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Sample records for ridge melt production

  1. Production, pathways and budgets of melts in mid-ocean ridges: An enthalpy based thermo-mechanical model

    Science.gov (United States)

    Mandal, Nibir; Sarkar, Shamik; Baruah, Amiya; Dutta, Urmi

    2018-04-01

    Using an enthalpy based thermo-mechanical model we provide a theoretical evaluation of melt production beneath mid-ocean ridges (MORs), and demonstrate how the melts subsequently develop their pathways to sustain the major ridge processes. Our model employs a Darcy idealization of the two-phase (solid-melt) system, accounting enthalpy (ΔH) as a function of temperature dependent liquid fraction (ϕ). Random thermal perturbations imposed in this model set in local convection that drive melts to flow through porosity controlled pathways with a typical mushroom-like 3D structure. We present across- and along-MOR axis model profiles to show the mode of occurrence of melt-rich zones within mushy regions, connected to deeper sources by single or multiple feeders. The upwelling of melts experiences two synchronous processes: 1) solidification-accretion, and 2) eruption, retaining a large melt fraction in the framework of mantle dynamics. Using a bifurcation analysis we determine the threshold condition for melt eruption, and estimate the potential volumes of eruptible melts (∼3.7 × 106 m3/yr) and sub-crustal solidified masses (∼1-8.8 × 106 m3/yr) on an axis length of 500 km. The solidification process far dominates over the eruption process in the initial phase, but declines rapidly on a time scale (t) of 1 Myr. Consequently, the eruption rate takes over the solidification rate, but attains nearly a steady value as t > 1.5 Myr. We finally present a melt budget, where a maximum of ∼5% of the total upwelling melt volume is available for eruption, whereas ∼19% for deeper level solidification; the rest continue to participate in the sub-crustal processes.

  2. Migrating Toward Fully 4-D Geodynamical Models of Asthenospheric Circulation and Melt Production at Mid-Ocean Ridges

    Science.gov (United States)

    van Dam, L.; Kincaid, C. R.; Pockalny, R. A.; Sylvia, R. T.; Hall, P. S.

    2017-12-01

    Lateral migration of mid-ocean ridge spreading centers is a well-documented phenomenon leading to asymmetric melt production and the surficial expressions thereof. This form of plate motion has been difficult to incorporate into both numerical and analogue geodynamical models, and consequently, current estimates of time-dependent flow, material transport, and melting in the mantle beneath ridges are lacking. To address this, we have designed and built an innovative research apparatus that allows for precise and repeatable simulations of mid-ocean ridge spreading and migration. Three pairs of counter-rotating belts with adjustable lateral orientations are scaled to simulate spreading at, and flow beneath, three 600km wide ridge segments with up to 300km transform offsets. This apparatus is attached to a drive system that allows us to test a full range of axis-parallel to axis-normal migration directions, and is suspended above a reservoir of viscous glucose syrup, a scaled analogue for the upper mantle, and neutrally buoyant tracers. We image plate-driven flow in the syrup with high-resolution digital cameras and use particle image velocimetry methods to obtain information about transport pathlines and flow-induced anisotropy. Suites of experiments are run with and without ridge migration to determine the overall significance of migration on spatial and temporal characteristics of shallow mantle flow. Our experiments cover an expansive parameter space by including various spreading rates, migration speeds and directions, degrees of spreading asymmetry, transform-offset lengths, and upper mantle viscosity conditions. Preliminary results highlight the importance of modeling migratory plate forces. Mantle material exhibits a significant degree of lateral transport, particularly between ridge segments and towards the melt triangle. Magma supply to the melting region is highly complex; parcels of material do not necessarily move along fixed streamlines, rather, they can

  3. Petrological systematics of mid-ocean ridge basalts: Constraints on melt generation beneath ocean ridges

    Science.gov (United States)

    Langmuir, Charles H.; Klein, Emily M.; Plank, Terry

    Mid-ocean ridge basalts (MORB) are a consequence of pressure-release melting beneath ocean ridges, and contain much information concerning melt formation, melt migration and heterogeneity within the upper mantle. MORB major element chemical systematics can be divided into global and local aspects, once they have been corrected for low pressure fractionation and interlaboratory biases. Regional average compositions for ridges unaffected by hot spots ("normal" ridges) can be used to define the global correlations among normalized Na2O, FeO, TiO2 and SiO2 contents, CaO/Al2O3 ratios, axial depth and crustal thickness. Back-arc basins show similar correlations, but are offset to lower FeO and TiO2 contents. Some hot spots, such as the Azores and Galapagos, disrupt the systematics of nearby ridges and have the opposite relationships between FeO, Na2O and depth over distances of 1000 km. Local variations in basalt chemistry from slow- and fast-spreading ridges are distinct from one another. On slow-spreading ridges, correlations among the elements cross the global vector of variability at a high angle. On the fast-spreading East Pacific Rise (EPR), correlations among the elements are distinct from both global and slow-spreading compositional vectors, and involve two components of variation. Spreading rate does not control the global correlations, but influences the standard deviations of axial depth, crustal thickness, and MgO contents of basalts. Global correlations are not found in very incompatible trace elements, even for samples far from hot spots. Moderately compatible trace elements for normal ridges, however, correlate with the major elements. Trace element systematics are significantly different for the EPR and the mid-Atlantic Ridge (MAR). Normal portions of the MAR are very depleted in REE, with little variability; hot spots cause large long wavelength variations in REE abundances. Normal EPR basalts are significantly more enriched than MAR basalts from normal

  4. The Effects of Ridge Axis Width on Mantle Melting at Mid-Ocean Ridges

    Science.gov (United States)

    Montesi, L.; Magni, V.; Gaina, C.

    2017-12-01

    Mantle upwelling in response to plate divergence produces melt at mid-ocean ridges. Melt starts when the solidus is crossed and stops when conductive cooling overcomes heat advection associated with the upwelling. Most mid-ocean ridge models assume that divergence takes place only in a narrow zone that defines the ridge axis, resulting in a single upwelling. However, more complex patterns of divergence are occasionally observed. The rift axis can be 20 km wide at ultraslow spreading center. Overlapping spreading center contain two parallel axes. Rifting in backarc basins is sometimes organized as a series of parallel spreading centers. Distributing plate divergence over several rifts reduces the intensity of upwelling and limits melting. Can this have a significant effect on the expected crustal thickness and on the mode of melt delivery at the seafloor? We address this question by modeling mantle flow and melting underneath two spreading centers separated by a rigid block. We adopt a non-linear rheology that includes dislocation creep, diffusion creep and yielding and include hydrothermal cooling by enhancing thermal conductivity where yielding takes place. The crustal thickness decreases if the rifts are separated by 30 km or more but only if the half spreading rate is between 1 and 2 cm/yr. At melting depth, a single upwelling remains the norm until the separation of the rifts exceeds a critical value ranging from 15 km in the fastest ridges to more than 50 km at ultraslow spreading centers. The stability of the central upwelling is due to hydrothermal cooling, which prevents hot mantle from reaching the surface at each spreading center. When hydrothermal cooling is suppressed, or the spreading centers are sufficiently separated, the rigid block becomes extremely cold and separates two distinct, highly asymmetric upwellings that may focus melt beyond the spreading center. In that case, melt delivery might drive further and further the divergence centers, whereas

  5. Mantle melting and melt refertilization beneath the Southwest Indian Ridge: Mineral composition of abyssal peridotites

    Science.gov (United States)

    Chen, Ling; Zhu, Jihao; Chu, Fengyou; Dong, Yan-hui; Liu, Jiqiang; Li, Zhenggang; Zhu, Zhimin; Tang, Limei

    2017-04-01

    As one of the slowest spreading ridges of the global ocean ridge system, the Southwest Indian Ridge (SWIR) is characterized by discontinued magmatism. The 53°E segment between the Gallieni fracture zone (FZ) (52°20'E) and the Gazelle FZ (53°30'E) is a typical amagmatic segment (crustal thickness 1cm) Opx, and Mg-rich mineral compositions akin to harzburgite xenoliths that sample old continental lithospheric mantle (Kelemen et al., 1998). Melt refertilization model shows that Group 2 peridotites were affected by an enriched low-degree partial melt from the garnet stability field. These results indicate that depleted mantle which experiences ancient melting event are more sensitive to melt refertilization, thus may reduce the melt flux, leading to extremely thin crust at 53°E segment. This research was granted by the National Basic Research Programme of China (973 programme) (grant No. 2013CB429705) and the Fundamental Research Funds of Second Institute of Oceanography, State Oceanic Administration (JG1603, SZ1507). References: Johnson K T M, Dick H J B, Shimizu N. Melting in the oceanic upper mantle: An ion microprobe study of diopsides in abyssal peridotites[J]. Journal of Geophysical Research, 1990, 95(B3):2661-2678. Kelemen P B, Hart S R, Bernstein S. Silica enrichment in the continental upper mantle via melt/rock reaction[J]. Earth & Planetary Science Letters, 1998, 164(1-2):387-406. Zhou H, Dick H J. Thin crust as evidence for depleted mantle supporting the Marion Rise.[J]. Nature, 2013, 494(7436):195-200.

  6. 230Th-238U disequilibrium and the melting processes beneath ridge axes

    International Nuclear Information System (INIS)

    McKenzie, D.

    1985-01-01

    The activity ratio ( 230 Th/ 238 U) is calculated for a simple model of melting, for which the melt fraction in chemical and radioactive equilibrium with the solid residium remains constant as melting proceeds. The activity ratio in the melt is only significantly different from unity if the melting is slow compared with the half-life of 230 Th and if the melt fraction present at any time does not exceed a few percent. The observation that ( 230 Th/ 238 U) is about 1.25 for many ocean ridge basalts is therefore most easily explained if the melt fraction in the source region is less than 2% and if the melting occurs in a broad region more than 100 km wide beneath the ridge axis. These results are compatible with other geophysical observations. Measurements of ( 226 Ra/ 238 U) might provide useful constraints on the time required to reach chemical equilibrium between the melt and the matrix. (orig.)

  7. A 2D double-porosity model for melting and melt migration beneath mid-oceanic ridges

    Science.gov (United States)

    Liu, B.; Liang, Y.; Parmentier, E.

    2017-12-01

    Several lines of evidence suggest that the melting and melt extraction region of the MORB mantle is heterogeneous consisting of an interconnected network of high permeability dunite channels in a low porosity harzburgite or lherzolite matrix. In principle, one can include channel formation into the tectonic-scale geodynamic models by solving conservation equations for a chemically reactive and viscously deformable porous medium. Such an approach eventually runs into computational limitations such as resolving fractal-like channels that have a spectrum of width. To better understand first order features of melting and melt-rock interaction beneath MOR, we have formulated a 2D double porosity model in which we treat the triangular melting region as two overlapping continua occupied by the low-porosity matrix and interconnected high-porosity channels. We use melt productivity derived from a thermodynamic model and melt suction rate to close our problem. We use a high-order accurate numerical method to solve the conservation equations in 2D for porosity, solid and melt velocities and concentrations of chemical tracers in the melting region. We carry out numerical simulations to systematically study effects of matrix-to-channel melt suction and spatially distributed channels on the distributions of porosity and trace element and isotopic ratios in the melting region. For near fractional melting with 10 vol% channel in the melting region, the flow field of the matrix melt follows closely to that of the solid because the small porosity (exchange between the melt and the solid. The smearing effect can be approximated by dispersion coefficient. For slowly diffusing trace elements (e.g., LREE and HFSE), the melt migration induced dispersion can be as effective as thermal diffusion. Therefore, sub-kilometer scale heterogeneities of Nd and Hf isotopes are significantly damped or homogenized in the melting region.

  8. Grain-Size Dynamics Beneath Mid-Ocean Ridges: Implications for Permeability and Melt Extraction

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    Turner, A. J.; Katz, R. F.; Behn, M. D.

    2014-12-01

    The permeability structure of the sub-ridge mantle plays an important role in how melt is focused and extracted at mid-ocean ridges. Permeability is controlled by porosity and the grain size of the solid mantle matrix, which is in turn controlled by the deformation conditions. To date, models of grain size evolution and mantle deformation have not been coupled to determine the influence of spatial variations in grain-size on the permeability structure at mid-ocean ridges. Rather, current models typically assume a constant grain size for the whole domain [1]. Here, we use 2-D numerical models to evaluate the influence of grain-size variability on the permeability structure beneath a mid-ocean ridge and use these results to speculate on the consequences for melt focusing and extraction. We construct a two-dimensional, single phase model for the steady-state grain size beneath a mid-ocean ridge. The model employs a composite rheology of diffusion creep, dislocation creep, dislocation accommodated grain boundary sliding, and a brittle stress limiter. Grain size is calculated using the "wattmeter" model of Austin and Evans [2]. We investigate the sensitivity of the model to global variations in grain growth exponent, potential temperature, spreading-rate, and grain boundary sliding parameters [3,4]. Our model predicts that permeability varies by two orders of magnitude due to the spatial variability of grain size within the expected melt region of a mid-ocean ridge. The predicted permeability structure suggests grain size may promote focusing of melt towards the ridge axis. Furthermore, the calculated grain size structure should focus melt from a greater depth than models that exclude grain-size variability. Future work will involve evaluating this hypothesis by implementing grain-size dynamics within a two-phase mid-ocean ridge model. The developments of such a model will be discussed. References: [1] R. F. Katz, Journal of Petrology, volume 49, issue 12, page 2099

  9. Extreme incompatibility of helium during mantle melting: Evidence from undegassed mid-ocean ridge basalts

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    Graham, David W.; Michael, Peter J.; Shea, Thomas

    2016-11-01

    We report total helium concentrations (vesicles + glass) for a suite of thirteen ultradepleted mid-ocean ridge basalts (UD-MORBs) that were previously studied for volatile contents (CO2, H2O) plus major and trace elements. The selected basalts are undersaturated in CO2 + H2O at their depths of eruption and represent rare cases of undegassed MORBs. Sample localities from the Atlantic (2), Indian (1) and Pacific (7) Oceans collectively show excellent linear correlations (r2 = 0.75- 0.92) between the concentrations of helium and the highly incompatible elements C, K, Rb, Ba, Nb, Th and U. Three basalts from Gakkel Ridge in the Arctic were also studied but show anomalous behavior marked by excess lithophile trace element abundances. In the Atlantic-Pacific-Indian suite, incompatible element concentrations vary by factors of 3-4.3, while helium concentration varies by a factor of 13. The strong correlations between the concentrations of helium and incompatible elements are explained by helium behavior as the most incompatible element during mantle melting. Partial melting of an ultradepleted mantle source, formed as a residue of earlier melt extraction, accounts for the observed concentrations. The earlier melting event involved removal of a small degree melt (∼1%) at low but non-zero porosity (0.01-0.5%), leading to a small amount of melt retention that strongly leveraged the incompatible element budget of the ultradepleted mantle source. Equilibrium melting models that produce the range of trace element and helium concentrations from this source require a bulk solid/melt distribution coefficient for helium that is lower than that for other incompatible elements by about a factor of ten. Alternatively, the bulk solid/melt distribution coefficient for helium could be similar to or even larger than that for other incompatible elements, but the much larger diffusivity of helium in peridotite leads to its more effective incompatibility and efficient extraction from a

  10. Dacite petrogenesis on mid-ocean ridges: Evidence for oceanic crustal melting and assimilation

    Science.gov (United States)

    Wanless, V.D.; Perfit, M.R.; Ridley, W.I.; Klein, E.

    2010-01-01

    Whereas the majority of eruptions at oceanic spreading centers produce lavas with relatively homogeneous mid-ocean ridge basalt (MORB) compositions, the formation of tholeiitic andesites and dacites at mid-ocean ridges (MORs) is a petrological enigma. Eruptions of MOR high-silica lavas are typically associated with ridge discontinuities and have produced regionally significant volumes of lava. Andesites and dacites have been observed and sampled at several locations along the global MOR system; these include propagating ridge tips at ridge-transform intersections on the Juan de Fuca Ridge and eastern Gal??pagos spreading center, and at the 9??N overlapping spreading center on the East Pacific Rise. Despite the formation of these lavas at various ridges, MOR dacites show remarkably similar major element trends and incompatible trace element enrichments, suggesting that similar processes are controlling their chemistry. Although most geochemical variability in MOR basalts is consistent with low-pressure fractional crystallization of various mantle-derived parental melts, our geochemical data for MOR dacitic glasses suggest that contamination from a seawater-altered component is important in their petrogenesis. MOR dacites are characterized by elevated U, Th, Zr, and Hf, low Nb and Ta concentrations relative to rare earth elements (REE), and Al2O3, K2O, and Cl concentrations that are higher than expected from low-pressure fractional crystallization alone. Petrological modeling of MOR dacites suggests that partial melting and assimilation are both integral to their petrogenesis. Extensive fractional crystallization of a MORB parent combined with partial melting and assimilation of amphibole-bearing altered crust produces a magma with a geochemical signature similar to a MOR dacite. This supports the hypothesis that crustal assimilation is an important process in the formation of highly evolved MOR lavas and may be significant in the generation of evolved MORB in

  11. Using bathymetry and reflective seismic profiles to tests a suspected link between melt flux and cumulative fault heave at mid-ocean ridges

    Science.gov (United States)

    Haughton, G.; Murton, B. J.; Le Bas, T.; Henstock, T.

    2017-12-01

    The interplay between magma supply and spreading rate is believed to play a major role in determining large scale seafloor morphology. Here we use bathymetry to test this relationship in areas with similar spreading rates and differing magma supplies. By using open source bathymetry data we have developed a repeatable, automated method for categorising seafloor cumulative fault heave and then attempt to identify the controlling variables. We measure the total apparent fault heave along axis and off-axis at 29°N and 60°N on the Mid-Atlantic Ridge then compare this to proxies for deformation and magma supply. Two approaches are adopted for identifying faults: one using bathymetry and the other spreading-parallel seismic reflection data. The first re-examines the orthogonally spreading Broken Spur segment (26°N) spreading at 23 mm yr-1 (full rate). The other examines the Reykjanes Ridge (60°N) spreading obliquely at 21 mm yr-1 (full rate), which may be influenced by the Icelandic hotspot. Each have contrasting residual depth and structure, with the former being typical of slow spreading ridges, with marked axial valleys, whereas the latter is more typical of fast spreading ridge morphology, with smooth axial rise. We find that high total heave (indicating high tectonic spreading) on the Broken Spur segment does not correlate with high mantle Bouguer anomalies (indicating thin crust and low melt flux). From this we hypothesise that total heave on the large scale at the Broken Spur segment is not controlled by crustal thickness or melt supply. At the Raykjanes Ridge, V-shaped ridges have thicker crust (measured seismically) which converge south of Iceland. These are thought to reflect transient (every 4-6 Myrs) pulses of hot mantle radiating away from the Iceland plume. We find ridge-symmetrical variation in fault heave but with a lower frequency (6-8 Myrs) and longer wavelength (3-7 Myrs) than the V-shaped ridges. Our analysis shows that plume pulses do not

  12. Mid Ocean Ridge Processes at Very Low Melt Supply : Submersible Exploration of Smooth Ultramafic Seafloor at the Southwest Indian Ridge, 64 degree E

    Science.gov (United States)

    Cannat, M.; Agrinier, P.; Bickert, M.; Brunelli, D.; Hamelin, C.; Lecoeuvre, A.; Lie Onstad, S.; Maia, M.; Prampolini, M.; Rouméjon, S.; Vitale Brovarone, A.; Besançon, S.; Assaoui, E. M.

    2017-12-01

    Mid-ocean ridges are the Earth's most extensive and active volcanic chains. They are also, particularly at slow spreading rates, rift zones, where plate divergence is in part accommodated by faults. Large offset normal faults, also called detachments, are characteristic of slow-spreading ridges, where they account for the widespread emplacement of mantle-derived rocks at the seafloor. In most cases, these detachments occur together with ridge magmatism, with melt injection and faulting interacting to shape the newly formed oceanic lithosphere. Here, we seek to better understand these interactions and their effects on oceanic accretion by studying the end-member case of a ridge where magmatism is locally almost absent. The portion of the Southwest Indian ridge we are studying has an overal low melt supply, focused to discrete axial volcanoes, leaving almost zero melt to intervening sections of the axial valley. One of these nearly amagmatic section of the ridge, located at 64°E, has been the focus of several past cruises (sampling, mapping and seismic experiments). Here we report on the most recent cruise to the area (RV Pourquoi Pas? with ROV Victor; dec-jan 2017), during which we performed high resolution mapping, submersible exploration and sampling of the ultramafic seafloor and of sparse volcanic formations. Our findings are consistent with the flip-flop detachment hypothesis proposed for this area by Sauter et al. (Nature Geosciences, 2013; ultramafic seafloor forming in the footwall of successive detachment faults, each cutting into the footwall of the previous fault, with an opposite polarity). Our observations also document the extent and geometry of deformation in the footwall of a young axial detachment, the role of mass-wasting for the evolution of this detachment, and provide spectacular evidence for serpentinization-related hydrothermal circulation and for spatial links between faults and volcanic eruptions.

  13. Waveform modeling of the seismic response of a mid-ocean ridge axial melt sill

    Science.gov (United States)

    Xu, Min; Stephen, R. A.; Canales, J. Pablo

    2017-12-01

    Seismic reflections from axial magma lens (AML) are commonly observed along many mid-ocean ridges, and are thought to arise from the negative impedance contrast between a solid, high-speed lid and the underlying low-speed, molten or partially molten (mush) sill. The polarity of the AML reflection ( P AML P) at vertical incidence and the amplitude vs offset (AVO) behavior of the AML reflections (e.g., P AML P and S-converted P AML S waves) are often used as a diagnostic tool for the nature of the low-speed sill. Time-domain finite difference calculations for two-dimensional laterally homogeneous models show some scenarios make the interpretation of melt content from partial-offset stacks of P- and S-waves difficult. Laterally heterogeneous model calculations indicate diffractions from the edges of the finite-width AML reducing the amplitude of the AML reflections. Rough seafloor and/or a rough AML surface can also greatly reduce the amplitude of peg-leg multiples because of scattering and destructive interference. Mid-crustal seismic reflection events are observed in the three-dimensional multi-channel seismic dataset acquired over the RIDGE-2000 Integrated Study Site at East Pacific Rise (EPR, cruise MGL0812). Modeling indicates that the mid-crustal seismic reflection reflections are unlikely to arise from peg-leg multiples of the AML reflections, P-to- S converted phases, or scattering due to rough topography, but could probably arise from deeper multiple magma sills. Our results support the identification of Marjanović et al. (Nat Geosci 7(11):825-829, 2014) that a multi-level complex of melt lenses is present beneath the axis of the EPR.

  14. A holistic model for the role of the axial melt lens at fast-spreading mid-ocean ridges

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    MacLeod, C. J.; Loocke, M. P.; Lissenberg, J. C. J.

    2016-12-01

    Axial melt lenses (AML) are melt or crystal mush1 bodies located at the dyke-gabbro transition beneath intermediate- and fast-spreading mid-ocean ridges (MORs)2,3. Although it is generally thought that AMLs play a major role in the storage and differentiation of mid-ocean ridge basalts (MORB)1, the melt compositions within the AML and its role in the accretion of the lower crust are heavily debated4-6. Here we present the first comprehensive study of the AML horizon at a fast-spreading MOR (Hess Deep, equatorial Pacific Ocean). We show that plagioclase and pyroxene within the AML are much too evolved to be in equilibrium with MORB, with mean An (54.85) and Mg# (65.01) consistent with derivation from basaltic andesite to andesite melts (Mg# 43-26). We propose that, in between decadal eruptions, the AML is predominantly crystal mush and is fed by small volumes of evolved interstitial melts. Short-lived, focused injection of primitive melt leads to mixing of primitive melts with the extant highly fractionated melt, and triggers eruptions. This model reconciles the paradoxical compositional mismatch between the volcanic and plutonic records with the geophysical characteristics of the AML, the short residence times of Pacific MORB phenocrysts, and the incompatible trace element over-enrichments in MORB. 1Marjanović, M. et al., 2015. Distribution of melt along the East Pacific Rise from 9°30' to 10°N from an amplitude variation with angle of incidence (AVA) technique. Geophys. J. Int. 203. 2Detrick, R. S. et al., 1987. Multi-channel seismic imaging of a crustal magma chamber along the EPR. Nature 326. 3Sinton, J. M. & Detrick, R. S., 1992. Mid-ocean ridge magma chambers. J. Geophys. Res. 97. 4Coogan, L. A., Thompson, G. & MacLeod, C. J., 2002. A textural and geochemical investigation of high level gabbros from the Oman ophiolite: implications for the role of the axial magma chamber at fast-spreading ridges. Lithos 63. 5Pan, Y. & Batiza, R., 2002. Mid-ocean ridge magma

  15. Technical Evaluation Summary of the In Situ Vitrification Melt Expulsion at the Oak Ridge National Laboratory on April 21, 1996, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1996-11-01

    This Technical Evaluation Summary of the In Situ Vitrification Melt Expulsion at the Oak Ridge National Laboratory on April 21, 1996, was prepared at the request of the Department of Energy as a supporting reference document for the Final Unusual Occurrence Report to fully explore the probable causes that lead to the subject incident. This document provides the Environmental Restoration Program with the technical information on the performance of the in situ vitrification treatability study operations at ORNL pit 1 up to and including the time of the melt expulsion incident. This document also attempts to diagnose the causes of the melt expulsion event the consequent damages to equipment the radiological impacts of the event, and the equipment design modifications and procedural changes necessary for future safe ISV operations

  16. The Cocos Ridge hydrothermal system revealed by microthermometry of fluid and melt inclusions

    Science.gov (United States)

    Brandstätter, J.; Kurz, W.; Krenn, K.

