bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy of a patient‐specific 3D printed drill guide for placement of cervical transpedicular screws
Authors: Hamilton‐Bennett Sinead E. , Oxley Bill , Behr Sebastien
Published: October 2017

Objective

To develop a patient‐specific 3‐dimensional (3D) printed drill guide for placement of cervical transpedicular screws and to assess its accuracy.

Study design

Prospective case‐series.

Sample Population

Thirty‐two cervical pedicle screws (CPS) placed in 3 large breed dogs.

Methods

Computed tomographic (CT) data of the cervical vertebrae were exported to a medical image processing software and 3D virtual vertebral models were created for each vertebra. These models were processed in a computer aided design (CAD) software to determine the optimal trajectory and size of the CPS. Virtual drill guides were created for each patient, 3D‐printed, and used intraoperatively. Locking titanium screw heads were bonded with polymethylmethacrylate cement to stabilize affected vertebral segments. Postoperative CT was used to assess the radiological accuracy of CPS placement in each dog. For each screw, CAD files were analyzed to determine a screw‐diameter‐to‐pedicle‐width‐ratio (SDPWR) at the narrowest point of the pedicle.

Results

A total of 32 CPS were placed, measuring 3.5 mm (n = 20), 2.7 mm (n = 11), and 2.4 mm (n = 1) in diameter. The majority (29/32) of these screws were placed without evidence of vertebral canal breach (grade 0), whereas a vertebral canal breach <2 mm (grade 1) was detected in 3/32 screws. This outcome was achieved despite a mean SDPWR of 0.75 (range 0.58‐0.93).

Conclusion

The use of a 3D‐printed patient‐specific drill guide permitted accurate placement of 32 bicortical pedicle screws in the caudal cervical vertebrae of 3 dogs. This technique may improve clinical outcome through superior biomechanical properties of screws, reduced surgical time, and reduced morbidity. These results warrant evaluation of patient outcome in a larger population.
Manganese coprecipitation/adsorption behaviour and sludge volume ratios in chemical treatment systems for mine drainage: a review of the literature and a pilot‐scale experiment
Authors: Kim Duk‐Min , Kim Dong‐Kwan , Lee Sang‐Hwan
Published: October 2017

Manganese removal at lower pH and sludge volume in settling ponds are some of the major issues affecting chemical treatment systems for mine drainage. First, Fe and Al existing in mine drainage coprecipitate with and/or adsorb Mn. Eight chemical treatment facilities were reviewed from literature and a pilot‐scale experiment was also conducted in the Daedeok mine in South Korea. The Mn/(Fe + Al) ratio revealed a positive linear relationship with the lowest pH at discharge, and regression lines were generated. This relationship may be used to predict the pH required to remove Mn considering coprecipitation/adsorption. Second, the ratios of the generation rate of sludge to the required settling volume at five semi‐active treatment facilities were evaluated from literature. This ratio is referred to as the sludge‐settling volume ratio, which can be used as one of the factors in deciding between semi‐active and active treatment systems.
Relationship between Organizational Climate, Employee Psychological Empowerment, and Innovation in Market Research Firms in Kenya
Authors: Wangombe James , Yohannes Tecle H.
Published: October 2017

The purpose of the study was to find out the relationship between Organizational Climate (OC), Employee Psychological Empowerment (EPE) and innovation in Market and Social Research Firms (MSRFs) in Kenya. This was motivated by inconsistent empirical findings of the previous scholars on the effect of organizational climate on innovation. Besides, it was inspired by the omission of the employee psychological empowerment as intervening variable between OC and innovation. This study therefore, investigated the effect of OC on EPE and EPE on innovation. Further, direct effect of OC on innovation was also assessed. To address these objectives, this study used cross-sectional research design. The data was collected using a structured questionnaire and analyzed using Structural Equation Modelling (SEM). The study found the effect of training support on EPE and innovation was positive but insignificant while work place support on EPE had partial effect but insignificant effect on innovation. However, transformational leadership was found to be significant on both EPE and innovation. Further, the EPE had partial mediating effect between leadership and innovation. The findings offer more insights to the theorists of intrinsic motivation that intrinsic motivation taps on some organizational climate factors to promote innovation. The results could be helpful to human resources practitioners and policy makers when deciding on a mix of organizational climate factors to promote innovation in institutions. Consideration of multiple organizational factors as opposed to a single factor to enhance innovation at micro level in their work place is hinted.
The Clogging Behavior of a Vortex Pump: An Experimental Study on the Influence of Impeller Designs
Authors: Gerlach Angela , Perlitz Dorian , Lykholt-Ustrup Flemming , Jacobsen Christian Brix , Thamsen Paul Uwe
Published: October 2017

