Sample records for island iceberg formation
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2002-01-01
Almost an iceberg 'nursery,' icebergs continue to break away from the Ross Ice Shelf in Antarctica. This image from the MODerate-resolution Imaging Spectroradiometer (MODIS) aboard the Terra spacecraft, shows the level of activity along the shelf near Ross Island on September 21, 2000. The B-15 fragments are remnants of the huge iceberg (nearly 4,250 sqare miles) which broke away from the Antarctic shelf in late March 2000. Slightly visible is the line where iceberg B-20 broke away from the shelf in the last week of September. Cracks in the Antarctic ice shelf are closely observed by satellite and are of interest to scientists studying the potential effects of global warming. This true-color image was produced using MODIS bands 1, 3, and 4. Image by Brian Montgomery, NASA GSFC; data courtesy MODIS Science Team
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Directory of Open Access Journals (Sweden)
Anna J. Crawford
2018-04-01
Full Text Available Icebergs and ice islands (large, tabular icebergs are challenging targets to survey due to their size, mobility, remote locations, and potentially difficult environmental conditions. Here, we assess the precision and utility of aerial photography surveying with structure-from-motion multi-view stereo photogrammetry processing (SfM and vessel-based terrestrial laser scanning (TLS for iceberg deterioration detection and mass estimation. For both techniques, we determine the minimum amount of change required to reliably resolve iceberg deterioration, the deterioration detection threshold (DDT, using triplicate surveys of two iceberg survey targets. We also calculate their relative uncertainties for iceberg mass estimation. The quality of deployed Global Positioning System (GPS units that were used for drift correction and scale assignment was a major determinant of point cloud precision. When dual-frequency GPS receivers were deployed, DDT values of 2.5 and 0.40 m were calculated for the TLS and SfM point clouds, respectively. In contrast, values of 6.6 and 3.4 m were calculated when tracking beacons with lower-quality GPS were used. The SfM dataset was also more precise when used for iceberg mass estimation, and we recommend further development of this technique for iceberg-related end-uses.
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Iceberg incursions across Campbell Plateau
International Nuclear Information System (INIS)
Northcote, L.; Neil, H.; Carter, L.
1999-01-01
The last reported sighting of icebergs off eastern New Zealand was on 28th October, 1892, at the Chatham Islands. Prior to that time, the SW Pacific Ocean periodically hosted flotillas of icebergs, as revealed by a palaeoceanographic analysis of 8 cores from the Campbell Plateau. Stable isotope stratigraphy, coupled with down-core measurements of magnetic susceptibility, grain size, calcium carbonate and ice-rafted debris, highlight climate-related fluctuations in iceberg activity back to at least marine isotope stage (MIS) 6 - our longest complete record. (author)
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Summer Decay Processes in a Large Tabular Iceberg
Wadhams, P.; Wagner, T. M.; Bates, R.
2012-12-01
Summer Decay Processes in a Large Tabular Iceberg Peter Wadhams (1), Till J W Wagner(1) and Richard Bates(2) (1) Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK (2) Scottish Oceans Institute, School of Geography and Geosciences, University of St Andrews, St. Andrews, Scotland KY16 9AL We present observational results from an experiment carried out during July-August 2012 on a giant grounded tabular iceberg off Baffin Island. The iceberg studied was part of the Petermann Ice Island B1 (PIIB1) which calved off the Petermann Glacier in NW Greenland in 2010. Since 2011 it has been aground in 100 m of water on the Baffin Island shelf at 69 deg 06'N, 66 deg 06'W. As part of the project a set of high resolution GPS sensors and tiltmeters was placed on the ice island to record rigid body motion as well as flexural responses to wind, waves, current and tidal forces, while a Waverider buoy monitored incident waves and swell. On July 31, 2012 a major breakup event was recorded, with a piece of 25,000 sq m surface area calving off the iceberg. At the time of breakup, GPS sensors were collecting data both on the main berg as well as on the newly calved piece, while two of us (PW and TJWW) were standing on the broken-out portion which rose by 0.6 m to achieve a new isostatic equilibrium. Crucially, there was no significant swell at the time of breakup, which suggests a melt-driven decay process rather than wave-driven flexural break-up. The GPS sensors recorded two disturbances during the hour preceding the breakup, indicative of crack growth and propagation. Qualitative observation during the two weeks in which our research ship was moored to, or was close to, the ice island edge indicates that an important mechanism for summer ablation is successive collapses of the overburden from above an unsupported wave cut, which creates a submerged ram fringing the berg. A model of buoyancy stresses induced by
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The record of iceberg roll generated waves from sediments and seismics
Rosser, N. J.; Szczucinski, W.; Strzelecki, M.; Long, A. J.; Norman, E. C.; Dunning, S.; Drewniak, M.
2013-12-01
Iceberg-roll tsunamis in coastal settings have been observed to generate significant local waves, that hold potential to be recorded in coastal depositional records. Capturing the past magnitude and frequency of such events remains challenging, hindered by a lack of a good understanding of the nature, recurrence and scale of iceberg rolls, and more specifically those rolls that generate waves. Here we consider the sedimentary evidence for iceberg rolls in West Central Greenland, based upon survey of depositional environments in a range of open and confined coastal environments. We examine both an open 80 km fjord setting, and a series of confined ice-marginal beaches. We combine a detailed interpretation of sediment deposits from shore-normal transects with wider-scale high-resolution terrestrial laser scanning of sediments. Our sites - Vaigat, which separates Disko Island from the Nussuaq Peninsular, and the northern shore of Icefjord - both have a recent history of tsunamis, triggered variously by large rock avalanches, landslides and iceberg rolls. Icebergs in Vaigat and Icefjord are observed to undergo frequent failure and roll, generating - where circumstances permit - nearshore waves of meter-scale. To obtain a more detailed understanding of the likely recurrence of such iceberg roll waves and to consider their influence upon the preserved sedimentary record, we undertook an intensive 2-month monitoring campaign during sea-ice free conditions in summer 2013 to determine the patterns in the location, magnitude, frequency and timing of iceberg roll waves. Innovatively, using microseismic monitoring combined with time-lapse photography and weather monitoring, we derive a first-order model of the occurrence of iceberg roll waves. We then use this to inform our interpretation of deposits in these two environments, and consider the presence and absence of records of iceberg roll deposits in such settings. The study was funded by Polish National Science Centre grant
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Marson, Juliana M.; Myers, Paul G.; Hu, Xianmin
2017-04-01
The Atlantic Meridional Overturning Circulation (AMOC) is well known for carrying heat from low to high latitudes, moderating local temperatures. Numerical studies have examined the AMOC's variability under the influence of freshwater input to subduction and deep convections sites. However, an important source of freshwater has often been overlooked or misrepresented: icebergs. While liquid runoff decreases the ocean salinity near the coast, icebergs are a gradual and remote source of freshwater - a difference that affects sea ice cover, temperature, and salinity distribution in ocean models. Icebergs originated from the Greenland ice sheet, in particular, can affect the subduction process in Labrador Sea by decreasing surface water density. Our study aims to evaluate the distribution of icebergs originated from Greenland and their contribution to freshwater input in the North Atlantic. To do that, we use an interactive iceberg module coupled with the Nucleus for European Modelling of the Ocean (NEMO v3.4), which will calve icebergs from Greenland according to rates established by Bamber et al. (2012). Details on the distribution and trajectory of icebergs within the model may also be of use for understanding potential navigation threats, as shipping increases in northern waters.
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Antarctic icebergs distributions 1992-2014
Tournadre, J.; Bouhier, N.; Girard-Ardhuin, F.; Rémy, F.
2016-01-01
Basal melting of floating ice shelves and iceberg calving constitute the two almost equal paths of freshwater flux between the Antarctic ice cap and the Southern Ocean. The largest icebergs (>100 km2) transport most of the ice volume but their basal melting is small compared to their breaking into smaller icebergs that constitute thus the major vector of freshwater. The archives of nine altimeters have been processed to create a database of small icebergs (law of slope -1.52 ± 0.32 close to the -3/2 laws observed and modeled for brittle fragmentation. The global volume of ice and its distribution between the ocean basins present a very strong interannual variability only partially explained by the number of large icebergs. Indeed, vast zones of the Southern Ocean free of large icebergs are largely populated by small iceberg drifting over thousands of kilometers. The correlation between the global small and large icebergs volumes shows that small icebergs are mainly generated by large ones breaking. Drifting and trapping by sea ice can transport small icebergs for long period and distances. Small icebergs act as an ice diffuse process along large icebergs trajectories while sea ice trapping acts as a buffer delaying melting.
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Directory of Open Access Journals (Sweden)
Yan Gao
2014-01-01
Full Text Available The increasing marine activities in Arctic area have brought growing interest in ship-iceberg collision study. The purpose of this paper is to study the iceberg geometry shape effect on the collision process. In order to estimate the sensitivity parameter, five different geometry iceberg models and two iceberg material models are adopted in the analysis. The FEM numerical simulation is used to predict the scenario and the related responses. The simulation results including energy dissipation and impact force are investigated and compared. It is shown that the collision process and energy dissipation are more sensitive to iceberg local shape than other factors when the elastic-plastic iceberg material model is applied. The blunt iceberg models act rigidly while the sharp ones crush easily during the simulation process. With respect to the crushable foam iceberg material model, the iceberg geometry has relatively small influence on the collision process. The spherical iceberg model shows the most rigidity for both iceberg material models and should be paid the most attention for ice-resist design for ships.
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Warren, S. G.
2017-12-01
Ordinary icebergs of meteoric glacier ice appear bluish-white, i.e. intermediate in color between the white of snow and the blue of pure ice, depending on the bubble content. However, clear dark bubble-free icebergs are occasionally seen in the Antarctic Ocean; they originate from freezing of seawater to the base of ice shelves. On parts of the Amery Ice Shelf, frozen seawater contributes up to one-third of the ice-shelf thickness. Many of the icebergs produced by the Amery are therefore composite icebergs; the upper part consists of meteoric glacier ice from snowfall, but the lower part is frozen seawater ("marine ice"). When these icebergs capsize, the marine ice is exposed to view; it can be accessed for study in springtime when the icebergs are embedded in shorefast sea ice. The marine ice varies in color from blue to green depending on the content of dissolved organic matter. The color is therefore an indicator of biological productivity in the seawater from which the ice froze. To infer processes at the ice-shelf base, these icebergs may be examined and cored for spectral reflectance, hydrogen and oxygen isotopes, organic matter, particles, and distribution of cracks and stripes. Seasonal and interannual variations may be quantified from samples collected along the marine ice-growth trajectory at the meteoric/marine-ice interface. The scale of small turbulent eddies at the ice-shelf base, which govern the transfer of heat between ocean and ice, can be inferred from the size of scallops in the iceberg surface (typically a few centimeters). Dark stripes within meteoric ice result from tension-cracks at the grounding line, forming basal crevasses that fill suddenly with seawater; their width, spacing, and salinity can give clues to processes at the grounding line. Results will be shown from icebergs sampled on Australian expeditions near Davis and Mawson stations. Marine ice is more readily accessed by sampling an iceberg than by drilling through an ice shelf
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Ship-Iceberg Discrimination in Sentinel-2 Multispectral Imagery by Supervised Classification
DEFF Research Database (Denmark)
Heiselberg, Peder; Heiselberg, Henning
2017-01-01
. It discriminates between objects like ships, islands, wakes, and icebergs, ice floes, and clouds with accuracy better than 90%. Pan-sharpening the infrared bands leads to classification and discrimination of ice floes and clouds better than 95%. For complex images with abundant ice floes or clouds, however...
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An Implementation of Icebergs in CICE
Energy Technology Data Exchange (ETDEWEB)
Comeau, Darin S. [Los Alamos National Laboratory
2012-06-25
There is an estimated global iceberg calving flux of {approx} 2300 Gt yr{sup -1}, about 90% of which occurs in the Antarctic. Icebergs provide an important vehicle for freshwater injection into the polar oceans, an estimated 60-80% of net freshwater flux from land ice to oceans in the Antarctic. Icebergs interact dynamically with surrounding sea ice, potentially affecting marine eco systems. Icebergs lose mass primarily through three mechanisms, described by empirical relations: (1) Basal melting - turbulence due to differences in oceanic and iceberg motion (also function of difference in temperature between ocean and iceberg); (2) Lateral melting - buoyant convection along sidewalls of iceberg (function of ocean temperature); and (3) Erosion due to waves (function of sea state and ocean temperature). We have incorporated an iceberg parameterization into the CICE model where sea ice responds to the icebergs, rather than being a static forcing term. Icebergs produce highly localized anomalies in sea ice concentration, thickness, and strength. Summer sea ice meltback limits these effects. Icebergs shed freshwater as they move, transporting freshwater away from the coast.
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Icebergs, sea ice, blue carbon and Antarctic climate feedbacks.
Barnes, David K A; Fleming, Andrew; Sands, Chester J; Quartino, Maria Liliana; Deregibus, Dolores
2018-06-28
Sea ice, including icebergs, has a complex relationship with the carbon held within animals (blue carbon) in the polar regions. Sea-ice losses around West Antarctica's continental shelf generate longer phytoplankton blooms but also make it a hotspot for coastal iceberg disturbance. This matters because in polar regions ice scour limits blue carbon storage ecosystem services, which work as a powerful negative feedback on climate change (less sea ice increases phytoplankton blooms, benthic growth, seabed carbon and sequestration). This resets benthic biota succession (maintaining regional biodiversity) and also fertilizes the ocean with nutrients, generating phytoplankton blooms, which cascade carbon capture into seabed storage and burial by benthos. Small icebergs scour coastal shallows, whereas giant icebergs ground deeper, offshore. Significant benthic communities establish where ice shelves have disintegrated (giant icebergs calving), and rapidly grow to accumulate blue carbon storage. When 5000 km 2 giant icebergs calve, we estimate that they generate approximately 10 6 tonnes of immobilized zoobenthic carbon per year (t C yr -1 ). However, their collisions with the seabed crush and recycle vast benthic communities, costing an estimated 4 × 10 4 t C yr -1 We calculate that giant iceberg formation (ice shelf disintegration) has a net potential of approximately 10 6 t C yr -1 sequestration benefits as well as more widely known negative impacts.This article is part of the theme issue 'The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change'. © 2018 The Authors.
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An analytical model of iceberg drift
Eisenman, I.; Wagner, T. J. W.; Dell, R.
2017-12-01
Icebergs transport freshwater from glaciers and ice shelves, releasing the freshwater into the upper ocean thousands of kilometers from the source. This influences ocean circulation through its effect on seawater density. A standard empirical rule-of-thumb for estimating iceberg trajectories is that they drift at the ocean surface current velocity plus 2% of the atmospheric surface wind velocity. This relationship has been observed in empirical studies for decades, but it has never previously been physically derived or justified. In this presentation, we consider the momentum balance for an individual iceberg, which includes nonlinear drag terms. Applying a series of approximations, we derive an analytical solution for the iceberg velocity as a function of time. In order to validate the model, we force it with surface velocity and temperature data from an observational state estimate and compare the results with iceberg observations in both hemispheres. We show that the analytical solution reduces to the empirical 2% relationship in the asymptotic limit of small icebergs (or strong winds), which approximately applies for typical Arctic icebergs. We find that the 2% value arises due to a term involving the drag coefficients for water and air and the densities of the iceberg, ocean, and air. In the opposite limit of large icebergs (or weak winds), which approximately applies for typical Antarctic icebergs with horizontal length scales greater than about 12 km, we find that the 2% relationship is not applicable and that icebergs instead move with the ocean current, unaffected by the wind. The two asymptotic regimes can be understood by considering how iceberg size influences the relative importance of the wind and ocean current drag terms compared with the Coriolis and pressure gradient force terms in the iceberg momentum balance.
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Seismology on drifting icebergs: Catching earthquakes, tsunamis, swell, and iceberg music
Okal, E. A.; Macayeal, D. R.
2006-12-01
For the past 3 years, we have operated seismometers on large icebergs either parked or drifting in the Ross Sea, with an additional station at Nascent, where the next section of the Ross Ice Shelf is expected to calf. Apart from their primary goal of studying in situ tremor generated inside the ice, presumed to arise during collisions and fragmentation, our stations have functioned as teleseismic observatories, despite a noisy environment in the 20-100 mHz frequency band, corresponding to the free bobbing and rolling of the icebergs. As expected, both P and Rayleigh waves from distant earthquakes are recorded on the vertical channels as unperturbed ground motion, with acceptable values of energy flux (P) or magnitude (Rayleigh); however, due to noise level at mantle periods, only Rayleigh waves from the largest events (Sumatra 2004; Nias 2005) could be quantified meaningfully. T waves from distant earthquakes along the EPR can be recorded, but the acoustic-to-seismic transition at the ice boundary is less effcient than at typical island stations. The 2004 Sumatra tsunami was recorded on all 3 components at the 3 stations; the inferred amplitudes (about 15 cm vertical and 1.3 m horizontal, peak-to-peak) are in general agreement with global simulations, and suggest that the bergs rode the tsunami without intrinsic deformation; a small tsunami is also detected for the Macquarie earthquake of 23 Dec. 2004. Our stations regularly recorded long wavetrains in the 40-60 mHz range, dispersed under the deep-water approximation, and corresponding to sea swell propagating across the entire ocean from major storms in the Northern and Equatorial Pacific. In the case of a major depression in the Gulf of Alaska in Late October 2005, recorded on the ice 6 days later, Iceberg B-15A underwent at the same time a severe fragmentation, leading to legitimate speculation on the role of storm waves in triggering its break-up. Finally, our stations recorded a large number of local signals
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DEFF Research Database (Denmark)
Deriabyn, M. V.; Hjorth, Poul G.
2009-01-01
We study the stability and dynamics of melting icebergs. Specifically, we address the 'toppling' or 'rollover' observed for floating icebergs. The rollover is thought to occur because the ocean melts the iceberg from below, causing its overall mass and mass distribution to change with time. We...... model the evolution of equilibrium positions for a general homogeneous body afloat in an ideal fluid, as this homogeneous body is subjected to 'melting', i.e. a slow removal of material from the submerged part. If this process is the dominating melting mechanism, can the likelihood of a toppling...
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Greenland iceberg melt variability from high-resolution satellite observations
Directory of Open Access Journals (Sweden)
E. M. Enderlin
2018-02-01
Full Text Available Iceberg discharge from the Greenland Ice Sheet accounts for up to half of the freshwater flux to surrounding fjords and ocean basins, yet the spatial distribution of iceberg meltwater fluxes is poorly understood. One of the primary limitations for mapping iceberg meltwater fluxes, and changes over time, is the dearth of iceberg submarine melt rate estimates. Here we use a remote sensing approach to estimate submarine melt rates during 2011–2016 for 637 icebergs discharged from seven marine-terminating glaciers fringing the Greenland Ice Sheet. We find that spatial variations in iceberg melt rates generally follow expected patterns based on hydrographic observations, including a decrease in melt rate with latitude and an increase in melt rate with iceberg draft. However, we find no longitudinal variations in melt rates within individual fjords. We do not resolve coherent seasonal to interannual patterns in melt rates across all study sites, though we attribute a 4-fold melt rate increase from March to April 2011 near Jakobshavn Isbræ to fjord circulation changes induced by the seasonal onset of iceberg calving. Overall, our results suggest that remotely sensed iceberg melt rates can be used to characterize spatial and temporal variations in oceanic forcing near often inaccessible marine-terminating glaciers.
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The breakup of large tabular icebergs - direct observations and theoretical considerations
Wadhams, P.
2013-12-01
Peter Wadhams and Till Wagner Dept. of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge. We review the factors governing the stability, dynamics and decay of icebergs and describe areas where current models are inadequate. These include questions such as draft changes in capsizing icebergs; iceberg trajectory modelling; the melt rate of the ice underside and ways of reducing it; and wave-induced flexure and its role in the break-up of tabular icebergs. In July 2012 the authors worked on a very large (42 sq km) tabular iceberg in Baffin Bay, which had calved from the Petermann Glacier in NW Greenland. We measured incoming swell spectrum and the iceberg response; also the role of buoyancy forces due to erosion of a waterline wave cut and the creation of an underwater ram. The iceberg broke up while we were on it, allowing an instrumental measurement of the calving event. The experiments were included in the BBC-2 film 'Operation Iceberg' shown on Nov 1 2012 and repeated on Nov 18. We conclude that two processes interacted in the break-up event: increased bending stress due to buoyancy of underwater rams; and direct flexural strain due to incidence of ocean swell. Implications for icebergs in the open sea are estimated.
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Structural and Sensory Characterization of Novel Sesquiterpene Lactones from Iceberg Lettuce.
Mai, Franziska; Glomb, Marcus A
2016-01-13
Lactuca sativa var. capitate (iceberg lettuce) is a delicious vegetable and popular for its mild taste. Nevertheless, iceberg lettuce is a source of bitter substances, such as the sesquiterpene lactones. Chemical investigations on the n-butanol extract led to the isolation of three novel sesquiterpene lactones. All compounds were isolated by multilayer countercurrent chromatography followed by preparative high-performance liquid chromatography. The structures were verified by means of spectroscopic methods, including NMR and mass spectrometry techniques. For the first time 11ß,13-dihydrolactucin-8-O-sulfate (jaquinelin-8-O-sulfate) was structurally elucidated and identified in plants. In addition, the sesquiterpene lactones cichorioside B and 8-deacetylmatricarin-8-O-sulfate were identified as novel ingredients of iceberg lettuce. Further flowering plants in the daisy family Asteraceae were examined for the above three compounds. At least one of the compounds was identified in nine plants. The comparison between the lettuce butt end and the leaves of five types of the Cichorieae tribe showed an accumulation of the compounds in the butt end. Further experiments addressed the impact of sesquiterpene lactones on color formation and bitter taste.
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PENDEKATAN ICEBERG DALAM PEMBELAJARAN PEMBAGIAN PECAHAN DI SEKOLAH DASAR
Saleh Haji
2013-01-01
Makalah ini membahas pengaruh pendekatan iceberg pada pembelajaran pembagian pecahan di Sekolah Dasar.Tahapan pendekatan iceberg tersebut sebagai berikut: 1. Orientasi lingkungan secara matematis, 2. Model material, 3. Pembuatan pondasi, dan 4. Matematika formal. Sedangkan topik pembagian pecahan yang dibahas terdiri atas: pembagian bilangan bulat oleh pecahan, pembagian pecahan oleh bilangan bulat, dan pembagian pecahan dengan pecahan. Penggunakan pendekatan iceberg dalam pembelajaran matema...
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Green Icebergs: a Problem in Geophysics and Atmospheric Optics
Lee, Raymond L., Jr.
The curious phenomenon of green icebergs has intrigued polar travelers for centuries. Although some researchers have speculated that this ice contains colorants, an investigator who has actually examined a green iceberg sample found very little intrinsically green material. This supports our idea that at least some green icebergs are due to the combined effects of reddened sunlight illuminating intrinsically blue-green ice. In this case, "intrinsic" refers to the blue-green absorption minimum of pure ice. Naturally occurring ice containing a few inclusions that scatter light with little or no spectral selectivity also exhibits this same absorption minimum. Artists' and travelers' accounts of colored ice tell us that, while remarkable, it is not uncommon. The few 20th-century scientific reports on green icebergs agree with the earlier accounts on the unusual denseness and translucence of highly colored ice. We see the same correlation between ice colors and ice denseness in accounts of glacier ice. When we examine the optical properties of dense, relatively bubble-free ice, we find that we can nearly match its reflectance spectra with either of two multiple -scattering models for ice optics. If we pair these models' reflectance spectra with estimates of polar daylight spectra, we can duplicate the observed colors of green icebergs. Our psychophysical model of human color perception is the 1931 CIE chromaticity space. Although this form of colorimetry has some perceptual faults, we may nonetheless use it as a means of comparing the observed and theoretical colors of green icebergs. In the absence of in situ spectral reflectance measurements, we use video digitizing and spectrodensitometry to extract colorimetric information from color photographs of green icebergs. However, before using these remote sensing techniques, first we must solve the intricate problem of calibrating them against known color standards. After doing this, we find that our analyses of green
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Iceberg Harmonic Tremor, Seismometer Data, Antarctica, Version 1
National Aeronautics and Space Administration — Seismometers were placed on a 25 km by 50 km iceberg called C16 in the Ross Sea, Antarctica, to identify the Iceberg harmonic Tremor (IHT) source mechanism and to...
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Modeling the drift of massive icebergs to the subtropical North Atlantic
Condron, A.; Hill, J. C.
2013-12-01
New evidence from high-resolution seafloor bathymetry data indicates that massive (>300m thick) icebergs from the Laurentide Ice Sheet (LIS) drifted south to the tip of Florida during the last deglaciation. This finding is particularly exciting as it contradicts evidence from marine sediments that icebergs were mainly confined to the subpolar North Atlantic (50 - 70N) at this time. Indeed, the freshwater released from icebergs melting in the subpolar gyre is repeatedly cited as a main trigger for a slow-down of the Atlantic MOC in the past, and the possible cause of any climate cooling related to the melting of the Greenland Ice Sheet in the future. Using a sophisticated iceberg model (MITberg), coupled to a high (18-km; 1/6 deg.) resolution ocean model (MITgcm), we investigate the ocean circulation dynamics required to allow icebergs to drift to the southern tip of Florida. We find that icebergs only reach this location if they turn right at the Grand Banks of Newfoundland, and stay inshore of the Gulf Stream all the way to Florida. Modern-day circulation dynamics do not readily allow this to happen as cold, southward flowing, Labrador Current Water (important for iceberg survival) has little penetration south of Cape Hatteras. However, when a liquid meltwater flood is released from Hudson Bay at the same time, icebergs are rapidly transported (inshore of the Gulf Stream) in a narrow, buoyant, coastal current all the way to southern Florida. The meltwater and icebergs result in a significant freshening of the subtropical North Atlantic and weaken the strength of the Gulf Stream, suggesting such an event would have a large cooling effect on climate. We are only able to simulate the flow of meltwater and icebergs to the subtropics by modeling ocean circulation at a resolution that is 5 - 10 times higher than the majority of existing paleoclimate models; at lower resolutions the narrow, coastal boundary currents important for iceberg transport to the subtropics are
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A role for icebergs in the 8.2 ka climate event
Wiersma, A.P.; Jongma, J.I.
2009-01-01
We investigate the potential role of icebergs in the 8.2 ka climate event, using a coupled climate model equipped with an iceberg component. First, we evaluate the effect of a large iceberg discharge originating from the decaying Laurentide ice sheet on ocean circulation, compared to a release of an
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2014-08-01
Iceberg Feature ones—another documented cognitive bias that is largely subconscious . A final opportunity lost by not having a forward geographic presence...leading to a subtle bias towards the tip-of-the-iceberg systems that most individuals have more famil- iarity with from their tactical backgrounds...as soon as possible to maintain career viability in a system biased more towards tactical achievement. Acknowledge That the Heart of Operational C2 Is
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Ford, Murray R.; Kench, Paul S.
2014-06-01
In 1905, a devastating typhoon hit Nadikdik Atoll (5°54‧ N and 172°09‧ E) in the southern Marshall Islands. Evidence suggests that large sections of reef islands on Nadikdik were overwashed and destroyed. Comparison of aerial photographs taken in 1945 and modern satellite imagery provides a unique record of the geomorphic adjustment of islands after the typhoon. Between 1945 and 2010 the vegetated area of islands on Nadikdik grew from 0.74 to 0.90 km2. Observed changes to Nadikdik reef islands manifested through a range of styles and were largely accretionary. Of note, the formation of a new island was tracked from an embryonic deposit to a fully vegetated and stable island over a 61 year period. Similarly, a number of previously discrete islands have agglomerated and formed a single larger island. These changes were rapid and indicate that reef island formation can occur quickly. Evidence suggests that despite the typhoon occurring over a century ago the geomorphic adjustment of islands is still on-going.
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Seeing from Space: What Icebergs Can Tell Us About Ice-ocean Interactions
Scheick, J.; Enderlin, E. M.; Hamilton, G. S.
2017-12-01
Icebergs are an important component of the ice-ocean system, yet until recently they have remained the focus of relatively few studies. Icebergs are an important distributed freshwater and nutrient source and can pose significant hazards for navigation and infrastructure, warranting further study. Importantly, icebergs are also easily observable en masse using satellite imagery and other remote sensing platforms, allowing for the collection of large datasets from already existing archives. Here we present some of the many ways that remotely sensed icebergs can be used to inform our understanding of ice-ocean interactions, as well as some of the limitations of these methods and what information is still needed. We will explore the size and spatial distribution of icebergs through time and what that can tell us about the calving behavior of the parent glacier and/or ocean-driven melting below the waterline. We will also explore the use of icebergs as depth finders and drifters to infer bathymetry and components of fjord circulation, respectively.
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The Intensity, Directionality, and Statistics of Underwater Noise From Melting Icebergs
Glowacki, Oskar; Deane, Grant B.; Moskalik, Mateusz
2018-05-01
Freshwater fluxes from melting icebergs and glaciers are important contributors to both sea level rise and anomalies of seawater salinity in polar regions. However, the hazards encountered close to icebergs and glaciers make it difficult to quantify their melt rates directly, motivating the development of cryoacoustics as a remote sensing technique. Recent studies have shown a qualitative link between ice melting and the accompanying underwater noise, but the properties of this signal remain poorly understood. Here we examine the intensity, directionality, and temporal statistics of the underwater noise radiated by melting icebergs in Hornsund Fjord, Svalbard, using a three-element acoustic array. We present the first estimate of noise energy per unit area associated with iceberg melt and demonstrate its qualitative dependence on exposure to surface current. Finally, we show that the analysis of noise directionality and statistics makes it possible to distinguish iceberg melt from the glacier terminus melt.
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Spencer-Devlin, Marni
2013-01-01
The Iceberg Principles connect spirituality and science in a way that proves that the energy, which is the substance of the Universe, really is Love - not sweet, syrupy, candy-and-roses kind of love but the most powerful force in the Universe. Love without expression is meaningless. This is why the Big Bang was the only logical outcome. Love had to become reflected in dimensionality. With the Big Bang a 4:96 ratio was created between the dimensional and non-dimensional realms. This ratio between visibility and invisibility the ratio of an iceberg also applies to human beings. Only four percent of who we are is visible. Our physical DNA describes us but it does not define us. What defines us are our characteristics, our gifts, and talents - the spiritual DNA. This is invisible but makes up ninety-six percent of who we are. Our talents are not accidental; our life purpose is to express them. Just as the Universe emerges into dimensionality, constantly creating galaxies at millions of miles a minute, we are al...
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Decontamination and survival of Enterobacteriaceae on shredded iceberg lettuce during storage.
Osaili, Tareq M; Alaboudi, Akram R; Al-Quran, Heba N; Al-Nabulsi, Anas A
2018-08-01
Enterobacteriaceae family can contaminate fresh produce at any stage of production either at pre-harvest or post-harvest stages. The objectives of the current study were to i) identify Enterobacteriaceae species on iceberg lettuce, ii) compare the decontamination efficiency of water, sodium hypochlorite (free chlorine 200 ppm), peroxyacetic acid (PA 80 ppm; Kenocid 2100 ® ) or their combinations and ionizing radiation against Enterobacteriaceae on shredded iceberg lettuce and iii) determine the survival of Enterobacteriaceae post-treatment storage of shredded iceberg lettuce at 4, 10 and 25 °C, for up to 7 days. Klebsiella pneumonia spp. pneumonia, Enterobacter cloacae, Klebsiella oxytoca, Pantoea spp., Leclercia adecarboxylata and Kluyvera ascorbate were identified on iceberg lettuce. No significant difference (P≥ 0.05) among Enterobacteriaceae survival after washing with water or sanitizing with sodium hypochlorite or Kenocid 2100 ® (reduction ≤ 0.6 log CFU/g) were found. Combined sanitizer treatments were more effective against Enterobacteriaceae than single washing/sanitizing treatments. Sanitization of iceberg lettuce with combined washing/sanitizing treatments reduced Enterobacteriaceae by 0.85-2.24 CFU/g. Post-treatment growth of Enterobacteriaceae during storage on samples sanitized with sodium hypochlorite and Kenocid 2100 ® was more than on samples washed with water. The D 10 -value of Enterobacteriaceae on shredded iceberg lettuce was 0.21 KGy. The reduction of Enterobacteriaceae populations on iceberg after gamma radiation (0.6 KGy) was 3 log CFU/g, however, Enterobacteriaceae counts increased post-irradiation storage by 4-5 log CFU/g. Therefore, washing shredded iceberg lettuce with combined sanitizing treatment (sodium hypochlorite/sodium hypochlorite, sodium hypochlorite/Kenocid 2100 ® , or Kenocid 2100 ® /Kenocid 2100 ® ) for total time of 6 min or exposing it to gamma irradiation (0.6 KGy) can decrease the risk of
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Tree island pattern formation in the Florida Everglades
Carr, Joel; D'Odorico, P.; Engel, Victor C.; Redwine, Jed
2016-01-01
The Florida Everglades freshwater landscape exhibits a distribution of islands covered by woody vegetation and bordered by marshes and wet prairies. Known as “tree islands”, these ecogeomorphic features can be found in few other low gradient, nutrient limited freshwater wetlands. In the last few decades, however, a large percentage of tree islands have either shrank or disappeared in apparent response to altered water depths and other stressors associated with human impacts on the Everglades. Because the processes determining the formation and spatial organization of tree islands remain poorly understood, it is still unclear what controls the sensitivity of these landscapes to altered conditions. We hypothesize that positive feedbacks between woody plants and soil accretion are crucial to emergence and decline of tree islands. Likewise, positive feedbacks between phosphorus (P) accumulation and trees explain the P enrichment commonly observed in tree island soils. Here, we develop a spatially-explicit model of tree island formation and evolution, which accounts for these positive feedbacks (facilitation) as well as for long range competition and fire dynamics. It is found that tree island patterns form within a range of parameter values consistent with field data. Simulated impacts of reduced water levels, increased intensity of drought, and increased frequency of dry season/soil consuming fires on these feedback mechanisms result in the decline and disappearance of tree islands on the landscape.
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Formation of intra-island grain boundaries in pentacene monolayers.
Zhang, Jian; Wu, Yu; Duhm, Steffen; Rabe, Jürgen P; Rudolf, Petra; Koch, Norbert
2011-12-21
To assess the formation of intra-island grain boundaries during the early stages of pentacene film growth, we studied sub-monolayers of pentacene on pristine silicon oxide and silicon oxide with high pinning centre density (induced by UV/O(3) treatment). We investigated the influence of the kinetic energy of the impinging molecules on the sub-monolayer growth by comparing organic molecular beam deposition (OMBD) and supersonic molecular beam deposition (SuMBD). For pentacene films fabricated by OMBD, higher pentacene island-density and higher polycrystalline island density were observed on UV/O(3)-treated silicon oxide as compared to pristine silicon oxide. Pentacene films deposited by SuMBD exhibited about one order of magnitude lower island- and polycrystalline island densities compared to OMBD, on both types of substrates. Our results suggest that polycrystalline growth of single islands on amorphous silicon oxide is facilitated by structural/chemical surface pinning centres, which act as nucleation centres for multiple grain formation in a single island. Furthermore, the overall lower intra-island grain boundary density in pentacene films fabricated by SuMBD reduces the number of charge carrier trapping sites specific to grain boundaries and should thus help achieving higher charge carrier mobilities, which are advantageous for their use in organic thin-film transistors.
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Blonski, Slawomir; Peterson, Craig
2006-01-01
Observations of icebergs are identified as one of the requirements for the GEOSS (Global Earth Observation System of Systems) in the area of reducing loss of life and property from natural and human-induced disasters. However, iceberg observations are not included among targets in the GEOSS 10-Year Implementation Plan, and thus there is an unfulfilled need for iceberg detection and tracking in the near future. Large Antarctic icebergs have been tracked by the National Ice Center and by the academic community using a variety of satellite sensors including both passive and active microwave imagers, such as SSM/I (Special Sensor Microwave/Imager) deployed on the DMSP (Defense Meteorological Satellite Program) spacecraft. Improvements provided in recent years by NASA and non-NASA satellite radars, scatterometers, and radiometers resulted in an increased number of observed icebergs and even prompted a question: Is The Number of Antarctic Icebergs Really Increasing? [D.G. Long, J. Ballantyne, and C. Bertoia, Eos, Transactions of the American Geophysical Union 83 (42): 469 & 474, 15 October 2002]. AMSR-E (Advanced Microwave Scanning Radiometer for the Earth Observing System) represents an improvement over SSM/I, its predecessor. AMSR-E has more measurement channels and higher spatial resolution than SSM/I. For example, the instantaneous field of view of the AMSR-E s 89-GHz channels is 6 km by 4 km versus 16 km by 14 km for SSM/I s comparable 85-GHz channels. AMSR-E, deployed on the Aqua satellite, scans across a 1450-km swath and provides brightness temperature measurements with nearglobal coverage every one or two days. In polar regions, overlapping swaths generate coverage up to multiple times per day and allow for creation of image time series with high temporal resolution. Despite these advantages, only incidental usage of AMSR-E data for iceberg tracking has been reported so far, none in an operational environment. Therefore, an experiment was undertaken in the RPC
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Kiyokawa, S.; Ito, T.; Ikehara, M.; Yamaguchi, K. E.; Naraoka, H.; Onoue, T.; Horie, K.; Sakamoto, R.; Aihara, Y.; Miki, T.
2013-12-01
The 3.2-3.1 Ga Dixon island-Cleaverville formations are well-preserved Banded Iron Formation (BIF) within hydrothermal oceanic sequence at oceanic island arc setting (Kiyokawa et al., 2002, 2006, 2012). The stratigraphy of the Dixon Island (3195+15Ma) -Cleaverville (3108+13Ma) formations shows the well preserved environmental condition at the Mesoarchean ocean floor. The stratigraphy of these formations are formed about volcano-sedimentary sequences with hydrothermal chert, black shale and banded iron formation to the top. Based on the scientific drilling of DXCL project at 2007 and 2011, detail lithology between BIF sequence was clearly understood. Four drilling holes had been done at coastal sites; the Dixon Island Formation is DX site (100m) and the Cleaverville Formation is CL2 (40m), CL1 (60m) and CL3 (200m) sites and from stratigraphic bottom to top. Coarsening and thickening upward black shale-BIF sequences are well preserved of the stratigraphy form the core samples. The Dixon Island Formation consists komatiite-rhyolite sequences with many hydrothermal veins and very fine laminated cherty rocks above them. The Cleaverville Formation contains black shale, fragments-bearing pyroclastic beds, white chert, greenish shale and BIF. The CL3 core, which drilled through BIF, shows siderite-chert beds above black shale identified before magnetite lamination bed. U-Pb SHRIMP data of the tuff in lower Dixon Island Formation is 3195+15 Ma and the pyroclastic sequence below the Cleaverville BIF is 3108+13 Ma. Sedimentation rate of these sequence is 2-8 cm/ 1000year. The hole section of the organic carbon rich black shales below BIF are similar amount of organic content and 13C isotope (around -30per mill). There are very weak sulfur MIF signal (less 0.2%) in these black shale sequence. Our result show that thick organic rich sediments may be triggered to form iron rich siderite and magnetite iron beds. The stratigraphy in this sequence quite resemble to other Iron
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A Model of Icebergs and Sea Ice in a Joint Continuum Framework
VaÅková, Irena; Holland, David M.
2017-11-01
The ice mélange, a mixture of sea ice and icebergs, often present in front of outlet glaciers in Greenland or ice shelves in Antarctica, can have a profound effect on the dynamics of the ice-ocean system. The current inability to numerically model the ice mélange motivates a new modeling approach proposed here. A continuum sea-ice model is taken as a starting point and icebergs are represented as thick and compact pieces of sea ice held together by large tensile and shear strength, selectively introduced into the sea-ice rheology. In order to modify the rheology correctly, an iceberg tracking procedure is implemented within a semi-Lagrangian time-stepping scheme, designed to exactly preserve iceberg shape through time. With the proposed treatment, sea ice and icebergs are considered a single fluid with spatially varying rheological properties. Mutual interactions are thus automatically included without the need for further parametrization. An important advantage of the presented framework for an ice mélange model is its potential to be easily included within sea-ice components of existing climate models.
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DEFF Research Database (Denmark)
Pries-Heje, Jan; Hovorka, Dirk S.
2013-01-01
development, and the subsequent secondary design that took place in a financial company. Analysis reveals an “iceberg phenomenon”; only a partial design justification was initially apparent, and underlying design assumptions are only revealed through deeper reflection and analysis. We conclude by providing...
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Physical approaches to iceberg severity prediction
National Research Council Canada - National Science Library
Marko, J. R; Fissel, D. B
1986-01-01
The large degree of interannual varibility in the number of icebergs present in the waters off Canada's southern East Coast presents difficulties for the exploration and production of offshore oil and gas...
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Zhang, Wendy
I will describe works from a collaboration between physics and glaciology that grew out of interactions at the Computations in Science seminar Leo Kadanoff organized at the University of Chicago. The first project considers the interaction between ocean waves and Antarctic ice shelves, large floating portions of ice formed by glacial outflows. Back-of-envelop calculation and seismic sensor data suggest that crevasses may be distributed within an ice shelf to shield it from wave energy. We also examine numerical scenarios in which changes in environmental forcing causes the ice shelf to fail catastrophically. The second project investigates the aftermath of iceberg calving off glacier terminus in Greenland using data recorded via time-lapse camera and terrestrial radar. Our observations indicate that the mélange of icebergs within the fjord experiences widespread jamming during a calving event and therefore is always close to being in a jammed state during periods of terminus quiescence. Joint work with Jason Amundson, Ivo R. Peters, Julian Freed Brown, Nicholas Guttenberg, Justin C Burton, L. Mac Cathles, Ryan Cassotto, Mark Fahnestock, Kristopher Darnell, Martin Truffer, Dorian S. Abbot and Douglas MacAyeal. Kadanoff Session DCMP.
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DEFF Research Database (Denmark)
Bjørst, Lill Rastad
2010-01-01
Abstract: The tip of the iceberg: Ice as a nonhuman actor of the climate change debate The global climate change debate has the Arctic as a core region of concern and ice has become a central aspect of discourses. This article discusses ice representations from six different contexts linked...
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Dinniman, Michael S.; Klinck, John M.; Smith, Walker O.
2007-11-01
Satellite imagery shows that there was substantial variability in the sea ice extent in the Ross Sea during 2001-2003. Much of this variability is thought to be due to several large icebergs that moved through the area during that period. The effects of these changes in sea ice on circulation and water mass distributions are investigated with a numerical general circulation model. It would be difficult to simulate the highly variable sea ice from 2001 to 2003 with a dynamic sea ice model since much of the variability was due to the floating icebergs. Here, sea ice concentration is specified from satellite observations. To examine the effects of changes in sea ice due to iceberg C-19, simulations were performed using either climatological ice concentrations or the observed ice for that period. The heat balance around the Ross Sea Polynya (RSP) shows that the dominant term in the surface heat budget is the net exchange with the atmosphere, but advection of oceanic warm water is also important. The area average annual basal melt rate beneath the Ross Ice Shelf is reduced by 12% in the observed sea ice simulation. The observed sea ice simulation also creates more High-Salinity Shelf Water. Another simulation was performed with observed sea ice and a fixed iceberg representing B-15A. There is reduced advection of warm surface water during summer from the RSP into McMurdo Sound due to B-15A, but a much stronger reduction is due to the late opening of the RSP in early 2003 because of C-19.
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Green icebergs formed by freezing of organic-rich seawater to the base of Antarctic ice shelves
Warren, Stephen G.; Roesler, Collin S.; Morgan, Vincent I.; Brandt, Richard E.; Goodwin, Ian D.; Allison, Ian
1993-01-01
Although most icebergs are blue, green icebergs are seen occasionally in the Antarctic ocean. Chemical and isotopic analysis of samples from green icebergs indicate that the ice consists of desalinated frozen seawater, as does the basal ice from the Amery Ice Shelf. Spectral reflectance of a green iceberg measured near 67°S, 62°E, confirms that the color is inherent to the ice, not an artifact of the illumination. Pure ice appears blue owing to its absorption of red photons. Addition of a constituent that absorbs blue photons can shift the peak reflectance from blue to green. Such a constituent was identified by spectrophotometric analysis of core samples from this iceberg and from the Amery basal ice, and of seawater samples from Prydz Bay off the Amery Ice Shelf. Analysis of the samples by fluorescence spectroscopy indicates that the blue absorption, and hence the inherent green color, is due to the presence of marine-derived organic matter in the green iceberg, basal ice, and seawater. Thick accumulations of green ice, in icebergs and at the base of ice shelves, indicate that high concentrations of organic matter exist in seawater for centuries at the depth of basal freezing.
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Ship-Iceberg Discrimination in Sentinel-2 Multispectral Imagery by Supervised Classification
Directory of Open Access Journals (Sweden)
Peder Heiselberg
2017-11-01
Full Text Available The European Space Agency Sentinel-2 satellites provide multispectral images with pixel sizes down to 10 m. This high resolution allows for fast and frequent detection, classification and discrimination of various objects in the sea, which is relevant in general and specifically for the vast Arctic environment. We analyze several sets of multispectral image data from Denmark and Greenland fall and winter, and describe a supervised search and classification algorithm based on physical parameters that successfully finds and classifies all objects in the sea with reflectance above a threshold. It discriminates between objects like ships, islands, wakes, and icebergs, ice floes, and clouds with accuracy better than 90%. Pan-sharpening the infrared bands leads to classification and discrimination of ice floes and clouds better than 95%. For complex images with abundant ice floes or clouds, however, the false alarm rate dominates for small non-sailing boats.
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Continental Island Formation and the Archaeology of Defaunation on Zanzibar, Eastern Africa.
Directory of Open Access Journals (Sweden)
Mary E Prendergast
Full Text Available With rising sea levels at the end of the Pleistocene, land-bridge or continental islands were formed around the world. Many of these islands have been extensively studied from a biogeographical perspective, particularly in terms of impacts of island creation on terrestrial vertebrates. However, a majority of studies rely on contemporary faunal distributions rather than fossil data. Here, we present archaeological findings from the island of Zanzibar (also known as Unguja off the eastern African coast, to provide a temporal perspective on island biogeography. The site of Kuumbi Cave, excavated by multiple teams since 2005, has revealed the longest cultural and faunal record for any eastern African island. This record extends to the Late Pleistocene, when Zanzibar was part of the mainland, and attests to the extirpation of large mainland mammals in the millennia after the island became separated. We draw on modeling and sedimentary data to examine the process by which Zanzibar was most recently separated from the mainland, providing the first systematic insights into the nature and chronology of this process. We subsequently investigate the cultural and faunal record from Kuumbi Cave, which provides at least five key temporal windows into human activities and faunal presence: two at the end of the Last Glacial Maximum (LGM, one during the period of post-LGM rapid sea level rise and island formation, and two in the late Holocene (Middle Iron Age and Late Iron Age. This record demonstrates the presence of large mammals during the period of island formation, and their severe reduction or disappearance in the Kuumbi Cave sequence by the late Holocene. While various limitations, including discontinuity in the sequence, problematize attempts to clearly attribute defaunation to anthropogenic or island biogeographic processes, Kuumbi Cave offers an unprecedented opportunity to examine post-Pleistocene island formation and its long-term consequences for
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Continental Island Formation and the Archaeology of Defaunation on Zanzibar, Eastern Africa
Prendergast, Mary E.; Rouby, Hélène; Punnwong, Paramita; Marchant, Robert; Crowther, Alison; Kourampas, Nikos; Shipton, Ceri; Walsh, Martin; Lambeck, Kurt; Boivin, Nicole L.
2016-01-01
With rising sea levels at the end of the Pleistocene, land-bridge or continental islands were formed around the world. Many of these islands have been extensively studied from a biogeographical perspective, particularly in terms of impacts of island creation on terrestrial vertebrates. However, a majority of studies rely on contemporary faunal distributions rather than fossil data. Here, we present archaeological findings from the island of Zanzibar (also known as Unguja) off the eastern African coast, to provide a temporal perspective on island biogeography. The site of Kuumbi Cave, excavated by multiple teams since 2005, has revealed the longest cultural and faunal record for any eastern African island. This record extends to the Late Pleistocene, when Zanzibar was part of the mainland, and attests to the extirpation of large mainland mammals in the millennia after the island became separated. We draw on modeling and sedimentary data to examine the process by which Zanzibar was most recently separated from the mainland, providing the first systematic insights into the nature and chronology of this process. We subsequently investigate the cultural and faunal record from Kuumbi Cave, which provides at least five key temporal windows into human activities and faunal presence: two at the end of the Last Glacial Maximum (LGM), one during the period of post-LGM rapid sea level rise and island formation, and two in the late Holocene (Middle Iron Age and Late Iron Age). This record demonstrates the presence of large mammals during the period of island formation, and their severe reduction or disappearance in the Kuumbi Cave sequence by the late Holocene. While various limitations, including discontinuity in the sequence, problematize attempts to clearly attribute defaunation to anthropogenic or island biogeographic processes, Kuumbi Cave offers an unprecedented opportunity to examine post-Pleistocene island formation and its long-term consequences for human and animal
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Continental Island Formation and the Archaeology of Defaunation on Zanzibar, Eastern Africa.
Prendergast, Mary E; Rouby, Hélène; Punnwong, Paramita; Marchant, Robert; Crowther, Alison; Kourampas, Nikos; Shipton, Ceri; Walsh, Martin; Lambeck, Kurt; Boivin, Nicole L
2016-01-01
With rising sea levels at the end of the Pleistocene, land-bridge or continental islands were formed around the world. Many of these islands have been extensively studied from a biogeographical perspective, particularly in terms of impacts of island creation on terrestrial vertebrates. However, a majority of studies rely on contemporary faunal distributions rather than fossil data. Here, we present archaeological findings from the island of Zanzibar (also known as Unguja) off the eastern African coast, to provide a temporal perspective on island biogeography. The site of Kuumbi Cave, excavated by multiple teams since 2005, has revealed the longest cultural and faunal record for any eastern African island. This record extends to the Late Pleistocene, when Zanzibar was part of the mainland, and attests to the extirpation of large mainland mammals in the millennia after the island became separated. We draw on modeling and sedimentary data to examine the process by which Zanzibar was most recently separated from the mainland, providing the first systematic insights into the nature and chronology of this process. We subsequently investigate the cultural and faunal record from Kuumbi Cave, which provides at least five key temporal windows into human activities and faunal presence: two at the end of the Last Glacial Maximum (LGM), one during the period of post-LGM rapid sea level rise and island formation, and two in the late Holocene (Middle Iron Age and Late Iron Age). This record demonstrates the presence of large mammals during the period of island formation, and their severe reduction or disappearance in the Kuumbi Cave sequence by the late Holocene. While various limitations, including discontinuity in the sequence, problematize attempts to clearly attribute defaunation to anthropogenic or island biogeographic processes, Kuumbi Cave offers an unprecedented opportunity to examine post-Pleistocene island formation and its long-term consequences for human and animal
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Beaufort Formation, eastern Axel Heiberg Island, Canadian Arctic Archipelago
Energy Technology Data Exchange (ETDEWEB)
Bustin, R.M.
1982-07-01
On eastern Axel Heiberg Island erosional outliers of the Miocene-early Pliocene Beaufort Formation overlie with angular unconformity, or are faulted against, Mesozoic and early Tertiary strata East of Princess Margaret Arch the Beaufort Formation is divisible into three lithofacies: a conglomerate lithofacies interpreted as alluvial-plain deposits, a sandstone conglomerate lithofacies interpreted as distal alluvial-fan deposits and a sandstone-mudstone-siltstone lithofacies interpreted as alluvial-plain deposits. The floodplain was vegetated by a coniferous forest which was characterized by Picea banksii, Larix, Metasequoia and Alnus. Paleocurrent analysis, facies relationships and petrology of the conglomerates and sandstones indicate the provenance of the Beaufort Formation wa Mesozoic strata to the west. Deposition of the Beaufort Formation on eastern Axel Heiberg Island clearly postdates folding of mid-Eocene and older strata and thus provides a minimum age for orogenesis in this part of the Arctic. The occurrence of faulted massiv conglomerates of the Beaufort Formation provides evidence for Miocene-early Pliocene or earlier uplift of ancestral Princess Margaret Arch and a still-later phase of extension.
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International Ice Patrol (IIP) Iceberg Sightings Database
National Oceanic and Atmospheric Administration, Department of Commerce — The International Ice Patrol (IIP) has been collecting information on iceberg activity in the North Atlantic since 1911. This database contains the data from these...
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Blonski, S.; Peterson, C. A.
2006-12-01
Observations of icebergs are identified as one of the requirements for the GEOSS (Global Earth Observation System of Systems) in the area of reducing loss of life and property from natural and human-induced disasters. However, iceberg observations are not included among targets in the GEOSS 10-Year Implementation Plan, and thus there is an unfulfilled need for iceberg detection and tracking in the near future. Large Antarctic icebergs have been tracked by the National Ice Center and by the academic community using a variety of satellite sensors including both passive and active microwave imagers, such as SSM/I (Special Sensor Microwave/Imager) deployed on the DMSP (Defense Meteorological Satellite Program) spacecraft. Improvements provided in recent years by NASA and non-NASA satellite radars, scatterometers, and radiometers resulted in an increased number of observed icebergs and even prompted a question: `Is The Number of Antarctic Icebergs Really Increasing?' [D.G. Long, J. Ballantyne, and C. Bertoia, Eos, AGU Transactions 83(42):469&474, 15 October 2002]. AMSR-E (Advanced Microwave Scanning Radiometer for the Earth Observing System) represents an improvement over SSM/I, its predecessor. AMSR-E has more measurement channels and higher spatial resolution than SSM/I. For example, the instantaneous field of view of the AMSR-E's 89-GHz channels is 6 km by 4 km versus 16 km by 14 km for SSM/I's comparable 85-GHz channels. AMSR-E, deployed on the Aqua satellite, scans across a 1450-km swath and provides brightness temperature measurements with near-global coverage every one or two days. In polar regions, overlapping swaths generate coverage up to multiple times per day and allow for creation of image time series with high temporal resolution. Despite these advantages, only incidental usage of AMSR-E data for iceberg tracking has been reported so far, none in an operational environment. Therefore, an experiment was undertaken in the RPC (Rapid Prototyping Capability
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Jawak, S. D.; Luis, A. J.
2017-12-01
Estimating mass loss of the Antarctic ice sheet caused by iceberg calving is a challenging job. Antarctica is surrounded by a variety of large, medium and small sized ice shelves, glacier tongues and coastal areas without offshore floating ice masses. It is possible to monitor surface structures on the continental ice and the ice shelves as well as calved icebergs using NASA-ISRO synthetic aperture radar (NISAR) satellite images in future. The NISAR, which is planned to be launched in 2020, can be used as an all-weather and all-season system to classify the coastline of Antarctica to map patterns of surface structures close to the calving front. Additionally, classifying patterns and density of surface structures distributed over the ice shelves and ice tongues can be a challenging research where NISAR can be of a great advantage. So this work explores use of NISAR to map surface structures visible on ice shelves which can provide advisories to field teams. The ice shelf fronts has been categorized into various classes based on surface structures relative to the calving front within a 30 km-wide seaward strip. The resulting map of the classified calving fronts around Antarctica and their description would provide a detailed representation of crevasse formation and dominant iceberg in the southern ocean which pose a threat to navigation of Antarctic bound ships.
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Experimental study and process parameters analysis on the vacuum cooling of iceberg lettuce
International Nuclear Information System (INIS)
He Suyan; Li Yunfei
2008-01-01
The vacuum cooling of iceberg lettuce was described in this paper. Based on the energy and mass balance, a mathematical model was developed to analyze the performance of the vacuum cooler and the evaporation-boiling phenomena during vacuum cooling of iceberg lettuce. The temporal trends of total system pressure, produce temperature such as surface temperature, center temperature, mass-average temperature, the weight loss of iceberg lettuce during vacuum cooling were predicted. Validation experimentation is achieved in the designed vacuum cooler. The experimental data were compared with the simulation results. It was found that the differences of the temperature between the simulation and the experiments were within 1 deg. C. The amount of water evaporated from the iceberg lettuce by simulation was 3.32% during the whole vacuum cooling, while the tested water loss rate was 2.97%, the maximal deviation of weight loss was within 0.59%. The simulation results agreed well with the experimental data
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Experimental study and process parameters analysis on the vacuum cooling of iceberg lettuce
Energy Technology Data Exchange (ETDEWEB)
He, Su-Yan [School of Mechanical and Electrical Engineering, Qingdao University, Qingdao 266071 (China); Li, Yun-Fei [Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University (China)
2008-10-15
The vacuum cooling of iceberg lettuce was described in this paper. Based on the energy and mass balance, a mathematical model was developed to analyze the performance of the vacuum cooler and the evaporation-boiling phenomena during vacuum cooling of iceberg lettuce. The temporal trends of total system pressure, produce temperature such as surface temperature, center temperature, mass-average temperature, the weight loss of iceberg lettuce during vacuum cooling were predicted. Validation experimentation is achieved in the designed vacuum cooler. The experimental data were compared with the simulation results. It was found that the differences of the temperature between the simulation and the experiments were within 1{sup o}C. The amount of water evaporated from the iceberg lettuce by simulation was 3.32% during the whole vacuum cooling, while the tested water loss rate was 2.97%, the maximal deviation of weight loss was within 0.59%. The simulation results agreed well with the experimental data. (author)
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Experimental study and process parameters analysis on the vacuum cooling of iceberg lettuce
Energy Technology Data Exchange (ETDEWEB)
He Suyan [School of Mechanical and Electrical Engineering, Qingdao University, Qingdao 266071 (China)], E-mail: hesuyan67829@sina.com; Li Yunfei [Department of Food Science and Engineering, School of Agriculture and Biology, Shanghai Jiao Tong University (China)
2008-10-15
The vacuum cooling of iceberg lettuce was described in this paper. Based on the energy and mass balance, a mathematical model was developed to analyze the performance of the vacuum cooler and the evaporation-boiling phenomena during vacuum cooling of iceberg lettuce. The temporal trends of total system pressure, produce temperature such as surface temperature, center temperature, mass-average temperature, the weight loss of iceberg lettuce during vacuum cooling were predicted. Validation experimentation is achieved in the designed vacuum cooler. The experimental data were compared with the simulation results. It was found that the differences of the temperature between the simulation and the experiments were within 1 deg. C. The amount of water evaporated from the iceberg lettuce by simulation was 3.32% during the whole vacuum cooling, while the tested water loss rate was 2.97%, the maximal deviation of weight loss was within 0.59%. The simulation results agreed well with the experimental data.
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Directory of Open Access Journals (Sweden)
Martínez de Velasco, Emilio F.
1982-06-01
Full Text Available In this article a personal is offered of the designer of the TVE tower in Madrid, reviewing all the aspects which have influenced the final aesthetic result, and the role of the architect within the team of tecnicians of different specialities, which in the words of the writer is like the point of an iceberg of great dimensions, but it is not for this that his invention is less important, since the design is in this case a determined problem, by the conditioning of the outline and above all technological, it is necessary to surmount this barrier so that the elements making up the complex, shaft, platform, decks arid mast form a satisfactory plastic unit.Se ofrece en este artículo una visión personal del proyectista de la torre de TVE, en Madrid, pasando revista a todos los aspectos que han incidido en el resultado estético final, y el papel del arquitecto dentro del equipo pluridisciplinar de técnicos de diferentes especialidades, que aparece en palabras del autor como la punta de un iceberg de grandes dimensiones, pero no por esto su intervención es menos importante, ya que si bien el diseño es en este caso un problema sobredeterminado; por los condicionantes del entorno y sobre todo tecnológicos, es preciso superar esta barrera para conseguir que los elementos que componen el conjunto, fuste, plataformas, cubiertas y mástil formen una unidad plástica satisfactoria.
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The role of cooperative iceberg capsize during ice-shelf disintegration
Wilder, W. G.; Burton, J. C.; Amundson, J. M.; Cathles, L. M.; Zhang, W. W.
2011-12-01
The physical processes responsible for the sudden, rapid collapse of Antarctic ice-shelves (Larsen B, in 2002; Wilkins, in 2008) are poorly understood. Observations are limited to a handful of satellite images. Thus we have undertaken a series of laboratory-scale experiments using a water-filled tank and "ice" made from buoyant plastic blocks to investigate these processes. Previous experiments have quantified how gravitational potential energy of single-iceberg capsize is converted to other forms of energy [described in Burton et al., submitted], including hydrodynamic forms that may feed back on the ice shelf to cause additional calving. The new experiments reported here examine the energetics of hydrodynamically coupled icebergs that exhibit collective behaviors qualitatively similar to features observed in satellite imagery. Our results suggest that there is a critical proximity at which icebergs will capsize in the same direction an overwhelming majority of the time (cooperative capsize), and a significant part of the gravitational potential energy is converted into translational kinetic energy. We speculate that the residual translational energy observed in our experiments may explain the significant expansion rate (~1 meter/second) of collapsing Antarctic ice-shelves. Burton, J. C., J. M. Amundson, D. S. Abbot, A. Boghosian, L. M. Cathles, S. Correa-Legisos, K. N. Darnell, N. Guttenberg, D. M. Holland, and D. R. MacAyeal. submitted. Laboratory investigations of iceberg-capsize dynamics, energy dissipation and tsunamigenesis. J. Geophys. Res.
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Bioavailable iron in the Southern Ocean: the significance of the iceberg conveyor belt.
Raiswell, Rob; Benning, Liane G; Tranter, Martyn; Tulaczyk, Slawek
2008-05-30
Productivity in the Southern Oceans is iron-limited, and the supply of iron dissolved from aeolian dust is believed to be the main source from outside the marine reservoir. Glacial sediment sources of iron have rarely been considered, as the iron has been assumed to be inert and non-bioavailable. This study demonstrates the presence of potentially bioavailable Fe as ferrihydrite and goethite in nanoparticulate clusters, in sediments collected from icebergs in the Southern Ocean and glaciers on the Antarctic landmass. Nanoparticles in ice can be transported by icebergs away from coastal regions in the Southern Ocean, enabling melting to release bioavailable Fe to the open ocean. The abundance of nanoparticulate iron has been measured by an ascorbate extraction. This data indicates that the fluxes of bioavailable iron supplied to the Southern Ocean from aeolian dust (0.01-0.13 Tg yr(-1)) and icebergs (0.06-0.12 Tg yr(-1)) are comparable. Increases in iceberg production thus have the capacity to increase productivity and this newly identified negative feedback may help to mitigate fossil fuel emissions.
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Association
2007-01-01
One hundred days into 2007 and with the new executive committee in place, we would like to present you with a report of the work carried out so far. First, the visible part: the subjects and actions regularly covered in Echo. Then, like an iceberg, we will review the hidden part, which is the most important in terms of effort and often the most fearsome because it is invisible, thus unpredictable.
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Influence of a minor periodicity on the magnetic island formation in tokamaks
International Nuclear Information System (INIS)
Matsuda, Shinzaburo
1975-01-01
A formation of magnetic islands due to external error fields in tokamaks is described. In particular, current control fields associated with shell gaps are shown to make islands of significant size. Moreover, we found that a toroidal minor periodicity of these perturbation fields, which is generally represented by the number of shell gaps, has an important meaning for the suppression of the resonant magnetic islands. (auth.)
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Energy Technology Data Exchange (ETDEWEB)
Lee, Gloria; Lo, Annie; Short, Sarah A.; Mankelow, Tosti J.; Spring, Frances; Parsons, Stephen F.; Mohandas, Narla; Anstee, David J.; Chasis, Joel Anne
2006-02-15
Erythroid progenitors differentiate in erythroblastic islands, bone marrow niches composed of erythroblasts surrounding a central macrophage. Evidence suggests that within islands adhesive interactions regulate erythropoiesis and apoptosis. We are exploring whether erythroid intercellular adhesion molecule-4 (ICAM-4), animmunoglobulin superfamily member, participates in island formation. Earlier, we identified alpha V integrins as ICAM-4 counter receptors. Since macrophages express alpha V, ICAM-4 potentially mediates island attachments. To test this, we generated ICAM-4 knockout mice and developed quantitative, live cell techniques for harvesting intact islands and for reforming islands in vitro. We observed a 47 percent decrease in islands reconstituted from ICAM-4 null marrow compared to wild type. We also found a striking decrease in islands formed in vivo in knockout mice. Further, peptides that block ICAM-4 alpha V adhesion produced a 53-57 percent decrease in reconstituted islands, strongly suggesting that ICAM-4 binding to macrophage alpha V functions in island integrity. Importantly, we documented that alpha V integrin is expressed in macrophages isolated from erythro blastic islands. Collectively, these data provide convincing evidence that ICAM-4 is critical in erythroblastic island formation via ICAM-4/alpha V adhesion and also demonstrate that the novel experimental strategies we developed will be valuable in exploring molecular mechanisms of erythroblastic island formation and their functional role in regulating erythropoiesis.
