Science.gov

Sample records for reworks

  1. Reworked eolianites: Bahaman highstand anomalies

    SciTech Connect

    Ball, M.M. )

    1990-05-01

    Eolianites, presumably formed during the last sea level lowstand, rise more than 40 m above the present-day highstand. These carbonate dune are being reworked by wave action to form sediment bodies (highstand conglomerates) with settings, geometries, internal structures, compositions, and textures that may be similar to those of lowstand conglomerates. The setting of these reworked eolianites is the windward platform edge. The geometry is a belt parallel to the platform edge, that may thin both platformward and basinward. Internal structure should include some large-scale foresets with chaotic dip directions and some evidence of tilted and overturned beds. Composition consists of marine bioclastic carbonate sand in boulder to sand-size clasts. If remnants of the carbonate dunes are preserved in the geologic record, highstand conglomerates should be recognizable on the basis of their association with these eolianites. The original eolianites are confirmed to a belt on the windward margins of the carbonate platform up to 7 km wide. Their geometry consists of linear sand waves or ridges composed of spillover lobes. Internal structure predominantly includes large-scale foresets dipping toward the platform interior. Composition is indistinguishable from that of associated highstand conglomerates with the possible exception that the latter might contain some high-magnesium calcite or aragonite marine cement. Whole marine fossils are absent in the eolianites. Red-weathered zones are common on dune exposure surface. Solution brecciation and cave deposition further complicate the diagenetic history of the eolianites, their associated highstand conglomerates, and their lowstand conglomeratic facies.

  2. Reworking Seventeenth-Century Saltpetre.

    PubMed

    Robertson, Haileigh

    2016-05-01

    In the early modern period, saltpetre was perhaps best known for its role as one of the three components of gunpowder. For natural philosophers in seventeenth-century England, saltpetre also had important uses in chymistry and medicine. While some factories did successfully produce saltpetre in early modern England, the domestic industry was not on the whole a great success. Intellectuals who were keen to apply their knowledge in the real world saw this as an opportunity, and proposed a variety of new and improved methods that they claimed would produce this vital material more efficiently and in abundance. Yet their proposals remained on the page and their efforts fell flat. To understand the challenges and experiences faced by both scholars and artisan saltpetre-makers, I 'reworked' early modern methods of saltpetre-making with the Medieval Gunpowder Research Group. Reworking revealed procedural challenges and complexities that explain why, even with the best intentions, seventeenth-century natural philosophers struggled to get to grips with this important material.

  3. 7 CFR 29.2545 - Rework.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Rework. 29.2545 Section 29.2545 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing...) Tobacco which is so mixed that it cannot be classified properly in any grade of the type, because the...

  4. 7 CFR 29.2293 - Rework.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Rework. 29.2293 Section 29.2293 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing..., including: (a) Tobacco which is so mixed that it cannot be classified properly in any grade of the...

  5. 7 CFR 29.2293 - Rework.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Rework. 29.2293 Section 29.2293 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing..., including: (a) Tobacco which is so mixed that it cannot be classified properly in any grade of the...

  6. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA... mechanical, electronic, or manual procedures normally used in the handling of pistachios. After the rework... rework procedure for aflatoxin. If pistachio kernel rework is selected as a remedy to meet the...

  7. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  8. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  9. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  10. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... procedure for aflatoxin. If inshell rework is selected as a remedy to meet the aflatoxin regulations of this... product shall be reported to the committee. The reworked lot shall be sampled and tested for aflatoxin as... the lot has been reworked and tested, it fails the aflatoxin test for a second time, the lot may...

  11. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA, AND NEW MEXICO Regulations § 983.52 Failed lots/rework procedure. (a) Substandard pistachios. Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements....

  12. Welding rework data acquisition and automation

    NASA Technical Reports Server (NTRS)

    Romine, Peter L.

    1996-01-01

    Aluminum-Lithium is a modern material that NASA MSFC is evaluating as an option for the aluminum alloys and other aerospace metals presently in use. The importance of aluminum-lithium is in it's superior weight to strength characteristics. However, aluminum-lithium has produced many challenges in regards to manufacturing and maintenance. The solution to these problems are vital to the future uses of the shuttle for delivering larger payloads into earth orbit and are equally important to future commercial applications of aluminum-lithium. The Metals Processes Branch at MSFC is conducting extensive tests on aluminum-lithium which includes the collection of large amounts of data. This report discusses the automation and data acquisition for two processes: the initial weld and the repair. The new approach reduces the time required to collect the data, increases the accuracy of the data, and eliminates several types of human errors during data collection and entry. The same material properties that enhance the weight to strength characteristics of aluminum-lithium contribute to the problems with cracks occurring during welding, especially during the repair/rework process. The repairs are required to remove flaws or defects discovered in the initial weld, either discovered by x-ray, visual inspection, or some other type of nondestructive evaluation. It has been observed that cracks typically appear as a result of or beyond the second repair. MSFC scientists have determined that residual mechanical stress introduced by the welding process is a primary cause of the cracking. Two obvious solutions are to either prevent or minimize the stress introduced during the welding process, or remove or reduce the stress after the welding process and MSFC is investigating both of these.

  13. 65. BUILDING NO. 554, REWORK POWDER GRINDING HOUSE, PULVERIZING, WATER ...

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

    65. BUILDING NO. 554, REWORK POWDER GRINDING HOUSE, PULVERIZING, WATER DRY HOUSE, LOOKING SOUTH AT NORTH SIDE (DEMOLITION IN PROGRESS) OF BUILDING ONCE USED FOR REWORK POWDER GRINDING AND PULVERIZING (SEE NJ-36-C-33 FOR DIAGRAM OF THIS RECLAMATION PROCESS). THIS BUILDING ALSO SERVED AS A WATER DRY HOUSE. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  14. 164. GENERAL VIEW OF BUILDING 60 (AIR REWORK FACILITY) AND ...

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

    164. GENERAL VIEW OF BUILDING 60 (AIR REWORK FACILITY) AND ENVIRONS. ROBERT AND CO., ARCHITECT-ENGINEERS FOR BUILDING 60. DISTANT VIEW NORTH TOWARD BUILDING 60 FROM THE INTERSECTION OF QUONSET RD. AND 1ST AVE., AIRFIELD VISIBLE ON RIGHT. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  15. 225. BUILDING 60. (AIR REWORK FACILITY) 194041; ALTERED 194849. GIBBS ...

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

    225. BUILDING 60. (AIR REWORK FACILITY) 1940-41; ALTERED 1948-49. GIBBS AND HALL, ARCHITECTS (WORKING FROM PLANS BY ROBERT AND CO. FOR NAS JACKSONVILLE). GENERAL VIEW FROM WEST. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  16. 224. BUILDING 60. (AIR REWORK FACILITY) 194041; ALTERED 194849 GIBBS ...

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

    224. BUILDING 60. (AIR REWORK FACILITY) 1940-41; ALTERED 1948-49 GIBBS AND HALL, ARCHITECTS, WORKING FROM PLANS BY ROBERT AND CO. FOR NAS JACKSONVILLE; SOUTH END OF THE HANGAR WING. VIEW FROM SOUTHEAST. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  17. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  18. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  19. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  20. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Each lot of substandard pistachios may be reworked to meet aflatoxin or quality requirements. The... reporting. If a lot fails to meet the aflatoxin and/or the quality requirements of this part, a failed lot.... This form must be completed and submitted to the committee each time a lot fails either aflatoxin...

  1. Accretion and reworking beneath the North China Craton

    NASA Astrophysics Data System (ADS)

    Zheng, J. P.; Griffin, W. L.; Ma, Q.; O'Reilly, S. Y.; Xiong, Q.; Tang, H. Y.; Zhao, J. H.; Yu, C. M.; Su, Y. P.

    2012-09-01

    How has the Earth's continental lithosphere evolved? Most of our knowledge is derived from surface exposures, but xenoliths carried in volcanic rocks can be an important source of information. The North China Craton (NCC) is one of the oldest in the world and Phanerozoic volcanic rocks with abundant xenoliths are widespread, making it an ideal area to study the formation and evolution of continents. New analyses of U-Pb ages and Hf isotopes in zircon were obtained for lower crustal xenoliths from four localities including the Paleozoic Yingxian lamproites, and the basalts of Pingquan (Paleocene), Hebi and Nushan (Neogene). Published ages and compositions of lower crustal and upper mantle xenoliths from the NCC are synthesized to constrain the accretion and reworking processes that have affected the deep lithosphere beneath the craton. The peridotite bodies within the Dabie-Sulu ultrahigh-pressure (UHP) belt, along the southern edge of the NCC, are compared with the xenolith peridotites to constrain early Mesozoic dynamics. The oldest components of the NCC may be ~ 4.0 Ga old. The craton experienced complex accretion and reworking processes in its deep lithosphere, accompanied by the formation (or aggregation) and differentiation of the ancient continental nucleus. The small size of the NCC, compared with many other cratons worldwide, made it more susceptible to the effects of marginal subduction and collision with surrounding blocks. The subcontinental lithosphere mantle (SCLM) was generally coupled with the lower crust through the Paleozoic, while decoupling occurred in late Mesozoic-Cenozoic time, except locally (such as the Neoarchen lower crust and SCLM in Hebi), suggesting strong interactions between the asthenosphere and the lithosphere (both upper mantle and lower crust) in Phanerozoic time. In the lower crust, the ancient components of the craton were re-worked in Paleoarchean (3.80-3.65 Ga) time. The craton also experienced two important accretionary

  2. 30 CFR 256.70 - Extension of lease by drilling or well reworking operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Extension of lease by drilling or well..., and Extensions § 256.70 Extension of lease by drilling or well reworking operations. The term of a lease shall be extended beyond the primary term so long as drilling or well reworking operations...

  3. Physical reworking by near-bottom flow alters the metazoan meiofauna of Fieberling Guyot (northeast Pacific)

    NASA Astrophysics Data System (ADS)

    Thistle, David; Levin, Lisa A.; Gooday, Andrew J.; Pfannkuche, Olaf; Lambshead, P. John D.

    1999-12-01

    Although much of the deep sea is physically tranquil, some regions experience near-bottom flows that rework the surficial sediment. During periods of physical reworking, animals in the reworked layer risk being suspended, which can have both positive and negative effects. Reworking can also change the sediment in ecologically important ways, so the fauna of reworked sites should differ from that of quiescent locations. We combined data from two reworked, bathyal sites on the summit of Fieberling Guyot (32°27.631'N, 127°49.489'W; 32°27.581'N, 127°47.839'W) and compared the results with those of more tranquil sites. We tested for differences in the following parameters, which seemed likely to be sensitive to the direct or indirect effects of reworking: (1) the vertical distribution of the meiofauna in the sea bed, (2) the relative abundance of surface-living harpacticoids, (3) the proportion of the fauna consisting of interstitial harpacticoids, (4) the ratio of harpacticoids to nematodes. We found that the vertical distributions of harpacticoid copepods, ostracods, and kinorhynchs were deeper on Fieberling. In addition, the relative abundance of surface-living harpacticoids was less, the proportion of interstitial harpacticoids was greater, and the ratio of harpacticoids to nematodes was greater on Fieberling. These differences between Fieberling and the comparison sites suggest that physical reworking affects deep-sea meiofauna and indicate the nature of some of the effects.

  4. In situ reworking /gardening/ of the lunar surface - Evidence from the Apollo cores

    NASA Technical Reports Server (NTRS)

    Morris, R. V.

    1978-01-01

    The in situ reworking (gardening) of the lunar surface by impacting projectiles creates an in situ reworking zone extending horizontally over the entire regolith surface and extending vertically from the surface to a depth which varies from place-to-place on the moon. On the basis of available evidence, the 'high-maturity' zones observed at the top of the lunar cores have resulted from the in situ reworking of the present-day lunar surface. The temporal variation of the in situ reworking depth was investigated using depths inferred from maturity I sub s/FeO and Al-26 profiles of Apollo cores. The observed temporal variation of the in situ reworking depth in units of centimeters is equal to 2.2 times the time (in units of million years) to the 0.45th power.

  5. Rework of the ERA software system: ERA-8

    NASA Astrophysics Data System (ADS)

    Pavlov, D.; Skripnichenko, V.

    2015-08-01

    The software system that has been powering many products of the IAA during decades has undergone a major rework. ERA has capabilities for: processing tables of observations of different kinds, fitting parameters to observations, integrating equations of motion of the Solar system bodies. ERA comprises a domain-specific language called SLON, tailored for astronomical tasks. SLON provides a convenient syntax for reductions of observations, choosing of IAU standards to use, applying rules for filtering observations or selecting parameters for fitting. Also, ERA includes a table editor and a graph plotter. ERA-8 has a number of improvements over previous versions such as: integration of the Solar system and TT xA1 TDB with arbitrary number of asteroids; option to use different ephemeris (including DE and INPOP); integrator with 80-bit floating point. The code of ERA-8 has been completely rewritten from Pascal to C (for numerical computations) and Racket (for running SLON programs and managing data). ERA-8 is portable across major operating systems. The format of tables in ERA-8 is based on SQLite. The SPICE format has been chosen as the main format for ephemeris in ERA-8.

  6. East Louisiana continental shelf sediments: a product of delta reworking

    USGS Publications Warehouse

    Brooks, Gregg R.; Kingdinger, Jack L.; Penland, Shea; Williams, S. Jeffress

    1995-01-01

    Data from 77 vibracores were integrated with 6,700 line-km of high- resolution seismic reflection profiles collected off the eastern Louisiana coast in the region of the St. Bernard Delta, the first of the Holocene highstand deltas of the Mississippi River. Seismic fades and sediment facies were integrated in order to establish the stratigraphic details within this relict delta. Results provide a regional geologic framework from which comparisons can be made with other areas. Holocene deposits in the study area overlie a heavily dissected surface interpreted to represent a lowstand erosional surface. Resting on this surface is a thin unit of relatively clean, quartz sand interpreted to have been deposited during early transgression. This unit is overlain by sediments of the St. Bernard Delta, a seaward-prograding, coarsening-upward wedge of sands and muds that contain vertically-stacked units of deltaic succession. Two or more prograding units separated by an unconformity, delineated from regional seismic profiles, may represent laterally shifting subdelta lobes. Surficial sediments consist of a thin unit of sands and muds derived from and reflecting the individual subenvirons of the underlying delta. Holocene inner-shelf development off eastern Louisiana has been controlled by relative sea-level rise and sediment supply. Sediment supply and deposition are a product of delta progradation and delta-lobe switching. The modern shelf configuration and surficial sediment distribution patterns reflect reworking of underlying deltaic deposits. The lack of modern sediment input helps to maintain the imprint of this ancient delta on the modern shelf surface.

  7. Sediment reworking rates in deep sediments of the Mediterranean Sea.

    PubMed

    Barsanti, M; Delbono, I; Schirone, A; Langone, L; Miserocchi, S; Salvi, S; Delfanti, R

    2011-07-01

    Different pelagic areas of the Mediterranean Sea have been investigated in order to quantify physical and biological mixing processes in deep sea sediments. Herein, results of eleven sediment cores sampled at different deep areas (> 2000 m) of the Western and Eastern Mediterranean Sea are presented. ²¹⁰Pb(xs) and ¹³⁷Cs vertical profiles, together with ¹⁴C dating, are used to identify the main processes characterising the different areas and, finally, controlling mixing depths (SML) and bioturbation coefficients (D(b)). Radionuclide vertical profiles and inventories indicate that bioturbation processes are the dominant processes responsible for sediment reworking in deep sea environments. Results show significant differences in sediment mixing depths and bioturbation coefficients among areas of the Mediterranean Sea characterised by different trophic regimes. In particular, in the Oran Rise area, where the Almeria-Oran Front induces frequent phytoplankton blooms, we calculate the highest values of sediment mixing layers (13 cm) and bioturbation coefficients (0.187 cm² yr⁻¹), and the highest values of ²¹⁰Pb(xs) and ¹³⁷Cs inventories. Intermediate values of SML and D(b) (~6 cm and ~0.040 cm² yr⁻¹, respectively) characterise the mesothrophic Algero-Balearic basin, while in the Southern Tyrrhenian Sea mixing parameters (SML of 3 cm and D(b) of 0.011 cm² yr⁻¹ are similar to those calculated for the oligotrophic Eastern Mediterranean (SML of 2 cm and D(b) of ~0.005 cm² yr⁻¹). PMID:21561644

  8. Model for reworked deltaic sands - Example from South Lake Arthur, Bayou Gentily, and Bayou Lery Fields

    SciTech Connect

    Saxena, R.S. )

    1990-09-01

    Reworked deltaic sands are beach-barrier sand bodies that are produced by the reworking of abandoned deltaic lobes. The facies association of these sand bodies makes them ideal reservoirs, and although abundant hydrocarbons are trapped in this type of sandstone, their genesis is seldom understood in the petroleum world. Criteria and models are developed for the recognition of reworked deltaic sand bodies from the subsurface by comparing a Holocene analog from the eastern periphery of the modern Mississippi delta with an ancient example from the Carboniferous of the northern Appalachian plateau. A simulated seismic model and several subsurface examples are presented.

  9. Semi-Automated Diagnosis, Repair, and Rework of Spacecraft Electronics

    NASA Technical Reports Server (NTRS)

    Struk, Peter M.; Oeftering, Richard C.; Easton, John W.; Anderson, Eric E.

    2008-01-01

    capacity and skill demands from exceeding crew time and training limits, the CLEAR project is examining options provided by non-real time tele-operations, robotics, and a new generation of diagnostic equipment. This paper outlines a strategy to create an effective repair environment where, with the support of ground based engineers, crewmembers can diagnose, repair and test flight electronics in-situ. This paper also discusses the implications of successful tele-robotic repairs when expanded to rework and reconfiguration of used flight assets for building Constellation infrastructure elements.

  10. 30 CFR 256.70 - Extension of lease by drilling or well reworking operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... well reworking operations are approved by the Secretary according to the conditions set forth in 30 CFR..., AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE...

  11. Reworked palynomorphs and their use in the determination of sedimentary cycles

    SciTech Connect

    Eshet, Y.; Druckman, Y.; Cousminer, H.L.; Habib, D.; Drugg, W.S.

    1988-07-01

    The Permian-Triassic sequence in the subsurface of Israel was deposited near the margin of the Arabian craton, which was a major source for both reworked organic and inorganic detritus. Three major depositional cycles are identified in this sequence, each consisting of a transgressive interval and a regressive interval. Analysis of the stratigraphic variation in the amounts of reworked palynomorphs indicates that they are most abundant in regressive intervals. This is considered to be a result of changes in the extent of exposed land, which was the source for the reworked palynomorphs, or of changes in the transportational regime. Stratigraphic variation in the abundance of reworked organic detritus may be useful for identifying depositional cycles that are not otherwise evident in the rock record.

  12. Life testing of reflowed and reworked advanced CCGA surface mount packages in harsh thermal environments

    NASA Astrophysics Data System (ADS)

    Ramesham, Rajeshuni

    2013-03-01

    Life testing/qualification of reflowed (1st reflow) and reworked (1st reflow, 1st removal, and then 1st rework) advanced ceramic column grid array (CCGA) surface mount interconnect electronic packaging technologies for future flight projects has been studied to enhance the mission assurance of JPL-NASA projects. The reliability of reworked/reflowed surface mount technology (SMT) packages is very important for short-duration and long-duration deep space harsh extreme thermal environmental missions. The life testing of CCGA electronic packages under extreme thermal environments (for example: -185°C to +125°C) has been performed with reference to various JPL/NASA project requirements which encompass the temperature range studied. The test boards of reflowed and reworked CCGA packages (717 Xilinx package, 624, 1152, and 1272 column Actel Packages) were selected for the study to survive three times the total number of expected temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware including all relevant manufacturing, ground operations, and mission phases or cycles to failure to assess the life of the hardware. Qualification/life testing was performed by subjecting test boards to the environmental harsh temperature extremes and assessing any structural failures, mechanical failures or degradation in electrical performance solder-joint failures due to either overstress or thermal cycle fatigue. The large, high density, high input/output (I/O) electronic interconnect SMT packages such as CCGA have increased usage in avionics hardware of NASA projects during the last two decades. The test boards built with CCGA packages are expensive and often require a rework to replace a reflowed, reprogrammed, failed, redesigned, etc., CCGA packages. Theoretically speaking, a good rework process should have similar temperature-time profile as that used for the original manufacturing process of solder reflow. A

  13. Reworking of Cretaceous dinosaurs into Paleocene channel deposits, upper Hell Creek Formation, Montana

    SciTech Connect

    Lofgren, D.L. ); Hotton, C.L. ); Runkel, A.C. )

    1990-09-01

    Dinosaur teeth from Paleocene channel fills have been interpreted as indicating dinosaur survival into the Paleocene. However, enormous potential for reworking exists because these records are restricted to large channel fills that are deeply incised into Cretaceous strata. Identification of reworked fossils is usually equivocal. This problem is illustrated by the Black Spring Coulee channel fill, a dinosaur-bearing Paleocene deposit in the upper Hell Creek Formation of eastern Montana. In this example, the reworked nature of well-preserved dinosaur bones is apparent only after detailed sedimentological and palynological analysis. Because of the potential for reworking, dinosaur remains derived from Paleocene fluvial deposits should not be assigned a Paleocene age unless the (1) are found in floodplain deposits, (2) are articulated, (3) are in channels that do not incise Cretaceous strata, or (4) are demonstrably reworked from Paleocene deposits. To date, reports of Paleocene dinosaurs do not fulfill any of these criteria. Thus, the proposal that dinosaurs persisted into the Paleocene remains unsubstantiated.

  14. Debris flow deposition and reworking by the Colorado River in Grand Canyon, Arizona

    USGS Publications Warehouse

    Yanites, B.J.; Webb, R.H.; Griffiths, P.G.; Magirl, C.S.

    2006-01-01

    Flow regulation by large dams affects downstream flow competence and channel maintenance. Debris flows from 740 tributaries in Grand Canyon, Arizona, transport coarse-grained sediment onto debris fans adjacent to the Colorado River. These debris fans constrict the river to form rapids and are reworked during river flows that entrain particles and transport them downstream. Beginning in 1963, flood control operations of Glen Canyon Dam limited the potential for reworking of aggraded debris fans. We analyzed change in debris fans at the mouths of 75-Mile and Monument Creeks using photogrammetry of aerial photography taken from 1965 to 2000 and supplemented with ground surveys performed from 1987 to 2005. Our results quantify the debris fan aggradation that resulted from debris flows from 1984 to 2003. Volume, area, and river constriction increased at both debris fans. Profiles of the two debris fans show that net aggradation occurred in the middle of debris fans at stages above maximum dam releases, and surface shape shifted from concave to convex. Dam releases above power plant capacity partially reworked both debris fans, although reworking removed much less sediment than what was added by debris flow deposition. Large dam releases would be required to create additional reworking to limit the rate of debris fan aggradation in Grand Canyon.

  15. Production inventory policies for defective items with inspection errors, sales return, imperfect rework process and backorders

    NASA Astrophysics Data System (ADS)

    Jaggi, Chandra K.; Khanna, Aditi; Kishore, Aakanksha

    2016-03-01

    In order to sustain the challenges of maintaining good quality and perfect screening process, rework process becomes a rescue to compensate for the imperfections present in the production system. The proposed model attempts to explore the existing real-life situation with a more practical approach by incorporating the concept of imperfect rework as this occurs as an unavoidable problem to the firm due to irreparable disorders even in the reworked items. Hence, a production inventory model is formulated here to study the combined effect of imperfect quality items, faulty inspection process and imperfect rework process on the optimal production quantity and optimal backorder level. An analytical method is employed to maximize the expected total profit per unit time. Moreover, the results of several previous research articles namely Chiu et al (2006), Chiu et al (2005), Salameh and Hayek (2001), and classical EPQ with shortages are deduced as special cases. To demonstrate the applicability of the model, and to observe the effects of key parameters on the optimal replenishment policy, a numerical example along with a comprehensive sensitivity analysis has been presented. The pertinence of the model can be found in most of the manufacturing industries like textile, electronics, furniture, footwear, plastics etc. A production lot size model has been explored for defectives items with inspection errors and an imperfect rework process.

  16. A family of reworkable polymer networks by the incorporation of sterically hindered urea linkages

    NASA Astrophysics Data System (ADS)

    Malik, Jitendra

    2002-01-01

    Crosslinked polymer networks are excellent materials for multiple applications. However, while their crosslinked structure gives the networks many positive attributes, it also makes them essentially intractable after the covalent crosslinks are formed. Therefore, it is exceedingly difficult to reprocess polymer networks once crosslinked without exposure to extreme degradation conditions. The first part of this work focuses in creating crosslinked networks that could show controlled disassembly upon stimulus. It was found that a controlled network disassembly process could be invoked by the incorporation of sterically hindered urea linkages into the polymer network. This network was shown to disassemble upon exposure to heat, whereas in the absence of heat, the network was found to maintain its crosslinked structure. The disassembly temperature could be varied by careful selection of the cleaving agent based on controllable considerations. This work focuses on showing controlled network disassembly of a crosslinked polymer matrix. Herein, we describe the factors that control the disassembly temperature and conclude with a possible mechanism for the disassembly process based on experimental data. Once disassembly could be shown to occur using sterically hindered urea linkages, polymer molecules were incorporated directly into the reworkable network. The presence of the polymer was found to significantly effect the reworkable behavior and these effects were detailed and an explanation for the behavior was provided. The work then focused on the effects of sterics along the length of the reworkable crosslinker. It was found that sterics along the length of the chain did have an effect. Specifically, as the steric hindrance increased around the urea linkage the rework temperature was found to decrease. Our focus then shifted to study the effects of changing the number of reworkable linkages per crosslinker. As the number per crosslinker changed from two to one the

  17. Characterizing and Modeling the Cost of Rework in a Library of Reusable Software Components

    NASA Technical Reports Server (NTRS)

    Basili, Victor R.; Condon, Steven E.; ElEmam, Khaled; Hendrick, Robert B.; Melo, Walcelio

    1997-01-01

    In this paper we characterize and model the cost of rework in a Component Factory (CF) organization. A CF is responsible for developing and packaging reusable software components. Data was collected on corrective maintenance activities for the Generalized Support Software reuse asset library located at the Flight Dynamics Division of NASA's GSFC. We then constructed a predictive model of the cost of rework using the C4.5 system for generating a logical classification model. The predictor variables for the model are measures of internal software product attributes. The model demonstrates good prediction accuracy, and can be used by managers to allocate resources for corrective maintenance activities. Furthermore, we used the model to generate proscriptive coding guidelines to improve programming, practices so that the cost of rework can be reduced in the future. The general approach we have used is applicable to other environments.

  18. [Features and Outcomes of Reinstated "Return-to-Work (Re-work)" Program Participants].

    PubMed

    Soeda, Shuji

    2016-03-01

    Though effects of the return-to-work (re-work) program on reinstatement started being reported, factors related to the outcomes are unclear. As a case series, we discuss the outcomes of reinstatement and the characteristics of large-scale assembly-factory workers (our case) who had attended a medical institution's re-work program. On examining the five successful reinstatement cases and five failed cases, motivation for reinstatement, understanding program requirements, adaptability, and personality traits were found to contribute to these outcomes. We also discussed two failed cases wherein young employees retired after the re-work program. They felt to be disconnected from their work and finally retired. PMID:26972944

  19. The optimal manufacturing batch size with rework under time-varying demand process for a finite time horizon

    NASA Astrophysics Data System (ADS)

    Musa, Sarah; Supadi, Siti Suzlin; Omar, Mohd

    2014-07-01

    Rework is one of the solutions to some of the main issues in reverse logistic and green supply chain as it reduces production cost and environmental problem. Many researchers focus on developing rework model, but to the knowledge of the author, none of them has developed a model for time-varying demand rate. In this paper, we extend previous works and develop multiple batch production system for time-varying demand rate with rework. In this model, the rework is done within the same production cycle.

  20. Evidence of reworked Cretaceous fossils and their bearing on the existence of Tertiary dinosaurs

    SciTech Connect

    Eaton, J.G. ); Kirkland, J.I. ); Doi, K. )

    1989-06-01

    The Paleocene Shotgun fauna of Wyoming includes marine sharks as well as mammals. It has been suggested that the sharks were introduced from the Cannonball Sea. It is more likely that these sharks were reworked from a Cretaceous rock sequence that included both marine and terrestrial deposits as there is a mixture of marine and freshwater taxa. These taxa have not been recorded elsewhere after the Cretaceous and are not known from the Cannonball Formation. Early Eocene localities at Raven Ridge, Utah, similarly contain teeth of Cretaceous marine and freshwater fish, dinosaurs, and Eocene mammals. The Cretaceous teeth are well preserved, variably abraded, and serve to cast doubts on criteria recently used to claim that dinosaur teeth recovered from the Paleocene of Montana are not reworked. Another Eocene locality in the San Juan Basin has produced an Eocene mammalian fauna with diverse Cretaceous marine sharks. Neither the nature of preservation nor the degree of abrasion could be used to distinguish reworked from contemporaneous material. The mixed environments represented by the fish taxa and recognition of the extensive pre-Tertiary extinction of both marine and freshwater fish were employed to recognize reworked specimens.

  1. The role of radiogenic heat in prolonged intraplate reworking: The Capricorn Orogen explained?

    NASA Astrophysics Data System (ADS)

    Korhonen, Fawna J.; Johnson, Simon P.

    2015-10-01

    Links between intraplate crustal deformation and the thermal regime of the lithosphere have been investigated using numerical models, but these conceptual models must be tested using well-constrained natural systems. The Proterozoic Capricorn Orogen of Western Australia is ideally suited for such a study; after arc accretion, it records a protracted history of intracrustal differentiation and over one billion years of subsequent tectonic reworking. The early addition of juvenile arc material initially reduced the heat production of the crust, whereas subsequent recycling of the deep crust ultimately produced radiogenic granites in the shallow crust. Using whole rock and magmatic zircon compositions, we show that the shallow crust of the Capricorn Orogen has been progressively enriched in heat-producing elements with time. The high heat production is mainly controlled by thorium, concentrated in LREE-enriched phosphates that grew during the late stages of crystallization of crustally-derived granites. Using a numerical model, we investigate the thermal effects of this evolved crustal stratification and compare them with quantitative data on the pressure-temperature-time evolution of a non-magmatic Mesoproterozoic reworking event. The results provide new information concerning the process by which the thermal conditions necessary for the reworking of orogenic crust are generated and sustained for prolonged timescales (>110 Ma). Furthermore, we demonstrate that perturbations to the radiogenic crust lead to warmer geotherms and consequent lithospheric weakening, which has a fundamental control on intraplate reworking of long-lived orogens.

  2. Model Specification for Rework of Aircraft Engine, Power Transmission, and Accessory/Auxiliary Ball and Roller Bearings

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.; Branzai, Emanuel V.

    2007-01-01

    This document provides a model specification for the rework and/or repair of bearings used in aircraft engines, helicopter main power train transmissions, and auxiliary bearings determined to be critical by virtue of performance, function, or availability. The rolling-element bearings to be processed under the provisions of this model specification may be used bearings removed after service, unused bearings returned from the field, or certain rejected bearings returned for reinspection and salvage. In commercial and military aircraft application, it has been a practice that rolling-element bearings removed at maintenance or overhaul be reworked and returned to service. Depending on the extent of rework and based upon theoretical analysis, representative life factors (LF) for bearings subject to rework ranged from 0.87 to 0.99 the lives of new bearings. Based on bearing endurance data, 92 percent of the bearing sets that would be subject to rework would result in L(sub 10) lives equaling and/or exceeding that predicted for new bearings. The remaining 8 percent of the bearings have the potential to achieve the analytically predicted life of new bearings when one of the rings is replaced at rework. The potential savings from bearing rework varies from 53 to 82 percent of that of new bearings depending on the cost, size, and complexity of the bearing

  3. The permian sequence reconstructed from reworked carbonate clasts in the Batain Plain (northeastern Oman)

    NASA Astrophysics Data System (ADS)

    Hauser, Marc; Vachard, Daniel; Martini, Rossana; Matter, Albert; Peters, Tjerk; Zaninetti, Louisette

    2000-02-01

    An almost complete Permian sequence is reworked in the conglomerates and sandstones of the Aseelah Unit forming the lower part of the Batain Croup. This series of Late Permian to Earliest Triassic age overlies conformably the Qarari Unit, dated as Middle Permian by ammonoids. The bioclastic limestone pebbles and boulders deposited on shallow marine-shelf environments yield diversified assemblages of dasyclads, red algae, fusulinids and smaller foraminifers, indicating Yakhtashian, Bolorian, Kubergandian, Early Murgabian, Midian and Dzhulfian ages (systematic work in progress).

  4. Coral-rubble ridges as dynamic coastal features - short-term reworking and weathering processes

    NASA Astrophysics Data System (ADS)

    Spiske, Michaela

    2016-02-01

    A coral-rubble ridge built by storm waves at Anegada (British Virgin Islands) underwent remarkable changes in shape and weathering in a 23-month period. The ridge is located along the island's north shore, in the lee of a fringing reef and a reef flat. This coarse-clast ridge showed two major changes between March 2013, when first examined, and February 2015, when revisited. First, a trench dug in 2013, and intentionally left open for further examination, was found almost completely infilled in 2015, and the ridge morphology was modified by slumping of clasts down the slope and by reworking attributable to minor storm waves. In size, composition and overall condition, most of the clasts that filled the trench resemble reworked clasts from the ridge itself; only a small portion had been newly brought ashore. Second, a dark gray patina formed on the whitish exteriors of the carbonate clasts that had been excavated in 2013. These biologically weathered, darkened clasts had become indistinguishable from clasts that had been at the ridge surface for a much longer time. The findings have two broader implications. First, coastal coarse-clast ridges respond not solely to major storms, but also to tropical storms or minor hurricanes. The modification and reworking of the ridge on Anegada most probably resulted from hurricane Gonzalo which was at category 1-2 as it passed about 60 km north of the island in October 2014. Second, staining of calcareous clasts by cyanobacteria in the supralittoral zone occurs within a few months. In this setting, the degree of darkening quickly saturates as a measure of exposure age.

  5. Deformation patterns, reworking and low-angled extension on Kythnos, W. Cyclades

    NASA Astrophysics Data System (ADS)

    Rice, A. H. N.; Grasemann, B.; Schneider, D.; Lenauer, I.; Laner, G.

    2010-05-01

    Southwards rollback of the African plate from the Cretan subduction zone led to extension of the continental crust underlying the Aegean sea. Top-to-SW low-angled extension (D2/M2) recorded in the W. Cyclades (Makronisos-Kea-Kythnos-Serifos-Sifnos) was superimposed on an earlier (D1/M1) southerly-directed high-P exhumation event at ~30 Ma; in some islands, blueschists are recognisable at outcrops, whilst in others only relicts have been found in thin-sections. Due to rotation of the Cyclades region high-P exhumation, early stretching lineations (L1) are now ENE-WSW oriented, at an angle to subsequent NE-SW oriented low-angled detachment lineations (L2). This difference can be used to qualitatively estimate the intensity of D2 structural reworking of D1, although the small angle between L1 and L2 azimuths makes it difficult to determine which generation is present in the field for intermediate orientations. On Kea (NW end of W. Cyclades), only relict blueschist assemblages have been preserved in greenschist facies rocks and structural reworking was strong; stretching and crenulation lineations are overwhelmingly dominated by L2 directions (~040°), with abundant top-to-SW S-C' fabrics. On Kythnos, just 11.5 km SE of Kea, evidence of high-P metamorphism has also only been seen in thin-sections, in greenschists, but, despite this, structural overprinting was weak and predominantly L1 (~070°) stretching lineations are present. Only in the southernmost part of the island, where the detachment fault and hanging wall are exposed, are L2 directions (~040°) common. Currently available Ar/Ar phengitic white mica cooling age data shows a range of 24-19 Ma (N=5), from samples including both early and late lineation directions; these data are similar to those from Kea (13-21 Ma). A minor late brittle detachment on the east coast, with (ultra)cataclasites up to 0.5 m thick, has south-dipping Riedel shears and weak southerly-plunging lineations, indicating a late evolution. A

  6. Late Pleistocene Major Sedimentary Reworking Event (Homogenite) in Marmara Sea Central Basin

    NASA Astrophysics Data System (ADS)

    Beck, C.; Schneider, J.-L.; Mercier de Lépinay, B.; Cagatay, N.; Labeyrie, L.; Wendenbaum, E.; Boutareau, S.; Ménot-Combes, G.; Hadjas, I.; Turon, J.-L.; Marmacore Scientific Party

    2003-04-01

    Among eight long piston-cores retrieved during MARMACORE Cruise, two were dedicated to the Marmara Sea Central Basin especially for paleoseismic purpose. There, very high-resolution profiles evidenced a main acoustically transparent unit ponded in the whole basin and resembling the so-called " homogenite " described in central-eastern Mediterranean and in deep lakes. Core MD01-2431 (26.4 m) crossed a major sedimentary event comprising three parts, from bottom to top : 0.7 m of mud clasts within coarse sand, 1.9 m of poorly-stratified sand, and 4.8 m of homogenous clayey silt (top at 15.2 m bsf). Two wood-fragments found in the homogenous horizon (60 cm-separated) yielded 17 100 yrs BP calibrated AMS C14 values. Textural investigation on involved sediments lead to consider the whole set as a unique reworking event with : mass waisting evolving into turbidite, basal liquefaction and erosion of in situ fine sediments, segregation by oscillation (seiche-like or constrained turbidite effect) of finer fraction. If admitting a triggering of the whole set by an earthquake comparable to the strongest historical ones, the unusual reworked volume of soft sediments could be explained by an occurrence during a period of particularly high terrigenous supply.

  7. Sand wave fields beneath the Loop Current, Gulf of Mexico: Reworking of fan sands

    USGS Publications Warehouse

    Kenyon, Neil H.; Akhmetzhanov, A.M.; Twichell, D.C.

    2002-01-01

    Extensive fields of large barchan-like sand waves and longitudinal sand ribbons have been mapped by deep-towed SeaMARC IA sidescan sonar on part of the middle and lower Mississippi Fan that lies in about 3200 m of water. The area is beneath the strongly flowing Loop Current. The bedforms have not been adequately sampled but probably consist of winnowed siliciclastic-foraminiferal sands. The size (about 200 m from wingtip to wingtip) and shape of the large barchans is consistent with a previously observed peak current speed of 30 cm/s, measured 25 m above the seabed. The types of small-scale bedforms and the scoured surfaces of chemical crusts, seen on nearby bottom photographs, indicate that near-bed currents in excess of 30 cm/s may sometimes occur. At the time of the survey the sand transport direction was to the northwest, in the opposite direction to the Loop Current but consistent with there being a deep boundary current along the foot of the Florida Escarpment. Some reworking of the underlying sandy turbidites and debris flow deposits is apparent on the sidescan sonar records. Reworking by deep-sea currents, resulting in erosion and in deposits characterised by coarsening upwards structures and cross-bedding, is a process that has been proposed for sand found in cores in shallower parts of the Gulf of Mexico. This process is more widespread than hitherto supposed. ?? 2002 Published by Elsevier Science B.V.

  8. Debris-flow dominance of alluvial fans masked by runoff reworking and weathering

    NASA Astrophysics Data System (ADS)

    de Haas, Tjalling; Ventra, Dario; Carbonneau, Patrice E.; Kleinhans, Maarten G.

    2014-07-01

    Arid alluvial fan aggradation is highly episodic and fans often comprise active and inactive sectors. Hence the morphology and texture of fan surfaces are partly determined by secondary processes of weathering and erosion in addition to primary processes of aggradation. This introduces considerable uncertainty in the identification of formative processes of terrestrial and Martian fans from aerial and satellite imagery. The objectives of this study are (i) to develop a model to describe the sedimentological and morphological evolution of inactive fan surfaces in arid settings, and (ii) to assess the relative importance of primary processes of aggradation and secondary processes of weathering and reworking for surface morphology and sedimentology and for the stratigraphic record. We studied an alluvial fan characterized by a recently active sector and a long-abandoned, inactive sector along the coast of the hyperarid Atacama Desert. Here, rates of primary geomorphic activity are exceptionally low because of extreme aridity, while weathering rates are relatively high because of the effects of coastal fogs. Long-term processes of fan aggradation and reworking were determined through sedimentological facies analysis of stratigraphic sections. Ground surveys for textural and morphological patterns at the fan surface were integrated with remote-sensing by an Unmanned Airborne Vehicle (UAV). Discharges and sediment-transport capacities were calculated to estimate the efficiency of secondary runoff in reshaping the inactive fan sector. Stratigraphic sections reveal that the fan was dominantly aggraded by debris flows, whereas surface morphology is dominated by debris-flow signatures in the active sector and by weathering and runoff on the inactive sector. On the latter, rapid particle breakdown prevents the formation of a coarse desert pavement. Furthermore, relatively frequent local runoff events erode proximal debris-flow channels on the inactive sector to form local lag

  9. Mathematical modeling of a multi-product EMQ model with an enhanced end items issuing policy and failures in rework.

    PubMed

    Chiu, Yuan-Shyi Peter; Sung, Peng-Cheng; Chiu, Singa Wang; Chou, Chung-Li

    2015-01-01

    This study uses mathematical modeling to examine a multi-product economic manufacturing quantity (EMQ) model with an enhanced end items issuing policy and rework failures. We assume that a multi-product EMQ model randomly generates nonconforming items. All of the defective are reworked, but a certain portion fails and becomes scraps. When rework process ends and the entire lot of each product is quality assured, a cost reduction n + 1 end items issuing policy is used to transport finished items of each product. As a result, a closed-form optimal production cycle time is obtained. A numerical example demonstrates the practical usage of our result and confirms a significant savings in stock holding and overall production costs as compared to that of a prior work (Chiu et al. in J Sci Ind Res India, 72:435-440 2013) in the literature.

  10. Migrant labor takes a holiday. Reworking modernity and marginality in contemporary Thailand.

    PubMed

    Mills, M B

    1999-03-01

    This paper examines the practice of working-class group excursions in Thailand, organized by and for rural labor migrants in Bangkok. These trips involve traditional forms of Buddhist ceremonial as well as more self-consciously "modern" sightseeing activities in distant regions of the country. More than just a welcome respite from the drudgery and discipline of factory jobs, these excursions allow labor migrants to make important claims about their experiences as members of the Thai nation-state. As tourist-consumers, migrant workers appropriate powerful signs and symbols of modern Thai identity and status, in doing so they contest (and at least partly rework) their material and ideological marginalization within contemporary Thai society. PMID:12349696

  11. Migrant labor takes a holiday. Reworking modernity and marginality in contemporary Thailand.

    PubMed

    Mills, M B

    1999-03-01

    This paper examines the practice of working-class group excursions in Thailand, organized by and for rural labor migrants in Bangkok. These trips involve traditional forms of Buddhist ceremonial as well as more self-consciously "modern" sightseeing activities in distant regions of the country. More than just a welcome respite from the drudgery and discipline of factory jobs, these excursions allow labor migrants to make important claims about their experiences as members of the Thai nation-state. As tourist-consumers, migrant workers appropriate powerful signs and symbols of modern Thai identity and status, in doing so they contest (and at least partly rework) their material and ideological marginalization within contemporary Thai society.

  12. The connection between crustal reworking and petrological diversity in the deep crust: clues from migmatites

    NASA Astrophysics Data System (ADS)

    Carvalho, Bruna B.; Sawyer, Edward W.; de Assis Janasi, Valdecir

    2016-04-01

    The deep levels of the continental crust have been extensively reworked as result of crustal differentiation. Migmatites are widespread in these high-grade metamorphic terrains, and provide valuable information on how processes such as partial melting, segregation of the melt from the residue and subsequent chemical exchanges lead to the petrological diversity found in the deep crust. This study investigates processes that transformed a largely uniform, metagranodiorite protolith into a very complex migmatite that contains three varieties of diatexites (grey, schlieren and homogenous diatexites) and several types of leucosomes. The Kinawa Migmatite is part of the Archean TTG crust in the São Francisco Craton (Brazil), which has been reworked in a shear zone environment at upper amphibolite facies conditions (<730°C and 5-6 kbar); thus it may be typical of crustal reworking in the interior of old cratons [1]. Grey diatexites are residual rocks formed by the extraction of a water-fluxed melt created via the reaction Pl + Kfs + Qz + H2O = melt. Diversity within the grey diatexites arises from different degrees of melt segregation (maximum ~40% melt). Schlieren diatexites are very heterogeneous rocks in which residuum-rich domains alternate with leucocratic quartzo-feldspathic domains where melt accumulated. Homogeneous diatexites are coarse-grained leucocratic rocks and represent larger bodies of anatectic melt with minor amounts (<20%) of entrained residuum. Leucosomes display a wide range of compositions from tonalitic to alkali-feldspar granite. Leucosomes, homogeneous diatexites and the quartzo-feldspathic domains in the schlieren diatexites all show a sequence of microstructural stages from plagioclase-dominated to K-feldspar-dominated frameworks many of which show evidence for tectonic compaction. Thus, further segregation of melt from solids occurred during crystallization. Minor amphibolite dykes in the metagranodiorite did not melt. They occur as angular to

  13. [Support for Adult ASD in Medical Rework Program: Mutual Communication Program and Psychodrama].

    PubMed

    Yokoyama, Motonori

    2015-01-01

    While carrying out the Medical Rework Program, we realized the necessity for a supplementary medical treatment program aimed at adult ASD. Consequently, we started the Mutual Communication Program, which consists of standard SST and the new element of psychodrama. As a result, 32 participants have returned to their workplace in the three-year period, and the rate of successfully continuing to work was 93.8% at the time of the investigation. Various psychological tests also indicated significant improvement. In this article, we present a case study, explain psychodrama techniques employed in the program, and discuss their usefulness. The results suggest that psychodrama is a very effective assistive technique when the characteristics of ASD are taken into consideration.

  14. [Support for Adult ASD in Medical Rework Program: Mutual Communication Program and Psychodrama].

    PubMed

    Yokoyama, Motonori

    2015-01-01

    While carrying out the Medical Rework Program, we realized the necessity for a supplementary medical treatment program aimed at adult ASD. Consequently, we started the Mutual Communication Program, which consists of standard SST and the new element of psychodrama. As a result, 32 participants have returned to their workplace in the three-year period, and the rate of successfully continuing to work was 93.8% at the time of the investigation. Various psychological tests also indicated significant improvement. In this article, we present a case study, explain psychodrama techniques employed in the program, and discuss their usefulness. The results suggest that psychodrama is a very effective assistive technique when the characteristics of ASD are taken into consideration. PMID:26524848

  15. An EMQ inventory model for defective products involving rework and sales team's initiatives-dependent demand

    NASA Astrophysics Data System (ADS)

    Priyan, S.; Uthayakumar, R.

    2015-07-01

    This paper investigates the issue of an economic manufacturing quantity model for defective products involving imperfect production processes and rework. We consider that the demand is sensitive to promotional efforts/sales teams' initiatives as well as the setup cost can be reduced through further investment. It also assumes that fixed quantity multiple installments of the finished batch are delivered to customers at a fixed interval of time. The long-run average cost function is derived and its convexity is proved via differential calculus. An effective iterative solution procedure is developed to achieve optimal replenishment lot-size, setup cost and the initiatives of sales teams so that the total cost of system is minimized. Numerical and sensitivity analyses are performed to evaluate the outcome of the proposed solution procedure presented in this research.

  16. Effect of physical sediments reworking on hydrocarbon degradation and bacterial community structure in marine coastal sediments.

    PubMed

    Duran, Robert; Bonin, Patricia; Jezequel, Ronan; Dubosc, Karine; Gassie, Claire; Terrisse, Fanny; Abella, Justine; Cagnon, Christine; Militon, Cecile; Michotey, Valérie; Gilbert, Franck; Cuny, Philippe; Cravo-Laureau, Cristiana

    2015-10-01

    The present study aimed to examine whether the physical reworking of sediments by harrowing would be suitable for favouring the hydrocarbon degradation in coastal marine sediments. Mudflat sediments were maintained in mesocosms under conditions as closer as possible to those prevailing in natural environments with tidal cycles. Sediments were contaminated with Ural blend crude oil, and in half of them, harrowing treatment was applied in order to mimic physical reworking of surface sediments. Hydrocarbon distribution within the sediment and its removal was followed during 286 days. The harrowing treatment allowed hydrocarbon compounds to penetrate the first 6 cm of the sediments, and biodegradation indexes (such as n-C18/phytane) indicated that biodegradation started 90 days before that observed in untreated control mesocosms. However, the harrowing treatment had a severe impact on benthic organisms reducing drastically the macrofaunal abundance and diversity. In the harrowing-treated mesocosms, the bacterial abundance, determined by 16S rRNA gene Q-PCR, was slightly increased; and terminal restriction fragment length polymorphism (T-RFLP) analyses of 16S rRNA genes showed distinct and specific bacterial community structure. Co-occurrence network and canonical correspondence analyses (CCA) based on T-RFLP data indicated the main correlations between bacterial operational taxonomic units (OTUs) as well as the associations between OTUs and hydrocarbon compound contents further supported by clustered correlation (ClusCor) analysis. The analyses highlighted the OTUs constituting the network structural bases involved in hydrocarbon degradation. Negative correlations indicated the possible shifts in bacterial communities that occurred during the ecological succession.

  17. Effect of physical sediments reworking on hydrocarbon degradation and bacterial community structure in marine coastal sediments.

    PubMed

    Duran, Robert; Bonin, Patricia; Jezequel, Ronan; Dubosc, Karine; Gassie, Claire; Terrisse, Fanny; Abella, Justine; Cagnon, Christine; Militon, Cecile; Michotey, Valérie; Gilbert, Franck; Cuny, Philippe; Cravo-Laureau, Cristiana

    2015-10-01

    The present study aimed to examine whether the physical reworking of sediments by harrowing would be suitable for favouring the hydrocarbon degradation in coastal marine sediments. Mudflat sediments were maintained in mesocosms under conditions as closer as possible to those prevailing in natural environments with tidal cycles. Sediments were contaminated with Ural blend crude oil, and in half of them, harrowing treatment was applied in order to mimic physical reworking of surface sediments. Hydrocarbon distribution within the sediment and its removal was followed during 286 days. The harrowing treatment allowed hydrocarbon compounds to penetrate the first 6 cm of the sediments, and biodegradation indexes (such as n-C18/phytane) indicated that biodegradation started 90 days before that observed in untreated control mesocosms. However, the harrowing treatment had a severe impact on benthic organisms reducing drastically the macrofaunal abundance and diversity. In the harrowing-treated mesocosms, the bacterial abundance, determined by 16S rRNA gene Q-PCR, was slightly increased; and terminal restriction fragment length polymorphism (T-RFLP) analyses of 16S rRNA genes showed distinct and specific bacterial community structure. Co-occurrence network and canonical correspondence analyses (CCA) based on T-RFLP data indicated the main correlations between bacterial operational taxonomic units (OTUs) as well as the associations between OTUs and hydrocarbon compound contents further supported by clustered correlation (ClusCor) analysis. The analyses highlighted the OTUs constituting the network structural bases involved in hydrocarbon degradation. Negative correlations indicated the possible shifts in bacterial communities that occurred during the ecological succession. PMID:25847440

  18. New residence times of the Holocene reworked shells on the west coast of Bohai Bay, China

    NASA Astrophysics Data System (ADS)

    Shang, Zhiwen; Wang, Fu; Li, Jianfen; Marshall, William A.; Chen, Yongsheng; Jiang, Xingyu; Tian, Lizhu; Wang, Hong

    2016-01-01

    Shelly cheniers and shell-rich beds found intercalated in near-shore marine muds and sandy sediments can be used to indicate the location of ancient shorelines, and help to estimate the height of sea level. However, dating the deposition of material within cheniers and shell-rich beds is not straightforward because much of this material is transported and re-worked, creating an unknown temporal off-set, i.e., the residence time, between the death of a shell and its subsequent entombment. To quantify the residence time during the Holocene on a section of the northern Chinese coastline a total 47 shelly subsamples were taken from 17 discrete layers identified on the west coast of Bohai Bay. This material was AMS 14C dated and the calibrated ages were systematically compared. The subsamples were categorized by type as articulated and disarticulated bivalves, gastropod shells, and undifferentiated shell-hash. It was found that within most individual layers the calibrated ages of the subsamples got younger relative to the amount of apparent post-mortem re-working the material had been subject to. For examples, the 14C ages of the bivalve samples trended younger in this order: shell-hash → split shells → articulated shells. We propose that the younger subsample age determined within an individual layer will be the closest to the actual depositional age of the material dated. Using this approach at four Holocene sites we find residence times which range from 100 to 1260 cal yrs, with two average values of 600 cal yrs for the original 14C dates older than 1 ka cal BP and 100 cal yrs for the original 14C dates younger than 1 ka cal BP, respectively. Using this semi-empirical estimation of the shell residence times we have refined the existing chronology of the Holocene chenier ridges on the west coast of Bohai Bay.

  19. Middle Miocene reworked turbidites in the Baiyun Sag of the Pearl River Mouth Basin, northern South China Sea margin: Processes, genesis, and implications

    NASA Astrophysics Data System (ADS)

    Gong, Chenglin; Wang, Yingmin; Zheng, Rongcai; Hernández-Molina, F. Javier; Li, Yun; Stow, Dorrik; Xu, Qiang; Brackenridge, Rachel E.

    2016-10-01

    Our understanding of reworked turbidites is still in its infancy, and their flow processes and genesis still remain understudied. Core data from the middle Miocene Zhujiang Formation in the Pearl River Mouth Basin allow us to differentiate reworked turbidites, yielding two main contributions. Firstly, reworked turbidites are distinguished from turbidites by the association of traction structures and tidal signatures, which occur in discrete units rather than forming a classic "Bouma Sequence" for turbidites. Sedimentological characteristics of reworked turbidites proposed here will help to obtain a robust set of diagnostic criteria for the recognition of deep-water non-turbidite deepwater units as reservoirs. Secondly, our results suggest that, in the down-slope direction, classic detritus carried in turbidity flows would synchronously be bidirectionally reworked by internal tides and waves, resulting in tidal signatures seen in the interpreted reworked turbidites. In the along-slope direction, upper parts of dilute turbidity currents would mix vertically with seawater, and muddy fines would be winnowed away by contour currents, whereas lower parts of dilute turbidity currents would probably drop their coarse particles, resulting in traction structures recognized in the documented reworked turbidites. Our work highlights the influence of bottom currents on the development and modification of turbidites and suggests that reworked turbidites were created by the combined action of down-slope transport and reworking and along-slope winnowing and sorting, helping to better understand flow processes and genesis of non-turbidite reservoirs with a great economic interest.

  20. Viable School Improvement Requires a Developmental Strategy that Moves beyond the Skewed Wish List and Reworks Operational Infrastructure. A Center Brief

    ERIC Educational Resources Information Center

    Center for Mental Health in Schools at UCLA, 2011

    2011-01-01

    factors affecting learning and teaching and how the operational infrastructure is reworked to enable strategic and effective development of essential interventions. This is especially so for schools that…

  1. Study of thermally reworkable epoxy materials and thermal conductivity enhancement using carbon fiber for electronics packaging

    NASA Astrophysics Data System (ADS)

    Li, Haiying

    Epoxy resins are widely used as the underfill materials for the integrated circuit (IC) chips for the reliability enhancement and as the binder of electrically conductive adhesives (ECA). However, cured epoxy materials are infusible and insoluble networks which is a problem for the repair of a printed circuit board assembly packaged with epoxy materials. In this study, six diepoxides containing aromatic moieties and low temperature degradable linkages, secondary and tertiary benzoates, and carbonates, were synthesized and characterized. Underfills based on four of these epoxides were developed and evaluated respect to their properties and reworkabilility. One of the reworkable underfills was evaluated with the 85°C/85% relative humidity test as the underfill of several ball-grid-array components on a organic board, which showed a high enhanced reliability. Underfill materials based on a synthesized bisphenol-A diepoxide were developed for the no-flow underfill process and were evaluated regarding the application on both tin/lead and lead-free solders. The latent curing mechanism of the catalyst and the influence of fluxing agents were studied. The reworkable underfills showed satisfying overall properties on both Sn/Pb and Sn/Ag/Cu solders. A unique approach for solving the problem of low reliability of ECAs was demonstrated. Small amount of sacrificial metal and alloy powders were added in silver flake based ECA and applied on six pad surfaces. The aging of bulk resistivity and contact resistance of ECA/metal surface pairs were studied and two alloys stabilized the contact resistance on all tested metal surfaces. The internal heat generation of IC devices quickly increases which leads to deteriorated performance and low reliability. The thermally insulating property of polymeric underfills make this even worse with slow heat dissipation. In this study, a carbon fiber of high thermal conductivity was used together with silica in epoxy underfill materials and a 300

  2. Reworked loess and Yellow River sediment as the main sources of the Chinese Loess Plateau

    NASA Astrophysics Data System (ADS)

    Licht, Alexis; Pullen, Alex; Kapp, Paul; Abell, jordan; Giesler, Dominique

    2016-04-01

    The Quaternary aeolian dust deposits of the Chinese Loess Plateau have been attributed to spring and winter monsoonal storms sweeping clastic material from the deserts of the Asian interior into central China. Recent U-Pb geochronological studies of aeolian zircons have emphasized the existence of two major wind pathways: from the north, throughout the Tengger, and Mu Us deserts during interglacials, and from the west, through the Qaidam Basin during glacials. Others have emphasized the importance of Yellow River supply in the Loess Plateau sediment budget. However, tracking dust source regions through U-Pb dating is particularly complex, given the paucity of data in many potential sources regions and the similar ages peak in the age probability distributions of western and Northern deserts in central China. Here, we present an extended dataset of U-Pb ages covering all the potential provenance areas for the aeolian dust in central Asia and including 2400 new ages from loess, paleosols, modern sand dunes and fluvial deposits. We then propose a new mixture modeling technique to statistically address the contribution of these different sources to the Loess Plateau sedimentary budget. Our contribution estimates indicate that aeolian supply is dominated (60-70 %) by reworking of Yellow River sediment. Moreover, evidence of Qaidam Basin sourced zircons (15-20 %) in both loess (glacial) and paleosols (interglacial) layers corroborates the existence of an erosive wind pathway from the west during glacials and implies that a substantial portion of the interglacial dust is recycled from older glacial loess. We propose that sediment reworking of Yellow River sediment and older loesses by wind homogenizes aeolian zircon populations on the Chinese Loess Plateau toward a glacial provenance due to higher dust accumulation rates during glacials. These findings indicate that the Loess Plateau has evolved as a more dynamic landform than previous thought where wind deflation

  3. Early Cretaceous extensional reworking of the Triassic HP-UHP metamorphic orogen in Eastern China

    NASA Astrophysics Data System (ADS)

    Lin, Wei; Ji, Wenbin; Faure, Michel; Wu, Lin; Li, Qiuli; Shi, Yonghong; Scharer, Urs; Wang, Fei; Wang, Qingchen

    2015-11-01

    Corresponding to the Early Mesozoic continental subduction between the North China Block (NCB) and the South China Block (SCB), the Tongbaishan-Hong'an-Dabieshan-Sulu massifs are famous for their HP-UHP metamorphism. More than 50% of the HP-UHP Orogenic Belt was significantly reworked by Early Cretaceous extensional tectonics. This Early Cretaceous event with a fast cooling period, at 130-120 Ma, superimposed on the Early Mesozoic HP-UHP orogenic belt and intensively changed the architecture of this orogen. Each individual segment documents different Early Cretaceous extensional structures, namely the central Tongbaishan domain is a metamorphic core complex (MCC) represented by an A-type non-cylindrical antiform; the central Dabieshan domain is a typical Cordilleran-type migmatite-cored MCC; the Southern Sulu UHP domain is a "wedge-shaped" structure exhumed by a simple detachment fault. These late stage extensional structures expose the previous HP-UHP orogenic belt as fragments along the NCB-SCB boundary. The geodynamic setting of this Early Cretaceous extensional tectonics along the HP-UHP orogen is a part of a 1000 km-scale crustal extension belt that is widespread in eastern Eurasia continent from Trans-Baikal to the central part of SCB. Convective erosion or delamination of the mantle lithosphere might be considered as a possible mechanism for mantle removal.

  4. Early Cretaceous extensional reworking of the Triassic HP-UHP metamorphic orogen in Eastern China

    NASA Astrophysics Data System (ADS)

    Lin, W.; Ji, W.; Faure, M.; Wu, L.; Li, Q. L.; Shi, Y.; Scharer, U.; Wang, F.; Wang, Q.

    2015-12-01

    Corresponding to the Early Mesozoic continental subduction between the North China Block (NCB) and the South China Block (SCB), the Tongbaishan-Hong'an-Dabieshan-Sulu massifs are famous for their HP-UHP metamorphism. More than 50% of the HP-UHP Orogenic Belt was significantly reworked by Early Cretaceous extensional tectonics. This Early Cretaceous event with a fast cooling period, at 130-120 Ma, superimposed on the Early Mesozoic HP-UHP orogenic belt and intensively changed the architecture of this orogen. Each individual segment documents different Early Cretaceous extensional structures, namely the central Tongbaishan domain is a metamorphic core complex (MCC) represented by an A-type non-cylindrical antiform; the central Dabieshan domain is a typical Cordilleran-type migmatite-cored MCC; the Southern Sulu UHP domain is a "wedge-shaped" structure exhumed by a simple detachment fault. These late stage extensional structures expose the previous HP-UHP orogenic belt as fragments along the NCB-SCB boundary. The geodynamic setting of this Early Cretaceous extensional tectonics along the HP-UHP orogen is a part of a 1000 km-scale crustal extension belt that is widespread in eastern Eurasia continent from Trans-Baikal to the central part of the South China Block. Convective erosion or delamination of the mantle lithosphere might be considered as a possible mechanism for mantle removal.

  5. Problems associated with reworked teeth in electron spin resonance (ESR) dating

    NASA Astrophysics Data System (ADS)

    Blackwell, Bonnie A.

