391
391
May 28, 2011
05/11
by
Skaggs, Patricia Annette; Nandula, Sastri P.; Pitz, Robert W
texts
eye 391
favorite 0
comment 0
This report documents work performed through the NASA Graduate Student Researchers Program, Grant No. NGT3-52316. Research performed included investigation of two-line fluorescence imaging of OH for temperature measurement and an investigation of negative flame speeds for modeling of premixed turbulent flames. The laboratory work and initial analysis of the fluorescence imaging was performed at NASA Glen Research Center with follow up analysis at Vanderbilt University. The negative flame speed...
Topics: STEADY FLOW, BAYS (STRUCTURAL UNITS), BLOWDOWN WIND TUNNELS, BLOWING, NOISE REDUCTION, JET AIRCRAFT...
Blowdown from Columbus Day storm that happened October 12, 1962. Cascade Head Experimental Forest, Otis, Oregon. Photo by: Wally C. Guy Date: October 25, 1962 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2741 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest insect...
Topics: october251962, otis, foresthealthprotection, ps2741, usda, columbusdaystorm,...
Heavy blowdown on edge of cutover near Fish Creek. Lane County, Oregon. Photo by: R.C. Wilson Date: May 23, 1952 Credit: National Archives and Records Administration RG# 95-GP. Records of the Forest Service. General Subject Files. US Forest Service Negative Number: 469872 NARA Image: 95-GP-1300-Box0306_021_001_AC For additional information see: Greeley, A.W., Wright, K.H. and Pope, R.B. 1953. Final report on the 1952 blowdown bark beetle survey in the Douglas-fir region of Oregon and...
Topics: usda, bureauofentomologyandplantquarantine, windthrow, wind, usda,...
Upturned root system of Douglas-fir windthrown by Columbus Day storm. Weyerhaeuser Company land, Toledo cutoff from Spirit Lake Highway, Washington. Photo by: Wally C. Guy Date: October 24, 1962 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2752 To learn more about this photo collection (as documented by Torgersen and Wickman) see: Wickman, B.E., Torgersen, T.R....
Topics: ps2752, spiritlakehighway, foresthealthprotection, usda, columbusdaystorm, stateandprivateforestry,...
Blowdown from the Columbus Day storm that happened on October 12, 1962. Cascade Head Experimental Forest, Otis, Oregon. Photo by: Wally C. Guy Date: October 25, 1962 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2737 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest...
Topics: windthrow, foresthealthprotection, usda, columbusdaystorm, stateandprivateforestry, oregon, otis,...
Heavy blowdown on the edge of cutting area near Fish Creek. Lane County, Oregon. Photo by: R.C. Wilson Date: May 23, 1952 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-948 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest insect investigations on the Pacific Slope,...
Topics: windthrow, insectdamage, foresthealthprotection, aerialphoto, usda, Aerial Detection Surveys,...
Blowdown from the Columbus Day storm that happened on October 12, 1962. Cascade Head Experimental Forest, Otis, Oregon. Photo by: Wally C. Guy Date: October 25, 1962 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2730 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest...
Topics: october251962, otis, foresthealthprotection, usda, columbusdaystorm, stateandprivateforestry, 1962...
The noise generated during the operation of large blowdown wind tunnels is considered. Noise calculation procedures are given to predict the test-section overall and spectrum level noise caused by both the tunnel burner and turbulent boundary layer. External tunnel noise levels due to the tunnel burner and circular jet exhaust flow are also calculated along with their respective cut-off frequency and spectrum peaks. The predicted values are compared with measured data, and the ability of the...
Topics: NASA Technical Reports Server (NTRS), ACOUSTIC MEASUREMENT, BLOWDOWN WIND TUNNELS, MATHEMATICAL...
Blowdown from the Columbus Day storm that happened on October 12, 1962. Cascade Head Experimental Forest, Otis, Oregon. Photo by: Wally C. Guy Date: October 25, 1962 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2736 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest...
Topics: october251962, otis, foresthealthprotection, usda, columbusdaystorm, stateandprivateforestry,...