This paper analyzes the clogging behavior of a vortex pump with different impeller designs. The influence of blade outlet angle, blade number, and impeller diameter were tested. Non-woven textiles in different concentrations served as the clogging material. The results suggest that a smaller outlet blade angle, a higher blade number, and a larger impeller diameter allow pumping more textiles. Impellers that were capable of pumping more textiles, however, were less efficient. Overall, pumping textiles causes efficiency losses. However, this could not be only related to increased power consumption. Flow rates under clogging operation were close to the flow rates under clear water operation irrespective of the amount of clogging material and the impellers design. Further, in all tests clogging material accumulated at the suction mouth in the casing.
Effect of Baffles in Between Stages on Performance and Flow Characteristics of a Two-Stage Split Case Centrifugal Pump
Authors: Wang Yiyun , Pei Ji , Yuan Shouqi , Wang Wenjie
Published: October 2017

Two-stage split case centrifugal pumps play an important role in large flow rate and high lift water transfer situations. To investigate the influence of baffles in between stages on the performance and internal flow characteristics, the unsteady simulations for the prototype pump were carried out by solving the three-dimensional Reynolds-averaged Navier-Stokes equations with a shear stress transport (SST) turbulence model. The structured grids were generated for the whole flow passage. The calculated performance results were verified by the experimental measurements. The entropy production method based on numerical simulation was applied to analyze the distribution and mechanism of flow losses. The results show that the turbulence dissipation is the dominant flow loss, and the viscous dissipation can be neglected. The baffles can reduce the turbulence dissipation power obviously and can improve the hydraulic efficiency by maximum 5%, especially under QBEP and over-load conditions. The baffles have the greatest effect on the hydraulic losses in the double suction impeller., because they change the flow characteristics in the channels between the first stage impeller and the double suction impeller, affecting the inflow condition dramatically for the impeller. The study can give a reference to optimize the design of the two-stage split case centrifugal pump for high efficiency.
Evaluation of Effect of Viscosity on an Electrical Submersible Pump
Authors: Morrison Gerald , Yin Wenjie , Agarwal Rahul , Patil Abhay
Published: October 2017

Understanding and predicting the effect of viscosity change on an Electrical Submersible Pump (ESP) performance is of great significance to the oil and gas operators. The purpose of this research is to investigate the flow behavior inside a mixed flow type pump operating with fluids of different viscosities using Computational Fluid Dynamics (CFD) with the goal to establish additional terms for the pump affinity laws to scale pump performance including the effects of viscosity. Several sets of fluids of different viscosities and densities are simulated under various operating conditions. The effect of viscosity on the performance of the impeller and diffuser is discussed. Changes in the pump performance due to fluid viscosity are characterized using the dimensionless flow coefficient, head coefficient and rotational Reynolds number. The result, which can be regarded as the modified pump affinity laws for viscosity flows, was obtained based on the relationships between dimensionless coefficients. The modified affinity laws agreed well with the CFD results. Further study was conducted to validate the relationships using previously published test data for a semi axial pump design (Specific Speed, Ns: 3869) tested with fluid viscosity ranging from 1 cp to 1020 cp and in-house testing of a split vane impeller pump (Ns: 3027) and a helicoaxial pump (Ns: 5281) using 1cp and 5 cp viscosity fluid. The modified affinity laws accurately models the performance dependence upon viscosity. As with the standard affinity laws, a pump’s functional relationship varies with each pump design. Yet the modified affinity laws produce a single common curve for all operating conditions and viscosities for a specific pump.
Load Rejection Test and Numerical Prediction of Critical Load Case Scenarios for Pumped Storage Plant
Authors: Chen Sheng , Zhang Jian , Li Gaohui , Yu Xiaodong
Published: October 2017

A pumped storage plant (PSP) is by far the most cost effective and mature technology for energy storage at a large-scale, and therefore, this technology is rapidly being developed and deployed. A reversible pump turbine (RPT) is the vital component of a PSP, and whether a PSP can operate safely and stably mainly depends on the characteristics of the RPT. However, the existence of S-shaped characteristics of a RPT usually leads to severe water hammer and pressure pulsations during the transient processes of load rejection. Therefore, hydraulic transient analysis in a PSP is one of the most important issues for the prevention of undesirable pressure fluctuations in waterways. Theoretically, the most accurate method is to conduct on-site measurements of all possible load cases to obtain the extreme values of pressure. However, extreme operating conditions such as 2-stage load rejection pose serious threats to the safety of the water conveyance system, making it impossible to carry out field trials under such conditions. This paper gives the numerical prediction of extreme and critical load case scenarios from the simultaneous load rejection field test on a double unit of a PSP in China. The dynamic transient numerical model for load rejection of the PSP is developed by introducing the method of characteristics. The boundary conditions, such as the real adopted wicket gate closure law and parameters of the water conveyance system, are calibrated according to the field test data. Considering the large pressure pulsations in the PSP during load rejection, a proper pressure pulsations amendment is proposed as well. Eventually, the hydraulic behavior of the critical load cases are numerically investigated by the modified model. And the results are amended by the proposed pressure pulsations processing approach to predict whether the hydraulic parameters can satisfy the design criteria, which can ensure safe operation of the PSP in the future. The achievements of the study can serve as a reference for similar PSP projects.
Study on Slip Phenomenon of Pumps As Turbines in Different Working Conditions
Authors: Xiaohui Wang , Junhu Yang , Zhengting Xia
Published: October 2017

Slip phenomenon is known to strongly influence the performance of pump as turbine (PAT). It is of interest to investigate the influence of flow parameters on the slip factor and obtain the effective value of slip factor over the whole range of their working conditions.

