bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Angiographic Coronary Calcification and Plaque Composition in Virtual Histology Intravascular Ultrasound
Authors: AMANO HIDEO , IKEDA TAKANORI , TODA MIKIHITO , OKUBO RYO , YABE TAKAYUKI , KOIKE MAKIKO , SAITO DAIGA , YAMAZAKI JUNICHI
Published: April 2015

Objectives

We assessed the relation between coronary plaque composition and angiographic calcification by using virtual histology intravascular ultrasound (VH‐IVUS).

Background

The plaque vulnerability according to angiographic calcification is unclear.

Methods

Subjects were 140 consecutive patients (145 lesions) undergoing VH‐IVUS before percutaneous coronary intervention. Subjects were divided into 4 groups: no calcification group (n = 27), spotty group (n = 65) that had calcium deposits under 90° in grayscale IVUS, intermediate group (n = 37) had calcium deposits with 90° or more and under 180°, and extensive group (n = 16) had calcium deposits with 180° or more.

Results

The number of VH thin‐cap fibroatheromas in spotty group was significantly larger than no calcification group, intermediate group, and extensive group (0.66 ± 0.71 vs 0.22 ± 0.42 [P < 0.01], 0.32 ± 0.48 [P < 0.05], 0.13 ± 0.34 [P < 0.01], respectively). Spotty group without angiographic calcification had significantly larger %necrotic core than with angiographic calcification (24.5 ± 6.7% vs 19.9 ± 7.2%, P < 0.05). Intermediate group without angiographic calcification had significantly larger necrotic core area than with angiographic calcification (2.5 ± 0.9 mm2 vs 1.7 ± 0.9 mm2, P < 0.05). Extensive group with angiographic calcification had significantly larger %dense calcium than without angiographic calcification (18.3 ± 4.0% vs 13.4 ± 4.4%, P < 0.05).

Conclusions

Lesions with spotty calcification was highly vulnerable in VH‐IVUS. Spotty or intermediate plaque calcification without angiographic calcification was more vulnerable than those with angiographic calcification. Extensive plaque calcification with angiographic calcification had more dense calcium than those without angiographic calcification.
CPUY11018, an azimilide derivative, ameliorates isoproterenol-induced cardiac insufficiency through relieving dysfunctional mitochondria and endoplasmic reticulum
Authors: Li Meng , Tang Yi-Qun , Du Rong-Hui , Shi Fang-Hong , Hussein Humed Khan , Dai De-Zai , Dai Yin
Published: April 2015

Objectives

Deterioration of cardiac performance under stress may be partly mediated by dysfunctional mitochondria and endoplasmic reticulum (ER) that is likely related to an activation of NADPH oxidase (NOX) and an increase in pro-inflammatory factors. We investigated if a new compound CPUY11018 (CPUY) derived from Azimilide could ameliorate the stress impaired cardiac performance.

Methods

Forty-eight male Sprague Dawley rats were randomly divided into six groups and were injected with isoproterenol (ISO, 1 ml/kg, s.c.) for 10 days. Cardiac myocytes and fibroblasts from neonate rats were incubated with ISO. CPUY was employed and compared with apocynin (APO) – an inhibitor of NOX.

Key findings

In ISO-treated group, the compromised haemodynamics and cardiac remodelling were significant with dysfunctional mitochondria indicated by decreased MnSOD and mitochondrial membrane potential, and an enhanced reactive oxygen species genesis. Downregulation of FKBP12.6, CASQ2 and SERCA2a was also remarkable in vivo and in vitro implying an abnormal ER. Upregulated Nox4, p22phox and p47phox were significant, associated with upregulation of Src, IκBβ and NFκB, and downregulation of pAMPK/AMPK and Cx40 in vivo and in vitro. These abnormalities were relieved by CPUY and APO.

Conclusions

CPUY is potential in managing cardiac insufficiency through normalizing mitochondria and ER in the affected heart.
Integrated Second Language Writing Assessment: Why? What? How?
Authors: Plakans Lia
Published: April 2015

Integrated writing assessment has appeared in large‐scale language tests as well as in classrooms focused on building academic language skills in a second language. Their increasing use is accompanied by research to explore the validity and usefulness of these tasks. This article reviews literature on integrated assessment via three questions asked in the assessment process: Why use integrated assessment? What does it tell us about writing? and How should we design such tasks?
The WOR1 5′ untranslated region regulates white‐opaque switching in Candida albicans by reducing translational efficiency
Authors: Guan Zhiyun , Liu Haoping
Published: April 2015

The human fungal pathogen Candida albicans undergoes white‐opaque phenotypic switching, which enhances its adaptation to host niches. Switching is controlled by a transcriptional regulatory network of interlocking feedback loops acting on the transcription of WOR1, the master regulator of white‐opaque switching, but regulation of the network on the translational level is not yet explored. Here, we show that the long 5′ untranslated region of WOR1 regulates the white‐opaque phenotype. Deletion of the WOR1 5′ UTR promotes white‐to‐opaque switching and stabilizes the opaque state. The WOR1 5′ UTR reduces translational efficiency and the association of the transcript with polysomes. Reduced polysome association was observed for additional key regulators of cell fate and morphology with long 5′ UTR as well. Overall, we find a novel regulatory step of white‐opaque switching at the translational level. This translational regulation is implicated for many key regulators of cell fate and morphology in C. albicans.
Food habits of harbor seals (Phoca vitulina richardii) as an indicator of invasive species in San Francisco Bay, California
Authors: Gibble Corinne M. , Harvey James T.
Published: April 2015

