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. 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 Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS...

  3. 7 CFR 29.3542 - Rework.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Rework. 29.3542 Section 29.3542 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE COMMODITY STANDARDS AND STANDARD CONTAINER REGULATIONS TOBACCO INSPECTION Standards Official Standard...

  4. Column Grid Array Rework for High Reliability

    NASA Technical Reports Server (NTRS)

    Mehta, Atul C.; Bodie, Charles C.

    2008-01-01

    Due to requirements for reduced size and weight, use of grid array packages in space applications has become common place. To meet the requirement of high reliability and high number of I/Os, ceramic column grid array packages (CCGA) were selected for major electronic components used in next MARS Rover mission (specifically high density Field Programmable Gate Arrays). ABSTRACT The probability of removal and replacement of these devices on the actual flight printed wiring board assemblies is deemed to be very high because of last minute discoveries in final test which will dictate changes in the firmware. The questions and challenges presented to the manufacturing organizations engaged in the production of high reliability electronic assemblies are, Is the reliability of the PWBA adversely affected by rework (removal and replacement) of the CGA package? and How many times can we rework the same board without destroying a pad or degrading the lifetime of the assembly? To answer these questions, the most complex printed wiring board assembly used by the project was chosen to be used as the test vehicle, the PWB was modified to provide a daisy chain pattern, and a number of bare PWB s were acquired to this modified design. Non-functional 624 pin CGA packages with internal daisy chained matching the pattern on the PWB were procured. The combination of the modified PWB and the daisy chained packages enables continuity measurements of every soldered contact during subsequent testing and thermal cycling. Several test vehicles boards were assembled, reworked and then thermal cycled to assess the reliability of the solder joints and board material including pads and traces near the CGA. The details of rework process and results of thermal cycling are presented in this paper.

  5. 7 CFR 983.152 - Failed lots/rework procedure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 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 be shelled and the kernels reworked, sampled, and tested in the manner specified for an original lot...

  6. 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...

  7. 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.

  8. 66. BUILDING NO. 554, REWORK POWDER GRINDING ROUSE, PULVERIZING, WATER ...

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

    66. BUILDING NO. 554, REWORK POWDER GRINDING ROUSE, PULVERIZING, WATER DRY HOUSE, LOOKING NORTH (DEMOLITION IN PROGRESS). - Picatinny Arsenal, 500 Area, Powder Factory & Power House, State Route 15 near I-80, Dover, Morris County, NJ

  9. 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

  10. Lacie phase 1 Classification and Mensuration Subsystem (CAMS) rework experiment

    NASA Technical Reports Server (NTRS)

    Chhikara, R. S.; Hsu, E. M.; Liszcz, C. J.

    1976-01-01

    An experiment was designed to test the ability of the Classification and Mensuration Subsystem rework operations to improve wheat proportion estimates for segments that had been processed previously. Sites selected for the experiment included three in Kansas and three in Texas, with the remaining five distributed in Montana and North and South Dakota. The acquisition dates were selected to be representative of imagery available in actual operations. No more than one acquisition per biophase were used, and biophases were determined by actual crop calendars. All sites were worked by each of four Analyst-Interpreter/Data Processing Analyst Teams who reviewed the initial processing of each segment and accepted or reworked it for an estimate of the proportion of small grains in the segment. Classification results, acquisitions and classification errors and performance results between CAMS regular and ITS rework are tabulated.

  11. The Automated Aircraft Rework System (AARS): A system integration approach

    NASA Technical Reports Server (NTRS)

    Benoit, Michael J.

    1994-01-01

    The Mercer Engineering Research Center (MERC), under contract to the United States Air Force (USAF) since 1989, has been actively involved in providing the Warner Robins Air Logistics Center (WR-ALC) with a robotic workcell designed to perform rework automated defastening and hole location/transfer operations on F-15 wings. This paper describes the activities required to develop and implement this workcell, known as the Automated Aircraft Rework System (AARS). AARS is scheduled to be completely installed and in operation at WR-ALC by September 1994.

  12. 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

  13. 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

  14. 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

  15. 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...

  16. 7 CFR 983.52 - Failed lots/rework procedure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... 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...

  17. Reworking Exams To Teach Chemistry Content and Reinforce Student Learning

    NASA Astrophysics Data System (ADS)

    Risley, John M.

    2007-09-01

    One meaningful approach to demonstrate to students the value of reworking exams is to offer an incentive to do so. This paper describes the strategy and effects of offering partial credit to students who rework answers originally answered incorrectly on an exam. This has proved largely successful for the last 10 years in several classes at the collegiate level. In the grading scheme used, the average percentage of the regrade on the final course grade is approximately 2 3%. While the regrade makes little difference in the final course grade for the majority of students, students are very appreciative of the opportunity afforded them, and this often changes their perspective of the class and the morale to a more positive attitude. Teachers in high school and in other disciplines may benefit from this approach.

  18. Rework of flip chip bonded radiation pixel detectors

    NASA Astrophysics Data System (ADS)

    Vähänen, S.; Heikkinen, H.; Pohjonen, H.; Salonen, J.; Savolainen-Pulli, S.

    2008-06-01

    In this paper, some practical aspects of reworking flip chip hybridized pixel detectors are discussed. As flip chip technology has been advancing in terms of placement accuracy and reliability, large-area hybrid pixel detectors have been developed. The area requirements are usually fulfilled by placing several readout chips (ROCs) on single sensor chip. However, as the number of ROCs increases, the probability of failure in the hybridization process and the ROC operation also increases. Because high accuracy flip chip bonding takes time, a significant part of the price of a pixel detector comes from the flip chip assembly process itself. As large-area detector substrates are expensive, and many flip chip placements are required, the price of an assembled detector can become very high. In a typical case, there is just one bad ROC (out of several) on a faulty detector to be replaced. Considering the high price of pixel detectors and the fact that reworking faulty ROCs does not take much longer than the original placement, it is worthwhile to investigate the feasibility of a rework process.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. Trinity shoal: a reworked deltaic barrier on Louisiana continental shelf

    SciTech Connect

    Suter, J.R.; Penland, S.; Moslow, T.F.

    1985-02-01

    Abandonment and reworking of deltaic complexes of the Holocene Mississippi River have produced a series of sandy shoals on the muddy Louisiana continental shelf. Trinity shoal, one of these transgressive deposits, is located 30 km offshore of Atchafalaya Bay and the Point Au Fer-March Island shell reefs. Approximately 1000 km of high-resolution uniboom and 3.5 kHz subbottom-profile seismic data, taken in this area in 1983 and 1984, provide the data base for this study. Trinity shoal, associated with the abandoned Maringouin delta complex, is a lunate shore-parallel feature approximately 36 km long and 5-10 km wide. Relief on the shoal ranges from 2 to 3 m, and minimum water depths over the shoal vary from -5 to -2 m. The shoal sand body is from 5 to 7 m thick and is composed largely of parallel to low-angle clinoform reflectors. Several levels of buried fluvial channels, ranging in age from early Wisconsinian to Holocene, are associated with the shoal deposit. The occurrence of channel features within the shoal sand itself suggests the presence of tidal inlets, indicating a possible barrier-island origin for the shoal. The underlying deltaic sediments reach approximately 15 m in thickness and are made up of low-angle clinoform reflectors dipping to the southwest. Distributary, bay-fill, estuarine, and buried oyster-reef deposits can be recognized, making these similar to modern Atchafalaya delta deposits. Continued progradation of the Atchafalaya delta will probably result in burial of the Trinity shoal and Maringouin delta deposits by fine-grained sediments, giving these shoal deposits a high-preservation potential and creating an excellent stratigraphic trap.

  4. 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

  5. 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.

  6. 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.

  7. Hydraulic Response of Colorado River Rapids to a Reworking Flood

    NASA Astrophysics Data System (ADS)

    Magirl, C. S.; Webb, R. H.

    2005-12-01

    Rapids on the Colorado River in Grand Canyon are formed primarily by the accumulation of coarse sediment from tributaries. Frequent debris-flow events in these tributaries contribute alluvium that constricts the river, accelerates local fluid velocities, increases the water-surface fall through the rapids, and raises the water-surface elevation in the upper pool. In turn, large main-stem floods rework fresh debris-fan deposits by removing the smaller coarse sediment and repositioning the largest particles into a stable matrix on the bed of the rapid. While morphologic changes to debris-fan surfaces in response to main-stem floods are widely studied in Grand Canyon, relatively little is known of the specific changes to the hydraulics of a given rapid. The turbulent and dangerous nature of rapids makes in-situ measurements challenging. The current study, however, successfully measured hydraulics within the core of several rapids. These rapids had been steepened by debris-flow event within the previous seven years. Using a boat-mounted fathometer and acoustic doppler velocimeter (ADV), point measurements of water-surface elevation, bathymetry, three-dimensional velocity, and turbulence were made at a collection of moderately-sized rapids in Grand Canyon. The boat was a 19-foot J-snout with a 50-hp Mercury outboard motor capable of maneuvering to nearly any location within each rapid. A three-person crew onboard operated the instrumentation. Two crewmembers on shore operated a survey instrument to continually record the boat position on the river. To characterize hydraulic changes in response to a main-stem flood, repeat measurements were made at each site both before and after the 1,200 m3/s controlled flood of November 2004. While this exercise is only a first step in quantifying the fluid dynamics within a rapid, the hydraulic data collected offers a unique insight into the response of coarse-grained alluvial deposits to floods in fast-moving bedrock

  8. 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...

  9. 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

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

    NASA Astrophysics Data System (ADS)

    Yanites, Brian J.; Webb, Robert H.; Griffiths, Peter G.; Magirl, Christopher S.

    2006-11-01

    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.

  11. 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.

  12. 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.

  13. 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.

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

    NASA Astrophysics Data System (ADS)

    Lofgren, Donald L.; Hotton, Carol L.; Runkel, Anthony 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 they (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.

  15. 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.

  16. 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.

  17. 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.

  18. SEDIMENT REWORKING AND TRANSPORT IN EASTERN LAKE SUPERIOR: IN SITU RARE EARTH ELEMENT TRACER STUDIES

    EPA Science Inventory

    A rare earth element (REE) tracer pellet was deployed at the floor of the Ile Parisienne basin of eastern Lake Superior to measure representative sediment reworking and transport processes in the benthic boundary layer of the prnfundal Great Lakes. Samarium oxide, a high neutron-...

  19. Reworked calcareous nannofossils as ocean dynamic tracers: The Guadiana shelf case study (SW Iberia)

    NASA Astrophysics Data System (ADS)

    Ferreira, J.; Cachão, M.; González, R.

    2008-08-01

    For most micropalaeontological studies the presence of reworked specimens is usually considered as a disturbing factor where palaeoenvironmental or biostratigraphic interpretations are to be made. However, reworking of microfossils such as calcareous nannofossils can be used as an additional parameter in routine micropalaeontological work, providing useful information on erosion-transport processes acting on silty-clay sized particles deriving from areas surrounding the sedimentary basin under study. Most of the reworked calcareous nannofossils found in the Guadiana estuary water column (September 2001), adjacent shelf surface sediments, and a slope section of the Gulf of Cadiz were mainly of Upper Cretaceous age (Campanian to Maastrichtian), being dominated by Biscutum spp., Cribrosphaerella ehrenbergii, Prediscosphaera cretacea and Watznaueria barnesae. Since there are no Upper Cretaceous outcrops in the Guadiana's hydrographic basin or southern Portugal, the source of this material must be located elsewhere. Matrix breccias from mud volcanoes discovered in deeper water southern Portuguese and western Moroccan margins of the Gulf of Cadiz during the TTR-10 cruise in July/August 2000, as well as silty-clay sediments from its slopes, revealed similar calcareous nannofossil assemblages as those found on the Algarve continental shelf and inside the Guadiana's estuary. This may indicate that most of the reworked nannofossils have their origin in deepwater areas of the Gulf of Cadiz. The good preservation of most of the reworked Cretaceous nannofossils suggest that, shortly after resuspension, swift transport occurred from the source area to the coastal region of the Guadiana's river mouth, implicating a northward change in the deep Mediterranean water direction within the Gulf of Cadiz, which reaches the upper southwest Iberia slope. The Mediterranean Outflow is, therefore, the major mechanism accountable for transporting Upper Cretaceous material to the southwest

  20. 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

  1. Macrofaunal reworking activities and hydrocarbon redistribution in an experimental sediment system

    NASA Astrophysics Data System (ADS)

    Caradec, S.; Grossi, V.; Hulth, S.; Stora, G.; Gilbert, F.

    2004-09-01

    The influence of macrofaunal reworking activities on the redistribution of particle associated hydrocarbon compounds (HC) was experimentally investigated. Two distinct hydrocarbon mixtures adsorbed on montmorillonite particles (< 4 μm diameter) were added to the surface and deeper (2.5 cm) sediment layers. For comparison, luminophores (100-160 μm diameter) were added in the two deposit layers. At the start of the experiment, four macrobenthic species (the bivalve Abra nitida, the polychaete Scalibregma inflatum, and the echinoderms Amphiura filiformis and Echinocardium cordatum) were added to the sediment surface. The macrofauna added rapidly transferred HC from the surface sediment down to ˜5 cm depth by both continuous (biodiffusion) and non-continuous (biotransport) transport. Hydrocarbon compounds initially added to the deeper sediment layer were only subject to biodiffusion-like transport. Apparent biodiffusion coefficients ( Db) quantified by using a 1-D model were between 0.5 and 8.4×10 -3 cm 2 d -1, and biotransport coefficients ( r) ranged from 2.0 to 27.6×10 -3 d -1. Thus, the four species studied did not have the same effect on particle redistribution and, consequently, on HC repartition in the sediments. E. cordatum was the most efficient reworker. The present study demonstrated the importance of particle size selectivity by benthic fauna, and verified that macrofaunal reworking activities may redeposit sediment from deeper sediment layers on the sediment surface. Both processes have obvious implications for rates and pathways during organic matter mineralisation in marine sediments.

  2. 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.

  3. Benthic macrofauna and sediment reworking quantification in contrasted environments in the Thau Lagoon

    NASA Astrophysics Data System (ADS)

    Duport, E.; Gilbert, F.; Poggiale, J.-C.; Dedieu, K.; Rabouille, C.; Stora, G.

    2007-04-01

    As part of the Microbent-PNEC Program: "Biogeochemical processes at the water-sediment interface in eutrophicated environment", the aim of this work was to specifically investigate and quantify the relationships between macrobenthos and sediment reworking in the Thau Lagoon in order to provide information on the potential contaminant distribution and movements at the water-sediment interface. In order to achieve this, three cores were sampled at two stations (in the central part of the Thau Lagoon and near the shellfish farming zone) in the Thau Lagoon, in December 2001, April 2002, August 2002, January 2003 and May 2003. On the basis of quantification of macrobenthos and sediment reworking, evidence is provided of: (1) similar sediment mixing intensities for different species composition at the two stations; (2) the major role of functional bioturbation groups (e.g., biodiffusors and gallery-diffusors) modulated by seasonal variability on sediment mixing; (3) an increase of intensity in summer suggesting potentially different patterns of redistribution, bioaccumulation and chemical fate (e.g., speciation) of deposited contaminants.

  4. Remote Sensing of Debris Flow Deposition and Reworking by the Colorado River in Grand Canyon, Arizona

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

    Debris flows from 740 tributaries transport sediment ranging from clay to large (>3m) boulders into the Colorado River in Grand Canyon, Arizona. The resulting debris fans constrict the river to form rapids. Debris fans and rapids are in turn altered by the river, which entrains particles and transports them downstream. River regulation in Grand Canyon began with the closure of Glen Canyon Dam in 1963, and the geomorphic character of the debris fans has been adjusting to the change in flow regime ever since. Previous studies have suggested that the debris fans have and will continue to aggrade in response to reduced discharge on the Colorado River. In order to monitor and evaluate changes in debris fans, we created a time series of digital terrain models for two frequently aggraded debris fans (75-Mile Wash and Monument Creek) using ground surveys and photogrammetry acquired between 1984 and 2005. Two-dimensional photogrammetric analysis was extended to include years 1965 and 1973. Debris fan volume, surface area, and river constriction confirm that these two debris fans have recently aggraded owing to multiple debris flows that occurred from 1984 through 2003. Debris fan volumes increased at 75-Mile Wash by over 10,000 m3 and at Monument Creek by almost 8000 m3. Some of this aggradation is likely the effect of the preferential growth of small, non-resolvable plants and settling of sediments in topographical lows. Aggradation has also altered the geometry of the fans. Profiles of the surface models show maximum aggradation near the middle of the debris fan and a shift of surface morphology from a concave to a convex profile. Although small controlled-flood releases partially reworked both fans at the edges, reworking removed far less sediment than was added by debris-flow deposition. This is partly the result of the geography of debris-flow deposition, as material deposited in the middle of the fan can be reworked only by large floods that overtop the debris fans

  5. 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. PMID:26558182

  6. 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

  7. Maximising profits for an EPQ model with unreliable machine and rework of random defective items

    NASA Astrophysics Data System (ADS)

    Pal, Brojeswar; Sankar Sana, Shib; Chaudhuri, Kripasindhu

    2013-03-01

    This article deals with an economic production quantity (EPQ) model in an imperfect production system. The production system may undergo in 'out-of-control' state from 'in-control' state, after a certain time that follows a probability density function. The density function varies with reliability of the machinery system that may be controlled by new technologies, investing more costs. The defective items produced in 'out-of-control' state are reworked at a cost just after the regular production time. Occurrence of the 'out-of-control' state during or after regular production-run time is analysed and also graphically illustrated separately. Finally, an expected profit function regarding the inventory cost, unit production cost and selling price is maximised analytically. Sensitivity analysis of the model with respect to key parameters of the system is carried out. Two numerical examples are considered to test the model and one of them is illustrated graphically.

  8. [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

  9. 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.

  10. 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…

  11. 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

  12. 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.

  13. Long- and shortterm sediment yield by fluvial reworking of proglacial slopes in the upper Kaunertal

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

    Glacier retreat since the end of the Little Ice Age (LIA) has exposed, and is bound to expose, large quantities of glacial sediments to reworking by non-glacial processes such as slope wash, rill erosion, gullying and mass movements. According to the model of paraglacial response, proglacial areas experience a quick adaption with maximum rates of geomorphic activity and sediment flux shortly after deglaciation, followed by a period of slow stabilization. Our case study is situated in the Upper Kaunertal, Central Austrian Alps (64 km²), and forms part of the interdisciplinary research project PROSA (High-resolution measurement of morphodynamics in rapidly changing proglacial systems of the Alps). Using high-resolution surveying techniques such as airborne and terrestrial LiDAR and digital photogrammetry, we monitor surface changes effected by different geomorphic processes on steep moraines and drift-mantled slopes that have been deglaciated since the end of the LIA. Specifically, we investigate the combined effect of topography, hillslope-channel coupling and changing hydrometeorological conditions on sediment flux. Multitemporal airborne images dating back to 1953 are used to derive digital elevation models (DEMs) for long-term analysis of surface changes and the corresponding sediment transfer. Recent developments are measured by DEMs of Difference (DoD) based on multitemporal airborne (2006, July 2012, September 2012) and terrestrial (July 2010, September 2011, September 2012, September 2013, September 2014) LiDAR surveys. The analysis of more than 40 years of rainfall and runoff datat suggests that significant changes in these parameters have had an additional effect on the reworking of glacial sediment stores.

  14. Geothermal energy development in the eastern United States geothermal space heating - Naval Air Rework Facility, Norfolk, Virginia

    NASA Astrophysics Data System (ADS)

    Hill, F. K.; Henderson, R. W.

    1980-06-01

    The technical and economic feasibility of using geothermal energy for space heating the Naval Air Rework Facility (NARF) electronic integration hangar was evaluated. The warm water output from a single well was used in several modes: to heat via a floor radiation system or via heat pumps, with and without a ground water reservoir to store heat in off hours.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. Disturbance of benthic infauna by sediment-reworking activities of the lugworm Arenicola marina

    NASA Astrophysics Data System (ADS)

    Flach, E. C.

    The influence of the lugworm Arenicola marina on the abundance of other benthic species was studied in the westernmost part of the Wadden Sea. Small squares (1 m 2) within depopulated 144-m 2 plots were recolonized with various (naturally-occurring) lugworm densities (0-10-20-40-80 and 0-25-50-75-100 per m 2). These plots were sampled during the summer. Lugworms were found to have a strongly negative effect on the densities of C. volutator. At 0-density lugworms, the numbers of C. volutator were high. These were halved at 17 lugworms per m 2 ( i.e. the mean density on the tidal flats of the Dutch Wadden Sea), and were further reduced at higher lugworm densities ( e.g. 20% remained at 40 lugworms per m 2). Laboratory observations of Corophium behaviour in the presence of Arenicola suggest that sediment-reworking lugworms stimulate Corophium to emigrate. Effects of lugworms on other benthic species were also studied in the same way. Lugworms were found to have strongly negative effects on the juvenile densities of various worm and bivalve species ( Nereis diversicolor, Nephtys hombergii, Heteromastus filiformis, Scoloplos armiger, Pygospio elegans, Capitella capitata and Mya arenaria, Cerastoderma edule, Macoma balthica, Angulus tenuis, respectively).

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

    USGS Publications Warehouse

    Self-Trail J.M.; 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.

  1. Micro-trace fossils reveal pervasive reworking of Pliocene sapropels by low-oxygen-adapted benthic meiofauna

    NASA Astrophysics Data System (ADS)

    Löhr, S. C.; Kennedy, M. J.

    2015-03-01

    Animal burrowers leave an indelible signature on the sedimentary record in most marine environments, with the seeming exception of low-oxygen environments. In modern sedimentary settings, however, sub-millimetre-sized benthic animals (meiofauna) are adapted to low oxygen and even sulfidic conditions. Almost nothing is known about their impact on ancient marine sediments because they leave few recognizable traces. Here we show, in classic Pliocene-aged anoxic facies from the Mediterranean, the first reported trace fossil evidence of meiofaunal activity and its relation to changing oxygenation. A novel approach utilizing electron imaging of ion-polished samples shows that meiofauna pervasively reworked sediment under oxygen-depleted conditions that excluded macrofauna, fragmenting organic laminae and emplacing 15- to 70-μm-diameter faecal pellets without macroscopically influencing the fabric. The extent of reworking raises the question: how pervasively altered are other sediments presently assumed to lack animal influence and how far into the geological record does this influence extend?