In the present work, the slip phenomenon of PAT at different working condition was studied, slip factor was calculated in every point of the flow. Furthermore, the relative eddy within the impeller passage was evaluated and the hydraulic performance of PAT was analyzed.

The result shows that the slip factor decreases with the increasing flow rate, slip phenomenon induces additional hydraulic loss in impeller passage, it weakened in over-load region, as a consequence, hydraulic efficiency is relatively high. On the contrary, the slip phenomenon strengthened in part-load region, therefore, hydraulic efficiency of PAT is relatively low. It was observed that a relative eddy take place within the impeller passage, the eddy occurs near pressure side of blade at design-point condition, it motions to suction side at high discharge, and divides into two separated eddy at partial discharge condition. The relative eddy cause pressure fluctuate in PAT impeller, which affects the energy recovery of PAT.
The Aerodynamic Characteristics of the Pantograph When the Train Passes Through the Tunnel
Authors: Guo Dilong , Liu Wen , Song Junhao , Zhang Ye , Yang Guowei
Published: October 2017

The aerodynamic force acting on the pantograph by the airflow is obviously unsteady and has a certain vibration frequency and amplitude, while the high-speed train passes through the tunnel. In addition to the unsteady behavior in the open-air operation, the compressive and expansion waves in the tunnel will be generated due to the influence of the blocking ratio. The propagation of the compression and expansion waves in the tunnel will affect the pantograph pressure distribution and cause the pantograph stress state to change significantly, which affects the current characteristics of the pantograph. In this paper, the aerodynamic force of the pantograph is studied with the method of the IDDES combined with overset grid technique when high speed train passes through the tunnel. The results show that the aerodynamic force of the pantograph is subjected to violent oscillations when the pantograph passes through the tunnel, especially at the entrance of the tunnel, the exit of the tunnel and the expansion wave passing through the pantograph. The changes of the pantograph aerodynamic force can reach a maximum amplitude of 106%. When high-speed trains pass through tunnels at different speeds, the aerodynamic coefficients of the pantographs are roughly the same.
Verification and Validation of the Caelus Library: Incompressible Flow Solvers
Authors: Jemcov Aleksandar , Stephens Darrin W. , Sideroff Chris
Published: October 2017

Emphasis of this paper is on the validation and verification of the open source numerical library, Caelus, suitable for the simulation of problems in continuum physics. The focus of this work is the verification and validation of problems in fluid mechanics. Several test cases including Couette and Kovasznay flows are used in verification of the steady state solver for incompressible flows. In addition, flat plate boundary layer, flow through a tee-junction and triangular lid-driven cavity are used in the validation part of the work. In all cases excellent agreement was found between the numerical, analytical and experimental results.
Development of Optical Techniques for Multiphase Flows Characterization
Authors: Lamadie Fabrice , Charton Sophie , de Langlard Mathieu , Ouattara Mariam , Sentis Matthias P. L. , Debayle Johan , Onofri Fabrice R. A.
Published: October 2017

Optical methods for investigating multiphase flows are reviewed and discussed in the scope of the development of apparatus convenient for nuclear fuel reprocessing. Indeed, the various processes implemented (e.g. leaching, solvent extraction, filtration, crystallization, etc.) involve either liquid/gas, liquid/liquid and/or liquid/solid flows. Besides the adaptation of classical techniques, such as PIV and image processing, that have been used to quantify velocity fields and particles size distribution in flat-tank reactors, a typical design used in the nuclear industry to mitigate criticality issues, more innovating techniques are currently developed. The latter open the way to the measurement of less usual, although equally important measurements, such as the droplet composition in a liquid-liquid extraction column, and mass transfer rate in multiphase flows.
Experimental and Computational Investigation of an Air Core Inside a Milling Circuit Hydroclone
Authors: Kadambi J. R. , Shingote C. , Ke R. , Tian Z. , Furlan J. , Visintainer R.
Published: October 2017

Hydrocyclone separators are widely used in various industrial applications in the oil and mining industries to sort, classify and separate solid particles or liquid droplets within liquid suspensions. Often, studies in the literature have investigated idealized and simplified geometries, which are also typically scaled down to very small sizes. In this study, the two phase flow system inside a transparent acyclic model with actual milling circuit cyclone hydraulics was investigated computationally and experimentally. The diameter and height of the hydrocyclone are 12.7 cm and 94 cm, respectively. In many industrial applications, a single phase flow system in a hydrocyclone is a rarity, since nearly all cyclones have an underflow which is open to atmosphere, and therefore an air core is present along the central axis. In this study, the flow field with an air core present has been investigated. The computational modelling was conducted using Star CCM+, a commercial Computational Fluid Dynamics (CFD) software package. Large Eddy Simulation (LES) and the Volume of Fluid multiphase model was used. Additionally, the computational studies also focused on the prediction of the dimensions of the air core, which were measured experimentally. The tests were conducted in the Reynolds number range of 20,000–150,000 and 9000–67,800 for the water and NaI solution respectively. The model hydrocyclone was made of optically transparent acrylic plastic with flat, smooth outer surfaces so that there were no reflections, distortions, or obstructions. Refractive index matching, to minimize refraction effects, between the test fluid and acrylic test piece was achieved using a test liquid of sodium iodide aqueous solution (63.3% NaI by weight). Images of the flow field with the air core were taken using a Canon DSLR camera. A comparison between the experimental data and the computational results were made in the r-z plane. The experimental results and the computational results will be discussed in this paper.
Confinement Effects on Effective Slip of Patterned Surfaces
Authors: Kumar Avinash , Datta Subhra , Kalyanasundaram Dinesh
Published: October 2017

