bluuebunny/crossref_metadata_2025_split huggingface dataset:
The 2-Stage Axial Turbine Test Facility “LISA”
Authors: Sell M. , Schlienger J. , Pfau A. , Treiber M. , Abhari R. S. 
Published: July 2014

This paper describes the design and construction of a new two stage axial turbine test facility, christened “Lisa”. The research objective of the rig is to study the impact (relevance) of unsteady flow phenomena upon the aerodynamic performance, this being achieved through the use of systematic studies of parametric changes in the stage geometry and operating point. Noteworthy in the design of the rig is the use of a twin shaft arrangement to decouple the stages. The inner shaft carries the load from the first stage whilst the outer is used with an integral torque-meter to measure the loading upon the second stage alone. This gives an accurate measurement of the loading upon the aerodynamically representative second stage, which possesses the correct stage inlet conditions in comparison to the full two stage machine which has an unrealistic axial inlet flow at the first stator. A calibrated Venturi nozzle measures the mass flow at an accuracy of below 1%, from which stage efficiencies can be derived.
The rig is arranged in a closed loop system. The turbine has a vertical arrangement and is connected through a gear box to a generator system that works as a brake to maintain the desired operating speed. The turbine exit is open to ambient pressure. The rig runs at a low pressure ratio of 1.5. The maximum Mach number at stator exit is 0.3 at an inlet pressure of 1.5 bar. The maximum mass flow is 14 kg/sec. Nominal rotor design speed is 3000 RPM. The tip to hub blade ratio is 1.29, and the nominal axial chord is 50 mm. The rig is designed to accommodate a broad range of measurement techniques, but with a strong emphasis upon unsteady flow methods, for example fast response aerodynamic pressure probes for time-resolved flow measurements.
The first section of this paper describes the overall test facility hardware. This is followed by a detailed focus on the torque measurement device including stage efficiency measurements at operating conditions in Lisa. Discussion of measurement techniques completes the paper.
Details of Axial-Compressor Shrouded Stator Cavity Flows
Authors: Wellborn Steven R. 
Published: July 2014

Data that reveal the structure and character of the flow in and near the cavities of compressor shrouded stators are reviewed. Results were obtained from low-speed multistage compressor measurements and simulations and generic high-speed cavity simulations. The experimental measurements were acquired with slow and fast response instrumentation. The numerical simulations were collected with two different flow solvers. The data are presented to provide compressor designers some indication of the complexities of the flow within shrouded stator cavities and to provide a datum for further studies on more complex geometries and flow conditions.
The data suggest surprisingly similar flow structures within most cavities including spatial and temporal flow field variations. In general, the flow in the cavities involved fluid moving in the circumferential direction with lower momentum than powerstream fluid. The difference in momentum is adjusted through a shear layer in the radial direction near the powerstream/cavity interface. Circumferential variations in flow properties also exist, the most prominent being caused by the upstream potential influence of the downstream blade. This influence caused the fluid within the cavities near the leading edges of the airfoils to be driven radially inward relative to fluid near mid-pitch. Some data are presented that suggest powerstream secondary flows dictate which fluid particles are ingested in the downstream cavity across the stator pitch. Vortical flow structures, similar to those set up by a driven cavity, dominate the axial variations in flow. The position and structure of these vortical structures are dependent upon the powerstream flow field and the cavity geometry.
Examining some interdependencies between cavity flow parameters concludes discussions of cavity flow field characteristics. A known relation between cavity leakage amount and tangential velocity is reiterated. Cavity rotational speed and stator exit swirl are also shown to influence the cavity tangential velocity. Increasing rotational speed tends to increase the tangential velocity through the cavity. Increasing the stator exit swirl reduces the tangential velocity increase.
Convective Heat Transfer and Aerodynamics in Axial Flow Turbines
Authors: Dunn Michael G. 
Published: July 2014