  2. Barrier island evolution and reworking by inlet migration along the Mississippi-Alabama gulf coast

    SciTech Connect

    Rucker, J.B.; Snowden, J.O. )

    1990-09-01

    The five barrier islands along the Mississippi-Alabama coast are located 10 to 14 mi (16 to 23 km) offshore and separate Mississippi Sound from the Gulf of Mexico. The barrier islands in the chain are, from east to west: Dauphin Island, Petit Bois Island, Horn Island, Ship Island, and Cat Island. The islands are low sand bodies situated on a relatively broad Holocene sand platform that extends 70 mi (113 km) from Dauphin Island on the east to Cat Island on the west. The platform varies in thickness from 25 to 75 ft (7.6 to 23 m) and rests on Holocene marine clays or on Pleistocene sediments. The barrier island chain predates the St. Bernard lobe of the Mississippi delta complex, which began to prograde about 3,000 years ago, and continued until it was abandoned approximately 1,500 years ago. In contrast to the other islands, Cat Island at the western down-drift end of the Mississippi-Alabama barrier island chain is characterized by more than 12 prominent east west-oriented progradational linear ridges. The ridge system of Cat Island is interpreted as a relict of an earlier stage in the life cycle of the barrier platform when there was a more robust littoral drift system and an abundant sediment supply During the Pre-St. Bernard Delta period of vigorous sedimentation, all of the islands in the barrier chain probably exhibited progradational ridges similar to those now found only on Cat Island. Presently, only vestigial traces of these progradational features remain on the islands to the east of Cat Island. Unlike Cat Island, which has been protected and preserved by the St. Bernard Delta, the other barrier islands have been modified and reworked during the past 1,500 years by processes of island and tidal inlet migration, accompanied by a general weakening of the littoral drift and a reduction of the available sediment supply.

  3. 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

  4. 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

  5. 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

  6. Geochemical transition shown by Cretaceous granitoids in southeastern China: Implications for continental crustal reworking and growth

    NASA Astrophysics Data System (ADS)

    Chen, Jing-Yuan; Yang, Jin-Hui; Zhang, Ji-Heng; Sun, Jin-Feng

    2014-05-01

    -derived materials. The monzogranites have distinctly different zircon Hf and O isotope compositions from the enclaves, indicating that the parental magmas were mainly derived from ancient crust that interacted with underplated depleted mantle-derived magmas. The monzogranites have relatively high HREE contents, suggesting a garnet-free source (< 32 km), distinct from the Early Cretaceous adakite-like granites that were generated from a garnet-bearing source. Combined with previously published data, it is evident that Early Cretaceous adakite-like magmatic rocks (107-99 Ma) and associated mafic rocks (100-107 Ma) were widespread in SE China, indicating a crustal thickening event that was possibly induced by underplating of mantle-derived magma. Subsequently, between 99 and 87 Ma, crustal extension and lithospheric thinning induced the later widespread I-type granites with similar geochemical features to the Zaoshan pluton. A-type granites and syenites of this age are also present in SE China. The transition in geochemical and isotopic data, from enriched to depleted Hf isotope compositions as seen in the monzogranites, their enclaves and intrusive dolerites, suggest that depleted mantle-derived materials were involved in the generation of the monzogranites, further indicating continental crustal reworking and later crustal growth in SE China during the early Late Cretaceous.

  7. Lithotectonic framework and continental collisional reworking in the eastern part of the Sveconorwegian orogen

    NASA Astrophysics Data System (ADS)

    Andersson, Jenny; Möller, Charlotte; Stephens, Michael B.

    2013-04-01

    -to-the-ESE displacement followed by top-to-the-W extension. It forms a major structural, metamorphic and lithological terrane boundary. Lithotectonic units west thereof have been displaced out of their original tectonic context and cannot be directly linked to the remainder of the pre-Sveconorwegian Fennnoscandian Shield. Thus, considerable displacement must be accounted for. The Idefjorden terrane is the easternmost allochthonous belt of the orogen, directly overlying the Eastern Segment. It constitutes a patchwork of metamorphic sub-domains where high-grade complexes are juxtaposed against domains that show little or no imprint of Sveconorwegian reworking. Crustal thickening recorded by high-pressure granulite facies metamorphism (1.0-1.5 GPa and 700-740°C) has been dated at 1.05-1.02 Ga, i.e. at least 30 Ma earlier than the high-pressure metamorphism in the underlying Eastern Segment. The structural grain is orogen-parallel (in contrast to that in the Eastern Segment), with N-S-trending ductile fabrics, including fold axes, regional deformation zones and tectonic contacts of metamorphic complexes. The high- and medium-pressure metamorphism of the Eastern Segment (0.99-0.97 Ga) and the Idefjorden terrane (1.05-1.02 Ga) testifies to deep subduction of the Fennoscandian continental crust during the Sveconorwegian orogeny, broadly corresponding to the Rigolet and Ottawan phases of the Grenvillian orogeny, respectively. Both events are diagnostic of collisional orogeny, with syn-metamorphic intrusive activity limited to local dyke intrusion.

  8. 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

  9. Micro-trace fossils reveal pervasive reworking of Pliocene sapropels by low-oxygen-adapted benthic meiofauna.

    PubMed

    Löhr, S C; Kennedy, M J

    2015-01-01

    Animal burrowers leave an indelible signature on the sedimentary record in most marine environments, with the seeming exception of low-oxygen environments. In modern sedimentary settings, however, sub-millimetre-sized benthic animals (meiofauna) are adapted to low oxygen and even sulfidic conditions. Almost nothing is known about their impact on ancient marine sediments because they leave few recognizable traces. Here we show, in classic Pliocene-aged anoxic facies from the Mediterranean, the first reported trace fossil evidence of meiofaunal activity and its relation to changing oxygenation. A novel approach utilizing electron imaging of ion-polished samples shows that meiofauna pervasively reworked sediment under oxygen-depleted conditions that excluded macrofauna, fragmenting organic laminae and emplacing 15- to 70-μm-diameter faecal pellets without macroscopically influencing the fabric. The extent of reworking raises the question: how pervasively altered are other sediments presently assumed to lack animal influence and how far into the geological record does this influence extend? PMID:25762504

  10. Removal of highly crosslinked resists and hybrid polymers for single micro parts fabrication and nanoimprint stamp rework

    NASA Astrophysics Data System (ADS)

    Voigt, Anja; Engelke, Rainer; Ahrens, Gisela; Bullerjahn, Franziska; Schleunitz, Arne; Klein, Jan J.; Grützner, Gabi

    2014-03-01

    Thick photoresists, e.g. up to 1 mm layer thickness, are widely used for the manufacture of high aspect ratio microstructures, e.g. as mould for the fabrication of metallic micro parts. Such resists or materials exhibit high mechanical and chemical stability to non-deformably withstand a pattern transfer process, e.g. by electroplating. After the pattern transfer a solvent based removal is difficult or not possible in many cases. A selective mould removal - without the damage of electroplated metal structures - is required for the fabrication of single micro parts. As second application example UV curable and strongly crosslinkable inorganic-organic hybrid polymers such as OrmoComp ® and OrmoStamp ® are used in UV moulding. The cleaning and rework of these moulds or also of stamps for nanoimprint lithography (NIL) is a challenging task with increasing importance. The life time of an expensive master mould or stamp as well as of the replicated working stamps is important, and therefore the ability to rework such stamps without any defect or decreased resolution. Hence, we demonstrate the application of a plasma-assisted removal using the STP 2020 etching tool from MUEGGE [1] for remote dry etching of strongly crosslinked materials, i.e. the development of processes for the isotropical etching of highly crosslinked photoresists and hybrid polymer materials will be presented. In combination with this specific etching tool this technique shows a high potential to make plasma-assisted removal ready for industrial production.

  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. Discrimination of reworked pyroclastics from primary tephra-fall tuffs: a case study using kimberlites of Fort a la Corne, Saskatchewan, Canada

    NASA Astrophysics Data System (ADS)

    Leahy, Kevin

    Reworked volcaniclastics are traditionally discriminated from primary tephra-fall pyroclastics by an absence of features such as blanketing, juvenile lapilli, grain welding and poor sorting. Frequently, these features are difficult to identify, especially in small outcrops, ancient or altered successions, debris flows and surge deposits. Crystal-rich volcaniclastics, such as kimberlites, have a large proportion of coarse euhedral crystals, and abrasion leading to rounding can be recognised and classified with relative ease. A petrographic method of discriminating reworked material has been devised, based on the degree of grain roundness, and is illustrated using volcaniclastic kimberlite from Fort a la Corne, Saskatchewan, Canada. Petrographic thin sections of samples at regular intervals throughout the borehole core, and from a nearby crater-facies kimberlite, show that the percentages of rounded, subrounded and euhedral grains define two distinct groupings. The first group contains a higher percentage of euhedral grains and includes all the samples from the basal 4.8m of the 14.1-m-thick kimberlite section in borehole 004, and all of the crater facies tephra-fall tuffs. A second group contains more rounded, subrounded and fragmental grains and includes all the data from the upper 6.3m, which are interpreted as reworked strata. Thus, point counting concurs with hand-sample interpretation and may be used as a verification tool in discriminating reworked pyroclastic sands from primary tephra-fall tuffs.

  13. 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.

  14. 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

  15. History of Laurentide meltwater flow to the Gulf of Mexico during the last deglaciation, as revealed by reworked calcareous nannofossils

    NASA Astrophysics Data System (ADS)

    Marchitto, Thomas M.; Wei, Kuo-Yen

    1995-09-01

    The history of meltwater flow from the Laurentide Ice Sheet to the Gulf of Mexico during the last deglaciation, which holds possible implications for the cause of the Younger Dryas cold episode, is not well understood. We propose a new chronology based on using the percentage of reworked calcareous nannofossils in Orca Basin sediments as a proxy for erosion. The period of greatest meltwater flow to the gulf was between 12.7 and 12.1 ka (during the Bølling warm interval), and flow remained high until the beginning of the Younger Dryas cold episode at 11.3 ka; this corresponds to meltwater pulse IA. A sharp meltwater decrease at 12.2 ka may represent the Older Dryas glacial readvance. Little or no meltwater is inferred to have flowed to the gulf from ˜10 to 9 ka, which is the time of the second major meltwater pulse, IB. Therefore, meltwater must have been permanently diverted away from the Gulf of Mexico at the beginning of the Younger Dryas.

  16. 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…

  17. 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)

  18. 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.

  19. 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

  20. 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

  1. Organic-looking' carbon and nitrogen isotope compositions in mantle derived diamondites: Mantle fractionation vs. re-worked crustal organics?

    NASA Astrophysics Data System (ADS)

    Mikhail, Sami; Dubosi, Gabor; Verchovsky, Sahsa; Jones, Adrian; Kurat, Gero

    2010-05-01

    composition (5). There are two ways in which these diamondites could have been formed based on their carbon and nitrogen isotope compositions: (1) Reworking (either recycling via remobilisation of the lower lithosphere or subduction) could have provided the carbon and nitrogen which have preserved their ‘organic-like' signatures; or (2) the loss of 13C rich oxidised carbon from the system by carbonisation of olivine (explaining the lack of olivine inclusions in diamondites) during diamondite crystallisation would result in increasing of the N/C ratio (≈ N ppm) and a drives the carbon isotopic value lighter. The small increase in nitrogen isotopes to more heavy values (at this early stage) is thought to be a function of a small loss of nitrogen from the substrate. This is followed by continuous diamond formation where oxidised carbon is lost via silicate carbonisation and the formation of carbonates (13C enrichment in the source) and nitrogen is removed from the source by being partitioned into the crystallising diamonds (15N enrichment in the source). During such progressive crystallisation of diamondites the carbon and nitrogen isotope compositions can be fractionated to extremely ‘organic-like' values. We find that both models warrant sufficient discussion for this data set. 1.G. Dobosi, G. Kurat, Mineralogy and Petrology 76, 21 (2002). 2.G. Kurat, G. Dobosi, Mineralogy and Petrology 69, 143 (2000). 3.R. Burgess, L. H. Johnson, D. P. Mattey, J. W. Harris, G. Turner, Chemical Geology 146, 205 (1998). 4.M. Honda, D. Phillips, J. W. Harris, I. Yatsevich, Chemical Geology 203, 347 (2004). 5.T. Maruoka, G. Kurat, G. Dobosi, C. Koeberl, Geochimica Et Cosmochimica Acta 68, 1635 (2004). 6.D. A. Shelkov, A. B. Verchovsky, H. J. Milledge, C. T. Pillinger, Chemical Geology 149, 109 (1998). 7.C. Gautheron, P. Cartigny, M. Moreira, J. W. Harris, C. J. Allègre, Earth and Planetary Science Letters 240, 559 (2005). 8.D. E. Jacob, K. S. Viljoen, N. Grassineau, E. Jagoutz, Science 289

  2. 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

  3. 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

  4. Structural and seismic data on a new branch of the North Anatolian Fault: A reworked Tertiary thrust fault in northwestern Turkey

    NASA Astrophysics Data System (ADS)

    Aylan, E.; Akbayram, K.; Imren, C.

    2012-04-01

    The North Anatolian Fault (NAF) is an over 1200 km long dextral strike-slip fault in the eastern Mediterranean. The North Anatolian Fault (NAF) and its related branches together make up the North Anatolian Shear Zone (NASZ). The NASZ has two well known active segments in Adapazarı - Sakarya - Bolu region, northwestern Turkey. We provide new structural, stratigraphical and seismic data showing that a previously unknown third segment also exists and created as a result of reworking of Cenozoic thrust faults by the recent deformation of the NAF, in northwest Turkey. Our study area is within Sakarya Basin which consists of ~6 km thick Jurassic - Lower Tertiary sediments, located between the main branch of the NAF in the north and a Mesozoic suture zone in the south. During Tertiary the units in the Sakarya Basin is folded and faulted as a result of north - south shortening. Interestingly one of these thrust faults, so called Pirler Fault, is a deep angle fault dipping 70° south. Later regional analysis on the Pirler Fault shows that this fault is approximately 200 km long, extended southwest to northeast, from the southern border of a Quaternary basin (Gölpazarı Basin of Sakarya city) to the main segment of the NAF (Gerede region of Bolu city). Distribution of the epicenters of recent earthquakes also shows that there is much activity going on the Pirler Fault, generating Mw = 2 - 4 earthquakes.

  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. A 2.5 G.a. reworked sialic crust: Rb-Sr ages and isotopic geochemistry of late archaean volcanic and plutonic rocks from E. Finland

    NASA Astrophysics Data System (ADS)

    Martin, Hervé; Querré, Guirec

    1984-03-01

    In east-central Finland, Archaean terrains present three main lithologic units: a) gneissic basement, emplaced from 2.86 G.a. to 2.62 G.a., b) greenstone belt (2.65 G.a.) and c) calc-alkaline magmatism (2.50 G.a. to 2.40 G.a). Twenty three rocks of the calc-alkaline suite have been chosen for geochronologic and Rb-Sr isotopic studies. These rocks are subdivided into three groups: 1) acid volcanics from Luoma, 2) augen gneiss from Arola, and 3) post kinematik pink leucogranite from Arola. The 2.50±0.10 G.a. age of the Luoma volcanics indicates that they represent the upper part of a greenstone belt composed of a single sequence of volcanic rocks. The ages, initial 87Sr/86Sr (ISr) and major element compositions of the augen gneisses of Arola and Suomussalmi indicate that these rocks are the plutonic equivalents of the Luoma acid volcanics. The Arola pink leucogranite marks the terminal phase of Archaean magmatic activity (from 2.86 G.a. to 2.41 G.a.). This was followed by at least 0.40 G.a. of quiescence. The ISr and major element compositions suggest that the genesis of the calc-alkaline magmatic rocks involved crustal materials, but all their geochemical features cannot be explained without the participation of mafic greenstone belt materials. The first crustal components had low I and low K2O/ Na2O ratios while the younger ones (calc-alkaline magmas) had medium to high ISr and high K2O/Na2O ratios. Thus the petrogenetic processes have changed with time from ensimatic to ensialic, implying major reworking of preexisting crustal materials. This evolution leads to the accretion of the continental crust from the mantle.

  8. 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.

  9. 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

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. Archaean and Palaeoproterozoic gneisses reworked during a Neoproterozoic (Pan-African) high-grade event in the Mozambique belt of East Africa: Structural relationships and zircon ages from the Kidatu area, central Tanzania

    NASA Astrophysics Data System (ADS)

    Vogt, M.; Kröner, A.; Poller, U.; Sommer, H.; Muhongo, S.; Wingate, M. T. D.

    2006-06-01

    crustal remnants that were reworked during the Neoproterozoic Pan-African orogeny.

  15. National Emission Standards for Hazardous Air Pollutants (NESHAP), Aerospace Manufacturing and Rework Facilities Rule: Operational and economic impacts at U.S. Air Force Air Combat Command (ACC) installations

    SciTech Connect

    Moore, T.C.; Durand, G.P.; Senn, M.R.

    1997-12-31

    The recently promulgated Aerospace Manufacturing and Rework Facilities National Emission Standards for Hazardous Air Pollutants (NESHAP), found in 40 CFR 63 Subpart GG, is expected to significantly impact operations at US Air Force (USAF) bases. At the request of the USAF`s Air Combat Command (ACC), Armstrong Laboratory`s Air Quality Branch performed a compliance assessment for all ACC bases in the summer of 1996 to determine more clearly the rule`s impact on operations at these bases. This assessment included first determining the base`s current major source standing for hazardous air pollutants (HAPs), as defined by Title III of the Clean Air Act. In addition, this assessment ascertained the volatile organic compound (VOC) and HAP content levels for both the primers and topcoats currently being used in base aircraft maintenance operations. Finally, the survey determined the type of solvents used in cleaning aerospace parts, as well as the types of control equipment currently in place at each base. The results of the compliance assessment suggest a prohibitive impact on operations at ACC bases, including total potential direct monetary costs of up to $25M. Additional personnel requirements will be incurred as a result of increased monitoring, recordkeeping, and reporting. Substitution of low VOC/HAP primers and topcoats and/or redefining maintenance operations to meet touch-up and repair definitions are discussed as possible alternatives, but the results indicate the best solution is to reassess each ACC base`s status as a major source for HAPs, with the intent of having each base defined as a minor source for HAPs. In this manner, the ACC bases can avoid the Aerospace NESHAP compliance requirements altogether, at substantial savings to the US Air Force.

  16. 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.

  17. Lesson Plans Are Being Reworked To Stretch Construction Dollars.

    ERIC Educational Resources Information Center

    Rubin, Debra K.; Rosta, Paul; Gonchar, Joann; Illia, Tony

    2002-01-01

    Discusses the search by school systems and construction professionals for new efficiencies in the face of economic pressures. Some are shrinking or stretching out construction programs and demanding better economies. Others are seeking new financial partners and non-traditional funding methods, or deciding that creating new school space does not…

  18. 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.)

  19. 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.

  20. Archean evolution of the Leo Rise and its Eburnean reworking

    NASA Astrophysics Data System (ADS)

    Thiéblemont, Denis; Goujou, Jean Christian; Egal, Emmanuel; Cocherie, Alain; Delor, Claude; Lafon, Jean Michel; Fanning, C. Mark

    2004-06-01

    Recent geological mapping in southeastern Guinea, supported by zircon dating, has called into question traditional understanding concerning the evolution of the Leo Rise. Gneiss dated at about 3540 Ma appears to constitute the earliest evidence for continental accretion within the Leo Rise. The existence of a Leonian depositional cycle at about 3000 Ma is confirmed, marked by volcanic and sedimentary rocks that can be correlated with the Loko Group in Sierra Leone. The span of ages (3244-3050 Ma) suggests that the Leonian cycle comprises different episodes whose respective chronology is as yet uncertain. Clearly distinct from the Leonian cycle, the Liberian cycle (˜2900-2800 Ma) is represented in Guinea by granite and migmatite (˜2910-2800 Ma), reflecting remobilization of the ancient Archean basement and deformation of the Leonian rocks; no deposition is associated with this cycle. After the Liberian, the Nimba and Simandou successions, containing Liberian detrital zircons, are assigned to the Birimian (˜2200-2000 Ma). Finally, Eburnean tectonism caused intense deformation of the Archean craton, accompanied by high-grade metamorphism and the intrusion of granite and syenite with ages between 2080 and 2020 Ma. The evolution of the Kénéma-Man domain, attributed to the cumulated effect of the Leonian and Liberian cycles, is thus in part Eburnean. We can suppose, therefore, that the NNE-SSW-trending structures attributed to the Liberian in Sierra Leone are, in fact, Eburnean. The Kambui Supergroup, also affected by this tectonism, should thus be assigned to the Birimian rather than the Liberian, which would explain its similarities with the Nimba and Simandou successions.

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

    USGS Publications Warehouse

    Horton, J.W., Jr.; Aleinikoff, J.N.; Kunk, M.J.; Gohn, G.S.; Edwards, L.E.; Self-Trail J.M.; 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.

  2. Reworking the science curriculum: A case study in the interdependence between introductory biology and multiculturalism

    NASA Astrophysics Data System (ADS)

    Persell, Roger

    1994-12-01

    Multiculturalism has emerged as the major influence in revising science curricula and teaching, yet misunderstanding about the history and theoretical underpinnings of multiculturalism has made the separation of political and education reform contentious and difficult. Within the context of a new college-wide pluralism and diversity requirement, a large introductory biology course at Hunter College of the City University of New York is now the testing ground for an interdependent model of multicultural education. The implications for multiculturalism, science pedagogy, and the pivotal role of introductory courses are discussed.

  3. ENVIRONMENTAL RESEARCH BRIEF: WASTE MINIMIZATION ASSESSMENT FOR A MANUFACTURER OF NEW AND REWORKED ROTOGRAVURE PRINTING CYLINDERS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. aste Minimization Assessment Centers (WMACs) were established at selected un...

