bluuebunny/crossref_metadata_2025_split huggingface dataset:
Treatment for a eumycetoma infection caused by Aspergillus in an immunocompromised host: a case report
Authors: Hopps S. , Roach A. , Yuen C. , Borders E. 
Published: December 2014

AbstractEumycetoma is a chronic infection of the skin and subcutaneous tissue caused by filamentous fungi, which usually occurs in tropical or subtropical countries. We report a case of an immunocompromised patient presenting with presumed eumycetoma in the United States and his subsequent treatment with voriconazole. The use of voriconazole and liposomal amphotericin B halted the progression and allowed gradual resolution of the infection. The patient will require close monitoring and long‐term therapy with voriconazole to obtain a clinical cure. Voriconazole and liposomal amphotericin B are potential initial treatment options, with long‐term voriconazole maintenance therapy, for an Aspergillus‐induced eumycetoma.
Human papillomavirus‐related high‐grade squamous intraepithelial lesions of the esophagus, skin, and cervix in an adolescent lung transplant recipient: a case report and literature review
Authors: Freiberger D. , Lewis L. , Helfand L. 
Published: December 2014

AbstractHigh‐risk (carcinogenic) genotype human papillomavirus (HPV) infections can be associated with significant morbidity in the immunocompromised solid organ transplant (SOT) recipient. Immunosuppression‐associated persistent infection can predispose to the development of rapidly progressive high‐grade squamous intraepithelial lesions (HSIL) in this population. We present a case report of an adolescent bilateral lung transplant recipient who developed HSIL of the esophagus, cervix, and skin secondary to HPV. This review highlights the unique developmental needs of the sexually active adolescent SOT recipient and reviews guidelines for HPV‐related screening and education of this population.
Increased numbers of peripheral blood CD34+ cells in dogs with canine atopic dermatitis
Authors: Bruet Vincent , Lieubeau Blandine , Herve Julie , Roussel Anne , Imparato Laëtitia , Desfontis Jean‐Claude , Bourdeau Patrick 
Published: December 2014

BackgroundThe bone marrow may be involved in human atopic diseases, as shown by the release of CD34+ cells into the peripheral blood.Hypothesis/ObjectivesThe aim was to determine the numbers of CD34+ cells in atopic dogs.AnimalsThe following three groups of dogs were studied: 27 dogs with nonfood‐induced atopic dermatitis (NFICAD); 16 dogs with nonallergic inflammatory diseases; and 13 healthy control dogs.MethodsDogs with NFICAD were selected after fulfilment of Favrot's criteria and exclusion of other pruritic dermatoses, including flea infestation and adverse reaction to foods. The Canine Atopic Dermatitis Extent and Severity Index (CADESI)‐03 and a Visual Analog Scale (VAS) score for pruritus were used to quantify clinical signs. A phycoerythrin‐conjugated anticanine CD34 antibody was used to stain peripheral blood CD34+ cells, and these were enumerated using a flow cytometer. The CD34+ cell counts were compared between groups and tested (in the NFICAD group) for correlation with the severity of clinical signs.ResultsThe numbers of peripheral CD34+ cells in dogs with NFICAD (median 1.7) were statistically higher than in dogs with other nonallergic inflammatory diseases (median 1.0; P = 0.01) and healthy control dogs (median 0.9; P = 0.009). In dogs with NFICAD, there was no correlation between CD34+ cell numbers and CADESI‐03 scores or owner‐assessed pruritus (VAS score).Conclusions and clinical importanceThe results of this study suggest the possible involvement of CD34+ cells in dogs with NFICAD. The role of CD34+ cells in the aetiopathogenesis of canine atopic dermatitis remains to be determined.
Thickness Measurement of MCrAlY High-Temperature Coatings by Frequency Scanning Eddy Current Technique
Authors: Antonelli Giampiero , Ruzzier Marco , Necci Fiorenzo 
Published: December 2014

Nondestructive characterization of non-serviced high-temperature coatings can be considered one of the important factors to achieve a higher level of structural integrity of advanced gas turbines.
The present paper describes an innovative eddy current technique especially developed for measuring the thickness of metallic (MCrAlY) coatings applied by vacuum plasma spray on Ni-base superalloys. Conventional eddy current techniques, well established for quality control of coating thickness, are not applicable in this case because of the low difference of electrical conductivities of conting and base materials, which is a consequence of their quite similar physical and chemical properties.
The new technique employs fast frequency scanning of the electromagnetic field in the range 100 kHz – 10 MHz, corresponding to probing depths from 1 mm to 0.1 mm. Dedicated hardware has been developed, featuring high sensitivity, stability and harmonic rejection.
Analysis of the measured data (i.e. probe impedance vs frequency), in order to estimate the relevant diagnostic parameters (coating thickness, coating and base metal electrical conductivities), is carried out on the basis of a theoretical model of interaction between a plane electromagnetic wave and test piece.
The results of tests performed on a non-serviced first stage blade are reported and compared with reference destructive data. Reliability, accuracy and practical applicability of the method meets the requirements for in-shop quality control.
Comparison of Sweep and Dihedral Effects on Compressor Cascade Performance
Authors: Sasaki T. , Breugelmans F. 
Published: December 2014

