operating conditions. For the present study, tests are undertaken using air, CO2, R134a, and argon, giving a range of isentropic exponent from 1.08 to 1.67. Measurements include detailed wall static pressures that are compared with computational simulations. Our results show that over the range of isentropic exponents tested here, the loss can vary between 20% and 35%, depending on vane exit Mach number. The results are important for future turbines operating with real-gas effects and/or those where high gas temperatures can lead to variations in the isentropic exponent.
Using a New Entropy Loss Analysis to Assess the Accuracy of RANS Predictions of an High-Pressure Turbine Vane
Authors: Zhao Yaomin , Sandberg Richard D. 
Published: February 2020

Abstract
Entropy loss is widely used to quantify the efficiency of components in turbomachines, and empirical relations have been developed to estimate the contribution of different mechanisms. However, further analysis is still needed to not only get a deeper insight of the physics but also to more accurately quantify the loss generation caused by different terms. In the present study, the entropy transport equations based on averaged flow quantities are first derived, and the entropy generation process is fully decomposed into several terms representing different physical mechanisms, such as mean viscous dissipation, turbulence production, mean, and turbulent heat flux, etc. This decomposition framework is then applied to high-resolution large-eddy simulation (LES) and Reynolds-averaged Navier–Stokes (RANS) results of a VKI LS-89 HPT vane, and a detailed quantification of different entropy generation terms is obtained. The results show that the entropy generation caused by mean flow features like mean viscous dissipation and mean heat flux are in close agreement between LES and RANS, indicating that RANS provides an overall good prediction for the mean flow. Furthermore, we find that turbulence production plays an important role in entropy generation as it represents the energy extracted from the mean flow to turbulent fluctuations. However, the difference between RANS and LES results for the turbulence production term is not negligible, particularly in the wake region. This implies that the failure of RANS to predict the correct total loss might be largely caused by errors in capturing the correct turbulence production in the near wake region.
Predicting Multi-Order Magnetic Polaritons Resonance in SiC Slit Arrays by Mutual Inductor–Inductor–Capacitor Circuit Model
Authors: Guo Yanming , Xiong Bo , Shuai Yong 
Published: February 2020

Abstract
Magnetic polariton (MP) that couples electromagnetic waves with magnetic excitation can be predicted by equivalent inductor–capacitor (LC) circuit model. However, when the resonance frequencies of MP and surface phonon polariton (SPhP) is close, the absorption and transmission peaks predicted by LC circuit model are far different from solving electromagnetic field calculation results. In this work, absorption and transmission enhancements with a SiC slit array are theoretically demonstrated within the SiC phonon absorption band with finite difference time-domain (FDTD) method. The interactions between SPhP and MP are confirmed by electromagnetic field distributions. Mutual inductor–inductor–capacitor (MLC) circuit model is used to predict the multiorder MP resonance conditions, and the coupling between MP and SPhP is treated as a mutual inductor in MLC model. The geometric effects of SiC slit arrays are investigated and MLC circuit model works well. This study may contribute to the design and prediction of thermal radiative properties and micro-/nanostructure metamaterials thermal radiative properties database building.
Nonlinear Analysis of Effect of Rigid Body Rotation on Ferroconvection
Authors: Melson Anthony Christy , Sekhar G. N. , Siddheshwar P. G. 
Published: February 2020

AbstractThe paper presents a numerical study of the effect of rotation on convection and heat transport in ferromagnetic liquids. The conditions for validity of principle of exchange of stabilities have been identified by means of linear stability analysis. The nonlinear stability analysis has been done using the streamline formulation. The systems of equations derived with the help of minimal Fourier series representation are analogous to those of the Lorenz model. The effect of different parameters on heat transport has been quantified through the average Nusselt number obtained from the solution of the scaled Lorenz model. Certain unusual effects of buoyancy magnetic parameter and nonbuoyancy magnetic parameter on heat transport are reported.
Unsteady Laminar Pulsating Flow in a Saturated Porous Microchannel in the Presence of Electrical Double-Layer Effects
Authors: Niazi Muhammad Dilawar Khan , Xu Hang 
Published: February 2020