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. 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,…

  9. 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…

  10. Managing Spaces: (Re)working Relations of Strategy and Spatiality in Vocational Education and Training

    ERIC Educational Resources Information Center

    Mulcahy, Dianne

    2007-01-01

    The adoption of a more "open" national training market in vocational education and training (VET) in Australia has led to considerable changes in VET organizations and considerable challenges for VET managers. Recent research has established the critical role that 'strategy' plays in leading and managing these organizations and the significance of…

  11. Implementation of Title V requirements at an aerospace manufacturing and rework facility

    SciTech Connect

    Stark, W.T.; Ayers, M.F.; Reed, J.T.

    1998-12-31

    The Clean Air Act Amendments of 1990 forced many sources to apply for permits and be subject to both state and federal oversight through the operating permit programs implemented under Title V. In order to comply with new permit provisions, many sources were forced to develop and implement complex programs that would both ensure compliance and allow maximum operating flexibility. Although no material tracking or reporting system existed before the Learjet facility became subject to Title V, careful planning and use of the proper tools and procedures allowed the implementation of a facility-wide data management and compliance reporting system that is not process dependent, allows maximum operating flexibility, and adds relatively few inconveniences to operations personnel. Also, as new requirements become effective in the coming years, the flexibility of the system allows it to be easily modified by facility personnel.

  12. 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.

  13. Chinese-Thai Transmigrants: Reworking Identities and Gender Relations in Thailand and the United States.

    ERIC Educational Resources Information Center

    Bao, Jiemin

    1999-01-01

    Analyzes how Chinese-Thai transmigrants are shaped by social categories and simultaneously shape themselves, first in Thailand and then after migration to the United States. These immigrants cannot be understood as a singular essence. They want to be Chinese, Thai, and American simultaneously. (SLD)

  14. 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…

  15. Reworked old crust-derived shoshonitic magma: The Guarany pluton, Northeastern Brazil

    NASA Astrophysics Data System (ADS)

    Ferreira, Valderez P.; Sial, Alcides N.; Pimentel, Marcio M.; Armstrong, Richard; Guimarães, Ignez P.; da Silva Filho, Adejardo F.; de Lima, Mariucha Maria C.; da Silva, Thyego R.

    2015-09-01

    The 572 Ma Guarany stock consists of magmatic epidote-bearing hornblende monzodiorite to biotite granite that intruded Paleoproterozoic orthogneisses about 10 km inland from the coast in northeastern Brazil. Co-magmatic diorite enclaves and dikes are abundant throughout the pluton. The monzodiorite-granite pluton and diorite enclaves are shoshonitic and display continuous trends in variation diagrams. They display chemical and isotopic characteristics of crustal melts, such as enrichment in incompatible elements, high back-calculated initial 87Sr/86Sr ratios (avg. 0.71253), negative εNd (0.57Ga) values (avg. - 14.58), as well as high and variable (+ 9.1 to + 11.1‰VSMOW) δ18O (zircon) values. Correlations between O-isotope and whole-rock silica contents, as well as initial 87Sr/86Sr ratios with 1/Sr concentrations, suggest hybridization of a lower continental crustal melt with more felsic crustal rocks, concomitant with fractional crystallization. Amphibole chemistry and whole rock Zr, TiO2 and P2O5 contents suggest magma solidification at a pressure ~ 7 kbar and near liquidus temperature ~ 900 °C. The parental magma was likely formed by partial melting of old (tDM = 2.0 Ga) amphibolitic lower continental crustal rocks, in a post-collisional setting, probably triggered by underplating of mantle-derived mafic magma during the period of relaxation after collision.

  16. CEBAF energy upgrade program including re-work of CEBAF cavities

    SciTech Connect

    Joseph Preble

    2008-02-12

    The Thomas Jefferson National Accelerator Facility, Jefferson Lab, is planning an upgrade of the CEBAF accelerator from a maximum energy of 6 GeV to 12 GeV and from 3 to 4 experimental halls. This paper will discuss the plans for upgrading the energy of the machine which requires improvements of the existing Super Conducting Radio Frequency (SRF) cryomodules and the additions of ten newly designed high performance SRF cryomodules.

  17. 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…

  18. Emplacement and reworking of the Marampa Group allothchon, northwestern Sierra Leone, West Africa

    NASA Astrophysics Data System (ADS)

    Latiff, R. S. A.; Andrews, J. R.; Wright, L. I.

    1997-10-01

    The structural evolution and relative age of the Precambrian Marampa Group, a 60 km wide north-northwest trending fold thrust belt is described in detail. The Marampa Group is shown to be unconformably overlain by the Rokel River Group which lies immediately to the east and is separated by a major crustal shear zone from gneisses and amphibolites of the Kasila Group to the west. Previous workers have interpreted the fold thrust belt as a klippe of the adjacent Kasila Group derived from the west or as an autochthonous volcano-sedimentary deposit engulfed by granitic. basement. Ages ranging from 500 to > 2700 Ma have been suggested. Evidence is presented to show that the important deformation of the Marampa Group clearly predates the deposition of the Rokel River Group and must represent a significant earlier orogenic event. Constraints on the relationship of this older deformation to the 2700-2750 Ma deformation of the Kasila Group are discussed. The earliest structures consist of flat lying thrusts which transported Marampa Group metasediments, with or without their basal metavolcanic formation, eastward from their source basin over the basin margin and onto a flanking heterogeneously deformed older granitic gneiss basement. Subsequent intrusion of megacrystic, now porphiyroclastic granites was followed by a major period of crustal extension during which sediments and volcanics of the Rokel River Group were deposited in rift basins. Renewed east-west crustal shortening ascribed to the Pan-African event inverted earlier extensional structures thrusting the Rokel River Group westward over -the Marampa Group and leading to local facing confrontations where east dipping faults were reactivated. The relationship of the Marampa Group to the greenstone belts of Guinea, Liberia and Sierra Leone remains unresolved.

  19. 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…

  20. Burning peat and reworking loess contribute to the formation and evolution of a large Carolina-bay basin

    NASA Astrophysics Data System (ADS)

    Rodriguez, Antonio B.; Waters, Matthew N.; Piehler, Michael F.

    2012-01-01

    Carolina bays are nearly ubiquitous along ~ 1300 km of the North American Atlantic Coastal Plain, but relatively few bays have been examined in detail, making their formation and evolution a topic of controversy. The Lake Mattamuskeet basin, eastern North Carolina, USA, is a conglomeration of multiple Carolina bays that form a > 162 km2 lake. The eastern shoreline of the lake is made up of a 2.9-km-wide plain of parabolic ridges that recorded rapid shoreface progradation. The lower shoreface deposit contains abundant charcoal beds and laminae dated 6465-6863 cal yr BP, corresponding with initiation of a lacustrine environment in the eastern part of the lake. A core from the western part of the lake sampled a 1541-1633 cal yr BP charcoal bed at the base of the lacustrine unit, indicating formation of this part of the basin postdates the eastern basin. Lake Mattamuskeet has no relationship to the Younger Dryas or a linked impact event because rim accretion significantly postdates 12,000 cal yr BP. The shoreline progradation, and association of charcoal beds with the oldest lake sediment in both main parts of the basin, suggest that fire and subsequent hydrodynamic processes were associated with initial formation of these Carolina bays.

  1. 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.

  2. WASTE MINIMIZATION ASSESSMENT FOR A MANUFACTURER OF NEW AND REWORKED ROTOGRAVURE PRINTING CYLINDERS (EPA/600/S-95/005)

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. Waste Minimization Assessment Centers (WMACs) were established at selected u...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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…

  8. 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.

  9. 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.

  10. Geothermal energy development in the eastern United States: technical assistance report no. 5. Geothermal space heating-naval air rework facility, Norfolk, Virginia. [Aircraft hangers

    SciTech Connect

    Hill, F.K.; Henderson, R.W.

    1980-06-01

    The electronic integration hangar, designated LP-167, was selected for study, as it was a single-story building with a large floor area. Because of the high ceiling and the sliding doors necessary to admit aircraft, the heat loss rate, based on floor area, was about twice that of commercial buildings. It was furnished with an oil-fired hot water heating system capable of high thermal output to meet heating requirements in the coldest weather. On the basis of the known characteristics of geothermal sources for the Atlantic Coastal Plain, and wells drilled and assayed in the Norfolk area, a reasonable estimate of the parameters of a well drilled at NARF was made. This included a low temperature output from the well of only 107/sup 0/F, so that direct transfer of warm water between the wellhead heat exchanger (HX) and the hot water radiating system in the building was not practical. Four design options are explored and calculations are presented on each one.

  11. 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.

  12. 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.

  13. Work First. How To Implement an Employment-Focused Approach to Welfare Reform. A How-to Guide. ReWORKing Welfare. Technical Assistance for States and Localities.

    ERIC Educational Resources Information Center

    Brown, Amy

    This guide, which is intended for planners, administrators, and staff involved in state and local welfare reform efforts, summarizes information about the "work first" approach to welfare reform that was gained from comprehensive evaluations of work first programs and discussions with program managers, practitioners, and participants. The…

  14. The Bir Safsaf Precambrian inlier of South West Egypt revisited. A model for ~ 1.5 Ga T DM late Pan-African granite generation by crustal reworking

    NASA Astrophysics Data System (ADS)

    Bea, F.; Montero, P.; Anbar, M. Abu; Molina, J. F.; Scarrow, J. H.

    2011-08-01

    Bir Safsaf is one of the four Precambrian inliers of the southern Egyptian Western Desert; it is located midway between the juvenile crust of the Arabian-Nubian Shield and the Archean terranes of Gebel Kamil, near the Libyan border. Contrary to previous belief, Bir Safsaf is exclusively composed of late Pan-African granitoids, with U/Pb SHRIMP ages between 627 Ma and 595 Ma. The presence of pre-Pan-African materials is limited to scarce inherited zircons with ~ 2.1 Ga and ~ 2.7 Ga, ages that are well-represented in the pre-Pan-African terranes of the neighboring Gebel Kamil inlier. Early Pan-African inherited zircons with ages of ~ 640-650 Ma and ~ 750 Ma are also found. The granitoids of Bir Safsaf show a large geochemical variability, with an overall composition similar to subduction-related granites, but they lack the inter-elemental correlations characteristic of magmatic differentiation, magma mixing or hybridization. This chemically heterogeneous set of granitoids has, nonetheless, nearly uniform initial 87Sr/ 86Sr and 143Nd/ 144Nd, and a ~ 1.5 Ga Nd model age (T DM) despite no new crust being formed at that time in northeast Africa. To reconcile the large chemical variability, the isotopic homogeneity, and the "mixed" Nd model age, we propose that these granitoids were derived from a lithologically heterogeneous pre-Pan African source that, prior to melting, was thoroughly homogenized with respect to Sr and Nd isotopes by convective metasomatism caused by juvenile hydrothermal fluids probably released from a subduction zone.

  15. 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…

  16. 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.

  17. 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.

  18. Re-work: a new Japanese support system for reinstatement.

    PubMed

    Soeda, Shuji

    2016-09-01

    Re-work is a new treatment technique that follows the conventional Japanese approach, which includes rest and pharmacotherapy. The aim of re-work is to prevent repeated sick leave by helping individuals reflect on the reasons behind the sick leave and improve stress-related coping skills. Re-work participants prepare in an environment similar to their workplaces at a medical institution or a specialised public facility for several months before returning to work. As re-work is undertaken via group work, this has benefits beyond those which can be achieved by an individual alone. The reinstatement effects of re-work are now starting to be verified. Issues of interest for re-work include its unified concept-based programme, and the need to further verify its clinical efficacy and cost-effectiveness. PMID:26677732

  19. 40 CFR 63.7985 - Am I subject to the requirements in this subpart?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CFR part 63. Affiliated operations include, but are not limited to, mixing or dissolving of coating... Rework Facilities), KK (National Emission Standards for the Printing and Publishing Industry),...

  20. 40 CFR 63.7985 - Am I subject to the requirements in this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CFR part 63. Affiliated operations include, but are not limited to, mixing or dissolving of coating... Rework Facilities), KK (National Emission Standards for the Printing and Publishing Industry),...

  1. 75 FR 35454 - Agency Information Collection Activities; Submission to OMB for Review and Approval; Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-22

    ... Request; Aerospace Manufacturing and Rework Industry Information Request Questionnaire; EPA ICR Number... the facilities and their basic design and operating features, quantity of air emissions,...

  2. 78 FR 68054 - Information Collection Request Submitted to OMB for Review and Approval; Comment Request; NESHAP...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    .... Public comments were previously requested via the Federal Register (78 FR 33409), on June 4, 2013 during... for Aerospace Manufacturing and Rework Facilities (Renewal) AGENCY: Environmental Protection Agency... collection request (ICR), ``NESHAP for Aerospace Manufacturing and Rework Facilities (40 CFR Part 63,...

  3. 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

  4. 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.

  5. 78 FR 49996 - Pipeline Safety: Periodic Updates of Regulatory References to Technical Standards and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-16

    ... diameter (e.g., no rework material is allowed for pipe two inches Iron Pipe Size (IPS) and below in diameter and the requirements in ASTM D2513-09a, section 4.2 would be acceptable for pipe larger than two... rework. Smaller diameter pipe (two-inch IPS and less), however, has proven to be more susceptible to...

  6. 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…

  7. 75 FR 82333 - Airworthiness Directives; McDonnell Douglas Corporation Model DC-10-10, DC-10-10F, and MD-10-10F...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-30

    ... Policies and Procedures (44 FR 11034, February 26, 1979), and 3. Will not have a significant economic... crack and structural reinforcement. For permanently and temporarily repaired areas, the service rework... crack and structural reinforcement. For permanently repaired areas, the service rework drawing...

  8. 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.

  9. 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.

  10. 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.

  11. BLDG F101, FRONT ELEVATION Naval Magazine Lualualei, Headquarters Branch, ...

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

    BLDG F101, FRONT ELEVATION - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhall Building Types, Eighteenth Street & Fence Road near Hastings Street intersection, Pearl City, Honolulu County, HI

  12. BLDG 8, VIEW OF NE SIDE LOOKING THRU SE DRIVE ...

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

    BLDG 8, VIEW OF NE SIDE LOOKING THRU SE DRIVE THROUGH. - Naval Magazine Lualualei, West Loch Branch, Ammo Rework Building, North of Fourth Street near intersection with B Avenue, Pearl City, Honolulu County, HI

  13. BLDG A250, ACCESS DRIVE ON EAST SIDE FROM SOUTH ENTRY. ...

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

    BLDG A250, ACCESS DRIVE ON EAST SIDE FROM SOUTH ENTRY. - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhaul Building, Forty-fourth & Iwo Jima Streets intersection, Pearl City, Honolulu County, HI

  14. BLDG 250, WEST END ENTRY AND NORTH SIDE OF BLDG. ...

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

    BLDG 250, WEST END ENTRY AND NORTH SIDE OF BLDG. - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhaul Building, Forty-second Street between Jamestown & Iwo Jima Streets, Pearl City, Honolulu County, HI

  15. BLDG 250, FROM BERM/BLAST WALL ON NORTH SIDE OF BLDG. ...

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

    BLDG 250, FROM BERM/BLAST WALL ON NORTH SIDE OF BLDG. - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhaul Building, Forty-second Street between Jamestown & Iwo Jima Streets, Pearl City, Honolulu County, HI

  16. BLDG F102, INTERIOR VIEW. Naval Magazine Lualualei, Headquarters Branch, ...

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

    BLDG F102, INTERIOR VIEW. - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhall Building Types, Eighteenth Street & Fence Road near Hastings Street intersection, Pearl City, Honolulu County, HI

  17. BLDG F101, NORTH END AND REAR (EAST) SIDE. Naval ...

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

    BLDG F101, NORTH END AND REAR (EAST) SIDE. - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhall Building Types, Eighteenth Street & Fence Road near Hastings Street intersection, Pearl City, Honolulu County, HI

  18. BLDG F101, FRONT ELEVATION W/POLE Naval Magazine Lualualei, Headquarters ...

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

    BLDG F101, FRONT ELEVATION W/POLE - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhall Building Types, Eighteenth Street & Fence Road near Hastings Street intersection, Pearl City, Honolulu County, HI

  19. BLDG 250, OVERVIEW SHOWING BERMS AND BLAST WALLS. Naval ...

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

    BLDG 250, OVERVIEW SHOWING BERMS AND BLAST WALLS. - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhaul Building, Forty-second Street between Jamestown & Iwo Jima Streets, Pearl City, Honolulu County, HI

  20. BLDG A250, NORTH SIDE SHOWING DOUBLE ACCESS Naval Magazine ...

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

    BLDG A250, NORTH SIDE SHOWING DOUBLE ACCESS - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhaul Building, Forty-fourth & Iwo Jima Streets intersection, Pearl City, Honolulu County, HI

  1. BLDG F101, SOUTH END AND FRONT (WEST). F102 IN BACKGROUND. ...

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

    BLDG F101, SOUTH END AND FRONT (WEST). F102 IN BACKGROUND. - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhall Building Types, Eighteenth Street & Fence Road near Hastings Street intersection, Pearl City, Honolulu County, HI

  2. BLDG 250, WEST SIDE ENTRY W/POLE. Naval Magazine Lualualei, ...

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

    BLDG 250, WEST SIDE ENTRY W/POLE. - Naval Magazine Lualualei, Headquarters Branch, Ammo Rework-Overhaul Building, Forty-second Street between Jamestown & Iwo Jima Streets, Pearl City, Honolulu County, HI

  3. Replacing ODCs in a Critical Hand Cleaning Manual Electronics Assembly Operation

    NASA Technical Reports Server (NTRS)

    Bonner, J. K.; Walton, Sharon

    1997-01-01

    The manufacture of high reliability electronics assemblies for spacecraft and ground support equipment still often involves manual assembly processes. In addition, rework and repair of critical assemblies aslo often entails manual assembly processes.

  4. 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...

  5. Lightweight Tool Grinds Back-Side Weld Beads

    NASA Technical Reports Server (NTRS)

    Gallagher, Robert L.

    1994-01-01

    Air-powered grinder enables high-quality rework of welds. Tool removes excess material from back side of weld in preparation for reworking. Used on workpiece while workpiece still mounted in welding fixture or welding machine. Then rewelded in original position, so full process control maintained. Used for grinding material in spaces to which access limited, such as in pressure vessels and in hulls of ships. Also used to grind materials other than metals.

  6. 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.

  7. 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.

  8. Fossils out of sequence: Computer simulations and strategies for dealing with stratigraphic disorder

    SciTech Connect

    Cutler, A.H.; Flessa, K.W. )

    1990-06-01

    Microstratigraphic resolution is limited by vertical mixing and reworking of fossils. Stratigraphic disorder is the degree to which fossils within a stratigraphic sequence are not in proper chronological order. Stratigraphic disorder arises through in situ vertical mixing of fossils and reworking of older fossils into younger deposits. The authors simulated the effects of mixing and reworking by simple computer models, and measured stratigraphic disorder using rank correlation between age and stratigraphic position (Spearman and Kendall coefficients). Mixing was simulated by randomly transposing pairs of adjacent fossils in a sequence. Reworking was simulated by randomly inserting older fossils into a younger sequence. Mixing is an inefficient means of producing disorder; after 500 mixing steps stratigraphic order is still significant at the 99% to 95% level, depending on the coefficient used. Reworking disorders sequences very efficiently: significant order begins to be lost when reworked shells make up 35% of the sequence. Thus a sequence can be dominated by undisturbed, autochthonous shells and still be disordered. The effects of mixing-produced disorder can be minimized by increasing sample size at each horizon. Increased spacing between samples is of limited utility in dealing with disordered sequences: while widely separated samples are more likely to be stratigraphically ordered, the smaller number of samples makes the detection of trends problematic.

  9. Evidencing syn-sedimentary volcanism in volcaniclastic series using coupled sedimentological and geochronological (U-Pb/zircon) analyses

    NASA Astrophysics Data System (ADS)

    Rossignol, Camille; Poujol, Marc; Bourquin, Sylvie; Dabard, Marie-Pierre; Hallot, Erwan; Nalpas, Thierry

    2015-04-01

    Volcaniclastic sediments, often under-studied, constitute an important part of the global sedimentary record, both in marine and continental environments. These sediments are of particular importance in order to constrain the age of sedimentation, particularly in series where interbedded lava flow are absent. Volcaniclastics sediments are also used in order to constrain the duration of the volcanic activity and to link volcanism with a specific geodynamic context. To demonstrate that volcanism and sedimentation were contemporaneous in a given basin, it is crucial to determine to which extent volcaniclasts present in the volcaniclastic sediments have been reworked. However, this determination is notoriously difficult. As a case study, we characterized the Triassic volcaniclastic series from the Luang Prabang Basin, Laos, using coupled sedimentological and geochronological analyses. Sedimentological and petrographical analyses show a wild range of depositional environments (alluvial fan, braided river and alluvial plain) and evidence for reworking of the volcaniclastics in each of the corresponding deposits. U-Pb geochronology conducted on zircon grains extracted from the volcaniclastic samples of known stratigraphic position indicates that the maximum depositional ages get younger together with the sedimentary succession. This good correlation between absolute ages and stratigraphy demonstrates that, despite evidences of reworking, the volcaniclasts were produced, at least to some extent, contemporaneously with sedimentation. Then, in this specific example, the uncertainties obtained from the U-Pb ages can be used to indicate the 'reworking time scale', defined as the difference between the age of volcaniclast production and the depositional age of its host strata. Short reworking time scales, of ca. 1 Ma, one order of magnitude smaller than the total duration of the sedimentary record reveal that volcanism and sedimentation were contemporaneous. The use of coupled

  10. 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.

  11. 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

  12. 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.

  13. Oxidation of detrital pyrite as a cause for Marcasite Formation in marine lag deposits from the Devonian of the eastern US

    NASA Astrophysics Data System (ADS)

    Schieber, Juergen

    2007-06-01

    Late Devonian black shale successions in the eastern US contain numerous discontinuities that are characterized by lags containing variable amounts of quartz sand mixed with reworked pyritic and phosphatic debris. These lags can be partially cemented by iron sulfides with a radial fibrous to massive morphology. Examination of iron sulfide cements via electron backscatter diffraction (EBSD) shows that these cements can consist entirely or partially of marcasite. It is proposed here that oxidation and dissolution of reworked pyrite debris led to favorable conditions for intermittent rapid marcasite formation by forcing a substantial pH drop in the surface sediment and by raising dissolved iron concentrations in the pore waters.