The primary focus of this paper is convective heat transfer in axial flow turbines. Research activity involving heat transfer generally separates into two related areas: predictions and measurements. The problems associated with predicting heat transfer are coupled with turbine aerodynamics because proper prediction of vane and blade surface-pressure distribution is essential for predicting the corresponding heat-transfer distribution. The experimental community has advanced to the point where time-averaged and time-resolved 3-D heat-transfer data for the vanes and blades are obtained routinely by those operating full-stage rotating turbines. However, there are relatively few CFD codes capable of generating 3-D predictions of the heat-transfer distribution, and where these codes have been applied the results suggest that additional work is required.
This paper outlines the progression of work done by the heat transfer community over the last several decades as both the measurements and the predictions have improved to current levels. To properly frame the problem, the paper reviews the influence of turbine aerodynamics on heat transfer predictions. This includes a discussion of time-resolved surface-pressure measurements with predictions and the data involved in forcing function measurements. The ability of existing 2-D and 3-D Navier Stokes codes to predict the proper trends of the time-averaged and unsteady pressure field for full-stage rotating turbines is demonstrated. Most of the codes do a reasonably good job of predicting the surface-pressure data at vane and blade midspan, but not as well near the hub or the tip region for the blade. In addition, the ability of the codes to predict surface-pressure distribution is significantly better than the corresponding heat-transfer distributions.
Heat-transfer codes are validated against measurements of one type or another. Sometimes the measurements are performed using full rotating rigs, and other times a much more simple geometry is used. In either case, it is important to review the measurement techniques currently used. Heat-transfer predictions for engine turbines are very difficult because the boundary conditions are not well known. The conditions at the exit of the combustor are generally not well known and a section of this paper discusses that problem. The majority of the discussion is devoted to external heat transfer with and without cooling, turbulence effects, and internal cooling.
As the design community increases the thrust to weight ratio and the turbine inlet temperature, there remain many turbine-related heat transfer issues. Included are film cooling modeling, definition of combustor exit conditions, understanding of blade tip distress, definition of hot streak migration, component fatigue, loss mechanisms in the low turbine, and many others. Several suggestions are given herein for research and development areas for which there is potentially high payoff to the industry with relatively small risk.
The Navy 500-Hour Test (NFHT) of the Intercooled Recuperated Gas Turbine Engine System (ICR)
Authors: Grala Carl P. , House Edward M. 
Published: July 2014

The Intercooled Recuperated Gas Turbine Engine System (ICR) is being developed by the United States Navy (USN) for shipboard application as a prime mover. The major development goal of the program is reduced fuel consumption relative to the LM2500, the current fielded gas turbine prime mover. This paper describes a 500-hour endurance test of the ICR system. The test was conducted at Naval Surface Warfare Center Carderock Division (NSWCCD), Philadelphia, in accordance with USN requirements which mimicked the qualification requirements for the system.
Data to assess the capability of the ICR to pass the qualification test was collected. Overall, the ICR has demonstrated a readiness to commence qualification testing.
The ICR completed the test with a total accumulated operating time of 457 hours and total endurance time of 322 hours. Achievement of the planned 500 endurance hours was precluded by persistent facility waterbrake problems.
Development of Fault Diagnosis and Failure Prediction Techniques for Small Gas Turbine Engines
Authors: Davison Craig R. , Birk A. M. 
Published: July 2014

A computer model of a gas turbine auxiliary power unit was produced to develop techniques for fault diagnosis and prediction of remaining life in small gas turbine engines. Due to the relatively low capital cost of small engines it is important that the techniques have both low capital and operating costs.
Failing engine components were identified with fault maps, and an algorithm was developed for predicting the time to failure, based on the engine’s past operation. Simulating daily engine operation over a maintenance cycle tested the techniques for identification and prediction. The simulation included daily variations in ambient conditions, operating time, load, engine speed and operating environment, to determine the amount of degradation per day. The algorithm successfully adapted to the daily changes and corrected the operating point back to standard conditions to predict the time to failure.
Design, Fabrication, and Testing of a Semi-Closed Cycle Gas Turbine Engine
Authors: Rodgers C. 
Published: July 2014