The influence of two stacking lines, namely sweep and dihedral, has been investigated in a linear compressor cascade. Both types of blades considered are symmetrical about midspan and consist of a straight central section with either swept or dihedral sections towards the endwalls. Two types of experiments have been carried out.
Firstly, a parametric study was performed by changing both the magnitude and the extent of the sweep or dihedral. In the case of swept blades, those with forward sweep (SWF), for which the stacking line is swept in the upstream direction towards the endwall, were found to have better performance than backward swept blades. Subsequently, four sets of SWFs were compared. In the case of dihedral blades, it is well-known that the dihedral is advantageous when the angle between the suction surface and the endwall is obtuse, i.e. positive dihedral. Thus, four sets of positive dihedral blades (DHP) were compared. In both SWF and DHP blades, those configurations which have better efficiency than straight blades were determined.
Secondly, detailed three-dimensional measurements inside the blade passage were performed in the cases which showed the best performance in the parametric study. Both SWF and DHP showed significant effects on the flowfield. In the SWF case, a vortex, which has the opposite sense to the passage vortex, was observed in the forward portion inside the blade passage. This vortex supplies high-energy fluid to the endwall region and reduces the corner stall. The secondary flow is greatly reduced. In the DHP, the blade loading was reduced at the endwall and increased at the midspan. Also reduction of the corner stall and the secondary flow was observed.
A High Temperature Assessment of Air-Cooled Unsteady Pressure Transducers
Authors: Ferguson Derek G. , Ivey Paul C. 
Published: December 2014

This paper discusses the problem of measuring unsteady pressure in a high temperature environment using standard transducers. Commercially available cooling adapters for these transducers use water as the cooling medium to provide thermal protection. This arrangement is suitable only for some test bed applications and not suitable for integration into inflight active control systems.
An assessment of the cooling effectiveness of a commercial water cooled adapter using air as the cooling medium is presented using an experimentally validated finite element heat transfer model. The assessment indicates survival of an air-cooled transducer, itself rated to 235°C, at source flow temperatures up to 800°C.
Imbalance Response of a Test Rotor Supported on Squeeze Film Dampers
Authors: San Andrés Luis , Lubell Daniel 
Published: December 2014

Squeeze film dampers (SFDs) provide vibration attenuation and structural isolation to aircraft gas turbine engines which must be able to tolerate larger imbalances while operating above one or more critical speeds. Rotor-bearing-SFD systems are regarded in theory as highly nonlinear, showing jump-phenomena and even chaotic behavior for sufficiently large levels of rotor imbalance. Yet, few experimental results of practical value have verified the analytical predictions. A test rig for measurement of the dynamic forced response of a three-disk rotor (45 kg) supported on two cylindrical SFDs is described. The major objective is to provide a reliable data base to validate and enhance SFD design practice and to allow a direct comparison with analytical models. The open-ends SFD are supported by four-bar centering structures each with a stiffness of 3.5 MN/m. Measured synchronous responses to 9,000 rpm due to various imbalances show the rotor-SFD system to be well damped with amplification factors between 1.6 and 2.1 while traversing cylindrical and conical modes critical speeds. The rotor amplitudes of motion are found to be proportional to the imbalances for the first mode of vibration, and the damping coefficients extracted compare reasonably well to predictions based on the full-film open-ends SFD. Tight lip (elastomeric) seals contribute greatly to the overall damping of the test rig. Measured dynamic pressures at the squeeze film lands are well above ambient values with no indication of lubricant dynamic cavitation as simple theoretical models dictate. The measurements show absence of non-linear behavior of the rotor-SFD apparatus for the range of imbalances tested.
• The research program is a joint effort funded by the National Science Foundation (NSF) and the TAMU Turbomachinery Research Consortium (TRC).
Experimental and Numerical Conjugate Flow and Heat Transfer Investigation of a Shower-Head Cooled Turbine Guide Vane
Authors: Bohn Dieter E. , Becker Volker J. , Rungen Agnes U. 
Published: December 2014