    A single radiation-sensitive ESR signal at g = 2.0018 occurs in well crystallized fossil tooth enamel, but not in modern teeth. In dating fossil teeth, the equivalent radiation dose (A Σ needed to produce the observed ESR signal is the integral, with respect to time, of the natural, environmental dose rate experienced by the tooth after its deposition. Regardless of the uranium (U) uptake history assumed, a reliable age estimate requires a good estimate for the external dose rate during the tooth's history. If teeth in a stratigraphic unit have been reworked from older units or are post-depositional intrusions, external dose rates measured in situ do not accurately reflect those experienced by the tooth. For teeth from a single unit, significant variations in the calculated ages, A Σs, enamel or dentine U concentrations all indicate mixed sample collections. Where enough subsamples can be collected from single teeth, isochron analyses negate the need for a separate external dose measurement, while calculating the sample age and the external dose rate experienced by the tooth. Failing that, modelling the sedimentary dose rates using time-averaged total external dose calculations becomes necessary. These principles are illustrated using teeth from the australopithecine sites Sterkfontein and Swartkrans, South Africa.

  6. Evidence for large-scale reworking of Campanian sediments into the Upper Maastrichtian Peedee formation at Burches Ferry, South Carolina

    USGS Publications Warehouse

    ,; Christopher, R.A.; Prowell, D.C.

    2002-01-01

    A 44-ft-deep corehole (FLO-311) was drilled at Burches Ferry, Florence County, S.C., in order to document the lithologic and paleontologic characteristics of the boundary between the upper Campanian Donoho Creek Formation and the upper Maastrichtian Peedee Formation. Palynomorph and calcareous nannofossil data provide detailed age control for these sediments. Examination of calcareous nannofossil assemblages shows that sediments from the type locality of the Peedee Formation consist largely of reworked Campanian materials. Robust Campanian species such as Reinhardtites anthophorus, Reinhardtites levis, and Stoverius asymmetricus commonly are found reworked into the Maastrichtian Peedee Formation in its entirety. Therefore, identification of lower upper Maastrichtian sediments is based on the presence of background assemblages rather than on the more traditional marker species. The presence of species restricted to the latest Campanian at the Donoho Creek-Peedee contact in outcrop indicates that the entire sedimentary package represented by calcareous nannofossil Zones CC23 and CC24 has been removed.

  7. A mid to late Holocene history of floodplain and terrace reworking along the middle Delaware River valley, USA

    NASA Astrophysics Data System (ADS)

    Stinchcomb, Gary E.; Driese, Steven G.; Nordt, Lee C.; Allen, Peter M.

    2012-10-01

    This study tests and refines the traditional floodplain development model for the partly confined middle Delaware River valley, which has shown that the main channel was relatively stable and flanked by a 6000-8000 year old, vertically accreting alluvial terrace. The Holocene alluvial processes and history presented here in 6 fluvial phases were reconstructed using morphostratigraphy, 36 profile descriptions, 332 grain size analyses, and 82 14C ages from soil trenches, auger borings, and archaeological excavations. Fluvial phases I-III largely validate previous reconstructions showing a late Pleistocene (I: > 10.7 ka) braided stream transition into an early Holocene wandering stream with prolonged floodplain stability (II: 10.7-8 ka), followed by early-middle Holocene erosion and then deposition (III: 8-5 ka). The early and middle Holocene changes in alluvial stratigraphy and sedimentology broadly correlate with climatically derived Holocene subdivisions, suggesting climate change partly controls alluvial response along the middle Delaware River valley. This study documents for the first time a middle Holocene episode of channel incision occurring sometime between 6.0 and 5.0 ka. Although the results reconfirm that the majority of alluvial landforms are composed of vertical accretion deposits, we present here new evidence of oblique, abandoned channel, and lateral accretion deposits inset to similar landforms with different formation histories (i.e., polycyclic terrace development), depicting a river valley that has experienced floodplain and terrace reworking. The majority of floodplain and terrace reworking occurs during the late-middle and late Holocene phases IV-VI (5.5-0 ka), following the middle Holocene incision event. These phases demonstrate floodplain reworking processes in the form of channel abandonment, stripping, flood channeling, and convex bank erosion. The subsequent space filled rapidly with evidence of multistory soil formation, and eventually

  8. Left Behind: Effects of marine reworking and sea-level rise on deltas of the 21st century (Invited)

    NASA Astrophysics Data System (ADS)

    Ashton, A. D.; Nienhuis, J.; Ortiz, A. C.; Lorenzo Trueba, J.; Giosan, L.

    2013-12-01

    The 21st century will represent a time of punctuated change for the morphology of the world's deltas as they face the doubled-edged impacts of sediment reduction during reservoir infilling and submergence by rising sea levels. This research focuses on the controls on the evolution of deltas strongly affected by marine processes, namely wind waves, with a particular emphasis on reworking. Our objective is to apply process-based quantitative means to advance our observational knowledge of how changes in sediment supply and accommodation growth through sea-level rise manifest through delta reworking and the delta cycle. Building upon previous research highlighting how the angle of approaching waves can leave a fingerprint on a delta's shape, we investigate how the coastal conditions prior to sediment cessation can be used to predict the morphologic shape of the ensuing reworked shore along and adjacent to the former delta, including the potential for forming spits and other features indicative of lobe abandonment. In general, reworking results in rapid retreat near the mouth, but tends to be mass conservative, with eroded shoreface-compatible sediment deposited distally along the shoreline. Sediment cessation stops growth, but does not necessarily mean a delta plain will shrink. This marine reworking can be better understood using analogues of wave-influenced delta lobes that have been subjected to large-scale avulsions over the late Holocene, such as the Ebro, Danube, and Volta deltas. While the effects of sediment reduction will tend to be focused around active river mouths, a rising sea will, in a manner, 'sink all coasts'. Although models of stratigraphic delta evolution typically focus on the active depositional phase of profile evolution, with the wave-affected shoreface acting as a conduit of sediment basinwards, passive coasts demonstrate that coastal systems can remain intact during rising sea level and without sediment sources. As such, passive margin

  9. Reworking of structural inheritance at strike-slip restraining-bends: templates from sandbox analogue models

    NASA Astrophysics Data System (ADS)

    Nestola, Yago; Storti, Fabrizio; Cavozzi, Cristian; Magistroni, Corrado; Meda, Marco; Piero Righetti, Fabrizio

    2016-04-01

    Structural inheritance plays a fundamental role during crustal deformation because pre-existing fault and shear zones typically provide weakness zone suitable to fail again when affected by a new regional stress field. Re-activation of structural inheritance is expected to unavoidably increase the complexity of structural architectures, whose geometric and kinematic patterns can significantly deviate from what expected in newly deformed crustal sectors. Availability of templates from analogue models can provide a very effective tool to help unraveling such a structural complexity. For this purpose, we simulated the reworking of a set of basement hosted pre-existing fault zones at strike-slip restraining fault bends. In the models, the mechanical stratigraphy consists of a basement, made of a mixture of dry kaolin and sand to slightly increase cohesion, and a sedimentary cover made by pure dry sand. Inherited fault zones are confined to the basement and coated by a thin veneer of silicone putty. In the experimental programme, the geometry of the left-lateral restraining bend is maintained the same, with a bending angle of 30° of the restraining fault segment. The strike of the inherited fault zones, measured counterclockwise with respect to that of the master strike-slip fault zone outside the restraining bend, was 0°, 30°, and 60° in different experiments, respectively. An end member experiment without inheritance was also run for comparison. Our experimental results show that the angle that the inherited fault zones make with the restraining bend plays a fundamental role in governing the deformation pattern. When structural inheritance is near parallel to the master strike-slip fault zone, synthetic shears form and severely compartmentalize the transpressional pop-up anticline growing on top of the restraining bend. Fault-bounded blocks undergo sinistral escape during transpression. On the other hand, when structural inheritance makes a high angle to the

  10. Reworked planktonic Foraminifera from the Late Rupelian of the southern Upper Rhine Graben and their palaeogeographic and biostratigraphic implications

    NASA Astrophysics Data System (ADS)

    Pirkenseer, C.; Spezzaferri, S.; Berger, J.-P.

    2009-04-01

    During the Late Rupelian the widespread second transgression (corresponding to international Ru2-3 transgressions; BERGER et al. 2005) affected the whole Upper Rhine Graben basin and led to the deposition of the several hundred meters thick marine "Série grise". An abrupt transition (erosion surface) between the uppermost "Série grise" and Niederroedern Formation indicates the change to fluviatile and lacustrine conditions throughout the basin close to the Late Rupelian / Early Chattian boundary. Abundant reworked Middle to Late Cretaceous (e.g., Marginotruncana pseudolinneiana) and Late Paleocene to Late Eocene (e.g., Acarinina bullbrooki, Morozovella subbotinae, Turborotalia cocoaensis) ranging planktonic Foraminifera occur in the "Série Grise" and equivalent lithological units of the Upper Rhine Graben and the Mainz Basin (e.g., FISCHER 1965, PIRKENSEER 2007, SCHÄFER & KUHN 2004). At least Late Cretaceous, Ypresian, Lutetian and Priabonian ages of source sediments are indicated by the overlapping biostratigraphic ranges of the reworked specimens. Abundant reworked material first appears in the lower "Couches à Mélettes" and reaches its acme in the increasingly "Marnes à Cyrènes" (terminal "Série grise"). Only sparse records are documented from the subsequent terrestrial Niederroedern Formation. These reworking events are linked to intervals of increased clastic input throughout the "Série grise". The planktonic Foraminifera are proposed to be reworked from related alpine deposits (later Helvetikum?) via a northwards trending fluviatile system, as no autochthonous Cretaceous and Early to Middle Eocene marine sediments were deposited within the graben basin. Furthermore other possible source areas (e.g., Paris Basin) were either not connected to the Upper Rhine Graben or were not subject to erosion in the Late Rupelian. This accords with the proposition (ROUSSÉ 2006) of a vast northwards prograding delta-system that was located close to the southern

  11. Method for reworkable packaging of high speed, low electrical parasitic power electronics modules through gate drive integration

    DOEpatents

    Passmore, Brandon; Cole, Zach; Whitaker, Bret; Barkley, Adam; McNutt, Ty; Lostetter, Alexander

    2016-08-02

    A multichip power module directly connecting the busboard to a printed-circuit board that is attached to the power substrate enabling extremely low loop inductance for extreme environments such as high temperature operation. Wire bond interconnections are taught from the power die directly to the busboard further enabling enable low parasitic interconnections. Integration of on-board high frequency bus capacitors provide extremely low loop inductance. An extreme environment gate driver board allows close physical proximity of gate driver and power stage to reduce overall volume and reduce impedance in the control circuit. Parallel spring-loaded pin gate driver PCB connections allows a reliable and reworkable power module to gate driver interconnections.

  12. Bar deposition in glacial outburst floods: scaling, post-flood reworking, and implications for the geomorphological and sedimentary record

    NASA Astrophysics Data System (ADS)

    Marren, Philip

    2016-04-01

    The appearance of a flood deposit in the geomorphological and sedimentary record is a product of both the processes operating during the flood, and those that occur afterwards and which overprint the deposit with a record of 'normal' processes. This paper describes the creation and modification of jökulhlaup barforms in the Skeiðará river, relating the changes to post-flood fluvial processes and glacier retreat. Large compound bars formed from the amalgamation of unit bars up to 1.5 km long. Nearly half of the total discharge of the November 1996 jökulhlaup on Skeiðarársandur was discharged through the Skeiðará river. The flood deposits have been extensively reworked since, up until 2009 when the channel was abandoned, effectively leaving the Skeiðará as a terrace, when retreat of Skeiðarárjökull directed meltwater to the adjacent Gígjukvísl river system. Large compound bars formed in the flood channel, with their location governed by the macro-scale topography of the flood channel, and their size by upstream channel width in accordance with bar-scaling theory. Jökulhlaup bars are therefore scale invariant and formed in a similar fashion to braid bars in non-jökulhlaup braided rivers. Post-flood fragmentation and reworking of the bars consistently increased the length-width ratio of preserved bar fragments from approximately two and one half to over five. When combined with earlier work on the Skeiðará jökulhlaup bars, and studies of jökulhlaup deposits elsewhere on Skeiðarársandur these observations increase our understanding of the preservation potential and final form of jökulhlaup deposits and provide the basis for an improved model for the recognition of jökulhlaup deposits in the geomorphological and sedimentary record.

  13. Spatial and Temporal Variations of the K/T Boundary Record: Implications Concerning Possible Megaseiche in the Reworking Processes

    NASA Astrophysics Data System (ADS)

    Maurrasse, F. J.; Lamolda, M. A.

    2004-05-01

    Major physical disruptions characterize the sedimentary record of the K/T boundary (KTB) layer from different sites in the Southern Peninsula of Haiti as well as in diverse areas of the world. These disturbances are most important within the vicinity of the crater at Chicxulub, Yucatan, Mexico, and 65 million years ago that can be chronologically correlated with the bolide impact postulated by Alvarez et al (1981). At all sites the KTB layer shows spatial and temporal differences even within short distances, and the complexity of its characteristic signals includes serious micropaleontological inconsistencies with mixed biotic assemblages that perpetuate divergence of interpretations, thereby they raise doubts on the timing and real causal mechanisms of the biotic turnover that characterizes the boundary. Indeed, often the biostratigraphic signals are difficult to resolve because of hiatuses, or sediments are highly reworked, and distinct taxonomic successions are not clearly defined. Well defined as well as cryptic primary sedimentary structures within the boundary layer are constant at all outcrops, and they indicate complex, multiphase, subaqueous flow processes that affected sedimentation of the KTB layer at different times. The structures are known to characterize oscillatory wave processes that affect cohesionless sediments, and such water motion is only known to be associated with seiche as a modern analog that may have generated the amalgamation recorded at the KTB layer. We believe that "Megaseiche" associated with the KT impact event and its subsequent effects provides a plausible unifying mechanism to explain how various levels of the water column in different large basins can oscillate to develop the structures observed. Because of the magnitude of the bolide impact that generated initial tsunamis and large seismic waves worldwide, megaseiches of different frequencies and nodal modes must have developed in the oceans worldwide to leave different

  14. LA-ICP-MS analysis of isolated phosphatic grains indicates selective rare earth element enrichment during reworking and transport processes

    NASA Astrophysics Data System (ADS)

    Auer, Gerald; Reuter, Markus; Hauzenberger, Christoph A.; Piller, Werner E.

    2016-04-01

    water chemistry under certain well constrained circumstances of primary authigenesis. Are these conditions not met, REE patterns are more likely to reflect complex enrichment processes that likely already started to occur during reworking over geologically relatively short time frames. Similarities in the REE patterns of clearly detrital and biogenic phosphate further suggest that the often observed 'hat-shaped' pattern in biogenic phosphates can easily result from increased middle REE (Neodymium to Holmium) scavenging during taphonomic processes prior to final deposition. Finally, cluster analysis coupled with sedimentological considerations proved a valuable tool for the characterization of REE patterns of phosphates in terms of their formation conditions and depositional history, such as the distinction of phosphates formed in situ from reworked and transported phosphate grains.

  15. Producer-retailer integrated EMQ system with machine breakdown, rework failures, and a discontinuous inventory issuing policy.

    PubMed

    Chiu, Singa Wang; Chen, Shin-Wei; Chiu, Yuan-Shyi Peter; Li, Ting-Wei

    2016-01-01

    This study develops two extended economic manufacturing quantity (EMQ)-based models with a discontinuous product issuing policy, random machine breakdown, and rework failures. Various real conditions in production processes, end-product delivery, and intra-supply chains such as a producer-retailer integrated scheme are examined. The first model incorporates a discontinuous multi-delivery policy into a prior work (Chiu et al. in Proc Inst Mech Eng B J Eng 223:183-194, 2009) in lieu of their continuous policy. Such an enhanced model can address situations in supply chain environments, where finished products are transported to outside retail stores (or customers). The second model further combines retailer's stock holding costs into the first model. This extended EMQ model is applicable in situations in present-day manufacturing firms where finished products are distributed to company's own retail stores (or regional sales offices) and stocked there for sale. Two aforementioned extended EMQ models are investigated, respectively. Mathematical modeling along with iterative algorithms are employed to derive the optimal production run times that minimize the expected total system costs, including the costs incurred in production units, transportation, and retail stores, for these integrated EMQ systems. Numerical examples are provided to demonstrate the practical application of the research results. PMID:27065179

  16. Lithospheric reworking at the Proterozoic-Phanerozoic transition of Australia imaged using AusLAMP Magnetotelluric data

    NASA Astrophysics Data System (ADS)

    Robertson, Kate; Heinson, Graham; Thiel, Stephan

    2016-10-01

    Seventy-four stations from the long-period Australia-wide AusLAMP (Australian Lithospheric Architecture Magnetotelluric Project) dataset were used to image the electrical resistivity beneath the Neoproterozoic Ikara-Flinders Ranges and adjacent Palaeo-Mesoproterozoic Curnamona Province. Results from 3D inversions using ModEM software show a relatively resistive Ikara-Flinders Ranges, with two parallel arcuate conductors at 20 to 80 km depth in the Nackara Arc. There is a good correlation of diamondiferous kimberlites occurring over conductors, which we interpret as evidence for these conductors to be residing on large lithospheric structures that have been conduits for partial melt and volatile movement in the Jurassic. The Curnamona Province is remarkably conductive for a region that is thought to have a cratonic core, with Delamerian reworking only at its edges. The conductor covers most of the province at depths of 10-40 km, and its presence at lower crustal depths suggests that conductive sediments can not entirely explain it. Fluids associated with subduction may have pervasively modified the crust in the past, resulting in an enrichment of carbon, enhancing the conductivity. Additionally, we conclude that the notion of a single continuous arcuate Flinders Conductivity Anomaly is unlikely and that the anomalous response observed is instead a result of the combined response of three separate anomalies; the Curnamona Province Conductor and the two Nackara Arc Conductors.

  17. Producer-retailer integrated EMQ system with machine breakdown, rework failures, and a discontinuous inventory issuing policy.

    PubMed

    Chiu, Singa Wang; Chen, Shin-Wei; Chiu, Yuan-Shyi Peter; Li, Ting-Wei

    2016-01-01

    This study develops two extended economic manufacturing quantity (EMQ)-based models with a discontinuous product issuing policy, random machine breakdown, and rework failures. Various real conditions in production processes, end-product delivery, and intra-supply chains such as a producer-retailer integrated scheme are examined. The first model incorporates a discontinuous multi-delivery policy into a prior work (Chiu et al. in Proc Inst Mech Eng B J Eng 223:183-194, 2009) in lieu of their continuous policy. Such an enhanced model can address situations in supply chain environments, where finished products are transported to outside retail stores (or customers). The second model further combines retailer's stock holding costs into the first model. This extended EMQ model is applicable in situations in present-day manufacturing firms where finished products are distributed to company's own retail stores (or regional sales offices) and stocked there for sale. Two aforementioned extended EMQ models are investigated, respectively. Mathematical modeling along with iterative algorithms are employed to derive the optimal production run times that minimize the expected total system costs, including the costs incurred in production units, transportation, and retail stores, for these integrated EMQ systems. Numerical examples are provided to demonstrate the practical application of the research results.

  18. Google Wave: Collaboration Reworked

    ERIC Educational Resources Information Center

    Rethlefsen, Melissa L.

    2010-01-01

    Over the past several years, Internet users have become accustomed to Web 2.0 and cloud computing-style applications. It's commonplace and even intuitive to drag and drop gadgets on personalized start pages, to comment on a Facebook post without reloading the page, and to compose and save documents through a web browser. The web paradigm has…

  19. Rethink, Rework, Recycle.

    ERIC Educational Resources Information Center

    Wrhen, Linda; DiSpezio, Michael A.

    1991-01-01

    Information about the recycling and reuse of plastics, aluminum, steel, glass, and newspapers is presented. The phases of recycling are described. An activity that allows students to separate recyclable materials is included. The objectives, a list of needed materials, and procedure are provided. (KR)

  20. Surficial geology of the Kennebec River paleodelta: A product of Pleistocene deposition, modification by Holocene transgression, and modern sediment reworking

    SciTech Connect

    Barnhardt, W.A.; Belknap, D.F. . Dept. of Geolofical Sciences); Kelley, J.T.; Dickson, S.M. )

    1993-03-01

    Large sandy lithosomes, interpreted as paleodeltas, are reported seaward of several major rivers entering the western Gulf of Maine. The lobate, smooth-topped morphology of the Kennebec River paleodelta smothers high-relief bedrock ridges on the inner continental shelf of south-central Maine. Since 1991, 488 km of side-scan sonar records and 116 km of high-resolution seismic reflection profiles were collected in this recently glaciated region. Coupled with 120 previously collected bottom samples and observations from numerous submersible dives, these data were used to map the surficial geology of the area and elucidate its relationship to the late Quaternary stratigraphy. The Kennebec paleodelta formed approximately 12--10 ka when sea level fell to a depth of 60 m and abundant sandy material was delivered to the lowstand shoreline. Subsequent marine transgression with reduced sediment input greatly modified the former delta, creating a patchwork of palimpsest deltaic and relict shoreline features overprinted by younger coastal and shelf processes. As barrier beach and estuarine systems transgressed from the lowstand shoreline to their position at the present coast, shoreface erosion exhumed underlying units, exposing a variety of textural facies across the delta surface. In adjacent areas 15--30 m deep and along much of the seaward margin, elongate bands of rippled gravel are oriented perpendicular to shore, indicating modern sediment reworking and cross-shelf transport. These rippled scour depressions often coincide with older glacial marine sediments cropping out on the surface. Vibracores and current meter measurements collected in 1992 will help resolve many questions concerning the past evolution of the paleodelta and the effects of modern processes on the distribution of surficial sediments.

  1. Sediment provenance, reworking and transport processes in the Indus River by U-Pb dating of detrital zircon grains

    NASA Astrophysics Data System (ADS)

    Alizai, Anwar; Carter, Andrew; Clift, Peter D.; VanLaningham, Sam; Williams, Jeremy C.; Kumar, Ravindra

    2011-03-01

    We present new major and trace element data, together with U-Pb ages for zircon sand grains from the major tributaries of the Indus River, as well as the adjacent Ghaggar and Yamuna Rivers and from bedrocks within the Sutlej Valley, in order to constrain the origin of the sediment reaching the Arabian Sea. Zircon grains from the upper Indus are generally younger than 200 Ma and contrast with those from the eastern tributaries eroded from Himalayan sources. Grains younger than 15 Ma, which typify the Nanga Parbat Massif, comprise no more than 1-2% of the total, even in the upper Indus, showing that this terrain is not a major sediment producer, in contrast with the Namche Barwe Massif in the eastern Himalayan syntaxis. The Sutlej and Yamuna Rivers in particular are very rich in Lesser Himalayan-derived 1500-2300 Ma zircons, while the Chenab is dominated by 750-1250 Ma zircons, mostly eroded from the Greater Himalaya. The upper Indus, Chenab and Ravi yield zircon populations broadly consistent with the outcrop areas, but the Jhelum and the Sutlej contain many more 1500-2300 Ma zircons than would be predicted from the area of Lesser Himalayan rock within their drainages. A significant population of grains younger than 200 Ma in the sands of the Thar Desert indicates preferential eolian, monsoon-related transport from the Indus lower reaches, rather than reworking from the local rivers. Modelling of observed zircon ages close to the delta contrasts with modern water discharge. The delta is rich in zircons dating 1500-2300 Ma, while discharge from modern rivers carrying such grains is low. The modest size of the Sutlej, the richest source of these materials in the modern system, raises the possibility that the compositionally similar Yamuna used to flow westwards in the recent past. Our data indicate a non-steady state river with zircon transport times of 5-10 k.y. inferred from earlier zircon dating of delta sands. The modern delta zircons image an earlier, likely

  2. Late Quaternary aeolian sand deposition sustained by fluvial reworking and sediment supply in the Hexi Corridor - An example from northern Chinese drylands

    NASA Astrophysics Data System (ADS)

    Nottebaum, Veit; Lehmkuhl, Frank; Stauch, Georg; Lu, Huayu; Yi, Shuangwen

    2015-12-01

    Aeolian deposits are frequently used for palaeoenvironmental change studies. Their formation depends on an array of requirements: the supply of material suitable for aeolian transport and favorable conditions of sediment availability and wind strength. In order to infer palaeoenvironmental information from aeolian sand deposits these factors need to be carefully evaluated. We present a study from northern Chinese Hexi Corridor, based on 11 optically stimulated luminescence (OSL) dated sediment sections. These represent interchanging aeolian and alluvial deposits under gravel surfaces and aeolian sand in dune fields interrupted by interdunal flood deposits. Investigations in two subareas reveal contrasting geomorphologic and sedimentary histories: (1) sediment deposition during the Pleistocene-Holocene transition (~ 12 ka) followed by deflation during the Holocene and (2) frequent sediment recycling revealed by a wide spectrum of ages throughout the Holocene. The late glacial sediment pulse recorded in the western Hexi Corridor is attributed to high sediment supply, generated by efficient (peri-)glacial sediment production during glacial times in the adjacent Qilian Shan (< 5700 m asl) and a moisture increase inducing the reworking of those (glacio-)fluvial deposits during the Pleistocene-Holocene transition. The absence of a powerful reworking agent preserved these late glacial deposits in the western Hexi Corridor in contrast to moister eastern parts where Holocene sediment reworking prevailed. Geomorphological and hydrological preconditions of the subareas are discussed and reveal the controlling influence of fluvial processes on sand supply for the aeolian system. While a perennial drainage is missing in the drier western part, the Hei River drainage is fed by higher monsoonal precipitation in the central Hexi Corridor. It maintains a sediment recycling system and has ensured a sufficient sediment supply throughout the Holocene. The study promotes closer

  3. The U-Pb, Hf and O isotopic record of ancient detrital zircons in Zimbabwean sediments - formation, reworking and nature of early Archaean crust

    NASA Astrophysics Data System (ADS)

    Bolhar, Robert; Hofmann, Axel; Kemp, Anthony I. S.; Whitehouse, Martin J.; Wind, Sandra; Feng, Yuexing

    2014-05-01

    Hafnium and oxygen isotopic compositions measured in-situ on U-Pb dated zircon from different Archaean sedimentary successions belonging to the 2.9-2.8 Ga Belingwean/Bulawayan Groups and undated Sebakwian Group are presented to better define the crustal evolution of the Zimbabwe Craton prior to 3.0 Ga. Textural and compositional criteria were employed to minimize effects arising from Pb loss, metamorphic overprinting and interaction with low temperature fluids. 207Pb/206Pb age spectra (concordance > 90%) reveal prominent peaks at 3.8, 3.6, 3.5, and 3.35 Ga, corresponding to documented geological events both globally and within the Zimbabwe craton. O isotope compositions of ~ 4 - 10 opoint to both derivation from magmas in equilibrium with mantle and the assimilation of supracrustal material or interaction with metamorphic fluids. In ɛHf-time space, 3.8-3.6 Ga grains define an array consistent with derivation from a mafic to intermediate source reservoir (Lu/Hf ~0.015) that separated from chondritic mantle at ~ 3.9 Ga. Crustal domains formed after 3.6 Ga depict a more complex evolution, involving contribution from juvenile mantle sources and reworking of pre-existing crust. Importantly, initial Hf isotopic compositions document a protracted history of remelting, without evidence for significant mantle depletion prior to 3.35 Ga. This suggests that production of earliest crust in the Zimbabwe Craton did not cause complementary enriched and depleted reservoirs, possibly because heterogeneous mantle was effectively remixed by rapid convection due to higher temperatures in the early Archaean or the volume of crust was too small in volume to influence the isotopic mantle evolution. Similar Hf-O-time relationships observed in southern West Greenland were used as a basis to propose a transition in geodynamics 3.2 Ga ago. The absence of detrital zircons with crystallization ages > 3.8 Ga, along with a simple ɛHf-time array consistent with reworking of a mafic protolith

  4. Growth of continental crust and its episodic reworking over >800 Ma: evidence from Hf-Nd isotope data on the Pietersburg block (South Africa)

    NASA Astrophysics Data System (ADS)

    Laurent, Oscar; Zeh, Armin; Moyen, Jean-François; Doucelance, Régis; Martin, Hervé

    2014-05-01

    The formation and evolution of the continental crust during the Precambrian, and in particular during the Archaean eon (4.0-2.5 Ga), is still a matter of debate. In particular, it is not yet clear in which tectonic environment the genesis of crust took place and how the large volume of granitoid rocks that form ~70% of the Archaean crust were extracted from the mantle. Many studies highlighted that radiogenic isotope systems, especially Lu-Hf and Sm-Nd, are powerful tools to unravel the respective extent of crustal growth and recycling in Archaean terranes. This work presents coupled Hf and Nd isotope data (analyzed both in situ in accessory minerals and in whole rock samples) of Meso- to Neoarchaean granitoids, applied to unravel the processes of crust formation and evolution of the Pietersburg crustal block in South Africa. This crustal segment, the northermost one of the Archaean Kaapvaal Craton, is separated from older crust (3.65-3.10 Ga) by a large-scale suture zone, and the processes related to amalgamation of both blocks and their subsequent evolution are still unclear. The Pietersburg block is made up of a wide range of Archaean granitoid rocks, including tonalite-trondhjemite-granodiorite (TTG) series, high-K monzogranites as well as (grano)diorites belonging to the so-called "sanukitoid" group [1], all intruded by late Paleoproterozoic alkaline complexes. Age determinations highlighted two stages of granitoid formation: (1) TTG magmatism took place episodically over >400 Ma between 3.34 and 2.89 Ga, with a major pulse at 2.97-2.90 Ga; while (2) all the other (high-K) granitoid types emplaced subsequently between 2.84 and 2.69 Ga before a long magmatic shutdown until the intrusion of alkaline complexes at ~2.00 Ga [2-3]. Isotope systematics reveal that these two stages are related to juvenile crust formation and crust reworking, respectively. Indeed, all Hf-Nd isotope data from TTG gneisses are suprachondritic, pointing to a juvenile origin and precluding

  5. Relating geodynamic setting to periods of crustal growth and reworking as illustrated by the Phanerozoic granitoids of the Eastern Cordillera of South Peru

    NASA Astrophysics Data System (ADS)

    Reitsma, M.; Schaltegger, U.; Spikings, R.; Ulianov, A.; Gerdes, A.; Chiaradia, M.

    2012-04-01

    The granitoids that form the backbone of the Eastern Cordillera of Peru between 12 and 14°S, are the ideal material for a case study to relate geodynamic setting to crustal growth over the period of a Wilson cycle. Extension related plutons were emplaced in the back-arc region of the Western Gondwana margin during the Ordovician, Permo-Carboniferous, Triassic and Early Jurassic. With the onset of the Andean cycle in the Middle Jurassic the South American margin was under compression, the plutonic record of this period is in the study area restricted to the Eocene and Miocene. The Ordovician to Triassic back-arc related plutons share many geochemical characteristics that point to dominant crustal reworking as the main process during their formation. These are 1) their mainly felsic and peraluminous nature; 2) the similarity of whole rock REE and trace element compositions compared to those of average continental crust; 3) the presence of negative Nb-Ta anomalies only in the more evolved samples which indicates that these excursions have been obtained by crustal melting rather than from a slab fluid and 4) the presence of significant amounts of xenocrystic cores in zircon. According to the literature the last major episode of juvenile crust formation was during the Grenvillian age Sunsas event (1.2 - 0.9 Ga) related to the collision of Laurentia and south-western Amazonia during the assembly of Rodinia. Hf-isotopes on zircons from the Ordovician, Permo-Carboniferous and Triassic plutons confirm their origin as mainly crustal melts generated by reworking of Sunsas-age crust. Under these geodynamic conditions it is mainly the crust that melts due to an elevated geothermal gradient as the result of crustal thinning. However, data from Jurassic nepheline bearing syenite and Eocene hornblende diorite and monzonite have epsilon Hfi values well above those of Sunsas crust, indicating an important mantle component in the melts. The Jurassic geodynamic setting is interpreted

  6. Reworked pre-Grenville crust and timing of Grenville orogenesis in the southeastern Llano Uplift, Texas: Results from U-Pb geochronometry

    SciTech Connect

    Reese, J.F.; Roback, R.C.; Walker, N.W. . Geological Sciences)

    1992-01-01

    Zircon geochronometry of metaigneous units in the southeastern Llano Uplift (1) show that 1355-1215 Ma rocks were tectonically reworked during the Grenville orogeny, (2) further constrain the timing of Grenville orogenesis along the southern margin of North America, and (3) necessitate revision of previously proposed stratigraphic and structural relations within the Llano Supergroup. Multigrain, abraded zircon fractions from a sample of quartzofeldspathic Valley Spring Gneiss (VSG) define a discordia trajectory with an upper intercept of 1355 [plus minus] 3 Ma, interpreted as the igneous crystallization age of the protolith. This age is the oldest thus far documented for Llano Supergroup protoliths and is substantially older than a recently reported age (1232 [plus minus]4 Ma) from a different part of the VSG. The lithologic and chronometric similarities of the old VSG to rocks to the Mid-continent Granite-Rhyolite terrane raise the possibility of genetic relations between these units. Thus components of the VSG are tentatively interpreted to represent a deformed and metamorphosed part of the southernmost Mid-Continent Granite-Rhyolite terrane. Alternatively, this rock could be part of an ensialic arc built upon the margin of southern North America and later deformed during the Grenville orogeny. Analyses from four abraded zircon fractions from a quartzofeldspathic gneiss in the structurally overlying Packsaddle Schist yield an upper intercept of 1215 [plus minus] 3 Ma, interpreted as the igneous protolith crystallization age. This age is the youngest yet determined for a polydeformed metamorphic rock in the Llano Uplift and more tightly brackets the timing of Grenville deformation in the southeastern Llano Uplift to post-1215 Ma and pre-1098 Ma.

  7. Burial of Emperor Augustus' villa at Somma Vesuviana (Italy) by post-79 AD Vesuvius eruptions and reworked (lahars and stream flow) deposits

    NASA Astrophysics Data System (ADS)

    Perrotta, Annamaria; Scarpati, Claudio; Luongo, Giuseppe; Aoyagi, Masanori

    2006-11-01

    A new archaeological site of Roman Age has been recently found engulfed in the products of Vesuvius activity at Somma Vesuviana, on the northern flank of the Somma-Vesuvius, 5 km from the vent. A 9 m deep, 30 by 35 m trench has revealed a monumental edifice tentatively attributed to the Emperor Augustus. Different than Pompeii and Herculaneum sites which were completely buried in the catastrophic eruption of 79 AD, this huge roman villa survived the effects of the 79 AD plinian eruption as suggested by stratigraphic and geochronologic data. It was later completely engulfed in the products of numerous explosive volcanic eruptions ranging from 472 AD to 1631 AD, which were separated by reworked material and paleosols. The exposed burial sequence is comprised of seven stratigraphic units. Four units are composed exclusively of pyroclastic products each emplaced during a unique explosive event. Two units are composed of volcaniclastic material (stream flow and lahars) emplaced during quiescent periods of the volcano. Finally, one unit is composed of both pyroclastic and volcaniclastic deposits. One of the more relevant volcanological results of this study is the detailed reconstruction of the destructive events that buried the Emperor Augustus' villa. Stratigraphic evidence shows the absence of any deposit associated with the 79 AD eruption at this site and that the building was extensively damaged (sacked) before it was engulfed by the products of subsequent volcanic eruptions and lahars. The products of the 472 AD eruption lie directly on the roman structures. They consist of scoria fall layers intercalated with massive and stratified pyroclastic density current deposits that caused limited damage to the structure. The impact on the building of penecontemporaneous lahars was more important; these caused the collapse of some structures. The remaining part of the building was subsequently entombed by the products of explosive eruptions (e.g. 512/536 eruption, 1631

  8. Microbial Reworking Organic Matter in the Hauraki Gulf, New Zealand: Evidence from the Stable Isotopic Composition of Sedimentary D- and L-Amino Acids

    NASA Astrophysics Data System (ADS)

    Uhle, M. E.; Sikes, E. L.; Nodder, S. D.; Hage, M. M.; Howard, M. E.

    2004-05-01

    to be a good indicator of microbial reworking of the sediments.

  9. Debris Flow Initiation and Fan Reworking in the Green River Canyons of the Eastern Uinta Mountains: The Limited Role of Wildfire and the Significance of Low-Magnitude Floods

    NASA Astrophysics Data System (ADS)

    Larsen, I. J.; Schmidt, J. C.; Pederson, J. L.; Martin, J. A.

    2003-12-01

    The primary determinant on channel organization of the Green River in the canyons of the eastern Uinta Mountains is the occurrence and frequency of debris flows in tributary watersheds. The frequency of these debris flows appears to be related to climatic factors, not factors related to wildfire. Debris flows in the eastern Uinta Mountains occur by a process known as the firehose effect, wherein overland flow generated on bedrock slopes cascades down steep cliffs and saturates and impacts colluvium stored in bedrock hollows. The colluvium fails, initiating debris flows that travel downslope to the Green River. The dry climate and high-strength bedrock cause hillslopes to be weathering-limited, prohibiting the formation of extensive regolith and vegetative cover. This reduces the degree vegetation regulates geomorphic processes and, in turn, causes wildfire to have little influence on debris flow initiation; slight increases in watershed runoff do not appear to alter the likelihood of this process occurring. A secondary determinant on channel organization in debris fan-dominated canyons are the magnitude of mainstem discharges and the degree to which they rework debris flow deposits; in this case flows are regulated by Flaming Gorge Dam. Substantial reworking of debris flow deposits can be accomplished by mainstem floods with discharges greater than 75%\\ of the pre-dam two year flood, whereas floods with magnitudes less than 40%\\ of the pre-dam 2-year flood do little reworking.

  10. Metamorphic and age constraints on tectono-thermal reworking in the western H.U. Sverdrupfjella: A new crustal evolution model for Western Dronning Maud Land, Antarctica

    NASA Astrophysics Data System (ADS)

    Grosch, Eugene; Frimmel, Hartwig; Abu-Alam, Tamer; Košler, Jan

    2014-05-01

    -African thrust, which was subsequently reactivated during Gondwana break-up. These new results are integrated with published regional age (e.g. Frimmel, 2004) and geochemical (Grosch et al., 2007) data to propose a new geodynamic evolution model for Western Dronning Maud Land, with implications for Rodinia and Gondwana reconstructions. The revised Mesoproterozoic to Pan-African crustal evolution model for western Dronning Maud Land, proposes that the Maud Belt initially formed as a continental volcanic arc on the southeastern Grunehogna Craton margin, and not as an independent, Mesoproterozoic juvenile oceanic island arc. It follows that the PJD does not represent a Mesoproterozoic suture zone between a juvenile island arc and the Grunehogna Craton, but more likely a continental, Mesoproterozoic-Pan-African back-arc thrust zone. It is proposed herein, that large parts of the southeastern Kalahari-Grunehogna Craton margin (that included the Maud continental volcanic arc crust), experienced major tectonic reworking at eclogite to upper amphibolite facies conditions during Gondwana assembly. As such the new data from Western Dronning Maud Land has important implications for the extension of the Mozambique Belt into Antarctica and the location of the main suture zone between East and West Gondwana.

  11. Integrated Nd isotopic and U-Pb detrital zircon systematics of clastic sedimentary rocks from the Slave Province, Canada: evidence for extensive crustal reworking in the early- to mid-Archean

    NASA Astrophysics Data System (ADS)

    Yamashita, Katsuyuki; Creaser, Robert A.; Villeneuve, Mike E.

    2000-01-01

    A combined U-Pb geochronology and Nd isotopic analysis of clastic metasedimentary rocks from the Archean Slave Province, Northwest Territories, Canada is presented. A series of clastic sedimentary rocks with deposition age of ˜3.13 Ga to ˜2.58 Ga was collected from the west-central Slave Province. These samples include conglomerates as well as finer sedimentary rocks such as greywacke, arkose and quartzite. Although it is generally agreed that the Nd model age ( TDM) of clastic sedimentary rocks represents the average sedimentary provenance age, TDM of samples studied here is generally older than the average U-Pb age of detrital zircons extracted from the same sample. Rather, there seems to be a better ˜1:1 relationship between the TDM and U-Pb age of the oldest zircon from each sample. A simple model relationship between U-Pb geochronology and TDM suggests that such correlation is a result of Archean crustal evolution of the Slave Province being dominated by crustal reworking (i.e. intracrustal processes) rather than addition of juvenile materials from the mantle. One exception is the period between ˜3.1 and ˜3.2 Ga, during which period a significant portion of detrital zircons have U-Pb ages exceeding the TDM, indicating a large input of juvenile material and/or decreasing level of crustal reworking. An alternative explanation for the U-Pb vs. TDM trend may be a mixing of older mafic juvenile crust (containing no zircon) and younger felsic juvenile crust. However, the general lack of extensive pre-2.8 Ga mafic crust in the Slave Province makes this scenario unlikely. The results of this study cannot constrain the change in the volume of continental crust at any given period of time, since the addition of juvenile crust may always be counterbalanced by recycling of crustal material back into the mantle. However, a dominance of crustal reworking during the early- to mid-Archean strongly implies that a large part of ancient crust was lost during the younger

  12. 7 CFR 29.3542 - Rework.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign... separated by sorting; (b) Tobacco which contains an abnormally large quantity of foreign matter or...

  13. 7 CFR 29.3542 - Rework.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign... separated by sorting; (b) Tobacco which contains an abnormally large quantity of foreign matter or...

  14. 7 CFR 29.3542 - Rework.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign... separated by sorting; (b) Tobacco which contains an abnormally large quantity of foreign matter or...

  15. 7 CFR 29.3542 - Rework.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign... separated by sorting; (b) Tobacco which contains an abnormally large quantity of foreign matter or...

  16. 7 CFR 29.3542 - Rework.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... INSPECTION Standards Official Standard Grades for Dark Air-Cured Tobacco (u.s. Types 35, 36, 37 and Foreign... separated by sorting; (b) Tobacco which contains an abnormally large quantity of foreign matter or...

  17. Robust, Rework-able Thermal Electronic Packaging: Applications in High Power TR Modules for Space

    NASA Technical Reports Server (NTRS)

    Hoffman, James Patrick; Del Castillo, Linda; Hunter, Don; Miller, Jennifer

    2012-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires improvements in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and are now being implemented side-by-side with more standard technology typically used in flight hardware.

  18. Complete Alpine reworking of the northern Menderes Massif, western Turkey

    NASA Astrophysics Data System (ADS)

    Cenki-Tok, B.; Expert, M.; Işık, V.; Candan, O.; Monié, P.; Bruguier, O.

    2016-07-01

    This study focuses on the petrology, geochronology and thermochronology of metamorphic rocks within the northern Menderes Massif in western Turkey. Metasediments belonging to the cover series of the Massif record pervasive amphibolite-facies metamorphism culminating at ca. 625-670 °C and 7-9 kbars. U-Th-Pb in situ ages on monazite and allanite from these metapelites record crustal thickening and nappe stacking associated with the internal imbrication of the Anatolide-Taurides platform during the Eocene. In addition, new 39Ar/40Ar single muscovite grain analyses on deformed rocks were performed in three localities within the northern Menderes Massif and ages range from 19.8 to 25.5 Ma. These mylonites may be related to both well-known detachments, Simav to the north and Alaşehir to the south, which accommodate Oligo-Miocene exhumation of the Menderes core complex. U-Th-Pb data on monazite grains (22.2 ± 0.2 Ma) from migmatites emplaced within the Simav detachment confirm these ages.

  19. Reworking Industrial Models, Exploring Contemporary Ideas, and Fostering Teacher Leadership

    ERIC Educational Resources Information Center

    Steel, Christopher; Craig, Elizabeth

    2006-01-01

    If the culture of teaching is to change from one of isolation and professional limitations to one of collaboration and empowerment, administrators must change how they view and interact with teachers. Mr. Steel and Ms. Craig offer specific recommendations for how school leaders can support and facilitate teachers' growth. (Contains 9 endnotes.)

  20. Ancient impactor components preserved and reworked in martian regolith breccia Northwest Africa 7034

    NASA Astrophysics Data System (ADS)

    Goderis, Steven; Brandon, Alan D.; Mayer, Bernhard; Humayun, Munir

    2016-10-01

    Northwest Africa (NWA) 7034 and paired stones represent unique samples of martian polymict regolith breccia. Multiple breccia subsamples characterized in this work confirm highly siderophile element (HSE: Re, Os, Ir, Ru, Pt, Pd) contents that are consistently elevated (e.g., Os ∼9.3-18.4 ppb) above indigenous martian igneous rocks (mostly <5 ppb Os), equivalent to ∼3 wt% of admixed CI-type carbonaceous chondritic material, and occur in broadly chondrite-relative proportions. However, a protracted history of impactor component (metal and sulfide) breakdown and redistribution of the associated HSE has masked the original nature of the admixed meteorite signatures. The present-day 187Os/188Os ratios of 0.119-0.136 record a wider variation than observed for all major chondrite types. Combined with the measured 187Re/188Os ratios of 0.154-0.994, the range in Os isotope ratios indicates redistribution of Re and Os from originally chondritic components early in the history of the regolith commencing at ∼4.4 Ga. Superimposed recent Re mobility reflects exposure and weathering at or near the martian and terrestrial surfaces. Elevated Os concentrations (38.0 and 92.6 ppb Os), superchondritic Os/HSE ratios, and 187Os/188Os of 0.1171 and 0.1197 measured for two subsamples of the breccia suggest the redistribution of impactor material at ∼1.5-1.9 Ga, possibly overlapping with a (partial) resetting event at ∼1.4 Ga recorded by U-Pb isotope systematics in the breccia. Martian alteration of the originally chondritic HSE host phases, to form Os-Ir-rich nuggets and Ni-rich pyrite, implies the influence of potentially impact-driven hydrothermal systems. Multiple generations of impactor component admixture, redistribution, and alteration mark the formation and evolution of the martian regolith clasts and matrix of NWA 7034 and paired meteorites, from the pre-Noachian until impact ejection to Earth.

  1. Reworking therapeutic landscapes: the spatiality of an 'alternative' self-help group.

    PubMed

    Laws, Jennifer

    2009-12-01

    Since Gesler first introduced the concept in 1992, the language of 'therapeutic landscapes' has attained a core position in the toolkit of health/place studies. Whilst many authors using the term acknowledge that therapeutic landscapes are often also spaces of contestation, few if any have extended this to incorporate a serious critique of therapy itself. In this article, I use the case study of an 'alternative' psychiatric survivor (self-help) group in the north of England to attempt just this. Based on a ten month period of ethnography, I engage with the spaces - meeting places and venues - occupied by the group, focusing on the dilapidated and reputedly dangerous city park where the group hosts its most regular meetings. Three qualities of these spaces were found to be particularly embraced by the group: spaces of agency and appropriation; a space in the world; and a non-technical relation with space. The article uses these three themes to explore how the unconventional spaces of the group are not mere products of marginality but a serious aspect of mobilising the dissident and 'anti-psychiatric' recovery sought by its members. Through attending to what the survivors' found helpful in the park, a more sensitive rendition of 'anti-psychiatry' as it relates to the group is developed. The therapeutic landscapes framework as put forward by Gesler retains currency in highlighting the importance of place to the processes and identity of the group. However, it is also suggested that the 'dissident topophilias' of the survivors express a critique of current therapeutic landscapes thinking, challenging the supposition that it is the planned, the pleasant and the professional that provide the best backdrops for recovery.

  2. Photochemically reversible liquefaction and solidification of multiazobenzene sugar-alcohol derivatives and application to reworkable adhesives.

    PubMed

    Akiyama, Haruhisa; Kanazawa, Satoshi; Okuyama, Yoko; Yoshida, Masaru; Kihara, Hideyuki; Nagai, Hideki; Norikane, Yasuo; Azumi, Reiko

    2014-05-28

    Multiazobenzene compounds, hexakis-O-[4-(phenylazo)phenoxyalkylcarboxyl]-D-mannitols and hexakis-O-[4-(4-hexylphenylazo)phenoxyalkylcarboxyl]-D-mannitols, exhibit photochemically reversible liquefaction and solidification at room temperature. Their photochemical and thermal phase transitions were investigated in detail through thermal analysis, absorption spectroscopy, and dynamic viscoelasticity measurements, and were compared with those of other sugar-alcohol derivatives. Tensile shear strength tests were performed to determine the adhesions of the compounds sandwiched between two glass slides to determine whether the compounds were suitable for application as adhesives. The adhesions were varied by alternately irradiating the compounds with ultraviolet and visible light to photoinduce phase transitions. The azobenzene hexyl tails, lengths of the methylene spacers, and differences in the sugar-alcohol structures affected the photoresponsive properties of the compounds.

  3. The "Rebbe" Reworked: An Inquiry into the Persistence of Inherited Traditions of Teaching.

    ERIC Educational Resources Information Center

    Pomson, Alex

    2002-01-01

    Examines the strength of teaching archetypes, highlighting accounts from Jewish day school teachers about their lives and work to investigate the strength of traditional conceptions of teaching. Results illustrate how a teacher draws on a strong tradition of Jewish teaching even as she transforms her enactment of that tradition to accommodate new…

  4. The effect of rainfall events with changing frequency and magnitude on reworking conditions of proglacial moraines

    NASA Astrophysics Data System (ADS)

    Dusik, Jana-Marie; Heckmann, Tobias; Neugirg, Fabian; Hilger, Ludwig; Haas, Florian; Becht, Michael

    2014-05-01

    The consequences of the ongoing temperature rise in alpine regions force glaciers to rapid melting and thus new surfaces are exposed to generate numerous geomorphic processes. Steep Little Ice Age (LIA) moraines and other glacial depositional landforms contain huge masses of sediments, that are subject to progressive (re-)mobilization by gullying, slope wash, debris flows and other mass movements. The material is frequently re-deposited in secondary storage landforms; these storages themselves are then subject to depletion. Increased morphodynamics with a maximum shortly after deglaciation, and a slow decrease afterwards, are predicted by the conceptual model of paraglacial response. In addition to these "self-organising" changes following deglaciation, our study area has been experiencing changes in precipitation and (meltwater) discharge for decades; these climatic factors are known to influence morphodynamics, e.g. by triggering mass movements and by driving slope wash and fluvial erosion. While overall precipitation appears to decrease, heavy rainfall events become more intense, and discharge rates of glacial melt water channels show a significant increase. The PROSA joint project (High-resolution measurements of morphodynamics in rapidly changing PROglacial Systems of the Alps) uses terrestrial and airborne LiDAR data and digital Photogrammetry to monitor surface changes in the Upper Kaunertal, Austrian Central Alps (64 km²). These are related to the deglaciation since the end of the LIA and to changes in hydrometeorological parameters since several decades ago. The aim of this study is to investigate a possible relationship between climate change signals and erosion rates in the proglacial area of the Gepatschferner. The morphodynamics of steep LIA moraines are assessed on multiple temporal scales: Long-term changes are analyzed based on multitemporal airborne images dating back to 1953. The recent development is measured using digital elevation models (DEM) generated from multitemporal airborne (2006, July 2012, September 2012) and terrestrial (July 2010, August 2010, September 2011, July 2012, September 2012) LiDAR surveys. Seasonal climate data of more than 40 years are analyzed to detect trends. Precipitation and discharge data of two extreme events in 2011 and 2012 that triggered slope-type debris flows are examined in detail. The moved sediment masses are quantified and related to the precipitation record.

  5. The Volumetric Impact of Biogenic Sediment Reworking on the Geomorphology and Shallow Stratigraphy of Barrier Islands

    NASA Astrophysics Data System (ADS)

    Grimes, Z. T.; Buynevich, I. V.; Darrow, J. S.; Seminack, C. T.; Griffis, N.

    2010-12-01

    In addition to physical processes operating along the dynamic, sand-dominated coastal landforms, biogenic activity affects their unconsolidated surfaces in a variety of ways, displacing large volumes of sediment and partially modifying their morphological elements. This is particularly well pronounced on isolated coastal landforms, such as several barrier islands along the U.S. Mid-Atlantic Coast and Sable Island (Canada), where populations of native and introduced organisms have a confined range of activity. Diverse communities of vertebrates (ungulates, carnivores, wading birds, and reptiles) produce well-pronounced trails (trampled areas) or extend into regions of mobile fine-to-coarse sand. Large ungulates, such as horses, deer, and wild boar not only leave deep hoofprint structures in sand (1-5 cm, depending on substrate properties), but can easily penetrate and dislocate substantial portions of thin soil horizons. For example, beyond their grazing impact on vegetation, several hundred feral horses on Assateague Island (Maryland-Virginia, USA) disturb sections of beach, dune, and shallow saltmarsh through compaction and displacement of surface sediment. Given hoofprint diameters of 8-12 cm, partial track and trackway overlap, and an uninterrupted activity period of only 1 hour/day, anywhere from 100 to more than 1200 m3 of sand may be affected by this population on a daily basis. The compaction alters the geomechanical properties of the sediment, particularly along partially saturated intertidal areas. On steeply sloping dunes, which may be traversed numerous times by several individuals, grainflows are common, often leading to partial collapses of the dune slope. In addition to vertebrate trampling and burrowing (e.g., turtle nests), large invertebrates produce distinct bioturbation structures in the upper 0.5-1.0 m of barrier sands. A single ghost crab burrow in the backshore region may attain 4-5 cm in diameter, resulting in the removal and shifting of 3,500 cm3 of sand. Such biogenic structures not only affect the primary physical formations along beach, dune, and washover sequences, but also create interference patterns on high-resolution geophysical images. Due to a dielectric contrast between air-filled cavities (~1) and the surrounding sediment (~5-30), such techniques as ground-penetrating radar are being increasingly applied to identify and map biogenic structures in order to assess the impact of the biota on substrate integrity and slope stability in terrestrial and coastal settings.

  6. Water as Rural Heritage: Reworking Modernity through Resource Conflict in Edwards County, Kansas

    ERIC Educational Resources Information Center

    Solis, Patricia

    2005-01-01

    Conflicts over changing uses of natural resources are familiar within communities of the Western US and are usually resolved through legal processes. This paper analyzes resource conflict through juxtaposing impact analyses often used in their juridical resolution with discourse analyses of affected rural communities. The purchase of property by a…

  7. No Work Like Rework: Issues in the Design of a Math Test Sign-Up Application

    ERIC Educational Resources Information Center

    Alkadi, Ghassan; Beaubouef, Theresa

    2012-01-01

    This paper introduces a test sign-up application developed for a math department at a university. The requirements, design, and final software product are presented, along with one very important unexpected problem that arose after completion of the work--the system to be implemented and maintained by the client was not compatible with the…

  8. Recent research on the Chesapeake Bay impact structure, USA - Impact debris and reworked ejecta

    USGS Publications Warehouse

    Horton, J.W.; Aleinikoff, J.N.; Kunk, M.J.; Gohn, G.S.; Edwards, L.E.; ,; Powars, D.S.; Izett, G.A.

    2005-01-01

    Four new coreholes in the western annular trough of the buried, late Eocene Chesapeake Bay impact structure provide samples of shocked minerals, cataclastic rocks, possible impact melt, mixed sediments, and damaged microfossils. Parautochthonous Cretaceous sediments show an upward increase in collapse, sand fluidization, and mixed sediment injections. These impact-modifi ed sediments are scoured and covered by the upper Eocene Exmore beds, which consist of highly mixed Cretaceous to Eocene sediment clasts and minor crystalline-rock clasts in a muddy quartz-glauconite sand matrix. The Exmore beds are interpreted as seawater-resurge debris flows. Shocked quartz is found as sparse grains and in rock fragments at all four sites in the Exmore, where these fallback remnants are mixed into the resurge deposit. Crystalline-rock clasts that exhibit shocked quartz or cataclastic fabrics include felsites, granitoids, and other plutonic rocks. Felsite from a monomict cataclasite boulder has a sensitive high-resolution ion microprobe U-Pb zircon age of 613 ?? 4 Ma. Leucogranite from a polymict cataclasite boulder has a similar Neoproterozoic age based on muscovite 40Ar/39Ar data. Potassium-feldspar 40Ar/39Ar ages from this leucogranite show cooling through closure (???150 ??C) at ca. 261 Ma without discernible impact heating. Spherulitic felsite is under investigation as a possible impact melt. Types of crystalline clasts, and exotic sediment clasts and grains, in the Exmore vary according to location, which suggests different provenances across the structure. Fractured calcareous nannofossils and fused, bubbled, and curled dinofl agellate cysts coexist with shocked quartz in the Exmore, and this damage may record conditions of heat, pressure, and abrasion due to impact in a shallow-marine environment. ?? 2005 Geological Society of America.

  9. 30 CFR 256.70 - Extension of lease by drilling or well reworking operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... operations are approved by the Secretary according to the conditions set forth in 30 CFR 250.180. ..., DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL...

  10. 30 CFR 256.70 - Extension of lease by drilling or well reworking operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... operations are approved by the Secretary according to the conditions set forth in 30 CFR 250.180. ..., DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL...

  11. 30 CFR 256.70 - Extension of lease by drilling or well reworking operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... operations are approved by the Secretary according to the conditions set forth in 30 CFR 250.180. ..., DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL...

  12. It's time to Rework the Blueprints: Building a Science for Clinical Psychology

    ERIC Educational Resources Information Center

    Millon, Theodore

    2003-01-01

    The aims in this article are to connect the conceptual structure of clinical psychological science to what the author believes to be the omnipresent principles of evolution, use the evolutionary model to create a deductively derived clinical theory and taxonomy, link the theory and taxonomy to comprehensive and integrated approaches to assessment,…

  13. Reworking of School Principals' Roles in the Context of Educational Privatization: A View from Ukraine

    ERIC Educational Resources Information Center

    Kovalchuk, Serhiy; Shchudlo, Svitlana

    2014-01-01

    Educational privatization created new arrangements for funding, provision, and regulation of educational systems and their various stakeholders worldwide. This qualitative study examines the driving forces of privatization in the public education of Ukraine, focusing specifically on the professional roles of school principals who have been…

  14. Control of volatile organic compound emissions from coating operations at aerospace manufacturing and rework operations. Guideline series. Draft report

    SciTech Connect

    Hearne, D.G.; Reeves, D.W.

    1996-10-01

    The draft control techniques guideline (CTG) document identifies presumptive reasonably available control technology (RACT) for controlling volatile organic compounds (VOC) emissions from aerospace coatings and cleaning solvents. The CTG guidance also reflects EPA`s determination of best available control (BAC) measures for this industry. The CTG document is intended to provide State and local air pollution control authorities with an information base for proceeding with their evaluation and analyses of RACT for their own regulations.

  15. The Precambrian of Transangaria, Yenisei Ridge (Siberia): Neoproterozoic microcontinent, Grenville-age orogen, or reworked margin of the Siberian craton?

    NASA Astrophysics Data System (ADS)

    Kuzmichev, Alexander B.; Sklyarov, Eugene V.

    2016-01-01

    The Yenisei Ridge was traditionally perceived as an uplifted segment of the western Siberian craton affected by Neoproterozoic collision events. However, the suggestions for Archaean or Palaeoproterozoic ('Siberian') basement in Transangaria have not been confirmed by reliable geochronological data. A new view regards most of the Ridge, namely, its Transangarian segment, to be an exotic Neoproterozoic terrane that collided with Siberia in the late Neoproterozoic. This paper presents new U-Pb SHRIMP zircon ages demonstrating that Archaean rocks (2611 ± 12 Ma) actually exist in this territory. We also provide a review of published U-Pb zircon ages for igneous and metamorphic rocks of Transangaria together with our new age data. This geochronological dataset clarifies the geology of the Yenisei Ridge and leads to new conclusions, as follows. (1) It is likely that Transangaria was originally underlain by an Archaean-Palaeoproterozoic basement, similar to that of the Siberian craton. (2) Geochronological data do not confirm the idea of widespread "Greenvillian age" granitoides in Transangaria. (3) The Neoproterozoic evolution of the Yenisei Ridge segment of the Siberian craton margin includes the following events. (i) Collision of an unidentified terrane with the western margin (in recent coordinates) of the Siberian craton during 900-855 Ma. The colliding terrane is no longer present in the current structure. (ii) Dextral shearing during 830-800 Ma may have been caused by counter-clockwise rotation of the Siberian craton. (iii) Extensional conditions prevailed during 800-700 Ma. The Isakovka oceanic basin formed at this time interval. (iv) Thrusting of the Isakovka island arc and accretionary prism onto the Siberian margin occurred during the late Neoproterozoic (650-630 Ma) and caused high-pressure metamorphism.

  16. Equipment qualification research test of electrical cable with factor splices and insulation rework: Test no. 2, report no. 1

    NASA Astrophysics Data System (ADS)

    Minor, E. E.; Furgal, D. T.

    1982-09-01

    Electric cables with flame retardant chemically crosslinked polyolefin extruded insulation containing factory made center conductor splices and insulation repairs manufactured by the Rockbestos Company were used in a methodology test of the IEEE Standard 383-1974. Cable specimens were radiation aged at a low dose rate and then thermally aged to simulate a 40 year containment exposure. After aging, the specimens were subjected to LOCA radiation and a 33 day steam and chemical spray exposure. The cables were electrically loaded and functioned without failure during and after LOCA steam and chemical spray exposure. Insulation resistance measurements were taken during the exposure sequence. Subsequence to the exposures, hipot and mandrel bend tests were conducted. To determine the most severe cable aging sequence, cable insulation material samples were subjected to varied aging exposure to observe sequence related and dose rate related material degradation. A dose rate effect was observed.

  17. Reworking Practice through an AfL Project: An Analysis of Teachers' Collaborative Engagement with New Assessment Guidelines

    ERIC Educational Resources Information Center

    Hermansen, Hege; Nerland, Monika

    2014-01-01

    In recent years, the concept of Assessment for Learning (AfL) has travelled across countries, giving rise to a range of educational policy initiatives and school development projects. While researchers have focused on issues such as how formative assessment can support student learning and lead to more efficient classroom practices, less attention…

  18. River discharge controlling a tidal delta: the interplay between monsoon input and tidal reworking in SW Bangladesh

    NASA Astrophysics Data System (ADS)

    Hale, R. P.; Goodbred, S. L., Jr.; Bain, R. L.; Wilson, C.; Best, J.; Reed, M. J.

