bluuebunny/crossref_metadata_2025 huggingface dataset:
Japanese familial case of myoclonus–dystonia syndrome with a splicing mutation in SGCE
Authors: Wada Takahito , Takano Kyoko , Tsurusaki Yoshinori , Miyake Noriko , Nakashima Mitsuko , Saitsu Hirotomo , Matsumoto Naomichi , Osaka Hitoshi
Published: April 2015

Myoclonus–dystonia syndrome (MDS) is a rare autosomal‐dominant movement disorder characterized by brief, frequently alcohol‐responsive myoclonic jerks that begin in childhood or early adolescence, caused by mutations in the ε‐sarcoglycan gene (SGCE). The patient was a 6‐year‐old boy. At 2 years 8 months, he had abnormal movement when he ran due to dystonia of his left leg. At 3 years 5 months, he exhibited dystonia and myoclonic movement of his arms when eating. Myoclonus was likely to develop when he felt anxiety or exhaustion. Genomic DNA showed a heterozygous mutation in SGCE (c.109 + 1 G > T). His father and uncle with the same mutation also experienced milder dystonia or myoclonic movements. SGCE mutation can cause a broad range of clinical symptoms between and within families. We should consider MDS as a differential diagnosis for patients with paroxysmal walking abnormalities and/or myoclonic movements.
Are regulatory agencies independent in practice? Evidence from board members in Spain
Authors: Fernández‐i‐Marín Xavier , Jordana Jacint , Bianculli Andrea C.
Published: April 2015

Are the board members of regulatory agencies (regulators), taken as a particular cluster within the public sphere, independent of elected politicians and tenured bureaucrats? How can we assess their independence in practice, beyond formal rules? To address these questions, this paper delves into two key dimensions: board members' social connections and their security of tenure in office. Firstly, we focus on regulators' identity as policy adjudicators and examine their political and administrative relations. In doing so, we expect to understand better how regulators' social and political situations may influence their behavior. Secondly, we assess their political vulnerability through political cycles in order to measure their de facto independence over time. Additionally, variations in these two dimensions are compared with respect to the effect of different de jure appointment rules. We contrast these expectations with the empirical evaluation of board members of regulatory agencies in Spain (1979–2010). Thus, we confirm that regulators who have an administrative profile are more vulnerable to political changes than those with political ties, while appointment rules have an influence on their political vulnerability.
Property Rights, Governance, and Economic Development
Authors: Auerbach Jan U. , Azariadis Costas
Published: April 2015

In this review article we give an intuitive account of why good institutions in general, and secure property rights in particular, matter for economic growth and development. We also discuss implications for good governance, defined as the efficient provision of property rights and other aspects of governance. Finally, we briefly touch on political institutions that might be conducive to good governance and thus economic development.
Non‐Homothetic Multisector Growth Models
Authors: Jensen Bjarne S. , Lehmijoki Ulla , Rovenskaya Elena
Published: April 2015

Multisector growth (MSG) models are dynamic versions of computable general equilibrium (CGE) models. Non‐homothetic preference (utility) functions are required for the evolution of factor allocations and industrial structures in accordance with consumption expenditure patterns implied by the non‐unitary income elasticities observed in all budget data since Engel in the 1850s. But comparative static general equilibrium solutions and particularly solving the dynamics of MSG models require explicit specifications of all demand and cost (price) functions. On the demand side, the constant differences of elasticity of substitution (CDES) non‐homothetic indirect utility functions and Roy's identity provide the explicit Marshallian demand functions and budget shares. Sectorial constant elasticity of substitution (CES) cost functions and Shephard's lemma provide the explicit relative commodity price functions and the sectorial cost shares and capital–labor ratios. Walrasian equilibria are given by one equation and the multisector dynamics by three differential equations. Benchmark solutions are given for three cost regimes of a 10‐sector MSG model. History patterns of industrial/allocational evolutions are recognized.
Credit in Times of Stress: Lessons from Latin America during the Global Financial Crisis
Authors: Montoro Carlos , Rojas‐Suarez Liliana
Published: April 2015

The 2008–2009 global financial crisis disrupted the provision of credit in Latin America less than in previous crises. This paper tests whether specific characteristics at both the bank and country levels at the onset of the global crisis contributed to the behavior of real credit growth in this region during the crisis. As shown, financial soundness characteristics of Latin American banks, such as capitalization, liquidity, and bank efficiency in the pre‐crisis period, played a role in explaining the dynamics of real credit during the crisis. We also found that foreign banks and banks that had expanded credit growth more before the crisis were also those that cut credit the most. Among country‐specific characteristics, we found evidence that balance sheet measures such as the economy's overall currency mismatches and external debt ratios (measuring either total debt or short‐term debt) were key variables in explaining credit growth resilience.
Comparison of the diuretic effect of furosemide by different methods of administration in healthy dogs
Authors: Harada Kayoko , Ukai Yoshimi , Kanakubo Kayo , Yamano Shigeki , Lee Junseok , Kurosawa Tsumugi Anne , Uechi Masami
Published: April 2015

Objective

To compare the diuretic effects of subcutaneous (SC) administration of furosemide to conventional methods of administration including intravenous (IV), per os (PO), and constant rate infusion (CRI) in healthy dogs.

Design

Prospective, randomized, cross‐over study.

