bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Turning Limit and Jet Like Profiles in Secondary Flow Field of Axial Turbines
Authors: Kaldellis J. K. , Ktenidis P. D. 
Published: March 2015

The evolution of the secondary flow field in cases of axial turbine bladings is examined in the present work.
Our secondary flow calculation method is successfully used, in an improved form including the complete meridional vorticity transport equation, to predict common viscous flow phenomena in axial turbines, such as high turning of the flow direction and jet-like velocity profiles.
The method used, although close to the parabolized Navier-Stokes approach, preserve several integral approximations thus minimizing the computer time required as compared to equivalent differential approaches. Our method provide fast and reliable tools for industrial applications with results comparable to those obtained by the differential solutions of the Navier-Stokes equations.
Several test cases, covering a wide deflection angle and acceleration ratio range, are analyzed. The results, concerning the secondary flow field, are very encouraging and Justify the choice of using approximate methods to estimate viscous phenomena in axial turbines.
An Experimental Investigation of Heat Transfer in an Orthogonally Rotating Channel Roughened With 45 Degree Criss-Cross Ribs on Two Opposite Walls
Authors: Taslim M. E. , Bondi L. A. , Kercher D. M. 
Published: March 2015

Turbine blade cooling is imperative in advanced aircraft engines. The extremely hot gases that operate within the turbine section require turbine blades to be cooled by a complex cooling circuit. This cooling arrangement increases engine efficiency and ensures blade materials a longer creep life. One principle aspect of the circuit involves serpentine internal cooling passes throughout the core of the blade. Roughening the inside surfaces of these cooling passages with turbulence promoters provides enhanced heat transfer rates from the surface.
The purpose of this investigation was to study the effects of rotation, aspect ratio, and turbulator roughness on heat transfer in these rib-roughened passage. The investigation was performed in an orthogonally rotating setup to simulate the actual rotation of the cooling passages. Single pass channels, roughened on two opposite walls, with turbulators positioned at a 45° angle to the flow, in a criss-cross arrangement, were studied throughout this experiment. The ribs were arranged such that their pitch-to-height ratio remained at a constant value of 10. An aspect ratio of unity was investigated under three different rib blockage ratios (turbulator height/channel hydraulic diameter) of 0.1333, 0.25, and 0.3333. A channel with an aspect ratio of 2 was also investigated for a blockage ratio of 0.25. Air was flown radially outward over a Reynolds number range of 15000 to 50000. Rotation number was varied from 0 to 0.3. Stationary and rotating cases of identical geometries were compared. Results indicate that rotational effects are more pronounced in turbulated passages of high aspect and low blockage ratios for which a steady increase in heat transfer coefficient is observed on the trailing side as rotation number increases while the heat transfer coefficient on the leading side shows a steady decrease with rotation number. However, the all-smooth-wall classical pattern of heat transfer coefficient variation on the leading and trailing sides is not followed for smaller aspect ratios and high blockage ratios when the relative artificial roughness is high.
A Computer Method for Thermal Power Cycle Calculation
Authors: Perz E. 
Published: March 2015

This paper describes a highly flexible computer method for thermodynamic power cycle calculations (PCC). With this method the user can model any cycle scheme by selecting components from a library and connecting them in an appropriate way. The flexibility is not restricted by any predefined cycle schemes.
A power cycle is mathematically represented by a system of algebraic equations. The structure of mathematical cycle models as well as different approaches to set up and solve the resulting equations with computer programs are discussed in the first section.
The second section describes the developed method. The mass and energy balance equations are set up and solved with an semi-parallel algorithm. As input only the cycle’s topology and component parameters must be entered. Information about the calculation sequence and the convergence method can be omitted completely. The example of two simple steam cycles demonstrates the applied technique.
The method requires only a few — if any at all — iterations. Calculation time and storage requirements can be kept low enough to calculate even very complex cycles on personal computers. At the end of the paper input data and results for a complex cycle scheme as it may occur in reality are given to demonstrate the performance finally.
Experience With External Fires in Gas Turbine Installations and Implications for Fire Protection
Authors: Dundas R. E. 
Published: March 2015