    2015-12-01

    The Ganges-Brahmaputra-Meghna River system (GBM) is among the world's largest in terms of both annual water and sediment discharge. The subaerial delta (110,000 km2) is home to ~160 million people, in addition to the ecologically and economically critical Sundarbans National Forest (SNF). Recent sediment budgets suggest that ~15% of the 1 x 109 t yr-1 sediment load carried by the GBM is subsequently advected along shore and inland via tidal activity, to the otherwise-abandoned SW portion of the delta. A unit-scale estimate based on observed offshore suspended sediment concentrations (SSC) >1.0 g L-1 suggests that sufficient sediment is available in the system to maintain the elevation of the subaerial delta plain, even under current relative sea-level-rise rates. Recent work measuring sedimentation within SNF corroborates this finding, and understanding these sediment delivery dynamics will be critical for protecting the future of nearby regions that are heavily populated, but drastically altered by human activities. Cross-channel hydrodynamic surveys were conducted to estimate what fraction of the water (and sediment) is diverted from the major tidal channels toward the SNF interior. Measurements including profiles of velocity and SSC were collected on spring and neap tides during the dry and monsoon seasons, along transects bracketing major conduit channels into the SNF. During the dry season, we observe water flux at the southern end of the study area to be in approximate equilibrium regardless of tidal range, with SSC <0.3 g L-1 during neap tides, and <1.0 g L-1 during spring tides. North of the SNF conduit channels, we observe equilibrium water discharge and similarly low SSC during neap tides, but a modest ebb dominance and surface SSC >1.0 g L-1 during spring tides. This suggests the possibility of additional inputs of water and sediment from an adjacent tidal channel, as well as a potential source for the deposition observed on the Sundarbans platform during spring-tide flooding. Within channels in SNF, near-bed SSC increase by >5x from neap to spring tides, to a peak of ~1.0 g L-1. Sediment grab samples collected in a distributary channel show a moderate fining trend with distance from the major conduit, which has implications for the sedimentation rates observed on the tidal delta plain.

  19. Last millennium gravity reworking processes in the western Gulf of Corinth: correlations with historical seismicity and indication of earthquake clusters

    NASA Astrophysics Data System (ADS)

    Beckers, Arnaud; Beck, Christian; Hubert-Ferrari, Aurélia; Papatheodorou, George; Reyss, Jean-Louis

    2016-04-01

    The western tip of the Corinth Rift is considered as the most active within this major extensional structure, as evidenced by: seismicity, GPS kinematics, and INSAR data (Bernard et al., 2006). Within the frame of a multidisciplinary project dedicated to seismic hazards assessment for this region, two offshore surveys - high resolution seismic reflection and gravity coring - were conducted in this area. They were dedicated to the Late Quaternary sedimentary fill as the latter was expected to record both long term deformation (Beckers et al., 2015) and sedimentary "events" related to major earthquakes and/or tsunamis. Seismic reflection imaging displays the time and geographical distributions of large submarine landslides (MTDs) during the last 100 kyr. Based on a morpho-sedimentary map and the active fault pattern, up to 2 m-long cores were selected to detect and characterize the possible impact of historical events. The chronological control is based on AMS 14C dating and four detailed 210Pb and 137Cs profiles. Sedimentation (components, sources, transport and settling mechanisms) was analysed through textural, chemical, and mineralogical parameters. Turbidites could be clearly separated from the hemipelagic deposits. Our attempt to correlate identified sedimentary "events" with historical data greatly benefited from a recently elaborated catalog (Albini et al., 2014) with precisely re-located epicentral areas. Cable breaks were also taken into account. Attenuation models (Papazachos & Papaioannou's, 1997) were used to discuss paleo-intensities vs. distance form epicentral areas. From the whole set of cores, the following results may be underlined: - the correlations between cores from the different sites are not complete, including for a few neighbouring sites belonging to the same morpho-sedimentary unit; we relate these discrepancies to the complex bottom morphology and/or to bottom currents responsible for local erosion; - for several well-documented earthquakes and tsunamis, we could not find a clearly recorded sedimentary impact; - non earthquake-triggered MTDs (as the 1963 event) produced specific layers identical to the major earthquakes impacts. At the difference, for a few cores from the deep axial floor, several sandy or silty turbidites permit to establish correlations: i) between coring sites, ii) with earthquakes which stroke two different areas, respectively east and west of the concerned part of the Gulf. Furthermore, the sedimentary events show a particular time distribution for the last 600 yr: - two intervals with short recurrences: a recent one (~1900 AD-Present or ~1750 AD-Present) and an older one (~1550 AD-1700 AD or ~1450 AD-1800 AD); these time distributions differ from each coring site; - a long "quiet" period (150 to 200 yr). From these results, we tentatively consider this sedimentary record as an indicator of a migration of seismogenic faulting activity. Ref.: Albini, P., et al., 2014. Techn. Rep. I.N.G.V. Roma. Beckers, A., et al., 2015. Marine Geology, 360:55-69 Bernard, P., et al., 2006. Tectonophysics, 426:7-30. Papazachos, C., Papaioannou, C., 1997. Journal of Seismology, 1:181-201.

  20. Reworked pyroclastic beds in the early Miocene of Patagonia: Reaction in response to high sediment supply during explosive volcanic events

    NASA Astrophysics Data System (ADS)

    Cuitiño, José I.; Scasso, Roberto A.

    2013-05-01

    Two meter-scale pyroclastic levels are interbedded within the early Miocene succession of the Estancia 25 de Mayo (Patagoniense transgression) and Santa Cruz formations in the foreland Austral (or Magallanes) Basin, Argentina. The Lower Pyroclastic Level (LPL) is a tabular body interbedded within offshore marine deposits, laterally continuous for 30 km and varying in thickness from few centimeters to around 4 m. Grain-size grades from coarse to extremely fine ash with upward-fining along with a northeastern-fining trends. Structureless fine to very fine tuffs dominate and rare parallel laminations are the only tractive sedimentary structures. The Upper Pyroclastic Level (UPL) lies within low energy fluvial deposits and is laterally discontinuous, and it is composed by lenticular bodies reaching a maximum of 15 m thick and 100 m wide, with a concave-up base and a plane top. Grain-size range is similar to the LPL but it coarsens upward. The lower portion of the UPL shows parallel lamination, current ripple lamination and mud drapes with large pumice lapilli and plant debris, whereas the upper portion shows parallel lamination and trough cross-stratification. Both pyroclastic levels are composed mainly of pumice grains and glass shards with minor proportions of quartz and plagioclase crystals and lithic fragments. The LPL shows no mixing with epiclastic material whereas the UPL shows an upward increase in epiclastic material, and an upward increment in the scale of cross-bedding. The large thickness in relation to the possible emission center and the content of plant debris of the LPL does not suggest a direct, submarine, ash-fallout origin. The LPL is interpreted as a deposit of hyperpycnal-flows generated at the coastal zone when tephra-laden rivers plunged into the ocean. Large amounts of well preserved plant debris support the hypothesis of a terrestrial source of the sediments. The UPL is entirely composed of tractive deposits, so an ash fallout origin is disregarded. This, together with the lenticular shape and the alluvial plain origin of the encasing sediments, suggests accumulation within fluvial channels. Cycles of upper-flow-regime parallel lamination, current-ripple lamination and mud drapes at the lower portion, suggest short-lived turbulent flows that initially filled semi-abandoned channels. They were followed by sheet floods and channel reactivation, expressed by large-scale cross-bedding. The low degree of particle mixing observed in both levels is explained by the inability of streams to erode the substrate as they are suddenly over-saturated with pyroclastic sediments during and after the eruption. The grain-size distribution of the LPL and geochemical data indicate a contemporaneous volcanic source located to the west/southwest in the Andean ranges, where the South Patagonian Batholith is presently located. Explosive volcanism deeply modifies "normal" sedimentary dynamics.

  1. A two-dimensional, time-dependent model of suspended sediment transport and bed reworking for continental shelves

    USGS Publications Warehouse

    Harris, C.K.; Wiberg, P.L.

    2001-01-01

    A two-dimensional, time-dependent solution to the transport equation is formulated to account for advection and diffusion of sediment suspended in the bottom boundary layer of continental shelves. This model utilizes a semi-implicit, upwind-differencing scheme to solve the advection-diffusion equation across a two-dimensional transect that is configured so that one dimension is the vertical, and the other is a horizontal dimension usually aligned perpendicular to shelf bathymetry. The model calculates suspended sediment concentration and flux; and requires as input wave properties, current velocities, sediment size distributions, and hydrodynamic sediment properties. From the calculated two-dimensional suspended sediment fluxes, we quantify the redistribution of shelf sediment, bed erosion, and deposition for several sediment sizes during resuspension events. The two-dimensional, time-dependent approach directly accounts for cross-shelf gradients in bed shear stress and sediment properties, as well as transport that occurs before steady-state suspended sediment concentrations have been attained. By including the vertical dimension in the calculations, we avoid depth-averaging suspended sediment concentrations and fluxes, and directly account for differences in transport rates and directions for fine and coarse sediment in the bottom boundary layer. A flux condition is used as the bottom boundary condition for the transport equation in order to capture time-dependence of the suspended sediment field. Model calculations demonstrate the significance of both time-dependent and spatial terms on transport and depositional patterns on continental shelves. ?? 2001 Elsevier Science Ltd. All rights reserved.

  2. Geoinformatic and geophysical methods for evaluation of deposition and reworking of sediments with contaminants in floodplain of the Ploucnice River, Czech Republic

    NASA Astrophysics Data System (ADS)

    Elznicova, Jitka; Matys Grygar, Tomas; Kiss, Timea; Babek, Ondrej; Popelka, Jan; Plotnarek, Lukas; Tumova, Stepanka; Majerova, Lucie; Hosek, Michal

    2014-05-01

    Complex study for the deposition and remobilization of pollutants in floodplain of the Ploucnice River requires geoinformatic, geomorphologic, geophysical and geochemical knowledge. Geoinformatic tools are usable in several science disciplines. Photogrammetric methods are a big tool for land-use change development and digital surface model (DSM) reconstruction. The historical photographs from 1938 till 1994 were orthorectified using ERDAS 2013 LPS software. Historical and actual orthophotos were used to study the channel migration of the Ploucnice River and lateral shifts of the channel in the last 70 years. Historical digital surfer model, which is reconstructed from historical orthophotos with 60% overlaps, were used for 3D visualisation of historical landscape and shows land-use changes. Accurate digital elevation model (DEM) from laser scanning dataset was created for geomorphological analysis. Topography was analysed with GIS methods and the geomorphologic interpretation was then performed. The subsurface architecture of the floodplain and distribution of the sediment bodies were studied using electrical resistivity tomography (ERT). The Wenner-Schlumberger method with 104 electrodes in a single array was used. An inverse model resistivity section was produced from the apparent resistivity pseudosection by the least-square inversion method using RES2DINV software (Geotomo Software, Malaysia). The contamination of the floodplain was analysed with both field and laboratory instruments. The portable gamma-spectrometer DISA 400A was used for acquisition of the total surface gamma activity in field. Several hundreds of soil samples (from drill cores) and recent flood deposits (after 2013 flood) were analysed by laboratory X-ray fluorescence spectrometer to describe deposition and remobilization of pollutants in floodplain, of which most important are Ba, Ni, Pb, U and Zn. Geostatistical analysis was used for creation of a statistically valid prediction surface. The map of distribution of the surface gamma activity and map for contribution of pollutants after flood in the spring 2013were interpolated.

  3. Tectono-metamorphic evolution of the internal zone of the Pan-African Lufilian orogenic belt (Zambia): Implications for crustal reworking and syn-orogenic uranium mineralizations

    NASA Astrophysics Data System (ADS)

    Eglinger, Aurélien; Vanderhaeghe, Olivier; André-Mayer, Anne-Sylvie; Goncalves, Philippe; Zeh, Armin; Durand, Cyril; Deloule, Etienne

    2016-01-01

    The internal zone of the Pan-African Lufilian orogenic belt (Zambia) hosts a dozen uranium occurrences mostly located within kyanite micaschists in a shear zone marking the contact between metasedimentary rocks attributed to the Katanga Neoproterozoic sedimentary sequence and migmatites coring domes developed dominantly at the expense of the pre-Neoproterozoic basement. The P-T-t-d paths reconstructed for these rocks combining field observations, microstructural analysis, metamorphic petrology and thermobarometry and geochronology indicate that they have recorded burial and exhumation during the Pan-African orogeny. Both units of the Katanga metasedimentary sequence and pre-Katanga migmatitic basement have underwent minimum peak P-T conditions of ~ 9-11 kbar and ~ 640-660 °C, dated at ca. 530 Ma by garnet-whole rock Lu-Hf isochrons. This suggests that this entire continental segment has been buried up to a depth of 40-50 km with geothermal gradients of 15-20 °C.km- 1 during the Pan-African orogeny and the formation of the West Gondwana supercontinent. Syn-orogenic exhumation of the partially molten root of the Lufilian belt is attested by isothermal decompression under P-T conditions of ~ 6-8 kbar at ca. 530-500 Ma, witnessing an increase of the geothermal gradients to 25-30 °C·km- 1. Uranium mineralizations that consist of uraninite and brannerite took place at temperatures ranging from ~ 600 to 700 °C, and have been dated at ca. 540-530 Ma by U-Pb ages on uraninite. The main uranium deposition thus occurred at the transition from the syn-orogenic burial to the syn-orogenic exhumation stages and has been then partially transposed and locally remobilized during the post-orogenic exhumation accommodated by activation of low-angle extensional detachment.

  4. Potential geothermal energy use at the Naval Air Rework Facilities, Norfolk, Virginia and Jacksonville, Florida, and at the naval shipyard, Charleston, South Carolina

    SciTech Connect

    Costain, J.K.; Glover, L. III; Newman, R.W.

    1984-05-01

    The feasibility of geothermal energy use at naval installations in Norfolk, VA, Jacksonville, FL, and Charleston, SC was assessed. Geophysical and geological studies of the above areas were performed. Engineering and economic factors, affecting potential energy use, were evaluated. The Norfolk and Jacksonville facilities are identified as candidates for geothermal systems. System costs are predicted. Economic benefits of the proposed geothermal systems are forecast, using the net present value method of predicting future income.

  5. Upwelling-driven reworking of a MTD's fine-grained plume: an example at the Cariaco Basin/Cariaco Gulf connection.

    NASA Astrophysics Data System (ADS)

    Aguilar, Iliana; Beck, Christian; Audemard, Franck; Crouzet, Christian; Sabatier, Pierre; Develle, Anne-Lise; Boussafir, Mohammed; Campos, Corina

    2016-04-01

    The Cariaco Basin is a 1400 m-deep and 90 km-wide pull-apart basin, in the south-eastern corner of the Caribbean Sea. To the East, it is connected to the Cariaco Gulf, a 60 km-long, 15 km-wide, and 90 m-deep appendix. Both are E-W elongated and developed upon the south-eastern transform boundary of the Caribbean Plate, an active limit here mainly represented by the El Pilar Fault. The Gulf of Cariaco entrance is a 55 m-deep, and 5 km-wide sill mainly controlled by the large Manzanares River delta, which western foreset slope is facing the Basin's eastern edge. Within this connection area, two particular sedimentary processes have been previously documented: 1) strong seasonal upwelling responsible for the transfer of deep particulate organic matter from the Basin into the Gulf; 2) the recent occurrence, in the Basin, of a fine-grained suspension related to a submarine landslide; this event was detected after the 1997 Cariaco earthquake (Thunell et al., 1999; Lorenzoni et al., 2012) and was related to a slope failure of the Manzanares delta western foreset. From short gravity cores retrieved in the Gulf, we analysed the last millennium of sedimentation (components, transport and settling processes) using classical proxies and physical properties. All parameters led to underline: - a permanent mixed provenance of particulate Organic Matter in the main part of the Gulf: i) in situ and ii) allochtonous; - the occurrence of coarse siliciclastic layers related to flooding from the southern edge of the Gulf; - the occurrence of one peculiar fine-grained siliciclastic layer with a widespread distribution, dated around 1850 AD; - an abrupt increase of open marine influence just after the above-mentioned layer. Concerning the "background" permanent sedimentation, these results confirm the importance of upwelling through the connection between the Gulf and the Basin (transfer of the "allochtonous" O.M.). For the fine-grained silicilastic "event", we could discard a consequence of flooding from the Manzanares River. We rather envisage an upwelling-driven suspension brought from the Basin and dispersed into the Gulf. We tentatively relate the genesis of this peculiar load to a mechanism similar to what was described for the 1997 event. A major earthquake-triggered tsunami occurred in 1853 in the concerned area, related to a MTD. We thus propose to correlate this peculiar layer with the 1853 event. Due to this earthquake and the associated tsunami, the upwelling transported fined-grained siliciclastics removed from the western slope of the Manzanares delta. Such a combination of a MTD-generated plume with the permanent upwelling may have occurred several times since the establishment of the connection during the post-MIS2 sea-level rise (Van Daele et al., 2011). The resulting specific layers may thus be used for paleo-earthquakes/paleo-tsunamis detection; furthermore, several major MTDs were imaged on high resolution seismic profiles across the concerned connecting area (Aguilar et al., 2015). Ref.: Aguilar, I., et al., 2015. Comptes Rendus Geoscience, in press. Lorenzoni, L., et al., 2012. Marine Geology, 307:105-110. Thunell, R., 1999. Nature, 398:233-236. Van Daele, M., et al., 2011, Marine Geology 279:37-51.

  6. Zircon Lu-Hf isotopes and granite geochemistry of the Murchison Domain of the Yilgarn Craton: Evidence for reworking of Eoarchean crust during Meso-Neoarchean plume-driven magmatism

    NASA Astrophysics Data System (ADS)

    Ivanic, Timothy J.; Van Kranendonk, Martin J.; Kirkland, Christopher L.; Wyche, Stephen; Wingate, Michael T. D.; Belousova, Elena A.

    2012-09-01

    New in situ Lu-Hf data on zircons from GSWA geochronology samples has provided a unique isotopic dataset with a high temporal resolution for the Murchison Domain of the Yilgarn Craton in Western Australia. These data identify extended periods of juvenile mantle input (positive ɛHf values) into the crust firstly at c. 2980 Ma and then from c. 2820 Ma to c. 2640 Ma with significant pulses of crustal recycling at c. 2750 Ma and c. 2620 Ma (highly negative ɛHf values). Geochemical data from well-characterised granitic suites of the Murchison Domain provide additional constraints on the crustal evolution of the area and indicate a prolonged period of crustal melting and remelting at progressively shallower depths from c. 2750 to c. 2600 Ma. At c. 2760-2753 Ma, widespread calc-alkaline, intermediate to silicic volcanic rocks of the Polelle Group were erupted, accompanied by intrusion of felsic to intermediate melts derived from a variety of crustal sources that likely formed by partial mixing with basaltic melts. The intrusive rocks include a wide geochemical array of rocks in the Cullculli and Eelya suites that were sourced over a wide range of crustal depths. At this time a major departure to negative ɛHf values (<-5) occurred, indicating sampling of c. 3.80 Ga model aged source rocks as well as continued juvenile input. Post-volcanic granitic rocks emplaced between c. 2710 and c. 2600 Ma show geochemical evidence for progressive fractionation through time and derivation from an evolving crustal source. We interpret the driving force for this protracted history of mantle and crustal melting to be two mantle plumes at 2.81 and 2.72 Ga. These data document the process of cratonization through progressive melt depletion of the lower crust, progressively fractionating and shallower melts, culminating with a final phase of crustal recycling (ɛHf < - 5) and the cessation of juvenile input at c. 2630-2600 Ma during intrusion of the Bald Rock Supersuite, resulting in cratonization of this part of the Yilgarn Craton.

  7. Beyond Work First: How To Help Hard-To-Employ Individuals Get Jobs and Succeed in the Workforce. A How-To Guide. ReWORKing Welfare: Technical Assistance for States and Localities.

    ERIC Educational Resources Information Center

    Brown, Amy

    This guide distills lessons from an extensive body of research into practical advice for policymakers and practitioners concerned with helping hard-to-employ individuals find jobs and succeed in the work force. Part 1 examines the following topics: characteristics of the hard-to-employ; the prevalence of various barriers to employment; and the…

  8. Covering Cavities by Electrodeposition

    NASA Technical Reports Server (NTRS)

    Schmeets, M.; Duesberg, J.

    1986-01-01

    Reworking technique allows complex surfaces to be reshaped. Contours of large machined parts reworked quickly and inexpensively by electrodeposition and machining, with little risk of damage. Reworking method employs simple, reliable, well-known procedures.

  9. 75 FR 40827 - Proposed Consent Decree, Clean Air Act Citizen Suit

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-14

    ...) Aerospace Manufacturing and Rework Facilities (40 CFR part 63, subpart GG); (13) Mineral Wool Production (40...) Ferroalloys Production: Ferromanganese and Silicomanganese (40 CFR part 63, subpart XXX); ] (16)...

  10. Reduction of construction wastes by improving construction contract management: a multinational evaluation.

    PubMed

    Mendis, Daylath; Hewage, Kasun N; Wrzesniewski, Joanna

    2013-10-01

    The Canadian construction industry generates 30% of the total municipal solid waste deposited in landfills. Ample evidence can be found in the published literature about rework and waste generation due to ambiguity and errors in contract documents. Also, the literature quotes that disclaimer clauses in contract documents are included in the contractual agreements to prevent contractor claims, which often cause rework. Our professional practice has also noted that there are several disclaimer clauses in standard contract documents which have the potential to cause rework (and associated waste). This article illustrates a comparative study of standard contractual documents and their potential to create rework (and associated waste) in different regions of the world. The objectives of this study are (1) to analyse standard contractual documents in Canada, the USA and Australia in terms of their potential to generate rework and waste, and (2) to propose changes/amendments to the existing standard contract documents to minimise/avoid rework. In terms of construction waste management, all the reviewed standard contract documents have deficiencies. The parties that produce the contract documents include exculpatory clauses to avoid the other party's claims. This approach tends to result in rework and construction waste. The contractual agreements/contract documents should be free from errors, deficiencies, ambiguity and unfair risk transfers to minimise/avoid potential to generate rework and waste.

  11. 48 CFR 15.408 - Solicitation provisions and contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Acquisitions at or below the simplified acquisition threshold; (ii) Construction or architect-engineer services..., travel, computer and consultant services, preservation, packaging and packing, spoilage and rework, and... provision for experienced or anticipated allowances, such as shrinkage, rework, design changes, etc....

  12. 48 CFR 15.408 - Solicitation provisions and contract clauses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Acquisitions at or below the simplified acquisition threshold; (ii) Construction or architect-engineer services..., travel, computer and consultant services, preservation, packaging and packing, spoilage and rework, and... provision for experienced or anticipated allowances, such as shrinkage, rework, design changes, etc....

  13. Acid Test For Annealing Of Welds

    NASA Technical Reports Server (NTRS)

    Deese, Gary E.; Ellgass, Joseph P.

    1989-01-01

    Solution changes color if heat-treated condition lost. Simple test indicates whether welded joint retained its postweld heat-treated condition after reworking including rewelding and grinding. Test used instead of Rockwell or Brinell hardness tests when reworked surface inaccessible to hardness-testing apparatus or when small surface imperfections created by apparatus unacceptable.

  14. NASA-DoD Lead-Free Electronics Project

    NASA Technical Reports Server (NTRS)

    Kessel, Kurt

    2007-01-01

    The primary technical objective of the project is to undertake comprehensive testing to generate information on failure modes/criteria to better understand the reliability of: Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with lead-free alloys Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with mixed (lead/lead-free) alloys.

  15. Speaking Habermas to Gramsci: Implications for the Vocational Preparation of Community Educators

    ERIC Educational Resources Information Center

    Bamber, John; Crowther, Jim

    2012-01-01

    Re-working the Gramscian idea of the "organic" intellectual from the cultural-political sphere to Higher Education (HE), suggests the need to develop critical and questioning "counter hegemonic" ideas and behaviour in community education students. Connecting this reworking to the Habermasian theory of communicative action, suggests that these…

  16. Reduction of construction wastes by improving construction contract management: a multinational evaluation.

    PubMed

    Mendis, Daylath; Hewage, Kasun N; Wrzesniewski, Joanna

    2013-10-01

    The Canadian construction industry generates 30% of the total municipal solid waste deposited in landfills. Ample evidence can be found in the published literature about rework and waste generation due to ambiguity and errors in contract documents. Also, the literature quotes that disclaimer clauses in contract documents are included in the contractual agreements to prevent contractor claims, which often cause rework. Our professional practice has also noted that there are several disclaimer clauses in standard contract documents which have the potential to cause rework (and associated waste). This article illustrates a comparative study of standard contractual documents and their potential to create rework (and associated waste) in different regions of the world. The objectives of this study are (1) to analyse standard contractual documents in Canada, the USA and Australia in terms of their potential to generate rework and waste, and (2) to propose changes/amendments to the existing standard contract documents to minimise/avoid rework. In terms of construction waste management, all the reviewed standard contract documents have deficiencies. The parties that produce the contract documents include exculpatory clauses to avoid the other party's claims. This approach tends to result in rework and construction waste. The contractual agreements/contract documents should be free from errors, deficiencies, ambiguity and unfair risk transfers to minimise/avoid potential to generate rework and waste. PMID:23836104

  17. 30 CFR 250.180 - What am I required to do to keep my lease term in effect?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... this section, the term operations means, drilling, well-reworking, or production in paying quantities. The objective of the drilling or well-reworking must be to establish production in paying quantities... report to the District Manager according to paragraphs (h) and (i) of this section whenever...

  18. 40 CFR 63.746 - Standards: Depainting operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) National Emission Standards for Aerospace Manufacturing and Rework Facilities § 63.746 Standards... to an aerospace manufacturing or rework facility that depaints six or less completed aerospace... surface areas of completed aerospace vehicles, including the fuselage, wings, and vertical and...

  19. 40 CFR 63.746 - Standards: Depainting operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) National Emission Standards for Aerospace Manufacturing and Rework Facilities § 63.746 Standards... to an aerospace manufacturing or rework facility that depaints six or less completed aerospace... surface areas of completed aerospace vehicles, including the fuselage, wings, and vertical and...

  20. Effect of Rolling Bearing Refurbishment and Restoration on Bearing Life and Reliability

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.; Branzai, Emanuel V.

    2005-01-01

    For nearly four decades it has been a practice in commercial and military aircraft application that rolling-element bearings removed at maintenance or overhaul be reworked and returned to service. The work presented extends previously reported bearing life analysis to consider the depth (Z(45)) to maximum shear stress (45) on stressed volume removal and the effect of replacing the rolling elements with a new set. A simple algebraic relationship was established to determine the L(10) life of bearing races subject to bearing rework. Depending on the extent of rework and based upon theoretical analysis, representative life factors (LF) for bearings subject to rework ranged from 0.87 to 0.99 the lives of new bearings. Based on bearing endurance data, 92 percent of the bearing sets that would be subject to rework would result in L(10) lives equaling and/or exceeding that predicted for new bearings with the remaining 8 percent having the potential to achieve the analytically predicted life of new bearings when one of the rings is replaced at rework.. The potential savings from bearing rework varies from 53 to 82 percent that of new bearings depending on the cost, size and complexity of the bearing.

  1. Building America Top Innovations 2013 Profile – Quality Management System Guidelines

    SciTech Connect

    none,

    2013-09-01

    This Top Innovation profile describes quality management system tools that were customized for residential construction by BSC, IBACOS, and PHI, for use by builders, trades, and designers to help eliminate mistakes that would require high-cost rework.

  2. 76 FR 12728 - Agency Information Collection Activities OMB Responses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... 2395.01; Aerospace Manufacturing And Rework Industry Information Collection; was approved on 02/03/2011... change. EPA ICR Number 2398.02; Regulation of Fuels and Fuel Additives: 2011 Renewable Fuel...

  3. Internal auditing of the revenue cycle: are you getting your fair share?

    PubMed

    Egusquiza, Day

    2007-02-01

    Internal auditing of the revenue cycle begins with the collection of data regarding areas of risk, including: Rework. Rejected claims. Multiple "touches" to submit a clean claim. Lost revenue. Patient complaints. Poor or incomplete documentation.

  4. Late Quaternary stratigraphy and depositional history of the Long Island Sound basin

    USGS Publications Warehouse

    Lewis, Ralph S.; Stone, Janet R.

    1991-01-01

    Where quiet waters prevail, marine mud generally less than 15 m thick blankets the older deposits of the Basin. Elsewhere, especially in eastern LIS, tidal currents are actively reworking and transporting glacial and postglacial deposits.

  5. Mud, Macrofauna and Microbes: An ode to benthic organism-abiotic interactions at varying scales

    EPA Science Inventory

    Benthic environments are dynamic habitats, subject to variable sources and rates of sediment delivery, reworking from the abiotic and biotic processes, and complex biogeochemistry. These activities do not occur in a vacuum, and interact synergistically to influence food webs, bi...

  6. 40 CFR 63.745 - Standards: Primer and topcoat application operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CATEGORIES (CONTINUED) National Emission Standards for Aerospace Manufacturing and Rework Facilities § 63.745... device). Aerospace equipment that is no longer operational, intended for public display, and not...

  7. 40 CFR 63.752 - Recordkeeping requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) National Emission Standards for Aerospace Manufacturing and Rework Facilities § 63.752 Recordkeeping... malfunction; (D) The methods used to depaint aerospace vehicles during the malfunction period; (E) The...

  8. 40 CFR 63.752 - Recordkeeping requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) National Emission Standards for Aerospace Manufacturing and Rework Facilities § 63.752 Recordkeeping... malfunction; (D) The methods used to depaint aerospace vehicles during the malfunction period; (E) The...

  9. Biogeochemistry: Oxygen burrowed away

    NASA Astrophysics Data System (ADS)

    Meysman, Filip J. R.

    2014-09-01

    Multicellular animals probably evolved at the seafloor after a rise in oceanic oxygen levels. Biogeochemical model simulations suggest that as these animals started to rework the seafloor, they triggered a negative feedback that reduced global oxygen.

  10. NASA DOD Lead Free Electronics Project

    NASA Technical Reports Server (NTRS)

    Kessel, Kurt R.

    2008-01-01

    The primary'technical objective of this project is to undertake comprehensive testing to generate information on failure modes/criteria to better understand the reliability of: Packages (e.g., Thin Small Outline Package [TSOP], Ball Grid Array [BGA], Plastic Dual In-line Package [PDIPD assembled and reworked with lead-free alloys Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with mixed (lead/lead-free) alloys.

  11. NASA-DoD Lead-Free Electronics Project

    NASA Technical Reports Server (NTRS)

    Kessel, Kurt R.

    2009-01-01

    The primary technical objective of this project is to undertake comprehensive testing to generate information on failure modes/criteria to better understand the reliability of: (1) Packages (e.g., Thin Small Outline Package [TSOP], Ball Grid Array [BGA], Plastic Dual In-line Package [PDIP]) assembled and reworked with lead-free alloys, (2) Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with mixed (lead/lead-free) alloys.

  12. The impact of diamond extraction on natural denudation rates in the Diamantina Plateau (Minas Gerais, Brazil)

    NASA Astrophysics Data System (ADS)

    Barreto, Helen N.; Varajão, César A. C.; Braucher, Régis; Bourlès, Didier L.; Salgado, André A. R.; Varajão, Angélica F. D. C.

    2014-12-01

    The 10Be method was used to investigate the effect of mining activities on the natural denudation rates in alluvial sediments from catchments of the Southern Espinhaço Range (SER) in Minas Gerais State (Brazil). In this region, which is predominantly composed of quartzites, the 10Be concentrations were measured in alluvial sediments from catchments in a preserved natural area of the Serra do Cipó National Park and on the Diamantina Plateau, which was subjected to diamond extraction from beginnings of XVIII century until the end of the XX. Two types of drainage were identified in the Diamantina Plateau area: (i) reworked drainage (alluvial sediments reworked by panning) and (ii) overloaded drainage (alluvial sediments originating from panning processes on saprolites located upstream). The mean denudation value for the natural drainages (˜4.4 m.My-1) is similar to that of the reworked drainages (˜4.3 m.My-1) However, the denudation rates obtained for eleven samples from three sites in overloaded basins range from ˜6.4 m My-1 to ˜22.8 m My-1 and are thus higher than those determined for the reworked and natural basins. These results show that despite the alluvium deposits have been intensely reworked by panning, the values of denudation rates were not changed, they are similar to denudation rates from the natural drainages. However, the natural rates are lower than those affected by panning processes on saprolites.

  13. A change in the geodynamics of continental growth 3 billion years ago.

    PubMed

    Dhuime, Bruno; Hawkesworth, Chris J; Cawood, Peter A; Storey, Craig D

    2012-03-16

    Models for the growth of continental crust rely on knowing the balance between the generation of new crust and the reworking of old crust throughout Earth's history. The oxygen isotopic composition of zircons, for which uranium-lead and hafnium isotopic data provide age constraints, is a key archive of crustal reworking. We identified systematic variations in hafnium and oxygen isotopes in zircons of different ages that reveal the relative proportions of reworked crust and of new crust through time. Growth of continental crust appears to have been a continuous process, albeit at variable rates. A marked decrease in the rate of crustal growth at ~3 billion years ago may be linked to the onset of subduction-driven plate tectonics. PMID:22422979

  14. The role of the Asian monsoon in controlling erosion, weathering and the flux of sediment to the ocean

    NASA Astrophysics Data System (ADS)

    Clift, Peter

    2013-04-01

    The summer monsoon dominates the rainfall of South and SE Asia and is anticipated to be the primary control on continental erosion and weathering during the Quaternary when tectonic processes do not vary significantly except at local scales. Periods of strong monsoon generally correlate with interglacial, sealevel highstands. Such periods are recognized as times of enhanced reworking of stored sediment from flood plains or fluvial terraces within mountains, resulting in fast sedimentation being recorded in delta systems. Rising sealevels usually prevent large sediment volumes being reworked on to the continental slope, but what is deposited during periods of intensifying monsoon is more altered than sediment deposited prior to that time. In the South China Sea sedimentation on to the slope is largely driven by reworking of older weathered materials from the shelf, rather than directly from productive sources, such as Taiwan. Enhanced reworking is only curtailed by rising sealevels drowning the continental slope and shifting erosion further back onshore. While hotter, wetter conditions favor faster chemical weathering, the more weathered nature of sediment deposited at that time represents reworking of older stored sediment, not an immediate response to changing environmental conditions. New OSL dates from the Indus Basin support the idea of valley filling during time of strengthening monsoon followed by subsequent incision and reworking. Landslide damming caused by heavy summer rains may be a dominant process in this sediment buffering process, which results in lag times between initial erosion and delivery to the ocean on the order of 5-15 k.y. for finer grained sediment and potentially longer for dense detrital phases, such as zircon. Recognizing these lags is important when correlating marine erosion records with terrestrial climate records derived from lakes or caves if we are to understand the response of landscape to climate change.

  15. Dynamic monitoring of avalanches and barchan dune morphology change at different timescales

    NASA Astrophysics Data System (ADS)

    Nield, Joanna; Wiggs, Giles; Baddock, Matthew; Hipondoka, Martin

    2016-04-01

    Aeolian dune morphology responds dynamically to changing wind conditions. The lee slope avalanche dynamics of dunes are particularly sensitive to prior morphological conditions as well as the varying intensity and duration characteristics of sand transport events. Here we use terrestrial laser scanning (TLS) to measure dune surface change over minutes, hours, a week and a year during conditions of variable approach flow resulting in considerable lee slope reworking. Several different avalanche patterns are recognised that can be related to slope characteristics, wind direction and slope reworking. We find that during oblique winds, horn reworking can reduce the lee slope angle. When the dominant, formative winds of the barchan return, the reworked lee slope, perpendicular to the prior oblique wind, takes longer to start avalanching. In the central region of the dune, avalanche frequency and the extent of lee slope reworking depends on wind speed. Under high winds from the dominant direction, there is continual erosion near the dune brink central area, due to the exceedance of a critical angle of repose, whilst under weaker winds the frequency of grainfall sedimentation and avalanches diminishes and net deposition in the brink area is more common. During the week of measurements, changes to the crest-brink area and lee slope form are considerable, based on the reworking of the slope by avalanche events, and this ultimately influences the dune migration rate. Over the course of a year, we demonstrate that the shape of the barchan stoss and lee slopes can change significantly, whilst the overall dune size and general planform is maintained. Our findings help elucidate dune mobility mechanics and pattern modifications at the wind storm event scale.

  16. Pain, sympathy and the medical encounter between the mid eighteenth and the mid twentieth centuries

    PubMed Central

    Bourke, Joanna

    2014-01-01

    Witnessing people in pain inevitably elicits anxiety in physicians and other caregivers. Physicians are often required to inflict certain types of discomforts in order to alleviate other, more destructive, pains. Accusations that physicians lacked sympathy can be heard throughout the centuries. This article explores the diverse medical responses to such claims between the eighteenth and twentieth centuries. It interrogates changing definitions of clinical sympathy. The concept of sympathy was continually being reworked for each generation of medical professional. Crucially, in this reworking, philosophers (such as Adam Smith) and physicians came into dialogue. Cultures of sympathy were understood in both physiological and metaphorical terms, and were tied to changing notions of professionalization PMID:24489439

  17. In Situ Robotic Inspection Of Welds

    NASA Technical Reports Server (NTRS)

    Van Wyk, Lisa M.; Garcia, Raul C., Jr.; Gilbert, Jeffrey L.

    1992-01-01

    Automated system reduces delays in inspection and rework. System reduces inspection-and-rework delay from days to hours. Path of inspection sensors taken directly from welding path saving time in programming for inspection. Inspection data stored so not lost as inspection equipment turned off. Same robot welding workpiece used to inspect it. In preparation, welding tool mounted on end effector of robot replaced with eddy-current or ultrasonic sensor. Robot recalls welding path from memory and retraces it, recording sensor output as it proceeds.

  18. More Than Pushing a Broom

    ERIC Educational Resources Information Center

    Ward, James E.

    1976-01-01

    A course in building maintenance (at the Voc Tech Department of Pensacola Junior College, Florida) teaches students to maintain, repair, and rework existing facilities under the CETA program. The daily schedule includes one hour of classroom work covering related academic subjects and five hours spent working on a variety of projects. (LH)

  19. 78 FR 77615 - Airworthiness Directives; Bombardier, Inc. Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ... proposed AD. Discussion On June 10, 2010, we issued AD 2010-13-04, Amendment 39-16335 (75 FR 35622, June 23... above. Since we issued AD 2010-13-04, Amendment 39-16335 (75 FR 35622, June 23, 2010), Transport Canada... retention bolt, a reverse orientation of the retention bolt and a rework of the weight on wheel...

  20. 170. GENERAL VIEW DOWN WASP STREET. VIEW SOUTHSOUTHEAST DOWN WASP ...

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

    170. GENERAL VIEW DOWN WASP STREET. VIEW SOUTH-SOUTHEAST DOWN WASP ST. FROM 4TH AVE. SHOWING, FROM LEFT TO RIGHT, BUILDING D-180, 60 (AIR REWORK FACILITY), 458, 419, 418, 416, AND 19-20. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  1. A Jester's Guide to Creative See[k]ing across Disciplines

    ERIC Educational Resources Information Center

    Rosen, Diane

    2012-01-01

    For many centuries and in many cultures, jesters recited tales of heroic exploits, but they did more than simply recount past events--they amused, cajoled, and spun tales that transported listeners to the edge of mysterious, unmapped territories. Through the transformative power of play and the imagination, they reworked what was already…

  2. A COMPARATIVE STUDY OF DAY CLASS VS. INSTITUTIONALIZED EDUCABLE RETARDATES.

    ERIC Educational Resources Information Center

    REYNOLDS, MAYNARD C.; STUNKARD, CLAYTON L.

    THE PRESENT STUDY REPRESENTS AN EXTENSION OF A STUDY WHICH DEALT WITH THE LATER ADJUSTMENT OF INDIVIDUALS DISCHARGED FROM A STATE INSTITUTION FOR THE MENTALLY RETARDED. THIS EFFORT REWORKED AVAILABLE DATA TO DEVELOP A MORE EFFICIENT TECHNIQUE OF PREDICTION AND TO STUDY FURTHER INTERACTIONS AMONG THE VARIOUS CHARACTERISTICS OF THE GROUP. IN…

  3. Alternative Ways of Expressing and Reading Identity

    ERIC Educational Resources Information Center

    Higgins, Jane; Nairn, Karen; Sligo, Judith

    2009-01-01

    This paper explores the use of an "anti-CV" (anti-Curriculum Vitae), or identity portfolio, as a data collection instrument in research with young people. We analyse four visually based anti-CVs created by participants in a project on youth transitions, exploring their use of symbolism and space to show how these young people reworked public…

  4. "We Could Think of Things That Could Be Science": Girls' Re-Figuring of Science in an Out-Of-School-Time Club

    ERIC Educational Resources Information Center

    Gonsalves, Allison; Rahm, Jrène; Carvalho, Alice

    2013-01-01

    Grounded in sociocultural theory, this study explores how the figured world of science is reworked through a series of multi-media activities that were introduced into a girls-only conversation club in an after school program for Teens. The study is part of a multi-sited ethnography in which we explored youths' engagement with science within…

  5. Cultivating Disruptive Subjectivities: Interrupting the New Professionalism

    ERIC Educational Resources Information Center

    Herr, Kathryn

    2015-01-01

    This paper explores the everyday enactments of new public management in our professional lives utilizing principles of self-ethnography. Drawing on the reworking of an Action Research class, I explore the possibilities of a contextual analysis of the workplace to make more transparent the enactment of new public management. Little is known…

  6. Showdown Shapes Up Over Pollution Laws

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1974

    1974-01-01

    Discusses technological, legislative, and administrative problems facing the implementation of the 1972 air and water pollution control acts. Indicates that a congressional reworking on the pollution laws appears to be in the offing which could lead to a softening of environmental deadlines and a change in spending for pollution controls. (CC)

  7. Indianapolis Plan Suggests Blueprint for Other Districts

    ERIC Educational Resources Information Center

    Samuels, Christina A.

    2012-01-01

    An Indianapolis-based nonprofit organization has crafted a sweeping plan for reworking the 33,000-student Indianapolis school system that would place the district under the control of the city's mayor, pare down the money spent in central administration, and give principals broad authority to hire and fire teachers. The reform plan created by the…

  8. Hydrostatic liquid-bearing for precision gyro

    NASA Technical Reports Server (NTRS)

    Sgambati, R. J.

    1971-01-01

    Unit with 2W power increase and slightly larger overall dimensions performs as well as or better than its gas-bearing counterpart. Liquid-bearings are built by reworking serviceable gas-bearing components /sleeves, endplates, and cylinders/. Hydrostatic bearing is self-centered, requiring no magnetic suspension or centering jewel.

  9. 75 FR 49370 - Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-13

    ... to the specified products. That NPRM was published in the Federal Register on April 2, 2010 (75 FR...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have... production reworks have been identified. This * * * AD * * * requires for the vacuum loss hole...

  10. 75 FR 16689 - Airworthiness Directives; Airbus Model A318, A319, A320, and A321 Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ... Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant economic... identified. Inspections include vacuum loss inspections for de-bonding of the rudders in reinforced areas and... where production reworks have been identified. Inspections include vacuum loss inspections for...

  11. 75 FR 16685 - Airworthiness Directives; Airbus Model A300-600 and A310 Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... production reworks have been identified. This * * * AD * * * also requires for the vacuum loss hole... this thermographic inspection has been performed in the reinforced area. The inspections include...

  12. How Reuse Influences Productivity in Object-Oriented Systems

    NASA Technical Reports Server (NTRS)

    Basili, Victor R.; Briand, Lionel C.; Melo, Walcelio L.

    1997-01-01

    Although reuse is assumed to be especially valuable in building high quality software as well as in Object Oriented (OO) development, limited empirical evidence connects reuse with productivity and quality gains. The author's eight system study begins to define such benefits in an OO framework, most notably in terms of reduce defect density and rework as well as in increased productivity.

  13. 75 FR 3127 - Airworthiness Directives; Thrush Aircraft, Inc. Model 600 S2D and S2R Series Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-20

    ..., 1996. Steps 7 and 8 in the Rework section of this service bulletin require the bolt holes to be reamed... (68 FR 15653), the Director of the Federal Register approved the incorporation by reference of Quality... FR 36055), the Director of the Federal Register approved the incorporation by reference of...

  14. 77 FR 36224 - Airworthiness Directives; Empresa Brasileira de Aeronautica S.A. (EMBRAER) Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... aluminum sheets; modifying the lights assembly on the tail boom rear movable fairing; and replacing the....] * * * * * The required actions include installing or reworking, as applicable, metallic diverters and...

  15. Assessment of Robust Learning with Educational Data Mining

    ERIC Educational Resources Information Center

    Baker, Ryan S.; Corbett, Albert T.

    2014-01-01

    Many university leaders and faculty have the goal of promoting learning that connects across domains and prepares students with skills for their whole lives. However, as assessment emerges in higher education, many assessments focus on knowledge and skills that are specific to a single domain. Reworking assessment in higher education to focus on…

  16. New Tales for Old: Folktales as Literary Fictions for Young Adults.

    ERIC Educational Resources Information Center

    de Vos, Gail; Altmann, Anna E.

    Focusing on reworkings of tales from the European oral folk tradition, this book shows educators how to use these tales effectively in the high school and middle school curriculum. The first chapter of the book, "Folktales and Literary Fictions" looks at the nature of folktales, their place in contemporary North American culture, and the…

  17. Designing an Australian Indigenous Studies Curriculum for the Twenty-First Century: Nakata's "Cultural Interface", Standpoints and Working beyond Binaries

    ERIC Educational Resources Information Center

    Carey, Michelle; Prince, Michael

    2015-01-01

    We discuss the recent reworking of Murdoch University's Australian Indigenous Studies major. For the discipline to realise its charter of decolonising knowledges about Indigenous peoples, it is necessary to move Indigenous Studies beyond the standard reversalist and unsustainable tropes that valorise romanticised notions of Indigeneity and…

  18. Developing a New Computer Game Attitude Scale for Taiwanese Early Adolescents

    ERIC Educational Resources Information Center

    Liu, Eric Zhi-Feng; Lee, Chun-Yi; Chen, Jen-Huang

    2013-01-01

    With ever increasing exposure to computer games, gaining an understanding of the attitudes held by young adolescents toward such activities is crucial; however, few studies have provided scales with which to accomplish this. This study revisited the Computer Game Attitude Scale developed by Chappell and Taylor in 1997, reworking the overall…

  19. Electrochemical Machining Removes Deep Obstructions

    NASA Technical Reports Server (NTRS)

    Catania, Mark J.

    1987-01-01

    Electrochemical machining (ECM) is effective way of removing obstructing material between two deep holes supposed to intersect but do not because of misalignment of drilling tools. ECM makes it possible to rework costly castings otherwise scrapped. Method fast even for tough or hard alloys and complicated three-dimensional shapes.

  20. Quality Management for Educational Technology Services: A Guide to Application of the Deming Management Method for District, University and Regional Media and Technology Centers.

    ERIC Educational Resources Information Center

    Richie, Mark L.

    This book shows how the quality management approach pioneered in Japan by Dr. W. Edwards Deming allows educational service centers to expand services and be more flexible by reducing waste and rework. Deming's method shows how to change from reactive management to a dynamic system of continuous improvement that restores worker pride, increases…

  1. 78 FR 10175 - Agency Information Collection Activities: Proposed Collection; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-13

    ... duplication, rework to correct errors or inconsistencies, role ambiguity, missing information, and lack of... research. The Preliminary Conference Call with each site will involve two people, the Practice Manager and the Physician Leader, and will require up to one hour per site. A total of 12 people across the...

  2. Technology's Impact on the Creative Potential of Youth

    ERIC Educational Resources Information Center

    Rubin, Jim

    2012-01-01

    The importance of educating students to think critically and creatively was recognized over 2,000 years ago by Socrates, reworked in the 1950s by Benjamin Bloom, and reinforced by many modern-day educators. With changes in lifestyle brought on by innovations in digital technology, teachers, administrators, and parents alike are questioning the…

  3. Offshore Outsourcing Drives Curriculum

    ERIC Educational Resources Information Center

    Swanson, Dewey A.

    2005-01-01

    Introduction to Application Development was completely reworked. Less emphasis was placed on programming and more emphasis on developing and communicating user requirements. Many items used in training industry were incorporated into the CPT 180 course. The paper will detail the change in focus in this course and overall how our curriculum is…

  4. Effects of bioturbation on seagrasses: Implications for management and restoration

    EPA Science Inventory

    Marine and estuarine fauna can diminish or enhance seagrass condition simply as a result of their burrowing, excavating, re-working, and feeding activities (e.g., bioturbation). We present the first comprehensive review of the effects of bioturbators on seagrasses and associated ...

  5. The Cross-Validational Accuracy of Sample Regressions.

    ERIC Educational Resources Information Center

    Rozeboom, William W.

    1981-01-01

    Browne's definitive but complex formulas for the cross-validational accuracy of an OSL-estimated regression equation in the random-effects sampling model are here reworked to achieve greater perspicuity and extended to include the fixed-effects sampling model. (Author)

  6. Goodbye to Camelot.

    ERIC Educational Resources Information Center

    Young, Carol C.

    1985-01-01

    Reviews Rosemary Sutcliffe's "The Sword and the Circle," a contemporary reworking of the Arthurian legend. Suggests that it fails by comparison with the versions of Tennyson and Malory because it depicts Arthur as a pawn of magicians rather than a duly elected leader working with his subjects to create a just society. (RBW)

  7. Research Teaching and Learning in Higher Education. Staff and Educational Development Series.

    ERIC Educational Resources Information Center

    Smith, Brenda, Ed.; Brown, Sally, Ed.

    This collection of 18 essays are based on sessions and keynote speeches at the Staff and Educational Development Association (SEDA) Conference held at Dyffrwn House, Cardiff (Wales) in November 1993. They represent the reworked and distilled thoughts of the presenters after they had had the experience of leading a workshop on a related topic. The…

  8. "Cirque du Freak."

    ERIC Educational Resources Information Center

    Rivett, Miriam

    2002-01-01

    Considers the marketing strategies that underpin the success of the "Cirque du Freak" series. Describes how "Cirque du Freak" is an account of events in the life of schoolboy Darren Shan. Notes that it is another reworking of the vampire narrative, a sub-genre of horror writing that has proved highly popular with both adult and child readers. (SG)

  9. The Mosque Project: Collective Drawings

    ERIC Educational Resources Information Center

    Erwin, Douglas B.

    2013-01-01

    Teaching the author's fifth-graders about Islam through art was a challenge. Remembering a colleague's "Collective Architecture" project, he reworked the concept using mosque architecture as the basis for a new project. The goal was to introduce Islam and its basic tenets using the visual arts, with the hope of enhancing cultural tolerance and…

  10. Georgia on Our Minds

    ERIC Educational Resources Information Center

    Skophammer, Karen

    2011-01-01

    Oil pastels offer many advantages. They come in a large range of hues, intensities and values, and they lend themselves to blending and shading in a unique way that no other art medium offers. They can be worked and reworked from day to day by the students without the large mess and cleanup time that oil paints require. An artist whose works are a…

  11. 40 CFR 63.4481 - Am I subject to this subpart?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... aerospace manufacturing and rework (40 CFR part 63, subpart GG). (12) Surface coating of plastic parts... CFR part 63, subpart IIII) at a facility that meets the applicability criteria in § 63.3081(b). (17... Coating of Automobiles and Light-Duty Trucks NESHAP (40 CFR part 63, subpart IIII) and you perform...

  12. 40 CFR 63.4481 - Am I subject to this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... aerospace manufacturing and rework (40 CFR part 63, subpart GG). (12) Surface coating of plastic parts... CFR part 63, subpart IIII) at a facility that meets the applicability criteria in § 63.3081(b). (17... Coating of Automobiles and Light-Duty Trucks NESHAP (40 CFR part 63, subpart IIII) and you perform...

  13. 40 CFR 63.3881 - Am I subject to this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... vehicles that meet the applicability criteria for aerospace manufacturing and rework (40 CFR part 63...-road vehicle subcategory in plastic parts and products surface coating (40 CFR part 63, subpart PPPP... CFR part 63, subpart IIII) at a facility that meets the applicability criteria in § 63.3081(b). (d)...

  14. Dancing Composition: Pedagogy and Philosophy as Experience

    ERIC Educational Resources Information Center

    Gould, Elizabeth

    2006-01-01

    For philosopher Gilles Deleuze, the work of philosophy consists of affirmatively and artistically creating and reworking concepts in response to real-life problems in an ongoing process that invites new perspectives and ways of thinking. Carol Matthews's music composition pedagogical practices reflect these processes, arguing that they demonstrate…

  15. "Without Contraries Is No Progression": Dust as an All-Inclusive, Multifunctional Metaphor in Philip Pullman's "His Dark Materials."

    ERIC Educational Resources Information Center

    Bird, Anne-Marie

    2001-01-01

    Draws on Milton's "Paradise Lost" and on motifs found within Gnostic mythology and the poetry of William Blake to explore how Philip Pullman reworks the Judeo-Christian myth of the Fall in his trilogy, "His Dark Materials." Finds at its center "Dust": a conventional metaphor for human physicality in which good and evil, and spirit and matter…

  16. 257. GENERAL VIEW OF SENIOR OFFICER'S QUARTERS, 194041. GEORGE A. ...

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

    257. GENERAL VIEW OF SENIOR OFFICER'S QUARTERS, 1940-41. GEORGE A. FULLER AND CO., DESIGNERS OF REWORKING OF THESE C. 1939 SUMMER COTTAGES INTO NEO-COLONIAL RESIDENCES. VIEW NORTHEAST DOWN GLENN CURTIS DRIVE SHOWING, FROM LEFT TO RIGHT: QUARTER P, O, N, C, A, S, R, AND Q. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  17. Morphology and sedimentation on open-coast intertidal flats of the Changjiang Delta, China

    USGS Publications Warehouse

    Fan, D.; Li, C.; Wang, D.; Wang, P.; Archer, A.W.; Greb, S.F.

    2004-01-01

    On many intertidal flats, lateral aggradation and reworking by large tidal channels is the dominant sedimentary process. On the open-coast intertidal flats of the Changjiang Delta large laterally migrating tidal channels are absent. Instead, numerous shallow tidal creeks cut across the intertidal flats. On these flats, vertical rather than lateral migration dominates sedimentation. Observations over semidiurnal tidal cycles show that both flood and ebb tides have the potential to deposit their own mud-sand couplets, but four couplets per day are rarely preserved. Reworking by tidal currents and/or weak waves results in loss of tidal couplets or amalgamation of two or more thin couplets into a single thick couplet. Measurements of preserved couplets show that they can represent a single flooding or ebbing event (half day) to a period of several neap-spring cycles. Diastems within amalgamated couplets are generally not distinguishable. The key agent for reworking open-coast intertidal flat deposits is not tidal creek migration but seasonal storm waves. Seasonal storm deposits consist of a basal scour and sand-dominant laminae with mud pebbles, grading upward to mud-dominated layers of fair-weather deposits. Sand-dominated layers are also reworked.

  18. Standpoints: Researching and Teaching English in the Digital Dimension

    ERIC Educational Resources Information Center

    Kirkland, David E.

    2009-01-01

    David E. Kirkland argues that our understanding of literate practice in relation to space needs to be radically reworked to account for new digital dimensions that are dispersed, discontinuous, and yet deeply woven into everyday and institutional worlds. His account highlights the way these digital spaces pepper the official landscape of…

  19. 75 FR 59710 - Agency Information Collection Activities; Submission to OMB for Review and Approval; Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-28

    ... subsequently changed; train personnel to be able to respond to a collection of information; search data sources... Information Collection Activities; Submission to OMB for Review and Approval; Comment Request; Aerospace Manufacturing and Rework Industry Information Collection AGENCY: Environmental Protection Agency (EPA)....

  20. Girlhood, Sexual Violence, and Agency in Francesca Lia Block's "Wolf"

    ERIC Educational Resources Information Center

    Marshall, Elizabeth

    2009-01-01

    This essay examines the representation of adolescent girlhood, sexual violence and agency in Francesca Lia Block's contemporary fairy tale collection "The Rose and The Beast." Focusing specifically on the tale "Wolf," the author provides a literary analysis of how Block draws on and reworks traditional Western fairy tale variants to reintroduce…

  1. 46 CFR 160.024-4 - Approval and production tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... reworking performed on the rejected lot, and the results of the second test. (1) Lot size. For the purposes... descent shall not exceed 1.8 m (6 ft.) per second. (v) Burning time. The burning time of the pyrotechnic... until it ceases. The burning time shall be not less than 30 seconds. EC03MR91.006 Table...

  2. The Living and the Dead in Education: Commentary on Julian Williams

    ERIC Educational Resources Information Center

    Jones, Peter E.

    2011-01-01

    Jean Lave and Ray McDermott (2002) did a service with their powerful reading of Marx's 1844 essay on "Estranged Labour" (Marx, 1964). In reworking Marx's critique of "alienated labour" in terms of "alienated learning," they reminded everyone of Marx's own impassioned revolt against the inhumanity of the capitalist order and found a novel way of…

  3. CH Stands for Cheese, Right? A Swiss Culture Class and the National Standards

    ERIC Educational Resources Information Center

    Seidlitz, Lisa

    2012-01-01

    Culture has always been a part of foreign language learning. However, in recent years, more and more language professors advocate placing culture at the center of our classes. The question of just how to teach culture remains a topic of debate. This paper describes the reworking of a traditional German grammar and reading course into a class that…

  4. Removing Bonded Integrated Circuits From Boards

    NASA Technical Reports Server (NTRS)

    Rice, John T.

    1989-01-01

    Small resistance heater makes it easier, faster, and cheaper to remove integrated circuit from hybrid-circuit board, package, or other substrate for rework. Heater, located directly in polymeric bond interface or on substrate under integrated-circuit chip, energized when necessary to remove chip. Heat generated softens adhesive or solder that bonds chip to substrate. Chip then lifted easily from substrate.

  5. Cowboys and Indians: Perceptions of Western Films among American Indians and Anglos.

    ERIC Educational Resources Information Center

    Shively, JoEllen

    1992-01-01

    Presents the results of a study of how minorities participate in and rework the central myths of the dominant culture. The responses of 20 Anglo White males versus 20 American Indian males to a western film showed that the meaning imputed to cultural works varies over social space. (JB)

  6. 40 CFR 63.4481 - Am I subject to this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... aerospace manufacturing and rework (40 CFR part 63, subpart GG). (12) Surface coating of plastic parts... Coating of Automobiles and Light-Duty Trucks NESHAP (40 CFR part 63, subpart IIII) and you perform surface... and Light-Duty Trucks NESHAP (40 CFR part 63, subpart IIII) in determining the predominant...

  7. 40 CFR 63.4481 - Am I subject to this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... aerospace manufacturing and rework (40 CFR part 63, subpart GG). (12) Surface coating of plastic parts... Coating of Automobiles and Light-Duty Trucks NESHAP (40 CFR part 63, subpart IIII) and you perform surface... and Light-Duty Trucks NESHAP (40 CFR part 63, subpart IIII) in determining the predominant...

  8. 40 CFR 63.4481 - Am I subject to this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... aerospace manufacturing and rework (40 CFR part 63, subpart GG). (12) Surface coating of plastic parts... Coating of Automobiles and Light-Duty Trucks NESHAP (40 CFR part 63, subpart IIII) and you perform surface... and Light-Duty Trucks NESHAP (40 CFR part 63, subpart IIII) in determining the predominant...

  9. 30 CFR 250.1301 - What are the requirements for unitization?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... production under § 250.170. (e) Unit operating agreement. The unit operator and the owners of working... well reworking program designed to develop or restore the lease or unit production; or (ii) MMS orders... natural resources; or (3) Protect correlative rights, including Federal royalty interests. (c) Unit...

  10. 16 CFR 1209.37 - Corrective actions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... taken. Corrective action includes changes to the manufacturing process as well as reworking the insulation product itself. Corrective action may consist of equipment adjustment, equipment repair, equipment replacement, change in chemical formulation, change in chemical quantity, change in cellulosic stock, or...

  11. Hybrid Doctoral Program: Innovative Practices and Partnerships

    ERIC Educational Resources Information Center

    Alvich, Dori; Manning, JoAnn; McCormick, Kathy; Campbell, Robert

    2012-01-01

    This paper reflects on how one mid-Atlantic University innovatively incorporated technology into the development of a hybrid doctoral program in educational leadership. The paper describes a hybrid doctoral degree program using a rigorous design; challenges of reworking a traditional syllabus of record to a hybrid doctoral program; the perceptions…

  12. Global Education Inc.: New Policy Networks and the Neoliberal Imaginary

    ERIC Educational Resources Information Center

    Ball, Stephen J.

    2012-01-01

    Do private and philanthropic solutions to the problems of education signal the end of state education in its "welfare" form? Education policy is being reformed and re-worked on a global scale. Policies are flowing and converging to produce a singular vision of "best practice" based on the methods and tenets of the "neo-liberal imaginary".…

  13. 77 FR 16145 - Airworthiness Directives; Bombardier, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-20

    ... 12866; 2. Is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034... leaf spring, and rework if necessary. This AD also requires installing a new friction brake nut. This... flight idle gate into the beta range due to an un-chamfered leaf spring in the friction brake that...

  14. Carbonate reservoirs at the Mesozoic-Tertiary unconformity, northeast Spain

    SciTech Connect

    Esteban, M.

    1988-08-01

    Carbonates at the Mesozoic-Tertiary unconformity in northeast Spain show four types/stages of evolution of reservoir properties: karstification, coastal reworking, Miocene organic buildups, and Pliocene burial. Subaerial exposure during Paleogene-early Miocene rifting developed a complex fracture-controlled paleokrast facies, showing up to three evolution levels with well-developed cavern and vuggy porosity (1). During the Miocene, the paleokrast profile was intensively reworked into a variety of breccias, conglomerates, and calcarenites in both alluvial and coastal depositional settings. Gravitational displacement of largely karstified hillsides was common. These reworked paleokarst deposits (2) present excellent reservoir properties. The Miocene formations onlap the karstified Mesozoic and the reworked facies; these formations include coral reefs and foramalgal buildups (3) with primary and secondary porosity. Finally, a late fracture event (attributed to the Pliocene) affected the buried and lithified paleokarst deposits and lower-middle Miocene formations (4). This fracture event is associated with vuggy corrosion, dolomitization, ore mineralization, and leaching of Mesozoic to middle Miocene carbonates. Several horizons with chalky microporosity are also tentatively related to this Pliocene event. These four phases of reservoir evolution are also recognized in northern Morocco and southern Italy.