A small semi-closed gas turbine was designed, fabricated, and tested to demonstrate the cycle the cycle feasibility with exhaust gas recirculation. The demonstrator unit comprised a low pressure spool compressor and turbine supercharging a high pressure spool compressor and turbine, whose exhaust passed through a recuperator, and was subsequently split, one half being recirculated to the high pressure spool compressor inlet via an intercooler, and the remaining half expanded across the low pressure spool turbine.
The design and fabrication phases proceeded on schedule but commencement of engine development testing encountered mechanical difficulties. These were eventually resolved and shakedown testing of the demonstrator accomplished prior to final contractual delivery.
The demonstration program was funded under a NASA LeRc contract NAS3-27396.
An Assessment Method of Power Plants Using Genetic Algorithms
Authors: Codeceira Neto Alcides , Pilidis Pericles 
Published: July 2014

The performance assessment of power plants is a complex task, which involves many calculations. Increasing the number of plant components with the introduction of new technologies available in the international market, it increases the complexity of performance analysis of power cycles.
The present paper describes a process for optimising a conventional gas turbine combined cycle power plant. In this paper the method of assessing thermal power plants takes into account the exergy method and carries out along with optimisation of the whole plant based on maximising overall plant exergetic efficiency and minimising energy loss rejected to the atmosphere. The performance assessment of power plants using the exergy method considers the overall plant exergetic efficiency and the exergy destruction in the various components of the plant. The exergy method highlights irreversibility within the plant components, and it is of particular interest in this investigation.
Due to the large number of equations with many variables taking part in the whole calculation and also considering constraints imposed to some variables, a genetic algorithm is recommended as the optimisation tool for the assessment method. Genetic Algorithms are adaptive methods which may be used to solve search and optimisation problems. They are based on the genetic processes of biological organisms. Over many generations, natural populations evolve according to the principles of natural selection and “survival of the fittest”, first clearly stated by Charles Darwin in his book “The Origin of Species”. Genetic algorithms do not require complicate mathematical calculations like the evaluation of derivatives necessary to be considered in conventional optimisation techniques.
The Implementation of Spray Forming for High Temperature Casing Applications
Authors: Partridge Alan , Henderson Michael B. , Cole David G. , Andrews Paul 
Published: July 2014

Many current gas turbine casings are manufactured using conventional wrought processing routes. Although well established this approach often requires numerous and complex processing steps. This can result in relatively long component lead times and high part costs. In an attempt to reduce lead times and cost the production of parts using the spray-forming process is under consideration.
In the spray forming process the material is deposited from the molten state to produce a near net shape ring. The deposited ring is then subject to hot isostatic pressing (HIP) and/or ring rolling to consolidate the material and expand the ring to the required size. The material thus produced is usually relatively fine grained and can have a different balance of properties compared to conventionally processed alloys. However, the major advantage is that cost reductions can be achieved through the elimination of many process steps. In the current work a high temperature nickel alloy, RS5, has been produced as a spray formed ring. The influence of HIP and ring rolling have been investigated and a detailed microstructure-mechanical property assessment of the material has been carried out. The results of this work will be reported and the implications of the work on cost and manufacturing issues will be discussed.
Host-Directed Antimicrobial Drugs with Broad-Spectrum Efficacy against Intracellular Bacterial Pathogens
Authors: Czyż Daniel M. , Potluri Lakshmi-Prasad , Jain-Gupta Neeta , Riley Sean P. , Martinez Juan J. , Steck Theodore L. , Crosson Sean , Shuman Howard A. , Gabay Joëlle E. 
Published: July 2014

ABSTRACT

We sought a new approach to treating infections by intracellular bacteria, namely, by altering host cell functions that support their growth. We screened a library of 640 Food and Drug Administration (FDA)-approved compounds for agents that render THP-1 cells resistant to infection by four intracellular pathogens. We identified numerous drugs that are not antibiotics but were highly effective in inhibiting intracellular bacterial growth with limited toxicity to host cells. These compounds are likely to target three kinds of host functions: (i) G protein-coupled receptors, (ii) intracellular calcium signals, and (iii) membrane cholesterol distribution. The compounds that targeted G protein receptor signaling and calcium fluxes broadly inhibited
Coxiella burnetii
,
Legionella pneumophila
,
Brucella abortus
, and
Rickettsia conorii
, while those directed against cholesterol traffic strongly attenuated the intracellular growth of
C. burnetii
and
L. pneumophila
. These pathways probably support intracellular pathogen growth so that drugs that perturb them may be therapeutic candidates. Combining host- and pathogen-directed treatments is a strategy to decrease the emergence of drug-resistant intracellular bacterial pathogens.

