WorldWideScience

Sample records for barrier island deposits

  1. Annotated bibliography of selected references on shoreline barrier island deposits with emphasis on Patrick Draw Field, Sweetwater County, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Rawn-Schatzinger, V.; Schatzinger, R.A.

    1993-07-01

    This bibliography contains 290 annotated references on barrier island and associated depositional environments and reservoirs. It is not an exhaustive compilation of all references on the subject, but rather selected papers on barrier islands, and the depositional processes of formation. Papers that examine the morphology and internal architecture of barrier island deposits, exploration and development technologies are emphasized. Papers were selected that aid in understanding reservoir architecture and engineering technologies to help maximize recovery efficiency from barrier island oil reservoirs. Barrier islands from Wyoming, Montana and the Rocky Mountains basins are extensively covered.

  2. The complex influences of back-barrier deposition, substrate slope and underlying stratigraphy in barrier island response to sea-level rise: Insights from the Virginia Barrier Islands, Mid-Atlantic Bight, U.S.A.

    Science.gov (United States)

    Brenner, Owen T.; Moore, Laura J.; Murray, A. Brad

    2015-10-01

    To understand the relative importance of back barrier environment, substrate slope and underlying stratigraphy in determining barrier island response to RSLR (relative sea-level rise), we use a morphological-behavior model (GEOMBEST) to conduct a series of sensitivity experiments, based on late-Holocene hindcast simulations of an island in the U.S. mid-Atlantic Bight (Metompkin Island, VA) having both salt marsh and lagoonal back-barrier environments, and we draw comparisons between these results and future simulations (2000-2100 AD) of island response to RSLR. Sensitivity analyses indicate that, as a whole, the island is highly sensitive to factors that reduce overall sand availability (i.e., high sand-loss rates and substrates containing little sand). Results also indicate that for all predicted future RSLR scenarios tested, islands having high substrate sand proportions (if allowed to migrate freely) will likely remain subaerial for centuries because of sufficient substrate sand supply and elevation to assist in keeping islands above sea level. Simulation results also lead to basic insights regarding the interactions among substrate slope, back-barrier deposition and island migration rates. In contrast to previous studies, which suggest that changes in substrate slope directly affect the island migration trajectory, we find that-in the presence of back-barrier deposition-the connection between substrate slope and island behavior is modulated (i.e., variability in migration rates is dampened) by changes in back-barrier width. These interactions-which tend to produce changes in shoreface sand content-lead to a negative feedback when the back-barrier deposit contains less sand than the underlying layer, resulting in a stable back-barrier width. Alternatively, a positive feedback arises when the back-barrier deposit contains more sand than the underlying layer, resulting in either back-barrier disappearance or perpetual widening.

  3. Luminescence dating of Holocene sedimentary deposits on Rømø, a barrier island in the Wadden Sea, Denmark

    DEFF Research Database (Denmark)

    Madsen, Anni Tindahl; Murray, Andrew S.; Andersen, Thorbjørn Joest;

    2010-01-01

    This study presents an Optically Stimulated Luminescence (OSL) based chronology for the evolution of the barrier island Rømø and related back-barrier lagoon deposits in the Danish Wadden Sea. The chronology is constructed using 78 quartz OSL ages obtained using a Single Aliquot Regenerative dose...... (SAR) protocol; samples were retrieved from seven sediment cores, each up to 25 m long, taken from locations on the island and within the back-barrier lagoon. The reliability of the OSL results is assessed using preheat plateaus, thermal transfer tests, and dose recovery measurements, and by comparison...... expanded towards the west, north and south as a result of an abundant sediment supply. Luminescence dating is concluded to be well-suited for establishing precise and accurate chronologies for barrier island deposits, and the technique has provided an excellent basis for the reconstruction of barrier...

  4. Morphodynamics of the Wadden Sea and its barrier island system

    NARCIS (Netherlands)

    Wang, Z.B.; Hoekstra, P.; Burchard, H.; Ridderinkhof, H.; Swart, H.E. de; Stive, M.J.F.

    2012-01-01

    The Wadden Sea and its associated barrier island system exhibit highly dynamic behaviour. Of major concern is the movement of water and air and the transport, erosion and deposition of sand and mud. These processes result in an ever-changing morphology (topography/bathymetry) of the islands, tidal c

  5. Nephtyidae (Annelida: Phyllodocida) of Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Murray, Anna; Wong, Eunice; Hutchings, Pat

    2015-01-01

    Seven species of the family Nephtyidae are recorded from Lizard Island, none previously reported from the Great Barrier Reef. Two species of Aglaophamus, four species of Micronephthys, one new and one previously unreported from Australia, and one species of Nephtys, were identified from samples collected during the Lizard Island Polychaete Workshop 2013, as well as from ecological studies undertaken during the 1970s and deposited in the Australian Museum marine invertebrate Collections. A dichotomous key to aid identification of these species newly reported from Lizard Island is provided. PMID:26624076

  6. Storm impacts on small barrier islands

    DEFF Research Database (Denmark)

    Kroon, Aart; Fruergaard, Mikkel

    changes in this evolution due to changes in the climate and associated sea levels. We analyzed the morphologic evolution of a series of barrier islands over the last decades using maps, aerial photographs and satellite images. This decadal morphologic evolution was coupled to the frequency and intensity...... of the local extreme events. The characterization of the extreme events was based on the joint probability of the extreme water levels and storm waves for the specific sites. The predicted climate change for the Danish waters will lead to higher water levels and an increase of the overwashes on the......The shorelines of the Baltic Sea and the inner coastal waters in Denmark consist of many barrier islands. These sandy barrier islands were mainly formed in the Holocene and are still very dynamic. The present day changes in the morphology are dominantly governed by storm waves and associated high...

  7. Estuarine Shoreline and Barrier-Island Sandline Change Assessment Dataset

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Barrier Island and Estuarine Wetland Physical Change Assessment Dataset was created to calibrate and test probability models of barrier island sandline and...

  8. 13 CFR 120.175 - Coastal barrier islands.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Coastal barrier islands. 120.175... Applying to All Business Loans Requirements Imposed Under Other Laws and Orders § 120.175 Coastal barrier islands. SBA and Intermediaries may not make or guarantee any loan within the Coastal Barrier...

  9. Barrier island arcs along abandoned Mississippi River deltas

    Science.gov (United States)

    Penland, S.; Suter, J.R.; Boyd, Ron

    1985-01-01

    Generation of transgressive barrier island arcs along the Mississippi River delta plain and preservation of barrier shoreline facies in their retreat paths on the inner shelf is controlled by: (1) shoreface translation; (2) age of the transgression; and (3) the thickness of the barrier island arc sediment package. Barrier island arcs experience an average relative sea level rise of 0.50-1.00 cm yr-1 and shoreface retreat rates range from 5-15 m yr-1. Young barrier island arc sediment packages (Isles Dernieres) are thin and have experienced limited landward retreat of the shoreface. Older barrier island arcs (Chandeleur Islands) are thicker and have experienced significant landward movement of the shoreface because of the greater time available for retreat. If the transgressed barrier shoreline sediment package lies above the advancing ravinement surface, the entire sequence is truncated. A thin reworked sand sheet marks the shoreface retreat path. The base of the transgressive sediment package can lie below the ravinement surface in older barrier shorelines. In this setting, the superstructure of the barrier shoreline is truncated, leaving the basal portion of the transgressive sequence preserved on the inner shelf. A variety of transgressive stratigraphic sequences from sand sheets to truncated barrier islands to sand-filled tidal inlet scars have been identified by high resolution seismic profiling across the shoreface retreat paths of Mississippi delta barrier island arcs. One of these examples, the Isles Dernieres, represents a recently detached barrier island arc in the early stages of transgression. An older example, the Chandeleur Islands, represents a barrier island arc experiencing long-term shoreface retreat. This paper describes the stratigraphic character and preserved transgressive facies for the Isles Dernieres and Chandeleur Islands. ?? 1985.

  10. Contrasting styles of Hurricane Irene washover sedimentation on three east coast barrier islands: Cape Lookout, North Carolina; Assateague Island, Virginia; and Fire Island, New York

    Science.gov (United States)

    Williams, H. F. L.

    2015-02-01

    Storm surge and wind-driven waves generated by Hurricane Irene, which made landfall on the U.S. east coast on August 27 2011, resulted in overwash of sandy barrier islands from North Carolina to New York State. Overwash has significant impacts on barrier island geomorphology: it represents a sediment pathway into island interiors, a component of island sediment budgets, and can cause considerable aggradation of backshore surfaces, important for potentially offsetting the effects of rising sea level. This study describes the morphology, texture and microfossil content of Hurricane Irene washover deposits at three contrasting barrier island sites: Cape Lookout, North Carolina, Assateague Island, Virginia and Fire Island, New York. At all three sites, run-up overwash occurred, wherein waves were sufficient to overtop parts of the beach system and transport sediment inland. However, at Fire Island, overwash was restricted by a higher elevational threshold to low spots in the beach system coinciding with pre-existing breaches in foredunes. The result was the formation of isolated, thinner, low-volume washover fans. At Assateague Island and Cape Lookout, lower elevational thresholds allowed waves to overtop longer continuous sections of beach systems, resulting in the formation of laterally-continuous, thicker, larger-volume washover terraces. Overall, the deposits lacked consistent trends in thickness and texture (such as thinning and fining inland, reflecting a progressive reduction in overwash competence). Thickness and texture of the deposits were both spatially variable and probably reflect infilling of low points on the former surface and the influence of beach and foredune sediment sources. All the washover deposits were essentially barren of foraminiferal microfossils, supporting the textural evidence that the adjacent beach and foredunes were the predominant sediment sources.

  11. Seismic stratigraphy of barrier-island arc retreat paths in Mississippi River delta

    Energy Technology Data Exchange (ETDEWEB)

    Penland, S.; Suter, J.R.

    1983-09-01

    The stratigraphic record preserved in the retreat path of Mississippi delta barrier-island arcs is controlled by erosional shoreface retreat processes, relative sea level rise, and sediment supply. More than 500 km (300 mi) of high resolution shallow seismic profiles correlated with vibracores from retreat paths fronting the Isles Dernieres and Chandeleur barrier-island arcs, show contrasting stratigraphic sequences preserved on the inner continental shelf (Mississippian delta). The Isles Dernieres barrier-island arc developed as a consequence of the Caillou Headland abandonment in the early Lafourche delta approximately 800 years B.P. On the lower shoreface, channels can be seen projecting seaward under the central part of the island arc; associated with it is a beach-ridge plain extending eastward. On the inner shelf, a sand sheet up to 60 cm (2 ft) thick marks the retreat path of the Isles Dernieres. The Chandeleur barrier-island arc was generated by abandonment of the St. Bernard delta complex 1,500 years ago. Scattered outcrops of shell reefs and lagoonal deposits occur on the lower shoreface. Beyond the shoreface, a 1 to 5 m (3 to 16 ft) thick sand sheet, caps tidal inlet scars up to 10 m (33 ft) thick, as well as the basal portions of migrating barrier-island sequences associated with earlier shoreline positions. Differences seen in the two stratigraphic sequences are a function of distributary size and depositional history of each barrier-island arc. The Isles Dernieres developed from a series of small sand-deficient distributaries in the Lafourche delta complex, whereas the Chandeleur Islands developed from large sand-rich distributaries of the St. Bernard delta complex.

  12. How a barrier island may react on a sea-level rise: The Holocene to Recent Rømø barrier island, Danish Wadden Sea

    DEFF Research Database (Denmark)

    Johannessen, Peter N.; Nielsen, Lars H.; Møller, Ingelise;

    set up the water level increases considerably and the highest measured water level is 4.9 m above mean sea level. The barrier island is c. 14 km long and c. 4 km wide and is separated from the mainland by a c. 8 km wide lagoon. At the northern and southern parts of the island, tidal inlets occur with......The Rømø barrier island is situated in the northern part of the European Wadden Sea. It has been intensively studied on the basis of recent depositional systems and morphology, seven 25 m long sediment cores, 35 km ground penetrating radar (GPR) reflection profiles with a maximum signal penetration...... a width of 400–1000 m and depths of 7–30 m. Salt marsh areas, up to 2 km wide, are fringing the lagoonal coast of the island. Active eastward migrating aeolian dunes cover large parts of the island. The Rømø barrier island system is a very sand rich system as it receives coast parallel transported...

  13. EAARL Coastal Topography--Northeast Barrier Islands 2007: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first surface elevation map (also known as a Digital Elevation Model, or DEM) of the northeast coastal barrier islands in New York and New Jersey was produced...

  14. EAARL Coastal Topography--Northeast Barrier Islands 2007: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the northeast coastal barrier islands in New York and New Jersey was produced from...

  15. A comprehensive sediment budget for the Mississippi Barrier Islands

    NARCIS (Netherlands)

    Walstra, D.J.R.; De Vroeg, J.H.; Van Thiel de Vries, J.S.M.; Swinkels, C.; Luijendijk, A.P.; De Boer, W.P.; Hoekstra, R.; Hoonhout, B.; Henrotte, J.; Smolders, T.; Dekker, F.; Godsey, E.

    2012-01-01

    In order to conceive any realistic plan for post-Katrina island restoration, it is necessary to understand the physical processes that move sand along the littoral drift zone off the coast of Mississippi. This littoral zone influences the character of the Mississippi barrier islands as they exist in

  16. Refining the link between the Holocene development of the Mississippi River Delta and the geologic evolution of Cat Island, MS: implications for delta-associated barrier islands

    Science.gov (United States)

    Miselis, Jennifer L.; Buster, Noreen A.; Kindinger, Jack G.

    2014-01-01

    The geologic evolution of barrier islands is profoundly influenced by the nature of the deposits underlying them. Many researchers have speculated on the origin and evolution of Cat Island in Mississippi, but uncertainty remains about whether or not the island is underlain completely or in part by deposits associated with the past growth of the Mississippi River delta. In part, this is due to a lack of comprehensive geological information offshore of the island that could augment previous stratigraphic interpretations based on terrestrial borings. An extensive survey of Cat Island and its surrounding waters was conducted, including shallow-water geophysics (e.g., high-resolution chirp seismic, side-scan sonar, and swath and single-beam bathymetry) and both terrestrial and marine vibracoring. High-resolution seismic data and vibracores from south and east of the island show two horizontally laminated silt units; marine radiocarbon dates indicate that they are St. Bernard delta complex (SBDC) deposits. Furthermore, seismic data reveal that the SBDC deposits taper off toward the southern shoreline of Cat Island and to the west, morphology consistent with the distal edge of a delta complex. The sedimentology and extent of each unit suggest that the lower unit may have been deposited during an earlier period of continuous river flow while the upper unit may represent reduced or sporadic river flow. OSL dates from the island platform (beneath beach ridge complexes) indicate three stages of terrestrial evolution: island emergence resulting from relative sea-level rise (~ 5400 ybp) island aggradation via littoral transport (~ 2500–4000 ybp) and island degradation due to delta-mediated changes in wave direction (present– ~ 3600 ybp). Finally, the combination of terrestrial and marine data shows that portions of Cat Island that are lower in elevation than the central part of the island are younger and are likely underlain by a thin layer of deltaic sediments. This

  17. Barrier island vulnerability to breaching: a case study on Dauphin Island, Alabama

    Science.gov (United States)

    Hansen, Mark; Sallenger, Asbury H.

    2007-01-01

    Breaching of barrier islands can adversely impact society by severing infrastructure, destroying private properties, and altering water quality in back bays and estuaries. This study provides a scheme that assesses the relative vulnerability of a barrier island to breach during storms. Dauphin Island, Alabama was selected for this study because it has a well documented history of island breaches and extensive geological and geomorphic data. To assess the vulnerability of the island, we defined several variables contributing to the risk of breaching: island geology, breaching history, and island topography and geomorphology. These variables were combined to form a breaching index (BI) value for cross island computational bins, each bin every 50 m in the alongshore direction. Results suggest the eastern section of Dauphin Island has the lowest risk of breaching with the remaining portion of the island having a moderate to high risk of breaching. Two reaches in the western section of the island were found to be particularly vulnerable due primarily to their minimal cross-sectional dimensions.

  18. Emergent Behavior of Coupled Barrier Island - Resort Systems

    Science.gov (United States)

    McNamara, D. E.; Werner, B. T.

    2004-12-01

    Barrier islands are attractive sites for resorts. Natural barrier islands experience beach erosion and island overwash during storms, beach accretion and dune building during inter-storm periods, and migration up the continental shelf as sea level rises. Beach replenishment, artificial dune building, seawalls, jetties and groins have been somewhat effective in protecting resorts against erosion and overwash during storms, but it is unknown how the coupled system will respond to long-term sea level rise. We investigate coupled barrier island - resort systems using an agent-based model with three components: natural barrier islands divided into a series of alongshore cells; resorts controlled by markets for tourism and hotel purchases; and coupling via storm damage to resorts and resort protection by government agents. Modeled barrier islands change by beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms. In the resort hotel market, developer agents build hotels and hotel owning agents purchase them using predictions of future revenue and property appreciation, with the goal of maximizing discounted utility. In the tourism market, hotel owning agents set room rental prices to maximize profit and tourist agents choose vacation destinations maximizing a utility based on beach width, price and word-of-mouth. Government agents build seawalls, groins and jetties, and widen the beach and build up dunes by adding sand to protect resorts from storms, enhance beach quality, and maximize resort revenue. Results indicate that barrier islands and resorts evolve in a coupled manner to resort size saturation, with resorts protected against small-to-intermediate-scale storms under fairly stable sea level. Under extended, rapidly rising sea level, protection measures enhance the effect of large storms, leading to emergent behavior in the form of limit cycles or barrier submergence

  19. Morphologic and Process Transformation at a Barrier Island of Taiwan

    Science.gov (United States)

    Lin, T.

    2006-12-01

    Waisanding Barrier, the largest barrier island off the southwestern coast of Taiwan, has undergone morphologic and process transformation in recent decades. Based on the analysis of historical maps and aerial photographs, the island has migrated both southward and eastward (or landward). The shoreline at the northwest tip of the island has a retreat rate at 65 m/year, and the shoreline at the southern end migrates at a speed of 88 m/year southeastward. The overall land area has shrunken. Topographic profile surveys also show the great reduction of dune fields and the dune heights. This is mainly due to the starvation of sand sources. Three main processes have been proposed to explain the island migration: (1) the southward- dominant longshore drift; (2) the overwash process; and (3) the prevailing southward aeolian sand transport. Choushui river, the largest river in Taiwan, is the major sediment source for the Waisanding Barrier. Improvement constructions and illegal sand/gravel mining of the river may reduce large amounts of sediments that reach the shore. An artificial industrial park project located at the south of Choushui river mouth may also play an important role in blocking and preventing some of the southward longshore sand transport from reaching Waisanding Barrier. A permanent loss of sand to a submarine channel at the southern end had probably worsened the sediment storage of the barrier island. The strong wind transport during winter and the overwash process during spring high tides or stormy conditions may reduce the foredune and overall elevation of the island. This landform modification may result in the increase of overwash frequencies that move more sand landward and lower the elevation. As the results, the original back shore and dune field area are developed into a wide sandy tidal flat with many shallow tidal creeks formed during rising high tide stages. Because of all the landform changes in recent decades, the barrier island may undergo the

  20. The Role of Backbarrier Filling in the Evolution of a Barrier Island System

    Science.gov (United States)

    Hein, C. J.; Fitzgerald, D. M.; Stone, B. D.; Carruthers, E.; Gontz, A. M.

    2009-12-01

    Barrier islands develop through a variety of processes, including spit accretion, barrier elongation, breaching and inlet filling. New geophysical and sedimentological data collected along a barrier system in the western Gulf of Maine provide a means of documenting a unique process of barrier evolution involving backbarrier infilling and ensuing closure of an ancient tidal inlet. Plum Island is located along a mixed-energy, tide-dominated coastline bounded by estuaries and backed by an extensive system of salt marsh and tidal creeks. Following the regional glacioisostatic lowstand of approximately -45 m at 12 ka, the Holocene transgression reworked a late Pleistocene regressive braid plain and lowstand delta. Sediments driven onshore during the transgression and derived from the Merrimack River fed the developing barrier system. Radiocarbon dates suggests that backbarrier sands began accumulating at the modern site of Plum Island at approximately 9 ka. At this time, the barrier was composed of several discrete islands separated by inlets and situated offshore of modern Plum Island. Shallow seismic and ground penetrating radar (GPR) data confirm the existence of lower stand riverine/tidal channels extending onto the shallow shelf. Coincident with the slowing of relative sea level rise, Plum Island began to form in its current location approximately 5.5 ka, establishing its modern form by about 2.5 ka. Sediment cores and GPR data demonstrate that the barrier lithosome is 5 to 15 m thick and evolved through initial aggradation followed by southerly spit accretion and progradation. The discovery of a multiple inlet channel system reoccupying the area carved by the lowstand Parker River indicates that central Plum Island underwent a complex developmental history. Cores through the inlet sequence consist of fine to medium sand with repetitive interbedded coarse sand units, marking high-energy depositional events associated with spit accretion and displacement of the

  1. Control of barrier island shape by inlet sediment bypassing: East Frisian Islands, West Germany

    Science.gov (United States)

    FitzGerald, D.M.; Penland, S.; Nummedal, D.

    1984-01-01

    A study of the East Frisian Islands has shown that the plan form of these islands can be explained by processes of inlet sediment bypassing. This island chain is located on a high wave energy, high tide range shoreline where the average deep-water significant wave height exceeds 1.0 m and the spring tidal range varies from 2.7 m at Juist to 2.9 m at Wangerooge. An abundant sediment supply and a strong eastward component of wave power (4.4 ?? 103 W m-1) have caused a persistent eastward growth of the barrier islands. The eastward extension of the barriers has been accommodated more by inlet narrowing, than by inlet migration. It is estimated from morphological evidence that a minimum of 2.7 ?? 105 m3 of sand is delivered to the inlets each year via the easterly longshore transport system. Much of this sand ultimately bypasses the inlets in the form of large, migrating swash bars. The location where the swash bars attach to the beach is controlled by the amount of overlap of the ebb-tidal delta along the downdrift inlet shoreline. The configuration of the ebbtidal delta, in turn, is a function of inlet size and position of the main ebb channel. The swash bar welding process has caused preferential beach nourishment and historical shoreline progradation. Along the East Frisian Islands this process has produced barrier islands with humpbacked, bulbous updrift and bulbous downdrift shapes. The model of barrier island development presented in this paper not only explains well the configuration of the German barriers but also the morphology of barriers along many other mixed energy coasts. ?? 1984.

  2. Methanotrophy controls groundwater methane export from a barrier island

    Science.gov (United States)

    Schutte, Charles A.; Wilson, Alicia M.; Evans, Tyler; Moore, Willard S.; Joye, Samantha B.

    2016-04-01

    Methane concentrations can be high in coastal groundwater, resulting in methane export driven by submarine groundwater discharge. However, the magnitude of this methane flux depends significantly on the rate of methanotrophy, the often overlooked process of microbial methane consumption that occurs within coastal aquifer sediments. Here we describe a zone of methanogenesis within the freshwater lens of a barrier island aquifer and investigate the methane source/sink behavior of the barrier island system as a whole. The median concentration of methane dissolved in fresh groundwater beneath the center of the island was 0.6 mM, supported by high rates of potential methanogenesis (22 mmol m-2 day-1). However, rates of microbial methane consumption were also elevated in surrounding sediments (18 mmol m-2 day-1). Groundwater flowing from the zone of methanogenesis to the point of discharge into the ocean had a long residence time within methanotrophic sediments (∼195 days) such that the majority of the methane produced within the barrier island aquifer was likely consumed there.

  3. Integrating ground-penetrating radar and borehole data from a Wadden Sea barrier island

    DEFF Research Database (Denmark)

    Nielsen, Lars; Møller, I.; Nielsen, L. H.;

    2009-01-01

    Sea level rise may have large implications for low-gradient barrier coastal systems. This problem motivated an integrated ground-penetrating radar (GPR) and sedimentological study of the Rømø Wadden Sea barrier island. Crossing W-E and N-S-oriented 100 MHz GPR reflection profiles with a total...... length of about 30 km were acquired on the island. In this case study, we process and analyze GPR data and investigate the feasibility of using integrated GPR and sedimentological log data to constrain spatial variations in lithology, structures and changing depositional environments of the Rømø barrier...... conversion of the reflection profiles. The GPR reflections are correlated with sedimentological facies logs, and we test to which extent it is possible to map the architecture of different sedimentary units of the Rømø barrier island based on joint interpretation of the GPR and core data. Detailed...

  4. Variations in barrier-island evolution at millennial and decadal time scales related to underlying geology, Onslow Beach, NC USA

    Science.gov (United States)

    Yu, W.; Hood, D.; Browne, R.; Rodriguez, A. B.

    2010-12-01

    Located midway between Cape Fear and Cape Lookout, North Carolina, Onslow Beach is a 12 km-long barrier island, which historically had transgressive and stable profiles on the southern and northern ends, respectively. The northern half of the island has well-developed dunes in front of maritime forest. The southern half is low-lying and is characterized by washover fans infringing on salt marsh. By studying the underlying barrier lithology and structure, we will determine the evolution of the island at millennial time scales and in turn address whether the along-beach variations in barrier morphology and the historical shoreline-movement trends are related to the underlying geology. We collected 33 vibracores along 7 cross-shore transects spaced equally along Onslow Beach. Variations in topography were measured along these transects using an RTK-GPS. Cores collected from southern transects revealed multiple marsh-overwash sequences overlying estuarine deposits or a highly compacted unit typically composed of gray clay or brown medium to fine grained sand, possibly of Pleistocene age. The contact between this Pleistocene unit and the overlying estuarine deposits or thin peat layer represents the initial inundation of the area in response to Holocene sea-level rise. The elevation of this contact decreases towards the north along the island to a point where our coring methods could not penetrate deep enough to sample it (>4.0 m below the surface). In addition, marsh deposits sampled in the north below the island, which range from 30-120cm, were commonly found to be thicker than the marsh deposits sampled in the south, which range from 10-30 cm. These thick back-barrier units in the north preserve paleo overwash events as fining-upward sequences and likely accreted and were preserved due to the large accommodation space that the deep Pleistocene surface provided. The stratigraphy of the northern cores indicates a less stable Island in the past dominated by overwash

  5. Hindcasting potential hurricane impacts on rapidly changing barrier islands

    Science.gov (United States)

    Stockdon, H.F.; Thompson, D.M.; Sallenger, A.H., Jr.

    2007-01-01

    Hindcasts of the coastal impact of Hurricane Ivan on Santa Rosa Island, Florida, using a storm-impact scaling model that compares hurricane-induced water levels to local dune morphology, were found to have an accuracy of 68% in predicting the occurrence of one of four impact regimes: swash, collision, overwash, and inundation. Errors were overwhelming under-predictions of the regime where the observed response was more extreme than had been expected. This is related to the evolution of the profile during the storm. Mean pre-storm dune elevations decreased by 1.9 m over the 75-km long island as most of the dunes were completely eroded during the storm. Dramatic morphologic change during a hurricane makes barrier islands more vulnerable to overwash and inundation than will be predicted based on pre-storm dune parameters. Incorporation of the timing of rising water levels relative to storm-induced profile evolution is required to improve model accuracy.

  6. The calcified seaweed (maerl) deposits of the Falkland Islands

    OpenAIRE

    Stone, P; Merriman, R.J.; Kemp, S.J.

    2003-01-01

    Scattered across many foreshore areas around the Falkland Islands (Fig. 1) are fragments of white, limy material derived from carbonate-fixing, marine red algae. Locally, the limy detritus is sufficiently abundant to have built-up substantial beach deposits. In their report accompanying publication of the 1:250 000 scale geological maps of the islands, Aldiss and Edwards (1998) drew attention to the potential importance of these deposits as a source of agricultural lime, particularly in the a...

  7. Observations of barrier island length explained using an exploratory morphodynamic model

    NARCIS (Netherlands)

    Roos, P.C.; Schuttelaars, H.M.; Brouwer, R.L.

    2013-01-01

    Barrier coasts display a chain of islands, separated by tidal inlets that connect a back-barrier basin to a sea or ocean. Observations show that barrier island length generally decreases for increasing tidal range and increasing basin area. However, this has neither been reproduced in model studies

  8. Reconstruction of Holocene coastal depositional environments based on sedimentological and palaeontological analyses, Zakynthos Island, Western Greece Mediterranean Sea

    Science.gov (United States)

    Avramidis, Pavlos; Iliopoulos, George; Papadopoulou, Penelope; Nikolaou, Konstantinos; Kontopoulos, Nikolaos; Wijngaarden, Gert

    2014-05-01

    Zakynthos Island is one of the most seismically active regions in Europe and the Holocene coastal depositional environments were influenced both by tectonic activity and sea level rise. In the present study detailed sedimentological, palaeontological and 14C dating analyses were used in order to reconstruct the Holocene coastal depositional environments as well as the different rates of sedimentation, based on data from three cores up to 30 m deep. The results of the analyses indicate changes in depositional environments from marine to brackish lagoonal and lagoon / barrier systems with temporary intrusions of marine water via storms or tsunamigenic events. High sedimentation rates in coastal areas of Zakynthos Island correspond well to the most widespread Holocene warm and humid phases. The interpretation of the sedimentological environments reveals that Zakynthos Island before 8300 BP was constituted by two islands, where the present southern part of the island was separated from the northern one by a shallow and narrow sea channel.

  9. Piping plover habitat suitability on central Long Island, New York barrier islands

    OpenAIRE

    Elias-Gerken, Susan P.

    1994-01-01

    The breeding ecology of Piping Plovers (Charadrius me/odus) was examined on the central barrier islands of Long Island, N.Y. during the 1992 and 1993 breeding seasons. The estimated breeding populations were 79 pairs in 1992 and 82 pairs in 1993. Productivity was 1.08 chicks fledged per pair. The popu lation appeared stable, but below carrying capacity. Predation was the leading cause of nest loss (300/0), and crows (Corvus brachyrhynchos and/or C. ossifragus) accou nted for 71...

  10. Shoreline and beach volume change between 1967 and 2007 at Raine Island, Great Barrier Reef, Australia

    Science.gov (United States)

    Dawson, John L.; Smithers, Scott G.

    2010-06-01

    Raine Island is a vegetated coral cay located on the far northern outer Great Barrier Reef (GBR), recognised as a globally significant turtle rookery. Cay geomorphology, specifically the morphology of the beach and swale, dictate the availability of nesting sites and influence nesting success. Understanding short and long-term shoreline change is critical for managers charged with protecting the nesting habitat, particularly as climate change progresses. Historical topographic surveys, a simple numerical model and geographic information system (GIS) techniques were used to reconstruct a 40-year (1967-2007) shoreline history of Raine Island. Results show that significant shoreline change has occurred on 78% of the island's shoreline between 1967 and 2007; 34% experienced net retreat and 44% net progradation during the study interval. Shoreline retreat is mainly concentrated on the east-southeast section of the shoreline (average annual rate of - 0.3 ± 0.3 m/yr), while the shore on the western side of the island prograded at a similar rate (0.4 ± 0.2 m/yr). A seasonal signal was detected relating to oscillations in wind direction and intensity, with the southeast and west-southwest shorelines migrating an average of ˜ 17 m from season to season. The volume of sediment deposited on Raine Island between 1967 and 2007 increased by ˜ 68,000 m 3 net, but accretion rates varied significantly seasonally and from year to year. The largest volumetric changes have typically occurred over the last 23 years (1984-2007). Despite the recent concern that Raine Island is rapidly eroding, our data demonstrate net island growth (6% area, 4% volume) between 1967 and 2007. Perceptions of erosion probably reflect large morphological changes arising from seasonal, inter-annual and inter-decadal patterns of sediment redistribution rather than net loss from the island's sediment budget.

  11. Forest Hydrology, Soil Conservation and Green Barriers in Canary Islands

    Directory of Open Access Journals (Sweden)

    Juan Carlos SANTAMARTA-CEREZAL

    2012-11-01

    Full Text Available In volcanic islands, the rainfall regime and its torrential nature, together with the steep slopes and the soil types present are considered to be some of the main factors affecting forest hydrology and soil conservation. In such environments, rain regime is generally irregular and characterized by short and intense rainfalls, which could cause destructive flows at times, followed by long periods of rain absence. The volcanic nature of these islands have as a direct resultant steep slopes which influences the runoff volume and speed, as well as the amount of topsoil susceptible to be detached and transported downstream. The soil type also affects the susceptibility to erosion processes. Andisols are the most typical soil on volcanic islands. Their particularities derive their mineral constituents, called short-range-order products, which provide these soils with an increased structural stability, which in turn reduces their susceptibility to erosion. However, the land use changes and the environmental factors such as rain regime and steep slopes may be determinant factor in destabilizing these soils and ultimately a cause for soil erosion and runoffs, which become a threat to the population downstream. Green barriers have been traditionally used to prevent or reduce these processes, also to enhance the dew effect and the fog water collection, and as a firebreak which acts as a barrier to slow or stop the progress of a wildfire. Wooded species present and subsequently their performance have a major influence on their effectiveness. The use of this natural erosion and fire control methods on volcanic islands is discussed in this paper.

  12. Application of Bayesian Networks to hindcast barrier island morphodynamics

    Science.gov (United States)

    Wilson, Kathleen E.; Adams, Peter N.; Hapke, Cheryl J.; Lentz, Erika E.; Brenner, Owen T.

    2015-01-01

    Prediction of coastal vulnerability is of increasing concern to policy makers, coastal managers and other stakeholders. Coastal regions and barrier islands along the Atlantic and Gulf coasts are subject to frequent, large storms, whose waves and storm surge can dramatically alter beach morphology, threaten infrastructure, and impact local economies. Given that precise forecasts of regional hazards are challenging, because of the complex interactions between processes on many scales, a range of probable geomorphic change in response to storm conditions is often more helpful than deterministic predictions. Site-specific probabilistic models of coastal change are reliable because they are formulated with observations so that local factors, of potentially high influence, are inherent in the model. The development and use of predictive tools such as Bayesian Networks in response to future storms has the potential to better inform management decisions and hazard preparation in coastal communities. We present several Bayesian Networks designed to hindcast distinct morphologic changes attributable to the Nor'Ida storm of 2009, at Fire Island, New York. Model predictions are informed with historical system behavior, initial morphologic conditions, and a parameterized treatment of wave climate.

  13. Mapping risk for nest predation on a barrier island

    Science.gov (United States)

    Hackney, Amanda D.; Baldwin, Robert F.; Jodice, Patrick G.

    2013-01-01

    Barrier islands and coastal beach systems provide nesting habitat for marine and estuarine turtles. Densely settled coastal areas may subsidize nest predators. Our purpose was to inform conservation by providing a greater understanding of habitat-based risk factors for nest predation, for an estuarine turtle. We expected that habitat conditions at predated nests would differ from random locations at two spatial extents. We developed and validated an island-wide model for the distribution of predated Diamondback terrapin nests using locations of 198 predated nests collected during exhaustive searches at Fisherman Island National Wildlife Refuge, USA. We used aerial photographs to identify all areas of possible nesting habitat and searched each and surrounding environments for nests, collecting location and random-point microhabitat data. We built models for the probability of finding a predated nest using an equal number of random points and validated them with a reserve set (N = 67). Five variables in 9 a priori models were used and the best selected model (AIC weight 0.98) reflected positive associations with sand patches near marshes and roadways. Model validation had an average capture rate of predated nests of 84.14 % (26.17–97.38 %, Q1 77.53 %, median 88.07 %, Q3 95.08 %). Microhabitat selection results suggest that nests placed at the edges of sand patches adjacent to upland shrub/forest and marsh systems are vulnerable to predation. Forests and marshes provide cover and alternative resources for predators and roadways provide access; a suggestion is to focus nest protection efforts on the edges of dunes, near dense vegetation and roads.

  14. Atomic layer deposited aluminum oxide barrier coatings for packaging materials

    Energy Technology Data Exchange (ETDEWEB)

    Hirvikorpi, Terhi, E-mail: terhi.hirvikorpi@vtt.f [Oy Keskuslaboratorio - Centrallaboratorium Ab (KCL), P.O. Box 70, FI-02151 Espoo (Finland); Vaehae-Nissi, Mika, E-mail: mika.vaha-nissi@vtt.f [Oy Keskuslaboratorio - Centrallaboratorium Ab (KCL), P.O. Box 70, FI-02151 Espoo (Finland); Mustonen, Tuomas, E-mail: tuomas.mustonen@vtt.f [Oy Keskuslaboratorio - Centrallaboratorium Ab (KCL), P.O. Box 70, FI-02151 Espoo (Finland); Iiskola, Eero, E-mail: eero.iiskola@kcl.f [Oy Keskuslaboratorio - Centrallaboratorium Ab (KCL), P.O. Box 70, FI-02151 Espoo (Finland); Karppinen, Maarit, E-mail: maarit.karppinen@tkk.f [Laboratory of Inorganic Chemistry, Department of Chemistry, Helsinki University of Technology, P.O. Box 6100, FI-02015 TKK (Finland)

    2010-03-01

    Thin aluminum oxide coatings have been deposited at a low temperature of 80 {sup o}C on various uncoated papers, polymer-coated papers and boards and plain polymer films using the atomic layer deposition (ALD) technique. The work demonstrates that such ALD-grown Al{sub 2}O{sub 3} coatings efficiently enhance the gas-diffusion barrier performance of the studied porous and non-porous materials towards oxygen, water vapor and aromas.

  15. Modeling the Response of Human Altered Natural Barrier Island Dynamics Along Assateague Island National Seashore to Climate Change

    Science.gov (United States)

    Carroll, A.; McNamara, D.; Schupp, C.

    2009-12-01

    Assateague Island National Seashore comprises a long barrier island located off the coasts of Maryland and Virginia. Geological evidence suggests that over recent centuries Assateague Island has steadily transgressed up the continental shelf in response to rising sea level. More recently, the natural barrier island dynamics governing Assateague’s evolution have been altered by human activity in three ways: the construction of a jetty and the subsequent interruption of alongshore sediment transport on the north end of Assateague and both the ongoing and abandoned maintenance of a continuous dune system along portions of Assateague with the concomitant modification to overwash dynamics. It is unclear how these varied human alterations to the natural barrier island dynamics will influence the response of Assateague to climate change induced shifts in forcing such as increased rates of sea level rise and changing storm patterns. We use LIDAR detected morphological data of Assateague Island as initial conditions in an alongshore extended model for barrier island dynamics including beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms to explore the response of the various human altered segments of Assateague Island to forcing changes. Traditional models exploring barrier island evolution contain only cross-shore dynamics therefore lacking important alongshore-spatial dynamics in aeolian and surf zone sediment transport. Results show that including alongshore dynamics alter the steady state of Assateague relative to simulations that only include cross-shore dynamics. Results will also be presented exploring the potential for regime shifts in steady state behavior under various scenarios for the rate of sea level rise and storm climate and varying management strategies.

  16. Shoreline erosion rates along barrier islands of the north central gulf of Mexico

    Science.gov (United States)

    Shabica, Stephen V.; Dolan, Robert; May, Suzette; May, Paul

    1983-09-01

    Rates of shoreline change and overwash penetration distances were calculated for barrier islands along the Louisiana, Mississippi, and Alabama coasts with the orthogonal grid mapping system (OGMS). Average rates of shoreline change are exceptionally high in Louisiana, being of the order -4.7 to -7.4 m yr-1. Mississippi and Alabama recession rates are lower and range from -2.0 to -3.1 m yr-1 over the period of record. Erosion rates along the shorelines of these islands have remained relatively constant over the period of study with five exceptions in coastal Louisiana and the Chandeleur-Breton Islands Arc, and two exceptions along the Mississippi-Alabama barrier islands where they have accelerated. Mean overwash penetration is greatest along Dauphin Island, Alabama, and Cat Island, Mississippi: 207.6 and 197.9 m, respectively. The Chandeleur-Brenton Islands Arc range from 88.1 m at the central barrier to 180.4 along the flanks. The Mississippi islands range from 105.2 m on Ship Island to 200.5 m along central Horn Island. Mean overwash penetration along the Louisiana barriers is highly variable: 46.3 to 211.4 m.

  17. Roll-to-roll vacuum deposition of barrier coatings

    CERN Document Server

    Bishop, Charles A

    2015-01-01

    It is intended that the book will be a practical guide to provide any reader with the basic information to help them understand what is necessary in order to produce a good barrier coated web or to improve the quality of any existing barrier product. After providing an introduction, where the terminology is outlined and some of the science is given (keeping the mathematics to a minimum), including barrier testing methods, the vacuum deposition process will be described. In theory a thin layer of metal or glass-like material should be enough to convert any polymer film into a perfect barrier material. The reality is that all barrier coatings have their performance limited by the defects in the coating. This book looks at the whole process from the source materials through to the post deposition handling of the coated material. This holistic view of the vacuum coating process provides a description of the common sources of defects and includes the possible methods of limiting the defects. This enables readers...

  18. EAARL Coastal Topography--Eastern Louisiana Barrier Islands, Post-Hurricane Gustav, 2008: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation model (DEM) of a portion of the eastern Louisiana barrier islands, post-Hurricane Gustav (September 2008 hurricane), was produced from remotely...

  19. EAARL Coastal Topography--Mississippi and Alabama Barrier Islands, Post-Hurricane Gustav, 2008

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation model (DEM) of a portion of the Mississippi and Alabama barrier islands, post-Hurricane Gustav (September 2008 hurricane), was produced from...

  20. Summer bird use of a barrier island near Prudhoe Bay, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The number and distribution of birds near a barrier island west of Prudhoe Bay, Alaska, were recorded during the summer of 1972. Eiders fed and rested in the open...

  1. Controls on coastal dune morphology, shoreline erosion and barrier island response to extreme storms

    Science.gov (United States)

    Houser, C.; Hapke, C.; Hamilton, S.

    2008-01-01

    The response of a barrier island to an extreme storm depends in part on the surge elevation relative to the height and extent of the foredunes which can exhibit considerable variability alongshore. While it is recognized that alongshore variations in dune height and width direct barrier island response to storm surge, the underlying causes of the alongshore variation remain poorly understood. This study examines the alongshore variation in dune morphology along a 11??km stretch of Santa Rosa Island in northwest Florida and relates the variation in morphology to the response of the island during Hurricane Ivan and historic and storm-related rates of shoreline erosion. The morphology of the foredune and backbarrier dunes was characterized before and after Hurricane Ivan using Empirical Orthogonal Function (EOF) analysis and related through Canonical Correlation Analysis (CCA). The height and extent of the foredune, and the presence and relative location of the backbarrier dunes, varied alongshore at discrete length scales (of ~ 750, 1450 and 4550??m) that are statistically significant at the 95% confidence level. Cospectral analysis suggests that the variation in dune morphology is correlated with transverse ridges on the inner-shelf, the backbarrier cuspate headlands, and the historical and storm-related trends in shoreline change. Sections of the coast with little to no dune development before Hurricane Ivan were observed in the narrowest portions of the island (between headlands), west of the transverse ridges. Overwash penetration tended to be larger in these areas and island breaching was common, leaving the surface close to the watertable and covered by a lag of shell and gravel. In contrast, large foredunes and the backbarrier dunes were observed at the widest sections of the island (the cuspate headlands) and at crest of the transverse ridges. Due to the large dunes and the presence of the backbarrier dunes, these areas experienced less overwash penetration

  2. Deposition of moisture barrier films by catalytic CVD using hexamethyldisilazane

    Science.gov (United States)

    Ohdaira, Keisuke; Matsumura, Hideki

    2014-01-01

    Hexamethyldisilazane (HMDS) is utilized to deposit moisture barrier films by catalytic chemical vapor deposition (Cat-CVD). An increase in the thickness of silicon oxynitride (SiOxNy) films leads to a better water-vapor transmission rate (WVTR), indicating that Cat-CVD SiOxNy films deposited using HMDS do not severely suffer from cracking. A WVTR on the order of 10-3 g m-2 day-1 can be realized by a Cat-CVD SiOxNy film formed using HMDS on a poly(ethylene terephthalate) (PET) substrate without any stacking structures at a substrate temperature of as low as 60 °C. X-ray reflectivity (XRR) measurement reveals that a film density of >2.0 g/cm3 is necessary for SiOxNy films to demonstrate an effective moisture barrier ability. The use of HMDS will give us safer production of moisture barrier films because of its non-explosive and non-toxic nature.

  3. Oxygen Barrier Coating Deposited by Novel Plasma-enhanced Chemical Vapor Deposition

    DEFF Research Database (Denmark)

    Jiang, Juan; Benter, M.; Taboryski, Rafael Jozef;

    2010-01-01

    We report the use of a novel plasma-enhanced chemical vapor deposition chamber with coaxial electrode geometry for the SiOx deposition. This novel plasma setup exploits the diffusion of electrons through the inner most electrode to the interior samples space as the major energy source. This confi...... increased the barrier property of the modified low-density polyethylene, polyethylene terephthalate, and polylactide by 96.48%, 99.69%, and 99.25%, respectively....

  4. Geological and production characteristics of strandplain/barrier island reservoirs in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Cole, E.L.; Fowler, M.; Jackson, S.; Madden, M.P.; Reeves, T.K.; Salamy, S.P.; Young, M.A.

    1994-12-01

    The Department of Energy`s (DOE`s) primary mission in the oil research program is to maximize the economically and environmentally sound recovery of oil from domestic reservoirs and to preserve access to this resource. The Oil Recovery Field Demonstration Program supports DOE`s mission through cost-shared demonstrations of improved Oil Recovery (IOR) processes and reservoir characterization methods. In the past 3 years, the DOE has issued Program Opportunity Notices (PONs) seeking cost-shared proposals for the three highest priority, geologically defined reservoir classes. The classes have been prioritized based on resource size and risk of abandonment. This document defines the geologic, reservoir, and production characteristics of the fourth reservoir class, strandplain/barrier islands. Knowledge of the geological factors and processes that control formation and preservation of reservoir deposits, external and internal reservoir heterogeneities, reservoir characterization methodology, and IOR process application can be used to increase production of the remaining oil-in-place (IOR) in Class 4 reservoirs. Knowledge of heterogeneities that inhibit or block fluid flow is particularly critical. Using the TORIS database of 330 of the largest strandplain/barrier island reservoirs and its predictive and economic models, the recovery potential which could result from future application of IOR technologies to Class 4 reservoirs was estimated to be between 1.0 and 4.3 billion barrels, depending on oil price and the level of technology advancement. The analysis indicated that this potential could be realized through (1) infill drilling alone and in combination with polymer flooding and profile modification, (2) chemical flooding (sufactant), and (3) thermal processes. Most of this future potential is in Texas, Oklahoma, and the Rocky Mountain region. Approximately two-thirds of the potentially recoverable resource is at risk of abandonment by the year 2000.

  5. Barrier island response to late Holocene climate events, North Carolina, USA

    Science.gov (United States)

    Mallinson, D.J.; Smith, C.W.; Mahan, S.; Culver, S.J.; McDowell, K.

    2011-01-01

    The Outer Banks barrier islands of North Carolina, USA, contain a geologic record of inlet activity that extends from ca. 2200. cal. yr BP to the present, and can be used as a proxy for storm activity. Optically stimulated luminescence (OSL) dating (26 samples) of inlet-fill and flood tide delta deposits, recognized in cores and geophysical data, provides the basis for understanding the chronology of storm impacts and comparison to other paleoclimate proxy data. OSL ages of historical inlet fill compare favorably to historical documentation of inlet activity, providing confidence in the technique. Comparison suggests that the Medieval Warm Period (MWP) and Little Ice Age (LIA) were both characterized by elevated storm conditions as indicated by much greater inlet activity relative to today. Given present understanding of atmospheric circulation patterns and sea-surface temperatures during the MWP and LIA, we suggest that increased inlet activity during the MWP responded to intensified hurricane impacts, while elevated inlet activity during the LIA was in response to increased nor'easter activity. A general decrease in storminess at mid-latitudes in the North Atlantic over the last 300. yr has allowed the system to evolve into a more continuous barrier with few inlets. ?? 2011 University of Washington.

  6. EAARL Coastal Topography - Northeast Barrier Islands 2007: First Surface

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Sallenger, A.H.; Wright, C. Wayne; Yates, Xan; Bonisteel, Jamie M.

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived first surface (FS) topography were produced collaboratively by the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of the northeast coastal barrier islands in New York and New Jersey, acquired April 29-30 and May 15-16, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed using the Airborne Lidar Processing System (ALPS), a

  7. EAARL Coastal Topography - Northeast Barrier Islands 2007: Bare Earth

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Sallenger, A.H.; Wright, C. Wayne; Yates, Xan; Bonisteel, Jamie M.

    2008-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived bare earth (BE) topography were produced collaboratively by the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of the northeast coastal barrier islands in New York and New Jersey, acquired April 29-30 and May 15-16, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed using the Airborne Lidar Processing System (ALPS), a custom

  8. Stratigraphy, evolution, and controls of a Holocene transgressive-regressive barrier island under changing sea-level

    DEFF Research Database (Denmark)

    Fruergaard, Mikkel; Møller, Ingelise; Johannessen, Peter;

    2015-01-01

    . The results show that the barrier island experienced multiple phases of transgressions and regressions during the mid- and late Holocene and that these changes were driven primarily by changes in rates of sea-level rise, sediment supply and the impact of storms. Due to the postglacial sea-level rise......, the seaward part of the study area was transgressed by the retreating mainland shoreline, forming a back-barrier basin. At the time of the initial transgression, sea level was rising by more than 4.0 mm yr−1. As sea-level rise decreased to less than 2 mm yr−1 the back-barrier basin rapidly started to......) location, the open-ocean shoreline prograded about 3 km seaward at a rate of > 3 m yr−1 through the deposition of a 7-m-thick sandy beach and shoreface succession. The progradation occurred despite a sea-level rise of about 1.8 mm yr−1. After the regressive period the barrier island once again became...

  9. Modeling barrier island response to sea-level rise in the outer Banks, North Carolina

    Science.gov (United States)

    Moore, Laura J.; List, Jeffrey H.; Williams, S. Jeffress; Stolper, David

    2007-01-01

    An 8500-year Holocene simulation developed in GEOMBEST provides a possible scenario to explain the evolution of barrier coast between Rodanthe and Cape Hatteras, NC. Sensitivity analyses suggest that in the Outer Banks, the rate of sea-level rise is the most important factor in determining how barrier islands evolve. The Holocene simulation provides a basis for future simulations, which suggest that if sea level rises up to 0.88 m by AD 2100, as predicted by the highest estimates of the Intergovernmental Panel on Climate Change, the barrier in the study area may migrate on the order of 2.5 times more rapidly than at present. If sea level rises beyond IPCC predictions to reach 1.4–1.9 m above modern sea level by AD 2100, model results suggest that barrier islands in the Outer Banks may become vulnerable to threshold collapse, disintegrating during storm events, by the end of the next century. Consistent with sensitivity analyses, additional simulations indicate that anthropogenic activities, such as increasing the rate of sediment supply through beach nourishment, will only slightly affect barrier island migration rates and barrier island vulnerability to collapse.

  10. How a barrier island may react on a sea-level rise: The Holocene to Recent Rømø barrier island, Danish Wadden Sea

    DEFF Research Database (Denmark)

    Johannessen, Peter N.; Nielsen, Lars H.; Møller, Ingelise;

    of c. 15 m and a resolution of c. 20–30 cm (Nielsen et al., 2009), and dating of 70 core samples using optically stimulated luminescence (OSL). The area has experienced a relative sea-level rise of c. 15 m during the last c. 8000 years. The Recent tidal amplitude reaches c. 1.8 m. During strong wind...... and related shoreface sand and lagoonal sediments are up to 20 m thick and overlie Weichselian fluvial sand. The first 5000 years the barrier island aggraded and the last 3000 years it prograded despite the relative rising sea level rise of c. 15 m during the last c. 8000 years. This shows, that if...... there is a surplus of sand in a tidal area, barrier islands may aggrade even if there is a rise in sea level. If the rate of sea level rise decreases then the barrier island may prograded. With this unique dataset with extremely large amounts of OSL datings from core sediments it has been possible to...

  11. The importance of large benthic foraminifera to reef island sediment budget and dynamics at Raine Island, northern Great Barrier Reef

    Science.gov (United States)

    Dawson, John L.; Smithers, Scott G.; Hua, Quan

    2014-10-01

    Low-lying reef islands are among the most vulnerable environments on earth to anthropogenic-induced climate change and sea-level rise over the next century because they are low, composed of unconsolidated sediment that is able to be mobilised by waves and currents, and depend on sediments supplied by reef organisms that are particularly sensitive to environmental changes (e.g. ocean temperatures and chemistry). Therefore, the spatial and temporal links between active carbonate production and island formation and dynamics are fundamental to predicting future island resilience, yet remain poorly quantified. In this paper we present results of a detailed geomorphological and sedimentological study of a reef and sand cay on the northern Great Barrier Reef. We provide an empirical investigation of the temporal linkages between sediment production and reef island development using a large collection of single grain AMS 14C dates. Large benthic foraminifera (LBF) are the single most important contributor to contemporary island sand mass (47%; ranging from 36% to 63%) at Raine Island, reflecting rapid rates of sediment production and delivery. Standing stock data reveal extremely high production rates on the reef (1.8 kg m- 2 yr- 1), while AMS 14C dates of single LBF tests indicate rapid rates of sediment transferral across the reef. We also demonstrate that age is statistically related to preservation and taphonomic grade (severely abraded tests > moderately abraded tests > pristine tests). We construct a contemporary reef and island sediment budget model for Raine Island that shows that LBF (Baculogypsina, Marginopora and Amphistegina) contribute 55% of the sediment produced on the reef annually, of which a large proportion (54%) contribute to the net annual accretion of the island. The tight temporal coupling between LBF growth and island sediment supply combined with the sensitivity of LBF to bleaching and ocean acidification suggests that islands dominated by LBF are

  12. Fallout Deposition in the Marshall Islands from Bikini and Enewetak Nuclear Weapons Tests

    OpenAIRE

    Beck, Harold L.; Bouville, André; Moroz, Brian E.; Simon, Steven L.

    2010-01-01

    Deposition densities (Bq m-2) of all important dose-contributing radionuclides occurring in nuclear weapons testing fallout from tests conducted at Bikini and Enewetak Atolls (1946-1958) have been estimated on a test-specific basis for all the 31 atolls and separate reef islands of the Marshall Islands. A complete review of various historical and contemporary data, as well as meteorological analysis, was used to make judgments regarding which tests deposited fallout in the Marshall Islands an...

  13. Gas permeation barriers deposited by atmospheric pressure plasma enhanced atomic layer deposition

    International Nuclear Information System (INIS)

    This paper reports on aluminum oxide (Al2O3) thin film gas permeation barriers fabricated by atmospheric pressure atomic layer deposition (APPALD) using trimethylaluminum and an Ar/O2 plasma at moderate temperatures of 80 °C in a flow reactor. The authors demonstrate the ALD growth characteristics of Al2O3 films on silicon and indium tin oxide coated polyethylene terephthalate. The properties of the APPALD-grown layers (refractive index, density, etc.) are compared to that deposited by conventional thermal ALD at low pressures. The films films deposited at atmospheric pressure show water vapor transmission rates as low as 5 × 10−5 gm−2d−1

  14. Effects of sea-level rise on barrier island groundwater system dynamics: ecohydrological implications

    Science.gov (United States)

    Masterson, John P.; Fienen, Michael N.; Thieler, E. Robert; Gesch, Dean B.; Gutierrez, Benjamin T.; Plant, Nathaniel G.

    2014-01-01

    We used a numerical model to investigate how a barrier island groundwater system responds to increases of up to 60 cm in sea level. We found that a sea-level rise of 20 cm leads to substantial changes in the depth of the water table and the extent and depth of saltwater intrusion, which are key determinants in the establishment, distribution and succession of vegetation assemblages and habitat suitability in barrier islands ecosystems. In our simulations, increases in water-table height in areas with a shallow depth to water (or thin vadose zone) resulted in extensive groundwater inundation of land surface and a thinning of the underlying freshwater lens. We demonstrated the interdependence of the groundwater response to island morphology by evaluating changes at three sites. This interdependence can have a profound effect on ecosystem composition in these fragile coastal landscapes under long-term changing climatic conditions.

  15. Coupled barrier island-resort model: 2. Tests and predictions along Ocean City and Assateague Island National Seashore, Maryland

    Science.gov (United States)

    McNamara, D. E.; Werner, B. T.

    2008-03-01

    The fate of coastlines and their human settlements under the effects of global climate change will depend critically on the nonlinear dynamics of and feedbacks between shoreline processes and human agency. This hypothesis is explored on the barrier island coastline of Ocean City and Assateague Island National Seashore, Maryland, using a model-coupling natural coastal processes, including erosion, accretion, island overwash, alongshore sediment transport, dune growth and migration, inlet migration and ebb tidal delta growth to economics of tourist resort development through storm damage and beach and dune replenishment. Initiating the model in 1845, the RMS difference between model and measurements of the shoreline position in 2001 is 84.97 m compared to a net onshore migration of 472.2 m and the RMS difference between modeled and measured hotel room density in 2001 is 2950 rooms km-1 compared to a net gain of 28,824 rooms km-1. Simulations to year 3400 for a rate of sea level rise of 3.5 mm a-1 show a steady state barrier island position 158 m further offshore and 0.54 m lower in elevation compared to its natural counterpart. Changing the rate of sea level rise to 10.5 mm a-1 increases these differences to 288 m and 0.76 m. Changing storminess by increasing the standard deviation of storm size 50% diminishes coupling between resorts and barriers, bringing the natural and coupled attractors into near coincidence. These results suggest that predicted increases in the rate of sea level rise will lead to enhanced vulnerability for Ocean City.

  16. Upper Pleistocene deposits of the Comprida Island (São Paulo State dated by thermoluminescence method

    Directory of Open Access Journals (Sweden)

    SUGUIO KENITIRO

    2003-01-01

    Full Text Available The Cananéia (Upper Pleistocene and the Comprida Island (Holocene formations, outcropping in the Comprida island (SP have been mapped using geomorphological and lithological criteria. Only one sample of the Cananéia Formation, collected in the homonymous island in front of the Comprida Island, was beyond the limit of the standard radiocarbon method. But since the publication of the geological map of the area in 1978, there has been some doubt on the real occurrence of Pleistocene deposits in southern extremity of Comprida Island. This paper deals with the results of thermoluminescence (TL ages of eight samples from Comprida Island, which corroborate the Pleistocene age assumed during mapping surveys of these deposits. On the other hand, possible interpretations of the obtained ages, in relation to their depositional environments and related northern hemisphere Quaternary glaciations, are presented.

  17. An automated approach for extracting Barrier Island morphology from digital elevation models

    Science.gov (United States)

    Wernette, Phillipe; Houser, Chris; Bishop, Michael P.

    2016-06-01

    The response and recovery of a barrier island to extreme storms depends on the elevation of the dune base and crest, both of which can vary considerably alongshore and through time. Quantifying the response to and recovery from storms requires that we can first identify and differentiate the dune(s) from the beach and back-barrier, which in turn depends on accurate identification and delineation of the dune toe, crest and heel. The purpose of this paper is to introduce a multi-scale automated approach for extracting beach, dune (dune toe, dune crest and dune heel), and barrier island morphology. The automated approach introduced here extracts the shoreline and back-barrier shoreline based on elevation thresholds, and extracts the dune toe, dune crest and dune heel based on the average relative relief (RR) across multiple spatial scales of analysis. The multi-scale automated RR approach to extracting dune toe, dune crest, and dune heel based upon relative relief is more objective than traditional approaches because every pixel is analyzed across multiple computational scales and the identification of features is based on the calculated RR values. The RR approach out-performed contemporary approaches and represents a fast objective means to define important beach and dune features for predicting barrier island response to storms. The RR method also does not require that the dune toe, crest, or heel are spatially continuous, which is important because dune morphology is likely naturally variable alongshore.

  18. Louisiana Barrier Island Comprehensive Monitoring (BICM) Program Summary Report: Data and Analyses 2006 through 2010

    Science.gov (United States)

    Kindinger, Jack G.; Buster, Noreen A.; Flocks, James G.; Bernier, Julie C.; Kulp, Mark A.

    2013-01-01

    The Barrier Island Comprehensive Monitoring (BICM) program was implemented under the Louisiana Coastal Area Science and Technology (LCA S&T) office as a component of the System Wide Assessment and Monitoring (SWAMP) program. The BICM project was developed by the State of Louisiana (Coastal Protection Restoration Authority [CPRA], formerly Department of Natural Resources [DNR]) to complement other Louisiana coastal monitoring programs such as the Coastwide Reference Monitoring System-Wetlands (CRMS-Wetlands) and was a collaborative research effort by CPRA, University of New Orleans (UNO), and the U.S. Geological Survey (USGS). The goal of the BICM program was to provide long-term data on the barrier islands of Louisiana that could be used to plan, design, evaluate, and maintain current and future barrier-island restoration projects. The BICM program used both historical and newly acquired (2006 to 2010) data to assess and monitor changes in the aerial and subaqueous extent of islands, habitat types, sediment texture and geotechnical properties, environmental processes, and vegetation composition. BICM datasets included aerial still and video photography (multiple time series) for shoreline positions, habitat mapping, and land loss; light detection and ranging (lidar) surveys for topographic elevations; single-beam and swath bathymetry; and sediment grab samples. Products produced using BICM data and analyses included (but were not limited to) storm-impact assessments, rate of shoreline and bathymetric change, shoreline-erosion and accretion maps, high-resolution elevation maps, coastal-shoreline and barrier-island habitat-classification maps, and coastal surficial-sediment characterization maps. Discussions in this report summarize the extensive data-collection efforts and present brief interpretive analyses for four coastal Louisiana geographic regions. In addition, several coastal-wide and topical themes were selected that integrate the data and analyses within a

  19. Degradation of Thermal Barrier Coatings from Deposits and Its Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Nitin Padture

    2011-12-31

    Ceramic thermal barrier coatings (TBCs) used in gas-turbine engines afford higher operating temperatures, resulting in enhanced efficiencies and performance. However, in the case of syngas-fired engines, fly ash particulate impurities that may be present in syngas can melt on the hotter TBC surfaces and form glassy deposits. These deposits can penetrate the TBCs leading to their failure. In experiments using lignite fly ash to simulate these conditions we show that conventional TBCs of composition 93wt% ZrO{sub 2} + 7wt% Y{sub 2}O{sub 3} (7YSZ) fabricated using the air plasma spray (APS) process are completely destroyed by the molten fly ash. The molten fly ash is found to penetrate the full thickness of the TBC. The mechanisms by which this occurs appear to be similar to those observed in degradation of 7YSZ TBCs by molten calcium-magnesium-aluminosilicate (CMAS) sand and by molten volcanic ash in aircraft engines. In contrast, APS TBCs of Gd{sub 2Zr{sub 2}O{sub 7} composition are highly resistant to attack by molten lignite fly ash under identical conditions, where the molten ash penetrates ~25% of TBC thickness. This damage mitigation appears to be due to the formation of an impervious, stable crystalline layer at the fly ash/Gd{sub 2}Zr{sub 2}O{sub 7} TBC interface arresting the penetrating moltenfly- ash front. Additionally, these TBCs were tested using a rig with thermal gradient and simultaneous accumulation of ash. Modeling using an established mechanics model has been performed to illustrate the modes of delamination, as well as further opportunities to optimize coating microstructure. Transfer of the technology was developed in this program to all interested parties.

  20. Scale dependent behavior the foredune: Implications for barrier island response to storms and sea level rise

    Science.gov (United States)

    Houser, C.; Wernette, P. A.; Weymer, B. A.

    2015-12-01

    The impact of elevated storm surge on a barrier island tends to be considered from a single cross-shore dimension and dependent only on the relative elevations of the storm surge and dune. However, the foredune line is rarely uniform and can exhibit considerable variation in height and width alongshore at a range of length scales ranging from tens of meters to several kilometers. LiDAR data from Santa Rosa Island in northwest Florida, Padre Island, Texas and Assateague Island, Maryland are used to explore how the dune morphology varies alongshore and how this variability is altered by storms and post-storm recovery. While the alongshore variation in dune height can be approximated by a power law, there are scale-dependent variations in the dune that exhibit different responses to storm erosion and post-storm recovery. This suggests that the alongshore variation in dune morphology reflects the history of storm impact and recovery, and that changes in the variance magnitude through time may provide insight into whether the island will be resilient as it transgresses with rising sea level. The difference in variance magnitude at large spatial scales is associated with the framework geology unique to each island and a dominant control on island response to sea level rise.

  1. Effects of Super Strom Sandy on Depositional Environments Offshore Long Island, New York

    Science.gov (United States)

    Hosseini, P.; McHugh, C. M.; Christensen, B. A.; Dutton, J.; Brownawell, B.; Gurung, D.

    2013-12-01

    Hurricane Sandy's landfall affected the coastlines over a broad swath of mid-Atlantic including New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. The effects included breaching, overwash and erosion of barrier islands, some of which are heavily populated and sustained extensive damage. The peak storm-tide elevation produced by Hurricane Sandy measured by USGS stations in Jamaica Bay was about 3.5 m, 1.4 m more than the historical peak-water level elevations in the same area. As part of a National Science Foundation RAPID response we sampled the sediment in West Bay, Middle Bay, East Bay, Jones Inlet and Reynolds Channel of Long Island, New York from the R/V Pritchard. The sediment sampling took place 4 months after the storm and prior to any similar large storms. The sampling strategy was designed to characterize the post-storm sedimentation in distinct depositional environments. In this survey 156 grab samples were recovered from areas, many of which had been sampled prior to the storm. The samples were analyzed for grain size variability, short-lived radioisotopes and x-ray fluorescence elemental analyses. Google Earth images from before and after the storm reveal moderate to severe erosion and overwash of the dunes in Jones inlet, and Middle and East Bays. The Long Beach barrier island tidal marshes were submerged for several days post Sandy and underwent severe erosion. The storm surge brought from offshore a layer of coarse sand that was deposited over mussel beds. Most of the mussels were dead indicative of the strength of the waves. Be-7 concentrations allowed tracking the path of the storm from the bays and inlets, to the offshore. Some of the highest Be-7 concentrations ever detected in the local estuaries: 5,329, 4,955 and 4,553 pCi/kg were measured in West Bay and Middle Bay Channels. Additionally, unusually high Be-7 concentrations of 2,130 pCi/kg were recorded ~5.24 km offshore from Long Beach barrier island four months after the

  2. Predictions of barrier island berm evolution in a time-varying storm climatology

    Science.gov (United States)

    Plant, Nathaniel G.; Flocks, James; Stockdon, Hilary F.; Long, Joseph W.; Guy, Kristy K.; Thompson, David M.; Cormier, Jamie M.; Smith, Christopher G.; Miselis, Jennifer L.; Dalyander, P. Soupy

    2014-01-01

    Low-lying barrier islands are ubiquitous features of the world's coastlines, and the processes responsible for their formation, maintenance, and destruction are related to the evolution of smaller, superimposed features including sand dunes, beach berms, and sandbars. The barrier island and its superimposed features interact with oceanographic forces (e.g., overwash) and exchange sediment with each other and other parts of the barrier island system. These interactions are modulated by changes in storminess. An opportunity to study these interactions resulted from the placement and subsequent evolution of a 2 m high sand berm constructed along the northern Chandeleur Islands, LA. We show that observed berm length evolution is well predicted by a model that was fit to the observations by estimating two parameters describing the rate of berm length change. The model evaluates the probability and duration of berm overwash to predict episodic berm erosion. A constant berm length change rate is also predicted that persists even when there is no overwash. The analysis is extended to a 16 year time series that includes both intraannual and interannual variability of overwash events. This analysis predicts that as many as 10 or as few as 1 day of overwash conditions would be expected each year. And an increase in berm elevation from 2 m to 3.5 m above mean sea level would reduce the expected frequency of overwash events from 4 to just 0.5 event-days per year. This approach can be applied to understanding barrier island and berm evolution at other locations using past and future storm climatologies.

