bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the Effects of Proximal Humeral Internal Locking System (PHILOS) Alone and PHILOS Combined with Fibular Allograft in the Treatment of Neer Three‐ or Four‐part Proximal Humerus Fractures in the Elderly
Authors: Zhao Lei , Qi Yi‐min , Yang Lei , Wang Gang‐rui , Zheng Sheng‐nai , Wang Qiang , Liang Bin , Jiang Chun‐zhi 
Published: November 2019

ObjectiveTo compare and analyze the clinical outcomes of the proximal humeral internal locking system (PHILOS) alone and the PHILOS combined with fibular allograft in the treatment of Neer three‐ and four‐part proximal humerus fractures (PHF) in the elderly.MethodsFrom January 2014 to January 2018, a total of 42 elderly patients with Neer three‐ or four‐part PHF admitted to our hospital were randomly divided into observation group and control group, with 21 patients in each group. The observation group was treated with the PHILOS combined with fibular allograft. The control group was treated with the PHILOS alone. Perioperative parameters and fracture classification were recorded in the two groups. Function results were assessed by Visual Analog Scale (VAS), Constant‐Murley score (CMS), American Shoulder and Elbow Surgeons (ASES) score, and the Disability of Arm‐Shoulder‐Hand (DASH) score. Radiological results were evaluated using the neck‐shaft angle (NSA) and humeral head height (HHH), and complications were also recorded in each group.ResultsThere were no significant differences between the two groups in terms of preoperative status, age, gender, cause of trauma, fracture site, and fracture classification. The average follow‐up time was 12 months. At the last follow‐up, the VAS and DASH observation groups were lower than the control group, and there was significant difference between the two groups (P < 0.05). The CMS and ASES were higher in the observation group than the control group, and there was significant difference between the two groups (P < 0.05). The mean difference in the NSA and HHH were lower in the observation group than the control group, and there was a significant difference between the two groups (P < 0.05). There was one postoperative complication in the observation group, which was humeral head avascular necrosis (AVN). There were seven postoperative complications in the control group, including three cases of humeral head collapse and three cases of screw cutout and one case of humeral head AVN. The incidence of postoperative complications in the observation group was significantly lower than the control group (P < 0.05), there was a significant difference between the two groups.ConclusionsFor Neer three‐ or four‐part PHF in the elderly patients, PHILOS fixation with fibular allograft shows satisfactory short‐term results with respect to humeral head support and maintenance of reduction, and may reduce the incidence of complications associated with fixation using a PHILOS alone.
A quantitative cross‐sectional analysis of the melanin index in the skin of preterm newborns and its association with gestational age at birth
Authors: Silva Paola Conceição , Guimarães Rodney Nascimento , Souza Rayner Guilherme , Reis Zilma Silveira Nogueira 
Published: November 2019

AbstractBackgroundEstimation of gestational age (GA) is important to make timely decisions and provide appropriate neonatal care. Clinical maturity scales to estimate GA have used skin texture and color to assess maturity at birth facing situations of the uncertainty of pregnancy dating. The size and darkness of the areola around the nipple to grade skin characteristics are based on visual appearance. The melanin index (M‐Index) is an optical skin parameter related to the melanin content in the tissue. This study is aimed to associate the M‐Index of the skin with the GA.MethodsA cross‐sectional study evaluated 80 newborns at birth. A photometer device quantified the skin pigmentation on the areolae, forearms, and soles. Paired average differences of M‐Index were compared among the three body sites. The skin M‐Indexes were compared between subgroups of newborns until 34 weeks or with 34 and more.ResultsThe skin over the areola had the highest values of M‐Index compared with the forearm or sole areas (P < .001 for both). Infants with a GA between 34 and <37 weeks had higher M‐Index values over the areola than the group with a GA with 24 to <34 weeks: 41.7 (8.9) and 38.3 (10.5) median (IQR), P = .005.ConclusionsThe measurable M‐Index values have the potential to improve physical evaluation in assessing GA at birth.
Infections due to multidrug‐resistant organisms following heart transplantation: Epidemiology, microbiology, and outcomes
Authors: Bhatt Pinki J. , Ali Mohsin , Rana Meenakshi , Patel Gopi , Sullivan Timothy , Murphy Joseph , Pinney Sean , Anyanwu Anelechi , Huprikar Shirish , Taimur Sarah 
Published: November 2019