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Guillaso, Stephane; Gay, Michel; Gervaise, Cedric
2017-04-01
At the Zackenberg site, sea ice starts to move between June and September resulting in icebergs flowing freely on the sea. Splitting into smaller parts, they reduce in size. Icebergs represent a risk for maritime transport and needs to be studied. In order to determine iceberg density per surface unit, size distribution, and movement of icebergs, we need to observe, detect, range and track them. The use of SAR images is particularly well adapted in regions where cloud cover is very present. We focused our study on the Yung Sund fjord in Greenland, where lots of icebergs and sea ice are generated during the summer. In the beginning of July, sea ice breaks up first, followed by icebergs created by the different glaciers based in the ocean. During our investigation, we noticed that the iceberg and sea ice were drifting very fast and thus, we needed to adapt our methodology. To achieve our goal, we collected all remote sensing data available in the region, principally Sentinel 1/2 and LandSAT 8 during one ice free season (from July 1st 2016 to September 30th, 2016). We developed an original approach in order to detect, characterize and track icebergs and sea ice independently from data. The iceberg detection was made using a watershed technique. The advantage of this technique is that it can be applied to both optical and radar images. For the latter, calibrated intensity is transformed into an image using a scaling function, in order to make ice brighter. Land data is masked using a topographic map. When data is segmented, a statistical test derived from the CFAR approach is performed to isolate an iceberg and floating sea ice from the ocean. Finally, a method, such SIFT or BRISK is used to identify and track the different segmented object. These approaches give a representation of the object and make the tracking easier and independent of the scale and rotation, which can occur because icebergs are dependent on ocean currents and wind. Finally, to fill in the gap
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Effect of pressure on the vacuum cooling of iceberg lettuce
Energy Technology Data Exchange (ETDEWEB)
Ozturk, Hande Mutlu [Pamukkale University, Food Engineering Department, Faculty of Engineering, Denizli (Turkey); Ozturk, Harun Kemal [Pamukkale University, Mechanical Engineering Department, Faculty of Engineering, 20070 Kinikli, Denizli (Turkey)
2009-05-15
Vacuum cooling is known as a rapid evaporative cooling technique for any porous product which has free water. The aim of this paper is to apply vacuum cooling technique to the cooling of the iceberg lettuce and show the pressure effect on the cooling time and temperature decrease. The results of vacuum cooling are also compared with conventional cooling (cooling in refrigerator) for different temperatures. Vacuum cooling of iceberg lettuce at 0.7 kPa is about 13 times faster than conventional cooling of iceberg lettuce at 6 C. It has been also found that it is not possible to decrease the iceberg lettuce temperature below 10 C if vacuum cooling method is used and vacuum pressure is set to 1.5 kPa. (author) [French] Le refroidissement sous vide est connu comme une technique evaporative rapide refroidissant pour n'importe quel produit poreux qui a de l'eau libre. Le but de ce papier est d'appliquer le refroidissement sous vide pour le refroidissement de la laitue et examiner l'effet de la pression sur le temps de refroidissement et la diminution de temperature. Les resultats de refroidissement sous vide sont aussi compares avec le refroidissement conventionnel (refroidissement dans le refrigerateur) pour les differentes temperatures. Le refroidissement a vide de laitue a 0.7 kPa est environ 13 fois plus vite que le refroidissement conventionnel de laitue croquante a 6 C. Il a ete aussi constate qu'il n'est pas possible de diminuer la temperature de laitue ci-dessous 10 C si le refroidissement sous vide est utilise comme methode et la pression a vide est montree a 1.5 kPa. (orig.)
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Island formation without attractive interaction
Jansen, A.P.J.
2008-01-01
We show that adsorbates on surfaces can form islands even if there are no attractive interactions. Instead, strong repulsion between adsorbates at short distances can lead to islands, because such islands increase the entropy of the adsorbates that are not part of the islands. We suggest that this
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A possible mechanism for the seed island formation
International Nuclear Information System (INIS)
Pustovitov, V.D.
2005-01-01
The evolution of neoclassical tearing modes (NTMs) is usually described by the generalized Rutherford equation allowing the mode growth from a finite level, which is referred to as seed island. It is generally accepted that the seed island is induced by some MHD event, but sometimes the NTMs start without visible triggers. Here we discuss a possible role of the error fields in producing the seeds. The analysis is based on Maxwell equations and Ohm's law for magnetic perturbation outside the plasma. The plasma enters the problem via boundary conditions. Its contribution is described by the decay/growth rate and the toroidal rotation frequency of perturbation. The model also assumes a resonant harmonic in the spectrum of the error field. It is shown that the resonant field amplification near the stability boundary of the mode may be a mechanism resulting in the 'spontaneous' formation of the seed island. In contrast to NTM seeding due to the sawteeth, fishbones, or ELMs, the considered mechanism needs some longer time. However, all the estimates give realistic values consistent with typical experimental conditions. (author)
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Dinasquet, Julie; Richert, Inga; Logares, Ramiro; Yager, Patricia; Bertilsson, Stefan; Riemann, Lasse
2017-06-01
The number of icebergs produced from ice-shelf disintegration has increased over the past decade in Antarctica. These drifting icebergs mix the water column, influence stratification and nutrient condition, and can affect local productivity and food web composition. Data on whether icebergs affect bacterioplankton function and composition are scarce, however. We assessed the influence of iceberg drift on bacterial community composition and on their ability to exploit carbon substrates during summer in the coastal Southern Ocean. An elevated bacterial production and a different community composition were observed in iceberg-influenced waters relative to the undisturbed water column nearby. These major differences were confirmed in short-term incubations with bromodeoxyuridine followed by CARD-FISH. Furthermore, one-week bottle incubations amended with inorganic nutrients and carbon substrates (a mix of substrates, glutamine, N-acetylglucosamine, or pyruvate) revealed contrasting capacity of bacterioplankton to utilize specific carbon substrates in the iceberg-influenced waters compared with the undisturbed site. Our study demonstrates that the hydrographical perturbations introduced by a drifting iceberg can affect activity, composition, and substrate utilization capability of marine bacterioplankton. Consequently, in a context of global warming, increased frequency of drifting icebergs in polar regions holds the potential to affect carbon and nutrient biogeochemistry at local and possibly regional scales. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.
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Directory of Open Access Journals (Sweden)
Hyunchul Kang
2015-03-01
Full Text Available We investigate the in-network processing of an iceberg join query in wireless sensor networks (WSNs. An iceberg join is a special type of join where only those joined tuples whose cardinality exceeds a certain threshold (called iceberg threshold are qualified for the result. Processing such a join involves the value matching for the join predicate as well as the checking of the cardinality constraint for the iceberg threshold. In the previous scheme, the value matching is carried out as the main task for filtering non-joinable tuples while the iceberg threshold is treated as an additional constraint. We take an alternative approach, meeting the cardinality constraint first and matching values next. In this approach, with a logical fragmentation of the join operand relations on the aggregate counts of the joining attribute values, the optimal sequence of 2-way fragment semijoins is generated, where each fragment semijoin employs a Bloom filter as a synopsis of the joining attribute values. This sequence filters non-joinable tuples in an energy-efficient way in WSNs. Through implementation and a set of detailed experiments, we show that our alternative approach considerably outperforms the previous one.
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Kang, Hyunchul
2015-01-01
We investigate the in-network processing of an iceberg join query in wireless sensor networks (WSNs). An iceberg join is a special type of join where only those joined tuples whose cardinality exceeds a certain threshold (called iceberg threshold) are qualified for the result. Processing such a join involves the value matching for the join predicate as well as the checking of the cardinality constraint for the iceberg threshold. In the previous scheme, the value matching is carried out as the main task for filtering non-joinable tuples while the iceberg threshold is treated as an additional constraint. We take an alternative approach, meeting the cardinality constraint first and matching values next. In this approach, with a logical fragmentation of the join operand relations on the aggregate counts of the joining attribute values, the optimal sequence of 2-way fragment semijoins is generated, where each fragment semijoin employs a Bloom filter as a synopsis of the joining attribute values. This sequence filters non-joinable tuples in an energy-efficient way in WSNs. Through implementation and a set of detailed experiments, we show that our alternative approach considerably outperforms the previous one. PMID:25774710
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Quantification and Analysis of Icebergs in a Tidewater Glacier Fjord Using an Object-Based Approach.
Directory of Open Access Journals (Sweden)
Robert W McNabb
Full Text Available Tidewater glaciers are glaciers that terminate in, and calve icebergs into, the ocean. In addition to the influence that tidewater glaciers have on physical and chemical oceanography, floating icebergs serve as habitat for marine animals such as harbor seals (Phoca vitulina richardii. The availability and spatial distribution of glacier ice in the fjords is likely a key environmental variable that influences the abundance and distribution of selected marine mammals; however, the amount of ice and the fine-scale characteristics of ice in fjords have not been systematically quantified. Given the predicted changes in glacier habitat, there is a need for the development of methods that could be broadly applied to quantify changes in available ice habitat in tidewater glacier fjords. We present a case study to describe a novel method that uses object-based image analysis (OBIA to classify floating glacier ice in a tidewater glacier fjord from high-resolution aerial digital imagery. Our objectives were to (i develop workflows and rule sets to classify high spatial resolution airborne imagery of floating glacier ice; (ii quantify the amount and fine-scale characteristics of floating glacier ice; (iii and develop processes for automating the object-based analysis of floating glacier ice for large number of images from a representative survey day during June 2007 in Johns Hopkins Inlet (JHI, a tidewater glacier fjord in Glacier Bay National Park, southeastern Alaska. On 18 June 2007, JHI was comprised of brash ice ([Formula: see text] = 45.2%, SD = 41.5%, water ([Formula: see text] = 52.7%, SD = 42.3%, and icebergs ([Formula: see text] = 2.1%, SD = 1.4%. Average iceberg size per scene was 5.7 m2 (SD = 2.6 m2. We estimate the total area (± uncertainty of iceberg habitat in the fjord to be 455,400 ± 123,000 m2. The method works well for classifying icebergs across scenes (classification accuracy of 75.6%; the largest classification errors occur in areas
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A Simple Laboratory Scale Model of Iceberg Dynamics and its Role in Undergraduate Education
Burton, J. C.; MacAyeal, D. R.; Nakamura, N.
2011-12-01
Lab-scale models of geophysical phenomena have a long history in research and education. For example, at the University of Chicago, Dave Fultz developed laboratory-scale models of atmospheric flows. The results from his laboratory were so stimulating that similar laboratories were subsequently established at a number of other institutions. Today, the Dave Fultz Memorial Laboratory for Hydrodynamics (http://geosci.uchicago.edu/~nnn/LAB/) teaches general circulation of the atmosphere and oceans to hundreds of students each year. Following this tradition, we have constructed a lab model of iceberg-capsize dynamics for use in the Fultz Laboratory, which focuses on the interface between glaciology and physical oceanography. The experiment consists of a 2.5 meter long wave tank containing water and plastic "icebergs". The motion of the icebergs is tracked using digital video. Movies can be found at: http://geosci.uchicago.edu/research/glaciology_files/tsunamigenesis_research.shtml. We have had 3 successful undergraduate interns with backgrounds in mathematics, engineering, and geosciences perform experiments, analyze data, and interpret results. In addition to iceberg dynamics, the wave-tank has served as a teaching tool in undergraduate classes studying dam-breaking and tsunami run-up. Motivated by the relatively inexpensive cost of our apparatus (~1K-2K dollars) and positive experiences of undergraduate students, we hope to serve as a model for undergraduate research and education that other universities may follow.
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Kumar, Ashish; Dasgupta, Dwaipayan; Maroudas, Dimitrios
We report a systematic study of complex pattern formation resulting from the driven dynamics of single-layer homoepitaxial islands on face-centered cubic (FCC) crystalline conducting substrate surfaces under the action of an externally applied electric field. The analysis is based on an experimentally validated nonlinear model of mass transport via island edge atomic diffusion, which also accounts for edge diffusional anisotropy. We analyze the morphological stability and simulate the field-driven evolution of rounded islands for an electric field oriented along the fast diffusion direction. For larger than critical island sizes on {110} and {100} FCC substrates, we show that multiple necking instabilities generate complex island patterns, including void-containing islands, mediated by sequences of breakup and coalescence events and distributed symmetrically with respect to the electric field direction. We analyze the dependence of the formed patterns on the original island size and on the duration of application of the external field. Starting from a single large rounded island, we characterize the evolution of the number of daughter islands and their average size and uniformity. The analysis reveals that the pattern formation kinetics follows a universal scaling relation. Division of Materials Sciences & Engineering, Office of Basic Energy Sciences, U.S. Department of Energy (Award No.: DE-FG02-07ER46407).
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Liu, Yong-Biao
2004-06-01
A field study was conducted to determine the distribution and development of aphid Nasonovia ribisnigri (Mosley) (Homoptera: Aphididae) populations in iceberg lettuce, Lactuca sativa L. 'Salinas'. Lettuce plants were transplanted and caged individually in the field and inoculated with apterous N. ribisnigri at 0, 1, 2, 3, and 4 wk after transplanting in spring and fall 2002. Plants were harvested 15-50 d after inoculations; numbers of alates and apterous N. ribisnigri were counted or estimated on each leaf for each plant. Inoculations during all 5 wk of plant development resulted in successful colonization of lettuce heads. Results indicated that head formation did not reduce the risk of colonization by N. ribisnigri to iceberg lettuce; plants were susceptible to colonization by N. ribisnigri throughout their development. For later inoculations, N. ribisnigri populations were relatively smaller, and aphids were found mostly within the heads. For earlier inoculations, N. ribisnigri populations were larger, and within-plant distributions shifted toward frame leaves. The shift of population distributions toward frame leaves correlated significantly with increases in N. ribisnigri population density. For most inoculations, more aphids were present on wrapper leaves than on other leaves. The proportion of alates did not vary significantly with population density. Population development of N ribisnigri also correlated significantly with heat unit accumulation. Yellow sticky cards were used to monitor alates in each cage. Catches of N. ribisnigri alates on yellow sticky cards were significantly correlated with total numbers of alates as well as with total population sizes on individual lettuce plants.
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Capture Zone Distributions and Island Morphologies in Organic Epitaxy and Graphene Formation
Pimpinelli, Alberto; Einstein, T. L.
2013-03-01
Stating that island nucleation is an essential step in the formation of an epitaxial or supported layer may appear trivially obvious. However, less trivial is the observation that the size of the critical nucleus plays a crucial role in that it determines both the island density (and therefore the size of domains) and the evolution of the island morphology. In this talk we will describe recent developments in the analysis of capture zone distributions (CZD) specifically tailored for application to organic materials. We will also describe specific features of organic and graphene island morphologies, and discuss how they are related to the nucleation process and to the size of the critical nucleus. Work at UMD supported by NSF-MRSEC, Grant DMR 05-20471 and NSF CHE 07-49949
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Bigg, G R; Wei, H L; Wilton, D J; Zhao, Y; Billings, S A; Hanna, E; Kadirkamanathan, V
2014-06-08
Iceberg calving is a major component of the total mass balance of the Greenland ice sheet (GrIS). A century-long record of Greenland icebergs comes from the International Ice Patrol's record of icebergs (I48N) passing latitude 48° N, off Newfoundland. I48N exhibits strong interannual variability, with a significant increase in amplitude over recent decades. In this study, we show, through a combination of nonlinear system identification and coupled ocean-iceberg modelling, that I48N's variability is predominantly caused by fluctuation in GrIS calving discharge rather than open ocean iceberg melting. We also demonstrate that the episodic variation in iceberg discharge is strongly linked to a nonlinear combination of recent changes in the surface mass balance (SMB) of the GrIS and regional atmospheric and oceanic climate variability, on the scale of the previous 1-3 years, with the dominant causal mechanism shifting between glaciological (SMB) and climatic (ocean temperature) over time. We suggest that this is a change in whether glacial run-off or under-ice melting is dominant, respectively. We also suggest that GrIS calving discharge is episodic on at least a regional scale and has recently been increasing significantly, largely as a result of west Greenland sources.
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Buchs, David M.; Williams, Rebecca; Sano, Shin-ichi; Wright, V. Paul
2018-05-01
Guyots are large seamounts with a flat summit that is generally believed to form due to constructional biogenic and/or erosional processes during the formation of volcanic islands. However, despite their large abundance in the oceans, there are still very few direct constraints on the nature and formation of guyots, in particular those formed at high latitude that lack a thick cap of shallow-marine carbonate rocks. It is largely accepted based on geophysical constraints and surficial observations/sampling that the summit platform of these guyots is shaped by wave abrasion during post-volcanic subsidence of volcanic islands. Here we provide novel constraints on this hypothesis and the summit geology of guyots with a lithostratigraphic analysis of cores from three Louisville seamounts (South Pacific) collected during Expedition 330 of the Integrated Ocean Drilling Program (IODP). Thirteen lithofacies of sedimentary and volcanic deposits are described, which include facies not previously recognized on the top of guyots, and offer a new insight into the formation of high-latitude oceanic islands on a fast-moving plate. Our results reveal that the lithostratigraphy of Louisville seamounts preserves a very consistent record of the formation and drowning of volcanic islands, with from bottom to top: (i) volcaniclastic sequences with abundant lava-fed delta deposits, (ii) submarine to subaerial shield lava flows, (iii) post-volcanic shallow to deeper marine sedimentary rocks lacking thick reef deposits, (iv) post-erosional rejuvenated volcanic rocks, and (v) pelagic sediments. Recognition of erosional boundaries between subaerial lava flows and shallow-marine sedimentary rocks provides novel support for post-volcanic wave planation of guyots. However, the summit geology of Louisville seamounts is dissimilar to that of high-latitude Hawaiian-Emperor guyots that have emplaced in a similar tectonic and environmental setting and that include thicker lava stacks with apparently
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Dynamics of seed magnetic island formation due to geometrically coupled perturbations
International Nuclear Information System (INIS)
Hegna, C.C.; Callen, J.D.; LaHaye, R.J.
1998-06-01
Seed magnetic island formation due to a dynamically growing external source in toroidal confinement devices is modeled as an initial value forced reconnection problem. For an external source whose amplitude grows on a time scale quickly compared to the Sweet-Parker time of resistive magnetohydrodynamics, the induced reconnection is characterized by a current sheet and a reconnected flux amplitude which lags in time the source amplitude. This suggests that neoclassical tearing modes, whose excitation requires a seed magnetic island, are more difficult to cause in high Lundquist number plasmas
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Picard, K.; Watson, S. J.; Fox, J. M.; Post, A.; Whittaker, J. M.; Lucieer, V.; Carey, R.; Coffin, M. F.; Hodgson, D.; Hogan, K.; Graham, A. G. C.
2017-12-01
Unravelling the glacial history of Sub-Antarctic islands can provide clues to past climate and Antarctic ice sheet stability. The glacial history of many sub-Antarctic islands is poorly understood, including the Heard and McDonald Islands (HIMI) located on the Kerguelen Plateau in the southern Indian Ocean. The geomorphologic development of HIMI has involved a combination of construction via hotspot volcanism and mechanical erosion caused by waves, weather, and glaciers. Today, the 2.5 km2 McDonald Islands are not glacierised; in contrast, the 368 km2 Heard Island has 12 major glaciers, some extending from the summit of 2813 m to sea level. Historical accounts from Heard Island suggest that the glaciers were more extensive in the 1850s to 1870s, and have retreated at least 12% (33.89 km2) since 1997. However, surrounding bathymetry suggests a much more extensive previous glaciation of the HIMI region that encompassed 9,585 km2, likely dating back at least to the Last Glacial Maximum (LGM) ca. 26.5 -19 ka. We present analyses of multibeam bathymetry and backscatter data, acquired aboard RV Investigator in early 2016, that support the previous existence of an extensive icecap. These data reveal widespread ice-marginal and subglacial features including moraines, over-deepened troughs, drumlins and crag-and-tails. Glacial landforms suggest paleo-ice flow directions and a glacial extent that are consistent with previously documented broad scale morphological features. We identify >660 iceberg keel scours in water depths ranging from 150 - 530 m. The orientations of the iceberg keel scours reflect the predominantly east-flowing Antarctic Circumpolar Current and westerly winds in the region. 40Ar/39Ar dating of volcanic rocks from submarine volcanoes around McDonald Islands suggests that volcanism and glaciation coincided. The flat-topped morphology of these volcanoes may result from lava-ice interaction or erosion by glaciers post eruption during a time of extensive ice
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Fertility Island Formation and Evolution in Dryland Ecosystems
Directory of Open Access Journals (Sweden)
Luca Ridolfi
2008-06-01
Full Text Available Vast dryland regions around the world are affected by the encroachment of woody vegetation, with important environmental and economical implications. Grassland-to-shrubland conversions are often triggered by disturbance of grassland vegetation, and the consequent formation of barren areas prone to erosion-induced nutrient losses. Inhibition of encroachment by erosion-induced depletion of soil nutrients contributes to the emergence of highly heterogeneous landscapes with shrub-dominated fertility islands surrounded by nutrient-poor bare soil. Here, we develop a process-based simplistic model thataccounts for the two competing processes of resource depletion and shrub encroachment by a non-linear diffusion mechanism. The proposed model is able to generate stable vegetation patterns with the same statistical properties as those observed in areas with well-developed fertility islands. We also show how a subsequent disturbance of shrubland vegetation can shift the dynamics toward states with smaller vegetation biomass. The process of land degradation may then occur through a number of irreversible intermediate transitions associated with losses in ecosystem function.
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Modelling the Dynamics of Iceberg-Soil Interaction during Seabed Gouging
Hoving, J.S.; Marquart, R.; Pisano, F.
2017-01-01
Not only in the Arctic, but also well outside the Arctic, icebergs can be a danger to buried offshore pipelines due to seabed gouging. As it is not economically feasible to bury these pipelines at depths where soil deformations are small, these pipelines are buried at sub-gouge depths where the soil
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Estimating flexural rigidity and load magnitude required for formation of Ross Island flexure moat
Jha, S.; Harry, D. L.; Wenman, C. P.
2017-12-01
Lithospheric flexural subsidence around Ross Island in West Antarctica led to formation of the Ross Island flexure moat. This subsidence was caused by two major volcanic phases on Ross Island. The first phase saw the first surficial expression of Ross Island and volcanism at Mt. Bird to the north of Ross Island, which lasted from 5.2 - 2.9 Ma. The second phase lasted from 1.78 Ma to present and is comprised of eruptions from Mt. Terror to the east, Mt. Erebus to the west and Hut Point Peninsula (HPP) to the south of Ross Island. Flexural subsidence of the lithosphere due to volcanism on Ross Island led to formation of a sedimentary moat around the island, which is preserved in stratigraphy imaged on seismic reflection profiles. We identified 5 unconformities (from deepest upward Ri, RMU1, RMU2, RMU3, RMU4) in the seismic surveys which correspond to flexural subsidence episodes around Ross Island since early Pliocene. Ri (4.4 Ma) lies near the bottom of the flexural moat and RMU4 near the seafloor and top of the moat fill. These unconformities were used to make isopach maps to constrain flexure modeling of the area. Isopach maps show circular or semi-circular flexure basins around Ross Island which is approximated using a continuous plate, point load flexure model. We used Ri - sea floor isopach to constrain flexure models for 5 profiles centered on 4 volcanic centers and trending radially out of Ross Island. Flexure models along two profiles beginning on Mt. Bird and one profile off HPP show a flexural rigidity range of 1.47 - 6.44 x 1018 Nm with load center of mass on Mt. Bird and on HPP, respectively. A similar model along a profile initiating on Mt. Terror, passing through Mt Erebus and extending west of Ross Island across the moat, yielded a higher flexural rigidity estimate of 2.03 x 1019 Nm with load centered at Mt. Erebus. A flexure model to the north east of Ross Island along a profile beginning at Mt Terror and trending north, provide the highest flexural
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Detailed forest formation mapping in the land cover map series for the Caribbean islands
Helmer, E. H.; Schill, S.; Pedreros, D. H.; Tieszen, L. L.; Kennaway, T.; Cushing, M.; Ruzycki, T.
2006-12-01
Forest formation and land cover maps for several Caribbean islands were developed from Landsat ETM+ imagery as part of a multi-organizational project. The spatially explicit data on forest formation types will permit more refined estimates of some forest attributes. The woody vegetation classification scheme relates closely to that of Areces-Malea et al. (1), who classify Caribbean vegetation according to standards of the US Federal Geographic Data Committee (FGDC, 1997), with modifications similar to those in Helmer et al. (2). For several of the islands, we developed image mosaics that filled cloudy parts of scenes with data from other scene dates after using regression tree normalization (3). The regression tree procedure permitted us to develop mosaics for wet and drought seasons for a few of the islands. The resulting multiseason imagery facilitated separation between classes such as seasonal evergreen forest, semi-deciduous forest (including semi-evergreen forest), and drought deciduous forest or woodland formations. We used decision tree classification methods to classify the Landsat image mosaics to detailed forest formations and land cover for Puerto Rico (4), St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines and Grenada. The decision trees classified a stack of raster layers for each mapping area that included the Landsat image bands and various ancillary raster data layers. For Puerto Rico, for example, the ancillary data included climate parameters (5). For some islands, the ancillary data included topographic derivatives such as aspect, slope and slope position, SRTM (6) or other topographic data. Mapping forest formations with decision tree classifiers, ancillary geospatial data, and cloud-free image mosaics, accurately distinguished spectrally similar forest formations, without the aid of ecological zone maps, on the islands where the approach was used. The approach resulted in maps of forest formations with comparable or better detail
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Liu, Yong-Biao
2005-12-01
The aphid Nasonovia ribisnigri (Mosley) is a common pest of lettuce in the United States. It hinders export of U.S. lettuce to the overseas market such as Japan where it is a quarantined pest. Ultralow oxygen treatments were studied for control of the insect on iceberg lettuce. Small-scale ultralow oxygen treatments in plastic jars were conducted at 1, 5, and 10 degrees C for different durations to determine effective treatment against nymphs and alates of N. ribisnigri. At oxygen levels of 0.015-0.025%, N. ribisnigri can be controlled in 3 d at 1 degrees C, 2 d at 5 degrees C, and 1 d at 10 degrees C. Large-scale ultralow oxygen treatments were conducted in bulk container treatment chambers with commercial iceberg lettuce heads for 2 d at 6 degrees C with oxygen levels of 0.015 and 0.025% and for 3 d at 3 degrees C with oxygen level of 0.015%. All treatments achieved complete control of N. ribisnigri. No negative impact on lettuce quality was detected after 2 wk of posttreatment storage. Therefore, the selected treatments have potential to be commercially developed for postharvest control of N. ribisnigri on iceberg lettuce.
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MHD flow layer formation at boundaries of magnetic islands in tokamak plasmas
International Nuclear Information System (INIS)
Jiaqi Dong; Yongxing Long; Zongze Mou; Jinhua Zhang
2005-01-01
Non-linear development of double tearing modes induced by electron viscosity is numerically simulated. MHD flow layers are demonstrated to merge in the development of the modes. The sheared flows are shown to lie just at the boundaries of the magnetic islands, and to have sufficient levels required for internal transport barrier (ITB) formation. Possible correlation between the layer formation and triggering of experimentally observed ITBs, preferentially formed in proximities of rational flux surfaces of low safety factors, is discussed. (author)
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International Nuclear Information System (INIS)
Boozer, A.H.
1983-08-01
The response of a finite conductivity plasma to resonant magnetic perturbations is studied. The equations, which are derived for the time development of magnetic islands, help one interpret the singular currents which occur under the assumption of perfect plasma conductivity. The relation to the Rutherford regime of resistive instabilities is given
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Acinetobacter lactucae sp. nov., isolated from iceberg lettuce (Asteraceae: Lactuca sativa)
Strain NRRL B-41902 and three closely related strains were isolated from iceberg lettuce. The strain was found to consist of strictly aerobic, gram-negative rods that formed cocci in late stationary phase. Subsequent to sequencing the 16S ribosomal RNA gene, it was found that strain NRRL B-41902 was...
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Digital Repository Service at National Institute of Oceanography (India)
Gupta, S.M.; Srinivasan, M.S.
Late Miocene radiolarian zones are encountered from mudstone strata of Sawai Bay Formation, Neill Island, Andamans. Percentage data of forty-five coarser taxonomic groups of radiolarians were subjected to Q-mode cluster analysis. Based...
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A prospective evaluation of occult disorders in obstructed defecation using the 'iceberg diagram'.
Pescatori, M; Spyrou, M; Pulvirenti d'Urso, A
2007-06-01
Surgical treatment of constipation and obstructed defecation (OD) carries frequent recurrences, as OD is an 'iceberg syndrome' characterized by 'underwater rocks' or occult diseases which may affect the outcome of surgery. The aim of this study was to evaluate occult disorders, in order to alert the clinician of these and minimize failures. One hundred consecutive constipated patients with OD symptoms, 81 women, median age 52 years, underwent perineal examination, proctoscopy, anorectal manometry and anal/vaginal ultrasound (US). Anorectal physiology and imaging tests were also carried out when indicated, as well as psychological and urogynaecological consultations. Symptoms were graded using a modified 1-20 constipation score. Both evident (e.g. rectocele) and occult (e.g. anismus) diseases were prospectively evaluated using a novel 'iceberg diagram'. The type of treatment, whether conservative or surgical, was also recorded. Fifty-four (54%) patients had both mucosal prolapse and rectocele. All patients had at least two occult OD-related diseases, 66 patients had at least three of them: anxiety-depression, anismus and rectal hyposensation were the most frequent (66%, 44% and 33%, respectively). The median constipation score was 11 (range 2-20), the median number of 'occult disorders' was 5 (range 2-8). Conservative treatment was carried out in most cases. Surgery was carried out in 14 (14%) patients. The novel 'iceberg diagram' allowed the adequate evaluation of OD-related occult diseases and better selection of patients for treatment. Most were managed conservatively, and only a minority were treated by surgery.
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Magnetic island formation in tokamaks
International Nuclear Information System (INIS)
Yoshikawa, S.
1989-04-01
The size of a magnetic island created by a perturbing helical field in a tokamak is estimated. A helical equilibrium of a current- carrying plasma is found in a helical coordinate and the helically flowing current in the cylinder that borders the plasma is calculated. From that solution, it is concluded that the helical perturbation of /approximately/10/sup /minus/4/ of the total plasma current is sufficient to cause an island width of approximately 5% of the plasma radius. 6 refs
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1992-01-01
This easterly looking view shows the seven major volcanic islands of the Canary Island chain (28.0N, 16.5W) and offers a unique view of the islands that have become a frequent vacation spot for Europeans. The northwest coastline of Africa, (Morocco and Western Sahara), is visible in the background. Frequently, these islands create an impact on local weather (cloud formations) and ocean currents (island wakes) as seen in this photo.
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DEFF Research Database (Denmark)
Carlsson, Monica Susanne
2018-01-01
This paper offers reflections on change agency formation in the Renewable Energy Island (REI) project on Samsø, following a field visit to the island in June 2016. Both individual and collective agency are set out as central for the processes leading to the change in the REI project, spurring ref...
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Kumar, Ashish; Dasgupta, Dwaipayan; Maroudas, Dimitrios
2017-07-01
We report a systematic study of complex pattern formation resulting from the driven dynamics of single-layer homoepitaxial islands on surfaces of face-centered-cubic (fcc) crystalline conducting substrates under the action of an externally applied electric field. The analysis is based on an experimentally validated nonlinear model of mass transport via island edge atomic diffusion, which also accounts for edge diffusional anisotropy. We analyze the morphological stability and simulate the field-driven evolution of rounded islands for an electric field oriented along the fast edge diffusion direction. For larger-than-critical island sizes on {110 } and {100 } fcc substrates, we show that multiple necking instabilities generate complex island patterns, including not-simply-connected void-containing islands mediated by sequences of breakup and coalescence events and distributed symmetrically with respect to the electric field direction. We analyze the dependence of the formed patterns on the original island size and on the duration of application of the external field. Starting from a single large rounded island, we characterize the evolution of the number of daughter islands and their average size and uniformity. The evolution of the average island size follows a universal power-law scaling relation, and the evolution of the total edge length of the islands in the complex pattern follows Kolmogorov-Johnson-Mehl-Avrami kinetics. Our study makes a strong case for the use of electric fields, as precisely controlled macroscopic forcing, toward surface patterning involving complex nanoscale features.
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Directory of Open Access Journals (Sweden)
Daniela Bencardino
2018-04-01
Full Text Available The aim of this study was to assess the microbiological quality of ready-to-eat (RTE iceberg lettuce. Our investigation was based on the consumption tendency of university students considered a target market for this product. A total of 78 RTE samples were collected from chain supermarkets and analysed for the enumeration of aerobic mesophilic count (AMC, Escherichia coli and the detection of Salmonella spp. and Listeria monocytogenes. All samples were negative for the presence of pathogens. The mean value of AMC at the beginning, in the middle and after the expiration date was: 6.88, 8.51 and 8.72 log CFU g-1, respectively. The same investigation was performed on 12 samples of fresh iceberg lettuce samples. No pathogens were found and the mean value of AMC was lower than the RTE category (5.73 log CFU g-1; P<0.05. The effectiveness of 5 washing methods was determined on 15 samples of both fresh and RTE iceberg lettuce. Samples were washed for 15’ and 30’ in tap water (500 mL, tap water with NaCl (4 g/500 mL, tap water with bicarbonate (8 g/500 mL, tap water with vinegar (10 mL/500 mL and tap water with chlorine-based disinfectant (10 mL/500 mL. A significant bacterial load reduction was recorded for vinegar and disinfectant after 30’ and 15’, respectively. Overall, these results showed that RTE iceberg lettuce is more contaminated than the fresh product. Also, the consumption in the first few days of packaging and after washing with disinfectants reduces the risk for health consumers.
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Review of "Lock, Stock, and Icebergs: A History of Canada's Arctic Maritime Sovereignty"
DEFF Research Database (Denmark)
Burke, Danita Catherine
2018-01-01
Adam Lajeunesse’s new book, "Lock, Stock, and Icebergs: A History of Canada’s Arctic Maritime Sovereignty" provides an interesting and detailed account of the history of Canada’s approach toward establishing sovereignty over the waters of the Arctic region. The book primarily focuses on Canada...
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Carbon distribution during plasma detachment triggered by edge magnetic island formation in LHD
International Nuclear Information System (INIS)
Dong, C.F.; Morita, S.; Kobayashi, M.; Oishi, T.; Goto, M.; Wang, E.H.; Huang, X.L.
2013-01-01
The detached plasma has been successfully achieved by applying the edge 1/1 magnetic island in Large Helical Device (LHD). Carbon, which is uniquely the dominant intrinsic impurity in general LHD discharges, is considered to be the main radiating species in the island-triggered detached plasma. The vertical profile of CIV measured from general discharges of LHD is characterized by a single edge intensity peak. In detached plasmas triggered by the edge magnetic island formation, however, the vertical profile of CIV shows a significant difference. Double edge peaks of CIV are found during the plasma detachment and the CIV radiation is also remarkably enhanced in the vicinity of X-point, whereas the vertical profile of CVI does not show any significant difference in both the attached and detached plasmas. In this proceeding the carbon distribution during the plasma detachment is presented and the results are discussed with edge magnetic field structure. (author)
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Directory of Open Access Journals (Sweden)
Gesham Magombedze
Full Text Available Johne's disease (JD is a chronic, enteric disease in ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP. Disease progression follows four distinct stages: silent, subclinical, clinical and advanced. Available diagnostic tests have poor sensitivity and cannot detect early stages of the infection; as a result, only animals in the clinical and advanced stages, which represent the tip of the 'iceberg', are identified through testing. The Iceberg Phenomenon is then applied to provide estimates for JD prevalence. For one animal in the advanced stage, it is assumed that there are one to two in the clinical stage, four to eight in the subclinical stage, and ten to fourteen in the silent stage. These ratios, however, are based on little evidence. To evaluate the ratios, we developed a deterministic ordinary differential equation model of JD transmission and disease progression dynamics. When duration periods associated with the natural course of the disease progression are used, the above ratios do not hold. The ratios used to estimate JD prevalence need to be further investigated.
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Energy Technology Data Exchange (ETDEWEB)
Condron, Alan [Univ. of Massachusetts, Amherst, MA (United States)
2016-10-18
In the present-day North Atlantic Ocean, relatively warm and salty water moves northwards from the tropics to the high latitudes, sinks, and returns southward towards the equator as North Atlantic Deep Water, forming the so called Atlantic Meridional Overturning Circulation (AMOC). It has been found that the stability of the AMOC is non-linearly related to the freshwater budget of the North Atlantic. In this way, additional fresh water can be added to the ocean with little impact, until a tipping point is reached that causes the AMOC to suddenly weaken and the Northern Hemisphere to abruptly cool. A great deal of uncertainty still remains over the sensitivity of the AMOC to changes in freshwater discharge as a result of the unrealistic manner in which freshwater has historically been added to climate models. Frequently, freshwater is discharged in ocean models entirely as liquid water, but in reality a large fraction of freshwater entering the ocean is ice calving from marine glaciers (half for Antarctica and two-thirds for Greenland). To more accurately quantify AMOC sensitivity to past and future changes in freshwater input, this project developed a comprehensive iceberg model to more realistically simulate the interaction between the cryosphere and the oceans at high-latitudes. The iceberg model created is written in Fortran90 and designed to scale efficiently on High Performance Computing (HPC) clusters so that tens-of-thousands of icebergs can be simulated at any time. Experiments performed with our model showed that in the Pleistocene there would have been enormous floods of freshwater released into the North Atlantic that would have transported icebergs and meltwater along the entire east coast of the United States, as far south as Florida Keys. In addition, high-resolution, modern-day, model simulations showed that if the Greenland Ice Sheet continues to melt at its current rate then there will be a 6-fold increase in the number of icebergs drifting in the
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Kienholz, C.; Amundson, J. M.; Jackson, R. H.; Motyka, R. J.; Nash, J. D.; Sutherland, D.
2017-12-01
Tidewater glacier behavior is driven by poorly understood processes occurring at the ice-ocean interface, including sedimentation and erosion, iceberg calving, and submarine melting. These processes are inherently difficult to observe, calling for innovative field techniques and numerical models. As part of a multi-year field effort to constrain ocean-glacier heat and mass exchange, we deployed an array of high-rate time-lapse cameras (sampling intervals between 15 seconds and 2 minutes) to monitor the terminus of LeConte Glacier and its proglacial fjord. The camera array has operated continuously for more than a year. Our high sampling rates enable tracking of iceberg motion with optical flow algorithms, which have been used widely in computer vision but less so in glaciology and oceanography. Such algorithms track individual features (e.g., corners of icebergs), which is ideal for iceberg-rich fjords, where motion can vary substantially over short temporal and spatial scales (e.g., due to complex surface currents or different iceberg sizes). We process our data to quantify subdaily to seasonal patterns in surface currents and relate them to forcing from tides, wind, and glacier runoff. Flow is most variable close to the glacier terminus due to frequent calving events and turbulent plume dynamics. Farther down fjord, more consistent patterns emerge, driven by tides, wind, and runoff and altered by fjord geometry. Our tracking results compare favorably to and complement our Acoustic Doppler Current Profiler measurements from boats and moorings. Given their high spatial and temporal resolution, our observations will place important surface constraints on forthcoming hydrodynamic modeling efforts. The deployment of the cameras in a harsh environment and the corresponding image processing provided an opportunity to test hardware and software thoroughly, which will prove useful for similar systems at other glaciers.
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Directory of Open Access Journals (Sweden)
Natasha Bhutani
2015-01-01
Full Text Available Antibiotic resistance in bacteria is a global problem exacerbated by the dissemination of resistant bacteria via uncooked food, such as green leafy vegetables. New strains of bacteria are emerging on a daily basis with novel expanded antibiotic resistance profiles. In this pilot study, we examined the occurrence of antibiotic resistant bacteria against five classes of antibiotics on iceberg lettuce retailed in local convenience stores in Rochester, Michigan. In this study, 138 morphologically distinct bacterial colonies from 9 iceberg lettuce samples were randomly picked and tested for antibiotic resistance. Among these isolates, the vast majority (86% demonstrated resistance to cefotaxime, and among the resistant bacteria, the majority showed multiple drug resistance, particularly against cefotaxime, chloramphenicol, and tetracycline. Three bacterial isolates (2.17% out of 138 were extended spectrum beta-lactamase (ESBL producers. Two ESBL producers (T1 and T5 were identified as Klebsiella pneumoniae, an opportunistic pathogen with transferable sulfhydryl variable- (SHV- and TEM-type ESBLs, respectively. The DNA sequence analysis of the blaSHV detected in K. pneumoniae isolate T1 revealed 99% relatedness to blaSHV genes found in clinical isolates. This implies that iceberg lettuce is a potential reservoir of newly emerging and evolving antibiotic resistant bacteria and its consumption poses serious threat to human health.
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Release of three iceberg lettuce populations that combined resistance to two soil borne diseases
The Agricultural Research Service, United States Department of Agriculture and the University of California, Davis, announce the release of three F2:4 breeding populations of iceberg lettuce (Lactuca sativa L.). The breeding populations combine the cor and Verticillium resistance 1 (Vr1) loci to co...
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Mitchell-Bruker, S.; Childers, D.; Ross, M.; Leonard, L.; Solo-Gabriel, H.; Stothoff, S.
2002-05-01
Tree islands are a prominent feature in the Everglades ridge and slough wetlands. These tree islands are believed to be a remnant of the historical pre-drainage flow system. Within Everglades National Park, hardwood hammock and bayhead tree islands commonly form as teardrop-shaped mounds, rising above the sawgrass marsh. These tree islands are usually oriented along the direction of surface water flow, with the highest elevation and widest part of the island at the upstream head. The island narrows as it descends into the marsh at the downstream end, terminating in a tail that sometimes includes a zone of dead or dying sawgrass. The shape and orientation of the tree islands suggests that surface water flow has been instrumental in their formation, however occasional flow measurements indicate that the slow moving water of the Everglades does not provide sufficient energy to transport even moderate amounts of suspended sediment. This low flow velocity, coupled with the extremely low turbidity of the Everglades water suggests that if sediment transport and deposition processes are instrumental in forming tree islands, the process is probably occurring over short distances and long time intervals. It is also possible that concentration and transport of nutrients is an important element in tree island formation. Because the Everglades marsh is a low nutrient environment, processes that create areas of increased phosphorous concentration result in changes in the vegetation. Because many hardwood hammock and bayhead tree islands have heads that are situated on bedrock highs, the higher and drier elevation of the head allows for trees to grow. These trees could concentrate phosphorous either by acting as wildlife attractors, or by acting as \\x8Dphosphorous pumpsŒ, transporting groundwater with high concentrations of phosphorous through the roots to the tree. We are characterizing vegetation, litter fall, sediments, surface water flow, hydrologic gradients and nutrient
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Hydrologic measurements and implications for tree island formation within Everglades National Park
Bazante, Jose; Jacobi, Gary; Solo-Gabriele, Helena M.; Reed, David; Mitchell-Bruker, Sherry; Childers, Daniel L.; Leonard, Lynn; Ross, Michael
2006-10-01
study sites and were primarily of organic origin. The mean particle size of the suspended sediments was 3 μm with a distribution that was exponential. Critical velocities needed to cause re-suspension of these particles were estimated to be above the actual velocities observed. Sediment transport within the water column appears to be at a near steady state during the conditions evaluated with low rates of sediment loss balanced by presumably the release of equivalent quantities of particles of organic origin. Existing hydrologic conditions do not appear to transport sufficient suspended sediments to result in the formation of tree islands. Of interest would be to collect hydrologic and sediment transport data during extreme hydrologic events to determine if enough sediment is transported under these conditions to promote sufficient sediment accumulations.
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International Nuclear Information System (INIS)
Ngadenin
2016-01-01
Geological, radiometrical, and geochemical studies of Banggai granites and Bobong Formation have been conducted in order to obtain potential uranium area. Taliabu Island is selected for the study because Taliabu Island is a micro continent fraction of the Gondwana super continent that separated at the end of the Mesozoic to Paleogene period. Some types of uranium mineralization formed in the period of Gondwana include sandstone-type, lignite coal type, and vein-type. Taliabu Island is a small part from the Gondwana super continent so it is expected will be found uranium mineralization or at least indications of uranium mineralization occurrences. The aim of this study is to obtain uranium potential areas for the development of uranium exploration in the future. The methods used are reviewing geological, radiometric, and geochemical data from various sources. The results of review showed that geological setting, radiometric, and geochemical data gives positive indication to the formation of uranium mineralization for sandstone type. Banggai granite is a potential uranium source. Sandstone of Bobong Formation as a potential host rock. Coal and pyrite as a potential precipitant. Uranium potential area is located on Bobong Formation and its surrounding. (author)
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Submarine geology and geomorphology of active Sub-Antarctic volcanoes: Heard and McDonald Islands
Watson, S. J.; Coffin, M. F.; Whittaker, J. M.; Lucieer, V.; Fox, J. M.; Carey, R.; Arculus, R. J.; Bowie, A. R.; Chase, Z.; Robertson, R.; Martin, T.; Cooke, F.
2016-12-01
Heard and McDonald Islands (HIMI) are World Heritage listed sub-Antarctic active volcanic islands in the Southern Indian Ocean. Built atop the Kerguelen Plateau by Neogene-Quaternary volcanism, HIMI represent subaerial exposures of the second largest submarine Large Igneous Province globally. Onshore, processes influencing island evolution include glaciers, weathering, volcanism, vertical tectonics and mass-wasting (Duncan et al. 2016). Waters surrounding HIMI are largely uncharted, due to their remote location. Hence, the extent to which these same processes shape the submarine environment around HIMI has not been investigated. In early 2016, we conducted marine geophysical and geologic surveys around HIMI aboard RV Investigator (IN2016_V01). Results show that volcanic and sedimentary features prominently trend east-west, likely a result of erosion by the eastward flowing Antarctic Circumpolar Current and tidal currents. However, spatial patterns of submarine volcanism and sediment distribution differ substantially between the islands. >70 sea knolls surround McDonald Island suggesting substantial submarine volcanism. Geophysical data reveals hard volcanic seafloor around McDonald Island, whereas Heard Island is characterised by sedimentary sequences tens of meters or more thick and iceberg scours - indicative of glacial processes. Differences in submarine geomorphology are likely due to the active glaciation of Heard Island and differing rock types (Heard: alkali basalt, McDonald: phonolite), and dominant products (clastics vs. lava). Variations may also reflect different magmatic plumbing systems beneath the two active volcanoes (Heard produces larger volumes of more focused lava, whilst McDonald extrudes smaller volumes of more evolved lavas from multiple vents across the edifice). Using geophysical data, corroborated with new and existing geologic data, we present the first geomorphic map revealing the processes that shape the submarine environment around HIMI.
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Being as an iceberg: hypertensive treatment adherence experiences in southeast of Iran
Directory of Open Access Journals (Sweden)
Nahid Dehghan Nayeri
2015-09-01
Full Text Available Background: Treatment adherence is often an important issue in the management of hypertension. Deep understanding of adherence behavior as well as its influential factors can expand knowledge about treatment adherence among hypertensives. Objective: The aim of this study was to explore patients, their families, and healthcare providers’ experiences about hypertension treatment adherence in southeast of Iran. Design: A qualitative study was conducted to explore the experience of patients, family members, and healthcare providers (n=18 by using a conventional content analysis. The purposive sampling method was used. Data were collected through semi-structured and deep interviews. Results: Data analysis showed that hypertensive treatment adherence in an Iranian context is like an iceberg with two subthemes. The first subtheme relates to the upper and clear part of this iceberg and it consists of two categories, including 1 healthy and 2 unhealthy regimens. The second subtheme associates with under-water and unanticipated part and it consists of four categories, including 1 the nature of disease and treatment, 2 the individual resources, 3 the healthcare organization, and 4 the socio-cultural environment. Conclusions: The treatment adherence features emerged in this study can be useful in designing and developing context-based hypertension interventions. Further qualitative and quantitative studies with a closer collaboration between the social, natural, and medical sciences in other Iranian populations are needed to confirm the findings.
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Spatial characterization of the meltwater field from icebergs in the Weddell Sea.
Helly, John J; Kaufmann, Ronald S; Vernet, Maria; Stephenson, Gordon R
2011-04-05
We describe the results from a spatial cyberinfrastructure developed to characterize the meltwater field around individual icebergs and integrate the results with regional- and global-scale data. During the course of the cyberinfrastructure development, it became clear that we were also building an integrated sampling planning capability across multidisciplinary teams that provided greater agility in allocating expedition resources resulting in new scientific insights. The cyberinfrastructure-enabled method is a complement to the conventional methods of hydrographic sampling in which the ship provides a static platform on a station-by-station basis. We adapted a sea-floor mapping method to more rapidly characterize the sea surface geophysically and biologically. By jointly analyzing the multisource, continuously sampled biological, chemical, and physical parameters, using Global Positioning System time as the data fusion key, this surface-mapping method enables us to examine the relationship between the meltwater field of the iceberg to the larger-scale marine ecosystem of the Southern Ocean. Through geospatial data fusion, we are able to combine very fine-scale maps of dynamic processes with more synoptic but lower-resolution data from satellite systems. Our results illustrate the importance of spatial cyberinfrastructure in the overall scientific enterprise and identify key interfaces and sources of error that require improved controls for the development of future Earth observing systems as we move into an era of peta- and exascale, data-intensive computing.
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Paillart, M.J.M.; Vossen, J.M.B.M.; Levin, E.; Lommen, E.; Otma, E.C.; Snels, J.C.M.A.; Woltering, E.J.
2017-01-01
The end of shelf life of fresh-cut iceberg lettuce packed in modified atmosphere (MA) is determined by its visual quality and by its microbial load. The total microbial load should not exceed 6–7 log CFU g−1 mesophilic counting and be free of human pathogens. Not much is known about specific
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Laboratory experiments inform iceberg-calving forces
Cathles, L. M.; Burton, J. C.
2013-12-01
Globally detected glacial earthquakes are produced during cubic-kilometer scale calving events. The mechanism producing these earthquakes and the dependence of the seismic moment on iceberg size and glacial calving front geometry are not well established. We use a laboratory-scale model of the post-fracture calving process to measure aspects of the calving process not observable in nature. In our experiments, buoyant plastic blocks rest against against a force plate (glacial terminus) which measures both the total force and the torque exerted during the calving process. The blocks are gravitationally unstable, so that they will spontaneously capsize and rotate away from the terminus. We find that hydrodynamics are crucial when considering the coupling between the calving process and the solid earth. There is both a pushing contact force and a simultaneous pulling hydrodynamic force created by a reduced pressure along the terminus face. This suggests that a single couple force mechanism is a more appropriate mode for glacial earthquakes than the commonly used centroid single force model.
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Formation and healing of n = 1 magnetic islands in LHD equilibrium
International Nuclear Information System (INIS)
Kanno, Ryutaro; Hayashi, Takaya; Okamoto, Masao
2005-01-01
Magnetic islands with the toroidal mode number n = 1, e.g. m/n = 1/1 and 2/1 islands, in a Large Helical Device (LHD) equilibrium are studied using the three-dimensional MHD equilibrium code, HINT. In order to accomplish this purpose, the HINT code has been improved. The equilibrium analysis, in particular an analysis of the LHD equilibrium with an m/n = 1/1 island, is required for the local island divertor experiment, in order to understand the magnetic structures of field lines, i.e. flux surfaces, islands and ergodic field lines. We find that the m/n = 2/1 island can be healed for a finite equilibrium beta, while the m/n = 1/1 island is not healed and is surrounded with ergodic field lines for finite-β. From the latter result, we can conjecture that the island divertor concept is effective even for finite equilibrium beta-values, but the performance of the island divertor is deteriorated for finite-β because of the existence of the ergodic zone between the closed surfaces (i.e. the core region) and the m/n = 1/1 island. We also find that the width of the m/n = 1/1 island depends on the equilibrium beta value and that the island located at the inside of the torus has the advantage of retaining its width
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Surfacing the Iceberg of Leadership: A New Taxonomy of Leadership Concepts and Theories
Kaufman, EK; Cletzer, DA
2017-01-01
Leadership scholars have long sought to impose order on the numerous theories in leadership literature. While mid-level theories abound, no taxonomy exists to provide hierarchy and a mechanism for explaining how theories interrelate. This poster offers a new taxonomy for organizing leadership theories and concepts based on the metaphor of an iceberg. It invites leadership scholars to vet their own leadership courses and undergraduate leadership programs to determine the depth to which they ex...
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International Nuclear Information System (INIS)
Nakamura, Yodai; Asahara, Yoshihiro; Ozawa, Tomowo; Kameo, Koji
1999-01-01
The Neogene Shimajiri Group is distributed sporadically in the Ryukyu islands. This study focuses on the Shimajiri Group in Kumejima Island, central Ryukyu, and clarifies its stratigraphy and geologic age on the basis of 1) lithostratigraphy, 2) calcareous nannofossil biostratigraphy, and 3) strontium isotope stratigraphy. The Shimajiri Group in Kumejima Island unconformably overlies the middle Miocene Aradake Formation, and is overlain by the Pleistocene Ryukyu Group. The group is divided into three formations, namely the Maja, the Aka and the Uegusukudake Formations in ascending order, and the first two are redefined in this paper based on the new geologic evidence. The Maja Formation consists mainly of fine-grained sandstone, sandy siltstone and alternating beds of them. The Aka Formation is mainly composed of cross-stratified sandstone, pumiceous sandstone and tuffaceous siltstone, and unconformably overlies the Maja Formation. The Uegusukudake Formation, conformably overlying the Aka Formation, consists of basaltic lava, tuff breccia and andesite. On the basis of calcareous nannofossil biostratigraphy, the Maja and Aka Formations can be assigned to Zone CN9 and Zone CN12b of Okada and Bukry (1980) respectively. Strontium isotope ages of the molluscan fossil specimens obtained from the Maja and Aka Formations revealed that the Maja Formation is assigned to the late Miocene (ca. 7.8-7.2 Ma) and the Aka Formation is assigned to the late Pliocene (ca. 3.2-3.1 Ma). These ages are concordant with the nannofossil biostratigraphy. The upper Miocene Maja Formation yields many molluscan fossils in which the characteristic species of the Kakegawa Fauna, such as Amussiopecten praesignis and Mimachlamys satoi are contained. The molluscan fauna of the Maja Formation is significant in understanding the origin of the Kakegawa Fauna, as the characteristic species of the Plio-Pleistocene Kakegawa Fauna already appeared in the Ryukyu Islands in the late Miocene. (author)
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Iceberg killing fields limit huge potential for benthic blue carbon in Antarctic shallows.
Barnes, David K A
2017-07-01
Climate-forced ice losses are increasing potential for iceberg-seabed collisions, termed ice scour. At Ryder Bay, West Antarctic Peninsula (WAP) sea ice, oceanography, phytoplankton and encrusting zoobenthos have been monitored since 1998. In 2003, grids of seabed markers, covering 225 m 2 , were established, surveyed and replaced annually to measure ice scour frequency. Disturbance history has been recorded for each m 2 of seabed monitored at 5-25 m for ~13 years. Encrusting fauna, collected from impacted and nonimpacted metres each year, show coincident benthos responses in growth, mortality and mass of benthic immobilized carbon. Encrusting benthic growth was mainly determined by microalgal bloom duration; each day, nanophytoplankton exceeded 200 μg L -1 produced ~0.05 mm radial growth of bryozoans, and sea temperature >0 °C added 0.002 mm day -1 . Mortality and persistence of growth, as benthic carbon immobilization, were mainly influenced by ice scour. Nearly 30% of monitored seabed was hit each year, and just 7% of shallows were not hit. Hits in deeper water were more deadly, but less frequent, so mortality decreased with depth. Five-year recovery time doubled benthic carbon stocks. Scour-driven mortality varied annually, with two-thirds of all monitored fauna killed in a single year (2009). Reduced fast ice after 2006 ramped iceberg scouring, killing half the encrusting benthos each year in following years. Ice scour coupled with low phytoplankton biomass drove a phase shift to high mortality and depressed zoobenthic immobilized carbon stocks, which has persevered for 10 years since. Stocks of immobilized benthic carbon averaged nearly 15 g m -2 . WAP ice scouring may be recycling 80 000 tonnes of carbon yr -1 . Without scouring, such carbon would remain immobilized and the 2.3% of shelf which are shallows could be as productive as all the remaining continental shelf. The region's future, when glaciers reach grounding lines and iceberg
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The Agricultural Research Service, U.S. Department of Agriculture announces the release of sixteen breeding lines of lettuce (Lactuca sativa L.). Five (SM13-Il, SM13-I2, SM13-I3, SM13-I4, and SM13-I5) of the six iceberg breeding lines can be used for whole head or salad blend production; the sixth i...
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Quality of fresh-cut Iceberg lettuce and spinach irradiated at doses up to 4 kGy
International Nuclear Information System (INIS)
Fan Xuetong; Guan Wenqiang; Sokorai, Kimberly J.B.
2012-01-01
Fresh-cut Iceberg lettuce packaged in modified atmosphere packages and spinach in perforated film bags were irradiated with gamma rays at doses of 0, 1, 2, 3, and 4 kGy. After irradiation, the samples were stored for 14 days at 4 °C. O 2 levels in the packages of fresh-cut Iceberg lettuce decreased and CO 2 levels increased with increasing radiation dose, suggesting that irradiation increased respiration rates of lettuce. Tissue browning of irradiated cut lettuce was less severe than that of non-irradiated, probably due to the lower O 2 levels in the packages. However, samples irradiated at 3 and 4 kGy had lower maximum force and more severe sogginess than the non-irradiated control. In addition, ascorbic acid content of irradiated lettuce was 22–40% lower than the non-irradiated samples after 14 days of storage. The visual appearance of spinach was not affected by irradiation even at a dose of 4 kGy. Consumer acceptance suggested that more people would dislike and would not buy spinach that was treated at 3 and 4 kGy as compared to the non-irradiated sample. Overall, irradiation at doses of 1 and 2 kGy may be employed to enhance microbial safety of fresh-cut Iceberg lettuce and spinach while maintaining quality. - Highlights: ▶ Headspace composition in the modified atmosphere packages of cut lettuce was affected by irradiation. ▶ Fresh-cut lettuce in adapted atmosphere could tolerate 1 or 2 kGy rays without quality deterioration in look and texture. ▶ Lettuce irradiated at doses higher than 2 kGy developed sogginess. ▶ Irradiated spinach maintained a good appearance at doses of 3 and 4 kGy. ▶ Higher doses (3 and 4 kGy) of radiation decreased consumers' likingness and purchase intent of irradiated spinach.
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Refining the model of barrier island formation along a paraglacial coast in the Gulf of Maine
Hein, Christopher J.; FitzGerald, Duncan M.; Carruthers, Emily A.; Stone, Byron D.; Barnhardt, Walter A.; Gontz, Allen M.
2012-01-01
Details of the internal architecture and local geochronology of Plum Island, the longest barrier in the Gulf of Maine, have refined our understanding of barrier island formation in paraglacial settings. Ground-penetrating radar and shallow-seismic profiles coupled with sediment cores and radiocarbon dates provide an 8000-year evolutionary history of this barrier system in response to changes in sediment sources and supply rates as well as variability in the rate of sea-level change. The barrier sequence overlies tills of Wisconsinan and Illinoian glaciations as well as late Pleistocene glaciomarine clay deposited during the post-glacial sea-level highstand at approximately 17 ka. Holocene sediment began accumulating at the site of Plum Island at 7–8 ka, in the form of coarse fluvial channel-lag deposits related to the 50-m wide erosional channel of the Parker River that carved into underlying glaciomarine deposits during a lower stand of sea level. Plum Island had first developed in its modern location by ca. 3.6 ka through onshore migration and vertical accretion of reworked regressive and lowstand deposits. The prevalence of southerly, seaward-dipping layers indicates that greater than 60% of the barrier lithosome developed in its modern location through southerly spit progradation, consistent with a dominantly longshore transport system driven by northeast storms. Thinner sequences of northerly, landward-dipping clinoforms represent the northern recurve of the prograding spit. A 5–6-m-thick inlet-fill sequence was identified overlying the lower stand fluvial deposit; its stratigraphy captures events of channel migration, ebb-delta breaching, onshore bar migration, channel shoaling and inlet infilling associated with the migration and eventual closure of the inlet. This inlet had a maximum cross-sectional area of 2800 m2 and was active around 3.5–3.6 ka. Discovery of this inlet suggests that the tidal prism was once larger than at present. Bay infilling
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O JORNALISMO CULTURAL E A LÓGICA DO ICEBERG
Directory of Open Access Journals (Sweden)
Leonardo Cunha
2008-06-01
Full Text Available O artigo aborda uma lacuna do Jornalismo Cultural brasileiro, que é a marginalização da cobertura sobre os processos culturais - particularmente a economia da cultura e a política cultural. Tal lacuna se deve ao enfoque excessivo nas pautas factuais e de agenda – centradas, sobretudo, nas obras em lançamento e nos próprios artistas. Os autores argumentam que tal opção editorial revela uma lógica do iceberg, ou seja, o olhar direcionado quase exclusivamente para aquilo que está em evidência na área das artes e do entretenimento. Para sugerir uma alternativa, o artigo se aprofunda na economia da cultura, revelando sua complexidade e sugerindo formas de como o jornalismo cultural poderia pautar esse campo.
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The study was conducted to investigate the effect of modified atmosphere packaging (MAP) and delay of irradiation application on the quality of cut Iceberg lettuce. Overall visual quality and tissue browning of cut lettuce were evaluated using a scale of 9-1 while texture was analyzed instrumentally...
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Ruiz-Fernández, Jesús; Oliva, Marc; García-Hernández, Cristina
2017-06-01
This article focuses on the spatial distribution of vegetation formations in Elephant Point, an ice-free area of 1.16km 2 located in Livingston Island (South Shetland Islands, Antarctica). Fieldwork carried out in January 2014 consisted of floristic surveys and designation of a vegetation map. We have examined these data in a GIS environment together with topographical and geomorphological features existing in the peninsula in order to infer the factors controlling vegetation distribution. This has allowed quantifying the total area covered by the four different vegetation formations distributed across the peninsula, proliferating mainly on bedrock plateaus and Holocene raised beaches. Grass formation is essentially composed of Deschampsia antarctica, distributed almost exclusively on raised beaches, and covering 4.1% of the ice-free surface. The remaining three formations are fundamentally composed of cryptogam species. The first of which is fruticose lichen and moss formation, present on high bedrock plateaus and principally formed by lichens such as Usnea aurantiaco-atra. The next is the crustose lichen formation, spreading on bedrock plateaus near the coast populated by bird colonies. In this case, ornitocoprophilous lichens such as Caloplaca regalis, Xanthoria elegans and Haematomma erythromma are predominant. Together, both formations have colonised 5.1% of the peninsula. The last variety, moss carpet and moss cushion formation, occupies 1.4% of the deglaciated surface, spreading primarily in flooded areas, stabilised talus slopes, and bedrock plateaus as well. Therefore, the total surface colonised by vegetation is 12.2ha, which comprises 10.5% of the peninsula. Due to the retreat of the Rotch Dome glacier, 20.1ha remain ice-free since 1956 (17.3% of the deglaciated area). Ever since, even though the Antarctic Peninsula has registered one of the most significant temperature rises on Earth, vegetation has only colonised 0.04ha of this new space, which merely
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Holocene Evolution and Sediment Provenance of Horn Island, Mississippi, USA
Schulze, N.; Wallace, D. J.; Miner, M. D.