  15. Advanced manufacturing development of a composite empennage component for L-1011 aircraft. Phase 4: Full scale ground test

    NASA Technical Reports Server (NTRS)

    Jackson, A. C.; Dorwald, F.

    1982-01-01

    The ground tests conducted on the advanced composite vertical fin (ACVF) program are described. The design and fabrication of the test fixture and the transition structure, static test of Ground Test Article (GTA) No. 1, rework of GTA No. 2, and static, damage tolerance, fail-safe and residual strength tests of GTA No. 2 are described.

  16. Developing and Validating Test Items for First-Year Computer Science Courses

    ERIC Educational Resources Information Center

    Vahrenhold, Jan; Paul, Wolfgang

    2014-01-01

    We report on the development, validation, and implementation of a collection of test items designed to detect misconceptions related to first-year computer science courses. To this end, we reworked the development scheme proposed by Almstrum et al. ("SIGCSE Bulletin" 38(4):132-145, 2006) to include students' artifacts and to…

  17. A Chance to Be Like Lance

    ERIC Educational Resources Information Center

    Prouty, Anne

    2004-01-01

    The authors' seventh-grade science curriculum includes a study of nutrition, anatomy, and physiology. Over several years, the authors' teaching partner and herself reworked the nine-week unit to include the Tour de France and the exploits of Lance Armstrong. What makes this unit so engaging for middle school students is that it provides an…

  18. Grinding Away Microfissures

    NASA Technical Reports Server (NTRS)

    Booth, Gary N.; Malinzak, R. Michael

    1990-01-01

    Treatment similar to dental polishing used to remove microfissures from metal parts without reworking adjacent surfaces. Any variety of abrasive tips attached to small motor used to grind spot treated. Configuration of grinding head must be compatible with configurations of motor and workpiece. Devised to eliminate spurious marks on welded parts.

  19. Spinning New Tales from Traditional Texts: Donna Jo Napoli and the Rewriting of Fairy Tale.

    ERIC Educational Resources Information Center

    Crew, Hilary S.

    2002-01-01

    Demonstrates how Donna Jo Napoli changes generic conventions and reworks discursive formations in order to retell tradition tales. Discusses the narrative strategies she uses in telling her stories, her representation of male and female characters in regard to gender and gendered relationships, and the way she renegotiates ideologies and value…

  20. "People in Stockholm Are Smarter than Countryside Folks"--Reproducing Urban and Rural Imaginaries in Film and Life

    ERIC Educational Resources Information Center

    Eriksson, Madeleine

    2010-01-01

    This article explores the celebrated film "The Hunters" (Swedish title: "Jagarna") within the context of the discourse of "Internal Orientalism." By juxtaposing a contemporary Swedish film with historical accounts and contemporary news media, I demonstrate how the film reworks and (re)produces representations of the rural North (Norrland),…

  1. 48 CFR 17.103 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... The key distinguishing difference between multiyear contracts and multiple year contracts is that... equipment, preproduction engineering, initial spoilage and rework, and specialized work force training. Recurring costs means costs that vary with the quantity being produced, such as labor and materials....

  2. The Learning-Focused Transformation of Biology and Physics Core Courses at the U.S. Air Force Academy

    ERIC Educational Resources Information Center

    Sagendorf, Kenneth; Noyd, Robert K.; Morris, D. Brent

    2009-01-01

    An institution-wide focus on deep learning has made significant changes in the biology and physics core course curriculum at the U.S. Air Force Academy. The biology course director has reworked course objectives to reflect the learning-focused approach to teaching, while the physics curriculum has adopted new learning outcomes and ways to…

  3. Drilling on midway atoll, Hawaii

    USGS Publications Warehouse

    Ladd, H.S.; Tracey, J.I., Jr.; Gross, M.G.

    1967-01-01

    Two holes drilled through reef sediments into basalt have established a geologic section through the Miocene. Midway was built above the sea by flows that were weathered and partially truncated in pre-Miocene time. After submergence, volcanic clays were reworked and covered by limestones. Overall submergence was interrupted at least twice by emergence. The limestones have been leached, recrystallized, and partially dolomitized.

  4. Failure analysis of ceramic-to-metal seals

    SciTech Connect

    Gates, W.G.

    1980-03-01

    Ceramic-to-metal seal failures that occur at the next assembly level present a critical problem because of the time and expense involved in the assembly of electro-mechanical switches. A typical analysis of a failed assembly and a recommended rework process is presented. In addition, steps are proposed to minimize the occurrence of future ceramic-to-metal seal failures.

  5. How Inconvenient Assumptions Affect Preservice Teachers' Uptake of New Interactional Patterns in Mathematics: Analysis and Aspiration through a Bifocal Lens

    ERIC Educational Resources Information Center

    Klein, Mary

    2012-01-01

    In this paper, I highlight the inadequacies of contemporary theoretical and philosophical orthodoxies to fully address pedagogic change. The required change is in mathematics education, and it has to do with enabling preservice teachers, upon graduation, to rework extant power relations in implementing new interactional patterns that centre the…

  6. 75 FR 50874 - Airworthiness Directives; Eurocopter France (Eurocopter) Model AS350B, BA, B1, B2, C, D, and D1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ...-053-AD; Amendment 39-16396; AD 2010-11-51] RIN 2120-AA64 Airworthiness Directives; Eurocopter France... document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2010-11-51... marked with an ``X'' near the part number or stripping the rework area and dye-penetrant inspecting...

  7. The Implicit Construction of "Children at Risk": On the Dynamics of Practice and Programme in Development Screenings in Early Childhood

    ERIC Educational Resources Information Center

    Bollig, Sabine; Kelle, Helga

    2013-01-01

    This article presents findings from an ethnographic study on preventive paediatric check-ups in Germany. In accordance with system-theoretical and governmentality approaches (referencing Foucault), preventive check-ups are conceptualised as fields where risk concepts related to children's development are applied, produced and reworked. In…

  8. Fabricated Childhoods: Uncanny Encounters with the More-than-Human

    ERIC Educational Resources Information Center

    Blaise, Mindy

    2016-01-01

    This article is based on uncanny encounters with Julia deVille's exhibit, "Phantasmagoria". Inspired by Deleuzian-informed research practices, the author experiments with provoking practices to defy dominant developmental notions of childhood. This article reworks a humanist ontology by bringing together the discursive, the material, the…

  9. 75 FR 76003 - Tricor Ten Section Hub LLC; Notice of Availability of the Environmental Assessment for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-07

    ... hydrostatic testing; 9 existing oil production wells in the field converted into observation wells; new 42,000... participate in the NEPA analysis. DOGGR has the authority to review Notices of Intent to drill or rework wells... new gas injection/withdrawal wells drilled from 5 well pads at the field; 2 new (low pressure and...

  10. 30 CFR 256.71 - Directional drilling.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... production plan, a lease may be maintained in force by directional wells drilled under the leased area from... adjoining land for the purpose of directional drilling under the leased area through any directional well surfaced on adjacent or adjoining land. Production, drilling or reworking of any such directional...

  11. 30 CFR 556.71 - Directional drilling.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... adjacent or adjoining land. Production, drilling, or reworking of any such directional well shall be... Directional drilling. In accordance with an approved exploration plan or development and production plan, a lease may be maintained in force by directional wells drilled under the leased area from...

  12. 30 CFR 556.71 - Directional drilling.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... adjacent or adjoining land. Production, drilling, or reworking of any such directional well shall be... Directional drilling. In accordance with an approved exploration plan or development and production plan, a lease may be maintained in force by directional wells drilled under the leased area from...

  13. 30 CFR 556.71 - Directional drilling.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... adjacent or adjoining land. Production, drilling, or reworking of any such directional well shall be... Directional drilling. In accordance with an approved exploration plan or development and production plan, a lease may be maintained in force by directional wells drilled under the leased area from...

  14. Laser geodynamic satellite thermal/optical/vibrational analyses and testing, volume 2, book 1 technical report. [retroreflector performance

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The results are presented of a retroreflector performance improvement program. The following areas of the program are discussed: retroreflector dimensional verification, initial optical performance analysis, LAGEOS test retroreflector rework, final optical performance analysis, optical performance tests, evaluations and conclusions, and laser wavelength evaluation and dihedral angle selection. Data tables, diagrams, graphs, and photographs are included.

  15. Race Moves: Following Global Manifestations of New Racisms in Intimate Space

    ERIC Educational Resources Information Center

    Mishra Tarc, Aparna

    2013-01-01

    This article makes tentative links between abstract global forces and the affective and material reworking of race in intimate spaces of culture and community. Using postcolonial and psychoanalytic resources the article follows enduring manifestations of race as racism surfaces and is mobilized through global shifts of people, ideas and capital.…

  16. 40 CFR 63.753 - Reporting requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... General Provisions, 40 CFR part 63, subpart A, and that the initial notification for existing sources... Emission Standards for Aerospace Manufacturing and Rework Facilities § 63.753 Reporting requirements. (a)(1... aerospace vehicles, other than from the exempt operations listed in § 63.746 (a), (b)(3), and (b)(5)....

  17. 40 CFR 63.753 - Reporting requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... General Provisions, 40 CFR part 63, subpart A, and that the initial notification for existing sources... Emission Standards for Aerospace Manufacturing and Rework Facilities § 63.753 Reporting requirements. (a)(1... aerospace vehicles, other than from the exempt operations listed in § 63.746 (a), (b)(3), and (b)(5)....

  18. 40 CFR 63.751 - Monitoring requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... performance specification (PS) 8 or 9 in 40 CFR part 60, appendix B, as appropriate depending on whether VOC or HAP concentration is being measured. The requirements in appendix F of 40 CFR part 60 shall also...) National Emission Standards for Aerospace Manufacturing and Rework Facilities § 63.751...

  19. THR ROLE OF SEABED DYNAMICS IN STRUCTURING A MESOHALINE MACROBENTIC INFAUNAL COMMUNITY

    EPA Science Inventory

    Estuaries are dynamic physical environments. The stability of the sediment-water interface is influenced by sources and rates of sediment delivery and reworking of sediments by currents, tides, waves and biology, but effects of disruption of this interface on benthic biology are...

  20. Adorno and the Borders of Experience: The Significance of the Nonidentical for a "Different" Theory of "Bildung"

    ERIC Educational Resources Information Center

    Thompson, Christiane

    2006-01-01

    In this essay Christiane Thompson discusses the systematic outcomes of Theodor Adorno's philosophical work for a reworked theory of "Bildung" (an important term in the German tradition of philosophy and history of education). In his essay "Theory of 'Halbbildung,'" Adorno revealed the inevitable failure of "Bildung," on the one hand, and the…

  1. Mass-wasting triggered by the end-Triassic mass-extinction

    NASA Astrophysics Data System (ADS)

    van de Schootbrugge, Bas; Vecoli, Marco; Strother, Paul; Lindstrom, Sofie; Oschmann, Wolfgang

    2014-05-01

    The end-Triassic dieback of tree-forming vegetation across NW Europe and the proliferation of a low-growing herbaceous pioneer vegetation composed of ferns and fern allies, likely had a major impact on weathering and erosion of emerged land masses. In a recently drilled core from northern Germany (Schandelah), palynological analyses provide evidence for this scenario. The uppermost Rhaetian Triletes Beds show increasing amounts of reworked Palaeozoic acritarchs and prasinophytes of up to 30% of the palynomorph fraction. Most of the acritarchs are singletons and can be assigned to Ordovician and Silurian species, such as Ankyrotrochus crispum, Oppilatala eoplanktonica, and Evittia spp. The average age of the reworked acritarch assemblages is observed to increase during the latest Rhaetian, leading to an inverted stratigraphy among Palaeozoic species. Further North, in the Stenlille cores from the Danish Basin, reworked Palaeozoic palynomorphs appear to constitute mainly sphaeromorphic prasinophytes and other Palaeozoic microfossils such as chitinozoans and carboniferous spores. Further south, at Mingolsheim (S Germany) the Triletes Beds contain a clear sign of soil reworking, including mycorrhizal fungal remains and cysts from probable soil organisms. These peculiar changes in palynological assemblages go hand-in-hand with important changes in sedimentology. The reworking of soil and bedrock is occurring in an interval that also contains evidence for earthquake activity in the form of widespread seismites. All these observations may be attributed to a number of mutually non-exclusive mechanisms, including decreased plant cover, an intensified hydrological cycle due to greenhouse warming, and the doming of the Central Atlantic Magmatic Province leading to continental-scale tectonic steepening of basin margins.

  2. Diamonds from the Espinhaço Range (Minas Gerais, Brazil) and their redistribution through the geologic record

    NASA Astrophysics Data System (ADS)

    Chaves, M. L. S. C.; Karfunkel, J.; Hoppe, A.; Hoover, D. B.

    2001-07-01

    Diamond-bearing deposits from the Espinhaço Range are associated with three distinct periods in the geologic record. During a Precambrian magmatic period (≥1.75 Ga), diamondiferous rocks were introduced into the crust; the location of these rocks remains an enigma. During a second period, diamonds were eroded from the primary rocks and deposited in the Mesoproterozoic Espinhaço basin (≅1.75-1.70 Ga), where several generations of reworking and diagenisis are suggested. The third period is the Phanerozoic, during which several more episodes of reworking occurred. The first was during the Eocretaceous uplift of the range, when Precambrian conglomerates were partially eroded and diamonds redeposited in fluvial systems. These deposits have little economic significance because of overlying Tertiary laterites. Renewed upheaval at the Neogene formed diamondiferous fanglomeratic deposits as a result of the pronounced relief. Quaternary climate cycling developed colluvial deposits on earlier formed occurrences. Fanglomeratic and colluvial deposits are worked where the adjacent Proterozoic or Cretaceous sources produced widespread diamond-bearing gravels. Finally, recent river systems have reworked all the earlier sources to produce economic gravels in some places. Although these recent gravels are low grade, they are a major diamond source because of the large reserves. The mineralogical characteristics of these diamonds reflect the long history and repeated reworking of the source deposits, and the geologic history of the region points towards an extra-basinal source area, probably to the west within the São Francisco Craton. This repeated reworking has resulted in a natural selection of the diamonds that eliminated low-quality stones in the journey to their final resting place.

  3. Origins of relief along contacts between eolian sandstones and overlying marine strata

    SciTech Connect

    Eschner, T.B.; Kocurek, G.

    1988-08-01

    Origins of large-scale relief along eolian-marine unit contacts, which form significant stratigraphic traps for hydrocarbons, can be recognized as inherited, reworked, and/or erosional. The Permian Rotliegende-Weissliegende Sandstone and Yellow Sands of Europe may best exemplify inherited relief in that dunes are preserved largely intact. Reworked relief, which shows significant destruction of original dune topography but with remnants of the bedforms preserved, is shown by relict Holocene dunes of coastal Australia, the Jurassic Entrada Sandstone of the San Juan basin, and the Pennsylvanian-Permian Minnelusa Formation of Wyoming. Erosional relief results from post-eolian processes and is exemplified by the Jurassic Entrada Sandstone of northeastern Utah. 11 figs., 1 tab.

  4. The failure analysis, redesign, and final preparation of the Brilliant Eyes Thermal Storage Unit for flight testing

    NASA Technical Reports Server (NTRS)

    Lamkin, T.; Whitney, Brian

    1995-01-01

    This paper describes the engineering thought process behind the failure analysis, redesign, and rework of the flight hardware for the Brilliant Eyes Thermal Storage Unit (BETSU) experiment. This experiment was designed to study the zero-g performance of 2-methylpentane as a suitable phase change material. This hydrocarbon served as the cryogenic storage medium for the BETSU experiment which was flown 04 Mar 94 on board Shuttle STS-62. Ground testing had indicated satisfactory performance of the BETSU at the 120 Kelvin design temperature. However, questions remained as to the micro-gravity performance of this unit; potential deviations in ground (1 g) versus space flight (0 g) performance, and how the unit would operate in a realistic space environment undergoing cyclical operation. The preparations and rework performed on the BETSU unit, which failed initial flight qualification, give insight and lessons learned to successfully develop and qualify a space flight experiment.

  5. The Precambrian terranes of Yemen and their correlation with those of Saudi Arabia and Somalia: Implications for the accretion of Gondwana

    USGS Publications Warehouse

    Windley, B.F.; Whitehouse, M.J.; Stoeser, D.B.; Al-Khirbash, S.; Ba-Bttat, M. A. O.; Al-Ghotbah, A.

    2001-01-01

    Most of the basement of Yemen consists of early Precambrian continental high-grade terranes and Neoproterozoic low-grade island arcs that were accreted together to form an arc-continent collage during the Pan-African orogeny (Windley et al., 1996; Whitehouse et al., 1998; Whitehouse et al., in press). The suture zones between the arc and gneiss terranes are major crustal- scale tectonic boundaries. The terranes are situated east of the Nabitah suture and of the collage of low-grade, mainly island arc terranes of the Arabian Shield, but they have been reworked by a Neoproterozoic event associated with island arc accretion. Further east in Yemen are mostly unconformable, very weakly deformed and very low-grade or unmetamorphosed sediments. Thus Yemen provides key information on the broad zone of Neoproterozoic reworking associated with the collisional boundary between western and eastern Gondwana. 

  6. Petroleum industry in Illinois, 1984. Oil and gas developments. Waterflood operations

    SciTech Connect

    Van Den Berg, J.; Treworgy, J.D.; Elyn, J.R.

    1986-01-01

    The report includes statistical information regarding the petroleum industry in Illinois during 1984. Illinois produced 28,873,000 barrels of crude oil in 1984. The value of this crude is estimated to be $830 million. New test holes drilled for oil and gas numbered 2732 - 4.1% more than in 1983. These tests resulted in 1575 oil wells, 21 gas wells, and 1136 dry holes. In addition, 28 former dry holes were reworked or deepened and completed as producers, and 9 former producers were reworked or deepened and completed as producers in new pay zones. In oil and gas exploration and development, including service wells and structure tests, total footage drilled in 1984 was 6,868,485 feet, 5.5% more than in 1983. Ten oil fields, 50 new pay zones in fields, and 51 extensions to fields were discovered in 1984.

  7. Proterozoic collisional tectonism in the Trans-Hudson orogen, Saskatchewan

    SciTech Connect

    Bickford, M.E.; Chiarenzelli, J.R.; Van Schmus, W.R. ); Collerson, K.D. ); Lewry, J.F. )

    1990-01-01

    Isotopic and structural data from the juvenile Reindeer zone of the Trans-Hudson orogen, northern Saskatchewan, indicate a pre-1.85 Ga thermotectonic event, possibly reflecting arc-continent collision, followed by a more extensive, nappe-forming, ca. 1.83-1.80 Ga thermotectonism during terminal continent-continent collision. Preliminary data from the adjacent, ensialic Cree Lake zone suggest high-grade reworking of Archean crust by the pre-1.85 Ga event. In the Rae province to the west, high-grade metamorphism and reworking of Archean crust occurred about 2.0 Ga and may be related to the formation of the coeval Taltson magmatic zone.

  8. U-series dating and stable isotope records of speleothem records from the Scladina Cave (Belgium)

    NASA Astrophysics Data System (ADS)

    van der Lubbe, Jeroen; Bonjean, Dominique; Hellstrom, John; Verheyden, Sophie; Vonhof, Hubert

    2015-04-01

    The Scladina cave, situated in the village of Sclayn (Ardennes, Belgium) at the southern bank of the Meuse, is famous for its Neanderthal fossils and artefacts. The infilling of the cave consists of a succession of flowstone layers interbedded with reworked loess sediment from outside the cave. The younger flowstone layers correspond to interglacials MIS 5 and the Holocene, while the reworked loess sediments represent cooler conditions. By careful diagenetic screening, well-preserved speleothem material was selected for U-series dating and stable isotope analysis of calcite and fluid inclusions. The results provide important new constraints on the age of Neanderthal fossils and artefacts, and bracket the time periods with a hydroclimate favorable for speleothem growth. The combination of fluid inclusion and calcite isotope analysis documents climate variability in the interglacials at high temporal resolution.

  9. NASA-DoD Lead-Free Electronics Project

    NASA Technical Reports Server (NTRS)

    Kessel, Kurt

    2009-01-01

    In response to concerns about risks from lead-free induced faults to high reliability products, NASA has initiated a multi-year project to provide manufacturers and users with data to clarify the risks of lead-free materials in their products. The project will also be of interest to component manufacturers supplying to high reliability markets. The project was launched in November 2006. The primary technical objective of the project is to undertake comprehensive testing to generate information on failure modes/criteria to better understand the reliability of: (1) Packages (e.g., Thin Small Outline Package [TSOP], Ball Grid Array [BGA], Plastic Dual In-line Package [PDIP]) assembled and reworked with solder interconnects consisting of lead-free alloys (2) Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with solder interconnects consisting of mixed alloys, lead component finish/lead-free solder and lead-free component finish/SnPb solder

  10. NASA-DoD Lead-Free Electronics Project

    NASA Technical Reports Server (NTRS)

    Kessel, Kurt R.

    2009-01-01

    In response to concerns about risks from lead-free induced faults to high reliability products, NASA has initiated a multi-year project to provide manufacturers and users with data to clarify the risks of lead-free materials in their products. The project will also be of interest to component manufacturers supplying to high reliability markets. The project was launched in November 2006. The primary technical objective of the project is to undertake comprehensive testing to generate information on failure modes/criteria to better understand the reliability of: - Packages (e.g., TSOP, BOA, PDIP) assembled and reworked with solder interconnects consisting of lead-free alloys - Packages (e.g., TSOP, BOA, PDIP) assembled and reworked with solder interconnects consisting of mixed alloys, lead component finish/lead-free solder and lead-free component finish/SnPb solder.

  11. NASA-DoD Lead-Free Electronics Project

    NASA Technical Reports Server (NTRS)

    Kessel, Kurt R.

    2009-01-01

    In response to concerns about risks from lead-free induced faults to high reliability products, NASA has initiated a multi-year project to provide manufacturers and users with data to clarify the risks of lead-free materials in their products. The project will also be of interest to component manufacturers supplying to high reliability markets. The project was launched in November 2006. The primary technical objective of the project is to undertake comprehensive testing to generate information on failure modes/criteria to better understand the reliability of: - Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with solder interconnects consisting of lead-free alloys - Packages (e.g., TSOP, BGA, PDIP) assembled and reworked with solder interconnects consisting of mixed alloys, lead component finish/lead-free solder and lead-free component finish/SnPb solder.

  12. Deterministic polishing from theory to practice

    NASA Astrophysics Data System (ADS)

    Hooper, Abigail R.; Hoffmann, Nathan N.; Sarkas, Harry W.; Escolas, John; Hobbs, Zachary

    2015-10-01

    Improving predictability in optical fabrication can go a long way towards increasing profit margins and maintaining a competitive edge in an economic environment where pressure is mounting for optical manufacturers to cut costs. A major source of hidden cost is rework - the share of production that does not meet specification in the first pass through the polishing equipment. Rework substantially adds to the part's processing and labor costs as well as bottlenecks in production lines and frustration for managers, operators and customers. The polishing process consists of several interacting variables including: glass type, polishing pads, machine type, RPM, downforce, slurry type, baume level and even the operators themselves. Adjusting the process to get every variable under control while operating in a robust space can not only provide a deterministic polishing process which improves profitability but also produces a higher quality optic.

  13. Large Area Crop Inventory Experiment (LACIE). LACIE phase 1 and phase 2 accuracy assessment. [Kansas, Texas, Minnesota, Montana, and North Dakota

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The author has identified the following significant results. The initial CAS estimates, which were made for each month from April through August, were considerably higher than the USDA/SRS estimates. This was attributed to: (1) the practice of considering bare ground as potential wheat and counting it as wheat; (2) overestimation of the wheat proportions in segments having only a small amount of wheat; and (3) the classification of confusion crops as wheat. At the end of the season most of the segments were reworked using improved methods based on experience gained during the season. In particular, new procedures were developed to solve the three problems listed above. These and other improvements used in the rework experiment resulted in at-harvest estimates that were much closer to the USDA/SRS estimates than those obtained during the regular season.

  14. Petrologic profile of Apollo 16 regolith at Station 4

    NASA Astrophysics Data System (ADS)

    Basu, A.; McKay, D. S.

    1984-11-01

    The Apollo 16 double drive tube core 64001/2 (total depth about 60 cm) consists of four petrologic units based on the modal abundance of lithic, monomineralic, and other particles in the 20-500 micron size range of samples from 12 levels. Variation in the abundance of particles derived directly from bedrocks is low and the core soils probably represent only one set of source rocks. The chemical signature of an excessively high mare basalt component at about 42 cm correlates with an excess of regolith breccias, which may then be the physical carrier. The core soils as a whole show a systematic size-composition relationship that may be attributed to a large-scale macroscopic reworking and the consequent masking of any or all previous surface process related mixing event. However, on a much smaller scale (about 0.5 cm), individual soil layers seem to have evolved more via mixing than via in situ reworking.

  15. Two-billion-year granulites in the late precambrian metamorphic basement along the southern peruvian coast.

    PubMed

    Dalmayrac, B; Lancelot, J R; Leyreloup, A

    1977-10-01

    Uranium-lead data indicate that the high-pressure granulitic and charnockitic nuclei within the medium-grade metamorphic complex of the Peruvian coastal area must be related to an orogenic event 2 x 10(9) years ago. As in western Africa and Brazil, this old granulitic basement is reworked by Late Precambrian orogeny. Its presence along the Peru-Chile Trench must be taken into account in interpreting the anomalously high strontium isotopic ratios of recent calc-alkaline volcanism.

  16. Process modeling and control in foundry operations

    NASA Astrophysics Data System (ADS)

    Piwonka, T. S.

    1989-02-01

    Initial uses of process modeling were limited to phenomenological descriptions of the physical processes in foundry operations, with the aim of decreasing scrap and rework. It is now clear that process modeling can be used to select, design and optimize foundry processes so that on-line process control can be achieved. Computational, analogue and empirical process models have been developed for sand casting operations, and they are being applied in the foundry with beneficial effects.

  17. Microcomputer Checks Butt-Weld Accuracy

    NASA Technical Reports Server (NTRS)

    Clisham, W.; Garner, W.; Cohen, C.; Beal, J.; Polen, R.; Lloyd, J.

    1982-01-01

    Electrical gage and microcomputer eliminate time-consuming manual measurements. Alinement and angle of plates on either side of butt weld are measured and recorded automatically by hand-held gage and desk-top microcomputer. Gage/micro-computer quickly determine whether weld is within dimensional tolerances or whether reworking is needed. Microcomputer prints out measurements while operator moves gage from point to point along weld. Out-of-tolerance measurements are marked by an asterisk on printout.

  18. Source and dispersal of silt on northern Gulf of Mexico Continental Shelf

    SciTech Connect

    Peterson, M.; Mazzullo, J.

    1988-02-01

    The surficial sediment on the continental shelf of the northern Gulf of Mexico is characterized by abundant silty clay which was deposited during the late Pleistocene lowstand and reworked during and after the Holocene transgression. The purposes of this study were to determine the sources of the silt fraction in this surficial sediment by quartz grain roundness and surface texture analysis, and to determine the effects of modern shelf currents upon the distribution of silt.

  19. Evaluating process origins of sand-dominated fluvial stratigraphy

    NASA Astrophysics Data System (ADS)

    Chamberlin, E.; Hajek, E. A.

    2015-12-01

    Sand-dominated fluvial stratigraphy is often interpreted as indicating times of relatively slow subsidence because of the assumption that fine sediment (silt and clay) is reworked or bypassed during periods of low accommodation. However, sand-dominated successions may instead represent proximal, coarse-grained reaches of paleo-river basins and/or fluvial systems with a sandy sediment supply. Differentiating between these cases is critical for accurately interpreting mass-extraction profiles, basin-subsidence rates, and paleo-river avulsion and migration behavior from ancient fluvial deposits. We explore the degree to which sand-rich accumulations reflect supply-driven progradation or accommodation-limited reworking, by re-evaluating the Castlegate Sandstone (Utah, USA) and the upper Williams Fork Formation (Colorado, USA) - two Upper Cretaceous sandy fluvial deposits previously interpreted as having formed during periods of relatively low accommodation. Both units comprise amalgamated channel and bar deposits with minor intra-channel and overbank mudstones. To constrain relative reworking, we quantify the preservation of bar deposits in each unit using detailed facies and channel-deposit mapping, and compare bar-deposit preservation to expected preservation statistics generated with object-based models spanning a range of boundary conditions. To estimate the grain-size distribution of paleo-sediment input, we leverage results of experimental work that shows both bed-material deposits and accumulations on the downstream side of bars ("interbar fines") sample suspended and wash loads of active flows. We measure grain-size distributions of bar deposits and interbar fines to reconstruct the relative sandiness of paleo-sediment supplies for both systems. By using these novel approaches to test whether sand-rich fluvial deposits reflect river systems with accommodation-limited reworking and/or particularly sand-rich sediment loads, we can gain insight into large

  20. Leading-Edge "Pop-Up" Spoiler For Airfoil

    NASA Technical Reports Server (NTRS)

    Wilson, John C.; Lance, Michael B.

    1991-01-01

    New concept places spoiler in leading edge of airfoil, hinged along its trailing edge, so airflow helps to deploy it and force it against mechanical stop. Deployed "pop-up" spoiler quickly eliminates almost all aerodynamic lift of stabilator. Designed to be added to leading edge of existing stabilator, without major rework. Though initial application to be on helicopter stabilators, equally applicable to wings or winglike components.

  1. Controlling Arc Length in Plasma Welding

    NASA Technical Reports Server (NTRS)

    Iceland, W. F.

    1986-01-01

    Circuit maintains arc length on irregularly shaped workpieces. Length of plasma arc continuously adjusted by control circuit to maintain commanded value. After pilot arc is established, contactor closed and transfers arc to workpiece. Control circuit then half-wave rectifies ac arc voltage to produce dc control signal proportional to arc length. Circuit added to plasma arc welding machines with few wiring changes. Welds made with circuit cleaner and require less rework than welds made without it. Beads smooth and free of inclusions.

  2. What's in a beach? Soil micromorphology of sediments from the Lower Paleolithic site of 'Ubeidiya, Israel.

    PubMed

    Mallol, Carolina

    2006-08-01

    A micromorphological study of archaeological sediments from the early Pleistocene site of 'Ubeidiya (Jordan Valley, Israel) was conducted to provide microenvironmental detail for the hominin occupation contexts and investigate site formation issues. Previous research shows that the hominin groups occupied the marshes and pebbly beaches at the shores of a lake during a regressive period, but given that some portions of the lithic and faunal assemblages are abraded and others fresh, there remains a question of whether the archaeological assemblages are in situ or reworked, and if reworked, by what mechanisms and from where. The rates of sedimentation within the regressive cycle, by which we can learn about the frequency and duration of exposed surfaces amenable for hominin occupation is also unknown. Finally, the artificial nature of some of the pebbly layers has been questioned. The micromorphological analysis yielded the identification of twelve microfacies; the majority of these represent fluvially derived floodplain soils or distal mudflow deposits, and a minor number are sediments of lacustrine origin: mudflats and shallow subaqueous sediments. These represent the natural habitats of the 'Ubeidiya hominins and might serve as a reference to similar contexts of other early hominin sites. The sedimentary model proposed here entails the rapid deposition of fluvially derived low-energy sediments at and around the shoreline, followed by prolonged periods of exposure, during which surfaces stabilized within a relatively wet, marshy environment. This interpretation suggests that the abraded portions of the archaeological assemblages are a result of prolonged surface exposure rather than high-energy transport from a distant source or to wave reworking at the shoreline, and supports the consideration of these assemblages as archaeological palimpsests, with locally reworked fresh and abraded elements. No micromorphological evidence supporting anthropogenic agency in the

  3. Accelerating patient-care improvement in the ED.

    PubMed

    Forrester, Nancy E

    2003-08-01

    Quality improvement is always in the best interest of healthcare providers. One hospital examined the patient-care delivery process used in its emergency department to determine ways to improve patient satisfaction while increasing the effectiveness and efficiency of healthcare delivery. The hospital used activity-based costing (ABC) plus additional data related to rework, information opportunity costs, and other effectiveness measures to create a process map that helped it accelerate diagnosis and improve redesign of the care process. PMID:12938618

  4. The impact of high-resolution biostratigraphy on reservoir prediction and basin history - A Barents Sea case study

    SciTech Connect

    Husmo, T. ); Hochuli, P. )

    1991-08-01

    The Hammerfest Basin is bounded by the Troms-Finnmark Platform to the south and the Loppa High to the north. Twenty-seven exploration wells have been drilled in the basin since 1980. The objective for most of these wells was Middle Jurassic fault blocks. Until recently little attention has been paid to the Upper Jurassic to Lower Cretaceous synrift sequence. The first well drilled on Block 7120/10 tested a rotated Jurassic fault block. This well, together with two wells in an adjacent block, penetrated thin Lower Cretaceous sands near the distal pinch-outs of fault wedges. Seismic data indicated that a basinal wedge of equivalent age was present on Block 7120/10. High risk was put on the presence of sand in this basinal wedge, and a detailed biostratigraphic analysis was performed on wells along the basin margin in order to determine the timing of erosion on the margin and whether the Jurassic-Triassic coarse clastics were present in the provenance area. The analysis separated reworked from in-situ palynomorph assemblages in the synrift succession in the analyzed wells. A clear inverted stratigraphy was displayed by the reworked palynomorphs. Furthermore, a dramatic increase in reworked palynomorphs. Furthermore, a dramatic increase in reworked palynomorphs was observed in all wells at the onset of Valanginian. In particular the presence of Nannoceratopsis gracilis suggested that shallow marine Jurassic clastics were eroded at this time. Sand presence was predicted for the basinal wedge. The understanding of the basin history was also improved. Well 71Z0/10-2 drilled summer 1990 proved the success of the reservoir prediction and hence the usefulness of incorporating biostratigraphy in the assessment.

  5. New Method for Updating Mean Time Between Failure for ISS Orbital Replaceable Units Consultation Report

    NASA Technical Reports Server (NTRS)

    Parsons, Vickie S.

    2009-01-01

    A request to conduct a peer review of the International Space Station (ISS) proposal to use Bayesian methodology for updating Mean Time Between Failure (MTBF) for ISS Orbital Replaceable Units (ORU) was submitted to the NASA Engineering and Safety Center (NESC) on September 20, 2005. The results were requested by October 20, 2005 in order to be available during the process of reworking the current ISS flight manifest. The results are included in this report.

  6. Coaly matter in a hydrothermal uranium deposit

    SciTech Connect

    Uspenskii, V.A.; Khaldei, A.E.; Kochenov, A.V.

    1986-09-01

    The behavior of high-carbon organic matter of a plant origin is studied as affected by the various superimposed processes. In stratiform ore placers that developed with the participation of oxygen-containing water, a correlation is observed between the oxidation degree of organic matter and its uranium contents. Coaly matter in steep metasomatically reworked zones with vein metallization is oxidized immediately at the contact with pitchblende microveinlets, apparently as a result of postmetallization radiolytic processes.

  7. Investigation of a fossil geothermal system, Hamblin-Cleopatra Volcano, Clark County, Nevada. Final technical report

    SciTech Connect

    Barker, D.S.

    1986-07-28

    The Hamblin-Cleopatra volcano, selected for study because erosion and fault displacement have exposed the entire volcanic succession, the intrusive core, a radial dike systems, and sedimentary and volcanic rocks that predate and postdate the volcano, was investigated to estimate the proportions of igneous materials forming lava flows, pyroclastic deposits, intrusive bodies, and reworked debris. Chemical changes in the magma throughout the active period of the volcano were documented. The geothermal system active within the pile after activity ceased was reconstructed. (ACR)

  8. Ruggedized Spectrometers Are Built for Tough Jobs

    NASA Technical Reports Server (NTRS)

    2015-01-01

    The Mars Curiosity Chemistry and Camera instrument, or ChemCam, analyzes the elemental composition of materials on the Red Planet by using a spectrometer to measure the wavelengths of light they emit. Principal investigator Roger Wiens worked with Ocean Optics, out of Dunedin, Florida, to rework the company's spectrometer to operate in cold and rowdy conditions and also during the stresses of liftoff. Those improvements have been incorporated into the firm's commercial product line.

  9. Solder Bonding for Power Transistors

    NASA Technical Reports Server (NTRS)

    Snytsheuvel, H. A.; Mandel, H.

    1985-01-01

    Indium solder boosts power rating and facilitates circuit changes. Efficient heat conduction from power transistor to heat sink provided by layer of indium solder. Low melting point of indium solder (141 degrees C) allows power transistor to be removed, if circuit must be reworked, without disturbing other components mounted with ordinary solder that melts at 181 degrees C. Solder allows devices operated at higher power levels than does conventional attachment by screws.

  10. Le domaine margino-littoral du Bénin (Golfe de Guinée - Afrique de l'Ouest): âge holocène et mise en place marine des ``Sables jaunes''

    NASA Astrophysics Data System (ADS)

    Lang, J.; Paradis, G.; Oyede, M.

    The formation "Sables jaunes" occurs along the littoral margin of the Benin. Their age, determined by means of Carbon 14, is comprised between 19573 ± 500 BP (DAK 207) and 2674 ± 120 BP (DAK 199). Their morphological and sedimentological characteristics lead to regard them as resulting from a marine sedimentation, then followed by an eolian reworking which affects only the upper part of the Sands.

  11. Controls on the composition of fluvial sands from a tropical weathering environment: sands of the Orinoco River drainage basin, Venezuela and Colombia

    USGS Publications Warehouse

    Johnsson, M.J.; Stallard, R.F.; Lundberg, N.

    1991-01-01

    On the alluvial plains of the western Llanos, storage of orogenically derived sediment allows time for substantial chemical weathering. Through reworking of the alluvial sequences, freshly eroded sediment is exchanged for older, compositionally more mature material. The chemically weathered component increases as rivers cross the Llanos, resulting in an increase in overall compositional maturity of bed-load sand away from the orogenic terranes. -from Authors

  12. Aeolian Processes and Landforms in River Valleys of Central Russian Plain in MIS 2

    NASA Astrophysics Data System (ADS)

    Matlakhova, Ekaterina

    2015-04-01

    Late Pleistocene terraces in river valleys of Central Russian Plain were subject to aeolian reworking after the alluvial sedimentation had finished. Severe natural conditions of LGM (cold and dry climate, scarce vegetation) contributed activation of aeolian processes. Ground water lowering because of deep pre-LGM incision of rivers made deep aeolian reworking possible at low hypsometric levels of valley bottom. We studied lithological structure of terraces in river valleys of Central Russian Plain. The key sites were located in Seim (the middle Dnieper catchment) and Khoper (the middle Don catchment) river valleys. Field data was combined with quartz grains morphoscopy technique (study of texture of sediment particles using scanning electron microscope). Wide participation of aeolian sediments in terrace deposits was detected. During this study a new technique of the distinguishing of short-term aeolian reworking of alluvial deposits using quartz grains morphoscopy technique was developed. The main problem of interpretation the results of quartz grains morphoscopy is that aeolian signals are sometimes not clear due to short duration of wind action over alluvial sands. However, detailed studies of the quartz grains surfaces under scanning electron microscope helped to solve this problem. We used scanning electron microscope JEOL JSM-661 LV and worked with magnification from ×160 to ×400 for whole grains and up to ×1800 for some parts of grains. Deep aeolian reworking of Late Pleistocene terrace alluvium in river valleys of Central Russian Plain during LGM led to the formation of aeolian covers on the terrace surfaces. Also there are many relict dunes on Late Pleistocene river terrace surfaces. Sometimes the development of aeolian processes could led to more significant changes in the shape of the valley and formation of aeolian aprons. The thickness of aeolian covers can reach 3-5 m or more. Due to this reason morphology and topography of river terraces could

  13. Bridging a High School Science Fair Experience with First Year Undergraduate Research: Using the E-SPART Analyzer to Determine Electrostatic Charge Properties of Compositionally Varied Rock Dust Particles as Terrestrial Analogues to Mars Materials

    NASA Technical Reports Server (NTRS)

    Scott, A. G.; Williams, W. J. W.; Mazumder, M. K.; Biris, A.; Srirama, P. K.

    2005-01-01

    NASA missions to Mars confirm presence of surficial particles, as well as dramatic periods of aeolian reworking. Dust deposition on, or infiltration into, exploration equipment such as spacecraft, robotic explorers, solar panel power supplies, and even spacesuits, can pose significant problems such as diminished power collection, short circuits / discharges, and added weight. We report results conducted initially as a science fair project and a study now part of a first year University undergraduate research experience.

  14. 23. Photocopied 1983, from original drawing (DP24800), Picatinny Arsenal, January ...

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

    23. Photocopied 1983, from original drawing (DP-24800), Picatinny Arsenal, January 27, 1937. BUILDING NO. 520, 'INSTALLATION OF CENTRIFUGALS FOR REWORKED SMOKELESS POWER, BUILDING NO. 520. JUDGING FROM THE BUILDING FABRIC INDICATED IN THE 'PLAN,' THIS EQUIPMENT WAS LOCATED IN THE EXTREME NORTHWEST CORNER OF BUILDING NO. 520 (COMPARE TO LOWER LEFT CORNER OF 'SECOND FLOOR PLAN' IN NJ-36-C-21). - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  15. Implications of Fail-Forward in an Online Environment under Alternative Grading Schemes

    ERIC Educational Resources Information Center

    Patron, Hilde; Smith, William J.

    2011-01-01

    The concept of fail-forward can be used as a teaching technique to motivate students to learn from their mistakes. For example, when students are allowed to re-work incorrect responses on a test for a partial grade they are failing-forward. In this paper we look at the effects of failing-forward on student effort in online learning environments.…

  16. Tooling Converts Stock Bearings To Custom Bearings

    NASA Technical Reports Server (NTRS)

    Fleenor, E. N., Jr.

    1983-01-01

    Technique for reworking stock bearings saves time and produces helicopter-rotor bearings ground more precisely. Split tapered ring at one end of threaded bolt expands to hold inside of inner race bearing assembly; nut, at other end of bolt, adjusts amount of spring tension. Piece of hardware grasps bearing firmly without interfering with grinding operation. Operation produces bearing of higher quality than commercially available bearings.

  17. Analysis of the production of ATLAS indium bonded pixel modules

    NASA Astrophysics Data System (ADS)

    Alimonti, G.; Andreazza, A.; Bulgheroni, A.; Corda, G.; Di Gioia, S.; Fiorello, A.; Gemme, C.; Koziel, M.; Manca, F.; Meroni, C.; Nechaeva, P.; Paoloni, A.; Rossi, L.; Rovani, A.; Ruscino, E.

    2006-09-01

    The ATLAS collaboration is currently building 1500 pixel modules using the indium bump bonding technique developed by SELEX Sistemi Integrati (former AMS). The indium deposition and flip-chip process are described together with an overview of the chip stripping machine that allows defective modules to be reworked. The production is half-way through at the time of this writing. This paper also discusses the problems encountered during production and the adopted solutions.

  18. Final report on Technical Demonstration and Economic Validation of Geothermally-Produced Electricity from Coproduced Water at Existing Oil/Gas Wells in Texas

    SciTech Connect

    Luchini, Chris B.

    2015-06-01

    The initial geothermal brine flow rate and temperature from the re-worked well were insufficient, after 2.5 days of flow testing, to justify advancing past Phase I of this project. The flow test was terminated less than 4 hours from the Phase I deadline for activity, and as such, additional flow tests of 2+ months may be undertaken in the future, without government support.

  19. Arctic Alaska’s Lower Cretaceous (Hauterivian and Barremian) mudstone succession—Linking lithofacies, texture, and geochemistry to marine processes

    USGS Publications Warehouse

    Keller, Margaret A.; Macquaker, Joe H.S.

    2015-01-01

    Our results document the variation in facies and textures of the Hauterivian and Barremian Lower Cretaceous mudstone succession of Arctic Alaska. Comparison of these characteristics to the products of modern processes on the North Slope of Alaska, in the Beaufort Sea, and elsewhere suggest that this succession formed primarily from depositional processes related to seasonal sea ice with intermittent fluvial-sourced sediment deposited by density currents and episodic erosion and reworking by storms and other currents.

  20. A method to translate between short-term fluvial processes on deltas and bulk volumes of channel and overbank deposits in the stratigraphic record

    NASA Astrophysics Data System (ADS)

    Martin, J. M.; Wickert, A. D.; Sheets, B. A.; Kelberer, M.; Kim, W.; Tal, M.; Paola, C.

    2009-12-01

    In the most general sense, the stratigraphy of river-dominated deltas can be classified into channel (sand) and overbank (mud) deposits. The relative proportions of these deposits are determined by the interplay of erosion and deposition between channels and the surrounding floodplain. A simple approach to the problem is to consider that (1) as river channels migrate and avulse across deltas, they remove previous deposits and replace them with channel sand bodies, and (2) overbank flow deposits mud on levees and floodplains. Here we propose a simple relationship between channel mobility and overbank aggradation rate to estimate the bulk proportions of channel sand and overbank mud deposits in the stratigraphic record. We measure the fraction of the delta surface that can be reworked by channels over the time it takes the surface to aggrade about one channel depth. We use this reworked fraction as the “rate” of production of channel deposits (and destruction of preexisting deposits). The mean aggradation rate of the delta surface is the production rate of overbank material. The rate relationship between reworking and delta aggradation provides a good prediction of the observed amounts of channel and overbank deposits in two experimental alluvial fan deltas. Lastly, we develop a scaling relationship between delta surface reworking rates and channel planform change. This is used to develop a direct relationship between channel mobility in modern field systems and their bulk channel - overbank deposit proportions. With additional work, we hope this type of analysis can be applied to determining probabilities of channel body connectivity, which is important for the extraction of subsurface reservoirs of water and hydrocarbons.

  1. 33. Photocopied 1983, from original drawing (DP49484), Picatinny Arsenal, November ...

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

    33. Photocopied 1983, from original drawing (DP-49484), Picatinny Arsenal, November 29, 1948. 'SMOKELESS POWDER Area: REWORK POWDER PROCESS FLOW DIAGRAM.' THE PROCESS DETAILED IN THIS DIAGRAM FROM THE POACHING HOUSE TO THE PACK HOUSE IS SUBSTANTIALLY THE SAME AS THE ONE FOR PRODUCING NEW POWDER FROM NITRATED COTTON. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  2. Model for sand hills development: Geometry, sediment supply and deposition, river systems and climatic implications

    SciTech Connect

    Pederson, D.T.; Wayne, W.J. . Geology Dept.); Davis, R.K. . Dept. of Earth Science)

    1992-01-01

    A model of sand hills development was formulated using processes occurring along the Dismal, Middle Loup and Platte rivers. A widespread alluvial fan blanketed by loess and sand dunes with interspersed lacustrine deposits is the product. The great arc of the sediment-supplying river indicates direction of wind transport. The key is a Platte-like river with flows near threshold capacity for transport of sediment from the river's source through the area during wetter climatic periods. During dryer periods stream channels fill with sediment pulses transported from mountain headwaters during snowmelt flood flows. The flood flows cause vertical reworking and sorting of the sediment. With waning flood flows many stream channels dry up leaving sediments vulnerable to wind erosion and transpore. With time stream channels become blocked by aggradation of sediment and dune formation diverting snowmelt floods to new paths in the forming dune field or around the margin of the new dune field. This process continues until increased flows with wetter comates are once again able to transport sediment through the area and erode a new river valley. Rivers rising in sand hills are groundwater fed, uniform in flow, and change only in response to climatic changes. They do not have the energy to rework the extensive gravel deposits of the Platte-like rivers and their net effect is to rework sediment above the coarser alluvium and transport the finer sediment out of the sand hills.

  3. The Manciano Sandstone: a shoreface deposit of Miocene basins of the Northern Apennines, Italy

    NASA Astrophysics Data System (ADS)

    Martini, I. P.; Cascella, A.; Rau, A.

    1995-09-01

    Well exposed, diamond-line cut, quarry-exposures of the Manciano Sandstone allow a detailed analysis of sandy, fossiliferous, nearshore deposits of the shelf of the Northern Apennines. The Manciano Sandstone is characterized by medium to very coarse, washed, fairly well sorted, lithic sandstone, with thin interlayers of sandy conglomerates. It displays two principal, rhythmically alternating sandy facies: (a) slightly burrowed (mostly Macaronichnus, Ophiomorpha, Skolithos) units, trough cross-bedded, locally showing possible tidal bundles with few whole Scutella (echinoid) shells reworked on foresets, or occasional large-scale (approximately 2 m) planar cross-bedded, bar-accretion units; and (b) slightly finer, darker-coloured reddish-brown sandstone units, heavily bioturbated ( Cruziana-Skolithos) ichnofauna) representing slightly more sheltered settings. Large oysters are present in near-living position in a few thin layers and, more commonly, as reworked, comminuted fragments in sandy layers. Many calcareous pebbles and oyster fragments are bored. Other fossils consist of echinoids ( Scutella), some balanids and reworked foraminifera and bryozoa. The Manciano sands were deposited primarily in a wave-dominated shoreface, containing migrating bars/ridges and affected by wave-induced, possibly tidal-enhanced currents. This tidal influence confirms the opening of the Miocene Apenninic Sea to oceans, both the developing Atlantic Ocean to the west and, through a long, narrow seaway, the Asian portion of the Tethys Sea to the east.

  4. A review of sediment budget imbalances along Fire Island, New York: Can nearshore geologic framework and patterns of shoreline change explain the deficit?

    USGS Publications Warehouse

    Hapke, Cheryl J.; Lentz, Erika E.; Gayes, Paul T.; McCoy, Clayton A.; Hehre, Rachel; Schwab, William C.; Williams, S. Jeffress

    2010-01-01

    Sediment budget analyses conducted for annual to decadal timescales report variable magnitudes of littoral transport along the south shore of Long Island, New York. It is well documented that the primary transport component is directed alongshore from east to west, but relatively little information has been reported concerning the directions or magnitudes of cross-shore components. Our review of budget calculations for the Fire Island coastal compartment (between Moriches and Fire Island Inlets) indicates an average deficit of 217,700 m3/y. Updrift shoreline erosion, redistribution of nourishment fills, and reworking of inner-shelf deposits have been proposed as the potential sources of additional sediment needed to rectify budget residuals. Each of these sources is probably relevant over various spatial and temporal scales, but previous studies of sediment texture and provenance, inner-shelf geologic mapping, and beach profile comparison indicate that reworking of inner-shelf deposits is the source most likely to resolve budget discrepancies over the broadest scales. This suggests that an onshore component of sediment transport is likely more important along Fire Island than previously thought. Our discussion focuses on relations between geomorphology, inner-shelf geologic framework, and historic shoreline change along Fire Island and the potential pathways by which reworked, inner-shelf sediments are likely transported toward the shoreline.

  5. Source areas of the Grybów sub-basin: micropaleontological, mineralogical and geochemical provenance analysis (Outer Western Carpathians, Poland)

    NASA Astrophysics Data System (ADS)

    Oszczypko-Clowes, Marta; Wójcik-Tabol, Patrycja; Płoszaj, Mateusz

    2015-12-01

    The Grybów Unit occurring in the Ropa tectonic window was the subject of micropaleontological and geochemical investigation. Studies, based on calcareous nannofossils, proved that the level of reworked microfossil is not higher than 22 % and it varies between two sections. Quantitative analyses of the reworked assemblages confirmed the domination of Cretaceous and Middle Eocene species. The Sub-Grybów Beds, Grybów Marl Formation and Krosno Beds were assigned to the Late Oligocene and represent the terminal flysch facies. Detrital material accumulated in the Oligocene sediments originated from the Marmarosh Massif, which is the eastern prolongation of the Fore-Magura Ridge. The microscopically obtained petrological features agree with the chemical composition of the samples. Mica flakes, rounded grains of glauconite, heavy mineral assemblage, including abraded grains of zircon, rutile and tourmaline as well as charred pieces of plant tissues are reworked components. Enrichment in zircon and rutile is confirmed geochemically by positive correlation between Zr and SiO2. Zr addition is illustrated on 10×Al2O3-Zr-200×TiO2 and Zr/Sc vs. Th/Sc diagrams. Interpretation of the A-CN-K diagram and variety of CIA and CPA values indicate that the source rocks were intensely weathered granite-type rocks.

  6. Eustatic, volcanic, and tectonic controls on redeposition of shallow-water carbonate: A reanalysis of Pacific DSDP examples

    SciTech Connect

    Dolan, J.F. )

    1990-05-01

    On the basis of comparisons between eustatic sea level curves and occurrences of displaced shallow marine carbonate sediment in deep water Pacific DSDP (Deep Sea Drilling Project) cores, several previous workers have proposed that most displaced neritic carbonate is redeposited in the deep sea during eustatic sea level lowstands in a manner similar to siliciclastic sediment. However, reanalysis of these same DSDP data indicates a much more complex set of controls on redeposition including eustatic, volcanic, and tectonic effects. Of the 43 occurrences identified in 20 DSDP sites, eight (including all occurrences of true allodapic calcarenites) were deposited either during eustatic highstands or immediately after cessation of island-building volcanism; establishment of a shallow-water source area probably represents the dominant control on this type of deposition. Twenty-three other occurrences contain volcanic detritus mixed with minor amounts of reworked carbonate. Of these occurrences eight contain volcaniclastic sediment and exhibit no clear correlation with sea level, indicating probable redeposition of shelf carbonate during volcanic events as a result of either gravitational or seismic instability of the shelf. In contrast, the 15 other mixed volcanic/carbonate occurrences represent lowstand deposit and contain epiclastic volcanic detritus, suggesting lowstand erosion of mixed volcanic/carbonate shelf sediments. Five other lowstand occurrences contain only reworked carbonate sediment and probably record either continued outer shelf/slope lowstand carbonate deposition or minor mechanical erosion of shelf carbonate. Six occurrences contain only reworked Inoceramus fragments, which are not necessarily indicative of a shelf source area.

  7. Flood basalt volcanism, end-Triassic deforestation, and intense weathering of soils and bedrock

    NASA Astrophysics Data System (ADS)

    van de Schootbrugge, Bas; Lindström, Sofie; Pross, Jörg; Dybkjaer, Karen; Heunisch, Carmen; Petschick, Rainer; Lyachenko, Lara; Püttmann, Willhelm; Oschmann, Wolfgang

    2010-05-01

    The end-Triassic mass-extinction on land was characterized by the widespread dieback of gymnospermous forests across the northern hemisphere and their transient replacement by ferns and fern allies. These floral changes are thought to have been triggered by the eruption of 2 million kubic kilometers of basalt belonging to the Central Atlantic Magmatic Province, releasing noxious and greenhouse gases into the atmosphere. Here, we provide evidence for the dramatic consequences of deforestation during the latest Triassic in the form of intense erosion of soils and the weathering of bedrock across northwest Europe. Together with abundant fern spores, representing a pioneer vegetation, we find enhanced levels of kaolinite in the boundary beds, indicating chemical weathering. In palynological samples from cores that span the Triassic-Jurassic boundary in Sweden, Denmark and Germany we notice abundant reworked Carboniferous spores, reworked Silurian and Devonian acritarchs, and mycorrhizal fungal remains. The latter suggest soils were being eroded across the Germanic Basin. In Northern Germany, Denmark, and Sweden, Paleozoic palynomorphs were reworked from the Fennoscandian Shield, while in Southern Germany such palynomorphs may have originated from the Bohemian Massive. The contemporaneous, intense weathering of bed rocks and soil erosion on landmasses during the latest Triassic was likely a direct result of deforestation, but was probably exacerbated by acid rain and greenhouse warming due to the emission of sulfur and carbon dioxide from volcanic activity.

  8. New allocyclic dimensions in a prograding carbonate bank: Evidence for eustatic, tectonic, and paleoceanographic control (late Neogene, Bahamas)

    USGS Publications Warehouse

    Lidz, B.H.; McNeill, D.F.

    1997-01-01

    The deep-sea record, examined recently for the first time in a shallow-depocenter setting, has unveiled remarkable evidence for new sedimentary components and allocyclic complexity in a large, well-studied carbonate bank, the western Great Bahama Bank. The evidence is a composite foraminiferal signature - Paleocene to early Miocene (allogenic or reworked) and late Miocene to late Pliocene (host) planktic taxa, and redeposited middle Miocene shallow benthic faunas. Ages of the oldest and youngest planktic groups range from ??? 66 to ??? 2 Ma. The reworked and redeposited taxa are a proxy for significant sediment components that otherwise have no lithofacies or seismic resolution. The composite signature, reinforced by a distinctive distribution of the reworked and redeposited faunas, documents a much more complex late Neogene depositional system than previously known. The system is more than progradational. The source sequences that supplied the constituent bank-margin grains formed at different water depths and over hundreds of kilometers and tens of millions of years apart. New evidence from the literature and from data obtained during Ocean Drilling Program (OOP) Leg 166 in the Santaren Channel (Bahamas) support early interpretations based on the composite fossil record and provide valuable new dimensions to regional allocyclicity. The middle Miocene taxa were confined to the lower part of the section by the latest Miocene-earliest Pliocene(?) lowstand of sea level. An orderly occurrence of the allogenic taxa is unique to the global reworked geologic record and appears to have been controlled by a combination of Paleogene-early Neogene tectonics at the source, eustatic changes, and late Neogene current activity at the source and across the bank. The allogenic taxa expand the spatial and temporal range of information in the northern Bahamas by nearly an order of magnitude. In essence, some of the major processes active in the region during ??? 64 m.y. of the

  9. Evolution of the African continental crust as recorded by U-Pb, Lu-Hf and O isotopes in detrital zircons from modern rivers

    NASA Astrophysics Data System (ADS)

    Iizuka, Tsuyoshi; Campbell, Ian H.; Allen, Charlotte M.; Gill, James B.; Maruyama, Shigenori; Makoka, Frédéric

    2013-04-01

    To better understand the evolutionary history of the African continental crust, a combined U-Pb, Lu-Hf and O isotopic study has been carried out by in situ analyses of approximately 450 detrital zircon grains from the Niger, Nile, Congo, Zambezi and Orange Rivers. The U-Pb isotopic data show age peaks at ca. 2.7, 2.1-1.8, 1.2-1.0, ca. 0.8, 0.7-0.5 and ca. 0.3 Ga. These peaks, with the exception of the one at ca. 0.8 Ga, correspond with the assembly of supercontinents. Furthermore, the detrital zircons that crystallized during these periods of supercontinent assembly have dominantly non-mantle-like O and Hf isotopic signatures, in contrast to the ca. 0.8 Ga detrital zircons which have juvenile characteristics. These data can be interpreted as showing that continental collisions during supercontinent assembly resulted in supermountain building accompanied by remelting of older continental crust, which in turn led to significant erosion of young igneous rocks with non-mantle-like isotopic signatures. Alternatively, the data may indicate that the major mode of crustal development changed during the supercontinent cycle: the generation of juvenile crust in extensional settings was dominant during supercontinent fragmentation, whereas the stabilization of the generated crust via crustal accretion and reworking was important during supercontinent assembly. The Lu-Hf and O isotope systematics indicate that terreigneous sediments could attain elevated 18O/16O via prolonged sediment-sediment recycling over long crustal residence time, and also that reworking of carbonate and chert which generally have elevated 18O/16O and low Hf contents is minor in granitoid magmatism. The highest 18O/16O in detrital zircon abruptly increased at ca. 2.1 Ga and became nearly constant thereafter. This indicates that reworking of mature sediments increased abruptly at that time, probably as a result of a transition in the dynamics of either granitoid crust formation or sedimentary evolution

  10. On the origin of a phosphate enriched interval in the Chattanooga Shale (Upper Devonian) of Tennessee-A combined sedimentologic, petrographic, and geochemical study

    NASA Astrophysics Data System (ADS)

    Li, Yifan; Schieber, Juergen

    2015-11-01

    The Devonian Chattanooga Shale contains an uppermost black shale interval with dispersed phosphate nodules. This interval extends from Tennessee to correlative strata in Kentucky, Indiana, and Ohio and represents a significant period of marine phosphate fixation during the Late Devonian of North America. It overlies black shales that lack phosphate nodules but otherwise look very similar in outcrop. The purpose of this study is to examine what sets these two shales apart and what this difference tells us about the sedimentary history of the uppermost Chattanooga Shale. In thin section, the lower black shales (PBS) show pyrite enriched laminae and compositional banding. The overlying phosphatic black shales (PhBS) are characterized by phosbioclasts, have a general banded to homogenized texture with reworked layers, and show well defined horizons of phosphate nodules that are reworked and transported. In the PhBS, up to 8000 particles of P-debris per cm2 occur in reworked beds, whereas the background black shale shows between 37-88 particles per cm2. In the PBS, the shale matrix contains between 8-16 phosphatic particles per cm2. The shale matrix in the PhBS contains 5.6% inertinite, whereas just 1% inertinite occurs in the PBS. The shale matrix in both units is characterized by flat REE patterns (shale-normalized), whereas Phosbioclast-rich layers in the PhBS show high concentrations of REEs and enrichment of MREEs. Negative Ce-anomalies are common to all samples, but are best developed in association with Phosbioclasts. Redox-sensitive elements (Co, U, Mo) are more strongly enriched in the PBS when compared to the PhBS. Trace elements associated with organic matter (Cu, Zn, Cd, Ni) show an inverse trend of enrichment. Deposited atop a sequence boundary that separates the two shale units, the PhBS unit represents a transgressive systems tract and probably was deposited in shallower water than the underlying PBS interval. The higher phosphate content in the PhBS is

  11. Tides and deltaic morphodynamics

    NASA Astrophysics Data System (ADS)

    Plink-Bjorklund, Piret

    2016-04-01

    Tide-dominated and tide-influenced deltas are not widely recognized in the ancient record, despite the numerous modern and Holocene examples, including eight of the twelve modern largest deltas in the world, like the Ganges-Brahmaputra, Amazon, Chang Jiang, and Irrawadi. Furthermore, tide-dominated or tide-influenced deltas are suggested to be more common in inner-shelf or embayment settings rather than close to or at a shelf edge, primarily because wave energy is expected to be higher and tidal energy lower in outer shelf and shelf-edge areas. Thus, most shelf-edge deltas are suggested to be fluvial or wave dominated. However, there are ancient examples of tide-influenced shelf-edge deltas, indicating that the controls on tidal morphodynamics in deltas are not yet well understood. This paper asks the following questions: (1) How do tides influence delta deposition, beyond creating recognizable tidal facies? (2) Does tidal reworking create specific geometries in delta clinoforms? (3) Does tidal reworking change progradation rates of deltas? (4) Is significant tidal reworking of deltas restricted to inner-shelf deltas only? (5) What are the conditions at which deltas may be tidally influenced or tide-dominated in outer-shelf areas or at the shelf edge? (6) What are the main morphodynamic controls on the degree of tidal reworking of deltas? The paper utilizes a dataset of multiple ancient and modern deltas, situated both on the shelf and shelf edge. We show that beyond the commonly recognized shore-perpendicular morphological features and the recognizable tidal facies, the main effects of tidal reworking of deltas are associated with delta clinoform morphology, morphodynamics of delta lobe switching, delta front progradation rates, and the nature of the delta plain. Strong tidal influence is here documented to promote subaqueous, rapid progradation of deltas, by efficiently removing sediment from river mouth and thus reducing mouth bar aggradation and fluvial delta

  12. Sulfur sources of sedimentary "buckshot" pyrite in the Auriferous Conglomerates of the Mesoarchean Witwatersrand and Ventersdorp Supergroups, Kaapvaal Craton, South Africa

    NASA Astrophysics Data System (ADS)

    Guy, B. M.; Ono, S.; Gutzmer, J.; Lin, Y.; Beukes, N. J.

