silkski/ENERAD huggingface dataset:
The primary objective of the UEET ( Ultra - Efficient Engine Technology ) Program is to address two of the most critical propulsion issues : performance / efficiency and reduced emissions . High performance , low emissions engine systems will lead to significant improvement in local air quality , minimum impact on ozone depletion and level to an overall reduction in aviation contribution to global warming . The Materials and Structures for High Performance project will develop and demonstrate advanced high temperature materials to enable high - performance , high efficiency , and environmentally compatible propulsion systems .
This proposal fits within the programmatic long - term development direction for turbine engine seals of the Seal Team of the Mechanical Component Branch . The intended work concerns the further development of the Finger Seal concept which is a compliant passive - adaptive seal meant to mitigate ( and eventually replace ) the shortcomings of the entire class of rigid seals used today ( labyrinth , honeycomb , mechanical face seals ) in the gas turbines and compressors ,
Test results show that separation failure in co - cured skin / stiffener interfaces is characterized by dense networks of interacting cracks and crack path migrations that are not present in standard characterization tests for delamination . These crack networks result in measurable large - scale and sub - ply - scale R curve toughening mechanisms , such as fiber bridging , crack migration , and crack delving . Consequently , a number of unknown issues exist regarding the level of analysis detail that is required for sufficient predictive fidelity . The objective of the present paper is to examine some of the difficulties associated with modeling separation failure in stiffened composite structures . A procedure to characterize the interfacial material properties is proposed and the use of simplified models based on empirical interface properties is evaluated .
Current rover designs use on - board manipulators to enhance their capabilities for planetary exploration and in - situ science . In this paper , we describe how these manipulators can be   used to perform two types of operations : rock sample aquisition for return to earth and instrument placement for in - situ science meausrements .
Understanding and using the data and knowledge encoded in semantic web documents requires an inference engine . F - OWL is an inference engine for the semantic web language OWL language based on F - logic , an approach to defining frame - based systems in logic . F - OWL is implemented using XSB and Flora-2 and takes full advantage of their features . We describe how F - OWL computes ontology entailment and compare it with other description logic based approaches . We also describe TAGA , a trading agent environment that we have used as a test bed for F - OWL and to explore how multiagent systems can use semantic web concepts and technology .
One of the major factors in acceptance of aircraft operating in urban areas is noise . In this work , we build on a framework for trajectory generation in order to account for limits on acousticmetrics at one ormore observer locations . The spatial trajectories are generated using Bézier polynomials and satisfy dynamic , acoustic , and mission constraints . The trajectories also guarantee spatial or temporal separation between vehicles for multi - vehicle operations . A simulation example is provided that demonstrates the reduction in noise levels at a set of measurement locations .
After being selected to the astronaut office , crewmembers go through an initial two year training flow , astronaut candidacy , where they learn the basic skills necessary for spaceflight . While the bulk of astronaut candidate training currently centers on the multiple subjects required for ISS operations ( EVA skills , Russian language , ISS systems , etc . ) , training also includes geoscience training designed to train crewmembers in Earth observations , teach astronauts about other planetary systems , and provide field training designed to investigate field operations and boost team skills . This training goes back to Apollo training and has evolved to support ISS operations and future exploration missions .
The overall objective of the functional task test ( FTT ) is to correlate spaceflight - induced physiological adaptations with changes in performance of high priority exploration mission - critical tasks . This presentation will focus on the recovery from fall / stand test ( RFST ) , which measures the cardiovascular response to the transition from the prone posture ( simulated fall ) to standing in normal gravity , as well as heart rate ( HR ) during 11 functional tasks . As such , this test describes some aspects of spaceflight - induced cardiovascular deconditioning and the course of recovery in Space Shuttle and International Space Station ( ISS ) astronauts . The sensorimotor and neuromuscular components of the FTT are described in two separate abstracts : Functional Task Test 1 and 3 .
