bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow Measurement in a Multistage Large Scale Low Speed Axial Flow Research Compressor
Authors: Boos P. , Möckel H. , Henne J. M. , Seimeler R. 
Published: December 2014

In this paper the newly built large scale low speed axial flow research compressor at Dresden University of Technology is presented. This compressor rig serves three main purposes. Firstly, it shall improve the understanding of compressor aerodynamics (especially secondary flows) by allowing detailed flow field measurements without heavily disturbing the flow. Secondly, it will be used to examine new design concepts. Thirdly, the detailed measurements in the absolute and relative system will be used for the calibration of existing CFD-codes.
The design and the construction of the test rig which will allow an easy variation of the test configuration is described. A short view of the different data acquisition units for steady and unsteady measurement in the stationary and rotating system will be given.
The blading of the compressor in the first series of test runs simulates a middle stage of a contemporary high-pressure compressor. Measurement data will be compared with results of 3D-Navier-Stokes calculations that were performed at MTU München.
Heat Load on the Walls of an Annular DLE Combustor Calculation and Comparison With Experiments
Authors: Janczewski Jacek , Nilsson Ulf , Strand Torsten , Troger Christian 
Published: December 2014

The knowledge of the hot gas side heat load is a necessary prerequisite for the design of the advanced cooling scheme of a dry low-NOx combustor and the mechanical integrity (MIT) calculations of the combustor walls. The magnitude and the spatial distribution of the heat fluxes has to be known in the very early phase of the design, where there is no hardware available.
The evaluation of a combustor wall design has to be based on known process data, thermodynamic and combustion parameters and has to rely on computational methods and experience.
A stepwise computational approach is presented to reach this target utilising
• 1D flow and Nusselt-Number correlations
• 2-D boundary layer code
• computational fluid dynamics (CFD)
For the validation of the method atmospheric and pressurised single burner combustor tests were performed.
The relative merits and pitfalls of the different methods are discussed in detail. Recommendations for their utilisation within the design process and for their further development are given.
On 3D Inverse Design of Centrifugal Compressor Impellers With Splitter Blades
Authors: Zangeneh M. 
Published: December 2014

In the design of centrifugal compressor impellers with splitter blades it is quite common to use the same blade shapes on the full and splitter blades with the splitters placed at the mid-pitch location. However, recent results using conventional design methodology have indicated that by moving the pitchwise location of the leading edge of the splitter it is possible to improve splitter performance.
In this paper a 3D inverse design method is developed for the design of compressor impellers with splitters. In this design method the blades are designed subject to a specified distribution of the circulation on the full and splitter blades. The paper describes the choice of loading (or derivative of circulation with respect to meridional distance) and stacking condition to limit the complexity of the blade shape. Two different generic impellers are designed with different splitter leading edge location. The performance of these inverse designed impellers is then compared with the corresponding conventional impellers by using a 3D viscous code at design and off-design conditions.
Long Term Thermal Stability of INCONEL Alloy 783
Authors: Mannan Sarwan , deBarbadillo John 
Published: December 2014

Recently developed INCONEL® alloy 783 (nominal composition of Ni-34Co-26Fe-5.4Al-3Nb-3Cr) is precipitation strengthened by Ni3Al-type Gamma Prime and NiAl-type Beta Phases. Due to its low co-efficient of thermal expansion (CTE), high strength, and good oxidation resistance alloy 783 has been specified for use in aircraft gas turbine components such as rings, casings, shrouds, and seals and has been considered for use in a number of other critical industrial turbine components.
In this study, commercially produced alloys 783, 718, and 909 were annealed and aged following recommended heat treatments. The materials were then isothermally exposed at 1100°F (593°C) for times up to 10,000 hours. At 1000 hour intervals, specimens of these alloys were removed from the furnace and subjected to room temperature tensile (RTT) and high temperature tensile (HTT) testing at 1200°F (649°C). The microstructure of as-produced and exposed materials was characterized using optical microscopy, Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). Variation in tensile properties with isothermal exposure time was correlated with the microstructure.
Characteristics of an Annular Turbine Cascade at Low Reynolds Numbers
Authors: Matsunuma Takayuki , Abe Hiroyuki , Tsutsui Yasukata , Murata Koji 
Published: December 2014

