bluuebunny/crossref_metadata_2025_split huggingface dataset:
Situational analysis of lymphatic filariasis morbidity in Ahanta West District of Ghana
Authors: Stanton Michelle C. , Best Abigail , Cliffe Matthew , Kelly‐Hope Louise , Biritwum Nana‐Kwadwo , Batsa Linda , Debrah Alex 
Published: November 2015

AbstractObjectivesSituational analysis of lymphatic filariasis (LF) morbidity and its management in Ahanta West, Ghana, to identify potential barrier to healthcare for LF patients.MethodsLymphoedema and hydrocoele patients were identified by community health workers from a subset of villages, and were interviewed and participated in focus group discussions to determine their attitudes and practices towards managing their morbidity, and their perceived barriers to accessing care. Local health professionals were also interviewed to obtain their views on the availability of morbidity management services in the district.ResultsSixty‐two patients (34 lymphoedema and 28 hydrocoeles) and 13 local health professionals were included in the study. Lymphoedema patients predominantly self‐managed their conditions, which included washing with soap and water (61.8%), and exercising the affected area (52.9%). Almost 65% of patients had sought medical assistance at some stage, but support was generally limited to receiving tablets (91%). Local health professionals reported rarely seeing lymphoedema patients, citing stigma and lack of provisions to assist patients as a reason for this. Almost half of hydrocoele patients (44%) chose not to seek medical assistance despite the negative impact it had on their lives. Whilst surgery itself is free with national health insurance, 63% those who had not sought treatment stated that indirect costs of surgery (travel costs, loss of earnings, etc.) were the most prohibitive factor to seeking treatment.ConclusionsThe information obtained from this study should now be used to guide future morbidity strategies in building a stronger relationship between the local health services and LF patients, to ultimately improve patients' physical, psychological and economic wellbeing.
A Carbohydrate Sulfotransferase‐6 (CHST6) gene mutation is associated with Macular Corneal Dystrophy in Labrador Retrievers
Authors: Tetas Pont Roser , Downs Louise , Pettitt Louise , Busse Claudia , Mellersh Cathryn S. 
Published: November 2015

AbstractPurposeTo locate and identify variants associated with macular corneal dystrophy (MCD) in Labrador Retriever (LR) dogs, in the candidate gene carbohydrate sulfotransferase‐6 (CHST6).MethodsThe single coding exon of canine CHST6 was sequenced in one affected LR with MCD and one control LR clinically clear of ocular disease. A further 71 control LR with unknown clinical status were sequenced for the putative causal variant in CHST6. A TaqMan SNP genotyping assay was developed and used to screen an additional 84 dogs (five affected LR and 79 clinically clear LR). Finally, the variant was screened in a third cohort of 89 unrelated LR with unknown clinical status to estimate its allele frequency in the population of LR in the United Kingdom.ResultsA single nucleotide polymorphism (SNP) was identified within the coding exon of CHST6, resulting in a missense mutation (c.814C>A, p.R272S). All six LR affected with MCD were homozygous for the mutant allele, while 140/151 control LR were homozygous for the wild‐type allele and 11/151 were heterozygous for the mutation, indicating an association with MCD (P < 10−5). The mutant allele was present in the unrelated LR cohort at a frequency of 0.017, suggesting carrier and affection rates of 3.3% and 0.028%, respectively.ConclusionsA missense mutation in the CHST6 gene is strongly associated with autosomal recessive MCD in the LR.
Electrical effects of stem cell transplantation for ischaemic cardiomyopathy: friend or foe?
Authors: Mount Seth , Davis Darryl R. 
Published: November 2015