Setting

Veterinary university research facility.

Animals

Seven healthy, adult mongrel dogs (3 males, 4 females).

Intervention

Each dog in the study was randomly assigned to receive a 2 mg/kg dose of furosemide via a single SC, IV, or PO dose at the beginning (time 0) of an 8‐hour study, or via CRI during an 8‐hour study period. Urine was collected by emptying the bladder using an indwelling catheter and blood samples were obtained via venipuncture at time 0 for baseline measurements and at 1, 2, 4, 6, and 8 hours into the study. Hourly urine output was calculated in all dogs for each study. Complete blood count, plasma total protein, blood urea nitrogen, creatinine, and renin concentration were measured for each sample.

Measurements and Main Results

The SC administration of furosemide resulted in a urine output per hour (UOP/h) that peaked at 1 hour with UOP/h returning to baseline at 4 hours after injection. Following IV administration, UOP/h also peaked at 1 hour but returned more rapidly to baseline levels at 2 hours after injection. With PO administration, UOP/h reached a maximum UOP/h at 2 hours but time to return to baseline levels was prolonged to 6 hours after administration. With CRI administration, the time to the maximum UOP/h was delayed to 4 hours after injection but UOP/h was then maintained throughout the study period.

Conclusions

Total urine output following SC administration of furosemide in healthy dogs was similar when compared to the IV and PO route. Subcutaneous route may be an effective means for administration of furosemide in dogs, particularly when IV access is difficult.
Recursive Least Squares Identification Algorithms for Multiple-Input Nonlinear Box–Jenkins Systems Using the Maximum Likelihood Principle
Authors: Chen Feiyan , Ding Feng
Published: April 2015

Multiple-input multiple-output systems can be decomposed into several multiple-input single-output systems. This paper studies identification problems of multiple-input single-output nonlinear Box–Jenkins systems. In order to improve the computational efficiency, we decompose a multiple-input nonlinear Box–Jenkins system into two subsystems, one containing the parameters of the linear block, the other containing the parameters of the nonlinear block. A decomposition based maximum likelihood generalized extended least squares algorithm is derived for identifying the parameters of the system by using the maximum likelihood principle. Furthermore, a decomposition based generalized extended least squares algorithm is presented for comparison. The numerical example indicates that the proposed algorithms can effectively estimate the parameters of the nonlinear systems and can generate more accurate parameter estimates compared with existing methods.
The Energy Release to Static Gas From a 12-Joule High Energy Ignition System
Authors: Odgers J. , Coban A.
Published: April 2015

Details are given of a calorimetric-bomb technique used to determine the energy released to the gas, from a spark derived from a high-energy source (∼12J). The statistical nature of the energy release is commented upon, and the number of repeat tests required to obtain a valid mean is discussed. Scattered data from other sources are cited, together with their relevance to the present tests. Measurements of energy are given for the single plug which was subjected to exhaustive testing over a range of pressures from 1.0 kPa to 2500 kPa, and which was repeated for various gases, namely — air, oxygen, nitrogen, carbon dioxide, helium and argon. The results of these tests may be correlated in terms of the pressure and the ionization potential of the gas.
Through Flow Analysis of Centrifugal Compressors
Authors: Goulas A. , Baker R. C.
Published: April 2015

The matrix through-flow analysis is applied to the S1 and S2 surfaces of a centrifugal compressor impeller. The dissipation force is expressed in terms of the stress tensor and this allows the κ-ε model of turbulence to be applied. The limitations on the use of this model are discussed. Solutions are presented for both S1 and S2 surfaces. For the S2 surface, the streamline pattern for the κ-ε model is compared with the isentropic solution. Values of meridional velocity are also plotted. For the S1 surface, as well as the κ-ε model, a simple turbulence model using the logarithmic law of the wall is used. The simple model confirms that large entropy gradients are responsible for the wake formation and the κ-ε model predicts the wake formation.
Design of a High Efficiency Combined Cycle Electric Power Plant for Low Btu Coal-Gas
Authors: Mogul J. M. , Cole R. W. , Manning G. B.
Published: April 2015

A key to achieving efficient, environmentally acceptable electric power from combustion of low Btu coal gas is through an advanced design, combined gas turbine-steam turbine cycle system, integrated with a low Btu gasifier. A conceptual design of a commercial size plant of this concept is presented. It consists of a modularized system built around commercially available, pressurized fixed-bed gasifiers, hot-fuel gas cleanup and desulfurization, an advanced 3000 F (1649 C) heavy-duty gas turbine, and a conventional steam system. The turbine subsystem, with extensive test background on petroleum fuels, utilizes transpiration-air-cooling to maintain moderate metal temperatures and to protect the components from the aggressive environment. Emphasis in the design of the power plant is placed on earliest possible commercialization.
Nonsteady Operational Behavior of Single-Shaft and Two-Shaft Closed-Cycle Gas Turbines
Authors: Bammert K. , Krapp R. , Reiter U.
Published: April 2015

The nonsteady operational behavior of single- and two-shaft closed-cycle gas turbines is investigated on the basis of two reference plants. The behavior in case of a full-load release and after emergency shutdown was calculated. It is proved that these disturbances of operation can be mastered in two-shaft plants as well as in single-shaft plants. Furthermore, the stresses caused by dynamic changes in the circuit and to be considered in designing a closed-cycle gas turbine were investigated.
Optimization Analysis of a CCGT Nuclear Power Plant With Application to the HHT 3000 MWth Commercial Plant (HHT-Project)
Authors: Zollinger E. , Gregory N.
Published: April 2015