Abstract
The forced convection of a pulsating flow in a saturated porous parallel-plates microchannel driven by a periodic pressure in the presence of an electrical double layer is investigated. Such configuration is very important but seldom considered in literature. Analytical solutions for electrical, momentum, and temperature fields are obtained by means of a substitution approach. The results show that the flow fields depend highly on the electro-osmotic parameter κ, the angular velocity parameter Ω, as well as the Darcy number Da.
New Approach of Triumphing Temperature Nonuniformity and Heat Transfer Performance Augmentation in Micro Pin Fin Heat Sinks
Authors: Kumar Ritunesh , Abiev Rufat , Ribatski Gherhardt , Abdullah Shekh , Vasilev Maksim 
Published: February 2020

Abstract
This study is the first part of the development of improved micro pin fin heat sink (MPFHS) for the thermal management of modern microprocessor chip cooling. In the current numerical study, a new fluid flow distribution scheme for MPFHS has been proposed for triumphing over surface temperature nonuniformity problem—one of the most critical issues interfering with the thermal management of modern microprocessors chip cooling. It is established that fluid, if supplied from the confronting sides (front/side directions) of the MPFHS, helps in mitigating temperature nonuniformity and intensifies heat transfer rate. Fluid starts enjoying following paybacks on account of proposed change: the benefits of the developing flow even in adverse temperature zones of the conventional design, enriched secondary channels fluid flow, and rigorous mixing of the cooling fluid between the primary and the secondary channels. Two front facing multi-inlet designs (MPFHSMI,F and MPFHSMI,FH) and one side facing multi-inlet design (MPFHSMI,SH) are conceptualized and compared with the conventional design MPFHSCD. Base surface temperature nonuniformity reduces 7.6 °C, 24 °C, and 7.4 °C by the MPFHSMI,F, MPFHSMI,FH, and MPFHSMI,SH designs, respectively. Average Nusselt number for the cases MPFHSMI,F, MPFHSMI,FH, and MPFHSMI,SH is found 26.7%, 52.3%, and 70.9% higher than the conventional design of MPFHS. Overall thermal performance factor of one design MPFHSMI,FH is found 1.66 at the applied heat flux of 125 W/cm2.
Exercise Time and Intensity: How Much Is Too Much?
Authors: Gottschall Jinger S. , Davis Joshua J. , Hastings Bryce , Porter Heather J. 
Published: February 2020

The growing prevalence and popularity of interval training necessitate additional guidelines in regard to maximal levels of time and intensity. Purpose: To correlate salivary hormones and time in varying heart-rate (HR) zones. The hypothesis was that chronic exercise durations >9% of total exercise time in the >90% maximum HR zone would lead to decreased variation in salivary cortisol concentration after exercise in a 2-bout high-intensity protocol compared with less or more time in this zone. Methods: A total of 35 healthy adults who regularly exercised for an average of 8 hours per week recorded their HR during every training session for 3 weeks. Later, they completed an experimental day composed of two 30-minute high-intensity interval sessions separated by 4 hours of nonactive recovery. The authors collected saliva samples before, immediately following, and 30 minutes after each exercise session to assess changes in cortisol concentrations. Results: There was a correlation between weekly time training at an intensity >90% maximum HR and the variables associated with overtraining. Salivary cortisol concentration fluctuated less in the participants who exercised in this extreme zone for >40 minutes per week (P < .001). Conclusion: Based on the current study data, for individuals who regularly exercise, 4% to 9% total training time above 90% maximum HR is the ideal duration to maximize fitness and minimize symptoms related to overreaching.
Using the Larry Nassar Case to Create a Coach Education Module to Prompt Social Change
Authors: Fisher Leslee A. 
Published: February 2020

