bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of Life Prediction Method of Turbine Blade Using the Theory of Critical Distance
Authors: Nakahara Tetsuya , Ueda Yusuke , Nakamura Hiroshi 
Published: December 2013

Gas turbine blades mounted dovetail root are subjected to high centrifugal loads and gas forces. This situation causes low cycle fatigue (LCF). Recently, rotating speed and temperature of turbine rotor become higher in order to improve engine performance. To achieve this, it is required to evaluate accurate turbine blade’s LCF life of the contact surface between the blade dovetail root and the disk. However, the estimated blade lives using the peak stress calculated by finite element analysis (FEA) are much shorter than actual life because the stress at contact surface is excessively high. As a result, the blades are designed conservative and the blade’s weight tends to be heavy. Therefore, a more accurate evaluation methodology needs to be established.
This study investigates the method to estimate the fatigue strength of dovetail using the theory of critical distance. The theory assumes that fatigue failures would occur due to the representative stress within a specific distance from stress concentration point. Fatigue tests and FEA for the turbine blade dovetail were conducted respectively in this research. The tests were carried out using single crystal nickel-based turbine blades at 600 °C and the fracture lives of dovetail were obtained. FEA was conducted to obtain the stress distributions at dovetail contact surface under testing condition. In this study, the critical distances of the single crystal nickel based alloy were obtained from the notched bar fatigue tests and FEA. Using these results and the theory of critical distance, fatigue lives of dovetail were obtained more accurately.
Thrust Control of Small Turbojet Engines Using Fuzzy Logic: Design and Experimental Validation
Authors: Amirante Riccardo , Catalano Luciano Andrea , Tamburrano Paolo 
Published: December 2013

The aim of this paper is to propose an effective technique which employs a proportional-integral Fuzzy logic controller for the thrust regulation of small scale turbojet engines, capable of ensuring high performance in terms of response speed, precision and stability. Fuzzy rules have been chosen by logical deduction and some specific parameters of the closed loop control have been optimized using a numerical simulator, so as to achieve rapidity and stability of response, as well as absence of overshoots. The proposed Fuzzy logic controller has been tested on the Pegasus MK3 microturbine: the high response speed and precision of the proposed thrust control, revealed by the simulations, have been confirmed by several experimental tests with step response. Its stability has been demonstrated by means of the frequency response analysis of the system.
The proposed thrust control technique has general validity and can be applied to any small-scale turbojet engine, as well as to microturbines for electricity production, provided that thrust being substituted with the net mechanical power.
A Computational Investigation of Syngas Substitution Effects on the Combustion Characteristics for a Micro Gas Turbine
Authors: Liu Chi-Rong , Shih Hsin-Yi 
Published: December 2013

The aim of this study is to investigate the effects of syngas substitution on combustion characteristics for a micro gas turbine. For syngas combustion, the ratio of hydrogen and carbon monoxide is varied depending on the process techniques and it could be critical for gas turbine combustion applications. The combustion characteristics of syngas are quite different from natural gas, for example, the flame speed of hydrogen is higher than that of natural gas, but the flame speed of carbon monoxide is lower. In order to understand the performance differences between syngas fuel and natural gas, the combustion and emission characteristics of a can type combustor were investigated with model simulations using the commercial code STAR-CD, where a three-dimensional compressible k-ε model for turbulent flows and presumed probability density function for chemical process between methane/syngas/air mixtures were constructed.
For the fuel injection velocity of 60 m/s and using hydrogen-rich (H2/CO = 80/20) syngas, the high temperature regions are separated and close to the sides of the combustor with some syngas fuel substituted for methane, but the high temperature zones move back to the core region of the combustor by substituting more syngas fuel. The CO2 and NOx emissions are decreased with 10% methane substituted by syngas, but increased with decreasing methane percentages. The detailed flame structures, distributions of flame temperature and flow velocity, and gas emissions of the combustor were presented and compared by using syngas composition and methane percentage of blended fuel mixture as the parameters. The exit temperature profiles and pattern factor were also discussed. Before syngas fuels are used as an alternative fuel for the micro gas turbine, further experimental testing are needed as the CFD modeling results provide a guidance for the improved designs of the combustor.
Unsteady Performance Prediction of a Single Entry Mixed Flow Turbine Using 1-D Gas Dynamic Code Extended With Meanline Model
Authors: Chiong Meng Soon , Rajoo Srithar , Romagnoli Alessandro , Martinez-Botas Ricardo 
Published: December 2013