The capability of future X - ray telescopes depends on the quality of their Point Spread Function ( PSF ) and the size of their field of view . Traditional designs , such as Wolter , and Wolter - Schwarzschild telescopes are stigmatic on the optical axis but their PSF degrades rapidly off - axis . At the optimal focal surface , their PSFs can be significantly improved . We present a simple optimization process for Wolter ( W ) , Wolter - Schwarzschild ( WS ) and Hyperboloid - Hyperboloid ( HH ) telescopes that substantially improves the off - axis PSF for either narrow or wide field of view applications . In this paper , we will compare the optical performance of conventional and optimized W- , WS- , and HH - telescopes for a wide range of telescope diameters that can be used to build up future x - ray telescopes .
Planar laser - induced fluorescence ( PLIF ) is used to visualize the flame structure via OH , NO , and fuel imaging in kerosene- burning gas turbine combustor flame tubes . When compared to simple gaseous hydrocarbon flames and hydrogen flames , flame tube testing complexities include spectral interferences from large fuel fragments , unknown turbulence interactions , high pressure operation , and the concomitant need for windows and remote operation . Complications of these and other factors as they apply to image analysis are considered . Because both OH and gas turbine engine fuels ( commercial and military ) can be excited and detected using OH transition lines , a narrowband and a broadband detection scheme are compared and the benefits and drawbacks of each method are examined .
A hyperbolic grid generation method is used to generate prismatic grids and an approach using prismatic grids to solve the Euler equations is presented . The theory of the stability and feasibility of the hyperbolic grid generation method is presented . The hyperbolic grid generation method of Steger et al for structured grids is applied to a three dimensional triangularized surface definition to generate a grid that is unstructured on each successive layer . The grid , however , retains structure in the body - normal direction and has a computational cell shaped like a triangular prism . In order to take advantage of the structure in the normal direction , a finite - volume scheme that treats the unknowns along the normal direction implicitly is introduced and the flow over a sphere is simulated .
Electric , hybrid - electric , and turbo - electric distributed propulsion technologies and concepts are beginning to gain traction in the aircraft design community , as they can provide improvements in operating costs , noise , fuel consumption , and emissions compared to conventional internal combustion or Brayton - cycle powered vehicles . NASA is building multiple demonstrators and testbeds to buy down airworthiness and flight safety risks for these new technologies , including X-57 Maxwell , HEIST , Airvolt , and NEAT .
Glenn Research Center develops advanced diagnostic techniques to measure surface and flow properties in research facilities . We support a variety of aerospace propulsion applications : Shuttle , X-33 , X-43 , ISS , and research engine components : inlets , compressors , combustors , nozzles . We are developing a suite of instrumentation specifically for 3rd Generation Reusable Launch Vehicle testing .
Laboratory testing was conducted to evaluate safety concerns for integrally - stiffened tanks that were found to have developed cracks during pressurization testing . Cracks occurred at fastener holes where additional stiffeners were attached to the integrally - stiffened tank structure . Tests were conducted to obtain material properties and to reproduce the crack morphologies that were observed in service to help determine if the tanks are safe for operation . Reproducing the cracking modes observed during pressurization testing required a complex loading state involving both a tensile load in the integrally - stiffened structure and a pin - load at a fastener hole .
A series of low speed ( M less than 0.2 ) experiments using University of Washington Fib-07 Pressure Sensitive Paint ( PSP ) have been conducted at NASA Ames on a NACA 0012 airfoil . Significant improvements in results have been shown : PSP calibration errors of the improved data ( with pressure taps as a reference ) now agree with theoretical error limits . Additional measurements on the 0012 airfoil using Temperature Sensitive Paint have been made . These TSP measurements now fully quantify the impact of temporal temperature changes on model surfaces on PSP measurements . Finally , simultaneous PSP - TSP measurements have been performed , allowing in - situ temperature correction of PSP data with good results .
We investigate jet formation in black - hole systems using 3 - D General Relativistic Particle - In - Cell ( GRPIC ) and 3 - D GRMHD simulations . GRPIC simulations , which allow charge separations in a collisionless plasma , do not need to invoke the frozen condition as in GRMHD simulations . 3 - D GRPIC simulations show that jets are launched from Kerr black holes as in 3 - D GRMHD simulations , but jet formation in the two cases may not be identical . Comparative study of black hole systems with GRPIC and GRMHD simulations with the inclusion of radiate transfer will further clarify the mechanisms that drive the evolution of disk - jet systems .
