bluuebunny/crossref_metadata_2025_split huggingface dataset:
Invasion history and demographic processes associated with rapid morphological changes in the Red‐whiskered bulbul established on tropical islands
Authors: Le Gros Ariane , Clergeau Philippe , Zuccon Dario , Cornette Raphaël , Mathys Blake , Samadi Sarah 
Published: September 2016

AbstractThe Red‐whiskered bulbul is a very successful invasive bird species. Morphological differences have been reported among individuals inhabiting the humid and dry coasts of Reunion Island, in a 30‐year‐old population. This suggests a capacity for rapid local adaptation which could explain the general invasive success of this species. However, the origin and invasion history of this population is unknown. It is therefore not possible to establish with certainty the cause of these morphological differences. Here, we investigated the invasion history of populations of Red‐whiskered bulbul established on Reunion Island, Mauritius and Oahu (three geographically similar tropical islands) to assess the link between invasion history and morphological changes in these populations. We first assessed the source(s) of the invasive populations. We then compared the morphology of the individuals between the invasive and native populations and between the dry and humid coasts of invaded islands. Finally, we inferred the invasion history of the invasive populations to investigate the role of neutral processes (e.g. founder effect and drift) on morphology. We found that the invasive populations have a similar origin and that the morphology of the individuals in these populations has diverged in a similar way from the native range, suggesting a convergent adaptation to tropical islands. Like on Reunion, we found differences in morphology between the dry and humid coasts on Mauritius. These morphological differences can be explained by invasion history on Reunion but not on Mauritius. Both neutral evolution and adaptation thus shape the morphology of invasive Red‐whiskered bulbuls.
Distinguishing contemporary hybridization from past introgression with postgenomic ancestry‐informative SNPs in strongly differentiated Ciona species
Authors: Bouchemousse Sarah , Liautard‐Haag Cathy , Bierne Nicolas , Viard Frédérique 
Published: September 2016

AbstractBiological introductions bring into contact species that can still hybridize. The evolutionary outcomes of such secondary contacts may be diverse (e.g. adaptive introgression from or into the introduced species) but are not yet well examined in the wild. The recent secondary contact between the non‐native sea squirt Ciona robusta (formerly known as C. intestinalis type A) and its native congener C. intestinalis (formerly known as C. intestinalis type B), in the Western English Channel, provides an excellent case study to examine. To examine contemporary hybridization between the two species, we developed a panel of 310 ancestry‐informative SNPs from a population transcriptomic study. Hybridization rates were examined on 449 individuals sampled in eight sites from the sympatric range and five sites from allopatric ranges. The results clearly showed an almost complete absence of contemporary hybridization between the two species in syntopic localities, with only one‐first‐generation hybrid and no other genotype compatible with recent backcrosses. Despite the almost lack of contemporary hybridization, shared polymorphisms were observed in sympatric and allopatric populations of both species. Furthermore, one allopatric population from SE Pacific exhibited a higher rate of shared polymorphisms compared to all other C. robusta populations. Altogether, these results indicate that the observed level of shared polymorphism is more probably the outcome of ancient gene flow spread afterwards at a worldwide scale. They also emphasize efficient reproductive barriers preventing hybridization between introduced and native species, which suggests hybridization should not impede too much the expansion and the establishment of the non‐native species in its introduction range.
Do metabolic derangements in end‐stage polycystic kidney disease differ versus other primary kidney diseases?
Authors: Jankowska Magdalena , Qureshi Abdul Rashid , Barany Peter , Heimburger Olof , Stenvinkel Peter , Lindholm Bengt 
Published: September 2016

ABSTRACTAimAutosomal dominant polycystic kidney disease (ADPKD), a systemic disorder caused by mutation in genes encoding polycystins, has been reported to lead to metabolic derangements including new‐onset diabetes mellitus after kidney transplantation. We analyzed markers of insulin resistance (IR), inflammation, nutritional status and insulin‐like growth factor‐1 (IGF‐1) in end‐stage renal disease (ESRD) patients with ADPKD and ESRD patients with other primary kidney diseases.MethodsIn a post hoc cross‐sectional analysis in 254 non‐diabetic CKD 5 patients starting on dialysis, glucose metabolism (insulin, IGF‐1, homeostasis model assessment of IR, HOMA‐IR), inflammation (high sensitivity C‐reactive protein, interleukin‐6, and tumour necrosis factor), nutritional status, and bone mineral density (BMD), were assessed. Survival was recorded for median time of 28 months (IQR 15–48 months).ResultsNeither indices of IR, nor IGF‐1, inflammatory status, nutritional status, or BMD were different in patients with ADPKD as compared to other aetiologies of ESRD. Kaplan–Meier curves showed better survival among the ADPKD group versus other aetiologies, even after an exclusion of diabetic patients.ConclusionsThe ESRD phenotype did not differ in ADPKD versus other primary kidney diseases in terms of markers of IR, inflammation, and nutritional status. This argues against the proposition that ADPKD patients are more prone to develop metabolic derangements beyond those generally observed in advanced CKD. However, additional studies are warranted to further elucidate systemic metabolic aspects of ADPKD.
A New Scale for Assessing the Severity of Uncomplicated Diaper Dermatitis in Infants: Development and Validation
Authors: Buckley Brian S. , Mantaring Jacinto Blas , Dofitas Rodney B. , Lapitan Marie Carmela , Monteagudo Aceleen 
Published: September 2016