In connection with the HHT-Project, the Swiss Federal Institute for Reactor Research (EIR) has performed an optimization analysis of the HHT-3000 MWth commercial plant with a closed-cycle helium turbine one-loop concept. This paper gives first a description of the analyzed plant with general considerations of optimization techniques followed by the presentation of results of optimization and sensitivity calculations.
Design Considerations for Future Heat Recovery Boilers Aboard Naval Vessels
Authors: Katz Yoram
Published: April 2015

The DD963 Spruance Class Destroyers were the first Naval vessels to be outfitted with auxiliary type heat recovery boilers. After a combined total operating time of approximately 30,000 hr, various conclusions relative to future design considerations can be observed. The objective of this paper is threefold: (a) to identify existing problem areas that need further imporvement, (b) to develop new design criteria for future heat recovery boilers, and (c) to consolidate the above findings into an optimum design.
Gas Turbine Education and Research Programs in German Universities
Authors: Bammert K. , Sandstede H.
Published: April 2015

The education scheme at German Universities for Mechanical Engineers, especially for engineers for turbomachinery, is discussed. The duration of the studies is at least eight terms, divided in two parts. The first part is concluded with the Vorexamen [first major examinations] and the second is granted with the title “Diplom-Ingenieur.” Post graduate studies are possible in the institutes and often lead to a doctor’s degree. Another independent way to become engineer is at “Fachhochschulen” [technical academy]. The final degree is “graduierter Ingenieur” [ing. grad] after six terms of study. Research programs are sponsored by the government, industry or research societies. Gas turbine research is demonstrated by means of the facilities at the Technical University Hannover, Germany, as an example.
Rationalization of Empirical Loss Coefficients and Their Application in One Dimensional Performance Prediction Procedures for Centrifugal Compressors
Authors: Whitfield A.
Published: April 2015

The flow through centrifugal compressors is often highly separated and fully three-dimensional. Modern computing techniques have not yet provided the ability to predict this three-dimensional separated flow. The design engineer has the need of a relatively simple performance prediction procedure in order to assess the potential of any proposed design. Consequently, a number of performance prediction procedures, with the general assumption of one-dimensional adiabatic flow, have been published. A common and essential feature of all these procedures is the use of empirical parameters in order to expand the one-dimensional flow into a description of the fully three-dimensional flow. These empirical parameters usually describe the loss mechanism and the flow deviation in any duct. Presented in footnote is a one-dimensional procedure which separated the fundamental gas dynamics from the empiricism used. Consequently, it is a relatively simple matter to apply alternative empirical parameters, and, more importantly, it is also possible for the design engineer to readily apply empirical relationships built up from his own experience. Unfortunately, numerous techniques are used to define the losses, and it may be necessary for the design engineer to redefine his own data in terms compatible with the computer program available to him.
Aerodynamic Force and Moment on Oscillating Airfoils in Cascade
Authors: Atassi H. , Akai T. J.
Published: April 2015

A systematic theory is developed for airfoils in cascade oscillating about their mean position with constant interblade phase angle in a uniform incompressible flow. The theory fully accounts for the effect of angle of attack of the mean flow, the airfoils’ thickness and camber, and the cascade solidity and stagger. The formulation leads to two singular integral equations in the complex plane which are solved numerically by collocation. The results show that for certain values of the interblade phase angle, the airfoils’ thickness and incidence have a significant influence on the unsteady lift and moment particularly for staggered cascades.
Propulsion Test Facilities Technical Capabilities and International Use
Authors: Kamchi J. S. , Compitello F. E.
Published: April 2015

This paper briefly reviews the technical capabilities of the NAFP and several facilities that will support future aerospace RDT&E. It explores the subject of increasing test facility utilization and their international use.
Advanced Turbofan Engines for Low Fuel Consumption
Authors: Sens William
Published: April 2015

The anticipated commercial aircraft fuel usage through the year 2000 is divided into three categories: that which will be consumed by existing engines, new production of current type engines, and new turbofan engines with advanced technology. Means of improving fuel consumption of each of these engine categories will be reviewed and the potential fuel savings identified. The cycle selection and design characteristics of an advanced turbofan engine configuration will be discussed and the potential improvements in fuel consumption and economics identified.
Cooling Characteristics of Film Cooled Turbine Vane Having Multi-Row of Ejection Holes
Authors: Sakata K. , Usui H. , Takahara K.
Published: April 2015

Film-cooled turbine vanes having 14 rows of round holes were designed. Two-dimensional cascade tests of two kinds of scaled vanes were carried out and cooling performances were obtained. Coolant flow distributions were controlled by the impingement and plenum chamber configuration. Higher cooling effectiveness than 0.65 was obtained for the coolant flow ratio of 4.5 percent. And it was clarified that the distributions of cooling effectiveness of the vane surface was governed by the configuration of coolant flow distribution to the cooling hole rows, and, that with using relatively greater amount of coolant to the leading edge region, higher cooling performance can be obtained. Also, numerical calculations of cooling performance and prediction for turbine application were presented.
A Digital Approach to Industrial Gas Turbine Control
Authors: Tipton J.
Published: April 2015