    2014-08-01

    Large rounded pyrite grains (>1 mm), commonly referred to as "buckshot" pyrite grains, are a characteristic feature of the auriferous conglomerates (reefs) in the Witwatersrand and Ventersdorp supergroups, Kaapvaal Craton, South Africa. Detailed petrographic analyses of the reefs indicated that the vast majority of the buckshot pyrite grains are of reworked sedimentary origin, i.e., that the pyrite grains originally formed in the sedimentary environment during sedimentation and diagenesis. Forty-one of these reworked sedimentary pyrite grains from the Main, Vaal, Basal, Kalkoenkrans, Beatrix, and Ventersdorp Contact reefs were analyzed for their multiple sulfur isotope compositions (δ34S, Δ33S, and Δ36S) to determine the source of the pyrite sulfur. In addition, five epigenetic pyrite samples (pyrite formed after sedimentation and lithification) from the Middelvlei and the Ventersdorp Contact reefs were measured for comparison. The δ34S, Δ33S, and Δ36S values of all 41 reworked sedimentary pyrite grains indicate clear signatures of mass-dependent and mass-independent fractionation and range from -6.8 to +13.8 ‰, -1.7 to +1.7 ‰, and -3.9 to +0.9 ‰, respectively. In contrast, the five epigenetic pyrite samples display a very limited range of δ34S, Δ33S, and Δ36S values (+0.7 to +4.0 ‰, -0.3 to +0.0 ‰. and -0.3 to +0.1 ‰, respectively). Despite the clear signatures of mass-independent sulfur isotope fractionation, very few data points plot along the primary Archean photochemical array suggesting a weak photolytic control over the data set. Instead, other factors command a greater degree of influence such as pyrite paragenesis, the prevailing depositional environment, and non-photolytic sulfur sources. In relation to pyrite paragenesis, reworked syngenetic sedimentary pyrite grains (pyrite originally precipitated along the sediment-water interface) are characterized by negative δ34S and Δ33S values, suggesting open system conditions with respect

  13. Selection and stability of quantitative stratigraphic age models: Plio-Pleistocene glaciomarine sediments in the ANDRILL 1B drillcore, McMurdo Ice Shelf

    NASA Astrophysics Data System (ADS)

    Cody, Rosemary; Levy, Richard; Crampton, James; Naish, Timothy; Wilson, Gary; Harwood, David

    2012-10-01

    Interpretation of glacimarine sedimentary records from Antarctic shelf drillholes has been hampered by the ambiguous age of strata where erosional unconformities and coarse diamictite deposits truncate or omit the magnetostratigraphic and biostratigraphic units used for correlation. However, new quantitative biostratigraphic techniques enable the correlation of sparse, incomplete, and often reworked Plio-Pleistocene records of Ross Sea fossil diatom flora with the more extensively documented but potentially diachronous offshore history of species' first and last appearance datums (FADs and LADs). The approach uses comprehensive regional databases of fossil records and computer-automated search algorithms to find the multidimensional line of correlation (LOC) that best fits local observations, and to identify regionally isochronous biostratigraphic markers. Different model configurations can be used to produce LOCs that represent alternative working hypotheses regarding reworking and other sources of misfit in the biostratigraphic record, and that together provide an envelope of uncertainty for age interpretation. An integrated, quantitative chronostratigraphic model for the ANDRILL-1B drillcore was developed iteratively: an initial age model was constructed solely from preliminary on-ice observations of fossil diatom highest and lowest occurrences (HOs and LOs) and their correlation with a database of other local event records from 24 DVDP, CIROS, and IODP drillcore sections. The model was subsequently updated as off-ice work yielded additional biostratigraphic marker events and revised event horizons, Ar/Ar ages for volcanic material, better-constrained magnetostratigraphic interpretation, and refinements to computational/analytical methodology. The current quantitative biostratigraphic age model for the AND-1B hole integrates the local ranges of 29 diatom taxa, five dated volcanic samples, and independently constrained ages of five paleomagnetic reversals. During

  14. New geochronologic and stratigraphic evidence confirms the paleocene age of the dinosaur-bearing ojo alamo sandstone and animas formation in the San Juan Basin, New Mexico and Colorado

    USGS Publications Warehouse

    Fassett, J.E.

    2009-01-01

    Dinosaur fossils are present in the Paleocene Ojo Alamo Sandstone and Animas Formation in the San Juan Basin, New Mexico, and Colorado. Evidence for the Paleo-cene age of the Ojo Alamo Sandstone includes palynologic and paleomagnetic data. Palynologic data indicate that the entire Ojo Alamo Sandstone, including the lower dinosaur-bearing part, is Paleocene in age. All of the palynomorph-productive rock samples collected from the Ojo Alamo Sandstone at multiple localities lacked Creta-ceous index palynomorphs (except for rare, reworked specimens) and produced Paleocene index palynomorphs. Paleocene palynomorphs have been identified strati-graphically below dinosaur fossils at two separate localities in the Ojo Alamo Sand-stone in the central and southern parts of the basin. The Animas Formation in the Colorado part of the basin also contains dinosaur fossils, and its Paleocene age has been established based on fossil leaves and palynology. Magnetostratigraphy provides independent evidence for the Paleocene age of the Ojo Alamo Sandstone and its dinosaur-bearing beds. Normal-polarity magnetochron C29n (early Paleocene) has been identified in the Ojo Alamo Sandstone at six localities in the southern part of the San Juan Basin. An assemblage of 34 skeletal elements from a single hadrosaur, found in the Ojo Alamo Sandstone in the southern San Juan Basin, provided conclusive evidence that this assemblage could not have been reworked from underlying Cretaceous strata. In addition, geochemical studies of 15 vertebrate bones from the Paleocene Ojo Alamo Sandstone and 15 bone samples from the underlying Kirtland Formation of Late Creta-ceous (Campanian) age show that each sample suite contained distinctly different abundances of uranium and rare-earth elements, indicating that the bones were miner-alized in place soon after burial, and that none of the Paleocene dinosaur bones ana-lyzed had been reworked. ?? U.S. Geological Survey, Public Domain April 2009.

  15. Co-evolution of Riparian Vegetation and Channel Dynamics in an Aggrading Braided River System, Mount Pinatubo, Philippines

    NASA Astrophysics Data System (ADS)

    Gran, K. B.; Michal, T.

    2014-12-01

    Increased bank stability by riparian vegetation in braided rivers can decrease bed reworking rates and focus the flow. The magnitude of influence and resulting channel morphology are functions of vegetation strength vs. channel dynamics, a concept encapsulated in a dimensionless ratio between timescales for vegetation growth and channel reworking known as T*. We investigate this relationship in an aggrading braided river at Mount Pinatubo, Philippines, and compare results to numerical and physical models. Gradual reductions in post-eruption sediment loads have reduced bed reworking rates, allowing vegetation to persist year-round and impact channel dynamics on the Pasig-Potrero and Sacobia Rivers. From 2009-2011, we collected data detailing vegetation extent, type, density, and root strength. Incorporating these data into RipRoot and BSTEM models shows cohesion due to roots increased from zero in unvegetated conditions to >10.2 kPa in densely-growing grasses. Field-based parameters were incorporated into a cellular model comparing vegetation growth and sediment mobility effects on braided channel dynamics. The model shows that both low sediment mobility and high vegetation strength lead to less active systems, reflecting trends observed in the field. An estimated T* between 0.8 - 2.3 for the Pasig-Potrero River suggests channels were mobile enough to maintain the braidplain width clear of vegetation and even experience slight gains in area through annual removal of existing vegetation. However, persistent vegetation focused flow and thus aggradation over the unvegetated fraction of braidplain, leading to an aggradational imbalance and transition to a more avulsive state. While physical models predict continued narrowing of the active braidplain as T* declines, the future trajectory of channel-vegetation interactions at Pinatubo as sedimentation rates decline appears more complicated due to strong seasonal variability in precipitation and sediment loads. By 2011

  16. ESR and U-series analyses of enamel and dentine fragments of the Banyoles mandible.

    PubMed

    Grün, Rainer; Maroto, Julià; Eggins, Stephen; Stringer, Chris; Robertson, Steve; Taylor, Lois; Mortimer, Graham; McCulloch, Malcolm

    2006-03-01

    The Banyoles mandible presents a puzzle. Its anatomy has been described as pre-Neandertal, but the travertine in which it was found has been dated to 45,000 +/- 4000 years. By this time, any pre-Neandertals had supposedly been absent from the European fossil record for more than 100,000 years. It was therefore proposed that the age of the travertine may represent a minimum age estimate, with the mandible possibly having been reworked from older deposits. We carried out a non-destructive ESR analysis of an enamel fragment removed from a molar and performed a series of in situ laser ablation U-series analyses on dentine fragments adjacent to the enamel piece. The analyses resulted in an apparent combined ESR-U-series age of 66,000 +/- 7000 years. The encasing travertine matrix was also analyzed for U-series isotopes and showed signs of U-mobilization. It cannot be excluded that the travertine matrix is older than the previously determined age. If the mandible was not reworked, then the combined ESR-U-series result on the tooth enamel would give its best age estimate. If, on the other hand, the mandible was reworked from another deposit, the actual ESR-U-series age will depend on the external dose rate from the previous matrix and the depth of its burial, which controls the degree of the attenuation of the cosmic dose rate over time. Considering a range of possible burial histories, the mean age of the mandible would lie somewhere between the combined ESR-U-series age and the previously determined age of the travertine matrix. Regarding the morphology of the mandible, a review of its features in the context of larger Neandertal samples indicates that the anatomy of the specimen is not incompatible with such a young age determination, although it further highlights morphological variation in the late Neandertal sample. PMID:16364406

  17. The variety of shelf sand bodies within the transgressive systems tract as illustrated by the high-resolution sequence stratigraphy of Late Wisconsin/Holocene deposits from the continental shelf of Texas

    SciTech Connect

    Bartek, L.R.; Anderson, J.B.; Thomas, M.A.; Siringan, F.P. )

    1990-05-01

    An ongoing investigation of the high-resolution sequence stratigraphy of the Texas continental shelf indicates that a variety of shelf sand bodies formed during the late Wisconsinan-Holocene transgression. Episodic variations in eustasy and sediment supply have apparently caused the formation of backstepping parasequences (bayhead delta progradational units bounded by flooding surfaces) within the incised valley systems of the continental shelf. The Trinity/Sabine incised valley systems contain isolated sand bodies within the dip-aligned incised valleys whereas the Brazos/Colorado incised valley systems apparently contain broad sheetlike sand bodies. Sabine Bank is also associated with the Trinity/Sabine incised valley systems. The Sabine Bank is thought to be comprised of either reworked, overstepped shoreline sands or sand that was mined from the incised valley system and reworked into a strike-aligned sand body as the shoreface migrated across the shelf during the transgression. Transgressed wave-dominated deltas are another important type of shelf sand body in the transgressive systems tract of the Texas continental shelf. Sediment texture maps and high-resolution seismic data suggest that strike-aligned sand bodies lying offshore of the modern Brazos delta are modified remnants of ancestral Brazos and Colorado river deltas. These delta deposits may have been isolated on the shelf during intervals when eustatic rise was more rapid. Seismic data indicate that the upper part of these deltaic deposit was reworked into strike-aligned shelf sand bodies whereas the lower portion was preserved in place. The relative significance of storms in both sourcing and altering shelf sand bodies in this setting is still being addressed. Two hurricanes struck the study area during the past summer and post-storm surveys were conducted.

  18. Sedimentary processes in modern and ancient oceanic arc settings: evidence from the Jurassic Talkeetna Formation of Alaska and the Mariana and Tonga Arcs, western Pacific

    USGS Publications Warehouse

    Draut, Amy E.; Clift, Peter D.

    2006-01-01

    Sediment deposited around oceanic volcanic ares potentially provides the most complete record of the tectonic and geochemical evolution of active margins. The use of such tectonic and geochemical records requires an accurate understanding of sedimentary dynamics in an arc setting: processes of deposition and reworking that affect the degree to which sediments represent the contemporaneous volcanism at the time of their deposition. We review evidence from the modern Mariana and Tonga arcs and the ancient arc crustal section in the Lower Jurassic Talkeetna Formation of south-central Alaska, and introduce new data from the Mariana Arc, to produce a conceptual model of volcaniclastic sedimentation processes in oceanic arc settings. All three arcs are interpreted to have formed in tectonically erosive margin settings, resulting in long-term extension and subsidence. Debris aprons composed of turbidites and debris flow deposits occur in the immediate vicinity of arc volcanoes, forming relatively continuous mass-wasted volcaniclastic records in abundant accommodation space. There is little erosion or reworking of old volcanic materials near the arc volcanic front. Tectonically generated topography in the forearc effectively blocks sediment flow from the volcanic front to the trench; although some canyons deliver sediment to the trench slope, most volcaniclastic sedimentation is limited to the area immediately around volcanic centers. Arc sedimentary sections in erosive plate margins can provide comprehensive records of volcanism and tectonism spanning < 10 My. The chemical evolution of a limited section of an oceanic arc may be best reconstructed from sediments of the debris aprons for intervals up to ~ 20 My but no longer, because subduction erosion causes migration of the forearc basin crust and its sedimentary cover toward the trench, where there is little volcaniclastic sedimentation and where older sediments are dissected and reworked along the trench slope.

  19. Long-term environmental and health implications of morphological change and sediment transport with respect to contaminants

    NASA Astrophysics Data System (ADS)

    Sneddon, Christopher; Copplestone, David; Tyler, Andrew; Hunter, Peter; Smith, Nick

    2014-05-01

    The EPSRC-funded Adaptation and Resilience of Coastal Energy Supply (ARCoES) project encompasses four research strands, involving 14 institutions and six PhD studentships. ARCoES aims to determine the threats posed to future energy generation and the distribution network by flooding and erosion, changing patterns of coastal sedimentation, water temperature and the distribution of plants and animals in the coastal zone. Whilst this research has direct benefits for the operation of coastal power stations, ARCoES aims to have a wider stakeholder engagement through assessing how the resilience of coastal communities may be altered by five hundred years of coastal evolution. Coastal evolution will have substantial implications for the energy sector of the North West of England as former waste storage sites are eroded and remobilised within the intertidal environment. The current intertidal environmental stores of radioactivity will also experience reworking as ocean chemistry changes and saltmarsh chronologies are reworked in response to rising sea levels. There is a duel requirement to understand mass sediment movement along the North West coast of England as understanding the sediment transport dynamics is key to modelling long term coastal change and understanding how the environmental store of radioactivity will be reworked. The University of Stirling is researching the long-term environmental and health implications of remobilisation and transport of contaminated sediments around the UK coastline. Using a synergy of hyperspectral and topographic information the mobilisation of sediment bound contaminants within the coastal environment will be investigated. Potential hazards posed by contaminants are determined by a set of environmental impact test criteria which evaluate the bio-accessibility and ionising dose of contaminants. These test criteria will be used to comment on the likely environmental impact of modelled sediment transport and anticipated changes in

  20. Knowledge Evolution in Distributed Geoscience Datasets and the Role of Semantic Technologies

    NASA Astrophysics Data System (ADS)

    Ma, X.

    2014-12-01

    Knowledge evolves in geoscience, and the evolution is reflected in datasets. In a context with distributed data sources, the evolution of knowledge may cause considerable challenges to data management and re-use. For example, a short news published in 2009 (Mascarelli, 2009) revealed the geoscience community's concern that the International Commission on Stratigraphy's change to the definition of Quaternary may bring heavy reworking of geologic maps. Now we are in the era of the World Wide Web, and geoscience knowledge is increasingly modeled and encoded in the form of ontologies and vocabularies by using semantic technologies. Accordingly, knowledge evolution leads to a consequence called ontology dynamics. Flouris et al. (2008) summarized 10 topics of general ontology changes/dynamics such as: ontology mapping, morphism, evolution, debugging and versioning, etc. Ontology dynamics makes impacts at several stages of a data life cycle and causes challenges, such as: the request for reworking of the extant data in a data center, semantic mismatch among data sources, differentiated understanding of a same piece of dataset between data providers and data users, as well as error propagation in cross-discipline data discovery and re-use (Ma et al., 2014). This presentation will analyze the best practices in the geoscience community so far and summarize a few recommendations to reduce the negative impacts of ontology dynamics in a data life cycle, including: communities of practice and collaboration on ontology and vocabulary building, link data records to standardized terms, and methods for (semi-)automatic reworking of datasets using semantic technologies. References: Flouris, G., Manakanatas, D., Kondylakis, H., Plexousakis, D., Antoniou, G., 2008. Ontology change: classification and survey. The Knowledge Engineering Review 23 (2), 117-152. Ma, X., Fox, P., Rozell, E., West, P., Zednik, S., 2014. Ontology dynamics in a data life cycle: Challenges and recommendations

  1. Tocuila Mammoths, Basin of Mexico: Late Pleistocene-Early Holocene stratigraphy and the geological context of the bone accumulation

    NASA Astrophysics Data System (ADS)

    Gonzalez, Silvia; Huddart, David; Israde-Alcántara, Isabel; Dominguez-Vazquez, Gabriela; Bischoff, James

    2014-07-01

    We report new stratigraphic, tephrochronology and dating results from the Tocuila Mammoth site in the Basin of Mexico. At the site there is evidence for a thin meteorite airburst layer dated between 10,878 and 10,707 cal BC at the onset of the Younger Dryas (YD) cool period. The Upper Toluca Pumice (UTP) tephra marker, caused by a Plinian eruption of the Nevado de Toluca volcano, dated from 10,666 to 10,612 cal BC, is above that layer. The eruption must have caused widespread environmental disruption in the region with evidence of extensive reworking and channelling by the Lake Texcoco shoreline and contributed to the widespread death and/or extinction of megafaunal populations, as suggested by earlier authors, but the new work reinforces the view that both catastrophic events must have caused large environmental disruption in a short time period of around two hundred years. There is no evidence for megafauna (mammoths, sabre toothed cats, camels, bison, glyptodonts) after the UTP volcanic event and subsequent lahars in the Basin of Mexico. At Tocuila, although there are some in situ tephra markers in nearshore lake sediments, such as the Great Basaltic Ash (GBA) and the UTP Ash, there is evidence of much reworking of several tephra populations in various combinations. The mammoth bone accumulation is reworked in a lahar sequence (volcanic mudflow) derived from several source sediments but associated with the major UTP Plinian eruption. Paleoindian populations were also present in the Basin of Mexico during the YD period, where several Paleoindian skeletons were found associated with the UTP ash deposits, e.g. Metro Man, Chimalhuacan Man and Tlapacoya Man.

  2. Sedimentology of Permian upper part of the Minnelusa Formation, eastern Powder River basin, Wyoming, and a comparison to the subsurface

    SciTech Connect

    Schenk, C.J.; Schmoker, J.W.; Fox, J.E.

    1993-04-01

    Outcrops of the Permian upper part of the Minnelusa Formation near Beulah, Wyoming consist of dolomite, gypsum, and sandstone units deposited in transgressive-regressive cycles. Three depositional cycles are partly exposed in the Simons Ranch anticline near Beulah, and provide an opportunity to view fades of the upper Minnelusa Formation in three dimensions. The cycles observed in outcrop were informally labelled cycle 1, cycle 2, and cycle 3 in ascending stratigraphic order. Cycle 2 contains a basal, laterally extensive sabkha sandstone and an overlying, laterally restricted sandstone that represents a preserved eolian-dune complex. The eolian-dune sandstone of cycle 2 was partially reworked during the marine transgression that initiated cycle 3. The eolian-dune deposit grades laterally into an apron of contorted and massive-bedded sandstones that formed as water-saturated sands liquified and slumped from the margins of the eolian dune. The partially reworked eolian-dune topography was covered by gypsum beds of cycle 3. The sandstone of cycle 3 is interpreted as a laterally continuous sabkha sandstone. West Mellott field (secs. 8, 9, T52N, R68W) represents a subsurface example of the facies and facies relationships observed in outcrop. The eolian-dune sandstone of the C cycle, which was partially reworked by the transgression of the B cycle, produces oil at West Mellott. The draping of dolomite and anhydrite of the B cycle on the eolian-dune sandstone of the C cycle is analogous to the draping of gypsum on dune sand in cycle 2 in outcrop.

  3. Alignment performance monitoring for ASML systems

    NASA Astrophysics Data System (ADS)

    Chung, Woong-Jae; Temchenko, Vlad; Hauck, Tarja; Schmidt, Sebastian

    2006-03-01

    In today's semiconductor industry downscaling of the IC design puts a stringent requirement on pattern overlay control. Tighter overlay requirements lead to exceedingly higher rework rates, meaning additional costs to manufacturing. Better alignment control became a target of engineering efforts to decrease rework rate for high-end technologies. Overlay performance is influenced by known parameters such as "Shift, Scaling, Rotation, etc", and unknown parameters defined as "Process Induced Variation", which are difficult to control by means of a process automation system. In reality, this process-induced variation leads to a strong wafer to wafer, or lot to lot variation, which are not easy to detect in the mass-production environment which uses sampling overlay measurements for only several wafers in a lot. An engineering task of finding and correcting a root cause for Process Induced Variations of overlay performance will be greatly simplified if the unknown parameters could be tracked for each wafer. This paper introduces an alignment performance monitoring method based on analysis of automatically generated "AWE" files for ASML scanner systems. Because "AWE" files include alignment results for each aligned wafer, it is possible to use them for monitoring, controlling and correcting the causes of "process induced" overlay performance without requiring extra measurement time. Since "AWE" files include alignment information for different alignment marks, it is also possible to select and optimize the best alignment recipe for each alignment strategy. Several case studies provided in our paper will demonstrate how AWE file analysis can be used to assist engineer in interpreting pattern alignment data. Since implementing our alignment data monitoring method, we were able to achieve significant improvement of alignment and overlay performance without additional overlay measurement time. We also noticed that the rework rate coming from alignment went down and

  4. Fan-surface dynamics and biogenic calcrete development: Interactions during ultimate phases of fan evolution in the semiarid SE Spain (Murcia)

    NASA Astrophysics Data System (ADS)

    Alonso-Zarza, Ana M.; Silva, Pablo G.; Goy, José L.; Zazo, Cari

    1998-08-01

    Pleistocene alluvial fan surfaces of the Campo de Cartagena-Mar Menor Basin (Murcia, SE Spain) are capped by thick mature calcretes. Calcrete profiles consist mainly of six different horizons: prismatic, chalky, nodular, massive, laminar and coated-gravels. Petrographic study of the calcretes has shown the occurrence of features such as alveolar septal structures, calcified filaments, coated grains, spherulites, calcified root cells and calcispheres that indicate the biogenic origin of the calcretes, mainly induced by plant root related microbial activity. The calcretes studied were formed initially in the soil and represented the K horizon. Development of the calcrete profiles took place in six main stages and was driven by multiple phases of soil formation, erosion and reworking. The relationships between these processes caused the formation of different calcrete profiles in proximal and distal fan areas. In the distal areas, which are controlled by limited distal fan aggradation, episodic sediment input, buried previously developed calcretes and generated new space for calcrete growth by plants growing in the overlying unconsolidated materials. This allowed the renewal of calcrete formation and it led to the development of complex composite profiles which are thicker than in proximal areas, where surface stabilisation and/or dissection enabled calcrete reworking and brecciation. These processes of erosion, sedimentation, reworking and renewed calcrete formation initiated by vegetation were repeated through time. They explain the complex macro- and microstructures of these calcretes and indicate that calcrete development, even reaching mature stages, can start before the fan surface is completely abandoned, but it requires episodic sedimentation. Eventually, distal fan aggradation and continuous calcrete development throughout the entire fan surface, led to the ultimate fan surface induration, controlling subsequent landscape evolution. So, fan surface calcretes

  5. Integrated study of Mississippian Lodgepole Waulsortian Mounds, Williston Basin, USA

    SciTech Connect

    Kupecz, J.A.; Arestad, J.F.; Blott, J. E.

    1996-06-01

    Waulsortian-type carbonate buildups in the Mississippian Lodgepole Formation, Williston Basin, constitute prolific oil reservoirs. Since the initial discovery in 1993, five fields have been discovered: Dickinson Field (Lodgepole pool); Eland Field; Duck Creek Field, Versippi Field; and Hiline Field. Cumulative production (October, 1995) is 2.32 million barrels of oil and 1.34 BCF gas, with only 69,000 barrels of water. Oil gravity ranges from 41.4 to 45.3 API. Both subsurface cores from these fields as well as outcrop (Bridget Range, Big Snowy and Little Belt Mountains, Montana) are composed of facies representing deposition in mound, reworked mound, distal reworked mound, proximal flank, distal flank, and intermound settings. Porosity values within the mound and reworked mound facies are up to 15%; permeability values (in places fracture-enhanced) are up to tens of Darcies. Geometries of the mounds are variable. Mound thicknesses in the subsurface range from approximately 130-325 feet (40-100 meters); in outcrop thicknesses range from less than 30 ft (9 m) to over 250 ft (76 m). Subsurface areal dimensions range from approximately 0.5 x 1.0 mi (0.8 x 1.6 km) to 3.5 x 5.5 mi (5.6 x 8.8 km). Integration of seismic data with core and well-log models sheds light on the exploration for Lodgepole mounds. Seismic modeling of productive mounds in the Dickinson and Eland fields identifies characteristics useful for exploration, such as local thickening of the Lodgepole to Three Forks interval. These observations are confirmed in reprocessed seismic data across Eland field and on regional seismic data. Importantly, amplitude versus offset modeling identifies problems with directly detecting and identifying porosity within these features with amplitude analyses. In contrast, multicomponent seismic data has great potential for imaging these features and quantifying porous zones within them.

  6. Diagenesis and porosity evolution, Norphlet Formation in Mobile Bay, Alabama

    SciTech Connect

    Lock, B.E.; Broussard, S.W.

    1988-02-01

    Major deposits of natural gas were discovered in the Norphlet Formation beneath Mobile Bay in 1979. The reservoirs are in arkosic sandstones at depths greater than 20,000 ft, yet the productive interval has porosities up to 25%. Overlying the porous zone is a tight cap of thoroughly cemented sandstone of variable thickness, which poses problems for exploration and production. The tight zone, which together with overlying basal Smackover forms the reservoir seal, may be so thick that the underlying productive interval is substantially reduced. The upper parts of the Norphlet, in common with many other eolian sands, were reworked during a subsequent transgression. There is not a full correspondence, however, between the tight rock and the reworked facies. The origin of the impermeable zone is better understood as a function of the diagenetic history only partially related to depositional facies. It is proposed that, at an early stage of diagenesis, brines derived from the underlying Louann Salt and Werner Formation deposited anhydrite and possibly halite cements in the lower part of the Norphlet Formation. Marine working of the upper sands may have helped to disperse these brines from the upper part of the Norphlet, and the depth of reworking may even have been partially influenced by incipient cementation. The zones not already cemented by evaporites were subsequently cemented by quartz and feldspar overgrowths. At a very late stage, deep in the subsurface, the evaporite cements were flushed from the lower parts of the Norphlet, and locally abundant small feldspar crystals randomly nucleated in the pores. Gas migrated into the formation shortly afterward. Evaporites may play another important role in the petroleum geology of the deep Norphlet: the source of the gas may have been the underlying evaporites.

  7. Kids with disabilities inspire a musical instrument

    SciTech Connect

    Daily, Dan; Pfeifer, Kent

    2013-11-21

    The Midiwing is a musical instrument that unites music and computer technology for those who lack the experience, physical ability, or maturity to play music with traditional instruments. To create the instrument, Dan Daily, Director of Musicode Innovations, reworked and recoded Musical Instrument Digital Interface (MIDI) technology and introduced ergonomic design. He applied to the New Mexico Small Business Assistance (NMSBA) Program to receive help when he discovered the microcontroller he used was being phased out. Daily and Kent Pfeifer, an engineer at Sandia National Laboratories and musician himself, partnered to create a new state-of-the-art design.

  8. Kids with disabilities inspire a musical instrument

    ScienceCinema

    Daily, Dan; Pfeifer, Kent

    2016-07-12

    The Midiwing is a musical instrument that unites music and computer technology for those who lack the experience, physical ability, or maturity to play music with traditional instruments. To create the instrument, Dan Daily, Director of Musicode Innovations, reworked and recoded Musical Instrument Digital Interface (MIDI) technology and introduced ergonomic design. He applied to the New Mexico Small Business Assistance (NMSBA) Program to receive help when he discovered the microcontroller he used was being phased out. Daily and Kent Pfeifer, an engineer at Sandia National Laboratories and musician himself, partnered to create a new state-of-the-art design.

  9. Heavy minerals in surficial sediments from lower Cook Inlet, Alaska

    USGS Publications Warehouse

    Wong, F.L.

    1984-01-01

    Amphiboles, orthopyroxenes, and clinopyroxenes dominate the heavy mineral suite of surficial sediments in lower Cook Inlet, Alaska. Sources for these sediments include the igneous arc terrane of the northeast Alaska Range, reworked intrabasinal sediments, and local drainages in lower Cook Inlet. The distribution of these deposits is a reflection of both the tidal currents and the prevailing southerly net movement from the head of Cook Inlet. The heavy mineral studies concur with similar findings from gravel analyses, clay mineral investigations, and quartz microtexture observations. ?? 1984 Springer-Verlag New York Inc.

  10. Laser to single-mode-fiber coupling: A laboratory guide

    NASA Technical Reports Server (NTRS)

    Ladany, I.

    1992-01-01

    All the information necessary to achieve reasonably efficient coupling of semiconductor lasers to single mode fibers is collected from the literature, reworked when necessary, and presented in a mostly tabular form. Formulas for determining the laser waist radius and the fiber mode radius are given. Imaging relations connecting these values with the object and image distances are given for three types of lenses: ball, hemisphere, and Gradient Index (GRIN). Sources for these lenses are indicated, and a brief discussion is given about ways of reducing feedback effects.

  11. Re-Engineering Casting Production Systems - Final Report - 03/02/1998 - 03/01/2001

    SciTech Connect

    Peters, Frank; Van Voorhis, Timothy

    2001-06-25

    The goal of this three-year project was to improve the production systems in use by steel foundries in the United States. Improvements in the production systems result in less rework, less scrap, and less material handling, all of which would significantly reduce the energy demands of the process. Furthermore, these improvements would allow the companies to be more competitive, more responsive to customers' needs, deliver products with less lead time and require less capital. The ultimate result is a stronger domestic steel casting industry, which uses less energy. A major portion of this research involved the deployment of student researchers at steel foundries, to study their production systems and collect data.

  12. Magmatic and crustal differentiation history of granitic rocks from Hf-O isotopes in zircon.

    PubMed

    Kemp, A I S; Hawkesworth, C J; Foster, G L; Paterson, B A; Woodhead, J D; Hergt, J M; Gray, C M; Whitehouse, M J

    2007-02-16

    Granitic plutonism is the principal agent of crustal differentiation, but linking granite emplacement to crust formation requires knowledge of the magmatic evolution, which is notoriously difficult to reconstruct from bulk rock compositions. We unlocked the plutonic archive through hafnium (Hf) and oxygen (O) isotope analysis of zoned zircon crystals from the classic hornblende-bearing (I-type) granites of eastern Australia. This granite type forms by the reworking of sedimentary materials by mantle-like magmas instead of by remelting ancient metamorphosed igneous rocks as widely believed. I-type magmatism thus drives the coupled growth and differentiation of continental crust.

  13. Thermal tests of MC3811 rigid/flex printed wiring boards

    SciTech Connect

    Gentry, F.L.

    1990-10-01

    Rigid/flex multilayer printed wiring boards are more sensitive to thermal environmental changes than conventional printed wiring boards. This is manifested because of a composition of dissimilar materials used within the construction of this type of product. During fabrication and assembly, stresses can develop within the plated-through holes from differences in thermal properties of the rigid and flexible materials, primarily thermal coefficient of expansion. Thermal shock and thermal stress tests and rework simulation as defined in MIL-P-50884 have been performed in this study as indicators of processing quality to detect faults and to verify improvements in board reliability. 3 refs., 17 figs., 3 tabs.

  14. Removable foam encapsulants

    SciTech Connect

    Wischmann, K.B.

    1982-01-01

    This paper describes the use of two different expandable bead foams as solvent removable encapsulants; specifically they are polystyrene (STYROPOR BF-414, BASF Wyandotte) and a styrenemaleic anhydride copolymer (DYTHERM X214, ARCO/Polymers). These expandable bead foams are commercially available and normally used in insulating applications. However, they have been adapted to the unusual task of encapsulating sophisticated and expensive electronic hardware which requires a rework capability. The respective foams processing, resultant properties and removal methods are discussed in detail in this paper.

  15. Tertiary foraminiferal rock samples from the western Solomon Sea

    NASA Astrophysics Data System (ADS)

    Haig, David W.

    1986-12-01

    Rock fragments dredged from four R/VNatsushima stations contain Tertiary foraminifera. The oldest sample is an upper bathyal biomicrite of Early Eocene age (52 to 53.5 Ma) from the the Trobriand Platform. Upper Oligocene-Lower Miocene neritic limestones were located off the Trobriand Platform and on the inner wall of the New Britain Trench. Miocene bathyal sediments come from the Trobriand Platform; similar Pliocene rocks were recovered here as well as from the inner wall of the New Britain Trench and the central part of the Solomon Sea Basin. No reworked pre-Tertiary foraminifera are present in any sample.

  16. Fixture For Drilling And Tapping A Curved Workpiece

    NASA Technical Reports Server (NTRS)

    Espinosa, P. S.; Lockyer, R. T.

    1992-01-01

    Simple fixture guides drilling and tapping of holes in prescribed locations and orientations on workpiece having curved surface. Tool conceived for use in reworking complexly curved helicopter blades made of composite materials. Fixture is block of rigid foam with epoxy filler, custom-fitted to surface contour, containing bushings and sleeves at drilling and tapping sites. Bushings changed, so taps and drills of various sizes accommodated. In use, fixture secured to surface by hold-down bolts extending through sleeves and into threads in substrate.

  17. Lunar soil evolution processes and Apollo 16 core 60013/60014.

    PubMed

    Basu, A; McKay, D S

    1995-03-01

    Soils of the 62-cm deep Apollo 16 double drive tube 60013/14 are mature at the top and submature at the bottom. Modal analyses of 5529 grains from the 90-150 micrometers and the 500-1000 micrometers fractions from 12 levels of the core show that, in general, agglutinate abundance increases somewhat monotonically to the top and mimics the Is/FeO profile. There is a general decrease in the modal abundance of monomineralic fragments towards the top, suggesting that agglutinates were formed in part at the expense of monomineralic grains, especially feldspars, which are by far the most abundant mineral in these soils. In detail, the top 27 cm of the core differs from the bottom 21 cm, and the middle 14 cm is intermediate in its properties. In the upper segment, variations in the abundances of feldspars correspond with those of feldspathic fragmental breccias and cataclastic anorthosites; in the bottom segment, a similar but weak correspondence between feldspars and crystalline matrix breccias is observed. Mixing of the comminuted products of these three rock types likely produced the bulk of the core material. Many single feldspars in all size fractions are remarkably fresh, show no damage from shock, and are similar in appearance to the large feldspars in anorthosites and feldspathic fragmental breccias, which we consider to be the primary sources of single feldspars in this core. Major (Na, Al, Si, K, Ca) and minor (Fe, Ba) element analyses of 198 single feldspar grains indicate the presence of only one population of feldspars, which is consistent with our interpretation of feldspar provenance. Classification of 890 monomineralic feldspar, olivine, pyroxene, and glass spherules on the basis of the presence or absence of thin brownish coating--related to reworking at the surface--shows that coated grains are much more abundant in the top segment than in the bottom segment. A comparison with the mixing and maturation model (McKay et al., 1977) of soils in the core 60009

  18. Voice entry of hybrid microcircuit inspection data

    SciTech Connect

    Hacker, M.W.

    1987-07-01

    Because every major manufacturer is trying to keep a competitive edge, millions of dollars are being spent on factory automation. However, automation alone does not provide the total answer. If processes are not characterized and then controlled as an integral part of factory automation, a less than optimum process with low yields resulting in either high rework costs or larger scrap piles will occur. Many good articles have been written on how to setup control charts to monitor processes, however, the key to a control chart working properly is to have accurate and timely data. Voice data entry provides the means of getting accurate and timely data.

  19. The size and shape of Dante's Purgatorio

    NASA Astrophysics Data System (ADS)

    Magnaghi-Delfino, Paola; Norando, Tullia

    2015-07-01

    Where is Mount Purgatory? How high is it? How large is the island upon which it was situated? In the previous century Rodolfo Benini and Ideale Capasso developed a series of hypothesis and calculations to find answers to these questions. Each used data derived from mathematics, astronomy, history of science and cartography, but they completely disagreed on the location and on the overall size and shape of the island. In this paper we review the main points of these two scholars, then we rework the calculations and estimates, according with a new astronomical hypothesis presented by Giulio Magli and Claudio Facciolo.

  20. Pyroclastic Activity at Home Plate in Gusev Crater, Mars

    NASA Technical Reports Server (NTRS)

    Squyres, S. W.; Aharonson, O.; Clark, B. S.; Cohen, B.; Crumpler, L.; deSouza, P. A.; Farrand, W. H.; Gellert, R.; Grant, J.; Grotzinger, J. P.; Haldemann, A. F. C.; Johnson, J. R.; Klingelhoefer, G.; Lewis, K. W.; Li, R.; McCoy, T.; McEwen, A. S.; McSween, H. Y.; Ming, D. W.; Moore, J. M.; Morris, R. V.; Parker. T. J.; Rice, J. W., Jr.; Ruff, S.; Schmidt, M.

    2007-01-01

    Home Plate is a layered plateau in Gusev crater on Mars. It is composed of clastic rocks of moderately altered alkali basalt composition, enriched in some highly volatile elements. A coarse-grained lower unit is overlain by a finer-grained upper unit. Textural observations indicate that the lower strata were emplaced in an explosive event, and geochemical considerations favor an explosive volcanic origin over an impact origin. The lower unit likely represents accumulation of pyroclastic materials, while the upper unit may represent eolian reworking of the same pyroclastic materials.

  1. The first find of cuprous gold in the Lower Paleozoic psephites of the Northern Urals

    NASA Astrophysics Data System (ADS)

    Nikulova, N. Yu.; Filippov, V. N.; Shvetsova, I. V.

    2014-06-01

    The results of study of the composition of gold from conglobreccias in the basement of the Lower Paleozoic terrigenous sequence of the Polar Urals (Malaya Kara River) are presented. Three gold types distinct in chemical composition were identified. A significant part of the gold contains a high (up to 23 wt %) amount of copper, the distribution of which (increase from center to rim) in the grains is opposite to that in gold from the terrigenous Lower Paleozoic rocks of the northern Urals. It is suggested that cuprous gold is a result of destruction of the Late Cambrian serpentinites and subsequent hydrothermal reworking of Au-bearing terrigenous sequences.

  2. Availability of hydrogen for lunar base activities

    NASA Technical Reports Server (NTRS)

    Bustin, Roberta; Gibson, Everett K., Jr.

    1992-01-01

    Hydrogen will be needed on a lunar base to make water for consumables, to provide fuel, and to serve as a reducing agent in the extraction of oxygen from lunar minerals. This study was undertaken in order to learn more about the abundance and distribution of solar-wind-implanted hydrogen. Hydrogen was found in all samples studied, with concentrations, varying widely depending on soil maturity, grain size, and mineral composition. Seven cores returned from the Moon were studied. Although hydrogen was implanted in the upper surface layer of the regolith, it was found throughout the cores due to micrometeorite reworking of the soil.

  3. Availability of hydrogen for lunar base activities

    NASA Technical Reports Server (NTRS)

    Bustin, Roberta

    1990-01-01

    Hydrogen will be needed on a lunar base to make water for consumables, to provide fuel, and to serve as reducing agent in the extraction of oxygen from lunar minerals. The abundance and distribution of solar wind implanted hydrogen were studied. Hydrogen was found in all samples studied with concentrations varying widely depending on soil maturity, grain size, and mineral composition. Seven cores returned from the moon were studied. Although hydrogen was implanted in the upper surface layer of the regolith, it was found throughout the cores due to micrometeorite reworking of the soil.

  4. From Pythagoreans to Kepler: the dispute between the geocentric and the heliocentric systems

    NASA Astrophysics Data System (ADS)

    Theodossiou, E.; Danezis, E.; Manimanis, V. N.; Kalyva, E.-M.

    2002-06-01

    Some ancient Greek philosophers and thinkers questioned the geocentric system and proposed instead a heliocentric system. The main proponents of this view - which was seen as heretical at the time - are believed to have been the Pythagoreans Philolaos, Heraclides, Hicetas, and Ecphantos, but mainly Aristarchos of Samos, who placed the Sun in the position of the "central fire" of the Pythagoreans. The geocentric system, reworked by Claudius Ptolemaeus (Ptolemy), was the dominant one for centuries, and it was only during the sixteenth century that the Polish monk-astronomer, Copernicus, revisited the ancient Greek heliocentric views and became the new champion of the theory that we all accept today.

  5. Savings of 10--30% pollution reduction -- Air, and hazardous waste in painting facilities

    SciTech Connect

    Joseph, R.

    1999-07-01

    Hands-on painter training was conducted at over 23 aerospace painting facilities with the goal of lowering coating and solvent usage, VOC/HAP emissions and hazardous waste. Direct improvements came from improved painting techniques resulting in less overspray and fewer reworks. However, many of the problems do not reside with the painters= techniques or their lack of understanding of the painting processes. Inadequate equipment, poor maintenance and lack of understanding by supervisors and engineering managers largely contribute to unnecessary air and waste pollution from painting facilities. This paper provides numerous findings and recommendations that have surfaced as a result of the training programs.

  6. Lunar soil evolution processes and Apollo 16 core 60013/60014

    NASA Technical Reports Server (NTRS)

    Basu, A.; McKay, D. S.

    1995-01-01

    Soils of the 62-cm deep Apollo 16 double drive tube 60013/14 are mature at the top and submature at the bottom. Modal analyses of 5529 grains from the 90-150 micrometers and the 500-1000 micrometers fractions from 12 levels of the core show that, in general, agglutinate abundance increases somewhat monotonically to the top and mimics the Is/FeO profile. There is a general decrease in the modal abundance of monomineralic fragments towards the top, suggesting that agglutinates were formed in part at the expense of monomineralic grains, especially feldspars, which are by far the most abundant mineral in these soils. In detail, the top 27 cm of the core differs from the bottom 21 cm, and the middle 14 cm is intermediate in its properties. In the upper segment, variations in the abundances of feldspars correspond with those of feldspathic fragmental breccias and cataclastic anorthosites; in the bottom segment, a similar but weak correspondence between feldspars and crystalline matrix breccias is observed. Mixing of the comminuted products of these three rock types likely produced the bulk of the core material. Many single feldspars in all size fractions are remarkably fresh, show no damage from shock, and are similar in appearance to the large feldspars in anorthosites and feldspathic fragmental breccias, which we consider to be the primary sources of single feldspars in this core. Major (Na, Al, Si, K, Ca) and minor (Fe, Ba) element analyses of 198 single feldspar grains indicate the presence of only one population of feldspars, which is consistent with our interpretation of feldspar provenance. Classification of 890 monomineralic feldspar, olivine, pyroxene, and glass spherules on the basis of the presence or absence of thin brownish coating--related to reworking at the surface--shows that coated grains are much more abundant in the top segment than in the bottom segment. A comparison with the mixing and maturation model (McKay et al., 1977) of soils in the core 60009

  7. 22. Photocopied 1983, from original drawing (DP25793), Picatinny Arsenal, January ...

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

    22. Photocopied 1983, from original drawing (DP-25793), Picatinny Arsenal, January 5, 1937. BUILDING NO. 520, 'AGITATORS FOR POACHING TUB AND FINE STORAGE TUB, REWORKED SMOKELESS P'D'R BUILDING NO. 520,'. THESE VATS, OR VATS SIMILAR TO THEM, MAY RAVE BEEN INSTALLED IN OLD BUILDING NO. 517 (SEE PHOTO NJ-36-C-15). JUDGING FROM NOTES ON THIS DRAWING, MANY PARTS FOR THIS EQUIPMENT WERE TAKEN FROM OTHER 500 AREA BUILDINGS. - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  8. 'S.W.' and C.G. Jung: mediumship, psychiatry and serial exemplarity.

    PubMed

    Shamdasani, Sonu

    2015-09-01

    On the basis of unpublished materials, this essay reconstructs Jung's seances with his cousin, Helene Preiswerk, which formed the basis of his 1902 medical dissertation, The Psychology and Pathology of so-called Occult Phenomena. It separates out Jung's contemporaneous approach to the mediumistic phenomena she exhibited from his subsequent sceptical psychological reworking of the case. It traces the reception of the work and its significance for his own self-experimentation from 1913 onwards. Finally, it reconstructs the manner in which Jung continually returned to his first model and reframed it as an exemplar of his developing theories.

  9. Gap Filling Ceramic Insulating Putty for High Field Magnets

    NASA Astrophysics Data System (ADS)

    Rice, J. A.; Rice, H. M.

    2008-03-01

    Gaps between the A15 superconducting cable and its supports can sometimes occur requiring expensive rework of the support or filling with a non-optimal material. Recently, a new ceramic putty has been developed that can fill these gaps to fully support the superconducting cable. This ceramic material can withstand the extreme temperature differences between the high temperature heat treatment and the cryogenic operation. Significant performance improvements have been made that will enable the insulating putty to be used in some accelerator magnet systems. Processing methods will be discussed as well as strength and thermal data.

  10. The Origin of the Meridiani Sediments: the Key for Understanding the Formation of Sulfates and Layered Deposits on Mars

    NASA Technical Reports Server (NTRS)

    Niles, P.B.; Michalski, J.

    2009-01-01

    Following the discoveries made by the Opportunity rover at Meridiani Planum, members of the MER science team proposed that the Meridiani deposits are playa evaporites reworked by eolian processes. Alternate hypotheses have also been proposed to explain the deposits at Meridiani Planum, and these have highlighted serious problems with the provenance of the sedimentary material in the proposed playa hypothesis. These problems include: indications of cation-conservative weathering, the lack of a topographic basin, the intimate commingling of the most soluble and least soluble salts, and the overall scale of the deposit. These observations are important challenges to the playa scenario, and suggest that the sediment was derived from a different source.

  11. Culturally relevant science: An approach to math science education for Hispanics

    SciTech Connect

    Montellano, B.O. de

    1996-11-14

    This report describes later stages of a program to develop culturally relevant science and math programs for Hispanic students. Part of this effort was follow-up with 17 teachers who participated in early stages of the program. Response was not very good. Included with the report is a first draft effort for curriculum materials which could be used as is in such a teaching effort. Several of the participating teachers were invited to a writing workshop, where lesson plans were drafted, and critiqued and following rework are listed in this publication. Further work needs to be completed and is ongoing.

  12. Development of a preprototype vapor compression distillation water recovery subsystem

    NASA Technical Reports Server (NTRS)

    Johnson, K. L.

    1978-01-01

    The activities involved in the design, development, and test of a preprototype vapor compression distillation water recovery subsystem are described. This subsystem, part of a larger regenerative life support evaluation system, is designed to recover usable water from urine, urinal rinse water, and concentrated shower and laundry brine collected from three space vehicle crewmen for a period of 180 days without resupply. Details of preliminary design and testing as well as component developments are included. Trade studies, considerations leading to concept selections, problems encountered, and test data are also presented. The rework of existing hardware, subsystem development including computer programs, assembly verification, and comprehensive baseline test results are discussed.

  13. Anticipation and subjectivity: A commentary on an early text by Lacan

    NASA Astrophysics Data System (ADS)

    Blomme, David; Hoens, Dominiek

    2000-05-01

    In his 1945 paper Lacan discusses a sophism to exemplify crucial moments in the becoming of a human subject. One of these moments is the anticipation of an identity. This anticipatory decision is confirmed in a subsequent logical reasoning. In our paper we will present the sophism in its details and will focus on the essential moment of anticipation. The further (and sometimes implicit) reworking of this notion by Lacan shows that, according to psychoanalysis, anticipation is an important mechanism that involves time and the presence of the other.

  14. Magmatic and crustal differentiation history of granitic rocks from Hf-O isotopes in zircon.

    PubMed

    Kemp, A I S; Hawkesworth, C J; Foster, G L; Paterson, B A; Woodhead, J D; Hergt, J M; Gray, C M; Whitehouse, M J

    2007-02-16

    Granitic plutonism is the principal agent of crustal differentiation, but linking granite emplacement to crust formation requires knowledge of the magmatic evolution, which is notoriously difficult to reconstruct from bulk rock compositions. We unlocked the plutonic archive through hafnium (Hf) and oxygen (O) isotope analysis of zoned zircon crystals from the classic hornblende-bearing (I-type) granites of eastern Australia. This granite type forms by the reworking of sedimentary materials by mantle-like magmas instead of by remelting ancient metamorphosed igneous rocks as widely believed. I-type magmatism thus drives the coupled growth and differentiation of continental crust. PMID:17303751

  15. Maastrichtian ammonites from the Hornerstown Formation in New Jersey

    USGS Publications Warehouse

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

    1996-01-01

    The base of the Paleocene Hornerstown Formation at the Inversand pit and certain other localities in New Jersey yields a diverse phosphatised fauna of Maastrichtian age, including the ammonites Pachydsicus (Neodesmoceras) mokotibensis Collignon, 1952, Sphenodiscus lobatus (Tuomey, 1854), Baculites spp., and Eubaculites carinatus (Morton, 1834). S. lobatus is known from the older Red Bank Sand and Tinton Sand in New Jersey; the other species are known only from the basal Hornerstown. Occurrences at the Inversand pit are regarded as either reworked or remainie, although details of Cretaceous/Paleocene boundary events have been destroyed by pervasive burrowing that pipes the Hornerstown down into the underlying Navesink Formation.

  16. The determination of substrate conditions from the orientations of solitary rugose corals

    SciTech Connect

    Bolton, J.C.; Driese, S.G. )

    1990-10-01

    The substrate conditions of mudstone strata formed in ancient epicontinental settings may be determined from taphonomic assemblages of solitary rugose corals. Equal-area plots on the orientations of preserved corals can be used to infer whether subsequent hydrodynamic conditions affected any post-mortem reworking of the corals. Mechanically stable positions for curved corals can be determined. Curved corals preserved in mechanically stable positions are interpreted to have been deposited on firm or hard substrates. Curved corals preserved in mechanically unstable positions were probably embedded in soft or soupy substrates.

  17. Bioturbation: a fresh look at Darwin's last idea.

    PubMed

    Meysman, Filip J R; Middelburg, Jack J; Heip, Carlo H R

    2006-12-01

    Bioturbation refers to the biological reworking of soils and sediments, and its importance for soil processes and geomorphology was first realised by Charles Darwin, who devoted his last scientific book to the subject. Here, we review some new insights into the evolutionary and ecological role of bioturbation that would have probably amazed Darwin. In modern ecological theory, bioturbation is now recognised as an archetypal example of 'ecosystem engineering', modifying geochemical gradients, redistributing food resources, viruses, bacteria, resting stages and eggs. From an evolutionary perspective, recent investigations provide evidence that bioturbation had a key role in the evolution of metazoan life at the end of the Precambrian Era. PMID:16901581

  18. Taking a geometric look at the socio-political functioning schemes of the living. Catastrophe theory and theoretical sociology.

    PubMed

    Morier, Clément

    2013-09-01

    The aim of this communication is to consider morphological processes in sociology, mainly through the study of the stability of forms of sociality. At the same time, it aims to study the regulation of constraints, related to an increasingly conflictual environment, through political organization. We use a specific theoretical framework: the catastrophe theory developed by René Thom in topology, further developed by Claude Bruter from a physics point of view, and reworked by Jacques Viret in biology. The idea is to show the existence of archetypal processes organizing social forms. PMID:23943093

  19. Towards a Regolith Maturity Index for Howardites

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, David W.; Cartwright, J. A.; Herrin, J. S.; Johnson, K. N.

    2011-01-01

    The Dawn spacecraft has just arrived at asteroid 4 Vesta, parent of the howardite, eucrite and diogenite (HED) meteorites [1], to begin a yearlong surface study from orbit [2]. As Dawn will view a debris-covered surface, understanding the formation and mixing processes for the debris layer will strongly aid surface data interpretations. Howardites are polymict breccias mainly composed of clasts derived from basaltic (eucritic) and orthopy-roxenitic (diogenitic) parent materials [3]. Some howardites are poorly reworked (fragmental howardites) whilst others have been extensively gardened in an active regolith (regolithic howardites) [4]. The latter may represent an ancient, well-mixed regolith, whilst the former may be from more recent ejecta deposits [4]. Due to environmental differences, regolith development on Vesta differs in detail from that on the Moon [4-6]. We have been developing petrological criteria to apply to howardite thin sections to determine their relative regolithic maturity, which we are fine-tuning with comparison to noble gas data [7, 8]. Whilst we previously emphasized the abundance of reworked clasts (fragmental and impact-melt breccia clasts), this is an imperfect criterion: one howardite with abundant re-worked clasts (EET 99408) shows no evidence of solar wind Ne (SW-Ne), yet, two of our alleged fragmental howardites have clear SW-Ne signatures (LEW 85313, MET 00423) [7, 8]. We are now investigating the diversity in minor and trace element contents of low-Ca pyroxene clasts in howardites as a measure of regolith grade, and will begin analyses of such grains within reworked clasts. Our hypothesis is that regolithic howardites (and the breccia clasts they contain) will show greater diversity because they sampled more diverse diogenitic plutons than fragmental howardites, which formed from ejecta from only a few impacts [e.g. 4]. Our initial LA-ICP-MS work showed ranges in trace element diversity in low-Ca pyroxenes (estimated from the standard

  20. Reliability in the design phase

    SciTech Connect

    Siahpush, A.S.; Hills, S.W.; Pham, H. ); Majumdar, D. )

    1991-12-01

    A study was performed to determine the common methods and tools that are available to calculated or predict a system's reliability. A literature review and software survey are included. The desired product of this developmental work is a tool for the system designer to use in the early design phase so that the final design will achieve the desired system reliability without lengthy testing and rework. Three computer programs were written which provide the first attempt at fulfilling this need. The programs are described and a case study is presented for each one. This is a continuing effort which will be furthered in FY-1992. 10 refs.

  1. Reliability in the design phase

    SciTech Connect

    Siahpush, A.S.; Hills, S.W.; Pham, H.; Majumdar, D.

    1991-12-01

    A study was performed to determine the common methods and tools that are available to calculated or predict a system`s reliability. A literature review and software survey are included. The desired product of this developmental work is a tool for the system designer to use in the early design phase so that the final design will achieve the desired system reliability without lengthy testing and rework. Three computer programs were written which provide the first attempt at fulfilling this need. The programs are described and a case study is presented for each one. This is a continuing effort which will be furthered in FY-1992. 10 refs.

  2. Taking a geometric look at the socio-political functioning schemes of the living. Catastrophe theory and theoretical sociology.

    PubMed

    Morier, Clément

    2013-09-01

    The aim of this communication is to consider morphological processes in sociology, mainly through the study of the stability of forms of sociality. At the same time, it aims to study the regulation of constraints, related to an increasingly conflictual environment, through political organization. We use a specific theoretical framework: the catastrophe theory developed by René Thom in topology, further developed by Claude Bruter from a physics point of view, and reworked by Jacques Viret in biology. The idea is to show the existence of archetypal processes organizing social forms.

  3. A system architecture for a highly autonomous Mars rover

    NASA Astrophysics Data System (ADS)

    Rosenthal, Donald A.; Johnston, Mark D.

    1992-08-01

    A system to enable highly autonomous robotic exploration has been designed and prototyped. The system uses the concept of a centralized executive to control and coordinate the activities of the various component subsystems. The plan mediation, or coordination, is enabled by a highly efficient constraint-based scheduling system. This scheduler, which is the main component of the centralized executive, generates timelines that accommodate as many of the highest priority goals as possible. As plans are executed or tasks fail, and as new goals are received by the system, the executive continually reworks the schedule to reflect the current complement of plans and resource availability and utilization.

  4. Pyroclastic activity at home plate in Gusev crater, Mars

    USGS Publications Warehouse

    Squyres, S. W.; Aharonson, O.; Clark, B. C.; Cohen, B. A.; Crumpler, L.; de Souza, P.A.; Farrand, W. H.; Gellert, Ralf; Grant, J.; Grotzinger, J.P.; Haldemann, A.F.C.; Johnson, J. R.; Klingelhofer, G.; Lewis, K.W.; Li, R.; McCoy, T.; McEwen, A.S.; McSween, H.Y.; Ming, D. W.; Moore, Johnnie N.; Morris, R.V.; Parker, T.J.; Rice, J. W.; Ruff, S.; Schmidt, M.; Schroder, C.; Soderblom, L.A.; Yen, A.

    2007-01-01

    Home Plate is a layered plateau in Gusev crater on Mars. It is composed of clastic rocks of moderately altered alkali basalt composition, enriched in some highly volatile elements. A coarse-grained lower unit lies under a finer-grained upper unit. Textural observations indicate that the lower strata were emplaced in an explosive event, and geochemical considerations favor an explosive volcanic origin over an impact origin. The lower unit likely represents accumulation of pyroclastic materials, whereas the upper unit may represent eolian reworking of the same pyroclastic materials.

  5. Design, processing and testing of LSI arrays, hybrid microelectronics task

    NASA Technical Reports Server (NTRS)

    Himmel, R. P.; Stuhlbarg, S. M.; Ravetti, R. G.; Zulueta, P. J.; Rothrock, C. W.

    1979-01-01

    Mathematical cost models previously developed for hybrid microelectronic subsystems were refined and expanded. Rework terms related to substrate fabrication, nonrecurring developmental and manufacturing operations, and prototype production are included. Sample computer programs were written to demonstrate hybrid microelectric applications of these cost models. Computer programs were generated to calculate and analyze values for the total microelectronics costs. Large scale integrated (LST) chips utilizing tape chip carrier technology were studied. The feasibility of interconnecting arrays of LSU chips utilizing tape chip carrier and semiautomatic wire bonding technology was demonstrated.

  6. INGRID: a three-dimensional mesh generator for modeling nonlinear systems

    SciTech Connect

    Stillman, D.W.; Hallquist, J.O.

    1985-07-01

    INGRID generates complete input files for the codes DYNA3D, NIKE3D, FACET, and TOPAZ3D. Geometries are described primarily using index space concepts which came from the program INGEN. The ideas used in INGEN were reworked into a new method which is both simple and powerful. Interactive graphics in INGRID are patterned after TAURUS, a three-dimensional post-processor, and MAZE, a two-dimensional mesh generator. Much of the coding from MAZE is directly incorporated in INGRID.

  7. Origin of chert grains and a halite- silcrete bed in the Cambrian and Ordovician Whitehall Formation of eastern New York State.

    USGS Publications Warehouse

    Rubin, D.M.; Friedman, G.M.

    1981-01-01

    A chert bed in this Formation is strikingly similar in petrography and inferred origin to Australian and South African silcretes. It occurs along an erosion surface that formed subaerially, and it contains colloform chalcedony and abundant ferruginous minerals. This chert also contains pseudomorphs and ghosts of halite. Silica precipitated from a solution that became enriched in electrolytes as a result of dissolving halite. Sand- size chert grains in the Whitehall are petrographically like the Whitehall silcrete and are probably grains of reworked silcrete.-Authors

  8. Radionuclide disequilibria studies for investigating the integrity of potential nuclear waste disposal sites: subseabed studies.

    SciTech Connect

    Laul, J.C.; Thomas, C.W.; Petersen, M.R.; Perkins, R.W.

    1981-09-01

    This study of subseabed sediments indicates that natural radionuclides can be employed to define past long-term migration rates and thereby evaluate the integrity of potential disposal sites in ocean sediments. The study revealed the following conclusions: (1) the sedimentation rate of both the long and short cores collected in the North Pacific is 2.5 mm/1000 yr or 2.5 m/m.yr in the upper 3 meters; (2) the sedimentation rate has been rather constant over the last one million years; and (3) slow diffusive processes dominate within the sediment. Reworking of the sediment by physical processes or organisms is not observed.