The NASA Langley 8 - Foot High Temperature Tunnel has recently been modified to produce a unique testing capability for hypersonic airbreathing propulsion systems . Prior to these modifications , the facility was used primarily for aerothermal loads and structural verification testing at true flight total enthalpy conditions for Mach numbers between 6 and 7 . One of the recent modifications was an oxygen replenishment system which allows operating airbreathing propulsion systems to be tested at true flight total enthalpies . Following the modifications to the facility , calibration runs were performed at total enthalpies corresponding to flight Mach numbers of 6.3 and 6.8 to establish the flow characteristics of the facility with its new capabilities . The results of this calibration , as well as modifications to tunnel combustor hardware prior to calibration to improve tunnel flow quality , are described in this paper .
Presented by Lissauer et al . ( 2009 , Icarus 199 , 338 ) are used to test the model of capture of Jupiter 's irregular satellites within proto - Jupiter 's distended and thermally - supported envelope . We find such capture highly unlikely , since the envelope shrinks too slowly for a large number of moons to be retained , and many of those that would be retained would orbit closer to the planet than do the observed Jovian irregulars . Our calculations do not address ( and therefore do not exclude ) the possibility that the irregular satellites were captured as a result of gas drag within a circumjovian disk . Support for this research from NASA Outer Planets Research Program is gratefully acknowledged .
In this viewgraph presentation , information is provided on the numerical simulation of a turbulence event encountered by NASA Langley 's B-757 while conducting flight tests in areas at high risk for severe turbulence . Specific details on the Terminal Area Simulation System ( TASS ) show how the simulation is devised . The 100 m simulation was able to observe large - scale features .
The effect on speech intelligibility was measured for speech where talkers reading Diagnostic Rhyme Test material were exposed to 0.7 g whole body vibration to simulate space vehicle launch . Across all talkers , the effect of vibration was to degrade the percentage of correctly transcribed words from 83 % to 74 % . The magnitude of the effect of vibration on speech communication varies between individuals , for both talkers and listeners . A worst case scenario for intelligibility would be the most sensitive listener hearing the most sensitive talker ; one participant s intelligibility was reduced by 26 % ( 97 % to 71 % ) for one of the talkers .
This paper presents the formulation of a Lyapunov function for an exponentially stable linear timevarying ( LTV ) system using a well - defined PD - spectrum and the associated PD - eigenvectors . It provides a bridge between the first and second methods of Lyapunov for stability assessment , and will find significant applications in the analysis and control law design for LTV systems and linearizable nonlinear time - varying systems .
The Contact Dynamics Simulation Laboratory ( CDSL ) of the Marshall Space Flight Center provides for refined hardware - in - the - loop real - time simulation of docking and berthing mechanisms and associated control systems . This facility is employed to verify the performance of docking / berthing mechanisms during Earth - orbit operations , determine the capture envelope of dockingherthing devices , measure contact loads at vehicle interfaces , and evaluate visual cues for man - in - the - loop operations . The CDSL has developed test verified analytical models of such systems as the ISS Common Berthing Mechanism and HST Three Point Docking Mechanism . This paper will describe the modeling and test techniques employed at the CDSL and present results from recent programs .
During the late summer , the author sailed to the Antarctic South Shetland Islands to survey the microorganisms living in marine ( tidal pools ) and freshwater ( moss saturated with snow melt ) environmental niches . Equipped with a microscope to take video of samples within hours of collection to capture a pristine condition , the authors found a dense and diverse ecology that included species with unique patterns of locomotion . Capturing the organism 's movement expedited identification , but it also showed the dynamic way each organism 's mobility fit together like a puzzle to create a complex ecosystem .
In the early years of powered flight , the National Advisory Committee on Aeronautics in the United States produced three reports describing a method of analysis of aircraft accidents . The first report was published in 1928 ; the second , which was a revision of the first , was published in 1930 ; and the third , which was a revision and update of the second , was published in 1936 . This paper describes the contents of these reports , and compares the method of analysis proposed therein to the methods used today .