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Sample records for calvert bluff formation

  1. Stratigraphy of the Calvert Bluff Formation of the Wilcox Group, Brazos County, Texas 

    E-print Network

    May, Audrey Gail

    1994-01-01

    Wilcox Group sediments are classified into three main formations: a lower Hooper Formation, a middle Simsboro Formation, and an upper Calvert Bluff Formation. The Calvert Bluff and Simsboro formations have been interpreted as fluvial...

  2. Facies architecture of the upper Calvert Bluff Formation exposed in the highwall of Big Brown Mine, Fairfield, Texas 

    E-print Network

    Sturdy, Michael Dale

    2006-10-30

    The facies architecture and geometry of stratigraphic surfaces within a lignite bearing interval of the Paleocene upper Calvert Bluff Formation is mapped on a photomosaic of the 150 ft (50 m) high and 12,000 ft (4km) long �C� area highwall...

  3. The origin and distribution of HAPs elements in relation to maceral composition of the A1 lignite bed (Paleocene, Calvert Bluff Formation, Wilcox Group), Calvert mine area, east-central Texas

    USGS Publications Warehouse

    Crowley, S.S.; Warwick, P.D.; Ruppert, L.F.; Pontolillo, J.

    1997-01-01

    The origin and distribution of twelve potentially Hazardous Air Pollutants (HAPs; As, Be, Cd, Cr, Co, Hg, Mn, Ni, Pb Sb, Se, and U) identified in the 1990 Clean Air Act Amendments were examined in relation to the maceral composition of the A1 bed (Paleocene, Calvert Bluff Formation, Wilcox Group) of the Calvert mine in east-central Texas. The 3.2 m-thick A1 bed was divided into nine incremental channel samples (7 lignite samples and 2 shaley coal samples) on the basis of megascopic characteristics. Results indicate that As, Cd, Cr, Ni, Pb, Sb, and U are strongly correlated with ash yield and are enriched in the shaley coal samples. We infer that these elements are associated with inorganic constituents in the coal bed and may be derived from a penecontemporaneous stream channel located several kilometers southeast of the mining block. Of the HAPs elements studied, Mn and Hg are the most poorly correlated to ash yield. We infer an organic association for Mn; Hg may be associated with pyrite. The rest of the trace elements (Be, Co, and Se) are weakly correlated with ash yield. Further analytical work is necessary to determine the mode of occurrence for these elements. Overall, concentrations of the HAPs elements are generally similar to or less than those reported in previous studies of lignites of the Wilcox Group, east-central region, Texas. Petrographic analysis indicates the following ranges in composition for the seven lignite samples: liptinites (5-8%), huminites (88-95%), and inertinites (trace amounts to 7%). Samples from the middle portion of the A1 bed contain abundant crypto-eugelinite compared to the rest of the samples; this relationship suggests that the degradation of plant material was an important process during the development of the peat mire. With the exception of Hg and Mn, relatively low levels of the HAPs elements studied are found in the samples containing abundant crypto-eugelinite. We infer that the peat-forming environment for this portion of the coal bed was very wet with minimal detrital input. Relatively high concentrations of crypto-humotelinite were found in samples from the top and base of the coal bed. The presence of abundant crypto-humotelinite in this part of the coal bed suggests the accumulation of wood-rich peat under conditions conducive to a high degree of tissue preservation in the peat mire. Although several of the trace elements (Be, Co, Ni, and Sb) exhibit enrichment in these samples, they are not necessarily chemically associated with humotelinite. We infer that these elements, with the exception of Be, are possibly associated with deposition of the roof and floor rock of the coal bed; however, further analytical work would be necessary to confirm this hypothesis. Beryllium may have an organic origin. ?? 1997 Elsevier Science B.V.

  4. Coal geology of the Paleocene-Eocene Calvert Bluff Formation (Wilcox Group) and the Eocene Manning Formation (Jackson Group) in east-central Texas; field trip guidebook for the Society for Organic Petrology, Twelfth Annual Meeting, The Woodlands, Texas, August 30, 1995

    USGS Publications Warehouse

    Warwick, Peter D.; Crowley, Sharon S.

    1995-01-01

    The Jackson and Wilcox Groups of eastern Texas (fig. 1) are the major lignite producing intervals in the Gulf Region. Within these groups, the major lignite-producing formations are the Paleocene-Eocene Calvert Bluff Formation (Wilcox) and the Eocene Manning Formation (Jackson). According to the Keystone Coal Industry Manual (Maclean Hunter Publishing Company, 1994), the Gulf Coast basin produces about 57 million short tons of lignite annually. The state of Texas ranks number 6 in coal production in the United States. Most of the lignite is used for electric power generation in mine-mouth power plant facilities. In recent years, particular interest has been given to lignite quality and the distribution and concentration of about a dozen trace elements that have been identified as potential hazardous air pollutants (HAPs) by the 1990 Clean Air Act Amendments. As pointed out by Oman and Finkelman (1994), Gulf Coast lignite deposits have elevated concentrations of many of the HAPs elements (Be, Cd, Co, Cr, Hg, Mn, Se, U) on a as-received gm/mmBtu basis when compared to other United States coal deposits used for fuel in thermo-electric power plants. Although regulations have not yet been established for acceptable emissions of the HAPs elements during coal burning, considerable research effort has been given to the characterization of these elements in coal feed stocks. The general purpose of the present field trip and of the accompanying collection of papers is to investigate how various aspects of east Texas lignite geology might collectively influence the quality of the lignite fuel. We hope that this collection of papers will help future researchers understand the complex, multifaceted interrelations of coal geology, petrology, palynology and coal quality, and that this introduction to the geology of the lignite deposits of east Texas might serve as a stimulus for new ideas to be applied to other coal basins in the U.S. and abroad.

  5. Wind Erosion and Dune Formation on High Frozen Bluffs

    NASA Technical Reports Server (NTRS)

    Marsh, W. M.; Marsh, B. D.

    1984-01-01

    Frost penetration increases upslope on barren, windswept bluffs in cold environments. Along the south shore of Lake Superior, near the brow of 100 m high bluffs it typically exceeds 5 m. Frost increases the shear strength of damp sand to a level comparable to that of concrete, making winter slopes highly stable despite undercutting by waves and ground-water sapping along the footslope. Sublimation of interparticle ice in the slope face increases with wind speed and lower vapor pressures. The cold and dry winter winds of Lake Superior ablate these slopes through loss of binding ice. Wind erosion rates, based on measurements of sand accumulation on the forest floor downwind of the brow, show most airborne sand falls out within several meters of the brow, forming a berm 1 to 3 m high after many years. The spatial pattern of sand deposition, however, varies considerably over distances of several hundred meters along the top bluffs in response to frost conditions and the build-up of gravel lag on the slope face, sand exposure from mass movements, and local aerodynamics of the crest slope. The formation of perched sand dunes in the Great Lakes region is clearly related to wind erosion of sand from high bluffs in winter. Broadly similar processes may operate on Mars.

  6. Stratigraphy and Facies of Cretaceous Schrader Bluff and Prince Creek Formations in Colville River Bluffs, North Slope, Alaska

    USGS Publications Warehouse

    Flores, Romeo M.; Myers, Mark D.; Houseknecht, David W.; Stricker, Gary D.; Brizzolara, Donald W.; Ryherd, Timothy J.; Takahashi, Kenneth I.

    2007-01-01

    Stratigraphic and sedimentologic studies of facies of the Upper Cretaceous rocks along the Colville River Bluffs in the west-central North Slope of Alaska identified barrier shoreface deposits consisting of vertically stacked, coarsening-upward parasequences in the Schrader Bluff Formation. This vertical stack of parasequence deposits represents progradational sequences that were affected by shoaling and deepening cycles caused by fluctuations of sea level. Further, the vertical stack may have served to stabilize accumulation of voluminous coal deposits in the Prince Creek Formation, which formed braided, high-sinuosity meandering, anastomosed, and low-sinuosity meandering fluvial channels and related flood plain deposits. The erosional contact at the top of the uppermost coarsening-upward sequence, however, suggests a significant drop of base level (relative sea level) that permitted a semiregional subaerial unconformity to develop at the contact between the Schrader Bluff and Prince Creek Formations. This drop of relative sea level may have been followed by a relative sea-level rise to accommodate coal deposition directly above the unconformity. This rise was followed by a second drop of relative sea level, with formation of incised valley topography as much as 75 ft deep and an equivalent surface of a major marine erosion or mass wasting, or both, either of which can be traced from the Colville River Bluffs basinward to the subsurface in the west-central North Slope. The Prince Creek fluvial deposits represent late Campanian to late Maastrichtian depositional environments that were affected by these base level changes influenced by tectonism, basin subsidence, and sea-level fluctuations.

  7. Pumice in the interglacial Whidbey Formation at Blowers Bluff, central Whidbey Island, WA, USA

    USGS Publications Warehouse

    Dethier, D.P.; Dragovich, J.D.; Sarna-Wojcicki, A. M.; Fleck, R.J.

    2008-01-01

    A new 40Ar/39Ar age of 128??9 ka and chemical analyses of pumice layers from interglacial alluvium at Blowers Bluff, Whidbey Island, WA, show that the deposits are part of the Whidbey Formation, a widespread, mainly subsurface unit. Glass chemistry of the dated dacitic pumice does not match any analyzed northern Cascade source, but upper Pleistocene dacites from Glacier Peak and early Pleistocene silicic rocks from the Kulshan caldera are chemically similar. The chemistry of pumiceous dacite in younger units, including the latest Pleistocene Partridge Gravel, is similar to that of the dated material. The deep troughs of the modern northern Puget lowland must have been filled during deposition of the Whidbey Formation, allowing volcanic-rich sediment to reach what is now Whidbey Island. Topographic analysis of LIDAR images demonstrates that extensive erosion occurred during latest Pleistocene ice retreat. The Partridge Gravel likely records subglacial fluvial erosion along an ice tunnel and ice-marginal deposition into adjacent marine waters. Pumice in the Partridge Gravel probably was reworked from stratigraphically and topographically lower deposits, including those at Blowers Bluff. ?? 2007 Elsevier Ltd and INQUA.

  8. Bluff formation and long-term recession rates, southwestern Lake Michigan

    SciTech Connect

    Rovey, C.W. II )

    1992-01-01

    Where eroding cohesive sediments are present, Lake Michigan bluffs range up to 140 ft. in height and expose multiple stratigraphic units. According to the model presented here, bluffs form as a wave cut terrace erodes inland from a point near the original shoreline. The erosion plane is nearly horizontal, in contrast with the eastward dip of the glacial units inherited from underlying bedrock. Therefore, terraces eroding inland (west) produce progressively higher bluffs and expose successively older units at the toe and beneath the lake. This process repeated several times as lake levels sequentially dropped to their modern stage. The initial modern shoreline, and hence the width of the wave cut terrace, was determined from 4 offshore seismic profiles. It is picked as an inflection point in the slope of the lake bed, occurring offshore of dipping reflectors intersecting the lake bottom. The calculated average recession rate over the 2,500 year duration of the modern stage is 5 ft/yr in contrast to average rates of 2 ft/yr measured over the last century. Thus rates decrease through time as the terrace widens and wave energy is damped. By correlating bluff height to amount of recession of modern bluffs, a third rate of 12 ft/yr of the first 800 years of a recession is calculated for relict bluffs formed at the Nipissing II level. The 3 rates define a steeply decaying exponential curve in early stages of bluff retreat, flattening into a nearly linear function after 1,000 years.

  9. Sentinel Hill Core Test 1: Facies Descriptions and Stratigraphic Reinterpretations of the Prince Creek and Schrader Bluff Formations, North Slope, Alaska

    USGS Publications Warehouse

    Flores, Romeo M.; Stricker, Gary D.; Decker, Paul L.; Myers, Mark D.

    2007-01-01

    The Sentinel Hill Core Test 1 well penetrated an intertonguing sequence of (1) the marine Schrader Bluff Formation in the depth intervals 950?1,180 ft and 690?751 ft, which consists of shoreface and offshore deposits that accumulated along a storm-dominated, barred shoreline; and (2) the nonmarine Prince Creek Formation in the depth intervals 751?950 ft and surface to 690 ft, which consists of fluvial channel, crevasse splay, backswamp, and ash fall deposits. The strata range in age from early Campanian to early Maastrichtian. An erosional contact at a depth of 690 ft at the base of the upper unit of the Prince Creek Formation is interpreted as a major regional sequence boundary, and the overlying conglomeratic fluvial channel deposits are interpreted to have accumulated in a paleovalley. In its more proximal reaches along the Colville River, channels of this paleovalley cut down 75 ft into the lowermost Prince Creek Formation and the uppermost Schrader Bluff Formation. Farther offshore, the equivalent surface to the aforementioned paleovalley appears to be a subtle discontinuity between middle and lower Schrader Bluff Formation shelfal marine strata. Still farther offshore, the equivalent paleovalley surface is interpreted as a marine mass-wasting surface that locally cuts through the lowermost Schrader Bluff Formation and into the underlying Seabee Formation.

  10. Bluff evolution along coastal drumlins: Boston Harbor Islands, Massachusetts

    USGS Publications Warehouse

    Himmelstoss, E.A.; FitzGerald, D.M.; Rosen, P.S.; Allen, J.R.

    2006-01-01

    A series of partially drowned drumlins forms the backbone of the inner islands within Boston Harbor. The shoreline of these rounded glacial deposits is composed of actively retreating bluffs formed by continual wave attack. Comparisons of bluffs reveal variability in their height and lateral extent, as well as in the dominant mechanism causing their retreat. Two processes are responsible for bluff erosion and yield distinct bluff morphologies: (1) wave attack undercuts the bluff and causes episodic slumping, yielding planar bluff slopes, and (2) subaerial processes such as rainfall create irregular slopes characterized by rills and gullies. We propose a model of drumlin bluff evolution that is based on processes of erosion and physical characteristics such as bluff height, slope morphology, and the orientation of the bluff with respect to the long axis of the drumlin and its topographic crest. The four phases of drumlin bluff evolution consist of (1) initial formation of bluff, with retreat dominated by wave notching and slumping processes; (2) rill and gully development as bluff heights exceed 10 m and slumped sediment at bluff base inhibits wave attack; (3) return of wave notching and slumping as bluff heights decrease; and (4) final development of boulder retreat lag as last remnants of drumlin are eroded by wave action. These phases capture the important physical processes of drumlin evolution in Boston Harbor and could apply to other eroding coastal drumlin deposits.

  11. 33 CFR 165.505 - Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland. ...District § 165.505 Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland....

  12. 76 FR 39908 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2; Calvert.... DPR-53 and DPR-69, for the Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 (CCNPP), respectively... (ISFSI), currently held by Calvert Cliffs Nuclear Power Plant, LLC as owner and licensed...

  13. 75 FR 66802 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-29

    ... Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2; Notice of... (the Commission) has granted the request of Calvert Cliffs Nuclear Power Plant, LLC, the licensee, to... and DPR-69 for the Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2, located in Calvert...

  14. 76 FR 4391 - Calvert Cliffs Nuclear Power Plant, LLC, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ... Calvert Cliffs Nuclear Power Plant, LLC, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2; Exemption 1.0 Background Calvert Cliffs Nuclear Power Plant, LLC, the licensee, is the holder of Facility Operating License Nos. DPR-53 and DPR-69 which authorizes operation of the Calvert Cliffs Nuclear...

  15. From Bluff to Backwater

    USGS Multimedia Gallery

    This is an aerial view of Pool 7 of the Mississippi River south of Trempealeau, WI. This photo highlights the different habitats for plants and wildlife from the bluffs that parallel the river to its quiet backwaters. Balanced with that is the fact that the Mississippi River is a commercial highway ...

  16. 76 FR 1469 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-10

    ...Calvert Cliffs Nuclear Power Plant, Unit Nos...for light-water nuclear power reactors,'' which...demonstrated that the effectiveness of the ECCS will...License Renewal of Nuclear Plants, Calvert Cliffs Nuclear Power Plant...

  17. 33 CFR 165.505 - Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland. 165.505 Section 165.505 Navigation and... Areas Fifth Coast Guard District § 165.505 Security Zone; Calvert Cliffs Nuclear Power Plant,...

  18. 76 FR 1469 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-10

    ... Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2... Cliffs Nuclear Power Plant, LLC, the licensee, for operation of the Calvert Cliffs Nuclear Power Plant... for light-water nuclear power reactors,'' which requires that the calculated emergency core...

  19. 33 CFR 165.505 - Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland. 165.505 Section 165.505 Navigation and... Areas Fifth Coast Guard District § 165.505 Security Zone; Calvert Cliffs Nuclear Power Plant,...

  20. 33 CFR 165.505 - Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland. 165.505 Section 165.505 Navigation and... Areas Fifth Coast Guard District § 165.505 Security Zone; Calvert Cliffs Nuclear Power Plant,...

  1. 33 CFR 165.505 - Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland. 165.505 Section 165.505 Navigation and... Areas Fifth Coast Guard District § 165.505 Security Zone; Calvert Cliffs Nuclear Power Plant,...

  2. A Bluff-Bidding Exercise

    ERIC Educational Resources Information Center

    Meister, J. Patrick

    2011-01-01

    Consider an auction in which one potential buyer wishes to participate, but the other potential buyer would rather the bidding not start. However, once bidding starts, the reluctant firm participates (submits "bluff bids") simply to make the eventual winner pay more. This incentive exists when the marginal effect of the winning bid is to increase…

  3. 33 CFR 165.505 - Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Security Zone; Calvert Cliffs Nuclear Power Plant, Chesapeake Bay, Calvert County, Maryland. 165.505 Section 165.505 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY REGULATED NAVIGATION AREAS AND LIMITED...

  4. 78 FR 41397 - Moss Bluff Hub, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-10

    ...ENERGY Federal Energy Regulatory Commission [Docket No. PR13-55-000] Moss Bluff Hub, LLC; Notice of Filing Take notice that on June 28, 2013, Moss Bluff Hub, LLC (Moss Bluff) filed a revised Statement of Operating Conditions (SOC)...

  5. 77 FR 70431 - Moss Bluff Hub, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-26

    ...Federal Energy Regulatory Commission [Docket No. PR13-10-000] Moss Bluff Hub, LLC; Notice of Filing Take notice that on November 15, 2012, Moss Bluff Hub, LLC, (Moss Bluff) filed to revise its Statement of Operating Conditions...

  6. Gosses Bluff impact structure, Australia.

    NASA Technical Reports Server (NTRS)

    Milton, D. J.; Barlow, B. C.; Brown, A. R.; Glikson, A. Y.; Manwaring, E. A.; Moss, F. J.; Sedmik, E. C. E.; Van Son, J.; Brett, R.; Young, G. A.

    1972-01-01

    A comprehensive study has been carried out of the Gosses Bluff structure in Central Australia, which is a typical cryptoexplosion structure. The study included detailed geologic mapping, and seismic reflection and refraction, gravity, aeromagnetic, and ground magnetic surveys. It is concluded that the structure is an eroded crater formed by a single nearly instantaneous shock event, and that the event can be explained only by impact.

  7. Red Bluff, Marion County, Mississippi: a Citronelle braided-stream deposit

    SciTech Connect

    Smith, M.L.; Meylan, M.A.

    1983-09-01

    Red Bluff is an erosional escarpment located on the western margin of the Pearl River flood plain in northwestern Marion County, Mississippi. The sand grains are composed primarily of quartz, with small amounts of heavy minerals and feldspar. The gravel is composed of varying percentages of chert, flint, jasper, rip-up clasts, quartz, and tripoli, including a small fraction of silicified Paleozoic fossils. Grain-size analysis of the sediment and investigation of the sedimentary structures suggest a braided-fluvial environment of deposition. The most conspicuous sedimentary structures at Red Bluff are graded bedding, low-angle to medium-angle cross-bedding, and well-developed paleochannels. A statistical comparison (discriminant analysis) of the seven most abundant heavy minerals of Red Bluff, with the same suite of heavy minerals found at the type section of the Citronelle Formation (Pliocene-Pleistocene), and outcrops of a known Miocene coarse clastic unit indicates a correlation of Red Bluff to the Citronelle Formation. These heavy minerals are kyanite, staurolite, rutile, tourmaline, zircon, black opaques (primarily ilmenite and magnetite), and white opaques (primarily leucoxene). The suite of heavy minerals present at Red Bluff belongs to the east Gulf province. This metamorphic assemblage of heavy minerals implies the source area of the sediments at Red Bluff to be the southern Appalachians. The silicified pebble-size Devonian-Mississippian fossils were derived most likely from formations flanking the southern Appalachians in northern Alabama.

  8. 76 FR 39908 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ...Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and...Opportunity for a Hearing AGENCY: Nuclear Regulatory...Constellation Nuclear Power Plants, LLC, CCNPP, and...filing of requests for hearing and petitions...

  9. 77 FR 47121 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Units 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-07

    ...accommodations for restorative sleep. Calvert Cliffs is located...12-hour shifts to maintain safe and secure operation during...sufficient period of restorative sleep for personnel. The relief...achieves and maintains a safe and secure status and...

  10. 77 FR 47121 - Calvert Cliffs Nuclear Power Plant, LLC; Calvert Cliffs Nuclear Power Plant, Units 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-07

    ... Consideration (73 FR 17148; March 31, 2008), states that ``Plant emergencies are extraordinary circumstances... for restorative sleep. Calvert Cliffs is located along the western shore of the Chesapeake Bay and can... arrangements for onsite reliefs and bunking in order to allow for a sufficient period of restorative sleep...

  11. 78 FR 41397 - Moss Bluff Hub, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-10

    ... Energy Regulatory Commission Moss Bluff Hub, LLC; Notice of Filing Take notice that on June 28, 2013, Moss Bluff Hub, LLC (Moss Bluff) filed a revised Statement of Operating Conditions (SOC) pursuant to sections 284.123 and 284.224 of the Commission's regulations, (18 CFR 284.123 and 284.224). Moss...

  12. 77 FR 70431 - Moss Bluff Hub, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-26

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Moss Bluff Hub, LLC; Notice of Filing Take notice that on November 15, 2012, Moss Bluff Hub, LLC, (Moss Bluff) filed to revise its Statement of Operating Conditions (SOC)...

  13. Interactions of bluff-body obstacles with turbulent airflows affecting evaporative fluxes from porous surfaces

    NASA Astrophysics Data System (ADS)

    Haghighi, Erfan; Or, Dani

    2015-11-01

    Bluff-body obstacles interacting with turbulent airflows are common in many natural and engineering applications (from desert pavement and shrubs over natural surfaces to cylindrical elements in compact heat exchangers). Even with obstacles of simple geometry, their interactions within turbulent airflows result in a complex and unsteady flow field that affects surface drag partitioning and transport of scalars from adjacent evaporating surfaces. Observations of spatio-temporal thermal patterns on evaporating porous surfaces adjacent to bluff-body obstacles depict well-defined and persistent zonation of evaporation rates that were used to construct a simple mechanistic model for surface-turbulence interactions. Results from evaporative drying of sand surfaces with isolated cylindrical elements (bluff bodies) subjected to constant turbulent airflows were in good agreement with model predictions for localized exchange rates. Experimental and theoretical results show persistent enhancement of evaporative fluxes from bluff-rough surfaces relative to smooth flat surfaces under similar conditions. The enhancement is attributed to formation of vortices that induce a thinner boundary layer over part of the interacting surface footprint. For a practical range of air velocities (0.5-4.0 m/s), low-aspect ratio cylindrical bluff elements placed on evaporating sand surfaces enhanced evaporative mass losses (relative to a flat surface) by up to 300% for high density of elements and high wind velocity, similar to observations reported in the literature. Concepts from drag partitioning were used to generalize the model and upscale predictions to evaporation from surfaces with multiple obstacles for potential applications to natural bluff-rough surfaces.

  14. Conversations with Rep. Ken Calvert. Interview by Frank Sietzen Jr.

    PubMed

    Calvert, Ken

    2005-07-01

    Rep. Calvert, chair of the House aeronautics and space subcommittee of the Science Committee, answers questions related to priorities for space in the current congressional session: the Vision for Space Exploration, development of the Crew Exploration Vehicle (CEV) and other heavy-lift launch vehicles, entrepreneurial alliances in the space transportation industry, the U.S. aerospace industry, space tourism, entrepreneurs and NASA, U.S. aeronautics research, a service mission to the Hubble Space Telescope, and priority military space programs. PMID:16044613

  15. The Hydrogen Economy as a Technological Bluff

    ERIC Educational Resources Information Center

    Vanderburg, Willem H.

    2006-01-01

    The hydrogen economy is a technological bluff in its implied assurance that, despite the accelerating pace at which we are depleting the remaining half of our fossil fuels, our energy future is secure. Elementary thermodynamic considerations are developed to show that a hydrogen economy is about as feasible as a perpetual motion machine. Hydrogen…

  16. 77 FR 10784 - Calvert Cliffs Nuclear Power Plant, LLC; Notice of Withdrawal of Application for Amendment to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-23

    ...NRC-2012-0045] Calvert Cliffs Nuclear Power Plant, LLC; Notice of Withdrawal...Operating License The U.S. Nuclear Regulatory Commission (the Commission...the request of Calvert Cliffs Nuclear Power Plant, LLC, the licensee, to...

  17. Particle size and X-ray analysis of Feldspar, Calvert, Ball, and Jordan soils

    NASA Technical Reports Server (NTRS)

    Chapman, R. S.

    1977-01-01

    Pipette analysis and X-ray diffraction techniques were employed to characterize the particle size distribution and clay mineral content of the feldspar, calvert, ball, and jordan soils. In general, the ball, calvert, and jordan soils were primarily clay size particles composed of kaolinite and illite whereas the feldspar soil was primarily silt-size particles composed of quartz and feldspar minerals.

  18. 77 FR 34093 - License Renewal for Calvert Cliffs Nuclear Power Plant, LLC's

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-08

    ... License Renewal for Calvert Cliffs Nuclear Power Plant, LLC's AGENCY: Nuclear Regulatory Commission... Cliffs Nuclear Power Plant site near Lusby, Maryland. The NRC has prepared an Environmental Assessment... dated September 17, 2010, Calvert Cliffs Nuclear Power Plant, LLC (CCNPP) submitted an application...

  19. 75 FR 21372 - Calvert Social Investment Fund, et al.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-23

    ... COMMISSION Calvert Social Investment Fund, et al.; Notice of Application April 19, 2010. AGENCY: Securities... invest in certain financial instruments. Applicants: Calvert Social Investment Fund (the ``Trust... following is a summary of the application. The complete application may be obtained via the Commission's...

  20. Geology and paleoecology of the Cottonwood Creek delta in the Eocene Tipton Tongue of the Green River Formation and a mammalian fauna from the Eocene Cathedral Bluffs Tongue of the Wasatch Formation, Southeast Washakie Basin, Wyoming

    SciTech Connect

    Roehler, H.W.; Hanley, J.H.; Honey, J.G.

    1988-01-01

    Nonmarine mollusks are used to interpret paleoenvironments and patterns of sedimentation of a fan delta on the east margin of Eocene Lake Gosiute. The delta is composed of a lens of quartzose sandstone intertongued with oil shale. Delta morphology is illustrated by cross sections and paleogeographic maps. A fossil fauna representing five mammalian orders is described and used to establish the age of parts of the Wasatch and Green River formations. There are three chapters in this bulletin.

  1. 78 FR 21930 - Moss Bluff Hub, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Moss Bluff Hub, LLC; Notice of Filing Take notice that on March 29, 2013, Moss Bluff Hub, LLC filed to revise its Statement of Operating Conditions to modify Sections 3.4.4,...

  2. 76 FR 10581 - Moss Bluff Hub, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-25

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Moss Bluff Hub, LLC; Notice of Filing Take notice that on February 11, 2011, Moss Bluff Hub, LLC filed to revise its Statement of General Terms and Standard Operating Conditions...

  3. 76 FR 10581 - Moss Bluff Hub, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-25

    ...DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR11-87-000] Moss Bluff Hub, LLC; Notice of Filing Take notice that on February 11, 2011, Moss Bluff Hub, LLC filed to revise its Statement of General Terms and Standard...

  4. 78 FR 21930 - Moss Bluff Hub, LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-12

    ...DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. PR13-45-000] Moss Bluff Hub, LLC; Notice of Filing Take notice that on March 29, 2013, Moss Bluff Hub, LLC filed to revise its Statement of Operating Conditions to modify...

  5. 77 FR 34093 - License Renewal for Calvert Cliffs Nuclear Power Plant, LLC's

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-08

    ...Programs, U.S. Nuclear Regulatory...Calvert Cliffs Nuclear Power Plant...safety; and waste management...significantly affect the quality of the human environment...2012. For the Nuclear Regulatory...Division of Waste...

  6. GPU accelerated simulations of bluff body flows using vortex particle methods

    E-print Network

    Cottet, Georges-Henri

    GPU accelerated simulations of bluff body flows using vortex particle methods Diego Rossinelli in press as: D. Rossinelli et al., GPU accelerated simulations of bluff body flows using vortex particle Penalization Bluff body flows a b s t r a c t We present a GPU accelerated solver for simulations of bluff body

  7. Overview from bluff east of facility. Note buildings #35 (left). ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overview from bluff east of facility. Note buildings #35 (left). #33 (center), and #31 A (right) VIEW WEST - Department of Energy, Grand Junction Office, 2597 B3/4 Road, Grand Junction, Mesa County, CO

  8. 77 FR 1748 - Atomic Safety and Licensing Board; Calvert Cliffs 3 Nuclear Project, LLC, and UniStar Nuclear...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... Meetings/Hearings, 66 FR 31,719 (June 12, 2001) [hereinafter Meeting Security Guidelines]. All individuals... Atomic Safety and Licensing Board; Calvert Cliffs 3 Nuclear Project, LLC, and UniStar Nuclear Operating... Calvert Cliffs 3 Nuclear Project, L.L.C., and UniStar Nuclear Operating Services, L.L.C. (Applicants)...

  9. 78 FR 4467 - UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ... Register notice (FR) 76 FR 81994 (December 29, 2011). 2.0 Request/Action The regulations specified in 10... COMMISSION UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3, Exemption 1.0 Background UniStar Nuclear Energy (UNE), on behalf of Calvert Cliffs Nuclear Project, LLC...

  10. 77 FR 10784 - Calvert Cliffs Nuclear Power Plant, LLC; Notice of Withdrawal of Application for Amendment to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-23

    ... Nuclear Plant, Units 1 and 2, respectively, located in Calvert County, Maryland. The proposed amendment... in the Federal Register on April 19, 2011 (76 FR 21919). However, by letter dated January 27, 2012... Calvert Cliffs Nuclear Power Plant, LLC; Notice of Withdrawal of Application for Amendment to...

  11. 78 FR 4467 - UniStar Nuclear Energy, Combined License Application for Calvert Cliffs Power Plant, Unit 3...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-22

    ...52-016; NRC-2008-0250] UniStar Nuclear Energy, Combined License Application for Calvert...3, Exemption 1.0 Background UniStar Nuclear Energy (UNE), on behalf of Calvert Cliffs Nuclear Project, LLC and UniStar Nuclear...

  12. Disposal of chemical agents and munitions stored at Pine Bluff Arsenal, Pine Bluff, Arkansas

    SciTech Connect

    Ensminger, J.T.; Hillsman, E.L.; Johnson, R.D.; Morrisey, J.A.; Staub, W.P.; Boston, C.R.; Hunsaker, D.B.; Leibsch, E.; Rickert, L.W.; Tolbert, V.R.; Zimmerman, G.P.

    1991-09-01

    The Pine Bluff Arsenal (PBA) near Pine Bluff, Arkansas, is one of eight continental United States (CONUS) Army installations where lethal unitary chemical agents and munitions are stored and where destruction of agents and munitions is proposed under the Chemical Stockpile Disposal Program (CSDP). The chemical agent inventory at PBA consists of approximately 12%, by weight, of the total US stockpile. The destruction of the stockpile is necessary to eliminate the risk to the public from continued storage and to dispose of obsolete and leaking munitions. In 1988 the US Army issued a Final Programmatic Environmental Impact Statement (FPEIS) for the CSDP that identified on-site disposal of agents and munitions as the environmentally preferred alternative (i.e., the alternative with the least potential to cause significant adverse impacts). The purpose of this report is to examine the proposed implementation of on-site disposal at PBA in light of more recent and more detailed data than those on which the FPEIS is based. New population data were used to compute fatalities using the same computation methods and values for all other parameters as in the FPEIS. Results indicate that all alternatives are indistinguishable when the potential health impacts to the PBA community are considered. However, risks from on-site disposal are in all cases equal to or less than risks from other alternatives. Furthermore, no unique resources with the potential to prevent or delay implementation of on-site disposal at PBA have been identified.

  13. 76 FR 53426 - Moss Bluff Hub, LLC; Notice of Baseline Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ...ENERGY Federal Energy Regulatory Commission [Docket No. PR11-123-000] Moss Bluff Hub, LLC; Notice of Baseline Filing Take notice that on August 17, 2011, Moss Bluff Hub, LLC submitted a revised Statement of Operating Conditions,...

  14. Resonant Vibrations of Bluff Bodies Cause Multivortex Shedding and High Frequency Forces J. M. Dahl,* F. S. Hover, and M. S. Triantafyllou

    E-print Network

    Dong, Suchuan "Steven"

    Resonant Vibrations of Bluff Bodies Cause Multivortex Shedding and High Frequency Forces J. M. Dahl frequency, the lift (transverse) force contains a dominant fluctuating component with the vortex-shedding with half the vortex-shedding period. Vortex formation locks on to the frequency of cylinder vibration

  15. Gas Turbine Engine Staged Fuel Injection Using Adjacent Bluff Body and Swirler Fuel Injectors

    NASA Technical Reports Server (NTRS)

    Snyder, Timothy S. (Inventor)

    2015-01-01

    A fuel injection array for a gas turbine engine includes a plurality of bluff body injectors and a plurality of swirler injectors. A control operates the plurality of bluff body injectors and swirler injectors such that bluff body injectors are utilized without all of the swirler injectors at least at low power operation. The swirler injectors are utilized at higher power operation.

  16. Dynamics of perturbed exothermic bluff-body flow-fields

    NASA Astrophysics Data System (ADS)

    Shanbhogue, Santosh Janardhan

    This thesis describes research on acoustically excited bluff body flow-fields, motivated by the problem of combustion instabilities in devices utilizing these types of flame-holders. Vortices/convective-structures play a dominant role in perturbing the flame during these combustion instabilities. This thesis addresses a number of issues related to the origin, evolution and the interaction of these structures with the flame. The first part of this thesis reviews the fluid mechanics of non-reacting and reacting bluff body flows. The second part describes the spatio/temporal characteristics of bluff-body flames responding to excitation. The key processes controlling the flame response have been identified as (1) the anchoring of the flame at the bluff body, (2) the excitation of flame-front wrinkles by the oscillating velocity field and (3) flame propagation normal to itself at the local flame speed. The first two processes control the growth of the flame response and the last process controls the decay. The third part of this thesis describes the effect of acoustic excitation on the velocity field of reacting bluff body flows. Acoustic disturbances excite the Kelvin-Helmholtz (KH) instability of the reacting shear layer. This leads to a spatially decaying vorticity field downstream of the bluff body in the shear layers. The length over which the decay occurs was shown to scale with the length of the recirculation zone of the bluff body, i.e. the length over which the velocity profile transitions from shear layer to wake. The flame influences this decay process in two ways. Gas expansion across the flame reduces the extent of shear by reducing the magnitude of negative velocities within the recirculation zone. This combined with the higher product diffusivity reduces the length of the recirculation zone, thereby further augmenting the decay of the vorticity fluctuations. Lastly, these results also revealed the phase jitter - a cycle-to-cycle variation in the position of the rolled-up vortices. Close to the bluff-body, phase jitter is very low but increases monotonically in the downstream direction. This leads to significant differences between instantaneous and ensemble averaged flow fields and, in particular, the decay rate of the vorticity in the downstream direction.

  17. 75 FR 60147 - Calvert Cliffs Nuclear Power Plant, LLC; Independent Spent Fuel Storage Installation; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ... Calvert Cliffs Nuclear Power Plant, LLC; Independent Spent Fuel Storage Installation; Notice of Issuance... Nuclear Power Plant, LLC (CCNPP) submitted an application to NRC, in accordance with 10 CFR Part 72... published in the Federal Register on January 14, 2010 (75 FR 2163). Pursuant to 10 CFR 72.46(b)(2),...

  18. Overview of the Grand Junction Office from Bluff east of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overview of the Grand Junction Office from Bluff east of facility. Note Buildings #35. #33 and #31A in lower left of photograph. VIEW WEST - Department of Energy, Grand Junction Office, 2597 B3/4 Road, Grand Junction, Mesa County, CO

  19. 4. IRONWOOD BLUFFS BRIDGE MISSISSIPPI, ITAWAMBA CO. One mile W ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. IRONWOOD BLUFFS BRIDGE MISSISSIPPI, ITAWAMBA CO. One mile W of Ms. 25 on dirt road 2.5 mi. N of Bull Mtn. Cr. View from N, wide angle. Sarcone Photography, Columbus, Ms. September 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  20. 3. IRONWOOD BLUFFS BRIDGE MISSISSIPPI, ITAWAMBA CO. One mile W ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. IRONWOOD BLUFFS BRIDGE MISSISSIPPI, ITAWAMBA CO. One mile W of Ms. 25 on dirt road 2.5 mi. N of Bull Mtn. Cr. View from S side of E approach. Sarcone Photography, Columbus, Ms. September 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  1. 1. IRONWOOD BLUFFS BRIDGE Tombigbee R. MISSISSIPPI, ITAWAMBA CO. One ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. IRONWOOD BLUFFS BRIDGE Tombigbee R. MISSISSIPPI, ITAWAMBA CO. One mile W of Ms. 25 on dirt road 2.5 mi. N of Bull Mtn. Cr. Detail of upper panel point, showing components of members. Sarcone Photography, Columbus, Ms. September 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  2. 5. IRONWOOD BLUFFS BRIDGE MISSISSIPPI, ITAWAMBA CO. One mile W ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. IRONWOOD BLUFFS BRIDGE MISSISSIPPI, ITAWAMBA CO. One mile W of Ms. 25 on dirt road 2.5 mi. N of Bull Mtn. Cr. View of underside from NE shore, showing lower panel point, lateral bracing. Sarcone Photography, Columbus, Ms. September 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  3. 2. IRONWOOD BLUFFS BRIDGE MISSISSIPPI, ITAWAMBA CO. One mile W ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. IRONWOOD BLUFFS BRIDGE MISSISSIPPI, ITAWAMBA CO. One mile W of Ms. 25 on dirt road 2.5 mi. N of Bull Mtn. Cr. Oblique view of N truss from E end. Sarcone Photography, Columbus, Ms. September 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  4. Determination of Shoreline Erosion Rates of Double Bluff Suzanne Cruchon

    E-print Network

    Winglee, Robert M.

    Determination of Shoreline Erosion Rates of Double Bluff Suzanne Cruchon Advisor: Dr. Terry Swanson Dept. of Earth and Space Science, University of Washington. Introduction The Puget Sound and southern bedrock shorelines occur more frequently in the northerly inland waters. Shoreline erosion rates are much

  5. Bluff Body Fluid Interactions Modelling for Micro Energy Harvesting Application

    NASA Astrophysics Data System (ADS)

    Bhuyan, M. S.; Majlis, B. Y.; Othman, M.; Ali, Sawal H. Md; Kalaivani, C.; Islam, S.

    2013-04-01

    In this paper, we have presented a MEMS-based piezoelectric fluid-flow based micro energy harvester. The design and modelling of the energy harvester structure was based on a piezoelectric cantilever affixed to a bluff-body. In a cross fluid flow, pressure in the flow channel, in the wake of the bluff body, fluctuates with the same frequency as the pressure variation caused by the Kármán Vortex Street. This fluctuation of pressure in the flow channel causes the piezoelectric cantilever, trailing the bluff-body, to vibrate in a direction normal to the fluid flow direction. COMSOL finite element analysis software are used for the evaluation of various mechanical analysis of the micro energy harvester structure like, physical the Stress and Strain state in the cantilever structures, Eigen frequency Analysis, Transient analysis to demonstrate the feasibility of the design. Detailed steps of modelling and simulation results of the uniform cantilever were explained. The results confirm the probability of the fluid flow based MEMS energy harvester.

  6. 78 FR 33121 - Staff Requirements-SECY-12-0168-Calvert Cliffs 3 Nuclear Project, LLC & UniStar Nuclear Operating...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-03

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Staff Requirements--SECY-12-0168--Calvert Cliffs 3 Nuclear Project, LLC & UniStar Nuclear.... On March 11, 2013, in SRM-12-0168, ``Calvert Cliffs 3 Nuclear Project, LLC & UniStar...

  7. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207...REGULATIONS § 207.169 Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and...

  8. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207...REGULATIONS § 207.169 Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and...

  9. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207...REGULATIONS § 207.169 Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and...

  10. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207...REGULATIONS § 207.169 Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and...

  11. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207...REGULATIONS § 207.169 Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and...

  12. RESEARCH ARTICLE Drag and lift reduction of a 3D bluff-body using active vortex

    E-print Network

    Wesfreid, José Eduardo

    RESEARCH ARTICLE Drag and lift reduction of a 3D bluff-body using active vortex generators Jean forces (drag and lift) induced on the bluff- body is investigated. The high sensitivity to many geo demonstrated. The maximum drag reduction is -12%, while the maximum global lift reduc- tion can reach more than

  13. Drag reduction of a bluff body using adaptive control methods Jean-Franois Beaudoina

    E-print Network

    Wesfreid, José Eduardo

    Drag reduction of a bluff body using adaptive control methods Jean-François Beaudoina Department 2006 A classical actuator is used to control the drag exerted on a bluff body at large Reynolds number a rotating cylinder at the edge. The slow fluctuations of the total drag are directly measured by means

  14. 75 FR 33799 - Moss Bluff Hub, LLC; Notice of Baseline Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-15

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Moss Bluff Hub, LLC; Notice of Baseline Filing June 8, 2010. Take notice that on June 1, 2010, Moss Bluff Hub, LLC submitted a baseline filing of its Statement of General...

  15. 76 FR 53426 - Moss Bluff Hub, LLC; Notice of Baseline Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-26

    ... From the Federal Register Online via the Government Printing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Moss Bluff Hub, LLC; Notice of Baseline Filing Take notice that on August 17, 2011, Moss Bluff Hub, LLC submitted a revised Statement of Operating Conditions, that governs...

  16. 75 FR 33799 - Moss Bluff Hub, LLC; Notice of Baseline Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-15

    ...ENERGY Federal Energy Regulatory Commission [Docket No. PR10-28-000] Moss Bluff Hub, LLC; Notice of Baseline Filing June 8, 2010. Take notice that on June 1, 2010, Moss Bluff Hub, LLC submitted a baseline filing of its Statement of...

  17. Coherent structure in flow over a slitted bluff body

    NASA Astrophysics Data System (ADS)

    Du, Yiqing; Qian, Renzhang; Peng, Shiwen

    2006-06-01

    The focus of the present investigation is resolution of the coherent structure in the near wake behind a slitted bluff body. The bluff body is two-dimensional with gap ratio from 0.12 to 0.48. The evolution of the structure was numerically investigated using the renormalization group (RNG) k- ? model at Reynolds number of 470,000. Two types of coherent structure are identified: At low gap ratio 0.12, the structure is characterized by a flip-flopping gap flow; at high ratio 0.22-0.48, the gap flow deflects to one side with an asymmetrical wake. The coherent structure is divided by the gap flow into two zones called the primary recirculation zone and the secondary recirculation zone. The coherent structure is intimately related to the gap ratio, and the structure of small gap ratio is different from that of large gap ratio because the interaction between two zones relates to the gap ratio. To explain the vortex shedding, a mechanism that single vortex of large size suddenly immerses between two shear layers was proposed. Experimental results using point-to-point method and particle-image velocimetry (PIV) measurements in a close wind tunnel were also carried out to confirm the observation from the numerical study. The evidence shows that the numerical results are of good agreement with the experiments. The comparison between the RNG k- ? model and the large eddy simulation also indicates that the RNG k- ? model is adequate in computing the bluff body flow.

  18. Secondary sulfate minerals from Alum Cave Bluff: Microscopy and microanalysis

    SciTech Connect

    Lauf, R.J.

    1997-07-01

    Microcrystals of secondary sulfate minerals from Alum Cave Bluff, Great Smoky Mountains National Park, were examined by scanning electron microscopy and identified by X-ray fluorescence (XRF) in the SEM. Among the samples the author discovered three new rare-earth sulfates: coskrenite-(Ce), levinsonite-(Y), and zugshunstite-(Ce). Other minerals illustrated in this report include sulfur, tschermigite, gypsum, epsomite, melanterite, halotrichite, apjohnite, jarosite, slavikite, magnesiocopiapite, and diadochite. Additional specimens whose identification is more tentative include pickeringite, aluminite, basaluminite, and botryogen. Alum Cave is a ``Dana locality`` for apjohnite and potash alum, and is the first documented North American occurrence of slavikite.

  19. Fighting Online Click-Fraud Using Bluff Ads

    E-print Network

    Haddadi, Hamed

    2010-01-01

    Online advertising is currently the greatest source of revenue for many Internet giants. The increased number of specialized websites and modern profiling techniques, have all contributed to an explosion of the income of ad brokers from online advertising. The single biggest threat to this growth, is however, click-fraud. Trained botnets and even individuals are hired by click-fraud specialists in order to maximize the revenue of certain users from the ads they publish on their websites, or to launch an attack between competing businesses. In this note we wish to raise the awareness of the networking research community on potential research areas within this emerging field. As an example strategy, we present Bluff ads; a class of ads that join forces in order to increase the effort level for click-fraud spammers. Bluff ads are either targeted ads, with irrelevant display text, or highly relevant display text, with irrelevant targeting information. They act as a litmus test for the legitimacy of the individual...

  20. Coastal erosion: Processes, timing and magnitudes at the bluff toe

    USGS Publications Warehouse

    Carter, C.H.; Guy, D.E., Jr.

    1988-01-01

    Five Lake Erie bluffs (one interlaminated clay and silt, three clay-rich diamicts and one shale) were surveyed at about 2-week intervals and after wind storms for up to 5 years. Erosion of the bluff toes along this low-energy coast occurred during northeast wind storms, which produced surges of up to 1 m and surf-zone waves of up to 1.2 m. Wave impact and/or uprush caused quarrying, which removed most of the toe material, and abrasion. There were from 1 to 23 erosion events/sites, with maximum magnitudes of erosion ranging from 12 to 55 cm/event. Timing and magnitude were linked to erodibility, maximum water level, storm surge, storm duration and beach width. A threshold maximum water level and a threshold surge were necessary for erosion. At these thresholds, the beach was submerged and wave energy was directly expended on the toe. Erosion did not take place when there was shorefast ice or when debris slopes shielded the toe from waves. The originally cohesive toe materials are easily eroded when they weather to an essentially noncohesive state. Wave erosion is the crucial erosion process; removal of material from the toe prevents the development of a stable slope. ?? 1988.

  1. Blowoff dynamics of bluff body stabilized turbulent premixed flames

    SciTech Connect

    Chaudhuri, Swetaprovo; Kostka, Stanislav; Renfro, Michael W.; Cetegen, Baki M.

    2010-04-15

    This article concerns the flame dynamics of a bluff body stabilized turbulent premixed flame as it approaches lean blowoff. Time resolved chemiluminescence imaging along with simultaneous particle image velocimetry and OH planar laser-induced fluorescence were utilized in an axisymmetric bluff body stabilized, propane-air flame to determine the sequence of events leading to blowoff and provide a quantitative analysis of the experimental results. It was found that as lean blowoff is approached by reduction of equivalence ratio, flame speed decreases and the flame shape progressively changes from a conical to a columnar shape. For a stably burning conical flame away from blowoff, the flame front envelopes the shear layer vortices. Near blowoff, the columnar flame front and shear layer vortices overlap to induce high local stretch rates that exceed the extinction stretch rates instantaneously and in the mean, resulting in local flame extinction along the shear layers. Following shear layer extinction, fresh reactants can pass through the shear layers to react within the recirculation zone with all other parts of the flame extinguished. This flame kernel within the recirculation zone may survive for a few milliseconds and can reignite the shear layers such that the entire flame is reestablished for a short period. This extinction and reignition event can happen several times before final blowoff which occurs when the flame kernel fails to reignite the shear layers and ultimately leads to total flame extinguishment. (author)

  2. Combustion heat release effects on asymmetric vortex shedding from bluff bodies

    NASA Astrophysics Data System (ADS)

    Cross, Caleb Nathaniel

    2011-07-01

    This thesis describes an investigation of oscillatory combustion processes due to vortex shedding from bluff body flame holders. The primary objective of this study was to elucidate the influence of combustion process heat release upon the Benard-von Karman (BVK) instability in reacting bluff body wakes. For this purpose, spatial and temporal heat release distributions in bluff body-stabilized combustion of liquid Jet-A fuel with high-temperature, vitiated air were characterized over a wide range of operating conditions. Two methods of fuel injection were investigated. In the first method, referred to as close-coupled fuel injection, the fuel was supplied via discrete liquid jets injected perpendicular to the cross-flowing air stream just upstream of the bluff body trailing edge, thereby limiting fuel and air mixing prior to burning. The fuel was introduced well upstream (˜0.5 m) of the bluff body in the second fuel injection mode, resulting in a well-evaporated and mixed reactants stream. The resulting BVK heat release dynamics were compared between these fuel injection modes in order to investigate their dependence upon the spatial distributions of fuel-air ratio and heat release in the reacting wake. When close-coupled fuel injection was used, the BVK heat release dynamics increased in amplitude with increasing global equivalence ratio, reaching a maximum just before globally rich blow out of the combustion process occurred. This was due to a decrease in fuel entrainment into the near-wake as the fuel spray penetrated further into the cross-flow, which reduced the local heat release and equivalence ratio (indicated by CH* and C2*/CH* chemiluminescence, respectively). As a result, the density gradient across the near-wake reaction zone decreased, resulting in less damping of vorticity due to dilatation. In addition, unburned reactants were entrained into the recirculation zone due to the injection of discrete liquid fuel jets in close proximity to the wake. This reduced the temperature of the recirculating gases further, resulting in large (i.e., near-unity) products-to-reactants density ratios in the near-wake. When the fuel was introduced upstream of the bluff body, the BVK heat release dynamics significantly decreased in amplitude. In this case the fuel was, in all likelihood, fully evaporated and well-mixed with the air prior to burning, resulting in greater amounts of fuel entrainment and subsequent heat release in the near-wake than in the close-coupled fuel injection case. In addition, the heat release was distributed more uniformly across the combustor span, which led to stronger density gradients across the near-wake reaction zone than in close-coupled-fuelled flames due to a lack of reactants entrainment into the recirculation zone. This enhanced the damping of vorticity due to dilatation, which inhibited the formation and shedding of the large-scale, coherent vortices. When the local density gradient was large enough, the BVK instability was completely suppressed. A parallel, linear stability analysis was performed in order to further understand the influence of the near-wake combustion process heat release upon the wake instability characteristics. The results of this analysis indicate that the products-to-reactants density and velocity ratios in the near-wake are the primary parameters controlling the onset of local absolute instability (a necessary condition for the global, BVK instability) in reacting wakes. Upon comparing these results to the measured data, absolute instability was predicted for all operating conditions in which relatively high-amplitude BVK heat release dynamics were observed. This was the case for close-coupled fuel injection at all global equivalence ratios, as well as upstream fuel injection at lean equivalence ratios, due to the low temperature rise across the reacting shear layers in these cases. Only upstream fuel injection at near stoichiometric fuel-air ratios resulted in local products-to-reactants density ratios low enough to suppress absolute instability and, thus, BVK vort

  3. Disposal of chemical agents and munitions stored at Pine Bluff Arsenal, Pine Bluff, Arkansas. Final phase 1, Environmental report

    SciTech Connect

    Ensminger, J.T.; Hillsman, E.L.; Johnson, R.D.; Morrisey, J.A.; Staub, W.P.; Boston, C.R.; Hunsaker, D.B.; Leibsch, E.; Rickert, L.W.; Tolbert, V.R.; Zimmerman, G.P.

    1991-09-01

    The Pine Bluff Arsenal (PBA) near Pine Bluff, Arkansas, is one of eight continental United States (CONUS) Army installations where lethal unitary chemical agents and munitions are stored and where destruction of agents and munitions is proposed under the Chemical Stockpile Disposal Program (CSDP). The chemical agent inventory at PBA consists of approximately 12%, by weight, of the total US stockpile. The destruction of the stockpile is necessary to eliminate the risk to the public from continued storage and to dispose of obsolete and leaking munitions. In 1988 the US Army issued a Final Programmatic Environmental Impact Statement (FPEIS) for the CSDP that identified on-site disposal of agents and munitions as the environmentally preferred alternative (i.e., the alternative with the least potential to cause significant adverse impacts). The purpose of this report is to examine the proposed implementation of on-site disposal at PBA in light of more recent and more detailed data than those on which the FPEIS is based. New population data were used to compute fatalities using the same computation methods and values for all other parameters as in the FPEIS. Results indicate that all alternatives are indistinguishable when the potential health impacts to the PBA community are considered. However, risks from on-site disposal are in all cases equal to or less than risks from other alternatives. Furthermore, no unique resources with the potential to prevent or delay implementation of on-site disposal at PBA have been identified.

  4. Thermal Modeling of NUHOMS HSM-15 and HSM-1 Storage Modules at Calvert Cliffs Nuclear Power Station ISFSI

    SciTech Connect

    Suffield, Sarah R.; Fort, James A.; Adkins, Harold E.; Cuta, Judith M.; Collins, Brian A.; Siciliano, Edward R.

    2012-10-01

    As part of the Used Fuel Disposition Campaign of the Department of Energy (DOE), visual inspections and temperature measurements were performed on two storage modules in the Calvert Cliffs Nuclear Power Station’s Independent Spent Fuel Storage Installation (ISFSI). Detailed thermal models models were developed to obtain realistic temperature predictions for actual storage systems, in contrast to conservative and bounding design basis calculations.

  5. 76 FR 81994 - UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-29

    ... From the Federal Register Online via the Government Printing Office NUCLEAR REGULATORY COMMISSION UniStar Nuclear Energy; Combined License Application for Calvert Cliffs Nuclear Power Plant, Unit 3; Exemption 1.0 Background: UniStar Nuclear Energy (UNE) submitted to the U.S. Nuclear Regulatory...

  6. A study of a bluff-body combustor using laser sheet lighting

    NASA Astrophysics Data System (ADS)

    Roquemore, W. M.; Tankin, R. S.; Chiu, H. H.; Lottes, S. A.

    1986-07-01

    Laser sheet lighting is used to study reacting flows with and without heat release in an axisymmetric, unducted and vertically mounted bluff-body combustor. The fuel, which is seeded with titanium tetrachloride vapor, is ejected from a jet located in the center of the bluff-body. The TiCl4 in the dry fuel reacts spontaneously with the water in the annulus air to form titanium dioxide particles. High speed movies and visual observations of vertically and horizontally located sheets of laser light provided remarkably detailed visualization (via Mie scattering) of the vortex dynamics in the near-wake region of the bluff-body.

  7. The Role of Bluff-Body Roughness Elements on Turbulent Evaporative Fluxes from Porous Surfaces: Momentum and Energy Partitioning

    NASA Astrophysics Data System (ADS)

    Or, D.; Haghighi, E.; Lagüela, S.; Aminzadeh, M.