  3. Fabrication of metallic single electron transistors featuring plasma enhanced atomic layer deposition of tunnel barriers

    Science.gov (United States)

    Karbasian, Golnaz

    The continuing increase of the device density in integrated circuits (ICs) gives rise to the high level of power that is dissipated per unit area and consequently a high temperature in the circuits. Since temperature affects the performance and reliability of the circuits, minimization of the energy consumption in logic devices is now the center of attention. According to the International Technology Roadmaps for Semiconductors (ITRS), single electron transistors (SETs) hold the promise of achieving the lowest power of any known logic device, as low as 1x10-18 J per switching event. Moreover, SETs are the most sensitive electrometers to date, and are capable of detecting a fraction of an electron charge. Despite their low power consumption and high sensitivity for charge detection, room temperature operation of these devices is quite challenging mainly due to lithographical constraints in fabricating structures with the required dimensions of less than 10 nm. Silicon based SETs have been reported to operate at room temperature. However, they all suffer from significant variation in batch-to-batch performance, low fabrication yield, and temperature-dependent tunnel barrier height. In this project, we explored the fabrication of SETs featuring metal-insulator-metal (MIM) tunnel junctions. While Si-based SETs suffer from undesirable effect of dopants that result in irregularities in the device behavior, in metal-based SETs the device components (tunnel barrier, island, and the leads) are well-defined. Therefore, metal SETs are potentially more predictable in behavior, making them easier to incorporate into circuits, and easier to check against theoretical models. Here, the proposed fabrication method takes advantage of unique properties of chemical mechanical polishing (CMP) and plasma enhanced atomic layer deposition (PEALD). Chemical mechanical polishing provides a path for tuning the dimensions of the tunnel junctions, surpassing the limits imposed by electron beam

  4. Architecture of an Upper Jurassic barrier island sandstone reservoir, Danish Central Graben:

    DEFF Research Database (Denmark)

    Johannessen, Peter N.; Nielsen, Lars H.; Nielsen, Lars;

    2010-01-01

    seismic resolution is inadequate for architectural analysis. Description of the reservoir sandstone bodies is thus based on sedimentological interpretation and correlation of seven wells, of which five were cored. Palaeotopography played a major role in the position and preservation of the thick reservoir...... last c. 8000 years and is up to 20 m thick. To unravel the internal 3D facies architecture of the island, an extensive ground penetrating radar (GPR) survey of 35 km line length and seven cores, c. 25 m long, was obtained. Although the barrier island experienced a rapid relative sea-level rise...

  5. Restoration of overwash processes creates piping plover (Charadrius melodus) habitat on a barrier island (Assateague Island, Maryland)

    Science.gov (United States)

    Schupp, Courtney A.; Winn, Neil T.; Pearl, Tami L.; Kumer, John P.; Carruthers, Tim J. B.; Zimmerman, Carl S.

    2013-01-01

    On Assateague Island, an undeveloped barrier island along Maryland and Virginia, a foredune was constructed to protect the island from the erosion and breaching threat caused by permanent jetties built to maintain Ocean City Inlet. Scientists and engineers integrated expertise in vegetation, wildlife, geomorphology, and coastal engineering in order to design a habitat restoration project that would be evaluated in terms of coastal processes rather than static features. Development of specific restoration targets, thresholds for intervention, and criteria to evaluate long-term project success were based on biological and geomorphological data and coastal engineering models. A detailed long-term monitoring plan was established to measure project sustainability. The foredune unexpectedly acted as near-total barrier to both overwash and wind, and the dynamic ecosystem underwent undesirable habitat changes including conversion of early-succession beach habitat to herbaceous and shrub communities, diminishing availability of foraging habitat and thereby reducing productivity of the Federally-listed Threatened Charadrius melodus (piping plover). To address these impacts, multiple notches were cut through the constructed foredune. The metric for initial geomorphological success-restoration of at least one overwash event per year across the constructed foredune, if occurring elsewhere on the island-was reached. New overwash fans increased island stability by increasing interior island elevation. At every notch, areas of sparse vegetation increased and the new foraging habitat was utilized by breeding pairs during the 2010 breeding season. However, the metric for long-term biological success-an increase to 37% sparsely vegetated habitat on the North End and an increase in piping plover productivity to 1.25 chicks fledged per breeding pair-has not yet been met. By 2010 there was an overall productivity of 1.2 chicks fledged per breeding pair and a 1.7% decrease in sparsely

  6. Island Formation through Bar Deposition and Channel Cutoff in the Bedrock Controlled South River, Virginia

    Science.gov (United States)

    Jurk, D.; Pizzuto, J. E.

    2010-12-01

    Islands in braided and meandering alluvial channels form by bar accretion and channel cutoff, however, island formation in bedrock-controlled channels is poorly understood. The South River is a single-thread, sinuous, gravel-bed, bedrock river. It is neither meandering nor braided but aerial photographs show the development of gravel bars and the formation of islands that have formed through channel cutoff. This study deciphers processes that lead to both types of island formation and their role in the channel morphology of the South River. The South River was analyzed using aerial photographs and work in the field provided additional data that were used to identify islands and their properties. A Geographic Information System (GIS) was used to evaluate historical aerial photographs dating back to 1937 for location, morphology, origin, and development of islands along an approximately 40 km study reach. Field studies included the surveying of cross sections to determine elevations of islands relative to neighboring floodplains, as well as pebble counts and cores to define sediment characteristics. Aerial photographs indicate that six islands had formed before and an additional 12 islands formed after 1937, placing the average island formation frequency at 0.005 islands per km per year since 1937. Field data indicate that elevation, grain size, stratigraphy, and vegetation of some islands closely resemble those of the floodplains supporting the hypothesis that those islands formed through cutoff, while one island’s sediment was similar to that of the channel and did not show similarities to floodplains or any other islands indicating formation through in-channel sediment deposition. Studies of bank erosion rates along the South River demonstrate that 33% of bank erosion along the South River occurs in divided reaches of the channel associated with islands. Understanding the formation and evolution of these islands may allow for an accurate prediction of future

  7. Dynamic scaling and kinetic roughening of poly(ethylene) islands grown by vapor phase deposition

    Czech Academy of Sciences Publication Activity Database

    Choukourov, A.; Melnichuk, I.; Gordeev, I.; Kylián, O.; Hanuš, J.; Kousal, J.; Solař, P.; Hanyková, L.; Brus, Jiří; Slavínská, D.; Biederman, H.

    2014-01-01

    Roč. 565, 28 August (2014), s. 249-260. ISSN 0040-6090 Institutional support: RVO:61389013 Keywords : poly(ethylene) * physical vapor deposition * island growth Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.759, year: 2014

  8. High Temperature Multilayer Environmental Barrier Coatings Deposited Via Plasma Spray-Physical Vapor Deposition

    Science.gov (United States)

    Harder, Bryan James; Zhu, Dongming; Schmitt, Michael P.; Wolfe, Douglas E.

    2014-01-01

    Si-based ceramic matrix composites (CMCs) require environmental barrier coatings (EBCs) in combustion environments to avoid rapid material loss. Candidate EBC materials have use temperatures only marginally above current technology, but the addition of a columnar oxide topcoat can substantially increase the durability. Plasma Spray-Physical Vapor Deposition (PS-PVD) allows application of these multilayer EBCs in a single process. The PS-PVD technique is a unique method that combines conventional thermal spray and vapor phase methods, allowing for tailoring of thin, dense layers or columnar microstructures by varying deposition conditions. Multilayer coatings were deposited on CMC specimens and assessed for durability under high heat flux and load. Coated samples with surface temperatures ranging from 2400-2700F and 10 ksi loads using the high heat flux laser rigs at NASA Glenn. Coating morphology was characterized in the as-sprayed condition and after thermomechanical loading using electron microscopy and the phase structure was tracked using X-ray diffraction.

  9. Shorebird Use of Coastal Wetland and Barrier Island Habitat in the Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Kim Withers

    2002-01-01

    Full Text Available The Gulf Coast contains some of the most important shorebird habitats in North America. This area encompasses a diverse mixture of estuarine and barrier island habitats with varying amounts of freshwater swamps and marshes, bottomland hardwood forests, and coastal prairie that has been largely altered for rice and crawfish production, temporary ponds, and river floodplain habitat. For the purposes of this review, discussion is confined to general patterns of shorebird abundance, distribution, and macro- and microhabitat use in natural coastal, estuarine, and barrier island habitats on the Gulf of Mexico Coast. The following geographic regions are considered: Northwestern Gulf (Rio Grande to Louisiana-Mississippi border, Northeastern Gulf (Mississippi to Florida Keys, and Mexico (Rio Grande to Cabo Catoche [Yucatan Strait].

  10. Groundwater ages, recharge conditions and hydrochemical evolution of a barrier island freshwater lens (Spiekeroog, Northern Germany)

    OpenAIRE

    Roeper, T; K. F. Kroeger; Meyer, Hanno; Sueltenfuss, J.; Greskowiak, J.; Massmann, G

    2012-01-01

    Freshwater lenses below barrier islands are dynamic systems affected by changes in morphodynamic patterns, groundwater recharge and discharge. They are also vulnerable to pollution and overabstraction of groundwater. Basic knowledge on hydrogeological and hydrochemical processes of freshwater lenses is important to ensure a sustainable water management, especially when taking into account possible effects of climate change. This is the first study which gives a compact overview on...

  11. Islands in a European mountain river: Linkages with large wood deposition, flood flows and plant diversity

    Science.gov (United States)

    Mikuś, Paweł; Wyżga, Bartłomiej; Kaczka, Ryszard J.; Walusiak, Edward; Zawiejska, Joanna

    2013-11-01

    Vegetated islands are characteristic landforms of braided mountain rivers. Long-term observations and recent morphological and botanical surveys conducted in the gravel-bed Czarny Dunajec, Polish Carpathians, were used to determine the processes and patterns governing initiation and development of islands and their floristic complexity. Moreover, dendrochronologically estimated years of island inception were compared with the timing and magnitude of flood flows in the period 1970-2011 to infer about controls on the formation and persistence of islands in the river. In the high-energy, braided river, islands originate as a result of deposition of large vegetative particles, mostly large wood, on gravel bars and the associated vegetative regeneration of living wood or the growth of seedlings and saplings in the shelter of wood accumulations. Tree-ring dating of the largest trees growing in particular zones of building and established islands indicated a predominant upstream island growth in the river. It results from repeated accumulation of living wood on the head of islands and its subsequent regeneration and contrasts with the progressive downstream growth of islands in the rivers supplied with large, stable logs of the tree species without the capability to re-sprout. The lack of islands from the years 1982-1996 most likely reflects the removal of relatively young islands by two major floods in the 1990s which were, however, unable to destroy older and larger islands. After 1997 the occurrence of low to moderate floods facilitated the formation and persistence of islands. The plant inventory demonstrated that species richness increased non-linearly with the increasing age, area and shoreline length of islands. Islands supported more plant species than the riparian forest and attained comparable species richness at an early stage of development. Fast developing, dynamic and supporting rich plant communities, islands contribute highly to the overall floristic

  12. 2007 USGS/NPS/NASA Experimental Advanced Airborne Research Lidar (EAARL): Northern Gulf of Mexico Barrier Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the northern Gulf of Mexico barrier islands and Naval Live Oaks was produced from...

  13. Packaging barrier films deposited on PET by PECVD using a new high density plasma source

    International Nuclear Information System (INIS)

    Barrier films for packaging applications are deposited by plasma enhanced chemical vapor deposition (PECVD) on PET film using a new, high density plasma source. The new source, termed the Penning Discharge Plasma source, implements a novel magnetic field/electrode configuration that confines the electron Hall current in an endless loop adjacent to the substrate. By confining the Hall current, a dense, uniform plasma is created and sustained over wide substrates. The result is high rate deposition at low substrate temperatures. The water vapor permeation of SiO2 barrier films is reported as well as deposition rate, coating thickness and other film properties

  14. Fire vs Water: Erosional/Depositional Geology, Hawaiian Islands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Even a casual, untrained observer will see evidence that opposing forces have formed the Hawaiian Islands. The massive and lofty volcanoes have been scoured,...

  15. Atomic layer deposition growth of a novel mixed-phase barrier for seedless copper electroplating applications

    International Nuclear Information System (INIS)

    A novel plasma-enhanced atomic layer deposition-grown mixed-phase/nanolaminate Ru-TaN barrier has been investigated, and it was confirmed that the copper diffusion barrier and direct-plate characteristics of the mixed-phase barrier can be modulated by varying the metal ratio in the film. This liner was subsequently optimized to yield a composition that combines the robust barrier properties of TaN with direct-plate characteristics of Ru. It was found that the deposited multicomponent system consists of individual crystalline and amorphous phase regions distributed across the barrier. The resulting optimized mixed-phase barrier was found to exhibit excellent copper diffusion barrier characteristics in layers as thin as 2 nm. A high degree of (111) texture (>84%) was observed for the direct-plated copper on this Ru-TaN barrier, which was very similar to the electroplated Cu deposited on a physical vapor deposition copper-seed control sample. Additionally, the filling characteristics in sub-50-nm features were found to be equivalent to those of conventionally copper-seeded interconnect structures.

  16. Transparent conductive gas-permeation barriers on plastics by atomic layer deposition.

    Science.gov (United States)

    Chou, Chun-Ting; Yu, Pei-Wei; Tseng, Ming-Hung; Hsu, Che-Chen; Shyue, Jing-Jong; Wang, Ching-Chiun; Tsai, Feng-Yu

    2013-03-25

    A mixed-deposition atomic layer deposition process produces Hf:ZnO films with uniform dopant distribution and high electrical conductivity (resistivity = 4.5 × 10(-4) W cm), optical transparency (>85% from 400-1800 nm), and moisture-barrier property (water vapor transmission rate = 6.3 × 10(-6) g m(-2) day(-1)). PMID:23386315

  17. Barriers to establish e-business for developing tourism industry: A case study of Kish Island

    Directory of Open Access Journals (Sweden)

    Ardeshir Tajzadeh Namin

    2012-04-01

    Full Text Available In this paper, we present an empirical study for ranking different barriers on developing e-business in one of the free zones called Kish Island in. This Island is located in south part of Iran and it is one of the most beautiful free zones of this country with tremendous opportunities for tourism industry. The proposed study gathers important factors in five different groups of economical, social and cultural, political, technology and software packages. In each group, decision makers determine various influencing factors and after three rounds of brainstorming, analytical hierarchy process is used to rank these factors. Based on the results, the lack of a good infrastructure (0.206, the lack of good culture among ordinary people to use e-businesses (0.205, the lack of good knowledge on internet services among ordinary people (0.204 are some of the most important factors preventing e-business in this region.

  18. Non-deposit system option for waste management on small islands.

    Science.gov (United States)

    Vilms, Monica; Voronova, Viktoria

    2016-08-01

    This paper analyses waste management on small islands (on a global scale these are micro-islands). In the context of the paper, small islands are islands that have an area less than 50 km(2) The study presents an overview of the problems connected with waste transport from islands to the mainland. Waste generation on islands is very much related to tourists. If tourists do not handle waste properly, it will cause problems. Four small Estonian islands in the range of 3-19 km(2) are studied in detail. For these and other small islands, the main problem is the waste produced by tourists, or related to tourists and waste transport to the mainland. Currently, the local municipality has to arrange and finance waste transport. In fact, and based on the polluter-pays principle, the tourists should bear the cost of waste management. There are different tax options available in order to collect the money from tourists - waste tax, harbour tax, tourist tax, donations, environmental tax and others. The study results revealed that the best possible solution for Estonian islands may be a non-deposit system - including an additional charge on ferry ticket prices. The extra money should cover the costs of waste management and waste shipping. The tourists arriving in their own boats should pay a harbour tax, which includes a waste tax to compensate for the cost of waste management. PMID:27344037

  19. Canopy penetration and deposition of barrier sprays from electrostatic and conventional sprayers.

    Science.gov (United States)

    Hoffmann, W C; Farooq, M; Walker, T W; Fritz, B; Szumlas, D; Quinn, B; Bernier, U; Hogsette, J; Lan, Y; Huang, Y; Smith, V L; Robinson, C A

    2009-09-01

    An experimental study was conducted to investigate the usefulness of electrostatic and conventional sprayers for barrier applications. Two conventional and three electrostatic sprayers were used in the study. Usefulness of the sprayers was rated based on penetration of spray into and deposition onto 2 sides of leaves on natural vegetation. Bifenthrin (Talstar adulticide) was applied at labeled rate, fluorescent dye was added to the tank mix as tracer, and all sprayers applied the dye and insecticide at the same rate. The results indicated that sprayers producing larger droplets produced significantly higher deposition on vegetation in barrier applications than the sprayers producing smaller droplets. Sprayers with higher air velocity at the nozzle discharge proved significantly better for barrier sprays than the sprayers with lower air velocity. Electrostatic sprayers did not show any improvement in deposition on vegetation or in penetration into vegetation over the conventional sprayers. There was no difference in deposition between truck-mounted and backpack sprayers. PMID:19852223

  20. Fallout deposition in the Marshall Islands from Bikini and Enewetak nuclear weapons tests.

    Science.gov (United States)

    Beck, Harold L; Bouville, André; Moroz, Brian E; Simon, Steven L

    2010-08-01

    Deposition densities (Bq m(-2)) of all important dose-contributing radionuclides occurring in nuclear weapons testing fallout from tests conducted at Bikini and Enewetak Atolls (1946-1958) have been estimated on a test-specific basis for 32 atolls and separate reef islands of the Marshall Islands. A complete review of various historical and contemporary data, as well as meteorological analysis, was used to make judgments regarding which tests deposited fallout in the Marshall Islands and to estimate fallout deposition density. Our analysis suggested that only 20 of the 66 nuclear tests conducted in or near the Marshall Islands resulted in substantial fallout deposition on any of the 23 inhabited atolls. This analysis was confirmed by the fact that the sum of our estimates of 137Cs deposition from these 20 tests at each atoll is in good agreement with the total 137Cs deposited as estimated from contemporary soil sample analyses. The monitoring data and meteorological analyses were used to quantitatively estimate the deposition density of 63 activation and fission products for each nuclear test, plus the cumulative deposition of 239+240Pu at each atoll. Estimates of the degree of fractionation of fallout from each test at each atoll, as well as of the fallout transit times from the test sites to the atolls were used in this analysis. The estimates of radionuclide deposition density, fractionation, and transit times reported here are the most complete available anywhere and are suitable for estimations of both external and internal dose to representative persons as described in companion papers. PMID:20622548

  1. Monitoring seasonal bat activity on a coastal barrier island in Maryland, USA.

    Science.gov (United States)

    Johnson, Joshua B; Gates, J Edward; Zegre, Nicolas P

    2011-02-01

    Research on effects of wind turbines on bats has increased dramatically in recent years because of significant numbers of bats killed by rotating wind turbine blades. Whereas most research has focused on the Midwest and inland portions of eastern North America, bat activity and migration on the Atlantic Coast has largely been unexamined. We used three long-term acoustic monitoring stations to determine seasonal bat activity patterns on the Assateague Island National Seashore, a barrier island off the coast of Maryland, from 2005 to 2006. We recorded five species, including eastern red bats (Lasiurus borealis), big brown bats (Eptesicus fuscus), hoary bats (Lasiurus cinereus), tri-colored bats (Perimyotis subflavus), and silver-haired bats (Lasionycteris noctivagans). Seasonal bat activity (number of bat passes recorded) followed a cosine function and gradually increased beginning in April, peaked in August, and declined gradually until cessation in December. Based on autoregressive models, inter-night bat activity was autocorrelated for lags of seven nights or fewer but varied among acoustic monitoring stations. Higher nightly temperatures and lower wind speeds positively affected bat activity. When autoregressive model predictions were fitted to the observed nightly bat pass totals, model residuals>2 standard deviations from the mean existed only during migration periods, indicating that periodic increases in bat activity could not be accounted for by seasonal trends and weather variables alone. Rather, the additional bat passes were attributable to migrating bats. We conclude that bats, specifically eastern red, hoary, and silver-haired bats, use this barrier island during migration and that this phenomenon may have implications for the development of near and offshore wind energy. PMID:20364316

  2. Deposition of SiOx barrier films by O2/TMDSO RF-PECVD

    Institute of Scientific and Technical Information of China (English)

    Zhou Mei-Li; Fu Ya-Bo; Chen Qiang; Ge Yuan-Jing

    2007-01-01

    This paper reports that the SiOx barrier films are deposited on polyethylene terephthalate substrate by plasmaenhanced chemical vapour deposition (PECVD) for the application of transparent barrier packaging. The variations of O2/Tetramethyldisiloxane (TMDSO) ratio and input power in radio frequency (RF) plasma are carried out to optimize barrier properties of the SiOx coated film. The properties of the coatings are characterized by Fourier transform infrared,water wpour transmission rate (WVTR), oxygen transmission rate (OTR), and atomic force microscopy analysers. It is found that the O2/TMDSO ratio exceeding 2:1 and the input power over 200 W yield SiOx films with low carbon contents which can be good to the barrier (WVTR and OTR) properties of the SiOx coatings. Also, the film properties not only depend on oxygen concentration of the inlet gas mixtures and input power, but also relate to the surface morphology of the coating.

  3. Emergent littoral deposits in the eastern Canary Islands

    Science.gov (United States)

    Meco, Joaquin; Stearns, Charles E.

    1981-03-01

    K-Ar ages ( A. Abdel-Monem, P. D. Watkins, and P. W. Gast, 1971, American Journal of Science271, 490-521; this paper) and revised paleontological determinations ( J. Meco, 1977, "Los Strombus neogenos y cuatenarios del Atlantico euroafricano", Las Palmas, Ediciones del Excmo. Cabildo Insular de Gran Canaria) show that "Quaternary" ( R. Crofts, 1967, Quaternaria 9, 247-260; G. Lecointre, K. J. Tinkler, and G. Richards, 1967, Academy of Natural Science of Philadelphia Proceedings119, 325-344) littoral deposits on Lanzarote and Fuerteventura are early Pliocene and late Pleistocene. Early and middle Pleistocene strand lines are not represented. Early Pliocene littoral and marine deposits contain a characteristic fossil assemblage: Strombus coronatus, Nerità emiliana, Gryphaea virleti, Patella cf. intermedia, and Rothpletzia rudista. Differences in elevation record differential post-Pliocene uplift of the coastal platforms on which they lie. Late Pleistocene beach deposits at low elevations belong to two groups, an older with Strombus bubonius and a younger without. Differences in elevation of early Pliocene littoral deposits are reflected by differences in elevation of late Pleistocene beach deposits nearby.

  4. Joeropsididae Nordenstam, 1933 (Crustacea, Isopoda, Asellota from the Lizard Island region of the Great Barrier Reef, Queensland, Australia

    Directory of Open Access Journals (Sweden)

    Niel L. Bruce

    2015-03-01

    Full Text Available The marine isopod family Joeropsididae (Asellota is documented for the Lizard Island region of the Great Barrier Reef, Australia. Fifteen species of Joeropsis are recorded, including ten new species; descriptive notes are provided for five species that lacked adequate material for description. A revised family and genus diagnosis is presented together with comments on the most useful characters for species identification and a key to Joeropsis of the Lizard Island region.

  5. Evolution of the Rømø barrier island in the Wadden Sea: Impacts of sea-level change on coastal morphodynamics

    DEFF Research Database (Denmark)

    Clemmensen, Lars B; Andersen, Thorbjørn Joest; Johannessen, Peter;

    Sandy coastal barriers are abundant along most continents, and they are often intensively engineered to prevent erosion. Therefore, it is important to develop projections of the evolution of this coastal type in periods with changing climate and sea-level. We have used a multidisciplinary approach...... combining facies analysis of ground penetrating radar profiles and sediment cores, and optically stimulated luminescence dating to reconstruct the history of the Rømø barrier island (Denmark) over the past 8000 years. This approach allows us to develop a high resolution 2D reconstruction of the formation of......, and falling sea-level, whereas wash-over sedimentation was promoted during periods of rapid sea-level rise when shoreface, beach and coastal dune deposits were reworked. In contrast, lagoonal sedimentation has been relatively continuous and kept pace with the long-term Holocene sea-level rise. Our...

  6. The properties and performance of moisture/oxygen barrier layers deposited by remote plasma sputtering.

    OpenAIRE

    Brown, Hayley L.

    2015-01-01

    The development of flexible lightweight OLED devices requires oxygen/moisture barrier layer thin films with water vapour transmission rates (WVTR) of < 10-6 g/m2/day. This thesis reports on single and multilayer architecture barrier layers (mostly based on SiO2, Al2O3 and TiO2) deposited onto glass, Si and polymeric substrates using remote plasma sputtering. The reactive sputtering depositions were performed on Plasma Quest S500 based sputter systems and the morphology, nanostructure and comp...

  7. Morphological evolution of self-assembled SiGe islands based on a mixed-phase pre-SiGe island layer grown by ion beam sputtering deposition

    International Nuclear Information System (INIS)

    Highlights: • The economical ion beam sputtering deposition technique was employed in this work. • A mixed-phase pre-SiGe island sub-layer was inserted and its effects were identified. • An evolution model of regeneration and secondary growth of islands was proposed. • A new mechanism called “lateral atomic migration” in mixed-phase layer was proposed. • An overlap behavior which was different from the coarsening mechanism was observed. - Abstract: We present a study of the evolution of self-assembled SiGe islands grown on a microcrystalline Si (μc-Si)-based mixed-phase pre-SiGe island layer. Using atomic force microscopy, lots of new short islands with smaller diameters, high islands with transition dome (TD) shape, and super islands with ∼20 nm in height are observed after the Ge layer deposition. This anomalous experimental finding is well clarified by a model of regeneration and secondary growth. It is found that the density of the super islands increases rapidly at the initial stage when the Ge coverage exceeds ∼1.2 nm. This is essentially the result of the selective aggregation of Ge adatoms on the pre-SiGe island layer. The Ge content and stored strain in SiGe islands calculated based on Raman spectra decrease with the increase of the Ge coverage. It is demonstrated that the chemical potential difference-induced lateral atomic migration (LAM) from amorphous SiGe alloy into SiGe islands can be responsible for this phenomenon. The LAM also leads to the formation of very large dome islands. Finally, the overlap behavior of neighbor islands in the sample with 2.2 nm-thick Ge layer is explained by the combined action of denser nucleation centers, faster growth rates of super islands in lateral direction, and coarsening of neighbor small islands

  8. Spatial Distribution and Sedimentary Facies of the 2007 Solomon Islands Tsunami Deposits

    Science.gov (United States)

    Nakamura, Y.; Nishimura, Y.; Woodward, S.

    2007-12-01

    We conducted a field survey of the extent of damage, crustal deformation, and onshore deposits caused by 2007 Solomon Islands tsunami in Ghizo and adjacent islands in the western Solomon Islands, from 13th to 18th April, 2007. Our survey team was comprised of six Japanese and one American researcher. Three of us, the authors, mainly investigated tsunami deposits in three villages (Titiana, Suva, and Pailongge) in southern Ghizo Island. One member of our team re-investigated the deposits in June 2007. The tsunami generated sheet-like deposits of coral beach sand on the flat plain in Titiana. Beside the sea coast, the tsunami wave eroded ground surfaces and formed small scarps at 30 m from the sea. Just interior of the scarps, tsunami deposits accumulated up to 9 cm in thickness. The thickness decreased with distance from the sea and was also affected by microtopography. No sandy tsunami deposits were observed on the inland area between 170 m and 210 m from the sea. The upper boundary of inundation was recognized at about 210 m from the sea because of accumulation of driftwood and floating debris. In Suva and Pailongge, the outline of sand-sheet distribution is the same as it in Titiana. The tsunami had a maximum thickness of 10 cm and two or three sand layers are separated by thin humic sand layers. These humic layers were likely supplied from hillslopes eroded by the tsunami and transported by return-flows. These successions of deposits suggest that tsunami waves inundated at least two times. This is consistent with the number of large waves told by eyewitnesses. In the Solomon Islands, the plentiful rainfall causes erosion and resedimentation of tsunami deposits. Furthermore, the sedimentary structures will be destroyed by chemical weathering in warm and moist environment, and bioturbation by plants, animals, and human activities. The sedimentary structures had been preserved till the end of June 2007, but had already been penetrated by plant roots and sandpipes

  9. Direct Measurements of Island Growth and Step-Edge Barriers in Colloidal Epitaxy

    KAUST Repository

    Ganapathy, R.

    2010-01-21

    Epitaxial growth, a bottom-up self-assembly process for creating surface nano- and microstructures, has been extensively studied in the context of atoms. This process, however, is also a promising route to self-assembly of nanometer- and micrometer-scale particles into microstructures that have numerous technological applications. To determine whether atomic epitaxial growth laws are applicable to the epitaxy of larger particles with attractive interactions, we investigated the nucleation and growth dynamics of colloidal crystal films with single-particle resolution. We show quantitatively that colloidal epitaxy obeys the same two-dimensional island nucleation and growth laws that govern atomic epitaxy. However, we found that in colloidal epitaxy, step-edge and corner barriers that are responsible for film morphology have a diffusive origin. This diffusive mechanism suggests new routes toward controlling film morphology during epitaxy.

  10. An assessment of an environmental gradient using coral geochemical records, Whitsunday Islands, Great Barrier Reef, Australia

    International Nuclear Information System (INIS)

    Coral cores were collected along an environmental and water quality gradient through the Whitsunday Island group, Great Barrier Reef (Australia), for trace element and stable isotope analysis. The primary aim of the study was to examine if this gradient could be detected in coral records and, if so, whether the gradient has changed over time with changing land use in the adjacent river catchments. Y/Ca was the trace element ratio which varied spatially across the gradient, with concentrations progressively decreasing away from the river mouths. The Ba/Ca and Y/Ca ratios were the only indicators of change in the gradient through time, increasing shortly after European settlement. The Mn/Ca ratio responded to local disturbance related to the construction of tourism infrastructure. Nitrogen isotope ratios showed no apparent trend over time. This study highlights the importance of site selection when using coral records to record regional environmental signals.

  11. Elaboration of tin oxide nano-islands through post-deposition thermal treatment

    International Nuclear Information System (INIS)

    Tin dioxide (SnO2) films have been grown onto (006) sapphire substrates by sol–gel dip-coating using tin alkoxide solutions. It is shown, using transmission electron microscopy and atomic force microscopy, that the thickness of the layers is easily controlled with tin concentration. It can vary after the deposition process between few nanometers and few tens of nanometers according to the concentration of the precursor in the sol. A post-deposition thermal treatment forces the continuous precursor film to split into isolated islands. A decrease of the tin concentration in the precursor sol to 100 μM allows the formation of islands of a few nanometers (3 nm) in height and several tens of nanometers in diameter (30 nm). Such height value is very close to the Bohr radius of SnO2. - Highlights: • SnO2 films have been grown onto sapphire by sol–gel dip-coating. • The thickness of the layers is easily controlled with tin concentration. • The continuous precursor film splits into isolated islands after a thermal treatment. • SnO2 nano-islands of 3 nm have been synthesized by decreasing the tin concentration. • SnO2 nano-islands with such characteristics could be used for optical applications

  12. Localised human impacts on the Harataonga coastal landscape, Great Barrier Island, northern New Zealand

    International Nuclear Information System (INIS)

    Here we present results of analyses of sediment profiles and cores, and coprolites, from Harataonga Bay, Great Barrier Island. Using a range of analyses (sedimentological, plant microfossils, parasitological, microbial, and steroids and myoglobin) we concentrate on human impact and reconstruction of the geomorphology and vegetation of the near-shore environments. Two different sub--environments are represented: dunes and alluvial plain. Dune instability coincides with a major increase in disturbance-related plants (especially ground ferns) as a result of forest clearance. The present form of much of the Harataonga dunes and the swamp at the eastern end of the bay is directly a result of human impact, no earlier than 737 ± 178 14C yr BP. In the record from the alluvial plain of the main Harataonga watercourse, at the western end of the bay, it is difficult to clearly resolve sedimentary inputs that directly relate to human presence in this former tidal inlet that was open to storm surge and stream floods. The only exception is the slopewash materials forming the terrace surface, sediments of which bear pollen consistent with vegetation disturbance. The landforms are natural but the rate at which the tidal inlet was infilled to form a terrace was accelerated by human activity. The nature and timing of the localised human impacts at Harataonga are consistent with those observed elsewhere on Great Barrier Island and mainland New Zealand. Some of our techniques (e.g. bacteria, steroids) are newly applied to coprolites in New Zealand but none provided any useful information because of poor preservation. (author). 34 refs., 13 figs., 3 tabs

  13. Sedimentary characteristics of possible paleo-tsunami deposits in Shimanoura Island, Eastern Kyushu, Japan

    Science.gov (United States)

    Yamada, M.; Goto, K.; Shinozaki, T.; Fujino, S.

    2013-12-01

    According to the ancient documents and geological records, the Pacific coast of western Japan has been repeatedly affected by large tsunamis. Among the historical tsunamis, the AD 1707 Hoei earthquake tsunami was one of the well-documented events, and it is known that the 3.0-4.5 m high tsunami arrived at northeastern Kyushu, where our study site is located [Hatori, 1985]. One of the purposes of this study is to determine whether the AD 1707 Hoei earthquake tsunami deposits exist in our study site, because the distribution of its deposits in eastern Kyushu is barely known outside of Ryujin-lake [Matsuoka and Okamura, 2009]. In addition, the oldest tsunami record is the AD 1596 Keicho-Bungo earthquake tsunami, and little is known about prehistorical tsunamis in eastern Kyushu. Another purpose of this study is to unravel the history of tsunamis in our study site before AD 1596. Shimanoura Island, our study site, has a swampy flat behind a barrier spit. We conducted hand coring at 16 study points along a 200 m shore-perpendicular transect in the swamp and at four additional study points out of the transect. Samples were collected for grain-size analysis and radiocarbon dating. The 0-2.5 m sedimentary successions were composed mainly of organic-rich mud, but fine-medium sand with grading structure was observed just below the ground surface at all study points along the transect. These graded sand layers sometimes contain rip-up clasts, and their upper and lower boundaries were sharp. In addition, these sand layers showed both landward fining (0.89 φ at 72 m from the shoreline, 1.32 φ at 186 m from the shoreline) and landward thinning trend (20 cm at 72 m from the shoreline, 2 cm at 170 m from the shoreline). These trends imply that this sand sheet was probably formed by some event associated with a seawater inundation. Adding to the landward thinning and fining sand layer, there were 11 sand layers at a depth of 1-2 m at one of the four study points out of the

  14. Diamond-like films deposited in the plasma of barrier and surface discharges at atmospheric pressure

    International Nuclear Information System (INIS)

    The structure and properties were investigated of carbon coatings deposited in the plasma of barrier and surface discharges at atmospheric pressure. To examine the structure of the coatings, methods of transmission electron microscopy and electron diffraction analysis were used. The coatings produced in a barrier discharge in methane and in acetylene-hydrogen mixtures are similar in chemical and phase composition to amorphous diamond-like carbon films produced at low pressures by conventional deposition techniques. However, the coatings have a significant number of defects, evidently caused by the inherent microstructure of the barrier discharge. From this point of view, the use of a surface discharge is much more promising. The coatings produced in a surface discharge have almost no microdefects and both the spatial distribution of the energy delivered to the discharge and the transport of film-forming particles towards the substrate are more efficient. (J.U.)

  15. Evidence for long-term uplift on the Canary Islands from emergent Mio Pliocene littoral deposits

    Science.gov (United States)

    Meco, Joaquín; Scaillet, Stéphane; Guillou, Hervé; Lomoschitz, Alejandro; Carlos Carracedo, Juan; Ballester, Javier; Betancort, Juan-Francisco; Cilleros, Antonio

    2007-06-01

    Several islands in the Canarian archipelago show marine deposits with identical fossil faunas, which are generally assigned to different glacioeustatic marine episodes: mainly Pleistocene episodes in Lanzarote and Fuerteventura, and Mio-Pliocene ones in Gran Canaria. Three fossil species ( Saccostrea chili, Nerita emiliana and Strombus coronatus) characterize all the marine deposits from southern Lanzarote, to the west and south of Fuerteventura and northeast of Gran Canaria. Three other species ( Ancilla glandiformis, Rothpletzia rudista and Siderastraea miocenica) confirm the chronostratigraphic attribution of these deposits. Other more occasional fossils (as Chlamys latissima, Isognomon soldanii and Clypeaster aegyptiacus) fit an upper Miocene and lower Pliocene age. This agrees with new K/Ar ages obtained from pillow lavas emplaced into the marine deposits (ca. 4.1 Ma in Gran Canaria, ca. 4.8 Ma in Fuerteventura) and from underlying (ca. 9.3 Ma in Gran Canaria) or overlying (ca. 9.8 Ma in Lanzarote) lava flows. The marine deposits are eroded but large continuous segments are preserved sloping gently towards the coast. Variations in the highest and the lowest elevations of the deposits apsl (above present sea level) indicate post-depositional uplift movements. Glacioeustatic causes are unlikely to be responsible for these variations on the basis of the coastal location of the deposits and their equatorial fauna characteristic of Mio-Pliocene corals. Differential uplift of the deposits across the archipelago is argued to result from the progressive seaward tilting of the islands along the insular volcanic trail marking the westward migration of hot spot head since 20 Ma. Successive westward accretion of younger volcanic edifices resulted in increasing lithostatic load of the crust with progressive (diachronous) tilting of the older edifices and their palaeo-shorelines marked by past coastal deposits.

  16. Using hot wire and initiated chemical vapor deposition for gas barrier thin film encapsulation

    International Nuclear Information System (INIS)

    Hot wire CVD (HWCVD) and initiated CVD (iCVD) are very well suited deposition techniques for the fabrication of transparent thin film gas barriers. Single inorganic or organic layers, however, face challenges, which are hard to overcome: unavoidable defects and low intrinsic barrier function. We demonstrate that by combining inorganic HWCVD films and organic iCVD films, a water vapor transmission rate a low as 5 ∗ 10−6 g/m2/day at 60 °C and 90% RH for a simple pinhole free three layer structure is obtained even with non-optimized individual layers. Given the 100 °C deposition temperature, the layer stacks can be deposited on any sensitive electronic device

  17. The application of GPR to barrier-lagoon sedimentation study in Boao of Hainan Island

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Sedimentary successions and internal structure of the coastal barrier-lagoon system of Boao,eastern Hainan Island were studied through utilizing data from test holes and trenches and ground-penetrating-radar (GPR) profiles. During late Pleistocene, fluvial and delta plains developed over an unevenly eroded bedrock during low sea level stand, followed by the formation of littoral and lagoon facies and defined coastal barrier-lagoon-estuary system during the post-glacial uppermost Pleistocene-lower Holocene eustatic rise of the sea level, and the upper Holocene high stand. GPR results show that Yudaitan, a sandy coastal bar backed by a low-laying land (shoal) just east of the active lagoon, is a continuous, parallel and slightly-wavy reflectors indicating homogeneous sandy or sandy gravel sediments, and inclined reflectors partly caused by progradation and accumulation of beach sand and gravel. Quasi-continuous, hummocky and chaotic reflectors from the shoal of Nangang village correspond to mixed accumulation of sands and clay. This research indicates the GPR is a non-intrusive, rapid, and economical method for high-resolution profiling of subsurface sediments in sandy gravelly coast.

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

    Science.gov (United States)

    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

  19. Spatial and seasonal atmospheric PAH deposition patterns and sources in Rhode Island

    Science.gov (United States)

    Schifman, Laura A.; Boving, Thomas B.

    2015-11-01

    Polycyclic aromatic hydrocarbons (PAH) enter the environment through various combustion processes and can travel long distances via atmospheric transport. Here, atmospheric PAH deposition was measured in six locations throughout Rhode Island using passive atmospheric bulk-deposition samplers for three years. The measurements were evaluated using two source-specific PAH isomer signatures, a multivariate receptor model, and an innovative contamination index that is weighted based on PAH contamination, number of detected compounds, and toxicity. Urban areas had significantly higher deposition rates (up to 2261 μg m-2 yr-1 ∑PAH) compared to peri-urban, coastal, and rural areas (as low as 73.6 μg m-2 yr-1 ∑PAH). In fall and winter, PAH deposition was up to 10 times higher compared to summer/spring. On an annual basis a total of 3.64 t yr-1 ∑PAH (2256.9 μg yr-1 m-2 ∑PAH) are estimated to be deposited atmospherically onto Rhode Island. Both, the analysis using isomer ratios and the statistical analysis using positive matrix factorization agreed on source identification. Overall gasoline, petrodiesel, and oil combustion sources were identified in all samples year-round while wood combustion associated PAH deposition was only detected during the cold season.

  20. Avifaunal changes revealed in Quaternary deposits near Waitomo Caves, North Island, New Zealand

    International Nuclear Information System (INIS)

    Late Pleistocene (23,000-10,000 14C yr BP) and Holocene (10,000 14C yr - present BP) avifaunas are described from the Henry Lambert and associated passages in Gardners Gut Cave, Waitomo Caves, North Island, New Zealand. Nine radiocarbon dates on bones and three uranium series dates on speleothems support the dating of the sites. These data are augmented by six new dates and reanalysis of the avifaunas from F1c Cave, also in the Waitomo karst. A distinctive Pleistocene avifauna characterised by the moa Euryapterix curtus and Pachyornis mappini and the North Island goose (Cnemiornis gracilis) with common associates including New Zealand coot (Fulica prisca), North Island takahe (Porphyrio mantelli), Finsch's duck (Euryanas finschi), and North Island kokako (Callaeas wilsoni) was present. The presence of kokako, saddleback (Philesturnus rufusater), and robin (Petroica longipes) in the Pleistocene deposits and the absence of grassland taxa such as pipit (Anthus noveaseelandiae) and quail (Coturnix novaezelandiae) indicate that the vegetation about Gardners Gut Cave included tall shrubland and probably lacked much grassland, even over the Last Glacial Maximum. The Holocene at Waitomo was characterised by a moa fauna dominated by Anomalopteryx didiformis, although both Euryapteryx curtus and Pachyornis mappini persisted in small numbers. The frequent occurrence of kakapo (Strigops habroptilus), weka (Gallirallus australis), and brown teal (Anas chlorotis) typifies Holocene avifaunas; Cnemiornis and Fulica are unknown from Holocene deposits in the area. (author). 45 refs., 7 figs., 8 tabs

  1. Enhancement of metal - semiconductor barrier height with superthin silicon dioxide films deposited on gallium arsenide by liquid phase deposition

    International Nuclear Information System (INIS)

    This study presents a method for surface passivation using silicon dioxide (SiO2). The proposed method has shown great effectiveness on metal - semiconductor barrier height enhancement. A high quality SiO2 layer is developed via liquid phase deposition, a method which naturally leaves a doping-level fluorine residue in the SiO2. The addition of fluorine to enhance the Schottky barrier height (SBH) is first discussed. Experimental results are presented. It is found that this fluorine addition enhances the Schottky barrier height, which allows a larger positive gate bias for enhancement mode metal - semiconductor field-effect transistors, thus permitting the fabrication of digital logic circuits with improved noise margins and relaxed tolerance with regard to device threshold voltage uniformity. The SBH to n-gallium arsenide (GaAS) is found to be approximately 0.7 eV. Finally, the effective barrier height of the metal - insulator - semiconductor structure reached 1.03 eV after annealing. The enhancement of SBH has been attributed to the formation of these stable interface layers. A model for fluorine-enhanced SiO2 SBH enhancement is also presented. [copyright] 2001 American Institute of Physics

  2. Schottky barriers based on metal nanoparticles deposited on InP epitaxial layers

    International Nuclear Information System (INIS)

    Fabrication of high-quality Schottky barriers on InP epitaxial layers prepared by liquid-phase epitaxy from rare-earth treated melts is reported. The Schottky structures are based on metal nanoparticles and a graphite layer deposited from colloidal solutions onto epitaxial layers with varying carrier concentration. The structures have notably high values of the barrier height and of the rectification ratio giving evidence of a small degree of the Fermi-level pinning. Electrical characteristics of these diodes are shown to be extremely sensitive to the exposure of gas mixtures with small hydrogen content. (paper)

  3. Schottky barriers based on metal nanoparticles deposited on InP epitaxial layers

    Science.gov (United States)

    Grym, Jan; Yatskiv, Roman

    2013-04-01

    Fabrication of high-quality Schottky barriers on InP epitaxial layers prepared by liquid-phase epitaxy from rare-earth treated melts is reported. The Schottky structures are based on metal nanoparticles and a graphite layer deposited from colloidal solutions onto epitaxial layers with varying carrier concentration. The structures have notably high values of the barrier height and of the rectification ratio giving evidence of a small degree of the Fermi-level pinning. Electrical characteristics of these diodes are shown to be extremely sensitive to the exposure of gas mixtures with small hydrogen content.

  4. High quality plasma enhanced chemical vapour deposited silicon oxide gas barrier coatings on polyester films

    International Nuclear Information System (INIS)

    Silicon oxide barrier coatings fabricated by a plasma enhanced chemical vapour deposition roll-to-roll process on polyester film have demonstrated impressive properties as a barrier to water vapour permeation. This study highlights the influence of the substrate on these coatings as we find that heat stabilised poly(ethylene terephthalate) (PET), with or without an additional acrylate primer layer, and poly(ethylene naphthalate) (PEN) produce superior composites than untreated PET film in terms of gas barrier. The barrier layers on PET and filled PET substrates, for which the barrier performance is within the detectable range of our measurement, have an activation energy to water permeation that increases with the thickness of the silica. For the thickest silica this is an increase of 26 kJ mol-1 over that from the uncoated substrate. We attribute this to the creation of highly tortuous, size-hindered pathways and the decoupling of defects as the coating is deposited in multiple passes. Using a more sensitive detection technique we measure a water vapour transmission rate value as low as 2 x 10-4 g m-2 day-1 for 1 μm thick coatings on PEN. Such a good barrier is observed for these thick coatings due to the high degree of carbon detected in the films that makes them less brittle than pure SiO2 layers. Substrate surface roughness is found to influence the morphology of the SiOx films but does not seem to adversely affect the barrier performance of the composites

  5. Barrier Island Dynamics Using Mass Center Analysis: A New Way to Detect and Track Large-Scale Change

    Directory of Open Access Journals (Sweden)

    Paul Paris

    2014-01-01

    Full Text Available A geographic information system (GIS was used to introduce and test a new method for quantitatively characterizing topographic change. Borrowing from classic Newtonian mechanics, the concept of a body’s center of mass is applied to the geomorphic landscape, and the barrier island environment in particular, to evaluate the metric’s potential as a proxy for detecting, tracking and visualizing change. Two barrier islands along North Carolina’s Outer Banks are used to test this idea: Core Banks, uninhabited and largely-undeveloped, and Hatteras Island, altered by the presence of a protective dune system. Findings indicate that for Core Banks, the alongshore change in the center of mass is in accord with dominate littoral transport and wind conditions. Cross-shore change agrees with independent estimates for the island migration rates. This lends credence to our assertion that the mass center metric has the potential to be a viable proxy for describing wholesale barrier migration and would be a valuable addition to the already-established ocean shoreline and subaerial volume metrics. More research is, however, required to demonstrate efficacy.

  6. Metal organic chemical vapor deposition of environmental barrier coatings for the inhibition of solid deposit formation from heated jet fuel

    Science.gov (United States)

    Mohan, Arun Ram

    Solid deposit formation from jet fuel compromises the fuel handling system of an aviation turbine engine and increases the maintenance downtime of an aircraft. The deposit formation process depends upon the composition of the fuel, the nature of metal surfaces that come in contact with the heated fuel and the operating conditions of the engine. The objective of the study is to investigate the effect of substrate surfaces on the amount and nature of solid deposits in the intermediate regime where both autoxidation and pyrolysis play an important role in deposit formation. A particular focus has been directed to examining the effectiveness of barrier coatings produced by metal organic chemical vapor deposition (MOCVD) on metal surfaces for inhibiting the solid deposit formation from jet fuel degradation. In the first part of the experimental study, a commercial Jet-A sample was stressed in a flow reactor on seven different metal surfaces: AISI316, AISI 321, AISI 304, AISI 347, Inconel 600, Inconel 718, Inconel 750X and FecrAlloy. Examination of deposits by thermal and microscopic analysis shows that the solid deposit formation is influenced by the interaction of organosulfur compounds and autoxidation products with the metal surfaces. The nature of metal sulfides was predicted by Fe-Ni-S ternary phase diagram. Thermal stressing on uncoated surfaces produced coke deposits with varying degree of structural order. They are hydrogen-rich and structurally disordered deposits, spherulitic deposits, small carbon particles with relatively ordered structures and large platelets of ordered carbon structures formed by metal catalysis. In the second part of the study, environmental barrier coatings were deposited on tube surfaces to inhibit solid deposit formation from the heated fuel. A new CVD system was configured by the proper choice of components for mass flow, pressure and temperature control in the reactor. A bubbler was designed to deliver the precursor into the reactor

  7. Modeling of early stages of island growth during pulsed deposition: Role of closed compact islands

    Czech Academy of Sciences Publication Activity Database

    Kotrla, Miroslav; Mašín, Martin

    New York: American Institute of Physics (AIP), 2011 - (Garrido, P.; Marro, J.; de los Santos, F.), s. 281-281. (AIP Conference Proceedings. 1332). ISBN 978-0-7354-0887-6. [Granada Seminar on Computational and Statistical Physics /11./. La Herradura, Granada (ES), 13.09.2010-17.09.2010] R&D Projects: GA ČR GA202/09/0775 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z10100521 Keywords : pulsed laser deposition * molecular beam epitaxial growth * Monte Carlo methods * diffusion Subject RIV: BM - Solid Matter Physics ; Magnetism http://dx.doi.org/ 10.1063/1.3569542

  8. Adhesion strength of sputter deposited diffusion barrier layer coatings for the use in U–Mo nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, W., E-mail: Wolfgang.Schmid@Areva.com; Dirndorfer, S.; Juranowitsch, H.; Kress, M.; Petry, W.

    2014-09-15

    Highlights: • Pull-off tests are used to assess the adhesion strength of nuclear fuel diffusion barriers. • Co-rolled, sputter deposited and C2TWP barriers are tested and compared. • Sputter deposited barriers show similar adhesion strength compared to other types. - Abstract: Advanced designs for high-density U–Mo/Al nuclear fuel feature an interfacial barrier layer between the U–Mo fuel bulk and the Al cladding, which is intended to avoid the formation of an irradiation induced diffusion layer (IDL). Sputter deposition was suggested as a method to apply such interfacial barriers to the U–Mo/Al fuel system. We investigated the adhesion strength of sputter deposited Ti, Zr, Zry-4, Nb and Ta barrier layers of 15–20 μm thickness in the U–Mo/Al system by pull-off tests. The adhesion strength is a measure for the robustness of a diffusion barrier layer against delaminating due to inner stresses. We found, that the adhesion strength of sputter deposited diffusion barrier layers is at least similar or even better compared to both the adhesion strength of barrier layers produced by the INL co-rolling process and the fuel-to-cladding adhesion strength achieved by the AREVA-CERCA C2TWP process.

  9. Surface modification of materials by dielectric barrier discharge deposition of fluorocarbon films

    Energy Technology Data Exchange (ETDEWEB)

    Liu Dongping, E-mail: Dongping.liu@dlnu.edu.c [School of Science, Dalian Nationalities University, Dalian 116600 (China); Yin Yejun [School of Science, Dalian Nationalities University, Dalian 116600 (China); School of Mechanical Engineering, Dalian Jiaotong University, Dalian 116021 (China); Li Dongming [School of Mechanical Engineering, Dalian Jiaotong University, Dalian 116021 (China); Niu Jinhai; Feng Zhixing [School of Science, Dalian Nationalities University, Dalian 116600 (China)

    2009-05-01

    Dielectric barrier discharges have been used to deposit fluorocarbon (FC) films on various materials, such as paper, glass, and silicon substrates. The primary monomers used for plasma polymerization were difluoromethane (CH{sub 2}F{sub 2}), octafluoropropane (C{sub 3}F{sub 8}), and octafluorocyclobutane (C{sub 4}F{sub 8}). FC films were characterized using Fourier transform infrared spectroscopy, atomic force microscopy, static contact angle measurements, and scanning electron microscopy. Surface and structural properties of deposited films are strongly dependent on the plasma compositions and plasma parameters. FC films deposited on paper are to enhance its barrier properties and to achieve hydrophobic surfaces. Contact angle studies reveal that a minimum FC film thickness of about 200 nm on paper is required to completely cover surface and near-surface fibers, thereby providing the paper with long term hydrophobic character. In the C{sub 3}F{sub 8} and C{sub 4}F{sub 8} systems, the contact angles of the deposited films do not change appreciably with plasma parameters and are strongly dependent on the substrate roughness. Hydrogenated FC films deposited with CH{sub 2}F{sub 2} plasmas show the relatively low contact angles due to the existence of CH{sub X} (x = 1-3) groups.

  10. Gas barrier properties of titanium oxynitride films deposited on polyethylene terephthalate substrates by reactive magnetron sputtering

    International Nuclear Information System (INIS)

    Titanium oxynitride (TiNxOy) films were deposited on polyethylene terephthalate (PET) substrates by means of a reactive radio frequency (RF) magnetron sputtering system in which the power density and substrate bias were the varied parameters. Experimental results show that the deposited TiNxOy films exhibited an amorphous or a columnar structure with fine crystalline dependent on power density. The deposition rate increases significantly in conjunction as the power density increases from 2 W/cm2 to 7 W/cm2. The maximum deposition rate occurs, as the substrate bias is -40 V at a certain power densities chosen in this study. The film's roughness slightly decreases with increasing substrate bias. The TiNxOy films deposited at power densities above 4 W/cm2 show a steady Ti:N:O ratio of about 1:1:0.8. The water vapor and oxygen transmission rates of the TiNxOy films reach values as low as 0.98 g/m2-day-atm and 0.60 cm3/m2-day-atm which are about 6 and 47 times lower than those of the uncoated PET substrate, respectively. These transmission rates are comparable to those of DLC, carbon-based and Al2O3 barrier films. Therefore, TiNxOy films are potential candidates to be used as a gas permeation barrier for PET substrate

  11. Polymer film deposition on agar using a dielectric barrier discharge jet and its bacterial growth inhibition

    Science.gov (United States)

    Tsai, T.-C.; Cho, J.; Mcintyre, K.; Jo, Y.-K.; Staack, D.

    2012-08-01

    Polymer film deposition on agar in ambient air was achieved using the helium dielectric barrier discharge jet (DBD jet) fed with polymer precursors, and the bacterial growth inhibition due to the deposited film was observed. The DBD jet with precursor addition was more efficient at sterilization than a helium-only DBD jet. On the areas where polymer films cover the agar the bacterial growth was significantly inhibited. The inhibition efficacy showed dependence on the film thickness. The DBD jet without precursor also created a modified agar layer, which may slow the growth of some bacterial strains.

  12. Evaluation of Atomic Layer Deposition coating as gas barrier against hydrogen gas and humidity

    International Nuclear Information System (INIS)

    Graphical abstract: ALD coating can provide a continuous and conformal barrier between the substrate and ambient atmosphere. - Abstract: Effectiveness of HfO2 Atomic Layer Deposition coatings has been studied on ZnO varistors by I–V tests, impedance spectroscopy, and highly accelerated life test. Based on impedance spectroscopy analyses, the proton diffusion coefficient was measured to be 400 K times less in the coating. Transmission electron microscopy analysis shows that Atomic Layer Deposition films are continuous and conformal. After exposure to high temperature, partial crystallization was detected in the coating and increases proton diffusion coefficient by 150 times

  13. Oscillatory barrier-assisted Langmuir-Blodgett deposition of large-scale quantum dot monolayers

    Science.gov (United States)

    Xu, Shicheng; Dadlani, Anup L.; Acharya, Shinjita; Schindler, Peter; Prinz, Fritz B.

    2016-03-01

    Depositing continuous, large-scale quantum dot films with low pinhole density is an inevitable but nontrivial step for studying their properties for applications in catalysis, electronic devices, and optoelectronics. This rising interest in high-quality quantum dot films has provided research impetus to improve the deposition technique. We show that by incorporating oscillatory barriers in the commonly used Langmuir-Blodgett method, large-scale monolayers of quantum dots with full coverage up to several millimeters have been achieved. With assistance of perturbation provided by the oscillatory barriers, the film has been shown to relax towards thermal equilibrium, and this physical process has been supported by molecular dynamics simulation. In addition, time evolution of dilatational moduli has been shown to give a clear indication of the film morphology and its stability.

  14. Deuterium post-metallization anneal of electrochemical-plated Cu film deposited on different barrier materials

    International Nuclear Information System (INIS)

    In this paper, we report on electrochemical-plated (ECP) copper (Cu) film characterizations with different (Ta, TaN and TiN) barrier materials subjected to post-metallization-annealing (PMA) in deuterium (D2) under various annealing conditions. For comparison, post-metallization-anneal of the ECP Cu film in pure nitrogen (N2) and forming gas (20% hydrogen+80% nitrogen) were also performed. We used four-point probe to determine the sheet resistance. Scanning electron microscopy was used to examine the surface morphology of the after-annealed ECP Cu films. X-ray-diffraction (XRD) analysis was used to inspect the texture of the ECP Cu films before and after PMA. The deuterium distribution in the barrier layer was determined by using the secondary ion mass spectroscopy depth profile analysis. We found that under appropriate PMA conditions, the sheet resistance of ECP Cu films deposited on TaN barrier was the lowest after D2 PMA when compared with those deposited on TiN and Ta barriers

  15. Tsunami hazard assessment in the southern Colombian Pacific Basin and a proposal to regenerate a previous barrier island as protection

    Directory of Open Access Journals (Sweden)

    L. J. Otero

    2013-04-01

    Full Text Available In this study, the tsunami hazard posed to 120 000 inhabitants of Tumaco (Colombia is assessed, and an evaluation and analysis of regenerating the previous El Guano Island for tsunami protection is conducted. El Guano Island was a sandy barrier island in front of the city of Tumaco until its disappearance during the tsunami of 1979; the island is believed to have played a protective role, substantially reducing the scale of the disaster. The analysis is conducted by identifying seismotectonic parameters and focal mechanisms of tsunami generation in the area, determining seven potential generation sources, applying a numerical model for tsunami generation and propagation, and evaluating the effect of tsunamis on Tumaco. The results show that in the current situation, this area is vulnerable to impact and flooding by tsunamis originating nearby. El Guano Island was found to markedly reduce flood levels and the energy flux of tsunami waves in Tumaco during the 1979 tsunami. To reduce the risk of flooding due to tsunamis, the regeneration and morphological modification of El Guano Island would help to protect Tumaco.

  16. Palynology, sedimentology and environmental significance of Holocene swamps at northern Kaitoke, Great Barrier Island, New Zealand

    International Nuclear Information System (INIS)

    Pollen and sediment analyses of two cores from coastal freshwater swamps at northern Kaitoke (Kaitoke Swamp and Police Station Swamp), Great Barrier Island, show that c. 7300 calibrated yr BP Kaitoke Swamp was an estuary with tidal flats. Avicennia, now absent from the swamp area, was present in the estuary. By c. 4500 yr BP fresh water conditions had developed at the Kaitoke Swamp site as marine influences decreased. Around the same time, fresh water swamp conditions commenced at the Police Station Swamp site on the surface of a low lying area of a Late Pleistocene dune. A sandy layer at Kaitoke may represent rapid infilling followed by a dry soil surface until c. 1000 yr BP. Conifer-hardwood forest on the hills surrounding the sites c. 7300-c. 1800 yr BP was dominated by Dacrydium and Metrosideros. During this period, environmental conditions were relatively stable, with little change in forest composition. Between 1800 yr and 800 yr BP Kaitoke Swamp was reflooded, and the Police Station Swamp extended as a shallow lake over the nearby dune flat. These new shallow swamps were invaded by swamp forest (mainly Dacrycaprus with some Laurelia). The presence of charcoal and Pteridium spores above the Kaharoa Tephra suggests that major Polynesian deforestation at northern Kaitoke began c. 600 calibrated yr BP. (author). 41 refs., 4 figs., 2 tabs

  17. Coral community responses to declining water quality: Whitsunday Islands, Great Barrier Reef, Australia

    Science.gov (United States)

    Thompson, Angus; Schroeder, Thomas; Brando, Vittorio E.; Schaffelke, Britta

    2014-12-01

    A five-year period (2002-2006) of below-median rainfall followed by a six-year period (2007-2012) of above-median rainfall and seasonal flooding allowed a natural experiment into the effects of runoff on the water quality and subsequent coral community responses in the Whitsunday Islands, Great Barrier Reef (Australia). Satellite-derived water quality estimates of total suspended solids (TSS) and chlorophyll- a (Chl) concentration showed marked seasonal variability that was exaggerated during years with high river discharge. During above-median rainfall years, Chl was aseasonally high for a period of 3 months during the wet season (February-April), while TSS was elevated for four months, extending into the dry season (March-June). Coinciding with these extremes in water quality was a reduction in the abundance and shift in the community composition, of juvenile corals. The incidence of coral disease was at a maximum during the transition from years of below-median to years of above-median river discharge. In contrast to juvenile corals, the cover of larger corals remained stable, although the composition of communities varied along environmental gradients. In combination, these results suggest opportunistic recruitment of corals during periods of relatively low environmental stress with selection for more tolerant species occurring during periods of environmental extremes.

  18. Research needs for strandplain/barrier island reservoirs in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Cole, E.L.; Fowler, M.L.; Salamy, S.P.; Sarathi, P.S.; Young, M.A.

    1994-12-01

    This report identifies reservoir characterization and reservoir management research needs and IOR process and related research needs for the fourth geologic class, strandplain/barrier island reservoirs. The 330 Class 4 reservoirs in the DOE Tertiary OH Recovery Information System (TORIS) database contain about 30.8 billion barrels of oil or about 9% of the total original oil-in-place (OOIP) in all United States reservoirs. The current projection of Class 4 ultimate recovery with current operations is only 38% of the OOIP, leaving 19 billion barrels as the target for future IOR projects. Using the TORIS database and its predictive and economic models, the recovery potential which could result from future application of IOR technologies to Class 4 reservoirs was estimated to be between 1.0 and 4.3 billion barrels, depending on oil price and the level of technology advancement. The analysis indicated that this potential could be realized through (1) infill drilling alone and in combination with polymer flooding and profile modification, (2) chemical flooding (surfactant), and (3) thermal processes. Most of this future potential is in Texas, Oklahoma, California, and the Rocky Mountain region. Approximately two-thirds of the potentially recoverable resource is at risk of abandonment by the year 2000, which emphasizes the urgent need for the development and demonstration of cost-effective recovery technologies.

  19. Effect of W addition on the electroless deposited NiP(W) barrier layer

    International Nuclear Information System (INIS)

    Electroless deposition of NiP, NiWP thin film on p-type Si as the barrier layer to prevent the diffusion of Cu into Si was investigated. The thermal stability of the Si/Ni(W)P/Cu layers were evaluated by measuring the changes of resistance of the samples after annealed at various temperatures. XRD was applied to detect the formation of Cu3Si and evaluate the barrier performance of the layers. The results of XRD of the stacked Si/NiP/Cu, Si/NiWP-1/Cu, Si/NiWP–2/Cu films reveal that Cu atom could diffuse through NiP barrier layer at 450 °C, Cu could hardly diffuse through NiWP layer at 550 °C. This means that with W added in the layer, the barrier performance is improved. Although the resistance of Si/NiWP-1 and Si/NiWP-2 are higher than that of Si/NiP, the resistance of stacked layers of Si/NiWP-1/Cu and Si/NiWP–2/Cu are close to that of Si/NiP/Cu. This means that using NiWP as barrier layer is acceptable.

  20. Sediment deposition rate in the Falefa River basin, Upolu Island, Samoa

    International Nuclear Information System (INIS)

    The 137Cs method was employed to investigate the recent historical rate of sediment deposition on a lowland alluvial floodplain in the Falefa River basin, Upolu Island, Samoa. Caesium stratigraphy in the floodplain sediment profile was clearly defined, with a broad peak at 145-175 cm depth. The measured rate of vertical accretion over the last 40 years is 4.0 ± 0.4 cm per year. This rate exceeds observations in humid environments elsewhere, but is similar to that recorded on other tropical Pacific Islands. Available flow data for the Vaisigano River in Samoa give a 'near-catastrophic' index value of 0.6 for flood variability. This is associated with the occurrence of tropical cyclones and storms in the Samoa area. Large floods therefore probably contribute to the high rate of floodplain sedimentation on Upolu Island. A small but growing body of evidence suggests that fluvial sedimentation rates on tropical Pacific islands are some of the highest in the world

  1. Barriers to reducing climate enhanced disaster risks in Least Developed Country-Small Islands through anticipatory adaptation

    Science.gov (United States)

    Kuruppu, N.; Willie, R.

    2015-12-01

    Small Island Developing States (SIDS) classified as Least Developed Countries (LDCs) are particularly vulnerable to the projected impacts of climate change. Given their particular vulnerabilities, climate adaptation investments are being made through both national and international efforts to build the capacity of various sectors and communities to reduce climate risks and associated disasters. Despite these efforts, reducing climate risks is not free of various challenges and barriers. This paper aims to synthesise a set of critical socio-economic barriers present at various spatial scales that are specific to Least Developed Country SIDS. It also aims to identify the processes that give rise to these barriers. Drawing on theories from natural hazards, a systematic literature review method was adopted to identify and organise the set of barriers by focussing both on academic papers and grey literature. The data revealed a notable lack of studies on adaptation within African and Caribbean LDC-SIDS. In general, there was a paucity of academic as well as grey literature being produced by authors from LDC-SIDS to challenge existing discourses related to adaptation barriers. The most common barriers identified included those related to governance, technical, cognitive and cultural. Three key findings can be drawn from this study in relation to formal adaptation initiatives. Firstly, the lack of focus on the adaptive capacity needs of Local Government or Island Councils and communities was a key barrier to ensuring success of adaptation interventions. Secondly, international adaptation funding modalities did little to address root causes of vulnerability or support system transformations. These funds were geared at supporting sectoral level adaptation initiatives for vulnerable natural resource sectors such as water, biodiversity and coastal zones. Thirdly, there is a need to recognise the significance of cultural knowledge and practices in shaping adaptive choices of

  2. Barriers to reducing climate enhanced disaster risks in Least Developed Country-Small Islands through anticipatory adaptation

    Directory of Open Access Journals (Sweden)

    Natasha Kuruppu

    2015-03-01

    Full Text Available Small Island Developing States (SIDS classified as Least Developed Countries (LDCs are particularly vulnerable to the projected impacts of climate change. Given their particular vulnerabilities, climate adaptation investments are being made through both national and international efforts to build the capacity of various sectors and communities to reduce climate risks and associated disasters. Despite these efforts, reducing climate risks is not free of various challenges and barriers. This paper aims to synthesise a set of critical socio-economic barriers present at various spatial scales that are specific to Least Developed Country SIDS. It also aims to identify the processes that give rise to these barriers. Drawing on theories from natural hazards, a systematic literature review method was adopted to identify and organise the set of barriers by focussing on both academic papers and grey literature. The data revealed a notable lack of studies on adaptation within African and Caribbean LDC-SIDS. In general, there was a paucity of academic as well as grey literature being produced by authors from LDC-SIDS to challenge existing discourses related to adaptation barriers. The most common barriers identified included those related to governance, technical, cognitive and cultural. Three key findings can be drawn from this study in relation to formal adaptation initiatives. Firstly, the lack of focus on the adaptive capacity needs of Local Government or Island Councils and communities was a key barrier to ensure success of adaptation interventions. Secondly, international adaptation funding modalities did little to address root causes of vulnerability or support system transformations. These funds were geared at supporting sectoral level adaptation initiatives for vulnerable natural resource sectors such as water, biodiversity and coastal zones. Thirdly, there is a need to recognise the significance of cultural knowledge and practices in shaping

  3. Topographic Lidar Survey of the Alabama, Mississippi, and Southeast Louisiana Barrier Islands, from September 5 to October 11, 2012 -- Bare Earth Digital Elevation Models

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A topographic lidar survey was conducted from September 5 to October 11, 2012, for the barrier islands of Alabama, Mississippi and southeast Louisiana, including...

  4. Topographic Lidar Survey of the Alabama, Mississippi, and Southeast Louisiana Barrier Islands, from September 5 to October 11, 2012 -- Classified Point Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This Data Series Report contains lidar elevation data collected September 5 to October 11, 2012, for the barrier islands of Alabama, Mississippi and southeast...

  5. Regularly arranged indium islands on glass/molybdenum substrates upon femtosecond laser and physical vapor deposition processing

    Science.gov (United States)

    Ringleb, F.; Eylers, K.; Teubner, Th.; Boeck, T.; Symietz, C.; Bonse, J.; Andree, S.; Krüger, J.; Heidmann, B.; Schmid, M.; Lux-Steiner, M.

    2016-03-01

    A bottom-up approach is presented for the production of arrays of indium islands on a molybdenum layer on glass, which can serve as micro-sized precursors for indium compounds such as copper-indium-gallium-diselenide used in photovoltaics. Femtosecond laser ablation of glass and a subsequent deposition of a molybdenum film or direct laser processing of the molybdenum film both allow the preferential nucleation and growth of indium islands at the predefined locations in a following indium-based physical vapor deposition (PVD) process. A proper choice of laser and deposition parameters ensures the controlled growth of indium islands exclusively at the laser ablated spots. Based on a statistical analysis, these results are compared to the non-structured molybdenum surface, leading to randomly grown indium islands after PVD.