Turbochargers are widely regarded as one of the most promising enabling technology for engine downsizing, in the aim to achieve better specific fuel consumption, thermal efficiency and most importantly carbon reduction. The increasing demand for higher quality engine-turbocharger matching, leads to the development of computational models capable of predicting the unsteady behaviour of a turbocharger turbine when subjected to pulsating inlet flow. Due to the wide range of engine loads and speed variations, an automotive turbocharger turbine model must be able to render all the frequency range of a typical exhaust pulse flow. A purely one-dimensional (1-D) turbine model is capable of good unsteady swallowing capacity prediction, provided it is accurately validated. However, the unsteady turbine power evaluation still heavily relies on the quasi-steady assumption. On the other hand, meanline model is capable of resolving the turbine work output but it is limited to steady state flow due to its zero dimensional nature.
This paper explores an alternative methodology to realize turbine unsteady power prediction in 1-D by integrating these two independent modelling methods. A single entry mixed-flow turbine is first modelled using 1-D gas dynamic method to solve the unsteady flow propagation in turbine volute while the instantaneous turbine power is subsequently evaluated using a mean-line model. The key in the effectiveness of this methodology relies on the synchronization of the flow information with different time-scales. In addition to the turbine performance parameters, the common level of unsteadiness was also compared based on the Strouhal number evaluations. Comparison of the quasi-steady assumption using the experiment results was made in order to further understand the strength and weaknesses of corresponding method in unsteady turbine performance prediction. The outcomes of the simulation showed a good agreement in the shape and trend profile for the instantaneous turbine power. Meanwhile the predicted cycle-averaged value indicates a positive potential of the current turbine model to be expanded to a whole engine simulation after few minor improvements.
Clinical and Bacteriological Efficacy of Rifampin-Streptomycin Combination for Two Weeks followed by Rifampin and Clarithromycin for Six Weeks for Treatment of Mycobacterium ulcerans Disease
Authors: Phillips Richard O. , Sarfo Fred S. , Abass Mohammed K. , Abotsi Justice , Wilson Tuah , Forson Mark , Amoako Yaw A. , Thompson William , Asiedu Kingsley , Wansbrough-Jones Mark 
Published: December 2013

ABSTRACT

Buruli ulcer, an ulcerating skin disease caused by
Mycobacterium ulcerans
infection, is common in tropical areas of western Africa. We determined the clinical and microbiological responses to administration of rifampin and streptomycin for 2 weeks followed by administration of rifampin and clarithromycin for 6 weeks in 43 patients with small laboratory-confirmed Buruli lesions and monitored for recurrence-free healing. Bacterial load in tissue samples before and after treatment for 6 and 12 weeks was monitored by semiquantitative culture. The success rate was 93%, and there was no recurrence after a 12-month follow-up. Eight percent had a positive culture 4 weeks after antibiotic treatment, but their lesions went on to heal. The findings indicate that rifampin and clarithromycin can replace rifampin and streptomycin for the continuation phase after rifampin and streptomycin administration for 2 weeks without any apparent loss of efficacy.
A Fire-Risk-Breakdown System for Electrical Power Lines in the North of Brazil
Authors: França Gutemberg Borges , Oliveira Antonio Nascimento de , Paiva Célia Maria , Peres Leonardo de Faria , Silva Michael Bezerra da , Oliveira Luciana Maria Temponi de 
Published: December 2013