AbstractDespite advances in other realms of cardiac care, the mortality attributable to ischaemic cardiomyopathy has only marginally decreased over the last 10 years. These findings highlight the growing realization that current pharmacological and device therapies rarely reverse disease progression and rationalize a focus on novel means to reverse, repair and re‐vascularize damaged hearts. As such, multiple candidate cell types have been used to regenerate damaged hearts either directly (through differentiation to form new tissue) or indirectly (via paracrine effects). Emerging literature suggests that robust engraftment of electrophysiolgically heterogeneous tissue from transplanted cells comes at the cost of a high incidence of ventricular arrhythmias. Similar electrophysiological studies of haematological stem cells raised early concerns that transplant of depolarized, inexcitable cells that also induce paracrine‐mediated electrophysiological remodelling may be pro‐arrhythmic. However, meta‐analyses suggest that patients receiving haematological stem cells paradoxically may experience a decrease in ventricular arrhythmias, an observation potentially related to the extremely poor long‐term survival of injected cells. Finally, early clinical and preclinical data from technologies capable of differentiating to a mature cardiomyocyte phenotype (such as cardiac‐derived stem cells) suggests that these cells are not pro‐arrhythmic although they too lack robust long‐term engraftment. These results highlight the growing understanding that as next generation cell therapies are developed, emphasis should also be placed on understanding possible anti‐arrhythmic contributions of transplanted cells while vigilance is needed to predict and treat the inadvertent effects of regenerative cell therapies on the electrophysiological stability of the ischaemic cardiomyopathic heart.
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Full-Scale Validation of a Comprehensive Criterion to Predict Fish-Friendliness of Pumps
Authors: Krakers L. A. , Kruyt N. P. , Rutjes H. A. 
Published: November 2015

Many pumping stations in drainage & irrigation applications are currently equipped with conventional (not fish friendly designed) pumps. Field tests have been performed [1] for several pump types of a certain size at certain pumping conditions to assess survival rates of fish passing through pumps. In order to compare different pump types of different sizes at different pumping conditions, a general criterion is required.
Testing of fish friendliness of pumps is expensive and involves animal tests with living fish for which permits are required. Therefore, pump manufacturers prefer to perform fish friendliness tests for a single pump size. In order to convert such results to other pump sizes, a scaling law is desired. Van Esch [2, 3] made a first attempt to address scaling principles for fish friendliness of pumps.
In the current study a general criterion is described to predict fish friendliness of pumps by means of models of mortality rates of fish passing through pumps. The criterion is validated with literature data [1–3] and experimental full-scale test data from the newly developed fish-friendly axial flow concrete volute pump by Flowserve with an impeller diameter of 850 mm. The full-scale tests involved a total of 1800 roach, perch and eel deployed over 7 pumping conditions, including 3 different heads and 5 different rotational speeds.
The fish-friendliness criterion includes different aspects that together predict the survival rate of fish passing through pumps. The first and most important contributor is the impeller, which can have an axial, mixed or radial flow design. The criterion involves the leading edge shape of the blades. Secondly, the diffuser or volute is considered, which provides a strike probability with diffuser vanes or volute tongue(s). In case the gap between the trailing edge of the impeller vanes and the leading edge of the diffuser vanes or volute tongue(s) is small relative to the fish size, there is the possibility of a “scissor” effect. Research in the USA for fish friendliness of hydropower turbines [4–7] showed that shear velocity and pressure drops can be of importance. Also cavitation (involves pressure drop & vapor bubble implosions), recirculation and turbulence can influence survival rates. At this stage these flow effects are roughly captured using the pump performance curve. This way, extensive CFD calculations to evaluate detailed flow effects can be avoided. For open impellers, the gap between the impeller vanes and wear ring is included in the criterion. In addition, fish species-dependent effects are taken into account, since fish vary widely in their internal and external building plan. For instance salmonid, percid and cyprinid fish respond differently to the same pump design than for example eel. Sharp edges and rough surfaces (for example caused by cavitation, erosion or corrosion) can also be harmful to fish but are not included at this stage.
Investigation of Regenerator Matrix Through Figure of Merit Analysis
Authors: Gheith Ramla , Aloui Fethi , Ben Nasrallah Sassi 
Published: November 2015

