bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tanker Fleet Upgrade: Gas Turbine and Propulsion Control Systems Retrofit
Authors: Kemp Stephen , Cozzetta Marc , Harclerode Scott 
Published: February 2015

Many gas turbines commissioned in the late 1960’s and early 1970’s employ “first generation” electronic control systems. Usually a combination of analog-digital fuel and temperature control circuits and electromechanical relay sequencers, these systems (and the gas turbines they were designed to control) inevitably experience diminished performance as they age.
This paper describes the project to design, construct, install, and commission replacements for the control systems on the main and auxiliary gas turbines and the propulsion controls for Chevron Shipping Company’s domestic tanker fleet. Since replacing the main gas turbine control system and propulsion controls on the oil tanker Chevron Colorado in the spring of 1993, both the main and auxiliary turbine and propulsion controls have been replaced on each of the other four (4) tankers.
Triple modular redundant (TMR) digital systems were selected 10 replace the original analog-digital control systems on the main and auxiliary gas turbines (MGT & AGT). Required American Bureau of Shipping and US Coast Guard certification tests, as well as dock and sea trials for the new control systems are discussed. Economic results including maintenance repair action rates, start percentages, availabilities, and fuel savings are detailed.
U.S. Navy MK 105 Minesweeping System Upgrade Program: Installation of Pratt & Whitney Canada ST6L-813 Turbine
Authors: Levine Sheldon , Jarvis David G. , Lehman J. Michael 
Published: February 2015

The U.S. Navy has in its arsenal a helicopter-towed magnetic minesweeping system for the task of sweeping seas of underwater magnetic influence mines. The EDO MK 105 Airborne Minesweeping System is a helicopter-towed, unmanned hydrofoil platform which operates at high speed in varied ocean environments with minimum risk to personnel and equipment. A gas turbine engine-generator set aboard the platform provides electrical power solely for the minesweeping operation.
Based on a need to improve its supportability, as well as reliability and maintainability, the U.S. Navy decided to update the present operational system. This decision necessitated the re-engining of the existing power plant Accordingly, the Pratt & Whitney Canada PT6 aircraft gas turbine engine was selected as the replacement prime mover. This paper discusses the gas turbine engine, the system design that was developed to integrate an aircraft turbine into this unusual Naval craft and the successful test program. The turbine was designated Model ST6L-813 for this marine application.
Development of an Oilless, Gearless, and Bleedable Under Armor Auxiliary Power Unit
Authors: Nims Robert 
Published: February 2015

The oilless, gearless and bleedable under armor auxiliary power unit (UAAPU) development program is providing the United States Army with a technically advanced auxiliary power unit (APU) for military tracked vehicles. Fully functional prototypes in two configurations are being demonstrated in both laboratory and field tests. The APU power output is 32 kw (43 shp) with 10 to 20 kw supplied as electrical power and the balance of power delivered as elevated pressure bleed air for use in conjunction with the vehicle nuclear, biological, and chemical (NBC) filtration and environmental control system (ECS).
The design of the UAAPU incorporates air bearings and a shaft-speed permanent-magnet starter/generator with electronic power conditioning to eliminate completely the need for oil lubrication and an auxiliary gearbox. This significantly simplifies the mechanical design of the APU with resulting reliability, durability, and maintainability improvements. Over 600 hours of laboratory system development test time has been logged and 90 hours in field tests on an M1A1 main battle tank. Operations in the field have included both gunnery and simulated warfare training exercises.
Current Status of 300 kW Industrial Gas Turbine R&D in Japan
Authors: Murayama Takumi , Nagata Kunihiro , Abe Hiroyuki , Ogiyama Hisao 
Published: February 2015

The Ceramic Gas Turbine (CGT) has great advantages in terms of energy efficiency, environmental protection, and fuel-diversification. In Japan, R&D on the 300 kW CGT has been carried out as one of the national projects entitled “New Sunshine Program”, which are promoted by the New Sunshine Project Promotion Headquarters, Agency of Industrial Science and Technology (AIST), Ministry of International Trade and Industry (MITI).
R&D on the CGT has progressed faithfully and now the operation of prototype CGTs (Turbine Inlet Temperature (TIT) of 1200 °C) is focused.
In the paper, the overall status of the R&D activities on the 300 kW CGT will be reviewed with the test results to-date, problems awaiting solution, and perspective for the prototype and pilot CGTs.
Progress on the AGATA Project: A European Ceramic Gas Turbine for Hybrid Vehicles
Authors: Lundberg Robert , Gabrielsson Rolf 
Published: February 2015