This paper summarizes a body of experience with external fires, such as those involving lube oil, liquid fuel, or fuel gas, in gas turbine–generator installations. It then describes one such fire in a sprinklered building, indicating the lack of effectiveness of the sprinklers in controlling the fire and preventing damage to the building. Conclusions are then drawn as to the optimum methods of protecting against such fires.
A concept of using excess–flow check valves in fuel lines, and throughout the lubrication system, for maximum protection from fires and other effects of a fuel or lubrication line break or separation, is described.
Experimental Evaluation of a Low NOx LBG Combustor Using Bypass Air
Authors: Nakata T. , Sato M. , Ninomiya T. , Abe T. , Mandai S. , Sato N. 
Published: March 2015

A 150-MW, 1300°C (1573 K) class gas turbine combustor firing coal-gasified fuel has been designed. Main purpose of the present paper is first to estimate CO and NOx emissions, and second to discuss the low NOx combusion technology burning such a low-BTU gas. The full-scale, atmospheric-pressure combustion tests were conducted over a wide range of conditions using bypass air.
The results are summarized as follows:
(1) A designed combustor has an excellent combustion efficiency of 99.6 percent even when the calorific value of fuel drops to 650 kcal/m3N.
(2) CO and NOx emissions can be estimated by the air ratio in primary combustion zone.
(3) The role of air bypass valve is important for low NOx combustion, and to give stable combustion at lower load conditions.
(4) Ammonia conversion to NOx is minimized with a optimum air ratio in primary combustion zone.
Problems and Use of the Scaling Factors in the Numerical Simulation of Jet Engines
Authors: Torella G. 
Published: March 2015

The possibility of the use of scaling factors in the calculations and in the simulation of gas turbine engines have been considered.
Application of this technique to the simulation of trend analysis, the evaluation of the component maps shifting during the operational life of the engine and the calculation of matrices of influence have been presented.
Moreover, some problems related to the use of scaling factors have been studied and their effects on the engine performance have been presented.
NOx Exhaust Emissions for Gas-Fired Turbine Engines
Authors: Malte P. C. , Bernstein S. , Bahlmann F. , Doelman J. 
Published: March 2015

A database consisting of 18 heavy-duty and aeroderivative gas turbine engine models, fired on natural gas, is evaluated for NOx exhaust emissions with and without water and steam injection. CO exhaust emissions are also considered. Engine baseload power outputs range from 2.9 to 83.5 MW, compressor pressure ratios are from 7.2 to 30.0, and turbine inlet temperatures are from 1150 to 1515K. The engine models are from the late 1970s to the current period, and all use diffusion flame combustors.
Baseload, uncontrolled NOx exhaust emissions, corrected to 15% O2 dry conditions, vary from 67 to 240 ppmv. CO exhaust emissions vary from 7 to 96 ppmv. Except for three low-NOx aero-derivative engines, the uncontrolled NOx exhaust emissions scale with engine pressure ratio and fuel-air ratio. A correlation formula is developed, and discussed relative to formulas in the literature. NOx control by water injection shows a fairly wide band; at a water-to-fuel mass ratio of 0.8, the NOx reduction varies from 58 to 82 percent. Engines with the highest uncontrolled NOx show the largest percentage reduction by water injection. On the other hand, NOx control response with steam injection exhibits less variation across the engine models. The relation of CO to NOx levels and and the response of CO to water and steam injection are examined, though quantitative correlations are not made.
Trypanosoma brucei RRM1 Is a Nuclear RNA-Binding Protein and Modulator of Chromatin Structure
Authors: Naguleswaran Arunasalam , Gunasekera Kapila , Schimanski Bernd , Heller Manfred , Hemphill Andrew , Ochsenreiter Torsten , Roditi Isabel 
Published: March 2015