    2014-12-01

    Bluff body obstacles in turbulent flows are common in many natural and engineering applications (from desert pavement and boulders to shrubs). The deceivingly simple geometry of a surface-mounted obstacle in a boundary layer induces a complex and unsteady flow field that affect the surface drag partitioning and transport of scalars form surrounding evaporating surfaces. The readily observable spatio-temporal distribution of localized evaporation rates from infrared measured thermal signatures provide the impetus for a simple zonation scheme that enables estimates of evaporative fluxes around an obstacle. Results from evaporation experiments from sand surfaces with isolated cylindrical elements (bluff bodies) subjected to constant turbulent airflows were in good agreement with model predictions for localized exchange rates. The results show consistent enhancement of evaporating fluxes relative to a smooth surface to formation of vortices that induce thinner boundary layers. We also considered effects of obstacles on (solar) short wave radiation and energy partitioning over surfaces and successfully represented zonation of surface exchange due to momentum (drag partitioning) and variable surface energy balance on localized evaporation. A scheme for upscaling the results to evaporation from surfaces with multiple obstacles will be presented.

  8. 78 FR 20942 - Niobrara Confluence and Ponca Bluffs Conservation Areas, NE and SD; Draft Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ...the Great Plains to the Eastern deciduous forest. It drains one-sixth of the...also experience scenic bluffs, forests, grasslands, and traditional...natural floodplain and upland forest communities, pastureland,...

  9. Pressurized thermal shock evaluation of the Calvert Cliffs Unit 1 Nuclear Power Plant

    SciTech Connect

    Abbott, L

    1985-09-01

    An evaluation of the risk to the Calvert Cliffs Unit 1 nuclear power plant due to pressurized thermal shock (PTS) has been completed by Oak Ridge National Laboratory (ORNL) with the assistance of several other organizations. This evaluation was part of a Nuclear Regulatory Commission program designed to study the PTS risk to three nuclear plants, the other two plants being Oconee Unit 1 and H.B. Robinson Unit 2. The specific objectives of the program were to (1) provide a best estimate of the frequency of a through-the-wall crack in the pressure vessel at each of the three plants, together with the uncertainty in the estimated frequency and its sensitivity to the variables used in the evaluation; (2) determine the dominant overcooling sequences contributing to the estimated frequency and the associated failures in the plant systems or in operator actions; and (3) evaluate the effectiveness of potential corrective measures.

  10. Laboratory measurements of upwelled radiance and reflectance spectra of Calvert, Ball, Jordan, and Feldspar soil sediments

    NASA Technical Reports Server (NTRS)

    Whitlock, C. H.; Usry, J. W.; Witte, W. G.; Gurganus, E. A.

    1977-01-01

    An effort to investigate the potential of remote sensing for monitoring nonpoint source pollution was conducted. Spectral reflectance characteristics for four types of soil sediments were measured for mixture concentrations between 4 and 173 ppm. For measurements at a spectral resolution of 32 mm, the spectral reflectances of Calvert, Ball, Jordan, and Feldspar soil sediments were distinctly different over the wavelength range from 400 to 980 nm at each concentration tested. At high concentrations, spectral differences between the various sediments could be detected by measurements with a spectral resolution of 160 nm. At a low concentration, only small differences were observed between the various sediments when measurements were made with 160 nm spectral resolution. Radiance levels generally varied in a nonlinear manner with sediment concentration; linearity occurred in special cases, depending on sediment type, concentration range, and wavelength.

  11. Thermal Modeling Studies for Active Storage Modules in the Calvert Cliffs ISFSI

    SciTech Connect

    Adkins, Harold E.; Fort, James A.; Suffield, Sarah R.; Cuta, Judith M.; Collins, Brian A.

    2013-06-14

    Temperature measurements obtained for two storage modules in the Calvert Cliffs Nuclear Power Station’s Independent Spent Fuel Storage Installation (ISFSI) as part of the Used Fuel Disposition Campaign of the Department of Energy (DOE) were used to perform validation and sensitivity studies on detailed computational fluid dynamics (CFD) models of the concrete storage modules, including the dry storage canister within the modules. The storage modules in the Calvert Cliffs Nuclear Power Station’s ISFSI are a site-specific version of the standard NUHOMS® HSM. The two modules inspected each contained a 24P DSC loaded with 24 CE 14x14 spent fuel assemblies. The thermal analysis was performed using the STAR-CCM+ package, and the models developed for the specific ISFSI modules yielded temperature predictions in actual storage conditions for the concrete structure, the DSC and its contents, including preliminary estimates of fuel cladding temperatures for the used nuclear fuel. The results of this work demonstrate that existing CFD modeling tools can be used to obtain reasonable and accurate detailed representations of spent fuel storage systems with realistic decay heat loadings when the model omits specific conservatisms and bounding assumptions normally used in design-basis and safety-basis calculations. This paper presents sensitivity studies on modeling detail (for the storage module and the DSC), boundary conditions, and decay heat load, to evaluate the effect of the modeling approach on predicted temperatures and temperature distributions. Because nearly all degradation mechanisms for materials and structures comprising dry storage and transportation systems are dependent on temperature, accurate characterization of local temperatures and temperature gradients that the various components of these systems will experience over the entire storage period has been identified as a primary requirement for evaluation of very long term storage of used nuclear fuel.

  12. Apparatus And Method For Reducing Drag Of A Bluff Body In Ground Effect Using Counter-Rotating Vortex Pairs

    DOEpatents

    Ortega, Jason M. (Pacifica, CA); Salari, Kambiz (Livermore, CA)

    2005-08-09

    An aerodynamic base drag reduction apparatus and method for bluff bodies, such as tractor-trailer trucks, utilizing a pair of lift surfaces extending to lift surface tips and located alongside the bluff body such as on opposing left and right side surfaces. In a flowstream substantially parallel to the longitudinal centerline of the bluff body, the pair of lift surfaces generate a pair of counter-rotating trailing vortices which confluence together in the wake of the bluff body in a direction orthogonal to the flowstream. The confluence draws or otherwise turns the flowstream, such as the flowstream passing over a top surface of the bluff body, in and around behind a trailing end of the bluff body to raise the pressure on a base surface at the trailing end and thereby reduce the aerodynamic base drag.

  13. Apparatus And Method For Reducing Drag Of A Bluff Body In Ground Effect Using Counter-Rotating Vortex Pairs

    DOEpatents

    Ortega, Jason M. (Pacifica, CA); Sabari, Kambiz (Livermore, CA)

    2005-12-27

    An aerodynamic base drag reduction apparatus and method for bluff bodies, such as tractor-trailer trucks, utilizing a pair of lift surfaces extending to lift surface tips and located alongside the bluff body such as on opposing left and right side surfaces. In a flowstream substantially parallel to the longitudinal centerline of the bluff body, the pair of lift surfaces generate a pair of counter-rotating trailing vortices which confluence together in the wake of the bluff body in a direction orthogonal to the flowstream. The confluence draws or otherwise turns the flowstream, such as the flowstream passing over a top surface of the bluff body, in and around behind a trailing end of the bluff body to raise the pressure on a base surface at the trailing end and thereby reduce the aerodynamic base drag.

  14. Late Wisconsinan sub-glacial clastic intrusive sheets along Lake Erie bluffs, at Bradtville, Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Dreimanis, Aleksis; Rappol, Martin

    1997-07-01

    Numerous clastic intrusive sheets, a few decimetres to more than 16 m long, 1-120 cm thick, and extending one to more than 25 m laterally, occur along a 350 m long section of the late Wisconsinan Catfish Creek Drift in the Lake Erie bluffs at Bradtville, southwestern Ontario. Most of them are downglacier-dipping dikes, the largest one terminating in the underlying middle Wisconsinan Tyrconnell Formation. Most dikes strike NNE-SSW, at right angles to the local direction of glacier movement during the deposition of Catfish Creek Drift. The tops of some of them are truncated or displaced downglacier by shearing. The main concentration of clastic intrusive sheets is on the upglacier side of a glaciotectonically folded anticline of Tyrconnell Formation clays and silts underlying the Catfish Creek Drift. The host sediments are Catfish Creek till, gravel, sand and silt, and Tyrconnell Formation silt and clay. Most intrusive sheets, particularly the small to medium ones, consist of massive to crudely laminated sand and silt, intruded from below by a dewatering process. The largest dike reflects in its composition mainly the adjoining or higher-lying host-sediment materials, and its main part was formed by downward infilling, or by gravity flows into an open fracture. The large dike is flanked by small laminated silty sand sheets and several small apophyses, some of them injected downward and sideways, others upward by dewatering. The clastic intrusive sheets were formed under a moving glacier, the Erie lobe, probably both at the beginning and towards the end of the deposition of Catfish Creek till. Their location and position was predetermined by glaciotectonically induced listric planar structures and zones of weakness, mainly tension fractures, that strike transverse to glacier movement and dip downglacier and also by confinement of pore-water in a permeable sediment wedge between the less pervious Tyrconnell Formation and massive Catfish Creek basal till.

  15. Failure modes of thawing permafrost bluffs on the Chukchi Sea coast, Alaska

    NASA Astrophysics Data System (ADS)

    Collins, B. D.; Erikson, L. H.; Reiss, T.

    2009-12-01

    Increasing Arctic temperatures from global climate change are well documented, however an understanding of their influences on specific geomorphic processes affecting arctic coastal bluff erosion are much less well understood. Coastal bluffs in natural settings typically erode through a suite of geomorphic processes including both marine (e.g. wave action) and terrestrial (e.g. groundwater seepage) forces. In arctic settings, thermal influences which affect both terrestrial and marine ice content also govern these processes and create additional inputs to instability and erosion. Here, we investigate the failure modes of coastal bluffs along a 10 km length of the Chukchi Sea in northwestern Alaska with the goal of identifying the predominant processes and their topographic signatures. We use high-resolution terrestrial lidar surveying, georeferenced simultaneously via geodetic-grade GPS measurements, to analyze cross-sections of the bluffs and compare these to observations of the predominant failure modes identified during recent field work. An effort is made to link the processes directly to the mapped stratigraphy of the bluffs. Our observations identify at least three different failure modes: (1) downward-driven spreads associated with thaw-slump activity in originally ice-bonded clay and sand, (2) topples of ice-wedge bounded, cantilevered ice-bonded peat and clay tundra blocks, and (3) retrogressive, steeply inclined translational ice-thawed sand landslides. All three failure modes are associated with warming air temperatures while the last two modes also appear to be initiated by thermal niching and/or wave action at the base of the bluff. Identification of the predominant failure modes along this coast will assist with further investigations aimed at predicting trends of both short- and long-term coastal erosion and their impact on local communities and wildlife habitats. Terrestrial lidar data collection of Arctic coastal bluff failure modes along the Chukchi Sea, Alaska

  16. Driftwood dropstones in mid-Miocene shallow marine strata (Calvert Cliffs, Maryland Coastal Plain): An erratic lithic pebble des not necessarily a cold paleoclimate make

    NASA Astrophysics Data System (ADS)

    Vogt, P. R.; Parrish, M.

    2009-12-01

    Erratic lithic pebbles recovered from marine sediments are routinely identified as Ice-Rafted Debris (IRD), transported by icebergs, sea ice, or river ice discharged into the sea. We suggest this is not always the transport mechanism--especially when other paleoclimatologic proxies indicate relatively warm climates and extensive forests in the pebble provenance regions. Rivers could transport significant amounts of pebbbles as driftwood dropstones, trapped in the roots of trees and later uprooted in floods and carried out to sea. To illustrate a likely example of Tree-Rafted Detritus (TRD), we analyzed a collection of lithic erratics collected from three beds in eroding (5-10 cm/a) mid-Miocene (Serravalian)shallow marine deposits (upper Calvert Formation,Chesapeake Bay, southern Maryland), which predate the ca. 13.9 Ma global cooling and expansion of the East Antarctic Ice Sheet. The ca. 220 specimens (1-10 cm in diameter) are extremely variable in lithology and degree of roundness. The great majority are evidently of Piedmont provenance and were probably rafted ca. 120 km to the collection site from the paleo-mouth of the Susquehanna River, floated out to sea and carried south by the Miocene Coastal Current. River ice can probably be ruled out as the transport mechanism, given the prevailing warm temperate to subtropical climates. Common carbonized wood fragments (typically 2 x 10 cm in outcrop dimensions) in the same strata containing the erratics support driftwood transport. The lithic erratics may serve as independent tracers for terrestrial vertebrate fossils, transported into the Calvert Sea (Atlantic Ocean) by the 'float and bloat' mechanism.(Allowance has to be made for ca. 20 m/Ma post-middle Miocene source region denudation). However,only 3% of the clasts (mostly quartz diorite gneiss)could be readily related to a specific outcrop--the Port Deposit Gneiss near the modern mouth of the Susquehanna River. We suggest that driftwood transport be considered as a possibly significant alternative source of lithic erratics found in e.g. Middle Eocene Arctic Basin sediments--especially given that this basin was largely enclosed and fed by large rivers draining vast forests.

  17. White Bluffs Pickling Acid Cribs expedited response action proposal

    SciTech Connect

    Not Available

    1993-07-01

    The US Environmental Protection Agency (EPA) and Washington State Department of Ecology (Ecology) recommended in a letter dated March 4, 1992 (Attachment 1) that the US Department of Energy (DOE) prepare an expedited response action (ERA) for the White Bluffs Pickling Acid Cribs Site. The lead regulatory agency for this ERA is the EPA, with Ecology providing support. The goal of this ERA is to reduce the potential of any residual contaminant migration from the cribs to the soil column and groundwater. The cribs are the only waste site within the 100-IU-5 operable unit. Since the operable unit is surrounded by other waste units, tracing the potential groundwater contamination from the 100-IU-5 operable unit for this ERA would not be effective. Groundwater will be investigated with the 100-IU-2 operable unit. This ERA proposal presents the characterization data from the site investigations conducted in November of 1992. This information is evaluated to present the best method for reducing potential of contaminant migration from the disposal unit, ensuring both protection of human health and the environment. The ERA proposal will undergo a public review. EPA and Ecology will issue an Action Agreement Memorandum after comment resolution. This Action Memorandum may authorize implementation of the ERA proposal`s recommended alternative. The ERA may also provide a No Further Action Interim Record of Decision (IROD) of the 100-IU-5 operable unit.

  18. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207.169 Section 207.169 Navigation... REGULATIONS § 207.169 Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration,...

  19. Late Paleocene paleoenvironmental gradients in Wilcox Group strata, Big Brown Mine, Texas 

    E-print Network

    Klein, Jennifer Marie

    2000-01-01

    as primarily fluvial-deltaic in origin; however, since the 1980s, much evidence for tidal control on the deposition of the upper Wilcox (Calvert Bluff Formation) has been compiled. New data from the examination of sediments and fossils contained in the upper...

  20. Alteration of volcaniclastic deposits at Minna Bluff: Geochemical insights on mineralizing environment and climate during the Late Miocene in Antarctica

    NASA Astrophysics Data System (ADS)

    Antibus, Joanne V.; Panter, Kurt S.; Wilch, Thomas I.; Dunbar, Nelia; McIntosh, William; Tripati, Aradhna; Bindeman, Ilya; Blusztajn, Jerzy

    2014-08-01

    minerals in volcaniclastic deposits at Minna Bluff, a 45 km long peninsula in the Ross Sea, are used to infer processes of alteration and environmental conditions in the Late Miocene. Glassy volcaniclastic deposits are altered and contain phillipsite and chabazite, low to high-Mg carbonates, chalcedony, and clay. The ?18O of carbonates and chalcedony is variable, ranging from -0.50 to 21.53‰ and 0.68 to 10.37‰, respectively, and ?D for chalcedony is light (-187.8 to -220.6‰), corresponding to Antarctic meteoric water. A mean carbonate 87Sr/86Sr ratio of 0.70327 ± 0.0009 (1?, n = 12) is comparable to lava and suggests freshwater, as opposed to seawater, caused the alteration. Minerals were precipitated at elevated temperatures (91 and 104°C) based on quartz-calcite equilibrium, carbonate 13C-18C thermometry (?47 derived temperature = 5° to 43°C) and stability of zeolites in geothermal systems (>10 to ˜100°C). The alteration was a result of isolated, ephemeral events involving the exchange between heated meteoric water and glass during or soon after the formation of each deposit. Near-surface evaporative distillation can explain 18O-enriched compositions for some Mg-rich carbonates and chalcedony. The ?18Owater calculated for carbonates (-15.8 to -22.9‰) reveals a broad change, becoming heavier between ˜12 and ˜7 Ma, consistent with a warming climate. These findings are independently corroborated by the interpretation of Late Miocene sedimentary sequences recovered from nearby sediment cores. However, in contrast to a cold-based thermal regime proposed for ice flow at core sites, wet-based conditions prevailed at Minna Bluff; a likely consequence of high heat flow associated with an active magma system.

  1. National Assessment of Historical Shoreline Change: A Pilot Study of Historical Coastal Bluff Retreat in the Great Lakes, Erie, Pennsylvania

    USGS Publications Warehouse

    Hapke, Cheryl J.; Malone, Shamus; Kratzmann, Meredith

    2009-01-01

    Coastal bluff retreat is a chronic problem along many high-relief coastlines in the United States. As coastal populations continue to grow and community infrastructures are threatened by erosion, there is increased demand for accurate information regard-ing trends and rates of bluff retreat. There is also a need for a comprehensive analysis that is consistent from one coastal region to another. To address these national needs, the U.S. Geological Survey (USGS), as part of the National Assessment of Coastal Change Hazards Project, conducted a pilot study of bluff retreat along the Lake Erie, Pa., coastline to assess the feasibility of undertaking a larger, multi-state analysis in the Great Lakes region. This report provides an overview of the pilot-study location and bluff geomorphology, the data sources and methodology, results of the analysis, and a discussion of the feasibility of undertaking a similar analysis along eroding bluffs in other Great Lakes states. This pilot study is part of an ongoing effort by the USGS to provide a comprehensive analysis of historical shoreline change and cliff and bluff retreat along open-ocean coastlines of the conterminous United States and parts of Hawaii, Alaska, and the Great Lakes. One purpose of the work is to develop standard, repeatable methods for mapping and analyzing coastal change so that systematic and consistent periodic updates of coastal erosion can be made nationally. Bluff-retreat evaluations are conducted by comparing the location of a historical bluff edge digitized from aerial photographs with those of recent bluff edges interpreted from both aerial photographs and lidar topographic surveys. The historical bluff edge is from 1938, whereas the more recent bluff edges are from 1998 and 2006 lidar data. Long-term (68-year) rates of retreat are calculated using the available bluff-edge data. The rates of retreat presented in this report represent conditions from the 1930s to 1998/2006, and are not intended for predicting future bluff-edge positions or rates of retreat. The report presents bluff-retreat rates for 32 km of a 60-km stretch along the Lake Erie, Pa., coastline. Data are discontinuous due to gaps in source data and lack of continuous bluffs. The average rate of coastal bluff retreat for the Lake Erie, Pa., bluffs was -0.3 +- 0.1 m/yr (retreat rates are presented as negative numbers in this report), based on rates averaged from 1,595 individual transects. Retreat rates generally were lowest where bedrock outcrops are exposed as the basal unit in the bluff. The highest rates are associated with anthropogenic activities, including jetties that trap littoral sediment, depleting a source of material for the natural replenishment of protective beaches downcoast, and extensive irrigation of farmlands on the tops of the bluffs, which can destabilize bluffs by enhancing ground-water outflow.

  2. Twin solution calorimeter determines heats of formation of alloys at high temperatures

    NASA Technical Reports Server (NTRS)

    Darby, J. B., Jr.; Kleb, R.; Kleppa, O. J.

    1968-01-01

    Calvert-type, twin liquid metal solution calorimeter determines the heats of formation of transition metal alloys at high temperatures. The twin differential calorimeter measures the small heat effects generated over extended periods of time, has maximum operating temperature of 1073 degrees K and an automatic data recording system.

  3. Elimination of Vortex Streets in Bluff-Body Flows S. Dong,1,* G. S. Triantafyllou,2

    E-print Network

    Dong, Suchuan "Steven"

    technique for suppressing the vortex-induced vibrations of bluff bodies by eliminating the von Ka street could reduce such vortex-induced vibrations (VIV) and the wake turbulence, with a direct impact in suppressing vortex- induced vibrations. First, they may be effective only for stationary cylinders (not

  4. CONTROL AND SUPPRESSION OF LAMINAR VORTEX SHEDDING OFF TWO-DIMENSIONAL BLUFF BODIES

    E-print Network

    Stanford University

    CONTROL AND SUPPRESSION OF LAMINAR VORTEX SHEDDING OFF TWO-DIMENSIONAL BLUFF BODIES A DISSERTATION #12;Abstract The focus of this research is on the control and suppression of vortex shedding of flow instabilities in the laminar shedding regime. Both bounded and unbounded flow conditions are examined

  5. 75 FR 65230 - Drawbridge Operation Regulation; Arkansas Waterway, Pine Bluff, AR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-22

    ...) entitled Drawbridge Operation Regulation; Arkansas Waterway, Pine Bluff, AR in the Federal Register (75 FR... has a substantial direct effect on State or local governments and would either preempt State law or... effect on one or more Indian tribes, on the relationship between the Federal Government and Indian...

  6. Maastrichtian ammonites chiefly from the Prairie Bluff Chalk in Alabama and Mississippi

    USGS Publications Warehouse

    Cobban, W.A.; Kennedy, W.J.

    1995-01-01

    The Prairie Bluff Chalk of Alabama and Mississippi yields a diverse ammonite fauna of Maastrichtian age. Twenty-eight species, of which three are new, are recorded. The bulk of the fauna can be referred to a Discoscaphites conradi assemblage zone, but some elements in the fauna are significantly older. -Authors

  7. 78 FR 20942 - Niobrara Confluence and Ponca Bluffs Conservation Areas, NE and SD; Draft Environmental Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ...We, U.S. Fish and Wildlife Service (FWS) and the National Park Service (NPS), as lead agencies, announce the availability of a draft environmental impact statement (DEIS) and land protection plan (LPP) for the proposed Niobrara Confluence Conservation Area and Ponca Bluffs Conservation Area in Nebraska and South Dakota for public review and comment. In these documents, we describe......

  8. Investigations of air flow behavior past a conical bluff body using particle imaging velocimetry

    NASA Astrophysics Data System (ADS)

    Dutka, Marcin; Ditaranto, Mario; Løvås, Terese

    2015-11-01

    An annular jet flow past conical bluff body in an original configuration was investigated using particle imaging velocimetry for Reynolds ( Re) numbers between 4900 and 58,800. The studied geometrical configuration finds its application in a novel low NO x burner; therefore, the flow conditions corresponding to burner operation were investigated in detail. It was found that the flow is laminar at Re = 4900 and the transition from a laminar to a turbulent flow regime starts at Re = 9800-14,700. The length of the recirculation zone increases abruptly when the flow becomes turbulent and is independent of the Re number within the turbulent flow regime. The fraction of the total flow rate representing flow circulating in the recirculation zone is relatively constant for the investigated flows. An increase in main stream velocity implies proportional decrease in the residence time in the recirculation zone observed within the turbulent flow regime. Two types of coherent structures shed from the trailing edge of the bluff body are identified using proper orthogonal decomposition technique. The first is vortices that cross the centerline of the bluff body and travel downstream along the centerline. The second is smaller vortex structures that are shed alternately from the trailing edge of the bluff body.

  9. Experiments to investigate direct containment heating phenomena with scaled models of the Calvert Cliffs Nuclear Power Plant

    SciTech Connect

    Blanchat, T.K.; Pilch, M.M.; Allen, M.D.

    1997-02-01

    The Surtsey Test Facility is used to perform scaled experiments simulating High Pressure Melt Ejection accidents in a nuclear power plant (NPP). The experiments investigate the effects of direct containment heating (DCH) on the containment load. The results from Zion and Surry experiments can be extrapolated to other Westinghouse plants, but predicted containment loads cannot be generalized to all Combustion Engineering (CE) plants. Five CE plants have melt dispersal flow paths which circumvent the main mitigation of containment compartmentalization in most Westinghouse PWRs. Calvert Cliff-like plant geometries and the impact of codispersed water were addressed as part of the DCH issue resolution. Integral effects tests were performed with a scale model of the Calvert Cliffs NPP inside the Surtsey test vessel. The experiments investigated the effects of codispersal of water, steam, and molten core stimulant materials on DCH loads under prototypic accident conditions and plant configurations. The results indicated that large amounts of coejected water reduced the DCH load by a small amount. Large amounts of debris were dispersed from the cavity to the upper dome (via the annular gap). 22 refs., 84 figs., 30 tabs.

  10. Bluff body fluid dynamics of a D-section with moving surface boundary-layer control

    SciTech Connect

    Munshi, S.R.; Modi, V.J.; Yokomizo, Toshio

    1995-12-01

    Wind effects on bluff structures include higher drag force, vortex resonance and galloping type instabilities. Vibrations of tall buildings, bridges, smokestacks etc. have been of interest to scientists and engineers. Recent advances in material science and structural design have led to structures with reduced stiffness making them prone to wind, earthquake, as well as ocean waves and current excited oscillations. The present paper addresses this issue fundamentally through a comprehensive study aimed at the Moving Surface Boundary-layer Control (MSBC) of the classical D-section type bluff geometry which is susceptible to both vortex resonance and galloping type of instabilities. Extensive wind tunnel, numerical and flow visualization studies suggest that the concept of the MSBC represents a versatile tool for drag reduction and vibration control of the D-section.

  11. Aerodynamic drag reduction apparatus for gap-divided bluff bodies such as tractor-trailers

    DOEpatents

    Ortega, Jason M. (Pacifica, CA); Salari, Kambiz (Livermore, CA)

    2006-07-11

    An apparatus for reducing the aerodynamic drag of a bluff-bodied vehicle such as a tractor-trailer in a flowstream, the bluff-bodied vehicle of a type having a leading portion, a trailing portion connected to the leading portion, and a gap between the leading and trailing portions defining a recirculation zone. The apparatus is preferably a baffle assembly, such as a vertical panel, adapted to span a width of the gap between the leading and trailing portions so as to impede cross-flow through the gap, with the span of the baffle assembly automatically adjusting for variations in the gap width when the leading and trailing portions pivot relative to each other.

  12. Modeling erosion of ice-rich permafrost bluffs along the Alaskan Beaufort Sea coast

    NASA Astrophysics Data System (ADS)

    Barnhart, Katherine R.; Anderson, Robert S.; Overeem, Irina; Wobus, Cameron; Clow, Gary D.; Urban, Frank E.

    2014-05-01

    The Arctic climate is changing, inducing accelerating retreat of ice-rich permafrost coastal bluffs. Along Alaska's Beaufort Sea coast, erosion rates have increased roughly threefold from 6.8 to 19 m yr-1 since 1955 while the sea ice-free season has increased roughly twofold from 45 to 100 days since 1979. We develop a numerical model of bluff retreat to assess the relative roles of the length of sea ice-free season, sea level, water temperature, nearshore wavefield, and permafrost temperature in controlling erosion rates in this setting. The model captures the processes of erosion observed in short-term monitoring experiments along the Beaufort Sea coast, including evolution of melt notches, topple of ice wedge-bounded blocks, and degradation of these blocks. Model results agree with time-lapse imagery of bluff evolution and time series of ocean-based instrumentation. Erosion is highly episodic with 40% of erosion is accomplished during less than 5% of the sea ice-free season. Among the formulations of the submarine erosion rate we assessed, we advocate those that employ both water temperature and nearshore wavefield. As high water levels are a prerequisite for erosion, any future changes that increase the frequency with which water levels exceed the base of the bluffs will increase rates of coastal erosion. The certain increases in sea level and potential changes in storminess will both contribute to this effect. As water temperature also influences erosion rates, any further expansion of the sea ice-free season into the midsummer period of greatest insolation is likely to result in an additional increase in coastal retreat rates.

  13. THEORY ON DEVELOPMENT OF MOUNDS NEAR RED BLUFF, CALIF. By HAROLD A. GANGMARK, Fisllery Biologist, and F. BRUCE SANFORD, Chemist-in-Charge. BRANCH OF REPORTS,

    E-print Network

    THEORY ON DEVELOPMENT OF MOUNDS NEAR RED BLUFF, CALIF. By HAROLD A. GANGMARK, Fisllery Biologist Photographs are presented showing mounds iIi var- ious stages of development in the flood zone of the Sacramento River near Red Bluff, Calif., and the ter- Rounded mounds of earth, such as in figure 1, nre found

  14. Calvert Cliffs Nuclear Power Plant Life Cycle Management/License Renewal Program: Containment system component evaluation and program evaluation. Final report

    SciTech Connect

    Doroshuk, B.W.; Tilden, B.M.; Tucker, R.L.; Hostetler, D.R.; Tai, T.

    1995-03-01

    Central to the Life Cycle Management (LCM) Program for the Calvert Cliffs Nuclear Power Plant (CCNPP) plant is its Integrated Plant Assessment (IPA) process. The IPA is a comprehensive, systematic evaluation of the effectiveness of age-related degradation management for the plant`s important systems, structures, and components. Components of structures identified as functionally important and within the scope of license renewal in the screening step are evaluated to determine if they are subject to aging management review. For those that are, further evaluations of aging issues are performed. At Calvert Cliffs, a detailed method and procedures for conducting component evaluations of structures have been developed and thoroughly tested. The development and application of these procedures have resolved problems that other utilities can avoid by adapting these methods to their own plants. The first report of this series contains an overview of the LCM and IPA process. This report, which is another in the series of EPRI reports on the Calvert Cliffs IPA process, describes the methodology for performing component and program evaluations for structures.

  15. Return to Coalsack Bluff and the Permian Triassic boundary in Antarctica

    NASA Astrophysics Data System (ADS)

    Retallack, Gregory J.; Greaver, Tara; Jahren, A. Hope

    2007-01-01

    Coalsack Bluff was the first discovery site in Antarctica for the latest Permian to earliest Triassic reptile Lystrosaurus. This together with discovery of Permian Glossopteris leaves during the heroic age of Antarctic exploration, indicated not only that Antarctica was part of Gondwanaland, but also that Antarctic rocks recorded faunas from the greatest of all mass extinctions at the Permian-Triassic boundary. Pinpointing the exact stratigraphic level of this life crisis has recently become possible using ? 13C values in terrestrial organic matter. Multiple, short-lived events of 13C depletion may reflect carbon cycle crises, with the isotopic change a measure of terrestrial and atmospheric disequilibrium. Additional evidence for ecosystem reorganization came from changes in paleosol types and their root traces. Such studies previously completed at the Antarctic localities of Graphite Peak, Mount Crean, Portal Mountain, Shapeless Mountain and Allan Hills, are here extended to Coalsack Bluff. Carbon isotopic values in Permian rocks at Coalsack Bluff average - 23.08 ± 0.25‰, but begin to decline within the last coal with leaves ( Glossopteris), roots ( Vertebraria) and permineralized stumps ( Araucarioxylon) of glossopterids. The low point in ä 13C values is - 27.19‰ at 5.6 m above the last coal, which is capped by unusually abundant pyrite, and a claystone breccia with common clasts of redeposited clayey soils. Above this are massive quartz-rich sandstones of braided streams, considered a geomorphic response to deforestation and soil erosion following the mass extinction. Distinctive berthierine-bearing paleosols (Dolores pedotype) within these sandstones have unoxidized iron taken as evidence of severe groundwater hypoxia. Other paleosols at this stratigraphic level are like those in other Early Triassic rocks of Antarctica, which indicate unusually warm and humid conditions for such high paleolatitude lowlands. Waterlogging is also indicated by newly discovered kinds of paleosol (Ernest pedotype) with groundwater calcretes. The lack of peat accumulation in such waterlogged lowlands, berthierine in paleosols and large negative carbon isotopic shift at Coalsack Bluff support the idea of atmospheric pollution with methane from submarine and permafrost clathrates as a cause for the Permian-Triassic mass extinction. Hypoxic soils would have killed lowland plants by preventing root respiration and hypoxic air would have challenged vertebrates with pulmonary edema. Causes for catastrophic methane release remain unclear. Flood basalt eruptions, dolerite intrusions into coal measures, submarine landslides, tectonic faulting, and bolide impact suggested for episodes of methane release at other times are also plausible for the Permian-Triassic boundary.

  16. 230. CCC Camp NP21 was established at the Bluffs (Doughton ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    230. CCC Camp NP-21 was established at the Bluffs (Doughton Park) located on what is now the Doughton Park Maintenance Area. It opened September 1, 1938 and was abandoned July 17, 1942. Crews were assigned to the first landscape development on the parkway in the Cumberland Knob Area. This work entailed removal of debris and downed wood, slope flattening and rounding, seeding shoulders and planting along the road, and improvement of fields and forest to the side of the roadway. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  17. Data supporting the screening risk assessment for the Pine Bluff Arsenal Chemical Demilitarization Facility. Final report

    SciTech Connect

    Legg, W.E.

    1995-08-01

    The Pine Bluff Arsenal is a U.S. Army Armament, Munitions, and Chemical Command (AMCCOM) facility located in Jefferson County, Arkansas; 30 miles southeast of Little Rock and eight miles northwest of Pine Bluff, Arkansas. The arsenal encompasses 14,956 acres of land, most of which (61 percent) is designated as open space/clearance zones. Most of this area is managed for forest products under the arsenal`s timber management program. Approximately 21 percent of the facility supports the munitions supply and storage operations (18 percent conventional munitions, 3 percent chemical agent and munitions). Six percent of the facility contains the conventional munitions maintenance and production areas. The remaining 15 percent of the property is comprised of other administrative, operational, and housing areas along with the Food and Drug Administration`s National Center for Toxicological Research. The arsenal has been in operation since 1941 and has been storing lethal unitary chemical agents since 1942. The arsenal is one of eight sites that stores lethal unitary agents in the United States.

  18. Power production locality of bluff body flutter mills using fully coupled 2D direct numerical simulation

    NASA Astrophysics Data System (ADS)

    Kuhl, J. M.; Desjardin, P. E.

    2012-01-01

    Two-dimensional, fully coupled direct numerical simulations (DNS) are conducted to examine the local energy dynamics of a flexible cantilevered plate in the wake of a two-dimensional circular cylinder. The motion of the cantilevered plate is described using a finite element formulation and a fully compressible, finite volume Navier Stokes solver is used to compute the flow field. A sharp interface level set method is employed in conjunction with a ghost fluid method to describe the immersed boundaries of the bluff body and flexible plate. DNS is first conducted to validate the numerical methodology and compared with previous studies of flexible cantilevered plates and flow over bluff bodies; excellent agreement with previous results is observed. A newly defined power production/loss geometry metric is introduced based on surface curvature and plate velocity. The metric is found to be useful for determining which sections of the plate will produce energy based on curvature and deflection rate. Scatter plots and probability measures are presented showing a high correlation between the direction of energy transfer (i.e., to or from the plate) and the sign of the newly defined curvature-deflection-rate metric. The findings from this study suggest that a simple local geometry/kinematic based metric can be devised to aid in the development and design of flexible wind energy harvesting flutter mills.

  19. The molluscan fauna of the Alum Bluff group of Florida, Part II, Astartacea, Carditacea, Chamacea

    USGS Publications Warehouse

    Gardner, Julia

    1926-01-01

    The first of the series of papers upon the Mollusca of the Alum Bluff group covered the orders of the Prionodesmacea and the Anomalodesmacea. The Mollusca were by the beginning of Miocene time so far advances in development that the great majority are included under the highest of the three orders, the Teleodesmacea, characterized in the adult stages by the differentiation of the hinge teeth into distinct cardinals and laterals. This paper, the second of the series, covers the most primitive of the Teleodesmacea in the Alum Bluff group. All three of the superfamilies considered - the Astartacea, the Carditaeea, and the Chamacea-are included under Dall's group of the Diogenodonta, which is characterized in the normal forms by one or two laterals and not more than three cardinals. The Carditacea are very closely related to the Astartacea in hinge armature but differ in the development of a pronounced radial sculpture. The Chamacea have until recently been considered an offshooting group from the Carditacea that have been greatly modified by their sessile habit. Some doubt has been thrown upon this relationship by the late morphologic studies of Odhner.

  20. A RETRAN model of the Calvert Cliffs-1 pressurized water reactor for assessing the safety implications of control systems

    SciTech Connect

    Renier, J P.A.; Smith, O L

    1987-03-01

    The failure mode and effects analysis of Calvert Cliffs-1 identified sequences of events judged sufficiently complex to merit further analysis in detailed dynamic simulations. This report describes the RETRAN model developed for this purpose and the results obtained. The mathematical tool was RETRAN2/Mod3, the latest version of a widely used and extensively validated thermal-hydraulics production code obtained by license agreement with the developer, Electric Power Research Institute, and installed on the ORNL BM-3033 computers. RETRAN2 is based on a first-principles methodology that treats two-phase flow with slip. Thermal equilibrium of phases is assumed except in the pressurizer, where non-equilibrium processes are important and special methodology is used. Heat transfer in solids is obtained from the conventional conduction equation. Point or 1-D kinetics is available for the reactor core. The fundamental methodology is supplemented with a broad list of process submodels that calculate heat transfer coefficients, fluid and metal state properties, choked flow, form and wall friction losses, and other parameters. Also supplied are component submodels for various types of valves and pumps, the latter of which incorporate four-quadrant characteristics for components in which two-phase or reverse flow may be expected, and head versus flow curves for others. Extensive input allows the code to be highly particularized to a specific plant. The major investment in time and manpower occurs in setting up the base case; changes are comparatively easy to implement.

  1. Review of thermal-hydraulic calculations for Calvert Cliffs and H. B. Robinson PTS study. [Pressurized thermal shock

    SciTech Connect

    Jo, J.H.; Yuelys-Miksis, C.; Rohatgi, U.S.

    1984-01-01

    Thermal-hydraulic transient calculations performed by LANL using the TRAC-PF1 code and by INEL using the RELAP5 code for the USNRC pressurized thermal shock (PTS) study of the Calvert Cliffs and H.B. Robinson Nuclear Power Plants have been reviewed at BNL including the input decks and steady state calculations. Furthermore, six transients for each plant have been selected for the in-depth review. Simple hand calculations based on the mass and energy balances of the entire reactor system, have been performed to predict the temperature and pressure of the reactor system, and the results have been compared with those obtained by the code calculation. In general, the temperatures and pressures of the primary system calculated by the codes have been very reasonable. The secondary pressures calculated by TRAC appear to indicate that the codes have some difficulty with the condensation model and further work is needed to assess the code calculation of the U-tube steam generator pressure when the cold auxiliary feedwater is introduced to the steam generator. However, it is not expected that this uncertainty would affect the transient calculations significantly.

  2. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207.169 Section 207.169 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE...

  3. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207.169 Section 207.169 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE...

  4. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207.169 Section 207.169 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE...

  5. 33 CFR 207.169 - Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Oklawaha River, navigation lock and dam at Moss Bluff, Fla.; use, administration, and navigation. 207.169 Section 207.169 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE...

  6. Alteration and geochemical zoning in Bodie Bluff, Bodie mining district, eastern California

    USGS Publications Warehouse

    Herrera, P.A.; Closs, L.G.; Silberman, M.L.

    1993-01-01

    Banded, epithermal quartz-adularia veins have produced about 1.5 million ounces of gold and 7 million ounces of silver from the Bodie mining district, eastern California. The veins cut dacitic lava flows, pyroclastic rocks and intrusions. Sinter boulders occur in a graben structure at the top of Bodie Bluff and fragments of sinter and mineralized quartz veins occur in hydrothermal breccias nearby. Explosive venting evidently was part of the evolution of the ore-forming geothermal systems which, at one time, must had reached the paleosurface. Previous reconnaissance studies at Bodie Bluff suggested that the geometry of alteration mineral assemblages and distribution of some of the major and trace elements throughout the system correspond to those predicted by models of hot-spring, volcanic rock hosted precious metal deposits (Silberman, 1982; Silberman and Berger, 1985). The current study was undertaken to evaluate these sugestions further. About 500 samples of quartz veins and altered rocks, including sinter, collected over a vertical extent of 200 meters within Bodie Bluff were petrographically examined and chemically analyzed for trace elements by emission spectrographic and atomic absorption methods. Sixty-five samples were analyzed for major elements by X-ray fluorescence methods. The results of these analyses showed that, in general, alteration mineral assemblage and vertical geochemical zoning patterns follow those predicted for hot-spring deposits, but that geochemical zoning patterns for sinter and quartz veins (siliceous deposits), and altered wall rocks are not always similar. The predicted depth-concentration patterns for some elements, notably Au, Ag, Hg, and Tl in quartz veins, and Hg, As and Ag in wall rocks were not as expected, or were perturbed by the main ore producing zone. For both quartz veins and altered wall rocks, the main ore zone had elevated metal contents. Increased concentration of many of these elements could indicate proximity to this zone. However, irregularities in the distribution of some key elements, such as Au and Ag, relative to the predictive models suggest that a larger suite of elements be considered for exploration for ore zones within the district. ?? 1993.

  7. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power station: 1995

    SciTech Connect

    Jones, T.S.; Frithsen, J.B.; McLean, R.I.

    1997-02-01

    The Maryland Power Plant Research Program monitors concentrations of natural, weapons, and power plant produced radionuclides in environmental samples collected from the Chesapeake Bay in the vicinity of the Calvert Cliffs Nuclear Power Plant (CCNPP) and from the Susquehanna River-Chesapeake Bay system in the vicinity of Peach Bottom Atomic Power Station (PBAPS). The purpose of this monitoring is to determine the fate, transport, and potential effects of power plant produced radionuclides. Radionuclide concentrations in shellfish, finfish, aquatic vegetation, and sediment were measured using high-resolution gamma spectrometry. Radionuclides in environmental samples originated from natural sources, atmospheric weapons testing, and normal operations of CCNPP and PBAPS.

  8. Three-dimensional calculations of transient fluid-thermal mixing in the downcomer of the Calvert Cliffs-1 plant using SOLA-PTS

    SciTech Connect

    Daly, B.J.

    1984-04-01

    The SOLA-PTS code has been used to analyze transient fluid-thermal mixing in a 180/sup 0/ sector of the downcomer and a cold leg of the Calvert Cliffs-1 plant for three assumed accident scenarios. The inlet boundary conditions for these calculations were obtained from mass flow rates and temperatures that were computed in systems code studies. The results of the three-dimensional SOLA-PTS calculations indicated that a pressurized thermal shock risk was mitigated for these accident scenarios as the result of the particular circulation patterns that developed in the downcomer.

  9. High-Speed Linear Raman Spectroscopy for Instability Analysis of a Bluff Body Flame

    NASA Technical Reports Server (NTRS)

    Kojima, Jun; Fischer, David

    2013-01-01

    We report a high-speed laser diagnostics technique based on point-wise linear Raman spectroscopy for measuring the frequency content of a CH4-air premixed flame stabilized behind a circular bluff body. The technique, which primarily employs a Nd:YLF pulsed laser and a fast image-intensified CCD camera, successfully measures the time evolution of scalar parameters (N2, O2, CH4, and H2O) in the vortex-induced flame instability at a data rate of 1 kHz. Oscillation of the V-shaped flame front is quantified through frequency analysis of the combustion species data and their correlations. This technique promises to be a useful diagnostics tool for combustion instability studies.

  10. Monte Carlo studies for neutrino detection from Minna Bluff and other mountainsides in Antarctica

    NASA Astrophysics Data System (ADS)

    Barrella, Taylor; Vieregg, Abigail; Saltzberg, David; Anita Collaboration

    2011-04-01

    We present a simple Monte Carlo simulation for a possible neutrino detection experiment. The detector would be composed of an array of radio antennas on Minna Bluff, Antarctica, designed to detect Cherenkov radiation from ultra-high-energy neutrinos. The location, overlooking the Ross Ice Shelf, is ideal because of its proximity to McMurdo station. We show the validity of the results by comparing with the Monte Carlo simulation established for the ANITA (Antarctic Impulsive Transient Antenna) experiment. We also present new results on an attenuation length measurement of the ice shelf in the 200-1200 MHz range. Though the results predict less than one event per year, we discovered a possible alternative of placing the detector on the Transantarctic Mountains to overlook the deeper ice sheet.

  11. A dry-surface coating method for visualization of separation. [bluff bodies

    NASA Technical Reports Server (NTRS)

    Sadeh, W. Z.; Brauer, H. J.; Durgin, J. R.

    1980-01-01

    A relatively simple and reasonably accurate dry-surface coating method for visualization of the separation line on a bluff body was devised and successfully tested. This technique is based on the color reaction of a dry film containing a pH indicator with an appropriate gas released in the body wake. The dry-surface coating method is effective at any Reynolds number and for both incident laminar and turbulent flows. It further supplies a colorful permanent of consistently good photographic quality of the separation line. The effectiveness and accuracy of this technique were tested in visualizing the separation angle on a circular cylinder in both laminar and turbulent crossflows at subcritical Reynolds numbers. Separation angles revealed by the visualization were within + or - 4 percent of their counterparts deduced from the mean wall pressure distribution.

  12. Response dynamics of bluff-body stabilized conical premixed turbulent flames with spatial mixture gradients

    SciTech Connect

    Chaudhuri, Swetaprovo; Cetegen, Baki M.

    2009-03-15

    Response of bluff-body stabilized conical turbulent premixed flames was experimentally studied for a range of excitation frequencies (10-400 Hz), mean flow velocities (5, 10 and 15 m/s) and three different spatial mixture distributions (uniform, inner and outer enrichment). Upstream excitation was provided by a loudspeaker producing velocity oscillation amplitudes of about 8% of the mean flow velocity. Flame response was detected by a photomultiplier observing the CH{sup *} emission from the flame. The studied turbulent flames exhibited transfer function characteristics of a low-pass filter with a cutoff Strouhal number between 0.08 and 0.12. The amplification factors at low frequencies ranged from 2 to 20 and generally increased for mean flow velocities from 5 to 15 m/s. The highest levels of amplification were found for the outer mixture enrichment followed in decreasing order by uniform and inner mixture gradient cases. The high levels of flame response for the outer enrichment case were attributed to the enhanced flame-vortex interaction in outer jet shear layer. At high excitation levels (u{sup '}/U{sub m}{approx}0.3) for U{sub m}=5 m/ s where non-linear flame response is expected, the flame exhibited a reduced amplitude response in the frequency range between 40 and 100 Hz for the uniform and outer equivalence ratio gradient cases and no discernible effect for the inner equivalence ratio gradient. In all cases, transfer function phase was found to vary linearly with excitation frequency. Finally, a relationship between the amplitude characteristics of the bluff-body wake transfer function and flame blowoff equivalence ratio was presented. (author)

  13. Experimental investigation of galloping piezoelectric energy harvesters with square bluff bodies

    NASA Astrophysics Data System (ADS)

    Ewere, Felix; Wang, Gang; Cain, Brian

    2014-10-01

    In this paper, both a baseline galloping piezoelectric energy harvester (GPEH) with a square bluff body and an improved GPEH with an impact bump stop are tested in a wind tunnel in order to determine the system damping, electrical response and limit cycle oscillation (LCO) amplitude. In the baseline GPEH, harvested voltage, LCO amplitude and damping ratio vary with wind velocity and electrical load. They all increase with increasing wind velocity under the same electrical load. Under each wind velocity, the damping ratio increases from the short circuit load, reaches a peak value at the electrical load resulting in a maximum voltage, and reduces the value at the open circuit load. The LCO amplitude shows the opposite trend compared to the damping case. It decreases as the electrical resistance load increases and reaches the minimum value when the damping ratio is highest. A resistance load of 100 k? yields a maximum peak power output. The impact stop is introduced to reduce bending stresses and improve the fatigue life of the baseline GPEH. The performance of the improved GPEH depends on the stop design parameters such as gap size, stop location and contact area. Comprehensive tests were conducted to investigate the effect of each parameter on the performance of the improved GPEH and an optimal bump stop configuration was determined. Compared to the expected proportional reduction in both electrical and structural responses, a maximum 70% reduction in LCO amplitude and only a maximum 20% reduction in harvested voltage are achieved in our optimal improved GPEH. The time variable and motion dependent aerodynamic forces acting on the bluff body could contribute to this. In summary, comprehensive experimental evaluations were conducted to characterize the performance of both baseline GPEHs and improved GPEHs. The baseline GPEH service life can be significantly improved by incorporating an impact bump stop. The improved GPEH design provides a practical solution to harvest electricity from wind-induced vibration.

  14. Experimental and Numerical Investigation of Flow Structures around Cylindrical Bluff Bodies

    NASA Astrophysics Data System (ADS)

    Yagmur, Sercan; Dogan, Sercan; Aksoy, Muharrem H.; Canli, Eyub; Ozgoren, Muammer

    2015-05-01

    The understanding and quantitative prediction of velocity and pressure fluctuations in turbulent flows around such bluff bodies have been evolving over the years. The main aim of the present work is to investigate experimentally and numerically the flow field in the wake region of different bluff bodies such as circular, square and triangle cross section cylinders placed horizontally perpendicular to the uniform flow. The experimental studies were performed by Particle Image Velocimetry (PIV) method in an open water channel at Reynolds numbers 5000 and 10000 defined according to the characteristic lengths of the cylinders in the facilities of Selcuk University of Advanced Technology Research and Application Center in Turkey. The experimental results are compared to the numerical results obtained by means of transient simulation with LES turbulence model of ANSYS-Fluent Software. It is shown that the numerical and experimental results have a good agreement in respect of the instantaneous and time-averaged flow field patterns of vorticity, velocity component streamwise direction and streamline topology. In addition, drag coefficient of the geometries were also numerically calculated. For all geometries the wake length in x and y directions and size of the foci of the streamlines are decreasing by increasing Reynolds numbers in time-averaged results. The time-averaged flow patterns of both experimental and numerical results have considerable symmetry with respect to the centerline of each cylinder. Contours of the time-averaged stream wise velocity for Re=10000 demonstrate that the stagnation point around the symmetry plane moves further upstream for all cylinders in accordance with Re=5000. The maximum drag coefficient value was yielded for the square cross-section cylinder as 1.78 due to the sharp-edged geometry.

  15. Terrestrial LIDAR investigation of the December 2003 and January 2007 activations of the Northridge Bluff landslide, Daly City, California

    USGS Publications Warehouse

    Collins, Brian D.; Kayen, Robert; Reiss, Thomas; Sitar, Nicholas

    2007-01-01

    On December 20, 2003 and again on January 1, 2007, landslides occurred along the coastal bluff that forms the west boundary of Daly City, California sending debris as far as 290 meters downhill and 90 meters into the ocean. This area is known for large landslide events where 150-meter tall coastal bluffs extend southward along the west boundary of San Francisco and San Mateo Counties (Fig. 1). The 2003 and 2007 landslide events occurred west of Northridge Drive in Daly City and just south of Avalon Canyon, which bisects the bluffs in this area (Fig. 2). Residential development, utility lines and roads occupy the land immediately east of this location. As part of a comprehensive project to investigate the failure mechanisms of coastal bluff landslides in weakly lithified sediments along the west coast of the United States, members of the U.S. Geologic Survey (USGS) Coastal and Marine Geology (CMG) Program performed reconnaissance mapping of these landslide events including collection of high-resolution topographic data using CMG's terrestrial LIDAR laser scanning system. This report provides a brief background on each landslide event and presents topographic datasets collected following each event. Downloadable contour data, images, and FGDC-compliant metadata of the surfaces generated from the LIDAR data are also provided. LIDAR data collection and processing techniques used to generate the datasets are outlined. Geometric and volumetric measurements are also presented along with high-resolution cross-sections through various areas of the slide masses and discussion concerning the slides present (2007) configuration is provided.

  16. Boattail Plates With Non-Rectangular Geometries For Reducing Aerodynamic Base Drag Of A Bluff Body In Ground Effect

    DOEpatents

    Ortega, Jason M. (Pacifica, CA); Sabari, Kambiz (Livermore, CA)

    2006-03-07

    An apparatus for reducing the aerodynamic base drag of a bluff body having a leading end, a trailing end, a top surface, opposing left and right side surfaces, and a base surface at the trailing end substantially normal to a longitudinal centerline of the bluff body, with the base surface joined (1) to the left side surface at a left trailing edge, (2) to the right side surface at a right trailing edge, and (3) to the top surface at a top trailing edge. The apparatus includes left and right vertical boattail plates which are orthogonally attached to the base surface of the bluff body and inwardly offset from the left and right trailing edges, respectively. This produces left and right vertical channels which generate, in a flowstream substantially parallel to the longitudinal centerline, respective left and right vertically-aligned vortical structures, with the left and right vertical boattail plates each having a plate width defined by a rear edge of the plate spaced from the base surface. Each plate also has a peak plate width at a location between top and bottom ends of the plate corresponding to a peak vortex of the respective vertically-aligned vortical structures.

  17. Spatio-temporal Dynamics of Coastal Bluff Erosion near Barrow Alaska over the Past Decade

    NASA Astrophysics Data System (ADS)

    Kofoed, K. B.; Lopez, A. F.; Aguirre, A.; Aiken, Q.; Cody, R. P.; Gaylord, A. G.; Manley, W. F.; Green, E.; Nelson, L.; Lougheed, V.; Velasco, A. A.; Tweedie, C. E.

    2014-12-01

    Arctic coastal systems are recognized as being one of the most climate change - vulnerable ecosystems on Earth and represent a complex nexus for examining change at the interface between marine, terrestrial, atmospheric, cryospheric and social systems. Although coastal erosion has received increased attention in the Arctic, few studies have examined the fine scale spatiotemporal dynamics and variability in erosion rates relative to the range of factors that act concomitantly to control erosion (e.g. duration of ice free seas, bathymetry, wave action, sea and air temperature, landscape morphology). This study reports on the spatiotemporal dynamics of annual DGPS surveys of eroding coastal bluffs in northern Alaska near the city of Barrow. Surveys along ca. 11km of the Elson Lagoon coast have been conducted since 2002 and additional surveys along ca. 120km of Elson Lagoon and Chuckhi Sea coast have been conducted since 2013. There has been strong inter-annual spatiotemporal variability in erosion rates with no indication of a long term change in erosion rates over time. Factors controlling wave intensity (e.g. wind run, off shore bathymetry, aspect of the coast relative to prevailing winds) explain most variability in erosion rates over time but during relatively calm periods, landscape history and morphology become more important. These findings highlight the extreme fine scale spatiotemporal heterogeneity in erosion rates along the Arctic Coast, and the importance of incorporating both storm-related climatic events and landscape characteristics when forecasting future environmental states in Arctic coastal landscapes. Case studies outlining new remote sensing technologies and future directions of study will also be outlined including terrestrial and airborne LiDAR, and Kite, UAV, and satellite imagery that is being used to derive and monitor topographic and hydrological change near eroding coastal bluffs; a wireless sensor network of micrometeorological and optical sensors; low cost tri-axial accelerometers that measure wave amplitude, period and azimuth; a survey vessel for mapping near shore bathymetry and water chemistry; and a web-based decision tool for improving management and planning of the coastal zone near Barrow.