Even Newtonian liquids are now known to slip past suitably engineered surfaces, such as those exhibiting super-hydrophobicity. Through friction reduction, such surfaces have potential to significantly reduce the required the motive power to drive confined flows. Studies of unconfined shear flows over such surfaces have revealed that patterned slipping surfaces are intrinsically inferior to the less realizable uniformly slipping surfaces in terms of the fluid slip velocity generated per unit pattern-averaged shear stress. In this study, a spectrally accurate semianalytical approach is used to assess the friction-reduction performance of several alternate ways of confining the flow over a patterned surface. Fluid permeates by pressure differential through a channel with plate-like walls. One of the plates forming the channel is kept fixed throughout the study to have a sinusoidal slip pattern, while the second plate can be non-slipping, uniformly slipping and patterned identically to the first surface. The gap between the plates, the degree of slip and pattern waveform parameters can be varied between limits not restricted by the model. Significantly different behaviours in permeability and the effective degree of slip of the first plate arise from the differences in patterning on the second plate.
Multiphase Flow Analysis for Air-Water Bubbly Flow in a Multiphase Pump
Authors: Suh Jun-Won , Choi Young-Seok , Kim Jin-Hyuk , Lee Kyoung-Yong , Joo Won-Gu
Published: October 2017

Owing to the exhaustion of onshore resources, the development of resources has been expanded to the deep subsea. As the necessity of offshore plants is steadily increasing, there is an increasing interest in studying multiphase transportation technology. Multiphase pumps differ from single phase pumps in many ways, including performance evaluation, internal flow characteristics, and complex design methods. The primary issue of multiphase flow transport technology is that the characteristics of the internal flow change according to the gas volume fraction (GVF). Many theoretical and experimental analyses have been conducted to understand the mechanism of the internal flow field in multiphase pumps. As advanced computational fluid dynamics (CFD) based on the three-dimensional Reynolds-averaged Navier-Stokes (RANS) equations have become reliable tools, numerical analyses accompanied by experimental research have been applied to investigate the hydraulic performance and internal flow field of multiphase pumps. A number of studies have been conducted to investigate these phenomena. However, the understanding of the detailed mechanisms of phase separation and the forces that occur in the internal flow is not completely clear. This study aimed to establish a multiphase flow analysis method with high reliability when the internal flow of the multiphase pump is bubbly flow. To ensure the reliability of the numerical analysis, the numerical results were compared with the experimental data. Additionally, to analyze the detailed dynamic flow phenomena in the multiphase pump, the effects of various interphase forces acting between the liquid and gas phase and the particle diameter of the gas phase on the hydraulic performance were investigated.
Effective Particle Size Representation for Erosion Wear in Centrifugal Pump Casings
Authors: Pagalthivarthi Krishnan V. , Furlan John M. , Visintainer Robert J.
Published: October 2017

For the purpose of Computational Fluid Dynamic (CFD) simulations, the broad particle size distribution (PSD) encountered in industrial slurries is classified into a discrete number of size classes. Since mono-size simulations consume much less computational time, especially in 3D simulations, it would be advantageous to determine an equivalent single particle size representation which yields the same wear distribution predictions as the multi-size simulations. This work extends the previous two-dimensional study [1], which was for a specific PSD slurry flow through three selected pumps, to determine an effective equivalent mono-size representation. The current study covers two-dimensional simulations over a wide range of pumps of varying sizes (40 pumps), 2 inlet concentrations and 4 different particle size distributions. Comparison is made between the multi-size wear prediction and different possible representative mono-size particle wear predictions. In addition, a comparison of multi-size and different mono-size results using three dimensional simulations is also shown for a typical slurry pump as a sample case to highlight that the conclusions drawn for two dimensional simulation could hold good for three dimensional simulations as well. It is observed that by using a mono-size equivalent, the computation time is 20–25% of the computation time for multi-size (6-particle) simulation.
Axial Thrust Prediction for a Multi-Stage Centrifugal Pump
Authors: Bruurs K. A. J. , van Esch B. P. M. , van der Schoot M. S. , van der Zijden E. J. J.
Published: October 2017

The prediction of axial thrust for centrifugal pumps has been an important topic for many years. This is especially the case for multi-stage pumps with opposed or inline impellers, as the correct selection of balancing device(s) and bearings depends highly on the accuracy of the calculated thrust.