2017-12-01
As one of the most stable islands in the Mississippi-Alabama barrier island chain, Horn Island provides critical habitat, plays an important role in regulating estuarine conditions in the Mississippi Sound, and helps to attenuate wave energy and storm surge for the mainland. The provenance of sediments comprising Horn Island is largely unknown and has implications for mode of island genesis and evolution. The existing literature proposes that island chain formation was initiated by bar emergence from a subaqueous spit that grew laterally westward from Dauphin Island in the east. Decelerating sea level rise 4,000 to 5,000 years ago facilitated island formation. This proposed mode of formation is supported by a lone radiocarbon date from lagoonal sediments below Horn Island, suggesting the system formed after 4,615 ± 215 years BP. Rivers supplying suspended sediment include the Mississippi, Pascagoula, Mobile and Apalachicola, but the variable nature of their paths and sediment supply means that Horn Island has received differing amounts of sediment from these proximal rivers throughout the Holocene. To analyze the stratigraphy and sediment characteristics of Horn Island, we will utilize 24 vibracores (up to 6 meters in length) from offshore Horn Island that were obtained by the United States Geological Survey (USGS) and 9 onshore drill cores (up to 28 meters in length) from the Mississippi Department of Environmental Quality. High-resolution LiDAR data collected by the National Oceanic and Atmospheric Administration in 2010 will be used to describe modern geomorphic barrier environments. We will employ down-core x-ray diffraction and x-ray fluorescence analyses to identify mineralogical and chemical signatures that potentially correspond to unique signatures of the fluvial sources of proximal rivers. New radiocarbon ages will be used to constrain the timing of island formation and alterations in sediment supply. High-resolution shallow geophysical data will provide
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National Research Council Canada - National Science Library
Detwiler, Cristy; Hackworth, Carla; Holcomb, Kali; Boquet, Albert; Pfleiderer, Elaine; Wiegmann, Douglas; Shappell, Scott
2006-01-01
.... Recently however, the Federal Aviation Administration and other governmental and civilian organizations have focused their attention on one piece of this proverbial "iceberg," that being GA accidents...
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Cescon, Anna Lisa; Cooper, J. Andrew G.; Jackson, Derek W. T.
2014-05-01
In a changing climate context coastal areas will be affected by more frequent extreme events. Understanding the relationship between extreme events and coastal geomorphic response is critical to future adaptation plans. Beach ridge landforms commonly identified as hurricane deposits along tropical coasts in Australia and in the Caribbean Sea. However their formative processes in such environments are still not well understood. In particular, the role of different extreme wave events (storm waves, tsunami waves and extreme swell), in generating beach ridges is critical to their use as palaeotempestology archives. Anegada Island is a carbonate platform situated in the British Virgin Island between the Atlantic Ocean and the Caribbean Sea. Pleistocene in age, Anegada is surrounded by the Horseshoe fringing coral reef. Two Holocene sandy beach ridge plains are present on the western part of the island. The north beach ridge plain is Atlantic facing and has at least 30 ridges; the south beach ridge plain is Caribbean Sea facing and contains 10 ridges. Historical aerial photos enabled the shoreline evolution from 1953 to 2012 to be studied. Three different coastal domains are associate with the beach ridge plains: strong east-west longshore transport affects the north coastline, the south-west coastline from West End to Pomato Point represents an export corridor for these sediments and finally, along the southern coastline, from Pomato Point to Settling Point the area presents a depositional zone with little to no change in the last 70 years. The link between the extreme wave events that have affected Anegada Island in the last 70 years and beach ridge creation is discussed. Hurricane Donna crossed over Anegada Island in 1960: its geomorphological signature is tracked in the shoreline change analysis and its implication in beach ridge formation is discussed. Anegada Island has also been impacted by tsunami waves (Atwater et al., 2012) and a comparative discussion of the
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Late Quaternary climate change shapes island biodiversity
DEFF Research Database (Denmark)
Weigelt, Patrick; Steinbauer, Manuel; Cabral, Juliano
2016-01-01
Island biogeographical models consider islands either as geologically static with biodiversity resulting from ecologically neutral immigration–extinction dynamics1, or as geologically dynamic with biodiversity resulting from immigration–speciation–extinction dynamics influenced by changes in island...... sea levels3, 4 and caused massive changes in island area, isolation and connectivity5, orders of magnitude faster than the geological processes of island formation, subsidence and erosion considered in island theory2, 6. Consequences of these oscillations for present biodiversity remain unassessed5, 7...
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Wael M. Semida; P. Hadley; W. Sobeih; N. A. El-Sawah; M. A. S. Barakat
2013-01-01
Photoselective plastic films with thermic properties are now available so that greenhouses clad with such plastics exhibit a higher degree of “Greenhouse Effect” with a consequent increase in night time temperature. In this study, we investigate the potential benefits of a range of thermic plastic films used as greenhouse cover materials on the vegetative and reproductive growth and development of Iceberg lettuce (Lactuca sativa L). Transplants were grown under thermic fi...
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (40 m cell size) bathymetry of the shelf and slope environments of Howland Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the shelf and slope environments of Jarvis Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (40 m cell size) bathymetry of the shelf and slope environments of Baker Island, Pacific Remote Island Areas, Central Pacific. Almost complete bottom...
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DEFF Research Database (Denmark)
Simonsen, Dorthe Gert
2017-01-01
In this article, I explore the formation of airspace in Britain from 1910 to 1913. The technology of flight challenged the “flat discourse” of nationalized geography, drawing up instead a volumetric space in the sky as airplanes flew from the Continent to England. The drive to control aerial...... extension of the Island Kingdom, extrapolating its coastal borders into the sky. However, even as Parliament passed the Aerial Navigation Act in 1913, this legal construction of an island in the air could not endure the agency of airplanes. The formation of airspace, I argue, is a history particularly well...
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The potential for coring knives to cross-contaminate lettuce heads with pathogens was evaluated for both ring and blade ends. Rings and blades artificially contaminated with Escherichia coli O157:H7 (EHEC), were used to core three successive heads of iceberg lettuce. The coring rings and blades were...
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Ibrahim, M. H.; Latiff, N. A. A.; Ismail, K.; Isa, N. K. M.
2018-04-01
This study carried out to study the effect of urbanization activities towards the formation of Urban Heat Islands (UHI) in Cameron Highlands (CH).The aim of this study is to identify the formation of UHI in CH following the urbanization activities. This study also involved two main data that are primary through field survey and secondary data from collection data. In addition, this study was used qualitative and quantitative method. The data was taken two times a day, at a day and night between the hours of 12:00 to 14:00 and 19:00 to 21:00. Data in this study analyzed by using correlation analysis and analysis of Geographic Information Systems (GIS) which known as interpolation. Result found the formation of UHI in CH was concentrated at city centre namely in Pekan Tanah Rata. From the whole average value, city centre was recorded the highest reading of temperatures which is 30.5°C, while reading of temperature for subtown and suburban was recorded 28.6°C and 23.8°C. Average of humidity in CH during the day was recorded as highest reading in the suburban area namely Tringkap Bee Farm (station 11) which is 58.4%. Then, average of humidity in CH at night was recorded highest reading in the suburban area namely Habu Mini Market 91 (station 9) which the value is 83.2%. The reading of wind speed in CH during the day recorded the highest reading day at the suburban namely Tringkap Bee Farm (station 11) which the value is 2.3 m/s. While, following the reading of wind speed in CH at night, suburban namely Habu Mini Market 91(station 9) was recorded the highest reading which is 0.8 m/s. The Intensity of Urban Heat Island in CH during the day was recorded 2.8°C, while at night intensity of UHI was recorded 1.4°C. Overall, the urbanization activities in CH had caused the formation of UHI. Therefore, measures of legislation such as protect forest from development by control the urbanization activities need to be implemented so that the formation of UHI can be reduced and
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Capturing the Petermann Ice Island Flux With the CI2D3 Database
Crawford, A. J.; Crocker, G.; Mueller, D.; Saper, R.; Desjardins, L.; Carrieres, T.
2017-12-01
be utilized for the development of operational models and remote sensing tools for ice island detection, as well as assessing the distribution of Greenland Ice Sheet freshwater. The database will contribute to the study of these large, tabular icebergs that are anticipated to continue calving in both Polar Regions, including at the Petermann Glacier.
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Fogwill, Christopher J.; Van Sebille, Erik; Cougnon, Eva A.; Turney, Chris S M; Rintoul, Steve R.; Galton-Fenzi, Benjamin K.; Clark, Graeme F.; Marzinelli, E. M.; Rainsley, Eleanor B.; Carter, Lionel
2016-01-01
The dramatic calving of the Mertz Glacier tongue in 2010, precipitated by the movement of iceberg B09B, reshaped the oceanographic regime across the Mertz Polynya and Commonwealth Bay, regions where high-salinity shelf water (HSSW) - the precursor to Antarctic bottom water (AABW) - is formed. Here
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International Nuclear Information System (INIS)
Ishizawa, A.; Tokuda, S.; Wakatani, M.
2001-01-01
A seed island is required for destabilizing the neo-classical tearing mode (NTM), which degrades confinement in long sustained, high-confinement, high beta plasmas. The seed island formation due to an MHD event, such as a sawtooth crash, is investigated by applying the improved boundary layer theory of forced magnetic reconnection. This improved theory introduces the non-constant-ψ matching and reveals the complicated feature of the reconnection described by two reconnected fluxes. In the initial evolution, these reconnected fluxes grow on the time scale including the ideal time scale, typical time scale of the MHD event and the time scale of resistive kink mode. The surface current is negative, Δ' (t) A S 1/3 . (author)
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Observation of Drifting Icebergs and Sea Ice from Space by TerraSAR-X and TanDEM-X
Won, Joong-Sun
2017-04-01
Detection and monitoring drifting icebergs and sea ice is of interest across wide range of Arctic and Antarctic coastal studies such as security of navigation, climatic impact, geological impact, etc. It is not easy to discriminate drifting ices from stationary ones, and to measure their drifting speeds. There is a potential to use space-borne SAR for this purpose, but it is difficult to precisely measure because the drift velocity is usually very slow. In this study, we investigate two approaches for discriminating drifting ices on the sea from surrounding static ones and for measuring their range velocity. The first method is to utilize the quad-pol TerraSAR-X which adopts dual receive antenna (DRA), and the second one is to examine the potential use of TanDEM-X bistatic along-track interferometry (ATI). To utilize DRA mode quad-pol SAR as ATI, it is necessary to remove the phase difference of scattering centers between transmitted H- and V-pol signals. By assume that the individual scattering center of returned signal does not change for a few inter-pulse periods, it is possible to measure the Doppler frequency induced by motion through measuring slow-time (or azimuth time) Doppler phase derivative of co-pol or cross-pol pairs. Results applied to TerraSAR-X quad-pol data over the Cape Columbia in the Arctic Ocean are to be presented and discussed. It was successful to detect and measure drift sea ice that was flowing away from the antenna with a velocity of about 0.37 m/s (or 1.4 km/h) to 0.67 m/s (or 2.4 km/h) while neighboring ones were static. A more sophisticated approach would be a bistatic ATI which exploits a long along-track baseline for observation of slowly moving ground objects. TanDEM-X bistatic ATI pairs are examined, which were acquired at an Antarctic coast. The ATI interferograms show an innovative capability of TanDEM-X/TerraSAR-X constellation. An along-track baseline of a few hundred meters is superior to a few meter baseline of DRA mode ATI
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Formation and 'self-healing' of magnetic islands in finite-β Helias equilibria
International Nuclear Information System (INIS)
Hayashi, T.; Sato, T.; Merkel, P.; Nuehrenberg, J.; Schwenn, U.
1994-01-01
The behaviour of finite-pressure-induced magnetic islands is numerically analyzed for three-dimensional magnetohydrodynamic equilibria of the Helias configuration by using a three-dimensional equilibrium code. It is found that an island chain is generated on the 5/6 rational surface, when such a surface appears in the plasma region of the finite-β equilibrium. The island chain, however, is not so dangerous as to destroy the plasma confinement even if it appears in a vanishingly small shear region. Thus, a high β equilibrium with clear magnetic surfaces can be realized. Moreover, it is definitely confirmed that the finite pressure effect sometimes exhibits an unexpectedly good aspect, namely, that the vacuum islands are removed as β increases, which can be called 'self-healing' of islands. This property can be explained by the numerically discovered fact that the phases of islands induced by the finite-pressure effect are always locked in the same phase regardless of β. (author)
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Dendrochronology of Strain-Relaxed Islands
International Nuclear Information System (INIS)
Merdzhanova, T.; Kiravittaya, S.; Rastelli, A.; Stoffel, M.; Denker, U.; Schmidt, O.G.
2006-01-01
We report on the observation and study of tree-ring structures below dislocated SiGe islands (superdomes) grown on Si(001) substrates. Analogous to the study of tree rings (dendrochronology), these footprints enable us to gain unambiguous information on the growth and evolution of superdomes and their neighboring islands. The temperature dependence of the critical volume for dislocation introduction is measured and related to the composition of the islands. We show clearly that island coalescence is the dominant pathway towards dislocation nucleation at low temperatures, while at higher temperatures anomalous coarsening is effective and leads to the formation of a depletion region around superdomes
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Dendrochronology of strain-relaxed islands.
Merdzhanova, T; Kiravittaya, S; Rastelli, A; Stoffel, M; Denker, U; Schmidt, O G
2006-06-09
We report on the observation and study of tree-ring structures below dislocated SiGe islands (superdomes) grown on Si(001) substrates. Analogous to the study of tree rings (dendrochronology), these footprints enable us to gain unambiguous information on the growth and evolution of superdomes and their neighboring islands. The temperature dependence of the critical volume for dislocation introduction is measured and related to the composition of the islands. We show clearly that island coalescence is the dominant pathway towards dislocation nucleation at low temperatures, while at higher temperatures anomalous coarsening is effective and leads to the formation of a depletion region around superdomes.
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El impacto de la fusión de los icebergs en el nivel del mar
José Domingo Villarroel Villamor; Daniel Zuazagoitia Rey- Baltar
2015-01-01
Contrariamente a la creencia, muy extendida, de que la fusion de las grandes masas de hielo a la deriva en el oceano no repercute en un aumento del nivel del mar, lo cierto es que el deshielo de icebergs, barreras de hielo e incluso de la banquisa tiene, en el actual contexto de calentamiento global, un impacto nada despreciable en el nivel de los oceanos. Se presenta a continuacion una revision de este fenomeno y se propone un experimento ilustrativo que puede resultar util para ofrecer una ...
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Shape and coarsening dynamics of strained islands
DEFF Research Database (Denmark)
Schifani, Guido; Frisch, Thomas; Argentina, Mederic
2016-01-01
and numerically the formation of an equilibrium island using a two-dimensional continuous model. We have found that these equilibrium island-like solutions have a maximum height h_{0} and they sit on top of a flat wetting layer with a thickness h_{w}. We then consider two islands, and we report that they undergo...... and leads to the shrinkage of the smallest island. Once its height becomes smaller than a minimal equilibrium height h_{0}^{*}, its mass spreads over the entire system. Our results pave the way for a future analysis of coarsening of an assembly of islands....
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Sedimentary mechanisms of a modern banded iron formation on Milos Island, Greece
Directory of Open Access Journals (Sweden)
E. Chi Fru
2018-05-01
Full Text Available An early Quaternary shallow submarine hydrothermal iron formation (IF in the Cape Vani sedimentary basin (CVSB on Milos Island, Greece, displays banded rhythmicity similar to Precambrian banded iron formation (BIF. Field-wide stratigraphic and biogeochemical reconstructions show two temporal and spatially isolated iron deposits in the CVSB with distinct sedimentological character. Petrographic screening suggests the presence of a photoferrotrophic-like microfossil-rich IF (MFIF, accumulated on a basement consisting of andesites in a ∼ 150 m wide basin in the SW margin of the basin. A banded nonfossiliferous IF (NFIF sits on top of the Mn-rich sandstones at the transition to the renowned Mn-rich formation, capping the NFIF unit. Geochemical data relate the origin of the NFIF to periodic submarine volcanism and water column oxidation of released Fe(II in conditions predominated by anoxia, similar to the MFIF. Raman spectroscopy pairs hematite-rich grains in the NFIF with relics of a carbonaceous material carrying an average δ13Corg signature of ∼ −25‰. A similar δ13Corg signature in the MFIF could not be directly coupled to hematite by mineralogy. The NFIF, which postdates large-scale Mn deposition in the CVSB, is composed primarily of amorphous Si (opal-SiO2 ⋅ nH2O while crystalline quartz (SiO2 predominates the MFIF. An intricate interaction between tectonic processes, changing redox, biological activity, and abiotic Si precipitation are proposed to have collectively formed the unmetamorphosed BIF-type deposits in a shallow submarine volcanic center. Despite the differences in Precambrian ocean–atmosphere chemistry and the present geologic time, these formation mechanisms coincide with those believed to have formed Algoma-type BIFs proximal to active seafloor volcanic centers.
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Energy Sources for Yotta-TeV Iceberg Showers
Energy Technology Data Exchange (ETDEWEB)
MacAyeal, Douglas [University of Chicago
2013-05-01
In late February of 2002, warming climate along the Antarctic Peninsula triggered a macroscopic particle acceleration event that smashed a 350 Gkg floating ice shelf, called the Larsen B. The particle shower released by the acceleration involved on the order of >10^6 iceberg particles accelerated to an aggregate total kinetic energy of ~10^17 J (100 Mt TNT equivalent). The explosion was so extreme that it caught glaciological science by surprise (an injury to the egos of glaciologists worldwide) and caused glaciers of the Antarctic Peninsula formerly buttressed by the missing ice shelf to surge (yielding a small increment to sea level rise). In this presentation, I shall describe research, both experimental and field oriented, that has revealed the energy source for this explosive event. I shall also describe how climate warming has the capacity to trigger this type of ice-shelf collapse. A review of the geologic record of ice-rafted debris on the ocean floor suggests that extreme, explosive ice-shelf collapse may be a ubiquitous catastrophe that has happened regularly in the past as part of glacial/interglacial climate cycles.
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Iceberg Semantics For Count Nouns And Mass Nouns: Classifiers, measures and portions
Directory of Open Access Journals (Sweden)
Fred Landman
2016-12-01
It is the analysis of complex NPs and their mass-count properties that is the focus of the second part of this paper. There I develop an analysis of English and Dutch pseudo- partitives, in particular, measure phrases like three liters of wine and classifier phrases like three glasses of wine. We will study measure interpretations and classifier interpretations of measures and classifiers, and different types of classifier interpretations: container interpretations, contents interpretations, and - indeed - portion interpretations. Rothstein 2011 argues that classifier interpretations (including portion interpretations of pseudo partitives pattern with count nouns, but that measure interpretations pattern with mass nouns. I will show that this distinction follows from the very basic architecture of Iceberg semantics.
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Elastic energies of coherent germanium islands on silicon
International Nuclear Information System (INIS)
Vanderbilt, D.; Wickham, L.K.
1991-01-01
Motivated by recent observations of coherent Ge island formation during growth of Ge on Si (100), the authors of this paper have carried out a theoretical study of the elastic energies associated with the evolution of a uniform strained overlayer as it segregates into coherent islands. In the context of a two-dimensional model, the authors have explored the conditions under which coherent islands may be energetically favored over both uniform epitaxial films and dislocated islands. The authors find that if the interface energy (for dislocated islands) is more than about 15% of the surface energy, then there is a range of island sizes for which the coherent island structure is preferred
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Interaction of bootstrap-current-driven magnetic islands
International Nuclear Information System (INIS)
Hegna, C.C.; Callen, J.D.
1991-10-01
The formation and interaction of fluctuating neoclassical pressure gradient driven magnetic islands is examined. The interaction of magnetic islands produces a stochastic region around the separatrices of the islands. This interaction causes the island pressure profile to be broadened, reducing the island bootstrap current and drive for the magnetic island. A model is presented that describes the magnetic topology as a bath of interacting magnetic islands with low to medium poloidal mode number (m congruent 3-30). The islands grow by the bootstrap current effect and damp due to the flattening of the pressure profile near the island separatrix caused by the interaction of the magnetic islands. The effect of this sporadic growth and decay of the islands (''magnetic bubbling'') is not normally addressed in theories of plasma transport due to magnetic fluctuations. The nature of the transport differs from statistical approaches to magnetic turbulence since the radial step size of the plasma transport is now given by the characteristic island width. This model suggests that tokamak experiments have relatively short-lived, coherent, long wavelength magnetic oscillations present in the steep pressure-gradient regions of the plasma. 42 refs
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STAR FORMATION IN THE EARLY UNIVERSE: BEYOND THE TIP OF THE ICEBERG
Energy Technology Data Exchange (ETDEWEB)
Tanvir, N. R.; Wiersema, K.; O' Brien, P. T.; Starling, R. L. C. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Levan, A. J.; Stanway, E. R. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Fruchter, A. S.; Misra, K.; Graham, J. F. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Fynbo, J. P. U.; Hjorth, J.; Watson, D. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark); Bremer, M. N. [HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Rhoads, J. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Jakobsson, P. [Centre for Astrophysics and Cosmology, Science Institute, University of Iceland, Dunhagi 5, 107 Reykjavik (Iceland); Bersier, D. [Astrophysics Research Institute, Liverpool John Moores University, Liverpool (United Kingdom); Natarajan, P. [Department of Astronomy, Yale University, New Haven, CT 06511-208101 (United States); Greiner, J. [Max-Planck-Institut fuer extraterrestrische Physik, Garching bei Muenchen (Germany); Castro-Tirado, A. J. [Instituto de Astrofsica de Andalucia (IAA-CSIC), Glorieta de la Astronomia s/n, 18.008 Granada (Spain); Wijers, R. A. M. J., E-mail: nrt3@star.le.ac.uk [Astronomical Institute ' Anton Pannekoek' , P.O. Box 94248, 1090 SJ Amsterdam (Netherlands); and others
2012-07-20
We present late-time Hubble Space Telescope (HST) imaging of the fields of six Swift gamma-ray bursts (GRBs) lying at 5.0 {approx}< z {approx}< 9.5. Our data include very deep observations of the field of the most distant spectroscopically confirmed burst, GRB 090423, at z = 8.2. Using the precise positions afforded by their afterglows, we can place stringent limits on the luminosities of their host galaxies. In one case, that of GRB 060522 at z 5.11, there is a marginal excess of flux close to the GRB position which may be a detection of a host at a magnitude J{sub AB} Almost-Equal-To 28.5. None of the others are significantly detected, meaning that all the hosts lie below L* at their respective redshifts, with star formation rates (SFRs) {approx}< 4 M{sub Sun} yr{sup -1} in all cases. Indeed, stacking the five fields with WFC3-IR data, we conclude a mean SFR <0.17 M{sub Sun} yr{sup -1} per galaxy. These results support the proposition that the bulk of star formation, and hence integrated UV luminosity, at high redshifts arises in galaxies below the detection limits of deep-field observations. Making the reasonable assumption that GRB rate is proportional to UV luminosity at early times allows us to compare our limits with expectations based on galaxy luminosity functions (LFs) derived from the Hubble Ultra-Deep Field and other deep fields. We infer that an LF, which is evolving rapidly toward steeper faint-end slope ({alpha}) and decreasing characteristic luminosity (L*), as suggested by some other studies, is consistent with our observations, whereas a non-evolving LF shape is ruled out at {approx}> 90% confidence. Although it is not yet possible to make stronger statements, in the future, with larger samples and a fuller understanding of the conditions required for GRB production, studies like this hold great potential for probing the nature of star formation, the shape of the galaxy LF, and the supply of ionizing photons in the early universe.
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International Nuclear Information System (INIS)
Diaz M, Juan Manuel; Garcia Llano, Cesar Fernando
2010-01-01
San Andres Island is the largest emerged portion of the oceanic archipelago of San Andres and Providencia, southwestern Caribbean Sea; it originated as a coralline atoll during Miocene times. The central and highest part of the island consists of a calcareous crest, the San Andres Formation, formed by Neogene lagoonal and reefal deposits. This crest is surrounded by a calcareous platform of Pleistocene age (San Luis Formation) which emerges only along the island coast, whereas its most part is submerged and covered by a Recent reef complex. Fossil material of molluscs from these two formations was collected in various sites throughout the island and taxonomically identified. In the four sites sampled in the San Andres Formation, material belonging to 19 gastropod and 37 bivalve species was obtained, most of them relatively well represented in other geologic formations of the Caribbean region that are stratigraphically situated between the upper Miocene and the middle Pliocene. Some elements occurring in this formation, such as Ostrea haitiensis, Meretrix dariena and Siphocypraea henekeni, were widely distributed in the Caribbean Miocene Province. In the San Luis Formation, material belonging to 18 gastropod and 11 bivalve species was obtained, most of them also represented in the Recent molluscan fauna of the region. The estimated age of this formation is Sangamonian, hence corresponding to similar formations occurring in Grand Cayman, Jamaica, Hispaniola, the Netherlands Antilles and other Caribbean islands, with which it also shows a great similarity in the composition of the molluscan fauna.
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Degradation of mangrove tissues and implications for peat formation in Belizean island forests
Middleton, B.A.; McKee, K.L.
2001-01-01
1. Macrofaunal leaf consumption and degradation of leaves, woody twigs and roots were studied in mangrove island forests on a Belizean island. Factors influencing accumulation of organic matter deposited both above and below ground in this oligotrophic, autochothonous system were assessed. 2. Leaf degradation rates of Rhizophora mangle (red mangrove), Avicennia germinans (black mangrove) and Laguncularia racemosa (white mangrove) measured in mesh bags, were much faster in the lower than the upper intertidal zone. Mass loss was most rapid in A. germinans but zonal effects were much larger than species differences. 3. Exposure to invertebrates such as crabs and amphipods tripled overall rates of leaf litter breakdown. In the lower intertidal, crabs completely consumed some unbagged leaves within 23 days. Crabs also had an effect on some upper intertidal sites, where degradation of leaves placed in artificial burrows was 2.4 times faster than when placed on the soil surface. 4. In contrast to leaves (27??5% remaining after 230 days), roots and woody twigs were highly refractory (40??2% and 51??6% remaining after 584 and 540 days, respectively). Root degradation did not vary by soil depth, zone or species. Twigs of R. mangle and A. germinans degraded faster on the ground than in the canopy, whereas those of L. racemosa were highly resistant to decay regardless of position. 5. Peat formation at Twin Cays has occurred primarily through deposition and slow turnover of mangrove roots, rather than above-ground tissues that are either less abundant (woody twigs) or more readily removed (leaves).
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CRED 20m Gridded bathymetry of Necker Island, Hawaii, USA (Arc ASCII format)
National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry of the shelf and slope environments of Necker Island, Northwestern Hawaiian Islands, Hawaii, USA. This ASCII includes multibeam bathymetry from...
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El impacto de la fusión de los icebergs en el nivel del mar
Directory of Open Access Journals (Sweden)
José Domingo Villarroel Villamor
2015-01-01
Full Text Available Contrariamente a la creencia, muy extendida, de que la fusion de las grandes masas de hielo a la deriva en el oceano no repercute en un aumento del nivel del mar, lo cierto es que el deshielo de icebergs, barreras de hielo e incluso de la banquisa tiene, en el actual contexto de calentamiento global, un impacto nada despreciable en el nivel de los oceanos. Se presenta a continuacion una revision de este fenomeno y se propone un experimento ilustrativo que puede resultar util para ofrecer una experiencia directa relativa al impacto que sobre el nivel del mar tiene la fusion del hielo flotante en el oceano.
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Fracture-zone tectonics at Zabargad Island, Red Sea (Egypt)
Marshak, Stephen; Bonatti, Enrico; Brueckner, Hannes; Paulsen, Timothy
1992-12-01
Zabargad Island, which lies along the western margin of the Red Sea rift, is a remarkable place because it provides fresh exposures of undepleted mantle peridotite. How this peridotite came to be exposed on Zabargad remains unclear. Our field mapping indicates that most of the contacts between peridotite and the adjacent bodies of Pan-African gneiss and Cretaceous(?) Zabargad Formation on the island are now high-angle brittle faults. Zabargad Formation strata have been complexly folded, partly in response to this faulting. Overall, the array of high-angle faults and associated folds on the island resembles those found in cross-rift transfer zones. We suggest, therefore, that the Zabargad fracture zone, a band of submarine escarpments on the floor of the Red Sea north of the island, crosses Zabargad Island and has actively resolved differential movement between the central Red Sea rift and the northern Red Sea rift. The final stage of uplift that brought the unusual peridotite to the earth's surface is related to shallow crustal transpression, which may have inverted an earlier transtensional regime.
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Leli, Isabel T.; Stevaux, José C.; Assine, Mário L.
2018-02-01
Blind channel (BC) is a fluvial feature formed by attachment of a lateral sand bar to an island or riverbank. It consists of a 10- to 20-m wide and hundreds to thousands meters long channel, parallel to the island or bank, closed at its upstream end by accretion to the island. It is an important feature in anabranching rivers that plays an important role in both the island formation and river ecology. This paper discusses the formation processes, functioning, evolution, and the sedimentary record of a blind channel, related landforms, and its context on island development in the Upper Paraná River. The evolution of this morphologic feature involves (1) formation of a lateral or attachment bar beside an island with the development of a channel in between; (2) vertical accretion of mud deposits during the flood and vegetal development on the bar; (3) the upstream channel closure that generates the blind channel; and (4) annexation of the blind channel to the island. A blind channel is semilotic to lentic, that is not totally integrated to the dynamics of the main active channel and that acts as a nursery for fingerlings and macrophytes. The sedimentary facies succession of BCs are relatively simple and characterized by cross-stratified sand covered by organic muddy sediments. Based on facies analysis of 12 cores, we identified a succession of environments that contribute to the formation of islands: channel bar, blind channel, pond, and swamp. Blind channel formation and its related bar-island attachment are relevant processes associated with the growing of large island evolution in some anabranching rivers.
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Formation of magnetic islands due to field perturbations in toroidal stellarator configurations
International Nuclear Information System (INIS)
Lee, D.K.; Harris, J.H.; Lee, G.S.
1990-06-01
An explicit formulation is developed to determine the width of a magnetic island separatrix generated by magnetic field perturbations in a general toroidal stellarator geometry. A conventional method is employed to recast the analysis in a magnetic flux coordinate system without using any simplifying approximations. The island width is seen to be proportional to the square root of the Fourier harmonic of B ρ /B ζ that is in resonance with the rational value of the rotational transform, where B ρ and B ζ are contravariant normal and toroidal components of the perturbed magnetic field, respectively. The procedure, which is based on a representation of three-dimensional flux surfaces by double Fourier series, allows rapid and fairly accurate calculation of the island widths in real vacuum field configurations, without the need to follow field lines through numerical integration of the field line equations. Numerical results of the island width obtained in the flux coordinate representation for the Advanced Toroidal Facility agree closely with those determined from Poincare puncture points obtained by following field lines. 22 refs., 5 tabs
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Late Quaternary climate change shapes island biodiversity.
Weigelt, Patrick; Steinbauer, Manuel Jonas; Cabral, Juliano Sarmento; Kreft, Holger
2016-04-07
Island biogeographical models consider islands either as geologically static with biodiversity resulting from ecologically neutral immigration-extinction dynamics, or as geologically dynamic with biodiversity resulting from immigration-speciation-extinction dynamics influenced by changes in island characteristics over millions of years. Present climate and spatial arrangement of islands, however, are rather exceptional compared to most of the Late Quaternary, which is characterized by recurrent cooler and drier glacial periods. These climatic oscillations over short geological timescales strongly affected sea levels and caused massive changes in island area, isolation and connectivity, orders of magnitude faster than the geological processes of island formation, subsidence and erosion considered in island theory. Consequences of these oscillations for present biodiversity remain unassessed. Here we analyse the effects of present and Last Glacial Maximum (LGM) island area, isolation, elevation and climate on key components of angiosperm diversity on islands worldwide. We find that post-LGM changes in island characteristics, especially in area, have left a strong imprint on present diversity of endemic species. Specifically, the number and proportion of endemic species today is significantly higher on islands that were larger during the LGM. Native species richness, in turn, is mostly determined by present island characteristics. We conclude that an appreciation of Late Quaternary environmental change is essential to understand patterns of island endemism and its underlying evolutionary dynamics.
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of Northampton Seamounts to Laysan Island, Northwestern Hawaiian Islands, Hawaii,...
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of Northampton Seamounts to Laysan Island, Northwestern Hawaiian Islands, Hawaii,...
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International Nuclear Information System (INIS)
Bhattacharjee, A.; Hayashi, T.; Hegna, C.C.; Nakajima, N.; Sato, T.
1994-11-01
The role of singular currents in three-dimensional toroidal equilibria and their resolution by magnetic island formation is discussed from both analytical and computational points of view. Earlier analytical results are extended to include small vacuum islands which may, in general, have different phases with respect to pressure-induced islands. In currentless stellarators, the formation of islands is shown to depend on the resistive parameter D R as well as the integrated effect of global Pfirsch-Schlueter currents. It is demonstrated that the pressure-induced 'self-healing' effect, recently discovered computationally, is also predicted by analytical theory. (author)
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Evidence for coral island formation during rising sea level in the central Pacific Ocean
Kench, Paul S.; Owen, Susan D.; Ford, Murray R.
2014-02-01
The timing and evolution of Jabat Island, Marshall Islands, was investigated using morphostratigraphic analysis and radiometric dating. Results show the first evidence of island building in the Pacific during latter stages of Holocene sea level rise. A three-phase model of development of Jabat is presented. Initially, rapid accumulation of coarse sediments on Jabat occurred 4800-4000 years B.P. across a reef flat higher than present level, as sea level continued to rise. During the highstand, island margins and particularly the western margin accreted vertically to 2.5-3.0 m above contemporary ridge elevations. This accumulation phase was dominated by sand-size sediments. Phase three involved deposition of gravel ridges on the northern reef, as sea level fell to present position. Jabat has remained geomorphically stable for the past 2000 years. Findings suggest reef platforms may accommodate the oldest reef islands in atoll systems, which may have profound implications for questions of prehistoric migration through Pacific archipelagos.
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Bifurcated states of the error-field-induced magnetic islands
International Nuclear Information System (INIS)
Zheng, L.-J.; Li, B.; Hazeltine, R.D.
2008-01-01
We find that the formation of the magnetic islands due to error fields shows bifurcation when neoclassical effects are included. The bifurcation, which follows from including bootstrap current terms in a description of island growth in the presence of error fields, provides a path to avoid the island-width pole in the classical description. The theory offers possible theoretical explanations for the recent DIII-D and JT-60 experimental observations concerning confinement deterioration with increasing error field
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Barrier island facies models and recognition criteria
Mulhern, J.; Johnson, C. L.
2017-12-01
Barrier island outcrops record transgressive shoreline motion at geologic timescales, providing integral clues to understanding how coastlines respond to rising sea levels. However, barrier island deposits are difficult to recognize. While significant progress has been made in understanding the modern coastal morphodynamics, this insight is not fully leveraged in existing barrier island facies models. Excellent outcrop exposures of the paralic Upper Cretaceous Straight Cliffs Formation of southern Utah provide an opportunity to revise facies models and recognition criteria for barrier island deposits. Preserved barrier islands are composed of three main architectural elements (shorefaces, tidal inlets, and tidal channels) which occur independently or in combination to create larger-scale barrier island deposits. Barrier island shorefaces record progradation, while barrier island tidal inlets record lateral migration, and barrier island tidal channels record aggradation within the tidal inlet. Four facies associations are used to describe and characterize these barrier island architectural elements. Barrier islands occur in association with backarrier fill and internally contain lower and upper shoreface, high-energy upper shoreface, and tidal channel facies. Barrier islands bound lagoons or estuaries, and are distinguished from other shoreface deposits by their internal facies and geometry, association with backbarrier facies, and position within transgressive successions. Tidal processes, in particular tidal inlet migration and reworking of the upper shoreface, also distinguish barrier island deposits. Existing barrier island models highlight the short term heterogeneous and dynamic nature of barrier island systems, yet overlook processes tied to geologic time scales, such as multi-directional motion, erosion, and reworking, and their expressions in preserved barrier island strata. This study uses characteristic outcrop expressions of barrier island successions to
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded (5 m cell size) bathymetry of the shelf and slope environments of Baker Island, Pacific Remote Isand Areas, Central Pacific. Almost complete bottom coverage...
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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
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Low permeability volcanics in the Canary Islands (Spain)
International Nuclear Information System (INIS)
Custodio, E.
1985-01-01
The Canary Islands, about 2000 km to the SW of continental Spain, are fully volcanic, from mid Miocene to recent. The permeability of the formations depends very much on the age and lithology. In most instances young, pervious basalts are devoid of water due to their altitude and most water abstraction works must go into the underlaying, much less pervious, older formations. Long water galleries or large diameter wells fitted with a crown of horizontal bores are able to catch significant quantities of water from formations which permeability is less than 0.1 m/day. The anisotropic behavior of the formations, specially due to the injection of subvertical dykes parallel to the coast, explains the high hydraulic gradient found, up to 0.15, and the relative high yield of the wells and galleries. The specific yield of the volcanics is fairly high, about 0.02 to 0.05, thus allowing the use of reserves to supply the demand. Conventional finite-difference models give a sound picture of the groundwater behavior but preliminary adjustments of the hydraulic parameters need the study of simplified cross-sections. The study of the chemical characteristics of groundwater is a key factor in the understanding of groundwater flow. The discussion refers mainly to Lanzarote, Tenerife and Gran Canaria Islands, but some comment will use information from other islands. 23 references, 10 figures, 2 tables
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Rogers, Karyne M; Nicolini, Eric; Gauthier, Virginie
2012-09-01
Nitrate concentrations, water isotopes (δ(2)H and δ(18)O(water)) and associated nitrate isotopes (δ(15)N(nitrate) and δ(18)O(nitrate)) from 10 drinking water wells, 5 fresh water springs and the discharge from 3 wastewater treatment stations in Réunion Island, located in the Indian Ocean, were analysed. We used a multi isotopic approach to investigate the extent of nitrate contamination, nitrate formation altitude and source of nitrates in Réunion Island's principal aquifer. Water from these study sites contained between 0.1 and 85.3 mg/L nitrate. δ(15)N(nitrate) values between +6 and +14‰ suggested the main sources of contamination were animal and/or human waste, rather than inorganic (synthetic) fertilisers, infiltrating through the subsurface into the saturated zone, due to rainfall leaching of the unsaturated zone at various altitudes of precipitation. Based on δ(15)N(nitrate) values alone, it was not possible to distinguish between animal and human activities responsible for the contamination of each specific catchment. However, using a multi isotope approach (δ(18)O(water) and δ(15)N(nitrate)), it was possible to relate the average altitude of rainfall infiltration (δ(18)O(water)) associated with the nitrate contamination (δ(18)O(nitrate)). This relationship between land use, rainfall recharge altitude and isotopic composition (δ(15)N(nitrate) and δ(18)O(water)) discriminated between the influences of human waste at lower (below 600 m elevation) or animal derived contamination (at elevations between 600 and 1300 m). By further comparing the theoretical altitude of nitrate formation calculated by the δ(18)O(nitrate), it was possible to determine that only 5 out of 15 fresh water wells and springs followed the conservative nitrate formation mechanism of 2/3δ(18)O(water)+1/3δ(18)O(air), to give nitrate formation altitudes which corresponded to land use activities. Copyright © 2012 Elsevier B.V. All rights reserved.
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Behavior of magnetic islands in 3D MHD equilibria of helical devices
International Nuclear Information System (INIS)
Hayashi, T.; Sato, T.; Nakajima, N.
1994-09-01
Magnetic island formation in three-dimensional finite-β equilibria in the H-1 Heliac is studied by using the HINT code. It is found that the size of a dangerous island should increase with β but that a destruction of the equilibrium at low β is avoided because the rotational transform evolves to exclude the rational surface concerned. At higher β there is evidence of near-resonant flux surface deformations which may lead to an equilibrium limit. A reconnected equilibrium at still higher β exhibits a double island structure which is similar to homoclinic phase portraits which have been observed after separatrix reconnection in Hamiltonian systems. Physical mechanism of the island formation in finite-β helical equilibria is investigated to confirm there are cases where the global effect of the Pfirsch-Schlueter currents is important. The earlier theory is extended to elucidate the occurence of the complete self-healing of island when the resistive interchange criterion satisfied. (author)
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Anciet marble quarries in Lesvos island Greece
Mataragkas, M.; Mataragkas, D.
2009-04-01
ANCIENT MARBLE QUARRIES IN LESBOS ISLAND, GREECE Varti- Matarangas M.1 & Matarangas D. 1 Institute of Geological and Mining Exploration (IGME), Olympic Village, Entrance C, ACHARNAE 13677, GREECE myrsini@igme.gr , myrsini@otenet.g r A B S T R A C T Ten ancient marble quarries of Lesbos Island, most of them previously unknown, have been studied, in the frame of the research study on the ancient marble quarries in the Aegean Sea. In the present paper the geological, petrological and morphological features of the aforementioned quarries are examined. Concerning the six ancient quarries located in the areas of Tarti, Agia Paraskevi (Tsaf), Mageiras, Loutra, Latomi (Plomari) and Thermi, the authochthonous neopaleozoic unit constitutes their geological formation, while their hosting lithological formations are the included crystalline limestone lens like beds. In two ancient quarries in the areas Moria and Alyfanta, the geological formation is the authochthonous upper Triassic series and the hosting lithological formation the upper Triassic carbonate sequence, while in the areas of Akrasi-Abeliko and Karyni, the geological formation is the thrust Triassic unit and the lithological hosting formations are the included strongly deformed or not crystalline limestone lenticular beds. Furthermore, the petrographic features were also determined permitting the identification of the building stones that have been used.
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VAN der Linden, Inge; Eriksson, Markus; Uyttendaele, Mieke; Devlieghere, Frank
2016-10-01
To prevent contamination of fresh produce with enteric pathogens, more insight into mechanisms that may influence the association of these pathogens with fresh produce is needed. In this study, Escherichia coli O157:H7 and Salmonella were chosen as model pathogens, and fresh cut iceberg lettuce was chosen as a model fresh produce type. The morphological structure of iceberg lettuce leaves (stomatal density and length of cell margins per leaf area) was quantified by means of leaf peels and light microscopy of leaves at different stages of development (outer, middle, and inner leaves of the crop) on both leaf sides (abaxial and adxial) and in three leaf regions (top, center, and bottom). The morphology of the top region of the leaves was distinctly different from that of the center and base, with a significantly higher stomatal density (up to five times more stomata), different cell shape, and longer cell margins (two to three times longer). Morphological differences between the same regions of the leaves at different stages of development were smaller or nonsignificant. An attachment assay with two attenuated E. coli O157:H7 strains (84-24h11-GFP and BRMSID 188 GFP) and two Salmonella strains (serovars Thompson and Typhimurium) was performed on different regions of the middle leaves. Our results confirmed earlier reports that these pathogens have a higher affinity for the base of the lettuce leaf than the top. Differences of up to 2.12 log CFU/g were seen ( E. coli O157:H7 86-24h11-GFP). Intermediate attachment occurred in the central region. The higher incidence of preferential bacterial attachment sites such as stomata and cell margins or grooves could not explain the differences observed in the association of the tested pathogens with different regions of iceberg lettuce leaves.
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Plasma flow healing of magnetic islands in stellarators
International Nuclear Information System (INIS)
Hegna, C. C.
2012-01-01
Recent experiments from the large helical device (LHD) demonstrate a correlation between the “healing” of vacuum magnetic islands in stellarators and changes in the plasma flow. A model explaining this phenomenon is developed based on self-consistent torque balance and island evolution equations. In conventional stellarators, neoclassical flow damping physics plays an important role in establishing the flow profiles. The balance of neoclassical damping and cross-field viscosity produces a radial boundary layer for the plasma rotation profile outside the separatrix of a locked magnetic island. The width of this boundary layer decreases as the plasma becomes less collisional. Associated with these flow effects are plasma currents flowing in the island region that attempt to suppress island formation. These currents are enhanced as the collisionality drops making magnetic island healing occur more readily in high temperature conventional stellarators. The analytic theory produces a critical β for healing that scales monotonically with collisionality and is in qualitative agreement with LHD observations.
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Ilieva-Makulec, K.; Bjarnadottir, B.; Sigurdsson, B. D.
2014-10-01
The soil nematode fauna can give important insights into soil development and other habitat changes that occur during primary succession. We investigated the generic composition, density, distribution and community structure of nematodes 50 years after the formation of a pristine volcanic island, Surtsey, Iceland. Part of the island has received additional nutrient inputs from seagulls breeding there since 1985, while the reminder has been much less affected and is at present found at a different successional sere. In total, 25 genera of nematodes were identified, of which 14 were reported on Surtsey for the first time. Nematode communities were more diverse in the more infertile area outside the gull colony, where 24 genera were found, compared to 18 inside. The trophic structure of the nematode communities showed relatively higher abundance of fungal feeders in the infertile areas, but relatively more bacterial- and plant-feeders inside the colony. Nematode abundance in surface soil was, however, significantly higher within the gull colony, with 16.7 ind. cm-2 compared to 3.6 ind. cm-2 outside. A multivariate analysis indicated that the nematode abundance and distribution on Surtsey were most strongly related to the soil C : N ratio, soil acidity, plant cover and biomass, soil temperature and soil depth.
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Control of size and density of InAs/(Al,Ga)As self-organized islands
International Nuclear Information System (INIS)
Ballet, P.; Smathers, J. B.; Yang, H.; Workman, C. L.; Salamo, G. J.
2001-01-01
We report on the influence of the chemical composition of the (Al,Ga)As surface on the formation of strain induced three-dimensional (3D) InAs islands. The experiments have been carried out using a molecular beam epitaxy facility combined with a scanning tunneling microscope enabling in situ surface characterization. The evolution of the density and morphology of these islands is investigated as a function of the Al composition. The InAs deposition, substrate temperature, and annealing time effects on the island formation and morphology are studied. The morphologies of the (Al,Ga)As surface as well as that of the reconstructed InAs 'wetting layer' are also described. Results indicate that there are major differences between the InAs/GaAs and the InAs/AlAs systems despite the same lattice mismatch. We observe these differences varying the aluminum content in the starting (Al,Ga)As surface. We show that control of the Al fraction leads to control of the size and density of the 3D islands. The control of island density and size as well as the growth mode of these islands is explained by considering the difference in surface mobility and cation intermixing between these two systems. Our observation is that strain energy is not the only parameter governing the formation of 3D islands but the chemical nature of the different layers involved is proved to significantly affect island properties. [copyright] 2001 American Institute of Physics
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Energy Technology Data Exchange (ETDEWEB)
Loizu, J., E-mail: joaquim.loizu@ipp.mpg.de [Max-Planck-Institut für Plasmaphysik, D-17491 Greifswald (Germany); Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton New Jersey 08543 (United States); Hudson, S.; Bhattacharjee, A. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton New Jersey 08543 (United States); Helander, P. [Max-Planck-Institut für Plasmaphysik, D-17491 Greifswald (Germany)
2015-02-15
Using the recently developed multiregion, relaxed MHD (MRxMHD) theory, which bridges the gap between Taylor's relaxation theory and ideal MHD, we provide a thorough analytical and numerical proof of the formation of singular currents at rational surfaces in non-axisymmetric ideal MHD equilibria. These include the force-free singular current density represented by a Dirac δ-function, which presumably prevents the formation of islands, and the Pfirsch-Schlüter 1/x singular current, which arises as a result of finite pressure gradient. An analytical model based on linearized MRxMHD is derived that can accurately (1) describe the formation of magnetic islands at resonant rational surfaces, (2) retrieve the ideal MHD limit where magnetic islands are shielded, and (3) compute the subsequent formation of singular currents. The analytical results are benchmarked against numerical simulations carried out with a fully nonlinear implementation of MRxMHD.
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Pereyra, Y.; Ma, L.; Sak, P. B.; Gaillardet, J.; Buss, H. L.; Brantley, S. L.
2015-12-01
Dust inputs play an important role in soil formation, especially for thick soils developed on tropical volcanic islands. In these regions, soils are highly depleted due to intensive chemical weathering, and mineral nutrients from dusts have been known to be important in sustaining soil fertility and productivity. Tropical volcanic soils are an ideal system to study the impacts of dust inputs on the ecosystem. Sr and U-series isotopes are excellent tracers to identify sources of materials in an open system if the end-members have distinctive isotope signatures. These two isotope systems are particularly useful to trace the origin of atmospheric inputs into soils and to determine rates and timescales of soil formation. This study analyzes major elemental concentrations, Sr and U-series isotope ratios in highly depleted soils in the tropical volcanic island of Basse-Terre in French Guadeloupe to determine atmospheric input sources and identify key soil formation processes. We focus on three soil profiles (8 to 12 m thick) from the Bras-David, Moustique Petit-Bourg, and Deshaies watersheds; and on the adjacent rivers to these sites. Results have shown a significant depletion of U, Sr, and major elements in the deep profile (12 to 4 m) attributed to rapid chemical weathering. The top soil profiles (4 m to the surface) all show addition of elements such as Ca, Mg, U, and Sr due to atmospheric dust. More importantly, the topsoil profiles have distinct Sr and U-series isotope compositions from the deep soils. Sr and U-series isotope ratios of the top soils and sequential extraction fractions confirm that the sources of the dust are from the Saharan dessert, through long distance transport from Africa to the Caribbean region across the Atlantic Ocean. During the transport, some dust isotope signatures may also have been modified by local volcanic ashes and marine aerosols. Our study highlights that dusts and marine aerosols play important roles in element cycles and
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Energy Technology Data Exchange (ETDEWEB)
Wang, Wei; Li, Lingzi; Zhou, Qian [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Pan, Jisheng; Zhang, Zheng [Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore); Tok, Eng Soon [Department of Physics, National University of Singapore, Singapore 117551 (Singapore); Yeo, Yee-Chia, E-mail: yeo@ieee.org [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)
2014-12-01
Highlights: • Ge{sub 0.915}Sn{sub 0.085} was grown on Ge (0 0 1) by molecular beam epitaxy (MBE). • The impact of annealing on surface morphology and Sn composition was studied. • Sn is found to preferentially segregate towards the surface at 200 °C. • A Sn-rich layer would form on the Ge{sub 1−x}Sn{sub x} surface after annealing at 300 °C. • Sn desorption and formation of Sn-rich islands were found when T > 300 °C. - Abstract: Annealing of strained Ge{sub 1−x}Sn{sub x} epitaxial layers grown on Ge(0 0 1) substrate results in two distinctive regimes marked by changes in composition and morphology. Annealing at low temperatures (200–300 °C or Regime-I) leads to surface enrichment of Sn due to Sn segregation, as indicated by X-ray photoelectron spectroscopy (XPS) results, while the bulk Sn composition (from X-ray diffraction (XRD)) and the surface morphology (from atomic force microscopy (AFM)) do not show discernible changes as compared to the as-grown sample. Annealing at temperatures ranging from 300 °C to 500 °C (Regime-II) leads to a decrease in the surface Sn composition. While the Ge{sub 1−x}Sn{sub x} layer remains fully strained, a reduction in the bulk Sn composition is observed when the annealing temperature reaches 500 °C. At this stage, surface roughening also occurs with formation of 3D islands. The island size increases as the annealing temperature is raised to 600 °C. The decrease in the Sn composition at the surface and in the bulk in Regime-II is attributed to additional thermally activated kinetic processes associated with Sn desorption and formation of Sn-rich 3D islands on the surface.
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DEFF Research Database (Denmark)
Shah, Peter Jivan; Mouritsen, Ole G.
1990-01-01
The dynamics of the ordering processes in two-dimensional lattice models with annealed vacancies and nonconserved order parameter is studied as a function of temperature and vacancy concentration by means of Monte Carlo temperature-quenching simulations. The models are Ising antiferromagnets...... with couplings leading to twofold-degenerate as well as fourfold-degenerate ordering. The models are quenched into a phase-separation region, which makes it possible for both types of ordering to observe the following scenario of ordering processes: (i) early-time nucleation and growth of ordered domains, (ii......) intermediate-time trapping of the mobile vacancies at the domain boundaries, and (iii) late-time diffusion of vacancies along the domain-boundary network towards the surface. In the case of high dilution, the ordering processes correspond to early-time island formation and late-time coarsening...
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International Nuclear Information System (INIS)
Han, Yong; Lii-Rosales, A.; Zhou, Y.; Wang, C.-J.
2017-01-01
Theory and stochastic lattice-gas modeling is developed for the formation of intercalated metal islands in the gallery between the top layer and the underlying layer at the surface of layered materials. Our model for this process involves deposition of atoms, some fraction of which then enter the gallery through well-separated pointlike defects in the top layer. Subsequently, these atoms diffuse within the subsurface gallery leading to nucleation and growth of intercalated islands nearby the defect point source. For the case of a single point defect, continuum diffusion equation analysis provides insight into the nucleation kinetics. However, complementary tailored lattice-gas modeling produces a more comprehensive and quantitative characterization. We analyze the large spread in nucleation times and positions relative to the defect for the first nucleated island. We also consider the formation of subsequent islands and the evolution of island growth shapes. The shapes reflect in part our natural adoption of a hexagonal close-packed island structure. As a result, motivation and support for the model is provided by scanning tunneling microscopy observations of the formation of intercalated metal islands in highly-ordered pyrolytic graphite at higher temperatures.
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Magnetite nano-islands on Graphene
Anderson, Nathaniel; Zhang, Qiang; Rosenberg, Richard; Vaknin, David
X-ray magnetic circular dichroism (XMCD) of ex-situ iron nano-islands grown on graphene reveals that iron oxidation spontaneously leads to the formation of magnetite nano-particles - i.e, the formation of the inverse spinel Fe3O4. Fe islands have been grown with two different heights (20 and 75 MLs) on epitaxial graphene and we have determined their magnetic behavior both as function of temperature and applied external field. Our XAS and XMCD at an applied magnetic field of B = 5 T show that the thin film (20 MLs) is totally converted to magnetite whereas the thicker film (75 MLs) exhibits magnetite properties but also those of pure metal iron. For both samples, temperature dependence of the XMCD shows clear transitions at ~120 K consistent with the Verwey transition of bulk magnetite. XMCD at low temperatures shows a weak hysteresis and provide the average spin and angular-momentum moments, the dipolar term, and the total moment . In addition, manipulation and comparison of the XMCD data from both samples allows us to extract information about the pure iron nano-islands from the thicker sample. Ames Laboratory is supported by the U.S. DOE, BES, MSE Contract No. DE-AC02-07CH11358. APS is supported by U.S. DOE Contract No. DE-AC02-06CH11357.
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Analysis of volcano rock from Canary islands
International Nuclear Information System (INIS)
Sitek, J.; Sedlackova, K.; Dekan, J.
2013-01-01
In this work we have analyzed the basalt rock from Lanzarote, which is the easternmost island of the Canary Islands lying in the Atlantic Ocean and has a volcanic origin. It was born through fiery eruptions and has solidified lava streams as well as extravagant rock formations. We compared our results with composition of basalt rocks from some other places on the Earth. Different iron oxides created on the volcanic rocks during their weathering on the Earth surface has been also analyzed. (authors)
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Wave inhibition by sea ice enables trans-Atlantic ice rafting of debris during Heinrich Events
Wagner, T. J. W.; Dell, R.; Eisenman, I.; Keeling, R. F.; Padman, L.; Severinghaus, J. P.
2017-12-01
The thickness of the ice-rafted debris (IRD) layers that signal Heinrich Events declines far more gradually with distance from the iceberg sources than would be expected based on present-day iceberg trajectories. Here we model icebergs as passive Lagrangian tracers driven by ocean currents, winds, and sea surface temperatures. The icebergs are released in a comprehensive climate model simulation of the last glacial maximum (LGM), as well as a simulation of the modern climate. The two simulated climates result in qualitatively similar distributions of iceberg meltwater and hence debris, with the colder temperatures of the LGM having only a relatively small effect on meltwater spread. In both scenarios, meltwater flux falls off rapidly with zonal distance from the source, in contrast with the more uniform spread of IRD in sediment cores. In order to address this discrepancy, we propose a physical mechanism that could have prolonged the lifetime of icebergs during Heinrich events. The mechanism involves a surface layer of cold and fresh meltwater formed from, and retained around, densely packed armadas of icebergs. This leads to wintertime sea ice formation even in relatively low latitudes. The sea ice in turn shields the icebergs from wave erosion, which is the main source of iceberg ablation. We find that allowing sea ice to form around all icebergs during four months each winter causes the model to approximately agree with the distribution of IRD in sediment cores.
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Lee, C.-T.A.; Morton, D.M.; Kistler, R.W.; Baird, A.K.
2007-01-01
Mesozoic continental arcs in the North American Cordillera were examined here to establish a baseline model for Phanerozoic continent formation. We combine new trace-element data on lower crustal xenoliths from the Mesozoic Sierra Nevada Batholith with an extensive grid-based geochemical map of the Peninsular Ranges Batholith, the southern equivalent of the Sierras. Collectively, these observations give a three-dimensional view of the crust, which permits the petrogenesis and tectonics of Phanerozoic crust formation to be linked in space and time. Subduction of the Farallon plate beneath North America during the Triassic to early Cretaceous was characterized by trench retreat and slab rollback because old and cold oceanic lithosphere was being subducted. This generated an extensional subduction zone, which created fringing island arcs just off the Paleozoic continental margin. However, as the age of the Farallon plate at the time of subduction decreased, the extensional environment waned, allowing the fringing island arc to accrete onto the continental margin. With continued subduction, a continental arc was born and a progressively more compressional environment developed as the age of subducting slab continued to young. Refinement into a felsic crust occurred after accretion, that is, during the continental arc stage, wherein a thickened crustal and lithospheric column permitted a longer differentiation column. New basaltic arc magmas underplate and intrude the accreted terrane, suture, and former continental margin. Interaction of these basaltic magmas with pre-existing crust and lithospheric mantle created garnet pyroxenitic mafic cumulates by fractional crystallization at depth as well as gabbroic and garnet pyroxenitic restites at shallower levels by melting of pre-existing lower crust. The complementary felsic plutons formed by these deep-seated differentiation processes rose into the upper crust, stitching together the accreted terrane, suture and former
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Acinetobacter lactucae sp. nov., isolated from iceberg lettuce (Asteraceae: Lactuca sativa).
Rooney, Alejandro P; Dunlap, Christopher A; Flor-Weiler, Lina B
2016-09-01
Strain NRRL B-41902T and three closely related strains were isolated from iceberg lettuce. The strain was found to consist of strictly aerobic, Gram-stain-negative rods that formed cocci in late stationary phase. 16S rRNA gene sequence analysis showed that strain NRRL B-41902T was most closely related to species within the genera Acinetobacter, and that a grouping of it and the three other closely related strains was most closely related to the type strain of Acinetobacter pittii, which was also confirmed through a phylogenomic analysis. Moreover, in silico DNA-DNA hybridization analysis revealed a substantial amount of genomic divergence (39.1 %) between strain NRRL B-41902T and the type strain of A. pittii, which is expected if the strains represent distinct species. Further phenotypic analysis revealed that strain NRRL B-41902T was able to utilize a combination of l-serine, citraconic acid and citramalic acid, which differentiated it from other, closely related Acinetobacter species. Therefore, strain NRRL B-41902T (=CCUG 68785T) is proposed as the type strain of a novel species, Acinetobacter lactucae sp. nov.
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Attachment icebergs: Maternal and child health nurses' evaluation of infant-caregiver attachment.
Bryant, Edith; Ridgway, Lael; Lucas, Sandra
2016-05-01
Secure attachment of infants to their caregiver is important when promoting the emotional wellbeing and mental health of infants. Maternal and child health (MCH) nurses are well positioned to observe the quality of interactions between infants and caregivers and to assess and intervene. However, as yet there are no approved methods to assess the emotional and mental health of infants in community settings. A qualitative descriptive study of 12 MCH nurses in Victoria, Australia, using semi-structured interviews, was thematically analysed. The data revealed that nurses used many skills to identify and manage attachment difficulties. Key among these were observations of interactions, collaboration with caregivers and reflective practice. Assessments and interventions are also influenced by nurses' emotions, attitudes and workplace factors. An unexpected finding was that attachment markers can be likened to an 'iceberg': warning indicators at the tip can be easily observed by the nurse, while the less obvious underlying factors need to be explored in order to support attachment and improve infant mental health outcomes. Education for nurses should include concepts of attachment and link behaviours with emotional wellbeing.
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30,000 Degrees: Steps toward the Formation of a Staten Island Higher Education Partnership
Fanuzzi, Robert; Gold, Kenneth; Seigel, Samantha; Cuccia, Christopher; Kress, Michael; Sanchez, Sandy
2015-01-01
In order to confront lower than average completion rates in New York City and to provide a strong economic and civic foundation for Staten Island, the borough's three institutions of higher education, College of Staten Island/City University of New York, St. John's University, and Wagner College, have brought together their high school and…
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Schneider, James C.; Kruse, Sarah E.
2003-12-01
The freshwater lens on small islands may easily be overexploited or polluted due to dense development combined with improper management. On small carbonate islands complexities in fresh groundwater distribution are most commonly driven by geologic heterogeneities and their attendant impact on permeability and effective recharge patterns. Siliciclastic islands (composed primarily of quartz sand and other silica-based minerals) have been less well studied, and fewer common patterns of lens development have emerged. On some siliciclastic islands correlations between geology and lens geometries are weak; on these islands the freshwater lens geometry may be largely determined by how vegetation and terrain elevation affect recharge. Other factors such as unequal sea level on opposite sides of an island and transient variability (natural island migration and climate variability) may also be locally significant. Two barrier islands in the northeast Gulf of Mexico fall into this category of siliciclastic islands. Relationships between lens morphology, geology, vegetation, terrain, and sea level and transient effects are documented on St George Island and Dog Island, FL. Patterns of fresh groundwater occurrence are deduced with electrical and electromagnetic geophysical methods. Although isolated cores show geologic layering that could potentially control freshwater lens development, ground penetrating radar and seismic surveys show no evidence of semi-continuous subhorizontal layering. Inferred lens thickness and geometry suggests that site geology plays a relatively minor role as a cause of complexity in lens formation. Lens geometry does appear to be related to terrain and vegetation variability, and further complicated by the continuous reforming of these islands by coastal processes and human development.
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Continents as lithological icebergs: The importance of buoyant lithospheric roots
Abbott, D.H.; Drury, R.; Mooney, W.D.
1997-01-01
An understanding of the formation of new continental crust provides an important guide to locating the oldest terrestrial rocks and minerals. We evaluated the crustal thicknesses of the thinnest stable continental crust and of an unsubductable oceanic plateau and used the resulting data to estimate the amount of mantle melting which produces permanent continental crust. The lithospheric mantle is sufficiently depleted to produce permanent buoyancy (i.e., the crust is unsubductable) at crustal thicknesses greater than 25-27 km. These unsubductable oceanic plateaus and hotspot island chains are important sources of new continental crust. The newest continental crust (e.g., the Ontong Java plateau) has a basaltic composition, not a granitic one. The observed structure and geochemistry of continents are the result of convergent margin magmatism and metamorphism which modify the nascent basaltic crust into a lowermost basaltic layer overlain by a more silicic upper crust. The definition of a continent should imply only that the lithosphere is unsubductable over ??? 0.25 Ga time periods. Therefore, the search for the oldest crustal rocks should include rocks from lower to mid-crustal levels.
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Effect of temperature in domestic refrigerators on fresh-cut Iceberg salad quality and waste.