  18. Multi-Point Velocity Correlations in the Wake of a Three-Dimensional Bluff Body

    NASA Astrophysics Data System (ADS)

    Shea, Patrick; Glauser, Mark

    2013-11-01

    Three-dimensional bluff-bodies known as turrets are commonly used for housing optical systems on airborne platforms. These geometries generate highly turbulent wakes that decrease the performance of the optical systems and the aircraft. The current experimental study used dynamic suction in both open and closed-loop control configurations to actively control the wake turret. The experiments were carried out at a Reynolds number of 5 × 105, and the flow field was characterized using stereoscopic PIV measurements acquired in the wake of the turret. These data were processed using traditional single-point statistics which showed that the active control system was able to significantly alter the wake of the turret. Using multi-point correlations, turbulent characteristics such as the integral length scale can be calculated. For the turret wake, estimates of the integral length scales were found to be highly dependent upon the region of the flow that was evaluated, especially when comparing the shear layers to the center of the wake. With the application of the active control, the integral length scales were generally found to increase.

  19. Biomimetic bluff body drag reduction by self-adaptive porous flaps

    E-print Network

    Mazellier, Nicolas; Kourta, Azeddine

    2011-01-01

    The performances of an original passive control system based on a biomimetic approach are assessed by investigating the flow over a bluff-body. This control device consists in a couple of flaps made from the combination of a rigid plastic skeleton coated with a porous fabric mimicking the shaft and the vane of the bird's feathers, respectively. The sides of a square cylinder have been fitted with this system so as to enable the flaps to freely rotate around their leading edge. This feature allows the movable flaps to self-adapt to the flow conditions. Comparing both the uncontrolled and the controlled flow, a significant drag reduction (up to 22%) has been obtained over a broad range of Reynolds number. The investigation of the mean flow reveals a noticeable modification of the flow topology at large scale in the vicinity of the controlled cylinder accounting for the increase of the pressure base in comparison with the natural flow. Meanwhile, the study of the relative motion of both flaps points out that the...

  20. Biomimetic bluff body drag reduction by self-adaptive porous flaps

    NASA Astrophysics Data System (ADS)

    Mazellier, Nicolas; Feuvrier, Audrey; Kourta, Azeddine

    2012-01-01

    The performances of an original passive control system based on a biomimetic approach are assessed by investigating the flow over a bluff body. This control device consists of a couple of flaps made from the combination of a rigid plastic skeleton coated with a porous fabric mimicking the shaft and the vane of the bird's feathers, respectively. The sides of a square cylinder have been fitted with this system so that each flap can freely rotate around its leading edge. This feature allows the movable flaps to self-adapt to the flow conditions. Comparing both the uncontrolled and the controlled flow, a significant drag reduction ( ?22% on average) has been obtained over a broad range of Reynolds numbers. This improvement is related to the increase of the base pressure in the controlled case. The investigation of the mean flow reveals a noticeable modification of the flow topology at large scale in the vicinity of the controlled cylinder. Meanwhile, the study of the relative motion of both flaps highlights that their dynamics is sensitive to the Reynolds number. Furthermore, the analysis of the flow dynamics at large scale suggests a lock-in coupling between the flap motion and the vortex shedding.

  1. Erosional history of Cape Halkett and contemporary monitoring of bluff retreat, Beaufort Sea coast, Alaska

    USGS Publications Warehouse

    Jones, Benjamin M.; Arp, Christopher D.; Beck, Richard A.; Grosse, Guido; Webster, James M.; Urban, Frank E.

    2009-01-01

    Cape Halkett is located along the Beaufort Sea at the end of a low-lying tundra landscape. The area has been subject to major modifications over the last century as a result of erosion and migration of the coastline inland. Long-term mean annual erosion rates (1955-2009) for the entire cape are 7.6 m/yr, with a gradual increase in rates over the first five time periods of remotely sensed imagery analyzed and a large increase during the most recent time period. Division of the cape into three distinct coastal zones shows very different erosional patterns: the northeast-facing segment (Zone 1) showing a consistent and large increase; the southeast-facing segment (Zone 3) showing a gradual increase with recent, heightened erosion rates; and the east-facing segment (Zone 2) showing decreased rates due to the reformation of a sand and gravel spit. Monitoring of bluff erosion with time-lapse photography, differential GPS surveys, terrestrial and bathymetric surveys, and water level, sea and permafrost temperature data provide insights into the processes driving contemporary patterns of erosion and will provide valuable information for the prediction of future shoreline positions.

  2. Coherent substructure of turbulence near the stagnation zone of a bluff body

    NASA Technical Reports Server (NTRS)

    Sadeh, W. Z.; Brauer, H. J.

    1980-01-01

    The evolution of freestream turbulence in crossflow about a circular cylinder was studied in order to identify the existence of a coherent substructure which is the outcome of the amplification of freesteam turbulence by the stretching mechanism in diverging flow about a bluff body. Visualization of the flow events revealed the selective stretching of cross-vortex tubes and the emergence of an organized turbulent flow pattern near the cylinder stagnation zone. Significant amplification of the total turbulent energy of the streamwise fluctuating velocity was consistently monitored. Realization of selective amplification at scales larger than the neutral scale of the stagnation flow was indicated by the variation of the discrete streamwise turbulent energy. A most amplified scale, characteristic of the energy containing eddies within the coherent substructure and commensurate with the boundary-layer thickness, was detected. Penetration of the amplified turbulence into the cylinder boundary layer led to the retardation of separation and to a concurrent decrease in the drag coefficient at subcritical cylinder-diameter Reynolds numbers.

  3. Quartz and Hydrous Iron Oxides from the Bee Bluff Structure of South Texas

    NASA Astrophysics Data System (ADS)

    Graham, R. A.; Martin, M.; Thadhani, N. N.; Morosin, B.

    2006-07-01

    There is substantial information showing that the Bee Bluff structure is an impact site and that a residual crater can be identified. The thin hard cap of Carrizo Sandstone, Indio fm calcareous silt and a thin layer of iron-rich siltstone leads to impact processes in which the high pressure release wave proceeds promptly upward leading to a trapping of metamorphic products at the impact interface, a `bottom-up' pressure release. Release of water from goethite binder in the sandstone and from the iron-rich siltstone results in supersaturated steam in mixtures with iron and quartz compounds. Samples with quartz and hydrous iron oxide features are examined with optical microscopy, SEM, EDX and XRD. A quartz grain is found with a well defined PDF set. There is widespread amorphous quartz including lechatleriete. Nanocrystals of ?-goethite in the acicular form are common. A condensation sphere from the `Uvalde Crater Rosetta Stone' shows a complex mixture of hematite, goethite, and alpha quartz with a trace of trydimite. Numerous samples are yet to be analyzed. The crater appears to have features that can serve as an Earth analog to Mars craters. A companion paper in the present proceedings summarizes prior work, adds new site detail, reports impact-loading analysis, and describes overall features of impactite samples from the site.

  4. Biostratigraphy and paleoecology of Naples Bluff coastal section determined from diatoms and benthic foraminifers

    SciTech Connect

    Arends, R.G.; Blake, G.H.

    1986-04-01

    An integrated biostratigraphic and paleoecologic study of the Naples Bluff coastal section used diatoms and benthic foraminifers. This section, composed of a thick sequence of Tertiary marine rocks, represents one of the most completely exposed Neogene sections along the central coast of California. The interval examined in this study is 1800 ft thick, and represents early to late Miocene rocks and the overlying early Pliocene sediments. This sequence contains well-preserved diatom floras and benthic foraminiferal faunas that enabled us to integrate diatom biochronology with the provincial benthic foraminifer stages and to construct a sediment accumulation curve. Although generally abundant in this section, the benthic faunas are dominated by an inner marginal bathyal assemblage. However, rare deeper water assemblages occur in some samples. Five faunal events are recognized that indicate response to paleo-oceanographic and tectonic influences. The diatom assemblages in this section are relatively abundant and range from the Actinocyclus ingens zone to the Thalassiosira oestrupii zone of J.A. Barron. The diversity and abundance of these assemblages made precise age control for this section possible. A major unconformity or severely compressed interval developed between 15 and 9 Ma.

  5. Paleomagnetic and 40Ar/39Ar results from the Grant intrusive breccia and coparison to the Permian Downeys Bluff Sill; evidence for Permian igneous activity at Hicks Dome, southern Illinois Basin

    USGS Publications Warehouse

    Reynolds, Richard L.; Goldhaber, Martin B.; Snee, Lawrence W.

    1997-01-01

    Igneous processes at Hicks dome, a structural upwarp at lat 37.5 degrees N., long 88.4 degrees W. in the southern part of the Illinois Basin, may have thermally affected regional basinal fluid flow and may have provided fluorine for the formation of the Illinois-Kentucky Fluorspar district. The timing of both igneous activity and mineralization is poorly known. For this reason, we have dated an intrusive breccia at Hicks dome, the Grant intrusion, using 40Ar/39Ar geochronometric and paleomagnetic methods. Concordant plateau dates, giving Permian ages, were obtained from amphibole (272.1+or-0.7 [1 sigma] Ma) and phlogopite (272.7+or-0.7 [1 sigma] Ma). After alternating-field (AF) demagnetization, specimens that contain titanomagnetite-bearing igneous rock fragments give a mean remanent direction of declination (D)=168.4 degrees; inclination (I)=-8 degrees; alpha 95=8.6 degrees; number of specimens (N)=10; this direction yields a virtual geomagnetic pole (VGP) at lat 54.8 degrees N., long 119.0 degrees E., delta p=4.4 degrees, delta m=8.7 degrees, near the late Paleozoic part of the North American apparent pole wander path. A nearly identical magnetization was found for the nearby Downeys Bluff sill (previously dated at about 275+or-24 Ma by the Rb-Sr method), in southern Illinois. Both AF and thermal demagnetization isolated shallow, southeasterly remanent directions carried by magnetite in the sill and from pyrrhotite in the baked contact of the Upper Mississippian Downeys Bluff Limestone: D=158.6 degrees; I=-11.8 degrees; alpha 95=3.8 degrees; N=15, yielding a VGP at lat 53.0 degrees N., long 128.7 degrees E., delta p=2.0 degrees, delta m=3.9 degrees. The paleomagnetic results, isotopic dates, and petrographic evidence thus favor the acquisition of thermal remanent magnetization by the Grant breccia and the Downeys Bluff sill during the Permian. The isotopic dates record rapid cooling from temperatures greater than 550 degrees C to less than 300 degrees C (the closure temperatures for diffusion of 40Ar in amphibole and phlogopite, respectively) after emplacement during the Permian. The results further indicate that individual clasts of the Grant breccia were emplaced at temperatures greater than about 550 degrees C, the magnetization-blocking temperature of the titanomagnetite in the breccia, and that it cooled very rapidly,within less than 1-2 m.y. After cooling, the breccia was not affected by thermal perturbations greater than about 300 degrees C.

  6. Environmental radionuclide concentrations in the vicinity of the Calvert Cliffs Nuclear Power Plant and the Peach Bottom Atomic Power Station: 1996--1997. Final report

    SciTech Connect

    McLean, R.I.; Jones, T.S.

    1998-11-20

    The Maryland Power Plant Research Program monitors concentrations of natural, weapons, and power plant produced radionuclides in environmental samples collected from the Chesapeake Bay in the vicinity of the Calvert Cliffs Nuclear Power Plant (CCNPP) and from the Susquehanna River-Chesapeake Bay system in the vicinity of Peach Bottom Atomic Power Station (PBAPS). The purpose of this monitoring is to determine the fate, transport, and potential effects of power plant-produced radionuclides. This report contains a description of monitoring activities and data collected during the 1996 and 1997 calendar years. Radionuclide concentrations in shellfish, finfish, aquatic vegetation, and sediment were measured using high-resolution gamma spectrometry. Radionuclides in environmental samples originated from natural sources, historic atmospheric weapons testing, and normal operations of CCNPP and PBAPS.

  7. "Frog" Walker & Jim Calvert 

    E-print Network

    Unknown

    2011-08-17

    inoculation in frogs (Xenopus sp.). Oral immunization is a novel approach to eliciting immune responses in Xenopus. I propose that IgX will increase with oral inoculation compared to intraperitoneal injection. This would be the first demonstration of class...

  8. On the flame-generated vorticity dynamics of bluff-body stabilized premixed flames

    NASA Astrophysics Data System (ADS)

    Caramella, Lucia

    This investigation considers the dynamics of the flame-generated vorticity for a premixed, submerged bluff-body stabilized flame. Digital particle image velocimetry (DPIV) is used to obtain mean and instantaneous velocity and vorticity fields in four streamwise locations, capturing nearly the entire combustion chamber. The Mie scattering images which are collected for DPIV prove useful in determining the approximate location of the flame as indicated by a stark difference in seeding particle density caused by volumetric expansion. Examining the location of the flame fronts in relation to the mean velocity, mean vorticity, and corresponding instantaneous fields provides useful information about the interaction of the flame and the flow. Experiments characterize the far-field region in particular with a level of detail not previously afforded to this type of flow. The unique nature of the velocity and vorticity fields, as well as a change in rotation of the flame structures observed in the Mie scattering images, are explained by appealing to the baroclinic generation of vorticity. The baroclinic mechanism is activated when non-parallel pressure and density gradients are present. Mean static pressure measurements at the combustion chamber wall allow inferences about the pressure field to be made. The coupling that exists among pressure, heat release, and baroclinic generation is also acknowledged and will influence strategies for control of the baroclinic mechanism. Particular details of the coupling remain unclear, nevertheless improved understanding can lead to advancements in combustion efficiency. Simple scaling of the problem allows a prediction of baroclinic vorticity generation to be obtained. Further insight into the dynamics in the region of interest are provided using CH* filtered and unfiltered chemiluminescence images.

  9. Drag reduction on a rectangular bluff body with base flaps and fluidic oscillators

    NASA Astrophysics Data System (ADS)

    Schmidt, H.-J.; Woszidlo, R.; Nayeri, C. N.; Paschereit, C. O.

    2015-07-01

    The present paper investigates drag reduction on a rectangular bluff body by employing base flaps and controlling flow separation with fluidic oscillators. Wind tunnel experiments are conducted to assess the influence of various parameters. The flap length has to be sufficiently long to shift the wake structures far enough downstream away from the base plate. Any additional increase in flap length does not yield any further benefits. The flap angle has to be large enough to provide a sufficient inward deflection of the outer flow. If the angle is too large, actuation becomes inefficient due to the pressure gradient imposed by the opposite side of the base perimeter. Furthermore, the flaps at high deflection angles provide additional area for low pressure to act in the streamwise direction and therefore negate the positive effects of actuation. The required actuation intensity is best governed by the ratio between jet and freestream velocity for varying oscillator spacing. For a flap angle of 20°, the smallest net drag is obtained at a velocity ratio of 4.5. Furthermore, the optimal velocity ratio for the most efficient drag reduction changes linearly with flap angle. Smaller flap deflections require a smaller velocity ratio for optimal control at different oscillator spacing. A net drag reduction of about 13 % is measured at a flap angle of 20° when the drag is corrected by the momentum input. Even if the measured drag is conservatively corrected by the energy coefficient, a net improvement of 7 % is achieved. For the current setup, the most efficient drag reduction is still obtained at smaller flap angles with a lower momentum input. However, the presented results support the general feasibility of this drag reduction approach with significant room left for optimization.

  10. Mixing enhancement of jets and drag reduction in manipulated bluff body wakes

    NASA Astrophysics Data System (ADS)

    Arcas, Diego Rodriguez

    In the first part of this work a direct numerical simulation of the approach is employed in the study of a planar jet immersed in a co-flowing stream. An aerodynamic vectoring effect on the jet is achieved by the application of asymmetrically distributed suction at the lips of the exit nozzle. An optimal suction distribution for maximum lift generation is located and used in conjunction with time-dependent stimulation to enhance the mixing characteristics of the jet. The dynamic behavior of the system in the phase plane is explored and a regime of suction parameters for maximum mixing enhancement is revealed. The attractor selection sensitivity to initial conditions of the system is also investigated. The second part of this dissertation used direct numerical simulation in the study of the flow dynamics in the near wake of a two dimensional rectangular bluff body. The suppression of the global mode of instability via base suction or bleed is investigated and the ventilation coefficient cvent , a non-dimensional measure of the ventilation mass flux, is identified as a major scaling parameter in the determination of the structural characteristics and suppression of the global mode of via base bleed. Aerodynamic drag reduction is pursued by modifying the base pressure component of the drag. Boat-tails (blocks and plates) are attached at the trailing edge of the rectangular forebody and an optimal aspect ratio for boat-tail notches at the separation point is identified. The use of boat-tailing in conjunction with base bleed is also investigated and the common underlying mechanism leading to elevated base pressure in different configurations is revealed.

  11. Long-term benthic monitoring programs near the Morgantown and Calvert Cliffs power plants - annual report for the first year's studies. Volume III: appendices A-E. Report for Jul 80-Jun 81

    SciTech Connect

    Holland, A.F.; Hiegel, M.H.; Fisher, K.; Hoffman, H.; Johnson, G.F.

    1982-04-01

    This volume contains the following appendices: summary of physical/chemical and sediment data collected between July 1980 and June 1981; Summaries of benthic community data for Calvert Cliffs and Morgantown long-term benthic studies; Summary of biomass data collected between July and December 1980; Summary of size-class distribution data collected for numerically dominant bivalves; and Summary of results of stepwise regression analysis.

  12. Environmental Assessment of the Gering-Stegall 115-kV Transmission Line Consolidation Project, Scotts Bluff County, Nebraska

    SciTech Connect

    1995-05-01

    The Department of Energy (DOE), Western Area Power Administration (Western) proposes to consolidate segments of two transmission lines near the Gering Substation in Gering, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska. The transmission lines are both located in Scotts Bluff County, Nebraska, within the city of Gering. Presently, there are three parallel 115-kilovolt (kV) transmission lines on separate rights-of-way (ROW) that terminate at the Gering Substation. The project would include dismantling the Archer-Gering wood-pole transmission line and rebuilding the remaining two lines on single-pole steel double circuit structures. The project would consolidate the Gering-Stegall North and Gering-Stegall South 115-kV transmission lines on to one ROW for a 1.33-mile segment between the Gering Substation and a point west of the Gering Landfill. All existing wood-pole H-frame structures would be removed, and the Gering-Stegall North and South ROWs abandoned. Western is responsible for the design, construction, operation, and maintenance of the line. Western prepared an environmental assessment (EA) that analyzed the potential environmental impacts of the proposed construction, operation, and maintenance of the 115-kV transmission line consolidation. Based on the analyses in the EA, the DOE finds that the proposed action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act of 1969 (NEPA).

  13. Transfer function characteristics of bluff-body stabilized, conical V-shaped premixed turbulent propane-air flames

    SciTech Connect

    Chaparro, Andres; Landry, Eric; Cetegen, Baki M.

    2006-04-15

    The response of bluff-body stabilized conical V-shaped premixed flames to periodic upstream velocity oscillations was characterized as a function of oscillation frequency, mean flow velocity, and equivalence ratio. The flame heat release response to the imposed velocity oscillations was determined from the CH* chemiluminescence captured by two photomultiplier (PMT) detectors at a wavelength of 430 nm. One of the PMTs viewed flame radiation in a 10-mm horizontal slice, 50 mm above the bluff-body. The second PMT observed the overall flame radiation. The flame transfer function characteristics were determined from the spectral analysis of the velocity and PMT signals. It was found that the flame heat release amplitude response is confined to low-frequency excitation below a Strouhal number of 4. The phase relationship of the transfer function for these turbulent flames was evaluated using the signal from the spatially masked PMT. The transfer function estimate based on these data exhibits second-order characteristics with a phase lag between the velocity and heat release signals. The localized heat-release response contains frequencies that are multiples of the excitation frequency, suggesting splitting and tilting of flame structures as well as some nonlinear effects. Increase of flame equivalence ratio from lean toward stoichiometric resulted in slight amplification of the high-frequency response. (author)

  14. The extraction and utilization of local and scientific geospatial knowledge within the Bluff oyster fishery, New Zealand.

    PubMed

    Hall, G Brent; Moore, Antoni; Knight, Peter; Hankey, Nick

    2009-05-01

    This paper assesses the Bluff oyster fishery in New Zealand as a case study in common pool resource management. It discusses ways in which modern information technology, augmented by low-tech data gathering strategies and community ethnography, can be used to produce an integrated scientific and local knowledge-inspired fishery database that lends itself to fostering collaboration in resource management and planning. The specific context and state of the oyster fishery in Bluff are described. Issues regarding undocumented and ephemeral intergenerational knowledge, much of which is geospatial in nature, on the fishery, the current crisis that many see in the future of the fishery, and a lack of cohesion or common sense of purpose between the stakeholder groups are discussed. It is argued that the digital resource that results from the integration of local and scientific knowledge and the potential community building processes that can ensue from collaboration and dialogue around this centrepiece are of central importance in developing an oyster fishery management plan that is holistic in concept and sustainable in purpose. PMID:18760525

  15. Modeling 3-D Slope Stability of Coastal Bluffs Using 3-D Ground-Water Flow, Southwestern Seattle, Washington

    USGS Publications Warehouse

    Brien, Dianne L.; Reid, Mark E.

    2007-01-01

    Landslides are a common problem on coastal bluffs throughout the world. Along the coastal bluffs of the Puget Sound in Seattle, Washington, landslides range from small, shallow failures to large, deep-seated landslides. Landslides of all types can pose hazards to human lives and property, but deep-seated landslides are of significant concern because their large areal extent can cause extensive property damage. Although many geomorphic processes shape the coastal bluffs of Seattle, we focus on large (greater than 3,000 m3), deepseated, rotational landslides that occur on the steep bluffs along Puget Sound. Many of these larger failures occur in advance outwash deposits of the Vashon Drift (Qva); some failures extend into the underlying Lawton Clay Member of the Vashon Drift (Qvlc). The slope stability of coastal bluffs is controlled by the interplay of three-dimensional (3-D) variations in gravitational stress, strength, and pore-water pressure. We assess 3-D slope-stability using SCOOPS (Reid and others, 2000), a computer program that allows us to search a high-resolution digital-elevation model (DEM) to quantify the relative stability of all parts of the landscape by computing the stability and volume of thousands of potential spherical failures. SCOOPS incorporates topography, 3-D strength variations, and 3-D pore pressures. Initially, we use our 3-D analysis methods to examine the effects of topography and geology by using heterogeneous material properties, as defined by stratigraphy, without pore pressures. In this scenario, the least-stable areas are located on the steepest slopes, commonly in Qva or Qvlc. However, these locations do not agree well with observations of deep-seated landslides. Historically, both shallow colluvial landslides and deep-seated landslides have been observed near the contact between Qva and Qvlc, and commonly occur in Qva. The low hydraulic conductivity of Qvlc impedes ground-water flow, resulting in elevated pore pressures at the base of Qva, thereby increasing the potential for landslides. Our analysis simulates the ground-water flow using the results of a 3-D ground-water flow model, MODFLOW-2000 (Harbaugh and others, 2000), to generate a 3-D pore-pressure field. Areas of elevated pore pressure reflect the influence of a perched ground-water table in Qva, as well as ground-water convergence in the coastal re-entrants. We obtain a realistic model of deep-seated landsliding by combining 3-D pore pressures with heterogeneous strength properties. The results show the least-stable areas where pore pressures are locally elevated in Qva. We compare our results with records of past landslides. The predicted leaststable areas include two historically active deep-seated landslides and areas adjacent to these landslides.

  16. Laboratory measurements of selected optical, physical, chemical, and remote-sensing properties of five water mixtures containing Calvert clay and a nonfluorescing dye

    NASA Technical Reports Server (NTRS)

    Usry, J. W.; Whitlock, C. H.; Poole, L. R.; Witte, W. G., Jr.

    1981-01-01

    Total suspended solids concentrations ranged from 6.1 ppm to 24.3 ppm and sizes ranged between 1.5 micrometers and 10 micrometers with the most frequently occurring size less than 2 micrometers. Iron concentration was less than 1 percent of the total suspended solids. Nonfluorescing dye concentrations of the two mixtures were 20 ppm and 40 ppm. Attenuation coefficient for the five mixtures ranged from 4.8/m to 21.3/m. Variations in volume scattering function with phase angle were typical. Variations in attenuation and absorption coefficient with wavelength were similar for the mixtures without the dye. Attenuation coefficient of the mixtures with the dye increased for wavelengths less than 600 nm due to the dye's strong absorption peak near 500 nm. Reflectance increased as the concentration of Calvert clay increased and peaked near 600 nm. The nonfluorescent dye decreased the magnitude of the peak, but had practically no effect on the variation for wavelengths greater than 640 nm. At wavelengths less than 600 nm, the spectral variations of the mixtures with the dye were significantly different from those mixtures without the dye.

  17. Vortex dynamics and scalar transport in the wake of a bluff body driven through a steady recirculating flow

    NASA Astrophysics Data System (ADS)

    Poussou, Stephane B.; Plesniak, Michael W.

    2012-09-01

    The air ventilation system in wide-body aircraft cabins provides passengers with a healthy breathing environment. In recent years, the increase in global air traffic has amplified contamination risks by airborne flu-like diseases and terrorist threats involving the onboard release of noxious materials. In particular, passengers moving through a ventilated cabin may transport infectious pathogens in their wake. This paper presents an experimental investigation of the wake produced by a bluff body driven through a steady recirculating flow. Data were obtained in a water facility using particle image velocimetry and planar laser induced fluorescence. Ventilation attenuated the downward convection of counter-rotating vortices produced near the free-end corners of the body and decoupled the downwash mechanism from forward entrainment, creating stagnant contaminant regions.

  18. An Experimental Study on Base Pressure Correction for Bluff-Base Bodies Using Magnetic Suspension and Balance System

    NASA Astrophysics Data System (ADS)

    Tadakuma, Kenji; Aso, Shigeru; Tani, Yasuhiro; Mizoguchi, Yasushi; Okada, Takumi

    An experimental study on validity and improvement of base pressure correction for a bluff-base body with hemisphere nose using MSBS (Magnetic Suspension and Balance System) has been conducted. Force and pressure distribution data on the model base were examined for several parameters; angles of attack 0 7.5º, Reynolds number ReD=7.6×104, with or without a sting and diameters of the sting. These results showed that the base pressure correction using the pressure data near the sting could have validity at the case of 0º of angle of attack only. Besides we could propose a new accurate method to calculate base-pressure axis forces.

  19. Reconnaissance of Acid Drainage Sources and Preliminary Evaluation of Remedial Alternatives at the Copper Bluff Mine, Hoopa Valley Reservation, California

    USGS Publications Warehouse

    Alpers, Charles N.; Hunerlach, Michael P.; Hamlin, Scott N.; Zierenberg, Robert A.

    2003-01-01

    Acidic drainage from the inactive Copper Bluff mine cascades down a steep embankment into the Trinity River, on the Hoopa Valley Reservation in northern California. The Copper Bluff mine produced about 100,000 tons of sulfide-bearing copper-zinc-gold-silver ore during 1957?1962. This report summarizes the results of a water-resources investigation begun by the U.S. Geological Survey in 1994 with the overall objective of gathering sufficient geochemical, hydrologic, and geologic information so that a sound remediation strategy for the Copper Bluff mine could be selected and implemented by the Hoopa Valley Tribe. This study had the following specific objectives: (1) monitor the quality and quantity of the mine discharge, (2) determine seasonal variability of metal concentrations and loads, (3) map and sample the underground mine workings to determine sources of flow and suitability of mine plugging options, and (4) analyze the likely consequences of various remediation and treatment options. Analysis of weekly water samples of adit discharge over parts of two wet seasons (January to July 1995 and October 1995 to May 1996) shows that dissolved copper (Cu) and zinc (Zn) concentrations (in samples filtered with 0.20-micrometer membranes) varied systematically in a seasonal pattern. Metal concentrations increased dramatically in response to the first increase in discharge, or first flush, early in the wet season. The value of Zn/Cu in the adit discharge exhibited systematic seasonal variations; an annual Zn/Cu cycle was observed, beginning with values between 3 and 5 during the main part of the wet season, rising to values between 6 and 10 during the period of lowest discharge late in the dry season, and then dropping dramatically to values less than 3 during the first-flush period. Values of pH were fairly constant in the range of 3.1 to 3.8 throughout the wet season and into the beginning of the dry season, but rose to values between 4.5 and 5.6 during the period of lowest discharge, from October to early December 1995. Underground reconnaissance was conducted once during dry-season conditions (September 1995) and twice during wet-season conditions (March 1995 and March 1996). The main tunnel was accessed to a distance of about 600 feet from the portal entrance. Water samples were collected at nine locations along the floor of the main tunnel and from several ore shoots to evaluate the contributions of water and dissolved constituents from different portions of the mine. Values of pH ranged from 2.5 to 6.4 at different underground locations, concentrations of copper ranged from 0.020 to 44 mg/L (milligram per liter), zinc from 6.3 to 160 mg/L, and cadmium from 0.010 to 0.47 mg/L. Discharge from the ore shoots ranged from less than 1 gallon per minute to more than 30 gallons per minute and was always a small component of the total mine flow compared with the tunnel floor drainage. During March 1996, the main flow originated in the northernmost portion of the underground workings (inaccessible) and mixed with an unknown quantity of water upwelling from flooded lower workings. High-water marks observed on the tunnel walls indicate that past blockages impounded more than 100,000 gallons of water. Sudden release of a large volume of metal-rich water could have serious effects on fish and other aquatic resources in the Trinity River. Because of the hydrogeologic setting, mine plugging is not likely to offer an effective long-term solution to the problem of acid mine drainage at the Copper Bluff mine. The underground workings are close to a state highway and underlie a 500-foot-high bluff with highly fractured rocks that seep during the wet season. Total plugging likely would result in additional uncontrolled seepage and could potentially destabilize the highway. Partial plugging to restrict flow during periods of highest discharge may provide benefits in terms of reduced risk of catastrophic release without the addi

  20. Analysis of river planforms in the New Madrid region and possible relations to tectonic warping across the loess bluffs and within the meander belt of the Mississippi River

    SciTech Connect

    Johnson, K.A.; Mayer, L. . Dept. of Geology)

    1993-03-01

    Stream channel planforms measured from such streams as the Hatchie (H), L'Anguille (LA), St. Francis, White (W) and Little Red (LR) rivers provide a way to study influences of topographic warping between the loess bluffs that bound the Mississippi river valley. Planforms are analyzed using sinuosity, Richardson analysis, and pattern. Pattern changes include transitions from braided to meandering and meandering to straight. Sinuosities of the W and LR rivers show a transition from low sinuosity, [1.3, 1.4] to higher sinuosity [2.6, 2.8], over a short distance, as they cross the bluffs from the uplands to the Western Lowlands. On the east, the Hatchie changes from a braided to meandering pattern upon crossing the bluffs. Its sinuosity varies from a low of about 1.4 to a high of 2.2, coincident with a marsh area. The LA river flows on the west side of Crowley's Ridge and is paralleled by the St. Francis river on the east. These rivers, with very different drainage areas and sinuosities, show matching meander bends at similar wavelengths along Crowley's Ridge. The bends are about 10 km in 1/2 wavelength suggesting some extraordinary influence on pattern perpendicular to the ridge. Richardson analysis indicates that features with a 1/2 wavelength of 2 km may control several rivers' bending patterns. These features are analyzed to determine their spatial relations with one another.

  1. Classification of gas-liquid flow patterns by the norm entropy of wavelet decomposed pressure fluctuations across a bluff body

    NASA Astrophysics Data System (ADS)

    Sun, Zhiqiang; Chen, Yanping; Gong, Hui

    2012-12-01

    Identification of gas-liquid flow patterns remains one of the paramount needs in multiphase flow metering. It is hardly possible to realize accurate measurement and control of parameters in a gas-liquid flow system without a clear understanding of its flow pattern. Here we explore the characterization of gas-liquid flow patterns using the norm entropy extracted from the wavelet decomposed pressure fluctuations across a bluff body. Experiments on air-water two-phase flow at ambient temperature and atmospheric pressure are carried out in the bubble, plug, slug and annular flow patterns. On the basis of the experimental results, two original flow-pattern maps are constructed: one is coordinated with the average norm entropy versus the total mass flow rate, and the other is the average norm entropy versus the volumetric void fraction. Verification tests demonstrate that the overall identification rates of the flow-pattern maps developed exceed 95%. This approach provides an effective and simple solution to the classification of gas-liquid flow patterns.

  2. Large Eddy Simulations of forced ignition of a non-premixed bluff-body methane flame with Conditional Moment Closure

    SciTech Connect

    Triantafyllidis, A.; Mastorakos, E.; Eggels, R.L.G.M.

    2009-12-15

    Large Eddy Simulations (LES) of forced ignition of a bluff-body stabilised non-premixed methane flame using the Conditional Moment Closure (CMC) turbulent combustion model have been performed. The aim is to investigate the feasibility of the use of CMC/LES for ignition problems and to examine which, if any, of the characteristics already observed in related experiments could be predicted. A three-dimensional formulation of the CMC equation was used with simple and detailed chemical mechanisms, and sparks with different parameters (location, size) were used. It was found that the correct pattern of flame expansion and overall flame appearance were predicted with reasonable accuracy with both mechanisms, but the detailed mechanism resulted in expansion rates closer to the experiment. Moreover, the distribution of OH was predicted qualitatively accurately, with patches of high and low concentration in the recirculation zone during the ignition transient, consistent with experimental data. The location of the spark relative to the recirculation zone was found to determine the pattern of the flame propagation and the total time for the flame stabilisation. The size was also an important parameter, since it was found that the flame extinguishes when the spark is very small, in agreement with expectations from experiment. The stabilisation mechanism of the flame was dominated by the convection and sub-grid scale diffusion of hot combustion products from the recirculation zone to the cold gases that enter the burner, as revealed by analysis of the CMC equation. (author)

  3. Monitoring of populations and productivity of seabirds at St. George Island, Cape Peirce, and Bluff, Alaska, 1989. Final report

    SciTech Connect

    Mendenhall, V.M.

    1991-04-01

    In recent years, although descriptive studies have continued, the emphasis on population monitoring of seabirds has increased. Commercial uses of the Continental Shelf of the Bering and Chukchi Seas, including oil and gas development, subsurface placer mining, and commercial fishing, carry the potential for adverse pressures on seabird populations. Populations and productivity of seabirds were monitored in 1989 at three Bering Sea colonies: St. George, Cape Peirce, and Bluff. Murres and black-legged kittiwakes were monitored at all colonies to facilitate intercolony comparisons. These species were selected because they are relatively easy to study, numerous, sensitive to potential impacts of development, and widely distributed. Red legged kittiwakes also were monitored at St. George because of concern for the world status of the species. Methods were standardized among the three colonies to facilitate comparisons among colonies and years. Observations of productivity began at the time nests were established and continued until most young had fledged. Kittiwake nests and murre breeding sites used for estimation of productivity were mapped on photographs or sketches and the fate of each was recorded.

  4. Experimental investigations into the nature of airflows near Bluff bodies with aspiration, with implications to aerosol sampling

    NASA Astrophysics Data System (ADS)

    Sreenath, Avula; Ramachandran, Gurumurthy; Vincent, James H.

    The research described in this paper was stimulated by the need to understand better the nature of air flow around aerosol samplers of the type widely used in environmental and industrial hygiene. It deals with the application of visualisation techniques to determine the location of stagnation points for air flow about simple two- and three-dimensional bluff bodies (cylinder and sphere, respectively) for the case where there is aspiration of air (i.e. suction) from a point on the body surface. The effect of orientation of the sampling orifice (or sink) with respect to the free stream on the location of stagnation points was compared with theoretical predictions using potential flow models. Good agreement was obtained, even for large angles with respect to the wind. For the two-dimensional cylindrical body, we also experimentally investigated the frequency of the vortex shedding in its near wake and how that is influenced by the aspiration. As represented by the dimensionless Strouhal number, this was found to be strongly dependent on the aspiration flow rate and the slot orientation. The results may be explained qualitatively in terms of the effect of aspiration on the development of the boundary layer over the cylinder surface.

  5. Paleoenvironment of the Ogallala (Neogene) Formation in west-central Kansas

    SciTech Connect

    Twiss, P.C.; McCahon, T.J.; Oviatt, C.G. . Geology Dept.)

    1993-02-01

    At Lake Scott (Scott County) in west-central Kansas, the Ogallala Formation unconformably overlies the Niobrara Formation (Cretaceous) and forms the bluffs of the north-trending Ladder Creek valley. Two sections (Devil's Backbone, 23 m thick; Suicide Bluff, 45 m thick) contain fluvial sands that grade upward into probable eolian sands. The lower sections contain poorly cemented, moderately sorted, arkosic sand, some mud gravel, and poorly defined fluvial channels. In the lower part of Devil's Backbone, cross-bedded sand is capped by mud drapes. At Suicide Bluff, beds of cross-bedded and better sorted sand occur high in the section. Paleosols and secondary calcite and opal dominate the sections. Pedogenic calcretes with more than 52% CaCO[sub 3] are especially abundant and range up to morphologic Stage VI. The [delta][sup 13]C and [delta][sup 18]O in the calcretes range from [minus]4.8 to [minus]6.5 and [minus]8.2 to [minus]6.7 per mil (PDB), respectively. Opal-A has replaced most rhizoliths of the Ogallala. Silicified fossil seeds (Celtis sp., Biorbia sp.) and probable fossil mammal burrows also occur in the sections. Rhyolitic tephra, about 10 Ma, occurs 12 m below the calcrete caprock of Suicide Bluff. A massive layer of opal occurs about 8 m above the tephra and below a diatomaceous bed. Siliceous cement occurs throughout each section, possibly originating from opal phytoliths, tephra, and/or diatoms. These sections afford the potential for understanding the stratigraphic succession and paleoclimate during the late Miocene to possibly early Pliocene in the central High Plains region.

  6. Blowoff characteristics of bluff-body stabilized conical premixed flames with upstream spatial mixture gradients and velocity oscillations

    SciTech Connect

    Chaudhuri, Swetaprovo; Cetegen, Baki M.

    2008-06-15

    This experimental study concerns determination of blowoff equivalence ratios for lean premixed conical flames for different mixture approach velocities ranging from 5 to 16 m/s in the presence of spatial mixture gradients and upstream velocity modulation. Conical flames were anchored on a disk-shaped bluff body that was attached to a central rod in the burner nozzle. A combustible propane-air mixture flowed through a converging axisymmetric nozzle with a concentric insert, allowing radial mixture variation by tailoring the composition in the inner and outer parts of the nozzle. The radial mixture profiles were characterized near the location of the flame holder by laser Rayleigh light scattering. Additionally, a loudspeaker at the nozzle base allowed introduction of periodic velocity oscillations with an amplitude of 9% of the mean flow velocity up to a frequency of 350 Hz. The flame blowoff equivalence ratio was experimentally determined by continuously lowering the fuel flow rates and determining the flame detachment point from the flame holder. Flame detachment was detected by a rapid reduction of CH* emission from the flame base imaged by a photomultiplier detector. It was found that the flame blowoff is preceded by progressive narrowing of the flame cone for the case of higher inner jet equivalence ratios. In this case, the fuel-lean outer flow cannot sustain combustion, and clearly this is not a good way of operating a combustor. Nevertheless, the overall blowoff equivalence ratio is reduced by inner stream fuel enrichment. A possible explanation for this behavior is given based on the radial extent of the variable-equivalence-ratio mixture burning near the flame stabilization region. Fuel enrichment in the outer flow was found to have no effect on blowoff as compared to the case of uniform mixture. The results were similar for the whole range of mean flow velocities and upstream excitation frequencies. (author)

  7. Chronostratigraphy and biostratigraphy of Paleogene Formations in eastern Gulf Coastal Province

    SciTech Connect

    Siesser, W.G.

    1985-02-01

    Paleogene formations extending from eastern Alabama to Arkansas have been assigned to internationally recognized biostratigraphic zones based on calcareous nannoplankton fossils. All zones from NP 1 to NP 24 are present in the study area, with the exception of NP 11 (within the early Eocene) and NP 23 (within the early Oligocene). Gulf Coast formations correlate to international standard chronostratigraphic stages as follows. The Clayton and Porters Creek formations correlate to the Danian Stage. The Naheola Formation, Salt Mountain Limestone, Nanafalia Formation, Tuscahoma Sand, and lower Hatchetigbee Formation (in part) correlate to the Selandian Stage. The Hatchetigbee (in part) and lower Tallahatta correlate to the Ypresian Stage; the upper Tallahatta and most of the Lisbon and Cook Mountain Formations correlate to the Lutetian Stage. The upper Lisbon and Cook Mountain formations, the Gosport Sand, Moodys Branch, and lowermost Yazoo formations correlate to the Bartonian Stage. The Crystal River and most of the Yazoo Formation correlate to the Priabonian Stage. The uppermost Yazoo Formation, the Bumpnose Limestone, Red Bluff, Forest Hill, and Mint Spring Formations, Marianna and Glendon Limestones, and Byram and Bucatunna Formations correlate to the Rupelian Stage. The Chickasawhay Limestone and Paynes Hammock Formation span the Rupelian-Chattian boundary. The Paleocene-Eocene boundary (approximately the NP 9-NP 10 boundary) is therefore within the lower Hatchetigbee Formation (Bashi Marl Member). The Eocene-Oligocene boundary (within lowermost NP 21) is within the uppermost Yazoo Formation (Shubuta Clay Member) in places, and within the lowermost Bumpnose, Red Bluff, and Forest Hill Formations and Marianna Limestone elsewhere in the region.

  8. Interglacial Extension of the Boreal Forest Limit in the Noatak Valley, Northwest Alaska: Evidence from an Exhumed River-Cut Bluff and Debris Apron

    USGS Publications Warehouse

    Edwards, M.E.; Hamilton, T.D.; Elias, S.A.; Bigelow, N.H.; Krumhardt, A.P.

    2003-01-01

    Numerous exposures of Pleistocene sediments occur in the Noatak basin, which extends for 130 km along the Noatak River in northwestern Alaska. Nk-37, an extensive bluff exposure near the west end of the basin, contains a record of at least three glacial advances separated by interglacial and interstadial deposits. An ancient river-cut bluff and associated debris apron is exposed in profile through the central part of Nk-37. The debris apron contains a rich biotic record and represents part of an interglaciation that is probably assignable to marine-isotope stage 5. Pollen spectra from the lower part of the debris apron closely resemble modern samples taken from the Noatak floodplain in spruce gallery forest, and macrofossils of spruce are also present at this level. Fossil bark beetles and carpenter ants occur higher in the debris apron. Mutual Climatic Range (MCR) estimates from the fossil beetles suggest temperatures similar to or warmer than today. Together, these fossils indicate the presence of an interglacial spruce forest in the western part of the Noatak Basin, which lies about 80 km upstream of the modern limit of spruce forest.

  9. Water-resources appraisal of the Camp Swift lignite area, central Texas

    USGS Publications Warehouse

    Gaylord, J.L.; Slade, R.M.; Ruiz, L.M.; Welborn, C.T.; Baker, E.T.

    1985-01-01

    The Camp Swift area, Texas was studied to describe the hydrogeology and to provide baseline data of the groundwater and surface water resources that would be affected by the strip mining of lignite. The investigation was centered on the 18-square mile Camp Swift Military Reservation where a reported 80 to 100 million short tons of commercially mineable lignite occurs within 200 feet of the land surface. Groundwater data showed that water levels in observation wells changed only slightly and that the water quality in the Calvert Bluff Formation, which contains the lignite, and in the Simsboro Formation, which is the major aquifer beneath the Calvert Bluff, is suitable for most uses. Big Sandy Creek, which crosses Camp Swift generally has a base flow of less than 0.5 cu ft/sec and infrequently is dry. Dogwood Creek, which originates on Camp Swift, usually is dry. The flow of both streams changes rapidly in response to rainfall in the watersheds. The quality of the water in both streams generally is suitable for most uses. A lithologic examination of 255 feet of cored section that represents the overburden and the lignite showed cyclic layering of fine sand, silt, clay, and lignite. Chemical analyses indicate that the pyritic sulfur concentration is small but variable. (USGS)

  10. Scotts Bluff folio, Nebraska 

    E-print Network

    Darton, Nelson Horatio, 1865-1948.

    1903-01-01

    erosion at Lake Sharpe were observed in the field and correlated to bank geology. Active processes of erosion observed included: slump, block slide, debris flow, toppling, slaking, and gullying. Each process was unique to the physical properties...

  11. The Knowledge Bluff

    ERIC Educational Resources Information Center

    Vanderburg, Willem H.

    2007-01-01

    Our knowledge "system" is built up from disciplines and specialties as its components, which are "wired" by patterns of collaboration that constitute its organization. The intellectual autonomy of these components prevents this knowledge system from adequately accounting for what we have gradually discovered during the past 50 years: In human…

  12. Forced sea-level change in a forearc basin related to subduction of a spreading ridge: the Fossil Bluff Group (Jurassic-Cretaceous), Alexander Island, Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Macdonald, David

    2015-04-01

    During the Mesozoic, the Antarctic Peninsula was the site of an active volcanic arc related to the eastwards subduction of proto-Pacific oceanic crust. Alexander Island is the largest of the many islands that lie on the western (fore-arc) side of the Antarctic Peninsula; it forms one of the best-exposed ancient fore-arcs in the world. The pre-Tertiary rocks can be divided into two main units. The LeMay Group (Jurassic-Tertiary) forms the structural basement to Alexander Island and comprises greenschist-facies metasedimentary rocks. It is interpreted as a Mesozoic accretionary prism. The Fossil Bluff Group unconformably overlies and is faulted against the LeMay Group; it represents the sedimentary fill of a coeval fore-arc basin. Subduction ceased due to a series of Cenozoic ridge-trench collisions which began off Alexander Island at 50 Ma and got progressively younger to the north. However, the approach of the ridge can be inferred from the Mesozoic deposits of the Fossil Bluff Group (Jurassic-Cretaceous) in Alexander Island. In this paper, I will show that the ocean floor being subducted became progressively shallower through Jurassic and Cretaceous time (by at least 1,000 m). The result in the forearc basin was a sudden shallowing in water depths from at least 1,000 m at 125 Ma, to emergent at 100 Ma. This forced shallowing ended sedimentation in the basin and resulted in considerable topography on Alexander Island that persists to the present day.

  13. Concept Formation Concept Formation

    E-print Network

    Goldstone, Robert

    Concept Formation 1 Concept Formation Robert L. Goldstone Thomas T. Hills Samuel B. Day Indiana, IN. 47408 Other Correspondences: rgoldsto@indiana.edu (812) 855-4853 Keywords: Concepts, Learning, Representation, Prototypes, Exemplars #12;Concept Formation 2 Concept Formation A concept is a mentally possessed

  14. Superfund Record of Decision (EPA Region 7): Mid-America Tanning site, Sergeant bBluff, IA. (First remedial action), September 1991

    SciTech Connect

    Not Available

    1991-09-24

    The 98.7-acre Mid-America Tanning site is a former leather tannery in Sergeant Bluff, Woodbury County, Iowa. Surrounding land use is mixed industrial and agricultural. A portion of the site is bordered by Oxbow Lake and lies within the 100-year floodplain. The Missouri River is approximately 1.5 miles to the southwest of the site and receives discharges from Oxbow Lake. The facility began onsite processing of animal hides in 1970. In 1980, the State confirmed the onsite burial of chromium-containing sludge in trenches, and the company was cited for permit violations. A 1985 EPA investigation identified excessive chromium contamination in onsite soil, sediment, and ground water. In 1990, EPA conducted a removal action that included excavating and consolidating onsite 1,290 cubic yards of sludge from the trench disposal area. The Record of Decision (ROD) addresses the contaminated soil, impoundment sediment and water, and the excavated trench material. A future ROD will address onsite ground water contamination. The primary contaminant of concern affecting the soil, sediment, debris, sludge, and surface water are metals including chromium and lead. The selected remedial action for the site is included.

  15. Preliminary Image Map of the 2007 Ammo Fire Perimeter, San Onofre Bluff Quadrangle, San Diego County, California

    USGS Publications Warehouse

    Clark, Perry S.; Scratch, Wendy S.; Bias, Gaylord W.; Stander, Gregory B.; Sexton, Jenne L.; Krawczak, Bridgette J.

    2008-01-01

    In the fall of 2007, wildfires burned out of control in southern California. The extent of these fires encompassed large geographic areas that included a variety of landscapes from urban to wilderness. The U.S. Geological Survey National Geospatial Technical Operations Center (NGTOC) is currently (2008) developing a quadrangle-based 1:24,000-scale image map product. One of the concepts behind the image map product is to provide an updated map in electronic format to assist with emergency response. This image map is one of 55 preliminary image map quadrangles covering the areas burned by the southern California wildfires. Each map is a layered, geo-registered Portable Document Format (.pdf) file. For more information about the layered geo-registered .pdf, see the readme file (http://pubs.usgs.gov/of/2008/1029/downloads/CA_Agua_Dulce_of2008-1029_README.txt). To view the areas affected and the quadrangles mapped in this preliminary project, see the map index (http://pubs.usgs.gov/of/2008/1029/downloads/CA_of2008_1029-1083_index.pdf) provided with this report.

  16. Habitat quality and recruitment success of cui-ui in the Truckee River downstream of Marble Bluff Dam, Pyramid Lake, Nevada

    USGS Publications Warehouse

    Scoppettone, G. Gary; Rissler, Peter H.; Salgado, J. Antonio; Harry, Beverly

    2013-01-01

    We compared cui-ui (Chasmistes cujus) recruitment from two reaches of the Truckee River with histories of severe erosional downcutting caused by a decline in Pyramid Lake surface elevation. In 1975, Marble Bluff Dam (MBD) was constructed 5 kilometers upstream of the extant mouth of the Truckee River to stabilize the upstream reach of the river; the downstream reach of the river remained unstable and consequently unsuitable for cui-ui recruitment. By the early 2000s, there was a decrease in the Truckee River’s slope from MBD to Pyramid Lake after a series of wet years in the 1990s. This was followed by changes in river morphology and erosion abatement. These changes led to the question as to cui-ui recruitment potential in the Truckee River downstream of MBD. In 2012, more than 7,000 cui-ui spawners were passed upstream of MBD, although an indeterminate number of cui-ui spawned downstream of MBD. In this study, we compared cui-ui recruitment upstream and downstream of MBD during a Truckee River low-flow year (2012). Cui-ui larvae emigration to Pyramid Lake began earlier and ended later downstream of MBD. A greater number of cui-ui larvae was produced downstream of MBD than upstream. This also was true for native Tahoe sucker (Catostomus tahoensis) and Lahontan redside (Richardsonius egregius). The improved Truckee River stability downstream of MBD and concomitant cui-ui recruitment success is attributed to a rise in Pyramid Lake's surface elevation. A decline in lake elevation may lead to a shift in stream morphology and substrate composition to the detriment of cui-ui reproductive success as well as the reproductive success of other native fishes.

  17. Quaternary geology of the Duck Hawk Bluffs, southwest Banks Island, Arctic Canada: a re-investigation of a critical terrestrial type locality for glacial and interglacial events bordering the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Evans, David J. A.; England, John H.; La Farge, Catherine; Coulthard, Roy D.; Lakeman, Thomas R.; Vaughan, Jessica M.

    2014-05-01

    Duck Hawk Bluffs, southwest Banks Island, is a primary section (8 km long and 60 m high) in the western Canadian Arctic Archipelago exposing a long record of Quaternary sedimentation adjacent to the Arctic Ocean. A reinvestigation of Duck Hawk Bluffs demonstrates that it is a previously unrecognized thrust-block moraine emplaced from the northeast by Laurentide ice. Previous stratigraphic models of Duck Hawk Bluffs reported a basal unit of preglacial fluvial sand and gravel (Beaufort Fm, forested Arctic), overlain by a succession of three glaciations and at least two interglacials. Our observations dismiss the occurrence of preglacial sediments and amalgamate the entire record into three glacial intervals and one prominent interglacial. The first glacigenic sedimentation is recorded by an ice-contact sandur containing redeposited allochthonous organics previously assigned to the Beaufort Fm. This is overlain by fine-grained sediments with ice wedge pseudomorphs and well-preserved bryophyte assemblages corresponding to an interglacial environment similar to modern. The second glacial interval is recorded by ice-proximal mass flows and marine rhythmites that were glacitectonized when Laurentide ice overrode the site from Amundsen Gulf to the south. Sediments of this interval have been reported to be magnetically reversed (>780 ka). The third interval of glacigenic sedimentation includes glacifluvial sand and gravel recording the arrival of Laurentide ice that overrode the site from the northeast (island interior) depositing a glacitectonite and constructing the thrust block moraine that comprises Duck Hawk Bluffs. Sediments of this interval have been reported to be magnetically normal (<780 ka). The glacitectonite contains a highly deformed melange of pre-existing sediments that were previously assigned to several formally named, marine and interglacial deposits resting in an undeformed sequence. In contrast, the tectonism associated with the thrust block moraine imparted pervasive deformation throughout all underlying units, highlighted by a previously unrecognized raft of Cretaceous bedrock. During this advance, Laurentide ice from the interior of Banks Island coalesced with an ice stream in Amundsen Gulf, depositing the interlobate Sachs Moraine that contains shells as young as ˜24 cal ka BP (Late Wisconsinan). During deglaciation, meltwater emanating from these separating ice lobes deposited outwash that extended to deglacial marine limit (11 m asl) along the west coast of Banks Island. Our new stratigraphic synthesis fundamentally revises and simplifies the record of past Quaternary environments preserved on southwest Banks Island, which serves as a key terrestrial archive for palaeoenvironmental change.

  18. A study of three-dimensional aspects of vortex shedding from a bluff body with a mild geometric disturbance

    NASA Astrophysics Data System (ADS)

    Tombazis, N.; Bearman, P. W.

    1997-01-01

    Experiments have been carried out to study the three-dimensional characteristics of vortex shedding from a half-ellipse shape with a blunt trailing edge. In order to control the occurrence of vortex dislocations, the trailing edges of the models used were constructed with a series of periodic waves across their spans. Flow visualization was carried out in a water tunnel at a Reynolds number of 2500, based on trailing-edge thickness. A number of shedding modes were observed and the sequence of mode transitions recorded. Quantitative data were obtained from wind tunnel measurements performed at a Reynolds number of 40000. Two shedding frequencies were recorded with the higher frequency occurring at spanwise positions coinciding with minima in the chord. At these same positions the base pressure was lowest and the vortex formation length longest. Arguments are put forward to explain these observations. It is shown that the concept of a universal Strouhal number holds, even when the flow is three-dimensional. The spanwise variation in time-average base pressure is predicted using the estimated amount of time the flow spends at the two shedding frequencies.

  19. Sequential palynostratigraphy of the Queen City and Weches formations (Middle Eocene Claiborne Group), southeast central Texas

    SciTech Connect

    Elsik, W.C. )

    1993-02-01

    Palynomorph sequences of several orders of magnitude were found in the Queen City and Weches formations respectively at Six Mile and Burleson bluffs on the Brazos River, Milam and Burleson counties, Texas. The long term development of the subtropical to tropical Claibornian palynoflora included Engelhardtia spp., Friedrichipollis claibornensis, Nudopollis terminalis, Pollenites laesius and Symplocoipollenites spp. Shorter term fluctuations in sea level were reflected by common herbaceous pollen in the Queen City, and common mangrove pollen in the Weches. Paleoenvironments were marginally to fully marine; dinocysts occurred throughout. The Wetzeliella group of dinocysts were present only in the Queen City at Six Mile Bluff. Late Paleocene to Early Eocene pollen, and Early Middle Eocene pollen with last effective occurrences near the Queen City and Weches boundary included Aesculiidites circumstriatus, Annona foveoreticulata and a new species of Platycarya. Five short term warmer-cooler couplet events were represented by successive abundance peaks of Juglandaceae followed by Ulmus; Alnus supports the three upper Ulmus peaks. One deep water event was recorded by an abundance of fresh water Pediastrum at the Queen City and Weches boundary. That boundary event was bracketed by two of the Alnus and Ulmus peaks.

