SCAN_32-01

32-01 COMMUNICATION SATELLITES
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

32-02 COMMUNICATION EQUIPMENT
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

32-03 COMMUNICATION SYSTEMS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Unobtrusive Social Network Data From Email
Document ID:
20090037127
Report #:
AD-A505804
Available Online:
http://hdl.handle.net/100.2/ADA505804
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
McCulloh, Ian (Military Academy) Ring, Benjamin (Military Academy) Frantz, Terrill L. (Carnegie-Mellon Univ.) Carley, Kathleen M. (Carnegie-Mellon Univ.)
Published:
20081201
Source:
Military Academy (West Point, NY United States)
Pages:
7
Contract #:
None
Abstract:
Email provides a rich source of longitudinal social network data that can be used for applications ranging from command and control, to military intelligence, to basic social science research. This project reviews several methods available to extract email network data and compares them in terms of data quality and convenience of collection. In general, it is preferable to obtain email data directly from the central SMTP email server. In situations where this is not possible, alternative approaches presented here can be useful. These techniques for analyzing email data have been automated in the Organizational Risk Analyzer (ORA) software, which is freely available to DoD and academia.
Language:
English
Notes:
Presented at the Army Science Conference (26th) Held in Orlando, Florida on 1-4 December 2008. Published in the Proceedings of the Army Science Conference (26th), December 2008 Army Science Conference (26th) Orlando, FL 1-4 Dec. 2008

Title:
Detection, Identification, Location, and Remote Sensing Using SAW RFID Sensor Tags
Document ID:
20090037326
Report #:
JSC-CN-19047
Available Online:
http://hdl.handle.net/2060/20090037326
Sales Agency:
CASI Hardcopy A03 Copyright
Author(s):
Barton, Richard J. (NASA Johnson Space Center) Kennedy, Timothy F. (NASA Johnson Space Center) Williams, Robert M. (NASA Johnson Space Center) Fink, Patrick W. (NASA Johnson Space Center) Ngo, Phong H. (NASA Johnson Space Center)
Published:
20090101
Source:
NASA Johnson Space Center (Houston, TX, United States)
Pages:
36
Contract #:
None
Abstract:
The Electromagnetic Systems Branch (EV4) of the Avionic Systems Division at NASA Johnson Space Center in Houston, TX is studying the utility of surface acoustic wave (SAW) radiofrequency identification (RFID) tags for multiple wireless applications including detection, identification, tracking, and remote sensing of objects on the lunar surface, monitoring of environmental test facilities, structural shape and health monitoring, and nondestructive test and evaluation of assets. For all of these applications, it is anticipated that the system utilized to interrogate the SAW RFID tags may need to operate at fairly long range and in the presence of considerable multipath and multiple-access interference. Towards that end, EV4 is developing a prototype SAW RFID wireless interrogation system for use in such environments called the Passive Adaptive RFID Sensor Equipment (PARSED) system. The system utilizes a digitally beam-formed planar receiving antenna array to extend range and provide direction-of-arrival information coupled with an approximate maximum-likelihood signal processing algorithm to provide near-optimal estimation of both range and temperature. The system is capable of forming a large number of beams within the field of view and resolving the information from several tags within each beam. The combination of both spatial and waveform discrimination provides the capability to track and monitor telemetry from a large number of objects appearing simultaneously within the field of view of the receiving array. In this paper, we will consider the application of the PARSEQ system to the problem of simultaneous detection, identification, localization, and temperature estimation for multiple objects. We will summarize the overall design of the PARSEQ system and present a detailed description of the design and performance of the signal detection and estimation algorithms incorporated in the system. The system is currently configured only to measure temperature (jointly with range and tag ID), but future versions will be revised to measure parameters other than temperature as SAW tags capable of interfacing with external sensors become available. It is anticipated that the estimation of arbitrary parameters measured using SAW-based sensors will be based on techniques very similar to the joint range and temperature estimation techniques described in this paper.
Language:
English
Notes:
2010 IEEE Aerospace Conference Big Sky, MT 6-13 Mar. 2010