The paper discusses the very varied system requirements for industrial gas turbines, not only in the areas of sequencing and fuel control, but also for engine condition monitoring and automatic fault diagnosis. A digital electronic system developed by Lucas Aerospace using the latest micro-computer technology is then described. The major design constraint on the system was flexibility, to enable it to satisfy the complete range of requirements. This extends what was originally a fuel control system into an engine management system.
Vaneless Diffuser Flow With Extremely Distorted Inlet Profile
Authors: Bammert K. , Rautenberg M. , Wittekindt W.
Published: April 2015

The exit flow distribution of 90-deg centrifugal compressor impellers is distorted in peripheral direction as well as over the diffuser depth. First, there are the rotating jet-and-wake regions behind each impeller channel. Second, the flow has a completely distorted inlet profile from the front to the back wall of the diffuser. Measurements of static and total pressure, total temperature, and flow angle profiles along the whole diffuser length have been carried out in a high specific speed compressor. The results show great angle and total pressure differences in the first part of the diffuser and a backflow zone near the front wall. At the end of the diffuser, a separation zone was located. It is shown that by means of a one-dimensional calculation method, using a dissipation factor, the measured representative mean values of the diffuser flow can be determined very well in the regions where no separation occurs.
Aerodynamic Development of Stages for Industrial Centrifugal Compressors: Part 2 — Test Data Analysis, Correlation and Use
Authors: Benvenuti E.
Published: April 2015

The considerable amount of experimental data collected on specifically designed single-stage test rigs are correlated so as to allow a straightforward use for the design and performance prediction of stage configurations needed for industrial compressor manufacture. Internal stage flow-field measurements are further analyzed by means of proper methods to achieve information valid for improving existing stage, fluid-dynamic models. Suitable use of the stage performance data allows the laying out of standard stage series of given geometries capable of satisfying a wide range of requirements without continuously resorting to specific, restricted application designs.
Experimental Study of an Axial Compressor Rotor Transfer Function With Non-Uniform Inlet Flow
Authors: Colpin J. , Kool P.
Published: April 2015

The aim of the investigation is to study the propagation of a non-uniform upstream flow field through a rotating blade row. The flow is investigated using classical pneumatic instrumentation and hot wire anemometry. The latter allows one to determine the average flow values as well as the instantaneous blade-to-blade flow field. These measurements were performed upstream and downstream of a low-speed axial compressor stage rotor. A triangular inlet total pressure distortion was generated with a grid system, movable in the circumferential direction. The hot-wire data were processed with a periodic sampling and averaging technique to obtain the three-dimensional blade-to-blade flow downstream of the rotor at mid-span. The modification of the blade wakes and the existence of large absolute flow angle fluctuations are evidenced for different relative positions of the distortion and stationary hot wire.
Development of a Water-Cooled Gas Turbine
Authors: Horner M. W. , Day W. H. , Smith D. P. , Cohn A.
Published: April 2015

Development of water-cooled gas turbine technology was begun at General Electric in the early 1960’s, and by the early 1970’s, a small-scale turbine had been operated to temperatures of 2850 F and 16 atm, with metal temperature less than 1000 F. The Water-Cooled Turbine Development Program was begun in 1974, funded by the Electric Power Research Institute, to do preliminary design on a utility-size gas turbine using water cooling and to do basic technology development to address the problem areas. This paper presents the results of the program, including descriptions of the test hardware and data on phenomena, such as corrosion, erosion, heat transfer, and water collection. Cycle analysis results are presented for two potential combined cycle configurations: (a) one using low-Btu coal gas fuel, and (b) one using a heavy liquid fuel. Summary performance curves are given showing the effect of changes of pressure ratio and firing temperature. Methods of improving the baseline cycle and their effect on baseline performance which are judged most promising are also given on the performance curves. Turbine design features to achieve low component metal surface temperatures for increased fuels flexibility are given with particular emphasis to the first-stage nozzles and buckets. Fundamental development testing needs have been identified and programs have been put into place to bring the water-cooled turbine to a point where a full-size water-cooled turbine can be built. Descriptions of the development test facilities, task descriptions, test plans and /or test results are given for eight tasks.
A High-Effectiveness Regenerator Design Concept
Authors: O’Reilly W. J.
Published: April 2015

Continuing worldwide escalation of fuel prices has provided the impetus for the design and manufacture of power conversion equipment of higher efficiency. A high-effectiveness regenerator design, based on adaptions of the criteria used in the aerospace heat exchanger industry, is presented in this paper. The reasoning leading to the design of a stainless steel plate-and-fin regenerator is developed. Material, fabrication, and laboratory test information for a regenerator for a 15,000-hp (11.18 × 106 w) heavy-duty gas turbine is also presented.
Propeller Unsteady Thrust due to Operation in Turbulent Inflows
Authors: Thompson D. E.
Published: April 2015