211
211
May 22, 2011
05/11
by
Waters, L. B. F. M.; Kester, Do J. M.; Bontekoe, Tj. Romke; Loup, C
texts
eye 211
favorite 0
comment 0
We present high resolution HIRAS 60 and 100 micron images of AGB stars surrounded by fossil dust shells. Resolving the extended emission of the circumstellar dust allows a determination of the mass loss history of the star. We show that the geometry of the 60 micron emission surrounding HR 3126 agrees well with that of the optical reflection nebula. The emission around the carbon star U Hya is resolved into a central point source and a ring of dust, and the mass loss rate in the detached shell...
Topics: BLOWDOWN WIND TUNNELS, HEATERS, MACH NUMBER, HYPERSONIC WIND TUNNELS, PROPULSION, SUPERSONIC...
The Hypersonic Tunnel Facility (HTF) at NASA Lewis Research Center's Plum Brook Station is a blowdown, free-jet, nonvitiated propulsion facility capable of Mach 5, 6, and 7 with true temperature, altitude, and air composition simulation. The facility has been in a deactivated status for 13 years. Discussed are the capabilities of HTF, and the results of a deactivation study recently conducted to determine the cost, schedule, and technical effort required to restore HTF to its original design...
Topics: NASA Technical Reports Server (NTRS), ACTIVATION, HYPERSONIC SPEED, RESEARCH FACILITIES, TEST...
Blowdown from the Columbus Day storm that happened on October 12, 1962. Cascade Head Experimental Forest, Otis, Oregon. Photo by: Wally C. Guy Date: October 25, 1962 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2733 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest...
Topics: october251962, otis, windstorm, foresthealthprotection, usda, columbusdaystorm,...
Blowdown following the Columbus Day storm clogged many streams with debris, such as here on the Toutle River, Spirit Lake Highway, near Camp Baker, Washington. Photo by: Wally C. Guy Date: October 24, 1962 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2751 To learn more about this photo collection (as documented by Torgersen and Wickman) see: Wickman, B.E.,...
Topics: spiritlakehighway, usda, columbusdaystorm, stateandprivateforestry, windthrow, 1962 Columbus Day...
Heavy blowdown in an exposed seed block in Lincoln County, Oregon. Seed block is the lee side of low ridge to the right. Wind came from the southwest. Photo by: Carl Bernsten Date: August 19, 1952 Credit: National Archives and Records Administration RG# 95-GP. Records of the Forest Service. General Subject Files. US Forest Service Negative Number: 471407 NARA Image: 95-GP-1300-Box0306_019_001_AC For additional information see: Greeley, A.W., Wright, K.H. and Pope, R.B. 1953. Final report on the...
Topics: usda, bureauofentomologyandplantquarantine, seedblock, windthrow, wind, usda, blowdown,...
This report presents recent analyses, and fits of experimental data to scaled parameters, for blowdown pressures in vented chambers. Theoretical predictions are made for time histories of blowdown pressures, and a scaling law is presented. Limited comparisons are made with experiment.
Topics: DTIC Archive, Baker, W. E., Oldham, G. A., SOUTHWEST RESEARCH INST SAN ANTONIO TX, *STRUCTURES,...
G. Fagerness (left) and Leon Pettinger taking sample measurements on windthrown second-growth exposed Douglas-fir. McDonald Tree Farm, Washington. Photo by: Peter W. Orr Date: September 1959 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2305 For additional historic forest entomology photos, stories, and resources see the Western Forest Insect Work Conference site:...
Topics: usda, peterworr, stateandprivateforestry, windfall, gfagerness, washington, usfs, blowdown,...
Phellinus pini decay. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: c.2006 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, foresthealth, region6, kristenchadwick, c2006,...
Blowdown from Columbus Day storm that happened October 12, 1962. Cascade Head Experimental Forest, Otis, Oregon. Photo by: Wally C. Guy Date: October 25, 1962 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2743 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest insect...
Topics: usda, columbusdaystorm, stateandprivateforestry, windthrow, 1962 Columbus Day Storm, october251962,...