    2017-12-01

    Microthermometric analyses of fluid and melt inclusions in hydrothermal veins and in the Cocos Ridge (CCR) basalt were used to reveal the CCR thermal history at IODP Site 344-U1414 and to constrain fluid source and flow. Hydrothermal veins are hosted by lithified sediments and CCR basalt . Site 344-U1414, located 1 km seaward of the Middle American Trench offshore Costa Rica, serves to evaluate fluid/rock interaction, the hydrologic system and geochemical processes linked with the tectonic evolution of the incoming Cocos Plate from the Early Miocene up to recent times. The veins in the sedimentary rocks are mainly filled by blocky calcite, containing numerous fluid inclusions, and sometimes crosscut fibrous quartz/chalcedony veins. The veins in the basalt can be differentiated into three types: antitaxial fibrous calcite veins, composite veins with fibrous calcite and clay minerals at the vein margins and spherulitic quartz in the center, and syntaxial blocky aragonite veins surrounded by a clay selvage in the uppermost CCR basalt sections. Secondary minerals, clay minerals, fibrous calcite, quartz/chalcedony and pyrite also filled vesicles in the basalt. Fluid inclusions were mainly found in the aragonite veins and rarely in quartz in the composite veins and vesicles. Blocky veins with embedded wall rock fragments appear in the sediments and in the basalt indicate hydraulic fracturing. The occurrence of decrepitated fluid inclusions show high homogenization temperatures up to 400 °C. Decrepitated fluid inclusions are formed by increased internal overpressure, related to isobaric heating. Elongated fluid inclusion planes, arc-like fluid inclusions and low homogenization temperatures indicate subsequent isobaric cooling. The results obtained so far from Raman spectroscopy and microthermometry indicate CO2 inclusions and petrographic observations suggest the presence of silicate melt inclusions in phenocrysts in the basalt (mainly in clinopyroxene and plagioclase

  17. Technical evaluation of the in situ vitrification melt expulsion at the Oak Ridge National Laboratory on April 21, 1996, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1996-08-01

    On April 21, 1996, at 6:12 p.m., approximately 20 tons of molten glass were expelled from a 216-ton body of molten (approximately 1600 degrees C) radioactively contaminated soil (containing 2.4 Ci of 137 Cs) at a field site at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. The melt expulsion was caused by pressurized steam venting rapidly through, rather than by the desired path around, the molten body. During the previous 17 days, an old seepage pit was undergoing in situ vitrification (ISV) to convert it from porous, leachable soil into a monolithic, impermeable vitreous waste form. Approximately 2 MW of electrical power was being delivered to the molten body, which was contained in the ground and covered with a stainless steel hood maintained under negative pressure to collect, filter, scrub, and monitor off-gas. Off-gas into the hood was rapidly heated by the melt expulsion from a typical operating temperature of 250 degrees C to over 1000 degrees C with an associated surge of pressure sufficient to lift the 15,000-lb hood approximately 12 in. off the ground. A small pool of molten glass was able to flow up to 3 ft outside the hood while it was raised off the ground. The escaping hot off-gas and molten glass ignited several small fires in combustible components near or attached to the external hood frame (e.g, wire insulation, plastic hose, fiberglass trays). Fire department personnel responded to the emergency notification within minutes but were not needed because the small fires self-extinguished within an hour. Four project personnel were performing tasks at the site at the time of the melt expulsion; none were injured or contaminated during the melt expulsion incident. Air samples taken from the hood perimeter near the small fires failed to detect any airborne contamination

  18. Deep pooling of low degree melts and volatile fluxes at the 85°E segment of the Gakkel Ridge: Evidence from olivine-hosted melt inclusions and glasses

    Science.gov (United States)

    Shaw, Alison M.; Behn, Mark D.; Humphris, Susan E.; Sohn, Robert A.; Gregg, Patricia M.

    2010-01-01

    We present new analyses of volatile, major, and trace elements for a suite of glasses and melt inclusions from the 85°E segment of the ultra-slow spreading Gakkel Ridge. Samples from this segment include limu o pele and glass shards, proposed to result from CO 2-driven explosive activity. The major element and volatile compositions of the melt inclusions are more variable and consistently more primitive than the glass data. CO 2 contents in the melt inclusions extend to higher values (167-1596 ppm) than in the co-existing glasses (187-227 ppm), indicating that the melt inclusions were trapped at greater depths. These melt inclusions record the highest CO 2 melt concentrations observed for a ridge environment. Based on a vapor saturation model, we estimate that the melt inclusions were trapped between seafloor depths (˜ 4 km) and ˜ 9 km below the seafloor. However, the glasses are all in equilibrium with their eruption depths, which is inconsistent with the rapid magma ascent rates expected for explosive activity. Melting conditions inferred from thermobarometry suggest relatively deep (25-40 km) and cold (1240°-1325 °C) melting conditions, consistent with a thermal structure calculated for the Gakkel Ridge. The water contents and trace element compositions of the melt inclusions and glasses are remarkably homogeneous; this is an unexpected result for ultra-slow spreading ridges, where magma mixing is generally thought to be less efficient based on the assumption that steady-state crustal magma chambers are absent in these environments. All melts can be described by a single liquid line of descent originating from a pooled melt composition that is consistent with the aggregate melt calculated from a geodynamic model for the Gakkel Ridge. These data suggest a model in which deep, low degree melts are efficiently pooled in the upper mantle (9-20 km depth), after which crystallization commences and continues during ascent and eruption. Based on our melting model

  19. Ca/Al of plagioclase-hosted melt inclusions as an indicator for post-entrapment processes at mid-ocean ridges?

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.T.; Yang, Y.M.; Yan, Q.S.; Shi, Z.F.; Zhu, Z.W.; Su, W.C.; Qin, C.J.; Ye, J.

    2016-07-01

    The composition of melt inclusions in basalts erupted at mid-ocean ridges may be modified by post-entrapment processes, so the present composition of melt inclusions may not represent their original composition at the time of entrapment. By combining the melt inclusion composition in samples from the South Mid-Atlantic Ridge at 19°S analyzed in this study, and from the Petrological Database, we found that post-entrapment crystallization processes resulted in higher Ca/Al, Mg#[100×atomic Mg2+/(Mg2++Fe2+)], MgO and FeO contents, and lower CaO and Al2O3 contents of plagioclase-hosted melt inclusions relative to those hosted in olivine. In addition, melt inclusions hosted in plagioclase with anorthite content larger than 80mol.% had been modified more readily than others. By discussing the relationships between Ca/Al and fractional crystallization, post-entrapment crystallization, and the original melt composition, we propose that Ca/Al can be regarded as an indicator of the effect of post-entrapment processes on melt inclusion composition. Specifically, i) when Ca/Al<0.78, melt inclusion compositions corrected for fractional crystallization to Mg#=72 can represent the primary magma at mid-ocean ridges; ii) when 0.78melt inclusions are mainly modified by post-entrapment crystallization effects, and can reveal the original melt composition after correcting for these effects; iii) when Ca/Al>1.0, the compositions of melt inclusions do not reflect the original melt composition nor preserve information about the mantle source. According to these criteria, plagioclase-hosted melt inclusions with Ca/Al>1.0 in basalts from the South Mid-Atlantic Ridge at19°S cannot represent the composition of the melt at the moment of their entrapment. (Author)

  20. Cowley Ridge wind plant experiences best production year ever

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    The Cowley Ridge wind plant in southern Alberta in its fifth year of operation generated 63,380 MWh of electricity, exceeding its annual goal by about 15 per cent. December was one of the highest production months ever. During December the plant operated an an average of 62 per cent capacity throughout the month. The annual average is 35 per cent of capacity

  1. Crustal accretion along the global mid-ocean ridge system based on basaltic glass and olivine-hosted melt inclusion compositions

    Science.gov (United States)

    Wanless, V. D.; Behn, M. D.

    2015-12-01

    The depth and distribution of crystallization at mid-ocean ridges controls the overall architecture of the oceanic crust, influences hydrothermal circulation, and determines geothermal gradients in the crust and uppermost mantle. Despite this, there is no overall consensus on how crystallization is distributed within the crust/upper mantle or how this varies with spreading rate. Here, we examine crustal accretion at mid-ocean ridges by combining crystallization pressures calculated from major element barometers on mid-ocean ridge basalt (MORB) glasses with vapor-saturation pressures from melt inclusions to produce a detailed map of crystallization depths and distributions along the global ridge system. We calculate pressures of crystallization from >11,500 MORB glasses from the global ridge system using two established major element barometers (1,2). Additionally, we use vapor-saturation pressures from >400 olivine-hosted melt inclusions from five ridges with variable spreading rates to constrain pressures and distributions of crystallization along the global ridge system. We show that (i) crystallization depths from MORB glasses increase and become less focused with decreasing spreading rate, (ii) maximum glass pressures are greater than the maximum melt inclusion pressure, which indicates that the melt inclusions do not record the deepest crystallization at mid-ocean ridges, and (iii) crystallization occurs in the lower crust/upper mantle at all ridges, indicating accretion is distributed throughout the crust at all spreading rates, including those with a steady-state magma lens. Finally, we suggest that the remarkably similar maximum vapor-saturation pressures (~ 3000 bars) in melt inclusion from all spreading rates reflects the CO2 content of the depleted upper mantle feeding the global mid-ocean ridge system. (1) Michael, P. & W. Cornell (1998), Journal of Geophysical Research, 103(B8), 18325-18356; (2) Herzberg, C. (2004), Journal of Petrology, 45(12), 2389.

  2. Anatomy of a frozen axial melt lens from a fast-spreading paleo-ridge (Wadi Gideah, Oman ophiolite)

    Science.gov (United States)

    Müller, T.; Koepke, J.; Garbe-Schönberg, C.-D.; Dietrich, M.; Bauer, U.; Wolff, P. E.

    2017-02-01

    At fast-spreading mid-ocean ridges, axial melt lenses (AMLs) sandwiched between the sheeted dyke section and the uppermost gabbros are assumed to be the major magma source of crust formation. Here, we present our results from a field study based on a single outcrop of a frozen AML in the Samail ophiolite in the Sultanate of Oman which presents a whole suite of different lithologies and complex cutting relationships: varitextured gabbro with relics of primitive poikilitic clinopyroxene is intruded by massive quartz diorites and tonalites bearing relics of assimilated sheeted dykes, which in turn are cut by trondhjemite dykes. The whole is cut by basaltic dykes with chilled margins. The geochemical evolutionary trend of the varitextured gabbros, including some of the quartz diorites and tonalites, can be best modelled by fractional crystallisation of an experimental MORB parental melt composition containing 0.4 to 0.8 wt.% H2O. Patchy varitextured gabbros containing domains of primitive poikilitic clinopyroxene and evolved granular networks represent the record of in situ crystallisation. Some quartz diorites, often with xenoliths of sheeted dykes and exceptionally high Al2O3 contents, show a bulk trace element pattern more in accord with melts generated by experimental partial melting of dyke material. Highly evolved, crosscutting trondhjemite dykes show characteristic trace element patterns implying a formation by partial melting of sheeted dykes under lower water activity which is indicated by relatively low Al2O3 contents. The late basaltic dykes with chilled margins crosscutting all other lithologies show a relatively depleted geochemical character with pronounced negative Nb-Ta anomalies implying a genetic relationship to the second phase of magmatic Oman paleo-ridge activity (V2). The field relationships in combination with the petrological/geochemical trends reveal multiple sequences of MORB-type magma cooling (resulting in fractional crystallisation) and re

  3. Ca/Al of plagioclase-hosted melt inclusions as an indicator for post-entrapment processes at mid-ocean ridges?

    International Nuclear Information System (INIS)

    Zhang, H.T.; Yang, Y.M.; Yan, Q.S.; Shi, Z.F.; Zhu, Z.W.; Su, W.C.; Qin, C.J.; Ye, J.

    2016-01-01

    The composition of melt inclusions in basalts erupted at mid-ocean ridges may be modified by post-entrapment processes, so the present composition of melt inclusions may not represent their original composition at the time of entrapment. By combining the melt inclusion composition in samples from the South Mid-Atlantic Ridge at 19°S analyzed in this study, and from the Petrological Database, we found that post-entrapment crystallization processes resulted in higher Ca/Al, Mg#[100×atomic Mg2+/(Mg2++Fe2+)], MgO and FeO contents, and lower CaO and Al2O3 contents of plagioclase-hosted melt inclusions relative to those hosted in olivine. In addition, melt inclusions hosted in plagioclase with anorthite content larger than 80mol.% had been modified more readily than others. By discussing the relationships between Ca/Al and fractional crystallization, post-entrapment crystallization, and the original melt composition, we propose that Ca/Al can be regarded as an indicator of the effect of post-entrapment processes on melt inclusion composition. Specifically, i) when Ca/Al 1.0, the compositions of melt inclusions do not reflect the original melt composition nor preserve information about the mantle source. According to these criteria, plagioclase-hosted melt inclusions with Ca/Al>1.0 in basalts from the South Mid-Atlantic Ridge at19°S cannot represent the composition of the melt at the moment of their entrapment. (Author)

  4. Technical evaluation summary of the in situ vitrification melt expulsion at the Oak Ridge National Laboratory on April 21, 1996, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1996-07-01

    On April 21, 1996, at 6:12 PM, about 20 tons of molten glass were expelled from a 216-ton body of molten (1600 C) radioactively contaminated soil (containing 2.4 Ci 137 Cs) at an ORNL site. This was caused by pressurized steam venting rapidly through, rather than around, the molten body. During the previous 17 days, an old seepage pit was undergoing in situ vitrification to convert porous, leachable soil into an impermeable waste form. Analyses revealed that 0.13 μCi of 137 Cs could have been released and would have delivered a hypothetical, unmeasurable dose of 0.02 μrem to the nearest private residence outside the Oak Ridge Reservation. The expelled glass particles, having a uniform specific activity of 1.2E-08 Ci/g, contained no smearable or transferrable activity. Thus, the overall environmental impact was insignificant. Fire damage was completely limited to the off-gas hood. Techniques were identified to minimize the probability of future melt expulsions

  5. Uranium-series disequilibria of inflated sections of the Juan de Fuca Ridge: Implications for mantle melting

    Science.gov (United States)

    Dreyer, B. M.; Gill, J. B.; Ramos, F. C.; Clague, D. A.; Scott, S. R.

    2010-12-01

    U-Th disequilibria are reported for the two inflated portions (defined by bathymetric highs) of the Juan de Fuca Ridge (JdFR): Axial Seamount and the northern Endeavour segment. Both have broad axis-centered bathymetric plateaus, commonly attributed to the influence of the adjacent Heckle and Cobb melt anomalies, respectively. We explore structural and geochemical contrasts between them that imply fundamental differences in magma plumbing and/or transport processes. The depth to the axial magma chamber (AMC) within the JdFR crust is shallowest beneath Axial Seamount and deepest and most variable beneath Endeavour. Lavas from Endeavour include the most enriched and diverse compositions of the JdFR. Endeavour N-MORBs are most similar to Axial basalts in K2O/TiO2, La/Yb, Na8, and Fe8 although most Axial basalts have lower MgO. Major element trends suggest clinopyroxene saturation at higher MgO at Endeavour. Additional basalt types from Endeavour (i.e., those with K2O/TiO2 >0.15), the West Valley segment to the north, and Southwest Seamount to the west share similar enrichments in incompatible trace elements (Th, Nb) and radiogenic-Pb. Similar characteristics are absent from basalts from the adjacent Heck and Heckle seamount chains, which are highly-depleted N-MORBs, precluding the hypothesis that thickened and inflated crust at Endeavour is associated with increased melt supply due to transit over the seamount source. In contrast, Axial basalts are more chemically homogeneous, and share selected geochemical characteristics with the adjacent Cobb seamount chain. New uranium-series data suggest fundamental differences in melting parameters between inflated and non-inflated portions of the JdFR. Average Th/U at Endeavour (3.03 ± 6, n=10) is nearly indistinguishable from Axial (2.83 ± 9, n=17), but both are distinct from elsewhere on the JdFR (~2.1-2.5). That is, basalts erupted from regions of inflated crust have higher Th/U. Despite high overall compositional

  6. Mid-Ocean Ridge Melt Supply and Glacial Cycles: A 3D EPR Study of Crustal Thickness, Layer 2A, and Bathymetry

    Science.gov (United States)

    Boulahanis, B.; Aghaei, O.; Carbotte, S. M.; Huybers, P. J.; Langmuir, C. H.; Nedimovic, M. R.; Carton, H. D.; Canales, J. P.

    2017-12-01

    Recent studies suggest that eustatic sea level fluctuations induced by glacial cycles in the Pleistocene may influence mantle-melting and volcanic eruptions at mid-ocean ridges (MOR), with models predicting variation in oceanic crustal thickness linked to sea level change. Previous analyses of seafloor bathymetry as a proxy for crustal thickness show significant spectral energy at frequencies linked to Milankovitch cycles of 1/23, 1/41, and 1/100 ky-1, however the effects of faulting in seafloor relief and its spectral characteristics are difficult to separate from climatic signals. Here we investigate the hypothesis of climate driven periodicity in MOR magmatism through spectral analysis, time series comparisons, and statistical characterization of bathymetry data, seismic layer 2A thickness (as a proxy for extrusive volcanism), and seafloor-to-Moho thickness (as a proxy for total magma production). We utilize information from a three-dimensional multichannel seismic study of the East Pacific Rise and its flanks from 9°36`N to 9°57`N. We compare these datasets to the paleoclimate "LR04" benthic δ18O stack. The seismic dataset covers 770 km2 and provides resolution of Moho for 92% of the imaged region. This is the only existing high-resolution 3-D image across oceanic crust, making it ideal for assessing the possibility that glacial cycles modulate magma supply at fast spreading MORs. The layer 2A grid extends 9 km (170 ky) from the ridge axis, while Moho imaging extends to a maximum of 16 km (310 ky). Initial results from the East Pacific Rise show a relationship between sea level and both crustal thickness and sea floor depth, consistent with the hypothesis that magma supply to MORs may be modulated by glacial cycles. Analysis of crustal thickness and bathymetry data reveals spectral peaks at Milankovitch frequencies of 1/100 ky-1 and 1/41 ky-1 where datasets extend sufficiently far from the ridge. The layer 2A grid does not extend sufficiently far from the

  7. Fission Product Release from Spent Nuclear Fuel During Melting

    International Nuclear Information System (INIS)

    Howell, J.P.; Zino, J.F.

    1998-09-01

    The Melt-Dilute process consolidates aluminum-clad spent nuclear fuel by melting the fuel assemblies and diluting the 235U content with depleted uranium to lower the enrichment. During the process, radioactive fission products whose boiling points are near the proposed 850 degrees C melting temperature can be released. This paper presents a review of fission product release data from uranium-aluminum alloy fuel developed from Severe Accident studies. In addition, scoping calculations using the ORIGEN-S computer code were made to estimate the radioactive inventories in typical research reactor fuel as a function of burnup, initial enrichment, and reactor operating history and shutdown time.Ten elements were identified from the inventory with boiling points below or near the 850 degrees C reference melting temperature. The isotopes 137Cs and 85Kr were considered most important. This review serves as basic data to the design and development of a furnace off-gas system for containment of the volatile species

  8. Two-component mantle melting-mixing model for the generation of mid-ocean ridge basalts: Implications for the volatile content of the Pacific upper mantle

    Science.gov (United States)

    Shimizu, Kei; Saal, Alberto E.; Myers, Corinne E.; Nagle, Ashley N.; Hauri, Erik H.; Forsyth, Donald W.; Kamenetsky, Vadim S.; Niu, Yaoling

    2016-03-01

    We report major, trace, and volatile element (CO2, H2O, F, Cl, S) contents and Sr, Nd, and Pb isotopes of mid-ocean ridge basalt (MORB) glasses from the Northern East Pacific Rise (NEPR) off-axis seamounts, the Quebrada-Discovery-GoFar (QDG) transform fault system, and the Macquarie Island. The incompatible trace element (ITE) contents of the samples range from highly depleted (DMORB, Th/La ⩽ 0.035) to enriched (EMORB, Th/La ⩾ 0.07), and the isotopic composition spans the entire range observed in EPR MORB. Our data suggest that at the time of melt generation, the source that generated the EMORB was essentially peridotitic, and that the composition of NMORB might not represent melting of a single upper mantle source (DMM), but rather mixing of melts from a two-component mantle (depleted and enriched DMM or D-DMM and E-DMM, respectively). After filtering the volatile element data for secondary processes (degassing, sulfide saturation, assimilation of seawater-derived component, and fractional crystallization), we use the volatiles to ITE ratios of our samples and a two-component mantle melting-mixing model to estimate the volatile content of the D-DMM (CO2 = 22 ppm, H2O = 59 ppm, F = 8 ppm, Cl = 0.4 ppm, and S = 100 ppm) and the E-DMM (CO2 = 990 ppm, H2O = 660 ppm, F = 31 ppm, Cl = 22 ppm, and S = 165 ppm). Our two-component mantle melting-mixing model reproduces the kernel density estimates (KDE) of Th/La and 143Nd/144Nd ratios for our samples and for EPR axial MORB compiled from the literature. This model suggests that: (1) 78% of the Pacific upper mantle is highly depleted (D-DMM) while 22% is enriched (E-DMM) in volatile and refractory ITE, (2) the melts produced during variable degrees of melting of the E-DMM controls most of the MORB geochemical variation, and (3) a fraction (∼65% to 80%) of the low degree EMORB melts (produced by ∼1.3% melting) may escape melt aggregation by freezing at the base of the oceanic lithosphere, significantly enriching it in

  9. Fission Product Release from Molten Pool: ceramic melt tests

    Energy Technology Data Exchange (ETDEWEB)

    Petrov, Yu.B.; Lopukh, D.B.; Petchenkov, A.Yu. [AO ' NP Sintez' , St. Petersburg (RU)] [and others

    1999-07-01

    Experimental results are presented on the volatilisation of UO{sub 2{+-}}{sub x}, SrO, BaO, CeO{sub 2} from corium melts. Corium melts were generated by high frequency induction melting in a cold crucible. The surface temperature of the melts was in the range from 1753 to 3023 K. Some results of the tests are discussed and a comparison with published data is made. (author)

  10. Magma production rate along the Ninetyeast Ridge and its relationship to Indian plate motion and Kerguelen hot spot activity

    Digital Repository Service at National Institute of Oceanography (India)

    Sreejith, K.M.; Krishna, K.S.

    production rate along the Walvis Ridge in the Atlantic Ocean. The present study suggests that variations in the Indian plate motion and frequent ridge jumps have a major role in controlling the magma production, particularly on long-period cycles (~16 Myr...

  11. Fission product source term research at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Malinauskas, A.P.

    1985-01-01

    The purpose of this work is to describe some of the research being performed at ORNL in support of the effort to describe, as realistically as possible, fission product source terms for nuclear reactor accidents. In order to make this presentation manageable, only those studies directly concerned with fission product behavior, as opposed to thermal hydraulics, accident sequence progression, etc., will be discussed

  12. Ridge Regression: A tool to forecast wheat area and production

    Directory of Open Access Journals (Sweden)

    Nasir Jamal

    2007-07-01

    Full Text Available This research study is designed to develop forecasting models for acreage and production of wheat crop for Chakwal district of Rawalpindi region keeping in view the assumptions of OLS estimation. The forecasting models are developed on the basis of 15 years data from 1984-85 to 1998-99 then wheat area and production for next five years from 1999-2000 to 2003-04 is forecasted through the models and compared with the actual figures. After evaluating the accuracy of the models, final models are developed on the basis of 20 years data for the period 1984-85 to 2003-04. These linear models can be used to forecast wheat area and production of next five years. The Urea fertilizer, DAP fertilizer and manures plays a significant role to enhance the production of wheat crop. Number of ploughs in the wheat fields is significant factor to increase the production of wheat crop. Good rains in the month of October and November significantly contributes to increase the production of wheat crop and mean maximum temperature in the month of March is a significant factor to reduce the production of wheat crop.

  13. Amphibole and felsic veins from the gabbroic oceanic core complex of Atlantis Bank (Southwest Indian Ridge, IODP Hole U1473A): when the fluids meets the melts

    Science.gov (United States)

    Sanfilippo, A.; Tribuzio, R.; Antonicelli, M.; Zanetti, A.