In order to better understand the broadband radiated sound and vibrations due to a propulsor blade row operating in a turbulent inflow, an experimental and analytical investigation of the unsteady thrust response of a series of propellers due to operation in turbulent inflows having various characteristic parameters was conducted. The propeller variable considered was blade spacing. The turbulence variables considered were characteristic length scale and intensity. Homogeneous, isotropic turbulence was considered. The propeller unsteady thrust spectra were measured for each propeller over a range of turbulent inflow conditions. Comparisions of experimental spectra with those due to two different analytical methods are made. Conclusions are drawn regarding the accuracy of the two analytical methods.
Environmental Assessment of Gas Turbine/Steam Turbine Combined Cycles
Authors: Kalfadelis C. D. , Shaw H. , Folsom B. A. , Corley T. L.
Published: April 2015

The environmental aspects of the conceptual base-load, combined gas-steam turbine power plants designed by General Electric and Westinghouse in Phase II of the Energy Conversion Alternatives Study (ECAS) were analyzed. Each contractor had developed a combined cycle design which incorporated an integrated coal gasifier producing low-heat-content fuel gas, as well as a design fueled by coal-derived liquid purchased from an off-site producer. The conceptual power plants each produced some 60 to 900 MWe (gross), employing gas turbine inlet temperatures of 1600–1900 K. Equilibrium combustion gas properties were calculated for each system, and kinetic calculations were made for NOx production. The systems burning gaseous fuel were estimated to meet NOx emission standards. Neither design which used liquid fuel was estimated to meet NOx standards because of the high nitrogen content of the coal-derived synthetic liquid fuel.
Hydrostatic Power Splitting Transmissions Design and Application Examples
Authors: Pichard J. , Besson B.
Published: April 2015

After recalling the inventive methods used in the design analysis procedure of hydrostatic power splitting transmissions, theoretical and experimental application examples are presented. More particulars are detailed: a) determining elements and tests results of a 230-kw experimental transmission that can be applied to road and off-road propulsion, b) design analysis procedure and prediction of a large ratio coverage transmission appropriate to light vehicles such as automotive cars. Conclusions are drawn as regards the future prospects of these transmissions.
The Optimization of Engine Transmission Matching Reduces Car Fuel Consumption
Authors: Castelli P. , Morello L.
Published: April 2015

The advantages offered by a continuously variable transmission are briefly indicated The rubber-belt, electronically controlled, automatic transmission designed and built by Fiat in the frame of a Research program financed by the Italian National Research Council is described. The performance and fuel consumption results of the prototype equipped with this transmission are compared with the corresponding results of the conventional car.
Rotordynamic Instability in Centrifugal Compressors: Are All the Excitations Understood?
Authors: Vance J. M. , Laudadio F. J.
Published: April 2015

A published history of rotordynamic instability problems with centrifugal compressors is documented from the literature. Established theory for computerized stability anaylysis is reviewed, and the use of cross-coupled stiffness and damping coefficients to represent destabilizing forces is explained. A derivation of cross-coupled stiffness coefficients for torquewhirl is presented. Experimental measurements made on a simple test rig with a radial-vaned impeller are described, which show that a working fluid can exert destabilizing forces on such an impeller. These forces must be considered, in addition to journal bearing and internal hysteresis excitations, if accurate predictions of rotordynamic instability thresholds are to be made. Several classifications of these forces are hypothesized.
U.S. Navy, LM2500 Gas Turbine Condition Monitoring Development Experience
Authors: Kandl M. G. , Groghan D. A.
Published: April 2015

A review of U.S. Navy experience in the development of a shipboard gas turbine condition monitoring system (CMS) is presented. The system considered was developed for use with the 20,000 HP General Electric, LM2500 main propulsion gas turbine engines used on the Navy’s DD-963 class destroyers and FFG-7 patrol frigate class ships. The initial CMS development program started with a broad range of measured gas turbine parameters and was successively reduced to a simpler system using only selected parameters useful for the marine application. A land-based test as well as an at-sea test is presented, together with a discussion of the impact such a system would have on DD 963 class engine removals.
Blade Excitation by Elliptical Whirling in Viscous-Damped Jet Engines
Authors: Klompas Nicholas
Published: April 2015

An extension of the author’s earlier method of analyzing multi-shaft jet engine dynamics accounting for flexibility of bladed disks is outlined to calculate the first whirl harmonic for given nonlinear characteristics of squeeze-film dampers. A second whirl harmonic, of which experimental verification is found in Campbell’s paper of 1924, is shown induced by orbit ellipticity. The possibility that this harmonic, especially due to backward whirling, may be a source of blade excitation at higher frequencies than currently recognized from linear analysis is discussed by relating some engine experience.
High Temperature Combustor Designed for Operation With Coal Derived Low Btu Gaseous Fuels
Authors: Koblish T. R. , Nucci L. M.
Published: April 2015

Studies sponsored by the U. S. Department of Energy (DOE) have indicated that the combined cycle, incorporating an open cycle gas turbine having a Low Btu gas (LBG) fueled combustor operating at temperatures over 2600 F and a closed cycle steam turbine can produce cost competitive electric power from gasified coal. For increased efficiency, the coal gasification system would be integrated with the gas turbine which supplies the compressed air for the coal gasification system, and the steam turbine which supplies the steam for the gasification system. The coal gasifier would provide a pressurized low heating value (LBG) fuel (at the order of ISO Btu/SCF (5590 kJ/m3) for combustion in the gas turbine engine. Under DOE sponsorship, one of the gas turbine engine components being investigated both analytically and experimentally, is the LBG fueled combustor. This paper describes the LBG configuration background technology utilized in the design of the combustor and the test program outline for substantiation of the design approach.
Calculation of Four-Quadrant Characteristics of Turbines
Authors: Zehner P.
Published: April 2015