The effects on flutter of the aerodynamic interaction between the space shuttle bodies and wing, 1/80th-scale semispan models of the orbiter wing, the complete shuttle and intermediate component combinations were tested in the NASA Langley Research Center 26-inch Transonic Blowdown Wind Tunnel. Using the double lattice method combined with slender body theory to calculate unsteady aerodynamic forces, subsonic flutter speeds were computed for comparison. Using calculated complete vehicle modes,...
Topics: NASA Technical Reports Server (NTRS), AERODYNAMIC INTERFERENCE, BLOWDOWN WIND TUNNELS, SEMISPAN...
Trees killed by Douglas-fir beetle after blowdown event. Millicoma Forest (Weyerhaeuser Company). Coos County, Oregon. Photo by: P.G. Lauterbach and Ken H. Wright Date: August 1953 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2478 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history...
Topics: cooscounty, millicomaforest, usda, stateandprivateforestry, august1953, pglauterbach, tree,...
The Columbus Day windstorm of 1962 left many stands in this condition. When this photo was taken (11 months later), insects had not yet invaded the trees with roots partially attached. Cascade Head Experimental Forest. Otis, Oregon. Photo by: Ken H. Wright Date: September 1963 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2978 For additional historical forest...
Topics: usda, columbusdaystorm, stateandprivateforestry, 1962 Columbus Day Storm, wind,...
Blowdown in Douglas-fir-Hemlock timber type in Cape Creek. Siuslaw National Forest, Oregon. Photo by: Robert H. Ruth Date: November 24, 1952 RG# 95-GP. Records of the Forest Service. General Subject Files. US Forest Service Negative Number: 471474 NARA Image: 95-GP-1300-Box0306_015_001_AC For additional information see: Greeley, A.W., Wright, K.H. and Pope, R.B. 1953. Final report on the 1952 blowdown bark beetle survey in the Douglas-fir region of Oregon and Washington. USDA Forest Service,...
Topics: usda, bureauofentomologyandplantquarantine, hemlock, barkbeetle, coastrange, usda, blowdown,...
Cabin impacted by tree failure. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: March 17, 2003 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, 2003, foresthealth, region6, kristenchadwick,...
Lodgepole pine canker. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: August 4, 2006 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, lodgepolepine, foresthealth, 2006, region6,...
This report covers the measurement by the author of two of the fundamental blast parameters associated with explosions in air, i.e., dynamic pressure impulse (DPI), and blast pressure. The report illustrates how valuable a role inexpensive, passive instrumentation can play in measurement, especially in large scale field experiments. The gauges which form the subjects of this report were used most recently on the multi-national, large scale field event, MINOR UNCLE, which was a high explosive...
Topics: DTIC Archive, Howe, J. S., DEFENCE SCIENCE AND TECHNOLOGY ORGANIZATION CANBERRA (AUSTRALIA),...
A detailed description of the hypersonic CF4 tunnel is presented along with discussion of the basic components, instrumentation, and operating procedure. Operational experience with the CF4 reclaimer and lead-bath heater is discussed. Comparison of measured and predicted shock detachment distance on a sphere and pressure distributions measured on a sharp leading-edge flat plate revealed the absence of significant flow nonuniformity and lent creditability to predicted free stream flow...
Topics: NASA Technical Reports Server (NTRS), BLOWDOWN WIND TUNNELS, CALIBRATING, EQUIPMENT SPECIFICATIONS,...
The feasibility of employing thin-film heat-flux gages was studied as a method of defining boundary layer characteristics at supersonic speeds in a high speed blowdown wind tunnel. Flow visualization techniques (using oil) were employed. Tabulated data (computer printouts), a test facility description, and photographs of test equipment are given.
Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYER FLOW, HEAT MEASUREMENT, MEASURING INSTRUMENTS,...
Damage to dumpster caused by blowdown after hazard tree removal at Indian Henry Campground. Mt. Hood National Forest, Oregon. Photo by: Kristen Chadwick Date: July 21, 2011 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection:...
Topics: r6, usda, stateandprivateforestry, foresthealth, region6, mthoodnationalforest, kristenchadwick,...