    2017-12-01

    We present a petrological/geochemical investigation of brown amphibole and felsic veins drilled during IODP 360 expedition at Atlantis Bank, a gabbroic oceanic core complex from Southwest Indian Ridge. The main purpose of this study is to unravel the role of seawater and magmatic components in the origin of these veins. Brown amphibole veins were collected at 90-170 mbsf. These veins typically include minor modal amounts of plagioclase and are associated with alteration halos made up of brown amphibole and whitish milky plagioclase in host gabbros. Two sets of late magmatic felsic veins, which mostly consist of plagioclase and minor brown amphibole, were selected. Amphibole-plagioclase geothermometry (Holland and Blundy, 1994) documents that crystallization of brown amphibole and felsic veins occurred in the 850-700 °C interval. In the brown amphibole veins, amphibole and plagioclase have relatively low concentrations of incompatible trace elements and significant Cl (0.2-0.3 wt%). The development of these veins at near surface levels is therefore attributed to seawater-derived fluids migrating downward through cracks developing in the exhuming gabbro. To explain the high temperature estimates for the development of these shallow veins, however, the seawater-derived fluids must have interacted not only with the gabbros, but also with a high temperature magmatic component. This petrogenetic hypothesis is consistent with oxygen and hydrogen isotopic compositions of amphiboles from shallow veins in adjacent Hole 735B gabbros (Alt and Bach, 2006). Trace element compositions of amphibole and plagioclase from the felsic veins show formation by silicate melts rich in incompatible elements. In addition, Cl concentrations in amphibole from the felsic veins are low, thereby indicating that the melts feeding these veins had low or no seawater component. We cautiously propose that: (i) the felsic veins were generated by SiO2-rich melts residual after crystallization of Fe

  14. Product differentiation by analysis of DNA melting curves during the polymerase chain reaction.

    Science.gov (United States)

    Ririe, K M; Rasmussen, R P; Wittwer, C T

    1997-02-15

    A microvolume fluorometer integrated with a thermal cycler was used to acquire DNA melting curves during polymerase chain reaction by fluorescence monitoring of the double-stranded DNA specific dye SYBR Green I. Plotting fluorescence as a function of temperature as the thermal cycler heats through the dissociation temperature of the product gives a DNA melting curve. The shape and position of this DNA melting curve are functions of the GC/AT ratio, length, and sequence and can be used to differentiate amplification products separated by less than 2 degrees C in melting temperature. Desired products can be distinguished from undesirable products, in many cases eliminating the need for gel electrophoresis. Analysis of melting curves can extend the dynamic range of initial template quantification when amplification is monitored with double-stranded DNA specific dyes. Complete amplification and analysis of products can be performed in less than 15 min.

  15. Gamma titanium aluminide production using the Induction Skull Melting (ISM) process

    International Nuclear Information System (INIS)

    Reed, S.

    1995-01-01

    Since 1985, more than 2,000 titanium aluminide heats have been produced using the Induction Skull Melting (ISM) process. The history of ISM/Gamma production will be discussed in this paper. Gamma titanium aluminide processing with Induction Skull Melting offers many advantages over other types of reactive alloy melting methods. These advantages will be discussed as well as drawbacks. Also, potential markets and applications for ISM/Gamma will be presented

  16. Nutrient availability limits biological production in Arctic sea ice melt ponds

    DEFF Research Database (Denmark)

    Sørensen, Heidi Louise; Thamdrup, Bo; Jeppesen, Erik

    2017-01-01

    nutrient limitation in melt ponds. We also document that the addition of nutrients, although at relative high concentrations, can stimulate biological productivity at several trophic levels. Given the projected increase in first-year ice, increased melt pond coverage during the Arctic spring and potential......Every spring and summer melt ponds form at the surface of polar sea ice and become habitats where biological production may take place. Previous studies report a large variability in the productivity, but the causes are unknown. We investigated if nutrients limit the productivity in these first...... additional nutrient supply from, e.g. terrestrial sources imply that biological activity of melt ponds may become increasingly important for the sympagic carbon cycling in the future Arctic....

  17. The hardness of synthetic products obtained from cooled and crystallized basaltic melts (in Romanian)

    OpenAIRE

    Daniela Ogrean

    2001-01-01

    The Hardness of Synthetic Products Obtained from Cooled and Crystallized Basaltic Melts. Hardness is one of the main properties of the products obtained from cooled and crystallized basaltic melts under a controlled thermal regime. It influences the abrasion tear resistance of the resulted material. The microhardness measurements on the samples (bricks, boards, gutters, armour plates, tubes) indicated Vickers hardness value between 757–926 for the materials obtained from Şanovita basalts (Tim...

  18. Oak Ridge Isotope Products and Services - Current and Expected Supply and Demand

    International Nuclear Information System (INIS)

    Aaron, W.S.; Alexander, C.W.; Cline, R.L.; Collins, E.D.; Klein, J.A.; Knauer, J.B. Jr.; Mirzadeh, S.

    1999-01-01

    Oak Ridge National Laboratory (ORNL) has been a major center of isotope production research, development, and distribution for over 50 years. Currently, the major isotope production activities include (1) the production of transuranium element radioisotopes, including 252 Cf; (2) the production of medical and industrial radioisotopes; (3) maintenance and expansion of the capabilities for production of enriched stable isotopes; and, (4) preparation of a wide range of custom-order chemical and physical forms of isotope products, particularly in accelerator physics research. The recent supply of and demand for isotope products and services in these areas, research and development (R ampersand D), and the capabilities for future supply are described in more detail below. The keys to continuing the supply of these important products and services are the maintenance, improvement, and potential expansion of specialized facilities, including (1) the High Flux Isotope Reactor (HFIR), (2) the Radiochemical Engineering Development Center (REDC) and Radiochemical Development Laboratory (RDL) hot cell facilities, (3) the electromagnetic calutron mass separators and the plasma separation process equipment for isotope enrichment, and (4) the Isotope Research Materials Laboratory (IRML) equipment for preparation of specialized chemical and physical forms of isotope products. The status and plans for these ORNL isotope production facilities are also described below

  19. On the sequence of core-melt accidents: Fission product release, source terms and Chernobyl release

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, H

    1986-01-01

    There is a sketch of our ideas on the course of a core melt-out accident in a PWR. There is then a survey of the most important results on fission product release, which were obtained by experiments on the SASCHA melt-out plant. The 3rd part considers questions which are important for determining source terms for the environment and the last part contains some considerations on radioactivity release from the Chernobyl reactor.

  20. Melt migration modeling in partially molten upper mantle

    Science.gov (United States)

    Ghods, Abdolreza

    beneath the observed neo-volcanic zone. My models consist of three parts; lithosphere, asthenosphere and a melt extraction region. It is shown that melt migrates vertically within the asthenosphere, and forms a high melt fraction layer beneath the sloping base of the impermeable lithosphere. Within the sloping high melt fraction layer, melt migrates laterally towards the ridge. In order to simulate melt migration via crustal fractures and cracks, melt is extracted from a melt extraction region extending to the base of the crust. Performance of the melt focusing mechanism is not significantly sensitive to the size of melt extraction region, melt extraction threshold and spreading rate. In all of the models, about half of the total melt production freezes beneath the cooling base of the lithosphere, and the rest is effectively focused towards the ridge and forms the crust. To meet the computational demand for a precise tracing of the deforming upwelling plume and including the chemical buoyancy of the partially molten zone in my models, a new numerical method is developed to solve the related pure advection equations. The numerical method is based on Second Moment numerical method of Egan and Mahoney [1972] which is improved to maintain a high numerical accuracy in shear and rotational flow fields. In comparison with previous numerical methods, my numerical method is a cost-effective, non-diffusive and shape preserving method, and it can also be used to trace a deforming body in compressible flow fields.

  1. Actinide, lanthanide and fission product speciation and electrochemistry in high and low temperature ionic melts

    Energy Technology Data Exchange (ETDEWEB)

    Bhatt, Anand I.; Kinoshita, Hajime; Koster, Anne L.; May, Iain; Sharrad, Clint A.; Volkovich, Vladimir A.; Fox, O. Danny; Jones, Chris J.; Lewin, Bob G.; Charnock, John M.; Hennig, Christoph

    2004-07-01

    There is currently a great deal of research interest in the development of molten salt technology, both classical high temperature melts and low temperature ionic liquids, for the electrochemical separation of the actinides from spent nuclear fuel. We are interested in gaining a better understanding of actinide and key fission product speciation and electrochemical properties in a range of melts. Our studies in high temperature alkali metal melts (including LiCl and LiCl-KCl and CsCl-NaCl eutectics) have focussed on in-situ species of U, Th, Tc and Ru using X-ray absorption spectroscopy (XAS, both EXAFS and XANES) and electronic absorption spectroscopy (EAS). We report unusual actinide speciation in high temperature melts and an evaluation of the likelihood of Ru or Tc volatilization during plant operation. Our studies in lower temperature melts (ionic liquids) have focussed on salts containing tertiary alkyl group 15 cations and the bis(tri-fluor-methyl)sulfonyl)imide anion, melts which we have shown to have exceptionally wide electrochemical windows. We report Ln, Th, U and Np speciation (XAS, EAS and vibrational spectroscopy) and electrochemistry in these melts and relate the solution studies to crystallographic characterised benchmark species. (authors)

  2. Actinide, lanthanide and fission product speciation and electrochemistry in high and low temperature ionic melts

    International Nuclear Information System (INIS)

    Bhatt, Anand I.; Kinoshita, Hajime; Koster, Anne L.; May, Iain; Sharrad, Clint A.; Volkovich, Vladimir A.; Fox, O. Danny; Jones, Chris J.; Lewin, Bob G.; Charnock, John M.; Hennig, Christoph

    2004-01-01

    There is currently a great deal of research interest in the development of molten salt technology, both classical high temperature melts and low temperature ionic liquids, for the electrochemical separation of the actinides from spent nuclear fuel. We are interested in gaining a better understanding of actinide and key fission product speciation and electrochemical properties in a range of melts. Our studies in high temperature alkali metal melts (including LiCl and LiCl-KCl and CsCl-NaCl eutectics) have focussed on in-situ species of U, Th, Tc and Ru using X-ray absorption spectroscopy (XAS, both EXAFS and XANES) and electronic absorption spectroscopy (EAS). We report unusual actinide speciation in high temperature melts and an evaluation of the likelihood of Ru or Tc volatilization during plant operation. Our studies in lower temperature melts (ionic liquids) have focussed on salts containing tertiary alkyl group 15 cations and the bis(tri-fluor-methyl)sulfonyl)imide anion, melts which we have shown to have exceptionally wide electrochemical windows. We report Ln, Th, U and Np speciation (XAS, EAS and vibrational spectroscopy) and electrochemistry in these melts and relate the solution studies to crystallographic characterised benchmark species. (authors)

  3. An innovative energy-saving in-flight melting technology and its application to glass production

    Directory of Open Access Journals (Sweden)

    Yaochun Yao et al

    2008-01-01

    Full Text Available The conventional method used for glass melting is air-fuel firing, which is inefficient, energy-intensive and time-consuming. In this study, an innovative in-flight melting technology was developed and applied to glass production for the purposes of energy conservation and environmental protection. Three types of heating sources, radio-frequency (RF plasma, a 12-phase alternating current (ac arc and an oxygen burner, were used to investigate the in-flight melting behavior of granulated powders. Results show that the melted particles are spherical with a smooth surface and compact structure. The diameter of the melted particles is about 50% of that of the original powders. The decomposition and vitrification degrees of the prepared powders decrease in the order of powders prepared by RF plasma, the 12-phase ac arc and the oxygen burner. The largest heat transfer is from RF plasma to particles, which results in the highest particle temperature (1810 °C and the greatest vitrification degree of the raw material. The high decomposition and vitrification degrees, which are achieved in milliseconds, shorten the melting and fining times of the glass considerably. Our results indicate that the proposed in-flight melting technology is a promising method for use in the glass industry.

  4. REACTION PRODUCTS AND CORROSION OF MOLYBDENUM ELECTRODE IN GLASS MELT CONTAINING ANTIMONY OXIDES AND SODIUM SULFATE

    Directory of Open Access Journals (Sweden)

    JIŘÍ MATĚJ

    2012-09-01

    Full Text Available The products on the interface of a molybdenum electrode and glass melt were investigated primarily at 1400°C in three model glass melts without ingredients, with 1 % Sb2O3 and with 1 % Sb2O3 and 0.5 % SO3 (wt. %, both under and without load by alternating current. Corrosion of the molybdenum electrode in glass melt without AC load is higher by one order of magnitude if antimony oxides are present. The corrosion continues to increase if sulfate is present in addition to antimony oxides. Isolated antimony droplets largely occur on the electrode-glass melt interface, and numerous droplets are also dissipated in the surrounding glass if only antimony oxides are present in the glass melt. A comparatively continuous layer of antimony occurs on the interface if SO3 is also present, antimony being always in contact with molybdenum sulfide. Almost no antimony droplets are dissipated in the glass melt. The total amount of precipitated antimony also increases. The presence of sulfide on the interface likely facilitates antimony precipitation. The reaction of molybdenum with antimony oxides is inhibited in sites covered by an antimony layer. The composition of sulfide layers formed at 1400°C approximates that of Mo2S3. At 1100°C, the sulfide composition approximates that of MoS4. Corrosion multiplies in the glass melt without additions through the effect of AC current, most molybdenum being separated in the form of metallic particles. Corrosion also increases in the glass melt containing antimony oxides. This is due to increased corrosion in the neighborhood of the separated antimony droplets. This mechanism also results in the loosening of molybdenum particles. The amount of precipitated antimony also increases through the effect of the AC current. AC exerts no appreciable effect on either corrosion, the character of the electrode-glass interface, or antimony precipitation in the glass melt containing SO3.

  5. Variability of Fe isotope compositions of hydrothermal sulfides and oxidation products at mid-ocean ridges

    Science.gov (United States)

    Li, Xiaohu; Wang, Jianqiang; Chu, Fengyou; Wang, Hao; Li, Zhenggang; Yu, Xing; Bi, Dongwei; He, Yongsheng

    2018-04-01

    Significant Fe isotopic fractionation occurs during the precipitation and oxidative weathering of modern seafloor hydrothermal sulfides, which has an important impact on the cycling of Fe isotopes in the ocean. This study reports the Fe-isotope compositions of whole-rock sulfides and single-mineral pyrite collected from hydrothermal fields at the South Mid-Atlantic Ridge (SMAR) and the East Pacific Rise (EPR) and discusses the impacts of precipitation and late-stage oxidative weathering of sulfide minerals on Fe isotopic fractionation. The results show large variation in the Fe-isotope compositions of the sulfides from the different hydrothermal fields on the mid-oceanic ridges, indicating that relatively significant isotope fractionation occurs during the sulfide precipitation and oxidative weathering processes. The Fe-isotope compositions of the sulfides from the study area at the SMAR vary across a relatively small range, with an average value of 0.01‰. This Fe-isotope composition is similar to the Fe-isotope composition of mid-oceanic ridge basalt, which suggests that Fe was mainly leached from basalt. In contrast, the Fe-isotope composition of the sulfides from the study area at the EPR are significantly enriched in light Fe isotopes (average value - 1.63‰), mainly due to the kinetic fractionation during the rapid precipitation process of hydrothermal sulfide. In addition, the pyrite from different hydrothermal fields is enriched in light Fe isotopes, which is consistent with the phenomenon in which light Fe isotopes are preferentially enriched during the precipitation of pyrite. The red oxides have the heaviest Fe-isotope compositions (up to 0.80‰), indicating that heavy Fe isotopes are preferentially enriched in the oxidation product during the late-stage oxidation process. The data obtained from this study and previous studies show a significant difference between the Fe-isotope compositions of the sulfides from the SMAR and EPR. The relatively heavy

  6. Stabilization and shutdown of Oak Ridge National Laboratory's Radioisotopes Production Facility

    International Nuclear Information System (INIS)

    Eversole, R.E.

    1992-01-01

    The Oak Ridge National Laboratory (ORNL) has been involved in the production and distribution of a variety of radioisotopes for medical, scientific and industrial applications since the late 1940s. Production of these materials was concentrated in a number of facilities primarily built in the 1950s and 1960s. Due to the age and deteriorating condition of these facilities, it was determined in 1989 that it would not be cost effective to upgrade these facilities to bring them into compliance with contemporary environmental, safety and health standards. The US Department of Energy (DOE) instructed ORNL to halt the production of isotopes in these facilities and maintain the facilities in safe standby condition while preparing a stabilization and shutdown plan. The goal was to place the former isotope production facilities in a radiologically and industrially safe condition to allow a 5-year deferral of the initiation of environmental restoration (ER) activities. In response to DOE's instructions, ORNL identified 17 facilities for shutdown, addressed the shutdown requirements for each facility, and prepared and implemented a three-phase, 4-year plan for shutdown of the facilities. The Isotopes Facilities Shutdown Program (IFSP) office was created to execute the stabilization and shutdown plan. The program is entering its third year in which the actual shutdown of the facilities is initiated. Accomplishments to date have included consolidation of all isotopes inventory into one facility, DOE approval of the IFSP Environmental Assessment (EA), and implementation of a detailed management plan for the shutdown of the facilities

  7. Isotope materials availability and services for target production at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Ratledge, J.E.; Dahl, T.L.; Ottinger, C.L.; Aaron, W.S.; Adair, H.L.

    1987-01-01

    Materials available through the Isotope Distribution Program include separated stable isotopes, byproduct radioisotopes, and research quantities of source and special nuclear materials. Isotope products are routinely available in the forms listed in the product description section of the Isotopes Products and Services Catalog distributed by the Oak Ridge National Laboratory (ORNL). Different forms can be provided in some cases, usually at additional cost. Routinely available services include cyclotron target irradiations, fabrication of special physical forms, source encapsulation, ion implantation, and special purifications. Materials and services that are not offered as part of the routine distribution program may be made available from commercial sources in the United States. Specific forms of isotopic research materials include thin films and foils for use as accelerator targets, metal or other compounds in the form of bars or wires, and metal foils. Methods of fabrication include evaporation, sputtering, rolling, electrolytic deposition, pressing, sintering, and casting. High-purity metal forms of plutonium, americium, and curium are prepared by vacuum reduction/distillation. Both fissionable and nonfissionable neutron dosimeters are prepared for determining the neutron energy spectra, flux, and fluence at various locations within a reactor. Details on what materials are available and how the materials and related services can be obtained from ORNL are described. (orig.)

  8. Spread of fission products after a nuclear melt-down accident

    International Nuclear Information System (INIS)

    Andriesse, C.D.; Tanke, R.H.J.

    1987-01-01

    In this article experimental investigation is described into the spread of fission products within a nuclear power plant, which after an accident involving melting of the nucleus, will be possible in spite of prohibiting constructions for the case of severe unbalancing of generated and carried-off energy. 6 refs.; 4 figs

  9. Structure, production and properties of high-melting compounds and systems (hard materials and hard metals)

    International Nuclear Information System (INIS)

    Holleck, H.; Thuemmler, F.

    1979-07-01

    The report contains contributions by various authors to the research project on the production, structure, and physical properties of high-melting compounds and systems (hard metals and hard materials), in particular WC-, TaC-, and MoC-base materials. (GSCH) [de

  10. Melt-drop technique for the production of high-purity metal powder

    International Nuclear Information System (INIS)

    Aldinger, F.; Linck, E.; Claussen, N.

    1977-01-01

    The production of high-purity powders of metals and alloys such as beryllium, titanium alloys, or superalloys is a problem. Oxidation of these materials cannot be avoided. Oxidation occurs in inert gases and even in reducing atmospheres when any gas impurities are present. Therefore, the powder production of these materials has to be performed either in high vacuum or at least in a static atmosphere of inert gas purified immediately before coming into contact with the disintegrating material. These requirements are very well met by the melt-drop technique presented in this paper, especially for coarse powders which must not necessarily be cold-workable. This is true, for example, for superalloys where high-temperature applications require large grain sizes; or in titanium alloys because the final microstructure will be achieved by a thermomechanical treatment. In the case of beryllium and beryllium alloys, where grain sizes <5 μm are desired, further milling is necessary. But the melt-drop technique offers a simple and clean method directly from the purifying process of vacuum melting. In melt-drop processes a liquid metal flows through a nozzle at the bottom of a crucible or the melt is just poured through a sieve. The theory of disintegration of a liquid jet into droplets, dates back to the 19th century. More recent investigations attempted to produce uniformly sized droplets by applying a capillary wave of given wave length to the jet. But this has been done only with non-metallic materials. Evidence is presented to prove the theory and show that this concept is applicable to the production of metal powders with controlled particle size

  11. The hardness of synthetic products obtained from cooled and crystallized basaltic melts (in Romanian

    Directory of Open Access Journals (Sweden)

    Daniela Ogrean

    2001-04-01

    Full Text Available The Hardness of Synthetic Products Obtained from Cooled and Crystallized Basaltic Melts. Hardness is one of the main properties of the products obtained from cooled and crystallized basaltic melts under a controlled thermal regime. It influences the abrasion tear resistance of the resulted material. The microhardness measurements on the samples (bricks, boards, gutters, armour plates, tubes indicated Vickers hardness value between 757–926 for the materials obtained from Şanovita basalts (Timiş district and between 539–958 respectively, in case of the Racoş basalts (Braşov district. There is a certain variation of the hardness within the same sample, in various measurement points, within the theoretical limits of the hardnesses of the pyroxenes and that of the spinels.

  12. Material interactions between system components and glass product melts in a ceramic melter

    International Nuclear Information System (INIS)

    Knitter, R.

    1989-07-01

    The interactions of the ceramic and metallic components of a ceramic melter for the vitrification of High Active Waste were investigated with simulated glass product melts in static crucible tests at 1000 0 C and 1150 0 C. Corrosion of the fusion-cast Al 2 O 3 -ZrO 2 -SiO 2 - and Al 2 O 3 -ZrO 2 -SiO 2 -Cr 2 O 3 -refractories (ER 1711 and ER 2161) is characterized by homogeneous chemical dissolution and diffusion through the glass matrix of the refractory. The resulting boundary compositions lead to characteristic modification and formation of phases, not only inside the refractory but also in the glass melt. The attack of the electrode material, a Ni-Cr-Fe-alloy Inconel 690, by the glass melt takes place via grain boundaries and leads to the oxidation of Cr and growth of Cr 2 O 3 -crystals at the boundary layer. Noble metals, added to the glass melt can form solid solutions with the alloy with varying compositions. (orig.) [de

  13. Deformation mechanisms and melt nano-structures in experimentally deformed olivine-orthopyroxene rocks with low melt fractions

    NARCIS (Netherlands)

    Kloe, P.A. de

    2001-01-01

    The major part of the Earth’s upper mantle is thought to be solid, with some regions in the mantle where the rocks contain a small melt fraction These partially molten rocks are associated with important geological processes such as magma production beneath mid-oceanic ridges and may also play an

  14. Decontamination and decommissioning of the fission product pilot plant at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Mandry, G.J.; Snedaker, W.

    1994-11-01

    The Fission Product Pilot Plant (FPPP) at the Oak Ridge National Laboratory (ORNL) was one of the first facilities used to extract radioactive isotopes from liquid radioactive wastes. During operations, the FPPP was extensively contaminated, resulting in high radiation levels even 30 years after the conclusion of operations. The facility has been abandoned for over 20 years and is now a candidate for decontamination and decommissioning (D ampersand D). In fact, the ORNL management has begun activities toward the D ampersand D of the FPPP. Two of these activities were completed in 1993 and 1994. The first 2030 activity was a facility characterization designed to assess the condition of the interior of the FPPP and to quantify, if possible, the amounts and identities of any radioactive contaminants and hazardous materials as defined by the U.S. Environmental Protection Agency. The facility characterization was intended to determine the condition of the interior, the complement of equipment left in the facility at the time of its closure, and the radiation environment that would be encountered during its D ampersand D. The second activity was an alternatives assessment designed to determine the best approach to the D ampersand D of the FPPP. The alternatives assessment examined five alternatives to decontaminate and decommission the FPPP and recommended the best alternative for its disposition. The first section of the paper describes the FPPP and its history. It includes the various conjectures on what exactly was done when the FPPP was entombed with the shield wall visible in today's pictures. The next section discusses the characterization that was performed concurrently with the alternatives evaluation. The next two sections detail the D ampersand D plan for the complete dismantelment of the FPPP and its estimated cost and schedule

  15. Production of Magnesium and Aluminum-Magnesium Alloys from Recycled Secondary Aluminum Scrap Melts

    Science.gov (United States)

    Gesing, Adam J.; Das, Subodh K.; Loutfy, Raouf O.

    2016-02-01

    An experimental proof of concept was demonstrated for a patent-pending and trademark-pending RE12™ process for extracting a desired amount of Mg from recycled scrap secondary Al melts. Mg was extracted by electrorefining, producing a Mg product suitable as a Mg alloying hardener additive to primary-grade Al alloys. This efficient electrorefining process operates at high current efficiency, high Mg recovery and low energy consumption. The Mg electrorefining product can meet all the impurity specifications with subsequent melt treatment for removing alkali contaminants. All technical results obtained in the RE12™ project indicate that the electrorefining process for extraction of Mg from Al melt is technically feasible. A techno-economic analysis indicates high potential profitability for applications in Al foundry alloys as well as beverage—can and automotive—sheet alloys. The combination of technical feasibility and potential market profitability completes a successful proof of concept. This economical, environmentally-friendly and chlorine-free RE12™ process could be disruptive and transformational for the Mg production industry by enabling the recycling of 30,000 tonnes of primary-quality Mg annually.