AbstractBackgroundInfections secondary to multidrug‐resistant organisms (MDRO) have emerged as a growing problem in solid organ transplantation (SOT). Most of the published data on MDRO infections in SOT pertains to abdominal organ transplantation and data specific to heart transplantation (HT) are limited.MethodsThis is a retrospective review of HT recipients at our institution from 2011 to 2016; with the aim to investigate the epidemiology, microbiologic spectrum, and outcomes in patients with post‐HT MDRO infections, classified as multidrug‐resistant (MDR), extensively drug‐resistant (XDR), and pandrug‐resistant (PDR) using standardized definitions.ResultsOf the 149 HT recipients, 82 episodes of bacterial infection were seen in 46 patients (31%) in the year following HT. Thirty (37%) were due to MDR pathogens and 13 (16%) were XDR. The most common gram‐negative MDR pathogens were extended‐spectrum beta‐lactamase (ESBL) Escherichia coli and Klebsiella pneumoniae; while XDR pathogens were most commonly Pseudomonas aeruginosa followed by carbapenem‐resistant Klebsiella pneumoniae. Majority of infection episodes were bloodstream (54, 66%) followed by pulmonary infection (20, 24%). Within a year after transplant, HT recipients with any bacterial infection had significantly higher mortality versus those without infection; and XDR infections were associated with a 26‐fold greater hazard of death on average compared to those without infection (adjusted HR, 26.1; 95% CI, 6.4‐107.0; P < .001). There were no PDR infections.ConclusionBacterial infections were a significant predictor of 1‐year post‐HT mortality, which was highest among those with XDR infections. This study highlights the burden of MDRO infections in HT recipients and identifies an area of future research.
Effect of Carbon Dioxide Recirculation and Pressure on Efficiency of the TIPS and ENEL Oxy-Coal Power Cycles
Authors: Khan Md. Moheiminul I. , Chowdhury Mehrin , Chowdhury A. S. M. Arifur Rahman , Aboud Jad , Love Norman 
Published: November 2019

Abstract
This paper presents the results of thermal efficiency of two coal based oxy-combustion thermodynamic cycles that are modeled using aspen plus. The objective of the present study is to perform a parametric analysis, investigating the effect of different recirculation ratios at different pressures on the efficiencies of the cycle named for the company, ENEL, and the thermo energy power system, TIPS, cycles using aspen plus® software. Variables include the flue gas recycle flow rate, the combustor temperature, and the operational pressure. Five recirculation ratios were investigated, ranging from 20% to 75%. It was determined that as the amount of recycled gas into the combustor increased, the thermal efficiency increased for both the TIPS and ENEL cycles. The highest thermal efficiency for TIPS is 37% and for ENEL is 38%, both occurring at a 75% recirculation ratio. After investigation, since combustion temperature and specific heat capacity decreases at higher recirculation ratios, the mass flow rate was the dominant factor that contributes to the increase in thermal efficiency of the cycle. At each recirculation ratio, the effect of pressure is also determined. For ENEL, the increase in cycle efficiency is 10% over the pressure range of 1–12 bar at a recirculation ratio of 20%, while the increase in cycle efficiency is only 1.5% at a higher recirculation ratio of 75%. For TIPS, the cycle efficiency increases by 4% at the recirculation ratio of 20% and increases by 3% at the recirculation ratio of 75% for a pressure range of 50–80 bar.
Optimal Design of Reaction Hydro Turbine Model Stay Vane by Vane Angle and Thickness Distribution
Authors: Shrestha Ujjwal , Park Jungwan , Choi Young-Do 
Published: November 2019