Up till now, many investigations regarding axial thrust have focused on fully analytical or (semi-)empirical relations while others have tried to predict the axial thrust using CFD simulations. Full analytical or empirical methods tend to give poor results or need tuning for each specific pump, while the full CFD methods are costly in both setup time and computer resources.

This paper presents a hybrid method to calculate the axial thrust of a multi-stage pump with an inline impeller design. The hybrid method combines analytical methods and CFD to reduce the required setup time and computation costs. The CFD calculation of the main flow is used as a boundary condition for the semi-empirical models for the side chambers and the inter-stage seals, such that these tight regions can be excluded from the CFD calculation.

To verify and validate the hybrid method, results are compared with measurements and with full CFD calculations that include the side chambers and seals. These results show that the hybrid method and the full CFD method give comparable results, but there is still some difference with the measurements.
Simplified Transient Numerical Model of a Supersonic Jet Impacting a Substrate
Authors: Xu Sichang , Pomerleau-Perron Patrick , Rankin Gary W.
Published: October 2017

The transient flow field near the surface of a substrate impacted by a pulsating supersonic jet emerging from a long tube is investigated using a simplified axially symmetric numerical approach. In the system being modeled, the pulses are created using a rotary valve located at the tube entrance. This flow situation approximates the conditions existing in the Shock-Induced Cold Spray process for coating surfaces with metallic particles. Previous numerical studies of transient supersonic jets either focused on jets emerging from orifices or did not give details of the complex supersonic flow field in the jet impact region. The current approximate numerical method considers the flow within the long tube and in the jet impact region. The procedure involves two stages. The upstream pressure variation with time is first determined using a one-dimensional compressible flow approximation of the entire tube and rotary valve arrangement. The resulting pressure versus time curve serves as the transient inlet boundary condition for an axially symmetric computational fluid dynamic solution of the flow through the tube and region of jet impact on the substrate. The numerical solutions of substrate pressure on the jet centerline versus time are compared with available experimental results and predict certain general features of the substrate pressure traces. Although the simplified model is only in fair agreement with some aspects of the experimental curves, it is shown to be useful in explaining certain peculiar flow features. With the aid of the numerical solution, an explanation for the movement and instability of the bow shock wave which forms ahead of the substrate is described.
A Unified Homogenous Multiphase CFD Model for Cavitation
Authors: Kinzel Michael P. , Lindau Jules W. , Kunz Robert F.
Published: October 2017

The present paper aims to close the gap on the understanding of cavitation model performance with respect to their inherent empirical constants. We first unify several cavitation models, providing a consistent framework for model comparison. Analytical methods are developed to directly compare cavitation models to the Rayleigh Plesset equation. The process is used to (1) develop a method to compare and equivocate models analytically, (2) develop a method to directly assess changes in the cavitation model with respect to bubble dynamics, and (3) provide insight into model improvement. The results identify general physical modeling issues and show that, if the empirical constants are correctly adjusted, the cavitation models yield similar results.
Erratum: “A Hydrofoil Configuration for Wind Powered Energy Ship Applications” [ASME 2017 Fluids Engineering Division Summer Meeting, Volume 1B, Symposia: Fluid Measurement and Instrumentation; Fluid Dynamics of Wind Energy; Renewable and Sustainable Energy Conversion; Energy and Process Engineering; Microfluidics and Nanofluidics; Development and Applications in Computational Fluid Dynamics; DNS/LES and Hybrid RANS/LES Methods, Waikoloa, Hawaii, USA, July 30–August 3, 2017, Conference Sponsors: Fluids Engineering Division, ISBN: 978-0-7918-5805-9, Copyright © 2017 by ASME. Paper No. FEDSM2017-69402, pp. V01BT07A003; 10 pages; doi:10.1115/FEDSM2017-69402]
Authors: Woeste Jacob T. , Turner Mark G. , Saxer Nicolas
Published: October 2017

This erratum corrects errors that appeared in the paper “A Hydrofoil Configuration for Wind Powered Energy Ship Applications” which was published in Proceedings of the ASME 2017 Fluids Engineering Division Summer Meeting, Volume 1B, Symposia: Fluid Measurement and Instrumentation; Fluid Dynamics of Wind Energy; Renewable and Sustainable Energy Conversion; Energy and Process Engineering; Microfluidics and Nanofluidics; Development and Applications in Computational Fluid Dynamics; DNS/LES and Hybrid RANS/LES Methods, V01BT07A003, July 2017, FEDSM2017-69402, doi: 10.1115/FEDSM2017-69402.
Comparison of Turbulent Jets Issuing From Various Sharp Contoured Nozzles
Authors: Aleyasin Seyed Sobhan , Fathi Nima , Tachie Mark Francis , Koupriyanov Mikhail
Published: October 2017