  14. Maceral, total organic carbon, and palynological analyses of ross ice shelf project site j9 cores.

    PubMed

    Wrenn, J H; Beckman, S W

    1982-04-01

    Analyses of macerals and total organic carbon indicate that the low organic content of core sediments from Ross Ice Shelf Project site J9 has been selectively reduced further, probably by postdepositional submarine oxidation. Palynological analysis revealed a reworked Paleogene dinocyst flora of low diversity (the transantarctic flora). This constitutes the most southerly dinocyst flora reported thus far. The antarctic distribution of the transantarctic flora supports the existence of a transantarctic strait during the Paleogene. The J9 sporomorph assemblage also is reworked and Paleogene in age. PMID:17736253

  15. 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.

  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. 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.

  18. 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…

  19. 40 CFR 63.3881 - Am I subject to this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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)...

  20. The Quest for Holism in Education for Sustainable Development.

    ERIC Educational Resources Information Center

    Stables, Andrew; Scott, William

    2002-01-01

    Sustainable development can remain a regulative ideal for environmental educators with the acknowledgement that it has no absolute legitimation and that human reflexivity remains capable of reworking the cultural traditions that have shaped it. Claims that the quest for holism remains one voice in a continuing dialogue about the environment and…

  1. Irradiation stratigraphy and depositional history of the Apollo 16 double drive tube 60009/10

    NASA Technical Reports Server (NTRS)

    Blanford, G. E.; Blanford, J.; Hawkins, J. A.

    1979-01-01

    We report track density frequency distributions, the fraction of high density grains and minimum track densities for 63, 1 mm wide locations in the Apollo 16 double drive tube 60009/10. From these data we conclude that there are seven irradiation strata in the core. Only one buried reworking zone extending from 50-52 cm was found and it was exposed near the surface from 4.5-9 times 10 to the 6th y with a most probable exposure period of 6 times 10 to the 6th y. There is lack of conclusive data that this zone represents a reworking zone in which case the material below 52 cm most probably was exposed in situ for 4.5 times 10 to the 6th y and developed a reworking zone approximately less than 0.5 cm. The present surface of the core has a reworking zone of 12-13 cm which was exposed from 1.3 times 10 to the 7th to 2.5 times 10 to the 8th y. The best estimate for this exposure period remains the value of approximately less than 1.25 times 10 to the 8th y determined by Bogard and Hirsch (1976). The other strata in the core appear to contain mixtures of various soil types and are not related to in situ depositional events.

  2. 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.…

  3. 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

  4. 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…

  5. 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…

  6. 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…

  7. 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…

  8. 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…

  9. 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.

  10. 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…

  11. 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

    ... procedures prescribed in 5 CFR 1320.12. On Tuesday, June 22, 2010 (75 FR 35454), EPA sought comments on this... Manufacturing and Rework Industry Information Collection AGENCY: Environmental Protection Agency (EPA). ACTION... and cost. DATES: Additional comments may be submitted on or before October 28, 2010. ADDRESSES:...

  12. 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.

  13. 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…

  14. 75 FR 38007 - Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ... Federal Register on April 12, 2010 (75 FR 18446). That NPRM proposed to require reworking or replacing... ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), and (3) Will... (BMS) 8-39 polyurethane foam insulation. This proposed AD also results from a report from the...

  15. 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…

  16. Developing a Network of and for Geometric Reasoning

    ERIC Educational Resources Information Center

    Mamolo, Ami; Ruttenberg-Rozen, Robyn; Whiteley, Walter

    2015-01-01

    In this article, we develop a theoretical model for restructuring mathematical tasks, usually considered advanced, with a network of spatial visual representations designed to support geometric reasoning for learners of disparate ages, stages, strengths, and preparation. Through our geometric reworking of the well-known "open box…

  17. 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…

  18. 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…

  19. "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…

  20. 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.

  1. 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…

  2. Education and Women's Work: Some New Research Directions.

    ERIC Educational Resources Information Center

    Gaskell, Jane

    1983-01-01

    Discusses the school-work relationship for women, noting that pertinent research traditions (occupational status attainment research, human capital research) have focused on men and male-female differences. Suggests reworking the models to focus on male-female differences in education (academic achievement, course choices, school socialization).…

  3. 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.

  4. 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...

  5. Testing Gimbal Axes Before Complete Assembly

    NASA Technical Reports Server (NTRS)

    Babis, W.

    1986-01-01

    Early testing increases chances assembly will function well without expensive rework. Developed for antenna gimbals, test eliminates delay and costs ensued when fully assembled antenna fails because of excessive torque and friction in gimbal. Gimbal housing mounted above rotary table. Gimbal axis tested connected to torque transducer on table. With exception of special holder for gimbal housing, all of testing instruments commercially available items.

  6. Funding Phantom Students

    ERIC Educational Resources Information Center

    Roza, Marguerite; Fullerton, Jon

    2013-01-01

    Many state education leaders are taking a fresh look at school finance in hopes of containing costs. Some are reworking transportation formulas, or zeroing in on special education eligibility, or merging districts. Others are investing more in digital learning, charter innovations, and information systems. But state leaders too often overlook a…

  7. Spatial patterns of scour and fill in dryland sand bed streams 1843

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spatial patterns of scour and fill in two dryland ephemeral stream channels with sandy bed material have been measured with dense arrays of scour chains. Although the depth and areal extent of bed activity increased with discharge, active bed reworking at particular locations within the reaches res...

  8. 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)

  9. "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…

  10. 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.

  11. 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…

  12. 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…

  13. 262. SENIOR OFFICER'S QUARTERS A, 194041. GEORGE A FULLER AND ...

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

    262. SENIOR OFFICER'S QUARTERS A, 1940-41. GEORGE A FULLER AND CO., DESIGNERS OF THE REWORKING OF A C. 1939 SUMMER COTTAGE INTO THIS NEOCOLONIAL RESIDENCE--THE LARGEST AND FOCAL ELEMENT IN THE SENIOR OFFICERS HOUSING AREA. VIEW FROM THE WEST SHOWING THE ENTRANCE ELEVATION OF QUARTERS A. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  14. Measuring Quality, Framing What We Know: A Critical Discourse Analysis of the Common Inspection Framework

    ERIC Educational Resources Information Center

    Dennis, Carol

    2011-01-01

    In "Measuring quality: framing what we know" I offer a critique of "Success in Adult Literacy, Numeracy and ESOL provision (Success in ALNE)"--a contextualised reworking of the common inspection framework. This document offers a government-sponsored account of what quality means when applied to the teaching of adult language, literacy and…

  15. A BETHNIC BIOASSAY USING TIME-LAPSE PHOTOGRAPHY TO MEASURE THE EFFECT OF TOXICANTS ON THE FEEDING BEHAVIOR OF LUGWORMS (POLYCHAETA:ARENICOLIDAE)

    EPA Science Inventory

    A benthic assay was developed utilizing time-lapse photography to measure the feeding activity of a lugworm, Arenicola cristata. Automated 35 mm cameras were used to record formation of feeding funnels at 12-hour intervals. Substrate surface area reworked by lugworms held under i...

  16. 228. Photocopy of drawing (1976 structural drawing by StearnsRoger Incorporated) ...

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

    228. Photocopy of drawing (1976 structural drawing by Stearns-Roger Incorporated) FACING REWORK FOR THE UMBILICAL MAST, SHEET 511-S13 - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  17. 227. Photocopy of drawing (1977 structural drawing by StearnsRoger Incorporated) ...

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

    227. Photocopy of drawing (1977 structural drawing by Stearns-Roger Incorporated) LVXM MODIFICATIONS, FACING REWORK FOR THE UMBILICAL MAST, SHEET 501-S29 - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  18. Missed Opportunities: The Subordination of Children in Philip Pullman's "His Dark Materials"

    ERIC Educational Resources Information Center

    Moruzi, Kristine

    2005-01-01

    In the "His Dark Materials" trilogy, Pullman reworks the fall of humanity into an ascent and suggests that ascent into adulthood through sexual experience is the desired goal for children. Although this ascent is accompanied by a radical reconceptualization of life and death, Pullman fails to offer any genuinely new ideas of the world with respect…

  19. Staging an Educated Self: Linguistic Displays of Schooling among Rural Zambian Children

    ERIC Educational Resources Information Center

    Clemensen, Nana

    2015-01-01

    This article explores interpretations of schooling as produced by 6-12-year-old children in a rural Zambian community. Applying linguistic-anthropological analyses of their peer interactions, the author discusses symbolic reworkings of schooling and "educatedness" among children frequently labeled as "slow" or…

  20. Ultrasonic Probe For In Situ Inspection Of Welds

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L.; Paternoster, Vincent Y.

    1992-01-01

    End effector on welding robot contains ultrasonic transducer detecting such flaws as tungsten inclusions and lack of penetration of weld immediately after weld made, while workpiece still mounted; weld reworked in place, if necessary. Mounted on standard arc-welding torch; same length as long gas cup with electrode.

  1. Shear-Wave Ultrasonic Inspection With A Dry Couplant

    NASA Technical Reports Server (NTRS)

    Willenberg, James D; Van Wyk, Lisa

    1994-01-01

    Automated ultrasonic inspection system includes dry couplant pad attached to ultrasonic transducer. Designed to be mounted on robot arm in automated manufacturing (robotic welding) work cell. Between, during, or after manufacturing operations, robot scans ultrasonic transducer along workpiece. Workpiece reworked in place, if necessary. In principle, computer program controlling inspection overlaid on program controlling welding operations.

  2. 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…

  3. "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),…

  4. Modern sedimentary environments in Boston Harbor, Massachusetts

    USGS Publications Warehouse

    Knebel, H. J.; Rendigs, R. R.; Bothner, Michael H.

    1991-01-01

    1) Environments of erosion appear on the sonographs either as patterns with isolated strong reflections or as uniform patterns of strong reflectivity. 2) Environments of deposition are depicted on the sidescan-sonar records as smooth, featureless surfaces that have low to moderate reflectivity. 3) Environments of sediment reworking constitute areas affected by a combination of erosional and depositional processes. -from Authors

  5. 40 CFR 63.3881 - Am I subject to this subpart?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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)...

  6. 40 CFR 63.3881 - Am I subject to this subpart?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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)...

  7. 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...

  8. 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.

  9. 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)

  10. 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.

  11. An Approach to Revision and Evaluation of Student Writing.

    ERIC Educational Resources Information Center

    Duke, Charles R.

    An approach to evaluating student writing that emphasizes reformulation and deemphasizes grades teaches students that reworking their writing is a necessary and acceptable part of the writing process. Reformulation is divided into rewriting, revising, and editing. The instructor diagnoses student papers to determine significant problems on a…

  12. 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... 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 63.4481 - 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... 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...

  14. 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…

  15. Imagination as a Vehicle for Comprehension Instruction

    ERIC Educational Resources Information Center

    Villarreal, Lorena A.

    2013-01-01

    Imagination has been described as a cognitive endeavor that serves as a catalyst for creative actions and aids in the development of comprehension skills. Studies show that incorporating imagination into classroom practice builds on children's lived experiences and encourages the creative reworking of elements that enable the generation of new…

  16. 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…

  17. 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…

  18. 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 ...

  19. "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)

  20. 40 CFR 63.745 - Standards: Primer and topcoat application operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... in paragraph (c) of this section for those coatings that are uncontrolled (no control device is used... coatings that are controlled (organic HAP emissions from the operation are reduced by the use of a control... topcoat (less water) as applied for general aviation rework facilities. (d) Controlled...

  1. 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)...

  2. 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...

  3. 40 CFR 63.745 - Standards: Primer and topcoat application operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... in paragraph (c) of this section for those coatings that are uncontrolled (no control device is used... coatings that are controlled (organic HAP emissions from the operation are reduced by the use of a control... topcoat (less water) as applied for general aviation rework facilities. (d) Controlled...

  4. Preliminary evaluation of hermetic JT/LJT/R P connector socket contact design

    SciTech Connect

    Baca, J.R.F.

    1991-10-01

    This report presents a precursory examination of a number of issues pertaining to socket contacts in hermetic connectors. The principal issues addressed are high-contact resistance and contact chatter (circuit discontinuities). Efforts examining the characteristics of the existing socket contact design, the possibility of connector/contact rework, quick-fix solutions, and contact redesigns are summarized.

  5. 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…

  6. Tales of Recombinant Femininity: "The Reincarnation of Golden Lotus," the "Chin P'ing Mei," and the Politics of Melodrama in Hong Kong.

    ERIC Educational Resources Information Center

    Fore, Steve

    1993-01-01

    Examines the film "The Reincarnation of Golden Lotus" and the text upon which it is loosely based, the "Chin P'ing Mei," and the relationship between it and modern Chinese culture. States that the film's screenplay is much less an adaptation of the source novel than it is a female-centered reworking of a particular narrative and thematic elements.…

  7. 78 FR 27010 - Airworthiness Directives; The Boeing Company Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-09

    ...We are superseding two existing airworthiness directives (AD) that apply to certain The Boeing Company Model 737-100, -200, -200C, - 300, -400, and -500 series airplanes. Those ADs, for certain airplanes, currently require repetitive inspections of the flap track of the wing outboard flap, and corrective actions if necessary; and eventual rework of the flap track assembly and rear spar......

  8. 30 CFR 556.72 - Compensatory payments as production.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Compensatory payments as production. 556.72... § 556.72 Compensatory payments as production. If an oil and gas lessee makes compensatory payments and... or by other approved drilling or reworking operations, such payments shall be considered as...

  9. 30 CFR 256.72 - Compensatory payments as production.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Compensatory payments as production. 256.72....72 Compensatory payments as production. If an oil and gas lessee makes compensatory payments and if... by other approved drilling or reworking operations, such payments shall be considered as...

  10. 30 CFR 556.72 - Compensatory payments as production.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Compensatory payments as production. 556.72... § 556.72 Compensatory payments as production. If an oil and gas lessee makes compensatory payments and... or by other approved drilling or reworking operations, such payments shall be considered as...

  11. 30 CFR 556.72 - Compensatory payments as production.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Compensatory payments as production. 556.72... § 556.72 Compensatory payments as production. If an oil and gas lessee makes compensatory payments and... or by other approved drilling or reworking operations, such payments shall be considered as...

  12. 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.

  13. 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.

  14. 77 FR 11019 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbofan Engines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... Federal Register published on April 11, 2000 (65 FR 19477-78). Discussion The European Aviation Safety... also estimate that it would take about 5 work-hours per engine to perform one inspection, and about 8 work-hours per engine to perform the rework. The average labor rate is $85 per work-hour. Based...

  15. 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…

  16. 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…

  17. 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…

  18. 48 CFR 15.408 - Solicitation provisions and contract clauses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., travel, computer and consultant services, preservation, packaging and packing, spoilage and rework, and... records as of the cutoff date. These include such costs as preproduction engineering, special plant... charged on your accounting records (e.g., included in production costs as direct engineering...

  19. 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".…

  20. 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…

  1. Schools, Discipline and Community: Diary-writing and Schoolgirl Culture in Late Nineteenth-Century France.

    ERIC Educational Resources Information Center

    Rogers, Rebecca

    1995-01-01

    Maintains that 19th-century French boarding school culture used the idea of community to transmit feminine but not necessarily domestic values. These included obedience, selflessness, and interdependence. Students, however, transformed and reworked these messages to fit their individual needs, as revealed by one young woman's diary. (MJP)

  2. Action Research and the Assemblage: Engaging Deleuzian Pedagogy and Inquiry beyond the Constraints of the Individual and the Group in Education Settings

    ERIC Educational Resources Information Center

    Gale, Ken

    2014-01-01

    Drawing upon the author's previous attempts to engage the work of Deleuze and Deleuze and Guattari with contemporary pedagogic practices and research, this paper offers a conceptually tentative reworking of the theory and practice of action research, both as a means of challenging antecedent positions and as a way of proposing a volatile and…

  3. 30 CFR 206.452 - Coal subject to royalties-general provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... provisions. (a) All coal (except coal unavoidably lost as determined by BLM pursuant to 43 CFR group 3400... compensation received by the lessee for other losses. (c) If waste piles or slurry ponds are reworked to... the production method used to initially mine coal in the waste pile or slurry pond; i.e.,...

  4. 30 CFR 206.253 - Coal subject to royalties-general provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... provisions. (a) All coal (except coal unavoidably lost as determined by BLM under 43 CFR part 3400) from a... compensation received by the lessee for other losses. (c) If waste piles or slurry ponds are reworked to... the production method used to initially mine coal in the waste pile or slurry pond; i.e.,...

  5. 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.

  6. 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.

  7. Burrow-generated false facies and phantom sequences

    SciTech Connect

    Wanless, H.R.; Tagett, M.

    1986-05-01

    Callianassa (=Ophiomorpha) and other burrowers deeply rework shallow marine sequences. Through in-situ reworking, they create false sedimentary facies and stratigraphic sequences. Callianassa's key to effectiveness is that it expels sand and mud from burrow excavations but concentrates coarse material at the base of the burrow complex. Coarse material can be derived by falling into the burrow entrance, by reworking the existing sediment sequence, or by a combination of both. Examples come from shallow marine carbonate environments of south Florida and the Turks and Caicos Islands, British West Indies. Many mudbanks in south Florida are formed as stacks of layered mudstone units 20-100 cm thick. Between events, seagrasses may recolonize, and a burrowing benthic community may repopulate the substrate. The layered mudstone beneath older areas of mudbank flats can gradually be converted to a bioturbated skeletal wackestone by the deep burrowing community. Burrowing also causes mixing of faunal assemblages. On Caicos Bank, an extensive carbonate tidal flat (3-4 m thick) is slowly being transgressed. About 1 m of tidal-flat sequence is eroded at the shoreline. The remaining 2-3 m could be preserved as part of the transgressive sequence. Callianassa burrowing, however, quickly reworks the sequence, replacing tidal-flat sands and muds with marine peloidal and skeletal sediment. Within 100 m of the shoreline, the only evidence of the tidal-flat sequence is a concentration of high-spired gastropods in Calliannassa burrows at the base of the Holocene sequence and a few patches of tidal-flat sediment that burrowers missed. What looks like a basal transgressive lag is in fact a biogenic concentrate from in-situ reworking of a now phantom sequence.

  8. Comparative studies of grain size separates of 60009. [lunar soil samples

    NASA Technical Reports Server (NTRS)

    Mckay, D. S.; Morris, R. V.; Dungan, M. A.; Fruland, R. M.; Fuhrman, R.

    1976-01-01

    Five samples from 60009, the lower half of a double drive tube, were analyzed via grain-size methods, with particle types classified and counted in the coarser grain sizes. Studies were undertaken of particle types and distributions by petrographic methods, of magnetic fractions, of the size splits and magnetic splits as analyzed by ferromagnetic resonance (FMR) techniques, of maturity (based on agglutinate content, FMR index Is/FeO, mean size of sub-cm material, magnetic fraction), of possible reworking or mixing in situ, and of depositional history. Maturity indices are in substantial agreement for all of the five samples. Strong positive correlation of percent agglutinates and percent bedrock-derived lithic fragments, combined with negative correlation of those components with percent single crystal plagioclase, argue against in situ reworking of the same soil.

  9. Some observations on value and greatness in drama.

    PubMed

    Mandelbaum, George

    2011-04-01

    This paper argues that value in drama partly results from the nature of the resistance in a scene, resistance used in its common, everyday meaning. A playwright's ability to imagine and present such resistance rests on several factors, including his sublimation of the fantasies that underpin his work. Such sublimation is evident in Chekhov's continuing reworking in his plays of a fantasy that found its initial embodiment for him in one of the central scenes in Hamlet. The increasingly higher value of the scenes Chekhov wrote as he repeatedly reworked Shakespeare's scene resulted from his increasing sublimation of the initial fantasy and is reflected in the ever more complex nature of the resistance found in Chekhov's scenes, resistance that, in turn, created an ever more life-like, three-dimensional central character in the scenes. PMID:21518367

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Thermally Conductive-Silicone Composites with Thermally Reversible Cross-links.

    PubMed

    Wertz, J T; Kuczynski, J P; Boday, D J

    2016-06-01

    Thermally conductive-silicone composites that contain thermally reversible cross-links were prepared by blending diene- and dienophile-functionalized polydimethylsiloxane (PDMS) with an aluminum oxide conductive filler. This class of thermally conductive-silicones are useful as thermal interface materials (TIMs) within Information Technology (IT) hardware applications to allow rework of valuable components. The composites were rendered reworkable via retro Diels-Alder cross-links when temperatures were elevated above 130 °C and required little mechanical force to remove, making them advantageous over other TIM materials. Results show high thermal conductivity (0.4 W/m·K) at low filler loadings (45 wt %) compared to other TIM solutions (>45 wt %). Additionally, the adhesion of the material was found to be ∼7 times greater at lower temperatures (25 °C) and ∼2 times greater at higher temperatures (120 °C) than commercially available TIMs. PMID:27224959

  16. 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.

  17. The nature of rays and sources of highland material in Mare Crisium

    NASA Technical Reports Server (NTRS)

    Maxwell, T. A.; El-Baz, F.

    1978-01-01

    Although highland fragments are rare in the Luna 24 core, they should provide an important source of information on the sequence of formation and lithology of lunar east-limb basins. The numerous rays that cross the Crisium basin suggest several sources of highland materials. Both deposition of primary ejecta and reworking of local material were most likely responsible for the formation of ray systems in Mare Crisium. In addition to the fact that Luna 24 landed near the uprange end of a Giordano Bruno ray, incomplete sampling of the uppermost layer and formation of the ray by reworking of in situ regolith suggest that its materials may be scarce or not present in the core. Highland fragments present are most likely to be representative of several highland sources.

  18. Regolith stratigraphy at the Chang'E-3 landing site as seen by lunar penetrating radar

    NASA Astrophysics Data System (ADS)

    Fa, Wenzhe; Zhu, Meng-Hua; Liu, Tiantian; Plescia, Jeffrey B.