  9. Paleocene to Middle Miocene planktic foraminifera of the southwestern Salisbury Embayment, Virginia and Maryland: biostratigraphy, allostratigraphy, and sequence stratigraphy

    USGS Publications Warehouse

    Poag, C.W.; Commeau, J.A.

    1995-01-01

    The Paleocene to Middle Miocene sedimentary fill of the southwestern Salisbury Embayment contains a fragmental depositional record, interrupted by numerous local diastems and regional unconformities. Using planktic foraminiferal biostratigraphy, 15 unconformity-bounded depositional units have been identified, assigned to six formations and seven alloformations previously recognized in the embayment. The units correlate with second- and third-order sequences of the Exxon sequence stratigraphy model, and include transgressive and highstand systems tracts. Alloformation, formation, and sequence boundaries are marked by abrupt, scoured, burrowed, erosional surfaces, which display lag deposits, biostratigraphic gaps, and intense reworking of microfossils above and below the boundaries. -from Authors

  10. Rare accessory uraninite in a Sierran granite

    NASA Technical Reports Server (NTRS)

    Snetsinger, K. G.; Polkowski, G.

    1977-01-01

    One grain of uraninite was found in a single thin-section of Sierran granite. Electron and ion microprobe analysis were used to determine the composition. Since the U-Pb age calculated for the uraninite does not differ greatly from the K-Ar age of the unit in which it occurs, it is suggested that the mineral is primary and not reworked from a preexisting rock. No uraninite has been detected in heavy mineral concentrates from other rocks of the local area.

  11. The heterogeneity of clinical ethics: the state of the field as reflected in the Encyclopedia of Bioethics.

    PubMed

    Koczwara, B; Madigan, T J

    1997-02-01

    The 1995 Encyclopedia of Bioethics is an almost complete reworking of the original 1978 edition, due to the expanding nature of the field. The following article focuses on how the second edition of the Encyclopedia deals with the topic of "clinical ethics" and three related topics: "nursing ethics", "trust", and "conflict of interest". We assess their relevance to the current developments in these fields and the Encyclopedia's usefulness as a resource to ethics consultants, researchers and clinicians. We emphasize the heterogeneity of clinical ethics as a still new and evolving field.

  12. The paleogeographic significance of Aquilapollenites occurrence in Pakistan

    NASA Astrophysics Data System (ADS)

    Khan, Asrar M.; Srivastava, Satish K.

    2006-12-01

    The occurrence of the genus Aquilapollenites in Upper Cretaceous and Neogene sediments of northwestern Pakistan is reported here. Aquilapollenites amplus, Aquilapollenites reductus, and Aquilapollenites sp. occur in the Maastrichtian palynomorph assemblage from an outcrop sample of the Mir Ali section, northern Waziristan. Aquilapollenites medeis in the Neogene Murgha Faqir Zai Formation of the Pishin Basin, Balochistan, is considered a reworked Cretaceous specimen. The Upper Cretaceous sediments of the Asian plate on the Tethys margin are considered to be the source of Aquilapollenites spp. in these samples.

  13. Period04: Statistical analysis of large astronomical time series

    NASA Astrophysics Data System (ADS)

    Lenz, Patrick; Breger, Michel

    2014-07-01

    Period04 statistically analyzes large astronomical time series containing gaps. It calculates formal uncertainties, can extract the individual frequencies from the multiperiodic content of time series, and provides a flexible interface to perform multiple-frequency fits with a combination of least-squares fitting and the discrete Fourier transform algorithm. Period04, written in Java/C++, supports the SAMP communication protocol to provide interoperability with other applications of the Virtual Observatory. It is a reworked and extended version of Period98 (Sperl 1998) and PERIOD/PERDET (Breger 1990).

  14. Bioturbation: a fresh look at Darwin's last idea.

    PubMed

    Meysman, Filip J R; Middelburg, Jack J; Heip, Carlo H R

    2006-12-01

    Bioturbation refers to the biological reworking of soils and sediments, and its importance for soil processes and geomorphology was first realised by Charles Darwin, who devoted his last scientific book to the subject. Here, we review some new insights into the evolutionary and ecological role of bioturbation that would have probably amazed Darwin. In modern ecological theory, bioturbation is now recognised as an archetypal example of 'ecosystem engineering', modifying geochemical gradients, redistributing food resources, viruses, bacteria, resting stages and eggs. From an evolutionary perspective, recent investigations provide evidence that bioturbation had a key role in the evolution of metazoan life at the end of the Precambrian Era.

  15. Lunar soil evolution processes and Apollo 16 core 60013/60014.

    PubMed

    Basu, A; McKay, D S

    1995-03-01

    Soils of the 62-cm deep Apollo 16 double drive tube 60013/14 are mature at the top and submature at the bottom. Modal analyses of 5529 grains from the 90-150 micrometers and the 500-1000 micrometers fractions from 12 levels of the core show that, in general, agglutinate abundance increases somewhat monotonically to the top and mimics the Is/FeO profile. There is a general decrease in the modal abundance of monomineralic fragments towards the top, suggesting that agglutinates were formed in part at the expense of monomineralic grains, especially feldspars, which are by far the most abundant mineral in these soils. In detail, the top 27 cm of the core differs from the bottom 21 cm, and the middle 14 cm is intermediate in its properties. In the upper segment, variations in the abundances of feldspars correspond with those of feldspathic fragmental breccias and cataclastic anorthosites; in the bottom segment, a similar but weak correspondence between feldspars and crystalline matrix breccias is observed. Mixing of the comminuted products of these three rock types likely produced the bulk of the core material. Many single feldspars in all size fractions are remarkably fresh, show no damage from shock, and are similar in appearance to the large feldspars in anorthosites and feldspathic fragmental breccias, which we consider to be the primary sources of single feldspars in this core. Major (Na, Al, Si, K, Ca) and minor (Fe, Ba) element analyses of 198 single feldspar grains indicate the presence of only one population of feldspars, which is consistent with our interpretation of feldspar provenance. Classification of 890 monomineralic feldspar, olivine, pyroxene, and glass spherules on the basis of the presence or absence of thin brownish coating--related to reworking at the surface--shows that coated grains are much more abundant in the top segment than in the bottom segment. A comparison with the mixing and maturation model (McKay et al., 1977) of soils in the core 60009

  16. Regolith depositional history at Shorty Crater

    NASA Technical Reports Server (NTRS)

    Crozaz, G.

    1978-01-01

    Nuclear particle track measurements in the 68 cm double drive tube 74002-74001 indicate that the whole core was deposited in one event some 10 m.y. ago. Significant reworking of the soil only occurred down to a few cm from the lunar surface since this event. Complementary investigations in this core by other groups are discussed. Most of the evidence available leads to a two stage model in which the orange and black soils collected at Shorty Crater were first irradiated for approximately 25 m.y. at some depth and then were deposited only a few m.y. ago as an overturned ejecta blanket.

  17. Contemporary sedimentation in the forefield of Hornbreen Hornsund

    NASA Astrophysics Data System (ADS)

    Staszek, Monika W.; Moskalik, Mateusz J.

    2015-10-01

    The paper presents a model of contemporary sedimentation in the forefield of Hornbreen, tidewater glacier in Brepollen. The model is based on the results of grain-size analyses of bottom sediments and the information about dominant sedimentary processes in glaciated fjords. It is concluded that apart from the tidewater glacier which is the main source of sediment in this area, the material is transported also from the shores. Subsequently, the material is redeposited by iceberg-caused reworking, slides and gravity flows. Strong decreasing trend of particles' diameters with increasing distance from the ice cliff is observed.

  18. Scatological origin of microvertebrate fossil accumulations.

    PubMed

    Mellett, J S

    1974-07-26

    Small-mammal bone found in Recent carnivore droppings (scat) is identical in appearance with that in many Mesozoic and Tertiary microvertebrate fossil collections. Such fossil specimens passed into or through the digestive tracts of carnivores before being left as scat that was later reworked into sedimentary rocks. The term "coprocoenosis" is proposed for such an assemblage. Caution is urged in drawing conclusions about the composition of paleocommunities because carnivores can catch prey representing several different communities and leave a mixed assemblage in a particular depositional environment.

  19. Lateral genomics.

    PubMed

    Doolittle, W F

    1999-12-01

    More than 20 complete prokaryotic genome sequences are now publicly available, each by itself an unparalleled resource for understanding organismal biology. Collectively, these data are even more powerful: they could force a dramatic reworking of the framework in which we understand biological evolution. It is possible that a single universal phylogenetic tree is not the best way to depict relationships between all living and extinct species. Instead a web- or net-like pattern, reflecting the importance of horizontal or lateral gene transfer between lineages of organisms, might provide a more appropriate visual metaphor. Here, I ask whether this way of thinking is really justified, and explore its implications.

  20. Development and application of a proficiency evaluation methodology for the nuclear power industry

    SciTech Connect

    Brittain, K.R.

    1997-12-01

    Recent changes in the electric power industry have increased the need to improve performance, shorten plant outages, reduce unnecessary rework, and improve maintenance. Over the last 10 yr, organizations such as the Institute of Nuclear Power Operations (INPO) and the U.S. Nuclear Regulatory Commission have reviewed many factors that can lead to operations and reliability improvements. One of the areas that has received a significant amount of attention has been training. Almost all nuclear utilities have training facilities accredited by INPO. A number of utilities have centralized their training activities for all facets of their organization.

  1. Shallow gas off the Rhône prodelta, Gulf of Lions

    USGS Publications Warehouse

    Garcia-Garcia, Ana; Orange, Daniel L.; Lorenson, T.; Radakovitch, Olivier; Tesi, Tommaso; Miserocchi, Stefano; Berne, Serge; Friend, P.L.; Nittrouer, Chuck; Normand, Alain

    2006-01-01

    In areas unaffected by the high flux of organic matter and rapid/thick flood deposition, or in between flood events, the conditions for methanogenesis and gas accumulation have not been met; in these areas, the physical and biological reworking of the surficial sediment may effectively oxidize and mineralize organic matter and limit bacterial methanogenesis in the sub-surface. We propose that in the Rhône prodelta flood deposits deliver significant amounts of terrigenous organic matter that can be rapidly buried, effectively removing this organic matter from aerobic oxidation and biological uptake and leading to the potential for methanogenesis with burial.

  2. Wisconsinan and Sangamonian climate interpreted from fossil ostracodes and vegetation in south-central Illinois

    SciTech Connect

    Curry, B.B. ); Forester, R.M. ); Zhu, Hong; Baker, R.G. . Dept. of Geology)

    1992-01-01

    The interpretation of paleoclimate during the late Illinoian, Sangamonian, and Wisconsinan Ages in the region of present south-central Illinois has been based on plant macrofossil, pollen, and vertebrate records. The ostracode records identify periods of flow across the basins and perhaps characteristics of groundwater discharge or recharge. Basins with the largest lake-to-catchment-area ratio were most sensitive to changes in effective moisture and hydrochemistry. The Sangamonian included three intervals during which the winters were warmer than those of historical record. These intervals are represented by sediment containing relatively abundant arboreal pollen, notably bald cypress and sweet gum, and the ostracode Heterocypris punctata, which lives in subtropical to tropical lakes and estuaries. H. punctata occurs with other ostracodes that require low salinity; their association indicates that precipitation typically exceeded evaporation and that the basin was affected by throughflow. The Sangamonian ended with two warm, wet episodes that sandwich an interval implying prairie lake conditions. Warmth-loving species are abundantly represented in upper Sangamonian sediments. Such warm, wet episodes are not known to have occurred in the Midcontinent during the Holocene. The top of the Sangamonian in all except the Pittsburgh Basin is capped by a layer of reworked sediment containing fluvial ostracodes and exotic mixtures of pollen, including both spruce and sweet gum but dominated by chenopods. The reworked layer is overlain by Wisconsinan sediment containing abundant pollen of boreal taxa and ostracodes that indicate basin throughflow.

  3. Dry and clean age hardening of aluminum alloys by high-pressure gas quenching

    NASA Astrophysics Data System (ADS)

    Irretier, A.; Kessler, O.; Hoffmann, F.; Mayr, P.

    2004-10-01

    When precipitation-hardenable aluminum parts are water quenched, distortion occurs due to thermal stresses. Thereby, a costly reworking is necessary, and for this reason polymer quenchants are often used to reduce distortion, with the disadvantage that the quenched parts have to be cleaned after quenching. In opposition to liquid quenchants, gas quenching may decrease distortion due to the better temperature uniformity during quenching. Furthermore, cleaning of the quenched parts can be avoided because it is a dry process. For this purpose, a heat-treating process was evaluated that included a high-pressure gasquenching step. Gas quenching was applied to different aluminum alloys (i.e., 2024, 6013, 7075, and A357.0), and tensile tests have been carried out to determine the mechanical properties after solution annealing, gas quenching, and aging. Besides high-pressure gas quenching, alloy 2024 was quenched at ambient pressure in a gas nozzle field. The high velocity at the gas outlet leads to an accelerated cooling of the aluminum alloy in this case. Aluminum castings and forgings can be classified as an interesting field of application of these quenching methods due to their near-net shape before the heat treatment. Cost savings would be possible due to the reduced distortion, and therefore, less reworking after the precipitation hardening.

  4. On intra-supply chain system with an improved distribution plan, multiple sales locations and quality assurance.

    PubMed

    Chiu, Singa Wang; Huang, Chao-Chih; Chiang, Kuo-Wei; Wu, Mei-Fang

    2015-01-01

    Transnational companies, operating in extremely competitive global markets, always seek to lower different operating costs, such as inventory holding costs in their intra- supply chain system. This paper incorporates a cost reducing product distribution policy into an intra-supply chain system with multiple sales locations and quality assurance studied by [Chiu et al., Expert Syst Appl, 40:2669-2676, (2013)]. Under the proposed cost reducing distribution policy, an added initial delivery of end items is distributed to multiple sales locations to meet their demand during the production unit's uptime and rework time. After rework when the remaining production lot goes through quality assurance, n fixed quantity installments of finished items are then transported to sales locations at a fixed time interval. Mathematical modeling and optimization techniques are used to derive closed-form optimal operating policies for the proposed system. Furthermore, the study demonstrates significant savings in stock holding costs for both the production unit and sales locations. Alternative of outsourcing product delivery task to an external distributor is analyzed to assist managerial decision making in potential outsourcing issues in order to facilitate further reduction in operating costs. PMID:26576330

  5. ADVANCED TECHNOLOGIES FOR STRIPPER GAS WELL ENHANCEMENT

    SciTech Connect

    Ronald J. MacDonald

    2005-04-27

    As part of Task 1 in Advanced Technologies for Stripper Gas Well Enhancement, Schlumberger Data & Consulting Services (DCS) joined with two Appalachian Basin producers, Great Lakes Energy Partners, LLC, and Belden & Blake Corporation to develop methodologies for identification and enhancement of stripper wells with economic upside potential. These industry partners previously provided us with data for more than 700 wells in northwestern Pennsylvania. Phase 1 goals of this project were to develop and validate methodologies that can quickly and cost-effectively identify underperforming wells with remediation potential. We enhanced and streamlined our software and are using it with Microsoft's{trademark} Access and Excel programs. During the last quarter of 2002, Great Lakes provided us with additional data for approximately 2,200 wells located in their Cooperstown field situated in northwestern Pennsylvania. We identified approximately 220 potential remediation candidates and Great Lakes personnel reviewed this list for viability and selected more than twenty five wells to be reworked. Approximately fifteen wells have been successfully reworked as of year-end 2004. This field provided a rigorous test of our software and analytical methods. We processed all the information provided to us including the Cooperstown data. Great Lakes also provided supplemental data listing the original operator of the wells.

  6. Factors controlling navigation-channel Shoaling in Laguna Madre, Texas

    USGS Publications Warehouse

    Morton, R.A.; Nava, R.C.; Arhelger, M.

    2001-01-01

    Shoaling in the Gulf Intracoastal Waterway of Laguna Madre, Tex., is caused primarily by recycling of dredged sediments. Sediment recycling, which is controlled by water depth and location with respect to the predominant wind-driven currents, is minimal where dredged material is placed on tidal flats that are either flooded infrequently or where the water is extremely shallow. In contrast, nearly all of the dredged material placed in open water >1.5 m deep is reworked and either transported back into the channel or dispersed into the surrounding lagoon. A sediment flux analysis incorporating geotechnical properties demonstrated that erosion and not postemplacement compaction caused most sediment losses from the placement areas. Comparing sediment properties in the placement areas and natural lagoon indicated that the remaining dredged material is mostly a residual of initial channel construction. Experimental containment designs (shallow subaqueous mound, submerged levee, and emergent levee) constructed in high-maintenance areas to reduce reworking did not retain large volumes of dredged material. The emergent levee provided the greatest retention potential approximately 2 years after construction.

  7. Benthic ecosystem functioning in the severely contaminated Mar Piccolo of Taranto (Ionian Sea, Italy): focus on heterotrophic pathways.

    PubMed

    Franzo, A; Auriemma, R; Nasi, F; Vojvoda, J; Pallavicini, A; Cibic, T; Del Negro, P

    2016-07-01

    The benthic ecosystem functioning is a rarely applied holistic approach that integrates the main chemical and biological features of the benthic domain with the key processes responsible for the flux of energy and C through the system. For the first time, such conceptual model, with an emphasis on the heterotrophic pathways, has been applied to the sediments at four stations within one of the most polluted coastal areas in Italy: the Mar Piccolo of Taranto. The functioning of the benthic ecosystem was different according to the investigated site. Nearby the military arsenal, i.e., the main source of organic contaminants and heavy metals, the system seemed inhibited at all the investigated structural and functional levels. Slow microbial processes of C reworking together with very limited densities of benthic fauna suggested a modest transfer of C both into a solid microbial loop and to the higher trophic levels. On the other hand, the ingression of marine water through the "Navigabile" channel seemed to stimulate the organic matter degradation and, consequently, the proliferation of meiofauna and macrofauna. In the innermost part of the basin, the system functioning, to some extent, is less impacted by contaminants and more influenced by mussel farms. The organic matter produced by these bivalves fueled faster C reworking by benthic prokaryotes and enhanced the proliferation of filter feeders. PMID:26370810

  8. Paleoseismic inferences from a high-resolution marine sedimentary record in northern Chile (23°S)

    NASA Astrophysics Data System (ADS)

    Vargas, Gabriel; Ortlieb, Luc; Chapron, Emmanuel; Valdes, Jorge; Marquardt, Carlos

    2005-04-01

    The active margin of northern Chile is characterized by strong seismic events which induce gravity instability for sedimentary sequences located along the outer forearc of the Andean range. Even though the narrow continental platform of this area limits the accumulation of marine sediments, a detailed paleoceanographic reconstruction, using high-resolution sedimentological and geochronological techniques, of a Holocene sedimentary sequence in Mejillones bay (23°S) provides important tools to infer the occurrence of past great subduction earthquakes and/or associated tsunamis. From the analyses of short cores retrieved in this shallow marine basin, we infer the occurrence of two strong seismic events during historical times. The first one, dated between the years 1409 and 1449 AD, produced an angular unconformity and associated lenticular coarse-grained deposits generated after local reworking of shallower material. The second one, dated between the years 1754 and 1789 AD, caused slumping, erosive processes and local reworking of material. The analysis of seismic profile data acquired in this bay allowed the recognition of a major slump deposit within the upper sedimentary sequence, tentatively dated as of Middle Holocene age. This event might record the greatest earthquake (and tsunami) affecting the basin within the last few thousand years. We interpret that destabilization of sediments occurs most probably in response to local reactivation of faults within the Mejillones peninsula during strong earthquakes, especially the Mejillones fault.

  9. Controls on spatial and temporal distribution of Precambrian eolianites

    NASA Astrophysics Data System (ADS)

    Eriksson, Kenneth A.; Simpson, Edward L.

    1998-09-01

    Inversely graded stratification, generated by the migration of wind ripples, and adhesion structures permit unequivocal identification of Precambrian eolianites. These criteria, in combination with scale of cross-beds, angle of inclination of foresets, geometry of depositional units, and associated non-eolian facies, are used to discriminate between Precambrian dune/draa, dune-plinth, sand-sheet, and interdune deposits that formed in inland and coastal settings. Based on an analysis of published literature, fundamental conclusions can be drawn on the spatial and temporal distribution of Precambrian eolianites. The oldest reported eolianites are from the ca. 2.1 Ga Deweras Group in Zimbabwe and Hurwitz Group in Canada and numerous examples of eolianites are reported from the 1.8 Ga and younger rock record. Lack of Archean and early Paleoproterozoic eolianites and their widespread development after 1.8 Ga are examined with respect to: absence of vegetation, crustal growth and tectonic setting, relative sea-level fluctuations, unfavorable atmospheric and/or climatic change, and non-recognition. The lack of pre-2.2 Ga eolianites may be related to reworking by braided rivers combing across non-vegetated floodplains, reworking of coastal eolianites during transgression or their non-recognition in the Early Precambrian record. The temporal concentration of eolianites at 1.8 Ga may best be related to the early stages of breakup and the assembly phases of supercontinents.

  10. Landscape response to deglaciation in a high relief, monsoon-influenced alpine environment, Langtang Himal, Nepal

    USGS Publications Warehouse

    Barnard, P.L.; Owen, L.A.; Finkel, R.C.; Asahi, K.

    2006-01-01

    Significant glacial fluctuations and rapid paraglacial reworking of glacigenic sediments characterize the Middle and Late Holocene of the Langtang Khola Valley, Central Nepal Himalaya. Geomorphic mapping and beryllium-10 cosmogenic radionuclide (CRN) dating of moraines and paraglacial fans were undertaken to test the existing paraglacial fan, terrace and moraine chronologies. The new dating compares favorably with prior studies that utilized radiocarbon, adding additional support to the assumption that fan and terrace formation are strongly linked to deglaciation. Fan and terrace denudation rates are so rapid in this region, averaging ∼33 mm/yr, that no depositional landforms older than 5 ka are preserved within 250 m of the valley floor. In this region, high rates of denudation during the Late Quaternary are driven by a combination of rapid tectonic uplift, numerous glacial fluctuations and intense weathering driven by an active monsoon climate. Extensive reworking of glacigenic sediments in Langtang during the latter half of the Holocene is consistent with studies completed in other areas of the Himalaya that are strongly influenced by the monsoon.

  11. Two phase deglaciation incorporating a late-stage readvance in the Brunswick, Maine area

    SciTech Connect

    Borelli, C.; Smity, P. . Dept. of Geoscience)

    1993-03-01

    Reinterpretation of late Wisconsinan glacial deposits indicate that retreat of the Laurentide ice margin occurred west of the marine limit in the Brunswick area. Marine transgression deposited the overlying Presumpscot Formation which locally contains organic rich, silty sand. A regionally extensive readvance deformed and truncated the uppermost glaciomarine sediments during the oceanic highstand. Striations and other ice flow indicators which are found underlying the Presumpscot Formation consistently trend NW-SE, while those found on exposed outcrops above the Presumpscot Formation dominantly trend NE-SW. These otherwise anomalous directional flow indicators support a late stage readvance of the ice sheet. Areally extensive, stratified, and locally imbricated outwash caps the glaciomarine sediments. Mineral composition of the basal outwash differs from the upper outwash sequences, supporting the readvance model by indicating different source areas. Multi-phase emergence characterized by terraced landforms caused a reworking and redeposition of sediment in a fluvial, tidally influenced environment. Localized eolian deposits record a late phase reworking of sediment.

  12. Benthic ecosystem functioning in the severely contaminated Mar Piccolo of Taranto (Ionian Sea, Italy): focus on heterotrophic pathways.

    PubMed

    Franzo, A; Auriemma, R; Nasi, F; Vojvoda, J; Pallavicini, A; Cibic, T; Del Negro, P

    2016-07-01

    The benthic ecosystem functioning is a rarely applied holistic approach that integrates the main chemical and biological features of the benthic domain with the key processes responsible for the flux of energy and C through the system. For the first time, such conceptual model, with an emphasis on the heterotrophic pathways, has been applied to the sediments at four stations within one of the most polluted coastal areas in Italy: the Mar Piccolo of Taranto. The functioning of the benthic ecosystem was different according to the investigated site. Nearby the military arsenal, i.e., the main source of organic contaminants and heavy metals, the system seemed inhibited at all the investigated structural and functional levels. Slow microbial processes of C reworking together with very limited densities of benthic fauna suggested a modest transfer of C both into a solid microbial loop and to the higher trophic levels. On the other hand, the ingression of marine water through the "Navigabile" channel seemed to stimulate the organic matter degradation and, consequently, the proliferation of meiofauna and macrofauna. In the innermost part of the basin, the system functioning, to some extent, is less impacted by contaminants and more influenced by mussel farms. The organic matter produced by these bivalves fueled faster C reworking by benthic prokaryotes and enhanced the proliferation of filter feeders.

  13. Carbon in dark inclusions of the Allende meteorite

    NASA Technical Reports Server (NTRS)

    Heymann, D.; Van Der Stap, C. C. A. H.; Vis, R. N.; Verheul, H.

    1987-01-01

    Carbon contents of three dark inclusions (DI's) of the Allende meteorite, measured chemically, range from 0.56 to 1.17 wt pct. When one includes the data reported by Bunch, Chang, and Ott (1980), the lower limit is 0.44 pct. The C-concentration map of a 1.6 x 1.6 sq mm area straddling the boundary of a DI and matrix, or of a DI and its dark halo, obtained with a C-12(d,p)C-13 nuclear microprobe, shows that the C-content of the core of the DI is very uniform, and that the C-content of the rim is 2.9 + or - 0.3 times larger. Variability of the C-content of matrix and matrix-like areas of Allende appears to be the rule. DIs cannot be a reworked bulk Allende, or a precursor for bulk Allende without the addition or, respectively, removal of significant amounts of carbon. However, some type 1 DIs might be reworked Allende matrix or precursor matter for that matrix.

  14. A bioturbation classification of European marine infaunal invertebrates

    PubMed Central

    Queirós, Ana M; Birchenough, Silvana N R; Bremner, Julie; Godbold, Jasmin A; Parker, Ruth E; Romero-Ramirez, Alicia; Reiss, Henning; Solan, Martin; Somerfield, Paul J; Van Colen, Carl; Van Hoey, Gert; Widdicombe, Stephen

    2013-01-01

    Bioturbation, the biogenic modification of sediments through particle reworking and burrow ventilation, is a key mediator of many important geochemical processes in marine systems. In situ quantification of bioturbation can be achieved in a myriad of ways, requiring expert knowledge, technology, and resources not always available, and not feasible in some settings. Where dedicated research programmes do not exist, a practical alternative is the adoption of a trait-based approach to estimate community bioturbation potential (BPc). This index can be calculated from inventories of species, abundance and biomass data (routinely available for many systems), and a functional classification of organism traits associated with sediment mixing (less available). Presently, however, there is no agreed standard categorization for the reworking mode and mobility of benthic species. Based on information from the literature and expert opinion, we provide a functional classification for 1033 benthic invertebrate species from the northwest European continental shelf, as a tool to enable the standardized calculation of BPc in the region. Future uses of this classification table will increase the comparability and utility of large-scale assessments of ecosystem processes and functioning influenced by bioturbation (e.g., to support legislation). The key strengths, assumptions, and limitations of BPc as a metric are critically reviewed, offering guidelines for its calculation and application. PMID:24198953

  15. Dynamic depositional and early diagenetic processes in a deep-water shelf setting, upper cretaceous Austin Chalk, North Texas

    SciTech Connect

    Hovorka, S.D.; Nance, H.S.

    1994-12-31

    The Austin Chalk of north Texas was deposited on a deep-water shelf north of the Sea Marcos Platform during a worldwide Coniacian and Santonian sea-level highstand. Transgressive (lowermost lower Austin Chalk), highstand (uppermost lower Austin Chalk), and regressive (middle and upper Austin Chalk) phases of cyclic chalk and marl sedimentation are recognized in excavations and tunnels created in Ellis County for the Superconducting Super Collider provide new evidence of sediment transport during Austin Chalk deposition. During transgression, bottom currents syndepositionally reworked nannoplankton oozes, incising channels as much as 120 ft across and 8 ft deep. Weakly burrowed channel fills having preservation of fine lamination document rapid infilling. Channel fills are composed of pyritized and carbonized wood and Inoceramus lag deposits, pellets, echinoderm fragments, and globigerinid grainstones, and coccolith ooze. During maximum highstand, bottom reworking was suppressed. Detrital content of highstand marls is low (>20 percent); organic content is high (1.4 to 3.5 percent). Coccolith preservation is excellent because of minimal diagenetic alteration. Regression is marked by resumed channel cutting and storm-bed winnowing in the middle and upper Austin Chalk. Suppressed resistivity log response and recessive weathering characteristics of the middle Austin Chalk are not primarily related to depositional environment but rather to increased input of volcanic ash during the accumulation of this interval. Early stabilization of ash produced clay-coated microfabrics in sediments that are otherwise similar to the transgressive deposits.

  16. Butterflied bivalves as paleoenvironmental indicators

    SciTech Connect

    Allmon, R.A.

    1985-01-01

    Fossil bivalves are seldom preserved in a flat-open, yet still articulated position, or butterflied. A study of butterflied bivalves in the Delphi Station of the Hamilton Fm. suggests that this preservation mode is limited to one or possibly two sedimentary environments: deltaic and fluvial. Three parameters control the mode of preservation of fossil bivalves: 1) rate of sedimentation, 2) depth of bioturbation, and 3) time of ligament failure. Using these three parameters a model for the occurrence of butterflied bivalves can be constructed: bioturbation depth divided by sedimentation rate gives the disturbance time (DST), during which shells on one bedding plane would be subject to reworking. This can be seen as a time window into which ligament failure times - or disarticulation time (DAT) - can be fitted. If DATreworking of the valves can occur. This model suggest that butterflied bivalves may be used as partial indicators of conditions prevailing in environments of deposition.

  17. Distribution and textural character of surficial sediments, Isles Dernieres to Ship Shoal region, Louisiana

    SciTech Connect

    Williams, S.J.; Circe, R. ); Penland, S. )

    1989-09-01

    Since 1986, the US Geological Survey and the Louisiana Geological Survey have undertaken field studies of the physical processes responsible for the widespread and extremely rapid coastal erosion of Louisiana's barriers along the Mississippi River delta plain coast. The study area encompasses the coastal and inner shelf region from Raccoon Point to Sandy Point and includes a database of 12-m long vibracores, surface grab samples, sidescan sonar, high resolution seismic reflection profiles, and precision hydrographic profiles. This paper presents results in the coastal-shelf sector that includes the Isles Dernieres barrier island chain seaward almost 30 km to Ship Shoal. The surface and near-surface sediments of the region reflect fluvial and nearshore marine origin with pervasive evidence of winnowing and reworking by marine processes associated with frequent tropical storms and the passage of winter cold fronts. Beach sediments are remarkably uniform in grain size (fine quartz sand), except for the often abundant presence of carbonate shell debris, and are generally well to very well sorted. The shoreface and inner shelf are mantled with muddy sands and sandy muds, whereas, Ship Shoal is almost wholly fine quartz sand, similar in many sedimentologic respects to the Isles Dernieres. The results are consistent with the model of coastal evolution, presented in 1988, in which Ship Shoal is the prototypical example of a drowned coastal barrier undergoing submarine reworking and landward migration in pace with the rapid rates of sea level rise and subsidence.

  18. A new ichnospecies of Nereites from carboniferous tidal-flat facies of Eastern Kansas, USA: Implications for the Nereites-Neonereites debate

    USGS Publications Warehouse

    Mangano, M.G.; Buatois, L.A.; Maples, C.G.; West, R.R.

    2000-01-01

    Predominantly horizontal, gently curved to slightly sinuous traces constituting uniserial rows of imbricated, subspherical sediment pads occur in Pennsylvanian tidal-flat facies of eastern Kansas. These traces exhibit a complex, actively filled internal structure. The presence of a median tunnel enveloped by overlapping pads of reworked sediment indicates that these biogenic structures should be included in the ichnogenus Nereites MacLeay in Murchison, 1839. A new ichnospecies, N. imbricata, is erected. Externally, Nereites imbricata differs from the other Nereites ichnospecies by the large, tightly packed, imbricated pads that commonly result in an annulated appearance on bedding-planes. Internally, obliquely arranged, arcuate lamiliae envelope the median tunnel and tend to follow the outline of the external semispherical pads. Additionally, the behavioral pattern reflected by N. imbricata is less specialized than that of the other Nereites ichnospecies. Eione monoliformis Tate, 1859 resembles N. imbricata in general appearance, but lack the diagnostic Nereites internal structure, and is invariably preserved as positive epireliefs. Occurrence of Nereites imbricata as both median tunnels surrounded by reworked sediment (Nereites preservation) and uniserial rows of imbricated sediment pads (Neonereites preservation) supports the notion that Neonereites Seilacher, 1960 is a preservational variant of Nereites. The ichnogenus Nereites is an eurybathic form and is a common component of Paleozoic shallow-marine facies.

  19. Relationships between benthic communities and sedimentary environments in the Pennsylvanian Finis Shale near Jacksboro, Texas

    SciTech Connect

    Lobza, V.; Schieber, J. . Dept. of Geology)

    1993-02-01

    In a new complete exposure near Jacksboro, unweathered and highly fossiliferous Finis Shale overlies greenish laminated shales with mudcracks, and has a transgressive sandstone at the base. Five or more superimposed fossil assemblages can be distinguished. The basal sandstone is overlain by a thin red mudstone with calcareous concretions and abundant Myalina shells (very shallow water), followed by a thin sandy mudstone bed that contains abundant shell fragments and fusulinids. Then follows a black to dark-gray shale unit with abundant conularids, brachiopods, fossil seed pods and wood fragments (pyritic preservation). Modern analogs suggest that the latter might have been reworked from mangrove soils in the course of transgression. The next higher unit is a thin, highly fossiliferous horizon of light gray shale with phosphatic nodules and abundant evidence of erosion and reworking (disarticulated and broken brachiopod shells, epibionts on nodules). The uppermost unit is a dark gray shale with a brachiopod and bivalve dwarf fauna at the bottom, changing upwards into an assemblage where in contrast very large specimens are conspicuous in addition to rugose corals and soft bottom sponges. Faunal and sedimentological characteristics such as degree of bioturbation, population density, dwarf faunas, shell morphology (e.g. thin vs massive shells and spine development in brachiopods), and faunal assemblages reflect a complex interplay of oxygen levels, food supply, strength of bottom currents, turbidity, and substrate properties (firm vs soft). Careful examination of these characteristics allows detailed reconstruction of living conditions and depositional environments of a Pennsylvanian core shale.

  20. (abstract) Mission Operations and Control Assurance: Flight Operations Quality Improvements

    NASA Technical Reports Server (NTRS)

    Welz, Linda L.; Bruno, Kristin J.; Kazz, Sheri L.; Witkowski, Mona M.

    1993-01-01

    Mission Operations and Command Assurance (MO&CA), a recent addition to flight operations teams at JPL. provides a system level function to instill quality in mission operations. MO&CA's primary goal at JPL is to help improve the operational reliability for projects during flight. MO&CA tasks include early detection and correction of process design and procedural deficiencies within projects. Early detection and correction are essential during development of operational procedures and training of operational teams. MO&CA's effort focuses directly on reducing the probability of radiating incorrect commands to a spacecraft. Over the last seven years at JPL, MO&CA has become a valuable asset to JPL flight projects. JPL flight projects have benefited significantly from MO&CA's efforts to contain risk and prevent rather than rework errors. MO&CA's ability to provide direct transfer of knowledge allows new projects to benefit directly from previous and ongoing experience. Since MO&CA, like Total Quality Management (TQM), focuses on continuous improvement of processes and elimination of rework, we recommend that this effort be continued on NASA flight projects.

  1. Microstructural and fabric studies from the rocks of the Moine Nappe, Eriboll, NW Scotland

    NASA Astrophysics Data System (ADS)

    Evans, D. J.; White, S. H.

    Microstructures and quartz c-axis fabric diagrams from mylonites and psammitic Moine schists, collected in traverses across the lower levels of the Moine Nappe in the Eriboll area, are presented. On approaching the Moine Thrust from the Kyle of Tongue, the following microstructural sequence is encountered: interlayered coarse grained biotite psammitic and schistose tectonites being in part mylonitic with two platy slide zones, one containing biotite and the other only muscovite and chlorite and both showing quartz microstructures indicative of post-tectonic relaxation; these pass into more mylonitic rocks nearer the thrust zone which in turn passes into the main chlorite-grade mylonite belt and finally, adjacent to the Moine Thrust, into reworked lower chlorite grade mylonites. Although there is some local variation, the overall quartz c-axis fabric is an incomplete asymmetric type I girdle. The main variation is the development of type II girdles in the reworked, ultrafine grained mylonites. The extent of the mylonitization is more extensive than previously reported. Studies of folds within the mylonite belt have revealed eye structures and small-scale folds; many are sheath folds. They cannot be unequivocally correlated with large-scale recumbent folds within the Moine Nappe. The results presented indicate that mylonitization is not limited to a single phase, and raises the possibility that there may be earlier Caledonian or possibly Precambrian structural elements present in the Eriboll region Moines prior to much of the mylonitization.

  2. Hierarchy of sedimentary discontinuity surfaces and condensed beds from the middle Paleozoic of eastern North America: Implications for cratonic sequence stratigraphy

    USGS Publications Warehouse

    McLaughlin, P.I.; Brett, Carlton E.; Wilson, M.A.

    2008-01-01

    Sedimentological analyses of middle Paleozoic epeiric sea successions in North America suggest a hierarchy of discontinuity surfaces and condensed beds of increasing complexity. Simple firmgrounds and hardgrounds, which are comparatively ephemeral features, form the base of the hierarchy. Composite hardgrounds, reworked concretions, authigenic mineral crusts and monomictic intraformational conglomerates indicate more complex histories. Polymictic intraformational conglomerates, ironstones and phosphorites form the most complex discontinuity surfaces and condensed beds. Complexity of discontinuities is closely linked to depositional environments duration of sediment starvation and degree of reworking which in turn show a relationship to stratigraphic cyclicity. A model of cratonic sequence stratigraphy is generated by combining data on the complexity and lateral distribution of discontinuities in the context of facies successions. Lowstand, early transgressive and late transgressive systems tracts are representative of sea-level rise. Early and late transgressive systems tracts are separated by the maximum starvation surface (typically a polymictic intraformational conglomerate or condensed phosphorite), deposited during the peak rate of sea-level rise. Conversely the maximum flooding surface, representing the highest stand of sea level, is marked by little to no break in sedimentation. The highstand and falling stage systems tracts are deposited during relative sea-level fall. They are separated by the forced-regression surface, a thin discontinuity surface or condensed bed developed during the most rapid rate of sea-level fall. The lowest stand of sea level is marked by the sequence boundary. In subaerially exposed areas it is occasionally modified as a rockground or composite hardground.

  3. Neogene-Quaternary depositional history of the eastern US continental rise seaward of the Washington-Norfolk Canyon systems

    SciTech Connect

    Locker, S.D.; Laine, E.P.

    1985-01-01

    High quality, digitally recorded and processed, water gun and air gun seismic reflection data collected seaward of the present position of the Washington-Norfolk canyon systems reveals new information on the development of the continental rise. This includes insight into the depositional history of the Washington-Norfolk fan system and the relative importance of gravity flow depositional processes versus abyssal bottom current reworking during rise development. Three major post-Horizon A/sup u/ accretionary sequences describe major changes in depositional processes and history within the region. Accretionary sequence I (early to middle Miocene) is characterized by the initial development of a depositional bulge seaward of the Washington-Norfolk canyon systems which is modified by bottom currents on the lower-most rise to form a proto-Hatteras Outer Ridge. The predominance of chaotic and hummocky seismic facies suggests widespread reworking by abyssal bottom currents. Accretionary sequence II (middle Miocene to late Pliocene) in this area is characterized by sediment waves (lower rise) and smooth, southward dipping, parallel reflectors associated with a thick central rise drift(.) deposit off the Hudson system to the North. Washington-Norfolk fan development appears less important during this time. Bottom currents are active, but more depositional in nature than during accretionary sequence I. Accretionary sequence III (late Pliocene to Present) is marked by gravity flow processes and distinct development of the Washington-Norfolk fan on the central rise.

  4. The Cosmonaut Sea Wedge

    USGS Publications Warehouse

    Solli, K.; Kuvaas, B.; Kristoffersen, Y.; Leitchenkov, G.; Guseva, J.; Gandyukhin, V.

    2007-01-01

    A set of multi-channel seismic profiles (~15000 km) acquired by Russia, Norway and Australia has been used to investigate the depositional evolution of the Cosmonaut Sea margin of East Antarctica. We recognize a regional sediment wedge below the upper part of the continental rise. The wedge, herein termed the Cosmonaut Sea Wedge, is positioned stratigraphically underneath the inferred glaciomarine section and extends for at least 1200 km along the continental margin and from 80 to about 250 km seaward or to the north. Lateral variations in the growth pattern of the wedge indicate several overlapping depocentres, which at their distal northern end are flanked by elongated mounded drifts and contourite sheets. The internal stratification of the mounded drift deposits suggests that westward flowing bottom currents reworked the marginal deposits. The action of these currents together with sea-level changes is considered to have controlled the growth of the wedge. We interpret the Cosmonaut Sea Wedge as a composite feature comprising several bottom current reworked fan systems.

  5. Federal Directions in Radiation Regulations: Making the "Old" New Again.

    PubMed

    Edwards, Jonathan D

    2016-02-01

    The radiation regulatory scheme in the United States must periodically evolve and adapt to ensure that public health, workers, and the environment are properly protected in view of accepted societal values and the advance of science, technology, and medical practices. Federal regulators must use best judgment in weighing a multitude of factors and considerations. In the early 21st century, a few dependable but tired and antiquated "workhorses" of regulation have been reworked already--but many more remain that likely need reworking. Three primary points of discussion on current directional influences on federal radiation regulation merit examination: • In 2015, what are the stressors driving societal and policy changes and how might these dynamics be forcing reexamination of old regulations? • What are the things that make a "good" regulation and an effective rule? • What are the thorny issues that the federal government is wrestling with and what are some of the notable activities in federal radiation regulations and guidance that are underway? This journal article was presented at the 2015 Annual Meeting of the National Council on Radiation Protection and Measurements and served as a broad overview of federal regulatory actions and issues.

  6. High-resolution mapping of glacial landforms in the North Alpine Foreland, Austria

    NASA Astrophysics Data System (ADS)

    Salcher, Bernhard C.; Hinsch, Ralph; Wagreich, Michael

    2010-10-01

    In this study results from traditional field mapping were merged with precise elevation information from airborne LiDAR (Light detection and ranging) surveys. Morphological and sedimentological data provide new results from the Austrian (eastern) part of the Salzach piedmont glacier during times of and shortly after the Last Glacial Maximum (LGM). The variations in meltwater discharge had a major impact on the development of glacial landforms. In areas with high meltwater supply erosional or debris reworking processes play a major role, represented by drainage channels, drumlins and kettled, low relief hummocky moraine with low slope angles. Low discharge areas are associated with distinct depositional forms such as high relief end moraines (up to 30 m) and hummocky moraine (averaging 20 m) with high slope angles. Isolated conical kames may reach heights up to 45 m. Fluvial activity is supposed to rise towards the end of the glacial cycle causing high melting rates and comprehensive debris reworking. The formation of terminal lakes and associated widespread, inorganic lake clays are the last deposits within the study area before the Salzach Glacier completely receded to its main valley. The survey of glacial landforms through the combination of field mapping and high-resolution DEM derived from airborne LiDAR missions gives precise information on transport and deposition during the last glacial cycle of the eastern Salzach Glacier piedmont lobe.

  7. High resolution shallow geologic characterization of a late Pleistocene eolian environment using ground penetrating radar and optically stimulated luminescence techniques: North Carolina, USA

    USGS Publications Warehouse

    Mallinson, D.; Mahan, S.; Moore, Christine

    2008-01-01

    Geophysical surveys, sedimentology, and optically-stimulated luminescence age analyses were used to assess the geologic development of a coastal system near Swansboro, NC. This area is a significant Woodland Period Native American habitation and is designated the "Broad Reach" archaeological site. 2-d and 3-d subsurface geophysical surveys were performed using a ground penetrating radar system to define the stratigraphic framework and depositional facies. Sediment samples were collected and analyzed for grain-size to determine depositional environments. Samples were acquired and analyzed using optically stimulated luminescence techniques to derive the depositional age of the various features. The data support a low eolian to shallow subtidal coastal depositional setting for this area. Li-DAR data reveal ridge and swale topography, most likely related to beach ridges, and eolian features including low-relief, low-angle transverse and parabolic dunes, blowouts, and a low-relief eolian sand sheet. Geophysical data reveal dominantly seaward dipping units, and low-angle mounded features. Sedimentological data reveal mostly moderately-well to well-sorted fine-grained symmetrical to coarse skewed sands, suggesting initial aqueous transport and deposition, followed by eolian reworking and bioturbation. OSL data indicate initial coastal deposition prior to ca. 45,000 yBP, followed by eolian reworking and low dune stabilization at ca. 13,000 to 11,500 yBP, and again at ca. 10,000 yBP (during, and slightly after the Younger Dryas chronozone).

  8. Dynamics of nonmigrating mid-channel bar and superimposed dunes in a sandy-gravelly river (Loire River, France)

    NASA Astrophysics Data System (ADS)

    Wintenberger, Coraline L.; Rodrigues, Stéphane; Claude, Nicolas; Jugé, Philippe; Bréhéret, Jean-Gabriel; Villar, Marc

    2015-11-01

    A field study was carried out to investigate the dynamics during floods of a nonmigrating, mid-channel bar of the Loire River (France) forced by a riffle and renewed by fluvial management works. Interactions between the bar and superimposed dunes developed from an initial flat bed were analyzed during floods using frequent mono- and multibeam echosoundings, Acoustic Doppler Profiler measurements, and sediment grain-size analysis. When water left the bar, terrestrial laser scanning and sediment sampling documented the effect of post-flood sediment reworking. During floods a significant bar front elongation, spreading (on margins), and swelling was shown, whereas a stable area (no significant changes) was present close to the riffle. During low flows and falling limbs of floods, intense sediment reworking on the top of the bar and lateral scouring occurred. Hydrological variations controlled the sediment supply (in terms of phasing, quantity, and grain size) delivered by surrounding channels during floods and thus superimposed dune development. Their development was also linked to the sediment availability (armor layers, riffle proximity). Their relatively constant height highlights a preferential adaptation on dune length during floods. The role of each morphological forcing parameters (riffle vs. channel widening and curvature) on the bar dynamics and evolution is stage dependent; the shape, dynamics, and long-term morphological evolution of the bar and of the river reach (surrounding islands, channel translation) mainly depends on the presence of the natural riffle.

  9. Middle Eocene seagrass facies from Apennine carbonate platforms (Italy)

    NASA Astrophysics Data System (ADS)

    Tomassetti, Laura; Benedetti, Andrea; Brandano, Marco

    2016-04-01

    Two stratigraphic sections located in the Latium-Abruzzi (Monte Porchio, Central Apennines, Central Italy) and in the Apulian carbonate platform (S. Cesarea-Torre Tiggiano, Salento, Southern Italy) were measured and sampled to document the sedimentological characteristic and the faunistic assemblages of Middle Eocene seagrass deposits. The faunistic assemblages are dominated by porcellaneous foraminifera Orbitolites, Alveolina, Idalina, Spiroloculina, Quinqueloculina, Triloculina and abundant hooked-shaped gypsinids, associated with hooked red algae and green algae Halimeda. Fabiania, rotaliids and textulariids as well as nummulitids are subordinated. The samples were assigned to Lutetian (SBZ13-16) according to the occurrence of Nummulites cf. lehneri, Alveolina ex. gr. elliptica, Idalina berthelini, Orbitolites complanatus, Slovenites decastroi and Medocia blayensis. At Santa Cesarea reticulate nummulites occur in association with Alveolina spp. and Halkyardia minima marking the lower Bartonian (SBZ17). Three main facies associations have been recognised: I) larger porcellaneous foraminiferal grainstones with orbitolitids and alveolinids deposited into high-energy shallow-water settings influenced by wave processes that reworked the sediments associated with a seagrass; II) grainstone to packstone with small porcellaneous foraminifera and abundant permanently-attached gypsinids deposited in a more protected (e.g., small embayment) in situ vegetated environment; III) bioclastic packstone with parautochthonous material reworked from the seagrass by rip currents and accumulated into rip channels in a slightly deeper environment. The biotic assemblages suggest that the depositional environment is consistent with tropical to subtropical vegetated environments within oligotrophic conditions.

  10. A Lower Permian sandwave-containing shelf sequence exposed at Zungwini Mountain, Republic of South Africa

    NASA Astrophysics Data System (ADS)

    Smith, A. M.

    1989-08-01

    As a result of railway excavations the Pietermaritzburg Shale-Vryheid Formation transition is spectacularly exposed on the southern slope of Zungwini Mountain. Nine facies and three facies associations are recognised. Deposition occurred in a palaeoshelf and offshore setting. The reconstructed coastline was SW-NE with land to the northwest. The inner shelf was tide- and the outer-shelf storm-influenced. Fluvial input supplied sediment which was reworked into flood-tidal sandwaves, probably within the confines of an estuary. A rising sea level brought the sandwaves into the realm of a more distal, coast-parallel, storm-tidal current regime where reworking of the sediment occurred. Intense storm-augmented tidal currents swept some of the better-sorted material seaward to be deposited as storm layers in the inner and outer shelf. These same currents formed the low-density turbidites and sediment plumes from which the offshore argillaceous deposits were formed. The shelf edge poorly sorted rhythmite facies may have developed from sediment flushed out of the rivers during flood or from the flood-tidal sandwave system as a result of exceptional coastal storms.

  11. Stratigraphic framework maps of the nearshore area of southern Long Island from Fire Island to Montauk Point, New York

    USGS Publications Warehouse

    Foster, David S.; Swift, B. Ann; Schwab, William C.

    1999-01-01

    The maps presented in this report (depth to Coastal Plain unconformity, Quaternary sediment thickness, paleochannel thickness, and modern sand thickness) are helpful for determining sand-resource availability for beach nourishment programs and understanding the influence that the inner-shelf framework of southern Long Island has on coastal processes and evolution. The maps showing structure of the Coastal Plain unconformity and thickness of overlying Quaternary sediment delineate the framework of the coastal region. The map showing the distribution and thickness of paleochannel fill indicates areas not suitable as sources for beach nourishment, assuming the channels contain muddy estuarine deposits. The areas between channels are Pleistocene glacial deposits and probably consist of coarse sediment that may be suitable for beach nourishment. These coarser-grained glacial deposits are the source for modern sand deposits. The modern sands have been reworked primarily from glacial deposits and a Cretaceous outcrop off Watch Hill. These reworked deposits provide well-sorted clean sand that have and will provide nourishment for southern Long Island beaches.

  12. Continuous Risk Management: An Overview

    NASA Technical Reports Server (NTRS)

    Rosenberg, Linda; Hammer, Theodore F.

    1999-01-01

    Software risk management is important because it helps avoid disasters, rework, and overkill, but more importantly because it stimulates win-win situations. The objectives of software risk management are to identify, address, and eliminate software risk items before they become threats to success or major sources of rework. In general, good project managers are also good managers of risk. It makes good business sense for all software development projects to incorporate risk management as part of project management. The Software Assurance Technology Center (SATC) at NASA GSFC has been tasked with the responsibility for developing and teaching a systems level course for risk management that provides information on how to implement risk management. The course was developed in conjunction with the Software Engineering Institute at Carnegie Mellon University, then tailored to the NASA systems community. This is an introductory tutorial to continuous risk management based on this course. The rational for continuous risk management and how it is incorporated into project management are discussed. The risk management structure of six functions is discussed in sufficient depth for managers to understand what is involved in risk management and how it is implemented. These functions include: (1) Identify the risks in a specific format; (2) Analyze the risk probability, impact/severity, and timeframe; (3) Plan the approach; (4) Track the risk through data compilation and analysis; (5) Control and monitor the risk; (6) Communicate and document the process and decisions.

  13. Sidescan-Sonar Imagery and Surficial Geologic Interpretations of the Sea Floor in Western Rhode Island Sound

    USGS Publications Warehouse

    McMullen, K.Y.; Poppe, L.J.; Haupt, T.A.; Crocker, J.M.

    2009-01-01

    The U.S. Geological Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA) have been working together to interpret sea-floor geology along the northeastern coast of the United States. In 2004, the NOAA Ship RUDE completed survey H11322, a sidescan-sonar and bathymetric survey that covers about 60 square kilometers of the sea floor in western Rhode Island Sound. This report interprets sidescan-sonar and bathymetric data from NOAA survey H11322 to delineate sea-floor features and sedimentary environments in the study area. Paleozoic bedrock and Cretaceous Coastal Plain sediments in Rhode Island Sound underlie Pleistocene glacial drift that affects the distribution of surficial Holocene marine and transgressional sediments. The study area has three bathymetric highs separated by a channel system. Features and patterns in the sidescan-sonar imagery include low, moderate, and high backscatter; sand waves; scarps; erosional outliers; boulders; trawl marks; and dredge spoils. Four sedimentary environments in the study area, based on backscatter and bathymetric features, include those characterized by erosion or nondeposition, coarse-grained bedload transport, sorting and reworking, and deposition. Environments characterized by erosion or nondeposition and coarse-grained bedload transport are located in shallower areas and environments characterized by deposition are located in deeper areas; environments characterized by sorting and reworking processes are generally located at moderate depths.

  14. Surficial geology of the sea floor in west-central Long Island Sound as shown by sidescan-sonar imagery

    USGS Publications Warehouse

    McMullen, K.Y.; Poppe, L.J.; DiGiacomo-Cohen, M. L.; Moser, M.S.; Christman, E.B.

    2005-01-01

    We used sidescan-sonar imagery detailing almost 300 km2 of the sea floor in west-central Long Island Sound in conjunction with bathymetry, sediment samples, bottom video, and seismic data to interpret the area's surficial geology. The distribution of sediments and sedimentary environments interpreted from these data sets represents the Quaternary geology, regional bathymetry, and effects of modern tidal- and wave-driven currents. Four distinct sedimentary environments consisting of 1) fine-grained deposition, 2) sorting and reworking, 3) coarse-grained bedload transport, and 4) erosion or nondeposition, were identified and mapped. Relatively low-energy environments prevail where deposition of clayey silts occurs in deeper water throughout the central part of the study area, and in the protected areas of the far northeastern corner. As low-energy environments transition to relatively high-energy environments, sorting and reworking of sand, silty sand, and sand-silt-clay takes place on the flanks of the shoals and over smaller bathymetric highs. Environments of coarse-grained bedload transport, distinguished by sandy sediments with current-derived bedforms, are located on an unnamed shoal in the northwestern part of the study area and directly to the south of this on Stratford Shoal. High-energy conditions are reflected by environments of erosion or nondeposition, which occur on bathymetric highs where gravel and gravelly sediments are present.

  15. New cosmogenic burial ages for Sterkfontein Member 2 Australopithecus and Member 5 Oldowan.

    PubMed

    Granger, Darryl E; Gibbon, Ryan J; Kuman, Kathleen; Clarke, Ronald J; Bruxelles, Laurent; Caffee, Marc W

    2015-06-01

    The cave infills at Sterkfontein contain one of the richest assemblages of Australopithecus fossils in the world, including the nearly complete skeleton StW 573 ('Little Foot') in its lower section, as well as early stone tools in higher sections. However, the chronology of the site remains controversial owing to the complex history of cave infilling. Much of the existing chronology based on uranium-lead dating and palaeomagnetic stratigraphy has recently been called into question by the recognition that dated flowstones fill cavities formed within previously cemented breccias and therefore do not form a stratigraphic sequence. Earlier dating with cosmogenic nuclides suffered a high degree of uncertainty and has been questioned on grounds of sediment reworking. Here we use isochron burial dating with cosmogenic aluminium-26 and beryllium-10 to show that the breccia containing StW 573 did not undergo significant reworking, and that it was deposited 3.67 ± 0.16 million years ago, far earlier than the 2.2 million year flowstones found within it. The skeleton is thus coeval with early Australopithecus afarensis in eastern Africa. We also date the earliest stone tools at Sterkfontein to 2.18 ± 0.21 million years ago, placing them in the Oldowan at a time similar to that found elsewhere in South Africa at Swartkans and Wonderwerk.

  16. Pushing Back the Origin of Bantu Lexicography: The Vocabularium Congense of 1652, 1928, 2012

    PubMed Central

    De Kind, Jasper; de Schryver, Gilles-Maurice; Bostoen, Koen

    2013-01-01

    In this article, the oldest Bantu dictionary hitherto known is explored, that is the Vocabularium Latinum, Hispanicum, e Congense, handed down to us through a manuscript from 1652 by the Flemish Capuchin Joris van Gheel, missionary in the Kongo (present-day north-western Angola and the southern part of the Lower Congo Province of the DRC). The manuscript was heavily reworked by the Belgian Jesuits Joseph van Wing and Constant Penders, and published in 1928. Both works are currently being digitized, linked and added to an interlingual and multimedia database that revolves around Kikongo and the early history of the Kongo kingdom. In Sections 1 and 2 the origins of Bantu lexicography in general and of Kikongo metalexicography in particular are revisited. Sections 3 and 4 are devoted to a study of Van Gheel’s manuscript and an analysis of Van Wing and Penders’ rework. In Sections 5 and 6 translation equivalence and lexicographical structure in both dictionaries are scrutinized and compared. In Section 7, finally, all the material is brought together. PMID:23814547

  17. Pushing Back the Origin of Bantu Lexicography: The Vocabularium Congense of 1652, 1928, 2012.

    PubMed

    De Kind, Jasper; de Schryver, Gilles-Maurice; Bostoen, Koen

    2012-12-01

    In this article, the oldest Bantu dictionary hitherto known is explored, that is the Vocabularium Latinum, Hispanicum, e Congense, handed down to us through a manuscript from 1652 by the Flemish Capuchin Joris van Gheel, missionary in the Kongo (present-day north-western Angola and the southern part of the Lower Congo Province of the DRC). The manuscript was heavily reworked by the Belgian Jesuits Joseph van Wing and Constant Penders, and published in 1928. Both works are currently being digitized, linked and added to an interlingual and multimedia database that revolves around Kikongo and the early history of the Kongo kingdom. In Sections 1 and 2 the origins of Bantu lexicography in general and of Kikongo metalexicography in particular are revisited. Sections 3 and 4 are devoted to a study of Van Gheel's manuscript and an analysis of Van Wing and Penders' rework. In Sections 5 and 6 translation equivalence and lexicographical structure in both dictionaries are scrutinized and compared. In Section 7, finally, all the material is brought together.

  18. Multistress effects on goldfish (Carassius auratus) behavior and metabolism.

    PubMed

    Gandar, Allison; Jean, Séverine; Canal, Julie; Marty-Gasset, Nathalie; Gilbert, Franck; Laffaille, Pascal

    2016-02-01

    Crossed effects between climate change and chemical pollutions were identified on community structure and ecosystem functioning. Temperature rising affects the toxic properties of pollutants and the sensitiveness of organisms to chemicals stress. Inversely, chemical exposure may decrease the capacity of organisms to respond to environmental changes. The aim of our study was to assess the individual and crossed effects of temperature rising and pesticide contamination on fish. Goldfish, Carassius auratus, were exposed during 96 h at two temperatures (22 and 32 °C) to a mixture of common pesticides (S-metolachlor, isoproturon, linuron, atrazine-desethyl, aclonifen, pendimethalin, and tebuconazol) at two environmentally relevant concentrations (total concentrations MIX1 = 8.4 μg L(-1) and MIX2 = 42 μg L(-1)). We investigated the sediment reworking behavior, which has a major ecological functional role. We also focused on three physiological traits from the cellular up to the whole individual level showing metabolic status of fish (protein concentration in liver and muscle, hepatosomatic index, and Fulton's condition factor). Individual thermal stress and low concentrations of pesticides decreased the sediment reworking activity of fish and entrained metabolic compensation with global depletion in energy stores. We found that combined chemical and thermal stresses impaired the capacity of fish to set up an efficient adaptive response. Our results strongly suggest that temperature will make fish more sensitive to water contamination by pesticides, raising concerns about wild fish conservation submitted to global changes.