  20. Effective Categoricity of Equivalence Structures Wesley Calvert

    E-print Network

    Harizanov, Valentina S.

    Department of Mathematics George Washington University Washington, DC 20052 harizanv@gwu.edu Andrei Morozov acknowledge the support of the Columbian Research Fellowship of the George Washington University. 1 #12

  1. Smart Pricing Grows the Pie Guy Calvert

    E-print Network

    Cortes, Corinna

    , networks allow businesses to advertise on many publisher websites - big and small ­ with relatively little and networks stand to make more revenue as well. 1 Introduction Internet website advertising is big business such features involve discounting advertiser bids or prices for clicks on publisher websites according to how

  2. Bluff and Bull in Education

    ERIC Educational Resources Information Center

    Sassoon, David

    2005-01-01

    Telling a lie, according to Harry G. Frankfurt, is different from engaging in bullshit because, while a lie is designed to insert a particular falsehood at a specific point in a set or system of beliefs in order to avoid the consequences of having that occupied by truth, bullshit neither misrepresents the state of affairs to which it refers nor…

  3. High-resolution, paired geochemical-paleomagnetic stratigraphy of the Sentinel Bluffs Member of the Grande Ronde Basalt, Columbia River Basalt Group

    NASA Astrophysics Data System (ADS)

    Sawlan, M. G.; Hagstrum, J. T.

    2012-12-01

    The Sentinel Bluffs Member (SB) of the Grande Ronde Basalt (GRB) is the youngest stratigraphic unit of the GRB, and is distinguished from other lava flows within the GRB's upper normal polarity magnetozone (N2) by its relatively high MgO content. We collected co-located samples in SB lava flows for major and trace element (XRF) geochemical and paleomagnetic analyses from 7 stratigraphic sections in the central and eastern Columbia River Gorge, on the southwestern Columbia Plateau, at Sentinel Gap on the western Plateau, and at Patrick Grade in the northern Blue Mountains of eastern WA. For the Sentinel Gap section we have adopted the paleomagnetic data from Coe et al. [1978, Rockwell Hanford report RHO-BWI-ST-2], except for our sampling of the Levering flow (not previously sampled) and resampling of their SB flow "H". Paleomagnetic directions for SB flows define 7 stratigraphically controlled groups (I-VII) varying primarily in inclination. Groups I, III, and V have moderate inclinations (means of 55°-57°), groups II and IV have steeper inclinations (67°-69°), and groups VI and VII have the steepest inclinations (72°-78°). SB lava flows exhibit relatively large chemical variations, spanning nearly 1 wt% MgO. Within this span, we recognize 11 discrete chemical groups (1-11, numbered in stratigraphic order) mainly on the basis of TiO2-MgO variations. Early SB eruptions include low- and high-Cr subgroups, and chemical groups 1 and 2 (paleomagnetic groups I-III) are subdivided on the basis of a ~2x difference in Cr abundances (e.g., 16-20 ppm Cr in groups 1a and 2a, 32-38 ppm Cr in groups 1b and 2b). Low-Cr flows are observed only in the lower parts of the SB stratigraphy. Three group 1 (I-II) lava flows that are the lowest SB flows in three sections have similar major element abundances, but differ from each other either in trace element abundances and/or paleomagnetic direction. We infer that the earliest SB flows have moderate inclinations (56°) and include both low-Cr and hi-Cr flows. Systematic decreases in TiO2 and increases in MgO are observed within groups 1-5 (I-III) and 9-11 (VI-VII) with decreasing age. Having similar MgO values, the younger flows of groups 9-11 have distinctly lower TiO2 relative to groups 1-5. Chemical groups 6-8 (IV-V) have relatively high MgO (~4.9-5.2 wt%), intermediate TiO2, and somewhat higher Cr (40-46 ppm) relative to lava flows within groups 1-5 and 9-11 having similar MgO values. With one exception, observed breaks between geochemical and paleomagnetic groups are not contemporaneous as shifts in paleomagnetic direction apparently occurred during eruption of flows within a single chemical group. A total of 22 SB flows are defined by geochemistry and physical flow boundaries. Accounting for differences in paleomagnetic directions within the chemical groups, as many as 29 flows are represented. We attribute the high resolution of our geochemical data to rigorous sampling and lab preparation protocols that minimized alteration products in the material analyzed. Our combined geochemical and paleomagnetic data enables correlation of individual flows or small flow packages (i.e. 2-4 flows) from locations separated by as much as 200 km. These results implicate a high degree of chemical homogeneity within individual SB flows.

  4. Formation of lunar basin rings

    USGS Publications Warehouse

    Hodges, C.A.; Wilhelms, D.E.

    1978-01-01

    The origin of the multiple concentric rings that characterize lunar impact basins, and the probable depth and diameter of the transient crater have been widely debated. As an alternative to prevailing "megaterrace" hypotheses, we propose that the outer scarps or mountain rings that delineate the topographic rims of basins-the Cordilleran at Orientale, the Apennine at Imbrium, and the Altai at Nectaris-define the transient cavities, enlarged relatively little by slumping, and thus are analogous to the rim crests of craters like Copernicus; inner rings are uplifted rims of craters nested within the transient cavity. The magnitude of slumping that occurs on all scarps is insufficient to produce major inner rings from the outer. These conclusions are based largely on the observed gradational sequence in lunar central uplifts:. from simple peaks through somewhat annular clusters of peaks, peak and ring combinations and double ring basins, culminating in multiring structures that may also include peaks. In contrast, belts of slump terraces are not gradational with inner rings. Terrestrial analogs suggest two possible mechanisms for producing rings. In some cases, peaks may expand into rings as material is ejected from their cores, as apparently occurred at Gosses Bluff, Australia. A second process, differential excavation of lithologically diverse layers, has produced nested experimental craters and is, we suspect, instrumental in the formation of terrestrial ringed impact craters. Peak expansion could produce double-ring structures in homogeneous materials, but differential excavation is probably required to produce multiring and peak-in-ring configurations in large lunar impact structures. Our interpretation of the representative lunar multiring basin Orientale is consistent with formation of three rings in three layers detected seismically in part of the Moon-the Cordillera (basin-bounding) ring in the upper crust, the composite Montes Rook ring in the underlying, more coherent "heald" crust, and an innermost, 320-km ring at the crust-mantle interface. Depth-diameter ratios of 1 10to 1 15 are consistent with this interpretation and suggest that volumes of transient cavities and hence of basin ejecta may be considerably greater than commonly assumed. ?? 1978.

  5. CO2 Sequestration Potential of Texas Low-Rank Coals

    SciTech Connect

    Duane McVay; Walter Ayers, Jr.; Jerry Jensen; Jorge Garduno; Gonzola Hernandez; Rasheed Bello; Rahila Ramazanova

    2006-08-31

    Injection of CO{sub 2} in coalbeds is a plausible method of reducing atmospheric emissions of CO{sub 2}, and it can have the additional benefit of enhancing methane recovery from coal. Most previous studies have evaluated the merits of CO{sub 2} disposal in high-rank coals. The objective of this research was to determine the technical and economic feasibility of CO{sub 2} sequestration in, and enhanced coalbed methane (ECBM) recovery from, low-rank coals in the Texas Gulf Coast area. Our research included an extensive coal characterization program, including acquisition and analysis of coal core samples and well transient test data. We conducted deterministic and probabilistic reservoir simulation and economic studies to evaluate the effects of injectant fluid composition (pure CO{sub 2} and flue gas), well spacing, injection rate, and dewatering on CO{sub 2} sequestration and ECBM recovery in low-rank coals of the Calvert Bluff formation of the Texas Wilcox Group. Shallow and deep Calvert Bluff coals occur in two, distinct, coalbed gas petroleum systems that are separated by a transition zone. Calvert Bluff coals < 3,500 ft deep are part of a biogenic coalbed gas system. They have low gas content and are part of a freshwater aquifer. In contrast, Wilcox coals deeper than 3,500 ft are part of a thermogenic coalbed gas system. They have high gas content and are part of a saline aquifer. CO{sub 2} sequestration and ECBM projects in Calvert Bluff low-rank coals of East-Central Texas must be located in the deeper, unmineable coals, because shallow Wilcox coals are part of a protected freshwater aquifer. Probabilistic simulation of 100% CO{sub 2} injection into 20 feet of Calvert Bluff coal in an 80-acre 5-spot pattern indicates that these coals can store 1.27 to 2.25 Bcf of CO{sub 2} at depths of 6,200 ft, with an ECBM recovery of 0.48 to 0.85 Bcf. Simulation results of flue gas injection (87% N{sub 2}-13% CO{sub 2}) indicate that these same coals can store 0.34 to 0.59 Bcf of CO{sub 2} with an ECBM recovery of 0.68 to 1.20 Bcf. Economic modeling of CO{sub 2} sequestration and ECBM recovery indicates predominantly negative economic indicators for the reservoir depths (4,000 to 6,200 ft) and well spacings investigated, using natural gas prices ranging from $2 to $12 per Mscf and CO{sub 2} credits based on carbon market prices ranging from $0.05 to $1.58 per Mscf CO{sub 2} ($1.00 to $30.00 per ton CO{sub 2}). Injection of flue gas (87% N{sub 2} - 13% CO{sub 2}) results in better economic performance than injection of 100% CO{sub 2}. CO{sub 2} sequestration potential and methane resources in low-rank coals of the Lower Calvert Bluff formation in East-Central Texas are significant. The potential CO{sub 2} sequestration capacity of the coals ranges between 27.2 and 49.2 Tcf (1.57 and 2.69 billion tons), with a mean value of 38 Tcf (2.2 billion tons), assuming a 72.4% injection efficiency. Estimates of recoverable methane resources range between 6.3 and 13.6 Tcf, with a mean of 9.8 Tcf, assuming a 71.3% recovery factor. Moderate increases in gas prices and/or carbon credits could generate attractive economic conditions that, combined with the close proximity of many CO{sub 2} point sources near unmineable coalbeds, could enable commercial CO{sub 2} sequestration and ECBM projects in Texas low-rank coals. Additional studies are needed to characterize Wilcox regional methane coalbed gas systems and their boundaries, and to assess potential of other low-rank coal beds. Results from this study may be transferable to other low-rank coal formations and regions.

  6. Lithofacies of Spencer Formation, western Tualatin Valley, Oregon

    SciTech Connect

    Van Atta, R.O.

    1986-04-01

    The Spencer Formation crops out in a narrow band that trends north-northwest on the western edge of the Willamette and Tualatin Valleys, Oregon. It apparently conformably overlies mud rocks of either the Yamhill or the Nestucca Formation and is conformably overlain by the Pittsburgh Bluff Formation. The Spencer Formation consists of two members (informal): a lower highly micaceous sandstone (800-1000 ft) and an upper member that is micaceous siltstone and mudstone (1000-1300 ft). The lower member includes an upper part that is light-gray to creamy-gray, silty to muddy, pebbly lithic arkose to feldspathic litharenite, with minor arkose. Sorting is poor and beds may be laminated to ripple cross-laminated or massive and bioturbated with abundant mollusk shells, carbonized wood, and burrows. The lower part of the lower member is medium-gray to greenish-gray, silty, pumiceous lithic arkose to feldspathic litharenite. The texture tends to be more uniform and better sorted than that of the upper part of the member. Bedding is commonly massive due to bioturbation. The upper member is medium to dark-gray mudstone with thin pebble-conglomerate lenses. It intertongues with the lower member. Bioturbation, burrows, and carbonized wood are common. The trend in depositional environments appears to be from outer to mid-neritic (lower part, lower member) to shallow neritic, nearshore, and lagoonal (upper part, lower member, and upper member). The provenance of the Spencer Formation includes both proximal volcanics and distant plutonic and high-grade metamorphics.

  7. 40. December 20, 1933 View of portal site, tunnel no. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. December 20, 1933 View of portal site, tunnel no. 1, CWA men facing the portal. "Stripping the hillside grule sic formation between tunnels 1 and 2." - Scotts Bluff Summit Road, Gering, Scotts Bluff County, NE

  8. Planet formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    1993-01-01

    Models of planetary formation are developed using the present single example of a planetary system, supplemented by limited astrophysical observations of star-forming regions and circumstellar disks. The solar nebula theory and the planetesimal hypothesis are discussed. The latter is found to provide a viable theory of the growth of the terrestrial planets, the cores of the giant planets, and the smaller bodies present in the solar system. The formation of solid bodies of planetary size should be a common event, at least around young stars which do not have binary companions orbiting at planetary distances. Stochastic impacts of large bodies provide sufficient angular momentum to produce the obliquities of the planets. The masses and bulk compositions of the planets can be understood in a gross sense as resulting from planetary growth within a disk whose temperature and surface density decreased with distance from the growing sun.

  9. Amphiplex Formation

    NASA Astrophysics Data System (ADS)

    Petersen, Shannon; Laaser, Jennifer; Lodge, Timothy

    2015-03-01

    Polymer-micelle complexes are currently under heavy investigation due to their potential applications in targeted drug delivery and gene therapy, yet the dynamics of the complex formation is still relatively unstudied. By varying the ratios of poly(styrene sulfonate) chains and cationic poly(dimethylaminoethyl methacrylate)-b-poly(styrene) micelles and the ionic strength of the system, we created a variety of complex configurations of different sizes and charges. The complexes were characterized dynamic light scattering and zeta potential measurements which provided information regarding the hydrodynamic radius, distribution of sizes, and effective charge.

  10. Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Fonda, Mark (Technical Monitor)

    2002-01-01

    Modern theories of star and planet formation and of the orbital stability of planetary systems are described and used to discuss possible characteristics of undiscovered planetary systems. The most detailed models of planetary growth are based upon observations of planets and smaller bodies within our own Solar System and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. These models predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. A potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path. The implications of the giant planets found in recent radial velocity searches for the abundances of habitable planets are discussed, and the methods that are being used and planned for detecting and characterizing extrasolar planets are reviewed.

  11. CO2 SEQUESTRATION POTENTIAL OF TEXAS LOW-RANK COALS

    SciTech Connect

    Duane A. McVay; Walter B. Ayers Jr; Jerry L. Jensen

    2004-11-01

    The objectives of this project are to evaluate the feasibility of carbon dioxide (CO{sub 2}) sequestration in Texas low-rank coals and to determine the potential for enhanced coalbed methane (CBM) recovery as an added benefit of sequestration. there were two main objectives for this reporting period. first, they wanted to collect wilcox coal samples from depths similar to those of probable sequestration sites, with the objective of determining accurate parameters for reservoir model description and for reservoir simulation. The second objective was to pursue opportunities for determining permeability of deep Wilcox coal to use as additional, necessary data for modeling reservoir performance during CO{sub 2} sequestration and enhanced coalbed methane recovery. In mid-summer, Anadarko Petroleum Corporation agreed to allow the authors to collect Wilcox Group coal samples from a well that was to be drilled to the Austin Chalk, which is several thousand feet below the Wilcox. In addition, they agreed to allow them to perform permeability tests in coal beds in an existing shut-in well. Both wells are in the region of the Sam K. Seymour power station, a site that they earlier identified as a major point source of CO{sub 2}. They negotiated contracts for sidewall core collection and core analyses, and they began discussions with a service company to perform permeability testing. To collect sidewall core samples of the Wilcox coals, they made structure and isopach maps and cross sections to select coal beds and to determine their depths for coring. On September 29, 10 sidewall core samples were obtained from 3 coal beds of the Lower Calvert Bluff Formation of the Wilcox Group. The samples were desorbed in 4 sidewall core canisters. Desorbed gas samples were sent to a laboratory for gas compositional analyses, and the coal samples were sent to another laboratory to measure CO{sub 2}, CH{sub 4}, and N{sub 2} sorption isotherms. All analyses should be finished by the end of December. A preliminary report shows methane content values for the desorbed coal samples ranged between 330 and 388 scf/t., on ''as received'' basis. Residual gas content of the coals was not included in the analyses, which results in an approximate 5-10% underestimation of in-situ gas content. Coal maps indicate that total coal thickness is 40-70 ft in the Lower Calvert Bluff Formation of the Wilcox Group in the vicinity of the Sam K. Seymour power plant. A conservative estimate indicates that methane in place for a well on 160-acre spacing is approximately 3.5 Bcf in Lower Calvert Bluff coal beds. When they receive sorption isotherm data from the laboratory, they will determine the amount of CO{sub 2} that it may be possible to sequester in Wilcox coals. In December, when the final laboratory and field test data are available, they will complete the reservoir model and begin to simulate CO{sub 2} sequestration and enhanced CH{sub 4} production.

  12. P Formation

    NASA Astrophysics Data System (ADS)

    Yang, Ying; Balaraju, J. N.; Huang, Yizhong; Tay, Yee Yan; Shen, Yiqiang; Tsakadze, Zviad; Chen, Zhong

    2014-11-01

    The voids formed in the Ni3P layer during reaction between Sn-based solders and electroless Ni-P metallization is an important cause of rapid degradation of solder joint reliability. In this study, to suppress formation of the Ni3P phase, an electrolessly plated Ni-Sn-P alloy (6-7 wt.% P and 19-21 wt.% Sn) was developed to replace Ni-P. The interfacial microstructure of electroless Ni-Sn-P/Sn-3.5Ag solder joints was investigated after reflow and solid-state aging. For comparison, the interfacial reaction in electroless Ni-P/Sn-3.5Ag solder joints under the same reflow and aging conditions was studied. It was found that the Ni-Sn-P metallization is consumed much more slowly than the Ni-P metallization during soldering. After prolonged reaction, no Ni3P or voids are observed under SEM at the Ni-Sn-P/Sn-3.5Ag interface. Two main intermetallic compounds, Ni3Sn4 and Ni13Sn8P3, are formed during the soldering reaction. The reason for Ni3P phase suppression and the overall mechanisms of reaction at the Ni-Sn-P/Sn-3.5Ag interface are discussed.

  13. Ice Complex formation in arctic East Siberia during the MIS3 Interstadial

    NASA Astrophysics Data System (ADS)

    Wetterich, Sebastian; Tumskoy, Vladimir; Rudaya, Natalia; Andreev, Andrei A.; Opel, Thomas; Meyer, Hanno; Schirrmeister, Lutz; Hüls, Matthias

    2014-01-01

    A continuous 15 m long sequence of Ice Complex permafrost (Yedoma) exposed in a thermo-cirque at the southern coast of Bol'shoy Lyakhovsky Island (New Siberian Archipelago, Dmitry Laptev Strait) was studied to reconstruct past landscape and environmental dynamics. The sequence accumulated during the Marine Isotope Stage 3 (MIS3) Interstadial between >49 and 29 ka BP in an ice-wedge polygon. The frozen deposits were cryolithologically described and sampled on a vertical bluff between two ice wedges. According to sedimentological and geochronological data, the section is subdivided into three units which correlate with environmental conditions of the early, middle, and late MIS3 period. Palynological data support this stratification. The stable isotope signature of texture ice in the polygon structure reflects fractionation due to local freeze-thaw processes, while the signature of an approximately 5 m wide and more than 17 m high ice wedge fits very well into the regional stable-water isotope record. Regional climate dynamics during the MIS3 Interstadial and local landscape conditions of the polygonal patterned ground controlled the Ice Complex formation. The sequence presented here completes previously published MIS3 permafrost records in Northeast Siberia. Late Quaternary stadial-interstadial climate variability in arctic West Beringia is preserved at millennial resolution in the Ice Complex. A MIS3 climate optimum was revealed between 48 and 38 ka BP from the Ice Complex on Bol'shoy Lyakhovsky Island.

  14. Planet Formation

    NASA Astrophysics Data System (ADS)

    Chambers, J. E.

    2003-12-01

    Modern theories for the origin of the planets are based on observations of the solar system and star-forming regions elsewhere in the galaxy, together with the results of numerical models. Some key observations are: - The solar system contains eight large planets with roughly circular, coplanar orbits lying 0.4-30 AU from the Sun. There are few locations between the planets where additional large objects could exist on stable orbits. - The major planets are grouped: small volatile-poor planets lie close to the Sun, with large volatile-rich planets further out. The main asteroid belt (2-4 AU from the Sun) is substantially depleted in mass with respect to other regions. - The planets and asteroids are depleted in volatile elements compared to the Sun. The degree of fractionation decreases with distance: the terrestrial planets and inner-belt asteroids are highly depleted in volatiles, the outer-belt asteroids are less so, while many satellites in the outer solar system are ice rich. Primitive CI meteorites (probably from the outer asteroid belt) have elemental abundances very similar to the Sun except for highly volatile elements. - Ancient solid surfaces throughout the solar system are covered in impact craters (e.g., the Moon, Mercury, Mars, Callisto). Most of the planets have large axial tilts with respect to their orbits. Earth possesses a large companion with a mass ˜1% that of the planet itself. - The terrestrial planets and many asteroids have undergone differentiation. There is strong evidence that Saturn is highly centrally condensed, with a core of mass ˜10M?, and weaker evidence that Jupiter has a core of similar mass. These cores have masses comparable to Uranus and Neptune. - Meteorites from the main asteroid belt show evidence that they once contained short-lived radioactive isotopes with half-lives <10 Myr. The main components of primitive meteorites (chondrules and refractory inclusions) have sizes clustered around 1 mm. These components appear to have undergone rapid melting and cooling. - Young stars generally exist in gas- and dust-rich environments. Many young stars possess massive, optically thick disks with diameters of 10-1,000 AU. These disks are inferred to have lifetimes of ˜1-10 Myr. - At least 4% of main sequence (ordinary) stars have planetary-mass companions. The companions have masses of 0.1-10 Jupiter masses (the lower limit is the current detection threshhold), and orbital distances from 0.05 AU to 5 AU (the upper limit is the current detection threshhold).These observations have led to the development and refinement of a theory in which the planets formed from a disk-shaped protoplanetary nebula (Laplace) by pairwise accretion of small solid bodies (Safranov, 1969). A variant of the standard model invokes the gravitational collapse of portions of this disk to form gas giant planets directly. It should be pointed out that the standard model is designed to explain the planets observed in the solar system. Attempts to account for planetary systems recently discovered orbiting other stars suggest that planet formation is likely to differ in several respects from one system to another.

  15. Cave Formations and Waterlines

    USGS Multimedia Gallery

    A series of speleothems, or cave formations, in the Caverns of Sonora. A prior waterline can be seen in the formations where the color changes from primarily white (formations formed in the air) to more beige (formations formed underwater). In addition, the previously submerged formations are larger...

  16. Postmodern Internetwork Architecture Bobby Bhattacharjee, Ken Calvert, Jim Griffioen,

    E-print Network

    Spring, Neil

    -known: various hacks, layering violations, and overloadings are introduced to enforce policies and attempt to get of scale offered by the unified Internet. We will use the postmodern architecture to explore basic. The Internet has fulfilled the potential of a complete generation of networking research by producing a global

  17. 76 FR 4391 - Calvert Cliffs Nuclear Power Plant, LLC, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-25

    ...and orders of the Nuclear Regulatory Commission...for light- water nuclear power reactors...pressurized light-water nuclear power reactor fueled...that the rate of energy release, hydrogen...the metal/water reaction shall be calculated...design consists of low enriched...

  18. Low-frequency unsteadiness in the vortex formation region of a circular cylinder

    NASA Astrophysics Data System (ADS)

    Lehmkuhl, O.; Rodríguez, I.; Borrell, R.; Oliva, A.

    2013-08-01

    The presence of low-frequency fluctuations in the wake of bluff bodies have been observed in several investigations. Even though the flow past a circular cylinder at Re = 3900 (Re = UrefD/?) has been the object of several experimental and numerical investigations, there is a large scattering in the average statistics in the near wake. In the present work, the flow dynamics of the near wake region behind a circular cylinder has been investigated by means of direct numerical simulations and statistics have been computed for more than 858 shedding cycles. The analysis of instantaneous velocity signals of several probes located in the vortex formation region, point out the existence of a low-frequency fluctuation at the non-dimensional frequency of fm = 0.0064. This large-scale almost periodic motion seems to be related with the modulation of the recirculation bubble which causes its shrinking and enlargement over the time. Two different configurations have been identified: (i) a high-energy mode with larger fluctuations in the shear-layer and in the vortex formation region (Mode H) and (ii) a low-energy mode with weaker fluctuations in the shear layer (Mode L). The influence of such a low-frequency in the wake topology has been studied not only by means of the phase-average flow field for each mode, but also by the analysis of the time-average first- and second-order statistics of each wake mode. The results are compared with the long-term averaged solution and with results in the existing literature.

  19. Pollen analysis of a late pliocene and early pleistocene section from the Gubik Formation of Arctic Alaska

    USGS Publications Warehouse

    Nelson, R.E.; Carter, L.D.

    1985-01-01

    A 14-m-thick section of marine and nonmarine sediments of the Gubik Formation of northern Alaska, exposed in bluffs near Ocean Point on the Colville River, has been studied by means of pollen analysis. Pollen from the marine sediments, of probable late Pliocene age, records a boreal forest of spruce and birch with minor amounts of alder in the adjacent terrestrial vegetation. Pine and perhaps true fir were probably at or near their northern limit here, but hemlocks and hardwoods were absent. The suggested environment for the Arctic Slope during the time represented by the marine sediments is similar to that of present-day Anchorage. Pollen floras from the overlying fluvial strata, of early or middle Pleistocene age, record predominantly herbaceous taxa indicating tundra conditions probably more severe than those of the present day. These deposits were most likely contemporaneous with glacial conditions in the Brooks Range to the south. Pollen of woody taxa (spruce, alder, birch, heaths) is rare through most of the section, although birch and alder percentages similar to those found in modern river sediments indicate an interstadial or interglacial warming in midsection. Inland climates during glacial episodes may have been similar to those of the present Arctic coast. ?? 1985.

  20. Formate Formation and Formate Conversion in Biological Fuels Production

    PubMed Central

    Crable, Bryan R.; Plugge, Caroline M.; McInerney, Michael J.; Stams, Alfons J. M.

    2011-01-01

    Biomethanation is a mature technology for fuel production. Fourth generation biofuels research will focus on sequestering CO2 and providing carbon-neutral or carbon-negative strategies to cope with dwindling fossil fuel supplies and environmental impact. Formate is an important intermediate in the methanogenic breakdown of complex organic material and serves as an important precursor for biological fuels production in the form of methane, hydrogen, and potentially methanol. Formate is produced by either CoA-dependent cleavage of pyruvate or enzymatic reduction of CO2 in an NADH- or ferredoxin-dependent manner. Formate is consumed through oxidation to CO2 and H2 or can be further reduced via the Wood-Ljungdahl pathway for carbon fixation or industrially for the production of methanol. Here, we review the enzymes involved in the interconversion of formate and discuss potential applications for biofuels production. PMID:21687599

  1. Water Formatics Engineered formation of nanobubbles networks

    E-print Network

    Jacob, Eshel Ben

    Water Formatics Engineered formation of nanobubbles networks in water and aqueous solutions We present the idea that the anomalous effects of rf-treatments of water and aqueous solution resulted from-bubble exchange interactions. These exchange interactions are mediated by the ordering of the water molecules

  2. Geologic columns for the ICDP-USGS Eyreville A and C cores, Chesapeake Bay impact structure: Postimpact sediments, 444 to 0 m depth

    USGS Publications Warehouse

    Edwards, L.E.; Powars, D.S.; Browning, J.V.; McLaughlin, P.P., Jr.; Miller, K.G.; Self-Trail J.M.; Kulpecz, A.A.; Elbra, T.

    2009-01-01

    A 443.9-m-thick, virtually undisturbed section of postimpact deposits in the Chesapeake Bay impact structure was recovered in the Eyreville A and C cores, Northampton County, Virginia, within the "moat" of the structure's central crater. Recovered sediments are mainly fine-grained marine siliciclastics, with the exception of Pleistocene sand, clay, and gravel. The lowest postimpact unit is the upper Eocene Chickahominy Formation (443.9-350.1 m). At 93.8 m, this is the maximum thickness yet recovered for deposits that represent the return to "normal marine" sedimentation. The Drummonds Corner beds (informal) and the Old Church Formation are thin Oligocene units present between 350.1 and 344.7 m. Above the Oligocene, there is a more typical Virginia coastal plain succession. The Calvert Formation (344.7-225.4 m) includes a thin lower Miocene part overlain by a much thicker middle Miocene part. From 225.4 to 206.0 m, sediments of the middle Miocene Choptank Formation, rarely reported in the Virginia coastal plain, are present. The thick upper Miocene St. Marys and Eastover Formations (206.0-57.8 m) appear to represent a more complete succession than in the type localities. Correlation with the nearby Kiptopeke core indicates that two Pliocene units are present: Yorktown (57.8-32.2 m) and Chowan River Formations (32.2-18.3 m). Sediments at the top of the section represent an upper Pleistocene channel-fill and are assigned to the Butlers Bluff and Occohannock Members of the Nassawadox Formation (18.3-0.6 m). ?? 2009 The Geological Society of America.

  3. Star Formation in Galaxies

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Topics addressed include: star formation; galactic infrared emission; molecular clouds; OB star luminosity; dust grains; IRAS observations; galactic disks; stellar formation in Magellanic clouds; irregular galaxies; spiral galaxies; starbursts; morphology of galactic centers; and far-infrared observations.

  4. TRIHALOMETHANE REMOVAL AND FORMATION

    E-print Network

    District of Columbia, University of the

    substances, and algae like material also react with aqueous chlorine to produce THMs., The THM formation also in water to give rise to haloform reactions and produce THMs. The organics that lead to the formation

  5. Scenarios for galaxy formation

    NASA Technical Reports Server (NTRS)

    Silk, Joseph

    1997-01-01

    The gravitational instability theory and its application to the origin of large scale structure are reviewed. The modeling of galaxy formation is described, from forwards and backwards perspectives. The emphasis is on the interactions between stellar and galactic formation.

  6. The Format Dilemma.

    ERIC Educational Resources Information Center

    Oder, Norman

    2002-01-01

    Reports results of a survey of public libraries that investigated trends in audiovisual materials. Highlights include format issues; audiobooks; media budgets for various formats; video collections; DVDs; circulation; collection sizes; music CDs; and future possibilities. (LRW)

  7. FORMCON -- Data Format Conversion

    NASA Astrophysics Data System (ADS)

    Lawden, M. D.; Pearce, Dave

    Two data format conversion utilities are available: - IPCSIN: Convert IPCS data to Starlink format. - VICARIN: Convert VICAR data to Starlink format. The Starlink format referred to is that used by the INTERIM Starlink environment described in SUN/4 and used by programs such as those in the ASPIC package. The input data is assumed to be held on magnetic tape. Both these programs are Starlink Application Programs and should be used within the INTERIM environment.

  8. Role of extensional tectonics in the formation of Talladega belt--Blue Ridge successor basins

    SciTech Connect

    Tull, J.F. . Dept. of Geology)

    1993-03-01

    Polydeformed and metamorphosed sequences occurring unconformably above the Cambrian-Ordovician (C-O) miogeoclinal sequence are nested within the Talladega belt (Talladega Group-TG) and Blue Ridge (Mineral Bluff Group-MBG). These successor basin sequences are 2.5--3 km thick and have a possible age range from Ordovician to Devonian, representing the youngest stratigraphic units east of the foreland. They are dominated by turbiditic metaclastic rocks derived from erosion of Grenville basement and its overlying cover of clastic and carbonate rock. Bimodal volcanic rocks occur in the TG, and within-plate mafic extrusive rocks are found in the MBG. The TG consists of a coarsening, thickening, and shallowing upward sequence with a submarine fan-like unit (Lay Dam Formation-LDF) at the base. The LDF contains a thick proximal boulder-bearing olistostromal facies with debris fan lobes stacked vertically and shed from a proximal fault scarp to the SE or S. The vertical stacking of olistostromal deposits, absence of crystalline-cored thrust sheets of this age at the structural top of the basin, and other relationships indicate that the basin did not result from detached deformation to the SE or transcurrent faulting, but rather from extensional faulting. Relationships within the C-O carbonate sequence (Sylacauga Marble Group) unconformably below the TG indicate that the TG basin developed above shallow shelf miogeoclinal rocks inboard of the continental margin hinge line, and thus indicate that Silurian-Devonian extensional structures affected relatively thick Laurentian crust. Similarities in lithofacies and stratigraphic sequence between the TG and MBG indicate that the settling of the MBG may have also been within an extensional basin but basin boundary faults have not yet been identified within the structural block below the pre-MBG unconformity. This basin developed above Laurentian crust previously thinned during late Protozoic rifting.

  9. Star Formation for Predictive Primordial Galaxy Formation

    E-print Network

    Milosavljevic, Milos

    2015-01-01

    The elegance of inflationary cosmology and cosmological perturbation theory ends with the formation of the first stars and galaxies, the initial sources of light that launched the phenomenologically rich process of cosmic reionization. Here we review the current understanding of early star formation, emphasizing unsolved problems and technical challenges. We begin with the first generation of stars to form after the Big Bang and trace how they influenced subsequent star formation. The onset of chemical enrichment coincided with a sharp increase in the overall physical complexity of star forming systems. Ab-initio computational treatments are just now entering the domain of the predictive and are establishing contact with local observations of the relics of this ancient epoch.

  10. Tropical cyclone formation

    SciTech Connect

    Montgomery, M.T.; Farrell, B.F. )

    1993-01-15

    The physics of tropical cyclone formation is not well understood, and more is known about the mature hurricane than the formative mechanisms that produce it. It is believed part of the reason for this can be traced to insufficient upper-level atmospheric data. Recent observations suggest that tropical cyclones are initiated by asymmetric interactions associated with migratory upper-level potential vorticity disturbances and low-level disturbances. Favored theories of cyclones formation, however, focus on internal processes associated with cumulus convection and/or air-sea interaction. This work focuses on external mechanisms of cyclone formation and, using both a two- and three-dimensional moist geostrophic momentum model, investigates the role of upper-level potential vorticity disturbances on the formation process. A conceptual model of tropical cyclone formation is proposed, and implications of the theory are discussed. 71 refs., 5 figs., 1 tab.

  11. Aspects of Galaxy Formation

    E-print Network

    Joseph Silk

    2001-12-13

    I describe some of the current challenges in galaxy formation theory with applications to formation of disks and of spheroids. Forthcoming deep surveys of galaxies with Keck and VLT will provide high quality spectra of $\\sim 10^5$ galaxies that will probe stellar populations and star formation rates at redshift unity. This will help refine our phenomenological knowledge of galaxy evolution and enable robust predictions to be developed for future breakthroughs in understanding galaxy formation at high redshift that are anticipated with NGST and with the proposed new generation of 30 metre-class telescopes.

  12. ADVANCED FORENSIC FORMAT: AN OPEN, EXTENSIBLE FORMAT

    E-print Network

    Malan, David J.

    . Malan, K. Dubec, C. Stevens and C. Pham Abstract This paper describes the Advanced Forensic Format (AFF). This paper also describes the Advanced Disk Imager (AImage), a new program for acquiring disk images for divorce. Police might raid a drug dealer's apartment and seize a computer that was used for contacting

  13. GLOBAL STAR FORMATION REVISITED

    SciTech Connect

    Silk, Joseph; Norman, Colin E-mail: norman@stsci.edu

    2009-07-20

    A general treatment of disk star formation is developed from a dissipative multiphase model, with the dominant dissipation due to cloud collisions. The Schmidt-Kennicutt (SK) law emerges naturally for star-forming disks and starbursts. We predict that there should be an inverse correlation between Tully-Fisher law and SK law residuals. The model is extended to include a multiphase treatment of supernova feedback that leads to a turbulent pressure-regulated generalization of the star formation law and is applicable to gas-rich starbursts. Enhanced pressure, as expected in merger-induced star formation, enhances star formation efficiency. An upper limit is derived for the disk star formation rate in starbursts that depends on the ratio of global ISM to cloud pressures. We extend these considerations to the case where the interstellar gas pressure in the inner galaxy is dominated by outflows from a central active galactic nucleus (AGN). During massive spheroid formation, AGN-driven winds trigger star formation, resulting in enhanced supernova feedback and outflows. The outflows are comparable to the AGN-boosted star formation rate and saturate in the super-Eddington limit. Downsizing of both SMBH and spheroids is a consequence of AGN-driven positive feedback. Bondi accretion feeds the central black hole with a specific accretion rate that is proportional to the black hole mass. AGN-enhanced star formation is mediated by turbulent pressure and relates spheroid star formation rate to black hole accretion rate. The relation between black hole mass and spheroid velocity dispersion has a coefficient (Salpeter time to gas consumption time ratio) that provides an arrow of time. Highly efficient, AGN-boosted star formation can occur at high redshift.

  14. Formative Assessment Probes

    ERIC Educational Resources Information Center

    Eberle, Francis; Keeley, Page

    2008-01-01

    Formative assessment probes can be effective tools to help teachers build a bridge between students' initial ideas and scientific ones. In this article, the authors describe how using two formative assessment probes can help teachers determine the extent to which students make similar connections between developing a concept of matter and a…

  15. Star formation Simon Goodwin

    E-print Network

    Crowther, Paul

    Star formation Simon Goodwin Dept Physics & Astronomy, University of Sheffield, Hounsfield Road, Sheffield, S3 7RH, UK. s.goodwin@sheffield.ac.uk 1 Abstract Stars are one of the most important consituents of the Universe, and understanding their formation is crucial to many areas of astrophysics. Stars form from dense

  16. School Formative Feedback Systems

    ERIC Educational Resources Information Center

    Halverson, Richard

    2010-01-01

    Data-driven instructional improvement relies on developing coherent systems that allow school staff to generate, interpret, and act upon quality formative information on students and school programs. This article offers a formative feedback system model that captures how school leaders and teachers structure artifacts and practices to create…

  17. Bedrock geologic map of the Spring Valley, West Plains, and parts of the Piedmont and Poplar Bluff 30'x60' quadrangles, Missouri, including the upper Current River and Eleven Point River drainage basins

    USGS Publications Warehouse

    Weary, David J.; Harrison, Richard W.; Orndorff, Randall C.; Weems, Robert E.; Schindler, J. Stephen; Repetski, John E.; Pierce, Herbert A.

    2015-01-01

    Potentially economic mineral resources are present in the subsurface in the map area. Exploration drill-hole data indicate that anomalously high concentrations of base-metal sulfides locally occur within the Cambrian Bonneterre Formation. The geologic setting of these anomalous concentrations is similar to that found in the Viburnum Trend, part of the largest lead-mining district in the world. The southernmost part of the Viburnum Trend extends into the northern part of the map area and is exploited by the Sweetwater Mine. Undeveloped and potentially economic occurrences of base metals are known also beneath Blair Creek, a tributary to the Current River in the north-central part of the map area.

  18. Simple Data Format A Platform Independent Data Format that

    E-print Network

    California at Berkeley, University of

    are supported Proprietary, no support for C/Fortran FITS format Heritage in solar physics, wide software base format and I/O software that is easy to use and very portable: Simple Data Format (SDF). 1. The SDF fileSimple Data Format ­ A Platform Independent Data Format that works in Fortran, C, and IDL George H

  19. When Efficient Star Formation Drives Cluster Formation

    NASA Astrophysics Data System (ADS)

    Parmentier, G.; Fritze, U.

    2009-01-01

    We investigate the impact of the star-formation efficiency (SFE) in cluster-forming cores (i.e., local SFE) on the evolution of mass in star clusters (SCs) over the age range 1-100 Myr, when SCs undergo their infant weight-loss/mortality phase. Our model builds on the N-body simulation grid of Baumgardt & Kroupa. Assuming a constant formation rate of gas-embedded clusters and a weak tidal field, we show that the ratio between the total mass in stars bound to the clusters over that age range and the total mass in stars initially formed in gas-embedded clusters is a strongly increasing function of the averaged local SFE, with little influence from any assumed core mass-radius relation. Our results suggest that, for young starbursts with estimated tidal field strength and known recent star-formation history, observed cluster-to-star mass ratios, once corrected for the undetected clusters, constitute promising probes of the local SFE without the need to resort to gas mass estimates. Similarly, the mass ratio of stars that remain in bound clusters at the end of the infant mortality/weight-loss phase (i.e., age gsim50 Myr) depends sensitively on the mean local SFE, although the impacts of the width of the SFE distribution function and of the core mass-radius relation require more careful assessment in this case. Following the recent finding by Bastian that galaxies form, on average, 8% of their stars in bound clusters regardless of their star-formation rate, we raise the hypothesis that star formation in the present-day universe is characterized by a near-universal distribution of the local SFE. A related potential application of our model is in tracing the evolution of the local SFE over cosmological lookback times by comparing the age distribution of the total mass in SCs to that in field stars in galaxies where field stars can be resolved and age dated. We describe aspects of our model which are still to be worked out before this goal can be achieved.

  20. Sparse Image Format

    Energy Science and Technology Software Center (ESTSC)

    2007-04-12

    The Sparse Image Format (SIF) is a file format for storing spare raster images. It works by breaking an image down into tiles. Space is savid by only storing non-uniform tiles, i.e. tiles with at least two different pixel values. If a tile is completely uniform, its common pixel value is stored instead of the complete tile raster. The software is a library in the C language used for manipulating files in SIF format. Itmore »supports large files (> 2GB) and is designed to build in Windows and Linux environments.« less

  1. Star Formation Ralf Klessen

    E-print Network

    Klessen,Ralf

    bangl) Stars form in galaxies and protogalaxies star formation at high redshift (Hubble Ultra-Deep Field, from HST Web site) #12;Antennae galaxy NGC4038/39 distance: 19.2Mpc vis. Magn: 11.2 optical: white

  2. Notes on Star Formation

    E-print Network

    Krumholz, Mark R

    2015-01-01

    This book provides an introduction to the field of star formation at a level suitable for graduate students or advanced undergraduates in astronomy or physics. The structure of the book is as follows. The first two chapters begin with a discussion of observational techniques, and the basic phenomenology they reveal. The goal is to familiarize students with the basic techniques that will be used throughout, and to provide a common vocabulary for the rest of the book. The next five chapters provide a similar review of the basic physical processes that are important for star formation. Again, the goal is to provide a basis for what follows. The remaining chapters discuss star formation over a variety of scales, starting with the galactic scale and working down to the scales of individual stars and their disks. The book concludes with a brief discussion of the clearing of disks and the transition to planet formation. The book includes five problem sets, complete with solutions.

  3. Formation of Giant Planets

    NASA Technical Reports Server (NTRS)

    Lin, Douglas

    1999-01-01

    Under the support of NASA Origins grant, we studied the formation of gaps in protoplanetary disks due the tidal interaction between a fully grown protoplanet and protostellar disk. The result of this study is published in the Astrophysical Journal, (vol 514, 344-367, 1999) and in several conference proceedings. The main focus of this work is to analyze planet-disk interaction during the final stages of protoplanetary formation.

  4. Plant Formate Dehydrogenase

    SciTech Connect

    John Markwell

    2005-01-10

    The research in this study identified formate dehydrogenase, an enzyme that plays a metabolic role on the periphery of one-carbon metabolism, has an unusual localization in Arabidopsis thaliana and that the enzyme has an unusual kinetic plasticity. These properties make it possible that this enzyme could be engineered to attempt to engineer plants with an improved photosynthetic efficiency. We have produced transgenic Arabidopsis and tobacco plants with increased expression of the formate dehydrogenase enzyme to initiate further studies.

  5. Display formats manual

    NASA Technical Reports Server (NTRS)

    Runnels, R. L.

    1973-01-01

    The standards and procedures for the generation of operational display formats to be used in the Mission Control Center (MCC) display control system are presented. The required effort, forms, and fundamentals for the design, specifications, and production of display formats are identified. The principles of display design and system constraints controlling the creation of optimum operational displays for mission control are explained. The basic two types of MCC display systems for presenting information are described.

  6. Autonomous Formation Flight

    NASA Technical Reports Server (NTRS)

    Schkolnik, Gerard S.; Cobleigh, Brent

    2004-01-01

    NASA's Strategic Plan for the Aerospace Technology Enterprise includes ambitious objectives focused on affordable air travel, reduced emissions, and expanded aviation-system capacity. NASA Dryden Flight Research Center, in cooperation with NASA Ames Research Center, the Boeing Company, and the University of California, Los Angeles, has embarked on an autonomous-formation-flight project that promises to make significant strides towards these goals. For millions of years, birds have taken advantage of the aerodynamic benefit of flying in formation. The traditional "V" formation flown by many species of birds (including gulls, pelicans, and geese) enables each of the trailing birds to fly in the upwash flow field that exists just outboard of the bird immediately ahead in the formation. The result for each trailing bird is a decrease in induced drag and thus a reduction in the energy needed to maintain a given speed. Hence, for migratory birds, formation flight extends the range of the system of birds over the range of birds flying solo. The Autonomous Formation Flight (AFF) Project is seeking to extend this symbiotic relationship to aircraft.

  7. Positronium Formation in Muscle

    PubMed Central

    Gustafson, D. R.

    1970-01-01

    Positronium formation in muscle at +4°C and -4°C was examined by the measurement of the angular correlation of positron annihilation radiation. Since the positronium formation rate in ice is considerably higher than it is in water, there should be a comparable increase in the positronium formation rate in muscle tissue if recent speculation that cellular water is ordered in a semicrystalline icelike state is correct. Comparison of the angular correlation from muscle at +4°C with that from water at +4°C shows no enhancement of the positronium formation rate. Frozen muscle at -4°C shows an enhancement of the positronium formation rate of approximately half that found in ice at -4°C, indicating that most cellular water undergoes a normal water-ice transition when frozen. It is concluded therefore that cell water in muscle is not ordered in a hexagonal icelike structure. While the results are consistent with the hypothesis that cell water is in the liquid state, the hypothesis that cell water is ordered in an undetermined close packed structure which transforms to the hexagonal ice structure at or near 0°C cannot be ruled out. PMID:5436881

  8. Vascular Lumen Formation

    PubMed Central

    Lammert, Eckhard; Axnick, Jennifer

    2012-01-01

    The vascular system developed early in evolution. It is required in large multicellular organisms for the transport of nutrients, oxygen, and waste products to and from tissues. The vascular system is composed of hollow tubes, which have a high level of complexity in vertebrates. Vasculogenesis describes the de novo formation of blood vessels, e.g., aorta formation in vertebrate embryogenesis. In contrast, angiogenesis is the formation of blood vessels from preexisting ones, e.g., sprouting of intersomitic blood vessels from the aorta. Importantly, the lumen of all blood vessels in vertebrates is lined and formed by endothelial cells. In both vasculogenesis and angiogenesis, lumen formation takes place in a cord of endothelial cells. It involves a complex molecular mechanism composed of endothelial cell repulsion at the cell–cell contacts within the endothelial cell cords, junctional rearrangement, and endothelial cell shape change. As the vascular system also participates in the course of many diseases, such as cancer, stroke, and myocardial infarction, it is important to understand and make use of the molecular mechanisms of blood vessel formation to better understand and manipulate the pathomechanisms involved. PMID:22474612

  9. Gaussian entanglement of formation

    SciTech Connect

    Wolf, M.M.; Giedke, G.; Krueger, O.; Werner, R. F.; Cirac, J.I.

    2004-05-01

    We introduce a Gaussian version of the entanglement of formation adapted to bipartite Gaussian states by considering decompositions into pure Gaussian states only. We show that this quantity is an entanglement monotone under Gaussian operations and provide a simplified computation for states of arbitrary many modes. For the case of one mode per site the remaining variational problem can be solved analytically. If the considered state is in addition symmetric with respect to interchanging the two modes, we prove additivity of the considered entanglement measure. Moreover, in this case and considering only a single copy, our entanglement measure coincides with the true entanglement of formation.

  10. Isolating Triggered Star Formation

    SciTech Connect

    Barton, Elizabeth J.; Arnold, Jacob A.; Zentner, Andrew R.; Bullock, James S.; Wechsler, Risa H.; /KIPAC, Menlo Park /SLAC

    2007-09-12

    Galaxy pairs provide a potentially powerful means of studying triggered star formation from galaxy interactions. We use a large cosmological N-body simulation coupled with a well-tested semi-analytic substructure model to demonstrate that the majority of galaxies in close pairs reside within cluster or group-size halos and therefore represent a biased population, poorly suited for direct comparison to 'field' galaxies. Thus, the frequent observation that some types of galaxies in pairs have redder colors than 'field' galaxies is primarily a selection effect. We use our simulations to devise a means to select galaxy pairs that are isolated in their dark matter halos with respect to other massive subhalos (N= 2 halos) and to select a control sample of isolated galaxies (N= 1 halos) for comparison. We then apply these selection criteria to a volume-limited subset of the 2dF Galaxy Redshift Survey with M{sub B,j} {le} -19 and obtain the first clean measure of the typical fraction of galaxies affected by triggered star formation and the average elevation in the star formation rate. We find that 24% (30.5 %) of these L* and sub-L* galaxies in isolated 50 (30) h{sup -1} kpc pairs exhibit star formation that is boosted by a factor of {approx}> 5 above their average past value, while only 10% of isolated galaxies in the control sample show this level of enhancement. Thus, 14% (20 %) of the galaxies in these close pairs show clear triggered star formation. Our orbit models suggest that 12% (16%) of 50 (30) h{sup -1} kpc close pairs that are isolated according to our definition have had a close ({le} 30 h{sup -1} kpc) pass within the last Gyr. Thus, the data are broadly consistent with a scenario in which most or all close passes of isolated pairs result in triggered star formation. The isolation criteria we develop provide a means to constrain star formation and feedback prescriptions in hydrodynamic simulations and a very general method of understanding the importance of triggered star formation in a cosmological context.

  11. Kepler Planet Formation

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2015-01-01

    Kepler has vastly increased our knowledge of planets and planetary systems located close to stars. The new data shows surprising results for planetary abundances, planetary spacings and the distribution of planets on a mass-radius diagram. The implications of these results for theories of planet formation will be discussed.

  12. Formation of planetesimals

    NASA Technical Reports Server (NTRS)

    Weidenschilling, Stuart J.

    1991-01-01

    Formation of planetesimals is discussed. The following subject areas are covered: (1) nebular structure; (2) aerodynamics of the solid bodies in the nebula; (3) problems with gravitational instability; (4) particle growth by coagulation; properties of fractal aggregates; and (5) coagulation and settling of fractal aggregates.

  13. The Formation of Trihalomethanes.

    ERIC Educational Resources Information Center

    Trussell, R. Rhodes; Umphres, Mark D.

    1978-01-01

    Reviewed are a number of factors important in the formation of trihalomethanes (THM) including the nature of aquatic humus and the influences of preozonation, bromide, pH, and chlorine. A brief investigation is also conducted into the kinetics of the THM reaction. Several major research needs are represented. (CS)

  14. Technobabble: File Formats.

    ERIC Educational Resources Information Center

    Wilson, Bradley

    1999-01-01

    Considers the confusion of over 20 different kinds of graphics programs. Briefly distinguishes between some of the more popular graphics formats (Photoshop, TIFF, JPEG, GIF, PICT, and EPS), and describes the benefits and disadvantages of each in the context of journalism education. (SC)

  15. Bacterial formate hydrogenlyase complex

    PubMed Central

    McDowall, Jennifer S.; Murphy, Bonnie J.; Haumann, Michael; Palmer, Tracy; Armstrong, Fraser A.; Sargent, Frank

    2014-01-01

    Under anaerobic conditions, Escherichia coli can carry out a mixed-acid fermentation that ultimately produces molecular hydrogen. The enzyme directly responsible for hydrogen production is the membrane-bound formate hydrogenlyase (FHL) complex, which links formate oxidation to proton reduction and has evolutionary links to Complex I, the NADH:quinone oxidoreductase. Although the genetics, maturation, and some biochemistry of FHL are understood, the protein complex has never been isolated in an intact form to allow biochemical analysis. In this work, genetic tools are reported that allow the facile isolation of FHL in a single chromatographic step. The core complex is shown to comprise HycE (a [NiFe] hydrogenase component termed Hyd-3), FdhF (the molybdenum-dependent formate dehydrogenase-H), and three iron-sulfur proteins: HycB, HycF, and HycG. A proportion of this core complex remains associated with HycC and HycD, which are polytopic integral membrane proteins believed to anchor the core complex to the cytoplasmic side of the membrane. As isolated, the FHL complex retains formate hydrogenlyase activity in vitro. Protein film electrochemistry experiments on Hyd-3 demonstrate that it has a unique ability among [NiFe] hydrogenases to catalyze production of H2 even at high partial pressures of H2. Understanding and harnessing the activity of the FHL complex is critical to advancing future biohydrogen research efforts. PMID:25157147

  16. FORMATION OF PHOTOCHEMICAL AEROSOLS

    EPA Science Inventory

    The objective was to develop a better understanding of smog aerosol formation with particular reference to haze in the Southern California area. This study combined laboratory work with ambient air studies. Counting of particles by light scattering was the principle physical tech...

  17. Decentralized Formation Selection Mechanisms

    E-print Network

    Egerstedt, Magnus

    bottlenose dolphins belong) are complex and intelligent ani- mals. The Encephalization Quotient (E.Q.), which is the brain to body mass ratio, is a factor often used to judge intelligence, and dolphins rate 2nd in E Bottlenose Dolphins M.A. Haque and M. Egerstedt 1 Introduction Formation control is an important sub

  18. Hair follicle Formation of

    E-print Network

    Chuong, Cheng-Ming

    Hair follicle Formation of new follicles Bud Healed skin Hair bulge Open wound Epidermis a b Dermis 1950s and help to explain the controversy. What is the origin of the cells that make up these new hair follicles? Are they derived from existing hair follicles located at the wound edge

  19. Queen's Garden Formations

    USGS Multimedia Gallery

    Views along the Queen's Garden Trail in Bryce Canyon National Park. Bryce Canyon is a unique sandstone formation in southern Utah. It is home to a large number of hoodoos, which are oddly shaped pillars of rock that formed due to different erosion rates for the dolomite that caps them and the sands...

  20. Formation in the Classroom

    ERIC Educational Resources Information Center

    Glennon, Fred; Jacobsen, Douglas; Jacobsen, Rhonda Hustedt; Thatamanil, John J.; Porterfield, Amanda; Moore, Mary Elizabeth

    2011-01-01

    What is the relationship between the academic knowledge of the guild and the formation of students in the classroom? This Forum gathers four essays originally presented at a Special Topics Session at the 2009 conference of the American Academy of Religion (Atlanta, Georgia), with a brief introductory essay by Fred Glennon explaining the genesis of…

  1. CO2 SEQUESTRATION POTENTIAL OF TEXAS LOW-RANK COALS

    SciTech Connect

    Duane A. McVay; Walter B. Ayers Jr.; Jerry L. Jensen

    2003-10-01

    The objectives of this project are to evaluate the feasibility of carbon dioxide (CO{sub 2}) sequestration in Texas low-rank coals and to determine the potential for enhanced coalbed methane (CBM) recovery as an added benefit of sequestration. The main objective for this reporting period was to further characterize the three areas selected as potential CO{sub 2} sequestration sites. Well-log data are critical for defining depth, thickness, number, and grouping of coal seams at the proposed sequestration sites. Thus, we purchased 12 hardcopy well logs (in addition to 15 well logs obtained during previous quarter) from a commercial source and digitized them to make coal-occurrence maps and cross sections. Detailed correlation of coal zones is important for reservoir analysis and modeling. Thus, we correlated and mapped Wilcox Group subdivisions--the Hooper, Simsboro and Calvert Bluff formations, as well as the coal-bearing intervals of the Yegua and Jackson formations in well logs. To assess cleat properties and describe coal characteristics, we made field trips to Big Brown and Martin Lake coal mines. This quarter we also received CO{sub 2} and methane sorption analyses of the Sandow Mine samples, and we are assessing the results. GEM, a compositional simulator developed by the Computer Modeling Group (CMG), was selected for performing the CO{sub 2} sequestration and enhanced CBM modeling tasks for this project. This software was used to conduct preliminary CO{sub 2} sequestration and methane production simulations in a 5-spot injection pattern. We are continuing to pursue a cooperative agreement with Anadarko Petroleum, which has already acquired significant relevant data near one of our potential sequestration sites.

