Young, Richard Arden
1972-01-01
The Nuclear Rocket Development Station, in Jackass Flats, occupies about 123 square miles in the southwestern part of the U.S. Atomic Energy Commission's Nevada Test Site. Jackass Flats, an intermontane valley bordered by highlands on all sides except for a drainage outlet in the southwestern corner, has an average annual rainfall of 4 inches. Jackass Flats is underlain by alluvium, colluvium, and volcanic rocks of Cenozoic age and, at greater depth, by sedimentary rocks of Paleozoic age. The alluvium and the colluvium lie above the saturated zone throughout nearly all of Jackass Flats. The Paleozoic sedimentary rocks contain limestone and dolomite units that are excellent water producers elsewhere ; however, these units are too deep in Jackass Flats to be economic sources of water. The only important water-producing unit known in the vicinity of the Nuclear Rocket Development Station is a welded-tuff aquifer, the Topopah Spring Member of the Paintbrush Tuff, which receives no significant recharge. This member contains about 500 feet of highly fractured rock underlying an area 11 miles long and 3 miles wide in western Jackass Flats. Permeability of the aquifer is derived mostly from joints and fractures; however, some permeability may be derived from gas bubbles in the upper part of the unit. Transmissivity, obtained from pumping tests, ranges from 68,000 to 488,000 gallons per day per foot. Volume of the saturated part of the aquifer is about 3.5 cubic miles, and the average specific yield probably ranges from 1 to 5 percent. The volume of ground water in storage is probably within the range of 37-187 billion gallons. This large amount of water should be sufficient to supply the needs of the Nuclear Rocket Development Station for many years. Water at the Nuclear Rocket Development Station is used for public supply, construction, test-cell coolant, exhaust cooling, and thermal shielding during nuclear reactor and engine testing, and washdown. Present (1967) average consumption of water is 520,000 gallons per day--all supplied by one well. This supply well and a standby well have a production capability of 1.6 million gallons per day--adequate for present needs. Water in the welded-tuff aquifer is of the sodium bicarbonate type. Dissolved-solids content of the water in Jackass Flats is in the general range 230 milligrams per liter in the western part to 890 milligrams per liter in the eastern part.
La Camera, Richard J.; Locke, Glenn L.; Habte, Aron M.; Darnell, Jon G.
2006-01-01
The U.S. Geological Survey, in support of the U.S. Department of Energy, Office of Repository Development, collects, compiles, and summarizes hydrologic data in the Yucca Mountain region of southern Nevada and eastern California. These data are collected to allow assessments of ground-water resources during activities to determine the potential suitability or development of Yucca Mountain for storing high-level nuclear waste. Data on ground-water levels at 35 boreholes and 1 fissure (Devils Hole), ground-water discharge at 5 springs, both ground-water levels and discharge at 1 flowing borehole, and total reported ground-water withdrawals within Crater Flat, Jackass Flats, Mercury Valley, and the Amargosa Desert are tabulated from January through December 2004. Also tabulated are ground-water levels, discharges, and withdrawals collected by other agencies (or collected as part of other programs) and data revised from those previously published at monitoring sites. Historical data on water levels, discharges, and withdrawals are presented graphically to indicate variations through time. A statistical summary of ground-water levels at seven boreholes in Jackass Flats is presented for the period 1992-2004 to indicate potential effects of ground-water withdrawals associated with U.S. Department of Energy activities near Yucca Mountain. The statistical summary includes the annual number of measurements, maximum, minimum, and median water-level altitudes, and average deviation of measured water-level altitudes compared to the 1992-93 baseline period. At six boreholes in Jackass Flats, median water levels for 2004 were slightly higher (0.3-2.7 feet) than their median water levels for 1992-93. At one borehole in Jackass Flats, median water level for 2004 equaled the median water level for 1992-93.
Locke, Glenn L.
2008-01-01
The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, Office of Civilian Radioactive Waste Management, collected, compiled, and summarized hydrologic data in the Yucca Mountain region of southern Nevada and eastern California. These data were collected to allow assessments of ground-water resources during activities to determine the potential suitability or development of Yucca Mountain for storing high-level nuclear waste. Data collected from January through December 2005 are provided for ground-water levels at 35 boreholes and 1 fissure (Devils Hole), ground-water discharge at 5 springs, ground-water levels and discharge at 1 flowing borehole, and total reported ground-water withdrawals within Crater Flat, Jackass Flats, Mercury Valley, and the Amargosa Desert. Ground-water level, discharge, and withdrawal data collected by other agencies, or as part of other programs, are provided. A statistical summary of ground-water levels at seven boreholes in Jackass Flats is presented for 1992-2005 to indicate potential effects of ground-water withdrawals associated with U.S. Department of Energy activities near Yucca Mountain. The statistical summary includes the annual number of measurements; maximum, minimum, and median water-level altitudes; and average deviation of measured water-level altitudes compared to the 1992-93 baseline period. At seven boreholes in Jackass Flats, median water levels for 2005 were slightly higher (0.4-2.7 feet) than the median water levels for 1992-93.
Locke, Glenn L.; La Camera, Richard J.
2003-01-01
The U.S. Geological Survey, in support of the U.S. Department of Energy, Yucca Mountain Project, collects, compiles, and summarizes hydrologic data in the Yucca Mountain region. The data are collected to allow assessments of ground-water resources during activities to determine the potential suitability or development of Yucca Mountain for storing high-level nuclear waste. Data on ground-water levels at 35 wells and a fissure (Devils Hole), ground-water discharge at 5 springs and a flowing well, and total reported ground-water withdrawals within Crater Flat, Jackass Flats, Mercury Valley, and the Amargosa Desert are tabulated from January 2000 through December 2002. Historical data on water levels, discharges, and withdrawals are graphically presented to indicate variations through time. A statistical summary of ground-water levels at seven wells in Jackass Flats is presented for 1992-2002 to indicate potential effects of ground-water withdrawals associated with U.S. Department of Energy activities near Yucca Mountain. The statistical summary includes the annual number of measurements, maximum, minimum, and median water-level altitudes, and average deviation of measured water-level altitudes compared to selected baseline periods. Baseline periods varied for 1985-93. At six of the seven wells in Jackass Flats, the median water levels for 2002 were slightly higher (0.3-2.4 feet) than for their respective baseline periods. At the remaining well, data for 2002 was not summarized statistically but median water-level altitude in 2001 was 0.7 foot higher than that in its baseline period.
Locke, Glenn L.
2001-01-01
The U.S. Geological Survey, in support of the U.S. Department of Energy, Yucca Mountain Site Characterization Project, collects, compiles, and summarizes hydrologic data in the Yucca Mountain region. The data are collected to allow assessments of ground-water resources during studies to determine the potential suitability of Yucca Mountain for storing high-level nuclear waste. Data on ground-water levels at 34 wells and a fissure (Devils Hole), ground-water discharge at 5 springs and a flowing well, and total reported ground-water withdrawals within Crater Flat, Jackass Flats, Mercury Valley, and the Amargosa Desert are presented for calendar year 1998. Data collected prior to 1998 are graphically presented and data collected by other agencies (or as part of other Geolgical Survey programs) are included to further indicate variations of ground-water levels, discharges, and withdrawals through time. A statistical summary of ground-water levels at seven wells in Jackass Flats is presented to indicate potential effects of ground-water withdrawals associated with U.S. Department of Energy activities near Yucca Mountain. The statistical summary includes the number of measurements, the maximum, minimum, and median water-level altitudes, and the average deviation of measured water-level altitudes for selected baseline periods and for calendar years 1992-98. At two water-supply wells and a nearby observation well, median water levels for calendar year 1998 were slightly lower (0.2 to 0.3 foot) than for their respective baseline periods. At the remaining four wells in Jackass Flats, median water levels for 1998 were unchanged at two wells and slightly higher (0.4 and 1.4 foot) at two wells than those for their respective baseline periods.
Locke, G.L.
2001-01-01
The U.S. Geological Survey, in support of the U.S. Department of Energy, Yucca Mountain Site Characterization Project, collects, compiles, and summarizes hydrologic data in the Yucca Mountain region. The data are collected to allow assessments of ground-water resources during studies to determine the potential suitability of Yucca Mountain for storing high-level nuclear waste. Data on ground-water levels at 34 wells and a fissure (Devils Hole), ground-water discharge at 5 springs and a flowing well, and total reported ground-water withdrawals within Crater Flat, Jackass Flats, Mercury Valley, and the Amargosa Desert are presented for calendar year 1999. Data collected prior to 1999 are graphically presented and data collected by other agencies (or as part of other Geological Survey programs) are included to further indicate variations of ground-water levels, discharges, and withdrawals through time. A statistical summary of ground-water levels at seven wells in Jackass Flats is presented to indicate potential effects of ground-water withdrawals associated with U.S. Department of Energy activities near Yucca Mountain. The statistical summary includes the number of measurements, the maximum, minimum, and median water-level altitudes, and the average deviation of measured water-level altitudes for selected baseline periods and for calendar years 1992-99. At two water-supply wells median water levels for calendar year 1999 were unchanged from their respective baseline periods. At a nearby observation well, the 1999 median water level was slightly lower (0.1 foot) than its baseline period. At the remaining four wells in Jackass Flats, median water levels for 1999 were slightly higher (0.2 foot to 1.6 feet) than for their respective baseline periods.
Westenburg, C.L.; La Camera, R. J.
1996-01-01
The U.S. Geological Survey, in support of the U.S. Department of Energy, Yucca Mountain Site Characterization Project, collects, compiles, and summarizes hydrologic data in the Yucca Mountain region. The data are collected to allow assessments of ground-water resources during studies to determine the potential suitability of Yucca Mountain for storing high-level nuclear waste. Data on ground-water levels at 36 sites, ground-water discharge at 6 sites, and ground-water withdrawals within Crater Flat, Jackass Flats, Mercury Valley, and the Amargosa Desert are presented for calendar year 1994. Data collected prior to 1994 are graphically presented and data collected by other agencies (or as part of other programs) are included to further indicate variations of ground-water levels, discharges, and withdrawals through time. A statistical summary of ground-water levels at seven wells in Jackass Flats is presented. The statistical summary includes the number of measurements, the maximum, minimum, and median water-level altitudes, and the average deviation of measured water-level altitudes for selected baseline periods and for calendar years 1992-94.
10. VIEW WITHIN THE EAST OPERATING GALLERY OF WORK STATION ...
10. VIEW WITHIN THE EAST OPERATING GALLERY OF WORK STATION WITH MANIPULATOR ARMS. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
14. VIEW IN THE WEST OPERATING GALLERY OF POSTMORTEM CELL ...
14. VIEW IN THE WEST OPERATING GALLERY OF POST-MORTEM CELL WORK STATION AND MANIPULATOR ARMS. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
7. EXTERIOR VIEW TO THE SOUTHWEST OF THE NORTH AND ...
7. EXTERIOR VIEW TO THE SOUTHWEST OF THE NORTH AND EAST ELEVATIONS. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
9. EXTERIOR VIEW TO THE NORTHWEST OF THE SOUTH AND ...
9. EXTERIOR VIEW TO THE NORTHWEST OF THE SOUTH AND EAST ELEVATIONS. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
16. VIEW OF FIRST FLOOR EAST OPERATING GALLERY. NOTE THE ...
16. VIEW OF FIRST FLOOR EAST OPERATING GALLERY. NOTE THE SERIES OF MANIPULATOR ARMS ALONG THE LEFT WALL. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
1. GENERAL VIEW TO THE WEST OF THE EMAD FACILITY ...
1. GENERAL VIEW TO THE WEST OF THE E-MAD FACILITY AND THE SURROUNDING ENVIRONMENTAL AND TOPOGRAPHICAL SETTING. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
7. VIEW OF E5 WORK STATION AND MANIPULATOR ARMS WITHIN ...
7. VIEW OF E-5 WORK STATION AND MANIPULATOR ARMS WITHIN THE SOUTHEAST CORNER OF THE HOT BAY. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
14. INTERIOR VIEW TO THE SOUTH OF ROOM 136, COLD ...
14. INTERIOR VIEW TO THE SOUTH OF ROOM 136, COLD ASSEMBLY BAY NO. 2. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
13. INTERIOR VIEW TO THE SOUTHEAST OF ROOM 101, COLD ...
13. INTERIOR VIEW TO THE SOUTHEAST OF ROOM 101, COLD ASSEMBLY BAY NO. 1. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
10. INTERIOR VIEW TO THE SOUTHEAST OF INSTRUMENTS AND EQUIPMENT ...
10. INTERIOR VIEW TO THE SOUTHEAST OF INSTRUMENTS AND EQUIPMENT IN ROOM 1. - Nevada Test Site, Test Cell A Facility, Test Cell A Building & Addition, Area 25, Jackass Flats, Road F, Mercury, Nye County, NV
11. INTERIOR VIEW TO THE SOUTH OF INSTRUMENTS AND EQUIPMENT ...
11. INTERIOR VIEW TO THE SOUTH OF INSTRUMENTS AND EQUIPMENT IN ROOM 1. - Nevada Test Site, Test Cell A Facility, Test Cell A Building & Addition, Area 25, Jackass Flats, Road F, Mercury, Nye County, NV
8. EXTERIOR VIEW TO THE WEST OF THE EAST ELEVATION ...
8. EXTERIOR VIEW TO THE WEST OF THE EAST ELEVATION OF THE HOT DISASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
2. EXTERIOR VIEW TO THE NORTH OF THE SOUTH ELEVATION ...
2. EXTERIOR VIEW TO THE NORTH OF THE SOUTH ELEVATION OF THE HOT DISASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
8. VIEW OF E3 WORK STATION WITH MANIPULATOR ARMS IN ...
8. VIEW OF E-3 WORK STATION WITH MANIPULATOR ARMS IN EAST OPERATING GALLERY LOOKING INTO THE HOT BAY. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
4. EXTERIOR VIEW TO THE EAST OF THE WEST ELEVATION ...
4. EXTERIOR VIEW TO THE EAST OF THE WEST ELEVATION OF THE COLD ASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
22. INTERIOR VIEW TO THE SOUTHWEST OF THE LOWER LEVEL ...
22. INTERIOR VIEW TO THE SOUTHWEST OF THE LOWER LEVEL OF ROOM 123, THE DISASSEMBLY BAY. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
21. INTERIOR VIEW TO THE SOUTHEAST OF THE LOWER LEVEL ...
21. INTERIOR VIEW TO THE SOUTHEAST OF THE LOWER LEVEL OF ROOM 123, THE DISASSEMBLY BAY. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
6. EXTERIOR VIEW TO THE SOUTH OF THE NORTH ELEVATION ...
6. EXTERIOR VIEW TO THE SOUTH OF THE NORTH ELEVATION OF THE HOT DISASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
5. VIEW TO THE SOUTHEAST OF THE HOT BAY AND ...
5. VIEW TO THE SOUTHEAST OF THE HOT BAY AND ATTACHED OPERATING GALLERIES ALONG THE WEST SIDE OF THE BAY. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
23. INTERIOR VIEW TO THE SOUTHEAST OF THE UPPER SECTION ...
23. INTERIOR VIEW TO THE SOUTHEAST OF THE UPPER SECTION OF ROOM 123, THE DISASSEMBLY BAY. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
24. INTERIOR VIEW TO THE SOUTHWEST OF THE UPPER SECTION ...
24. INTERIOR VIEW TO THE SOUTHWEST OF THE UPPER SECTION OF ROOM 123, THE DISASSEMBLY BAY. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
37. INTERIOR VIEW TO THE WEST OF ROOM 203, THE ...
37. INTERIOR VIEW TO THE WEST OF ROOM 203, THE CONTROL ROOM FOR THE DISASSEMBLY BAY. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
13. INTERIOR VIEW TO THE WEST OF EQUIPMENT IN ROOM ...
13. INTERIOR VIEW TO THE WEST OF EQUIPMENT IN ROOM 2, RADIATION EFFECTS ROOM. - Nevada Test Site, Test Cell A Facility, Test Cell A Building & Addition, Area 25, Jackass Flats, Road F, Mercury, Nye County, NV
3. EXTERIOR VIEW TO THE SOUTHEAST OF THE NORTH AND ...
3. EXTERIOR VIEW TO THE SOUTHEAST OF THE NORTH AND WEST ELEVATIONS OF THE TEST CELL. - Nevada Test Site, Test Cell C Facility, Building No. 3210, Area 25, Jackass Flats, Road J, Mercury, Nye County, NV
26. INTERIOR VIEW TO THE SOUTH OF ROOM 148, A ...
26. INTERIOR VIEW TO THE SOUTH OF ROOM 148, A POST-MORTEM CELL IN THE HOT DISASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
29. INTERIOR VIEW TO THE EAST OF ROOM 144, A ...
29. INTERIOR VIEW TO THE EAST OF ROOM 144, A POST-MORTEM CELL IN THE HOT DISASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
10. INTERIOR VIEW TO THE NORTH OF THE HALLWAY WITHIN ...
10. INTERIOR VIEW TO THE NORTH OF THE HALLWAY WITHIN THE ADMINISTRATION PORTION OF THE COLD ASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
15. INTERIOR VIEW TO THE EAST OF ROOM 102, A ...
15. INTERIOR VIEW TO THE EAST OF ROOM 102, A MACHINE SHOP ADJACENT TO ASSEMBLY BAY NO. 1. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
6. EXTERIOR VIEW TO THE NORTHWEST OF THE SOUTHEAST CORNER ...
6. EXTERIOR VIEW TO THE NORTHWEST OF THE SOUTHEAST CORNER OF THE EAST ELEVATION OF THE TEST CELL. - Nevada Test Site, Test Cell C Facility, Building No. 3210, Area 25, Jackass Flats, Road J, Mercury, Nye County, NV
5. EXTERIOR VIEW TO THE WEST OF THE EAST ELEVATION ...
5. EXTERIOR VIEW TO THE WEST OF THE EAST ELEVATION OF THE TEST CELL, WITH DEWARS IN THE BACKGROUND. - Nevada Test Site, Test Cell C Facility, Building No. 3210, Area 25, Jackass Flats, Road J, Mercury, Nye County, NV
4. EXTERIOR VIEW TO THE NORTH OF THE WESTERN PORTION ...
4. EXTERIOR VIEW TO THE NORTH OF THE WESTERN PORTION OF THE SOUTH ELEVATION OF THE TEST CELL. - Nevada Test Site, Test Cell C Facility, Building No. 3210, Area 25, Jackass Flats, Road J, Mercury, Nye County, NV
13. VIEW OF EAST OPERATING GALLERY ALONG THE POSTMORTEM CELLS. ...
13. VIEW OF EAST OPERATING GALLERY ALONG THE POST-MORTEM CELLS. A NUMBER OF MANIPULATOR ARMS COVERED WITH PLASTIC ARE ON THE LEFT WALL. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
28. INTERIOR VIEW TO THE SOUTHEAST OF ROOMS 133 AND ...
28. INTERIOR VIEW TO THE SOUTHEAST OF ROOMS 133 AND 134, POST-MORTEM CELLS IN THE HOT DISASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
16. INTERIOR VIEW TO THE SOUTHEAST OF ROOM 137, A ...
16. INTERIOR VIEW TO THE SOUTHEAST OF ROOM 137, A REACTOR CONTROL LAB ADJACENT TO ASSEMBLY BAY NO. 2. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
19. VIEW TO THE NORTH FROM THE EXTERIOR INTO THE ...
19. VIEW TO THE NORTH FROM THE EXTERIOR INTO THE INTERIOR OF ROOM 105, THE BOILER ROOM FOR THE BUILDING. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
20. INTERIOR VIEW TO THE EAST OF THE ACCESS RAMP ...
20. INTERIOR VIEW TO THE EAST OF THE ACCESS RAMP TO THE HOT DISASSEMBLY AREA FROM THE COLD ASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
18. INTERIOR VIEW TO THE WEST OF ROOM 141, THE ...
18. INTERIOR VIEW TO THE WEST OF ROOM 141, THE HVAC EQUIPMENT ROOM FOR COOLING AND HEATING OF THE BUILDING. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
11. INTERIOR VIEW TO THE NORTHEAST OF ROOM 160, AN ...
11. INTERIOR VIEW TO THE NORTHEAST OF ROOM 160, AN OFFICE BY THE MAIN ENTRANCE DOOR OF THE ADMINISTRATION AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
15. INTERIOR VIEW TO THE NORTHEAST OF EQUIPMENT IN ROOM ...
15. INTERIOR VIEW TO THE NORTHEAST OF EQUIPMENT IN ROOM 4, EQUIPMENT AND GENERATOR ROOM, BUILDING 3113/3113A. - Nevada Test Site, Test Cell A Facility, Test Cell A Building & Addition, Area 25, Jackass Flats, Road F, Mercury, Nye County, NV
14. INTERIOR VIEW TO THE EAST OF EQUIPMENT IN ROOM ...
14. INTERIOR VIEW TO THE EAST OF EQUIPMENT IN ROOM 3, FLOW CONTROL ROOM, BUILDING 3113/3113A. - Nevada Test Site, Test Cell A Facility, Test Cell A Building & Addition, Area 25, Jackass Flats, Road F, Mercury, Nye County, NV
2. EXTERIOR VIEW TO THE SOUTH OF THE PIPING ON ...
2. EXTERIOR VIEW TO THE SOUTH OF THE PIPING ON THE ROOF OF AND NEXT TO THE BUILDING. - Nevada Test Site, Test Cell A Facility, Test Cell A Building & Addition, Area 25, Jackass Flats, Road F, Mercury, Nye County, NV
25. INTERIOR VIEW TO THE NORTH OF ROOM 149, THE ...
25. INTERIOR VIEW TO THE NORTH OF ROOM 149, THE ENTRANCE HALLWAY TO THE POST-MORTEM CELLS IN THE HOT DISASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
2. VIEW TO THE SOUTHWEST OF THE MAIN EMAD BUILDING ...
2. VIEW TO THE SOUTHWEST OF THE MAIN E-MAD BUILDING WITH THE COLD BAY ON THE EAST (LEFT) AND THE HOT BAY ON THE WEST (RIGHT). - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
17. INTERIOR VIEW TO THE EAST OF ROOM 215, A ...
17. INTERIOR VIEW TO THE EAST OF ROOM 215, A SECOND FLOOR OFFICE ABOVE ROOM 137 IN THE COLD ASSEMBLY AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
39. INTERIOR VIEW TO THE NORTH OF A WORK STATION ...
39. INTERIOR VIEW TO THE NORTH OF A WORK STATION WITH MANIPULATOR ARMS IN THE SOUTH CORRIDOR OF THE SECOND FLOOR. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
30. INTERIOR VIEW TO THE NORTH OF THE WEST CORRIDOR ...
30. INTERIOR VIEW TO THE NORTH OF THE WEST CORRIDOR OF THE BASEMENT IN THE HOT DISASSEMBLY AREA. ELECTRIC MOTORS LINE THE WEST WALL. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
4. VIEW TO THE NORTHWEST OF THE COLD BAY ON ...
4. VIEW TO THE NORTHWEST OF THE COLD BAY ON THE NORTH (RIGHT) AND THE POST-MORTEM CELLS ON THE SOUTH (LEFT). ALSO ILLUSTRATED ARE THE DIFFERENT ROOF HEIGHTS OF THE BUILDING. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
5. EXTERIOR VIEW TO THE SOUTHEAST OF THE NORTH AND ...
5. EXTERIOR VIEW TO THE SOUTHEAST OF THE NORTH AND WEST ELEVATIONS, WITH THE COLD ASSEMBLY AREA TO THE RIGHT AND THE HOT DISASSEMBLY AREA TO THE LEFT. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
12. INTERIOR VIEW TO THE NORTH OF THE RESTROOM AND ...
12. INTERIOR VIEW TO THE NORTH OF THE RESTROOM AND UTILITY ROOM AT THE NORTH END OF THE MAIN ENTRANCE HALLWAY OF THE ADMINISTRATION AREA. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
3. EXTERIOR VIEW TO THE NORTH OF THE SOUTH ELEVATION ...
3. EXTERIOR VIEW TO THE NORTH OF THE SOUTH ELEVATION OF THE ADMINISTRATION AREA IN THE COLD ASSEMBLY AREA, WITH THE MAIN ENTRANCE 'KENNEDY DOORS' IN THE MIDDLE. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
3. NORTH ELEVATION OF THE HOT BAY, SHOWING RAILROAD TRACKS ...
3. NORTH ELEVATION OF THE HOT BAY, SHOWING RAILROAD TRACKS LEADING TO THE MASSIVE STEEL-LINED CONCRETE ENTRANCE DOOR. PART OF THE INTRICATE HVAC SYSTEM IS WEST (RIGHT) OF THE DOOR. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
31. INTERIOR VIEW TO THE EAST OF THE FIRST FLOOR ...
31. INTERIOR VIEW TO THE EAST OF THE FIRST FLOOR SOUTH CORRIDOR AND VIEWING GALLERY TO THE DISASSEMBLY BAY AND POST-MORTEM CELLS. VIEWING STATIONS ARE ON BOTH SIDES OF THE CORRIDOR. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
33. INTERIOR VIEW TO THE SOUTHWEST OF ROOM 135, A ...
33. INTERIOR VIEW TO THE SOUTHWEST OF ROOM 135, A FIRST FLOOR CORRIDOR AND VIEWING GALLERY NEXT TO THE POST-MORTEM CELLS. VIEWING AND WORK STATIONS ARE ON THE WEST WALL. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
38. INTERIOR VIEW TO THE NORTHWEST OF THE SECOND FLOOR ...
38. INTERIOR VIEW TO THE NORTHWEST OF THE SECOND FLOOR CORRIDOR ON THE SOUTH SIDE OF THE DISASSEMBLY BAY. VIEWING AND WORK STATIONS ARE ALONG THE NORTH WALL OF THE CORRIDOR. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
1. EXTERIOR VIEW TO THE NORTH OF THE SOUTH ELEVATIONS ...
1. EXTERIOR VIEW TO THE NORTH OF THE SOUTH ELEVATIONS OF THE R-MAD FACILITY WITH THE COLD ASSEMBLY AREA ON THE LEFT AND THE HOT DISASSEMBLY AREA TO THE RIGHT. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
6. INTERIOR VIEW TO THE EAST OF SOUTHEAST CORNER OF ...
6. INTERIOR VIEW TO THE EAST OF SOUTHEAST CORNER OF THE HOT BAY. A LARGE MANIPULATOR ARM AND HORIZONTAL TRACKING SYSTEM IS SHOWN ABOVE SMALLER MANIPULATOR ARM WORK STATIONS. ASSOCIATED WITH THE WORK STATIONS ARE OBSERVATION WINDOWS. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
35. INTERIOR VIEW TO THE NORTHWEST OF ROOM 152, A ...
35. INTERIOR VIEW TO THE NORTHWEST OF ROOM 152, A FIRST FLOOR CORRIDOR AND VIEWING GALLERY ON THE WEST SIDE OF THE POST-MORTEM CELLS. VIEWING AND WORK STATIONS ARE IN THE EAST WALL. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
17. Photocopy of photograph. VIEW OF WORKERS IN EAST OPERATING ...
17. Photocopy of photograph. VIEW OF WORKERS IN EAST OPERATING GALLERY USING MANIPULATOR ARMS AT STATION E-108. Photographer unknown, ca. 1965, original photograph and negative on file at the Remote Sensing Laboratory, Department of Energy, Nevada Operations Office. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
34. INTERIOR VIEW TO THE NORTH OF ROOMS 143 AND ...
34. INTERIOR VIEW TO THE NORTH OF ROOMS 143 AND 150, A FIRST FLOOR CORRIDOR AND VIEWING GALLERY ON THE EAST SIDE OF THE POST-MORTEM CELLS. VIEWING AND WORK STATIONS ARE IN THE NORTH AND WEST WALLS. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
18. Photocopy of photograph. VIEW WITHIN POSTMORTEM CELL OF MANIPULATOR ...
18. Photocopy of photograph. VIEW WITHIN POST-MORTEM CELL OF MANIPULATOR ARMS BEING USED TO MOVE METAL BARS FROM ONE LOCATION TO ANOTHER. Photographer unknown, ca. 1965, original photograph and negative on file at the Remote Sensing Laboratory, Department of Energy, Nevada Operations Office. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
19. Photocopy of photograph. VIEW OF WORKER MANIPULATING SMALL GLASS ...
19. Photocopy of photograph. VIEW OF WORKER MANIPULATING SMALL GLASS OBJECTS IN THE HOT BAY WITH MANIPULATOR ARMS AT WORK STATION E-2. Photographer unknown, ca. 1969, original photograph and negative on file at the Remote Sensing Laboratory, Department of Energy, Nevada Operations Office. - Nevada Test Site, Engine Maintenance Assembly & Disassembly Facility, Area 25, Jackass Flats, Mercury, Nye County, NV
36. INTERIOR VIEW TO THE NORTHWEST OF THE SECOND FLOOR ...
36. INTERIOR VIEW TO THE NORTHWEST OF THE SECOND FLOOR CORRIDOR ON THE EAST SIDE OF THE DISASSEMBLY BAY. A VIEWING AND WORK STATION AND ENTRANCE TO THE CONTROL ROOM ARE ON THE WEST SIDE OF THE CORRIDOR. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
32. INTERIOR VIEW TO THE NORTH OF THE FIRST FLOOR ...
32. INTERIOR VIEW TO THE NORTH OF THE FIRST FLOOR EAST CORRIDOR AND VIEWING GALLERY TO THE DISASSEMBLY BAY. A VIEWING AND WORK STATION FOR THE EAST SIDE OF THE UPPER LEVEL OF THE DISASSEMBLY BAY IS ON THE WEST SIDE OF THE CORRIDOR. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
Nuclear Propulsion in Space (1968)
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
Project NERVA was an acronym for Nuclear Engine for Rocket Vehicle Application, a joint program of the U.S. Atomic Energy Commission and NASA managed by the Space Nuclear Propulsion Office (SNPO) at the Nuclear Rocket Development Station in Jackass Flats, Nevada U.S.A. Between 1959 and 1972, the Space Nuclear Propulsion Office oversaw 23 reactor tests, both the program and the office ended at the end of 1972.
Nuclear Propulsion in Space (1968)
None
2018-01-16
Project NERVA was an acronym for Nuclear Engine for Rocket Vehicle Application, a joint program of the U.S. Atomic Energy Commission and NASA managed by the Space Nuclear Propulsion Office (SNPO) at the Nuclear Rocket Development Station in Jackass Flats, Nevada U.S.A. Between 1959 and 1972, the Space Nuclear Propulsion Office oversaw 23 reactor tests, both the program and the office ended at the end of 1972.
40. INTERIOR VIEW TO THE SOUTHEAST OF ROOM 302, A ...
40. INTERIOR VIEW TO THE SOUTHEAST OF ROOM 302, A SMALL ISOLATED OFFICE ON THE THIRD FLOOR ON THE EAST SIDE OF THE DISASSEMBLY BAY. A METAL SPIRAL STAIRCASE IS IN THE SOUTHEAST CORNER AND HATCHWAYS ARE IN THE CEILING AND FLOOR TOWARD THE EAST SIDE OF THE ROOM. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
27. INTERIOR VIEW TO THE WEST OF ROOM 126 AT ...
27. INTERIOR VIEW TO THE WEST OF ROOM 126 AT THE NORTH END OF THE ENTRANCE HALLWAY TO THE POST-MORTEM CELLS. IN THE CEILING IS A HATCHWAY TO THE UPPER LEVEL OF ROOM 123, THE DISASSEMBLY BAY, BY WHICH PARTS OF THE NUCLEAR REACTOR WERE PASSED FOR FURTHER DISASSEMBLY IN THE VARIOUS POST-MORTEM CELLS. - Nevada Test Site, Reactor Maintenance Assembly & Dissassembly Facility, Area 25, Jackass Flats, Junction of Roads F & G, Mercury, Nye County, NV
La Camera, Richard J.; Westenburg, Craig L.
1994-01-01
Tne U.S. Geological Survey. in support of the U.S. Department of Energy, Yucca Mountain Site- Characterization Project, collects, compiles, and summarizes water-resource data in the Yucca Mountain region. The data are collected to document the historical and current condition of ground-water resources, to detect and document changes in those resources through time, and to allow assessments of ground-water resources during investigations to determine the potential suitability of Yucca Mountain for storing high-level nuclear waste. Data on ground-water levels at 36 sites, ground- water discharge at 6 sites, ground-water quality at 19 sites, and ground-water withdrawals within Crater Fiat, Jackass Flats, Mercury Valley, and the Amargosa Desert are presented. Data on ground-water levels, discharges, and withdrawals collected by other agencies or as part of other programs are included to further indicate variations through time. A statistical summary of ground-water levels and median annual ground-water withdrawals in Jackass Flats is presented. The statistical summary includes the number of measurements, the maximum, minimum, and median water-level altitudes, and the average deviation of a11 water-level altitudes for selected baseline periods and for calendar year 1992. Data on ground-water quality are compared to established, proposed, or tentative primary and secondary drinking-water standards, and measures which exceeded those standards are listed for 18 sites. Detected organic compounds for which established, proposed, or tentative drinking-water standards exist also are listed.
Status of the flora and fauna on the Nevada Test Site, 1989--1991
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hunter, R.B.
1994-03-01
This volume includes six reports of monitoring work to determine the status of and trends in flora and fauna populations on the Nevada Test Site (NTS) from 1989 through 1991. The Nevada Operations Office of the US Department of Energy supported monitoring under its Basic Environmental Compliance and Monitoring Program (BECAMP) since 1987. Under this program several undisturbed baseline plots, and numerous plots in disturbed areas, are sampled on annual or three-year cycles. Perennial plant populations, ephemeral plants, small mammals, reptiles, birds, and large mammals were monitored. Monitoring results are reported for five baseline sites, one from each major landformmore » on the NTS (Jackass Flats, Frenchman Flat, Yucca Flat, Pahute Mesa, and Rainier Mesa), and for areas cleared of vegetation by fires, atmospheric nuclear weapons tests, construction, and gophers. Roadside flora and fauna were studied at two locations, and several historical study plots around the NTS were recensused to determine vegetation changes over long time spans. Three subsidence craters resulting from below-ground nuclear weapons tests were also studied. A major influence on plants and animals during the report period was a severe drought during 1989 and 1990, followed by more moderate drought in 1991.« less
NASA Technical Reports Server (NTRS)
Accinelli, J. B.; Koch, D. A.; Reuter, F.
1972-01-01
The use of liquid hydrogen to cool the rolling element radial bearings in the nuclear engine for rocket vehicles is discussed. The fifteen hour service life goal was obtained during the tests. The increase in bearing life was also considered to be produced by: (1) improvements in bearing material, (2) bearing retainer configuration and manufacturing changes, and (3) better control of operating parameters.
A seismic study of Yucca Mountain and vicinity, southern Nevada; data report and preliminary results
Hoffman, L.R.; Mooney, W.D.
1983-01-01
From 1980 to 1982, the U.S. Geological Survey conducted seismic refraction studies at the Nevada Test Site to aid in an investigation of the regional crustal structure at a possible nuclear waste repository site near Yucca Mountain. Two regionally distributed deployments and one north-south deployment recorded nuclear events. First arrival times from these deployments were plotted on a location map and contoured to determine traveltime delays. The results indicate delays as large as 0.5 s in the Yucca Mountain and Crater Flat areas relative to the Jackass Flats area. A fourth east-west deployment recorded a chemical explosion and was interpreted using a two-dimensional computer raytracing technique. Delays as high as 0.7 s were observed over Crater Flat and Yucca Mountain. The crustal model derived from this profile indicates that Paleozoic rocks, which outcrop to the east at Skull Mountain and the Calico Hills, and to the west at Bare Mountain, lie at a minimum depth of 3 km beneath part of Yucca Mountain. These results confirm earlier estimates based on the modeling of detailed gravity data. A mid-crustal boundary at 15 ? 2 km beneath Yucca Mountain is evidenced by a prominent reflection recorded beyond 43 km range at 1.5 s reduced time. Other mid-crustal boundaries have been identified at 24 and 30 km and the total crustal thickness is 35 km.
Geologic map of the Yucca Mountain region, Nye County, Nevada
Potter, Christopher J.; Dickerson, Robert P.; Sweetkind, Donald S.; Drake II, Ronald M.; Taylor, Emily M.; Fridrich, Christopher J.; San Juan, Carma A.; Day, Warren C.
2002-01-01
Yucca Mountain, Nye County, Nev., has been identified as a potential site for underground storage of high-level radioactive waste. This geologic map compilation, including all of Yucca Mountain and Crater Flat, most of the Calico Hills, western Jackass Flats, Little Skull Mountain, the Striped Hills, the Skeleton Hills, and the northeastern Amargosa Desert, portrays the geologic framework for a saturated-zone hydrologic flow model of the Yucca Mountain site. Key geologic features shown on the geologic map and accompanying cross sections include: (1) exposures of Proterozoic through Devonian strata inferred to have been deformed by regional thrust faulting and folding, in the Skeleton Hills, Striped Hills, and Amargosa Desert near Big Dune; (2) folded and thrust-faulted Devonian and Mississippian strata, unconformably overlain by Miocene tuffs and lavas and cut by complex Neogene fault patterns, in the Calico Hills; (3) the Claim Canyon caldera, a segment of which is exposed north of Yucca Mountain and Crater Flat; (4) thick densely welded to nonwelded ash-flow sheets of the Miocene southwest Nevada volcanic field exposed in normal-fault-bounded blocks at Yucca Mountain; (5) upper Tertiary and Quaternary basaltic cinder cones and lava flows in Crater Flat and at southernmost Yucca Mountain; and (6) broad basins covered by Quaternary and upper Tertiary surficial deposits in Jackass Flats, Crater Flat, and the northeastern Amargosa Desert, beneath which Neogene normal and strike-slip faults are inferred to be present on the basis of geophysical data and geologic map patterns. A regional thrust belt of late Paleozoic or Mesozoic age affected all pre-Tertiary rocks in the region; main thrust faults, not exposed in the map area, are interpreted to underlie the map area in an arcuate pattern, striking north, northeast, and east. The predominant vergence of thrust faults exposed elsewhere in the region, including the Belted Range and Specter Range thrusts, was to the east, southeast, and south. The vertical to overturned strata of the Striped Hills are hypothesized to result from successive stacking of three south-vergent thrust ramps, the lowest of which is the Specter Range thrust. The CP thrust is interpreted as a north-vergent backthrust that may have been roughly contemporaneous with the Belted Range and Specter Range thrusts. The southwest Nevada volcanic field consists predominantly of a series of silicic tuffs and lava flows ranging in age from 15 to 8 Ma. The map area is in the southwestern quadrant of the southwest Nevada volcanic field, just south of the Timber Mountain caldera complex. The Claim Canyon caldera, exposed in the northern part of the map area, contains thick deposits of the 12.7-Ma Tiva Canyon Tuff, along with widespread megabreccia deposits of similar age, and subordinate thick exposures of other 12.8- to 12.7-Ma Paintbrush Group rocks. An irregular, blocky fault array, which affects parts of the caldera and much of the nearby area, includes several large-displacement, steeply dipping faults that strike radially to the caldera and bound south-dipping blocks of volcanic rock. South and southeast of the Claim Canyon caldera, in the area that includes Yucca Mountain, the Neogene fault pattern is dominated by closely spaced, north-northwest- to north-northeast-striking normal faults that lie within a north-trending graben. This 20- to 25-km-wide graben includes Crater Flat, Yucca Mountain, and Fortymile Wash, and is bounded on the east by the 'gravity fault' and on the west by the Bare Mountain fault. Both of these faults separate Proterozoic and Paleozoic sedimentary rocks in their footwalls from Miocene volcanic rocks in their hanging walls. Stratigraphic and structural relations at Yucca Mountain demonstrate that block-bounding faults were active before and during eruption of the 12.8- to 12.7-Ma Paintbrush Group, and significant motion on these faults continued unt
Hydrogeology of rocks penetrated by test well JF-3, Jackass Flats, Nye County, Nevada
DOE Office of Scientific and Technical Information (OSTI.GOV)
Plume, R.W.; La Camera, R.J.
1996-12-31
The U.S. Department of Energy and U.S. Geological Survey are monitoring water levels in southern Nevada and adjacent parts of California in response to concern about the potential effects of pumping ground water to support the Yucca Mountain Site-Characterization Program. Well JF-3 was drilled in the western part of Jackass Flats for monitoring water levels, for determining the likelihood of a hydraulic connection between well JF-3 and production wells J-12 and J-13, and for measuring the hydraulic properties of the Topopah Spring Tuff. The borehole for JF-3 penetrated about 480 feet of alluvium and 818 feet of underlying volcanic rock.more » The well was finished at a depth of 1,138 feet below land surface near the base of the Topopah Spring Tuff, which is the principal volcanic-rock aquifer in the area. The Topopah Spring Tuff at well JF-3 extends from depths of 580 feet to 1,140 feet and consists of about 10 feet of partly to moderately welded ash-flow tuff; 10 feet of vitrophyre; 440 feet of devitrified, moderately to densely welded ash-flow tuff; 80 feet of densely welded ash-flow tuff; 10 feet of vitric, nonwelded to partly welded ash-flow tuff; and 10 feet of ashfall tuff. Fractures and lithophysae are most common in the devitrified tuff, especially between depths of 600 feet and 1,040 feet. Much of the water produced in well JF-3 probably comes from the sequence of these devitrified tuffs that is below the water table. The transmissivity of the aquifer is an estimated 140,000-160,000 feet squared per day and hydraulic conductivity is 330-370 feet per day. These values exceed estimates made at well J-13 by two orders of magnitude. Such large differences may be accounted for by differences in the development of fractures and lithophysae in the Topopah Spring Tuff at the two wells.« less
Waddell, R.K.
1982-01-01
A two-dimensional, steady-state model of ground-water flow beneath the Nevada Test Site and vicinity has been developed using inverse techniques. The area is underlain by clastic and carbonate rocks of Precambrian and Paleozoic age and by volcanic rocks and alluvium of Tertiary and Quaternary age that have been juxtaposed by normal and strike-slip faulting. Aquifers are composed of carbonate and volcanic rocks and alluvium. Characteristics of the flow system are determined by distribution of low-conductivity rocks (barriers); by recharge originating in the Spring Mountains, Pahranagat, Timpahute, and Sheep Ranges, and in Pahute Mesa; and by underflow beneath Pahute Mesa from Gold Flat and Kawich Valley. Discharge areas (Ash Meadows, Oasis Valley, Alkali Flat, and Furnace Creek Ranch) are upgradient from barriers. Sensitivities of simulated hydraulic heads and fluxes to variations in model parameters were calculated to guide field studies and to help estimate errors in predictions from transport modeling. Hydraulic heads and fluxes are very sensitive to variations in the greater magnitude recharge/discharge terms. Transmissivity at a location may not be the most important transmissivity for determining flux there. Transmissivities and geometries of large barriers that impede flow from Pahute Mesa have major effects on fluxes elsewhere; as their transmissivities are decreased, flux beneath western Jackass Flats and Yucca Mountains is increased as water is diverted around the barriers. Fortymile Canyon is underlain by highly transmissive rocks that cause potentiometric contours to vee upgradient; increasing their transmissivity increases flow through them, and decreases it beneath Yucca Mountain. (USGS)
Flight test measurements and analysis of sonic boom phenomena near the shock wave extremity
NASA Technical Reports Server (NTRS)
Haglund, G. T.; Kane, E. J.
1973-01-01
The sonic boom flight test program conducted at Jackass Flats, Nevada, during the summer and fall of 1970 consisted of 121 sonic-boom-generating flights over the 1500 ft instrumented BREN tower. This test program was designed to provide information on several aspects of sonic boom, including caustics produced by longitudinal accelerations, caustics produced by steady flight near the threshold Mach number, sonic boom characteristics near lateral cutoff, and the vertical extent of shock waves attached to near-sonic airplanes. The measured test data, except for the near-sonic flight data, were analyzed in detail to determine sonic boom characteristics for these flight conditions and to determine the accuracy and the range of validity of linear sonic boom theory. The caustic phenomena observed during the threshold Mach number flights and during the transonic acceleration flights are documented and analyzed in detail. The theory of geometric acoustics is shown to be capable of predicting shock wave-ground intersections, and current methods for calculating sonic boom pressure signature away from caustics are shown to be reasonably accurate.
Extracting flat-field images from scene-based image sequences using phase correlation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Caron, James N., E-mail: Caron@RSImd.com; Montes, Marcos J.; Obermark, Jerome L.
Flat-field image processing is an essential step in producing high-quality and radiometrically calibrated images. Flat-fielding corrects for variations in the gain of focal plane array electronics and unequal illumination from the system optics. Typically, a flat-field image is captured by imaging a radiometrically uniform surface. The flat-field image is normalized and removed from the images. There are circumstances, such as with remote sensing, where a flat-field image cannot be acquired in this manner. For these cases, we developed a phase-correlation method that allows the extraction of an effective flat-field image from a sequence of scene-based displaced images. The method usesmore » sub-pixel phase correlation image registration to align the sequence to estimate the static scene. The scene is removed from sequence producing a sequence of misaligned flat-field images. An average flat-field image is derived from the realigned flat-field sequence.« less
Code of Federal Regulations, 2012 CFR
2012-07-01
... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Mud flats. 230.42 Section 230.42 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1... Aquatic Sites § 230.42 Mud flats. (a) Mud flats are broad flat areas along the sea coast and in coastal...
Code of Federal Regulations, 2013 CFR
2013-07-01
... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Mud flats. 230.42 Section 230.42 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1... Aquatic Sites § 230.42 Mud flats. (a) Mud flats are broad flat areas along the sea coast and in coastal...
Code of Federal Regulations, 2010 CFR
2010-07-01
... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Mud flats. 230.42 Section 230.42 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1... Aquatic Sites § 230.42 Mud flats. (a) Mud flats are broad flat areas along the sea coast and in coastal...
Code of Federal Regulations, 2014 CFR
2014-07-01
... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Mud flats. 230.42 Section 230.42 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1... Aquatic Sites § 230.42 Mud flats. (a) Mud flats are broad flat areas along the sea coast and in coastal...
Code of Federal Regulations, 2011 CFR
2011-07-01
... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Mud flats. 230.42 Section 230.42 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING SECTION 404(b)(1... Aquatic Sites § 230.42 Mud flats. (a) Mud flats are broad flat areas along the sea coast and in coastal...
Responses of estuarine circulation and salinity to the loss of intertidal flats – A modeling study
Yang, Zhaoqing; Wang, Taiping
2015-08-25
Intertidal flats in estuaries are coastal wetlands that provide critical marine habitats to support wide ranges of marine species. Over the last century many estuarine systems have experienced significant loss of intertidal flats due to anthropogenic impacts. This paper presents a modeling study conducted to investigate the responses of estuarine hydrodynamics to the loss of intertidal flats caused by anthropogenic actions in Whidbey Basin of Puget Sound on the northwest coast of North America. Changes in salinity intrusion limits in the estuaries, salinity stratification, and circulation in intertidal flats and estuaries were evaluated by comparing model results under the existingmore » baseline condition and the no-flat condition. Model results showed that loss of intertidal flats results in an increase in salinity intrusion, stronger mixing, and a phase shift in salinity and velocity fields in the bay front areas. Model results also indicated that loss of intertidal flats enhances two-layer circulation, especially the bottom water intrusion. Loss of intertidal flats increases the mean salinity but reduces the salinity range in the subtidal flats over a tidal cycle because of increased mixing. Salinity intrusion limits extend upstream in all three major rivers discharging into Whidbey Basin when no intertidal flats are present. Changes in salinity intrusion and estuarine circulation patterns due to loss of intertidal flats affect the nearshore habitat and water quality in estuaries and potentially increase risk of coastal hazards, such as storm surge and coastal flooding. Furthermore, model results suggested the importance of including intertidal flats and the wetting-and-drying process in hydrodynamic simulations when intertidal flats are present in the model domain.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, Zhaoqing; Wang, Taiping
Intertidal flats in estuaries are coastal wetlands that provide critical marine habitats to support wide ranges of marine species. Over the last century many estuarine systems have experienced significant loss of intertidal flats due to anthropogenic impacts. This paper presents a modeling study conducted to investigate the responses of estuarine hydrodynamics to the loss of intertidal flats caused by anthropogenic actions in Whidbey Basin of Puget Sound on the northwest coast of North America. Changes in salinity intrusion limits in the estuaries, salinity stratification, and circulation in intertidal flats and estuaries were evaluated by comparing model results under the existingmore » baseline condition and the no-flat condition. Model results showed that loss of intertidal flats results in an increase in salinity intrusion, stronger mixing, and a phase shift in salinity and velocity fields in the bay front areas. Model results also indicated that loss of intertidal flats enhances two-layer circulation, especially the bottom water intrusion. Loss of intertidal flats increases the mean salinity but reduces the salinity range in the subtidal flats over a tidal cycle because of increased mixing. Salinity intrusion limits extend upstream in all three major rivers discharging into Whidbey Basin when no intertidal flats are present. Changes in salinity intrusion and estuarine circulation patterns due to loss of intertidal flats affect the nearshore habitat and water quality in estuaries and potentially increase risk of coastal hazards, such as storm surge and coastal flooding. Furthermore, model results suggested the importance of including intertidal flats and the wetting-and-drying process in hydrodynamic simulations when intertidal flats are present in the model domain.« less
Flat space (higher spin) gravity with chemical potentials
NASA Astrophysics Data System (ADS)
Gary, Michael; Grumiller, Daniel; Riegler, Max; Rosseel, Jan
2015-01-01
We introduce flat space spin-3 gravity in the presence of chemical potentials and discuss some applications to flat space cosmology solutions, their entropy, free energy and flat space orbifold singularity resolution. Our results include flat space Einstein gravity with chemical potentials as special case. We discover novel types of phase transitions between flat space cosmologies with spin-3 hair and show that the branch that continuously connects to spin-2 gravity becomes thermodynamically unstable for sufficiently large temperature or spin-3 chemical potential.
Flat epithelial atypia and atypical ductal hyperplasia: carcinoma underestimation rate.
Ingegnoli, Anna; d'Aloia, Cecilia; Frattaruolo, Antonia; Pallavera, Lara; Martella, Eugenia; Crisi, Girolamo; Zompatori, Maurizio
2010-01-01
This study was carried out to determine the underestimation rate of carcinoma upon surgical biopsy after a diagnosis of flat epithelial atypia and atypical ductal hyperplasia and 11-gauge vacuum-assisted breast biopsy. A retrospective review was conducted of 476 vacuum-assisted breast biopsy performed from May 2005 to January 2007 and a total of 70 cases of atypia were identified. Fifty cases (71%) were categorized as pure atypical ductal hyperplasia, 18 (26%) as pure flat epithelial atypia and two (3%) as concomitant flat epithelial atypia and atypical ductal hyperplasia. Each group were compared with the subsequent open surgical specimens. Surgical biopsy was performed in 44 patients with atypical ductal hyperplasia, 15 patients with flat epithelial atypia, and two patients with flat epithelial atypia and atypical ductal hyperplasia. Five cases of atypical ductal hyperplasia were upgraded to ductal carcinoma in situ, three cases of flat epithelial atypia yielded one ductal carcinoma in situ and two cases of invasive ductal carcinoma, and one case of flat epithelial atypia/atypical ductal hyperplasia had invasive ductal carcinoma. The overall rate of malignancy was 16% for atypical ductal hyperplasia (including flat epithelial atypia/atypical ductal hyperplasia patients) and 20% for flat epithelial atypia. The presence of flat epithelial atypia and atypical ductal hyperplasia at biopsy requires careful consideration, and surgical excision should be suggested.
49 CFR 173.175 - Permeation devices.
Code of Federal Regulations, 2011 CFR
2011-10-01
..., flat and horizontal surface from a height of 1.8 m (5.9 feet): (i) One drop flat on the bottom; (ii) One drop flat on the top; (iii) One drop flat on the long side; (iv) One drop flat on the short side... stacked to a height of 3 m (10 feet) (including the test sample). (3) Each of the above tests may be...
49 CFR 178.609 - Test requirements for packagings for infectious substances.
Code of Federal Regulations, 2011 CFR
2011-10-01
... free-fall drops onto a rigid, nonresilient, flat, horizontal surface from a height of 9 m (30 feet... must be dropped, one in each of the following orientation: (i) Flat on the base; (ii) Flat on the top; (iii) Flat on the longest side; (iv) Flat on the shortest side; and (v) On a corner. (2) Where the...
49 CFR 173.175 - Permeation devices.
Code of Federal Regulations, 2014 CFR
2014-10-01
..., flat and horizontal surface from a height of 1.8 m (5.9 feet): (i) One drop flat on the bottom; (ii) One drop flat on the top; (iii) One drop flat on the long side; (iv) One drop flat on the short side; (v) One drop on a corner at the junction of three intersecting edges; and (2) A force applied to the...