The European EUREKA project EU 209 or AGATA - Advanced Gas Turbine for Automobiles is a program dedicated to the development of three critical ceramic components; i. catalytic combustor, ii. radial turbine wheel, iii. static heat exchanger, designed for a 60 kW turbogenerator hybrid electric vehicle. The objective is to develop and test the three components as a full scale feasibility study with an industrial perspective. The AGATA partners represent car manufacturers as well as companies and research institutes in the turbine, catalyst and ceramic material fields in France and Sweden. The program has been running since early 1993 with good progress in all three sub-projects.
The turbine wheel design is now completed. FEM calculations indicate that the maximum stress occur during cold start and is below 300 MPa. Extensive mechanical testing of the Si3N4 materials from AC Cerama and C&C has been performed.
The catalytic combustor operates uncooled at 1350°C. This means a severe environment for both the active catalyst and the ceramic honeycomb substrates. Catalysts with high activity even after aging at 1350°C have been developed. Ceramic honeycomb substrates that survive this temperature have also been defined. The catalytic combustor final design is ready and the configurations which will be full scale tested have been selected.
The heat exchanger will be a ceramic recuperator with 90 % efficiency. Both a tube concept and a plate concept have been studied. The plate concept has been chosen for further work. Sub-scale plate recuperators made of either cordierite or SiC have been manufactured by C&C and tested.
Material Evaluation of Large Single Crystal and Directionally Solidified Bucket Castings for Advanced Land-Based Gas Turbines
Authors: Yamamoto H. , Yamamoto M. , Imai K. , Miyazaki M. , Satoh M. , Kobayashi Y. , Matsuzaki H. 
Published: February 2015

The development of large single crystal and directionally solidified hollow and solid bucket castings has been carried out for the high performance advanced land-based gas turbine of 1500°c class turbine inlet temperature, using CMSX-2 single crystal and CM247LC directionally solidified alloys*. The castability for large single crystal bucket casting has been established by optimizing the casting parameters and bucket shape in order to prevent the grain defects which tend to be formed more easily for larger casting size and are most harmful for high temperature strength of single crystal. These casting processes were successsfully applied to larger directionally solidified buckets with additional modified molding process.
The developed large single crystal hollow and solid bucket castings after solution and optimized aging treatment indicated excellent microstructure and high temperature mechanical properties such as stress rupture and low cycle fatigue strength. Also, long-term phase stability of both alloys at intermediate temperatures has been verified.
Fatigue Crack Growth Behavior of PWA 1484 Single Crystal Superalloy at Elevated Temperatures
Authors: Telesman Jack , Ghosn Louis J. 
Published: February 2015

A study was done to determine the fatigue crack growth behavior of a PWA 1484 single crystal nickel base superalloy in a temperature range of 427°C to 871°C. Two distinctive failure modes were observed which were a function of both temperature and frequency. At lower temperatures and higher frequencies crack growth occured on the {111} octahedral slip planes at an oblique angle to the loading direction. Higher temperatures and decrease in frequencies favored a Mode I type failure process. The failure mode transitions were explained by invoking arguments based on environmental damage mechanisms.
The fatigue crack growth rate data were analyzed using three different crack driving force parameters. The parameters investigated consisted of the Mode I stress intensity parameter corrected for the inclined crack trajectory, and two different octahedral Mode II parameters which are based on the calculation of resolved shear stresses on the {111} slip systems. The Mode I ΔK parameter did a fair job in correlating the data but did not collapse it into a single narrow band. The two octahedral crack driving force parameters, ΔKRSS and a newly proposed ΔKOCT, collapsed all the data into a single narrow band. In addition to correlating the fatigue crack growth rates, the two octahedral parameters also predicted the {111} planes on which the crack growth took place.
Boundary Layer Development in Axial Compressors and Turbines: Part 2 of 4 — Compressors
Authors: Halstead David E. , Wisler David C. , Okiishi Theodore H. , Walker Gregory J. , Hodson Howard P. , Shin Hyoun-Woo 
Published: February 2015