Abstract
Optimization is uprising technology in the engineering field, which enhance the performance of mechanical components. Likewise, upcoming turbomachinery designs need to be more efficient, cost-effective and easy manufacturing. Many optimization techniques have implemented for the development of efficient turbomachines. In this study, the optimization has mostly confined to the stay vane of reaction turbine like Francis, Pump Turbine etc. Stay vanes are mainly used to direct the flow towards guide vane and runner in the reaction type turbine (Francis, Pump Turbine). The three-dimensional flow field from the spiral casing is highly distorted, which causes secondary flow. However, the uniform flow field has maintained by stay vane. Due to steady flow field from stay vane, the performance of the runner has improved. Therefore, the better design of stay vane has been required for the improvement of the flow field around the runner passage. The design parameters of the stay vane are vane angle distribution and thickness distribution from leading edge to trailing edge. The vane angle distribution controls the stability of flow field direction and momentum towards the runner. Similarly, the thickness distribution will maintain the profile of the stay vane. The optimization of stay vane has improved turbine efficiency, flow uniformity, and pressure loss. The multi-objective genetic algorithm (MOGA) was selected for the optimization of stay vane because it satisfies all the objective functions without being dominated by any specific solution. MOGA is a more realistic approach to optimization. The validation test of performance is conducted to compare the result of experimental and numerical methods. The optimized stay vane has improved the flow uniformity around the stay vane.
Brownian Diffusion of Nano-Fibers: Application to Mobility Characterizations
Authors: Tian L. , Ahmadi G. , Tu J. Y. 
Published: November 2019

Abstract
In this study, the Brownian diffusion of elongated nano-fibers was investigated numerically. Motions of nano-fibers of different sizes and aspect ratios were resolved by solving the corresponding system of equations governing their coupled translational and rotational motions. The study allowed a close examination of the Brownian diffusion of nano-fibers with respect to the coupling of their translational and rotational motions and how the rotation affects the fibrous particle macroscopic diffusion properties. Particular attention was given to the rotational relaxation time in determining the isotropic and anisotropic diffusive properties of elongated particles. Theoretical and semi-empirical equations were developed to quantify the diffusion coefficients of nano-fibers. Orientation averaged mobility of the nanofiber, nanorod and non-spherical nano-agglomerates was examined by the newly developed Brownian diffusion model. The result was compared with the particle mobility by collision limited reaction rate theory, empirical models and the experimental measurements. The study led to the discovery of a surface dominated mobility for nanoparticles with Knudsen number greater than 5 (Kn &gt; 5). For particles in this range, all morphologies can be viewed as point collision and therefore the use of the equivalent surface mobility diameter was reasonably justified. Beyond this range when Kn &lt; 0.1, however, the study showed that the particle morphology starts to play an important role, and accuracy of the surface mobility approximation reduces as the Knudsen number decreases. The study opened up new approaches for studying fundamental diffusive processes of nano-particles of complex shapes which are numerous in natural environment.
Two Types of Nonlinear Pressure Waves in Bubbly Liquids Incorporating Viscosity and Thermal Conductivity
Authors: Kamei Takafumi , Kanagawa Tetsuya 
Published: November 2019

Abstract
The present study theoretically elucidates an effect of the viscosity and the thermal conductivity on the propagation process of finite amplitude disturbance in bubbly liquids by deriving two types of weakly nonlinear wave equations. Appropriate choices of a set of scaling relations of physical parameters characterizing waves, that is, the wavelength, incident wave frequency, propagation speed, yield the derivation systematically. From the combination of appropriate scaling relations and the method of multiple scales, we can derive the Korteweg–de Vries–Burgers equation for the low frequency long wave and the nonlinear Schrödinger equation for slowly varying envelope wave of the quasi-monochromatic short carrier wave. As a result, the incorporation of conservation equation of energy affects nonlinear, dispersion, and dissipation terms for both long and short waves. Especially, the viscosity and the thermal conductivity lead to change considerably the form of coefficient of dissipation term.
A Dynamic Time Filtering Technique for Hybrid RANS-LES Simulation of Non-Stationary Turbulent Flow
Authors: Jamal Tausif , Walters D. Keith 
Published: November 2019