49 CFR 173.175 - Permeation devices.
Code of Federal Regulations, 2013 CFR
2013-10-01
..., flat and horizontal surface from a height of 1.8 m (5.9 feet): (i) One drop flat on the bottom; (ii) One drop flat on the top; (iii) One drop flat on the long side; (iv) One drop flat on the short side; (v) One drop on a corner at the junction of three intersecting edges; and (2) A force applied to the...
Carr, W.J.; Byers, F.M.; Orkild, Paul P.
1984-01-01
The Crater Flat Tuff is herein revised to include a newly recognized lowest unit, the Tram Member, exposed at scattered localities in the southwest Nevada Test Site region, and in several drill holes in the Yucca Mountain area. The overlying Bullfrog and Prow Pass Members are well exposed at the type locality of the formation near the southeast edge of Crater Flat, just north of U.S. Highway 95. In previous work, the Tram Member was thought to be the Bullfrog Member, and therefore was shown as Bullfrog or as undifferentiated Crater Flat Tuff on published maps. The revised Crater Flat Tuff is stratigraphically below the Topopah Spring Member of the Paintbrush Tuff and above the Grouse Canyon Member of the Belted Range Tuff, and is approximately 13.6 m.y. old. Drill holes on Yucca Mountain and near Fortymile Wash penetrate all three members of the Crater Flat as well as an underlying quartz-poor unit, which is herein defined as the Lithic Ridge Tuff from exposures on Lithic Ridge near the head of Topopah Wash. In outcrops between Calico Hills and Yucca Flat, the Lithic Ridge Tuff overlies a Bullfrog-like unit of reverse magnetic polarity that probably correlates with a widespread unit around and under Yucca Flat, referred to previously as Crater Flat Tuff. This unit is here informally designated as the tuff of Yucca Flat. Although older, it may be genetically related to the Crater Flat Tuff. Although the rocks are poorly exposed, geophysical and geologic evidence to date suggests that (1) the source of the Crater Flat Tuff is a caldera complex in the Crater Flat area between Yucca Mountain and Bare Mountain, and (2) there are at least two cauldrons within this complex--one probably associated with eruption of the Tram, the other with the Bullfrog and Prow Pass Members. The complex is named the Crater Flat-Prospector Pass caldera complex. The northern part of the Yucca Mountain area is suggested as the general location of the source of pre-Crater Flat tuffs, but a caldera related to the Lithic Ridge Tuff has not been specifically identified.
Flat conductor cable commercialization project
NASA Technical Reports Server (NTRS)
Hogarth, P.; Wadsworth, E.
1977-01-01
An undercarpet flat conductor cable and a baseboard flat conductor cable system were studied for commercialization. The undercarpet system is designed for use in office and commercial buildings. It employs a flat power cable, protected by a grounded metal shield, that terminates in receptacles mounted on the floor. It is designed to interface with a flat conductor cable telephone system. The baseboard system consists of a flat power cable mounted in a plastic raceway; both the raceway and the receptacles are mounted on the surface of the baseboard. It is designed primarily for use in residential buildings, particularly for renovation and concrete and masonry construction.
Statistical Properties of a Two-Stage Procedure for Creating Sky Flats
NASA Astrophysics Data System (ADS)
Crawford, R. W.; Trueblood, M.
2004-05-01
Accurate flat fielding is an essential factor in image calibration and good photometry, yet no single method for creating flat fields is both practical and effective in all cases. At Winer Observatory, robotic telescope opera- tion and the research program of Near Earth Object follow-up astrometry favor the use of sky flats formed from the many images that are acquired during a night. This paper reviews the statistical properties of the median-combine process used to create sky flats and discusses a computationally efficient procedure for two-stage combining of many images to form sky flats with relatively high signal-to-noise ratio (SNR). This procedure is in use at Winer for the flat field calibration of unfiltered images taken for NEO follow-up astrometry.
Experience in designing and using a flat structure in a multi-project research organization
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kurstedt, H.A. Jr.; Gardner, E.J.; Hindman, T.B. Jr.
1990-01-01
In early 1986, the organization of the Management Systems Laboratories (MSL) was changed from a standard matrix to a flat organization. The flat organization contributed more negative influences on the organization and its goals than positive ones. One year later, the flat organization was changed to a standard hierarchy and most negative influences were overcome. Before, during, and after the flat organization, MSL saw significant growth in funding and in its resource needs. This paper is an account of an experience with a type of flat organization, why we changed to that organization, what worked and what didn't, why wemore » changed away from that organization, what we learned from the experience, and what we would recommend for research organizations considering flat organizations. The authors include the founder and director of MSL, a senior manager during the experience who informally served as historian, and a manager in the organization that sponsored much of MSL's research during MSL's experience with a flat organization. 1 fig.« less
The study method of estimation tidal flat with remote sensing waterlines
NASA Astrophysics Data System (ADS)
Gao, Zhiqiang; Liu, Xiangyang; Zhang, Yuanyuan; Liu, Chaoshun; Sun, Zhibin
2016-09-01
A tidal flat, the important potential land resource, is the sensitive area of intersection between the sea and the land. With Chinese HJ-1A/B remote sensing images of 2014 as data sources, based on the definition of a tidal flat, using DSAS software and Jenks Natural Breaks classification method synthetically, a more reasonable and accurate method of extracting tidal flat was imposed. In addition, the Bohai Rim was taken as an example to carry out investigation on the current situation of tidal flat. This paper can provide basic date and scientific evidence for rational utilization and sustainable development of tidal flat.
A Cochrane review of the evidence for non-surgical interventions for flexible pediatric flat feet.
Evans, A M; Rome, K
2011-03-01
The pediatric flat foot is a frequent presentation in clinical practice, a common concern to parents and continues to be debated within professional ranks. As an entity, it is confused by varied classifications, the notion of well-intended prevention and unsubstantiated, if common, treatment. The available prevalence estimates are all limited by variable sampling, assessment measures and age groups and hence result in disparate findings (0.6-77.9%). Consistently, flat foot has been found to normally reduce with age. The normal findings of flat foot versus children's age estimates that approximately 45% of preschool children, and 15% of older children (average age 10 years) have flat feet. Few flexible flat feet have been found to be symptomatic. Joint hypermobility and increased weight or obesity may increase flat foot prevalence, independently of age. Most attempts at classification of flat foot morphology include the arch, heel position and foot flexibility. Usual assessment methods are footprint measures, X-rays and visual (scaled) observations. There is no standardized framework from which to evaluate the pediatric flat foot. The pediatric flat foot is often unnecessarily treated, being ill-defined and of uncertain prognosis. Contemporary management of the pediatric flat foot is directed algorithmically within this review, according to pain, age, flexibility; considering gender, weight, and joint hypermobility. When foot orthoses are indicated, inexpensive generic appliances will usually suffice. Customised foot orthoses should be reserved for children with foot pain and arthritis, for unusual morphology, or unresponsive cases. Surgery is rarely indicated for pediatric flat foot (unless rigid) and only at the failure of thorough conservative management. The assessment of the pediatric flatfoot needs to be considered with reference to the epidemiological findings, where there is consensus that pediatric flexible flat foot reduces with age and that most children are asymptomatic. Globally, there is need for a standard by which the pediatric flat foot is assessed classified and managed. Until then, assessment should utilize the available evidence-based management model, the p-FFP Future research needs to evaluate the pediatric flat foot from representative samples, of healthy and known disease-group children prospectively, and using validated assessment instruments. The preliminary findings of the benefits of foot exercises, and discrete investigation into the effects of shoes and footwear use are also warranted.
The influence of groundwater depth on coastal dune development at sand flats close to inlets
NASA Astrophysics Data System (ADS)
Silva, Filipe Galiforni; Wijnberg, Kathelijne M.; de Groot, Alma V.; Hulscher, Suzanne J. M. H.
2018-05-01
A cellular automata model is used to analyze the effects of groundwater levels and sediment supply on aeolian dune development occurring on sand flats close to inlets. The model considers, in a schematized and probabilistic way, aeolian transport processes, groundwater influence, vegetation development, and combined effects of waves and tides that can both erode and accrete the sand flat. Next to three idealized cases, a sand flat adjoining the barrier island of Texel, the Netherlands, was chosen as a case study. Elevation data from 18 annual LIDAR surveys was used to characterize sand flat and dune development. Additionally, a field survey was carried out to map the spatial variation in capillary fringe depth across the sand flat. Results show that for high groundwater situations, sediment supply became limited inducing formation of Coppice-like dunes, even though aeolian losses were regularly replenished by marine import during sand flat flooding. Long dune rows developed for high sediment supply scenarios which occurred for deep groundwater levels. Furthermore, a threshold depth appears to exist at which the groundwater level starts to affect dune development on the inlet sand flat. The threshold can vary spatially depending on external conditions such as topography. On sand flats close to inlets, groundwater is capable of introducing spatial variability in dune growth, which is consistent with dune development patterns found on the Texel sand flat.
Management system of simple rental flats study based on technical aspect and health in Medan city
NASA Astrophysics Data System (ADS)
Novrial; Indra Cahaya, S.
2018-03-01
Medan city is a metropolis city in Sumatera that has slums area. Simple rental flats have been built to overcome the problem. However the preliminary survey result showed that the physical and non-physical environment management of simple rent flats is very bad. This study conducted in 3 simple rent flats. It has observed the simple rent flats environment and has interviewed occupants and related agencies. Results of conducted research showed the occupant’s characteristics based on the largest percentage are Javanese; last education is senior high with self-employed work with average income Rp 1,000,000 – Rp 2,500,000. Waste retribution submitted to their cleanliness except for Amplas simple rent flats, their waste management system does not manage properly and the garbage littered. The number of family members of Wisma Labuhan and Amplas simple rent flats exceeds the regulation number of occupants, so it is crowded and noisy. Physical conditions of Amplas simple rent flats are bad, septic tank is full and are not vacuumed. Clean water sources derived from wells and artesian wll are vulnerable to be contaminated by pollutants such as leachate and bad quality water. It is necessary to improve the physical, basic sanitation, and guidance for the simple rent flats occupants to the management system of Simple Rent Flats.
Dynamic Deformation of Theatrical Flats
NASA Astrophysics Data System (ADS)
Walton, Jamiahus; Martell, Eric; Martell, Verda
2013-03-01
In theatre, flats are used as walls and background scenery. During construction, flats are often built on the ground and then ``walked up,'' where a group of stagehands manually lift one end while another anchors the other end in place. When flats are very large, they can deform during this process. Stiffeners are used to decrease the amount of deformation in the flat. The purpose of this research is to determine the strain along the flat during the process of raising it up with and without stiffeners. We will also explore the effect of the person anchoring the pivot edge of the flat and discuss the safety concerns this presents. This research is part of the Physics of Theatre Project, an interdisciplinary collaboration designed to improve safety, reduce costs, and increase knowledge of physics principles within the technical theatre community.
Device for reducing vehicle aerodynamic resistance
Graham, Sean C.
2006-03-07
A device for reducing vehicle aerodynamic resistance for vehicles having a generally rectangular flat front face comprising a plurality of load bearing struts of a predetermined size attached to the flat front face adjacent the sides and top thereof, a pair of pliable opposing flat sheets having an outside edge portion attached to the flat front face adjacent the sides thereof and an upper edge with a predetermined curve; the opposing flat sheets being bent and attached to the struts to form effective curved airfoil shapes, and a top pliable flat sheet disposed adjacent the top of the flat front face and having predetermined curved side edges, which, when the top sheet is bent and attached to the struts to form an effective curved airfoil shape, mate with the curved upper edges of the opposing sheets to complete the aerodynamic device.
75 FR 51286 - Certain Flat Panel Digital Televisions and Components Thereof; Notice of Investigation
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... Steel Flat Products From India: Final Rescission of Countervailing Duty Administrative Review AGENCY... hot-rolled carbon steel flat products from India. See Antidumping or Countervailing Duty Order... Flat Products from India: Preliminary Rescission of Countervailing Duty Administrative Review, 76 FR...
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78 FR 31577 - Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan
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..., Nickel-Plated Flat-Rolled Steel Products From Japan Determination On the basis of the record \\1... imports from Japan of diffusion-annealed, nickel-plated flat-rolled steel products, provided for primarily... flat-rolled steel products from Japan. Accordingly, effective March 27, 2013, the Commission instituted...
Code of Federal Regulations, 2014 CFR
2014-10-01
... 49 Transportation 4 2014-10-01 2014-10-01 false Flat cars. 231.6 Section 231.6 Transportation... TRANSPORTATION RAILROAD SAFETY APPLIANCE STANDARDS § 231.6 Flat cars. (Cars with sides 12 inches or less above the floor may be equipped the same as flat cars.) (a) Hand brakes—(1) Number. Same as specified for...
Code of Federal Regulations, 2011 CFR
2011-10-01
... 49 Transportation 4 2011-10-01 2011-10-01 false Flat cars. 231.6 Section 231.6 Transportation... TRANSPORTATION RAILROAD SAFETY APPLIANCE STANDARDS § 231.6 Flat cars. (Cars with sides 12 inches or less above the floor may be equipped the same as flat cars.) (a) Hand brakes—(1) Number. Same as specified for...
Code of Federal Regulations, 2012 CFR
2012-10-01
... 49 Transportation 4 2012-10-01 2012-10-01 false Flat cars. 231.6 Section 231.6 Transportation... TRANSPORTATION RAILROAD SAFETY APPLIANCE STANDARDS § 231.6 Flat cars. (Cars with sides 12 inches or less above the floor may be equipped the same as flat cars.) (a) Hand brakes—(1) Number. Same as specified for...
Code of Federal Regulations, 2010 CFR
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Flat cars. 231.6 Section 231.6 Transportation... TRANSPORTATION RAILROAD SAFETY APPLIANCE STANDARDS § 231.6 Flat cars. (Cars with sides 12 inches or less above the floor may be equipped the same as flat cars.) (a) Hand brakes—(1) Number. Same as specified for...
Code of Federal Regulations, 2013 CFR
2013-10-01
... 49 Transportation 4 2013-10-01 2013-10-01 false Flat cars. 231.6 Section 231.6 Transportation... TRANSPORTATION RAILROAD SAFETY APPLIANCE STANDARDS § 231.6 Flat cars. (Cars with sides 12 inches or less above the floor may be equipped the same as flat cars.) (a) Hand brakes—(1) Number. Same as specified for...
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...)] Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Notice of Commission Determinations... countervailing duty order on corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion- resistant carbon steel flat products from Germany and Korea would be likely to lead...
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View of New Big Oak Flat Road seen from Old ...
View of New Big Oak Flat Road seen from Old Wawona Road near location of photograph HAER CA-148-17. Note road cuts, alignment, and tunnels. Devils Dance Floor at left distance. Looking northwest - Big Oak Flat Road, Between Big Oak Flat Entrance & Merced River, Yosemite Village, Mariposa County, CA
78 FR 15376 - Determinations: Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea
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...)] Determinations: Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea On the basis of the record... revocation of the countervailing duty order on corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion-resistant carbon steel flat products from Germany and Korea...
76 FR 15299 - Certain Hot-Rolled Carbon Steel Flat Products From India: Preliminary Rescission of...
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... DEPARTMENT OF COMMERCE International Trade Administration [C-533-821] Certain Hot-Rolled Carbon... on certain hot-rolled carbon steel flat products from India. See Antidumping or Countervailing Duty... products covered under this order are certain hot-rolled flat- rolled carbon steel flat products of a...
NASA Technical Reports Server (NTRS)
Amason, David L.
2008-01-01
The goal of the Solar Dynamics Observatory (SDO) is to understand and, ideally, predict the solar variations that influence life and society. It's instruments will measure the properties of the Sun and will take hifh definition images of the Sun every few seconds, all day every day. The FlatSat is a high fidelity electrical and functional representation of the SDO spacecraft bus. It is a high fidelity test bed for Integration & Test (I & T), flight software, and flight operations. For I & T purposes FlatSat will be a driver to development and dry run electrical integration procedures, STOL test procedures, page displays, and the command and telemetry database. FlatSat will also serve as a platform for flight software acceptance and systems testing for the flight software system component including the spacecraft main processors, power supply electronics, attitude control electronic, gimbal control electrons and the S-band communications card. FlatSat will also benefit the flight operations team through post-launch flight software code and table update development and verification and verification of new and updated flight operations products. This document highlights the benefits of FlatSat; describes the building of FlatSat; provides FlatSat facility requirements, access roles and responsibilities; and, and discusses FlatSat mechanical and electrical integration and functional testing.
FICE in Predicting Colorectal Flat Lesion Histology.
Akarsu, Cevher; Sahbaz, Nuri A; Dural, Ahmet C; Kones, Osman; Binboga, Sinan; Kabuli, Hamit A; Gumusoglu, Alpen Y; Alis, Halil
2017-01-01
Colonoscopy is the gold standard for detection of polyps and is preventive against colorectal cancers. Flat adenomas are small, superficial lesions and have a high rate of going undetected during conventional white-light endoscopy. This article adds to the scant body of literature in English regarding in vivo detection and diagnosis of flat adenomas using Fujinon intelligent color enhancement (FICE) system. In this study, we investigated the diagnosis of flat lesions via the FICE endoscopy system and in vivo histologic diagnostic estimations of flat lesions. This prospective study was conducted in patients who underwent colonoscopy that found flat adenomas. Lesions were classified morphologically with regard to the Paris Classification and sent for histopathologic examination after in vivo histologic diagnostic estimations were made according to Kudo's pit pattern classification. The positive predictive value (PPV), negative predictive value (NPV), specificity, sensitivity, and accuracy of in vivo endoscopic diagnostic estimations of flat lesions with the FICE system were analyzed. A total of 217 flat lesions were identified in 137 patients. Of the lesions, 85.7% were Paris type 0-IIa, and 59.4% were Kudo pit pattern type III. When the FICE diagnostic estimations of flat lesions and final pathology results were considered, PPV was 68.5%, NPV value was 89.6%, sensitivity was 94.7%, specificity was 50.9%, and accuracy was 74.2%. Biologic importance of flat lesions is obscure, as they are usually missed during colonoscopy. The use of novel endoscopic techniques may improve their detection and diagnosis rates.
Flat epithelial atypia of the breast: pathological-radiological correlation.
Solorzano, Silma; Mesurolle, Benoît; Omeroglu, Attila; El Khoury, Mona; Kao, Ellen; Aldis, Ann; Meterissian, Sarkis
2011-09-01
This study was undertaken to determine the prevalence of flat epithelial atypia at ultrasound-guided and stereotactically guided needle biopsies, to describe the mammographic and sonographic features of flat epithelial atypia, and to determine the significance of lesions diagnosed as flat epithelial atypia at imaging-guided needle biopsies. Retrospective review of a database of 1369 consecutive sonographically and stereotactically guided needle biopsies performed during a 12-month period yielded 33 lesions with flat epithelial atypia as the most severe pathologic entity (32 patients). Two radiologists retrospectively reviewed the imaging presentation, by combined consensus, according to the BI-RADS lexicon. Twenty-two of 33 flat epithelial atypia diagnoses (67%) were obtained under stereotactic guidance, and 11 (33%) were obtained under sonographic guidance. Six patients had synchronous breast cancer. Flat epithelial atypia lesions presented mammographically most often as microcalcifications (20/33 [61%]) distributed in a cluster (14/20 [70%]) with amorphous morphology (13/20 [65%]). Sonographically, flat epithelial atypia lesions appeared most often as masses (9/11 [82%]), with an irregular shape (6/9 [67%]), microlobulated margins (5/9 [56%]), and hypoechoic or complex echotexture (7/9 [78%]). Twenty-eight of 33 lesions (85%) were surgically excised, confirming the flat epithelial atypia diagnosis in 11 of the 28 lesions (39%), yielding carcinoma in four (14%) and atypical ductal hyperplasia in six (21%). Columnar cell changes without atypia were diagnosed in four lesions (14%), and lobular carcinoma in situ was diagnosed in three lesions (11%). Mammographic and sonographic presentation of flat epithelial atypia is not specific (clustered amorphous microcalcifications and irregular, hypoechoic or complex masses). Given the underestimation rate of malignancy, surgical excision should be considered when imaging-guided biopsy yields flat epithelial atypia.
Bacher, Klaus; Smeets, Peter; Vereecken, Ludo; De Hauwere, An; Duyck, Philippe; De Man, Robert; Verstraete, Koenraad; Thierens, Hubert
2006-09-01
The aim of this study was to compare the image quality and radiation dose in chest imaging using an amorphous silicon flat-panel detector system and an amorphous selenium flat-panel detector system. In addition, the low-contrast performance of both systems with standard and low radiation doses was compared. In two groups of 100 patients each, digital chest radiographs were acquired with either an amorphous silicon or an amorphous selenium flat-panel system. The effective dose of the examination was measured using thermoluminescent dosimeters placed in an anthropomorphic Rando phantom. The image quality of the digital chest radiographs was assessed by five experienced radiologists using the European Guidelines on Quality Criteria for Diagnostic Radiographic Images. In addition, a contrast-detail phantom study was set up to assess the low-contrast performance of both systems at different radiation dose levels. Differences between the two groups were tested for significance using the two-tailed Mann-Whitney test. The amorphous silicon flat-panel system allowed an important and significant reduction in effective dose in comparison with the amorphous selenium flat-panel system (p < 0.0001) for both the posteroanterior and lateral views. In addition, clinical image quality analysis showed that the dose reduction was not detrimental to image quality. Compared with the amorphous selenium flat-panel detector system, the amorphous silicon flat-panel detector system performed significantly better in the low-contrast phantom study, with phantom entrance dose values of up to 135 muGy. Chest radiographs can be acquired with a significantly lower patient radiation dose using an amorphous silicon flat-panel system than using an amorphous selenium flat-panel system, thereby producing images that are equal or even superior in quality to those of the amorphous selenium flat-panel detector system.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Konstantinidis, Anastasios C.; Olivo, Alessandro; Speller, Robert D.
2011-12-15
Purpose: The x-ray performance evaluation of digital x-ray detectors is based on the calculation of the modulation transfer function (MTF), the noise power spectrum (NPS), and the resultant detective quantum efficiency (DQE). The flat images used for the extraction of the NPS should not contain any fixed pattern noise (FPN) to avoid contamination from nonstochastic processes. The ''gold standard'' method used for the reduction of the FPN (i.e., the different gain between pixels) in linear x-ray detectors is based on normalization with an average reference flat-field. However, the noise in the corrected image depends on the number of flat framesmore » used for the average flat image. The aim of this study is to modify the standard gain correction algorithm to make it independent on the used reference flat frames. Methods: Many publications suggest the use of 10-16 reference flat frames, while other studies use higher numbers (e.g., 48 frames) to reduce the propagated noise from the average flat image. This study quantifies experimentally the effect of the number of used reference flat frames on the NPS and DQE values and appropriately modifies the gain correction algorithm to compensate for this effect. Results: It is shown that using the suggested gain correction algorithm a minimum number of reference flat frames (i.e., down to one frame) can be used to eliminate the FPN from the raw flat image. This saves computer memory and time during the x-ray performance evaluation. Conclusions: The authors show that the method presented in the study (a) leads to the maximum DQE value that one would have by using the conventional method and very large number of frames and (b) has been compared to an independent gain correction method based on the subtraction of flat-field images, leading to identical DQE values. They believe this provides robust validation of the proposed method.« less
A history of intertidal flat area in south San Francisco Bay, California: 1858 to 2005
Jaffe, Bruce; Foxgrover, Amy C.
2006-01-01
A key question in salt pond restoration in South San Francisco Bay is whether sediment sinks created by opening ponds will result in the loss of intertidal flats. Analyses of a series of bathymetric surveys of South San Francisco Bay made from 1858 to 2005 reveal changes in intertidal flat area in both space and time that can be used to better understand the pre-restoration system. This analysis also documents baseline conditions of intertidal flats that may be altered by restoration efforts. From 1858 to 2005, intertidal flat area decreased by about 25% from 69.2 +6.4/-7.6 km2 to 51.2 +4.8/-5.8 km2. Intertidal flats in the north tended to decrease in area during the period of this study whereas those south of Dumbarton Bridge were either stable or increased in area. From 1983 to 2005, intertidal flats south of Dumbarton Bridge increased from 17.6 +1.7/-2.5 km2 to 24.2 +1.0/-1.8 km2. Intertidal flats along the east shore of the bay tended to be more erosional and decreased in area while those along the west shore of the bay did not significantly change in area. Loss of intertidal flats occurred intermittently along the eastern shore of the bay north of the Dumbarton Bridge. There was little or no loss from 1931 to 1956 and from 1983 to 2005. Predictions of future change in intertidal flat area that do not account for this spatial and temporal variability are not likely to be accurate. The causes of the spatial and temporal variability in intertidal flat area in South San Francisco Bay are not fully understood, but appear related to energy available to erode sediments, sediment redistribution from north to south in the bay, and sediment available to deposit on the flats. Improved understanding of sediment input to South San Francisco Bay, especially from Central Bay, how it is likely to change in the future, the redistribution of sediment within the bay, and ultimately its effect on intertidal flat area would aid in the management of restoration of South San Francisco Bay salt ponds.
Imaging the Peruvian flat slab with Rayliegh wave tomography
NASA Astrophysics Data System (ADS)
Knezevic Antonijevic, Sanja
In subduction zones the oceanic plates descend at a broad range of dip angles. A "flat slab" is an oceanic plate that starts to subduct steeply, but bends at 100 km depth and continues almost horizontally for several hundred kilometers. This unusual slab geometry has been linked to various geologic features, including the cessation of arc volcanism, basement core uplifts removed far from subducting margins, and the formation of high plateaus. Despite the prevalence of flat slabs worldwide since the Proterozoic, questions on how flat slabs form, persist, and re-steepen remains a topic of ongoing research. Even less clear is how this phenomenon relates to unusual features observed at the surface. To better understand the causes and consequences of slab flattening I focus on the Peruvian flat slab. This is not only the biggest flat slab region today, but due to the oblique angle at which the Nazca Plate subducts under the South American Plate, it also provides unique opportunity to get insights into the temporal evolution of the flat slab. Using ambient noise and earthquake-generated Rayleigh waves recorded at several contemporary dense seismic networks, I was able to perform unprecedentedly high resolution imaging of the subduction zone in southern Peru. Surprisingly, instead of imaging a vast flat slab region as expected, I found that the flat slab tears and re-steepens north of the subducting Nazca Ridge. The change in slab geometry is associated with variations in the slab's internal strain along strike, as inferred from slab-related anisotropy. Based on newly-discovered features I discuss the critical role of the subducting ridges in the formation and longevity of flat slabs. The slab tear created a new mantle pathway between the torn slab and the flat slab remnant to the east, and is possibly linked to the profound low velocity anomaly located under the eastern corner of the flat slab. Finally, I re-evaluate the connection between slab flattening and volcanic patterns at the surface. These findings have important implications for all present-day and paleo-flat slab regions, such as the one proposed for the western United States during the Laramide orogeny 80-55 Ma.
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... participants to: (1) Charge a flat fee per quotation update; (2) charge a separate flat fee per quotation... to: (1) Charge a flat fee per quotation update; (2) charge a separate flat fee per quotation update... fund the NSX's regulatory oversight of Order Delivery participants. Quotation Update Fee for Existing...
77 FR 65365 - Procurement List; Additions
Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-26
..., Plastic, Clear NSN: 6650-00-NIB-0019--Single Vision, Glass, Clear NSN: 6650-00-NIB-0020--Flat Top 28, Bifocal, Glass, Clear NSN: 6650-00-NIB-0021--Flat Top 35, Bifocal, Glass, Clear NSN: 6650-00-NIB-0022--Flat Top 7x28, Trifocal, Glass, Clear NSN: 6650-00-NIB-0023--Flat Top 8x35, Trifocal, Glass, Clear NSN...
77 FR 35942 - Procurement List; Proposed Additions
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...--Bifocal, Executive, Plastic, Clear NSN: 6650-00-NIB-0019--Single Vision, Glass, Clear NSN: 6650-00-NIB-0020--Flat Top 28, Bifocal, Glass, Clear NSN: 6650-00-NIB-0021--Flat Top 35, Bifocal, Glass, Clear NSN: 6650-00-NIB-0022--Flat Top 7x28, Trifocal, Glass, Clear NSN: 6650-00-NIB-0023--Flat Top 8x35, Trifocal...
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...-835, A-549-817, A-823-811] Certain Hot-Rolled Carbon Steel Flat Products From India, Indonesia, the... steel flat products from India, Indonesia, the People's Republic of China (PRC), Taiwan, Thailand, and... steel flat products from India, Indonesia, the PRC, Taiwan, Thailand, and Ukraine, pursuant to section...
Flat conductor cable design, manufacture, and installation
NASA Technical Reports Server (NTRS)
Angele, W.; Hankins, J. D.
1973-01-01
Pertinent information for hardware selection, design, manufacture, and quality control necessary for flat conductor cable interconnecting harness application is presented. Comparisons are made between round wire cable and flat conductor cable. The flat conductor cable interconnecting harness systems show major cost, weight, and space savings, plus increased system performance and reliability. The design application section includes electrical characteristics, harness design and development, and a full treatise on EMC considerations. Manufacturing and quality control sections pertain primarily to the developed conductor-contact connector system and special flat conductor cable to round wire cable transitions.
Dome flat-field system for 1.3-m Araki Telescope
NASA Astrophysics Data System (ADS)
Yoshikawa, Tomohiro; Ikeda, Yuji; Fujishiro, Naofumi; Ichizawa, Shunsuke; Arai, Akira; Isogai, Mizuki; Yonehara, Atsunori; Kawakita, Hideyo
2012-09-01
We report the system/optics design and performance of the dome flat-field system for the Araki Telescope, a 1.3- m optical/near-infrared telescope at Koyama Astronomical Observatory in Japan. A variety of instruments are attached to the telescope. The optical imager, which is intended to search for exoplanets, requires an illumination flatness within 1% on the focal plane over the 17-arcmin FOV. Illumination flatness at both the pupil plane and the focal plane of the telescope is essential for calibration of the transmittance of the optical system. We devised an optical design for the flat-field system that satisfies illumination flatness at both the focal and pupil planes using the non-sequential ray tracing software LightTools. We considered far-field illumination pattern of the lamps, scattering surface reflectance distribution of the screen, telescope structure, primary/secondary mirrors, and mirror baffles. We achieved a flat illumination distribution of 0.9% at the focal plane. The systems performance was tested by comparison with a cloud-flat frame, which was derived by imaging cloud cover illuminated by city lights. The calibration data for the dome flat-field system agree well with the cloud-flat frame within 1% for the g' and i' bands of the imager, but the r0 band data does not meet the requirement (less than or equal to 2). Moreover, various instruments require a focal plane illuminance ranging over three orders of magnitude. We used six high-power (60W) halogen lamps; the output power is remotely controlled by a thyristor-driven dimmer and a bypass circuit to an autotransformer.
Changes of soil particle size distribution in tidal flats in the Yellow River Delta.
Lyu, Xiaofei; Yu, Junbao; Zhou, Mo; Ma, Bin; Wang, Guangmei; Zhan, Chao; Han, Guangxuan; Guan, Bo; Wu, Huifeng; Li, Yunzhao; Wang, De
2015-01-01
The tidal flat is one of the important components of coastal wetland systems in the Yellow River Delta (YRD). It can stabilize shorelines and protect coastal biodiversity. The erosion risk in tidal flats in coastal wetlands was seldom been studied. Characterizing changes of soil particle size distribution (PSD) is an important way to quantity soil erosion in tidal flats. Based on the fractal scale theory and network analysis, we determined the fractal characterizations (singular fractal dimension and multifractal dimension) soil PSD in a successional series of tidal flats in a coastal wetland in the YRD in eastern China. The results showed that the major soil texture was from silt loam to sandy loam. The values of fractal dimensions, ranging from 2.35 to 2.55, decreased from the low tidal flat to the high tidal flat. We also found that the percent of particles with size ranging between 0.4 and 126 μm was related with fractal dimensions. Tide played a great effort on soil PSD than vegetation by increasing soil organic matter (SOM) content and salinity in the coastal wetland in the YRD. Tidal flats in coastal wetlands in the YRD, especially low tidal flats, are facing the risk of soil erosion. This study will be essential to provide a firm basis for the coast erosion control and assessment, as well as wetland ecosystem restoration.
Shin-Etsu super-high-flat substrate for FPD panel photomask
NASA Astrophysics Data System (ADS)
Ishitsuka, Youkou; Harada, Daijitsu; Watabe, Atsushi; Takeuchi, Masaki
2017-07-01
Recently, high-resolution exposure machine has been developed for production of high-definition (HD) panels, and higher-flat photomask substrates for FPD is being expected for panel makers to produce HD panels. In this presentation, we introduce about Shin-Etsu's advanced technique of producing super-high-flat photomask substrates. Shin-Etsu has developed surface polishing and planarization technology with No.1-quality-IC photomask substrates. Our most advanced IC photomask substrates have gained the highest estimation and appreciation from our customers because of their surface quality (non-defect surface without sub-0.1um size defects) and ultimate flatness (sub-0.1um order having achieved). By scaling up those IC photomask substrate technologies and developing unique large-size processing technologies, we have achieved creating high-flat large substrates, even G10-photomask size as well as regular G6-G8 photomask size. The core technology is that the surface shape of the substrate is completely controlled by the unique method. For example, we can regularly produce a substrate with its flatness of triple 5ums; front side flatness, back side flatness and total thickness variation are all less than 5μm. Furthermore, we are able to supply a substrate with its flatness of triple 3ums for G6-photomask size advanced grade, believed to be needed in near future.
Evaluation of photomask flatness compensation for extreme ultraviolet lithography
NASA Astrophysics Data System (ADS)
Ballman, Katherine; Lee, Christopher; Zimmerman, John; Dunn, Thomas; Bean, Alexander
2016-10-01
As the semiconductor industry continues to strive towards high volume manufacturing for EUV, flatness specifications for photomasks have decreased to below 10nm for 2018 production, however the current champion masks being produced report P-V flatness values of roughly 50nm. Write compensation presents the promising opportunity to mitigate pattern placement errors through the use of geometrically adjusted target patterns which counteract the reticle's flatness induced distortions and address the differences in chucking mechanisms between e-beam write and electrostatic clamping during scan. Compensation relies on high accuracy flatness data which provides the critical topographical components of the reticle to the write tool. Any errors included in the flatness data file are translated to the pattern during the write process, which has now driven flatness measurement tools to target a 6σ reproducibility <1nm. Using data collected from a 2011 Sematech study on the Alpha Demo Tool, the proposed methodology for write compensation is validated against printed wafer results. Topographic features which lack compensation capability must then be held to stringent specifications in order to limit their contributions to the final image placement error (IPE) at wafer. By understanding the capabilities and limitations of write compensation, it is then possible to shift flatness requirements towards the "non-correctable" portion of the reticle's profile, potentially relieving polishers from having to adhere to the current single digit flatness specifications.
29 CFR 778.311 - Flat rate for special job performed in overtime hours.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 29 Labor 3 2011-07-01 2011-07-01 false Flat rate for special job performed in overtime hours. 778... COMPENSATION Special Problems Lump Sum Attributed to Overtime § 778.311 Flat rate for special job performed in... paid a flat rate for a special job performed during overtime hours, without regard to the time actually...
78 FR 75911 - Procurement List; Proposed Additions and Deletions
Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-13
..., Plastic, Clear NSN: 6650-00-NIB-0042--Single Vision, Glass, Clear NSN: 6650-00-NIB-0043--Flat Top 28, Bifocal, Glass, Clear NSN: 6650-00-NIB-0044--Flat Top 35, Bifocal, Glass, Clear NSN: 6650-00-NIB-0045--Flat Top 7x28, Trifocal, Glass, Clear NSN: 6650-00-NIB-0046--Flat Top 8x35, Trifocal, Glass, Clear NSN...
Land claim and loss of tidal flats in the Yangtze Estuary.
Chen, Ying; Dong, Jinwei; Xiao, Xiangming; Zhang, Min; Tian, Bo; Zhou, Yunxuan; Li, Bo; Ma, Zhijun
2016-04-01
Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world's largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km(2), a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics.
Land claim and loss of tidal flats in the Yangtze Estuary
Chen, Ying; Dong, Jinwei; Xiao, Xiangming; Zhang, Min; Tian, Bo; Zhou, Yunxuan; Li, Bo; Ma, Zhijun
2016-01-01
Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world’s largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km2, a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics. PMID:27035525
Land claim and loss of tidal flats in the Yangtze Estuary
NASA Astrophysics Data System (ADS)
Chen, Ying; Dong, Jinwei; Xiao, Xiangming; Zhang, Min; Tian, Bo; Zhou, Yunxuan; Li, Bo; Ma, Zhijun
2016-04-01
Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world’s largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km2, a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics.
Fretting Fatigue with Cylindrical-On-Flat Contact: Crack Nucleation, Crack Path and Fatigue Life
Noraphaiphipaksa, Nitikorn; Manonukul, Anchalee; Kanchanomai, Chaosuan
2017-01-01
Fretting fatigue experiments and finite element analysis were carried out to investigate the influence of cylindrical-on-flat contact on crack nucleation, crack path and fatigue life of medium-carbon steel. The location of crack nucleation was predicted using the maximum shear stress range criterion and the maximum relative slip amplitude criterion. The prediction using the maximum relative slip amplitude criterion gave the better agreement with the experimental result, and should be used for the prediction of the location of crack nucleation. Crack openings under compressive bulk stresses were found in the fretting fatigues with flat-on-flat contact and cylindrical-on-flat contacts, i.e., fretting-contact-induced crack openings. The crack opening stress of specimen with flat-on-flat contact was lower than those of specimens with cylindrical-on-flat contacts, while that of specimen with 60-mm radius contact pad was lower than that of specimen with 15-mm radius contact pad. The fretting fatigue lives were estimated by integrating the fatigue crack growth curve from an initial propagating crack length to a critical crack length. The predictions of fretting fatigue life with consideration of crack opening were in good agreement with the experimental results. PMID:28772522
Accessibility of low-income family flats in North Jakarta city
NASA Astrophysics Data System (ADS)
Feminin, T. A.; Wiranegara, H. W.; Supriatna, Y.
2018-01-01
The majority of relocated, low-income families in North Jakarta city who residing the flats, complained at decreasing their accessibility to the workplaces and to the social facilities. The aim of this research was to identify the changing of their accessibility before and after relocated, viewed from three dimensions: distance, travel time, and travel cost to the workplaces, educational facilities, and shopping areas. The research design was questionnaire survey containing the degree of accessibility before and after resided the flats. Five flats were chosen as cases. Their inhabitants were chosen as respondents which used simple random sampling. The result showed that their flats accessibility to the workplaces in all three dimensions was lower than when they resided in the slum area. Also, in distance and travel time accessibility to shopping areas was lower. Only accessibility to educational facilities measured in those three dimensions was higher after they moved. Supply for affordable public transport from their flats to reach their workplaces is needed to raise their accessibility. Also, they need subsidizeto rent of their flats so the burden to their income lesser.Using the ground space of their flats for retail activities was to make more accessible for their shopping activities.
Feasibility study of a 270V dc flat cable aircraft electrical power distributed system
NASA Astrophysics Data System (ADS)
Musga, M. J.; Rinehart, R. J.
1982-01-01
This report documents the efforts of a one man-year feasibility study to evaluate the usage of flat conductors in place of conventional round wires for a 270 volt direct current aircraft power distribution system. This study consisted of designing electrically equivalent power distribution harnesses in flat conductor configurations for a currently operational military aircraft. Harness designs were established for installation in aircraft airframes which are: (1) All metal, or (2) All composite, or (3) a mixture of both. Flat cables have greater surface areas for heat transfer allowing higher current densities and therefore lighter weight conductors, than with round wires. Flat cables are less susceptible to electromagnetic effects. However, these positive factors are partially offset by installation and maintenance difficulties. This study concludes that the extent of these difficulties can be adequately limited with appropriate modification to present installation and maintenance practices. A comparative analysis of the flat and the round conductor power distribution harnesses was made for weight, cost, maintenance and reliability. The knowledge gained from the design and comparative analysis phases was used to generate design criteria for flat power cable harnesses and to identify and prioritize flat cable harness components and associated production tooling which require development.
Flat colon polyps: what should radiologists know?
Ignjatovic, A; Burling, D; Ilangovan, R; Clark, S K; Taylor, S A; East, J E; Saunders, B P
2010-12-01
With the recent publication of international computed tomography (CT) colonography standards, which aim to improve quality of examinations, this review informs radiologists about the significance of flat polyps (adenomas and hyperplastic polyps) in colorectal cancer pathways. We describe flat polyp classification systems and propose how flat polyps should be reported to ensure patient management strategies are based on polyp morphology as well as size. Indeed, consistency when describing flat polyps is of increasing importance given the strengthening links between CT colonography and endoscopy. Copyright © 2010 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.
Smith, Karl H.
2002-01-01
A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.
Observations of ebb flows on tidal flats: Evidence of dewatering?
NASA Astrophysics Data System (ADS)
Rinehimer, J. P.; Thomson, J. M.; Chickadel, C.
2010-12-01
Incised channels are a common morphological feature of tidal flats. When the flats are inundated, flows are generally forced by the tidally varying sea surface height. During low tide, however, these channels continue to drain throughout flat exposure even without an upstream source of water. While the role of porewater is generally overlooked due to the low permeability of marine muds, it remains the only potential source of flows through the channels during low tide. In situ and remotely sensed observations (Figure 1) at an incised channel on a tidal flat in Willapa Bay from Spring 2010 indicate that dewatering of the flats may be driving these low tide flows. High resolution Aquadopp ADCP velocity profiles are combined with observations from tower-based infrared (IR) video to produce a complete time series of surface velocity measurements throughout low tide. The IR video observations provide a measurement of surface currents even when the channel depth is below the blanking distance of the ADCP (10 cm). As the depth within the channel drops from 50 cm to 10 cm surface velocities increase from 10 cm/s to 60 cm/s even as the tide level drops below the channel flanks and the flats are dry. As the drainage continues, the temperature of the flow rises throughout low tide, mirroring temperatures within the sediment bed on the tidal flat. Drainage salinity falls despite the lack of any freshwater input to the flat indicating that less saline porewater may be the source. The likely source of the drainage water is from the channel flanks where time-lapse video shows slumping and compaction of channel sediments. Velocity profiles, in situ temperatures, and IR observations also are consistent with the presence of fluid muds and a hyperpycnal, density driven outflow at the channel mouth highlighting a possible pathway for sediment delivery from the flats to the main distributary channels of the bay. Figure 1: Time series of tidal flat channel velocities and temperatures. Top: (soild) Water depth within the channel and (dashed) tidal flat elevation. Center: Channel surface velocities as measured by an (black) ADCP and (red) a Fourier technique using infrared video. Bottom: Temperatures of (blue) near bed water downstream of the incised channel, (black) channel outflow, and (red) tidal flat sediment at 10 cm depth within the bed.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-01-09
...] Notice of Intent To Prepare an Environmental Impact Statement for the Proposed Copper Flat Mine Plan of... the Draft EIS. ADDRESSES: You may submit comments related to the Copper Flat EIS Project by any of the... New Mexico Copper Corp. to re-start the Copper Flat Mine located in Sierra County, New Mexico. The...
49 CFR 173.4 - Small quantities for highway and rail.
Code of Federal Regulations, 2011 CFR
2011-10-01
... drops made from a height of 1.8 m (5.9 feet) directly onto a solid unyielding surface without breakage... package: (A) One drop flat on bottom; (B) One drop flat on top; (C) One drop flat on the long side; (D) One drop flat on the short side; and (E) One drop on a corner at the junction of three intersecting...
Maier, I L; Leyhe, J R; Tsogkas, I; Behme, D; Schregel, K; Knauth, M; Schnieder, M; Liman, J; Psychogios, M-N
2018-05-01
One-stop management of mechanical thrombectomy-eligible patients with large-vessel occlusion represents an innovative approach in acute stroke treatment. This approach reduces door-to-reperfusion times by omitting multidetector CT, using flat detector CT as pre-mechanical thrombectomy imaging. The purpose of this study was to compare the diagnostic performance of the latest-generation flat detector CT with multidetector CT. Prospectively derived data from patients with ischemic stroke with large-vessel occlusion and mechanical thrombectomy were analyzed in this monocentric study. All included patients underwent multidetector CT before referral to our comprehensive stroke center and flat detector CT in the angiography suite before mechanical thrombectomy. Diagnosis of early ischemic signs, quantified by the ASPECTS, was compared between modalities using cross tables, the Pearson correlation, and Bland-Altman plots. The predictive value of multidetector CT- and flat detector CT-derived ASPECTS for functional outcome was investigated using area under the receiver operating characteristic curve analysis. Of 25 patients, 24 (96%) had flat detector CT with sufficient diagnostic quality. Median multidetector CT and flat detector CT ASPECTSs were 7 (interquartile range, 5.5-9 and 4.25-8, respectively) with a mean period of 143.6 ± 49.5 minutes between both modalities. The overall sensitivity was 85.1% and specificity was 83.1% for flat detector CT ASPECTS compared with multidetector CT ASPECTS as the reference technique. Multidetector CT and flat detector CT ASPECTS were strongly correlated ( r = 0.849, P < .001) and moderately predicted functional outcome (area under the receiver operating characteristic curve, 0.738; P = .007 and .715; P = .069, respectively). Determination of ASPECTS on flat detector CT is feasible, showing no significant difference compared with multidetector CT ASPECTS and a similar predictive value for functional outcome. Our findings support the use of flat detector CT for emergency stroke imaging before mechanical thrombectomy to reduce door-to-groin time. © 2018 by American Journal of Neuroradiology.
NASA Astrophysics Data System (ADS)
Li, Li; Guan, Weibing; He, Zhiguo; Yao, Yanming; Xia, Yuezhang
2017-11-01
Xiangshan Bay is a semi-enclosed bay in China, in which tidal flats have been substantially reclaimed to support the development of local economies and society over previous decades. The loss of tidal flats has led to changes of tides and locally suspended sediment in the bay. The effects of tidal flat reduction on locally suspended sediment dynamics was investigated using a numerical model forced by tidal data and calibrated by observed tidal elevation and currents. The model satisfactorily reproduces observed water levels, currents, and suspended sediment concentration in the estuary, and therefore is subsequently applied to analyze the impact of tidal flat reclamation on locally suspended sediment transport. After the loss of the tidal flats from 1963 to 2010, the suspended sediment concentrations (SSC) at the bottom boundary layer were reduced/increased in the outer bay/tidal flat areas due to weakened tidal currents. In the inner bay, the SSC values near the bottom level increased from 1963 to 2003 due to the narrowed bathymetry, and then decreased from 2003 to 2010 because of the reduced tidal prism. The model scenarios suggest that: (1) a reduction of tidal flat areas appears to be the main factor for enhancing the transport of sediments up-estuary, due to the increased Eulerian velocity and tidal pumping; (2) A reduction of tidal flat areas impacts on spatial and temporal SSC distribution: reducing the SSC values in the water areas due to the reduced current; and (3) a tidal flat reduction influences the net sediment fluxes: lessening the erosion and inducing higher/lower landward/seaward sediment transportation.
NASA Astrophysics Data System (ADS)
van Hunen, Jeroen; van den Berg, Arie P.; Vlaar, Nico J.
2004-08-01
Shallow flat subduction is a relatively common feature at present-day subduction zones. Several mechanisms to explain this feature have been proposed, and can be subdivided into three groups: overthrusting of the subducting plate, subduction of a plume-generated oceanic plateau, and slab suction forces. We developed a numerical model to investigate these mechanisms and tested it through a comparison of the model results with the observations of the Peru flat slab where all three mechanisms seem to be contributing. The ratio of contributions of overthrusting continent to plateau subduction is in the range of 1:1 to 1:2, and the role of plate suction forces is likely to be significant. By applying the overthrusting continent and plateau subduction mechanisms separately, we were able to determine the most important model parameters for each of the mechanisms. Overthrusting easily results in flat subduction, and the flat slab length is primarily a function of slab age, overriding plate motion and mantle viscosity. An oceanic plateau is much less likely to cause flat subduction, and favorable conditions for flat subduction include a young slab age, long-lived plateau buoyancy after subduction, a strong mantle, and addition of slab suction forces that are large enough to further reduce the subduction dip angle, once the plateau initiates this flattening. Furthermore, we found that even though today flat subduction can be explained with the dominant model parameters within a reasonable range, for a slightly hotter, younger Earth, these flat subduction conditions are much less favorable, and so this style of subduction was probably not present in the past. This contradicts earlier predictions that flat subduction was a more wide-spread phenomenon in the early stages of plate tectonics in a younger earth.
Flat epithelial atypia of the breast.
Lerwill, Melinda F
2008-04-01
Flat epithelial atypia is a presumably neoplastic alteration of terminal duct-lobular units that is characterized by the replacement of the native luminal epithelium by ductal cells demonstrating low-grade cytologic atypia. The atypical cells maintain a "flat" pattern of growth without evidence of architectural atypicality. Morphologic, immunohistochemical, and molecular investigations support that flat epithelial atypia represents an early step in the evolution of low-grade ductal carcinomas. It is frequently seen in association with atypical ductal hyperplasia, low-grade ductal carcinoma in situ, invasive tubular carcinoma, and lobular neoplasia. The risk for subsequent breast carcinoma remains to be defined, but flat epithelial atypia likely represents a nonobligate precursor with an extended time course to progression. Certain benign alterations may superficially mimic its appearance; careful attention to cytologic and architectural characteristics can help one distinguish these unrelated entities from flat epithelial atypia.
Near-field flat focusing mirrors
NASA Astrophysics Data System (ADS)
Cheng, Yu-Chieh; Staliunas, Kestutis
2018-03-01
This article reviews recent progress towards the design of near-field flat focusing mirrors, focusing/imaging light patterns in reflection. An important feature of such flat focusing mirrors is their transverse invariance, as they do not possess any optical axis. We start with a review of the physical background to the different focusing mechanisms of near- and far-field focusing. These near-field focusing devices like flat lenses and the reviewed near-field focusing mirrors can implement planar focusing devices without any optical axis. In contrast, various types of far-field planar focusing devices, such as high-contrast gratings and metasurfaces, unavoidably break the transverse invariance due to their radially symmetrical structures. The particular realizations of near-field flat focusing mirrors including Bragg-like dielectric mirrors and dielectric subwavelength gratings are the main subjects of the review. The first flat focusing mirror was demonstrated with a chirped mirror and was shown to manage an angular dispersion for beam focusing, similar to the management of chromatic dispersion for pulse compression. Furthermore, the reviewed optimized chirped mirror demonstrated a long near-field focal length, hardly achieved by a flat lens or a planar hyperlens. Two more different configurations of dielectric subwavelength gratings that focus a light beam at normal or oblique incidence are also reviewed. We also summarize and compare focusing performance, limitations, and future perspectives between the reviewed flat focusing mirrors and other planar focusing devices including a flat lens with a negative-index material, a planar hyperlens, a high-contrast grating, and a metasurface.
2012-10-10
IrwIn D. OlIn Flat-Top Sector Beams Using Only Array Element Phase Weighting: A Metaheuristic Optimization Approach Sotera Defense Solutions, Inc...2012 Formal Report Flat-Top Sector Beams Using Only Array Element Phase Weighting: A Metaheuristic Optimization Approach Irwin D. Olin* Naval...Manuscript approved June 30, 2012. 1 FLAT-TOP SECTOR BEAMS USING ONLY ARRAY ELEMENT PHASE WEIGHTING: A METAHEURISTIC
Design, development, fabrication and testing of high temperature Flat Conductor Cable (FCC)
NASA Technical Reports Server (NTRS)
Rigling, W. S.
1974-01-01
The results are presented of a development program for a flat, 25-conductor signal cable and a flat, 3-conductor power cable. Flat cables employ conductors made of strips or flattened round copper conductors insulated with polyimide films. It is shown that conductor thickness ranges from 0.003 to 0.010 inch, and begins to soften and loose mechanical strength at temperatures above 200 C.