The diet of harbor seals (Phoca vitulina richardii) in San Francisco Bay (SFB), California, was determined from July 2007 to July 2008 using prey hard parts recovered from 442 scats collected at five haul‐out sites. Twenty‐two species of fish and one species of crustacean were identified, but harbor seals primarily ate a nonnative invasive species, yellowfin goby (Acanthogobius flavimanus), which increased in dietary importance since the diet was last studied in 1991/1992. Additionally, another nonnative invasive fish species, chameleon goby (Tridentiger trigonocephalus), was found for the first time in the diet of harbor seals in SFB. Harbor seal diet was statistically different between years (1991/1992 and 2007/2008), between the pupping and nonpupping seasons, and between North SFB and South SFB haul‐out locations. The diet of harbor seals was significantly correlated with fish species caught in trawl surveys conducted by the California Department of Fish and Wildlife (CDFW) during the same time periods as this study (2007/2008). Harbor seals currently are influencing the health of the SFB ecosystem in a positive manner by consuming large quantities of nonnative invasive fish species.
Analyzing Complex Negotiations
Authors: Crump Larry
Published: April 2015

Complex negotiations have been conducted for a long time, although until somewhat recently analysts had yet to conceptualize their fundamental nature, their essential elements, and the relationship between these elements. Over the past forty years, however, scholars have gained increasing understanding of the forces that shape negotiation complexity.

In this article, I first review literature that has explored complex negotiations, which is found primarily in negotiation studies, and studies of international negotiation. I then develop a five‐part theoretical framework for analyzing complex negotiations: (1) identification of negotiation architecture, (2) context analysis, (3) process analysis, (4) structural and relational analysis, and (5) decisional analysis. I then demonstrate the utility of this five‐part framework by examining the U.S.–Australia Free Trade negotiations that produced the Australia–U.S. Free Trade Agreement of 2005. Finally, the article closes with some observations on complex negotiations and their analysis.
On the Production of Cognitive Achievement and Gaps in Test Scores
Authors: Creel Michael , Farell Montserrat
Published: April 2015

Accumulation of cognitive achievement is investigated using an indirect production function, a dynamic econometric model and a rich data set. Gaps between scores of black and white children remain constant, narrow, or disappear entirely as children grow older, depending upon the measure and the family structure. Income elasticities are higher for children of black families, and there are differences in elasticities with respect to parents' educational levels. The effects of fathers' and mothers' educational levels differ. Between children of two‐parent families and mother‐only families, there is a gap that is at least as important as the racial gap.
Carotenoid‐enriched transgenic corn delivers bioavailable carotenoids to poultry and protects them against coccidiosis
Authors: Nogareda Carmina , Moreno Jose A. , Angulo Eduardo , Sandmann Gerhard , Portero Manuel , Capell Teresa , Zhu Changfu , Christou Paul
Published: April 2015

Carotenoids are health‐promoting organic molecules that act as antioxidants and essential nutrients. We show that chickens raised on a diet enriched with an engineered corn variety containing very high levels of four key carotenoids (β‐carotene, lycopene, zeaxanthin and lutein) are healthy and accumulate more bioavailable carotenoids in peripheral tissues, muscle, skin and fat, and more retinol in the liver, than birds fed on standard corn diets (including commercial corn supplemented with colour additives). Birds were challenged with the protozoan parasite Eimeria tenella and those on the high‐carotenoid diet grew normally, suffered only mild disease symptoms (diarrhoea, footpad dermatitis and digital ulcers) and had lower faecal oocyst counts than birds on the control diet. Our results demonstrate that carotenoid‐rich corn maintains poultry health and increases the nutritional value of poultry products without the use of feed additives.
Comparison of intratumoral heterogeneity of HER2 expression between primary tumor and multiple organ metastases in gastric cancer: Clinicopathological study of three autopsy cases and one resected case
Authors: Saito Takuya , Kondo Chihiro , Shitara Kohei , Ito Yuichi , Saito Noriko , Ikehara Yuzuru , Yatabe Yasushi , Yamamichi Keigo , Tanaka Hideo , Nakanishi Hayao
Published: April 2015

Intratumoral heterogeneity of HER2 expression in the metastatic foci of HER2‐positive advanced gastric cancer remains unclear. In this study, we compared HER2 expression between primary and metastatic tumors in HER2–positive three autopsied cases and one resected case with multiple organ metastases by immunohistochemistry (IHC) and dual color in situ hybridization (DISH). All four cases judged positive (IHC3+) at the primary tumor tissues showed varying HER2 gene amplification (GA) status. One homogeneously HER2‐positive autopsied case (Case 1) and one intratumorally heterogeneous positive resected case (Case 2) with high GA showed a homogeneous positive staining pattern in all the metastatic foci. One heterogeneously HER2‐positive autopsied case (Case 3) with low GA showed a partially heterogeneous HER2 staining pattern in all the metastatic foci. In contrast, one heterogeneously HER2‐positive autopsied case (Case 4) with equivocal GA showed a completely heterogeneous HER2 staining pattern in the metastatic foci. These results indicate that HER2‐positive gastric cancers with low to high GA at the primary tumor show substantially homogeneous HER2 overexpression in the metastatic foci, whereas HER2‐positive gastric cancers with equivocal GA expressed HER2 heterogeneously within the metastatic tumor, suggesting that metastatic foci of the latter HER2‐positive cases would be potentially resistant to trastuzumab.
Forging Practitioner–Scholar Partnerships
Authors: Perry James L.
Published: April 2015