Abstract
Unsteady turbulent wall bounded flows can produce complex flow physics including temporally varying mean pressure gradients, intermittent regions of high turbulence intensity, and interaction of different scales of motion. As a representative example, pulsating channel flow presents significant challenges for newly developed and existing turbulence models in computational fluid dynamics (CFD) simulations. The present study investigates the performance of the Dynamic Hybrid RANS-LES (DHRL) model with a newly proposed dynamic time filtering (DTF) technique, compared against an industry standard Reynolds-Averaged Navier-Stokes (RANS) model, Monotonically Integrated Large Eddy Simulation (MILES), and two conventional Hybrid RANS-LES (HRL) models. Model performance is evaluated based on comparison to previously documented Large Eddy Simulation (LES) results. Simulations are performed for a fully developed flow in a channel with time-periodic driving pressure gradient. Results highlight the relative merits of each model type and indicate that the use of a dynamic time filtering technique improves the accuracy of the DHRL model when compared to a static time filtering technique. A comprehensive evaluation of the results suggests that the DHRL-DTF method provides the most consistently accurate reproduction of the time-dependent mean flow characteristics for all models investigated.
Numerical Simulation and Vorticity Analysis of Cavitating Flow Around a Marine Propeller Behind the Hull
Authors: Long Yun , Han Chengzao , Ji Bin , Long Xinping , Zhang Zhirong 
Published: November 2019

Abstract
In this paper, the unsteady cavitating turbulent flow around a marine propeller behind the hull is simulated by the k-ω SST turbulence model coupled with the Zwart cavitation model. Three systematic refined structured meshes around the hull and propeller have been generated to study the predicted cavitation patterns and pressure fluctuations. Numerical results indicate that the predicted transient cavitating flow behind the hull wake, including sheet cavitation and tip vortex cavitation, shows quasi-periodic feature and agrees fairly well with the available experimental data. The deviations of pressure fluctuations between experimental data and numerical results are much small. With mesh refining, the cavitation region and the magnitudes of the calculated pressure fluctuations increase, while the differences between two adjacent sets of grids become smaller. In addition, the uncertainty of the thrust coefficient obtained by Factor of Safety method is significantly small. Further, the interaction between the cavitation and the vortex by the relative vorticity transport equation is illustrated. Results show that the magnitude of stretching term is obviously larger than the other three terms, and the dilatation term and the baroclinic term both have an important influence on the generation of vortices.
A Model for a Gas Column Oscillation Inside a Hole by Irradiating an Acoustic Wave
Authors: Furuya Yuki , Sanada Toshiyuki , Watanabe Masao 
Published: November 2019

Abstract
Wet cleaning methods using fluid are widely applied in many industrial fields. For a cleaning inside closed-end holes, it is first necessary to fill the holes to be cleaned with the liquid. However, in structures with small holes, it is difficult to discharge inside the gas due to surface tension. In our early studies, we have found that the discharging a gas inside a closed-end hole was promoted by an impingement of droplet train. And the pressure fluctuation near the gas-liquid interface due to droplet impingement was important.
In this study, we attempted the gas discharge from closed-end holes due to acoustic wave irradiation. First, we theoretically estimated the oscillation of the gas column inside the hole during acoustic wave irradiation. We modeled the natural frequency of the gas column using a spring-mass system. Then we experimentally measured the fluctuation of the gas-liquid interface for the evaluation of the model. In addition, we compared the gas discharge ratio with different frequency and pressure level. The fluctuation of gas-liquid interface and discharging the gas were observed with a high-speed video camera.
As results, the natural frequencies of a gas column were depending on the length of the gas column and the diameter of the hole. From the experiments, we confirmed that the acoustic wave certainly propagated into the hole, and the frequency of the irradiated acoustic wave and the experimentally obtained natural frequency were in good agreement except for extremely low gas discharge ratio condition. Moreover, we observed gas discharge process and found that the high gas discharge ratio were achieved using the acoustic wave close to natural frequency. From these results, we concluded that the assumption based on a spring-mass system is valid.
Numerical Study on the Flow Field Analysis and Optimization of Turbine in Supercritical Compressed Air Energy Storage
Authors: Wang Meng , Deng Jianqiang , He Yang , Chen Haisheng , Xu Yujie 
Published: November 2019