Lv, Xiaofei; Ma, Bin; Yu, Junbao; Chang, Scott X.; Xu, Jianming; Li, Yunzhao; Wang, Guangmei; Han, Guangxuan; Bo, Guan; Chu, Xiaojing
2016-01-01
Coastal ecosystems play significant ecological and economic roles but are threatened and facing decline. Microbes drive various biogeochemical processes in coastal ecosystems. Tidal flats are critical components of coastal ecosystems; however, the structure and function of microbial communities in tidal flats are poorly understood. Here we investigated the seasonal variations of bacterial communities along a tidal flat series (subtidal, intertidal and supratidal flats) and the factors affecting the variations. Bacterial community composition and diversity were analyzed over four seasons by 16S rRNA genes using the Ion Torrent PGM platform. Bacterial community composition differed significantly along the tidal flat series. Bacterial phylogenetic diversity increased while phylogenetic turnover decreased from subtidal to supratidal flats. Moreover, the bacterial community structure differed seasonally. Canonical correspondence analysis identified salinity as a major environmental factor structuring the microbial community in the sediment along the successional series. Meanwhile, temperature and nitrite concentration were major drivers of seasonal microbial changes. Despite major compositional shifts, nitrogen, methane and energy metabolisms predicted by PICRUSt were inhibited in the winter. Taken together, this study indicates that bacterial community structure changed along the successional tidal flat series and provides new insights on the characteristics of bacterial communities in coastal ecosystems. PMID:27824160
Lv, Xiaofei; Ma, Bin; Yu, Junbao; Chang, Scott X; Xu, Jianming; Li, Yunzhao; Wang, Guangmei; Han, Guangxuan; Bo, Guan; Chu, Xiaojing
2016-11-08
Coastal ecosystems play significant ecological and economic roles but are threatened and facing decline. Microbes drive various biogeochemical processes in coastal ecosystems. Tidal flats are critical components of coastal ecosystems; however, the structure and function of microbial communities in tidal flats are poorly understood. Here we investigated the seasonal variations of bacterial communities along a tidal flat series (subtidal, intertidal and supratidal flats) and the factors affecting the variations. Bacterial community composition and diversity were analyzed over four seasons by 16S rRNA genes using the Ion Torrent PGM platform. Bacterial community composition differed significantly along the tidal flat series. Bacterial phylogenetic diversity increased while phylogenetic turnover decreased from subtidal to supratidal flats. Moreover, the bacterial community structure differed seasonally. Canonical correspondence analysis identified salinity as a major environmental factor structuring the microbial community in the sediment along the successional series. Meanwhile, temperature and nitrite concentration were major drivers of seasonal microbial changes. Despite major compositional shifts, nitrogen, methane and energy metabolisms predicted by PICRUSt were inhibited in the winter. Taken together, this study indicates that bacterial community structure changed along the successional tidal flat series and provides new insights on the characteristics of bacterial communities in coastal ecosystems.
NASA Astrophysics Data System (ADS)
Wang, Zhensheng; Kusky, Timothy M.; Capitanio, Fabio A.
2018-01-01
Water transported by deep subduction to the mantle transition zone (MTZ) that is eventually released and migrates upwards is invoked as a likely cause for hydroweakening and cratonic lithosphere destruction. The destruction of the North China Craton (NCC) during the Mesozoic has been proposed to be related to hydroweakening. However, the source of water related to large-scale craton destruction in the NCC is poorly constrained. Some suggest that the water was mainly released from a flat-lying (or stagnating) slab in the MTZ, whereas others posit that most water was released from a previously existing strongly hydrous MTZ then perturbed by the stagnating subduction in the MTZ layer. In this study, we use numerical modeling to evaluate the water carrying ability of flat-lying slabs in the MTZ with different slab ages and water contents to simulate its maximum value and discuss its potential role on large-scale hydroweakening and craton destruction. Our results reveal that a single flat-lying slab in the MTZ cannot provide enough water for large-scale cratonic lithosphere hydroweakening and thinning. Water estimates invoked for craton destruction as experienced by the NCC can only be the result of long-term piling of multiple slabs in the MTZ or penetrating deeper into the lower mantle.
Exact Riemann solutions of the Ripa model for flat and non-flat bottom topographies
NASA Astrophysics Data System (ADS)
Rehman, Asad; Ali, Ishtiaq; Qamar, Shamsul
2018-03-01
This article is concerned with the derivation of exact Riemann solutions for Ripa model considering flat and non-flat bottom topographies. The Ripa model is a system of shallow water equations accounting for horizontal temperature gradients. In the case of non-flat bottom topography, the mass, momentum and energy conservation principles are utilized to relate the left and right states across the step-type bottom topography. The resulting system of algebraic equations is solved iteratively. Different numerical case studies of physical interest are considered. The solutions obtained from developed exact Riemann solvers are compared with the approximate solutions of central upwind scheme.
57. Mormon Flat Power Plant, Sectional Plans at Elev. 1586, ...
57. Mormon Flat Power Plant, Sectional Plans at Elev. 1586, 1573, Sections GG, FF. January 13, 1926. - Mormon Flat Dam, On Salt River, Eastern Maricopa County, east of Phoenix, Phoenix, Maricopa County, AZ
Sombrero Galaxy Not So Flat After All
2012-04-24
New observations from NASA Spitzer Space Telescope reveal the Sombrero galaxy is not simply a regular flat disk galaxy of stars as previously believed, but a more round elliptical galaxy with a flat disk tucked inside.
Landscape ecological security response to land use change in the tidal flat reclamation zone, China.
Zhang, Runsen; Pu, Lijie; Li, Jianguo; Zhang, Jing; Xu, Yan
2016-01-01
As coastal development becomes a national strategy in Eastern China, land use and landscape patterns have been affected by reclamation projects. In this study, taking Rudong County, China as a typical area, we analyzed land use change and its landscape ecological security responses in the tidal flat reclamation zone. The results show that land use change in the tidal flat reclamation zone is characterized by the replacement of natural tidal flat with agricultural and construction land, which has also led to a big change in landscape patterns. We built a landscape ecological security evaluation system, which consists of landscape interference degree and landscape fragile degree, and then calculated the landscape ecological security change in the tidal flat reclamation zone from 1990 to 2008 to depict the life cycle in tidal flat reclamation. Landscape ecological security exhibited a W-shaped periodicity, including the juvenile stage, growth stage, and maturation stage. Life-cycle analysis demonstrates that 37 years is required for the land use system to transform from a natural ecosystem to an artificial ecosystem in the tidal flat reclamation zone.
Flat bands in fractal-like geometry
NASA Astrophysics Data System (ADS)
Pal, Biplab; Saha, Kush
2018-05-01
We report the presence of multiple flat bands in a class of two-dimensional lattices formed by Sierpinski gasket (SPG) fractal geometries as the basic unit cells. Solving the tight-binding Hamiltonian for such lattices with different generations of a SPG network, we find multiple degenerate and nondegenerate completely flat bands, depending on the configuration of parameters of the Hamiltonian. Moreover, we establish a generic formula to determine the number of such bands as a function of the generation index ℓ of the fractal geometry. We show that the flat bands and their neighboring dispersive bands have remarkable features, the most interesting one being the spin-1 conical-type spectrum at the band center without any staggered magnetic flux, in contrast to the kagome lattice. We furthermore investigate the effect of magnetic flux in these lattice settings and show that different combinations of fluxes through such fractal unit cells lead to a richer spectrum with a single isolated flat band or gapless electron- or holelike flat bands. Finally, we discuss a possible experimental setup to engineer such a fractal flat-band network using single-mode laser-induced photonic waveguides.
New edge-centered photonic square lattices with flat bands
NASA Astrophysics Data System (ADS)
Zhang, Da; Zhang, Yiqi; Zhong, Hua; Li, Changbiao; Zhang, Zhaoyang; Zhang, Yanpeng; Belić, Milivoj R.
2017-07-01
We report a new class of edge-centered photonic square lattices with multiple flat bands, and consider in detail two examples: the Lieb-5 and Lieb-7 lattices. In these lattices, there are 5 and 7 sites in the unit cell and in general, the number is restricted to odd integers. The number of flat bands m in the new Lieb lattices is related to the number of sites N in the unit cell by a simple formula m =(N - 1) / 2. The flat bands reported here are independent of the pseudomagnetic field. The properties of lattices with even and odd number of flat bands are different. We consider the localization of light in such Lieb lattices. If the input beam excites the flat-band mode, it will not diffract during propagation, owing to the strong mode localization. In the Lieb-7 lattice, the beam will also oscillate during propagation and still not diffract. The period of oscillation is determined by the energy difference between the two flat bands. This study provides a new platform for investigating light trapping, photonic topological insulators, and pseudospin-mediated vortex generation.
Coherent driving and freezing of bosonic matter wave in an optical Lieb lattice
Taie, Shintaro; Ozawa, Hideki; Ichinose, Tomohiro; Nishio, Takuei; Nakajima, Shuta; Takahashi, Yoshiro
2015-01-01
Although kinetic energy of a massive particle generally has quadratic dependence on its momentum, a flat, dispersionless energy band is realized in crystals with specific lattice structures. Such macroscopic degeneracy causes the emergence of localized eigenstates and has been a key concept in the context of itinerant ferromagnetism. We report the realization of a “Lieb lattice” configuration with an optical lattice, which has a flat energy band as the first excited state. Our optical lattice potential has various degrees of freedom in its manipulation, which enables coherent transfer of a Bose-Einstein condensate into the flat band. In addition to measuring lifetime of the flat band population for different tight-binding parameters, we investigate the inter-sublattice dynamics of the system by projecting the sublattice population onto the band population. This measurement clearly shows the formation of the localized state with the specific sublattice decoupled in the flat band, and even detects the presence of flat-band breaking perturbations, resulting in the delocalization. Our results will open up the possibilities of exploring the physics of flat bands with a highly controllable quantum system. PMID:26665167
Corrugated cover plate for flat plate collector
Hollands, K. G. Terry; Sibbitt, Bruce
1978-01-01
A flat plate radiant energy collector is providing having a transparent cover. The cover has a V-corrugated shape which reduces the amount of energy reflected by the cover away from the flat plate absorber of the collector.
Measure Guideline. Deep Energy Enclosure Retrofit for Zero Energy Ready House Flat Roofs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Loomis, H.; Pettit, B.
2015-05-29
This Measure Guideline provides design and construction information for a deep energy enclosure retrofit solution of a flat roof assembly. It describes the strategies and procedures for an exterior retrofit of a flat wood-framed roof with brick masonry exterior walls using exterior and interior (framing cavity) insulation. The approach supported in this guide could also be adapted for use with flat wood-framed roofs with wood-framed exterior walls.
Flat-lying semiconductor-insulator interfacial layer in DNTT thin films.
Jung, Min-Cherl; Leyden, Matthew R; Nikiforov, Gueorgui O; Lee, Michael V; Lee, Han-Koo; Shin, Tae Joo; Takimiya, Kazuo; Qi, Yabing
2015-01-28
The molecular order of organic semiconductors at the gate dielectric is the most critical factor determining carrier mobility in thin film transistors since the conducting channel forms at the dielectric interface. Despite its fundamental importance, this semiconductor-insulator interface is not well understood, primarily because it is buried within the device. We fabricated dinaphtho[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT) thin film transistors by thermal evaporation in vacuum onto substrates held at different temperatures and systematically correlated the extracted charge mobility to the crystal grain size and crystal orientation. As a result, we identify a molecular layer of flat-lying DNTT molecules at the semiconductor-insulator interface. It is likely that such a layer might form in other material systems as well, and could be one of the factors reducing charge transport. Controlling this interfacial flat-lying layer may raise the ultimate possible device performance for thin film devices.
Absolute calibration of optical flats
Sommargren, Gary E.
2005-04-05
The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.
NASA Astrophysics Data System (ADS)
Cruz, L.; Nevitt, J. M.; Seixas, G.; Hilley, G. E.
2017-10-01
Kinematic theories of flat-ramp-flat folds relate fault angles to stratal dips in a way that allows prediction of structural geometries in areas of economic or scientific interest. However, these geometric descriptions imply constitutive properties of rocks that might be discordant with field and laboratory measurements. In this study, we compare deformation resulting from kinematic and mechanical models of flat-ramp-flat folds with identical geometries to determine the conditions over which kinematic models may be reasonably applied to folded rocks. Results show that most mechanical models do not conform to the geometries predicted by the kinematic models, and only low basal friction (μ ≤ 0.1) and shallow ramps (ramp angle ≤10°) produce geometries consistent with kinematic predictions. This implies that the kinematic models might be appropriate for a narrow set of geometric and basal fault friction parameters.
Phelps, Geoffrey A.; Justet, Leigh; Moring, Barry C.; Roberts, Carter W.
2006-01-01
New gravity and magnetic data collected in the vicinity of Massachusetts Mountain and CP basin (Nevada Test Site, NV) provides a more complex view of the structural relationships present in the vicinity of CP basin than previous geologic models, helps define the position and extent of structures in southern Yucca Flat and CP basin, and better constrains the configuration of the basement structure separating CP basin and Frenchman Flat. The density and gravity modeling indicates that CP basin is a shallow, oval-shaped basin which trends north-northeast and contains ~800 m of basin-filling rocks and sediment at its deepest point in the northeast. CP basin is separated from the deeper Frenchman Flat basin by a subsurface ridge that may represent a Tertiary erosion surface at the top of the Paleozoic strata. The magnetic modeling indicates that the Cane Spring fault appears to merge with faults in northwest Massachusetts Mountain, rather than cut through to Yucca Flat basin and that the basin is downed-dropped relative to Massachusetts Mountain. The magnetic modeling indicates volcanic units within Yucca Flat basin are down-dropped on the west and supports the interpretations of Phelps and KcKee (1999). The magnetic data indicate that the only faults that appear to be through-going from Yucca Flat into either Frenchman Flat or CP basin are the faults that bound the CP hogback. In general, the north-trending faults present along the length of Yucca Flat bend, merge, and disappear before reaching CP hogback and Massachusetts Mountain or French Peak.
O'Connor, Siobhan; Warrington, Giles; McGoldrick, Adrian; Cullen, SarahJane
2017-12-01
Professional horse racing is considered a high-risk sport, yet the last analysis of fall and injury incidence in this sport in Ireland was completed between 1999 and 2006. To provide an updated analysis of the fall and injury incidence in professional flat and jump horse racing in Ireland from 2011 through 2015, compare it with the previous analysis, and detail the specific types and locations of injuries. Descriptive epidemiology study. A medical doctor recorded all injuries that occurred at every official flat and jump race meeting for the 2011 through 2015 seasons using standardized injury-report forms. Injury and fall rates and their 95% confidence intervals (CIs) were reported for flat and jump racing. Incidence rate ratios and 95% CIs were calculated between flat and jump racing, between the 1999-2006 analysis and the current results, and between 2011 and 2015. The distribution of injuries for type and location of injury was reported. Compared with flat racing, jump racing had significantly more falls per 1000 rides (49.5 versus 3.8), injuries per 1000 rides (10.1 versus 1.4), and injuries per 1000 meetings (776.0 versus 94.1). However, the rate of injuries per 1000 falls was significantly higher in flat racing (352.8 versus 203.8). An increase in injuries per 1000 falls between 2011 and 2015 was found in flat racing ( P = .005). Since the previous analysis, a significant increase in injuries per 1000 rides and falls was noted in jump racing. Soft tissue injuries were predominant in flat and jump racing (61.54% and 68.80%, respectively), with fractures the second most common injury (15.38% and 18.06%, respectively). Concussions were more prevalent from flat-racing falls (incidence rate ratio = 0.30; 95% CI = 0.15, 0.61). The lower limb was the most frequent location of injury (32.89%) in flat racing; however, in jump racing, upper limb injuries (34.97%) were predominant. An update on professional flat- and jump-racing fall and injury epidemiology is provided. Further research to identify risk factors for injury, design and investigate the feasibility of injury-prevention strategies, and document their effects on fall and injury incidence is required.
2013-01-01
Absolute flatness of three silicon plane mirrors have been measured by a three-intersection method based on the three-flat method using a near-infrared interferometer. The interferometer was constructed using a near-infrared laser diode with a 1,310-nm wavelength light where the silicon plane mirror is transparent. The height differences at the coordinate values between the absolute line profiles by the three-intersection method have been evaluated. The height differences of the three flats were 4.5 nm or less. The three-intersection method using the near-infrared interferometer was useful for measuring the absolute flatness of the silicon plane mirrors. PMID:23758916
Measure Guideline: Deep Energy Enclosure Retrofit for Zero Energy Ready House Flat Roofs
DOE Office of Scientific and Technical Information (OSTI.GOV)
Loomis, H.; Pettit, B.
2015-05-01
This Measure Guideline provides design and construction information for a deep energy enclosure retrofit (DEER) solution of a flat roof assembly. It describes the strategies and procedures for an exterior retrofit of a flat, wood-framed roof with brick masonry exterior walls, using exterior and interior (framing cavity) insulation. The approach supported in this guide could also be adapted for use with flat, wood-framed roofs with wood-framed exterior walls.
On-Line Flatness Measurement in the Steelmaking Industry
Molleda, Julio; Usamentiaga, Rubén; Garcίa, Daniel F.
2013-01-01
Shape is a key characteristic to determine the quality of outgoing flat-rolled products in the steel industry. It is greatly influenced by flatness, a feature to describe how the surface of a rolled product approaches a plane. Flatness is of the utmost importance in steelmaking, since it is used by most downstream processes and customers for the acceptance or rejection of rolled products. Flatness sensors compute flatness measurements based on comparing the length of several longitudinal fibers of the surface of the product under inspection. Two main different approaches are commonly used. On the one hand, most mechanical sensors measure the tensile stress across the width of the rolled product, while manufacturing and estimating the fiber lengths from this stress. On the other hand, optical sensors measure the length of the fibers by means of light patterns projected onto the product surface. In this paper, we review the techniques and the main sensors used in the steelmaking industry to measure and quantify flatness defects in steel plates, sheets and strips. Most of these techniques and sensors can be used in other industries involving rolling mills or continuous production lines, such as aluminum, copper and paper, to name a few. Encompassed in the special issue, State-of-the-Art Sensors Technology in Spain 2013, this paper also reviews the most important flatness sensors designed and developed for the steelmaking industry in Spain. PMID:23939583
ACS/WFC Sky Flats from Frontier Fields Imaging
NASA Astrophysics Data System (ADS)
Mack, J.; Lucas, R. A.; Grogin, N. A.; Bohlin, R. C.; Koekemoer, A. M.
2018-04-01
Parallel imaging data from the HST Frontier Fields campaign (Lotz et al. 2017) have been used to compute sky flats for the ACS/WFC detector in order to verify the accuracy of the current set of flat field reference files. By masking sources and then co-adding many deep frames, the F606W and F814W filters have enough combined background signal that from Poisson statistics are <1% per pixel. In these two filters, the sky flats show spatial residuals 1% or less. These residuals are similar in shape to the WFC flat field 'donut' pattern, in which the detector quantum efficiency tracks the thickness of the two WFC chips. Observations of blue and red calibration standards measured at various positions on the detector (Bohlin et al. 2017) confirm the fidelity of the F814W flat, with aperture photometry consistent to 1% across the FOV, regardless of spectral type. At bluer wavelengths, the total sky background is substantially lower, and the F435W sky flat shows a combination of both flat errors and detector artifacts. Aperture photometry of the red standard star shows a maximum deviation of 1.4% across the array in this filter. Larger residuals up to 2.5% are found for the blue standard, suggesting that the spatial sensitivity in F435W depends on spectral type.
On-line flatness measurement in the steelmaking industry.
Molleda, Julio; Usamentiaga, Rubén; García, Daniel F
2013-08-09
Shape is a key characteristic to determine the quality of outgoing flat-rolled products in the steel industry. It is greatly influenced by flatness, a feature to describe how the surface of a rolled product approaches a plane. Flatness is of the utmost importance in steelmaking, since it is used by most downstream processes and customers for the acceptance or rejection of rolled products. Flatness sensors compute flatness measurements based on comparing the length of several longitudinal fibers of the surface of the product under inspection. Two main different approaches are commonly used. On the one hand, most mechanical sensors measure the tensile stress across the width of the rolled product, while manufacturing and estimating the fiber lengths from this stress. On the other hand, optical sensors measure the length of the fibers by means of light patterns projected onto the product surface. In this paper, we review the techniques and the main sensors used in the steelmaking industry to measure and quantify flatness defects in steel plates, sheets and strips. Most of these techniques and sensors can be used in other industries involving rolling mills or continuous production lines, such as aluminum, copper and paper, to name a few. Encompassed in the special issue, State-of-the-Art Sensors Technology in Spain 2013, this paper also reviews the most important flatness sensors designed and developed for the steelmaking industry in Spain.
Structure of the Flat Slab in Southern Peru
NASA Astrophysics Data System (ADS)
Ma, Y.; Clayton, R. W.
2014-12-01
We investigate the detailed structure of the flat-subduction portion of the subduction zone in Southern Peru using converted phases recorded by the PeruSE seismic array. The migrated image along a profile above the flat subduction is shown in the figure, overlain by the receiver functions of one well-recorded event. We see that the slab descends to 100 km depth at a distance of about 100 km inland from the coast, and then it rises to 90 km depth and remains flat for the next 300 km distance before diving into the mantle. The Moho itself has about 10 km relief above the flat slab, which is anti-correlated with the surface topography indicating Airy compensation. Interestingly, the flat slab image is missing under this part of Moho. The mid-crust structure is also evident. In the west, it coincides with the Andean Low Velocity Zone (ALVZ) mapped in this region (Ma and Clayton, 2014). In the east, it is related with the underthrusting Brazilian Shield (Phillips and Clayton, 2014). In this paper, we further investigate the causes of the missing or weak flat slab signal, possibly due to anomalous attenuation of S waves in the mantle wedge (but not P wave, since Moho is well imaged). We will also extend our study to the flat-normal transition area beneath the array.
Flat Foot in a Random Population and its Impact on Quality of Life and Functionality
Gonzalez-Martin, Cristina; Alonso-Tajes, Francisco; Seoane-Pillado, Teresa; Pertega-Diaz, Sonia; Perez-Garcia, Sergio; Seijo-Bestilleiro, Rocio; Balboa-Barreiro, Vanesa
2017-01-01
Introduction Flat foot is a common deformity in adults. It is characterized by medial rotation and plantar flexion of the talus, eversion of the calcaneus, collapsed medial arch and abduction of the forefoot. Aim The aim of this study was to determine the prevalence of flat foot and its impact on quality of life, dependence, foot pain, disability and functional limitation among random population of 40-year-old and above. Materials and Methods A cross-sectional study in a random population sample from Cambre (A Coruña-Spain) (n=835) was performed (α =0.05; Precision=±3.4%). The diagnosis of flat foot was stablished by the study of the footprint obtained with a pedograph. Anthropometric variables were studied, Charlson’s Comorbidity Index, function and state of foot (Foot Function Index (FFI), Foot Health Status Questionnaire (FHSQ)), quality of life (SF-36), and dependence for activities of daily living (Barthel and Lawton index). A logistic and linear multiple regression analysis was performed. Results The prevalence of flat foot was 26.62%. Patients with flat foot were significantly older (65.73±11.04 vs 61.03±11.45-year-old), showed a higher comorbidity index (0.92±1.49 vs 0.50±0.98), had a greater BMI (31.45±5.55 vs 28.40±4.17) and greater foot size (25.16±1.66 vs 24.82±1.65). The presence of flat foot diminishes the quality of life, as measured by the FHSQ, and foot function, measured by the FFI. The presence of flat foot does not alter the physical and mental dimension of the SF-36 or the degree of dependence. Conclusion Flat foot was associated with age, Charlson’s Comorbidity Index, BMI and foot size. The SF-36, Barthel and Lawton questionnaires remained unaltered by the presence of flat foot. The FHSQ and FFI questionnaires did prove to be sensitive to the presence of flat foot in a significant manner. PMID:28571173
Harborne, A R
2013-09-01
Reef flats, typically a low-relief carbonate and sand habitat in shallow water leeward of the reef crest, are one of the most extensive zones on Pacific coral reefs. This shallow zone often supports an abundant and diverse fish assemblage that is exposed to more significant variations in physical factors, such as water depth and movement, temperature and ultraviolet (UV) radiation levels, than most other reef fishes. This review examines the characteristics of reef flat fish assemblages, and then investigates what is known about how they respond to their biophysical environment. Because of the challenges of living in shallow, wave-exposed water, reef flats typically support a distinct fish assemblage compared to other reef habitats. This assemblage clearly changes across tidal cycles as some larger species migrate to deeper water at low tide and other species modify their behaviour, but quantitative data are generally lacking. At least some reef flat fish species are well-adapted to high temperatures, low oxygen concentrations and high levels of UV radiation. These behavioural and physiological adaptations suggest that there may be differences in the demographic processes between reef flat assemblages and those in deeper water. Indeed, there is some evidence that reef flats may act as nurseries for some species, but more research is required. Further studies are also required to predict the effects of climate change, which is likely to have multifaceted impacts on reef flats by increasing temperature, water motion and sediment load. Sea-level rise may also affect reef flat fish assemblages and food webs by increasing the amount of time that larger species are able to forage in this zone. The lack of data on reef flats is surprising given their size and relative ease of access, and a better understanding of their functional role within tropical marine seascapes is urgently required. © 2013 The Fisheries Society of the British Isles.
Reinhart, K; Bannert, C; Dunkler, D; Salzl, P; Trauner, M; Renner, F; Knoflach, P; Ferlitsch, A; Weiss, W; Ferlitsch, M
2013-01-01
Flat lesions pose new challenges for endoscopists, but the importance of detecting them is still controversial. Most screening studies do not survey macroscopic polyp morphology. The aims were to evaluate the percentage of flat polyp findings in a large asymptomatic adult screening population (n = 52 521), to assess the impact of shape and size on malignant transformation, and to assess the role of flat lesions regarding quality assurance in colorectal cancer prevention. Retrospective analysis of screening colonoscopies performed between 2007 and 2011 according to the Austrian "Quality management for colon cancer prevention" program. 17 771 patients with polyps were included in the study. Patients with flat polyps represented 24.2 % (n = 4293), 62.4 % (n = 11 097) were classified as having sessile and 13.4 % (n = 2381) as pedunculated polyps. Among those with flat polyps 51.4 % had adenomas (n = 2207). High grade dysplasia (HGD) was found in 2.1 % (n = 47) of flat adenomas, in 1.5 % (n = 89) of sessile adenomas and 4.7 % (n = 92) of pedunculated adenomas (P < 0.0001. The risk for containing HGD was 1.0 % for flat lesions ≤ 10 mm in size compared with 10.3 % for lesions > 10 mm, and 1.0 % for polypoid lesions ≤ 10 mm compared with 9.3 % for lesions > 10 mm (P < 0.0001). Multivariable logistic regression showed that polyp size (P < 0.0001) but not polyp shape (P = 0.438) is an independent predictor for HGD. Adenoma detection rate (ADR) correlated weakly with the flat polyp detection rate (Pearson r = 0.24). Malignant potential of polyps is mostly affected by size but not by shape. Since flat polyp detection rate only correlates poorly with ADR we do not recommend its incorporation in quality assured screening colonoscopy. © Georg Thieme Verlag KG Stuttgart · New York.
SU-E-T-635: Quantitative Study On Beam Flatness Variation with Beam Energy Change
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, J S; Eldib, A; Ma, C
2014-06-15
Purpose: Beam flatness check has been proposed for beam energy check for photon beams with flattering filters. In this work, beam flatness change with beam energy was investigated quantitatively using the Monte Carlo method and its significance was compared with depth dose curve change. Methods: Monte Carlo simulations for a linear accelerator with flattering filter were performed with different initial electron energies for photon beams of 6MV and 10MV. Dose calculations in a water phantom were then perform with the phase space files obtained from the simulations. The beam flatness was calculated based on the dose profile at 10 cmmore » depth for all the beams with different initial electron energies. The percentage depth dose (PDD) curves were also analyzed. The dose at 10cm depth (D10) and the ratio of the dose at 10cm and 20cm depth (D10/D20) and their change with the beam energy were calculated and compared with the beam flatness variation. Results: It was found that the beam flatness variation with beam energy change was more significant than the change of D10 and the ratio between D10 and D20 for both 6MV and 10MV beams. Half MeV difference on the initial electron beam energy brought in at least 20% variation on the beam flatness but only half percent change on the ratio of D10 and D20. The change of D10 or D20 alone is even less significant. Conclusion: The beam energy impact on PDD is less significant than that on the beam flatness. If the PDD is used for checking the beam energy, uncertainties of the measurement could possibly disguise its change. Beam flatness changes more significantly with beam energy and therefore it can be used for monitoring the energy change for photon beams with flattering filters. However, other factors which may affect the beam flatness should be watched as well.« less
Liang, Jinyang; Kohn, Rudolph N; Becker, Michael F; Heinzen, Daniel J
2009-04-01
We demonstrate a digital micromirror device (DMD)-based optical system that converts a spatially noisy quasi-Gaussian to an eighth-order super-Lorentzian flat-top beam. We use an error-diffusion algorithm to design the binary pattern for the Texas Instruments DLP device. Following the DMD, a telescope with a pinhole low-pass filters the beam and scales it to the desired sized image. Experimental measurements show a 1% root-mean-square (RMS) flatness over a diameter of 0.28 mm in the center of the flat-top beam and better than 1.5% RMS flatness over its entire 1.43 mm diameter. The power conversion efficiency is 37%. We develop an alignment technique to ensure that the DMD pattern is correctly positioned on the incident beam. An interferometric measurement of the DMD surface flatness shows that phase uniformity is maintained in the output beam. Our approach is highly flexible and is able to produce not only flat-top beams with different parameters, but also any slowly varying target beam shape. It can be used to generate the homogeneous optical lattice required for Bose-Einstein condensate cold atom experiments.
Topological properties of flat electroencephalography's state space
NASA Astrophysics Data System (ADS)
Ken, Tan Lit; Ahmad, Tahir bin; Mohd, Mohd Sham bin; Ngien, Su Kong; Suwa, Tohru; Meng, Ong Sie
2016-02-01
Neuroinverse problem are often associated with complex neuronal activity. It involves locating problematic cell which is highly challenging. While epileptic foci localization is possible with the aid of EEG signals, it relies greatly on the ability to extract hidden information or pattern within EEG signals. Flat EEG being an enhancement of EEG is a way of viewing electroencephalograph on the real plane. In the perspective of dynamical systems, Flat EEG is equivalent to epileptic seizure hence, making it a great platform to study epileptic seizure. Throughout the years, various mathematical tools have been applied on Flat EEG to extract hidden information that is hardly noticeable by traditional visual inspection. While these tools have given worthy results, the journey towards understanding seizure process completely is yet to be succeeded. Since the underlying structure of Flat EEG is dynamic and is deemed to contain wealthy information regarding brainstorm, it would certainly be appealing to explore in depth its structures. To better understand the complex seizure process, this paper studies the event of epileptic seizure via Flat EEG in a more general framework by means of topology, particularly, on the state space where the event of Flat EEG lies.
Effects of a flat prosthetic foot rocker section on balance and mobility.
Hansen, Andrew; Nickel, Eric; Medvec, Joseph; Brielmaier, Steven; Pike, Alvin; Weber, Marilyn
2014-01-01
Previous studies have shown that the effective rocker shape of the physiologic ankle-foot system during standing and fore-aft swaying is much flatter than that used during walking, which indicates a more stable base of support for the standing/swaying activity. Previous work suggests that flat regions within the effective rocker shapes of prosthetic ankle-foot systems could provide enhanced stability for standing balance tasks. An experimental prosthetic foot was altered to provide three different flat region lengths within its effective rocker shape. It was hypothesized that longer flat regions of the effective rocker shape would lead to improved standing balance outcomes and reduced walking performance for unilateral transtibial prosthesis users. However, no significant changes were seen in the balance and mobility outcomes of 12 unilateral transtibial prosthesis users when using the three prosthetic foot conditions. Subjects in the study significantly preferred prosthetic feet with relatively low to moderate flat regions over those with long flat regions. All the subjects without loss of light touch or vibratory sensation selected the prosthetic foot with the shortest flat region. More work is needed to investigate the effects of prosthetic foot properties on balance and mobility of prosthesis users.
Effect of Cutting Tool Properties and Depth of Cut in Rock Cutting: An Experimental Study
NASA Astrophysics Data System (ADS)
Rostamsowlat, Iman
2018-06-01
The current paper is designed to investigate the effect of worn (blunt) polycrystalline diamond compact cutter properties on both the contact stress (σ) and friction coefficient ( μ) mobilized at the wear flat-rock interface at different inclination angles of the wear flat surface and at a wide range of depths of cut. An extensive and comprehensive set of cutting experiments is carried out on two sedimentary rocks (one limestone and one sandstone) using a state-of-the-art rock cutting equipment (Wombat) and various blunt cutters. Experiments with blunt cutters are characterized by different wear flat inclination angles (β), different wear flat surface roughness (Ra), different wear flat material, and different cutting tool velocities ({\\varvec{v}}) were conducted. The experimental results show that both the contact stress and friction coefficient are predominantly affected by the wear flat roughness at all inclination angles of the wear flat; however, the cutting tool velocity has a negligible influence on both the contact stress and friction coefficient. Further investigations suggest that the contact stress is greatly affected by the depth of cut within the plastic regime of frictional contact while the contact stress is insensitive to the depth of cut within the elastic regime.
Fenelon, Joseph M.; Moreo, Michael T.
2002-01-01
Ground-water level and discharge data from 1960 to 2000 were analyzed for the Yucca Mountain region of southern Nevada and eastern California. Included were water-level data from 37 wells and a fissure (Devils Hole) and discharge data from five springs and from a flowing well. Data were evaluated for variability and for upward, downward, or cyclic trends with an emphasis on the period 1992-2000. Potential factors causing trends in water levels and discharge include ground-water withdrawal, infiltration of precipitation, earthquakes, evapotranspiration, barometric pressure, and earth tides. Statistically significant trends in ground-water levels or spring discharge from 1992 to 2000 were upward at 12 water-level sites and downward at 14 water-level sites and 1 spring-discharge site. In general, the magnitude of the change in water level from 1992 to 2000 was small (less than 2 feet), except where influenced by pumping or local effects such as possible equilibration from well construction or diversion of nearby surface water. Seasonal trends are superimposed on some of the long-term (1992-2000) trends in water levels and discharge. Factors causing seasonal trends include barometric pressure, evapotranspiration, and pumping. The magnitude of seasonal change in water level can vary from as little as 0.05 foot in regional aquifers to greater than 5 feet in monitoring wells near large supply wells in the Amargosa Farms area. Three major episodes of earthquake activity affected water levels in wells in the Yucca Mountain region between 1992 and 2000: the Landers/Little Skull Mountain, Northridge, and Hector Mine earthquakes. The Landers/Little Skull Mountain earthquakes, in June 1992, had the largest observed effect on water levels and on discharge during the study period. Monthly measurements of wells in the study network show that earthquakes affected water levels from a few tenths of a foot to 3.5 feet. In the Ash Meadows area, water levels remained relatively stable from 1992 to 2000, with some water levels showing small rising trends and some declining slightly. Possible reasons for water-level fluctuations at sites AD-6 (Tracer Well 3), AM-5 (Devils Hole Well), and AM-4 (Devils Hole) from 1960 to 2000 include climate change, local and regional ground-water withdrawals, and tectonic activity. In Jackass Flats, water levels from 1992 to 2000 in six wells adjacent to Fortymile Wash displayed either small upward trends or no upward or downward trend. Comparison of trends in water levels from 1983 to 2000 for these six wells shows good correlations between all wells and suggests a common mechanism controlling water levels in the area. Of the likely controls on the system--precipitation or pumping in Jackass Flats--precipitation appears to be the predominant factor controlling water levels near Fortymile Wash. Water levels in the heavily pumped Amargosa Farms area declined from about 10 to 30 feet from 1964 to 2000. Water-level declines accelerated beginning in the early 1990's as pumping rates increased substantially. Pumping in the Amargosa Farms area may affect water levels in some wells as far away as 5-14 miles. The water level at site DV-3 (Travertine Point 1 Well) and discharge at site DV-2 (Navel Spring), both in the Death Valley hydrographic area, had downward trends from 1992 to 2000. The cause of these downward trends may be linked to earthquakes, pumping in the Amargosa Farms area, or both.
10. Downstream face of Mormon Flat Dam under construction. Cement ...
10. Downstream face of Mormon Flat Dam under construction. Cement storage shed is at center right. Photographer unknown, September 1924. Source: Salt River Project. - Mormon Flat Dam, On Salt River, Eastern Maricopa County, east of Phoenix, Phoenix, Maricopa County, AZ
Bunch Compression of Flat Beams
DOE Office of Scientific and Technical Information (OSTI.GOV)
Halavanau, A.; Piot, P.; Edstrom Jr., D.
Flat beams can be produced via a linear manipulation of canonical-angular-momentum (CAM) dominated beams using a set of skew-quadrupole magnets. Recently, such beams were produced at Fermilab Accelerator Science and Technology (FAST) facility 1. In this paper we report the results of flat beam compression study in a magnetic chicane at an energy E ~ 32 MeV. Additionally, we investigate the effect of energy chirp in the round-to-flat beam transform. The experimental results are compared with numerical simulations.
NASA Technical Reports Server (NTRS)
Norwood, L. B.
1972-01-01
Procedures for low cost fabrication and direct bond installation of flat, single curved, and compound curvature ablative heat shields on a DC-3 aircraft are discussed. The panel sizes and attachment locations are identified. In addition to the bonding of the four contoured panels, two flat panels were bonded to the nearly flat, lower surface of the center wing section. The detailed requirements and objectives of the investigation are described.
2007-01-01
to the formation and preservation of sedimentary strata in the seabed. The goal of the tidal-flats project during the first year was to help plan ...publish the STRATAFORM Master Volume (results are summarized under Work Completed); and 3) help with planning the Tidal Flats DRI (results are... Plan (White Paper), negotiating with Korean scientists about a modified study in Korea, and helping to identify and explore US tidal flats for
Rouchaud, Aymeric; Pistocchi, Silvia; Blanc, Raphaël; Engrand, Nicolas; Bartolini, Bruno; Piotin, Michel
2014-03-01
Haemorrhagic transformations are pejorative for patients with acute ischaemic stroke (AIS). We estimated flat-panel CT performances to detect brain parenchymal hyperdense lesions immediately after mechanical thrombectomy directly on the angiography table in patients with AIS, and its ability to predict haemorrhagic transformation. We also evaluated an easy-reading protocol for post-procedure flat-panel CT evaluation by clinicians to enable them to determine the potential risk of haemorrhage. Two neuroradiologists retrospectively reviewed post-procedural flat-panel CT and 24 h follow-up imaging. We evaluated hyperdense lesions on flat-panel CT to predict the occurrence of haemorrhagic transformation within 24 h detected with conventional imaging. Of 63 patients, 60.3% presented post-procedural parenchymal hyperdensity and 54.0% had haemorrhagic transformation. Significantly more patients with hyperdense lesions on post-thrombectomy flat-panel CT presented haemorrhagic transformation (84.2% vs 8.0%; p<0.0001). No significant haemorrhagic transformations were detected for patients without parenchymal hyperdensity. Sensitivity and specificity of hyperdense lesions on flat-panel CT for the prediction of haemorrhagic transformation were 94.1% (80.3-99.3%) and 79.3% (60.3-92.0%), respectively. The positive and negative predictive values for the occurrence of haemorrhage were 84.2% (68.8-94.0%) and 92.0% (74.0-99.0%), respectively. For significant parenchymal haemorrhage type 2, sensitivity and negative predictive values were 100%. We observed good homogeneity between the different readers. Hyperdensity on post-procedural flat-panel CT was associated with a tendency for higher risk of death and lower risk of good clinical outcome. Flat-panel CT appears to be a good tool to detect brain parenchymal hyperdensities after mechanical thrombectomy in patients with AIS and to predict haemorrhagic transformation.
Constraints on Non-flat Cosmologies with Massive Neutrinos after Planck 2015
NASA Astrophysics Data System (ADS)
Chen, Yun; Ratra, Bharat; Biesiada, Marek; Li, Song; Zhu, Zong-Hong
2016-10-01
We investigate two dark energy cosmological models (I.e., the ΛCDM and ϕCDM models) with massive neutrinos assuming two different neutrino mass hierarchies in both the spatially flat and non-flat scenarios, where in the ϕCDM model the scalar field possesses an inverse power-law potential, V(ϕ) ∝ ϕ -α (α > 0). Cosmic microwave background data from Planck 2015, baryon acoustic oscillation data from 6dFGS, SDSS-MGS, BOSS-LOWZ and BOSS CMASS-DR11, the joint light-curve analysis compilation of SNe Ia apparent magnitude observations, and the Hubble Space Telescope H 0 prior, are jointly employed to constrain the model parameters. We first determine constraints assuming three species of degenerate massive neutrinos. In the spatially flat (non-flat) ΛCDM model, the sum of neutrino masses is bounded as Σm ν < 0.165(0.299) eV at 95% confidence level (CL). Correspondingly, in the flat (non-flat) ϕCDM model, we find Σm ν < 0.164(0.301) eV at 95% CL. The inclusion of spatial curvature as a free parameter results in a significant broadening of confidence regions for Σm ν and other parameters. In the scenario where the total neutrino mass is dominated by the heaviest neutrino mass eigenstate, we obtain similar conclusions to those obtained in the degenerate neutrino mass scenario. In addition, the results show that the bounds on Σm ν based on two different neutrino mass hierarchies have insignificant differences in the spatially flat case for both the ΛCDM and ϕCDM models; however, the corresponding differences are larger in the non-flat case.
On the role of subducting oceanic plateaus in the development of shallow flat subduction
NASA Astrophysics Data System (ADS)
van Hunen, Jeroen; van den Berg, Arie P.; Vlaar, Nico J.
2002-08-01
Oceanic plateaus, aseismic ridges or seamount chains all have a thickened crust and their subduction has been proposed as a possible mechanism to explain the occurrence of flat subduction and related absence of arc magmatism below Peru, Central Chile and at the Nankai Trough (Japan). Their extra compositional buoyancy could prohibit the slab from sinking into the mantle. With a numerical thermochemical convection model, we simulated the subduction of an oceanic lithosphere that contains an oceanic crustal plateau of 18-km thickness. With a systematic variation, we examined the required physical parameters to obtain shallow flat subduction. Metastability of the basaltic crust in the eclogite stability field is of crucial importance for the slab to remain buoyant throughout the subduction process. In a 44-Ma-old subducting plate, basalt must be able to survive a temperature of 600-700 °C to keep the plate buoyant sufficiently long to cause a flat-slab segment. We found that the maximum yield stress in the slab must be limited to about 600 MPa to allow for the necessary bending to the horizontal. Young slabs show flat subduction for larger parameter ranges than old slabs, since they are less gravitationally unstable and show less resistance against bending. Hydrous weakening of the mantle wedge area and lowermost continent are required to allow for the necessary deformation of a change in subduction style from steep to flat. The maximum flat slab extent is about 300 km, which is sufficient to explain the observed shallow flat subduction near the Nankai Trough (Japan). However, additional mechanisms, such as active overthrusting by an overriding continental plate, need to be invoked to explain the flat-slab segments up to 500 km long below Peru and Central Chile.
Responses of water environment to tidal flat reduction in Xiangshan Bay: Part I hydrodynamics
NASA Astrophysics Data System (ADS)
Li, Li; Guan, Weibing; Hu, Jianyu; Cheng, Peng; Wang, Xiao Hua
2018-06-01
Xiangshan Bay consists of a deep tidal channel and three shallow inlets. A large-scale tidal flat has been utilized through coastal construction. To ascertain the accumulate influences of these engineering projects upon the tidal dynamics of the channel-inlets system, this study uses FVCOM to investigate the tides and flow asymmetries of the bay, and numerically simulate the long-term variations of tidal dynamics caused by the loss of tidal flats. It was found that the reduction of tidal flat areas from 1963 to 2010 slightly dampened M2 tidal amplitudes (0.1 m, ∼6%) and advanced its phases by reducing shoaling effects, while amplified M4 tidal amplitudes (0.09 m, ∼27%) and advanced its phases by reducing bottom friction, in the inner bay. Consequently, the ebb dominance was dampened indicated by reduced absolute value of elevation skewness (∼20%) in the bay. The tides and tidal asymmetry were impacted by the locations, areas and slopes of the tidal flats through changing tidal prism, shoaling effect and bottom friction, and consequently impacted tidal duration asymmetry in the bay. Tides and tidal asymmetry were more sensitive to the tidal flat at the head of the bay than the side bank. Reduced/increased tidal flat slopes around the Tie inlet dampened the ebb dominance. Tidal flat had a role in dissipating the M4 tide rather than generating it, while the advection only play a secondary role in generating the M4 tide. The full-length tidal flats reclamation would trigger the reverse of ebb to flood dominance in the bay. This study would be applicable for similar narrow bays worldwide.
Presto, M.K.; Ogston, A.S.; Storlazzi, C.D.; Field, M.E.
2006-01-01
A multi-year study was conducted on a shallow fringing reef flat on Molokai, Hawaii to determine the temporal and spatial dispersal patterns of terrigenous suspended sediment. During this study, trade-wind conditions existed for the majority of the year on the reef flat. The trade-wind conditions produced strong currents and resuspended moderate amounts of sediment on the reef flat on a daily basis during the year of study, resulting in an overwhelming contribution to the total sediment flux. The magnitude and direction of the trade winds relative to the orientation of the coastline, the shallow-relief and broad morphology, and tidal elevation, provided the primary control of the physical processes that resuspended and transported sediment on the reef flat over the period of record. Spatial data indicate that much of the terrigenous sediment resuspended on the reef flat is transported predominantly alongshore and is confined to the inner- to mid-reef flat. Evidence for the limited across-shore mixing and transport is provided by the dominantly alongshore wind-driven currents during trade-wind conditions and the well-defined across-shore gradient in percentage calcium carbonate of the suspended sediment. Regions of slightly offshore suspended-sediment transport along the reef flat can be attributed to the circulation pattern set up by the interaction between the trade winds, coastal morphology, and anthropogenic coastal structures (i.e., fish ponds and wharf). The regions in which sediment were seen to move offshore provide the strongest link between the sediment dynamics on reef flat and fore reef, and qualitatively appears to be correlated with low coral coverage on the fore reef. ?? 2005 Elsevier Ltd. All rights reserved.
Flat spectrum multicomponent radio sources - Cosmic conspiracy or geometry
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pacholczyk, A.G.
1981-01-01
Compact radio sources which do not exhibit currently large flux density variations, are often characterized by spectra nearly flat over a wide range of wavelengths. Cotton et al. (1980) recently reported the results of the VLBI multifrequency interferometric and total flux density observations of a typical representative of the flat spectrum class of sources, a BL Lacertae object PKS 0735+178. If 0735+178 is indeed representative of flat spectrum sources, then some mechanism causing the component production and energy loss to be balanced must be operative among this type of radio source to maintain a flat spectrum over at least certainmore » periods of time. This effect is referred to as 'cosmic conspiracy'. It is suggested that the flatness of spectra of this class of radio sources may be related to a specific symmetry in the radio structure, namely, to a predominantly linear, one-dimensional evolution of radio radiating material, rather than spherical, three-dimensional evolution.« less
Friendly vertical housing: case of walk-up flat housing development in Yogyakarta
NASA Astrophysics Data System (ADS)
Fosterharoldas Swasto, Deva
2018-03-01
In Yogyakarta Province, the local government have developed walk-up flats housing for more than ten years since the mid of the 2000s. Yogyakarta City and Sleman Regency was pioneering the construction with some blocks of flats in several locations. However, after this period, there is limited evaluation about the effectiveness of the occupancy. One of the issues is related to the sustainable housing development. Concerning this situation, it is proposed to examine how the development of walk-up flats housing in Yogyakarta City and Sleman Regency can be evaluated based on specific housing indicator, as a part of sustainable housing development concept. This paper would like to explore the phenomenon on how ‘friendly’ the flats is. The researcher will qualitatively asses variables from the walk-up flat cases in Yogyakarta City and Sleman Regency. The results suggested that the physical quality of the vertical housing situation could be enhanced to meet residents’ satisfaction.
Flat inferior vena cava: indicator of poor prognosis in trauma and acute care surgery patients.
Ferrada, Paula; Vanguri, Poornima; Anand, Rahul J; Whelan, James; Duane, Therese; Wolfe, Luke; Ivatury, Rao
2012-12-01
Flat inferior vena cava (IVC) on ultrasound examination has been shown to correlate with hypovolemic status. We hypothesize that a flat IVC on limited echocardiogram (LTTE) performed in the emergency room (ER) correlates with poor prognosis in acutely ill surgical patients. We conducted a retrospective review of all patients undergoing LTTE in the ER from September 2010 until June 2011. IVC diameter was estimated by subxiphoid window. Flat IVC was defined as diameter less than 2 cm. Fat IVC was defined as diameter greater than 2 cm. Need for intensive care unit admission, blood transfusion requirement, mortality, and need for emergent operation between patients with flat versus Fat IVC were compared. One hundred one hypotensive patients had LTTE performed in the ER. Average age was 38 years. Admission diagnosis was blunt trauma (n = 80), penetrating trauma (n = 13), acute care surgery pathology (n = 7), and burn (n = 1). Seventy-four patients had flat IVC on initial LTTE. Compared with those with fat IVC, flat patients were found have higher rates of intensive care unit admission (51.3 vs 14.8%; P = 0.001), blood transfusion requirement (12.2 vs 3.7%), and mortality (13.5 vs 3.7%). This population also underwent emergent surgery on hospital Day 1 more often (16.2 vs 0%; P = 0.033). Initial flat IVC on LTTE is an indicator of hypovolemia and a predictor of poor outcome.
Jang, Kee-Taek; Ahn, Sangjeong
2016-05-01
-The identification of a precursor lesion is important to understanding the histopathologic and genetic alterations in carcinogenesis. There are a plethora of terminologies that describe precursor lesions of the pancreatobiliary tract, ampulla of Vater, and gallbladder. The current terminologies for precursor lesions may make it difficult to understand the tumor biology. Here, we propose the concept of tumoral and flat intraepithelial neoplasia to improve our understanding of precursor lesions of many epithelial organs, including the pancreatobiliary tract, ampulla of Vater, and gallbladder. -To understand the dichotomous pattern of tumoral and flat intraepithelial neoplasia in carcinogenesis of pancreatobiliary tract, ampulla of Vater, and gallbladder. -Review of relevant literatures indexed in PubMed. -Tumoral intraepithelial neoplasia presents as an intraluminal or intraductal, mass-forming, polypoid lesion or a macroscopic, visible, cystic lesion without intracystic papillae. Microscopically, tumoral intraepithelial neoplasia shows various proportions of papillary and tubular architecture, often with a mixed pattern, such as papillary, tubular, and papillary-tubular. The malignant potential depends on the degree of dysplasia and the cell phenotype of the epithelium. Flat intraepithelial neoplasia presents as a flat or superficial, spreading, mucosal lesion that is frequently accompanied by an invasive carcinoma. Tumoral and flat intraepithelial neoplasias are not homogeneous entities and may exhibit histopathologic spectrum changes and different genetic profiles. Although intraepithelial neoplasia showed a dichotomous pattern in the tumoral versus flat types, they can coexist. Tumoral and flat intraepithelial neoplasia can be interpreted as part of a spectrum of changes in the carcinogenesis pathway of each organ.
Sakamoto, Takashi; Mitsuzaki, Katsuhiko; Utsunomiya, Daisuke; Matsuda, Katsuhiko; Yamamura, Sadahiro; Urata, Joji; Kawakami, Megumi; Yamashita, Yasuyuki
2012-09-01
Although the screening of small, flat polyps is clinically important, the role of CT colonography (CTC) screening in their detection has not been thoroughly investigated. To evaluate the detection capability and usefulness of CTC in the screening of flat and polypoid lesions by comparing CTC with optic colonoscopy findings as the gold standard. We evaluated the CTC detection capability for flat colorectal polyps with a flat surface and a height not exceeding 3 mm (n = 42) by comparing to conventional polypoid lesions (n = 418) according to the polyp diameter. Four types of reconstruction images including multiplanar reconstruction, volume rendering, virtual gross pathology, and virtual endoscopic images were used for visual analysis. We compared the abilities of the four reconstructions for polyp visualization. Detection sensitivity for flat polyps was 31.3%, 44.4%, and 87.5% for lesions measuring 2-3 mm, 4-5 mm, and ≥6 mm, respectively; the corresponding sensitivity for polypoid lesions was 47.6%, 79.0%, and 91.7%. The overall sensitivity for flat lesions (47.6%) was significantly lower than polypoid lesions (64.1%). Virtual endoscopic imaging showed best visualization among the four reconstructions. Colon cancers were detected in eight patients by optic colonoscopy, and CTC detected colon cancers in all eight patients. CTC using 64-row multidetector CT is useful for colon cancer screening to detect colorectal polyps while the detection of small, flat lesions is still challenging.