    2015-12-01

    The Chang'E-3 lunar penetrating radar (LPR) observations at 500 MHz reveal four major stratigraphic zones from the surface to a depth of ~20 m along the survey line: a layered reworked zone (<1 m), an ejecta layer (~2-6 m), a paleoregolith layer (~4-11 m), and the underlying mare basalts. The reworked zone has two to five distinct layers and consists of surface regolith. The paleoregolith buried by the ejecta from a 500 m crater is relatively homogenous and contains only a few rocks. Population of buried rocks increases with depth to ~2 m at first, and then decreases with depth, representing a balance between initial deposition of the ejecta and later turnover of the regolith. Combining with the surface age, the LPR observations indicate a mean accumulation rate of about 5-10 m/Gyr for the surface regolith, which is at least 4-8 times larger than previous estimation.

  19. New environmental regulation for the aerospace industry: The aerospace NESHAP

    SciTech Connect

    Bauer, J.P.; Gampper, B.P.; Baker, J.M.

    1997-12-31

    40 CFR Part 63, Subpart GG, the National Emission Standard for Hazardous Air Pollutants for Aerospace Manufacturing and Rework Facilities, commonly referred to as the Aerospace NESHAP, was issued on September 1, 1995 and requires compliance by September 1, 1998. The regulation affects any facility that manufactures or reworks commercial, civil, or military aircraft vehicles or components and is a major source of Hazardous Air Pollutants (HAPs). The regulation targets reducing Volatile Organic Compound (VOC) and Hazardous Air Pollutant (HAP) emissions to the atmosphere. Processes affected by the new regulation include aircraft painting, paint stripping, chemical milling masking, solvent cleaning, and spray gun cleaning. Regulatory requirements affecting these processes are summarized, and different compliance options compared in terms of cost-effectiveness and industry acceptance. Strategies to reduce compliance costs and minimize recordkeeping burdens are also presented.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Oligocene lacustrine tuff facies, Abu Treifeya, Cairo-Suez Road, Egypt

    NASA Astrophysics Data System (ADS)

    Abdel-Motelib, Ali; Kabesh, Mona; El Manawi, Abdel Hamid; Said, Amir

    2015-02-01

    Field investigations in the Abu Treifeya area, Cairo-Suez District, revealed the presence of Oligocene lacustrine volcaniclastic deposits of lacustrine sequences associated with an Oligocene rift regime. The present study represents a new record of lacustrine zeolite deposits associated with saponite clay minerals contained within reworked clastic vitric tuffs. The different lithofacies associations of these clastic sequences are identified and described: volcaniclastic sedimentary facies represent episodic volcaniclastic reworking, redistribution and redeposition in a lacustrine environment and these deposits are subdivided into proximal and medial facies. Zeolite and smectite minerals are mainly found as authigenic crystals formed in vugs or crusts due to the reaction of volcanic glasses with saline-alkaline water or as alteration products of feldspars. The presence of abundant smectite (saponite) may be attributed to a warm climate, with alternating humid and dry conditions characterised by the existence of kaolinite. Reddish iron-rich paleosols record periods of non-deposition intercalated with the volcaniclastic tuff sequence.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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)

  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. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  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. Tsunami and seiche-triggered deformation within offshore sediments

    NASA Astrophysics Data System (ADS)

    Alsop, G. Ian; Marco, Shmuel

    2012-06-01

    Most studies of tsunami and seiche related deposits have focussed on coastal and near coastal zones which are most readily accessible, with few investigations of deeper water settings and the potential soft-sediment deformation effects of such waves. The Late Pleistocene Lisan Formation outcropping to the west of the Dead Sea contains superb examples of sedimentary slump folds formed in water depths of < 100 m. We have collected new structural data from an individual horizon that demonstrate that these gravity-driven slumps may be coaxially refolded and reworked by sheared folds and thrusts verging both back up and then down the palaeoslope. This suggests that it is possible to generate upslope flow of material in some circumstances. A progressive increase in reworking and shearing is developed up through the folded sediment, culminating in a breccia layer that is capped by a thin, typically graded horizon of undeformed silt and sand. We suggest that these sequentially reworked deposits are consistent with seismically triggered tsunami and seiche waves that would flow back and forth across the main slump horizon triggered by the same earthquake. The overlying sands and silts that infill local topography are considered to be deposited from turbid suspension during cessation of wave action and represent homogenite deposits. Although tsunami and seiche waves have previously been both numerically modelled and directly witnessed in the Dead Sea Basin, this study forms the first detailed structural analysis and interpretation of potential reworking associated with such waves in offshore settings, where the potential for preservation in the geological record is increased.

  19. 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.

  20. Dimpled ball grid array process development for space flight applications

    NASA Technical Reports Server (NTRS)

    Barr, S. L.; Mehta, A.

    2000-01-01

    A 472 dimpled ball grid array (D-BGA) package has not been used in past space flight environments, therefore it was necessary to develop a process that would yield robust and reliable solder joints. The process developing assembly, inspection and rework techniques, were verified by conducting environmental tests. Since the 472 D-BGA packages passed the above environmental tests within the specifications, the process was successfully developed for space flight electronics.

  1. 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

  2. Source Inspection Scheduling Calendar

    NASA Technical Reports Server (NTRS)

    Hollis, Brayden

    2011-01-01

    Quality is an essential component for creating flight hardware travelling through space since the hardware is extremely expensive and cannot be reworked or repaired once launched. An important step in this process is ensuring the quality of hardware procured from Jet Propulsion Laboratory's (JPL) suppliers. An important element of determining supplier quality is source inspection. Source inspections are performed at suppliers' facilities by JPL employeesto ensure that hardware characteristics are acceptable before being covered up and/or delivered to JPL.

  3. 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

  4. 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.…

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Toward an understanding of the impact of production pressure on safety performance in construction operations.

    PubMed

    Han, Sanguk; Saba, Farzaneh; Lee, Sanghyun; Mohamed, Yasser; Peña-Mora, Feniosky

    2014-07-01

    It is not unusual to observe that actual schedule and quality performances are different from planned performances (e.g., schedule delay and rework) during a construction project. Such differences often result in production pressure (e.g., being pressed to work faster). Previous studies demonstrated that such production pressure negatively affects safety performance. However, the process by which production pressure influences safety performance, and to what extent, has not been fully investigated. As a result, the impact of production pressure has not been incorporated much into safety management in practice. In an effort to address this issue, this paper examines how production pressure relates to safety performance over time by identifying their feedback processes. A conceptual causal loop diagram is created to identify the relationship between schedule and quality performances (e.g., schedule delays and rework) and the components related to a safety program (e.g., workers' perceptions of safety, safety training, safety supervision, and crew size). A case study is then experimentally undertaken to investigate this relationship with accident occurrence with the use of data collected from a construction site; the case study is used to build a System Dynamics (SD) model. The SD model, then, is validated through inequality statistics analysis. Sensitivity analysis and statistical screening techniques further permit an evaluation of the impact of the managerial components on accident occurrence. The results of the case study indicate that schedule delays and rework are the critical factors affecting accident occurrence for the monitored project. PMID:24184131

  11. 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.

  12. Origin of basaltic soils at Gusev crater, Mars, by aeolian modification of impact-generated sediment

    NASA Astrophysics Data System (ADS)

    McGlynn, Ian O.; Fedo, Christopher M.; McSween, Harry Y., Jr.

    2011-04-01

    Textural properties of soils including grain size, sorting, modality, skewness, shape (quantified as sphericity and qualified as form), roundness, and grain size distribution, have been measured and calculated from Microscopic Imager (MI) high-resolution images from the Mars Exploration Rover (MER) Spirit in Gusev crater. Soil targets were classified by grain size into five groups: fine to medium sand dark soil, medium sand to very fine pebble bed form armor, and very fine to medium pebble lithic fragments, a bimodal mixed soil, and an excavated soil trench. The abundance of submature, very poorly sorted, bimodal mixed soils indicates incomplete sorting by soil type. Probability distributions of excavated subsurface soil match crushed sediment analogs, indicating impact comminution, while all other soils show no direct evidence of an impact origin. If soils were produced primarily by impacts, then the evidence from probability distributions, angular shapes, and agglutinates have been reworked by postimpact surface activity. Soils in Gusev crater are continuously modified, reworked, and sandblasted. Textures of surface sediments are disconnected from subsurface textures and only reflect modern surficial aeolian processes. Models to reconstruct physical and chemical soil formation properties should not assume a static three-dimensional structure. A three-step model, initiated by the formation of basaltic crust and its alteration, followed by bolide impact, and finally modification by aeolian reworking is envisioned for the formation of soils. Such a scenario accounts for the potential that surface sediments may be compositionally and texturally distinct from the subsurface.

  13. Sedimentary processes and sediment dispersal in the southern Strait of Georgia, BC, Canada.

    PubMed

    Hill, Philip R; Conway, Kim; Lintern, D Gwyn; Meulé, Samuel; Picard, Kim; Barrie, J Vaughn

    2008-12-01

    This paper presents a review of sediment dispersal processes in the Strait of Georgia, based on marine geological studies. Sediment from the Fraser River is dispersed around the Strait through a variety of transport pathways. Most sand and coarser silt fractions settle out and are deposited within a few 100 m of the channel mouths. Both channelled and non-channelled gravity flows probably transport sediment downslope and onto the basin floor. Asymmetric tidal currents force a predominantly northward sediment drift, resulting in a reworked slope off Roberts Bank and a finer-grained depositional slope off Sturgeon Bank. Far-field sediment accumulation is controlled by local morphology and sediment dynamics. Multibeam mapping and seismic profiling reveal that some parts of the basin floor are characterized by bottom sediment reworking and erosion. Given the complexities of sediment dispersal and seafloor reworking, generalizations about sediment dispersal paths and sedimentation rates are difficult. Future understanding will be advanced by the cabled observatory, VENUS, which will enable near real-time monitoring of key processes. PMID:18996583

  14. 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.

  15. Sedimentary cycles related to the late Palaeozoic cold-warm climate change, Talchir Formation, Talchir Basin, India

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Biplab

    2013-06-01

    Attributes of sedimentary facies within Permo-Carboniferous Talchir Formation (Gondwana Supergroup), Talchir Basin, India, attest to sedimentation under glaciomarine setting. Facies architecture reveals three sedimentary cycles of distinct orders. Cycle-1 sediments are 10s of m thick and are represented by repeated occurrences of glacigenic/reworked-glacigenic sediments followed by storm-reworked glacial outwash deposits. Juxtaposition of multiple Cycle-1 sequences indicate repeated ice-front advance-retreats related to climatic fluctuations, which led to accumulation of glacier-laden coarse-grained sediments, and subsequent flooding by marine storm surges. Cm-thin sandstone-mudstone interbeds of Cycle-2 belong within the Cycle-1 sequences and represent deposition from episodic storm surges. Mm-thin Cycle-3 sediments occur within the Cycle-2 sequences and attribute their genesis to semi-diurnal tidal fluctuations. Open marine storm surges have reworked these tidal sediments. In absence of major tectonic influences, the studied sedimentary cycles and associated palaeogeographic changes in the ice-marginal Talchir marine basin bear direct relation to late Palaeozoic cold-warm climatic transitions.

  16. Geomorphological consequences of a glacier advance across a paraglacial rock avalanche deposit

    NASA Astrophysics Data System (ADS)

    Cook, Simon J.; Porter, Philip R.; Bendall, Charles A.

    2013-05-01

    Glacial reworking of paraglacial rock slope sediment has been inferred from long-deglaciated terrains to contribute significantly to glacial sediment transfer. At Feegletscher, Switzerland, we provide the first description of the geomorphological consequences of glacier advance across paraglacial rock avalanche sediment. This produced a small arcuate end moraine that encloses a zone of hummocky debris. The sedimentology of these landforms is conditioned by rock avalanche sediment and can be differentiated from purely glacial sediments, indicating that the contribution of glacially reworked rock avalanche debris may be recognisable in deglaciated terrain. Remarkably, much of the overridden rock avalanche debris has maintained its angularity and delicate brecciation features, despite up to 40 years of glacial action. We suggest that the surface 'carapace facies' of the rock avalanche deposit, comprising large openwork blocks, limited the effectiveness of glacial erosion processes. The carapace facies will have resisted significant erosion by the relatively thin glacier because of its high shear strength and because it was able to transmit subglacial meltwater efficiently. Thus, enhanced debris transfer associated with reworking of paraglacial rock avalanche sediment should not necessarily be expected during the initial stages of glacier advance.

  17. 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

  18. 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

  19. 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

  20. Unsteady diagenetic processes and sulfur biogeochemistry in tropical deltaic muds: Implications for oceanic isotope cycles and the sedimentary record

    NASA Astrophysics Data System (ADS)

    Aller, Robert C.; Madrid, Vanessa; Chistoserdov, Andrei; Aller, Josephine Y.; Heilbrun, Christina

    2010-08-01

    Sedimentary S cycling is usually conceptualized and interpreted within the context of steadily accreting (1-D) transport-reaction regimes. Unsteady processes, however, are common in many sedimentary systems and can result in dramatically different S reaction balances and diagenetic products than steady conditions. Globally important common examples include tropical deltaic topset and inner shelf muds such as those extending from the Amazon River ˜1600 km along the Guianas coast of South America. These deposits are characterized by episodic reworking of the surface seabed over vertical depths of ˜0.1-3 m. Reworked surface sediments act as unsteady, suboxic batch reactors, unconformably overlying relict anoxic, often methanic deposits, and have diagenetic properties largely decoupled from net accumulation of sediment. Despite well-oxygenated water and an abundant reactive organic matter supply, physical disturbance inhibits macrofauna, and benthic communities are dominated by microbial biomass across immense areas. In the surficial suboxic layer, molecular biological analyses, tracer experiments, sediment C/S/Fe compositions, and δ 34S, δ 18O of pore water SO42- indicate close coupling of anaerobic C, S, and Fe cycles. δ 18O- SO42- can increase by 2-3‰ during anaerobic recycling without net change in δ 34S- SO42-, demonstrating SO42- reduction coupled to complete anaerobic reoxidation to SO42- and a δ 18O- SO42- reduction + reoxidation fractionation factor⩾12‰ (summed magnitudes). S reoxidation must be coupled to Fe-oxide reduction, contributing to high dissolved Fe 2+ (˜1 mM) and Fe mobilization-export. The reworking of Amazon-Guianas shelf muds alone may isotopically alter δ 18O- SO42- equivalent in mass to⩾25% of the annual riverine delivery of SO42- to the global ocean. Unsteady conditions result in preservation of unusually heavy δ 34S isotopic compositions of residual Cr reducible S, ranging from 0‰ to >30‰ in physically reworked deposits

  1. 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

  2. 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

  3. 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

  4. 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

  5. Summary and synthesis of geomorphic studies conducted during the 1996 controlled flood in Grand Canyon

    NASA Astrophysics Data System (ADS)

    Schmidt, John C.

    The 1996 controlled flood demonstrated that a discharge of 1274 m3/s was sufficient to form or rework alluvial deposits along the Colorado River in Grand Canyon. This flood was moderately large in relation to other floods that have occurred since Glen Canyon Dam was completed in 1963. The flood also provided the opportunity to make measurements of physical processes that occurred. The flood caused widespread deposition of sand to elevations 3-5 m above the stage of the administratively-determined minimum daytime dam release of 227 m3/s and caused an increase in the area and volume of the high-elevation parts of sand bars, thereby increasing the number of new campsites. The low-elevation parts of the same eddies were eroded, as were adjacent channel pools. Recently-aggraded debris fans were reworked. Suspended-sediment transport measurements showed that suspended-sand concentrations decreased with time and that transport rates are highest when the channel bed is relatively fine and has a higher proportion of sand. The controlled flood was most effective during the first 4 days when mainstem transport rates and eddy deposition rates were high; debris-fan reworking entirely occurred during the first 4 hrs at one site. Modeling studies strongly indicate that resultant eddy-bar topography depends greatly on the concentration of mainstem suspended sediment and the initial topography of eddies. Large-scale erosion occurred on different days at different sites and had the potential to evacuate large proportions of newly-deposited sand from eddies. The final flood-formed topography of eddy bars was thus highly variable from site to site and from reach to reach.

  6. Exploration potential and variations in shelf plume sandstones, Navarro group (Maestrichtian), east-central Texas

    SciTech Connect

    Patterson, J.E. Jr.; Scott, A.J.

    1984-04-01

    Fine-grained marine sandstones within the Kemp Clay of the Navarro Group (Maestrichtian) of east-central Texas were deposited on a muddy, shallow shelf by migrating sandbars. These sands were transported in traction from deltaic headlands by seaward-deflected coastal/shelf currents. The sand formed thin (3-20 ft; 1-6 m) arcuate belts (shelf sand plumes) which were 17-20 mi (27-32 km) wide and extended 27-30 mi (43-48 km) downdrift and 21-40 mi (34-64 km) onto the shelf. Orientation of the long axes of ridges, formed by the stacking of individual bars within the shelf sand plume, changes (from dip to strike-oriented downdrift) corresponding to the flow directions of the shelf currents. Southwestward, fair-weather reworking of these delta-supplied sands by shelf currents resulted in the down-current stratigraphic climbing of the migrating shelf-bar complexes. Onshore stratigraphic climbing in the landward parts of the plume complexes was related to storm activity. Current patterns and the resulting distribution of sand were influenced by the configuration of the shelf and the topographic relief inherited from previously deposited deltaic/shelf depositional platforms. Three variations of the basic shelf sandstone-plume model were recognized in the study area: (1) a rapidly deposited, immature plume, (2) an abandoned, current-reworked plume, and (3) a storm-modified, onshore-reworked plume. Each of these variants displays unique characteristics which influence their potential as hydrocarbon reservoirs.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. Late quaternary geologic framework, north-central Gulf of Mexico

    USGS Publications Warehouse

    Kindinger, Jack G.; Penland, Shea; Williams, S. Jeffress; Brooks, Gregg R.; Suter, John R.; McBride, Randolph A.

    1991-01-01

    The geologic framework of the north-central Gulf of Mexico shelf is composed of multiple, stacked, delta systems. Shelf and nearshore sedimentary facies were deposited by deltaic progradation, followed by shoreface erosion and submergence. A variety of sedimentary facies has been identified, including prodelta, delta fringe, distributary, lagoonal, barrier island, and shelf sand sheet. This study is based on the interpretation and the synthesis of > 6,700 km of high-resolution seismic profiles, 75 grab samples, and 77 vibracores. The nearshore morphology, shallow stratigraphy, and sediment distribution of the eastern Louisiana shelf are the products of transgressive sedimentary processes reworking the abandoned St. Bernard delta complex. Relatively recent Mississippi delta lobe consists primarily of fine sand, silt, and clay. In the southern portion of the St. Bernard delta complex, asymmetrical sand ridges (>5 m relief) have formed as the result of marine reworking of distributary mouth-bar sands. Silty sediments from the modern Mississippi Birdsfoot delta onlap the St. Bernard delta complex along the southern edge. The distal margin of the St. Bernard complex is distinct and has a sharp contact on the north near the Mississippi Sound barrier island coastline and a late Wisconsinan delta to the south. The Chandeleur Islands and the barrier islands of Mississippi Sound have been formed by a combination of Holocene and Pleistocene fluvial processes, shoreface erosion, and ravinement of the exposed shelf. Sediments underlying the relatively thin Holocene sediment cover are relict fluvial sands, deposited during the late Wisconsinan lowstand. Subsequent relative sea-level rise allowed marine processes to rework and redistribute sediments that formed the nearshore fine-grained facies and the shelf sand sheet.

  12. 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.

  13. 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.

  14. 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.

  15. Microstructural and Chemical Reappraisal of Mineralogical Inheritance in Partially Molten Rocks: Implication for Fabric Resetting in Granitoids

    NASA Astrophysics Data System (ADS)

    Hasalova, P.; Schulmann, K.; Tabaud, A.; Verner, K.; Weinberg, R. F.

    2013-12-01

    During orogenic processes continental crust experience significant partial melting. Repeated thermal pulses or fluctuation in water content can even cause multiple anatectic events that result in complex intrusion suits. There are numerous studies regarding chronology of such intrusions or origin of the magmas. However, there is lack of microstructural characteristic of such remelting/infiltration processes. How do we distinguish the newly derived melt from the inherited magmatic crystals? What is the resulting microstructural appearance of such 'mixed' granite? And importantly how does new melt presence impact on fabric recorded in these granites? We investigate extensive granitoids complex in the Vosges Mountains in Eastern France. This complex reveal two main generations of magmatic rocks. The first event occurred at ca. 340Ma, is associated with extensive Mg-K magmatism and is related to building of thick orogenic root and subsequent exhumation of deep crust to shallower crustal levels. These granitoids intruded all crustal levels. The second magmatic event occurred at ca. 325 Ma and affected exclusively the mid-crustal level. This magmatic event produced large quantity of felsic anatectic melts which further pervasively intruded and compositionally and texturally reworked previously formed magmas. The detailed field and microstructural observations revealed a transition from granites that has been completely reworked by the infiltrated melt to granites that preserve former magmatic assemblage and have only incipient amount of the new melt. The new from melt crystallized material form narrow, fine-grained pathways along grain boundaries or cuts across pre-existing magmatic grains. With increasing amount of the newly crystallized material the original magmatic xenocrysts are resorbed and show highly corroded shapes. The early formed feldspar and quartz grains have strong compositional zoning, with cores reflecting original magmatic composition and rims showing

  16. 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.

  17. Low cost composite manufacturing utilizing intelligent pultrusion and resin transfer molding (IPRTM)

    NASA Astrophysics Data System (ADS)

    Bradley, James E.; Wysocki, Tadeusz S., Jr.

    1993-02-01

    This article describes an innovative method for the economical manufacturing of large, intricately-shaped tubular composite parts. Proprietary intelligent process control techniques are combined with standard pultrusion and RTM methodologies to provide high part throughput, performance, and quality while substantially reducing scrap, rework costs, and labor requirements. On-line process monitoring and control is achieved through a smart tooling interface consisting of modular zone tiles installed on part-specific die assemblies. Real-time archiving of process run parameters provides enhanced SPC and SQC capabilities.

  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. Depositional and surface exposure history of the Shorty Crater core 74001/2 - FMR and magnetic studies

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; Gose, W. A.; Lauer, H. V., Jr.