AbstractAnthropogenic or spontaneous fires (hotspots) are the main causes of unexpected breakdowns of electrical power lines in the northern region of Brazil. This research has tested, adapted, and implemented a preoperational system aiming to prevent electrical breakdowns for 382 km of electrical transmission lines in the state of Maranhão. The breakdown electrical fire risk is based on a combination of three variables: 1) the fire risk index, 2) the remotely sensed hotspot presence in the vicinity of electrical power lines, and 3) the vegetation stage. These variables are converted into Boolean variables, and their combination will classify the electrical fire risk as extreme, high, medium, low, or null. In regard to the system input variables, the fire risk index carries the highest representativeness in composition value of the breakdown electrical fire risk. Therefore, the results of two fire risk indices, calculated on the basis of the (a) Monte Alegre and (b) Angstrom methods, are presented and discussed. The validation of the fire risk indices is based on six categorical statistics (with the obtained final values also indicated in parentheses for the Monte Alegre and Angstrom methods, respectively): accuracy (0.91, 0.92), bias (1.05, 1.06), probability of detection (0.98, 0.99), false-alarm ratio (0.07, 0.07), probability of false detection (0.90, 0.80), and threat score (0.91, 0.92). The system presented here may be used as a tool within the electrical sector to prevent and respond to sudden electrical power line breakdowns.
Influence of Surface Observations in Mesoscale Data Assimilation Using an Ensemble Kalman Filter
Authors: Ha So-Young , Snyder Chris 
Published: December 2013

Abstract
The assimilation of surface observations using an ensemble Kalman filter (EnKF) approach was successfully performed in the Advanced Research version of the Weather Research and Forecasting Model (WRF) coupled with the Data Assimilation Research Testbed (DART) system. The mesoscale cycling experiment for the continuous ensemble data assimilation was verified against independent surface mesonet observations and demonstrated the positive impact on short-range forecasts over the contiguous U.S. (CONUS) domain throughout the month-long period of June 2008. The EnKF assimilation of surface observations was found useful for systematically improving the simulation of the depth and the structure of the planetary boundary layer (PBL) and the reduction of surface bias errors. These benefits were extended above PBL and resulted in a better precipitation forecast for up to 12 h. With the careful specification of observation errors, not only the reliability of the ensemble system but also the quality of the following forecast was improved, especially in moisture. In this retrospective case study of a squall line, assimilation of surface observations produced analysis increments consistent with the structure and dynamics of the boundary layer. As a result, it enhanced the horizontal gradient of temperature and moisture across the frontal system to provide a favorable condition for the convective initiation and the following heavy rainfall prediction in the Oklahoma Panhandle. Even with the assimilation of upper-level observations, the analysis without the assimilation of surface observations simulated a surface cold front that was much weaker and slower than observed.
Phosphodiesterases 3 and 5 express activity in the trigeminal ganglion and co-localize with calcitonin gene-related peptide
Authors: Nordgaard Julie C , Kruse Lars S , Møller Morten , Kruuse Christina 
Published: December 2013

Background Understanding of the neuropathology leading to migraine pain has centered on either a vascular or neuronal origin. Sildenafil, a specific inhibitor of phosphodiesterase 5 (PDE5), induces migraine-like headache in a human headache model without concomitant artery dilation. The presence and activity of PDE3 and PDE5 is known in cerebral arteries. However, the presence in the neuronal part of the trigeminovascular pathway, i.e. the trigeminal ganglion and the possible co-localization with calcitonin gene-related peptide (CGRP), is not known. Methods Rat trigeminal ganglia were isolated and immunohistochemistry and in situ hybridization was applied. Evaluations of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) hydrolysis were performed using scintillation proximity assays. Results PDE3 and PDE5 were present and active in the trigeminal ganglia. A subset of PDE3- and PDE5-positive neurons contained CGRP. In contrast to cGMP, both sildenafil and cilostazol influenced cAMP hydrolysis. Interpretation Sildenafil may exert its effect on the neuronal part of the migraine pain pathway. In addition to the effects on cGMP signaling, sildenafil may indirectly affect cAMP signaling in the trigeminal ganglion. This result may suggest a common cAMP-related pathway for sildenafil, cilostazol, and CGRP in eliciting migraine pain.
Piercing Brightness as an Exploration of the An-archic Imaginary (in conversation with Mark Bartlett)
Authors: Dawood Shezad 
Published: December 2013