A dynamic wheel-rail impact analysis of railway track under wheel flat by finite element analysis
NASA Astrophysics Data System (ADS)
Bian, Jian; Gu, Yuantong; Murray, Martin Howard
2013-06-01
Wheel-rail interaction is one of the most important research topics in railway engineering. It involves track impact response, track vibration and track safety. Track structure failures caused by wheel-rail impact forces can lead to significant economic loss for track owners through damage to rails and to the sleepers beneath. Wheel-rail impact forces occur because of imperfections in the wheels or rails such as wheel flats, irregular wheel profiles, rail corrugations and differences in the heights of rails connected at a welded joint. A wheel flat can cause a large dynamic impact force as well as a forced vibration with a high frequency, which can cause damage to the track structure. In the present work, a three-dimensional finite element (FE) model for the impact analysis induced by the wheel flat is developed by the use of the FE analysis (FEA) software package ANSYS and validated by another validated simulation. The effect of wheel flats on impact forces is thoroughly investigated. It is found that the presence of a wheel flat will significantly increase the dynamic impact force on both rail and sleeper. The impact force will monotonically increase with the size of wheel flats. The relationships between the impact force and the wheel flat size are explored from this FEA and they are important for track engineers to improve their understanding of the design and maintenance of the track system.
Tatsumoto, Hideki; Ishii, Yuichi; Machida, Motoi; Taki, Kazuo
2004-05-11
An artificial tidal flat was prepared for the mitigation tool on coastal environment. However, it is considered that most of the flat was not restored to the sufficient amenities for aquatic living things, migratory birds, etc. because none of the ecological mechanisms were understood or planned for. It is therefore investigated in this paper that historical transition factors in ecosystem structure are selected and traced with the diffusion of a public sewerage system, and with environmental factors such as water quality, sediment condition, and aquatic producers in the Yatsu Tidal Flat. As a result, it can be defined that the tidal flat, just like a lagoon, was formed artificially with reclamation and development of its circumference at the first step of transition; the water quality and sediment condition gradually became brackish water and muddy sediment conditions, interactively. The ecosystem pyramid forming orderly layers according to trophic level appeared as a high-bio-production potential in its tidal flat. In the second step, i.e., in recent years, the characteristics of water quality and sediment conditions evolved into a foreshore tidal flat, namely, conditions in the flat observed were that the progression of water included a high concentration of chloride ion as seawater and sediment conditions became sandy. Because of that, the inflowing fresh water and organic mater from the land area decreased with the improvement of the public sewerage system. The ecosystem pyramid was distorted into a chaos pyramid, with inversion of Ulva spp.
78 FR 26110 - Kicking Cars and Going Between Rolling Equipment During Flat Switching Operations
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-03
... Cars and Going Between Rolling Equipment During Flat Switching Operations AGENCY: Federal Railroad... occurred during a railroad switching operation that involved a railroad employee kicking cars and... make recommendations to railroads regarding the adoption of car-handling procedures during flat...
Observing Flat Birds and Other Fun Birding Activities for K-12 Students.
ERIC Educational Resources Information Center
Matthews, Catherine E.; Connors, John
2002-01-01
Introduces the concept of the flat bird, which is a life-size color cutout of a bird, and uses flat birds to introduce the study of birds. Includes suggestions for teaching about common characteristics of birds and information on resource materials. (YDS)
78 FR 40196 - National Environmental Policy Act; Sounding Rockets Program; Poker Flat Research Range
Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-03
...; Sounding Rockets Program; Poker Flat Research Range AGENCY: National Aeronautics and Space Administration... Sounding Rockets Program (SRP) at Poker Flat Research Range (PFRR), Alaska. SUMMARY: Pursuant to the... government agencies, and educational institutions have conducted suborbital rocket launches from the PFRR...
Poker Flats Mine - Div. of Mining, Land, and Water
Lands Coal Regulatory Program Large Mine Permits Mineral Property and Rights Mining Index Land Fishery Water Resources Factsheets Forms banner image of landscape Poker Flats Mine Home Mining Coal Regulatory Program Poker Flats Mine Mining Coal Regulatory Program Info Chickaloon Chuit Watershed Chuitna
75 FR 23642 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-04
... Flat River Approximately 375 feet None +683 City of Desloge, City downstream of the of Park Hills... confluence with Flat of St. Francois Creek. County. Approximately 2,000 None +767 feet upstream of City of... of the St. Francois County. confluence with the Flat River. Approximately 7,000 None +783 feet...
NASA Technical Reports Server (NTRS)
Hsu, J.-C.; Ritchie, C. E.
1992-01-01
An algorithm developed by the WFPC IDT to generate flat fields from Earth streak exposures is now implemented in STSDAS. We explain in detail how this algorithm works and possible deficiencies. We also present two associated tools which can be used to modify the flat field obtained from the standard procedure.
75 FR 11905 - Yukon Flats National Wildlife Refuge, Fairbanks, AK
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-12
... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R7-R-2009-N282; 70133-1265-0000-U4] Yukon Flats National Wildlife Refuge, Fairbanks, AK AGENCY: U.S. Fish and Wildlife Service, Interior. ACTION: Notice of availability of proposed land exchange Yukon Flats National Wildlife Refuge final...
Flat Panel Displays for Medical Monitoring Systems
2001-10-25
filter prevents light from passing (figure 2). FLAT PANEL DISPLAYS FOR MEDICAL MONITORING SYSTEMS A. Cebrián, J. Millet , I. García Department of...The touch screen is placed over the flat panel display as a filter (figure 10) and allows user interfaces based in direct finger touch (figure 11
77 FR 61642 - National Environmental Policy Act; Sounding Rockets Program; Poker Flat Research Range
Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-10
...; Sounding Rockets Program; Poker Flat Research Range AGENCY: National Aeronautics and Space Administration... Sounding Rockets Program (SRP) at Poker Flat Research Range (PFRR), Alaska. SUMMARY: Pursuant to the... educational institutions have conducted suborbital rocket launches from the PFRR. While the PFRR is owned and...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-28
... Techniques Guidelines for Large Appliance and Metal Furniture; Flat Wood Paneling; Paper, Film, and Foil... appliance and metal furniture; flat wood paneling; and paper, film, and foil surface coating processes. In... Control Techniques Guidelines for Large Appliance and Metal Furniture; Flat Wood Paneling; Paper, Film...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-02
... Flat Wood Paneling Surface Coating Processes AGENCY: Environmental Protection Agency (EPA). ACTION... by EPA's Control Techniques Guidelines (CTG) standards for flat wood paneling surface coating processes. EPA is approving this revision concerning the adoption of the EPA CTG requirements for flat wood...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-14
... Flat Wood Paneling Surface Coating Processes AGENCY: Environmental Protection Agency (EPA). ACTION... sources covered by EPA's Control Techniques Guidelines (CTG) standards for flat wood paneling surface... Protection (PADEP) submitted to EPA a SIP revision concerning the adoption of the CTG for flat wood paneling...
75 FR 68394 - Small Business Size Standards: Waiver of the Nonmanufacturer Rule
Federal Register 2010, 2011, 2012, 2013, 2014
2010-11-05
... Woven and Knit impregnated with Flat Dipped Rubber/Plastic Gloves. SUMMARY: The U. S. Small Business... Flat Dipped Rubber/Plastic Gloves, under North American Industry Classification System (NAICS) code... Rule for Woven and Knit impregnated with Flat Dipped Rubber/Plastic Gloves under PSC 9999...
5 CFR 532.279 - Special wage schedules for printing positions.
Code of Federal Regulations, 2011 CFR
2011-01-01
... Opaquer 4 Offset Press Helper 5 Bindery Machine Operator (Helper) 5 Film Assembler-Stripper (Single Flat-Single Color) 5 Platemaker (Single Color) 5 Film Assembler-Stripper (Partial and Composite Flats) 7... Cutter) 8 Bindery Machine Operator (Power Folder) 8 Film Assembler-Stripper (Multiple Flat-Multiple Color...
5 CFR 532.279 - Special wage schedules for printing positions.
Code of Federal Regulations, 2012 CFR
2012-01-01
... Opaquer 4 Offset Press Helper 5 Bindery Machine Operator (Helper) 5 Film Assembler-Stripper (Single Flat-Single Color) 5 Platemaker (Single Color) 5 Film Assembler-Stripper (Partial and Composite Flats) 7... Cutter) 8 Bindery Machine Operator (Power Folder) 8 Film Assembler-Stripper (Multiple Flat-Multiple Color...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-22
... DEPARTMENT OF COMMERCE International Trade Administration (A-580-816) Certain Corrosion-Resistant... results of the antidumping duty administrative review for certain corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea (Korea). See Certain Corrosion-Resistant Carbon Steel Flat...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-21
... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Certain Corrosion-Resistant... results of the antidumping duty administrative review for certain corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea (Korea). See Certain Corrosion-Resistant Carbon Steel Flat...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-11-19
... Memorandum 1. Background 2. Scope of the Investigation 3. Respondent Selection 4. Discussion of Methodology a...: Scope of the Investigation The diffusion-annealed, nickel-plated flat-rolled steel products included in this investigation are flat-rolled, cold-reduced steel products, regardless of chemistry; whether or...
Three-flat test with plates in horizontal posture
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vannoni, Maurizio; Molesini, Giuseppe
2008-04-20
Measuring flats in the horizontal posture with interferometers is analyzed in detail, taking into account the sag produced by gravity. A mathematical expression of the bending is provided for a plate supported at three unevenly spaced locations along the edge. It is shown that the azimuthal terms of the deformation can be recovered from a three-flat measuring procedure, while the pure radial terms can only be estimated. The effectiveness of the iterative algorithm for data processing is also demonstrated. Experimental comparison on a set of three flats in horizontal and upright posture is provided.
Propagation of flat-topped multi-Gaussian beams through a double-lens system with apertures.
Gao, Yanqi; Zhu, Baoqiang; Liu, Daizhong; Lin, Zunqi
2009-07-20
A general model for different apertures and flat-topped laser beams based on the multi-Gaussian function is developed. The general analytical expression for the propagation of a flat-topped beam through a general double-lens system with apertures is derived using the above model. Then, the propagation characteristics of the flat-topped beam through a spatial filter are investigated by using a simplified analytical expression. Based on the Fluence beam contrast and the Fill factor, the influences of a pinhole size on the propagation of the flat-topped multi-Gaussian beam (FMGB) through the spatial filter are illustrated. An analytical expression for the propagation of the FMGB through the spatial filter with a misaligned pinhole is presented, and the influences of the pinhole offset are evaluated.
Effects of thread interruptions on tool pins in friction stir welding of AA6061
Reza-E-Rabby, Md.; Tang, Wei; Reynolds, Anthony P.
2017-06-21
In this paper, effects of pin thread and thread interruptions (flats) on weld quality and process response parameters during friction stir welding (FSW) of 6061 aluminium alloy were quantified. Otherwise, identical smooth and threaded pins with zero to four flats were adopted for FSW. Weldability and process response variables were examined. Results showed that threads with flats significantly improved weld quality and reduced in-plane forces. A three-flat threaded pin led to production of defect-free welds under all examined welding conditions. Spectral analyses of in-plane forces and weld cross-sectional analysis were performed to establish correlation among pin flats, force dynamics andmore » defect formation. Finally, the lowest in-plane force spectra amplitudes were consistently observed for defect-free welds.« less
Effects of thread interruptions on tool pins in friction stir welding of AA6061
DOE Office of Scientific and Technical Information (OSTI.GOV)
Reza-E-Rabby, Md.; Tang, Wei; Reynolds, Anthony P.
In this paper, effects of pin thread and thread interruptions (flats) on weld quality and process response parameters during friction stir welding (FSW) of 6061 aluminium alloy were quantified. Otherwise, identical smooth and threaded pins with zero to four flats were adopted for FSW. Weldability and process response variables were examined. Results showed that threads with flats significantly improved weld quality and reduced in-plane forces. A three-flat threaded pin led to production of defect-free welds under all examined welding conditions. Spectral analyses of in-plane forces and weld cross-sectional analysis were performed to establish correlation among pin flats, force dynamics andmore » defect formation. Finally, the lowest in-plane force spectra amplitudes were consistently observed for defect-free welds.« less
Noël, Jean-Christophe; Buxant, Frédéric; Engohan-Aloghe, Corinne
2010-12-01
The entity of pure flat epithelial atypia remains a challenge due to controversy of the surgical management of residual microcalcifications after core needle biopsies. This study aims to assess the morphological data observed in immediate surgical resection specimen of residual microcalcifications after a diagnosis of pure flat epithelial atypia on mammotome core biopsy. Sixty-two mammotome core biopsy with a diagnosis of pure flat epithelial atypia (flat epithelial atypia without associated atypical ductal hyperplasia, in situ and/or invasive carcinoma) were identified. From these 62 cases, 20 presented residual microcalcifications and underwent an immediate surgical excision after mammotome. Of the 20 patients with excised microcalcifications, 8 (40%)cases had residual pure flat epithelial atypia, 4 (20%) cases had atypical ductal hyperplasia, 4 (20%) cases had lobular in situ neoplasia, no lesions were retrieved in 4 (20%) case. None of the patients had either in situ ductal carcinoma and/or invasive carcinoma. Surgical resection of residual microcalcifications after the diagnosis of pure flat epithelial atypia on core needle biopsy remains still a debate. The present study shows no cases of in situ ductal and/or invasive carcinoma on immediate excision of residual microcalcifications after mammotome core biopsies. Copyright © 2009 Elsevier Ltd. All rights reserved.
Capturing the Flatness of a peer-to-peer lending network through random and selected perturbations
NASA Astrophysics Data System (ADS)
Karampourniotis, Panagiotis D.; Singh, Pramesh; Uparna, Jayaram; Horvat, Emoke-Agnes; Szymanski, Boleslaw K.; Korniss, Gyorgy; Bakdash, Jonathan Z.; Uzzi, Brian
Null models are established tools that have been used in network analysis to uncover various structural patterns. They quantify the deviance of an observed network measure to that given by the null model. We construct a null model for weighted, directed networks to identify biased links (carrying significantly different weights than expected according to the null model) and thus quantify the flatness of the system. Using this model, we study the flatness of Kiva, a large international crownfinancing network of borrowers and lenders, aggregated to the country level. The dataset spans the years from 2006 to 2013. Our longitudinal analysis shows that flatness of the system is reducing over time, meaning the proportion of biased inter-country links is growing. We extend our analysis by testing the robustness of the flatness of the network in perturbations on the links' weights or the nodes themselves. Examples of such perturbations are event shocks (e.g. erecting walls) or regulatory shocks (e.g. Brexit). We find that flatness is unaffected by random shocks, but changes after shocks target links with a large weight or bias. The methods we use to capture the flatness are based on analytics, simulations, and numerical computations using Shannon's maximum entropy. Supported by ARL NS-CTA.
Validation of Heat Transfer and Film Cooling Capabilities of the 3-D RANS Code TURBO
NASA Technical Reports Server (NTRS)
Shyam, Vikram; Ameri, Ali; Chen, Jen-Ping
2010-01-01
The capabilities of the 3-D unsteady RANS code TURBO have been extended to include heat transfer and film cooling applications. The results of simulations performed with the modified code are compared to experiment and to theory, where applicable. Wilcox s k-turbulence model has been implemented to close the RANS equations. Two simulations are conducted: (1) flow over a flat plate and (2) flow over an adiabatic flat plate cooled by one hole inclined at 35 to the free stream. For (1) agreement with theory is found to be excellent for heat transfer, represented by local Nusselt number, and quite good for momentum, as represented by the local skin friction coefficient. This report compares the local skin friction coefficients and Nusselt numbers on a flat plate obtained using Wilcox's k-model with the theory of Blasius. The study looks at laminar and turbulent flows over an adiabatic flat plate and over an isothermal flat plate for two different wall temperatures. It is shown that TURBO is able to accurately predict heat transfer on a flat plate. For (2) TURBO shows good qualitative agreement with film cooling experiments performed on a flat plate with one cooling hole. Quantitatively, film effectiveness is under predicted downstream of the hole.
On the Ck-embedding of Lorentzian manifolds in Ricci-flat spaces
NASA Astrophysics Data System (ADS)
Avalos, R.; Dahia, F.; Romero, C.
2018-05-01
In this paper, we investigate the problem of non-analytic embeddings of Lorentzian manifolds in Ricci-flat semi-Riemannian spaces. In order to do this, we first review some relevant results in the area and then motivate both the mathematical and physical interests in this problem. We show that any n-dimensional compact Lorentzian manifold (Mn, g), with g in the Sobolev space Hs+3, s >n/2 , admits an isometric embedding in a (2n + 2)-dimensional Ricci-flat semi-Riemannian manifold. The sharpest result available for these types of embeddings, in the general setting, comes as a corollary of Greene's remarkable embedding theorems R. Greene [Mem. Am. Math. Soc. 97, 1 (1970)], which guarantee the embedding of a compact n-dimensional semi-Riemannian manifold into an n(n + 5)-dimensional semi-Euclidean space, thereby guaranteeing the embedding into a Ricci-flat space with the same dimension. The theorem presented here improves this corollary in n2 + 3n - 2 codimensions by replacing the Riemann-flat condition with the Ricci-flat one from the beginning. Finally, we will present a corollary of this theorem, which shows that a compact strip in an n-dimensional globally hyperbolic space-time can be embedded in a (2n + 2)-dimensional Ricci-flat semi-Riemannian manifold.
77 FR 19311 - Endangered Species; Receipt of Applications for Permit
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-30
... Gruidae Sturnidae Species: Jackass penguin (Spheniscus demersus) Dama gazelle (Nanger dama) Applicant... wildlife registration under 50 CFR 17.21(g) for the snow leopard (Uncia uncial), and jackass penguin...
Remotely sensed evidence of the rapid loss of tidal flats in the Yellow Sea
NASA Astrophysics Data System (ADS)
Murray, N. J.; Phinn, S. R.; Clemens, R. S.; Possingham, H.; Fuller, R. A.
2013-12-01
In East Asia's Yellow Sea, intertidal wetlands are the frontline ecosystem protecting a coastal population of more than 150 million people from storms and sea-level rise. Despite widespread coastal change and severe modification of the region's major river systems, the magnitude and distribution of coastal wetland loss remains unquantified. We developed a novel remote sensing method to solve the difficult problem of mapping intertidal wetlands over large areas and mapped the extent of tidal flats, the region's primary coastal ecosystem, over 4000kms of coastline at two time periods: the 1980s and late 2000s. We used a regionally validated tide model to identify Landsat images acquired at high and low tides, allowing the area between the high and low tide waterlines to be mapped by differencing classified land-water images between the two tidal stages. Our analysis of the change in areal extent of tidal flats in the Yellow Sea indicates that of the 545,000 ha present in the 1980s, only 389,000 ha remained three decades later, equating to a net loss of 28% at a mean rate of 1.2 % yr-1. ). Comparing the three countries in our analysis, China lost more tidal flat and at a faster rate (39.8%, 1.8% yr-1) than South Korea (32.2%, 1.6% yr-1), and in North Korea minor gains of tidal flat were recorded at (8.5%, 0.3 yr-1). For the same mapped area, historical maps suggest that tidal flats occupied up to 1.14 million ha in the mid-1950s, equating to a potential net loss of up to 65% over ~50 years. Coastal land reclamation for agriculture, aquaculture and urban development is a major driver of tidal flat loss, particularly in China and South Korea, although region-wide declines in sediment replenishment from rivers is also occurring. To conserve the ecosystem services provided by tidal flats and ensure protection of the region's coastal biodiversity, conservation actions should target protection of tidal flats and encourage collaborative and properly planned development strategies. Tidal flat conversion to agricultural land in Chungcheongnam-do Province, South Korea (1982, 2010). The Landsat MSS and TM images show widespread conversion of tidal flats (left) to agricultural land (right) over two decades.
McJury, M; O'Neill, A; Lawson, M; McGrath, C; Grey, A; Page, W; O'Sullivan, J M
2011-08-01
To improve the integration of MRI with radiotherapy treatment planning, our department fabricated a flat couch top for our MR scanner. Setting up using this couch top meant that the patients were physically higher up in the scanner and, posteriorly, a gap was introduced between the patient and radiofrequency coil. Phantom measurements were performed to assess the quantitative impact on image quality. A phantom was set up with and without the flat couch insert in place, and measurements of image uniformity and signal to noise were made. To assess clinical impact, six patients with pelvic cancer were recruited and scanned on both couch types. The image quality of pairs of scans was assessed by two consultant radiologists. The use of the flat couch insert led to a drop in image signal to noise of approximately 14%. Uniformity in the anteroposterior direction was affected the most, with little change in right-to-left and feet-to-head directions. All six patients were successfully scanned on the flat couch, although one patient had to be positioned with their arms by their sides. The image quality scores showed no statistically significant change between scans with and without the flat couch in place. Although the quantitative performance of the coil is affected by the integration of a flat couch top, there is no discernible deterioration of diagnostic image quality, as assessed by two consultant radiologists. Although the flat couch insert moved patients higher in the bore of the scanner, all patients in the study were successfully scanned.
Stanley, T.M.; Feldmann, R.M.
1998-01-01
The Cambro-Ordovician Deadwood Formation and Aladdin Sandstone represent intertidal and subtidal, nearshore deposystems that contain few well-preserved body fossils, but contain abundant trace fossils. The present study uses the much neglected trace-fossil fauna to describe the diverse paleoenvironments represented in the Deadwood-Aladdin deposystems, and to better understand the environmental conditions that controlled benthic life in the Early Paleozoic. The Deadwood-Aladdin ichnotaxa can be separated into three distinct assemblages based on the changing sedimentologic and hydrodynamic conditions that existed across the Cambro-Ordovician shelf. Trace-fossil assemblages and corresponding lithofacies characteristics indicate that the Deadwood-Aladdin deposystems formed within an intertidal-flat and subtidal-shelf environment. Based on the distribution and numbers of preserved ichnotaxa, the intertidal flat can be subdivided further into an ecologically stressful inner sand-flat environment, and a more normal marine outer sand-flat environment, both of which belong to a mixed, Skolithos-Cruziana softground ichnofacies. The inner sand flat is characterized by low diversity, low numbers, and a general lack of complexly constructed ichnotaxa. Trace fossils common to both assemblages tend to be smaller in the inner flat compared to the outer sand flat. Taphonomic effects, such as substrate type and sediment heterogeneity, also aid in differentiating between the inner and outer sand-flat assemblages. The subtidal shelf environment is categorized in the Cruziana Ichnofacies. Ichnological evidence of periodic tempestite deposition and hardground development within this subtidal regime is manifested by high diversity and low abundance of ichnogenera.
Kinematic analysis of the thoracic limb of healthy dogs during descending stair and ramp exercises.
Kopec, Nadia L; Williams, Jane M; Tabor, Gillian F
2018-01-01
OBJECTIVE To compare the kinematics of the thoracic limb of healthy dogs during descent of stairs and a ramp with those during a trot across a flat surface (control). ANIMALS 8 privately owned dogs. PROCEDURES For each dog, the left thoracic limb was instrumented with 5 anatomic markers to facilitate collection of 2-D kinematic data during each of 3 exercises (descending stairs, descending a ramp, and trotting over a flat surface). The stair exercise consisted of 4 steps with a 35° slope. For the ramp exercise, a solid plank was placed over the steps to create a ramp with a 35° slope. For the flat exercise, dogs were trotted across a flat surface for 2 m. Mean peak extension, peak flexion, and range of movement (ROM) of the shoulder, elbow, and carpal joints were compared among the 3 exercises. RESULTS Mean ROM for the shoulder and elbow joints during the stair exercise were significantly greater than during the flat exercise. Mean peak extension of the elbow joint during the flat exercise was significantly greater than that during both the stair and ramp exercises. Mean peak flexion of the elbow joint during the stair exercise was significantly greater than that during the flat exercise. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that descending stairs may be beneficial for increasing the ROM of the shoulder and elbow joints of dogs. Descending stair exercises may increase elbow joint flexion, whereas flat exercises may be better for targeting elbow joint extension.
Collation of quarterly reports on air flat plate collectors
NASA Technical Reports Server (NTRS)
1977-01-01
The solar 2 air flat plate collectors are described. The development and fabrication of a prototype air flat plate collector subsystem containing 320 square feet of collector area are described. Three instrumented panels were completely assembled with glazing and insulation. Manufacture of the last seven prototype collectors was completed in October 1977.
78 FR 61996 - Combined Notice of Filings #1
Federal Register 2010, 2011, 2012, 2013, 2014
2013-10-10
.../13. Docket Numbers: ER13-2474-000. Applicants: Steele Flats Wind Project, LLC. Description: Steele Flats Wind Project, LLC submits Steele Flats Wind Project, LLC Application for Market-Based Rates to be... Energy Florida, Inc. submits tariff filing per 35.13(a)(2)(iii: OATT Name Change to be effective 7/3/2012...
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2010-10-15
... proceeding of Flat Water Wind Farm, LLC's application for market-based rate authority, with an accompanying... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER11-39-000] Flat Water Wind Farm, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for Blanket...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-07
... DEPARTMENT OF COMMERCE International Trade Administration [C-351-829] Certain Hot-Rolled Flat... Commerce (the Department) published the countervailing duty order on certain hot-rolled flat- rolled carbon-quality steel products from Brazil. See Agreement Suspending the Countervailing Duty Investigation on Hot...
76 FR 37655 - Combined Mailings of Standard Mail and Periodicals Flats
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-28
... Periodicals flats to be made using a minimum of six (6) pieces, as is currently permitted for Periodicals... Regulations to reflect that the Standard Mail service standards apply to all Periodicals flats pieces entered... for Standard Mail of 200 pieces or 50 pounds. Periodicals publications must be authorized or have a...
49 CFR 174.61 - Transport vehicles and freight containers on flat cars.
Code of Federal Regulations, 2013 CFR
2013-10-01
... cars. 174.61 Section 174.61 Transportation Other Regulations Relating to Transportation PIPELINE AND... containers on flat cars. (a) A transport vehicle, freight container, or package containing a hazardous... has fuel or any article classed as a hazardous material may be loaded and transported on a flat car as...
49 CFR 174.61 - Transport vehicles and freight containers on flat cars.
Code of Federal Regulations, 2010 CFR
2010-10-01
... cars. 174.61 Section 174.61 Transportation Other Regulations Relating to Transportation PIPELINE AND... containers on flat cars. (a) A transport vehicle, freight container, or package containing a hazardous... has fuel or any article classed as a hazardous material may be loaded and transported on a flat car as...
49 CFR 174.61 - Transport vehicles and freight containers on flat cars.
Code of Federal Regulations, 2011 CFR
2011-10-01
... cars. 174.61 Section 174.61 Transportation Other Regulations Relating to Transportation PIPELINE AND... containers on flat cars. (a) A transport vehicle, freight container, or package containing a hazardous... has fuel or any article classed as a hazardous material may be loaded and transported on a flat car as...
49 CFR 174.61 - Transport vehicles and freight containers on flat cars.
Code of Federal Regulations, 2014 CFR
2014-10-01
... cars. 174.61 Section 174.61 Transportation Other Regulations Relating to Transportation PIPELINE AND... containers on flat cars. (a) A transport vehicle, freight container, or package containing a hazardous... has fuel or any article classed as a hazardous material may be loaded and transported on a flat car as...
The Flat Tax: Implications for Financing Public Schools.
ERIC Educational Resources Information Center
Rossmiller, Richard A.
The campaign for the 1996 Republican presidential election focused attention on proposals to replace the current federal income tax system with a flat tax. This booklet examines the ramifications of a flat tax for local school funding. Section 1 outlines the criteria for evaluating proposed taxes and the purposes of tax systems. The second section…
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-30
... Steel Flat Products From India: Rescission of Antidumping Duty Administrative Review AGENCY: Import... certain hot- rolled carbon steel flat products from India for the period December 1, 2010, through... Products from India: Customs and Border Protection Data for Selection of Respondents for Individual Review...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-22
... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limit for Preliminary Results of... Register the countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from Korea...
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2012-04-27
... DEPARTMENT OF COMMERCE International Trade Administration [A-428-815, A-580-816] Corrosion...) orders on corrosion-resistant carbon steel flat products (CORE) from Germany and South Korea (Korea..., regarding ``Sunset Reviews of the Antidumping Duty Orders on Corrosion-Resistant Carbon Steel Flat Products...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-09
... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products from the Republic of Korea: Extension of Time Limit for Preliminary Results of... countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from Korea. See Countervailing...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-14
... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limit for Preliminary Results of... Register the countervailing duty order on corrosion-resistant carbon steel flat products (CORE) from Korea...
76 FR 34101 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-10
...] Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia Determinations On...-quality steel products from Russia would be likely to lead to continuation or recurrence of material...) entitled Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil, Japan, and Russia: Investigation...
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2012-09-04
... (Phyciodes cocyta arenacolor), Baking Powder Flat blue butterfly (Euphilotes bernardino minuta), and bleached... crescentspot, Baking Powder Flat blue butterfly, and bleached sandhill skipper or their habitats at any time... Steptoe Valley Phyciodes pascoensis Phyciodes cocyta crescentspot. ssp. arenacolor Baking Powder Flat blue...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-10
... Steel Flat Products From Brazil: Rescission of Countervailing Duty Administrative Review AGENCY: Import... hot- rolled carbon steel flat products (hot-rolled steel) from Brazil for the period January 1, 2009... countervailing duty order on hot-rolled steel from Brazil. See Agreement Suspending the Countervailing Duty...
Forest Landscape Assessment Tool (FLAT): rapid assessment for land management
Lisa Ciecko; David Kimmett; Jesse Saunders; Rachael Katz; Kathleen L. Wolf; Oliver Bazinet; Jeffrey Richardson; Weston Brinkley; Dale J. Blahna
2016-01-01
The Forest Landscape Assessment Tool (FLAT) is a set of procedures and tools used to rapidly determine forest ecological conditions and potential threats. FLAT enables planners and managers to understand baseline conditions, determine and prioritize restoration needs across a landscape system, and conduct ongoing monitoring to achieve land management goals. The rapid...
Flat-plate solar array progress and plans
NASA Technical Reports Server (NTRS)
Callaghan, W. T.
1984-01-01
The results of research into the technology of flat-plate solar arrays undertaken in the Flat-Plate Solar Array Project under the sponsorship of the U.S. Department of Energy are surveyed. Topics examined include Si refinement, ribbon-sheet substrate formation, module process sequences, environmental isolation, module engineering and testing, and photovoltaic-array economics.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-21
... DEPARTMENT OF COMMERCE International Trade Administration [C-533-821] Certain Hot-Rolled Carbon...-rolled carbon steel flat products (HRCS) from India covering the January 1, 2006, through December 31... Certain Hot-Rolled Carbon Steel Flat Products from India: Final Results of Countervailing Duty...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-30
... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limit for the Preliminary Results of...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-20
... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... corrosion-resistant carbon steel flat products (CORE) from the Republic of Korea (Korea) for the period of review (POR) January 1, 2008, through December 31, 2008. See Corrosion-Resistant Carbon Steel Flat...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-10
... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limits for the Preliminary Results of...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-29
.... Scope of the Order Products covered by this order are certain corrosion-resistant carbon steel flat... DEPARTMENT OF COMMERCE International Trade Administration [C-580-818] Corrosion-Resistant Carbon... countervailing duty (CVD) order on corrosion-resistant carbon steel flat products from the Republic of Korea for...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-15
... antidumping duty order on corrosion-resistant carbon steel flat products from the Republic of Korea, covering... DEPARTMENT OF COMMERCE International Trade Administration [A-580-816] Corrosion-Resistant Carbon Steel Flat Products From the Republic of Korea: Extension of Time Limits for the Preliminary Results of...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-15
... DEPARTMENT OF COMMERCE International Trade Administration [A-570-865] Certain Hot-Rolled Carbon... review of the antidumping duty order on certain hot- rolled carbon steel flat products (``hot-rolled...\\ See Notice of Antidumping Duty Order: Certain Hot-Rolled Carbon Steel Flat Products from the People's...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-14
... DEPARTMENT OF COMMERCE International Trade Administration [A-533-820] Certain Hot-Rolled Carbon...'') published the preliminary results of the antidumping duty administrative review for certain hot-rolled carbon steel flat products from India (``Indian Hot-Rolled''). See Certain Hot-Rolled Carbon Steel Flat...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-19
... DEPARTMENT OF COMMERCE International Trade Administration [A-533-820] Certain Hot-Rolled Carbon... review of the antidumping duty order on certain hot- rolled carbon steel flat products from India... Preliminary Results \\2\\ of this review. \\2\\ See Certain Hot-Rolled Carbon Steel Flat Products From India...
NASA Astrophysics Data System (ADS)
Perton, Mathieu; Contreras-Zazueta, Marcial A.; Sánchez-Sesma, Francisco J.
2016-06-01
A new implementation of indirect boundary element method allows simulating the elastic wave propagation in complex configurations made of embedded regions that are homogeneous with irregular boundaries or flat layers. In an older implementation, each layer of a flat layered region would have been treated as a separated homogeneous region without taking into account the flat boundary information. For both types of regions, the scattered field results from fictitious sources positioned along their boundaries. For the homogeneous regions, the fictitious sources emit as in a full-space and the wave field is given by analytical Green's functions. For flat layered regions, fictitious sources emit as in an unbounded flat layered region and the wave field is given by Green's functions obtained from the discrete wavenumber (DWN) method. The new implementation allows then reducing the length of the discretized boundaries but DWN Green's functions require much more computation time than the full-space Green's functions. Several optimization steps are then implemented and commented. Validations are presented for 2-D and 3-D problems. Higher efficiency is achieved in 3-D.
NASA Astrophysics Data System (ADS)
Yoo, Byungjin; Hirata, Katsuhiro; Oonishi, Atsurou
In this study, a coupled analysis method for flat panel speakers driven by giant magnetostrictive material (GMM) based actuator was developed. The sound field produced by a flat panel speaker that is driven by a GMM actuator depends on the vibration of the flat panel, this vibration is a result of magnetostriction property of the GMM. In this case, to predict the sound pressure level (SPL) in the audio-frequency range, it is necessary to take into account not only the magnetostriction property of the GMM but also the effect of eddy current and the vibration characteristics of the actuator and the flat panel. In this paper, a coupled electromagnetic-structural-acoustic analysis method is presented; this method was developed by using the finite element method (FEM). This analysis method is used to predict the performance of a flat panel speaker in the audio-frequency range. The validity of the analysis method is verified by comparing with the measurement results of a prototype speaker.
NASA Technical Reports Server (NTRS)
Fusaro, R. L.
1980-01-01
The tribological properties of polyimide-bonded graphite fluoride films were studied with a pin-on-disk friction apparatus. A 440 C HT stainless steel rider with a 0.95 millimeter diameter flat area was slid against the film in order to achieve a light, closely controlled contact stress. A 1 kilogram load was applied to this flat to give a projected contact stress of 14 megapascals. Two stages of lubrication were operating. In the first stage, the film supported the load and the lubricating mechanism appeared to be the shear of a thin surface layer of the film between the rider and the bulk of the film. The second stage began after the original film was worn away, and the lubricating mechanism appeared to be the shear of very thin lubricant layers between the flat area on the rider and flat plateaus generated on the sandblasted asperities of the metallic substrate. The major difference between the lubricating mechanisms of the hemispherical and flat riders was that the flat wore through the film much more slowly than did the hemisphere.
Computerized Measurement of Negative Symptoms in Schizophrenia
Cohen, Alex S.; Alpert, Murray; Nienow, Tasha M.; Dinzeo, Thomas J.; Docherty, Nancy M.
2008-01-01
Accurate measurement of negative symptoms is crucial for understanding and treating schizophrenia. However, current measurement strategies are reliant on subjective symptom rating scales which often have psychometric and practical limitations. Computerized analysis of patients’ speech offers a sophisticated and objective means of evaluating negative symptoms. The present study examined the feasibility and validity of using widely-available acoustic and lexical-analytic software to measure flat affect, alogia and anhedonia (via positive emotion). These measures were examined in their relationships to clinically-rated negative symptoms and social functioning. Natural speech samples were collected and analyzed for 14 patients with clinically-rated flat affect, 46 patients without flat affect and 19 healthy controls. The computer-based inflection and speech rate measures significantly discriminated patients with flat affect from controls, and the computer-based measure of alogia and negative emotion significantly discriminated the flat and non-flat patients. Both the computer and clinical measures of positive emotion/anhedonia corresponded to functioning impairments. The computerized method of assessing negative symptoms offered a number of advantages over the symptom scale-based approach. PMID:17920078
Communication: Two types of flat-planes conditions in density functional theory.
Yang, Xiaotian Derrick; Patel, Anand H G; Miranda-Quintana, Ramón Alain; Heidar-Zadeh, Farnaz; González-Espinoza, Cristina E; Ayers, Paul W
2016-07-21
Using results from atomic spectroscopy, we show that there are two types of flat-planes conditions. The first type of flat-planes condition occurs when the energy as a function of the number of electrons of each spin, Nα and Nβ, has a derivative discontinuity on a line segment where the number of electrons, Nα + Nβ, is an integer. The second type of flat-planes condition occurs when the energy has a derivative discontinuity on a line segment where the spin polarization, Nα - Nβ, is an integer, but does not have a discontinuity associated with an integer number of electrons. Type 2 flat planes are rare-we observed just 15 type 2 flat-planes conditions out of the 4884 cases we tested-but their mere existence has implications for the design of exchange-correlation energy density functionals. To facilitate the development of functionals that have the correct behavior with respect to both fractional number of electrons and fractional spin polarization, we present a dataset for the chromium atom and its ions that can be used to test new functionals.
NASA Technical Reports Server (NTRS)
Roddy, D. J.
1979-01-01
The geologic and core drilling studies described in the present paper show that the Flynn Creek crater has such distinctive morphological features as a broad flat hummocky floor; large central peak; locally terraced crater walls; uplifted, as well as flat-lying rim segments; and a surrounding ejecta blanket. The major structural features include a shallow depth of total brecciation and excavation as compared with apparent crater diameter; a thin breccia lens underlain by a thin zone of disrupted strata; concentric ring fault zones in inner rim, beneath crater wall, and outer crater floor regions; a large central uplift underlain by a narrow dipping zone of deeply disrupted strata; faulted, folded, brecciated, and fractured rim strata; and uplifted rim strata, which dip away from the crater, and flat-lying rim strata, which terminate as inward dipping rocks.
Monitoring transients in low inductance circuits
Guilford, Richard P.; Rosborough, John R.
1987-01-01
A pair of flat cable transmission lines are monitored for transient current spikes by using a probe connected to a current transformer by a pickup loop and monitoring the output of the current transformer. The approach utilizes a U-shaped pickup probe wherein the pair of flat cable transmission lines are received between the legs of the U-shaped probe. The U-shaped probe is preferably formed of a flat coil conductor adhered to one side of a flexible substrate. On the other side of the flexible substrate there is a copper foil shield. The copper foil shield is connected to one end of the flat conductor coil and connected to one leg of the pickup loop which passes through the current transformer. The other end of the flat conductor coil is connected to the other leg of the pickup loop.
Clinical implementation of photon beam flatness measurements to verify beam quality.
Goodall, Simon; Harding, Nicholas; Simpson, Jake; Alexander, Louise; Morgan, Steve
2015-11-08
This work describes the replacement of Tissue Phantom Ratio (TPR) measurements with beam profile flatness measurements to determine photon beam quality during routine quality assurance (QA) measurements. To achieve this, a relationship was derived between the existing TPR15/5 energy metric and beam flatness, to provide baseline values and clinically relevant tolerances. The beam quality was varied around two nominal beam energy values for four matched Elekta linear accelerators (linacs) by varying the bending magnet currents and reoptimizing the beam. For each adjusted beam quality the TPR15/5 was measured using an ionization chamber and Solid Water phantom. Two metrics of beam flatness were evaluated using two identical commercial ionization chamber arrays. A linear relationship was found between TPR15/5 and both metrics of flatness, for both nominal energies and on all linacs. Baseline diagonal flatness (FDN) values were measured to be 103.0% (ranging from 102.5% to 103.8%) for 6 MV and 102.7% (ranging from 102.6% to 102.8%) for 10 MV across all four linacs. Clinically acceptable tolerances of ± 2% for 6 MV, and ± 3% for 10 MV, were derived to equate to the current TPR15/5 clinical tolerance of ± 0.5%. Small variations in the baseline diagonal flatness values were observed between ionization chamber arrays; however, the rate of change of TPR15/5 with diagonal flatness was found to remain within experimental uncertainty. Measurements of beam flatness were shown to display an increased sensitivity to variations in the beam quality when compared to TPR measurements. This effect is amplified for higher nominal energy photons. The derivation of clinical baselines and associated tolerances has allowed this method to be incorporated into routine QA, streamlining the process whilst also increasing versatility. In addition, the effect of beam adjustment can be observed in real time, allowing increased practicality during corrective and preventive maintenance interventions.
NASA Technical Reports Server (NTRS)
Rumsey, Charles B; Lee, Dorothy B
1958-01-01
Skin-temperature measurements have been made at several locations on a flat-faced cone-cylinder nose which was flight tested on a fivestage rocket-propeller model to a Mach number of 14.64 and a free-stream Reynolds number of 2.0 x 10(exp 6), based on flat-face diameter, at an altitude of 66,300 feet. The copper nose had a 29 deg total-angle conical section which was 1.6 flat-face diameters long. The aerodynamic-heating rates determined from the temperature measurements reached 1,440 Btu/( sec) (sq ft) on the flat face. The heating rates near the center of the flat face agreed well at Mach numbers up to 13.6 with those obtained by a theory for laminar stagnation-point heating in equilibrium dissociated air (Avco Res. Rep. 1). At Mach numbers above 13.6, the heating rates at locations near the center of the flat face became progressively lower than stagnation-point theory and. were 29 percent lower at Mach number 14.6 at the end. of the test. The reason for this behavior of the heating on the central part of the flat face was not determined. Excluding the relatively low heating rates that occurred on the central part of the nose at the highest Mach numbers, the distribution of experimental heating along the innermost 0.79 of the flat-face radius, expressed as a percentage of stagnation-point heating, was in fair agreement with the distribution predicted by laminar theory. At a location of 0.71 radii from the stagnation point, the experimental heating was very near 130 percent of the theoretical stagnation-point rate at Mach numbers from 11 to 14.5. The experimental beating rates on the conical section of the nose were in good agreement with laminar-cone theory using the assumption of theoretical sharp-cone static pressure on the conical section.
Identification of flat dysplastic aberrant crypt foci in the colon of azoxymethane-treated A/J mice.
Paulsen, Jan Erik; Knutsen, Helle; Ølstørn, Hege Benedikte; Løberg, Else Marit; Alexander, Jan
2006-02-01
The role of aberrant crypt foci (ACF) as preneoplastic lesions in colon carcinogenesis is not clear. In Min/+ mice and their wild-type littermates treated with azoxymethane (AOM), we previously identified a subgroup of flat ACF that seem more immediate precursors of tumors than the classical elevated ACF. In the present study, we identified a similar subgroup of flat ACF in AOM-treated A/J mice and compared them with nascent tumors and classical elevated ACF. At week 1 and 2 after birth, A/J mice were injected subcutaneously with AOM (10 mg/kg bw/injection). At weeks 7-14, we examined the luminal surface of unsectioned colon preparations stained with methylene blue in the inverse light microscope. The lesions were also examined by histopathology and immunohistochemistry. Surface examination revealed flat ACF, classical elevated ACF and nascent tumors. Since flat ACF were not observed as elevated structures, their bright blue appearance and compressed pit pattern of crypt openings seen with transillumination were used as criteria for their identification. Flat ACF and nascent tumors displayed a uniform picture of severe dysplasia, compressed pit pattern, overexpression of cytoplasmic/nuclear beta-catenin and nuclear overexpression of cyclin D1. Apparently, flat ACF and tumors represented the same type of dysplastic lesions at different stages of crypt multiplication. In contrast, classical elevated ACF did not seem to be as clearly related to tumorigenesis. They infrequently (1/20) possessed severe dysplasia, overexpression of cytoplasmic/nuclear beta-catenin, or nuclear overexpression of cyclin D1, and they did not have compressed crypt openings. Furthermore, flat ACF grew significantly faster than classical elevated ACF. In conclusion, our data indicate a development from flat ACF to adenoma characterized by aberrant activation of the Wnt signaling pathway and fast crypt multiplication. Classical elevated ACF do not seem to be as closely related to tumorigenesis. Copyright 2005 Wiley-Liss, Inc.
21. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING NORTHWEST. ...
21. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING NORTHWEST. BY THE LATE 1960S, THE SITE HAD UNDERGONE TWO MAJOR EXPANSIONS. THE FIRST EXPANSION IN 1956-57, WHEN THE TRIGGER DESIGN CHANGED AND NECESSITATED THE ADDITION OF SEVEN NEW BUILDINGS. THE SECOND LARGE EXPANSION TOOK PLACE FROM 1964-65, WHEN ROCKY FLATS BECAME THE SOLE PRODUCER OF TRIGGERS. DURING THIS EXPANSION, ELEVEN BUILDINGS WERE ADDED, PRIMARILY IN RESEARCH AND DEVELOPMENT LABORATORIES, GUARD HOUSES, AND WASTE WATER TREATMENT (7/1/69). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bechtel Nevada
2005-09-01
A new, revised three-dimensional (3-D) hydrostratigraphic framework model for Frenchman Flat was completed in 2004. The area of interest includes Frenchman Flat, a former nuclear testing area at the Nevada Test Site, and proximal areas. Internal and external reviews of an earlier (Phase I) Frenchman Flat model recommended additional data collection to address uncertainties. Subsequently, additional data were collected for this Phase II initiative, including five new drill holes and a 3-D seismic survey.
A comparative study of spherical and flat-Earth geopotential modeling at satellite elevations
NASA Technical Reports Server (NTRS)
Parrott, M. H.; Hinze, W. J.; Braile, L. W.
1985-01-01
Flat-Earth and spherical-Earth geopotential modeling of crustal anomaly sources at satellite elevations are compared by computing gravity and scalar magnetic anomalies perpendicular to the strike of variably dimensioned rectangular prisms at altitudes of 150, 300, and 450 km. Results indicate that the error caused by the flat-Earth approximation is less than 10% in most geometric conditions. Generally, error increase with larger and wider anomaly sources at higher altitudes. For most crustal source modeling applications at conventional satellite altitudes, flat-Earth modeling can be justified and is numerically efficient.
Advanced solar box and flat plate collector cookers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Grupp, M.; Bergler, H.
Several new solar cooker systems have been developed at Synopsis during the last years: advanced box type cookers, featuring an optimized heat transfer from the absorber into the cooking vessel; flat plate cookers, based on a particular two-way collector with air as transfer fluid; flat plate cookers with heat-pipe transfer; specialized cookers for the baking of bread and flat bread. The working principle of these cookers is described, the structure of a thermal simulation model and results of thermal tests are presented. The results of the first year of local production and use of advanced boxes in India are reported.
Flat connections in open string mirror symmetry
NASA Astrophysics Data System (ADS)
Alim, Murad; Hecht, Michael; Jockers, Hans; Mayr, Peter; Mertens, Adrian; Soroush, Masoud
2012-06-01
We study a flat connection defined on the open-closed deformation space of open string mirror symmetry for type II compactifications on Calabi-Yau threefolds with D-branes. We use flatness and integrability conditions to define distinguished flat coordinates and the superpotential function at an arbitrary point in the open-closed deformation space. Integrability conditions are given for concrete deformation spaces with several closed and open string deformations. We study explicit examples for expansions around different limit points, including orbifold Gromov-Witten invariants, and brane configurations with several brane moduli. In particular, the latter case covers stacks of parallel branes with non-Abelian symmetry.
Peer-to-peer lending and bias in crowd decision-making
Uparna, Jayaram; Karampourniotis, Panagiotis; Horvat, Emoke-Agnes; Szymanski, Boleslaw; Korniss, Gyorgy; Bakdash, Jonathan Z.; Uzzi, Brian
2018-01-01
Peer-to-peer lending is hypothesized to help equalize economic opportunities for the world’s poor. We empirically investigate the “flat-world” hypothesis, the idea that globalization eventually leads to economic equality, using crowdfinancing data for over 660,000 loans in 220 nations and territories made between 2005 and 2013. Contrary to the flat-world hypothesis, we find that peer-to-peer lending networks are moving away from flatness. Furthermore, decreasing flatness is strongly associated with multiple variables: relatively stable patterns in the difference in the per capita GDP between borrowing and lending nations, ongoing migration flows from borrowing to lending nations worldwide, and the existence of a tie as a historic colonial. Our regression analysis also indicates a spatial preference in lending for geographically proximal borrowers. To estimate the robustness for these patterns for future changes, we construct a network of borrower and lending nations based on the observed data. Then, to perturb the network, we stochastically simulate policy and event shocks (e.g., erecting walls) or regulatory shocks (e.g., Brexit). The simulations project a drift towards rather than away from flatness. However, levels of flatness persist only for randomly distributed shocks. By contrast, loss of the top borrowing nations produces more flatness, not less, indicating how the welfare of the overall system is tied to a few distinctive and critical country–pair relationships. PMID:29590131
NASA Astrophysics Data System (ADS)
Nambu, Ryogen; Saito, Hajime; Tanaka, Yoshio; Higano, Junya; Kuwahara, Hisami
2012-03-01
There are many studies on spatial distributions of Asari clam Ruditapes philippinarum adults on tidal flats but few have dealt with spatial distributions of newly settled Asari clam (<0.3 mm shell length, indicative of settlement patterns) in relation to physical/topographical conditions on tidal flats. We examined small-scale spatial distributions of newly settled individuals on the Matsunase tidal flat, central Japan, during the low spring tides on two days 29th-30th June 2007, together with the shear stress from waves and currents on the flat. The characteristics of spatial distribution of newly settled Asari clam markedly varied depending on both of hydrodynamic and topographical conditions on the tidal flat. Using generalized linear models (GLMs), factors responsible for affecting newly settled Asari clam density and its spatial distribution were distinguished between sampling days, with "crest" sites always having a negative influence each on the density and the distribution on both sampling days. The continuously recorded data for the wave-current flows at the "crest" site on the tidal flat showed that newly settled Asari clam, as well as bottom sediment particles, at the "crest" site to be easily displaced. Small-scale spatial distributions of newly settled Asari clam changed with more advanced benthic stages in relation to the wave shear stress.
Peer-to-peer lending and bias in crowd decision-making.
Singh, Pramesh; Uparna, Jayaram; Karampourniotis, Panagiotis; Horvat, Emoke-Agnes; Szymanski, Boleslaw; Korniss, Gyorgy; Bakdash, Jonathan Z; Uzzi, Brian
2018-01-01
Peer-to-peer lending is hypothesized to help equalize economic opportunities for the world's poor. We empirically investigate the "flat-world" hypothesis, the idea that globalization eventually leads to economic equality, using crowdfinancing data for over 660,000 loans in 220 nations and territories made between 2005 and 2013. Contrary to the flat-world hypothesis, we find that peer-to-peer lending networks are moving away from flatness. Furthermore, decreasing flatness is strongly associated with multiple variables: relatively stable patterns in the difference in the per capita GDP between borrowing and lending nations, ongoing migration flows from borrowing to lending nations worldwide, and the existence of a tie as a historic colonial. Our regression analysis also indicates a spatial preference in lending for geographically proximal borrowers. To estimate the robustness for these patterns for future changes, we construct a network of borrower and lending nations based on the observed data. Then, to perturb the network, we stochastically simulate policy and event shocks (e.g., erecting walls) or regulatory shocks (e.g., Brexit). The simulations project a drift towards rather than away from flatness. However, levels of flatness persist only for randomly distributed shocks. By contrast, loss of the top borrowing nations produces more flatness, not less, indicating how the welfare of the overall system is tied to a few distinctive and critical country-pair relationships.
Zhu, Timothy C; Friedberg, Joseph S; Dimofte, Andrea; Miles, Jeremy; Metz, James; Glatstein, Eli; Hahn, Stephen M
2002-06-06
An isotropic detector-based system was compared with a flat photodiode-based system in patients undergoing pleural photodynamic therapy. Isotropic and flat detectors were placed side by side in the chest cavity, for simultaneous in vivo dosimetry at surface locations for twelve patients. The treatment used 630nm laser to a total light irradiance of 30 J/cm 2 (measured with the flat photodiodes) with photofrin® IV as the photosensitizer. Since the flat detectors were calibrated at 532nm, wavelength correction factors (WCF) were used to convert the calibration to 630nm (WCF between 0.542 and 0.703). The mean ratio between isotropic and flat detectors for all sites was linear to the accumulated fluence and was 3.4±0.6 or 2.1±0.4, with or without the wavelength correction for the flat detectors, respectively. The μ eff of the tissues was estimated to vary between 0.5 to 4.3 cm -1 for four sites (Apex, Posterior Sulcus, Anterior Chest Wall, and Posterior Mediastinum) assuming μ s ' = 7 cm -1 . Insufficient information was available to estimate μ eff directly for three other sites (Anterior Sulcus, Posterior Chest Wall, and Pericardium) primarily due to limited sample size, although one may assume the optical penetration in all sites to vary in the same range (0.5 to 4.3 cm -1 ).