  6. Dynamic competition between island growth and coalescence in metal-on-insulator deposition

    International Nuclear Information System (INIS)

    The morphology of thin metal films and nanostructures synthesized from the vapor phase on insulating substrates is strongly influenced by the coalescence of islands. Here, we derive analytically the quantitative criterion for coalescence suppression by combining atomistic nucleation theory and a classical model of coalescence. Growth simulations show that using this criterion, a coalescence-free growth regime can be reached in which morphological evolution is solely determined by island nucleation, growth, and impingement. Experimental validation for the ability to control the rate of coalescence using this criterion and navigate between different growth regimes is provided by in situ monitoring of Ag deposition on SiO2. Our findings pave the way for creating thin films and nanostructures that exhibit a wide range of morphologies and physical attributes in a knowledge-based manner.

  7. Peatland records of dust deposition from Middleton Island, Gulf of Alaska

    Science.gov (United States)

    Moy, C. M.; Crusius, J.; Schroth, A. W.; Nichols, J. E.; Peteet, D. M.; Kenna, T. C.; Giosan, L.; Eglinton, T. I.; Gassó, S.

    2011-12-01

    Iron is an important micronutrient that limits the growth of phytoplankton in much of the global ocean. In the Gulf of Alaska (GoA), we have a limited knowledge of the processes that transport iron, and in particular, the role eolian dust plays in delivering iron to the ocean surface. In order to better understand both modern and past mechanisms of dust deposition in the GoA, we examine satellite, NCEP reanalysis, and meteorological station data as well as geochemical data from peat cores collected from Middleton Island (59.43°N, 146.34°W). Widespread dust events have been observed in MODIS satellite imagery emanating from exposed floodplains within the Copper River valley and adjacent glaciated river valleys in southcentral Alaska (AK). Dust events are common in the fall when high pressure in the AK interior and low pressure in the central GoA establish a tight pressure gradient that drives anomalously strong northerly winds. Low river levels and limited snow coverage expose fine-grained glacial sediments that are entrained by winds. MODIS imagery indicates dust reaches beyond the continental shelf, and in many instances, dust plumes have been observed passing over Middleton Island (100 km SSW of the Copper River delta). To better constrain dust deposition from southcentral AK on geologic timescales, we collected cores from an extensive peat bog on Middleton Island, located at the edge of the continental shelf. X-ray imagery, bulk density, magnetic susceptibility, loss on ignition, and profiling XRF data indicate significant variations in inorganic or clastic components within the organic peat matrix. Because these cores were collected near the island's topographic high point, we infer that all inorganic constituents are likely delivered as dust, with potential secondary contributions from volcanic ash. We will present a well-dated, high-resolution scanning XRF profile that spans the last 5200 years and records downcore variations in terrigenous material that

  8. LITTER DEPOSITION AND DECOMPOSITION IN THREE FOREST FRAGMENTS PERIODICALLY FLOODABLE IN THE ISLAND OF MARAMBAIA, RJ

    OpenAIRE

    Ranieri Ribeiro Paula; Marcos Gervasio Pereira; Luiz Fernando Tavares de Menezes

    2009-01-01

    The litter production and decomposition of three sandy coastal plain forest formations periodically floodable in the Island of Marambaia, Mangaratiba, RJ, were studied from October 2005 to September 2006. For the litter deposition evaluation, 10 litter traps were installed and in each forest formation to quantify the litter decomposition 15 litter bags were allocated in each area. The annual litter production was 11.3, 10.8 and 11.1 Mg ha-1year-1, to F1, F2 and F3, respectively, the highest d...

  9. Runup parameterization and beach vulnerability assessment on a barrier island: a downscaling approach

    Directory of Open Access Journals (Sweden)

    G. Medellín

    2015-05-01

    Full Text Available We present a downscaling approach for the study of wave-induced extreme water levels at a location on a barrier island in Yucatan (Mexico. Wave information from a 30 year wave hindcast is validated with in situ measurements at 8 m water depth. The Maximum Dissimilarity Algorithm is employed for the selection of 600 representative cases, encompassing different wave characteristics and tidal level combinations. The selected cases are propagated from 8 m water depth till the shore using the coupling of a third-generation wave model and a phase-resolving non-hydrostatic Nonlinear Shallow Water Equations model. Extreme wave runup, R2%, is estimated for the simulated cases and can be further employed to reconstruct the 30 year period using an interpolation algorithm. Downscaling results show runup saturation during more energetic wave conditions and modulation owing to tides. The latter suggests that the R2% can be parameterized using a hyperbolic-like formulation with dependency on both wave height and tidal level. The new parametric formulation is in agreement with the downscaling results (r2 = 0.78, allowing a fast calculation of wave-induced extreme water levels at this location. Finally, an assessment of beach vulnerability to wave-induced extreme water level is conducted at the study area by employing the two approaches (reconstruction/parametrization and a storm impact scale. The 30 year extreme water level hindcast allows the calculation of beach vulnerability as a function of return periods. It is shown that the downscaling-derived parameterization provides reasonable results as compared with the numerical approach. This methodology can be extended to other locations and can be further improved by incorporating the storm surge contributions to the extreme water level.

  10. Gas barrier properties of titanium oxynitride films deposited on polyethylene terephthalate substrates by reactive magnetron sputtering

    Science.gov (United States)

    Lin, M.-C.; Chang, L.-S.; Lin, H. C.

    2008-03-01

    Titanium oxynitride (TiN xO y) films were deposited on polyethylene terephthalate (PET) substrates by means of a reactive radio frequency (RF) magnetron sputtering system in which the power density and substrate bias were the varied parameters. Experimental results show that the deposited TiN xO y films exhibited an amorphous or a columnar structure with fine crystalline dependent on power density. The deposition rate increases significantly in conjunction as the power density increases from 2 W/cm 2 to 7 W/cm 2. The maximum deposition rate occurs, as the substrate bias is -40 V at a certain power densities chosen in this study. The film's roughness slightly decreases with increasing substrate bias. The TiN xO y films deposited at power densities above 4 W/cm 2 show a steady Ti:N:O ratio of about 1:1:0.8. The water vapor and oxygen transmission rates of the TiN xO y films reach values as low as 0.98 g/m 2-day-atm and 0.60 cm 3/m 2-day-atm which are about 6 and 47 times lower than those of the uncoated PET substrate, respectively. These transmission rates are comparable to those of DLC, carbon-based and Al 2O 3 barrier films. Therefore, TiN xO y films are potential candidates to be used as a gas permeation barrier for PET substrate.

  11. Development of Diffusion barrier coatings and Deposition Technologies for Mitigating Fuel Cladding Chemical Interactions (FCCI)

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Allen, Todd; Cole, James

    2013-02-27

    The goal of this project is to develop diffusion barrier coatings on the inner cladding surface to mitigate fuel-cladding chemical interaction (FCCI). FCCI occurs due to thermal and radiation enhanced inter-diffusion between the cladding and fuel materials, and can have the detrimental effects of reducing the effective cladding wall thickness and lowering the melting points of the fuel and cladding. The research is aimed at the Advanced Burner Reactor (ABR), a sodium-cooled fast reactor, in which higher burn-ups will exacerbate the FCCI problem. This project will study both diffusion barrier coating materials and deposition technologies. Researchers will investigate pure vanadium, zirconium, and titanium metals, along with their respective oxides, on substrates of HT-9, T91, and oxide dispersion-strengthened (ODS) steels; these materials are leading candidates for ABR fuel cladding. To test the efficacy of the coating materials, the research team will perform high-temperature diffusion couple studies using both a prototypic metallic uranium fuel and a surrogate the rare-earth element lanthanum. Ion irradiation experiments will test the stability of the coating and the coating-cladding interface. A critical technological challenge is the ability to deposit uniform coatings on the inner surface of cladding. The team will develop a promising non-line-of-sight approach that uses nanofluids . Recent research has shown the feasibility of this simple yet novel approach to deposit coatings on test flats and inside small sections of claddings. Two approaches will be investigated: 1) modified electrophoretic deposition (MEPD) and 2) boiling nanofluids. The coatings will be evaluated in the as-deposited condition and after sintering.

  12. Enhanced Barrier Performance of Engineered Paper by Atomic Layer Deposited Al2O3 Thin Films.

    Science.gov (United States)

    Mirvakili, Mehr Negar; Van Bui, Hao; van Ommen, J Ruud; Hatzikiriakos, Savvas G; Englezos, Peter

    2016-06-01

    Surface modification of cellulosic paper is demonstrated by employing plasma assisted atomic layer deposition. Al2O3 thin films are deposited on paper substrates, prepared with different fiber sizes, to improve their barrier properties. Thus, a hydrophobic paper is created with low gas permeability by combining the control of fiber size (and structure) with atomic layer deposition of Al2O3 films. Papers are prepared using Kraft softwood pulp and thermomechanical pulp. The cellulosic wood fibers are refined to obtain fibers with smaller length and diameter. Films of Al2O3, 10, 25, and 45 nm in thickness, are deposited on the paper surface. The work demonstrates that coating of papers prepared with long fibers efficiently reduces wettability with slight enhancement in gas permeability, whereas on shorter fibers, it results in significantly lower gas permeability. Wettability studies on Al2O3 deposited paper substrates have shown water wicking and absorption over time only in papers prepared with highly refined fibers. It is also shown that there is a certain fiber size at which the gas permeability assumes its minimum value, and further decrease in fiber size will reverse the effect on gas permeability. PMID:27165172

  13. Deposition of hard thin films from HMDSO in atmospheric pressure dielectric barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Trunec, D; Zajickova, L; BursIkova, V; Studnicka, F; Stahel, P; Prysiazhnyi, V; Navratil, Z; Franta, D [Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Perina, V [Institute of Nuclear Physics, Academy of Sciences of the Czech Republic, 250 68 Rez (Czech Republic); Houdkova, J, E-mail: trunec@physics.muni.c [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Prague (Czech Republic)

    2010-06-09

    An atmospheric pressure dielectric barrier discharge burning in nitrogen with a small admixture of hexamethyldisiloxane (HMDSO) was used for the deposition of thin organosilicon films. The thin films were deposited on glass, silicon and polycarbonate substrates, and the substrate temperature during the deposition process was increased up to values within the range 25-150 {sup 0}C in order to obtain hard SiO{sub x}-like thin films. The properties of the discharge were studied by means of optical emission spectroscopy and electrical measurements. The deposited films were characterized by the Rutherford backscattering and elastic recoil detection methods, x-ray photoelectron spectroscopy, infrared spectroscopy measurements, ellipsometry and the depth sensing indentation technique. It was found that the films' properties depend significantly on the substrate temperature at deposition. An increase in substrate temperature from 25 to 150 {sup 0}C led to an increase in film hardness from 0.4 to 7 GPa and the film chemical composition changed from CH{sub x}Si{sub y}O{sub z} to SiO{sub x}H{sub y}. The films were transparent in the visible range.

  14. Atomic layer deposition on polymer based flexible packaging materials: Growth characteristics and diffusion barrier properties

    Energy Technology Data Exchange (ETDEWEB)

    Kaeaeriaeinen, Tommi O., E-mail: tommi.kaariainen@lut.f [ASTRaL, Lappeenranta University of Technology, Prikaatinkatu 3 E, 50100 Mikkeli (Finland); Maydannik, Philipp, E-mail: philipp.maydannik@lut.f [ASTRaL, Lappeenranta University of Technology, Prikaatinkatu 3 E, 50100 Mikkeli (Finland); Cameron, David C., E-mail: david.cameron@lut.f [ASTRaL, Lappeenranta University of Technology, Prikaatinkatu 3 E, 50100 Mikkeli (Finland); Lahtinen, Kimmo, E-mail: kimmo.lahtinen@tut.f [Tampere University of Technology, Paper Converting and Packaging Technology, P.O. Box 541, 33101 Tampere (Finland); Johansson, Petri, E-mail: petri.johansson@tut.f [Tampere University of Technology, Paper Converting and Packaging Technology, P.O. Box 541, 33101 Tampere (Finland); Kuusipalo, Jurkka, E-mail: jurkka.kuusipalo@tut.f [Tampere University of Technology, Paper Converting and Packaging Technology, P.O. Box 541, 33101 Tampere (Finland)

    2011-03-01

    One of the most promising areas for the industrial application of atomic layer deposition (ALD) is for gas barrier layers on polymers. In this work, a packaging material system with improved diffusion barrier properties has been developed and studied by applying ALD on flexible polymer based packaging materials. Nanometer scale metal oxide films have been applied to polymer-coated papers and their diffusion barrier properties have been studied by means of water vapor and oxygen transmission rates. The materials for the study were constructed in two stages: the paper was firstly extrusion coated with polymer film, which was then followed by the ALD deposition of oxide layer. The polymers used as extrusion coatings were polypropylene, low and high density polyethylene, polylactide and polyethylene terephthalate. Water vapor transmission rates (WVTRs) were measured according to method SCAN-P 22:68 and oxygen transmission rates (O{sub 2}TRs) according to a standard ASTM D 3985. According to the results a 10 nm oxide layer already decreased the oxygen transmission by a factor of 10 compared to uncoated material. WVTR with 40 nm ALD layer was better than the level currently required for most common dry flexible packaging applications. When the oxide layer thickness was increased to 100 nm and above, the measured WVTRs were limited by the measurement set up. Using an ALD layer allowed the polymer thickness on flexible packaging materials to be reduced. Once the ALD layer was 40 nm thick, WVTRs and O{sub 2}TRs were no longer dependent on polymer layer thickness. Thus, nanometer scale ALD oxide layers have shown their feasibility as high quality diffusion barriers on flexible packaging materials.

  15. Geochemical Characteristics of Typhoon - and Tsunami - Induced Deposits from Western Kyushu Islands

    Science.gov (United States)

    Kanamaru, K.; Woodruff, J. D.; Kundu, S.; Cook, T.

    2014-12-01

    Western Kyushu Island is a region of Japan frequently impacted by typhoon landfalls. This region is relatively tectonically stable with few active faults and therefore known for far fewer great earthquakes when compared to the Nankai Trough region. Only a few studies have examined the history of tsunamis impacting the region. Hence, studies from western Kyushu provide a unique opportunity to study tsunami deposits in a broader geographic context in order to delineate regional typhoon impacts. This study presents results from both modern analogue from Typhoon Neoguri in 2014 and legendary Kamikaze Typhoons from 13th century. The initial coring was conducted in 2010. Total of 9 sediment cores were collected from two natural freshwater lakes along the western coast of Kyushu: Lake Daija (32.248°N, 129.985°E) and Lake Kawahara (32.624°N, 129.831°E). In order to further understand the characteristics of typhoon deposits, we collected 4 additional sediment cores from Kawahara in July of 2014, approximately one week after landfall of Typhoon Neoguri. We use a multi-proxy approach to identify event deposits. These approaches include loss on ignition, X-Ray fluorescence, X-radiograph, grain size, magnetic susceptibility, and SEM/EDS analyses. Initial results yielded commonalities between the two lakes. Linear interpolation of the most prominent event deposits within multiple cores, presenting highs in Sr and Ca intensities, constrain the dates of deposits of interest to the late 13th century—consistent with the Mongol invasions. Here we present preliminary geochemical results from Lake Kawahara, which further constrain the typhoon deposits, and use this as a reference event for comparison to tsunami deposits found in other regions.

  16. Plasma surface treatments by using a dielectric barrier discharge for the deposition of diamond films

    Science.gov (United States)

    Kang, I. J.; Ko, M. G.; Yang, J. K.; Lee, H. J.

    2013-07-01

    For plasma surface treatments at atmospheric pressure, a 2 kW dielectric barrier discharge (DBD) source was developed. It was investigated via an optical emission spectroscopy (OES), an IR camera and volt-ampere meters with a computer. It was confirmed that the developed source stably generated plasmas. After the diamonds had been seeded, the plasma surface treatments were performed as pretreatment to improve the deposition of the diamond films by using the developed DBD source with argon gas. The substrate surfaces were analyzed using a contact angle analysis (CAA), an atomic force microscopy (AFM) and a 3D Nano Profiling System. The results of the plasma surface treatments showed an improvement in the surface free energies of the substrates. The plasma surface treatments for 5 minutes also resulted in a more uniform distribution of the seeding diamonds on the substrates, which improved the depositions of the diamond films.

  17. Investigation of failure mechanism of thermal barrier coatings (TBCs) deposited by EB-PVD technique

    International Nuclear Information System (INIS)

    Failure mechanism of thermal barrier coatings (TBCs) prepared by electron beam physical vapor deposition (EB-PVD) technique owing to formation of micro cracks was investigated. The TBCs were deposited on the Ni-based super alloy IN-100 and the micro cracks were observed within the top ceramic coat of thermally cycled TBCs at 1050°C. It was observed that these cracks propagate in the ceramic coat in the direction normal to interface while no cracks were observed in the bond coat. SEM/EDS studies revealed that some non-uniform oxides were formed on the interface between ceramic top and metallic bond coat just below the cracks. Study proposed that the cracks were initiated due to stress owing to big difference in Pilling-Bed worth ratio of non-uniform oxides as well as thermal stress, which caused the formation of cracks in top ceramic coat leading to failure of TBCs

  18. Influence of vegetation on spatial patterns of sediment deposition in deltaic islands during flood

    Science.gov (United States)

    Nardin, W.; Edmonds, D. A.; Fagherazzi, S.

    2016-07-01

    River deltas are shaped by the interaction between flow and sediment transport. This morphodynamic interaction is potentially affected by freshwater marsh vegetation (e.g. Sagittaria spp.and Typha spp. in the Mississippi delta, USA) on the exposed surfaces of emergent deltaic islands. The vulnerability of deltaic islands is a result of external forces like large storms, sea level rise, and trapping of sediment in upstream reservoirs. These factors can strongly determine the evolution of the deltaic system by influencing the coupling between vegetation dynamics and morphology. In the last few years, models have been developed to describe the dynamics of salt marsh geomorphology coupled with vegetation growth while the effect of freshwater vegetation on deltaic islands and marshes remains unexplored. Here we use a numerical flow and sediment transport model to determine how vegetation affects the spatial distribution of sediment transport and deposition on deltaic surfaces during flood. Our modeling results show that, for an intermediate value of relative vegetation height and density, sedimentation rate increases at the head of the delta. On the other hand, large values of relative vegetation height and density promote more sedimentation at the delta shoreline. A logical extension of our results is that over time intermediate values of relative vegetation height and density will create a steeper-sloped delta due to sediment trapping at the delta head, whereas relatively taller vegetation will create a larger, but flatter delta due to sediment deposition at the shoreline. This suggests intermediate relative vegetation height and density may create more resilient deltas with higher average elevations.

  19. Electroless copper deposition as a seed layer on TiSiN barrier

    International Nuclear Information System (INIS)

    Electroless deposition of copper as a seeding technology has received considerable attention in back-end-of-line device fabrication. This work explores the effects of plasma processing parameters such as argon gas flow rate and nitrogen plasma treatment time on the properties of electrolessly plated Cu on TiSiN barrier layers. The barrier film was produced by a low-frequency inductively coupled plasma process. The properties of deposited electroless copper are characterized by x-ray diffraction, four-point resistivity probe, atomic force microscopy, and field emission scanning electron microscope. The required palladium activation time is greatly reduced on TiSiN compared to TiN. In both cases there exists a preferred (111) crystal orientation in Cu film and the intensity ratio of I(111)/I(200) is very close. The Cu grain size is within the range of 23-34 nm for 84 nm thick film. It is found that argon gas flow rate does not have a significant effect on the resistivity of electroless copper film on TiSiN. However, increasing nitrogen plasma treatment time reduces the resistivity of copper film. The roughness of plated Cu layer largely follows the one of the underlying TiSiN. Good surface coverage of electroless Cu seed layer on TiSiN has been achieved in our experiment

  20. EAARL Coastal Topography-Mississippi and Alabama Barrier Islands, Post-Hurricane Gustav, 2008

    Science.gov (United States)

    Bonisteel-Cormier, J.M.; Nayegandhi, Amar; Wright, C.W.; Sallenger, A.H.; Brock, J.C.; Nagle, D.B.; Klipp, E.S.; Vivekanandan, Saisudha; Fredericks, Xan; Segura, Martha

    2010-01-01

    These remotely sensed, geographically referenced elevation measurements of lidar-derived bare-earth (BE) and first-surface (FS) topography datasets were produced collaboratively by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL; the National Park Service (NPS), Gulf Coast Network, Lafayette, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the Mississippi and Alabama barrier islands, acquired post-Hurricane Gustav (September 2008 hurricane) on September 8, 2008. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative airborne lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multispectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for sub-meter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the

  1. EAARL Coastal Topography-Eastern Louisiana Barrier Islands, Post-Hurricane Gustav, 2008: First Surface

    Science.gov (United States)

    Bonisteel-Cormier, J.M.; Nayegandhi, Amar; Wright, C.W.; Sallenger, A.H.; Brock, J.C.; Nagle, D.B.; Vivekanandan, Saisudha; Fredericks, Xan

    2010-01-01

    These remotely sensed, geographically referenced elevation measurements of lidar-derived first-surface (FS) topography datasets were produced collaboratively by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the eastern Louisiana barrier islands, acquired post-Hurricane Gustav (September 2008 hurricane) on September 6 and 7, 2008. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative airborne lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multispectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for sub-meter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed using

  2. Ge deposition on Si(1 0 0) in the conditions close to dynamic equilibrium between islands growth and their decay

    Science.gov (United States)

    Shklyaev, A. A.; Budazhapova, A. E.

    2016-01-01

    The formation of islands arrays during Ge deposition on Si(1 0 0) at high temperatures is studied using scanning tunneling and electron microscopies. It is found that the island size and shape distributions, which are known to be bimodal at growth temperatures below 700 °C, become monomodal at temperatures above 800 °C. The obtained data suggest that the processes such as island nucleation and Ostwald ripening become less significant in the surface morphology formation, giving the advantage to selective attachment of deposited Ge atoms to island sidewalls and spatially inhomogeneous Si-Ge intermixing, as the temperature increases. At 900 °C, the islands exhibit a tendency to form laterally ordered arrays when the growth conditions approach the dynamic equilibrium between the growth of islands and their decay by means of Si-Ge intermixing. The islands ordering is accompanied by their shape transformation into the cone with shallow sidewalls inclined from (1 0 0) by angles of around 10°.

  3. Hydrogeological characterisation of a glacially affected barrier island – the North Frisian Island of Föhr

    Directory of Open Access Journals (Sweden)

    T. Burschil

    2012-04-01

    Full Text Available We present the application of geophysical investigations to characterise and improve the geological/hydrogeological model through the estimation of petrophysical parameters for groundwater modelling. Seismic reflection and airborne electromagnetic surveys in combination with borehole information enhance the 3-D geological model and allow a petrophysical interpretation of the subsurface.

    The North Sea Island of Föhr has a very complex underground structure what was already known from boreholes. The local waterworks use a freshwater body embedded in saline groundwater. Several glaciations disordered the Youngest Tertiary and Quaternary sediments by glaciotectonic thrust-faulting as well as incision and refill of glacial valleys. Both underground structures have a strong impact on the distribution of freshwater bearing aquifers. An initial hydrogeological model of Föhr was built from borehole data alone and was restricted to the southern part of the island where in the sandy areas of the Geest a large freshwater body was formed. We improved the geological/hydrogeological model by adding data from different geophysical methods, e.g. airborne electromagnetics (EM for mapping the resistivity of the entire island, seismic reflections for detailed cross sections in the groundwater catchment area, and geophysical borehole logging for calibration of these measurements. An integrated evaluation of the results from the different geophysical methods yields reliable data.

    To determinate petrophysical parameter about 18 borehole logs, more than 75 m deep, and nearby airborne EM inversion models were analyzed concerning resistivity. We establish an empirical relation between measured resistivity and hydraulic conductivity for the specific area – the North Sea island of Föhr. Five boreholes concerning seismic interval velocities discriminate sand and till.

    The interpretation of these data was the basis for building the geological

  4. Silicon oxide barrier films deposited on PET foils in pulsed plasmas: influence of substrate bias on deposition process and film properties

    Science.gov (United States)

    Steves, S.; Ozkaya, B.; Liu, C.-N.; Ozcan, O.; Bibinov, N.; Grundmeier, G.; Awakowicz, P.

    2013-02-01

    A widely used plastic for packaging, polyethylene terephtalate (PET) offers limited barrier properties against gas permeation. For many applications of PET (from food packaging to micro electronics) improved barrier properties are essential. A silicon oxide barrier coating of PET foils is applied by means of a pulsed microwave driven low-pressure plasma. While the adjustment of the microwave power allows for a control of the ion production during the plasma pulse, a substrate bias controls the energy of ions impinging on the substrate. Detailed analysis of deposited films applying oxygen permeation measurements, x-ray photoelectron spectroscopy and atomic force microscopy are correlated with results from plasma diagnostics describing the deposition process. The influence of a change in process parameters such as gas mixture and substrate bias on the gas temperature, electron density, mean electron energy, ion energy and the atomic oxygen density is studied. An additional substrate bias results in an increase in atomic oxygen density up to a factor of 6, although plasma parameter such as electron density of ne = 3.8 ± 0.8 × 1017 m-3 and electron temperature of kBTe = 1.7 ± 0.1 eV are unmodified. It is shown that atomic oxygen densities measured during deposition process higher than nO = 1.8 × 1021 m-3 yield in barrier films with a barrier improvement factor up to 150. Good barrier films are highly cross-linked and show a smooth morphology.

  5. Silicon oxide barrier films deposited on PET foils in pulsed plasmas: influence of substrate bias on deposition process and film properties

    International Nuclear Information System (INIS)

    A widely used plastic for packaging, polyethylene terephtalate (PET) offers limited barrier properties against gas permeation. For many applications of PET (from food packaging to micro electronics) improved barrier properties are essential. A silicon oxide barrier coating of PET foils is applied by means of a pulsed microwave driven low-pressure plasma. While the adjustment of the microwave power allows for a control of the ion production during the plasma pulse, a substrate bias controls the energy of ions impinging on the substrate. Detailed analysis of deposited films applying oxygen permeation measurements, x-ray photoelectron spectroscopy and atomic force microscopy are correlated with results from plasma diagnostics describing the deposition process. The influence of a change in process parameters such as gas mixture and substrate bias on the gas temperature, electron density, mean electron energy, ion energy and the atomic oxygen density is studied. An additional substrate bias results in an increase in atomic oxygen density up to a factor of 6, although plasma parameter such as electron density of ne = 3.8 ± 0.8 × 1017 m−3 and electron temperature of kBTe = 1.7 ± 0.1 eV are unmodified. It is shown that atomic oxygen densities measured during deposition process higher than nO = 1.8 × 1021 m−3 yield in barrier films with a barrier improvement factor up to 150. Good barrier films are highly cross-linked and show a smooth morphology. (paper)

  6. The role of oxygen in the deposition of copper–calcium thin film as diffusion barrier for copper metallization

    International Nuclear Information System (INIS)

    Highlights: • The CuCa film as the diffusion barrier of Cu film improves the adhesion of Cu film. • The introduction of oxygen into the deposition of CuCa film is necessary to improve the adhesion of Cu film. • The CuCa alloy barrier layer deposited at oxygen atmosphere has perfect anti-diffusion between Cu film and substrate. - Abstract: The properties of copper (Cu) metallization based on copper–calcium (CuCa) diffusion barrier as a function of oxygen flux in the CuCa film deposition were investigated in view of adhesion, diffusion and electronic properties. The CuCa film as the diffusion barrier of Cu film improves the adhesion of Cu film, however, and increases the resistance of Cu film. The introduction of oxygen into the deposition of CuCa film induces the improvement of adhesion and crystallinity of Cu film, but produces a slight increase of resistance. The increased resistance results from the partial oxidation of Cu film. The annealing process in vacuum further improves the adhesion, crystallinity and conductivity of Cu film. X-ray diffraction (XRD) and Auger electron spectroscopy (AES) show that the CuCa alloy barrier layer deposited at oxygen atmosphere has perfect anti-diffusion between Cu film and substrate due to the formation of Ca oxide in the interface of CuCa/substrate

  7. Chronostratigraphy of uplifted Quaternary hemipelagic deposits from the Dodecanese island of Rhodes (Greece)

    Science.gov (United States)

    Quillévéré, Frédéric; Cornée, Jean-Jacques; Moissette, Pierre; López-Otálvaro, Gatsby Emperatriz; van Baak, Christiaan; Münch, Philippe; Melinte-Dobrinescu, Mihaela Carmen; Krijgsman, Wout

    2016-07-01

    An integrated magneto-biostratigraphic study, based on calcareous nannofossils and foraminifers, together with the radiometric dating of a volcaniclastic layer found in several outcrops, was carried out on the hemipelagic deposits of the Lindos Bay Formation (LBF) at six localities on the island of Rhodes (Greece). Our highly refined chronostratigraphic framework indicates that the lower and upper lithostratigraphic boundaries of the LBF are diachronous. Associated with the 40Ar/39Ar age determination of 1.85 ± 0.08 Ma for the volcaniclastic layer, our data show that among the investigated outcrops, the Lindos Bay type locality section provides the longest record (1.1 Ma) of the LBF. Hemipelagic deposition occurred continuously from the late Gelasian (∼1.9 Ma) to the late Calabrian (∼0.8 Ma), i.e., from Chrons C2n (Olduvai) to C1r.1r (Matuyama) and from nannofossil Zones CNPL7 to CNPL10. This long record, together with the hemipelagic nature of the deposits, make the Lindos Bay type locality section a unique element in the eastern Mediterranean region, allowing future comparisons with other early Quaternary deep-sea sections available in the central and western Mediterranean regions.

  8. The Effect of the Great Barrier Reef on the Propagation of the 2007 Solomon Islands Tsunami Recorded in Northeastern Australia

    Science.gov (United States)

    Baba, Toshitaka; Mleczko, Richard; Burbidge, David; Cummins, Phil R.; Thio, Hong Kie

    2008-12-01

    The effect of offshore coral reefs on the impact from a tsunami remains controversial. For example, field surveys after the 2004 Indian Ocean tsunami indicate that the energy of the tsunami was reduced by natural coral reef barriers in Sri Lanka, but there was no indication that coral reefs off Banda Aceh, Indonesia had any effect on the tsunami. In this paper, we investigate whether the Great Barrier Reef (GBR) offshore Queensland, Australia, may have weakened the tsunami impact from the 2007 Solomon Islands earthquake. The fault slip distribution of the 2007 Solomon Islands earthquake was firstly obtained by teleseismic inversion. The tsunami was then propagated to shallow water just offshore the coast by solving the linear shallow water equations using a staggered grid finite-difference method. We used a relatively high resolution (approximately 250 m) bathymetric grid for the region just off the coast containing the reef. The tsunami waveforms recorded at tide gauge stations along the Australian coast were then compared to the results from the tsunami simulation when using both the realistic 250 m resolution bathymetry and with two grids having fictitious bathymetry: One in which the the GBR has been replaced by a smooth interpolation from depths outside the GBR to the coast (the “No GBR” grid), and one in which the GBR has been replaced by a flat plane at a depth equal to the mean water depth of the GBR (the “Average GBR” grid). From the comparison between the synthetic waveforms both with and without the Great Barrier Reef, we found that the Great Barrier Reef significantly weakened the tsunami impact. According to our model, the coral reefs delayed the tsunami arrival time by 5-10 minutes, decreased the amplitude of the first tsunami pulse to half or less, and lengthened the period of the tsunami.

  9. Global and local planarization of surface roughness by chemical vapor deposition of organosilicon polymer for barrier applications

    Energy Technology Data Exchange (ETDEWEB)

    Coclite, Anna Maria; Gleason, Karen K. [Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2012-04-01

    Particulates and asperities on the surface of plastic substrates limit the performance of the current protective barrier coatings for flexible electronics. By applying a smoothing layer to the substrate, prior to barrier deposition, permeation is reduced. While application of smoothing layers from the liquid-phase application and curing of acrylate monomers is well known, reports of planarization achieved by vapor deposition are quite limited. In the current work, the chemical vapor deposition (CVD) of a flexible smoothing layer, requiring no curing, is implemented in the same reactor chamber and from the same organosilicon monomer used for depositing the multilayer barrier stack. The process similarity between the smoothing and barrier layer deposition steps has the potential to lower the overall cost of the process and to improve interfacial properties, such as adhesion between the smoothing layer and the barrier stack. The current methods adapts and combines features of two well established methods for CVD of organic layers, plasma enhancement (PECVD) and the specific use of an initiator species (iCVD). The novel, initiated plasma enhanced chemical vapor deposition (iPECVD) method achieves a far greater degree of planarization of flexible organic layer than either of its predecessors. Polystyrene microspheres serve as model defects and allow the degree of planarization to be quantitatively measured. Both cross-sectional scanning electron micrographs and atomic force micrographs demonstrate that when the iPECVD organic layer is 1.8 {mu}m thick, the degree of global planarization is 99%. A model demonstrates that the planarization is achieved as a result of the coating viscosity and the surface tension. Finally, the water vapor barrier performance of a 20-nm-thick SiO{sub x} layer is two orders of magnitude improved when it is deposited on a planarized substrate.

  10. Island shape and electronic structure in diindenoperylene thin films deposited on Au(110) single crystals.

    Science.gov (United States)

    Ciccullo, Francesca; Savu, Sabine A; Glaser, Mathias; Rocco, Maria Luiza M; Chassé, Thomas; Casu, M Benedetta

    2016-05-11

    We have investigated diindenoperylene (DIP) thin films deposited on Au(110) single crystals, by using a multi-technique approach based on X-ray photoemission spectroscopy (XPS), resonant photoemission spectroscopy (RPES), near edge X-ray absorption fine structure (NEXAFS) spectroscopy, atomic force microscopy (AFM) and photoemission electron microscopy (PEEM). DIP molecules are physisorbed on gold, with image-charge screening playing the major role as an interface phenomenon. DIP thin films show Stranski-Krastanov growth mode and the structural herringbone arrangement mimics the arrangement found in DIP single crystals. These results are common with the (100) and (111) gold substrate geometries. On the contrary, the island aggregation is substrate geometry-dependent. This paves the way to exploit the degree of anisotropy in different lattice geometries as a tool for molecular patterning of inorganic surfaces, keeping the electronic structure preserved. PMID:27140434

  11. Accelerated relative sea-level rise and rapid coastal erosion: Testing a causal relationship for the Louisiana barrier islands

    Science.gov (United States)

    List, J.H.; Sallenger, A.H., Jr.; Hansen, M.E.; Jaffe, B.E.

    1997-01-01

    The role of relative sea-level rise as a cause for the rapid erosion of Louisiana's barrier island coast is investigated through a numerical implementation of a modified Bruun rule that accounts for the low percentage of sand-sized sediment in the eroding Louisiana shoreface. Shore-normal profiles from 150 km of coastline west of the Mississippi delta are derived from bathymetric surveys conducted during the 1880s. 1930s and 1980s. An RMS difference criterion is employed to test whether an equilibrium profile form is maintained between survey years. Only about half the studied profiles meet the equilibrium Criterion this represents a significant limitation on the potential applicability of the Bruun rule. The profiles meeting the equilibrium criterion, along with measured rates of relative sea-level rise, are used to hindcast shoreline retreat rates at 37 locations within the study area. Modeled and observed shoreline retreat rates show no significant correlation. Thus in terms of the Bruun approach relative sea-level rise has no power for hindcasting (and presumably forecasting) rates of coastal erosion for the Louisiana barrier islands.

  12. High Prevalence of Porocephalus crotali Infection on a Barrier Island (Cumberland Island) off the Coast of Georgia, with Identification of Novel Intermediate Hosts.

    Science.gov (United States)

    Yabsley, Michael J; Ellis, Angela E; Cleveland, Christopher A; Ruckdeschel, Carol

    2015-10-01

    Porocephalus crotali is a pentastomid parasite that uses crotaline snakes as definitive hosts and a variety of rodents as intermediate hosts. A study of definitive and intermediate pentastome hosts on Cumberland Island, Georgia, revealed high prevalence of P. crotali infection in crotalid snakes as well as several mammalian species. Despite the presence of numerous nymphs in some animals, clinical signs of disease were not observed. In intermediate hosts, the liver, mesentery, and reproductive organs were most commonly infected. No gross evidence of tissue damage was noted in association with the numerous encysted nymphal pentastomes, and histopathology demonstrated minimal reaction to the encysted nymphs. Partial 18S rRNA gene sequences confirmed the parasites were P. crotali. In contrast to many previous reports in rodents, the prevalence on this barrier island was high, and this is the first report of Virginia opossums (Didelphis virginiana) and any insectivore species as intermediate hosts. Although generally not considered pathogenic, the long-term consequences of high nymph intensities on individuals deserve attention. PMID:26042344

  13. Enhancement of barrier properties of aluminum oxide layer by optimization of plasma-enhanced atomic layer deposition process

    International Nuclear Information System (INIS)

    Aluminum oxide (AlxOy) layers were deposited on polyethylene naphthalate substrates by low frequency plasma-enhanced atomic layer deposition process for barrier property enhancement. Trimethylaluminum and oxygen plasma were used as precursor and reactant materials, respectively. In order to enhance the barrier properties several process parameters were examined such as plasma power, working pressure and electrode–substrate distance. Increase of plasma power enhanced the reactivity of activated atomic and molecular oxygen to reduce the carbon contents in AlxOy layer, which appeared to enhance the barrier properties. But too high power caused generation of byproducts which were reincorporated in AlxOy layer to reduce the barrier properties. Plasma generated at lower working pressure was provided with an additional energy for reactions and had more diffusion of the plasma. The O/Al ratio of the layer approached the stoichiometric value by increasing the electrode–substrate distance. At the following conditions: 300 W of plasma power, 26.7 Pa of working pressure and 50 mm of electrode–substrate distance, water vapor transmission rates of the AlxOy layer reached 8.85 × 10−4 g/m2 day. - Highlights: • Aluminum oxide layer was well formed by plasma enhanced atomic layer deposition. • Process parameters were optimized to enhance the barrier properties. • Barrier coating of plastic substrate can be applied to flexible display devices

  14. Fabrication of Nanosized Lanthanum Zirconate Powder and Deposition of Thermal Barrier Coating by Plasma Spray Process

    Science.gov (United States)

    Mishra, S. K.; Jagdeesh, N.; Pathak, L. C.

    2016-07-01

    The present manuscript discusses our findings on fabrication of nanosized lanthanum zirconate powder for thermal barrier coating application and its coating by plasma spray on nickel-based superalloy substrate. Single-phase La2Zr2O7 coating of thickness of the order of 45 µm on the Ni-Cr-Al bond coat coated Ni-based superalloy substrate was deposited by plasma spray process. The layers at the interface did not show spallation and inter diffusion was very less. The microstructure, interface, porosity, and mechanical properties of different layers are investigated. The lanthanum zirconate hardness and modulus were 10.5 and 277 GPa, respectively. The load depth curve for lanthanum zirconate showed good elastic recovery around 74%.

  15. Fabrication of Nanosized Lanthanum Zirconate Powder and Deposition of Thermal Barrier Coating by Plasma Spray Process

    Science.gov (United States)

    Mishra, S. K.; Jagdeesh, N.; Pathak, L. C.

    2016-05-01

    The present manuscript discusses our findings on fabrication of nanosized lanthanum zirconate powder for thermal barrier coating application and its coating by plasma spray on nickel-based superalloy substrate. Single-phase La2Zr2O7 coating of thickness of the order of 45 µm on the Ni-Cr-Al bond coat coated Ni-based superalloy substrate was deposited by plasma spray process. The layers at the interface did not show spallation and inter diffusion was very less. The microstructure, interface, porosity, and mechanical properties of different layers are investigated. The lanthanum zirconate hardness and modulus were 10.5 and 277 GPa, respectively. The load depth curve for lanthanum zirconate showed good elastic recovery around 74%.

  16. Spatial and temporal composition of the avifauna from the barrier islands of the San Ignacio-Navachiste-Macapule lagoon complex, Sinaloa, Mexico

    OpenAIRE

    G Sánchez-Bon; Fernández, G; D Escobedo-Urías; J Torres-Torner; JA Cid-Becerra

    2010-01-01

    We analyzed the composition and abundance of the avifuana inhabiting the barrier islands of the San Ignacio-Navachiste-Macapule lagoon system from July 2006 to June 2007. Species richness and relative abundance were determined for the whole complex and for each island. The cumulative abundance was 55,849 individuals belonging to 71 species, 54 genera, and 26 families, distributed as follows: 51% resident species, 5% summer migratory species, 41% winter migratory species, and 3% transient spec...

  17. LITTER DEPOSITION AND DECOMPOSITION IN THREE FOREST FRAGMENTS PERIODICALLY FLOODABLE IN THE ISLAND OF MARAMBAIA, RJ

    Directory of Open Access Journals (Sweden)

    Ranieri Ribeiro Paula

    2009-09-01

    Full Text Available The litter production and decomposition of three sandy coastal plain forest formations periodically floodable in the Island of Marambaia, Mangaratiba, RJ, were studied from October 2005 to September 2006. For the litter deposition evaluation, 10 litter traps were installed and in each forest formation to quantify the litter decomposition 15 litter bags were allocated in each area. The annual litter production was 11.3, 10.8 and 11.1 Mg ha-1year-1, to F1, F2 and F3, respectively, the highest deposition was verified in the rainy season. To nutrients devolution, the highest value was observed to N, 130.8 kg ha-1 year-1 in F3. The fraction leaves were of higher contribution in relation to the others in all areas. The litter decomposition, evaluated by constant of decomposition (k and half time life was 0.0032 g g-1and 217 days (F2, 0.0031 g g-1and 227 days (F3 and 0.0028 g g-1 and 247 days (F1.

  18. PALEOBATHYMETRIC INTERPRETATION OF THE FISH OTOLITHS FROM THE LOWER - MIDDLE QUATERNARY DEPOSITS OF KEPHALLONIA AND ZAKYNTHOS ISLANDS (IONIAN SEA, WESTERN GREECE)

    OpenAIRE

    KONSTANTINA AGIADI; MARIA TRIANTAPHYLLOU; ANGELA GIRONE; VASSILIS KARAKITSIOS; MICHAEL DERMITZAKIS

    2010-01-01

    Fish otoliths are herein used to estimate the depositional depth of the Early - Middle Pleistocene deposits at SE Zakynthos and SW Kephallonia Islands (Ionian Sea, Western Greece), through comparison with the modern bathymetric distributions of the identified fish taxa. These estimates provide a more detailed picture of the depth variations for the Gelasian - Ionian stage interval in the study areas. The Lower Pleistocene marine deposits of the Gerakas Formation (SE Zakynthos Island, Ionian S...

  19. Dust Deposition and Migration of the ITCZ through the Last Glacial Cycle in the Central Equatorial Pacific (Line Islands).

    Science.gov (United States)

    Reimi Sipala, M. A.; Marcantonio, F.

    2014-12-01

    Atmospheric dust can be used to record climate change in addition to itself playing a role in several key climate processes, such as affecting Earth's albedo, fomenting rain coalescence, encouraging biological productivity, and enhancing carbon export though particle sinks. Using deep sea sediments, it is possible to quantify and locate the sources and sinks of atmospheric dust. A key area of research is the shift in the inter-tropical converge zone (ITCZ), a thermally influenced area that shifts according to the northern and southern hemisphere temperature gradient. This ongoing project focuses on the changes of the ITCZ over the Central Equatorial Pacific (CEP) over the past ~25000 years. The research focuses on two cores taken from the Line Islands Ridge at 0° 29' N (ML1208-18GC), and 4° 41' N (ML1208-31BB). The main aim is to quantify the magnitude and provenance of windblown dust deposited in the CEP, and to address questions regarding the nature of the variations of dust through ice-age climate transitions. Radiogenic isotopes (Sr, Nd, Pb) have been successfully used to distinguish between different potential dust sources in the aluminosilicates fractions of Pacific Sediments. Our preliminary Pb isotope ratios suggest that, for modern deposition, the northern core's (31BB) detrital sediment fraction is likely sourced from Asian Loess (average ratios are 206Pb/204Pb = 18.88, 207Pb/204Pb = 15.69, 208Pb/204Pb = 39.06). The equatorial core's (18GC) detrital fraction has a less radiogenic Pb signature, which is consistent with South American dust sourcing (206Pb/204Pb = 18.62, 207Pb/204Pb = 15.63, 208Pb/204Pb = 38.62). This is indicative of a strong modern ITCZ that acts as an effective barrier for inter-hemispheric dust transport. Prior to Holocene time, the changes in Pb isotope ratios in both cores appear to be in anti-phase; the northern core becomes less radiogenic up to the LGM, while the southern core becomes more radiogenic. This is potentially due to a

  20. Use of a Florida Gulf Coast Barrier Island by Spring Trans-Gulf Migrants and the Projected Effects of Sea Level Rise on Habitat Availability.

    Directory of Open Access Journals (Sweden)

    Lori A Lester

    Full Text Available Barrier islands on the north coast of the Gulf of Mexico are an internationally important coastal resource. Each spring hundreds of thousands of Nearctic-Neotropical songbirds crossing the Gulf of Mexico during spring migration use these islands because they provide the first landfall for individuals following a trans-Gulf migratory route. The effects of climate change, particularly sea level rise, may negatively impact habitat availability for migrants on barrier islands. Our objectives were (1 to confirm the use of St. George Island, Florida by trans-Gulf migrants and (2 to determine whether forested stopover habitat will be available for migrants on St. George Island following sea level rise. We used avian transect data, geographic information systems, remote sensing, and simulation modelling to investigate the potential effects of three different sea level rise scenarios (0.28 m, 0.82 m, and 2 m on habitat availability for trans-Gulf migrants. We found considerable use of the island by spring trans-Gulf migrants. Migrants were most abundant in areas with low elevation, high canopy height, and high coverage of forests and scrub/shrub. A substantial percentage of forest (44% will be lost by 2100 assuming moderate sea level rise (0.82 m. Thus, as sea level rise progresses, less forests will be available for migrants during stopover. Many migratory bird species' populations are declining, and degradation of barrier island stopover habitat may further increase the cost of migration for many individuals. To preserve this coastal resource, conservation and wise management of migratory stopover areas, especially near ecological barriers like the Gulf of Mexico, will be essential as sea levels rise.

  1. Use of a Florida Gulf Coast Barrier Island by Spring Trans-Gulf Migrants and the Projected Effects of Sea Level Rise on Habitat Availability.

    Science.gov (United States)

    Lester, Lori A; Gutierrez Ramirez, Mariamar; Kneidel, Alan H; Heckscher, Christopher M

    2016-01-01

    Barrier islands on the north coast of the Gulf of Mexico are an internationally important coastal resource. Each spring hundreds of thousands of Nearctic-Neotropical songbirds crossing the Gulf of Mexico during spring migration use these islands because they provide the first landfall for individuals following a trans-Gulf migratory route. The effects of climate change, particularly sea level rise, may negatively impact habitat availability for migrants on barrier islands. Our objectives were (1) to confirm the use of St. George Island, Florida by trans-Gulf migrants and (2) to determine whether forested stopover habitat will be available for migrants on St. George Island following sea level rise. We used avian transect data, geographic information systems, remote sensing, and simulation modelling to investigate the potential effects of three different sea level rise scenarios (0.28 m, 0.82 m, and 2 m) on habitat availability for trans-Gulf migrants. We found considerable use of the island by spring trans-Gulf migrants. Migrants were most abundant in areas with low elevation, high canopy height, and high coverage of forests and scrub/shrub. A substantial percentage of forest (44%) will be lost by 2100 assuming moderate sea level rise (0.82 m). Thus, as sea level rise progresses, less forests will be available for migrants during stopover. Many migratory bird species' populations are declining, and degradation of barrier island stopover habitat may further increase the cost of migration for many individuals. To preserve this coastal resource, conservation and wise management of migratory stopover areas, especially near ecological barriers like the Gulf of Mexico, will be essential as sea levels rise. PMID:26934343

  2. Plasma-polymerized SiOx deposition on polymer film surfaces for preparation of oxygen gas barrier polymeric films

    International Nuclear Information System (INIS)

    SiOx films were deposited on surfaces of three polymeric films, PET, PP, and Nylon; and their oxygen gas barrier properties were evaluated. To mitigate discrepancies between the deposited SiOx and polymer film, surface modification of polymer films was done, and how the surface modification could contribute to was discussed from the viewpoint of apparent activation energy for the permeation process. The SiOx deposition on the polymer film surfaces led to a large decrease in the oxygen permeation rate. Modification of polymer film surfaces by mans of the TMOS or Si-COOH coupling treatment in prior to the SiOx deposition was effective in decreasing the oxygen permeation rate. The cavity model is proposed as an oxygen permeation process through the SiOx-deposited Nylon film. From the proposed model, controlling the interface between the deposited SiOx film and the polymer film is emphasized to be a key factor to prepare SiOx-deposited polymer films with good oxygen gas barrier properties. (author)

  3. Telothelepodidae, Thelepodidae and Trichobranchidae (Annelida, Terebelliformia) from Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Hutchings, Pat; de Matos Nogueira, João Miguel; Carrerette, Orlemir

    2015-01-01

    In a survey of the polychaetes of the Lizard Island region, six species of polychaetes belonging to the families Telothelepodidae Nogueira, Fitzhugh & Hutchings, 2013, Thelepodidae Hessle, 1917 and Trichobranchidae Malmgren, 1866 were found, from material collected during the Lizard Island Polychaete Taxonomic Workshop, and material collected by previous projects undertaken by the Australian Museum. This material includes one new species of Rhinothelepus Hutchings, 1974 (Telothelepodidae); one new species of each of the genera, Euthelepus McIntosh, 1885, Streblosoma Sars, 1872, and Thelepus Leuckart, 1849 (Thelepodidae); and one new species of Terebellides Sars, 1835 and another of Trichobranchus Malmgren, 1866 (Trichobranchidae). Keys for identification of these species are provided, together with full descriptions for all species, as well as comparisons with the morphologically most similar congeners. PMID:26624072

  4. Extreme changes to barrier islands along the central Gulf of Mexico coast during Hurricane Katrina: Chapter 5C in Science and the storms-the USGS response to the hurricanes of 2005

    Science.gov (United States)

    Sallenger, Asbury; Wright, Wayne; Lillycrop, Jeff; Howd, Peter; Stockdon, Hilary; Guy, Kristy K.; Morgan, Karen

    2007-01-01

    Hurricane Katrina caused extreme changes to the barrier islands of the central Gulf of Mexico coast. Dauphin Island, Ala., migrated landward and stranded the remains of its oceanfront row homes in the sea. Chandeleur Islands, La., were completely stripped of their sand, leaving only marshy outcrops in the storm's wake.

  5. Comparison of Tillandsia usneoides (Spanish moss) water and leachate dynamics between urban and pristine barrier island maritime oak forests

    Science.gov (United States)

    Van Stan, J. T.; Stubbins, A.; Reichard, J. S.; Wright, K.; Jenkins, R. B.

    2013-12-01

    Epiphyte coverage on forest canopies can drastically alter the volume and chemical composition of rainwater reaching soils. Along subtropical and tropical coastlines Tillandisa usneoides L. (Spanish moss), in particular, can envelop urban and natural tree crowns. Several cities actively manage their 'moss' covered forest to enhance aesthetics in the most active tourist areas (e.g., Savannah GA, St. Augustine FL, Charleston SC). Since T. usneoides survives through atmospheric water and solute exchange from specialized trichomes (scales), we hypothesized that T. usneoides water storage dynamics and leachate chemistry may be altered by exposure to this active urban atmosphere. 30 samples of T. usneoides from managed forests around the tourist center of Savannah, Georgia, USA were collected to compare with 30 samples from the pristine maritime live oak (Quercus virginiana Mill.) forests of a nearby undeveloped barrier island (St. Catherines Island, Georgia, USA). Maximum water storage capacities were determined via submersion (for all 60 samples) along with dissolved ion (DI) and organic matter (DOM) concentrations (for 15 samples each) after simulated throughfall generation using milliQ ultrapurified water. Further, DOM quality was evaluated (for 15 samples each) using absorbance and fluorescence spectroscopy (EEMS). Results show significant alterations to water storage dynamics, DI, DOM, and DOM quality metrics under urban atmospheric conditions, suggesting modified C and water cycling in urban forest canopies that may, in turn, influence intrasystem nutrient cycles in urban catchment soils or streams via runoff.

  6. Diffusion barrier property of MnSixOy layer formed by chemical vapor deposition for Cu advanced interconnect application

    International Nuclear Information System (INIS)

    An amorphous manganese oxide layers formed by chemical vapor deposition have been studied as a copper diffusion barrier. The thermal stability of the barrier layer was assessed by annealing Cu/MnSixOy/SiO2/Si samples at 400 °C for various times up to 10 h. Transmission electron microscopy, energy-dispersive X-ray spectroscopy (EDX), secondary ion mass spectroscopy (SIMS), capacitance-voltage and current–voltage measurements were performed. Failure of the barrier property is marked by observing the copper peak appearing in EDX and SIMS spectra data from the SiO2 region. Amorphous MnSixOy barrier with a thickness of 1.2 nm has failed in preventing Cu diffusion into SiO2 substrate after anneal at 400°C in vacuum for 1h, as proven by the presence of Cu in the dielectric (SiO2) layer. However, the amorphous MnSixOy with the thickness of 2.0 nm barrier was thermally stable and could prevent Cu from inter-diffusion to the SiO2 substrate after annealing at 400 °C even up to 10 h. - Highlights: • Amorphous manganese silicate layer has been studied as a copper diffusion barrier. • The 1.2 nm-thick Mn oxide layer is too thin to become a diffusion barrier. • Good thermal stability of 2.0 nm-thick manganese silicate layer

  7. Palaeoenvironmental dynamics inferred from late Quaternary permafrost deposits on Kurungnakh Island, Lena Delta, Northeast Siberia, Russia

    Science.gov (United States)

    Wetterich, Sebastian; Kuzmina, Svetlana; Andreev, Andrei A.; Kienast, Frank; Meyer, Hanno; Schirrmeister, Lutz; Kuznetsova, Tatyana; Sierralta, Melanie

    2008-08-01

    Late Quaternary palaeoenvironments of the Siberian Arctic were reconstructed by combining data from several fossil bioindicators (pollen, plant macro-fossils, ostracods, insects, and mammal bones) with sedimentological and cryolithological data from permafrost deposits. The record mirrors the environmental history of Beringia and covers glacial/interglacial and stadial/interstadial climate variations with a focus on the Middle Weichselian interstadial (50-32 kyr BP). The late Pleistocene to Holocene sequence on Kurungnakh Island reflects the development of periglacial landscapes under changing sedimentation regimes which were meandering fluvial during the Early Weichselian, colluvial or proluvial on gently inclined plaines during the Middle and Late Weichselian, and thermokarst-affected during the Holocene. Palaeoecological records indicate the existence of tundra-steppe vegetation under cold continental climate conditions during the Middle Weichselian interstadial. Due to sedimentation gaps in the sequence between 32 and 17 kyr BP and 17 and 8 kyr BP, the Late Weichselian stadial is incompletely represented in the studied outcrops. Nevertheless, by several palaeoecological indications arctic tundra-steppe vegetation under extremely cold-arid conditions prevailed during the late Pleistocene. The tundra-steppe disappeared completely due to lasting paludification during the Holocene. Initially subarctic shrub tundra formed, which later retreated in course of the late Holocene cooling.

  8. Effect of Al 2 O 3 Recombination Barrier Layers Deposited by Atomic Layer Deposition in Solid-State CdS Quantum Dot-Sensitized Solar Cells

    KAUST Repository

    Roelofs, Katherine E.

    2013-03-21

    Despite the promise of quantum dots (QDs) as a light-absorbing material to replace the dye in dye-sensitized solar cells, quantum dot-sensitized solar cell (QDSSC) efficiencies remain low, due in part to high rates of recombination. In this article, we demonstrate that ultrathin recombination barrier layers of Al2O3 deposited by atomic layer deposition can improve the performance of cadmium sulfide (CdS) quantum dot-sensitized solar cells with spiro-OMeTAD as the solid-state hole transport material. We explored depositing the Al2O3 barrier layers either before or after the QDs, resulting in TiO2/Al2O3/QD and TiO 2/QD/Al2O3 configurations. The effects of barrier layer configuration and thickness were tracked through current-voltage measurements of device performance and transient photovoltage measurements of electron lifetimes. The Al2O3 layers were found to suppress dark current and increase electron lifetimes with increasing Al 2O3 thickness in both configurations. For thin barrier layers, gains in open-circuit voltage and concomitant increases in efficiency were observed, although at greater thicknesses, losses in photocurrent caused net decreases in efficiency. A close comparison of the electron lifetimes in TiO2 in the TiO2/Al2O3/QD and TiO2/QD/Al2O3 configurations suggests that electron transfer from TiO2 to spiro-OMeTAD is a major source of recombination in ss-QDSSCs, though recombination of TiO2 electrons with oxidized QDs can also limit electron lifetimes, particularly if the regeneration of oxidized QDs is hindered by a too-thick coating of the barrier layer. © 2013 American Chemical Society.

  9. Low temperature deposition of tantalum diffusion barrier by filtered cathodic vacuum arc

    International Nuclear Information System (INIS)

    Tantalum (Ta) diffusion barrier films were deposited on un-patterned and patterned silicon substrates at ambient temperature and without substrate bias by filtered cathodic vacuum arc (FCVA). The films were characterized by atomic force microscopy, scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, four-point resistivity probe and surface profilometer. It was found that the Ta film was 750 A thick and free of C and O except for surface contamination. The film morphology was smooth and uniform with root-mean-square roughness of ∼0.82 A. The Ta film was polycrystalline β phase with a mean grain size of ∼3 nm and possessed a dense microstructure, which are ascribed to the high energy of the condensing species in FCVA. It was shown that the Ta filling of the trenches (0.33 μm wide, 1 : 1 aspect ratio) was very conformal and quite uniform. Also, it was preliminarily found that at the Ta film was effective against diffusion of Cu into Si at 600 deg. C

  10. Nanostructure deposition in the afterglow of a low power barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Sonnenfeld, Axel; Papageorgiou, Vasileios; Reichen, Patrick; Koerner, Lutz; Von Rohr, Philipp Rudolf, E-mail: sonnenfeld@ipe.mavt.ethz.ch, E-mail: vonrohr@ipe.mavt.ethz.ch [ETH Zurich, Institute of Process Engineering, Sonneggstrasse 3, 8092 Zurich (Switzerland)

    2011-02-23

    The precipitation of solid-state sphere-like nanostructures from an organosilicon precursor at atmospheric pressure is investigated with the prospect of improving powder flowability by the attachment of nanoscopic spacers to the powder particles' surfaces. Tetramethylsilane (TMS) is admixed to the afterglow of a low power (<0.5 W) barrier discharge (BD). The BD occurs in a single miniature flow channel, where Ar or He enriched with O{sub 2} is excited favouring homogeneous gas phase reactions of atomic oxygen and TMS in the afterglow. The chemical and morphological influence of Ar or He on the formation of nanostructures is explored at two positions in the afterglow by Fourier transform infrared spectroscopy and scanning electron microscopy. For the Ar-based BD, larger spherical nanostructures (100-1000 nm) of higher oxide content are obtained, while for He polymeric deposits with characteristic sizes below 100 nm are found. In addition, the processing capability of a BD device, consisting of a set of 64 miniature flow channels, is probed by means of the wettability improvement of polymer powder particles, conveyed through the BD afterglow zone of a multi-channel device. The treatment is shown to decrease the benzyl alcohol contact angle significantly with increasing oxygen feed.

  11. In-situ inspection of cracking in atomic-layer-deposited barrier films on surface and in buried structures

    International Nuclear Information System (INIS)

    Thin inorganic barrier films deposited on plastics are essential to provide protection from moisture- and oxygen-aided degradation while maintaining a flexible substrate. Mechanical bending of the barrier films, causes stress-induced cracks that may lead to significant reduction or loss of barrier protection. In-situ characterization of film cracking on the nanoscale, transparent, and conformal atomic-layer-deposited (ALD) thin films is challenging especially when these films are in a buried layer structure. We developed a technique that can inspect in real-time the cracking of the stressed barrier films using laser scanning confocal microscopy. The in-situ inspection avoids the inaccurate measurement of the crack onset strain associated with the crack 'close-up' phenomenon. SU8 cover-coat is applied to form a buried ALD layer structure and in-situ inspection demonstrates the cracking of the ALD film in real-time underneath the cover-coat. This technique is nondestructive, versatile, and allows rapid and large-area inspection of different types of barrier films.

  12. Hydrogen concentration of co-deposited carbon films produced in the vicinity of local island divertor in Large Helical Device

    International Nuclear Information System (INIS)

    It is quite important to evaluate hydrogen concentration of co-deposited carbon film/dust to estimate in-vessel tritium inventory in ITER. The co-deposited carbon films were prepared at the wall of pumping duct in Local Island Divertor experiments of LHD. The hydrogen concentration of the co-deposited carbon film at the wall not facing to the plasma with a low temperature was extremely high, 1.3 in the atomic ratio of H/C. This value is triple times higher than the previous value obtained by hydrogen ion irradiation to graphite. The crystal structure of the co-deposited carbon film observed by Raman spectroscopy showed very unique structure (polymeric a-C:H), which is well consistent with the high hydrogen concentration. The accumulation of in-vessel tritium inventory is also discussed. (author)

  13. LITTER DEPOSITION AND DECOMPOSITION IN A FRAGMENT OF ATLANTIC FOREST IN THE ISLAND OF MARAMBAIA, MANGARATIBA, RJ, BRAZIL

    OpenAIRE

    Marcos Gervasio Pereira; Luis Fernando Tavares de Menezes; Nivaldo Schultz

    2009-01-01

    Litter production and decomposition of an Atlantic Forest fragment in Marambaia Island, Mangaratiba, RJ, were monitored from December 2003 to November 2004. For the litter deposition evaluation, 30 litter traps were installed and 36 litter bags were allocated in the area to quantify litter decomposition. Soil samples were collected at 0-5 cm, 5-10 cm and 10-20 cm depth to evaluate soil fertility. The litter production was 7.9 Mg ha-1 and the highest deposition was verified in November and th...

  14. Barrier performance optimization of atomic layer deposited diffusion barriers for organic light emitting diodes using x-ray reflectivity investigations

    International Nuclear Information System (INIS)

    The importance of O3 pulse duration for encapsulation of organic light emitting diodes (OLEDs) with ultra thin inorganic atomic layer deposited Al2O3 layers is demonstrated for deposition temperatures of 50 °C. X-ray reflectivity (XRR) measurements show that O3 pulse durations longer than 15 s produce dense and thin Al2O3 layers. Correspondingly, black spot growth is not observed in OLEDs encapsulated with such layers during 91 days of aging under ambient conditions. This implies that XRR can be used as a tool for process optimization of OLED encapsulation layers leading to devices with long lifetimes

  15. Properties of plasma-enhanced atomic layer deposited TiCx films as a diffusion barrier for Cu metallization

    International Nuclear Information System (INIS)

    TiCx films were grown on thermally grown SiO2 substrate by atomic layer deposition (ALD) using tetrakis–neopentyl–titanium [Ti(CH2C(CH3)3)4, TiNp4, Np = neopentyl, CH2C(CH3)3] and direct plasma of H2 as a reactant at the substrate temperature ranging from 200 to 400 °C. A narrow ALD temperature window from 275 to 300 °C was shown and a growth rate of 0.054 nm/cycle at the ALD temperature window was obtained. The ALD-TiCx films formed nanocrystalline structure with rock-salt phase that was confirmed by X-ray diffractometry and transmission electronic microscopy (TEM) analysis. Its resistivity was dependent on the microstructure features characterized by grain size and crystallinity as well as its density, which could be controlled by varying the deposition temperature. Resistivity of ~ 600 μΩ cm was obtained at the deposition temperature 300 °C where is in the ALD temperature window, by optimizing deposition condition. In this study, a performance of very thin ALD-TiCx (6 nm) as a diffusion barrier for Cu interconnects was evaluated. The results showed that the structure of Cu (80 nm)/ALD-TiCx (6 nm)/Si was stable after annealing at 600 °C for 30 min. Cross-sectional view TEM analysis combined with energy-dispersive spectroscopy revealed that ALD-TiCx diffusion barrier failed by the diffusion of Cu through the thin barrier layer into Si at 650 °C without interfacial reactions between the layers. - Highlights: • Atomic layer deposition (ALD) of TiCx using a metallorganic precursor. • The growth rate of 0.054 nm/cycle. • ALD temperature window between 275 and 300 °C. • Evaluation as a diffusion barrier against Cu

  16. New data on Upper Carboniferous–Lower Permian deposits of Bol'shevik Island, Severnaya Zemlya Archipelago

    Directory of Open Access Journals (Sweden)

    Victoria B. Ershova

    2015-05-01

    Full Text Available We present here a detailed study of the Upper Carboniferous–Lower Permian stratigraphy of Bol'shevik Island in the Severnaya Zemlya Archipelago, consisting of the analysis of sedimentary structures and lithostratigraphy, U/Pb detrital zircon dating and structural studies. The preserved sedimentary structures suggest that the studied strata were deposited in a relatively small meandering fluvial system. U/Pb dating of detrital zircons reveals that the Upper Carboniferous–Lower Permian sandstones contain a primary age population ranging from 450 to 570 millions of years, with a predominance of Early–Middle Ordovician zircons. This detrital zircon distribution indicates that the studied formations were derived locally from the erosion of Lower Ordovician deposits of Bol'shevik Island or elsewhere in the archipelago. Our structural studies suggest that Upper Carboniferous–Lower Permian deposits are deformed into a series of west–north-west verging open asymmetric folds, suggesting a west–north-west direction of tectonic transport and that deformation across the island is post-Early Permian in age.

  17. Thin film deposition at atmospheric pressure using dielectric barrier discharges: Advances on three-dimensional porous substrates and functional coatings

    Science.gov (United States)

    Fanelli, Fiorenza; Bosso, Piera; Mastrangelo, Anna Maria; Fracassi, Francesco

    2016-07-01

    Surface processing of materials by atmospheric pressure dielectric barrier discharges (DBDs) has experienced significant growth in recent years. Considerable research efforts have been directed for instance to develop a large variety of processes which exploit different DBD electrode geometries for the direct and remote deposition of thin films from precursors in gas, vapor and aerosol form. This article briefly reviews our recent progress in thin film deposition by DBDs with particular focus on process optimization. The following examples are provided: (i) the plasma-enhanced chemical vapor deposition of thin films on an open-cell foam accomplished by igniting the DBD throughout the entire three-dimensional (3D) porous structure of the substrate, (ii) the preparation of hybrid organic/inorganic nanocomposite coatings using an aerosol-assisted process, (iii) the DBD jet deposition of coatings containing carboxylic acid groups and the improvement of their chemical and morphological stability upon immersion in water.

  18. Stability of 8-hydroxyquinoline aluminum films encapsulated by a single Al{sub 2}O{sub 3} barrier deposited by low temperature atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Maindron, Tony, E-mail: tony.maindron@cea.fr [CEA-LETI, MINATEC Campus, LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Simon, Jean-Yves; Viasnoff, Emilie [CEA-LETI, MINATEC Campus, LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Lafond, Dominique [CEA-LETI, MINATEC Campus, LETI/DTSI/SCMC/, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France)

    2012-09-30

    100 nm thick 8-AlQ{sub 3} films deposited onto silicon wafers have been encapsulated by mean of low temperature atomic layer deposition of Al{sub 2}O{sub 3} (20 nm). Investigation of the film evolution under storage test as harsh as 65 Degree-Sign C/85% RH has been investigated up to {approx} 1000 h and no severe degradation could be noticed. The results have been compared to raw AlQ{sub 3} films which deteriorate far faster in the same conditions. For that purpose, fluorescence measurements and atomic force microscopy have been used to monitor the film evolution while transmission electron microscopy has been used to image the interface between AlQ{sub 3} and Al{sub 2}O{sub 3}. This concept of bilayer AlQ{sub 3}/Al{sub 2}O{sub 3} barrier films has finally been tested as an encapsulation barrier onto an organic light-emitting diode. - Highlights: Black-Right-Pointing-Pointer Thin Al{sub 2}O{sub 3} films have been deposited by atomic layer deposition onto organic films. Black-Right-Pointing-Pointer AlQ{sub 3}/Al{sub 2}O{sub 3}-encapsulated organic light-emitting diodes show long-term stability. Black-Right-Pointing-Pointer Unencapsulated reference AlQ{sub 3} films degrade much faster.