AbstractBackgroundOne methodologic challenge in conducting research relating to diaper dermatitis (DD) is the absence of a reliable, objective, validated scale for assessing severity. The aim of this study was to develop and validate such a scale.MethodsScale development was based on experience of DD assessment and clinical and photographic data collected during the early stages of a randomized controlled trial of two DD treatments. The severity score is the sum of scores of four domains: severity of erythema and irritation, area with any DD, papules or pustules, and open skin. Possible scores range from 0 (clear skin) to 6 (extensive DD including intense erythema, papules or pustules, and open skin with damage to the dermis). Assessors used the scale to attribute severity scores using high‐definition photographs of infants and babies with DD. Interrater reliability (IRR), internal consistency, and test–retest reliability were considered using intraclass correlation coefficients (ICCs), Cronbach's α, and Cohen κ statistics.ResultsIRR was very good between assessors familiar with the scale (ICC = 0.949, p < 0.001) and between assessors unfamiliar with the scale (ICC = 0.850, p < 0.001). Test–retest reliability at 2 weeks was good (κ = 0.603, p < 0.001). Cronbach's α for internal consistency was 0.702. Collation of photographs according to severity score revealed a visible continuum of DD severity, suggesting good construct validity.ConclusionThe newly developed scale appears to be easy to use, reliable, and effective in detecting increasing or lessening DD severity.
Life Settlement Funds: Current Valuation Practices and Areas for Improvement
Authors: Braun Alexander , Affolter Sarah , Schmeiser Hato 
Published: September 2016

AbstractWe analyze the prevailing valuation practices in the life settlement industry based on a sample of 11 funds that cover a large portion of the current market. The most striking result is that a majority of asset managers seem to substantially overvalue their portfolios relative to the prices of comparable transactions that have recently been closed. Drawing on market‐consistent estimates with regard to medical underwriting, it is possible to trace back the observed discrepancies to inadequately low model inputs for life expectancies and discount rates. The main consequences are a dissimilar treatment of investor groups in open‐end funds structures as well as an unduly high compensation for managers and third parties. To address this predicament, we suggest defining life settlements as level 2 assets in the fair value hierarchy of IFRS 13, improving transparency and disclosure requirements, and developing new incentive‐compatible fee schedules.
Innovative Shallow Sump Customizations for Aero-Engine Bearing Chambers
Authors: Chandra Budi , Simmons Kathy 
Published: September 2016

Aero-engines incorporate various bearing chambers and these typically contain bearings, seals, rotating shafts, stationary walls and struts, and sometimes gears. Oil is supplied for lubrication and cooling and is removed (scavenged) from the sump region of the chamber (note that in some parts of the world the entire bearing chamber is referred to as the sump). Depending on the location and function of the bearing chamber, the sump region may be deep or shallow. Effective oil removal is essential as unnecessary working of the oil can lead to excessive heat generation and reduced overall efficiency. Therefore the design of the scavenge region in a bearing chamber, as well as the ability to assess its performance is very important.
Previous work, much of which was conducted at the University of Nottingham Technology Centre in Gas Turbine Transmission Systems (UTC) suggests that oil often does not flow cleanly into the off-take due to a combination of several factors: oil momentum, windage, three-dimensional air flow that blocks the off-take flow or transports oil away from the off-take, and pooling because of separated air flow that acts on the oil once oil momentum is dissipated.
Experimental research at the UTC found that scavenge performance is highly affected by the sump geometry, especially its depth. Variations of shallow sumps, although some are better than the others, cannot offer the same level of performance as a deep one. However space limitation in an engine often only allows for a shallow sump. This paper presents some experimental exploration on new design ideas. They are in the form of various inserts and attachments that were designed to improve scavenge performance of a shallow sump. These “custom” sumps were tested on the UTC’s scavenge test facility at various flow settings (wall film/flying droplets, liquid flow rates, scavenge ratios, shaft speeds). The residence volumes were measured and compared to a baseline configuration with reduction in residence volume desirable.
The inserts tested were a Grille Cover, a Stepped Spillway, a Perforated Plate and a Porous Insert. Both the Porous Insert and the Perforated Plate showed reduced residence volumes in the demanding droplet/windage dominated flow condition with the Perforated Plate offering the best improvement over baseline.
Investigation of Penny Leakage Flows of Variable Guide Vanes in High Pressure Compressors
Authors: Wolf Hannes , Franke Matthias , Halcoussis Alexander , Kleinclaus Christophe , Gautier Sébastien 
Published: September 2016