This is Part Two of a four-part paper. It begins with Section 6.0 and continues to describe the comprehensive experiments and computational analyses that have led to a detailed picture of boundary layer development on airfoil surfaces in multistage turbomachinery.
In this part, we present the experimental evidence used to construct the composite picture for compressors given in the discussion in Section 5.0 of Part 1. We show the data from the surface hot-film gauges and the boundary layer surveys, give a thorough interpretation for the baseline operating condition and then show how this picture changes with variations in Reynolds number, airfoil loading, frequency of occurrence of wakes and wake turbulence intensity. Detailed flow features are described using raw time traces. The use of rods to simulate airfoil wakes is also evaluated.
Interaction with Enzyme IIBMpo(EIIBMpo) and Phosphorylation by Phosphorylated EIIBMpoExert Antagonistic Effects on the Transcriptional Activator ManR of Listeria monocytogenes
Authors: Zébré Arthur Constant , Aké Francine Moussan , Ventroux Magali , Koffi-Nevry Rose , Noirot-Gros Marie-Françoise , Deutscher Josef , Milohanic Eliane 
Published: February 2015

ABSTRACTListeriae take up glucose and mannose predominantly through a mannose class phosphoenolpyruvate:carbohydrate phosphotransferase system (PTSMan), whose three components are encoded by themanLMNgenes. The expression of these genes is controlled by ManR, a LevR-type transcription activator containing two PTS regulation domains (PRDs) and two PTS-like domains (enzyme IIAMan[EIIAMan]- and EIIBGat-like). We demonstrate here that inListeria monocytogenes, ManR is activated via the phosphorylation of His585 in the EIIAMan-like domain by the general PTS components enzyme I and HPr. We also show that ManR is regulated by the PTSMpoand that EIIBMpoplays a dual role in ManR regulation. First, yeast two-hybrid experiments revealed that unphosphorylated EIIBMpointeracts with the two C-terminal domains of ManR (EIIBGat-like and PRD2) and that this interaction is required for ManR activity. Second, in the absence of glucose/mannose, phosphorylated EIIBMpo(P∼EIIBMpo) inhibits ManR activity by phosphorylating His871 in PRD2. The presence of glucose/mannose causes the dephosphorylation of P∼EIIBMpoand P∼PRD2 of ManR, which together lead to the induction of themanLMNoperon. Complementation of a ΔmanRmutant with variousmanRalleles confirmed the antagonistic effects of PTS-catalyzed phosphorylation at the two different histidine residues of ManR. Deletion ofmanRprevented not only the expression of themanLMNoperon but also glucose-mediated repression of virulence gene expression; however, repression by other carbohydrates was unaffected. Interestingly, the expression ofmanLMNinListeria innocuawas reported to require not only ManR but also the Crp-like transcription activator Lin0142. Unlike Lin0142, theL. monocytogeneshomologue, Lmo0095, is not required formanLMNexpression; its absence rather stimulatesmanexpression.IMPORTANCEListeria monocytogenesis a human pathogen causing the foodborne disease listeriosis. The expression of most virulence genes is controlled by the transcription activator PrfA. Its activity is strongly repressed by carbohydrates, including glucose, which is transported intoL. monocytogenesmainly via a mannose/glucose-specific phosphotransferase system (PTSMan). Expression of themanoperon is regulated by the transcription activator ManR, the activity of which is controlled by a second, low-efficiency PTS of the mannose family, which functions as glucose sensor. Here we demonstrate that the EIIBMpocomponent plays a dual role in ManR regulation: it inactivates ManR by phosphorylating its His871 residue and stimulates ManR by interacting with its two C-terminal domains.
The Genesis of Mesovortices within a Real-Data Simulation of a Bow Echo System
Authors: Xu Xin , Xue Ming , Wang Yuan 
Published: February 2015