Manzocco, L; Alongi, M; Lagazio, C; Sillani, S; Nicoli, M C
2017-12-01
The evolution of different quality parameters (firmness, weight loss, colour changes, microbial counts, consumer rejection) of packed fresh-cut Iceberg salad was assessed at 4, 8 and 12°C to simulate domestic refrigerators running at different conditions. The increase in storage temperature did not affect salad firmness and weight loss but increased colour changes, microbial growth and consumer rejection. A survey among Italian consumers was also carried out and demonstrated that fresh-cut salad was mainly consumed within the first 5days after purchasing. Consumer rejection data were combined with data relevant to the distribution of salad consumption over the days following product purchase, to estimate salad wasting risk. When salad was stored at 4 and 8°C, estimated wasted packages within the expiration date (7days) were sustainable interventions to tackle food waste. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Yagishita, Koji
1994-01-01
Diagenesis of sediments derived from a magmatic arc provenance may greatly differ from that of sediments derived from an intracratonic- or foreland-type provenance. Sediments from the magmatic arc are compositionally immature and rich in volcanic and sedimentary rock fragments. Sandstone samples of mid- to Upper Cretaceous formations in the Queen Charlotte Islands, British Columbia, Canada, contain either large amounts of pseudomatrix or authigenic cements. An inverse relationship between the...
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The 'positive' magnetic islands conception and its applications to T-11M experiments
International Nuclear Information System (INIS)
Mirnov, S.V.; Semenov, I.B.; Belov, A.M.; Azizov, E.A.
1999-01-01
A situation in tokamaks is analyzed in which the development of strong plasma current filamentation leads to nonlinear magnetic islands formation near resonant magnetic surfaces. It is shown that, along with the usual 'negative' magnetic islands, in which the modulation of the perturbation currents is negative, 'positive' islands can form in local regions with the positive current modulation. The 'positive' magnetic islands can be a reason of the 'hot spot' in plasma center during sawtooth crash. Also the 'positive' islands, probably, plays the important role in m=2 development during the major disruption and in the locked modes dynamics. (author)
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The ''positive'' magnetic islands conception and its applications to T-11M experiments
International Nuclear Information System (INIS)
Mirnov, S.V.; Semenov, I.; Belov, A.M.; Azizov, E.A.
2001-01-01
A situation in tokamaks is analyzed in which the development of strong plasma current filamentation leads to nonlinear magnetic islands formation near resonant magnetic surfaces. It is shown that, along with the usual ''negative'' magnetic islands, in which the modulation of the perturbation currents is negative, ''positive'' islands can form in local regions with the positive current modulation. The ''positive'' magnetic islands can be a reason of the ''hot spot'' in plasma center during sawtooth crash. Also the ''positive'' islands, probably, plays the important role in m=2 development during the major disruption and in the locked modes dynamics. (author)
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Analysis of Island Formation Due to RMPs in D3D Plasmas Using SIESTA
Hirshman, Steven; Shafer, Morgan; Seal, Sudip; Canik, John
2015-11-01
By varying the initial helical perturbation amplitude of Resonant Magnetic Perturbations (RMPs) applied to a Doublet III-D (DIII-D) plasma, a variety of meta-stable equilibrium are scanned using the SIESTA MHD equilibrium code. It is found that increasing the perturbation strength at the dominant m =2 resonant surface leads to lower MHD energies and significant increases in the equilibrium island widths at the m =2 (and sidebands) surfaces. Island overlap eventually leads to stochastic magnetic fields which correlate well with the experimentally inferred field line structure. The magnitude and spatial phase (around associated rational surfaces) of resonant (shielding) components of the parallel current is shown to be correlated with the magnetic island topology. Work supported by U.S. DOE under Contract DE-AC05-00OR22725 with UT-Battelle, LLC.
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Sota, Teiji; Nagata, Nobuaki
2008-10-27
The Japanese Islands have been largely isolated from the East Asian mainland since the Early Pleistocene, allowing the diversification of endemic lineages. Here, we explore speciation rates and historical biogeography of the ground beetles of the subgenus Ohomopterus (genus Carabus) based on nuclear and mitochondrial gene sequences. Ohomopterus diverged into 15 species during the Pleistocene. The speciation rate was 1.92 Ma(-1) and was particularly fast (2.37 Ma(-1)) in a group with highly divergent genitalia. Speciation occurred almost solely within Honshu, the largest island with complex geography. Species diversity is highest in central Honshu, where closely related species occur parapatrically and different-sized species co-occur. Range expansion of some species in the past has resulted in such species assemblages. Introgressive hybridization, at least for mitochondrial DNA, has occurred repeatedly between species in contact, but has not greatly disturbed species distinctness. Small-island populations of some species were separated from main-island populations only after the last glacial (or the last interglacial) period, indicating that island isolation had little role in speciation. Thus, the speciation and formation of the Ohomopterus assemblage occurred despite frequent opportunities for secondary contact and hybridization and the lack of persistent isolation. This radiation was achieved without substantial ecological differentiation, but with marked differentiation in mechanical agents of reproductive isolation (body size and genital morphology).
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Genomic islands of divergence are not affected by geography of speciation in sunflowers.
Renaut, S; Grassa, C J; Yeaman, S; Moyers, B T; Lai, Z; Kane, N C; Bowers, J E; Burke, J M; Rieseberg, L H
2013-01-01
Genomic studies of speciation often report the presence of highly differentiated genomic regions interspersed within a milieu of weakly diverged loci. The formation of these speciation islands is generally attributed to reduced inter-population gene flow near loci under divergent selection, but few studies have critically evaluated this hypothesis. Here, we report on transcriptome scans among four recently diverged pairs of sunflower (Helianthus) species that vary in the geographical context of speciation. We find that genetic divergence is lower in sympatric and parapatric comparisons, consistent with a role for gene flow in eroding neutral differences. However, genomic islands of divergence are numerous and small in all comparisons, and contrary to expectations, island number and size are not significantly affected by levels of interspecific gene flow. Rather, island formation is strongly associated with reduced recombination rates. Overall, our results indicate that the functional architecture of genomes plays a larger role in shaping genomic divergence than does the geography of speciation.
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Notes on the geochemical survey for uranium in Mindoro Island, Philippines
International Nuclear Information System (INIS)
Santos, G. Jr.; Fernandez, L.G.; Villamater, D.T.; Seguis, J.E.; Ibe, M.G.
1981-03-01
Geochemical reconnaisance using stream sediment and heavy-mineral concentrates panned from coarse alluvium has been carried out in Mindoro Island, one of the oldest and diverse geologic terrains in the Philippines. A total of 135 selected sampling points situated near accessible areas along the periphery of the island were sampled. The samples were collected at a density of one sample per 53 sq. km. A set minus 80 mesh stream sediment fraction and heavy-mineral concentrates was obtained from each sampling point. Mobile or extractable and total uranium were determined. A large uranium anomaly was delineated over the Carboniferous Mindoro Metamorphics as well as in areas underlain by Early Tertiary sedimentary formations. Another group of anomalies were outlined in the southern part of the island underlain by Jurassic Mansalay Formation and Early to Middle Tertiary sedimentary rocks with associated limestone and coal measures. (author)
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Shawler, J. L.; Seminack, C.; DeMarco, K. R.; Hein, C. J.; Petruny, L. M.
2017-12-01
Although generally retrogradational in nature, barrier islands commonly contain progradational segments which may preserve records of past coastal dynamics and environmental changes which affected their formation. In particular, recurved-spit ridges may record former shoreline positions on the surface, while in their stratigraphic architecture contain evidence of the processes influencing spit growth. This study uses topographic mapping and nearly 40 km of ground-penetrating radar (GPR) transects to investigate the pre-historic (ca. 1000-1850 C.E.) and historic elongation of Assateague Island, VA (USA) and affiliated progradation of Chincoteague Island. These data uncovered three previously unknown former tidal inlets which have no discernible surface signatures. GPR data further reveal southerly migration (up to 95 m) and closure of these tidal inlets. In addition, GPR data indicates the apparent overprinting of multiple inlets, suggesting later reoccupation of former channels. Seaward-dipping clinoforms (5-15°) indicate that, following inlet closure, the island widened and elongated through beach-ridge growth, proceeded by the development of aeolian foredune ridges. In particular, two large (5 m elevation, 150 m wide) ridges, bounded by smaller (1-3 m elevation, 20-50 m wide) ridge sets, comprise the relict recurved-spit of Assateague Island. This contrasts with the adjacent beach-ridge plain of Chincoteague Island, where surface morphology is characterized by more spatially uniform ridges (1-2 m high, 50-100 m wide). Thus, despite sharing similar internal structure as imaged in GPR, the formational processes associated with these two systems differ: the large, widely-spaced ridges of Assateague are likely indicative of punctuated progradation possibly associated with sediment pulses or complex inlet dynamics, whereas Chincoteague Island may have been built in a semi-protected environment through sediment delivered by inlet bypassing and local longshore
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Hofmann, Harald; Newborn, Dean; Cartwright, Ian
2017-04-01
Freshwater lenses underneath barrier islands are dynamic systems affected by changing sea levels and groundwater use. They are vulnerable to contamination and over-abstraction. Residence times of fresh groundwater in barrier islands are poorly understood and have mostly been assessed by modelling approaches and estimates without fundamental validation with geochronological data. Assessing residence time and recharge rates will improve significantly our understanding of hydrological processes of coastal environments that will in turn allow us to make informed decisions on groundwater use and environmental protection. This project focused on groundwater recharge rates and residence times of the fresh water aquifer system of North Stradbroke Island, south-east Queensland, Australia. Groundwater bores, wetlands and submarine groundwater discharge points in the tidal areas (wonky holes) were sampled along a transect across the island and were analysed for major ion chemistry and stable isotopes (δ2H, δ18O, δ13C) in combination with 3H and 14C analysis. Calculated 3H using a 95% exponential-piston flow model and 14C ages range from 12 to >100 years and modern to 3770 years, respectively, indicating a highly heterogeneous aquifer system with mixing from low and high conductive areas. The major ion chemistry in combination with stable and radiogenic isotopes suggests that a significant groundwater component derives from the fractured rock basement and older sedimentary formations underlying the sand dunes of the island. The results help refining the conceptual and numerical groundwater flow model for North Stradbroke island in this particular case but also demonstrate the possible complexity of barrier island hydrogeology.
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Geology, geochemistry and geochronology of Bora Bora island (Society islands, French Polynesia)
International Nuclear Information System (INIS)
Blais, S.; Guille, G.; Guillou, H.; Chauvel, C.; Maury, R.C.; Caroff, M.
2000-01-01
Bora Bora island, located at the northwestern edge of the Society archipelago represents the upper part of a shield volcano made up of a pile of meter-thick alkali basalt flows and rare hawaiites. The summit caldera (4.4 km in diameter) is still recognizable and a southwestern tilting of the volcanic edifice led to a relative uplift of the northern and eastern parts of the volcano. Bora Bora lavas derive from low partial melting degrees of an EMII mantle source the composition of which was influenced by continental materials. The sub-aerial volcanic activity corresponding to the presently emerged portion of the edifice took place between 3.45 and 3.10 Ma. Such ages are consistent with the formation of the island by being above the society hot spot considered as fixed and a Pacific plate motion of 11 cm.yr -1 . (authors)
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Ke, D; Saltveit, M E
1988-12-01
Russet spotting (RS) is a physiological disorder induced in iceberg lettuce (Lactuca sativa L.) by exposure to parts per million levels of ethylene at 5 +/- 2 degrees C. Ethylene induced phenylalanine ammonia-lyase and ionically bound peroxidase activities that correlated with development of RS symptoms. The ethylene-treated tissue had significantly higher lignin content than air control tissue with lignification localized in walls of RS-affected cells. Ethylene also caused the accumulation of the flavonoids (+)catechin and (-)epicatechin and the chlorogenic acid derivatives 3-caffeoyl-quinic acid, 3,5-dicaffeoylquinic acid, and 4,5-dicaffeoylquinic acid. These soluble phenolic compounds were readily oxidized to brown substances by polyphenol oxidase isolated from RS tissue. Ethylene substantially increased ionically bound indole-3-acetic acid (IAA) oxidase activity, while IAA application greatly reduced ethylene-induced phenylalanine ammonia-lyase, peroxidase, and IAA oxidase activities, soluble phenolic content, and RS development.
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National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the shelf and slope environments of Howland Atoll, Pacific Island Areas, Central Pacific. These...
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Eocene age of the Baranowski Glacier Group at Red Hill, King George Island, West Antarctica
Directory of Open Access Journals (Sweden)
Mozer Anna
2015-12-01
Full Text Available Radiometric and geochemical studies were carried out at Red Hill in the southern part of King George Island (South Shetland Islands, northern Antarctic Peninsula on the Bransfield Strait coast. The rock succession at Red Hill has been determined to represent the Baranowski Glacier Group that was previously assigned a Late Cretaceous age. Two formations were distinguished within this succession: the lower Llano Point Formation and the upper Zamek Formation. These formations have stratotypes defined further to the north on the western coast of Admiralty Bay. On Red Hill the Llano Point Formation consists of terrestrial lavas and pyroclastic breccia; the Zamek Formation consist predominantly of fine to coarse tuff, pyroclastic breccia, lavas, tuffaceous mud-, silt-, and sandstone, locally conglomeratic. The lower part of the Zamek Formation contains plant detritus (Nothofagus, dicotyledonous, thermophilous ferns and numerous coal seams (vitrinitic composition that confirm the abundance of vegetation on stratovolcanic slopes and surrounding lowlands at that time. Selected basic to intermediate igneous rocks from the succession have been analysed for the whole-rock K-Ar age determination. The obtained results indicate that the Red Hill succession was formed in two stages: (1 from about 51–50 Ma; and (2 46–42 Ma, i.e. during the Early to Middle Eocene. This, in combination with other data obtained from other Baranowski Glacier Group exposures on western coast of Admiralty Bay, confirms the recently defined position of the volcano-clastic succession in the stratigraphic scheme of King George Island. The new stratigraphic position and lithofacies development of the Red Hill succession strongly suggest its correlation with other Eocene formations containing fossil plants and coal seams that commonly occur on King George Island.
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Genomic island excisions in Bordetella petrii
Directory of Open Access Journals (Sweden)
Levillain Erwan
2009-07-01
Full Text Available Abstract Background Among the members of the genus Bordetella B. petrii is unique, since it is the only species isolated from the environment, while the pathogenic Bordetellae are obligately associated with host organisms. Another feature distinguishing B. petrii from the other sequenced Bordetellae is the presence of a large number of mobile genetic elements including several large genomic regions with typical characteristics of genomic islands collectively known as integrative and conjugative elements (ICEs. These elements mainly encode accessory metabolic factors enabling this bacterium to grow on a large repertoire of aromatic compounds. Results During in vitro culture of Bordetella petrii colony variants appear frequently. We show that this variability can be attributed to the presence of a large number of metastable mobile genetic elements on its chromosome. In fact, the genome sequence of B. petrii revealed the presence of at least seven large genomic islands mostly encoding accessory metabolic functions involved in the degradation of aromatic compounds and detoxification of heavy metals. Four of these islands (termed GI1 to GI3 and GI6 are highly related to ICEclc of Pseudomonas knackmussii sp. strain B13. Here we present first data about the molecular characterization of these islands. We defined the exact borders of each island and we show that during standard culture of the bacteria these islands get excised from the chromosome. For all but one of these islands (GI5 we could detect circular intermediates. For the clc-like elements GI1 to GI3 of B. petrii we provide evidence that tandem insertion of these islands which all encode highly related integrases and attachment sites may also lead to incorporation of genomic DNA which originally was not part of the island and to the formation of huge composite islands. By integration of a tetracycline resistance cassette into GI3 we found this island to be rather unstable and to be lost from
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Deposition of phospholipid layers on SiO{sub 2} surface modified by alkyl-SAM islands
Energy Technology Data Exchange (ETDEWEB)
Tero, R.; Takizawa, M.; Li, Y.J.; Yamazaki, M.; Urisu, T
2004-11-15
Formation of the supported planar bilayer of dipalmitoylphosphatidylcholine (DPPC) on SiO{sub 2} surfaces modified with the self-assembled monolayer (SAM) of octadecyltrichlorosilane (OTS) has been investigated by atomic force microscopy (AFM). DPPC was deposited by the fusion of vesicles on SiO{sub 2} surfaces with OTS-SAM islands of different sizes and densities. The DPPC bilayer membrane formed self-organizingly on the SiO{sub 2} surface with small and sparse OTS islands, while did not when the OTS islands were larger and denser. The relative size between the vesicles and the SiO{sub 2} regions is the critical factor for the formation of the DPPC bilayer membrane.
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Guy, Kristy K.; Plant, Nathaniel G.
2014-01-01
This Data Series Report contains lidar elevation data collected on July 12 and 14, 2013, for Dauphin Island, Alabama, and Chandeleur, Stake, Grand Gosier and Breton Islands, Louisiana. Classified point cloud data—data points described in three dimensions—in lidar data exchange format (LAS) and bare earth digital elevation models (DEMs) in ERDAS Imagine raster format (IMG) are available as downloadable files. Photo Science, Inc., was contracted by the U.S. Geological Survey (USGS) to collect and process these data. The lidar data were acquired at a horizontal spacing (or nominal pulse spacing) of 1 meter (m) or less. The USGS surveyed points within the project area from July 14–23, 2013, for use in ground control and accuracy assessment. Photo Science, Inc., calculated a vertical root mean square error (RMSEz) of 0.012 m by comparing 10 surveyed points to an interpolated elevation surface of unclassified lidar data. The USGS also checked the data using 80 surveyed points and unclassified lidar point elevation data and found an RMSEz of 0.073 m. The project specified an RMSEz of 0.0925 m or less. The lidar survey was acquired to document the short- and long-term changes of several different barrier island systems. Specifically, this survey supports detailed studies of Chandeleur and Dauphin Islands that resolve annual changes in beaches, berms and dunes associated with processes driven by storms, sea-level rise, and even human restoration activities. These lidar data are available to Federal, State and local governments, emergency-response officials, resource managers, and the general public.
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Birth of two volcanic islands in the southern Red Sea
Xu, Wenbin
2015-05-26
Submarine eruptions that lead to the formation of new volcanic islands are rare and far from being fully understood; only a few such eruptions have been witnessed since Surtsey Island emerged to the south of Iceland in the 1960s. Here we report on two new volcanic islands that were formed in the Zubair archipelago of the southern Red Sea in 2011–2013. Using high-resolution optical satellite images, we find that the new islands grew rapidly during their initial eruptive phases and that coastal erosion significantly modified their shapes within months. Satellite radar data indicate that two north–south-oriented dykes, much longer than the small islands might suggest, fed the eruptions. These events occurred contemporaneously with several local earthquake swarms of the type that typically accompany magma intrusions. Earthquake activity has been affecting the southern Red Sea for decades, suggesting the presence of a magmatically active zone that has previously escaped notice.
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Ridge interaction features of the Line Islands
Konter, J. G.; Koppers, A. A. P.; Storm, L. P.
2016-12-01
The sections of Pacific absolute plate motion history that precede the Hawaii-Emperor and Louisville chains are based on three chains: the Line Islands-Mid-Pacific Mountains, the Hess Rise-Shatsky Rise, and the Marshall Islands-Wake Islands (Rurutu hotspot). Although it has been clear that the Line Islands do not define a simple age progression (e.g. Schlanger et al., 1984), the apparent similarity to the Emperor Seamount geographic trend has been used to extend the overall Hawaii-Emperor track further into the past. However, we show here that plate tectonic reconstructions suggest that the Mid-Pacific Mountains (MPMs) and Line Islands (LIs) were erupted near a mid-ocean ridge, and thus these structures do not reflect absolute plate motion. Moverover, the morphology and geochemistry of the volcanoes show similarities with Pukapuka Ridge (e.g. Davis et al., 2002) and the Rano Rahi seamounts, presumed to have a shallow origin. Modern 40Ar/39Ar ages show that the LIs erupted at various times along the entire volcanic chain. The oldest structures formed within 10 Ma of plate formation. Given the short distance to the ridge system, large aseismic volcanic ridges, such as Necker Ridge and Horizon Guyot may simply reflect a connection between MPMs and the ridge, similar to the Pukapuka Ridge. The Line Islands to the south (including Karin Ridge) define short subchains of elongated seamounts that are widespread, resembling the Rano Rahi seamount field. During this time, the plate moved nearly parallel to the ridge system. The change from few large ridges to many subchains may reflect a change in absolute plate motion, similar to the Rano Rahi field. Here, significant MPMs volcanism is no longer connected to the ridge along plate motion. Similar to Pukapuka vs. Rano Rahi, the difference in direction between plate motion and the closest ridge determines whether larger ridges or smaller seamount subchains are formed. The difference between the largest structures (MPMs and LIs
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Xiao, W.; Wang, R.; Zhang, T.; Duan, X.; Polyak, L.
2017-12-01
In the Pleistocene the western Arctic Ocean was affected by deglacial discharge events from ice sheets in northern North America as well as the East Siberian and Chukchi margins. Distribution of Ice Rafted Debris (IRD) >250 μm and planktonic foraminiferal N. pachyderma (sin.) (Nps) δ18O and δ13C was compared in CHINARE sediment cores ARC2-M03 (Wang et al., 2013) and ARC3-P37 from the Chukchi Abyssal Plain and Northwind Ridge, respectively, to identify the impacts of icebergs and meltwater on paleoceanographic environments since MIS 5. The IRD is mainly composed of quartz grains and fragments of clastic rocks and detrital carbonates. The carbonates, mostly dolomites characteristic of the Canadian Arctic Archipelago (CAA) provenance, typically anti-correlate with quartz and clastic rocks, indicating different sources such as Chukchi-Alaskan or East Siberian margin. Most of the Nps δ18O depletions correspond to peaks in detrital carbonates, suggesting a strong influence of meltwater from the Laurentide Ice Sheet (LIS) on the western Arctic Ocean. A conspicuous dark gray interval interpreted to represent glacial/deglacial environments of MIS 4/3 age, shows a remarkable depletion in Nps δ13C along with high δ18O values and absence of IRD. This unusual signature may be related to a persistent sea-ice cover and/or high fluxes of terrigenous material with deglacial debris flows. In a younger grey interval corresponding to MIS2, high abundances of quartz and clastic rocks in the Northwind Ridge core ARC3-P37 indicate iceberg discharge from areas other than CAA, such as the Mackenzie LIS lobe or Chukchi-Alaskan margin. The MIS2-Holocene transition is marked by an increase in detrital carbonates co-occurring with Nps δ13C and δ18O depletion (Polyak et al., 2007), indicative of LIS iceberg/meltwater fluxes from the CAA. We note that stable-isotope events in the study area may go unnoticed because of gaps in foraminiferal records related to dissolution and/or adverse
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Lesvos Island UNESCO Global Geopark, Greece : Systems Thinking on Sustainable Value
Kumar, Satish
2016-01-01
The study is an original research suggesting Lesvos Island UNESCO Global Geopark as a platform for systems thinking on sustainable value. The study provides information on Global Geoparks Network, European Geoparks Network and detailed description of Lesvos Island UNESCO Global Geopark emphasizing its distinct features. The formation of Lesvos landscape during the Miocene period due to volcanic eruptions, creation of petrified forests, geological faults and geosites coupled with natural, cult...
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Energy Technology Data Exchange (ETDEWEB)
Ojima, T.; Murakami, S. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science; Mitsumoto, K. [Waseda University, Tokyo (Japan). School of Science and Engineering
1997-10-01
Study is conducted of the effect of change in land use and increase in artificial exhaust heat on heat island formation in Shanghai. Concerning the land use distribution in Shanghai, a point sampling survey was conducted in the 1930s using topographic charts, when the area was broken down into building-occupied region, paddy field, bare ground, and waters. In the 1990s, thanks to data from satellites, high-density and low-density urban regions have added. Calculation for Shanghai is performed, based on the rate of increase in Tokyo`s population and data predicted for Shanghai`s population, on the assumption that Shanghai`s population in the 2050s will grow 2.3 times larger than it is in the 1990s. The prediction thus produced indicates that the urban area in Shanghai in the 2050s will be as large as that of the present-day Tokyo that covers a 50km zone. Heat island formation prediction for Shanghai is worked out using computational fluid dynamics (CFD)-aided simulation. According to the prediction, while the maximum temperature in the 1930s was 29.6degC or 4degC higher than in the suburbs, it is 33.2degC or 7.6deg higher in the 1990s, and will be 34.4degC or 8.6degC higher in the 2050s. 16 refs., 11 figs., 1 tab.
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Triangle islands and cavities on the surface of evaporated Cu(In, Ga)Se2 absorber layer
International Nuclear Information System (INIS)
Han Anjun; Zhang Yi; Liu Wei; Li Boyan; Sun Yun
2012-01-01
Highlights: ► Lots of uncommon triangle islands and cavities are found on (1 1 2) planes terminated by Se atoms of evaporated Cu(In, Ga)Se 2 thin films. ► Se ad-dimer as a nucleus, Cu atom diffusion from Cu(In, Ga)Se 2 grains brings the epitaxial triangle island. ► The triangle islands grow with a two-dimensional layered mode. ► The triangle cavities are formed due to the insufficient coalescence of triangle islands. ► The performance of solar cell without triangle islands is improved. - Abstract: Cu(In, Ga)Se 2 (CIGS) thin films are co-evaporated at a constant substrate temperature of 500 °C on the Mo/soda lime glass substrates. The structural properties and chemical composition of the CIGS films are studied by an X-ray diffractometer (XRD) and an X-ray fluorescent spectrometer (XRF), respectively. A scanning electron microscope (SEM) is used to study the surface morphology. Lots of uncommon triangle islands and cavities are found on some planes of the CIGS thin films. We investigate the formation mechanism of these triangle islands. It is found that the planes with the triangle islands are (1 1 2) planes terminated by Se atoms. Se ad-dimer as a nucleus, Cu diffusion from CIGS grains brings the epitaxial triangle islands which grow with a two-dimensional layered mode. The film with Cu/(Ga + In) = 0.94–0.98 is one key of the formation of these islands. The triangle cavities are formed due to the insufficient coalescence of triangle islands. The growth of triangle islands brings a compact surface with large layered grains and many jagged edges, but no triangle cavity. Finally, we compare the performance of solar cell with triangle islands and layered gains. It is found that the performance of solar cell with large layered gains is improved.
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77 FR 41168 - Marine Mammals; Subsistence Taking of Northern Fur Seals; St. Paul Island
2012-07-12
... Administrative Procedure Act (APA). The Pribilof Island Community of St. Paul Island, Aleut Community of St. Paul... comment on from the resulting list and click on the ``Submit a Comment'' icon on the right of that line... Adobe PDF file formats only. Information related to the request for rulemaking is available on the...
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Island universes structure and evolution of disk galaxies
DE JONG, R. S
2007-01-01
This book contains an up-to-date review of the structure and evolution of disk galaxies from both the observational and theoretical point of view. The book is the proceedings of the "Island Universes" conference held at the island of Terschelling, The Netherlands in July 2005, which attracted about 130 experts and students in the field. The conference was organized as a tribute to Dr. Piet C. van der Kruit for receiving the honorary Jacobus C. Kapteyn Professorship in Astronomy. The eight topical themes discussed at the meeting are reflected in these proceedings: 1) Properties of Stellar Disks, 2) Kinematics and Dynamics of Disk Galaxies, 3) Bars, Spiral Structure, and Secular Evolution in Disk Galaxies, 4) The Outskirts and Environment of Disk Galaxies, 5) Interstellar Matter, 6) (Evolution of) Star Formation in Galactic Disks, 7) Disk Galaxies through Cosmic Time, and 8) Formation Models of Disk Galaxies. These proceedings are concluded with a conference summary reflecting on the most significant recent pro...
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EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.
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Lu, Haixia; Zhu, Junli; Li, Jianrong; Chen, Jinru
2015-06-01
Contaminated leafy green vegetables have been linked to several outbreaks of human gastrointestinal infections. Antimicrobial interventions that are adoptable by the fresh produce industry for control of pathogen contamination are in great demand. This study was undertaken to evaluate the efficacy of sustained active packaging on control of Escherichia coli O157:H7 and total aerobic bacteria on lettuce. Commercial Iceberg lettuce was inoculated with a 3-strain mixture of E. coli O157:H7 at 10(2) or 10(4) CFU/g. The contaminated lettuce and un-inoculated controls were placed respectively in 5 different active packaging structures. Traditional, nonactive packaging structure was included as controls. Packaged lettuce was stored at 4, 10, or 22 °C for 3 wk and sampled weekly for the population of E. coli O157:H7 and total aerobic bacteria. Results showed that packaging structures with ClO2 generator, CO2 generator, or one of the O2 scavengers effectively controlled the growth of E. coli O157:H7 and total aerobic bacteria under all storage conditions. Packaging structure with the ClO2 generator was most effective and no E. coli O157:H7 was detected in samples packaged in this structure except for those that were inoculated with 4 log CFU/g of E. coli O157:H7 and stored at 22 °C. Packaging structures with an oxygen scavenger and the allyl isothiocyanate generator were mostly ineffective in control of the growth of the bacteria on Iceberg lettuce. The research suggests that some of the packaging structures evaluated in the study can be used to control the presence of foodborne pathogens on leafy green vegetables. © 2015 Institute of Food Technologists®
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International Nuclear Information System (INIS)
Tarik Ogurtani, Omer; Celik, Aytac; Emre Oren, Ersin
2014-01-01
Quantum dots (QD) have discrete energy spectrum, which can be adjusted over a wide range by tuning composition, density, size, lattice strain, and morphology. These features make quantum dots attractive for the design and fabrication of novel electronic, magnetic and photonic devices and other functional materials used in cutting-edge applications. The formation of QD on epitaxially strained thin film surfaces, known as Stranski-Krastanow (SK) islands, has attracted great attention due to their unique electronic properties. Here, we present a systematic dynamical simulation study for the spontaneous evolution of the SK islands on the stochastically rough surfaces (nucleationless growth). During the development of SK islands through the mass accumulation at randomly selected regions of the film via surface drift-diffusion (induced by the capillary and mismatch stresses) with and/or without growth, one also observes the formation of an extremely thin wetting layer having a thickness of a few Angstroms. Above a certain threshold level of the mismatch strain and/or the size of the patch, the formation of multiple islands separated by shallow wetting layers is also observed as metastable states such as doublets even multiplets. These islands are converted into a distinct SK islands after long annealing times by coalescence through the long range surface diffusion. Extensive computer simulation studies demonstrated that after an initial transient regime, there is a strong quadratic relationship between the height of the SK singlet and the intensity of the lattice mismatch strain (in a wide range of stresses up to 8.5 GPa for germanium thin crystalline films), with the exception at those critical points where the morphological (shape change with necking) transition takes place.
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Crystalline islands of semiconductor films
International Nuclear Information System (INIS)
Zmievskaya, G. I.; Bondareva, A. L.
2011-01-01
Silicon carbide (SiC) nucleation in the form of powder in a discharge plasma and the formation of thin film islands on a Si(100) substrate in the course of gas-phase epitaxy are simulated numerically. Models of plasma-like media and nonequilibrium processes accompanying phase transitions of the first kind (such as condensation and crystallization) in the initial fast (fluctuation) stage are described. The nonstationary evolution of nuclei size distribution functions is modeled by solving kinetic equations in partial derivatives and stochastic Ito-Stratonovich analog equations. This makes it possible to refine the formation mechanisms of microcrystalline state polytypes and calculate the nucleation rate and the initial roughness of a SiC coating.
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DEFF Research Database (Denmark)
Whittaker, Robert James; Fernández-Palacios, José María; Matthews, Thomas J.
2017-01-01
Islands provide classic model biological systems. We review how growing appreciation of geoenvironmental dynamics of marine islands has led to advances in island biogeographic theory accommodating both evolutionary and ecological phenomena. Recognition of distinct island geodynamics permits gener...
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Tenarife Island, Canary Island Archipelago, Atlantic Ocean
1991-01-01
Tenarife Island is one of the most volcanically active of the Canary Island archipelago, Atlantic Ocean, just off the NW coast of Africa, (28.5N, 16.5W). The old central caldera, nearly filled in by successive volcanic activity culminating in two stratocones. From those two peaks, a line of smaller cinder cones extend to the point of the island. Extensive gullies dissect the west side of the island and some forests still remain on the east side.
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CRED 20m Gridded bathymetry of Nihoa Island, Hawaii, USA (Arc ASCII format)
National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry (20m) of the shelf and slope environments of Nihoa Island, Hawaii, USA. The ASCII includes multibeam bathymetry from the Simrad EM120, Simrad...
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Assessing the origin of unusual organic formations in lava caves from Canary Islands (Spain)
Miller, Ana Z.; de la Rosa, Jose M.; Garcia-Sanchez, Angela M.; Pereira, Manuel F. C.; Jurado, Valme; Fernández, Octavio; Knicker, Heike; Saiz-Jimenez, Cesareo
2016-04-01
Lava tubes, like other caves, contain a variety of speleothems formed in the initial stage of a lava tube formation or due to leaching and subsequent precipitation of secondary minerals. Primary and secondary mineral formations in lava caves are mainly composed of silicate minerals, although secondary minerals common in limestone caves have been also reported in this type of caves. In addition, unusual colored deposits have been found on the walls and ceilings of lava tubes, some of them of unknown origin and composition. A brown to black-colored mud-like deposits was observed in "Llano de los Caños" Cave, La Palma Island, Canary Islands, Spain. These black deposits coat the wall and ceiling of the lava tube where sub-horizontal fractures occur. FESEM-EDS, X-ray micro-computed tomography and mineralogical analyses were conducted for morphological, 3D microstructural and compositional characterization of these unusual speleothem samples. These techniques revealed that they are mainly composed of amorphous materials, suggesting an organic carbon composition. Hence, analytical pyrolysis (Py-GC/MS), solid-state 13C Nuclear Magnetic Resonance (NMR) and stable isotope analysis were applied to assess the nature and origin of the black deposits. The combination of these analytical tools permits the identification of specific biomarkers (di- and triterpenoids) for tracing the potential sources of the organic compounds in the speleothems. For comparison purposes, samples from the topsoil and overlaying vegetation were also analyzed. Chromatograms resulting from the Py-GC/MS showed an abundance of polysaccharides, lipids and terpenoids typically derived from the vegetation of the area (Erica arborea). In addition, levoglucosan, polycyclic aromatic hydrocarbons and N-containing heterocyclic compounds were detected. They probably derived from the leaching of charred vegetation resulting from a wildfire occurred in the area in 2012. The lack of the typical pattern of odd
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Origin of three-armed rifts in volcanic islands: the case of El Hierro (Canary Islands)
Galindo Jiménez, Inés; Becerril Carretero, Laura; Martí Molist, Joan; Gudmundsson, Agust
2015-04-01
to the formation of mega-landslides and mask the general radial pattern. Thus, the rift zones on El Hierro are shallow structures that commonly capture and divert ascending magma towards different parts of the island but do not condition magma ascent at depth.
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International Nuclear Information System (INIS)
Shklyaev, A.A.; Budazhapova, A.E.
2016-01-01
Graphical abstract: - Highlights: • Solid source MBE is used for island growth by Ge deposition on Si(1 0 0) at 700–900 °C. • Islands acquire a monomodal size distribution at temperatures above 800 °C. • Islands form ordered arrays during Ge deposition at 900 °C. • Conditions close to dynamic equilibrium are realized for growth and decay of islands at 900 °C. • Shape of ordered islands is cone with shallow sidewalls. - Abstract: 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°.
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Pliocene-Quaternary history of Futuna island, south Vanuatu, southwest Pacific
International Nuclear Information System (INIS)
Neef, G.; McCulloch, M.T.
2001-01-01
Uranium-series ages from thermal ionisation mass spectrometry are reported here for the raised coral reefs of Futuna Island, which lies adjacent to the eastern margin of the backarc Futuna Trough in south Vanuatu, southwest Pacific. U-series ages from coral from the lowest raised reef indicate that its upper part is most likely to be ca 210 ka, whereas the most elevated raised reef has a likely age of ca 520 ka (range 600-440 ka). The inferred Pliocene-Quaternary history for Futuna Island and the adjacent Futuna Trough is: (i) formation of the Pliocene - Early Quaternary basaltic-andesite cone in a southeast part of the Vanuatu Island Arc; (ii) inception of the Futuna Trough (adjacent to the west margin of Futuna Island) since 1.8Ma; (iii) subsequent uplift of the volcanic cone above sea-level caused ∼ 500 m of its upper part to be removed by marine erosion; (iv) the island then subsided and at least 160 m of limestone was deposited on the truncated cone; and (v) during the period 520 ka to ca 210 ka seven fringing reefs formed at the margin of the cone as the island was uplifted. Since ca 210 ka Futuna further subsided and, as a result, the post ca 210 ka history of the island is obscure. Copyright (2001) Geological Society of Australia
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Mass wasting and subaerial weathering in guyot formation: the Hawaiian and Canary Ridges as examples
Christian Smoot, N.
1995-10-01
By using a combination of bathymetry and topography in the computerized GRASS 3D package, guyot evolution has been determined on the fast-moving Pacific plate for the subaerial, low sloped Hawaiian Island chain. On the slow-moving African plate, the timing of guyot formation has been determined for the subaerial, steeper sloped Canary Islands chain. In the Hawaiian chain, the Niihau Island platform was already essentially formed, although there is a platform at the 180 m elevation on Kauai Island if the remaining peaks are discounted. By Fuerteventura Island in the Canary chain the seamount/island has already been flattened. Both of these platforms are far above the influence of wave cutting. The causal agent of flattening is primarily mass wasting by landsliding, caused in part by earthquake activity on the moving plates. This disproves the subsidence and wavecut theory of guyot formational processes in that the guyot is already formed before it subsides. The islands lie in the tropical coral zone, yet coral formation has little effect on the flattening process. This may be because the turbidity from slumps kills the coral. This exercise also gives a time limit for the reduction of pristine volcanic slopes to the typical guyot surface, that time being between one and four million years. It is apparent that wave cutting merely polishes the stone, applying the finishing patina.
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The tad locus: postcards from the widespread colonization island.
Tomich, Mladen; Planet, Paul J; Figurski, David H
2007-05-01
The Tad (tight adherence) macromolecular transport system, which is present in many bacterial and archaeal species, represents an ancient and major new subtype of type II secretion. The tad genes are present on a genomic island named the widespread colonization island (WCI), and encode the machinery that is required for the assembly of adhesive Flp (fimbrial low-molecular-weight protein) pili. The tad genes are essential for biofilm formation, colonization and pathogenesis in the genera Aggregatibacter (Actinobacillus), Haemophilus, Pasteurella, Pseudomonas, Yersinia, Caulobacter and perhaps others. Here we review the structure, function and evolution of the Tad secretion system.
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Magnetic-Island Contraction and Particle Acceleration in Simulated Eruptive Solar Flares
Guidoni, S. E.; Devore, C. R.; Karpen, J. T.; Lynch, B. J.
2016-01-01
The mechanism that accelerates particles to the energies required to produce the observed high-energy impulsive emission in solar flares is not well understood. Drake et al. proposed a mechanism for accelerating electrons in contracting magnetic islands formed by kinetic reconnection in multi-layered current sheets (CSs). We apply these ideas to sunward-moving flux ropes (2.5D magnetic islands) formed during fast reconnection in a simulated eruptive flare. A simple analytic model is used to calculate the energy gain of particles orbiting the field lines of the contracting magnetic islands in our ultrahigh-resolution 2.5D numerical simulation. We find that the estimated energy gains in a single island range up to a factor of five. This is higher than that found by Drake et al. for islands in the terrestrial magnetosphere and at the heliopause, due to strong plasma compression that occurs at the flare CS. In order to increase their energy by two orders of magnitude and plausibly account for the observed high-energy flare emission, the electrons must visit multiple contracting islands. This mechanism should produce sporadic emission because island formation is intermittent. Moreover, a large number of particles could be accelerated in each magneto hydro dynamic-scale island, which may explain the inferred rates of energetic-electron production in flares. We conclude that island contraction in the flare CS is a promising candidate for electron acceleration in solar eruptions.
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Geology and geothermics of the Island of Milos (Greece)
Energy Technology Data Exchange (ETDEWEB)
Fytikas, M.; Marinelli, G.
1976-01-01
Geothermal research which has been conducted on the island of Milos is reviewed and the island's geology is discussed in terms of the geodynamics of the eastern Mediterranean. The rock formations which outcrop at Milos are described in detail, including the crystalline basement, Neogene transgressive conglomerates and limestones, and the Quaternary volcanics and volcano-sedimentary series. The recent disjunctive tectonics and volcano-tectonics affecting Milos and the neighboring islands are reviewed. Thermal manifestations and their attendant mineralizations and hydrothermal alterations are described. The geophysical methods utilized in exploration and for the siting of production wells are described. Exploration work involved the drilling of 55 wells for thermometric determinations and a full scale electrical survey. Preliminary data from two production wells with bottom-hole temperatures in excess of 300/sup 0/C are reported. Fifty-four references are provided.
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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.
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Estoque, Ronald C.; Murayama, Yuji
2017-11-01
Since it was first described about two centuries ago and due to its adverse impacts on urban ecological environment and the overall livability of cities, the urban heat island (UHI) phenomenon has been, and still is, an important research topic across various fields of study. However, UHI studies on cities in mountain regions are still lacking. This study aims to contribute to this endeavor by monitoring and examining the formation of surface UHI (SUHI) in a tropical mountain city of Southeast Asia -Baguio City, the summer capital of the Philippines- using Landsat data (1987-2015). Based on mean surface temperature difference between impervious surface (IS) and green space (GS1), SUHI intensity (SUHII) in the study area increased from 2.7 °C in 1987 to 3.4 °C in 2015. Between an urban zone (>86% impervious) and a rural zone (<10% impervious) along the urban-rural gradient, it increased from 4.0 °C in 1987 to 8.2 °C in 2015. These results are consistent with the rapid urbanization of the area over the same period, which resulted in a rapid expansion of impervious surfaces and substantial loss of green spaces. Together with landscape composition variables (e.g. fraction of IS), topographic variables (e.g. hillshade) can help explain a significant amount of spatial variations in surface temperature in the area (R2 = 0.56-0.85) (p < 0.001). The relative importance of the 'fraction of IS' variable also increased, indicating that its unique explanatory and predictive power concerning the spatial variations of surface temperature increases as the city size becomes bigger and SUHI gets more intense. Overall, these results indicate that the cool temperature of the study area being situated in a mountain region did not hinder the formation of SUHI. Thus, the formation and effects of UHIs, including possible mitigation and adaptation measures, should be considered in landscape planning for the sustainable urban development of the area.
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Energy Technology Data Exchange (ETDEWEB)
Roczen, Maurizio; Malguth, Enno; Barthel, Thomas; Gref, Orman; Toefflinger, Jan A.; Schoepke, Andreas; Schmidt, Manfred; Ruske, Florian; Korte, Lars; Rech, Bernd [Institute for Silicon Photovoltaics, Helmholtz-Zentrum Berlin, Berlin (Germany); Schade, Martin; Leipner, Hartmut S. [Martin-Luther-Universitaet Halle-Wittenberg, Interdisziplinaeres Zentrum fuer Materialwissenschaften, Halle (Germany); Callsen, Gordon; Hoffmann, Axel [Technische Universitaet Berlin, Institut fuer Festkoerperphysik, Berlin (Germany); Phillips, Matthew R. [University of Technology Sydney, Department of Physics and Advanced Materials, NSW (Australia)
2012-09-15
The self-organized growth of crystalline silicon nanodots and their structural characteristics are investigated. For the nanodot synthesis, thin amorphous silicon (a-Si) layers with different thicknesses have been deposited onto the ultrathin (2 nm) oxidized (111) surface of Si wafers by electron beam evaporation under ultrahigh vacuum conditions. The solid phase crystallization of the initial layer is induced by a subsequent in situ annealing step at 700 C, which leads to the dewetting of the initial a-Si layer. This process results in the self-organized formation of highly crystalline Si nanodot islands. Scanning electron microscopy confirms that size, shape, and planar distribution of the nanodots depend on the thickness of the initial a-Si layer. Cross-sectional investigations reveal a single-crystalline structure of the nanodots. This characteristic is observed as long as the thickness of the initial a-Si layer remains under a certain threshold triggering coalescence. The underlying ultra-thin oxide is not structurally affected by the dewetting process. Furthermore, a method for the fabrication of close-packed stacks of nanodots is presented, in which each nanodot is covered by a 2 nm thick SiO{sub 2} shell. The chemical composition of these ensembles exhibits an abrupt Si/SiO{sub 2} interface with a low amount of suboxides. A minority charge carrier lifetime of 18 {mu}s inside of the nanodots is determined. (orig.)
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Multidecadal shoreline changes of atoll islands in the Marshall Islands
Ford, M.
2012-12-01
Atoll islands are considered highly vulnerable to the impacts of continued sea level rise. One of the most commonly predicted outcomes of continued sea level rise is widespread and chronic shoreline erosion. Despite the widespread implications of predicted erosion, the decadal scale changes of atoll island shorelines are poorly resolved. The Marshall Islands is one of only four countries where the majority of inhabited land is comprised of reef and atoll islands. Consisting of 29 atolls and 5 mid-ocean reef islands, the Marshall Islands are considered highly vulnerable to the impacts of sea level rise. A detailed analysis of shoreline change on over 300 islands on 10 atolls was undertaken using historic aerial photos (1945-1978) and modern high resolution satellite imagery (2004-2012). Results highlight the complex and dynamic nature of atoll islands, with significant shifts in shoreline position observed over the period of analysis. Results suggest shoreline accretion is the dominant mode of change on the islands studied, often associated with a net increase in vegetated island area. However, considerable inter- and intra-atoll variability exists with regards to shoreline stability. Findings are discussed with respect to island morphodynamics and potential hazard mitigation and planning responses within atoll settings.
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Sever, G.; Collis, S. M.; Ghate, V. P.
2017-12-01
Three-dimensional numerical experiments are performed to explore the mechanical and thermal impacts of Graciosa Island on the sampling of oceanic airflow and cloud evolution. Ideal and real configurations of flow and terrain are planned using high-resolution, large-eddy resolving (e.g., Δ cold-pool formation upstream of an ideal two-kilometer island, with von Kármán like vortices propagation downstream. Although the peak height of Graciosa is less than half kilometer, the Azores island chain has a mountain over 2 km, which may be leading to more complex flow patterns when simulations are extended to a larger domain. Preliminary idealized low-resolution moist simulations indicate that the cloud field is impacted due to the presence of the island. Longer simulations that are performed to capture diurnal evolution of island boundary layer show distinct land/sea breeze formations under quiescent flow conditions. Further numerical experiments are planned to extend moist simulations to include realistic atmospheric profiles and observations of surface fluxes coupled with radiative effects. This work is intended to produce a useful simulation framework coupled with instruments to guide airborne and ground sampling strategies during the ACE-ENA field campaign which is aimed to better characterize marine boundary layer clouds.
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Karl, Susan M.; Layer, Paul W.; Harris, Anita G.; Haeussler, Peter J.; Murchey, Benita L.
2011-01-01
The Cannery Formation consists of green, red, and gray ribbon chert, siliceous siltstone, graywacke-chert turbidites, and volcaniclastic sandstone. Because it contains early Permian fossils at and near its type area in Cannery Cove, on Admiralty Island in southeastern Alaska, the formation was originally defined as a Permian stratigraphic unit. Similar rocks exposed in Windfall Harbor on Admiralty Island contain early Permian bryozoans and brachiopods, as well as Mississippian through Permian radiolarians. Black and green bedded chert with subordinate lenses of limestone, basalt, and graywacke near Kake on Kupreanof Island was initially correlated with the Cannery Formation on the basis of similar lithology but was later determined to contain Late Devonian conodonts. Permian conglomerate in Keku Strait contains chert cobbles inferred to be derived from the Cannery Formation that yielded Devonian and Mississippian radiolarians. On the basis of fossils recovered from a limestone lens near Kake and chert cobbles in the Keku Strait area, the age of the Cannery Formation was revised to Devonian and Mississippian, but this revision excludes rocks in the type locality, in addition to excluding bedded chert on Kupreanof Island east of Kake that contains radiolarians of Late Pennsylvanian and early Permian age. The black chert near Kake that yielded Late Devonian conodonts is nearly contemporaneous with black chert interbedded with limestone that also contains Late Devonian conodonts in the Saginaw Bay Formation on Kuiu Island. The chert cobbles in the conglomerate in Keku Strait may be derived from either the Cannery Formation or the Saginaw Bay Formation and need not restrict the age of the Cannery Formation, regardless of their source. The minimum age of the Cannery Formation on both Admiralty Island and Kupreanof Island is constrained by the stratigraphically overlying fossiliferous Pybus Formation, of late early and early late Permian age. Because bedded radiolarian
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DEFF Research Database (Denmark)
Bjørk, Anders Anker; Björck, Svante; Cronholm, Anders
2011-01-01
. The irregular shapes of the basins and the lack of clear erosional features indicate that they are not eruption craters and were not formed by erosion. Instead, we regard them as morphological depressions formed between ridges of trachytic lava flows and domes at a late stage of the formation of the volcanic...... edifice. The onset of sedimentation within these basins appears to have occurred between 24 and 37 ka with the highest situated wetland yielding the highest ages. These ages are very young compared to the timing of the main phase of the formation of the island, implying volcanic activity on the island......Tristan da Cunha is a volcanic island group situated in the central South Atlantic. The oldest of these islands, Nightingale Island, has an age of about 18Ma. In the interior of the island, there are several wetlands situated in topographic depressions. The ages of these basins have been unknown...
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Nano-sized Adsorbate Structure Formation in Anisotropic Multilayer System
Kharchenko, Vasyl O.; Kharchenko, Dmitrii O.; Yanovsky, Vladimir V.
2017-05-01
In this article, we study dynamics of adsorbate island formation in a model plasma-condensate system numerically. We derive the generalized reaction-diffusion model for adsorptive multilayer system by taking into account anisotropy in transfer of adatoms between neighbor layers induced by electric field. It will be found that with an increase in the electric field strength, a structural transformation from nano-holes inside adsorbate matrix toward separated nano-sized adsorbate islands on a substrate is realized. Dynamics of adsorbate island sizes and corresponding distributions are analyzed in detail. This study provides an insight into details of self-organization of adatoms into nano-sized adsorbate islands in anisotropic multilayer plasma-condensate systems.
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Foundation Investigation for Ground Based Radar Project-Kwajalein Island, Marshall Islands
1990-04-01
iL_ COPY MISCELLANEOUS PAPER GL-90-5 i iFOUNDATION INVESTIGATION FOR GROUND BASED RADAR PROJECT--KWAJALEIN ISLAND, MARSHALL ISLANDS by Donald E...C!assification) Foundatioa Investigation for Ground Based Radar Project -- Kwajalein Island, Marshall Islands 12. PERSONAL AUTHOR(S) Yule, Donald E...investigation for the Ground Based Radar Project -- Kwajalein Island, Marshall Islands , are presented.- eophysical tests comprised of surface refrac- tion
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Matande, Jumiati Bunga; Zakir, Muhammad; Noor, Alfian
2017-01-01
Research on the use of diethanolamine (DEA) as a CO2 absorbent in was take the determination coral reef age in Barrang Lompo Island, Spermonde Islands through measurements of 14C activity by liquid scintillation Counting method (LSC) was carried our. Coral reef sample of the island Barrang Lompo at coordinates 5 ° 06 '49 " LS 119 ° 25' 20" BT with a dept of 3-4 meters from the sea surface. Coral reefs (coral reef) is an ecosystem that live on the water in the form of limestone formations (CaC...
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Pseudomonas aeruginosa pathogenicity island 1 (PAPI-1) is one of the largest genomic islands of this important opportunistic human pathogen. Previous studies have shown that PAPI-1 encodes several putative virulence factors, a major regulator of biofilm formation, and antibiotic-resistance traits, a...
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Petrology of the prehistoric lavas and dyke of the Barren Island ...
Indian Academy of Sciences (India)
R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22
historic times, the eruptions that led to the formation of this volcanic island occurred mainly during prehistoric times. ... eruptions occurred from its centre, producing a. 250m high ... non-eruptive lateral landslide of the original cone or by vertical ...
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Directory of Open Access Journals (Sweden)
Sia Rosalind Juo Ling
2017-01-01
Full Text Available Haidian Island, which situated at the Northern part of Haikou City of Hainan Province, is an island within a city. Haidian Island is unique in term of it's development which centered around an university, the Hainan University, besides some others important landmarks, such as Haikou city hospital, Baishamen municipal park, Golf Driving Range etc. All commercials, residential, recreational activities etc are planned to serve Hainan University in particular. The study, taking ‘Haidian Island Area Development Control Plan’ as case study, would like to look into the importance of transportation and traffic planning. The study used observation, site investigation and traffic study methods to gather data needed. Firstly the study analyzed the current state of transportation system for Haidian Island in accordance to the Island Development Control plan and Haikou master plan and identified the problems. Then, the study made some recommendations for these problems. The study highlighted the important of non-motorized, cycling and walking as the main transportation system for an education-based island and as supportive to domestic tourism activities found. The transportation planning suggested by the study took ‘green and low-carbon’ approaches considered the role of University as the core activity in the island.
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Tectonomagmatic activity and ice dynamics in the Bransfield Strait back-arc basin, Antarctica
Dziak, Robert P.; Park, Minkyu; Lee, Won Sang; Matsumoto, Haru; Bohnenstiehl, Delwayne R.; Haxel, Joseph H.
2010-01-01
An array of moored hydrophones was used to monitor the spatiotemporal distribution of small- to moderate-sized earthquakes and ice-generated sounds within the Bransfield Strait, Antarctica. During a 2 year period, a total of 3900 earthquakes, 5925 icequakes and numerous ice tremor events were located throughout the region. The seismic activity included eight space-time earthquake clusters, positioned along the central neovolcanic rift zone of the young Bransfield back-arc basin. These sequences of small magnitude earthquakes, or swarms, suggest ongoing magmatic activity that becomes localized along isolated volcanic features and fissure-like ridges in the southwest portion of the basin. A total of 122 earthquakes were located along the South Shetland trench, indicating continued deformation and possibly ongoing subduction along this margin. The large number of icequakes observed show a temporal pattern related to seasonal freeze-thaw cycles and a spatial distribution consistent with channeling of sea ice along submarine canyons from glacier fronts. Several harmonic tremor episodes were sourced from a large (˜30 km2) iceberg that entered northeast portion of the basin. The spectral character of these signals suggests they were produced by either resonance of a small chamber of fluid within the iceberg, or more likely, due to periodicity of discrete stick-slip events caused by contact of the moving iceberg with the seafloor. These pressure waves appear to have been excited by abrasion of the iceberg along the seafloor as it passed Clarence and Elephant Islands.
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Compositional searching of CpG islands in the human genome
Luque-Escamilla, Pedro Luis; Martínez-Aroza, José; Oliver, José L.; Gómez-Lopera, Juan Francisco; Román-Roldán, Ramón
2005-06-01
We report on an entropic edge detector based on the local calculation of the Jensen-Shannon divergence with application to the search for CpG islands. CpG islands are pieces of the genome related to gene expression and cell differentiation, and thus to cancer formation. Searching for these CpG islands is a major task in genetics and bioinformatics. Some algorithms have been proposed in the literature, based on moving statistics in a sliding window, but its size may greatly influence the results. The local use of Jensen-Shannon divergence is a completely different strategy: the nucleotide composition inside the islands is different from that in their environment, so a statistical distance—the Jensen-Shannon divergence—between the composition of two adjacent windows may be used as a measure of their dissimilarity. Sliding this double window over the entire sequence allows us to segment it compositionally. The fusion of those segments into greater ones that satisfy certain identification criteria must be achieved in order to obtain the definitive results. We find that the local use of Jensen-Shannon divergence is very suitable in processing DNA sequences for searching for compositionally different structures such as CpG islands, as compared to other algorithms in literature.
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Islands and non-islands in native and heritage Korean
Directory of Open Access Journals (Sweden)
Boyoung eKim
2016-02-01
Full Text Available To a large extent, island phenomena are cross-linguistically invariable, but English and Korean present some striking differences in this domain. English has wh-movement and Korean does not, and while both languages show sensitivity to wh-islands, only English has island effects for adjunct clauses. Given this complex set of differences, one might expect Korean/English bilinguals, and especially heritage Korean speakers (i.e. early bilinguals whose L2 became their dominant language during childhood to be different from native speakers, since heritage speakers have had more limited exposure to Korean, may have had incomplete acquisition and/or attrition, and may show significant transfer effects from the L2. Here we examine islands in heritage speakers of Korean in the U.S. Through a series of four formal acceptability experiments comparing these heritage speakers with native speakers residing in Korea, we show that the two groups are remarkably similar. Both show clear evidence for wh-islands and an equally clear lack of adjunct island effects. Given the very different linguistic environment that the heritage speakers have had since early childhood, this result lends support to the idea that island phenomena are largely immune to environmental influences and stem from deeper properties of the processor and/or grammar. Similarly, it casts some doubt on recent proposals that islands are learned from the input.
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Class renormalization: islands around islands
International Nuclear Information System (INIS)
Meiss, J.D.
1986-01-01
An orbit of 'class' is one that rotates about a periodic orbit of one lower class with definite frequency. This contrasts to the 'level' of a periodic orbit which is the number of elements in its continued fraction expansion. Level renormalization is conventionally used to study the structure of quasi-periodic orbits. The scaling structure of periodic orbits encircling other periodic orbits in area preserving maps is discussed here. Fixed points corresponding to the accumulation of p/q bifurcations are found and scaling exponents determined. Fixed points for q > 2 correspond to self-similar islands around islands. Frequencies of the island boundary circles at the fixed points are obtained. Importance of this scaling for the motion of particles in stochastic regions is emphasized. (author)
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The occurrence and development of peat mounds on King George Island (Maritime Antarctic
Directory of Open Access Journals (Sweden)
Jerzy Fabiszewski
2014-01-01
Full Text Available On King George Island, South Shetlands Islands, a type of peat formation has been discovered which has not previously been reported from the Antarctic. These formations are in shape of mounds up to 7x 15 m in area, with a peat layer of about I m thick. About twenty five cm below the surface there is a layer of permanently frozen peat. The mounds are covered by living mosses (Polytrichum alpinum and Drepanocladus uncinatus, Antarctic hair grass (Deschampsia antarctica and lichens. Erosion fissures occurring on the surface are evidence of contemporary drying and cessation of the mound's growth. The initial phase of the development of the mounds began with a community dominated by Calliergidium austro-stramineum and Deschampsia antarctica, and their further development has been due to peat accumulation formed almost entirely by Calliergidium. The location of the mounds is near a penguin rookery, which clearly conditioned the minerotrophic character of these formations, as compared with the "moss peat banks" formed by Chorisodontium aciphyllum and Polytrichum al-pestre. Moreover, the peat mounds differ from the latter in several ways, e.g. rate of growth and floristic composition. Radiocarbon dating of peat from the base of one mound gave an age of 4090±60 years B.P. This suggests that the age of the tundra on King George Island is about 5000-4000 years.
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Mercury in Aquatic Systems of the Gulf Islands National Seashore ...
African Journals Online (AJOL)
This study reports on levels and speciation of mercury (Hg) in different environmental compartments of selected park units in the Gulf Islands National Seashore (USA), and on potential rates of methyl-Hg (MMHg) formation and degradation in sediments. In the aqueous phase, total (THg) and MMHg concentrations ranged ...
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Polygonal patterned peatlands of the White Sea islands
Kutenkov, S. A.; Kozhin, M. N.; Golovina, E. O.; Kopeina, E. I.; Stoikina, N. V.
2018-03-01
The summits and slopes of some islands along the northeastern and northern coasts of the White Sea are covered with dried out peatlands. The thickness of the peat deposit is 30–80 cm and it is separated by troughs into gently sloping polygonal peat blocks up to 20 m2 in size. On some northern islands the peat blocks have permafrost cores. The main components of the dried out peatlands vegetation are dwarf shrubs and lichens. The peat stratigraphy reveals two stages of peatland development. On the first stage, the islands were covered with wet cottongrass carpets, which repeated the convex relief shape. On the second stage, they were occupied by the xeromorphic vegetation. We suggest that these polygonal patterned peatlands are the remnants of blanket bogs, the formation of which assumes the conditions of a much more humid climate in the historical past. The time of their active development was calculated according to the White Sea level changes and radiocarbon dates from 1000–4000 BP.
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Directory of Open Access Journals (Sweden)
Marcelo A. Reguero
2013-06-01
Full Text Available The La Meseta Formation crops out in Seymour/Marambio Island, Weddell Sea, northeast of the Antarctic Peninsula and contains one of the world's most diverse assemblages of Weddellian marine/coastal verte-brates of Early Eocene (Ypresian age. The La Meseta Formation is composed of poorly consolidated, marine sandstones and siltstones which were deposited in a coastal, deltaic and/or estuarine environment. It includes marine invertebrates and vertebrates as well as terrestrial vertebrates and plants. The highly fossiliferous basal horizon (Cucullaeashell bed, Telm 4 of Sadler 1988 of the CucullaeaI Allomember is a laterally extensive shell bed with sandy matrix. The fish remains, including 35 species from 26 families, of the Ypresian Cucullaeabed represent one of the most abundant and diverse fossil vertebrate faunas yet recorded in southern latitudes. Stratigraphic distribution and phylogenetic relationships of the Weddellian sphenisciforms are consistent with a first radiation of this group in the Early Eocene. The first inquestionable archaeocete from Antarctica is recorded in this unit and is referred to a new taxon.
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Directory of Open Access Journals (Sweden)
Kukui Firmin Jeevo
2016-12-01
Full Text Available Ice sheet exerts a force on the hydraulic structures and vessels with developing and transporting hydrocarbons in the offshore waters of the Arctic causing to strengthen their design and/or provide additional measures against ice loads. The risk of ice impacts on objects of offshore oil and gas fields of the Arctic region determines the existence of the problem of ensuring the sustainability of these objects in terms of iceberg danger and ice formations. Reducing these risks involves the development of organizational and technical measures for improving the sustainability of the facilities in terms of iceberg danger through the use of international experience and development of advanced technologies to prevent dangerous effects of ice formations. Based on the fact that ice management is a specific activity that requires special effort and funds which as part of the rescue security (RS forces at sea are missing, as well as on the basis of the fact that the system of RS at sea is not assigned to prevent accidents and to ensure the smooth operation of offshore facilities, an ice management is seen as an independent kind of ensuring the proper functioning objects of hydrocarbons production and marine transportation. The paper considers the analysis and synthesis of domestic and foreign experience of ice and iceberg management. A system of security measures for functioning marine oil and gas facilities in icy conditions on the basis of technology of preventing dangerous effects of ice formations has been worked out. It has been shown that the system of ice and iceberg management of marine objects of hydrocarbon production and marine transportation should be a practical mechanism for reducing deposits' operation risks in ice conditions. The work relates to the safe operation of mining platforms in the Arctic seas, and more particularly, to methods and means of influence on the icebergs in order to prevent collisions with fixed or floating production
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International Nuclear Information System (INIS)
Oikawa, T.; Suzuki, T.; Isayama, A.; Hayashi, N.; Fujita, T.; Naito, O.; Tuda, T.; Kurita, G.
2005-01-01
Evolution of the current density profile associated with magnetic island formation in a neoclassical tearing mode plasma is measured for the first time in JT-60U by using a motional Stark effect diagnostic. As the island grows, the current density profile turns flat at the radial region of the island and a hollow structure appears at the rational surface. As the island shrinks the deformed region becomes narrower and finally diminishes after the disappearance of the island. In a quiescent plasma without magnetohydrodynamic instabilities, on the other hand, no deformation is observed. The observed deformation in the current density profile associated with the tearing mode is reproduced in a time dependent transport simulation assuming the reduction of the bootstrap current in the radial region of the island. Comparison of the measurement with a calculated steady-state solution also shows that the reduction and recovery of the bootstrap current at the island explains the temporal behaviours of the current density and safety factor profiles. From the experimental observation and simulations, we reach the conclusion that the bootstrap current decreases within the island O-point
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The Influence of biol in the crop yield of Lactuca sativa L. variety Iceberg
Directory of Open Access Journals (Sweden)
Pomboza-Tamaquiza Pablo
2016-11-01
Full Text Available The objective of the research was to assess the influence of biol enriched with efficient micro-organisms, in the ecological cultivation of Lactuca sativa L (lettuce variety "Iceberg". The field test was carried out on the farm of Querochaca, Faculty of Sciences Agriculture, of the Technical University of Ambato. The studied factors were doses of biol (2%, 4% and 6% and frequencies of application (8 and 15 days, I know used the experimental design of complete blocks at random, with factorial arrangement of 3x2 1 with three repetitions. We evaluated: plant height, diameter of the main stem, days to harvest, weight and diameter of the bud commercial, performance in kg/plot neta and performance in kg/experimental unit, conducted the significance test of Duncan to 5%. The results showed that the dose of 6 per cent applied every 15 days treatment D3F2, contributed to the larger diameter of the bud commercial (25.9 cm; the greater weight of cogollo commercial (1.14 kg and the higher performance (549 kg/experimental unit. This suggests that the implementation of biol can be an important ecological alternative to fertilize organic farming as the lettuce by reducing the use of fertilizers in chemical synthesis and production costs.