For handling of extreme operation conditions of turbines or in cases of disturbance or breakdown of turbine plants, it is important to have knowledge about the characteristics far away from the design point. This paper explains the attempt of a calculation method for computing the complete four-quadrant characteristics of a turbine on the basis of the mean section cascade characteristics of the blading. The cascade characteristics for normal and backward flow are pointed out and with these are calculated the stage characteristic lines for perfect gas. The turbine characteristics are computed by superimposition of the stage characteristics and compared to measuring results.
The Prospects for Solar-Powered Closed-Cycle Gas Turbines
Authors: Kuo S. C. , Horton T. L. O. , Shu H. T.
Published: April 2015

This paper presents the results of a systems study to evaluate the technological and economic feasibility of utilizing closed-cycle gas turbines integrated with an advanced-design central receiver for solar power generation. Applicable turbomachinery technologies were reviewed to estimate their future advances expected. System design-point performance, component size, and cost characteristics of closed-cycle air turbines were estimated, and system operational and control characteristics, including off-design and part-load performance characteristics, are discussed. Critical system components were reviewed to estimate the appropriate testing and development time and cost schedules required.
Jet Engine Computer Aided Tube Design System
Authors: Jones D. C. , Head C. D. , Crupi John
Published: April 2015

At Pratt & Whitney Aircraft a system to design tubing, produce final engineering drawings and establish data for manufacturing was developed that effectively integrates man and computer. A “wire tube” defined on a wooden mockup is fed to a host computer to perform stress and vibration analysis and check clearance to other tubes and components. The tube is then retrieved from a data base, maintained on the host, by the Computervision system to produce final drawings. The data base is then available to manufacturing to drive an automatic tube bender.
Blade Trailing Edge Heat Transfer
Authors: Brown A. , Mandjikas B. , Mudyiwa J. M.
Published: April 2015

In this article measurements of heat transfer, pressure loss, and friction factor inside simulated trailing edges of turbine blades are presented. The trailing edges considered are vented and the internal heat transfer surfaces are extended by means of staggered arrays of pillars interconnecting the blade pressure and suction surfaces. A number of pillar arrays and trailing edge configurations are considered, namely pillar pitch to diameter ratios nominally of 2, 3, and 4 and trailing edge included angles of 0, 10, 15, and 20 deg. The range of Reynolds numbers covered based on pillar diameter and maximum velocity through a row of pillars is from 104 to 2 × 105.
Comparative Testing of Petroleum Surrogate Fuels With Coal-Derived Liquids in a Combustion Turbine Burner
Authors: Singh P. P. , Bazarian E. R. , Mulik P. R. , Bauserman G. W. , Cohn A. , Stein T. R.
Published: April 2015

Tests have been made in a combustion turbine burner using six petroleum-derived surrogate (PDS) fuels simulating six coal-derived liquid (DCL) fuels tested earlier. The purpose being to examine their suitability for use in place of scarce CDL fuels for combustor development. The PDS and DCL fuels were matched in terms of aromaticity and fuel bound nitrogen although differences in viscosity, distillation range and constituent species existed. In three cases, the low fuel bound nitrogen present in the PDS fuels was made equal to their coal liquid counterparts via the addition of quinoline. All six PDS fuels were evaluated on a 0.14-m-dia combustor while one of the surrogate fuels was evaluated on a 0.3-m-dia Westinghouse commercial combustor.
The Development and Application of Improved Combustor Wall Cooling Techniques
Authors: Wassell A. B. , Bhangu J. K.
Published: April 2015

The continuing emphasis over the past few years on the development of lower sfc, long on-wing life and low emission engines for commercial transportation has put a premium on combustor liner cooling techniques employing less cooling flow. Rolls-Royce pioneered the fully machined ring and impingement cooling concepts which formed the basis for the RB211 combustor design. Further improvement of the impingement cooling technique has led to the development of a laminated, psuedo-transpiration material. It exploits the high impingement heat transfer coefficients and provides an extended internal surface area for heat transfer. Rolls-Royce has developed this material primarily for combustor applications. A major milestone has now been achieved with the certification by the CAA of a Spey combustor variant incorporating this material for limited release for commercial operations. These combustors are now entering service in the BAe1-11 with a number of UK airlines.
Combustion Effects of Coal Liquid and Other Synthetic Fuels in Gas Turbine Combustors: Part I — Fuels Used and Subscale Combustion Results
Authors: Singh P. P. , Cohn A. , Pillsbury P. W. , Bauserman G. W. , Mulik P. R. , Bazarian E. R. , Stein T. R.
Published: April 2015

Combustion tests on over twelve types of coal derived liquid fuels from the EDS, H-coal, SRC-I and SRC-II processes and three shale oil fuels have been conducted in gas turbine type combustors. Emission measurements were made of Nox, smoke, CO, and unburned hydrocarbons. Combustor wall temperature profiles were measured. The results are correlated with the fuel properties-percent nitrogen, hydrogen and aromaticity. This part of the paper discusses the fuels used in subscale combustion tests along with the test results. A companion paper (Part II) describes the results of full-scale combustor tests and a long term corrosion/deposition test.
Fuel Character Effects on J79 and F101 Engine Combustor Emissions
Authors: Gleason C. C. , Martone J. A.
Published: April 2015