  19. Epitaxial growth of CoSi2 on Si(001) by reactive deposition epitaxy: Island growth and coalescence

    International Nuclear Information System (INIS)

    Epitaxial CoSi2 layers, which are phase pure but contain {111} twins, are grown on Si(001) at 700 deg. C by reactive deposition epitaxy. Transmission electron microscopy analyses show that the initial formation of CoSi2(001) follows the Volmer-Weber mode characterized by the independent nucleation and growth of three-dimensional islands whose evolution we follow as a function of deposited Co thickness t Co in order to understand the origin of the observed twin density. We find that there are two families of island shapes: inverse pyramids and platelets. The rectangular-based pyramidal islands extend along orthogonal directions, bounded by four {111} CoSi2/Si interfaces, and grow with a cube-on-cube orientation with respect to the substrate: (001)CoSi2 parallel (001)Si and [100]CoSi2 parallel [100]Si. Platelet-shaped CoSi2 islands are bounded across their long directions by {111} twin planes (i.e. {111}(001)CoSi2 parallel {111}Si) and their narrow directions by {511}CoSi2 parallel {111}Si interfaces. The top and bottom surfaces are {22-bar1}, with {22-bar1}CoSi2||(001)Si, and {1-bar1-bar1}, with {1-bar1-bar1}CoSi2 parallel {11-bar1}Si, respectively. The early stages of film growth (t Co ≤ 13 A) are dominated by the twinned platelets due to a combination of higher nucleation rates resulting from a larger number of favorable adsorption sites in the Si(001)2 x 1 surface unit cell and rapid elongation of the platelets along preferred directions. However, at t Co ≥ 13 A island coalescence becomes significant as orthogonal platelets intersect and block elongation along fast growth directions. In this regime, where both twinned and untwinned island number densities have saturated, further island growth becomes dominated by the untwinned islands. A continuous epitaxial CoSi2(001) layer, with a twin density of 2.8 x 1010 cm-2, is obtained at t Co = 50 A

  20. Effect of storms on Barrier Island dynamics, Core Banks, Cape Lookout National Seashore, North Carolina, 1960-2001

    Science.gov (United States)

    Riggs, Stanley R.; Ames, Dorothea V.

    2007-01-01

    The effect of storms on long-term dynamics of barrier islands was evaluated on Core Banks, a series of barrier islands that extend from Cape Lookout to Okracoke Inlet in the Cape Lookout National Seashore, North Carolina. Shoreline and elevation changes were determined by comparing 77 profiles and associated reference markers established by the U.S. Army Corps of Engineers (USACE) on Core Banks from June 1960 to July 1962 to a follow-up survey by Godfrey and Godfrey (G&G) in 1971 and a survey by the Department of Geology at East Carolina University (ECU) in 2001, in which 57 of the original 77 profiles were located. Evaluation of the baseline data associated with the USACE study supplies an important record of barrier island response to two specific storm events—Hurricane Donna in September 1960 and the Ash Wednesday extra-tropical cyclone in March 1962. The 1962 USACE survey was followed by 9 years characterized by no major storms; this low-energy period was captured by the G&G survey in 1971. The G&G survey was followed by 22 years characterized by occasional small to moderate storms. Starting in 1993, however, and continuing through 1999, the North Carolina coast experienced a major increase in storm activity, with seven major hurricanes impacting Core Banks. Both the USACE 1960–1962 and G&G 1962–1971 surveys produced short-term data sets that reflected very different sets of weather conditions. The ECU 2001 survey data were then compared with the USACE 1960 survey data to develop a long-term (41 years) data set for shoreline erosion on Core Banks. Those resulting long-term data were compared with the long-term (52 years) data sets by the North Carolina Division of Coastal Management (NCDCM) from 1940–1992 and 1946–1998; a strong positive correlation and very similar rates of average annual erosion resulted. However, the ECU and NCDCM long-term data sets did not correlate with either of the USACE and G&G short-term survey data and had very different

  1. Low temperature synthesis of silicon nitride thin films deposited by VHF/RF PECVD for gas barrier application

    Science.gov (United States)

    Lee, Jun S.; Shin, Kyung S.; Sahu, B. B.; Han, Jeon G.

    2015-09-01

    In this work, silicon nitride (SiNx) thin films were deposited on polyethylene terephthalate (PET) substrates as barrier layers by plasma enhanced chemical vapor deposition (PECVD) system. Utilizing a combination of very high-frequency (VHF 40.68 MHz) and radio-frequency (RF 13.56 MHz) plasmas it was possible to adopt PECVD deposition at low-temperature using the precursors: Hexamethyldisilazane (HMDSN) and nitrogen. To investigate relationship between film properties and plasma properties, plasma diagnostic using optical emission spectroscopy (OES) was performed along with the film analysis using Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). OES measurements show that there is dominance of the excited N2 and N2+ emissions with increase in N2 dilution, which has a significant impact on the film properties. It was seen that all the deposited films contains mainly silicon nitride with a small content of carbon and no signature of oxygen. Interestingly, upon air exposure, films have shown the formation of Si-O bonds in addition to the Si-N bonds. Measurements and analysis reveals that SiNx films deposited with high content of nitrogen with HMDSN plasma can have lower gas barrier properties as low as 7 . 3 ×10-3 g/m2/day. Also at Chiang Mai University.

  2. High-growth rate YSZ thermal barrier coatings deposited by MOCVD demonstrate high thermal cycling lifetime

    International Nuclear Information System (INIS)

    Research highlights: → Use of thermochemical analysis to optimize stoichiometric ratios prior to experiments. → Thermodynamic analysis included a YO1.5-ZrO2 phase diagram to better describe solid solutions of YSZ. → Experimental growth resulted in high growth rate coatings with a columnar microstructure. → Coatings endured 1000 1-h thermal cycles (comparable to the lifetime of commercially viable EBPVD YSZ coating) with a much lower cost of fabrication. - Abstract: Yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBC) were prepared by metalorganic chemical vapor deposition (MOCVD) using Y(OButn)3, Zr(OButn)4 precursors and O2 carrier gas. A thermodynamic analysis guided experiments by optimizing elemental molar (n) stoichiometric ratios for the (Zr-Y-O-C-H system). This analysis showed single-phase YSZ was favored at 950 deg. C, 1 kPa, nO/(nY + nZr) > 30, nY/(nY + nZr) = 0.06-0.10 (fixed nC, nH). Experimental YSZ growth had multiple phases (fcc, monoclinic), had a relatively high growth rate (43 μm/h, 1005 deg. C), had an Arrhenius dependence (845-950 deg. C, Ea = 53.8 ± 7.9 kJ/mol), had columnar grains (SEM analysis), and had a coating through-thickness nY/(nY + nZr) = 0.04 (EPMA analysis). Doubling the inlet yttrium precursor mole fraction resulted in fcc YSZ growth with a coating through-thickness nY/(nY + nZr) = 0.07. Hot-insertion thermal cycling of YSZ coatings on FeCrAlY bond coats showed >1000 h lifetime, matching current standards for EB-PVD YSZ coatings.

  3. Creation of leak-proof silicon carbide diffusion barriers by means of pulsed laser deposition

    Energy Technology Data Exchange (ETDEWEB)

    Reinecke, A.-M.; Lustfeld, M.; Lippmann, W., E-mail: wolfgang.lippmann@tu-dresden.de; Hurtado, A.

    2014-05-01

    TRISO (tristructural isotropic) coated fuel particles are a crucial element of the HTR safety concept. While TRISO coated particles have been proven as a very efficient barrier for a large range of fission products in HTR experimental reactors, some particular fission products could still diffuse at a considerable rate. Most importantly, radioactive silver {sup 110m}Ag was found to be released from coated particles. In future HTRs with active components like a gas turbine in the primary circuit, such silver contamination may severely limit maintainability of these parts with the result of reduced life-time performance. So far, experimental analyses on silver diffusion through silicon carbide have led to contradictory results. In this work, an alternative method was used to generate silicon carbide layers as a basis for analysis of silver diffusion. With pulsed laser deposition (PLD), it is possible to generate coatings of different materials and various kinds of compounds. In particular, this technology allows the generation of layers very well defined with respect to their composition, purity and density. The microstructure can precisely be manipulated through various parameters. Based on different silicon carbide coatings with well-defined properties, we are going to investigate the silver diffusion process. Our goal is to derive the properties of an ideal silicon carbide coating preventing silver diffusion entirely. In this paper we present the major aspects of our work creating crystalline SiC layers as well as silver and CsI layers both on plane and spherical substrates. Analyses with X-ray diffraction, X-ray spectrometry and secondary ion mass spectrometry show that complex multilayer systems comprising a graphite substrate, a crystalline SiC layer and an intermediate silver layer were successfully created. Major challenges to approach in the future are the handling of high-level intrinsic stresses forming in the layer structure as well as the high vapour

  4. Creation of leak-proof silicon carbide diffusion barriers by means of pulsed laser deposition

    International Nuclear Information System (INIS)

    TRISO (tristructural isotropic) coated fuel particles are a crucial element of the HTR safety concept. While TRISO coated particles have been proven as a very efficient barrier for a large range of fission products in HTR experimental reactors, some particular fission products could still diffuse at a considerable rate. Most importantly, radioactive silver 110mAg was found to be released from coated particles. In future HTRs with active components like a gas turbine in the primary circuit, such silver contamination may severely limit maintainability of these parts with the result of reduced life-time performance. So far, experimental analyses on silver diffusion through silicon carbide have led to contradictory results. In this work, an alternative method was used to generate silicon carbide layers as a basis for analysis of silver diffusion. With pulsed laser deposition (PLD), it is possible to generate coatings of different materials and various kinds of compounds. In particular, this technology allows the generation of layers very well defined with respect to their composition, purity and density. The microstructure can precisely be manipulated through various parameters. Based on different silicon carbide coatings with well-defined properties, we are going to investigate the silver diffusion process. Our goal is to derive the properties of an ideal silicon carbide coating preventing silver diffusion entirely. In this paper we present the major aspects of our work creating crystalline SiC layers as well as silver and CsI layers both on plane and spherical substrates. Analyses with X-ray diffraction, X-ray spectrometry and secondary ion mass spectrometry show that complex multilayer systems comprising a graphite substrate, a crystalline SiC layer and an intermediate silver layer were successfully created. Major challenges to approach in the future are the handling of high-level intrinsic stresses forming in the layer structure as well as the high vapour pressure

  5. Shoreline-change Rates of the Barrier Islands in Nakdong River Estuary Using Aerial Photography and SPOT-5 Image

    Directory of Open Access Journals (Sweden)

    Sang-Hun Jeong

    2013-03-01

    Full Text Available Shoreline data of the barrier islands in Nakdong River Estuary for the last three decades wereassembled using six sets of aerial photographs and seven sets of satellite images. Canny Algorithm wasapplied to untreated data in order to obtain a wet-dry boundary as a proxy shoreline. Digital ShorelineAnalysis System (DSAS 4.0 was used to estimate the rate of shoreline changes in terms of five statisticalvariables; SCE (Shoreline Change Envelope, NSM (Net Shoreline Movement, EPR(End Point Rate, LRR(Linear Regression Rate, and LMS (Least Median of Squares. The shoreline in Jinwoodo varieddifferently from one place to another during the last three decades; the west tail has advanced (i.e., seawardor southward, the west part has regressed, the south part has advanced, and the east part has regressed.After the 2000s, the rate of shoreline changes (−2.5~6.7 m/yr increased and the east advanced. Theshoreline in Shinjado shows a counterclockwise movement; the west part has advanced, but the east part hasretreated. Since Shinjado was built in its present form, the west part became stable, but the east part hasregressed faster. The rate of shoreline changes (−16.0~12.0 m/yr in Shinjado is greater than that ofJinwoodo. The shoreline in Doyodeung has advanced at a rate of 31.5 m/yr. Since Doyodeung was built inits present form, the south part has regressed at the rate of −18.2 m/yr, but the east and west parts haveadvanced at the rate of 13.5~14.3 m/yr. Based on Digital Shoreline Analysis, shoreline changes in thebarrier islands in the Nakdong River Estuary have varied both temporally and spatially, although the exactreason for the shoreline changes requires more investigation.

  6. Diel coral reef acidification driven by porewater advection in permeable sands, Heron Island, Great Barrier Reef

    DEFF Research Database (Denmark)

    Santos, Isaac R.; Glud, Ronnie N.; Maher, Damien;

    2011-01-01

    Little is known about how biogeochemical processes in permeable sediments affect the pH of coastal waters. We demonstrate that seawater recirculation in permeable sands can play a major role in proton (H+) cycling in a coral reef lagoon. The diel pH range (up to 0.75 units) in the Heron Island...... lagoon was the broadest ever reported for reef waters, and the night‐time pH (7.69) was comparable to worst‐case scenario predictions for seawater pH in 2100. The net contribution of coarse carbonate sands to the whole system H+ fluxes was only 9% during the day, but approached 100% at night when small...... scale (i.e., flow and topography‐induced pressure gradients) and large scale (i.e., tidal pumping as traced by radon) seawater recirculation processes were synergistic. Reef lagoon sands were a net sink for H+, and the sink strength was a function of porewater flushing rate. Our observations suggest...

  7. Highly variable acquisition rates of Ixodes scapularis (Acari: Ixodidae) by birds on an Atlantic barrier island.

    Science.gov (United States)

    Mitra, S S; Buckley, P A; Buckley, F G; Ginsberg, H S

    2010-11-01

    Acquisition of ticks by bird hosts is a central process in the transmission cycles of many tick-borne zoonoses, but tick recruitment by birds has received little direct study. We documented acquisition of Ixodes scapularis Say on birds at Fire Island, NY, by removing ticks from mist-netted birds, and recording the number of ticks on birds recaptured within 4 d of release. Eight bird species acquired at least 0.8 ticks bird(-1) day(-1) during the seasonal peak for at least one age class of I. scapularis. Gray Catbirds, Eastern Towhees, Common Yellowthroats, and Northern Waterthrushes collectively accounted for 83% of all tick acquisitions; and six individuals apportioned among Black-billed Cuckoo, Gray Catbird, Eastern Towhee, and Common Yellowthroat were simultaneously infested with both larvae and nymphs. Bird species with the highest acquisition rates were generally ground foragers, whereas birds that did not acquire ticks in our samples generally foraged above the ground. Tick acquisition by birds did not differ between deciduous and coniferous forests. Among the 15 bird species with the highest recruitment rates, acquisition of nymphs was not correlated with acquisition of larvae. Tick acquisition rates by individual bird species were not correlated with the reservoir competence of those species for Lyme borreliae. However, birds with high tick acquisition rates can contribute large numbers of infected ticks, and thus help maintain the enzootic cycle, even if their levels of reservoir competence are relatively low. PMID:21175049

  8. A 6000-year palaeo-environmental record from Harataonga, Great Barrier Island, New Zealand

    International Nuclear Information System (INIS)

    A pollen, sediment, and tephra record from a drained swamp at Harataonga contains a history of the local coastal environment from the Mid Holocene. This commences c. 6000 cal yr BP in a freshwater environment with swamp forest composed mainly of Laurelia, Leptospermum, Ascarina, and Cyathea spp. Dodonaea and Cyperaceae grew on margins of this forest. Forest on the hills surrounding the wetland comprised mainly Metrosideros, with emergent Dacrydium and Libocedrus. Ascarina, Rhopalostylis, and Cyathea dealbata type were a significant part of the understorey of this hillside forest. Around the time of deposition of the 5550 cal yr BP Whakatane tephra, a freshwater lake developed at the site. Extensive Cyperaceae swamp developed on the fringes of the lake. Shortly after c. 2900 cal yr BP, Dacrycarpus briefly invaded swamp forest, possibly as a result of storm disturbance, and the site made the final transition to swamp. Myrsine and then Hebe shrubs invaded fringes of the swamp as the water table fell, possibly as a result of a change to drier conditions in the Late Holocene. Polynesian deforestation, as indicated by the presence of abundant charcoal and Pteridium spores, is recorded in this core as occurring shortly after deposition of the c. 600 cal yr BP Kaharoa tephra. (author). 29 refs., 3 figs., 1 tab

  9. Porphyrins as Templates for Site-Selective Atomic Layer Deposition: Vapor Metalation and in Situ Monitoring of Island Growth.

    Science.gov (United States)

    Avila, Jason R; Emery, Jonathan D; Pellin, Michael J; Martinson, Alex B F; Farha, Omar K; Hupp, Joseph T

    2016-08-10

    Examinations of enzymatic catalysts suggest one key to efficient catalytic activity is discrete size metallo clusters. Mimicking enzymatic cluster systems is synthetically challenging because conventional solution methods are prone to aggregation or require capping of the cluster, thereby limiting its catalytic activity. We introduce site-selective atomic layer deposition (ALD) on porphyrins as an alternative approach to grow isolated metal oxide islands that are spatially separated. Surface-bound tetra-acid free base porphyrins (H2TCPP) may be metalated with Mn using conventional ALD precursor exposure to induce homogeneous hydroxide synthetic handles which acts as a nucleation point for subsequent ALD MnO island growth. Analytical fitting of in situ QCM mass uptake reveals island growth to be hemispherical with a convergence radius of 1.74 nm. This growth mode is confirmed with synchrotron grazing-incidence small-angle X-ray scattering (GISAXS) measurements. Finally, we extend this approach to other ALD chemistries to demonstrate the generality of this route to discrete metallo island materials. PMID:27454741

  10. A new gnathiid (Crustacea: Isopoda) parasitizing two species of requiem sharks from Lizard Island, Great Barrier Reef, Australia.

    Science.gov (United States)

    Coetzee, Maryke L; Smit, Nico J; Grutter, Alexandra S; Davies, Angela J

    2008-06-01

    Third-stage juveniles (praniza 3) of Gnathia grandilaris n. sp. were collected from the gill filaments and septa of 5 requiem sharks, including a white tip reef shark, Triaenodon obesus, and 4 grey reef sharks, Carcharhinus amblyrhynchos, at Lizard Island, Great Barrier Reef, Australia, in March 2002. Some juvenile gnathiids were then maintained in fresh sea water until they molted to adults. Adult males appeared 19 days following detachment of juveniles from host fishes, but no juveniles molted successfully into females. The current description is based, therefore, on bright field and scanning electron microscopy observations of adult males and third-stage juveniles. Unique features of the male include the triangular-shaped inferior medio-frontal process, 2 areolae on the dorsal surface of the pylopod, and a slender pleotelson (twice as long as wide) with lateral concavities. The third-stage juvenile has distinctive white pigmentation on the black pereon when alive, while the mandible has 9 triangular backwardly directed teeth. This species has the largest male and third-stage juvenile of any Gnathia spp. from Australia and of any gnathiid isopods associated with elasmobranchs. PMID:18605791

  11. A Bayesian network approach to predicting nest presence of thefederally-threatened piping plover (Charadrius melodus)using barrier island features

    Science.gov (United States)

    Gieder, Katherina D.; Karpanty, Sarah M.; Frasera, James D.; Catlin, Daniel H.; Gutierrez, Benjamin T.; Plant, Nathaniel G.; Turecek, Aaron M.; Thieler, E. Robert

    2014-01-01

    Sea-level rise and human development pose significant threats to shorebirds, particularly for species that utilize barrier island habitat. The piping plover (Charadrius melodus) is a federally-listed shorebird that nests on barrier islands and rapidly responds to changes in its physical environment, making it an excellent species with which to model how shorebird species may respond to habitat change related to sea-level rise and human development. The uncertainty and complexity in predicting sea-level rise, the responses of barrier island habitats to sea-level rise, and the responses of species to sea-level rise and human development necessitate a modelling approach that can link species to the physical habitat features that will be altered by changes in sea level and human development. We used a Bayesian network framework to develop a model that links piping plover nest presence to the physical features of their nesting habitat on a barrier island that is impacted by sea-level rise and human development, using three years of data (1999, 2002, and 2008) from Assateague Island National Seashore in Maryland. Our model performance results showed that we were able to successfully predict nest presence given a wide range of physical conditions within the model’s dataset. We found that model predictions were more successful when the range of physical conditions included in model development was varied rather than when those physical conditions were narrow. We also found that all model predictions had fewer false negatives (nests predicted to be absent when they were actually present in the dataset) than false positives (nests predicted to be present when they were actually absent in the dataset), indicating that our model correctly predicted nest presence better than nest absence. These results indicated that our approach of using a Bayesian network to link specific physical features to nest presence will be useful for modelling impacts of sea-level rise- or human

  12. Origin and palaeo-environmental significance of the Berrazales carbonate spring deposit, North of Gran Canaria Island, Spain

    Science.gov (United States)

    Camuera, Jon; Alonso-Zarza, Ana M.; Rodríguez-Berriguete, Álvaro; Rodriguez-Gonzalez, Alejandro

    2014-07-01

    The Berrazales carbonate spring deposit is a small outcrop constituted mainly by cascade-like geometries. Four main facies have been identified: fibrous dense macrocrystalline formed by rapid degassing under high-flow conditions; framestones of coated plant moulds formed in moderate energy flow favoured by the presence of biogenic support; micrite/microsparite are primary precipitates in which crystalline aggregates nucleated on organic filaments and/or EPS; banded micrite-coarse crystalline were the result of alternating physically, chemically and biologically induced precipitation in areas of varying flow-velocities. Most facies underwent different degrees of micritization processes. Micrite is distributed as thin lines penetrating the crystals, as irregular patches or as micrite layers. In the first case organic filaments penetrate crystals, suggesting that micritization is mainly biogenically driven. In the latter cases micritization is caused mostly by partial dissolution. Microbe participation in micrite formation increased micrite MgCO3 content in comparison with coarse crystalline facies. Isotopic analyses show positive δ13C values (+ 2.63 and + 4.29‰ VPDB) and negative δ18O (- 5.65 and - 4.48‰ VPDB) values. Positive δ13C values clearly indicate "deep-sourced" fluids. The Berrazales spring deposit studied here very probably is a small part of a larger carbonate building that was largely eroded by fluvial incision. Calculations of spring water temperature give a range from 20 °C to 35 °C, characteristic of a cold to warm spring favouring precipitation of calcite and important biogenic activity (framestones). Although the study deposit has textural characteristics of tufas, proving that the CO2 sourced from deep fluids, it should be considered as thermogene travertine, being one more example of the difficulty of using those terms for ancient sedimentary deposits. Carbonate spring deposits, very rare in the Canary Islands, are good archives of recent

  13. Vapor deposition of cross-linked fluoropolymer barrier coatings onto pre-assembled microfluidic devices.

    Science.gov (United States)

    Riche, Carson T; Marin, Brandon C; Malmstadt, Noah; Gupta, Malancha

    2011-09-21

    The interior surfaces of pre-assembled poly(dimethylsiloxane) (PDMS) microfluidic devices were modified with a cross-linked fluoropolymer barrier coating that significantly increased the chemical compatibility of the devices. PMID:21850298

  14. Nano-particle size-dependent charging and electro-deposition in dielectric barrier discharges at atmospheric pressure for thin SiO{sub x} film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Jidenko, N [Equipe Decharges Electriques et Environnement du Laboratoire de Physique des Gaz et des Plasmas, UMR 8578 CNRS - Universite Paris-Sud Orsay, F-91405 Supelec, Plateau Moulon, F-91192 Gif Sur Yvette (France); Jimenez, C [Laboratoire de Genie Electrique de Toulouse, CNRS - Universite Paul Sabatier, Universite Paul Sabatier, 118 route de Narbonne, 31060 Toulouse (France); Massines, F [Laboratoire de Genie Electrique de Toulouse, CNRS - Universite Paul Sabatier, 118 route de Narbonne, 31060 Toulouse (France); Borra, J-P [Equipe Decharges Electriques et Environnement du Laboratoire de Physique des Gaz et des Plasmas, UMR 8578 CNRS - Universite Paris-Sud Orsay, F-91405 Supelec, Plateau Moulon, F-91192 Gif Sur Yvette (France)

    2007-07-21

    This paper focuses on charging and electro-deposition of nano-particles produced in a mixture of silane and nitrous oxide diluted in N{sub 2}, by dielectric barrier discharge (DBD) at atmospheric pressure for SiO{sub x} film deposition. Townsend discharge (TD) and filamentary discharge (FD) are compared with and without SiH{sub 4}. Without SiH{sub 4}, particles are produced by filament-surface interaction. Both filament-surface and plasma-silane interactions lead to bimodal particle size distributions from nucleation and agglomeration. With SiH{sub 4}, particle formation and growth imply the same mechanisms in TD and FD. Faster dynamics in FD are related to higher local volume energy density than in TD. From scanning electron microscope images of the film and measurements downstream of the DBD reactor, the diameter of the particle produced is below 50 nm. An analytical model of electro-collection in an ac electric field is used to investigate nano-particle charging. To account for selective electro-deposition leading to particles smaller than 50 nm being included in the layer and to particle size distribution measured downstream of the DBD, the same size-dependent charging and electro-deposition of particle are involved, with different charging dynamics in TD and FD.

  15. Low-temperature gas-barrier films by atomic layer deposition for encapsulating organic light-emitting diodes

    Science.gov (United States)

    Tseng, Ming-Hung; Yu, Hui-Huan; Chou, Kun-Yi; Jou, Jwo-Huei; Lin, Kung-Liang; Wang, Chin-Chiun; Tsai, Feng-Yu

    2016-07-01

    Dependences of gas-barrier performance on the deposition temperature of atomic-layer-deposited (ALD) Al2O3, HfO2, and ZnO films were studied to establish low-temperature ALD processes for encapsulating organic light-emitting diodes (OLEDs). By identifying and controlling the key factors, i.e. using H2O2 as an oxidant, laminating Al2O3 with HfO2 or ZnO layers into AHO or AZO nanolaminates, and extending purge steps, OLED-acceptable gas-barrier performance (water vapor transmission rates ∼ 10‑6 g m‑2 d‑1) was achieved for the first time at a low deposition temperature of 50 °C in a thermal ALD mode. The compatibility of the low-temperature ALD process with OLEDs was confirmed by applying the process to encapsulate different types of OLED devices, which were degradation-free upon encapsulation and showed adequate lifetime during accelerated aging tests (pixel shrinkage <5% after 240 h at 60 °C/90% RH).

  16. LITTER DEPOSITION AND DECOMPOSITION IN A FRAGMENT OF ATLANTIC FOREST IN THE ISLAND OF MARAMBAIA, MANGARATIBA, RJ, BRAZIL

    Directory of Open Access Journals (Sweden)

    Marcos Gervasio Pereira

    2009-09-01

    Full Text Available Litter production and decomposition of an Atlantic Forest fragment in Marambaia Island, Mangaratiba, RJ, were monitored from December 2003 to November 2004. For the litter deposition evaluation, 30 litter traps were installed and 36 litter bags were allocated in the area to quantify litter decomposition. Soil samples were collected at 0-5 cm, 5-10 cm and 10-20 cm depth to evaluate soil fertility. The litter production was 7.9 Mg ha-1 and the highest deposition was verified in November and the lowest in June. The leaf fraction presented the highest contribution comparing to the others. In seven months of observation, litter decomposition rate was 40% and showed an exponential decrease. Different behavior for N, P and K release was verified. Exception for P, carbon, nutrients and H+Al presented highest concentrations in superficial layer.

  17. Uranium-series ages of corals and coexisting phosphate deposits on Pelsaert Reef Complex, Houtman-Abrolhos Islands, Western Australia

    Science.gov (United States)

    Veeh, H. Herbert; France, Roy E.

    1988-09-01

    An unusually well-defined association between guano-derived phosphate rock (apatite) and coral carbonates on Pelsaert Island has provided an opportunity to test uranium-series dating methods as applied to insular phosphorites. The phosphate deposit, which is bracketed by late Pleistocene and Holocene corals with {230Th}/{234U} ages of 120,000 and 4700 yr B.P., respectively, has {230Th}/{234U} ages ranging from 85,000 to 112,000 yr B.P. The mutually consistent results suggest that phosphate deposition commenced soon after the peak of the last interglaciation and has been largely controlled by sea-level fluctuations and probably other factors associated with late Quaternary climate in this area.

  18. Secondary growth mechanism of SiGe islands deposited on a mixed-phase microcrystalline Si by ion beam co-sputtering

    Science.gov (United States)

    Ke, S. Y.; Yang, J.; Qiu, F.; Wang, Z. Q.; Wang, C.; Yang, Y.

    2015-11-01

    We discuss the SiGe island co-sputtering deposition on a microcrystalline silicon (μc-Si) buffer layer and the secondary island growth based on this pre-SiGe island layer. The growth phenomenon of SiGe islands on crystalline silicon (c-Si) is also investigated for comparison. The pre-SiGe layer grown on μc-Si exhibits a mixed-phase structure, including SiGe islands and amorphous SiGe (a-SiGe) alloy, while the layer deposited on c-Si shows a single-phase island structure. The preferential growth and Ostwald ripening growth are shown to be the secondary growth mechanism of SiGe islands on μc-Si and c-Si, respectively. This difference may result from the effect of amorphous phase Si (AP-Si) in μc-Si on the island growth. In addition, the Si-Ge intermixing behavior of the secondary-grown islands on μc-Si is interpreted by constructing the model of lateral atomic migration, while this behavior on c-Si is ascribed to traditional uphill atomic diffusion. It is found that the aspect ratios of the preferential-grown super islands are higher than those of the Ostwald-ripening ones. The lower lateral growth rate of super islands due to the lower surface energy of AP-Si on the μc-Si buffer layer for the non-wetting of Ge at 700 °C and the stronger Si-Ge intermixing effect at 730 °C may be responsible for this aspect ratio difference.

  19. Modelling water vapour permeability through atomic layer deposition coated photovoltaic barrier defects

    Energy Technology Data Exchange (ETDEWEB)

    Elrawemi, Mohamed, E-mail: Mohamed.elrawemi@hud.ac.uk [EPSRC Centre for Innovative Manufacturing in Advanced Metrology, School of Computing and Engineering, University of Huddersfield, Huddersfield (United Kingdom); Blunt, Liam; Fleming, Leigh [EPSRC Centre for Innovative Manufacturing in Advanced Metrology, School of Computing and Engineering, University of Huddersfield, Huddersfield (United Kingdom); Bird, David, E-mail: David.Bird@uk-cpi.com [Centre for Process Innovation Limited, Sedgefield, County Durham (United Kingdom); Robbins, David [Centre for Process Innovation Limited, Sedgefield, County Durham (United Kingdom); Sweeney, Francis [EPSRC Centre for Innovative Manufacturing in Advanced Metrology, School of Computing and Engineering, University of Huddersfield, Huddersfield (United Kingdom)

    2014-11-03

    Transparent barrier films such as Al{sub 2}O{sub 3} used for prevention of oxygen and/or water vapour permeation are the subject of increasing research interest when used for the encapsulation of flexible photovoltaic modules. However, the existence of micro-scale defects in the barrier surface topography has been shown to have the potential to facilitate water vapour ingress, thereby reducing cell efficiency and causing internal electrical shorts. Previous work has shown that small defects (≤ 3 μm lateral dimension) were less significant in determining water vapour ingress. In contrast, larger defects (≥ 3 μm lateral dimension) seem to be more detrimental to the barrier functionality. Experimental results based on surface topography segmentation analysis and a model presented in this paper will be used to test the hypothesis that the major contributing defects to water vapour transmission rate are small numbers of large defects. The model highlighted in this study has the potential to be used for gaining a better understanding of photovoltaic module efficiency and performance. - Highlights: • A model of water vapour permeation through barrier defects is presented. • The effect of the defects on the water vapour permeability is investigated. • Defect density correlates with water vapour permeability. • Large defects may dominate the permeation properties of the barrier film.

  20. Depositional model of Permian Luodianian volcanic island and its impact on the distribution of fusulinid assemblage in southern Qinghai,Northwest China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Pan-riftizational tectonic activity reached climax at Luodianian (Permian) in the East Tethyan Domain, Qinghai-Tibet Plateau. Because of eruptive volcanics and influence of terrigenous materials, a complex volcanic-sedimentary landform formed on the sea floor in southern Qinghai. Four sedimentary facies types were recognized based on detailed field mapping. Spatially, platform facies volcanic-limestone type was located at the center belt approximately trending NWW, surrounded by shallow water slope facies tuff/tuffite type at the two flanks and deep water slope facies breccia/calcirudite at the most outside. The depression facies sandstone-mudstone type, which comprised mainly mudstone, de-posited between volcanic islands (platform facies volcanic-limestone type). Based on the field map-ping and stratigraphic section data, seven rift-related sedimentary facies were recognized and a depo-sitional model for volcanic island was proposed. It is revealed that some volcanic island chain formed quickly and intermittently in the Qamdo Block during violent eruption, and small carbonate reef, shoal, platform occurred above or on edge of volcanic island, and some slope sedimentary facies surrounded volcano island chain during dormant period of volcanic activities. Three types of fusulinid assemblages were distinguished in the carbonate rocks, which deposited in varied positions of a palaeo-volcanic island: (1) Misellina-Schwagerina assemblage occurred above or on edge of volcanic island, (2) Para-fusulina assemblage was located at restricted depression facies among volcanic islands or carbonate platform, and (3) the reworked Pseudofusulina-Schwagerina assemblage occurred at slope facies near margin of volcanic island, which originally deposited in the shallow-water carbonate platform, then collapsed along the volcanic island margin with fusulinid-bearing grain-supported carbonate con-glomerate or calcirudite, and finally re-deposited on the deeper slope. The sedimentary

  1. Depositional model of Permian Luodianian volcanic island and its impact on the distribution of fusulinid assemblage in southern Qinghai, Northwest China

    Institute of Scientific and Technical Information of China (English)

    NIU ZhiJun; XU AnWu; WANG JianXiong; DUAN QiFa; ZHAO XiaoMing; YAO HuaZhou

    2008-01-01

    Pan-riftizational tectonic activity reached climax at Luodianian (Permian) in the East Tethyan Domain,Qinghai-Tibet Plateau. Because of eruptive volcanics and influence of terrigenous materials, a complex volcanic-sedimentary landform formed on the sea floor in southern Qinghai. Four sedimentary facies types were recognized based on detailed field mapping. Spatially, platform facies volcanic-limestone type was located at the center belt approximately trending NWW, surrounded by shallow water slope facies tuff/tuffite type at the two flanks and deep water slope facies breccia/calcirudite at the most outside. The depression facies sandstone-mudstone type, which comprised mainly mudstone, deposited between volcanic islands (platform facies volcanic-limestone type). Based on the field mapping and stratigraphic section data, seven rift-related sedimentary facies were recognized and a depositional model for volcanic island was proposed. It is revealed that some volcanic island chain formed quickly and intermittently in the Qamdo Block during violent eruption, and small carbonate reef, shoal,platform occurred above or on edge of volcanic island, and some slope sedimentary facies surrounded volcano island chain during dormant period of volcanic activities. Three types of fusulinid assemblages were distinguished in the carbonate rocks, which deposited in varied positions of a palaeo-volcanic island: (1) Misellina- Schwagerina assemblage occurred above or on edge of volcanic island, (2) Parafusulina assemblage was located at restricted depression facies among volcanic islands or carbonate platform, and (3) the reworked Pseudofusulina-Schwagerina assemblage occurred at slope facies near margin of volcanic island, which originally deposited in the shallow-water carbonate platform, then collapsed along the volcanic island margin with fusulinid-bearing grain-supported carbonate conglomerate or calcirudite, and finally re-deposited on the deeper slope. The sedimentary sequence

  2. Tunnel spin injection into graphene using Al2O3 barrier grown by atomic layer deposition on functionalized graphene surface

    OpenAIRE

    Yamaguchi, Takehiro; Masubuchi, Satoru; Iguchi, Kazuyuki; Moriya, Rai; Machida, Tomoki

    2011-01-01

    We demonstrate electrical tunnel spin injection from a ferromagnet to graphene through a high-quality Al2O3 grown by atomic layer deposition (ALD). The graphene surface is functionalized with a self-assembled monolayer of 3,4,9,10-perylene tetracarboxylic acid (PTCA) to promote adhesion and growth of Al2O3 with a smooth surface. Using this composite tunnel barrier of ALD-Al2O3 and PTCA, a spin injection signal of 30 ohm has been observed from non-local magnetoresistance measurements at 45 K, ...

  3. Efficient, air-stable colloidal quantum dot solar cells encapsulated using atomic layer deposition of a nanolaminate barrier

    KAUST Repository

    Ip, Alexander H.

    2013-12-23

    Atomic layer deposition was used to encapsulate colloidal quantum dot solar cells. A nanolaminate layer consisting of alternating alumina and zirconia films provided a robust gas permeation barrier which prevented device performance degradation over a period of multiple weeks. Unencapsulated cells stored in ambient and nitrogen environments demonstrated significant performance losses over the same period. The encapsulated cell also exhibited stable performance under constant simulated solar illumination without filtration of harsh ultraviolet photons. This monolithically integrated thin film encapsulation method is promising for roll-to-roll processed high efficiency nanocrystal solar cells. © 2013 AIP Publishing LLC.

  4. Diffusion barrier properties of atomic-layer-deposited iridium thin films on Cu/Ir/Si structures

    International Nuclear Information System (INIS)

    We investigated the diffusion barrier properties of an atomic-layer-deposited 12-nm-thick iridium (Ir) thin film as functions of the thermal treatment temperature. Up to a temperature of 500 .deg. C, the Ir thin film maintained its initial configuration, preventing the penetration of the Cu layer into Si through the Ir layer. The thermal stability of the Ir layer up to 500 .deg. C was confirmed by using high resolution transmission electron microscopy, Auger electron microscopy, and X-ray diffraction. In contrast, when the Ir layer was thermally annealed at 600 .deg. C, copper silicide was formed, and interdiffusion of Cu and Ir was observed.

  5. Effect of particle size on silver nanoparticle deposition onto dielectric barrier discharge (DBD) plasma functionalized polyamide fabric

    OpenAIRE

    Vu, Nguyen Khanh; Zille, Andrea; Oliveira, F. R.; Carneiro, Noémia; Souto, A. Pedro

    2013-01-01

    The effect on the deposition of three different size silver nanoparticles (AgNPs) onto a polyamide 6,6 (PA) fabric pre-treated using air dielectric barrier discharge (DBD) plasma was investigated. The SEM, EDS, and XPS analysis confirm that the smaller is the diameter of AgNPs, the higher the amount of adsorbed NPs on the PA. The DBD treatment on PA induces a threefold increase in Ag adsorption. The result confirms a dual effect on the wettability of the plasma treated PA substrate. AgNPs sli...

  6. Impact Of Coral Structures On Wave Directional Spreading Across A Shallow Reef Flat - Lizard Island, Northern Great Barrier Reef

    Science.gov (United States)

    Leon, J. X.; Baldock, T.; Callaghan, D. P.; Hoegh-guldberg, O.; Mumby, P.; Phinn, S. R.; Roelfsema, C. M.; Saunders, M. I.

    2013-12-01

    Coral reef hydrodynamics operate at several and overlapping spatial-temporal scales. Waves have the most important forcing function on shallow (stress, directly mixing water (temperature and nutrients) and transporting sediments, nutrients and plankton. Reef flats are very effective at dissipating wave energy and providing an important ecosystem service by protecting highly valued shorelines. The effectiveness of reef flats to dissipate wave energy is related to the extreme hydraulic roughness of the benthos and substrate composition. Hydraulic roughness is usually obtained empirically from frictional-dissipation calculations, as detailed field measurements of bottom roughness (e.g. chain-method or profile gauges) is a very labour and time-consuming task. In this study we measured the impact of coral structures on wave directional spreading. Field data was collected during October 2012 across a reef flat on Lizard Island, northern Great Barrier Reef. Wave surface levels were measured using an array of self-logging pressure sensors. A rapid in situ close-range photogrammetric method was used to create a high-resolution (0.5 cm) image mosaic and digital elevation model. Individual coral heads were extracted from these datasets using geo-morphometric and object-based image analysis techniques. Wave propagation was modelled using a modified version of the SWAN model which includes the measured coral structures in 2m by 1m cells across the reef. The approach followed a cylinder drag approach, neglecting skin friction and inertial components. Testing against field data included bed skin friction. Our results show, for the first time, how the variability of the reef benthos structures affects wave dissipation across a shallow reef flat. This has important implications globally for coral reefs, due to the large extent of their area occupied by reef flats, particularly, as global-scale degradation in coral reef health is causing a lowering of reef carbonate production that

  7. Robust TaNx diffusion barrier for Cu-interconnect technology with subnanometer thickness by metal-organic plasma-enhanced atomic layer deposition

    International Nuclear Information System (INIS)

    TaNx diffusion barriers with good barrier properties at subnanometer thickness were deposited by plasma-enhanced atomic layer deposition (PE-ALD) from pentakis(dimethylamino)Ta. Hydrogen and/or nitrogen plasma was used as reactants to produce TaNx thin films with a different nitrogen content. The film properties including the carbon and oxygen impurity content were affected by the nitrogen flow during the process. The deposited film has nanocrystalline grains with hydrogen-only plasma, while the amorphous structure was obtained for nitrogen plasma. The diffusion barrier properties of deposited TaN films for Cu interconnects have been studied by thermal stress test based on synchrotron x-ray diffraction. The results indicate that the PE-ALD TaN films are good diffusion barriers even at a small thickness as 0.6 nm. Better diffusion barrier properties were obtained for higher nitrogen content. Based on a diffusion kinetics analysis, the nanocrystalline microstructure of the films was responsible for the better diffusion barrier properties compared to polycrystalline PE-ALD TaN films deposited from TaCl5

  8. Characterization of early microbial communities on volcanic deposits along a vegetation gradient on the island of Miyake, Japan.

    Science.gov (United States)

    Guo, Yong; Fujimura, Reiko; Sato, Yoshinori; Suda, Wataru; Kim, Seok-won; Oshima, Kenshiro; Hattori, Masahira; Kamijo, Takashi; Narisawa, Kazuhiko; Ohta, Hiroyuki

    2014-01-01

    The 2000 eruption of Mount Oyama on the island of Miyake (Miyake-jima) created a unique opportunity to study the early ecosystem development on newly exposed terrestrial substrates. In this study, bacterial and fungal communities on 9- and 11-year-old volcanic deposits at poorly to fully vegetation-recovered sites in Miyake-jima, Japan, were characterized by conventional culture-based methods and pyrosequencing of 16S rRNA and 18S rRNA genes. Despite the differences in the vegetation cover, the upper volcanic deposit layer samples displayed low among-site variation for chemical properties (pH, total organic carbon, and total nitrogen) and microbial population densities (total direct count and culturable count). Statistical analyses of pyrosequencing data revealed that the microbial communities of volcanic deposit samples were phylogenetically diverse, in spite of very low-carbon environmental conditions, and their diversity was comparable to that in the lower soil layer (buried soil) samples. Comparing with the microbial communities in buried soil, the volcanic deposit communities were characterized by the presence of Betaproteobacteria and Gammaproteobacteria as the main bacterial class, Deinococcus- Thermus as the minor bacterial phyla, and Ascomycota as the major fungal phyla. Multivariate analysis revealed that several bacterial families and fungal classes correlated positively or negatively with plant species. PMID:24463576

  9. Coal deposits on the Faroe Islands: preliminary geological and compositional characteristics

    Czech Academy of Sciences Publication Activity Database

    Kuboušková, S.; Krmíček, Lukáš

    Brno: Masarykova univerzita, 2015 - (Ondruch, J.; Hrbáček, F.; Nývlt, D.; Láska, K.). s. 31-32 [Students in Polar Research Conference 2015. 20.04.2015-22.04.2015, Brno] Institutional support: RVO:67985831 Keywords : coal * Faroe Islands * mining Subject RIV: DB - Geology ; Mineralogy

  10. Effects of argon and oxygen flow rate on water vapor barrier properties of silicon oxide coatings deposited on polyethylene terephthalate by plasma enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    Plasma polymer coatings were deposited from hexamethyldisiloxane on polyethylene terephthalate (PET) substrates while varying the operating conditions, such as the Ar and O2 flow rates, at a fixed radio frequency power of 300 W. The water vapor transmission rate (WVTR) of the untreated PET was 54.56 g/m2/day and was decreased after depositing the silicon oxide (SiOx) coatings. The minimum WVTR, 0.47 g/m2/day, was observed at Ar and O2 flow rates of 4 and 20 sccm, respectively, with a coating thickness of 415.44 nm. The intensity of the peaks for the Si-O-Si bending at 800-820 cm-1 and Si-O-Si stretching at 1000-1150 cm-1 varied depending on the Ar and O2 flow rates. The contact angle of the SiOx coated PET increased as the Ar flow rate was increased from 2 to 8 sccm at a fixed O2 flow rate of 20 sccm. It decreased gradually as the oxygen flow rate increased from 12 to 28 sccm at a fixed Ar carrier gas flow rate. The examination by atomic force microscopy revealed a correlation of the SiOx morphology and the water vapor barrier performance with the Ar and O2 flow rates. The roughness of the deposited coatings increased when either the O2 or Ar flow rate was increased.

  11. Mineral barrier systems for the treatment of metal-polluted water from an alum shale deposit

    OpenAIRE

    Gärtner, Isabell

    2014-01-01

    Oil and gas were recovered from alum shale (black shale) at Kvarntorp, Närke,during a period of 24 years. One of the remnants of this industry is a 100 m highdeposit with high contents of uranium, arsenic, molybdenum, vanadium and otherelements. Presently the leakage of metals from the deposit into nearby streams israther modest but will most likely accelerate in the near future. One way to preventan uncontrolled leakage of these elements from the deposit into the environmentwould be to insta...

  12. Combining cosmogenic radionuclides and amino acid racemization to date late Pliocene glacial deposits exposed on Baffin Island, Nunavut, Canada

    Science.gov (United States)

    Refsnider, K. A.; Miller, G. H.

    2009-12-01

    Sequences of glacial deposits spanning the Quaternary are valuable archives recording the effects of glaciation on landscapes through time, but determining the age of such deposits has long challenged geologists. The recent advances in cosmogenic radionuclide (CRN) measurement has made it possible to date some of these deposits, but dating buried glacial sediments in most settings remains problematic. Here we explore a new approach to date the oldest glacial deposits in the Plio-Pleistocene Clyde Foreland Formation of Baffin Island. This formation, approximately 40 m thick, includes interlayered shell-bearing marine, glaciomarine, and glacial sediments deposited along the northern margin of the Laurentide Ice Sheet and earlier continental ice sheets. Previous work on foraminifera assemblages suggests that the deposits span the last ≥2 Ma. By combining CRN measurements (10Be and 26Al) from the glacial units and measurements of the D-alloisoleucine:L-isoleucine ratios (A/I) in valves of the mollusk Hiatella arctica in the marine units overlying a particular glacial deposit, we can calculate the age of the glacial deposit. Because the post-burial temperature history for the mollusks preserved in the Clyde Foreland Formation is poorly constrained, A/I ratios alone cannot be used to determine absolute ages. Instead, we use A/I ratios to identify sediment packages of discrete ages and define a step-wise burial history function for glacial units. A/I ratios of all packages (CRN inventories require that post-burial muogenic production is accounted for using the burial history function. We apply a numerical model to calculate the duration of burial from the measured CRN concentrations for a given inherited CRN inventory. But because this initial inventory is unknown, a single CRN sample/burial history combination will not provide a unique age solution. Instead, measurements from multiple localities where a particular glacial deposit has differing burial histories (i

  13. Shallow hydrothermal alteration and permeability changes in pyroclastic deposits: a case study at La Fossa cone (Vulcano island, Italy):

    Science.gov (United States)

    Cangemi, Marianna; Madonia, Paolo; Speziale, Sergio; Oliveri, Ygor

    2016-04-01

    La Fossa cone at Vulcano, the southernmost island of the Aeolian volcanic archipelago (Italy), has been characterized by an intense fumarolic activity since its last eruption dated 1888-90. Mineralogical alteration induced by shallow hydrothermal circulation has significantly reduced the permeability of the volcanic products, causing important feedbacks on the circulation of fluids in the shallowest portion of the volcanic edifice. The summit area of the cone is sealed by a quite continuous coating surface, fostering the condensation of hydrothermal fluids inside the volcanic edifice. The combination of fractures and volcano-stratigraphic discontinuities, conveying hydrothermal fluids, makes significant rock volumes prone to slide seaward, as occurred in 1988 during the main unrest experienced by Vulcano island since its last eruption. Similar instability conditions are found over the Forgia Vecchia crater rim area, formed by phreatic activity on the NE flank of the cone, where tensile fracturing and hydrothermal circulation interacts with mutual negative feedbacks. In the behalf of the DPC-INGV V3 Project 2012-15 we investigated the mineralogical composition and the hydraulic conductivity (under saturated conditions) of volcanic deposits potentially prone to hydrothermal fluid circulation, for evaluating their ability in retaining water, creating favourable conditions for gravitational instability. We also measured rainfall rate and volumetric soil moisture content in two automated stations located in different areas, with and without active hydrothermal circulation. We found that hydrothermal alteration transforms volcanic products into clay minerals, significantly reducing permeability of volcanic deposits. Argillified volcanic materials show background water contents, modulated by impulsive increments following rainfalls, higher than unaltered pyroclastic deposits, due to the combination of lower permeability and direct condensation of hydrothermal vapour. The

  14. Theoretical analysis of ion kinetic energies and DLC film deposition by CH4+Ar (He) dielectric barrier discharge plasmas

    Institute of Scientific and Technical Information of China (English)

    Liu Yan-Hong; Zhang Jia-Liang; Ma Teng-Cai; Li Jian; Liu Dong-Ping

    2007-01-01

    The kinetic energy of ions in dielectric barrier discharge plasmas are analysed theoretically using the model of binary collisions between ions and gas molecules. Langevin equation for ions in other gases, Blanc law for ions in mixed gases, and the two-temperature model for ions at higher reduced field are used to determine the ion mobility. The kinetic energies of ions in CH4 + Ar(He) dielectric barrier discharge plasma at a fixed total gas pressure and various Ar (He)concentrations are calculated. It is found that with increasing Ar (He) concentration in CH4 + Ar (He) from 20% to 83%,the CH4+ kinetic energy increases from 69.6 (43.9) to 92.1 (128.5)eV, while the Ar+ (He+) kinetic energy decreases from 97 (145.2) to 78.8 (75.5)eV. The increase of CH4+ kinetic energy is responsible for the increase of hardness of diamond-like carbon films deposited by CH4 + Ar (He) dielectric barrier discharge without bias voltage over substrates.

  15. Depositional model of Early Permian reef-island ocean inEastern Kunlun

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Many fusulinid fossils have been found in thin- to middle-bedded limestones which aredistributed between the Early Permian limestone hills and formerly considered as Early Triassic.The fusulinid fossils, identified as Neoshwagerina sp., Verbeekina sp. and Schwagerina sp., canalso be found in massive limestone hills. At the same time, Early Permian radiolarian chert of deepbasin facies was discovered in Animaqing. All the above show that the massive limestone hills,thin- to middle-bedded limestones and radiolarian chert belong to syndeposits in Early Permianocean. The sediments in the study area can roughly be divided into three types: shallow facies,basin facies and transitional facies. The carbonate buildup can be subdivided into massive bioclas-tic limestone and reef framestone. Basin facies contains thin- or middle-bedded limestone, abyssalred mudstone or ooze, blue-green mudstone and radiolarian chert. Transitional facies includes reeftalus and platformal skirt facies. The Early Permian ocean in Eastern Kunlun is recognized as akind of reef-island ocean environment according to distribution and composition of different facies.The reef-island ocean in Eastern Kunlun is characterized by reef islands (or carbonate buildups)alternating with basins, complicated sea-floor topography, sharp facial change and well-developedreefs

  16. Microstructure of thermal barrier coatings deposited by APS method with application of new type ceramic powders

    Directory of Open Access Journals (Sweden)

    M. Góral

    2012-12-01

    Full Text Available Purpose: The paper presents results of structural research into thermal barrier coatings obtained by the APS. For the base the Rene 80 alloy was used, whereas a MeCrAlY-type multicomponent alloy was used for an interlayer.Design/methodology/approach: Throughout the research an optic microscope as well as a scanning electron microscope were employed. Measurements of the formed structure’s porosity were taken.Findings: It has been observed that application of novelty ceramic powders allows for a possibility of forming thermal barrier coatings, which can be used for protecting of the combustion chamber’s surface as well as turbine’s blades in an aircraft engine.Research limitations/implications: Further research into resistance to oxidation of these coatings seems necessary for experimental determination of their actual work temperature.Practical implications: They can be successfully applied in automotive industry for coating of petrol or diesel engine’s components.Originality/value: Investigation into possible applications of two-layer and composite coatings, which may improve the work temperature of thermal barrier coatings, is feasible.

  17. Properties of Plasma Enhanced Chemical Vapor Deposition Barrier Coatings and Encapsulated Polymer Solar Cells

    International Nuclear Information System (INIS)

    In this paper, we report silicon oxide coatings deposited by plasma enhanced chemical vapor deposition technology (PECVD) on 125 μm polyethyleneterephthalate (PET) surfaces for the purpose of the shelf lifetime extension of sealed polymer solar cells. After optimization of the processing parameters, we achieved a water vapor transmission rate (WVTR) of ca. 10−3 g/m2/day with the oxygen transmission rate (OTR) less than 0.05 cc/m2/day, and succeeded in extending the shelf lifetime to about 400 h in encapsulated solar cells. And then the chemical structure of coatings related to the properties of encapsulated cell was investigated in detail. (plasma technology)

  18. Composition, structure and properties of gradient thermal barrier coatings (TBCs) produced by electron beam physical vapor deposition (EB-PVD)

    International Nuclear Information System (INIS)

    Gradient thermal barrier coatings (TBCs) along with the bond coat were produced by one and the same technological cycle using electron beam physical vapor deposition (EB-PVD) of an MCrAlY ingot, then of an Al-Al2O3-ZrO2(Y2O3) tablet (pressed multicomponent powder mixture) and finally of a ZrO2-7 wt.% Y2O3 ceramic ingot. At the evaporation temperature used, vapor pressures of the tablet components decrease in the direction: AlapproachesAl2O3approachesZrO2(Y2O3). The evaporation of these constituents also proceeds in the same order. As a result, a transition zone [with composition and structure gradients - transition gradient zone (TGZ)] - forms between the bond coat and outer ZrO2-7 wt.% Y2O3 ceramic layer during deposition. The TGZ constitution and structure are primarily determined by the aluminum, Al2O3 and ZrO2 contents of the tablet. As a consequence of liquid aluminum participation in the coating deposition process, a thin layer of β-phase (NiAl), smoothly transitions to an Al2O3 layer and then to ZrO2-7 wt.% Y2O3. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  19. Antibacterial and barrier properties of oriented polymer films with ZnO thin films applied with atomic layer deposition at low temperatures

    International Nuclear Information System (INIS)

    Concerns on food safety, and need for high quality and extended shelf-life of packaged foods have promoted the development of antibacterial barrier packaging materials. Few articles have been available dealing with the barrier or antimicrobial properties of zinc oxide thin films deposited at low temperature with atomic layer deposition (ALD) onto commercial polymer films typically used for packaging purposes. The purpose of this paper was to study the properties of ZnO thin films compared to those of aluminum oxide. It was also possible to deposit ZnO thin films onto oriented polylactic acid and polypropylene films at relatively low temperatures using ozone instead of water as an oxidizing precursor for diethylzinc. Replacing water with ozone changed both the structure and the chemical composition of films deposited on silicon wafers. ZnO films deposited with ozone contained large grains covered and separated probably by a more amorphous and uniform layer. These thin films were also assumed to contain zinc salts of carboxylic acids. The barrier properties of a 25 nm ZnO thin film deposited with ozone at 100 °C were quite close to those obtained earlier with ALD Al2O3 of similar apparent thickness on similar polymer films. ZnO thin films deposited at low temperature indicated migration of antibacterial agent, while direct contact between ZnO and Al2O3 thin films and bacteria promoted antibacterial activity. - Highlights: • Thin films were grown from diethylzinc also with ozone instead of water at 70 and 100 °C. • ZnO films deposited with diethylzinc and ozone had different structures and chemistries. • Best barrier properties obtained with zinc oxide films close to those obtained with Al2O3 • Ozone as oxygen source provided better barrier properties at 100 °C than water. • Both aluminum and zinc oxide thin films showed antimicrobial activity against E. coli

  20. Effects of deposition conditions on gas-barrier performance of SiOxNy thin films formed via ion-beam-assisted vapor deposition

    International Nuclear Information System (INIS)

    SiOxNy thin films were synthesized via ion-beam-assisted vapor deposition (IVD) where deposition of SiOx was irradiated by nitrogen ions. Firstly, reasonable-cost evaporation materials showing less splashing for the SiOx films were investigated by selecting appropriate sintering condition regimes of Si and SiO2 mixed powders. The SiOxNy thin films on a polyethylene terephtalate film substrate obtained via IVD showed a low oxygen transmission rate (OTR) of less than 1 cm3/m2 day. Effective nitrogen ion irradiation energy per atom was 8 eV/at. or greater, which is consistent with regimes where densification of thin films is reported to occur. Higher N2 partial pressure yielded a lower OTR and a higher nitrogen atomic ratio of the films obtained. It is suggested that the improvement in gas-barrier performance resulted from densification and chemical change of the films due to energy addition and nitrification produced by nitrogen ion-beam irradiation

  1. U-Th age distribution of coral fragments from multiple rubble ridges within the Frankland Islands, Great Barrier Reef: Implications for past storminess history

    Science.gov (United States)

    Liu, Entao; Zhao, Jian-xin; Feng, Yue-xing; Leonard, Nicole D.; Clark, Tara R.; Roff, George

    2016-07-01

    Prograded coral rubble ridges have been widely used as archives for reconstructing long-term storm or storminess history. Chronologies of ridge systems in previous studies are often based on a limited number of low-resolution radiocarbon or optically-stimulated luminescence (OSL) ages per ridge (usually only one age per ridge), which carry intrinsic age uncertainties and make interpretation of storm histories problematic. To test the fidelity of storm ridges as palaeo-storm archives, we used high-precision U-Th dating to examine whether different samples from a single ridge are temporally constrained. We surveyed three transects of ridge systems from two continental islands (Normanby Island and High Island) within the Frankland Islands, Great Barrier Reef (GBR), and obtained 96 U-Th dates from coral rubble samples collected from within and between different ridges. Our results revealed significant differences in age ranges between the two islands. The steeper and more defined rubble ridges present on Normanby Island revealed that the majority of U-Th ages (over 60%) from a single ridge clustered within a narrow age range (∼100 years). By contrast, the lower and less defined ridges on High Island, which were more likely formed during both storm and non-storm high-energy events, revealed significant scatter in age distribution (>>200 years) with no notable clustering. The narrower age ranges obtained from the steeper and more defined rubble ridges suggest that previous approaches of using either limited samples from a single ridge or low-precision dating methods to establish chronologies are generally valid at centennial to millennial timescales, although caution must be taken to use such approaches for storm history reconstruction on shorter timescales (e.g. decadal). The correlation between U-Th mortality ages of coral rubble and historical stormy periods highlights the possibility of using coral rubble age distribution from rubble ridges to reconstruct the long

  2. Identification of plant communities on barrier islands by using spatial properties derived from close-range and low-altitude UAV photos

    Science.gov (United States)

    Su, L.; Gibeaut, J. C.

    2014-12-01

    Barrier islands reduce impacts of storms and hurricanes on coastal areas, and provide habitat for migrating waterfowl and other species such as turtles. Scientific investigations are prerequisites to effective habitat management. Different habitats usually associate with different prevalent plant associations. For examples, emergent areas closest to estuarine waters consist of regularly flooded salt-tolerant grasses. In brackish areas, species composition changes to brackish-water assemblage. Conventional mapping methods include visual interpretation on aerial photographs and field investigation, which is conducted to compare various plant communities in the field with corresponding photographic signatures on aerial photos for mapping purposes. The low-cost, low-altitude flying UAV provides an opportunity to obtain the vital plant community information. The UAV remote sensing system usually adopts off-the-shelf cameras. Although the cameras have low spectral and radiometric resolution, they typically have high spatial resolution. The prevalent plant associations may have similar spectral reflectance, however they usually have different appearances. The hyperspatial images acquired by close-range cameras and low-altitude UAV cameras are used to generate geometric characterization of plant communities. The experiment has two study areas, transects on Mustang Island and beach on South Padre Island. The images used in the experiment consists of close-range photos along transects on Mustang Island and the UAV images over South Padre Island beach. After interior orientation and geo-orthorectification, predominant spatial properties such as texture and geometric properties are calculated on these images. The effectiveness of these parameters for identifying plant communities will be evaluated. The experiment tries to build the spatial signatures of typical coastal plant communities. Positive results will further the use of UAV technology into coastal environmental

  3. Integration of molecular-layer-deposited aluminum alkoxide interlayers into inorganic nanolaminate barriers for encapsulation of organic electronics with improved stress resistance

    International Nuclear Information System (INIS)

    Diffusion barrier stacks for the encapsulation of organic electronics made from inorganic nanolaminates of Al2O3 and TiO2 with aluminum alkoxide interlayers have been deposited by atomic layer deposition (ALD) and molecular layer deposition (MLD). As a part of the MLD process development, the deposition of aluminum alkoxide with low a density of about 1.7 g/cm3 was verified. The ALD/MLD diffusion barrier stack is meant to be deposited either on a polymer film, creating a flexible barrier substrate, or on top of a device on glass, creating a thin-film encapsulation. In order to measure the water vapor transmission rate (WVTR) through the barrier, the device is replaced by a calcium layer acting as a water sensor in an electrical calcium test. For the barrier stack applied as thin-film encapsulation on glass substrates, high resolution scanning electron microscopy investigations indicate that the inorganic nanolaminates without MLD interlayers are brittle as they crack easily upon the stress induced by the corroding calcium below. The introduction of up to three MLD interlayers of 12 nm each into the 48 nm barrier film laminate successfully mitigates stress issues and prevents the barrier from cracking. Using the three MLD interlayer configurations on glass, WVTRs of as low as 10−5 g/m2/d are measured at 38 °C and 32% relative humidity. On polymer barrier substrates, the calcium is evaporated onto the barrier stack and encapsulated with a cavity glass. In this configuration, the corroding calcium has space for expansion and gas release without affecting the underlying barrier film. In consequence, a WVTR of about 3 × 10−3 g/m2/d is measured for all samples independently of the number of MLD interlayers. In conclusion, a stabilization and preservation of the ALD barrier film against mechanical stress is achieved by the introduction of MLD interlayers into the inorganic nanolaminate

  4. Integration of molecular-layer-deposited aluminum alkoxide interlayers into inorganic nanolaminate barriers for encapsulation of organic electronics with improved stress resistance

    Energy Technology Data Exchange (ETDEWEB)

    Hossbach, Christoph, E-mail: christoph.hossbach@tu-dresden.de; Fischer, Dustin; Albert, Matthias; Bartha, Johann W. [Institute of Semiconductor and Microsystems Technology, Technische Universität Dresden, 01187 Dresden (Germany); Nehm, Frederik, E-mail: frederik.nehm@iapp.de; Klumbies, Hannes; Müller-Meskamp, Lars; Leo, Karl [Institut für Angewandte Photophysik, Technische Universität Dresden, 01062 Dresden (Germany); Singh, Aarti; Richter, Claudia; Schroeder, Uwe; Mikolajick, Thomas [Nanoelectronics Materials Laboratory NaMLab gGmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany)

    2015-01-15

    Diffusion barrier stacks for the encapsulation of organic electronics made from inorganic nanolaminates of Al{sub 2}O{sub 3} and TiO{sub 2} with aluminum alkoxide interlayers have been deposited by atomic layer deposition (ALD) and molecular layer deposition (MLD). As a part of the MLD process development, the deposition of aluminum alkoxide with low a density of about 1.7 g/cm{sup 3} was verified. The ALD/MLD diffusion barrier stack is meant to be deposited either on a polymer film, creating a flexible barrier substrate, or on top of a device on glass, creating a thin-film encapsulation. In order to measure the water vapor transmission rate (WVTR) through the barrier, the device is replaced by a calcium layer acting as a water sensor in an electrical calcium test. For the barrier stack applied as thin-film encapsulation on glass substrates, high resolution scanning electron microscopy investigations indicate that the inorganic nanolaminates without MLD interlayers are brittle as they crack easily upon the stress induced by the corroding calcium below. The introduction of up to three MLD interlayers of 12 nm each into the 48 nm barrier film laminate successfully mitigates stress issues and prevents the barrier from cracking. Using the three MLD interlayer configurations on glass, WVTRs of as low as 10{sup −5} g/m{sup 2}/d are measured at 38 °C and 32% relative humidity. On polymer barrier substrates, the calcium is evaporated onto the barrier stack and encapsulated with a cavity glass. In this configuration, the corroding calcium has space for expansion and gas release without affecting the underlying barrier film. In consequence, a WVTR of about 3 × 10{sup −3} g/m{sup 2}/d is measured for all samples independently of the number of MLD interlayers. In conclusion, a stabilization and preservation of the ALD barrier film against mechanical stress is achieved by the introduction of MLD interlayers into the inorganic nanolaminate.

  5. Gas barrier properties of hydrogenated amorphous carbon films coated on polymers by surface-wave plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Gas barrier characteristics of hydrogenated amorphous carbon (a-C:H) thin films coated on polymer sheets using the large-area surface-wave plasma (SWP) were studied. With SWP in He and CH4 gas mixture, a-C:H films were deposited over about 100 mm in diameter on high density polyethylene or polyethylene terephthalate (PET) sheets at temperature less than 70 deg. C. Experimental results show that gas permeation in the case of a-C:H film coating on PET sheet was reduced by a factor of more than 150 (0.27 cm3/m2 day atm), compared with that before coating. Plasma characteristics of SWP, such as electron density and electron energy distribution functions, and other film characteristics measured with Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and atomic force microscope are presented and discussed

  6. Influence of control and material parameters on island density in early stage of pulsed laser deposition

    Czech Academy of Sciences Publication Activity Database

    Mašín, Martin; Kotrla, Miroslav

    2012-01-01

    Roč. 520, č. 15 (2012), s. 4965-4970. ISSN 0040-6090 R&D Projects: GA ČR GA202/09/0775 Institutional research plan: CEZ:AV0Z10100520 Keywords : Monte Carlo simulations * pulsed laser deposition * surface diffusion * epitaxy * growth * nucleation Subject RIV: BE - Theoretical Physics Impact factor: 1.604, year: 2012

  7. A review of the MIS 5e highstand deposits from Santa Maria Island (Azores, NE Atlantic): palaeobiodiversity, palaeoecology and palaeobiogeography

    Science.gov (United States)

    Ávila, Sérgio P.; Melo, Carlos; Silva, Luís; Ramalho, Ricardo S.; Quartau, Rui; Hipólito, Ana; Cordeiro, Ricardo; Rebelo, Ana Cristina; Madeira, Patrícia; Rovere, Alessio; Hearty, Paul J.; Henriques, Diamantino; Silva, Carlos Marques da; Martins, António M. de Frias; Zazo, Caridad

    2015-04-01

    The privileged location of Santa Maria Island (Azores archipelago) in the middle of the North Atlantic makes the fossiliferous outcrops on this island of utmost importance to gain a better understanding of how coeval living communities relate to the broader evolutionary and biogeographic history of the Atlantic basin during the late Neogene and the Quaternary. Here we focus on this island's MIS 5e fossil record, offering a comprehensive review on the palaeobiodiversity, palaeoecology and palaeobiogeography of the biota living in the mid North Atlantic during this interglacial. Several studies in oceanic islands stress the huge impact of sea level changes on insular communities. Pleistocene sea-level changes occur during the short-time events known as "Terminations" (associated to glacial/interglacial shifts) as well as with the onset of glaciations (associated to interglacial/glacial shifts). Both are responsible for extinctions and local disappearance of species, bottleneck effects and formation of new species, resulting in community structure changes. This work increases the number of fossil marine taxa reported from the Last Interglacial deposits of Santa Maria to 143 species. All the 19 new records are molluscs (13 gastropods and 6 bivalves), thus increasing the number of fossil molluscs to 136 species. Although thermophilic members of the "Senegalese" tropical fauna were found in these deposits, many of the most emblematic species (e.g., Persististrombus latus (=Strombus bubonius), Cymbula safiana, Harpa doris, Cardita senegalensis, Barbatia plicata, Ctena eburnea or Hyotissa hyotis) are absent, suggesting that they did not reach the Azores. Our results indicate that the main differences between the species composition of the MIS 5e and the present-day shallow-water Azorean communities are probably due to the dropping of sea surface temperature associated with the onset of the last glaciation, which had both direct and indirect effects on species ecology. A

  8. The effectiveness of Ti implants as barriers to carbon diffusion in Ti implanted steel under CVD diamond deposition conditions

    International Nuclear Information System (INIS)

    The growth of chemical vapour deposited (CVD) diamond onto iron based substrates complicated by preferential soot formation and carbon diffusion into the substrate [1], leading to poor quality films and poor adhesion. In the initial stages of exposure to a microwave plasma, a layer of graphite is rapidly formed on an untreated Fe based substrate. Once this graphite layer reaches a certain thickness, reasonable quality diamond nucleates and grows upon it. However, the diamond film easily delaminates from the substrate, the weak link being the graphitic layer. Following an initial success in using a TiN barrier layer to inhibit the formation of such a graphitic layer the authors report on attempts to use an implanted Ti layer for the same purpose. This work was prompted by observation that, although the TiN proved to be an extremely effective diffusion barrier, adhesion may be further enhanced by the formation of a TiC interface layer between the diamond film and the Fe substrate. 3 refs., 6 figs

  9. Electroless nickel alloy deposition on SiO2 for application as a diffusion barrier and seed layer in 3D copper interconnect technology.