Title:
"Fly-by-Wireless" Vehicles and Evaluations of ISA 100 Applications to Space-Flight
Document ID:
20090037545
Report #:
JSC-CN-19016
Available Online:
http://hdl.handle.net/2060/20090037545
Sales Agency:
CASI Hardcopy A03 No Copyright
Author(s):
Studor, George F. (NASA Johnson Space Center)
Published:
20091008
Source:
NASA Johnson Space Center (Houston, TX, United States)
Pages:
26
Contract #:
None
Abstract:
"Fly-by-Wireless" (What is it?) Vision: To minimize cables and connectors and increase functionality across the aerospace industry by providing reliable, lower cost, modular, and higher performance alternatives to wired data connectivity to benefit the entire vehicle/program life-cycle. Focus Areas: 1. System Engineering and Integration to reduce cables and connectors. 2. Provisions for modularity and accessibility in the vehicle architecture. 3. Develop Alternatives to wired connectivity (the "tool box").NASA and Aerospace depend more and more on cost-effective solutions that can meet our requirements. ISA-100.11 a is a promising new standard and NASA wants to evaluate it. NASA should be involved in understanding and contributing to other ISA-100 efforts that contribute to "Fly-by-Wireless" and it's objectives. ISA can engage other aerospace groups that are working on similar goals and obtain more aerospace industry perspective.
Language:
English
Notes:
ISA Expo, Wireless for Aerospace Applications Houston, TX 8 Oct. 2009

32-04 TELEMETRY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

32-05 RADIO NOISE
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

32-06 COMMUNICATION THEORY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-01 RADAR EQUIPMENT
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Ocean, Land and Meteorology Studies Using Space-Based Lidar Measurements
Document ID:
20090037431
Report #:
LF99-9425, Paper-626-301
Available Online:
http://hdl.handle.net/2060/20090037431
Sales Agency:
CASI Hardcopy A01 No Copyright
Author(s):
Hu,Yongxiang (NASA Langley Research Center)
Published:
20091017
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
4
Contract #:
None
Abstract:
CALIPSO's main mission objective is studying the climate impact of clouds and aerosols in the atmosphere. CALIPSO also collects information about other components of the Earth's ecosystem, such as oceans and land. This paper introduces the physics concepts and presents preliminary results for the valueadded CALIPSO Earth system science products. These include ocean surface wind speeds, column atmospheric optical depths, ocean subsurface backscatter, land surface elevations, atmospheric temperature profiles, and A-train data fusion products.
Language:
English
Notes:
5th WSEAS International Conference on Remote Sensing (REMOTE'09) Genova 17-19 Oct. 2009

33-02 SEMICONDUCTORS AND TRANSISTORS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-03 ANTENNAS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-04 ELECTRONIC COMPONENTS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-05 CIRCUITRY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Chip Generators Study
Document ID:
20090037444
Report #:
AD-A505937, AFRL-RY-WP-TR-2009-1041
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Horowitz, Mark (Stanford Univ.) Stark, Don (Stanford Univ.) Asgar, Zain (Stanford Univ.) Azizi, Omid (Stanford Univ.) Hameed, Rehan (Stanford Univ.) Qadeer, Wajahat (Stanford Univ.) Shacham, Ofer (Stanford Univ.) Wachs, Megan (Stanford Univ.)
Published:
20081201
Source:
Stanford Univ. (Stanford, CA United States)
Pages:
33
Contract #:
FA8650-08-C-7829
Abstract:
This report explores a new way to think about designing digital systems, creating chip generators rather than chips, to resolve the crisis facing the chip industry: the need for high energy efficiency pushes us to create customized computing devices tailored to the user's application, while the high cost of design pushes us to using generic computing solutions. Our research indicates that customized solutions can be orders of magnitude better, and that creating a chip generator requires changing the way we think and code hardware, but should be feasible.
Language:
English
Notes:
Sponsored in part by DARPA IPTO

33-06 ELECTRICAL EQUIPMENT
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-07 AMPLIFIERS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-08 FEEDBACK AND CONTROL THEORY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-09 ELECTROMAGNETIC RADIATION
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-10 MICROELECTRONICS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-11 MICROWAVE AND SUBMILLIMETER WAVE TECHNOLOGY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