Abstract
Supercritical compressed air energy storage system requires high turbine efficiency over a wide working range at both the design-point and off-design point. The operating range of the turbine is often limited by the occurrence of flow instability, such as distinct vortex and load deterioration. In specific situations, the development of aerodynamic instabilities at low inlet pressure operating conditions can lead to lower turbine efficiency, even lead to turbine choke, limiting the wide operating range of the turbine. Specifically, the high-pressure stage turbine of the expander, namely the first stage turbine, will not only bears a sharp change of inlet pressure but also experiences the maximum and variable pressure drop. In this paper, Real Gas Property (RGP) file for supercritical air is used for simulations. The CFD method and RGP file are validated by the turbine in the NASA report. A detailed 3D CFD analysis is performed for the preliminary designed first stage turbine under variable inlet pressure. With the purpose of improving the aerodynamic performance of the first stage turbine under extreme working conditions, a series of simulations are conducted to examine the effects of the IGV parameters (i.e. different types of IGVs, the nozzle-impeller radial gap distance and the nozzle blade installation angle) and blade thickness, which led to the optimization in overall turbine stability. The results show that IGV TC-2P have good aerodynamic performance, and the matched rotor can achieve an isentropic efficiency of 80% under off-design working conditions. The optimal blade installation angle blade is 35°. And there exists an optimal nozzle-impeller radial gap distance Δr. The turbine efficiency obtains a maximum value at Δr = 5 mm. In all cases for blade thickness, the different configurations have a significant change in inlet total pressure of 4.5 MPa compared to the design pressure of 7 MPa. The maximum efficiency is reached at the ellipse ratio is 1:1 for Case-2. The results of the optimal IGV TC-2P performance optimization is essential to improve the isentropic efficiency at low inlet pressure.
Accuracy of the CRW Models for Prediction of the Deposition and Dispersion of Particles in Inhomogeneous Turbulent Channel Flows
Authors: Mofakham Amir A. , Ahmadi Goodarz 
Published: November 2019

Abstract
The accuracy of the continuous random walk (CRW) stochastic model for prediction of dispersion and deposition of suspended particles in inhomogeneous turbulent channel flows was explored. The Reynolds-averaged Navier-Stokes (RANS) equations in conjunction with the Reynolds Stress Transport model was used to evaluate the mean flow and RMS velocity fluctuation characteristics of a fully developed turbulent channel flow at shear Reynolds number of 219. Then, spherical particles with diameters ranging from 10 nm to 30 μm and dimensionless relaxation times of 10−4 to 50 (in wall units) were uniformly introduced into the channel and their trajectories were evaluated by using the equation of particle motion including the Stokes drag and Brownian excitation. The particle laden flow was assumed to be sufficiently dilute so that the particle-particle collisions and the effects of particles on the flow could be ignored. To incorporate the effects of turbulence velocity fluctuations on particle motions, first, the Conventional-CRW stochastic model, which was originally proposed for homogenous turbulent flows, was used. The particles were tracked for the duration of 10,000 wall units of time and the deposition of particles on the walls was evaluated. By conducting ensemble averaging, the steady-state concentration profiles and deposition velocity of the particles were calculated. Comparison of the predicted results with the direct numerical simulation (DNS) and experimental data suggests that the deposition velocity was overestimated. In addition, unrealistic accumulation of fluid-point particles in the near-wall regions, and overestimation of the turbophoresis effects on finite-size particles were also observed. The poor agreement of the concentration profiles and deposition velocities resulting from the conventional (homogenous flow) CRW model with the experimental and the DNS data pointed to the lack of accuracy of the Conventional-CRW model in generating instantaneous fluid velocity fluctuations seen by ultrafine and finite-size particles in inhomogeneous turbulent flows. Then, the normalized Langevin equation with a drift correction term that was suggested by Bocksell and Loth [1] was used as an improved CRW model for applications to inhomogeneous flows. The simulations for the same range of particle sizes were repeated and the corresponding concentration profiles and the deposition velocity were evaluated. It was shown that the improved CRW model led to a reasonable uniform concentration profile for the ultrafine particles and the predicted concentration profiles of finite-size particles quantitatively matched with the DNS data. In addition, the evaluated deposition velocities from the improved CRW model were also in a good agreement with the experimental data and empirical model predictions.