  16. Dropwise additive manufacturing of pharmaceutical products for melt-based dosage forms.

    Science.gov (United States)

    Içten, Elçin; Giridhar, Arun; Taylor, Lynne S; Nagy, Zoltan K; Reklaitis, Gintaras V

    2015-05-01

    The US Food and Drug Administration introduced the quality by design approach and process analytical technology guidance to encourage innovation and efficiency in pharmaceutical development, manufacturing, and quality assurance. As part of this renewed emphasis on the improvement of manufacturing, the pharmaceutical industry has begun to develop more efficient production processes with more intensive use of online measurement and sensing, real-time quality control, and process control tools. Here, we present dropwise additive manufacturing of pharmaceutical products (DAMPP) as an alternative to conventional pharmaceutical manufacturing methods. This mini-manufacturing process for the production of pharmaceuticals utilizes drop on demand printing technology for automated and controlled deposition of melt-based formulations onto edible substrates. The advantages of drop-on-demand technology, including reproducible production of small droplets, adjustable drop sizing, high placement accuracy, and flexible use of different formulations, enable production of individualized dosing even for low-dose and high-potency drugs. In this work, DAMPP is used to produce solid oral dosage forms from hot melts of an active pharmaceutical ingredient and a polymer. The dosage forms are analyzed to show the reproducibility of dosing and the dissolution behavior of different formulations. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  17. Considerations in modelling the melting of fuel containing fission products and solute oxides

    International Nuclear Information System (INIS)

    Akbari, F.; Welland, M.J.; Lewis, B.J.; Thompson, W.T.

    2005-01-01

    It is well known that the oxidation of a defected fuel element by steam gives rise to an increase in O/U ratio with a consequent lowering of the incipient melting temperature. Concurrently, the hyperstoichiometry reduces the thermal conductivity thereby raising the centerline fuel pellet temperature for a fixed linear power. The development of fission products soluble in the UO 2 phase or, more important, the deliberate introduction of additive oxides in advanced CANDU fuel bundle designs further affects and generally lowers the incipient melting temperature. For these reasons, the modeling of the molten (hyperstoichiometric) UO 2 phase containing several solute oxides (ZrO 2 , Ln 2 O 3 and AnO 2 ) is advancing in the expectation of developing a moving boundary heat and mass transfer model aimed at better defining the limits of safe operating practice as burnup advances. The paper describes how the molten phase stability model is constructed. The redistribution of components across the solid-liquid interface that attends the onset of melting of a non-stoichiometric UO 2 containing several solutes will be discussed. The issues of how to introduce boundary conditions into heat transfer calculations consistent with the requirements of the Phase Rule will be addressed. The Stefan problem of a moving boundary associated with the solid/liquid interface sets this treatment apart from conventional heat and mass transfer problems. (author)

  18. Behavior of americium, curium, and certain fission products in fluoride melts in the presence of s olid extraction agents

    International Nuclear Information System (INIS)

    Alekseev, V.A.; Klokman, V.R.; Morozova, Z.E.; Ziv, V.S.

    1986-01-01

    The authors consider the behavior of americium, curium, and certain fission products (europium, cerium, yttrium, and strontium) in fluoride and chlode-fluoride melts in the presence of nonisomorphous solid phases: calcium fluoride and lanthanum and zirconium oxides. It is shown that the trace components enter the solid calcium fluoride in a regular fashion only in the presence of an adequate amount of oxygen in the melt. The effect of oxygen on the coprecipitation with calcium fluoride occurs because oxygen compounds of the elements must be formed in the melt, and these are then coprecipitated with the calcium fluoride

  19. Seismological Imaging of Melt Production Regions Beneath the Backarc Spreading Center and Volcanic Arc, Mariana Islands

    Science.gov (United States)

    Wiens, Douglas; Pozgay, Sara; Barklage, Mitchell; Pyle, Moira; Shiobara, Hajime; Sugioka, Hiroko

    2010-05-01

    We image the seismic velocity and attenuation structure of the mantle melt production regions associated with the Mariana Backarc Spreading Center and Mariana Volcanic Arc using data from the Mariana Subduction Factory Imaging Experiment. The passive component of this experiment consisted of 20 broadband seismographs deployed on the island chain and 58 ocean-bottom seismographs from June, 2003 until April, 2004. We obtained the 3D P and S wave velocity structure of the Mariana mantle wedge from a tomographic inversion of body wave arrivals from local earthquakes as well as P and S arrival times from large teleseismic earthquakes determined by multi-channel cross correlation. We also determine the 2-D attenuation structure of the mantle wedge using attenuation tomography based on local and regional earthquake spectra, and a broader-scale, lower resolution 3-D shear velocity structure from inversion of Rayleigh wave phase velocities using a two plane wave array analysis approach. We observe low velocity, high attenuation anomalies in the upper mantle beneath both the arc and backarc spreading center. These anomalies are separated by a higher velocity, lower attenuation region at shallow depths (< 80 km), implying distinct magma production regions for the arc and backarc in the uppermost mantle. The largest magnitude anomaly beneath the backarc spreading center is found at shallower depth (25-50 km) compared to the arc (50-100 km), consistent with melting depths estimated from the geochemistry of arc and backarc basalts (K. Kelley, pers. communication). The velocity and attenuation signature of the backarc spreading center is narrower than the corresponding anomaly found beneath the East Pacific Rise by the MELT experiment, perhaps implying a component of focused upwelling beneath the spreading center. The strong velocity and attenuation anomaly beneath the spreading center contrasts strongly with preliminary MT inversion results showing no conductivity anomaly in the

  20. Gakkel Ridge: A window to ancient asthenosphere

    Science.gov (United States)

    Snow, J.; Hellebrand, E.; Dick, H.; Liu, C.; Stracke, A.

    2008-12-01

    We are accustomed to thinking of the ambient mantle as being a well-stirred reservoir, which contains at most regions of stored subducted slabs and "plums" containing lithophile trace element enrichments. What is forgotten in all of this is that the main process of formation of heterogeneities is a negative one - generating 10x more depleted mantle at any given moment than it does oceanic crust. Because the volume of lithosphere subducted over Earth history is so large, it has always been assumed that the process of subduction and convective mixing re-homogenizes the depleted and enriched reservoirs about as fast as it produces them. What if it doesn't? Our primary means of studying mantle heterogeneity however is basalts. Direct study of the mantle entails observations on xenoliths, ophiolites and orogenic lherzolites, and abyssal peridotites. The latter have the inherent problems of being melting residues, associated with fracture zones, are highly serpentinized and rare. The arctic ridge system gives us a unique perspective on the mantle, and samples we have recovered there are relatively free from these problems. Due to the slow spreading rate, which apparently severely limits the melt productivity, the thickest crust in the Arctic ridge system is approximately "normal". The most common crust is about half thickness and there are large expanses with no crust at all, in the sense of Hess, 1962, exposing mantle peridotite in the floor of extensive rift zones. We have shown Os isotopic evidence for the survival of ancient depletion signatures in Gakkel abyssal peridotites that apparently were not destroyed by subduction, convective stirring or resetting during magma genesis (Liu, et al., 2008). Additionally, preliminary Nd isotopic evidence suggests at least a 400Ma intact prehistory for these samples. Apparently, the low melt productivity on Gakkel Ridge has allowed the Gakkel mantle rocks to escape significant resetting due to melt interaction. This implies a

  1. Application of high-resolution melting analysis for authenticity testing of valuable Dendrobium commercial products.

    Science.gov (United States)

    Dong, Xiaoman; Jiang, Chao; Yuan, Yuan; Peng, Daiyin; Luo, Yuqin; Zhao, Yuyang; Huang, Luqi

    2018-01-01

    The accurate identification of botanical origin in commercial products is important to ensure food authenticity and safety for consumers. The Dendrobium species have long been commercialised as functional food supplements and herbal medicines in Asia. Three valuable Dendrobium species, namely Dendrobium officinale, D. huoshanense and D. moniliforme, are often mutually adulterated in trade products in pursuit of higher profit. In this paper, a rapid and reliable semi-quantitative method for identifying the botanical origin of Dendrobium products in terminal markets was developed using high-resolution melting (HRM) analysis with specific primer pairs to target the trnL-F region. The HRM analysis method detected amounts of D. moniliforme adulterants as low as 1% in D. huoshanense or D. officinale products. The results have demonstrated that HRM analysis is a fast and effective tool for the differentiation of these Dendrobium species both for their authenticity as well as for the semi-quantitative determination of the purity of their processed products. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  2. Evolution of spreading rate and H2 production by serpentinization at mid-ocean ridges from 200 Ma to Present

    Science.gov (United States)

    Andreani, M.; García del Real, P.; Daniel, I.; Wright, N.; Coltice, N.

    2017-12-01

    Mid-oceanic ridge (MOR) spreading rate spatially varies today from 20 to 200 mm/yr and geological records attest of important temporal variations, at least during the past 200 My. The spreading rate has a direct impact on the mechanisms accomodating extension (magmatic vs tectonic), hence on the nature of the rocks forming the oceanic lithosphere. The latter is composed of variable amount of magmatic and mantle rocks, that dominate at fast and (ultra-) slow spreading ridges, respectively. Serpentinization of mantle rocks contributes to global fluxes and notably to those of hydrogen and carbon by providing a pathways for dihydrogen (H2) production, carbone storage by mineralization, and carbon reduction to CH4 and possibly complex organic compounds. Quantification of the global chemical impact of serpentinization through geological time requires a coupling of geochemical parameters with plate-tectonic reconstructions. Here we quantify serpentinization extent and concurrent H2 production at MOR from the Jurassic (200 Ma) to present day (0 Ma). We coupled mean values of relevant petro-chemical parameters such as the proportion of mantle rocks, initial iron in olivine, iron redox state in serpentinites, % of serpentinization to high-resolution models of plate motion within the GPlates infrastructure to estimate the lengths in 1 Myr intervals for the global MOR plate boundary (spreading and transform components), and spreading ridges as a function of their rate. The model sensitivity to selected parameters has been tested. The results show that fragmentation of Pangea resulted in elevated H2 rates (>1012 to 1013 mol/yr) starting at 160 Ma compared to Late Mesozoic (<160 Ma) rates (<1011-1012 mol/yr). From 160 Ma to present, the coupled opening of the Atlantic and Indian oceans as well as the variation in spreading rates maintained H2 generation in the 1012 mol/yr level, but with significant excursions mainly related to the length of ultra-slow spreading segments. For

  3. Status of stable isotope enrichment, products, and services at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Aaron, W.S.; Tracy, J.G.; Collins, E.D.

    1997-01-01

    The Oak Ridge national laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 y. Very significant changes have occurred in this effort over the past several years, and, while many of these changes have had a negative impact on the availability of enriched isotopes, more recent developments are actually improving the situation for both the users and the producers of enriched isotopes. ORNL is still a major producer and distributor of radioisotopes, but future isotope enrichment operations to be conducted at the isotope enrichment facility (IEF)fwill be limited to stable isotopes. Among the positive changes in the enriched stable isotope area are a well-functioning, long-term contract program, which offers stability and pricing advantages; the resumption of calutron operations; the adoption of prorated conversion charges, which greatly improves the pricing of isotopes to small users; ISO 9002 registration of the IEF's quality management system; and a much more customer-oriented business philosophy. Efforts are also being made to restore and improve upon the extensive chemical and physical form processing capablities that once existed in the enriched stable isotope program. Innovative ideas are being pursued in both technical and administrative areas to encourage the beneficial use of enriched stable isotopes and the development of related technologies. (orig.)

  4. Status of stable isotope enrichment, products, and services at the Oak Ridge National Laboratory

    Science.gov (United States)

    Scott Aaron, W.; Tracy, Joe G.; Collins, Emory D.

    1997-02-01

    The Oak Ridge National Laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 y. Very significant changes have occurred in this effort over the past several years, and, while many of these changes have had a negative impact on the availability of enriched isotopes, more recent developments are actually improving the situation for both the users and the producers of enriched isotopes. ORNL is still a major producer and distributor of radioisotopes, but future isotope enrichment operations to be conducted at the Isotope Enrichment Facility (IEF) will be limited to stable isotopes. Among the positive changes in the enriched stable isotope area are a well-functioning, long-term contract program, which offers stability and pricing advantages; the resumption of calutron operations; the adoption of prorated conversion charges, which greatly improves the pricing of isotopes to small users; ISO 9002 registration of the IEF's quality management system; and a much more customer-oriented business philosophy. Efforts are also being made to restore and improve upon the extensive chemical and physical form processing capablities that once existed in the enriched stable isotope program. Innovative ideas are being pursued in both technical and administrative areas to encourage the beneficial use of enriched stable isotopes and the development of related technologies.

  5. Status of stable isotope enrichment, products, and services at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Aaron, W.S.; Tracy, J.G.; Collins, E.D.

    1996-01-01

    The Oak Ridge National Laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 years. Very significant changes have occurred in this effort over the past several years, and, while many of these changes have had a negative impact on the availability of enriched isotopes, more recent developments are actually improving the situation for both the users and the producers of enriched isotopes. ORNL is still a major producer and distributor of radioisotopes, but future isotope enrichment operations conducted at the Isotope Enrichment Facility (IEF) will be limited to stable isotopes. Among the positive changes in the enriched stable isotope area are a well-functioning, long-term contract program, which offers stability and pricing advantages; the resumption of calutron operations; the adoption of prorated conversion charges, which greatly improves the pricing of isotopes to small users; SIO 9002 registration of the IEF's quality management system; and a much more customer-oriented business philosophy. Efforts are also being made to restore and improve upon the extensive chemical and physical form processing capabilities that once existed in the enriched stable isotope program. Innovative ideas are being pursued in both technical and administrative areas to encourage the beneficial use of enriched stable isotopes and the development of related technologies

  6. Prediction and Control of Selective Laser Melting Product Microstructure, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Despite the rapid commercialization of additive manufacturing technology such as selective laser melting, SLM, there are gaps in models for material microstructure...

  7. Ice melt influence on summertime net community production along the Western Antarctic Peninsula

    Science.gov (United States)

    Eveleth, R.; Cassar, N.; Sherrell, R. M.; Ducklow, H.; Meredith, M. P.; Venables, H. J.; Lin, Y.; Li, Z.

    2017-05-01

    The Western Antarctic Peninsula (WAP) is a highly productive marine environment that is undergoing rapid change, with consequences for productivity and total ecosystem carbon cycling. We present continuous underway O2/Ar estimates of net community production (NCPO2Ar) in austral summer 2012, 2013 and 2014 at sub-kilometer horizontal resolution within the Palmer Long-Term Ecological Research (Pal-LTER) grid region of the WAP. Substantial spatial variability is observed with NCPO2Ar ranging from 0 to 790 mmol O2 m-2 d-1 and considerable interannual variability with mean values in the grid region of 54.4±48.5, 44.6±40.5, and 85.6±75.9 mmol O2 m-2 d-1 in 2012, 2013 and 2014 respectively. Based on a strong correlation (r2=0.83) between residence time integrated NCPO2Ar and NCPDIC derived from seasonal DIC drawdown, we find the observed NCPO2Ar spatial and interannual variability to be consistent with the December-January NCPDIC magnitude. Seeking to explain the mechanistic drivers of NCP in the WAP, we observe a linear relationship between NCPO2Ar and meteoric water content derived from δ18O and salinity. This correlation may be due to Fe supply from glacial melt and/or strengthening of stratification and relief of light limitation. Elevated surface Fe availability, as indicated by Fv/Fm and measurements of surface water dissolved Fe and Mn (a rough proxy for recent potential Fe availability), and shallower, more stable mixed layers are present where meteoric water and/or sea ice melt is high near the coast. Light limitation is evident in the WAP when mixed layer depths are greater than 40 m. Additionally we document hotspots of NCP associated with submarine canyons along the WAP. While it is difficult to predict how the physical-biological system might evolve under changing climatic conditions, it is evident that NCP, and potentially carbon flux out of the mixed layer, along the WAP will be sensitive to shifts in meltwater input and timing.

  8. Sheet production apparatus for removing a crystalline sheet from the surface of a melt using gas jets located above and below the crystalline sheet

    Energy Technology Data Exchange (ETDEWEB)

    Kellerman, Peter L.; Thronson, Gregory D.

    2017-06-14

    In one embodiment, a sheet production apparatus comprises a vessel configured to hold a melt of a material. A cooling plate is disposed proximate the melt and is configured to form a sheet of the material on the melt. A first gas jet is configured to direct a gas toward an edge of the vessel. A sheet of a material is translated horizontally on a surface of the melt and the sheet is removed from the melt. The first gas jet may be directed at the meniscus and may stabilize this meniscus or increase local pressure within the meniscus.

  9. A novel process for production of spherical PBT powders and their processing behavior during laser beam melting

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Jochen, E-mail: jochen.schmidt@fau.de; Sachs, Marius; Fanselow, Stephanie; Wirth, Karl-Ernst; Peukert, Wolfgang [Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Particle Technology, Cauerstr. 4, D-91058 Erlangen (Germany); Zhao, Meng; Wudy, Katrin; Drexler, Maximilian; Drummer, Dietmar [Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Polymer Technology, Am Weichselgarten 9, D-91058 Erlangen (Germany)

    2016-03-09

    Additive manufacturing processes like laser beam melting of polymers are established for production of prototypes and individualized parts. The transfer to other areas of application and to serial production is currently hindered by the limited availability of polymer powders with good processability. Within this contribution a novel process route for the production of spherical polymer micron-sized particles of good flowability has been established and applied to produce polybutylene terephthalate (PBT) powders. Moreover, the applicability of the PBT powders in selective laser beam melting and the dependencies of process parameters on device properties will be outlined. First, polymer micro particles are produced by a novel wet grinding method. To improve the flowability the produced particles the particle shape is optimized by rounding in a heated downer reactor. A further improvement of flowability of the cohesive spherical PBT particles is realized by dry coating. An improvement of flowability by a factor of about 5 is achieved by subsequent rounding of the comminution product and dry-coating as proven by tensile strength measurements of the powders. The produced PBT powders were characterized with respect to their processability. Therefore thermal, rheological, optical and bulk properties were analyzed. Based on these investigations a range of processing parameters was derived. Parameter studies on thin layers, produced in a selective laser melting system, were conducted. Hence appropriate parameters for processing the PBT powders by laser beam melting, like building chamber temperature, scan speed and laser power have been identified.

  10. A novel process for production of spherical PBT powders and their processing behavior during laser beam melting

    International Nuclear Information System (INIS)

    Schmidt, Jochen; Sachs, Marius; Fanselow, Stephanie; Wirth, Karl-Ernst; Peukert, Wolfgang; Zhao, Meng; Wudy, Katrin; Drexler, Maximilian; Drummer, Dietmar

    2016-01-01

    Additive manufacturing processes like laser beam melting of polymers are established for production of prototypes and individualized parts. The transfer to other areas of application and to serial production is currently hindered by the limited availability of polymer powders with good processability. Within this contribution a novel process route for the production of spherical polymer micron-sized particles of good flowability has been established and applied to produce polybutylene terephthalate (PBT) powders. Moreover, the applicability of the PBT powders in selective laser beam melting and the dependencies of process parameters on device properties will be outlined. First, polymer micro particles are produced by a novel wet grinding method. To improve the flowability the produced particles the particle shape is optimized by rounding in a heated downer reactor. A further improvement of flowability of the cohesive spherical PBT particles is realized by dry coating. An improvement of flowability by a factor of about 5 is achieved by subsequent rounding of the comminution product and dry-coating as proven by tensile strength measurements of the powders. The produced PBT powders were characterized with respect to their processability. Therefore thermal, rheological, optical and bulk properties were analyzed. Based on these investigations a range of processing parameters was derived. Parameter studies on thin layers, produced in a selective laser melting system, were conducted. Hence appropriate parameters for processing the PBT powders by laser beam melting, like building chamber temperature, scan speed and laser power have been identified.

  11. Results of out-of-pile experiments to investigate the possibilities of cooling a core melt with internal heat production

    International Nuclear Information System (INIS)

    Fieg, G.

    1976-01-01

    After serious hypothetical reactor accidents, melted core materials with internal heat production can occur in large quantities. A retention of these molten core masses within the containment must be ensured. The knowledge of the heat transport from volume-heated layers is necessary to clarify this matter. (orig./LH) [de

  12. Iron from melting glaciers fuels phytoplankton blooms in the Amundsen Sea (Southern Ocean): Phytoplankton characteristics and productivity

    NARCIS (Netherlands)

    Alderkamp, A.C.; Mills, M.M.; van Dijken, G.L.; Laan, P.; Thuróczy, C.-E.; Gerringa, L.J.A.; de Baar, H.J.W.; Payne, C.D.; Visser, R.J.W.; Buma, A.G.J.; Arrigo, K.R.

    2012-01-01

    The phytoplankton community composition and productivity in waters of the Amundsen Sea and surrounding sea ice zone were characterized with respect to iron (Fe) input from melting glaciers. High Fe input from glaciers such as the Pine Island Glacier, and the Dotson and Crosson ice shelves resulted

  13. Development of continuous glass melting for production of Nd-doped phosphate glasses for the NIF and LMJ laser system

    International Nuclear Information System (INIS)

    Campbell, J. H.; Ficini-Dorn, G.; Hawley-Fedder, R.; McLean, M. J.; Suratwala, T.; Trombert, J. H.

    1998-01-01

    The NIF and LMJ laser systems require about 3380 and 4752 Nd-doped laser glass slabs, respectively. Continuous laser glass melting and forming will be used for the first time to manufacture these slabs. Two vendors have been chosen to produce the glass: Hoya Corporation and Schott Glass Technologies. The laser glass melting systems that each of these two vendors have designed, built and tested are arguably the most advanced in the world. Production of the laser glass will begin on a pilot scale in the fall of 1999

  14. Effects of tied ridges and mulch on barley (Hordeum vulgare) rainwater use efficiency and production in Northern Ethiopia

    NARCIS (Netherlands)

    Araya, A.; Stroosnijder, L.

    2010-01-01

    Two alternative in situ area rainwater conservation practices (tied ridging and mulching) were evaluated for four seasons (2004, 2007, 2008 and 2009) at an experimental station in Mekelle, Ethiopia. The objectives were to evaluate the performance of barley as influenced by mulch and tied ridge and

  15. Active packaging for topical cosmetic/drug products: a hot-melt extruded preservative delivery device.

    Science.gov (United States)

    Zema, L; Sangalli, M E; Maroni, A; Foppoli, A; Bettero, A; Gazzaniga, A

    2010-06-01

    A delivery device intended for the prolonged release of antimicrobial agents, able to enhance the stability profile of liquid/semi-solid cosmetic/pharmaceutical products for topical application, was proposed in the present study. With the aid of a simulation program based on compartment models, the relevant kinetic and formulation parameters were defined using dehydroacetic acid sodium salt (DHA.Na, Prevan) as the model preservative. Indeed, the overall DHA.Na degradation rate is increased in the presence of formaldehyde releasers that are often employed as co-preservatives. Inert matrices (3 g weight and 18 mm diameter) based on high-density polyethylene (HDPE), possibly consistent with the design of an active packaging meant for preservative delivery, were prepared by hot-melt extrusion. Units with satisfactory physical-technological properties could be obtained up to 50%w/w loads of antimicrobial agent. In an attempt to modify the relevant Fickian release profiles by varying the area exposed to the medium, matrix systems coated with an impermeable film except for one base (CMs) or for the inner surface of a central drilled hole (PCMs) were investigated. On the basis of the n exponent of power equation and the outcome of linear fitting, PCMs were proven able to yield the zero-order release behaviour needed to ensure constant DHA.Na levels over a predetermined time period, as indicated by the simulation process. Copyright 2010 Elsevier B.V. All rights reserved.

  16. Paleo-Productivity across the Paleocene-Eocene Thermal Maximum, Walvis Ridge Transect (ODP Sites 1262, 1263, and 1266)

    Science.gov (United States)

    Chun, C. O.; Delaney, M. L.; Zachos, J. C.