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Energy Technology Data Exchange (ETDEWEB)
Gorsevski, V.; Taha, H.; Quattrochi, D.; Luvall, J.
1998-07-01
Urban heat islands increase the demand for cooling energy and accelerate the formation of smog. They are created when natural vegetation is replaced by heat-absorbing surfaces such as building roofs and walls, parking lots, and streets. Through the implementation of measures designed to mitigate the urban heat island, communities can decrease their demand for energy and effectively cool the metropolitan landscape. In addition to the economic benefits, using less energy leads to reductions in emission of CO{sub 2}--a greenhouse gas--as well as ozone (smog) precursors such as NOx and VOCs. Because ozone is created when NOx and VOCs photochemically combine with heat and solar radiation, actions taken to lower ambient air temperature can significantly reduce ozone concentrations in certain areas. Measures to reverse the urban heat island include afforestation and the widespread use of highly reflective surfaces. To demonstrate the potential benefits of implementing these measures, EPA has teamed up with NASA and LBNL to initiate a pilot project with three US cities. As part of the pilot, NASA will use remotely-sensed data to quantify surface temperature, albedo, the thermal response number and NDVI vegetation of each city. This information will be used by scientists at Lawrence Berkeley National Laboratory (LBNL) along with other data as inputs to model various scenarios that will help quantify the potential benefits of urban heat island mitigation measures in terms of reduced energy use and pollution. This paper will briefly describe this pilot project and provide an update on the progress to date.
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Topographic lidar survey of the Chandeleur Islands, Louisiana, February 6, 2012
Guy, Kristy K.; Plant, Nathaniel G.; Bonisteel-Cormier, Jamie M.
2014-01-01
This Data Series Report contains lidar elevation data collected February 6, 2012, for Chandeleur Islands, Louisiana. Point cloud data in lidar data exchange format (LAS) and bare earth digital elevation models (DEMs) in ERDAS Imagine raster format (IMG) are available as downloadable files. The point cloud data—data points described in three dimensions—were processed to extract bare earth data; therefore, the point cloud data are organized into the following classes: 1– and 17–unclassified, 2–ground, 9–water, and 10–breakline proximity. Digital Aerial Solutions, LLC, (DAS) was contracted by the U.S. Geological Survey (USGS) to collect and process these data. The lidar data were acquired at a horizontal spacing (or nominal pulse spacing) of 0.5 meters (m) or less. The USGS conducted two ground surveys in small areas on the Chandeleur Islands on February 5, 2012. DAS calculated a root mean square error (RMSEz) of 0.034 m by comparing the USGS ground survey point data to triangulated irregular network (TIN) models built from the lidar elevation data. This lidar survey was conducted to document the topography and topographic change of the Chandeleur Islands. The survey supports detailed studies of Louisiana, Mississippi and Alabama barrier islands that resolve annual and episodic changes in beaches, berms and dunes associated with processes driven by storms, sea-level rise, and even human restoration activities. These lidar data are available to Federal, State and local governments, emergency-response officials, resource managers, and the general public.
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Williams, S. Jeffress; Foley, Mary K.
2007-01-01
) policy stipulates that natural coastal processes be maintained to the greatest extent possible and not be impeded so as to conserve landforms, habitats and natural ecosystem resources that reply on the landforms and processes for long-term sustainability of the national park. Storms and associated processes such as waves, tides, currents and relative sea-level change are critical elements for the formation and evolution of these barrier islands, sand dunes, back-barrier sand flats and lagoons and vegetated wetlands. Processes such as wave run-up, overwash and barrier beaching, which occur during elevated storm surge are all necessary processes in enabling the efficient transfer of sediments, nutrients and marine water from the Atlantic Ocean across barriers and into Great South Bay. A large body of scientific data and information published over the past 50 years shows that such transfers of sediment and water from the ocean to the bays are essential for the long-term maintenance of the barrier island and back-bay systems and their biologically diverse habitats an d ecosystems. Current relative sea-level rise (~12 in/century) is chronic and pervasive in driving Long Island coastal change and with the likelihood of accelerating sea level rise in the near future, coastal hazards such as erosion, inundation, and storm surge flooding will increase, with corresponding increased risk to life and property on both Fire Island and on the mainland. In addition, the cumulative effects over the past century and more, both direct and indirect, of human impacts on the Long Island coast have altered the barrier beach and dunes and sediment transport processes. These impacts have likely increased the potential for breaching and increased risk to life and property on the coast and the mainland. Examples of direct impacts are: the stone jetties at Moriches, Shinnecock, and Fire Island tidal inlets and groin field structures at Westhampton that alter littoral processes, armoring and erosion
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National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the shelf and slope environments of Johnston Island, Pacific Island Areas, Central Pacific. These...
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Fleischer, R C; McIntosh, C E; Tarr, C L
1998-04-01
The Hawaiian Islands form as the Pacific Plate moves over a 'hot spot' in the earth's mantle where magma extrudes through the crust to build huge shield volcanos. The islands subside and erode as the plate carries them to the north-west, eventually to become coral atolls and seamounts. Thus islands are ordered linearly by age, with the oldest islands in the north-west (e.g. Kauai at 5.1 Ma) and the youngest in the south-east (e.g. Hawaii at 0.43 Ma). K-Ar estimates of the date of an island's formation provide a maximum age for the taxa inhabiting the island. These ages can be used to calibrate rates of molecular change under the following assumptions: (i) K-Ar dates are accurate; (ii) tree topologies show that derivation of taxa parallels the timing of island formation; (iii) populations do not colonize long after island emergence; (iv) the coalescent point for sister taxa does not greatly predate the formation of the colonized younger island; (v) saturation effects and (vi) among-lineage rate variation are minimal or correctable; and (vii) unbiased standard errors of distances and regressions can be estimated from multiple pairwise comparisons. We use the approach to obtain overall corrected rate calibrations for: (i) part of the mitochondrial cytochrome b gene in Hawaiian drepanidines (0.016 sequence divergence/Myr); (ii) the Yp1 gene in Hawaiian Drosophila (0.019/Myr Kambysellis et al. 1995); and (iii) parts of the mitochondrial 12S and 16S rRNA and tRNAval in Laupala crickets (0.024-0.102/Myr, Shaw 1996). We discuss the reliability of the estimates given the assumptions (i-vii) above and contrast the results with previous calibrations of Adh in Hawaiian Drosophila and chloroplast DNA in lobeliods.
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Nomination of the Globigerina Limestone of the Maltese Islands as a "Global Heritage Stone Resource"
Cassar, JoAnn
2016-04-01
The Maltese Islands consist of two main islands, Malta and Gozo, as well as a small number of islets, and lie in the central Mediterranean Sea approximately 90 km south of Sicily. Although only 316 square kilometres in size, the Islands contain a rich concentration of archaeological sites and historic buildings, as well as vernacular architecture and modern buildings, for the most part built of the local Globigerina Limestone, which is one of the few natural resources of the Islands. This stone can be described as a typical "soft limestone", very easy to carve and shape. It forms part of the large family of Oligo-Miocene "soft limestones" widely diffused in the Mediterranean Basin. The Maltese Globigerina Limestone Formation is one of five main Formations, and varies in thickness from 20 to over 200 m. The material used for building is located stratigraphically in the lower part of the Globigerina Limestone Formation, called the Lower Globigerina Limestone. This Formation is stratified into thick beds at outcrop. Sections where bioturbation is concentrated often also occur. This limestone is fine-grained, yellow to pale grey in colour, almost wholly composed of the tests of globigerinid planktonic foraminifera. Petrographically, Globigerina Limestone can be described as a bioclastic packstone, with bioclastic wackestones also occurring. This limestone has always been used as the predominant building material in the Islands. The Maltese prehistoric Temples, which were constructed approximately 6000 years ago, bear testimony to this. Between 1530 and 1798 the Order of the Knights of St John built kilometres of fortifications in this same material to protect the Island from the expanding Ottoman Empire. Fortifications, impressive churches, auberges and palaces were built of this stone during this period. The capital city of Valletta, a rich and dense manifestation of Baroque architecture in Globigerina Limestone, is included on the UNESCO World Heritage List, as are
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Magnússon, B.; Magnússon, S. H.; Ólafsson, E.; Sigurdsson, B. D.
2014-10-01
Plant colonization and succession on the volcanic island of Surtsey, formed in 1963, have been closely followed. In 2013, a total of 69 vascular plant species had been discovered on the island; of these, 59 were present and 39 had established viable populations. Surtsey had more than twice the species of any of the comparable neighbouring islands, and all of their common species had established on Surtsey. The first colonizers were dispersed by sea, but, after 1985, bird dispersal became the principal pathway with the formation of a seagull colony on the island and consequent site amelioration. This allowed wind-dispersed species to establish after 1990. Since 2007, there has been a net loss of species on the island. A study of plant succession, soil formation and invertebrate communities in permanent plots on Surtsey and on two older neighbouring islands (plants and soil) has revealed that seabirds, through their transfer of nutrients from sea to land, are major drivers of development of these ecosystems. In the area impacted by seagulls, dense grassland swards have developed and plant cover, species richness, diversity, plant biomass and soil carbon become significantly higher than in low-impact areas, which remained relatively barren. A similar difference was found for the invertebrate fauna. After 2000, the vegetation of the oldest part of the seagull colony became increasingly dominated by long-lived, rhizomatous grasses (Festuca, Poa, Leymus) with a decline in species richness and diversity. Old grasslands of the neighbouring islands Elliđaey (puffin colony, high nutrient input) and Heimaey (no seabirds, low nutrient input) contrasted sharply. The puffin grassland of Elliđaey was very dense and species-poor. It was dominated by Festuca and Poa, and very similar to the seagull grassland developing on Surtsey. The Heimaey grassland was significantly higher in species richness and diversity, and had a more even cover of dominants (Festuca
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Tuppiap Qeqertaa (Tobias Island): a newly discovered island off northeast Greenland
DEFF Research Database (Denmark)
Bennike, O.; Mikkelsen, N.; Forsberg, René
2006-01-01
The small island of Tuppiap Qeqertaa, formerly known as Tobias circle divide or Tobias Island, is situated 80 km off the northeast Greenland coast. The island was discovered in 1993 and is approximately 2 km long and 1.5 km wide. Most of the island is covered by an ice cap that rises to 35 in abo...
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Diomede Islands, Bering Straight
2008-01-01
The Diomede Islands consisting of the western island Big Diomede (also known as Imaqliq, Nunarbuk or Ratmanov Island), and the eastern island Little Diomede (also known as Krusenstern Island or Inaliq), are two rocky islands located in the middle of the Bering Strait between Russia and Alaska. The islands are separated by an international border and the International Date Line which is approximately 1.5 km from each island; you can look from Alaska into tomorrow in Russia. At the closest land approach between the United States, which controls Little Diomede, and Russia, which controls Big Diomede, they are 3 km apart. Little Diomede Island constitutes the Alaskan City of Diomede, while Big Diomede Island is Russia's easternmost point. The first European to reach the islands was the Russian explorer Semyon Dezhnev in 1648. The text of the 1867 treaty finalizing the sale of Alaska uses the islands to designate the border between the two nations. The image was acquired July 8, 2000, covers an area of 13.5 x 10.8 km, and is located at 65.8 degrees north latitude, 169 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.
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Sociodemographic Factors Influencing Island Food Consumption in the Pacific Islander Health Study
Baumhofer, Nicole Kau'i
2016-01-01
This dissertation explores the relationships between island food consumption, sociodemographic variables, and cardiovascular risk using data from the Pacific Islander Health Study (PIHS). Chapter 1 explores the associations between self-reported level of island food consumption and key covariates. Island food consumption was modeled using Poisson regression and adjusted for demographic, socioeconomic, and cultural characteristics. Increased Pacific Island cultural affinity was the strongest p...
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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.
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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
An unusually thick (c. 88 m), transgressive barrier island and shoreface sandstone succession characterizes the Upper Jurassic Heno Formation reservoir of the Freja oil field situated on the boundary of Denmark and Norway. The development and preservation of such thick transgressive barrier island...... sands is puzzling since a barrier island typically migrates landwards during transgression and only a thin succession of back-barrier and shoreface sands is preserved. Investigation of the development and geometry of the Freja reservoir sandstones is problematic since the reservoir is buried c. 5 km...... and 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...
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Multi-scale interaction between magnetic islands and microturbulence in magnetized plasmas
International Nuclear Information System (INIS)
Muraglia, M.
2009-10-01
In a tokamak, it exists many kinds of instability at the origin of a damage of the confinement and worst of a lost of a confinement. This work presents a study of the dynamics of a magnetic island in presence of turbulence in magnetized plasmas. More precisely, the goal is to understand the multi-scales interaction between turbulence, generated by a pressure gradient and the magnetic field curvature, and a magnetic island formed thanks to a tearing mode. Thanks to the derivation of a 2-dimensional slab model taking into account both tearing and interchange instabilities, theoretical and numerical linear studies show the pressure effect on the magnetic island linear formation and show interchange modes are stabilized in presence of a strong magnetic field. Then, a numerical nonlinear study is presented in order to understand how the interchange mechanism affects the nonlinear dynamics of a magnetic island. It is shown that the pressure gradient and the magnetic field curvature affect strongly the nonlinear evolution of a magnetic island through dynamics bifurcations. The nature of these bifurcations should be characterized in function of the linear situation. Finally, the last part of this work is devoted to the study of the origin of the nonlinear poloidal rotation of the magnetic island. A model giving the different contributions to the rotation is derived. It is shown, thanks to the model and to the numerical studies, that the nonlinear rotation of the island is mainly governed by the ExB poloidal flow and/or by the nonlinear diamagnetic drift. (author)
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Using Continuum Damage Mechanics to Simulate Iceberg Calving from Tidewater Outlet Glaciers
Mercenier, R.; Lüthi, M.; Vieli, A.
2017-12-01
Many ocean terminating glaciers in the Arctic are currently undergoingrapid retreat, thinning and strong accelerations in flow. The processof iceberg calving plays a crucial role for the related dynamical masslosses and occurs when the stresses at the calving front exceed thefracture strength of ice, driving the propagation of cracks andeventually leading to the detachment of ice blocks from the glacierfront. However, the understanding of the processes involved in icebergcalving as well as the capability of flow models to represent thecalving mechanism remain limited.Here, we use a time-dependent two-dimensional finite-element flowmodel coupled to a damage model to simulate the break-off of ice atthe front of idealized tidewater outlet glaciers. The flow modelcomputes flow velocities and the resulting stresses, which are in turnused to calculate the evolution of the glacier geometry anddamage. Damage is defined as a change of rheological properties, e.g.viscosity, due to increasing material degradation. Elements of ice areremoved when the damage variable reaches a critical threshold. Theeffects of material properties and of geometrical parameters such aswater depth, ice thickness and submarine frontal melting on thesimulated calving rates are explored through systematic sensitivityanalyses.The coupled ice flow/damage model allows for successful reproductionof calving front geometries typically observed for different waterdepths. We further use detailed observations from real glaciergeometries to better constrain the model parameters. Theproposed model approach should be applicable to simulate icebergcalving on arbitrary glaciers, and thus be used to analyse theevolution of tidewater glacier variations from the past to the future.
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Exciton dephasing and biexciton binding in CdSe/ZnSe islands
DEFF Research Database (Denmark)
Wagner, Hans Peter; Tranitz, H.-P.; Preis, H
1999-01-01
The dephasing of excitons and the formation of biexcitons in self-organized CdSe/ZnSe islands grown by molecular-beam epitaxy is investigated using spectrally resolved four-wave mixing. A distribution of exciton-exciton scattering efficiencies and dephasing times in the range of 0.5-10 ps...
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The island dynamics model on parallel quadtree grids
Mistani, Pouria; Guittet, Arthur; Bochkov, Daniil; Schneider, Joshua; Margetis, Dionisios; Ratsch, Christian; Gibou, Frederic
2018-05-01
We introduce an approach for simulating epitaxial growth by use of an island dynamics model on a forest of quadtree grids, and in a parallel environment. To this end, we use a parallel framework introduced in the context of the level-set method. This framework utilizes: discretizations that achieve a second-order accurate level-set method on non-graded adaptive Cartesian grids for solving the associated free boundary value problem for surface diffusion; and an established library for the partitioning of the grid. We consider the cases with: irreversible aggregation, which amounts to applying Dirichlet boundary conditions at the island boundary; and an asymmetric (Ehrlich-Schwoebel) energy barrier for attachment/detachment of atoms at the island boundary, which entails the use of a Robin boundary condition. We provide the scaling analyses performed on the Stampede supercomputer and numerical examples that illustrate the capability of our methodology to efficiently simulate different aspects of epitaxial growth. The combination of adaptivity and parallelism in our approach enables simulations that are several orders of magnitude faster than those reported in the recent literature and, thus, provides a viable framework for the systematic study of mound formation on crystal surfaces.
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Mechanisms driving variability in the ocean forcing of Pine Island Glacier.
Webber, Benjamin G M; Heywood, Karen J; Stevens, David P; Dutrieux, Pierre; Abrahamsen, E Povl; Jenkins, Adrian; Jacobs, Stanley S; Ha, Ho Kyung; Lee, Sang Hoon; Kim, Tae Wan
2017-02-17
Pine Island Glacier (PIG) terminates in a rapidly melting ice shelf, and ocean circulation and temperature are implicated in the retreat and growing contribution to sea level rise of PIG and nearby glaciers. However, the variability of the ocean forcing of PIG has been poorly constrained due to a lack of multi-year observations. Here we show, using a unique record close to the Pine Island Ice Shelf (PIIS), that there is considerable oceanic variability at seasonal and interannual timescales, including a pronounced cold period from October 2011 to May 2013. This variability can be largely explained by two processes: cumulative ocean surface heat fluxes and sea ice formation close to PIIS; and interannual reversals in ocean currents and associated heat transport within Pine Island Bay, driven by a combination of local and remote forcing. Local atmospheric forcing therefore plays an important role in driving oceanic variability close to PIIS.
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Researching Pacific island livelihoods:
DEFF Research Database (Denmark)
Egelund Christensen, Andreas; Mertz, Ole
2010-01-01
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....... The focus is on two dimensions of island livelihood, migration and natural resource management, both of which are significant contributors in making island livelihoods and shaping Pacific seascapes. We argue that there is still a substantial lack of studies targeting small island dynamics that are empirical...
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A genome-wide map of aberrantly expressed chromosomal islands in colorectal cancer
Directory of Open Access Journals (Sweden)
Castanos-Velez Esmeralda
2006-09-01
Full Text Available Abstract Background Cancer development is accompanied by genetic phenomena like deletion and amplification of chromosome parts or alterations of chromatin structure. It is expected that these mechanisms have a strong effect on regional gene expression. Results We investigated genome-wide gene expression in colorectal carcinoma (CRC and normal epithelial tissues from 25 patients using oligonucleotide arrays. This allowed us to identify 81 distinct chromosomal islands with aberrant gene expression. Of these, 38 islands show a gain in expression and 43 a loss of expression. In total, 7.892 genes (25.3% of all human genes are located in aberrantly expressed islands. Many chromosomal regions that are linked to hereditary colorectal cancer show deregulated expression. Also, many known tumor genes localize to chromosomal islands of misregulated expression in CRC. Conclusion An extensive comparison with published CGH data suggests that chromosomal regions known for frequent deletions in colon cancer tend to show reduced expression. In contrast, regions that are often amplified in colorectal tumors exhibit heterogeneous expression patterns: even show a decrease of mRNA expression. Because for several islands of deregulated expression chromosomal aberrations have never been observed, we speculate that additional mechanisms (like abnormal states of regional chromatin also have a substantial impact on the formation of co-expression islands in colorectal carcinoma.
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78 FR 63860 - Amendment of Class D Airspace; Kwajalein Island, Marshall Islands, RMI
2013-10-25
...This action amends the Kwajalein Island Class D airspace description by amending the geographic coordinates for Bucholz Army Airfield (AAF), Kwajalein Island, Marshall Islands, RMI. The Bucholz AAF geographic coordinates information was updated in the Kwajalein Island Class E airspace descriptions in 2011, but was inadvertently overlooked in the Kwajalein Island Class D airspace description. This action ensures the safety of aircraft operating in the Kwajalein Island airspace area. This is an administrative action and does not affect the operating requirements of the airspace.
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Stepping-stones to the Edge: Artistic Expressions of Islandness in an Ocean of Islands
Directory of Open Access Journals (Sweden)
Laurie Brinklow
2013-05-01
Full Text Available Since the earliest of times, islands have captured the artistic imagination—and, often, for the artist who finds his or her muse in being ‘islanded’, the smaller the island the better. Archipelagos offer an ideal setting for artists who take their inspiration from place: on small islands off islands they can experience an intensity of island living they might not otherwise have on a main island: boundedness and connection, isolation and community. This paper examines expressions of islandness by artists who live on islands off islands that are poles apart—‘archipelagos’ of the Canadian North Atlantic and the Great Southern Ocean. It draws upon interviews with those artists and writers to consider the nature of humans’ attachment and attraction to islands, exploring through the lens of phenomenology what Stratford et al. call the “entanglement between and among islands”.
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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.
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33 CFR 80.717 - Tybee Island, GA to St. Simons Island, GA.
2010-07-01
... Island. (j) An east-west line from the southernmost extremity of Sea Island across Goulds Inlet to St... Tybee Island 255° true across Tybee Inlet to the shore of Little Tybee Island south of the entrance to... shoreline across Cabretta Inlet. (g) A north-south line (longitude 81°16.9′ W.) drawn from the south...
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Energy Transition Initiative: Island Energy Snapshot - U.S. Virgin Islands (Fact Sheet)
Energy Technology Data Exchange (ETDEWEB)
2015-03-01
This profile provides a snapshot of the energy landscape of the U.S. Virgin Islands (USVI) - St. Thomas, St. John, and St. Croix. The Virgin Islands archipelago makes up the northern portion of the Lesser Antilles and the western island group of the Leeward Islands, forming the border between the Atlantic Ocean and the Caribbean Sea.
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76 FR 11227 - President's Advisory Commission on Asian Americans and Pacific Islanders
2011-03-01
... improve the economic and community development of AAPI businesses; and (iv) strategies to increase public... White House Initiative on Asian Americans and Pacific Islanders; and determine key strategies to help..., assistive listening devices, or material in alternative format) should notify Shelly Coles at (202) 453-7277...
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77 FR 22771 - President's Advisory Commission on Asian Americans and Pacific Islanders
2012-04-17
... businesses; and (iv) strategies to increase public and private-sector collaboration, and community... Islanders; and determine key strategies to help meet the Commission's charge as outlined in E.O. 13515..., assistive listening devices, or material in alternative format) should notify Shelly Coles at (202) 453-7277...
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46 CFR 7.70 - Folly Island, SC to Hilton Head Island, SC.
2010-10-01
... 46 Shipping 1 2010-10-01 2010-10-01 false Folly Island, SC to Hilton Head Island, SC. 7.70 Section... BOUNDARY LINES Atlantic Coast § 7.70 Folly Island, SC to Hilton Head Island, SC. (a) A line drawn from the...′ W. (Port Royal Sound Lighted Whistle Buoy “2PR”); thence to the easternmost extremity of Hilton Head...
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International Nuclear Information System (INIS)
Bollani, M; Fedorov, A; Chrastina, D; Sordan, R; Picco, A; Bonera, E
2010-01-01
Si 1-x Ge x islands grown on Si patterned substrates have received considerable attention during the last decade for potential applications in microelectronics and optoelectronics. In this work we propose a new methodology to grow Ge-rich islands using a chemical vapour deposition technique. Electron-beam lithography is used to pre-pattern Si substrates, creating material traps. Epitaxial deposition of thin Ge films by low-energy plasma-enhanced chemical vapour deposition then leads to the formation of Ge-rich Si 1-x Ge x islands (x > 0.8) with a homogeneous size distribution, precisely positioned with respect to the substrate pattern. The island morphology was characterized by atomic force microscopy, and the Ge content and strain in the islands was studied by μRaman spectroscopy. This characterization indicates a uniform distribution of islands with high Ge content and low strain: this suggests that the relatively high growth rate (0.1 nm s -1 ) and low temperature (650 deg. C) used is able to limit Si intermixing, while maintaining a long enough adatom diffusion length to prevent nucleation of islands outside pits. This offers the novel possibility of using these Ge-rich islands to induce strain in a Si cap.
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Bollani, M; Chrastina, D; Fedorov, A; Sordan, R; Picco, A; Bonera, E
2010-11-26
Si(1-x)Ge(x) islands grown on Si patterned substrates have received considerable attention during the last decade for potential applications in microelectronics and optoelectronics. In this work we propose a new methodology to grow Ge-rich islands using a chemical vapour deposition technique. Electron-beam lithography is used to pre-pattern Si substrates, creating material traps. Epitaxial deposition of thin Ge films by low-energy plasma-enhanced chemical vapour deposition then leads to the formation of Ge-rich Si(1-x)Ge(x) islands (x > 0.8) with a homogeneous size distribution, precisely positioned with respect to the substrate pattern. The island morphology was characterized by atomic force microscopy, and the Ge content and strain in the islands was studied by μRaman spectroscopy. This characterization indicates a uniform distribution of islands with high Ge content and low strain: this suggests that the relatively high growth rate (0.1 nm s(-1)) and low temperature (650 °C) used is able to limit Si intermixing, while maintaining a long enough adatom diffusion length to prevent nucleation of islands outside pits. This offers the novel possibility of using these Ge-rich islands to induce strain in a Si cap.
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Pushkarev, E. V.; Ryazancev, A. V.; Gottman, I. A.; Degtyarev, K. E.; Kamenetsky, V. S.
2018-04-01
This work describes the geological position, mineral and chemical composition of high-Mg effusive ankaramites occurring as dykes and lava flows. They were found in the mélange zone of the western margin of the Magnitogorsk island arc zone in the Southern Urals. Data on the liquidus association of phenocrysts and on the composition of the matrix of effusives are given. According to the data obtained, the conclusion was drawn that the ankaramites studied can be attributed to the primary island arc melts, which were not subject to essential differentiation. This type of effusives has not been distinguished previously among island arc volcanogenic formations of the Urals. It is shown that ankaramites can be considered to be primary melts parental for dunite-clinopyroxenites-gabbro complexes of Ural-Alaskan type. The occurrence of ankaramites in the Paleozoic island arc formations of the Urals indicates the wehrlite composition of the mantle as the reason for the extremely wide development of wehrlites and clinopyroxenites in different mafic-ultramafic complexes of the Urals.
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Nagarajan, Ramasamy; Roy, Priyadarsi D.; Kessler, Franz L.; Jong, John; Dayong, Vivian; Jonathan, M. P.
2017-08-01
An integrated study using bulk chemical composition, mineralogy and mineral chemistry of sedimentary rocks from the Tukau Formation of Borneo Island (Sarawak, Malaysia) is presented in order to understand the depositional and tectonic settings during the Neogene. Sedimentary rocks are chemically classified as shale, wacke, arkose, litharenite and quartz arenite and consist of quartz, illite, feldspar, rutile and anatase, zircon, tourmaline, chromite and monazite. All of them are highly matured and were derived from a moderate to intensively weathered source. Bulk and mineral chemistries suggest that these rocks were recycled from sedimentary to metasedimentary source regions with some input from granitoids and mafic-ultramafic rocks. The chondrite normalized REE signature indicates the presence of felsic rocks in the source region. Zircon geochronology shows that the samples were of Cretaceous and Triassic age. Comparable ages of zircon from the Tukau Formation sedimentary rocks, granitoids of the Schwaner Mountains (southern Borneo) and Tin Belt of the Malaysia Peninsular suggest that the principal provenance for the Rajang Group were further uplifted and eroded during the Neogene. Additionally, presence of chromian spinels and their chemistry indicate a minor influence of mafic and ultramafic rocks present in the Rajang Group. From a tectonic standpoint, the Tukau Formation sedimentary rocks were deposited in a passive margin with passive collisional and rift settings. Our key geochemical observation on tectonic setting is comparable to the regional geological setting of northwestern Borneo as described in the literature.
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Energy Technology Data Exchange (ETDEWEB)
Aguero, J.L.; Beroqui, M.; Barbieri, B. [Universidad Nacional de La Plata, Buenos Aires (Argentina). Facultad de Ingenieria. Instituto de Investigaciones Tecnologicas para Redes y Equipos Electricos
2001-07-01
The goal of this paper is to describe, through an example, the aspects of importance to be taken into consideration for a successful electric island formation in cases that have an important generation excess with respect to the demand, and in cases that result in a balanced condition.This paper is based on the accomplished investigations due to the need of a petrochemistry industry of increasing the reliability of its electric power provision.
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Nanoparticles dynamics on a surface: fractal pattern formation and fragmentation
DEFF Research Database (Denmark)
Dick, Veronika V.; Solov'yov, Ilia; Solov'yov, Andrey V.
2010-01-01
In this paper we review our recent results on the formation and the post-growth relaxation processes of nanofractals on surface. For this study we developed a method which describes the internal dynamics of particles in a fractal and accounts for their diffusion and detachment. We demonstrate...... that these kinetic processes determine the final shape of the islands on surface after post-growth relaxation. We consider different scenarios of fractal relaxation and analyze the time evolution of the island's morphology....
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Nucleation of two-dimensional islands on Si (111) during high-temperature epitaxial growth
Energy Technology Data Exchange (ETDEWEB)
Sitnikov, S. V., E-mail: sitnikov@isp.nsc.ru; Kosolobov, S. S.; Latyshev, A. V. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Branch (Russian Federation)
2017-02-15
The process of two-dimensional island nucleation at the surface of ultra large Si (111) during hightemperature epitaxial growth is studied by in situ ultrahigh-vacuum reflection electron microscopy. The critical terrace size D{sub crit}, at which a two-dimensional island is nucleated in the center, is measured in the temperature range 900–1180°C at different silicon fluxes onto the surface. It is found that the parameter D{sub crit}{sup 2} is a power function of the frequency of island nucleation, with the exponent χ = 0.9 ± 0.05 in the entire temperature range under study. It is established that the kinetics of nucleus formation is defined by the diffusion of adsorbed silicon atoms at temperatures of up to 1180°C and the minimum critical nucleus size corresponds to 12 silicon atoms.
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Leonard Lardaro
2010-01-01
How can a state like Rhode Island have such a high unemployment rate? This question has been asked often over the past year, especially since at one point, Rhode Island found itself with the dubious distinction of having the highest unemployment rate in the United States. Following that extreme, Rhode Island seemed to settle into a niche where its rank was third nationally.
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Rudiastuti, A. W.; Munawaroh; Setyawan, I. E.; Pramono, G. H.
2018-04-01
Sustainable coastal management is playing an important role in coastal resources conservation, particularly on small islands. Karimata archipelago has unique characteristics and great potential to be developed as a tourism object, one of which is Karimata Island as the largest island and also reserve area. The concept of ecotourism focuses on the ecology conservation, economic benefits, and social life. Ecotourism aims to build sustainable tourism that provides economically viable and social benefits to the community. This study aims to develop coastal management strategy based on ecotourism at Karimata Island. Spatial approaching through coastal type was done. Qualitative descriptive analysis and SWOT are used to develop sustainable management strategies for the coast of Karimata Island, where the opportunities and challenges to the development of coastal ecotourism Karimata Island also included. If this potential is optimally utilized, it can be relied as an economic opportunity for local communities. Structurally shaped coast, marine depositional coast and coast build by organism are several of coastal types found at Karimata Island. Coastal ecosystems inhabited Karimata Island are mangroves, coral reefs, and macro-algae. Karimata Island have not been optimally utilized for tourist destinations. The biggest obstacle encountered is the accessibility from Kalimantan or other island at Karimata islands. Several problems related to the utilization of coastal resources were found such as mangrove and coral reef damage, also regulation that less supportive. The results of this study are expected to provide an overview of solutions for the development of coastal tourism potentials in Karimata Island.
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Self-sustained magnetic islands
Energy Technology Data Exchange (ETDEWEB)
Chatenet, J H; Luciani, J F [Ecole Polytechnique, 91 - Palaiseau (France); Garbet, X [Association Euratom-CEA, Centre d` Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee
1996-06-01
Numerical simulations of a single magnetic island evolution are presented in the regime where the island width is smaller than an ion Larmor radius. It is shown that the island rotation is controlled by particle diffusion due to collisions or a background of microturbulence. As expected from the theory of a stationary island, there exist cases where linearly stable magnetic perturbation are nonlinearly self-sustained. This situation corresponds to large poloidal beta and temperature gradient. The drive is due to diamagnetic frequency effects. However, this situation is not generic, and islands can also decay. It is found that a magnetic island is self-sustained for a negative off-diagonal diffusion coefficient. This case occurs in a tokamak if the inward particle pinch is due to the temperature gradient. (author). 30 refs.
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Self-sustained magnetic islands
International Nuclear Information System (INIS)
Chatenet, J.H.; Luciani, J.F.; Garbet, X.
1996-06-01
Numerical simulations of a single magnetic island evolution are presented in the regime where the island width is smaller than an ion Larmor radius. It is shown that the island rotation is controlled by particle diffusion due to collisions or a background of microturbulence. As expected from the theory of a stationary island, there exist cases where linearly stable magnetic perturbation are nonlinearly self-sustained. This situation corresponds to large poloidal beta and temperature gradient. The drive is due to diamagnetic frequency effects. However, this situation is not generic, and islands can also decay. It is found that a magnetic island is self-sustained for a negative off-diagonal diffusion coefficient. This case occurs in a tokamak if the inward particle pinch is due to the temperature gradient. (author)
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Directory of Open Access Journals (Sweden)
Jean Stubbs
2011-06-01
Full Text Available Review of: An Island Called Home: Returning to Jewish Cuba. Ruth Behar, photographs by Humberto Mayol. New Brunswick NJ: Rutgers University Press, 2007. xiii + 297 pp. (Cloth US$ 29.95 Fidel Castro: My Life: A Spoken Autobiography. Fidel Castro & Ignacio Ramonet. New York: Scribner/Simon & Schuster, 2008. vii + 724 pp. (Paper US$ 22.00, e-book US$ 14.99 Cuba: What Everyone Needs to Know. Julia E. Sweig. New York: Oxford University Press, 2009. xiv + 279 pp. (Paper US$ 16.95 [First paragraph] These three ostensibly very different books tell a compelling story of each author’s approach, as much as the subject matter itself. Fidel Castro: My Life: A Spoken Autobiography is based on a series of long interviews granted by the then-president of Cuba, Fidel Castro, to Spanish-Franco journalist Ignacio Ramonet. Cuba: What Everyone Needs to Know, by U.S. political analyst Julia Sweig, is one of a set country series, and, like Ramonet’s, presented in question/answer format. An Island Called Home: Returning to Jewish Cuba, with a narrative by Cuban-American anthropologist Ruth Behar and photographs by Cuban photographer Humberto Mayol, is a retrospective/introspective account of the Jewish presence in Cuba. While from Ramonet and Sweig we learn much about the revolutionary project, Behar and Mayol convey the lived experience of the small Jewish community against that backdrop.
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Broekman, J.A.
1974-01-01
A detailed analysis of the depositional and paleontological characteristics of a section of the Pliocene Kritika Formation on the island of Rhodos is presented. The environmental significance of sedimentary structures, the paleoecology of benthonic Foraminifera, and the sequentional
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Reliving Island Life: Staging Stories of the Blasket Islands
Directory of Open Access Journals (Sweden)
Daithí Kearney
2017-10-01
Full Text Available The Blasket Islands are located off the south-west coast of Ireland. No longer inhabited, the Great Blasket Island and its distinctive culture have been documented by a variety of writers and are celebrated today in an interpretative centre on the mainland and in performances by Siamsa Tíre, The National Folk Theatre of Ireland. “Siamsa” developed from local initiatives in North Kerry during the early 1960s and is located today in Tralee, Co. Kerry. It aims to present Irish folklore and folk culture through the medium of theatre involving music, song, dance and mime but invariably no dialogue. In this paper, I focus on the production Oiléan, based loosely on the stories of the Blasket Islanders, which was initially devised as part of the fiftieth anniversary commemoration of the departure of the last inhabitants of the islands in 2003.
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46 CFR 7.85 - St. Simons Island, GA to Little Talbot Island, FL.
2010-10-01
... 46 Shipping 1 2010-10-01 2010-10-01 false St. Simons Island, GA to Little Talbot Island, FL. 7.85... BOUNDARY LINES Atlantic Coast § 7.85 St. Simons Island, GA to Little Talbot Island, FL. (a) A line drawn from latitude 31°04.1′ N. longitude 81°16.7′ W. (St. Simons Lighted Whistle Buoy “ST S”) to latitude 30...
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Palaeoenvironment and shoreline displacement on Suursaari Island, the Gulf of Finland
Directory of Open Access Journals (Sweden)
Atko Heinsalu
2000-01-01
Full Text Available The island of Suursaari in the middle of the Gulf of Finland is exceptionally high (175 m a.s.l.. Sediment profiles from one mire and three lakes were investigated using diatom and pollen analysis, radiocarbon dating and levelling of the elevations of ancient shorelines. The pollen stratigraphy of the Lounatkorkiasuo Mire sediment suggests a sedimentary record dating from the late Allerød.The development of late-glacial vegetation went through the same phases as in southern Finland, however these are probably somewhat earlier on the island of Suursaari. There are differences in the Holocene vegetation history of the higher and lower areas of the island. Lake Ruokalahenjärvi was isolated around 10 000 BP during the initial phase of the Yoldia Sea and the diatom assemblage indicates that at that time brackish-water flow had not penetrated into the Gulfof Finland. Diatoms from the isolation sediments of Lake Liivalahenjärvi and Lake Veteljärvi indicate a freshwater environment for the Yoldia Sea final phase at 9500–9600 BP. Levelling of coastal formations on Suursaari Island reveals that the Late Weichselian and early Holocene ancient shorelines are 5–15 m higher than expected from the isobase data for similar land uplift areas on the mainland.The anomalous shoreline levels on Suursaari Island may be explained byirregular land uplift. By the time of the Litorina Sea differences in shoreline altitudes had disappeared.
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Adaptive radiation of island plants: Evidence from Aeonium (Crassulaceae) of the Canary Islands
DEFF Research Database (Denmark)
Jorgensen, T.H.; Olesen, J.M.
2001-01-01
evidence that such traits have been acquired through convergent evolution on islands comes from molecular phylogenies; however, direct evidence of their selective value rarely is obtained. The importance of hybridization in the evolution of island plants is also considered as part of a more general......The presence of diverse and species-rich plant lineages on oceanic islands is most often associated with adaptive radiation. Here we discuss the possible adaptive significance of some of the most prominent traits in island plants, including woodiness, monocarpy and sexual dimorphisms. Indirect...... discussion of the mechanisms governing radiations on islands. Most examples are from the Hawaiian and Canarian floras, and in particular from studies on the morphological, ecological and molecular diversification of the genus Aeonium, the largest plant radiation of the Canarian Islands....
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2002-01-01
Heron Island is located at the sourthern end of Australia's 2,050 km-long Great Barrier Reef. Surrounded by coral reef and home to over 1000 species of fish, scuba divers and scientists alike are drawn to the island's resort and research station. The true-color image above was taken by Space Imaging's Ikonos satellite with a resolution of 4 meters per pixel-high enough to see individual boats tied up at the small marina. The narrow channel leading from the marina to the ocean was blasted and dredged decades ago, before the island became a national park. Since then the Australian government has implemented conservation measures, such as limiting the number of tourists and removing or recycling, instead of incinerating, all trash. One of the applications of remote sensing data from Ikonos is environmental monitoring, including studies of coral reef health. For more information about the island, read Heron Island. Image by Robert Simmon, based on data copyright Space Imaging
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Ustica Island (Tyrrhenian Sea, Italy): from shoaling to emergent stage
Marinoni, L. B.; Pasquaré, G.; Vezzoli, L.
2003-04-01
Ustica is a volcanic island located in the southern Tyrrhenian sea, ~60 km NW of Sicily. As usual for volcanic ocean islands, its exposed part (8.6 km2, 248 m max elevation, mostly of Pleistocene age), is a small fraction of the whole edifice which rises from ~2000 m depth. Its 5-pointed-star shape is slightly elongated in a NE direction. A new geological field survey was carried out at scale 1:10000 and locally at 1:2000, establishing informal stratigraphic units that on the whole fit a common scheme of evolution for volcanic ocean islands. In this framework, the whole pre-existing stratigraphy has been revised. Ustica has a variety of volcanic deposits from submarine (basaltic effusive to explosive) to subaereal (effusive, explosive and highly explosive -Plinian?). Moreover, Ustica is one of the few places in the world where a transition of deposits from shoaling to emergent stage crop out. In fact, its oldest deposits consist of: (a) a flank-facies association of submarine lavas (variably-shaped pillows, pillow breccias and hyaloclastites) with biocalcarenite-biocalcirudite lenses, dipping coastward in the E, S and W outer parts of the island; this association is arranged in steep foreset beds (lava deltas) and is capped by flat-lying transitional to subaereal massive lava flows and surf-shaped boulder conglomerates; the geometry of this association may suggest a progressive island uplift or sea lowering during this period; (b) shallow-water to emergent tuff cone deposits in the NW part of the island. In the centre of the island, subsequent activity built a pile, now deeply eroded, of subaereal basaltic lava flows capped by a scoria cone. A previously unknown outcrop where a pumice fall layer is exposed, allows a distinction into two members of a unit that was known as formed by pyroclastic surges only. Higher in the succession, the Ustica Pumice formation (for which 4 members are defined) is underlain by a palaeosoil, and is likely the remnant of a caldera
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Cloud Formation, Sea-Air-Land Interaction, Mozambique, Africa
1991-01-01
This rare depiction of the physical interactions of air land and sea in cloud formation was seen over Mozambique (12.0S, 40.5E). Moist low air, heated as it moves over land, rises and forms clouds. Even the coastal islands have enough heat to initiate the process. Once begun, the circulation is dynamic and the descending motion suppresses cloud formation on either side of the cloud stream. As clouds move inland, they rise to follow the land upslope.
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Bryophytes from Simeonof Island in the Shumagin Islands, southwestern Alaska
Schofield, W.B.; Talbot, S. S.; Talbot, S.L.
2004-01-01
Simeonof Island is located south of the Alaska Peninsula in the hyperoceanic sector of the middle boreal subzone. We examined the bryoflora of Simeonof Island to determine species composition in an area where no previous collections had been reported. This field study was conducted in sites selected to represent the spectrum of environmental variation within Simeonof Island. Data were analyzed using published reports to compare bryophyte distribution patterns at three levels, the Northern Hemisphere, North America, and Alaska. A total of 271 bryophytes were identified: 202 mosses and 69 liverworts. The annotated list of species for Simeonof Island expands the known range for many species and fills distribution gaps within Hulte??n's Western Pacific Coast district. Maps and notes on the distribution of 14 significant distribution records are presented. Compared with bryophyte distribution in the Northern Hemisphere, the bryoflora of Simeonof Island primarily includes taxa of boreal (55%), temperate (20%), arctic (10%), and cosmopolitan (8%) distribution; 6% of the moss flora are western North America endemics. A description of the bryophytes present in the vegetation and habitat types is provided as is a quantitative analysis of the most frequently occurring bryophytes in crowberry heath.
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On the form of species–area relationships in habitat islands and true islands
DEFF Research Database (Denmark)
Matthews, Thomas J.; Guilhaumon, François; Triantis, Kostas A.
2016-01-01
and c vary between different island types. Location: Global. Methods: We used an information theoretic approach to compare the fit of 20 ISAR models to 207 habitat island datasets. Model performance was ranked according to pre-set criteria, including metrics of generality and efficiency. We also fitted......, and was the highest ranked model overall. In general, the more complex models performed badly. Average z-values were significantly lower for habitat island datasets than for true islands, and were higher for mountaintop and urban habitat islands than for other habitat island types. Average c-values were significantly...... multimodel comparisons demonstrated the nonlinear implementation of the power model to be the best overall model and thus to be a sensible choice for general use. As the z-value of the log–log power model varied in relation to ecological and geographical properties of the study systems, caution should...
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Groot, de Alma V.; Oost, Albert P.; Veeneklaas, Roos M.; Lammerts, Evert Jan; Duin, van Willem E.; Wesenbeeck, van Bregje K.
2016-01-01
The Frisian islands (Southern North Sea) have extensive island tails, i.e. the entire downdrift side of an island consisting of salt marshes, dunes, beaches and beach plains, and green beaches. Currently, large parts of these tails are ageing and losing dynamics, partly due to human influence.
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Blob Formation and Ejection in Coronal Jets due to the Plasmoid and Kelvin–Helmholtz Instabilities
Energy Technology Data Exchange (ETDEWEB)
Ni, Lei; Lin, Jun [Yunnan Observatories, Chinese Academy of Sciences, 396 Yangfangwang, Guandu District, Kunming, 650216 (China); Zhang, Qing-Min [Key Laboratory for Dark Matter and Space Science, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China); Murphy, Nicholas A., E-mail: leini@ynao.ac.cn [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
2017-05-20
We perform 2D resistive magnetohydrodynamic simulations of coronal jets driven by flux emergence along the lower boundary. The reconnection layers are susceptible to the formation of blobs that are ejected in the jet. Our simulation with low plasma β (Case I) shows that magnetic islands form easily and propagate upward in the jet. These islands are multithermal and thus are predicted to show up in hot channels (335 Å and 211 Å) and the cool channel (304 Å) in observations by the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory . The islands have maximum temperatures of 8 MK, lifetimes of 120 s, diameters of 6 Mm, and velocities of 200 km s{sup −1}. These parameters are similar to the properties of blobs observed in extreme-ultraviolet (EUV) jets by AIA. The Kelvin–Helmholtz instability develops in our simulation with moderately high plasma β (Case II) and leads to the formation of bright vortex-like blobs above the multiple high magnetosonic Mach number regions that appear along the jet. These vortex-like blobs can also be identified in the AIA channels. However, they eventually move downward and disappear after the high magnetosonic Mach number regions disappear. In the lower plasma β case, the lifetime for the jet is shorter, the jet and magnetic islands are formed with higher velocities and temperatures, the current-sheet fragments are more chaotic, and more magnetic islands are generated. Our results show that the plasmoid instability and Kelvin–Helmholtz instability along the jet are both possible causes of the formation of blobs observed at EUV wavelengths.
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International Nuclear Information System (INIS)
Bratic, S.; Krajacic, G.; Duic, N.; Cotar, A.; Jardas, D.
2011-01-01
In order to analyze energy self-sufficient island, example of a smaller island, connected to the power system of a bigger island with an undersea cable, was taken. Mounting substation 10/0,4 is situated on the island and for the moment it provides enough electricity using the medium voltage line. It is assumed that the island is situated on the north part of the Adriatic Sea. The most important problem that occurs on the island is the population drop that occurs for a significant number of years, therefore, life standard needs to be improved, and economic development needs to be encouraged immediately. Local authorities to stimulate sustainable development on the island through different projects, to breath in a new life to the island, open new jobs and attract new people to come live there. Because of the planned development and increase of the population, energy projects, planned as a support to sustainable development, and later achievement of the energy self-sufficiency, is described in this paper. Therefore, Rewisland methodology appliance is described taking into the account three possible scenarios of energy development. Each scenario is calculated until year 2030. Also, what is taken into the account is 100% usage of renewable sources of energy in 2030. Scenario PTV, PP, EE - This scenario includes installation of solar photovoltaic modules and solar thermal collectors on the buildings roofs, as well as well as implementation of energy efficiency on the island (replacement of the street light bulbs with LED lightning, replacement of the old windows and doors on the houses, as well as the installation of the thermal insulation). Scenario PV island - This scenario, similarly to the previous one, includes installation of solar photovoltaic modules and solar thermal collectors an the residential buildings, as well as the 2 MW photovoltaic power plant and ''Green Hotel'', a building that satisfies all of its energy needs completely from renewable energy sources
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Intensity of Urban Heat Islands in Tropical and Temperate Climates
Directory of Open Access Journals (Sweden)
Margarete Cristiane de Costa Trindade Amorim
2017-12-01
Full Text Available Nowadays, most of the Earth’s population lives in urban areas. The replacement of vegetation by buildings and the general soil sealing, associated with human activity, lead to a rise in cities temperature, resulting in the formation of urban heat islands. This article aims to evaluate the intensity and the hourly maintenance of the atmospheric heat islands in two climates: one tropical (Presidente Prudente, Brazil and one temperate (Rennes, France throughout 2016. For this, air temperature and hourly averages were measured and calculated using both a HOBO datalogger (U23-002—protected under the same RS3 brand and weather stations Davis Vantage PRO 2. The daily evolution of the heat islands presented characteristics that varied according to the hours and seasons of the year. For both Rennes and Presidente Prudente, the largest magnitudes occurred overnight, being more greatly expressed in the tropical environment and during the driest months (winter in the tropical city and summer in the temperate one. The variability of synoptic conditions from one month to another also leads to a great heterogeneity of UHI intensity throughout the year.
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One million served: Rhode Island`s recycling facility
Energy Technology Data Exchange (ETDEWEB)
Malloy, M.G.
1997-11-01
Rhode Island`s landfill and adjacent materials recovery facility (MRF) in Johnston, both owned by the quasi-public Rhode Island Resource Recovery Corp. (RIRRC, Johnston), serve the entire state. The $12-million recycling facility was built in 1989 next to the state`s sole landfill, the Central Landfill, which accepts only in-state trash. The MRF is operated for RIRRC by New England CRInc. (Hampton, N.H.), a unit of Waste Management, Inc. (WMI, Oak Brook, Ill.). It handles a wide variety of materials, from the usual newspaper, cardboard, and mixed containers to new streams such as wood waste, scrap metal, aseptic packaging (milk and juice boxes), and even textiles. State municipalities are in the process of adding many of these new recyclable streams into their curbside collection programs, all of which feed the facility.
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Immigrants, islandness and perceptions of quality-of-life on Prince Edward Island, Canada
Directory of Open Access Journals (Sweden)
Peter Kitchen
2014-11-01
Full Text Available This paper explores perceptions of immigrant quality-of-life (QOL and islandness in Charlottetown, Prince Edward Island, Canada, and compares these perceptions to those of Canadian-born residents of the same provincial capital. The study employed a mixed-methods approach, including a household telephone survey conducted in the summer of 2012 (n=302, focus group interviews with immigrants in late 2012 and observations on preliminary results by the staff of the PEI Association of Newcomers to Canada (PEIANC, the primary immigrant settlement service agency on the island. The analysis of the results suggests that immigrants have a high and undifferentiated assessment of their own QOL, sense of belonging and sense of place compared to Canadian-born islanders; immigrants are also critical of the quality of education and of the range of recreational and cultural events underway on the Island. While they express positive sentiments regarding life on the Island, immigrants still feel excluded from social and economic opportunities.
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Water in St. John, U.S. Virgin Islands
Cosner, O.J.
1972-01-01
Water for domestic and municipal supply on St. John, in the past, has been obtained from rain catchments, dug wells, and barge shipments from St. Thomas and Puerto Rico. As a result of this study, small ground-water supplies have been developed for the Virgin Islands National Park. Ground water occurs in significant but limited quantities in the fractured volcanic rock throughout most of the Island. Yield of wells in this aquifer ranges from less than 100 to about 2,000 gpd (gallons per day). The average long-term yield of the three drilled wells in use by the National Park Service in 1967 was about 1,000 gpd. Yield ofl,000 to 5,000 gpd may be expected in the Coral Bay and the Reef Bay areas. Estimated total recharge of the fractured volcanic rock on St. John, based on a recharge of 1 to 3 inches per year, is 1,000,000 to 3,000,000 gpd. Perhaps as much as a quarter to a third of this water could be developed practically, depending on the rainfall in a given year. The chemical quality of the ground water in the fractured-rock aquifer in areas uncontaminated by sea water ranges from 600 to 2,000 mg/l (milligrams per liter) or more dissolved solids. Water from-formations in the higher altitudes is of better quality than that in the lower formations. Small quantities of ground water are available from beach sand, alluvium, and fractured rock near the sea. However, these sources tend to be brackish and are subject to salt-water encroachment. There are no perennial streams on St. John. There are a few spring-fed pools in stream channels, however, that are sustained, except in severe drought. Storm runoff is estimated to average 1 inch over the island annually, and evaporation from open water surfaces is about 70 inches per year. Ponds can be developed, but because of the high .evaporation they may be unreliable during droughts. Rain water collected in cisterns from roofs and catchments yield about 50 gpd per 1,000 square feet of catch area during an average year of
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Pathogenicity island mobility and gene content.
Energy Technology Data Exchange (ETDEWEB)
Williams, Kelly Porter
2013-10-01
Key goals towards national biosecurity include methods for analyzing pathogens, predicting their emergence, and developing countermeasures. These goals are served by studying bacterial genes that promote pathogenicity and the pathogenicity islands that mobilize them. Cyberinfrastructure promoting an island database advances this field and enables deeper bioinformatic analysis that may identify novel pathogenicity genes. New automated methods and rich visualizations were developed for identifying pathogenicity islands, based on the principle that islands occur sporadically among closely related strains. The chromosomally-ordered pan-genome organizes all genes from a clade of strains; gaps in this visualization indicate islands, and decorations of the gene matrix facilitate exploration of island gene functions. A %E2%80%9Clearned phyloblocks%E2%80%9D method was developed for automated island identification, that trains on the phylogenetic patterns of islands identified by other methods. Learned phyloblocks better defined termini of previously identified islands in multidrug-resistant Klebsiella pneumoniae ATCC BAA-2146, and found its only antibiotic resistance island.
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Directory of Open Access Journals (Sweden)
Kenji Suetsugu
2014-12-01
Full Text Available We found Gastrodia fontinalis T. P. Lin in a bamboo forest from Takeshima Island, which is the northernmost island of the Ryukyu Islands in Japan. This species is apparently rare and was previously considered to be an endemic Taiwanese species. Because there are a few minor differences between the original description and our specimens collected in Takeshima Island, here we report Gastrodia fontinalis from Takeshima Island as the first record outside of Taiwan, with a description of the specimens from Takeshima Island.
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Renewable energy islands in Europe
Energy Technology Data Exchange (ETDEWEB)
Oestergaard, Iben [ed.
1998-12-31
This publication includes a compiled presentation of various aspects concerning the possible transformation of some European islands into renewable energy communities and these projects were presented by a selection of pioneer islands at the first European Seminar on Renewable Energy Islands, held on the Danish island of Samsoee, 29-30 June 1998. This issue has increased in importance with the presentation of the ambitious EU-White Paper: `Energy for the future: Renewable Sources of Energy` which was adopted in 1998. One of the key elements of the strategy for an accelerated implementation of renewable energy is to transform 100 localities within Europe into communities which are to be 100% self-sufficient with renewable energy before 2010. In line with this strategy, the Danish Government appointed the island of Samsoe towards the end of 1997 to be the first `official` Danish, renewable energy island. This is to serve as a demonstration project for other local communities, both in Denmark as well as in the rest Europe. Gothland, Madeira, Canary Islands, Cape Verde, Arki, Crete, Minorca and Orkney Islands were represented. Environmental advantages of wind, solar and wave power for distant island communities were indicated. Serious savings would be achieved by limitation of fossil fuel import and utilization of local resources. (EG)
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Computational problems in Arctic Research
International Nuclear Information System (INIS)
Petrov, I
2016-01-01
This article is to inform about main problems in the area of Arctic shelf seismic prospecting and exploitation of the Northern Sea Route: simulation of the interaction of different ice formations (icebergs, hummocks, and drifting ice floes) with fixed ice-resistant platforms; simulation of the interaction of icebreakers and ice- class vessels with ice formations; modeling of the impact of the ice formations on the underground pipelines; neutralization of damage for fixed and mobile offshore industrial structures from ice formations; calculation of the strength of the ground pipelines; transportation of hydrocarbons by pipeline; the problem of migration of large ice formations; modeling of the formation of ice hummocks on ice-resistant stationary platform; calculation the stability of fixed platforms; calculation dynamic processes in the water and air of the Arctic with the processing of data and its use to predict the dynamics of ice conditions; simulation of the formation of large icebergs, hummocks, large ice platforms; calculation of ridging in the dynamics of sea ice; direct and inverse problems of seismic prospecting in the Arctic; direct and inverse problems of electromagnetic prospecting of the Arctic. All these problems could be solved by up-to-date numerical methods, for example, using grid-characteristic method. (paper)
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Barrier island habitat map and vegetation survey—Dauphin Island, Alabama, 2015
Enwright, Nicholas M.; Borchert, Sinéad M.; Day, Richard H.; Feher, Laura C.; Osland, Michael J.; Wang, Lei; Wang, Hongqing
2017-08-04
Barrier islands are dynamic environments due to their position at the land-sea interface. Storms, waves, tides, currents, and relative sea-level rise are powerful forces that shape barrier island geomorphology and habitats (for example, beach, dune, marsh, and forest). Hurricane Katrina in 2005 and the Deep Water Horizon oil spill in 2010 are two major events that have affected habitats and natural resources on Dauphin Island, Alabama. The latter event prompted a collaborative effort between the U.S. Geological Survey, the U.S. Army Corps of Engineers, and the State of Alabama funded by the National Fish and Wildlife Foundation to investigate viable, sustainable restoration options that protect and restore the natural resources of Dauphin Island, Alabama.In order to understand the feasibility and sustainability of various restoration scenarios, it is important to understand current conditions on Dauphin Island. To further this understanding, a detailed 19-class habitat map for Dauphin Island was produced from 1-foot aerial infrared photography collected on December 4, 2015, and lidar data collected in January 2015. We also conducted a ground survey of habitat types, vegetation community structure, and elevations in November and December 2015. These products provide baseline data regarding the ecological and general geomorphological attributes of the area, which can be compared with observations from other dates for tracking changes over time.
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33 CFR 80.712 - Morris Island, SC to Hilton Head Island, SC.
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Morris Island, SC to Hilton Head..., SC to Hilton Head Island, SC. (a) A line drawn from the easternmost tip of Folley Island to the... easternmost extremity of Hilton Head at latitude 32°13.0′ N. longitude 80°40.1′ W. [CGD 77-118a, 42 FR 35784...
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Island dynamics and Minoan expansion in the Aegean: the Kythera Island Project
Directory of Open Access Journals (Sweden)
Cyprian Broodbank
1999-11-01
Full Text Available In recent years archaeologists have become increasingly interested in the investigation of island societies. At a global level, discoveries in the Pacific, Caribbean, Mediterranean and elsewhere have greatly improved our understanding of the antiquity and dynamics of island life. Now archaeologists at the Institute, together with other colleagues, have embarked on a long-term interdisciplinary study of the island of Kythera in the Aegean.
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Nonlinear mechanism for the suppression of error field magnetic islands by plasma flow
International Nuclear Information System (INIS)
Parker, R.D.
1992-01-01
Non-axisymmetric magnetic field perturbations generated, for example, by errors in the alignment of the field coils are known to lead to reduced confinement in a tokamak. By inducing the formation of small, stationary, magnetic islands on all rational surfaces they can enhance radial transport and under certain circumstances interact with MHD instabilities to trigger the onset of locked modes leading, in some cases, to disruption of the plasma discharge. Given the stationary nature of the error field islands it is natural to consider whether they can be reduced significantly by the viscous drag of a sheared flow resulting from a bulk rotation of the plasma. In this paper, we examine this interaction by modelling the nonlinear growth and saturation of force-reconnected magnetic islands driven by a corrugated boundary in a slab plasma with an initially uniform flow. A systematic parameter study is made of the time asymptotic steady state. (author) 3 figs., 5 refs
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Directory of Open Access Journals (Sweden)
J. P. Roux
1992-10-01
Full Text Available The physiography and climate of Inaccessible and Nightingale Islands are briefly discussed. The vegetation and the major plant associations are described. Notes are given on the ecology and distribution of each taxon. Taxa newly recorded for Inaccessible Island include Agrostis goughensis, A.holgateana, A. wacei, Calamagrostis deschampsiiformis, Carex thouarsii var. recurvata, Conyza albida, Elaphoglossum campylolepium and Uncinia meridensis. One species, C. albida, is alien to the Tristan group. Two native ferns Asplenium platybasis var. subnudum and Blechnum australe were found on Nightingale Island for the first time, and the presence of introduced Malus domestica orchards was recorded. Two unidentified taxa were found that may represent new species: Elaphoglossum sp. at Inaccessible Island and Apium sp. at both Inaccessible and Nightingale Islands. The total number of vascular plant species recorded at Inaccessible and Nightingale Islands now stands at 98 and 43, respectively, of which 26 (28% and seven (16% are introduced species. Only Airiplex plebeja and two species of Cotula occur at Nightingale Island but are absent from Inaccessible Island.
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World Bank
2015-01-01
This note aims to build understanding of the existing disaster risk financing and insurance (DRFI) tools in use in The Marshall Islands and to identify gaps where potential engagement could further develop financial resilience. The likelihood that a hazardous event will have a significant impact on the Marshall Islands has risen with the increasing levels of population and assets in the urban ...
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A man and his island: The island mirror in Michael Crummey’s Sweetland
Directory of Open Access Journals (Sweden)
Laurie Brinklow
2016-05-01
Full Text Available Between 1946 and 1975, dozens of islands and outports in the Canadian province of Newfoundland and Labrador were abandoned as part of a government resettlement policy. Families and communities were torn apart, and a culture and way of life that revolved around the fishery changed irrevocably. The practice, which continues to this day, has been well documented, particularly by artists and writers. Michael Crummey’s 2014 novel Sweetland is a recent iteration. The relationship between humans and place is complex: on an island, with compressed space and a very real boundary that is the ocean, emotional attachments to one’s place are often heightened and distilled. What happens when a person is displaced from his or her island; when bonds of attachment are severed and one’s mirrored double is destroyed? Sweetland offers a fictional lens through which we see an example of a mirrored relationship between an island protagonist and his island setting. Exploring themes of attachment to place, and what Barry Lopez calls a “storied” or “reciprocal” relationship with the land, this paper examines what happens to a man when confronted with leaving an island he knows as deeply as his own body and soul; and how the island reacts.
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Island development: Local governance under globalization
Directory of Open Access Journals (Sweden)
Huei-Min Tsai
2014-12-01
Full Text Available Issues surrounding island development have generated a growing volume of research. What does it mean to develop? How can island communities maintain control over development processes to the benefit of the local economy, rather than seeing economic flows enter and exit the island with little or a primarily negative impact? And how important is local knowledge for edifying local governance and enhancing potentials for innovation in island development? Island histories have repeatedly been forwarded as exemplars and ‘lessons’ for global learning on (unsustainability. To consider these issues, we have selected a number of papers from among the presentations given at the International Geographical Union’s Commission on Islands Conference, Island Development: Local Economy, Culture, Innovation and Sustainability, which took place in the Penghu Archipelago, Taiwan, 1–5 October 2013. These papers serve as examples of how the processes of globalization have penetrated the borders and changed the political and economic structures of islands. They also explore how island-based innovations in science, technology, culture, and formal or informal governance might contribute to sustainable island development.