An experimental study was conducted to investigate nozzle geometry effects on mixing characteristics and turbulent transport phenomena in the near and intermediate regions of free jets issuing from modified contoured nozzles (contoured nozzle with a sharp linear contraction). The cross-sections examined were round, square, equilateral triangle as well as ellipse and rectangle with aspect ratio of 2. For each nozzle shape, detailed velocity measurements were made using particle image velocimetry at a Reynolds number of 10000. It was observed that noncircular jets have shorter potential cores than their round counterparts and their lengths are comparable with those of orifice jets. In addition, the spread and decay rates and the levels of turbulence intensities are the highest in the jets issuing from the elliptic and rectangular nozzles, implying enhanced mixing in these jets. The results from the swirling strength analysis revealed that the rotational motions induced by vortices within the minor planes of the elliptic and rectangular jets are more intense than those observed in the other jets. Furthermore the obtained data indicate distinctly different flow characteristics in the major and minor planes of elliptic, rectangular and triangular jets due to their asymmetric shapes. The size of turbulence structures in all the jets studied increases with streamwise distance and the elliptic and rectangular jets contain the largest structures.
Computational Fluid Dynamics Analysis of Blast Wave Interaction With Head and Helmet
Authors: Sarvghad-Moghaddam Hesam , Eslaminejad Ashkan , Hosseini Nassibeh , Ziejewski Mariusz , Karami Ghodrat
Published: October 2017

Blast waves are generated upon release of a large amount of energy in few milliseconds. Upon release, these high pressure waves propagate rapidly and interact with human head and lead to severe traumatic brain injury (TBI). Understanding the mechanics of blast flow would allow us to develop effective tools to protect the head against these shockwaves. Military helmets are known as the most effective tool for protecting the soldier’s head against blast threats. However, due to the complicated nature of the shockwave development and propagation, as well as its interaction with head and helmet, the efficiency of helmets is still in question. The major problem with using helmets under blast loading is the entrapment of blast shockwaves inside the helmet gap and its reflection from the interior of the helmet’s shell. Moreover, development of an amplified pressure region at the opposite side of the incoming blast waves, referred to as the underwash effect of helmets has raised some concerns. To this end, we performed a computational fluid dynamics (CFD) analysis to better understand the mechanism of the blast shockwave interaction with head, as well as the effect of the helmet on the alteration of flow mechanics. The compressible, turbulent blast flow was simulated in ANSYS CFX by releasing the air from a high-pressure domain into the low-pressure one (at ambient pressure). The un/protected heads were exposed to an identical blast overpressure of 520 kPa in a frontal open blast scenario. Pressure contours and velocity profiles were recorded at several time instances for both unprotected and helmeted heads. Our primary results revealed that the change of the flow momentum inside the helmet gap, the reunion of the blast flow inside the gap as well as the development of adverse pressure gradient (and hence recirculating flow region) at the rear side of the head are the major reasons leading to this adverse phenomenon.
A Flow Regime Map for Gas Jets
Authors: Fronzeo Melissa A. , Kinzel Michael , Lindau Jules
Published: October 2017

The dynamics of gas jets expelled into liquid are investigated utilizing Computational Fluid Dynamics (CFD). Results are analyzed with respect to changes in external liquid velocity and mass flow rate of the gaseous jet. In order categorize the complicated nature of the gas-fluid interactions coupled with the many physical dependencies, a flow-regime map is created. The majority of the regimes result in the formation of gaseous cavities encasing the jet, of which forms several cavity types. The internal flow structure of the categorized regimes are then studied with respect to the jet interactions with surrounding liquid and formed cavities. The results show major regions of recirculation and that the jet acts as a confined jet.
Numerical Analysis on the Impact of Inter-Stage Flow Addition in a High-Pressure Steam Turbine
Authors: Kang Soo Young , Lee Jeong Jin , Kim Tong Seop , Park Seong Jin , Hong Gi Won
Published: October 2017

This paper presents the analysis results of the fluid dynamic characteristics when steam is supplied through an overload valve to the second and third stages of an ultra-supercritical (USC) high-pressure turbine. Firstly, a single-passage computational analysis by using a simple model of an admission flow path, and a single passage for the second and third stages of the USC high-pressure turbine was performed. Computational analysis was conducted to determine the fluid dynamic characteristics exhibited when the second-stage outlet flow, that is, the main flow between the second-stage outlet and third-stage inlet, and the admission flow are being mixed. The mixing causes complex flow phenomena such as swirl, and the velocity vector of the main flow changes. This, in turn, causes a pressure drop between the second-stage outlet and third-stage inlet, potentially affecting the performance of the turbine. The actual flow in the overload valve is supplied through the admission flow path, which has the shape of a casing circumferentially surrounding the turbine, after passing through the valve and flowing in two directions perpendicular to the turbine axis. This necessitates full-passage computational analyses of the entire turbine and the flow paths of the overload valve. To achieve this, we implemented a full 3-D geometric modeling of the admission flow path, and conducted full-passage computational analyses of the fluid dynamic characteristics of all the flow paths including those of the second and third stages of the USC high-pressure turbine, focusing on the pressure drop occurring in the flow path of the overload valve. Furthermore, the results by the single and full-passage computational analyses were compared and the effects of two different methodological approaches on the results of the computational analysis were analyzed.
Synergism of Beauveria bassiana and Phytoseiulus persimilis in control of Tetranychus urticae on bean plants
Authors: Ullah Mohammad Shaef , Lim Un Taek
Published: October 2017