This paper presents investigations of the development for a shower-head cooling configuration for a modern industrial turbine guide vane. One aim is to find suitable locations for cooling gas ejection with the lowest cooling gas mass flow possible. The investigations begin with a numerical experiment. After the prediction of a suitable configuration and operating parameters, the aerodynamics are investigated experimentally using a non-intrusive LDA technique.
Once the aerodynamics had been validated, the numerical experiments were expanded to a thermal analysis of the vane. Our conjugate flow and heat transfer simulation enables thermal analysis of the vane body without us having to derive any heat transfer data beforehand. The calculations were performed for a temperature ratio of 0.5 between cooling gas and main stream. This temperature ratio is similar to the operating conditions found in current designs.
The stagnation line moves under the influence of cooling gas ejection, which significantly influences the cooling gas distribution on the vane surface. The temperature distribution inside the vane is compared to a non-cooled test case. The simulation shows that the temperature peaks at the leading edge are reduced by between 18% and 44%.
Loading Software to Engine Controls in the Field
Authors: Beecher Scott F. , Lynch Bret G. 
Published: December 2014

With the advent of electronically alterable memories in electronic gas turbine engine control systems, there is now the opportunity for updating software in the field. Field loading provides a means to economically correct problems or introduce enhancements to system operation through the electronic control. In this paper we describe the characteristics of high integrity reprogramming systems used to update engine controls in-the-field.
Pratt & Whitney Aircraft supports two methods for in-service reprogramming of Electronic Engine Controls (EECs), These two methods are PC Laptop based loaders and ARINC loaders. This discussion will focus on the capabilities provided to support in-the-field reprogramming of engine controls. The flexibility, integrity, and the benefits of field reprogramming provided by these software loading systems will be explained. These reprogramming systems provide a PC based application and ARINC based systems for either on-wing reprogramming or on-board reprogramming directly from a flight deck device to the EEC.
The PC Loader reprogramming utilities allow field personnel to reprogram engine control application software and/or constants and configuration information using a suitably equipped IBM PC or compatible computer. These utilities are intended to be operated per Service Bulletin authorization only. They require a PC compatible computer (presumably a laptop model) with 2 UART interface cards, an interfacing cable, and the new software to be loaded. The rigor and manner of the integrity checks to ensure proper loading of the control is essential to an acceptable loading system.
There are two types of ARINC-based loaders: on-wing loaders and on-board loaders. Both types enable the operator to upload application, trim, and/or configuration software to the engine control. Additionally the ARINC 615 device allows operators to download fault and configuration data from the control. Each type of loader uses a specially formatted file to control the sequence of operations involved in a data loading session. The on-wing loader utilizes a specially designed portable data loader which connects directly to the EEC via dedicated cabling through the control’s ARINC connectors. This type of data loader contains software which communicates via an ARINC 615 protocol to a peer software entity running on the EEC. The on-board loader uses the aircraft’s central maintenance computer system to communicate with the EEC over the aircraft’s ARINC 629 data bus. It also operates using a peer-to-peer communication protocol with the EEC. The ARINC 629 loader requires no extra equipment or cabling, nor does it require the EEC to be accessible for attachment of cables.
Calibration of an 8-Pole Planar Radial Magnetic Actuator
Authors: Fittro Roger L. , Baun Dan O. , Maslen Eric H. , Allaire Paul E. 
Published: December 2014

Force versus coil currents and air gap measurements were obtained for an 8-pole planar radial magnetic actuator constructed from laminated silicon iron. Static force measurements were made for journal eccentricities up to 2/3 of the nominal actuator radial clearance and various coil currents spanning the expected operating range. Three theoretical force models of varying degrees of complexity were developed using magnetic circuit theory and constant magnetic material properties. All three models were used to reduce the experimental data and an optimized expression representing the actuator force as a function of journal position and stator coil currents was found. The resulting optimized calibration model produced a proportionality constant and equivalent iron length significantly different from theoretically determined values, 29% and 130% greater respectively.
A detailed error analysis was conducted to quantify the uncertainty in the bearing calibration relationship such that uncertainty bounds can be applied to the in situ actuator force measurements.
Hysteresis testing was conducted for various journal positions. Hysteresis effects were shown to be approximately 2% of the peak force when comparing the differences between the actuator force as the currents were increasing and the forces generated when the currents were decreasing. The actuator frequency response was also examined. An actuator bandwidth of at least 700 Hz was determined. Above 700 Hz the actuator frequency response could not be distinguished from the test fixture frequency response.
3-D Conjugate Flow and Heat Transfer Calculations of a Film-Cooled Turbine Guide Vane at Different Operation Conditions
Authors: Bohn Dieter E. , Becker Volker J. , Kusterer Karsten A. 
Published: December 2014