  2. Medusae Fossae Formation

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 10 April 2002) The Science This THEMIS visible image was acquired near 7o S, 172o W (188o E) and shows a remarkable martian geologic deposit known as the Medusae Fossae Formation. This Formation, seen here as the raised plateau in the upper two-thirds of the image, is a soft, easily eroded deposit that extends for nearly 1,000 km along the equator of Mars. In this region the deposit has been heavily eroded by the wind to produce a series of linear ridges called yardangs. These parallel ridges point in direction of the prevailing winds that carved them, and demonstrate the power of martian winds to sculpt the dry landscape of Mars. The Medusae Fossae Formation has been completely stripped from the surface in the lower third of the image, revealing a harder layer below that is more resistant to wind erosion. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Several ancient craters that were once completely buried by this deposit are being exposed, or exhumed, as the overlying Medusae Formation is removed. Very few impact craters are visible on this Formation, indicating that the surface seen today is relatively young, and that the processes of erosion are likely to be actively occurring. The Story Medusa of Greek mythology fame, the name-giver to this region, had snaky locks of hair that could turn a person to stone. Wild and unruly, this monster of the underworld could certainly wreak havoc on the world of the human imagination. As scary as she was, Medusa would have no advantage over the fierce, masterful winds blowing across Mars, which once carved the streaky, terrain at the top of this image. Wild and whipping, these winds have slowly eroded away the 'topsoil,' revealing ancient craters and other surface features they once covered. The loosely cemented particles of this 'topsoil' are likely made up of dust or volcanic ash, and are thus more susceptible to windblown erosion. The Martian winds have actually been strong and relentless enough over time to strip the land in the bottom of this image of the material that once covered it, leaving it hard and bare to the eye.

  3. Cosmological structure formation

    NASA Technical Reports Server (NTRS)

    Schramm, David N.

    1991-01-01

    A summary of the current forefront problem of physical cosmology, the formation of structures (galaxies, clusters, great walls, etc.) in the universe is presented. Solutions require two key ingredients: (1) matter; and (2) seeds. Regarding the matter, it now seems clear that both baryonic and non-baryonic matter are required. Whether the non-baryonic matter is hot or cold depends on the choice of seeds. Regarding the seeds, both density fluctuations and topological defects are discussed. The combination of isotropy of the microwave background and the recent observations indicating more power on large scales have severly constrained, if not eliminated, Gaussian fluctuations with equal power on all scales, regardless of the eventual resolution of both the matter and seed questions. It is important to note that all current structure formation ideas require new physics beyond SU(3) x SU(2) x U(1).

  4. Moment formation in solids

    SciTech Connect

    Buyers, W.J.L.

    1984-01-01

    The problem of moment formation in metallic systems lies at the interface of localized and itinerant magnetism. The phenomena observed correspond to destruction rather than to formation of spin-correlations. They give rise to the progression from localized ground states through Kondo and mixed-valence behavior to itinerant magnetic or non-magnetic systems. Somewhere in the progression superconductivity can occur in the presence of f-moments. This conference presents information on the following topics: neuron inelastic scattering as a probe of moments in metallic systems; cyclotron resonance and relaxation of hot charge carriers; orbital effects in actinide systems; theory of elementary excitations in intermediate valence materials: phenomena involving magnetic moment suppresion; and superconducting ground state of a strongly interacting electron system: UBe/sub 13/.

  5. Formation of bacterial nanocells

    NASA Astrophysics Data System (ADS)

    Vainshtein, Mikhail; Kudryashova, Ekaterina; Suzina, Natalia; Ariskina, Elena; Voronkov, Vadim

    1998-07-01

    Existence of nanobacteria received increasing attention both in environmental microbiology/geomicro-biology and in medical microbiology. In order to study a production of nanoforms by typical bacterial cells. Effects of different physical factors were investigated. Treatment of bacterial cultures with microwave radiation, or culturing in field of electric current resulted in formation a few types of nanocells. The number and type of nanoforms were determined with type and dose of the treatment. The produced nanoforms were: i) globules, ii) clusters of the globules--probably produced by liaison, iii) nanocells coated with membrane. The viability of the globules is an object opened for doubts. The nanocells discovered multiplication and growth on solidified nutrient media. The authors suggest that formation of nanocells is a common response of bacteria to stress-actions produced by different agents.

  6. Prominence Formation Processes

    NASA Astrophysics Data System (ADS)

    Welsch, B. T.; DeVore, C. R.; Antiochos, S. K.

    2005-01-01

    Martens and Zwaan (ApJ v. 558 872) have proposed a prominence/ filament formation model in which differential rotation drives reconnection between two initially unconnected active regions to form helical field lines that support mass and are held down by overlying field. Using an MHD solver with adaptive refinement we simulated this process by imposing a shear flow meant to mimic differential rotation on two bipolar flux distributions meant to mimic distinct active regions. In some runs the flux systems are initially potential while in others they have been twisted by footpoint rotation to inject helicity prior to imposing the shear flow. The resulting structures are studied to understand the role of helicity in the formation of prominence-like structures.

  7. Tetrahedron Formation Control

    NASA Technical Reports Server (NTRS)

    Petruzzo, Charles; Guzman, Jose

    2004-01-01

    This paper considers the preliminary development of a general optimization procedure for tetrahedron formation control. The maneuvers are assumed to be impulsive and a multi-stage optimization method is employed. The stages include (1) targeting to a fixed tetrahedron location and orientation, and (2) rotating and translating the tetrahedron. The number of impulsive maneuvers can also be varied. As the impulse locations and times change, new arcs are computed using a differential corrections scheme that varies the impulse magnitudes and directions. The result is a continuous trajectory with velocity discontinuities. The velocity discontinuities are then used to formulate the cost function. Direct optimization techniques are employed. The procedure is applied to the NASA Goddard Magnetospheric Multi-Scale (MMS) mission to compute preliminary formation control fuel requirements.

  8. Emptiness Formation Probability

    E-print Network

    Nicholas Crawford; Stephen Ng; Shannon Starr

    2014-12-30

    We present rigorous upper and lower bounds on the emptiness formation probability for the ground state of a spin-$1/2$ Heisenberg XXZ quantum spin system. For a $d$-dimensional system we find a rate of decay of the order $\\exp(-c L^{d+1})$ where $L$ is the sidelength of the box in which we ask for the emptiness formation event to occur. In the $d=1$ case this confirms previous predictions made in the integrable systems community, though our bounds do not achieve the precision predicted by Bethe ansatz calculations. On the other hand, our bounds in the case $d \\geq 2$ are new. The main tools we use are reflection positivity and a rigorous path integral expansion which is a variation on those previously introduced by Toth, Aizenman-Nachtergaele and Ueltschi.

  9. Format( )MEDIC( )Input

    NASA Astrophysics Data System (ADS)

    Foster, K.

    1994-09-01

    This document is a description of a computer program called Format( )MEDIC( )Input. The purpose of this program is to allow the user to quickly reformat wind velocity data in the Model Evaluation Database (MEDb) into a reasonable 'first cut' set of MEDIC input files (MEDIC.nml, StnLoc.Met, and Observ.Met). The user is cautioned that these resulting input files must be reviewed for correctness and completeness. This program will not format MEDb data into a Problem Station Library or Problem Metdata File. A description of how the program reformats the data is provided, along with a description of the required and optional user input and a description of the resulting output files. A description of the MEDb is not provided here but can be found in the RAS Division Model Evaluation Database Description document.

  10. Formate-assisted pyrolysis

    DOEpatents

    DeSisto, William Joseph; Wheeler, Marshall Clayton; van Heiningen, Adriaan R. P.

    2015-03-17

    The present invention provides, among other thing, methods for creating significantly deoxygenated bio-oils form biomass including the steps of providing a feedstock, associating the feedstock with an alkali formate to form a treated feedstock, dewatering the treated feedstock, heating the dewatered treated feedstock to form a vapor product, and condensing the vapor product to form a pyrolysis oil, wherein the pyrolysis oil contains less than 30% oxygen by weight.

  11. Mesospheric cloud formations

    NASA Technical Reports Server (NTRS)

    Forbes, J. M.

    1980-01-01

    Formation of mesospheric clouds as a result of deposition of large amounts of H2O by the heavy lift launch vehicle (HLLV) of the solar power satellite system is discussed. The conditions which must be met in order to form and maintain clouds near the mesopause are described. The frequency and magnitude of H2O injections from the HLLV rocket exhaust are considered.

  12. Ribbed moraine formation

    NASA Astrophysics Data System (ADS)

    Hättestrand, Clas; Kleman, Johan

    Ribbed (Rogen) moraines are conspicuous landforms found in interior parts of formerly glaciated areas. Two major theories for ribbed moraine formation have been suggested in recent years: (i) the shear and stack theory, which explains ribbed moraine formation by shearing and stacking of till slabs or englacially entrained material during compressive flow, followed by basal melt-out of transverse moraine ridges, and (ii) the fracturing theory, according to which ribbed moraines form by fracturing of frozen pre-existing till sheets, at the transition from cold- to warm-based conditions under deglaciating ice sheets. In this paper, we present new data on the distribution of ribbed moraines and their close association with areas of frozen-bed conditions under ice sheets. In addition, we show examples of ribbed moraine ridges that fit together like a jig-saw puzzle. These observations indicate that fracturing and extension of a pre-existing till sheet may be a predominant process in ribbed moraine formation. In summary, we conclude that all described characteristics of ribbed moraines are compatible with the fracturing theory, while the shear and stack theory is hampered by an inability to explain many conspicuous features in the distribution pattern and detailed morphology of ribbed moraines. One implication of the fracturing theory is that the distribution of ribbed moraines can be used to reconstruct the extent of areas that underwent a change from frozen-bed to thawed-bed conditions under former ice sheets.

  13. Terrestrial planet formation

    PubMed Central

    Righter, K.; O’Brien, D. P.

    2011-01-01

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (?106 y), followed by planetesimals to embryos (lunar to Mars-sized objects; few × 106 y), and finally embryos to planets (107–108 y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids. PMID:21709256

  14. Tetrahedron Formation Control

    NASA Technical Reports Server (NTRS)

    Guzman, Jose J.

    2003-01-01

    Spacecraft flying in tetrahedron formations are excellent instrument platforms for electromagnetic and plasma studies. A minimum of four spacecraft - to establish a volume - is required to study some of the key regions of a planetary magnetic field. The usefulness of the measurements recorded is strongly affected by the tetrahedron orbital evolution. This paper considers the preliminary development of a general optimization procedure for tetrahedron formation control. The maneuvers are assumed to be impulsive and a multi-stage optimization method is employed. The stages include targeting to a fixed tetrahedron orientation, rotating and translating the tetrahedron and/or varying the initial and final times. The number of impulsive maneuvers citn also be varied. As the impulse locations and times change, new arcs are computed using a differential corrections scheme that varies the impulse magnitudes and directions. The result is a continuous trajectory with velocity discontinuities. The velocity discontinuities are then used to formulate the cost function. Direct optimization techniques are employed. The procedure is applied to the Magnetospheric Multiscale Mission (MMS) to compute preliminary formation control fuel requirements.

  15. Terrestrial planet formation.

    PubMed

    Righter, K; O'Brien, D P

    2011-11-29

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids. PMID:21709256

  16. Formation of Lunar Swirls

    E-print Network

    Bamford, R A; Cruz, F; Kellett, B J; Fonseca, R A; Silva, L O; Trines, R M G M; Halekas, J S; Kramer, G; Harnett, E; Cairns, R A; Bingham, R

    2015-01-01

    In this paper we show a plausible mechanism that could lead to the formation of the Dark Lanes in Lunar Swirls, and the electromagnetic shielding of the lunar surface that results in the preservation of the white colour of the lunar regolith. We present the results of a fully self-consistent 2 and 3 dimensional particle-in-cell simulations of mini-magnetospheres that form above the lunar surface and show that they are consistent with the formation of `lunar swirls' such as the archetypal formation Reiner Gamma. The simulations show how the microphysics of the deflection/shielding of plasma operates from a kinetic-scale cavity, and show that this interaction leads to a footprint with sharp features that could be the mechanism behind the generation of `dark lanes'. The physics of mini-magnetospheres is described and shown to be controlled by space-charge fields arising due to the magnetized electrons and unmagnetized ions. A comparison between model and observation is shown for a number of key plasma parameters...

  17. Star Formation in Irregular Galaxies.

    ERIC Educational Resources Information Center

    Hunter, Deidre; Wolff, Sidney

    1985-01-01

    Examines mechanisms of how stars are formed in irregular galaxies. Formation in giant irregular galaxies, formation in dwarf irregular galaxies, and comparisons with larger star-forming regions found in spiral galaxies are considered separately. (JN)

  18. Method for measuring pollutant formation

    NASA Technical Reports Server (NTRS)

    Annen, Kurt (Inventor); Stickler, David B. (Inventor)

    2001-01-01

    Diagnostic methods for determining an instantaneous rate of pollutant formation in a combustion system are based on measurement of chemiluminescence intensity generated simultaneously with the formation of the pollutant. The chemiluminescent signal is generated by an analog reaction which occurs in parallel with a key step in the formation of a specific pollutant of interest. The connection between the analog reaction and the pollution reaction is such that the chemiluminescent signal indicates the local, instantaneous formation rate of the pollutant of interest.

  19. Formative Assessment: Simply, No Additives

    ERIC Educational Resources Information Center

    Roskos, Kathleen; Neuman, Susan B.

    2012-01-01

    Among the types of assessment the closest to daily reading instruction is formative assessment. In contrast to summative assessment, which occurs after instruction, formative assessment involves forming judgments frequently in the flow of instruction. Key features of formative assessment include identifying gaps between where students are and…

  20. Petroleum Engineering 321 Formation Evaluation

    E-print Network

    to the solution of formation evaluation problems. General Education None Course Learning Outcomes and Relationship18 Petroleum Engineering 321 Formation Evaluation Credit 4: (3-3) Required for Juniors Catalog Description: Introduction to well-log interpretation for formation evaluation of hydrocarbon

  1. Formation of Carbon Dwarfs

    E-print Network

    Charles L. Steinhardt; Dimitar D. Sasselov

    2012-01-27

    We consider the formation of dwarf carbon stars via accretion from a carbon AGB companion in light of the new 107 object sample of Downes et al. (2004). This sample is now large enough to allow good mass determination via comparison of a composite spectrum to theoretical atmospheric models. Carbon dwarfs of spectral type M are indeed main sequence M dwarfs with enhanced metallicity and carbon abundance. We also calculate the predicted abundance of both M and of F/G carbon dwarfs, and show that the latter should be falsifiable in the near future.

  2. Simulations of Bluff Body Flow Interaction for Noise Source Modeling

    NASA Technical Reports Server (NTRS)

    Khorrami, Medi R.; Lockard David P.; Choudhari, Meelan M.; Jenkins, Luther N.; Neuhart, Dan H.; McGinley, Catherine B.

    2006-01-01

    The current study is a continuation of our effort to characterize the details of flow interaction between two cylinders in a tandem configuration. This configuration is viewed to possess many of the pertinent flow features of the highly interactive unsteady flow field associated with the main landing gear of large civil transports. The present effort extends our previous two-dimensional, unsteady, Reynolds Averaged Navier-Stokes computations to three dimensions using a quasilaminar, zonal approach, in conjunction with a two-equation turbulence model. Two distinct separation length-to-diameter ratios of L/D = 3.7 and 1.435, representing intermediate and short separation distances between the two cylinders, are simulated. The Mach 0.166 simulations are performed at a Reynolds number of Re = 1.66 105 to match the companion experiments at NASA Langley Research Center. Extensive comparisons with the measured steady and unsteady surface pressure and off-surface particle image velocimetry data show encouraging agreement. Both prominent and some of the more subtle trends in the mean and fluctuating flow fields are correctly predicted. Both computations and the measured data reveal a more robust and energetic shedding process at L/D = 3.7 in comparison with the weaker shedding in the shorter separation case of L/D = 1.435. The vortex shedding frequency based on the computed surface pressure spectra is in reasonable agreement with the measured Strouhal frequency.

  3. Bluff Body Flow Simulation Using a Vortex Element Method

    SciTech Connect

    Anthony Leonard; Phillippe Chatelain; Michael Rebel

    2004-09-30

    Heavy ground vehicles, especially those involved in long-haul freight transportation, consume a significant part of our nation's energy supply. it is therefore of utmost importance to improve their efficiency, both to reduce emissions and to decrease reliance on imported oil. At highway speeds, more than half of the power consumed by a typical semi truck goes into overcoming aerodynamic drag, a fraction which increases with speed and crosswind. Thanks to better tools and increased awareness, recent years have seen substantial aerodynamic improvements by the truck industry, such as tractor/trailer height matching, radiator area reduction, and swept fairings. However, there remains substantial room for improvement as understanding of turbulent fluid dynamics grows. The group's research effort focused on vortex particle methods, a novel approach for computational fluid dynamics (CFD). Where common CFD methods solve or model the Navier-Stokes equations on a grid which stretches from the truck surface outward, vortex particle methods solve the vorticity equation on a Lagrangian basis of smooth particles and do not require a grid. They worked to advance the state of the art in vortex particle methods, improving their ability to handle the complicated, high Reynolds number flow around heavy vehicles. Specific challenges that they have addressed include finding strategies to accurate capture vorticity generation and resultant forces at the truck wall, handling the aerodynamics of spinning bodies such as tires, application of the method to the GTS model, computation time reduction through improved integration methods, a closest point transform for particle method in complex geometrics, and work on large eddy simulation (LES) turbulence modeling.

  4. Atmospheric flow over two-dimensional bluff surface obstructions

    NASA Technical Reports Server (NTRS)

    Bitte, J.; Frost, W.

    1976-01-01

    The phenomenon of atmospheric flow over a two-dimensional surface obstruction, such as a building (modeled as a rectangular block, a fence or a forward-facing step), is analyzed by three methods: (1) an inviscid free streamline approach, (2) a turbulent boundary layer approach using an eddy viscosity turbulence model and a horizontal pressure gradient determined by the inviscid model, and (3) an approach using the full Navier-Stokes equations with three turbulence models; i.e., an eddy viscosity model, a turbulence kinetic-energy model and a two-equation model with an additional transport equation for the turbulence length scale. A comparison of the performance of the different turbulence models is given, indicating that only the two-equation model adequately accounts for the convective character of turbulence. Turbulence flow property predictions obtained from the turbulence kinetic-energy model with prescribed length scale are only insignificantly better than those obtained from the eddy viscosity model. A parametric study includes the effects of the variation of the characteristics parameters of the assumed logarithmic approach velocity profile. For the case of the forward-facing step, it is shown that in the downstream flow region an increase of the surface roughness gives rise to higher turbulence levels in the shear layer originating from the step corner.

  5. Trace fossils from the Rock Bluff Limestone (Pennsylvanian, Kansas)

    E-print Network

    Maerz, R. H., Jr.; Kaesler, R. L.; Hakes, W. G.

    1976-01-15

    and calcareous. Within 10 cm of the contact, it contains calcareous nodules. Fossils are abundant, with fragments of brachiopods, whole gastropods, and bivalves being especially prominent. At the locality studied (NE NW NW Sec. 22, T. 12 S, R. 18 S.; 13 km west..., often containing the bivalve Wilkingia; nearly vertical cylindrical burrows packed with fusulinids and bioclastic debris: and the apparent resting burrows of ophiuroids, showing pentameral symmetry with quality dependent upon the coarseness of the bio...

  6. Elimination of Vortex Streets in Bluff-Body Flows

    E-print Network

    2008-05-16

    May 21, 2008 ... fixed, significant oscillations still develop if the cylinder is allowed to freely ... Navier-Stokes equations employing a Fourier expansion along the .... is related to the growth rate of perturbations, and the sign of !I determines the ...

  7. Star Cluster Formation and Star Formation: The Role of Environment and Star Formation Efficiencies

    E-print Network

    Uta Fritze

    2008-01-15

    Analyzing global starburst properties in various kinds of starburst and post-starburst galaxies and relating them to the properties of the star cluster populations they form, I explore the conditions for the formation of massive, compact, long-lived star clusters. The aim is to find out whether the relative amount of star formation that goes into star cluster formation as opposed to field star formation, and into the formation of massive long-lived clusters in particular, is universal or scales with star formation rate, burst strength, star formation efficiency, galaxy or gas mass, and whether or not there are special conditions or some threshold for the formation of star clusters that merit to be called globular clusters a few gigayears later.

  8. CO2 SEQUESTRATION POTENTIAL OF TEXAS LOW-RANK COALS

    SciTech Connect

    Duane A. McVay; Walter B. Ayers Jr.; Jerry L. Jensen

    2005-05-01

    The objectives of this project are to evaluate the feasibility of carbon dioxide (CO{sub 2}) sequestration in Texas low-rank coals and to determine the potential for enhanced coalbed methane (CBM) recovery as an added benefit of sequestration. The main objective for this reporting period was to perform pressure transient testing to determine permeability of deep Wilcox coal to use as additional, necessary data for modeling performance of CO{sub 2} sequestration and enhanced coalbed methane recovery. To perform permeability testing of the Wilcox coal, we worked with Anadarko Petroleum Corporation in selecting the well and intervals to test and in designing the pressure transient test. Anadarko agreed to allow us to perform permeability tests in coal beds in an existing shut-in well (Well APCT2). This well is located in the region of the Sam K. Seymour power station, a site that we earlier identified as a major point source of CO{sub 2} emissions. A service company, Pinnacle Technologies Inc. (Pinnacle) was contracted to conduct the tests in the field. Intervals tested were 2 coal beds with thicknesses of 3 and 7 feet, respectively, at approximately 4,100 ft depth in the Lower Calvert Bluff Formation of the Wilcox Group in east-central Texas. Analyses of pressure transient test data indicate that average values for coalbed methane reservoir permeability in the tested coals are between 1.9 and 4.2 mD. These values are in the lower end of the range of permeability used in the preliminary simulation modeling. These new coal fracture permeability data from the APCT2 well, along with the acquired gas compositional analyses and sorption capacities of CO{sub 2}, CH{sub 4}, and N{sub 2}, complete the reservoir description phase of the project. During this quarter we also continued work on reservoir and economic modeling to evaluate performance of CO{sub 2} sequestration and enhanced coalbed methane recovery.

  9. CO2 Sequestration Potential of Texas Low-Rank Coals

    SciTech Connect

    Duane A. McVay; Walter B. Ayers, Jr; Jerry L. Jensen

    2006-05-01

    The objectives of this project are to evaluate the feasibility of carbon dioxide (CO{sub 2}) sequestration in Texas low-rank coals and to determine the potential for enhanced coalbed methane (ECBM) recovery as an added benefit of sequestration. The main objectives for this reporting period were to (1) determine the effects of permeability anisotropy on performance of CO{sub 2} sequestration and ECBM production in the Lower Calvert Bluff Formation (LCB) of the Wilcox Group coals in east-central Texas, and (2) begin reservoir and economic analyses of CO{sub 2} sequestration and ECBM production using horizontal wells. To evaluate the effects of permeability anisotropy on CO{sub 2} sequestration and ECBM in LCB coal beds, we conducted deterministic reservoir modeling studies of 100% CO{sub 2} gas injection for the 6,200-ft depth base case (Case 1b) using the most likely values of the reservoir parameters. Simulation results show significant differences in the cumulative volumes of CH{sub 4} produced and CO{sub 2} injected due to permeability anisotropy, depending on the orientation of injection patterns relative to the orientation of permeability anisotropy. This indicates that knowledge of the magnitude and orientation of permeability anisotropy will be an important consideration in the design of CO{sub 2} sequestration and ECBM projects. We continued discussions with Anadarko Petroleum regarding plans for additional coal core acquisition and laboratory work to further characterize Wilcox low-rank coals. As part of the technology transfer for this project, we submitted the paper SPE 100584 for presentation at the 2006 SPE Gas Technology Symposium to be held in Calgary, Alberta, Canada on May 15-18, 2006.

  10. Planet Formation - Overview

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.

    2005-01-01

    Modern theories of star and planet formation are based upon observations of planets and smaller bodies within our own Solar System, exoplanets &round normal stars and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. These models predict that rocky planets should form in orbit about most single stars. It is uncertain whether or not gas giant planet formation is common, because most protoplanetary disks may dissipate before solid planetary cores can grow large enough to gravitationally trap substantial quantities of gas. A potential hazard to planetary systems is radial decay of planetary orbits resulting from interactions with material within the disk. Planets more massive than Earth have the potential to decay the fastest, and may be able to sweep up smaller planets in their path.

  11. Fullerene formation and annealing

    SciTech Connect

    Mintmire, J.W.

    1996-04-05

    Why does the highly symmetric carbon cluster C{sub 60} form in such profusion under the right conditions? This question was first asked in 1985, when Kroto suggested that the predominance of the C{sub 60} carbon clusters observed in the molecular beam experiments could be explained by the truncated icosahedral (or soccer ball) form. The name given to this cluster, buckminsterfullerene, led to the use of the term fullerenes for the family of hollow-cage carbon clusters made up of even numbers of triply coordinated carbons arranged with 12 pentagonal rings and an almost arbitrary number of hexagonal rings. More than a decade later, we still lack a completely satisfying understanding of the fundamental chemistry that takes place during fullerene formation. Most current models for fullerene formation require a facile mechanism for ring rearrangement in the fullerene structure, but the simplest proposed mechanisms are believed to have unrealistically high activation barriers. In recent research calculations have suggested that atomic carbon in the reaction mixture could act as a catalyst and allow substantially lower activation barriers for fullerene annealing. This article discusses the background for this research and other adjunct research. 14 refs.

  12. Egg Formation in Lepidoptera

    PubMed Central

    Telfer, William H.

    2009-01-01

    Reproductive biology in the Twentieth Century produced comprehensive descriptions of the mechanisms of egg formation in most of the major orders of insects. While many general principles of ovarian development and physiology emerged, every order turned out to have a set of its own special motifs. Discovery of the lepidopteran motifs is summarized in this essay. The emphasis is on developmental mechanisms, beginning with the early growth and differentiation of female germ cells and ending, after many turns in morphogenesis, physiology and biosynthesis, with eggs that are filled with yolk and encased in chorions. Examples of uniquely lepidopteran traits include the cellular composition of ovarian follicles, the number of tubular ovarioles in which they mature, the functions of cell-to-cell junctional complexes in their maturation, their use of glycosaminoglycans to maintain intercellular patency during vitellogenesis, the role of proton and calcium pumps in their ion physiology, a separate postvitellogenic period of water and inorganic ion uptake, and the fine structure and protein composition of their chorions. Discovery of this combination of idiosyncracies was based on advances in the general concepts and techniques of cell and molecular biology and on insights borrowed from studies on other insects. The lepidopteran ovary in turn has contributed much to the understanding of egg formation in insects generally. PMID:20050770

  13. The Planet Formation Imager

    NASA Astrophysics Data System (ADS)

    Kraus, S.; Buscher, D. F.; Monnier, J. D.; PFI Science, the; Technical Working Group

    2014-04-01

    Among the most fascinating and hotly-debated areas in contemporary astrophysics are the means by which planetary systems are assembled from the large rotating disks of gas and dust which attend a stellar birth. Although important work is being done both in theory and observation, a full understanding of the physics of planet formation can only be achieved by opening observational windows able to directly witness the process in action. The key requirement is then to probe planet-forming systems at the natural spatial scales over which material is being assembled. By definition, this is the so-called Hill Sphere which delineates the region of influence of a gravitating body within its surrounding environment. The Planet Formation Imager project has crystallized around this challenging goal: to deliver resolved images of Hill-Sphere-sized structures within candidate planet-hosting disks in the nearest star-forming regions. In this contribution we outline the primary science case of PFI and discuss how PFI could significantly advance our understanding of the architecture and potential habitability of planetary systems. We present radiation-hydrodynamics simulations from which we derive preliminary specifications that guide the design of the facility. Finally, we give an overview about the interferometric and non-interferometric technologies that we are investigating in order to meet the specifications.

  14. Bubble formation in microgravity

    NASA Technical Reports Server (NTRS)

    Antar, Basil N.

    1994-01-01

    Two KC-135 flight campaigns have been conducted to date which are specifically dedicated to study bubble formation in microgravity. The first flight was conducted during March 14-18, 1994, and the other during June 20-24, 1994. The results from the June 1994 flight have not been analyzed yet, while the results from the March flight have been partially analyzed. In the first flight three different experiments were performed, one with the specific aim at determining whether or not cavitation can take place during any of the fluid handling procedures adopted in the shuttle bioprocessing experiments. The other experiments were concerned with duplicating some of the procedures that resulted in bubble formation, namely the NCS filling procedure and the needle scratch of a solid surface. The results from this set of experiments suggest that cavitation did not take place during any of the fluid handling procedures. The results clearly indicate that almost all were generated as a result of the breakup of the gas/liquid interface. This was convincingly demonstrated in the scratch tests as well as in the liquid fill tests.

  15. Group Formation in Economics

    NASA Astrophysics Data System (ADS)

    Demange, Gabrielle; Wooders, Myrna

    2005-01-01

    Broad and diverse ranges of activities are conducted within and by organized groups of individuals, including political, economic and social activities. These activities have recently become a subject of intense interest in economics and game theory. Some of the topics investigated in this collection are models of networks of power and privilege, trade networks, co-authorship networks, buyer-seller networks with differentiated products, and networks of medical innovation and the adaptation of new information. Other topics are social norms on punctuality, clubs and the provision of club goods and public goods, research and development and collusive alliances among corporations, and international alliances and trading agreements. While relatively recent, the literature on game theoretic studies of group formation in economics is already vast. This volume provides an introduction to this important literature on game-theoretic treatments of situations with networks, clubs, and coalitions, including some applications.

  16. Galaxy evolution and formation

    NASA Technical Reports Server (NTRS)

    Cowie, Lennox L.; Lilly, Simon J.

    1990-01-01

    Results from the Hawaii imaging and spectroscopy deep survey are discussed. Cumulative galaxy counts now exceed 10 exp 6/deg. To B = 24 the bulk of these galaxies lie at low redshift. Flat spectrum sources constitute a fraction of about 30-40 percent of the sources at B = 24. There are not enough of these to explain the high number counts, but they are an exceedingly interesting population in their own right. It is argued that they are unlikely to lie at z of about 1, but could be either massive starbursters at z of about 2 - 3 or dwarf starbursting galaxies at very low redshift (less than approximately 0.1). In either case they constitute a major episode in galaxy formation.

  17. Frost formation with salt

    NASA Astrophysics Data System (ADS)

    Guadarrama-Cetina, J.; Mongruel, A.; González-Viñas, W.; Beysens, D.

    2015-06-01

    The formation of frost in presence of salt (NaCl) crystal is experimentally investigated on a hydrophobic surface. It presents several remarkable features due to the interplay of salty-water saturation pressure evolution, initially lower than the saturation pressure of ice and water, and the percolating propagation of ice dendrites from defects throughout the supercooled water droplet pattern. In particular, it is remarkable that nucleation of supercooled water and/or ice is prevented around the salty drop in a region of inhibited condensation where the substrate remains dry. As condensation proceeds, salt concentration decreases to eventually become lower than ice's, allowing ice dendrites to hit the salty drop. Salty water then melts ice but eventually freezes as an effect of dilution.

  18. DUST FORMATION IN MACRONOVAE

    SciTech Connect

    Takami, Hajime; Ioka, Kunihito; Nozawa, Takaya E-mail: kunihito.ioka@kek.jp

    2014-07-01

    We examine dust formation in macronovae (as known as kilonovae), which are the bright ejecta of neutron star binary mergers and one of the leading sites of r-process nucleosynthesis. In light of information about the first macronova candidate associated with GRB 130603B, we find that dust grains of r-process elements have difficulty forming because of the low number density of the r-process atoms, while carbon or elements lighter than iron can condense into dust if they are abundant. Dust grains absorb emission from ejecta with an opacity even greater than that of the r-process elements, and re-emit photons at infrared wavelengths. Such dust emission can potentially account for macronovae without r-process nucleosynthesis as an alternative model. This dust scenario predicts a spectrum with fewer features than the r-process model and day-scale optical-to-ultraviolet emission.

  19. Galaxy formation by dust

    NASA Technical Reports Server (NTRS)

    Wang, Boqi; Field, Goerge B.

    1989-01-01

    It has been known since the early 1940's that radiation can cause an instability in the interstellar medium. Absorbing dust particles in an isotropic radiation field shadow each other by a solid angle which is inversely proportional to the square of the distance between the two particles, leading to an inverse-square attractive force - mock gravity. The effect is largest in an optically thin medium. Recently Hogan and White (HW, hereafter) proposed that if the pre-galactic universe contained suitable sources of radiation and dust, instability in the dust distribution caused by mock gravity may have led to the formation of galaxies and galaxy clusters. In their picture of a well-coupled dust-gas medium, HW show that mock gravity begins to dominate gravitational instability when the perturbation becomes optically thin, provided that the radiation field at the time is strong enough. The recent rocket observation of the microwave background at submillimeter wavelengths by Matsumoto et al. might be from pre-galactic stars, the consequence of the absorption of ultraviolet radiation by dust, and infrared reemission which is subsequently redshifted. HW's analysis omits radiative drag, incomplete collisional coupling of gas and dust, finite dust albedo, and finite matter pressure. These effects could be important. In a preliminary calculation including them, the authors have confirmed that mock gravitational instability is effective if there is a strong ultraviolet radiation at the time, but any galaxies that form would be substantially enriched in heavy elements because the contraction of the dust is more rapid than that of the gas. Moreover, since the dust moves with supersonic velocity through the gas soon after the perturbation becomes optically thin, the sputtering of dust particles by gas is significant, so the dust could disappear before the instability develops significantly. They conclude that the mock gravity by dust is not important in galaxy formations.

  20. Medusae Fossae Formation

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 16 April 2002) The Science This THEMIS visible image was acquired near 11o N, 159o W (201o E) and shows examples of the remarkable variations that can be seen in the erosion of the Medusae Fossae Formation. This Formation is a soft, easily eroded deposit that extends for nearly 1,000 km along the equator of Mars. In this region, like many others throughout the Medusae Fossae Formation, the surface has been eroded by the wind into a series of linear ridges called yardangs. These ridges generally point in direction of the prevailing winds that carved them, and demonstrate the power of martian winds to erode the landscape of Mars. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Within this single image it is possible to see differing amounts of erosion and stripping of layers in the Medusae Fossae Formation. Near the bottom (southern) edge of the image a rock layer with a relatively smooth upper surface covers much of the image. Moving upwards (north) in the image this layer becomes more and more eroded. At first there are isolated regions where the smooth unit has been eroded to produce sets of parallel ridges and knobs. Further north these linear knobs increase in number, and only small, isolated patches of the smooth upper surface remain. Finally, at the top of the image, even the ridges have been removed, exposing the remarkably smooth top of hard, resistant layer below. This sequence of layers with differing hardness and resistance to erosion is common on Earth and on Mars, and suggests significant variations in the physical properties, composition, particle size, and/or cementation of these martian layers. As is common throughout the Medusae Fossae Formation, very few impact craters are visible, indicating that the surface exposed is relatively young, and that the process of erosion may be active today. The Story 'Yardang!' Now, that may seem like a peculiar-sounding curse word, but nobody would get in trouble for using it. A yardang is one of the very cool-sounding words geologists use to describe long, irregular features like the ones seen in this image. Yardangs are grooved, furrowed ridges that form as the wind erodes away weakly cemented material in the region. Rippling across the surface, yardangs tell the story of how the powerful Martian wind carved the surface into such a gorgeous pattern over time. (Don't miss clicking on the above image to see a detailed view, in which the beauty and almost dance-like symmetry of the waving terrain pops out in highly compelling, three-dimensional texture.) It may be easy to see which way the wind blows in this area, since these streamlined features point in the direction of prevailing winds. But how can geologists understand the various kinds of terrain seen here? First, they have to study the different patterns of erosion, looking closely at how the wind has stripped off certain layers and not others. Want to be a geologist yourself? Start at the bottom of the image and scroll upward, and see how the relatively smooth, higher terrain toward the south gradually becomes more and more eroded. Moving up the image, at first you?ll see only a few, isolated regions of parallel ridges and knolls. Go a little farther north with your eyes (toward the center of the image), and you?ll see how these linear knobs really get going! Once you get to the top of the image, only patches of these grooved ridges remain, leaving an incredibly smooth, wind-scrubbed surface behind. You know this layer has to be made of pretty hard material, because it seems impervious to further erosion. Geologists studying Mars can compare these Martian yardangs to examples found on Earth, such as those in the Lut desert of Iran. Humans have even been known to use the wind as their inspiration, sculpting the shape of yardangs themselves. The famous sphynx at Giza in Egypt is thought to be a yardang that's been whittled

  1. Formative Assessment Probes: Is It a Rock? Continuous Formative Assessment

    ERIC Educational Resources Information Center

    Keeley, Page

    2013-01-01

    A lesson plan is provided for a formative assessment probe entitled "Is It a Rock?" This probe is designed for teaching elementary school students about rocks through the use of a formative assessment classroom technique (FACT) known as the group Frayer Model. FACT activates students' thinking about a concept and can be used to…

  2. Large Format Radiographic Imaging

    SciTech Connect

    J. S. Rohrer; Lacey Stewart; M. D. Wilke; N. S. King; S. A Baker; Wilfred Lewis

    1999-08-01

    Radiographic imaging continues to be a key diagnostic in many areas at Los Alamos National Laboratory (LANL). Radiographic recording systems have taken on many form, from high repetition-rate, gated systems to film recording and storage phosphors. Some systems are designed for synchronization to an accelerator while others may be single shot or may record a frame sequence in a dynamic radiography experiment. While film recording remains a reliable standby in the radiographic community, there is growing interest in investigating electronic recording for many applications. The advantages of real time access to remote data acquisition are highly attractive. Cooled CCD camera systems are capable of providing greater sensitivity with improved signal-to-noise ratio. This paper begins with a review of performance characteristics of the Bechtel Nevada large format imaging system, a gated system capable of viewing scintillators up to 300 mm in diameter. We then examine configuration alternatives in lens coupled and fiber optically coupled electro-optical recording systems. Areas of investigation include tradeoffs between fiber optic and lens coupling, methods of image magnification, and spectral matching from scintillator to CCD camera. Key performance features discussed include field of view, resolution, sensitivity, dynamic range, and system noise characteristics.

  3. The formation of dew

    NASA Astrophysics Data System (ADS)

    Beysens, D.

    Dew is the condensation into liquid droplets of water vapor on a substrate. The presence of a substrate is the origin of the peculiarities and richness of the phenomenon. We review the aspects related to heterogeneous nucleation and subsequent growth of water droplets. A key point is the drop interaction through drop fusion or coalescence, which leads to scaling in the growth and gives universality to the process. The effects of substrate heterogeneity and gravity effects are also considered. Coalescence events lead to temporal and spatio-temporal fluctuations in the substrate coverage, drop configuration, etc., which give rise to a very peculiar dynamics. When the substrate is a liquid or a liquid crystal, the drop pattern can exhibit special spatial orders, such as crystalline, hexatic phases and fractal contours. And condensation on a solid substrate near its melting point can make the drop jump. The applications of monitoring dew formation are manyfold. Examples can be found in nanoelectronics and optics (vapor deposition and thin films), medicine (sterilization process), agriculture (green houses). We here discuss in greater details the production of clean water by "atmospheric wells".

  4. Nuclear ``pasta'' formation

    NASA Astrophysics Data System (ADS)

    Schneider, A. S.; Horowitz, C. J.; Hughto, J.; Berry, D. K.

    2013-12-01

    The formation of complex nonuniform phases of nuclear matter, known as nuclear pasta, is studied with molecular dynamics (MD) simulations containing 51200 nucleons. A phenomenological nuclear interaction is used that reproduces the saturation binding energy and density of nuclear matter. Systems are prepared at an initial density of 0.10fm-3 and then the density is decreased by expanding the simulation volume at different rates to densities of 0.01fm-3 or less. An originally uniform system of nuclear matter is observed to form spherical bubbles (“swiss cheese”), hollow tubes, flat plates (“lasagna”), thin rods (“spaghetti”) and, finally, nearly spherical nuclei with decreasing density. We explicitly observe nucleation mechanisms, with decreasing density, for these different pasta phase transitions. Topological quantities known as Minkowski functionals are obtained to characterize the pasta shapes. Different pasta shapes are observed depending on the expansion rate. This indicates nonequilibrium effects. We use this to determine the best ways to obtain lower energy states of the pasta system from MD simulations and to place constraints on the equilibration time of the system.

  5. Acromioclavicular joint cyst formation.

    PubMed

    Hiller, Andrew D; Miller, Joshua D; Zeller, John L

    2010-03-01

    Acromioclavicular joint (ACJ) cysts are an uncommon and unusual sequela associated with shoulder pathophysiology. The majority of literature on ACJ cysts consists of individual case reports with no definitive literature review currently available. In addition to a comprehensive literature review, four clinical cases are presented in this report. First described by Craig (1984), a total of 41 cases have been previously reported in the literature. Of these cases, five occurred with the rotator cuff musculature intact. The remaining 36 cases of ACJ cysts occurred in patients with a complete tear/avulsion of the rotator cuff. Previous attempts at compiling a complete record of all reported cases have combined several distinct conditions into a single category. This article presents two distinct etiologies for the pathogenesis of ACJ cyst formation. In the presence of an intact rotator cuff, a Type 1 cyst can form superficially and be limited to the ACJ. Following a massive or traumatic tear of the rotator cuff, mechanical instability of the humeral head can cause a deterioration of the inferior acromioclavicular capsule (cuff tear arthropathy) and an overproduction of synovial fluid. Overtime, a "geyser" of fluid can form between the glenohumeral and the ACJ, forming a Type 2 cyst. This differentiation and categorization is essential for appropriate classification and treatment. PMID:20069645

  6. Bead lightning formation

    SciTech Connect

    Ludwig, G.O.; Saba, M.M.F.

    2005-09-15

    Formation of beaded structures in triggered lightning discharges is considered in the framework of both magnetohydrodynamic (MHD) and hydrodynamic instabilities. It is shown that the space periodicity of the structures can be explained in terms of the kink and sausage type instabilities in a cylindrical discharge with anomalous viscosity. In particular, the fast growth rate of the hydrodynamic Rayleigh-Taylor instability, which is driven by the backflow of air into the channel of the decaying return stroke, dominates the initial evolution of perturbations during the decay of the return current. This instability is responsible for a significant enhancement of the anomalous viscosity above the classical level. Eventually, the damping introduced at the current channel edge by the high level of anomalous viscous stresses defines the final length scale of bead lightning. Later, during the continuing current stage of the lightning flash, the MHD pinch instability persists, although with a much smaller growth rate that can be enhanced in a M-component event. The combined effect of these instabilities may explain various aspects of bead lightning.

  7. Formation of nuclear heterochromatin

    PubMed Central

    Guetg, Claudio; Santoro, Raffaella

    2012-01-01

    Establishment and inheritance of heterochromatic states is critical in maintaining genome integrity and gene expression state. The elucidation of the mechanisms implicated in these processes is fundamental to understand the control of epigenetic regulation of the genome. Recently, the nucleolus emerged as an important component of the nuclear architecture. Although the nucleolus is the most active site of cellular transcription, it is also an attractive compartment for nuclear heterochromatic regions, such as pericentric repeats, inactive X chromosome and regions with low gene density significantly enriched in repressed genes. The coexistence of euchromatic and heterochromatic rRNA genes in each cell reflects these two opposite functions of the nucleolus. An epigenetic network that is controlled by NoRC complex establishes and maintains rDNA heterochromatin. It is here discussed how heterochromatic rRNA genes and the associated epigenetic regulatory activities might mediate formation and inheritance of nuclear heterochromatic regions. Finally, we propose that the analysis of the components of heterochromatic rRNA genes will be not only relevant to understand the general composition of heterochromatin but has the potential to provide important and novel insights of how nuclear heterochromatic structures are established and inherited. PMID:22735386

  8. Bubble formation in microgravity

    NASA Technical Reports Server (NTRS)

    Antar, Basil N.

    1996-01-01

    An extensive experimental program was initiated for the purpose of understanding the mechanisms leading to bubble generation during fluid handling procedures in a microgravity environment. Several key fluid handling procedures typical for PCG experiments were identified for analysis in that program. Experiments were designed to specifically understand how such procedures can lead to bubble formation. The experiments were then conducted aboard the NASA KC-135 aircraft which is capable of simulating a low gravity environment by executing a parabolic flight attitude. However, such a flight attitude can only provide a low gravity environment of approximately 10-2go for a maximum period of 30 seconds. Thus all of the tests conducted for these experiments were designed to last no longer than 20 seconds. Several experiments were designed to simulate some of the more relevant fluid handling procedures during protein crystal growth experiments. These include submerged liquid jet cavitation, filling of a cubical vessel, submerged surface scratch, attached drop growth, liquid jet impingement, and geysering experiments. To date, four separate KC-135 flight campaigns were undertaken specifically for performing these experiments. However, different experiments were performed on different flights.

  9. Formation of "bound

    NASA Astrophysics Data System (ADS)

    Nowak, K.; Kästner, M.; Miltner, A.

    2009-04-01

    During degradation of organic pollutants in soil, metabolites, microbial biomass, CO2and "bound" residues ("non-extractable" residues in soil organic matter) are formed. Enhanced transformation of these contaminants into "bound" residues has been proposed as an alternative remediation method for polluted soils. However, this kind of residues may pose a potential risk for the environment due to their chemical structure and possible remobilization under different conditions. Therefore particular attention is given actually to "bound" residues. Part of these non-extractable residues may be "biogenic," because microorganisms use the carbon from the pollutant to form their biomass components (fatty acids, amino acids, amino sugars), which subsequently may be incorporated into soil organic matter. Furthermore, the CO2 originating from mineralization of xenobiotics, can be re-assimilated by microorganisms and also incorporated into "biogenic residue". The hazard posed by "bound" residues may be overestimated because they are "biogenic" (contain microbial fatty acids and amino acids). The knowledge about the pathways of "biogenic residue" formation is necessary for a proper assessment of the fate of tested pollutants and their turnover in the soil environment. Moreover, these data are needed to establish the realistic degradation rates of the contaminants in soil. The main objectives of this study are: to quantify the extent of "biogenic residue" (fatty acids, amino acids, amino sugars) formation during the degradation of a model pollutant (2,4-dichlorophenoxyacetic acid = 2,4-D) and during CO2 assimilation by microorganisms and to evaluate which components are mainly incorporated into "bound" residues. To investigate the extent of "biogenic residue" formation in soil during the degradation of 2,4-D, experiments with either 14C-U-ring and 13C6-2,4-D or carboxyl-14C 2,4-D were performed. The incubation experiments were performed according to OECD test guideline 307, in the dark, at constant temp 20Ë? C (+/-2Ë? C) and with intermittent aeration. During incubation, the mineralization was quantified and soil samples were analyzed for the presence of both "biogenic residues" and remaining 2,4-D. Mineralization of 2,4-D in both experiments was very high. However, the 14CO2 evolution was higher from carboxyl-14C 2,4-D than from 14C-ring 2,4-D. After 7 days of incubation, 30% of initial amount of 14C in soil contaminated with 14C-ring 2,4-D was mineralized, whereas 40% of total radioactivity was evolved as CO2after 4 days from soil incubated with 14C-carboxyl 2,4-D. The amount of extractable 2,4-D residues was very low in both experiments (14C-ring 2,4-D: 2% and 14C-carboxyl 2,4-D: 1%). The soil incubated with 14C-ring 2,4-D contained 60% of "non-extractable" residues of 2,4-D after 7 days, while the amount of these residues in soil contaminated with 14C-carboxyl 2,4-D reached 50% of the initial radioactivity in the tested system 4 days after application. More "biogenic residues" were formed in soil spiked with 14C-U-ring 2,4-D (10%) than in soil with carboxyl 14C 2,4-D (7%). Both 2,4-D and CO2-derived C were incorporated mainly into microbial amino acids (9.5% at day 7 and 7.0% at day 4, respectively). After 7 days of incubation, 0.5% of initial applied radioactivity in system was found in microbial lipids in the soil contaminated with 14C-ring 2,4-D. Only 0.1% of the total radioactivity was incorporated into lipids in soil treated with 14C-carboxyl 2,4-D on day 4 after application. Thin Layer Chromatography identified the microbial lipids containing the radioactivity as phosphatidylethanolamine, a phospholipid typical for microorganisms. The amount of microbial lipids (which corresponds to phospholipids) in both cases decreased with time; this can be explained by the death of the microbial biomass. To the best of our knowledge, this is the first report on the formation of &qu

  10. Layer Formation in Semiconvection

    E-print Network

    Joseph A. Biello

    2001-02-20

    Layer formation in a thermally destabilized fluid with stable density gradient has been observed in laboratory experiments and has been proposed as a mechanism for mixing molecular weight in late stages of stellar evolution in regions which are unstable to semiconvection. It is not yet known whether such layers can exist in a very low viscosity fluid: this work undertakes to address that question. Layering is simulated numerically both at high Prandtl number (relevant to the laboratory) in order to describe the onset of layering intability, and the astrophysically important case of low Prandtl number. It is argued that the critical stability parameter for interfaces between layers, the Richardson number, increases with decreasing Prandtl number. Throughout the simulations the fluid has a tendency to form large scale flows in the first convecting layer, but only at low Prandtl number do such structures have dramatic consequences for layering. These flows are shown to drive large interfacial waves whose breaking contributes to significant mixing across the interface. An effective diffusion coefficient is determined from the simulation and is shown to be much greater than the predictions of both an enhanced diffusion model and one which specifically incorporates wave breaking. The results further suggest that molecular weight gradient interfaces are ineffective barriers to mixing even when specified as initial conditions, such as would arise when a compositional gradient is redistributed by another mechanism than buoyancy, such as rotation or internal waves.

  11. FORMATION OF SECONDARY ORGANIC AEROSOL

    EPA Science Inventory

    (1) Gas-phase chemistry. With the clear and profound effect of the VOC/NOx ratio on SOA formation, we will augment gas-phase VOC oxidation mechanisms in atmospheric models to account for the effect of NOx level on the mechanism of SOA formation; (2) Revis...

  12. Portable File Format (PFF) specifications.

    SciTech Connect

    Dolan, Daniel H.,

    2015-02-01

    Created at Sandia National Laboratories, the Portable File Format (PFF) allows binary data transfer across computer platforms. Although this capability is supported by many other formats, PFF files are still in use at Sandia, particularly in pulsed power research. This report provides detailed PFF specifications for accessing data without relying on legacy code.

  13. The Algebra Formative Assessment Project

    E-print Network

    Ferguson, Thomas S.

    Meetings · Discuss, Research, Plan, Implement, Debrief, Revise · Common Core State Standards · Standards the MDTP and common formative assessments to drive instruction. These steps will prepare the students diagnostic and formative assessment process including the use of the Math Diagnostic Testing Project (MDTP

  14. SAS FORMATS: USES AND ABUSES

    EPA Science Inventory

    SAS formats are a very powerful tool. They allow you to display the data in a more readable manner without modifying it. Formats can also be used to group data into categories for use in various procedures like PROC FREQ, PROC TTEST, and PROC MEANS (as a class variable). As ...

  15. Flowstone Formations in Jewel Cave

    USGS Multimedia Gallery

    Jewel Cave is currently the 3rd most extensive cave network in the world. It is believed to have formed completely underwater, thus leading to the extensive coating of calcite crystals. In the center of the image, a formation known as flowstone can be seen. Flowstone is a type of calcite formation ...

  16. Motivating Students through Formative Feedback

    ERIC Educational Resources Information Center

    Mauch, Lois

    2007-01-01

    Technology tools that are used to help apply standards and benchmarks motivate physical educators to use new methods of teaching, and create new ways to provide students with direct formative feedback, the number one motivator for students. Direct formative feedback refers to verbal communication between the teacher and/or parent and student. The…

  17. The Principal as Formative Coach

    ERIC Educational Resources Information Center

    Nidus, Gabrielle; Sadder, Maya

    2011-01-01

    Formative coaching, an approach that uses student work as the foundation for mentoring and professional development, can help principals become more effective instructional leaders. In formative coaching, teaches and coaches analyze student work to determine next steps for instruction. This article shows how a principal can use the steps of the…

  18. Star formation in the multiverse

    SciTech Connect

    Bousso, Raphael; Leichenauer, Stefan

    2009-03-15

    We develop a simple semianalytic model of the star formation rate as a function of time. We estimate the star formation rate for a wide range of values of the cosmological constant, spatial curvature, and primordial density contrast. Our model can predict such parameters in the multiverse, if the underlying theory landscape and the cosmological measure are known.

  19. The Apennine Bench Formation revisited

    NASA Technical Reports Server (NTRS)

    Spudis, P. D.; Hawke, B. R.

    1985-01-01

    The Apennine Bench Formation consists of pre-mare light plains materials that crop out south of the crater Archimedes, inside the Imbrium basin. This material was ascribed to either impact or volcanic origins. The characteristics of Apollo 15 KREEP basalts and the Apennine Bench Formation are reviewed to determine whether their characteristics are compatible with a volcanic origin.

  20. Cloud formation in giant planets

    E-print Network

    Christiane Helling

    2007-11-23

    We calculate the formation of dust clouds in atmospheres of giant gas-planets. The chemical structure and the evolution of the grain size distribution in the dust cloud layer is discussed based on a consistent treatment of seed formation, growth/evaporation and gravitational settling. Future developments are shortly addressed.

  1. Machining -Chip Formation, Cutting Fluids,

    E-print Network

    Colton, Jonathan S.

    Machining - Chip Formation, Cutting Fluids, Vibration, Chatter, ver. 1 ME 6222: Manufacturing workpiece crack ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 9 #12;AISI 4340: V Prof. J.S. Colton © GIT 2009 10 ­ cracks extend into workpiece #12;Formation of Built up Edge (BUE

  2. SAS FORMATS: USES AND ABUSES

    EPA Science Inventory

    SAS formats are a very powerful tool. They allow you to display the data in a more readable manner without modifying it. Formats can also be used to group data into categories for use in various procedures like PROC FREQ, PROC TTEST, and PROC MEANS (as a class variable). As w...