Foreland uplift during flat subduction: Insights from the Peruvian Andes and Fitzcarrald Arch
NASA Astrophysics Data System (ADS)
Bishop, Brandon T.; Beck, Susan L.; Zandt, George; Wagner, Lara S.; Long, Maureen D.; Tavera, Hernando
2018-04-01
Foreland deformation has long been associated with flat-slab subduction, but the precise mechanism linking these two processes remains unclear. One example of foreland deformation corresponding in space and time to flat subduction is the Fitzcarrald Arch, a broad NE-SW trending topographically high feature covering an area of >4 × 105 km2 in the Peruvian Andean foreland. Recent imaging of the southern segment of Peruvian flat slab shows that the shallowest part of the slab, which corresponds to the subducted Nazca Ridge northeast of the present intersection of the ridge and the Peruvian trench, extends up to and partly under the southwestern edge of the arch. Here, we evaluate models for the formation of this foreland arch and find that a basal-shear model is most consistent with observations. We calculate that 5 km of lower crustal thickening would be sufficient to generate the arch's uplift since the late Miocene. This magnitude is consistent with prior observations of unusually thickened crust in the Andes immediately south of the subducted ridge that may also have been induced by flat subduction. This suggests that the Fitzcarrald Arch's formation by the Nazca Ridge may be one of the clearest examples of upper plate deformation induced through basal shear observed in a flat-slab subduction setting. We then explore the more general implications of our results for understanding deformation above flat slabs in the geologic past.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-21
... fully stabilized; high strength low alloy; and the substrate for motor lamination steel may also enter... Steel Flat Products From the People's Republic of China: Final Results and Final No Shipments... antidumping duty order on certain hot- rolled carbon steel flat products (``hot-rolled steel'') from the...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-09
... DEPARTMENT OF COMMERCE International Trade Administration [A-583-835] Certain Hot-Rolled Carbon... order on certain hot-rolled carbon steel flat products from Taiwan. The period of review is November 1... antidumping duty order on certain hot- rolled carbon steel flat products from Taiwan covering the period...
29. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING SOUTH. ...
29. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING SOUTH. IN 1983, THE PERIMETER SECURITY ZONE SURROUNDING THE PLUTONIUM OPERATIONS WAS COMPLETED. IT CONSISTED OF A DOUBLE PERIMETER FENCE, CLOSED CIRCUIT TELEVISIONS, ALARMS, AND AN UNINTERRUPTED POWER SUPPLY (7/29/83). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO
The Fallacies of Flatness: Thomas Friedman's "The World Is Flat"
ERIC Educational Resources Information Center
Abowitz, Kathleen Knight; Roberts, Jay
2007-01-01
Thomas Friedman's best-selling "The World is Flat" has exerted much influence in the west by providing both an accessible analysis of globalization and its economic and social effects, and a powerful cultural metaphor for globalization. In this review, we more closely examine Friedman's notion of the social contract, the moral center of his…
46 CFR 154.1320 - Sighting ports, tubular gauge glasses, and flat plate type gauge glasses.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 46 Shipping 5 2011-10-01 2011-10-01 false Sighting ports, tubular gauge glasses, and flat plate type gauge glasses. 154.1320 Section 154.1320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... glasses, and flat plate type gauge glasses. (a) Cargo tanks may have sighting ports as a secondary means...
46 CFR 154.1320 - Sighting ports, tubular gauge glasses, and flat plate type gauge glasses.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Sighting ports, tubular gauge glasses, and flat plate type gauge glasses. 154.1320 Section 154.1320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... glasses, and flat plate type gauge glasses. (a) Cargo tanks may have sighting ports as a secondary means...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-30
... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-350 and 731-TA-616 and 618 (Third Review)] Corrosion-Resistant Carbon Steel Flat Products From Germany and Korea; Scheduling of Full Five-Year Reviews... corrosion-resistant carbon steel flat products from Korea and the antidumping duty orders on corrosion...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-19
...-Rolled Carbon-Quality Steel Products From Brazil: Correction to Notice of Antidumping Duty Order AGENCY... certain hot-rolled flat-rolled carbon-quality steel products from Brazil. See Antidumping Duty Order: Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, 67 FR 11093 (March 12, 2002...
19 CFR 148.105 - Procedure for excluding articles from flat rate of duty.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 19 Customs Duties 2 2010-04-01 2010-04-01 false Procedure for excluding articles from flat rate of... Importations of Limited Value § 148.105 Procedure for excluding articles from flat rate of duty. (a) Generally... communicate the information in writing to the Commissioner of Customs, Attention: Office of Field Operations...
The World Is Not Flat: Can People Reorient Using Slope?
ERIC Educational Resources Information Center
Nardi, Daniele; Newcombe, Nora S.; Shipley, Thomas F.
2011-01-01
Studies of spatial representation generally focus on flat environments and visual input. However, the world is not flat, and slopes are part of most natural environments. In a series of 4 experiments, we examined whether humans can use a slope as a source of allocentric, directional information for reorientation. A target was hidden in a corner of…
24 CFR 1000.126 - May a recipient charge flat or income-adjusted rents?
Code of Federal Regulations, 2010 CFR
2010-04-01
... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false May a recipient charge flat or income-adjusted rents? 1000.126 Section 1000.126 Housing and Urban Development Regulations Relating to... § 1000.126 May a recipient charge flat or income-adjusted rents? Yes, providing the rental or homebuyer...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-28
... DEPARTMENT OF COMMERCE International Trade Administration [C-533-821] Certain Hot-Rolled Carbon... certain hot-rolled carbon steel flat products (HRCS) from India covering the period of review (POR) of January 1, 2006, through December 31, 2006. See Certain Hot-Rolled Carbon Steel Flat Products from India...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-14
...] Certain Hot-Rolled Carbon Steel Flat Products From India, Indonesia, and Thailand: Final Results of... second sunset reviews of the countervailing duty (``CVD'') orders on certain hot-rolled carbon steel flat...). Scope of the Orders The merchandise subject to these orders is hot-rolled steel of a rectangular shape...
Transport processes in intertidal sand flats
NASA Astrophysics Data System (ADS)
Wu, Christy
2010-05-01
Methane rich sulfate depleted seeps are observed along the low water line of the intertidal sand flat Janssand in the Wadden Sea. It is unclear where in the flat the methane is formed, and how it is transported to the edge of the sand flat where the sulfidic water seeps out. Methane and sulfate distributions in pore water were determined along transects from low water line toward the central area of the sand flat. The resulting profiles showed a zone of methane-rich and sulfate-depleted pore water below 2 m sediment depth. Methane production and sulfate reduction are monitored over time for surface sediments collected from the upper flat and seeping area. Both activities were at 22 C twice as high as at 15 C. The rates in sediments from the central area were higher than in sediments from the methane seeps. Methanogenesis occurred in the presence of sulfate, and was not significantly accelerated when sulfate was depleted. The observations show a rapid anaerobic degradation of organic matter in the Janssand. The methane rich pore water is obviously transported with a unidirectional flow from the central area of the intertidal sand flat toward the low water line. This pore water flow is driven by the pressure head caused by elevation of the pore water relative to the sea surface at low tide (Billerbeck et al. 2006a). The high methane concentration at the low water line accumulates due to a continuous outflow of pore water at the seepage site that prevents penetration of electron acceptors such as oxygen and sulfate to reoxidize the reduced products of anaerobic degradation (de Beer et al. 2006). It is, however, not clear why no methane accumulates or sulfate is depleted in the upper 2 m of the flats.
Flatness-based control in successive loops for stabilization of heart's electrical activity
NASA Astrophysics Data System (ADS)
Rigatos, Gerasimos; Melkikh, Alexey
2016-12-01
The article proposes a new flatness-based control method implemented in successive loops which allows for stabilization of the heart's electrical activity. Heart's pacemaking function is modeled as a set of coupled oscillators which potentially can exhibit chaotic behavior. It is shown that this model satisfies differential flatness properties. Next, the control and stabilization of this model is performed with the use of flatness-based control implemented in cascading loops. By applying a per-row decomposition of the state-space model of the coupled oscillators a set of nonlinear differential equations is obtained. Differential flatness properties are shown to hold for the subsystems associated with the each one of the aforementioned differential equations and next a local flatness-based controller is designed for each subsystem. For the i-th subsystem, state variable xi is chosen to be the flat output and state variable xi+1 is taken to be a virtual control input. Then the value of the virtual control input which eliminates the output tracking error for the i-th subsystem becomes reference setpoint for the i + 1-th subsystem. In this manner the control of the entire state-space model is performed by successive flatness-based control loops. By arriving at the n-th row of the state-space model one computes the control input that can be actually exerted on the aforementioned biosystem. This real control input of the coupled oscillators' system, contains recursively all virtual control inputs associated with the previous n - 1 rows of the state-space model. This control approach achieves asymptotically the elimination of the chaotic oscillation effects and the stabilization of the heart's pulsation rhythm. The stability of the proposed control scheme is proven with the use of Lyapunov analysis.
Storlazzi, C.D.; Ogston, A.S.; Bothner, Michael H.; Field, M.E.; Presto, M.K.
2004-01-01
The fringing coral reef off the south coast of Molokai, Hawaii is currently being studied as part of a US Geological Survey (USGS) multi-disciplinary project that focuses on geologic and oceanographic processes that affect coral reef systems. For this investigation, four instrument packages were deployed across the fringing coral reef during the summer of 2001 to understand the processes governing fine-grained terrestrial sediment suspension on the shallow reef flat (h=1m) and its advection across the reef crest and onto the deeper fore reef. The time-series measurements suggest the following conceptual model of water and fine-grained sediment transport across the reef: Relatively cool, clear water flows up onto the reef flat during flooding tides. At high tide, more deep-water wave energy is able to propagate onto the reef flat and larger Trade wind-driven waves can develop on the reef flat, thereby increasing sediment suspension. Trade wind-driven surface currents and wave breaking at the reef crest cause setup of water on the reef flat, further increasing the water depth and enhancing the development of depth-limited waves and sediment suspension. As the tide ebbs, the water and associated suspended sediment on the reef flat drains off the reef flat and is advected offshore and to the west by Trade wind- and tidally- driven currents. Observations on the fore reef show relatively high turbidity throughout the water column during the ebb tide. It therefore appears that high suspended sediment concentrations on the deeper fore reef, where active coral growth is at a maximum, are dynamically linked to processes on the muddy, shallow reef flat.
Stidd, D A; Theessen, H; Deng, Y; Li, Y; Scholz, B; Rohkohl, C; Jhaveri, M D; Moftakhar, R; Chen, M; Lopes, D K
2014-01-01
Flat panel detector CT images are degraded by streak artifacts caused by radiodense implanted materials such as coils or clips. A new metal artifacts reduction prototype algorithm has been used to minimize these artifacts. The application of this new metal artifacts reduction algorithm was evaluated for flat panel detector CT imaging performed in a routine clinical setting. Flat panel detector CT images were obtained from 59 patients immediately following cerebral endovascular procedures or as surveillance imaging for cerebral endovascular or surgical procedures previously performed. The images were independently evaluated by 7 physicians for metal artifacts reduction on a 3-point scale at 2 locations: immediately adjacent to the metallic implant and 3 cm away from it. The number of visible vessels before and after metal artifacts reduction correction was also evaluated within a 3-cm radius around the metallic implant. The metal artifacts reduction algorithm was applied to the 59 flat panel detector CT datasets without complications. The metal artifacts in the reduction-corrected flat panel detector CT images were significantly reduced in the area immediately adjacent to the implanted metal object (P = .05) and in the area 3 cm away from the metal object (P = .03). The average number of visible vessel segments increased from 4.07 to 5.29 (P = .1235) after application of the metal artifacts reduction algorithm to the flat panel detector CT images. Metal artifacts reduction is an effective method to improve flat panel detector CT images degraded by metal artifacts. Metal artifacts are significantly decreased by the metal artifacts reduction algorithm, and there was a trend toward increased vessel-segment visualization. © 2014 by American Journal of Neuroradiology.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Yun; Ratra, Bharat; Biesiada, Marek
We investigate two dark energy cosmological models (i.e., the ΛCDM and ϕ CDM models) with massive neutrinos assuming two different neutrino mass hierarchies in both the spatially flat and non-flat scenarios, where in the ϕ CDM model the scalar field possesses an inverse power-law potential, V ( ϕ ) ∝ ϕ {sup −} {sup α} ( α > 0). Cosmic microwave background data from Planck 2015, baryon acoustic oscillation data from 6dFGS, SDSS-MGS, BOSS-LOWZ and BOSS CMASS-DR11, the joint light-curve analysis compilation of SNe Ia apparent magnitude observations, and the Hubble Space Telescope H {sub 0} prior, are jointly employedmore » to constrain the model parameters. We first determine constraints assuming three species of degenerate massive neutrinos. In the spatially flat (non-flat) ΛCDM model, the sum of neutrino masses is bounded as Σ m {sub ν} < 0.165(0.299) eV at 95% confidence level (CL). Correspondingly, in the flat (non-flat) ϕ CDM model, we find Σ m {sub ν} < 0.164(0.301) eV at 95% CL. The inclusion of spatial curvature as a free parameter results in a significant broadening of confidence regions for Σ m {sub ν} and other parameters. In the scenario where the total neutrino mass is dominated by the heaviest neutrino mass eigenstate, we obtain similar conclusions to those obtained in the degenerate neutrino mass scenario. In addition, the results show that the bounds on Σ m {sub ν} based on two different neutrino mass hierarchies have insignificant differences in the spatially flat case for both the ΛCDM and ϕ CDM models; however, the corresponding differences are larger in the non-flat case.« less
Sedimentary Facies Mapping Based on Tidal Channel Network and Topographic Features
NASA Astrophysics Data System (ADS)
Ryu, J. H.; Lee, Y. K.; Kim, K.; Kim, B.
2015-12-01
Tidal flats on the west coast of Korea suffer intensive changes in their surface sedimentary facies as a result of the influence of natural and artificial changes. Spatial relationships between surface sedimentary facies distribution and benthic environments were estimated for the open-type Ganghwa tidal flat and semi closed-type Hwangdo tidal flat, Korea. In this study, we standardized the surface sedimentary facies and tidal channel index of the channel density, distance, thickness and order. To extract tidal channel information, we used remotely sensed data, such as those from the Korea Multi-Purpose Satellite (KOMPSAT)-2, KOMPSAT-3, and aerial photographs. Surface sedimentary facies maps were generated based on field data using an interpolation method.The tidal channels in each sediment facies had relatively constant meandering patterns, but the density and complexity were distinguishable. The second fractal dimension was 1.7-1.8 in the mud flat, about 1.4 in the mixed flat, and about 1.3 in the sand flat. The channel density was 0.03-0.06 m/m2 in the mud flat and less than 0.02 m/m2 in the mixed and sand flat areas of the two test areas. Low values of the tidal channel index, which indicated a simple pattern of tidal channel distribution, were identified at areas having low elevation and coarse-grained sediments. By contrast, high values of the tidal channel index, which indicated a dendritic pattern of tidal channel distribution, were identified at areas having high elevation and fine-grained sediments. Surface sediment classification based on remotely sensed data must circumspectly consider an effective critical grain size, water content, local topography, and intertidal structures.
NASA Astrophysics Data System (ADS)
Eakin, Caroline M.; Long, Maureen D.; Wagner, Lara S.; Beck, Susan L.; Tavera, Hernando
2015-02-01
The Peruvian flat slab is by far the largest region of flat subduction in the world today, but aspects of its structure and dynamics remain poorly understood. In particular, questions remain over whether the relatively narrow Nazca Ridge subducting beneath southern Peru provides dynamic support for the flat slab or it is just a passive feature. We investigate the dynamics and interaction of the Nazca Ridge and the flat slab system by studying upper mantle seismic anisotropy across southern Peru. We analyze shear wave splitting of SKS, sSKS, and PKS phases at 49 stations distributed across the area, primarily from the PerU Lithosphere and Slab Experiment (PULSE). We observe distinct spatial variations in anisotropic structure along strike, most notably a sharp transition from coherent splitting in the north to pervasive null (non-split) arrivals in the south, with the transition coinciding with the northern limit of the Nazca Ridge. For both anisotropic domains there is evidence for complex and multi-layered anisotropy. To the north of the ridge our *KS splitting measurements likely reflect trench-normal mantle flow beneath the flat slab. This signal is then modified by shallower anisotropic layers, most likely in the supra-slab mantle, but also potentially from within the slab. To the south the sub-slab mantle is similarly anisotropic, with a trench-oblique fast direction, but widespread nulls appear to reflect dramatic heterogeneity in anisotropic structure above the flat slab. Overall the regional anisotropic structure, and thus the pattern of deformation, appears to be closely tied to the location of the Nazca Ridge, which further suggests that the ridge plays a key role in the mantle dynamics of the Peruvian flat slab system.
Geng, Youfu; Li, Xuejin; Tan, Xiaoling; Deng, Yuanlong; Yu, Yongqin
2013-07-15
In this paper, an in-line comb filter with flat-top spectral response is proposed and constructed based on a cascaded all-solid photonic bandgap fiber modal interferometer. It consists of two short pieces of all-solid photonic bandgap fiber and two standard single-mode fibers as lead fibers with core-offset splices between them. The theoretical and experimental results demonstrated that by employing a cut and resplice process on the central position of all-solid photonic bandgap fiber, the interference spectra are well tailored and flat-top spectral profiles could be realized by the controllable offset amount of the resplice. The channel position also could be tuned by applying longitudinal torsion with up to 4 nm tuning range. Such a flat-top fiber comb filter is easy-to-fabricate and with a designable passband width and flat-top profile.
The dangerous flat spin and the factors affecting it
NASA Technical Reports Server (NTRS)
Fuchs, Richard; Schmidt, Wilhelm
1931-01-01
This report deals first with the fundamental data required for the investigation. These are chiefly the aerodynamic forces and moments acting on an airplane in a flat spin. It is shown that these forces and moments depend principally on the angle of attack and on the rotation about the path axis, and can therefore either be measured in a wind tunnel or calculated from wind-tunnel measurements of lift, drag and moment about the leading edge of the wing of an airplane model at rest. The lift, drag and moments about the span axis are so greatly altered by the rapid rotation in a flat spin, that they can no longer be regarded as independent of rotation. No substantial change in the angles of attack and glide occurring in a flat spin is involved. The cross-wind force, as compared with the lift and drag, can be disregarded in a flat spin.
Universal phase diagrams with superconducting domes for electronic flat bands
NASA Astrophysics Data System (ADS)
Löthman, Tomas; Black-Schaffer, Annica M.
2017-08-01
Condensed matter systems with flat bands close to the Fermi level generally exhibit, due to their very large density of states, extraordinarily high critical ordering temperatures of symmetry-breaking orders, such as superconductivity and magnetism. Here we show that the critical temperatures follow one of two universal curves with doping away from a flat band depending on the ordering channel, which completely dictates both the general order competition and the phase diagram. Notably, we find that orders in the particle-particle channel (superconducting orders) survive decisively farther than orders in the particle-hole channel (magnetic or charge orders) because the channels have fundamentally different polarizabilities. Thus, even if a magnetic or charge order initially dominates, superconducting domes are still likely to exist on the flanks of flat bands. We apply these general results to both the topological surface flat bands of rhombohedral ABC-stacked graphite and to the Van Hove singularity of graphene.
NASA Astrophysics Data System (ADS)
Nurdiani, N.
2018-03-01
Low cost flats in Jakarta – Indonesia is provided by the government for low-income people in urban areas, in line with the program to redevelop or renew slum areas. Low cost flat is built with the minimum standard of building materials. The purpose of this study is to know efforts of the occupants to change of building materials at residential unit of low cost flats. The research was conducted by descriptive method at four of low cost housing in Jakarta: Rusuna Bendungan Hilir 1, Rusuna Tambora IIIA, Rusuna Bidara Cina, and Rusuna Sukapura. The results showed that physical changes which happened in low cost flats are aesthetic (residence paint color change), or improvement of physical quality of residential unit (change of building material), become dominant aspects done by residents in four rusuna.
Experimental investigation of jet-induced loads on a flat plate in hover out-of-ground effect
NASA Technical Reports Server (NTRS)
Kuhlman, J. M.; Warcup, R. W.
1979-01-01
Effects of varying jet decay rate on jet-induced loads on a flat plate located in the plane of the jet exit perpendicular to the jet axis were investigated using a small-scale laboratory facility. Jet decay rate has been varied through use of two cylindrical centerbodies having either a flat or hemispherical tip, which were submerged various distances below the flat plate jet exit plane. Increased jet decay rate, caused by the presence of a center-body or plug in the jet nozzle, led to an increased jet-induced lift loss on the flat plate. Jet-induced lift losses reached 1 percent of the jet thrust for the quickest jet decay rates for plate areas equal to 100 times the effective jet exit area. The observed lift loss versus jet decay rate trend agreed well with results of previous investigations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office
This Corrective Action Investigation Plan contains the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office's approach to collect the data necessary to evaluate corrective action alternatives appropriate for the closure of Corrective Action Unit (CAU) 528, Polychlorinated Biphenyls Contamination (PCBs), Nevada Test Site (NTS), Nevada, under the Federal Facility Agreement and Consent Order. Located in the southwestern portion of Area 25 on the NTS in Jackass Flats (adjacent to Test Cell C [TCC]), CAU 528 consists of Corrective Action Site 25-27-03, Polychlorinated Biphenyls Surface Contamination. Test Cell C was built to support the Nuclear Rocket Development Stationmore » (operational between 1959 and 1973) activities including conducting ground tests and static firings of nuclear engine reactors. Although CAU 528 was not considered as a direct potential source of PCBs and petroleum contamination, two potential sources of contamination have nevertheless been identified from an unknown source in concentrations that could potentially pose an unacceptable risk to human health and/or the environment. This CAU's close proximity to TCC prompted Shaw to collect surface soil samples, which have indicated the presence of PCBs extending throughout the area to the north, east, south, and even to the edge of the western boundary. Based on this information, more extensive field investigation activities are being planned, the results of which are to be used to support a defensible evaluation of corrective action alternatives in the corrective action decision document.« less
12. VIEW OF THE ROCKY FLATS PLANT LOOKING WEST. AFTER ...
12. VIEW OF THE ROCKY FLATS PLANT LOOKING WEST. AFTER 38 YEARS, WEAPONS PRODUCTION CEASED IN 1989. IN 1992, THE PLANT MISSION CHANGED FROM WEAPONS PRODUCTION TO ENVIRONMENTAL CLEAN UP AND RESTORATION. BY 1995, THE SITE HAD BEGUN TO BE DISMANTLED (6/27/95). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO
49 CFR 173.4a - Excepted quantities.
Code of Federal Regulations, 2010 CFR
2010-10-01
... package or packing different materials in the package must not result in a violation of § 173.21. (6) Each... onto a solid unyielding surface from a height of 1.8 m (5.9 feet): (i) Where the sample is in the shape...; (B) One drop flat on the top; (C) One drop flat on the longest side; (D) One drop flat on the...
49 CFR 173.4 - Small quantities for highway and rail.
Code of Federal Regulations, 2012 CFR
2012-10-01
... solid materials; (iii) One (1) g (0.04 ounce) for authorized materials meeting the definition of a... drops made from a height of 1.8 m (5.9 feet) directly onto a solid unyielding surface without breakage... package: (A) One drop flat on bottom; (B) One drop flat on top; (C) One drop flat on the long side; (D...
Open-Access Textbooks and Financial Sustainability: A Case Study on Flat World Knowledge
ERIC Educational Resources Information Center
Hilton, John, III; Wiley, David
2011-01-01
Many college students and their families are concerned about the high costs of textbooks. A company called Flat World Knowledge both gives away and sells open-source textbooks in a way it believes to be financially sustainable. This article reports on the financial sustainability of the Flat World Knowledge open-source textbook model after one…
Soil physical and chemical properties associated with flat rock and riparian forest communities
David O. Mitchem; James E. Johnson; Laura S. Gellerstedt
2006-01-01
Flat Rock forest communities are unique ecosystems found adjacent to some large rivers in the Central and Southern Appalachian Mountains. Characterized by thin, alluvial soils overlying flat, resistant sandstone, these areas are maintained by severe flooding and have unique associated plant systems. With the advent of dams to control flooding in the 20th century, many...
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-13
... 14, 2011) (opinion on final results) (U.S. Steel Corp. I); Certain Hot- Rolled Carbon Steel Flat... DEPARTMENT OF COMMERCE International Trade Administration [A-533-820] Certain Hot-Rolled Carbon...-rolled carbon steel flat products from India. See U.S. Steel Corp. v. United States, No. 08-00216, 2012...
Federal Register 2010, 2011, 2012, 2013, 2014
2010-08-02
... review Antidumping Duty Proceedings Germany: Corrosion-Resistant Carbon Steel Flat Products, A- 8/1/09-7...-805.. South Korea: Corrosion-Resistant Carbon Steel Flat 8/1/09-7/31/10 Products, A-580-816 Light... South Korea: Corrosion-Resistant Carbon Steel Flat Products, C- 1/1/09-12/31/09 580-818 Stainless Steel...
NASA Astrophysics Data System (ADS)
Borncamp, David
2017-08-01
The stability of the CCD flat fields will be monitored using the calibration lamps. One set of observations for all the filters and another at a different epoch for a subset of filters will be taken during this cycle. High signal observations will be used to assess the stability of the pixel-to-pixel flat field structure and to monitor the position of the dust motes.
NASA Astrophysics Data System (ADS)
Borncamp, David
2016-10-01
The stability of the CCD flat fields will be monitored using the calibration lamps. One set of observations for all the filters and another at a different epoch for a subset of filters will be taken during this cycle. High signal observations will be used to assess the stability of the pixel-to-pixel flat field structure and to monitor the position of the dust motes.
Mussel beds are biological power stations on intertidal flats
NASA Astrophysics Data System (ADS)
Engel, Friederike G.; Alegria, Javier; Andriana, Rosyta; Donadi, Serena; Gusmao, Joao B.; van Leeuwe, Maria A.; Matthiessen, Birte; Eriksson, Britas Klemens
2017-05-01
Intertidal flats are highly productive areas that support large numbers of invertebrates, fish, and birds. Benthic diatoms are essential for the function of tidal flats. They fuel the benthic food web by forming a thin photosynthesizing compartment in the top-layer of the sediment that stretches over the vast sediment flats during low tide. However, the abundance and function of the diatom film is not homogenously distributed. Recently, we have realized the importance of bivalve reefs for structuring intertidal ecosystems; by creating structures on the intertidal flats they provide habitat, reduce hydrodynamic stress and modify the surrounding sediment conditions, which promote the abundance of associated organisms. Accordingly, field studies show that high chlorophyll a concentration in the sediment co-vary with the presence of mussel beds. Here we present conclusive evidence by a manipulative experiment that mussels increase the local biomass of benthic microalgae; and relate this to increasing biomass of microalgae as well as productivity of the biofilm across a nearby mussel bed. Our results show that the ecosystem engineering properties of mussel beds transform them into hot spots for primary production on tidal flats, highlighting the importance of biological control of sedimentary systems.
Communication: Two types of flat-planes conditions in density functional theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Yang, Xiaotian Derrick; Patel, Anand H. G.; González-Espinoza, Cristina E.
Using results from atomic spectroscopy, we show that there are two types of flat-planes conditions. The first type of flat-planes condition occurs when the energy as a function of the number of electrons of each spin, N{sub α} and N{sub β}, has a derivative discontinuity on a line segment where the number of electrons, N{sub α} + N{sub β}, is an integer. The second type of flat-planes condition occurs when the energy has a derivative discontinuity on a line segment where the spin polarization, N{sub α} – N{sub β}, is an integer, but does not have a discontinuity associated withmore » an integer number of electrons. Type 2 flat planes are rare—we observed just 15 type 2 flat-planes conditions out of the 4884 cases we tested—but their mere existence has implications for the design of exchange-correlation energy density functionals. To facilitate the development of functionals that have the correct behavior with respect to both fractional number of electrons and fractional spin polarization, we present a dataset for the chromium atom and its ions that can be used to test new functionals.« less
Amin, Mahul B; McKenney, Jesse K
2002-07-01
The classification of flat urothelial (transitional cell) lesions with atypia has historically varied in its application from institution to institution with no fewer than six major nomenclature systems proposed in the past 25 years. In 1998, the World Health Organization/ International Society of Urological Pathology (WHO/ISUP) published a consensus classification that included the following categories for flat urinary bladder lesions: reactive atypia, atypia of unknown significance, dysplasia (low-grade intraepithelial neoplasia), and carcinoma in situ (high-grade intraepithelial neoplasia). This classification expands the definition traditionally used for urothelial carcinoma in situ, basing its diagnosis primarily on the severity of cytologic changes. In proposing the classification system for flat lesions of the bladder with atypia, it was hoped that consistent use of uniform diagnostic terminology would ultimately aid in a better understanding of the biology of these lesions. In this review, the authors discuss the history of the concept of flat urothelial neoplasia, the rationale and histologic criteria for the WHO/ISUP diagnostic categories, an approach to the diagnosis of flat lesions, and problems and pitfalls associated with their recognition in routine surgical pathology specimens.
Immediate Ecological Impacts of the 2011 Tohoku Earthquake Tsunami on Intertidal Flat Communities
Urabe, Jotaro; Suzuki, Takao; Nishita, Tatsuki; Makino, Wataru
2013-01-01
Following the Great East Japan Earthquake in 2011, a large tsunami developed and struck the Pacific coast of eastern Japan. To assess the immediate impacts of the tsunami on coastal communities, changes in taxon composition and richness of macrobenthic animals before and after the tsunami were examined at nine intertidal flats in Sendai Bay and the Sanriku Ria coast. The results showed that 30–80% of taxa indigenously inhabiting intertidal flats disappeared after the tsunami. Among animal types, endobenthic and sessile epibenthic animals were more vulnerable to the tsunami than mobile epibenthic animals like shore crabs and snails. For all the intertidal flats examined, animals that were originally dwellers in lower tidal zones and not recorded before the tsunami were also found right after the tsunami, indicating that the tsunami not only took away many benthic taxa from the intertidal flats but also brought in some taxa from elsewhere. However, overall changes in taxon community composition were greater for intertidal flats that experienced larger inundation heights. These results showed that the ecological impacts of the tsunami were proportional to the physical impacts as gauged by wave height and that mobile epibenthic animals were less vulnerable to the tsunami. PMID:23650529
Immediate ecological impacts of the 2011 Tohoku earthquake tsunami on intertidal flat communities.
Urabe, Jotaro; Suzuki, Takao; Nishita, Tatsuki; Makino, Wataru
2013-01-01
Following the Great East Japan Earthquake in 2011, a large tsunami developed and struck the Pacific coast of eastern Japan. To assess the immediate impacts of the tsunami on coastal communities, changes in taxon composition and richness of macrobenthic animals before and after the tsunami were examined at nine intertidal flats in Sendai Bay and the Sanriku Ria coast. The results showed that 30-80% of taxa indigenously inhabiting intertidal flats disappeared after the tsunami. Among animal types, endobenthic and sessile epibenthic animals were more vulnerable to the tsunami than mobile epibenthic animals like shore crabs and snails. For all the intertidal flats examined, animals that were originally dwellers in lower tidal zones and not recorded before the tsunami were also found right after the tsunami, indicating that the tsunami not only took away many benthic taxa from the intertidal flats but also brought in some taxa from elsewhere. However, overall changes in taxon community composition were greater for intertidal flats that experienced larger inundation heights. These results showed that the ecological impacts of the tsunami were proportional to the physical impacts as gauged by wave height and that mobile epibenthic animals were less vulnerable to the tsunami.
Effects of the foil flatness on irradiation performance of U10Mo monolithic mini-plates
Ozaltun, Hakan; Medvedev, Pavel G.; Rabin, Barry H.
2015-09-03
Monolithic plate-type fuels comprise of a high density, low enrichment, U10Mo fuel foil encapsulated in a cladding material. This concept generates several fabrication challenges such as flatness, centering or thickness variation. There are concerns, if these parameters have implications on overall performance. To investigate these inquiries, the effects of the foil flatness were studied. For this, a representative plate was simulated for an ideal case. The simulations were repeated for additional cases with various foil curvatures to evaluate the effects on the irradiation performance. The results revealed that the stresses and strains induced by fabrication process are not affected bymore » the flatness of the foil. Furthermore, fabrication stresses in the foil are relieved relatively fast in the reactor. The effects of the foil flatness on peak irradiation stressstrains are minimal. There is a slight increase in temperature for the case with maximum curvature. The major impact is on the displacement characteristics. Furthermore, while the case with a flat foil produces a symmetrical swelling, if the foil is curved, more swelling occurs on the thin-cladding side and the plate bows during irradiation.« less
Cutting process simulation of flat drill
NASA Astrophysics Data System (ADS)
Tamura, Shoichi; Matsumura, Takashi
2018-05-01
Flat drills at a point angle of 180 deg. have recently been developed for drilling of automobile parts with the inclination of the workpiece surfaces. The paper studies the cutting processes of the flat drills in the analytical simulation. A predictive force model is applied to simulation of the cutting force with the chip flow direction. The chip flow model is piled up with orthogonal cuttings in the plane containing the cutting velocities and the chip flow velocities, in which the chip flow direction is determined to minimize the cutting energy. Then, the cutting force is predicted in the determined in the chip flow model. The typical cutting force of the flat drill is discussed with comparing to that of the standard drill. The typical differences are confirmed in the cutting force change during the tool engagement and disengagement. The cutting force, then, is simulated in drilling for an inclined workpiece with a flat drill. The horizontal components in the cutting forces are simulated with changing the inclination angle of the plate. The horizontal force component in the flat drilling is stable to be controlled in terms of the machining accuracy and the tool breakage.
Flow over a traveling wavy foil with a passively flapping flat plate
NASA Astrophysics Data System (ADS)
Liu, Nansheng; Peng, Yan; Liang, Youwen; Lu, Xiyun
2012-05-01
Flow over a traveling wavy foil with a passively flapping flat plate has been investigated using a multiblock lattice Boltzmann equation and the immersed boundary method. The foil undergoes prescribed undulations in the lateral direction and the rigid flat plate has passive motion determined by the fluid structure interaction. This simplified model is used to study the effect of the fish caudal fin and its flexibility on the locomotion of swimming animals. The flexibility of the caudal fin is modeled by a torsion spring acting about the pivot at the conjuncture of the wavy foil and the flat plate. The study reveals that the passively oscillating flat plate contributes half of the propulsive force. The flexibility, represented by the nondimensional natural frequency F, plays a very important role in the movement and propulsive force generation of the whole body. When the plate is too flexible, the drag force is observed. As the flat plate becomes more rigid, the propulsive force that is generated when the undulation is confined to last part of the wavy foil becomes larger. The steady movement occurs at F=5. These results are consistent with the observations of some swimming animals in nature.
NASA Astrophysics Data System (ADS)
Setare, M. R.; Adami, H.
2018-01-01
We apply the new fall of conditions presented in the paper [1] on asymptotically flat spacetime solutions of Chern-Simons-like theories of gravity. We show that the considered fall of conditions asymptotically solve equations of motion of generalized minimal massive gravity. We demonstrate that there exist two type of solutions, one of those is trivial and the others are non-trivial. By looking at non-trivial solutions, for asymptotically flat spacetimes in the generalized minimal massive gravity, in contrast to Einstein gravity, cosmological parameter can be non-zero. We obtain the conserved charges of the asymptotically flat spacetimes in generalized minimal massive gravity, and by introducing Fourier modes we show that the asymptotic symmetry algebra is a semidirect product of a BMS3 algebra and two U (1) current algebras. Also we verify that the BMS3 algebra can be obtained by a contraction of the AdS3 asymptotic symmetry algebra when the AdS3 radius tends to infinity in the flat-space limit. Finally we find energy, angular momentum and entropy for a particular case and deduce that these quantities satisfy the first law of flat space cosmologies.
Correcting Thermal Deformations in an Active Composite Reflector
NASA Technical Reports Server (NTRS)
Bradford, Samuel C.; Agnes, Gregory S.; Wilkie, William K.
2011-01-01
Large, high-precision composite reflectors for future space missions are costly to manufacture, and heavy. An active composite reflector capable of adjusting shape in situ to maintain required tolerances can be lighter and cheaper to manufacture. An active composite reflector testbed was developed that uses an array of piezoelectric composite actuators embedded in the back face sheet of a 0.8-m reflector panel. Each individually addressable actuator can be commanded from 500 to +1,500 V, and the flatness of the panel can be controlled to tolerances of 100 nm. Measuring the surface flatness at this resolution required the use of a speckle holography interferometer system in the Precision Environmental Test Enclosure (PETE) at JPL. The existing testbed combines the PETE for test environment stability, the speckle holography system for measuring out-of-plane deformations, the active panel including an array of individually addressable actuators, a FLIR thermal camera to measure thermal profiles across the reflector, and a heat source. Use of an array of flat piezoelectric actuators to correct thermal deformations is a promising new application for these actuators, as is the use of this actuator technology for surface flatness and wavefront control. An isogrid of these actuators is moving one step closer to a fully active face sheet, with the significant advantage of ease in manufacturing. No extensive rib structure or other actuation backing structure is required, as these actuators can be applied directly to an easy-to-manufacture flat surface. Any mission with a surface flatness requirement for a panel or reflector structure could adopt this actuator array concept to create lighter structures and enable improved performance on orbit. The thermal environment on orbit tends to include variations in temperature during shadowing or changes in angle. Because of this, a purely passive system is not an effective way to maintain flatness at the scale of microns over several meters. This technology is specifically referring to correcting thermal deformations of a large, flat structure to a specified tolerance. However, the underlying concept (an array of actuators on the back face of a panel for correcting the flatness of the front face) could be extended to many applications, including energy harvesting, changing the wavefront of an optical system, and correcting the flatness of an array of segmented deployable panels.
NASA Astrophysics Data System (ADS)
Xie, Tian; Cui, Baoshan; Bai, Junhong; Li, Shanze; Zhang, Shuyan
2018-02-01
Determining how human disturbance affects plant community persistence and species conservation is one of the most pressing ecological challenges. The large-scale disturbance form defense structures usually have a long-term and potential effect on phytocommunity in coastal saltmarshes. Coastal defense structures usually remove the effect of tidal wave on tidal salt marshes. As a consequence, edaphic factors such as the salinity and moisture contents are disturbed by tidal action blocking. However, few previous studies have explicitly addressed the response of halophyte species persistence and dynamics to the changing edaphic conditions. The understanding of the response of species composition in seed banks and aboveground vegetation to the stress is important to identify ecological effect of coastal defense structures and provide usefully insight into restoration. Here, we conducted a field study to distinguish the density, species composition and relationships of seed bank with aboveground vegetation between tidal flat wetlands with and without coastal defense structures. We also addressed the role of edaphic condition in vegetation degradation caused by coastal defense structures in combination with field monitor and greenhouse experiments. Our results showed the density of the seed bank and aboveground vegetation in the tidal flat without coastal defense structures was significantly lower than the surrounded flat with coastal defense structures. A total of 14 species were founded in the surrounded flat seed bank and 11 species in the tidal flat, but three species were only recorded in aboveground vegetation of the tidal flat which was much lower than 24 aboveground species in the surrounded flat. The absent of species in aboveground vegetation contributed to low germination rate which depend on the edaphic condition. The germination of seeds in the seed bank were inhabited by high soil salinity in the tidal flat and low soil moisture in the surrounded flat. Our study supported the hypothesis that the change of edaphic condition caused by coastal defense structures was the main reason for the difference of the species composition similarity between aboveground vegetation and the soil seed bank between the tidal and surrounded flats. Therefore, mitigating the hydrological disturbance and maintaining the original state of edaphic factors would be useful implications for reducing the ecological effect of defense structure to vegetation communities in coastal salt marshes.
Collins, Natalie J; Hinman, Rana S; Menz, Hylton B; Crossley, Kay M
2017-01-01
The purpose of the study was to determine whether prefabricated foot orthoses immediately reduce pain during functional tasks in people with patellofemoral osteoarthritis, compared to flat insoles and shoes alone. Eighteen people with predominant lateral patellofemoral osteoarthritis (nine women; mean [SD] age 59 [10]years; body mass index 27.9 [3.2]kg/m 2 ) performed functional tasks wearing running sandals, and then wearing foot orthoses and flat insoles (random order). Participants rated knee pain during each task (11-point numerical rating scales), ease of performance and knee stability (five-point Likert scales), and comfort (100mm visual analogue scales). Compared to shoes alone, foot orthoses (p=0.002; median difference 1.5 [IQR 3]) and flat insoles (p<0.001; 2 [3]) significantly reduced pain during step-downs; foot orthoses reduced pain during walking (p=0.008; 1 [1.25]); and flat insoles reduced pain during stair ambulation (p=0.001; 1 [1.75]). No significant differences between foot orthoses and flat insoles were observed for pain severity, ease of performance or knee stability. Foot orthoses were less comfortable than flat insoles and shoes alone (p<0.05). In people with patellofemoral osteoarthritis, immediate pain-relieving effects of prefabricated, contoured foot orthoses are equivalent to flat insoles. Further studies should investigate whether similar outcomes occur with longer-term wear or different orthosis designs. Copyright © 2016 Elsevier B.V. All rights reserved.
Idaho National Engineering Laboratory code assessment of the Rocky Flats transuranic waste
DOE Office of Scientific and Technical Information (OSTI.GOV)
NONE
1995-07-01
This report is an assessment of the content codes associated with transuranic waste shipped from the Rocky Flats Plant in Golden, Colorado, to INEL. The primary objective of this document is to characterize and describe the transuranic wastes shipped to INEL from Rocky Flats by item description code (IDC). This information will aid INEL in determining if the waste meets the waste acceptance criteria (WAC) of the Waste Isolation Pilot Plant (WIPP). The waste covered by this content code assessment was shipped from Rocky Flats between 1985 and 1989. These years coincide with the dates for information available in themore » Rocky Flats Solid Waste Information Management System (SWIMS). The majority of waste shipped during this time was certified to the existing WIPP WAC. This waste is referred to as precertified waste. Reassessment of these precertified waste containers is necessary because of changes in the WIPP WAC. To accomplish this assessment, the analytical and process knowledge available on the various IDCs used at Rocky Flats were evaluated. Rocky Flats sources for this information include employee interviews, SWIMS, Transuranic Waste Certification Program, Transuranic Waste Inspection Procedure, Backlog Waste Baseline Books, WIPP Experimental Waste Characterization Program (headspace analysis), and other related documents, procedures, and programs. Summaries are provided of: (a) certification information, (b) waste description, (c) generation source, (d) recovery method, (e) waste packaging and handling information, (f) container preparation information, (g) assay information, (h) inspection information, (i) analytical data, and (j) RCRA characterization.« less
NASA Astrophysics Data System (ADS)
Chang, Tae Soo; Hong, Seok Hwi; Chun, Seung Soo; Choi, Jeong-Heon
2017-08-01
The Dasari beach-dune system fronted by an intertidal mud flat is a typical example of numerous small beaches found both in embayments and along the open macrotidal west coast of Korea. The beach is frequently exposed to energetic wave action at high tide in winter. Although this coastal dune-sandy beach-intertidal mud flat system has previously been described, its origin and morphodynamic behavior has to date not been firmly established. To clarify these issues, elevation profiles and surficial sediment samples were collected seasonally along five monitoring transects across the tidal flat. In addition, box-cores as well as vibro- and drill-cores were acquired along the middle transect. Optically stimulated luminescence (OSL) and 14C- AMS (accelerator mass spectrometry) dating methods were applied to determine the age of the tidal flat, the beach and the dune deposits. The results show that Dasari beach is topographically composed of two distinct morphological and sedimentological sectors, comprising a high-tide sandy beach that merges seaward into an extensive low-tide tidal flat composed of mud. The transition between the two sectors is marked by a sharp break in slope and change in internal sedimentary structures. At the boundary, the subtle shoreward fining trend in mean grain size on the intertidal flat switches to a pronounced shoreward coarsening trend. Near the transition, mixing between the beach sand and the mud is observed. Another striking feature is a seasonal rotation of the beach system centered on the middle sector, with the northern sector eroding in winter and accreting in summer, and the southern sector accreting in winter and eroding in summer. The spatial grain-size pattern reveals that the beach is fed from the neighboring beach in the north by lateral headland bypassing, rather than onshore transport across the tidal flat, the intermittent lateral supply of sand explaining the seasonal rotation of the beach. Stratigraphically, the beach-dune deposits are underlain by muddy tidal flat deposits, which results in a clear upward coarsening grain-size trend and thus intimates transgressive deposition associated with sea-level rise over the past 7-8 ka. However, a time gap of 4-5 thousand years between the tidal flat and the beach-dune deposits indicates that there is no genetic link between the two depositional systems. As the modern beach-dune system is remote from the former landward limit of the tidal flat, a continuous retreat model must be rejected. Instead, a lateral headland bypassing model, in which sand supplied alongshore progressively encroached the tidal flat, is more plausible. In the light of this interpretation, many of the barrier beach-lagoon models proposed for the macrotidal west coast of Korea need to be reconsidered.
Stationary Digital Tomosynthesis System for Early Detection of Breast Tumors
2011-05-01
selenium flat panel detector. Proc. SPIE 2005. 5745: p. 529-540 4. Kopans, D.B., Breast Imaging. 2 ed. 1997, New York Lippincott Williams and...same. 2005. 8. M. Bissonnette, et al. Digital breast tomosynthesis using an amorphous selenium flat panel detector. in Medical Imaging 2005...tomosynthesis system with selenium based flat panel detector. Proc of SPIE, Physics of Medical Imaging, 2005. 5745. 12
Testing of flat conductor cable to Underwriters Laboratory standards UL719 and UL83
NASA Technical Reports Server (NTRS)
Loggins, R. W.; Herndon, R. H.
1974-01-01
The flat conductor cable (FCC) which was tested consisted of three AWG No. 12 flat copper conductors laminated between two films of polyethylene terephthalate (Mylar) insulation with a self-extinguishing polyester adhesive. Results of the tests conducted on this cable, according to specifications, warrants the use of this FCC for electrical interconnections in a surface nonmetallic protective covering.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-05
... Decree in United States of America v. AGC Flat Glass North America, Inc., et al., Civil Action No. 1:10... County, West Virginia (the ``Site''). The Consent Decree obligates AGC Flat Glass North America, Inc. and... States of America v. AGC Flat Glass North America, Inc., et al., Civil Action No. 1:10-cv-00069-IMK, (N.D...
For current viewing resistor loads
Lyons, Gregory R [Tijeras, NM; Hass, Jay B [Lee's Summit, MO
2011-04-19
The invention comprises a terminal unit for a flat cable comprising a BNC-PCB connector having a pin for electrically contacting one or more conducting elements of a flat cable, and a current viewing resistor having an opening through which the pin extends and having a resistor face that abuts a connector face of the BNC-PCB connector, wherein the device is a terminal unit for the flat cable.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-22
... certain BMW vehicles equipped with ``run-flat'' tires do not fully comply with paragraphs S4.3(c) and S4.3... equipped with ``run flat'' tires are affected. The affected vehicle models are certain: Model Year 2008... equipped with ``run-flat'' tires and have no spare tire, the word ``none,'' as required by paragraphs S4.3...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-01
... Proceedings Germany: Corrosion-Resistant Carbon Steel Flat Products, A- 8/1/10-7/31/11 428-815 Certain Small... (Under 4\\1/2\\ Inches), A-485-805.. South Korea: Corrosion-Resistant Carbon Steel Flat Products, A- 8/1/10... Korea: Corrosion-Resistant Carbon Steel Flat Products, C- 1/1/10-12/31/10 580-818 Stainless Steel Sheet...
NASA Astrophysics Data System (ADS)
Lee, Yoon-Kyung; Choi, Jong-Kuk; Ryu, Joo-Hyung; Eom, Jinah
2014-05-01
Tidal flats are valuable ecosystem by a productive flora and fauna which support large populations of birds, form nursery and feeding areas for coastal fisheries, provide intrinsic values such as aesthetics and education (Costanza et al., 1997; Goodwin et al., 2001). The half of the world's coastal wetlands will submerge during this century in response to sea level rise although salt marsh has a capacity to adjust to sea level rise change. However, tidal flats have been changed because of several coastal construction projects that had not been considered sustainable over the last 30 years in Korean Peninsula. The total area of tidal flats decreased from approximately 2,800 km2 in 1990 to 2,393 km2 in 2005 due to the land reclamations and dredging in South Korea. Many researchers investigated topography, sedimentation changes and local hydrodynamics for this area in the early 1990s. However, they are limited to the temporal and spatial scale because field surveys in the tidal flats are restricted due to the difficulties in accessing. The aim of this study was to examine environmental change in tidal flat in a large scale for long-term based on the remotely sensed data as well as in situ measurements. This study focused on the tidal flat that not only had been affected by reclamations on a large scale such as Ganghwa and Saemangeum but also had been indirectly affected by reclamations such as Hwang-do and Gomso-bay. In this study, changes in morphology and sedimentary facies in tidal flats were estimated. Digital elevation models (DEMs) in early 2000 and 2010 were generated based on the Landsat TM/ETM+ images using a waterline method. Morphological change was estimated based on the differences of DEMs and sedimentary facies was investigated based on the calculation of image-derived PCA coefficient. Results of the morphological change in tidal flats interestingly showed that large amount of areas had been deposited whereas the other areas were eroded. Area with deposited tendency showed increase in fine sediments whereas area with eroded tendency showed increase in coarse sediments. This result was compared with the tidal current speed estimated from a hydrological model.
26. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING NORTHEAST. ...
26. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING NORTHEAST. IN 1951, A GOOD FRIDAY ISSUE OF THE DENVER POST ANNOUNCED THE ATOMIC ENERGY COMMISSION'S PLANS TO BUILD THE ROCKY FLATS PLANT. UNDER THE HEADLINE 'THERE'S GOOD NEWS TODAY.' POLITICAL LEADERS EXPRESSED GREAT PRIDE IN THE CHOICE OF THE DENVER-BOULDER AREA AS THE SITE FOR AN ATOMIC PLANT AS QUOTED IN THE ROCKY MOUNTAIN NEWS: 'WE ARE PROUD THAT THE AREA HAS BEEN CHOSEN FOR ANOTHER IMPORTANT CONTRIBUTION TO THE NATION'S STRENGTH AND FUTURE SECURITY.' BY THE MID 1970S, PUBLIC OPINION OF THE SITE HAD CHANGED (5/4/78). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO
Generation of flat-top pulsed magnetic fields with feedback control approach.
Kohama, Yoshimitsu; Kindo, Koichi
2015-10-01
We describe the construction of a simple, compact, and cost-effective feedback system that produces flat-top field profiles in pulsed magnetic fields. This system is designed for use in conjunction with a typical capacitor-bank driven pulsed magnet and was tested using a 60-T pulsed magnet. With the developed feedback controller, we have demonstrated flat-top magnetic fields as high as 60.64 T with an excellent field stability of ±0.005 T. The result indicates that the flat-top pulsed magnetic field produced features high field stability and an accessible field strength. These features make this system useful for improving the resolution of data with signal averaging.
Friction factor data for flat plate tests of smooth and honeycomb surfaces. M.S. Thesis
NASA Technical Reports Server (NTRS)
Ha, Tae Woong
1989-01-01
Friction factors for honeycomb surfaces were measured with a flat plate tester. The flat plate test apparatus was described and a method was discussed for determining the friction factor experimentally. The friction factor model was developed for the flat plate test based on the Fanno Line Flow. The comparisons of the friction factor were plotted for smooth surfaces and six-honeycomb surfaces with three-clearances, 6.9 bar to 17.9 bar range of inlet pressures, and 5,000 to 100,000 range of the Reynolds number. The optimum geometries for the maximum friction factor were found as a function of cell width to cell depth and cell width to clearance ratios.
AmeriFlux US-Seg Sevilleta grassland
Litvak, Marcy [University of New Mexico
2016-01-01
This is the AmeriFlux version of the carbon flux data for the site US-Seg Sevilleta grassland. Site Description - The Sevilleta Desert Grassland site is located within the McKenzie Flats area of the Sevilleta National Wildlife Refuge (NWR), central New Mexico. Historically, this area has been used for livestock grazing; however, the McKenzie Flats have not been grazed since 1973 and the effects of this previous grazing are considered negligible for the purposes of this study. As the name suggests, McKenzie Flats is an extensive (~130 km2), nearly flat, mixed-species desert grassland bounded on the east by Los Pinos Mountains and on the west by the Rio Grande.