IMPORTANCE
Although antibiotic treatment is often successful, it is becoming clear that alternatives to conventional pathogen-directed therapy must be developed in the face of increasing antibiotic resistance. Moreover, the costs and timing associated with the development of novel antimicrobials make repurposed FDA-approved drugs attractive host-targeted therapeutics. This paper describes a novel approach of identifying such host-targeted therapeutics against intracellular bacterial pathogens. We identified several FDA-approved drugs that inhibit the growth of intracellular bacteria, thereby implicating host intracellular pathways presumably utilized by bacteria during infection.
The Emergence of Bacterial “Hopeful Monsters”
Authors: Croucher Nicholas J. , Klugman Keith P. 
Published: July 2014

ABSTRACT

The global spread of antibiotic-resistant bacteria has largely been driven by the dissemination of successful lineages. A particularly important example is sequence type (ST) 258 of
Klebsiella pneumoniae
, a common cause of health care-associated infections. Representatives of this lineage carry a variable array of plasmid-borne resistance genes, typically including a carbapenemase effective against the full range of clinically important β-lactams. In their recent
mBio
article, Chen et al. [
mBio
5(3):e01355-14] described how ST258 emerged through “hybridization” between two other strains, with a second recombination resulting in the diversification of a key antigen. This commentary describes the findings in the context of other examples where saltational evolution has resulted in the sudden emergence of important pathogenic bacteria.
TLR7 Promotes Tumor Progression, Chemotherapy Resistance, and Poor Clinical Outcomes in Non–Small Cell Lung Cancer
Authors: Chatterjee Saradiya , Crozet Lucile , Damotte Diane , Iribarren Kristina , Schramm Catherine , Alifano Marco , Lupo Audrey , Cherfils-Vicini Julien , Goc Jeremy , Katsahian Sandrine , Younes Mohammad , Dieu-Nosjean Marie Caroline , Fridman Wolf Herman , Sautès-Fridman Catherine , Cremer Isabelle 
Published: July 2014

Abstract
Toll-like receptors (TLR) recognize pathogen molecules and danger-associated signals that stimulate inflammatory processes. TLRs have been studied mainly in antigen-presenting cells, where they exert important immune regulatory functions, but they are also expressed by epithelial tumor cells, where they have been implicated in tumor progression. In this study, we demonstrate that the injection of TLR7 agonist in NOD/SCID mice, in C57BL/6 wild-type, and TLR7-deficient mice grafted with lung adenocarcinoma tumor cells leads to increased tumor progression and chemotherapeutic resistance. In patients with non–small cell lung cancer, expression analyses revealed that high TLR7 expression was strongly associated with resistance to neoadjuvant chemotherapy and poor clinical outcomes. Our findings delineate a crucial role for TLR7 in lung cancer physiopathology. Cancer Res; 74(18); 5008–18. ©2014 AACR.
Molecular Pathways: Not a Simple Tube—The Many Functions of Blood Vessels
Authors: Orr Brent A. , Eberhart Charles G. 
Published: July 2014