Perry Podcast Episode
Measuring the efficiency of fen restoration on carabid beetles and vascular plants: a case study from north‐eastern Germany
Authors: Görn Sebastian , Fischer Klaus
Published: April 2015

The aim of the study was to assess the effects of fen rewetting on carabid beetle and vascular plant assemblages within riverine fens along the river Peene in north‐eastern Germany. Drained (silage grassland), rewetted (restored formerly drained silage grassland), and near‐natural (fairly pristine) stands were compared. Eighty‐four beetle species (7,267 individuals) and 135 plant species were recorded. The richness of vascular plant species and the number of endangered species were highest on near‐natural fens. Fourteen years of rewetting did not increase plant species numbers compared with drained fens. For carabid beetles, however, species richness and the number of stenotopic species were highest on rewetted fens. Rewetting caused the replacement of generalist carabids by wetland specialists, but did not provide suitable habitat for specialist fen carabids or for plant species of oligo‐ or mesotrophic fen communities. Therefore, raising the water table on fens with nutrient‐rich, degraded peat was not sufficient for restoring species assemblages of intact fens, although water level was the most important environmental factor separating species assemblages. Our study illustrated that insects and plants may respond differentially to restoration, stressing the need to consider different taxa when assessing the efficiency of fen restoration. Furthermore, species assemblages of intact fens could not be restored within 14 years, highlighting the importance of conserving pristine habitat.
Founders, Finding, Being Found: Women's Wisdom in Teaching and Learning in Theology and Religion
Authors: Hess Lisa M. , Brosmer Mary Pierce , Moore Mary Elizabeth Mullino
Published: April 2015

This is an edited transcript of a conversation between two founding women on the delights and demands of teaching and learning within and beyond traditional institutional life, facilitated by Lisa M. Hess of the journal's Editorial Board. The conscious feminine practices of a women's writing school, Women Writing for (a) Change (Cincinnati, Ohio), created the circle‐container for the sharing of words and wisdom. Narrative, pedagogical, and organizational issues arose as the circle listened and examined the realities of contributing as a woman in higher education, yesterday and today.
Canine orbital rhabdomyosarcoma: a report of 18 cases
Authors: Scott Erin M. , Teixeira Leandro B.C. , Flanders David J. , Dubielzig Richard R. , McLellan Gillian J.
Published: April 2015

Purpose

To describe clinical and pathological features of canine orbital rhabdomyosarcoma (COR).

Methods

Retrospective review of patients with COR from the archives of the Comparative Ocular Pathology Laboratory of Wisconsin and the University of Wisconsin Veterinary Medical Teaching Hospital (1983–2014).

Results

Eighteen cases of COR were identified, all diagnosed in an 8‐year period (2006–2014). Affected dogs were typically young (range 1–8; median 2 years), and both sexes were equally represented. Common clinical signs included exophthalmos (16/18) with dorsolateral deviation of the globe (10/18) and elevation of the nictitans (12/18). Ultrasonography, performed in nine cases, revealed an orbital mass with mixed echogenicity and posterior globe indentation. Advanced imaging, performed in nine cases, demonstrated a soft tissue mass with variable contrast enhancement and lysis of the orbital bones (5/9). Histologically, all tumors were subclassified as embryonal rhabdomyosarcoma. All neoplasms demonstrated positive immunohistochemical labeling for desmin, and 14/18 were positive for skeletal muscle actin. Follow‐up information was available for 15/18 cases. Older dogs, aged 6–8 years, had no clinical signs of recurrence or metastasis 8–13 months postdiagnosis (4/4). Most younger dogs (9/11), aged 1–4 years, were euthanized within 6 months (median 2.5 months) of diagnosis due to recurrence at the surgical site (5/9) and/or metastasis (5/9).

Conclusions

Canine orbital rhabdomyosarcoma is a highly malignant neoplasm in juvenile dogs, but may be amenable to surgical resection in older dogs. This duality in biologic behavior may reflect differences in tissue of origin between juvenile onset tumors and adult onset tumors.
Channel function reconstitution and re‐animation: a single‐channel strategy in the postcrystal age
Authors: Oiki Shigetoshi
Published: April 2015