33-12 MAGNETISM
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

34-01 BOUNDARY LAYER TECHNOLOGY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Tomographic Particle Image Velocimetry and Its Application to Turbulent Boundary Layers
Document ID:
20090037144
Report #:
PB2009-114445
Sales Agency:
National Technical Information Service (NTIS) No Copyright
Author(s):
Elsinga, G. E.
Published:
20080101
Source:
Technische Hogeschool (Delft, Netherlands)
Pages:
154
Contract #:
None
Abstract:
Tomographic Particle Image Velocimetry is a new experimental method developed to study three-dimensional motion in turbulent flows. The technique is an extension of standard PIV and makes use of several simultaneous views of illuminated tracer particles and their three-dimensional reconstruction as a light intensity distribution by means of tomography. The reconstructed tomogram pair is then analyzed by means of 3D cross-correlation returning the three-component velocity vector distribution over the measurement volume. The principles and details of the tomographic algorithm are discussed and a parametric study is carried out by to identify the most important parameters governing the experimental setup and to show their effect on the reconstruction accuracy. The capability of the technique in real experimental conditions is assessed with the measurement of the turbulent flow in the near wake of a circular cylinder. Next, this new technique has been applied to study the three-dimensional coherent structures in turbulent boundary layers.
Language:
English

34-03 FLUIDICS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

34-04 FLUID FLOW
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
A High-Order Transport Scheme for Collisional-Radiative and Nonequilibrium Plasma
Document ID:
20090037510
Report #:
AD-A505555, AFRL-RZ-ED-TP-2009-028
Available Online:
http://hdl.handle.net/100.2/ADA505555
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Kapper, Michael G. (Ohio State Univ.)
Published:
20090206
Source:
Ohio State Univ. (Columbus, OH United States) Texas Research Inst., Inc. (Austin, TX, United States)
Pages:
214
Contract #:
None
Abstract:
A series of shock tube experiments performed in the 1970s at the Institute for Aerospace Studies, University of Toronto, led in the discovery of instabilities in relaxing shock structures in noble gases under hypervelocity conditions. The instabilities were oscillatory in nature and found to affect the entire shock structure including the translational front, induction zone, and electron avalanche. Theoretical models were first developed in order to reproduce the length and time scales of the observed quasi-equilibrium state, and later extended to include unsteady plasma-dynamic simulations that verified the influence of pressure oscillations in one dimension. Despite these attempts, a complete explanation for the oscillations nor a quantitative analysis of the multi-dimensional shock structure has been provided to date. This dissertation builds upon previous modeling efforts, extending the numerical simulations to a high level of accuracy and detail so that coupling of complex wave phenomena and nonequilibrium effects can be well resolved. This has necessitated the development of a numerical capability aimed at relaxing shock layers and other unsteady, high-enthalpy nonequilibrium plasmas and is the focus of much of this work. The plasma is described as a two-temperature, single fluid with the electronic states convected as separate species. Solution of the convective transport is handled via upwind shock-capturing techniques, extended to third-order on general curvilinear meshes.
Language:
English
Notes:
Sponsored in part by Air Force Office of Scientific Research (AFOSR) laboratory task no. 02PR05COR

Title:
An Overview of the NASA FAP Hypersonics Project Airbreathing Propulsion Research
Document ID:
20090037583
Report #:
LF99-9121
Available Online:
http://hdl.handle.net/2060/20090037583
Sales Agency:
CASI Hardcopy A02 No Copyright
Author(s):
Auslender, A. H. (NASA Langley Research Center) Suder, Kenneth L. (NASA Glenn Research Center) Thomas, Scott R. (NASA Glenn Research Center)
Published:
20091019
Source:
NASA Glenn Research Center (Cleveland, OH, United States)
Pages:
7
Contract #:
None
Abstract:
The propulsion research portfolio of the National Aeronautics and Space Administration Fundamental Aeronautics Program Hypersonics Project encompasses a significant number of technical tasks that are aligned to achieve mastery and intellectual stewardship of the core competencies in the hypersonic-flight regime. An overall coordinated programmatic and technical effort has been structured to advance the state-of-the-art, via both experimental and analytical efforts. A subset of the entire hypersonics propulsion research portfolio is presented in this overview paper. To this end, two programmatic research disciplines are discussed; namely, (1) the Propulsion Discipline, including three associated research elements: the X-51A partnership, the HIFiRE-2 partnership, and the Durable Combustor Rig, and (2) the Turbine-Based Combine Cycle Discipline, including three associated research elements: the Combined Cycle Engine Large Scale Inlet Mode Transition Experiment, the small-scale Inlet Mode Transition Experiment, and the High-Mach Fan Rig.
Language:
English
Notes:
16th AIAA/DLR/DGLR International Space Planes and Hypersonic Systems and Technologies Conference Bremen 19-23 Oct. 2009

34-05 COMBUSTION PHYSICS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

34-06 HEAT TRANSFER, BASIC
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

34-07 REENTRY HEAT TRANSFER
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