  19. Federal Directions in Radiation Regulations: Making the "Old" New Again.

    PubMed

    Edwards, Jonathan D

    2016-02-01

    The radiation regulatory scheme in the United States must periodically evolve and adapt to ensure that public health, workers, and the environment are properly protected in view of accepted societal values and the advance of science, technology, and medical practices. Federal regulators must use best judgment in weighing a multitude of factors and considerations. In the early 21st century, a few dependable but tired and antiquated "workhorses" of regulation have been reworked already--but many more remain that likely need reworking. Three primary points of discussion on current directional influences on federal radiation regulation merit examination: • In 2015, what are the stressors driving societal and policy changes and how might these dynamics be forcing reexamination of old regulations? • What are the things that make a "good" regulation and an effective rule? • What are the thorny issues that the federal government is wrestling with and what are some of the notable activities in federal radiation regulations and guidance that are underway? This journal article was presented at the 2015 Annual Meeting of the National Council on Radiation Protection and Measurements and served as a broad overview of federal regulatory actions and issues. PMID:26717168

  20. New cosmogenic burial ages for Sterkfontein Member 2 Australopithecus and Member 5 Oldowan.

    PubMed

    Granger, Darryl E; Gibbon, Ryan J; Kuman, Kathleen; Clarke, Ronald J; Bruxelles, Laurent; Caffee, Marc W

    2015-06-01

    The cave infills at Sterkfontein contain one of the richest assemblages of Australopithecus fossils in the world, including the nearly complete skeleton StW 573 ('Little Foot') in its lower section, as well as early stone tools in higher sections. However, the chronology of the site remains controversial owing to the complex history of cave infilling. Much of the existing chronology based on uranium-lead dating and palaeomagnetic stratigraphy has recently been called into question by the recognition that dated flowstones fill cavities formed within previously cemented breccias and therefore do not form a stratigraphic sequence. Earlier dating with cosmogenic nuclides suffered a high degree of uncertainty and has been questioned on grounds of sediment reworking. Here we use isochron burial dating with cosmogenic aluminium-26 and beryllium-10 to show that the breccia containing StW 573 did not undergo significant reworking, and that it was deposited 3.67 ± 0.16 million years ago, far earlier than the 2.2 million year flowstones found within it. The skeleton is thus coeval with early Australopithecus afarensis in eastern Africa. We also date the earliest stone tools at Sterkfontein to 2.18 ± 0.21 million years ago, placing them in the Oldowan at a time similar to that found elsewhere in South Africa at Swartkans and Wonderwerk. PMID:25830884

  1. Neoselachians and Chimaeriformes (Chondrichthyes) from the latest Cretaceous-Paleogene of Sierra Baguales, southernmost Chile. Chronostratigraphic, paleobiogeographic and paleoenvironmental implications

    NASA Astrophysics Data System (ADS)

    Otero, Rodrigo A.; Oyarzún, José Luis; Soto-Acuña, Sergio; Yury-Yáñez, Roberto E.; Gutierrez, Nestor M.; Le Roux, Jacobus P.; Torres, Teresa; Hervé, Francisco

    2013-12-01

    This paper discusses a well-represented fossil record of cartilaginous fishes (Chondrichthyes) from southern South America. The recovered samples allow the recognition of three assemblages with chronostratigraphic and paleogeographic value: i) typical Maastrichtian sharks and rays with affinities to eastern Pacific fauna, including the taxa Ischyrhiza chilensis, Serratolamna serrata, Centrophoroides sp. associated to Carcharias sp., and Dasyatidae indet.; ii) a scarce reworked assemblage of Paleocene-Early Eocene age including the taxa Otodus obliquus and Megascyliorhinus cooperi; iii) a rich assemblage with reworked taxa of Early to Middle Eocene age, together with autochthonous deposited Middle to Late Eocene taxa with close affinities to paleoichthyofaunas recovered from the North Atlantic, represented by Carcharias 'hopei', Odontaspis winkleri, Carcharoides catticus, Macrorhizodus praecursor, Carcharocles auriculatus, Striatolamia sp., Striatolamia macrota, Hexanchus agassizi, Notorhynchus sp., Myliobatis sp., Abdounia sp., Pristiophorus sp., Squatina sp., cf. Rhizoprionodon sp., Ischyodus sp., and one new species, Jaekelotodus bagualensis sp. nov. The studied samples include for the first time taxa with well established chronostratigraphic resolutions as well as taphonomic information that help clarifying the age of the fossil-bearing units. In addition, they provide relevant information about the evolution of the Magallanes (=Austral) Basin from the Upper Cretaceous to the Paleogene, suggesting a probable connection with the Quiriquina Basin of south-central Chile during the latest Cretaceous. Finally, the studied assemblages indicate a latitudinal pattern of distribution that provides valuable data on the environmental evolution and temperature of southern South America during the Paleogene.

  2. Meridiani Planum sediments on Mars formed through weathering in massive ice deposits

    NASA Astrophysics Data System (ADS)

    Niles, Paul B.; Michalski, Joseph

    2009-03-01

    The sulphate-rich deposits at Meridiani Planum, Mars, discovered by the rover Opportunity, were proposed to be playa evaporites that had been reworked by eolian processes. Alternative hypotheses include volcanic or impact-driven formation of the sediments. Here we argue that the cation chemistry, scale, mineralogy and structure of the Meridiani sedimentary deposits are best explained by eolian or impact-driven reworking of the sublimation residue from a large-scale deposit consisting of dust and ice. We suggest that silicate material underwent significant acid weathering inside the ice deposit when thin films of water, formed through radiant heating, enabled the reaction between silicate material and sulphate-rich aerosols deposited from the atmosphere. The massive ice deposit could have formed during a period of high obliquity or polar wander, and subsequently sublimed away when obliquity changed or the pole moved to a new location. We propose acid weathering inside massive ice deposits as an explanation for the formation of many of the sulphate-rich layered deposits on Mars, which share many characteristics, including mineralogy, structure, erosional characteristics and size, with the sediments found at Meridiani Planum.

  3. Petrographic analyses of Knobloch coal seam (Paleocene), Powder River County, southeastern Montana

    SciTech Connect

    Daniel, J.A.

    1986-08-01

    A single core of Knobloch coal from Powder River County, southeast Montana, was drilled to obtain samples for coal quality studies. The coal occurs in the lower Tongue River Member of the Paleocene Fort Union Formation. The Knobloch coal core (63 ft long) was divided into 1-ft increments and analyzed using chemical and petrographic methods. Definite variations in maceral content were seen. Preliminary studies show relationship between ash, gelinite, inertinite, and humodetrinite contents. A zone of low gelinite, low humodetrinite, and high inertinite, located in the lower quarter of the seam, implies a period of severe oxidation occurred, possibly as swamp fires. Four zones of high inertinite and high humodetrinite (three in the upper half and one in the lower half of the seam) indicate fluctuations in the water table, allowing moderate oxidation and weathering of plant material and subsequent mechanical reworking of humic grains. Near the center of the seam, a zone of high inertinite, high humodetrinite, and high ash content suggests water levels were high enough to allow significant sediment influx as well as reworking of the humic materials. These conclusions suggest the Knobloch coal is autochthonous and hypautochthonous in origin, a result of several water-table fluctuations and/or climatic changes due to drought.

  4. A late Albian ammonite assemblage from the mid- Cretaceous succession at Annopol, Poland

    NASA Astrophysics Data System (ADS)

    Kennedy, William J.; Machalski, Marcin

    2015-12-01

    A previously unrecorded ammonite assemblage, comprising Lepthoplites sp., Callihoplites tetragonus (Seeley, 1865), C. cf. tetragonus, Arrhaphoceras cf. substuderi Spath, 1923, Cantabrigites sp., Stoliczkaiella (Stoliczkaiella) sp., Hamites cf. duplicatus Pictet and Campiche, 1861, H. cf. subvirgulatus Spath, 1941, and H. cf. venetzianus Pictet, 1847, is described from the mid-Cretaceous condensed succession at Annopol, Poland. These specimens are preserved as pale phosphates or sandstone moulds in a bed of reworked phosphatic nodules near the top of the Albian. This assemblage has many species in common with the late late Albian faunas from condensed deposits of England, Switzerland, and France. The presence of Callihoplites tetragonus indicates the lowermost upper upper Albian Mortoniceras fallax Zone. The ammonites studied are the youngest elements in the phosphate bed, which also contains taxa as old as the middle Albian Hoplites dentatus Zone. This bed originated through condensation and reworking of nodules and fossils in a period of low net sedimentation rate, being probably a reflection of a sea-level drop at the boundary between the classic ammonite zones of Mortoniceras inflatum and Stoliczkaiella dispar.

  5. Multistress effects on goldfish (Carassius auratus) behavior and metabolism.

    PubMed

    Gandar, Allison; Jean, Séverine; Canal, Julie; Marty-Gasset, Nathalie; Gilbert, Franck; Laffaille, Pascal

    2016-02-01

    Crossed effects between climate change and chemical pollutions were identified on community structure and ecosystem functioning. Temperature rising affects the toxic properties of pollutants and the sensitiveness of organisms to chemicals stress. Inversely, chemical exposure may decrease the capacity of organisms to respond to environmental changes. The aim of our study was to assess the individual and crossed effects of temperature rising and pesticide contamination on fish. Goldfish, Carassius auratus, were exposed during 96 h at two temperatures (22 and 32 °C) to a mixture of common pesticides (S-metolachlor, isoproturon, linuron, atrazine-desethyl, aclonifen, pendimethalin, and tebuconazol) at two environmentally relevant concentrations (total concentrations MIX1 = 8.4 μg L(-1) and MIX2 = 42 μg L(-1)). We investigated the sediment reworking behavior, which has a major ecological functional role. We also focused on three physiological traits from the cellular up to the whole individual level showing metabolic status of fish (protein concentration in liver and muscle, hepatosomatic index, and Fulton's condition factor). Individual thermal stress and low concentrations of pesticides decreased the sediment reworking activity of fish and entrained metabolic compensation with global depletion in energy stores. We found that combined chemical and thermal stresses impaired the capacity of fish to set up an efficient adaptive response. Our results strongly suggest that temperature will make fish more sensitive to water contamination by pesticides, raising concerns about wild fish conservation submitted to global changes. PMID:26272290

  6. The environmental magnetic fingerprint of periglacial loess in Eastern Germany

    NASA Astrophysics Data System (ADS)

    Baumgart, Philipp; Hambach, Ulrich; Meszner, Sascha; Faust, Dominik

    2013-04-01

    In the framework of a comprehensive stratigraphic study of loess Eastern Germany, a detailed rock magnetic study was carried out of four last glacial/interglacial loess-palaeosol sequences. Magnetic susceptibility and laboratory-induced remanences have been determined to compare individual sections and to identify the specific rock magnetic characteristics of the Saxonian Loess Province. According to the model of pedogenic magnetic enhancement, an increasing neoformation of ferrimagnetic minerals in the course of pedogenesis was observed only in the uppermost Late Weichselian lithological units consisting of almost unweathered loess and indicating dryer climatic conditions. In contrast, the rock magnetic characteristics of the lower Middle and Early Weichselian units exhibit a significant destruction of primary magnetic minerals caused by such secondary processes as climatically controlled waterlogging and reworking. The main observation, an increasing ?fd with decreasing ? with stratigraphic depth, argues for a general magnetic depletion in conjunction with decreasing magnetic grain sizes caused by weathering of larger primary particles. The magnetic fingerprint of the Saxonian loess is characterised by prevailing magnetic depletion processes, which effectively rules out the application of the wind vigour model. Moreover, the observed magnetic characteristics differ significantly from that of other loess regions. Therefore, we propose a new magnetic facies model for more humid (Central European) loess provinces dominated by typical periglacial conditions, including widespread permafrost, which control the intense reworking and waterlogging (gleyification) processes.

  7. Taphonomy and paleoecology of nonmarine mollusca: indicators of alluvial plain lacustrine sedimentation, upper part of the Tongue River Member, Fort Union Formation ( Paleocene), Northern Powder River Basin, Wyoming and Montana ( USA).

    USGS Publications Warehouse

    Hanley, J.H.; Flores, R.M.

    1987-01-01

    The composition, species abundances, and spatial and temporal distributions of mollusc assemblages were controlled by the environments in which they lived and the depositional processes that affected the molluscs after death and before final burial. Post-mortem transport, reworking and concentration of shells, and mixing of faunal elements from discrete habitats produced a taphonomic 'overprint' on assemblage characteristics that directly reflects the processes of alluvial plain and floodbasin lacustrine sedimentation. The 'overprint' can be interpreted from outcrop analysis of molluscan biofabric, which consists of: 1) orientation, fragmentation, size-sorting, abrasion, density, and dispersion of shells, 2) the nature and extent of shell-infilling, and 3) ratio of articulated to disarticulated bivalves. Taphonomic characteristics were used with sedimentological properties to differentiate in-place, reworked, transported, and ecologically mixed mollusc assemblages. This study also defines the paleoecology of habitat preferences of mollusc species as a basis for recognition of the environments in which these assemblages were deposited: 1) large floodbasin lakes, 2) small floodbasin lakes, and 3) crevasse deltas and splays. Integration of sedimentology and paleoecology provides an interdisciplinary approach to the interpretation of alluvial environments through time in the Tongue River Member. -Authors

  8. New cosmogenic burial ages for Sterkfontein Member 2 Australopithecus and Member 5 Oldowan

    NASA Astrophysics Data System (ADS)

    Granger, Darryl E.; Gibbon, Ryan J.; Kuman, Kathleen; Clarke, Ronald J.; Bruxelles, Laurent; Caffee, Marc W.

    2015-06-01

    The cave infills at Sterkfontein contain one of the richest assemblages of Australopithecus fossils in the world, including the nearly complete skeleton StW 573 (`Little Foot') in its lower section, as well as early stone tools in higher sections. However, the chronology of the site remains controversial owing to the complex history of cave infilling. Much of the existing chronology based on uranium-lead dating and palaeomagnetic stratigraphy has recently been called into question by the recognition that dated flowstones fill cavities formed within previously cemented breccias and therefore do not form a stratigraphic sequence. Earlier dating with cosmogenic nuclides suffered a high degree of uncertainty and has been questioned on grounds of sediment reworking. Here we use isochron burial dating with cosmogenic aluminium-26 and beryllium-10 to show that the breccia containing StW 573 did not undergo significant reworking, and that it was deposited 3.67 +/- 0.16 million years ago, far earlier than the 2.2 million year flowstones found within it. The skeleton is thus coeval with early Australopithecus afarensis in eastern Africa. We also date the earliest stone tools at Sterkfontein to 2.18 +/- 0.21 million years ago, placing them in the Oldowan at a time similar to that found elsewhere in South Africa at Swartkans and Wonderwerk.

  9. A bioturbation classification of European marine infaunal invertebrates.

    PubMed

    Queirós, Ana M; Birchenough, Silvana N R; Bremner, Julie; Godbold, Jasmin A; Parker, Ruth E; Romero-Ramirez, Alicia; Reiss, Henning; Solan, Martin; Somerfield, Paul J; Van Colen, Carl; Van Hoey, Gert; Widdicombe, Stephen

    2013-10-01

    Bioturbation, the biogenic modification of sediments through particle reworking and burrow ventilation, is a key mediator of many important geochemical processes in marine systems. In situ quantification of bioturbation can be achieved in a myriad of ways, requiring expert knowledge, technology, and resources not always available, and not feasible in some settings. Where dedicated research programmes do not exist, a practical alternative is the adoption of a trait-based approach to estimate community bioturbation potential (BPc). This index can be calculated from inventories of species, abundance and biomass data (routinely available for many systems), and a functional classification of organism traits associated with sediment mixing (less available). Presently, however, there is no agreed standard categorization for the reworking mode and mobility of benthic species. Based on information from the literature and expert opinion, we provide a functional classification for 1033 benthic invertebrate species from the northwest European continental shelf, as a tool to enable the standardized calculation of BPc in the region. Future uses of this classification table will increase the comparability and utility of large-scale assessments of ecosystem processes and functioning influenced by bioturbation (e.g., to support legislation). The key strengths, assumptions, and limitations of BPc as a metric are critically reviewed, offering guidelines for its calculation and application. PMID:24198953

  10. Depositional environments in an alluvial-lacustrine system: molluscan paleoecology and lithofacies relations in upper part of Tongue River Member of Fort Union Formation, Powder River Basin, Wyoming

    SciTech Connect

    Hanley, J.H.; Flores, R.M.

    1983-03-01

    The upper part of the Tongue River Member of the Fort Union Formation (Paleocene) in the northern Powder River basin, Wyoming, contains assemblages of excellently preserved nonmarine mollusks which occur in laterally continuous outcrops of diverse lithologic sequences and sedimentary structures. Three facies are recognized vertically within an alluvial-lacustrine system. The interfluvial lake and lake splay facies is characterized by sequences of coarsening-upward detritus, abundant continuous limestone beds, and few beds of discontinuous coal and continuous carbonaceous shale. Limestones contain two lacustrine mollusk assemblages: a locally reworked assemblage dominated by the bivalve Plesielliptio (two species), and the gastropods Viviparus, Lioplacodes (three species), and Clenchiella; and a quite-water assemblage dominated by sphaeriid bivalves. The interfluvial crevasse splay-crevasse channel facies is characterized by sequences of coarsening-upward detritus and few discontinuous limestone beds, separated vertically by thick, continuous coal and carbonaceous shale beds. This facies includes small crevasse channel sandstones which scour into splay sandstones. Biofabric of lacustrine mollusk assemblages, which are identical in composition (but with dwarfed species of Plesielliptio) to locally reworked lacustrine assemblages of the interfluvial lake and lake splay facies, reflects deterioration of lakes through active infilling by crevasses. The fluvial channel and interchannel facies is typified by thick channel sandstones laterally separated by sequences of coarsening-upward detritus, overbank sediments, and rare limestones. This facies includes thick, continuous coal and carbonaceous shale beds.

  11. Debris flow laterites and bauxites at Naredi, Kutch, western India

    SciTech Connect

    Chitale, D.V.

    1986-05-01

    Reworked laterites and bauxites at Naredi, India, occur as lateritic pebbly mudstone underlain by bauxitic bouldery mudtone and nodular bauxites. The boundary between lateritic pebbly mudstone and bauxitic bouldery mudstone is wavy and sharp, suggesting deposition in two distinct phases. The bouldery bauxites share a diffuse boundary with nodular bauxites. The laterite pebbles float in a yellowish-brown muddy matrix. The boulders and nodules of bauxite are embedded in a massive white clayey matrix. The pebbles and boulders are randomly oriented and are either internally massive or composed of smaller clasts. The occurrence of bauxite boulders over bauxite nodules gives an appearance of inverse bedding. Based on these characteristics, a debris-flow mechanism is proposed for the deposition of laterites and bauxits at Naredi. Deposition occurred as two debris-flow pulses. The bauxites were deposited first, followed by laterites. Smaller clasts are present within the larger clasts, which suggests that the bauxite and laterite clasts had been reworked several times before finally being deposited. The residual, insitu laterites and bauxites capping the hills around Naredi were apparently source rocks for the debris-flow deposits. Deposition is speculated to have occurred during the Miocene-Pliocene.

  12. On intra-supply chain system with an improved distribution plan, multiple sales locations and quality assurance.

    PubMed

    Chiu, Singa Wang; Huang, Chao-Chih; Chiang, Kuo-Wei; Wu, Mei-Fang

    2015-01-01

    Transnational companies, operating in extremely competitive global markets, always seek to lower different operating costs, such as inventory holding costs in their intra- supply chain system. This paper incorporates a cost reducing product distribution policy into an intra-supply chain system with multiple sales locations and quality assurance studied by [Chiu et al., Expert Syst Appl, 40:2669-2676, (2013)]. Under the proposed cost reducing distribution policy, an added initial delivery of end items is distributed to multiple sales locations to meet their demand during the production unit's uptime and rework time. After rework when the remaining production lot goes through quality assurance, n fixed quantity installments of finished items are then transported to sales locations at a fixed time interval. Mathematical modeling and optimization techniques are used to derive closed-form optimal operating policies for the proposed system. Furthermore, the study demonstrates significant savings in stock holding costs for both the production unit and sales locations. Alternative of outsourcing product delivery task to an external distributor is analyzed to assist managerial decision making in potential outsourcing issues in order to facilitate further reduction in operating costs.

  13. Traceurs sédimentaires des variations du niveau marin et de la mousson sud-est asiatique depuis 450 ka en mer de Chine du Sud

    NASA Astrophysics Data System (ADS)

    Boulay, Sébastien; Colin, Christophe; Trentesaux, Alain

    2008-06-01

    In order to reconstruct the past variations of the Southeast Asian monsoon intensity and estimate the sedimentary system reactivity to climatic changes in Southeast Asia over the last 450 kyr, mineralogical and sedimentological analyses have been performed on the terrigenous fraction of the South China Sea sediment. End-member modelling coupled with grain size data discriminates three end-members that determine the nature and intensity of the main sediment transport vectors. Low sea-level stands are characterized by sediment reworking that allows transportation of a coarse end-member (20-40 μm) to the deep-basin. By contrast, the other end-members (4-6 μm; 9-13 μm) are controlled by the shoreline position (sea level) and/or by changes of the rivers capacity transport (monsoon). Finally, aeolian input to the northern margin of the South China Sea can be considered negligible compared to the massive fluvial input and the reworking of the sediments.

  14. Terminal Proterozoic reorganization of biogeochemical cycles

    NASA Technical Reports Server (NTRS)

    Logan, G. A.; Hayes, J. M.; Hieshima, G. B.; Summons, R. E.

    1995-01-01

    The Proterozoic aeon (2,500-540 million years ago) saw episodic increases in atmospheric oxygen content, the evolution of multicellular life and, at its close, an enormous radiation of animal diversity. These profound biological and environmental changes must have been linked, but the underlying mechanisms have been obscure. Here we show that hydrocarbons extracted from Proterozoic sediments in several locations worldwide are derived mainly from bacteria or other heterotrophs rather than from photosynthetic organisms. Biodegradation of algal products in sedimenting matter was therefore unusually complete, indicating that organic material was extensively reworked as it sank slowly through the water column. We propose that a significant proportion of this reworking will have been mediated by sulphate-reducing bacteria, forming sulphide. The production of sulphide and consumption of oxygen near the ocean surface will have inhibited transport of O2 to the deep ocean. We find that preservation of algal-lipid skeletons improves at the beginning of the Cambrian, reflecting the increase in transport by rapidly sinking faecal pellets. We suggest that this rapid removal of organic matter will have increased oxygenation of surface waters, leading to a descent of the O2-sulphide interface to the sea floor and to marked changes in the marine environment, ultimately contributing to the Cambrian radiation.

  15. The geology, mineralogy and paragenesis of the Castrovirreyna lead-zinc-silver deposits, Peru

    USGS Publications Warehouse

    Lewis, Richard Wheatley

    1964-01-01

    The Castrovirreyna mining district lies in the Andean Cordillera of South Central Peru, and has been worked sporadically since its discovery in 1591. Supergene silver ores were first mined. Currently the district produces about 20,000 tons of lead-zinc ore and 5000 tons of silver ore annually. The district is underlain by Tertiary andesitic rocks interbedded with basalts and intruded by small bodies of quartz latite porphyry. The terrane reflects recent glaciation and is largely covered by glacial debris. The ore deposits are steeply dipping veins that strike N. 60? E. to S. 50? E., and average 60 centimeters wide and 300 meters long. The principal veins are grouped around three centers, lying 5 kilometers apart along a line striking N. 55? E. They are, from east to west: San Genaro, Caudalosa, and La Virreyna. A less important set of veins, similarly aligned, lies 2 kilometers to the north. Most of the veins were worked to depths of about 30 meters, the limit of supergene enrichment; but in the larger veins hypogene ores have been worked to depths of over 150 meters. Galena, sphalerite, chalcopyrite, and tetrahedrite are common to all veins, but are most abundant in the westernmost veins at La Virreyna. In the center of the district, around Caudalosa, land sulfantimonides are the commonest ore minerals, and at the eastern end, around San Genaro and Astohuaraca, silver sulfosalts predominate. Supergene enrichment of silver is found at shallow depths in all deposits. Silver at San Genaro, however, was concentrated towards the surface by migration along hypogene physico-chemical gradients in time and space, as vein material was reworked by mineralizing fluids. The pattern of wallrock alteration throughout the district grades from silicification and scricitization adjacent to the veins, through argillization and propylitization, to widespread chloritization farther away. Mineralization can be divided into three stages: 1) Preparatory stage, characterized by

  16. Plant- versus microbial signature in densimetric fractions of mediterranean forest soils: a study by thermochemolysis gas chromatography mass spectrometry

    NASA Astrophysics Data System (ADS)

    Rovira, Pere; Grasset, Laurent

    2015-04-01

    Plant- versus microbial signature in densimetric fractions of mediterranean forest soils: a study by thermochemolysis gas chromatography mass spectrometry The ageing of a given organic substrate decomposing in soil is strongly dependant of its microbial utilization and transformation (reworking) by the soil microflora. How far a given substrate or soil fraction has gone in this evolution is usually measured by means of molecular signatures, ratios between organic compounds which enlighten us about the origin and/or the degree of microbial reworking of a specific group of compounds: lipids, proteins, lignin, carbohydrates, etc. Owing to the biochemical heterogeneity of decomposing substrates it is unlikely that the degree of microbial reworking can be approached with a single signature. Applying a couple of them is much better, but obtaining a wide collection of molecular signatures can be time consuming. Here, instead of applying specific methods to obtain a collection of specific signatures, we apply TMAH-thermochemolysis to obtain a panoramic view of the biochemical composition of a series of densimetric fractions of soils. From the compounds identified after TMAH-thermochemolysis, a collection of indicators was obtained: (a) ratio between short and long-chained linear alkanoic acids; (b) ratio between branched and long-chained linear alkanoic acids; (c) ratio between C16 and total alpha-omega-alkanedioic acids; (d) ratio microbial to plant-derived 1-methoxyalkanes; (e) ratio syringyl to total lignin-derived phenolic compounds; (f) vanillic acid to vanillin ratio; (g) fucose/glucose ratio; and (h) xylose/glucose ratio. From these indicators a single numerical value is distilled, allowing to order a couple of densimetric fractions of soil organic matter according to its degree of microbial reworking. This approach was applied to the comparison of a couple of densimetric fractions of soil organic matter of three organic H horizons from mediterranean forest soils

  17. Influence of bottom trawling on sediment resuspension in the `Grande-Vasière' area (Bay of Biscay, France)

    NASA Astrophysics Data System (ADS)

    Margvelashvili, Nugzar Yu; Herzfeld, Mike; Rizwi, Farhan; Mongin, Mathieu; Baird, Mark E.; Jones, Emlyn; Schaffelke, Britta; King, Edward; Schroeder, Thomas

    2016-08-01

    Sea trials were performed on two zones with different fishing efforts on the continental shelf of the Bay of Biscay (`Grande-Vasière' area of muddy sand) in order to assess particulate matter resuspension and seabed disturbances (i.e., penetration, reworking, grain size changes) induced by different types of trawls. Optical and acoustic measurements made in the water column indicate a significant trawling-induced resuspension mainly due to the scraping action of doors. It manifests as a highly dynamic turbid plume confined near the seabed, where suspended sediment concentrations can reach 200 mg l-1. Concentration levels measured behind an "alternative" configuration (trawls with jumper doors instead of classical doors penetrating the sediment) are significantly lower (around 10-20 mg l-1), which indicates a potential limiting impact regarding the seabed. Grain size analyses of the surficial sediment led to highlight a potential reworking influence of bottom trawling. On the intensively trawled zone, this reworking manifests as an upward coarsening trend in the first 5 cm of the cores. A significant decrease in mud content (30 %) has been also witnessed on this zone between 1967 and 2014, which suggests an influence on the seabed evolution. The geometric analysis of bottom tracks (4-5-cm depth, 20-cm width) observed with a benthic video sledge was used to compute an experimental trawling-induced erosion rate of 0.13 kg m-2. This erosion rate was combined with fishing effort data, in order to estimate trawling-induced erosion fluxes which were then compared to natural erosion fluxes over the Grande-Vasière at monthly, seasonal and annual scales. Winter storms control the annual resuspended load and trawling contribution to annual resuspension is in the order of 1 %. However, results show that trawling resuspension can become dominant during the fishing high season (i.e., until several times the natural one in summer). In addition, the contribution of trawling

  18. First whiffs of atmospheric oxygen triggered onset of crustal gold cycle

    NASA Astrophysics Data System (ADS)

    Frimmel, Hartwig E.; Hennigh, Quinton

    2015-01-01

    Lack of a suitable gold source has long been regarded as a major argument against a palaeoplacer model for the exceptionally well-endowed Witwatersrand gold province. By comparing worldwide Witwatersrand-type deposits/occurrences, ranging in age from 3.1 to 1.8 Ga, we propose that the primary concentration of gold in the continental crust resulted from atmospheric and biological evolution in the Mesoarchaean. A high Au flux off the Archaean land surface (orders of magnitude greater than today's) was a consequence of the chemistry of the Mesoarchaean atmosphere and hydrosphere. When early life gradually changed from anaerobic anoxygenic to oxygenic photosynthesizers at around 3.0 Ga, the first `whiffs' of free oxygen produced by photosynthesis under an overall reducing atmosphere provided the ideal trap for Au dissolved in the huge reservoir in meteoric and shallow sea water. Oxidative precipitation of gold on the surface of the O2-producing microbes, probably cyanobacteria, could fix huge amounts of gold over large areas. Some of this microbially mediated gold is still preserved in thin kerogen layers ("carbon seams") that typically developed on erosional unconformities, scour surfaces and bedding planes in near-shore environments at around 2.9 Ga. This gold provided the principal source for the very rich placer deposits that formed by the subsequent sedimentary reworking of the delicate microbial mats on aeolian deflation surfaces, into fluvial channels and delta deposits, represented by Meso- to Neoarchaean auriferous conglomerates. Tectonic reworking of these first gold-rich sediments by orogenic processes explains the temporal peak of orogenic-type gold formation at around 2.7 to 2.4 Ga. With time, the strongly gold-enriched Archaean sediments became progressively eroded, covered or tectonically reworked, and their role as potential source of younger placer deposits diminished. This explains why Witwatersrand-type deposits younger than 2.4 Ga are rare and far

  19. Contrasting crustal evolution processes in the Dharwar craton

    NASA Astrophysics Data System (ADS)

    Lancaster, Penelope J.; Dey, Sukanta; Storey, Craig D.; Mitra, Anirban; Bhunia, Rakesh K.

    2015-04-01

    Archaean cratons provide a critical window into early Earth dynamics, preserving a record of crustal evolution processes that include the start of 'modern' plate tectonics and the development of supercontinents. However, these same processes can also destroy or rework substantial volumes of crust, and the oldest extant Archaean terrane is only ~3.9 Ga. Where Archaean rocks are exposed, bulk techniques such as Pb and Nd isotopes can provide considerable information about continental formation, but these may have been altered by later metamorphic events. Another method is to examine sedimentary units, which can preserve fragments of the crust that are no longer exposed at the Earth's surface. Resistant detrital minerals such as zircon have particular use in these studies, as they incorporate a range of isotopic and geochemical tracers and can survive multiple crystallisation and/or sedimentary events. In this manner, a more complete record of a craton's evolution may be obtained, with the benefit of contributions from contrasting isotopic systems. The Dharwar craton of southern India is one such Archaean block, comprising >2.7 Ga trondjhemite-tonalite-granodiorite (TTG) gneisses, volcano-sedimentary belts (>3.0 and 2.9-2.6 Ga) and 2.7-2.5 Ga calc-alkaline to potassic granitoids. These rocks preserve evidence for several cycles of supracrustal formation, deformation, metamorphism and granitic activity during the Precambrian. New in situ U-Pb-Hf analyses of detrital zircons from across the craton indicate significant juvenile crustal extraction events at ~3.3 and 2.7 Ga, and continuous extraction from 3.7-3.3 Ga. Reworking in the older western block at ~3.0 Ga marks the onset of cratonisation, most likely due to 'modern' plate tectonic processes, while reworking in both the western and younger eastern block at 2.55-2.50 Ga indicates accretion of the two terranes and final cratonisation much later than in most other Archaean terranes (~2.7 Ga). Different patterns of

  20. Pb isotopic variability in the modern-Pleistocene Indus River system measured by ion microprobe in detrital K-feldspar grains

    NASA Astrophysics Data System (ADS)

    Alizai, Anwar; Clift, Peter D.; Giosan, Liviu; VanLaningham, Sam; Hinton, Richard; Tabrez, Ali R.; Danish, Muhammad; Edinburgh Ion Microprobe Facility (EIMF)

    2011-09-01

    The western Himalaya, Karakoram and Tibet are known to be heterogeneous with regard to Pb isotope compositions in K-feldspars, which allows this system to be used as a sediment provenance tool. We used secondary ion mass spectrometry to measure the isotopic character of silt and sand-sized grains from the modern Sutlej and Chenab Rivers, together with Thar Desert sands, in order to constrain their origin. The rivers show a clear Himalayan provenance, contrasting with grains from the Indus Suture Zone, but with overlap to known Karakoram compositions. The desert dunes commonly show 207Pb/ 204Pb and 206Pb/ 204Pb values that are much higher than those seen in the rivers, most consistent with erosion from Nanga Parbat. This implies at least some origin from the trunk Indus, probably reworked by summer monsoon winds from the SW, a hypothesis supported by bulk Nd and U-Pb zircon dating. Further data collected from Holocene and Pleistocene sands shows that filled and abandoned channels on the western edge of the Thar Desert were sourced from Himalayan rivers before and at 6-8 ka, but that after that time the proportion of high isotopic ratio grains rose, indicating increased contribution from the Thar Desert dunes prior to ˜4.5 ka when flow ceased entirely. This may be linked to climatic drying, northward expansion of the Thar Desert, or changes in drainage style including regional capture, channel abandonment, or active local Thar tributaries. Our data further show a Himalayan river channel east of the present Indus, close to the delta, in the Nara River valley during the middle Holocene. While this cannot be distinguished from the Indus it is not heavily contaminated by reworking from the desert. The Pb system shows some use as a provenance tool, but is not effective at demonstrating whether these Nara sediments represent a Ghaggar-Hakra stream independent from the Indus. Our study highlights an important role for eolian reworking of floodplain sediments in arid rivers

  1. Ice marginal dynamics during surge activity, Kuannersuit Glacier, Disko Island, West Greenland

    NASA Astrophysics Data System (ADS)

    Roberts, David H.; Yde, Jacob C.; Knudsen, N. Tvis; Long, Antony J.; Lloyd, Jerry M.

    2009-02-01

    The Kuannersuit Glacier surged 11 km between 1995 and 1998. The surge resulted in the formation of an ice cored thrust moraine complex constructed by subglacial and proglacial glaciotectonic processes. Four main thrust zones are evident in the glacier snout area with phases of compressional folding and thrusting followed by hydrofracture in response to the build-up of compressional stresses and the aquicludal nature of submarginal permafrost and naled. Various types of stratified debris-rich ice facies occur within the marginal zone: The first (Facies I) comprises laterally continuous strata of ice with sorted sediment accumulations, and is reworked and thrust naled ice. The second is laterally discontinuous stratified debris-rich ice with distinct tectonic structures, and is derived through subglacial extensional deformation and localised regelation (Facies II), whilst the third type is characterised by reworked and brecciated ice associated with the reworking and entrainment of meteoric ice (Facies III). Hydrofracture dykes and sills (Facies IV) cross-cut the marginal ice cored thrust moraines, with their sub-vertically frozen internal contact boundaries and sedimentary structures, suggesting supercooling operated as high-pressure evacuation of water occurred during thrusting, but this is not related to the formation of basal stratified debris-rich ice. Linear distributions of sorted fines transverse to ice flow, and small stratified sediment ridges that vertically cross-cut the ice surface up-ice of the thrust zone relate to sediment migration along crevasse traces and fluvial infilling of crevasses. From a palaeoglaciological viewpoint, marginal glacier tectonics, ice sediment content and sediment delivery mechanisms combine to control the development of this polythermal surge valley landsystem. The bulldozing of proglacial sediments and the folding and thrusting of naled leads to the initial development of the outer zone of the moraine complex. This becomes

  2. Deep-seated landslides and seismic triggering along major transcurrent faults in central Asia and California.

    NASA Astrophysics Data System (ADS)

    Rust, Derek; Korjenkov, Andrey; Bobrovskii, Alexander; Mamyrov, Ernes

    2010-05-01

    The Tien Shan mountains of central Asia, the northernmost expression of India-Eurasia collision, are characterised by active deformation (GPS measured contraction rates of ~20 mm a-1), rapid uplift and steep slopes prone to landsliding. In addition to seismogenic structures associated with contraction, the mountain belt is bisected by the Talas-Fergana fault, a poorly-known, historically aseismic, 700-km-long dextral strike-slip structure displaying active faulting and landslide features similar to those along the San Andreas fault in the Transverse Ranges of southern California. In both cases uplift along fault traces making up the fault zones has produced a deep central trough occupied by landslide and reworked landslide deposits, bordered by mountain ridges dominated by high to medium grade metamorphic bedrock and acting as landslide source areas. Moreover, palaeoseismic evidence suggests both fault zones may be regarded as seismic gaps characterised by relatively infrequent large-magnitude earthquakes. The numerous deep-seated landslides along both fault zones record a long history of landsliding based on: 1) radiocarbon dating; 2) sequences of lacustrine deposits containing apparent seismites and formed in landslide-dammed lakes now breached and drained; 3) recorded offsets and entrenchment of drainage features and deposits, associated with a characteristic cycle of fluvial reworking of landslide masses; 4) perched gravels preserved high on central trough walls and interpreted as related to reworking of landslide deposits; 5) degree of erosional and depositional degradation, including a time-series of landslide mass - lacustrine deposit assemblages. Together, these features suggest a landslide history characterised by large-volume failures, a pattern thought to mirror that of seismic strain release along these apparently locked fault systems. It seems likely that deep-seated landslides are effectively only triggered by major faulting events in these settings

  3. Late Pleistocene Terraces in River Valleys of the Central Russian Plain: Morphology, Structure and History of Development

    NASA Astrophysics Data System (ADS)

    Matlakhova, Ekaterina; Panin, Andrey

    2014-05-01

    Morphology and sedimentary composition of low terraces of the Seim (the middle Dnieper catchment) and Khoper (the middle Don catchment) rivers were studied in the field (DGPS topographic profiling, hand and mechanical coring, examination of natural exposures) and in laboratory (grain size analysis, spore-pollen composition, 14C and OSL dating, microscopic study of quartz grains). Archaeological data have also been taken into account. It was found that Late Pleistocene river terraces were subject to complex reworking after the alluvial sedimentation had finished. Terraces may therefore contain sediments of different origin and terrace levels may vary according to the post-alluvial reworking. To establish terrace sedimentation mechanisms we supplemented lithological data collected in the field with quartz grains morphoscopy technique - microscopic study of quartz grains surfaces. The results exhibit wide participation of aeolian and slope wash sediments in terrace deposits, deep aeolian reworking of terrace alluvium during LGM that could be possible due to ground water lowering because of deep pre-LGM incision of rivers. The main difficulty in interpretation of morphoscopic results is that aeolian signals are sometimes not clear due to short duration of wind action over alluvial sands. River incision was detected within the interval since 50-60 to 25-30 ka BP (cal). High runoff increase is proposed as the reason of this incision, which is illustrated by formation of "big meanders" (macromeanders) in river valleys. There were probably several time spans of high runoff divided by low runoff intervals. By the time of LGM rivers had already been incised down to the modern river levels or deeper. The cryoaridic LGM time (20-23 ka BP cal) makes the most pronounced low runoff interval. After LGM, the last high runoff epoch started, which is dated to 13-18(19) ka BP (cal). Numerous now relict macromeanders were formed in river valleys at that time and considerable portions

  4. Radiocarbon dating of marine material: mollusc versus foraminifera ages

    NASA Astrophysics Data System (ADS)

    Callard, L.; Long, A. J.; Plets, R. M.; Cooper, A.; Belknap, D. F.; Edwards, R.; Jackson, D.; Kelley, J. T.; Long, D.; Milne, G. A.; Monteys, X.; Quinn, R.

    2013-12-01

    A key challenge in reconstructing Quaternary environmental change from marine archives is developing a robust chronology. During the last ~50k a-1, radiocarbon dating is the mainstay for many studies. Often investigators are restricted in the material that is available for dating, with studies relying on AMS dating of either mono-specific or mixed assemblages of foraminifera. In some instances, marine molluscs (broken or whole, articulated or disarticulated) may also be present and can provide an alternative or complementary dating target. Previous radiocarbon dating of paired foraminiferal and marine molluscan samples from the Kattegat (Denmark) revealed significant age offsets between these materials, inferred to reflect greater reworking of foraminifera compared to the marine molluscs (Heier-Nielsen et al., 1995). Here we present the results of a comparable study from the Irish Sea Basin, which forms part of a wider investigation into the evidence for the Late Glacial sea-level minima at offshore sites from around Britain and Ireland. We have collected and AMS 14C-dated twelve paired samples of foraminifera and marine shells. The results shows a systematic age offset with the monospecific foraminifera samples consistently giving older ages than their shell counterparts. This offset increases with sample age, reaching a maximum offset of 3000 years in the oldest sample (~ 13 ka cal a BP). These results are consistent with the observations of Heier-Nielsen et al. (1995), and we hypothesize that foraminifera may be more susceptible to reworking from older deposits because of their lower effective density than the shell samples. However, foraminifera size and shape may also be contributing factors. These findings are potentially significant for studies that develop chronologies based on radiocarbon dating of foraminifera alone, since the resulting dates may over-estimate sample age by several thousand years. We conclude by outlining an experimental design that seeks

  5. Quantification of sediment budgets at an arctic delta

    NASA Astrophysics Data System (ADS)

    Kroon, A.; Bendixen, M.; Sigsgaard, C.

    2012-12-01

    The impact of ice and snow and freezing temperatures make arctic polar coastal environments quite unique and different from other coastal environments for instance in temperate zones or in tropic areas. The coastal processes and the morphologic evolution of landforms in these areas are strongly influenced by common factors such as cold temperatures, (dis)continuous or sporadic permafrost, and the presence of sea ice cover. Most of these factors have a strong seasonality and the impact of classic coastal processes by waves and tides are often limited to the summer and early fall. Global climate changes induce a lot of changes along the arctic coasts. Sea-levels are rising due to an increased fresh water flux from the glaciers and land ice masses. At the same time, the ice coverage of the coastal waters decreases and the open water periods in summer extend. This might cause extra wave activity with higher erosion rates along many of the shorelines. Many fjords and open coastal stretches in North-East Greenland have deltas. The sources for the sediments for these deltas are located in the drainage basins of rivers that are fed by melting glaciers. These rivers drain pro-glacial and fluvial valleys and may also deliver additional sediment by eroding glacial and peri-glacial deposits in the present coastal plain. Minor sources of sediment transport towards the delta come from reworking of sediments on the delta slope, through lateral transport from the adjacent shores, and through stranded sediment-loaded ice out of the fjord. Losses of sediments occur through further fluvial sediment transport over the delta towards the fjord, or by reworking of delta fringes by coastal processes due to ice, waves and tides. Sandy spits and small barriers often fringe the shoreline of a delta. These features are typically formed and active in the ice-free periods when coastal processes by waves and drifting ice rework the delta front and adjacent coastal cliffs. In this presentation

  6. Effects of nourishment on the form and function of an estuarine beach

    USGS Publications Warehouse

    Jackson, N.L.; Nordstrom, K.F.; Saini, S.; Smith, D.R.

    2010-01-01

    Beach nourishment programs in estuaries can enhance shore protection, but they decrease habitat suitability by creating higher berms and wider backshores than would occur under natural conditions. Use of sediment sources from outside the area can result in sedimentary characteristics that differ from native sediments on the surface and at depth, altering conditions for both aeolian transport to dunes and interstitial fauna. Field data were gathered on an estuarine beach to determine differences in beach profile change, depth of sediment reworking, and potential for aeolian transport due to nourishment. Data were gathered over a 20-month period 6 months prior to nourishment, 3 days after nourishment, 6 months after nourishment, and 14 months after nourishment when the beach was mechanically graded to eliminate a vertical scarp in the foreshore. The nourishment consisted of 87,900m3 of sediment emplaced to create a 1.34-km-long, 30-m-wide berm 2.3m above mean tide level. Seven percent of the fill was removed from the profile within 6 months after nourishment, accompanied by 7m in horizontal retreat of the artificial berm. The fill on the backshore remained above the zone of wave influence over a winter storm season and was separated from the active foreshore by the scarp. Nourished sediments on the intertidal foreshore were significantly different from native sediments to a depth of 0.20m below the surface. A lag surface of coarse sediment formed by deflation on the backshore, resulting in a rate of aeolian transport <2% of the rate on the wave-reworked foreshore.Nourishing a beach to a level higher than would be created by natural processes can create a profile that compartmentalizes and restricts transport of sediment and movement of fauna between the foreshore and backshore. Mechanical grading can eliminate the scarp, allow for faunal interaction, and reestablish wave reworking of the backshore that will facilitate aeolian transport. Using an initial design to

  7. Données nouvelles sur la stratigraphie des terrains carbonifères de la Meseta orientale marocaine (boutonnières de Debdou, Mekam et Jerada)

    NASA Astrophysics Data System (ADS)

    Berkhli, M.; Paicheler, J.-C.; Vachard, D.

    1993-04-01

    Lower Carboniferous deposits from Eastern Morocco are located in small depressions within a more or less mountainous Jurassic area. Sections from Tafechna, Flouch and Oued Korima (Debdou and Mekam basins, Eastern Morocco) are accurately described. Owing to detailed field examination, misinterpreted lithological aspects are corrected, i.e. volcano-sedimentary deposits are very important and carbonate deposits almost absent. Debdou yields alternations of blackish shales and sandstones with intercalations of tuffites overlain by volcanoclastic or calcareous sandstones, whose turbiditic origin is indicated by graded-bedding and scour casts, and also by reworked oolites and Foraminifera. Mekam shows slumped limestones and conglomerates with basement pebbles, cemented by carbonates, and with some reworked Foraminifera, overlain by alternations of greenish shales, tuffaceous siltstones and ashes. The stratigraphical background of these sections is also explicited or modified. Existence of Tournaisian beds is excluded. Assemblages of Foraminifera are always uppermost Visean or lowermost Serpukhovian in age. New palynological data agree with this fact; so do former Goniatites datings. These series are paralleled with the well-known series of the area: Jerada, Tazekka, “Northern Olistostrome” (including Jorf Ouazzene, Zekkara and Tannecherfi outcrops). These comparisons concern at the same time the biostratigraphy, the environments, the volcanism, etc. The Uppermost Visean We stratigraphy of Jerada is established as well as the Serpukhovian E1-E2 stratigraphy from Tazekka and Northern Olistostrome, where V3c remains are reworked. Importance of Brigantian (V3c) substage is emphasized at the regional scale, it is the maximal transgression time upon the Devonian epimetamorphic substrate; transgression probably begun in the Upper Asbian (V3bγ). Knowledge of Serpukhovian (= Namurian A) within the various basins needs new investigations. This stage is still characterized

  8. Fluvial Response to Hydrologic Variability in the Pelly River, Yukon Territory, Canada

    NASA Astrophysics Data System (ADS)

    McKenney, R.; Peterson, K.; Ramage, J. M.; Thorson, B.; Hanna, W.; Kortlever, B.; Apgar, J. D.

    2006-12-01

    The potential impacts of climate changes on fluvial systems in northern latitudes are difficult to predict due to the complex interactions expected among climate change, hydrology, and fluvial processes. Thus, cataloging the response of fluvial processes to modern hydrologic variability is needed to assess current and future impacts of hydrologic change on northern watersheds. In this study, dendrochronology, gauge data, and pedology are being used to study floodplain reworking in a section of the Pelly River basin, Yukon Territory, Canada. The hydrology of the Pelly River system is snow-melt dominated, with little to no glacial contribution. The Pelly River has been gauged at 4 sites for periods of 9 years to 55 years since 1951; of these sites, the gages at Pelly Crossing (09BC001) and below Vangorda Creek (09BC004) are still active. The gauges measure discharge for drainage areas ranging from 5,020 km2 below Fortin Creek (09BA002), to 49,000 km2 on the Pelly River at Pelly Crossing. Mean bed elevation changes calculated from gauge data vary from less than 0.2 m below Fortin Creek to 2.1m below Vangorda Creek (drainage area 22,100km2). These mean bed elevation changes show a variable relation to peak discharge. Within the section of the Pelly River between Ross River and Faro, dendrochronology of studied bars indicates that active gravel bar surfaces are less than 30 years old. Adjacent surfaces which slope continuously to the current active flood plain, however, support spruce forests at least 100 years old. Near Ross River, an ash interpreted to be the White River ash (deposited approximately 1200 years ago) crops out at the surface of a terrace several meters above the current active bar surface and approximately half a meter below the surface of a lower terrace. Soil development and surface morphology support the hypothesis that the lower terrace surface is younger than the higher terrace and was buried by fluvial aggradation after ash deposition

  9. Characterization of the K-T and Chicxulub Ejecta Layers along the Brazos River, Texas: Correlation with NE Mexico and Yucatan.

    NASA Astrophysics Data System (ADS)

    Thierry, A.; Gerta, K.

    2005-05-01

    We report the results of preliminary investigations of four K-T boundary sections, which are located in small tributaries (Cottonmouth and Darting Minnow creeks) of the Brazos River. The study is based on high-resolution sampling, sedimentological observations, biostratigraphy, bulk rock and clay mineralogy, geochemistry and granulometry. The Cottonmouth Creek exposure is characterized by Late Maastrichtian dark grey fossiliferous claystone, interrupted by laterally variable channel fill storm deposits, which previously have been erroneously interpreted as impact tsunami deposits. These deposits consist of a basal shell hash (10cm), followed by glauconitic sand with altered impact spherules (10cm), laminated sandstones, and 4 to 5 hummocky cross-bedded sandstone layers separated by burrowed erosion surfaces that mark repeated colonization of the ocean floor between storm events. Above and below these storm events are dark grey fossiliferous claystones of the late Maastrichtian zone CF1, which spans the last 300,000 years of the Cretaceous. The K-T boundary is 40 cm above the storm deposits. Granulometric analyses of this interval reveal no size grading due to suspension settling from storm or tsunami waves, but rather indicate normal hemipelagic sedimentation. The Chicxulub spherule ejecta in the glauconitic sand near the base of the storm beds is reworked from an older original ejecta layer, as indicated by abundant reworked fossil shells. This is similar to the reworked spherule layers at the base of the siliclastic deposits throughout NE Mexico, where the original layer is within marls up to 5 m below (base of CF1) and predating the K-T by 300,000 years. We may have discovered the original ejecta layer in Cottonmouth Creek 60 cm below the basal unconformity of the storm beds and within claystones near the base of zone CF1. This layer consists of a prominent 3-4 cm thick yellow clay of pure and well-crystallized smectite (Cheto Mg-smectite) that possibly

  10. Geochronology of the Baltica crust in the Western Gneiss Region, Norway: Palaeoproterozoic augen gneisses, Sveconorwegian zircon neocrystallization and Caledonian zircon deformation

    NASA Astrophysics Data System (ADS)

    Røhr, Torkil S.; Bingen, Bernard; Robinson, Peter; Reddy, Steven M.

    2013-04-01

    The Western Gneiss Region, Western Norway, is dominated by Palaeoproterozoic to Mesoproterozoic felsic crust of Baltica ancestry (Baltican Basement), partly subducted to high- and ultrahigh-pressure (HP-UHP) conditions during the Caledonian (Scandian) orogeny between 415 and 395 Ma. The dominant felsic gneisses, in contrast with mafic rocks, carry little evidence for the HP-UHP history, but were affected by amphibolite-facies reworking during exhumation. LA-ICPMS and SIMS zircon U-Pb data were collected in augen orthogneiss samples to constrain the magmatic and metamorphic geochronology in this crust. Five samples from the eclogite-bearing HP-UHP basement near Molde yield intrusion ages ranging from 1644 +/-6 to 1594 +/-10 Ma. Two samples of the structurally underlying eclogite-free basement yield ages of 1685 ±18 and 1644 +/-13 Ma, and a sample from the infolded Middle Allochthon Risberget Nappe yields an equivalent age of 1676 +/-18 Ma. Two samples of the eclogite-bearing basement contain low Th/U neocrystallized zircon with an age of 950 +/-26 Ma. This zircon provides the northernmost direct evidence for at least amphibolite-facies Sveconorwegian metamorphism in unquestionable Baltican crust, close to the known "Sveconorwegian boundary" in the Western Gneiss Region. The Western Gneiss Region characterized by 1686-1594 Ma magmatism, the Eastern Segment of the Sveconorwegian Orogen characterized by 1795-1640 Ma magmatism, and the Idefjorden terrane hosting the type Gothian active margin magmatism dated between 1659 and 1520 Ma, probably represent three distinct Proterozoic growth zones of Baltica into which Sveconorwegian reworking propagated. Samples of the eclogite-bearing basement lack Scandian neocrystallization of zircon, but show partial recrystallization of zircon. Paired CL and EBSD images indicate that zircon crystals underwent crystal-plastic deformation during the Scandian subduction-exhumation cycle. They illustrate a relationship between crystal

  11. Neoarchean-Early Paleoproterozoic and Early Neoproterozoic arc magmatism in the Lützow-Holm Complex, East Antarctica: Insights from petrology, geochemistry, zircon U-Pb geochronology and Lu-Hf isotopes

    NASA Astrophysics Data System (ADS)

    Tsunogae, Toshiaki; Yang, Qiong-Yan; Santosh, M.

    2016-10-01

    The Lützow-Holm Complex (LHC) of East Antarctica forms part of the Neoproterozoic-Cambrian high-grade metamorphic segment of the East African-Antarctic Orogen. Here we present new petrological, geochemical, and zircon U-Pb and Lu-Hf isotopic data for meta-igneous rocks including charnockite, felsic gneiss, metagabbro, and mafic granulite from the LHC and evaluate the Neoarchean to Early Paleoproterozoic (ca. 2.5 Ga) and Early Neoproterozoic (ca. 1.0 Ga) arc magmatic events. The trace element geochemical signatures reveal a volcanic arc affinity for the charnockites from Sudare Rocks and Vesleknausen and felsic gneiss from Rundvågshetta, suggesting that the protoliths of these rocks were derived from felsic arc magmas. In contrast, metagabbros from Skallevikshalsen and Austhovde, occurring as boudins in metasediments, show non-arc signatures (within-plate basalt or mid-oceanic ridge basalt). The upper intercept ages of magmatic zircons in charnockite plotted on concordia diagrams yielded 2508 ± 14 Ma (Sudare Rocks) and 2490 ± 18 Ma (Vesleknausen), clearly suggesting a Neoarchean to Early Paleoproterozoic arc magmatic event. A subsequent thermal event during Early Neoproterozoic traced by 206Pb/238U age of oscillatory-zoned core of zircon in mafic granulite from Langhovde (973 ± 10 Ma) is consistent with a similar Early Neoproterozoic magmatic event reported from the LHC, suggesting a second stage of arc magmatism. The timing of peak metamorphism has been inferred from 206Pb/238U mean ages of structureless zircons in metagabbros from Skallevikshalsen and Austhovde, mafic granulite from Langhovde, and felsic gneiss from Rundvågshetta in the range of 551 ± 5.4 to 584 ± 5.0 Ma. Zircon Lu-Hf data of Neoarchean charnockites from Sudare Rocks and Vesleknausen indicate that the protolith magma was sourced from Paleo- to Neoarchean juvenile components mixed with reworked ancient crustal materials. Protolith magmatic rock of the felsic gneiss from Rundvågshetta might

  12. Laboratory Analyses Of Basaltic Dunes In The Ka'u Desert Of Hawaii And Implications For Understanding Dark Dunes On Mars

    NASA Astrophysics Data System (ADS)

    Tirsch, D.; Craddock, R. A.; Nanson, G.; Tooth, S.; Langhans, M.

    2010-12-01

    Dark dunes are the dominant aeolian bedforms on Mars and consist of ancient volcanic ashes and reworked basaltic lavas. Basaltic dunes are rare on Earth and only occur in limited areas, such Hawaii. Because the Hawaiian dunes are composed of reworked basaltic sediments transported by eolian processes, they are a promising subject matter of analogy studies. Samples of dark dune sands, ash, and tephra collected in Hawaii's Ka'u Desert were collected during field trips in summer 2009 and 2010. They were analyzed by a variety of laboratory methods, including spectral, microscope, and microprobe investigations, in order examine their detailed mineralogical composition and constitution. We then compared the results to the eolian dunes on Mars. Sand samples were collected from three different dark dunes in Ka'u Desert: a large, vegetated, parabolic dune, a falling dune, and a large climbing dune. Tephra from the phreatic eruption that began in March 2008 was collected over a two year period using sample collectors placed at different locations downwind of Kilauea caldera. Analyses of these samples allow us to determining the initial composition, grain shape, and grain size of probable source materials. The visible and near-infrared reflectance spectra of the samples were acquired for the 0.5 to 2.5µm range. The overall spectral shape of the dune sand samples indicates a mineralogical correlation between Martian and terrestrial dune sands indicating a similar volcanic origin of the sediments. The spectra of the Hawaiian samples reveal some aqueous alteration, which is probably related to hydrated amorphous silica. Initial microscope and microprobe analyses reveal a high amount of volcanic glass and rock fragments in the samples, followed by olivine, feldspars, and pyroxene. Vitric particles that dominate the majority of the dune samples indicate in situ material accumulation following larger phreatic eruptions. The top coarse-grained layer of the climbing dune comprises a

  13. Influence of bottom trawling on sediment resuspension in the `Grande-Vasière' area (Bay of Biscay, France)

    NASA Astrophysics Data System (ADS)

    Mengual, Baptiste; Cayocca, Florence; Le Hir, Pierre; Draye, Robin; Laffargue, Pascal; Vincent, Benoit; Garlan, Thierry

    2016-09-01

    Sea trials were performed on two zones with different fishing efforts on the continental shelf of the Bay of Biscay (`Grande-Vasière' area of muddy sand) in order to assess particulate matter resuspension and seabed disturbances (i.e., penetration, reworking, grain size changes) induced by different types of trawls. Optical and acoustic measurements made in the water column indicate a significant trawling-induced resuspension mainly due to the scraping action of doors. It manifests as a highly dynamic turbid plume confined near the seabed, where suspended sediment concentrations can reach 200 mg l-1. Concentration levels measured behind an "alternative" configuration (trawls with jumper doors instead of classical doors penetrating the sediment) are significantly lower (around 10-20 mg l-1), which indicates a potential limiting impact regarding the seabed. Grain size analyses of the surficial sediment led to highlight a potential reworking influence of bottom trawling. On the intensively trawled zone, this reworking manifests as an upward coarsening trend in the first 5 cm of the cores. A significant decrease in mud content (30 %) has been also witnessed on this zone between 1967 and 2014, which suggests an influence on the seabed evolution. The geometric analysis of bottom tracks (4-5-cm depth, 20-cm width) observed with a benthic video sledge was used to compute an experimental trawling-induced erosion rate of 0.13 kg m-2. This erosion rate was combined with fishing effort data, in order to estimate trawling-induced erosion fluxes which were then compared to natural erosion fluxes over the Grande-Vasière at monthly, seasonal and annual scales. Winter storms control the annual resuspended load and trawling contribution to annual resuspension is in the order of 1 %. However, results show that trawling resuspension can become dominant during the fishing high season (i.e., until several times the natural one in summer). In addition, the contribution of trawling

  14. The Geology and Volcanic Evolution of the Hjorliefshofthi Outlier, Iceland: A 3D exposure of a Surtseyan Volcano?

    NASA Astrophysics Data System (ADS)

    Watton, T. J.; Thordarson, T.; Jerram, D. A.; Brown, R. J.

    2012-12-01

    Hjörleifshöfthi is a small (~4 km2) isolated Quaternary volcanic outlier in southern Iceland that provides an excellent exposure of a Surtseyan volcano. It sits in a large sandur plain formed by glacier melt water outwash from late Holocene subglacial activity at Katla volcano: Aggradation of outwash sediments turned Hjörleifshöfthi from an island into part of the mainland. Detailed field mapping, logging and sampling of Hjörleifshöfthi has allowed the recognition of thirteen lithofacies and six depositional and eruptive phases. Phase one was the pre-emergent phase of Surtseyan volcanism and is characterised by hyaloclastite deposition. Large syn-sedimentary listric faults dissect phase 1 deposits and are inferred to result from edifice collapse. In Phase 1 faulting may have acted as pathways for magma intrusion in the shallow subsurface. Reactivation of faults continued until phase 4. Phase 2 involved the continued emplacement of hyaloclastite material, reworking (due to shoaling) and the emplacement of subaerial and subaqueous lava flows, fine grained vesicular tephra and basaltic spatter. Phase 2 lava flows thicken northwards suggesting ponding in a large dammed crater separated from the sea. However, in the south, abundant hyaloclastite material was still been generated. Hjörleifshöfthi now is what remains of a small slice of a earlier emergent island. Subsidence resulted in the deposition of a shallow marine succession of reworked volcaniclastic material (Phase 3). A distinct red fine-grained, lithic-rich (with partially quenched fragments) ignimbrite succession fills topographic lows (Phase 4). The affinity of the ignimbrite succession to Hjörleifshöfthi is unknown. Phase 5 consisted of a localized lava emplacement and marine reworking of volcaniclastic material along the southern margin. Phase 5 basalt lavas flowed down into the crater and buried the marine volcaniclastic sediments. Thin (1-4 m) accretionary lapilli-bearing tuff layers (Phase 6

  15. Compositional Grading in an Impact-produced Spherule Bed, Barberton Greenstone Belt, South Africa: A Key to Condensation History of Rock Vapor Clouds

    NASA Technical Reports Server (NTRS)

    Krull, A. E.; Lowe, D. R.; Byerly, G. R.

    2003-01-01

    The chemical and physical processes by which spherules form during the condensation of impact-produced rock vapor clouds are poorly understood. Although efforts have been made to model the processes of spherule formation, there is presently a paucity of field data to constrain the resulting theoretical models. The present study examines the vertical compositional variability in a single early Archean spherule bed in the Barberton Greenstone Belt (BGB), South Africa, in order to better identify the process by which impact vapor clouds condense and spherules form and accumulate. The BGB spherule beds are suitable for this type of study because of their great thickness, often exceeding 25cm of pure spherules, due to the massive sizes of the impactors. Two main problems complicate analysis of vertical compositional variability of graded spherule beds: (1) differential settling of particles in both the vapor and water column due to density and size differences and (2) turbulence within the vapor cloud. The present study compares sections of spherule bed S3 from four different depositional environments in the Barberton Greenstone Belt: (1) The Sheba Mine section (SAF-381) was deposited under fairly low energy conditions in deep water, providing a nice fallout sequence, and also has abundant Ni-rich spinels; (2) Jay's Chert section (SAF-380) was deposited in subaerial to shallow-water conditions with extensive post-depositional reworking by currents. The spherules also have preserved spinels; (3) the Loop Road section (loc. SAF-295; samp. KSA-7) was moderately reworked and has only rare preservation of spinels; and (4) the shallow-water Barite Syncline section (loc. SAF-206; samp KSA-1) has few to no spinels preserved and is not reworked. Although all of the spherule beds have been altered by silica diagenesis and K-metasomatism, most of the compositional differences between these sections appear to reflect their diagenetic histories, possibly related to their differing

  16. Landscape by Moonlight: Peter Paul Rubens and Astronomy

    NASA Astrophysics Data System (ADS)

    Mendillo, M.