Tetranychus urticae Koch (Acari: Tetranychidae) causes severe damage in both greenhouse and field crops. Previous studies have found that a phytoseiid predatory mite, Phytoseiulus persimilis Athias-Henriot, and an entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin, are both potential candidates for the control of this pest and have shown varying degrees of success. We assessed the compatibility of these two biological control agents for control of T. urticae on potted bean plants, examining the following treatments: i) a low release rate of P. persimilis (10 prey:1 predator), ii) a high release rate of P. persimilis (5:1), iii) a single application of B. bassiana (1 × 108 spore/ml), iv) a single application of B. bassiana after application of the low release rate of P. persimilis, and v) a non-treatment control (no application of either B. bassiana or P. persimilis). A single application of B. bassiana reduced the egg and adult populations of T. urticae initially, but mite populations rebounded again after few days. Phytoseiulus persimilis at the high release rate eliminated the pest population completely, while the low release rate failed to control spider mites. The combined application of B. bassiana and low release rate of P. persimilis also successfully controlled T. urticae population (p < 0.001), with lowest corrected leaf damage (1.5%).
Acoustic speech analysis of patients with decompensated heart failure: A pilot study
Authors: Murton Olivia M. , Hillman Robert E. , Mehta Daryush D. , Semigran Marc , Daher Maureen , Cunningham Thomas , Verkouw Karla , Tabtabai Sara , Steiner Johannes , Dec G. William , Ausiello Dennis
Published: October 2017

This pilot study used acoustic speech analysis to monitor patients with heart failure (HF), which is characterized by increased intracardiac filling pressures and peripheral edema. HF-related edema in the vocal folds and lungs is hypothesized to affect phonation and speech respiration. Acoustic measures of vocal perturbation and speech breathing characteristics were computed from sustained vowels and speech passages recorded daily from ten patients with HF undergoing inpatient diuretic treatment. After treatment, patients displayed a higher proportion of automatically identified creaky voice, increased fundamental frequency, and decreased cepstral peak prominence variation, suggesting that speech biomarkers can be early indicators of HF.
Fast decomposition of two ultrasound longitudinal waves in cancellous bone using a phase rotation parameter for bone quality assessment: Simulation study
Authors: Taki Hirofumi , Nagatani Yoshiki , Matsukawa Mami , Kanai Hiroshi , Izumi Shin-Ichi
Published: October 2017

Ultrasound signals that pass through cancellous bone may be considered to consist of two longitudinal waves, which are called fast and slow waves. Accurate decomposition of these fast and slow waves is considered to be highly beneficial in determination of the characteristics of cancellous bone. In the present study, a fast decomposition method using a wave transfer function with a phase rotation parameter was applied to received signals that have passed through bovine bone specimens with various bone volume to total volume (BV/TV) ratios in a simulation study, where the elastic finite-difference time-domain method is used and the ultrasound wave propagated parallel to the bone axes. The proposed method succeeded to decompose both fast and slow waves accurately; the normalized residual intensity was less than −19.5 dB when the specimen thickness ranged from 4 to 7 mm and the BV/TV value ranged from 0.144 to 0.226. There was a strong relationship between the phase rotation value and the BV/TV value. The ratio of the peak envelope amplitude of the decomposed fast wave to that of the slow wave increased monotonically with increasing BV/TV ratio, indicating the high performance of the proposed method in estimation of the BV/TV value in cancellous bone.
Moving Forward: Academia, Industry, and Partnerships
Authors: Pascoe David D. , Moore Timothy E.
Published: October 2017

The decline in federal research grant funding and incentive-based budget models to support a university’s mission has necessitated a paradigm shift in the pursuit of available sources of funding. Programs built around federal funding are once again pursuing funding opportunities from industry. Universities are reevaluating their research funding models and career expectations (tenure, promotion) that support a researcher, laboratories, and a defined research agenda. Kinesiology departments are in a strong position to pursue industry funding for fitness, sports, and performance-related research. While grant funding focuses on empirical data-driven research, industry looks for product exposure, validation (empirical data to support claims), and commercialization. Industry partnerships can provide funding in supporting research, developing sponsor-named facilities that benefit both parties. With these cooperative efforts come some unique challenges (financial, proprietary, data interpretation, etc.) that must be addressed.
Campus-Community Partnerships in Health and Wellness
Authors: Wood Ralph , Hebert Edward , Wirth Chris , Venezia Ali , Welch Shelly , Carruth Ann
Published: October 2017

Successful campus-community partnerships provide universities enhanced visibility in the community, and offer university students opportunities to engage in real-world educational experiences through service learning and internships. In addition, the participating community agency/program benefits from an infusion of ambitious students that can help the agency/program further its mission, and increase its visibility and reach. Within the areas of health promotion and wellness, campus-community partnerships have become an essential component in the delivery of prevention services and the development of public health infrastructure. The purpose of this paper is to share the experiences of two universities in their development of campus-community partnerships in the areas of health and wellness.
Internship Management, Placement, and On-Site Visits in Kinesiology
Authors: Hebert Edward , Wood Ralph , Jenkins Jayne M. , Robison Charles E.
Published: October 2017