    1978-01-01

    Surface exposure (maturity) indices and concentrations of FeO and metallic iron were determined at 0.5-cm intervals of the Apollo 17 core section, which sampled a pyroclastic deposit on the rim of Shorty Crater. The determinations showed that all of the soil in the core is extremely immature. An exposure history of the core is proposed: accumulation (about 3.6 billion years ago), shallow burial (during the first 20 million years), deep burial (till about 10-15 million years ago), followed by excavation (10-15 million years ago), and in situ reworking (till the present).

  20. 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.

  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. 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.

  3. 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

  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. 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

  6. 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

  7. 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

  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. A statistical study of Mercurian crater classes applied to the emplacement of the intercrater plains

    NASA Technical Reports Server (NTRS)

    Woronow, Alex; Love, Karen

    1987-01-01

    Two principal processes have been invoked for emplacement of the intercrater plains: (1) basin ejecta and autochthonous surface materials reworked by that ejecta or (2) volcanic flows. A new approach was taken: the multivariate statistical analysis of crater class. The results of the analysis constrain the formative process of the intercrater plains units to have affected craters on both terrains in a similar manner. Any emplacement process brief in temporal extent (compared to the period of late heavy bombardment), such as emplacement of ejecta from a single event or a brief period of extensive volcanism, violates this constraint. This analysis is briefly discussed.

  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. Discovery of the most distal Ries tektites found in Lower Silesia, southwestern Poland

    NASA Astrophysics Data System (ADS)

    Brachaniec, Tomasz; Szopa, Krzysztof; Karwowski, ŁUkasz

    2014-08-01

    We report the first occurrence of moldavites in Poland. This discovery confirms the hypothesis that moldavites could have been distributed up to 500 km from the Ries crater in Germany. The tektites were reworked from Middle Miocene sediments and redeposited in Late Miocene (Pannonian) fluvial deposits of the Gozdnicka Formation in Lower Silesia. The Polish moldavites are represented by nine (<8 mm) fragments with a total of 0.471 g. The lack of the autochthonous tektites indicates that tektites investigated here had to be redeposited in a fluvial environment, probably from the Lusatian area. The chemical composition of the Polish moldavites plots in the same area with those from other localities.

  12. 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.

  13. 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.

  14. 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., Jr.; 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.

  15. Evaluation of temperatures attained by electronic components during various manual soldering operations

    NASA Astrophysics Data System (ADS)

    Dunn, B. D.; Hilbrands, G.; Nielsen, P. J.

    1983-03-01

    After component-failure analyses showed that defective spacecraft devices were overheated during soldering, it was verified that quality-assurance personnel omitted to control pretinning-bath and soldering iron temperatures, so data were acquired under controlled processing conditions. Component temperature rises were recorded during degolding, pretinning, soldering and the reworking of soldered joints. Results show that existing ESA specifications for manual soldering and repair ensure that the maximum temperature ratings ascribed to standard spacecraft components are not exceeded. Application of heat sinks to certain delicate components during degolding is essential, and it can be advantageous to apply them during pretinning and other soldering operations.

  16. A Computer-Assisted Interactive Treatment Planning System for Mental Health

    PubMed Central

    Hammond, Kenric W.; Munnecke, Thomas H.

    1981-01-01

    The authors describe a MUMPS based system capable of assisting clinicians in developing written psychiatric treatment plans in inpatient and outpatient services in a VA hospital. This interactive system relies upon a series of hierarchically arranged topical frames addressing a broad range of psychosocial and medical problems, treatment goals, and methods. It speeds multi-disciplinary treatment planning, employs objective language, serves an educational purpose, and structures hierarchically organized entry of detailed information into the data base. Significantly, this system is compatible with other MUMPS applications developed in the VA. Future modifications, expansions, and export of methodology can be accomplished without extensive reworking of existing software or data storage design.

  17. Earth Radiation Budget Experiment (ERBE) scanner instrument anomaly investigation

    NASA Technical Reports Server (NTRS)

    Watson, N. D.; Miller, J. B.; Taylor, L. V.; Lovell, J. B.; Cox, J. W.; Fedors, J. C.; Kopia, L. P.; Holloway, R. M.; Bradley, O. H.

    1985-01-01

    The results of an ad-hoc committee investigation of in-Earth orbit operational anomalies noted on two identical Earth Radiation Budget Experiment (ERBE) Scanner instruments on two different spacecraft busses is presented. The anomalies are attributed to the bearings and the lubrication scheme for the bearings. A detailed discussion of the pertinent instrument operations, the approach of the investigation team and the current status of the instruments now in Earth orbit is included. The team considered operational changes for these instruments, rework possibilities for the one instrument which is waiting to be launched, and preferable lubrication considerations for specific space operational requirements similar to those for the ERBE scanner bearings.

  18. 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.

  19. Kids with disabilities inspire a musical instrument

    ScienceCinema

    Daily, Dan; Pfeifer, Kent

    2014-02-10

    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.

  20. Robotic Tool Changer For Automated Welding

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L.; Spencer, Carl N.

    1994-01-01

    Prototype robotic tool changer for automated welding system eliminates need for most manual tool setups and attendant problems: operates rapidly, always chooses designated tool, maneuvers tip of welding torch or other tool in correct position, and reliably connects water, gas, welding wire, high-voltage electrical signals, and ground. Also loads tools other than those for welding. Intended for use in robotic work cell producing all good parts, no rejects. In production, robot welds part, tests for flaws, and reworks as necessary before releasing it.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Glossary of terms in heat transfer, fluid flow and related topics: English, Russian, German, French, and Japanese

    SciTech Connect

    Begell, W.

    1983-01-01

    The glossary defines terms used in the field of heat transfer. The English, French, and German terms in this glossary have been reworked and updated. A section of Japanese terms has also been provided. Terms covered are grouped into the following categories: (1) General Concepts; (2) Dimensional and Similarity Methods; (3) Heat Conduction; (4) Convective Heat Transfer in a Single-Phase Medium; (5) Convective Heat Transfer in Evaporation, Boiling, and Condensation; (6) Mass Transfer; and (7) Radiativae Heat Transfer. Alphabetical indexes of English,Russian, German, French, and Japanese terms are included.

  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. Structural and mechanical properties of heat-resistant granular nickel alloys

    SciTech Connect

    Eremenko, V.I.; Anoshkin, N.F.; Fatkullin, O.Kh.

    1992-05-01

    In order to realize the advantage afforded by granular metallurgy, it is necessary to know the laws of structure formation at every stage of the fabrication of semifinished products for heat-resistant nickel alloys. In this regard the structural features connected with the manufacture of granules by rapid cooling of a melt should be taken into account, as well as those related to the specific technological processes used in reworking (hot isostatic pressing - HIP) and heat treatment. 3 refs., 7 figs., 2 tabs.

  15. 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.

  16. A linear Hf isotope-age array despite different granitoid sources and complex Archean geodynamics: Example from the Pietersburg block (South Africa)

    NASA Astrophysics Data System (ADS)

    Laurent, Oscar; Zeh, Armin

    2015-11-01

    Combined U-Pb and Lu-Hf isotope data from zircon populations are widely used to constrain Hadean-Archean crustal evolution. Linear Hf isotope-age arrays are interpreted to reflect the protracted, internal reworking of crust derived from the (depleted) mantle during a short-lived magmatic event, and related 176Lu/177Hf ratios are used to constrain the composition of the reworked crustal reservoir. Results of this study, however, indicate that Hf isotope-age arrays can also result from complex geodynamic processes and crust-mantle interactions, as shown by U-Pb and Lu-Hf isotope analyses of zircons from well characterized granitoids of the Pietersburg Block (PB), northern Kaapvaal Craton (South Africa). Apart from scarce remnants of Paleoarchean crust, most granitoids of the PB with ages between 2.94 and 2.05 Ga (n = 32) define a straight Hf isotope-age array with low 176Lu/177Hf of 0.0022, although they show a wide compositional range, were derived from various sources and emplaced successively in different geodynamic settings. The crustal evolution occurred in five stages: (I) predominately mafic crust formation in an intra-oceanic environment (3.4-3.0 Ga); (II) voluminous TTG crust formation in an early accretionary orogen (3.0-2.92 Ga); (III) internal TTG crust reworking and subduction of TTG-derived sediments in an Andean-type setting (2.89-2.75 Ga); (IV) (post-)collisional high-K magmatism from both mantle and crustal sources (2.71-2.67 Ga); and (V) alkaline magmatism in an intra-cratonic environment (2.05-2.03 Ga). The inferred array results from voluminous TTG crust formation during stage II, and involvement of this crust during all subsequent stages by two different processes: (i) internal crust reworking through both partial melting and assimilation at 2.89-2.75 Ga, leading to the formation of biotite granites coeval with minor TTGs, and (ii) subduction of TTG-derived sediments underneath the PB, causing enrichment of the mantle that subsequently became

  17. Late Pleistocene Depositional Environments of the New Jersey Continental Shelf: Foraminiferal Evidence

    NASA Astrophysics Data System (ADS)

    Christensen, B. A.; Goff, J. A.; Alexander, C. R.; Austin, J. A.; Gulick, S. P.; Fulthorpe, C. S.; Nordfjord, S.; Sommerfield, C.; Venherm, C.; Schock, S.; Nielson, D. L.

    2003-12-01

    evaluate reworking. Samples have been analyzed both on and adjacent to features such as gravel lags, sand ridges, and erosion pits. Both the fauna and the mineralogy are varied and reflect the high degree of variability of surface morphology. Generally, the foraminiferal populations are bimodal, with an in situ component, and another assemblage of very abraded, reworked foraminifera. The mineralogy also reflects at least two populations and includes abundant clear angular quartz, and reworked rounded, frosted, often iron- stained quartz. The presence of lithic fragments, coupled with a variable lithology, together suggest that some of these grains may be ice rafted debris (IRD), although it is difficult to differentiate between reworked shelf sediments and IRD.

  18. 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

  19. 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.

  20. 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.

  1. Climate Change and Climate Modeling

    NASA Astrophysics Data System (ADS)

    Schmidt, Gavin

    2011-06-01

    In long-established fields like fluid mechanics or quantum theory, the contents of introductory textbooks are mostly predictable: The basics are covered in more or less the same order, and while cutting-edge research occasionally gets a look-in (depending on the inclinations of the authors), the contents are far more frequently reworkings of previous textbooks than a synthesis of recent primary literature. In a field like climate science, however, where there is a much shorter history of textbook writing, much of the subject matter is extracted directly from papers published in the past 10 years. This makes the resulting textbooks far more varied and interesting.

  2. 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.

  3. 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.

  4. '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. PMID:26254128

  5. Origin of the Mima Mounds, Thurston County region, Washington

    USGS Publications Warehouse

    Newcomb, R.C.

    1952-01-01

    There has been recent favorable consideration of the idea that the Mima mounds were made by gophers. The writer believes the evidence indicates that gophers function only in the reworking of the mound material, not in the primary construction. The plausibility of the earlier glacial or periglacial theory has been increased by recent knowledge of permafrost and of the deposits made by combined water and ice in cold climates. The gopher theory, as it has been applied to the Mima mounds, contains internal disharmonies and ignores significant field evidence supporting the earlier idea.

  6. 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

  7. Six Sigma and Lean concepts, a case study: patient centered care model for a mammography center.

    PubMed

    Viau, Mark; Southern, Becky

    2007-01-01

    Boca Raton Community Hospital in South Florida decided to increase return while enhancing patient experience and increasing staff morale. They implemented a program to pursue "enterprise excellence" through Six Sigma methodologies. In order to ensure the root causes to delays and rework were addressed, a multigenerational project plan with 3 major components was developed. Step 1: Stabilize; Step 2: Optimize; Step 3: Innovate. By including staff and process owners in the process, they are empowered to think differently about what they do and how they do it. A team that works collaboratively to identify problems and develop solutions can only be a positive to any organization. PMID:17983037

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. Quartz concentration as an index of sediment mixing: hydraulic mine-tailings in the Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Allan James, L.

    1991-06-01

    Hydraulic gold mining delivered large volumes of sediment to northern California stream channels from 1853 to 1884. Distinctive quartz compositions of this sediment allow development of a sediment mixing index for determination of tailings concentrations in contemporaneous and reworked deposits. This index reveals patterns of sediment mixing in the Bear River, California over the last 100 years. A conceptual model summarizes the nature of sediment mixing in the Bear River basin through time and space. High terrace sediment compositions suggest that hydraulic mining sediment was diluted by about 22% other alluvium as it moved more than 60 km to the Sacramento Valley. This substantial volume of other alluvium was introduced during the mining period by human activities in addition to hydraulic mining. Sediment compositions in modern low-flow channels indicate that most channel reaches within the mining districts remain dominated by tailings due to sustained reworking of stored alluvium. Tailings are substantially diluted downstream in modern channel deposits, however, due to trapping of sediment by dams and local erosion of Quarternary alluvium.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Biosteering - A biostratigraphic application to horizontal drilling in the Eldfisk field, Norwegian North Sea

    SciTech Connect

    Yang-Logan, L.C.; Tveit, R.; Bailey, H.W.

    1995-09-01

    Biosteering is an application of biostratigraphy that monitors drilling through and along the reservoir interval (horizontal section). Traditionally, biostratigraphy has provided information regarding the age, zonation, and paleoenvironment at the time of sediment deposition. This data can be used to identify and correlate a particular stratigraphic level. Wellsite biostratigraphic information can rapidly identify stratigraphic horizons. This information can then assist in steering the well through the reservoir, and predict anticipated sections ahead of the drill-bit. The primary target reservoir in Eldfisk Field is the upper part of the Tor Formation (TA layer). Prior to development drilling, a detailed biostratigraphic framework was established which provided sufficient stratigraphic resolution to identify the reservoir layers. This framework utilized micropaleontological and nannoplankton index species, reworked elements, changes in relative abundance, and assemblage associations. The age of the Tor to Ekofisk Formations ranges from late Campanian to early Paleocene Danian. Nine combined zones are recognized in the Tor to Ekofisk Formations. A number of allochthonous units are suggested in the Ekofisk Formation which represent the facies of reworking. The lowermost layer is generally missing. A total of five horizontal wells have been successfully drilled in the Eldfisk Field through January 1995. Although the original objective was to continuously remain in the upper part of the Tor Formation, local pinchouts and thinning hamper this effort in some wells. However, this biosteering technique is critical to drilling horizontal wells, and yet represents a minute portion of the total expenditure.

  5. 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

  6. 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

  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. 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. Post-glacial paleoenvironments of the Lake Winnebago basin, east central Wisconsin, based on ostracodes

    SciTech Connect

    Fielder, R.F.; Smith, G.L.; Fitzgerald, T.M. . Dept. of Geology)

    1994-04-01

    Ostracodes were used to determine post-glacial paleoenvironments of the Lake Winnebago Basin. Following the retreat of the Wisconsinian Green Bay Lobe, Glacial Lake Oshkosh was dammed behind the ice sheet. As the modern Fox River was established, Glacial Lake Oshkosh shrank to form modern Lake Winnebago. Ostracodes were sampled from four vibracores in attempts to correlate sedimentary units and determine paleoenvironments. The oldest unit identified in their vibracores is grayish red clay that is thought to be reworked glacial till that was deposited in a lacustrine setting. This clay is dominated by Candona rawsoni, an ostracod species that prefers cold and deep water. The broken and eroded carapaces of the C. rawsoni in the greyish-red clay suggest reworking and transport, perhaps from the Lake Superior Basin. The contact between the clay and overlying sediments is an erosional unconformity, overlain in some places by gravel. The clay is overlain by coarsening-upward from sandy-silt to medium-grained sand, suggesting a decrease in lake levels and water depths. Raised shorelines 20 and 60 ft above present lake level constitute the geomorphic evidence for higher lake levels. Offshore, at depths of ten to twenty feet, the sediment type above is an olive black organic-rich mud where juveniles of C. rawsoni are the dominant species.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. Influence of the Geotechnical Properties of Dacite Domes on the 1980 Failure of Mt. St. Helens

    NASA Astrophysics Data System (ADS)

    Katzenstein, K. W.; Watters, R. J.

    2003-12-01

    The largest historical rockslide-avalanche occurred on May 18th, 1980 as part of the eruption of Mt. St. Helens. The slide had a volume of approximately 2.8 km3, and decreased the elevation of the volcano by about 400 m. The flank collapse prompted a reappraisal of theories regarding volcano morphology, construction, and hazard assessment. Previous stability assessments of the volcano used small-scale (36 cm2) shear tests on the reworked avalanche deposits to obtain strength data. Our approach utilized strength data from 1) large (0.15 m2) and small-scale shear testing on reworked avalanche deposits, 2) uniaxial, triaxial and joint shear strength of collected in-situ samples of fractured domes and associated dykes, and 3) calculated or back - analyzed strength values of the 1980 cryptodome. Field investigations included collection of data from safe, accessible areas within the crater, breach and summit rim. Field mapping, photogrammetry, spatial correlation of geologic structures, and the collection of representative rock samples for the laboratory testing were accomplished. Laboratory strength data and rock mass characterization information were combined in order to obtain strength parameters for different failure scenarios. Once a simplified cross section of the volcano had been produced, strength values, earthquake loadings, and theorized pore pressures were inputted into a limit equilibrium stability program. The results show the crucial role that the highly fractured dacite domes in the northern portion of the volcano have in determining failure direction, and nature of the collapse.

  16. 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.

  17. NDI method to locate intergranular corrosion around fastener holes in aluminum wing skins

    NASA Astrophysics Data System (ADS)

    Rutherford, Paul S.

    1998-03-01

    Contact between galvanically dissimilar metals, such as cadmium plated steel fasteners and aluminum wing skins are known to be a source of corrosion. There is a design requirement to fill the void between the contacting surfaces of steel fasteners with a wet sealant. However, if the contacting surface is damaged or a void exists between the fastener head and the aluminum skin, moisture can collect and intergranular corrosion may occur along aluminum grain boundaries, which run parallel to the surface of the wing skin. If intergranular corrosion is allowed to propagate, delamination of the thin layers of aluminum, known as exfoliation corrosion will occur. When this intergranular corrosion reaches an exfoliated state, extensive rework is involved in removing the corrosion. This paper discusses the results of a USAF E-3A Engineering Service Task 89-E3B3-16 to develop a nondestructive inspection procedure to detect intergranular corrosion in an incipient state before it reaches exfoliation. Eddy current and ultrasonic inspection techniques were evaluated. A novel ultrasonic pulse echo technique was developed which utilizes a focus transducer with a hand held fixture. Inspections were performed on test parts which were removed from the upper wing skin of a retired 707 which had varying degrees of intergranular and exfoliation corrosion. Inspection results are compared to the results from the mechanical rework of the wing skin and dissection of a wing skin fastener hole.

  18. Recognizing seiche and tsunami effects in lake sediments

    NASA Astrophysics Data System (ADS)

    Marco, Shmuel; Alsop, Ian G.; Katz, Oded; Dray, Yehoshua

    2014-05-01

    The lacustrine 70-15-ka Lisan Formation outcropping around the Dead Sea contains superb examples of slump folds formed in water depths of <100 m. New structural data from individual horizons demonstrate that several of these gravity-driven slumps are coaxially refolded and reworked by folds and thrusts verging both back up and then down the palaeoslope. The uppermost folds are often truncated. A progressive increase in reworking and shearing is developed up through the folded sediment, culminating in an upward-finning breccia layer that is capped by a thin, typically graded horizon of undeformed fine-grained clasts. We interpret this sequence as a seiche-related deformation. Based on the similarity of the structures in the Lisan Formation and on additional supporting observations we interpret zigzag-shaped sand injections in artificial lake deposits on the Eastern Mediterranean shore as evidence for a tsunami, possibly associated with the earthquake of 25 November 1759. If this interpretation is correct it supports the hypothesis that onshore Dead Sea Fault earthquakes can trigger tsunamis in the Mediterranean.

  19. 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.

  20. Investigation on the effect of metallic impurity Zn in solvent during photolithography process

    NASA Astrophysics Data System (ADS)

    Jeon, Byoung-Tak; Kim, Ook-Hyun; Baik, Jeong-Heon; Ha, Jeong-Hyuk; Lee, Il-Ho; Yang, Weon-Sik

    2005-05-01

    The trend toward narrower line widths in the manufacture of integrated circuits has put an increasing burden on contamination control in every aspect of semiconductor fabrication. For a deep sub micrometer device, metal contamination appearing on the device can cause fatal problems including increasing the leakage current at the p-n junction, decreasing the breakdown voltage of oxide. Many lithographic defects have been known and evaluated, however, the effects of metallic impurity (Zn) in solvent are seldom reported during lithography process. Solvents are component material for Photoresist and have been used for prewet, strippers, EBR, rinse and so on during photolithography process. Lithography plays a very important role because it is applied repeatedly onto the wafer surface during device manufacturing. Unfortunately, pattern lifting happened to well formation layer wafers that were reworked on a normal iline litho process after stripping the Photoresist with solvent (PGMEA). We also detected blocked pattern defect at 0.18 CMOS gate pattern coated with DUV resist applied solvent prewet step after BARC coating. From various investigations, we could know that pattern lifting and blocked defect were derived from solvent (PGMEA). In this paper, we show mechanism of adhesion fails and blocked defect happened by metallic impurity Zn in solvent during solvent rework and prewet on organic BARC film. It shows that proper control of metallic impurities in thinner is an important item in FAB.

  1. 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

  2. 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.

  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. Air emission flux from contaminated dredged materials stored in a pilot-scale confined disposal facility.