    Science.gov (United States)

    Kim, Tae-Yoo; Son, Hwa-Jin; Lim, Seung-Kyu; Song, Young-Il; Park, Hwa-Sun; Suh, Su-Jeong

    2014-12-01

    Electroless Ni-P films were investigated with the aim of application as barrier and seed layers in 3D interconnect technology. Different shapes of blind-via holes were fabricated with a deep reactive ion etcher and SiO2 formed on these holes as an insulating layer. The surface of the substrate has been made hydrophilic by O2 plasma treatment with 100 W of power for 20 min. Electroless Ni-P films were deposited as both a diffusion barrier and a seed layer for Cu filling process. Prior to plating, substrates were activated in a palladium chloride solution after sensitization in a tin chloride solution with various conditions in order to deposit uniform films in TSV. After the formation of the electroless barrier layer, electro Cu was plated directly on the barrier layer. Ni-P films fabricated in blind-via holes were observed by scanning electron microscope. Energy dispersive spectroscopy line scanning was carried out for evaluating the diffusion barrier properties of the Ni-P films. The electroless Ni-P layer worked well as a Cu diffusion barrier until 300 degrees C. However, Cu ions diffused into barrier layer when the annealing temperature increases over 400 degrees C. PMID:25971093

  10. Temporal changes in lithology and radiochemistry from the back-barrier environments along the Chandeleur Islands, Louisiana: March 2012-July 2013

    Science.gov (United States)

    Marot, Marci E.; Adams, C. Scott; Richwine, Kathryn A.; Smith, Christopher G.; Osterman, Lisa E.; Bernier, Julie C.

    2014-01-01

    Scientists from the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center conducted a time-series collection of shallow sediment cores from the back-barrier environments along the Chandeleur Islands, Louisiana from March 2012 through July 2013. The sampling efforts were part of a larger USGS study to evaluate effects on the geomorphology of the Chandeleur Islands following the construction of an artificial sand berm to reduce oil transport onto federally managed lands. The objective of this study was to evaluate the response of the back-barrier tidal and wetland environments to the berm. This report serves as an archive for sedimentological, radiochemical, and microbiological data derived from the sediment cores. Data are available for a time-series of four sampling periods: March 2012; July 2012; September 2012; and July 2013. Downloadable data are available as Excel spreadsheets and as JPEG files. Additional files include: ArcGIS shapefiles of the sampling sites, detailed results of sediment grain size analyses, and formal Federal Geographic Data Committee metadata.

  11. PALEOBATHYMETRIC INTERPRETATION OF THE FISH OTOLITHS FROM THE LOWER - MIDDLE QUATERNARY DEPOSITS OF KEPHALLONIA AND ZAKYNTHOS ISLANDS (IONIAN SEA, WESTERN GREECE

    Directory of Open Access Journals (Sweden)

    KONSTANTINA AGIADI

    2010-03-01

    Full Text Available Fish otoliths are herein used to estimate the depositional depth of the Early - Middle Pleistocene deposits at SE Zakynthos and SW Kephallonia Islands (Ionian Sea, Western Greece, through comparison with the modern bathymetric distributions of the identified fish taxa. These estimates provide a more detailed picture of the depth variations for the Gelasian - Ionian stage interval in the study areas. The Lower Pleistocene marine deposits of the Gerakas Formation (SE Zakynthos Island, Ionian Sea were deposited at average depths of 400-450 meters, with eustacy playing an important role in the depth variability, between 1.95-1.73 Ma. An uplifting episode, followed by subsidence takes place between 1.73-1.66 Ma, taking the area to 200-300 meters of depth, and then back to 400-500 meters. However, the area seems uplifted again to 200-400 meters later on in the Calabrian stage (1.25-0.97 Ma. Sedimentation of the Akrotiri deposits (NW Kephallonia Island, Ionian Sea, during the same chronostratigraphic interval, took place in a similar setting. At the Early Pleistocene (1.95-1.73 Ma this basin reached depths of 400-450 meters, with uplift and following subsidence taking place between 1.73-1.66 Ma. Overall, the application of fish otolith paleobathymetry in the study areas provide a detailed picture of the depth variations for the Early Quaternary interval and refine the currently hypothesized pattern of tectonic movements. 

  12. Bentonite deposits as a natural analogue to long-term barriers in a final repository of nuclear waste

    International Nuclear Information System (INIS)

    The geology of bentonite occurrences in Almeria (Spain) and Wyoming (USA) were studied in order to find suitable natural analogue to the longterm mechanical behaviour of the bentonite barrier in the final nuclear waste disposal. The study is based on literature review over both occurrence areas and on fieldwork observations from Almeria, Spain. The deposit areas differ from each other by age, deposition environment, exchangeable cation chemistry, alteration condition, occurrence and deformational features. One of the most important deformational feature in Almeria bentonites was the existence of Tertiary (Middle and Upper Miocene, 6-15.5 Ma old) bentonite intrusion inside/over younger Quaternary (Pleistocene Superior, 0.01-0.72 Ma old) sediments. This was a result of the confining pressure of overlying volcanic rocks and sediments and the high plasticity behaviour of bentonites. According to this observation, the pressure effect in final nuclear waste repositories requires further investigations. The bentonites in Wyoming have survived weathering and shearing without losing their expandability or other properties typical of smectite-rich materials. (orig.)

  13. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    International Nuclear Information System (INIS)

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y2O3-stabilized-ZrO2 (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs

  14. Thermal shock behavior of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhenhua, E-mail: zhxuciac@163.com [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Dai, Jianwei [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China); Niu, Jing [Shenyang Liming Aero-engine (Group) Corporation Ltd., Institute of Metallurgical Technology, Technical Center, Shengyang 110043 (China); Li, Na; Huang, Guanghong; He, Limin [Beijing Institute of Aeronautical Materials, Department 5, P.O. Box 81-5, Beijing 100095 (China)

    2014-12-25

    Highlights: • TBCs of (Ni, Pt)Al bond coat with grit blasting process and YSZ ceramic coating. • Grain boundary ridges are the sites for spallation damage initiation in TBCs. • Ridges removed, cavities formation appeared and the damage initiation deteriorated. • Damage initiation and progression at interface lead to a buckling failure. - Abstract: Thermal barrier coating systems (TBCs) including of chemical vapor deposited (Ni, Pt)Al bond coat with grit blasting process and electron beam physical vapor deposited Y{sub 2}O{sub 3}-stabilized-ZrO{sub 2} (YSZ) ceramic coating were investigated. The phase structures, surface and cross-sectional morphologies, thermal shock behaviors and residual stresses of the coatings were studied in detail. Grain boundary ridges still remain on the surface of bond coat prior to the deposition of the ceramic coating, which are shown to be the major sites for spallation damage initiation in TBCs. When these ridges are mostly removed, they appear some of cavities formation and then the damage initiation mode is deteriorated. Damage initiation and progression occurs at the bond coat to thermally grown oxide (TGO) interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface during cooling. The suppressed cavities formation, the removed ridges at the grain boundaries, the relative high TGO to bond coat interface toughness, the uniform growth behavior of TGO thickening and the lower of the residual stress are the primary factors for prolonging the lifetime of TBCs.

  15. Hot-dip aluminium deposit as a permeation barrier for MANET steel

    International Nuclear Information System (INIS)

    A hot-dip process developed in Forschungzentrum Karlsruhe (FzK), was used to produce a hydrogen permeation barrier on MANTA II steel. The hot-dip aluminising method produced an intermetallic layer of Al3Fe by immersing the specimens in molten aluminium at 1023 K for either 5 or 2 min. Subsequent heat treatment of the samples at 1023 K for 15 and 30 h, respectively, in air transformed the brittle Al3Fe layer into a softer phase and additionally produced alumina (Al2O3) on the surface. All processes were carried out at temperatures below 1053 K (above Ac1b=1053 K the austenitisation of MANTA II begins) in order to avoid the repetition of the whole MANTA II heat treatment (1348 K, 30 min fast cool; 1023 K, 2 h). The maximum obtained permeation reduction factor (PRF), compared with the uncoated MANTA II steel, has been obtained for the specimens oxidised for 15 h in air: yielding PRF's of 260 at 743 K and 1000 at 573 K. (orig.)

  16. Corrosion barriers for silver-based telescope mirrors: comparative study of plasma-enhanced atomic layer deposition and reactive evaporation of aluminum oxide

    Science.gov (United States)

    Fryauf, David M.; Phillips, Andrew C.; Kobayashi, Nobuhiko P.

    2015-10-01

    Astronomical telescopes continue to demand high-endurance high-reflectivity silver (Ag) mirrors that can withstand years of exposure in Earth-based observatory environments. We present promising results of improved Ag mirror robustness using plasma-enhanced atomic layer deposition (PEALD) of aluminum oxide (AlOx) as a top barrier layer. Transparent AlOx is suitable for many optical applications; therefore, it has been the initial material of choice for this study. Two coating recipes developed with electron beam ion-assisted deposition (e-beam IAD) of materials including yttrium fluoride, titanium nitride, oxides of yttrium, tantalum, and silicon are used to provide variations in basic Ag mirror structures to compare the endurance of reactive e-beam IAD barriers with PEALD barriers. Samples undergo high temperature/high humidity environmental testing in a controlled environment of 80% humidity at 80°C for 10 days. Environmental testing shows visible results suggesting that the PEALD AlOx barrier offers robust protection against chemical corrosion and moisture permeation. Ag mirror structures were further characterized by reflectivity/absorption before and after deposition of AlOx barriers.

  17. Limited denitrification in glacial deposit aquifers having thick unsaturated zones (Long Island, USA)

    Science.gov (United States)

    Young, Caitlin; Kroeger, Kevin D.; Hanson, Gilbert

    2013-01-01

    The goal of this study was to demonstrate how the extent of denitrification, which is indirectly related to dissolved organ carbon and directly related to oxygen concentrations, can also be linked to unsaturated-zone thickness, a mappable aquifer property. Groundwater from public supply and monitoring wells in Northport on Long Island, New York state (USA), were analyzed for denitrification reaction progress using dissolved N2/Ar concentrations by membrane inlet mass spectrometry. This technique allows for discernment of small amounts of excess N2, attributable to denitrification. Results show an average 15 % of total nitrogen in the system was denitrified, significantly lower than model predictions of 35 % denitrification. The minimal denitrification is due to low dissolved organic carbon (29.3–41.1 μmol L−1) and high dissolved oxygen concentrations (58–100 % oxygen saturation) in glacial sediments with minimal solid-phase electron donors to drive denitrification. A mechanism is proposed that combines two known processes for aquifer re-aeration in unconsolidated sands with thick (>10 m) unsaturated zones. First, advective flux provides 50 % freshening of pore space oxygen in the upper 2 m due to barometric pressure changes. Then, oxygen diffusion across the water-table boundary occurs due to high volumetric air content in the unsaturated-zone catchment area.

  18. Limited denitrification in glacial deposit aquifers having thick unsaturated zones (Long Island, USA)

    Science.gov (United States)

    Young, Caitlin; Kroeger, Kevin D.; Hanson, Gilbert

    2013-12-01

    The goal of this study was to demonstrate how the extent of denitrification, which is indirectly related to dissolved organ carbon and directly related to oxygen concentrations, can also be linked to unsaturated-zone thickness, a mappable aquifer property. Groundwater from public supply and monitoring wells in Northport on Long Island, New York state (USA), were analyzed for denitrification reaction progress using dissolved N2/Ar concentrations by membrane inlet mass spectrometry. This technique allows for discernment of small amounts of excess N2, attributable to denitrification. Results show an average 15 % of total nitrogen in the system was denitrified, significantly lower than model predictions of 35 % denitrification. The minimal denitrification is due to low dissolved organic carbon (29.3-41.1 μmol L-1) and high dissolved oxygen concentrations (58-100 % oxygen saturation) in glacial sediments with minimal solid-phase electron donors to drive denitrification. A mechanism is proposed that combines two known processes for aquifer re-aeration in unconsolidated sands with thick (>10 m) unsaturated zones. First, advective flux provides 50 % freshening of pore space oxygen in the upper 2 m due to barometric pressure changes. Then, oxygen diffusion across the water-table boundary occurs due to high volumetric air content in the unsaturated-zone catchment area.

  19. Salt-marsh erosion and restoration in relation to flood protection on the Wadden Sea barrier island Terschelling

    NARCIS (Netherlands)

    Loon-Steensma, van J.M.; Slim, P.A.; Decuyper, M.; Hu, Zhan

    2014-01-01

    This paper explores the impact of erosion and restoration measures on habitat development and on wave damping by a small salt marsh nestled alongside a dike on the Wadden island of Terschelling. The aim is to advance knowledge about the benefits and possible side-effects of salt-marsh restoration. A

  20. Simulation at high temperature of atomic deposition, islands coalescence, Ostwald and inverse Ostwald ripening with a general simple kinetic Monte Carlo code

    International Nuclear Information System (INIS)

    A three-dimensional kinetic Monte Carlo model (kMC) is proposed for the simulation of deposition and evolution of surface structures at elevated temperatures. The code includes deposition of one given type of atom and main thermally driven events such as surface diffusion, diffusion along island edges, detachment from islands, and movement of atoms on deposited surfaces. It can be used not only for simulating nucleation and growth of thin films but also for simulating time evolution of a given structure when annealed. It is a specific event kMC code, and the rates of the events are used as inputs. It allows the simulation of thousands of incident particles and the simulation of a system at high temperature without suffering large computational time. The code runs on a PC and is freely available. Results of modeling various situations like atomic deposition (Pd on SiO2), islands coalescence (Cu on Cu), Ostwald and inverse Ostwald ripening (Co/C and Co/SiO2) were tested against existing experimental and theoretical data and show a good agreement for all those cases.

  1. Non-linear, non-monotonic effect of nano-scale roughness on particle deposition in absence of an energy barrier: Experiments and modeling

    Science.gov (United States)

    Jin, Chao; Glawdel, Tomasz; Ren, Carolyn L.; Emelko, Monica B.

    2015-12-01

    Deposition of colloidal- and nano-scale particles on surfaces is critical to numerous natural and engineered environmental, health, and industrial applications ranging from drinking water treatment to semi-conductor manufacturing. Nano-scale surface roughness-induced hydrodynamic impacts on particle deposition were evaluated in the absence of an energy barrier to deposition in a parallel plate system. A non-linear, non-monotonic relationship between deposition surface roughness and particle deposition flux was observed and a critical roughness size associated with minimum deposition flux or “sag effect” was identified. This effect was more significant for nanoparticles (<1 μm) than for colloids and was numerically simulated using a Convective-Diffusion model and experimentally validated. Inclusion of flow field and hydrodynamic retardation effects explained particle deposition profiles better than when only the Derjaguin-Landau-Verwey-Overbeek (DLVO) force was considered. This work provides 1) a first comprehensive framework for describing the hydrodynamic impacts of nano-scale surface roughness on particle deposition by unifying hydrodynamic forces (using the most current approaches for describing flow field profiles and hydrodynamic retardation effects) with appropriately modified expressions for DLVO interaction energies, and gravity forces in one model and 2) a foundation for further describing the impacts of more complicated scales of deposition surface roughness on particle deposition.

  2. Deep repository - engineered barrier systems. Assessment of backfill materials and methods for deposition tunnels

    International Nuclear Information System (INIS)

    The main objectives of this report are to: (1) present density criteria considering deposition tunnels for the investigated backfill materials, (2) evaluate what densities can be achieved with the suggested backfill methods, (3) compare the density criteria to achievable densities, (4) based on this comparison evaluate the safety margin for the combinations of backfill materials and methods and, (5) make recommendations for further investigations and development work. The backfilling methods considered in this report are compaction of backfill material in situ in the tunnel and placement of pre-compacted blocks and pellets. The materials investigated in the second phase of the SKB-Posiva backfilling programme can be divided into three main categories: (1) Bentonite clays: two high-grade Na-bentonites from Wyoming (MX-80 and SPV200), one low-grade bentonite from Kutch (India Asha 2 0), and one high- and one low-grade Ca-bentonite from Milos (Deponite CA-N and Milos backfill). The highgrade bentonites are used in different bentonite-ballast mixtures. (2) Smectite-rich mixed-layer clays: one from Dnesice-Plzensko Jih (DPJ) located in the Czech Republic and one from Northern Germany (Friedland clay). (3) Mixtures of bentonite and ballast: Mixtures consisting of high-grade bentonite (30, 40 and 50 w-%) and crushed rock with different type of grain size distribution or sand. The general conclusion from the comparison between estimated achievable densities and the density criteria is that placing pre-compacted blocks of swelling clay or 50/50 mixture and pellets in the tunnel results in the highest safety margin. (orig.)

  3. Deep repository - engineered barrier systems. Assessment of backfill materials and methods for deposition tunnels

    International Nuclear Information System (INIS)

    The main objectives of this report are to: 1) present density criteria considering deposition tunnels for the investigated backfill materials, 2) evaluate what densities can be achieved with the suggested backfill methods, 3) compare the density criteria to achievable densities, 4) based on this comparison evaluate the safety margin for the combinations of backfill materials and methods and, 5) make recommendations for further investigations and development work. The backfilling methods considered in this report are compaction of backfill material in situ in the tunnel and placement of pre-compacted blocks and pellets. The materials investigated in the second phase of the SKB-Posiva backfilling project can be divided into three main categories: 1. Bentonite clays: two high-grade Na-bentonites from Wyoming (MX-80 and SPV200), one low-grade bentonite from Kutch (India Asha 230), and one high and one low-grade Ca-bentonite from Milos (Deponite CA-N and Milos backfill). The high-grade bentonites are used in different bentonite-ballast mixtures. 2. Smectite-rich mixed-layer clays: one from Dnesice-Plzensko Jih (DPJ) located in the Czech Republic and one from Northern Germany (Friedland clay). Mixtures of bentonite and ballast: Mixtures consisting of high-grade bentonite (0, 40 and 50 w-%) and crushed rock with different type of grain size distribution or sand. The relationships between dry densities and hydraulic conductivity, swelling pressure and compressibility in saturated state for these materials were investigated. Most of the tests were performed with a groundwater salinity of 3.5%. This salinity is comparable to sea water and can be expected to be at the high end of salinities occurring during the assessment period. The purpose of the investigations was to determine the dry densities required to meet the function indicator criteria. These densities are referred to as the density criteria. However throughout the assessment period a loss of material and thus

  4. Deep repository - engineered barrier systems. Assessment of backfill materials and methods for deposition tunnels

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarsson, David; Moren, Lena; Sellin, Patrik [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Keto, Paula [Saanio and Riekkola Oy, Helsinki (Finland)

    2006-09-15

    The main objectives of this report are to: 1) present density criteria considering deposition tunnels for the investigated backfill materials, 2) evaluate what densities can be achieved with the suggested backfill methods, 3) compare the density criteria to achievable densities, 4) based on this comparison evaluate the safety margin for the combinations of backfill materials and methods and, 5) make recommendations for further investigations and development work. The backfilling methods considered in this report are compaction of backfill material in situ in the tunnel and placement of pre-compacted blocks and pellets. The materials investigated in the second phase of the SKB-Posiva backfilling project can be divided into three main categories: 1. Bentonite clays: two high-grade Na-bentonites from Wyoming (MX-80 and SPV200), one low-grade bentonite from Kutch (India Asha 230), and one high and one low-grade Ca-bentonite from Milos (Deponite CA-N and Milos backfill). The high-grade bentonites are used in different bentonite-ballast mixtures. 2. Smectite-rich mixed-layer clays: one from Dnesice-Plzensko Jih (DPJ) located in the Czech Republic and one from Northern Germany (Friedland clay). Mixtures of bentonite and ballast: Mixtures consisting of high-grade bentonite (0, 40 and 50 w-%) and crushed rock with different type of grain size distribution or sand. The relationships between dry densities and hydraulic conductivity, swelling pressure and compressibility in saturated state for these materials were investigated. Most of the tests were performed with a groundwater salinity of 3.5%. This salinity is comparable to sea water and can be expected to be at the high end of salinities occurring during the assessment period. The purpose of the investigations was to determine the dry densities required to meet the function indicator criteria. These densities are referred to as the density criteria. However throughout the assessment period a loss of material and thus

  5. Impact of sea-level rise on cross-shore sediment transport on fetch-limited barrier reef island beaches under modal and cyclonic conditions.

    Science.gov (United States)

    Baldock, T E; Golshani, A; Atkinson, A; Shimamoto, T; Wu, S; Callaghan, D P; Mumby, P J

    2015-08-15

    A one-dimensional wave model is combined with an analytical sediment transport model to investigate the likely influence of sea-level rise on net cross-shore sediment transport on fetch-limited barrier reef and lagoon island beaches. The modelling considers if changes in the nearshore wave height and wave period in the lagoon induced by different water levels over the reef flat are likely to lead to net offshore or onshore movement of sediment. The results indicate that the effects of SLR on net sediment movement are highly variable and controlled by the bathymetry of the reef and lagoon. A significant range of reef-lagoon bathymetry, and notably shallow and narrow reefs, appears to lead hydrodynamic conditions and beaches that are likely to be stable or even accrete under SLR. Loss of reef structural complexity, particularly on the reef flat, increases the chance of sediment transport away from beaches and offshore. PMID:26093817

  6. Characteristics of WN{sub x}C{sub y} films deposited using remote plasma atomic layer deposition with ({sup Me}Cp)W(CO){sub 2}(NO) for Cu diffusion barrier

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyunjung; Park, Jingyu; Jeon, Heeyoung [Department of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Jang, Woochool; Jeon, Hyeongtag, E-mail: hjeon@hanyang.ac.kr [Department of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Yuh, Junhan, E-mail: junhan.yuh@gmail.com [Global Technology Center, POSCO, Seoul 135-777 (Korea, Republic of)

    2015-09-15

    Diffusion barrier characteristics of tungsten–nitride–carbide (WN{sub x}C{sub y}) thin films interposed between Cu and SiO{sub 2} layers were studied. The WN{sub x}C{sub y} films were deposited by remote plasma atomic layer deposition (RPALD) using a metal organic source, ({sup Me}Cp)W(CO){sub 2}(NO), and ammonia. Auger electron spectroscopy analysis indicated the WN{sub x}C{sub y} films consisted of tungsten, nitrogen, carbon, and oxygen. X-ray diffraction (XRD) analysis showed that the film deposited at 350 °C was nanocrystalline. The resistivity of WN{sub x}C{sub y} film deposited by RPALD was very low compared to that in previous research because of the lower nitrogen content and different crystal structures of the WN{sub x}C{sub y}. To verify the diffusion barrier characteristics of the WN{sub x}C{sub y} film, Cu films were deposited by physical vapor deposition after WN{sub x}C{sub y} film was formed by RPALD on Si substrate. The Cu/WN{sub x}C{sub y}/Si film stack was annealed in a vacuum by rapid thermal annealing at 500 °C. Cu diffusion through the barrier layer was verified by XRD. Stable film properties were observed up to 500 °C, confirming that WN{sub x}C{sub y} film is suitable as a Cu diffusion barrier in microelectronic circuits.

  7. Thermal barrier coating of lanthanum-zirconium-cerium composite oxide made by electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    Lanthanum-zirconium-cerium composite oxide (La2(Zr0.7Ce0.3)2O7, LZ7C3) as a candidate material for thermal barrier coatings (TBCs) was prepared by electron beam-physical vapor deposition (EB-PVD). The composition, crystal structure, thermophysical properties, surface and cross-sectional morphologies and cyclic oxidation behavior of the LZ7C3 coating were studied. The results indicated that LZ7C3 has a high phase stability between 298 K and 1573 K, and its linear thermal expansion coefficient (TEC) is similar to that of zirconia containing 8 wt% yttria (8YSZ). The thermal conductivity of LZ7C3 is 0.87 W m-1 K-1 at 1273 K, which is almost 60% lower than that of 8YSZ. The deviation of coating composition from the ingot can be overcome by the addition of excess CeO2 and ZrO2 during ingot preparation or by adjusting the process parameters. The failure of the LZ7C3 coating is mainly a result of the occurrence of micro-cracks inside ceramic topcoat, which cause the abnormal oxidation of bond coat.

  8. Quality Aspects of a Marine Aggregate Deposit off the SE Euboea Island, Greece, for its Exploitation - Preliminary Results

    Science.gov (United States)

    Anastasatou, Marianthi; Kapsimalis, Vasilios; Stamatakis, Michael; Tsoutsia, Antonia; Poulos, Serafeim; Rousakis, Grigoris; Karditsa, Aikaterini; Petrakis, Stelios; Aspiotis, Konstantinos; Papavlasopoulou, Nafsika; Stamatakis, Giorgos

    2015-04-01

    Aggregates are inert materials, such as terrestrial or marine sand and gravel, composed mainly of limestone, igneous rocks and sandstone. There is an international trend of increasing demand for aggregates during the last 30 years. Thus, marine aggregate (MA) demand has been displayed a remarkably increased due to limited terrestrial deposits and strict environmental issues related to their exploitation, induced by mining legislation. Regarding offshore MA extraction, important physical and biological seabed impacts that may persist long after the completion of the MA dredging, should be addressed, according to European directives, that deal with aspects such as restoration of the influenced subaqueous mining area. The present contribution focuses on the qualitative determination of the marine sediments on inner continental shelf of SE Euboea (central Aegean Sea), concerning primarily its silica content and secondarily the various environmental issues, in order to evaluate whether or not this subaqueous deposit fulfils the requirements for its exploitation. This MA deposit was found during the implementation of the research project THALES-MARE (MIS 375655) and after taking into consideration the presence of highly siliceous coastal lithology of the South Euboea Island. The area belongs to the Attico-Cycladic geotectonic zone, and especially in the Blueschist Unit, Styra and Ochi nappes. It consists mainly of metamorphosed clastic siliceous sedimentary and calcareous, mafic and felsic volcanic rocks and serpentinites. Sixteen representative samples were analysed out of 48 were collected in June 2014, during the scientific cruise of the M/V Aegaio (Hellenic Centre for Marine Research). The grain size analysis shows that seabed sediments are granulometrically classified mostly as sand, with contaminants of finer fractions and with the sand content often to be >90%. X-Ray Diffraction analysis revealed that the predominant crystalline phase is quartz (often >70

  9. Adjusting island density and morphology of the SrTiO3(110)-(4 × 1) surface: Pulsed laser deposition combined with scanning tunneling microscopy

    Science.gov (United States)

    Gerhold, Stefan; Riva, Michele; Yildiz, Bilge; Schmid, Michael; Diebold, Ulrike

    2016-09-01

    The first stages of homoepitaxial growth of the (4 × 1) reconstructed surface of SrTiO3(110) are probed by a combination of pulsed laser deposition (PLD) with in-situ reflection high energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). Considerations of interfacing high-pressure PLD growth with ultra-high-vacuum surface characterization methods are discussed, and the experimental setup and procedures are described in detail. The relation between RHEED intensity oscillations and ideal layer-by-layer growth is confirmed by analysis of STM images acquired after deposition of sub-monolayer amounts of SrTiO3. For a quantitative agreement between RHEED and STM results one has to take into account two interfaces: the steps at the circumference of islands, as well as the borders between two different reconstruction phases on the islands themselves. Analysis of STM images acquired after one single laser shot reveals an exponential decrease of the island density with increasing substrate temperature. This behavior is also directly visible from the temperature dependence of the relaxation times of the RHEED intensity. Moreover, the aspect ratio of islands changes considerably with temperature. The growth mode depends on the laser pulse repetition rate, and can be tuned from predominantly layer-by-layer to the step-flow growth regime.

  10. Antibacterial and barrier properties of oriented polymer films with ZnO thin films applied with atomic layer deposition at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Vähä-Nissi, Mika, E-mail: mika.vaha-nissi@vtt.fi [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Pitkänen, Marja; Salo, Erkki; Kenttä, Eija [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Tanskanen, Anne, E-mail: Anne.Tanskanen@aalto.fi [Aalto University, School of Chemical Technology, Department of Chemistry, Laboratory of Inorganic Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Sajavaara, Timo, E-mail: timo.sajavaara@jyu.fi [University of Jyväskylä, Department of Physics, P.O. Box 35, FI-40014 Jyväskylä (Finland); Putkonen, Matti; Sievänen, Jenni; Sneck, Asko; Rättö, Marjaana [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland); Karppinen, Maarit, E-mail: Maarit.Karppinen@aalto.fi [Aalto University, School of Chemical Technology, Department of Chemistry, Laboratory of Inorganic Chemistry, P.O. Box 16100, FI-00076 Aalto (Finland); Harlin, Ali [VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, VTT (Finland)

    2014-07-01

    Concerns on food safety, and need for high quality and extended shelf-life of packaged foods have promoted the development of antibacterial barrier packaging materials. Few articles have been available dealing with the barrier or antimicrobial properties of zinc oxide thin films deposited at low temperature with atomic layer deposition (ALD) onto commercial polymer films typically used for packaging purposes. The purpose of this paper was to study the properties of ZnO thin films compared to those of aluminum oxide. It was also possible to deposit ZnO thin films onto oriented polylactic acid and polypropylene films at relatively low temperatures using ozone instead of water as an oxidizing precursor for diethylzinc. Replacing water with ozone changed both the structure and the chemical composition of films deposited on silicon wafers. ZnO films deposited with ozone contained large grains covered and separated probably by a more amorphous and uniform layer. These thin films were also assumed to contain zinc salts of carboxylic acids. The barrier properties of a 25 nm ZnO thin film deposited with ozone at 100 °C were quite close to those obtained earlier with ALD Al{sub 2}O{sub 3} of similar apparent thickness on similar polymer films. ZnO thin films deposited at low temperature indicated migration of antibacterial agent, while direct contact between ZnO and Al{sub 2}O{sub 3} thin films and bacteria promoted antibacterial activity. - Highlights: • Thin films were grown from diethylzinc also with ozone instead of water at 70 and 100 °C. • ZnO films deposited with diethylzinc and ozone had different structures and chemistries. • Best barrier properties obtained with zinc oxide films close to those obtained with Al{sub 2}O{sub 3} • Ozone as oxygen source provided better barrier properties at 100 °C than water. • Both aluminum and zinc oxide thin films showed antimicrobial activity against E. coli.

  11. 75 FR 65005 - Intent To Prepare a Draft Supplemental Environmental Impact Statement (SEIS), Mississippi Barrier...

    Science.gov (United States)

    2010-10-21

    ... Statement (SEIS), Mississippi Barrier Island Restoration, Mississippi Coastal Improvements Program (MsCIP... comprehensive restoration of the Mississippi barrier islands. These actions are related to the consequences of... and wildlife, prevention of erosion, barrier island restoration, and other related water...

  12. Barrier properties of plastic films coated with an Al2O3 layer by roll-to-toll atomic layer deposition

    International Nuclear Information System (INIS)

    Thin (30–40 nm) and highly uniform Al2O3 coatings have been deposited at relatively low temperature of 100 °C onto various polymeric materials employing the atomic layer deposition (ALD) technique, both batch and roll-to-roll (R2R) mode. The applications for ALD have long been limited those feasible for batch processing. The work demonstrates that R2R ALD can deposit thin films with properties that are comparable to the film properties fabricated by in batch. This accelerates considerably the commercialization of many products, such as flexible, printed electronics, organic light-emitting diode lighting, third generation thin film photovoltaic devices, high energy density thin film batteries, smart textiles, organic sensors, organic/recyclable packaging materials, and flexible displays, to name a few. - Highlights: • Thin and uniform Al2O3 coatings have been deposited onto polymers materials. • Batch and roll-to-roll (R2R) atomic layer deposition (ALD) have been employed. • Deposition with either process improved the barrier properties. • Sensitivity of coated films to defects affects barrier obtained with R2R ALD

  13. Barrier properties of plastic films coated with an Al{sub 2}O{sub 3} layer by roll-to-toll atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Hirvikorpi, Terhi, E-mail: Terhi.Hirvikorpi@picosun.com [Picosun Oy, Tietotie 3, FI-02150 Espoo (Finland); Laine, Risto, E-mail: Risto.Laine@picosun.com [Picosun Oy, Tietotie 3, FI-02150 Espoo (Finland); Vähä-Nissi, Mika, E-mail: Mika.Vaha-Nissi@vtt.fi [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Kilpi, Väinö, E-mail: Vaino.Kilpi@picosun.com [Picosun Oy, Tietotie 3, FI-02150 Espoo (Finland); Salo, Erkki, E-mail: Erkki.Salo@vtt.fi [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Li, Wei-Min, E-mail: Wei-Min.Li@picosun.com [Picosun Oy, Tietotie 3, FI-02150 Espoo (Finland); Lindfors, Sven, E-mail: Sven.Lindfors@picosun.com [Picosun Oy, Tietotie 3, FI-02150 Espoo (Finland); Vartiainen, Jari, E-mail: Jari.Vartiainen@vtt.fi [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Kenttä, Eija, E-mail: Eija.Kentta@vtt.fi [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Nikkola, Juha, E-mail: Juha.Nikkola@vtt.fi [VTT Technical Research Centre of Finland, P.O. Box 1300, FI-33101 Tampere (Finland); Harlin, Ali, E-mail: Ali.Harlin@vtt.fi [VTT Technical Research Centre of Finland, Biologinkuja 7, Espoo, P.O. Box 1000, FI-02044 VTT (Finland); Kostamo, Juhana, E-mail: Juhana.Kostamo@picosun.com [Picosun Oy, Tietotie 3, FI-02150 Espoo (Finland)

    2014-01-01

    Thin (30–40 nm) and highly uniform Al{sub 2}O{sub 3} coatings have been deposited at relatively low temperature of 100 °C onto various polymeric materials employing the atomic layer deposition (ALD) technique, both batch and roll-to-roll (R2R) mode. The applications for ALD have long been limited those feasible for batch processing. The work demonstrates that R2R ALD can deposit thin films with properties that are comparable to the film properties fabricated by in batch. This accelerates considerably the commercialization of many products, such as flexible, printed electronics, organic light-emitting diode lighting, third generation thin film photovoltaic devices, high energy density thin film batteries, smart textiles, organic sensors, organic/recyclable packaging materials, and flexible displays, to name a few. - Highlights: • Thin and uniform Al{sub 2}O{sub 3} coatings have been deposited onto polymers materials. • Batch and roll-to-roll (R2R) atomic layer deposition (ALD) have been employed. • Deposition with either process improved the barrier properties. • Sensitivity of coated films to defects affects barrier obtained with R2R ALD.

  14. Influence of deposition conditions on the microstructure of Al-based coatings for applications as corrosion and anti-permeation barrier

    International Nuclear Information System (INIS)

    Highlights: • Electrochemical Al deposition is industrially relevant for barrier formation. • Al coatings have to be converted into protective layers by heat treatments. • Morphology of Al coatings made by ECX process depends on deposition parameters. • Heat treatment behavior depends on the morphology of the coating produced by ECX. • ECX is proven to produce layer sequences on Eurofer similar to HDA and ECA process. -- Abstract: Previous research revealed that the application of aluminum-based barriers is suitable to minimize corrosion rates of Eurofer steel in Pb–15.7Li and tritium-permeation from the liquid breeder into the cooling system (HCLL) in an envisaged future fusion reactor. Besides the former developed hot-dip-aluminization process (HDA), electrodeposition techniques based on water-free electrolytes, such as toluene-based electrolytes (ECA) and ionic liquids (ECX), showed promising results for the production of suitable aluminum layers. These processes allow electrodeposition of Al-layers on Eurofer steel with adjustable layer thicknesses, but a heat treatment procedure is needed afterwards to form the desired Fe–Al/Alumina scale. To investigate the deposition and treatment process in more detail, a new series of aluminum electroplating was performed by using the ECX process. The variation of deposition parameters (direct and pulsed current) showed clear impact on the morphology of deposited Al-layers. Heat treatments revealed that the formation of Fe–Al barriers is significantly influenced by the morphology of deposits, beyond other parameters like layer thickness. Presented metallographic and SEM/EDX analyses underline the occurred dependencies between deposition conditions and morphology and on the other hand Al-layer morphology and heat treatment behavior

  15. Influence of deposition conditions on the microstructure of Al-based coatings for applications as corrosion and anti-permeation barrier

    Energy Technology Data Exchange (ETDEWEB)

    Wulf, Sven-Erik, E-mail: sven-erik.wulf@kit.edu; Holstein, Nils; Krauss, Wolfgang; Konys, Jürgen

    2013-10-15

    Highlights: • Electrochemical Al deposition is industrially relevant for barrier formation. • Al coatings have to be converted into protective layers by heat treatments. • Morphology of Al coatings made by ECX process depends on deposition parameters. • Heat treatment behavior depends on the morphology of the coating produced by ECX. • ECX is proven to produce layer sequences on Eurofer similar to HDA and ECA process. -- Abstract: Previous research revealed that the application of aluminum-based barriers is suitable to minimize corrosion rates of Eurofer steel in Pb–15.7Li and tritium-permeation from the liquid breeder into the cooling system (HCLL) in an envisaged future fusion reactor. Besides the former developed hot-dip-aluminization process (HDA), electrodeposition techniques based on water-free electrolytes, such as toluene-based electrolytes (ECA) and ionic liquids (ECX), showed promising results for the production of suitable aluminum layers. These processes allow electrodeposition of Al-layers on Eurofer steel with adjustable layer thicknesses, but a heat treatment procedure is needed afterwards to form the desired Fe–Al/Alumina scale. To investigate the deposition and treatment process in more detail, a new series of aluminum electroplating was performed by using the ECX process. The variation of deposition parameters (direct and pulsed current) showed clear impact on the morphology of deposited Al-layers. Heat treatments revealed that the formation of Fe–Al barriers is significantly influenced by the morphology of deposits, beyond other parameters like layer thickness. Presented metallographic and SEM/EDX analyses underline the occurred dependencies between deposition conditions and morphology and on the other hand Al-layer morphology and heat treatment behavior.

  16. Coastal Barrier Resource Areas, Barrier Islands and Spits; s44gbb89; Barrier Beaches as defined by RI CRMC were barrier beaches as defined by RI CRMC were identified on quad maps and manually digitized from tablets, Published in 1989, 1:24000 (1in=2000ft) scale, State of Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Coastal Barrier Resource Areas dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 1989. It is...

  17. Effect of colony size and surrounding substrate on corals experiencing a mild bleaching event on Heron Island reef flat (southern Great Barrier Reef, Australia)

    Science.gov (United States)

    Ortiz, J. C.; Gomez-Cabrera, M. Del C.; Hoegh-Guldberg, O.

    2009-12-01

    In January-May 2006, Heron Island in the Great Barrier Reef experienced a mild bleaching event. The effect of colony size, morphology and surrounding substrate on the extent of bleaching was explored. In contrast with previous studies, colony size did not influence bleaching sensitivity, suggesting that there may be a threshold of light and temperature stress beyond which size plays a role. Also contrasting with previous studies, massive corals were more affected by bleaching than branching corals. Massive corals surrounded by sand were more affected than the ones surrounded by rubble or dead coral. It is hypothesized that light reflectance from sand increases stress levels experienced by the colonies. This effect is maximized in massive corals as opposed to branching corals that form dense thickets on Heron Island. These results emphasize the importance of the ecological dynamics of coral communities experiencing low, moderate and high levels of bleaching for the understanding of how coral communities may change under the stress of climate change.

  18. Effect of corona pre-treatment on the performance of gas barrier layers applied by atomic layer deposition onto polymer-coated paperboard

    International Nuclear Information System (INIS)

    The effect of corona pre-treatment on the performance of Al2O3 and SiO2 gas barrier layers applied by atomic layer deposition onto polymer-coated paperboards was studied. Both polyethylene and polylactide coated paperboards were corona treated prior to ALD. Corona treatment increased surface energies of the paperboard substrates, and this effect was still observed after several days. Al2O3 and SiO2 films were grown on top of the polymer coatings at temperature of 100 deg. C using the atomic layer deposition (ALD) technique. For SiO2 depositions a new precursor, bis(diethylamido) silane, was used. The positive effect of the corona pre-treatment on the barrier properties of the polymer-coated paperboards with the ALD-grown layers was more significant with polyethylene coated paperboard and with thin deposited layers (shorter ALD process). SiO2 performed similarly to Al2O3 with the PE coated board when it comes to the oxygen barrier, while the performance of SiO2 with the biopolymer-coated board was more moderate. The effect of corona pre-treatment was negligible or even negative with the biopolymer-coated board. The ALD film growth and the effect of corona treatment on different substrates require further investigation.

  19. Na-smectite s in the Cala de Tomate bentonite deposit (Spain): a natural analogue of the salinity effect on the bentonite barrier of a rad waste disposal

    Energy Technology Data Exchange (ETDEWEB)

    Perez del Villar, L.; Pelayo, M.; Fernandez, A.M.; Cozar, J.S. [CIEMAT - Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT/DIRE/CEAGP), Madrid (Spain); Delgado, A.; Reyes, E. [Ciencias de la Tierra y Quimica Ambiental Estacion Experimental del Zaidin Dpt., Granada (Spain); Fernandez-Soler, J.M. [Granada Univ., Dpt. de Mineralogia y Petrologia (Spain); Tsige, M. [Facultad de Ciencias Geologicas, Dpt. de Geodinamica, Madrid (Spain)

    2005-07-01

    Within the framework of the ENRESA programme for the assessment of the long-term behaviour of the bentonite-engineered barrier for a deep radwaste geological repository, analogue studies on several bentonite deposits are conducted at CIEMAT. Among these analogue studies, the thermal effect induced by volcanic intrusions on bentonite deposits is highlighted. In the Cabo de Gata volcanic region, there are several analogue scenarios where these studies have been performed, such as the Cala de Tomate bentonite deposit that was intruded by a pyroxene andesite volcanic dome. However, geological, mineralogical, physicochemical, geochemical and stable isotopic data obtained from the smectites do not allow to establish any analogy with the thermal effect expected on the bentonite-engineered barrier of a deep geological repository after burial. Thus, the bentonitisation processes took place after the intrusion of the dome, as a result of meteoric diagenesis intensively developed on faulting zone affecting the parent pyroclastic acid tuffs. This faulting process occurred after the dome intrusion. However, the physicochemical characteristics of these smectites, specially the exchangeable cations, allow to consider this bentonite deposit as a natural analogue of the saline effect on the clayey barrier. This analogy has been established because Na-smectites are present in this deposit and, up to our present knowledge, it is the first time that these smectites occur naturally in the Cabo de Gata-La Serrata de Nijar volcanic region. As a consequence, the main objectives of this work are: i) to characterise these smectites; ii) to establish their genesis and processes affecting them after their formation and iii) to identify the effects on the bentonite-engineered barrier should it were affected by a Na-rich saline waterfront. (authors)

  20. Geophysical imaging of the lacustrine sediments deposited in the La Calderilla Volcanic Caldera (Gran Canaria Island, Spain) for paleoclimate research

    Science.gov (United States)

    Himi, Mahjoub; Rodríguez-González, Alejandro; Criado, Constantino; Tapias, Josefina C.; Ravazzi, Cesare; Pérez-Torrado, Francisco; Casas, Albert

    2016-04-01

    The discovery of well-preserved maar structures is important not only for studying the eruptive activity and formation of volcanoes, but also for paleoclimate research, since laminated maar lake sediments may contain very detailed archives of climate and environmental history. Maars are a singular type of volcanic structure generated by explosive phreatomagmatic eruptions as a result of interaction between rising magma and groundwater. This kind of structures are characterised by circular craters, often filled with water and/or lacustrine sediments and surrounded by a ring of pyroclastic deposits.Recently a borehole was drilled at the bottom of La Calderilla volcanic complex which penetrated about 8.7 m in its sedimentary sequence and paleobotanical study has supplied the first evidence of paleoenvironmental evolution during the Holocene on the Gran Canaria Island. This survey, however, did not penetrate into the substrate because the total thickness of the sedimentary fill was unknown. Since the age of formation of La Calderilla volcanic complex based on K/Ar dating is about 85,000 years (Upper Pleistocene), the possibility of its sedimentary fill extends beyond of the Holocene is extremely attractive, since, for example, there are few paleoenvironmental data regarding how much the last glaciation that affected the Canary Islands. In these circumstances, the knowledge of the total thickness of the lacustrine sediments is crucial to design a deeper borehole in the next future. Therefore, the subsurface characterisation provided by geophysics is essential for determining thickness and geometry of the sedimentary filling. Multielectrode ERT method was used to obtain five 2-D resistivity cross-sections into La Calderilla volcanic caldera. An Iris Syscal Pro resistivity system with 48 electrodes connected to a 94 m long cable (2m electrode spacing) in Wenner-Schlumberger configuration for an investigation depth of about 20 m. Data quality (q 8000 Ω.m) that can be

  1. Energy barriers for interlayer diffusion in Pt/Pt(111) and Rh/Rh(111) homoepitaxy: small islands

    Czech Academy of Sciences Publication Activity Database

    Máca, František; Kotrla, Miroslav; Trushin, O. S.

    1999-01-01

    Roč. 49, č. 11 (1999), s. 1591-1596. ISSN 0011-4626. [Symposium on Surface Physics /8./. Třešť, 28.06.1999-02.07.1999] R&D Projects: GA MŠk OC P3.80 Institutional research plan: CEZ:AV0Z1010914 Keywords : molecular statics * energy barriers * Pt and Rh Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.328, year: 1999

  2. PROPERTIES OF THE ZRO2MGO/MGZRO3NICR/NICR TRIPLELAYER THERMAL BARRIER COATING DEPOSITED BY THE ATMOSPHERIC PLASMA SPRAY PROCESS

    OpenAIRE

    MRDAK MIHAILO R.

    2016-01-01

    This paper presents the results of the examinations of TBC ZrO2MgO / MgZrO3NiCr / NiCr thermal barrier layers deposited by the plasma spray process at the atmospheric pressure on substrates of Al alloys. In order to obtain the structural and mechanical properties of layers, which will provide a good heat and abrasion protection of the tail elevators of aircraft J-22 when firing "Lightning" and "Thunder" rockets, the deposition of three powder types was performed on 0.6 mm thick Al alloy subst...

  3. Evolution of microstructure during the growth of thermal barrier coatings by electron-beam physical vapor deposition

    Science.gov (United States)

    Terry, Scott Gregory

    2001-12-01

    The mechanisms responsible for the formation of porosity and crystallographic orientation (texture) in the microstructure of thermal barrier coatings (TBCs) grown by electron-beam physical vapor deposition (EB-PVD) are investigated. A matrix of 7 wt.% Y2O3-ZrO2 TBC specimens was generated by independently varying two processing parameters: substrate temperature (Ts) and pattern of vapor incidence. TBCs deposited on stationary substrates oriented normal to the vapor source yielded columnar microstructures possessing fiber textures. Growth directions changed from to + to + as Ts increased from 900-1100°C. Increasing the angle of vapor incidence to 45° favored biaxially aligned columnar growth in the direction, while rotating the substrates produced biaxially aligned columns. The texture orientation is correlated with the observed column tip morphologies by considering the growth directions defined by symmetric arrangements of {111} preferred growth planes about a column axis. The change in texture orientation with increasing Ts under normal incidence on stationary substrates is linked to changes in the mechanism of crystal growth. The pattern of vapor incidence on stationary oblique and rotated substrates has a stronger influence on texture than Ts. Here, the requirement that faces composing a column tip receive equal amounts of vapor flux determines the outcome of a competitive growth process yielding the observed biaxial orientations. The formation of porosity is in general attributed to shadowing of the incident vapor by geometric features of the TBC surface. These features are crystallographic in nature such that the formation of porosity is intimately tied to the crystallographic texture of the coating. Intercolumnar gaps are generated by the interaction between the pattern of vapor incidence and the column tip morphology, whereas the feather-like shape of the open intracolumnar porosity evolves from shadows cast by steps on the column tip faces. Closed

  4. Failure mechanisms of platinum aluminide bond coat/electron beam-physical vapor deposited thermal barrier coatings

    Science.gov (United States)

    Vaidyanathan, Krishnakumar

    Thermal barrier coatings (TBCs) allow operation of structural components, such as turbine blades and vanes in industrial and aircraft gas engines, at temperatures close to the substrate melting temperatures. They consist of four different layers; a high strength creep-resistant nickel-based superalloy substrate, an oxidation resistant bond coat (BC), a low thermal conductivity ceramic topcoat and a thermally grown oxide (TGO), that is predominantly alpha-Al 2O3, that forms between the BC and the TBC. Compressive stresses (3--5 GPa) that are generated in the thin TGO (0.25--8 mum) due to the mismatch in thermal coefficient of expansion between the TGO and BC play a critical role in the failure of these coatings. In this study, the failure mechanisms of a commercial yttria-stabilized zirconia (7YSZ) electron beam-physical vapor deposited (EB-PVD) coating on platinum aluminide (beta-(Ni,Pt)Al) bond coat have been identified. Two distinct mechanisms have been found responsible for the observed damage initiation and progression at the TGO/bond coat interface. The first mechanism leads to localized debonding at TGO/bond coat interface due to increased out-of-plane tensile stress, along bond coat features that manifest themselves as ridges. The second mechanism causes cavity formation at the TGO/bond coat interface, driven by cyclic plasticity of the bond coat. It has been found that the debonding at the TGO/bond coat interface due to the first mechanism is solely life determining. The final failure occurs by crack extension along either the TGO/bond coat interface or the TGO/YSZ interface or a combination of both, leading to large scale buckling. Based on these mechanisms, it is demonstrated that the bond coat grain size and the aspect ratio of the ridges have a profound influence on spallation lives of the coating. The removal of these ridges by fine polishing prior to TBC deposition led to a four-fold improvement in life. The failure mechanism identified for the

  5. A CFD-Based Study of the Feasibility of Adapting an Erosion Burner Rig for Examining the Effect of CMAS Deposition Corrosion on Environmental Barrier Coatings

    Science.gov (United States)

    Miller, Robert A.; Kuczmarski, Maria A.

    2015-01-01

    Thermodynamic and computational fluid dynamics modeling has been conducted to examine the feasibility of adapting the NASA-Glenn erosion burner rigs for use in studies of corrosion of environmental barrier coatings by the deposition of molten CMAS. The effect of burner temperature, Mach number, particle preheat, duct heating, particle size, and particle phase (crystalline vs. glass) were analyzed. Detailed strategies for achieving complete melting of CMAS particles were developed, thereby greatly improving the probability of future successful experimental outcomes.

  6. Gaseous transport and deposition of gold in magmatic fluid: evidence from the active Kudryavy volcano, Kurile Islands

    Science.gov (United States)

    Yudovskaya, Marina A.; Distler, Vadim V.; Chaplygin, Ilya V.; Mokhov, Andrew V.; Trubkin, Nikolai V.; Gorbacheva, Sonya A.

    2006-03-01

    The distribution of gold in high-temperature fumarole gases of the Kudryavy volcano (Kurile Islands) was measured for gas, gas condensate, natural fumarolic sublimates, and precipitates in silica tubes from vents with outlet temperatures ranging from 380 to 870°C. Gold abundance in condensates ranges from 0.3 to 2.4 ppb, which is significantly lower than the abundances of transition metals. Gold contents in zoned precipitates from silica tubes increase gradually with a decrease in temperature to a maximum of 8 ppm in the oxychloride zone at a temperature of approximately 300°C. Total Au content in moderate-temperature sulfide and oxychloride zones is mainly a result of Au inclusions in the abundant Fe-Cu and Zn sulfide minerals as determined by instrumental neutron activation analysis. Most Au occurs as a Cu-Au-Ag triple alloy. Single grains of native gold and binary Au-Ag alloys were also identified among sublimates, but aggregates and crystals of Cu-Au-Ag alloy were found in all fumarolic fields, both in silica tube precipitates and in natural fumarolic crusts. Although the Au triple alloy is homogeneous on the scale of microns and has a composition close to (Cu,Ni,Zn)3(Au,Ag)2, transmission electron microscopy (TEM) shows that these alloy solid solutions consist of monocrystal domains of Au-Ag, Au-Cu, and possibly Cu2O. Gold occurs in oxide assemblages due to the decomposition of its halogenide complexes under high-temperature conditions (650-870°C). In lower temperature zones (behavior is related to sulfur compounds whose evolution is strongly controlled by redox state. Other minerals that formed from gas transport and precipitation at Kudryavy volcano include garnet, aegirine, diopside, magnetite, anhydrite, molybdenite, multivalent molybdenum oxides (molybdite, tugarinovite, and ilsemannite), powellite, scheelite, wolframite, Na-K chlorides, pyrrhotite, wurtzite, greenockite, pyrite, galena, cubanite, rare native metals (including Fe, Cr, Mo, Sn, Ag, and

  7. Comparison of measurement of aerosol black carbon at Barrow, Alaska, and Wrangel Island, USSR: An approach to estimating the deposition of soot to snow and ice surfaces

    International Nuclear Information System (INIS)

    During late spring 1989 (and 1990, in planning), measurements of aerosol black carbon were, made on Wrangel Island in the Soviet Arctic to complement the routine measurements at the NOAA/GMCC Barrow Observatory of this combustion-derived pollutant. The results are compared during time intervals in which trajectories led from Barrow to Wrangel Island, with typical transit times of one day. The intervening surface is entirely frozen ocean, without land masses' topography to complicate air flow, nor any human habitation combustion sources. Aerosol black carbon is chemically unreactive, and so any losses in transit will be due to deposition onto the frozen ocean surface. This species is strongly optically absorbing, and a small aerosol deposition from the Arctic haze may reduce the surface albedo sufficiently to increase the absorption of solar radiation in spring and lead to premature, thawing. The authors discuss the possible effects of the deposition of soot from the Arctic haze onto high latitude snow and ice cover in terms of climate change

  8. The importance of dye chemistry and TiCl4 surface treatment in the behavior of Al2O3 recombination barrier layers deposited by atomic layer deposition in solid-state dye-sensitized solar cells

    KAUST Repository

    Brennan, Thomas P.

    2012-01-01

    Atomic layer deposition (ALD) was used to fabricate Al 2O 3 recombination barriers in solid-state dye-sensitized solar cells (ss-DSSCs) employing an organic hole transport material (HTM) for the first time. Al 2O 3 recombination barriers of varying thickness were incorporated into efficient ss-DSSCs utilizing the Z907 dye adsorbed onto a 2 μm-thick nanoporous TiO 2 active layer and the HTM spiro-OMeTAD. The impact of Al 2O 3 barriers was also studied in devices employing different dyes, with increased active layer thicknesses, and with substrates that did not undergo the TiCl 4 surface treatment. In all instances, electron lifetimes (as determined by transient photovoltage measurements) increased and dark current was suppressed after Al 2O 3 deposition. However, only when the TiCl 4 treatment was eliminated did device efficiency increase; in all other instances efficiency decreased due to a drop in short-circuit current. These results are attributed in the former case to the similar effects of Al 2O 3 ALD and the TiCl 4 surface treatment whereas the insulating properties of Al 2O 3 hinder charge injection and lead to current loss in TiCl 4-treated devices. The impact of Al 2O 3 barrier layers was unaffected by doubling the active layer thickness or using an alternative ruthenium dye, but a metal-free donor-π-acceptor dye exhibited a much smaller decrease in current due to its higher excited state energy. We develop a model employing prior research on Al 2O 3 growth and dye kinetics that successfully predicts the reduction in device current as a function of ALD cycles and is extendable to different dye-barrier systems. © This journal is the Owner Societies 2012.

  9. Assessing the impacts of sea-level rise and precipitation change on the surficial aquifer in the low-lying coastal alluvial plains and barrier islands, east-central Florida (USA)

    Science.gov (United States)

    Xiao, Han; Wang, Dingbao; Hagen, Scott C.; Medeiros, Stephen C.; Hall, Carlton R.

    2016-07-01

    A three-dimensional variable-density groundwater flow and salinity transport model is implemented using the SEAWAT code to quantify the spatial variation of water-table depth and salinity of the surficial aquifer in Merritt Island and Cape Canaveral Island in east-central Florida (USA) under steady-state 2010 hydrologic and hydrogeologic conditions. The developed model is referred to as the `reference' model and calibrated against field-measured groundwater levels and a map of land use and land cover. Then, five prediction/projection models are developed based on modification of the boundary conditions of the calibrated `reference' model to quantify climate change impacts under various scenarios of sea-level rise and precipitation change projected to 2050. Model results indicate that west Merritt Island will encounter lowland inundation and saltwater intrusion due to its low elevation and flat topography, while climate change impacts on Cape Canaveral Island and east Merritt Island are not significant. The SEAWAT models developed for this study are useful and effective tools for water resources management, land use planning, and climate-change adaptation decision-making in these and other low-lying coastal alluvial plains and barrier island systems.

  10. Renewable energy sources (RES) projects and their barriers on a regional scale: The case study of wind parks in the Dodecanese islands, Greece

    International Nuclear Information System (INIS)

    The increasing energy challenges faced, in particular, by isolated communities, such as insular communities, call for an integrated, flexible and easy-to-apply methodology aiming at providing a list of renewable energy sources) (RES) projects capable to reduce green house gas (GHG) emissions, satisfy future energy forecasts and reach the objectives of international/national energy directives and obligations, as, for example, the ones set by the Kyoto Protocol by 2010. The EU project EMERGENCE 2010 developed such a methodology that is implemented here in the case study of wind parks in the Dodecanese islands in Greece. The results obtained consist of a final list of financially viable RES wind projects, for which various barriers have been previously identified and assessed. The additional advantages of the proposed methodology is that besides providing as an end result a comprehensive list of RES projects adopted to specific criteria and regional priorities, it also allows space for involving - from early stages - the local community and stakeholders in the decision-making process (participatory planning); in this way, the EMERGENCE 2010 methodology may assist towards the RES promotion and public acceptance, the profitability of RES investments and the regional sustainable development.

  11. Numerical methods for finding periodic points in discrete maps. High order islands chains and noble barriers in a toroidal magnetic configuration

    International Nuclear Information System (INIS)

    We first remind usual physical and mathematical concepts involved in the dynamics of Hamiltonian systems, and namely in chaotic systems described by discrete 2D maps (representing the intersection points of toroidal magnetic lines in a poloidal plane in situations of incomplete magnetic chaos in Tokamaks). Finding the periodic points characterizing chains of magnetic islands is an essential step not only to determine the skeleton of the phase space picture, but also to determine the flux of magnetic lines across semi-permeable barriers like Cantori. We discuss here several computational methods used to determine periodic points in N dimensions, which amounts to solve a set of N nonlinear coupled equations: Newton method, minimization techniques, Laplace or steepest descend method, conjugated direction method and Fletcher-Reeves method. We have succeeded to improve this last method in an important way, without modifying its useful double-exponential convergence. This improved method has been tested and applied to finding periodic points of high order m in the 2D 'Tokamap' mapping, for values of m along rational chains of winding number n/m converging towards a noble value where a Cantorus exists. Such precise positions of periodic points have been used in the calculation of the flux across this Cantorus. (authors)

  12. Properties of plasma-enhanced atomic layer deposited TiC{sub x} films as a diffusion barrier for Cu metallization

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sang-Kyung; Kim, Hangil; Kim, Junbeam [School of Materials Science and Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Cheon, Taehoon [School of Materials Science and Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Center for Core Research Facilities, DaeguGyeongbuk Institute of Science & Technology, Daegu,South Korea (Korea, Republic of); Seo, Jong Hyun [Deptartment of Materials Engineering, Korea Aerospace University, 200-1 Hwajeon-dong, GoyangCity, Gyeonggi-do 412-791,South Korea (Korea, Republic of); Kim, Soo-Hyun, E-mail: soohyun@ynu.ac.kr [School of Materials Science and Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of)

    2015-09-01

    TiC{sub x} films were grown on thermally grown SiO{sub 2} substrate by atomic layer deposition (ALD) using tetrakis–neopentyl–titanium [Ti(CH{sub 2}C(CH{sub 3}){sub 3}){sub 4,} TiNp{sub 4}, Np = neopentyl, CH{sub 2}C(CH{sub 3}){sub 3}] and direct plasma of H{sub 2} as a reactant at the substrate temperature ranging from 200 to 400 °C. A narrow ALD temperature window from 275 to 300 °C was shown and a growth rate of 0.054 nm/cycle at the ALD temperature window was obtained. The ALD-TiC{sub x} films formed nanocrystalline structure with rock-salt phase that was confirmed by X-ray diffractometry and transmission electronic microscopy (TEM) analysis. Its resistivity was dependent on the microstructure features characterized by grain size and crystallinity as well as its density, which could be controlled by varying the deposition temperature. Resistivity of ~ 600 μΩ cm was obtained at the deposition temperature 300 °C where is in the ALD temperature window, by optimizing deposition condition. In this study, a performance of very thin ALD-TiC{sub x} (6 nm) as a diffusion barrier for Cu interconnects was evaluated. The results showed that the structure of Cu (80 nm)/ALD-TiC{sub x} (6 nm)/Si was stable after annealing at 600 °C for 30 min. Cross-sectional view TEM analysis combined with energy-dispersive spectroscopy revealed that ALD-TiC{sub x} diffusion barrier failed by the diffusion of Cu through the thin barrier layer into Si at 650 °C without interfacial reactions between the layers. - Highlights: • Atomic layer deposition (ALD) of TiC{sub x} using a metallorganic precursor. • The growth rate of 0.054 nm/cycle. • ALD temperature window between 275 and 300 °C. • Evaluation as a diffusion barrier against Cu.

  13. Positioning of the Precursor Gas Inlet in an Atmospheric Dielectric Barrier Reactor, and its Effect on the Quality of Deposited TiOx Thin Film Surface

    Directory of Open Access Journals (Sweden)

    Jan Píchal

    2013-01-01

    Full Text Available Thin film technology has become pervasive in many applications in recent years, but it remains difficult to select the best deposition technique. A further consideration is that, due to ecological demands, we are forced to search for environmentally benign methods. One such method might be the application of cold plasmas, and there has already been a rapid growth in studies of cold plasma techniques. Plasma technologies operating at atmospheric pressure have been attracting increasing attention. The easiest way to obtain low temperature plasma at atmospheric pressure seems to be through atmospheric dielectric barrier discharge (ADBD. We used the plasma enhanced chemical vapour deposition (PECVD method applying atmospheric dielectric barrier discharge (ADBD plasmafor TiOx thin films deposition, employing titanium isopropoxide (TTIP and oxygen as reactants, and argon as a working gas. ADBD was operated in filamentary mode. The films were deposited on glass. We studied the quality of the deposited TiOx thin film surface for various precursor gas inlet positions in the ADBD reactor. The best thin films quality was achieved when the precursor gases were brought close to the substrate surface directly through the inlet placed in one of the electrodes.High hydrophilicity of the samples was proved by contact angle tests (CA. The film morphology was tested by atomic force microscopy (AFM. The thickness of the thin films varied in the range of (80 ÷ 210 nm in dependence on the composition of the reactor atmosphere. XPS analyses indicate that composition of the films is more like the composition of TiOxCy.

  14. Effects of Post-SiH4 and Plasma Treatments on Chemical Vapor Deposited Cu Seeds with Chemical Vapor Deposited TiN Barrier in Porous Low Dielectric Constant and Cu Integration

    Science.gov (United States)

    Pyo, Sung Gyu; Park, Shangkyun; Park, Hansoo; Lee, Donghyun

    2011-07-01

    A Cu seed deposited by chemical vapor deposition (CVD) was integrated with a CVD TiN barrier and electroplated Cu in a double level metal interconnect scheme using a dual damascene process. The post-SiH4 treatment of CVD TiN inhibits agglomeration of thin Cu by improving the wettability of Cu seeds as well as reducing the TiN sheet resistance. Post-plasma treatment on CVD Cu seeds decreases impurities in CVD Cu and eliminates interface voids between the CVD Cu seed and electroplated Cu, improving the gap filling properties of electroplated Cu layers. Inherently poor adhesion of the CVD Cu layers between the Cu barrier metal and the electroplated Cu is overcome by CVD TiN post treatments and CVD Cu post-plasma treatment. Bias-thermal-stress (BTS) tests were performed to verify the effect of post-SiH4 treatment. The SiH4 treated CVD TiN barrier and CVD Cu seed show feasibility for 65-nm technology in terms of low via resistance and chain yields.

  15. Enhanced water vapor barrier properties for biopolymer films by polyelectrolyte multilayer and atomic layer deposited Al2O3 double-coating

    International Nuclear Information System (INIS)

    Commercial polylactide (PLA) films are coated with a thin (20 nm) non-toxic polyelectrolyte multilayer (PEM) film made from sodium alginate and chitosan and additionally with a 25-nm thick atomic layer deposited (ALD) Al2O3 layer. The double-coating of PEM + Al2O3 is found to significantly enhance the water vapor barrier properties of the PLA film. The improvement is essentially larger compared with the case the PLA film being just coated with an ALD-grown Al2O3 layer. The enhanced water vapor barrier characteristics of the PEM + Al2O3 double-coated PLA films are attributed to the increased hydrophobicity of the surface of these films.

  16. Enhanced water vapor barrier properties for biopolymer films by polyelectrolyte multilayer and atomic layer deposited Al 2 O 3 double-coating

    Science.gov (United States)

    Hirvikorpi, Terhi; Vähä-Nissi, Mika; Harlin, Ali; Salomäki, Mikko; Areva, Sami; Korhonen, Juuso T.; Karppinen, Maarit

    2011-09-01

    Commercial polylactide (PLA) films are coated with a thin (20 nm) non-toxic polyelectrolyte multilayer (PEM) film made from sodium alginate and chitosan and additionally with a 25-nm thick atomic layer deposited (ALD) Al 2O 3 layer. The double-coating of PEM + Al 2O 3 is found to significantly enhance the water vapor barrier properties of the PLA film. The improvement is essentially larger compared with the case the PLA film being just coated with an ALD-grown Al 2O 3 layer. The enhanced water vapor barrier characteristics of the PEM + Al 2O 3 double-coated PLA films are attributed to the increased hydrophobicity of the surface of these films.

  17. 10cct02_ss_v1_1m - Side scan sonar mosaic of Petit Bois Pass, Alabama, Mississippi Barrier Islands, March 2010

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In March of 2010, the U.S. Geological Survey (USGS) conducted geophysical surveys offshore of Petit Bois Island, Mississippi, and Dauphin Island, Alabama. These...

  18. 10cct02_sw_v2_50m - 50 meter interpolated bathymetric grid of Petit Bois Pass, Mississippi Barrier Islands, March 2010

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — In March of 2010, the U.S. Geological Survey (USGS) conducted geophysical surveys offshore of Petit Bois Island, Mississippi and Dauphin Island, Alabama. These...

  19. Dynamic Aeolian Deposition of Glacial Iron to the Open Ocean: 2 Years of Time-Series Observations from Middleton Island and the Copper River Delta

    Science.gov (United States)

    Schroth, A. W.; Crusius, J.; Campbell, R. W.; Gasso, S.; Moy, C. M.