The aerodynamic characteristics of turbine cascades are thought to be relatively satisfactory due to the favorable pressure gradient of the accelerating flow. But within the low Reynolds number region of approximately 6×104 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, reattachment and secondary flow which lead to prominent power losses can not be easily predicted.
In this research, experiments have been conducted to evaluate the performance of an annular turbine stator cascade. Wakes of the cascade were measured using a single hot wire and five hole pressure tube, for a range of blade chord Reynolds numbers based on the inlet condition from 2×104 to 12×104. Flow visualizations on the suction surface of the blade were carried out using oil film method. At low Reynolds numbers, the flow structure in the annular cascade was quite complex and three-dimensional. The separation line on the suction surface moved upstream due to the decrease of Reynolds number. In addition, the growth of secondary flows, i.e., passage vortices and leakage vortex, was extremely under the influence of Reynolds number.
ABB’s Advanced EV Burner — A Dual Fuel Dry Low NOx Burner for Stationary Gas Turbines
Authors: Steinbach Christian , Ruck Thomas , Lloyd Jonathan , Jansohn Peter , Döbbeling Klaus , Sattelmayer Thomas , Strand Torsten 
Published: December 2014

A dual fuel burner has been developed to meet stringent NOx goals without the use of water or steam injection. This combustion system is based on the proven ABB EV burner dry low NOx technology and uses the same type of aerodynamic vortex breakdown flame stabilization. A more advanced aerodynamic design improves the quality of the fuel air mixture for both gaseous and liquid fuels. The design of the liquid fuel injection and the fuel-air-mixture preparation is described in this paper. Fuel air mixture homogeneity was improved with the help of experimental and numerical tools. This way an optimization in fuel atomizer design was possible. Distinct differences in fuel distribution were observed for different designs of pressure atomizers. Combustion tests of the burner were performed at pressures up to 20 bars. The NOx levels measured under gas turbine full load conditions are <25 vppm using oil no. 2 and <10 vppm using natural gas. These results highlight the potential for achieving similar combustion low emission performance for gaseous and liquid fuels near perfect lean premix conditions.
Operating parameters and test results at part load conditions are discussed as well in this paper. The wide operating range of the burner in the full premix mode restricts the need for pilot application or burner staging to low load (<50 %) conditions. This allows for low emissions on NOx, CO and UHC in the entire load range.
Steady and Unsteady Three-Dimensional Flow Field Downstream of an Embedded Stator in a Multistage Axial Flow Compressor: Part 1 — Unsteady Velocity Field
Authors: Prato J. , Lakshminarayana B. , Suryavamshi N. 
Published: December 2014

A comprehensive investigation of the three-dimensional unsteady flow and thermal field downstream of an embedded stator in a multistage compressor, acquired with a high-response hot-film probe and aspirating probe, is presented and analyzed. Some of the earlier data (five-hole probe and high-response Kulite probe) from the same compressor is used with the present data to provide an integrated and comprehensive interpretation of the flow and thermal fields. The emphasis is on the unsteady flow, unsteady thermal, and integrated flow fields. Part 1 covers the description of the facility and the development of the hot-film technique for multistage flow field measurement. In addition, the unsteady velocity field is presented and interpreted. Part 2 provides an integrated assessment of the stagnation pressure, temperature and velocity fields to derive a comprehensive understanding of the time-averaged flow features. The final part covers velocity-velocity and velocity-temperature correlations and the assessment of their magnitudes in the average-passage equations.
The results from an area traverse of the unsteady velocity field derived from a 45 degree slanted film probe downstream of the second stator of a three-stage axial flow compressor are presented and discussed in this paper. The measurements were conducted at the peak efficiency operating point using a four-rotation method. The ensemble-averaged unsteady three-dimensional velocity data is resolved into the time-averaged component, revolution and blade periodic, and aperiodic components. Some of the features of the rotor 2 flow, measured at the exit of stator 2, reveal the extent of the spread of the upstream rotor wakes and the unsteadiness due to rotor hub and leakage flow regions and levels of periodic and aperiodic unsteadiness. Both the revolution and blade periodic velocity fluctuations are seen to be significantly greater than the aperiodic fluctuations.
Experimental Analysis of Fluid Flow and Surface Heat Transfer in a Three-Pass Trapezoidal Serpentine Smooth Passage
Authors: Cravero C. , Giusto C. , Massardo A. F. 
Published: December 2014