34-08 THERMAL PROTECTION
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

34-09 ABLATION
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

34-10 CRYOGENICS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Optimization of the SRF Cavity Design for the CEBAF 12 GEV Uugrade
Document ID:
20090037535
Report #:
DE2008-923386, JLAB-ACC-07-790, DOE/OR/23177-0311
Sales Agency:
National Technical Information Service (NTIS) No Copyright
Author(s):
Reece, C. Daly, E. Henry, J. Hicks, W. Preble, J.
Published:
20080212
Source:
Jefferson (Thomas) Lab. Computer Center (Newport News, VA, United States)
Pages:
4
Contract #:
AC05-06OR23177
Abstract:
Based on initial testing of the HG and LL 7-cell cavities in the prototype cryomodule Renascence, several opportunities for improved optimization were identified. The HOM damping configuration was refined so as to meet the requirements for damping key dipole modes while simultaneously dramatically reducing risk of HOM pickup probe heating and also creating beamline clearance for mounting the tuner to stainless steel helium vessel endplates (rather than NbTi/Ti transitions to a titanium helium vessel). Code modeling and bench measurements were performed. The new design maintains the 7-cell LL cells and incorporates a brazed transition between Nb and the SS helium vessel. The resulting configuration is now called the C100 design. Cavity design details as well as vertical dewar and horizontal test bed performance are presented.
Language:
English
Notes:
Sponsored by Department of Energy, Washington, DC.

35-01 PHOTOGRAPHY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

35-02 INFRARED TECHNOLOGY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

35-03 INSTRUMENT STANDARDS AND CALIBRATION TECHNIQUES
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

35-04 TEMPERATURE MEASUREMENT
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

35-05 PRESSURE MEASUREMENT
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

35-06 DISPLAY SYSTEMS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

35-07 DATA RECORDING
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Improvements to a Major Digital Archive of Seismic Waveforms from Nuclear Explosions: The Borovoye Seismogram Archive
Document ID:
20090037588
Report #:
AD-A505432, AFRL-RV-HA-TR-2009-1068
Available Online:
http://hdl.handle.net/100.2/ADA505432
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Baker, Diane (Los Alamos National Lab.) Kim, Won-Young (Lamont-Doherty Geological Observatory) Patton, Howard (Los Alamos National Lab.) Randall, George (Los Alamos National Lab.) Richards, Paul (Lamont-Doherty Geological Observatory)
Journal:
Proceedings of the 2009 Monitoring Research Review (MRR) on Ground-Based Nuclear Explosion Monitoring Technologies, Volume: Volume 1 , Page: 12-21
Published:
20090930
Source:
Los Alamos National Lab. (Albuquerque, NM, United States)
Pages:
11
Contract #:
FA8718-07-C-0004
Abstract:
We are in the final year of a three-year project to generate in modern form an easily usable archive of digital seismograms derived from regional waveforms recorded at the Borovoye Observatory (BRV), northern Kazakhstan, over a thirty-year period going back to 1966 and forward to the time when state-of-the-art sensors and dataloggers were introduced at this site by several different western groups. The BRV seismograms, which include multi-channel regional signals from 350 underground nuclear test explosions carried out in Eurasia, were made generally available to western scientists in 2001, but only as copies of the bits in the original digital waveforms. Those copies contain large numbers of glitches and did not include instrument responses for approximately two-thirds of the events. Our project is a joint effort by scientists at Lamont-Doherty Earth Observatory of Columbia University (LDEO) and at Los Alamos National Laboratory (LANL). The work of deglitching all the Borovoye digital seismograms has now been completed (at LANL). The initial work of determining instrument responses for the many different channels of the three different digital systems used at Borovoye over the thirty-year period has also been completed (at LDEO). Three different sets of Soviet-style instruments and recording systems were used at BRV from 1966 to 1996. LANL scientists had processed the BRV regional signals for 210 nuclear tests (1355 traces) before the present project started, mainly those for which instrument responses were available (the TSG system). In this project LANL processed the waveforms of the so-called SS system for 148 nuclear tests (1679 traces), some of which were also recorded on the TSG system, and these have now been processed too (281 traces). The remaining main block of events was recorded on the oldest, so-called KOD, system, which was used in operations beginning in 1966 and which operated continuously from 1967 to 1973.
Language:
English
Notes:
2009 Monitoring Research Review (MRR) on Ground-Based Nuclear Explosion Monitoring Technologies Tucson, AZ 21-23 Sep. 2009