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Modern sedimentation patterns in Potter Cove, King George Island, Antarctica
Hass, H. Christian; Kuhn, Gerhard; Wölfl, Anne-Cathrin; Wittenberg, Nina; Betzler, Christian
2013-04-01
IMCOAST among a number of other initiatives investigates the modern and the late Holocene environmental development of south King George Island with a strong emphasis on Maxwell Bay and its tributary fjord Potter Cove (maximum water depth: about 200 m). In this part of the project we aim at reconstructing the modern sediment distribution in the inner part of Potter Cove using an acoustic ground discrimination system (RoxAnn) and more than136 ground-truth samples. Over the past 20 years the air temperatures in the immediate working area increased by more than 0.6 K (Schloss et al. 2012) which is less than in other parts of the West Antarctic Peninsula (WAP) but it is still in the range of the recovery of temperatures from the Little Ice Age maximum to the beginning of the 20th century. Potter Cove is a small fjord characterized by a series of moraine ridges produced by a tidewater glacier (Fourcade Glacier). Presumably, the farthest moraine is not much older than about 500 years (LIA maximum), hence the sediment cover is rather thin as evidenced by high resolution seismic data. Since a few years at least the better part of the tidewater glacier retreated onto the island's mainland. It is suggested that such a fundamental change in the fjord's physiography has also changed sedimentation patterns in the area. Potter Cove is characterized by silty-clayey sediments in the deeper inner parts of the cove. Sediments are coarser (fine to coarse sands and boulders) in the shallower areas; they also coarsen from the innermost basin to the mouth of the fjord. Textural structures follow the seabed morphology, i.e. small v-shaped passages through the moraine ridges. The glacier still produces large amounts of turbid melt waters that enter the cove at various places. We presume that very fine-grained sediments fall out from the meltwater plumes and are distributed by mid-depth or even bottom currents, thus suggesting an anti-estuarine circulation pattern. Older sediments that are
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Lin, N.; Walker, R. J.; Mcpherron, R. L.; Kivelson, M. G.
1990-01-01
During the 1054 UT CDAW 6 substorm event, two ISEE spacecraft observed dynamic changes in the magnetic field and in the flux of energetic particles in the near-earth plasma sheet. In the substorm growth phase, the magnetic field at both ISEE spacecraft became tail-like. Following expansion phase onset, two small scale magnetic islands were observed moving tailward at a velocity of about 580 km/s. The passage of these two magnetic islands was coincident with bursts of tailward streaming energetic particles. The length of the magnetic loops was estimated to have been about 2 to 3 earth radii while the height of the loops was less than 0.5 earth radii. The magnetic islands were produced by multipoint reconnection processes in the near tail plasma sheet which may have been associated with the formation of the near-earth neutral line and the subsequent formation of a large scale plasmoid. The near-earth neutral line retreated tailward later in the expansion phase, as suggested by the reversal of the streaming of energetic particles.
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Energy Transition Initiative, Island Energy Snapshot - British Virgin Islands (Fact Sheet)
Energy Technology Data Exchange (ETDEWEB)
2015-03-01
This profile provides a snapshot of the energy landscape of the British Virgin Islands (BVI), one of three sets of the Virgin Island territories in an archipelago making up the northern portion of the Lesser Antilles.
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Demographic Ageing on Croatian Islands
Directory of Open Access Journals (Sweden)
Ivo Nejašmić
2013-08-01
Full Text Available This paper analyses the changes in the population structure of the Croatian islands by age, warns of the degree of ageing, provides spatial differentiation of this process and presents perspective of ageing at the level of settlement. Typing of population ageing is based on scores and has seven types. The total island population in 2011 belongs to the type 5 – very old population. Almost a half of the settlements (out of 303 have been affected by the highest levels of ageing (types 6 and 7. It was found that a quarter of island settlements will become “dead villages” in a foreseeable future; most of them are on small islands but also in the interior of larger islands. These are villages decaying in every respect, in which the way of life, as we know it, veins and goes out. The present ageing villagers are their last residents in most cases. Eve¬rything suggests that demographic recovery of the islands is not possible with the forces in situ. It is important to strike a balance between the needs and opportunities in order to successfully organize life on the islands, both small and large ones, and the fact is that there is a continuing disparity, which is especially profound in small islands. A sensitive and selective approach is needed to overcome the unfavourable demographic trends. Therefore it is necessary to respect the particularities of indi¬vidual islands and island groups in devising development strategy. Solutions to the problems must come of the local and wider community in synergy with relevant professional and scientific institutions. However, if the solutions are not found or measures do not give results, if the islands are left to desorganisation and senilisation, a part of the islands will become a wasteland. With regard to the value of this area whose wealth are people in the first place, this would be an intolerable civilization decline.
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The Island Smart Energy System and Market
DEFF Research Database (Denmark)
Ma, Zheng; Billanes, Joy Dalmacio; Jørgensen, Bo Nørregaard
2017-01-01
developing island smart energy systems with the integration of renewable energy resources can increase the energy supply and address the global island energy issues. The island smart energy system operates either in a single-island or in multi-islands. However the island characteristics and influ...
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Terrestrial bird population trends on Aguiguan (Goat Island), Mariana Islands
Amidon, Fred; Camp, Richard J.; Marshall, Ann P.; Pratt, Thane K.; Williams, Laura; Radley, Paul; Cruz, Justine B.
2014-01-01
The island of Aguiguan is part of the Mariana archipelago and currently supports populations of four endemic species, including one endemic genus, Cleptornis. Bird population trends since 1982 were recently assessed on the neighbouring islands of Saipan, Tinian, and Rota indicating declines in some native species. Point-transect surveys were conducted in 2008 by the U.S. Fish and Wildlife Service to assess population densities and trends on Aguiguan. Densities for six of the nine native birds—White-throated Ground-dove Gallicolumba xanthonura, Collared Kingfisher Todiramphus chloris, Rufous Fantail Rhipidura rufifrons, Golden White-eye Cleptornis marchei, Bridled White-eye Zosterops conspicillatus and Micronesian Starling Aplonis opaca—and the non-native bird—Island Collared-dove Streptopelia bitorquata—were significantly greater in 2008 than in 1982. No differences in densities were detected among the surveys for Mariana Fruit-dove Ptilinopus roseicapilla, and Micronesian MyzomelaMyzomela rubratra. Three federally and locally listed endangered birds—Nightingale Reed-warbler Acrocephalus luscinius, Mariana Swiftlet Collocalia bartschi, and Micronesian Megapode Megapodius laperous)—were either not detected during the point-transect counts, the surveys were not appropriate for the species, or the numbers of birds detected were too small to estimate densities. The factors behind the increasing trends for some species are unknown but may be related to increased forest cover on the island since 1982. With declining trends for some native species on neighbouring islands, the increasing and stable trends on Aguiguan is good news for forest bird populations in the region, as Aguiguan populations can help support conservation efforts on other islands in the archipelago.
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Self-assembled nano-patterns in strained 2D metalic alloys: stripes vs. islands
Czech Academy of Sciences Publication Activity Database
Kotrla, Miroslav; Weber, S.; Much, F.; Biehl, M.; Kinzel, W.
2007-01-01
Roč. 13, - (2007), s. 70-75 ISSN 1335-1532 EU Projects: European Commission(XE) 16447 - MAGDOT Grant - others:NSF DMR Award(DE) 0502737 Institutional research plan: CEZ:AV0Z10100520 Keywords : nanoscale pattern formation * selfassembly * coarsening of 2D islands * metalic alloys * misfit-induced strain * computer modeling and simulation. Subject RIV: BM - Solid Matter Physics ; Magnetism
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Mendoza Vizcaino, Javier; Sumper, Andreas; Sudrià Andreu, Antoni; Ramirez, J.M.
2016-01-01
The electric generation systems on islands are based generally on fossil fuel. This fact and its supply make the electricity cost higher than in systems used in the continent. In this article, we present a review of the renewable energy generation systems on islands. To do it we analysed 77 islands from 45 different countries. This work will allow us to know how the implementation of renewable energy sources could help these islands in developing a renewable and sustainable energy sector, inc...
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CRED Gridded Bathymetry near Laysan Island (100-006), Northwestern Hawaiian Islands
National Oceanic and Atmospheric Administration, Department of Commerce — File 100-006b is a 60-m ASCII grid of depth data collected near Laysan Island in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced as...
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CRED Gridded Bathymetry near Lisianski Island (100-001), Northwestern Hawaiian Islands
National Oceanic and Atmospheric Administration, Department of Commerce — File 100-001b is a 60-m ASCII grid of depth data collected near Lisianski Island in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced as...
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75 FR 61993 - Amendment of Class E Airspace; Kwajalein Island, Marshall Islands, RMI
2010-10-07
...This action removes the reference to the Kwajalein Tactacial Air Navigation (TACAN) System from the legal description of the Class E airspace areas for Kwajalein Island, Bucholz AAF, Marshall Islands, RMI. The U.S. Army notified the FAA that the Kwajalein TACAN was decommissioned. This action corrects the legal descriptions for the Class E airspace areas in the vicinity of the Marshall Islands.
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Dating the magmatism of Maio, Cape Verde Islands
Energy Technology Data Exchange (ETDEWEB)
Mitchell, J G [Newcastle upon Tyne Univ. (UK). School of Physics; Le Bas, M J [Leicester Univ. (UK). Dept. of Geology; Furnes, H [Bergen Univ. (Norway). Geologisk Inst.
1983-07-01
Conventional K-Ar and /sup 40/Ar//sup 39/Ar studies of Mesozoic ocean floor basalts and Tertiary plutonic and volcanic rocks from Maio, Cape Verde Islands, have been determined to elucidate the magmatic evolution of this ocean island. Pillow lavas of the Basement Complex yield a minimum age of 113 +- 8 Ma though thermal overprinting of their formation age by the younger Central Intrusive Complex (CIC) and subsequent sheet intrusions is in some cases almost total. Activity in the CIC began before 20 Ma and plutons continued to develop until about 8 Ma, the youngest ages possibly indicating a cooling history of more than 2 Ma for these bodies relative to their volcanic counterparts. Sheet intrusion occurred throughout the period 20 to 9 Ma though the peak of this activity probably occurred 11 Ma ago. Field relations allow the time of thrusting(s) on the Monte Branco Thrust to be bracketed between 9 and 7 Ma. Volcanic activity began in the Tertiary, probably before 12 Ma, and culminated in the development of a stratovolcano at 7 Ma.
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Verzhbitsky, V. E.
2003-04-01
This study is based on the field works carried out by the Institute of the Lithosphere of Marginal Seas RAS in the central part of the Bel'kovsky island during 2002 August-September. In the tectonic sense the Bel'kovsky island is located in the eastern part of the Late Cretaceous (?) - Cenozoic Laptev Sea rift system and also is a part of extended Bel’kov horst, dividing Bel’kov Svyatoi Nos (in the east) and Anisin (in the west) rifts (e.g. Drachev et al, 1998). Mesostructural investigations included statistical measurments of kinematic indicators (cleavage planes, extensional veins, slickensides, axes of folds and bedding plains) in Devonian and Carboniferous sedimentary formations and also slickensides in diabase magmatic complex (presumably of Late Paleozoic age). It is supposed, that this studies will allow to characterize the stages of regional tectonic processes: synsedimentary (slump) folds formation (1), NE-SW compression (2), which corresponds to the general (NW-SE trending) structural pattern of the island, E-W compression (3), expressed in N-S trending subvertical cleavage and associated strike-slips and thrust faults, NW-SE (4) and ENE-WSW - NE-SW (5) extension, expressed in strike-slip faults with different strike-slip component, and also, probably to specify the character of the recent tectonic processes near to the area of conjunction between the Eurasian and American plates. It is likely, that synsedimentary (slump) folds, identified in the Carboniferous clastic formation marks the paleoslope setting of New Siberian Islands Chukotka platform (block). Presumably, second of the determined stages corresponds to closing of the South Anyui Lyakhov paleooceanic basin in Neocomian; the last stage, expressed in wide-developed submeridional normal faults with sinistral strike-slip component along the western coast of the island, reflects the modern regional stress-field in area of conjunction between the Eurasian and American plates (e.g. Avetisov, 1999
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Returning from the Horizon: Introducing Urban Island Studies
Directory of Open Access Journals (Sweden)
Xavier Barceló Pinya
2015-12-01
Full Text Available Island studies tends to focus on peripheral, isolated, and marginal aspects of island communities, while urban studies has showed scant awareness of islandness: Although many people research cities on islands, there is little tradition of researching island cities or urban archipelagos per se. Island cities (densely populated small islands and population centres of larger islands and archipelagos nevertheless play import cultural, economic, political, and environmental roles on local, regional, and global scales. Many major cities and ports have developed on small islands, and even villages can fulfil important urban functions on lightly populated islands. Island concepts are also deployed to metaphorically describe developments in urban space. The journal Urban Island Studies explores island and urban processes around the world, taking an island approach to urban research and an urban approach to island research.
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Gridded multibeam bathymetry of Howland Island, Pacific Remote Island Areas, Central Pacific
National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry at 40m resolution surrounding Howland Island, within the Pacific Remote Island Areas - Central Pacific Ocean. Bottom coverage was achieved in...
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González, Diego Luis; Pimpinelli, Alberto; Einstein, T. L.
2017-07-01
We study the effect of hindered aggregation on the island formation process in a one- (1D) and two-dimensional (2D) point-island model for epitaxial growth with arbitrary critical nucleus size i . In our model, the attachment of monomers to preexisting islands is hindered by an additional attachment barrier, characterized by length la. For la=0 the islands behave as perfect sinks while for la→∞ they behave as reflecting boundaries. For intermediate values of la, the system exhibits a crossover between two different kinds of processes, diffusion-limited aggregation and attachment-limited aggregation. We calculate the growth exponents of the density of islands and monomers for the low coverage and aggregation regimes. The capture-zone (CZ) distributions are also calculated for different values of i and la. In order to obtain a good spatial description of the nucleation process, we propose a fragmentation model, which is based on an approximate description of nucleation inside of the gaps for 1D and the CZs for 2D. In both cases, the nucleation is described by using two different physically rooted probabilities, which are related with the microscopic parameters of the model (i and la). We test our analytical model with extensive numerical simulations and previously established results. The proposed model describes excellently the statistical behavior of the system for arbitrary values of la and i =1 , 2, and 3.
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Agarwal, Arun; Agarwal, Aakanksha
2017-10-01
Hemophagocytic lymphohistiocytosis (HLH) is a rare, underdiagnosed, fatal and devastating hyperinflammatory syndrome that has gained increasing recognition over the past decade. Patients with HLH present with clinical and laboratory evidence of uncontrolled inflammation. Delay in diagnosis and management inevitably leads to a rapidly progressive and fatal course. In this case series, we present 7 cases of secondary HLH (sHLH) in adults with their presentation, course, and outcomes. We retrospectively looked at the 7 cases of secondary HLH who were diagnosed and managed in our institute between January 2013 and august 2015. Medical records were retrieved from medical records department and data analyzed and tabulated. The median age at diagnosis was 35 years (age range 26-72 years). Diagnosis was based on HLH 2004 diagnostic criteria. We report profile of 7 adult patients with sHLH. All patients had a short history of illness (<2 weeks) and presented uniformly with prolonged fever, bi or trilineage cytopenia and multiorgan dysfunction syndrome (MODS) at admission or developed MODS during the course of their illness. None of them had prediagnosed HLH. All patients fulfilled 5 to 6 of 8 criteria as per HLH 2014 diagnostic criteria. The median length of hospital stay was 12 days (range 7-50 days) and the median time to diagnosis was 5 days (range 3 to 21 days). Mortality was 57%. HLH is a rare and under-diagnosed clinical syndrome and is rapidly fatal if not diagnosed and managed timely. The cases reported in literature probably represent a tip of an iceberg of large number of undiagnosed cases mostly labeled as sepsis with MODS in critical care units. sHLH should be suspected in any patient who present with persistent and prolonged fever, transaminitis, cytopenia, and high serum Ferritin or dramatically rising serial serum Ferritin. Early diagnosis and prompt aggressive treatment are vital for patients' survival and favorable outcome.
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Energy Technology Data Exchange (ETDEWEB)
Hoke, Anderson [National Renewable Energy Lab. (NREL), Golden, CO (United States); Nelson, Austin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, Brian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chakraborty, Sudipta [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bell, Frances [SolarCity, San Mateo, CA (United States); McCarty, Michael [SolarCity, San Mateo, CA (United States)
2016-07-01
As PV and other DER systems are connected to the grid at increased penetration levels, island detection may become more challenging for two reasons: 1.) In islands containing many DERs, active inverter-based anti-islanding methods may have more difficulty detecting islands because each individual inverter's efforts to detect the island may be interfered with by the other inverters in the island. 2.) The increasing numbers of DERs are leading to new requirements that DERs ride through grid disturbances and even actively try to regulate grid voltage and frequency back towards nominal operating conditions. These new grid support requirements may directly or indirectly interfere with anti-islanding controls. This report describes a series of tests designed to examine the impacts of both grid support functions and multi-inverter islands on anti-islanding effectiveness. Crucially, the multi-inverter anti-islanding tests described in this report examine scenarios with multiple inverters connected to multiple different points on the grid. While this so-called 'solar subdivision' scenario has been examined to some extent through simulation, this is the first known work to test it using hardware inverters. This was accomplished through the use of power hardware-in-the-loop (PHIL) simulation, which allows the hardware inverters to be connected to a real-time transient simulation of an electric power system that can be easily reconfigured to test various distribution circuit scenarios. The anti-islanding test design was a modified version of the unintentional islanding test in IEEE Standard 1547.1, which creates a balanced, resonant island with the intent of creating a highly challenging condition for island detection. Three common, commercially available single-phase PV inverters from three different manufacturers were tested. The first part of this work examined each inverter individually using a series of pure hardware resistive-inductive-capacitive (RLC
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Gridded multibeam bathymetry of Baker Island, Pacific Remote Island Areas, Central Pacific
National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry at 40m resolution surrounding Baker Island, within the Pacific Remote Island Areas - Central Pacific Ocean. Bottom coverage was achieved in depths...
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Predictions of barrier island berm evolution in a time-varying storm climatology
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.
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Vegetation assessment of forests of Pagan Island, Commonwealth of the Northern Mariana Islands
Pratt, Linda W.
2011-01-01
As part of the Marianas Expedition Wildlife Surveys-2010, the forest vegetation of the island of Pagan, Commonwealth of the Northern Mariana Islands (CNMI), was sampled with a series of systematic plots along 13 transects established for monitoring forest bird populations. Shrubland and grassland were also sampled in the northern half of the island. Data collected were woody plant density, tree diameter at breast height, woody plant density in height classes below 2 m, and ground cover measured with the point-intercept method. Coconut forests (Cocos nucifera) were generally found to have low native tree diversity, little regeneration of trees and shrubs in the forest understory, and little live ground cover. The sole exception was a coconut-dominated forest of the northeast side of the island that exhibited high native tree diversity and a large number of young native trees in the understory. Ironwood (Casuarina equisetifolia) forests on the northern half of the island were nearly monocultures with almost no trees other than ironwood in vegetation plots, few woody plants in the understory, and low ground cover dominated by native ferns. Mixed native forests of both northern and southern sections of the island had a diversity of native tree species in both the canopy and the sparse understory. Ground cover of native forests in the north had a mix of native and alien species, but that of the southern half of the island was dominated by native ferns and woody plants.
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Island biogeography of marine organisms
Pinheiro, Hudson T.; Bernardi, Giacomo; Simon, Thiony; Joyeux, Jean-Christophe; Macieira, Raphael M.; Gasparini, João Luiz; Rocha, Claudia; Rocha, Luiz A.
2017-09-01
Studies on the distribution and evolution of organisms on oceanic islands have advanced towards a dynamic perspective, where terrestrial endemicity results from island geographical aspects and geological history intertwined with sea-level fluctuations. Diversification on these islands may follow neutral models, decreasing over time as niches are filled, or disequilibrium states and progression rules, where richness and endemism rise with the age of the archipelago owing to the splitting of ancestral lineages (cladogenesis). However, marine organisms have received comparatively little scientific attention. Therefore, island and seamount evolutionary processes in the aquatic environment remain unclear. Here we analyse the evolutionary history of reef fishes that are endemic to a volcanic ridge of seamounts and islands to understand their relations to island evolution and sea-level fluctuations. We also test how this evolutionary history fits island biogeography theory. We found that most endemic species have evolved recently (Pleistocene epoch), during a period of recurrent sea-level changes and intermittent connectivity caused by repeated aerial exposure of seamounts, a finding that is consistent with an ephemeral ecological speciation process. Similar to findings for terrestrial biodiversity, our data suggest that the marine speciation rate on islands is negatively correlated with immigration rate. However, because marine species disperse better than terrestrial species, most niches are filled by immigration: speciation increases with the random accumulation of species with low dispersal ability, with few opportunities for in situ cladogenesis and adaptive radiation. Moreover, we confirm that sea-level fluctuations and seamount location play a critical role in marine evolution, mainly by intermittently providing stepping stones for island colonization.
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NaCl islands decorated with 2D or 3D 3,4,9,10-perylene-tetracarboxylic-dianhydride nanostructures
International Nuclear Information System (INIS)
Sun Xiaonan; Silly, Fabien
2010-01-01
The formation of PTCDA (3,4,9,10-perylene-tetracarboxylic-dianhydride) nanostrutures on Au(1 1 1)-(22x√(3)) covered with NaCl islands has been studied using scanning tunneling microscopy (STM). Atomically resolved STM images show that NaCl grows as (1 0 0)-terminated layers on Au(1 1 1)-(22x√(3)). Local atomic hexagonal packing has also been observed in the NaCl(1 0 0) layer. At submonolayer NaCl coverage, PTCDA forms two-dimensional islands on the Au(1 1 1) surface and nucleate preferentially at the NaCl island step edges. When the Au surface is fully covered with NaCl layers, PTCDA molecules form three-dimensional molecular clusters decorating the step edges of NaCl layers.
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NaCl islands decorated with 2D or 3D 3,4,9,10-perylene-tetracarboxylic-dianhydride nanostructures
Energy Technology Data Exchange (ETDEWEB)
Sun Xiaonan [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747 AG Groningen (Netherlands); Silly, Fabien, E-mail: Fabien.silly@cea.fr [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, NL-9747 AG Groningen (Netherlands); CEA, IRAMIS, SPCSI, Nanostructures and Organic Semiconductors Laboratory, F-91191 Gif-sur-Yvette (France); UPMC, IPCM, UMR CNRS 7201, 4 place Jussieu, F-75005 Paris (France)
2010-01-15
The formation of PTCDA (3,4,9,10-perylene-tetracarboxylic-dianhydride) nanostrutures on Au(1 1 1)-(22x{radical}(3)) covered with NaCl islands has been studied using scanning tunneling microscopy (STM). Atomically resolved STM images show that NaCl grows as (1 0 0)-terminated layers on Au(1 1 1)-(22x{radical}(3)). Local atomic hexagonal packing has also been observed in the NaCl(1 0 0) layer. At submonolayer NaCl coverage, PTCDA forms two-dimensional islands on the Au(1 1 1) surface and nucleate preferentially at the NaCl island step edges. When the Au surface is fully covered with NaCl layers, PTCDA molecules form three-dimensional molecular clusters decorating the step edges of NaCl layers.
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Hawai'i Island Health Workforce Assessment 2008.
Withy, Kelley; Andaya, January; Vitousek, Sharon; Sakamoto, David
2009-12-01
Anecdotal reports of a doctor shortage on the Big Island have been circulating for years, but a detailed assessment of the health care workforce had not previously been accomplished. The Hawai'i Island Health Workforce Assessment used licensure data, focus groups, telephone follow up to provider offices, national estimates of average provider supply and analysis of insurance claims data to assess the extent of the existing medical and mental health workforce, approximate how many additional providers might be effectively utilized, develop a population-based estimate of future demand and identify causes and potential solutions for the challenges faced. As of February 2008, the researchers were able to locate 310 practicing physicians, 36 nurse practitioners, 6 physician assistants, 51 psychologists, 57 social workers and 42 other mental health providers. Based on national averages, claims analysis and focus groups, the Island could use approximately 45 additional medical professionals to care for the 85% of the population that is medically insured; a larger number to care for the entire population. Ascertaining a complete roster of mental health professionals was not possible using this methodology. The researchers compared the current supply of physicians with the national average of physicians to population and the number of visits to different specialists for the year 2006 and found specific regional shortages of providers. The focus groups concentrated on solutions to the workforce crisis that include the formation of a well-organized, broad collaboration to coordinate recruitment efforts, expand and strengthen retention and renewal activities, and reinvigorate the health profession pipeline and training opportunities. The researchers recommend collaboration between the community, government, business, health center care providers, hospitals and centers to develop a plan before the tenuous state of healthcare on the Big Island worsens. In addition, continued
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A Model of Solar Flares Based on Arcade Field Reconnection and Merging of Magnetic Islands
International Nuclear Information System (INIS)
Choe, G.S.; Cheng, C.Z.
2001-01-01
Solar flares are intense, abrupt releases of energy in the solar corona. In the impulsive phase of a flare, the intensity of hard X-ray emission reaches a sharp peak indicating the highest reconnection rate. It is often observed that an X-ray emitting plasma ejecta (plasmoid) is launched before the impulsive phase and accelerated throughout the phase. Thus, the plasmoid ejection may not be an effect of fast magnetic reconnection as conventionally assumed, but a cause of fast reconnection. Based on resistive magnetohydrodynamic simulations, a solar flare model is presented, which can explain these observational characteristics of flares. In the model, merging of a newly generated magnetic island and a pre-existing island results in stretching and thinning of a current sheet, in which fast magnetic reconnection is induced. Recurrence of homologous flares naturally arises in this model. Mechanisms of magnetic island formation are also discussed
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Some data on the avifauna of the Island of Roti, Lesser Sunda Islands, Indonesia
Verheijen, J.A.J.
1976-01-01
INTRODUCTION For several years I had been looking for an opportunity to visit the island of Roti (Rotti, Roté, Loté). Junge (1954) mentions that only once an ornithological collection was made in the island, namely by Dr. H. F. C. ten Kate, an ethnologist who visited the island in 1891. Büttikofer
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The Balearic Islands in the Alpine Orogeny
Energy Technology Data Exchange (ETDEWEB)
Bourrouilh, R.
2016-10-01
The place of the Balearic Islands in the Alpine orogeny is examined using detailed sedimentology studies, stratigraphical studies from the Lower Devonian (Lochkovian) to modern times and a careful tectonic review of sedimentary formations from the Western Mediterranean. Despite being considered as the ultimate end of the north-eastern termination of the Betic Cordillera, the history of the Balearic archipelago seems to be closer to the tectonic opening of the Gulf of Valencia and to the Corsica-Sardinia rotation, and thus to the tectonic history of the Western Mediterranean Sea, than to the tectonics of the Betic Cordillera which appear as its symmetrical image with respect to this opening. (Author)
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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.
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Islanded operation of distribution networks
International Nuclear Information System (INIS)
2005-01-01
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
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HYDROGEOLOGICAL RELATIONS ON KARSTIFIED ISLANDS - VIS ISLAND CASE STUDY
Directory of Open Access Journals (Sweden)
Josip Terzić
2004-12-01
Full Text Available An approach to the hydrogeological investigations on Adriatic islands is presented on the Island of Vis case study. Infiltration, accumulation and discharge of the groundwater occur in karstified rock mass. Hydrogeological relations are mostly a consequence of the geological setting, because of the complete hydrogeologic barrier in Komiža bay, and relative barrier in the area of karst poljes. Significant research was performed in the 1999 – 2000 period aimed of better understanding of hydrogeological relations. These investigations, as well as reinterpretation of some previously known data, included structural geology, hydrogeology, hydrology and hydrochemistry. Approximate rock mass hydraulic conductivity calculation is also shown, as well as level of its usability in such terrain. Based on all these methods, it is possible to conclude that on the Island of Vis there is no saline water present underneath the entire island. There is only a saline water wedge which is formed on the top of relatively impermeable base rock, some few tens of meters under recent sea level. With such a model, and taking in account the hydrological balance, it is possible to conclude that there is possibility of higher amount of groundwater exploitation then it is today (the paper is published in Croatian.
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International Nuclear Information System (INIS)
Takizuka, Tomonori
2003-01-01
The formation mechanism of the current hole in tokamak plasmas is reviewed. Experimental results of JT-60U are shown. Increase of the off-central noninductive current is a key factor for the current-hole formation. The internal Transport Barrier (ITB), which generates large bootstrap current, plays an important role. The central current density in the hole stays nearly 0. The idea of a new equilibrium for a tokamak plasma with a current hole is introduced. This equilibrium configuration called Axisymmetric Tri-Magnetic-Islands (ATMI) equilibrium', has three islands along the R direction (a central-negative-current island and side-positive-current islands). The equilibrium is stable with the elongation coils when the current in the ATMI region is limited to a small amount. The confinement properties of a current-hole configuration with box-type ITB is described. A scaling of the core poloidal beta inside the ITB, β p,core , is given as ε f β p,core approx. = 1, which suggests the equilibrium limit (ε f : inverse aspect ratio at the ITB foot). Though the core stored energy is little dependent on the heating power, the estimated heat diffusivity in the ITB region moderately correlates with a neoclassical diffusivity. (author)
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Energy Technology Data Exchange (ETDEWEB)
Polido, Alexandra, E-mail: a.polido@campus.fct.unl.pt [CENSE, Center for Environmental and Sustainability Research, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus da Caparica, 2829-516 Caparica (Portugal); João, Elsa, E-mail: elsa.joao@strath.ac.uk [Department of Civil and Environmental Engineering, University of Strathclyde, Level 5, James Weir Building, 75 Montrose Street, Glasgow G1 1XJ, Scotland (United Kingdom); Ramos, Tomás B., E-mail: tabr@fct.unl.pt [CENSE, Center for Environmental and Sustainability Research, Departamento de Ciências e Engenharia do Ambiente, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus da Caparica, 2829-516 Caparica (Portugal)
2016-02-15
The literature concerning Strategic Environmental Assessment (SEA) often refers to the importance of context-specific approaches. However, there is a lack of systematised and consistent studies that enhance tailor-made SEA practices and procedures. Small islands are bounded units of study which may help explore SEA theory and practice in special territories. Small islands present particular features and unique values, such as, small size and population, geographic isolation, limited resources and vulnerable ecosystems. Hence, the main goal of this research was to profile SEA practices and procedures in European small islands and provide a background for future research aiming to improve context-specific SEA applications. To achieve this goal, an exploratory case study was developed using Azores (Portugal) and Orkney (Scotland) archipelagos. An analysis of the corresponding mainland was also carried out to contextualise both case studies. The data collection was achieved through a qualitative content analysis of 43 Environmental Reports. The research found that there is not an SEA context-specific approach used within these European small islands, including guidelines, assessment topics, assessment techniques, follow-up and stakeholders engagement. The debate concerning specific approaches to small islands must be re-focused on the enhancement of SEA capacity-building amongst different stakeholders (including decision-makers), on the development and implementation of collaborative approaches, and on the exchange of knowledge and experiences between small islands networks. - Highlights: • Reviewed the differences between the Portuguese and Scottish SEA system • Showed a low integration of SEA specific features in reports of European small islands • Provides background for future SEA research for small islands approaches.
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International Nuclear Information System (INIS)
Polido, Alexandra; João, Elsa; Ramos, Tomás B.
2016-01-01
The literature concerning Strategic Environmental Assessment (SEA) often refers to the importance of context-specific approaches. However, there is a lack of systematised and consistent studies that enhance tailor-made SEA practices and procedures. Small islands are bounded units of study which may help explore SEA theory and practice in special territories. Small islands present particular features and unique values, such as, small size and population, geographic isolation, limited resources and vulnerable ecosystems. Hence, the main goal of this research was to profile SEA practices and procedures in European small islands and provide a background for future research aiming to improve context-specific SEA applications. To achieve this goal, an exploratory case study was developed using Azores (Portugal) and Orkney (Scotland) archipelagos. An analysis of the corresponding mainland was also carried out to contextualise both case studies. The data collection was achieved through a qualitative content analysis of 43 Environmental Reports. The research found that there is not an SEA context-specific approach used within these European small islands, including guidelines, assessment topics, assessment techniques, follow-up and stakeholders engagement. The debate concerning specific approaches to small islands must be re-focused on the enhancement of SEA capacity-building amongst different stakeholders (including decision-makers), on the development and implementation of collaborative approaches, and on the exchange of knowledge and experiences between small islands networks. - Highlights: • Reviewed the differences between the Portuguese and Scottish SEA system • Showed a low integration of SEA specific features in reports of European small islands • Provides background for future SEA research for small islands approaches
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Directory of Open Access Journals (Sweden)
Abrahamsen, Niels
2006-07-01
Full Text Available The palaeomagnetic dating and evolution of the Faroe Islands are discussed in the context of new density and rock magnetic results from the deepened Lopra-1/1A well. The reversal chronology of thec. 6½ km thick basalt succession is also described. The polarity record of the Faroe Islands may now be correlated in detail with the Geomagnetic Polarity Time Scale. The lowermost (hidden part of thelower basalt formation correlates with Chron C26r (Selandian age, the top (exposed part of the lower basalt formation correlates with Chrons C26n, C25r and C25n (Selandian and Thanetian ageand the middle and upper basalt formations correlate with Chron C24n.3r (Ypresian. Inclinations indicate a far-sided position of the palaeomagnetic poles, which is characteristic of results from mostPalaeogene volcanics from the northern North Atlantic region. The density, magnetic susceptibility and magnetic remanence of 20 specimens from one solid core (1½ m in length and 26 sidewall cores from the well between –2219 and –3531 m below sea level (b.s.l. suggest that the volcanic materials can be divided into two characteristic groups: solid unaltered basalts and altered basalts and tuffs. The magnetic properties are typically log-normally distributed and the carriers of remanence are Ti-poor Ti-magnetites with Curie temperatures close to 580°C. The inclination of the 1½ m core at 2380 m b.s.l. is dominantly negative (two plugs at the very top of the core do show normal polarity, but they are likely to be misoriented as all specimens appear to be from one flow. Magnetic logging (magnetic susceptibility and field intensity down to 3515 m b.s.l. was made in Lopra-1/1A together with other geophysical logs but did not yield conclusive inclination data.
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Gao, Liang; Zhao, Yue; Yang, Zhenyu; Liu, Jianmin; Liu, Xiaochun; Zhang, Shuan-Hong; Pei, Junling
2018-01-01
To reconstruct the paleoposition of the Antarctic Peninsula relative to the South American Plate during the breakup of Gondwana, as well as the opening kinematics of the Drake Passage, we conducted detailed paleomagnetic, rock magnetic, and isotopic chronology studies of Byers Peninsula (Livingston Island) and Fildes Peninsula (King George Island) of the South Shetland Islands. The 40Ar/39Ar ages of the Agate Beach Formation to the Long Hill Formation in Fildes Peninsula range from 56.38 ± 0.2 Ma to 52.42 ± 0.19 Ma. Low natural remanent magnetization/isothermal remanent magnetization ratios, inconsistency with the polarity constrained by the paleomagnetic results and 40Ar/39Ar age constraints, as well as the widespread cation-deficient titanomagnetite and Ti-free magnetite of secondary origin, indicate that the volcanic and sedimentary rocks of Fildes Peninsula were remagnetized at about 55 Ma. Combining our results with previous data from the South Shetland Islands and the Antarctic Peninsula, we calculated the paleopoles for 110 Ma and 55 Ma for the South Shetland Islands and the Antarctic Peninsula. The paleomagnetic reconstruction of the relative paleoposition of the Antarctic Peninsula and South America shows that these plates were connected and experienced a southward movement and clockwise rotation from 110 to 55 Ma. Subsequently, southward translation and clockwise rotation of the Antarctic Peninsula between 55 and 27 Ma separated the Antarctic Peninsula and South America, forming the Drake Passage. Northward translation of South America after 27 Ma increased the N-S divergence and increased the distance between the Antarctic Peninsula and the South American Plate.
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Van der Linden, Inge; Avalos Llano, Karina R; Eriksson, Markus; De Vos, Winnok H; Van Damme, Els J M; Uyttendaele, Mieke; Devlieghere, Frank
2016-12-05
The influence of a selection of minimal processing techniques (sanitizing wash prior to packaging, modified atmosphere, storage conditions under light or in the dark) was investigated in relation to the survival of, attachment to and internalization of enteric pathogens in fresh produce. Cut Iceberg lettuce was chosen as a model for fresh produce, Escherichia coli O157:H7 (E. coli O157) and Salmonella enterica were chosen as pathogen models. Care was taken to simulate industrial post-harvest processing. A total of 50±0.1g of fresh-cut Iceberg lettuce was packed in bags under near ambient atmospheric air with approximately 21% O 2 (NAA) conditions or equilibrium modified atmosphere with 3% O 2 (EMAP). Two lettuce pieces inoculated with E. coli O157 BRMSID 188 or Salmonella Typhimurium labeled with green fluorescent protein (GFP) were added to each package. The bags with cut lettuce were stored under either dark or light conditions for 2days at 7°C. The pathogens' capacity to attach to the lettuce surface and cut edge was evaluated 2days after inoculation using conventional plating technique and the internalization of the bacteria was investigated and quantified using confocal microscopy. The effect of a sanitizing wash step (40mg/L NaClO or 40mg/L peracetic acid+1143mg/L lactic acid) of the cut lettuce prior to packaging was evaluated as well. Our results indicate that both pathogens behaved similarly under the investigated conditions. Pathogen growth was not observed, nor was there any substantial influence of the investigated atmospheric conditions or light/dark storage conditions on their attachment/internalization. The pathogens attached to and internalized via cut edges and wounds, from which they were able to penetrate into the parenchyma. Internalization through the stomata into the parenchyma was not observed, although some bacteria were found in the substomatal cavity. Washing the cut edges with sanitizing agents to reduce enteric pathogen numbers was not
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Virtually Impossible: Deleuze and Derrida on the Political Problem of Islands (and Island Studies
Directory of Open Access Journals (Sweden)
Stewart Williams
2012-11-01
Full Text Available It is commonplace to think of an island as a discreetly bounded unit. Selected writings on islands by the poststructuralist philosophers Gilles Deleuze and Jacques Derrida reveal the island variously to be both real and imaginary, mythological and scientific, but as most problematic when constituted in political terms as an indivisible, sovereign entity. These two thinkers’ more broadly developed concepts of the virtual and the impossible, respectively, are seen to disrupt any assumptions about the fixity and closure of the island polity. Instead they emphasize its actualization through processual relations that can be difficult yet dynamic and decisive in effecting the move from being to becoming-other. As the possibilities for instituting more ethical as well as different political relations open up, the question of island studies remaining in its currently coherent, familiar form is raised for consideration.
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Bamboo Diversity in Sumba Island
Directory of Open Access Journals (Sweden)
KARSONO
2005-04-01
Full Text Available Bamboo is one of the economic plant which grow widely in the villages and have been used by the local people in the villages. Indonesia has about 10% of the world bamboo, 50% among them was endemic to Indonesia. According Widjaja (2001 Lesser Sunda Island which consists of Lombok, Sumbawa, Flores, Timor, Sumba and other small island eastern of Flores has 14 bamboo species, however, the information from the Sumba Island was lacking because of lacking data from this area except one species which was proposed by S. Soenarko in 1977 where the type specimens was collected by Iboet 443 in 1925. To fullfill data from the Sumba Island, an exploration to this area has been conducted on July 2003. The observation was done in West Sumba and East Sumba District, especially in two natioal parks at both districts. According to this inventory study in the Sumba Island, there were 10 bamboo species in Sumba Island, 1 species among them (Dinochloa sp. was a new species which has not been collected before, whereas the other species (Dinochloa kostermansiana has a new addition record from this area. The bamboo species in Sumba Island were Bambusa blumeana, Bambusa vulgaris, Dendocalamus asper, Dinochloa kostermansiana, Dinochloa sp., Gigantochloa atter, Nastus reholtumianus, Phyllostachys aurea, Schisotachyum brachycladum and Schizostachyum lima. From 10 recorded species, the genera Dinochloa and Nastus grow wild in the forest, whereas another species grow widly or cultivated in the garden. Furthermore, the genus Dinochloa was the only genus grow climbing. The endemic species found in Sumba Island was Nastus reholttumianus, whereas Dinochloa kostermansiana was also found in Flores Island.
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Biological invasions on oceanic islands: Implications for island ecosystems and avifauna
Dean E. Pearson
2009-01-01
Biological invasions present a global threat to biodiversity, but oceanic islands are the systems hardest hit by invasions. Islands are generally depauperate in species richness, trophic complexity, and functional diversity relative to comparable mainland ecosystems. This situation results in low biotic resistance to invasion and many empty niches for invaders to...
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Oak restoration trials: Santa Catalina Island
Lisa Stratton
2002-01-01
Two restoration trials involving four oak species have been implemented as part of a larger restoration program for Catalina Island. In 1997 the Catalina Island Conservancy began an active program of restoration after 50 years of ranching and farming activities on the island. The restoration program includes removing feral goats and pigs island-wide and converting 80...
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Influence of Meteorological Regimes on Cloud Microphysics Over Ross Island, Antarctica
Glennon, C.; Wang, S. H.; Scott, R. C.; Bromwich, D. H.; Lubin, D.
2017-12-01
The Antarctic provides a sharp contrast in cloud microphysics from the high Arctic, due to orographic lifting and resulting strong vertical motions induced by mountain ranges and other varying terrain on several spatial scales. The Atmospheric Radiation Measurement (ARM) West Antarctic Radiation Experiment (AWARE) deployed advanced cloud remote sensing equipment to Ross Island, Antarctica, from December 2015 until January 2016. This equipment included scanning and zenith radars operating in the Ka and X bands, a high spectral resolution lidar (HSRL), and a polarized micropulse lidar (MPL). A major AWARE objective is to provide state-of-the-art data for improving cloud microphysical parameterizations in climate models. To further this objective we have organized and classified the local Ross Island meteorology into distinct regimes using k-means clustering on ERA-Interim reanalysis data. We identify synoptic categories producing unique regimes of cloud cover and cloud microphysical properties over Ross Island. Each day of observations can then be associated with a specific meteorological regime, thus assisting modelers with identifying case studies. High-resolution (1 km) weather forecasts from the Antarctic Mesoscale Prediction System (AMPS) are sorted into these categories. AMPS-simulated anomalies of cloud fraction, near-surface air temperature, and vertical velocity at 500-mb are composited and compared with ground-based radar and lidar-derived cloud properties to identify mesoscale meteorological processes driving Antarctic cloud formation. Synoptic lows over the Ross and Amundsen Seas drive anomalously warm conditions at Ross Island by injecting marine air masses inland over the West Antarctic Ice Sheet (WAIS). This results in ice and mixed-phase orographic cloud systems arriving at Ross Island from the south to southeast along the Transantarctic Mountains. In contrast, blocking over the Amundsen Sea region brings classical liquid-dominated mixed-phase and
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Sargis, Eric J.; Woodman, Neal; Morningstar, Natalie C.; Reese, Aspen T.; Olson, Link E.
2014-01-01
The Mentawai and Batu Island groups off the west coast of Sumatra have a complicated geological and biogeographical history. The Batu Islands have shared a connection with the Sumatran ‘mainland’ during periods of lowered sea level, whereas the Mentawai Islands, despite being a similar distance from Sumatra, have remained isolated from Sumatra, and probably from the Batu Islands as well. These contrasting historical relationships to Sumatra have influenced the compositions of the respective mammalian faunas of these island groups. Treeshrews (Scandentia, Tupaiidae) from these islands have, at various times in their history, been recognized as geographically circumscribed populations of a broadly distributed Tupaia glis, subspecies, or distinct species. We used multivariate analyses of measurements from the skull and hands to compare the island populations from Siberut (Mentawai Islands) and Tanahbala (Batu Islands) with the geographically adjacent species from the southern Mentawai Islands (T. chrysogaster) and Sumatra (T. ferruginea). Results from both the skull and manus of the Siberut population show that it is most similar to T. chrysogaster, whereas the Tanahbala population is more similar to T. ferruginea, confirming predictions based on island history. These results are further corroborated by mammae counts. Based on these lines of evidence, we include the Siberut population in T. chrysogaster and the Tanahbala population in T. ferruginea. Our conclusions expand the known distributions of both the Mentawai and Sumatran species. The larger geographical range of the endangered T. chrysogaster has conservation implications for this Mentawai endemic, so populations and habitat should be re-evaluated on each of the islands it inhabits. However, until such a re-evaluation is conducted, we recommend that the IUCN Red List status of this species be changed from ‘Endangered’ to ‘Data Deficient’.
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Sable Island: A heritage to preserve
Energy Technology Data Exchange (ETDEWEB)
Villeneuve, C.
1997-09-01
Sable Island is strategically located on the edge of the teeming fisheries of the Newfoundland Grand Banks and near one of the main sea routes between North America and Europe. It has been the bane of navigators from 1583 onward, with 250 ships running aground, the latest in 1947. Marine productivity around Sable Island is very high owing to the temperature differences between the currents and the adjacent underwater topography. Dolphins and whales abound in the area known as the `Gully`, and there are no fewer than 36 fish species present in the waters surrounding the Island. Approximately 35 per cent of the Island is covered by vegetation which is limited to species adapted to sandy soil containing little organic matter and few nutrients. Some plants, such as the American beachgrass, grow in dense colonies and help to stabilize the dunes. Bird diversity is limited to species adapted to open areas, ponds and the littoral. Some 324 species have been recorded on the Island, but only 25 are known to nest there. The Island is one of world`s most important breeding sites for grey seals where they can be observed in great numbers during mating, whelping and moulting season. Among the many introduced animals only the legendary horses of Sable Island remain to this day. Despite its remoteness and isolation, the Island faces many threats, one of the most worrysome being the erosion of the eastern extremity of the Island during severe winter storms. The Island benefits from its status as a Migratory Bird Sanctuary, and is legally protected under Sable Island Regulations of the Navigation Act.
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Islanded operation of distributed networks
Energy Technology Data Exchange (ETDEWEB)
NONE
2005-07-01
This report summarises the findings of a study to investigate the regulatory, commercial and technical risks and benefits associated with the operation of distributed generation to power an islanded section of distributed network. A review of published literature was carried out, and UK generators were identified who could operate as part of an island network under the existing technical, regulatory, and safety framework. Agreement on case studies for consideration with distributed network operators (DNOs) is discussed as well as the quantification of the risks, benefits and costs of islanding, and the production of a case implementation plan for each case study. Technical issues associated with operating sections of network in islanded mode are described, and impacts of islanding on trading and settlement, and technical and commercial modelling are explored.
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Islanded operation of distributed networks
International Nuclear Information System (INIS)
2005-01-01
This report summarises the findings of a study to investigate the regulatory, commercial and technical risks and benefits associated with the operation of distributed generation to power an islanded section of distributed network. A review of published literature was carried out, and UK generators were identified who could operate as part of an island network under the existing technical, regulatory, and safety framework. Agreement on case studies for consideration with distributed network operators (DNOs) is discussed as well as the quantification of the risks, benefits and costs of islanding, and the production of a case implementation plan for each case study. Technical issues associated with operating sections of network in islanded mode are described, and impacts of islanding on trading and settlement, and technical and commercial modelling are explored
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Oberle, Ferdinand K. J.; Swarzenski, Peter W.; Storlazzi, Curt
2017-04-01
Atoll islands, most of which only average 1-2 meters above today's sea level, provide a tremendous natural laboratory in which to study and better understand the intensifying impacts of high rates of sea-level rise on tropical reef-lined islands globally due to their unique geologic structure and limited water supply. Groundwater resources of atolls are typically minimal due to the low elevation and small surface area of the islands and are also subject to recurring droughts, and more frequent, storm-driven seawater overwash events. Although groundwater is the principal means of freshwater storage on atoll islands and is a major factor in determining the overall sustainability of island communities, hydrological data on how an aquifer will response to changes in sea-level rise or storm-driven overwash remain limited. We here present high-resolution time series hydrogeological and geochemical data to determine the role of the atoll's carbonate geology, land use, and atmospheric and oceanographic forcing in driving coastal groundwater exchange on the island of Roi Namur on Kwajalein Atoll in the Republic of the Marshall Islands. This information can provide new estimates on the recovery and resilience of coastal groundwater resources on such islands to expected climate change-driven perturbations.
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The coastline remote sensing survey for Zhao Shu Island in Xisha Islands based on WorldView-2
Li, Li; Zhong, Chang; Kong, Fanping
2014-11-01
Due to diastrophism, tide action and human activities, the coastline is always in flux. There are lots of coral islands in the south sea of China. Remote sensing survey for the coastline not only can reassert the necessity and importance of coral protection, but also can provide basic data and scientific basis for island ecologic protection, reasonable utilization of land resources. The study area named Zhao Shu Island lies in Jintong Islands of Xisha. It is a coral island which has people inhabited. Using WorldView-2 satellite remote sensing images as data sources we carry out three phases of coastline investigation and monitoring. The satellite data phases are 2002, 2010 and 2013. Firstly, affirm the bands valuable for color composition on the basis of spectral and correlation analysis. Then extract the coastline by a series of image process, such as image correction, fusion, waterline extraction and coastline revision. Finally determine the coastline types and length by artificial interpretation. The results show that the island length is gradually smaller, which means the island area is reducing. The beach bedrock coast in northern island was eroded seriously especially during the period between 2010 and 2013. In addition, the shoal head shape in the western island changed a lot.
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Autumn monitoring of resident avifauna on Guana Island, British Virgin Islands
C.W. Boal; J.M. Wunderle Jr.; W.J. Arendt
2013-01-01
Although the Caribbean region is considered a biodiversity hotspot and a priority for ecological conservation efforts, little information exists on population trends of West Indian landbirds. We combined avian survey data collected from three studies spanning a 16-year period on a small island with a minimal human presence in the British Virgin Islands. Although...
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The pacific island health care project.
Person, Donald Ames
2014-01-01
US Associated/Affiliated Pacific Islands (USAPI) include three freely associated states: Marshall Islands, Federated States of Micronesia, Palau, and three Territories: American Samoa, Guam, and Commonwealth of the Northern Mariana Islands. The Pacific Island Health Care Project (PIHCP) provides humanitarian medical referral/consultation/care to >500,000 indigenous people of these remote islands. In the mid-1990s, we developed a simple store-and-forward program to link the USAPI with Tripler Army Medical Center. This application allowed image attachment to email consultations. More than 8000 Pacific Islanders have benefited from the program. Three thousand Pacific Islanders prior to telemedicine (1990-1997) and since store-and-forward telemedicine (1997-present), the PIHCP has helped an additional 5000. Records post dynamically and are stored in an archival database. The PIHCP is the longest running telemedicine program in the world delivering humanitarian medical care. It has bridged the Developing World of the remote Pacific Islands with advanced medical and surgical care available at a major US military teaching hospital. (The opinions expressed here are those of the author and not that of the Army, Department of Defense, or the US Government.).
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The Pacific Island Health Care Project
Directory of Open Access Journals (Sweden)
Donald Ames Person
2014-10-01
Full Text Available Introduction/BackgroundUS Associated/Affiliated Pacific Islands (USAPI include 3 Freely Associated States: Marshall Islands, Federated States of Micronesia, Palau and 3 Territories: American Samoa, Guam, and Commonwealth of the Northern Mariana Islands. ObjectiveThe Pacific Island Health Care Project (PIHCP provides humanitarian medical referral/consultation/care to >500,000 indigenous people of these remote islands. Methods In the mid-1990s, we developed a simple store-and-forward program to link the USAPI with Tripler Army Medical Center (TAMC. This application allowed image attachment to email consultations. ResultsMore than 8000 Pacific Islanders have benefited from the program. 3000 Pacific Islanders prior to telemedicine (1990-1997 and since store-and-forward telemedicine (1997-present, the PIHCP has helped an additional 5000. Records post dynamically and are stored in an archival database. Conclusion The PIHCP is the longest running telemedicine program in the world delivering humanitarian medical care. It has bridged the Developing World of the remote Pacific islands with advanced medical and surgical care available at a major US military teaching hospital.(The opinions expressed here are those of the author and not that of the Army, Department of Defense, or the US Government.
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Ti and N adatom descent pathways to the terrace from atop two-dimensional TiN/TiN(001) islands
Energy Technology Data Exchange (ETDEWEB)
Edström, D., E-mail: daned@ifm.liu.se [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping (Sweden); Sangiovanni, D.G.; Hultman, L.; Chirita, V. [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping (Sweden); Petrov, I.; Greene, J.E. [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping (Sweden); Frederick Seitz Materials Research Laboratory and the Materials Science Department, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)
2014-05-02
We use classical molecular dynamics and the modified embedded atom method to determine residence times and descent pathways of Ti and N adatoms on square, single-atom-high, TiN islands on TiN(001). Simulations are carried out at 1000 K, which is within the optimal range for TiN(001) epitaxial growth. Results show that the frequency of descent events, and overall adatom residence times, depend strongly on both the TiN(001) diffusion barrier for each species as well as the adatom island-edge location immediately prior to descent. Ti adatoms, with a low diffusion barrier, rapidly move toward the island periphery, via funneling, where they diffuse along upper island edges. The primary descent mechanism for Ti adatoms is via push-out/exchange with Ti island-edge atoms, a process in which the adatom replaces an island edge atom by moving down while pushing the edge atom out onto the terrace to occupy an epitaxial position along the island edge. Double push-out events are also observed for Ti adatoms descending at N corner positions. N adatoms, with a considerably higher diffusion barrier on TiN(001), require much longer times to reach island edges and, consequently, have significantly longer residence times. N adatoms are found to descend onto the terrace by direct hopping over island edges and corner atoms, as well as by concerted push-out/exchange with N atoms adjacent to Ti corners. For both adspecies, we also observe several complex adatom/island interactions, before and after descent onto the terrace, including two instances of Ti island-atom ascent onto the island surface. - Highlights: • We use classical molecular dynamics to model Ti and N adatom migration on TiN(001) islands. • N adatoms remain on islands significantly longer than Ti adatoms. • Ti adatoms descend via push-out/exchange, N adatoms primarily by direct hops. • N adatoms act as precursors for multilayer formation and surface roughening.
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Ti and N adatom descent pathways to the terrace from atop two-dimensional TiN/TiN(001) islands
International Nuclear Information System (INIS)
Edström, D.; Sangiovanni, D.G.; Hultman, L.; Chirita, V.; Petrov, I.; Greene, J.E.
2014-01-01
We use classical molecular dynamics and the modified embedded atom method to determine residence times and descent pathways of Ti and N adatoms on square, single-atom-high, TiN islands on TiN(001). Simulations are carried out at 1000 K, which is within the optimal range for TiN(001) epitaxial growth. Results show that the frequency of descent events, and overall adatom residence times, depend strongly on both the TiN(001) diffusion barrier for each species as well as the adatom island-edge location immediately prior to descent. Ti adatoms, with a low diffusion barrier, rapidly move toward the island periphery, via funneling, where they diffuse along upper island edges. The primary descent mechanism for Ti adatoms is via push-out/exchange with Ti island-edge atoms, a process in which the adatom replaces an island edge atom by moving down while pushing the edge atom out onto the terrace to occupy an epitaxial position along the island edge. Double push-out events are also observed for Ti adatoms descending at N corner positions. N adatoms, with a considerably higher diffusion barrier on TiN(001), require much longer times to reach island edges and, consequently, have significantly longer residence times. N adatoms are found to descend onto the terrace by direct hopping over island edges and corner atoms, as well as by concerted push-out/exchange with N atoms adjacent to Ti corners. For both adspecies, we also observe several complex adatom/island interactions, before and after descent onto the terrace, including two instances of Ti island-atom ascent onto the island surface. - Highlights: • We use classical molecular dynamics to model Ti and N adatom migration on TiN(001) islands. • N adatoms remain on islands significantly longer than Ti adatoms. • Ti adatoms descend via push-out/exchange, N adatoms primarily by direct hops. • N adatoms act as precursors for multilayer formation and surface roughening
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An Island Coalescence Scenario for Near-Earth Current Disruption in the Magnetotail
International Nuclear Information System (INIS)
Zhi-Wei, Ma; Xing-Qiang, Lu
2009-01-01
A current disruption and dipolarization scenario associated with island coalescences in the near-Earth region is proposed. The thin and elongated current-sheet built up during the growth phase is unstable due to a tearing mode instability that leads to formation of multiple magnetic islands (or magnetic flux ropes in the three dimensional case) in the near-Earth region. The growth rate of the tearing mode should be different in different locations because the rate is in general determined by the external driving force and the local plasma sheet properties. When the rate of the magnetic reconnection in the mid-tail region around 20R E is much larger than that in other locations, the strong bulk earthward flows resulting from the fast reconnection in the mid-tail drive the earthward convection and the coalescence of the magnetic islands. Consequently, the cross-tail current in the near-Earth region is suddenly disrupted and the geometry of the magnetic field changes from tail-like to dipolar-like in the ideal time scale. This proposed scenario is tested by Hall MHD simulation and is compared with the observations. (geophysics, astronomy, and astrophysics)
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Directory of Open Access Journals (Sweden)
Lucas J. Siegfried
2014-12-01
Full Text Available doi: http://dx.doi.org/10.15447/sfews.2014v12iss4art2Water use estimation is central to managing most water problems. To better understand water use in California’s Sacramento–San Joaquin Delta, a collaborative, integrated approach was used to predict Delta island diversion, consumption, and return of water on a more detailed temporal and spatial resolution. Fabian Tract and Staten Island were selected for this pilot study based on available data and island accessibility. Historical diversion and return location data, water rights claims, LiDAR digital elevation model data, and Google Earth were used to predict island diversion and return locations, which were tested and improved through ground-truthing. Soil and land-use characteristics as well as weather data were incorporated with the Integrated Water Flow Model Demand Calculator to estimate water use and runoff returns from input agricultural lands. For modeling, the islands were divided into grid cells forming subregions, representing fields, levees, ditches, and roads. The subregions were joined hydrographically to form diversion and return watersheds related to return and diversion locations. Diversions and returns were limited by physical capacities. Differences between initial model and measured results point to the importance of seepage into deeply subsided islands. The capabilities of the models presented far exceeded current knowledge of agricultural practices within the Delta, demonstrating the need for more data collection to enable improvements upon current Delta Island Consumptive Use estimates.
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Akman, Nurten; Özdoğan, Cem
2018-04-01
We systematically investigate the energetics of ion implantation, stability, electronic, and magnetic properties of graphene/hexagonal boron nitrate (h-BN) in-plane hybrids through first principle calculations. We consider hexagonal and triangular islands in supercells of graphene and h-BN layouts. In the case of triangular islands, both phases mix with each other by either solely Csbnd N or Csbnd B bonds. We also patterned triangles with predominating Csbnd N or Csbnd B bonds at their interfaces. The energetics of island implantation is discussed in detail. Formation energies point out that the island implantation could be even exothermic for all hybrids studied in this work. Effects of size and shape of the island, and dominating bonding sort at the island-layout interfaces on the stability, band gap, and magnetic properties of hybrids are studied particularly. The hybrids become more stable with increasing island size. Regardless of the layout, hybrids with hexagonal islands are all non-magnetic and semiconducting. One can thus open a band gap in the semimetallic graphene by mixing it with the h-BN phase. In general, hybrids containing graphene triangles show metallic property and exhibit considerable amount of magnetic moments for possible localized spin utilizations. Total magnetic moment of hybrids with both graphene and h-BN layouts increases with growing triangle island as well. The spin densities of magnetic hybrids are derived from interfaces of the islands and diminish towards their center. We suggest that the increase in stability and magnetic moment depend on the number of atoms at the interfaces rather than the island size.
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Engelbrecht, Andrea; Mörs, Thomas; Reguero, Marcelo A.; Kriwet, Jürgen
2018-01-01
Seymour Island, Antarctic Peninsula, is known for its wealth of fossil remains. This island provides one of the richest fossiliferous Paleogene sequences in the world. Chondrichthyans seemingly dominate this Eocene marine fauna and offer a rare insight into high-latitude faunas during the Palaeogene. So far, only a few isolated teeth of carcharhinid sharks have been reported from Seymour Island. Bulk sampling in the well-exposed La Meseta and Submeseta formations yielded new and abundant chondrichthyan material, including numerous teeth of carcharhinid and triakid sharks. Here, we present a reevaluation of the previously described carcharhinid remains and a description of new taxa: Meridiogaleus cristatus, gen. et sp. nov., Kallodentis rythistemma, gen. et sp. nov., Abdounia richteri, sp. nov., and Abdounia mesetae, sp. nov. The carcharhiniforms Mustelus sp. and Galeorhinus sp. are reported based on rare material, whereas teeth previously assigned to Scoliodon represent a nomen dubium. PMID:29551850
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Synthesis of hard magnetic Mn3Ga micro-islands by e-beam evaporation
Akdogan, O.
2018-05-01
The permanent magnet industry heavily depends on Nd-Fe-B and Sm-Co alloys because of their high-energy product and high room temperature coercivity. Main ingredient for having such superior magnetic properties compared to other known ferromagnetic materials is rare earth elements (Nd, Sm, Dy…). However recent worldwide reserve and export limitation problem of rare earths, shifted researchers' focus to rare earth free permanent magnets. Among many alternatives (FePt, Zr2Co11, FeNi …), Mn-based alloys are the most suitable due to abundance of the forming elements and trivial formation of the necessary hard phases. In this study, Mn3Ga micro islands have been prepared. Mn3Ga owes its hard magnetic properties to tetragonal D022 phase with magnetic anisotropy energy of 2 MJ/m3. Thin films and islands of Cr/MnGa/Cr layers have been deposited on Si/SiO2 wafers using combination of e-beam and thermal evaporation techniques. Cr has been used as buffer and cover layer to protect the sample from the substrate and prevent oxidation during annealing. Annealing under Ar/H2 forming gas has been performed at 350oC for 10 min. Nano thick islands of 25, 50 and 100 μm lateral size have been produced by photolithography technique. Room temperature coercivity of 7.5 kOe has been achieved on 100 μm micro islands of Mn3Ga. Produced micro islands could be a rare earth free alternative for magnetic memory and MEMS applications.
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Synthesis of hard magnetic Mn3Ga micro-islands by e-beam evaporation
Directory of Open Access Journals (Sweden)
O. Akdogan
2018-05-01
Full Text Available The permanent magnet industry heavily depends on Nd-Fe-B and Sm-Co alloys because of their high-energy product and high room temperature coercivity. Main ingredient for having such superior magnetic properties compared to other known ferromagnetic materials is rare earth elements (Nd, Sm, Dy…. However recent worldwide reserve and export limitation problem of rare earths, shifted researchers’ focus to rare earth free permanent magnets. Among many alternatives (FePt, Zr2Co11, FeNi …, Mn-based alloys are the most suitable due to abundance of the forming elements and trivial formation of the necessary hard phases. In this study, Mn3Ga micro islands have been prepared. Mn3Ga owes its hard magnetic properties to tetragonal D022 phase with magnetic anisotropy energy of 2 MJ/m3. Thin films and islands of Cr/MnGa/Cr layers have been deposited on Si/SiO2 wafers using combination of e-beam and thermal evaporation techniques. Cr has been used as buffer and cover layer to protect the sample from the substrate and prevent oxidation during annealing. Annealing under Ar/H2 forming gas has been performed at 350oC for 10 min. Nano thick islands of 25, 50 and 100 μm lateral size have been produced by photolithography technique. Room temperature coercivity of 7.5 kOe has been achieved on 100 μm micro islands of Mn3Ga. Produced micro islands could be a rare earth free alternative for magnetic memory and MEMS applications.
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Dunn, Michael J; Jackson, Jennifer A; Adlard, Stacey; Lynnes, Amanda S; Briggs, Dirk R; Fox, Derren; Waluda, Claire M
2016-01-01
We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum), chinstrap penguins declined by 68% (-3.6% per annum) and Adélie penguins declined by 42% (-1.5% per annum). The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a gradual
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DEFF Research Database (Denmark)
Patino, Jairo; Whittaker, Robert J.; Borges, Paulo A.V.
2017-01-01
Aims: The 50th anniversary of the publication of the seminal book, The Theory of Island Biogeography, by Robert H. MacArthur and Edward O. Wilson, is a timely moment to review and identify key research foci that could advance island biology. Here, we take a collaborative horizon-scanning approach...... to identify 50 fundamental questions for the continued development of the field. Location: Worldwide. Methods: We adapted a well-established methodology of horizon scanning to identify priority research questions in island biology, and initiated it during the Island Biology 2016 conference held in the Azores......); global change (5); conservation and management policies (5); and invasive alien species (4). Main conclusions: Collectively, this cross-disciplinary set of topics covering the 50 fundamental questions has the potential to stimulate and guide future research in island biology. By covering fields ranging...