The most essential properties of ion channels for their physiologically relevant functions are ion‐selective permeation and gating. Among the channel species, the potassium channel is primordial and the most ubiquitous in the biological world, and knowledge of this channel underlies the understanding of features of other ion channels. The strategy applied to studying channels changed dramatically after the crystal structure of the potassium channel was resolved. Given the abundant structural information available, we exploited the bacterial KcsA potassium channel as a simple model channel. In the postcrystal age, there are two effective frameworks with which to decipher the functional codes present in the channel structure, namely reconstitution and re‐animation. Complex channel proteins are decomposed into essential functional components, and well‐examined parts are rebuilt for integrating channel function in the membrane (reconstitution). Permeation and gating are dynamic operations, and one imagines the active channel by breathing life into the ‘frozen’ crystal (re‐animation). Capturing the motion of channels at the single‐molecule level is necessary to characterize the behaviour of functioning channels. Advanced techniques, including diffracted X‐ray tracking, lipid bilayer methods and high‐speed atomic force microscopy, have been used. Here, I present dynamic pictures of the KcsA potassium channel from the submolecular conformational changes to the supramolecular collective behaviour of channels in the membrane. These results form an integrated picture of the active channel and offer insights into the processes underlying the physiological function of the channel in the cell membrane.
A Feasibility Study of the Application of Artificial Intelligence Techniques for Turbomachinery Diagnostics
Authors: Meher-Homji Cyrus B.
Published: April 2015

This paper presents a study into the application of Artificial Intelligence (AI) techniques (specifically Expert Systems) to the problem of turbomachine diagnostics. The diagnostic process is described and a model for computer implementation provided. Some diagnostic examples are provided to explain the methodology. Expert system development is underway at the author’s corporation for incorporation in online monitoring and diagnostic systems.
Digital Controls: A Proven Method of Increasing Reliability and Performance on Gas Turbines
Authors: Bostick Gary W.
Published: April 2015

Many gas turbine users have taken advantage of the latest technology microprocessors to upgrade their turbine controls. The primary advantages include improved performance and fuel savings, increased reliability due to redundant design, and reduced maintenance costs associated with the older designs. Numerous other functions and benefits are derived thru microprocessor application. Control system retrofits have been successfully implemented, completely by the user in coordination with the control system supplier, requiring no special outside engineering or involvement.
A Menu-Driven Block Oriented Programming Language for Digital Fuel Controls
Authors: Rosauer Robert J.
Published: April 2015

Digital gas turbine fuel controls are not easily programmed in either assembly or high level languages. The interface between the controls engineer and the programming methodology is strained at best. This paper presents a language that is menu-driven and block oriented to allow the control designer to generate a user programmable control design.
Design Features of the Bayou Cogeneration Plant
Authors: Ahner David J. , Sheldon Richard C. , Patel Anami S. , Bollinger Joseph M.
Published: April 2015

The Bayou Cogeneration Plant, a joint venture of Big Three Industries and General Electric Co., is located at the Bayport Industrial Complex southeast of Houston, Texas. The plant will begin operation in late 1984, supplying process steam to the existing Big Three industrial facility and power to the Houston Light & Power (HL&P) grid.
Design and Development of the General Electric LM5000 Industrial Package Power Plant
Authors: Casper R. L. , Rucigay J. C.
Published: April 2015

A new 33 MW power generation unit utilizing a proven CF6-50 aircraft-derivative gas generator driving a new power tubine has been designed, manufactured, and packaged by the General Electric Company. This paper describes the development and test of the gas turbine and its integration into a complete package power plant, with emphasis on electric utility and cogeneration applications.
Gas Turbine Heat Recovery Systems: Evaluation Criteria for the Unfired Systems
Authors: Pasha Akber
Published: April 2015

The design of a gas turbine exhaust heat recovery system (HRS) depends upon evaluating various parameters. Basically for an unfired heat recovery system the heat contained in the gas turbine exhaust is fixed and output is determined based on the system’s effectiveness. One of the design objectives is to maximize the output and thus maximize the effectiveness. However, increase in effectiveness will increase required heat transfer surface and thus the cost of the HRS. The increased cost (and benefits) must be evaluated to establish whether the higher effective system is economically justifiable. The evaluation criteria of a heat recovery system involves analysis of various design parameters. This paper presents the general design procedure, the effect of each parameter on the design and basic criteria used to develop the HRS design.
Strain Isolated Ceramic Coatings for Gas Turbine Engines
Authors: Tolokan R. P. , Brady J. B. , Jarrabet G. P.
Published: April 2015

Plasma sprayed ceramic coatings are used in gas turbine engines to improve component temperature capability and cooling air efficiency. Strain isolated ceramic coatings offer improved coating life and increased insulating capability. A low modulus fiber metal strain isolator between ceramic and metal backing acts to reduce the stress on the ceramic during thermal cycling. Strain isolated coatings can tolerate greater ceramic thickness and broader operating conditions than nonstrain isolated coatings when subjected to thermal shock.

Ceramic coatings are durable only within a narrow range of operating conditions. Coating designs should be based on real operating conditions for success. Thermal shock testing is useful for evaluating ceramic coatings if test and sample design are representative of the intended application.
Modular Concept of a Gas Turbine Power Plant
Authors: Rappard A. V. , Wicki A.
Published: April 2015

A modular concept of a power plant has been developed on the basis of a modern 45 MW gas turbine.