Abstract
The genesis of two mesovortices (MVs) within a real-data, convection-resolving simulation of the 8 May 2009 central U.S. bow echo system is studied. Both MVs form near the bow apex but differ distinctively in intensity, lifetime, and damage potential. The stronger and longer-lived mesovortex, MVa, stays near the bow apex where the system-scale rear-inflow jet (RIJ) is present. The descending RIJ produces strong downdrafts and surface convergence, which in turn induce strong vertical stretching and intensification of MVa into an intense mesovortex. In contrast, the weaker and shorter-lived mesovortex, MVb, gradually moves away from the bow apex, accompanied by localized convective-scale downdrafts.
Lagrangian circulation and vorticity budget analyses reveal that the vertical vorticity of MVs in general originate from the tilting of near-surface horizontal vorticity, which is mainly created via surface friction. The circulation of the material circuit that ends up to be a horizontal circuit at the foot of the MVs increases as the frictionally generated horizontal vortex tubes pass through the tilted material circuit (tilted following backward trajectories defining the material circuit) surface, especially in the final few minutes prior to mesovortex genesis. The tilted material circuit becomes horizontal at the MV foot, turning associated horizontal vorticity into vertical. The results show at least qualitatively that, in addition to baroclinicity, surface friction can also have significant contributions to the generation of low-level MVs, which was not considered in previous MV studies.
Comments on “The Tropospheric Land–Sea Warming Contrast as the Driver of Tropical Sea Level Pressure Changes”
Authors: Makarieva A. M. , Gorshkov V. G. , Nefiodov A. V. , Sheil D. , Nobre A. D. , Li B.-L. 
Published: February 2015

AbstractIn their paper “The tropospheric land–sea warming contrast as the driver of tropical sea level pressure changes,” Bayr and Dommenget proposed a simple model of temperature-driven air redistribution to quantify the ratio between changes of sea level pressure ps and mean tropospheric temperature Ta in the tropics. This model assumes that the height of the tropical troposphere is isobaric. Here problems with this model are identified. A revised relationship between ps and Ta is derived governed by two parameters—the isobaric and isothermal heights—rather than just one. Further insight is provided by the earlier model of Lindzen and Nigam, which was the first to use the concept of isobaric height to relate tropical ps to air temperature, and they did this by assuming that isobaric height is always around 3 km and isothermal height is likewise near constant. Observational data, presented here, show that neither of these heights is spatially universal nor does their mean values match previous assumptions. Analyses show that the ratio of the long-term changes in ps and Ta associated with land–sea temperature contrasts in a warming climate—the focus of Bayr and Dommenget’s work—is in fact determined by the corresponding ratio of spatial differences in the annual mean ps and Ta. The latter ratio, reflecting lower pressure at higher temperature, is significantly impacted by the meridional pressure and temperature differences. Considerations of isobaric heights are shown to be unable to predict either spatial or temporal variation in ps. As noted by Bayr and Dommenget, the role of moisture dynamics in generating sea level pressure variation remains in need of further theoretical investigations.
Sensitivity of Antarctic Circumpolar Current Transport and Eddy Activity to Wind Patterns in the Southern Ocean
Authors: Langlais Clothilde E. , Rintoul Stephen R. , Zika Jan D. 
Published: February 2015

AbstractThe Southern Hemisphere westerly winds have intensified in recent decades associated with a positive trend in the southern annular mode (SAM). However, the response of the Antarctic Circumpolar Current (ACC) transport and eddy field to wind forcing remains a topic of debate. This study uses global eddy-permitting ocean circulation models driven with both idealized and realistic wind forcing to explore the response to interannual wind strengthening. The response of the barotropic and baroclinic transports and eddy field of the ACC is found to depend on the spatial pattern of the changes in wind forcing. In isolation, an enhancement of the westerlies over the ACC belt leads to an increase of both barotropic and baroclinic transport within the ACC envelope, with lagged enhancement of the eddy kinetic energy (EKE). In contrast, an increase in wind forcing near Antarctica drives a largely barotropic change in transport along closed f/H contours (“free mode”), with little change in eddy activity. Under realistic forcing, the interplay of the SAM and the El Niño–Southern Oscillation (ENSO) influences the spatial distribution of the wind anomalies, in particular the partition between changes in the wind stress over the ACC and along f/H contours. This study finds that the occurrence of a negative or positive ENSO during a positive SAM can cancel or double the wind anomalies near Antarctica, altering the response of the ACC and its eddy field. While a negative ENSO and positive SAM favors an increase in EKE, a positive ENSO and positive SAM lead to barotropic transport changes and no eddy response.
The Role of Closed Gyres in Setting the Zonal Transport of the Antarctic Circumpolar Current
Authors: Nadeau Louis-Philippe , Ferrari Raffaele 
Published: February 2015