Film-cooling has become a widely used cooling method in present day gas turbines. Cooling gas ejection at the leading edge serves to protect the entire vane surface from contact with the hot gas. Thus, material temperatures must be reduced in order to guarantee an economically acceptable life span of the vane.
Normally, thermal investigations are performed with frozen equilibrium temperature distributions for different operating points. Thus, the heat transfer interaction between the flow and the solid body is neglected. This influence is taken into account by a conjugate fluid flow and heat transfer method in the investigations to be presented. In the case of the aerodynamics, a solver for the 3-D full Navier-Stokes equations is employed. The numerical scheme works on the basis of an implicit finite volume method combined with a multi-block technique.
In the 3-D numerical experiment to be presented, the influence of leading edge cooling gas ejection on the temperature distribution to the vane material is investigated. The cooling air is ejected through two slots at the leading edge. 3-D aerodynamic investigations performed by Bohn et al. (1996a) have shown the influence of complex 3-D flow phenomena, e.g. secondary flow, on the distribution of the cooling air along the vane surface. Furthermore, 3-D thermal investigations for one operation point with a realistic temperature ratio of cooling air flow and main flow were presented by Bohn et al. (1996b).
The investigations were performed for three different flow angles in the non-ejection case and the film-cooled case in order to demonstrate the operation of the cooling method. The shift of the stagnation line significantly influences the cooling fluid distribution along the vane surface, something that has consequences for the thermal load of the vane. Furthermore, the results are compared to an investigation with a prescribed frozen equilibrium temperature distribution. It is shown that the vane temperature increases locally for over 10 K at different operating points. This increase is significant for the thermal design process and can only be detected using the conjugate fluid flow and heat transfer method.
Getting to Problem Definition
Authors: Luchun Charles J. 
Published: December 2014

As the operational life of aircraft hardware increases, repetitions of phenomena previously explained as “isolated incidents” have been seen to occur. These problems are not necessarily application specific, nor material’s anomaly, nor design defect, nor operational abuse, nor any single cause, but, usually, an unfortunate combination of degradation in several of these factors, which becomes, statistically, more probable as the operational hours increase. Because they are rare, it can take years to collect enough clues to identify these links and synthesize the event.
When the problem involves an aging commercial aircraft turbine engine, that has passed from the designer to the manufacturer, and then to the airframer and the operator, through the hands of the maintainer, the repairer and the spare parts breakout supplier, the combinations of variables becomes too large to attack individually.
This paper characterizes a common sense approach to solving these problems. This approach favors a small team with a strong leader dedicated to that task. It is based on a theory that clues may be found in the history of the product and the industry, as well as in the exhibits and demographics of the incidents, and that a broad approach to fact finding, coupled with disciplined treatment of data, will allow the investigators to develop some intuitive sense of their problem, and facilitate linking of the pertinent facts.
This paper includes a hypothetical example, based on information in the public domain, of such a problem relating to an aging gas turbine engine. It is not meant to represent an actual case history, but is rather a combination of recognizable events, not uncommon, in either type or quantity, in the gas turbine industry, combined to illustrate this theory.
Some Applications of the Monte Carlo Method to Gas Turbine Performance Simulations
Authors: Kurzke Joachim 
Published: December 2014

The instrumentation readings taken during engine performance tests will show a random scatter that can be simulated with the Monte Carlo method. From such an exercise one can get the standard deviation of quantities that are derived from the pressure and temperature measurements like low pressure turbine efficiency of a high bypass engine, for example.
With the Monte Carlo Method a batch of engines can be simulated that have randomly distributed properties. Engine manufacturing tolerance in terms of thrust and specific fuel consumption can be derived from component production tolerance (efficiency, flow capacity) and internal air system variations. The Monte Carlo method is especially well suited for this task when complex interactions with the control system must be taken into account.
The Monte Carlo method can also be used to evaluate the confidence with which an overall engine performance level will be achieved from statements of component designers about the probability of achieving their design targets.
Tasks as described above can also be solved analytically, However, the Monte Carlo method is easier to use and also much less prone to error during its application.
Characteristics of a Turbine Cascade at Low Reynolds Numbers
Authors: Murata Koji , Abe Hiroyuki , Tsutsui Yasukata 
Published: December 2014

The aerodynamic characteristics of turbine cascades are thought to be relatively satisfactory due to the favorable pressure of the accelerating flow. But within the low Reynolds number region of 50,000 where the 300kW ceramic gas turbines which are being developed under the New-Sunshine Project of Japan operate, the characteristics such as boundary layer separation and reattachment which lead to prominent power losses cannot be easily predicted.
In this research, experiments have been conducted to evaluate the performance of a linear two dimensional turbine cascade. Surface pressure distributions of the airfoil were measured for a range of blade chord Reynolds numbers from 40,000 to 160,000 (at inlet), and at 1.3% inlet turbulence intensity. In addition, the wake of the cascade was measured simultaneously using a five hole pilot tube. Traverses of the wake show that there is a drastic increase in the mean total pressure loss at the wake between the Reynolds number of 80,000 to 40,000, and in some conditions, a rise as much as 10% was confirmed. Thus, in accordance with the pressure distribution of the surface of the airfoil, a relation between the total pressure loss and the length of the laminar separation bubble formed on the airfoil could be seen.