    2005-12-01

    Walvis Ridge transect (Ocean Drilling Program (ODP) Leg 208) provides the first high-resolution depth-transect of deep-sea sediments recovered from the south Atlantic across the P/E boundary. A geographically restricted depth transect (~ 2.2 km, water depths between 2500 and 4770 m) allows us to constrain the surface waters by assuming marine productivity conditions in the overlying water column are similar across all sites. The sediment record will reveal variations for processes that are water-depth dependent. We use the geochemical tracers; biogenic barium, phosphorus, calcium carbonate, and the redox sensitive trace elements manganese and uranium, to reconstruct nutrient burial, paleoproductivity, and bottom water redox chemistry across the Paleocene-Eocene Thermal Maximum (PETM). We calculate our concentrations on a calcium carbonate-free basis to account for dilution by non-carbonate sediments. Trace metal enrichment factors (EFs) are calculated relative to bulk crustal averages. We chose three sites from the depth transect: the shallowest (Site 1263, 2717 m water depth), an intermediate site (Site 1266, 3798 m water depth), and the deepest site (Site 1262, 4755 m water depth). We sampled each site at a sample resolution of ~ 1-2 kyr for 5 m.y. centered at 55 Ma. Uranium EFs at the shallow site exhibits values ~ 5 pre-event and drop to values near crustal averages during and after the carbon isotope excursion (CIE). No dramatic changes in U EFs across the P/E boundary are recorded at the deep and intermediate sites. Mn EFs range between 2.9 -8.6 prior to the event across all three sites, suggesting an oxygenated depositional environment. At the boundary, Mn EFs drop to crustal averages at all sites, then gradually return to pre-event values, indicating more reducing environments during the CIE, a possible explanation for the benthic extinction event (BEE) observed across this transect. Ba excess and reactive phosphorus exhibit decreased concentrations during

  17. Copepod distribution and production in a Mid-Atlantic Ridge archipelago

    Directory of Open Access Journals (Sweden)

    PEDRO A.M.C. MELO

    2014-12-01

    Full Text Available The Saint Peter and Saint Paul Archipelago (SPSPA are located close to the Equator in the Atlantic Ocean. The aim of this study was to assess the spatial variations in the copepod community abundance, and the biomass and production patterns of the three most abundant calanoid species in the SPSPA. Plankton samples were collected with a 300 µm mesh size net along four transects (north, east, south and west of the SPSPA, with four stations plotted in each transect. All transects exhibited a tendency toward a decrease in copepod density with increasing distance from the SPSPA, statistically proved in the North. Density varied from 3.33 to 182.18 ind.m−3, and differences were also found between the first perimeter (first circular distance band and the others. The total biomass varied from 15.25 to 524.50 10−3 mg C m−3 and production from 1.19 to 22.04 10−3 mg C m−3d−1. The biomass and production of Undinula vulgaris (Dana, 1849, Acrocalanus longicornis Giesbrecht, 1888 and Calocalanus pavo (Dana, 1849 showed differences between some transects. A trend of declining biodiversity and production with increasing distance from archipelago was observed, suggesting that even small features like the SPSPA can affect the copepod community in tropical oligotrophic oceanic areas.

  18. Analysis and evaluation of the ASTEC model basis on fission product and aerosol release phenomena from melts. 3. Technical report

    International Nuclear Information System (INIS)

    Agethen, K.; Koch, M.K.

    2016-04-01

    The present report is the 3 rd Technical Report within the research project ''ASMO'' founded by the German Federal Ministry for Economic Affairs and Energy (BMWi 1501433) and projected at the Chair of Energy Systems and Energy Economics (LEE) within the workgroup Reactor Simulation and Safety at the Ruhr-Universitaet Bochum (RUB). The focus in this report is set on the release of fission products and the contribution to the source term, which is formed in the late phase after failure of the reactor pressure vessel during MCCI. By comparing the RUB simulation results including the fission product release rates with further simulations of GRS and VEIKI it can be indicated that the simulations have a high sensitivity in respect to the melting point temperature. It can be noted that the release rates are underestimated for most fission product species with the current model. Especially semi-volatile fission products and the lanthanum release is underestimated by several orders of magnitude. Based on the ACE experiment L2, advanced considerations are presented concerning the melt temperature, the gas temperature, the segregation and a varied melt configuration. Furthermore, the influence of the gas velocity is investigated. This variation of the gas velocity causes an underestimation of the release rates compared to the RUB base calculation. A model extension to oxidic species for lanthanum and ruthenium shows a significant improvement of the simulation results. In addition, the MEDICIS module has been enhanced to document the currently existing species, are displayed in a *.ist-file. This expansion shows inconsistencies between the melt composition and the fission product composition. Based on these results, there are still some difficulties regarding the release of fission products in the MEDICIS module and the interaction with the material data base (MOB) which needs further investigation.

  19. Geochemistry of axial seamount lavas: Magmatic relationship between the Cobb Hotspot and the Juan de Fuca Ridge

    Science.gov (United States)

    Rhodes, J. M.; Morgan, C.; Liias, R. A.

    1990-08-01

    Axial Seamount, located along the central portion of the Juan de Fuca Ridge axis and at the eastern end of the Cobb-Eickelberg Seamount Chain, is the current center of the Cobb Hotspot. The Axial Seamount lavas are transitional between N-type and E-type mid-ocean ridge basalt (MORB), characteristics that they share with lavas along the rest of the Juan de Fuca Ridge. There are, however, subtle, but distinct, differences between the seamount lavas and those of the adjoining ridge segments. These include higher Na2O, CaO, and Sr at a given MgO content and lower silica saturation in the seamount lavas as compared with the ridge lavas. Lava chemistry and bathymetry indicate that Axial Seamount is a discrete volcanic unit, with a more productive shallow magmatic plumbing system separate from the adjacent ridge segments. These high magma supply rates have sustained a continuously replenished, steady state magma reservoir that has erupted remarkably homogeneous lavas over a long time period. Despite this classic association of spreading center and hotspot volcanic activity, there is no evidence in the lavas for geochemical or isotopic enrichment typical of hotspot or mantle plume activity. The differences in composition between the Axial Seamount lavas and the Juan de Fuca Ridge lavas are attributed to melting processes rather than to any fundamental differences in their mantle source compositions. The higher magma production rates, higher Sr, and lower silica saturation in the seamount lavas relative to the ridge lavas are thought to be a consequence of melt initiation at greater depths. The melting column producing the seamount lavas is thought to be initiated in the stability field of spinel peridotite, whereas the ridge lavas are produced from a melting column initiated at shallower levels, possibly within or close to the stability field of plagioclase peridotite. Implicit in this interpretation is the conclusion that the Juan de Fuca Ridge lavas, and by analogy most

  20. Glacial modulation of mid-ocean ridge magmatism and anomalous Pacific Antarctic Ridge volcanism during Termination II

    Science.gov (United States)

    Asimow, P. D.; Lewis, M.; Lund, D. C.; Seeley, E.; McCart, S.; Mudahy, A.

    2017-12-01

    Glacially-driven sea level rise and fall may modulate submarine volcanism by superposing pressure changes on the tectonic decompression that causes melt production in the mantle below mid-ocean ridges. A number of recent studies have considered whether this effect is recorded in the periodicity of ridge flank bathymetry (Tolstoy, 2015; Crowley et al., 2015) but interpretation of the bathymetric data remains controversial (Goff, 2016; Olive et al., 2016). We have pursued an independent approach using hydrothermal metals in well-dated near-ridge sediment cores. Along the full length of the East Pacific Rise, in areas of the ocean with widely variable biologic productivity, there are large and consistent rises in Fe, Mn, and As concentrations during the last two glacial terminations. We interpret these cores as records of excess hydrothermal flux due to delayed delivery to the axis of excess melt generated by the preceding falls in sea level. Here we discuss the potentially related discovery, in a core near the Pacific Antarctic Ridge (PAR), of a 10 cm thick layer of basaltic ash shards up to 250 mm in size, coincident with the penultimate deglaciation (Termination II). Although the site was 8 km off-axis at the time, the glasses have major element, volatile, and trace element composition consistent with more evolved members of the axial MORB suite from the nearby ridge axis. Their morphologies are typical of pyroclastic deposits created by explosive submarine volcanism (Clague et al., 2009). We propose that a period of low magmatic flux following a sea-level rise caused cooling of crustal magmatic systems, more advanced fractionation in the axial magma chamber, and increases in viscosity and volatile concentration. We hypothesize subsequent arrival of high magmatic flux during Termination II then reactivated the system and triggered an unusually vigorous series of explosive eruptions along this segment of the PAR. Ash layers recording large eruptions such as this one

  1. Reaction products and corrosion of molybdenum electrode in glass melt containing antimony oxides and sodium sulfate

    Czech Academy of Sciences Publication Activity Database

    Matěj, J.; Langrová, Anna

    2012-01-01

    Roč. 56, č. 3 (2012), s. 280-285 ISSN 0862-5468 Institutional support: RVO:67985831 Keywords : antimony oxides * corrosion * glass melt * Molybdenum electrode * sulfate Subject RIV: DD - Geochemistry Impact factor: 0.418, year: 2012 http://www.ceramics-silikaty.cz/2012/pdf/2012_03_280.pdf

  2. The Production of Methane, Hydrogen, and Organic Compounds in Ultramafic-Hosted Hydrothermal Vents of the Mid-Atlantic Ridge

    Science.gov (United States)

    Charlou, J.L.; Holm, N.G.; Mousis, O.

    2015-01-01

    Abstract Both hydrogen and methane are consistently discharged in large quantities in hydrothermal fluids issued from ultramafic-hosted hydrothermal fields discovered along the Mid-Atlantic Ridge. Considering the vast number of these fields discovered or inferred, hydrothermal fluxes represent a significant input of H2 and CH4 to the ocean. Although there are lines of evidence of their abiogenic formation from stable C and H isotope results, laboratory experiments, and thermodynamic data, neither their origin nor the reaction pathways generating these gases have been fully constrained yet. Organic compounds detected in the fluids may also be derived from abiotic reactions. Although thermodynamics are favorable and extensive experimental work has been done on Fischer-Tropsch-type reactions, for instance, nothing is clear yet about their origin and formation mechanism from actual data. Since chemolithotrophic microbial communities commonly colonize hydrothermal vents, biogenic and thermogenic processes are likely to contribute to the production of H2, CH4, and other organic compounds. There seems to be a consensus toward a mixed origin (both sources and processes) that is consistent with the ambiguous nature of the isotopic data. But the question that remains is, to what proportions? More systematic experiments as well as integrated geochemical approaches are needed to disentangle hydrothermal geochemistry. This understanding is of prime importance considering the implications of hydrothermal H2, CH4, and organic compounds for the ocean global budget, global cycles, and the origin of life. Key Words: Hydrogen—Methane—Organics—MAR—Abiotic synthesis—Serpentinization—Ultramafic-hosted hydrothermal vents. Astrobiology 15, 381–399. PMID:25984920

  3. Species identification in meat products: A new screening method based on high resolution melting analysis of cyt b gene.

    Science.gov (United States)

    Lopez-Oceja, A; Nuñez, C; Baeta, M; Gamarra, D; de Pancorbo, M M

    2017-12-15

    Meat adulteration by substitution with lower value products and/or mislabeling involves economic, health, quality and socio-religious issues. Therefore, identification and traceability of meat species has become an important subject to detect possible fraudulent practices. In the present study the development of a high resolution melt (HRM) screening method for the identification of eight common meat species is reported. Samples from Bos taurus, Ovis aries, Sus scrofa domestica, Equus caballus, Oryctolagus cuniculus, Gallus gallus domesticus, Meleagris gallopavo and Coturnix coturnix were analyzed through the amplification of a 148 bp fragment from the cyt b gene with a universal primer pair in HRM analyses. Melting profiles from each species, as well as from several DNA mixtures of these species and blind samples, allowed a successful species differentiation. The results demonstrated that the HRM method here proposed is a fast, reliable, and low-cost screening technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Production of micron-sized polymer particles for additive manufacturing by melt emulsification

    Energy Technology Data Exchange (ETDEWEB)

    Fanselow, Stephanie; Schmidt, Jochen; Wirth, Karl-Ernst; Peukert, Wolfgang, E-mail: Wolfgang.Peukert@fau.de [Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Cauerstrasse 4, 91058 Erlangen (Germany)

    2016-03-09

    Melt emulsification is an advanced top-down approach that permits to produce spherical particles and thus widens the availability of polymer feed materials for additive manufacturing. In the process the polymer is molten in a continuous phase and droplet breakup is realized in a rotor-stator-device. The stabilization of the newly formed surfaces is quite challenging. Therefore, a new method to identify an appropriate emulsifier by measuring the interfacial tension between the polymer and continuous phase using a high pressure / high temperature cell is presented. The obtained powders are characterized by scanning electron microscopy (SEM) and by a Zimmermann tensile strength tester to determine the powder flowability. The processability of the polymer powders for additive manufacturing is investigated and demonstrated by building single layers by laser beam melting.

  5. The use of radiation for the production of high melt strength polypropylene

    International Nuclear Information System (INIS)

    Lugao, A.B.; Cardoso, E.C.L.; Hustzler, B.; Tokumoto, S.; Mendes, A.N.F.

    2001-01-01

    PP suffers from low melt strength, i.e., the melted PP does not exhibits an increase in resistance to stretching during elongation. It is well known that the melt-strength properties of a polymer increase with molecular weight and with long chain branching due to the increase in the entanglement level (high melt strength PP-HMSPP). In spite of been the most fast growing polymeric commodity nowadays those new grades of PP and its development have been barely studied and its general chemical characterization have been even less studied with few exceptions. HMSPP as proposed by Montell patents are produced by low temperature and low dose irradiation of high molecular weight isotatica PP in N 2 atmosphere. So the well-known reactions would be mostly degradation and crosslinking. Degradation however is supposed to be the first and more intense reaction a the initial steps as already shown. So, according to Montell patents, another reaction is likely to occur, branching or T links competing with crosslinkings or H links. Radical are likely to decay very fast in amorphous phase, but under annealing the radicals entrapped in the crystal phase is likely to move to the boundary and react. The group of professor Silverman has already hypothesized in T links formation and also studied the radical decay of PP. It is easy to understand the difficulties in differentiate Hs from Ts links and even these links if in very small amount from the bulk or from virgin polymer, as the Ts links and even these links if in very small amount from the bulk or from virgin polymer, as the chemical groups and links are chemically speaking essentially the same

  6. Mechanism of chlorination of some actinide and fission product phosphates and tungstates in chloride melts

    International Nuclear Information System (INIS)

    Kryukova, A.I.; Chernikov, A.A.; Skiba, O.V.; Kazantsev, G.N.

    1989-01-01

    Results of kinetic studies on the chlorination of crystalline phosphates and tungstates of uranium, cerium, zirconium, and plutonium by gaseous carbon tetrachloride in melts of alkali metal chlorides at 973-1073 degree K are analyzed. A mathematical model of the process is proposed. Analysis of regression models allowed solution of the problem by statistical evaluation of the effective factors and prediction within the limits of the factors studied of the optimal conditions for the process

  7. Transitions in axial morphology along the Southeast Indian Ridge

    Science.gov (United States)

    Ma, Ying; Cochran, James R.

    1996-07-01

    a distance of 800 km. In addition, the ridge continues to become shallower away from Amsterdam Island toward the transition to an axial high at 82°E, 350 km to the east of the ASP. The Kerguelen hotspot appears to exert a major influence on the morphology of the SEIR by feeding asthenospheric material to the ridge axis. A long, narrow finger-like gravity high extends ENE away from the Kerguelen Plateau for a distance of 500 km. Shipboard data show that the gravity high results from a large volcanic ridge. The ridge appears analogous to the Rodriguez Ridge extending from the Reunion hotspot toward the Central Indian Ridge. A series of lower and broader lineated gravity highs extend from the volcanic ridge toward the SEIR in the ridge segment between the 81°E and 85°E transforms, which is the westernmost segment with an axial high. The only region of significant off-ridge seismicity on the Antarctic flank of the SEIR is a diffuse band of epicenters extending from Kerguelen to the SEIR within the segment between the 81°E and 85°E fracture zones. The along-axis gradient in depth from 86°E to the AAD and the transitions in axial morphology at 104°E and 114°E most likely reflect along-axis variations in mantle temperature and melt production rate due to distance from the Kerguelen hotspot and the influence of the AAD.

  8. Sensitivity of seafloor bathymetry to climate-driven fluctuations in mid-ocean ridge magma supply.

    Science.gov (United States)

    Olive, J-A; Behn, M D; Ito, G; Buck, W R; Escartín, J; Howell, S

    2015-10-16

    Recent studies have proposed that the bathymetric fabric of the seafloor formed at mid-ocean ridges records rapid (23,000 to 100,000 years) fluctuations in ridge magma supply caused by sealevel changes that modulate melt production in the underlying mantle. Using quantitative models of faulting and magma emplacement, we demonstrate that, in fact, seafloor-shaping processes act as a low-pass filter on variations in magma supply, strongly damping fluctuations shorter than about 100,000 years. We show that the systematic decrease in dominant seafloor wavelengths with increasing spreading rate is best explained by a model of fault growth and abandonment under a steady magma input. This provides a robust framework for deciphering the footprint of mantle melting in the fabric of abyssal hills, the most common topographic feature on Earth. Copyright © 2015, American Association for the Advancement of Science.

  9. Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Clean Steel Casting Production

    Energy Technology Data Exchange (ETDEWEB)

    Kuyucak, Selcuk [CanmetMATERIALS; Li, Delin [CanmetMATERIALS

    2013-12-31

    Inclusions in steel castings can cause rework, scrap, poor machining, and reduced casting performance, which can obviously result in excess energy consumption. Significant progress in understanding inclusion source, formation and control has been made. Inclusions can be defined as non-metallic materials such as refractory, sand, slag, or coatings, embedded in a metallic matrix. This research project has focused on the mold filling aspects to examine the effects of pouring methods and gating designs on the steel casting cleanliness through water modeling, computer modeling, and melting/casting experiments. Early in the research project, comprehensive studies of bottom-pouring water modeling and low-alloy steel casting experiments were completed. The extent of air entrainment in bottom-poured large castings was demonstrated by water modeling. Current gating systems are designed to prevent air aspiration. However, air entrainment is equally harmful and no prevention measures are in current practice. In this study, new basin designs included a basin dam, submerged nozzle, and nozzle extension. The entrained air and inclusions from the gating system were significantly reduced using the new basin method. Near the end of the project, there has been close collaboration with Wescast Industries Inc., a company manufacturing automotive exhaust components. Both computer modeling using Magma software and melting/casting experiments on thin wall turbo-housing stainless steel castings were completed in this short period of time. Six gating designs were created, including the current gating on the pattern, non-pressurized, partially pressurized, naturally pressurized, naturally pressurized without filter, and radial choke gating without filter, for Magma modeling. The melt filling velocity and temperature were determined from the modeling. Based on the simulation results, three gating designs were chosen for further melting and casting experiments on the same casting pattern using

  10. Ridge sowing of sunflower (Helianthus annuus L.) in a minimum till system improves the productivity, oil quality, and profitability on a sandy loam soil under an arid climate.

    Science.gov (United States)

    Sher, Ahmad; Suleman, Muhammad; Qayyum, Abdul; Sattar, Abdul; Wasaya, Allah; Ijaz, Muhammad; Nawaz, Ahmad

    2018-04-01

    Sunflower (Helianthus annuus L.) is a major oilseed crop grown for its edible oil across the globe including Pakistan. In Pakistan, the production of edible oil is less than the required quantity; the situation is being worsened with the increasing population. Thus, there is dire need to grow those sunflower genotypes which perform better under a given set of agronomic practices. In this 2-year study, we compared four sunflower genotypes, viz., Armoni, Kundi, Sinji, and S-278 for their yield potential, oil contents, fatty acid composition, and profitability under three sowing methods, viz., bed sowing, line sowing, and ridge sowing and two tillage system, viz., plow till and minimum till. Among the sunflower genotypes, the genotype Armoni produced the highest plant height, number of leaves, head diameter, 1000-achene weight, and achene yield; the oil contents and oleic acid were the highest in genotype Sinji. Among the sowing methods, the highest number of leaves per plant, head diameter, number of achenes per head, achene yield, and oil contents were recorded in ridge sowing. Among the tillage systems, the highest head diameter 16. 2 cm, 1000-achene weight (57.2 g), achene yield (1.8 t ha -1 ), oil contents (35.2%), and oleic acid (15.2%) were recorded in minimum till sunflower. The highest net benefits and benefit to cost ratio were recorded in minimum till ridge sown Armoni genotype. In conclusion, the genotype Armoni should be grown on ridges to achieve the highest achene yield, oil contents, and net profitability.

  11. Solid-assisted melt disintegration (SAMD), a novel technique for metal powder production

    International Nuclear Information System (INIS)

    Akhlaghi, F.; Esfandiari, H.

    2007-01-01

    A new process termed 'solid-assisted melt disintegration (SAMD)' has been developed for the preparation of aluminum alloy powder particles. The method consists of introducing and mixing a specified amount of as-received alumina particles (in the range of +700 to 500 μm) in A356 aluminum melt at the temperature of 715 deg. C. Melt disintegration occurs in 10 min by kinetic energy transfer from a rotating impeller (450 rpm) to the metal via the solid atomizing medium (alumina particles). The resulting mixture of aluminum droplets and alumina particles was cooled in air and screened through 300 μm sieve to separate alumina from solidified aluminum powder particles. A356 aluminum alloy was also gas atomized by using a free-fall atomizer operating by nitrogen gas at the pressure of 1.1 MPa and the sub-300 μm of the produced powder was used as a base of comparison. The SAMD produced powders of diameter above 53 μm were mostly spherical while powders less than 53 μm showed various elongated shapes. No evidence was found for satelliting of small particles on to large ones or agglomerated particles. While gas atomized particles in the +53 μm sieve size range showed some signs of porosity, the SAMD particles were dense and did not show any signs of internal porosity in any of the sieve fractions investigated. Comparison of the microstructure of the SAMD and gas-atomized powders revealed that for the same size powder of A356 alloy, the former exhibited a coarser microstructure as a result of a slower cooling rate

  12. Active spreading processes at ultraslow mid-ocean ridges: The 1999-2001 seismo-volcanic episode at 85°E Gakkel ridge, Arctic Ocean

    Science.gov (United States)

    Schlindwein, Vera; Riedel, Carsten; Korger, Edith; Läderach, Christine

    2010-05-01

    The rate of magma and crustal production at mid-ocean ridges is thought to decrease with decreasing spreading rate. At ultraslow spreading rates below 10-20 mm/y full rate, heat loss by conduction greatly reduces melt production with less melt produced at increasingly greater depths. Gakkel Ridge, the actively spreading mid-ocean ridge in the Arctic Ocean, opens at rates of 14 mm/y in the west decreasing to less than 6 mm/y at its eastern termination and demonstrates that magma production is not only a function of spreading rate. Whereas amagmatic spreading takes place at rates of about 12-10 mm/y, focussed melt production occurs at even lower spreading rates in long-lived discrete volcanic centres. One such centre is the 85°E volcanic complex at eastern Gakkel ridge where in 1999 a teleseismically recorded earthquake swarm consisting of more than 250 earthquakes over 9 months signalled the onset of an active spreading episode. The earthquake swarm is believed to be associated with volcanic activity although no concurrent lava effusion was found. We analysed the teleseismic earthquake swarm together with visual observation and microseismic data recorded at this site in 2001 and 2007 and noted the following characteristics which may be indicative for volcanic spreading events at the still poorly explored ultraslow spreading ridges: - unusual duration: The 1999 earthquake swarm lasted over 9 months rather than a few weeks as observed on faster spreading ridges. In addition, in 2001 seismoacoustic sounds which we interpret as gas discharge in Strombolian eruptions and a giant event plume maintained over more than one year indicate waxing and waning volcanic activity since 1999. - unusual strength: The earthquake swarm was detected at teleseismic distances of more than 1000 km and included 11 events with a magnitude >5. No other confirmed mid-ocean ridge eruption released a comparable seismic moment. Rather than focussing in a narrow area or showing pronounced

  13. Hybrid analysis (barcode-high resolution melting) for authentication of Thai herbal products, Andrographis paniculata (Burm.f.) Wall.ex Nees.

    Science.gov (United States)

    Osathanunkul, Maslin; Suwannapoom, Chatmongkon; Khamyong, Nuttaluck; Pintakum, Danupol; Lamphun, Santisuk Na; Triwitayakorn, Kanokporn; Osathanunkul, Kitisak; Madesis, Panagiotis

    2016-01-01

    Andrographis paniculata Nees is a medicinal plant with multiple pharmacological properties. It has been used over many centuries as a household remedy. A. paniculata products sold on the markets are in processed forms so it is difficult to authenticate. Therefore buying the herbal products poses a high-risk of acquiring counterfeited, substituted and/or adulterated products. Due to these issues, a reliable method to authenticate products is needed. High resolution melting analysis coupled with DNA barcoding (Bar-HRM) was applied to detect adulteration in commercial herbal products. The rbcL barcode was selected to use in primers design for HRM analysis to produce standard melting profile of A. paniculata species. DNA of the tested commercial products was isolated and their melting profiles were then generated and compared with the standard A. paniculata. The melting profiles of the rbcL amplicons of the three closely related herbal species (A. paniculata, Acanthus ebracteatus and Rhinacanthus nasutus) are clearly separated so that they can be distinguished by the developed method. The method was then used to authenticate commercial herbal products. HRM curves of all 10 samples tested are similar to A. paniculata which indicated that all tested products were contained the correct species as labeled. The method described in this study has been proved to be useful in aiding identification and/or authenticating A. paniculata. This Bar-HRM analysis has allowed us easily to determine the A. paniculata species in herbal products on the markets even they are in processed forms. We propose the use of DNA barcoding combined with High Resolution Melting analysis for authenticating of Andrographis paniculata products.The developed method can be used regardless of the type of the DNA template (fresh or dried tissue, leaf, and stem).rbcL region was chosen for the analysis and work well with our samplesWe can easily determine the A. paniculata species in herbal products tested

  14. Uranium-thorium disequilibria and partitioning on melting of garnet peridotite

    International Nuclear Information System (INIS)

    Beattie, P.