The fluid-dynamic and heat transfer experimental analysis of a gas turbine internal three-pass blade cooling channel is presented.
The passage is composed of three rectilinear channels joined by two sharp 180 degree turns; moreover the channel section is trapezoidal instead of the rectangular configuration already analysed in depth in literature. The trapezoidal section is more representative of the actual geometrical configuration of the blade and, in comparison with the rectangular section, it shows significant aspect ratio and hydraulic diameter variations along the channel. These variations have a strong impact on the flow field and the heat transfer coefficient distributions.
The flow analysis experimental results — wall pressure distributions, flow visualisations — are presented and discussed. The heat transfer coefficient distributions, Nusselt enhancement factor, obtained using Thermocromic Liquid Crystals (TLC), have been studied as well.
In order to understand the influence of the cooling mass flow rate, a wide range of flow regimes-Reynolds numbers- has been considered.
3D Flow Field Measurement Around a Rotating Stall Cell
Authors: Palomba C. , Puddu P. , Nurzia F. 
Published: December 2014

Rotating stall is an unsteady phenomenon that arises in axial and radial flow compressors. Under certain operating conditions a more or less regular cell of turbulent flow develops and propagates around the annulus at a speed lower than rotor speed. Recently little work has been devoted to the understanding of the flow field pattern inside a rotating cell. However, this knowledge could be of help in the understanding of the interaction between the cell and the surrounding flow. Such information could be extremely important during the modelling process when some hypothesis have to be made about the cell behaviour.
A detailed experimental investigation has been conducted during one cell operation of an isolated low-speed axial flow compressor rotor using a slanted hot wire and an ensemble average technique based on the cell revolution time. The three flow field components have been measured on 9 axial section for 800 circumferential points and on 21 radial stations to give a complete description of the flow field upstream and downstream of the rotor. Interpretation of data can give a description of the mean flow field patterns inside and around the rotating cell.
A universal dose–response curve for radiochromic films
Authors: Martín‐Viera Cueto J. A. , Parra Osorio V. , Moreno Sáiz C. , Navarro Guirado F. , Casado Villalón F. J. , Galán Montenegro P. 
Published: December 2014

Purpose:This paper presents a model for dose–response curves of radiochromic films. It is based on a modified version of single‐hit model to take into account the growth experienced by lithium salt of pentacosa‐10,12‐diynoic acid polymers after irradiation.Methods:Polymer growth in radiochromic films is a critical phenomenon that can be properly described by means of percolation theory to provide an appropriate distribution function for polymer sizes. Resulting functional form is a power function featuring a critical exponent and two adjustable parameters. Moreover, these parameters act as scaling factors setting a natural scale for sensitometric curves where the dependence on channel sensitivity is removed. A unique reduced response curve is then obtained from all the color channels describing film behavior independently of film dosimetry system.Results:Resulting functional form has been successfully tested in several sensitometric curves from different Gafchromic EBT models, providing excellent agreement with experimental data in a wide dose range up to about 40 Gy and low dose uncertainty.Conclusions:The model presented in this paper describes accurately the sensitometric curves of radiochromic films in wide dose ranges covering all typical ranges used in external radiotherapy. Resulting dose uncertainty is low enough to render a reasonably good performance in clinical applications. Due to cross‐correlation, only one of the adjustable parameters is totally independent and characterizes film batches.
The MSPDBL2 Codon 591 Polymorphism Is Associated with Lumefantrine
In Vitro
Drug Responses in Plasmodium falciparum Isolates from Kilifi, Kenya
Authors: Ochola-Oyier Lynette Isabella , Okombo John , Mwai Leah , Kiara Steven M. , Pole Lewa , Tetteh Kevin K. A. , Nzila Alexis , Marsh Kevin 
Published: December 2014