To choose the adequate regenerator, that gives the highest Stirling engine performances, different compromises must be considered. The figure of Merits is a powerful tool to evaluate and compare the performance of different Stirling engine regenerator matrices. The figure of merits is usually defined as the ratio between the heat transfer performance and the pressure drop losses through the regenerator matrix. The figure of merits can be obtained too by calculating different rations of pressure drop ΔPPm of regenerator volume VdrVE and for regenerator loss Q.tQ.r
F M S C = 1 Δ P P m V d r V E Q . t Q . r
In this study the experimental results of various Gamma Stirling engine metallic wire regenerator matrices are presented. The figure of merit parameter will be estimated to determine the adequate regenerator. Then the FMSC was used to determine the best regenerator porosity and the optimal operation parameters.
Optimization of Anastomotic Geometry for Vascular Access Fistula
Authors: Bao Guangyu , Chen Xiaomin , Agarwal Ramesh K. 
Published: November 2015

Arteriovenous fistula (AVF) is one type of vascular access which is a surgically created vein used to remove and return blood during hemodialysis [1]. It is a long-term treatment for kidney failure. Although clinical treatment and technology have both achieved great improvements in recent years, the vascular access for hemodialysis still has significant early failure rates after the insertion of AVF in patients [2]. Studies have shown that stenosis in the vascular access circuit is the single major cause for access morbidity. Majority of efforts to understand the mechanisms of stenosis formation, and its prevention and management have largely focused on understanding and managing this complication based on the pathophysiology, tissue histology and molecular biology; however these efforts have not resulted in significant progress to date. We believe that the major impact in this area will come from continued and accurate understanding of the hemodynamics, and by development of techniques of intervention to modulate factors such as flow rates, pressures and compliance of the circuit.
The goal of this paper is to study anastomotic models of AV access using Computational Fluid Dynamics (CFD) and optimize them to minimize the wall shear stress (WSS). In order to achieve this goal, the commercial CFD software FLUENT [3] is employed in conjunction with a single objective genetic algorithm [4].
Computations for two types of AVF currently in use in clinical practice are performed. AVF with 25° angle/3–4mm diameter and 90° angle/3–5mm diameter are selected to conduct the optimization. A single-objective genetic algorithm is employed in the optimization process and a k-kl-ω turbulence model is employed in CFD simulations; this model can accurately compute transitional/turbulent flows. In order to optimize for the same flow conditions, a fixed boundary condition is used during the optimization process. Computations for 16 to 20 generations of the selected AVFs are obtained from the genetic algorithm solver. The maximum WSS in the two AVFs considered are 6997.8 and 7750 dynes/cm2; however, the maximum WSS in the shape-optimized AVFs are reduced to 3511.2 and 4293.9 dynes/cm2 respectively, which have decreased by 49.82% and 44.59% respectively. Thus, the probability of the formation of stenosis in AVFs and early failure rates of vascular access are reduced by using the optimized AVFs.
Investigation of Impeller Exit Flow Field in a Highly Loaded Centrifugal Compressor
Authors: Dutta Soumya , Sato Wataru , Funazaki Kenichi , Kakudate Yukiya 
Published: November 2015

Recently, the demand of a highly loaded impeller for industrial compressors is increasing due to environmental and economic reasons. In a compressor aerodynamic design including the matching of an impeller and a diffuser, it is very important to predict the impeller flow field precisely, but due to its high blade loading, a large flow separation and a strong clearance leakage flow occurring inside the impeller passage and impeller exit flow is distorted significantly. Thus it becomes difficult to predict a compressor performance with enough accuracy.
Therefore, in order to validate the prediction accuracy of CFD analysis to the highly loaded industrial compressor impeller, flow measurements at the impeller exit were conducted by using 3 holes yaw meter and hot wire anemometry traverse tests, and compared to the CFD results. CFD analysis was conducted by Iwate University using ANSYS CFX, in which SST model was applied to estimate turbulence intensity.
From the comparison between CFD results and measurements, significant difference in turbulence intensity and flow angles between measurements and CFD results could be observed at the impeller exit. These results imply that the reason behind this difference could be because CFD prediction underestimates the free stream turbulence and mixing effects between free stream and clearance flows.
Large-Scale Simulation of Rod Bundles: Coherent Structure Recognition and Stability Analysis
Authors: Merzari Elia , Fischer Paul , Walker Justin 
Published: November 2015