AmeriFlux US-Ses Sevilleta shrubland
Litvak, Marcy [University of New Mexico
2016-01-01
This is the AmeriFlux version of the carbon flux data for the site US-Ses Sevilleta shrubland. Site Description - The Sevilleta Desert Shrubland site is located within the McKenzie Flats area of the Sevilleta National Wildlife Refuge (NWR), central New Mexico. Historically, this area has been used for livestock grazing; however, the McKenzie Flats have not been grazed since 1973 and the effects of this previous grazing are considered negligible for the purposes of this study. As the name suggests, McKenzie Flats is an extensive (~130 km2), nearly flat, mixed-species desert grassland bounded on the east by Los Pinos Mountains and on the west by the Rio Grande.
Improvement of illumination uniformity for LED flat panel light by using micro-secondary lens array.
Lee, Hsiao-Wen; Lin, Bor-Shyh
2012-11-05
LED flat panel light is an innovative lighting product in recent years. However, current flat panel light products still contain some drawbacks, such as narrow lighting areas and hot spots. In this study, a micro-secondary lens array technique was proposed and applied for the design of the light guide surface to improve the illumination uniformity. By using the micro-secondary lens array, the candela distribution of the LED flat panel light can be adjusted to similar to batwing distribution to improve the illumination uniformity. The experimental results show that the enhancement of the floor illumination uniformity is about 61%, and that of the wall illumination uniformity is about 20.5%.
Cole, James C.; Harris, Anita G.; Wahl, Ronald R.
1997-01-01
This map displays interpreted structural and stratigraphic relations among the Paleozoic and older rocks of the Nevada Test Site region beneath the Miocene volcanic rocks and younger alluvium in the Yucca Flat and northern Frenchman Flat basins. These interpretations are based on a comprehensive examination and review of data for more than 77 drillholes that penetrated part of the pre-Tertiary basement beneath these post-middle Miocene structural basins. Biostratigraphic data from conodont fossils were newly obtained for 31 of these holes, and a thorough review of all prior microfossil paleontologic data is incorporated in the analysis. Subsurface relationships are interpreted in light of a revised regional geologic framework synthesized from detailed geologic mapping in the ranges surrounding Yucca Flat, from comprehensive stratigraphic studies in the region, and from additional detailed field studies on and around the Nevada Test Site.All available data indicate the subsurface geology of Yucca Flat is considerably more complicated than previous interpretations have suggested. The western part of the basin, in particular, is underlain by relics of the eastward-vergent Belted Range thrust system that are folded back toward the west and thrust by local, west-vergent contractional structures of the CP thrust system. Field evidence from the ranges surrounding the north end of Yucca Flat indicate that two significant strike-slip faults track southward beneath the post-middle Miocene basin fill, but their subsurface traces cannot be closely defined from the available evidence. In contrast, the eastern part of the Yucca Flat basin is interpreted to be underlain by a fairly simple north-trending, broad syncline in the pre-Tertiary units. Far fewer data are available for the northern Frenchman Flat basin, but regional analysis indicates the pre- Tertiary structure there should also be relatively simple and not affected by thrusting.This new interpretation has implications for ground water flow through pre-Tertiary rocks beneath the Yucca Flat and northern Frenchman Flat areas, and has consequences for ground water modeling and model validation. Our data indicate that the Mississippian Chainman Shale is not a laterally extensive confining unit in the western part of the basin because it is folded back onto itself by the convergent structures of the Belted Range and CP thrust systems. Early and Middle Paleozoic limestone and dolomite are present beneath most of both basins and, regardless of structural complications, are interpreted to form a laterally continuous and extensive carbonate aquifer. Structural culmination that marks the French Peak accommodation zone along the topographic divide between the two basins provides a lateral pathway through highly fractured rock between the volcanic aquifers of Yucca Flat and the regional carbonate aquifer. This pathway may accelerate the migration of ground-water contaminants introduced by underground nuclear testing toward discharge areas beyond the Nevada Test Site boundaries. Predictive three-dimensional models of hydrostratigraphic units and ground-water flow in the pre-Tertiary rocks of subsurface Yucca Flat are likely to be unrealistic due to the extreme structural complexities. The interpretation of hydrologic and geochemical data obtained from monitoring wells will be difficult to extrapolate through the flow system until more is known about the continuity of hydrostratigraphic units.
Performance of Emcore Third Generation CPV Modules in the Low Latitude Marine Environment of Hawaii
NASA Astrophysics Data System (ADS)
Hoffman, Richard; Buie, Damien; King, David; Glesne, Thomas
2011-12-01
Emcore third generation concentrating photovoltaic (CPV) modules were evaluated in the low latitude location of Kihei, Hawaii. For comparison, the best available monocrystalline silicon flat panel modules were included in both dual-axis tracked and fixed mount configurations. The daily DC uncorrected efficiency value for the CPV modules averaged over the six-month performance period was 25.9% compared to 16% to 17% for the flat panels. Higher daily energy was obtained from CPV modules than tracked flat panels when daily direct solar insolation was greater than 5 kWh/m2 and more than fixed mount flat panel when direct insolation was greater than 3 kWh/m2. The module energy conversion performance was demonstrated to be predictable using a parametric model developed by Sandia National Laboratory. Soiling accumulation on module entrance surface was surprisingly rapid in the local environment. Measured energy loss rate due to soiling were two to six times larger for CPV compared to flat panel losses.
NASA Astrophysics Data System (ADS)
Zernial, W.
1982-12-01
The industrial productibility of a selective absorbing thin film was investigated on the basis of reactive cathodic sputtering of Ni. On substrates of 1.8 sq m of Al, Cu, steel and stainless steel, solar absorption values up to 97% were achieved at emissivities of 5 to 10%. A prototype flat plate collector for high temperatures with two covers and hermetical sealing was developed. The technical data of the collector were measured, dependent on the selectivity of the absorber, gas fillings of dry air, argon or SF6 and the geometry and were compared with those of an evacuated flat plate collector. A hermetical sealed double flat plate collector for low temperatures was developed which has the advantage of lower no load temperatures and higher energy gain for heating swimming pool water compared with a conventional flat plate collector. The insolation values on collectors were measured and were used for a calculation of the energy gains of different collector types.
Williams, Phillip A; Djordjevic, Bojana; Ayroud, Yasmine; Islam, Shahidul; Gravel, Denis; Robertson, Susan J; Parra-Herran, Carlos
2014-12-01
To identify morphometric features unique to flat epithelial atypia associated with cancer using digital image analysis. Cases with diagnosis of flat epithelial atypia were retrieved and divided into 2 groups: flat epithelial atypia associated with invasive or in situ carcinoma (n = 31) and those without malignancy (n = 27). Slides were digitally scanned. Nuclear features were analyzed on representative images at 20x magnification using digital morphometric software. Parameters related to nuclear shape and size (diameter, perimeter) were similar in both groups. However, cases with malignancy had significantly higher densitometric green (p = 0.02), red (p = 0.03), and grey (p = 0.02) scale levels as compared to cases without cancer. A mean grey densitometric level > 119.45 had 71% sensitivity and 70.4% specificity in detecting cases with concomitant carcinoma. Morphometry of features related to nuclear staining appears to be useful in predicting risk of concurrent malignancy in patients with flat epithelial atypia, when added to a comprehensive histopathologic evaluation.
Carr, W.J.
1982-01-01
New evidence for a possible resurgent dome in the caldera related to eruption of the Bullfrog Member of the Crater Flat Tuff has been provided by recent drilling of a 762-meter (2,501-foot) hole in central Crater Flat. Although no new volcanic units were penetrated by the drill hole (USW-VH-1), the positive aeromagnetic anomaly in the vicinity of the drill hole appears to result in part from the unusually thick, densely welded tuff of the Bullfrog. Major units penetrated include alluvium, basalt of Crater Flat, Tiva Canyon and Topopah Spring Members of the Paintbrush Tuff, and Prow Pass and Bullfrog Members of the Crater Flat Tuff. In addition, the drill hole provided the first subsurface hydrologic information for the area. The water table in the hole is at about 180 meters (600 feet), and the temperature gradient appears slightly higher than normal for the region.
Flat Lens Focusing Demonstrated With Left-Handed Metamaterial
NASA Technical Reports Server (NTRS)
Wilson, Jeffrey D.; Schwartz, Zachary D.; Chevalier, Christine T.; Downey, Alan N.; Vaden, Karl R.
2004-01-01
Left-handed metamaterials (LHM's) are a new media engineered to possess an effective negative index of refraction over a selected frequency range. This characteristic enables LHM's to exhibit physical properties never before observed. In particular, a negative index of refraction should cause electromagnetic radiation to refract or bend at a negative angle when entering an LHM, as shown in the figure above on the left. The figure on the right shows that this property could be used to bring radiation to a focus with a flat LHM lens. The advantage of a flat lens in comparison to a conventional curved lens is that the focal length could be varied simply by adjusting the distance between the lens and the electromagnetic wave source. In this in-house work, researchers at the NASA Glenn Research Center developed a computational model for LHM's with the three-dimensional electromagnetic commercial code Microwave Studio, constructed an LHM flat lens, and used it to experimentally demonstrate the reversed refraction and flat lens focusing of microwave radiation.
Selected hydrologic data for the Bonneville Salt Flats and Pilot Valley, western Utah, 1991-93
Mason, James L.; Brothers, William C.; Gerner, Linda J.; Muir, Pamela S.
1995-01-01
This report contains hydrologic data collected during 1991-93 in the Bonneville Salt Flats and Pilot Valley study area of western Utah. These data were collected in cooperation with the U.S. Department of the Interior, Bureau of Land Management, as part of a study to investigate possible salt loss from the Bonneville Salt Flats. The Bonneville Salt Flats and adjacent Pilot Valley are located in the western part of the Great Salt Lake Desert in Utah, near the Nevada border. The Bonneville Salt Flats playa has a thick, perennial salt crust and the Pilot Valley playa has a thin, ephemeral salt crust. Well-completion data, including well depth and screened intervals, are presented in this report for selected shallow and deep monitoring wells. Water-level measurements are reported with corresponding specfic-gravity and temperature measurements. Results of chemical analyses are reported for brine collected from wells and pore fluids extracted from cores.
Selective adsorption of a supramolecular structure on flat and stepped gold surfaces
NASA Astrophysics Data System (ADS)
Peköz, Rengin; Donadio, Davide
2018-04-01
Halogenated aromatic molecules assemble on surfaces forming both hydrogen and halogen bonds. Even though these systems have been intensively studied on flat metal surfaces, high-index vicinal surfaces remain challenging, as they may induce complex adsorbate structures. The adsorption of 2,6-dibromoanthraquinone (2,6-DBAQ) on flat and stepped gold surfaces is studied by means of van der Waals corrected density functional theory. Equilibrium geometries and corresponding adsorption energies are systematically investigated for various different adsorption configurations. It is shown that bridge sites and step edges are the preferred adsorption sites for single molecules on flat and stepped surfaces, respectively. The role of van der Waals interactions, halogen bonds and hydrogen bonds are explored for a monolayer coverage of 2,6-DBAQ molecules, revealing that molecular flexibility and intermolecular interactions stabilize two-dimensional networks on both flat and stepped surfaces. Our results provide a rationale for experimental observation of molecular carpeting on high-index vicinal surfaces of transition metals.
NASA Astrophysics Data System (ADS)
Golmohammady, Sh; Ghafary, B.
2016-06-01
In this study, generalized Stokes parameters of a phase-locked partially coherent flat-topped array beam based on the extended Huygens-Fresnel principle and the unified theory of coherence and polarization have been reported. Analytical formulas for 2 × 2 cross-spectral density matrix elements, and consequently Stokes parameters of a phase-locked partially coherent flat-topped array beam propagating through the turbulent atmosphere have been formulated. Effects of many physical attributes such as wavelength, turbulence strength, flatness order and other source parameters on the Stokes parameters, and therefore spectral degree of polarization upon propagation have been studied thoroughly. The behaviour of the spectral degree of coherence of a delineated beam for different source conditions has been investigated. It can be shown that four generalized Stokes parameters increase by raising the flatness order at the same propagation distance. Increasing the number of beams leads to a decrease in the Stokes parameters to zero slowly. The results are of utmost importance for optical communications.
Spin-imbalanced pairing and Fermi surface deformation in flat bands
NASA Astrophysics Data System (ADS)
Huhtinen, Kukka-Emilia; Tylutki, Marek; Kumar, Pramod; Vanhala, Tuomas I.; Peotta, Sebastiano; Törmä, Päivi
2018-06-01
We study the attractive Hubbard model with spin imbalance on two lattices featuring a flat band: the Lieb and kagome lattices. We present mean-field phase diagrams featuring exotic superfluid phases, similar to the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, whose stability is confirmed by dynamical mean-field theory. The nature of the pairing is found to be richer than just the Fermi surface shift responsible for the usual FFLO state. The presence of a flat band allows for changes in the particle momentum distributions at null energy cost. This facilitates formation of nontrivial superfluid phases via multiband Cooper pair formation: the momentum distribution of the spin component in the flat band deforms to mimic the Fermi surface of the other spin component residing in a dispersive band. The Fermi surface of the unpaired particles that are typical for gapless superfluids becomes deformed as well. The results highlight the profound effect of flat dispersions on Fermi surface instabilities, and provide a potential route for observing spin-imbalanced superfluidity and superconductivity.
NASA Technical Reports Server (NTRS)
Romanofsky, Robert R.
1996-01-01
The flat-band voltage is the Schottky junction voltage required to shrink the depletion width to zero. At cryogenic temperatures, mixer diodes are generally biased and/or pumped beyond the flat-band condition to minimize conversion loss and noise figure. This occurs despite the presumed sharp increase in junction capacitance near flat-band, which should instead limit mixer performance. Past moderate forward bias, the diode C-V relationship is difficult to measure. A simple analytic expression for C(V) is usually used to model and predict mixer performance. This letter provides experimental data on C(V) at 77 K based on a microwave measurement and modeling technique. Data is also provided on the conversion loss of a singly balanced mixer optimized for 77 K operation. The connection between junction capacitance, flat-band potential, and conversion loss is examined. It is shown that the analytic expression greatly overestimates the junction capacitance that occurs as flat-band is approached.
NASA Astrophysics Data System (ADS)
Chan, Hoy-Yen; Vinson, A. A.; Baljit, S. S. S.; Ruslan, M. H.
2018-04-01
Flat plate solar air collector is the most common collector design, which is relatively simpler to fabricate and lower cost. In the present study, perforated plate solar collector was developed to improve the system thermal performance. A glazed perforated plate of 6mm holes diameter with square geometry was designed and installed as the absorber of the collector. The influences of solar radiation intensity and mass flow rate on the thermal performance were investigated. The perforated collector was compared with the flat plate solar collector under the same operating conditions. The highest values of thermal efficiency in this study for the perforated plate (PP) and the flat plate (FP) solar collectors were 59% and 36% respectively, at solar radiation intensity of 846 Wm-2 and mass flow rate of 0.02 kgs-1. Furthermore, PP collector gave better thermal performance compared to FP collector; and compared to previous studies, the present perforated design was compatible with the flat plate with double pass designs.
Narrowband Angular Reflectance Properties of the Alkali Flats at White Sands, New Mexico
NASA Technical Reports Server (NTRS)
Whitlock, Charles H.; LeCroy, Stuart R.; Wheeler, Robert J.
1994-01-01
Results from helicopter measurements of the angular properties of surface reflectance for the alkali flats regions of the White Sands Missile Range are presented for the wavelength interval of 0.4 to 0.85 microns. This work was performed to allow accurate radiative transfer calculations over the region. Detailed tables and interpolation equations are given that permit other investigators to perform satellite calibrations over the alkali flats site. The effects of wavelength and soil moisture on narrowband angular reflectance are also investigated. Although there is a spectral variation in surface albedo, there is little spectral effect in Anisotropic Factor except in the forward scattering peak at solar zenith angles greater than 60 deg. The magnitude of the forward-scattering peak is also sensitive to soil moisture, with wet conditions causing a larger peak. The significance of this result is that angular reflectance properties at the center of the alkali flats usually will be different than those at the flats edge because moisture differences typically exist.
Bauer, Christina T; Kroner, Elmar; Fleck, Norman A; Arzt, Eduard
2015-10-23
Nature uses hierarchical fibrillar structures to mediate temporary adhesion to arbitrary substrates. Such structures provide high compliance such that the flat fibril tips can be better positioned with respect to asperities of a wavy rough substrate. We investigated the buckling and adhesion of hierarchically structured adhesives in contact with flat smooth, flat rough and wavy rough substrates. A macroscopic model for the structural adhesive was fabricated by molding polydimethylsiloxane into pillars of diameter in the range of 0.3-4.8 mm, with up to three different hierarchy levels. Both flat-ended and mushroom-shaped hierarchical samples buckled at preloads one quarter that of the single level structures. We explain this behavior by a change in the buckling mode; buckling leads to a loss of contact and diminishes adhesion. Our results indicate that hierarchical structures can have a strong influence on the degree of adhesion on both flat and wavy substrates. Strategies are discussed that achieve highly compliant substrates which adhere to rough substrates.
NASA Astrophysics Data System (ADS)
Medjoubi, K.; Dawiec, A.
2017-12-01
A simple method is proposed in this work for quantitative evaluation of the quality of the threshold adjustment and the flat-field correction of Hybrid Photon Counting pixel (HPC) detectors. This approach is based on the Photon Transfer Curve (PTC) corresponding to the measurement of the standard deviation of the signal in flat field images. Fixed pattern noise (FPN), easily identifiable in the curve, is linked to the residual threshold dispersion, sensor inhomogeneity and the remnant errors in flat fielding techniques. The analytical expression of the signal to noise ratio curve is developed for HPC and successfully used as a fit function applied to experimental data obtained with the XPAD detector. The quantitative evaluation of the FPN, described by the photon response non-uniformity (PRNU), is measured for different configurations (threshold adjustment method and flat fielding technique) and is demonstrated to be used in order to evaluate the best setting for having the best image quality from a commercial or a R&D detector.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
This volume contains appendices for the following: Rocky Flats Plant and Idaho National Engineering Laboratory waste process information; TRUPACT-II content codes (TRUCON); TRUPACT-II chemical list; chemical compatibility analysis for Rocky Flats Plant waste forms; chemical compatibility analysis for waste forms across all sites; TRU mixed waste characterization database; hazardous constituents of Rocky Flats Transuranic waste; summary of waste components in TRU waste sampling program at INEL; TRU waste sampling program; and waste analysis data.
Ground states of baryoleptonic Q-balls in supersymmetric models
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shoemaker, Ian M.; Kusenko, Alexander
2008-10-01
In supersymmetric generalizations of the standard model, all stable Q-balls are associated with some flat directions. We show that, if the flat direction has both the baryon number and the lepton number, the scalar field inside the Q-ball can deviate slightly from the flat direction in the ground state. We identify the true ground states of such nontopological solitons, including the electrically neutral and electrically charged Q-balls.
AmeriFlux US-Prr Poker Flat Research Range Black Spruce Forest
Suzuki, Rikie [Japan Agency for Marine-Earth Science and Technology
2016-01-01
This is the AmeriFlux version of the carbon flux data for the site US-Prr Poker Flat Research Range Black Spruce Forest. Site Description - This site is located in a blackspruce forest within the property of the Poker Flat Research Range, University of Alaska, Fairbanks. Time-lapse image of the canopy is measured at the same time to relate flux data to satellite images.
Geomorphic Modeling of Macro-Tidal Embayment with Extensive Tidal Flats: Skagit Bay, Washington
2011-09-30
tidal flats: Skagit Bay , Washington Lyle Hibler Battelle-Pacific Northwest Division Marine Sciences Laboratory Sequim , WA 98382 phone: (360) 681...3616 fax: (360) 681-4559 email: lyle.hibler@pnnl.gov Adam Maxwell Battelle-Pacific Northwest Division Marine Sciences Laboratory Sequim , WA...Geomorphic modeling of macro-tidal embayment with extensive tidal flats: Skagit Bay , Washington 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT
Equal Weights, Flat Maxima, and Trivial Decisions.
1980-06-01
EQUAL WEIGhTrS, FLAT MAXMA, AND TRIVIAL DECISI(IS Research Report 80-2 Richard S. John, Ward Edwards, and Detlof v. Winterfeldt Social Science...research institute - Research Report 80-2 EQUAL IIG’ITS, FLAT MAXIM., AND- TRIVIAL DECISIONS : Richard S*i John-, Wad Edwards, and Detlof v...Winterfeldt " Social Science Research -Institute University of Southern Califomia . F. Hutton Barron School of Business - University of.Kansas Sponsored by
Investigation of Heat Transfer to a Flat Plate in a Shock Tube.
1987-12-01
2 Objectives and Scope . . . . . .. .. .. .... 5 11. Theory ............... ....... 7 Shock Tube Principles........... 7 Boundary Layer Theory ...in *excess of theory , but the rounded edge flat plate exhibited data which matched or was less than what theory predicted for each Mach number tested...normal shock advancing along an infinite flat plate. For x< Ugt there is a region of interaction between the downstream influence of the leading edge
Elastic Buckling under Combined Stresses of Flat Plates with Integral Waffle-Like Stiffening
NASA Technical Reports Server (NTRS)
Dow, Norris F.; Levin, L. Ross; Troutman, John L.
1953-01-01
Theory and experiment were compared and found in good agreement for the elastic Buckling under combined stresses of long flat plates with integral waffle-like stiffening in a variety of configurations. For such flat plates, 45deg waffle stiffening was found to be the most effective of the configurations for the proportions considered over the widest range of combinations of compression and shear.
Elastic Buckling Under Combined Stresses of Flat Plates with Integral Waffle-like Stiffening
NASA Technical Reports Server (NTRS)
Dow, Norris F; Levin, L Ross; Troutman, John L
1954-01-01
Theory and experiment were compared and found in good agreement for the elastic buckling under combined stresses of long flat plates with integral waffle-like stiffening in a variety of configurations. For such flat plates, 45 degree waffle stiffening was found to be the most effective of the configurations for the proportions considered over the widest range of combinations of compression and shear.
High-Fidelity Numerical Modeling of Compressible Flow
2015-11-01
details on these aspects of the implementation were reported in an earlier paper by Poggie.42 C. Flowfield Two flat - plate turbulent boundary layer flows...work investigated flat plate turbulent boundary layer flows. The baseline case was a flow at Mach 2.3, under conditions similar to those employed in...analyzed. The solutions are compared to a spanwise- periodic flat - plate turbulent boundary layer developed at the same conditions and yield similar
High-Accuracy Tidal Flat Digital Elevation Model Construction Using TanDEM-X Science Phase Data
NASA Technical Reports Server (NTRS)
Lee, Seung-Kuk; Ryu, Joo-Hyung
2017-01-01
This study explored the feasibility of using TanDEM-X (TDX) interferometric observations of tidal flats for digital elevation model (DEM) construction. Our goal was to generate high-precision DEMs in tidal flat areas, because accurate intertidal zone data are essential for monitoring coastal environment sand erosion processes. To monitor dynamic coastal changes caused by waves, currents, and tides, very accurate DEMs with high spatial resolution are required. The bi- and monostatic modes of the TDX interferometer employed during the TDX science phase provided a great opportunity for highly accurate intertidal DEM construction using radar interferometry with no time lag (bistatic mode) or an approximately 10-s temporal baseline (monostatic mode) between the master and slave synthetic aperture radar image acquisitions. In this study, DEM construction in tidal flat areas was first optimized based on the TDX system parameters used in various TDX modes. We successfully generated intertidal zone DEMs with 57-m spatial resolutions and interferometric height accuracies better than 0.15 m for three representative tidal flats on the west coast of the Korean Peninsula. Finally, we validated these TDX DEMs against real-time kinematic-GPS measurements acquired in two tidal flat areas; the correlation coefficient was 0.97 with a root mean square error of 0.20 m.
NASA Astrophysics Data System (ADS)
Hu, Zhan; van der Wal, Daphne; Cai, Huayang; van Belzen, Jim; Bouma, Tjeerd J.
2018-06-01
Dynamic equilibrium theory (DET) has been applied to tidal flats to systematically explain intertidal morphological responses to various distributions of bed shear stress (BSS). However, it is difficult to verify this theory with field observations because of the discrepancy between the idealized conceptions of theory and the complex reality of intertidal dynamics. The core relation between intertidal morphodynamics and BSS distribution can be easily masked by noise in complex datasets, leading to conclusions of insufficient field evidence to support DET. In the current study, hydrodynamic and morphodynamic data were monitored daily for one year on two tidal flats with contrasting wave exposures. BSS distribution was obtained by validated numerical models. Tidal flat dynamic equilibrium behaviour and BSS were linked via Empirical Orthogonal Function (EOF) analysis. We show that the principal morphodynamic modes corresponded well with the respective modes of BSS found at both sites. Tide-induced BSS was the dominant force at both sites, regardless of the level of wave exposure. The overall erosional and steepening trend found at the two flats can be attributed to the prevailing action of tidal forcing and reduced sediment supply. Hence, EOF analysis confirmed that tidal flat morphodynamics are consistent with DET, providing both field and model evidence to support this theory.
The Changes of COP and Foot Pressure after One Hour's Walking Wearing High-heeled and Flat Shoes
Ko, Dong Yeol; Lee, Han Suk
2013-01-01
[Purpose] This study aimed to determine the most appropriate height for shoe heels by measuring the displacement of the COP (center of pressure) and changes in the distribution of foot pressure after walking in flat (0.5 cm), middle-heeled (4 cm), and high-heeled (9 cm) shoes for 1 hour. [Methods] A single-subject design was used, with 15 healthy women wearing shoes with heels of each height in a random order. The foot pressure and displacement of COP before and after walking in an ordinary environment for 1 hour were measured using an FDM-S (zebris Medical GmbH, Germany). [Results] The distribution of foot pressure did not change significantly after walking in middle-heeled (4 cm) shoes but did change significantly after walking in either flat (0.5 cm) or high-heeled (9 cm) shoes. Similarly, the COP was not significantly displaced after walking in middle-heeled (4 cm) shoes but was significantly displaced after walking in either flat (0.5 cm) or high-heeled (9 cm) shoes. [Conclusion] Both flat and high-heeled shoes had adverse effects on the body. Middle-heeled (4 cm) shoes are preferable to both flat (0.5 cm) and high-heeled (9 cm) shoes for the health and comfort of the feet. PMID:24259782
APMP supplementary comparison (APMP.L-S8) measurement of flatness of optical flat by interferometry
NASA Astrophysics Data System (ADS)
Buajarern, J.; Bitou, Y.; Zi, X.; Zhao, L.; Swift, N.; Agarwal, A.; Hungwe, F.
2018-01-01
A reginal supplementary comparison, APMP.L-S8, was started in 2015 to demonstrate the equivalence of routine calibration services offered by NMIs to clients. Participants in this APMP.L-S8 comparison agreed to apply interferometric method for flatness measurement of the optical flats. There are two configurations of flatness interferometer used in this comparison, vertical type and horizontal type. There are seven laboratories from NMIs participated this supplementary comparison which included NIMT, NMIJ, NIM, NMC/A*STAR, MSL, NPLI and NMISA. This report describes the measurement results of two optical flats, diameter of 70 mm and 160 mm. The calibrations of this comparison were carried out by participants during the period from July 2015 to September 2016. The results show that there is a degree of equivalence below 1 for all measurands. Hence, there is a close agreement between the measurements from all participants. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Ito, Yoichiro; Clary, Robert
2016-01-01
High-speed countercurrent chromatography with a spiral tube assembly can retain a satisfactory amount of stationary phase of polymer phase systems used for protein separation. In order to improve the partition efficiency a simple tool to modify the tubing shapes was fabricated, and the following four different tubing modifications were made: intermittently pressed at 10 mm width, flat, flat-wave, and flat-twist. Partition efficiencies of the separation column made from these modified tubing were examined in protein separation with an aqueous-aqueous polymer phase system at flow rates of 1–2 ml/min under 800 rpm. The results indicated that the column with all modified tubing improved the partition efficiency at a flow rate of 1 ml/min, but at a higher flow rate of 2 ml/min the columns made of flattened tubing showed lowered partition efficiency apparently due to the loss of the retained stationary phase. Among all the modified columns, the column with intermittently pressed tubing gave the best peak resolution. It may be concluded that the intermittently pressed and flat-twist improve the partition efficiency in a semi-preparative separation while other modified tubing of flat and flat-wave configurations may be used for analytical separations with a low flow rate. PMID:27790621
Ito, Yoichiro; Clary, Robert
2016-12-01
High-speed countercurrent chromatography with a spiral tube assembly can retain a satisfactory amount of stationary phase of polymer phase systems used for protein separation. In order to improve the partition efficiency a simple tool to modify the tubing shapes was fabricated, and the following four different tubing modifications were made: intermittently pressed at 10 mm width, flat, flat-wave, and flat-twist. Partition efficiencies of the separation column made from these modified tubing were examined in protein separation with an aqueous-aqueous polymer phase system at flow rates of 1-2 ml/min under 800 rpm. The results indicated that the column with all modified tubing improved the partition efficiency at a flow rate of 1 ml/min, but at a higher flow rate of 2 ml/min the columns made of flattened tubing showed lowered partition efficiency apparently due to the loss of the retained stationary phase. Among all the modified columns, the column with intermittently pressed tubing gave the best peak resolution. It may be concluded that the intermittently pressed and flat-twist improve the partition efficiency in a semi-preparative separation while other modified tubing of flat and flat-wave configurations may be used for analytical separations with a low flow rate.
High sensitivity flat SiO2 fibres for medical dosimetry
NASA Astrophysics Data System (ADS)
Abdul Sani, Siti. F.; Alalawi, Amani I.; Azhar, Hairul A. R.; Amouzad Mahdiraji, Ghafour; Tamchek, Nizam; Nisbet, A.; Maah, M. J.; Bradley, D. A.
2014-11-01
We describe investigation of a novel undoped flat fibre fabricated for medical radiation dosimetry. Using high energy X-ray beams generated at a potential of 6 MV, comparison has been made of the TL yield of silica flat fibres, TLD-100 chips and Ge-doped silica fibres. The flat fibres provide competitive TL yield to that of TLD-100 chips, being some 100 times that of the Ge-doped fibres. Pt-coated flat fibres have then been used to increase photoelectron production and hence local dose deposition, obtaining significant increase in dose sensitivity over that of undoped flat fibres. Using 250 kVp X-ray beams, the TL yield reveals a progressive linear increase in dose for Pt thicknesses from 20 nm up to 80 nm. The dose enhancement factor (DEF) of (0.0150±0.0003) nm-1 Pt is comparable to that obtained using gold, agreeing at the 1% level with the value expected on the basis of photoelectron generation. Finally, X-ray photoelectron spectroscopy (XPS) has been employed to characterize the surface oxidation state of the fibre medium. The charge state of Si2p was found to lie on 103.86 eV of binding energy and the atomic percentage obtained from the XPS analysis is 22.41%.
Gravitational wave signals from short-lived topological defects in the MSSM
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kamada, Ayuki; Department of Physics and Astronomy, University of California,Riverside, CA, 92507; Yamada, Masaki
2015-10-09
Supersymmetric theories, including the minimal supersymmetric standard model, usually contain many scalar fields whose potentials are absent in the exact supersymmetric limit and within the renormalizable level. Since their potentials are vulnerable to the finite energy density of the Universe through supergravity effects, these flat directions have nontrivial dynamics in the early Universe. Recently, we have pointed out that a flat direction may have a positive Hubble induced mass term during inflation whereas a negative one after inflation. In this case, the flat direction stays at the origin of the potential during inflation and then obtain a large vacuum expectationmore » value after inflation. After that, when the Hubble parameter decreases down to the mass of the flat direction, it starts to oscillate around the origin of the potential. In this paper, we investigate the dynamics of the flat direction with and without higher dimensional superpotentials and show that topological defects, such as cosmic strings and domain walls, form at the end of inflation and disappear at the beginning of oscillation of the flat direction. We numerically calculate their gravitational signals and find that the observation of gravitational signals would give us information of supersymmetric scale, the reheating temperature of the Universe, and higher dimensional operators.« less
Gravitational wave signals from short-lived topological defects in the MSSM
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kamada, Ayuki; Yamada, Masaki, E-mail: ayuki.kamada@ucr.edu, E-mail: yamadam@icrr.u-tokyo.ac.jp
2015-10-01
Supersymmetric theories, including the minimal supersymmetric standard model, usually contain many scalar fields whose potentials are absent in the exact supersymmetric limit and within the renormalizable level. Since their potentials are vulnerable to the finite energy density of the Universe through supergravity effects, these flat directions have nontrivial dynamics in the early Universe. Recently, we have pointed out that a flat direction may have a positive Hubble induced mass term during inflation whereas a negative one after inflation. In this case, the flat direction stays at the origin of the potential during inflation and then obtain a large vacuum expectationmore » value after inflation. After that, when the Hubble parameter decreases down to the mass of the flat direction, it starts to oscillate around the origin of the potential. In this paper, we investigate the dynamics of the flat direction with and without higher dimensional superpotentials and show that topological defects, such as cosmic strings and domain walls, form at the end of inflation and disappear at the beginning of oscillation of the flat direction. We numerically calculate their gravitational signals and find that the observation of gravitational signals would give us information of supersymmetric scale, the reheating temperature of the Universe, and higher dimensional operators.« less
Contrast coating of the surface of flat polyps at CT colonography: a marker of detection
Kim, David H.; Hinshaw, J. Louis; Lubner, Meghan G.; Munoz del Rio, Alejandro; Pooler, B. Dustin; Pickhardt, Perry J.
2014-01-01
Purpose To assess the frequency of oral contrast coating of flat polyps, which may promote detection, and influencing factors within a screening CTC population. Materials From 7,426 individuals, 123 patients with 160 flat polyps were extracted. Flat polyps were defined as plaque-like, raised ≤ 3mm in height and reviewed for contrast coating. Factors including demographic variables such as age and sex, and polyp variables such as polyp size, location, and histology were analyzed for effect on coating. Results Of 160 flat polyps (mean size 9.4mm±3.6), 78.8% demonstrated coating. Mean coat thickness was 1.5mm±0.6; 23.8% (n=30), demonstrating a thin film of contrast. Large size (≥10 mm), and proximal colonic location (relative to splenic flexure) were predictive variables by univariate logistic regression [OR (odds ratio) 3.4(CI 1.3–8.9; p=0.011), 2.0(CI 1.2–3.5; p=0.011), respectively]. Adenomas (OR 0.37, CI: 0.14–1.02; p=0.054) and mucosal polyps or venous blebs (OR 0.07, CI: 0.02–0.25; p < 0.001) were less likely to coat than serrated/hyperplastic lesions. Age and sex were not predictive for coating (p=0.417, p= 0.499, respectively). Conclusions Surface contrast coating is common for flat polyps at CTC, promoted by large size, proximal location, and serrated/hyperplastic histology. Given the difficulty in detection, recognition may aid in flat polyp identification. PMID:24482303
VanDusen, Beth M.; Fegley, Stephen R.; Peterson, Charles H.
2012-01-01
Worldwide declines in shorebird populations, driven largely by habitat loss and degradation, motivate environmental managers to preserve and restore the critical coastal habitats on which these birds depend. Effective habitat management requires an understanding of the factors that determine habitat use and value to shorebirds, extending from individuals to the entire community. While investigating the factors that influenced shorebird foraging distributions among neighboring intertidal sand flats, we built upon species-level understandings of individual-based, small-scale foraging decisions to develop more comprehensive guild- and community-level insights. We found that densities and community composition of foraging shorebirds varied substantially among elevations within some tidal flats and among five flats despite their proximity (all located within a 400-m stretch of natural, unmodified inlet shoreline). Non-dimensional multivariate analyses revealed that the changing composition of the shorebird community among flats and tidal elevations correlated significantly (ρs = 0.56) with the spatial structure of the benthic invertebrate prey community. Sediment grain-sizes affected shorebird community spatial patterns indirectly by influencing benthic macroinvertebrate community compositions. Furthermore, combining sediment and macroinvertebrate information produced a 27% increase in correlation (ρs = 0.71) with shorebird assemblage patterns over the correlation of the bird community with the macroinvertebrate community alone. Beyond its indirect effects acting through prey distributions, granulometry of the flats influenced shorebird foraging directly by modifying prey availability. Our study highlights the importance of habitat heterogeneity, showing that no single patch type was ideal for the entire shorebird community. Generally, shorebird density and diversity were greatest at lower elevations on flats when they became exposed; these areas are at risk from human intervention by inlet sand mining, construction of groins and jetties that divert sediments from flats, and installation of seawalls on inlet shorelines that induce erosion of flats. PMID:23285153
Circles-in-the-sky searches and observable cosmic topology in a flat universe
NASA Astrophysics Data System (ADS)
Mota, B.; Rebouças, M. J.; Tavakol, R.
2010-05-01
In a universe with a detectable nontrivial spatial topology, the last scattering surface contains pairs of matching circles with the same distribution of temperature fluctuations—the so-called circles-in-the-sky. Searches for nearly antipodal circles-in-the-sky in maps of cosmic microwave background radiation have so far been unsuccessful. This negative outcome, along with recent theoretical results concerning the detectability of nearly flat compact topologies, is sufficient to exclude a detectable nontrivial topology for most observers in very nearly flat positively and negatively curved universes, whose total matter-energy density satisfies 0<|Ωtot-1|≲10-5. Here, we investigate the consequences of these searches for observable nontrivial topologies if the Universe turns out to be exactly flat (Ωtot=1). We demonstrate that in this case, the conclusions deduced from such searches can be radically different. We show that, although there is no characteristic topological scale in the flat manifolds, for all multiply-connected orientable flat manifolds, it is possible to directly study the action of the holonomies in order to obtain a general upper bound on the angle that characterizes the deviation from antipodicity of pairs of matching circles associated with the shortest closed geodesic. This bound is valid for all observers and all possible values of the compactification length parameters. We also show that in a flat universe, there are observers for whom the circles-in-the-sky searches already undertaken are insufficient to exclude the possibility of a detectable nontrivial spatial topology. It is remarkable how such small variations in the spatial curvature of the Universe, which are effectively indistinguishable geometrically, can have such a drastic effect on the detectability of cosmic topology. Another important outcome of our results is that they offer a framework with which to make statistical inferences from future circles-in-the-sky searches on whether the Universe is exactly flat.
Machining of Silicon-Ribbon-Forming Dies
NASA Technical Reports Server (NTRS)
Menna, A. A.
1985-01-01
Carbon extension for dies used in forming silicon ribbon crystals machined precisely with help of special tool. Die extension has edges beveled toward narrow flats at top, with slot precisely oriented and centered between flats and bevels. Cutting tool assembled from standard angle cutter and circular saw or saws. Angle cutters cuts bevels while slot saw cuts slot between them. In alternative version, custom-ground edges or additional circular saws also cut flats simultaneously.
Flat panel ferroelectric electron emission display system
Sampayan, Stephen E.; Orvis, William J.; Caporaso, George J.; Wieskamp, Ted F.
1996-01-01
A device which can produce a bright, raster scanned or non-raster scanned image from a flat panel. Unlike many flat panel technologies, this device does not require ambient light or auxiliary illumination for viewing the image. Rather, this device relies on electrons emitted from a ferroelectric emitter impinging on a phosphor. This device takes advantage of a new electron emitter technology which emits electrons with significant kinetic energy and beam current density.
Turbulent Combustion Study of Scramjet Problem
2015-08-01
boundary layer model for 2D simulations of a supersonic flat plate boundary layer . The inflow O2 has an average density of...flow above the flat plate has a transition from a laminar boundary layer to a turbulent boundary layer at a position downstream from the inlet. The...δ. Chapman [13] estimated the number of cells need to resolve the outer layer is proportional to Re0.4 for flat plat boundary layer and
Airborne Aero-Optics Laboratory - Transonic (AAOL-T)
2016-10-03
122–151. [30] DeGraaff, D. B. and Eaton, J. K., “Reynolds-Number Scaling of the Flat - Plate Turbulent Boundary Layer ,” Journal of Fluid Mechanics, Vol...elevation angle of the turret is fixed at 120 o . The inflow turbulence data are generated by a separate flat - plate boundary layers simulation. The...aero-optical distortion magnitude for turbulent boundary layers . Subsonic Flow over a Cylindrical Turret with a Flat Window. The flow over a
NASA Astrophysics Data System (ADS)
Liu, X.; Currie, C. A.
2017-12-01
The subducted Farallon plate is believed to have evolved to a flat geometry underneath North America plate during Late Cretaceous, triggering Laramide deformation within the continental interior. However, the mechanism that caused the oceanic slab to flatten and the factors that control the flat-slab depth remain uncertain. In this work, we use 2D thermal-mechanical models using the SOPALE code to study the subduction dynamics from 90 Ma to 50 Ma. During this period, an oceanic plateau (Shatsky Conjugate) is inferred to have subducted beneath western North America and interacted with the continental lithosphere, including areas of thicker lithosphere such as the Colorado Plateau and Wyoming Craton. Based on seismic tomography and plate reconstruction data sets, we built a set of models to examine the influence of the structure and rheology of the oceanic and continental plates on slab dynamics. Models include a 600 km wide oceanic plateau consisting of 18 km thick crust and a 36 km thick underlying harzburgite layer, and we ran a series of model experiments to test different continental thicknesses (80 km, 120 km, & 180 km) and continental mantle lithosphere strengths (approximating conditions from wet olivine to dry olivine). Consistent with earlier studies, we find that creation of a long flat slab requires a buoyant oceanic plateau (i.e., non-eclogitized crust) and trenchward motion of the continent. In addition, our models demonstrate the upper plate has an important control on slab dynamics. A flat slab requires either a thin continent or, if the continent is thick, its mantle lithosphere must be relatively weak so that it can be displaced by the flattening slab. The depth of the flat slab is mainly controlled by two factors: (1) the continental thickness and (2) the strength of the continental mantle lithosphere. For the same initial lithosphere thickness (120 km), a shallower flat slab ( 90 km depth) occurs for the weakest mantle lithosphere ( wet olivine) compared to 120 km depth for strong ( dry) mantle lithosphere because the flat slab removes the lowermost weak lithosphere. Moreover, an even deeper slab ( 130 km) can be found underneath the weakest but thicker continental lithosphere (180 km). Future models will focus on how the flat slab may induce hydration and deformation for the overriding continental plate.
NASA Astrophysics Data System (ADS)
Chen, Xiaowei; Wang, Wenping; Wan, Min
2013-12-01
It is essential to calculate magnetic force in the process of studying electromagnetic flat sheet forming. Calculating magnetic force is the basis of analyzing the sheet deformation and optimizing technical parameters. Magnetic force distribution on the sheet can be obtained by numerical simulation of electromagnetic field. In contrast to other computing methods, the method of numerical simulation has some significant advantages, such as higher calculation accuracy, easier using and other advantages. In this paper, in order to study of magnetic force distribution on the small size flat sheet in electromagnetic forming when flat round spiral coil, flat rectangular spiral coil and uniform pressure coil are adopted, the 3D finite element models are established by software ANSYS/EMAG. The magnetic force distribution on the sheet are analyzed when the plane geometries of sheet are equal or less than the coil geometries under fixed discharge impulse. The results showed that when the physical dimensions of sheet are less than the corresponding dimensions of the coil, the variation of induced current channel width on the sheet will cause induced current crowding effect that seriously influence the magnetic force distribution, and the degree of inhomogeneity of magnetic force distribution is increase nearly linearly with the variation of induced current channel width; the small size uniform pressure coil will produce approximately uniform magnetic force distribution on the sheet, but the coil is easy to early failure; the desirable magnetic force distribution can be achieved when the unilateral placed flat rectangular spiral coil is adopted, and this program can be take as preferred one, because the longevity of flat rectangular spiral coil is longer than the working life of small size uniform pressure coil.
Optimal flapping wing for maximum vertical aerodynamic force in hover: twisted or flat?
Phan, Hoang Vu; Truong, Quang Tri; Au, Thi Kim Loan; Park, Hoon Cheol
2016-07-08
This work presents a parametric study, using the unsteady blade element theory, to investigate the role of twist in a hovering flapping wing. For the investigation, a flapping-wing system was developed to create a wing motion of large flapping amplitude. Three-dimensional kinematics of a passively twisted wing, which is capable of creating a linearly variable geometric angle of attack (AoA) along the wingspan, was measured during the flapping motion and used for the analysis. Several negative twist or wash-out configurations with different values of twist angle, which is defined as the difference in the average geometric AoAs at the wing root and the wing tip, were obtained from the measured wing kinematics through linear interpolation and extrapolation. The aerodynamic force generation and aerodynamic power consumption of these twisted wings were obtained and compared with those of flat wings. For the same aerodynamic power consumption, the vertical aerodynamic forces produced by the negatively twisted wings are approximately 10%-20% less than those produced by the flat wings. However, these twisted wings require approximately 1%-6% more power than flat wings to produce the same vertical force. In addition, the maximum-force-producing twisted wing, which was found to be the positive twist or wash-in configuration, was used for comparison with the maximum-force-producing flat wing. The results revealed that the vertical aerodynamic force and aerodynamic power consumption of the two types of wings are almost identical for the hovering condition. The power loading of the positively twisted wing is only approximately 2% higher than that of the maximum-force-producing flat wing. Thus, the flat wing with proper wing kinematics (or wing rotation) can be regarded as a simple and efficient candidate for the development of hovering flapping-wing micro air vehicle.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hakan Ozaltun; Pavel Medvedev
The effects of the foil flatness on stress-strain behavior of monolithic fuel mini-plates during fabrication and irradiation were studied. Monolithic plate-type fuels are a new fuel form being developed for research and test reactors to achieve higher uranium densities. This concept facilitates the use of low-enriched uranium fuel in the reactor. These fuel elements are comprised of a high density, low enrichment, U–Mo alloy based fuel foil encapsulated in a cladding material made of Aluminum. To evaluate the effects of the foil flatness on the stress-strain behavior of the plates during fabrication, irradiation and shutdown stages, a representative plate frommore » RERTR-12 experiments (Plate L1P756) was considered. Both fabrication and irradiation processes of the plate were simulated by using actual irradiation parameters. The simulations were repeated for various foil curvatures to observe the effects of the foil flatness on the peak stress and strain magnitudes of the fuel elements. Results of fabrication simulations revealed that the flatness of the foil does not have a considerable impact on the post fabrication stress-strain fields. Furthermore, the irradiation simulations indicated that any post-fabrication stresses in the foil would be relieved relatively fast in the reactor. While, the perfectly flat foil provided the slightly better mechanical performance, overall difference between the flat-foil case and curved-foil case was not significant. Even though the peak stresses are less affected, the foil curvature has several implications on the strain magnitudes in the cladding. It was observed that with an increasing foil curvature, there is a slight increase in the cladding strains.« less
Development and application of W/Cu flat-type plasma facing components at ASIPP
NASA Astrophysics Data System (ADS)
Li, Q.; Zhao, S. X.; Sun, Z. X.; Xu, Y.; Li, B.; Wei, R.; Wang, W. J.; Qin, S. G.; Shi, Y. L.; Xie, C. Y.; Wang, J. C.; Wang, X. L.; Missirlian, M.; Guilhem, D.; Liu, G. H.; Yang, Z. S.; Luo, G.-N.
2017-12-01
W/Cu flat-type plasma facing components (PFCs) were widely used in divertor of fusion device because of its advantages, such as low cost, light in weight and good machinability. However, it is very difficult to manufacture them due to the large mismatch between the thermo-mechanical properties of W and Cu. Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) has successfully developed W/Cu flat-type PFCs for EAST W/Cu divertor project by hot isostatic pressing (HIP) technology. This paper presents the development and application of W/Cu flat-type PFCs at ASIPP. The optimized manufacturing process is to cast pure copper onto the rear side of W tiles at temperature of 1200 °C firstly, and then to HIP the W/Cu tiles onto CuCrZr heat sink at temperature of 600 °C, pressure of 150 MPa and duration of 3 h. W/Cu flat-type testing mock-up for EAST survived 1000 cycles at heat load of 5 MW m-2 in high heat flux tests. And then ASIPP prepared two mock-ups for CEA’s tungsten environment in steady-state tokamak (WEST) project. One mock-up withstood successfully 302 cycles of 20 MW m-2, which are far beyond the design requirement. Since 2014, W/Cu flat-type PFCs were wildly used in EAST upper divertor as baffle and dome components which showed excellent performance in 2015 and 2016 campaigns. Given the success in EAST upper divertor, W/Cu flat-type concept is as well applied in the design of actively cooled Langmuir probes which will be mounted onto EAST divertor targets soon.
Saddle-shaped mitral valve annuloplasty rings experience lower forces compared with flat rings.
Jensen, Morten O; Jensen, Henrik; Smerup, Morten; Levine, Robert A; Yoganathan, Ajit P; Nygaard, Hans; Hasenkam, J Michael; Nielsen, Sten L
2008-09-30
New insight into the 3D dynamic behavior of the mitral valve has prompted a reevaluation of annuloplasty ring designs. Force balance analysis indicates correlation between annulus forces and stresses in leaflets and chords. Improving this stress distribution can intuitively enhance the durability of mitral valve repair. We tested the hypothesis that saddle-shaped annuloplasty rings have superior uniform systolic force distribution compared with a nonuniform force distribution in flat annuloplasty rings. Sixteen 80-kg pigs had a flat (n=8) or saddle-shaped (n=8) mitral annuloplasty ring implanted. Mitral annulus 3D dynamic geometry was obtained with sonomicrometry before ring insertion. Strain gauges mounted on dedicated D-shaped rigid flat and saddle-shaped annuloplasty rings provided the intraoperative force distribution perpendicular to the annular plane. Average systolic annular height to commissural width ratio before ring implantation was 14.0%+/-1.6%. After flat and saddle shaped ring implantation, the annulus was fixed in the diastolic (9.0%+/-1.0%) and systolic (14.3%+/-1.3%) configuration, respectively (P<0.01). Force accumulation was seen from the anterior (0.72N+/-0.14N) and commissural annular segments (average 1.38N+/-0.27N) of the flat rings. In these segments, the difference between the 2 types of rings was statistically significant (P<0.05). The saddle-shaped annuloplasty rings did not experience forces statistically significantly larger than zero in any annular segments. Saddle-shaped annuloplasty rings provide superior uniform annular force distribution compared to flat rings and appear to represent a configuration that minimizes out-of-plane forces that could potentially be transmitted to leaflets and chords. This may have important implications for annuloplasty ring selections.
Modeling of the rough spherical nanoparticles manipulation on a substrate based on the AFM nanorobot
NASA Astrophysics Data System (ADS)
Zakeri, M.; Faraji, J.
2014-12-01
In this paper, dynamic behavior of the rough spherical micro/nanoparticles during pulling/pushing on the flat substrate has been investigated and analyzed. For this purpose, at first, two hexagonal roughness models (George and Cooper) were studied and then evaluations for adhesion force were determined for rough particle manipulation on flat substrate. These two models were then changed by using of the Rabinovich theory. Evaluations were determined for contact adhesion force between rough particle and flat substrate; depth of penetration evaluations were determined by the Johnson-Kendall-Roberts contact mechanic theory and the Schwartz method and according to Cooper and George roughness models. Then, the novel contact theory was used to determine a dynamic model for rough micro/nanoparticle manipulation on flat substrate. Finally, simulation of particle dynamic behavior was implemented during pushing of rough spherical gold particles with radii of 50, 150, 400, 600, and 1,000 nm. Results derived from simulations of particles with several rates of roughness on flat substrate indicated that compared to results for flat particles, inherent roughness on particles might reduce the rate of critical force needed for sliding and rolling given particles. Given a fixed radius for roughness value and increased roughness height, evaluations for sliding and rolling critical forces showed greater reduction. Alternately, the rate of critical force was shown to reduce relative to an increased roughness radius. With respect to both models, based on the George roughness model, the predicted rate of adhesion force was greater than that determined in the Cooper roughness model, and as a result, the predicted rate of critical force based on the George roughness model was closer to the critical force value of flat particle.
Radiation dose reduction in chest radiography using a flat-panel amorphous silicon detector.