ABSTRACT

The mechanisms of drug resistance development in the
Plasmodium falciparum
parasite to lumefantrine (LUM), commonly used in combination with artemisinin, are still unclear. We assessed the polymorphisms of
Pfmspdbl2
for associations with LUM activity in a Kenyan population. MSPDBL2 codon 591S was associated with reduced susceptibility to LUM (
P
= 0.04). The high frequency of
Pfmspdbl2
codon 591S in Kenya may be driven by the widespread use of lumefantrine in artemisinin combination therapy (Coartem).
Posaconazole Prophylaxis in Experimental Azole-Resistant Invasive Pulmonary Aspergillosis
Authors: Seyedmousavi Seyedmojtaba , Mouton Johan W. , Melchers Willem J. G. , Verweij Paul E. 
Published: December 2014

ABSTRACT

We investigated the efficacy of posaconazole prophylaxis in preventing invasive aspergillosis due to azole-resistant
Aspergillus fumigatus
isolates. Using a neutropenic murine model of pulmonary infection, posaconazole prophylaxis was evaluated using three isogenic clinical isolates, with posaconazole MICs of 0.063 mg/liter (wild type), 0.5 mg/liter (F219I mutation), and 16 mg/liter. A fourth isolate harboring TR
34
/L98H (MIC of 0.5 mg/liter) was also tested. Posaconazole prophylaxis was effective in
A. fumigatus
with posaconazole MICs of ≤0.5 mg/liter, where 100% survival was reached. However, breakthrough infection was observed in mice infected with the isolate for which the posaconazole MIC was >16 mg/liter.
A High-Affinity Native Human Antibody Neutralizes Human Cytomegalovirus Infection of Diverse Cell Types
Authors: Kauvar Lawrence M. , Liu Keyi , Park Minha , DeChene Neal , Stephenson Robert , Tenorio Edgar , Ellsworth Stote L. , Tabata Takako , Petitt Matthew , Tsuge Mitsuru , Fang-Hoover June , Adler Stuart P. , Cui Xiaohong , McVoy Michael A. , Pereira Lenore 
Published: December 2014

ABSTRACT

Human cytomegalovirus (HCMV) is the most common infection causing poor outcomes among transplant recipients. Maternal infection and transplacental transmission are major causes of permanent birth defects. Although no active vaccines to prevent HCMV infection have been approved, passive immunization with HCMV-specific immunoglobulin has shown promise in the treatment of both transplant and congenital indications. Antibodies targeting the viral glycoprotein B (gB) surface protein are known to neutralize HCMV infectivity, with high-affinity binding being a desirable trait, both to compete with low-affinity antibodies that promote the transmission of virus across the placenta and to displace nonneutralizing antibodies binding nearby epitopes. Using a miniaturized screening technology to characterize secreted IgG from single human B lymphocytes, 30 antibodies directed against gB were previously cloned. The most potent clone, TRL345, is described here. Its measured affinity was 1 pM for the highly conserved site I of the AD-2 epitope of gB. Strain-independent neutralization was confirmed for 15 primary HCMV clinical isolates. TRL345 prevented HCMV infection of placental fibroblasts, smooth muscle cells, endothelial cells, and epithelial cells, and it inhibited postinfection HCMV spread in epithelial cells. The potential utility for preventing congenital transmission is supported by the blockage of HCMV infection of placental cell types central to virus transmission to the fetus, including differentiating cytotrophoblasts, trophoblast progenitor cells, and placental fibroblasts. Further, TRL345 was effective at controlling an
ex vivo
infection of human placental anchoring villi. TRL345 has been utilized on a commercial scale and is a candidate for clinical evaluation.
Photoheterotrophic Fluxome in Synechocystis sp. Strain PCC 6803 and Its Implications for Cyanobacterial Bioenergetics
Authors: You Le , He Lian , Tang Yinjie J. 
Published: December 2014