The most important aspects of this design concept described in this paper, such as layouts, cooling system and electrical equipment, take into consideration the requirements in different countries. In general, a customer demands short delivery and erection times, quick commissioning and good quality. Examples of plant layout planning, the mechanical equipment drawn upon and the sequence of assembly are outlined.
Development of a Small Gas Turbine Combustor With Airblast Atomizer
Authors: Hoshino A. , Tatsumi T. , Sone H. , Shibata M.
Published: April 2015

Kawasaki Heavy Industries, Ltd. has recently developed the S5 gas turbine at rated output power of 24 KW for use primarily in driving generators.

This paper describes the engineering difficulties we experienced in developing the combustor for the small gas turbine, and its performance characteristics.

Particular difficulties that confronted us in developing the combustor that uses the airblast atomizer are ignition, combustor lean flame out limit and carbon deposit. To work out these problems, we used a “click baffle” in the airblast atomizer, and optimized combustor configuration and air flow distribution as well.
Prediction of Blade Flutter in a Tuned Rotor
Authors: Xu Jianmin , Song Zhaohong
Published: April 2015

This paper is about blade flutter in a tuned rotor. With the aid of the combination of three dimensional structural finite element method, two dimensional aerodynamical finite difference method and strip theory, the quasi-steady models in which two degrees of freedom for a single wing were considered have been extended to multiple degrees of freedom for the whole blade in a tuned rotor. The eigenvalues solved from the blade motion equation have been used to judge whether the system is stable or not. The calculating procedure has been formed and using it the first stage rotating blades of a compressor where flutter had occurred, have been predicted. The numerical flutter boundaries have good agreement with the experimental ones.
A General Expression of Combustion Enthalpy Difference at Constant Temperature of CnHmOl-Air System
Authors: Fu Xun-Quan , Fan Zuo-Min
Published: April 2015

Combustion enthalpy difference at constant temperature is a new kind of thermodynamic property of combustion gases. Its general expressions and its applications to making generalized tables of thermodynamic properties of combustion gases and to calculating complex combustion processes thermodynamically for CnHmOl-air system are given in the paper.
Practical Experience With Closed Cycle Vapor Turbogenerators
Authors: Bronicki L.
Published: April 2015

Originally developed mainly for solar energy utilization, the Ormat Closed Cycle Vapor Turbines were first applied to fossil-fuel on-site power generation in remote locations because of their inherent high reliability and low maintenance characteristics. Latterly, conditions changed and the technology has been reapplied to its original use: e.g. solar ponds, waste heat recovery and moderate temperature geothermal sources. This paper presents the results of actual field experience of operating some 3,500 turbogenerators in various applications.
The Solution of the Thermal Elastic-Plastic Problem of Turbine Disk by the Incremental Finite Element Method
Authors: Jin-Wen Sun , Chang Ouyang , Jing-Yan Fang
Published: April 2015

In this paper, a stress analysis method and a computation program of the solution for the thermal elastic-plastic problem of turbine disk in an aeroengine are presented by incremental finite element method. That method (It is suitable to the axisymmetric disk in the gasturbine, compressor, steam turbine as well) may be used to compute the stress and displacement of turbine disk at its thermal elastic or thermal elastic-plastic stage, its cracking revolving speed and limit load capacity and what part of that enters into the plastic zone first. The method may be used to compute its loading and unloading process, its residual stress and displacement as well. It is important to analyse the strength of the turbine disk and its fracture characteristics.
Further Applications of the Lucas Fan Spray Fuel Injection Combustion System
Authors: Carr E.
Published: April 2015

ASME paper 79-GT-175 presented the design philosophy upon which the Lucas fan spray fuel injection combustion system for small gas turbines is based. Included were results from a system designed for an aircraft Auxiliary Power Unit (APU) and capable of operating with aviation kerosene, gas oil and marine diesel fuels.

Since the publication of the above paper there has been further development of the system and application of the design to a range of engines.

The present paper reviews the design philosophy for fan spray combustion systems and describes its application to a unit for a Remotely Piloted Vehicle (RPV) engine with combustion loadings greater than five times that of the initial application covered by paper 79-GT-175.

The design concept is described together with results from, (a) flow visualisation, (b) testing at combustion loading (ΛSI) values between 6 and 24 kg/s Pa 1·8m3 over a range of air to fuel ratios from 50/1 to 300/1, and (c) light-ups over a range of conditions from sea level static to 15 km at 1.6 Flight Mach No. with fuel fed to various configurations of fuel injector i.e. all six injectors, three equispaced, three grouped together and one only. The fuel used was mainly aviation kerosene with a check at a 290 kW condition using gas oil.
Sintered Alpha Silicon Carbide Ceramics for High Temperature Structural Application: Status Review and Recent Developments
Authors: Storm R. S. , Boecker W. D. G. , McMurtry C. H. , Srinivasan M.
Published: April 2015

The physical properties of sintered alpha silicon carbide are reviewed, including the effect of oxidation at high temperatures. Net shape fabricated components are described which have undergone extensive testing in heat engine applications. Properties of an SiC/TiB2 composite material, which has significantly improved fracture toughness, are presented.
A Rational Efficiency Analysis of Comparisons and Trends in Gas Turbines for Cogeneration
Authors: Stecco Sergio S. , Manfrida Giampaolo
Published: April 2015