    2013-12-01

    ron (Fe) is thought to be a limiting nutrient for phytoplankton in much of the north Pacific and the Gulf of Alaska (GoA) in particular. In the subarctic GoA, we have a limited knowledge of the role of glaciers in driving the supply of iron to marine ecosystem, and in particular, the role that dust derived from glacial flour plays in delivering bioavailable iron to the offshore ecosystems. In order to better understand glacial dust deposition in the GoA and its potential role in marine productivity, we combine time-series satellite, meteorological, and aerosol geochemical data from over 2 years of monitoring at Middleton Island and the Copper River Valley. Middleton Island is located on the edge of the continental shelf and is ideally positioned to monitor the flux of aerosol iron into adjacent Fe-limited waters, while the Copper River Delta and Valley are thought to be the source of much of the glacial dust that reaches Middleton. In fact, widespread dust events have been frequently observed (MODIS imagery) emanating from exposed floodplains within the heavily glacierized Copper River Valley. These events are most common in the fall, when high pressure in the AK interior and low pressure in the central GoA establish a pressure gradient that drives anomalously strong northerly winds capable of entraining the abundant glacial flour that is exposed under low water conditions in the Copper River floodplain. Here we present Fe geochemical data from continuous automated aerosol sampling on Middleton Island from 2011-2013. These time-series geochemical data, when coupled with MODIS and meteorological observations, present a remarkable opportunity to examine the drivers of these dust events and how inter-annual meteorological variability between dust seasons influences the annual flux of soluble Fe associated with these phenomena. The dust season of 2011-12, characterized by early and heavy snows and onshore winds, generated very little dust with minimal and infrequent

  20. The palynology and sedimentology of a coastal swamp at Awana, Great Barrier Island, New Zealand, from c. 7000 yr B.P. to present

    International Nuclear Information System (INIS)

    Pollen and sediment analysis of two Holocene cores from Awana, Great Barrier Island, shows that at 7000 calibrated yr B.P. the local swamp was an estuarine salt marsh dominated by Restionaceae. By c. 6000 yr B.P. the water table was lower, and a fresh water swamp (Gleichenia-Leptospermum) had replaced the salt marsh. Regional conifer-hardwood forest c. 7000 yr B.P. was initially co-dominated by Libocedrus and Dacrydium cupressinum. Libocedrus declined from c. 6000 yr B.P. During the period c. 6000-c. 2500 yr B.P., relatively stable environmental conditions ensued with little change in local or regional vegetation. Around 2500 yr B.P., the swamp surface became drier and was invaded by Dacrycarpus and Laurelia swamp forest. This forest was subsequently repeatedly disturbed (not by fire), indicating climatic change to drier and windier conditions. Ascarina lucida was periodically a major component of swamp forest. Disturbance is also recorded in the clastic (mineral) sediments, where beds of sand within finer-grained sediment and peat are interpreted as wind blown material derived from partly devegetated dunes to seaward. The presence of the Kaharoa Tephra allows the timing of major Polynesian deforestation at Awana to be reliably dated to c. 600 calibrated yr B.P. In contrast, we see no evidence in the clastic sediment record of disturbance at Awana since Kaharoa time. We attribute this to the maintenance of stable dunes by a herb/scrub cover despite nearby fires, or to the presence of scrub or forest buffering the swamp from ablating dunes. (author). 45 refs., 4 figs., 1 tab

  1. Thermal evolution of cobalt deposits on Co3O4(111): atomically dispersed cobalt, two-dimensional CoO islands, and metallic Co nanoparticles.

    Science.gov (United States)

    Mehl, S; Ferstl, P; Schuler, M; Toghan, A; Brummel, O; Hammer, L; Schneider, M A; Libuda, J

    2015-09-28

    Cobalt oxide nanomaterials show high activity in several catalytic reactions thereby offering the potential to replace noble metals in some applications. We have developed a well-defined model system for partially reduced cobalt oxide materials aiming at a molecular level understanding of cobalt-oxide-based catalysis. Starting from a well-ordered Co3O4(111) film on Ir(100), we modified the surface by deposition of metallic cobalt. Growth, structure, and adsorption properties of the cobalt-modified surface were investigated by scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), and infrared reflection absorption spectroscopy (IRAS) using CO as a probe molecule. The deposition of a submonolayer of cobalt at 300 K leads to the formation of atomically dispersed cobalt ions distorting the surface layer of the Co3O4 film. Upon annealing to 500 K the Co ions are incorporated into the surface layer forming ordered two-dimensional CoO islands on the Co3O4 grains. At 700 K, Co ions diffuse from the CoO islands into the bulk and the ordered Co3O4(111) surface is restored. Deposition of larger amounts of Co at 300 K leads to formation of metallic Co aggregates on the dispersed cobalt phase. The metallic particles sinter at 500 K and diffuse into the bulk at 700 K. Depending on the degree of bulk reduction, extended Co3O4 grains switch to the CoO(111) structure. All above structures show characteristic CO adsorption behavior and can therefore be identified by IR spectroscopy of adsorbed CO. PMID:26299410

  2. Potential of Cat-CVD deposited a-SiC:H as diffusion barrier layer on low-k HSQ films for ULSI

    International Nuclear Information System (INIS)

    Cu diffusion in the spin-on hydrogen silsesquioxane (HSQ) is a major obstacle in the low-k plus Cu technology for future ULSI devices. We have optimized the process conditions for the spin-on HSQ low-k films. Subsequent metallization with Al and Cu shows a higher leakage current for Cu contact. We have employed Cat-CVD to deposit a-SiC:H films of different thickness on HSQ and studied their effect on the leakage current with both Al and Cu electrodes. The films were deposited using silane (SiH4) and acetylene (C2H2) gases. Also, an independent determination of the dielectric constant of the Cat-CVD a-SiC:H layer has been carried out from the C-V measurements on Al/c-Si/a-SiC:H/Al structure. The electrical characteristics of the Al/c-Si/HSQ + a-SiC:H/Cu structures show almost two orders of magnitude lower leakage current compared with Al/c-Si/HSQ/Cu, indicating very good barrier properties of the a-SiC:H material. Moreover, the low dielectric value observed for a-SiC:H compares favorably to other diffusion barrier materials

  3. Structure and gas-barrier properties of amorphous hydrogenated carbon films deposited on inner walls of cylindrical polyethylene terephthalate by plasma-enhanced chemical vapor deposition

    Science.gov (United States)

    Li, Jing; Gong, Chunzhi; Tian, Xiubo; Yang, Shiqin; Fu, Ricky K. Y.; Chu, Paul K.

    2009-01-01

    The influence of radio-frequency (RF) power on the structure and gas permeation through amorphous hydrogenated carbon films deposited on cylindrical polyethylene terephthalate (PET) samples is investigated. The results show that a higher radio-frequency power leads to a smaller sp 3/sp 2 value but produces fewer defects with smaller size. The permeability of PET samples decreases significantly after a-C:H deposition and the RF only exerts a small influence. However, the coating uniformity, color, and wettability of the surface are affected by the RF power. A higher RF power results in to better uniformity and it may be attributed to the combination of the high-density plasma and sample heating.

  4. Structure and gas-barrier properties of amorphous hydrogenated carbon films deposited on inner walls of cylindrical polyethylene terephthalate by plasma-enhanced chemical vapor deposition

    International Nuclear Information System (INIS)

    The influence of radio-frequency (RF) power on the structure and gas permeation through amorphous hydrogenated carbon films deposited on cylindrical polyethylene terephthalate (PET) samples is investigated. The results show that a higher radio-frequency power leads to a smaller sp3/sp2 value but produces fewer defects with smaller size. The permeability of PET samples decreases significantly after a-C:H deposition and the RF only exerts a small influence. However, the coating uniformity, color, and wettability of the surface are affected by the RF power. A higher RF power results in to better uniformity and it may be attributed to the combination of the high-density plasma and sample heating.

  5. Improvement of adhesion and barrier properties of biomedical stainless steel by deposition of YSZ coatings using RF magnetron sputtering

    International Nuclear Information System (INIS)

    The AISI 316L stainless steel (SS) has been widely used in both artificial knee and hip joints in biomedical applications. In the present study, yttria stabilized zirconia (YSZ, ZrO2 + 8% Y2O3) films were deposited on AISI 316L SS by radio-frequency magnetron sputtering using different power densities (50–250 W) and deposition times (30–120 min) from a YSZ target. The crystallographic orientation and surface morphology were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of the surface modification on the corrosion performance of AISI 316L SS were evaluated in phosphate buffered saline (PBS) solution using an electrochemical test on both the virgin and coated samples. The YSZ coatings have a (111) preferred orientation during crystal growth along the c-axis for short deposition times (30–60 min), whereas a polycrystalline structure forms during deposition times from 90 to 120 min. The corrosion protective character of the YSZ coatings depends on the crystal size and film thickness. A significant increase in adhesion and corrosion resistance by at least a factor of 46 and a higher breakdown potential were obtained for the deposited coatings at 200 W (120 min). - Highlights: • Well-formed and protective YSZ coatings were achieved on AISI 316L SS substrates. • Films grown at high power and long deposition time have polycrystalline structures. • The crystal size varies from ∼ 5 to 30 nm as both power and deposition time increased. • The differences of corrosion resistance are attributed to internal film structure

  6. Improvement of adhesion and barrier properties of biomedical stainless steel by deposition of YSZ coatings using RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Hernández, Z.E. [Instituto Politécnico Nacional, CICATA-Altamira, Grupo CIAMS, Km 14.5, Carretera Tampico-Puerto Industrial Altamira, C. P. 89600, Altamira, Tamps, México (Mexico); CICATA—Altamira, IPN. Grupo CIAMS, Km 14.5, Carretera Tampico-Puerto Industrial Altamira, C. P. 89600, Altamira, Tamps, México (Mexico); Domínguez-Crespo, M.A., E-mail: mdominguezc@ipn.mx [Instituto Politécnico Nacional, CICATA-Altamira, Grupo CIAMS, Km 14.5, Carretera Tampico-Puerto Industrial Altamira, C. P. 89600, Altamira, Tamps, México (Mexico); Torres-Huerta, A.M.; Onofre-Bustamante, E. [Instituto Politécnico Nacional, CICATA-Altamira, Grupo CIAMS, Km 14.5, Carretera Tampico-Puerto Industrial Altamira, C. P. 89600, Altamira, Tamps, México (Mexico); Andraca Adame, J. [Instituto Politécnico Nacional, Centro de Nanociencias Micro y Nanotecnologías, Departamento de DRX, C. P. 07300, Mexico, DF, México (Mexico); Dorantes-Rosales, H. [Instituto Politécnico Nacional, ESIQIE, Departamento de Metalurgia, C. P. 07300 Mexico, DF, México (Mexico)

    2014-05-01

    The AISI 316L stainless steel (SS) has been widely used in both artificial knee and hip joints in biomedical applications. In the present study, yttria stabilized zirconia (YSZ, ZrO{sub 2} + 8% Y{sub 2}O{sub 3}) films were deposited on AISI 316L SS by radio-frequency magnetron sputtering using different power densities (50–250 W) and deposition times (30–120 min) from a YSZ target. The crystallographic orientation and surface morphology were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of the surface modification on the corrosion performance of AISI 316L SS were evaluated in phosphate buffered saline (PBS) solution using an electrochemical test on both the virgin and coated samples. The YSZ coatings have a (111) preferred orientation during crystal growth along the c-axis for short deposition times (30–60 min), whereas a polycrystalline structure forms during deposition times from 90 to 120 min. The corrosion protective character of the YSZ coatings depends on the crystal size and film thickness. A significant increase in adhesion and corrosion resistance by at least a factor of 46 and a higher breakdown potential were obtained for the deposited coatings at 200 W (120 min). - Highlights: • Well-formed and protective YSZ coatings were achieved on AISI 316L SS substrates. • Films grown at high power and long deposition time have polycrystalline structures. • The crystal size varies from ∼ 5 to 30 nm as both power and deposition time increased. • The differences of corrosion resistance are attributed to internal film structure.

  7. 200 kyrs of sediment deposition in the coastal lowlands of Bol'shoy Lyakhovsky - a record of deglaciation of the New Siberian Islands?

    Science.gov (United States)

    Schwamborn, Georg; Schirrmeister, Lutz; Wetterich, Sebastian; Fuchs, Margret; Meyer, Hanno; Siegert, Christine

    2016-04-01

    Bol'shoy Lyakhovsky, the southernmost island of the New Siberian Archipelago, holds the longest record of palaeoenvironmental history in the North Siberian Arctic. It stretches back to ~200 kyr before present. Next to palaeosols and floodplain deposits it includes prominent thermokarst deposits from the Last Interglacial and Yedoma (Ice Complex) sections from the Last Glacial. Yet, it is unknown, whether or not the depositional history of the area is affected by the deglaciation of the northern part of the New Siberian Archipelago. Potentially, it could give insights into the break-up of the proposed MIS 6 ice sheet located on the East Siberian Sea shelf. Polymodal particle size distributions in the sediment record suggest that more than one transport mechanism drove sediment accumulation from more than one source. From a cryo-sedimentological data set we focus on the mineral composition (63-125 μm fraction) to determine the provenance of the deposits and to identify possible changes of transport pathways. Complementary, we use pore ice hydrochemical data to track changes of the weathering solution preserved in permafrost. Presumably, the both complement each other, since the weathering products largely depend on the mineral composition. We conclude that the observed trends in the heavy mineral and pore ice chemical data of the frozen ground record reflect short-distance material transport from weathered bedrock to the depositional area. In this sense no portion of the 200 kyr record seems to be affected by the presumed MIS 6 ice sheet break-up, which at that time happened about 250 km north of the study site.

  8. Effects of Plasma Polymer Films and Their Deposition Powers on the Barrier Characteristics of the Multilayer Encapsulation for Organic Devices.

    Science.gov (United States)

    Kim, Hoonbae; Ban, Wonjin; Kwon, Sungruel; Yong, Sanghyun; Chae, Heeyeop; Jung, Donggeun

    2016-05-01

    Organic electronic devices (OEDs) are quite suitable for use in flexible devices due to their ruggedness and flexibility. A number of researchers have studied the use of OEDs on flexible substrates in transparent, flexible devices in the near future. However, water and oxygen can permeate through the flexible substrates and can reduce the longevity of OEDs made from organic materials, which are weak to moisture and oxygen. In order to prevent the degradation of the OEDs, researchers have applied an encapsulation layer to the flexible substrates. In this study, Al2O3/plasma polymer film/Al2O3 multi-layers were deposited on polyethylene-naphthalate substrates through a combination of atomic layer deposition and plasma-enhanced chemical vapor deposition (PECVD). The plasma polymer film, which is located between the Al2O3 films, is deposited via PECVD with the use of a tetrakis(trimethylsilyloxy)silane precursor. The power of the plasma deposition varied from 10 to 50 W. The hydrophobicity of the plasma polymer film surfaces was investigated by measuring the water contact angle. The chemical structures of the plasma polymer films were measured via ex-situ Fourier transform infrared analysis. The permeation curves of the various films were analyzed by performing a calcium (Ca)-test. PMID:27483936

  9. An underwater survey of bark deposits at Lookout Cove South, Kazakof Bay, Afognak Island during the fall of 1990

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the results of a study on bark deposits at the Afognak Native Corporations log transfer facility LTF. The purposes of this project were to...

  10. Nucleation and initial growth of atomic layer deposited titanium oxide determined by spectroscopic ellipsometry and the effect of pretreatment by surface barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, David C., E-mail: dccameron@mail.muni.cz [R& D Centre for Low-Cost Plasma and Nanotechnology Surface Modification, Masaryk University, Kotlářská 267/2, 611 37 Brno (Czech Republic); Krumpolec, Richard, E-mail: richard.krumpolec@fmph.uniba.sk [Department of Experimental Physics, Faculty of Mathematics, Physics and Informatics, Comenius University, Mlynská dolina, 842 4 Bratislava (Slovakia); Ivanova, Tatiana V., E-mail: tatiana.ivanova@lut.fi [ASTRaL team, Laboratory of Green Chemistry, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Homola, Tomáš, E-mail: tomas.homola@mail.muni.cz [R& D Centre for Low-Cost Plasma and Nanotechnology Surface Modification, Masaryk University, Kotlářská 267/2, 611 37 Brno (Czech Republic); Černák, Mirko, E-mail: cernak@physics.muni.cz [R& D Centre for Low-Cost Plasma and Nanotechnology Surface Modification, Masaryk University, Kotlářská 267/2, 611 37 Brno (Czech Republic)

    2015-08-01

    Highlights: • Spectroscopic ellipsometry shows initial nucleation and growth process in atomic layer deposited titanium dioxide. • Quantum confinement effects were used to measure evolution of crystallite size. • Crystallite surface density can be extracted from ellipsometric surface roughness data and crystallite size. • Pretreatment of silicon substrates by diffuse coplanar surface barrier discharge has only minor effects on titanium dioxide film nucleation and growth. - Abstract: This paper reports on the use of spectroscopic ellipsometry to characterise the initial nucleation stage of the atomic layer deposition of the anatase phase of titanium dioxide on silicon substrates. Careful control and analysis of the ellipsometric measurements enables the determination of the evolution of crystallite diameter and surface density in the nucleation stage before a continuous film is formed. This growth behaviour is in line with atomic force microscopy measurements of the crystallite size. The crystallite diameter is a linear function of the number of ALD cycles with a slope of approximately 1.7 Å cycle{sup −1} which is equivalent to a layer growth rate of 0.85 Å cycle{sup −1} consistent with a ripening process which increases the crystallite size while reducing their density. The crystallite density decreases from ∼3 × 10{sup 17} m{sup −3} in the initial nucleation stages to ∼3 × 10{sup 15} m{sup −3} before the film becomes continuous. The effect of exposing the substrate to a diffuse coplanar surface barrier discharge in an air atmosphere before deposition was measured and only small differences were found: the plasma treated samples were slightly rougher in the initial stages and required a greater number of cycles to form a continuous film (∼80) compared to the untreated films (∼50). A thicker layer of native oxide was found after plasma treatment.

  11. Multilayer moisture barrier

    Energy Technology Data Exchange (ETDEWEB)

    Pankow, Joel W; Jorgensen, Gary J; Terwilliger, Kent M; Glick, Stephen H; Isomaki, Nora; Harkonen, Kari; Turkulainen, Tommy

    2015-04-21

    A moisture barrier, device or product having a moisture barrier or a method of fabricating a moisture barrier having at least a polymer layer, and interfacial layer, and a barrier layer. The polymer layer may be fabricated from any suitable polymer including, but not limited to, fluoropolymers such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), or ethylene-tetrafluoroethylene (ETFE). The interfacial layer may be formed by atomic layer deposition (ALD). In embodiments featuring an ALD interfacial layer, the deposited interfacial substance may be, but is not limited to, Al.sub.2O.sub.3, AlSiO.sub.x, TiO.sub.2, and an Al.sub.2O.sub.3/TiO.sub.2 laminate. The barrier layer associated with the interfacial layer may be deposited by plasma enhanced chemical vapor deposition (PECVD). The barrier layer may be a SiO.sub.xN.sub.y film.

  12. Investigation of Al{sub 2}O{sub 3} barrier film properties made by atomic layer deposition onto fluorescent tris-(8-hydroxyquinoline) aluminium molecular films

    Energy Technology Data Exchange (ETDEWEB)

    Maindron, Tony; Aventurier, Bernard [LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Ghazouani, Ahlem; Jullien, Tony [LETI/DTSI/SDEP/Laboratoire Dépôt Equipe 2, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Rochat, Névine [LETI/DTSI/Service de Caractérisation des Matériaux et Composants, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Simon, Jean-Yves; Viasnoff, Emilie [LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France)

    2013-12-02

    Al{sub 2}O{sub 3} films have been deposited at 85 °C by atomic layer deposition onto single 100 nm thick tris-(8-hydroxyquinoline) aluminium (AlQ{sub 3}) films made onto silicon wafers. It has been found that a thick ALD-deposited Al{sub 2}O{sub 3} layer (> 11 nm) greatly prevents the photo-oxidation of AlQ{sub 3} films when exposed to continuous UV irradiation (350 mW/cm{sup 2}). Thin Al{sub 2}O{sub 3} thicknesses (< 11 nm) on the contrary yield lower barrier performances. Defects in the Al{sub 2}O{sub 3} layer have been easily observed as non-fluorescent AlQ{sub 3} singularities, or black spots, under UV light on the system Si/AlQ{sub 3}/Al{sub 2}O{sub 3} stored into laboratory conditions (22 °C/50% Relative Humidity (RH)) for long time scale (∼ 2000 h). Accelerated aging conditions in a climatic chamber (85 °C/85% RH) also allow faster visualization of the same defects (168 h). The black spot density grows upon time and the black spot density occurrence rates have been calculated to be 0.024 h{sup −1}·cm{sup −2} and 0.243 h{sup −1}·cm{sup −2} respectively for the two testing conditions. A detailed investigation of these defects did show that they cannot be ascribed to the presence of a detectable particle. In that sense they are presumably the consequence of the existence of nanometre-scaled defects which cannot be detected onto fresh samples. Interestingly, an additional overcoating of ebeam-deposited SiO{sub 2} onto the Si/AlQ{sub 3}/Al{sub 2}O{sub 3} sample helps to decrease drastically the black spot density occurrence rates down to 0.004 h{sup −1}·cm{sup −2} and 0.04 h{sup −1}·cm{sup −2} respectively for 22 °C/50% RH and 85 °C/85% RH testing conditions. These observations highlight the moisture sensitivity of low temperature ALD-deposited Al{sub 2}O{sub 3} films and confirm the general idea that a single Al{sub 2}O{sub 3} ALD film performs as an ultra-high barrier but needs to be overprotected from water condensation by an

  13. Self-forming Al oxide barrier for nanoscale Cu interconnects created by hybrid atomic layer deposition of Cu–Al alloy

    International Nuclear Information System (INIS)

    The authors synthesized a Cu–Al alloy by employing alternating atomic layer deposition (ALD) surface reactions using Cu and Al precursors, respectively. By alternating between these two ALD surface chemistries, the authors fabricated ALD Cu–Al alloy. Cu was deposited using bis(1-dimethylamino-2-methyl-2-butoxy) copper as a precursor and H2 plasma, while Al was deposited using trimethylaluminum as the precursor and H2 plasma. The Al atomic percent in the Cu–Al alloy films varied from 0 to 15.6 at. %. Transmission electron microscopy revealed that a uniform Al-based interlayer self-formed at the interface after annealing. To evaluate the barrier properties of the Al-based interlayer and adhesion between the Cu–Al alloy film and SiO2 dielectric, thermal stability and peel-off adhesion tests were performed, respectively. The Al-based interlayer showed similar thermal stability and adhesion to the reference Mn-based interlayer. Our results indicate that Cu–Al alloys formed by alternating ALD are suitable seed layer materials for Cu interconnects

  14. Highly sensitive hydrogen sensor based on graphite-InP or graphite-GaN Schottky barrier with electrophoretically deposited Pd nanoparticles

    Directory of Open Access Journals (Sweden)

    Zdansky Karel

    2011-01-01

    Full Text Available Abstract Depositions on surfaces of semiconductor wafers of InP and GaN were performed from isooctane colloid solutions of palladium (Pd nanoparticles (NPs in AOT reverse micelles. Pd NPs in evaporated colloid and in layers deposited electrophoretically were monitored by SEM. Diodes were prepared by making Schottky contacts with colloidal graphite on semiconductor surfaces previously deposited with Pd NPs and ohmic contacts on blank surfaces. Forward and reverse current-voltage characteristics of the diodes showed high rectification ratio and high Schottky barrier heights, giving evidence of very small Fermi level pinning. A large increase of current was observed after exposing diodes to flow of gas blend hydrogen in nitrogen. Current change ratio about 700,000 with 0.1% hydrogen blend was achieved, which is more than two orders-of-magnitude improvement over the best result reported previously. Hydrogen detection limit of the diodes was estimated at 1 ppm H2/N2. The diodes, besides this extremely high sensitivity, have been temporally stable and of inexpensive production. Relatively more expensive GaN diodes have potential for functionality at high temperatures.

  15. Isotopic composition of water-soluble nitrate in bulk atmospheric deposition at Dongsha Island: sources and implications of external N supply to the northern South China Sea

    Directory of Open Access Journals (Sweden)

    J.-Y. T. Yang

    2013-06-01

    Full Text Available Increased reactive nitrogen (Nr, NO3− + NH4+ + dissolved organic nitrogen emission from Asian continent poses profound threats on ecosystem safety from terrestrial throughout the ocean proper. To diagnose the sources of atmospheric Nr input and quantify its influence on marine nitrogen cycle of the South China Sea (SCS, an oligotrophic marginal sea adjacent to the emission hotspot China, we conducted measurements of dual isotopes of water-soluble nitrate (δ15NNO3 and δ18ONO3 and concentrations of major ions for bulk atmospheric deposition collected from Dongsha Island off south China. The δ15NNO3 and δ18ONO3 for bulk deposition ranged from −7.5‰ to +3.9‰ and ∼ +17‰ to +88‰, respectively. A relatively uniform low δ15NNO3 and high δ18ONO3 endmember were observed in winter. Non-sea-salt sulfate/calcium (nssSO42− and nssCa2+ peaked as the increasing nitrate depositional flux (one exception caused by typhoon, implying a pollution source of nitrate during high deposition. Meanwhile, the flux-weighted average of δ15NNO3 was −2.7± 2.3‰, resembling the isotopic signature of fossil fuel combustion in inland China. More variable dual isotopic values observed in July and September suggest relatively dynamics sources and conversion chemistry. During the period affected by the peripheral circumfluence of Typhoon Fanapi, a high nitrate deposition with uniform isotopic composition (δ15NNO3 of ~ −0.5‰ and δ18ONO3 of ∼ +19‰ was observed accompanying with low terrestrial constituents such as dust and pollutants (e.g. nssSO42− and nssCa2+. This high nitrate deposition was likely a natural endmember sourced from lightning. The summarized total atmospheric Nr deposition (AND is ∼ 50 mmol N m−2 yr−1. If without this additional AND fertilization, CO2 release (currently 460 ± 430 mmol C m−2 yr−1 from the SCS would be doubled. Our study demonstrates that AND may serve as an important external Nr supply to the SCS yet

  16. Isotopic composition of water-soluble nitrate in bulk atmospheric deposition at Dongsha Island: sources and implications of external N supply to the northern South China Sea

    Science.gov (United States)

    Yang, J.-Y. T.; Hsu, S.-C.; Dai, M.; Hsiao, S. S.-Y.; Kao, S.-J.

    2013-06-01

    Increased reactive nitrogen (Nr, NO3- + NH4+ + dissolved organic nitrogen) emission from Asian continent poses profound threats on ecosystem safety from terrestrial throughout the ocean proper. To diagnose the sources of atmospheric Nr input and quantify its influence on marine nitrogen cycle of the South China Sea (SCS), an oligotrophic marginal sea adjacent to the emission hotspot China, we conducted measurements of dual isotopes of water-soluble nitrate (δ15NNO3 and δ18ONO3) and concentrations of major ions for bulk atmospheric deposition collected from Dongsha Island off south China. The δ15NNO3 and δ18ONO3 for bulk deposition ranged from -7.5‰ to +3.9‰ and ˜ +17‰ to +88‰, respectively. A relatively uniform low δ15NNO3 and high δ18ONO3 endmember were observed in winter. Non-sea-salt sulfate/calcium (nssSO42- and nssCa2+) peaked as the increasing nitrate depositional flux (one exception caused by typhoon), implying a pollution source of nitrate during high deposition. Meanwhile, the flux-weighted average of δ15NNO3 was -2.7± 2.3‰, resembling the isotopic signature of fossil fuel combustion in inland China. More variable dual isotopic values observed in July and September suggest relatively dynamics sources and conversion chemistry. During the period affected by the peripheral circumfluence of Typhoon Fanapi, a high nitrate deposition with uniform isotopic composition (δ15NNO3 of ~ -0.5‰ and δ18ONO3 of ˜ +19‰) was observed accompanying with low terrestrial constituents such as dust and pollutants (e.g. nssSO42- and nssCa2+). This high nitrate deposition was likely a natural endmember sourced from lightning. The summarized total atmospheric Nr deposition (AND) is ˜ 50 mmol N m-2 yr-1. If without this additional AND fertilization, CO2 release (currently 460 ± 430 mmol C m-2 yr-1) from the SCS would be doubled. Our study demonstrates that AND may serve as an important external Nr supply to the SCS yet difficult to separate from N

  17. Double-ceramic-layer thermal barrier coatings based on La2(Zr0.7Ce0.3)2O7/La2Ce2O7 deposited by electron beam-physical vapor deposition

    International Nuclear Information System (INIS)

    Double-ceramic-layer (DCL) thermal barrier coatings (TBCs) of La2(Zr0.7Ce0.3)2O7 (LZ7C3) and La2Ce2O7 (LC) were deposited by electron beam-physical vapor deposition (EB-PVD). The composition, interdiffusion, surface and cross-sectional morphologies, cyclic oxidation behavior of DCL coating were studied. Energy dispersive spectroscopy and X-ray diffraction analyses indicate that both LZ7C3 and LC coatings are effectively fabricated by a single LZ7C3 ingot with properly controlling the deposition energy. The chemical compatibility of LC coating and thermally grown oxide (TGO) layer is unstable. LaAlO3 is formed due to the chemical reaction between LC and Al2O3 which is the main composition of TGO layer. Additionally, the thermal cycling behavior of DCL coating is influenced by the interdiffusion of Zr and Ce between LZ7C3 and LC coatings. The failure of DCL coating is a result of the sintering of LZ7C3 coating surface, the chemical incompatibility of LC coating and TGO layer and the abnormal oxidation of bond coat. Since no single material that has been studied so far satisfies all the requirements for high temperature applications, DCL coating is an important development direction of TBCs.

  18. Soil genesis on the island of Bermuda in the Quaternary: the importance of African dust transport and deposition

    Science.gov (United States)

    Muhs, Daniel R.; Budahn, James R.; Prospero, Joseph M.; Skipp, Gary; Herwitz, Stanley R.

    2012-01-01

    The origin of terra rossa, red or reddish-brown, clay-rich soils overlying high-purity carbonate substrates, has intrigued geologists and pedologists for decades. Terra rossa soils can form from accumulation of insoluble residues during dissolution of the host limestones, addition of volcanic ash, or addition of externally derived, long-range-transported (LRT) aeolian particles. We studied soils and paleosols on high-purity, carbonate aeolianites of Quaternary age on Bermuda, where terra rossa origins have been debated for more than a century. Potential soil parent materials on this island include sand-sized fragments of local volcanic bedrock, the LRT, fine-grained (N/YbN, GdN/YbN that can be distinguished from African dust and lower Mississippi River valley loess. Bermuda soils have Sc-Th-La, Cr-Ta-Nd, and Eu/Eu*, LaN/YbN, GdN/YbN that indicate derivation from a combination of LRT dust from Africa and local volcanic bedrock. Our results indicate that soils on islands in a very broad latitudinal belt of the western Atlantic margin have been influenced by African LRT dust inputs over much of the past –500 ka.

  19. Electrochemical behaviour of thin films deposited by plasma DBD torch on copper: An O2-diffusion barrier

    International Nuclear Information System (INIS)

    In the field of corrosion protection, the research of environmentally friendly coating processes is one of the research topics. The use of gaseous atmospheric plasma, especially dielectric barrier discharge (DBD) plasma is an interesting way to rapidly form a thin protective coating. The aim of this work is to characterize the electrochemical behaviour of a SiOxCyNz film, formed from different organosilicon precursors, in neutral corrosive environment on copper. The film morphology and composition were determined by transmission electron microscopy (TEM) observations and X-ray photoelectron spectroscopy (XPS). The electrochemical behaviour of the different treated copper was studied by stationary techniques and electrochemical impedance spectroscopy (EIS). With the same plasma parameter, the kind of organosilicon precursor determines the chemical stability of the coatings in water, then their protective properties. When the SiO2-like structure contains a low carbon level, the SiOxCyNz films present a good stability in water, and acts clearly as an O2 barrier membrane.

  20. Electrochemical behaviour of thin films deposited by plasma DBD torch on copper: An O{sub 2}-diffusion barrier

    Energy Technology Data Exchange (ETDEWEB)

    Barchiche, Chems-Eddine [Institut Jean Lamour - UMR CNRS 7198, Nancy Universite, BP 70239, Vandoeuvre-les-Nancy, 54506 (France); Duday, David; Choquet, Patrick; Migeon, Henri-Noel [Departement de Science et Analyse des Materiaux, Centre de Recherche Public Gabriel Lippmann, 41 rue du Brill, Belvaux, L-4422 (Luxembourg); Rocca, Emmanuel [Institut Jean Lamour - UMR CNRS 7198, Nancy Universite, BP 70239, Vandoeuvre-les-Nancy, 54506 (France)], E-mail: emmanuel.rocca@lcsm.uhp-nancy.fr

    2009-10-01

    In the field of corrosion protection, the research of environmentally friendly coating processes is one of the research topics. The use of gaseous atmospheric plasma, especially dielectric barrier discharge (DBD) plasma is an interesting way to rapidly form a thin protective coating. The aim of this work is to characterize the electrochemical behaviour of a SiO{sub x}C{sub y}N{sub z} film, formed from different organosilicon precursors, in neutral corrosive environment on copper. The film morphology and composition were determined by transmission electron microscopy (TEM) observations and X-ray photoelectron spectroscopy (XPS). The electrochemical behaviour of the different treated copper was studied by stationary techniques and electrochemical impedance spectroscopy (EIS). With the same plasma parameter, the kind of organosilicon precursor determines the chemical stability of the coatings in water, then their protective properties. When the SiO{sub 2}-like structure contains a low carbon level, the SiO{sub x}C{sub y}N{sub z} films present a good stability in water, and acts clearly as an O{sub 2} barrier membrane.

  1. Diffusion barrier properties of CVD thin tungsten and tantalum films, deposited on WC/Co metallo-ceramics

    International Nuclear Information System (INIS)

    Thin Tungsten (W) and Tantalum (Ta) films were deposited by pyrolysis from W(CO)6, WCl6 and TaCl5 precursors on WC/Co metallo ceramics substrates, containing 7-8 % and 11 - 12 % Co. Their properties to preventing a Co diffusion from the substrate to the surface coating have been studied by X-ray microprobe analysis, Auger electron spectroscopy and Direct Layer by Layer Spectral Analyses in Hallow Cathode method. (author)

  2. Modification of metal–InGaAs Schottky barrier behaviour by atomic layer deposition of ultra-thin Al2O3 interlayers

    International Nuclear Information System (INIS)

    The effect of inserting ultra-thin atomic layer deposited Al2O3 dielectric layers (1 nm and 2 nm thick) on the Schottky barrier behaviour for high (Pt) and low (Al) work function metals on n- and p-doped InGaAs substrates has been investigated. Rectifying behaviour was observed for the p-type substrates (both native oxide and sulphur passivated) for both the Al/p-InGaAs and Al/Al2O3/p-InGaAs contacts. The Pt contacts directly deposited on p-InGaAs displayed evidence of limited rectification which increased with Al2O3 interlayer thickness. Ohmic contacts were formed for both metals on n-InGaAs in the absence of an Al2O3 interlayer, regardless of surface passivation. However, limited rectifying behaviour was observed for both metals on the 2 nm Al2O3/n-InGaAs samples for the sulphur passivated InGaAs surface, indicating the importance of both surface passivation and the presence of an ultra-thin dielectric interlayer on the current–voltage characteristics displayed by these devices. - Highlights: • Investigation of the modification of metal–InGaAs Schottky barrier (SB) behaviour • Improving metal–InGaAs interface by sulphur passivation and ultrathin interlayer • Examine the effect of low work function and high work function metals on SB • Different SB behaviours observed on both n-type InGaAs and p-type InGaAs • Metal/n-InGaAs interface is more strongly pinned than the metal/p-InGaAs interface

  3. Modification of metal–InGaAs Schottky barrier behaviour by atomic layer deposition of ultra-thin Al{sub 2}O{sub 3} interlayers

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, Lalit [School of Physical Sciences, Dublin City University, Dublin 9 (Ireland); Gupta, Suman; Jaiswal, Piyush; Bhat, Navakanta; Shivashankar, S.A. [Centre for Nano Science and Engineering (CeNSE), Indian Institute of Science, Bangalore 560012 (India); Hughes, G. [School of Physical Sciences, Dublin City University, Dublin 9 (Ireland)

    2015-08-31

    The effect of inserting ultra-thin atomic layer deposited Al{sub 2}O{sub 3} dielectric layers (1 nm and 2 nm thick) on the Schottky barrier behaviour for high (Pt) and low (Al) work function metals on n- and p-doped InGaAs substrates has been investigated. Rectifying behaviour was observed for the p-type substrates (both native oxide and sulphur passivated) for both the Al/p-InGaAs and Al/Al{sub 2}O{sub 3}/p-InGaAs contacts. The Pt contacts directly deposited on p-InGaAs displayed evidence of limited rectification which increased with Al{sub 2}O{sub 3} interlayer thickness. Ohmic contacts were formed for both metals on n-InGaAs in the absence of an Al{sub 2}O{sub 3} interlayer, regardless of surface passivation. However, limited rectifying behaviour was observed for both metals on the 2 nm Al{sub 2}O{sub 3}/n-InGaAs samples for the sulphur passivated InGaAs surface, indicating the importance of both surface passivation and the presence of an ultra-thin dielectric interlayer on the current–voltage characteristics displayed by these devices. - Highlights: • Investigation of the modification of metal–InGaAs Schottky barrier (SB) behaviour • Improving metal–InGaAs interface by sulphur passivation and ultrathin interlayer • Examine the effect of low work function and high work function metals on SB • Different SB behaviours observed on both n-type InGaAs and p-type InGaAs • Metal/n-InGaAs interface is more strongly pinned than the metal/p-InGaAs interface.

  4. Isothermal Oxidation Behavior of VC and Columnar Structured Thermal Barrier Coatings Deposited by Suspension Plasma Spray Technology

    Science.gov (United States)

    Li, Xiaolong; Yang, Qi; Huang, Xiao; Tang, Zhaolin

    2015-08-01

    The effects of different thermal barrier coating (TBC) top coat structures and substrate alloys on the isothermal oxidation behaviors of TBC systems were investigated at 1080 °C in lab air. The tested TBC systems consisted of two nickel-based superalloy substrates (CMSX-4 and IN738LC), a platinum aluminide bond coat and two 8YSZ top coats (vertical cracked and columnar structured). Samples with IN738LC substrate demonstrated longer isothermal oxidation lives than the counterparts with CMSX-4 substrate. Outward refractory elemental diffusion in coating systems with CMSX-4 substrate and void formation at the interface between thermally grown oxide and bond coat was found to be responsible for the early failure of TBCs. Columnar structured YSZ top coat seemed to provide better protection of the bond coating and substrate, marginally delaying the failure of the both coating systems with IN738LC and CMSX-4.

  5. Occurrence of Fe–Mg-rich smectites and corrensite in the Morrón de Mateo bentonite deposit (Cabo de Gata region, Spain): A natural analogue of the bentonite barrier in a radwaste repository

    OpenAIRE

    Pelayo Bayón, Marta; García Romero, Emilia; Labajo Rodillana, Miguel A.; Pérez del Villar Guillén, L.

    2011-01-01

    The Morrón de Mateo bentonite deposit is being studied as a natural analogue of the thermal and geochemical effects on a bentonite barrier in a deep geological repository of high level radioactive wastes. This bentonite deposit and its host rocks were intruded by a rhyodacitic volcanic dome that induced a hydrothermal metasomatic process affecting the biocalcarenite beds close to the dome. In this work, the mineralogical and chemical features of the clay minerals of the hydrotherm...

  6. Metal-induced assembly of a semiconductor island lattice: Ge truncated pyramids on Au-patterned Si.

    Science.gov (United States)

    Robinson, J T; Liddle, J A; Minor, A; Radmilovic, V; Yi, D O; Greaney, P Alex; Long, K N; Chrzan, D C; Dubon, O D

    2005-10-01

    We report the two-dimensional alignment of semiconductor islands using rudimentary metal patterning to control nucleation and growth. In the Ge on Si system, a square array of submicron Au dots on the Si (001) surface induces the assembly of deposited Ge adatoms into an extensive island lattice. Remarkably, these highly ordered Ge islands form between the patterned Au dots and are characterized by a unique truncated pyramidal shape. A model based on patterned diffusion barriers explains the observed ordering and establishes general criteria for the broader applicability of such a directed assembly process to quantum dot ordering. PMID:16218739

  7. Short-term assessment of the sediment deposition rate and water conditions during a rainy season on La Azufrada coral reef, Gorgona Island, Colombia

    KAUST Repository

    Lozano-Cortés, Diego F

    2014-02-01

    One of the major stresses on corals is the settlement of suspended sediment on their surfaces. This leads to the blocking of light, the covering of the coral mucus surface and an increased risk of disease. For this reason sediment deposition on a reef is considered a highly important variable in coral reef studies. With the use of sediment traps and oceanographic sensors, the sediment deposition rate and water conditions during a rainy season (April-May 2009) on a Tropical Eastern Pacific coral reef (La Azufrada) at Gorgona Island in Colombia were investigated. To quantify sediment deposition, sediment traps were established in nine stations along the coral reef (three stations per reef zone: backreef, flat and slope). To minimize disturbance by aquatic organisms in the sediment traps these were filled with hypersaline borax-buffered 10% formaline solution before their deployment; animals found in the filter contents were fixed and stored in a 4% formalin solution, frozen and identified in the laboratory. To determine the water conditions, discrete samples of water from 1 m and 10 m depths were collected using a Niskin bottle. Oceanographic variables (temperature, salinity and dissolved oxygen) as well as turbidity, chlorophyll and nutrient concentration (nitrite, nitrate and phosphorus) were measured in the samples from both depths. Vertical records of temperature and salinity were carried out with a Seabird-19 CTD nearest to La Azufrada and water transparency was measured using a Secchi disk. We found a mean trap collection rate of 23.30±4.34gm-2d-1 and did not detect a significant difference in the trap collection rate among reef zones. The mean temperature and salinity in the coral reef depth zone (0-10m layer) were 26.98±0.19°C and 32.60±0.52, respectively. Fourteen taxonomic groups of invertebrates were detected inside the sediment traps with bivalves and copepods being the most abundant and frequen. The findings presented here constitute the first report

  8. The Porgera gold deposit, Papua, New Guinea, 1: association with alkalic magmatism in a continent-island-arc collision zone

    International Nuclear Information System (INIS)

    The meso thermal to epithermal Porgera gold deposit is spatially and temporally associated with shallow level (≤ 2 km emplacement depth) stocks and dykes of the Porgera Intrusive Complex (PIC). Gold mineralization immediately followed emplacement of the PIC, and is dated between 5 and 6 Ma ago. The Porgera intrusive suite is comprised of fine- to medium-grained, porphyritic to euhedral granular, volatile-rich, sodic alkali basalts/gabbros, hawaiites, and mugearites (TAS chemical classification scheme). The rocks display chemical and isotopic characteristics similar to those of intra plate alkalic basalts, but their unusually high volatile contents result in stabilization of hornblende as a phenocryst and intergranular phase in more evolved rock types. The observed order of cotectic crystallization is olivine - clinopyroxene - hornblende -plagioclase, with ubiquitous spinel (chromite/magnetite) and fluor-apatite. (author)

  9. Regional background aerosols over the Balearic Islands over the last 3 years: ground-based concentrations, atmospheric deposition and sources

    Science.gov (United States)

    Cerro, Jose Carlos; Pey, Jorge; Bujosa, Carles; Caballero, Sandra; Alastuey, Andres; Sicard, Michael; Artiñano, Begoña; Querol, Xavier

    2013-04-01

    In the context of the ChArMEx (The Chemistry-Aerosol Mediterranean Experiment, https://charmex.lsce.ipsl.fr) initiative, a 3-year study over a regional background environment (Can Llompart, CLP) in Mallorca has been conducted. Ground-based PM mass concentrations, gaseous pollutants and meteorological parameters were continuously registered from 2010 to 2012. Since the beginning of the campaign, PM10 daily samples for chemical determinations were obtained every 4 days, and dry and wet deposition samples were collected every week. Moreover, additional instruments (condensation particle counter, multi-angle absorption photometer, airpointer, sequential high and low volume samplers) were deployed during intensive filed campaigns in 2011 and 2012, as well as the sampling frequency was intensified. In the laboratory, PM samples were analyzed for inorganic compounds, and organic and elemental carbon following different approaches. In addition, n-alkanes, iso-alkanes, antiso-alkanes, levoglucosan, alkanoic acids and cholesterol were determined by GC-MS chromatography in a selection of 30 samples. Mean PM10, PM2.5 and PM1 concentrations in the period 2010-2012 reached 17, 11, and 8 µg/m3 respectively. Mass concentrations displayed marked seasonal trends, with much higher background levels in summer due to stagnant conditions over the western Mediterranean and increased frequency of Saharan dust events. Likewise, diverse-intensity peaks of coarse PM due to African dust inputs were observed along the year. On average, African dust in PM10 accounted for 1.0-1.5 µg/m3. Sporadic pollution events, characterized by most of the particles in the fine mode, were related to the transport of anthropogenic polluted air masses from central and eastern Europe. Wet and dry atmospheric deposition samples are being analyzed to quantify the deposition fluxes for different soluble and insoluble compounds. On average, PM10 composition is made up of organic matter (23%), mineral components (17

  10. Solomon Islands Tsunami, One Year Later

    Science.gov (United States)

    McAdoo, Brian G.; Fritz, Hermann; Jackson, Kelly L.; Kalligeris, Nikos; Kruger, Jens; Bonte-Grapentin, Michael; Moore, Andrew L.; Rafiau, Wilson B.; Billy, Douglas; Tiano, Braddley

    2008-04-01

    The geologic and economic effects of the 2 April 2007 Solomon Islands earthquake and tsunami are distinctly visible a little more than a year after the event. Coral reef colonies that were sheared off and uplifted are slowly recovering, and many new earthquake-triggered landslides remain mobile. Large volumes of sediment created by the earthquake and mobilized by the tsunami have been flushed from the lagoons between the reef and shoreline into deeper water, although significant quantities remain on land. Sediment from the lagoons covers piles of shattered coral that the tsunami moved from the lagoons to the base of channels in the barrier reef. These shattered corals have a higher chance of preservation as paleotsunami deposits than the material deposited on land.

  11. Selective growth of Pb islands on graphene/SiC buffer layers

    International Nuclear Information System (INIS)

    Graphene is fabricated by thermal decomposition of silicon carbide (SiC) and Pb islands are deposited by Pb flux in molecular beam epitaxy chamber. It is found that graphene domains and SiC buffer layer coexist. Selective growth of Pb islands on SiC buffer layer rather than on graphene domains is observed. It can be ascribed to the higher adsorption energy of Pb atoms on the 6√(3) reconstruction of SiC. However, once Pb islands nucleate on graphene domains, they will grow very large owing to the lower diffusion barrier of Pb atoms on graphene. The results are consistent with first-principle calculations. Since Pb atoms on graphene are nearly free-standing, Pb islands grow in even-number mode

  12. Escape of unradiogenic osmium during sub-aerial lava degassing: Evidence from fumarolic deposits, Piton de la Fournaise, Réunion Island

    Science.gov (United States)

    Gannoun, Abdelmouhcine; Vlastélic, Ivan; Schiano, Pierre

    2015-10-01

    This study presents new Re-Os isotope and elemental data in gas condensates and corresponding lavas in order to examine the geochemical behavior of these two elements during magma degassing at Piton de la Fournaise, Réunion Island. Gas sublimates formed between 2007 and 2011 at temperature ranging from 400 to ca. 100 °C include Na-K sulfate (aphthitalite), Na sulfate (thenardite), Ca-Cu sulfate (e.g. gypsum), Ca-Mg-Al-Fe fluoride (e.g. ralstonite) and native sulfur. The high temperature deposits show trace element typical of volcanic gas with high enrichment in Re (24 to 79 ppb), almost two order of magnitude higher than the corresponding lavas but with Os abundances similar to those of the lavas (14-132 ppt). In contrast the Os contents of the low temperature fluoride deposits (13-77 ppb) are higher than any of the other condensates. The fluorides are also enriched in Re, albeit to lesser extent than Os (2.9-15.3 ppb). Based on high-temperature samples, the fluid/melt partition coefficients estimated for Re and Os are 100 ± 80 and 1 ± 2, respectively. Considering 1% of fluid loss, these partition coefficients translate into emanation coefficients of 0.50 (0.17-0.65) for Re and 0.01 (0-0.03) for Os. These results indicate that Re, unlike Os, is highly volatile at Piton de la Fournaise. Osmium isotopic compositions of samples collected at medium and low temperature (Piton de la Fournaise (i.e. 0.130-0.137). However the highest temperature condensates (Na-K sulfates with T of 384-400°C) yield lower 187Os/188Os ratios (i.e. 0.124-0.129) within the field of mantle signal. Such unradiogenic compositions are best explained if old mantle sulfides occur in lavas and contribute to volcanic gases. Within the general frame of osmium mantle geochemistry, loss of unradiogenic Os during magmas degassing could help to explain osmium isotope disequilibrium between lavas and melting residues.

  13. STM imaging of electrically floating islands

    Science.gov (United States)

    Realpe, H.; Shamir, N.; Mintz, M. H.; Manassen, Y.

    2006-07-01

    Appearances and disappearances of Gd islands grown on top of a W(1 1 0) substrate were observed in time scales of hours after exposing the surface to a few Langmuirs of hydrogen. The phenomenon is presented and explained in terms of (temporary) creation of electrically floating islands, due to electrical decoupling of the island and substrate by the hydrogen that diffuses into the island/substrate interface. The disappearance of such an island is explained by forming a double barrier junction consisting of two tunneling barriers in series, causing, by charging, the potential of the island to become equal to that of the tip. The island then becomes "invisible" and the tip follows the corrugation of the surface under the substrate. The reappearance follows hydrogen mobility that retains the electrical conductivity of the island-substrate interface.

  14. Study of three dimensional germanium islands and ultrathin Si{sub x}Ge{sub 1-x} films grown by chemical vapour deposition on Si(111)-(7 x 7)

    Energy Technology Data Exchange (ETDEWEB)

    Gopalakrishnan, Selvi

    2005-07-15

    This work probed at the atomic level, processes that occur during the Ge three dimensional island formation and on ultrathin Si{sub x}Ge{sub 1-x} epitaxial growth by chemical vapour deposition on the Si(111)-(7 x 7) substrate with the aid of surface probe techniques such as STM and AFM, XPS, as well as TEM imaging of any 3D island formation. This work could essentially be divided into two parts. The first part studied the growth of the strained Ge on Si system with emphasis on the characterisation of the CVD grown three dimensional germanium islands on a standard Si(111)-(7 x 7) substrate as well as on a surface modified Si(111)-(7 x 7) substrate. The characterisation was carried out using a combination of techniques. XPS was used to calculate the effective coverages of deposited germanium, the STM was used to image the top most layers whenever possible and AFM, cross-sectional TEM and HRTEM to image the three dimensional islands. The possible causes of the surface modification were also examined. In the second part of this work the growth morphologies ultrathin Si{sub x}Ge{sub 1-x} layers grown on the Si(111)-(7 x 7) substrate at 750 K where the hydrogen desorption rate from the Si(111) surface is low and at 850 K which was the temperature at which the rate of hydrogen desorption from the Si(111) surface was a maximum were investigated. In addition modelling of ultrathin layer growth was carried out using two existing growth models. (orig.)

  15. Tectonic control on the stratigraphic framework of Late Pleistocene and Holocene deposits in Marajó Island, State of Pará, eastern Amazonia

    Directory of Open Access Journals (Sweden)

    Dilce F. Rossetti

    2010-06-01

    Full Text Available The traditional view that the Brazilian Amazonia is located in a tectonically stable area since the Cretaceous is changing in front of the increasing documentation of fault reactivations even during the Holocene. How the sedimentary record has responded to these events is an issue that remains to be approached with basis on field data. This work focuses on the stratigraphic correlation of late Quaternary deposits from eastern Marajó Island, with the goal of demonstrating the role of fault reactivation on the origin and preservation of these deposits. Despite the location in a stable platform of a continental passive margin, three studied stratigraphic units display significant vertical offsets that define two depocenters that are better explained through tectonic displacements. This interpretation is reinforced by several morphostructural features related to faults that occur between the studied drills. Without the influence of tectonics, sediment preservation in this characteristically low-lying terrain would have been negligible. The results of the present work motivate to look for other tectonically-influenced areas in Amazonia, which similarly might have acted as sites for sediment accommodation during the late Quaternary. These sedimentary records have great potential to be the source of valuable information for reconstructing Quaternary geological events in Northern Brazil.A visão tradicional de que a Amazônia brasileira localiza-se em ma área tectonicamente estável desde o Cretáceo está mudando perante a crescente documentação de reativações de falha, até mesmo durante o Holoceno. Como o registro sedimentar respondeu a esses eventos é um tema que permanece por ser abordado com base em dados de campo. Este trabalho enfatiza a correlação estratigráfica de depósitos quaternários tardios no leste da Ilha do Marajó, com o objetivo de demonstrar a importância de reativações de falha na origem e preservação desses dep

  16. Quantifying water flow within aquatic ecosystems using load cell sensors: a profile of currents experienced by coral reef organisms around Lizard Island, Great Barrier Reef, Australia.

    Directory of Open Access Journals (Sweden)

    Jacob L Johansen

    Full Text Available Current velocity in aquatic environments has major implications for the diversity, abundance and ecology of aquatic organisms, but quantifying these currents has proven difficult. This study utilises a simple and inexpensive instrument (500 cms⁻¹ and wave frequency to >100 Hz over several weeks. Sensor data are registered and processed at 16 MHz and 10 bit resolution, with a measuring precision of 0.06±0.04%, and accuracy of 0.51±0.65% (mean ±S.D.. Each instrument is also pressure rated to 120 m and shear stresses ≤20 kNm⁻² allowing deployment in harsh environments. The instrument was deployed across 27 coral reef sites covering the crest (3 m, mid-slope (6 m and deep-slope (9 m depth of habitats directly exposed, oblique or sheltered from prevailing winds. Measurements demonstrate that currents over the reef slope and crest varies immensely depending on depth and exposure: currents differ up to 9-fold within habitats only separated by 3 m depth and 15-fold between exposed, oblique and sheltered habitats. Comparisons to ambient weather conditions reveal that currents around Lizard Island are largely wind driven. Zero to 22.5 knot winds correspond directly to currents of 0 to >82 cms⁻¹, while tidal currents rarely exceed 5.5 cms⁻¹. Rather, current velocity increases exponentially as a function of wave height (0 to 1.6 m and frequency (0.54 to 0.20 Hz, emphasizing the enormous effect of wind and waves on organisms in these shallow coral reef habitats.

  17. Coastal Barrier Resource Areas, Barrier Beaches; s44nbb94; Barrier beaches on the south coast of RI with levels of development as designated by the RI coastal resources management council. Beach zone desginations were hand drafted on photo enlarged source maps and manually digitized, Published in 1995, 1:24000 (1in=2000ft) scale, State of Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Coastal Barrier Resource Areas dataset, published at 1:24000 (1in=2000ft) scale, was produced all or in part from Hardcopy Maps information as of 1995. It is...

  18. Fast spatial atomic layer deposition of Al2O3 at low temperature (<100 °C) as a gas permeation barrier for flexible organic light-emitting diode displays

    International Nuclear Information System (INIS)

    The authors developed a high throughput (70 Å/min) and scalable space-divided atomic layer deposition (ALD) system for thin film encapsulation (TFE) of flexible organic light-emitting diode (OLED) displays at low temperatures (<100 °C). In this paper, the authors report the excellent moisture barrier properties of Al2O3 films deposited on 2G glass substrates of an industrially relevant size (370 × 470 mm2) using the newly developed ALD system. This new ALD system reduced the ALD cycle time to less than 1 s. A growth rate of 0.9 Å/cycle was achieved using trimethylaluminum as an Al source and O3 as an O reactant. The morphological features and step coverage of the Al2O3 films were investigated using field emission scanning electron microscopy. The chemical composition was analyzed using Auger electron spectroscopy. These deposited Al2O3 films demonstrated a good optical transmittance higher than 95% in the visible region based on the ultraviolet visible spectrometer measurements. Water vapor transmission rate lower than the detection limit of the MOCON test (less than 3.0 × 10−3 g/m2 day) were obtained for the flexible substrates. Based on these results, Al2O3 deposited using our new high-throughput and scalable spatial ALD is considered a good candidate for preparation of TFE films of flexible OLEDs

  19. Formation of copper islands on a native SiO2 surface at elevated temperatures

    International Nuclear Information System (INIS)

    A combination of in situ X-ray photoelectron spectroscopy analysis and ex situ scanning electron- and atomic force microscopy has been used to study the formation of copper islands upon Cu deposition at elevated temperatures as a basis for the guided growth of copper islands. Two different temperature regions have been found: (I) up to 250 deg. C only close packed islands are formed due to low diffusion length of copper atoms on the surface. The SiO2 film acts as a barrier protecting the silicon substrate from diffusion of Cu atoms from oxide surface. (II) The deposition at temperatures above 300 deg. C leads to the formation of separate islands which are (primarily at higher temperatures) crystalline. At these temperatures, copper atoms diffuse through the SiO2 layer. However, they are not entirely dissolved in the bulk but a fraction of them forms a Cu rich layer in the vicinity of SiO2/Si interface. The high copper concentration in this layer lowers the concentration gradient between the surface and the substrate and, consequently, inhibits the diffusion of Cu atoms into the substrate. Hence, the Cu islands remain on the surface even at temperatures as high as 450 deg. C.

  20. Faroe Islands

    DEFF Research Database (Denmark)

    Christoffersen, Lisbet

    2015-01-01

    An update introduction including recent legislative changes on the Folkchurch of the Faroe Islands......An update introduction including recent legislative changes on the Folkchurch of the Faroe Islands...

  1. Thermal properties of thin Al{sub 2}O{sub 3} films and their barrier layer effect on thermo-optic properties of TiO{sub 2} films grown by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, Muhammad Rizwan, E-mail: rizwan.saleem@uef.fi [University of Eastern Finland, Institute of Photonics, P.O. Box 111, FI-80101 Joensuu (Finland); National University of Sciences and Technology (NUST), School of Chemical and Materials Engineering (SCME), Sector H-12, Islamabad (Pakistan); Ali, Rizwan; Honkanen, Seppo; Turunen, Jari [University of Eastern Finland, Institute of Photonics, P.O. Box 111, FI-80101 Joensuu (Finland)

    2013-09-02

    We investigate the evaporation of water molecules from the surface of high index, amorphous thin TiO{sub 2} films of various thicknesses t{sub t}, grown by atomic layer deposition (ALD). The desorption of water molecules is impeded by depositing thin ALD-Al{sub 2}O{sub 3} barrier layers of various thicknesses on the TiO{sub 2} thin films. Growing ALD-Al{sub 2}O{sub 3} diffusion barrier layers with different thicknesses t{sub a} allows us to evaluate the water vapor evaporation rate in terms of the change in the thermo–optic coefficient (TOC) of TiO{sub 2} films over a wide spectral range 380 ≤ λ ≤ 1800 nm. An average reduction of 33% in TOC is found at a barrier layer thickness of ∼ 36 nm. Furthermore, the temperature dependent index (dn/dT) and density (dρ/dT) of the ALD-Al{sub 2}O{sub 3} films of various thicknesses t{sub a} are also presented. The Cauchy model is applied to all the ellipsometric measurement data to retrieve the optical constants, and subsequent modeling by the Lorentz–Lorenz relation provides the material density of Al{sub 2}O{sub 3} films. The room temperature values of the thermal coefficients for an ALD-Al{sub 2}O{sub 3} film of thickness t{sub a} ≈ 60 nm at wavelength λ = 640 nm are found to be dn/dT = 4.66 × 10{sup −5}°C{sup −1} and dρ/dT = 4.66 × 10{sup −4}g cm{sup −3}C{sup −1}. - Highlights: • Thermal properties of Al{sub 2}O{sub 3} and TiO{sub 2} films grown by atomic layer deposition • Diffusion barrier effects of Al{sub 2}O{sub 3} films are studied for dn/dT of TiO{sub 2} films. • Thicker Al{sub 2}O{sub 3} films on TiO{sub 2} yield less negative values of dn/dT of TiO{sub 2} films.

  2. The use of epilithic Antarctic lichens (Usnea aurantiacoatra and U. antartica) to determine deposition patterns of heavy metals in the Shetland Islands, Antarctica.

    Science.gov (United States)

    Poblet, A; Andrade, S; Scagliola, M; Vodopivez, C; Curtosi, A; Pucci, A; Marcovecchio, J

    1997-11-27

    Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heavy-metal levels have been measured through atomic absorption spectrophotometry, following internationally accepted analytical methods. The results obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities developed at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. The geographical distribution of trace metals atmospherically transported in the area close to 'Jubany Station' was studied through the corresponding metal contents of the assessed lichens. Finally, the suitability of both analyzed lichen species, Usnea aurantiacoatra and U. antartica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized. PMID:9447747

  3. Synthesis and deposition of basement membrane proteins by primary brain capillary endothelial cells in a murine model of the blood-brain barrier

    DEFF Research Database (Denmark)

    Thomsen, Maj Schneider; Birkelund, Svend; Burkhart, Annette;

    2016-01-01

    The brain vascular basement membrane is important for both blood-brain barrier (BBB) development, stability, and barrier integrity and the contribution hereto from brain capillary endothelial cells (BCECs), pericytes, and astrocytes of the BBB is probably significant. The aim of the present study......-culture, in co-culture with pericytes or mixed glial cells, or as a triple-culture with both pericytes and mixed glial cells. The integrity of the BBB models was validated by measures of transendothelial electrical resistance (TEER) and passive permeability to mannitol. The expression of basement membrane...... proteins was analysed using RT-qPCR, mass spectrometry, and immunocytochemistry. Co-culturing mBCECs with pericytes, mixed glial cells, or both significantly increased the TEER compared to the mono-culture, and a low passive permeability was correlated with high TEER. The mBCECs expressed all major...

  4. DEGRADATION OF SM2ZR2O7 THERMAL BARRIER COATING CAUSED BY CALCIUM-MAGNESIUM-ALUMINUM-SILICON OXIDE (CMAS) DEPOSITION

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Honglong; Sheng, Zhizhi; Tarwater, Emily; Zhang, Xingxing; Dasgupta, Sudip; Fergus, Jeffrey

    2015-03-16

    Rare earth zirconates are promising materials for use as thermal barrier coatings in gas turbine engines. Among the lanthanide zirconate materials, Sm2Zr2O7 with the pyrochlore structure has lower thermal conductivity and better corrosion resistance against calcium-magnesium-aluminum-silicon oxide (CMAS). In this work, after reaction with CMAS, the pyrochlore structure transforms to the cubic fluorite structure and Ca2Sm8(SiO4)6O2 forms in elongated grain.

  5. Plasma-enhanced atomic layer deposition of Cu–Mn films with formation of a MnSixOy barrier layer

    International Nuclear Information System (INIS)

    Conformal Cu–Mn seed layers were deposited by plasma enhanced atomic layer deposition (PEALD) at low temperature (120 °C), and the Mn content in the Cu–Mn alloys were controlled form 0 to approximately 10 atomic percent with various Mn precursor feeding times. Resistivity of the Cu–Mn alloy films decreased by annealing due to out-diffusion of Mn atoms. Out-diffused Mn atoms were segregated to the surface of the film and interface between a Cu–Mn alloy and SiO2, resulting in self-formed MnOx and MnSixOy, respectively. The adhesion between Cu and SiO2 was enhanced by the formation of MnSixOy. Continuous and conductive Cu–Mn seed layers were deposited with PEALD into 24 nm SiO2 trench, enabling a low temperature process, and the trench was perfectly filled using electrochemical plating under conventional conditions.

  6. Tracing the Evolution of Florida's St. Vincent Island

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a history of St. Vincent Island, up to the year that it was bought by the U.S. Fish and Wildlife Service. St. Vincent Island is a natural barrier island...

  7. Galapagos Islands

    Science.gov (United States)

    2002-01-01

    This true-color image of the Galapagos Islands was acquired on March 12, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The Galapagos Islands, which are part of Ecuador, sit in the Pacific Ocean about 1000 km (620 miles) west of South America. As the three craters on the largest island (Isabela Island) suggest, the archipelago was created by volcanic eruptions, which took place millions of years ago. Unlike most remote islands in the Pacific, the Galapagos have gone relatively untouched by humans over the past few millennia. As a result, many unique species have continued to thrive on the islands. Over 95 percent of the islands' reptile species and nearly three quarters of its land bird species cannot be found anywhere else in the world. Two of the more well known are the Galapagos giant tortoise and marine iguanas. The unhindered evolutionary development of the islands' species inspired Charles Darwin to begin The Origin of Species eight years after his visit there. To preserve the unique wildlife on the islands, the Ecuadorian government made the entire archipelago a national park in 1959. Each year roughly 60,000 tourists visit these islands to experience what Darwin did over a century and a half ago. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  8. Modeling the distribution of Norway rats (Rattus norvegicus on offshore islands in the Falkland Islands

    Directory of Open Access Journals (Sweden)

    Michael A. Tabak

    2015-01-01

    Full Text Available Non-native rats (Rattus spp. threaten native island species worldwide. Efforts to eradicate them from islands have increased in frequency and become more ambitious in recent years. However, the long-term success of some eradication efforts has been compromised by the ability of rats, particularly Norway rats (Rattus norvegicus which are good swimmers, to recolonize islands following eradications. In the Falkland Islands, an archipelago in the South Atlantic Ocean, the distance of 250 m between islands (once suggested as the minimum separation distance for an effective barrier to recolonization has shown to be insufficient. Norway rats are present on about half of the 503 islands in the Falklands. Bird diversity is lower on islands with rats and two vulnerable passerine species, Troglodytes cobbi (the only endemic Falkland Islands passerine and Cinclodes antarcticus, have greatly reduced abundances and/or are absent on islands with rats. We used logistic regression models to investigate the potential factors that may determine the presence of Norway rats on 158 islands in the Falkland Islands. Our models included island area, distance to the nearest rat-infested island, island location, and the history of island use by humans as driving variables. Models best supported by data included only distance to the nearest potential source of rats and island area, but the relative magnitude of the effect of distance and area on the presence of rats varied depending on whether islands were in the eastern or western sector of the archipelago. The human use of an island was not a significant parameter in any models. A very large fraction (72% of islands within 500 m of the nearest potential rat source had rats, but 97% of islands farther than 1,000 m away from potential rat sources were free of rats.

  9. A micromorphological study of pedogenic processes in an evolutionary soil sequence formed in late quaternary rhyolitic tephra deposits, North Island, New Zealand.

    NARCIS (Netherlands)

    Bakker, L.; Lowe, D.J.; Jongmans, A.G.

    1996-01-01

    The influence of time as a soil forming factor was studied on an evolutionary sequence of five soils (1850 radiocarbo years BP-ca. 120,000 BP) developed in rhyolitic tephra deposits in New Zealand. New micromorphological observations were combined with existing macromorphological, chemical, textural

  10. Fast spatial atomic layer deposition of Al{sub 2}O{sub 3} at low temperature (<100 °C) as a gas permeation barrier for flexible organic light-emitting diode displays

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hagyoung; Shin, Seokyoon; Jeon, Hyeongtag, E-mail: hjeon@hanyang.ac.kr [Department of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Choi, Yeongtae; Kim, Junghun; Kim, Sanghun; Chung, Seog Chul; Oh, Kiyoung [LIG INVENIA Co., Ltd., Seongnam, Gyeonggi 462-807 (Korea, Republic of)

    2016-01-15

    The authors developed a high throughput (70 Å/min) and scalable space-divided atomic layer deposition (ALD) system for thin film encapsulation (TFE) of flexible organic light-emitting diode (OLED) displays at low temperatures (<100 °C). In this paper, the authors report the excellent moisture barrier properties of Al{sub 2}O{sub 3} films deposited on 2G glass substrates of an industrially relevant size (370 × 470 mm{sup 2}) using the newly developed ALD system. This new ALD system reduced the ALD cycle time to less than 1 s. A growth rate of 0.9 Å/cycle was achieved using trimethylaluminum as an Al source and O{sub 3} as an O reactant. The morphological features and step coverage of the Al{sub 2}O{sub 3} films were investigated using field emission scanning electron microscopy. The chemical composition was analyzed using Auger electron spectroscopy. These deposited Al{sub 2}O{sub 3} films demonstrated a good optical transmittance higher than 95% in the visible region based on the ultraviolet visible spectrometer measurements. Water vapor transmission rate lower than the detection limit of the MOCON test (less than 3.0 × 10{sup −3} g/m{sup 2} day) were obtained for the flexible substrates. Based on these results, Al{sub 2}O{sub 3} deposited using our new high-throughput and scalable spatial ALD is considered a good candidate for preparation of TFE films of flexible OLEDs.