Internship experiences are currently embedded in a multitude of academic programs to provide students a more seamless transition from university to the professional setting. Research in a variety of academic fields (e.g., business, sport marketing, public health) reveals that internships enhance students’ professional knowledge and skills as well as increase opportunities for employment. Students studying kinesiology intend to enter a variety of professions (e.g., preprofessional, fitness development, physical education teaching), and departments frequently offer students multiple opportunities to engage in field-based learning experiences (FBLEs). As kinesiology programs have evolved to provide several degree programs and grown in the number of students serviced, challenges in managing the internship program have emerged. The purpose of this paper is to share the experiences of three university kinesiology departments in regard to internship management, placement, and site visits.
College Students' Motivations to Attend Group Fitness Classes: An Exploratory Investigation
Authors: Boren Shaun
Published: October 2017

This study investigated college students' various motivations to select from a comprehensive range of group fitness class (GFC) offerings at a university. Multivariate analysis of variance revealed a significant difference in motivations to exercise based on the GFC a participant was attending most often (primary GFC, p < .01). A post hoc test determined that Health Pressures was the only motivation subscale of 14 total subscales to significantly contribute to the main effect ( p < .003). However, the findings suggested that primary GFC can explain variation in motivations to exercise. This result evidences applicability of the self-determination theory between smaller categories of physical activity than previously tested. Future research should replicate the study at larger, more diverse institutions to explore additional factors affecting motivations to exercise. Practitioners can use this study to inform the design and advertising of GFCs.
The scaffolding protein Cnk binds to the receptor tyrosine kinase Alk to promote visceral founder cell specification in
Drosophila
Authors: Wolfstetter Georg , Pfeifer Kathrin , van Dijk Jesper R. , Hugosson Fredrik , Lu Xiangyi , Palmer Ruth H.
Published: October 2017

Alk signaling in the developing
Drosophila
visceral mesoderm requires the scaffolding protein Cnk and its binding partner Ave.
Papers of note in
Science
358
(6361)
Authors: VanHook Annalisa M.
Published: October 2017

This week’s articles highlight the role of adrenergic nerves in cancer growth; natural polyreactive antibodies that recognize gut microbiota; and structural insights into mTORC1 and D4 dopamine receptor signaling.
Papers of note in
Nature
550
(7676)
Authors: VanHook Annalisa M.
Published: October 2017

This week’s articles identify a mechanism that establishes the senescence-associated secretory phenotype and reveal details about the gating of TRPML channels.
Impact of Rifabutin or Rifampin on Bedaquiline Safety, Tolerability, and Pharmacokinetics Assessed in a Randomized Clinical Trial with Healthy Adult Volunteers
Authors: Healan Amanda M. , Griffiss J. McLeod , Proskin Howard M. , O'Riordan Mary Ann , Gray Wesley A. , Salata Robert A. , Blumer Jeffrey L.
Published: October 2017

Bedaquiline is a diarylquinoline that specifically inhibits mycobacterial ATP synthase. Bedaquiline has been used to effectively treat tuberculosis (TB) caused by drug-susceptible and drug-resistant
Mycobacterium tuberculosis
. Rifamycins are a cornerstone of combination drug regimens for the treatment of TB. This phase 1, open-label, randomized, controlled trial evaluated the effect of steady-state dosing of rifabutin or rifampin on the safety, tolerability, and pharmacokinetics of bedaquiline given as a single dose. Thirty-three healthy subjects were enrolled to receive a 400-mg single oral dose of bedaquiline at two time points, on study days 1 and 29. Subjects were randomly assigned to once daily oral doses of rifabutin (300 mg/day,
n
= 17) or rifampin (600 mg/day,
n
= 16) during period 2 from days 20 to 41. Serial blood sampling for bedaquiline measurement occurred on days 1 and 29 through 336 h after bedaquiline administration. The day 29 bedaquiline pharmacokinetic parameter estimates were compared to the corresponding day 1 estimates for each rifamycin group. Steady-state rifampin reduced bedaquiline AUC
0–336
approximately 45%, from 47.69 h·μg/ml in period 1 to 26.33 h·μg/ml in period 2. Bedaquiline apparent clearance accelerated 24% in rifampin-treated subjects from 6.59 liters/h in period 1 to 8.19 liters/h in period 2. Steady-state rifabutin resulted in little quantitative impact on bedaquiline exposure but was associated with grade 3 and 4 adverse events before and after the day 29 bedaquiline dose. Dosage adjustments may therefore be necessary to ensure that bedaquiline plasma concentrations reach therapeutic levels safely when combining bedaquiline and rifamycins in TB treatment regimens. (This single-site, randomized, open-label, prospective study in healthy adult volunteers was registered at Clinicaltrials.gov under registration no. NCT01341184.)