Title:
Frequency-Dependent Nature of Pn in Western China
Document ID:
20090037590
Report #:
AD-A505418, AFRL-RV-HA-TR-2009-1079
Available Online:
http://hdl.handle.net/100.2/ADA505418
Sales Agency:
Defense Technical Information Center (DTIC) No Copyright
Author(s):
Nowack, Robert L. (Purdue Univ.) Chen, Wang-Ping (Illinois Univ.) Tseng, Tai-Lin (Illinois Univ.)
Journal:
Proceedings of the 2009 Monitoring Research Review (MRR) on Ground-Based Nuclear Explosion Monitoring Technologies, Volume: Volume 1 , Page: 166-175
Published:
20090930
Source:
Purdue Univ. (West Lafayette, IN United States)
Pages:
11
Contract #:
FA8718-08-C-0025
Abstract:
We are investigating Pn propagation in Western China based on regional events recorded by the Hi-CLIMB (An Integrated Study of the Himalayan-Tibetan Continental Lithosphere during Mountain Building) array in the region. Seismic attributes, including arrival times, Hilbert envelope amplitudes and instantaneous and spectral frequencies, are being used to investigate how the crustal and upper mantle velocity and attenuation structure affects the propagation of Pn arrivals in Tibet. We have constructed more than 30 high-quality regional seismic profiles, and of these, 14 events have been selected with excellent crustal and Pn arrivals for further analysis. Regional travel-times recorded by the Hi-CLIMB array are used to constrain the larger scale velocity structure in the region, with four events near the array used to constrain the crustal structure. We are also independently constraining the variation of upper mantle velocity and depth of the Moho by modeling SK-coupled shear waves at teleseismic distances. The amplitude of the SsPmP phase is particularly sensitive to upper mantle velocities when it is near critical. The initial modeling of the SsPmP phase indicates that the Moho beneath southern Lhasa is over 75 km deep with Pn velocities greater than 8 km/s. In contrast, the data sampling the Qiangtang terrene north of the Bangong-Nujiang suture shows thinner crust with Pn velocities less than 8 km/s. This is generally consistent with the results from the Pn traveltimes for regional events recorded on the Hi-CLIMB array. Nonetheless, there is additional variability of the regional travel-time data, suggesting further 3D complexities. Seismic amplitude and frequency attributes are being extracted from the crustal and Pn wave-trains, and these data are being compared with numerical and analytical results for models with upper mantle velocity gradients, which can strongly affect Pn amplitudes and frequencies. The numerical modeling is performed using approximate ray an
Language:
English
Notes:
Presented at the conference on Monitoring Research Review 2009 (MRR-2009): Ground-Based Nuclear Explosion Monitoring Technologies, held in Tucson, AZ, on 21-23 Sep 2009. Published in the proceedings of the conference, v1 p166-175, 2009. Prepared in cooperation with University of Illinois. The original document contains color images. All DTIC reproductions will be in black and white 2009 Monitoring Research Review (MRR) on Ground-Based Nuclear Explosion Monitoring Technologies Tucson, AZ 21-23 Sep. 2009

35-08 GAS FLOW MEASUREMENT
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

36-01 LASERS AND MASERS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

36-02 LASER APPLICATIONS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

37-01 BEARINGS AND GEARS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

37-02 LUBRICATION AND LUBRICANTS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

37-03 MACHINING
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Effect of HF/NH4F Etching on the Morphology of Surface Fractures on Fused Silica. Journal of Non-Crystalline Solids
Document ID:
20090037155
Report #:
PB2009-115294, LLNL-JRNL-402939
Sales Agency:
CASI Hardcopy A04 No Copyright
Author(s):
Wong, L. Suratwala, T. Feit, M. D. Miller, P. E. Steele, R. A.
Published:
20080414
Source:
California Univ., Lawrence Livermore Lab. (Livermore, CA, United States) California Univ., Lawrence Livermore Lab. (Livermore, CA, United States)
Pages:
53
Contract #:
None
Abstract:
The effects of HF/NH4F, wet chemical etching on the morphology of individual surface fractures (indentations, scratches) and of an ensemble of surface fractures (ground surfaces) on fused silica glass has been characterized. For the individual surface fractures, a series of static or dynamic (sliding) Vickers and Brinnell indenters were used to create radial, lateral, Hertzian cone and trailing indentation fractures on a set of polished fused silica substrates which were subsequently etched. After short etch times, the visibility of both surface and subsurface cracks is significantly enhanced when observed by optical microscopy. This is attributed to the removal of the polishing-induced Bielby layer and the increased width of the cracks following etching allowing for greater optical scatter at the fracture interface. The removal of material during etching was found to be isotropic except in areas where the etchant has difficulty penetrating or in areas that exhibit significant plastic deformation/densification. Isolated fractures continue to etch, but will never be completely removed since the bottom and top of the crack both etch at the same rate.
Language:
English