  3. Triglycerides and gallstone formation.

    PubMed

    Smelt, A H M

    2010-11-11

    Changes in bile acid (BA) metabolism and gallbladder function are critical factors in the pathogenesis of gallstones. Patients with hypertriglyceridemia (HTG) - often overweight and insulin resistant - are at risk for gallstone disease. The question arises whether HTG itself contributes to gallstone formation or whether gallstone disease only associates with this disorder. Triglycerides are formed in response to fluxes of non-esterified fatty acids and glucose. Hypertriglyceridemia results from either overproduction of triglycerides by the liver, impaired lipolysis or a combination of both. Hyperinsulinemia, as observed in the insulin resistant state, stimulates very low-density lipoprotein (VLDL)-triglyceride synthesis. Peroxisome proliferator-activated receptors (PPARs), liver X receptors (LXRs), farnesoid X receptor (FXR) and hepatocyte nuclear factor 4? (HNF4?) are the nuclear receptors involved in the regulation of lipogenesis. Microsomal triglyceride transfer protein (MTP) is involved in the production of VLDL and its activation is also under control of transcription factors as FXR and Forkhead box-O1 (FoxO1). Triglyceride and BA metabolism are linked. There is an inverse relationship between bile acid fluxes and pool size and VLDL production and SHP (small heterodimer partner) and FXR are the link between BAs and TG metabolism. BAs are also ligands for FXR and G-protein-coupled receptors, such as TGR5. FXR activation by BAs suppresses the expression of MTP, transcription factor sterol regulatory element binding protein (SREBP)-1c and other lipogenic genes. LXRs stimulate lipogenesis whereas FXRs inhibit the metabolic process. Synthesis of BAs from cholesterol occurs either via the classical pathway (7?-hydroxylation of cholesterol; CYP7A1) or via the alternate pathway (CYP39A1 or CYP7B1). BAs induce FXR, which inhibits CYP7A1 transcription by activation of SHP and inhibition of HNF4? transactivation. Bile composition (supersaturation with cholesterol), gallbladder dysmotility, inflammation, hypersecretion of mucin gel in the gallbladder and slow large intestinal motility and increased intestinal cholesterol absorption may contribute to the pathogenesis of cholesterol gallstones. In HTG patients supersaturated bile may be related to the presence of obesity rather than to HTG itself. Contraction and relaxation of the gallbladder are regulated by neuronal, hormonal and paracrine factors. Postprandial gallbladder emptying is regulated by cholecystokinin (CCK). Poor postprandial gallbladder contraction may be due to the magnitude of the CCK response and to the amount of CCK receptors in the gallbladder smooth muscle cells. In the fasting state gallbladder motility is associated with the intestinal migrating motor complex (MMC) activity and with elevated plasma motilin levels. Fibroblast growth factor (FGF19), produced on arrival of bile acids in the ileum, is also important for gallbladder motility. Gallbladder motility is impaired in HTG patients compared to BMI matched controls. There is evidence that the gallbladder in HTG is less sensitive to CCK and that this sensitivity improves after reversal of high serum TG levels by use of TG lowering agents. In hypertriglyceridemia TG lowering therapy (fibrates or fish-oil) is essential to prevent cardiovascular disease and pancreatitis. Fibrates, however, also increase the risk for cholelithiasis by increasing biliary cholesterol saturation and by reduction of bile acid synthesis. On the other hand fish-oil decreases biliary cholesterol saturation. Fish-oil may increase bile acid synthesis by activation of 7alpha-hydroxylase and may inhibit VLDL production and secretion through activation of nuclear factors and increased apoB degradation. In HTG patients, gallbladder motility improves during bezafibrate as well as during fish-oil therapy. The question remains whether improvement of gallbladder motility and increased lithogenicity of bile by bezafibrate therapy counteract each other or still result in gallstone formation in HTG patients. PMID:20699090

  4. Microdiamonds Formation During

    NASA Astrophysics Data System (ADS)

    Ogasawara, Y.

    2005-12-01

    The previous studies on the Kokchetav UHPM rocks by the authors group demonstrated the following subjects on the formation of microdiamonds. Microdiamond is highly abundant (max. ca. 2700carat/ton) in dolomite marble that has diopside (with K-bearing silicate lamella)-dolomite-garnet assemblage and was stable at XCO2=0.1. The microdiamonds in dolomite marble are classified into 3- types; S, R and T. The dominant type S (ca. 80%) indicates that it grew at two stages, the core and rim stages. R-type grew mainly at the core stage, and T-type grew at the rim stage (Ishida et al., 2003; Yoshioka & Ogasawara, 2005). One of the possible source of carbon for the 2nd stage growth is a fluid during UHPM. Some domains of dolomite marble contacting with dolomitic marble lack diamond, and indicate are lower XCO2 than diamond-bearing marble. No diamond occurs in dolomitic marble that is a product of strong H2O-rich fluid effect during UHPM (Ogasawara & Aoki, 2005); Ti-clinohumite-aragonite corresponds to extremely low-XCO2 (=<0.01), and the TiO2 carrier could be a H2O-rich fluid. Hydroxyl in lamellar-free diopside was confirmed as > 850ppm (Kikuchi & Ogasawara, in press). Low XCO2 condition corresponds to relatively oxidized conditions (Ogasawara et al., 2000). Extremely low-XCO2 conditions are unsuitable for diamond formation. A small amount of microdiamond (61 grains) occurs in diopside (with lamellar) in some layers of titanite-bearing calcite marble. Other domain contains titanite with coesite exsolution and the precursor silica-excess composition of titanite gave the minimum pressure as 6 GPa (Ogasawara et al., 2002). The presence of titanite (including relic aragonite + rutile) indicates very low-XCO2 (ca. 0.02). All grains of microdiamond are similar to R-type in morphology. No evidence for the 2nd stage diamond growth was observed. No diamond occurs in garnet- clinopyroxene rock like _gskarns_h. This rock has UHP evidence; coesite exsolution in titanite and K- bearing-silicate lamella in clinopyroxene, and is a product of the metasomatism (indicating very low XCO2) under UHP. The lack of diamond is consistent with other diamond-free carbonate rocks that were stable under extremely low- XCO2. The 2nd abundant diamond-bearing rock is pelitic gneiss. The characteristic features of microdiamonds show the strong contrast with those in dolomite marble. The dominant morphology is rounded to cuboidal form with rugged surface (> 80%); this corresponds to R- type. S-type is rare in pelitic gneiss. Morphology of microdiamond is controlled by growth and/or dissolution. Rounded grain with smooth surface may show the resorption after diamond growth. The absence of S-type diamond is a great difference from the microdiamond in dolomite marble, and indicates that fluid played different roles in both two diamond-bearing rocks; 1) carbon dissolved into aqueous fluid in pelitic gneiss, and 2) carbon precipitated from fluid to form microdiamond at the 2nd stage in dolomite marble. The microdiamond formed at the 2nd stage might be closely related to UHPM fluid. A model for fluid evolution from CO2-rich to H2O-rich during prograde stage can explain the metamorphic history of the Kokchetav carbonate rocks. Such UHPM fluid evolution may be caused by the dehydration in gneisses/eclogites surrounding the carbonate. Summarizing these, ``Intraslab UHP metasomatism" could be proposed. References: Ishida et al. (2003) J. Metamorphic Geol., 21. Kikuchi & Ogasawara (in press) GSA Special Papers. Ogasawara et al. (2000) Island Arc, 9, 400-416. Ogasawara et al. (2002) Am. Min., 87, 454-461. Ogasawara & Aoki (2005) Int. Geol. Rev., 47 (in press). Yoshioka & Ogasawara (2005) Int. Geol. Rev., 47, 703-715.

  5. Formation of Giant Planets

    NASA Astrophysics Data System (ADS)

    Lissauer, J. J.; Stevenson, D. J.

    The observed properties of giant planets, models of their evolution, and observations of protoplanetary disks provide constraints on the formation of gas giant planets. The four largest planets in our solar system contain considerable quantities of hydrogen and helium; these gases could not have condensed into solid planetesimals within the protoplanetary disk. Jupiter and Saturn are mostly hydrogen and helium, but have larger abundances of heavier elements than does the Sun. Neptune and Uranus are primarily composed of heavier elements. The transiting extrasolar planet HD149026b, which is slightly more massive than Saturn, appears to have comparable amounts of light gases and heavy elements. The other observed transiting exoplanets are primarily hydrogen and helium, but may contain supersolar abundances of heavy elements. Spacecraft flybys and observations of satellite orbits provide estimates of the gravitational moments of the giant planets in our solar system, which in turn provide information on the internal distribution of matter within Jupiter, Saturn, Uranus, and Neptune. Atmospheric thermal structure and heat flow measurements constrain the interior temperatures of these planets. Internal processes may cause giant planets to become more compositionally differentiated or alternatively more homogeneous; high-pressure laboratory experiments provide data useful for modeling these processes. The preponderance of evidence supports the core nucleated gas accretion model. According to this model, giant planets begin their growth by the accumulation of small solid bodies, as do terrestrial planets. However, unlike terrestrial planets, the giant planet cores grow massive enough to accumulate substantial amounts of gas before the protoplanetary disk dissipates. The primary question regarding the core nucleated growth model is under what conditions can planets develop cores sufficiently massive to accrete gas envelopes within the lifetimes of gaseous protoplanetary disks.

  6. Medusae Fossae Formation

    NASA Technical Reports Server (NTRS)

    1998-01-01

    An exotic terrain of wind-eroded ridges and residual smooth surfaces are seen in one of the highest resolution images ever taken of Mars from orbit. The Medusae Fossae formation is believed to be formed of the fragmental ejecta of huge explosive volcanic eruptions. When subjected to intense wind-blasting over hundreds of millions of years, this material erodes easily once the uppermost tougher crust is breached. In the Mars Orbiter Camera (MOC) image shown on the right, the crust, or cap rock, can be seen in the upper right part of the picture. The finely-spaced ridges are similar to features on Earth called yardangs, which are formed by intense winds plucking individual grains from, and by wind-driven sand blasting particles off, sedimentary deposits.

    The MOC image was taken on October 30, 1997 at 11:05 AM PST, shortly after the Mars Global Surveyor spacecraft's 31st closest approach to Mars. The image covers an area 3.6 X 21.5 km (2.2 X 13.4 miles) at 3.6 m (12 feet) per picture element--craters only 11 m (36 feet, about the size of a swimming pool) across can be seen. The context image (left; the best Viking view of the area; VO 1 387S34) has a resolution of 240 m/pixel, or 67 times lower resolution than the MOC frame.

    Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  7. Physics of primordial star formation

    NASA Astrophysics Data System (ADS)

    Yoshida, Naoki

    2012-09-01

    The study of primordial star formation has a history of nearly sixty years. It is generally thought that primordial stars are one of the key elements in a broad range of topics in astronomy and cosmology, from Galactic chemical evolution to the formation of super-massive blackholes. We review recent progress in the theory of primordial star formation. The standard theory of cosmic structure formation posits that the present-day rich structure of the Universe developed through gravitational amplification of tiny matter density fluctuations left over from the Big Bang. It has become possible to study primordial star formation rigorously within the framework of the standard cosmological model. We first lay out the key physical processes in a primordial gas. Then, we introduce recent developments in computer simulations. Finally, we discuss prospects for future observations of the first generation of stars.

  8. Double layer formation. [in plasma

    NASA Technical Reports Server (NTRS)

    Singh, N.

    1982-01-01

    An investigation is conducted of the plasma processes which occur during the formation of a double layer in response to an applied initial electric field, when triggered by a current in the plasma. The important feature of the formation process was the creation of an ion-rich plasma-density cavity. The positive space charge of the cavity was shielded by induction of a negative space charge on the low potential side of the cavity, giving rise to the formation of a fully developed double layer. The shielding was complete only when the electron current from the low potential side exceeded the electron thermal current. It was found that during the formation of double layers counterstreaming electrons are generated. Moreover, transient double layers with reverse polarity also occur during this phase. Thus, the recurring formation of double layers can give rise to flickering double layers.

  9. Galaxy Formation and Dark Matter

    E-print Network

    Joseph Silk

    2006-03-08

    The challenge of dark matter may be addressed in two ways; by studying the confrontation of structure formation with observation and by direct and indirect searches. In this review, I will focus on those aspects of dark matter that are relevant for understanding galaxy formation, and describe the outlook for detecting the most elusive component, non-baryonic dark matter. Galaxy formation theory is driven by phenomenology and by numerical simulations of dark matter clustering under gravity. Once the complications of star formation are incorporated, the theory becomes so complex that the brute force approach of numerical simulations needs to be supplemented by incorporation of such astrophysical processes as feedback by supernovae and by active galactic nuclei. I present a few semi-analytical perspectives that may shed some insight into the nature of galaxy formation.

  10. Formation of interstellar anions

    NASA Astrophysics Data System (ADS)

    Senent, Maria Luisa

    2012-05-01

    Formation of interstellar anions: M.L. Senent. The recent detection of negative charged species in the ISM1 has instigated enthusiasm for anions in the astrophysical community2. Many of these species are new and entail characterization. How they are formed in astrophysical sources is a question of major relevance. The anion presence in ISM was first predicted theoretically on the basis of electron affinities and on the negative linear chain molecular stabilities. Although very early, they were considered in astrochemical models3-4, their discovery is so recent because their abundances seem to be relatively low. These have to be understood in terms of molecular stabilities, reaction probabilities and radiative and collisional excitations. Then, we present our theoretical work on even carbon chains type Cn and CnH (n=2,4,6) focused to the understanding of anion abundances. We use highly correlated ab initio methods. We performed spectroscopic studies of various isomers that can play important roles as intermediates5-8. In previous papers9-10, we compared C2H and C2H- collisional rates responsible for observed line intensities. Actually, we study hydrogen attachment (Cn +H ? CnH and Cn- +H ? CnH-) and associative detachment processes (Cn- +H ? CnH +e-) for 2, 4 and 6 carbon atom chains11. [1] M.C.McCarthy, C.A.Gottlieb, H.Gupta, P.Thaddeus, Astrophys.J, 652, L141 (2006) [2] V.M.Bierbaum, J.Cernicharo, R.Bachiller, eds., 2011, pp 383-389. [3] A. Dalgarno, R.A. Mc Cray, Astrophys.J,, 181, 95 (1973) [4] E. Herbst E., Nature, 289, 656 (1981); [5] H.Massó, M.L.Senent, P.Rosmus, M.Hochlaf, J.Chem.Phys., 124, 234304 (2006) [6] M.L.Senent, M.Hochlaf, Astrophys. J. , 708, 1452(2010) [7] H.Massó, M.L.Senent, J.Phys.Chem.A, 113, 12404 (2009) [8] D. Hammoutene, M.Hochlaf, M.L.Senent, submitted. [9] A. Spielfiedel, N. Feautrier, F. Najar, D. ben Abdallah, F. Dayou, M.L. Senent, F. Lique, Mon.Not.R.Astron.Soc., 421, 1891 (2012) [10] F.Dumouchel, A, Spielfieldel , M.L.Senent, N.Feautrier, Chem. Phys. Lett., 533, 6 (2012) [11] M.L.Senent, M.Hochlaf, submitted

  11. Dynamics of rock varnish formation

    SciTech Connect

    Raymond, R. Jr.; Reneau, S.L.; Guthrie, G.D. Jr.; Bish, D.L.; Harrington, C.D.

    1991-01-01

    Our studies of rock varnish from the southwestern United States suggest that the Mn-phase in rock varnish has neither the chemistry nor the crystal structure of birnessite. Rather, the Mn-rich phase is non-crystalline and contains Ba, Ca, Fe, Al, and P. Unknowns concerning the formation of this non-crystalline Mn phase must be resolved before researchers are able to define chemical parameters of rock varnish formation based upon conditions of formation of the Mn phase. 6 refs., 9 figs.

  12. Formation of the Milky Way

    E-print Network

    J. E. Hesser; P. B. Stetson; W. E. Harris; M. Bolte; T. A. Smecker-Hane; D. A. Vandenberg; R. A. Bell; H. E. Bond; S. van den Bergh; R. D. McClure; G. G. Fahlman; H. B. Richer

    1997-03-08

    We review observational evidence bearing on the formation of a prototypical large spiral galaxy, the Milky Way. New ground- and space-based studies of globular star clusters and dwarf spheroidal galaxies provide a wealth of information to constrain theories of galaxy formation. It appears likely that the Milky Way formed by a combination of rapid, dissipative collapse and mergers, but the relative contributions of these two mechanisms remain controversial. New evidence, however, indicates that initial star and star cluster formation occurred simultaneously over a volume that presently extends to twice the distance of the Magellanic Clouds.

  13. Dissipative processes in galaxy formation.

    PubMed Central

    Silk, J

    1993-01-01

    A galaxy commences its life in a diffuse gas cloud that evolves into a predominantly stellar aggregation. Considerable dissipation of gravitational binding energy occurs during this transition. I review here the dissipative processes that determine the critical scales of luminous galaxies and the generation of their morphology. The universal scaling relations for spirals and ellipticals are shown to be sensitive to the history of star formation. Semiphenomenological expressions are given for star-formation rates in protogalaxies and in starbursts. Implications are described for elliptical galaxy formation and for the evolution of disk galaxies. PMID:11607396

  14. Antihydrogen Formation using Cold Plasmas

    SciTech Connect

    Madsen, N.; Bowe, P.D.; Hangst, J.S.; Amoretti, M.; Carraro, C.; Macri, M.; Testera, G.; Variola, A.; Amsler, C.; Johnson, I.; Pruys, H.; Regenfus, C.; Bonomi, G.; Bouchta, A.; Doser, M.; Kellerbauer, A.; Landua, R.; Cesar, C.L.; Charlton, M.; Joergensen, L.V.

    2004-10-20

    Antihydrogen, the antimatter counterpart of the hydrogen atom, can be formed by mixing cold samples of antiprotons and positrons. In 2002 the ATHENA collaboration succeeded in the first production of cold antihydrogen. By observing and imaging the annihilation products of the neutral, non-confined, antihydrogen atoms annihilating on the walls of the trap we can observe the production in quasi-real-time and study the dynamics of the formation mechanism. The formation mechanism strongly influences the final state of the formed antihydrogen atoms, important for future spectroscopic comparison with hydrogen. This paper briefly summarizes the current understanding of the antihydrogen formation in ATHENA.

  15. Treating tar sands formations with karsted zones

    DOEpatents

    Vinegar, Harold J. (Bellaire, TX); Karanikas, John Michael (Houston, TX)

    2010-03-09

    Methods for treating a tar sands formation are described herein. The tar sands formation may have one or more karsted zones. Methods may include providing heat from one or more heaters to one or more karsted zones of the tar sands formation to mobilize fluids in the formation. At least some of the mobilized fluids may be produced from the formation.

  16. Formation of the First Star Clusters

    E-print Network

    Klessen,Ralf

    Formation of the First Star Clusters Ralf Klessen Zentrum für Astronomie der Universität Heidelberg-Hsu Wang ... many collaborators abroad! #12;First star formation agenda #12;Star cluster formation First of molecular clouds Star cluster formation First star formation Magnetic fields in the primordial universe

  17. Sandstone Formations in Capitol Reef

    USGS Multimedia Gallery

    Capitol Reef is primarily made up of sandstone formations within the Waterpocket Fold, monocline that extends nearly 100 miles. A monocline is a step-like fold in rock strata that can resemble an enormous wrinkle in the earth....

  18. Databases and mapping File formats

    E-print Network

    South Bohemia, University of

    Databases and mapping BWA Samtools #12;File formats FASTQ, SFF, bax.h5 ACE, FASTG FASTA BAM/SAM GFF polymorphism and assembly uncertainty. The G stands for `graph'. http://fastg.sourceforge.net #FASTG

  19. Marmoryen Formation (marble) STORETVEIT GROUP

    E-print Network

    Fossen, Haakon

    ) STORETVEIT GROUP Minor Bergen Arc Paradis Formation (green polymict congl.) Deformed saussurite gabbro, gabbro-pegmatite, basic/acidic dykes NORDÅSVATN COMPLEX Fine-grained amphibolite, mylonitic in most

  20. The Formation of Galaxy Disks

    E-print Network

    Joseph Silk

    2000-10-31

    Galaxy disk formation must incorporate the multiphase nature of the interstellar medium. The resulting two-phase structure is generated and maintained by gravitational instability and supernova energy input, which yield a source of turbulent viscosity that is able to effectively compete in the protodisk phase with early angular momentum loss of the baryonic component via dynamical friction in the dark halo. Provided that star formation occurs on the viscous drag time-scale, this mechanism provides a means of accounting for disk sizes and radial profiles. The star formation feedback is self-regulated by turbulent gas pressure-limited percolation of the supernova remnant-heated hot phase, but can run away in gas-rich protodisks to generate compact starbursts. A simple analytic model is derived for a Schmidt-like global star formation law in terms of the cold gas volume density.

  1. Micromagnetosphere Formation on the Moon

    NASA Astrophysics Data System (ADS)

    Zimmerman, M. I.; Farrell, W. M.; Poppe, A. R.

    2015-10-01

    Kinetic simulations of the solar wind's interaction with lunar crustal magnetic fields reveal formation of micromagnetospheres where ions are deflected by strong electric fields. Future missions should measure magnetic field structure at the ground.

  2. Cosmic strings and galaxy formation

    NASA Technical Reports Server (NTRS)

    Bertschinger, Edmund

    1989-01-01

    The cosmogonical model proposed by Zel'dovich and Vilenkin (1981), in which superconducting cosmic strings act as seeds for the origin of structure in the universe, is discussed, summarizing the results of recent theoretical investigations. Consideration is given to the formation of cosmic strings, the microscopic structure of strings, gravitational effects, cosmic string evolution, and the formation of galaxies and large-scale structure. Simulation results are presented in graphs, and several outstanding issues are listed and briefly characterized.

  3. The Portable Document Format - PDF.

    PubMed

    Grech, V

    2002-04-01

    This article demonstrates how documents prepared in hypertext or word processor format can be saved in portable document format (PDF). These files are self-contained documents that that have the same appearance on screen and in print, regardless of what kind of computer or printer are used, and regardless of what software package was originally used to for their creation. PDF files are compressed documents, invariably smaller than the original files, hence allowing rapid dissemination and download. PMID:22368611

  4. Immigration, Integration and Ghetto Formation

    NASA Astrophysics Data System (ADS)

    Meyer-Ortmanns, Hildegard

    We study ghetto formation in a population with natives and immigrants in the framework of the two-dimensional Ising-model with Kawasaki-exchange dynamics. It is the phase structure of the Ising model, the integration speed and the immigration rate which determine whether ghetto formation between natives and immigrants can be avoided or not. Our simulations are performed in- and out-of-equilibrium.

  5. Progress in Giant Planet Formation

    NASA Astrophysics Data System (ADS)

    Boss, A. P.

    Two very different mechanisms have been proposed for the formation of the gas and ice giant planets. The conventional explanation for the formation of gas giant planets, core accretion, presumes that a gaseous envelope collapses upon a roughly 10 Earth-mass, solid core that was formed by the collisional accumulation of planetary embryos orbiting in a gaseous disk. The more radical explanation, disk instability, hypothesizes that the gaseous portion of protoplanetary disks undergoes a gravitational instability, leading to the formation of self-gravitating clumps, within which dust grains coagulate and settle to form cores. Core accretion appears to require several million years or more to form a gas giant planet, implying that only long-lived disks would form gas giants. Disk instability, on the other hand, is so rapid (thousands of years), that gas giants could form in even the shortest-lived disks. Core accretion has severe difficulty in explaining the formation of the ice giant planets, unless two extra protoplanets are formed in the gas giant planet region and thereafter migrate outward. Recently, an alternative mechanism for ice giant planet formation has been proposed, based on observations of protoplanetary disks in the Orion nebula cluster: disk instability leading to the formation of four gas giant protoplanets with cores, followed by photoevaporation of the disk and gaseous envelopes of the protoplanets outside about 10 AU by a nearby OB star, producing ice giants. In this scenario, Jupiter survives unscathed, while Saturn is a transitional planet. These two basic mechanisms have very different predictions for gas and ice giant extrasolar planets, both in terms of their frequency and epoch of formation, suggesting a number of astronomical tests which could determine the dominant mechanism for giant planet formation.

  6. Gypsum Layer in Spearfish Formation, SD

    USGS Multimedia Gallery

    Spearfish Formation near Spearfish, SD. The Spearfish Formation is a red, silty shale with interbedded red sandstone and siltstone. The formation contains massive gypsum deposits, which is the white layer in the photograph....

  7. SW New Mexico Oil Well Formation Tops

    SciTech Connect

    Shari Kelley

    2015-10-21

    Rock formation top picks from oil wells from southwestern New Mexico from scout cards and other sources. There are differing formation tops interpretations for some wells, so for those wells duplicate formation top data are presented in this file.

  8. 76 FR 22935 - Calvert Cliffs Nuclear Power Plant, LLC Independent Spent Fuel Storage Installation; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-25

    ...Cliffs Nuclear Power Plant, LLC Independent Spent...of Opportunity for a Hearing for Renewal of Special...opportunity to request a hearing...DATES: A request for hearing and/or petition for...Cliffs Nuclear Power Plant (CCNPP), LLC,...

  9. 75 FR 60147 - Calvert Cliffs Nuclear Power Plant, LLC; Independent Spent Fuel Storage Installation; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ...limit with a maximum cooling time of seven years to be loaded. Raises the NUHOMS[supreg]-32P DSC neutron source to 4.175 x 10\\8\\ neutrons/sec/ assembly to support storage of the higher burnup fuel. 3. LCO 3.4.1.1,...

  10. 78 FR 23563 - LWD, Inc. Superfund Site; Calvert City, Marshall County, Kentucky; Notice of Settlement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-19

    ...: Environmental Protection Agency (EPA). ACTION: Notice of Settlement. SUMMARY: Under 122(h) of the Comprehensive.../enforcement.html Email. Painter.Paula@epa.gov U.S. Environmental Protection Agency, Attn: Paula V. Painter... From the Federal Register Online via the Government Printing Office ENVIRONMENTAL...

  11. Calibration For Augmented Reality Experimental Testbeds Valerie A. Summers*& Kellogg S. Booth Tom Calvert

    E-print Network

    Calibration For Augmented Reality Experimental Testbeds Valerie A. Summers*& Kellogg S. Booth Tom.3.7[ComputerGraphics]: Three-Dimensional GraphicsandRealism-virtual reality Keywords: augmentedreality "augment" theuser's view of thereal 3D world with computer-generatedvirtual objects. Thesevirtual

  12. 76 FR 22935 - Calvert Cliffs Nuclear Power Plant, LLC Independent Spent Fuel Storage Installation; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-25

    ... renewed for 40 years. On February 16, 2011, (76 FR 8872) the revised 10 CFR 72.230(b) rule was published... meets the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act) and the... in a Safety Evaluation Report. The NRC will complete an environmental evaluation, in accordance...

  13. Significant melting of ice-wedges and formation of thermocirques on hill-slopes of thermokarst lakes in Central Yakutia (Siberia)

    NASA Astrophysics Data System (ADS)

    Séjourné, Antoine; Costard, François; Gargani, Julien; Fedorov, Alexander; Skorve, Johnny

    2013-04-01

    On Earth, permafrost containing a high ice volume (referred as ice-rich) are sensible to climate change, they have been regionally degraded (thermokarst) during the early Holocene climatic optimum forming numerous thermokarst lakes in Central Yakutia (eastern Siberia). Recent temperature increases in the Arctic and Subarctic have been significantly greater than global averages. The frequency and magnitude of terrain disturbances associated with thawing permafrost are increasing in these regions and are thought to intensify in the future. Therefore, understand how is the current development of thermokarst is a critical question. Here, we describe the significant melting of ice-wedges on slopes of thermokarst lakes that leads to formation of amphitheatrical hollows referred as thermocirques. The evolution of thermocirques in Central Yakutia has been little studied and analyzing their formation could help to understand the recent thermokarst in relation to climate change in Central Yakutia. We studied the thermocirques at two scales: (i) field surveys of different thermocirques in July 2009-2010 and October 2012 to examine the processes and origin of melting of ice-wedges and; (ii) photo-interpretation of time series of satellite images (KH-9 Hexagon images of 6-9 m/pixel and GeoEye images of 50 cm/pixel) to study the temporal evolution of thermocirques. The melting of ground-ice on the scarp of thermocirque triggers falls and small mud-flows that induce the retreat of the scarp parallel to itself. Based on field studies and on GeoEye image comparison, we show that their rate of retrogressive growth is 1-2 m/year. On the hill-slopes of lakes, the thermokarst could be initiated by different processes that lead to the uncover and then melting of ice-wedges: thermal erosion by the waves of the ice-rich bluff; active-layer detachment (a form of slope failure linked to detachment of the seasonally thawed upper ground); flowing of water on the slope (precipitation) or; increase of near-surface temperature (insolation, summer temperature). We suggest that the preferential occurrence of thermocirques on south-facing slopes of lakes could emphasize the role of insolation as a factor controlling the preferential melting of ice-wedges. The air temperatures are shown to have increased in Central Yakutia over years and deciphering if ongoing climate warming could lead to an increased development of thermocirques along lake slopes in Central Yakutia is a question that we will address in future study.

  14. The Dynamics of Latifundia Formation

    PubMed Central

    Chaves, Luis Fernando

    2013-01-01

    Land tenure inequity is a major social problem in developing nations worldwide. In societies, where land is a commodity, inequities in land tenure are associated with gaps in income distribution, poverty and biodiversity loss. A common pattern of land tenure inequities through the history of civilization has been the formation of latifundia [Zhu?ngyuán in chinese], i.e., a pattern where land ownership is concentrated by a small fraction of the whole population. Here, we use simple Markov chain models to study the dynamics of latifundia formation in a heterogeneous landscape where land can transition between forest, agriculture and recovering land. We systematically study the likelihood of latifundia formation under the assumption of pre-capitalist trade, where trade is based on the average utility of land parcels belonging to each individual landowner during a discrete time step. By restricting land trade to that under recovery, we found the likelihood of latifundia formation to increase with the size of the system, i.e., the amount of land and individuals in the society. We found that an increase of the transition rate for land use changes, i.e., how quickly land use changes, promotes more equitable patterns of land ownership. Disease introduction in the system, which reduced land profitability for infected individual landowners, promoted the formation of latifundia, with an increased likelihood for latifundia formation when there were heterogeneities in the susceptibility to infection. Finally, our model suggests that land ownership reforms need to guarantee an equitative distribution of land among individuals in a society to avoid the formation of latifundia. PMID:24376597

  15. The Physics of Planetesimal Formation

    NASA Astrophysics Data System (ADS)

    Simon, Jacob; Armitage, Philip; Youdin, Andrew; Li, Rixin

    2015-12-01

    Planetesimals are the precursors to planets, and understanding their formation is an essential step towards developing a complete theory of planet formation. For small solid particles (e.g., dust grains) to coagulate into planetesimals, however, requires that these particles grow beyond centimeter sizes; with traditional coagulation physics, this is very difficult. The streaming instability, which is a clumping process akin to the pile-up of cars in a traffic jam, generates sufficiently high solid densities that the mutual gravity between the clumped particles eventually causes their collapse towards planetesimal mass and size scales. Exploring this transition from dust grains to planetesimals is still in its infancy but is extremely important if we want to understand the basics of planet formation. Here, I present a series of high resolution, first principles numerical simulations of potoplanetary disk gas and dust to study the clumping of particles via the streaming instability and the subsequent collapse towards planetesimals. These simulations have been employed to characterize the planetesimal population as a function of radius in protoplanetary disks. The results of these simulations will be crucial for planet formation models to correctly explain the formation and configuration of solar systems.

  16. Review of nutrition labeling formats.

    PubMed

    Geiger, C J; Wyse, B W; Parent, C R; Hansen, R G

    1991-07-01

    This article examines nutrition labeling history as well as the findings of nine research studies of nutrition labeling formats. Nutrition labeling regulations were announced in 1973 and have been periodically amended since then. In response to requests from consumers and health care professionals for revision of the labeling system, the Food and Drug Administration initiated a three-phase plan for reform of nutrition labeling in 1990. President Bush signed the Nutrition Labeling and Education Act in November 1990. Literature analysis revealed that only nine studies with an experimental design have focused on nutrition labeling since 1971. Four were conducted before 1975, which was the year that nutrition labeling was officially implemented, two were conducted in 1980, and three were conducted after 1986. Only two of the nine studies supported the traditional label format mandated by the Code of Federal Regulations, and one study partially supported it. Four of the nine studies that evaluated graphic presentations of nutrition information found that consumer comprehension of nutrition information was improved with a graphic format for nutrition labeling: three studies supported the use of bar graphs and one study supported the use of a pie chart. Full disclosure (ie, complete nutrient and ingredient labeling) was preferred by consumers in two of the three studies that examined this variable. The third study supported three types of information disclosure dependent upon socioeconomic class. In those studies that tested graphics, a bar graph format was significantly preferred and showed better consumer comprehension than the traditional format. PMID:2071796

  17. Biofilm Formation by Candida dubliniensis

    PubMed Central

    Ramage, Gordon; Vande Walle, Kacy; Wickes, Brian L.; López-Ribot, José L.

    2001-01-01

    Candida dubliniensis is an opportunistic yeast closely related to Candida albicans that has been recently implicated in oropharyngeal candidiasis in human immunodeficiency virus-infected patients. Most manifestations of candidiasis are associated with biofilm formation, with cells in biofilms displaying properties dramatically different from free-living cells grown under normal laboratory conditions. Here, we report on the development of in vitro models of C. dubliniensis biofilms on the surfaces of biomaterials (polystyrene and acrylic) and on the characteristics associated with biofilm formation by this newly described species. Time course analysis using a formazan salt reduction assay to monitor metabolic activities of cells within the biofilm, together with microscopy studies, revealed that biofilm formation by C. dubliniensis occurred after initial focal adherence, followed by growth, proliferation, and maturation over 24 to 48 h. Serum and saliva preconditioning films enhanced the initial attachment of C. dubliniensis and subsequent biofilm formation. Scanning electron microscopy and confocal scanning laser microscopy were used to further characterize C. dubliniensis biofilms. Mature C. dubliniensis biofilms consisted of a dense network of yeasts cells and hyphal elements embedded within exopolymeric material. C. dubliniensis biofilms displayed spatial heterogeneity and an architecture showing microcolonies with ramifying water channels. Antifungal susceptibility testing demonstrated the increased resistance of sessile C. dubliniensis cells, including the type strain and eight different clinical isolates, against fluconazole and amphotericin B compared to their planktonic counterparts. C. dubliniensis biofilm formation may allow this species to maintain its ecological niche as a commensal and during infection with important clinical repercussions. PMID:11526156

  18. Formate dehydrogenase of Clostridium pasteurianum.

    PubMed Central

    Liu, C L; Mortenson, L E

    1984-01-01

    Formate dehydrogenase was purified to electrophoretic homogeneity from N2-fixing cells of Clostridium pasteurianum W5. The purified enzyme has a minimal Mr of 117,000 with two nonidentical subunits with molecular weights of 76,000 and 34,000, respectively. It contains 2 mol of molybdenum, 24 mol of nonheme iron, and 28 mol of acid-labile sulfide per mol of enzyme; no other metal ions were detected. Analysis of its iron-sulfur centers by ligand exchange techniques showed that 20 iron atoms of formate dehydrogenase can be extruded as Fe4S4 centers. Fluorescence analysis of its isolated molybdenum centers suggests it is a molybdopterin. The clostridial formate dehydrogenase has a pH optimum between 8.3 and 8.5 and a temperature optimum of 52 degrees C. The Km for formate is 1.72 mM with a Vmax of 551 mumol of methyl viologen reduced per min per mg of protein. Sodium azide competes competitively with formate (K1 = 3.57 microM), whereas the inactivation by cyanide follows pseudo-first-order kinetics with K = 5 X 10(2) M-1 s-1. PMID:6547435

  19. 78 FR 24007 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Eriogonum codium

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ...most critical potential threats (i.e., slope failure and landslides), and questioned the rationale used to support a conclusion...v) The presence of stable bluff formations with minimal landslide occurrence. (3) Critical habitat does not include...

  20. Sterile neutrinos and structure formation

    E-print Network

    Stasielak, Jaroslaw; Kusenko, Alexander

    2007-01-01

    Warm dark matter is consistent with the observations of the large-scale structure, and it can also explain the cored density profiles on smaller scales. However, it has been argued that warm dark matter could delay the star formation. This does not happen if warm dark matter is made up of keV sterile neutrinos, which can decay into X-ray photons and active neutrinos. The X-ray photons have a catalytic effect on the formation of molecular hydrogen, the essential cooling ingredient in the primordial gas. In all the cases we have examined, the overall effect of sterile dark matter is to facilitate the cooling of the gas and to reduce the minimal mass of the halo prone to collapse. We find that the X-rays from the decay of keV sterile neutrinos facilitate the collapse of the gas clouds and the subsequent star formation at high redshift.

  1. Sterile neutrinos and structure formation

    E-print Network

    Jaroslaw Stasielak; Peter L. Biermann; Alexander Kusenko

    2007-10-29

    Warm dark matter is consistent with the observations of the large-scale structure, and it can also explain the cored density profiles on smaller scales. However, it has been argued that warm dark matter could delay the star formation. This does not happen if warm dark matter is made up of keV sterile neutrinos, which can decay into X-ray photons and active neutrinos. The X-ray photons have a catalytic effect on the formation of molecular hydrogen, the essential cooling ingredient in the primordial gas. In all the cases we have examined, the overall effect of sterile dark matter is to facilitate the cooling of the gas and to reduce the minimal mass of the halo prone to collapse. We find that the X-rays from the decay of keV sterile neutrinos facilitate the collapse of the gas clouds and the subsequent star formation at high redshift.

  2. Structure formation in active networks

    E-print Network

    Köhler, Simone; Bausch, Andreas R

    2011-01-01

    Structure formation and constant reorganization of the actin cytoskeleton are key requirements for the function of living cells. Here we show that a minimal reconstituted system consisting of actin filaments, crosslinking molecules and molecular-motor filaments exhibits a generic mechanism of structure formation, characterized by a broad distribution of cluster sizes. We demonstrate that the growth of the structures depends on the intricate balance between crosslinker-induced stabilization and simultaneous destabilization by molecular motors, a mechanism analogous to nucleation and growth in passive systems. We also show that the intricate interplay between force generation, coarsening and connectivity is responsible for the highly dynamic process of structure formation in this heterogeneous active gel, and that these competing mechanisms result in anomalous transport, reminiscent of intracellular dynamics.

  3. Sterile Neutrinos and Structure Formation

    NASA Astrophysics Data System (ADS)

    Stasielak, J.; Biermann, P. L.; Kusenko, A.

    2007-12-01

    Warm dark matter is consistent with the observations of the large-scale structure, and it can also explain the cored density profiles on smaller scales. However, it has been argued that warm dark matter could delay the star formation. This does not happen if warm dark matter is made up of keV sterile neutrinos, which can decay into X-ray photons and active neutrinos. The X-ray photons have a catalytic effect on the formation of molecular hydrogen, the essential cooling ingredient in the primordial gas. In all the cases we have examined, the overall effect of sterile dark matter is to facilitate the cooling of the gas and to reduce the minimal mass of the halo prone to collapse. We find that the X-rays from the decay of keV sterile neutrinos facilitate the collapse of the gas clouds and the subsequent star formation at high redshift.

  4. Structure formation in active networks

    E-print Network

    Simone Köhler; Volker Schaller; Andreas R. Bausch

    2011-03-18

    Structure formation and constant reorganization of the actin cytoskeleton are key requirements for the function of living cells. Here we show that a minimal reconstituted system consisting of actin filaments, crosslinking molecules and molecular-motor filaments exhibits a generic mechanism of structure formation, characterized by a broad distribution of cluster sizes. We demonstrate that the growth of the structures depends on the intricate balance between crosslinker-induced stabilization and simultaneous destabilization by molecular motors, a mechanism analogous to nucleation and growth in passive systems. We also show that the intricate interplay between force generation, coarsening and connectivity is responsible for the highly dynamic process of structure formation in this heterogeneous active gel, and that these competing mechanisms result in anomalous transport, reminiscent of intracellular dynamics.

  5. A New Spoke Formation Model

    NASA Astrophysics Data System (ADS)

    Jones, G. H.; Krupp, N.; Krueger, H.; Roussos, E.; Ip, W.; Mitchell, D. G.; Krimigis, S. M.; Woch, J.; Lagg, A.; Fraenz, M.; Dougherty, M. K.; Arridge, C. S.; McAndrews, H. J.

    2006-12-01

    A new model is proposed for the formation of spokes in Saturn's rings. We contend that they are formed by the electrostatic charging of sub-micron ring particles by magnetic field-aligned electron beams originating in Saturn's atmosphere. The existence of these beams has recently been confirmed by the MIMI instrument aboard Cassini. Although observed by MIMI outside the main ring system, the beams are also expected to occur closer to the planet. On striking the rings, the electrons charge the dust, causing the levitation of the fine grains above the main ring plane. A simulation of the proposed formation process provides strong supporting evidence for the validity of the process, explaining the spokes' formation locations, morphologies, and subsequent development as observed in Voyager images. The process can be tested using Cassini observations; we outline how the model's validity can be gauged.

  6. Conductive Anodic Filament (CAF) Formation

    NASA Astrophysics Data System (ADS)

    Caputo, Antonio

    Conductive anodic filament (CAF) is a failure mode in printed wiring boards (PWBs) which occurs under high humidity and high voltage gradient conditions. The filament, a copper salt, grows from anode to cathode along the epoxy-glass interface. Ready and Turbini (2000) identified this copper salt as the Cu 2(OH)3Cl, atacamite compound. This work has investigated the influence of polyethylene glycol (PEG) and polyethylene propylene glycol (PEPG) fluxing agents on the chemical nature of CAF. For coupons processed with PEPG flux, with and without chloride, a copper-chloride containing compound was formed in the polymer matrix. This compound was characterized using x-ray photoelectron spectroscopy (XPS) as CuCl and an electrochemical mechanism for the formation of the chloride-containing CAF has been proposed. For PEG flux, with and without chloride, it has been shown that CAF only formed, but no copper containing compound formed in the matrix. It appears for PEG fluxed coupons, a PEG-Cu-Cl complex forms, binds the available Cu and acts as a barrier to the formation of CuCl in the polymer matrix. Meeker and Lu Valle (1995) have previously proposed that CAF failure is best represented by two competing reactions -- the formation of a copper chloride corrosion compound (now identified as Cu2(OH)3Cl) and the formation of innocuous trapped chlorine compounds. Since no evidence of any trapped chloride compounds has been found, we propose that the formation of CAF is best represented by a single non-reversible reaction. For coupons processed with a high bromide-containing flux, bromide containing CAF was created and characterized using transmission electron microscopy (TEM) to be Cu2(OH)3Br. In addition, a copper-containing compound was formed in the polymer matrix and characterized using XPS as CuBr. An electrochemical mechanism for the formation of bromide-containing CAF has been proposed based on the XPS data.

  7. Formation of the first stars.

    PubMed

    Bromm, Volker

    2013-11-01

    Understanding the formation of the first stars is one of the frontier topics in modern astrophysics and cosmology. Their emergence signalled the end of the cosmic dark ages, a few hundred million years after the Big Bang, leading to a fundamental transformation of the early Universe through the production of ionizing photons and the initial enrichment with heavy chemical elements. We here review the state of our knowledge, separating the well understood elements of our emerging picture from those where more work is required. Primordial star formation is unique in that its initial conditions can be directly inferred from the ? cold dark matter (?CDM) model of cosmological structure formation. Combined with gas cooling that is mediated via molecular hydrogen, one can robustly identify the regions of primordial star formation, the so-called minihalos, having total masses of ~10(6) M? and collapsing at redshifts z ? 20-30. Within this framework, a number of studies have defined a preliminary standard model, with the main result that the first stars were predominantly massive. This model has recently been modified to include a ubiquitous mode of fragmentation in the protostellar disks, such that the typical outcome of primordial star formation may be the formation of a binary or small multiple stellar system. We will also discuss extensions to this standard picture due to the presence of dynamically significant magnetic fields, of heating from self-annihalating WIMP dark matter, or cosmic rays. We conclude by discussing possible strategies to empirically test our theoretical models. Foremost among them are predictions for the upcoming James Webb space telescope (JWST), to be launched ~2018, and for 'stellar archaeology', which probes the abundance pattern in the oldest, most-metal poor stars in our cosmic neighborhood, thereby constraining the nucleosynthesis inside the first supernovae. PMID:24168986

  8. Cosmic Star-Formation History

    NASA Astrophysics Data System (ADS)

    Madau, Piero; Dickinson, Mark

    2014-08-01

    Over the past two decades, an avalanche of new data from multiwavelength imaging and spectroscopic surveys has revolutionized our view of galaxy formation and evolution. Here we review the range of complementary techniques and theoretical tools that allow astronomers to map the cosmic history of star formation, heavy element production, and reionization of the Universe from the cosmic “dark ages” to the present epoch. A consistent picture is emerging, whereby the star-formation rate density peaked approximately 3.5 Gyr after the Big Bang, at z?1.9, and declined exponentially at later times, with an e-folding timescale of 3.9 Gyr. Half of the stellar mass observed today was formed before a redshift z = 1.3. About 25% formed before the peak of the cosmic star-formation rate density, and another 25% formed after z = 0.7. Less than ˜1% of today's stars formed during the epoch of reionization. Under the assumption of a universal initial mass function, the global stellar mass density inferred at any epoch matches reasonably well the time integral of all the preceding star-formation activity. The comoving rates of star formation and central black hole accretion follow a similar rise and fall, offering evidence for coevolution of black holes and their host galaxies. The rise of the mean metallicity of the Universe to about 0.001 solar by z = 6, one Gyr after the Big Bang, appears to have been accompanied by the production of fewer than ten hydrogen Lyman-continuum photons per baryon, a rather tight budget for cosmological reionization.

  9. Pattern formation in the geosciences

    PubMed Central

    Goehring, Lucas

    2013-01-01

    Pattern formation is a natural property of nonlinear and non-equilibrium dynamical systems. Geophysical examples of such systems span practically all observable length scales, from rhythmic banding of chemical species within a single mineral crystal, to the morphology of cusps and spits along hundreds of kilometres of coastlines. This article briefly introduces the general principles of pattern formation and argues how they can be applied to open problems in the Earth sciences. Particular examples are then discussed, which summarize the contents of the rest of this Theme Issue. PMID:24191107

  10. Star formation and extinct radioactivities

    NASA Technical Reports Server (NTRS)

    Cameron, A. G. W.

    1984-01-01

    An assessment is made of the evidence for the existence of now-extinct radioactivities in primitive solar system material, giving attention to implications for the early stages of sun and solar system formation. The characteristics of possible disturbances in dense molecular clouds which can initiate the formation of cloud cores is discussed, with emphasis on these disturbances able to generate fresh radioactivities. A one-solar mass red giant star on the asymptotic giant branch appears to have been the best candidate to account for the short-lived extinct radioactivities in the early solar system.

  11. Formation de laborantin biologie ou chimieen

    E-print Network

    Halazonetis, Thanos

    Formation de laborantin biologie ou chimieen Unité de Formation des apprentis ochure_A6_Laborantin.indd 1 03/12/13 17:1 #12;Formation de laborantin en biologie Introduction L'Unité de Formation des Apprentis (UFA) forme les apprentis laborantin* CFC orientation biologie et orientation chimie au sein de l

  12. What Is Formation? A Conceptual Discussion

    ERIC Educational Resources Information Center

    Sutphen, Molly; de Lange, Thomas

    2015-01-01

    This paper addresses the principles and connotations of the term "formation." In our discussion of formation, we draw on different disciplines in order to widen and deepen our understanding of the concept of formation. We also mirror the formation concept against comparable terms and draw on studies in which it has been applied in…

  13. Paleoenvironmental and paleoclimatic significance of freshwater bivalves in the Upper Jurassic Morrison Formation, Western Interior, USA

    NASA Astrophysics Data System (ADS)

    Good, Steven C.

    2004-05-01

    Freshwater unionid bivalves are spatially and temporally distributed throughout the Morrison depositional basin, and locally dominate the biomass of many aquatic depositional environments. Two bivalve assemblages are identified. Within-channel assemblages are death assemblages that have been transported and may represent mixed assemblages from multiple communities. These assemblages are predominately disarticulated, in current stable orientations, and composed of higher stream velocity ecophenotypes (medium size, lanceolate form, and very thick shells). The floodplain-pond assemblages are disturbed neighborhood assemblages in the mudstones inhabited during life. The bivalves are predominately articulated, variable in size, and composed of low stream velocity ecophenotypes (large maximum sizes, ovate shell shapes, and thinner shells). The glochidial parasitic larval stage of unionid bivalves provides an effective means of dispersing species throughout drainage basins. These larvae attach to fish and are carried through the fluvial drainage where the larvae detach and establish new bivalve communities. Preliminary paleobiogeographic analyses are drawn at the genus level because of the need to reevaluate bivalve species of the Morrison. Unio spp. and Vetulonaia spp. are widespread throughout the Morrison depositional basin, but Hadrodon spp. are restricted to the eastern portion of the Colorado Plateau during Salt Wash Member deposition, suggesting that Salt Wash drainage was isolated from other contemporaneous regions of the basin. Bivalves from five localities in the Morrison Formation were thin-sectioned for growth band analysis. Growth bands of modern unionid bivalves are produced when the valves are forced to close. Closure can produce annual growth bands in response to seasonal variation, such as temperature-induced hibernation, or precipitation-induced aestivation or turbidity. Pseudoannual growth bands form from non-cyclical events such as predation attacks or isolated storm turbidity. Vetulonaia sp. from the Tidwell Member, Green River, Utah, and from Tidwell-equivalent beds at Como Bluff, Wyoming, exhibits continuous growth with no annual banding, suggesting that seasonality of climate and discharge did not vary appreciable during the year. Hadrodon sp. from the Salt Wash Member in Colorado National Monument, Colorado, exhibits annual banding with subequal light and dark bands indicating seasonal cyclicity. Vetulonaia sp. from the Cleveland-Lloyd locality, Utah, exhibits complex banding that indicates a combination of annual and pseudoannual bands. This suggests seasonal cyclicity and intermittent periods of environmental stress (predation, storm-produced turbidity and/or volcanic ash falls). Specimens of Vetulonaia sp. from Dinosaur National Monument, Utah, are replaced by chert with faint ghosts of bands that are too poorly preserved for environmental interpretations. Preliminary growth band studies suggest a change from a uniform optimum habitat in the Tidwell Member to strongly developed annual growth banding in the Salt Wash Member, suggesting cyclic annual precipitation, and finally to irregular banding produced by a complex interaction of weakly developed annual growth bands and pseudoannual bands in the Brushy Basin Member.

  14. Method of fracturing a geological formation

    DOEpatents

    Johnson, James O. (2679-B Walnut, Los Alamos, NM 87544)

    1990-01-01

    An improved method of fracturing a geological formation surrounding a well bore is disclosed. A relatively small explosive charge is emplaced in a well bore and the bore is subsequently hydraulically pressurized to a pressure less than the formation breakdown pressure and preferably greater than the fracture propagation pressure of the formation. The charge is denoted while the bore is so pressurized, resulting in the formation of multiple fractures in the surrounding formation with little or no accompanying formation damage. Subsequent hydraulic pressurization can be used to propagate and extend the fractures in a conventional manner. The method is useful for stimulating production of oil, gas and possibly water from suitable geologic formations.

  15. ASDF: A new data format for astronomy

    NASA Astrophysics Data System (ADS)

    Greenfield, P.; Droettboom, M.; Bray, E.

    2015-09-01

    We present the case for developing a successor format for the immensely successful FITS format. We first review existing alternative formats and discuss why we do not believe they provide an adequate solution. The proposed format is called the Advanced Scientific Data Format (ASDF) and is based on an existing text format, YAML, that we believe removes most of the current problems with the FITS format. An overview of the capabilities of the new format is given along with specific examples. This format has the advantage that it does not limit the size of attribute names (akin to FITS keyword names) nor place restrictions on the size or type of values attributes have. Hierarchical relationships are explicit in the syntax and require no special conventions. Finally, it is capable of storing binary data within the file in its binary form. At its basic level, the format proposed has much greater applicability than for just astronomical data.

  16. Formative Assessment in Primary Science

    ERIC Educational Resources Information Center

    Loughland, Tony; Kilpatrick, Laetitia

    2015-01-01

    This action learning study in a year three classroom explored the implementation of five formative assessment principles to assist students' understandings of the scientific topic of liquids and solids. These principles were employed to give students a greater opportunity to express their understanding of the concepts. The study found that…

  17. Audiences for Contemporary Radio Formats.

    ERIC Educational Resources Information Center

    Lull, James T.; And Others

    A radio audience survey of 110 sample geographic clusters in the Santa Barbara, California, area served a twofold purpose: the construction of a demographic profile of audience types according to radio format choices, and the identification and analysis of various audience subgroups. A skip interval technique of these geographic clusters resulted…

  18. A standard audit trail format

    SciTech Connect

    Bishop, M.

    1995-02-01

    The central role of audit trails, or (more properly) logs, in security monitoring needs little description, for it is too well known for any to doubt it. Auditing, or the analysis of logs, is a central part of security not only in computer system security but also in analyzing financial and other non-technical systems. As part of this process, it is often necessary to reconcile logs from different sources. This speaks of a need for a standard logging format. A standard log format robust enough to meet the needs of heterogeneity, transportability across various network protocols, and flexibility sufficient to meet a variety of needs in very different environments must satisfy two basic properties: extensibility and portability. This report presents the author`s proposed format for a standard log record. In section 3, he shows how and where the translation should be done, and in section 4 he demonstrates how log records from several disparate systems would be put into this format. Section 5 concludes with some observations and suggestions for future work.

  19. Formation of myocardial zonal lesions.

    PubMed Central

    Ratliff, N. B.; Kopelman, R. I.; Goldner, R. D.; Cruz, P. T.; Hackel, D. B.

    1975-01-01

    Right ventricular papillary muscles from control cats and from cats subjected to hemorrhagic shock were studied by electron microscopy. Half of the muscles were fixed at the apex of their active length-tension curves following stimulation in a papillary muscle bath. The other half were also fixed under tension. The ultrastructure of each muscle was examined in detail. A series of stages in the formation of myocardial zonal lesions, ranging from minimal changes in the intercalated discs to severe lesions, were identified and interpreted as representing the sequential stages in the formation of zonal lesions. One of the earliest (least severe) changes in the formation of zonal lesions, the separations of actin filaments from the intercalated disc, may be critical to the subsequent development of cardiac failure in hypovolemic shock. Mitochondrial displacement was a late event in the formation of the lesions, occurring only after major alterations had taken place in the sarcomeres and intercalated discs. It was noted that the ultrastructure of mitochondria remained essentially normal, and that there was no cell swelling associated with zonal lesions. This serves as confirmatory evidence that myocardial zonal lesions are a unique form of myocyte injury, are potentially reversible, and are not caused by ischemia. Images Fig 1 Fig 2 Fig 3 Fig 4 Fig 5 Fig 6 Fig 7 Fig 8 Fig 9 Fig 10 PMID:1146964

  20. SAS FORMATS: USES AND ABUSES

    EPA Science Inventory

    SAS formats are a very powerful tool. They allow you to display the data in a more readable manner without modifying the data. They can also be used to group data into categories for use in various procedures like PROC FREQ, PROC TTEST, and PROC MEANS (as a class variable). ...

  1. Oxide formation: reaction details studied,

    E-print Network

    Johnson, Edward A.

    Oxide formation: reaction details studied, reported in brief Sir -- Nineteen years ago, I published-nitrosohydroxylamines undergo an alternative decomposition under very similar reaction conditions to liberate nitrous oxide, N2O (refs 4,5). Moreover, this alternative reaction involves highly electrophilic intermediates analogous

  2. Cave Formations in Wind Cave

    USGS Multimedia Gallery

    Wind Cave is the first cave national park and currently, the 6th most extensive cave network in the world. It's most famous for its large concentration of a fairly rare cave formation known as boxwork. Boxwork is formed when dissolved calcium carbonate crystallized in cracks in surrounding rock. The...