Log deck of trees with decay. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: July 12, 2007 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: logdeck, r6, lakeofthewoods, usda, stateandprivateforestry, 2007, region6, kristenchadwick,...
Log deck of trees with decay. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: July 12, 2007 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: logdeck, r6, lakeofthewoods, usda, stateandprivateforestry, 2007, region6, kristenchadwick,...
Heavy blowdown in Douglas-fir on edge of cutover at head of San Antonio Creek. 65% of stand is windthrown. Lane County, Oregon. Photo by: R.C. Wilson Date: May 23, 1952 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-949 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest...
Topics: usda, bureauofentomologyandplantquarantine, windthrow, damagedetection, sanantoniocreek, fhp, wind,...
Partially failed roadside tree. Photo by: Kristen Chadwick Date: c.2006 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, foresthealth, region6, road, treefailure,...
Cabins impacted by falling trees. Camp Low Echo, Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: March 14, 2003 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, tree, 2003, foresthealth, region6, Buildings,...
This report describes methods for estimating shock pressures and vented gas pressures within suppressive structures and for estimated attenuated blast wave properties outside. Data are fitted to scaling laws, and prediction equations given with limits of validity. A computer code for predicting venting pressures is described.
Topics: DTIC Archive, Esparza, E. D., Baker, W. E., Oldham, G. A., SOUTHWEST RESEARCH INST SAN ANTONIO TX,...
Transfer of an existing continous circuit supersonic wind tunnel to Langley and its operation there as a blowdown tunnel is planned. Flow disturbance requirements in the supply section and methods for reducing the high level broad band acoustic disturbances present in typical blowdown tunnels are reviewed. Based on recent data and the analysis of two blowdown facilities at Langley, methods for reducing the total turbulence levels in the settling chamber, including both acoustic and vorticity...
Topics: NASA Technical Reports Server (NTRS), BLOWDOWN WIND TUNNELS, DAMPING, NOISE REDUCTION, STRUCTURAL...
Blowdown from the Columbus Day Storm that happened on October 12, 1962. Hebo Ranger District. Siuslaw National Forest, Oregon. Photo by: Wally C. Guy Date: October 24, 1962 Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Portland Station Collection; La Grande, Oregon. Image: PS-2749 To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of...
Topics: r6, usda, columbusdaystorm, stateandprivateforestry, ps2749, tree, 1962 Columbus Day Storm,...
Heavy blowdown associated with clear-cutting. The wind blew from the lower left to the upper right. Coast Range, Oregon. Photo by: Robert H. Ruth Date: November 24, 1952 Credit: National Archives and Records Administration RG# 95-GP.Records of the Forest Service .General Subject Files. US Forest Service Negative Number:471466 NARA Image: 95-GP-1300-Box0306_014_001_AC For additional information see: Greeley, A.W., Wright, K.H. and Pope, R.B. 1953. Final report on the 1952 blowdown bark beetle...
Topics: usda, bureauofentomologyandplantquarantine, salvage, survey, forest service, wind, barkbeetle,...
310
310
Jul 26, 2010
07/10
by
Moeckel, W. E
texts
eye 310
favorite 0
comment 0
No Abstract Available
Topics: ANNULAR FLOW, MACH NUMBER, NOZZLE FLOW, STAGNATION PRESSURE, VACUUM PUMPS, BLOWDOWN WIND TUNNELS,...
Cabin impacted by tree. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: March 17, 2003 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, tree, 2003, foresthealth, region6,...
Cabin with large tree failure in front of it. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: July 12, 2007 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, 2007, region6, treefailure, kristenchadwick,...
Blowdown from the October 12 Columbus Day Storm, near Seaside, Oregon. Photo by: Unknown Date: 1962 Credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection. Collection: Region 6, Forest Health Protection Slide Collection; Regional Office, Portland, Oregon. Image provided by USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, seaside, usda, columbusdaystorm, stateandprivateforestry, insectanddiseasecontrol, windthrow,...