Over the summer of 2011, Shezad Dawood went into production on his first feature film: Piercing Brightness, in Preston, Lancashire, in the North-West of England, after two years of research in the city, and in wider networks and archives suggested by this initial research. Interested in any case in the interplay between existing and self-created archives, for the artist the project became a way to explore the hybrid and allegorical potential of overlapping different film and video formats and different sets of meanings. As an additional layer, and based on Dawood’s interest in how artist’s film was and might be read between cinema and gallery, Dawood also made two additional ‘cuts’ of Piercing Brightness: Trailer, a 15-minute version for gallery installation (that plays with the semantics of cinema, yet altering and transferring them to the gallery), and a special 40-minute version, only to be performed with a live score by Acid Mothers Temple, or Alexander Tucker’s Decompressed Orchestra (playing with Dawood’s interest in both expanded cinema and improvised music). These approaches are further interrogated and discussed in the following dialogue between Dawood, and academic and art/film historian Mark Bartlett, who became a regular interlocutor of Dawood’s in the lead-up to and over the course of the production. Their ongoing conversation looks at the concept of an an-archive, in relation to Foucault’s citation of Borges: ‘alter-taxonomy’ in relation to the overarching schemata of Piercing Brightness, presented here as a series of image grids.
Galectin-3: its role in asthma and potential as an anti-inflammatory target
Authors: Gao Peng , Simpson Jodie L , Zhang Jie , Gibson Peter G 
Published: December 2013

AbstractGalectins constitute an evolutionary conserved family that bind to β-galactosides. Increasing evidence shows that galectins are involved in many fundamental biological processes such as cellular communication, inflammation, differentiation and apoptosis. Changes in galectin-3 (Gal-3) expression are commonly seen in cancer and pre-cancerous conditions, and Gal-3 may be involved in the regulation of diverse cancer cell activities that contribute to tumourigenesis, cancer progression and metastasis. In addition, Gal-3 is a pro-inflammatory regulator in rheumatoid arthritis. Gal-3 has been shown to be involved in many aspects in allergic inflammation, such as eosinophil recruitment, airway remodeling, development of a Th2 phenotype as well as increased expression of inflammatory mediators. In anin vivomodel it was shown that bronchoalveolar lavage (BAL) fluid from ovalbumin-challenged mice contained significantly higher levels of Gal-3 compared to control mice. The molecular mechanisms of Gal-3 in human asthma have not been fully elucidated. This review will focus on what is known about the Gal-3 and its role in the pathophysiological mechanisms of asthma to evaluate the potential of Gal-3 as a biomarker and therapeutic target of asthma.
Combination therapy of infliximab and thalidomide for refractory entero-Behcet's disease: a case report
Authors: Li Yue , Han Zelong , Wang Xianfei , Mo Zhihui , Zhang Wei , Li Aimin , Liu Side 
Published: December 2013

Abstract

Background
Behcet's disease (BD) is a systemic inflammatory disease with the histopathological features of leukocytoclastic vasculitis that affects nearly all organs and systems. When it involves the intestine, it is called entero-Behcet's disease (entero-BD).

Case presentation
Here we described a 23-year-old man with entero-BD refractory to conventional therapies who responded well to the combination therapy of infliximab, an anti-tumor-necrosis-factor (TNF)-alpha antibody, and thalidomide. After combination treatment, the patient’s symptoms improved greatly and his Crohn's Disease Activity Index (CDAI) score decreased from 344 to 52 points, accompanied by a body weight increase from 53 kg to 64 kg. A follow-up endoscopy performed 10 weeks after the treatment showed significant improvement and the patient's multiple ulcers had healed well.

Conclusion
The combination therapy of infliximab and thalidomide appears to be clinically effective in a patient with refractory entero-BD. However, further studies need to be performed to evaluate the efficacy of this combination therapy.
Enhanced membrane protein expression by engineering increased intracellular membrane production
Authors: Guerfal Mouna , Claes Katrien , Knittelfelder Oskar , De Rycke Riet , Kohlwein Sepp D , Callewaert Nico 
Published: December 2013

Abstract

Background
Membrane protein research is frequently hampered by the low natural abundance of these proteins in cells and typically relies on recombinant gene expression. Different expression systems, like mammalian cells, insect cells, bacteria and yeast are being used, but very few research efforts have been directed towards specific host cell customization for enhanced expression of membrane proteins. Here we show that by increasing the intracellular membrane production by interfering with a key enzymatic step of lipid synthesis, enhanced expression of membrane proteins in yeast is achieved.