    1993-01-01

    The abundances of isotopes in the 238 U decay series can be used as both tracers and chronometers of magmatic processes. In the subsolidus asthenosphere, the activity of each daughter isotope (defined as the product of its concentration and decay constant, and denoted by parentheses) is assumed to be equal to that of its parent. By contrast, ( 230 Th/ 238 U) is greater than unity in most recent mid-ocean-ridge and ocean-island basalts, implying that thorium is more incompatible (that is, it is partitioned into the melt phase more strongly) than uranium. Melting of spinel peridotite cannot produce the ( 230 Th) excesses, because measured partition coefficients for pyroxenes and olivine demonstrate that uranium is more incompatible than thorium for this rock. Here I report garnet-melt partitioning data which show that for this mineral-melt pair thorium does behave more incompatibility than uranium, thus supporting the suggestion that mid-ocean-ridge basalts (MORB) are produced by melting initiated at depths where garnet is stable. Using these data, I show that the observed ( 230 Th/ 238 U) ratios of MORB and most ocean-island basalts can be explained by slow, near-fractional melting initiated in the garnet stability field. (author)

  15. Processing and characterization of Al–Cu–Li alloy AA2195 undergoing scale up production through the vacuum induction melting technique

    Energy Technology Data Exchange (ETDEWEB)

    Nayan, Niraj, E-mail: metnayan@gmail.com [Materials and Mechanical Entity, Vikram Sarabhai Space Centre, Trivandrum 695022 (India); Murty, S.V.S. Narayana; Jha, Abhay K.; Pant, Bhanu; Sharma, S.C.; George, Koshy M. [Materials and Mechanical Entity, Vikram Sarabhai Space Centre, Trivandrum 695022 (India); Sastry, G.V.S. [Department of Metallurgical Engineering, Institute of Technology, Banaras Hindu University, Varanasi (India)

    2013-08-01

    The inherent properties of lithium, such as high reactivity and toxicity, relatively low density, low melting point, along with its high cost requires a special technological approach to cast Al–Cu–Li alloy AA2195 as compared to the conventional Direct Chill (DC) casting of aluminum alloys. This paper describes the processing requirements for melting and casting of 200 kg of Al–Cu–Li alloy in a Vacuum Induction Melting (VIM) furnace under dynamic inert atmosphere. The as-cast billets have been homogenized to remove microsegregation as well as to avoid incipient melting, and subsequently subjected for secondary metal processing operations viz., forging and rolling. The product in the form of 4 mm thick sheets was subjected to various heat treatments in T8 (Solution Treatment+WQ+CW+Aging) condition. Mechanical properties were evaluated at room temperature and were correlated with microstructures of the sheets processed under different conditions using transmission electron microscopy (TEM)

  16. Processing and characterization of Al–Cu–Li alloy AA2195 undergoing scale up production through the vacuum induction melting technique

    International Nuclear Information System (INIS)

    Nayan, Niraj; Murty, S.V.S. Narayana; Jha, Abhay K.; Pant, Bhanu; Sharma, S.C.; George, Koshy M.; Sastry, G.V.S.

    2013-01-01

    The inherent properties of lithium, such as high reactivity and toxicity, relatively low density, low melting point, along with its high cost requires a special technological approach to cast Al–Cu–Li alloy AA2195 as compared to the conventional Direct Chill (DC) casting of aluminum alloys. This paper describes the processing requirements for melting and casting of 200 kg of Al–Cu–Li alloy in a Vacuum Induction Melting (VIM) furnace under dynamic inert atmosphere. The as-cast billets have been homogenized to remove microsegregation as well as to avoid incipient melting, and subsequently subjected for secondary metal processing operations viz., forging and rolling. The product in the form of 4 mm thick sheets was subjected to various heat treatments in T8 (Solution Treatment+WQ+CW+Aging) condition. Mechanical properties were evaluated at room temperature and were correlated with microstructures of the sheets processed under different conditions using transmission electron microscopy (TEM)

  17. Matrix-assisted cocrystallization (MAC) simultaneous production and formulation of pharmaceutical cocrystals by hot-melt extrusion.

    Science.gov (United States)

    Boksa, Kevin; Otte, Andrew; Pinal, Rodolfo

    2014-09-01

    A novel method for the simultaneous production and formulation of pharmaceutical cocrystals, matrix-assisted cocrystallization (MAC), is presented. Hot-melt extrusion (HME) is used to create cocrystals by coprocessing the drug and coformer in the presence of a matrix material. Carbamazepine (CBZ), nicotinamide (NCT), and Soluplus were used as a model drug, coformer, and matrix, respectively. The MAC product containing 80:20 (w/w) cocrystal:matrix was characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, and powder X-ray diffraction. A partial least squares (PLS) regression model was developed for quantifying the efficiency of cocrystal formation. The MAC product was estimated to be 78% (w/w) cocrystal (theoretical 80%), with approximately 0.3% mixture of free (unreacted) CBZ and NCT, and 21.6% Soluplus (theoretical 20%) with the PLS model. A physical mixture (PM) of a reference cocrystal (RCC), prepared by precipitation from solution, and Soluplus resulted in faster dissolution relative to the pure RCC. However, the MAC product with the exact same composition resulted in considerably faster dissolution and higher maximum concentration (∼five-fold) than those of the PM. The MAC product consists of high-quality cocrystals embedded in a matrix. The processing aspect of MAC plays a major role on the faster dissolution observed. The MAC approach offers a scalable process, suitable for the continuous manufacturing and formulation of pharmaceutical cocrystals. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  18. Processing effects in production of composite prepreg by hot melt impregnation

    Science.gov (United States)

    Chmielewski, C.; Jayaraman, K.; Petty, C. A.

    1993-06-01

    The hot melt impregnation process for producing composite prepreg has been studied. The role of the exit die is highlighted by operating without impregnation bars. Experimental results show that when a fiber tow is pulled through a resin bath and then through a wedge shaped die, the total resin mass fraction and the extent of resin impregnation in the tow increase with the processing viscosity. The penetration of resin into a fiber bundle is greater when the resin viscosity is higher. This trend is unchanged over a range of tow speeds up to the breaking point. A theoretical model is developed to describe the effect of processing conditions and die geometry on the degree of impregnation. Calculations with this model indicate that for a given die geometry, the degree of impregnation increases from 58 percent to 90 percent as the ratio of the clearance between the tow and the die wall, to the total die gap is decreased from 0.15 to 0.05. Physical arguments related to the effective viscosity of the prepreg show that the clearance ratio is independent of the tow speed, but decreases as the ratio of the effective shear viscosity of the prepreg to the resin viscosity increases. This provides a connection between the experimental results obtained with varying resin viscosity and the computational results obtained with varying clearance values at the die inlet.

  19. Effects of Geomechanical Mechanism on the Gas Production Behavior: A Simulation Study of Class-3 Type Four-Way-Closure Ridge Hydrate Deposit Offshore Southwestern Taiwan

    Science.gov (United States)

    Wu, Cheng-Yueh; Chiu, Yung-Cheng; Huang, Yi-Jyun; Hsieh, Bieng-Zih

    2017-04-01

    The future energy police of Taiwan will heavily rely on the clean energy, including renewable energy and low-carbon energy, to meet the target of mitigating CO2 emission. In addition to developing the renewable energies like solar and wind resources, Taiwan will increase the natural gas consumption to obtain enough electrical power with low-carbon emission. The vast resources of gas hydrates recognized in southwestern offshore Taiwan makes a great opportunity for Taiwan to have own energy resources in the future. Therefore, Taiwan put significant efforts on the evaluation of gas hydrate reserves recently. Production behavior of natural gas dissociated from gas hydrate deposits is an important issue to the hydrate reserves evaluation. The depressurization method is a useful engineering recovery method for gas production from a class-3 type hydrate deposit. The dissociation efficiency will be affected by the pressure drawdown disturbance. However, when the pore pressure of hydrate deposits is depressurized for gas production, the rock matrix will surfer more stresses and the formation deformation might be occurred. The purpose of this study was to investigate the effects of geomechanical mechanism on the gas production from a class-3 hydrate deposit using depressurization method. The case of a class-3 type hydrate deposit of Four-Way-Closure Ridge was studied. In this study a reservoir simulator, STARS, was used. STARS is a multiphase flow, heat transfer, geo-chemical and geo-mechanical mechanisms coupling simulator which is capable to simulate the dissociation/reformation of gas hydrate and the deformation of hydrate reservoirs and overburdens. The simulating ability of STARTS simulator was validated by duplicating the hydrate comparison projects of National Energy Technology Lab. The study target, Four-Way-Closure (FWC) Ridge hydrate deposit, was discovered by the bottom simulating reflectors (BSRs). The geological parameters were collected from the geological and

  20. Process design and control of a twin screw hot melt extrusion for continuous pharmaceutical tamper-resistant tablet production.

    Science.gov (United States)

    Baronsky-Probst, J; Möltgen, C-V; Kessler, W; Kessler, R W

    2016-05-25

    Hot melt extrusion (HME) is a well-known process within the plastic and food industries that has been utilized for the past several decades and is increasingly accepted by the pharmaceutical industry for continuous manufacturing. For tamper-resistant formulations of e.g. opioids, HME is the most efficient production technique. The focus of this study is thus to evaluate the manufacturability of the HME process for tamper-resistant formulations. Parameters such as the specific mechanical energy (SME), as well as the melt pressure and its standard deviation, are important and will be discussed in this study. In the first step, the existing process data are analyzed by means of multivariate data analysis. Key critical process parameters such as feed rate, screw speed, and the concentration of the API in the polymers are identified, and critical quality parameters of the tablet are defined. In the second step, a relationship between the critical material, product and process quality attributes are established by means of Design of Experiments (DoEs). The resulting SME and the temperature at the die are essential data points needed to indirectly qualify the degradation of the API, which should be minimal. NIR-spectroscopy is used to monitor the material during the extrusion process. In contrast to most applications in which the probe is directly integrated into the die, the optical sensor is integrated into the cooling line of the strands. This saves costs in the probe design and maintenance and increases the robustness of the chemometric models. Finally, a process measurement system is installed to monitor and control all of the critical attributes in real-time by means of first principles, DoE models, soft sensor models, and spectroscopic information. Overall, the process is very robust as long as the screw speed is kept low. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Melt inclusions: Chapter 6

    Science.gov (United States)

    ,; Lowenstern, J. B.

    2014-01-01

    Melt inclusions are small droplets of silicate melt that are trapped in minerals during their growth in a magma. Once formed, they commonly retain much of their initial composition (with some exceptions) unless they are re-opened at some later stage. Melt inclusions thus offer several key advantages over whole rock samples: (i) they record pristine concentrations of volatiles and metals that are usually lost during magma solidification and degassing, (ii) they are snapshots in time whereas whole rocks are the time-integrated end products, thus allowing a more detailed, time-resolved view into magmatic processes (iii) they are largely unaffected by subsolidus alteration. Due to these characteristics, melt inclusions are an ideal tool to study the evolution of mineralized magma systems. This chapter first discusses general aspects of melt inclusions formation and methods for their investigation, before reviewing studies performed on mineralized magma systems.

  2. SolarProTeam - Final report; Solar production technology melts architects

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    To this date, no module manufacturing line has been able to produce special designed multiple function modules or Custom Design Solution (hereafter CDS) modules at costs that are anywhere near the costs of standard modules. The goal of this R and D project was to provide the basis for eliminating the multiplication of costs for specialised modules. The purpose of the SolarProTeam R and D project is to form the foundation of special production equipment and production lay-out in order to realise a cost-effective CDS module production line. The main results derive from research and development of: (1) A number of new module designs corresponding to the special demands of end-users. For instance, black shiny modules with high efficiency; long large black modules with in-built thermal absorbers; flexible high voltage lightweight modules for ground water pumping; large area curved colorful modules with for architecturally advanced buildings; a solar tree for power supply placed along roads and in public places. Module designs are reported. (2) A new general concept 'Q-keys' based on a master plan and specially designed modules integrating both very large and medium sized individual solar plants in the environment of the end-user. I.e., in addition to integration with regard to architectural and environment demands, integration with respect to technical demands are met, such as storage, desalination plants, cooling, mini-grids, the general grid, etc. The Q-keys concept emphasizes the financial issue in that the solar plants are competitive with coal generated electricity and stand-alone diesel generation of electricity. (3) Fully automated production equipment and a semi-automatic module production line, which can mass produce advanced multifunctional and/or architecturally integrated modules at a cost effective price. The equipment and production line were inspired by the functional and technological demands of different types of costumer designed modules. Due

  3. Multiscale Modeling of Poly(lactic acid) Production: From Reaction Conditions to Rheology of Polymer Melt

    DEFF Research Database (Denmark)

    Zubov, Alexandr; Sin, Gürkan

    2018-01-01

    Abstract Poly(L-lactic acid) (PLLA) is a fully biodegradable bioplastic with promising market potential. The paper deals with systematic development and analysis of the modeling framework allowing direct mapping between PLLA production process conditions and rheological properties of the polymer ...

  4. Fission Product Separation from Pyrochemical Electrolyte by Cold Finger Melt Crystallization

    Energy Technology Data Exchange (ETDEWEB)

    Versey, Joshua R. [Univ. of Idaho, Moscow, ID (United States)

    2013-08-01

    This work contributes to the development of pyroprocessing technology as an economically viable means of separating used nuclear fuel from fission products and cladding materials. Electrolytic oxide reduction is used as a head-end step before electrorefining to reduce oxide fuel to metallic form. The electrolytic medium used in this technique is molten LiCl-Li2O. Groups I and II fission products, such as cesium (Cs) and strontium (Sr), have been shown to partition from the fuel into the molten LiCl-Li2O. Various approaches of separating these fission products from the salt have been investigated by different research groups. One promising approach is based on a layer crystallization method studied at the Korea Atomic Energy Research Institute (KAERI). Despite successful demonstration of this basic approach, there are questions that remain, especially concerning the development of economical and scalable operating parameters based on a comprehensive understanding of heat and mass transfer. This research explores these parameters through a series of experiments in which LiCl is purified, by concentrating CsCl in a liquid phase as purified LiCl is crystallized and removed via an argon-cooled cold finger.

  5. Production of solid lipid submicron particles for protein delivery using a novel supercritical gas-assisted melting atomization process.

    Science.gov (United States)

    Salmaso, Stefano; Elvassore, Nicola; Bertucco, Alberto; Caliceti, Paolo

    2009-02-01

    A supercritical carbon dioxide micronization technique based on gas-assisted melting atomization has been designed to prepare protein-loaded solid lipid submicron particles. The supercritical process was applied to homogeneous dispersions of insulin in lipid mixtures: (1) tristearin, Tween-80, phosphatidylcholine and 5 kDa PEG (1:0.1:0.9:1 and 1:0.1:0.9:2 weight ratio); and (2) tristearin, dioctyl sulfosuccinate and phosphatidylcholine (1:1:0.5 weight ratio). Optimized process conditions yielded dry nonagglomerated powders with high product recovery (70%, w/w). Dynamic light scattering and transmission electron microscopy showed that two size fractions of particles, with 80-120 and 200-400 nm diameters, were produced. In all final products, dimethylsulfoxide used to prepare the insulin/lipid mixture was below 20 ppm. Protein encapsulation efficiency increased up to 80% as the DMSO content in the insulin/lipid mixture increased. Compared to the particles without PEG, the polymer-containing particles dispersed rapidly in water, and the dispersions were more stable under centrifugation as less than 20% of suspended particles precipitated after extensive centrifugation. In vitro, the protein was slowly released from the formulation without PEG, while a burst and faster release were obtained from the formulations containing PEG. Subcutaneous injection to diabetic mice of insulin extracted from the particles showed that the supercritical process did not impair the protein hypoglycemic activity.

  6. Geodynamic control on melt production in the central Azores : new insights from major and trace elements, Sr, Nd, Pb, Hf isotopic data and K/Ar ages on the islands of Terceira, Sao Jorge and Faial

    Science.gov (United States)

    Hildenbrand, A.; Weis, D. A.; Madureira, P.; Marques, F. O.

    2012-12-01

    A combined geochronological and geochemical study has been carried out on the volcanic islands of Terceira, São Jorge, and Faial (central Azores) to examine the relationships between mantle dynamics, melt production and regional deformation close to the triple junction between the American, the Eurasian and the Nubian lithospheric plates. The lavas analyzed span the last 1.3 Myr, and have been erupted during two main periods prior to 800 ka and after 750 ka, respectively. They range in composition from alkaline basalts/basanites to trachytes, and overall exhibit a strong enrichment in highly incompatible elements. The whole range of isotopic compositions here reported (87Sr/86Sr: 0.703508-0.703913; 143Nd/144Nd: 0.512882-0.513010; 206Pb/204Pb: 19.0840- 20.0932; 207Pb/204Pb: 15.5388-15.6409; 208Pb/204Pb: 38.7416-39.3921; 176Hf/177Hf: 0.282956-0.283111) suggests the involvement of three components: (1) a weakly radiogenic component reflecting the source of regional MORBs, (2) a main HIMU-type component represented in the three islands, and (3) an additional component in Faial recent lavas, which appears similar to the EM type end-member previously recognized on other Azores eruptive complexes. The geographical distribution of the enriched components and the synchronous construction of various islands at the regional scale rules out a single narrow active plume. They suggest in turn the presence of dispersed residual enriched mantle blobs, interpreted as remnants from a large heterogeneous plume probably responsible for edification of the Azores plateau several Myr ago. The lavas erupted in São Jorge and Faial prior to 800 ka have similar and homogeneous isotopic ratios, which partly overlap the compositional field of MORBs from the adjacent portion of the Mid-Atlantic Ridge (MAR). Their genesis can be explained by the regional development of N150 transtensive tectonic structures, which promoted significant decompression melting of the upper mantle, with correlative

  7. Treatability study work plan for in situ vitrification of seepage pit 1 in Waste Area Grouping 7 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Spalding, B.P.

    1994-07-01

    A treatability study is described that encompasses the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage pit 1 by the end of fiscal year 1995. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability for the overlapping melt settings that are necessary to achieve fused melt segments; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of 137 Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. The initial step of this treatability study will be to gather the required site characterization data about pit 1 so that the in situ vitrification can be effectively and safely planned. The second phase will be the field ISV operations at pit 1 employing at least two settings to achieve overlapping and fused melts. Such field operations are likely to require 6 to 8 weeks. Following termination of ISV melting operations at pit 1 and demobilization of portable ISV equipment and the off-gas hood, posttest characterization activities will begin

  8. Preliminary Analysis of the Knipovich Ridge Segmentation - Influence of Focused Magmatism and Ridge Obliquity on an Ultraslow Spreading System

    Science.gov (United States)

    Okino, K.; Curewitz, D.; Asada, M.; Tamaki, K.

    2002-12-01

    Bathymetry, gravity and deep-tow sonar image data are used to define the segmentation of a 400 km long portion of the ultraslow-spreading Knipovich Ridge in the Norwegian-Greenland Sea, Northeast Atlantic Ocean. Discrete volcanic centers marked by large volcanic constructions and accompanying short wavelength mantle Bouguer anomaly (MBA) lows generally resemble those of the Gakkel Ridge and the easternmost Southwest Indian Ridge (SWIR). These magmatically robust segment centers are regularly spaced about 85-100 km apart along the ridge, and are characterized by accumulated hummocky terrain, high relief, off-axis seamount chains and significant MBA lows. We suggest that these eruptive centers correspond to areas of enhanced magma flux, and that their spacing reflects the geometry of underlying mantle upwelling cells. The large-scale thermal structure of the mantle primarily controls discrete and focused magmatism, and the relatively wide spacing of these segments may reflect cool mantle beneath the ridge. Segment centers along the southern Knipovich Ridge are characterized by lower relief and smaller MBA anomalies than along the northern section of the ridge. This suggests that ridge obliquity is a secondary control on ridge construction on the Knipovich Ridge, as the obliquity changes from 35° to 49° from north to south, respectively, while spreading rate and axial depth remain approximately constant. The increased obliquity may contribute to decreased effective spreading rates, lower upwelling magma velocity and melt formation, and limited horizontal dike propagation near the surface. We also identify small, magmatically weaker segments with low relief, little or no MBA anomaly, and no off axis expression. We suggest that these segments are either fed by lateral melt migration from adjacent magmatically stronger segments or represent smaller, discrete mantle upwelling centers with short-lived melt supply.

  9. Preliminary analysis of the Knipovich Ridge segmentation: influence of focused magmatism and ridge obliquity on an ultraslow spreading system

    Science.gov (United States)

    Okino, Kyoko; Curewitz, Daniel; Asada, Miho; Tamaki, Kensaku; Vogt, Peter; Crane, Kathleen

    2002-09-01

    Bathymetry, gravity and deep-tow sonar image data are used to define the segmentation of a 400 km long portion of the ultraslow-spreading Knipovich Ridge in the Norwegian-Greenland Sea, Northeast Atlantic Ocean. Discrete volcanic centers marked by large volcanic constructions and accompanying short wavelength mantle Bouguer anomaly (MBA) lows generally resemble those of the Gakkel Ridge and the easternmost Southwest Indian Ridge. These magmatically robust segment centers are regularly spaced about 85-100 km apart along the ridge, and are characterized by accumulated hummocky terrain, high relief, off-axis seamount chains and significant MBA lows. We suggest that these eruptive centers correspond to areas of enhanced magma flux, and that their spacing reflects the geometry of underlying mantle upwelling cells. The large-scale thermal structure of the mantle primarily controls discrete and focused magmatism, and the relatively wide spacing of these segments may reflect cool mantle beneath the ridge. Segment centers along the southern Knipovich Ridge are characterized by lower relief and smaller MBA anomalies than along the northern section of the ridge. This suggests that ridge obliquity is a secondary control on ridge construction on the Knipovich Ridge, as the obliquity changes from 35° to 49° from north to south, respectively, while spreading rate and axial depth remain approximately constant. The increased obliquity may contribute to decreased effective spreading rates, lower upwelling magma velocity and melt formation, and limited horizontal dike propagation near the surface. We also identify small, magmatically weaker segments with low relief, little or no MBA anomaly, and no off-axis expression. We suggest that these segments are either fed by lateral melt migration from adjacent magmatically stronger segments or represent smaller, discrete mantle upwelling centers with short-lived melt supply.

  10. A comparative study between hot-melt extrusion and spray-drying for the manufacture of anti-hypertension compatible monolithic fixed-dose combination products.

    Science.gov (United States)

    Kelleher, J F; Gilvary, G C; Madi, A M; Jones, D S; Li, S; Tian, Y; Almajaan, A; Senta-Loys, Z; Andrews, G P; Healy, A M

    2018-07-10

    The purpose of this work was to investigate the application of different advanced continuous processing techniques (hot melt extrusion and spray drying) to the production of fixed-dose combination (FDC) monolithic systems comprising of hydrochlorothiazide and ramipril for the treatment of hypertension. Identical FDC formulations were manufactured by the two different methods and were characterised using powder X-ray diffraction (PXRD) and modulated differential scanning calorimetry (mDSC). Drug dissolution rates were investigated using a Wood's apparatus, while physical stability was assessed on storage under controlled temperature and humidity conditions. Interestingly both drugs were transformed into their amorphous forms when spray dried, however, hydrochlorothiazide was determined, by PXRD, to be partially crystalline when hot melt extruded with either polymer carrier (Kollidon® VA 64 or Soluplus®). Hot melt extrusion was found to result in significant degradation of ramipril, however, this could be mitigated by the inclusion of the plasticizer, polyethylene glycol 3350, in the formulation and appropriate adjustment of processing temperature. The results of intrinsic dissolution rate studies showed that hot-melt extruded samples were found to release both drugs faster than identical formulations produced via spray drying. However, the differences were attributable to the surface roughness of the compressed discs in the Wood's apparatus, rather than solid state differences between samples. After a 60-day stability study spray dried samples exhibited a greater physical stability than the equivalent hot melt extruded samples. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Environmentally friendly and highly productive bi-component melt spinning of thermoregulated smart polymer fibres with high latent heat capacity

    Directory of Open Access Journals (Sweden)

    Ch. Cherif

    2018-03-01

    Full Text Available A stable and reproducible bi-component melt spinning process on an industrial scale incorporating Phase Change Material (PCM into textile fibres has been successfully developed and carried out using a melt spinning machine. The key factor for a successful bi-component melt spinning process is that a deep insight into the thermal and rheological behaviour of PCM using Difference Scanning Calorimetry (DSC, Thermogravimetric Analysis (TGA, and an oscillatory rheological investigation. PCM is very sensitive to the temperature and residence time of the melt spinning process. It is found that the optimal process temperature of PCM is 210 °C. The textile-physical properties and the morphology of the melt spun and further drawn bi-component core and sheath fibres (bico fibres were investigated and interpreted. The heat capacities of PCM incorporated in bico fibres were also determined by means of DSC. The melt spun bico fibres integrating PCM provide a high latent heat of up to 22 J/g, which is three times higher than that of state-of-the-art fibres, which were also obtained using the melt spinning process. Therefore, they have the potential to be used as smart polymer fibres for textile and other technical applications.