ABSTRACT

This study investigated metabolic responses in
Synechocystis
sp. strain PCC 6803 to photosynthetic impairment. We used 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU; a photosystem II inhibitor) to block O
2
evolution and ATP/NADPH generation by linear electron flow. Based on
13
C-metabolic flux analysis (
13
C-MFA) and RNA sequencing, we have found that
Synechocystis
sp. PCC 6803 employs a unique photoheterotrophic metabolism. First, glucose catabolism forms a cyclic route that includes the oxidative pentose phosphate (OPP) pathway and the glucose-6-phosphate isomerase (PGI) reaction. Glucose-6-phosphate is extensively degraded by the OPP pathway for NADPH production and is replenished by the reversed PGI reaction. Second, the Calvin cycle is not fully functional, but RubisCO continues to fix CO
2
and synthesize 3-phosphoglycerate. Third, the relative flux through the complete tricarboxylic acid (TCA) cycle and succinate dehydrogenase is small under heterotrophic conditions, indicating that the newly discovered cyanobacterial TCA cycle (via the γ-aminobutyric acid pathway or α-ketoglutarate decarboxylase/succinic semialdehyde dehydrogenase) plays a minimal role in energy metabolism. Fourth, NAD(P)H oxidation and the cyclic electron flow (CEF) around photosystem I are the two main ATP sources, and the CEF accounts for at least 40% of total ATP generation from photoheterotrophic metabolism (without considering maintenance loss). This study not only demonstrates a new topology for carbohydrate oxidation but also provides quantitative insights into metabolic bioenergetics in cyanobacteria.
A
prl
Mutation in SecY Suppresses Secretion and Virulence Defects of Listeria monocytogenes secA2 Mutants
Authors: Durack Juliana , Burke Thomas P. , Portnoy Daniel A. 
Published: December 2014

ABSTRACT

The bulk of bacterial protein secretion occurs through the conserved SecY translocation channel that is powered by SecA-dependent ATP hydrolysis. Many Gram-positive bacteria, including the human pathogen
Listeria monocytogenes
, possess an additional nonessential specialized ATPase, SecA2. SecA2-dependent secretion is required for normal cell morphology and virulence in
L. monocytogenes
; however, the mechanism of export via this pathway is poorly understood.
L. monocytogenes
secA2
mutants form rough colonies, have septation defects, are impaired for swarming motility, and form small plaques in tissue culture cells. In this study, 70 spontaneous mutants were isolated that restored swarming motility to
L. monocytogenes
secA2
mutants. Most of the mutants had smooth colony morphology and septated normally, but all were lysozyme sensitive. Five representative mutants were subjected to whole-genome sequencing. Four of the five had mutations in proteins encoded by the
lmo2769
operon that conferred lysozyme sensitivity and increased swarming but did not rescue virulence defects. A point mutation in
secY
was identified that conferred smooth colony morphology to
secA2
mutants, restored wild-type plaque formation, and increased virulence in mice. This
secY
mutation resembled a
prl
suppressor known to expand the repertoire of proteins secreted through the SecY translocation complex. Accordingly, the Δ
secA2prlA1
mutant showed wild-type secretion levels of P60, an established SecA2-dependent secreted autolysin. Although the
prl
mutation largely suppressed almost all of the measurable SecA2-dependent traits, the Δ
secA2prlA1
mutant was still less virulent
in vivo
than the wild-type strain, suggesting that SecA2 function was still required for pathogenesis.
Pulmonary tuberculosis among migrants in Shandong, China: factors associated with treatment delay
Authors: Zhou Chengchao , Chu Jie , Geng Hong , Wang Xingzhou , Xu Lingzhong 
Published: December 2014

ObjectiveA timely initiation of treatment is crucial to better control tuberculosis (TB). The aim of this study is to describe treatment delay among migrant patients with TB and to identify factors associated with treatment delay, so as to provide evidence for strategy development and improvement of TB control among migrants in China.DesignA cross-sectional study was conducted in Shandong province of China. A total of 314 confirmed smear positive migrant patients with pulmonary TB were included. Univariate logistic regression was used to analyse the association of variables with treatment delay among migrant patients with TB. A multilogistic regression model was developed to further assess the effect of variables on treatment delay.ResultsOf 314 migrant patients with TB, 65.6% experienced treatment delay (>1 day). Household income level, diagnosis symptom severity, understanding of whether TB is curable or not and knowledge about the free TB treatment policy are factors significantly associated with treatment delay.ConclusionsEconomic status and knowledge about TB are key barriers to accessing TB treatment. An integrated policy of carrying out TB-related health education and publicising the free TB treatment policy among migrants is needed. Health insurance schemes for migrants should be modified to make them transferrable and pro-poor.