The axial flow in rod bundles has been the object of several investigations, since they are relevant for various industrial applications (e.g., heat exchangers, nuclear reactor cores). For tight configurations (pitch-to-diameter ratio smaller than 1.1) the large difference in velocity within the cross section creates the possibility of a Kelvin-Helmholtz instability and the generation of a vortex street in the gap (“gap instability”). While the presence of spacing devices may perturb the flow, simple grid spacers — grids of the type usually encountered in sodium fast reactors — do not prevent this instability.
This work seeks to improve our understanding of the gap instability in large rod bundles by using high-fidelity large-eddy simulation (LES). The application of LES methods has been historically limited to single-pin calculations because of the large cost of full-bundle calculations. However, using Nek5000, a massively parallel spectral-element computational fluid dynamics code, we are able to carry out well-resolved LES simulations for this class of geometries. Results are compared with experimental data. For the largest bundle case, over 8 billion collocation points at a polynomial order of 20 are judged necessary to achieve overall excellent accuracy. More than 500,000 processors are used to carry out the simulations (costing approximately 50,000,000 CPU-hours), and 3,000 snapshots of the flow field have been collected to apply several coherent structure recognition techniques, including one of the largest proper orthogonal decompositions carried out to date.
Also investigated here is the effect of geometry, including the (presence of spacers, changing pitch-to-diameter ratio, and canister wall. In particular, global linear stability analysis is applied to a series of simplified geometries in order to gain insight into the physics of the gap instability.
Finite Element Prediction of Multi-Size Particulate Flow Through Three-Dimensional Pump Casing
Authors: Pagalthivarthi Krishnan V. , Furlan John M. , Visintainer Robert J. 
Published: November 2015

Flow through centrifugal pump casing is highly complex in nature due to the complex geometry of the casing. While simplified two dimensional modeling of pump casing reveals the overall flow pattern and pressure distribution, a complete 3D model of pump casing is essential to fully capture the interaction of the primary main stream flow and the secondary flows especially in areas of heavy recirculation.
This paper presents steady state finite element simulation of multi-size particulate slurry flow through three dimensional pump casing. The flow field and concentration distribution is presented for different cross-sectional planes. The multi-size particulate flow simulation results are compared with two mono-size particle simulations using (1) the concentration weighted mean diameter of the slurry and (b) the D50 size of the slurry. Qualitative comparison is made with the wear rate predicted by the simulations and the field data. Simulations and field data show that at low flow rates, the side-wall gouging wear near the tongue region becomes significant.
Ultrasonic Measurements of Local Particle Velocity and Concentration Within the Casing of a Centrifugal Pump
Authors: Furlan John M. , Garman Mohamed , Kadambi Jaikrishnan , Visintainer Robert J. , Pagalthivarthi Krishnan V. 
Published: November 2015