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Directory of Open Access Journals (Sweden)
Kuntner Matjaž
2011-05-01
subsequent to colonization, a scenario that might be referred to as speciation in progress. However, due to relatively small sample sizes, we cannot rule out that we simply failed to collect Mascarene haplotypes on Madagascar, a scenario that might imply human mediated dispersal. Nonetheless, the former interpretation better fits the available data and results in a pattern similar to the related Nephilengys. Nephilengys, however, shows higher genetic divergences with diversification on more remote islands. That the better disperser of the two lineages, Nephila, has colonized more islands but failed to diversify, demonstrates how dispersal ability can shape both the patterns of colonization and formation of species across archipelagos.
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Pediatrics in the Marshall Islands
International Nuclear Information System (INIS)
Dungy, C.I.; Morgan, B.C.; Adams, W.H.
1984-01-01
The delivery of health care to children living on isolated island communities presents unique challenges to health professionals. An evolved method of providing longitudinal services to infants and children residing on islands of the Marshall Island chain - a central Pacific portion of the Micronesian archipelago - is presented. The difficulties associated with provision of comprehensive health care in a vast ocean area are discussed
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Directory of Open Access Journals (Sweden)
Mario Fernández-Mazuecos
Full Text Available BACKGROUND: Population genetic theory holds that oceanic island populations are expected to have lower levels of genetic variation than their mainland counterparts, due to founder effect after island colonization from the continent. Cistus monspeliensis (Cistaceae is distributed in both the Canary Islands and the Mediterranean region. Numerous phylogenetic results obtained in the last years allow performing further phylogeographic analyses in Cistus. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed sequences from multiple plastid DNA regions in 47 populations of Cistus monspeliensis from the Canary Islands (21 populations and the Mediterranean basin (26 populations. The time-calibrated phylogeny and phylogeographic analyses yielded the following results: (1 a single, ancestral haplotype is distributed across the Mediterranean, whereas 10 haplotypes in the Canary Islands; (2 four haplotype lineages are present in the Canarian Islands; (3 multiple colonization events across the archipelago are inferred; (4 the earliest split of intraspecific lineages occurred in the Early to Middle Pleistocene (<930,000 years BP. CONCLUSIONS/SIGNIFICANCE: The contrasting pattern of cpDNA variation is best explained by genetic bottlenecks in the Mediterranean during Quaternary glaciations, while the Canarian archipelago acted as a refugium of high levels of genetic diversity. Active colonization across the Canarian islands is supported not only by the distribution of C. monspeliensis in five of the seven islands, but also by our phylogeographic reconstruction in which unrelated haplotypes are present on the same island. Widespread distribution of thermophilous habitats on every island, as those found throughout the Mediterranean, has likely been responsible for the successful colonization of C. monspeliensis, despite the absence of a long-distance dispersal mechanism. This is the first example of a plant species with higher genetic variation among oceanic island
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Dugger, Catherine; Ballard, Grant; Ainley, David G.; Lyber, Phil O'B.; Schine, Casey
2014-01-01
We investigated life history responses to extreme variation in physical environmental conditions during a long-term demographic study of Adélie penguins at 3 colonies representing 9% of the world population and the full range of breeding colony sizes. Five years into the 14-year study (1997–2010) two very large icebergs (spanning 1.5 latitude degrees in length) grounded in waters adjacent to breeding colonies, dramatically altering environmental conditions during 2001–2005. This natural experiment allowed us to evaluate the relative impacts of expected long-term, but also extreme, short-term climate perturbations on important natural history parameters that can regulate populations. The icebergs presented physical barriers, not just to the penguins but to polynya formation, which profoundly increased foraging effort and movement rates, while reducing breeding propensity and productivity, especially at the smallest colony. We evaluated the effect of a variety of environmental parameters during breeding, molt, migration and wintering periods during years with and without icebergs on penguin breeding productivity, chick mass, and nesting chronology. The icebergs had far more influence on the natural history parameters of penguins than any of the other environmental variables measured, resulting in population level changes to metrics of reproductive performance, including delays in nesting chronology, depressed breeding productivity, and lower chick mass. These effects were strongest at the smallest, southern-most colony, which was most affected by alteration of the Ross Sea Polynya during years the iceberg was present. Additionally, chick mass was negatively correlated with colony size, supporting previous findings indicating density-dependent energetic constraints at the largest colony. Understanding the negative effects of the icebergs on the short-term natural history of Adélie penguins, as well as their response to long-term environmental variation, are
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Issues and Tensions in Island Heritage Management: A Case Study of Motuihe Island, New Zealand
Directory of Open Access Journals (Sweden)
David Bade
2010-05-01
Full Text Available This paper draws on a New Zealand case study, Motuihe Island, to examine the challenges of conserving cultural heritage in places renowned for natural heritage values. In keeping with the broader trend toward the ecological restoration of islands close to Auckland, Motuihe Island is undergoing conversion into an ecosystem of native flora and fauna. Issues and tensions relating to the management of natural and cultural heritage will be discussed and influencing aspects investigated: the nature/culture dualism, the effect of New Zealand’s history and identity, and the influence of islandness on heritage management.
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Fellers, Gary M.; Drost, Charles A.; Murphey, Thomas G.
2008-01-01
More than 900 individually marked island night lizards (Xantusia riversiana) were captured on San Nicolas Island, California, between 1984 and 2007 as part of an ongoing study to monitor the status of this threatened species. Our data suggest that at least a few lizards are probably more than 20 years old, and one lizard would be 31.5 years old if it grew at an average rate for the population. Ages of 20 and 30 years seem reasonable given the remarkably slow growth during capture intervals of more than a decade for five of the lizards which we estimated to be 20 or more years old. Like other lizards, island night lizard growth rates vary by size, with larger lizards growing more slowly. In general, growth rates were somewhat greater on San Nicolas Island (compared with Santa Barbara Island), and this increase was sustained through all of the intermediate size classes. The higher growth rate may account for the somewhat larger lizards present on San Nicolas Island, although we cannot discount the possibility that night lizards on San Nicolas are merely living longer. The high percentage of small lizards in the Eucalyptus habitat might seem to reflect a healthy population in that habitat, but the high proportion of small lizards appears to be caused by good reproduction in the 1900s and substantially poorer reproduction in subsequent years. The Eucalyptus habitat has dried quite a bit in recent years. Night lizards in the Haplopappus/Grassland habitat have shown an increase in the proportion of larger lizards since 2000. There has also been an increase in the proportion of large lizards in the Rock Cobble habitat at Redeye Beach. However, there are has been some change in habitat with more elephant seals occupying the same area just above the high tide as do the night lizards. Southern alligator lizards and side-blotched lizards are both non-native on San Nicolas Island. Neither lizard causes obvious harm to island night lizards, and management time and effort should
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Holocene river history of the Danube: human-environment interactions on its islands in Hungary
Viczián, István; Balogh, János; Kis, Éva; Szeberényi, József
2016-04-01
A change in the frequency and magnitude of floods is the main response of river systems to climatic change. Natural floods are highly sensitive to even modest changes of climate. The discharge and the characteristics of floods basically determine the floodplain evolution and the feasibility of human land use and inhabitation on the islands and floodplains. The study revealed that those small islands of large rivers which have the surface rising only some meters above the river are particularly suitable research objects of Holocene climate variability as they are exposed to floods, react sensitively to environmental changes and their evolution may be paralleled with human history. The research area covers the islands of the Danube along the river between Komárom and Paks in Hungary, which is about 250 km, includes more than 50 smaller or formerly existing islands and two extensive islands: the Szentendre Island and Csepel Island. Data gathered from 570 archaeological sites of those islands from Neolithic to Modern Ages were analysed and interpreted in accordance with climate history and floodplain evolution. Nevertheless, the study is not only about river and its environmental history but it demonstrates the role of river and climatic variability in the history of mankind. The environment of the floodplain, the river hydrology, the sedimentation, the formation of islands and the incision and aggradation of surrounding riverbeds, the frequency of devastating floods have significantly changed through the historical time periods, which is reflected in the number and locations of archaeological sites on the islands. Their occupation history reflects the changes in discharge, climate, geomorphology, floods and human impacts and indicates historical periods with low or high probability of inundation. The most favourable periods for an island's occupation concerning the flood risk of its surfaces - and consequently of the banks along the river - are the first parts of a
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Uranium mineralization in the Molteno and Elliot Formations
International Nuclear Information System (INIS)
Le Roux, J.P.
1990-01-01
To date very little has been published on the uranium deposits of the Molteno and Elliot Formations. Two selected deposits from these formations are described and compared to the uranium occurrences of the Beaufort Group. Whereas the latter are generally confined to channel zones due to the fine grain size and impermeable nature of the host sandstones, uranium in the Molteno and Elliot Formations seems to be concentrated in the less permeable 'island' areas. An apparent association with dolerite sills and dykes also suggests that the host sandstones were still sufficiently permeable after intrusion of the dolorite so that ground waters could remobilize the uranium. This agrees with recently published isotopic ages for the mineralization. There is a distinct possibility that roll-type uranium deposits may be present in the Molteno and Elliot Formations, and any future exploration should bear this in mind. 9 figs., 1 tab., 16 refs
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Apparent Brecciation Gradient, Mount Desert Island, Maine
Hawkins, A. T.; Johnson, S. E.
2004-05-01
Mount Desert Island, Maine, comprises a shallow level, Siluro-Devonian igneous complex surrounded by a distinctive breccia zone ("shatter zone" of Gilman and Chapman, 1988). The zone is very well exposed on the southern and eastern shores of the island and provides a unique opportunity to examine subvolcanic processes. The breccia of the Shatter Zone shows wide variation in percent matrix and clast, and may represent a spatial and temporal gradient in breccia formation due to a single eruptive or other catastrophic volcanic event. The shatter zone was divided into five developmental stages based on the extent of brecciation: Bar Harbor Formation, Sols Cliffs breccia, Seeley Road breccia, Dubois breccia, and Great Head breccia. A digital camera was employed to capture scale images of representative outcrops using a 0.5 m square Plexiglas frame. Individual images were joined in Adobe Photoshop to create a composite image of each outcrop. The composite photo was then exported to Adobe Illustrator, which was used to outline the clasts and produce a digital map of the outcrop for analysis. The fractal dimension (Fd) of each clast was calculated using NIH Image and a Euclidean distance mapping method described by Bérubé and Jébrak (1999) to quantify the morphology of the fragments, or the complexity of the outline. The more complex the fragment outline, the higher the fractal dimension, indicating that the fragment is less "mature" or has had less exposure to erosional processes, such as the injection of an igneous matrix. Sols Cliffs breccia has an average Fd of 1.125, whereas Great Head breccia has an average Fd of 1.040, with the stages between having intermediate values. The more complex clasts of the Sols Cliffs breccia with a small amount (26.38%) of matrix material suggests that it is the first stage in a sequence of brecciation ending at the more mature, matrix-supported (71.37%) breccia of Great Head. The results of this study will be used to guide isotopic
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Directory of Open Access Journals (Sweden)
Fery Kurniawan
2016-04-01
Full Text Available The Indonesian government is currently directing its focus of development on the optimum uses of marine and coastal ecosystem services including the marine and coastal tourism. One of the main locus of coastal and marine tourism is the small islands tourism such as Gili Matra Islands among others. Small islands tourism is one of the favourite touristic activities because the destination provides beauty, exotism, aesthetic and a diversity of natural habitats including the warm, clear and attractive water. Tourism is being considered as a development instrument in order to boost a country’s economy and has become part of the global industry. However, tourism is also one of the actors that is responsible for environmental depletion, due to the constructions of buildings and tourism activities. This paper aims to study the level of vulnerability in small islands to tourism as a basis of integrated small islands management in Indonesian conservation area. The group of islands in this study consists of three islands namely Gili Ayer Island, Gili Meno Island and Gili Trawangan Island (known as Gili Matra Islands that were observed using Small Islands Vulnerability Index (SIVI. The results indicate that Gili Matra Islands have a vulnerability status from low into moderate, ranging from 2.25 to 2.75. Gili Ayer Island has the highest vulnerability with SIVI of 2.75 (Moderate, followed by Gili Meno Island with SIVI of 2.50 (Low and Gili Trawangan Island with SIVI of 2.25 (Low. The driving factor of vulnerability is the intensive utilization of marine tourism activities. Tourism is the sole stress to Gili Matra Island’s ecosystem due to its direct damaging impact and reducing its environmental quality. The vulnerability index which was built from the coastline, coral reef, live coral reef, and development area was applicable to assess the small island’s vulnerability in Indonesia, especially for coral island.
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Late Miocene mollusks from the Queen Charlotte Islands, British Columbia, Canada
Addicott, Warren O.
1978-01-01
A fauna of bivalve mollusks, scattered gastropods, and an echinoid from exposures of the Skonun Formation in the northeastern part of Graham Island is indicative of an early late Miocene age and correlation with the provincial Wishkahan Stage. The molluscan assemblages are from the upper 600 of the 1800-m-thick marine and nonmarine formation, which appears to be entirely of late Miocene age. The Skonun Formation is the strandline fa.cies of marginal marine and nonmarine deposits of the northwestern part of the Queen Charlotte basin, a Nieogene embayment paralleling the modern mainland coast. The molluscan fauna and associated lignite beds are known from a few widely scattered outcrops; they are indicative of alternating marine and nonmarine to brackish-water environments in the upper part of the formation. The Skonun fauna occurs near the northern boundary of the Pacific Northwest Neogene molluscan province. It is the only marine Neogene molluscan fauna known from the British Columbia coast. The fauna has strong taxonomic ties with the fauna of the Empire Formation of southwestern Oregon and has several species in common with the upper Miocene of the Lituya district, southeastern Alaska, implying that these three faunas are coeval.
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The Limacidae of the Canary Islands
Regteren Altena, van C.O.
1950-01-01
CONTENTS Introduction............... 3 Systematic survey of the Limacidae of the central and western Canary Islands 5 Biogeographical notes on the Limacidae of the Canary Islands . . . . 21 Alphabetical list of the persons who collected or observed Limacidae in the Canary Islands.............. 31
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2013-04-25
... improve the economic and community development of AAPI businesses; and (iv) strategies to increase public... Islanders; and determine key strategies to help meet the Commission's charge as outlined in E.O. 13515..., assistive listening devices, or material in alternative format) should notify Shelly Coles at (202) 453-7277...
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CRED Gridded Bathymetry of Necker Island (100-021) in the Northwestern Hawaiian Islands
National Oceanic and Atmospheric Administration, Department of Commerce — File 100-021b is a 60-m ASCII grid of depth data collected near Necker Island in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced as...
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Directory of Open Access Journals (Sweden)
Nada Vučetić
2006-12-01
Full Text Available The procedure to determine the coastline length and the area of the island of Rab from the maps at the scales 1:25 000, 1:50 000, 1:100 000, 1:200 000, 1:300 000, 1:500 000, 1:1 000 000 and 1:2 000 000 is described. The map sheets at the scales 1:25 000, 1:100 000 and 1:200 000 were obtained already in a georeferenced raster format, and the others were scanned and georeferenced. This was followed by a manual vectorization of the coastline and a transformation of all coordinates into the 5th zone of the Gauss-Krüger projection. The length of the coastline and the area of the island were calculated in the Gauss-Krüger projection taking into account the deformations of the projection. The results are given in tables and represented graphically.
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The geology of the Falkland Islands
Aldiss, D.T.; Edwards, E.J.
1999-01-01
This report is complementary to the 1:250 000 scale geological map of the Falkland Islands compiled in 1998. The report and map are products of the Falkland Islands Geological Mapping Project (1996-1998). Geological observation and research in the Islands date from 1764. The Islands were visited during two pioneering scientific cruises in the 19th century. Subsequently, many scientists visited en route to the Antarctic or Patagonia. Geological affinities to other parts of the sout...
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The Solomon Islands tsunami of 6 February 2013 field survey in the Santa Cruz Islands
Fritz, H. M.; Papantoniou, A.; Biukoto, L.; Albert, G.
2013-12-01
On February 6, 2013 at 01:12:27 UTC (local time: UTC+11), a magnitude Mw 8.0 earthquake occurred 70 km to the west of Ndendo Island (Santa Cruz Island) in the Solomon Islands. The under-thrusting earthquake near a 90° bend, where the Australian plate subducts beneath the Pacific plate generated a locally focused tsunami in the Coral Sea and the South Pacific Ocean. The tsunami claimed the lives of 10 people and injured 15, destroyed 588 houses and partially damaged 478 houses, affecting 4,509 people in 1,066 households corresponding to an estimated 37% of the population of Santa Cruz Island. A multi-disciplinary international tsunami survey team (ITST) was deployed within days of the event to document flow depths, runup heights, inundation distances, sediment and coral boulder depositions, land level changes, damage patterns at various scales, performance of the man-made infrastructure and impact on the natural environment. The 19 to 23 February 2013 ITST covered 30 locations on 4 Islands: Ndendo (Santa Cruz), Tomotu Noi (Lord Howe), Nea Tomotu (Trevanion, Malo) and Tinakula. The reconnaissance completely circling Ndendo and Tinakula logged 240 km by small boat and additionally covered 20 km of Ndendo's hard hit western coastline by vehicle. The collected survey data includes more than 80 tsunami runup and flow depth measurements. The tsunami impact peaked at Manoputi on Ndendo's densely populated west coast with maximum tsunami height exceeding 11 m and local flow depths above ground exceeding 7 m. A fast tide-like positive amplitude of 1 m was recorded at Lata wharf inside Graciosa Bay on Ndendo Island and misleadingly reported in the media as representative tsunami height. The stark contrast between the field observations on exposed coastlines and the Lata tide gauge recording highlights the importance of rapid tsunami reconnaissance surveys. Inundation distance and damage more than 500 m inland were recorded at Lata airport on Ndendo Island. Landslides were
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Urban Heat Islands and Their Mitigation vs. Local Impacts of Climate Change
Taha, H.
2007-12-01
Urban heat islands and their mitigation take on added significance, both negative and positive, when viewed from a climate-change perspective. In negative terms, urban heat islands can act as local exacerbating factors, or magnifying lenses, to the effects of regional and large-scale climate perturbations and change. They can locally impact meteorology, energy/electricity generation and use, thermal environment (comfort and heat waves), emissions of air pollutants, photochemistry, and air quality. In positive terms, on the other hand, mitigation of urban heat islands (via urban surface modifications and control of man-made heat, for example) can potentially have a beneficial effect of mitigating the local negative impacts of climate change. In addition, mitigation of urban heat islands can, in itself, contribute to preventing regional and global climate change, even if modestly, by helping reduce CO2 emissions from power plants and other sources as a result of decreased energy use for cooling (both direct and indirect) and reducing the rates of meteorology-dependent emissions of air pollutants. This presentation will highlight aspects and characteristics of heat islands, their mitigation, their modeling and quantification techniques, and recent advances in meso-urban modeling of California (funded by the California Energy Commission). In particular, the presentation will focus on results from quantitative, modeling-based analyses of the potential benefits of heat island mitigation in 1) reducing point- and area-source emissions of CO2, NOx, and VOC as a result of reduced cooling energy demand and ambient/surface temperatures, 2) reducing evaporative and fugitive hydrocarbon emissions as a result of lowered temperatures, 3) reducing biogenic hydrocarbon emissions from existing vegetative cover, 4) slowing the rates of tropospheric/ground-level ozone formation and/or accumulation in the urban boundary layer, and 5) helping improve air quality. Quantitative estimates
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Matsumura, Yuko; Miyoshi, Emako
2018-01-01
Japan, one of the most famous islander nations in the world, has promoted the development of its remote islands for over 60 years after the Second World War. The target islands and projects for fostering development have been steadily expanded. However, the country is facing serious socio-economic challenges such as aging and recession, resulting in less available funding for preferential treatment to remote islands. Thus, the framework for boosting island development should be reconsidered, ...
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Directory of Open Access Journals (Sweden)
Michael J Dunn
Full Text Available We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae, chinstrap (Pygoscelis antarctica and gentoo (Pygoscelis papua ellsworthii over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum, chinstrap penguins declined by 68% (-3.6% per annum and Adélie penguins declined by 42% (-1.5% per annum. The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a
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CpG island mapping by epigenome prediction.
Directory of Open Access Journals (Sweden)
Christoph Bock
2007-06-01
Full Text Available CpG islands were originally identified by epigenetic and functional properties, namely, absence of DNA methylation and frequent promoter association. However, this concept was quickly replaced by simple DNA sequence criteria, which allowed for genome-wide annotation of CpG islands in the absence of large-scale epigenetic datasets. Although widely used, the current CpG island criteria incur significant disadvantages: (1 reliance on arbitrary threshold parameters that bear little biological justification, (2 failure to account for widespread heterogeneity among CpG islands, and (3 apparent lack of specificity when applied to the human genome. This study is driven by the idea that a quantitative score of "CpG island strength" that incorporates epigenetic and functional aspects can help resolve these issues. We construct an epigenome prediction pipeline that links the DNA sequence of CpG islands to their epigenetic states, including DNA methylation, histone modifications, and chromatin accessibility. By training support vector machines on epigenetic data for CpG islands on human Chromosomes 21 and 22, we identify informative DNA attributes that correlate with open versus compact chromatin structures. These DNA attributes are used to predict the epigenetic states of all CpG islands genome-wide. Combining predictions for multiple epigenetic features, we estimate the inherent CpG island strength for each CpG island in the human genome, i.e., its inherent tendency to exhibit an open and transcriptionally competent chromatin structure. We extensively validate our results on independent datasets, showing that the CpG island strength predictions are applicable and informative across different tissues and cell types, and we derive improved maps of predicted "bona fide" CpG islands. The mapping of CpG islands by epigenome prediction is conceptually superior to identifying CpG islands by widely used sequence criteria since it links CpG island detection to
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CpG island mapping by epigenome prediction.
Bock, Christoph; Walter, Jörn; Paulsen, Martina; Lengauer, Thomas
2007-06-01
CpG islands were originally identified by epigenetic and functional properties, namely, absence of DNA methylation and frequent promoter association. However, this concept was quickly replaced by simple DNA sequence criteria, which allowed for genome-wide annotation of CpG islands in the absence of large-scale epigenetic datasets. Although widely used, the current CpG island criteria incur significant disadvantages: (1) reliance on arbitrary threshold parameters that bear little biological justification, (2) failure to account for widespread heterogeneity among CpG islands, and (3) apparent lack of specificity when applied to the human genome. This study is driven by the idea that a quantitative score of "CpG island strength" that incorporates epigenetic and functional aspects can help resolve these issues. We construct an epigenome prediction pipeline that links the DNA sequence of CpG islands to their epigenetic states, including DNA methylation, histone modifications, and chromatin accessibility. By training support vector machines on epigenetic data for CpG islands on human Chromosomes 21 and 22, we identify informative DNA attributes that correlate with open versus compact chromatin structures. These DNA attributes are used to predict the epigenetic states of all CpG islands genome-wide. Combining predictions for multiple epigenetic features, we estimate the inherent CpG island strength for each CpG island in the human genome, i.e., its inherent tendency to exhibit an open and transcriptionally competent chromatin structure. We extensively validate our results on independent datasets, showing that the CpG island strength predictions are applicable and informative across different tissues and cell types, and we derive improved maps of predicted "bona fide" CpG islands. The mapping of CpG islands by epigenome prediction is conceptually superior to identifying CpG islands by widely used sequence criteria since it links CpG island detection to their characteristic
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CRED Gridded Bathymetry of Nihoa Island (100-025) in the Northwestern Hawaiian Islands
National Oceanic and Atmospheric Administration, Department of Commerce — File 100-025b is a 60-m ASCII grid of depth data collected near Nihoa Island in the Northwestern Hawaiian Islands as of May 2003. This grid has been produced as part...
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Equilibrium theory of island biogeography: A review
Angela D. Yu; Simon A. Lei
2001-01-01
The topography, climatic pattern, location, and origin of islands generate unique patterns of species distribution. The equilibrium theory of island biogeography creates a general framework in which the study of taxon distribution and broad island trends may be conducted. Critical components of the equilibrium theory include the species-area relationship, island-...
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Carlson, D.F.; Boone, W.; Meire, L.; Abermann, J.; Rysgaard, S.
2017-01-01
Icebergs and bergy bits makes up a significant component of the total freshwater flux from the Greenland Ice Sheet to the ocean. Observations of iceberg trajectories are biased toward larger icebergs and, as a result, the drift characteristics of smaller icebergs and bergy bits are poorly
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Water resources of the Prairie Island Indian Reservation, Minnesota, 1994-97
Cowdery, Timothy K.
1999-01-01
This evaluation of the water resources on the Prairie Island Indian Reservation includes data collected from 8 surface-water sites and 22 wells during 1994–97 and historical data. The Mississippi River and the lakes and wetlands connected to it are separated from the Vermillion River and the lakes and wetlands connected to it by the surficial aquifer on Prairie Island and by Lock and Dam Number 3. These surface-water groups form hydrologic boundaries of the surficial aquifer. The aquifer is 130–200 feet thick, extends to bedrock (the Franconia Formation, which is also an aquifer), and is composed primarily of sand and gravel, but also contains thin, isolated lenses of finer-grained material. Flow in the surficial aquifer is normally from the Mississippi River to the Vermillion River (southwest). During spring snowmelt or heavy rains, a ground-water mound forms in the center of the study area and causes radial ground-water flow toward the surrounding surface waters.
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DeWitt, Nancy T.; Stalk, Chelsea A.; Fredericks, Jake J.; Flocks, James G.; Kelso, Kyle W.; Farmer, Andrew S.; Tuten, Thomas M.; Buster, Noreen A.
2018-04-13
The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center, in cooperation with the U.S. Army Corps of Engineers, Mobile District, conducted bathymetric surveys of the nearshore waters surrounding Ship and Horn Islands, Gulf Islands National Seashore, Mississippi. The objective of this study was to establish base-level elevation conditions around West Ship, East Ship, and Horn Islands and their associated active littoral system prior to restoration activities. These activities include the closure of Camille Cut and the placement of sediment in the littoral zone of East Ship Island. These surveys can be compared with future surveys to monitor sediment migration patterns post-restoration and can also be measured against historic bathymetric datasets to further our understanding of island evolution.The USGS collected 667 line-kilometers (km) of single-beam bathymetry data and 844 line-km of interferometric swath bathymetry data in July 2016 under Field Activity Number 2016-347-FA. Data are provided in three datums: (1) the International Terrestrial Reference Frame of 2000 (ellipsoid height); (2) the North American Datum of 1983 (NAD83) CORS96 realization and the North American Vertical Datum of 1988 with respect to the GEOID12B model (orthometric height); and (3) NAD83 (CORS96) and Mean Lower Low Water (tidal datum). Data products, including x,y,zpoint datasets, trackline shapefiles, digital and handwritten Field Activity Collection Systems logs, 50-meter digital elevation model, and formal Federal Geographic Data Committee metadata, are available for download.
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International Nuclear Information System (INIS)
Winson, A; Kinvig, H; Gottsmann, J; Partington, E; Geyer, A
2008-01-01
We present an analysis of volcanic threat of Nisyros island (Greece) based on a catalogue of questions compiled for the USGS National Volcano Early Warning System (NVEWS). We find that the score puts Nisyros in the league of volcanoes posing a very high threat. US volcanoes with a comparable threat level include Mt. St. Helens, Augustine and the Long Valley caldera.
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Energy Technology Data Exchange (ETDEWEB)
Winson, A; Kinvig, H; Gottsmann, J; Partington, E; Geyer, A [Department of Earth Sciences, University of Bristol (United Kingdom)
2008-10-01
We present an analysis of volcanic threat of Nisyros island (Greece) based on a catalogue of questions compiled for the USGS National Volcano Early Warning System (NVEWS). We find that the score puts Nisyros in the league of volcanoes posing a very high threat. US volcanoes with a comparable threat level include Mt. St. Helens, Augustine and the Long Valley caldera.
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Kuriiwa, Kaoru; Arihara, Hisashi; Chiba, Satoru; Kato, Shoichi; Senou, Hiroshi; Matsuura, Keiichi
2014-01-01
The Zunan Islands are located 360–650 km south of Tokyo, and consist of four uninhabited volcanoes: the Bayonnaise Rocks, the Smith Rocks, Torishima Island and the Sofugan Rock. Although all of the elements of the Zunan Islands are tiny islets and rocks, they form a series of stepping stones for shallow water fishes between the Izu Islands in the north and the Ogasawara (Bonin) Islands in the south. We report here the first comprehensive survey of marine fishes in the Zunan Islands. A total o...
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Ecology and Evolution: Islands of Change.
Benz, Richard
This book was designed for middle and junior high school science classes and focuses on island biogeography, ecology, and evolution. Sections include: (1) "Galapagos: Frame of Reference"; (2) "Ecology and Islands"; and (3) "Evolution." Nineteen standards-based activities use the Galapagos Islands as a running theme…
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Directory of Open Access Journals (Sweden)
Isabel Banos-González
2016-05-01
Full Text Available An integral dynamic model, in combination with other methods (indicators, policy and scenario analysis, is presented as a tool for sustainability assessment in island socio-ecological systems (SES. The Fuerteventura sustainability model (FSM, tested for the 1996-2011, allows a better understanding of the dynamic interactions between sustainability indicators and other factors of this island. The FSM was first applied to analyse the vulnerability of this island to climate change for the 2012-2025 period; results point to the need for urgent measures to mitigate its effects on some of the analysed indicators. A set of policy measures was then assessed from the behaviour of nine indicators and their sustainability thresholds. Finally, the FSM facilitated the development of a dynamic model of the island of El Hierro, extrapolating the features common to both SES. We propose this to be a useful tool for the quantitative sustainability assessment and the management of real island socio-ecological systems
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Energy Technology Data Exchange (ETDEWEB)
Foley, D.M. E-mail: dfoley@chapman.edu; Dufour, A.; Rodriguez, L.; Caporaso, F.; Prakash, A
2002-03-01
Lettuce was inoculated with a six-strain cocktail of acid-adapted Escherichia coli 0157:H7 at a level of 1x10{sup 7} CFU/g. Following chlorination at 200 {mu}g/ml, the lettuce was irradiated at 0.15, 0.38, or 0.55 kGy using a {sup 60}Co source. Survival of E. coli 0157:H7, aerobic mesophiles and yeast and molds were measured over a period of 10 days. For quality analysis, chlorinated lettuce was subjected to irradiation at 0.33 and 0.53 kGy and stored at 1.0 deg. C, 4.0 deg. C or 7.0 deg. C. Changes in texture and color were determined by instrumental means and changes in flavor, odor, and visual quality were determined by sensory testing. Chlorination plus irradiation at 0.55 kGy produced a 5.4-log reduction in E. coli 0157:H7 levels. Chlorination alone reduced the E. coli 0157:H7 counts by 1-2 logs. Irradiation at 0.55 kGy was also effective in reducing standard plate counts and yeast and mold counts. Irradiation at this level did not cause softening of lettuce and sensory attributes were not adversely affected. In general, appearance and flavor were affected more by the length of storage than by temperature conditions. The 5+log reduction in E. coli counts and lack of adverse effects on sensory attributes indicate that low-dose irradiation can improve the safety and shelf-life of fresh-cut iceberg lettuce for retail sale or food service.
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International Nuclear Information System (INIS)
Foley, D.M.; Dufour, A.; Rodriguez, L.; Caporaso, F.; Prakash, A.
2002-01-01
Lettuce was inoculated with a six-strain cocktail of acid-adapted Escherichia coli 0157:H7 at a level of 1x10 7 CFU/g. Following chlorination at 200 μg/ml, the lettuce was irradiated at 0.15, 0.38, or 0.55 kGy using a 60 Co source. Survival of E. coli 0157:H7, aerobic mesophiles and yeast and molds were measured over a period of 10 days. For quality analysis, chlorinated lettuce was subjected to irradiation at 0.33 and 0.53 kGy and stored at 1.0 deg. C, 4.0 deg. C or 7.0 deg. C. Changes in texture and color were determined by instrumental means and changes in flavor, odor, and visual quality were determined by sensory testing. Chlorination plus irradiation at 0.55 kGy produced a 5.4-log reduction in E. coli 0157:H7 levels. Chlorination alone reduced the E. coli 0157:H7 counts by 1-2 logs. Irradiation at 0.55 kGy was also effective in reducing standard plate counts and yeast and mold counts. Irradiation at this level did not cause softening of lettuce and sensory attributes were not adversely affected. In general, appearance and flavor were affected more by the length of storage than by temperature conditions. The 5+log reduction in E. coli counts and lack of adverse effects on sensory attributes indicate that low-dose irradiation can improve the safety and shelf-life of fresh-cut iceberg lettuce for retail sale or food service
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The Idea of the Archipelago: Contemplating Island Relations
Directory of Open Access Journals (Sweden)
Elaine Stratford
2013-05-01
Full Text Available Creative, innovative, and timely research on islands and island futures is warranted and pressing, not least because island(ers are poorly served by established tropes of them as subordinate to continents or mainlands. Opportunities exist to provide a more thoroughgoing account of island life and island relations, and the seven papers in this special issue address that task. In works that consider islands in the Timor Sea, the Caribbean, the Pacific, Atlantic and Southern Oceans, and that span several different disciplinary frames—archival-historical, critical theoretical, literary, cultural, geopolitical, sociological and artistic—these papers evidence both the diversity of approach to thinking with the archipelago, and numerous points in common. Among the latter is an understanding that island relations are built on connection, assemblage, mobility, and multiplicity, and a commitment to critically examine the ways in which these entanglements affect and give effect to island life. The models of island relationality brought to light by this collective focus on the archipelago reveal new and diverse connections of island peoples with their physical and cultural environments, and with the world beyond; create spaces for growing resilience, association and engagement; and invite further study.
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Holocene emerged coral reef in Takarajima and Kodakarajima, Ryukyu islands, Southwest Japan
International Nuclear Information System (INIS)
Nakata, Takashi; Omoto, Kunio; Koba, Motoharu
1978-01-01
Due to the recent development of radiometric dating, coral reefs emerged in Holocene epoch are studied intensively worldwidely in relation to sea level change and coral reef formation. Attempt was made to determine the age, pattern and growth rate of coral reefs in the marginal area of coral sea in the Northwest Pacific. Field observation was made in the emerged coral reefs in Takarajima and Kodakarajima islands and the samples for radiocarbon dating were taken from geological sections across the emerged reefs. These islands are located at about 29 deg 10 min N, 129 deg 15 min E, where warm Kuroshio current pushes the margin of coral sea northward, and furnished with flourishing development of coral reefs emerged in both pleistocence and Holocene epochs. Though without earthquake records, it is assumed that Holocene reefs have been terraced due to sudden uplift associated with major earthquakes. (Mori, K.)
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Holocene emerged coral reef in Takarajima and Kodakarajima, Ryukyu islands, Southwest Japan
Energy Technology Data Exchange (ETDEWEB)
Nakata, T; Omoto, K; Koba, M [Tohoku Univ., Sendai (Japan). Faculty of Science
1978-06-01
Due to the recent development of radiometric dating, coral reefs emerged in Holocene epoch are studied intensively worldwidely in relation to sea level change and coral reef formation. Attempt was made to determine the age, pattern and growth rate of coral reefs in the marginal area of coral sea in the Northwest Pacific. Field observation was made in the emerged coral reefs in Takarajima and Kodakarajima islands and the samples for radiocarbon dating were taken from geological sections across the emerged reefs. These islands are located at about 29 deg 10 min N, 129 deg 15 min E, where warm Kuroshio current pushes the margin of coral sea northward, and furnished with flourishing development of coral reefs emerged in both pleistocence and Holocene epochs. Though without earthquake records, it is assumed that Holocene reefs have been terraced due to sudden uplift associated with major earthquakes.
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seal Arctocephaius tropicaiis at Gough Island
African Journals Online (AJOL)
Population increase in the Amsterdam Island fur seal Arctocephaius tropicaiis at Gough Island. M.N. Bester. Mammal Research Institute, University of Pretoria, Pretoria. Population size of Arctocephalus tropicalis on Gough Island was determined by direct censuses of parts of the coast duro ing the summers of 1974 - 1976 ...
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Challenges in bimetallic multilayer structure formation: Pt growth on Cu monolayers on Ru(0001)
DEFF Research Database (Denmark)
Mancera, Luis A.; Engstfeld, Albert Kilian; Bensch, Andreas
2017-01-01
In a joint experimental and theoretical study, we investigated the formation and morphology of PtCu/Ru(0001) bimetallic surfaces grown at room and higher temperatures under UHV conditions. We obtained the PtCu/Ru(0001) surfaces by deposition of Pt atoms on a previously created Cu/Ru(0001) structure...... which includes only one Cu monolayer. Bimetallic surfaces prepared at different Pt coverages are investigated using STM imaging, revealing the existence of reconstruction lines and Cu islands. Although primarily created Cu islands continue growing in size by increasing Pt coverage, a continuous...
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Simple method for calculating island widths
International Nuclear Information System (INIS)
Cary, J.R.; Hanson, J.D.; Carreras, B.A.; Lynch, V.E.
1989-01-01
A simple method for calculating magnetic island widths has been developed. This method uses only information obtained from integrating along the closed field line at the island center. Thus, this method is computationally less intensive than the usual method of producing surfaces of section of sufficient detail to locate and resolve the island separatrix. This method has been implemented numerically and used to analyze the buss work islands of ATF. In this case the method proves to be accurate to at least within 30%. 7 refs
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Mosquito Surveys Carried out On Green Island, Orchid Island, and Penghu Island, Taiwan, in 2003
Directory of Open Access Journals (Sweden)
Hwa-Jen Teng
2005-02-01
Full Text Available Field surveys of mosquitoes were carried out on Green, Orchid, and Penghu Islands in 2003 to ascertain the status of mosquito vectors. Eighteen species of mosquitoes were collected, including three species of Anopheles, four species of Aedes, eight species of Culex, two species of Armigeres, and one species of Malaya. Seventeen previously recorded species were not collected in this study but 11 species collected had not previously been recorded. Ten newly recorded species, An. maculatus, An. takasagoensis, Ae. alcasidi, Ae. lineatopennis, Ae. vexans vexans, Ar. omissus, Cx. vishnui, Cx. halifaxii, Cx. hayashii, and Cx. neomimulus, were collected on Green Island and one previously unrecorded species, Ar. subalbatus, was collected on Orchid Island. Potential vectors An. maculatus and An. sinensis, malaria vectors in Korea and Mainland China, Ae. albopictus, a vector of dengue in Taiwan and West Nile virus in the USA, Cx. vishnui and Cx. tritaeniorhynchus, Japanese encephalitis vectors in Taiwan, Ae. vexans vexans, an eastern equine encephalitis vector in the USA, and Cx. quinquefasciatus, a vector of filariasis in Taiwan and West Nile virus in the USA, were among the mosquito species collected.
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Barrows, Timothy T.; Almond, Peter; Rose, Robert; Keith Fifield, L.; Mills, Stephanie C.; Tims, Stephen G.
2013-08-01
On the South Island of New Zealand, large piedmont glaciers descended from an ice cap on the Southern Alps onto the coastal plain of the West Coast during the late Pleistocene. The series of moraine belts and outwash plains left by the Taramakau glacier are used as a type section for interpreting the glacial geology and timing of major climatic events of New Zealand and also as a benchmark for comparison with the wider Southern Hemisphere. In this paper we review the chronology of advances by the Taramakau glacier during the last or Otira Glaciation using a combination of exposure dating using the cosmogenic nuclides 10Be and 36Cl, and tephrochronology. We document three distinct glacial maxima, represented by the Loopline, Larrikins and Moana Formations, separated by brief interstadials. We find that the Loopline Formation, originally attributed to Oxygen Isotope Chronozone 4, is much younger than previously thought, with an advance culminating around 24,900 ± 800 yr. The widespread late Pleistocene Kawakawa/Oruanui tephra stratigraphically lies immediately above it. This Formation has the same age previously attributed to the older part of the Larrikins Formation. Dating of the Larrikins Formation demonstrates there is no longer a basis for subdividing it into older and younger phases with an advance lasting about 1000 years between 20,800 ± 500 to 20,000 ± 400 yr. The Moana Formation represents the deposits of the last major advance of ice at 17,300 ± 500 yr and is younger than expected based on limited previous dating. The timing of major piedmont glaciation is restricted to between ˜25,000 and 17,000 yr and this interval corresponds to a time of regionally cold sea surface temperatures, expansion of grasslands at the expense of forest on South Island, and hemisphere wide glaciation.
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Setoguchi, H; Watanabe, I
2000-06-01
Hybridization and introgression play important roles in plant evolution, and their occurrence on the oceanic islands provides good examples of plant speciation and diversification. Restriction fragment length polymorphisms (RFLPs) and trnL (UAA) 3'exon-trnF (GAA) intergenic spacer (IGS) sequences of chloroplast DNA (cpDNA), and the sequences of internal transcribed spacer (ITS) of nuclear ribosomal DNA were examined to investigate the occurrence of gene transfer in Ilex species on the Bonin Islands and the Ryukyu Islands in Japan. A gene phylogeny for the plastid genome is in agreement with the morphologically based taxonomy, whereas the nuclear genome phylogeny clusters putatively unrelated endemics both on the Bonin and the Ryukyu Islands. Intersectional hybridization and nuclear gene flow were independently observed in insular endemics of Ilex on both sets of islands without evidence of plastid introgression. Gene flow observed in these island systems can be explained by ecological features of insular endemics, i.e., limits of distribution range or sympatric distribution in a small land area.
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Seed islands driven by turbulence and NTM dynamics
Muraglia, M.; Agullo, O.; Poye, A.; Benkadda, S.; Horton, W.; Dubuit, N.; Garbet, X.; Sen, A.
2014-10-01
Magnetic reconnection is an issue for tokamak plasmas. Growing magnetic islands expel energetic particles from the plasma core leading to high energy fluxes in the SOL and may cause damage to the plasma facing components. The islands grow from seeds from the bootstrap current effects that oppose the negative delta-prime producing nonlinear island growth. Experimentally, the onset of NTM is quantified in terms of the beta parameter and the sawtooth period. Indeed, in experiments, (3;2) NTM magnetic islands are often triggered by sawtooth precursors. However (2;1) magnetic islands can appear without noticeable MHD event and the seed islands origin for the NTM growth is still an open question. Macroscale MHD instabilities (magnetic islands) coexist with micro-scale turbulent fluctuations and zonal flows which impact island dynamics. Nonlinear simulations show that the nonlinear beating of the fastest growing small-scale ballooning interchange modes on a low order rational surface drive a magnetic islands located on the same surface. The island size is found to be controlled by the turbulence level and modifies the NTM threshold and dynamics.
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Introduced mammals on Western Indian Ocean islands
Directory of Open Access Journals (Sweden)
James C. Russell
2016-04-01
Full Text Available The diversity of introduced mammals and their introduction history varies greatly across the Western Indian Ocean (WIO islands, from ancient introductions in the past millennia on islands off the East coast of Africa where extant terrestrial native mammal communities exist, to very recent invasions in the past decades on islands in the Mascarene archipelago. We compile the distribution of 16 introduced mammal taxa on 28 island groups comprising almost 2000 islands. Through an exhaustive literature review and expert consultation process we recorded all mammal eradications, and species recoveries which could be attributed to introduced mammal eradication or control. All island groups have been invaded by mammals, and invasive cats and rats in particular are ubiquitous, but cultural contingency has also led to regional invasions by other mammals such as lemurs, civets and tenrecs. Mammal eradications have been attempted on 45 islands in the WIO, the majority in the Seychelles and Mauritius, and where successful have resulted in spectacular recovery of species and ecosystems. Invasive mammalian predator eradication or control in association with habitat management has led to improved conservation prospects for at least 24 species, and IUCN red-list down-listing of eight species, in the Mascarene Islands. Future island conservation prioritisation in the region will need to take account of global climate change and predicted sea-level rises and coastal inundation. Greater investment and prioritisation in island conservation in the region is warranted, given its high biodiversity values and the extent of invasions.
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International Nuclear Information System (INIS)
Des Brisay, C.
2005-01-01
Terasen Gas is pursuing alternatives for the supply of additional natural gas capacity to Vancouver Island. Its subsidiary, Terasen Gas (Vancouver Island) Inc. (TGVI), is responding to the need for delivery of increased gas supply and, is supporting plans for new gas-fired power generation on Vancouver Island. TGVI's proposal for new natural gas capacity involves a combination of compression and pipeline loops as well as the addition of a storage facility for liquefied natural gas (LNG) at Mt. Hayes to help manage price volatility. This presentation outlined the objectives and components of the resource planning process, including demand forecast scenarios and the preferred infrastructure options. tabs., figs
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Wieczyńska, Justyna; Cavoski, Ivana
2018-09-01
In this study, bio-based emitting sachets containing eugenol (EUG), carvacrol (CAR) and trans-anethole (ANT) were inserted into cellulose (CE) and polypropylene (PP) pillow packages of organic ready-to-eat (RTE) iceberg lettuce to investigate their functional features. EUG, CAR and ANT sachets in CE; and CAR in PP packages showed antimicrobial activities against coliforms (Δlog CFU g -1 of -1.38, -0.91, -0.93 and -0.93, respectively). EUG and ANT sachets in both packages reduced discoloration (ΔE of 9.5, 1.8, 9.4 and 5.6, respectively). ANT in both, and EUG only in PP packages induced biosynthesis of caffeoyl derivatives (C a T A , D i C a T A , D i C a Q A ), total phenolics and antioxidant activity (FRAP). Also, ANT and EUG in both packages improved overall freshness and odor. Principal component analysis separated ANT and EUG from CAR in both packages. The Pearson correlation confirmed that overall quality improvements were more pronounced by ANT inside the packages in comparison to EUG and CAR. Copyright © 2018 Elsevier Ltd. All rights reserved.
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International Nuclear Information System (INIS)
Kamaruzzaman Sopian
2000-01-01
Wind data collected at three east coast islands of Peninsular Malaysia namely Tioman, Redang and Perhentian Island were analyzed for the wind energy potential. The results were presented as Weibull distribution and preliminary analysis indicate that the site at Redang Island have the greatest potential with a mean power density of 85.1 w/m 2 at 10 meters above sea level. (Author)
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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.
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Terrestrial radiation measurements in Marshall Islands
International Nuclear Information System (INIS)
Gudiksen, P.H.
1978-01-01
With the prospect of habitation in the near future, radiological surveys were undertaken of Enewetak and Bikini Atolls to provide a basis for determining whether or not the atolls can be safely reinhabited. The surveys included all of the forty islands within Enewetak Atoll, but only the two principal islands, Bikini and Eneu Islands, of Bikini Atoll. These atolls were former U.S. nuclear weapons test sites in the Pacific. Integral parts of the surveys were the measurements of the distributions of radioactivity in the soil and the resulting gamma ray exposure rates for external dose estimation. Numerous soil samples were collected from both atolls for analysis by Ge (Li) gamma spectrometry and by wet chemistry techniques. At Enewetak Atoll the gamma exposure rates were measured by TLDs and a helicopter-borne array of Nal detectors, while at Bikini Atoll portable Nal detectors, pressurized ion-chambers, and TLDs were utilized. The predominant species measured in the soil samples collected from both atolls were 90 Sr, 239,240 Pu, 137 Cs and 60 Co with the latter two nuclides being the primary contributors to the gamma-ray exposure rates. The geographical distribution of the exposure rates measured on both atolls, was highly variable ranging from less than 1 μR/h on islands that had not been impacted radiologically by the testing program, to over 100 μR/h near weapon detonation sites. Thus, within Enewetak Atoll, the highest soil activities and gamma-ray exposure rates were measured on the northern islands, where the weapons testing had been most intense. Bikini Island exhibited contamination levels that were considerably higher than those on Eneu Island. Generally, the highest activity levels were observed within the island interiors or in proximity to ground zero sites, and could usually be related to the surrounding vegetation density. The island of Yvonne, within Enewetak Atoll, is the most severely contaminated land area. Particles containing as much as several
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Globally threatened vertebrates on islands with invasive species.
Spatz, Dena R; Zilliacus, Kelly M; Holmes, Nick D; Butchart, Stuart H M; Genovesi, Piero; Ceballos, Gerardo; Tershy, Bernie R; Croll, Donald A
2017-10-01
Global biodiversity loss is disproportionately rapid on islands, where invasive species are a major driver of extinctions. To inform conservation planning aimed at preventing extinctions, we identify the distribution and biogeographic patterns of highly threatened terrestrial vertebrates (classified by the International Union for Conservation of Nature) and invasive vertebrates on ~465,000 islands worldwide by conducting a comprehensive literature review and interviews with more than 500 experts. We found that 1189 highly threatened vertebrate species (319 amphibians, 282 reptiles, 296 birds, and 292 mammals) breed on 1288 islands. These taxa represent only 5% of Earth's terrestrial vertebrates and 41% of all highly threatened terrestrial vertebrates, which occur in vertebrates was available for 1030 islands (80% of islands with highly threatened vertebrates). Invasive vertebrates were absent from 24% of these islands, where biosecurity to prevent invasions is a critical management tool. On the 76% of islands where invasive vertebrates were present, management could benefit 39% of Earth's highly threatened vertebrates. Invasive mammals occurred in 97% of these islands, with Rattus sp. as the most common invasive vertebrate (78%; 609 islands). Our results provide an important baseline for identifying islands for invasive species eradication and other island conservation actions that reduce biodiversity loss.
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North Aegean island landscapes as ecomuseums: the case of Lesvos Island
Directory of Open Access Journals (Sweden)
Evangelos Pavlis
2017-05-01
Full Text Available The main advantage of the Aegean islands, in generating national, regional, or international competitiveness, compared to the areas on the continental mainland, is their natural and cultural assets, their cultural landscapes. Consequently, the organized utilization of cultural heritage, rich biodiversity, and the unique Aegean landscape, could make the islands attractive as places to live or work and help them fulfill their sustainability goals. Ecomuseums are ‘in situ’ museums, aimed at local communities and managed by them, aiming at the interpretation, protection, utilization, and promotion of natural and cultural assets of a place, and at the economic revival of marginal regions through the combinational development of small-scale tourism, local manufacturing, and primary production sectors. They could function as laboratories of sustainable development. The island of Lesvos has been selected as a case study for such a potential ecomuseum.
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Directory of Open Access Journals (Sweden)
Raoni Rebouças
Full Text Available Island Rule postulated that individuals on islands tend to dwarfism when individuals from mainland populations are large and to gigantism when mainland populations present small individuals. There has been much discussion about this rule, but only few studies were carried out aiming to reveal this pattern for anurans. Our study focused on measuring the size of individuals on islands and to find a possible pattern of size modification for insular anurans. Individuals were collected on continental islands, measured and compared to mainland populations. We selected four species with different natural history aspects during these analyses. Island parameters were compared to size of individuals in order to find an explanation to size modification. Three of the four species presented size shifting on islands. Ololygon trapicheiroi and Adenomera marmorata showed dwarfism, Boana albomarginata showed gigantism and in Thoropa miliaris there was no evident size modification. Allometric analysis also revealed differential modification, which might be a result of different selective pressures on islands in respect of mainland populations. Regression model explained most of the size modification in B. albomarginata, but not for the other species. Our results indicate that previous assumptions, usually proposed for mammals from older islands, do not fit to the anurans studied here. We support the assumption that size modification on islands are population-specific. Hence, in B. albomarginata some factor associated to competition, living area and isolation time might likely be responsible for gigantism on islands.
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Uro Island I – Game-based E-Learning in der Urologie
Directory of Open Access Journals (Sweden)
Dern, Peter
2009-02-01
Full Text Available Game-based Learning verspricht gegenüber traditionellen Lernformen eine höhere Motivation des Lernenden, indem Lerninhalte in einer hoch-interaktiven, Regel-kontrollierten und kompetitiven Form präsentiert werden, und fördert nicht nur die Anwendung kognitiver sondern auch affektiver und psycho-motorischer Fähigkeiten. Mit Uro Island I wird hier ein Spiel-basiertes E-Learning-Programm für die „Beurteilung pathologischer Urinbefunde“ präsentiert, das das Genre der Adventure-Games für die medizinische Lehre nutzbar macht. Dazu wurden didaktische Spiel-Elemente und Sequenzen für Adventure-Games entwickelt, die geeignet sind entsprechend der spezifischen Inhalte und ihrer Kontexte medizinisches Wissen zu vermitteln. In einer Nutzbarkeitsanalyse (n=14 konnte gezeigt werden, dass die Studierenden im Wesentlichen gut mit Uro Island I arbeiten konnten, wobei lediglich die zu umfangreiche Länge der Dialoge negativ bewertet wurde. Die Spiel-Elemente zur Wissensvermittlung wurden entsprechend der Komplexität der medizinischen Inhalte und der Erfahrung der Studierenden mit Computerspielen sehr unterschiedlich aber grundsätzlich positiv bewertet. Der Spielspaß ist trotz der medizinischen Inhalte des Spieles erhalten geblieben, so dass die meisten Studierenden auch weitere Module von Uro Island I spielen würden. Mit Uro Island I wurde ein Adventure-Game für die Urologische Lehre entwickelt, mit dem gezeigt werden kann, dass es möglich ist, den Lerninhalt einer kompletten urologischen Unterrichtseinheit in diesem Format effektiv abzubilden. Es ist gelungen in einzelnen Spiel-Elementen und Sequenzen komplexe medizinische Sachverhalte in diesem Genre abzubilden, wobei der Spielspaß erhalten geblieben ist.
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Ford, M.; Becker, J. M.; Merrifield, M. A.
2012-12-01
Atoll islands are highly vulnerable to a range of inundation hazards. The impacts of such hazards are expected to be magnified as a result of continued sea-level rise. Both recent and historic inundation events provide unique insights into the requisite conditions necessary to initiate island inundation. A number of recent and historic inundation events are presented in order to examine the oceanographic and meteorological conditions driving inundation of a densely populated, urbanized atoll in the central Pacific. Analysis of inundation events suggests that a number of key drivers contribute to the spatial and temporal extent of island inundation, with unique degrees of predictability and resultant impact signatures apparent on island geomorphology and local anthropogenic activities. Results indicate three distinct drivers of inundation hazards exist. Firstly, tropical storms and typhoons elevate sea level through inverse barometric setup, wind setup and a range of wave driven processes and have caused considerable impact on atolls within the Marshall Islands. Secondly, super-elevated sea level conditions resulting from the combination of seasonal high tides and quasi-cyclical La Nina conditions drive inundation of low-lying lagoon facing coastal areas. Thirdly, long period swell conditions, typically generated by distant storms, can elevate reef-flat water levels through wave setup and infragravity wave oscillations. Such wave conditions can over wash the ocean-facing island ridge, often inundating large sections of the island. Reef-flat wave conditions are tidally modulated, with inundation events typically occurring around high tide. However, the two most recent destructive swell-driven inundation events have occurred while tide levels were significantly lower than spring tide levels, suggesting high water levels are not a necessary prerequisite for wave-driven inundation. The different modes of inundation are discussed and grounded within recent and historic
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Chronic Liver Disease and Asian Americans/Pacific Islanders
... Cancer Asian/Pacific Islander Women Non-Hispanic White Women Asian/Pacific Islander/ Non-Hispanic White Ratio All Sites ... Cancer Asian/Pacific Islander Women Non-Hispanic White Women Asian/Pacific Islander/ Non-Hispanic White Ratio Liver & IBD* ...
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Solid waste management on small islands. The case of Green Island, Taiwan
Energy Technology Data Exchange (ETDEWEB)
Chen, M.C.; Ruijs, A.; Wesseler, J. [Environmental Economics and Natural Resources Group, Wageningen University, P.O. Box 8130, 6700 EW Wageningen (Netherlands)
2005-09-01
Municipalities of small islands have limited capacities for waste disposal. In the case of Green Island, Taiwan, continuing with business as usual would only allow the disposal of waste on the island for another 8 years. Three alternatives for solid waste management (SWM) are compared. The cost-effective solution is the one, which is the most expensive in the short run: continuing business as usual and introducing an incineration plant in the year 2010. The results indicate furthermore that deviations from optimal timing of investment only slightly change average annual costs. In the long run, the municipality can hardly avoid transporting waste to the mainland. By investing in an incineration plant, they can buy additional time to investigate alternative SWM strategies.
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National Oceanic and Atmospheric Administration, Department of Commerce — File 100-002b is a 60-m ASCII grid of depth data collected near Lisianski Island and Pioneer Bank in the Northwestern Hawaiian Islands as of May 2003. This grid has...
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Revisiting the Metaphor of the Island: Challenging "World Culture" from an Island Misunderstood
Rappleye, Jeremy
2015-01-01
This article revisits the newly "discovered" island that world culture theorists have repeatedly utilised to explain their theoretical stance, conceptual preferences and methodological approach. Yet, it seeks to (re)connect world culture with the real world by replacing their imagined atoll with a real one--the island-nation of Japan. In…
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Fisher, Robert N; Niukula, Jone; Watling, Dick; Harlow, Peter S
2017-06-06
The south Pacific iguanas (Brachylophus) currently have three recognized living species in Fiji. Recent surveys have uncovered more specific variation (morphological and genetic) within the genus and have better defined the geographic ranges of the named species. One of these recent discoveries is a strikingly different iguana from all other island populations in Fiji which is restricted to Gau Island of the Lomaiviti Province. Gau is the fifth largest island in Fiji and maintains excellent upland forests in the higher elevations. We describe this population from Gau Island as a new species, Brachylophus gau sp. nov., in recognition of its type locality.
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Fisher, Robert N.; Niukula, Jone; Watling, Dick; Harlow, Peter S.
2017-01-01
The south Pacific iguanas (Brachylophus) currently have three recognized living species in Fiji. Recent surveys have uncovered more specific variation (morphological and genetic) within the genus and have better defined the geographic ranges of the named species. One of these recent discoveries is a strikingly different iguana from all other island populations in Fiji which is restricted to Gau Island of the Lomaiviti Province. Gau is the fifth largest island in Fiji and maintains excellent upland forests in the higher elevations. We describe this population from Gau Island as a new species, Brachylophus gau sp. nov., in recognition of its type locality.
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Island forming processes in the Okavango Delta, Botswana
McCarthy, T. S.; Humphries, M. S.; Mahomed, I.; Le Roux, P.; Verhagen, B. Th.
2012-12-01
The Okavango Delta in Botswana is a large (40,000 km2) alluvial fan that is characterised by the presence of numerous tree-covered islands. Thought to originate from the mound-building activities of termites or through fluvial processes associated with development of scroll bars and inverted channels, islands have been shown to play an important role in the structure and functioning of the Delta through the creation of habitat diversity, focusing of nutrients, and disposal of toxic salts. This study investigates the processes responsible for the maintenance and growth of two such islands in the seasonal swamps. Transpiration by vegetation is shown to result in substantial increases in groundwater salinity beneath the islands, contributing to their growth through chemical precipitation. Detailed chemical analyses revealed that the precipitation of magnesian calcite and silica within the island soils contributes 30-40% of the total island volume. Isotopic analyses of carbonate samples show that vegetation plays an important role in providing carbon for carbonate precipitation. Variations in δ13C carbonate values appear to reflect the relative proportion of C3 to C4 plants on the island, with C4 species becoming more dominant toward island centres in response to increases in groundwater salinity. The study suggests that continued island growth is also related to the deposition of aerosols and the accumulation of dust preferentially on islands and possibly to ongoing termite activity. Tall trees that characterise the island margins trap dust carried from the floodplains, resulting particularly in the lateral growth of islands. Islands in the Okavango are considered to be the product of long-term aggradation processes, with the two islands studied estimated to be in the order of tens of thousands of years old.
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Origin of ultramafic-hosted magnesite on Margarita Island, Venezuela
Abu-Jaber, N. S.; Kimberley, M. M.
1992-06-01
Ultramafic-hosted deposits of magnesite (MgCO3) have been studied on Margarita Island, Venezuela, to elucidate the source of carbon and conditions of formation for this type of ore. Petrographic, mineralogic, and δ18O data indicate that magnesite precipitated on Margarita in near-surface environments at low P and T. δ13C ranges from -9 to -16‰ PDB within the magnesite and -8 to -10‰ PDB within some calcite and dolomite elsewhere on the island. The isotopically light dolomite fills karst and the calcite occurs as stock-work veins which resemble the magnesite deposits. These carbon isotopic ratios are consistent with a deep-seated source rather than an overlying source from a zone of surficial weathering. However, there is not much enrichment of precious metals and no enrichment of heavy rare-earth elements, as would be expected if the carbon had migrated upward as aqueous carbonate ions. The carbon probably has risen as a gaseous mixture of CO2 and CH4 which partially dissolved in near-surface water before leaching cations and precipitating as magnesite and other carbonates. The process probably is ongoing, given regional exhalation of carbonaceous gases.
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Geomorphological control on podzolisation - An example from a tropical barrier island
Martinez, Pedro; Buurman, Peter; Lopes-Mazzetto, Josiane Millani; Giannini, Paulo César Fonseca; Schellekens, Judith; Vidal-Torrado, Pablo
2018-05-01
We investigated how the geomorphology of coastal barrier islands impacts soil hydrology and drainage at the landscape scale. Ilha Comprida is a Holocene barrier island with a 2.5 km-long cliff that is perpendicular to the coastal shore which provides an ideal condition to study the relation between age, relief, hydrology, and podzol morphology. Five geomorphic units were identified that differed in surface morphology and alignment of ridges and swales. Optical stimulated luminescence (OSL) dating showed that these geomorphic units had growth phases that decreased in age from west to east (Units I-V, from 5250 ± 820 to 325 ± 31 years ago, respectively). The geomorphic units were studied in two parallel 3 km transects on the southern part of the island. Along transect A-B, about 1 km from the southern shore, deep augerings were used to study sedimentary sequence and soil development, while on transect C-D on the southern shore, the continuous cliff exposure allowed more detailed morphological investigation. On all geomorphic units excluding the youngest, podzolisation has been the main soil-forming process. Groundwater level was monitored monthly for two years in 14 deep wells along transect A-B. Groundwater level during the formation of the B horizon was ascertained by determination of Fe. Podzol morphology (color of B horizon and its boundary with the E horizon) generally showed correlation to groundwater levels for both transects, except for the podzols in southwestern part of the island (Unit II). The podzols of Unit II showed an extremely thick (3 m) Bhm horizon devoid of Fe, indicating that they were formed under poor drainage conditions. However, soil morphology (undulating EB horizon boundary) and measured groundwater levels (below the B horizons) demonstrated that drainage has been improved. The extremely thick B horizon (3 m) in those podzols, which was formed in approximately 3000 years, and its genesis is explained by concentrated lateral flow of DOM
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Review of islanding detection methods for distributed generation
DEFF Research Database (Denmark)
Chen, Zhe; Mahat, Pukar; Bak-Jensen, Birgitte
2008-01-01
This paper presents an overview of power system islanding and islanding detection techniques. Islanding detection techniques, for a distribution system with distributed generation (DG), can broadly be divided into remote and local techniques. A remote islanding detection technique is associated...