  3. Understanding Galaxy Formation and Evolution

    NASA Astrophysics Data System (ADS)

    Avila-Reese, Vladimir

    The old dream of integrating into one the study of micro and macrocosmos is now a reality. Cosmology, astrophysics and particle physics converge within a scenario (but still not a theory) of cosmic structure formation and evolution called ? Cold Dark Matter (?CDM).

  4. Understanding Galaxy Formation and Evolution

    E-print Network

    V. Avila-Reese

    2006-05-09

    The old dream of integrating into one the study of micro and macrocosmos is now a reality. Cosmology, astrophysics, and particle physics intersect in a scenario (but still not a theory) of cosmic structure formation and evolution called Lambda Cold Dark Matter (LCDM) model. This scenario emerged mainly to explain the origin of galaxies. In these lecture notes, I first present a review of the main galaxy properties, highlighting the questions that any theory of galaxy formation should explain. Then, the cosmological framework and the main aspects of primordial perturbation generation and evolution are pedagogically detached. Next, I focus on the ``dark side'' of galaxy formation, presenting a review on LCDM halo assembling and properties, and on the main candidates for non-baryonic dark matter. It is shown how the nature of elemental particles can influence on the features of galaxies and their systems. Finally, the complex processes of baryon dissipation inside the non-linearly evolving CDM halos, formation of disks and spheroids, and transformation of gas into stars are briefly described, remarking on the possibility of a few driving factors and parameters able to explain the main body of galaxy properties. A summary and a discussion of some of the issues and open problems of the LCDM paradigm are given in the final part of these notes.

  5. Star Formation in the Multiverse

    E-print Network

    Raphael Bousso; Stefan Leichenauer

    2008-10-17

    We develop a simple semi-analytic model of the star formation rate (SFR) as a function of time. We estimate the SFR for a wide range of values of the cosmological constant, spatial curvature, and primordial density contrast. Our model can predict such parameters in the multiverse, if the underlying theory landscape and the cosmological measure are known.

  6. Tooth formation - delayed or absent

    MedlinePLUS

    ... at which the tooth comes in varies. Most infants get their first tooth between 6 and 9 months, but it may ... in"? What other symptoms are also present? An infant with delayed or absent tooth formation may have other symptoms and signs that ...

  7. Cloud Formation, Evolution and Destruction

    E-print Network

    Estalella, Robert

    Chapter 4 Cloud Formation, Evolution and Destruction We now begin to trace the journey towards a star. How long does this take? The answer is surprisingly short: a good many clouds already contain new stars and these stars tend to be young. The typical cloud cannot spend long, if any time at all

  8. Cloud formation in substellar atmospheres

    E-print Network

    Christiane Helling

    2008-09-26

    Clouds seem like an every-day experience. But -- do we know how clouds form on brown dwarfs and extra-solar planets? How do they look like? Can we see them? What are they composed of? Cloud formation is an old-fashioned but still outstanding problem for the Earth atmosphere, and it has turned into a challenge for the modelling of brown dwarf and exo-planetary atmospheres. Cloud formation imposes strong feedbacks on the atmospheric structure, not only due to the clouds own opacity, but also due to the depletion of the gas phase, possibly leaving behind a dynamic and still supersaturated atmosphere. I summarise the different approaches taken to model cloud formation in substellar atmospheres and workout their differences. Focusing on the phase-non-equilibrium approach to cloud formation, I demonstrate the inside we gain from detailed micro-physical modelling on for instance the material composition and grain size distribution inside the cloud layer on a Brown Dwarf atmosphere. A comparison study on four different cloud approaches in Brown Dwarf atmosphere simulations demonstrates possible uncertainties in interpretation of observational data.

  9. Amyloid Beta Mediates Memory Formation

    ERIC Educational Resources Information Center

    Garcia-Osta, Ana; Alberini, Cristina M.

    2009-01-01

    The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid [beta] (1-42) peptide (A[beta][1-42]), which is believed to play a major role in amyloid plaque formation in Alzheimer's disease (AD). Here we provide evidence that, in contrast with its pathological role when accumulated,…

  10. Formative Assessment in Dance Education

    ERIC Educational Resources Information Center

    Andrade, Heidi; Lui, Angela; Palma, Maria; Hefferen, Joanna

    2015-01-01

    Feedback is crucial to students' growth as dancers. When used within the framework of formative assessment, or assessment for learning, feedback results in actionable next steps that dancers can use to improve their performances. This article showcases the work of two dance specialists, one elementary and one middle school teacher, who have…

  11. Stereotype Formation: Biased by Association

    ERIC Educational Resources Information Center

    Le Pelley, Mike E.; Reimers, Stian J.; Calvini, Guglielmo; Spears, Russell; Beesley, Tom; Murphy, Robin A.

    2010-01-01

    We propose that biases in attitude and stereotype formation might arise as a result of learned differences in the extent to which social groups have previously been predictive of behavioral or physical properties. Experiments 1 and 2 demonstrate that differences in the experienced predictiveness of groups with respect to evaluatively neutral…

  12. The EPRDATA Format: A Dialogue

    SciTech Connect

    Hughes, III, Henry Grady

    2015-08-18

    Recently the Los Alamos Nuclear Data Team has communicated certain issues of concern in relation to the new electron/photon/relaxation ACE data format as released in the eprdata12 library. In this document those issues are parsed, analyzed, and answered.

  13. Treating tar sands formations with dolomite

    DOEpatents

    Vinegar, Harold J.; Karanikas, John Michael

    2010-06-08

    Methods for treating a tar sands formation are described herein. The tar sands formation may include dolomite and hydrocarbons. Methods may include providing heat at less than the decomposition temperature of dolomite from one or more heaters to at least a portion of the formation. At least some of the hydrocarbon fluids are mobilized in the formation. At least some of the hydrocarbon fluids may be produced from the formation.

  14. Scale formation during alkaline flooding

    SciTech Connect

    Krumrine, P.H.; Brock, G.F.; Mayer, E.H.

    1984-04-01

    Alkaline chemicals in enhanced recovery operations have been and are being used: 1) as preflush agents, 2) with polymers and surfactants, and 3) as a principal recovery agent. In these chemical flooding techniques the reactions of multivalent hardness ions with alkalis to form precipitates are of particular concern. These reactions can be prevented at the injection wells through adequate preflushing and/or the use of good quality softened water; filtration can be used to remove any precipitates. These practices minimize the precipitation and subsequent damage to the well equipment and to the formation around the injectors, and reduce the chance for injectivity impairment. In the formation a host of reactions which significantly alter the injected slug occur including: dissolution, mixing, neutralization, and ion exchange. These may lead to fluid diversion as precipitates form to block high flow channels. At the producing wells, however, precipitation and deposition phenomena are undesirable since scales can form to restrict production and foul well equipment. With the higher concentrations of alkali being used in the field, the development of well scaling has become noticeable and difficult to control using previously accepted practices. This paper describes the progress and experience gained at the Long Beach Unit, Wilmington, CA alkaline pilot dealing with scales formed in producing wells. These scales have been made up variously of calcium carbonate, magnesium silicate, and amorphous silica. In particular, the reservoir characteristics and chemical conditions leading to the scale formation are discussed in detail showing what, how, and why the scale forms. For the Wilmington alkaline pilot, the mixing during production of very hard waters from one subzone with moderately alkaline water from other subzones, and the dissolution of formation solids has led to scale formation in producers closest to the alkaline injection.

  15. Peripheral Leptin Regulates Bone Formation

    PubMed Central

    Turner, Russell T.; Kalra, Satya P.; Wong, Carmen P.; Philbrick, Kenneth A.; Lindenmaier, Laurence B.; Boghossian, Stephane; Iwaniec, Urszula T.

    2012-01-01

    Substantial evidence does not support the prevailing view that leptin, acting through a hypothalamic relay, decreases bone accrual by inhibiting bone formation. To clarify the mechanisms underlying regulation of bone architecture by leptin, we evaluated bone growth and turnover in wild type (WT) mice, leptin receptor-deficient db/db mice, leptin-deficient ob/ob mice and ob/ob mice treated with leptin. We also performed hypothalamic leptin gene therapy to determine the effect of elevated hypothalamic leptin levels on osteoblasts. Finally, to determine the effects of loss of peripheral leptin signaling on bone formation and energy metabolism, we used bone marrow (BM) from WT or db/db donor mice to reconstitute the hematopoietic and mesenchymal stem cell compartments in lethally irradiated WT recipient mice. Decreases in bone growth, osteoblast-lined bone perimeter and bone formation rate were observed in ob/ob mice and greatly increased in ob/ob mice following subcutaneous administration of leptin. Similarly, hypothalamic leptin gene therapy increased osteoblast-lined bone perimeter in ob/ob mice. In spite of normal osteoclast-lined bone perimeter, db/db mice exhibited a mild but generalized osteopetrotic-like (calcified cartilage encased by bone) skeletal phenotype and greatly reduced serum markers of bone turnover. Tracking studies and histology revealed quantitative replacement of BM cells following BM transplantation. WT mice engrafted with db/db BM did not differ in energy homeostasis from untreated WT mice or WT mice engrafted with WT BM. Bone formation in WT mice engrafted with WT BM did not differ from WT mice, whereas bone formation in WT mice engrafted with db/db cells did not differ from the low rates observed in untreated db/db mice. In summary, our results indicate that leptin, acting primarily through peripheral pathways, increases osteoblast number and activity. PMID:22887758

  16. Inside-out planet formation

    SciTech Connect

    Chatterjee, Sourav; Tan, Jonathan C. E-mail: jt@astro.ufl.edu

    2014-01-01

    The compact multi-transiting planet systems discovered by Kepler challenge planet formation theories. Formation in situ from disks with radial mass surface density, ?, profiles similar to the minimum mass solar nebula but boosted in normalization by factors ? 10 has been suggested. We propose that a more natural way to create these planets in the inner disk is formation sequentially from the inside-out via creation of successive gravitationally unstable rings fed from a continuous stream of small (?cm-m size) 'pebbles', drifting inward via gas drag. Pebbles collect at the pressure maximum associated with the transition from a magnetorotational instability (MRI)-inactive ('dead zone') region to an inner MRI-active zone. A pebble ring builds up until it either becomes gravitationally unstable to form an ?1 M {sub ?} planet directly or induces gradual planet formation via core accretion. The planet may undergo Type I migration into the active region, allowing a new pebble ring and planet to form behind it. Alternatively, if migration is inefficient, the planet may continue to accrete from the disk until it becomes massive enough to isolate itself from the accretion flow. A variety of densities may result depending on the relative importance of residual gas accretion as the planet approaches its isolation mass. The process can repeat with a new pebble ring gathering at the new pressure maximum associated with the retreating dead-zone boundary. Our simple analytical model for this scenario of inside-out planet formation yields planetary masses, relative mass scalings with orbital radius, and minimum orbital separations consistent with those seen by Kepler. It provides an explanation of how massive planets can form with tightly packed and well-aligned system architectures, starting from typical protoplanetary disk properties.

  17. Star Formation in Satellite Galaxies

    NASA Astrophysics Data System (ADS)

    Gutiérrez, C. M.; Alonso, M. S.; Funes, , J. G.; Ribeiro, M. B.

    2006-08-01

    We present narrowband observations of the H? emission in a sample of 31 satellites orbiting isolated giant spiral galaxies. The sample studied spans the range -19 magformation rates are 0.68 and 3.66 Msolar yr-1, respectively. Maps of the spatial distribution of ionized gas are presented. The star-forming regions show a rich structure in which frequently discrete complexes are imposed over more diffuse structures. In general, the current star formation rates are smaller than the mean values in the past, obtained from the stellar content; this probably indicates a declining rate with time in the generation of new stars. However, the reserve of gas is enough to continue fueling the current levels of star formation activity for at least another Hubble time. Four of the objects (NGC 2718b, NGC 4541e, and NGC 5965a1 and NGC 5965a2) with higher current star formation rates show clear signs of interaction with close companions of comparable brightness at projected distances of 25, 20, and 2 kpc, respectively. The only two galaxies in our sample that do not show star formation activity are members of these interacting systems, and it is unclear if this is a consequence of intrinsic properties (both are early Hubble types) or if it is related to possible disruption of the external parts due to the interaction. In the case of the pair NGC 2718a-2718b there are indications of gas transport between the galaxies. Based on observations with the Vatican Advanced Technology Telescope: the Alice P. Lennon Telescope and the Thomas J. Bannan Astrophysics Facility.

  18. Laser beam pulse formatting method

    DOEpatents

    Daly, T.P.; Moses, E.I.; Patterson, R.W.; Sawicki, R.H.

    1994-08-09

    A method for formatting a laser beam pulse using one or more delay loops is disclosed. The delay loops have a partially reflective beam splitter and a plurality of highly reflective mirrors arranged such that the laser beam pulse enters into the delay loop through the beam splitter and circulates therein along a delay loop length defined by the mirrors. As the laser beam pulse circulates within the delay loop a portion thereof is emitted upon each completed circuit when the laser beam pulse strikes the beam splitter. The laser beam pulse is thereby formatted into a plurality of sub-pulses. The delay loops are used in combination to produce complex waveforms by combining the sub-pulses using additive waveform synthesis. 8 figs.

  19. Rapid gas hydrate formation process

    DOEpatents

    Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.

    2013-01-15

    The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.

  20. Scale formation during alkaline flooding

    SciTech Connect

    Krumrine, P.H.; Brock, G.F.; Mayer, E.M.

    1984-04-01

    Alkaline chemicals in enhanced recovery operations have been and are being used: 1) as preflush agents, 2) with polymers and surfactants, and 3) as a principal recovery agent. In these chemical flooding techniques the reactions of multivalent hardness ions with alkalis to form precipitates are of particular concern. These reactions can be prevented at the injection wells through adequate preflushing and/or the use of good quality softened water; filtration can be used to remove any precipitates. These practices minimize the precipitation and subsequent damage to the well equipment and to the formation around the injectors, and reduce the chance for injectivity impairment. In the formation a host of reactions which significantly alter the injected slug occur including: dissolution, mixing, neutralization, and ion exchange. These may lead to fluid diversion as precipitates form to block high flow channels.

  1. Formation of quasiparallel Alfven solitons

    NASA Technical Reports Server (NTRS)

    Hamilton, R. L.; Kennel, C. F.; Mjolhus, E.

    1992-01-01

    The formation of quasi-parallel Alfven solitons is investigated through the inverse scattering transformation (IST) for the derivative nonlinear Schroedinger (DNLS) equation. The DNLS has a rich complement of soliton solutions consisting of a two-parameter soliton family and a one-parameter bright/dark soliton family. In this paper, the physical roles and origins of these soliton families are inferred through an analytic study of the scattering data generated by the IST for a set of initial profiles. The DNLS equation has as limiting forms the nonlinear Schroedinger (NLS), Korteweg-de-Vries (KdV) and modified Korteweg-de-Vries (MKdV) equations. Each of these limits is briefly reviewed in the physical context of quasi-parallel Alfven waves. The existence of these limiting forms serves as a natural framework for discussing the formation of Alfven solitons.

  2. Star formation in Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Espinosa, J. M. Rodriguez; Rudy, Richard J.; Jones, Barbara

    1987-01-01

    An analysis of the IRAS data for a sample of classical (optically selected) Seyfert galaxies is presented. The IRAS fluxes at 25 micron, 60 micron, and 100 micron are found to be uncorrelated or only very weakly correlated with the UV/Optical continuum flux and the near and mid IR flux at 3.5 and 10 microns. To investigate the possibility that star formation accounts for the far IR flux, the IRAS measurements for the Seyfert galaxies are compared to IRAS observations of a sample of normal spiral galaxies, and a sample of Starburst galaxies. It is shown that the far IR luminosities and far IR colors of Seyfert galaxies are indistinguishable from those of the Starburst galaxies. Besides, normal galaxies are an order of magnitude less luminous than both the Seyfert and the Starburst galaxies. This indicates that star formation produces the bulk of the far infrared emission in Seyfert galaxies.

  3. Engineering biofilm formation and dispersal

    PubMed Central

    Wood, Thomas K.; Hong, Seok Hoon; Ma, Qun

    2011-01-01

    Anywhere water is in the liquid state, bacteria will exist as biofilms, which are complex communities of cells cemented together. Although frequently associated with disease and biofouling, biofilms are also important for engineering applications, such as bioremediation, biocatalysis and microbial fuel cells. Here we review approaches to alter genetic circuits and cell signaling toward controlling biofilm formation, and emphasize utilizing these tools for engineering applications. Based on a better understanding of the genetic basis of biofilm formation, we find that biofilms may be controlled by manipulating extracellular signals and that they may be dispersed using conserved intracellular signals and regulators. Biofilms could also be formed at specific locations where they might be engineered to make chemicals or treat human disease. PMID:21131080

  4. Developmental Pattern Formation in Phases.

    PubMed

    Kicheva, Anna; Briscoe, James

    2015-10-01

    Cells in developing organs undergo a series of changes in their transcriptional state until a complete repertoire of cell types is specified. These changes in cell identity, together with the control of tissue growth, determine the pattern of gene expression in the tissue. Recent studies explore the dynamics of pattern formation during development and provide new insights into the control mechanisms. Changes in morphogen signalling and transcriptional networks control the specification of cell types. This is often followed by a distinct second phase, where pattern is elaborated by tissue growth. Here, we discuss the transitions between distinct phases in pattern formation. We consider the implications of the underlying mechanisms for understanding how reproducible patterns form during development. PMID:26410404

  5. Formation of Ultracold Polar Molecules

    NASA Astrophysics Data System (ADS)

    Taylor-Juarros, E.; Côté, R.; Kirby, K.

    2002-05-01

    A variety of experimental techniques have been employed to create a number of ultracold molecules, including CaH, Na_2, K_2, Cs_2, Rb2 and CO. Novel effects are predicted to occur in samples of ultracold polar molecules.(L. Santos et al.), Phys. Rev. Lett. 85, 1791 (2000). We present calculations of the formation rate of ultracold hydrides (LiH, NaH, KH, RbH, and CsH), using the most accurate molecular potentials and dipole moments available. We show that these polar molecules can be produced in selected vibrational and rotational states by stimulated radiative association in a mixture of ultracold hydrogen and alkali metal atoms. We study the properties of these atomic mixtures as well as those of the hydrides, and explore the effect of shape resonances on the formation rates. [2ex] *Supported by NSF

  6. Multiwavelength star formation indicators: Observations

    E-print Network

    H. R. Schmitt; D. Calzetti; L. Armus; M. Giavalisco; T. M. Heckman; R. C. Kennicutt Jr.; C. Leitherer; G. R. Meurer

    2006-02-03

    We present a compilation of multiwavelength data on different star formation indicators for a sample of nearby star forming galaxies. Here we discuss the observations, reductions and measurements of ultraviolet images obtained with STIS, on board the Hubble Space Telescope, ground-based Halpha, and VLA 8.46 GHz radio images. These observations are complemented with infrared fluxes, as well as large aperture optical radio and ultraviolet data from the literature. This database will be used in a forthcoming paper to compare star formation rates at different wavebands. We also present spectral energy distributions (SEDs) for those galaxies with at least one far-infrared measurements from ISO, longward of 100 um. These SEDs are divided in two groups, those which are dominated by the far-infrared emission, and those where the contribution from the far-infrared and optical emission is comparable. These SEDs are useful tools to study the properties of high redshift galaxies.

  7. THE BLACK HOLE FORMATION PROBABILITY

    SciTech Connect

    Clausen, Drew; Piro, Anthony L.; Ott, Christian D.

    2015-02-01

    A longstanding question in stellar evolution is which massive stars produce black holes (BHs) rather than neutron stars (NSs) upon death. It has been common practice to assume that a given zero-age main sequence (ZAMS) mass star (and perhaps a given metallicity) simply produces either an NS or a BH, but this fails to account for a myriad of other variables that may effect this outcome, such as spin, binarity, or even stochastic differences in the stellar structure near core collapse. We argue that instead a probabilistic description of NS versus BH formation may be better suited to account for the current uncertainties in understanding how massive stars die. We present an initial exploration of the probability that a star will make a BH as a function of its ZAMS mass, P {sub BH}(M {sub ZAMS}). Although we find that it is difficult to derive a unique P {sub BH}(M {sub ZAMS}) using current measurements of both the BH mass distribution and the degree of chemical enrichment by massive stars, we demonstrate how P {sub BH}(M {sub ZAMS}) changes with these various observational and theoretical uncertainties. We anticipate that future studies of Galactic BHs and theoretical studies of core collapse will refine P {sub BH}(M {sub ZAMS}) and argue that this framework is an important new step toward better understanding BH formation. A probabilistic description of BH formation will be useful as input for future population synthesis studies that are interested in the formation of X-ray binaries, the nature and event rate of gravitational wave sources, and answering questions about chemical enrichment.

  8. Method for fracturing subterranean formations

    SciTech Connect

    Almond, S. W.; Conway, M. W.

    1985-11-19

    The present invention relates to a thermally stable crosslinked gel fracturing fluid for use in the treatment of subterranean formations penetrated by a well bore. The fracturing fluid comprises an aqueous liquid, a gelling agent comprising a selected modified cellulose ether, a crosslinking agent and any additional additives that may be present. The fracturing fluid is thermally stable under shear at temperatures in excess of about 200/sup 0/ F.

  9. Membrane adhesion and domain formation

    E-print Network

    Thomas R. Weikl; Reinhard Lipowsky

    2007-09-23

    We review theoretical results for the adhesion-induced phase behavior of biomembranes. The focus is on models in which the membranes are represented as discretized elastic sheets with embedded adhesion molecules. We present several mechanism that lead to the formation of domains during adhesion, and discuss the time-dependent evolution of domain patterns obtained in Monte-Carlo simulations. The simulated pattern dynamics has striking similarities to the pattern evolution observed during T cell adhesion.

  10. Pattern formation through gravitational instability.

    NASA Astrophysics Data System (ADS)

    Rica, S.

    1995-05-01

    As a consequence of gravitational instability, a spherical nebula creates a well defined pattern of matter. It follows that the largest concentrations of matter - where the planets were probably created - occur at well defined distances following a geometrical progression: the Titius-Bode law for the Solar System. The universality (in the form) of this law is verified for different planetary systems such as: Jupiter, Saturn and Uranus. It is also shown that turbulent vortices can be responsible for the formation of planets.

  11. Formation mechanism for interstellar molecules

    NASA Technical Reports Server (NTRS)

    Harteck, P.; Beaudoin, A.; Reeves, R.

    1973-01-01

    The major ions in the region of the interstellar clouds include H(+) and H2(+). The ions may be formed by photo ionization, cosmic rays, or other processes. The chemistry of H2(+) is considered and reactions involving carbon atoms are described. The formation of nitrogen-containing molecules may occur mainly on interstellar grains. Reactions involving negative ions may also contribute to the production of certain species.

  12. Kinetic models of opinion formation

    E-print Network

    G. Toscani

    2006-05-17

    We introduce and discuss certain kinetic models of (continuous) opinion formation involving both exchange of opinion between individual agents and diffusion of information. We show conditions which ensure that the kinetic model reaches non trivial stationary states in case of lack of diffusion in correspondence of some opinion point. Analytical results are then obtained by considering a suitable asymptotic limit of the model yielding a Fokker-Planck equation for the distribution of opinion among individuals.

  13. ISM Turbulence (and Star Formation)

    E-print Network

    Klessen,Ralf

    abundance hydrogen H 1 1.000.000 deuterium 1H2 1 16 helium He 2 68.000 carbon C 6 420 nitrogen N 7 90 oxygen ---> formation of molecular clouds the first (strong) magnetic fields in the universe summary Taurus #12;fff Star;Ralf Klessen: San Diego, 15.06.2010 Abundances, scaled to 1.000.000 H atoms element atomic number

  14. SCALE FORMATION IN CHRYSOPHYCEAN ALGAE

    PubMed Central

    Brown, R. Malcolm; Franke, Werner W.; Kleinig, Hans; Falk, Heinz; Sitte, Peter

    1970-01-01

    The cell wall of the marine chrysophycean alga Pleurochrysis scherfellii is composed of distinct wall fragments embedded in a gelatinous mass. The latter is a polysaccharide of pectic character which is rich in galactose and ribose. These wall fragments are identified as scales. They have been isolated and purified from the vegetative mother cell walls after zoospore formation. Their ultrastructure is described in an electron microscope study combining sectioning, freeze-etch, and negative staining techniques. The scales consist of a layer of concentrically arranged microfibrils (ribbons with cross-sections of 12 to 25 x 25 to 40 A) and underlying radial fibrils of similar dimensions. Such a network-plate is densely coated with particles which are assumed to be identical to the pectic component. The microfibrils are resistant to strong alkaline treatment and have been identified as cellulose by different methods, including sugar analysis after total hydrolysis, proton resonance spectroscopical examination (NMR spectroscopy) of the benzoylated product, and diverse histochemical tests. The formation and secretion of the scales can be followed along the maturing Golgi cisternae starting from a pronounced dilated "polymerization center" as a completely intracisternal process which ends in the exocytotic extrusion of the scales. The scales reveal the very same ultrastructure within the Golgi cisternae as they do in the cell wall. The present finding represents the first evidence on cellulose formation by the Golgi apparatus and is discussed in relation to a basic scheme for cellulose synthesis in plant cells in general. PMID:5513606

  15. Theory of Planetary System Formation

    NASA Technical Reports Server (NTRS)

    Cassen, Patrick

    1996-01-01

    Observations and theoretical considerations support the idea that the Solar System formed by the collapse of tenuous interstellar matter to a disk of gas and dust (the primitive solar nebula), from which the Sun and other components separated under the action of dissipative forces and by the coagulation of solid material. Thus, planets are understood to be contemporaneous byproducts of star formation. Because the circumstellar disks of new stars are easier to observe than mature planetary systems, the possibility arises that the nature and variety of planets might be studied from observations of the conditions of their birth. A useful theory of planetary system formation would therefore relate the properties of circumstellar disks both to the initial conditions of star formation and to the consequent properties of planets to those of the disk. Although the broad outlines of such a theory are in place, many aspects are either untested, controversial, or otherwise unresolved; even the degree to which such a comprehensive theory is possible remains unknown.

  16. Supernova Feedback in Galaxy Formation

    NASA Astrophysics Data System (ADS)

    Dubois, Y.; Teyssier, R.

    2008-06-01

    The hierarchical model of galaxy formation is known to suffer from the ``over-cooling'' problem: the high efficiency of radiative cooling results in too much baryonic matter in a condensed phase (namely, cold gas or stars) when compared to observations. A solution proposed by many authors (see Springel & Hernquist 2003; Fujita et al. 2004; Rasera & Teyssier 2005) is feedback due to supernova (SN) driven winds or active galactic nuclei. Modeling SN feedback by direct injection of thermal energy usually turns out to be inefficient in galaxy-scale simulations, due to the quasi-instantaneous radiation of the SN energy. To avoid this effect, we have developed a new method to incorporate SN feedback in cosmological simulations: using temporary test particles, we reproduce explicitly a local Sedov blast wave solution in the gas distribution. We have performed several self-consistent runs of isolated Navarro, Frenk, & White (1996, hereafter NFW) halos with radiative cooling, star formation, SN feedback and metal enrichment using the adaptive mesh refinement code RAMSES (Teyssier 2002). We have explored the influence of SN feedback on the formation and the evolution of galaxies with different masses. We have studied the efficiency of the resulting galactic winds, as a function of the mass of the parent halo.

  17. Memory Formation Shaped by Astroglia

    PubMed Central

    Zorec, Robert; Horvat, Anemari; Vardjan, Nina; Verkhratsky, Alexei

    2015-01-01

    Astrocytes, the most heterogeneous glial cells in the central nervous system (CNS), execute a multitude of homeostatic functions and contribute to memory formation. Consolidation of synaptic and systemic memory is a prolonged process and hours are required to form long-term memory. In the past, neurons or their parts have been considered to be the exclusive cellular sites of these processes, however, it has now become evident that astrocytes provide an important and essential contribution to memory formation. Astrocytes participate in the morphological remodeling associated with synaptic plasticity, an energy-demanding process that requires mobilization of glycogen, which, in the CNS, is almost exclusively stored in astrocytes. Synaptic remodeling also involves bidirectional astroglial-neuronal communication supported by astroglial receptors and release of gliosignaling molecules. Astroglia exhibit cytoplasmic excitability that engages second messengers, such as Ca2+, for phasic, and cyclic adenosine monophosphate (cAMP), for tonic signal coordination with neuronal processes. The detection of signals by astrocytes and the release of gliosignaling molecules, in particular by vesicle-based mechanisms, occurs with a significant delay after stimulation, orders of magnitude longer than that present in stimulus–secretion coupling in neurons. These particular arrangements position astrocytes as integrators ideally tuned to support time-dependent memory formation. PMID:26635551

  18. A New Spoke Formation Model

    NASA Astrophysics Data System (ADS)

    Jones, Geraint H.; Krupp, N.; Krueger, H.; Roussos, E.; Ip, W.; Mitchell, D. G.; Krimigis, S. M.; Woch, J.; Lagg, A.; Fraenz, M.; Dougherty, M. K.; Arridge, C. S.; McAndrews, H. J.

    2006-09-01

    We propose a new model for the formation of spokes in Saturn's rings. The model involves the electrostatic charging of sub-micron dust grains in the rings by magnetic field-aligned electron beams. Such beams have recently been observed by the MIMI instrument aboard Cassini at 3.1 Saturn radii, outside the main ring system. It is reasonable to expect the beams to also occur closer to the planet. We contend that on striking the rings, the electron beams’ dust-charging effects cause the levitation of the fine grains above the main ring plane, forming the spokes. Using a semi-quantitative model, we explain the spokes’ formation locations, their initial morphologies, and the subsequent development of their appearance as reported in studies based on Voyager observations. Controlling effects on the spokes’ locations are also proposed. We outline tests that can be carried out using Cassini datasets to gauge the validity of our proposed formation process. MIMI/LEMMS work at MPS is financed by the German Bundesministerium für Bildung und Forschung, and by the Max Planck Gesellschaft.

  19. Formation of the hurricane eye

    NASA Astrophysics Data System (ADS)

    Vigh, Jonathan L.

    This dissertation consists of three distinct studies which investigate aspects of eye formation. The first study reviews eye phenomenon in a variety of vortices ranging from simple vortices to the menagerie of geophysical vortices, emphasizing similarities and differences to the eyes formed in hurricanes. The hurricane eye is found to be a paradoxical structure imposed by conservation of angular momentum and the boundaries of the vortex. A comprehensive definition for hurricane eye formation is proposed and various eye formation mechanisms are summarized. The next study presents a simple theoretical argument to isolate the conditions under which a tropical cyclone can rapidly develop a warm-core thermal structure and subsequently approach a steady state. The theoretical argument is based on the balanced vortex model and, in particular, on the associated transverse circulation equation and the geopotential tendency equation. The transverse circulation and the temperature tendency in a tropical vortex depend not only on the diabatic forcing, but also on the spatial distributions of the static stability, the baroclinity, and the inertial stability. The vortex response to diabatic heating depends critically on whether the heating occurs in the low inertial stability region outside the radius of maximum wind or in the high inertial stability region inside the radius of maximum wind. This result suggests that rapid intensification is favored for storms which have at least some of the eyewall convection inside the radius of maximum wind. The development of an eye partially removes diabatic heating from the high inertial stability region of the storm center, yet rapid intensification may continue if the eyewall heating continues to become more efficient. As the warm core matures and static stability increases over the inner core, conditions there become less favorable for deep upright convection and the storm tends to approach a steady state. The final study characterizes the kinematic and thermodynamic changes that occur before, during, and after the initial eye formations of a broad set of Atlantic tropical cyclones. To obtain the requisite structure and intensity parameters, a new data set has been synthesized from the Vortex Data Messages transmitted by routine aircraft reconnaissance from 1989--2008. Intensity ranges are determined for the times when the eye/eyewall structure first appears in aircraft radar and infrared satellite imagery. The mean intensity at which an eye is first observed in both aircraft or satellite imagery is found to be 58 kt, somewhat lower than reported in previous studies. Changes about the time of eye formation are examined for intensity, the radius of maximum winds, the minimum Rossby radius of deformation, eye temperature and dew point temperature depression. Storms are found to intensify most rapidly near the time of eye formation, especially when a persistent eye is observed in infrared satellite imagery. Many storms which are forming eyes are found to undergo a substantial and rapid contraction in the radius of maximum winds during the 24-h period before the eye is observed; once the eye is present, this contraction slows or ceases. Strong warming at lower levels (850 or 700 hPa) of the eye is not observed to correlate well with the time in which the eye is first observed. Finally, observations suggest that the dynamical heating efficiency of the resulting eyewall increases even as the physical scale of the efficient heating region decreases. This allows the storm to continue intensifying even though the total inner core diabatic heating may decrease. The answer to why some storms fail to form eyes may shed light on whether eye formation is a stochastic process involving constructive and destructive mesoscale interactions---or whether it is a manifold attractor of the system sometimes stymied by an unfavorable environment.

  20. THE FORMATION OF LIFE Robert L. Kurucz

    E-print Network

    Kurucz, Robert L.

    THE FORMATION OF LIFE Robert L. Kurucz Harvard-Smithsonian Center for Astrophysics November 7, 2000 Revised October 15, 2008; November 20, 2011 #12;THE FORMATION OF LIFE Robert L. Kurucz Harvard-Smithsonian

  1. XML Format for SESAME and LEOS

    SciTech Connect

    Durrenberger, J K; Neely, J R; Sterne, P A

    2009-04-29

    The objective of this document is to describe the XML format used by LLNL and LANL to represent the equation-of-state and related material information in the LEOS and SESAME data libraries. The primary purpose of this document is to describe a specific XML format for representing EOS data that is tailored to the nature of the underlying data and is amenable to conversion to both legacy SESAME and LEOS binary formats. The secondary purpose is to describe an XML format that lends itself to a 'natural' representation in a binary file format of the SESAME, pdb or hdf5 form so that this format and related tools can be used for the rapid and efficient development and implementation of prototype data structures. This document describes the XML format only. A working knowledge of LEOS and SESAME formats is assumed.

  2. Dynamics and control of electromagnetic satellite formations

    E-print Network

    Ahsun, Umair, 1972-

    2007-01-01

    Satellite formation flying is an enabling technology for many space missions, especially for space-based telescopes. Usually there is a tight formation-keeping requirement that may need constant expenditure of fuel or at ...

  3. Gas-Phase Infrared; JCAMP Format

    National Institute of Standards and Technology Data Gateway

    SRD 35 NIST/EPA Gas-Phase Infrared; JCAMP Format (PC database for purchase)   This data collection contains 5,228 infrared spectra in the JCAMP-DX (Joint Committee for Atomic and Molecular Physical Data "Data Exchange") format.

  4. NCI Best Case Summary Format-OCCAM

    Cancer.gov

    The following is a sample Case Report Format used to submit BCS Case Summaries Please adhere to the suggestions below. You may alter the format but include as much of the indicated content as possible.

  5. 49 CFR 563.8 - Data format

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Transportation 6 2010-10-01 2010-10-01 false Data format 563.8 Section 563.8 Transportation...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EVENT DATA RECORDERS § 563.8 Data format (a) The data elements listed in...

  6. SAR polar format implementation with MATLAB.

    SciTech Connect

    Martin, Grant D.; Doerry, Armin Walter

    2005-11-01

    Traditional polar format image formation for Synthetic Aperture Radar (SAR) requires a large amount of processing power and memory in order to accomplish in real-time. These requirements can thus eliminate the possible usage of interpreted language environments such as MATLAB. However, with trapezoidal aperture phase history collection and changes to the traditional polar format algorithm, certain optimizations make MATLAB a possible tool for image formation. Thus, this document's purpose is two-fold. The first outlines a change to the existing Polar Format MATLAB implementation utilizing the Chirp Z-Transform that improves performance and memory usage achieving near realtime results for smaller apertures. The second is the addition of two new possible image formation options that perform a more traditional interpolation style image formation. These options allow the continued exploration of possible interpolation methods for image formation and some preliminary results comparing image quality are given.

  7. Treating nahcolite containing formations and saline zones

    DOEpatents

    Vinegar, Harold J

    2013-06-11

    A method for treating a nahcolite containing subsurface formation includes removing water from a saline zone in or near the formation. The removed water is heated using a steam and electricity cogeneration facility. The heated water is provided to the nahcolite containing formation. A fluid is produced from the nahcolite containing formation. The fluid includes at least some dissolved nahcolite. At least some of the fluid is provided to the saline zone.

  8. Star formation laws, rates, thresholds in galaxies

    NASA Astrophysics Data System (ADS)

    Karoline Walch, Stefanie

    2015-08-01

    Star formation at galactic scales is subject to a number of scaling relations, which are motivated by observations. I will review the theoretical ideas that could explain these and bring put them in context with a modern view of the multi-phase, turbulent interstellar medium. I will address the questions: Is molecular gas important for star formation? What physical processes regulate star formation on galactic scales? Is there a surface density threshold for star formation? How important is the galactic environment?

  9. Formation and evolution of disk galaxies

    E-print Network

    Joseph Silk

    2008-09-02

    Global star formation is the key to understanding galaxy disk formation. This in turn depends on gravitational instability of disks and continuing gas accretion as well as minor merging. A key component is feedback from supernovae. Primary observational constraints on disk galaxy formation and evolution include the Schmidt-Kennicutt law, the Tully-Fisher relation and the galaxy luminosity function. I will review how theory confronts phenomenology, and discuss future prospects for refining our understanding of disk formation.

  10. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium formate. 186.1756 Section 186.1756 Food and....1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with sodium hydroxide. (b) The ingredient...

  11. Formative Constructs Implemented via Common Factors

    ERIC Educational Resources Information Center

    Treiblmaier, Horst; Bentler, Peter M.; Mair, Patrick

    2011-01-01

    Recently there has been a renewed interest in formative measurement and its role in properly specified models. Formative measurement models are difficult to identify, and hence to estimate and test. Existing solutions to the identification problem are shown to not adequately represent the formative constructs of interest. We propose a new two-step…

  12. 48 CFR 333.212-70 - Formats.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Formats. 333.212-70 Section 333.212-70 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES GENERAL CONTRACTING REQUIREMENTS PROTESTS, DISPUTES, AND APPEALS Disputes and Appeals 333.212-70 Formats. (a) Contracting activities shall use the following format...

  13. Transfer of Training with Formation Flight Trainer.

    ERIC Educational Resources Information Center

    Reid, Gary B.; Cyrus, Michael L.

    The present research was conducted to determine transfer of practice from a formation simulator to actual aircraft flight for the wing aircraft component of the formation flying task. Evidence in support of positive transfer was obtained by comparing students trained in the formation simulator with students who were essentially untrained and with…

  14. Composition and method of stimulating subterranean formations

    SciTech Connect

    Dill, W.R.; Walker, M.L.; Ford, G.F.

    1987-07-14

    This patent describes a method of treating a subterranean formation containing iron comprising contacting a subterranean formation with an aqueous fluid containing a compound consisting essentially of at least one member selected from the group consisting of: dihydroxymaleic acid, salts of dihydroxymaleic acid, glucono-deltalactone present in an amount sufficient to prevent the precipitation of ferric iron during contact with the subterranean formation.

  15. PALAEODIVERSITY AND FORMATION COUNTS: REDUNDANCY OR BIAS?

    E-print Network

    Benton, Michael

    comprises finds from Europe and North America, where new formation discoveries reached their half-life outside Europe and North America and the formation half-life for these `new' lands is 1986, showing vertebrates at least, formation counts of various kinds are poor predictors of sampling, missing, for example

  16. Successful Student Writing through Formative Assessment

    ERIC Educational Resources Information Center

    Tuttle, Harry Grover

    2010-01-01

    Use formative assessment to dramatically improve your students' writing. In "Successful Student Writing Through Formative Assessment", educator and international speaker Harry G. Tuttle shows you how to guide middle and high school students through the prewriting, writing, and revision processes using formative assessment techniques that work.…

  17. 7 CFR 1755.407 - Data formats.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Data formats. 1755.407 Section 1755.407 Agriculture... TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.407 Data formats. The following suggested formats listed in this section may be used for recording the test...

  18. 7 CFR 1755.407 - Data formats.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Data formats. 1755.407 Section 1755.407 Agriculture... TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.407 Data formats. The following suggested formats listed in this section may be used for recording the test...

  19. 7 CFR 1755.407 - Data formats.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Data formats. 1755.407 Section 1755.407 Agriculture... TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.407 Data formats. The following suggested formats listed in this section may be used for recording the test...

  20. 7 CFR 1755.407 - Data formats.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Data formats. 1755.407 Section 1755.407 Agriculture... TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.407 Data formats. The following suggested formats listed in this section may be used for recording the test...

  1. 7 CFR 1755.407 - Data formats.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 11 2014-01-01 2014-01-01 false Data formats. 1755.407 Section 1755.407 Agriculture... TELECOMMUNICATIONS POLICIES ON SPECIFICATIONS, ACCEPTABLE MATERIALS, AND STANDARD CONTRACT FORMS § 1755.407 Data formats. The following suggested formats listed in this section may be used for recording the test...

  2. Word Formation: The Anarchy of the Art.

    ERIC Educational Resources Information Center

    Beard, Robert

    This is a state-of-the-art review of word formative morphology. The paper surveys three loosely knit 'schools' of word formation: (1) the Generative school, (2) the Continental school, and (3) the Slavicist school. It points out that much work in word formation is being duplicated because of a lack of coordination and communication between the…

  3. A new PICL trace file format

    SciTech Connect

    Worley, P.H.

    1992-10-01

    A trace file format is described that will be used in future releases of the Portable Instrumented Communication Library (PICL) and ParaGraph. The new format provides improved support for tracing and profiling PICL communication primitives and user-defined events. The new format is also easily extended and may be useful in other instrumentation packages and performance visualization tools.

  4. Diet History Questionnaire II: Size Formats

    Cancer.gov

    Two serving size formats are used on the NCI versions of the DHQ as shown below. Format 1 is used for nearly all serving size questions. Format 2 is used only in special cases, where 'never' is allowed as a response.

  5. Brown dwarf formation in clusters Matthew Bate

    E-print Network

    Joergens, Viki

    Brown dwarf formation in clusters Matthew Bate University of Exeter #12;· Bate, Bonnell & Bromm · Resolved binaries with · separations >1 AU · disc with radii >10 AU · Produced 23 stars & 27 brown dwarfs disc First cluster formation calculation to resolve brown dwarfs #12;Brown dwarf formation · How do

  6. Electromagnetic Formation Flight of Satellite Arrays

    E-print Network

    Electromagnetic Formation Flight of Satellite Arrays Daniel W. Kwon and David W. Miller February 2005 SSL # 2-05 #12;#12;Electromagnetic Formation Flight of Satellite Arrays By DANIEL W. KWON S;#12;Electromagnetic Formation Flight of Satellite Arrays by DANIEL W. KWON Submitted to the Department of Aeronautics

  7. Supermassive Black Holes and Galaxy Formation

    E-print Network

    Joseph Silk

    2001-09-19

    The formation of supermassive black holes (SMBH) is intimately related to galaxy formation, although precisely how remains a mystery. I speculate that formation of, and feedback from, SMBH may alleviate problems that have arisen in our understanding of the cores of dark halos of galaxies.

  8. Some Current Issues in Galaxy Formation

    E-print Network

    Joseph Silk

    2004-01-06

    I describe recent challenges in hierarchical galaxy formation theory, including the formation of disk galaxies and of ellipticals. Problems with cold dark matter are summarized, and possible solutions are presented. I conclude with a description of the prospects for observing one of the most important ingredients in galaxy formation theory, namely cold dark matter.

  9. String Formatting Considered Harmful for Novice Programmers

    ERIC Educational Resources Information Center

    Hughes, Michael C.; Jadud, Matthew C.; Rodrigo, Ma. Mercedes T.

    2010-01-01

    In Java, "System.out.printf" and "String.format" consume a specialised kind of string commonly known as a format string. In our study of first-year students at the Ateneo de Manila University, we discovered that format strings present a substantial challenge for novice programmers. Focusing on their first laboratory we found that 8% of all the…

  10. Feedback During Massive Star Formation

    NASA Astrophysics Data System (ADS)

    Tanaka, Kei; Tan, Jonathan C.; Zhang, Yichen

    2016-01-01

    We present models of photoionization of massive protostellar cores, and show the impact of this ionization feedback on the efficiency of star formation and its observational features. Based on the Core Accretion scenario, we construct the collapse model of rotating massive-protostellar cloud cores together with a protostellar evolutional calculation, including feedback effects from a MHD disk wind, photoionization and radiation pressure. First, the MHD wind creates a bipolar outflow whose opening angle increases over the timescale of mass accretion. The ionizing luminosity dramatically increases after the protostar reaches ~ 5 Msun due to Kelvin-Helmholz contraction, and the MHD wind is photoionized when the protostellar mass reaches ~ 10 - 20 Msun. As the ionizing and bolometric luminosities increase, the outflow opening angle becomes wider due to radiation pressure feedback. By this combination of feedback processes, the envelope is eroded and the mass infall rate is significantly reduced to that arriving only from the disk-shielded equatorial region. At a protostellar mass of ~ 50 - 100 Msun, depending on the initial core properties, the mass accretion is halted by disk photoevaporation. In this way, feedback significantly reduces the star formation efficiency when forming massive stars from massive cloud cores, which could produce a cutoff at the high-mass end of the initial mass function. Along this evolutionary calculation, we also compute the detailed structure of the photoionized regions using a ray-tracing radiative transfer code and evaluate their emission signatures. Their free-free continuum and recombination line emissions are consistent with the variety of observed radio sources associated with massive protostars, i.e., jets and ultra/hyper-compact HII regions. The comparison between our models and such observations enables us to better define the evolutionary sequence of massive star formation.

  11. Formation of Kuiper Belt Binaries

    E-print Network

    Peter Goldreich; Yoram Lithwick; Re'em Sari

    2002-08-28

    It appears that at least several percent of large Kuiper belt objects are members of wide binaries. Physical collisions are too infrequent to account for their formation. Collisionless gravitational interactions are more promising. These provide two channels for binary formation. In each, the initial step is the formation of a transient binary when two large bodies penetrate each other's Hill spheres. Stabilization of a transient binary requires that it lose energy. Either dynamical friction due to small bodies or the scattering of a third large body can be responsible. Our estimates favor the former, albeit by a small margin. We predict that most objects of size comparable to those currently observed in the Kuiper belt are members of multiple systems. More specifically, we derive the probability that a large body is a member of a binary with semi-major axis of order a. The probability depends upon sigma, the total surface density, Sigma, the surface density of large bodies having radius R, and theta=10^-4, the angle subtended by the solar radius as seen from the Kuiper belt. For (sigma/Sigma)RKuiper belt, we estimate Sigma/rho=3 10^-4cm and R=100km. We obtain sigma/rho=0.3cm by extrapolating the surface density deduced for the minimum mass solar nebula. Rough predictions are: outside of the critical separation r_u/a_odot=3'', the binary probability is 0.3%; at separations of 0.2'', comparable to current resolving capabilities, it reaches 5%, in agreement with results from the HST binary survey by Brown.

  12. Dust formation by failed supernovae

    NASA Astrophysics Data System (ADS)

    Kochanek, C. S.

    2014-11-01

    We consider dust formation during the ejection of the hydrogen envelope of a red supergiant during a failed supernova (SN) creating a black hole. While the dense, slow moving ejecta are very efficient at forming dust, only the very last phases of the predicted visual transient will be obscured. The net grain production consists of Md ˜ 10- 2 M? of very large grains (10-1000 ?m). This means that failed SNe could be the source of the very large extrasolar dust grains possibly identified by Ulysses, Galileo and radar studies of meteoroid re-entry trails rather than their coming from an ejection process associated with protoplanetary or other discs.

  13. Cosmological Acceleration from Structure Formation

    NASA Astrophysics Data System (ADS)

    Räsänen, Syksy

    We discuss the Buchert equations, which describe the average expansion of an inhomogeneous dust universe. In the limit of small perturbations, they reduce to the Friedmann-Robertson-Walker equations. However, when the universe is very inhomogeneous, the behavior can be qualitatively different from the FRW case. In particular, the average expansion rate can accelerate even though the local expansion rate decelerates everywhere. We clarify the physical meaning of this paradoxical feature with a simple toy model, and demonstrate how acceleration is intimately connected with gravitational collapse. This provides a link to structure formation, which in turn has a preferred time around the era when acceleration has been observed to start.

  14. Tube formation in fluid membranes

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Sknepnek, Rastko; Schwarz, Jennifer; Bowick, Mark

    2014-03-01

    Consider a point force pulling on a fluid membrane. As the magnitude of the force increases, there is a first-order shape transition from nontubular to tubular with a force barrier in between. Motivated by tube formation in endocytosis in yeast, we generalize this problem by including additional force components and steric interactions. Both new ingredients are a consequence of the underlying actin cytoskeletal network, which exerts active forces on the cell membrane to deform it into a tube. We study this generalized problem using variational and Monte Carlo methods in order to quantify endocytosis in yeast.

  15. Electrochemical formation of field emitters

    DOEpatents

    Bernhardt, Anthony F. (Berkeley, CA)

    1999-01-01

    Electrochemical formation of field emitters, particularly useful in the fabrication of flat panel displays. The fabrication involves field emitting points in a gated field emitter structure. Metal field emitters are formed by electroplating and the shape of the formed emitter is controlled by the potential imposed on the gate as well as on a separate counter electrode. This allows sharp emitters to be formed in a more inexpensive and manufacturable process than vacuum deposition processes used at present. The fabrication process involves etching of the gate metal and the dielectric layer down to the resistor layer, and then electroplating the etched area and forming an electroplated emitter point in the etched area.

  16. Formation Flying and Deformable Instruments

    SciTech Connect

    Rio, Yvon

    2009-05-11

    Astronomers have always attempted to build very stable instruments. They fight all that can cause mechanical deformation or image motion. This has led to well established technologies (autoguide, active optics, thermal control, tip/tilt correction), as well as observing methods based on the use of controlled motion (scanning, micro scanning, shift and add, chopping and nodding). Formation flying disturbs this practice. It is neither possible to reduce the relative motion to very small amplitudes, nor to control it at will. Some impacts on Simbol-X instrument design, and operation are presented.

  17. Petrophysical evaluation of subterranean formations

    DOEpatents

    Klein, James D; Schoderbek, David A; Mailloux, Jason M

    2013-05-28

    Methods and systems are provided for evaluating petrophysical properties of subterranean formations and comprehensively evaluating hydrate presence through a combination of computer-implemented log modeling and analysis. Certain embodiments include the steps of running a number of logging tools in a wellbore to obtain a variety of wellbore data and logs, and evaluating and modeling the log data to ascertain various petrophysical properties. Examples of suitable logging techniques that may be used in combination with the present invention include, but are not limited to, sonic logs, electrical resistivity logs, gamma ray logs, neutron porosity logs, density logs, NRM logs, or any combination or subset thereof.

  18. Zonal flow as pattern formation

    SciTech Connect

    Parker, Jeffrey B.; Krommes, John A.

    2013-10-15

    Zonal flows are well known to arise spontaneously out of turbulence. We show that for statistically averaged equations of the stochastically forced generalized Hasegawa-Mima model, steady-state zonal flows, and inhomogeneous turbulence fit into the framework of pattern formation. There are many implications. First, the wavelength of the zonal flows is not unique. Indeed, in an idealized, infinite system, any wavelength within a certain continuous band corresponds to a solution. Second, of these wavelengths, only those within a smaller subband are linearly stable. Unstable wavelengths must evolve to reach a stable wavelength; this process manifests as merging jets.

  19. Heating tar sands formations while controlling pressure

    DOEpatents

    Stegemeier, George Leo (Houston, TX) [Houston, TX; Beer, Gary Lee (Houston, TX) [Houston, TX; Zhang, Etuan (Houston, TX) [Houston, TX

    2010-01-12

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. A pressure in the majority of the section may be maintained below a fracture pressure of the formation. The pressure in the majority of the section may be reduced to a selected pressure after the average temperature reaches a temperature that is above 240.degree. C. and is at or below pyrolysis temperatures of hydrocarbons in the section. At least some hydrocarbon fluids may be produced from the formation.

  20. Scale formation during Alkaline flooding

    SciTech Connect

    Krumrine, P.H.; Craton, G.M.

    1985-08-01

    Alkaline chemicals in enhanced recovery operations are used as preflush agents, with polymers and surfactants, and as a principal recovery agent. In these chemical flooding techniques, the precipitation reactions of multivalent hardness ions with alkalis are of particular concern. These reactions may be prevented at the injection wells through adequate preflushing and/or the use of good-quality softened water; filtration can remove any precipitates that form at the surface. In the formation, many reactions occur that alter the injected slug significantly. These include dissolution, mixing, neutralization, and ion exchange. Such reactions may lead to beneficial fluid diversion as precipitates form and block high-flow channels. At the producing wells, however, precipitation and deposition phenomena are undesirable because scales may form that restrict production and foul well equipment. With the current higher concentrations of alkali being used in the field, the development of well scaling has become noticeable and difficult to control by previously accepted practices. This paper describes the progress and experience gained at the Long Beach Unit, Wilmington, CA, alkaline pilot dealing with scales formed in producing wells. These scales have been made up variously of calcium carbonate, magnesium silicate, and amorphous silica. In particular, the reservoir characteristics and chemical conditions leading to the scale formation are discussed in detail, showing what, how, and why the scale forms.

  1. BAR FORMATION FROM GALAXY FLYBYS

    SciTech Connect

    Lang, Meagan; Holley-Bockelmann, Kelly; Sinha, Manodeep E-mail: k.holley@vanderbilt.edu

    2014-08-01

    Recently, both simulations and observations have revealed that flybys—fast, one-time interactions between two galaxy halos—are surprisingly common, nearing/comparable to galaxy mergers. Since these are rapid, transient events with the closest approach well outside the galaxy disk, it is unclear if flybys can transform the galaxy in a lasting way. We conduct collisionless N-body simulations of three coplanar flyby interactions between pure-disk galaxies to take a first look at the effects flybys have on disk structure, with particular focus on stellar bar formation. We find that some flybys are capable of inciting a bar with bars forming in both galaxies during our 1:1 interaction and in the secondary during our 10:1 interaction. The bars formed have ellipticities ? 0.5, sizes on the order of the host disk's scale length, and persist to the end of our simulations, ?5 Gyr after pericenter. The ability of flybys to incite bar formation implies that many processes associated with secular bar evolution may be more closely tied with interactions than previously thought.

  2. Possible mechanisms of macrolayer formation

    SciTech Connect

    Sadasivan, P.; Chappidi, P.R.; Unal, C.; Nelson, R.A.