  11. Occurrence of Fe-Mg-rich smectites and corrensite in the Morron de Mateo bentonite deposit (Cabo de Gata region, Spain): A natural analogue of the bentonite barrier in a radwaste repository

    International Nuclear Information System (INIS)

    Highlights: → A hydrothermal process transformed Fe-Mg smectites into corrensite. → This transformation was favoured by the intrusion of the Morron de Mateo dome. → The intrusion caused a temperature increased and a supply of Fe-Mg rich solutions. → The system can be a good natural analogue of bentonite barrier in a radwaste disposal. → Experimental studies of stability of bentonite are in agreement with the results. - Abstract: The Morron de Mateo bentonite deposit is being studied as a natural analogue of the thermal and geochemical effects on a bentonite barrier in a deep geological repository of high level radioactive wastes. This bentonite deposit and its host rocks were intruded by a rhyodacitic volcanic dome that induced a hydrothermal metasomatic process affecting the biocalcarenite beds close to the dome. In this work, the mineralogical and chemical features of the clay minerals of the hydrothermally altered pyroclastic (white tuffs) and epiclastic rocks (mass flow), located in the NE sector of the Morron de Mateo deposit are described. White tuffs have a high content of phyllosilicates, mainly composed of dioctahedral smectites, while mass flow have a higher proportion of inherited minerals, the neoformed phyllosilicates are dioctahedral smectites and an interlayer chlorite/smectite mineral of corrensite type. The chemical composition of smectites reflects the different nature of the parent rocks, in such a way that smectites from white tuffs have a quite homogeneous chemical composition and their structural formulae correspond to montmorillonite type, while smectites from mass flow show more chemical variability, higher Fe and Mg contents and a mean structural formulae corresponding to Fe-Mg-rich beidellite and/or to an intermediate smectite member between beidellite and saponite. In addition, chemical composition and textural features of corrensite-like clay minerals in relation to Fe-Mg-rich smectites in the samples have also been studied

  12. Stratigraphy and eruption ages of deposits at the southeast side of Nishiyama volcano, Hachijo island during the last 2,500 years; Hachijojima, Nishiyama kazan nantoroku ni okeru saikin 2,500 nenkan no funshutsubutsu no sojo to funka nendai

    Energy Technology Data Exchange (ETDEWEB)

    Sugihara, S.; Shimada, S. [Meiji University, Tokyo (Japan)

    1998-10-25

    The Nishiyama volcano of the Hachijo island is a stratovolcano whose volcanic activity started approximately 10,000 years ago. Among the lateral volcanos surrounding the cone-shaped mountain, there is a Kandoyama tuff cone formed by a phreatomagmatic eruption at the southeastern base of the Nishiyama volcano. It is known that Kandoyama`s latest eruption is not older than 4,000 years. In this report, the stratigraphy of eruptive deposits and the types of eruptions involving Nishiyama after Kandoyama formation are clarified. Also, the history of Nishiyama` eruption is discussed, for which a study is made about the stratigraphic relationship between its eruption and the results of {sup 14}C dating or the eruption remainders, corresponding terrestrial episodes recorded in ancient literature usable for eruption dating, etc. The conclusion is summarized below. The eruptive deposits are to be supposedly dated at a period after the completion of caldera aggradation. At the southeastern base of Nishiyama, the eruption of 1605 is to immediately follow the eruption of approximately 1,100 years ago, and no eruption so active as to cause the outflow of lava is noticed therebetween. It is inferred that the Nishiyama volcano erupts once in a period of 300-700 years. 44 refs., 11 figs., 2 tabs.

  13. {sup 137}Cs and excess {sup 210}Pb deposition patterns in estuarine and marine sediment in the central region of the Great Barrier Reef Lagoon, north-eastern Australia

    Energy Technology Data Exchange (ETDEWEB)

    Pfitzner, John E-mail: j.pfitzner@aims.gov.au; Brunskill, Gregg E-mail: g.brunskill@aims.gov.au; Zagorskis, Irena E-mail: i.zagorskis@aims.gov.au

    2004-07-01

    This paper focuses on the distribution of {sup 137}Cs and {sup 210}Pb{sub xs} in 51 estuarine and marine sediment cores collected between the Upstart Bay and Rockingham Bay in the Great Barrier Reef Lagoon, north-eastern Australia. Historical records of {sup 210}Pb{sub xs} and {sup 137}Cs atmospheric deposition and present day terrestrial inventories in north-eastern Australia are presented. {sup 210}Pb{sub xs} and {sup 137}Cs fluxes measured on suspended sediments in the Burdekin River are considered to be a source of recent inputs of these nuclides to the nearshore region of this part of the Great Barrier Reef. Direct correlations between sediment nuclide inventories, maximum detectable depths, and sediment mass accumulation rates (MARs), calculated using both {sup 137}Cs and {sup 210}Pb{sub xs}, are explored. In relation to inventories of {sup 210}Pb{sub xs}, 60% of atmospheric fallout {sup 137}Cs appears to be missing from the sediments. The reasons for these differences in two tracers, primarily of atmospheric origin, are discussed in terms of the geochemical properties of these two nuclides. Evidence is presented to support the hypothesis that the {sup 137}Cs distribution in these cores can be a useful independent tracer which provides confirmation of MARs calculated from the decay of {sup 210}Pb{sub xs}.

  14. Growth of Ultra-thin Ruthenium and Ruthenium Alloy Films for Copper Barriers

    OpenAIRE

    Liao, Wen; Bost, Daniel; Ekerdt, John G.

    2016-01-01

    We report approaches to grow ultrathin Ru films for application as a seed layer and Cu diffusion barrier. For chemical vapor deposition (CVD) with Ru3(CO)12 we show the role surface hydroxyl groups have in nucleating the Ru islands that grow into a continuous film in a Volmer-Weber process, and how the nucleation density can be increased by applying a CO or NH3 overpressure. Thinner continuous films evolve in the presence of a CO overpressure. We report an optimun ammonia overpressure for Ru ...

  15. Diagnostic of a Hollow Cathode Radio-Frequency Plasma Excited in Organosilicon HMDSO, used for Barrier Anti Corrosion Thin Films Deposition

    International Nuclear Information System (INIS)

    In this work, remote hollow cathode RF plasma, generated from the monomer hexamethyledisiloxane (HMDSO), as a precursor, and argon as a feed gas, and the plasma mixture HMDSO/O2 have been studied, as a function of different plasma parameters such as: RF applied power (100-300 W), HMDSO flow rate (2-32 sccm), time deposition (5-20 minutes), and oxygen fraction in HMDSO/O2 mixture (0-0.9). Plasma diagnostic and prepared thin films characterization have been investigated. (author)

  16. Geologic Survey of the 2 April 2007 Solomon Islands Earthquake and Tsunami

    Science.gov (United States)

    Rafiau, W. B.; Jackson, K. L.; Billy, D.; Bonte-Grapentin, M.; Kruger, J.; McAdoo, B. G.; Moore, A. L.; Tiano, B.

    2007-12-01

    The 2 April 2007 magnitude 8.1 Solomon Islands earthquake and tsunami caused extensive damage to coral reefs, coastal erosion, and in some locations, 3 meters of uplift, subsidence, and numerous landslides in the Western and Choiseul Provinces. Extensive damage to the coral reefs ranged from shattered branching corals to 4 meter head corals snapped off their bases and toppled over. The fringing reef on the east coast of Ranongga sustained the greatest degree of damage as it was uplifted 3 m above sea level and remains completely exposed. Sediment samples were collected along transects extended from offshore to onshore environments for larger islands, such as Ghizo, where the tsunami did not pass over the entire island. Smaller islands, such as Nusa Aghana, a transect was conducted from the outer barrier reefs, through the lagoon, across the island, and offshore on the opposing side of the island. Offshore data was collected using a side-scan sonar system that records bathymetry and images coral reef morphology. This data was coupled with snorkeling and SCUBA diving to ground truth the offshore lagoon and reef environments. Sediment samples were collected offshore every 5 m and were documented by underwater photos and GPS coordinates. Offshore to onshore sediment transects reveal that sediment was eroded from seaward facing shorelines, deposited a thin veneer of sediment on islands, and transported the majority of the sediment on coral reefs on the lagoon side of islands, essentially burying coral and lagoonal sediment. Coral reef damaged by the earthquake and tsunami represents a major concern for an already threatened ecosystem. Recovery of the fishing and dive tourism economies rely on the healthy reestablishment of the reef.

  17. Influence of PEDOT:PSS on the effectiveness of barrier layers prepared by atomic layer deposition in organic light emitting diodes

    International Nuclear Information System (INIS)

    Organic light emitting diodes (OLEDs) are well suited for energy saving lighting applications, especially when thinking about highly flexible and large area devices. In order to avoid the degradation of the organic components by water and oxygen, OLEDs need to be encapsulated, e.g., by a thin sheet of glass. As the device is then no longer flexible, alternative coatings are required. Atomic layer deposition (ALD) is a very promising approach in this respect. The authors studied OLEDs that were encapsulated by 100 nm Al2O3 deposited by ALD. The authors show that this coating effectively protects the active surface area of the OLEDs from humidity. However, secondary degradation processes still occur at sharp edges of the OLED stack where the extremely thin encapsulation layer does not provide perfect coverage. Particularly, the swelling of poly(3,4-ethylenedioxythiophene) mixed with poly(styrenesulfonate), which is a popular choice for the planarization of the bottom electrode and at the same time acts as a hole injection layer, affects the effectiveness of the encapsulation layer

  18. Influence of PEDOT:PSS on the effectiveness of barrier layers prepared by atomic layer deposition in organic light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Wegler, Barbara, E-mail: barbara.wegler@siemens.com [Siemens AG, Corporate Technology, Guenther-Scharowsky-Strasse 1, 91058 Erlangen, Germany and Center for Medical Physics and Engineering, University of Erlangen-Nuremberg, Henkestrasse 91, 91052 Erlangen (Germany); Schmidt, Oliver [Siemens AG, Corporate Technology, Guenther-Scharowsky-Strasse 1, 91058 Erlangen (Germany); Hensel, Bernhard [Center for Medical Physics and Engineering, University of Erlangen-Nuremberg, Henkestrasse 91, 91052 Erlangen (Germany)

    2015-01-15

    Organic light emitting diodes (OLEDs) are well suited for energy saving lighting applications, especially when thinking about highly flexible and large area devices. In order to avoid the degradation of the organic components by water and oxygen, OLEDs need to be encapsulated, e.g., by a thin sheet of glass. As the device is then no longer flexible, alternative coatings are required. Atomic layer deposition (ALD) is a very promising approach in this respect. The authors studied OLEDs that were encapsulated by 100 nm Al{sub 2}O{sub 3} deposited by ALD. The authors show that this coating effectively protects the active surface area of the OLEDs from humidity. However, secondary degradation processes still occur at sharp edges of the OLED stack where the extremely thin encapsulation layer does not provide perfect coverage. Particularly, the swelling of poly(3,4-ethylenedioxythiophene) mixed with poly(styrenesulfonate), which is a popular choice for the planarization of the bottom electrode and at the same time acts as a hole injection layer, affects the effectiveness of the encapsulation layer.

  19. Evolution and preservation potential of fluvial and transgressive deposits on the Louisiana inner shelf: Understanding depositional processes to support coastal management

    Science.gov (United States)

    Flocks, J.; Miner, M.D.; Twichell, D.C.; Lavoie, D.L.; Kindinger, J.

    2009-01-01

    The barrier-island systems of the Mississippi River Delta plain are currently undergoing some of the highest rates of shoreline retreat in North America (???20 m/year). Effective management of this coastal area requires an understanding of the processes involved in shoreline erosion and measures that can be enacted to reduce loss. The dominant stratigraphy of the delta plain is fluvial mud (silts and clays), delivered in suspension via a series of shallow-water delta lobes that prograded across the shelf throughout the Holocene. Abandonment of a delta lobe through avulsion leads to rapid land subsidence through compaction within the muddy framework. As the deltaic headland subsides below sea level, the marine environment transgresses the bays and wetlands, reworking the available sands into transgressive barrier shorelines. This natural process is further complicated by numerous factors: (1) global sea-level rise; (2) reduced sediment load within the Mississippi River; (3) diversion of the sediment load away from the barrier shorelines to the deep shelf; (4) storm-induced erosion; and (5) human alteration of the littoral process through the construction of hardened shorelines, canals, and other activities. This suite of factors has led to the deterioration of the barrier-island systems that protect interior wetlands and human infrastructure from normal wave activity and periodic storm impact. Interior wetland loss results in an increased tidal prism and inlet cross-sectional areas, and expanding ebb-tidal deltas, which removes sand from the littoral processes through diversion and sequestration. Shoreface erosion of the deltaic headlands does not provide sufficient sand to balance the loss, resulting in thinning and dislocation of the islands. Abatement measures include replenishing lost sediment with similar material, excavated from discrete sandy deposits within the muddy delta plain. These sand bodies were deposited by the same cyclical processes that formed the

  20. Phase evolution, interdiffusion and failure of La2(Zr0.7Ce0.3)2O7/YSZ thermal barrier coatings prepared by electron beam–physical vapor deposition

    International Nuclear Information System (INIS)

    Highlights: • No interruption of column morphology from YSZ to LZ7C3 layer in TBCs. • A fluorite to pyrochlore ordering occurs for LZ7C3 during thermal shocking. • Some diffusion of Y from YSZ to LZ7C3 layer is occurred after thermal shocking. • Outward diffusion of Cr takes place due to the chemical reaction of LZ7C3 and Cr. • The delaminations occur at interface of LZ7C3/YSZ and inside the LZ7C3 coating. - Abstract: La2(Zr0.7Ce0.3)2O7 (LZ7C3) has attracted great interest for thermal barrier coatings (TBCs) because it presents extremely low thermal conductivity, high thermal stability and is more resistant to sintering than yttria stabilized zirconia (YSZ). In the present study, an LZ7C3/YSZ double-ceramic-layer (DCL) TBC was deposited by electron beam–physical vapor deposition (EB–PVD) and the TBC system was investigated for its phase evolution, interdiffusion and failure pattern though thermal shock test at 1373 K. X-ray diffraction and Raman spectra results indicate that the as-deposited LZ7C3 coating transforms from fluorite to pyrochlore structure upon thermal shocking between 373 K and 1373 K. It seems that this phase change may have affected the durability of the DCL TBCs. The EDS mapping analysis indicates that some diffusion of Y from YSZ to LZ7C3 layer is occurred after thermal shock test. Additionally, an obvious outward diffusion of Cr from bond coat into LZ7C3 layer takes place due to the chemical reaction of LZ7C3 and Cr. The phase transformation of LZ7C3, the abnormal oxidation of bond coat, and the outward diffusion of Y and Cr alloying element into LZ7C3 coating would be the primary factors for the spallation of LZ7C3/YSZ thermal barrier coating

  1. Transport barriers in helical systems

    International Nuclear Information System (INIS)

    There are some publications with indications that the formation of transport barriers in toroidal devices could take place in the vicinity of low order rational surfaces (RS). It is necessary to note that the environs of RS have very important peculiarities. In particular, a stochastic layer of magnetic field lines forms instead of separaterix which must separate the island surfaces from the adjacent to them non-island surfaces in stellarator magnetic configurations. The attempt to realize the formation of transport barriers near RS and to study their influence on the RF discharge plasma confinement was undertaken in presented experiments on the U-3M torsatron. The presupposition was made that the radial electric field profile would have sharp change on the width of stochastic layer near RS in the case of collisionless longitudinal motion of electrons in this layer. Experimental data obtained on the U-3M torsatron during the formation of interior and edge transport barriers are in a good agreement with this presupposition. The results of experiments on the U-3M torsatron are discussed in comparison with data of other helical systems. It is shown that the number of dependences (the threshold power and density, the time of barrier formation, the localization of radial electric field shear layer) are in a good agreement for all these systems. In conclusion, the common features of formation of transport barriers in non- axisymmetric and non-axisymmetric systems are discussed. (author)

  2. A 6,000-years record of atmospheric mercury accumulation in the high Arctic from peat deposits on Bathurst Island, Nunavut, Canada

    DEFF Research Database (Denmark)

    Givelet, N.; Roos-Barraclough, F.; Goodsite, M. E.;

    2003-01-01

    There is a growing interest in the atmospheric transport, deposition, and accumulation of anthropogenic Hg in the Arctic. To quantify the impact of industrial Hg emissions, the natural rate of atmospheric Hg accumulation must be known. Mercury concentration measurements and age dating of peat from...... the Canadian Arctic show that natural "background" Hg flux rather constant (ca. 1 microgram per sq. m per yr.) throughout the past 6,000 years. Mercury concentrations in surface peat layers are much higher, but chronology of these changes cannot be interpreted until more age dates are available. The elevated...... Hg concentrations in surface layers, however, are out of proportion with Br and Se, suggesting that there has been a significant human impact. Peat cores from southern Canada provide a record of atmospheric Hg accumulation extending back nine thousand years, with similar background fluxes. Thus, pre...

  3. Anomalous scaling of Cu-island dynamics on Ag(100)

    Energy Technology Data Exchange (ETDEWEB)

    Zaum, Christopher; Morgenstern, Karina [Institut fuer Festkoerperphysik, Gottfried Wilhelm Leibniz Universitaet, Appelstr. 2, D-30167 Hannover (Germany)

    2008-07-01

    We deposited Cu-islands containing 10 to 500 atoms on a clean Ag(100) surface at room temperature and investigated diffusion and decay of these islands with a fast scanning tunneling microscope. Islands at sizes above 80 atoms per island are adsorbed in hollow-sites. Islands at sizes below 80 atoms per island are adsorbed in bridge-sites. Diffusion and decay behavior of the hollow-site islands is similar to the behavior of both Ag-islands on Ag(100) and Cu-islands on Cu(100). In contrast, the diffusivity and the decay time of the bridge-site islands are significantly higher than any previously measured values. This indicates a novel mechanism of diffusion.

  4. The hydrology of Hatteras Island, North Carolina

    Science.gov (United States)

    Anderson, William Paul, Jr.

    This is a study of the groundwater hydrology and groundwater-surface-water interactions of barrier islands. Shallow groundwater is typically the sole source of freshwater on barrier islands. It is threatened by increasing coastal populations (both permanent and seasonal residents). Higher demand for groundwater may induce saltwater intrusion through overpumping. Water quality also is often threatened by inadequate waste-management practices and overwash. These factors combine to make understanding of barrier-island hydrology essential for continued development and ecological health of island communities. The hydraulic response of barrier islands is closely tied to island morphology and stratigraphy. The heterogeneity of barrier islands suggests that the underlying geologic framework is critical to barrier-island morphology. Other processes, such as spit growth, are usually imposed on an inherited geologic framework. Barrier islands typically support a freshwater aquifer that "floats" on an underlying saltwater aquifer. The height to which the water table rises depends on the hydraulic parameters of the aquifer and the island geometry. In addition, tidal fluctuations, interdunal wetland drainage, and variable recharge rates affect island hydrology. The relative importance of each of these factors was tested with a series of numerical simulations, sensitivity analyses, and field measurements. Field data were collected from Hatteras Island in order to provide calibration data, constrain the shallow stratigraphy, and estimate aquifer parameters. Geophysical studies include borehole geophysics and ground-penetrating radar (GPR). The Buxton Woods surficial aquifer is approximately 24.5 meters in thickness and contains upper and lower permeable zones separated by a semi-confining layer. Geophysical methods were used to constrain the shallow stratigraphy and the vertical geometry of the system. Borehole geophysics indicate the large-scale variations in stratigraphy. GPR

  5. 2007 Solomon Islands Tsunami Left Little Sand Onshore, Buried Backshore Reefs

    Science.gov (United States)

    Moore, A. L.; Jackson, K. L.; Kruger, J.; McAdoo, B. G.; Rafiau, W. B.; Tiano, B.; Woodward, S. M.

    2007-12-01

    In many places struck by the 2007 Solomon Islands tsunami, little onshore record of the tsunami's passage remains yet considerable sediment was transported offshore. This sediment represents an ecological hazard in tropical regions because of its potential for burying coral reefs. At Nusa Agana, a 50 m-wide, 2 m-high barrier island ~36 km N of the epicenter, flow depths recorded by debris wrapped around tree trunks did not exceed 50 cm--the sedimentary record on land was similarly small at ~2 cm thick. Nevertheless, the "outer" coastline of the island was stripped of sediment and the "inner" coastline filled with enough sediment to bury coral reefs to an extent that only soft corals at the top of the reef survive. The source of the sediment appears to be a mixture of sand from both the outer and inner beach, suggesting that scour occurred at both these locations. Perhaps because of the island's low relief, Nusa Agana acted less as a barrier to flow and more as a topographic high; sediment cover thinned over the high and selectively infilled the topographic low of the lagoon. At Tapurai, ~55 km ENE of the epicenter, the tsunami left a layer of coral rubble 20-30 cm thick and moved basalt boulders up to 1 m in diameter more than 100 m inland. The tsunami here reached flow depths of more than 8 m and swept N-SW across fan-shaped Tapurai, piling coral rubble mixed from offshore reefs and the modern beach onto farm fields before striking a basalt cliff behind the town and deflecting SW, carrying basalt debris with it before exiting through the town's harbor. The sediment leaves a vivid account of the passage of the wave, progressing from a solely coral rubble deposit to a mixed basalt-coral deposit and thinning downflow as sediment supply waned. Where the tsunami washed completely over islands, the side facing the waves is typically stripped of sediment, whereas the lee side shows a well developed scarp, suggesting that at least some tsunami scarps are formed during

  6. Information barriers

    International Nuclear Information System (INIS)

    An information barrier (IB) consists of procedures and technology that prevent the release of sensitive information during a joint inspection of a sensitive nuclear item, and provides confidence that the measurement system into which it has been integrated functions exactly as designed and constructed. Work in the U.S. on radiation detection system information barriers dates back at least to 1990, even though the term is more recent. In January 1999, an Information Barrier Working Group (IBWG) was formed in the United States to help coordinate technical efforts related to information barrier research and development (R and D). This paper presents an overview of the efforts of this group, by its present and former Chairs, as well as recommendations for further information barrier R and D. Progress on the demonstration of monitoring systems containing IBs is also provided. From the U.S. IBWG perspective, the top-level functional requirements for the information barrier portion of an integrated radiation signature-information barrier inspection system are twofold: The host must be assured that its classified information is protected from disclosure to the inspecting party; and The inspecting party must be confident that the integrated inspection system measures, processes, and presents the radiation-signature-based measurement conclusion in an accurate and reproducible manner. It is the position in the United States that in the absence of any agreement to share classified nuclear weapons design information while implementing an inspection regime, the need to protect host country classified warhead design information is paramount and overrules the need to provide confidence to the inspecting party regarding the accuracy and reproducibility of the measurements. The U.S. IBWG has reached a consensus on several critical design elements that define a general standard for radiation signature information barrier design. Technical specialists from cooperating parties must be

  7. Minority Women's Health: Native Hawaiians and Other Pacific Islanders

    Science.gov (United States)

    ... and other Pacific Islanders American Indians/Alaska Natives Immigrant and migrant issues Taking care of your health ... Americans to be uninsured or on Medicaid. Cultural, social, and geographic barriers, as well as distrust of ...

  8. Happy Island

    CERN Document Server

    McLerran, Larry

    2011-01-01

    I discuss the phase diagram for QCD in the baryon chemical potential and temperature plane. I argue that there is a new phase of matter different from the deconfined Quark Gluon Plasma: Quarkyonic Matter. Quarkyonic Matter is confined and exists at densities parametrically large compared to the QCD scale, when the number of quark colors, $N_c$ is large. I motivate the possibility that Quarkyonic Matter is in an inhomogeneous phase, and is surrounded by lines of phase transitions, making a Happy Island in the $\\mu_B$-T plane. I conjecture about the geography of Happy Island.

  9. Two-Dimensional Island Shape Determined by Detachment

    Science.gov (United States)

    Saito, Yukio; Kawasaki, Ryo

    2007-07-01

    Effect of an anisotropic detachment on a heteroepitaxial island shape is studied by means of a kinetic Monte Carlo simulation of a square lattice gas model. Only with molecular deposition followed by surface diffusion, islands grow in a ramified dendritic shape, similar to diffusion-limited aggregate (DLA). Introduction of molecular detachment from edges makes islands compact. To understand an anisotropic island shape observed in the experiment of pentacene growth on a hydrogen-terminated Si(111) vicinal surface, asymmetry in detachment around the substrate step is assumed. Edge molecules detach more to the higher terrace than to the lower terrace. The island edge from which molecules are easy to detach is smooth and the one hard to detach is dendritic. If islands are close to each other, islands tend to align in a line, since detached molecules from the smooth edge of the right island are fed to the dendritic and fast growing edge of the left island.

  10. Understanding the effects of strain on morphological instabilities of a nanoscale island during heteroepitaxial growth

    International Nuclear Information System (INIS)

    A comprehensive morphological stability analysis of a nanoscale circular island during heteroepitaxial growth is presented based on continuum elasticity theory. The interplay between kinetic and thermodynamic mechanisms is revealed by including strain-related kinetic processes. In the kinetic regime, the Burton-Cabrera-Frank model is adopted to describe the growth front of the island. Together with kinetic boundary conditions, various kinetic processes including deposition flow, adatom diffusion, attachment-detachment kinetics, and the Ehrlich-Schwoebel barrier can be taken into account at the same time. In the thermodynamic regime, line tension, surface energy, and elastic energy are considered. As the strain relief in the early stages of heteroepitaxy is more complicated than commonly suggested by simple consideration of lattice mismatch, we also investigate the effects of external applied strain and elastic response due to perturbations on the island shape evolution. The analytical expressions for elastic fields induced by mismatch strain, external applied strain, and relaxation strain are presented. A systematic approach is developed to solve the system via a perturbation analysis which yields the conditions of film morphological instabilities. Consistent with previous experimental and theoretical work, parametric studies show the kinetic evolution of elastic relaxation, island morphology, and film composition under various conditions. Our present work offers an effective theoretical approach to get a comprehensive understanding of the interplay between different growth mechanisms and how to tailor the growth mode by controlling the nature of the crucial factors

  11. Simulation of multilayer Cu/Pd(100) heteroepitaxial growth by pulse laser deposition

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The heteroepitaxial growth of multilayer Cu/Pd(100) thin film via pulse laser deposition (PLD) at room temperature is simulated by using kinetic Monte Carlo (KMC) method with realistic physical parameters. The effects of mass transport between interlayers, edge diffusion of adatoms along the islands and instantaneous deposition are considered in the simulation model. Emphasis is placed on revealing the details of multilayer Cu/Pd(100) thin film growth and estimating the Ehrlich-Schwoebel (ES) barrier. It is shown that the instantaneous deposition in the PLD growth gives rise to the layer-by-layer growth mode, persisting up to about 9 monolayers (ML) of Cu/Pd(100). The ES arriers of 0.08 ± 0.01 eV is estimated by comparing the KMC simulation results with the real scanning tunnelling microscopy (STM) measurements.

  12. Barrier properties of natural clay minerals

    OpenAIRE

    Дудар, Т.В.; С.П. Бугера; В.М. Кадошніков; Б.П. Злобенко

    2009-01-01

     Clay minerals is a perfect material for geochemical barrier due to their high water resistivity, plasticity, high sorbing capacity, well developed surface and cheapness in extraction and processing. This work studies the peculiarities of uranium sorbtion on clay minerals on the example of bentonite and palygorskite clay from Cherkassy deposit, and clay usage as a barrier material.

  13. Barrier properties of natural clay minerals

    Directory of Open Access Journals (Sweden)

    Т.В. Дудар

    2009-01-01

    Full Text Available  Clay minerals is a perfect material for geochemical barrier due to their high water resistivity, plasticity, high sorbing capacity, well developed surface and cheapness in extraction and processing. This work studies the peculiarities of uranium sorbtion on clay minerals on the example of bentonite and palygorskite clay from Cherkassy deposit, and clay usage as a barrier material.

  14. Solomon Islands

    OpenAIRE

    World Bank

    2015-01-01

    This report aims to build understanding of the existing disaster risk financing and insurance (DRFI) tools in use in the Solomon Islands and to identify gaps where engagement could further develop financial resilience. It also aims to encourage peer exchange of regional knowledge, specifically by encouraging dialogue on past experiences, lessons learned, optimal use of these financial tool...

  15. Created versus natural coastal islands: Atlantic waterbird populations, habitat choices, and management implications

    Science.gov (United States)

    Erwin, R.M.; Allen, D.H.; Jenkins, D.

    2003-01-01

    Nesting colonial waterbirds along the Atlantic Coast of the United States face a number of landscape-level threats including human disturbance, mammalian predator expansion, and habitat alteration. There have been changes from 1977 to the mid-1990s in use of nesting habitats and populations of a number of seabird species of concern in the region, including black skimmers Rynchops niger Linnaeaus, common terns Sterna hirundo Linnaeaus, gull-billed terns Sterna nilotica Linnaeaus, least terns Sterna antillarum Lesson, royal terns Sterna maxima Boddaert, and sandwich terns Sterna sandvicensis Cabot. These species form colonies primarily on the following habitat types: large, sandy barrier or shoal islands, natural estuarine or bay islands (mostly marsh), man-made islands of dredged deposition materials (from navigation channels), and the mainland. Significant changes in the use of the dredged material islands have occurred for these species in New Jersey and North Carolina, but not in Virginia. Population declines and changes in bird habitat use appear to be at least partially associated with the conditions and management of the existing dredged material islands, coastal policy changes associated with creating new dredged material islands, and competing demands for sand for beach augmentation by coastal communities. As these and other coastal habitats become less suitable for colonial waterbirds, other manmade sites, such as bridges and buildings have become increasingly more important. In regions with intense recreational demands, coastal wildlife managers need to take a more aggressive role in managing natural and man-made habitats areas and as stakeholders in the decision-making process involving dredged materials and beach sand allocation.

  16. Simulation on Stress Accumulation during the Path-by-path Deposition Process of Thermal Barrier Coating by Plasma Spraying%等离子喷涂热障涂层逐道沉积累积应力的模拟

    Institute of Scientific and Technical Information of China (English)

    田甜; 郑振环; 李强

    2012-01-01

    运用ANSYS12.0软件,对等离子喷涂热障涂层逐道沉积过程中的累积应力进行了有限元模拟.结果表明,涂层制备过程中,已喷涂层的温度随喷枪移动呈周期性大幅波动,这种快速热冲击使得涂层中产生了相应的应力波动.涂层喷涂结束并冷却至室温后,边缘存在应力集中,陶瓷层与粘结层的界面边缘处最大切向拉应力为122 MPa.涂层各界面中部应力值呈波浪状周期性浮动,X方向应力是主要的应力形式.%Finite element simulatin on stress accumulation during the path-by-path deposilin process of thermal barrier coating by plasma spraying was performed by FEM software ANSYS12.0. During the spraying process, the temperature of the deposited coating fluctuates with the movement of the spraying gun periodically within a wide range. This rapid thermal shock will cause a corresponding stress fluctuation. After the coating being cooled to the room temperture, concentrated stress appeared at the edge of the coating, the maximum shear tensile stress existed at the edge of the interface between the ceramic layer and the bonding layer is 122 MPa. Stress at the middle of the interfaces of the coating fluctuates periodically like a wave and stress in the X direction is the major stress.

  17. Shape evolution of Ge/Si(001) islands induced by strain-driven alloying

    International Nuclear Information System (INIS)

    The shape evolution of Ge/Si(001) islands grown by ultrahigh vacuum chemical vapor deposition were investigated by atomic force microscopy at different deposition rates. We find that, at low deposition rates, the evolution of islands follows the conventional pathway by which the islands form the pyramid islands, evolve into dome islands, and dislocate at a superdome shape with increasing coverage. While at a high deposition rate of 3 monolayers per minute, the dome islands evolve towards the pyramids by a reduction of the contact angle. The presence of the atomic intermixing between the Ge islands and Si substrate at high deposition rate is responsible for the reverse evolution. [copyright] 2001 American Institute of Physics

  18. Information barriers

    International Nuclear Information System (INIS)

    Full text: An information barrier (IB) consists of procedures and technology that prevent the release of sensitive information during a joint inspection of a sensitive nuclear item, and provides confidence that the measurement system into which it has been integrated functions exactly as designed and constructed. Work in the U.S. on radiation detection system information barriers dates back at least to 1990, even though the terminology is more recent. In January 1999 the Joint DoD-DOE Information Barrier Working Group was formed in the United States to help coordinate technical efforts related to information barrier R and D. This paper presents an overview of the efforts of this group, by its Chairs, as well as recommendations for further information barrier R and D. Progress on the demonstration of monitoring systems containing IBs is also provided. From the U.S. perspective, the basic, top-level functional requirements for the information barrier portion of an integrated radiation signature-information barrier inspection system are twofold: The host must be assured that his classified information is protected from disclosure to the inspecting party; and The inspecting party must be confident that the integrated inspection system measures, processes, and presents the radiation-signature-based measurement conclusion in an accurate and reproducible manner. It is the position of the United States that in the absence of any agreement to share classified nuclear weapons design information in the conduct of an inspection regime, the requirement to protect host country classified warhead design information is paramount and admits no tradeoff versus the confidence provided to the inspecting party in the accuracy and reproducibility of the measurements. The U.S. has reached an internal consensus on several critical design elements that define a general standard for radiation signature information barrier design. These criteria have stood the test of time under intense

  19. Influence of layer type and order on barrier properties of multilayer PECVD barrier coatings

    Science.gov (United States)

    Bahroun, K.; Behm, H.; Mitschker, F.; Awakowicz, P.; Dahlmann, R.; Hopmann, Ch

    2014-01-01

    Due to their macromolecular structure, plastics are limited in their scope of application whenever high barrier functionality against oxygen and water vapour permeation is required. One solution is the deposition of thin silicon oxide coatings in plasma-enhanced chemical vapour deposition (PECVD) processes. A way to improve performance of barrier coatings is the use of multilayer structures built from dyad layers, which combine an inorganic barrier layer and an organic intermediate layer. In order to investigate the influence of type and number of dyads on the barrier performance of coated 23 µm PET films, different dyad setups are chosen. The setups include SiOCH interlayers and SiOx-barrier layers deposited using the precursor hexamethyldisiloxane (HMDSO). A single reactor setup driven in pulsed microwave plasma (MW) mode as well as capacitively coupled plasma (CCP) mode is chosen. In this paper the effects of a variation in intermediate layer recipe and stacking order using dyad setups on the oxygen barrier properties of multilayer coatings are discussed with regard to the chemical structure, morphology and activation energy of the permeation process. Changes in surface nano-morphology of intermediate layers have a strong impact on the barrier properties of subsequent glass-like coatings. Even a complete failure of the barrier is observed. Therefore, when depositing multilayer barrier coatings, stacking order has to be considered.

  20. Influence of layer type and order on barrier properties of multilayer PECVD barrier coatings

    International Nuclear Information System (INIS)

    Due to their macromolecular structure, plastics are limited in their scope of application whenever high barrier functionality against oxygen and water vapour permeation is required. One solution is the deposition of thin silicon oxide coatings in plasma-enhanced chemical vapour deposition (PECVD) processes. A way to improve performance of barrier coatings is the use of multilayer structures built from dyad layers, which combine an inorganic barrier layer and an organic intermediate layer. In order to investigate the influence of type and number of dyads on the barrier performance of coated 23 µm PET films, different dyad setups are chosen. The setups include SiOCH interlayers and SiOx-barrier layers deposited using the precursor hexamethyldisiloxane (HMDSO). A single reactor setup driven in pulsed microwave plasma (MW) mode as well as capacitively coupled plasma (CCP) mode is chosen. In this paper the effects of a variation in intermediate layer recipe and stacking order using dyad setups on the oxygen barrier properties of multilayer coatings are discussed with regard to the chemical structure, morphology and activation energy of the permeation process. Changes in surface nano-morphology of intermediate layers have a strong impact on the barrier properties of subsequent glass-like coatings. Even a complete failure of the barrier is observed. Therefore, when depositing multilayer barrier coatings, stacking order has to be considered. (paper)

  1. Coastal Barrier Resource Areas, RI CRMC - Coastal Water Use Type; CRMCWT08; Vector polygon represenations of all RI Water Subject to CRMC Regulation as described in the Publication "The State of Rhode Island, Coastal Resources Management Program, As Amended", Published in 2008, 1:4800 (1in=400ft) scale, State of Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Coastal Barrier Resource Areas dataset, published at 1:4800 (1in=400ft) scale, was produced all or in part from Hardcopy Maps information as of 2008. It is...

  2. Biotic and Sedimentologic Signals Associated with Tempestite Deposition from Baffin Bay, Texas

    Science.gov (United States)

    Van Nieuwenhuise, D. S.

    2014-12-01

    In efforts to determine hurricane frequency prior to historical records, the often used model of counting presumed washover fans as coarse-grained hurricane deposits that interfinger with fine-grained, quiet, lagoon sediments may be oversimplified. The complexities of hurricane depositional events versus the usual dynamic sedimentological processes of barrier island complexes often makes it difficult to distinguish between expected and typical migrating coarse-grained facies from true hurricane deposits. To avoid some of this potential confusion and to better recognize the frequency of strong hurricane events, it is suggested that studies be focused further inland than the washover fans and that in addition to sedimentological indicators, they include biotic and chemical discriminators as well. These results are part of a broader study examining hurricane deposition along the Texas coast. The focus of this study is on slowly accumulating algal mats near Baffin Bay, Texas, that are punctuated by known hurricane deposits. This marginal lagoonal setting is more than 16 miles away from the Padre Island shorefront. Two cores were taken in 1974 that captured sediments from Hurricane Carla (1970) and Hurricane Beulah (1967). Algal mat depositional rates are on the order of 1.25 cm per year whereas the hurricane sediments are on the order of 45 cm per event. Sediments display flood and ebb surge stages for each event. Additional cores in other parts of the coast have similar sediment accumulation rates. In general, periods of relatively quiet deposition are dominated by Cyprideis ovata and Ammonia becarrii which can tolerate the conditions of these euryhaline and algal-floored ponds. In contrast, hurricane deposits show clear evidence of additional bay and shallow marine assemblages along with coarse-grained sediments, shell and shell fragments, and significant amounts of mud settling after the retreat of the storm surge.

  3. Long spin lifetime and large barrier polarisation in single electron transport through a CoFe nanoparticle

    Science.gov (United States)

    Temple, R. C.; McLaren, M.; Brydson, R. M. D.; Hickey, B. J.; Marrows, C. H.

    2016-01-01

    We have investigated single electron spin transport in individual single crystal bcc Co30Fe70 nanoparticles using scanning tunnelling microscopy with a standard tungsten tip. Particles were deposited using a gas-aggregation nanoparticle source and individually addressed as asymmetric double tunnel junctions with both a vacuum and a MgO tunnel barrier. Spectroscopy measurements on the particles show a Coulomb staircase that is correlated with the measured particle size. Field emission tunnelling effects are incorporated into standard single electron theory to model the data. This formalism allows spin-dependent parameters to be determined even though the tip is not spin-polarised. The barrier spin polarisation is very high, in excess of 84%. By variation of the resistance, several orders of magnitude of the system timescale are probed, enabling us to determine the spin relaxation time on the island. It is found to be close to 10 μs, a value much longer than previously reported. PMID:27329575

  4. Results of geoelectrical surveys in the area of Crater 70, Deception Island, Maritime Antarctica

    OpenAIRE

    Correia, Antonio; Vieira, Gonçalo

    2015-01-01

    Deception Island is horse-shoe shaped stratovolcano with 15 km diameter and a large caldera that opens towards the southeast, forming a bay about 7 km wide. The maximum altitude is at Mount Pond (539 m a.s.l.). About 57% of the island area is covered by glaciers. In geological terms Deception Island is composed of volcano-sedimentary deposits, including pyroclastic flows and deposits, strombolian scoriae and lava, volcanic and hypo-volcanic indurated ashes, and phreatomagmatic deposits. Recen...

  5. Combustion chemical vapor desposited coatings for thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Hampikian, J.M.; Carter, W.B. [Georgia Institute of Technology, Atlanta, GA (United States)

    1995-10-01

    The new deposition process, combustion chemical vapor deposition, shows a great deal of promise in the area of thermal barrier coating systems. This technique produces dense, adherent coatings, and does not require a reaction chamber. Coatings can therefore be applied in the open atmosphere. The process is potentially suitable for producing high quality CVD coatings for use as interlayers between the bond coat and thermal barrier coating, and/or as overlayers, on top of thermal barrier coatings.

  6. Islands for SAT

    OpenAIRE

    H Fang; Kilani, Y.; Lee, J.H.M.; Stuckey, P. J.

    2006-01-01

    In this note we introduce the notion of islands for restricting local search. We show how we can construct islands for CNF SAT problems, and how much search space can be eliminated by restricting search to the island.

  7. Beautiful hainan island

    Institute of Scientific and Technical Information of China (English)

    汪伦

    2002-01-01

    Hainan Island is the second largest island in China. It is situated on the Nanhai Sea(South China Sea) and faces Guangdong Province across Qiongzhou Strait (海峡).Hainan Province was established (建立)in 1988. It consists of Hainan Island, Xisha Islands, Zhongsha Islands, Nansha Islands and the vast sea areas around them.Its total area is 340,000 km2.

  8. The Urban Heat Island Phenomenon and Potential Mitigation Strategies

    Science.gov (United States)

    Estes, Maurice G., Jr.; Gorsevski, Virginia; Russell, Camille; Quattrochi, Dale; Luvall, Jeffrey

    1999-01-01

    A survey of urban heat island research is provided to describe how heat islands develop, urban landscape and meteorological characteristics that facilitate development, use of aircraft remote sensing data, and why heat islands are of interest to planners, elected officials, and the public. The roles of the National Aeronautics and Space Administration (NASA), the Environmental Protection Agency (EPA), other federal agencies, national laboratories and universities, state and local governments, and non-governmental organizations (NGOS) in studying the urban heat island effect and developing mitigation strategies are explored. Barriers that hamper mitigation efforts and case studies in Atlanta and Salt Lake City are discussed.

  9. Late Holocene sea-level change and reef-island evolution in New Caledonia

    OpenAIRE

    Yamano, H.; Cabioch, Guy; Chevillon, Christophe; Join, J. L.

    2014-01-01

    In New Caledonia, numerous rays are distributed on platform reefs in the southwest lagoon behind the barrier reef. At Mba Island, a vegetated sand cay in this area, we examined Holocene sea-level change, and reef development and evolution. The late Holocene sea-level curve for the area was updated using newly found fossil microatolls. Component-specific dating of foraminifera tests in the island sediment provided reliable ages of island formation. Mba Island initially formed around similar to...

  10. Modification of field emission resonances by Cu and Cu/Ag islands on Ag(100)

    Energy Technology Data Exchange (ETDEWEB)

    Zaum, Christopher; Morgenstern, Karina [Institut fuer Festkoerperphysik, Abteilung ATMOS, Gottfried Wilhelm Leibniz Universitaet, Appelstr. 2, D-30167 Hannover (Germany)

    2011-07-01

    We deposited Cu islands containing 10 to 500 atoms on a clean Ag(100) surface at room temperature and investigated their electronic structure by STS spectroscopy with a low temperature scanning tunneling microscope. Islands containing less than 50 atoms per islands are pure Cu islands, while islands at sizes above 80 atoms per island are Cu/Ag alloy islands. STS measurements reveal that these two island types have a different impact on the field emission resonances (FERs) of the Ag(100) surface. While the observed modifications for large islands are marginal, noticeable shifts of the FERs occur for small islands. These different results in STS spectroscopy are discussed with respect to the different work functions of pure and alloyed islands. Such STS measurements could therefore be used to determine the composition of surface alloys with high spatial resolution.

  11. Island Formation: Constructing a Coral Island

    Science.gov (United States)

    Austin, Heather; Edd, Amelia

    2009-01-01

    The process of coral island formation is often difficult for middle school students to comprehend. Coral island formation is a dynamic process, and students should have the opportunity to experience this process in a synergistic context. The authors provide instructional guidelines for constructing a coral island. Students play an interactive role…

  12. Sprache als Barriere (Language as a Barrier)

    Science.gov (United States)

    Mattheier, Klaus

    1974-01-01

    The concept of language barrier has its derivations in the fields of dialectology, sociology and psychology. In contemporary usage however, the concept has two meanings i.e. regional-cultural barrier and socio-cultural barrier. (Text is in German.) (DS)

  13. Recent hydrogeologic study of the Vis island

    Directory of Open Access Journals (Sweden)

    Janislav Kapelj

    2002-12-01

    Full Text Available The Vis Island belongs to the group of the Middle Dalmatian islands. It comprises an area of about 90.2 km2. Morphologically, three belts of highlands and two depressions with karst poljes are significant. The highest point on the island is Hum with 587 m a.s.l. theisland’s water supply is organized from the water-supply station “Korita”, situated in the central part of island, in tectonically formed depression. There are two additional capturedobjects: the well K-1 above the Komiža town and the spring “Pizdica”. The most important hydrogeological role on the island have two hydrogeological barriers, one in the KomižaBay, completely made of impermeable igneous and clastic rocks, and another one, the recently recognized relative barrier in the area of Dra~evo, Plisko and Velo polje. Since the island karst aquifer is in permanent dynamic relation with seawater, classical geologic,structural and hydrogeologic investigations have been performed with application of hydrogeochemical methods taking into account the natural chemical tracer content of groundwater and its variations in different hydrologic and vegetation conditions. Precipitationregime is very unfavorable with regard to the recharging of island’s aquifer, because dry periods are usually very long. During the summer tourist season, when the number of inhabitants and fresh water consumption considerably increase, amounts of island’sgroundwater suitable for water supply and irrigation rapidly decrease. Sometimes, insufficient quantity of fresh water on the Vis Island causes restrictions. Concerning the development of tourist potential and the present agricultural activities, summer lack ofwater is a serious restrictive factor. Some results of the performed hydrogeological study, important as a basis for island’s fresh water potential assessment, will be presented.

  14. Barrier response to Holocene sea-level rise

    DEFF Research Database (Denmark)

    Pejrup, Morten; Andersen, Thorbjørn Joest; Johannessen, Peter N;

    Normally it is believed that sea-level rise causes coastal barrier retreat. However, sea-level is only one of the parameters determining the long term coastal development of barrier coasts. Sediment supply is an equally important determinant and may overshadow the effects of sea-level rise...... show quite different responses to sea-level rise. The southernmost island Rømø has survived 17 m of sea-level rise at the same position illustrating the control from sediment supply; whereas the northernmost island Skallingen has shifted its position several times during the same period indicating a...... much stronger component of sea-level control. The distance between the islands is only 50 km, and therefore our study shows that prediction of barrier development during a period of rising sea level may be more complicated than formerly believed....

  15. Cathode-Electrolyte Interfaces with CGO Barrier Layers in SOFC

    DEFF Research Database (Denmark)

    Knibbe, Ruth; Hjelm, Johan; Menon, Mohan;

    2010-01-01

    10) barrier layer, the other had a barrier layer deposited by pulsed laser deposition (PLD) CGO10. Scanning electron microscopy, transmission electron microscopy (TEM), and electron backscattered diffraction (EBSD) investigations conclude that the major source of the cell performance difference is...... attributed to CGO–YSZ interdiffusion in the sprayed-cosintered barrier layer. From TEM and EBSD work, a dense CGO10 PLD layer is found to be deposited epitaxially on the 8YSZ electrolyte substrate—permitting a small amount of SrZrO3 formation and minimizing CGO–YSZ interdiffusion....

  16. Early Stages of the Chemical Vapor Deposition of Pyrolytic Carbon Investigated by Atomic Force Microscopy

    OpenAIRE

    Pfrang, Andreas; WAN Yong-Zhong; Schimmel, Thomas

    2009-01-01

    The early stages of chemical vapor deposition of pyrolytic carbon on planar silicon substrates were studied by the atomic force microscopy-based technique of chemical contrast imaging. Short deposition times were chosen to focus on the early stages of the deposition process, and three different types of nucleation were found: random nucleation of single islands, nucleation of carbon islands along lines and secondary nucleation which corresponds to the nucleation of carbon islands at the edges...

  17. Researching Pacific island livelihoods:

    DEFF Research Database (Denmark)

    Egelund Christensen, Andreas; Mertz, Ole

    2010-01-01

    Small island literature is vast in focus and aim, and is rooted in many different disciplines. The challenge is to find common grounds for researching small islands conceptually and theoretically. The aim of this article is to comment on how to research small islands, including a discussion on...... contemporary theories of nissology and conceptual analytical frameworks for island research. Through a review of selected case-study-based island literature on changing livelihoods coming out of the South Pacific, we wish to illustrate and discuss advantages of finding common grounds for small island studies...

  18. Breaching vulnerability of coastal barriers under effects of tropical cyclones: a model study on the Hue lagoon - Vietnam

    NARCIS (Netherlands)

    Tuan, T.Q.; Stive, M.J.F.; Verhagen, H.J.

    2006-01-01

    Under effects of tropical cyclones, the coast is subjected to attack both by surge and wave from the sea and by flooding from the bay. These forces pose a serious breaching threat to natural sea-defence works such as barrier spits, barrier islands, lagoon barriers, etc. on the coast. Unintended brea

  19. A Comprehensive Study on Coastline Process and Sedimentary Dynamics, Sardinera Beach, Mona Island, P.R.

    Science.gov (United States)

    Rodriguez-Delga, A. M.; Ramirez, W. R.

    2008-12-01

    Sardinera beach in Mona Island, Puerto Rico, has a great recreational and ecological value and is an important research place to gather information on shoreline processes in an area far from the main land and with only scarce man made influences. Beach rock exposures present along the shoreline in Sardinera Beach have increased considerably during the last decade. A new management plan is being developed for Mona Island and the Department of Natural Resources (DNRA) of Puerto Rico wants to better understand the beach sand dynamics on this and other Mona Island beaches. This research includes field and laboratory work that characterize coastal sedimentary processes and helps to better understand the shoreline changes as well as seasonal variations in sand movement and composition. This work also establish the logistics and methodology basis for further studies that will expand to other Mona Island beaches. Benchmarks, GPS coordinates, and landmarks were used to establish ten permanent beach profiles along Sardinera Beach. Beach profiles were (and will be) measured monthly. Sardinera Beach sands are composed mostly of carbonate (CaCO3) components, products of the combination of biological, chemical and diagenetic processes, high grade of micritization, and of lithic limestone fragments. Sand composition differences between Sardinera Beach, the Mona Shelf and adjacent beach, reef crest and reef lagoon systems suggest Sardinera sands are not replenished by the modern marine components produced in these environments. The input of "fresh bioclasts" in this beach seems to be limited by natural (beach rock) and mane made (dock) barriers along the shore and by alteration in the current patterns produced by the man made aperture of the reef. Sardinera's micritized and recrystalized sand deposits seem to have been re-transported between the reefal lagoon and the beach. Sand volume analysis indicates a total sand loss of 1,322 m3 between the months of September to April

  20. Shemya Island prehistory

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The 752 artifacts described in this paper are from 5 sites on Shemya Island. Artifactual evidence suggests the island had a small resident population and was...

  1. Method Producing an SNS Superconducting Junction with Weak Link Barrier

    Science.gov (United States)

    Hunt, Brian D. (Inventor)

    1999-01-01

    A method of producing a high temperature superconductor Josephson element and an improved SNS weak link barrier element is provided. A YBaCuO superconducting electrode film is deposited on a substrate at a temperature of approximately 800 C. A weak link barrier layer of a nonsuperconducting film of N-YBaCuO is deposited over the electrode at a temperature range of 520 C. to 540 C. at a lower deposition rate. Subsequently a superconducting counter-electrode film layer of YBaCuO is deposited over the weak link barrier layer at approximately 800 C. The weak link barrier layer has a thickness of approximately 50 A and the SNS element can be constructed to provide an edge geometry junction.

  2. Island political economy

    OpenAIRE

    Bertram, Geoffrey; Poirine, Bernard

    2007-01-01

    International audience In this chapter we build on the observation that island economies, and especially small ones (population below one million), exhibit a remarkably wide range of economic structures built on a correspondingly wide range of development strategies. Common elements of "islandness" may serve to define island economies as a general class, but there clearly exist several distinct "species" within that class, and a corresponding menu of strategic options open to islander comm...

  3. High-resolution reconstruction of a coastal barrier system

    DEFF Research Database (Denmark)

    Fruergaard, Mikkel; Andersen, Thorbjørn Joest; Nielsen, Lars Henrik;

    2015-01-01

    This study presents a detailed reconstruction of the sedimentary effects of Holocene sea-level rise on a modern coastal barrier system (CBS). Increasing concern over the evolution of CBSs due to future accelerated rates of sea-level rise calls for a better understanding of coastal barriers respon...... accumulation shows considerable variation with periods of rapid sediment deposition and periods of non-deposition or erosion resulting in a highly punctuated sediment record....

  4. Sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    Three overall factors are necessary for formation of uranium deposits in sandstone: a source of uranium, host rocks capable of transmitting uranium-bearing solutions, and a precipitant. Possible sources of uranium in sandstone-type deposits include groundwaters emanating from granitic highlands, arkosic sediments, tuffaceous material within or overlying the host rocks, connate fluids, and overlying black shales. The first three sources are considered the most likely. Host rocks are generally immature sandstones deposited in alluvial-fan, intermontane-basin or marginal-marine environments, but uranium deposits do occur in well-winnowed barrier-bar or eolian sands. Host rocks for uranium deposits generally show coefficients of permeability on the order of 1 to 100 gal/day/ft2. Precipitants are normally agents capable of reducing uranium from the uranyl to the uranous state. The association of uranium with organic matter is unequivocal; H2S, a powerful reductant, may have been present at the time of formation of some deposits but may go unnoticed today. Vanadium can serve to preserve the tabular characteristics of some deposits in the near-surface environment, but is considered an unlikely primary precipitant for uranium. Uranium deposits in sandstone are divided into two overall types: peneconcordant deposits, which occur in locally reducing environments in otherwise oxidized sandstones; and roll-type deposits, which occur at the margin of an area where an oxidized groundwater has permeated an otherwise reduced sandstone. Uranium deposits are further broken down into four subclasses; these are described

  5. 76 FR 55107 - Draft Environmental Impact Statement for General Management Plan, Gulf Islands National Seashore...

    Science.gov (United States)

    2011-09-06

    ... opportunities. The seashore would be managed as an outdoor classroom for exploring the natural and human history of the Gulf of Mexico's barrier islands and coastal environments. Interpretive programs would focus... islands have played in the last 5,000 years of historic human occupation. Alternative 4 would expand...

  6. An indigenous soil classification system for Bellona Island - a raised atoll in the Solomon Islands

    DEFF Research Database (Denmark)

    Elberling, Bo; Breuning-Madsen, Henrik; Bruun, Thilde Bech

    2010-01-01

    developed by local farmers on the island of Bellona, Solomon Islands. The definitions of the different soil types are described and the principles of the classification system and the applicability of ethnopedology in soil surveys are discussed. Based on interviews with about 20 per cent of the farmers...... on the island as well as standard soil chemical and physical determinations on main soil types, an evaluation of the soil types for cultivation of various crops is carried out. The soils on Bellona are developed on oolitic or clayey phosphate-rich deposits forming the basis for the agriculture production...... on the island. The Bellonese soil classification system is mainly based on the physical properties of the humus-containing top layer. Subsoil layers are only used for classification if they are very close to the surface and may be mixed with the topsoil. Results show a general agreement among farmers, who...

  7. The distribution of the vascular plants on the North Frisian Island, Amrum

    OpenAIRE

    Quentin Groom

    2014-01-01

    Abstract Amrum is a small barrier island on the north-west coast of Germany. The distribution of vascular plants was examined by surveying their 1km2 grid square occupancy across the whole island. These data were used in a study on the recent vegetation change in the island. These data include 3786 observations of 450 taxa collected in two surveys in 2007 and 2008.

  8. Hydrogen permeation barrier development and characterisation

    International Nuclear Information System (INIS)

    The control of hydrogen losses in a hydrogen production industrial plant is of crucial importance especially for its safety implications. The high temperatures and pressures required in hydrogen production processes as well as the corrosive process fluids can enhance drastically the intrinsic permeation characteristics of metals and alloys. To reduce hydrogen permeation and a subsequent mechanical degradation of structural materials, hydrogen permeation barriers can be applied. As shown by previous works performed in the frame of the European Fusion Technology Programme, satisfactory hydrogen permeation reductions were achieved using alumina-rich coatings. Several deposition techniques were investigated and coatings were obtained by chemical vapour deposition (CVD) and hot dipping, and these processes seem to have exhibited a better TPB efficiency with respect to the coatings obtained by spray techniques. This work contains a review of the deposition techniques and the efficiency of the different hydrogen permeation barriers developed in the frame of the EU Fusion Programme. (author)

  9. The lofting of Western Pacific regional aerosol by island thermodynamics as observed around Borneo

    Directory of Open Access Journals (Sweden)

    N. H. Robinson

    2012-01-01

    expected to increase aerosol lifetimes in the lower free troposphere downwind, as they are above the boundary layer and therefore less likely to be lost by wet or dry deposition. It is also likely to change the role they play in the semi-direct and direct aerosol effects. The long chain of islands extending from Malaysia to Australia may all similarly be expected to present an orographic barrier to low level mean flow. This would lead to significant transport of aerosol into the tropical free troposphere across the Western Pacific region.

  10. Barrier Certificates Revisited

    OpenAIRE

    Dai, Liyun; Gan, Ting; Xia, Bican; Zhan, Naijun

    2013-01-01

    A barrier certificate can separate the state space of a con- sidered hybrid system (HS) into safe and unsafe parts ac- cording to the safety property to be verified. Therefore this notion has been widely used in the verification of HSs. A stronger condition on barrier certificates means that less expressive barrier certificates can be synthesized. On the other hand, synthesizing more expressive barrier certificates often means high complexity. In [9], Kong et al consid- ered how to relax the ...

  11. Birds observed at Shemya Island, Aleutian Islands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers Shemya Island bird surveys. The reports outline migrant bird activity during August 31 to October 3, 1977. The purpose of the study was to survey...

  12. Paradise Islands? Island States and Environmental Performance

    Directory of Open Access Journals (Sweden)

    Sverker C. Jagers

    2016-03-01

    Full Text Available Island states have been shown to outperform continental states on a number of large-scale coordination-related outcomes, such as levels of democracy and institutional quality. The argument developed and tested in this article contends that the same kind of logic may apply to islands’ environmental performance, too. However, the empirical analysis shows mixed results. Among the 105 environmental outcomes that we analyzed, being an island only has a positive impact on 20 of them. For example, island states tend to outcompete continental states with respect to several indicators related to water quality but not in aspects related to biodiversity, protected areas, or environmental regulations. In addition, the causal factors previously suggested to make islands outperform continental states in terms of coordination have weak explanatory power in predicting islands’ environmental performance. We conclude the paper by discussing how these interesting findings can be further explored.

  13. Using Wavelet Decomposition to Assess the Development of Padre Island National Seashore, Texas, USA

    Science.gov (United States)

    Wernette, P. A.; Weymer, B. A.; Houser, C.; Bishop, M. P.; Everett, M. E.; Reece, R.

    2015-12-01

    This study examines the relationship between modern barrier island morphology and offshore bathymetry to better understand the development history of Padre Island National Seashore (PAIS), Texas, USA. The widely accepted hypothesis for the development of PAIS is that the dunes on the mainland were partially submerged during the Holocene transgression, resulting in distinct islands that eventually coalesced by sediment transported alongshore; however, this hypothesis does not follow the development history of other barrier islands throughout the Gulf of Mexico. This study uses electromagnetic inductance (EMI) surveys, bathymetric contours, and island morphometrics to better understand the development of PAIS. A 100km long EMI survey was conducted to aid in identifying infilled subsurface paleochannels that dissect the island. Bathymetric contours were extracted from NOAA digital elevation models (DEMs) up to 7km offshore by offsetting the shoreline east in 1km intervals. Island width and volume, beach width and volume, and dune height and volume were extracted from a 100 km LiDAR-derived digital elevation model (DEM) using an automated approach. Apparent conductivity at all three frequencies (from the EMI survey), bathymetric contours, and island morphometrics were subsequently decomposed using a continuous wavelet transformation (CWT). Beach width, dune height, and dune volume exhibit a very similar waveform that coincides spatially with an inflection point in the waveform for the offshore bathymetric contours. Portions of the island proximal to the infilled paleochannels tend to have a wider beach and taller/higher volume dunes. The high degree of similarity between the subsurface paleochannels, offshore bathymetry, and island morphometrics support a new theory of development for PAIS. We argue that PAIS is not a series of partially submerged relict dunes, as previously proposed, rather that framework geology is an important factor affecting modern island

  14. Catalyst deposition for the preparation of carbon nanotubes

    DEFF Research Database (Denmark)

    2013-01-01

    covered nano patterned surface is configured to ensure that no more than a single island of catalyst is formed on each plateau, so that a sub sequent growth of carbon nanotubes from the deposited islands result in that no more than a single carbon nanotube is grown from each plateau....

  15. Mapping Depositional Facies on Great Bahama Bank: An Integration of Groundtruthing and Remote Sensing Methods

    Science.gov (United States)

    Hariss, M.; Purkis, S.; Ellis, J. M.; Swart, P. K.; Reijmer, J.

    2013-12-01

    Great Bahama Bank (GBB) has been used in many models to illustrate depositional facies variation across flat-topped, isolated carbonate platforms. Such models have served as subsurface analogs at a variety of scales. In this presentation we have integrated Landsat TM imagery, a refined bathymetric digital elevation model, and seafloor sample data compiled into ArcGIS and analyzed with eCognition to develop a depositional facies map that is more robust than previous versions. For the portion of the GBB lying to the west of Andros Island, the facies map was generated by pairing an extensive set of GPS-constrained field observations and samples (n=275) (Reijmer et al., 2009, IAS Spec Pub 41) with computer and manual interpretation of the Landsat imagery. For the remainder of the platform, which lacked such rigorous ground-control, the Landsat imagery was segmented into lithotopes - interpreted to be distinct bodies of uniform sediment - using a combination of edge detection, spectral and textural analysis, and manual editing. A map was then developed by assigning lithotopes to facies classes on the basis of lessons derived from the portion of the platform for which we had rigorous conditioning. The new analysis reveals that GBB is essentially a very grainy platform with muddier accumulations only in the lee of substantial island barriers; in this regard Andros Island, which is the largest island on GBB, exerts a direct control over the muddiest portion of GBB. Mudstones, wackestones, and mud-rich packstones cover 7%, 6%, and 15%, respectively, of the GBB platform top. By contrast, mud-poor packstones, grainstones, and rudstones account for 19%, 44%, and 3%, respectively. Of the 44% of the platform-top classified as grainstone, only 4% is composed of 'high-energy' deposits characterized by the development of sandbar complexes. The diversity and size of facies bodies is broadly the same on the eastern and western limb of the GBB platform, though the narrower eastern

  16. Sputtering at grazing ion incidence: Influence of adatom islands

    International Nuclear Information System (INIS)

    When energetic ions impinge at grazing incidence onto an atomically flat terrace, they will not sputter. However, when adatom islands (containing N atoms) are deposited on the surface, they induce sputtering. We investigate this effect for the specific case of 83 deg. -incident 5 keV Ar ions on a Pt (111) surface by means of molecular-dynamics simulation and experiment. We find that - for constant coverage Θ - the sputter yield has a maximum at island sizes of N congruent with 10-20. A detailed picture explaining the decline of the sputter yield toward larger and smaller island sizes is worked out. Our simulation results are compared with dedicated sputtering experiments, in which a coverage of Θ=0.09 of Pt adatoms are deposited onto the Pt (111) surface and form islands with a broad distribution around a most probable size of N congruent with 20.

  17. The bounding-surfaces record of a barrier spit from Huangqihai Lake, North China: implications for coastal barrier boundary hierarchy

    Science.gov (United States)

    Shan, Xin; Yu, Xinghe; Clift, Peter D.; Wang, Tianyi; Tan, Chengpeng; Jin, Lina

    2016-09-01

    Ground-penetrating radar and trenching studies of a barrier spit on the north shore of Huangqihai Lake were made, that reveal important implications for the coastal washover barrier boundary hierarchy and interpretations of this depositional record. A four-fold hierarchy bounding-surface model, representing different levels of impact and genesis, is defined. Each level of the hierarchy is enclosed by a distinct kind of surface characterized by different ground-penetrating radar reflection features, sedimentary characteristics (color, grain size, sorting, rounding and sedimentary structures) and origin. We suggest that this hierarchical model can be applied to any coastal washover barrier deposits.

  18. Safety-barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    Safety-barrier diagrams and the related so-called "bow-tie" diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation with other methods such as fault trees and Bayesian networks...... are discussed. A simple method for quantification of safety-barrier diagrams is proposed, including situations where safety barriers depend on shared common elements. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information...... from risk analysis with operational safety management....

  19. Safety-barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2007-01-01

    Safety-barrier diagrams and the related so-called "bow-tie" diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation with other methods such as fault trees and Bayesian networks...... are discussed. A simple method for quantification of safety-barrier diagrams is proposed, including situations where safety barriers depend on shared common elements. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information...... from risk analysis with operational safety management....

  20. Safety- barrier diagrams

    DEFF Research Database (Denmark)

    Duijm, Nijs Jan

    2008-01-01

    Safety-barrier diagrams and the related so-called 'bow-tie' diagrams have become popular methods in risk analysis. This paper describes the syntax and principles for constructing consistent and valid safety-barrier diagrams. The relation of safety-barrier diagrams to other methods such as fault...... trees and Bayesian networks is discussed. A simple method for quantification of safety-barrier diagrams is proposed. It is concluded that safety-barrier diagrams provide a useful framework for an electronic data structure that integrates information from risk analysis with operational safety management....

  1. Filamentary and diffuse barrier discharges

    International Nuclear Information System (INIS)

    Barrier discharges, sometimes also referred to as dielectric-barrier discharges or silent discharges, are characterized by the presence of at least one insulating layer in contact with the discharge between two planar or cylindrical electrodes connected to an ac power supply. The main advantage of this type of electrical discharge is, that non-equilibrium plasma conditions in atmospheric-pressure gases can be established in an economic and reliable way. This has led to a number of important applications including industrial ozone generation, surface modification of polymers, plasma chemical vapor deposition, excitation of CO2 lasers, excimer lamps and, most recently, large-area flat plasma display panels. Depending on the application, the width of the discharge gap can range from less than 0.1 mm to about 100 mm and the applied frequency from below line frequency to several gigahertz. Typical materials used for the insulating layer (dielectric barrier) are glass, quartz, ceramics but also thin enamel or polymer layers

  2. Surface stability test plan for protective barriers

    International Nuclear Information System (INIS)

    Natural-material protective barriers for long-term isolation of buried waste have been identified as integral components of a plan to isolate a number of Hanford defense waste sites. Standards currently being developed for internal and external barrier performance will mandate a barrier surface layer that is resistant to the eolian erosion processes of wind erosion (deflation) and windborne particle deposition (formation of sand dunes). Thus, experiments are needed to measure rates of eolian erosion processes impacting those surfaces under different surface and climatological conditions. Data from these studies will provide information for use in the evaluation of selected surface layers as a means of providing stable cover over waste sites throughout the design life span of protective barriers. The multi-year test plan described in this plan is directed at understanding processes of wind erosion and windborne particle deposition, providing measurements of erosion rates for models, and suggesting construction materials and methods for reducing the effect of long-term eolian erosion on the barrier. Specifically, this plan describes possible methods to measure rates of eolian erosion, including field and laboratory procedure. Advantages and disadvantages of laboratory (wind tunnel) tests are discussed, and continued wind tunnel tests are recommended for wind erosion studies. A comparison between field and wind tunnel erosive forces is discussed. Plans for testing surfaces are described. Guidance is also presented for studying the processes controlling sand dune and blowout formation. 24 refs., 7 figs., 3 tabs

  3. Piram island: Pirates Fort in the Gulf of Khambat

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Bhatt, B.K.

    Gogha. The island has a lighthouse dating to the early 20 th century, which was rebuilt in the last quarter of the same century. Presently, Piram Island is thickly covered with forest and archaeological remains. The lighthouse has been renovated... containing drifted mammalian bones and the mud-cracks in the clays, diagnostic of tidal flats, point to the deposition of Piram Beds in a tidal estuarine environment. ARCHAEOLOGICAL EXPLORATIONS Being situated close to the famous historical sites...

  4. Darwin and the island

    OpenAIRE

    Fox, Justin Daniel.

    1995-01-01

    This thesis examines the fictional island and assesses the impact of Darwinism on the genre. I show how islands have been a recurring feature in European literature, fictional spaces where authors create a microcosm in which they satirise, criticise or hold up a mirror to their own society. I argue that traditonal Utopian islands are static realms and that through the introduction of evolution (Darwin and Wallace made their most important discoveries regarding the mechanism of...

  5. International Uranium Resources Evaluation Project (IUREP) national favourability studies: Gilbert and Ellice Islands

    International Nuclear Information System (INIS)

    The Gilbert and Ellice Islands occupy about 1200 square kilometers of islands scattered over nearly 7,000,000 square kilometers of the Pacific Ocean, All are coral islands except Ocean Island which is of volcanic origin and is a very important producer of phosphate rock. The geology of the Gilbert and Ellice Islands is not considered favourable for uranium disposition, but a small by-product resource in category one is assigned on the basis of the possibility that the phosphate deposits contain a small quantity of uranium. (author)

  6. Description of Heliocypha vantoli spec. nov. from Siberut in the Mentawai Islands (Odonata: Chlorocyphidae).

    Science.gov (United States)

    Hämäläinen, Matti

    2016-01-01

    Heliocypha vantoli Hämäläinen, spec. nov. [holotype ♂ from Indonesia, Mentawai Islands (off Sumatra), Siberut Island, 29-31 January 2013, deposited at RMNH, Leiden, The Netherlands] is described and illustrated for both sexes and compared with the Heliocypha species found in Sumatra and adjacent small islands. Notes on the Odonata fauna of the Mentawai Islands are also provided. Euphaea aspasia Selys, 1853 (Euphaeidae) is recorded as new to these islands; differences in the colour pattern of the Siberut and mainland Sumatran specimens are briefly discussed. PMID:27394205

  7. Lessons from the Rhode Island banking crisis

    OpenAIRE

    Thomas E. Pulkkinen; Eric S. Rosengren

    1993-01-01

    The failure of the Rhode Island Share and Deposit Indemnity Corporation (RISDIC), a private insurance fund, and the closure of its 45 remaining member institutions froze the accounts of 300,000 individuals and 10 percent of all deposits in the state. While the closure of two institutions triggered RISDIC’s demise, flaws in both design and management had set the stage for failure and are the focus of this article. The authors group RISDIC’s problems into three categories: risk concentrations, ...