The purpose of this paper is to demonstrate how case study methodology, an advocacy practice and policy model (APPM), and new directions in feminist theory can be utilized to educate coaches about sexual misconduct. Case studies are useful for both research and teaching purposes because they provide a potential framework for analyses of “real-world” problems. The APPM provides guidance on moving from analysis to action; in particular, advocacy is about education, negotiation, and persuasion. Feminist theorists push us to consider how the embodied experiences of female athletes and feminine subjectivities can unsettle and disrupt normative assumptions about the way that sport should be conducted. The case of Larry Nassar is utilized because of the amount of reporting available to analyze; this includes female athlete survivor voices. Having coaches wrestle with such questions as (a) Do I know the definitions of sexual misconduct? (b) Do I understand the warning signs a female athlete might be displaying if she is being abused by significant other in sport? (c) When do I have to report abuse to authorities? and (d) Do I know how to intervene on the athlete’s behalf? is important if we are to increase the likelihood of creating systemic change.
Usefulness of data augmentation for visual field trend analyses in patients with glaucoma
Authors: Asaoka Ryo , Murata Hiroshi , Matsuura Masato , Fujino Yuri , Miki Atsuya , Tanito Masaki , Mizoue Shiro , Mori Kazuhiko , Suzuki Katsuyoshi , Yamashita Takehiro , Kashiwagi Kenji , Shoji Nobuyuki 
Published: February 2020

AimTo investigate the usefulness of data augmentation in visual field (VF) trend analyses in patients with glaucoma.MethodThis study included 6380 VFs from 638 eyes of 417 patients with open-angle glaucoma. Various affine transformations were applied to augment the VF data: (1) rotation, (2) scaling, (3) vertical and horizontal shift and (4) a combination of these different transformations. Using pointwise linear regression (PLR), the total deviation (TD) values of a patient’s 10th VF were predicted using TD values from shorter VF series (from first to third VFs (VF1–3) to first to ninth VFs (VF1–9)) with and without VF data augmentation, and the root mean squared error (RMSE) was calculated.ResultsWith PLR, mean RMSE without VF augmentation averaged from 3.95 (VF1–3) to 19.01 (VF1–9) dB. The RMSE was significantly improved by applying the different transformations: (1) rotation (from VF1–3 to VF1–7), (2) scaling (from VF1–3 to VF1–6), (3) vertical and horizontal shifts (from VF1–3 to VF1–4) and (iv) a combination of these (from VF1–3 to VF1–7). Progression rates in VF1–10 had better agreement with those in shorter VF series when a combination of affine transformation was applied. The differences in rates were between 1.9 (VF1–3) and 0.39 (VF1–9) dB if augmentation was used, which was significantly smaller than that observed when augmentation was not applied (from 2.6 with VF1–3 to 0.26 dB with VF1–9).ConclusionIt is useful to apply VF data augmentation techniques when predicting future VF progression in glaucoma using PLR, especially with short VF series.
Maternal and paternal exercise regulate offspring metabolic health and beta cell phenotype
Authors: Zheng Jia , Alves-Wagner Ana Barbara , Stanford Kristin I , Prince Noah B , So Kawai , Mul Joram D , Dirice Ercument , Hirshman Michael F , Kulkarni Rohit N , Goodyear Laurie J 
Published: February 2020

ObjectivePoor maternal and paternal environments increase the risk for obesity and diabetes in offspring, whereas maternal and paternal exercise in mice can improve offspring metabolic health. We determined the effects of combined maternal and paternal exercise on offspring health and the effects of parental exercise on offspring pancreas phenotype, a major tissue regulating glucose homeostasis.Research design and methodsBreeders were high fat fed and housed±running wheels before breeding (males) and before and during gestation (females). Offspring groups were: both parents sedentary (Sed); maternal exercise only (Mat Ex); paternal exercise only (Pat Ex); and maternal+paternal exercise (Mat+Pat Ex). Offspring were sedentary, chow fed, and studied at weaning, 12, 20 and 52 weeks.ResultsWhile there was no effect of parental exercise on glucose tolerance at younger ages, at 52 weeks, offspring of Mat Ex, Pat Ex and Mat+Pat Ex displayed lower glycemia and improved glucose tolerance. The greatest effects were in offspring from parents that both exercised (Mat+Pat Ex). Offspring from Mat Ex, Pat Ex, and Mat+Pat Ex had decreased beta cell size, whereas islet size and beta cell mass only decreased in Mat+Pat Ex offspring.ConclusionsMaternal and paternal exercise have additive effects to improve glucose tolerance in offspring as they age, accompanied by changes in the offspring endocrine pancreas. These findings have important implications for the prevention and treatment of type 2 diabetes.