    1992-05-01

    The high heat flux nucleate boiling region, also called the vapor mushroom region, has been shown to have a thin liquid layer on the heater surface under the large mushroom-shaped vapor bubbles that grow from the heater surface. The name given to this liquid layer is the macrolayer to differentiate it from the microlayer that exists under the discrete bubbles found at lower heat fluxes in the nucleate boiling region. Typical thicknesses of this macrolayer range from 50 to 500 {mu}m for water on a flat horizontal boiling surface and depend upon the heat flux. Thus, the macrolayer is thicker than the wedge-shaped microlayers, found under discrete bubbles, which range in thickness from 1 to 10 {mu}m. Although the mechanism of microlayer formation and its evaporation is conceptually simple that of the macrolayer is still not understood. This paper critically compares the potential mechanisms proposed for macrolayer formation. These mechanisms include the Helmholtz instability applied to the vapor stem above active nucleation sites, liquid trapped by lateral coalescence of discrete bubbles that initially form during the mushroom bubble`s waiting period, and the limitation of liquid resupply at mushroom departure as a result of vapor flow from the active nucleation sites.

  3. Possible mechanisms of macrolayer formation

    SciTech Connect

    Sadasivan, P.; Chappidi, P.R.; Unal, C.; Nelson, R.A.

    1992-01-01

    The high heat flux nucleate boiling region, also called the vapor mushroom region, has been shown to have a thin liquid layer on the heater surface under the large mushroom-shaped vapor bubbles that grow from the heater surface. The name given to this liquid layer is the macrolayer to differentiate it from the microlayer that exists under the discrete bubbles found at lower heat fluxes in the nucleate boiling region. Typical thicknesses of this macrolayer range from 50 to 500 {mu}m for water on a flat horizontal boiling surface and depend upon the heat flux. Thus, the macrolayer is thicker than the wedge-shaped microlayers, found under discrete bubbles, which range in thickness from 1 to 10 {mu}m. Although the mechanism of microlayer formation and its evaporation is conceptually simple that of the macrolayer is still not understood. This paper critically compares the potential mechanisms proposed for macrolayer formation. These mechanisms include the Helmholtz instability applied to the vapor stem above active nucleation sites, liquid trapped by lateral coalescence of discrete bubbles that initially form during the mushroom bubble's waiting period, and the limitation of liquid resupply at mushroom departure as a result of vapor flow from the active nucleation sites.

  4. Coring in deep hardrock formations

    SciTech Connect

    Drumheller, D.S.

    1988-08-01

    The United States Department of Energy is involved in a variety of scientific and engineering feasibility studies requiring extensive drilling in hard crystalline rock. In many cases well depths extend from 6000 to 20,000 feet in high-temperature, granitic formations. Examples of such projects are the Hot Dry Rock well system at Fenton Hill, New Mexico and the planned exploratory magma well near Mammoth Lakes, California. In addition to these programs, there is also continuing interest in supporting programs to reduce drilling costs associated with the production of geothermal energy from underground sources such as the Geysers area near San Francisco, California. The overall progression in these efforts is to drill deeper holes in higher temperature, harder formations. In conjunction with this trend is a desire to improve the capability to recover geological information. Spot coring and continuous coring are important elements in this effort. It is the purpose of this report to examine the current methods used to obtain core from deep wells and to suggest projects which will improve existing capabilities. 28 refs., 8 figs., 2 tabs.

  5. Supercoil Formation During DNA Melting

    NASA Astrophysics Data System (ADS)

    Sayar, Mehmet; Avsaroglu, Baris; Kabakcioglu, Alkan

    2009-03-01

    Supercoil formation plays a key role in determining the structure-function relationship in DNA. Biological and technological processes, such as protein synthesis, polymerase chain reaction, and microarrays relys on separation of the two strands in DNA, which is coupled to the unwinding of the supercoiled structure. This problem has been studied theoretically via Peyrard-Bishop and Poland-Scheraga type models, which include a simple representation of the DNA structural properties. In recent years, computational models, which provide a more realtistic representaion of DNA molecule, have been used to study the melting behavior of short DNA chains. Here, we will present a new coarse-grained model of DNA which is capable of simulating sufficiently long DNA chains for studying the supercoil formation during melting, without sacrificing the local structural properties. Our coarse-grained model successfully reproduces the local geometry of the DNA molecule, such as the 3'-5' directionality, major-minor groove structure, and the helical pitch. We will present our initial results on the dynamics of supercoiling during DNA melting.

  6. Formation of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; DeVincenzi, Donald L. (Technical Monitor)

    1998-01-01

    An overview of current theories of the formation of our Solar System, with emphasis on giant planets, is presented. The most detailed models are based upon observations of planets and smaller bodies within our own Solar System and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Larger disk mass allows for faster growth of solid planetary bodies. The ability of a solid planet to trap gas from the protoplanetary disk increases rapidly as its mass increases (because the depth of its gravitational potential well increases), but decreases as the planetesimal accretion rate is increased (as it becomes hotter). The net effect of increasing disk mass is that gas giant planets form more rapidly, but with larger core masses. Observations of circumstellar disks suggest an upper bound on the time available prior to dissipation of the gas, and planetary models place upper limits on core sizes. Together, these constraints suggest that Jupiter and Saturn formed in 1 - 10 million years, and the density of solids in the region of their formation was a few times as large as the lower bound provided by the traditional minimum mass nebula.

  7. Formation of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Lissauer, Jack J.; Young, Richard E. (Technical Monitor)

    1998-01-01

    An overview of current theories of the formation of our Solar System, with emphasis on giant planets, is presented. The most detailed models are based upon observations of planets and smaller bodies within our own Solar System and of young stars and their environments. Terrestrial planets are believed to grow via pairwise accretion until the spacing of planetary orbits becomes large enough that the configuration is stable for the age of the system. Giant planets begin their growth as do terrestrial planets, but they become massive enough that they are able to accumulate substantial amounts of gas before the protoplanetary disk dissipates. Larger disk mass allows for faster growth of solid planetary bodies. The ability of a solid planet to trap gas from the protoplanetary disk increases rapidly as its mass increases (because the depth of its gravitational potential well increases), but decreases as the planetesimal accretion rate is increased (as it becomes hotter). The net effect of increasing disk mass is that gas giant planets form more rapidly, but with larger core masses. Observations of circumstellar disks suggest an upper bound on the time available prior to dissipation of the gas, and planetary models place upper limits on core sizes. Together, these constraints suggest that Jupiter and Saturn formed in 1-10 million years, and the density of solids in the region of their formation was a few times as large as the lower bound provided by the traditional minimum mass nebula.

  8. Combuster. [low nitrogen oxide formation

    NASA Technical Reports Server (NTRS)

    Mckay, R. A. (inventor)

    1978-01-01

    A combuster is provided for utilizing a combustible mixture containing fuel and air, to heat a load fluid such as water or air, in a manner that minimizes the formation of nitrogen oxide. The combustible mixture passes through a small diameter tube where the mixture is heated to its combustion temperature, while the load fluid flows past the outside of the tube to receive heat. The tube is of a diameter small enough that the combustible mixture cannot form a flame, and yet is not subject to wall quench, so that combustion occurs, but at a temperature less than under free flame conditions. Most of the heat required for heating the combustible mixture to its combustion temperature, is obtained from heat flow through the walls of the pipe to the mixture.

  9. Sandpile formation by revolving rivers.

    PubMed

    Altshuler, E; Ramos, O; Martínez, E; Batista-Leyva, A J; Rivera, A; Bassler, K E

    2003-07-01

    Experimental observation of a new mechanism of sandpile formation is reported. As a steady stream of dry sand is poured onto a horizontal surface, a pile forms which has a thin river of sand on one side flowing from the apex of the pile to the edge of its base. The river rotates about the pile, depositing a new layer of sand with each revolution, thereby causing the pile to grow. For small piles the river is steady and the pile formed is smooth. For larger piles, the river becomes intermittent and the surface of the pile becomes undulating. The essential features of the system that produce the phenomenon are discussed, and the robustness of the phenomena is demonstrated with experiments using different boundary conditions and sands. PMID:12906542

  10. Chondrule formation in lightning discharges

    NASA Technical Reports Server (NTRS)

    Horanyi, M.

    1994-01-01

    Chondrules represent a significant mass fraction of primitive meteorites. These millimeter-sized glassy droplets appear to be the products of intensive transient heating events. Their size distribution, chemical and mineral composition, texture, isotope composition suggest that chondrules were produced as a result of short-duration melting followed by rapid cooling of solid precursor particles. Gas-dynamics heating, magnetic reconnection, and electrostatic discharges are thought to be the leading candidates to explain chondrule formation. In this paper we summarize our recent theoretical progress on the effects of 'lightning' in the early solar system and also report on preliminary results from our laboratory experiments. Differential settling of various sized dust particles toward the midplane of the nebula is suspected to build large-scale charge separations that episodically relax via the electric breakdown of the nebular gas. The electrostatic discharge os analogous to lightning in the Earth's atmosphere.

  11. Formation control for cooperative surveillance 

    E-print Network

    Woo, Sang-Bum

    2009-05-15

    are deflned by substituting ri for r?i in the formation constraints as follows: Ei = 2 64 kri ?rv1k2 ?d2i \\([ri ?rv1]I)?\\([rv2 ?rv1]I)?fii 3 75 = 2 64ei;l ei; 3 75; i = 1;:::;N (2.4) E. Controller Design Sliding mode control can be used for stabilizing...;l +?i;l) ? e2i;l + 2 i;l?i;l ei;l _ei;l + 1+ i;l?i;l i;l?i;l( i;l +?i;l) ? _e2i;l si; = i; +?i; i; ?i; + 1+ i; ?i; ( i; +?i; ) ? e2i; + 2 i; ?i; ei; _ei; + 1+ i; ?i; i; ?i; ( i; +?i; ) ? _e2i; (2.6) where ?i;l > 0, i;l > 0, ?i; > 0...

  12. Pattern formation in colloidal explosions

    E-print Network

    Arthur V. Straube; Ard A. Louis; Jörg Baumgartl; Clemens Bechinger; Roel P. A. Dullens

    2011-07-23

    We study the non-equilibrium pattern formation that emerges when magnetically repelling colloids, trapped by optical tweezers, are abruptly released, forming colloidal explosions. For multiple colloids in a single trap we observe a pattern of expanding concentric rings. For colloids individually trapped in a line, we observe explosions with a zigzag pattern that persists even when magnetic interactions are much weaker than those that break the linear symmetry in equilibrium. Theory and computer simulations quantitatively describe these phenomena both in and out of equilibrium. An analysis of the mode spectrum allows us to accurately quantify the non-harmonic nature of the optical traps. Colloidal explosions provide a new way to generate well-characterized non-equilibrium behaviour in colloidal systems.

  13. Macromolecules Relevant to Stone Formation

    NASA Astrophysics Data System (ADS)

    Ryall, Rosemary L.; Cook, Alison F.; Thurgood, Lauren A.; Grover, Phulwinder K.

    2007-04-01

    Despite years of research, no single macromolecule in kidney calculi or in urine has yet been shown to fulfill a specific function in stone pathogenesis. In this paper we briefly review papers investigating the urinary excretion of individual macromolecules, their effects on calcium oxalate (CaOx) crystallization and attachment of crystals to renal epithelial cells, and the influence of lithogenic conditions on their renal expression in cultured cells and animal models. Using prothrombin fragment 1 (PTF1) and human serum albumin as examples, we show the types of patterns resulting from the binding of a fluorescently tagged protein to a specific CaOx monohydrate (COM) crystal face and its incorporation into the crystal structure. Molecular modeling is also used to illustrate how PTF1 can align with the atomic array on a COM crystal surface. We conclude that although many macromolecules are, by strict definition, relevant to stone formation, very few are probably truly influential.

  14. Formation of helical ion chains

    E-print Network

    Ramil Nigmatullin; Adolfo del Campo; Gabriele De Chiara; Giovanna Morigi; Martin B. Plenio; Alex Retzker

    2015-08-25

    We study the nonequilibrium dynamics of the linear to zigzag structural phase transition exhibited by an ion chain confined in a trap with periodic boundary conditions. The transition is driven by reducing the transverse confinement at a finite quench rate, which can be accurately controlled. This results in the formation of zigzag domains oriented along different transverse planes. The twists between different domains can be stabilized by the topology of the trap and under laser cooling the system has a chance to relax to a helical chain with nonzero winding number. Molecular dynamics simulations are used to obtain a large sample of possible trajectories for different quench rates. The scaling of the average winding number with different quench rates is compared to the prediction of the Kibble-Zurek theory, and a good quantitative agreement is found.

  15. Chaos in Terrestrial Planet Formation

    E-print Network

    Hoffmann, Volker; Moore, Ben; Stadel, Joachim

    2015-01-01

    Terrestrial planets are thought to be the result of a vast number of gravitational interactions and collisions between smaller bodies. We use numerical simulations to show that practically identical initial conditions result in a wide array of final planetary configurations. This highly chaotic behaviour questions the predictability of different scenarios for the formation and evolution of our solar system and planetary systems in general. However, multiple realisations of the same initial conditions can be used to predict certain global statistics. We present two sets of numerical experiments that quantify this behaviour. Firstly, we demonstrate that simulations with slightly displaced particles are completely divergent after ~500 years, irrespective of initial displacement, particle number, and code accuracy. If a single planetesimal is moved by less than one millimetre, then a different set of planets results -- this timescale for chaotic divergence decreases with increasing particle number. Secondly, we s...

  16. Mean depths of line formation

    NASA Astrophysics Data System (ADS)

    Gussmann, E. A.

    A straightforward reasonable physical definition of a mean depth is effected by means of the expectation value used in mathematical statistics. The real atmosphere is replaced by a fixed layer situated at the mean depth of line formation from which the observed intensity or flux emerges. Applied to the emergent line depression it is not possible to define a fixed depth but a thickness of an absorbing layer forming the absorption line. These two values have a different physical meaning and must not be confused with one another. The mean depth is calculated approximately by taking the arithmetic mean of the depths weighted with the absorption along the path outwards. This immediately leads to the well known Eddington/Barbier method.

  17. Formation and support of prominence

    NASA Technical Reports Server (NTRS)

    Forbes, T. G.

    1986-01-01

    A short introduction is given to the concepts discussed by the group on the formation and support of prominences. Only quiescent and long-lived active region prominences were considered, since transient prominence phenomena, such as sprays, surges, H alpha flare-loops, and coronal rain, are dynamically distinct from long-lived, prominences. Stable prominences (which are often referred to as filaments when seen against the disk) can be subdivided into three categories, namely active region prominences, quiescent prominences and polar crown prominences. The third category is closely related to the second since a quiescent prominence will eventually evolve into a polar crown prominence if it lasts long enough. The distinction between the first and second categories is not sharp either since intermediates exist here as well (Martin, 1973).

  18. Groundwater formation of martian valleys

    USGS Publications Warehouse

    Malin, M.C.; Carr, M.H.

    1999-01-01

    The martian surface shows large outflow channels, widely accepted as having been formed by gigantic floods that could have occurred under climatic conditions like those seen today. Also present are branching valley networks that commonly have tributaries. These valleys are much smaller than the outflow channels and their origins and ages have been controversial. For example, they might have formed through slow erosion by water running across the surface, either early or late in Mars' history, possibly protected from harsh conditions by ice cover. Alternatively, they might have formed through groundwater or ground-ice processes that undermine the surface and cause collapse, again either early or late in Mars' history. Long-duration surface runoff would imply climatic conditions quite different from the present environment. Here we present high-resolution images of martian valleys that support the view that ground water played an important role in their formation, although we are unable as yet to establish when this occurred.

  19. The Science of Galaxy Formation

    NASA Astrophysics Data System (ADS)

    Gilmore, Gerard

    2009-03-01

    Our knowledge of the Universe remains discovery-led: in the absence of adequate physics-based theory, interpretation of new results requires a scientific methodology. Commonly, scientific progress in astrophysics is motivated by the empirical success of the “Copernican Principle”, that the simplest and most objective analysis of observation leads to progress. A complementary approach tests the prediction of models against observation. In practise, astrophysics has few real theories, and has little control over what we can observe. Compromise is unavoidable. Advances in understanding complex non-linear situations, such as galaxy formation, require that models attempt to isolate key physical properties, rather than trying to reproduce complexity. A specific example is discussed, where substantial progress in fundamental physics could be made with an ambitious approach to modelling: simulating the spectrum of perturbations on small scales.

  20. Supercoil formation in DNA denaturation

    E-print Network

    A. Kabakcioglu; E. Orlandini; D. Mukamel

    2009-06-04

    We generalize the Poland-Scheraga (PS) model to the case of a circular DNA, taking into account the twisting of the two strains around each other. Guided by recent single-molecule experiments on DNA strands, we assume that the torsional stress induced by denaturation enforces formation of supercoils whose writhe absorbs the linking number expelled by the loops. Our model predicts that, when the entropy parameter of a loop satisfies $c \\le 2$, denaturation transition does not take place. On the other hand for $c>2$ a first-order denaturation transition is consistent with our model and may take place in the actual system, as in the case with no supercoils. These results are in contrast with other treatments of circular DNA melting where denaturation is assumed to be accompanied by an increase in twist rather than writhe on the bound segments.

  1. Statoconia formation in molluscan statocysts

    NASA Technical Reports Server (NTRS)

    Wiederhold, M. L.; Sheridan, C. E.; Smith, N. K.

    1986-01-01

    The gravity sensors of all molluscs phylogenetically below the cephalopods are spherical organs called statocysts. The wall of the sphere contains mechanosensory cells whose sensory cilia project into the lumen of the cyst. The lumen is filled with fluid and dense "stones", the statoconia or statoliths, which sink under the influence of gravity to load, and stimulate, those receptor cells which are at the bottom. The statoconia of Aplysia californica are shown to be calcified about a lamellar arrangement of membranes. Similar lamellar membrane arrangements are seen within the receptor cells, and their possible role in the formation of the statoconia is discussed. SEM of unfixed statoconia reveals plate-like crystallization on their surface. Elemental analysis shows a relatively high Sr content, which is of interest, since others have recently reported that Sr is required in the culture medium of several laboratory reared molluscs in order for the statoconia to develop.

  2. Union formation in fragile families.

    PubMed

    Carlson, Marcia; McLanahan, Sara; England, Paula

    2004-05-01

    In this article, we use data from a new longitudinal survey--the Fragile Families and Child Wellbeing Study--to examine union formation among unmarried parents who have just had a child together. We used multinomial logistic regression to estimate the effects of economic, cultural/interpersonal, and other factors on whether (relative to having no romantic relationship) parents are romantically involved and living apart, cohabiting, or married to each other about one year after the child's birth. Net of other factors (including baseline relationship status), women's education and men's earnings encourage marriage. Cultural and interpersonal factors also have strong effects: women's trust of men, both parents' positive attitudes toward marriage, and both parents' assessment of the supportiveness in their relationship encourage marriage. Supportiveness also encourages cohabitation, while fathers having a problem with alcohol or drugs and reporting higher conflict in the relationship discourage cohabitation: Fathers' physical violence deters couples' remaining in romantic nonresident relationships. PMID:15209039

  3. Crystal formation in furunculosis agar

    USGS Publications Warehouse

    Bullock, G.L.; Ross, A.J.

    1964-01-01

    SINCE ITS INTRODUCTION SOME MONTHS AGO, FURUNCULOSIS AGAR has been employed in the diagnosis of suspect furunculosis and also as a general purpose medium. During our work with this medium we have noticed discrete "colonies," of crystalline material, which very closely resemble microbial colonies. These crystal colonies are compact and appear on both the surface and subsurface; they occur in inoculated slants and plates incubated for long periods (2 to 3 weeks), as well as in uninoculated stored medium. As the crystal colonies could be confusing to workers using this medium, we decided to attempt to identify them and also to determine whether storage conditions and different lots of medium affect crystal formation.

  4. Multimap formation in visual cortex

    PubMed Central

    Jain, Rishabh; Millin, Rachel; Mel, Bartlett W.

    2015-01-01

    An extrastriate visual area such as V2 or V4 contains neurons selective for a multitude of complex shapes, all sharing a common topographic organization. Simultaneously developing multiple interdigitated maps—hereafter a “multimap”—is challenging in that neurons must compete to generate a diversity of response types locally, while cooperating with their dispersed same-type neighbors to achieve uniform visual field coverage for their response type at all orientations, scales, etc. Previously proposed map development schemes have relied on smooth spatial interaction functions to establish both topography and columnar organization, but by locally homogenizing cells' response properties, local smoothing mechanisms effectively rule out multimap formation. We found in computer simulations that the key requirements for multimap development are that neurons are enabled for plasticity only within highly active regions of cortex designated “learning eligibility regions” (LERs), but within an LER, each cell's learning rate is determined only by its activity level with no dependence on location. We show that a hybrid developmental rule that combines spatial and activity-dependent learning criteria in this way successfully produces multimaps when the input stream contains multiple distinct feature types, or in the degenerate case of a single feature type, produces a V1-like map with “salt-and-pepper” structure. Our results support the hypothesis that cortical maps containing a fine mixture of different response types, whether in monkey extrastriate cortex, mouse V1 or elsewhere in the cortex, rather than signaling a breakdown of map formation mechanisms at the fine scale, are a product of a generic cortical developmental scheme designed to map cells with a diversity of response properties across a shared topographic space. PMID:26641946

  5. Multimap formation in visual cortex.

    PubMed

    Jain, Rishabh; Millin, Rachel; Mel, Bartlett W

    2015-12-01

    An extrastriate visual area such as V2 or V4 contains neurons selective for a multitude of complex shapes, all sharing a common topographic organization. Simultaneously developing multiple interdigitated maps-hereafter a "multimap"-is challenging in that neurons must compete to generate a diversity of response types locally, while cooperating with their dispersed same-type neighbors to achieve uniform visual field coverage for their response type at all orientations, scales, etc. Previously proposed map development schemes have relied on smooth spatial interaction functions to establish both topography and columnar organization, but by locally homogenizing cells' response properties, local smoothing mechanisms effectively rule out multimap formation. We found in computer simulations that the key requirements for multimap development are that neurons are enabled for plasticity only within highly active regions of cortex designated "learning eligibility regions" (LERs), but within an LER, each cell's learning rate is determined only by its activity level with no dependence on location. We show that a hybrid developmental rule that combines spatial and activity-dependent learning criteria in this way successfully produces multimaps when the input stream contains multiple distinct feature types, or in the degenerate case of a single feature type, produces a V1-like map with "salt-and-pepper" structure. Our results support the hypothesis that cortical maps containing a fine mixture of different response types, whether in monkey extrastriate cortex, mouse V1 or elsewhere in the cortex, rather than signaling a breakdown of map formation mechanisms at the fine scale, are a product of a generic cortical developmental scheme designed to map cells with a diversity of response properties across a shared topographic space. PMID:26641946

  6. Methanol Masers and Star Formation

    E-print Network

    A. M. Sobolev; A. B. Ostrovskii; M. S. Kirsanova; O. V. Shelemei; M. A. Voronkov; A. V. Malyshev

    2006-01-12

    Methanol masers which are traditionally divided into two classes provide possibility to study important parts of the star forming regions: Class~II masers trace vicinities of the massive YSOs while class~I masers are likely to trace more distant parts of the outflows where newer stars can form. There are many methanol transitions which produce observed masers. This allows to use pumping analysis for estimation of the physical parameters in the maser formation regions and its environment, for the study of their evolution. Extensive surveys in different masing transitions allow to conclude on the values of the temperatures, densities, dust properties, etc. in the bulk of masing regions. Variability of the brightest masers is monitored during several years. In some cases it is probably caused by the changes of the dust temperature which follow variations in the brightness of the central YSO reflecting the character of the accretion process. A unified catalogue of the class II methanol masers consisting of more than 500 objects is compiled. Analysis of the data shows that: physical conditions within the usual maser source vary considerably; maser brightness is determined by parameters of some distinguished part of the object - maser formation region; class II methanol masers are formed not within the outflows but in the regions affected by their propagation. It is shown that the "near" solutions for the kinematic distances to the sources can be used for statistical analysis. The luminosity function of the 6.7 GHz methanol masers is constructed. It is shown that improvement of the sensitivity of surveys can increase number of detected maser sources considerably.

  7. Microfoam formation in a capillary.

    PubMed

    Kotopoulis, Spiros; Postema, Michiel

    2010-02-01

    The ultrasound-induced formation of bubble clusters may be of interest as a therapeutic means. If the clusters behave as one entity, i.e., one mega-bubble, its ultrasonic manipulation towards a boundary is straightforward and quick. If the clusters can be forced to accumulate to a microfoam, entire vessels might be blocked on purpose using an ultrasound contrast agent and a sound source. In this paper, we analyse how ultrasound contrast agent clusters are formed in a capillary and what happens to the clusters if sonication is continued, using continuous driving frequencies in the range 1-10 MHz. Furthermore, we show high-speed camera footage of microbubble clustering phenomena. We observed the following stages of microfoam formation within a dense population of microbubbles before ultrasound arrival. After the sonication started, contrast microbubbles collided, forming small clusters, owing to secondary radiation forces. These clusters coalesced within the space of a quarter of the ultrasonic wavelength, owing to primary radiation forces. The resulting microfoams translated in the direction of the ultrasound field, hitting the capillary wall, also owing to primary radiation forces. We have demonstrated that as soon as the bubble clusters are formed and as long as they are in the sound field, they behave as one entity. At our acoustic settings, it takes seconds to force the bubble clusters to positions approximately a quarter wavelength apart. It also just takes seconds to drive the clusters towards the capillary wall. Subjecting an ultrasound contrast agent of given concentration to a continuous low-amplitude signal makes it cluster to a microfoam of known position and known size, allowing for sonic manipulation. PMID:19875143

  8. Engram formation in psychiatric disorders

    PubMed Central

    Gebicke-Haerter, Peter J.

    2014-01-01

    Environmental factors substantially influence beginning and progression of mental illness, reinforcing or reducing the consequences of genetic vulnerability. Often initiated by early traumatic events, “engrams” or memories are formed that may give rise to a slow and subtle progression of psychiatric disorders. The large delay between beginning and time of onset (diagnosis) may be explained by efficient compensatory mechanisms observed in brain metabolism that use optional pathways in highly redundant molecular interactions. To this end, research has to deal with mechanisms of learning and long-term memory formation, which involves (a) epigenetic changes, (b) altered neuronal activities, and (c) changes in neuron-glia communication. On the epigenetic level, apparently DNA-methylations are more stable than histone modifications, although both closely interact. Neuronal activities basically deliver digital information, which clearly can serve as basis for memory formation (LTP). However, research in this respect has long time neglected the importance of glia. They are more actively involved in the control of neuronal activities than thought before. They can both reinforce and inhibit neuronal activities by transducing neuronal information from frequency-encoded to amplitude and frequency-modulated calcium wave patterns spreading in the glial syncytium by use of gap junctions. In this way, they serve integrative functions. In conclusion, we are dealing with two concepts of encoding information that mutually control each other and synergize: a digital (neuronal) and a wave-like (glial) computing, forming neuron-glia functional units with inbuilt feedback loops to maintain balance of excitation and inhibition. To better understand mental illness, we have to gain more insight into the dynamics of adverse environmental impact on those cellular and molecular systems. This report summarizes existing knowledge and draws some outline about further research in molecular psychiatry. PMID:24904262

  9. Drill cuttings mount formation study

    NASA Astrophysics Data System (ADS)

    Teh, Su Yean; Koh, Hock Lye

    2014-07-01

    Oil, Gas and Energy sector has been identified as an essential driving force in the Malaysian Economic Transformation Programs (ETP). Recently confirmed discovery of many offshore oil and gas deposits in Malaysian waters has ignited new confidence in this sector. However, this has also spurred intense interest on safeguarding the health and environment of coastal waters in Malaysia from adverse impact resulting from offshore oil and gas production operation. Offshore discharge of spent drilling mud and rock cuttings is the least expensive and simplest option to dispose of large volumes of drilling wastes. But this onsite offshore disposal may have adverse environmental impacts on the water column and the seabed. It may also pose occupational health hazards to the workers living in the offshore platforms. It is therefore important to model the transport and deposition of drilling mud and rock cuttings in the sea to enable proper assessment of their adverse impacts on the environment and the workers. Further, accumulation of drill particles on the seabed may impede proper operation of pipelines on the seabed. In this paper, we present an in-house application model TUNA-PT developed to cater to local oil and gas industry needs to simulate the dispersion and mount formation of drill cuttings by offshore oil and gas exploration and production platforms. Using available data on Malaysian coastal waters, simulation analyses project a pile formation on the seabed with a maximum height of about 1 m and pile radius of around 30 to 50 m. Simulated pile heights are not sensitive to the heights of release of the cuttings as the sensitivity has been mitigated by the depth of water.

  10. Formation temperatures of thermogenic and biogenic methane

    USGS Publications Warehouse

    Stolper, D.A.; Lawson, M.; Davis, C.L.; Ferreira, A.A.; Santos Neto, E. V.; Ellis, G.S.; Lewan, M.D.; Martini, A.M.; Tang, Y.; Schoell, M.; Sessions, A.L.; Eiler, J.M.

    2014-01-01

    Methane is an important greenhouse gas and energy resource generated dominantly by methanogens at low temperatures and through the breakdown of organic molecules at high temperatures. However, methane-formation temperatures in nature are often poorly constrained. We measured formation temperatures of thermogenic and biogenic methane using a “clumped isotope” technique. Thermogenic gases yield formation temperatures between 157° and 221°C, within the nominal gas window, and biogenic gases yield formation temperatures consistent with their comparatively lower-temperature formational environments (<50°C). In systems where gases have migrated and other proxies for gas-generation temperature yield ambiguous results, methane clumped-isotope temperatures distinguish among and allow for independent tests of possible gas-formation models.

  11. Giant Planet Formation, Evolution, and Internal Structure

    E-print Network

    Helled, Ravit; Podolak, Morris; Boley, Aaron; Meru, Farzana; Nayakshin, Sergei; Fortney, Jonathan J; Mayer, Lucio; Alibert, Yann; Boss, Alan P

    2013-01-01

    The large number of detected giant exoplanets offers the opportunity to improve our understanding of the formation mechanism, evolution, and interior structure of gas giant planets. The two main models for giant planet formation are core accretion and disk instability. There are substantial differences between these formation models, including formation timescale, favorable formation location, ideal disk properties for planetary formation, early evolution, planetary composition, etc. First, we summarize the two models including their substantial differences, advantages, and disadvantages, and suggest how theoretical models should be connected to available (and future) data. We next summarize current knowledge of the internal structures of solar- and extrasolar- giant planets. Finally, we suggest the next steps to be taken in giant planet exploration.

  12. Autonomous Formations of Multi-Agent Systems

    NASA Technical Reports Server (NTRS)

    Dhali, Sanjana; Joshi, Suresh M.

    2013-01-01

    Autonomous formation control of multi-agent dynamic systems has a number of applications that include ground-based and aerial robots and satellite formations. For air vehicles, formation flight ("flocking") has the potential to significantly increase airspace utilization as well as fuel efficiency. This presentation addresses two main problems in multi-agent formations: optimal role assignment to minimize the total cost (e.g., combined distance traveled by all agents); and maintaining formation geometry during flock motion. The Kuhn-Munkres ("Hungarian") algorithm is used for optimal assignment, and consensus-based leader-follower type control architecture is used to maintain formation shape despite the leader s independent movements. The methods are demonstrated by animated simulations.

  13. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium formate. 186.1756 Section 186.1756 Food and... Substances Affirmed as GRAS § 186.1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with...

  14. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium formate. 186.1756 Section 186.1756 Food and... Substances Affirmed as GRAS § 186.1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with...

  15. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium formate. 186.1756 Section 186.1756 Food and... Substances Affirmed as GRAS § 186.1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with...

  16. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium formate. 186.1756 Section 186.1756 Food and... Substances Affirmed as GRAS § 186.1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with...

  17. Floating insulated conductors for heating subsurface formations

    SciTech Connect

    Burns, David; Goodwin, Charles R.

    2014-07-29

    A heating system for a subsurface formation includes a conduit located in a first opening in the subsurface formation. Three electrical conductors are located in the conduit. A return conductor is located inside the conduit. The return conductor is electrically coupled to the ends of the electrical conductors distal from the surface of the formation. Insulation is located inside the conduit. The insulation electrically insulates the three electrical conductors, the return conductor, and the conduit from each other.

  18. Navigation and control of large satellite formations

    NASA Astrophysics Data System (ADS)

    Bamford, William Alfred, Jr.

    In recent years, there has been substantial interest in autonomous satellite formations, driven by the new technologies that enable smaller and cheaper spacecraft. Formation flying allows for mission designs, such as stereoscopic imaging, that are impractical or impossible for a single satellite. Much of the current work focuses upon small formations, which can be defined as four or less satellites in a relatively tight grouping. Next generation formations may be composed of more satellites spanning greater spatial distances. The large formation problem becomes more difficult for several reasons, including an increased amount of communication required between the satellites, and orbit perturbations, which become more important as the formation size grows. The purpose of this dissertation is to examine formation flying for large formations, and determine whether or not generalizations can be made linking the large and small formation regimes. In order to model formations with many satellites, a simulation environment was constructed in which different observers, controllers, and formation architectures can be modelled. This dissertation focuses on a decentralized control scheme, but the software is general enough to accommodate a variety of control architectures. Validation of the large formation models is accomplished by initially modelling only a pair of satellites and comparing the results against those found in the literature. As a demonstration of the theoretical results, a real-time, closed-loop, hardware-in-the-loop simulation was constructed using GPS receivers as the measurement source. A large constellation, real-tune simulation system was developed that utilized the Internet to connect simulation equipment from research centers in different locations.

  19. Magnetic Assisted Colloidal Pattern Formation

    NASA Astrophysics Data System (ADS)

    Yang, Ye

    Pattern formation is a mysterious phenomenon occurring at all scales in nature. The beauty of the resulting structures and myriad of resulting properties occurring in naturally forming patterns have attracted great interest from scientists and engineers. One of the most convenient experimental models for studying pattern formation are colloidal particle suspensions, which can be used both to explore condensed matter phenomena and as a powerful fabrication technique for forming advanced materials. In my thesis, I have focused on the study of colloidal patterns, which can be conveniently tracked in an optical microscope yet can also be thermally equilibrated on experimentally relevant time scales, allowing for ground states and transitions between them to be studied with optical tracking algorithms. In particular, I have focused on systems that spontaneously organize due to particle-surface and particle-particle interactions, paying close attention to systems that can be dynamically adjusted with an externally applied magnetic or acoustic field. In the early stages of my doctoral studies, I developed a magnetic field manipulation technique to quantify the adhesion force between particles and surfaces. This manipulation technique is based on the magnetic dipolar interactions between colloidal particles and their "image dipoles" that appear within planar substrate. Since the particles interact with their own images, this system enables massively parallel surface force measurements (>100 measurements) in a single experiment, and allows statistical properties of particle-surface adhesion energies to be extracted as a function of loading rate. With this approach, I was able to probe sub-picoNewton surface interactions between colloidal particles and several substrates at the lowest force loading rates ever achieved. In the later stages of my doctoral studies, I focused on studying patterns formed from particle-particle interaction, which serve as an experimental model of phase transitions in condensed matter systems that can be tracked with single particle resolution. Compared with other research on colloidal crystal formation, my research has focused on multi-component colloidal systems of magnetic and non-magnetic colloids immersed in a ferrofluid. Initially, I studied the types of patterns that form as a function of the concentrations of the different particles and ferrofluid, and I discovered a wide variety of chains, rings and crystals forming in bi-component and tri-component systems. Based on these results, I narrowed my focus to one specific crystal structure (checkerboard lattice) as a model of phase transformations in alloy. Liquid/solid phase transitions were studied by slowly adjusting the magnetic field strength, which serves to control particle-particle interactions in a manner similar to controlling the physical temperature of the fluid. These studies were used to determine the optimal conditions for forming large single crystal structures, and paved the way for my later work on solid/solid phase transitions when the angle of the external field was shifted away from the normal direction. The magnetostriction coefficient of these crystals was measured in low tilt angle of the applied field. At high tilt angles, I observed a variety of martensitic transformations, which followed different pathways depending on the crystal direction relative to the in-plane field. In the last part of my doctoral studies, I investigated colloidal patterns formed in a superimposed acoustic and magnetic field. In this approach, the magnetic field mimics "temperature", while the acoustic field mimics "pressure". The ability to simultaneously tune both temperature and pressure allows for more efficient exploration of phase space. With this technique I demonstrated a large class of particle structures ranging from discrete molecule-like clusters to well ordered crystal phases. Additionally, I demonstrated a crosslinking strategy based on photoacids, which stabilized the structures after the external field

  20. Heating tar sands formations to visbreaking temperatures

    DOEpatents

    Karanikas, John Michael (Houston, TX); Colmenares, Tulio Rafael (Houston, TX); Zhang, Etuan (Houston, TX); Marino, Marian (Houston, TX); Roes, Augustinus Wilhelmus Maria (Houston, TX); Ryan, Robert Charles (Houston, TX); Beer, Gary Lee (Houston, TX); Dombrowski, Robert James (Houston, TX); Jaiswal, Namit (Houston, TX)

    2009-12-22

    Methods for treating a tar sands formation are described herein. Methods may include heating at least a section of a hydrocarbon layer in the formation from a plurality of heaters located in the formation. The heat may be controlled so that at least a majority of the section reaches an average temperature of between 200.degree. C. and 240.degree. C., which results in visbreaking of at least some hydrocarbons in the section. At least some visbroken hydrocarbon fluids may be produced from the formation.

  1. Heating systems for heating subsurface formations

    DOEpatents

    Nguyen, Scott Vinh (Houston, TX); Vinegar, Harold J. (Bellaire, TX)

    2011-04-26

    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  2. The formation of ice on airplanes

    NASA Technical Reports Server (NTRS)

    Noth, H; Polte, W

    1936-01-01

    The present report examines the problem of ice formation from the point of view of the pilot and the meteorologist. Their experiences prove the ice deposit to be first and foremost a navigational problem and only secondarily a question of de-icing devices. With correct utilization of the meteorological information by the flyer, ice hazard can in many cases be minimized or avoided. Ice formation and the different types of ice deposits are listed and discussed. Weather formation during these ice deposits are also discussed as well as the effect of ice formation on aircraft.

  3. New Particle Formation Study Final Campaign Report

    SciTech Connect

    Smith, JN; McMurry, PH

    2015-01-01

    The scientific foci of the New Particle Formation Study were the formation and evolution of atmospheric aerosols and the impacts of newly formed particles on cloud processes. Specifically, we planned to: (1) to identify the species and mechanisms responsible for the initial steps of new particle formation, i.e., the formation of thermodynamically stable clusters; (2) investigate the role of acid-base chemistry in new particle growth through measurements of ammonia and amines as well as organic and inorganic acids in both atmospheric nanoparticles and the gas phase; (3) investigate the contribution of other surface area or volume-controlled processes to nanoparticle formation and growth; (4) create a comprehensive dataset related to new particle formation and growth that can be used as input for our own thermodynamic models as well as the modeling efforts by our Department of Energy (DOE) Aerosol Life Cycle working group collaborators; (5) characterize the increase of the number and activity of cloud condensation nuclei (CCN) due to particle formation and growth; (6) determine the regional extent of new particle formation to address the role that atmospheric transport plays in determining the impacts, if any, of new particle formation on cloud number and properties.

  4. Duration of the earth-formation interval

    NASA Astrophysics Data System (ADS)

    Levskii, L. K.

    The duration of the formation interval of prototerrestrial matter is estimated on the basis of the iodine-xenon and plutonium-xenon dating techniques. The formation interval is shown to include two phases: (1) a galactic (nebular) phase corresponding to the independent existence of two sources and lasting 150 million years; and (2) a planetesimal (accretion) phase lasting not more than 140 million years. The total duration of the formation interval from the termination of nucleosynthesis to the formation of the planet amounts to not more than 300-400 million years.

  5. Processes and problems in secondary star formation

    SciTech Connect

    Klein, R.I.; Whitaker, R.W.; Sandford M.T. II

    1984-03-01

    Recent developments relating the conditions in molecular clouds to star formation triggered by a prior stellar generation are reviewed. Primary processes are those that lead to the formation of a first stellar generation. The secondary processes that produce stars in response to effects caused by existing stars are compared and evaluated in terms of the observational data presently available. We discuss the role of turbulence to produce clumpy cloud structures and introduce new work on colliding inter-cloud gas flows leading to non-linear inhomogeneous cloud structures in an intially smooth cloud. This clumpy morphology has important consequences for secondary formation. The triggering processes of supernovae, stellar winds, and H II regions are discussed with emphasis on the consequences for radiation driven implosion as a promising secondary star formation mechanism. Detailed two-dimensional, radiation-hydrodynamic calculations of radiation driven implosion are discussed. This mechanism is shown to be highly efficient in synchronizing the formation of new stars in congruent to 1-3 x 10/sup 4/ years and could account for the recent evidence for new massive star formation in several UCHII regions. It is concluded that, while no single theory adequately explains the variety of star formation observed, a uniform description of star formation is likely to involve several secondary processes. Advances in the theory of star formation will require multiple dimensional calculations of coupled processes. The important non-linear interactions include hydrodynamics, radiation transport, and magnetic fields.

  6. On the Formation of Brown Dwarfs

    E-print Network

    Ing-Guey Jiang; G. Laughlin; D. N. C. Lin

    2003-09-19

    The observational properties of brown dwarfs pose challenges to the theory of star formation. Because their mass is much smaller than the typical Jeans mass of interstellar clouds, brown dwarfs are most likely formed through secondary fragmentation processes, rather than through the direct collapse of a molecular cloud core. In order to prevent substantial post-formation mass accretion, young brown dwarfs must leave the high density formation regions in which they form. We propose here that brown dwarfs are formed in the circumbinary disks. Through post-formation dynamical interaction with their host binary stars, young brown dwarfs are either scattered to large distance or removed, with modest speed, from their cradles.

  7. Star formation in very young galactic clusters

    SciTech Connect

    Schroeder, M.C.; Comins, N.F.

    1988-03-01

    It is argued, following Stahler (1985), that in young galactic clusters both the suggested exponential increase in star-formation rates with time and the mass-age correlation are artifacts of incorrectly assigning pre-main-sequence ages to main-sequence stars. Quantitative arguments are presented for simultaneous formation of stars with different masses (contemporaneous star formation) in such clusters and a method is presented for determining star-formation histories and the ages of young galactic clusters (i.e., clusters in which pre-main-sequence stars are detectable). 25 references.

  8. Treating tar sands formations with dolomite

    DOEpatents

    Vinegar, Harold J.; Karanikas, John Michael

    2013-10-15

    A method for treating a karsted formation containing heavy hydrocarbons and dolomite includes providing heat to at least part of one or more karsted layers in the formation from one or more heaters located in the karsted layers. A temperature in at least one of the karsted layers is allowed to reach a decomposition temperature of dolomite in the formation. The dolomite is allowed to decompose and at least some hydrocarbons are produced from at least one of the karsted layers of the formation.

  9. Format requirements of thermal neutron scattering data in a nuclear data format to succeed the ENDF format

    SciTech Connect

    Brown, D.

    2014-03-31

    In November 2012, the Working Party on Evaluation Cooperation Subgroup 38 (WPEC-SG38) began with the task of developing a nuclear data format and supporting infrastructure to replace the now nearly 50 year old ENDF format. The first step in this process is to develop requirements for the new format and infrastructure. In this talk, I will review the status of ENDF's Thermal Scattering Law (TSL) formats as well as support for this data in the GND format (from which the new format is expected to evolve). Finally, I hope to begin a dialog with members of the thermal neutron scattering community so that their data needs can be accurately and easily accommodated by the new format and tools, as captured by the requirements document. During this discussion, we must keep in mind that the new tools and format must; Support what is in existing data files; Support new things we want to put in data files; and Be flexible enough for us to adapt it to future unanticipated challenges.

  10. Spheromak formation studies in SSPX

    SciTech Connect

    Hill, D N; Bulmer, R H; Cohen, B L; Hooper, E B; LoDestro, L L; Mattor, N; McLean, H S; Moller, J; Pearlstein, L D; Ryutov, D D; Stallard, B W; Wood, R D; Woodruff, S; Holcomb, C T; Jarboe, T; Sovinec, C R; Wang, Z; Wurden, G

    2000-09-29

    We present results from the Sustained Spheromak Physics Experiment (SSPX) at LLNL, which has been built to study energy confinement in spheromak plasmas sustained for up to 2 ms by coaxial DC helicity injection. Peak toroidal currents as high as 600kA have been obtained in the 1m dia. (0.23m minor radius) device using injection currents between 200-400kA; these currents generate edge poloidal fields in the range of 0.2-0.4T. The internal field and current profiles are inferred from edge field measurements using the CORSICA code. Density and impurity control is obtained using baking, glow discharge cleansing, and titanium gettering, after which long plasma decay times ({tau} {ge} 1.5ms) are observed and impurity radiation losses are reduced from {approx}50% to <20% of the input energy. Thomson scattering measurements show peaked electron temperature and pressure profiles with T{sub e} (0){approx}120eV and {beta}{sub e}{approx}7%. Edge field measurements show the presence of n=1 modes during the formation phase, as has been observed in other spheromaks. This mode dies away during sustainment and decay so that edge fluctuation levels as low as 1% have been measured. These results are compared with numerical simulations using the NIMROD code.

  11. Cosmic vacuum and galaxy formation

    NASA Astrophysics Data System (ADS)

    Chernin, A. D.

    2006-04-01

    It is demonstrated that the protogalactic perturbations must enter the nonlinear regime before the red shift z? 1; otherwise they would be destroyed by the antigravity of the vacuum dark energy at the subsequent epoch of the vacuum domination. At the zrrV={M/[(8?/3)?V]}1/3, where M is the mass of a given over-density and ?V is the vacuum density. The criterion provides a new relation between the largest mass condensations and their spatial scales. All the real large-scale systems follow this relation definitely. It is also shown that a simple formula is possible for the key quantity in the theory of galaxy formation, namely the initial amplitude of the perturbation of the gravitational potential in the protogalactic structures. The amplitude is time independent and given in terms of the Friedmann integrals, which are genuine physical characteristics of the cosmic energies. The results suggest that there is a strong correspondence between the global design of the Universe as a whole and the cosmic structures of various masses and spatial scales.

  12. Chaos in Terrestrial Planet Formation

    E-print Network

    Volker Hoffmann; Simon L. Grimm; Ben Moore; Joachim Stadel

    2015-08-04

    Terrestrial planets are thought to be the result of a vast number of gravitational interactions and collisions between smaller bodies. We use numerical simulations to show that practically identical initial conditions result in a wide array of final planetary configurations. This highly chaotic behaviour questions the predictability of different scenarios for the formation and evolution of our solar system and planetary systems in general. However, multiple realisations of the same initial conditions can be used to predict certain global statistics. We present two sets of numerical experiments that quantify this behaviour. Firstly, we demonstrate that simulations with slightly displaced particles are completely divergent after ~500 years, irrespective of initial displacement, particle number, and code accuracy. If a single planetesimal is moved by less than one millimetre, then a different set of planets results -- this timescale for chaotic divergence decreases with increasing particle number. Secondly, we show final planetary configurations of initially similar simulations with and without giant planets after evolving them for ~148 Myr. We find that the same simulations including giant planets tend to generate higher mass planets at lower semi-major axes than simulations without gas giants. This prediction can be tested with forthcoming observational programs. By extracting outliers in the observations, we cautiously predict that Kepler-10, Kepler-9, 61 Vir, HD 134060, and HD 51608 may host as yet undetected giant planets.

  13. String formation beyond leading colour

    NASA Astrophysics Data System (ADS)

    Christiansen, Jesper R.; Skands, Peter Z.

    2015-08-01

    We present a new model for the hadronisation of multi-parton systems, in which colour correlations beyond leading N C are allowed to influence the formation of confining potentials (strings). The multiplet structure of SU(3) is combined with a minimisation of the string potential energy, to decide between which partons strings should form, allowing also for "baryonic" configurations (e.g., two colours can combine coherently to form an anticolour). In e + e -collisions, modifications to the leading-colour picture are small, suppressed by both colour and kinematics factors. But in pp collisions, multi-parton interactions increase the number of possible subleading connections, counteracting their naive 1/ N {/C 2} suppression. Moreover, those that reduce the overall string lengths are kinematically favoured. The model, which we have implemented in the PYTHIA 8 generator, is capable of reaching agreement not only with the important < p ?> ( n charged) distribution but also with measured rates (and ratios) of kaons and hyperons, in both ee and pp collisions. Nonetheless, the shape of their p ? spectra remains challenging to explain.

  14. Spiral Galactic Formation and Evolution

    NASA Astrophysics Data System (ADS)

    Brekke, Stewart

    2009-05-01

    Before the period of galactic formation the uiverse consisted of a vast number of pre-formed systems consisting of two or more pre-galactic arms, the arms orbiting each other. As the orbits of the arms decayed the sides of the fore-sections of the arms tangentially collided and joined and thereby forming multi-armed spiral galaxies which began to rotate.The rotation resulted from the conversion of the orbital motion of the individual arms when joined into faster rotational motion of the newly formed galaxy. The spiral arms were maintained by the centripital force of the rapidly rotational motion of the galaxy system. As the rotational motion of the galaxy slowed down the arms of the spiral galaxy collapsed towards the body of the galaxy due to lessening of centripetal force on the arms and elliptical galaxies were formed and with further lessening of galactic rotational motion galactic disks were formed. One can see in galaxies M51, M100, NGC2336 and NGC4939 the galactic arms came from external orbit, not disks or instabilities in support of this theory. Also in support of this theory of galactic evolution is that spiral galaxies rotate faster than ellipticals or disks.

  15. Formation of the solar system

    NASA Astrophysics Data System (ADS)

    Rawal, J. J.

    1986-02-01

    An alternative method for deriving the Titius-Bode law is examined. Prentice's modern Laplacian theory (1978a, b) which calculates the ratio of orbital radii of successively disposed rings as 1.69, and Rawal's (1984a) 1.442 ratio value derived from the Roche limit concept are reviewed. The interrelations between the supersonic turbulent convection, rotational instability, and Roche limit are analyzed. The equations for evaluating the total energy of a uniformly turbulent cloud of equatorial radius existing in a hydrostatic equilibrium are explained. The influence of turbulence on the cloud is investigated. The supersonic turbulence is unable to completely stabilize the cloud during the collapse from 10,000 to 300 solar radii. The turbulent stress also causes the formation of a very steep density inversion at the photosphere; the effect of turbulence on the differential motion and rotation in the cloud is studied. It is concluded that the Bode constant calculated using the proposed technique is equivalent to the Roche limit.

  16. The Magellanic System's Interactive Formations

    NASA Astrophysics Data System (ADS)

    Putman, M. E.

    2000-04-01

    The interaction between the Galaxy and the Magellanic Clouds has resulted in several high-velocity complexes which are connected to the Clouds. The complexes are known as the Magellanic Bridge, an HI connection between the Large and Small Magellanic Clouds, the Magellanic Stream, a 10° × 100° HI filament which trails the Clouds, and the Leading Arm, a diffuse HI filament which leads the Clouds. The mechanism responsible for these features formation remains under some debate, with the lack of detailed HI observations being one of the limiting factors in resolving the issue. Here I present several large mosaics of HI Parkes All-Sky Survey (HIPASS) data which show the full extent of the three Magellanic complexes at almost twice the resolution of previous observations. These interactive features are connected, but unique in their spatial and velocity distribution. The differences may shed light on their origin and present environment. Dense clumps of HI along the sightline to the Sculptor Group, which may or may not be associated with the Magellanic complexes, are also discussed.

  17. A model for fingerprint formation

    NASA Astrophysics Data System (ADS)

    Kücken, M.; Newell, A. C.

    2004-10-01

    The uniqueness of fingerprints (epidermal ridges) has been recognized for over two thousand years. They have been studied scientifically for more than two hundred years. Yet, in spite of the accumulation of a wealth of empirical and experimental knowledge, no widely accepted explanation for the development of epidermal ridges on fingers, palms and soles has yet emerged. Informed by an extensive literature study we suggest that fingerprint patterns are created as the result of a buckling instability in the basal cell layer of the fetal epidermis. Analysis of the well-known von Karman equations informs us that the buckling direction is perpendicular to the direction of greatest stress in the basal layer. We propose that this stress is induced by resistance of furrows and creases to the differential growth of the basal layer and regression of the volar pads during the time of ridge formation. These theories have been tested by computer experiments. The results are in close harmony with observations. Specifically, they are consistent with the well-known observation that the pattern type depends on the geometry of the fingertip surface when fingerprint patterns are formed.

  18. Star Formation in Tadpole Galaxies

    E-print Network

    Munoz-Tunon, Casiana; Elmegreen, Debra M; Elmegreen, Bruce G

    2014-01-01

    Tadpole Galaxies look like a star forming head with a tail structure to the side. They are also named cometaries. In a series of recent works we have discovered a number of issues that lead us to consider them extremely interesting targets. First, from images, they are disks with a lopsided starburst. This result is firmly established with long slit spectroscopy in a nearby representative sample. They rotate with the head following the rotation pattern but displaced from the rotation center. Moreover, in a search for extremely metal poor (XMP) galaxies, we identified tadpoles as the dominant shapes in the sample- nearly 80% of the local XMP galaxies have a tadpole morphology. In addition, the spatially resolved analysis of the metallicity shows the remarkable result that there is a metallicity drop right at the position of the head. This is contrary to what intuition would say and difficult to explain if star formation has happened from gas processed in the disk. The result could however be understood if the ...

  19. Dune formation under bimodal winds

    PubMed Central

    Parteli, Eric J. R.; Durán, Orencio; Tsoar, Haim; Schwämmle, Veit; Herrmann, Hans J.

    2009-01-01

    The study of dune morphology represents a valuable tool in the investigation of planetary wind systems—the primary factor controlling the dune shape is the wind directionality. However, our understanding of dune formation is still limited to the simplest situation of unidirectional winds: There is no model that solves the equations of sand transport under the most common situation of seasonally varying wind directions. Here we present the calculation of sand transport under bimodal winds using a dune model that is extended to account for more than one wind direction. Our calculations show that dunes align longitudinally to the resultant wind trend if the angle ?w between the wind directions is larger than 90°. Under high sand availability, linear seif dunes are obtained, the intriguing meandering shape of which is found to be controlled by the dune height and by the time the wind lasts at each one of the two wind directions. Unusual dune shapes including the “wedge dunes” observed on Mars appear within a wide spectrum of bimodal dune morphologies under low sand availability. PMID:20018703

  20. Pattern Formation in Excitable Media

    NASA Astrophysics Data System (ADS)

    Reynolds, William Nash

    1992-01-01

    The phenomenon of excitability is observed in a wide variety of physical and biological systems. In this work, spatially extended excitable systems are examined from several different perspectives. First, a pedagogical introduction is used to motivate the derivation of the dynamics of one dimensional excitable pulses. In the second part, coupled map techniques for numerical simulation of excitable media and other interfacial systems are described. Examples are given for both excitable media and crystal growth. The third chapter addresses the phenomenon of spiral formation in excitable media. Exact rotating solutions are found for a class of models of excitable media. The solutions consist of two regions: an outer region, consisting of the spiral proper, which exhibits a singularity at its tip, and the core region, obtained by rescaling space in the vicinity of the tip. The tip singularity is resolved in the core region, leading to a consistent solution in all of space. The stability of both the spiral and the core is investigated, with the result that the spiral is found to be stable, and the core unstable. Finally, the stability of excitable waves of the chemical cAMP traveling over aggregating colonies of the slime mold Dictyostelium discoideum is examined by coupling the excitable dynamics of the cAMP signalling system to a simple model of chemotaxis, with result that cellular motion is found to destabilize the waves, causing the initially uniform field of cells to break up into streams.