The performance of gas turbines in cogeneration is examined by means of a second-law approach. Different cycle parameters, for both simple and regenerative design, are investigated together with different options for process or utility heat production. A reference electric power size of 4 MW is assumed for these comparisons. Results are presented as a set of parameters (electric power index, rational efficiency, coefficient of utilization). A new parameter, named versatility index, effectively indicates the broadness of the design thermal loads which can be handled by a gas turbine plant.
Fuel Deposit Characteristics at Low Velocity
Authors: Szetela E. J. , Giovanetti A. J. , Cohen S.
Published: April 2015

An experimental program has been carried out to characterize the relationship between deposit mass, operating time and temperature in studies of the thermal stability of aviation gas turbine fuel. This information is required by fuel system designers to prevent deposit build-up in fuel system components, thus allowing for more efficient designs. The program has included the design, fabrication, and operation of a novel thermal stability test apparatus for the determination of deposition rates over a range of temperatures and test durations up to several hundred hours.

Experiments were run to determine the rate of deposit formation as a function of temperature in heated stainless steel tubes at low velocity using Jet A fuel. The test tube had an inside diameter of 0.22 cm, a length of 0.91 m, and a flow rate of 0.73 kg/hr. Deposits obtained were often characterized as thick, porous, and non-uniform in nature. Deposit density, based on carbon content was 0.08 g/cm3. Deposit rates of 0.1 to 100 μgC/hr-cm2 were observed at surface temperatures between 400 and 600 K.
Effect of Injector Geometry Variables Upon the Spray Performance of a Plain-Jet Airblast Atomizer
Authors: Shaw S. G. , Jasuja A. K.
Published: April 2015

This paper presents the results of a study into the effect that liquid orifice orientation and scale have upon the drop-size performance of a plain-jet airblast atomizer featuring the injection of multiple liquid jets into a swirling airstream. Tests were conducted on water at near atmospheric pressure and temperature conditions using the well-established laser light scattering technique for spray quality measurements. The results presented in the paper reveal that the angular orientation of the liquid orifice, both in longitudinal and radial directions has a noticeable impact upon the atomization performance and exhibits scope for attaining further worthwhile reductions in drop-size relative to the multiple, transversely injected liquid jet configuration.
A Novel Centrifugal Diffuser Test Device
Authors: Shreeve R. P. , Schulz H. D. , Erwin J. R. , Schumann L.
Published: April 2015

A large scale (2 inch wide test vanes at 50-inch inlet diameter), low speed (100–200 ft/sec) steady flow radial cascade wind tunnel for diffuser studies was designed, built and tested. The apparatus was shown to provide flow angles from radial in the range 58–72 degrees with suitable spanwise profiles. The novel flow angle control mechanism was shown to work but measured flow angles were somewhat smaller than expected. The mechanism for controlling case-wall boundary layer profile did not behave as predicted. Attempts to predict the generated flow both analytically and with computational codes are compared with initial measurements. The low speed apparatus will be used to obtain detailed data for diffuser design and analysis code verification, and to provide experience toward the design of a high speed device.
Development of a New Technology Small Fan Jet Engine
Authors: Boyd D. I.
Published: April 2015

The JT15D Turbofan Engine was created to power fast economical low noise executive jets for the general aviation market and currently powers the Cessna Citation I & II, Mitsubishi Diamond series and the Aerospatiale Corvette. This paper describes a higher thrust more fuel efficient version, the JT15D-5, with electronic fuel control systems and power up to a thrust level of 3200 lb. The Engine and its development program are described, including flight test and customer installations. Development problems and their solutions are covered.
The Use of Lasers in Gas Turbine Manufacturing
Authors: Duvall D. S.
Published: April 2015

The laser is being increasingly used as a manufacturing tool in the fabrication of aircraft gas turbine engine components. Both solid-state pulsed and gas continuous-wave lasers are employed for a variety of manufacturing tasks including welding, cutting, hole drilling, surface alloying, and marking of parts for identification. In these applications, the laser provides increased productivity and reduced cost compared to conventional methods. Examples of specific uses of the laser in gas turbine fabrication are described along with the benefits achieved. Metallurgical effects associated with various laser processes are also discussed.
A Variational Finite Element Method for Solving the Blade-to-Blade Flow in Centrifugal Compressor’s Cascades With Splitter Blades on an Arbitrary Streamsheet of Revolution and a Mathematical Treatment to the Region Behind Cascades
Authors: Yulin Chen , Kangmin Chen , Dangfang Zhang
Published: April 2015

A variational finite element method for solving the blade-to-blade flow in centrifugal compressor’s cascades with splitter blades on an arbitrary streamsheet of revolution is suggested in this paper. At first, the variational principles Ref.(1) is modified, then the variational principle after modification is discretized by eight node isoparametric finite elements to carry out the system of nonlinear algebraic equations for solving the velocity potential function. Finally, the flow field which agrees with Kutta condition and has an region behind the cascade of enough length has been worked out.

In this paper, it has been discovered that when the region behind cascade L3 spreads too long the system of equations might become unsolvable as a suitable exit angle β2 can't be found. The linear relation between the velocity defference of the two side of the trailing edge and the exit angle β2 has been found, it shows the range of linear variation of β2 decreases with the increasing of the length of the region behind cascades, in addition, the linear variational relation between tan⁡β2 and L3 has also been obtained.