In the design of slurry transport equipment used in the mining and dredging industries, the effects of solid particle velocity and concentration on hydraulic performance and wear need to be considered. Two ultrasonic techniques have been used to investigate slurry flows through a centrifugal pump casing: a local particle concentration measurement technique (Furlan et al., 2012) and a pulsed ultrasonic Doppler Velocimetry (PUDV) technique (Hanjiang, 2003, Garman, 2015).
Local particle velocities and concentrations have been obtained in a flow of soda lime glass particles (diameter of 195 μm) and water through the casing of a centrifugal slurry pump operating close to the best efficiency point using the two ultrasound techniques. For the concentration measurements, the acoustic properties of slurry flows such as sonic velocity, backscatter, and attenuation are correlated to the volume fraction of solid particles. The algorithm utilizes measurements obtained from homogeneous vertical pipe flow fields as calibration data in order to obtain experimental concentration profiles in the non-homogenous flow regimes which are encountered in the pump casing.
The PUDV technique correlates the Doppler shift in frequency associated with the movement of particles towards or away from the transducer. A two measurement (angle) technique is applied within the pump casing in order to account for the components of particle velocity which are orthogonal to the casing side wall. The techniques are utilized to obtain concentration and velocity profiles within the pump casing for overall average loop particle concentrations ranging from 7–11 % by volume.
The experimental results are compared with the concentration and velocity fields that are predicted by in-house finite element computational fluid dynamics (CFD) codes (Pagalthivarthi and Visintainer, 2009) which are used to predict wear in centrifugal slurry pump wet end components. Reasonable agreement is observed for both the concentration and velocity fields. Specifically, measurements indicate that there is a reduction of in-situ concentration and hence a corresponding radial acceleration of the particles with respect to the fluid occurring within the impeller which has also been predicted by computational predictions of flow through the impeller (Pagalthivarthi et al., 2013). Additionally, the prediction of the existence of secondary flow patterns by the casing computational code has been supported with the velocity measurements.
A Fully Coupled Flow and 6-DOF Motion Solver in Multiple Reference Frames
Authors: Shan Hua , Kim Sung-Eun , Rhee Bong 
Published: November 2015

In many computational fluid dynamics (CFD) applications involving a single rotating part, such as the flow through an open water propeller rotating at a constant rpm, it is convenient to formulate the governing equations in a non-inertial rotating frame. For flow problems consisting of both stationary and rotating parts, e.g. the stator and the rotor of a turbine, or the hull and propeller of a ship, the multiple reference frames (MRF) approach has been widely used. In most existing MRF models, the computation domain is divided into stationary and rotating zones. In the stationary zone, the flow equations are formulated in the inertial frame, while in the rotating zone, the equations are solved in the non-inertial rotating frame. Also, the flow is assumed to be steady in both zones and the flow solution in the rotating zone can be interpreted as the phase-locked time average result. Compared with other approaches, such as the actuator disk (body-force) model, the MRF approach is superior because it accounts for the actual geometry of the rotating part, e.g. propeller blades.
A more complicated situation occurs when the flow solver is coupled to the six degrees of freedom (6-DOF) equations of rigid-body motion in predicting the maneuver of a self-propelled surface or underwater vehicle. In many applications, the propeller is replaced by the actuator disk model. The current work attempts to extend the MRF approach to the 6-DOF maneuvering problems. The governing equations for unsteady incompressible flow in a non-inertial frame have been extended to the flow equations in multiple reference frames: a hull-fixed frame that undergoes translation and rotation predicted by the 6-DOF equations of motion and a propeller-fixed frame in relative rotation with respect to the hull. Because of the large disparity between time scales in the 6-DOF rigid body motion of the hull and the relative rotational motion of the propeller, the phase-locked solution in the propeller MRF zone is considered a reasonable approximation for the actual flow around the propeller. The flow equations are coupled to the 6-DOF equations of motion using an iterative coupling algorithm. The coupled solver has been developed as part of NavyFOAM. The theoretical framework and the numerical implementation of the coupled solver are outlined in this paper. Some numerical test results are also presented.
Towards Simulation of Clogging Effects in Wastewater Pumps: A Review of the State-of-the-Art in Cloth Modelling and Challenges in the Simulation of Clogging Effects
Authors: Jensen Anna Lyhne , Rosendahl Lasse , Sørensen Henrik , Lykholt-Ustrup Flemming 
Published: November 2015

Simulation of clogging effects caused by cloths in wastewater pumps enables a faster and cheaper design process of wastewater pumps, which potentially leads to a reduction in the occurrence of clogging. Four potential methods for cloth simulation are reviewed and the challenges of each method are identified and compared.
These methods are the Arbitrary Lagrangian-Eulerian (ALE) method, Immersed Boundary (IB) method, Smoothed Particle Hydrodynamics (SPH) coupled with the Finite Element method (FEM), and Computational Fluid Dynamics (CFD) coupled with the Discrete Element method (DEM).
Each method has advantages and disadvantages, and each of them may prove to be applicable for the application. The CFD-DEM approach is chosen for future work.