Results of a program to determine the effects of fuel properties on the pollutant emissions of two US Air Force aircraft gas turbine engines are presented. Thirteen test fuels, including baseline JP-4 and JP-8, were evaluated in a cannular (J79) and a full annular (F101) combustor. The principal fuel variables were hydrogen content, aromatic structure, volatility, and distillation end point. Data analysis shows that fuel hydrogen content is a key fuel property, particularly with respect to high power emissions (oxides of nitrogen and smoke), and that low power emissions (carbon monoxide and hydrocarbons) are more dependent on fuel atomization and evaporation characteristics.
Probe Effects in Gas Turbine Combustor Emission Measurements
Authors: Clark J. A. , Mellor A. M.
Published: April 2015

Four geometrically distinct, stainless steel probes are used to study the concentrations of CO, HC, NO, and NOx at several different radial and two different axial positions within a simplified gas turbine combustor. The probes are all water cooled but do not employ an aerodynamic quench. They are designed to assess the effect of tip shape, tip to body proximity (for right angle configurations), and probe entry point into the flowfield on measured pollutant concentrations. Though probe entry point and tip to body proximity are shown to imperceptibly affect the pollutant concentrations, probe tip geometry has a marked impact on the measured pollutant levels. Specifically, the tapered-tip probe yields depressed CO and HC, and elevated NO concentrations compared to the other three blunt-tipped probes. Regarding reproducibility, the pollutant concentrations measured with one of the blunt-tipped probes in this study are compared to pollutant levels measured with the same probe three years ago (Tuttle et al., 1976).
Some Aspects on Increasing Gas Turbine Combustor Exit Temperature
Authors: Sjöblom B. G. A.
Published: April 2015

A high turbine inlet temperature promotes the gas turbine overall cycle efficiency. Problems arising in the combustion system when increasing the temperature are discussed. A high exit temperature aircraft gas turbine combustor was designed by deleting the dilution air in a double recirculation zone combustor. Rig test were carried out and comparisions were made with a reference combustor of conventional design. It was found that the overall fuel-air ratio could be increased from 0.0182 to 0.0315 without imparing the emission characteristics or the combustion efficiency at any power setting. The exit temperature pattern factor was improved by providing a proper fuel and air mixing.
Improvement of Paramater Estimation Through Uncertainty Analysis
Authors: Adams G. R.
Published: April 2015

Whenever multiple independent estimates of a complex performance parameter are available, the question of which estimate to use or how to best combine the data invariably arises. This paper describes a methodology which utilizes the uncertainty intervals for each of the independent estimates to improve the overall estimate of the parameter and to minimize the uncertainty of the final answer. In addition, a simple validity test is described which can help identify instrumentation or other associated errors. Sensitivity analyses are included to show the effect of incorrect uncertainty (or error) analyses of the independent estimators. Monte Carlo results are presented in support of the capability of this methodology.
A New Approach for Erosion Prediction due to Fly Ash
Authors: Kotwal R. , Tabakoff W.
Published: April 2015

With increasing interest in the burning of coal in industrial gas turbines, there is also concern for the precise determination of the erosive effects on the turbine components. Series of experiments were conducted to determine the effects of fly ash constituents, particle size, particle velocity, angle of attack and target temperature on the erosion of iron and nickel base alloys. Based on the experimental results, a semi-empirical equation has been obtained for the prediction of the erosion losses. This equation provides a new technique for predicting the metal erosion due to the fly ash produced by the conventional burning of coal.
Design, fabrication, and optical characteristics of freestanding GaN waveguides on silicon substrate
Authors: Sekiya Takuji , Sasaki Takashi , Hane Kazuhiro
Published: April 2015

Freestanding GaN waveguides were fabricated on a silicon substrate by a combination of Cl2 plasma reactive ion etching and XeF2 gas selective etching. The freestanding GaN waveguides ranged from 0.23 to 8 μm in width and were supported in air by bridge structures. The bridge structures were designed via rigorous electromagnetic simulations using the finite-difference time-domain method. The GaN layer was grown epitaxially on a silicon (111) substrate using a buffer layer to compensate for the crystal lattice constant mismatch. Using two types of masks, the GaN layer was etched using a Cl2 inductively coupled plasma. The 625-nm-thick GaN layer was etched by the Cl2 plasma at a substrate temperature of −17 °C to form the GaN waveguide patterns, at the expense of a 92-nm-thick HfO2 mask layer. The etching rate of the GaN layer was 170 nm/min and the etching ratio between the GaN and HfO2 layers was 6.8:1. The silicon substrate was then isotropically etched using XeF2 gas to generate air gaps underneath the GaN waveguides. The transmittance of the fabricated freestanding GaN waveguides was measured using a visible (406 nm) laser and an infrared (1550 nm) laser. The waveguide losses for a 730-nm-wide and 625-nm-thick waveguide were 2.6 dB/mm at 406 nm and 2.2 dB/mm at 1550 nm. These results indicate that the structures are likely to be useful for several visible waveguide devices combined with blue GaN light emitting diodes and for optical telecommunication waveguide devices using the wide transmission window of the GaN crystal.
Electronic properties of atomic-layer-deposited high-k dielectrics on GaSb(001) with hydrogen plasma pretreatment
Authors: Ruppalt Laura B. , Cleveland Erin R. , Champlain James G. , Bennett Brian R. , Boos J. Brad , Prokes Sharka M.
Published: April 2015