  8. Method for applying a diffusion barrier interlayer for high temperature components

    Science.gov (United States)

    Wei, Ronghua; Cheruvu, Narayana S.

    2016-03-08

    A coated substrate and a method of forming a diffusion barrier coating system between a substrate and a MCrAl coating, including a diffusion barrier coating deposited onto at least a portion of a substrate surface, wherein the diffusion barrier coating comprises a nitride, oxide or carbide of one or more transition metals and/or metalloids and a MCrAl coating, wherein M includes a transition metal or a metalloid, deposited on at least a portion of the diffusion barrier coating, wherein the diffusion barrier coating restricts the inward diffusion of aluminum of the MCrAl coating into the substrate.

  9. Tanzania - Mafia Island Airport

    Data.gov (United States)

    Millenium Challenge Corporation — The evaluation design and subsequent data gathering activities will address the following key research questions: a) Has the Mafia Island Airport Upgrade Project...

  10. Shape of heteroepitaxial island determined by asymmetric detachment

    Science.gov (United States)

    Saito, Yukio; Kawasaki, Ryo

    2008-02-01

    Square lattice gas models for heteroepitaxial growth are studied by means of kinetic Monte Carlo simulations, in order to find a possible origin of anisotropic island shape observed in growth experiments of long organic molecules. When deposited molecules form clusters irreversibly at their encounter during surface diffusion, islands grow in a ramified dendritic shape, similar to DLA. Introduction of molecular detachment from edges makes islands compact with smooth edges. Tilting of adsorbed long molecules or steps in a vicinal substrate may induce orientation dependence in the detachment rate of edge molecules from an island. In simulations with orientation-dependent detachment rates, a clear anisotropy in an island shape is observed. Shape anisotropy on a vicinal substrate is enhanced as steps get dense, in agreement to the experimental observation.

  11. Scaling of Island Growth in Pb Overlayers on Cu(001)

    OpenAIRE

    Li, Wei; Vidali, Gianfranco; Biham, Ofer

    1993-01-01

    The growth and ordering of a Pb layer deposited on Cu(001) at 150 K has been studied using atom beam scattering. At low coverage, ordered Pb islands with a large square unit cell and nearly hexagonal internal structure are formed. This is a high order commensurate phase with 30 atoms in the unit cell. From the measurement of the island diffraction peak profiles we find a power law for the mean island - size versus coverage with an exponent $n=0.54 \\pm 0.03$. A scaling behavior of growth is co...

  12. Assesing Geographic Isolation of the Galapagos Islands

    Science.gov (United States)

    Orellana, D.; Smith, F.

    2016-06-01

    The Galapagos Archipelago is one of the most important ecological spots in the planet due its unique biodiversity, active geology, and relatively well-preserved ecosystems. These characteristics are strongly based on the geographical isolation of the islands. On the one hand this isolation allowed the evolution processes that gave the islands their international fame and on the other hand it kept them from major human impacts that affected the vast majority of the Earth's surface. Galapagos' geographical isolation is therefore of mayor value, but it is rapidly diminishing due to the increase of marine and air transportation among islands and with the rest of the world. This increased accessibility implies enhanced risks for the ecological dynamics on the archipelago (e.g. increased risk of biological invasions, uncontrolled tourism growth, more water and energy consumption). Here, we introduce a general accessibility model to assess geographical isolation of the Galapagos Islands. The model aims to characterize accessibility in terms of human mobility by evaluating travel time to each point of the archipelago using all available transportation modalities. Using a multi criteria cost surface for marine and land areas, we estimated travel time for each surface unit using the fastest route and mode of transportation available while considering several friction factors such as surface type, slope, infrastructure, transfer points, legal restrictions, and physical barriers. We created maps to evaluate the isolation of different islands and places, highlighting the potential risks for several habitats and ecosystems. The model can be used for research and decision-making regarding island conservation, such as estimating spreading paths for invasive species, informing decisions on tourism management, and monitoring isolation changes of sensitive ecosystems.

  13. Assessment of Groundwater Resources of Dauphin Island and its Connection to Urban Sprawl and Economic Growth

    Science.gov (United States)

    Petty, K. S.

    2009-12-01

    Dauphin Island is a barrier island about 28 miles south of Mobile, Alabama. The island relies heavily on the shallow aquifer underlying the barrier island. Worldwide, the largest volume of water used for human consumption and use comes from groundwater resources. On barrier islands such as Dauphin Island, the proportion of water used by humans coming from groundwater resources is even higher. Additionally, tourism is very important to the economy of Dauphin Island, and the hotels and tourist attractions rely on groundwater. Because of the large influx of people there are peaks in water demand during tourist season. The goal of this project is to quantify the impacts of urban growth on the aquifer and provide an estimate for sustainable withdrawal rates. The project will be carried out in two main phases. In the first phase a water resource assessment and analysis will be conducted using the SEAWAT model. SEAWAT simulates three-dimensional variable-density ground-water flow coupled with multi-species solute and heat transport. In the second phase the calibrated groundwater model for the island will be used to perform a scenario analysis which would help link groundwater availability with urban sprawl. In this paper we will describe the research methodology and procedures that will be used in the project.

  14. Chemical and Mineralogical Features of Smectite from the Morron de Mateo Bentonite Deposit (Cabo de Gata, Almeria) in Relation to the Parent Rocks and the Alteration Processes Occurred After the Bentonite Formation: Analogies and Implications for the Engineered Clayey Barrier of a Deep Geological Rad waste Repository

    International Nuclear Information System (INIS)

    The Morron de Mateo bentonite deposit is being studied as a natural analogue of the thermal and geochemical effects on the clayey barrier of a Deep Geological Rad waste Repository (DGRR) after its closure, in relation to the radioactive decay of the fission products and the container corrosion. This bentonite deposit and their host rocks were intruded by a rhyodacitic volcanic dome that induced a hydrothermal metasomatic process affecting the bioclastic calcarenite beds close to the dome. Bentonite from the NE sector of the deposit have been chemically and mineralogically characterized. Pyroclastic rocks (white tuffs), epyclastic rocks (mass flow) and andesitic breccia all of them hydrothermally altered, have been studied at the site. Samples are composed of feldspars, quartz and amphybols, as inherited minerals, and phyllosilicates, zeolites, crystoballite and calcite, as new formed minerals. White tuffs have the highest phyllosilicate contents, mainly dioctahedral smectite of montmorillonite type. Epyclastic rocks and andesitic breccia have a highest proportion of inherited minerals, the new formed phillosilicates being di octahedral smectite of beidellite type and an ordered interlayer chlorite/smectite mineral, of corrensite type. Smectite from the epyclastic rocks have higher Fe and Mg contents and chemical variability, as a consequence of nature of their parent rocks. The presence of corrensite in the epyclastic rocks suggests that in the Morron de Mateo area a propilitic alteration process occurred after bentonite formation, which transformed Fe-Mg-rich smectite into corrensite. This transformation was probably favoured by the sub volcanic intrusion, which also produced a temperature increase in the geological media and a supply of Fe-Mg-rich solutions, which also were the responsible for the metasomatic transformations observed in the calcarenite beds. (Author) 57 refs

  15. Formation and collapse of internal transport barrier

    International Nuclear Information System (INIS)

    A theoretical model of internal transport barrier (ITB) is developed. The transport model based on the self-sustained turbulence theory of the current-diffusive ballooning mode is extended to include the effects of ExB rotation shear. Delayed formation of ITB is observed in transport simulations. The influence of finite gyroradius is also discussed. Simulation of the current ramp-up experiment successfully described the radial profile of density, temperature and safety factor. A model of ITB collapse due to magnetic braiding is proposed. Sudden enhancement of transport triggered by overlaping of magnetic islands terminates ITB. The possibility of destabilizing global low-n modes is also discussed. (author)

  16. Selective Electroless Silver Deposition on Graphene Edges

    DEFF Research Database (Denmark)

    Durhuus, D.; Larsen, M. V.; Andryieuski, Andrei;

    2015-01-01

    We demonstrate a method of electroless selective silver deposition on graphene edges or between graphene islands without covering the surface of graphene. Modifications of the deposition recipe allow for decoration of graphene edges with silver nanoparticles or filling holes in damaged graphene...... on silica substrate and thus potentially restoring electric connectivity with minimal influence on the overall graphene electrical and optical properties. The presented technique could find applications in graphene based transparent conductors as well as selective edge functionalization and can be extended...

  17. The Cook Islands

    OpenAIRE

    World Bank

    2015-01-01

    This country note is produced is part of The Pacific Catastrophe Risk Assessment andFinancing Initiative (PCRAFI). The geographic spread of the Cook Islands poses logistical problems for any necessary post-disaster relief and response efforts. The events of 2005 demonstrated that the Cook Islands is extremely vulnerable to the threat of tropical cyclones (TCs): in the two months of Februar...

  18. Marine and Island Ecology.

    Science.gov (United States)

    Stephens, Lawrence J.; And Others

    1988-01-01

    Describes an ecology course which provides students with an opportunity to observe aquatic and terrestrial life in the Bahamas. States that students learn scientific methodology by measuring physical and chemical aspects of the island habitats. Provides information on the island, course description and objectives, transportation, facilities, and…

  19. St. Vincent Island Tour

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This letter, written by Charles Marks who lived on St. Vincent Island as a child, notes the changes he saw in the island when he visited in 1981. He notes that the...

  20. Back to Treasure Island

    Science.gov (United States)

    Shriki, Atara

    2011-01-01

    In this article, the author presents the Treasure Island problem and some inquiry activities derived from the problem. Trying to find where pirates buried a treasure leads to a surprising answer, multiple solutions, and a discussion of problem solving. The Treasure Island problem is an example of an inquiry activity that can be implemented in…

  1. Multilayer barrier films comprising nitrogen spacers between free-standing barrier layers

    Science.gov (United States)

    Granstrom, Jimmy Erik

    The air sensitivity of organic electronic devices has delayed the broad commercialization of the printed "plastics" electronics technology. The vacuum deposition methods used to fabricate multi-layers which fulfill the encapsulation requirements for plastic electronic devices are complex and expensive. Fully printed "plastic" electronics requires the development of encapsulation architectures which comprise solution deposited barriers and/or low-cost free-standing barrier films based on polymers, e.g. poly ethylene terephthalate (PET). One way to reach this goal is the insertion of contaminant-free (e.g. pure N2) gas-phase spacers between free-standing barrier films in a multilayer structure. The spacers themselves do not exhibit any barrier properties (diffusion of gas permeants in a gas phase is orders of magnitude faster than in a solid), but they delay the attainment of steady state. The spacer also reduces the chemical potential gradient across downstream barrier layers during the transient regime, reducing permeation rate to the device. Furthermore, if sorption is not fully equilibrated and introduces a kinetic barrier to transport, the additional sorption and desorption steps needed for permeant to reach the device may also slow the steady-state permeation rate. Encapsulation architectures utilizing both single-matrix (without nitrogen spacers) and multiple-matrix structures (with nitrogen spacers) were fabricated in this study, including Russian Doll structures utilizing pairs of free-standing barrier films and epoxy seals separated by nitrogen spacers. This structure enables the use of low-cost epoxy to attach two or more free-standing barrier films to a substrate with improved barrier performance. The performance of various Russian Doll encapsulations was evaluated with the calcium thin film optical transmission test, showing improved performance of the Russian doll configuration relative to a non-nested barrier/spacer architecture, and demonstrating that

  2. To Develop Nanostructured Thermal Barrier Coatings

    Science.gov (United States)

    Wang, Ning; Zhao, Weixun; Wang, Ping; Wei, Zheng

    Advanced turbine engines require the application of thermal barrier coatings (TBCs) to provide still higher reliability, thermal insulation effect and longer lifetime under harsh operating conditions. TBCs with nanostructure proved to be promising to deliver the desired property and performance. To exploit full potentials of the current widely used yttria-partially-stabilized zirconia (YSZ), nano-sized YSZ powders were developed and used as the ceramic source material. By controlling the deposition processes, novel TBCs with outstanding nanostructure such as nano-sized grains and pores were produced by atmospheric plasma spray (APS) and electron beam physical vapor deposition (EB-PVD), respectively. The incorporated nanostructure in TBCs resulted in substantial increase in thermal barrier effect and their lifetime. The long-term microstructure stability of the nanocoating was also investigated.

  3. Postglacial vegetation history of Mitkof Island, Alexander Archipelago, southeastern Alaska

    Science.gov (United States)

    Ager, Thomas A.; Carrara, Paul E.; Smith, Jane L.; Anne, Victoria; Johnson, Joni

    2010-03-01

    An AMS radiocarbon-dated pollen record from a peat deposit on Mitkof Island, southeastern Alaska provides a vegetation history spanning ˜12,900 cal yr BP to the present. Late Wisconsin glaciers covered the entire island; deglaciation occurred > 15,400 cal yr BP. The earliest known vegetation to develop on the island (˜12,900 cal yr BP) was pine woodland ( Pinus contorta) with alder ( Alnus), sedges (Cyperaceae) and ferns (Polypodiaceae type). By ˜12,240 cal yr BP, Sitka spruce ( Picea sitchensis) began to colonize the island while pine woodland declined. By ˜11,200 cal yr BP, mountain hemlock ( Tsuga mertensiana) began to spread across the island. Sitka spruce-mountain hemlock forests dominated the lowland landscapes of the island until ˜10,180 cal yr BP, when western hemlock ( Tsuga heterophylla) began to colonize, and soon became the dominant tree species. Rising percentages of pine, sedge, and sphagnum after ˜7100 cal yr BP may reflect an expansion of peat bog habitats as regional climate began to shift to cooler, wetter conditions. A decline in alders at that time suggests that coastal forests had spread into the island's uplands, replacing large areas of alder thickets. Cedars ( Chamaecyparis nootkatensis, Thuja plicata) appeared on Mitkof Island during the late Holocene.

  4. Formation of low-temperature self-organized nanoscale nickel metal islands

    OpenAIRE

    Carey, JD; Ong, LL; Silva, SRP

    2003-01-01

    The growth and evolution of nanometre-sized Ni metal islands deposited under low-temperature non-ultra high vacuum conditions as a function of metal layer thickness, growth temperature and time is reported. The temperature of formation of the islands has been intentionally kept low for possible applications in flat panel display technology and also to act as a catalyst for carbon nanotube growth. It is shown that the size and distribution of the islands depends critically on the annealing tem...

  5. Influence of capping on strain, composition and shape of SiGe islands

    International Nuclear Information System (INIS)

    The rearrangement of SiGe islands during the deposition of Si was studied by a combination of scanning tunneling microscopy, transmission electron microscopy and high-resolution X-ray diffraction. With increasing silicon capping of the islands, an increasing flattening accompanied by a rising intermixing could be determined. Using a finite element calculation, which served as an input for X-ray simulations, the strain distribution within the islands was obtained

  6. Assessment of Tropical Cyclone Induced Transgression of the Chandeleur Islands for Restoration and Wildlife Management

    Science.gov (United States)

    Reahard, Ross; Mitchell, Brandie; Brown, Tevin; Billiot, Amanda

    2010-01-01

    Barrier Islands are the first line of defense against tropical storms and hurricanes for coastal areas. Historically, tropical cyclonic events have had a great impact on the transgression of barrier islands, especially the Chandeleur Island chain off the eastern coast of Louisiana. These islands are of great importance, aiding in the protection of southeastern Louisiana from major storms, providing habitat for nesting and migratory bird species, and are part of the second oldest wildlife refuge in the country. In 1998, Hurricane Georges caused severe damage to the chain, prompting restoration and monitoring efforts by both federal and state agencies. Since then, multiple storm events have steadily diminished the integrity of the islands. Hurricane Katrina in 2005 thwarted all previous restoration efforts, with Hurricane Gustav in 2008 exacerbating island erosion and vegetation loss. Data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Moderate Resolution Imaging Spectroradiometer (MODIS), Landsat 2-4 Multispectral Scanner (MSS), and Landsat 5 Thematic Mapper (TM) will be utilized to detect land loss, island transgression, and vegetation change from 1979 to 2009. This study looks to create a more synoptic view of the transgression of the Chandeleur Islands and correlate weather and sea surface phenomena with erosion trends over the past 30 years, so that partnering organizations such as the Pontchartrain Institute for Environmental Sciences (PIES) can better monitor and address the continual change of the island chain.

  7. Stacking fault induced tunnel barrier in platelet graphite nanofiber

    Science.gov (United States)

    Lan, Yann-Wen; Chang, Wen-Hao; Li, Yuan-Yao; Chang, Yuan-Chih; Chang, Chia-Seng; Chen, Chii-Dong

    2014-09-01

    A correlation study using image inspection and electrical characterization of platelet graphite nanofiber devices is conducted. Close transmission electron microscopy and diffraction pattern inspection reveal layers with inflection angles appearing in otherwise perfectly stacked graphene platelets, separating nanofibers into two domains. Electrical measurement gives a stability diagram consisting of alternating small-large Coulomb blockade diamonds, suggesting that there are two charging islands coupled together through a tunnel junction. Based on these two findings, we propose that a stacking fault can behave as a tunnel barrier for conducting electrons and is responsible for the observed double-island single electron transistor characteristics.

  8. Stacking fault induced tunnel barrier in platelet graphite nanofiber

    International Nuclear Information System (INIS)

    A correlation study using image inspection and electrical characterization of platelet graphite nanofiber devices is conducted. Close transmission electron microscopy and diffraction pattern inspection reveal layers with inflection angles appearing in otherwise perfectly stacked graphene platelets, separating nanofibers into two domains. Electrical measurement gives a stability diagram consisting of alternating small-large Coulomb blockade diamonds, suggesting that there are two charging islands coupled together through a tunnel junction. Based on these two findings, we propose that a stacking fault can behave as a tunnel barrier for conducting electrons and is responsible for the observed double-island single electron transistor characteristics.

  9. Stacking fault induced tunnel barrier in platelet graphite nanofiber

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Yann-Wen, E-mail: chiidong@phys.sinica.edu.tw, E-mail: ywlan@phys.sinica.edu.tw; Chang, Yuan-Chih; Chang, Chia-Seng; Chen, Chii-Dong, E-mail: chiidong@phys.sinica.edu.tw, E-mail: ywlan@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Chang, Wen-Hao [Institute of Physics, Academia Sinica, Taipei 115, Taiwan (China); Graduate Institute of Opto-Mechatronics, National Chung Cheng University, Chia-Yi 62102, Taiwan (China); Li, Yuan-Yao [Graduate Institute of Opto-Mechatronics, National Chung Cheng University, Chia-Yi 62102, Taiwan (China)

    2014-09-08

    A correlation study using image inspection and electrical characterization of platelet graphite nanofiber devices is conducted. Close transmission electron microscopy and diffraction pattern inspection reveal layers with inflection angles appearing in otherwise perfectly stacked graphene platelets, separating nanofibers into two domains. Electrical measurement gives a stability diagram consisting of alternating small-large Coulomb blockade diamonds, suggesting that there are two charging islands coupled together through a tunnel junction. Based on these two findings, we propose that a stacking fault can behave as a tunnel barrier for conducting electrons and is responsible for the observed double-island single electron transistor characteristics.

  10. Liquid metal hydrogen barriers

    International Nuclear Information System (INIS)

    Hydrogen barriers are disclosed which comprise liquid metals in which the solubility of hydrogen is low and which have good thermal conductivities at operating temperatures of interest. Such barriers are useful in nuclear fuel elements containing a metal hydride moderator which has a substantial hydrogen dissociation pressure at reactor operating temperatures. 2 claims, 3 figures

  11. Ordered Arrays of SiGe Islands from Low-Energy PECVD

    Directory of Open Access Journals (Sweden)

    Chrastina D

    2010-01-01

    Full Text Available Abstract SiGe islands have been proposed for applications in the fields of microelectronics, optoelectronics and thermoelectrics. Although most of the works in literature are based on MBE, one of the possible advantages of low-energy plasma-enhanced chemical vapor deposition (LEPECVD is a wider range of deposition rates, which in turn results in the possibility of growing islands with a high Ge concentration. We will show that LEPECVD can be effectively used for the controlled growth of ordered arrays of SiGe islands. In order to control the nucleation of the islands, patterned Si (001 substrates were obtained by e-beam lithography (EBL and dry etching. We realized periodic circular pits with diameters ranging from 80 to 300 nm and depths from 65 to 75 nm. Subsequently, thin films (0.8–3.2 nm of pure Ge were deposited by LEPECVD, resulting in regular and uniform arrays of Ge-rich islands. LEPECVD allowed the use of a wide range of growth rates (0.01–0.1 nm s−1 and substrates temperatures (600–750°C, so that the Ge content of the islands could be varied. Island morphology was characterized by AFM, while μ-Raman was used to analyze the Ge content inside the islands and the composition differences between islands on patterned and unpatterned areas of the substrate.

  12. Genetic differentiation in Elaeocarpus photiniifolia (Elaeocarpaceae) associated with dry and wet habitats in the Bonin (Ogasawara) Islands

    OpenAIRE

    Sugai, Kyoko

    2013-01-01

    Ecological speciation on an oceanic island is a well-known evolutionary phenomenon. In ecological speciation, diversification via the evolution of barriers to gene flow between populations occurs as a result of divergent natural selection under different environmental conditions. The Bonin (Ogasawara) Islands, a typical oceanic island group in the northwestern Pacific Ocean, are located approximately 1,000 km south of mainland Japan. In this study, I investigated Elaeocarpus photiniifolia, an...

  13. Using hydrogeochemical methods to evaluate complex quaternary subsurface stratigraphy Block Island, Rhode Island, USA

    Science.gov (United States)

    Veeger, A.I.; Stone, B.D.

    1996-01-01

    One of the major problems in Hydrogeologic investigations of glaciated regions is the determination of complex stratigraphic relationships in the subsurface where insufficient information is available from drilling and geophysical records. In this paper, chemical characteristics of groundwater were used to identify stratigraphic changes in glacial deposits that were previously inferred on Block Island, Rhode Island, USA, an emergent remnant of the late Wisconsinan terminal moraine, located approximately 16 km south of the Rhode Island mainland. Two chemically distinct water types are recognized on the island: 1) high-iron, characterized by dissolved silica levels in excess of 20 mg/L, bicarbonate greater than 30 mg/L and dissolved iron ranging from 1-20 mg/L; and 2) low-iron, characterized by dissolved silica levels below 16 mg/L, bicarbonate less than 30 mg/L, and less than 0.3 mg/L dissolved iron. The spatial distribution of iron-bearing minerals and organic matter and the resulting redox conditions are believed to control the occurrence of highiron groundwater. The high-iron waters occur almost exclusively in the eastern half of the island and appear to coincide with the presence of allochthonous blocks of Cretaceous-age coastal-plain sediments that were incorporated into Pleistocene-age deposits derived from the Narragansett Bay-Buzzard's Bay lobe of the Late Wisconsinan Laurentide ice sheet. The low-iron waters occur in the western half of the island, where the occurrence of these Cretaceous-age blocks is rare and the sediments are attributed to a sublobe of the Hudson-Champlain lobe of the Late Wisconsinan ice sheet.

  14. Catalytic thermal barrier coatings

    Science.gov (United States)

    Kulkarni, Anand A.; Campbell, Christian X.; Subramanian, Ramesh

    2009-06-02

    A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

  15. Radar Image of Galapagos Island

    Science.gov (United States)

    1994-01-01

    This is an image showing part of Isla Isabella in the western Galapagos Islands. It was taken by the L-band radar in HH polarization from the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar on the 40th orbit of the space shuttle Endeavour. The image is centered at about 0.5 degree south latitude and 91 degrees west longitude and covers an area of 75 by 60 kilometers (47 by 37 miles). The radar incidence angle at the center of the image is about 20 degrees.The western Galapagos Islands, which lie about 1,200 kilometers (750 miles) west of Ecuador in the eastern Pacific, have six active volcanoes similar to the volcanoes found in Hawaii. Since the time of Charles Darwin's visit to the area in 1835, there have been over 60 recorded eruptions of these volcanoes. This SIR-C/X-SAR image of Alcedo and Sierra Negra volcanoes shows the rougher lava flows as bright features, while ash deposits and smooth pahoehoe lava flows appear dark. A small portion of Isla Fernandina is visible in the extreme upper left corner of the image.The Galapagos Islands are one of the SIR-C/X-SAR supersites and data of this area will be taken several times during the flight to allow scientists to conduct topographic change studies and to search for different lava flow types, ash deposits and fault lines.Spaceborne Imaging Radar-C and X-Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: L-band (24 cm), C-band (6 cm) and X-band (3 cm). The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by

  16. Pratt & Whitney thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Bornstein, N. [United Technologies Research Center, East Hartford, CT (United States); Marcin, J. [Pratt & Whitney Aircraft Co., East Hartford, CT (United States)

    1995-10-01

    The objective of the Advanced Turbine Systems (ATS) Program is to develop ultra-high efficient, environmentally superior, and cost competitive gas turbine systems. The operating profiles of these industrial gas turbines are long, less cyclic with fewer transients-compared with those for aircraft gas turbine engines. Therefore, creep rather than thermal fatigue, becomes primary life-limiting for hot section components. Thermal barrier coatings (TBCs) will be used to achieve the objectives of the program. TBCs allow surface temperatures to increase without compromising the structural properties of the alloy. TBCs typically consist of a ceramic insulating layer, deposited onto the substrate with an intervening metallic layer, which imparts oxidation protection to the substrate and provides a surface to which the ceramic layer can adhere.

  17. Census Snapshot: Rhode Island

    OpenAIRE

    Romero, Adam P; Baumle, Amanda; Badgett, M. V. Lee; Gates, Gary J.

    2007-01-01

    Using data from the U.S. Census Bureau, this report provides demographic and economic information about same-sex couples and same-sex couples raising children in Rhode Island. We compare same-sex “unmarried partners,” which the Census Bureau defines as an unmarried couple who “shares living quarters and has a close personal relationship,” to different-sex married couples in Rhode Island. In many ways, the over 2,400 same-sex couples living in Rhode Island are similar to married coupl...

  18. Controls on plio-quaternary foreland sedimentation in the region of the Maltese Islands

    OpenAIRE

    Gatt, Peter A.

    2007-01-01

    Plio-Quaternary sediments on the southern foreland of the orogen produced by African-Eurasian plate convergence vary in thick-ness from > 1km in foreland basin and rift graben depocentres to metre-thick deposits over platform environment where depositional hiatuses merge along widespread subaerial surfaces around the Maltese Islands. The syntectonic sedimentation is the result of three episodes: (i) The development of the Pantelleria Rift south of the Maltese Islands by passive rifting, which...

  19. Westinghouse thermal barrier coatings development

    Energy Technology Data Exchange (ETDEWEB)

    Goedjen, J.G.; Wagner, G. [Westinghouse Electric Corp., Orlando, FL (United States)

    1995-10-01

    Westinghouse, in conjunction with the Department of Energy and Oak Ridge National Laboratory, has embarked upon a program for the development of advanced thermal barrier coatings for industrial gas turbines. Development of thermal barrier coatings (TBC`s) for industrial gas turbines has relied heavily on the transfer of technology from the aerospace industry. Significant differences in the time/temperature/stress duty cycles exist between these two coating applications. Coating systems which perform well in aerospace applications may not been optimized to meet power generation performance requirements. This program will focus on development of TBC`s to meet the specific needs of power generation applications. The program is directed at developing a state-of-the-art coating system with a minimum coating life of 25,000 hours at service temperatures required to meet increasing operating efficiency goals. Westinghouse has assembled a team of university and industry leaders to accomplish this goal. Westinghouse will coordinate the efforts of all program participants. Chromalloy Turbine Technologies, Inc. and Sermatech International, Inc. will be responsible for bond coat and TBC deposition technology. Praxair Specialty Powders, Inc. will be responsible for the fabrication of all bond coat and ceramic powders for the program. Southwest Research Institute will head the life prediction modelling effort; they will also be involved in coordinating nondestructive evaluation (NDE) efforts. Process modelling will be provided by the University of Arizona.

  20. Magnetic islands and spontaneous generation of zonal flows

    International Nuclear Information System (INIS)

    A study of saturated magnetic island equilibria on the basis of the resistive magneto-hydro-dynamic model is presented. A bifurcation in the sequence of equilibria is found as the ratio of the width of the current layer in the initial (non-reconnected) configuration over the island periodicity length reaches a critical threshold. Below this threshold, spontaneous generation of zonal flows occurs. This result is suggestive of a possible evolution of current sheets in magnetically confined plasmas and may be relevant to the understanding of the suppression of drift-wave turbulence and the formation of internal transport barriers in tokamak experiments. (letter to the editor)

  1. Magnetic islands and spontaneous generation of zonal flows

    Energy Technology Data Exchange (ETDEWEB)

    Grasso, D [Burning Plasma Research Group, Department of Energetics, Politecnico di Torino (Italy); Margheriti, L [Department of Mathematics, Universita di Messina (Italy); Porcelli, F [Burning Plasma Research Group, Department of Energetics, Politecnico di Torino (Italy); Tebaldi, C [Burning Plasma Research Group, Department of Energetics, Politecnico di Torino (Italy)

    2006-09-15

    A study of saturated magnetic island equilibria on the basis of the resistive magneto-hydro-dynamic model is presented. A bifurcation in the sequence of equilibria is found as the ratio of the width of the current layer in the initial (non-reconnected) configuration over the island periodicity length reaches a critical threshold. Below this threshold, spontaneous generation of zonal flows occurs. This result is suggestive of a possible evolution of current sheets in magnetically confined plasmas and may be relevant to the understanding of the suppression of drift-wave turbulence and the formation of internal transport barriers in tokamak experiments. (letter to the editor)

  2. Effects of Building a Sand Barrier Berm to Mitigate the Effects of the Deepwater Horizon Oil Spill on Louisiana Marshes

    Science.gov (United States)

    Lavoie, Dawn; Flocks, James G.; Kindinger, Jack L.; Sallenger, A.H., Jr.; Twichell, David C.

    2010-01-01

    The State of Louisiana requested emergency authorization on May 11, 2010, to perform spill mitigation work on the Chandeleur Islands and on all the barrier islands from Grand Terre Island eastward to Sandy Point to enhance the capability of the islands to reduce the movement of oil from the Deepwater Horizon oil spill to the marshes. The proposed action-building a barrier berm (essentially an artificial island fronting the existing barriers and inlets) seaward of the existing barrier islands and inlets-'restores' the protective function of the islands but does not alter the islands themselves. Building a barrier berm to protect the mainland wetlands from oil is a new strategy and depends on the timeliness of construction to be successful. Prioritizing areas to be bermed, focusing on those areas that are most vulnerable and where construction can be completed most rapidly, may increase chances for success. For example, it may be easier and more efficient to berm the narrow inlets of the coastal section to the west of the Mississippi River Delta rather than the large expanses of open water to the east of the delta in the southern parts of the Breton National Wildlife Refuge (NWR). This document provides information about the potential available sand resources and effects of berm construction on the existing barrier islands. The proposed project originally involved removing sediment from a linear source approximately 1 mile (1.6 km) gulfward of the barrier islands and placing it just seaward of the islands in shallow water (~2-m depth where possible) to form a continuous berm rising approximately 6 feet (~2 m) above sea level (North American Vertical Datum of 1988-NAVD88) with an ~110-yd (~100-m) width at water level and a slope of 25:1 to the seafloor. Discussions within the U.S. Geological Survey (USGS) and with others led to the determination that point-source locations, such as Hewes Point, the St. Bernard Shoals, and Ship Shoal, were more suitable 'borrow

  3. Wading bird guano contributes to Hg accumulation in tree island soils in the Florida Everglades

    International Nuclear Information System (INIS)

    Tree islands are habitat for wading birds and a characteristic landscape feature in the Everglades. A total of 93 surface soil and 3 soil core samples were collected from 7 degraded/ghost and 34 live tree islands. The mean Hg concentration in surface soils of ghost tree islands was low and similar to marsh soil. For live tree islands, Hg concentrations in the surface head region were considerably greater than those in mid and tail region, and marsh soils. Hg concentrations in bird guano (286 μg kg−1) were significantly higher than those in mammal droppings (105 μg kg−1) and plant leaves (53 μg kg−1). In addition, Hg concentrations and δ15N values displayed positive correlation in soils influenced by guano. During 1998–2010, estimated annual Hg deposition by guano was 148 μg m−2 yr−1 and ∼8 times the atmospheric deposition. Highlights: • Hg concentrations in the head region of tree islands were the highest. • Hg concentrations in bird guano (286 μg kg−1) were significantly higher than those in mammal droppings and plant leaves. • Hg concentrations and δ15N values showed positive correlation in soils influenced by guano. • Estimated annual Hg deposition by guano was 148 μg m−2 yr−1, ∼8 times the atmospheric deposition. -- The annual Hg deposition by bird guano to tree island soils in the Everglades was ∼8 times the atmospheric deposition

  4. Nunivak Island muskox studies

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the Nunivak Island muskox, summarizing the carrying capacity and age and sex ratios. Recommendations are attached for muskox management.

  5. Solomon Islands; Selected Issues

    OpenAIRE

    International Monetary Fund

    2011-01-01

    This paper analyzes Solomon Islands’ ongoing reforms concerning of the mineral taxation regime and the fiscal impact of mineral resources. The analysis shows that mineral revenue could be substantial, provided that mineral prices remain strong in the medium term. Enforcing the tax agreement with, a Gold Ridge company, and implementing the new resource taxation regime are critical to ensure that the forthcoming mineral wealth spills over to the rest of the economy. Solomon Islands should ado...

  6. Complementary barrier infrared detector (CBIRD)

    Science.gov (United States)

    Ting, David Z. (Inventor); Bandara, Sumith V. (Inventor); Hill, Cory J. (Inventor); Gunapala, Sarath D. (Inventor)

    2013-01-01

    An infrared detector having a hole barrier region adjacent to one side of an absorber region, an electron barrier region adjacent to the other side of the absorber region, and a semiconductor adjacent to the electron barrier.

  7. Deposited radionuclides

    International Nuclear Information System (INIS)

    The results presented are from the nationwide programme to survey the fall-out levels of radionuclides in Finland. This programme includes results from the vicinities of the nuclear power plants at Loviisa and Olkiluoto. Analysis of deposition samples for their 3H, 89Sr and 90Sr, as well as 137Cs and other gamma radionuclide contents was continued. The results are given as a follow-up to the previous results. The cumulative deposition of long-lived radionuclides retained in soil was measured near the Finnish nuclear power stations. The 90Sr and 137Cs levels in deposition in 1979 were lower than in the previous two years, and no 89Sr was detected. The trend to slightly increasing 3H concentrations of previous years was reversed in 1979. The mean annual deposition of tritium at different sampling stations varied from 85 nCi/m2 (3.1 kBq/m2) to 180 nCi/m2 (6.7 kBq/m2). The total annual deposits of various fission product radionuclides have decreased continuously since the maximum in 1977. No short-lived radionuclides originating from either nuclear explosions or nuclear power plants were observed in 1979. (author)

  8. Deposited radionuclides

    International Nuclear Information System (INIS)

    The measurements presented here were carried out for determination of the fallout levels of radionuclides throughout the country, including the areas surrounding the nuclear power plants at Loviisa and Olkiluoto. The 90Sr, 137Cs and 3H contents of deposition were determined and the results are given as a follow-up to the previous results. 89Sr and other gammaradionuclides in addition to 137Cs were measured from wet and dry deposition. Also 89-90Sr, 239-240Pu, 137Cs and other gammaradionuclides deposited in soil were measured. The radiochemical separation technique was used to determine 89Sr, 90Sr, 137Cs and 239-240Pu. Tritium contents were determined by liquid scintillation counting after electrolytic enrichment. Gammaradionuclides were measured by Ge(Li) spectrometry. In 1977 the contents of the long-lived radionuclides 90Sr and 137Cs in deposition increased to almost the same level as in the early '70s. This is due to the high-yield atmospheric nuclear weapon tests carried out by China. A slight increase in 3H deposition can also be noticed in 1977. The results of soil sample measurements indicate that practically all the activity is found in the top 20 cm layer. (author)

  9. Deposited radionuclides

    International Nuclear Information System (INIS)

    Measurements were carried out to determine the fall-out levels of radionuclides in Finland including those from the surroundings of the nuclear power plants at Loviisa and Olkiluoto. Deposition samples were analysed for their 3H, 89Sr and 90Sr as well as 137Cs and other gamma radionuclide contents. 90Sr, 239,240Pu, as well as 137Cs and other gamma radionuclides deposited in soil were also measured. The 90Sr and 137Cs levels in deposition in 1978 remained at almost the same level as in 1977. The slightly increasing trend in 3H concentrations continued in 1978. The mean annual deposition of tritium at different sampling stations varied from 120 nCi/m2 (4.4 kBq/m2) to 200 nCi/m2 (7.4 kBq/m2). The total annual deposits of various fission product radionuclides during 1978 were smaller than during 1977. No increase in radioactivity originating from nuclear power plants could be observed. (author)

  10. Converse Barrier Certificate Theorem

    DEFF Research Database (Denmark)

    Wisniewski, Rafael; Sloth, Christoffer

    2013-01-01

    This paper presents a converse barrier certificate theorem for a generic dynamical system.We show that a barrier certificate exists for any safe dynamical system defined on a compact manifold. Other authors have developed a related result, by assuming that the dynamical system has no singular...... points in the considered subset of the state space. In this paper, we redefine the standard notion of safety to comply with generic dynamical systems with multiple singularities. Afterwards, we prove the converse barrier certificate theorem and illustrate the differences between ours and previous work by...

  11. Recycler barrier RF buckets

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C.M.; /Fermilab

    2011-03-01

    The Recycler Ring at Fermilab uses a barrier rf systems for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf system, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

  12. Recycler barrier RF buckets

    CERN Document Server

    Bhat, C M

    2012-01-01

    The Recycler Ring at Fermilab uses a barrier rf system for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf systems, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

  13. Islands and Islandness in Rock Music Lyrics

    Directory of Open Access Journals (Sweden)

    Daniele Mezzana

    2012-05-01

    Full Text Available This paper presents a first exploration, qualitative in character, based on a review of 412 songs produced in the period 1960-2009, about islands in rock music as both social products and social tools potentially contributing to shaping ideas, emotions, will, and desires. An initial taxonomy of 24 themes clustered under five meta-themes of space, lifestyle, emotions, symbolism, and social-political relations is provided, together with some proposals for further research.

  14. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    <正>20111705 An Junbo(Team 603,Bureau of Nonferrous Metals Geological Exploration of Jilin Province,Hunchun 133300,China);Xu Renjie Geological Features and Ore Genesis of Baishilazi Scheelite Deposit in Yanbian Area(Jilin Geology,ISSN1001-2427,CN22-1099/P,29(3),2010,p.39-43,2 illus.,2 tables,7 refs.)Key words:tungsten ores,Jilin ProvinceThe Baishilazi scheelite deposit is located in contacting zone between the marble of the Late Palaeozoic Qinglongcun Group and the Hercynian biotite granite.The vein and lenticular major ore body is obviously controlled by NE-extending faults and con

  15. Protective barrier development: Overview

    International Nuclear Information System (INIS)

    Protective barrier and warning marker systems are being developed to isolate wastes disposed of near the earth's surface at the Hanford Site. The barrier is designed to function in an arid to semiarid climate, to limit infiltration and percolation of water through the waste zone to near-zero, to be maintenance free, and to last up to 10,000 yr. Natural materials (e.g., fine soil, sand, gravel, riprap, clay, asphalt) have been selected to optimize barrier performance and longevity and to create an integrated structure with redundant features. These materials isolate wastes by limiting water drainage; reducing the likelihood of plant, animal, and human intrusion; controlling emission of noxious gases; and minimizing erosion. Westinghouse Hanford Company and Pacific Northwest Laboratory efforts to assess the performance of various barrier and marker designs will be discussed

  16. Information barriers and authentication

    International Nuclear Information System (INIS)

    Acceptance of nuclear materials into a monitoring regime is complicated if the materials are in classified shapes or have classified composition. An attribute measurement system with an information barrier can be emplo,yed to generate an unclassified display from classified measurements. This information barrier must meet two criteria: (1) classified information cannot be released to the monitoring party, and (2) the monitoring party must be convinced that the unclassified output accurately represents the classified input. Criterion 1 is critical to the host country to protect the classified information. Criterion 2 is critical to the monitoring party and is often termed the 'authentication problem.' Thus, the necessity for authentication of a measurement system with an information barrier stems directly from the description of a useful information barrier. Authentication issues must be continually addressed during the entire development lifecycle of the measurement system as opposed to being applied only after the system is built.

  17. Clear Cell Basal Cell Carcinoma with Sialomucin Deposition

    OpenAIRE

    Kim, Do Young; Cho, Sung Bin; Chung, Kee Yang; Kim, You Chan

    2006-01-01

    Clear cell basal cell carcinoma (BCC) is a variant of BCC with a characteristic clear cell component that may occupy all or part of the tumor islands. Periodic acid-Schiff (PAS) staining for glycogen is variably positive, and mild deposition of sulfated mucin has been noted. However, to our knowledge, clear cell BCC with sialomucin deposition has not been reported. Here we report a case of clear cell BCC showing sialomucin deposition. The clear tumor cells stained with PAS and showed incomple...

  18. Increasing the active surface of titanium islands on graphene by nitrogen sputtering

    CERN Document Server

    Mashoff, T; Miseikis, V; Coletti, C; Piazza, V; Beltram, F; Heun, S

    2014-01-01

    Titanium-island formation on graphene as a function of defect density is investigated. When depositing titanium on pristine graphene, titanium atoms cluster and form islands with an average diameter of about 10nm and an average height of a few atomic layers. We show that if defects are introduced in the graphene by ion bombardment, the mobility of the deposited titanium atoms is reduced and the average diameter of the islands decreases to 5nm with monoatomic height. This results in an optimized coverage for hydrogen storage applications since the actual titanium surface available per unit graphene area is significantly increased.

  19. Groundwater flow in a relatively old oceanic volcanic island: The Betancuria area, Fuerteventura Island, Canary Islands, Spain

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, Christian, E-mail: cherrera@ucn.cl [Universidad Católica del Norte, Av. Angamos 0610, Antofagasta (Chile); Custodio, Emilio [Department of Geo-Engineering, Technical University of Catalonia (UPC), Barcelona (Spain)

    2014-10-15

    The island of Fuerteventura is the oldest of the Canary Islands' volcanic archipelago. It is constituted by volcanic submarine and subaerial activity and intrusive Miocene events, with some residual later volcanism and Quaternary volcanic deposits that have favored groundwater recharge. The climate is arid, with an average rainfall that barely attains 60 mm/year in the coast and up to 200 mm/year in the highlands. The aquifer recharge is small but significant; it is brackish due to large airborne atmospheric salinity, between 7 and 15 g m{sup −2} year{sup −1} of chloride deposition, and high evapo-concentration in the soil. The average recharge is estimated to be less than about 5 mm/year at low altitude and up to 10 mm/year in the highlands, and up to 20 mm/year associated to recent lava fields. Hydrochemical and water isotopic studies, supported by water table data and well and borehole descriptions, contribute a preliminary conceptual model of groundwater flow and water origin in the Betancuria area, the central area of the island. In general, water from springs and shallow wells tends to be naturally brackish and of recent origin. Deep saline groundwater is found and is explained as remnants of very old marine water trapped in isolated features in the very low permeability intrusive rocks. Preliminary radiocarbon dating indicates that this deep groundwater has an apparent age of less than 5000 years BP but it is the result of mixing recent water recharge with very old deep groundwater. Most of the groundwater flow occurs through the old raised volcanic shield of submarine and subaerial formations and later Miocene subaerial basalts. Groundwater transit time through the unsaturated zone is of a few decades, which allows the consideration of long-term quasi-steady state recharge. Transit times are up to a few centuries through the saturated old volcanics and up to several millennia in the intrusive formations, where isolated pockets of very old water may

  20. Groundwater flow in a relatively old oceanic volcanic island: The Betancuria area, Fuerteventura Island, Canary Islands, Spain

    International Nuclear Information System (INIS)

    The island of Fuerteventura is the oldest of the Canary Islands' volcanic archipelago. It is constituted by volcanic submarine and subaerial activity and intrusive Miocene events, with some residual later volcanism and Quaternary volcanic deposits that have favored groundwater recharge. The climate is arid, with an average rainfall that barely attains 60 mm/year in the coast and up to 200 mm/year in the highlands. The aquifer recharge is small but significant; it is brackish due to large airborne atmospheric salinity, between 7 and 15 g m−2 year−1 of chloride deposition, and high evapo-concentration in the soil. The average recharge is estimated to be less than about 5 mm/year at low altitude and up to 10 mm/year in the highlands, and up to 20 mm/year associated to recent lava fields. Hydrochemical and water isotopic studies, supported by water table data and well and borehole descriptions, contribute a preliminary conceptual model of groundwater flow and water origin in the Betancuria area, the central area of the island. In general, water from springs and shallow wells tends to be naturally brackish and of recent origin. Deep saline groundwater is found and is explained as remnants of very old marine water trapped in isolated features in the very low permeability intrusive rocks. Preliminary radiocarbon dating indicates that this deep groundwater has an apparent age of less than 5000 years BP but it is the result of mixing recent water recharge with very old deep groundwater. Most of the groundwater flow occurs through the old raised volcanic shield of submarine and subaerial formations and later Miocene subaerial basalts. Groundwater transit time through the unsaturated zone is of a few decades, which allows the consideration of long-term quasi-steady state recharge. Transit times are up to a few centuries through the saturated old volcanics and up to several millennia in the intrusive formations, where isolated pockets of very old water may exist

  1. Volcanic Geology of Negit Island, Mono Lake, CA

    Science.gov (United States)

    Bursik, M.; Kobs, S.; Jayko, A.

    2008-12-01

    Negit Island, located in Mono Lake, eastern California, is a dacitic cumulodome with seven distinct lava flows emanating from at least four separate vent areas. Vent areas are dominated by en echelon northeast-trending fissures, indicating strong tectonic control. Neptunian(?) pyroclastic deposits on the north end of the island indicate an explosive subaqueous eruption early in island history. Northwestern shorelands, as well as a former landbridge to the island, retain a localized cap of rotated Pleistocene lake bottom sediment blocks, suggesting that proto-Negit was similar to modern Paoha Island, a nearby young structural dome draped with rotated lake bed blocks and explosive ejecta. In analogy with Paoha, the pyroclastic ejecta and blocks may thus indicate sublacustrine block landsliding with attendant eruption as an initial magmatic-structural dome grew, on which later lava domes and flows were superposed. What may be the oldest lava flow, in the center-west, is overlain by a deep orange-red soil, and three Mono Craters tephras. The well-developed soil indicates an extended period of chemical weathering before overlying tephra deposition. The southwestern end of the island is dominated by young lava flows and a prominent dome, which are not overlain by the most recent North Mono Craters tephra of 1350 A.D., consistent with earlier work indicating that parts of the island are younger than any eruption of the Mono Craters. The history of early structural doming with little or minimal eruptive activity at both Negit and Paoha Islands may have important implications for the current episode of noneruptive unrest and doming at nearby Long Valley caldera.

  2. Hemicellulose as barrier material

    OpenAIRE

    Jonas, Hartman

    2006-01-01

    Polysaccharides constitute an important source of raw materials for the packaging industry today. Polysaccharides have good natural barrier properties which are necessary for packaging films. Cellulose is the forerunner among renewable polymers for such applications. Hemicelluloses represent a new interesting breed of barrier materials. We have chosen to work with the hemicellulose O-acetyl-galactoglucomannan (AcGGM). The high water solubility of this particular hemicellulose extracted from p...

  3. Barriers to SCM implementing

    OpenAIRE

    M.E. Rosli; B. Md Dero; A.R. Ismail; M.N. Ab Rahman

    2008-01-01

    Purpose: This paper explores the barriers faced by Malaysian manufacturing companies in successfullyimplementing the Supply Chain Management (SCM). The study has highlighted some pertinent factorsperforming the barriers that are most frequently reported by the studied companies. Sixteen companies, fromservice and manufacturing companies were studied over a period of two years to assess their SCM practicesthrough survey and interview processes.Design/methodology/approach: This part discusses t...

  4. Multilayer coatings for flexible high-barrier materials

    Science.gov (United States)

    Vaško, Karol; Noller, Klaus; Mikula, Milan; Amberg-Schwab, Sabine; Weber, Ulrike

    2009-06-01

    A multilayer, flexible, and transparent high-barrier system based on flexible plastic foils, polyethyleneterephthalate (PET) and ethylene-tetrafluoroethylene-copolymer (ETFE), combined with vacuum-deposited, inorganic SiOx layers and hybrid ORMOCER® varnish layers were prepared in different orders on a semiproduction level. Barrier properties of prepared systems, as water vapour transmission (WVTR) and oxygen transmission (OTR), were measured and studied in connection with surface energy, surface topography, and water vapour adsorption properties. Correlations among layers sequence, barrier properties, and other parameters are presented, including some basic principles of permeation of substances through multilayer barrier systems. A combination of several inorganic and hybrid varnish layers is necessary to achieve the technological demands from a barrier standpoint. It is easier to suppress the oxygen transport than the water transport, due to the additional active penetration of water through hydrogen bonds and silanol creations at oxide interfaces, capillary condensation, and swelling with high internal pressure, leading to new defects.

  5. Sustainable Energy Portfolios for Small Island States

    Directory of Open Access Journals (Sweden)

    Sándor Szabó

    2015-09-01

    Full Text Available The study presents a cost effective electricity generation portfolio for six island states for a 20-year period (2015–2035. The underlying concept investigates whether adding sizeable power capacities of renewable energy sources (RES options could decrease the overall costs and contribute to a more sustainable, indigenous electricity generation at the same time. Often, island states rely on fossil fuels which, apart from dependence on foreign resources, also includes an additional, significant transport cost. This is an extra motive to study the extent in which island states represent primary locations for RES technologies. For the aims of the present study an optimization model has been developed and following numerous runs the obtained results show that installing PV and battery capacities can delay-reduce the huge investments in fossil options in early periods. Thus, investment on RES can have a positive, long-term effect on the overall energy mix. This prompt development can happen without adding new subsidies but there is a need to address the existing socio-economic barriers with intelligent design of financing and economic instruments and capacity building as discussed in the conclusions.

  6. METALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    20150904An Fang(State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China);Wang Juli Skarn Mineral Assemblage in Representative Ore Districts of Sayak Copper Orefield,Kazakhstan,and Its Genetic Implications(Mineral Deposits,ISSN0258-7106,CN11-1965/P,33(3),2014,p.521-540,

  7. NONMETALS DEPOSITS

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131601 Gao Junbo(College of Resources and Environmental Engineering,Guizhou University,Guiyang 550003,China);Yang Ruidong Hydrothermal Venting-Flowing Sedimentation Characteristics of Devonian Barite Deposits from Leji,Zhenning County,Guizhou Province(Acta Sedimentologica Sinica,ISSN1000-0550,CN62-1038/P,30(3),

  8. Growth mechanism and structure characterizations of GaSb islands grown on Si (1 0 0) substrates by LP-MOCVD

    Science.gov (United States)

    Lv, You; Liu, Ren-Jun; Wang, Lian-Kai; Li, Guo-Xing; Zhang, Yuan-Tao; Dong, Xin; Zhang, Bao-Lin

    2015-07-01

    In this paper, the growth mechanism and the morphologies of GaSb islands grown on Si (1 0 0) by low-pressure metal-organic chemical vapor deposition have been studied. It was observed the GaSb growth mode transited from SK to VW mode with time, while the islands migrated in VW mode on the surface. As growth time prolonging, the islands were coarsening consistent with the considerations of Ostwald ripening substituting for migration. And it was the similar coalescence process in the various interruption time. The formation of giant islands reduced the surface energy with the island-induced strain fields which drive the islands distribution evenly.

  9. Sustained morphologic changes to the shoreface related to Hurricane Sandy: Fire Island, NY

    Science.gov (United States)

    Hapke, C. J.; Nelson, T. R.

    2014-12-01

    A variety of topographic and photographic data have revealed widespread impacts to the subaerial portion of the beach system during Hurricane Sandy in 2012 - from beach erosion to barrier island breaching. However, less is known about impacts to the offshore environment. In order to examine a more comprehensive response of the active beach system to Hurricane Sandy, we quantify morphologic changes to the shoreface using bathymetric data along the length of Fire Island, NY. Airborne bathymetric lidar data, collected two days before Sandy made landfall, are used as a pre-storm baseline. Morphologic changes are measured using field surveyed GPS profiles collected along a limited portion of western Fire Island two months following Sandy and along the length of the island one year after Sandy. The offshore extent of the data is variable and analyses are constrained by the resolving ability of the lidar sensor, which typically achieved penetration to depths of 6-8m. The surfzone morphology was extensively impacted by Hurricane Sandy and continued to evolve during subsequent winter storms. As is typical during large storm events, the outer bar moved offshore during Sandy. A year after the storm, however, the bar remains further offshore than it was prior to Sandy, resulting in a widened surfzone. Both the subaerial and submarine portions of the beach system lost considerable volumes of sand. The majority of the loss below mean high water (MHW) is in the surfzone, concentrated in the trough immediately landward of the outer bar and generally in the pre-storm location of the outer bar. The trough not only deepened in response to Sandy, but in many locations continued to deepen over the course of the following year, with an average change of more than a meter. The average volume of the shoreface seaward of the bar increased, which is attributed to the seaward translation of the outer bar and additional offshore transport and deposition of material from the inner surfzone

  10. Large eruption-triggered ocean-island landslide at Tenerife

    DEFF Research Database (Denmark)

    Harris, P; Branney, M; Storey, Michael

    2011-01-01

    An extensive debris-avalanche deposit has been discovered on Cañadas volcano, Tenerife (Canary Islands). The onshore component of the 733 ± 3 ka Abona landslide deposit exposes classic block facies and mixed facies across 90 km2. Three lines of evidence together show that the avalanche was...... breadcrust surfaces; (3) these blocks yield the same 40Ar/39Ar date as the associated ignimbrite and fall deposit. Landslide hummocks dammed surface water, forming ephemeral lakes perched on the volcano flank. Phonolite dome growth destabilized the southeast sector of a mid-Pleistocene Cañadas caldera wall...

  11. Seal Island and Franklin Island National Wildlife Refuges Trip Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of visits to both Seal Island National Wildlife Refuge and Franklin Island National Wildlife Refuge on August 14, 15, 16, 1982.

  12. Islands of Astronomy

    Directory of Open Access Journals (Sweden)

    Godfrey Baldacchino

    2009-05-01

    Full Text Available A global review of islands and their connections with astronomy throughout history up to the contemporary times suggests eight compelling, distinct yet interlocking reasons why islands have been and remain so important to astronomy and astronomers. Islands constitute favourable locations for various types of astronomy-related activities: from tracking satellites and monitoring significant celestial events, to providing exceptional locations to jurisdictions with mandated dark and unpolluted skies. They appeal for their favourable longitude and (especially southern latitude, as well as for their disposition towards the conditions that the scientific community may expect in an ideal world: relatively clear viewing conditions from a secure, self-contained platform that is, however, endowed with connectivity. This article is written as a contribution to the International Year of Astronomy (2009.

  13. The Flooding of Long Island Sound

    Science.gov (United States)

    Thomas, E.; Varekamp, J. C.; Lewis, R. S.

    2007-12-01

    Between the Last Glacial Maximum (22-19 ka) and the Holocene (10 ka) regions marginal to the Laurentide Ice Sheets saw complex environmental changes from moraines to lake basins to dry land to estuaries and marginal ocean basins, as a result of the interplay between the topography of moraines formed at the maximum extent and during stages of the retreat of the ice sheet, regional glacial rebound, and global eustatic sea level rise. In New England, the history of deglaciation and relative sea level rise has been studied extensively, and the sequence of events has been documented in detail. The Laurentide Ice Sheet reached its maximum extent (Long Island) at 21.3-20.4 ka according to radiocarbon dating (calibrated ages), 19.0-18.4 ka according to radionuclide dating. Periglacial Lake Connecticut formed behind the moraines in what is now the Long Island Sound Basin. The lake drained through the moraine at its eastern end. Seismic records show that a fluvial system was cut into the exposed lake beds, and a wave-cut unconformity was produced during the marine flooding, which has been inferred to have occurred at about 15.5 ka (Melt Water Pulse 1A) through correlation with dated events on land. Vibracores from eastern Long Island Sound penetrate the unconformity and contain red, varved lake beds overlain by marine grey sands and silts with a dense concentration of oysters in life position above the erosional contact. The marine sediments consist of intertidal to shallow subtidal deposits with oysters, shallow-water foraminifera and litoral diatoms, overlain by somewhat laminated sandy silts, in turn overlain by coarser-grained, sandy to silty sediments with reworked foraminifera and bivalve fragments. The latter may have been deposited in a sand-wave environment as present today at the core locations. We provide direct age control of the transgression with 30 radiocarbon dates on oysters, and compared the ages with those obtained on macrophytes and bulk organic carbon in

  14. Overview on the Development of Nanostructured Thermal Barrier Coatings

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Thermal barrier coatings (TBCs) have successfully been used in gas turbine engines for increasing operation temperature and improving engine efficiency. Over the past thirty years, a variety of TBC materials and TBC deposition techniques have been developed. Recently, nanostructured TBCs emerge with the potential of commercial applications in various industries. In this paper, TBC materials and TBC deposition techniques such as air plasma spray (APS), electron beam physical vapor deposition (EB-PVD), laser assisted chemical vapor deposition (LACVD) are briefly reviewed. Nanostructured 7-8 wt pct yttria stabilized zirconia (7-8YSZ)TBC by air plasma spraying of powder and new TBC with novel structure deposited by solution precursor plasma spray (SPPS) are compared. Plasma spray conditions, coating forming mechanisms, microstructures,phase compositions, thermal conductivities, and thermal cycling lives of the APS nanostructured TBC and the SPPS nanostructured TBC are discussed. Research opportunities and challenges of nanostructured TBCs deposited by air plasma spray are prospected.

  15. Single-Beam Bathymetry Survey Tracklines Collected in 2012 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 12BIM04)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey's St. Petersburg Coastal and Marine Science Center conducted...

  16. Single-Beam Bathymetric Data Collected in 2012 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 12BIM04)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey's St. Petersburg Coastal and Marine Science Center conducted...

  17. Single-Beam Bathymetric Data Collected in 2011 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 11BIM02)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center conducted...

  18. Interferometric Swath Bathymetry Survey Tracklines Collected in 2012 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 12BIM03)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey's St. Petersburg Coastal and Marine Science Center conducted...

  19. Single-Beam Bathymetry Survey Tracklines Collected in 2011 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 11BIM02)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center conducted...

  20. Sediment Sample Locations Collected in September 2012 from the Northern Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 12LGC02)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research (BIER) project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center...

  1. Sediment Sample Locations Collected in March 2012 from the Northern Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 12BIM01)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research (BIER) project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center...

  2. Sediment Sample Locations Collected in July 2013 from the Northern Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 13BIM05)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research (BIER) project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center...

  3. 1-Meter Sample Resolution Interferometric Swath Backscatter Data Collected in 2012 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 12BIM03)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey's St. Petersburg Coastal and Marine Science Center conducted...

  4. 5-Meter Sample Resolution Interferometric Swath Bathymetric Data Collected in 2011 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 11BIM01)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center conducted...

  5. Interferometric Swath Bathymetric Data Collected in 2012 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 12BIM03)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey's St. Petersburg Coastal and Marine Science Center conducted...

  6. Interferometric Swath Bathymetry Survey Tracklines Collected in 2011 from the Chandeleur Islands, Louisiana (U.S. Geological Survey Field Activity Number 11BIM01)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center conducted...

  7. Discursive barriers and cross-scale forest governance in Central Kalimantan, Indonesia

    OpenAIRE

    Caleb T. Gallemore; Rut Dini. Prasti H.; Moira Moeliono

    2014-01-01

    Students of social-ecological systems have emphasized the need for effective cross-scale governance. We theorized that discursive barriers, particularly between technical and traditional practices, can act as a barrier to cross-scale collaboration. We analyzed the effects of discursive divides on collaboration on Reducing Emissions from Deforestation and Forest Degradation (REDD+) policy development in Central Kalimantan, an Indonesian province on the island of Borneo selected in 2010 to p...

  8. 78 FR 48668 - PSEG Long Island LLC, Long Island Electric Utility Servco LLC, Long Island Power Authority, Long...

    Science.gov (United States)

    2013-08-09

    ... Energy Regulatory Commission PSEG Long Island LLC, Long Island Electric Utility Servco LLC, Long Island Power Authority, Long Island Lighting Company; Notice of Petition for Declaratory Order Take notice that...) Rules of Practice and Procedure, 18 CFR 385.207, PSEG Long Island LLC (PSEG LI), Long Island...

  9. Combined multibeam and bathymetry data from Rhode Island Sound and Block Island Sound: a regional perspective

    Science.gov (United States)

    Poppe, Lawrence J.; McMullen, Katherine Y.; Danforth, William W.; Blankenship, Mark R.; Clos, Andrew R.; Glomb, Kimberly A.; Lewit, Peter G.; Nadeau, Megan A.; Wood, Douglas A.; Parker, Castleton E.

    2014-01-01

    Detailed bathymetric maps of the sea floor in Rhode Island and Block Island Sounds are of great interest to the New York, Rhode Island, and Massachusetts research and management communities because of this area's ecological, recreational, and commercial importance. Geologically interpreted digital terrain models from individual surveys provide important benthic environmental information, yet many applications of this information require a geographically broader perspective. For example, individual surveys are of limited use for the planning and construction of cross-sound infrastructure, such as cables and pipelines, or for the testing of regional circulation models. To address this need, we integrated 14 contiguous multibeam bathymetric datasets that were produced by the National Oceanic and Atmospheric Administration during charting operations into one digital terrain model that covers much of Block Island Sound and extends eastward across Rhode Island Sound. The new dataset, which covers over 1244 square kilometers, is adjusted to mean lower low water, gridded to 4-meter resolution, and provided in Universal Transverse Mercator Zone 19, North American Datum of 1983 and geographic World Geodetic Survey of 1984 projections. This resolution is adequate for sea-floor feature and process interpretation but is small enough to be queried and manipulated with standard Geographic Information System programs and to allow for future growth. Natural features visible in the data include boulder lag deposits of winnowed Pleistocene strata, sand-wave fields, and scour depressions that reflect the strength of oscillating tidal currents and scour by storm-induced waves. Bedform asymmetry allows interpretations of net sediment transport. Anthropogenic features visible in the data include shipwrecks and dredged channels. Together the merged data reveal a larger, more continuous perspective of bathymetric topography than previously available, providing a fundamental framework for

  10. Long Island Solar Farm

    Energy Technology Data Exchange (ETDEWEB)

    Anders, R.

    2013-05-01

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  11. Sakhalin Island terrain intelligence

    Science.gov (United States)

    U.S. Geological Survey Military Geology Branch

    1943-01-01

    This folio of maps and explanatory tables outlines the principal terrain features of Sakhalin Island. Each map and table is devoted to a specialized set of problems; together they cover the subjects of terrain appreciation, climate, rivers, water supply, construction materials, suitability for roads, suitability for airfields, fuels and other mineral resources, and geology. In most cases, the map of the island is divided into two parts: N. of latitude 50° N., Russian Sakhalin, and south of latitude 50° N., Japanese Sakhalin or Karafuto. These maps and data were compiled by the United States Geological Survey during the period from March to September, 1943.

  12. Method of installing subsurface barrier

    Science.gov (United States)

    Nickelson, Reva A.; Richardson, John G.; Kostelnik, Kevin M.; Sloan, Paul A.

    2007-10-09

    Systems, components, and methods relating to subterranean containment barriers. Laterally adjacent tubular casings having male interlock structures and multiple female interlock structures defining recesses for receiving a male interlock structure are used to create subterranean barriers for containing and treating buried waste and its effluents. The multiple female interlock structures enable the barriers to be varied around subsurface objects and to form barrier sidewalls. The barrier may be used for treating and monitoring a zone of interest.

  13. 1957 Aleutian Islands, USA Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The magnitude 8.6 (Mw) earthquake occurred south of the Andreanof Islands, in the Aleutian Islands. It generated an 8-meter tsunami that did great damage on Adak...

  14. Gulf Island National Wildlife Refuges

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document provides a brief history and describes physical features of the Gulf Island National Wildlife Refuges. The Gulf Island National Wildlife Refuges...

  15. Monte Carlo simulation of V/III flux ratio influence on GaAs island nucleation during MBE

    Science.gov (United States)

    Ageev, O. A.; Solodovnik, M. S.; Balakirev, S. V.; Mikhaylin, I. A.

    2016-02-01

    The kinetic Monte Carlo simulation of GaAs/GaAs(001) molecular beam epitaxial growth considering V/III flux ratio influence on nucleating island characteristics is presented. It is shown that the island density increases with the surface coverage increase and reaches saturation after deposition of ∼0.1 monolayer of GaAs. The increase of V/III flux ratio from 3 to 40 leads to the increase of the island density from 1.9-1012 to 2.6-1012 cm-2. At the same time the average size decreases from 4.4 to 4.1 nm. The island size distribution function narrows with V/III flux ratio increase. This is attributed to the shortage of gallium atoms in comparison with deposited arsenic molecules that prevents large island formation and leads to the dramatic growth of little island concentration. The simulation demonstrates good agreement with experimental results.

  16. Skin barrier in rosacea.

    Science.gov (United States)

    Addor, Flavia Alvim Sant'Anna

    2016-01-01

    Recent studies about the cutaneous barrier demonstrated consistent evidence that the stratum corneum is a metabolically active structure and also has adaptive functions, may play a regulatory role in the inflammatory response with activation of keratinocytes, angiogenesis and fibroplasia, whose intensity depends primarily on the intensity the stimulus. There are few studies investigating the abnormalities of the skin barrier in rosacea, but the existing data already show that there are changes resulting from inflammation, which can generate a vicious circle caused a prolongation of flare-ups and worsening of symptoms. This article aims to gather the most relevant literature data about the characteristics and effects of the state of the skin barrier in rosacea. PMID:26982780

  17. Fuzzy barrier distributions

    International Nuclear Information System (INIS)

    Heavy-ion collisions often produce a fusion barrier distribution with structures displaying a fingerprint of couplings to highly collective excitations [1]. Basically the same distribution can be obtained from large-angle quasi-elastic scattering, though here the role of the many weak direct-reaction channels is unclear. For 20Ne + 90Zr we have observed the barrier structures expected for the highly deformed neon projectile, but for 20Ne + 92Zr we find completely smooth distribution (see Fig.1). We find that transfer channels in these systems are of similar strength but single particle excitations are significantly stronger in the latter case. They apparently reduce the 'resolving power' of the quasi-elastic channel, what leads to smeared out, or 'fuzzy' barrier distribution. This is the first case when such a phenomenon has been observed.(author)

  18. Islanded operation of distribution networks

    International Nuclear Information System (INIS)

    This report summarises the results of a study assessing the benefits and risks to distribution network of generator islanding and examining the technical, commercial and regulatory changes required to facilitate the operation of islanding. The background to the study is traced, and details are given of a literature review, the technical criteria for operating sections of the network in islanding mode, and the impact of islanding on trading. Case studies and a detailed implementation plan, data acquisition, and commercial incentives are discussed

  19. Islanded operation of distribution networks

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    This report summarises the results of a study assessing the benefits and risks to distribution network of generator islanding and examining the technical, commercial and regulatory changes required to facilitate the operation of islanding. The background to the study is traced, and details are given of a literature review, the technical criteria for operating sections of the network in islanding mode, and the impact of islanding on trading. Case studies and a detailed implementation plan, data acquisition, and commercial incentives are discussed.

  20. Marketing plan for Kuuskajaskari Island

    OpenAIRE

    XIE, JUANJUAN

    2009-01-01

    Marketing palan for Kuuskajaskari Island. ‡b Kuuskajaskari Island owned by the town of Rauma. Marketing plan should help the entrepreneurs of the islands to create services that target groups want and promote them by using the efficient marketing mix. The theoretical part consists of nature of tourism industry, travel consumers in general, then focus on Rauma areas and its island as targeted destination. Data was gathered from different official Finnish websites, books and from Sanni-Mari Aal...