The iterative computational method for the flow field with different length L3 is used to get the solution of flow field satisfying Kutta condition and with enough length L3.
Firing Synthetic and Low Grade Fuels in Large Combustion Turbines
Authors: Korosi Alexander , Basler Benno
Published: April 2015

In a recent series of experiments, low grade shale oil, coal-derived and petroleum-based fuels were test-fired in a 35 MW capacity stationary gas turbine equipped with a large combustion chamber. Test results indicated that the machine can satisfactorily be operated with low hydrogen and high nitrogen containing partially refined low grade fuels without causing harmful effects to the turbine or the environment.
Systematic Study of Film Cooling With a Three-Dimensional Calculation Procedure
Authors: Demuren A. O. , Rodi W. , Schönung B.
Published: April 2015

The present paper describes three-dimensional calculations of film cooling by injection from a single row of holes. A systematic study of the influence of different parameters on the cooling effectiveness has been carried out. 27 test cases have been calculated, varying the injection angle (α = 10° / 45° / 90°), the relative spacing (s/D = 1.5/3/5) and the blowing rate (M = 0.5/1/2) for the same main-stream conditions. The governing 3D equations are solved by a finite volume method. The turbulent stresses and heat fluxes are obtained from a k-ε model modified to account for non-isotropic eddy viscosities and diffusivities. Examples of predicted velocity and temperature distributions are presented and compared with available experimental data. For all the test cases, the laterally averaged cooling effectiveness is given. On the whole, the agreement with experiments is fairly good, even though there are discrepancies about details in some of the cases. The influence of the individual parameters on the film cooling effectiveness is predicted correctly in all cases. This influence is discussed in some detail and the parameter combination with the best overall cooling performance is identified.
Design and Development of the PGT 10 Heavy-Duty Advanced Gas Turbine
Authors: Benvenuti E. , Gusso R.
Published: April 2015

The PGT 10, a heavy-duty two shaft industrial gas turbine in the 10,000 to 14,000 HP (7,500 to 10,500 kW) nominal power range has been designed; the prototype unit is in construction, with testing scheduled in 1986.

The main distinctive design features are a high pressure ratio and the capability of regenerative cycle operation, coupled with an uncommon combination of adjustable compressor stator vanes and power turbine nozzles, providing very high flexibility in control of cycle parameters. In association with state of art firing temperatures, simple cycle thermal efficiencies up to 34% can be anticipated, while a 36% efficiency level over the whole power range is possible with coupling to a regenerator.

Reliability and long life of hot parts were pursued through extensive reference to successful heavy-duty turbine experience and careful trade-off between aerodynamic design and implementation of nozzle and blade cooling devices; extensive laboratory model tests have been performed to properly check and calibrate hot part cooling flows and distributions prior to full prototype testing.
Evaluation of Conical Diffuser Performance
Authors: Thakker Ajit
Published: April 2015

Experimental datas were used to observe how the overall picture of the diffuser performance is affected by the presence of two different kind of swirl. The theoretical model considered were Cockrell & Markland (4), Sovran & Klomp (5), and Tyler & Williamson (6). In the case of Sovran & Klomp, the theoretical analysis used was one extended by Thakker (1) to take account of 2-D flow. It was found that the performance of the conical diffusers is best improved for a diffuser of total cone angle of 10 and 20 degrees by optimum Rankine vortex addition, and for cone angle of 30 degree by “solid-body” swirl 3.
A Preliminary Calculation of the Combustion Recirculating Flow Behind Flame-Holders
Authors: Zeng C. F. , Zhao J. X. , Ding Z. T.
Published: April 2015

In this paper the numerical method is adopted to predict the combustion recirculating flow behind flame-holders. A modified k-ε turbulence model and Magnussen’s combustion model are employed. Becouse of the large variation of density in combustion flow field, the influences of variable density have been considered. The results predicted include: the combustion recirculating flow field and the flame spreading; the variation of recirculation length with equivalence ratio, and inlet velocity, etc. All of these are qualitatively good comparing with experimental results.
Performance Analysis of an Indirect Fired Air Turbine Cogeneration System
Authors: Huang Francis F. , Egolfopoulos Fokion
Published: April 2015

A thermodynamic study of an indirect fired air turbine cogeneration system for the production of electricity and process steam has been made. Performance data showing the effect of compressor compression ratio and turbine inlet temperature on fuel utilization efficiency (first law efficiency), electrical to thermal energy ratio (power to heat ratio) and second law efficiency (exergetic efficiency) have been generated. Although fuel utilization efficiency and electrical to thermal energy ratio data do provide some useful information, it is the second law efficiency that provides the optimal design conditions. The performance data contained in this study should be useful to the decision-makers in the selection of optimal parameters at the system design stage of an indirect fired air turbine cogeneration system.
Discussion About Dynamic Simulation Test of an Aero-Engine Control System
Authors: Hua Wu Chi , Ding Fan
Published: April 2015

In this paper, following viewes are expressed: (1). Introduction of partly physical simulation test about aero-engine control systems. (2). Several plans carried out for this test. (3). A real example of digital analogue hybrid partly physical simulation test.
Higher Availability and Efficiency Using On-Line Real Time Diagnostic and Prognostic Systems on Gas Turbine Compressor Trains
Authors: Boyce M. P. , Lam Tom K.
Published: April 2015

High Speed Turbomachinery Systems are getting more complex as they require wide operating ranges as well as higher discharge pressures. Both these facts lead to systems being designed to their most critical stage in both mechanical and aerothermal states. Additionally, the high cost of fuel and downtime requires that the machinery have some type of data acquisition which can diagnose and prognosticate possible consequences before they occur and run the system as efficiently as possible. This paper deals with such a system and enables these goals to be achieved.