Aerial view of area where 13% of stand is December 1951 windthrow. Douglas-fir and western hemlock. Taken on west-facing slope near Prairie Peak. Lane County, Oregon. Photo by: R.C. Wilson Date: May 23, 1952 Credit: National Archives and Records Administration RG# 95-GP. Records of the Forest Service. General Subject Files. US Forest Service Negative Number: 469868 NARA Image: 95-GP-1300-Box0306_022_001_AC For additional information see: Greeley, A.W., Wright, K.H. and Pope, R.B. 1953. Final...
Topics: usda, bureauofentomologyandplantquarantine, windthrow, wind, barkbeetle, prairiepeak, may231952,...
Presented is a description of the design construction and performance of the exhaust silencer for the NAL high Reynolds number two-dimensional transonic blow down wind tunnel, which was completed in October 1979. The silencer is a two-storied construction made of reinforced concrete, 40 m. long, 10 m. wide and 19 m. high and entirely enclosed by thick concrete walls. The upstream part of the first story, particularly, is covered with double walls, the thickness of the two walls being 0.3 m....
Topics: NASA Technical Reports Server (NTRS), BLOWDOWN WIND TUNNELS, COMPOSITE MATERIALS, CONCRETE...
An exploratory investigation was made of a wake disruption technique for studying the hypersonic-wake reestablishment time in a blowdown wind tunnel. In this technique, a highly underexpanded jet issuing from the base of a 10 deg half-angle cone totally disrupts and displaces the conventional wake. The jet was rapidly shut off by an explosively actuated valve and the time for wake reestablishment was measured. The tests were conducted in the Mach 6 high Reynolds number tunnel at a stagnation...
Topics: NASA Technical Reports Server (NTRS), HYPERSONIC FLOW, HYPERSONIC WAKES, TURBULENT WAKES, WIND...
Conversion of pulses of CO2 laser energy (18 microsecond pulses) to propellant kinetic energy was studied in a Myrabo Laser Lightcraft (MLL) operating with laser heated STP air and laser ablated delrin propellants. The MLL incorporates an inverted parabolic reflector that focuses laser energy into a toroidal volume where it is absorbed by a unit of propellant mass that is subsequently expanded in the geometry of the plug nozzle aerospike. With Delrin propellant, measurements of the coupling...
Topics: DTIC Archive, Larson, C W, AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST,...
Windfall associated with clearcutting in Lincoln County, Oregon. The area to the left of the cutting line had been high-graded for Douglas-fir. All but a few of the residual hemlock trees have blown down. Photo by: Carl Bernsten Date: August 19, 1952 Credit: National Archives and Records Administration RG# 95-GP. Records of the Forest Service. General Subject Files. US Forest Service Negative Number: 471408 NARA Image: 95-GP-1300-Box0306_018_001_AC For additional information see: Greeley, A.W.,...
Topics: usda, bureauofentomologyandplantquarantine, clearcutting, windfall, wind, barkbeetle, usda,...
Echinodontium tinctorium conks on white fir. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: August 4, 2006 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, conks, foresthealth, 2006, region6,...
White fir with rotten stump. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: August 14, 2006 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, foresthealth, 2006, region6, kristenchadwick,...
Analysis of energy conversion in laser propulsion is reported and compared to experimental studies of a laboratory scale propulsion device that absorbs laser energy and converts that energy to propellant kinetic energy. The propellants studied were air and Delrin, a solid with the composition of formaldehyde H2CO that vaporizes cleanly upon laser irradiation. The Myrabo Laser Lightcraft (MLL) was studied. It incorporates an inverted parabolic reflector that focuses laser energy into a toroidal...
Topics: DTIC Archive, Larson, C W, AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE WEST,...
Tree failure in snow. Lake of the Woods, Oregon. Photo by: Kristen Chadwick Date: December 16, 2002 Photo credit: USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection, Westside Forest Insect and Disease Service Center. Source: Kristen Chadwick collection; Sandy, Oregon. Image provided by USDA Forest Service, Region 6, State and Private Forestry, Forest Health Protection: www.fs.usda.gov/main/r6/forest-grasslandhealth
Topics: r6, lakeofthewoods, usda, stateandprivateforestry, 2002, foresthealth, region6, treefailure,...