    2016-01-01

    In the last years of his life, Rubens (1577-1640) lived happily with his wife and children on his Het Steen estate. During this period he worked and reworked a painting that had special meaning to him—Landscape by Moonlight (1635-40), now at the Courtauld Gallery in London. After a highly successful career painting religious and secular portraits, allegories, and occasional landscapes, Rubens put an extraordinary amount of effort into this final landscape. He was well known as a person who would commit to memory ideas and themes that he would use in future works. This paper reviews Rubens' attention to the visualization of nature, his personal connections to Elsheimer, Galileo, and Peiresc, and explores his possible depiction of constellations recalled from memory and placed within the cloudy skies in his Landscape by Moonlight.

  17. Sediment delivery by ungaged tributaries of the Colorado River in Grand Canyon, Arizona

    USGS Publications Warehouse

    Webb, Robert H.; Griffiths, Peter G.; Melis, Theodre S.; Hartley, Daniel R.

    2000-01-01

    Sediment input to the Colorado River in Grand Canyon, Arizona, is a valuable resource required to sustain both terrestrial and aquatic ecosystems. A total of 768 ungaged tributaries deliver sediment to the river between Glen Canyon Dam and the Grand Wash Cliffs (river miles -15 to 276). The 32 tributaries between the dam and Lee's Ferry produce only streamflow floods, whereas 736 tributaries in Grand Canyon produce streamflow floods and debris flows. We used three techniques to estimate annual streamflow sediment yield from ungaged tributaries to the Colorado River. For the Glen Canyon and Marble Canyon reaches (river miles -15 to 61.5), respectively, these techniques indicate that 0.065.106 and 0.610.106 Mg/yr (0.68.106 Mg/yr of total sediment) enters the river. This amount is 20 percent of the sediment yield of the Paria River, the only gaged tributary in this reach and a major sediment contributor to the Colorado River. The amount of sand delivered ranges from 0.10.106 to 0.51.106 Mg/yr, depending on the sand content of streamflow sediment. Sand delivered in Glen Canyon is notably coarser (D50 = 0.24 mm) than sand in other reaches (D50 = 0.15 mm). A relation is given for possible variation of this sediment delivery with climate. Debris flows transport poorly-sorted sediment onto debris fans in the Colorado River. In the pre-dam era, debris fans were completely reworked during Colorado River floods, liberating all fine-grained sediment to the river; in the post-dam river on average only 25 percent of debris-fan volume is reworked, leading to storage of sand in the matrix of debris fans. We develop a sediment-yield model for debris flows that uses a logistic-regression model of debris-flow frequency in Grand Canyon, a regression model of debris-flow volumes, particle- size distributions of intact debris-flow deposits, and debris-fan reworking. On average, debris flows deliver between 0.14.106 and 0.30.106 Mg/yr of sediment to debris fans throughout Grand Canyon

  18. Smart substrates: Making multi-chip modules smarter

    SciTech Connect

    Wunsch, T.F.; Treece, R.K.

    1995-05-01

    A novel multi-chip module (MCM) design and manufacturing methodology which utilizes active CMOS circuits in what is normally a passive substrate realizes the `smart substrate` for use in highly testable, high reliability MCMS. The active devices are used to test the bare substrate, diagnose assembly errors or integrated circuit (IC) failures that require rework, and improve the testability of the final MCM assembly. A static random access memory (SRAM) MCM has been designed and fabricated in Sandia Microelectronics Development Laboratory in order to demonstrate the technical feasibility of this concept and to examine design and manufacturing issues which will ultimately determine the economic viability of this approach. The smart substrate memory MCM represents a first in MCM packaging. At the time the first modules were fabricated, no other company or MCM vendor had incorporated active devices in the substrate to improve manufacturability and testability, and thereby improve MCM reliability and reduce cost.

  19. Bioinformatics in High School Biology Curricula: A Study of State Science Standards

    PubMed Central

    Sheppard, Keith

    2008-01-01

    The proliferation of bioinformatics in modern biology marks a modern revolution in science that promises to influence science education at all levels. This study analyzed secondary school science standards of 49 U.S. states (Iowa has no science framework) and the District of Columbia for content related to bioinformatics. The bioinformatics content of each state's biology standards was analyzed and categorized into nine areas: Human Genome Project/genomics, forensics, evolution, classification, nucleotide variations, medicine, computer use, agriculture/food technology, and science technology and society/socioscientific issues. Findings indicated a generally low representation of bioinformatics-related content, which varied substantially across the different areas, with Human Genome Project/genomics and computer use being the lowest (8%), and evolution being the highest (64%) among states' science frameworks. This essay concludes with recommendations for reworking/rewording existing standards to facilitate the goal of promoting science literacy among secondary school students. PMID:18316818

  20. The levantine amber belt

    NASA Astrophysics Data System (ADS)

    Nissenbaum, A.; Horowitz, A.

    1992-02-01

    Amber, a fossil resin, is found in Early Cretaceous sanstones and fine clastics in Lebanon, Jordan, and Israel. The term "Levantine amber belt" is coined for this amber-containing sediment belt. The amber occurs as small nodules of various colors and frequently contains inclusions of macro- and microorganisms. The Lebanese amber contains Lepidoptera and the amber from southern Israel is rich in fungal remains. The source of the amber, based on geochemical and palynological evidence, is assumed to be from a conifer belonging to the Araucariaceae. The resins were produced by trees growing in a tropical near shore environment. The amber was transported into small swamps and was preserved there together with lignite. Later reworking of those deposits resulted in redeposition of the amber in oxidized sandstones.

  1. Developing and validating test items for first-year computer science courses

    NASA Astrophysics Data System (ADS)

    Vahrenhold, Jan; Paul, Wolfgang

    2014-10-01

    We report on the development, validation, and implementation of a collection of test items designed to detect misconceptions related to first-year computer science courses. To this end, we reworked the development scheme proposed by Almstrum et al. (SIGCSE Bulletin 38(4):132-145, 2006) to include students' artifacts and to simultaneously incorporate think-aloud interviews and flash tests. We also investigated to what extent the practical efficiency of detecting certain misconceptions could be increased without significantly affecting the sensitivity of the instrument, and present positive and negative results regarding this goal. The results of a first transfer and implementation study suggest that it is indeed possible to use the test items in a large-scale practical setting - both as diagnostic instruments and as interventions.

  2. Signing on for dirty work: Taking stock of a public psychiatry project from the inside.

    PubMed

    Pope, Leah G; Cubellis, Lauren; Hopper, Kim

    2016-08-01

    As applied anthropologists used to working at arm's length from public psychiatry, we step out of the daily grind to take stock of the challenges of taking on ethnography entrained-harnessed to the implementation of a new program. These include the loss of critical distance, the struggles to negotiate locally viable forms of authority and relevance, the necessity of sustaining a Janus-faced relation with principal players, the urgency of seeing time-sensitive information converted into corrective feedback, and the undeniable attraction of being part of "committed work" with game-changing potential. In so doing, we rework the terms of witnessing and revive an old alternative: that documentary dirty work be reclaimed as a variant of public anthropology, one that transforms the work of application from mere afterthought to integral part of the original inquiry. PMID:27363853

  3. Ammonoxidised lignins as slow nitrogen-releasing soil amendments and CO₂-binding matrix.

    PubMed

    Liebner, Falk; Pour, Georg; de la Rosa Arranz, José Maria; Hilscher, André; Rosenau, Thomas; Knicker, Heike

    2011-09-01

    Nitrogen (N) is a major nutrient element controlling the cycling of organic matter in the biosphere. Its availability in soils is closely related to biological productivity. In order to reduce the negative environmental impact, associated with the application of mineral N-fertilizers, the use of ammonoxidised technical lignins is suggested. They can act as potential slow N-release fertilisers which concomitantly may increase C sequestration of soils by its potential to bind CO₂. The idea of our study was to combine an improved chemical characterisation of ammonoxidised ligneous matter as well as their CO₂-binding potential, with laboratory pot experiments, performed to enable an evaluation of their behaviour and stability during the biochemical reworking occurring in active soils.

  4. Long-term CF6 engine performance deterioration: Evaluation of engine S/N 451-380

    NASA Technical Reports Server (NTRS)

    Kramer, W. H.; Smith, J. J.

    1978-01-01

    The performance testing and analytical teardown of CF6-6D engine serial number 451-380 which was recently removed from a DC-10 aircraft is summarized. The investigative test program was conducted inbound prior to normal overhaul/refurbishment. The performance testing included an inbound test, a test following cleaning of the low pressure turbine airfoils, and a final test after leading edge rework and cleaning the stage one fan blades. The analytical teardown consisted of detailed disassembly inspection measurements and airfoil surface finish checks of the as-received deteriorated hardware. Aspects discussed include the analysis of the test cell performance data, a complete analytical teardown report with a detailed description of all observed hardware distress, and an analytical assessment of the performance loss (deterioration) relating measured hardware conditions to losses in both specific fuel comsumption and exhaust gas temperature.

  5. Sound continuing bonds with the deceased: the relevance of music, including preloss music therapy, for eight bereaved caregivers.

    PubMed

    O'Callaghan, Clare C; McDermott, Fiona; Hudson, Peter; Zalcberg, John R

    2013-02-01

    This study examines music's relevance, including preloss music therapy, for 8 informal caregivers of people who died from cancer. The design was informed by constructivist grounded theory and included semistructured interviews. Bereaved caregivers were supported or occasionally challenged as their musical lives enabled a connection with the deceased. Music was often still used to improve mood and sometimes used to confront grief. Specific music, however, was sometimes avoided to minimize sadness. Continuing bonds theory's focus on connecting with the deceased through memory and imagery engagement may expand to encompass musical memories, reworking the meaning of familiar music, and discovering new music related to the deceased. Preloss music involvement, including music therapy, between dying patients and families can help in bereavement. PMID:24520844

  6. Social learning theory and public perception of GMOs: What Blancke et al. (2015) and other plant biotechnologists are missing.

    PubMed

    Fluegge, Keith

    2016-07-01

    There exists a wide chasm between public opinion and scientific evidence on the safety of genetically engineered food, herein referred to as GMOs. Plant biotechnologists give credit to a small community of activists negatively influencing individual minds on this issue, but this approach neglects other social contexts in which such cognition operates. The author argues here that current public opinion on GMOs is a manifestation of the constant interaction between environmental, behavioral, and cognitive influences on this issue. In order to sway public opinion and be consistent with social learning theory, biotechnology advocates and plant scientists will need to move beyond their recognized expertise in order to rework the argument for GMOs in the modern-day food supply, one that wholly embraces an individual-level framing of the debate, tantamount to other successful professional trends like patient-centered medicine. © 2016 Society of Chemical Industry. PMID:26799696

  7. Textual alchemy: the transformation of pseudo-Albertus Magnus's Semita recta into the Mirror of Lights.

    PubMed

    Grund, Peter

    2009-11-01

    This article explores the strategies of and the reasons behind the reworking of pseudo-Albertus Magnus's Semita recta into the Mirror of Lights. I argue that the redactor sought to provide a more comprehensive defence of the legitimacy of alchemy than found in the Semita recta. In the process of doing so, he reshaped the original text so as to present three units that addressed different parts of the alchemical opus: first, theory and justification of alchemy; second, basic information on substances and procedures; and, third, practice. The redactor employed sophisticated textual tools identical to those seen in scholastic texts. These strategies, I argue, constitute part of the redactor's attempt to bring authority and credibility to his project and to alchemy in general. Certainly, much more attention needs to be paid to these experiments of textual alchemy in order to understand the practice of alchemy in the late medieval period. PMID:20506702

  8. Recyclable, strong thermosets and organogels via paraformaldehyde condensation with diamines.

    PubMed

    García, Jeannette M; Jones, Gavin O; Virwani, Kumar; McCloskey, Bryan D; Boday, Dylan J; ter Huurne, Gijs M; Horn, Hans W; Coady, Daniel J; Bintaleb, Abdulmalik M; Alabdulrahman, Abdullah M S; Alsewailem, Fares; Almegren, Hamid A A; Hedrick, James L

    2014-05-16

    Nitrogen-based thermoset polymers have many industrial applications (for example, in composites), but are difficult to recycle or rework. We report a simple one-pot, low-temperature polycondensation between paraformaldehyde and 4,4'-oxydianiline (ODA) that forms hemiaminal dynamic covalent networks (HDCNs), which can further cyclize at high temperatures, producing poly(hexahydrotriazine)s (PHTs). Both materials are strong thermosetting polymers, and the PHTs exhibited very high Young's moduli (up to ~14.0 gigapascals and up to 20 gigapascals when reinforced with surface-treated carbon nanotubes), excellent solvent resistance, and resistance to environmental stress cracking. However, both HDCNs and PHTs could be digested at low pH (<2) to recover the bisaniline monomers. By simply using different diamine monomers, the HDCN- and PHT-forming reactions afford extremely versatile materials platforms. For example, when poly(ethylene glycol) (PEG) diamine monomers were used to form HDCNs, elastic organogels formed that exhibited self-healing properties.

  9. Stratigraphy of the Colorado Creek mammoth locality, Alaska

    NASA Astrophysics Data System (ADS)

    Thorson, Robert M.; Guthrie, R. Dale

    1992-03-01

    The Colorado Creek mammoth locality in west-central Alaska contains the remains of two mammoths that were scavenged by carnivores. Sedimentologic interpretations of the reworked eolian deposits surrounding the bones, supplemented by 10 radiocarbon dates, indicate that the lower and upper mammoths died and were buried within separate, but superimposed, thaw gullies about 23,000 and 16,000 yr ago, respectively. From our results, we propose a polycyclic taphonomic model for thaw gullies governed largely by slope aspect, rather than regional climate, and in which mixing between faunal horizons is more likely than not. Variations in the rate of silt influx and the position of the permafrost table provide a paleoclimatic proxy record that can be correlated to other records in eastern Beringia.

  10. Advanced Code for Photocathode Design

    SciTech Connect

    Ives, Robert Lawrence; Jensen, Kevin; Montgomery, Eric; Bui, Thuc

    2015-12-15

    The Phase I activity demonstrated that PhotoQE could be upgraded and modified to allow input using a graphical user interface. Specific calls to platform-dependent (e.g. IMSL) function calls were removed, and Fortran77 components were rewritten for Fortran95 compliance. The subroutines, specifically the common block structures and shared data parameters, were reworked to allow the GUI to update material parameter data, and the system was targeted for desktop personal computer operation. The new structures overcomes the previous rigid and unmodifiable library structures by implementing new, materials library data sets and repositioning the library values to external files. Material data may originate from published literature or experimental measurements. Further optimization and restructuring would allow custom and specific emission models for beam codes that rely on parameterized photoemission algorithms. These would be based on simplified and parametric representations updated and extended from previous versions (e.g., Modified Fowler-Dubridge, Modified Three-Step, etc.).

  11. Approximated solutions to Born-Infeld dynamics

    NASA Astrophysics Data System (ADS)

    Ferraro, Rafael; Nigro, Mauro

    2016-02-01

    The Born-Infeld equation in the plane is usefully captured in complex language. The general exact solution can be written as a combination of holomorphic and anti-holomorphic functions. However, this solution only expresses the potential in an implicit way. We rework the formulation to obtain the complex potential in an explicit way, by means of a perturbative procedure. We take care of the secular behavior common to this kind of approach, by resorting to a symmetry the equation has at the considered order of approximation. We apply the method to build approximated solutions to Born-Infeld electrodynamics. We solve for BI electromagnetic waves traveling in opposite directions. We study the propagation at interfaces, with the aim of searching for effects susceptible to experimental detection. In particular, we show that a reflected wave is produced when a wave is incident on a semi-space containing a magnetostatic field.

  12. Venusian geology coming into focus

    NASA Astrophysics Data System (ADS)

    Kerr, R. A.

    1984-05-01

    Venera 15 and 16 spacecraft radar images of 1.3-km resolution have confirmed that areas in the Venusian Ishtar Terra highlands appear to be crust which has been folded and faulted into mountains by horizontal compression. The new images also reveal crust that has been broken up by extension, and a depression designated Colette, on a plain on Ishtar Terra, is an obvious crater whose lava flows merge into and form that plain. The ability to distinguish between impact craters and volcanoes has allowed Soviet researchers to compare the number of obvious impact craters against the rate at which they would be expected to form. The resulting average age of the area observed thus far is about 1 billion years. This suggests that the surface has been reworked during the 4.5 billion year history of Venus.

  13. Temporary Thermocouple Attachment for Thermal/Vacuum Testing at Non-Extreme Temperatures

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene K.; Wright, Sarah E.

    2016-01-01

    Post-test examination and data analysis that followed a two week long vacuum test showed that numerous self-stick thermocouples became detached from the test article. The thermocouples were reattached with thermally conductive epoxy and the test was repeated to obtain the required data. Because the thermocouple detachment resulted in significant expense and rework, it was decided to investigate the temporary attachment methods used around NASA and to perform a test to assess their efficacy. The present work describes the original test and the analysis that showed that the thermocouples had become detached, temporary thermocouple attachment methods assessed in the retest and in the thermocouple attachment test, and makes a recommendation for attachment methods for future tests.

  14. Object relations in Harry Potter.

    PubMed

    Lake, Suzanne

    2003-01-01

    Good fiction helps children address their emotional dilemmas by evoking repressed content, and offering strategies and meaningful values that help them work towards resolutions. Because certain fundamental conflicts continue to be revisited and reworked throughout adulthood, it follows that masterful children's literature might enthrall adults as well. Given the extraordinary, worldwide success of the Harry Potter stories with both children and adults, it might be inferred that they, indeed, are among such literature. Common object relations themes, as well as other intrapsychic processes, are presented in such an imaginative and resonant way that the unconscious is readily engaged. The character of Harry Potter, specifically, embodies such universal (repressed) torments as the agony of destroying and losing the mother; the ominous perception of good and bad objects at war within the self; and the earnest reparative efforts offered to save the self from eternal separation from the beloved other.

  15. The deathly hallows: Harry Potter and adolescent development.

    PubMed

    Rosegrant, John

    2009-12-01

    The enormous popularity of the Harry Potter books points to the deep resonance readers feel with the psychological issues they bring to life. Three developmental issues provide central themes: the necessity for partial disenchantment and increasing attunement to reality, while retaining a capacity for wonder; repudiation or endorsement of the narcissistic solution to life's difficulties; and aggression and castration fantasies while growing into adult power. These developmental issues are particularly acute during adolescence but start earlier and continue to be reworked throughout the life span, accounting for the books' appeal to a wide age-range of readers despite their apparent focus on adolescence. These developmental themes are explored in order to better understand the Harry Potter books, as, conversely, the books are explored in order to better understand these themes.

  16. The destructive 1946 Unimak near-field tsunami: New evidence for a submarine slide source from reprocessed marine geophysical data

    NASA Astrophysics Data System (ADS)

    Huene, Roland; Kirby, Stephen; Miller, John; Dartnell, Peter

    2014-10-01

    The Mw 8.6 earthquake in 1946 off the Pacific shore of Unimak Island at the end of the Alaska Peninsula generated a far-field tsunami that crossed the Pacific to Antarctica. Its tsunami magnitude, 9.3, is comparable to the 9.1 magnitude of the 2011 Tohoku tsunami. On Unimak Island's Pacific shore, a runup of 42 m destroyed the lighthouse at Scotch Cap. Elsewhere, localized tsunamis with such high runups have been interpreted as caused by large submarine landslides. However, previous to this study, no landslide large enough to generate this runup was found in the area that is limited by the time interval between earthquake shaking and tsunami inundation at Scotch Cap. Reworking of a seismic reflection transect and colocated multibeam bathymetric surveys reveal a landslide block that may explain the 1946 high runup. It is seaward of Scotch Cap on the midslope terrace and within the time-limited area.

  17. Hybrid sodium heat pipe receivers for dish/Stirling systems

    SciTech Connect

    Laing, D.; Reusch, M.

    1997-12-31

    The design of a hybrid solar/gas heat pipe receiver for the SBP 9 kW dish/Stirling system using a United Stirling AB V160 Stirling engine and the results of on-sun testing in alternative and parallel mode will be reported. The receiver is designed to transfer a thermal power of 35 kW. The heat pipe operates at around 800 C, working fluid is sodium. Operational options are solar-only, gas augmented and gas-only mode. Also the design of a second generation hybrid heat pipe receiver currently developed under a EU-funded project, based on the experience gained with the first hybrid receiver, will be reported. This receiver is designed for the improved SPB/L. and C.-10 kW dish/Stirling system with the reworked SOLO V161 Stirling engine.

  18. Contamination Sources Effects Analysis (CSEA) - A Tool to Balance Cost/Schedule While Managing Facility Availability

    NASA Technical Reports Server (NTRS)

    Wilcox, Margaret

    2008-01-01

    A CSEA is similar to a Failure Modes Effects Analysis (FMEA). A CSEA tracks risk, deterrence, and occurrence of sources of contamination and their mitigation plans. Documentation is provided spanning mechanical and electrical assembly, precision cleaning, thermal vacuum bake-out, and thermal vacuum testing. These facilities all may play a role in contamination budgeting and reduction ultimately affecting test and flight. With a CSEA, visibility can be given to availability of these facilities, test sequencing and trade-offs. A cross-functional team including specialty engineering, contamination control, electrostatic dissipation, manufacturing, testing, and material engineering participate in an exercise that identifies contaminants and minimizes the complexity of scheduling these facilities considering their volatile schedules. Care can be taken in an efficient manner to insure correct cleaning processes are employed. The result is reduction in cycle time ("schedule hits"), reduced cost due to rework, reduced risk and improved communication and quality while achieving adherence to the Contamination Control Plan.

  19. Slim-hole drilling in harsh environments

    SciTech Connect

    Fultz, J.D.; Pittard, F.J. ); Sawyer, F.D. ); Farmer, W.R. )

    1991-09-01

    This paper reports on wells with small liners which require unique methods of drilling, completion, and reworking, especially deep hole wells and wells with severe doglegs. Innovative drilling procedures were used successfully on two oil wells with those downhole conditions. On the first well, cement was drilled in a 3 1/2-in. liner with a small mud motor and heavyweight mud. On the second well, a large mud motor was used as a downhole power swivel to drill in a 3 1/2-in liner. both jobs were completed at depths of 13,000 to 20,000 ft with mud weight {gt}18 lbm/gal and bottomhole temperatures (BHT's) {gt}300{degrees} F.

  20. Energy-Saving Melting and Revert Reduction (E-SMARRT): Energy Efficiency Instrumentation

    SciTech Connect

    Peters, Frank; Frank, Matthew

    2013-12-31

    As with any manufacturing operation, the metalcasting processes have several sources of variation. Additionally, the metalcasting industry routinely produces a wide variety of complex shaped components, which often exacerbates the problem of determining the source of variation. The goals of this project were to develop better tools and strategies to collect and manage process and product information. Based on industry feedback, five areas were selected based on the amount of variation caused by this source or the potential for improvement in terms of energy, emissions and competitiveness. These five areas were: 1. Heat Treatment Control Strategies 2. Semi-Automated Grinding 3. Surface Mapping Software 4. Study of Impact of Repairs via Weld Gouges 5. Rapid Pattern Making Machine This project collectively looked at areas of the steel casting production process which could help reduce the rework, scrap and energy consumption required. Through these efforts, casting producers are better equipped to control their processes and specify processes that better meet their customers’ needs.

  1. Dual radiotracer measurement of zoobenthos-mediated solute and particle transport in freshwater sediments

    NASA Astrophysics Data System (ADS)

    Krezoski, John R.; Robbins, John A.; White, David S.

    1984-09-01

    Gamma spectroscopy methods have been applied to determine the effects of Stylodrilus heringianus and Pontoporeia hoyi, two freshwater benthic macroinvertebrates, on the reworking of sediments and the transfer of solutes across the sediment-water interface. Natural lake sediments (sieved to remove organisms) and overlying water were contained in temperature-regulated rectangular plastic cells. A submillimeter layer of sediment solids labeled with 137Cs was deposited on the sediment interface while overlying water was spiked with 22Na. After addition of Stylodrilus (oligochaete worms) and Pontoporeia (crustacean amphipods) to these microcosms, the vertical distributions of 137Cs (a tracer of particle transport) and 22Na (a tracer of solute transport) were determined at daily to weekly intervals for 3 months by scanning the length of the cells with a well-collimated NaI detector. In cells with Stylodrilus, the 137Cs layer moved downward at a rate that decreased exponentially with time. The displacement of the layer is the result of the conveyor-belt feeding mode of this organism. The rate of marked layer burial is consistent with that of other freshwater annelids (0.18×10-5 cm d-1 individual-1 m-2; 11.6°C). The exponential decrease in burial rate is ascribed to uniformly distributed feeding of Stylodrilus within the feeding zone of 4.4 cm. In cells with Pontoporeia, 137Cs activity was smeared downward in time owing to eddy diffusive mixing of sediments over a small range (1-2 cm). In cells without worms, the veneer of Cs active material remained at the interface while the penetration of 22Na into sediments was consistent with diffusion in free solution with small corrections for sediment porosity and sorption (KD = 0.17). The effective diffusion coefficient De for 22Na in this cell (8.2×10-6 cm2 s-1) was essentially the same as that for a cell that had been inhabited by worms for 3 weeks and then poisoned with formalin just before addition of 22Na. Thus the

  2. Long-term CF6 engine performance deterioration: Evaluation of engine S/N 451-479

    NASA Technical Reports Server (NTRS)

    Kramer, W. H.; Smith, J. J.

    1978-01-01

    The performance testing and analytical teardown of CF6-6D engine is summarized. This engine had completed its initial installation on DC-10 aircraft. The investigative test program was conducted inbound prior to normal overhaul/refurbishment. The performance testing included an inbound test, a test following cleaning of the low pressure turbine airfoils, and a final test after leading edge rework and cleaning the stage one fan blades. The analytical teardown consisted of detailed disassembly inspection measurements and airfoil surface finish checks of the as received deteriorated hardware. Included in this report is a detailed analysis of the test cell performance data, a complete analytical teardown report with a detailed description of all observed hardware distress, and an analytical assessment of the performance loss (deterioration) relating measured hardware conditions to losses in both SFC (specific fuel consumption) and EGT (exhaust gas temperature).

  3. Bottom currents and shelf sediments, southwest of Britain

    NASA Astrophysics Data System (ADS)

    Hamilton, D.; Sommerville, J. H.; Stanford, P. N.

    1980-04-01

    The shelf sediments southwest of Britain range from large boulders to muddy fine sands. The large boulders, which occur in patches, were probably dropped from icebergs. A reworked basal bed forms an extensive pavement over which well to very well sorted medium to fine sands are transported, whilst muddy sediments occur between sandbanks. Measurements of boundary layer currents show that the threshold friction velocities for the sands are exceeded by maximum tidal flows over most of the area. Repeated selective entrainment by tidal currents, in a virtually closed sediment system, is proposed as the mechanism for the formation of these very well sorted mobile sands, which have a mean size close to that of the most easily entrained grains and size frequency distributions approaching log-normality.

  4. Control of Quaternary sea-level changes on gas seeps

    NASA Astrophysics Data System (ADS)

    Riboulot, Vincent; Thomas, Yannick; Berné, Serge; Jouet, Gwénaël.; Cattaneo, Antonio

    2014-07-01

    Gas seeping to the seafloor through structures such as pockmarks may contribute significantly to the enrichment of atmospheric greenhouse gases and global warming. Gas seeps in the Gulf of Lions, Western Mediterranean, are cyclical, and pockmark "life" is governed both by sediment accumulation on the continental margin and Quaternary climate changes. Three-dimensional seismic data, correlated to multi-proxy analysis of a deep borehole, have shown that these pockmarks are associated with oblique chimneys. The prograding chimney geometry demonstrates the syn-sedimentary and long-lasting functioning of the gas seeps. Gas chimneys have reworked chronologically constrained stratigraphic units and have functioned episodically, with maximum activity around sea level lowstands. Therefore, we argue that one of the main driving mechanisms responsible for their formation is the variation in hydrostatic pressure driven by relative sea level changes.

  5. The replacement child--a developmental tragedy: some preliminary comments.

    PubMed

    Legg, C; Sherick, I

    1976-01-01

    Some of the clinical and theoretical issues thought to be involved in the psychology of "replacement children" are discussed. A developmental framework is proposed within which to view such children. The replacement child is becoming an identifiable clinical syndrome, and a developmental framework is sorely needed to encourage more systematic research. A replacement child perceives his status differently on both a cognitive and emotional level within the context of each developmental phase, and the affective and associative links need to be reworked each time. We view the status of being a replacement child as a developmental interference insofar as demands are placed on the child's immature ego which he might not yet be equipped to cope with.

  6. Thermoluminescence dating of the british coversand deposits

    NASA Astrophysics Data System (ADS)

    Bateman, M. D.

    Coversand deposits, thought to be of Lateglacial age are found in Britain in North Lincolnshire, South-West Lancashire and Central East Anglia. A comprehensive dating study of them, using thermoluminescence (TL) techniques, is currently underway in an attempt to link the British coversand deposits to the European coversand chronology. Initial results from four of the British coversand sites sampled are presented. The 26 TL dates from 14 samples show that in Lincolnshire aeolian deposition took place from 12.5 ka to I1 ka. Cessation of the initial sand deposition was synchronous with this in Lancashire, but sand deposition occurred significantly earlier in East Anglia. The upper layers of aeolian sand in Lancashire are much younger and are attributed to Holocene reworking. On the basis of these dates, Lincolnshire and Lancashire coversand deposition occurred at a similar time to the Younger Coversand II, whilst East Anglian coversand deposition coincided with the Younger Coversand I phase in the European coversand chronology.

  7. Application of ground-penetrating radar at McMurdo Station, Antarctica

    SciTech Connect

    Stefano, J.E.

    1992-05-01

    Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

  8. Application of ground-penetrating radar at McMurdo Station, Antarctica

    SciTech Connect

    Stefano, J.E.

    1992-01-01

    Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

  9. Evidence and dating of mid-Cretaceous tectonic activity in the San Rafael Swell, Emery County, Utah

    SciTech Connect

    Eaton, J.G. ); Kirkland, J.I. ); Kauffman, E.G. )

    1990-04-01

    Evidence of tectonic activity in the form of recycled conglomerates has been found in middle Cretaceous deposits on the western flank of the San Rafael Swell. These conglomerates, present in the upper part of the Dakota Formation and in the overlying basal Mancos Shale (Tununk Member), are separated by an earliest Turonian unconformity. The conglomerates appear to be derived from the Lower Cretaceous Buckhorn Conglomerate, or similar conglomerates, which were re-exposed by latest Cenomanian uplift. Coarse clastics provided to the nearshore facies of the Dakota Formation by coastal rivers are preserved as a coarsening upward sequence. Continued uplift eventually caused a local marine regression by temporarily inhibiting the initial (latest Cenomanian) transgression of the Greenhorn Sea. In subaerially exposed environments pebbles and cobbles from the Buckhorn were distributed across the coastal floodplain by rivers. These clasts were reworked into a basal lag deposit when renewed transgression of the Greenhorn Sea occurred during the late early Turonian.

  10. The Montesbelos mass-flow (southern Amazonian craton, Brazil): a Paleoproterozoic volcanic debris avalanche deposit?

    NASA Astrophysics Data System (ADS)

    Roverato, M.

    2016-07-01

    The present contribution documents the extremely well-preserved Paleoproterozoic architecture of the Montesbelos breccia (named here for the first time), which is interpreted as a rare example of a subaerial paleoproterozoic (>1.85 Ga) granular-dominated mass-flow deposit, few of which are recorded in the literature. Montesbelos deposit is part of the andesitic Sobreiro Formation located in the São Felix do Xingu region, southern Amazonian craton, northern Brazil. The large volume, high variability of textural features, presence of broken clasts, angular low sphericity fragments, mono- to heterolithic character, and the size of the outcrops point to a volcanic debris avalanche flow. Fluviatile sandy material and debris flows are associated with the deposit as a result of post-depositional reworking processes.

  11. A possible tsunami deposit around the Jurassic Cretaceous boundary in the Boulonnais area (northern France)

    NASA Astrophysics Data System (ADS)

    Schnyder, Johann; Baudin, François; Deconinck, Jean-François

    2005-06-01

    An unusual succession of facies locally deposited around the Jurassic-Cretaceous boundary in the Boulonnais (northern France) is attributed to a tsunami event by comparison with recent tsunami deposits. This sedimentary succession includes basal erosion with reworked lithified blocks, soft-sediment deformations, an erosional conglomerate overlain by wood fragments and clays containing continental and marine fossils in one setting and conglomerate with mixed fauna in an other setting. The tsunami probably affected the coast of the Boulonnais area of the London-Brabant Massif. The origin of the event is unknown. It was most probably triggered by an earthquake, but other origins such as volcanic eruptions, a giant landslide, or even the impact of an extraterrestrial bolide into the ocean may also be considered.

  12. Pb isotopic evidence for early Archaean crust in South Greenland

    NASA Technical Reports Server (NTRS)

    Taylor, P. N.; Kalsbeek, F.

    1986-01-01

    The results of an isotopic remote sensing study focussed on delineating the extent of Early Archean crust north and south of the Nuuk area and in south Greenland is presented. Contamination of the Late Archean Nuk gneisses and equivalents by unradiogenic Pb uniquely characteristic of Amitsoq gneiss was detected as far south as Sermilik about 70 km south of Nuuk and only as far north as the mouth of Godthabsfjord. This study was extended to the southern part of the Archean craton and the adjoining Early Proterozoic Ketilidian orogenic belt where the Pb isotopes suggest several episodes of reworking of older uranium depleted continental crust. The technique of using the Pb isotope character of younger felsic rocks, in this case Late Archean and Early Proterozoic gneisses and granites to sense the age and isotopic character of older components, is a particularly powerful tool for reconstructing the evolutionary growth and development of continental crust.

  13. Shallow sedimentary framework of Georges Bank

    USGS Publications Warehouse

    Lewis, R.S.; Sylwester, R.E.

    1976-01-01

    Two thousand nine hundred kilometers of minisparker data were collected on Georges Bank by the United States Geological Survey during October of 1975. Several sedimentary features have been observed in the data, The bank is recognized as a compound feature resulting from erosion of Tertiary coastal-plain strata followed by deposition of an extensive sediment wedge on the western flank of the cuesta. Marine planation (probably Late Pleistocene) truncated this bank morphology producing an erosion surface roughly paralleling the present sea floor. The truncated bank surface is blanketed by a veneer of complex Late Pleistocene drift which masks underlying features and is being reworked by modern processes. Present bank morphology is inferred-to be arather recent development. A proper understanding of the significance of complex bank sediments with respect to the potential geologic hazards of drilling or placement of bottom. supported structures necessitates a more detailed seismic reflection program, in conjunction with geotechnical analysis of core-samples.

  14. Remnants of an ancient forest provide ecological context for Early Miocene fossil apes.

    PubMed

    Michel, Lauren A; Peppe, Daniel J; Lutz, James A; Driese, Steven G; Dunsworth, Holly M; Harcourt-Smith, William E H; Horner, William H; Lehmann, Thomas; Nightingale, Sheila; McNulty, Kieran P

    2014-01-01

    The lineage of apes and humans (Hominoidea) evolved and radiated across Afro-Arabia in the early Neogene during a time of global climatic changes and ongoing tectonic processes that formed the East African Rift. These changes probably created highly variable environments and introduced selective pressures influencing the diversification of early apes. However, interpreting the connection between environmental dynamics and adaptive evolution is hampered by difficulties in locating taxa within specific ecological contexts: time-averaged or reworked deposits may not faithfully represent individual palaeohabitats. Here we present multiproxy evidence from Early Miocene deposits on Rusinga Island, Kenya, which directly ties the early ape Proconsul to a widespread, dense, multistoried, closed-canopy tropical seasonal forest set in a warm and relatively wet, local climate. These results underscore the importance of forested environments in the evolution of early apes.

  15. An attachment model of depression: integrating findings from the mood disorder laboratory.

    PubMed

    Holmes, Jeremy

    2013-01-01

    This paper is written from a psychodynamic clinician's perspective, juxtaposing a psychoanalytic-attachment model of depression with recent developments in neuroscience. Three main components of the attachment approach are described: the role of loss, of childhood trauma predisposing to depression in later life, and failure of co-regulation of role of primitive emotions, such as fear, despair, and helplessness. Blatt's distinction between anaclitic and introjective depression is delineated and related to hyper- and de-activation of the attachment dynamic. Recent advances in evolutionary, sociological, epigenetic, biochemical, and neuro-imaging studies of depression are reviewed. A dynamic model of depression is proposed, linking interpersonal and intra-psychic perspectives with neuro-anatomical models. The final section of the paper considers the specific role of psychodynamic approaches to the treatment of refractory depression. These include length of treatment, capacity to rework implicit memories, and focus on transference and counter-transference. PMID:23458116

  16. The dream screen: phenomenon and noumenon.

    PubMed

    Abse, D W

    1977-01-01

    The dream screen as described by Lewin may have been confused at times with the phenomenon of functional symbolism portraying heightened repressive resistance, and at other times with a negative hallucination in secondary revision. In some dreams, when the sleep-guarding function of the preconscious is heavily threatened and requires reinforcement, a screen certainly appears. Its essential shielding function has evolved from oral fantasies of gratification at the breast, and this origin places it in the context of other phenomena, including the Isakower phenomenon. It is contended that Lewin's assumption that reported dreamless sleep indicates the presence of the screen without projections on its surface transcends development from the perceptual to the conceptual, to the noumenal. The manifest screen is shown to be part of the dream work to achieve pleasurable repose conducive to continued sleep; disturbing traumatic narcissistic injuries revisited under its shield are sometimes reworked in extravagant megalomanic efforts at repair.

  17. Combining sequence stratigraphy with 3-D seismic imaging in low-accommodation basins

    SciTech Connect

    Hardage, B.A.; Carr, D.L.; Simmons, J.L. Jr.

    1995-12-31

    Pennsylvania-age rocks in several areas of the Midcontinent of the United States were deposited in low-accommodation basinal settings, that is, in basinal areas where only modest verticle reliefs could accept the sediment influx. Many thin Pennsylvanian sequences in these low-accommodation environments exhibit severe lateral heterogeneity because they have been extensively reworked by repeated transgressions and regressions of a fluctuating sea. Consequently, the distinctive geometries of relic depositional features (such as meandering channels) tend to be distorted or even totally destroyed, as compared with how such geometries appear in high-accommodation basins where depositional topography, once buried, is rarely exposed to destructive processes. Our objectives are to show examples of 3-D seismic images of several depositional topographies in a moderate- to low-accommodation basin and to explain how these thin sequences can be identified in well control and interpreted in 3-D seismic data volumes.

  18. Getting JWST's NIRSpec back in shape

    NASA Astrophysics Data System (ADS)

    te Plate, Maurice; Birkmann, Stephan; Rumler, Peter; Jensen, Peter; Eder, Robert; Ehrenwinkler, Ralf; Merkle, Frank; Mosner, Peter; Roedel, Andreas; Speckmaier, Max; Johnson, Thomas E.; Mott, Brent; Snodgrass, Stephen

    2016-07-01

    The James Webb Space Telescope (JWST) Observatory is the follow-on mission to the Hubble Space Telescope. JWST will be the biggest space telescope ever built and it will lead to astounding scientific breakthroughs. The mission will be launched in October 2018 from Kourou, French Guyana by an ESA provided Ariane 5 rocket. NIRSpec, one of the four instruments on board of the mission, recently underwent a major upgrade. New infrared detectors were installed and the Micro Shutter Assembly (MSA) was replaced as well. The rework was necessary because both systems were found to be degrading beyond a level that could be accepted. The techniques and procedures that were applied during this campaign will be elaborated in this paper. Some first cold test results of the upgraded instrument will be presented as well.

  19. Unexpected biotic resilience on the Japanese seafloor caused by the 2011 Tōhoku-Oki tsunami

    NASA Astrophysics Data System (ADS)

    Toyofuku, Takashi; Duros, Pauline; Fontanier, Christophe; Mamo, Briony; Bichon, Sabrina; Buscail, Roselyne; Chabaud, Gérard; Deflandre, Bruno; Goubet, Sarah; Grémare, Antoine; Menniti, Christophe; Fujii, Minami; Kawamura, Kiichiro; Koho, Karoliina Annika; Noda, Atsushi; Namegaya, Yuichi; Oguri, Kazumasa; Radakovitch, Olivier; Murayama, Masafumi; de Nooijer, Lennart Jan; Kurasawa, Atushi; Ohkawara, Nina; Okutani, Takashi; Sakaguchi, Arito; Jorissen, Frans; Reichart, Gert-Jan; Kitazato, Hiroshi

    2014-12-01

    On March 11th, 2011 the Mw 9.0 2011 Tōhoku-Oki earthquake resulted in a tsunami which caused major devastation in coastal areas. Along the Japanese NE coast, tsunami waves reached maximum run-ups of 40 m, and travelled kilometers inland. Whereas devastation was clearly visible on land, underwater impact is much more difficult to assess. Here, we report unexpected results obtained during a research cruise targeting the seafloor off Shimokita (NE Japan), shortly (five months) after the disaster. The geography of the studied area is characterized by smooth coastline and a gradually descending shelf slope. Although high-energy tsunami waves caused major sediment reworking in shallow-water environments, investigated shelf ecosystems were characterized by surprisingly high benthic diversity and showed no evidence of mass mortality. Conversely, just beyond the shelf break, the benthic ecosystem was dominated by a low-diversity, opportunistic fauna indicating ongoing colonization of massive sand-bed deposits.

  20. A coral-rubble ridge as evidence for hurricane overwash, Anegada (British Virgin Islands)

    NASA Astrophysics Data System (ADS)

    Spiske, M.; Halley, R. B.

    2014-01-01

    A coral-rubble ridge fringes part of the north shore of Anegada, a low-lying island in the northern Caribbean. Both historical reports and the geological record underline its vulnerability to tsunami and hurricanes. In this study we document the sedimentary characteristics of a coral-rubble ridge, which extends discontinuously along 1.5-1.8 km of chiefly north-facing shores at Soldier Wash. The ridge is less distinctive and appears only in patches along the west-facing shoreline at Windless Bight, where the wave regime is calmer. It is located ca. 8 m from the fair-weather shore, has a maximum width of 15 m and a maximum thickness of 0.8 m. The lower seaward-facing slope of the ridge is relatively flat, probably due to successive reworking, whereas the upper seaward slope is steep and partly displays avalanching faces. The landward flank is gently sloping and terminates abruptly. The ridge is mainly composed of well-rounded, encrusted and bored coral rubble (average diameter of 16 cm) that has been reworked in the shallow marine environment prior to transport. Only a few pieces of angular beach rock and karstified Pleistocene limestone are incorporated. The components build a clast-supported framework. No sand is present in the interstices. Imbrication of flat clasts indicates a deposition during landward bed load transport. The ridge morphology, composition and related hydrodynamic conditions during its emplacement are typical for coral-rubble ridges deposited by hurricane-induced storm surges. In comparison, nearby evidence for tsunami inundation is very different because the tsunami-transported coral boulders on Anegada are much bigger (2 m) than the biggest components in the ridge, they are deposited much farther inland (up to 1.5 km), and the corals seem to have been freshly broken out of the reef by the tsunami. The age of the ridge is difficult to estimate. The dark grey surface of the ridge is caused by bioweathering by endolithic organisms that takes tens

  1. Nd and Sr isotope compositions in modern and fossil bones - Proxies for vertebrate provenance and taphonomy

    NASA Astrophysics Data System (ADS)

    Tütken, Thomas; Vennemann, Torsten W.; Pfretzschner, Hans-U.

    2011-10-01

    Rare earth elements (REE), while not essential for the physiologic functions of animals, are ingested and incorporated in ppb concentrations in bones and teeth. Nd isotope compositions of modern bones of animals from isotopically distinct habitats demonstrate that the 143Nd/ 144Nd of the apatite can be used as a fingerprint for bedrock geology or ambient water mass. This potentially allows the provenance and migration of extant vertebrates to be traced, similar to the use of Sr isotopes. Although REE may be enriched by up to 5 orders of magnitude during diagenesis and recrystallization of bone apatite, in vivo143Nd/ 144Nd may be preserved in the inner cortex of fossil bones or enamel. However, tracking the provenance of ancient or extinct vertebrates is possible only for well-preserved archeological and paleontological skeletal remains with in vivo-like Nd contents at the ppb-level. Intra-bone and -tooth REE analysis can be used to screen for appropriate areas. Large intra-bone Nd concentration gradients of 10 1-10 3 are often measured. Nd concentrations in the inner bone cortex increase over timescales of millions of years, while bone rims may be enriched over millenial timescales. Nevertheless, ɛ Nd values are often similar within one ɛ Nd unit within a single bone. Larger intra-bone differences in specimens may either reflect a partial preservation of in vivo values or changing ɛ Nd values of the diagenetic fluid during fossilization. However, most fossil specimens and the outer rims of bones will record taphonomic 143Nd/ 144Nd incorporated post mortem during diagenesis. Unlike REE patterns, 143Nd/ 144Nd are not biased by fractionation processes during REE-uptake into the apatite crystal lattice, hence the ɛ Nd value is an important tracer for taphonomy and reworking. Bones and teeth from autochthonous fossil assemblages have small variations of ±1 ɛ Nd unit only. In contrast, fossil bones and teeth from over 20 different marine and terrestrial fossil

  2. Novel methods of bonding solar cells

    NASA Astrophysics Data System (ADS)

    Thomaier, Rob

    2011-09-01

    Messy liquid adhesives, short work times, long cure times, difficult clean-up of stray adhesive - all of these are associated with liquid adhesives for bonding solar cells. Current adhesion methods have been in place since the '70s: mix a two-part liquid silicone adhesive, coat a portion of adhesive onto a section of substrate, place the cells in a vacuum bag and wait for the adhesive to cure. Alternatively, one can use a fairly complicated robotic procedure to apply adhesive then fix a cell down and, again, wait for the adhesive to cure. Some difficulties that need to be overcome include balancing the amount adhesive to spread out with the available worktime in order to get all the cells onto the substrate with good adhesion; controlling the bondline; ensuring that the adhesive cures correctly after application; and, finally, if there is any re-work, removing the part from the adhesive without damaging everything around it.

  3. Evidence for only minor contributions from bacteria to sedimentary organic carbon

    NASA Technical Reports Server (NTRS)

    Hartgers, W. A.; Sinninghe Damste, J. S.; Requejo, A. G.; Allan, J.; Hayes, J. M.; de Leeuw, J. W.

    1994-01-01

    Because their molecular signatures are often prominent in extracts of sediments, bacteria are thought to be important contributors to petroleum source beds. It has been shown recently, however, that abundances of biomarkers do not always reflect relative contributions to sedimentary organic carbon (Corg). The contribution of photosynthetic green sulphur bacteria to sediments can be assessed effectively because the diagenetic products of distinctive carotenoids from these organisms occur widely and their biomass is isotopically labelled, being enriched in 13C. We show here that, although sediments and oils from the Western Canada and Williston basins contain prominent biomarkers of photosynthetic bacteria, the absence of 13C enrichment in the total Corg requires that the bacterial contribution is in fact minimal. Although the importance of bacterial reworking of sedimentary debris cannot be doubted, we argue that our findings, when considered in conjunction with those from other settings, suggest that bacterial biomass may commonly represent only a minor component of total Corg in carbonaceous rocks.

  4. [Metamorphoses of commentary. Editorial projects and formation of anatomical knowledge in the 16th century].

    PubMed

    Mandressi, Rafael

    2005-01-01

    The new anatomical knowledge, which began to come into existence in the first half of the 16th century, generated intellectual and material tools for the acquisition and transmission of knowledge on the basis of a methodological program which reworked the relationship between the written word of the authorities and sensorial observations. The reception and critical evaluation of inherited texts was carried out through the adoption and transformation of modes of writing and editorial devices put into the service of the new relationships to the past history of the discipline in the formation of knowledge of the body. The traditional form of commentary and the techniques which are associated with it, initially adopted by Berengario da Carpi and which are then to be found at the base of Andreas Vesalius' work, played a central role in this sense. PMID:16689078

  5. Sweet Lake geopressured-geothermal project, Magma Gulf-Technadril/DOE Amoco fee. Volume III. Final report. Annual report, February 1982-March 1985

    SciTech Connect

    Durham, C.O. Jr.; O'Brien, F.D.; Rodgers, R.W.

    1985-01-01

    This report presents the results of the testing of Sand 3 (15,245 to 15,280 feet in depth) which occurred from November 1983 to March 1984 and evaluates these new data in comparison to results from the testing of Sand 5 (15,385 to 15,415 feet in depth) which occurred from June 1981 to February 1982. It also describes the reworking of the production and salt water disposal wells preparatory to the Sand 3 testing as well as the plug and abandon procedures requested to terminate the project. The volume contains two parts: Part 1 includes the text and accompanying plates, figures and tables; Part 2 consists of the appendixes including auxiliary reports and tabulations.

  6. First time experiences using SciPy for computer vision research

    SciTech Connect

    Eads, Damian R; Rosten, Edward J

    2008-01-01

    SciPy is an effective tool suite for prototyping new algorithms. We share some of our experiences using it for the first time to support our research in object detection. SciPy makes it easy to integrate C code, which is essential when algorithms operating on large data sets cannot be vectorized. Python's extensive support for operator overloading makes SciPy's syntax as succinct as its competitors, MATLAB. Octave. and R. The universality of Python. the language in which SciPy was written, gives the researcher access to a broader set of non-numerical libraries to support GUI development. interface with databases, manipulate graph structures, render 3D graphics, unpack binary files, etc. More profoundly, we found it easy to rework research code written with SciPy into a production application, deployable on numerous platforms.

  7. Contamination Control in Hybrid Microelectronic Modules. Part 1: Identification of Critical Process and Contaminants

    NASA Technical Reports Server (NTRS)

    Himmel, R. P.

    1975-01-01

    Various hybrid processing steps, handling procedures, and materials are examined in an attempt to identify sources of contamination and to propose methods for the control of these contaminants. It is found that package sealing, assembly, and rework are especially susceptible to contamination. Moisture and loose particles are identified as the worst contaminants. The points at which contaminants are most likely to enter the hybrid package are also identified, and both general and specific methods for their detection and control are developed. In general, the most effective controls for contaminants are: clean working areas, visual inspection at each step of the process, and effective cleaning at critical process steps. Specific methods suggested include the detection of loose particles by a precap visual inspection, by preseal and post-seal electrical testing, and by a particle impact noise test. Moisture is best controlled by sealing all packages in a clean, dry, inert atmosphere after a thorough bake-out of all parts.

  8. Assessment of intelligent processing equipment in the National Aeronautics and Space Administration, 1991

    NASA Astrophysics Data System (ADS)

    Jones, C. S.

    1992-04-01

    Summarized here is an assessment of intelligent processing equipment (IPE) within NASA. An attempt is made to determine the state of IPE development and research in specific areas where NASA might contribute to the national capability. Mechanisms to transfer NASA technology to the U.S. private sector in this critical area are discussed. It was concluded that intelligent processing equipment is finding extensive use in the manufacture of space hardware, especially in the propulsion components of the shuttle. The major benefits are found in improved process consistency, which lowers cost as it reduces rework. Advanced feedback controls are under development and being implemented gradually into shuttle manufacturing. Implementation is much more extensive in new programs, such as in the advanced solid rocket motor and the Space Station Freedom.

  9. Tectonic implications of new single zircon Pb-Pb evaporation data in the Lossogonoi and Longido ruby-districts, Mozambican metamorphic Belt of north-eastern Tanzania

    NASA Astrophysics Data System (ADS)

    Le Goff, Elisabeth; Deschamps, Yves; Guerrot, Catherine

    2010-01-01

    Three single zircon Pb-Pb evaporation dating studies were performed on felsic orthogneisses and migmatites from the Longido and Lossogonoi ruby districts, Mozambique Belt of north-eastern Tanzania, in order to better constrain the geological setting of gemstone mineralizations. Igneous emplacement ages of protoliths ranging between 2636 and 2448 Ma document for the first time the presence of a Neoarchean to Lower Paleoproterozoic (Siderian) basement reworked in the Late Neoproterozoic Mozambique Belt of north-eastern Tanzania. This ancient crust of unknown dimension is well documented farther south, but also in south-eastern Kenya. A shearing event under high-grade amphibolite facies conditions, postdating the Pan-African metamorphic peak at 640 Ma and following nappes emplacement is demonstrated at ca. 610 Ma from metamorphic zircons of Lossogonoi district. In Lossogonoi district, ruby crystallizes during this last stage of deformation.

  10. Remnants of an ancient forest provide ecological context for Early Miocene fossil apes.

    PubMed

    Michel, Lauren A; Peppe, Daniel J; Lutz, James A; Driese, Steven G; Dunsworth, Holly M; Harcourt-Smith, William E H; Horner, William H; Lehmann, Thomas; Nightingale, Sheila; McNulty, Kieran P

    2014-01-01

    The lineage of apes and humans (Hominoidea) evolved and radiated across Afro-Arabia in the early Neogene during a time of global climatic changes and ongoing tectonic processes that formed the East African Rift. These changes probably created highly variable environments and introduced selective pressures influencing the diversification of early apes. However, interpreting the connection between environmental dynamics and adaptive evolution is hampered by difficulties in locating taxa within specific ecological contexts: time-averaged or reworked deposits may not faithfully represent individual palaeohabitats. Here we present multiproxy evidence from Early Miocene deposits on Rusinga Island, Kenya, which directly ties the early ape Proconsul to a widespread, dense, multistoried, closed-canopy tropical seasonal forest set in a warm and relatively wet, local climate. These results underscore the importance of forested environments in the evolution of early apes. PMID:24549336

  11. Investigation of Solder Cracking Problems on Printed Circuit Boards

    NASA Technical Reports Server (NTRS)

    Berkebile, M. J.

    1967-01-01

    A Solder Committee designated to investigate a solder cracking phenomena occurring on the SATURN electrical/electronic hardware found the cause to be induced stress in the soldered connections rather than faulty soldering techniques. The design of the printed circuit (PC) board assemblies did not allow for thermal expansion of the boards that occurred during normal operation. The difference between the thermal expansion properties of the boards and component lead materials caused stress and cracking in the soldered connections. The failure mechanism and various PC boards component mounting configurations are examined in this report. Effective rework techniques using flanged tubelets, copper tubelets, and soft copper wiring are detailed. Future design considerations to provide adequate strain relief in mounting configurations are included to ensure successful solder terminations.

  12. Marrying into the European family of nations: national disorder and upset gender roles in post-Communist Romanian film.

    PubMed

    Georgescu, Diana

    2011-01-01

    Drawing on recent Romanian films, this article explores the distinctive post-communist concerns with national relocation in the symbolic geography of Europe. The focus on tragic comedies, an increasingly popular genre in Eastern European cinematography, foregrounds the critical usage of irony to express skepticism about the inclusive nature of geopolitical projects such as the European Union by national communities situated at its periphery. While the tragic comedies examined here are successful in challenging official narratives of European belonging, they rely on highly gendered scripts that prove more resilient to ironic reworkings. The movies resort to gendered plots and family tropes, representing Romania’s efforts to receive European recognition as attempts to “marry into” the European Union. The larger thrust of this article is to open complex notions such as “Europe,” “nation,” and “gender,” which are notoriously prone to essentialization, to a deconstructive analysis as systems of differentiation.

  13. Phosphogenesis and weathering of shelf sediments from the southeastern United States: Implications for Miocene. delta. sup 13 C excursions and global cooling

    SciTech Connect

    Compton, J.S. ); Snyder, S.W. ); Hodell, D.A. )

    1990-12-01

    The enormous phosphorite deposits of the southeastern United States indicate intense upwelling but contain small amounts of organic carbon. The authors propose that deposition of organic-rich sediment on continental shelves in the southeastern United States and elsewhere during marine transgressions in the late Oligocene and early to middle Miocene resulted in global positive {delta}{sup 13}C shifts and the formation of early diagenetic phosphorite. Multiple reworking and supergene weathering from subaerial exposure during Miocene marine regressions oxidized most of the organic carbon and resulted in the return of {delta}{sup 13}C to its preexcursion value. The estimated phosphorite content of the southeastern United States requires sufficient organic carbon burial (>10{sup 15} kg carbon) to support a 1{per thousand} {delta}{sup 13}C excursions, sea-level fluctuations, organic carbon burial, phosphogenic episodes, and possibly global cooling during the Cenozoic.

  14. Mechanical Devices Readiness FY04.0402.1

    SciTech Connect

    Bender, Thomas R.

    2008-10-10

    This Advanced Design and Production Technologies (ADAPT) project funded production process and tooling improvements to meet and sustain rate production for the program mechanism assemblies. Techniques were developed to allow evaluation and rework of sealed mechanisms that will result in prevention of the scrapping of future mechanisms. Future system mechanisms will likely be smaller with tighter tolerance parts that will require improved inspection equipment and techniques. During the latter phase of this project, the ISL (Intent Stronglink) PRT (Product Realization Team) developed designs and manufacturing processes at Sandia and at multiple KCP (Kansas City Plant) vendors, to produce glass ceramic headers to replace the brazed ceramic headers in the ISL. This achievement will result in significant production costs savings (unit cost and product scrap due to leaking headers).

  15. Mission operations and command assurance: Instilling quality into flight operations

    NASA Technical Reports Server (NTRS)

    Welz, Linda L.; Witkowski, Mona M.; Bruno, Kristin J.; Potts, Sherrill S.

    1993-01-01

    Mission Operations and Command Assurance (MO&CA) is a Total Quality Management (TQM) task on JPL projects to instill quality in flight mission operations. From a system engineering view, MO&CA facilitates communication and problem-solving among flight teams and provides continuous process improvement to reduce the probability of radiating incorrect commands to a spacecraft. The MO&CA task has evolved from participating as a member of the spacecraft team to an independent team reporting directly to flight project management and providing system level assurance. JPL flight projects have benefited significantly from MO&CA's effort to contain risk and prevent rather than rework errors. MO&CA's ability to provide direct transfer of knowledge allows new projects to benefit from previous and ongoing flight experience.

  16. Mission operations and command assurance: Flight operations quality improvements

    NASA Technical Reports Server (NTRS)

    Welz, Linda L.; Bruno, Kristin J.; Kazz, Sheri L.; Potts, Sherrill S.; Witkowski, Mona M.

    1994-01-01

    Mission Operations and Command Assurance (MO&CA) is a Total Quality Management (TQM) task on JPL projects to instill quality in flight mission operations. From a system engineering view, MO&CA facilitates communication and problem-solving among flight teams and provides continuous solving among flight teams and provides continuous process improvement to reduce risk in mission operations by addressing human factors. The MO&CA task has evolved from participating as a member of the spacecraft team, to an independent team reporting directly to flight project management and providing system level assurance. JPL flight projects have benefited significantly from MO&CA's effort to contain risk and prevent rather than rework errors. MO&CA's ability to provide direct transfer of knowledge allows new projects to benefit from previous and ongoing flight experience.

  17. Progress on smoking control in Western Australia.

    PubMed Central

    Musk, A. W.; Shean, R.; Walker, N.; Swanson, M.

    1994-01-01

    In 1990, 20 years of campaigning by the Western Australian branch of the Australian Council on Smoking and Health succeeded in getting tobacco advertising banned in Western Australia and a fund set up to replace the sponsorship of sport by tobacco companies. The council coordinated the activities of the mainly professional medical organisations that formed its members, ensuring that messages about the dangers of tobacco were consistently presented from different angles. The campaigners also ensured that medical data were reworked for presentation to decision makers and public, invaded the corporate world, and minimised opposition by enlisting the support of sportspeople opposed to tobacco sponsorship. The council hopes now that elimination of advertising will reduce the prevalence of smoking. Images p395-a p396-a p397-a PMID:8124149

  18. Irradiation stratigraphy in the Apollo 16 deep drill section 60002

    NASA Technical Reports Server (NTRS)

    Blanford, G. E.; Wood, G. C.

    1978-01-01

    Particle track density frequency distributions, abundance of track rich grains and minimum track densities are reported for the upper 20 cm of the 60002 section of the Apollo 16 deep drill core. The principal stratigraphic feature is a boundary approximately 7 cm from the top of the section. Experimental evidence does not conclusively determine whether this contact is an ancient regolith surface or is simply a depositional boundary. If it is an ancient surface, it has a model exposure age of 3 to 7 million years and a reworking depth of about 0.5 cm. However, because track density frequency distributions indicate the mixing of soils of different maturities, we favor interpreting this contact as a depositional boundary. There may be a second depositional boundary approximately 19 cm below the top of 60002.

  19. Solar and cosmogenic nitrogen in the Apollo 17 deep drill core

    NASA Technical Reports Server (NTRS)

    Thiemens, M. H.; Clayton, R. N.

    1980-01-01

    It is established that the greatest distinction in origin of the soils in the Apollo 17 drill core is between the surface layer, down to 25 cm, and the remainder. The surface layer was not derived by the reworking of underlying material, but was deposited from elsewhere. The soils in the core below 25 cm have had similar surface histories, with first exposure to the solar wind 1.0-1.5 million years ago and accumulation of solar wind continuously over hundreds of millions of years thereafter. The soil with the least, and most ancient, surface exposure is 25-60 cm deep, while that with the greatest and most recent exposure, other than the present surface layer, lies at a depth of 110-170 cm. A major stratigraphic sequence disturbance has therefore deposited the soils in their present positions.

  20. Integration of Design, Thermal, Structural, and Optical Analysis, Including Thermal Animation

    NASA Technical Reports Server (NTRS)

    Amundsen, Ruth M.

    1993-01-01

    In many industries there has recently been a concerted movement toward 'quality management' and the issue of how to accomplish work more efficiently. Part of this effort is focused on concurrent engineering; the idea of integrating the design and analysis processes so that they are not separate, sequential processes (often involving design rework due to analytical findings) but instead form an integrated system with smooth transfers of information. Presented herein are several specific examples of concurrent engineering methods being carried out at Langley Research Center (LaRC): integration of thermal, structural and optical analyses to predict changes in optical performance based on thermal and structural effects; integration of the CAD design process with thermal and structural analyses; and integration of analysis and presentation by animating the thermal response of a system as an active color map -- a highly effective visual indication of heat flow.