Hosch, W P; Fink, C; Radeleff, B; kampschulte a, A; Kauffmann, G W; Hansmann, J
2002-10-01
The aim of this study was to evaluate the image quality and the potential for radiation dose reduction with a digital flat-panel amorphous silicon detector radiography system. Using flat-panel technology, radiographs of an anthropomorphic thorax phantom were taken with a range of technical parameters (125kV, 200mA and 5, 4, 3.2, 2, 1, 0.5, and 0.25mAs) which were equivalent to a radiation dose of 332, 263, 209, 127, 58.7, 29, and 14 microGy, respectively. These images were compared to radiographs obtained by a conventional film-screen radiography system at 125kV, 200mA and 5mAs (equivalent to 252 microGy) which served as reference. Three observers evaluated independently the visibility of simulated rounded lesions and anatomical structures, comparing printed films from the flat-panel amorphous silicon detector and conventional x-ray system films. With flat-panel technology, the visibility of rounded lesions and normal anatomical structures at 5, 4, and 3.2mAs was superior compared to the conventional film-screen radiography system. (P< or =0.0001). At 2mAs, improvement was only marginal (P=0.19). At 1.0, 0.5 and 0.25mAs, the visibility of simulated rounded lesions was worse (P< or =0.004). Comparing fine lung parenchymal structures, the flat-panel amorphous silicon detector showed improvement for all exposure levels down to 2mAs and equality at 1mAs. Compared to a conventional x-ray film system, the flat-panel amorphous silicon detector demonstrated improved image quality and the possibility for a reduction of the radiation dose by 50% without loss in image quality.
Wave Dissipation on Low- to Super-Energy Coral Reefs
NASA Astrophysics Data System (ADS)
Harris, D. L.
2016-02-01
Coral reefs are valuable, complex and bio-diverse ecosystems and are also known to be one of the most effective barriers to swell events in coastal environments. Previous research has found coral reefs to be remarkably efficient in removing most of the wave energy during the initial breaking and transformation on the reef flats. The rate of dissipation is so rapid that coral reefs have been referred to as rougher than any known coastal barrier. The dissipation of wave energy across reef flats is crucial in maintaining the relatively low-energy conditions in the back reef and lagoonal environments providing vital protection to adjacent beach or coastal regions from cyclone and storm events. A shift in the regulation of wave energy by reef flats could have catastrophic consequences ecologically, socially, and economically. This study examined the dissipation of wave energy during two swell events in Tahiti and Moorea, French Polyesia. Field sites were chosen in varying degrees of exposure and geomorphology from low-energy protected sites (Tiahura, Moorea) to super-energy sites (Teahupo'o, Tahiti). Waves were measured during two moderate to large swell events in cross reef transects using short-term high-resolution pressure transducers. Wave conditions were found to be similar in all back reef locations despite the very different wave exposure at each reef site. However, wave conditions on the reef flats were different and mirrored the variation in wave exposure with depth over the reef flat the primary regulator of reef flat wave height. These results indicate that coral reef flats evolve morphodynamically with the wave climate, which creates coral reef geomorphologies capable of dissipating wave energy that results in similar back reef wave conditions regardless of the offshore wave climate.
Storlazzi, C.D.; Elias, E.; Field, M.E.; Presto, M.K.
2011-01-01
Most climate projections suggest that sea level may rise on the order of 0.5-1.0 m by 2100; it is not clear, however, how fluid flow and sediment dynamics on exposed fringing reefs might change in response to this rapid sea-level rise. Coupled hydrodynamic and sediment-transport numerical modeling is consistent with recent published results that suggest that an increase in water depth on the order of 0.5-1.0 m on a 1-2 m deep exposed fringing reef flat would result in larger significant wave heights and setup, further elevating water depths on the reef flat. Larger waves would generate higher near-bed shear stresses, which, in turn, would result in an increase in both the size and the quantity of sediment that can be resuspended from the seabed or eroded from adjacent coastal plain deposits. Greater wave- and wind-driven currents would develop with increasing water depth, increasing the alongshore and offshore flux of water and sediment from the inner reef flat to the outer reef flat and fore reef where coral growth is typically greatest. Sediment residence time on the fringing reef flat was modeled to decrease exponentially with increasing sea-level rise as the magnitude of sea-level rise approached the mean water depth over the reef flat. The model results presented here suggest that a 0.5-1.0 m rise in sea level will likely increase coastal erosion, mixing and circulation, the amount of sediment resuspended, and the duration of high turbidity on exposed reef flats, resulting in decreased light availability for photosynthesis, increased sediment-induced stress on the reef ecosystem, and potentially affecting a number of other ecological processes.
System for photometric calibration of optoelectronic imaging devices especially streak cameras
Boni, Robert; Jaanimagi, Paul
2003-11-04
A system for the photometric calibration of streak cameras and similar imaging devices provides a precise knowledge of the camera's flat-field response as well as a mapping of the geometric distortions. The system provides the flat-field response, representing the spatial variations in the sensitivity of the recorded output, with a signal-to-noise ratio (SNR) greater than can be achieved in a single submicrosecond streak record. The measurement of the flat-field response is carried out by illuminating the input slit of the streak camera with a signal that is uniform in space and constant in time. This signal is generated by passing a continuous wave source through an optical homogenizer made up of a light pipe or pipes in which the illumination typically makes several bounces before exiting as a spatially uniform source field. The rectangular cross-section of the homogenizer is matched to the usable photocathode area of the streak tube. The flat-field data set is obtained by using a slow streak ramp that may have a period from one millisecond (ms) to ten seconds (s), but may be nominally one second in duration. The system also provides a mapping of the geometric distortions, by spatially and temporarily modulating the output of the homogenizer and obtaining a data set using the slow streak ramps. All data sets are acquired using a CCD camera and stored on a computer, which is used to calculate all relevant corrections to the signal data sets. The signal and flat-field data sets are both corrected for geometric distortions prior to applying the flat-field correction. Absolute photometric calibration is obtained by measuring the output fluence of the homogenizer with a "standard-traceable" meter and relating that to the CCD pixel values for a self-corrected flat-field data set.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gao Song; Balter, Peter A.; Rose, Mark
2013-04-15
Purpose: To compare the use of flatness versus percent depth dose (PDD) for determining changes in photon beam energy for a megavoltage linear accelerator. Methods: Energy changes were accomplished by adjusting the bending magnet current by up to {+-}15% in 5% increments away from the value used clinically. Two metrics for flatness, relative flatness in the central 80% of the field (Flat) and average maximum dose along the diagonals normalized by central axis dose (F{sub DN}), were measured using a commercially available planner ionization chamber array. PDD was measured in water at depths of 5 and 10 cm in 3more » Multiplication-Sign 3 cm{sup 2} and 10 Multiplication-Sign 10 cm{sup 2} fields using a cylindrical chamber. Results: PDD was more sensitive to changes in energy when the beam energy was increased than when it was decreased. For the 18-MV beam in particular, PDD was not sensitive to energy reductions below the nominal energy. The value of Flat was found to be more sensitive to decreases in energy than to increases, with little sensitivity to energy increases above the nominal energy for 18-MV beams. F{sub DN} was the only metric that was found to be sensitive to both increases and reductions of energy for both the 6- and 18-MV beams. Conclusions: Flatness based metrics were found to be more sensitive to energy changes than PDD, In particular, F{sub DN} was found to be the most sensitive metric to energy changes for photon beams of 6 and 18 MV. The ionization chamber array allows this metric to be conveniently measured as part of routine accelerator quality assurance.« less
Phelps, Geoffrey A.; McKee, Edwin H.; Sweetkind, D.; Langenheim, V.E.
2000-01-01
The Environmental Restoration Program of the U.S. Department of Energy, Nevada Operations Office, was developed to investigate the possible consequences to the environment of 40 years of nuclear testing on the Nevada Test Site. The majority of the tests were detonated underground, introducing contaminants into the ground-water system (Laczniak and others, 1996). An understanding of the ground-water flow paths is necessary to evaluate the extent of ground-water contamination. This report provides information specific to Yucca Flat on the Nevada Test Site. Critical to understanding the ground-water flow beneath Yucca Flat is an understanding of the subsurface geology, particularly the structure and distribution of the pre-Tertiary rocks, which comprise both the major regional aquifer and aquitard sequences (Winograd and Thordarson, 1975; Laczniak and others, 1996). Because the pre-Tertiary rocks are not exposed at the surface of Yucca Flat their distribution must be determined through well logs and less direct geophysical methods such as potential field studies. In previous studies (Phelps and others, 1999; Phelps and Mckee, 1999) developed a model of the basement surface of the Paleozoic rocks beneath Yucca Flat and a series of normal faults that create topographic relief on the basement surface. In this study the basement rocks and structure of Yucca Flat are examined in more detail using the basement gravity anomaly derived from the isostatic gravity inversion model of Phelps and others (1999) and high-resolution magnetic data, as part of an effort to gain a better understanding of the Paleozoic rocks beneath Yucca Flat in support of groundwater modeling.
Three-Dimensional Shear Wave Velocity Structure of the Peru Flat Slab Subduction Segment
NASA Astrophysics Data System (ADS)
Knezevic Antonijevic, S.; Wagner, L. S.; Beck, S. L.; Zandt, G.; Long, M. D.
2012-12-01
Recent studies focused on flat slab subduction segments in central Chile (L. S. Wagner, 2006) and Alaska (B. R. Hacker and G. A. Aber, 2012) suggest significant differences in seismic velocity structures, and hence, composition in the mantle wedge between flat and normal "steep" subducting slabs. Instead of finding the low velocities and high Vp/Vs ratios common in normal subduction zones, these studies find low Vp, high Vs, and very low Vp/Vs above flat slabs. This may indicate the presence of dry, cold material in the mantle wedge. In order to investigate the seismic velocities of the upper mantle above the Peruvian flat segment, we have inverted for 2D Rayleigh wave phase velocity maps using data from the currently deployed 40 station PULSE seismic network and some adjacent stations from the CAUGHT seismic network. We then used the sensitivity of surface waves to shear wave velocity structure with depth to develop a 3D shear wave velocity model. This model will allow us to determine the nature of the mantle lithosphere above the flat slab, and how this may have influenced the development of local topography. For example, dry conditions (high Vs velocities) above the flat slab would imply greater strength of this material, possibly making it capable of causing further inland overthrusting, while wet conditions (low Vs) would imply weaker material. This could provide some insight into the ongoing debate over whether the Fitzcarrald arch (along the northern most flank of the Altiplano) could be a topographical response to the subducted Nazca ridge hundred kilometers away from the trench (N. Espurt, 2012, P. Baby, 2005, V. A. Ramos, 2012) or not (J. Martinod, 2005, M. Wipf, 2008, T. Gerya, 2008).
Exit Presentation: Infrared Thermography on Graphite/Epoxy
NASA Technical Reports Server (NTRS)
Comeaux, Kayla
2010-01-01
This slide presentation reports on the internship project that was accomplished during the summer of 2010. The objectives of the project were to: (1) Simulate Flash Thermography on Graphite/Epoxy Flat Bottom hole Specimen and thin void specimens, (2) Obtain Flash Thermography data on Graphite/Epoxy flat bottom hole specimens, (3) Compare experimental results with simulation results, Compare Flat Bottom Hole Simulation with Thin Void Simulation to create a graph to determine size of IR Thermography detected defects
25. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING WEST ...
25. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING WEST - NORTHWEST IN 1974. IN 1972, 4,600 ACRES WERE PURCHASED AROUND THE SITE TO BETTER PROTECT THE BORDERS FROM TERRORISM AND INFILTRATION BY PROTESTORS. ANTI-NUCLEAR DEMONSTRATION BEGAN SHORTLY AFTER THE 1969 FIRE IN BUILDING 776/777, AND CONTINUED UNTIL PRODUCTION CEASED AT THE PLANT IN 1989 (10/7/74). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO
A flat spectral Faraday filter for sodium lidar.
Yang, Yong; Cheng, Xuewu; Li, Faquan; Hu, Xiong; Lin, Xin; Gong, Shunsheng
2011-04-01
We report a flat spectral Faraday anomalous dispersion optical filter (FS-FADOF) for sodium lidar. The physical and technical considerations for obtaining a FS-FADOF with a 3.5 GHz flat spectral transmission function are presented. It was found that the effective transmission of this filter was much higher (>94%) and more uniform than that of the ultranarrowband FADOF, and therefore were less sensitive to laser-frequency drift. Thus, the FS-FADOF can improve lidar efficiency and precision.
Liu, Chuyu [Newport News, VA; Zhang, Shukui [Yorktown, VA
2011-10-04
A single lens bullet-shaped laser beam shaper capable of redistributing an arbitrary beam profile into any desired output profile comprising a unitary lens comprising: a convex front input surface defining a focal point and a flat output portion at the focal point; and b) a cylindrical core portion having a flat input surface coincident with the flat output portion of the first input portion at the focal point and a convex rear output surface remote from the convex front input surface.
Boundary-Layer Bypass Transition Over Large-Scale Bodies
2016-12-16
shape of the streamwise velocity profile compared to the flat- plate boundary layer. The research showed that the streamwise wavenumber plays a key role...many works on the suppression of the transitional boundary layer. Most of the results in the literature are for the flat- plate boundary layer but the...behaviour of the velocity and pressure changes with the curvature. This work aims to extend the results of the flat- plate boundary layer to a Rankine
Flat panel ferroelectric electron emission display system
Sampayan, S.E.; Orvis, W.J.; Caporaso, G.J.; Wieskamp, T.F.
1996-04-16
A device is disclosed which can produce a bright, raster scanned or non-raster scanned image from a flat panel. Unlike many flat panel technologies, this device does not require ambient light or auxiliary illumination for viewing the image. Rather, this device relies on electrons emitted from a ferroelectric emitter impinging on a phosphor. This device takes advantage of a new electron emitter technology which emits electrons with significant kinetic energy and beam current density. 6 figs.
The effect of a scanning flat fold mirror on a cosmic microwave background B-mode experiment.
Grainger, William F; North, Chris E; Ade, Peter A R
2011-06-01
We investigate the possibility of using a flat-fold beam steering mirror for a cosmic microwave background B-mode experiment. An aluminium flat-fold mirror is found to add ∼0.075% polarization, which varies in a scan synchronous way. Time-domain simulations of a realistic scanning pattern are performed, and the effect on the power-spectrum illustrated, and a possible method of correction applied. © 2011 American Institute of Physics
Numerical compliance testing of human exposure to electromagnetic radiation from smart-watches.
Hong, Seon-Eui; Lee, Ae-Kyoung; Kwon, Jong-Hwa; Pack, Jeong-Ki
2016-10-07
In this study, we investigated the electromagnetic dosimetry for smart-watches. At present, the standard for compliance testing of body-mounted and handheld devices specifies the use of a flat phantom to provide conservative estimates of the peak spatial-averaged specific absorption rate (SAR). This means that the estimated SAR using a flat phantom should be higher than the SAR in the exposure part of an anatomical human-body model. To verify this, we numerically calculated the SAR for a flat phantom and compared it with the numerical calculation of the SAR for four anatomical human-body models of different ages. The numerical analysis was performed using the finite difference time domain method (FDTD). The smart-watch models were used in the three antennas: the shorted planar inverted-F antenna (PIFA), loop antenna, and monopole antenna. Numerical smart-watch models were implemented for cellular commutation and wireless local-area network operation at 835, 1850, and 2450 MHz. The peak spatial-averaged SARs of the smart-watch models are calculated for the flat phantom and anatomical human-body model for the wrist-worn and next to mouth positions. The results show that the flat phantom does not provide a consistent conservative SAR estimate. We concluded that the difference in the SAR results between an anatomical human-body model and a flat phantom can be attributed to the different phantom shapes and tissue structures.
Numerical compliance testing of human exposure to electromagnetic radiation from smart-watches
NASA Astrophysics Data System (ADS)
Hong, Seon-Eui; Lee, Ae-Kyoung; Kwon, Jong-Hwa; Pack, Jeong-Ki
2016-10-01
In this study, we investigated the electromagnetic dosimetry for smart-watches. At present, the standard for compliance testing of body-mounted and handheld devices specifies the use of a flat phantom to provide conservative estimates of the peak spatial-averaged specific absorption rate (SAR). This means that the estimated SAR using a flat phantom should be higher than the SAR in the exposure part of an anatomical human-body model. To verify this, we numerically calculated the SAR for a flat phantom and compared it with the numerical calculation of the SAR for four anatomical human-body models of different ages. The numerical analysis was performed using the finite difference time domain method (FDTD). The smart-watch models were used in the three antennas: the shorted planar inverted-F antenna (PIFA), loop antenna, and monopole antenna. Numerical smart-watch models were implemented for cellular commutation and wireless local-area network operation at 835, 1850, and 2450 MHz. The peak spatial-averaged SARs of the smart-watch models are calculated for the flat phantom and anatomical human-body model for the wrist-worn and next to mouth positions. The results show that the flat phantom does not provide a consistent conservative SAR estimate. We concluded that the difference in the SAR results between an anatomical human-body model and a flat phantom can be attributed to the different phantom shapes and tissue structures.
Comparison of thermoluminescence response of different sized Ge-doped flat fibers as a dosimeter
NASA Astrophysics Data System (ADS)
Begum, Mahfuza; Mizanur Rahman, A. K. M.; Abdul-Rashid, H. A.; Yusoff, Z.; Mat-Sharif, K. A.; Zulkifli, M. I.; Muhamad-Yasin, S. Z.; Ung, N. M.; Kadir, A. B. A.; Amin, Y. M.; Bradley, D. A.
2015-11-01
Prime dosimetric properties, including dose-response, linearity with dose, energy response, fading and threshold doses were investigated for three different dimension Ge-doped flat fibers. The results of measurement were also compared with two of the more commonly used standard TLD media, TLD-100 (LiF:Mg,Ti-7.5%6LiF) and TLD-700 (7LiF:Mg,Ti-99.9%7LiF) chips. The flat cross-section samples (60×180) μm2, (100×350) μm2 and (200×750) μm2 were fabricated using the Modified Chemical Vapor Deposition (MCVD) process and pulled from the same "preform." In the study, all flat fiber samples provided good linear dose-response for the photon and electron beams generated using a medical linear accelerator (LINAC), for doses in the range 0.5-8 Gy. Among the samples, the smallest dimension flat fiber provided the best response, with a sensitivity of some 61% and 54%, respectively of that of the TLD-100 and TLD-700 chips. The energy responses of the samples were studied for various photon (6 MV, 10 MV) and electron (6 MeV, 9 MeV) beam energies. TL fading of around 20% was observed over a period of thirty (30) days. These favorable TL characteristics point towards promising development of Ge-doped flat fibers for use in radiotherapy dosimetry.
Face specificity and the role of metal adatoms in molecular reorientation at surfaces
NASA Astrophysics Data System (ADS)
Perry, C. C.; Haq, S.; Frederick, B. G.; Richardson, N. V.
1998-07-01
Using reflection absorption infrared spectroscopy (RAIRS), the coverage-dependent reorientation of the benzoate species on the (110) and (111) faces of copper is compared and contrasted. Whereas on Cu(110) benzoate reorients from a flat-lying to an upright orientation with increasing coverage, on Cu(111), at all coverages, benzoate is aligned normal to the surface. The formation of periodic, flat-lying copper-benzoate structures has been attributed to the availability of metal adatoms, which differs dramatically between the (111) and (110) faces. We discuss the face specificity of molecular orientation by comparing calculated formation energies of adatom vacancies from ledges and kink sites on (100), (110) and (111) faces. Further support for this model is given by the evaporation of sodium, either by pre- or post-dosing, onto low-coverage benzoate/Cu(111), which induces benzoate to convert from a perpendicular to a parallel orientation. Likewise, coevaporation of Cu while dosing benzoic acid onto the Cu(111) surface also results in a majority of flat-lying benzoate species. Finally, for adsorption on the p(2×1)O/Cu(110) reconstruction, benzoate occurs only as the upright species, which is consistent with reducing the copper mobility and availability on the (110) face. We therefore suggest the possible role of metal adatoms as a new mechanism in controlling adsorbate orientation and therefore face specificity in surface reactions.
Glycolic acid 15% plus salicylic acid 2%: a new therapeutic pearl for facial flat warts.
Rodríguez-Cerdeira, Carmen; Sánchez-Blanco, Elena
2011-09-01
Facial flat warts are a contagious viral disease that can cause disturbing cosmetic problems. Topical glycolic acid has been reported to be effective in dermatological treatment depending on the exfoliant capacity, but has not often been reported to be effective in the treatment of facial flat warts. The aim of this paper was to evaluate the efficacy and safety of glycolic acid 15% topical gel plus salicylic acid 2% in the treatment of recalcitrant facial flat warts. A total of 20 consecutive patients 7 to 16 years of age with recalcitrant facial flat warts were enrolled in this study. Patients having warts by the eye and lip regions were excluded from the study. A fine layer of face gel was applied to the treatment area once daily. Most of the participants had tried different treatments with no success. Assessments for the response and the occurrence of side effects were performed every two weeks at Weeks 2, 4, 6, and 8. All the patients were clinically cured within eight weeks. Seven patients cleared in four weeks, and 13 patients cleared in eight weeks. No noticeable adverse events were related to the skin. Topical gel of glycolic acid 15% plus salicylic acid 2% is safe and effective when applied to facial flat warts once daily until clearance and may be considered as first-line treatment.
NASA Astrophysics Data System (ADS)
Wiberg, Patricia L.; Law, Brent A.; Wheatcroft, Robert A.; Milligan, Timothy G.; Hill, Paul S.
2013-06-01
Measurements of erodibility, porosity and sediment size were made three times over the course of a year at sites within a muddy, mesotidal flat-channel complex in southern Willapa Bay, WA, to examine spatial and seasonal variations in sediment properties and transport potential. Average critical shear stress profiles, the metric we used for erodibility, were quantified using a power-law fit to cumulative eroded mass vs. shear stress for the flats and channel. Laboratory erosion measurements of deposits made from slurries of flat and channel sediment were used to quantify erodibility over consolidation time scales ranging from 6 to 96h. Erodibility of the tidal flats was consistently low, with spatial variability comparable to seasonal variability despite seasonal changes in biological activity. In contrast, channel-bed erodibility underwent large seasonal variations, with mobile sediment present in the channel thalweg during winter that was absent in the spring and summer, when channel-bed erodibility was low and comparable to that of the tidal flats. Sediment on the northern (left) channel flank was mobile in summer and winter, whereas sediment on the southern flank was not. Seasonal changes in channel-bed erodibility are sufficient to produce order-of-magnitude changes in suspended sediment concentrations during peak tidal flows. Porosity just below the sediment surface was the best predictor of erodibility in our study area.
Jin, Hyun Mi; Jeong, Hye Im; Kim, Kyung Hyun; Hahn, Yoonsoo; Madsen, Eugene L; Jeon, Che Ok
2016-02-18
A genome-wide transcriptional analysis of Alteromonas naphthalenivorans SN2 was performed to investigate its ecophysiological behavior in contaminated tidal flats and seawater. The experimental design mimicked these habitats that either added naphthalene or pyruvate; tidal flat-naphthalene (TF-N), tidal flat-pyruvate (TF-P), seawater-naphthalene (SW-N), and seawater-pyruvate (SW-P). The transcriptional profiles clustered by habitat (TF-N/TF-P and SW-N/SW-P), rather than carbon source, suggesting that the former may exert a greater influence on genome-wide expression in strain SN2 than the latter. Metabolic mapping of cDNA reads from strain SN2 based on KEGG pathway showed that metabolic and regulatory genes associated with energy metabolism, translation, and cell motility were highly expressed in all four test conditions, probably highlighting the copiotrophic properties of strain SN2 as an opportunistic marine r-strategist. Differential gene expression analysis revealed that strain SN2 displayed specific cellular responses to environmental variables (tidal flat, seawater, naphthalene, and pyruvate) and exhibited certain ecological fitness traits -- its notable PAH degradation capability in seasonally cold tidal flat might be reflected in elevated expression of stress response and chaperone proteins, while fast growth in nitrogen-deficient and aerobic seawater probably correlated with high expression of glutamine synthetase, enzymes utilizing nitrite/nitrate, and those involved in the removal of reactive oxygen species.
Jin, Hyun Mi; Jeong, Hye Im; Kim, Kyung Hyun; Hahn, Yoonsoo; Madsen, Eugene L.; Jeon, Che Ok
2016-01-01
A genome-wide transcriptional analysis of Alteromonas naphthalenivorans SN2 was performed to investigate its ecophysiological behavior in contaminated tidal flats and seawater. The experimental design mimicked these habitats that either added naphthalene or pyruvate; tidal flat-naphthalene (TF-N), tidal flat-pyruvate (TF-P), seawater-naphthalene (SW-N), and seawater-pyruvate (SW-P). The transcriptional profiles clustered by habitat (TF-N/TF-P and SW-N/SW-P), rather than carbon source, suggesting that the former may exert a greater influence on genome-wide expression in strain SN2 than the latter. Metabolic mapping of cDNA reads from strain SN2 based on KEGG pathway showed that metabolic and regulatory genes associated with energy metabolism, translation, and cell motility were highly expressed in all four test conditions, probably highlighting the copiotrophic properties of strain SN2 as an opportunistic marine r-strategist. Differential gene expression analysis revealed that strain SN2 displayed specific cellular responses to environmental variables (tidal flat, seawater, naphthalene, and pyruvate) and exhibited certain ecological fitness traits –– its notable PAH degradation capability in seasonally cold tidal flat might be reflected in elevated expression of stress response and chaperone proteins, while fast growth in nitrogen-deficient and aerobic seawater probably correlated with high expression of glutamine synthetase, enzymes utilizing nitrite/nitrate, and those involved in the removal of reactive oxygen species. PMID:26887987
The manufacture of flat conductor cable
NASA Technical Reports Server (NTRS)
Angele, W.
1974-01-01
The major techniques are described for fabricating flat conductor cable (FCC). Various types of FCC, including unshielded, shielded, power, and signal, in both existing and conceptual constructions, are covered.
DOE Office of Scientific and Technical Information (OSTI.GOV)
John McCord
2007-09-01
This report documents transport data and data analyses for Yucca Flat/Climax Mine CAU 97. The purpose of the data compilation and related analyses is to provide the primary reference to support parameterization of the Yucca Flat/Climax Mine CAU transport model. Specific task objectives were as follows: • Identify and compile currently available transport parameter data and supporting information that may be relevant to the Yucca Flat/Climax Mine CAU. • Assess the level of quality of the data and associated documentation. • Analyze the data to derive expected values and estimates of the associated uncertainty and variability. The scope of thismore » document includes the compilation and assessment of data and information relevant to transport parameters for the Yucca Flat/Climax Mine CAU subsurface within the context of unclassified source-term contamination. Data types of interest include mineralogy, aqueous chemistry, matrix and effective porosity, dispersivity, matrix diffusion, matrix and fracture sorption, and colloid-facilitated transport parameters.« less
A novel flat-response x-ray detector in the photon energy range of 0.1-4 keV
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li Zhichao; Guo Liang; Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900
2010-07-15
A novel flat-response x-ray detector has been developed for the measurement of radiation flux from a hohlraum. In order to obtain a flat response in the photon energy range of 0.1-4 keV, it is found that both the cathode and the filter of the detector can be made of gold. A further improvement on the compound filter can then largely relax the requirement of the calibration x-ray beam. The calibration of the detector, which is carried out on Beijing Synchrotron Radiation Facility at Institute of High Energy Physics, shows that the detector has a desired flat response in the photonmore » energy range of 0.1-4 keV, with a response flatness smaller than 13%. The detector has been successfully applied in the hohlraum experiment on Shenguang-III prototype laser facility. The radiation temperatures inferred from the detector agree well with those from the diagnostic instrument Dante installed at the same azimuth angle from the hohlraum axis, demonstrating the feasibility of the detector.« less
A review of the geodynamic evolution of flat slab subduction in Mexico, Peru, and Chile
NASA Astrophysics Data System (ADS)
Constantin Manea, Vlad; Manea, Marina; Ferrari, Luca; Orozco, María Teresa; Wong Valenzuela, Raul; Husker, Allen Leroy; Kostoglodovc, Vlad; Ionescu, Constantin
2017-04-01
Subducting plates around the globe display a large variability in terms of slab geometry, including regions where smooth and little variation in subduction parameters is observed. While the vast majority of subduction slabs plunge into the mantle at different, but positive dip angles, the end-member case of flat-slab subduction seems to strongly defy this rule and move horizontally several hundreds of kilometers before diving into the surrounding hotter mantle. By employing a comparative assessment for the Mexican, Peruvian and Chilean flat-slab subduction zones we find a series of parameters that apparently facilitate slab flattening. Among them, trench roll-back, as well as strong variations and discontinuities in the structure of oceanic and overriding plates seem to be the most important. However, we were not able to find the necessary and sufficient conditions that provide an explanation for the formation of flat slabs in all three subduction zones. In order to unravel the origin of flat-slab subduction, it is probably necessary a numerical approach that considers also the influence of surrounding plates, and their corresponding geometries, on 3D subduction dynamics.
A review of the geodynamic evolution of flat slab subduction in Mexico, Peru, and Chile
NASA Astrophysics Data System (ADS)
Manea, V. C.; Manea, M.; Ferrari, L.; Orozco-Esquivel, T.; Valenzuela, R. W.; Husker, A.; Kostoglodov, V.
2017-01-01
Subducting plates around the globe display a large variability in terms of slab geometry, including regions where smooth and little variation in subduction parameters is observed. While the vast majority of subduction slabs plunge into the mantle at different, but positive dip angles, the end-member case of flat-slab subduction seems to strongly defy this rule and move horizontally several hundreds of kilometers before diving into the surrounding hotter mantle. By employing a comparative assessment for the Mexican, Peruvian and Chilean flat-slab subduction zones we find a series of parameters that apparently facilitate slab flattening. Among them, trench roll-back, as well as strong variations and discontinuities in the structure of oceanic and overriding plates seem to be the most important. However, we were not able to find the necessary and sufficient conditions that provide an explanation for the formation of flat slabs in all three subduction zones. In order to unravel the origin of flat-slab subduction, it is probably necessary a numerical approach that considers also the influence of surrounding plates, and their corresponding geometries, on 3D subduction dynamics.
Patterson, Jeffrey M.; Oppenheimer, Nicole E.; Feser, Erin H.
2015-01-01
Training the bench press exercise on a traditional flat bench does not induce a level of instability as seen in sport movements and activities of daily living. Twenty participants were recruited to test two forms of instability: using one dumbbell rather than two and lifting on the COR bench compared to a flat bench. Electromyography (EMG) amplitudes of the pectoralis major, middle trapezius, external oblique, and internal oblique were recorded and compared. Differences in range of motion (ROM) were evaluated by measuring an angular representation of the shoulder complex. Four separate conditions of unilateral bench press were tested while lifting on a: flat bench with one dumbbell, flat bench with two dumbbells, COR Bench with one dumbbell, and COR Bench with two dumbbells. The results imply that there are no differences in EMG amplitude or ROM between the COR bench and traditional bench. However, greater ROM was found to be utilized in the single dumbbell condition, both in the COR bench and the flat bench. PMID:26528421
Debonding Stress Concentrations in a Pressurized Lobed Sandwich-Walled Generic Cryogenic Tank
NASA Technical Reports Server (NTRS)
Ko, William L.
2004-01-01
A finite-element stress analysis has been conducted on a lobed composite sandwich tank subjected to internal pressure and cryogenic cooling. The lobed geometry consists of two obtuse circular walls joined together with a common flat wall. Under internal pressure and cryogenic cooling, this type of lobed tank wall will experience open-mode (a process in which the honeycomb is stretched in the depth direction) and shear stress concentrations at the junctures where curved wall changes into flat wall (known as a curve-flat juncture). Open-mode and shear stress concentrations occur in the honeycomb core at the curve-flat junctures and could cause debonding failure. The levels of contributions from internal pressure and temperature loading to the open-mode and shear debonding failure are compared. The lobed fuel tank with honeycomb sandwich walls has been found to be a structurally unsound geometry because of very low debonding failure strengths. The debonding failure problem could be eliminated if the honeycomb core at the curve-flat juncture is replaced with a solid core.
Superconducting transitions in flat-band systems
Iglovikov, V. I.; Hébert, F.; Grémaud, B.; ...
2014-09-11
The physics of strongly correlated quantum particles within a flat band was originally explored as a route to itinerant ferromagnetism and, indeed, a celebrated theorem by Lieb rigorously establishes that the ground state of the repulsive Hubbard model on a bipartite lattice with unequal number of sites in each sublattice must have nonzero spin S at half-filling. Recently, there has been interest in Lieb geometries due to the possibility of novel topological insulator, nematic, and Bose-Einstein condensed (BEC) phases. In this paper, we extend the understanding of the attractive Hubbard model on the Lieb lattice by using Determinant Quantum Montemore » Carlo to study real space charge and pair correlation functions not addressed by the Lieb theorems. Specifically, our results show unusual charge and charge transfer signatures within the flat band, and a reduction in pairing order at ρ = 2/3 and ρ = 4/3, the points at which the flat band is first occupied and then completely filled. Lastly, we compare our results to the case of flat bands in the Kagome lattice and demonstrate that the behavior observed in the two cases is rather different.« less
Design study of flat belt CVT for electric vehicles
NASA Technical Reports Server (NTRS)
Kumm, E. L.
1980-01-01
A continuously variable transmission (CVT) was studied, using a novel flat belt pulley arrangement which couples the high speed output shaft of an energy storage flywheel to the drive train of an electric vehicle. A specific CVT arrangement was recommended and its components were selected and sized, based on the design requirements of a 1700 KG vehicle. A design layout was prepared and engineering calculations made of component efficiencies and operating life. The transmission efficiency was calculated to be significantly over 90% with the expected vehicle operation. A design consistent with automotive practice for low future production costs was considered, together with maintainability. The technology advancements required to develop the flat belt CVT were identified and an estimate was made of how the size of the flat belt CVT scales to larger and smaller design output torques. The suitability of the flat belt CVT for alternate application to an electric vehicle powered by an electric motor without flywheel and to a hybrid electric vehicle powered by an electric motor with an internal combustion engine was studied.
Flat Tile Armour Cooled by Hypervapotron Tube: a Possible Technology for ITER
NASA Astrophysics Data System (ADS)
Schlosser, J.; Escourbiac, F.; Merola, M.; Schedler, B.; Bayetti, P.; Missirlian, M.; Mitteau, R.; Robin-Vastra, I.
Carbon fibre composite (CFC) flat tile armours for actively cooled plasma facing components (PFC’s) are an important challenge for controlled fusion machines. Flat tile concepts, water cooled by tubes, were studied, developed, tested and finally operated with success in Tore Supra. The components were designed for 10 MW/m2 and mock-ups were successfully fatigue tested at 15 MW/m2, 1000 cycles. For ITER, a tube-in-tile concept was developed and mock-ups sustained up to 25 MW/m2 for 1000 cycles without failure. Recently flat tile armoured mock-ups cooled by a hypervapotron tube successfully sustained a cascade failure test under a mean heat flux of 10 MW/m2 but with a doubling of the heat flux on some tiles to simulate missing tiles (500 cycles). This encouraging results lead to reconsider the limits for flat tile concept when cooled by hypervapotron (HV) tube. New tests are now scheduled to investigate these limits in regard to the ITER requirements. Experimental evidence of the concept could be gained in Tore Supra by installing a new limiter into the machine.
NASA Technical Reports Server (NTRS)
Borden, C. S.; Schwartz, D. L.
1984-01-01
The purpose of this study is to assess the relative economic potentials of concenrating and two-axis tracking flat-plate photovoltaic arrays for central-station applications in the mid-1990's. Specific objectives of this study are to provide information on concentrator photovoltaic collector probabilistic price and efficiency levels to illustrate critical areas of R&D for concentrator cells and collectors, and to compare concentrator and flat-plate PV price and efficiency alternatives for several locations, based on their implied costs of energy. To deal with the uncertainties surrounding research and development activities in general, a probabilistic assessment of commercially achievable concentrator photovoltaic collector efficiencies and prices (at the factory loading dock) is performed. The results of this projection of concentrator photovoltaic technology are then compared with a previous flat-plate module price analysis (performed early in 1983). To focus this analysis on specific collector alternatives and their implied energy costs for different locations, similar two-axis tracking designs are assumed for both concentrator and flat-plate options.
Computational Design of Flat-Band Material.
Hase, I; Yanagisawa, T; Kawashima, K
2018-02-26
Quantum mechanics states that hopping integral between local orbitals makes the energy band dispersive. However, in some special cases, there are bands with no dispersion due to quantum interference. These bands are called as flat band. Many models having flat band have been proposed, and many interesting physical properties are predicted. However, no real compound having flat band has been found yet despite the 25 years of vigorous researches. We have found that some pyrochlore oxides have quasi-flat band just below the Fermi level by first principles calculation. Moreover, their valence bands are well described by a tight-binding model of pyrochlore lattice with isotropic nearest neighbor hopping integral. This model belongs to a class of Mielke model, whose ground state is known to be ferromagnetic with appropriate carrier doping and on-site repulsive Coulomb interaction. We have also performed a spin-polarized band calculation for the hole-doped system from first principles and found that the ground state is ferromagnetic for some doping region. Interestingly, these compounds do not include magnetic element, such as transition metal and rare-earth elements.
Computational Design of Flat-Band Material
NASA Astrophysics Data System (ADS)
Hase, I.; Yanagisawa, T.; Kawashima, K.
2018-02-01
Quantum mechanics states that hopping integral between local orbitals makes the energy band dispersive. However, in some special cases, there are bands with no dispersion due to quantum interference. These bands are called as flat band. Many models having flat band have been proposed, and many interesting physical properties are predicted. However, no real compound having flat band has been found yet despite the 25 years of vigorous researches. We have found that some pyrochlore oxides have quasi-flat band just below the Fermi level by first principles calculation. Moreover, their valence bands are well described by a tight-binding model of pyrochlore lattice with isotropic nearest neighbor hopping integral. This model belongs to a class of Mielke model, whose ground state is known to be ferromagnetic with appropriate carrier doping and on-site repulsive Coulomb interaction. We have also performed a spin-polarized band calculation for the hole-doped system from first principles and found that the ground state is ferromagnetic for some doping region. Interestingly, these compounds do not include magnetic element, such as transition metal and rare-earth elements.
NASA Astrophysics Data System (ADS)
Muzafar Shah, Mazlina; Fatah Wahab, Abdul
2017-09-01
There are an abnormal electric activities or irregular interference in brain of epilepsy patient. Then a sensor will be put in patient’s scalp to measure and records all electric activities in brain. The result of the records known as Electroencephalography (EEG). The EEG has been transfer to flat EEG because it’s easier to analyze. In this study, the uncertainty in flat EEG data will be considered as fuzzy digital space. The purpose of this research is to show that the flat EEG is fuzzy topological digital space. Therefore, the main focus for this research is to introduce fuzzy topological digital space concepts with their properties such as neighbourhood, interior and closure by using fuzzy set digital concept and Chang’s fuzzy topology approach. The product fuzzy topology digital also will be shown. By introduce this concept, the data in flat EEG can considering having fuzzy topology digital properties and can identify the area in fuzzy digital space that has been affected by epilepsy seizure in epileptic patient’s brain.
Moving zone Marangoni drying of wet objects using naturally evaporated solvent vapor
Britten, Jerald A.
1997-01-01
A surface tension gradient driven flow (a Marangoni flow) is used to remove the thin film of water remaining on the surface of an object following rinsing. The process passively introduces by natural evaporation and diffusion of minute amounts of alcohol (or other suitable material) vapor in the immediate vicinity of a continuously refreshed meniscus of deionized water or another aqueous-based, nonsurfactant rinsing agent. Used in conjunction with cleaning, developing or wet etching application, rinsing coupled with Marangoni drying provides a single-step process for 1) cleaning, developing or etching, 2) rinsing, and 3) drying objects such as flat substrates or coatings on flat substrates without necessarily using heat, forced air flow, contact wiping, centrifugation or large amounts of flammable solvents. This process is useful in one-step cleaning and drying of large flat optical substrates, one-step developing/rinsing and drying or etching/rinsing/drying of large flat patterned substrates and flat panel displays during lithographic processing, and room-temperature rinsing/drying of other large parts, sheets or continuous rolls of material.
Moving zone Marangoni drying of wet objects using naturally evaporated solvent vapor
Britten, J.A.
1997-08-26
A surface tension gradient driven flow (a Marangoni flow) is used to remove the thin film of water remaining on the surface of an object following rinsing. The process passively introduces by natural evaporation and diffusion of minute amounts of alcohol (or other suitable material) vapor in the immediate vicinity of a continuously refreshed meniscus of deionized water or another aqueous-based, nonsurfactant rinsing agent. Used in conjunction with cleaning, developing or wet etching application, rinsing coupled with Marangoni drying provides a single-step process for (1) cleaning, developing or etching, (2) rinsing, and (3) drying objects such as flat substrates or coatings on flat substrates without necessarily using heat, forced air flow, contact wiping, centrifugation or large amounts of flammable solvents. This process is useful in one-step cleaning and drying of large flat optical substrates, one-step developing/rinsing and drying or etching/rinsing/drying of large flat patterned substrates and flat panel displays during lithographic processing, and room-temperature rinsing/drying of other large parts, sheets or continuous rolls of material. 5 figs.
Nonperturbative Renormalization Group Approach to Polymerized Membranes
NASA Astrophysics Data System (ADS)
Essafi, Karim; Kownacki, Jean-Philippe; Mouhanna, Dominique
2014-03-01
Membranes or membrane-like materials play an important role in many fields ranging from biology to physics. These systems form a very rich domain in statistical physics. The interplay between geometry and thermal fluctuations lead to exciting phases such flat, tubular and disordered flat phases. Roughly speaking, membranes can be divided into two group: fluid membranes in which the molecules are free to diffuse and thus no shear modulus. On the other hand, in polymerized membranes the connectivity is fixed which leads to elastic forces. This difference between fluid and polymerized membranes leads to a difference in their critical behaviour. For instance, fluid membranes are always crumpled, whereas polymerized membranes exhibit a phase transition between a crumpled phase and a flat phase. In this talk, I will focus only on polymerized phantom, i.e. non-self-avoiding, membranes. The critical behaviour of both isotropic and anisotropic polymerized membranes are studied using a nonperturbative renormalization group approach (NPRG). This allows for the investigation of the phase transitions and the low temperature flat phase in any internal dimension D and embedding d. Interestingly, graphene behaves just as a polymerized membrane in its flat phase.
A novel flat-response x-ray detector in the photon energy range of 0.1-4 keV.
Li, Zhichao; Jiang, Xiaohua; Liu, Shenye; Huang, Tianxuan; Zheng, Jian; Yang, Jiamin; Li, Sanwei; Guo, Liang; Zhao, Xuefeng; Du, Huabin; Song, Tianming; Yi, Rongqing; Liu, Yonggang; Jiang, Shaoen; Ding, Yongkun
2010-07-01
A novel flat-response x-ray detector has been developed for the measurement of radiation flux from a hohlraum. In order to obtain a flat response in the photon energy range of 0.1-4 keV, it is found that both the cathode and the filter of the detector can be made of gold. A further improvement on the compound filter can then largely relax the requirement of the calibration x-ray beam. The calibration of the detector, which is carried out on Beijing Synchrotron Radiation Facility at Institute of High Energy Physics, shows that the detector has a desired flat response in the photon energy range of 0.1-4 keV, with a response flatness smaller than 13%. The detector has been successfully applied in the hohlraum experiment on Shenguang-III prototype laser facility. The radiation temperatures inferred from the detector agree well with those from the diagnostic instrument Dante installed at the same azimuth angle from the hohlraum axis, demonstrating the feasibility of the detector.
Fault detection method for railway wheel flat using an adaptive multiscale morphological filter
NASA Astrophysics Data System (ADS)
Li, Yifan; Zuo, Ming J.; Lin, Jianhui; Liu, Jianxin
2017-02-01
This study explores the capacity of the morphology analysis for railway wheel flat fault detection. A dynamic model of vehicle systems with 56 degrees of freedom was set up along with a wheel flat model to calculate the dynamic responses of axle box. The vehicle axle box vibration signal is complicated because it not only contains the information of wheel defect, but also includes track condition information. Thus, how to extract the influential features of wheels from strong background noise effectively is a typical key issue for railway wheel fault detection. In this paper, an algorithm for adaptive multiscale morphological filtering (AMMF) was proposed, and its effect was evaluated by a simulated signal. And then this algorithm was employed to study the axle box vibration caused by wheel flats, as well as the influence of track irregularity and vehicle running speed on diagnosis results. Finally, the effectiveness of the proposed method was verified by bench testing. Research results demonstrate that the AMMF extracts the influential characteristic of axle box vibration signals effectively and can diagnose wheel flat faults in real time.
Open-loop correction for an eddy current dominated beam-switching magnet.
Koseki, K; Nakayama, H; Tawada, M
2014-04-01
A beam-switching magnet and the pulsed power supply it requires have been developed for the Japan Proton Accelerator Research Complex. To switch bunched proton beams, the dipole magnetic field must reach its maximum value within 40 ms. In addition, the field flatness should be less than 5 × 10(-4) to guide each bunched beam to the designed orbit. From a magnetic field measurement by using a long search coil, it was found that an eddy current in the thick endplates and laminated core disturbs the rise of the magnetic field. The eddy current also deteriorates the field flatness over the required flat-top period. The measured field flatness was 5 × 10(-3). By using a double-exponential equation to approximate the measured magnetic field, a compensation pattern for the eddy current was calculated. The integrated magnetic field was measured while using the newly developed open-loop compensation system. A field flatness of less than 5 × 10(-4), which is an acceptable value, was achieved.
Open-loop correction for an eddy current dominated beam-switching magnet
DOE Office of Scientific and Technical Information (OSTI.GOV)
Koseki, K., E-mail: kunio.koseki@kek.jp; Nakayama, H.; Tawada, M.
2014-04-15
A beam-switching magnet and the pulsed power supply it requires have been developed for the Japan Proton Accelerator Research Complex. To switch bunched proton beams, the dipole magnetic field must reach its maximum value within 40 ms. In addition, the field flatness should be less than 5 × 10{sup −4} to guide each bunched beam to the designed orbit. From a magnetic field measurement by using a long search coil, it was found that an eddy current in the thick endplates and laminated core disturbs the rise of the magnetic field. The eddy current also deteriorates the field flatness over the requiredmore » flat-top period. The measured field flatness was 5 × 10{sup −3}. By using a double-exponential equation to approximate the measured magnetic field, a compensation pattern for the eddy current was calculated. The integrated magnetic field was measured while using the newly developed open-loop compensation system. A field flatness of less than 5 × 10{sup −4}, which is an acceptable value, was achieved.« less
... from pinpoint to pinhead size. Shape. They are flat topped and round. Color. Bumps are usually the ... usually characterized by patches of red or purple, flat-topped, itchy bumps on the skin or lacy ...
Radius of curvature variations for annular, dark hollow and flat topped beams in turbulence
NASA Astrophysics Data System (ADS)
Eyyuboğlu, H. T.; Baykal, Y. K.; Ji, X. L.
2010-06-01
For propagation in turbulent atmosphere, the radius of curvature variations for annular, dark hollow and flat topped beams are examined under a single formulation. Our results show that for collimated beams, when examined against propagation length, the dark hollow, flat topped and annular Gaussian beams behave nearly the same as the Gaussian beam, but have larger radius of curvature values. Increased partial coherence and turbulence levels tend to lower the radius of curvature. Bigger source sizes on the other hand give rise to larger radius of curvature. Dark hollow and flat topped beams have reduced radius of curvature at longer wavelengths, whereas the annular Gaussian beam seems to be unaffected by wavelength changes; the radius of curvature of the Gaussian beam meanwhile rises with increasing wavelength.
[Early flat colorectal cancer].
Castelletto, R H; Chiarenza, C; Ottino, A; Garay, M L
1991-01-01
We report three cases of flat early colorectal carcinoma which were detected during the examination of 51 surgical specimens of colorectal resection. Two of them were endoscopically diagnosed, but the smallest one was not seen in the luminal instrumental examination. From the bibliographic analysis and our own experience we deduce the importance of flat lesions in the development of early colorectal carcinoma, either originated from pre-existent adenoma or de novo. Flat variants of adenoma, and presumably flush or depressed ones, must be considered as important factors in the early sequence adenoma-cancer. An appropriate endoscopic equipment with employment of additional staining techniques (such as carmine indigo and methylene blue) and the correct investigation during inflation-deflation procedures facilitates the identification of small lesions, their eradication and prevention from advanced forms of colorectal carcinoma.
Fragile surface zero-energy flat bands in three-dimensional chiral superconductors
NASA Astrophysics Data System (ADS)
Kobayashi, Shingo; Tanaka, Yukio; Sato, Masatoshi
2015-12-01
We study surface zero-energy flat bands in three-dimensional chiral superconductors with pz(px+i py) ν -wave pairing symmetry (ν is a nonzero integer), based on topological arguments and tunneling conductance. It is shown that the surface flat bands are fragile against (i) the surface misorientation and (ii) the surface Rashba spin-orbit interaction. The fragility of (i) is specific to chiral SCs, whereas that of (ii) happens for general odd-parity SCs. We demonstrate that these flat-band instabilities vanish or suppress a zero-bias conductance peak in a normal/insulator/superconductor junction, which behavior is clearly different from high-Tc cuprates and noncentrosymmetric superconductors. By calculating the angle-resolved conductance, we also discuss a topological surface state associated with the coexistence of line and point nodes.
Wetting of flat gradient surfaces.
Bormashenko, Edward
2018-04-01
Gradient, chemically modified, flat surfaces enable directed transport of droplets. Calculation of apparent contact angles inherent for gradient surfaces is challenging even for atomically flat ones. Wetting of gradient, flat solid surfaces is treated within the variational approach, under which the contact line is free to move along the substrate. Transversality conditions of the variational problem give rise to the generalized Young equation valid for gradient solid surfaces. The apparent (equilibrium) contact angle of a droplet, placed on a gradient surface depends on the radius of the contact line and the values of derivatives of interfacial tensions. The linear approximation of the problem is considered. It is demonstrated that the contact angle hysteresis is inevitable on gradient surfaces. Electrowetting of gradient surfaces is discussed. Copyright © 2018 Elsevier Inc. All rights reserved.
Evaluation of composite flattened tubular specimen. [fatigue tests
NASA Technical Reports Server (NTRS)
Liber, T.; Daniel, I. M.
1978-01-01
Flattened tubular specimens of graphite/epoxy, S-glass/epoxy, Kevlar-49/epoxy, and graphite/S-glass/epoxy hybrid materials were evaluated under static and cyclic uniaxial tensile loading and compared directly with flat coupon data of the same materials generated under corresponding loading conditions. Additional development for the refinement of the flattened specimen configuration and fabrication was required. Statically tested graphite/epoxy, S-glass/epoxy, and Kevlar 49/epoxy flattened tube specimens exhibit somewhat higher average strengths than their corresponding flat coupons. Flattened tube specimens of the graphite/S-glass/epoxy hybrid and the graphite/epoxy flattened tube specimens failed in parasitic modes with consequential lower strength than the corresponding flat coupons. Fatigue tested flattened tube specimens failed in parasitic modes resulting in lower fatigue strengths than the corresponding flat coupons.
Flat-fielding of Solar Hα Observations Based on the Maximum Correntropy Criterion
NASA Astrophysics Data System (ADS)
Xu, Gao-Gui; Zheng, Sheng; Lin, Gang-Hua; Wang, Xiao-Fan
2016-08-01
The flat-field CCD calibration method of Kuhn et al. (KLL) is an efficient method for flat-fielding. However, since it depends on the minimum of the sum of squares error (SSE), its solution is sensitive to noise, especially non-Gaussian noise. In this paper, a new algorithm is proposed to determine the flat field. The idea is to change the criterion of gain estimate from SSE to the maximum correntropy. The result of a test on simulated data demonstrates that our method has a higher accuracy and a faster convergence than KLL’s and Chae’s. It has been found that the method effectively suppresses noise, especially in the case of typical non-Gaussian noise. And the computing time of our algorithm is the shortest.