Results
We engineered the oleotrophic yeast, Yarrowia lipolytica, by deleting the phosphatidic acid phosphatase, PAH1, which led to massive proliferation of endoplasmic reticulum (ER) membranes. For all eight tested representatives of different integral membrane protein families, we obtained enhanced protein accumulation levels and in some cases enhanced proteolytic integrity in the ∆pah1 strain. We analysed the adenosine A2AR G-protein coupled receptor case in more detail and found that concomitant induction of the unfolded protein response in the ∆pah1 strain enhanced the specific ligand binding activity of the receptor. These data indicate an improved quality control mechanism for membrane proteins accumulating in yeast cells with proliferated ER.

Conclusions
We conclude that redirecting the metabolic flux of fatty acids away from triacylglycerol- and sterylester-storage towards membrane phospholipid synthesis by PAH1 gene inactivation, provides a valuable approach to enhance eukaryotic membrane protein production. Complementary to this improvement in membrane protein quantity, UPR co-induction further enhances the quality of the membrane protein in terms of its proper folding and biological activity. Importantly, since these pathways are conserved in all eukaryotes, it will be of interest to investigate similar engineering approaches in other cell types of biotechnological interest, such as insect cells and mammalian cells.
Epimutation profiling in Beckwith-Wiedemann syndrome: relationship with assisted reproductive technology
Authors: Tee Louise , Lim Derek HK , Dias Renuka P , Baudement Marie-Odile , Slater Amy A , Kirby Gail , Hancocks Tom , Stewart Helen , Hardy Carol , Macdonald Fiona , Maher Eamonn R 
Published: December 2013

Abstract

Background
Beckwith-Wiedemann syndrome (BWS) is a congenital overgrowth disorder associated with abnormalities in 11p15.5 imprinted genes. The most common cause is loss of methylation (epimutation) at the imprinting control centre 2 (IC2/KvDMR1). Most IC2 epimutations occur sporadically but an association with conception after assisted reproductive technologies (ART) has been reported. A subgroup of IC2 epimutation cases also harbour epimutations at other imprinting centres (ICs) outside of 11p15.5. We have investigated the relationship between these multiple epimutation cases (ME+), history of ART and clinical phenotype in a cohort of 187 BWS IC2 epimutation patients.

Results
Methylation analysis at PLAGL1, MEST and IGF2R ICs demonstrated an over-representation of patients with abnormally low methylation (8.5%, 12% and 6% respectively). At IGF2R some patients (2%) had gain of methylation but this was also detected in controls. Though there were no significant correlations between the methylation index (MIs) at the three ICs tested, a subset of patients appeared to be susceptible to multiple epimutations (ME+) and 21.2% of ME + patients had been conceived by ART compared to 4.5% (P = 0.0033) without additional epimutations. Methylation array profiling (Illumina Goldengate®) of patients and controls (excluding 11p15.5 loci) demonstrated significant differences between patients and controls. No significant associations were found between aspects of the BWS phenotype and individual epimutations but we describe a case presenting with a post-ART BWS-like phenotype in which molecular analysis demonstrated loss of paternal allele methylation at the 11p15.5 IC1 locus (IC1 regulates imprinting of IGF2 and H19). Loss of paternal allele methylation at the IC1 is the molecular finding associated with Silver-Russell syndrome whereas BWS is associated with gain of maternal allele methylation at IC1. Further analysis demonstrated epimutations at PLAGL1 and MEST consistent with the hypothesis that the presence of multiple epimutations may be of clinical relevance.

Conclusions
These findings suggest that the ME + subgroup of BWS patients are preferentially, but not exclusively, associated with a history of ART and that, though at present, there are no clear epigenotype-phenotype correlations for ME + BWS patients, non-11p15.5 IC epimutations can influence clinical phenotype.