  12. Exploiting Process-Related Advantages of Selective Laser Melting for the Production of High-Manganese Steel.

    Science.gov (United States)

    Haase, Christian; Bültmann, Jan; Hof, Jan; Ziegler, Stephan; Bremen, Sebastian; Hinke, Christian; Schwedt, Alexander; Prahl, Ulrich; Bleck, Wolfgang

    2017-01-11

    Metal additive manufacturing has strongly gained scientific and industrial importance during the last decades due to the geometrical flexibility and increased reliability of parts, as well as reduced equipment costs. Within the field of metal additive manufacturing methods, selective laser melting (SLM) is an eligible technique for the production of fully dense bulk material with complex geometry. In the current study, we addressed the application of SLM for processing a high-manganese TRansformation-/TWinning-Induced Plasticity (TRIP/TWIP) steel. The solidification behavior was analyzed by careful characterization of the as-built microstructure and element distribution using optical and scanning electron microscopy (SEM). In addition, the deformation behavior was studied using uniaxial tensile testing and SEM. Comparison with conventionally produced TRIP/TWIP steel revealed that elemental segregation, which is normally very pronounced in high-manganese steels and requires energy-intensive post processing, is reduced due to the high cooling rates during SLM. Also, the very fast cooling promoted ε- and α'-martensite formation prior to deformation. The superior strength and pronounced anisotropy of the SLM-produced material was correlated with the microstructure based on the process-specific characteristics.

  13. Exploiting Process-Related Advantages of Selective Laser Melting for the Production of High-Manganese Steel

    Directory of Open Access Journals (Sweden)

    Christian Haase

    2017-01-01

    Full Text Available Metal additive manufacturing has strongly gained scientific and industrial importance during the last decades due to the geometrical flexibility and increased reliability of parts, as well as reduced equipment costs. Within the field of metal additive manufacturing methods, selective laser melting (SLM is an eligible technique for the production of fully dense bulk material with complex geometry. In the current study, we addressed the application of SLM for processing a high-manganese TRansformation-/TWinning-Induced Plasticity (TRIP/TWIP steel. The solidification behavior was analyzed by careful characterization of the as-built microstructure and element distribution using optical and scanning electron microscopy (SEM. In addition, the deformation behavior was studied using uniaxial tensile testing and SEM. Comparison with conventionally produced TRIP/TWIP steel revealed that elemental segregation, which is normally very pronounced in high-manganese steels and requires energy-intensive post processing, is reduced due to the high cooling rates during SLM. Also, the very fast cooling promoted ε- and α’-martensite formation prior to deformation. The superior strength and pronounced anisotropy of the SLM-produced material was correlated with the microstructure based on the process-specific characteristics.

  14. Interim report on research between Oak Ridge National Laboratory and Japan Nuclear Cycle Development Institute on neutron-capture cross sections by long-lived fission product nuclides

    International Nuclear Information System (INIS)

    Furutaka, Kazuyoshi; Nakamura, Shoji; Harada, Hideo

    2004-03-01

    Neutron capture cross sections of long-lived fission products (LLFP) are important quantities as fundamental data for the study of nuclear transmutation of radioactive wastes. Previously obtained thermal-neutron capture gamma-ray data were analyzed to deduce the partial neutron-capture cross sections of LLFPs including 99 Tc, 93 Zr, and 107 Pd for thermal neutrons. By comparing the decay gamma-ray data and prompt gamma-ray data for 99 Tc, the relation between the neutron-capture cross section deduced by the two different methods was studied. For the isotopes 93 Zr and 107 Pd, thermal neutron-capture gamma-ray production cross sections were deduced for the first time. The level schemes of 99 Tc, 93 Zr, and 107 Pd have also been constructed form the analyzed data and compared with previously reported levels. This work has been done under the cooperative program 'Neutron Capture Cross Sections of Long-Lived Fission products (LLFPs)' by Japan Nuclear Cycle Development Institute (JNC) and Oak Ridge National Laboratory (ORNL). (author)

  15. New processing techniques for radioisotopes at Oak Ridge National Laboratory; Production de radioisotopes: nouvelles techniques employees au Laboratoire national d'Oak Ridge; Novye tekhnologicheskie metody polucheniya radioizotopov v Okridzhskoj natsional'noj laboratorii; Nuevos metodos de preparacion de radioisotopos aplicados en el Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Butler, T A; Lamb, E; Rupp, A F [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1962-01-15

    Recent developments in the radioisotope production programme at Oak Ridge National Laboratory include new processes and process improvements for the production of cerium-144, promethium-147, technetium-99 and strontium-90. Cerium-144 has been produced in kc quantities in a test run. A product recovery of more than 98% with a product purity of more than 99% was attained. The cerium was further processed to obtain pure cerium-144 oxide powder having an activity concentration of 235 c/g. The powder was pressed into pellets which were sintered to a dense ceramic form. Promethium-147 has been produced in kc quantities by a combination of precipitation and ion exchange techniques. A solvent extraction system for separating promethium- 147 from other rare earths has been tested on a tracer scale. Gram quantities of technetium-99 have been recovered from fission-product waste streams by a combination of precipitation and solvent extraction processes. The technetium product was produced with a chemical purity of more than 99.9% and radiochemical purity of more than 99.99%. The separation and purification of strontium-90 from gross contaminants by a continuous solvent-extraction flowsheet has been demonstrated on a tracer scale. Product quality of 98% strontium has been achieved from feed containing 95% inert calcium contaminant. The strontium-90 is further processed to form strontium titanate ceramic elements. (author) [French] Les faits recents a noter dans le programme de production de radioisotopes du laboratoire national d'Oak Ridge sont l'introduction de nouvelles methodes et l'amelioration des techniques existantes pour la production du eerium-144, du prometheum-147, du technetium-99 et du strontium-90. Le cerium-144 a ete obtenu en quantites de l'ordre du kilocurie, lors d'une experience. On a obtenu un taux d'extraction de plus de 98% et un produit d'une purete superieure a 99%. On a ensuite traite le cerium pour avoir de l'oxyde de cerium-144 pur en poudre ayant

  16. Dynamics of Melting and Melt Migration as Inferred from Incompatible Trace Element Abundance in Abyssal Peridotites

    Science.gov (United States)

    Peng, Q.; Liang, Y.

    2008-12-01

    To better understand the melting processes beneath the mid-ocean ridge, we developed a simple model for trace element fractionation during concurrent melting and melt migration in an upwelling steady-state mantle column. Based on petrologic considerations, we divided the upwelling mantle into two regions: a double- lithology upper region where high permeability dunite channels are embedded in a lherzolite/harzburgite matrix, and a single-lithology lower region that consists of partially molten lherzolite. Melt generated in the single lithology region migrates upward through grain-scale diffuse porous flow, whereas melt in the lherzolite/harzburgite matrix in the double-lithology region is allowed to flow both vertically through the overlying matrix and horizontally into its neighboring dunite channels. There are three key dynamic parameters in our model: degree of melting experienced by the single lithology column (Fd), degree of melting experienced by the double lithology column (F), and a dimensionless melt suction rate (R) that measures the accumulated rate of melt extraction from the matrix to the channel relative to the accumulated rate of matrix melting. In terms of trace element fractionation, upwelling and melting in the single lithology column is equivalent to non-modal batch melting (R = 0), whereas melting and melt migration in the double lithology region is equivalent to a nonlinear combination of non-modal batch and fractional melting (0 abyssal peridotite, we showed, with the help of Monte Carlo simulations, that it is difficult to invert for all three dynamic parameters from a set of incompatible trace element data with confidence. However, given Fd, it is quite possible to constrain F and R from incompatible trace element abundances in residual peridotite. As an illustrative example, we used the simple melting model developed in this study and selected REE and Y abundance in diopside from abyssal peridotites to infer their melting and melt migration

  17. Trace element and isotopic effects arising from magma migration beneath mid-ocean ridges

    International Nuclear Information System (INIS)

    Kenyon, P.M.

    1990-01-01

    The trace element concentrations and isotopic ratios in the magma erupted on mid-ocean ridges may differ from those in the source material due to physical effects such as porous flow dispersion, exchange of trace elements between the fluid and solid phases during magma migration, and convective mixing in magma chambers. These differences are in addition to those produced by better known processes such as fractional crystallization and partial melting. The effects of the three former processes are described. It is predicted that magma typically reaches the sub-ridge magma chambers with a spatial heterogeneity only slightly reduced from that of the source material, but with a subdued variation in time. Convective mixing then further reduces the spatial heterogeneity. Application of the results for convective mixing to a recent Fourier analysis of 87 Sr/ 86 Sr variations along the Mid-Atlantic Ridge suggests that the falloff in amplitude of variation observed with decreasing wavelength in the Mid-Atlantic Ridge data cannot be explained by convective mixing in magma chambers. Instead, it is postulated that this falloff is due to the mechanics of the production and/or the solid-state convective mixing of chemical and isotopic heterogeneities in the solid mantle. (orig.)

  18. Permeability and 3-D melt geometry in shear-induced high melt fraction conduits

    Science.gov (United States)

    Zhu, W.; Cordonnier, B.; Qi, C.; Kohlstedt, D. L.

    2017-12-01

    Observations of dunite channels in ophiolites and uranium-series disequilibria in mid-ocean ridge basalt suggest that melt transport in the upper mantle beneath mid-ocean ridges is strongly channelized. Formation of high melt fraction conduits could result from mechanical shear, pyroxene dissolution, and lithological partitioning. Deformation experiments (e.g. Holtzman et al., 2003) demonstrate that shear stress causes initially homogeneously distributed melt to segregate into an array of melt-rich bands, flanked by melt-depleted regions. At the same average melt fraction, the permeability of high melt fraction conduits could be orders of magnitude higher than that of their homogenous counterparts. However, it is difficult to determine the permeability of melt-rich bands. Using X-ray synchrotron microtomography, we obtained high-resolution images of 3-dimensional (3-D) melt distribution in a partially molten rock containing shear-induced high melt fraction conduits. Sample CQ0705, an olivine-alkali basalt aggregate with a nominal melt fraction of 4%, was deformed in torsion at a temperature of 1473 K and a confining pressure of 300 MPa to a shear strain of 13.3. A sub-volume of CQ0705 encompassing 3-4 melt-rich bands was imaged. Microtomography data were reduced to binary form so that solid olivine is distinguishable from basalt glass. At a spatial resolution of 160 nm, the 3-D images reveal the shape and connectedness of melt pockets in the melt-rich bands. Thin melt channels formed at grain edges are connected at large melt nodes at grain corners. Initial data analysis shows a clear preferred orientation of melt pockets alignment subparallel to the melt-rich band. We use the experimentally determined geometrical parameters of melt topology to create a digital rock with identical 3-D microstructures. Stokes flow simulations are conducted on the digital rock to obtain the permeability tensor. Using this digital rock physics approach, we determine how deformation

  19. Mapping upland hardwood site quality and productivity with GIS and FIA in the Blue Ridge of North Carolina

    Science.gov (United States)

    Claudia A. Cotton; Stephen R. Prisley; Thomas R. Fox

    2009-01-01

    The forested ecosystems of the southern Appalachians are some of the most diverse in North America due to the variability in climate, soils, and geologic parent material coupled with the complex topography found throughout the region. These same characteristics cause stands of upland hardwoods to be extremely variable with regard to site quality and productivity. Site...

  20. Process optimization of atomized melt deposition for the production of dispersion strengthened Al-8.5%Fe-1.2%V-1.7%Si alloys

    International Nuclear Information System (INIS)

    Hariprasad, S.; Sastry, S.M.L.; Jerina, K.L.

    1995-01-01

    Atomized melt deposition is a low cost manufacturing process with the microstructural control achieved through rapid solidification. In this process the liquid metal is disintegrated into fine droplets by gas atomization and the droplets are deposited on a substrate producing near net shape products. In the present investigation Al-8.5%Fe-1.2%V-1.7%Si alloy was produced using atomized melt deposition process to study the evolution of microstructure and assess the cooling rates and the undercooling achieved during the process. The size, morphology and the composition of second phase particles in the alloy are strong functions of the cooling rate and the undercooling and hence microstructural changes with the variation in process parameters were quantified. To define optimum conditions for the atomized melt deposition process, a mathematical model was developed. The model determines the temperature distribution of the liquid droplets during gas atomization and during the deposition stages. The model predicts the velocity distribution, cooling rates and the fraction solid, during the flight for different droplet sizes. The solidification heat transfer phenomena taking place during the atomized melt deposition process was analyzed using a finite difference method based on the enthalpy formulation

  1. An integrated modeling system for estimating glacier and snow melt driven streamflow from remote sensing and earth system data products in the Himalayas

    Science.gov (United States)

    Brown, M. E.; Racoviteanu, A. E.; Tarboton, D. G.; Gupta, A. Sen; Nigro, J.; Policelli, F.; Habib, S.; Tokay, M.; Shrestha, M. S.; Bajracharya, S.; Hummel, P.; Gray, M.; Duda, P.; Zaitchik, B.; Mahat, V.; Artan, G.; Tokar, S.

    2014-11-01

    Quantification of the contribution of the hydrologic components (snow, ice and rain) to river discharge in the Hindu Kush Himalayan (HKH) region is important for decision-making in water sensitive sectors, and for water resources management and flood risk reduction. In this area, access to and monitoring of the glaciers and their melt outflow is challenging due to difficult access, thus modeling based on remote sensing offers the potential for providing information to improve water resources management and decision making. This paper describes an integrated modeling system developed using downscaled NASA satellite based and earth system data products coupled with in-situ hydrologic data to assess the contribution of snow and glaciers to the flows of the rivers in the HKH region. Snow and glacier melt was estimated using the Utah Energy Balance (UEB) model, further enhanced to accommodate glacier ice melt over clean and debris-covered tongues, then meltwater was input into the USGS Geospatial Stream Flow Model (GeoSFM). The two model components were integrated into Better Assessment Science Integrating point and Nonpoint Sources modeling framework (BASINS) as a user-friendly open source system and was made available to countries in high Asia. Here we present a case study from the Langtang Khola watershed in the monsoon-influenced Nepal Himalaya, used to validate our energy balance approach and to test the applicability of our modeling system. The snow and glacier melt model predicts that for the eight years used for model evaluation (October 2003-September 2010), the total surface water input over the basin was 9.43 m, originating as 62% from glacier melt, 30% from snowmelt and 8% from rainfall. Measured streamflow for those years were 5.02 m, reflecting a runoff coefficient of 0.53. GeoSFM simulated streamflow was 5.31 m indicating reasonable correspondence between measured and model confirming the capability of the integrated system to provide a quantification of

  2. An Integrated Modeling System for Estimating Glacier and Snow Melt Driven Streamflow from Remote Sensing and Earth System Data Products in the Himalayas

    Science.gov (United States)

    Brown, M. E.; Racoviteanu, A. E.; Tarboton, D. G.; Sen Gupta, A.; Nigro, J.; Policelli, F.; Habib, S.; Tokay, M.; Shrestha, M. S.; Bajracharya, S.

    2014-01-01

    Quantification of the contribution of the hydrologic components (snow, ice and rain) to river discharge in the Hindu Kush Himalayan (HKH) region is important for decision-making in water sensitive sectors, and for water resources management and flood risk reduction. In this area, access to and monitoring of the glaciers and their melt outflow is challenging due to difficult access, thus modeling based on remote sensing offers the potential for providing information to improve water resources management and decision making. This paper describes an integrated modeling system developed using downscaled NASA satellite based and earth system data products coupled with in-situ hydrologic data to assess the contribution of snow and glaciers to the flows of the rivers in the HKH region. Snow and glacier melt was estimated using the Utah Energy Balance (UEB) model, further enhanced to accommodate glacier ice melt over clean and debris-covered tongues, then meltwater was input into the USGS Geospatial Stream Flow Model (Geo- SFM). The two model components were integrated into Better Assessment Science Integrating point and Nonpoint Sources modeling framework (BASINS) as a user-friendly open source system and was made available to countries in high Asia. Here we present a case study from the Langtang Khola watershed in the monsoon-influenced Nepal Himalaya, used to validate our energy balance approach and to test the applicability of our modeling system. The snow and glacier melt model predicts that for the eight years used for model evaluation (October 2003-September 2010), the total surface water input over the basin was 9.43 m, originating as 62% from glacier melt, 30% from snowmelt and 8% from rainfall. Measured streamflow for those years were 5.02 m, reflecting a runoff coefficient of 0.53. GeoSFM simulated streamflow was 5.31 m indicating reasonable correspondence between measured and model confirming the capability of the integrated system to provide a quantification

  3. Emerging melt quality control solution technologies for aluminium melt

    Directory of Open Access Journals (Sweden)

    Arturo Pascual, Jr

    2009-11-01

    Full Text Available The newly developed “MTS 1500” Melt Treatment System is performing the specifi cally required melt treatment operations like degassing, cleaning, modification and/or grain refinement by an automated process in one step and at the same location. This linked process is saving time, energy and metal losses allowing - by automated dosage of the melt treatment agents - the production of a consistent melt quality batch after batch. By linking the MTS Metal Treatment System with sensors operating on-line in the melt, i.e., with a hydrogen sensor “Alspek H”, a fully automated control of parts of the process chain like degassing is possible. This technology does guarantee a pre-specifi ed and documented melt quality in each melt treatment batch. Furthermore, to ensure that castings are consistent and predictable there is a growing realization that critical parameters such as metal cleanliness must be measured prior to casting. There exists accepted methods for measuring the cleanliness of an aluminum melt but these can be both slow and costly. A simple, rapid and meaningful method of measuring and bench marking the cleanliness of an aluminum melt has been developed to offer the foundry a practical method of measuring melt cleanliness. This paper shows the structure and performance of the integrated MTS melt treatment process and documents achieved melt quality standards after degassing, cleaning, modifi cation and grain refi nement operations under real foundry conditions. It also provides an insight on a melt cleanliness measuring device “Alspek MQ” to provide foundry men better tools in meeting the increasing quality and tighter specifi cation demand from the industry.

  4. Petrological Geodynamics of Mantle Melting II. AlphaMELTS + Multiphase Flow: Dynamic Fractional Melting

    Science.gov (United States)

    Tirone, Massimiliano

    2018-03-01

    In this second installment of a series that aims to investigate the dynamic interaction between the composition and abundance of the solid mantle and its melt products, the classic interpretation of fractional melting is extended to account for the dynamic nature of the process. A multiphase numerical flow model is coupled with the program AlphaMELTS, which provides at the moment possibly the most accurate petrological description of melting based on thermodynamic principles. The conceptual idea of this study is based on a description of the melting process taking place along a 1-D vertical ideal column where chemical equilibrium is assumed to apply in two local sub-systems separately on some spatial and temporal scale. The solid mantle belongs to a local sub-system (ss1) that does not interact chemically with the melt reservoir which forms a second sub-system (ss2). The local melt products are transferred in the melt sub-system ss2 where the melt phase eventually can also crystallize into a different solid assemblage and will evolve dynamically. The main difference with the usual interpretation of fractional melting is that melt is not arbitrarily and instantaneously extracted from the mantle, but instead remains a dynamic component of the model, hence the process is named dynamic fractional melting (DFM). Some of the conditions that may affect the DFM model are investigated in this study, in particular the effect of temperature, mantle velocity at the boundary of the mantle column. A comparison is made with the dynamic equilibrium melting (DEM) model discussed in the first installment. The implications of assuming passive flow or active flow are also considered to some extent. Complete data files of most of the DFM simulations, four animations and two new DEM simulations (passive/active flow) are available following the instructions in the supplementary material.

  5. Long term evolution and internal architecture of high-energy banner ridges of Mer d'Iroise (Western Brittany, France) : interplay of sea-level, basement morphology, biogenic productivity and hydrodynamics

    Science.gov (United States)

    Le Roy, P., Sr.; Le Dantec, N.; Franzetti, M.; Delacourt, C.; Ehrhold, A.

    2016-12-01

    The recent completion of a coupled seismic and swath bathymetric survey, conducted across the Mer d'Iroise (Atlantic continental shelf, France), provided new data for the study of the long term evolution of deep tidal sand ridges. Three major banner sand ridges composed of biogenic sands were investigated: the Banc du Four, the Haut Fond d'Ouessant and the Banc d'Ar Men. Seismic interpretation reveals a compound internal architecture of these sand ridges with a sedimentary core forming the lower units interpreted to be shoreface deposits and overlain by sandwaves. Sandwave climbing, which combines progradation and accretion, is the major process controlling the growth of the ridges. The elevation of the preserved dune foresets reaches values of about 20 to 30 m and indicate a combination of giant dunes characterized by numerous steep (up to 20°) clinoforms corresponding to a high-energy depositional environment. All of the radiocarbon ages of the biogenic surficial deposits of the Banc du Four range from 10,036 to 2,748 cal years B.P. and suggest it has grown during the last sea-level rise. The apparent absence of recent surface deposits could be caused by a change in benthic biogenic productivity or the non-conservation of recent deposits. The multiphase accretion of the ridge is closely linked to the progressive flooding of the coastal promontories and straits that structured the igneous basement. A comparable evolutionary scheme is observed for the Haut-Fond d'Ouessant where a counter-clock wise migration of dunes characterizes the surface of the ridge. In contrast, the Banc d'Ar Men located above a regular basement displays a simpler structure with a consistent Northwestward migration of steep clinoforms. Therefore, the sand ridges of the Mer d'Iroise should be thought of as a representative example of large-scale high-energy banner banks controlled by interaction of sea-level, basement morphology, biogenic productivity, tidal and wave hydrodynamics.

  6. Process of irradiating an ethylene-vinyl acetate copolymer to produce low melt index copolymers, and products of said process

    International Nuclear Information System (INIS)

    Potts, J.E.

    1976-01-01

    Application of ionizing radiation in a dose between 0.5 and 1.5 megareps to copolymers of ethylene and vinyl acetate lowers the melt index and increases the toughness and flexibility of the copolymers without substantially decreasing solubility or thermoplasticity. The increased toughness and flexibility carries over into blends with wax or polyethylene. (author)

  7. Marine Export Production and Remineralization During Early Eocene Hyperthermal Events at ODP Site 1263, Walvis Ridge, ODP Site 1209, Shatsky Rise and ODP Site 1215, Equatorial Pacific Ocean

    Science.gov (United States)

    Lewis, A.; Griffith, E. M.; Thomas, E.; Winguth, A. M. E.

    2017-12-01

    Understanding the impacts of global hyperthermal events on marine productivity and remineralization is important for understanding the reaction of the ocean to major climate change. Marine export production and remineralization was reconstructed using marine (pelagic) barite accumulation rates (BAR) coupled with records of benthic foraminiferal assemblages across the Paleocene - Eocene Thermal Maximum (PETM) at 55.3 Ma, Eocene Thermal Maximum 2 (ETM2) 2 Ma later, and ETM3 3.1 Ma after the PETM. Marine barite accumulates in deep sea sediment precipitating in the overlying water column during degradation of organic matter exported from the photic zone. Foraminiferal data indicate the amount of organic matter reaching the seafloor. We use the difference between these records to infer changes in rates of remineralization. We present data from ODP Site on Walvis Ridge, Southeastern Atlantic; ODP Site 1209 on Shatsky Rise, North Pacific; and ODP Site 1215, equatorial Pacific. Sites 1263 and 1215 had maximum BAR roughly centered over the maximum negative PETM CIE, whereas at Site 1209 the maximum was before the PETM. The maximum BAR across ETM2 and ETM3 (0.5 and 0.25 of that at the PETM, respectively) was centered over the maximum negative CIE at Site 1263. At Site 1209, the BAR (0.5 the maximum value before the PETM) peaked before ETM2. Barite concentration at Site 1215 was low across at the smaller hyperthermals, but the onset of ETM2 had a maximum value food arrival at the seafloor during elevated BAR, thus indicating enhanced remineralization. During the PETM, at all 3 sites, increases in barite coincided with reduced BFAR. Similar trends were observed during ETM2 at Sites 1263 and 1215, suggesting dramatic changes in remineralization over all hyperthermal events at these sites. Increased remineralization rates could partly account for differences in planktonic and benthic extinction, as observed during the PETM.