In this paper, the modelling of leakages through a compressor stator penny cavity, and their effect on the aerodynamics within the compressor are studied. The penny, sometimes also referred to as ‘button’, is the cylindrical platform feature of a variable stator normally found between a vane’s airfoil and spindle. The pennies nominally lie recessed into the compressor endwalls at hub and casing, with a surrounding clearance to ensure the vane’s stagger angle can be adjusted. RANS-simulations, with these clearances included, have shown a significant impact from the penny cavity leakages on compressor efficiency and surge line. Neglecting this secondary flow path through the penny cavities results in an under prediction of the losses close to the endwalls.
The prediction of the penny cavity effect on the stator row is based on a Reynolds-Averaged-Navier-Stokes (RANS) study, using a hybrid structured-unstructured mesh to provide adequate resolution of the local flow phenomena.
The complex geometry and pressure field result in flows that are unevenly distributed within the penny cavity. The outflow or leakage is focused in a concentrated area leading to a high local velocity that strongly impacts the stator losses and turning. Since such geometries lie beyond the normal validated cases, the modelling uncertainties are discussed and the plausibility of the results is checked. In order to provide an experimental database and validate the turbulent mixing of leakage and main flow, which is seen as the main contributor to loss production, a validation test case — ‘Jet-In-Crossflow’ was chosen. As well as the standard RANS code, this validation case was run as a time-accurate high-order Lattice Boltzmann (LBM) simulation (PowerFLOW), using Very-Large-Eddy-Simulation (VLES) turbulence modelling. The LBM simulation showed significant unsteady flow features and was considerably closer to the test data than the RANS calculations.
A future test campaign, currently being prepared at the annular cascade test facility of the Institute of Jet Propulsion and Turbomachinery (IST) at RWTH Aachen university, will be briefly presented. This focuses on investigating the penny flows in a typical engine design.
Near Stall Behavior of a Transonic Compressor Rotor With Casing Treatment
Authors: Brandstetter Christoph , Holzinger Felix , Schiffer Heinz-Peter , Stapelfeldt Sina , Vahdati Mehdi 
Published: September 2016

The aerodynamic and aeroelastic performance of an advanced axial slot casing treatment (CT) was investigated on a modern one and a half stage transonic compressor test rig. It is generally accepted that a well designed CT can extend the aerodynamic stability range of a compressor to lower mass flows. The extension of stall margin of the compressor rotor blades by using CT has been the subject of numerous research articles but much less attention has been paid to the behavior of the compressor in direct vicinity of the stability limit. For the compressor investigated here, two different phenomena were repeatedly observed near stall: 1) self-excited blade vibration, and 2) low engine order fluctuations developing into rotating stall. The current investigation firstly aims to identify the triggers for each of these phenomena. It then focusses on the aerodynamic and aeromechanical mechanism which lead to the formation of low engine order fluctuations shortly before stall.
In order to measure the unsteady and transient effects, the system was instrumented with unsteady wall pressure transducers, a capacitive tip-timing system and strain gauges on the rotor blades. The flow structure in the blade tip region was measured via Particle Image Velocimetry underneath the CT-Cavities. Measurements showed a strong correlation between CT activity and the development of the low frequency oscillations with associated blade vibrations. Using numerical simulations, presented and validated in this paper, this correlation was attributed to an aerodynamic coupling between rotor passages through the recirculation of fluid inside the cavities.
Validation of Surface Temperature Measurements on a Combustor Liner Under Full-Load Conditions Using a Novel Thermal History Paint
Authors: Krewinkel Robert , Färber Jens , Lauer Martin , Frank Dirk , Orth Ulrich , Gonzalez Alvaro Yañez , Pilgrim Christopher , Feist Jörg , Saggese Raffaele , Berthier Stéphane , Araguas Silvia 
Published: September 2016