NASA Astrophysics Data System (ADS)
Hafid Bouougri, El; Porada, Hubertus
2010-05-01
In terms of optimal light utilization, mat surfaces ideally are flat. In nature, however, flat mat surfaces are observed rarely or in restricted patches only. Rather they are shaped by a variety of linear and subcircular to irregular protrusions at various scales, including overgrown upturned crack margins, bulges (‘petees'), domes (‘blisters' and ‘pustules'), reticulate networks with tufts and pinnacles etc. These features are so characteristic that ‘mat types' have been established according to their prevalence, e.g., film, flat, smooth, crinkle, blister, tufted, cinder, mammilate, pustular and polygonal mats (Kendall and Skipwith, 1969; Logan et al., 1974). Responsible for the development of such mat surface features are environmental (physical and chemical) factors and, in reaction, the opportunistic growth behaviour of the participating bacterial taxa. Theoretically, a ‘juvenile' mat may be assumed as being flat, evolving into various forms with typical surface morphologies according to environmental impacts and respective bacterial reactions. Observations in the Abu Dhabi evaporitic carbonate tidal flats and Tunisian evaporitic siliciclastic tidal flats demonstrate that topography plays a fundamental role, both on the large scale of the tidal flat and on the small scale of mat surface morphology. It controls, together with related factors like, e.g., frequency of tidal flooding; duration of water cover; frequency and duration of subaerial exposure, the spatial distribution and the temporal evolution of mat surface structures. On the tidal flat scale, topographic differences result a priori from its seaward gradient and may arise additionally from physical processes which may modify the substrate surface and produce in the intertidal and lower supratidal zones narrow creeks and shallow depressions meandering perpendicular to the slope. Within a wide tidal flat without local topographic changes in the tidal zones, mat surface structures display a typical shore-parallel zonality. In contrast, in tidal flats with slight changes in topography, the typical shore-parallel zonality appears disturbed mainly along the intertidal and lower supratidal zones. The mat surface structures within each tidal zone show local and lateral transitions but all evolve from an incipient flat or polygonal mat. On the mat scale, microtopographic differences are created by the mats themselves, e.g., in the form of upturned crack margins, bulges and domes. All these are small-scale topographic highs that influence the distribution of microbial activity and mat growth dynamics. In the Abu Dhabi area it is observed that smooth or polygonal mats may grade temporally into mammilate, cinder or pustular and tufted mats along an evolutionary path controlled by preferred growth along bulges and upturned crack margins. A similar temporal evolution appears in the intertidal and supratidal zones in Tunisia where local changes on mat-surface induce a variety of mat-growth struc¬tures on and along upturned crack margins, gas domes and isolated to polygonal bulges and petee ridges. References Kendall C.G.St.C, Skipwith, P.A.d'E. (1968) Recent algal mats of a Persian gulf lagoon. J. Sedim. Res., 38, 1040-1058. Logan B.W. Hoffman P. Gebelein, C.D. (1974) Algal mats, cryptalgal fabrics, and structures, Hamelin Pool, Western Australia. AAPG Mem., 22, 140-194.
Properties of Special Types of Radiators
NASA Technical Reports Server (NTRS)
Parsons, S R
1921-01-01
This report discusses the general performance characteristics of three special classes of radiators: those with flat plate water tubes, fin and tube types, and types that whistle in an air stream. Curves and tables show the performance of representative radiators of each class and compare the flat plate and whistling types. Empirical equations are given for estimating the performance of flat plate radiators of various dimensions. This report also contains a brief discussion, with curves, showing the effect of yawing on the properties of a radiator.
20. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING NORTHEAST. ...
20. AERIAL VIEW OF THE ROCKY FLATS PLANT LOOKING NORTHEAST. THE PLANT WAS COMPOSED OF FOUR WIDELY SEPARATED AREAS, EACH ONE PERFORMING A DIFFERENT TYPE OF WORK. PLANT A (44), SOUTHWEST, FABRICATED PARTS FROM DEPLETED URANIUM, PLANT B (81), SOUTH, WAS ENRICHED URANIUM OPERATIONS, PLANT C (71), NORTH, PLUTONIUM OPERATIONS, AND PLANT D (91), EAST, WAS FINAL ASSEMBLY, SHIPPING AND RECEIVING (2/6/66). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO
Polymeric and Lipid Membranes—From Spheres to Flat Membranes and vice versa
Saveleva, Mariia S.; Gorin, Dmitry A.; Skirtach, Andre G.
2017-01-01
Membranes are important components in a number of systems, where separation and control of the flow of molecules is desirable. Controllable membranes represent an even more coveted and desirable entity and their development is considered to be the next step of development. Typically, membranes are considered on flat surfaces, but spherical capsules possess a perfect “infinite” or fully suspended membranes. Similarities and transitions between spherical and flat membranes are discussed, while applications of membranes are also emphasized. PMID:28809796
Flat connections and nonlocal conserved quantities in irrational conformal field theory
DOE Office of Scientific and Technical Information (OSTI.GOV)
Halpern, M.B.; Obers, N.A.
1995-03-01
Irrational conformal field theory (ICFT) includes rational conformal field theory as a small subspace, and the affine-Virasoro Ward identities describe the biconformal correlators of ICFT. The Ward identities are reformulated as an equivalent linear partial differential system with flat connections and new nonlocal conserved quantities. As examples of the formulation, the system of flat connections is solved for the coset correlators, the correlators of the affine-Sugawara nests, and the high-level [ital n]-point correlators of ICFT.
Development study of the X-ray scattering properties of a group of optically polished flat samples
NASA Technical Reports Server (NTRS)
Froechtenigt, J. F.
1973-01-01
A group of twelve optically polished flat samples were used to study the scattering of X-rays. The X-ray beam reflected from the twelve optical flat samples was analyzed by means of a long vacuum system of special design for these tests. The scattering measurements were made at 8.34A and 0.92 deg angle of incidence. The results for ten of the samples are comparable, the two exceptions being the fire polished samples.
1986-08-01
AD-A174 952 FINITE - DIFFERENCE SOLUTIONS FOR CONPRESSIBLE LANINAR 1/2 BOUNDARY-LAYER FLOUS (U) TORONTO UNIV DOWNSVIEW (ONTARIO) INST FOR AEROSPACE...dilute dusty gas over a semi-infinite flat plate. Details are given of the impliit finite , difference schemes as well as the boundary conditions... FINITE - DIFFERENCE SOLUTIONS FOR COMPRESSIBLE LAMINAR BOUNDARY-LAYER FLOWS OF A DUSTY GAS OVER A SEMI-INFINITE FLAT PLATE by B. Y. Wang and I. I
NASA Astrophysics Data System (ADS)
Huff, Howard R.; Vigil, Joseph C.; Kuyel, Birol; Chan, David Y.; Nguyen, Long P.
1992-06-01
An experimental study was conducted to correlate wafer site flatness SFQD with stepper performance for half-micron lines and spaces. CD measurements were taken on wafers patterned on both GCA pre-production XLS i-line and SVGL Micrascan-90 DUV steppers as well as focus measurements on the Micrascan-90. Wafer site flatness SFQD less than 0.3 micrometers was observed to be a sufficiently small variable in CD non-uniformities for these initial half-micron stepper applications.
Great Salt Lake and Bonneville Salt Flats, UT, USA
NASA Technical Reports Server (NTRS)
1992-01-01
This is a view of the Great Salt Lake and nearby Bonneville Salt Flats, UT, (41.0N, 112.5W). A railroad causeway divides the lake with a stark straight line changing the water level and chemistry of the lake as a result. Fresh water runoff enters from the south adding to the depth and reducing the salinity. The north half receives little frsh water and is more saline and shallow. The Bonnieville Salt Flats is the lakebed of a onetime larger lake.
NASA Technical Reports Server (NTRS)
Schwarz, Mark A.; Kent, Craig J.; Bousquet, Robert; Brown, Steven W.
2015-01-01
This work describes the development of an improved vacuum compatible flat plate radiometric source used for characterizing and calibrating remote optical sensors, in situ, throughout their testing period. The original flat plate radiometric source was developed for use by the VIIRS instrument during the NPOESS Preparatory Project (NPP). Following this effort, the FPI has had significant upgrades in order to improve both the radiometric throughput and uniformity. Results of the VIIRS testing with the reconfigured FPI are reported and discussed.
Great Salt Lake and Bonneville Salt Flats, UT, USA
1992-04-02
This is a view of the Great Salt Lake and nearby Bonneville Salt Flats, UT, (41.0N, 112.5W). A railroad causeway divides the lake with a stark straight line changing the water level and chemistry of the lake as a result. Fresh water runoff enters from the south adding to the depth and reducing the salinity. The north half receives little frsh water and is more saline and shallow. The Bonnieville Salt Flats is the lakebed of a onetime larger lake.
Polymeric and Lipid Membranes-From Spheres to Flat Membranes and vice versa.
Saveleva, Mariia S; Lengert, Ekaterina V; Gorin, Dmitry A; Parakhonskiy, Bogdan V; Skirtach, Andre G
2017-08-15
Membranes are important components in a number of systems, where separation and control of the flow of molecules is desirable. Controllable membranes represent an even more coveted and desirable entity and their development is considered to be the next step of development. Typically, membranes are considered on flat surfaces, but spherical capsules possess a perfect "infinite" or fully suspended membranes. Similarities and transitions between spherical and flat membranes are discussed, while applications of membranes are also emphasized.
2013-09-30
Contrasting Mesotidal Flats Sediment Flux through the Mekong Tidal River, Delta and Mangrove Shoreline Instrumentation to Support Investigation of Large...scales), and thereby validate localized measurements and numerical models of sediment transport for diverse tidal systems (tidal flats , mangrove forests...deltaic distributaries). OBJECTIVES The specific objectives are to: a) document changes in bed elevation (deposition, erosion) on time
NASA Astrophysics Data System (ADS)
Bagchi, Arjun; Grumiller, Daniel
2013-07-01
The holographic principle has a concrete realization in the Anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence. If this principle is a true fact about quantum gravity then it must also hold beyond AdS/CFT. In this paper, we address specifically holographic field theory duals of gravitational theories in asymptotically flat spacetimes. We present some evidence of our recent conjecture that three-dimensional (3d) conformal Chern-Simons gravity (CSG) with flat space boundary conditions is dual to an extremal CFT.
G-structures and domain walls in heterotic theories
NASA Astrophysics Data System (ADS)
Lukas, Andre; Matti, Cyril
2011-01-01
We consider heterotic string solutions based on a warped product of a four-dimensional domain wall and a six-dimensional internal manifold, preserving two supercharges. The constraints on the internal manifolds with SU(3) structure are derived. They are found to be generalized half-flat manifolds with a particular pattern of torsion classes and they include half-flat manifolds and Strominger's complex non-Kahler manifolds as special cases. We also verify that previous heterotic compactifications on half-flat mirror manifolds are based on this class of solutions.
Lift Production on Flapping and Rotary Wings at Low Reynolds Numbers
2016-02-26
though parameter variations were also performed. For the rotating cases, the wing was an aspect ratio 2 rectangular flat plate , and the root cutout (i.e...rectangular flat plate . 2 U (Side View) (a) 1A: Rectilinear pitch U (Side View) (b) 1B: Rectilinear surge (Top View) (Side View) (c) 2A: Rotational...0.5c φ (b) A=2 flat plate wing Figure 2: Schematic of the AVT-202 rotating wing kinematics and geometry, from Ref. 12. 3.2 Experimental Setup Rotating
Kory Westlund, Jacqueline M; Jeong, Sooyeon; Park, Hae W; Ronfard, Samuel; Adhikari, Aradhana; Harris, Paul L; DeSteno, David; Breazeal, Cynthia L
2017-01-01
Prior research with preschool children has established that dialogic or active book reading is an effective method for expanding young children's vocabulary. In this exploratory study, we asked whether similar benefits are observed when a robot engages in dialogic reading with preschoolers. Given the established effectiveness of active reading, we also asked whether this effectiveness was critically dependent on the expressive characteristics of the robot. For approximately half the children, the robot's active reading was expressive; the robot's voice included a wide range of intonation and emotion ( Expressive ). For the remaining children, the robot read and conversed with a flat voice, which sounded similar to a classic text-to-speech engine and had little dynamic range ( Flat ). The robot's movements were kept constant across conditions. We performed a verification study using Amazon Mechanical Turk (AMT) to confirm that the Expressive robot was viewed as significantly more expressive, more emotional, and less passive than the Flat robot. We invited 45 preschoolers with an average age of 5 years who were either English Language Learners (ELL), bilingual, or native English speakers to engage in the reading task with the robot. The robot narrated a story from a picture book, using active reading techniques and including a set of target vocabulary words in the narration. Children were post-tested on the vocabulary words and were also asked to retell the story to a puppet. A subset of 34 children performed a second story retelling 4-6 weeks later. Children reported liking and learning from the robot a similar amount in the Expressive and Flat conditions. However, as compared to children in the Flat condition, children in the Expressive condition were more concentrated and engaged as indexed by their facial expressions; they emulated the robot's story more in their story retells; and they told longer stories during their delayed retelling. Furthermore, children who responded to the robot's active reading questions were more likely to correctly identify the target vocabulary words in the Expressive condition than in the Flat condition. Taken together, these results suggest that children may benefit more from the expressive robot than from the flat robot.
NASA Astrophysics Data System (ADS)
Young, S. M.; Ishiga, H.
2012-12-01
The chemical compositions of sediments from Yatsushiro tidal flat, Kuma River, and Arase dam (south west Kyushu, Japan) have been determined to examine changes between 2002 and 2012. In 2002 sediment supply to the bay from the Kuma River was restricted by the Arase dam; however in 2010 the dam was opened, allowing resumption of natural sediment transport. Abundances of 24 elements in Yatsushiro tidal flat sediments (n=22), suspended solids in the bay (n=6), Kuma River stream sediments (n=5) and suspended solids (n=2) were determined by XRF. Ripple marks in the Yatsushiro tidal flat indicate inflow of coarser material from the reinvigorated river. Bulk chemical composition of the tidal flat sediments has changed since 2002, with marked decreases in As, Zn and total sulfur, and lesser and more variable decrease in Pb. Mn values are higher in the northern tidal flats, suggesting anoxic conditions in the sediments at those sites. Suspended solids in both the Kuma River and Yatsushiro Bay have very low values of heavy metals, indicating low absorption and dilution by high organic matter contents. Sediments behind the Arase dam in 2002 had high abundances of most of the elements analyzed. However, abundances in Kuma River stream sediments at similar locations have fallen since the dam was opened in 2010. Kuma River sediments are characteristically coarser than those in Yatsushiro Bay, except at three locations. The river sediments are relatively uniform in composition, with ranges of 72.27-75.35 wt% SiO2 and 12.09-14.01 wt% Al2O3, compared to 55.40-77.89 and 11.61-21.44 respectively for Yatsushiro Bay tidal flat sediments. Average values in both suites are similar to UCC. Decreased heavy metal contents in the bay sediments after opening of the dam is attributed to dilution by previously impounded quartz and feldspar. Restoration of natural sediment transport has thus bought about a favorable environmental change. Key words: Yatsushiro bay, Kuma River, Geochemistry, Tidal flat, Environmental change.
Baby's Head Shape: What's Normal?
... out. This is known as positional plagiocephaly. Positional molding might be most noticeable when you're looking ... the flat side might look pushed forward. Positional molding is generally considered a cosmetic issue. Flat spots ...
Method of manufacturing lightweight thermo-barrier material
NASA Technical Reports Server (NTRS)
Blair, Winford (Inventor)
1987-01-01
A method of manufacturing thermal barrier structures comprising at least three dimpled cores separated by flat plate material with the outer surface of the flat plate material joined together by diffusion bonding.
NASA Astrophysics Data System (ADS)
Andreucci, Stefano; Pistis, Marco; Funedda, Antonio; Loi, Alfredo
2017-11-01
The Chattian-Aquitanian carbonate system of Isili sub-basin (SE Sardinia, Italy) were studied to better understand the hydrodynamic processes controlling the formation of landward-downlapping, rhodolith-rich, giant clinoforms. The studied flat-topped platform was attached to an island (semi-isolated) and migrated onshore (landward) over a shallow marine, protected embayment. The depositional profile is characterized by four, sea to land, zones: seaward slope, flat-topped platform (submerged flat), landward slope and mixed siliciclastic-carbonate embayment. In particular, these zones record different levels, from high to moderate, of hydrodynamic energy and persistency. The paleodepth of the studied succession, based on T/D test on Amphistegina specimens, red-algal genera and geometric reconstruction of the overall system, ranges from - 10 to - 30 m for the platform up to around - 40 m for the landward slope base. Thus, the flat-topped platform was permanently submerged and an extensive carbonate (sea grass, algal and bryozoan-algal) factory along with oyster framestones developed. The widespread presence in the barren zones of rhodolith-to-shell rich small to very small compound dunes (high-energy zone) suggests that the flat-topped platform was periodically swept by unidirectional, landward-directed currents. These currents allow the formation of large-scale, rhodolith-rich clinobeds along the landward slope (washover fan-like system). The presence of rodolith pavements developed along the flat-topped platform at or slightly below the fairweather wave base suggests that clinobeds were formed in a nearshore, shallow subtidal setting. Finally, the shallow marine, protected embayment (moderate-energy zone) represents the widening distal reaches of the currents flowing or along the clinoforms or from the coast basinward (river floods and/or ebb tidal currents). Despite few tidal-related sedimentary structures such as bi-directional ripples and small compound dunes separated by finer-grained ;drapes; or reactivation surfaces were observed, the prevailing processes acting over the platform are unidirectional, landward-directed currents possibly associated with longshore currents and/or wave actions. However, the resultant migration of the whole system onshore (landward) cannot be easily explained with storm or wind-related processes. Thus the studied flat-topped platform seems to be controlled by long term tidal regulation within a meso to macro tidal regime. In particular, such meso/macro tidal environments experience multiannual to multidecennial phases of stronger/weaker tidal range fluctuations resembling periods of relatively sea highs and lows with respect to the mean sea level (0 m). All the (wind, storm, wave and tidal) currents sweeping the flat-topped platform were maxima during phases of strong tidal fluctuations generating erosion and sediment transportation over the flat and accumulation on the landward slope (clinobeds). Conversely, during phases of weaker tidal range fluctuations overall currents were minima, clinoforms did not develop and factories widespread re-colonized the submerged flat. Therefore, the studied platform developed in a current-dominated and tidal modulated setting. Finally, the studied carbonates of Sardinia suggest that the Sardinian seaway and the incipient Provençal basin during the Chattian-Aquitanian were, locally, capable to generate meso to macro tidal conditions.
Crack growth measured on flat and curved surfaces at cryogenic temperatures
NASA Technical Reports Server (NTRS)
Orange, T. W.; Sullivan, T. L.
1967-01-01
Multiple element continuity gage measures plane stress crack growth plus surface crack growth under plane strain conditions. The gage measures flat and curved surfaces and operates at cryogenic temperatures.
Flat Terahertz Reflective Focusing Metasurface with Scanning Ability.
Yi, Huan; Qu, Shi-Wei; Chen, Bao-Jie; Bai, Xue; Ng, Kung Bo; Chan, Chi Hou
2017-06-14
The ability to manipulate the propagation properties of electromagnetic waves, e.g., divergence, focusing, holography or deflection, is very significant in terahertz applications. Metasurfaces with flat structures are attractive for achieving such manipulations in terahertz band, as they feature low profile, lightweight, and ease of design and installation. Several types of terahertz reflective or transmitting metasurfaces with focusing function have been implemented recently, but none of them can provide scanning ability with controllable focus. Here, a flat reflective metasurface featuring controllable focal shift is proposed and experimentally demonstrated. Furthermore, the principle of designing a focus scanning reflective metasurface is presented and the focusing characteristics are discussed, including focus scanning along a line parallel or orthogonal to the metasurface with a large bandwidth. These interesting properties indicate that this flat reflective metasurface could play a key role in many terahertz imaging and detection systems.
13. AERIAL VIEW OF THE ROCKY FLATS PLANT FROM DIRECTLY ...
13. AERIAL VIEW OF THE ROCKY FLATS PLANT FROM DIRECTLY OVERHEAD IN 1954. IN 1950, DOW CHEMICAL COMPANY WAS CHOSEN BY THE ATOMIC ENERGY COMMISSION TO ESTABLISH THE ROCKY FLATS PLANT AS AN ATOMIC BOMB TRIGGER FABRICATION FACILITY. THE CRITERIA FOR SITING SUCH A PLANT INCLUDED A LOCATION WEST OF THE MISSISSIPPI, NORTH OF TEXAS, SOUTH OF THE NORTHERN BORDER OF COLORADO, AND EAST OF UTAH; A DRY MODERATE CLIMATE; A SUPPORTING POPULATION OF AT LEAST 25,000 PEOPLE; AND ACCESSIBILITY FROM LOS ALAMOS, NM, CHICAGO, IL, AND ST. LOUIS, MO. TWENTY-ONE AREAS IN THE UNITED STATES WERE SUGGESTED; SEVEN LOCATIONS WERE SCREENED IN THE DENVER AREA. THIS FOUR-SQUARE MILE AREA WAS SELECTED AND CONSTRUCTION BEGAN IN 1951 (8/31/54). - Rocky Flats Plant, Bounded by Indiana Street & Routes 93, 128 & 72, Golden, Jefferson County, CO
NASA Technical Reports Server (NTRS)
1983-01-01
The Flat Plate Solar Array Project, focuses on advancing technologies relevant to the design and construction of megawatt level central station systems. Photovoltaic modules and arrays for flat plate central station or other large scale electric power production facilities require the establishment of a technical base that resolves design issues and results in practical and cost effective configurations. Design, qualification and maintenance issues related to central station arrays derived from the engineering and operating experiences of early applications and parallel laboratory reserch activities are investigated. Technical issues are examined from the viewpoint of the utility engineer, architect/engineer and laboratory researcher. Topics on optimum source circuit designs, module insulation design for high system voltages, array safety, structural interface design, measurements, and array operation and maintenance are discussed.
Visible light focusing flat lenses based on hybrid dielectric-metal metasurface reflector-arrays
Fan, Qingbin; Huo, Pengcheng; Wang, Daopeng; Liang, Yuzhang; Yan, Feng; Xu, Ting
2017-01-01
Conventional metasurface reflector-arrays based on metallic resonant nanoantenna to control the wavefront of light for focusing always suffer from strong ohmic loss at optical frequencies. Here, we overcome this challenge by constructing a non-resonant, hybrid dielectric-metal configuration consisting of TiO2 nanofins associated with an Ag reflector substrate that provides a broadband response and high polarization conversion efficiency in the visible range. A reflective flat lens based on this configuration shows an excellent focusing performance with the spot size close to the diffraction limit. Furthermore, by employing the superimposed phase distribution design to manipulate the wavefront of the reflected light, various functionalities, such as multifocal and achromatic focusing, are demonstrated for the flat lenses. Such a reflective flat lens will find various applications in visible light imaging and sensing systems. PMID:28332611
Hodges, Kurt B; Lopez-Beltran, Antonio; Davidson, Darrell D; Montironi, Rodolfo; Cheng, Liang
2010-02-01
The 2004 World Health Organization classification system for urothelial neoplasia classifies flat-related preneoplastic lesions as urothelial hyperplasia (flat and papillary), reactive urothelial atypia, urothelial atypia of unknown significance, urothelial dysplasia (low-grade intraurothelial neoplasia), and urothelial carcinoma in situ (high-grade intraurothelial neoplasia). Each lesion is defined with precise nomenclature and strict morphologic criteria. In many cases, morphologic features alone suffice for diagnosis. Other cases may require a panel of immunohistochemical antibodies consisting of cytokeratin 20, p53, and CD44 for diagnosis. Recent molecular studies have provided further insight into the premalignant potential of these urothelial lesions. Herein, we present a review of flat urothelial lesions of the urinary bladder as defined by the 2004 World Health Organization classification with focus on the clinicopathologic, immunohistochemical, and molecular features. Copyright 2010 Elsevier Inc. All rights reserved.
IDENTIFICATION BADGE WITH DETACHABLE CLIP
Burns, M.T.
1962-09-18
The clip has a long slot with a round enlarged end, flat on one side. The badge has a headed member that is circular except for a flat side. The badge is connected to, or disconnected from, the clip by insertion of the headed member through the enlarged end of the slot in the clip. The badge is unlikely to be accidentally disconnected from the clip while being worn on a worker's clothing, because the weight of the badge keeps the headed member away from the enlarged end of the slot in the clip, and the headed member can pass through the enlarged end of the slot only at one relative angular position between badge and clip, namely, that angle at which the flat side of the headed member is coincident with the flat side of the enlarged end of the slot. (AEC)
Projective flatness in the quantisation of bosons and fermions
NASA Astrophysics Data System (ADS)
Wu, Siye
2015-07-01
We compare the quantisation of linear systems of bosons and fermions. We recall the appearance of projectively flat connection and results on parallel transport in the quantisation of bosons. We then discuss pre-quantisation and quantisation of fermions using the calculus of fermionic variables. We define a natural connection on the bundle of Hilbert spaces and show that it is projectively flat. This identifies, up to a phase, equivalent spinor representations constructed by various polarisations. We introduce the concept of metaplectic correction for fermions and show that the bundle of corrected Hilbert spaces is naturally flat. We then show that the parallel transport in the bundle of Hilbert spaces along a geodesic is a rescaled projection provided that the geodesic lies within the complement of a cut locus. Finally, we study the bundle of Hilbert spaces when there is a symmetry.
NASA Technical Reports Server (NTRS)
Schwarz, Mark A.; Kent, Craig J.; Bousquet, Robert; Brown, Steven W.
2016-01-01
In this work, we describe an improved thermal-vacuum compatible flat plate radiometric source which has been developed and utilized for the characterization and calibration of remote optical sensors. This source is unique in that it can be used in situ, in both ambient and thermal-vacuum environments, allowing it to follow the sensor throughout its testing cycle. The performance of the original flat plate radiometric source was presented at the 2009 SPIE1. Following the original efforts, design upgrades were incorporated into the source to improve both radiometric throughput and uniformity. The pre-thermal-vacuum (pre-TVAC) testing results of a spacecraft-level optical sensor with the improved flat plate illumination source, both in ambient and vacuum environments, are presented. We also briefly discuss potential FPI configuration changes in order to improve its radiometric performance.
Productivity and abundance of large sponge populations on Flinders Reef flats, Coral Sea
NASA Astrophysics Data System (ADS)
Wilkinson, Clive R.
1987-04-01
Large populations of flattened sponges with cyanobacterial symbionts were observed on the shallow reef-flats of the Flinders Reefs, Coral Sea. Estimates of these populations indicated as many as 60 individuals with a total wet biomass of 1.2 kg per m2 in some areas. Along a metre wide transect across 1.3 km of reef flat the population was estimated at 530 kg wet weight sponge (mean 411 g m-2). The four prominent species had instantaneous P/R ratios between 1.3 and 1.8 at optimum light such that photosynthetic productivity was calculated to provide between 61 and 80% of sponge energy requirements in summer and 48 to 64% in winter. While such sponge beds are a prominent feature of these reefs, they appear to contribute less than 10% of gross reef-flat productivity.
Printed Antenna Array with Flat-Top Radiation Pattern
NASA Astrophysics Data System (ADS)
Milijić, Marija R.; Nešić, Aleksandar D.; Milovanović, Bratislav D.; Nešić, Dušan A.
2018-04-01
A printed antenna array consisting of 10 wideband symmetrical pentagonal dipoles is presented. The feed network of impedance transformers is employed to provide appropriate amplitude and phase distribution necessary to obtain flat top beam pattern. The measured results demonstrate excellent radiation characteristics including 38° flat gain region with maximum ripple of 3.5 dB at the centre frequency. Furthermore, the proposed antenna that is placed in corner reflector with angle of 60° has good gain (17 dBi) and side lobe suppression (18.9 dB). Although it is designed at the centre frequency fc=12 GHz, it was shown to be capable of shaping a good flat top radiation pattern within a fractional bandwidth at least 6 % of centre frequency. Also, proposed antenna features cheap, simple and easy fabrication that makes it suitable for mass production.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mahtab, M., E-mail: m.mahtab.83@gmail.com; Habibi, M., E-mail: mortezahabibi@aut.ac.ir
2013-12-15
The effect of different anode tip geometries on the intensity of soft and hard X-rays emitted from a 4-kJ plasma focus device is investigated using five different anode tips. The shapes of the uppermost region of these anodes (tips) have been cylindrical-flat, cylindrical-hollow, spherical-convex, cone-flat, and cone-hollow. For time-resolved measurement of the emitted X-rays, several BPX-65 pin diodes covered by different filters and a fast plastic scintillator are used. Experimental results have shown that, the highest intensity of the both soft and hard X-ray is recorded in cone-flat, spherical-convex, and cone-hollow tips, respectively. The use of cone-flat anode tip hasmore » augmented the emitted X-ray three times.« less
NASA Astrophysics Data System (ADS)
Kim, Hoon-Young; Choi, Won-Suk; Ji, Suk-Young; Shin, Young-Gwan; Jeon, Jin-Woo; Ahn, Sanghoon; Cho, Sung-Hak
2018-02-01
This study compares the ablation morphologies obtained with a femtosecond laser of both Gaussian and quasi-flat top beam profiles when applied to indium tin oxide (ITO) thin films for the purpose of OLED repair. A femtosecond laser system with a wavelength of 1030 nm and pulse duration of 190 fs is used to pattern an ITO thin film. The laser fluence is optimized for patterning at 1.38 J/cm2. The patterned ITO thin film is then evaluated through both optical microscope and atomic force microscope. Ablations with a square quasi-flat top beam are demonstrated using slits with varying x- y axes. With the Gaussian beam, the pattern width of the ablated area is shown to range from 9.17 to 9.99 μm when the number of irradiation pulse increases from one to six. In contrast, when slit control is used to obtain a quasi-flat top beam, the ablated pattern width remains constant at 10 μm, despite the increase in the number of pulse. The improved surface roughness is correlated with the quasi-flat top beam through measured Ra values. Furthermore, when using the Gaussian beam, the minimum resolution of the controllable ablation depth on the ITO thin film is found to be 60 nm. In contrast, when the quasi-flat top beam is used, the minimum ablation depth decreases to 40 nm.
Critical width of tidal flats triggers marsh collapse in the absence of sea-level rise
Mariotti, Giulio; Fagherazzi, Sergio
2013-01-01
High rates of wave-induced erosion along salt marsh boundaries challenge the idea that marsh survival is dictated by the competition between vertical sediment accretion and relative sea-level rise. Because waves pounding marshes are often locally generated in enclosed basins, the depth and width of surrounding tidal flats have a pivoting control on marsh erosion. Here, we show the existence of a threshold width for tidal flats bordering salt marshes. Once this threshold is exceeded, irreversible marsh erosion takes place even in the absence of sea-level rise. This catastrophic collapse occurs because of the positive feedbacks among tidal flat widening by wave-induced marsh erosion, tidal flat deepening driven by wave bed shear stress, and local wind wave generation. The threshold width is determined by analyzing the 50-y evolution of 54 marsh basins along the US Atlantic Coast. The presence of a critical basin width is predicted by a dynamic model that accounts for both horizontal marsh migration and vertical adjustment of marshes and tidal flats. Variability in sediment supply, rather than in relative sea-level rise or wind regime, explains the different critical width, and hence erosion vulnerability, found at different sites. We conclude that sediment starvation of coastlines produced by river dredging and damming is a major anthropogenic driver of marsh loss at the study sites and generates effects at least comparable to the accelerating sea-level rise due to global warming. PMID:23513219
Critical width of tidal flats triggers marsh collapse in the absence of sea-level rise.
Mariotti, Giulio; Fagherazzi, Sergio
2013-04-02
High rates of wave-induced erosion along salt marsh boundaries challenge the idea that marsh survival is dictated by the competition between vertical sediment accretion and relative sea-level rise. Because waves pounding marshes are often locally generated in enclosed basins, the depth and width of surrounding tidal flats have a pivoting control on marsh erosion. Here, we show the existence of a threshold width for tidal flats bordering salt marshes. Once this threshold is exceeded, irreversible marsh erosion takes place even in the absence of sea-level rise. This catastrophic collapse occurs because of the positive feedbacks among tidal flat widening by wave-induced marsh erosion, tidal flat deepening driven by wave bed shear stress, and local wind wave generation. The threshold width is determined by analyzing the 50-y evolution of 54 marsh basins along the US Atlantic Coast. The presence of a critical basin width is predicted by a dynamic model that accounts for both horizontal marsh migration and vertical adjustment of marshes and tidal flats. Variability in sediment supply, rather than in relative sea-level rise or wind regime, explains the different critical width, and hence erosion vulnerability, found at different sites. We conclude that sediment starvation of coastlines produced by river dredging and damming is a major anthropogenic driver of marsh loss at the study sites and generates effects at least comparable to the accelerating sea-level rise due to global warming.
Optimizing ZnS/6LiF scintillators for wavelength-shifting-fiber neutron detectors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Crow, Lowell; Funk, Loren L; Hannan, Bruce W
2016-01-01
In this paper we compare the performance of grooved and flat ZnS/6LiF scintillators in a wavelength shifting-fiber (WLSF) detector. Flat ZnS/6LiF scintillators with the thickness L=0.2-0.8 mm were characterized using photon counting and pulse-height analysis and compared to a grooved scintillator of approximately 0.8 mm thick. While a grooved scintillator considerably increases the apparent thickness of the scintillator to neutrons for a given coating thickness, we find that the flat scintillators perform better than the grooved scintillators in terms of both light yield and neutron detection efficiency. The flat 0.8-mm-thick scintillator has the highest light output, and it is 52%more » higher compared with a grooved scintillator of same thickness. The lower light output of the grooved scintillator as compared to the flat scintillator is consistent with the greater scintillator-WLSF separation and the much larger average emission angle of the grooved scintillator. We also find that the average light cone width, or photon travel-length as measured using time-of-flight powder diffraction of diamond and vanadium, decreases with increasing L in the range of L=0.6-0.8 mm. This result contrasts with the traditional Swank diffusion model for micro-composite scintillators, and could be explained by a decrease in photon diffusion-coefficient or an increase in micro-particle content in the flat scintillator matrix for the thicker scintillators.« less
Is flat fielding safe for precision CCD astronomy?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Baumer, Michael; Davis, Christopher P.; Roodman, Aaron
The ambitious goals of precision cosmology with wide-field optical surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST) demand precision CCD astronomy as their foundation. This in turn requires an understanding of previously uncharacterized sources of systematic error in CCD sensors, many of which manifest themselves as static effective variations in pixel area. Such variation renders a critical assumption behind the traditional procedure of flat fielding—that a sensor's pixels comprise a uniform grid—invalid. In this work, we present a method to infer a curl-free model of a sensor's underlying pixel grid from flat-field images,more » incorporating the superposition of all electrostatic sensor effects—both known and unknown—present in flat-field data. We use these pixel grid models to estimate the overall impact of sensor systematics on photometry, astrometry, and PSF shape measurements in a representative sensor from the Dark Energy Camera (DECam) and a prototype LSST sensor. Applying the method to DECam data recovers known significant sensor effects for which corrections are currently being developed within DES. For an LSST prototype CCD with pixel-response non-uniformity (PRNU) of 0.4%, we find the impact of "improper" flat fielding on these observables is negligible in nominal .7'' seeing conditions. Furthermore, these errors scale linearly with the PRNU, so for future LSST production sensors, which may have larger PRNU, our method provides a way to assess whether pixel-level calibration beyond flat fielding will be required.« less
Is flat fielding safe for precision CCD astronomy?
Baumer, Michael; Davis, Christopher P.; Roodman, Aaron
2017-07-06
The ambitious goals of precision cosmology with wide-field optical surveys such as the Dark Energy Survey (DES) and the Large Synoptic Survey Telescope (LSST) demand precision CCD astronomy as their foundation. This in turn requires an understanding of previously uncharacterized sources of systematic error in CCD sensors, many of which manifest themselves as static effective variations in pixel area. Such variation renders a critical assumption behind the traditional procedure of flat fielding—that a sensor's pixels comprise a uniform grid—invalid. In this work, we present a method to infer a curl-free model of a sensor's underlying pixel grid from flat-field images,more » incorporating the superposition of all electrostatic sensor effects—both known and unknown—present in flat-field data. We use these pixel grid models to estimate the overall impact of sensor systematics on photometry, astrometry, and PSF shape measurements in a representative sensor from the Dark Energy Camera (DECam) and a prototype LSST sensor. Applying the method to DECam data recovers known significant sensor effects for which corrections are currently being developed within DES. For an LSST prototype CCD with pixel-response non-uniformity (PRNU) of 0.4%, we find the impact of "improper" flat fielding on these observables is negligible in nominal .7'' seeing conditions. Furthermore, these errors scale linearly with the PRNU, so for future LSST production sensors, which may have larger PRNU, our method provides a way to assess whether pixel-level calibration beyond flat fielding will be required.« less
Active noise control using a distributed mode flat panel loudspeaker.
Zhu, H; Rajamani, R; Dudney, J; Stelson, K A
2003-07-01
A flat panel distributed mode loudspeaker (DML) has many advantages over traditional cone speakers in terms of its weight, size, and durability. However, its frequency response is uneven and complex, thus bringing its suitability for active noise control (ANC) under question. This paper presents experimental results demonstrating the effective use of panel DML speakers in an ANC application. Both feedback and feedforward control techniques are considered. Effective feedback control with a flat panel speaker could open up a whole range of new noise control applications and has many advantages over feedforward control. The paper develops a new control algorithm to attenuate tonal noise of a known frequency by feedback control. However, due to the uneven response of the speakers, feedback control is found to be only moderately effective even for this narrow-band application. Feedforward control proves to be most capable for the flat panel speaker. Using feedforward control, the sound pressure level can be significantly reduced in close proximity to an error microphone. The paper demonstrates an interesting application of the flat panel in which the panel is placed in the path of sound and effectively used to block sound transmission using feedforward control. This is a new approach to active noise control enabled by the use of flat panels and can be used to prevent sound from entering into an enclosure in the first place rather than the traditional approach of attempting to cancel sound after it enters the enclosure.
Magnetotelluric Data, Central Yucca Flat, Nevada Test Site, Nevada
DOE Office of Scientific and Technical Information (OSTI.GOV)
J.M. Williams; B.D. Rodriguez, and T.H. Asch
2005-11-23
Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Central Yucca Flat, Profile 1, as shown in figure 1. No interpretation of the data is included here.« less
Magnetotelluric Data, North Central Yucca Flat, Nevada Test Site, Nevada
DOE Office of Scientific and Technical Information (OSTI.GOV)
J.M. Williams; B.D. Rodriguez, and T.H. Asch
2005-11-23
Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for north central Yucca Flat, Profile 7, as shown in Figure 1. No interpretation of the data is included here.« less
Magnetotelluric Data, Northern Frenchman Flat, Nevada Test Site Nevada
DOE Office of Scientific and Technical Information (OSTI.GOV)
J.M. Williams; B.D. Rodriguez, and T. H. Asch
2005-11-23
Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Frenchman Flat Profile 3, as shown in Figure 1. No interpretation of the data is included here.« less
Magnetotelluric Data, Southern Yucca Flat, Nevada Test Site, Nevada
DOE Office of Scientific and Technical Information (OSTI.GOV)
J.M. Williams; B.D. Rodriguez, and T.H. Asch
2005-11-23
Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Southern Yucca Flat, Profile 4, as shown in Figure 1. No interpretation of the data is included here.« less
Magnetotelluric Data, Northern Yucca Flat, Nevada Test Site, Nevada
DOE Office of Scientific and Technical Information (OSTI.GOV)
J.M. Williams; B.D. Rodriguez, and T.H. Asch
2005-11-23
Nuclear weapons are integral to the defense of the United States. The U.S. Department of Energy, as the steward of these devices, must continue to gauge the efficacy of the individual weapons. This could be accomplished by occasional testing at the Nevada Test Site (NTS) in Nevada, northwest of Las Vegas. Yucca Flat Basin is one of the testing areas at the NTS. One issue of concern is the nature of the somewhat poorly constrained pre-Tertiary geology and its effects on ground-water flow in the area subsequent to a nuclear test. Ground-water modelers would like to know more about themore » hydrostratigraphy and geologic structure to support a hydrostratigraphic framework model that is under development for the Yucca Flat Corrective Action Unit (CAU). During 2003, the U.S. Geological Survey (USGS) collected and processed Magnetotelluric (MT) and Audio-magnetotelluric (AMT) data at the Nevada Test Site in and near Yucca Flat to help characterize this pre-Tertiary geology. That work will help to define the character, thickness, and lateral extent of pre-Tertiary confining units. In particular, a major goal has been to define the upper clastic confining unit (UCCU) in the Yucca Flat area. Interpretation will include a three-dimensional (3-D) character analysis and two-dimensional (2-D) resistivity model. The purpose of this report is to release the MT sounding data for Profile 2, (fig. 1), located in the northern Yucca Flat area. No interpretation of the data is included here.« less
Beam shaping optics to enhance performance of interferometry techniques in grating manufacture
NASA Astrophysics Data System (ADS)
Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei
2018-02-01
Improving of industrial holographic and interferometry techniques is of great importance in interference lithography, computer-generated holography, holographic data storage, interferometry recording of Bragg gratings as well as gratings of various types in semiconductor industry. Performance of mentioned techniques is essentially enhanced by providing a light beam with flat phase front and flat-top irradiance distribution. Therefore, transformation of Gaussian distribution of a TEM00 laser to flat-top (top hat, uniform) distribution is an important optical task. There are different refractive and diffractive beam shaping approaches used in laser industrial and scientific applications, but only few of them are capable to fulfil the optimum conditions for beam quality demanding holography and interferometry. As a solution it is suggested to apply refractive field mapping beam shaping optics πShaper, which operational principle presumes almost lossless transformation of Gaussian to flat-top beam with flatness of output wavefront, conserving of beam consistency, providing collimated low divergent output beam, high transmittance, extended depth of field, negligible wave aberration, and achromatic design provides capability to work with several lasers with different wavelengths simultaneously. High optical quality of resulting flat-top beam allows applying additional optical components to build various imaging optical systems for variation of beam size and shape to fulfil requirements of a particular application. This paper will describe design basics of refractive beam shapers and optical layouts of their applying in holography and laser interference lithography. Examples of real implementations and experimental results will be presented as well.
NASA Astrophysics Data System (ADS)
Jing, Lin; Han, Liangliang
2017-12-01
A comprehensive dynamic finite-element simulation method was proposed to study the wheel-rail impact response induced by a single wheel flat based on a 3-D rolling contact model, where the influences of the structural inertia, strain rate effect of wheel-rail materials and thermal stress due to the wheel-rail sliding friction were considered. Four different initial conditions (i.e. pure mechanical loading plus rate-independent, pure mechanical loading plus rate-dependent, thermo-mechanical loading plus rate-independent, and thermo-mechanical loading plus rate-dependent) were involved into explore the corresponding impact responses in term of the vertical impact force, von-Mises equivalent stress, equivalent plastic strain and shear stress. Influences of train speed, flat length and axle load on the flat-induced wheel-rail impact response were discussed, respectively. The results indicate that the maximum thermal stresses are occurred on the tread of the wheel and on the top surface of the middle rail; the strain rate hardening effect contributes to elevate the von-Mises equivalent stress and restrain the plastic deformation; and the initial thermal stress due to the sliding friction will aggravate the plastic deformation of wheel and rail. Besides, the wheel-rail impact responses (i.e. impact force, von-Mises equivalent stress, equivalent plastic strain, and XY shear stress) induced by a flat are sensitive to the train speed, flat length and axle load.
Rivera-Saldívar, G; Torres-González, R; Franco-Valencia, M; Ríos-Monroy, R; Martínez-Ramírez, F; Pérez-Hernández, E; Duarte-Dagnino, D
2012-01-01
The investigation on the medial longitudinal arch is aimed at addressing the diagnostic problems of flat foot. The diagnosis is currently based on clinical tests and the appropriate identification of both postural and gait abnormalities. Risk factors are associated with pre-school ages, but there is no adequate analysis of such factors during school ages, when the longitudinal arch reaches its conformational maturity. Probabilistic methods were used to obtain a sample of 476 patients from elementary schools in the Federal District and the state of Puebla. Once the approval of the research committee was obtained, an analytical, prospective, cross-sectional study was conducted. Anthropometric measurements were performed, together with anamnesis, physical exam of the students, and conventional wet footprint analysis in a standardized and duplicate way. Of the 476 patients, 101 had flat foot (21.2%) and 49 of them had pain symptoms in the feet, knees or both (48.5%), accounting for 10.2% of the patients examined. Forefoot pronation and valgus hindfoot resulted in an increased risk of symptomatic flat foot in the school population in the study. In cases of flat or cavus foot, the presence of foot and/or knee pain symptoms in the school population was associated in a statistically significant way with one or more of the factors analyzed (overweight, genu valgus, valgus hindfoot, forefoot pronation and claw toes). Girls with such factors had a 3-7 higher chance of having symptomatic flat foot.
Use of vertical temperature gradients for prediction of tidal flat sediment characteristics
Miselis, Jennifer L.; Holland, K. Todd; Reed, Allen H.; Abelev, Andrei
2012-01-01
Sediment characteristics largely govern tidal flat morphologic evolution; however, conventional methods of investigating spatial variability in lithology on tidal flats are difficult to employ in these highly dynamic regions. In response, a series of laboratory experiments was designed to investigate the use of temperature diffusion toward sediment characterization. A vertical thermistor array was used to quantify temperature gradients in simulated tidal flat sediments of varying compositions. Thermal conductivity estimates derived from these arrays were similar to measurements from a standard heated needle probe, which substantiates the thermistor methodology. While the thermal diffusivities of dry homogeneous sediments were similar, diffusivities for saturated homogeneous sediments ranged approximately one order of magnitude. The thermal diffusivity of saturated sand was five times the thermal diffusivity of saturated kaolin and more than eight times the thermal diffusivity of saturated bentonite. This suggests that vertical temperature gradients can be used for distinguishing homogeneous saturated sands from homogeneous saturated clays and perhaps even between homogeneous saturated clay types. However, experiments with more realistic tidal flat mixtures were less discriminating. Relationships between thermal diffusivity and percent fines for saturated mixtures varied depending upon clay composition, indicating that clay hydration and/or water content controls thermal gradients. Furthermore, existing models for the bulk conductivity of sediment mixtures were improved only through the use of calibrated estimates of homogeneous end-member conductivity and water content values. Our findings suggest that remotely sensed observations of water content and thermal diffusivity could only be used to qualitatively estimate tidal flat sediment characteristics.
Splines and polynomial tools for flatness-based constrained motion planning
NASA Astrophysics Data System (ADS)
Suryawan, Fajar; De Doná, José; Seron, María
2012-08-01
This article addresses the problem of trajectory planning for flat systems with constraints. Flat systems have the useful property that the input and the state can be completely characterised by the so-called flat output. We propose a spline parametrisation for the flat output, the performance output, the states and the inputs. Using this parametrisation the problem of constrained trajectory planning can be cast into a simple quadratic programming problem. An important result is that the B-spline parametrisation used gives exact results for constrained linear continuous-time system. The result is exact in the sense that the constrained signal can be made arbitrarily close to the boundary without having intersampling issues (as one would have in sampled-data systems). Simulation examples are presented, involving the generation of rest-to-rest trajectories. In addition, an experimental result of the method is also presented, where two methods to generate trajectories for a magnetic-levitation (maglev) system in the presence of constraints are compared and each method's performance is discussed. The first method uses the nonlinear model of the plant, which turns out to belong to the class of flat systems. The second method uses a linearised version of the plant model around an operating point. In every case, a continuous-time description is used. The experimental results on a real maglev system reported here show that, in most scenarios, the nonlinear and linearised models produce almost similar, indistinguishable trajectories.
NASA Astrophysics Data System (ADS)
Jollivet, C.; Farley, K.; Conroy, M.; Abramczyk, J.; Belke, S.; Becker, F.; Tankala, K.
2016-03-01
Single-mode (SM) kW-class fiber lasers are the tools of choice for material processing applications such as sheet metal cutting and welding. However, application requirements include a flat-top intensity profile and specific beam parameter product (BPP). Here, Nufern introduces a novel specialty fiber technology capable of converting a SM laser beam into a flat-top beam suited for these applications. The performances are demonstrated using a specialty fiber with 100 μm pure silica core, 0.22 NA surrounded by a 120 μm fluorine-doped layer and a 360 μm pure silica cladding, which was designed to match the conventional beam delivery fibers. A SM fiber laser operating at a wavelength of 1.07 μm and terminated with a large-mode area (LMA) fiber with 20 μm core and 0.06 NA was directly coupled in the core of the flat-top specialty fiber using conventional splicing technique. The output beam profile and BPP were characterized first with a low-power source and confirmed using a 2 kW laser and we report a beam transformation from a SM beam into a flat-top intensity profile beam with a 3.8 mm*mrad BPP. This is, to the best of our knowledge, the first successful beam transformation from SM to MM flat-top with controlled BPP in a single fiber integrated in a multi-kW all-fiber system architecture.
NASA Astrophysics Data System (ADS)
Diabil, Hayder Azeez; Li, Xin Kai; Abdalla, Ibrahim Elrayah
2017-09-01
Large-scale organized motions (commonly referred to coherent structures) and flow topology of a transitional separated-reattached flow have been visualised and investigated using flow visualisation techniques. Two geometrical shapes including two-dimensional flat plate with rectangular leading edge and three-dimensional square cylinder are chosen to shed a light on the flow topology and present coherent structures of the flow over these shapes. For both geometries and in the early stage of the transition, two-dimensional Kelvin-Helmholtz rolls are formed downstream of the leading edge. They are observed to be twisting around the square cylinder while they stay flat in the case of the two-dimensional flat plate. For both geometrical shapes, the two-dimensional Kelvin-Helmholtz rolls move downstream of the leading edge and they are subjected to distortion to form three-dimensional hairpin structures. The flow topology in the flat plate is different from that in the square cylinder. For the flat plate, there is a merging process by a pairing of the Kelvin-Helmholtz rolls to form a large structure that breaks down directly into many hairpin structures. For the squire cylinder case, the Kelvin-Helmholtz roll evolves topologically to form a hairpin structure. In the squire cylinder case, the reattachment length is much shorter and a forming of the three-dimensional structures is closer to the leading edge than that in the flat plate case.
Effect of gold photocathode contamination on a flat spectral response X-ray diode
NASA Astrophysics Data System (ADS)
Wang, Kun-lun; Zhang, Si-qun; Zhou, Shao-tong; Huang, Xian-bin; Ren, Xiao-dong; Dan, Jia-kun; Xu, Qiang
2018-03-01
A detector with an approximately flat spectral response is important for diagnosing intense thermal X-ray flux. A flat-spectral-response X-ray diode (FSR-XRD) utilizes a gold photocathode X-ray diode and a specially configured gold filter to give rise to a nearly flat spectral response in the photon energy range of 100-4000 eV. It has been observed that the spectral responses of several FSR-XRDs changed after a few shots of z-pinch experiments on the Primary Test Stand facility. This paper presents an analysis of the changes by fitting the spectral responses of the gold photocathodes using a model with a free parameter which characterizes the thickness of the contamination. The spectral responses of FSR-XRDs were calibrated with synchrotron radiation, and several cleaning methods were tested with the calibration. Considering the results of model and cleaning, it may be anticipated that contamination was the major reason of the response changing. Contamination worsened the flatness of the spectral response of the FSR-XRD and decreased the averaged response, hence it is important to avoid contamination. Current results indicate a requirement of further study of the contamination.
NASA Astrophysics Data System (ADS)
Kegerise, Michael A.; Rufer, Shann J.
2016-08-01
In this paper, we report on the application of the atomic layer thermopile (ALTP) heat-flux sensor to the measurement of laminar-to-turbulent transition in a hypersonic flat-plate boundary layer. The centerline of the flat-plate model was instrumented with a streamwise array of ALTP sensors, and the flat-plate model was exposed to a Mach 6 freestream over a range of unit Reynolds numbers. Here, we observed an unstable band of frequencies that are associated with second-mode instability waves in the laminar boundary layer that forms on the flat-plate surface. The measured frequencies, group velocities, phase speeds, and wavelengths of these instability waves are consistent with data previously reported in the literature. Heat flux time series, and the Morlet wavelet transforms of them, revealed the wave-packet nature of the second-mode instability waves. In addition, a laser-based radiative heating system was used to measure the frequency response functions (FRF) of the ALTP sensors used in the wind tunnel test. These measurements were used to assess the stability of the sensor FRFs over time and to correct spectral estimates for any attenuation caused by the finite sensor bandwidth.
Low-bias flat band-stop filter based on velocity modulated gaussian graphene superlattice
NASA Astrophysics Data System (ADS)
Sattari-Esfahlan, S. M.; Shojaei, S.
2018-05-01
Transport properties of biased planar Gaussian graphene superlattice (PGGSL) with Fermi velocity barrier is investigated by transfer matrix method (TMM). It is observed that enlargement of bias voltage over miniband width breaks the miniband to WSLs leads to suppressing resonant tunneling. Transmission spectrum shows flat wide stop-band property controllable by external bias voltage with stop-band width of near 200 meV. The simulations demonstrate that strong velocity barriers prevent tunneling of Dirac electrons leading to controllable enhancement of stop-band width. By increasing ratio of Fermi velocity in barriers to wells υc stop-band width increase. As wide transmission stop-band width (BWT) of filter is tunable from 40 meV to 340 meV is obtained by enhancing ratio of υc from 0.2 to 1.5, respectively. Proposed structure suggests easy tunable wide band-stop electronic filter with a modulated flat stop-band characteristic by height of electrostatic barrier and structural parameters. Robust sensitivity of band width to velocity barrier intensity in certain bias voltages and flat band feature of proposed filter may be opens novel venue in GSL based flat band low noise filters and velocity modulation devices.