AbstractEddy-permitting simulations are used to show that basinlike gyres can be observed in the large-scale barotropic flow of a wind-driven channel with a meridional topographic ridge. This is confirmed using both two-layer quasigeostrophic and 25-level primitive equation models at high horizontal resolution. Comparing results from simulations with and without the topographic ridge, it is shown that the zonal baroclinic transport in the channel increases with increasing wind stress when the bottom topography is flat but not when there is a meridional ridge. The saturation of transport for increasing wind occurs in conjunction with the development of recirculating gyres in the large-scale barotropic streamfunction. This suggests that the total circulation can be thought of as a superposition of a gyre mode (which has zero circumpolar transport) and a free circumpolar mode (which contains all of the transport). Basinlike gyres arise in the channel because the topography steers the barotropic streamlines and supports a frictional boundary layer similar to the more familiar ones observed along western boundaries. The gyre mode is thus closely linked with the bottom form stress exerted by the along-ridge flow and provides the sink for the wind momentum input. In this framework, any increase in wind forcing spins a stronger gyre as opposed to feeding the circumpolar transport. This hypothesis is supported with a suite of experiments where key parameters are carried over a wide range: wind stress, wind stress curl, ridge height, channel length, and bottom friction.
Socio-economic Patterns in Inpatient Care Utilisation in India: Is the Income Effect Withering?
Authors: Ghosh Soumitra 
Published: February 2015

Though a few studies are available with regard to socio-economic differentials in health care utilisation in India, no attempt has been made to understand the underlying decision-making process in health care utilisation. Therefore, in this article, an attempt is made to examine the utilisation of inpatient care in India, focusing on the socio-economic determinants of the extent of inpatient care use. The health care utilisation model adopted by Manning et al., (1987, American Economic Review, 77(3), 251–77), and Pohlmeier and Ulrich (1995, The Journal of Human Resources, 30(2), 339–61) was employed for studying the above objective. Cross-sectional data are taken from National Sample Survey Organization’s 60th round (2004) survey on ‘morbidity and health care’. While a two-part (double-hurdle) model is estimated for the frequency of hospitalisations, a zero-truncated negative binomial regression model is applied for the length of stay (LOS) in a hospital. The results suggest that controlling other factors, people from richer households were more likely to seek hospital admission and use inpatient care more frequently than their poorer counterparts, consistent with the supposition that rich people have greater access to health care. However, the analyses suggest that with respect to income, equity has been achieved for the LOS in the hospital for individuals suffering from various diseases. This means that income inequity exists at the time of hospital admission but once they are admitted, the duration of stay at hospital is no longer determined by their economic status. However, this requires careful interpretation because it is quite likely that poor people may have been forced to sell off assets or borrow money for meeting the cost of hospitalisation for longer duration of stay. The above argument is strengthened by the fact that when socio-economic status is measured by education, inequity continues to persist, with illiterates having longer LOSs in the hospital. The policy measure that the government could take to improve the access of quality health care services for the poor is to strengthening the public health system through enhanced investments in the National Health Mission. JEL Classification: I140
Financial Knowledge and Behaviour of Working Adults in Malaysia
Authors: Loke Yiing Jia 
Published: February 2015

Financial education is a key intervention strategy in improving consumers’ financial knowledge, but exogenous factors such as cultural differences and socio-economic factors can also affect the levels of financial knowledge. On using an ordered probit model on primary data comprising working adults in Malaysia, this study found that financial illiteracy cuts across gender and age but education, ethnicity, type of profession and the availability of government pension have significant effects on levels of financial knowledge. Furthermore, while most financial behaviour such as budgeting, investments and preparing for financial emergencies is significantly affected by levels of financial knowledge, being in financial distress is not affected by financial knowledge. JEL Classification: D14, D91