ABSTRACT

TbRRM1 of
Trypanosoma brucei
is a nucleoprotein that was previously identified in a search for splicing factors in
T. brucei
. We show that TbRRM1 associates with mRNAs and with the auxiliary splicing factor polypyrimidine tract-binding protein 2, but not with components of the core spliceosome. TbRRM1 also interacts with several retrotransposon hot spot (RHS) proteins and histones. RNA immunoprecipitation of a tagged form of TbRRM1 from procyclic (insect) form trypanosomes identified ca. 1,500 transcripts that were enriched and 3,000 transcripts that were underrepresented compared to cellular mRNA. Enriched transcripts encoded RNA-binding proteins, including TbRRM1 itself, several RHS transcripts, mRNAs with long coding regions, and a high proportion of stage-regulated mRNAs that are more highly expressed in bloodstream forms. Transcripts encoding ribosomal proteins, other factors involved in translation, and procyclic-specific transcripts were underrepresented. Knockdown of TbRRM1 by RNA interference caused widespread changes in mRNA abundance, but these changes did not correlate with the binding of the protein to transcripts, and most splice sites were unchanged, negating a general role for TbRRM1 in splice site selection. When changes in mRNA abundance were mapped across the genome, regions with many downregulated mRNAs were identified. Two regions were analyzed by chromatin immunoprecipitation, both of which exhibited increases in nucleosome occupancy upon TbRRM1 depletion. In addition, subjecting cells to heat shock resulted in translocation of TbRRM1 to the cytoplasm and compaction of chromatin, consistent with a second role for TbRRM1 in modulating chromatin structure.

IMPORTANCE
Trypanosoma brucei
, the parasite that causes human sleeping sickness, is transmitted by tsetse flies. The parasite progresses through different life cycle stages in its two hosts, altering its pattern of gene expression in the process. In trypanosomes, protein-coding genes are organized as polycistronic units that are processed into monocistronic mRNAs. Since genes in the same unit can be regulated independently of each other, it is believed that gene regulation is essentially posttranscriptional. In this study, we investigated the role of a nuclear RNA-binding protein, TbRRM1, in the insect stage of the parasite. We found that TbRRM1 binds nuclear mRNAs and also affects chromatin status. Reduction of nuclear TbRRM1 by RNA interference or heat shock resulted in chromatin compaction. We propose that TbRRM1 regulates RNA polymerase II-driven gene expression both cotranscriptionally, by facilitating transcription and efficient splicing, and posttranscriptionally, via its interaction with nuclear mRNAs.
Novel Type III Effectors in Pseudomonas aeruginosa
Authors: Burstein David , Satanower Shirley , Simovitch Michal , Belnik Yana , Zehavi Meital , Yerushalmi Gal , Ben-Aroya Shay , Pupko Tal , Banin Ehud 
Published: March 2015

ABSTRACT

Pseudomonas aeruginosa
is a Gram-negative, opportunistic pathogen that causes chronic and acute infections in immunocompromised patients. Most P. aeruginosa strains encode an active type III secretion system (T3SS), utilized by the bacteria to deliver effector proteins from the bacterial cell directly into the cytoplasm of the host cell. Four T3SS effectors have been discovered and extensively studied in P. aeruginosa: ExoT, ExoS, ExoU, and ExoY. This is especially intriguing in light of P. aeruginosa's ability to infect a wide range of hosts. We therefore hypothesized that additional T3SS effectors that have not yet been discovered are encoded in the genome of P. aeruginosa. Here, we applied a machine learning classification algorithm to identify novel P. aeruginosa effectors. In this approach, various types of data are integrated to differentiate effectors from the rest of the open reading frames of the bacterial genome. Due to the lack of a sufficient learning set of positive effectors, our machine learning algorithm integrated genomic information from another Pseudomonas species and utilized dozens of features accounting for various aspects of the effector coding genes and their products. Twelve top-ranking predictions were experimentally tested for T3SS-specific translocation, leading to the discovery of two novel T3SS effectors. We demonstrate that these effectors are not part of the injection structural complex and report initial efforts toward their characterization.