37-04 FRICTION AND WEAR
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

37-05 SEALS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

37-06 WELDING
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

37-07 METAL FORMING
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

37-08 PUMPS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

37-09 VACUUM TECHNOLOGY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

37-10 NONDESTRUCTIVE TESTING
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

37-11 TURBOMACHINERY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

38-01 QUALITY CONTROL AND RELIABILITY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

39-01 SHELLS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

39-02 STRESSES AND LOADS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Development and Validation of Advanced Test Methods to Generate Fatigue Crack Growth and Threshold Data for Use in Damage Tolerance Analyses
Document ID:
20090037549
Report #:
PB2008-109021, DOT/FAA/AR-04/22
Available Online:
http://hdl.handle.net/2060/20090037549
Sales Agency:
CASI Hardcopy A07 No Copyright
Author(s):
Forth, S. James, M. Johnston, W.
Published:
20080201
Source:
Federal Aviation Administration (Washington, DC, United States)
Pages:
147
Contract #:
None
Abstract:
This report describes the results of a research program that determined the damage tolerance properties of metallic propeller materials. Three alloys were selected for investigation: 2025-T6 aluminum alloy, D6AC steel, and 4340 steel. Mechanical response, fatigue stress life, and fatigue crack growth rate data are presented for all the alloys. The mechanical response can be characterized using tensile tests per American Standard Test Method (ASTM) E 8. This data was used to compute yield and ultimate stresses and the elastic modulus that can be used in damage tolerance analysis tools. Fatigue testing allowed the manufacturers to verify the integrity of their in-house data and determine if material or manufacturing changes over the past years have altered the response of the material. Furthermore, this data can be used to determine an equivalent initial flaw size if the designer wishes to relate stress-life results to damage tolerance. Most importantly, the fatigue crack growth rate response of the material must be understood to predict the life of the structure from an initial detectable flaw and to set inspection intervals. This fatigue crack growth rate data was generated using ASTM E 647 and an alternative method using compression precracking. Alternative precracking methods were used to reduce load history effects when generating threshold data, producing material response data that was unaffected by the test method.
Language:
English
Notes:
Sponsored by Federal Aviation Administration, Washington, DC. Aviation Research and Development.

39-03 STRUCTURE VIBRATION AND DAMPING
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

39-04 IMPACT PHENOMENA
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

39-05 STRUCTURAL FATIGUE
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

Title:
Development of a Composite Delamination Fatigue Life Prediction Methodology
Document ID:
20090037430
Report #:
LF99-9386
Available Online:
http://hdl.handle.net/2060/20090037430
Sales Agency:
CASI Hardcopy A02 No Copyright
Author(s):
OBrien, Thomas K. (NASA Langley Research Center)
Published:
20091019
Source:
NASA Langley Research Center (Hampton, VA, United States)
Pages:
9
Contract #:
None
Abstract:
Delamination is one of the most significant and unique failure modes in composite structures. Because of a lack of understanding of the consequences of delamination and the inability to predict delamination onset and growth, many composite parts are unnecessarily rejected upon inspection, both immediately after manufacture and while in service. NASA Langley is leading the efforts in the U.S. to develop a fatigue life prediction methodology for composite delamination using fracture mechanics. Research being performed to this end will be reviewed. Emphasis will be placed on the development of test standards for delamination characterization, incorporation of approaches for modeling delamination in commercial finite element codes, and efforts to mature the technology for use in design handbooks and certification documents.
Language:
English
Notes:
NATO RTO AVT-164 Workshop on Support of Composite Systems Bonn 19-22 Oct. 2009

39-06 SANDWICH CONSTRUCTION
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

39-07 STRESS ANALYSIS
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.

39-08 STRUCTURAL TESTS AND RELIABILITY
Nov 15, 2009 -- Additions to the NASA scientific and technical information knowledge base

No records are available for this topic on this date.