In this report, the authors investigate the use of H2/Ar-plasma exposure as a means for achieving high-quality electrical interfaces between p-type GaSb and atomic-layer-deposited Al2O3 dielectric films. Dry in-situ plasma treatments are shown to reduce the estimated density of interface states by over two orders of magnitude compared to a standard wet HCl-treatment, without increasing gate leakage. The chemical compositions of the natively oxidized and treated GaSb surfaces are analyzed via x-ray photoemission spectroscopy (XPS). XPS spectra indicate that the native GaSb oxide is segregated, with Sb-oxide compounds localized at the air interface. Effective H2/Ar-plasma treatments act to remove the Sb-oxide, resulting in a surface Ga-oxide layer enriched in Ga2O3.
RETRACTED: The protein LEM promotes CD8
+
T cell immunity through effects on mitochondrial respiration
Authors: Okoye Isobel , Wang Lihui , Pallmer Katharina , Richter Kirsten , Ichimura Takahuru , Haas Robert , Crouse Josh , Choi Onjee , Heathcote Dean , Lovo Elena , Mauro Claudio , Abdi Reza , Oxenius Annette , Rutschmann Sophie , Ashton-Rickardt Philip G.
Published: April 2015

LEM gets T cells the energy they need

During an infection, T cells proliferate extensively to build a sufficient army to defeat the invading pathogen. Carefully regulated changes in metabolism let T cells do this, but the specific nature of these changes is not fully understood. Using forward genetics in mice to screen for genes that regulate T cell immunity, Okoye
et al.
identified a mutation in the gene that encodes a protein they named lymphocyte expansion molecule (LEM) (see the Perspective by O'Sullivan and Pearce). LEM enhanced T cell immunity, including both proliferation and memory cell generation, in response to chronic viral infection. LEM facilitated these changes through effects on mitochondrial respiration.

Science
, this issue p.
995
; see also p.
976
Casein kinase 2 (CK2) phosphorylates the deubiquitylase OTUB1 at Ser
16
to trigger its nuclear localization
Authors: Herhaus Lina , Perez-Oliva Ana B. , Cozza Giorgio , Gourlay Robert , Weidlich Simone , Campbell David G. , Pinna Lorenzo A. , Sapkota Gopal P.
Published: April 2015

The kinase CK2 promotes the nuclear function of the deubiquitylase OTUB1 in DNA damage repair.
The mTORC1/4E-BP pathway coordinates hemoglobin production with
L
-leucine availability
Authors: Chung Jacky , Bauer Daniel E. , Ghamari Alireza , Nizzi Christopher P. , Deck Kathryn M. , Kingsley Paul D. , Yien Yvette Y. , Huston Nicholas C. , Chen Caiyong , Schultz Iman J. , Dalton Arthur J. , Wittig Johannes G. , Palis James , Orkin Stuart H. , Lodish Harvey F. , Eisenstein Richard S. , Cantor Alan B. , Paw Barry H.
Published: April 2015

Inadequate leucine uptake by maturing red blood cells limits the production of hemoglobin.
Implications of Efficient Hepatic Delivery by Tenofovir Alafenamide (GS-7340) for Hepatitis B Virus Therapy
Authors: Murakami Eisuke , Wang Ting , Park Yeojin , Hao Jia , Lepist Eve-Irene , Babusis Darius , Ray Adrian S.
Published: April 2015

Tenofovir alafenamide (TAF) is a prodrug of tenofovir (TFV) currently in clinical evaluation for treatment for HIV and hepatitis B virus (HBV) infections. Since the target tissue for HBV is the liver, the hepatic delivery and metabolism of TAF in primary human hepatocytes
in vitro
and in dogs
in vivo
were evaluated here. Incubation of primary human hepatocytes with TAF resulted in high levels of the pharmacologically active metabolite tenofovir diphosphate (TFV-DP), which persisted in the cell with a half-life of >24 h. In addition to passive permeability, studies of transfected cell lines suggest that the hepatic uptake of TAF is also facilitated by the organic anion-transporting polypeptides 1B1 and 1B3 (OATP1B1 and OATP1B3, respectively). In order to inhibit HBV reverse transcriptase, TAF must be converted to the pharmacologically active form, TFV-DP. While cathepsin A is known to be the major enzyme hydrolyzing TAF in cells targeted by HIV, including lymphocytes and macrophages, TAF was primarily hydrolyzed by carboxylesterase 1 (CES1) in primary human hepatocytes, with cathepsin A making a small contribution. Following oral administration of TAF to dogs for 7 days, TAF was rapidly absorbed. The appearance of the major metabolite TFV in plasma was accompanied by a rapid decline in circulating TAF. Consistent with the
in vitro
data, high and persistent levels of TFV-DP were observed in dog livers. Notably, higher liver TFV-DP levels were observed after administration of TAF than those given TDF. These results support the clinical testing of once-daily low-dose TAF for the treatment of HBV infection.