Aspects relating to a system developed to monitor three gas turbine reinjection compressor trains on an offshore platform is discussed. Two different types of on-line realtime systems are discussed. One is a highly sophisticated multifunction condition monitoring system. Such a system has been developed for offshore platforms to monitor gas turbine compressor trains. The other on-line system is a dedicated surge control system.
An Approach to Performance Prediction of Gas-Wet Steam Turbo Expanders
Authors: Zhi-Guang Ling , Shu-Lian Li , Yang Fei
Published: April 2015

Means of predicting aerothermodynamic characteristics of turbines and expanders with gas-wet steam working medium and having condensation and release of latent heat of vaporization during expansion process are studied. After discussing the basic relations and fundamental equations of such process, a simple method is suggested on the basis of introducing the concept of replacing the condensing and heat release process thermodynamically by an equivalent polytropic process with an equivalent index.n. By such replacement the usual gas medium calculation program could be used and performance prediction could be easily made. Details of calculation procedures are recommended. The calculated performance of a blast furnace top gas turbo expander by this method shows good agreement with tested results.
Investigation of the Transient Response of a Dual-Rotor System With Intershaft Squeeze Film Damper
Authors: Li Qihan , Hamilton James F.
Published: April 2015

A method is presented for calculating the dynamics of a dual-rotor gas turbine engine equipped with a flexible intershaft squeeze-film damper. The method is based on the functional expansion component synthesis method.

The transient response of the rotor due to a suddenly applied unbalance in the high-pressure turbine under different steady-speed operations is calculated. The damping effects of the intershaft damper and stability of the rotor system are investigated.
Investigation of the Steady-State Response of a Dual-Rotor System With Inter-Shaft Squeeze Film Damper
Authors: Li Qihan , Yan Litang , Hamilton James F.
Published: April 2015

This paper presents an analysis of the steady-state unbalance response of a dual-rotor gas turbine engine with a flexible intershaft squeeze film damper using a simplified transfer matrix method. The simplified transfer matrix method is convenient for the evaluation of the critical speed and response of the rotor system with various supports, shaft coupling, intershaft bearing, etc.

The steady-state unbalance response of the rotor system is calculated for different shaft rotation speeds. The damping effects of an intershaft squeeze film damper with different radial clearances under various levels of rotor unbalance are investigated.
Compressed Air Energy Storage: Plant Integration, Turbomachinery Development
Authors: Nakhamkin M. , Hutchinson F. D. , Stange J. R. , Schainker R. B. , Canova F.
Published: April 2015

Results of engineering and optimization of 25 MW and 50 MW turbomachinery trains for compressed air energy storage (CAES) power plant application are presented. Proposals submitted by equipment suppliers are based on commercially available equipment. Performance data and budget prices indicate that the CAES power plant is one of the most cost effective sources of providing peaking/intermediate power and load management. The paper addresses CAES power plant integration procedure and the specifics of turbomachinery design.
Vibration Characteristics of 50 Hz, 120 MW Gas Turbine
Authors: Okubo Atsuo , Mori Yoshitaka , Nadai Yoshikazu , Kanki Hiroshi
Published: April 2015

This paper describes the vibration analysis technology of MW-701D Gas Turbine which was developed by Mitsubishi Heavy Industries, Ltd. for 50 Hz utilities.

MW-701D is the highest performance gas turbine available with a firing temperature of 1,154°C for base load operation. It is employed by the 1,090 MW combined cycle plant, one of the largest of its kind in the world, and the plant began commercial operation at half of the total capacity of 1,090 MW in December, 1984. The plant was designed to supply base load electric power generation by burning imported liquefied natural gas (LNG) fuel. This paper describes the general description of the combined cycle plant and the vibration characteristics of MW-701D Gas Turbine.
Application of the Rotating Water Table to Nozzle Wake Excitation in Low Pressure Turbines
Authors: Chen Shun
Published: April 2015

The hydraulic analogy was employed in a rotating water table for simulating the compressible two dimensional flow in a low pressure turbine stage. Both steady and unsteady forces were measured directly on a rotating blade in a blade row rotating concentrically with a row of stator vanes. With proper modeling of the simulation, it is shown that the rotating water table can yield results that agree favorably with the analytical predictions and turbine test results. Using this test facility, the effects of axial spacing between rotor and stator rows on the nozzle wake excitation have been investigated for two different stator vane profiles. The water table test results correlate qualitatively with the turbine test data. The cancellation of nozzle passing frequency excitation by off-setting nozzle pitch was demonstrated in the water table and the results compared with both the analytical predictions and the laboratory turbine test results.