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International Nuclear Information System (INIS)
Ding, Haitao; Shao, Jinyou; Ding, Yucheng; Liu, Weiyu; Li, Xiangming; Tian, Hongmiao; Zhou, Yaopei
2015-01-01
Highlights: • Conductive island shape influences the dynamic process occurring in DEP assembly of 10 nm gold nanoparticles in a conductive-island-based microelectrode system. • The DEP-assembled nanoparticle wires form a straighter conduction path with the increase in the geometric angle of conductive island tip. • The different island shapes distort the DEP force distribution and increase the local electrothermally induced fluid flow to different extents, which is important for the morphology and electrical conductance quality of the DEP-assembled metal nanoparticle chains. - Abstract: The electrical conduction quality of an electric circuit connection formed by dielectrophoretic (DEP)-assembled metal nanoparticle wires between small conductive elements plays a significant role in electronic devices. One of the major challenges for improving the electrical conductance of nanowires is optimizing their geometric morphology. So far, the electrical conduction quality has been enhanced by optimizing the AC frequency and conductivity of nanoparticle suspensions. Herein, the effect of the conductive island shapes on the dynamic process occurring in a DEP assembly of 10 nm gold nanoparticles was investigated in a conductive-island-based microelectrode system. The nanoparticle wires between the microelectrodes were assembled in situ from colloidal suspensions. The wires were grown in a much straighter route by increasing the geometric angle of the conductive-island tip. To validate the experiments, the effects of mutual DEP interactions and electrothermally induced fluid flow on the dynamic behavior of particle motion for different island geometric configurations in the conductive-island-based microelectrode system were determined by numerical simulations. The simulation results are consistent with those of experiments. This indicates that different conductive island shapes change the distribution of DEP force and increase the electrothermally induced fluid flow to
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Bloor, P; Kemp, S J; Brown, R P
2008-02-01
The phylogeography of the lacertid lizard Gallotia atlantica from the small volcanic island of Lanzarote (Canary Islands) was analysed based on 1075 bp of mitochondrial DNA (mtDNA) sequence (partial cytochrome b and ND2) for 157 individuals from 27 sites (including three sites from neighbouring islets). Levels of sequence divergence were generally low, with the most distant haplotypes separated by only 14 mutational steps. MtDNA divergence appears to coincide with formation of the middle Pleistocene lowland that united formerly separate ancient islands to form the current island of Lanzarote, allowing rejection of a two-island model of phylogeographical structure. There was evidence of large-scale population expansion after island unification, consistent with the colonization of new areas. A nested clade phylogeographical analysis (NCPA) revealed significant phylogeographical structuring. Two-step and higher-level clades each had disjunct distributions, being found to the east and west of a common area with a north-south orientation that extends between coasts in the centre-east of the island (El Jable). Other clades were almost entirely restricted to the El Jable region alone. Bayesian Markov chain Monte Carlo analyses were used to separate ongoing gene flow from historical associations. These supported the NCPA by indicating recent (75,000-150,000 years ago) east-west vicariance across the El Jable region. Lava flows covered El Jable and other parts of the central lowland at this time and likely led to population extinctions and temporary dispersal barriers, although present-day evidence suggests some populations would have survived in small refugia. Expansion of the latter appears to explain the presence of a clade located between the eastern and western components of the disjunct clades. Direct relationships between mtDNA lineages and morphology were not found, although one of two morphological forms on the island has a disjunct distribution that is broadly
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International Nuclear Information System (INIS)
Maragos, J.E.; Agegian, Catherine
1986-01-01
This environmental assessment evaluates various alternatives to return the Bikini people to their homeland on Bikini Atoll. Eneu Island was spared the heavy nuclear contamination that rendered Bikini Island, the largest and main inhabitable island on the atoll, presently unsuitable for resettlement. The economic, social, technical and environmental consequences of all alternatives were compared, and alternative sites, purposes and scales for resettlement were included in the analysis. This environmental assessment explores these alternatives in detail and concludes that the resettlement of Eneu Island by some of the Bikini people at this time will not result in significant adverse effects to the environment nor will it foreclose any other full scale resettlement option involving the cleanup of Bikini Atoll. In addition, it concludes that the resettlement of Eneu can be accomplished independently from the planned cleanup and resettlement of Bikini Island. Plans and combination of plans involving the early resettlement of Eneu are fully feasible and implementable at this time. (author)
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Energy Technology Data Exchange (ETDEWEB)
Maragos, J E [Environmental Resources Section, U.S. Army Corps of Engineers, Pacific Ocean Division, HI (United States); Agegian, Catherine [University of Hawaii, Department of Oceanography, Honolulu, HI (United States)
1986-07-01
This environmental assessment evaluates various alternatives to return the Bikini people to their homeland on Bikini Atoll. Eneu Island was spared the heavy nuclear contamination that rendered Bikini Island, the largest and main inhabitable island on the atoll, presently unsuitable for resettlement. The economic, social, technical and environmental consequences of all alternatives were compared, and alternative sites, purposes and scales for resettlement were included in the analysis. This environmental assessment explores these alternatives in detail and concludes that the resettlement of Eneu Island by some of the Bikini people at this time will not result in significant adverse effects to the environment nor will it foreclose any other full scale resettlement option involving the cleanup of Bikini Atoll. In addition, it concludes that the resettlement of Eneu can be accomplished independently from the planned cleanup and resettlement of Bikini Island. Plans and combination of plans involving the early resettlement of Eneu are fully feasible and implementable at this time. (author)
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of the Northwestern Hawaiian Islands, USA within UTM Zone 2. Bottom coverage was...
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of the Northwestern Hawaiian Islands, USA within UTM Zone 2. Bottom coverage was...
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of the Northwestern Hawaiian Islands, USA within UTM Zone 3. Bottom coverage was...
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of the Northwestern Hawaiian Islands, USA within UTM Zone 3. Bottom coverage was...
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National Oceanic and Atmospheric Administration, Department of Commerce — Gridded bathymetry and IKONOS estimated depths of the shelf and slope environments of the Northwestern Hawaiian Islands, USA within UTM Zone 1. Bottom coverage was...
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Assessing qualitative long-term volcanic hazards at Lanzarote Island (Canary Islands)
Becerril, Laura; Martí, Joan; Bartolini, Stefania; Geyer, Adelina
2017-07-01
Conducting long-term hazard assessment in active volcanic areas is of primary importance for land-use planning and defining emergency plans able to be applied in case of a crisis. A definition of scenario hazard maps helps to mitigate the consequences of future eruptions by anticipating the events that may occur. Lanzarote is an active volcanic island that has hosted the largest (> 1.5 km3 DRE) and longest (6 years) eruption, the Timanfaya eruption (1730-1736), on the Canary Islands in historical times (last 600 years). This eruption brought severe economic losses and forced local people to migrate. In spite of all these facts, no comprehensive hazard assessment or hazard maps have been developed for the island. In this work, we present an integrated long-term volcanic hazard evaluation using a systematic methodology that includes spatial analysis and simulations of the most probable eruptive scenarios.
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Ramjan, S.; Mahmud, M. S.; Hossain, M. A.; Hasan, M.; Ashrafi, Z. M.
2016-12-01
Bangladesh is recognized for its high vulnerability to sea level rise (SLR). SLR directly and indirectly (by altering morphology of river estuary) accelerates erosion processes, washes out the loose materials of the coast and coastal islands. Hatiya, highly populated coastal island, located in Meghna river estuary is under severe threat of coastal erosion, which has not been quantified yet. The accurate mapping of the shoreline and coastal changes are very important for adopting conservation measures e.g. protection of human life, property and the natural environment. The objectives of the present study are to use remote sensing and Geographical Information System techniques to evaluate spatial and temporal changes in the shoreline and coastal land area of the Hatiya Island between the year of 1985 and 2016 from multi-temporal satellite images, i.e. assessing shifting of the shoreline position through digital shoreline analysis besides the erosion-accretion measurements. Study reveals that about 67 square kilometer areas has been lost between 1985 and 2016 which was about 17 percent of original area (1985). Erosion mainly took place in northern, north-western banks of the island. In these areas, the landward movement and rate of the shoreline were higher with a highest value of the net shoreline movement (NSM) around 6.2 km. Erosion rate is significant in exposed part of the island where tidal water pressure, shoreline configuration, loose bank materials and steep slope were observed. However, the accretion was noticed in recent years (2010-2016) in southern part of the island where slopes were gentle, perhaps due to backwash sediment deposition. As erosion process is prominent in this island, significant amounnt of usable land was lost. Therefore, local livelihood pattern has changed that has noticable effect on local economy. By quantifying the erosion-accretion rate, livelihood planning can be initiated in climatically threated vulnerable islands.
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Rising sea levels and small island states
International Nuclear Information System (INIS)
Leatherman, S.P.
1994-01-01
A review is given of the problems small island nations face with respect to sea level rise caused by global warming. Many small island nations are very vulnerable to sea level rise. Particularly at risk are coral reef atolls, which are generally quite small, lie within three metres of current sea levels, and have no land at higher elevations to relocate populations and economic activity. Volcanic islands in the Pacific have high ground, but it is largely rugged, high relief and soil-poor. The most vulnerable islands are those that consist entirely of atolls and reef islands, such as Kirabai, Maldives, Tokelau and Tuvalu. Small island states, which by themselves have little power or influence in world affairs, have banded together to form the Strategic Alliance of Small Island States (AOSIS). This alliance had grown to include 42 states by the time of the 1992 U.N. Earth Summit. Although the greenhouse effect is mainly caused by industrial nations, developing countries will suffer the most from it. Choices of response strategy will depend on environmental, economic and social factors. Most small island nations do not have the resources to fight sea level rise in the way that the Dutch have. Retreat can occur as a gradual process or as catastrophic abandonment. Prohibiting construction close to the water's edge is a good approach. Sea level histories for each island state should be compiled and updated, island geomorphology and settlement patterns should be surveyed to determine risk areas, storm regimes should be determined, and information on coastal impacts of sea level rise should be disseminated to the public
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Vicia vulcanorum (Fabaceae a new species from the island of Lanzarote (Canary Islands
Directory of Open Access Journals (Sweden)
Morales-Mateos, J. B.
2012-12-01
Full Text Available Vicia vulcanorum J. Gil & M. L. Gil (Fabaceae, a new species of subg. Cracca (Dumort. Peterm., sect. Cracca Dumort. is described and illustrated from the island of Lanzarote, Canary Islands, north-west of Africa. It is related to and compared with Vicia cirrhosa C. Sm. ex Webb & Berthel. and Vicia filicaulis Webb & Berthel., two endemic species from the western and central group of the Canary Islands, and Vicia ferreirensis Goyder, an endemic species from Porto Santo Island, Madeira Archipelago.Se describe e ilustra Vicia vulcanorum J. Gil & M. L. Gil (Fabaceae, una nueva especie y endemismo de la isla de Lanzarote, Islas Canarias, perteneciente al subg. Cracca (Dumort. Peterm., sect. Cracca Dumort. Se encuentra relacionada y es comparada con Vicia cirrhosa C. Sm. ex Webb & Berthel. y Vicia filicaulis Webb & Berthel., especies endémicas de las islas centrales y occidentales del archipiélago canario, y con Vicia ferreirensis Goyder, especie endémica de la isla de Porto Santo, en el archipiélago de Madeira.
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Neoclassical islands on COMPASS-D
International Nuclear Information System (INIS)
Gates, D.A.; Lloyd, B.; Morris, A.W.; McArdle, G.; O'Brien, M.R.; Valovic, M.; Warrick, C.D.; Wilson, H.R.
1997-01-01
Neoclassical magnetic islands are observed to limit the achievable β in COMPASS-D low collisionality single null divertor tokamak plasmas with ITER-like geometry (R 0 = 0.56 m, B 0 1.2 T, I p = 120-180 kA, κ = 1.6, ε = 0.3). The limiting β is typically well below that expected from ideal instabilities with maximum βN in the range of 1.6 to 2.1. The plasma is heated with up to 1.8 MW of 60 GHz electron cyclotron resonance heating (ECRH) at the second harmonic with X mode polarization. The time history of the measured island width is compared with the predictions of neoclassical tearing mode theory, with good agreement between theory and experiment. The measured islands have a threshold width below which the mode will not grow. The density scaling of the point of onset of the measured instabilities is compared with two theories that predict a threshold island width for the onset of neoclassical tearing modes. Applied resonant helical error fields are used to induce islands in collisionality regimes wherein the neoclassical islands do not occur naturally, allowing the study of the behaviour of neoclassical tearing modes in this regime. The critical β for the onset of neoclassical tearing modes is seen to be ∼3 times higher in the naturally stable region. This observation is compared with the predictions of both threshold theories. A simple expression for the q scaling of the maximum achievable β N in the presence of neoclassical tearing modes is derived on the basis of the assumption of a maximum allowable island width. The predicted q scaling of this β limit is compared with data from a q scan, and the results are in good agreement. (author)
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Directory of Open Access Journals (Sweden)
Desiderio Juan García-Almeida
2017-05-01
Full Text Available This paper sheds light on the relationship between immigration and tourism competitiveness on the island of Lanzarote through the analysis of reputation from the demand perspective. The tourists’ knowledge about news on immigration from a destination, their contact with immigrants in the area, and the influence of the presence of immigrants there are studied, as all these factors can have a major impact on island competitiveness in tourism. The empirical work has been conducted with a survey of tourists on Lanzarote, Canary Islands, Spain. A total of 359 valid questionnaires were obtained. Results show a relatively low impact and retention of immigration news about the destination, and a low perceived contact with non-European immigrants when visiting the island. Moreover, tourists tend to recognize the positive value created by immigrants on the island, though some negative effects are also indicated. Finally, immigration seems to have a positive impact on the tourist’s global satisfaction and loyalty to the island destination.
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Geology and ground-water resources of the island of Kauai, Hawaii
Macdonald, Gordon A.; Davis, Dan A.; Cox, Doak C.
1960-01-01
Kauai is one of the oldest, and is structurally the most complicated, of the Hawaiian Islands. Like the others, it consists principally of a huge shield volcano, built up from the sea floor by many thousands of thin flows of basaltic lava. The volume of the Kauai shield was on the order of 1,000 cubic miles. Through much of its growth it must have resembled rather closely the presently active shield volcano Mauna Loa, on the island of Hawaii. When the Kauai volcano started its growth is not known with certainty, but it is believed that activity started late in the Tertiary period, possibly in the early or middle part of the Pliocene epoch. Growth of the shield was rapid and probably was completed before the end of the Pliocene.Toward the end of the growth of the shield, its summit collapsed to form a broad caldera, the largest that has been found in the Hawaiian Islands. Like the calderas of Kilauea and Mauna Loa, that of Kauai volcano had boundaries that were, in part, rather indefinite. The principal depression was bordered by less depressed fault blocks, some of which merged imperceptibly with the outer slopes of the volcano. Elsewhere the caldera rim was low, and flows spilled over it onto the outer slopes. The well-defined central depression of the Kauai caldera was approximately 10 to 12 miles across.At about the same time as the formation of the major caldera, another, smaller caldera was formed by collapse around a minor eruptive center on the southeastern side of the Kauai shield. Lavas accumulated in the calderas, gradually filling them and burying banks of talus that formed along the foot of the boundary cliffs. The caldera-filling lavas differed from those that built the major portion of the shield in being much thicker and more massive as a result of ponding in the depressions. The petrographic types for the most part are the same throughout. Both the flank flows that built most of the shield and the flows that filled the calderas are predominantly
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Backscatter 0.5m TIFF Mosaic of St. Croix (Buck Island), US Virgin Islands, 2004
National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 0.5 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands. NOAA's NOS/NCCOS/CCMA Biogeography...
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Directory of Open Access Journals (Sweden)
Eli Sarnat
2013-01-01
Full Text Available The intent of this paper is to facilitate future research of the Solomon Islands ant fauna by providing the first comprehensively researched species inventory in over 75 years. The species list presented here includes the names of all ant species recorded from the islands that are available in the literature together with specimen records from several museum collections and new records from our 2008 Makira field expedition. All the names of described species presented are valid in accordance with the most recent Formicidae classification. In total, the checklist is composed of 237 species and subspecies (including 30 morphospecies in 59 genera representing nine subfamilies. We report that the recent field expedition added 67 new species records to Makira and 28 new species records to the Solomon Islands. Our research recovered species occurrence records for 32 individual islands and five island groups. The five islands with the highest number of recorded species are: Makira (142 spp., Guadalcanal (107 spp., Malaita (70 spp., Santa Isabel (68 spp., and Rennell (66 spp.. Based on our results, we discuss the taxonomic composition of the archipelago’s ant fauna, which islands are most in need of additional sampling, and the importance of establishing biodiversity baselines before environmental threats such as the invasive ant Wasmannia auropunctata cause irrevocable harm to the native biodiversity.
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Reduction of Islands in Full-pressure Stellarator Equilibria
International Nuclear Information System (INIS)
Hudson, S.R.; Monticello, D.A.; Reiman, A.H.
2001-01-01
The control of magnetic islands is a crucial issue in designing Stellarators. Islands are associated with resonant radial magnetic fields at rational rotational-transform surfaces and can lead to chaos and poor plasma confinement. In this article, we show that variations in the resonant fields of a full-pressure stellarator equilibrium can be related to variations in the boundary via a coupling matrix, and inversion of this matrix determines a boundary modification for which the island content is significantly reduced. The numerical procedure is described and the results of island optimization are presented. Equilibria with islands are computed using the Princeton Iterative Equilibrium Solver, and resonant radial fields are calculated via construction of quadratic-flux-minimizing surfaces. A design candidate for the National Compact Stellarator Experiment [Phys. Plasmas 8, 2001], which has a large island, is used to illustrate the technique. Small variations in the boundary shape are used to reduce island size and to reverse the phase of a major island chain
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36 CFR 13.1178 - Closed waters, islands and other areas.
2010-07-01
... southeast of Flapjack Island; or Eider Island; or Boulder Island; or Geikie Rock; or Lone Island; or the... islands) of the easternmost point of Russell Island; or Graves Rocks (on the outer coast); or Cormorant... and Preserve Vessel Operating Restrictions § 13.1178 Closed waters, islands and other areas. The...
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Formation of aeolian dunes on Anholt, Denmark since AD 1560
DEFF Research Database (Denmark)
Clemmensen, Lars B; Bjørnsen, Mette; Murray, Andrew
2007-01-01
Sand dunes on the island of Anholt (Denmark) in the middle of Kattegat form a relatively barren, temperate climate Aeolian system, locally termed the "Desert". The dunes have developed on top of a raised beach ridge system under the influence of dominant winds from westerly directions. They are r......Sand dunes on the island of Anholt (Denmark) in the middle of Kattegat form a relatively barren, temperate climate Aeolian system, locally termed the "Desert". The dunes have developed on top of a raised beach ridge system under the influence of dominant winds from westerly directions....... They are relatively coarse-grained with an average mean grain size of 480 µm. The last phase of aeolian activity and dune formation on Anholt started after AD 1560, when the local pine forest was removed. Historical sources report intense sand mobilization in the 17th century, and new optically stimulated...... in the beginning of the 20th century probably records a temporary decrease in storminess. Ground-penetrating radar mapping of the internal structures in two dunes in the western part of the Desert (a parabolic dune and a linear dune) indicates the importance of north-westerly (storm) winds during dune formation...
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Functional and phylogenetic structure of island bird communities.
Si, Xingfeng; Cadotte, Marc W; Zeng, Di; Baselga, Andrés; Zhao, Yuhao; Li, Jiaqi; Wu, Yiru; Wang, Siyu; Ding, Ping
2017-05-01
Biodiversity change in anthropogenically transformed habitats is often nonrandom, yet the nature and importance of the different mechanisms shaping community structure are unclear. Here, we extend the classic Theory of Island Biogeography (TIB) to account for nonrandom processes by incorporating species traits and phylogenetic relationships into a study of faunal relaxation following habitat loss and fragmentation. Two possible mechanisms can create nonrandom community patterns on fragment islands. First, small and isolated islands might consist of similar or closely related species because they are environmentally homogeneous or select for certain shared traits, such as dispersal ability. Alternatively, communities on small islands might contain more dissimilar or distantly related species than on large islands because limited space and resource availability result in greater competitive exclusion among species with high niche overlap. Breeding birds were surveyed on 36 islands and two mainland sites annually from 2010 to 2014 in the Thousand Island Lake region, China. We assessed community structure of breeding birds on these subtropical land-bridge islands by integrating species' trait and evolutionary distances. We additionally analysed habitat heterogeneity and variance in size ratios to distinguish biotic and abiotic processes of community assembly. Results showed that functional-phylogenetic diversity increased with island area, and decreased with isolation. Bird communities on the mainland were more diverse and generally less clustered than island bird communities and not different than randomly assembled communities. Bird communities on islands tend to be functionally similar and phylogenetically clustered, especially on small and isolated islands. The nonrandom decline in species diversity and change in bird community structure with island area and isolation, along with the relatively homogeneous habitats on small islands, support the environmental
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Urban heat island and linkage with air quality
International Nuclear Information System (INIS)
Greuillet, C.; Galsomies, L.
2013-01-01
The urban heat island (UHI) effect can be noticed in cities where the temperature is higher than the surrounding countryside, on average 2 deg. C above. In summer during a heat wave, the gap can up to over ten-degree. UHI causes a thermal stress which induces some repercussions on health. The formation of UHI is more and more documented but further studies have to be conducted in order to qualify and quantify the impacts on our health and environment, and the link with atmospheric pollution. Studies have shown air quality deterioration in UHI areas: Both phenomena can be simultaneous because their conditions of appearance are often linked. Henceforth the stake is to manage and if possible reduce UHI to adapt cities to the expected climate change. Dense cities in the future will also have to be naturally cooled down. In order to do so, we will have to act on the most influential UHI formation factors, namely: vegetation and water, buildings (shapes and materials), production and consumption of energy. (authors)
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Deer Island Aquatic Ecosystem Restoration Project
2015-07-01
across the U.S. Army Corps of Engineers (USACE) requires that a broad base of EWN understanding and support be built . The Deer Island Aquatic...USACE) requires that a broad base of EWN understanding and support be built . The Deer Island Aquatic Ecosystem Restoration Project (Deer Island AERP...Mississippi Wetlands Restoration Projects). The project received additional funding through several public laws in response to hurricane damages
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Facile synthesis and photoluminescence spectroscopy of 3D-triangular GaN nano prism islands.
Kumar, Mukesh; Pasha, S K; Shibin Krishna, T C; Singh, Avanish Pratap; Kumar, Pawan; Gupta, Bipin Kumar; Gupta, Govind
2014-08-21
We report a strategy for fabrication of 3D triangular GaN nano prism islands (TGNPI) grown on Ga/Si(553) substrate at low temperature by N2(+) ions implantation using a sputtering gun technique. The annealing of Ga/Si(553) (600 °C) followed by nitridation (2 keV) shows the formation of high quality GaN TGNPI cross-section. TGNPI morphology has been confirmed by atomic force microscopy. Furthermore, these nano prism islands exhibit prominent ultra-violet luminescence peaking at 366 nm upon 325 nm excitation wavelength along with a low intensity yellow luminescence broad peak at 545 nm which characterizes low defects density TGNPI. Furthermore, the time-resolved spectroscopy of luminescent TGNPI in nanoseconds holds promise for its futuristic application in next generation UV-based sensors as well as many portable optoelectronic devices.
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Sedimentary Fatty Alcohols in Kapas Island, Terengganu
International Nuclear Information System (INIS)
Noor Farahin Amiruddin; Mohamad Iznul Muazim Mohamad Zabidi; Nurul Fathihah Mt Nanyan; Masni Mohd Ali; Masni Mohd Ali
2015-01-01
A geochemical study was carried out to identify the composition and sources of fatty alcohols in Kapas Island, Terengganu, Malaysia. Fatty alcohols in surface sediments were extracted and analyzed using Gas Chromatography - Mass Spectrometry (GC-MS). A total of 23 fatty alcohol compounds were identified in the Kapas Island sediment. Total concentrations of fatty alcohols ranged from 0.53 to 21.31 ng/ g dry weight and the highest total concentration was found at S2, which is probably due to its location profile that is located north of Kapas Island which is close to several small islands. The short chain/ long chain fatty alcohol ratio and alcohol source index (ASI) were used together to identify the dominant input in Kapas Island. Kapas Island sediments contained a mixture of organic sources, of which terrestrial sources were indicated to be the most abundant sources in these marine sediments. (author)
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Assessing qualitative long-term volcanic hazards at Lanzarote Island (Canary Islands
Directory of Open Access Journals (Sweden)
L. Becerril
2017-07-01
Full Text Available Conducting long-term hazard assessment in active volcanic areas is of primary importance for land-use planning and defining emergency plans able to be applied in case of a crisis. A definition of scenario hazard maps helps to mitigate the consequences of future eruptions by anticipating the events that may occur. Lanzarote is an active volcanic island that has hosted the largest (> 1.5 km3 DRE and longest (6 years eruption, the Timanfaya eruption (1730–1736, on the Canary Islands in historical times (last 600 years. This eruption brought severe economic losses and forced local people to migrate. In spite of all these facts, no comprehensive hazard assessment or hazard maps have been developed for the island. In this work, we present an integrated long-term volcanic hazard evaluation using a systematic methodology that includes spatial analysis and simulations of the most probable eruptive scenarios.
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Fuelwood production in Prince Edward Island
International Nuclear Information System (INIS)
McCallum, B.
1992-01-01
The most recent Prince Edward Island Fuelwood Survey occurred in 1990-91. Consumption of fuelwood rose again to 49% of Prince Edward Island's 43,170 households. Total residential fuelwood consumption was estimated to be 242,000 m 3 . The fuelwood industry makes an important contribution to the economy of Prince Edward Island. In the 1990-91 heating season, fuelwood valued at USD 9 million displaced approximately 43 million litres of domestic heating oil valued at USD 16.4 million. In addition, it is estimated that 70 cents of every dollar spent on fuelwood remains in the province and contributes spin-off benefits, whereas 90 cents of every dollar spent on heating oil is lost to the economy of Prince Edward Island. The percentage of people cutting their own fuelwood decreased from 52 in 1984-85 to only 23.4 in 1990-91. The governments of Canada and Prince Edward Island have implemented a series of Forest Resource Development Agreements (FRDAs) starting in 1983. The current 1988-1993 FRDA provides USD 24 million for research and incentives for reforestation and management of Prince Edward Island woodlots. It is expected that 3,800 Prince Edward Island woodlot owners will be participating in a woodlot management program by 1993. Silviculture treatments of hardwood stands include thinning, stand conversion (removal of lowgrade softwoods such as balsam fir in mainly hardwood stands), and shelterwood (strip) cutting, particularly in marginal stands. (9 refs.)
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National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains quantities and values for all seafood products that are reported landed in St. Thomas, St. Croix or St. John, U.S. Virgin Islands. These data...
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Lambs, Luc; Mangion, Perrine; Mougin, Eric; Fromard, François
2016-01-30
The functioning of mangrove forests found on small coralline islands is characterized by limited freshwater inputs. Here, we present data on the water cycling of such systems located on Europa and Juan de Nova Islands, Mozambique Channel. In order to better understand the water cycle and mangrove growth conditions, we have analysed the hydrological and salinity dynamics of the systems by gauge pressure and isotopic tracing (δ18O and δ2H values). Both islands have important seawater intrusion as measured by the water level change and the high salinities in the karstic ponds. Europa Island displays higher salinity stress, with its inner lagoon, but presents a pluri-specific mangrove species formation ranging from shrub to forest stands. No freshwater signal could be detected around the mangrove trees. On Juan de Nova Island, the presence of sand and detrital sediment allows the storage of some amount of rainfall to form a brackish groundwater. The mangrove surface area is very limited with only small mono-specific stands being present in karstic depression. On the drier Europa Island, the salinity of all the water points is equal to or higher than that of the seawater, and on Juan de Nova the groundwater salinity is lower (5 to 20 PSU). This preliminary study shows that the karstic pothole mangroves exist due to the sea connection through the fractured coral and the high tidal dynamics.
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A Novel Unscheduled Islanding Detection Method for Microgrid
Directory of Open Access Journals (Sweden)
Li Hui
2018-01-01
Full Text Available Microgrid with its intelligent and flexible control characteristics conform to the trend of sustainable development of electricity, and when the microgrid in the unplanned island state, the successful detection of the island is a prerequisite, energy storage inverter as the key equipment in the microgrid system, island protection is one of the necessary functions. In this paper, an improved islanding detection method based on active frequency drift and q-axis reactive power perturbation is proposed. The method has the advantages of faster detection speed and minor influence on power quality, which makes the energy storage inverter with better output power quality when it works on grid-connected state, and can be detected the islanding state quickly from grid-connected mode to islanded mode. Finally, the validity and superiority of the improved island detection method are verified by simulation experiments.
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Carracedo, Juan-Carlos; Meco, Joaquín.; Lomoschitz, Alejandro; Antonia Perera, María.; Ballester, Javier; Betancort, Juan-Francisco
2004-10-01
In a recent paper Zöller et al. (2003) present their results of the stratigraphic, sedimentologic, soil mineralogy and IRSL dating of several soil beds filling a basin located near the village of Guatiza, at the eastern flank of the Famara shield, in the island of Lanzarote (Canary Islands). According to these authors, the soils correspond to a desert loess-palaeosol sequence with many coarse alluvial fan deposits, accumulated as scoria cones encircled the open ancient valley extending from SW to NE near Guatiza and their lava flowed to form the Vega de Guatiza endoreic basin. According to these authors, this depression served as a sediment trap from its formation.
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Sagonas, Kostas; Pafilis, Panayiotis; Valakos, Efstratios D.
2015-10-01
Living on islands entails numerous challenges for animals, among which resource scarcity stands out. In order to survive, animals have to optimize energy acquisition. We examined the impact of insularity on digestion comparing a series of physiological and morphological traits of adult males between insular and mainland populations of the Balkan green lizard. Island lizards had longer gastrointestinal tracts and gut passage times and higher digestive efficiencies. The dissection of the hindgut revealed an unexpected finding, the presence of cecal valves that were more frequent in island lizards. Thanks to all above islanders retain food for longer periods and thus maximize energy income and increase the amount of the extracted nutrients. That way, they secure energy income from the limited, in time and quantity, food resources of the islands.
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MARINE BOTTOM COMMUNITIES OF BLOCK ISLAND WATERS
The sea has long been an integral part of Block Island's natural history, beginning when the rising sea surrounded the high spot on a Pleistocene terminal moraine that became Block Island. The southern New England continental shelf, which lies around Block Island, and the Great S...
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International Nuclear Information System (INIS)
MacLeod, G.K.
1986-01-01
The accident at Three Mile Island proved that the Pennsylvania Department of Health lacked the tools to deal with the serious health consequences that occurred during and after this emergency. Despite the relative safety of nuclear power generation, we must be better prepared for the health and medical consequences of serous radiation emergencies. The author reviews the Three Mile Island accident through the eyes of newspaper reporters
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Surficial geology of the sea floor in Long Island Sound offshore of Plum Island, New York
McMullen, K.Y.; Poppe, L.J.; Danforth, W.W.; Blackwood, D.S.; Schaer, J.D.; Ostapenko, A.J.; Glomb, K.A.; Doran, E.F.
2010-01-01
The U.S. Geological Survey (USGS), the Connecticut Department of Environmental Protection, and the National Oceanic and Atmospheric Administration (NOAA) have been working cooperatively to interpret surficial sea-floor geology along the coast of the Northeastern United States. NOAA survey H11445 in eastern Long Island Sound, offshore of Plum Island, New York, covers an area of about 12 square kilometers. Multibeam bathymetry and sidescan-sonar imagery from the survey, as well as sediment and photographic data from 13 stations occupied during a USGS verification cruise are used to delineate sea-floor features and characterize the environment. Bathymetry gradually deepens offshore to over 100 meters in a depression in the northwest part of the study area and reaches 60 meters in Plum Gut, a channel between Plum Island and Orient Point. Sand waves are present on a shoal north of Plum Island and in several smaller areas around the basin. Sand-wave asymmetry indicates that counter-clockwise net sediment transport maintains the shoal. Sand is prevalent where there is low backscatter in the sidescan-sonar imagery. Gravel and boulder areas are submerged lag deposits produced from the Harbor Hill-Orient Point-Fishers Island moraine segment and are found adjacent to the shorelines and just north of Plum Island, where high backscatter is present in the sidescan-sonar imagery.
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From 3D to 4D seismic tomography at El Hierro Island (Canary Islands, Spain)
Garcia-Yeguas, A.; Koulakov, I.; Jakovlev, A.; Ibáñez, J. M.
2012-04-01
In this work we are going to show the advantages of a dynamic tomography 4D, versus a static image 3D related with a volcanic reactivation and eruption at El Hierro island (Canary Islands, Spain). In this process a high number of earthquakes before and during the eruptive processes have been registered. We are going to show a 3D image as an average of the velocity structure and then the characteristics and physical properties on the medium, including the presence or not of magma. This image will be complemented with its evolution along the time, observing its volcanic dynamic and its influence over the medium properties, including its power as an important element on early warnings protocols. After more than forty years of quiet at Canary Islands, since 1971 with Teneguía eruption at La Palma Island, and more than 200 years on El Hierro Island (The last eruption known at El Hierro took place in 1793, volcán de Lomo Negro), on 19th July on 2011 the Spanish seismic national network, administered by IGN (Instituto Geográfico Nacional), detected an increase of local seismic activity below El Hierro island (Canary Islands, Spain). Since this moment an intense swarm took place, with more than 11000 events, until 11th December, with magnitudes (MLg) from 0.2 to 4.4. In this period two eruptive processes have been declared in front of the South coast of El Hierro island, and they have not finished yet. This seismic swarm has allowed carrying out a 3D seismic tomography, using P and S waves traveltimes. It has showed a low velocity from the North to the South. On the other hand, we have performed a 4D seismic tomography, taking the events occurred at different intervals of time. We can observe the evolution of the negative anomaly along the time, from the North to the South, where has taken place La Restinga submarine eruption. 4D seismic tomography is an innovative and powerful tool able to show the evolution in time of a volcanic process.
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Hypersonic drift-tearing magnetic islands in tokamak plasmas
International Nuclear Information System (INIS)
Fitzpatrick, R.; Waelbroeck, F. L.
2007-01-01
A two-fluid theory of long wavelength, hypersonic, drift-tearing magnetic islands in low-collisionality, low-β plasmas possessing relatively weak magnetic shear is developed. The model assumes both slab geometry and cold ions, and neglects electron temperature and equilibrium current gradient effects. The problem is solved in three asymptotically matched regions. The 'inner region' contains the island. However, the island emits electrostatic drift-acoustic waves that propagate into the surrounding 'intermediate region', where they are absorbed by the plasma. Since the waves carry momentum, the inner region exerts a net force on the intermediate region, and vice versa, giving rise to strong velocity shear in the region immediately surrounding the island. The intermediate region is matched to the surrounding 'outer region', in which ideal magnetohydrodynamic holds. Isolated hypersonic islands propagate with a velocity that lies between those of the unperturbed local ion and electron fluids, but is much closer to the latter. The ion polarization current is stabilizing, and increases with increasing island width. Finally, the hypersonic branch of isolated island solutions ceases to exist above a certain critical island width. Hypersonic islands whose widths exceed the critical width are hypothesized to bifurcate to the so-called 'sonic' solution branch
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Directory of Open Access Journals (Sweden)
Y. G. Arsanov
2014-01-01
Full Text Available Aim. Ecological-faunistic investigations of island Chechen are great interest for understanding the law of formation of island biotas and reconstruction of zoogeological history of the Caspian Sea. Faunistic investigations of islands and coastal areas , habitats and others chorologic aspects illuminate the ways of their probable settlement,explains the paradoxes of propagation of some species. Study of relationships with host plants appear the crucial stage of ecological-faunistic investigathions of the weevils.Location. Materials of the work were expeditionary duties of the authors, as well as staff and the students of ecologo-geografical faculty of Dagistan State University and the Institute for Applied Ecology ( Makhachkala from 2009 to 2013 year for the island Chechen.Methods. Charges were made with the help of light traps, soil traps, including trap, enhanced light source .Geografpical coordinates of all locations were recorded using GPS- navigator: T1 - 43°57’58” N 47°38’35” E; T2 - 43°58’17” N 47°42’55”; T3 - 43°59’08” N 47°44’39” E; T4 - 43°57’27” N 47°45’05” E; T5 - 43°58’11” N47°38’46” E.Results. As a result of studies were set the species composition of the faun of the beetle-weevils of the island Chechen, the analyses of the distribution of species by locality; mounted forage plants of the beetles and quantitative distribution of the beetls for families forage plants; conduct the zoogeographical analysis of studied fauna.Main conclusions. The studies on the island of Chechen were collected 187 specimens belonging to 16 species and 14 geniuse; the most common type was Coniatus splendidulus. The food base of the weevil beetles in the island of Chechen are 10 plant families,thelargest number of species focused on Chenopodiаceae, then followed Polygonaceae, Poaceae, Fabaceae. Analysis of fauna habitats of the beetle- weevils of the island Chechen allowed to allocate 7
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Eriksson, S.; Newman, D. L.; Lapenta, G.; Angelopoulos, V.
2014-06-01
We report the first observation consistent with a magnetic reconnection generated magnetic island at a solar wind current sheet that was observed on 10 June 2012 by the two ARTEMIS satellites and the upstream WIND satellite. The evidence consists of a core magnetic field within the island which is formed by enhanced Hall magnetic fields across a solar wind reconnection exhaust. The core field at ARTEMIS displays a local dip coincident with a peak plasma density enhancement and a locally slower exhaust speed which differentiates it from a regular solar wind exhaust crossing. Further indirect evidence of magnetic island formation is presented in the form of a tripolar Hall magnetic field, which is supported by an observed electron velocity shear, and plasma density depletion regions which are in general agreement with multiple reconnection X-line signatures at the same current sheet on the basis of predicted signatures of magnetic islands as generated by a kinetic reconnection simulation for solar wind-like conditions. The combined ARTEMIS and WIND observations of tripolar Hall magnetic fields across the same exhaust and Grad-Shrafranov reconstructions of the magnetic field suggest that an elongated magnetic island was encountered which displayed a 4RE normal width and a 43RE extent along the exhaust between two neighboring X-lines.
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Directory of Open Access Journals (Sweden)
Vroom, P.S.
2012-05-01
Full Text Available The marine benthic algae from Jarvis Island and Kingman Reef were identified from collections obtained from the Whippoorwill Expedition in 1924, the Itasca Expedition in 1935, the U.S. Coast Guard Cutter Taney in 1938, the Smithsonian Institution’s Pacific Ocean Biological Survey Program in 1964 and the U.S. National Oceanic and Atmospheric Administration’s Reef Assessment and Monitoring Program (RAMP in 2000, 2001, 2002, 2004 and 2006. A total of 124 species, representing 8 Cyanobacteria (blue-green algae, 82 Rhodophyta (red algae, 6 Heterokontophyta (brown algae and 28 Chlorophyta (green algae, are reported from both islands. Seventy-nine and 95 species of marine benthic algae are recorded from Jarvis Island and Kingman Reef, respectively. Of the 124 species, 77 species or 62% (4 blue-green algae, 57 red algae, 2 brown algae and 14 green algae have never before been reported from the 11 remote reefs, atolls and low islands comprising the Line Islands in the Central Pacific.
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On guard - Ice patrol out to make sure oil platform is no Titanic
Energy Technology Data Exchange (ETDEWEB)
Harvie, W.
1997-12-01
For offshore oil operations floating icebergs represent a formidable danger. Hibernia is the only one among major offshore sites that faces this particular problem. Accordingly, an elaborate system of iceberg surveillance has been set up. The four-part strategy in place, consisting of surveillance, monitoring, deflection and the iceberg protection features designed into the platform itself, are described in this paper. The essence of the plans is that every iceberg that moves south of the 48th parallel is reported to the St. John`s based Seaborne Information Technologies Ltd., an iceberg information clearinghouse on contract to Hibernia, by passing aircraft, fishing vessels, freighters and others at sea or over the sea. Each occurrence is plotted and monitored. If any of them enters Hibernia`s `tactical zone`, a ring extending 24 nautical miles around the platform, surveillance is intensified and wind and drift patterns are plotted. Deflection becomes a real option when the iceberg enters a ring six nautical miles from the platform. Although icebergs can weigh anywhere up to 5 million tonnes, a slight nudge can cause a degree or two of deflection, enough to send the iceberg sailing past the platform. Smaller icebergs are pushed with prop wash or water cannon aboard the Hibernia supply ships. Larger bergs are lassoed with ropes and dragged a short distance to head them on a different course. The platform itself has a 1.4 metre thick icewall, equipped with 16 teeth to distribute the force on the entire structure should an iceberg actually manage to hit the platform itself. The teeth are designed to withstand a direct hit from a one million tonne iceberg without damage. Statistically, such an event can be expected to occur once every 500 years.
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Shestakov, E. A.; Savrukhin, P. V.
2017-10-01
Experiments in the T-10 tokamak demonstrated possibility of controlling the plasma current during disruption instability using the electron cyclotron resonance heating (ECRH) and the controlled operation of the ohmic current-holding system. Quasistable plasma discharge with repeating sawtooth oscillations can be restored after energy quench using auxiliary ECRH power when PEC / POH > 2-5. The external magnetic field generation system consisted of eight saddle coils that were arranged symmetrically relative to the equatorial plane of the torus outside of the vacuum vessel of the T-10 tokamak to study the possible resonant magnetic field effects on the rotation frequency of magnetic islands. The saddle coils power supply system is based on four thyristor converters with a total power of 300 kW. The power supply control system is based on Siemens S7 controllers. As shown by preliminary experiments, the interaction efficiency of external magnetic fields with plasma depends on the plasma magnetic configuration. Optimal conditions for slowing the rotation of magnetic islands were determined. Additionally, the direction of the error magnetic field in the T-10 tokamak was determined, and the threshold value of the external magnetic field was determined.
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Small Island Visitor Attractions
Directory of Open Access Journals (Sweden)
Haven Allahar
2015-03-01
Full Text Available This article proposes a process framework for developing and managing visitor attractions (VA in small island developing states with Trinidad and Tobago, a two-island state in the Caribbean, as the case study. An extensive literature review was conducted, supported by field observations, individual depth interviews, and small and large focus group meetings. The process framework identified four sets of processes: national policy formulation and legislation; inventory, classification, evaluation, and ranking of VA; general operations management involving project management activities; and site specific activities of development, operations, and maintenance. The value of the framework lies in the fact that no similar framework applicable to small islands was covered in the literature and validation was obtained from a panel of experts and a cross section of tourism stakeholders in Tobago.
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Predictable evolution toward flightlessness in volant island birds.
Wright, Natalie A; Steadman, David W; Witt, Christopher C
2016-04-26
Birds are prolific colonists of islands, where they readily evolve distinct forms. Identifying predictable, directional patterns of evolutionary change in island birds, however, has proved challenging. The "island rule" predicts that island species evolve toward intermediate sizes, but its general applicability to birds is questionable. However, convergent evolution has clearly occurred in the island bird lineages that have undergone transitions to secondary flightlessness, a process involving drastic reduction of the flight muscles and enlargement of the hindlimbs. Here, we investigated whether volant island bird populations tend to change shape in a way that converges subtly on the flightless form. We found that island bird species have evolved smaller flight muscles than their continental relatives. Furthermore, in 366 populations of Caribbean and Pacific birds, smaller flight muscles and longer legs evolved in response to increasing insularity and, strikingly, the scarcity of avian and mammalian predators. On smaller islands with fewer predators, birds exhibited shifts in investment from forelimbs to hindlimbs that were qualitatively similar to anatomical rearrangements observed in flightless birds. These findings suggest that island bird populations tend to evolve on a trajectory toward flightlessness, even if most remain volant. This pattern was consistent across nine families and four orders that vary in lifestyle, foraging behavior, flight style, and body size. These predictable shifts in avian morphology may reduce the physical capacity for escape via flight and diminish the potential for small-island taxa to diversify via dispersal.
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Numerical modeling of atoll island hydrogeology.
Bailey, R T; Jenson, J W; Olsen, A E
2009-01-01
We implemented Ayers and Vachers' (1986) inclusive conceptual model for atoll island aquifers in a comprehensive numerical modeling study to evaluate the response of the fresh water lens to selected controlling climatic and geologic variables. Climatic factors include both constant and time-varying recharge rates, with particular attention paid to the effects of El Niño and the associated drought it brings to the western Pacific. Geologic factors include island width; hydraulic conductivity of the uppermost Holocene-age aquifer, which contains the fresh water lens; the depth to the contact with the underlying, and much more conductive, Pleistocene karst aquifer, which transmits tidal signals to the base of the lens; and the presence or absence of a semiconfining reef flat plate on the ocean side. Sensitivity analyses of steady-steady simulations show that lens thickness is most strongly sensitive to the depth to the Holocene-Pleistocene contact and to the hydraulic conductivity of the Holocene aquifer, respectively. Comparisons between modeling results and published observations of atoll island lens thicknesses suggest a hydraulic conductivity of approximately 50 m/d for leeward islands and approximately 400 m/d for windward islands. Results of transient simulations show that lens thickness fluctuations during average seasonal conditions and El Niño events are quite sensitive to island width, recharge rate, and hydraulic conductivity of the Holocene aquifer. In general, the depletion of the lens during drought conditions is most drastic for small, windward islands. Simulation results suggest that recovery from a 6-month drought requires about 1.5 years.
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Climate Change in the Pacific Islands
Hamnett, Michael P.
Climate change have been a major concern among Pacific Islanders since the late 1990s. During that period, Time Magazine featured a cover story that read: Say Goodbye to the Marshall Islands, Kiribati, and Tuvalu from sea level rise. Since that time, the South Pacific Regional Environment Programme, UN and government agencies and academic researchers have been assessing the impacts of long-term climate change and seasonal to inter-annual climate variability on the Pacific Islands. The consensus is that long-term climate change will result in more extreme weather and tidal events including droughts, floods, tropical cyclones, coastal erosion, and salt water inundation. Extreme weather events already occur in the Pacific Islands and they are patterned. El Niño Southern Oscillation (ENSO) events impact rainfall, tropical cyclone and tidal patterns. In 2000, the first National Assessment of the Consequences of Climate Variability and Change concluded that long-term climate change will result in more El Niño events or a more El Niño like climate every year. The bad news is that will mean more natural disasters. The good news is that El Niño events can be predicted and people can prepare for them. The reallly bad news is that some Pacific Islands are already becoming uninhabitable because of erosion of land or the loss of fresh water from droughts and salt water intrusion. Many of the most vulnerable countries already overseas populations in New Zealand, the US, or larger Pacific Island countries. For some Pacific Islander abandoning their home countries will be their only option.
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Recent rift formation and impact on the structural integrity of the Brunt Ice Shelf, East Antarctica
De Rydt, Jan; Hilmar Gudmundsson, G.; Nagler, Thomas; Wuite, Jan; King, Edward C.
2018-02-01
We report on the recent reactivation of a large rift in the Brunt Ice Shelf, East Antarctica, in December 2012 and the formation of a 50 km long new rift in October 2016. Observations from a suite of ground-based and remote sensing instruments between January 2000 and July 2017 were used to track progress of both rifts in unprecedented detail. Results reveal a steady accelerating trend in their width, in combination with alternating episodes of fast ( > 600 m day-1) and slow propagation of the rift tip, controlled by the heterogeneous structure of the ice shelf. A numerical ice flow model and a simple propagation algorithm based on the stress distribution in the ice shelf were successfully used to hindcast the observed trajectories and to simulate future rift progression under different assumptions. Results show a high likelihood of ice loss at the McDonald Ice Rumples, the only pinning point of the ice shelf. The nascent iceberg calving and associated reduction in pinning of the Brunt Ice Shelf may provide a uniquely monitored natural experiment of ice shelf variability and provoke a deeper understanding of similar processes elsewhere in Antarctica.
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Professional operation and management of nuclear island installation
International Nuclear Information System (INIS)
Ma Limin
2011-01-01
As an important part of nuclear power plant construction, nuclear island installation mainly involves main equipment installation, pipeline installation, associated procedure examination and other important tasks. However, due to the nuclear island installation management changing from single project to multi-projects, the problems such as professional management of nuclear island installation and the lack of technical staff become more and more prominent and become one of the key restricts to the work of nuclear island installation. Based on analysis of the single project, single-base nuclear island installation management and practice, combined with the current situation that multi-project and multi-base construction of nuclear power are carrying out at the same time, this paper proposes a new management model of nuclear island installation. (author)
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Phytoseiid mites of the Canary Islands (Acari, Phytoseiidae. II. Tenerife and La Gomera Islands
Directory of Open Access Journals (Sweden)
Ferragut, F.
2007-12-01
Full Text Available Phytoseiid mites (Acari, Phytoseiidae inhabiting plants in natural ecosystems from Tenerife and La Gomera islands (Canary Islands have been studied. Surveys were conducted from 1997 to 2002. Eleven species were collected, one of them being reported for the first time from the Canary Islands and six of them reported for the first time from Tenerife and La Gomera islands. Euseius machadoi n. sp. collected from woody plants in the Canarian laurisilva is proposed as a new species.
En muestreos realizados desde 1997 hasta 2002 se ha estudiado la fauna de ácaros fitoseidos (Acari, Phytoseiidae asociada a plantas de ecosistemas naturales de las islas de Tenerife y La Gomera (Islas Canarias. Se han recolectado un total de 11 especies, siendo una de ellas citada por vez primera en las islas Canarias y seis de ellas citadas por primera vez en las islas de Tenerife y La Gomera. Euseius machadoi n. sp., recolectado en plantas leñosas de la laurisilva canaria, se propone como una nueva especie. -
Decolonizing through integration: Australia's off-shore island territories
Directory of Open Access Journals (Sweden)
Roger Wettenhall
2016-11-01
Full Text Available Australia’s three small off-shore island territories – Norfolk Island in the Pacific Ocean and Christmas Island and the Cocos (Keeling Islands Group in the Indian Ocean – can be seen as monuments to 19th century British-style colonization, though their early paths to development took very different courses. Their transition to the status of external territories of the Australian Commonwealth in the 20th century – early in the case of Norfolk and later in the cases of Christmas and Cocos – put them on a common path in which serious tensions emerged between local populations which sought autonomous governance and the Commonwealth government which wanted to impose governmental systems similar to those applying to mainstream Australians. This article explores the issues involved, and seeks to relate the governmental history of the three island territories to the exploration of island jurisdictions developed in island studies research.
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International Nuclear Information System (INIS)
Nikolaeva, O.V.
1997-01-01
Principles of the formation o data base for 339 samples of oceanic island arc (OIA) igneous rocks of the Earth available in literature are described as well as of the formation of fresh rock sample, characteristics of this sample, and K-U-Th-systematics of the fresh igneous rocks of Earth OIA. Results of comparison of the Venus measured rocks and Earth OIA rocks by K, U, Th
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NaCl islands decorated with 2D or 3D 3,4,9,10-perylene-tetracarboxylic-dianhydride nanostructures
Sun, Xiaonan; Silly, Fabien
2010-01-01
The formation of PTCDA (3,4,9,10-perylene-tetracarboxylic-dianhydride) nanostrutures on Au(1 1 1)-(22 x root 3) covered with NaCl islands has been studied using scanning tunneling microscopy (STM). Atomically resolved STM images show that NaCl grows as (1 0 0)-terminated layers on Au(1 1 1)-(22 x
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International Nuclear Information System (INIS)
Claude-Ivana, Ch.
1997-02-01
The development of a new precise analytical technique for measuring radioactive disequilibria by TIMS has enabled to put constraints on both the extend and time scale of incompatible element fractionation during magma formation in oceanic islands. Three different settings have been studied: the Grande Comore volcanoes (Comores archipelago), Tenerife and Lanzarote volcanism (Canary islands) and four islands within the Azores: Sao Miguel, Terceira, Pico and Faial islands. The Comores and Canaries archipelagoes are both lying on an old thick oceanic lithosphere. The detailed case in Grande Comore shows evidence for a process of interaction of the Comore plume with the underlying lithosphere. In the Canaries, the lithosphere also contributes to lava formation either during the differentiation (in Tenerife) or during mantle melting (in Lanzarote). Within the Azores, U-series measurements reveal large geochemical and isotopic variations between the different islands that we interpret as reflecting heterogeneities in the Azore plume. In particular, the U-Th fractionation in Sao Miguel volcanics is though to result from melting of an hydrous sediment-bearing mantle. The magma transit times have been found to be very short (1000 yr) in all the basaltic series. This very rapid migration of the melts is an evidence for the absence of large magma chamber and for processes of fracturing during melt transports. However, this model does not apply in the case of the very evolved volcanic series in Tenerife island (Canaries) where transit times of c.a. 100000 yr indicate the presence of a large magmatic reservoir. (author)
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Stock, Jan H.
1988-01-01
Pseudoniphargus was known from inland stygohabitats in the Iberian peninsula, the Azores, Madeira, N.W. Africa, and Bermuda, but not from the Canary Islands. Systematic sampling in six of the seven larger islands of the latter archipelago has revealed the presence of the genus in Tenerife (4
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Reconstructed Marine Fisheries Catches at a Remote Island Group: Pitcairn Islands (1950–2014
Directory of Open Access Journals (Sweden)
Amy R. Coghlan
2017-09-01
Full Text Available The remote Pitcairn Island Group in the South Pacific was designated one of the world's largest marine reserves in 2016, encompassing some of the few remaining near-pristine areas within EEZ boundaries. Pitcairn's domestic fisheries are small-scale, and consist mainly of subsistence (non-commercial and limited artisanal (commercial catches. There is no locally-based industrial (large-scale commercial fishery and the level of foreign industrial activity in recent times has been minimal, due in part to the low biomass of commercially valuable species, along with economic constraints of the EEZ's geographic isolation. Using a catch reconstruction method we estimated the total domestic marine catches for the Pitcairn Islands from 1950 to 2014. We show that overall the Pitcairn Islands' small-scale fisheries catches were almost 2.5 times higher than the data reported by the Food and Agriculture Organization (FAO of the United Nations on behalf of the Pitcairn Islands, however, this primarily reflects discrepancies prior to the 1980s. Overall, catches for the subsistence and artisanal sectors started with around 12 t·year−1 in 1950, but declined to 4 t·year−1 by 2014. Domestic reconstructed subsistence catch levels were entirely driven by changes in the human population on the island, with reconstructed artisanal catches only occurring in recent years (2000 onwards. Industrial fishing is entirely executed by foreign vessels, this catch is considerably variable throughout the years and ceases entirely in 2006. The implementation of one of the world's largest marine reserves surrounding the offshore waters of Pitcairn Island has been specifically designed not to affect the rates of subsistence and artisanal fishing conducted by the resident population. Although there is no industrial fishing in the Pitcairn EEZ at present, climate change is predicted to influence the routes of migrating commercially-targeted species, potentially altering fishing
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2010-07-01
... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pacific Ocean off Orote Point, Apra Harbor, Island of Guam, Marianas Islands; small arms firing range. 334.1420 Section 334.1420... AND RESTRICTED AREA REGULATIONS § 334.1420 Pacific Ocean off Orote Point, Apra Harbor, Island of Guam...
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Energy Technology Data Exchange (ETDEWEB)
Cao, Jinjia; Gong, Xueyu, E-mail: gongxueyu-usc@163.com; Xiang, Dong; Huang, Qianhong [School of Nuclear Science and Technology, University of South China, Hengyang 421001 (China); Yu, Jun [School of Mathematics and Physics, University of South China, Hengyang 421001 (China)
2016-08-15
The structure of the drift-island surface of passing fast ions (PFIs) is investigated in the presence of the resonant interaction with a magnetic island. Two overlapping regions of the drift-island surface and the magnetic island surface are found, one corresponding to local overlapping region and the other to non-local one. Here, the word “nonlocal” denotes that the resonances in the core plasma can have effects on the PFIs near the plasma boundary, while the “local” represents that the PFIs just near the resonant location are influenced. The nonlocal overlapping constructs a transport path along which the PFIs can become losses. There are three kinds of drift-island surfaces to join in forming the transport paths. A pitch angle region, which is called pitch angle gap, is found near the plasma boundary, where the drift-island surface cannot be formed and few PFIs are lost. The pitch-angle selective features of PFI losses are obtained by analyzing the three kinds of drift-island surfaces. The coupling between the crowd drift island surfaces and the collision can induce the prompt losses of PFIs and rapidly slowing down of PFI energy. The time of the prompt losses and the slowing down rate are calculated. Qualitatively, the theoretical results are in well agreement with the experimental observations in ASDEX Upgrade [M. García-Muñoz et al., Nucl. Fusion 47, L10 (2007)].
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Plasmonic Optical Fiber Sensor Based on Double Step Growth of Gold Nano-Islands.
de Almeida, José M M M; Vasconcelos, Helena; Jorge, Pedro A S; Coelho, Luis
2018-04-20
It is presented the fabrication and characterization of optical fiber sensors for refractive index measurement based on localized surface plasmon resonance (LSPR) with gold nano-islands obtained by single and by repeated thermal dewetting of gold thin films. Thin films of gold deposited on silica (SiO₂) substrates and produced by different experimental conditions were analyzed by Scanning Electron Microscope/Dispersive X-ray Spectroscopy (SEM/EDS) and optical means, allowing identifying and characterizing the formation of nano-islands. The wavelength shift sensitivity to the surrounding refractive index of sensors produced by single and by repeated dewetting is compared. While for the single step dewetting, a wavelength shift sensitivity of ~60 nm/RIU was calculated, for the repeated dewetting, a value of ~186 nm/RIU was obtained, an increase of more than three times. It is expected that through changing the fabrication parameters and using other fiber sensor geometries, higher sensitivities may be achieved, allowing, in addition, for the possibility of tuning the plasmonic frequency.
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Plasmonic Optical Fiber Sensor Based on Double Step Growth of Gold Nano-Islands
Vasconcelos, Helena
2018-01-01
It is presented the fabrication and characterization of optical fiber sensors for refractive index measurement based on localized surface plasmon resonance (LSPR) with gold nano-islands obtained by single and by repeated thermal dewetting of gold thin films. Thin films of gold deposited on silica (SiO2) substrates and produced by different experimental conditions were analyzed by Scanning Electron Microscope/Dispersive X-ray Spectroscopy (SEM/EDS) and optical means, allowing identifying and characterizing the formation of nano-islands. The wavelength shift sensitivity to the surrounding refractive index of sensors produced by single and by repeated dewetting is compared. While for the single step dewetting, a wavelength shift sensitivity of ~60 nm/RIU was calculated, for the repeated dewetting, a value of ~186 nm/RIU was obtained, an increase of more than three times. It is expected that through changing the fabrication parameters and using other fiber sensor geometries, higher sensitivities may be achieved, allowing, in addition, for the possibility of tuning the plasmonic frequency. PMID:29677108
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The diffuse chemosensory system: exploring the iceberg toward the definition of functional roles.
Sbarbati, Andrea; Bramanti, Placido; Benati, Donatella; Merigo, Flavia
2010-05-01
The diffuse chemosensory system (DCS) is an anatomical structure composed of solitary chemosensory cells (SCCs, also called solitary chemoreceptor cells), which have analogies with taste cells but are not aggregated in buds. The concept of DCS has been advanced, after the discovery that cells similar to gustatory elements are present in several organs. The elements forming the DCS share common morphological and biochemical characteristics with the taste cells located in taste buds of the oro-pharyngeal cavity but they are localized in internal organs. In particular, they may express molecules of the chemoreceptorial cascade (e.g. trans-membrane taste receptors, the G-protein alpha-gustducin, PLCbeta2, TRPM5). This article will focus on the mammalian DCS in apparatuses of endodermic origin (i.e. digestive and respiratory systems), which is composed of an enormous number of sensory elements and presents a multiplicity of morphological aspects. Recent research has provided an adequate description of these elements, but the functional role for the DCS in these apparatuses is unknown. The initial findings led to the definition of a DCS structured like an iceberg, with a mysterious "submerged" portion localized in the distal part of endodermic apparatuses. Recent work has focussed on the discovery of this submerged portion, which now appears less puzzling. However, the functional roles of the different cytotypes belonging to the DCS are not well known. Recent studies linked chemosensation of the intraluminal content to local control of absorptive and secretory (exocrine and endocrine) processes. Control of the microbial population and detection of irritants seem to be other possible functions of the DCS. In the light of these new findings, the DCS might be thought to be involved in a wide range of diseases of both the respiratory (e.g. asthma, chronic obstructive pulmonary disease, cystic fibrosis) and digestive apparatuses (absorptive or secretive diseases, dysmicrobism
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Non-Gaussianity in island cosmology
International Nuclear Information System (INIS)
Piao Yunsong
2009-01-01
In this paper we fully calculate the non-Gaussianity of primordial curvature perturbation of the island universe by using the second order perturbation equation. We find that for the spectral index n s ≅0.96, which is favored by current observations, the non-Gaussianity level f NL seen in an island will generally lie between 30 and 60, which may be tested by the coming observations. In the landscape, the island universe is one of anthropically acceptable cosmological histories. Thus the results obtained in some sense mean the coming observations, especially the measurement of non-Gaussianity, will be significant to clarify how our position in the landscape is populated.
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The CpG island searcher: a new WWW resource.
Takai, Daiya; Jones, Peter A
2003-01-01
Clusters of CpG dinucleotides in GC rich regions of the genome called "CpG islands" frequently occur in the 5' ends of genes. Methylation of CpG islands plays a role in transcriptional silencing in higher organisms in certain situations. We have established a CpG-island-extraction algorithm, which we previously developed [Takai and Jones, 2002], on a web site which has a simple user interface to identify CpG islands from submitted sequences of up to 50kb. The web site determines the locations of CpG islands using parameters (lower limit of %GC, ObsCpG/ExpCpG, length) set by the user, to display the value of parameters on each CpG island, and provides a graphical map of CpG dinucleotide distribution and borders of CpG islands. A command-line version of the CpG islands searcher has also been developed for larger sequences. The CpG Island Searcher was applied to the latest sequence and mapping information of human chromosomes 20, 21 and 22, and a total of 2345 CpG islands were extracted and 534 (23%) of them contained first coding exons and 650 (28%) contained other exons. The CpG Island Searcher is available on the World Wide Web at http://www.cpgislands.com or http://www.uscnorris.com/cpgislands/cpg.cgi.
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Mandal, S.; Satpati, L. N.; Choudhury, B. U.; Sadhu, S.
2018-04-01
The present study assessed climate change vulnerability in agricultural sector of low-lying Sagar Island of Bay of Bengal. Vulnerability indices were estimated using spatially aggregated biophysical and socio-economic parameters by applying principal component analysis and equal weight method. The similarities and differences of outputs of these two methods were analysed across the island. From the integration of outputs and based on the severity of vulnerability, explicit vulnerable zones were demarcated spatially. Results revealed that life subsistence agriculture in 11.8% geographical area (2829 ha) of the island along the western coast falls under very high vulnerable zone (VHVZ VI of 84-99%) to climate change. Comparatively higher values of exposure (0.53 ± 0.26) and sensitivity (0.78 ± 0.14) subindices affirmed that the VHV zone is highly exposed to climate stressor with very low adaptive capacity (ADI= 0.24 ± 0.16) to combat vulnerability to climate change. Hence, food security for a population of >22 thousands comprising >3.7 thousand agrarian households are highly exposed to climate change. Another 17% area comprising 17.5% population covering 20% villages in north-western and eastern parts of the island also falls under high vulnerable (VI= 61%-77%) zone. Findings revealed large spatial heterogeneity in the degree of vulnerability across the island and thus, demands devising area specific planning (adaptation and mitigation strategies) to address the climate change impact implications both at macro and micro levels.
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Diet patterns of island foxes on San Nicolas Island relative to feral cat removal
Cypher, Brian L.; Kelly, Erica C.; Ferrara, Francesca J.; Drost, Charles A.; Westall, Tory L.; Hudgens, Brian
2017-01-01
Island foxes (Urocyon littoralis) are a species of conservation concern that occur on six of the Channel Islands off the coast of southern California. We analysed island fox diet on San Nicolas Island during 2006–12 to assess the influence of the removal of feral cats (Felis catus) on the food use by foxes. Our objective was to determine whether fox diet patterns shifted in response to the cat removal conducted during 2009–10, thus indicating that cats were competing with foxes for food items. We also examined the influence of annual precipitation patterns and fox abundance on fox diet. On the basis of an analysis of 1975 fox scats, use of vertebrate prey – deer mice (Peromyscus maniculatus), birds, and lizards – increased significantly during and after the complete removal of cats (n = 66) from the island. Deer mouse abundance increased markedly during and after cat removal and use of mice by foxes was significantly related to mouse abundance. The increase in mice and shift in item use by the foxes was consistent with a reduction in exploitative competition associated with the cat removal. However, fox abundance declined markedly coincident with the removal of cats and deer mouse abundance was negatively related to fox numbers. Also, annual precipitation increased markedly during and after cat removal and deer mouse abundance closely tracked precipitation. Thus, our results indicate that other confounding factors, particularly precipitation, may have had a greater influence on fox diet patterns.