    PubMed

    Ravikrishna, R; Valsaraj, K T; Reible, D D; Thibodeaux, L J; Price, C B; Brannon, J M; Meyers, T E; Yost, S

    2001-03-01

    A pilot-scale field simulation was conducted to estimate the air emissions from contaminated dredged material stored in a confined disposal facility (CDF). Contaminated dredged material with a variety of organic chemicals, obtained from Indiana Harbor Canal, was used in the study. It was placed in an outdoor CDF simulator (i.e., a lysimeter of dimensions 4 ft x 4 ft x 2 ft). A portable, dynamic flux chamber was used to periodically measure emissions of various polynuclear aromatic hydrocarbons (PAHs). A weather station was set up to monitor and record the meteorological conditions during the experiment. The fluxes of several PAHs were monitored over time for 6 1/2 months. Initial 6-hr average fluxes varied from 2 to 20 ng/cm2/hr for six different PAHs. The flux values declined rapidly for all compounds soon after placement of the dredged material in the CDE Chemical concentrations derived from flux values were generally of low magnitude compared with ambient standards. Data obtained from the experiment were compared against those predicted using models for air emissions. Model simulations showed that initially the flux was largely from exposed pore water from saturated (wet) sediment, whereas the long-term flux was controlled by diffusion through the pore air of the unsaturated sediment. Model predictions generally overestimated the measured emissions. A rainfall event was simulated, and the dredged material was reworked to simulate that typical of a CDF operation. Increased flux was observed upon reworking the dredged material. PMID:11266100

  5. (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.

  6. 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.

  7. A-type stratoid granites of Madagascar: evidence of Rodinia rifting at ca 790 Ma

    NASA Astrophysics Data System (ADS)

    Nedelec, Anne; Paquette, Jean-Louis; Bouchez, Jean-Luc

    2015-04-01

    The so-called stratoid granites are sheet-like granites emplaced as conformable sills in the Precambrian basement of central Madagascar. Most of them have A-type affinities (Nédélec et al. 1995). They are everywhere characterized by the same structural pattern evidencing two stages of deformation. The first one (foliations mildly dipping to the west and lineations trending WSW) is regarded as the consequence of synkinematic magma emplacement. The second stage, characterized by interference folds, steeply dipping foliations and subhorizontal lineations trending to the north, corresponds to a more or less pronounced reworking in ductile conditions, regarded as the result of Late Pan-African transcurrent tectonics. To the north of Antananarivo, the stratoid granites are associated with comagmatic quartz-syenites. New U-Pb zircons ages obtained by in situ analyses reveal two group of ages: upper intercept ages of ca 790 Ma, and younger ages of ca 550 Ma corresponding to crystal rims. These new data question the geological significance of former TIMS ages of ca 630 Ma formerly obtained from the same rocks (Paquette & Nédélec 1998). It is suggested that the stratoid granites and syenites were emplaced during a crustal thinning event corresponding to an early Rodinia rifting stage. The Pan-African imprint on these rocks is therefore limited to reheating, tectonic reworking and deep fluid transfer in the vicinity of Late-Neoproterozoic shear zones at ca 550 Ma (Nédélec et al. 2014).

  8. 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.

  9. 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.

  10. The geology, mineralogy and paragenesis of the Castrovirreyna lead-zinc-silver deposits, Peru

    USGS Publications Warehouse

    Lewis, Richard Wheatley, Jr.

    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

  11. 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

  12. 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

  13. 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

  14. 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

  15. Characterizing subaqueous co-seismic scarps using coeval specific sedimentary events; a case study in Lesser Antilles

    NASA Astrophysics Data System (ADS)

    Beck, C.; Reyss, J.; Feuillet, N.; Leclerc, F.; Moreno, E.

    2012-12-01

    Improvements of active fault surveying have shown that creep, or alternating creep and co-seismic displacements, are not rare. Nevertheless, either on land (trenching), or in subaqueous setting (seismic imaging and coring), active fault offsets, investigated for paleoseismic purpose, are sometimes assumed as co-seismic without direct evidences. At the opposite, within adequate sedimentary archives, some gravity reworking events may be attributed to earthquake triggering, but often do not permit to locate the responsible fault and the co-seismic rupture. In the here-discussed example, both types of observations could be associated: faulting offsets and specific sedimentary events "sealing" them. Several very high resolution (VHR) seismic profiles obtained during The GWADASEIS cruise (Lesser Antilles volcanic arc, February-March 2009) evidenced frequent "ponding" of reworked sediments in the deepest areas. These bodies are acoustically transparent (few ms t.w.t. thick) and often deposited on the hanging walls of dominantly normal faults, at the base of scarps, as previously observed along the North Anatolian Fault (Beck et al., 2007, doi:10.1016/j.sedgeo.2005.12.031). Their thicknesses appear sufficient to compensate (i.e. bury) successive offsets, resulting in a flat and horizontal sea floor through time. Offshore Montserrat and Nevis islands, piston coring (4 to 7 m long) was dedicated to characterize the most recent of these particular layers. An up to 2m-thick "homogenite" appears capping the RedOx water/sediment interface. 210Pb and 137Cs activities lack in the homogenite, while a normal unsupported 210Pb decrease profile and a 137Cs peak, corresponding to the Atmospheric Nuclear Experiments (1962), are present below (Beck et al. 2012, doi:10.5194/nhess-12-1-2012). This sedimentary event and the coeval scarp are post-1970 AD, and attributed either to the March 16th 1985 earthquake or to the October 8th 1974 one (respectively Mw6.3 and Mw7.4). Based on the

  16. Impact of polychaetes (Nereis spp. and Arenicola marina) on carbon biogeochemistry in coastal marine sediments†

    PubMed Central

    Kristensen, Erik

    2001-01-01

    Known effects of bioturbation by common polychaetes (Nereis spp. and Arenicola marina) in Northern European coastal waters on sediment carbon diagenesis is summarized and assessed. The physical impact of irrigation and reworking activity of the involved polychaete species is evaluated and related to their basic biology. Based on past and present experimental work, it is concluded that effects of bioturbation on carbon diagenesis from manipulated laboratory experiments cannot be directly extrapolated to in situ conditions. The 45–260% flux (e.g., CO2 release) enhancement found in the laboratory is much higher than usually observed in the field (10–25%). Thus, the faunal induced enhancement of microbial carbon oxidation in natural sediments instead causes a reduction of the organic matter inventory rather than an increased release of CO2 across the sediment/water interface. The relative decrease in organic inventory (Gb/Gu) is inversely related to the relative increase in microbial capacity for organic matter decay (kb/ku). The equilibrium is controlled by the balance between organic input (deposition of organic matter at the sediment surface) and the intensity of bioturbation. Introduction of oxygen to subsurface sediment and removal of metabolites are considered the two most important underlying mechanisms for the stimulation of carbon oxidation by burrowing fauna. Introduction of oxygen to deep sediment layers of low microbial activity, either by downward irrigation transport of overlying oxic water or by upward reworking transport of sediment to the oxic water column will increase carbon oxidation of anaerobically refractory organic matter. It appears that the irrigation effect is larger than and to a higher degree dependent on animal density than the reworking effect. Enhancement of anaerobic carbon oxidation by removal of metabolites (reduced diffusion scale) may cause a significant increase in total sediment metabolism. This is caused by three possible

  17. 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

  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. 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

  20. 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

  1. 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

  2. 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

  3. At the Cratonic Crossroads: A geochronologic and geochemical perspective on the Little Rocky Mountains, Montana

    NASA Astrophysics Data System (ADS)

    Gifford, J. N.; Mueller, P. A.; Foster, D. A.; Mogk, D. W.

    2012-12-01

    The Medicine Hat Block (MHB) is a poorly constrained structural element in the Paleoproterozoic amalgamation of Laurentia. It lies between the Wyoming and Hearne cratons along the northern margin of the Great Falls Tectonic Zone. The block was caught between the Hearne and Wyoming cratons during the Paleoproterozoic closure of an ocean and subsequent continental collision. The majority of the MHB is concealed by younger material, and it is recognized primarily by its seismic signature and its influence on the geochemistry of younger igneous rocks. The MHB appears to be composed of Archean (2.6-3.1 Ga) and Proterozoic (1.75 Ga) continental crust based on limited data from drill holes and xenoliths. The Little Rocky Mountains (LRM) are the only potential exposure of Precambrian basement rocks in the northeastern GFTZ, and represent unique surface exposure of the MHB. The LRM is cored by a dome-shaped Tertiary syenite intrusion, with Precambrian metamorphic units exposed along the margins of the dome. Limited previous geochronology from the LRM includes K/Ar ages of 1.7-1.75 Ga and a Rb/Sr age of c. 2.55 Ga from a quartzofeldspathic paragneisses. These data leave the affinity of the LRM uncertain, either representing reworked Archean crust and/or Paleoproterozoic material generated during the subduction of oceanic lithosphere and formation of the GFTZ. New U/Pb ages of zircons from the Precambrian meta-igneous rocks in the LRM range from 2.2 - 3.3 Ga, with prominent peaks between 2.6 - 2.8 Ga. Outliers clustering around 1.7 - 1.8 Ga are rare and likely reflect Paleoproterozoic reworking of older material. These ages are consistent with a MHB affinity for the LRM. Pb-isotope data define a 3.1 Ga model age, which suggests some influence of older Wyoming Craton or MHB crust. The dominance of 2.6-2.8 Ga U/Pb ages suggests that the Paleoproterozoic igneous arc was constructed on pre-existing MHB crust. Models for reconciling the high angle junction between the GFTZ and

  4. A re-evaluation of the Pleistocene deposits of ODP Site 987 - implications for the behavior of the Scoresby Sund sector of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Sverre Laberg, Jan; Forwick, Matthias; Husum, Katrine

    2013-04-01

    In order to understand past and current dynamics of the Greenland Ice Sheet, it is essential to obtain detailed reconstructions of the natural fluctuations of the ice sheet on longer time scales. This study aims to improve our knowledge of the Greenland Ice Sheet dynamics in the Scoresby Sund sector during the Pleistocene, hence we have re-visited Unit I of Holes 987D and E of Ocean Drilling Program Leg 162 (Shipboard Scientific Party, 1996). Unit I comprises three main lithological facies: (i) mud with color banding characterized by horizontal - semi-horizontal boundaries and scattered clasts inferred to be glacimarine and marine deposits; (ii) mud with sharp color changes, irregular boundaries, clay clasts/lenses, scattered clasts and no color banding, indicating reworking of facies (i), i.e. muddy debris flow deposits; and (iii) sand lamina/layers mostly comprising fine sand, sharp upper and lower boundaries interpreted to be turbidites. These facies have also been identified by the Shipboard Scientific Party (1996) but no detailed follow-up studies of their distribution have been undertaken to our knowledge. The results of this study show that facies (i) dominate the succession deposited between ~2.14 - 0.99 Ma. The interval shows only few signs of reworking. Generally thin sandy turbidites are rare, but they are occasionally more abundant in a few tens of cm thick intervals. The abundance of sandy turbidites increases markedly about 0.99 Ma. Throughout most of the overlying interval they are associated with muddy debris-flow deposits representing facies (ii) and, thus, this part of Hole 987D is inferred to be dominated by reworked deposits. We attribute the pronounced change at ~0.99 Ma to higher sediment input from the upper slope related to the repeated presence of the grounded ice at the shelf break. This could indicate that the Greenland Ice Sheet in the Scoresby Sund area reached the shelf break more frequently during the past 1 Ma as compared to the ~2

  5. 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.

  6. Effects of sequence stratigraphy on distribution of Cambro-Ordovician siliciclastic hydrocarbon reservoirs in Michigan basin

    SciTech Connect

    Horne, J.C.; Reel, C.L.; Cummins, G.D. )

    1989-08-01

    The lateral and vertical distribution of Cambrian-Ordovician siliciclastic reservoir-potential rock types in the Michigan basin is governed by the sequence stratigraphy. The sequence stratigraphy is controlled primarily by the interaction of four variables: subsidence, eustasy, volume of sediments, and climate. Seven sequential stratigraphic intervals can be defined in the pre-Utica, Cambrian-Ordovician deposits of the Michigan basin. Each of these unconformity-bounded sequences begins with a siliciclastic unit deposited over a lowstand surface of erosion. These lowstand surfaces developed during periods when eustatic sea level decline exceeded the rate of subsidence in the basin, and much or all of the basin became exposed. Where the sedimentation rate was less than the sum of the rate of subsidence and sea level change, a transgressive sequence developed with more open-marine carbonates overlying shallower water and/or non-marine facies. Reservoir-potential siliciclastics accumulated in incised valley-fill and transgressive reworked deposits.

  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. Titan's Xanadu region: Geomorphology and formation scenario

    NASA Astrophysics Data System (ADS)

    Langhans, Migrjam; Lunine, Jonathan I.; Mitri, Giuseppe

    2013-04-01

    Based on comprehensive mapping of the region, the recent theories of Xanadu's origin are examined and a chronology of geologic processes is proposed. The geologic history of Titan's Xanadu region is different from that of the other surface units on Saturn's moon. A previously proposed origin of western Xanadu from a giant impact in the early history of the moon is difficult to confirm given the scarcity of morphologic indications of an impact basin. The basic topographic structure of the landscape is controlled by tectonic processes that date back to the early history of Titan. More recently, the surface is intensely reworked and resurfaced by fluvial processes, which seem to have leveled out and compensated height differences. Although the surface age seems young at first view, the underlying processes that created this surface and the topographic structure appear to be ancient.

  9. Comprehensive Monitoring for Heterogeneous Geographically Distributed Storage

    NASA Astrophysics Data System (ADS)

    Ratnikova, N.; Karavakis, E.; Lammel, S.; Wildish, T.

    2015-12-01

    Storage capacity at CMS Tier-1 and Tier-2 sites reached over 100 Petabytes in 2014, and will be substantially increased during Run 2 data taking. The allocation of storage for the individual users analysis data, which is not accounted as a centrally managed storage space, will be increased to up to 40%. For comprehensive tracking and monitoring of the storage utilization across all participating sites, CMS developed a space monitoring system, which provides a central view of the geographically dispersed heterogeneous storage systems. The first prototype was deployed at pilot sites in summer 2014, and has been substantially reworked since then. In this paper we discuss the functionality and our experience of system deployment and operation on the full CMS scale.

  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. Eastern Sahara Geology from Orbital Radar: Potential Analog to Mars

    NASA Technical Reports Server (NTRS)

    Farr, T. G.; Paillou, P.; Heggy, E.

    2004-01-01

    Much of the surface of Mars has been intensely reworked by aeolian processes and key evidence about the history of the Martian environment seems to be hidden beneath a widespread layer of debris (paleo lakes and rivers, faults, impact craters). In the same way, the recent geological and hydrological history of the eastern Sahara is still mainly hidden under large regions of wind-blown sand which represent a possible terrestrial analog to Mars. The subsurface geology there is generally invisible to optical remote sensing techniques, but radar images obtained from the Shuttle Imaging Radar (SIR) missions were able to penetrate the superficial sand layer to reveal parts of paleohydrological networks in southern Egypt.

  12. Microstructure, Defects, and Reliability of Mixed Pb-Free/Sn-Pb Assemblies

    NASA Astrophysics Data System (ADS)

    Snugovsky, Polina; McCormick, Heather; Bagheri, Simin; Bagheri, Zohreh; Hamilton, Craig; Romansky, Marianne

    2009-02-01

    The results of an intensive reliability study on Pb-free ball grid array (BGA)/Sn-Pb solder assemblies as well as some lessons learnt dealing with mixed assembly production at Celestica are described in this paper. In the reliability study, four types of Pb-free ball grid array components were assembled on test vehicles using the Sn-Pb eutectic solder and typical Sn-Pb reflow profiles with 205°C to 220°C peak temperatures. Accelerated thermal cycling (ATC) was conducted at 0°C to 100°C. The influence of the microstructure on Weibull plot parameters and the failure mode will be shown. Interconnect defects such as nonuniform phase distribution, low-melting structure accumulation, and void formation are discussed. Recommendations on mixed assembly and rework parameters are given.

  13. 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.

  14. 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.

  15. ALMA band 3 cartridge maintenance plan

    NASA Astrophysics Data System (ADS)

    Yeung, Keith; Seifried, Kerry; Randolph, William

    2012-09-01

    Under the "Memorandum of Understanding between the National Radio Astronomy Observatory (NRAO)/Associated Universities Incorporated (AUI), Herzberg Institute of Astrophysics (HIA) and the University of Calgary related to Canadian ALMA Construction Phase Work Packages", HIA is committed to deliver a suite of seventy-three Band 3 100 GHz receiver cartridges to the ALMA Project. After the acceptance of each cartridge at the Front End Integration Centers, HIA is responsible to perform any post-delivery maintenance, repair or rework of the cartridges for a warranty period of up to one year. This paper defines a framework for the maintenance and repair services for the Band 3 cartridges after the post-delivery warranty period has expired.

  16. Cretaceous pollen in Pliocene rocks: implications for Pliocene climate in the southwestern United States

    USGS Publications Warehouse

    Fleming, R.F.

    1994-01-01

    Pliocene rocks of the Imperial and Palm Spring Formations in southern California contain reworked Cretaceous pollen that helps determine the timing of erosion of Cretaceous rocks on the Colorado Plateau. The stratigraphic distribution of the pollen suggests that erosion of Cretaceous rocks in the southern part of the Colorado Plateau began by 4.5 Ma, and in the northern part of the plateau at 3.9 Ma. This erosional history indicates that rapid and extensive erosion of the Colorado Plateau occurred during the Pliocene and supports the hypothesis that much of the Grand Canyon was cut during the Pliocene, rather than earlier in the Tertiary. Rapid erosion and transport from the Colorado Plateau require the climate in that region during the Pliocene to have been significantly wetter than it is today. -from Author

  17. 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

  18. A learning curve-based method to implement multifunctional work teams in the Brazilian footwear sector.

    PubMed

    Guimarães, L B de M; Anzanello, M J; Renner, J S

    2012-05-01

    This paper presents a method for implementing multifunctional work teams in a footwear company that followed the Taylor/Ford system for decades. The suggested framework first applies a Learning Curve (LC) modeling to assess whether rotation between tasks of different complexities affects workers' learning rate and performance. Next, the Macroergonomic Work Analysis (MA) method (Guimarães, 1999, 2009) introduces multifunctional principles in work teams towards workers' training and resources improvement. When applied to a pilot line consisting of 100 workers, the intervention-reduced work related accidents in 80%, absenteeism in 45.65%, and eliminated work related musculoskeletal disorders (WMSD), medical consultations, and turnover. Further, the output rate of the multifunctional team increased average 3% compared to the production rate of the regular lines following the Taylor/Ford system (with the same shoe model being manufactured), while the rework and spoilage rates were reduced 85% and 69%, respectively. PMID:21907970

  19. DE-Sovietizing educational systems, learning from past policy and practice

    NASA Astrophysics Data System (ADS)

    Kaufman, Cathy C.

    1994-03-01

    All 21st century societies face the dilemma of reforming educational systems to meet changing social demands. In order to enable new beginnings to be made, this article examines the ending of reform efforts in the former Soviet Union immediately prior to the establishment of the Commonwealth of Independent States. Educational policy had followed a shifting course under changing Soviet leadership, much supposed reform consisting of little more than reworked statements of intent. In the second half of the 1980's, more serious attempts were made to raise enrollment of six-year olds, to upgrade instructional materials and teaching quality, and to redesign vocational education. Inadequate facilities and resources, lack of trained personnel, promotion on non-educational grounds, economic hardship and bureaucratic resistance hindered these reforms. As successor states to the Soviet Union — and others — face structural change, knowledge of why certain reforms were previously resisted will help future planning.

  20. Assessment of Intelligent Processing Equipment in the National Aeronautics and Space Administration, 1991

    NASA Technical Reports Server (NTRS)

    Jones, C. S.

    1992-01-01

    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.

  1. Driving degradation within biodegradable polymers with embedded nanoparticles

    NASA Astrophysics Data System (ADS)

    Gorga, Russell; Firestone, Gabriel; Fontecha, Daniela; Bochinski, Jason; Clarke, Laura

    The ability to controllably trigger breaking of chemical bonds enables a substance that has robust material properties during use but can be re-worked or deteriorated upon command. Photothermal heating creates intense local heat at isolated nanoparticle locations within a sample and can result in very different material responses than those achievable with conventional (uniform) heating. In this process, irradiation with visible light resonant with the nanoparticle's surface plasmon resonance results in dramatic local heating of the particles and the surrounding material. This work studies intentional thermal degradation of poly ethyl cyanoacrylate-starch composites doped with metal nanoparticles, and explores differences in degradation speed, efficiency, and resultant mechanical properties when heated via the photothermal effect. This work was supported by the National Science Foundation, Grant #: CMMI-1462966.

  2. 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.

  3. 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.

  4. Rethinking Social Recovery in Schizophrenia: What A Capabilities Approach Might Offer

    PubMed Central

    Hopper, Kim

    2007-01-01

    Resurgent hopes for recovery from schizophrenia in the late 1980s had less to do with fresh empirical evidence than with focused political agitation. Recovery's promise was transformative: reworking traditional power relationships, conferring distinctive expertise on service users, rewriting the mandate of public mental health systems. Its institutional imprint is considerably weaker. This article takes sympathetic measure of that outcome and provides an alternative framework for what recovery might mean, one drawn from disability studies and Sen's capabilities approach. By re-enfranchising agency, redressing material and symbolic disadvantage, raising the bar on fundamental entitlements and claiming institutional support for complex competencies, a capabilities approach could convert flaccid doctrine into useful guidelines and tools for public mental health. PMID:17499900

  5. Epidemics and the politics of knowledge: contested narratives in Egypt's H1N1 response.

    PubMed

    Leach, Melissa; Tadros, Mariz

    2014-01-01

    This article explores the politics of knowledge involved in understanding and responding to epidemics in an era of global health governance and biosecurity. It develops and applies an approach focused on how multiple, competing narratives about epidemics are constructed, mobilized and interact, and selectively justify pathways of intervention and response. A detailed ethnographic case study of national and local responses to H1N1 influenza, so-called swine flu, in Egypt reveals how global narratives were reworked by powerful actors in a particular political context, suppressing and delegitimizing the alternative narratives of the Zabaleen (Coptic Christian) people whose lives and livelihoods centered on raising pigs and working with them to control urban waste. The case study illustrates important ways in which geographies and politics of blame around epidemics emerge and are justified, their political contexts and consequences, and how they may feed back to shape the dynamics of disease itself. PMID:24761977

  6. Origin of the earth's ocean basins

    NASA Technical Reports Server (NTRS)

    Frey, H.