IMPORTANCE
Pseudomonas aeruginosa
uses a type III secretion system (T3SS) to secrete toxic proteins, termed effectors, directly into the cytoplasm of the host cell. The activation of this secretion system is correlated with disease severity and patient death. Compared with many other T3SS-utilizing pathogenic bacteria, P. aeruginosa has a fairly limited arsenal of effectors that have been identified. This is in sharp contrast with the wide range of hosts that this bacterium can infect. The discovery of two novel effectors described here is an important step toward better understanding of the virulence and host evasion mechanisms adopted by this versatile pathogen and may provide novel approaches to treat P. aeruginosa infections.
Simultaneous stent expansion/balloon deflation technique to salvage failed balloon remodeling
Authors: Ladner Travis R , He Lucy , Davis Brandon J , Froehler Michael T , Mocco J 
Published: March 2015

Herniation, with possible embolization, of coils into the parent vessel following aneurysm coiling remains a frequent challenge. For this reason, balloon or stent assisted embolization remains an important technique. Despite the use of balloon remodeling, there are occasions where, on deflation of the balloon, some coils, or even the entire coil mass, may migrate. We report the successful use of a simultaneous adjacent stent deployment bailout technique in order to salvage coil prolapse during balloon remodeling in three patients. Case No 1 was a wide neck left internal carotid artery bifurcation aneurysm, measuring 9 mm×7.9 mm×6 mm with a 5 mm neck. Case No 2 was a complex left superior hypophyseal artery aneurysm, measuring 5.3 mm×4 mm×5 mm with a 2.9 mm neck. Case No 3 was a ruptured right posterior communicating artery aneurysm, measuring 4 mm×4 mm×4.5 mm with a 4 mm neck. This technique successfully returned the prolapsed coil mass into the aneurysm sac in all cases without procedural complications. The closed cell design of the Enterprise VRD (Codman and Shurtleff Inc, Raynham, Massachusetts, USA) makes it ideal for this bailout technique, by allowing the use of an 0.021 inch delivery catheter (necessary for simultaneous access) and by avoiding the possibility of an open cell strut getting caught on the deflated balloon. We hope this technique will prove useful to readers who may find themselves in a similar predicament.
The efficacy of sodium bicarbonate in preventing contrast-induced nephropathy in patients with pre-existing renal insufficiency: a meta-analysis
Authors: Zhang Bin , Liang Long , Chen Wenbo , Liang Changhong , Zhang Shuixing 
Published: March 2015

ObjectiveThe aim of this meta-analysis was to explore the efficacy of sodium bicarbonate in preventing contrast-induced nephropathy (CIN).MethodsWe searched PubMed, Medline and the Cochrane Library from 1 January 2004 to 1 August 2014. The effect estimate was expressed as a pooled OR with 95% CI, using the fixed-effects or random-effects model.Results20 randomised controlled trials (n=4280) were identified. Hydration with sodium bicarbonate was associated with a significant decrease in CIN among patients with pre-existing renal insufficiency (OR 0.67, 95% CI 0.47 to 0.96; p=0.027). However, moderate heterogeneity was noted across trials (I2=48%; p=0.008). Subgroup analyses indicated a better effect of sodium bicarbonate in studies using low-osmolar (OR 0.59, 95% CI 0.37 to 0.93; p=0.024) compared with iso-osmolar contrast agents (OR 0.76, 95% CI 0.43 to 1.34; p=0.351). The odds of CIN with sodium bicarbonate were lower in studies including only patients undergoing emergency (OR 0.16, 95% CI 0.05 to 0.51; p=0.002) compared with elective procedures (OR 0.76, 95% CI 0.54 to 1.06; p=0.105). Sodium bicarbonate was more beneficial in patients given a bolus injection before procedures (OR 0.15, 95% CI 0.04 to 0.54; p=0.004) compared with continuous infusion (OR 0.75, 95% CI 0.53 to 1.05; p=0.091). Sodium bicarbonate plus N-acetylcysteine (OR 0.17, 95% CI 0.04 to 0.79; p=0.024) was better than sodium bicarbonate alone (OR 0.71, 95% CI 0.48 to 1.03; p=0.071). The effect of sodium bicarbonate was considered greater in papers published before (OR 0.19, 95% CI 0.09 to 0.41; p=0.000) compared with after 2008 (OR 0.85, 95% CI 0.62 to 1.16; p=0.302). However, no significant differences were found in mortality (OR 0.69, 95% CI 0.36 to 1.32; p=0.263) or requirement for dialysis (OR 1.08, 95% CI 0.52 to 2.25; p=0.841).ConclusionsSodium bicarbonate is effective in preventing CIN among patients with pre-existing renal insufficiency. However, it fails to lower the risks of dialysis and mortality and therefore cannot improve the clinical prognosis of patients with CIN.
Childhood conscientiousness predicts the social gradient of smoking in adulthood: a life course analysis
Authors: Pluess Michael , Bartley Mel 
Published: March 2015