Abstract
Although the ability of blood vessels to carry fluid and cells through neoplastic tissue is clearly important, other functions of vascular elements that drive tumor growth and progression are increasingly being recognized. Vessels can provide physical support and help regulate the stromal microenvironment within tumors, form niches for tumor-associated stem cells, serve as avenues for local tumor spread, and promote relative immune privilege. Understanding the molecular drivers of these phenotypes will be critical if we are to therapeutically target their protumorigenic effects. The potential for neoplastic cells to transdifferentiate into vascular and perivascular elements also needs to be better understood, as it has the potential to complicate such therapies. In this review, we provide a brief overview of these less conventional vascular functions in tumors. Clin Cancer Res; 21(1); 18–23. ©2014 AACR.
Reducing Contrast-Induced Acute Kidney Injury Using a Regional Multicenter Quality Improvement Intervention
Authors: Brown Jeremiah R. , Solomon Richard J. , Sarnak Mark J. , McCullough Peter A. , Splaine Mark E. , Davies Louise , Ross Cathy S. , Dauerman Harold L. , Stender Janette L. , Conley Sheila M. , Robb John F. , Chaisson Kristine , Boss Richard , Lambert Peggy , Goldberg David J. , Lucier Deborah , Fedele Frank A. , Kellett Mirle A. , Horton Susan , Phillips William J. , Downs Cynthia , Wiseman Alan , MacKenzie Todd A. , Malenka David J. 
Published: July 2014

Background—
Contrast-induced acute kidney injury (CI-AKI) is associated with increased morbidity and mortality after percutaneous coronary interventions and is a patient safety objective of the National Quality Forum. However, no formal quality improvement program to prevent CI-AKI has been conducted. Therefore, we sought to determine whether a 6-year regional multicenter quality improvement intervention could reduce CI-AKI after percutaneous coronary interventions.

Methods and Results—

We conducted a prospective multicenter quality improvement study to prevent CI-AKI (serum creatinine increase ≥0.3 mg/dL within 48 hours or ≥50% during hospitalization) among 21 067 nonemergent patients undergoing percutaneous coronary interventions at 10 hospitals between 2007 and 2012. Six intervention hospitals participated in the quality improvement intervention. Two hospitals with significantly lower baseline rates of CI-AKI, which served as benchmark sites and were used to develop the intervention, and 2 hospitals not receiving the intervention were used as controls. Using time series analysis and multilevel poisson regression clustering to the hospital level, we calculated adjusted risk ratios for CI-AKI comparing the intervention period to baseline. Adjusted rates of CI-AKI were significantly reduced in hospitals receiving the intervention by 21% (risk ratio, 0.79; 95% confidence interval: 0.67–0.93;
P
=0.005) for all patients and by 28% in patients with baseline estimated glomerular filtration rate <60 mL/min per 1.73 m
2
(risk ratio, 0.72; 95% confidence interval: 0.56–0.91;
P
=0.007). Benchmark hospitals had no significant changes in CI-AKI. Key qualitative system factors associated with improvement included multidisciplinary teams, limiting contrast volume, standardized fluid orders, intravenous fluid bolus, and patient education about oral hydration.

Conclusions—
Simple cost-effective quality improvement interventions can prevent ≤1 in 5 CI-AKI events in patients with undergoing nonemergent percutaneous coronary interventions.
Desert Dust Is a Risk Factor for the Incidence of Acute Myocardial Infarction in Western Japan
Authors: Matsukawa Ryuichi , Michikawa Takehiro , Ueda Kayo , Nitta Hiroshi , Kawasaki Tomohiro , Tashiro Hideki , Mohri Masahiro , Yamamoto Yusuke 
Published: July 2014

Background—
Recently, there has been increasing concern about adverse health effects of exposure to desert dust events. However, the association between dust and the incidence of ischemic heart diseases is unknown. The aim of the present study was to elucidate whether Asian dust (AD), a windblown sand dust originating from mineral soil in China and Mongolia, is associated with the incidence of acute myocardial infarction (AMI).

Methods and Results—
We investigated the data regarding hospitalization because of AMI among 3068 consecutive patients from 4 AMI centers in Fukuoka, Japan, and data for AD from April 2003 to December 2010. We applied a time-stratified case-crossover design to examine the association between AD and the incidence of AMI. Using a conditional logistic regression analysis, we estimated the odds ratios of AMI associated with AD after controlling for ambient temperature and relative humidity. The occurrence of AD events 0 to 4 days before the day of admission was significantly associated with the incidence of AMI. In particular, the occurrence of AD 4 days before admission was significantly associated with the onset of AMI.

Conclusions—
These data suggest that exposure to AD a few days before symptom onset is associated with the incidence of AMI.