    1977-01-01

    The earth's original ocean basins are proposed to be mare-type basins produced 4 billion y.a. by the flux of asteroid-sized objects responsible for the lunar mare basins. Scaling upward from the observed number of lunar basins for the greater capture cross-section and impact velocity of the earth indicates that at least 50% of an original global crust would have been converted to basin topography. These basins were flooded by basaltic liquids in times short compared to the isostatic adjustment time for the basin. The modern crustal dichotomy (60% oceanic, 40% continental crust) was established early in the history of the earth, making possible the later onset of plate tectonic processes. These later processes have subsequently reworked, in several cycles, principally the oceanic parts of the earth's crust, changing the configuration of the continents in the process. Ocean basins (and oceans themselves) may be rare occurrences on planets in other star systems.

  7. The HWVP availability simulation model

    SciTech Connect

    Reisdorf, J.; Sienko, F.; Melville, D.; Gogg, T.

    1994-12-31

    This report described the hanford Waste Vitrification Plant simualtion model (HWVP).The model was utilized to simulate the performance and repair of remote handling equipment utilizied at the vitrification plant. The simulation model demonstrates that the HWVP has an availability of {approx} 85%. It also shows that both the MC and CDC cranes have a high utilization factor of {approx} 70%. This means that the crane`s idle time of {approx} 30% may not be sufficient to meet off-normal events such as canister rework. A study is recommended to optimize the crane operations in these areas. The ST/ET crane`s utilization factor is 16%, indicating that it can meet upset conditions. The analysis also shows that the canyon crane has a utilization factor of 29%, or it is idle 61% of the time. This large amount of inactive time demonstrates that the crane can service failed equipment without affecting production.

  8. Effects of Aerospace MACT Standard on coating operations at DoD facilities

    SciTech Connect

    Pelton, D.J.; Narayanan, R.

    1997-12-31

    DoD facilities that are a major source of HAPs and that manufacture, repair or rework any aerospace vehicle will have to contend with the aerospace National Emission Standard for Hazardous Air Pollutants (NESHAP). The rule which becomes effective September 1, 1998 requires reductions in volatile organic compounds (VOC) and organic hazardous air pollutants (HAP). Reductions will be achieved by use of primers and topcoats that meet regulatory limits for VOC or organic HAP or using air pollution control systems. At some DoD facilities preparations have been made to comply with the standard when the standard is in effect. The requirements of 40 CFR Part 63 Subpart GG (aerospace NESHAP) are briefly summarized. The impacts that have been experienced at an Air Force base that is currently practicing most of the NESHAP requirements in order to comply with existing state requirements are discussed.

  9. 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.

  10. Smart substrates: Making multi-chip modules smarter

    NASA Astrophysics Data System (ADS)

    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.

  11. How postcapping put Kuwait`s wells back onstream

    SciTech Connect

    Wilson, D.

    1994-01-01

    In late february 1991, the retreating Iraqi army blew up, or otherwise caused to blowout, some 700 wells in Kuwait. Between March and November, all of the fires were extinguished and the wells were capped. Work began in July 1991 to recomplete the damaged wells with replaced or reworked tubulars and well heads so that production could be resumed. Except for some of the earlier-capped wells into which cement was pumped, thus requiring more extensive downhole work, many of the damaged wells, particularly in Burgan field, were put back into production mode by the procedure described here, which became known as postcapping. This paper describes the equipment and techniques used in postcapping damaged wellheads.

  12. A process-based model for the partitioning of soluble, suspended particulate and bed sediment fractions of plutonium and caesium in the eastern Irish Sea.

    PubMed

    Vives I Batlle, J; Bryan, S; McDonald, P

    2008-01-01

    A dynamic model of plutonium behaviour in the marine environment has been developed, representing the oxidation state distribution and partitioning of plutonium between the soluble, colloidal, suspended particulate and seabed sediment fractions. With simple re-parameterisation, this model can also be applied to (137)Cs. The model, which is calibrated and validated against field data, has been used to predict concentrations of Pu(alpha) and (137)Cs in both water and seabed sediments from the vicinity of the Sellafield Ltd. reprocessing plant in Cumbria, UK. The model predicts that sediment reworking and transport are the key environmental processes as the Sellafield Pu(alpha) and (137)Cs discharge continues to decline. Inventory calculations generated by the model are consistent with previous estimations. For a hypothetical post-discharge scenario, the concentrations of these radionuclides in both seawater and surface sediments are predicted to decrease sharply, concurrent with a downward vertical migration of the activity retained in sediments. PMID:17719705

  13. Petrology of dune sand derived from basalt on the Ka'u Desert, Hawaii

    NASA Technical Reports Server (NTRS)

    Gooding, J. L.

    1982-01-01

    Dune sand from the Ka'u Desert, southwest flank of Kilauea volcano, Hawaii, is moderately well-sorted (median = 1.60 Phi, deviation = 0.60, skewness = 0.25, kurtosis = 0.68) and composed mostly of frosted subangular particles of basalt glass ('unfractionated' olivine-normative tholeitte), olivine, lithic fragments (subophitic and intersertal basalts; magnetite-ilmenite-rich basalts), reticular basalt glass, magnetite, ilmenite, and plagioclase, in approximately that order of abundance. Quantitative lithological comparison of the dune sand with sand-sized ash from the Keanakakoi Formation supports suggestions that the dune sand was derived largely from Keanakakoi ash. The dune sand is too well sorted to have been emplaced in its present form by base-surge but could have evolved by post-eruption reworking of the ash.

  14. Origin of the earth's ocean basins

    NASA Technical Reports Server (NTRS)

    Frex, H.

    1977-01-01

    The earth's original ocean basins were mare-type basins produced 4 billion years ago by the flux of asteroid-sized objects responsible for the lunar mare basins. Scaling upwards from the observed number of lunar basins for the greater capture cross-section and impact velocity of the Earth indicates that at least 50 percent of an original global crust would have been converted to basin topography. These basins were flooded by basaltic liquids in times short compared to the isostatic adjustment time for the basin. The modern crustal dichotomy (60 percent oceanic, 40 percent continental crust) was established early in the history of the earth, making possible the later onset of plate tectonic processes. These later processes have subsequently reworked, in several cycles, principally the oceanic parts of the earth's crust, changing the configuration of the continents in the process. Ocean basins (and oceans themselves) may be rare occurrences on planets in other star systems.

  15. Incorporating CCSDS telemetry standards and philosophy on Cassini

    NASA Technical Reports Server (NTRS)

    Day, John C.; Elson, Anne B.

    1995-01-01

    The Cassini project at the Jet Propulsion Laboratory (JPL) is implementing a spacecraft telemetry system based on the Consultative Committee for Space Data Systems (CCSDS) packet telemetry standards. Resolving the CCSDS concepts with a Ground Data System designed to handle time-division-multiplexed telemetry and also handling constraints unique to a deep-space planetary spacecraft (such as fixed downlink opportunities, small downlink rates and requirements for on-board data storage) have resulted in spacecraft and ground system design challenges. Solving these design challenges involved adapting and extending the CCSDS telemetry standards as well as changes to the spacecraft and ground system designs. The resulting spacecraft/ground system design is an example of how new ideas and philosophies can be incorporated into existing systems and design approaches without requiring significant rework. In addition, it shows that the CCSDS telemetry standards can be successfully applied to deep-space planetary spacecraft.

  16. Test What You Fly?

    NASA Technical Reports Server (NTRS)

    Margolies, Don

    2002-01-01

    It was the first time on any NASA project I know of that all the instruments on an observatory came off for rework or calibration after the full range of environmental tests, and then were reintegrated at the launch center without the benefit of an observatory environmental retest. Perhaps you've heard the expression, 'Test what you fly, fly what you test'? In theory, it's hard to argue with that. In this case, I was willing to take the risk of not testing what I flew. As the project manager for the Advanced Composition Explorer (ACE) mission, I was the one who ultimately decided what risks to take, just as it was my responsibility to get buy-in from the stakeholders.

  17. 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.

  18. Chemostratigraphy and Fe Mineralogy of the Victoria Crater Duck Bay Section: Opportunity APXS and Moessbauer Results

    NASA Technical Reports Server (NTRS)

    Mittlefehldt, D. W.; Schroeder, C.; Gellert, R.; Klingelhoefer, G.; Jolliff, B. L.; Morris, R. V.

    2008-01-01

    Meridiani Planum is a vast plain of approximately horizontally bedded sedimentary rocks composed of mixed and reworked basaltic and evaporitic sands containing secondary, diagenetic minerals [e.g., 1-5]. Because bedding planes are subparallel to topography, investigation of contiguous stratigraphy requires examining exposures in impact craters. Early in the mission (sols 130-317), Opportunity was commanded to do detailed study of exposed outcrops in Endurance crater, including the contiguous Karatepe section at the point of ingress. Just over 1000 sols later and roughly 7 km to the south, the rover is being commanded to do a similar study of the Duck Bay section of Victoria crater. Here we report on the preliminary results from the Alpha Particle X-ray Spectrometer (APXS) and Moessbauer instruments.

  19. 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).

  20. Venus geology

    NASA Astrophysics Data System (ADS)

    McLaughlin, W. I.

    1991-05-01

    The Magellan mission to Venus is reviewed. The scientific investigations conducted by 243-day cycles encompass mapping with a constant incidence angle for the radar, observing surface changes from one cycle to the next, and targeting young-looking volcanos. The topography of Venus is defined by the upper boundary of the crust and upwelling from lower domains. Tectonic features such as rift zones, linear mountain belts, ridge belts, and tesserae are described. The zones of tesserae are unique to the planet. Volcanism accounts for about 80 percent of the observed surface, the remainder being volcanic deposits which have been reworked by tectonism or impacts. Magellan data reveal about 900 impact craters with flow-like ejecta resulting from the fall of meteoroids. It is concluded that the age of the Venusian surface varies between 0 and 800 million years. Tectonic and volcanic activities dominate the formation of the Venus topography; such processes as weathering and erosion are relatively unimportant on Venus.

  1. Managing Communication among Geographically Distributed Teams: A Brazilian Case

    NASA Astrophysics Data System (ADS)

    Almeida, Ana Carina M.; de Farias Junior, Ivaldir H.; de S. Carneiro, Pedro Jorge

    The growing demand for qualified professionals is making software companies opt for distributed software development (DSD). At the project conception, communication and synchronization of information are critical factors for success. However problems such as time-zone difference between teams, culture, language and different development processes among sites could difficult the communication among teams. In this way, the main goal of this paper is to describe the solution adopted by a Brazilian team to improve communication in a multisite project environment. The purposed solution was based on the best practices described in the literature, and the communication plan was created based on the infrastructure needed by the project. The outcome of this work is to minimize the impact of communication issues in multisite projects, increasing productivity, good understanding and avoiding rework on code and document writing.

  2. 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.

  3. Thermal properties of explosives. Quarterly report, April--June 1964

    SciTech Connect

    Myers, L.C.

    1997-09-01

    Changes in the loading technique for the Henkin test to be used when investigating high temperatures explosives are reported. Data comparing times-to-explosion for lead, aluminum {open_quotes}foil{close_quotes}, insulated lead, and insulated aluminum {open_quotes}foil{close_quotes} plugs are included. A preliminary temperature-time curve for an HMX sample in the Henkin batch at 272{degrees}C, is reported. The pyrolysis apparatus has been reworked to increase its sensitivity and the results of the changes are readily apparent in the pyrolytic decomposition curves that are reported. Thermal data are reported for some {open_quotes}tailormade{close_quotes} samples of HMX, samples of PETN from different manufacturers, and the six simulated samples of Bridgewater HMX. Differences within these groups are detected by one or another of the tests. Work has begun on a two column gas chromatograph to be used in obtaining chemical reactivity data for use in specifications.

  4. Multi-storey calcrete profiles developed during the initial stages of the configuration of the Ebro Basin's exorrheic fluvial network

    NASA Astrophysics Data System (ADS)

    Meléndez, Alfonso; Alonso-Zarza, Ana M.; Sancho, Carlos

    2011-11-01

    Multi-storey calcrete profiles developed in the Quaternary on strath terraces of the Cinca and Alcanadre rivers, tributaries of the Ebro River in NE Spain. Two calcrete profiles (Tor 1 and Tor 2) near the village of El Tormillo show horizons with an arrangement that differs from that of commonly described calcrete profiles. Significant lateral changes occur in these profiles within a distance of less than 200 m, reflecting their pedofacies relationship. The Tor 1 profile on terrace Qt1 (the highest and oldest) consists of six horizons (from bottom to top): 1) coarse fluvial gravels; 2) mudstones with carbonate nodules; 3) a chalky horizon; 4) laminar horizons, including one peloidal horizon; 5) a multi-storey horizon formed of at least six minor sequences, each of which includes a lower detrital layer, a pisolithic horizon, and a thin discontinuous laminar horizon (these sequences indicate several cycles of brecciation and/or reworking); and 6) a topmost laminar and brecciated horizon also including reworked pisoliths. Some 200 m to the north of Tor 1, horizon 5 undergoes a lateral change to channel fill-deposits. The infill of the channels shows a fining-upwards sequence ranging from clasts of about 10 cm in diameter to red silts with sparse pebbles. All the clasts come from the underlying calcrete horizons. Laminar horizons are interbedded with the clastic channel deposits. The youngest calcrete profiles developed on terrace Qt3 of the Cinca River and on the Qp4 and Qp6 mantled pediment levels. All show relatively simple profiles composed mostly of lower horizons of coated gravels, with thin laminar horizons at the top. Most of the horizons, especially the laminar ones, show biogenic features such as alveolar septal structures, calcified filaments, biofilms, spherulites, micropores and needle-like calcite crystals. These features indicate the important role of vegetation in the formation of all the above profiles. The interbedding of clastic sediments and

  5. 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.

  6. 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. PMID:22022715

  7. 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

  8. Preserved Flora and Organics in Impact Melt Breccias

    NASA Technical Reports Server (NTRS)

    Schultz, P. H.; Harris, R. Scott; Clemett, S. J.; Thomas-Keprta, K. L.; Zarate, M.

    2014-01-01

    At least seven glass-bearing strata of varying ages occur at different horizons in the Pampean sediments of Argentina dating back to the Miocene. In a strict sense, these impact glasses are melt-matrix breccias composed of partially digested minerals clasts and basement fragments indicative of crater excavation. Ar-40/Ar-39 dating yield ages (+/- 2 sigma) of 6 +/- 2 Ka, 114 +/- 26 Ka, 230 +/- 30 Ka, 445 +/- 21 Ka, 3.27 +/- 0.08 Ma (near Mar del Plata = MdP), 5.28 +/- 0.04 Ma, and 9.21 +/- 0.08 Ma (near Chasico = CH) Where found in place (not reworked), these ages are consistent with the local stratigraphy and faunal assemblages. A striking property of some of these impact glasses is the encapsulation of preserved fragments of floral (and even soft-tissue faunal remains). Here we identify retained organics and describe a likely process of encapsulation and preservation.

  9. Effect of nano-coated stencil on ultra-fine pitch printing

    NASA Astrophysics Data System (ADS)

    Hoogar, Sharan

    The growing demand for compact handheld devices with increased functionality has posed new challenges to the electronics board assembly industry. The introduction of ultra-fine pitch components has elevated importance of the stencil printing process. The stencil printing process has been attributed to more than 50 percent of the total defects in Level 2 electronics assemblies as noted in many prior studies [Clouthier, 1997]. Achieving a good print can drastically reduce overall defects and rework costs. One of the major factors for a "good" print is the paste transfer efficiency (TE). TE is defined as the ratio of measured paste volume to the theoretical volume of the stencil aperture. The latest stencil technology available for ultra-fine pitch printing is the introduction of "nano-coated stencils". In this study, we will investigate the claim that a nano-coated stencil has better transfer efficiency than standard laser cut and electroformed stencils that lack this coating.

  10. Productive lower Wilcox distributary channel sands of Hallettsville embayment, Lavaca County, Texas

    SciTech Connect

    Chuber, S.; Howell, H.H.

    1986-09-01

    Whole-core petrographic and micropaleontological analyses from four wells and subsurface studies in three new fields of the Hallettsville area define a heretofore unsuspected deltaic suite of facies in the lower Wilcox. Massive distributary channel sands up to 250 ft thick are interbedded with overbank silts and shales as well as marsh, crevasse-splay, and natural levee sediments. Sparse microfauna indicate a restricted marine, shallow neritic, or nonmarine facies with reworked Cretaceous forms. Three channels have been productive to date: the Renger and Golsch (gas bearing) and the Hathaway (oil bearing). Even with dipmeter, whole-core, and abundant seismic data available, the narrow, sinuous channel sands are difficult to locate. Once penetrated, however, the sands produce either oil or condensate-rich gas in copious amounts.

  11. Control of surface defects on plasma-MIG hybrid welds in cryogenic aluminum alloys

    NASA Astrophysics Data System (ADS)

    Lee, Hee-Keun; Chun, Kwang-San; Park, Sang-Hyeon; Kang, Chung-Yun

    2015-07-01

    Lately, high production rate welding processes for Al alloys, which are used as LNG FPSO cargo containment system material, have been developed to overcome the limit of installation and high rework rates. In particular, plasma-metal inert gas (MIG) hybrid (PMH) welding can be used to obtain a higher deposition rate and lower porosity, while facilitating a cleaning effect by preheating and post heating the wire and the base metal. However, an asymmetric undercut and a black-colored deposit are created on the surface of PMH weld in Al alloys. For controlling the surface defect formation, the wire feeding speed and nozzle diameter in the PMH weld was investigated through arc phenomena with high-speed imaging and metallurgical analysis.

  12. 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

  13. Middle pleistocene interglacial sediments at Tye green, Stansted Airport, Essex, England

    NASA Astrophysics Data System (ADS)

    Boreham, S.; Field, M. H.; Gibbard, P. L.

    1999-05-01

    Interglacial lake deposits at Tye Green, Stansted, resting on unweathered till and overlain by a weathered diamicton are correlated with the temperate Hoxnian Stage. The sediments represent the infilling of an isolated kettle-hole type of lake basin formed at the end of the cold Anglian Stage. Through the temperate period this basin was infilled by inorganic and organic sediments that record the development and decline of deciduous forest. Later periglacial conditions are indicated by the final infilling of the basin by reworked till. The sedimentary sequence and vegetational development recorded in the sediments at Tye Green are compared with other Hoxnian sites in eastern England. Changes in deposition rates are interpreted as representing water-table fluctuations resulting from changes in precipitation. The deposits at Tye Green provide a useful stratigraphical marker in the glacial sequence of the district.

  14. Sr, Nd, Pb Isotope geochemistry and magma evolution of the potassic volcanic rocks, Wudalianchi, Northeast China

    USGS Publications Warehouse

    Junwen, W.; Guanghong, X.; Tatsumoto, M.; Basu, A.R.

    1989-01-01

    Wudalianchi volcanic rocks are the most typical Cenozoic potassic volcanic rocks in eastern China. Compositional comparisons between whole rocks and glasses of various occurrences indicate that the magma tends to become rich in silica and alkalis as a result of crystal differentiation in the course of evolution. They are unique in isotopic composition with more radiogenic Sr but less radiogenic Pb.87Sr /86 Sr is higher and143Nd/144Nd is lower than the undifferentiated global values. In comparison to continental potash volcanic rocks, Pb isotopes are apparently lower. These various threads of evidence indicate that the rocks were derived from a primary enriched mantle which had not been subjected to reworking and shows no sign of incorporation of crustal material. The correlation between Pb and Sr suggests the regional heterogeneity in the upper mantle in terms of chemical composition. ?? 1989 Institute of Geochemistry, Chinese Academy of Sciences.

  15. 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.

  16. 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

  17. 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

  18. The small schools movement: implications for health education.

    PubMed

    Cleary, Michael; English, Gary

    2005-09-01

    Approximately 70% of American high schools enroll 1000 or more students each, while almost one half of high schools enroll more than 1500 students each. A growing body of evidence, however, is showing that small schools, especially small secondary schools, result in positive benefits for students, families, and communities that go beyond letter grades. Investigators have found that smaller high schools result in greater academic achievement, higher faculty morale, less student misbehavior, and greater family satisfaction. Recommended strategies to create a more personalized high school experience and improve performance include creating smaller "schools" within large schools, instituting career academies, reworking the school day, and employing teacher advisory systems. This article describes the prominent elements of effective small schools with implications for a strengthened "presence" of the coordinated school health program at the high school level. PMID:16102086

  19. Soft-sediment deformation within seismogenic slumps of the Dead Sea Basin

    NASA Astrophysics Data System (ADS)

    Alsop, G. I.; Marco, Shmuel

    2011-04-01

    The Late Pleistocene Lisan Formation preserved next to the Dead Sea provides exceptional 3-D exposures of folds and faults generated during soft-sediment slumping and deformation. It is possible to generate a range of four different scenarios associated with overprinting in a single slump event. The progressive evolution of slump systems may be broadly categorised into initiation, translation, cessation, relaxation and compaction phases. Thrust packages typically define piggyback sequences during slump translation, with back-steepening of imbricate faults leading to collapse of folds back up the regional palaeoslope. Detailed evaluation of slumped horizons may also permit structures to be traced across apparently separate and distinct slumped units. The recognition that slumps may be reworked by younger seismically-triggered events suggests that in some cases the seismic recurrence interval may be shorter than previously anticipated.

  20. Transport-induced abrasion of fossil reptilian teeth: Implications for the existence of Tertiary dinosaurs in the Hell Creek Formation, Montana

    NASA Astrophysics Data System (ADS)

    Argast, Scott; Farlow, James O.; Gabet, Rose M.; Brinkman, Daniel L.

    1987-10-01

    The experimental transport-induced abrasion of five fossil teeth from a crocodilian and the tyrannosaurid dinosaur Albertosaurus demonstrates that enamel-coated teeth are minimally affected by abrasion associated with sediment-transport processes. After the equivalent of 360 480 km of transport, two teeth showed slight loss of weight, scratches were developed on the surface of one tooth, there were slight enlargements of the areas between adjacent serrations of one tooth, and a pit in the exposed dentine of one tooth was abraded smooth. These changes would have been difficult to recognize if the teeth had not been examined before the start of the experiment. Our results suggest that dinosaur teeth are abraded so slowly by transport processes that they provide equivocal evidence for limited transport and reworking.