Background and aimsThe social gradient in smoking is well known, with higher rates among those in less advantaged socioeconomic position. Some recent research has reported that personality characteristics partly explain this gradient. However, the majority of existing work is limited by cross-sectional designs unsuitable to determine whether differences in conscientiousness are a predictor or a product of social inequalities. Adopting a life course perspective, we investigated in the current paper the influence of conscientiousness in early and mid-life on the social gradient in smoking and the role of potential confounding factors in a large longitudinal cohort study.MethodsUsing data from the 1958 National Child Development Study, we examined the extent to which two measures of conscientiousness, one assessed with a personality questionnaire at age 50 and one derived from three related items at 16 years in childhood, explained the social gradient of smoking at age 50 by comparing nested logistic regression models that included social class at birth, cognitive ability, attention and conduct problems at age 7, and educational qualification.ResultsChildhood conscientiousness was a significant predictor of smoking at 50 years (OR=0.86, CI (95%) 0.84 to 0.88), explaining 5.0% of the social gradient independent of all other variables. Childhood conscientiousness was a stronger predictor than adult conscientiousness, statistically accounting for the observed direct association of adult conscientiousness with smoking.ConclusionsConscientiousness may be a predictor rather than a product of social differences in smoking. Inclusion of personality measures and adoption of a life course perspective add significantly to our understanding of health inequalities.
The Coordinated Actions of TIM-3 on Cancer and Myeloid Cells in the Regulation of Tumorigenicity and Clinical Prognosis in Clear Cell Renal Cell Carcinomas
Authors: Komohara Yoshihiro , Morita Tomoko , Annan Dorcas A. , Horlad Hasita , Ohnishi Koji , Yamada Sohsuke , Nakayama Toshiyuki , Kitada Shohei , Suzu Shinya , Kinoshita Ichiro , Dosaka-Akita Hirotoshi , Akashi Koichi , Takeya Motohiro , Jinushi Masahisa 
Published: March 2015

Abstract
Clear cell renal cell carcinoma (ccRCC) is one of most common cancers in urogenital organs. Although recent experimental and clinical studies have shown the immunogenic properties of ccRCC as illustrated by the clinical sensitivities to various immunotherapies, the detailed immunoregulatory machineries governing the tumorigenicity of human ccRCC remain largely obscure. In this study, we demonstrated the clinical significance and functional relevance of T-cell immunoglobulin and mucin domain-containing molecule-3 (TIM-3) expressed on tumor cells and myeloid cells in patients with ccRCC. TIM-3 expression was detected on cancer cells and CD204+ tumor-associated macrophages (TAM), and higher expression level of TIM-3 was positively correlated with shorter progression-free survival (PFS) in patients with ccRCC. We found that TIM-3 expression was detected on a large number of tumors, and there was significant correlation between an increased number of TAMs and high expression level of TIM-3 in patients with ccRCC. Furthermore, TIM-3 rendered RCC cells with the ability to induce resistance to sunitinib and mTOR inhibitors, the standard regimen for patients with ccRCC, as well as stem cell activities. TIM-3 expression was induced on CD14+ monocytes upon long-term stimulation with RCC cells, and TIM-3–expressing myeloid cells play a critical role in augmenting tumorigenic activities of TIM-3-negative RCC cells. More importantly, treatment with anti–TIM-3 mAb suppressed its tumorigenic effects in in vitro and in vivo settings. These findings indicate the coordinated action of TIM-3 in cancer cells and in myeloid cells regulates the tumorigenicity of human RCC. Cancer Immunol Res; 3(9); 999–1007. ©2015 AACR.