The ever-increasing requirements on gas turbine efficiency, which are at least partially met by increasing firing temperatures, and the simultaneous demand for reduced emissions, necessitate much more accurate calculations of the combustion process and combustor wall temperatures.
Thermocouples give locally very accurate measurements of these temperatures, but there is a practical limit to the amount of measurement points. Thermal paints are another established measurement technique, but are toxic and at the same time require dedicated, short-duration tests. Thermal History Paints (THPs) provide an innovative alternative to the aforementioned techniques, but so far only a limited number of tests has been conducted under real engine conditions.
THPs are similar in their chemical and physical make-up to conventional thermographic phosphors which have been successfully used in gas turbine applications for on-line temperature detection before. A typical THP comprises of oxide ceramic pigments and a water based binder. The ceramic is synthesized to be amorphous and when heated it crystallizes, permanently changing the microstructure. The ceramic is doped with lanthanide ions to make it phosphorescent. The lanthanide ions act as atomic level sensors and as the structure of the material changes, so do the phosphorescent properties of the material. By measuring the phosphorescence the maximum temperature of exposure can be determined through calibration, enabling post operation measurements at ambient conditions.
This paper describes a test in which THP was applied to an impingement-cooled front panel from a combustor of an industrial gas turbine. Since this component sees a wide range of temperatures, it is ideally suited for the testing of the measurement techniques under real engine conditions. The panel was instrumented with a thermocouple and thermal paint was applied to the cold side of the impingement plate. THP was applied to the hot-gas side of this plate for validation against the other measurement techniques and to evaluate its resilience against the reacting hot gas environment.
The durability and temperature results of the three different measurement techniques are discussed. The results demonstrate the benefits of THPs as a new temperature profiling technique. It is shown that the THP exhibited greater durability compared to the conventional thermal paint. Furthermore, the new technology provided detailed measurements down to millimeters indicating local temperature variations and global variations over the complete component.
Numerically Derived Design Guidelines of Self Recirculation Casing Treatment for Industrial Centrifugal Compressors
Authors: Jung Sewoong , Pelton Robert 
Published: September 2016

Casing treatments are a well-known method to extend operating range of centrifugal compressors. A common casing treatment configuration consists of a passage that allows flow from the impeller shroud to be bleed back to the inlet of the stage. This type of casing treatment is used frequently in some applications, including automotive turbochargers, but is rarely used in industrial compressors. An effective casing treatment must be developed specifically to match a given stage. For high volume production products this is practical. For the wide variety of industrial compressor designs, which are produced in low volumes, it is not often cost effective to design a casing treatment to match each application. To help reduce the design effort associated with developing a new casing treatment design, a simple set of design guidelines were developed. These guidelines are based on the results of a computational fluid dynamic (CFD) study of several different class impellers. These guidelines can be used to correctly locate and size the key geometric features of a self-recirculating casing treatment, including slot width, position and cavity vane profile.
The study found that the bleed slot position and width were the primary factors controlling performance of the casing treatment. In general, when the slot width is wider and the bleed position is moved further downstream, the range increases but the efficiency falls. The optimal slot width is found to be when the slot area is 23% of the area of inducer eye and positioning the slot near the impeller throat gives a good balance of increased range with minimal efficiency loss. A well designed casing treatment is expected to result in approximately a 25% increase in range while keeping the drop in efficiency less than 0.4 point for the cases considered in this study. In addition, the rise to surge increased more than 60% and turndown almost doubled value with the optimized design.
Dynamic Analysis of a Recuperated mGT Cycle for Fuel Cell Hybrid Systems
Authors: Larosa Luca , Traverso Alberto , Massardo Aristide F. 
Published: September 2016

This work presents the dynamic behaviour of a new recuperated micro gas turbine (mGT) coupled with a large volume. Such system, called “emulator”, has been purposely designed for the future upgrade into a fuel cell mGT hybrid system. The tests, carried out by LG Fuel Cell Systems (LGFCS), aimed both at understanding the dynamic behaviour of the system and validating the dynamic simulation tool.
Within the wide experimental campaign, a subset of data has been selected to identify the key transient phenomena and characterise the dynamic behaviour of the system: in this respect, the focus is on start-up, warm-up and shutdown phases.
A dynamic model of the emulator was developed, based on the original software TRANSEO. The model was used to characterise the mGT performance and identify a performance gap in the expander. For this purpose, the machine was upgraded and substituted. Final results show that, after refinement of input data, the model is capable to predict accurately the overall system transient behaviour.