  8. Fine-structured aluminium products with controllable texture by selective laser melting of pre-alloyed AlSi10Mg powder

    International Nuclear Information System (INIS)

    Thijs, Lore; Kempen, Karolien; Kruth, Jean-Pierre; Van Humbeeck, Jan

    2013-01-01

    Graphical abstract: -- Abstract: This study shows that AlSi10Mg parts with an extremely fine microstructure and a controllable texture can be obtained through selective laser melting (SLM). Selective laser melting creates complex functional products by selectively melting powder particles of a powder bed layer after layer using a high-energy laser beam. The high-energy density applied to the material and the additive character of the process result in a unique material structure. To investigate this material structure, cube-shaped SLM parts were made using different scanning strategies and investigated by microscopy, X-ray diffraction and electron backscattered diffraction. The experimental results show that the high thermal gradients occurring during SLM lead to a very fine microstructure with submicron-sized cells. Consequently, the AlSi10Mg SLM products have a high hardness of 127 ± 3 Hv0.5 even without the application of a precipitation hardening treatment. Furthermore, due to the unique solidification conditions and the additive character of the process, a morphological and crystallographic texture is present in the SLM parts. Thanks to the knowledge gathered in this paper on how this texture is formed and how it depends on the process parameters, this texture can be controlled. A strong fibrous 〈1 0 0〉 texture can be altered into a weak cube texture along the building and scanning directions when a rotation of 90° of the scanning vectors within or between the layers is applied

  9. Iron metal production in silicate melts through the direct reduction of Fe/II/ by Ti/III/, Cr/II/, and Eu/II/. [in lunar basalts

    Science.gov (United States)

    Schreiber, H. D.; Balazs, G. B.; Shaffer, A. P.; Jamison, P. L.

    1982-01-01

    The production of metallic iron in silicate melts by chemical reactions of Ti(3+), Cr(2+), and Eu(2+) with Fe(2+) is demonstrated under experimental conditions in a simplified basaltic liquid. These reactions form a basis for interpreting the role of isochemical valency exchange models in explanations for the reduced nature of lunar basalts. The redox couples are individually investigated in the silicate melt to ascertain reference redox ratios that are independent of mutual interactions. These studies also provide calibrations of spectral absorptions of the Fe(2+) and Ti(2+) species in these glasses. Subsequent spectrophotometric analyses of Fe(2+) and Ti(2+) in glasses doped with both iron and titanium and of Fe(2+) in glasses doped with either iron and chromium or iron and europium ascertain the degree of mutual interactions in these dual-doped glasses.

  10. Continuous production of fenofibrate solid lipid nanoparticles by hot-melt extrusion technology: a systematic study based on a quality by design approach.

    Science.gov (United States)

    Patil, Hemlata; Feng, Xin; Ye, Xingyou; Majumdar, Soumyajit; Repka, Michael A

    2015-01-01

    This contribution describes a continuous process for the production of solid lipid nanoparticles (SLN) as drug-carrier systems via hot-melt extrusion (HME). Presently, HME technology has not been used for the manufacturing of SLN. Generally, SLN are prepared as a batch process, which is time consuming and may result in variability of end-product quality attributes. In this study, using Quality by Design (QbD) principles, we were able to achieve continuous production of SLN by combining two processes: HME technology for melt-emulsification and high-pressure homogenization (HPH) for size reduction. Fenofibrate (FBT), a poorly water-soluble model drug, was incorporated into SLN using HME-HPH methods. The developed novel platform demonstrated better process control and size reduction compared to the conventional process of hot homogenization (batch process). Varying the process parameters enabled the production of SLN below 200 nm. The dissolution profile of the FBT SLN prepared by the novel HME-HPH method was faster than that of the crude FBT and a micronized marketed FBT formulation. At the end of a 5-h in vitro dissolution study, a SLN formulation released 92-93% of drug, whereas drug release was approximately 65 and 45% for the marketed micronized formulation and crude drug, respectively. Also, pharmacokinetic study results demonstrated a statistical increase in Cmax, Tmax, and AUC0-24 h in the rate of drug absorption from SLN formulations as compared to the crude drug and marketed micronized formulation. In summary, the present study demonstrated the potential use of hot-melt extrusion technology for continuous and large-scale production of SLN.

  11. Drop-on-Demand System for Manufacturing of Melt-based Solid Oral Dosage: Effect of Critical Process Parameters on Product Quality.

    Science.gov (United States)

    Içten, Elçin; Giridhar, Arun; Nagy, Zoltan K; Reklaitis, Gintaras V

    2016-04-01

    The features of a drop-on-demand-based system developed for the manufacture of melt-based pharmaceuticals have been previously reported. In this paper, a supervisory control system, which is designed to ensure reproducible production of high quality of melt-based solid oral dosages, is presented. This control system enables the production of individual dosage forms with the desired critical quality attributes: amount of active ingredient and drug morphology by monitoring and controlling critical process parameters, such as drop size and product and process temperatures. The effects of these process parameters on the final product quality are investigated, and the properties of the produced dosage forms characterized using various techniques, such as Raman spectroscopy, optical microscopy, and dissolution testing. A crystallization temperature control strategy, including controlled temperature cycles, is presented to tailor the crystallization behavior of drug deposits and to achieve consistent drug morphology. This control strategy can be used to achieve the desired bioavailability of the drug by mitigating variations in the dissolution profiles. The supervisor control strategy enables the application of the drop-on-demand system to the production of individualized dosage required for personalized drug regimens.

  12. An aerial radiological survey of the Oak Ridge Reservation, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Maurer, R.J.

    1993-04-01

    An aerial radiological survey of the Oak Ridge Reservation (ORR) and surrounding area in Oak Ridge, Tennessee, was conducted during the period March 30 to April 14,1992. The purpose of the survey was to measure and document the terrestrial radiological environment of the Oak Ridge Reservation for use in environmental management programs and emergency response planning. The aerial survey was flown at an altitude of 150 feet (46 meters) along a series of parallel lines 250 feet (76 meters) apart and included X-10 (Oak Ridge National Laboratory), K-25 (former Gaseous Diffusion Plant), Y-12 (Weapons Production Plant), the Freels Bend Area and Oak Ridge Institute for Science and Education, the East Fork Poplar Creek (100-year floodplain extending from K-25 to Y-12), Elza Gate (former uranium ore storage site located in the city of Oak Ridge), Parcel A, the Clinch River (river banks extending from Melton Hill Dam to the city of Kingston), and the CSX Railroad Tracks (extending from Y-12 to the city of Oak Ridge). The survey encompassed approximately 55 square miles (1 41 square kilometers) of the Oak Ridge Reservation and surrounding area

  13. Did the Chicxulub meteorite impact trigger eruptions at mid-ocean ridges globally?

    Science.gov (United States)

    Byrnes, J. S.; Karlstrom, L.

    2017-12-01

    Are there causal links between the eruption of large igneous provinces, meteorite impacts, and mass extinctions? Recent dating suggests that state shifts in Deccan Traps eruptions, including erupted volumes, feeder dike orientations, and magma chemistry, occurred shortly after the Chicxulub impact. A proposed explanation for this observation is an increase in upper mantle permeability following the Chicxulub impact that accelerated the pace of Deccan volcanism [Richards et al., 2015]. If such triggering occurred, at global distances not associated with the impact antipode, it is reasonable to hypothesize that other reservoirs of stored melt may have been perturbed as well. We present evidence that mid-ocean ridge activity increased globally following the impact. Anomalously concentrated free-air gravity and sea-floor topographic roughness suggest volumes of excess oceanic ridge magmatism in the range of 2 x 105 to 106 km3 within 1 Myrs of the Chicxulub impact. This signal is only clearly observed for half-spreading rates above 35 mm/yr, possibly because crust formed at slower spreading rates is too complex to preserve the signal. Because similar anomalies are observed separately in the Indian and Pacific Oceans, and because the timing of the signal does not clearly align with changes in spreading rates, we do not favor plume activity as an explanation. Widespread mobilization of existing mantle melt by post-impact seismic radiation, and subsequent emplacement of melt as crustal intrusions and eruptions, can explain the volume and distribution of anomalous crust without invoking impact-induced melt production. Although the mechanism for increasing permeability is not clear at either Deccan or mid-ocean ridges, these results support the hypothesis that the causes and consequences of the Deccan Traps, Chicxulub impact, and K-Pg mass extinction should not be considered in isolation. We conclude by discussing several enigmatic observations from K-Pg time that heightened

  14. Ridge Regression Signal Processing

    Science.gov (United States)

    Kuhl, Mark R.

    1990-01-01

    The introduction of the Global Positioning System (GPS) into the National Airspace System (NAS) necessitates the development of Receiver Autonomous Integrity Monitoring (RAIM) techniques. In order to guarantee a certain level of integrity, a thorough understanding of modern estimation techniques applied to navigational problems is required. The extended Kalman filter (EKF) is derived and analyzed under poor geometry conditions. It was found that the performance of the EKF is difficult to predict, since the EKF is designed for a Gaussian environment. A novel approach is implemented which incorporates ridge regression to explain the behavior of an EKF in the presence of dynamics under poor geometry conditions. The basic principles of ridge regression theory are presented, followed by the derivation of a linearized recursive ridge estimator. Computer simulations are performed to confirm the underlying theory and to provide a comparative analysis of the EKF and the recursive ridge estimator.

  15. Melting of contaminated metallic waste

    International Nuclear Information System (INIS)

    Lee, Y.-S.; Cheng, S.-Y.; Kung, H.-T.; Lin, L.-F.

    2004-01-01

    Approximately 100 tons of contaminated metallic wastes were produced each year due to maintenance for each TPC's nuclear power reactor and it was roughly estimated that there will be 10,000 tons of metallic scraps resulted from decommissioning of each reactor in the future. One means of handling the contaminated metal is to melt it. Melting process owns not only volume reduction which saves the high cost of final disposal but also resource conservation and recycling benefits. Melting contaminated copper and aluminum scraps in the laboratory scale have been conducted at INER. A total of 546 kg copper condenser tubes with a specific activity of about 2.7 Bq/g was melted in a vacuum induction melting facility. Three types of products, ingot, slag and dust were derived from the melting process, with average activities of 0.10 Bq/g, 2.33 Bq/g and 84.3 Bq/g respectively. After the laboratory melting stage, a pilot plant with a 500 kg induction furnace is being designed to melt the increasingly produced contaminated metallic scraps from nuclear facilities and to investigate the behavior of different radionuclides during melting. (author)

  16. Authenticity analyses of Rhizoma Paridis using barcoding coupled with high resolution melting (Bar-HRM) analysis to control its quality for medicinal plant product.

    Science.gov (United States)

    Duan, Bao-Zhong; Wang, Ya-Ping; Fang, Hai-Lan; Xiong, Chao; Li, Xi-Wen; Wang, Ping; Chen, Shi-Lin

    2018-01-01

    Rhizoma Paridis (Chonglou) is a commonly used and precious traditional Chinese medicine. Paris polyphylla Smith var. yunnanensis (Franch.) Hand. -Mazz. and Paris polyphylla Smith var . chinensis (Franch.) Hara are the two main sources of Chonglou under the monograph of Rhizoma Paridis in Chinese Pharmacopoeia. In the local marketplace, however, this medicine is prone to be accidentally contaminated, deliberately substituted or admixed with other species that are similar to Rhizoma Paridis in shape and color. Consequently, these adulterations might compromise quality control and result in considerable health concerns for consumers. This study aims to develop a rapid and sensitive method for accurate identification of Rhizoma Paridis and its common adulterants. DNA barcoding coupled with high resolution melting analysis was applied in this research to distinguish Rhizoma Paridis from its adulteration. The internal transcribed spacer 2 (ITS2) barcode was selected for HRM analysis to produce standard melting profile of the selected species. DNA of the tested herbal medicines was isolated and their melting profiles were generated and compared with the standard melting profile of P. polyphylla var. chinensis . The results indicate that the ITS2 molecular regions coupled with HRM analysis can effectively differentiate nine herbal species, including two authentic origins of Chonglou and their seven common adulterants. Ten herbal medicines labeled "Chonglou" obtained from a local market were collected and identified with our methods, and their sequence information was analyzed to validate the accuracy of HRM analysis. DNA barcoding coupled with HRM analysis is a accurate, reliable, rapid, cost-effective and robust tool, which could contribute to the quality control of Rhizoma Paridis in the supply chain of the natural health product industry (NHP).

  17. Volcanism and hydrothermalism on a hotspot-influenced ridge: Comparing Reykjanes Peninsula and Reykjanes Ridge, Iceland

    Science.gov (United States)

    Pałgan, Dominik; Devey, Colin W.; Yeo, Isobel A.

    2017-12-01

    Current estimates indicate that the number of high-temperature vents (one of the primary pathways for the heat extraction from the Earth's mantle) - at least 1 per 100 km of axial length - scales with spreading rate and should scale with crustal thickness. But up to present, shallow ridge axes underlain by thick crust show anomalously low incidences of high-temperature activity. Here we compare the Reykjanes Ridge, an abnormally shallow ridge with thick crust and only one high-temperature vent known over 900 km axial length, to the adjacent subaerial Reykjanes Peninsula (RP), which is characterized by high-temperature geothermal sites confined to four volcanic systems transected by fissure swarms with young (Holocene) volcanic activity, multiple faults, cracks and fissures, and continuous seismic activity. New high-resolution bathymetry (gridded at 60 m) of the Reykjanes Ridge between 62°30‧N and 63°30‧N shows seven Axial Volcanic Ridges (AVR) that, based on their morphology, geometry and tectonic regime, are analogues for the volcanic systems and fissure swarms on land. We investigate in detail the volcano-tectonic features of all mapped AVRs and show that they do not fit with the previously suggested 4-stage evolution model for AVR construction. Instead, we suggest that AVR morphology reflects the robust or weak melt supply to the system and two (or more) eruption mechanisms may co-exist on one AVR (in contrast to 4-stage evolution model). Our interpretations indicate that, unlike on the Reykjanes Peninsula, faults on and around AVRs do not cluster in orientation domains but all are subparallel to the overall strike of AVRs (orthogonal to spreading direction). High abundance of seamounts shows that the region centered at 62°47‧N and 25°04‧W (between AVR-5 and -6) is volcanically robust while the highest fault density implies that AVR-1 and southern part of AVR-6 rather undergo period of melt starvation. Based on our observations and interpretations we

  18. Oak Ridge Reservation environmental report for 1989

    International Nuclear Information System (INIS)

    Jacobs, V.A.; Wilson, A.R.

    1990-10-01

    This two-volume report, the Oak Ridge Reservation Environmental Report for 1989, is the nineteenth in an annual series that began in 1971. It reports the results of a comprehensive, year-round program to monitor the impact of operations at the three major US Department of Energy (DOE) production and research installations in Oak Ridge on the immediate areas' and surrounding region's groundwater and surface waters, soil, air quality, vegetation and wildlife, and through these multiple and varied pathways, the resident human population. Information is presented for the environmental monitoring Quality Assurance (QA) Program, audits and reviews, waste management activities, land special environmental studies. Data are included for the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory (ORNL), and Oak Ridge Gaseous Diffusion Plant (ORGDP). Volume 1 presents narratives, summaries, and conclusions based on environmental monitoring at the three DOE installations and in the surrounding environs during calendar year (CY) 1989. Volume 1 is intended to be a ''stand-alone'' report about the Oak Ridge Reservation (ORR) for the reader who does not want an in-depth review of 1989 data. Volume 2 presents the detailed data from which these conclusions have been drawn and should be used in conjunction with Volume 1

  19. Oak Ridge Reservation environmental report for 1989

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, V.A.; Wilson, A.R. (eds.)

    1990-10-01

    This two-volume report, the Oak Ridge Reservation Environmental Report for 1989, is the nineteenth in an annual series that began in 1971. It reports the results of a comprehensive, year-round program to monitor the impact of operations at the three major US Department of Energy (DOE) production and research installations in Oak Ridge on the immediate areas' and surrounding region's groundwater and surface waters, soil, air quality, vegetation and wildlife, and through these multiple and varied pathways, the resident human population. Information is presented for the environmental monitoring Quality Assurance (QA) Program, audits and reviews, waste management activities, land special environmental studies. Data are included for the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory (ORNL), and Oak Ridge Gaseous Diffusion Plant (ORGDP). Volume 1 presents narratives, summaries, and conclusions based on environmental monitoring at the three DOE installations and in the surrounding environs during calendar year (CY) 1989. Volume 1 is intended to be a stand-alone'' report about the Oak Ridge Reservation (ORR) for the reader who does not want an in-depth review of 1989 data. Volume 2 presents the detailed data from which these conclusions have been drawn and should be used in conjunction with Volume 1.

  20. A micro-scale investigation of melt production and extraction in the upper mantle based on silicate melt pockets in ultramafic xenoliths from the Bakony-Balaton Highland Volcanic Field (Western Hungary)

    DEFF Research Database (Denmark)

    Bali, Eniko; Zanetti, A.; Szabo, C.

    2008-01-01

    Mantle xenoliths in Neogene alkali basalts of the Bakony-Balaton Highland Volcanic Field (Western Hungary) frequently have melt pockets that contain silicate minerals, glass, and often carbonate globules. Textural, geochemical and thermobarometric data indicate that the melt pockets formed at rel...

  1. The calcium fluoride effect on properties of cryolite melts feasible for low-temperature production of aluminum and its alloys

    Science.gov (United States)

    Tkacheva, O.; Dedyukhin, A.; Redkin, A.; Zaikov, Yu.

    2017-07-01

    The CaF2 effect on the liquidus temperature, electrical conductivity and alumina solubility in the potassium-sodium and potassium-lithium cryolite melts with cryolite ratio (CR = (nKF+nMF)/nAlF3, M = Li, Na) 1.3 was studied. The liquidus temperature in the quisi-binary system [KF-LiF-AlF3]-CaF2 changes with the same manner as in the [KF-NaF-AlF3]-CaF2. The electrical conductivity in the KF-NaF-AlF3-CaF2 melt decreases with increasing the CaF2 content, but it slightly raises with the first small addition of CaF2 into the KF-LiF-AlF3-CaF2 melts, enriched with KF, which was explained by the increased K+ ions mobility due to their relatively low ionic potential. The contribution of the Li+ cations in conductivity of the KF-LiF-AlF3-CaF2 electrolyte is not noteworthy. The Al2O3 solubility in the KF-NaF-AlF3 electrolyte rises with the increasing KF content, but the opposite tendency is observed in the cryolite mixtures containing CaF2. The insoluble compounds - KCaAl2F9 or KCaF3 - formed in the molten mixtures containing potassium and calcium ions endorse the increase of the liquidus temperature. The calcium fluoride effect on the side ledge formation in the electrolytic cell during low-temperature aluminum electrolysis is discussed.

  2. Dynamical instability produces transform faults at mid-ocean ridges.

    Science.gov (United States)

    Gerya, Taras

    2010-08-27

    Transform faults at mid-ocean ridges--one of the most striking, yet enigmatic features of terrestrial plate tectonics--are considered to be the inherited product of preexisting fault structures. Ridge offsets along these faults therefore should remain constant with time. Here, numerical models suggest that transform faults are actively developing and result from dynamical instability of constructive plate boundaries, irrespective of previous structure. Boundary instability from asymmetric plate growth can spontaneously start in alternate directions along successive ridge sections; the resultant curved ridges become transform faults within a few million years. Fracture-related rheological weakening stabilizes ridge-parallel detachment faults. Offsets along the transform faults change continuously with time by asymmetric plate growth and discontinuously by ridge jumps.

  3. Ridge and Furrow Fields

    DEFF Research Database (Denmark)

    Møller, Per Grau

    2016-01-01

    Ridge and furrow is a specific way of ploughing which makes fields of systematic ridges and furrows like a rubbing washboard. They are part of an overall openfield system, but the focus in this paper is on the functionality of the fields. There are many indications that agro-technological reasons...... systems and the establishment of basic structures like villages (with churches) and townships and states (in northern Europe). The fields can be considered as a resilient structure lasting for 800 years, along with the same basic physical structures in society....

  4. Resource Conservation and Recovery Act (RCRA) Part B Permit Application for Production Associated Units at the Oak Ridge Y-12 Plant

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    This is the RCRA required permit application for Radioactive and Hazardous Waste Management at the Oak Ridge Y-12 Plant for the following units: Building 9206 Container Storage Unit; Building 9212 Container Storage Unit; Building 9720-12 Container Storage Unit; Cyanide Treatment Unit. All four of these units are associated with the recovery of enriched uranium and other metals from wastes generated during the processing of nuclear materials.

  5. Resource Conservation and Recovery Act (RCRA) Part B Permit Application for Production Associated Units at the Oak Ridge Y-12 Plant

    International Nuclear Information System (INIS)

    1994-09-01

    This is the RCRA required permit application for Radioactive and Hazardous Waste Management at the Oak Ridge Y-12 Plant for the following units: Building 9206 Container Storage Unit; Building 9212 Container Storage Unit; Building 9720-12 Container Storage Unit; Cyanide Treatment Unit. All four of these units are associated with the recovery of enriched uranium and other metals from wastes generated during the processing of nuclear materials

  6. Partial melting of lower oceanic crust gabbro: Constraints from poikilitic clinopyroxene primocrysts

    Science.gov (United States)

    Leuthold, Julien; Lissenberg, C. Johan; O'Driscoll, Brian; Karakas, Ozge; Falloon, Trevor; Klimentyeva, Dina N.; Ulmer, Peter

    2018-03-01

    Successive magma batches underplate, ascend, stall and erupt along spreading ridges, building the oceanic crust. It is therefore important to understand the processes and conditions under which magma differentiates at mid ocean ridges. Although fractional crystallization is considered to be the dominant mechanism for magma differentiation, open-system igneous complexes also experience Melting-Assimilation-Storage-Hybridization (MASH, Hildreth and Moorbath, 1988) processes. Here, we examine crystal-scale records of partial melting in lower crustal gabbroic cumulates from the slow-spreading Atlantic oceanic ridge (Kane Megamullion; collected with Jason ROV) and the fast-spreading East Pacific Rise (Hess Deep; IODP expedition 345). Clinopyroxene oikocrysts in these gabbros preserve marked intra-crystal geochemical variations that point to crystallization-dissolution episodes of the gabbro eutectic assemblage. Kane Megamullion and Hess Deep clinopyroxene core1 primocrysts and their plagioclase inclusions indicate crystallization from high temperature basalt (>1160 and >1200°C, respectively), close to clinopyroxene saturation temperature (fundamental mechanisms for generating the wide compositional variation observed in mid-ocean ridge basalts. We furthermore propose that such processes operate at both slow- and fast-spreading ocean ridges. Thermal numerical modelling shows that the degree of lower crustal partial melting at slow-spreading ridges can locally increase up to 50%, but the overall crustal melt volume is low (less than ca. 5% of total mantle-derived and crustal melts; ca. 20% in fast-spreading ridges).

  7. The induction furnace as a melting facility in steel production. Pt. 1. Features of induction furnaces used in steel production; Der Induktionsofen als Schmelzaggregat fuer die Stahlerzeugung. T. 1. Merkmale von Induktionsoefen in der Stahlerzeugung

    Energy Technology Data Exchange (ETDEWEB)

    Chaabet, Mohamed; Doetsch, Erwin [ABP Induction Systems GmbH, Dortmund (Germany)

    2011-12-15

    Global steel output has now been growing extremely rapidly for a prolonged time; in the past ten years alone, annual production has risen from 851 million t/a (in 2001) to 1417 million t/a (2010), as a result, primarily, of growth in China. Electric steel production using the electric arc furnace as the classical melting facility is around 45 % world-wide, with a rising trend (but excluding the special case of China, where oxygen-route steel holds a 90 % share of production). Following the development of induction technology and inverter outputs of over 40 MW for crucible furnaces with capacities of above 65 t, the induction furnace is now available as an alternative electrical melting installation for use in smaller mini steel mills. The benefits of this technology can be found in high feed-material efficiencies and low environmental and workplace burdens, in addition to the absence of electrode costs and the only modest demands made on the power-supply grid. These features of the induction furnace and their special significance for steel production are examined in Part 1 of this article. The second part of the article then focuses on examples of the use of induction furnaces in the steelmaking plant. (orig.)

  8. In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 1: Results of treatability study

    International Nuclear Information System (INIS)

    Spalding, B.P.; Naney, M.T.; Cline, S.R.; Bogle, M.A.

    1997-12-01

    A treatability study was initiated in October 1993 to apply in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was later extended to include all of Pit 1 and was performed to support a possible Interim Record of Decision or removal action for closure of one or more of the seepage pits and trenches beginning as early as FY 1997. This treatability study was carried out to establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability for the overlap of melt settings which will be necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of 137 Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. In April 1996 an expulsion of an estimated 10% of the 196 Mg (216 tons) melt body occurred resulting in significant damage to ISV equipment and, ultimately, led to an indefinite suspension of further ISV operations at Pit 1. This report summarizes the technical accomplishments and status of the project in fulfilling these objectives through September 1997

  9. In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 1: Results of treatability study

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, B.P.; Naney, M.T.; Cline, S.R.; Bogle, M.A. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Tixier, J.S. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-12-01

    A treatability study was initiated in October 1993 to apply in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was later extended to include all of Pit 1 and was performed to support a possible Interim Record of Decision or removal action for closure of one or more of the seepage pits and trenches beginning as early as FY 1997. This treatability study was carried out to establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability for the overlap of melt settings which will be necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of {sup 137}Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. In April 1996 an expulsion of an estimated 10% of the 196 Mg (216 tons) melt body occurred resulting in significant damage to ISV equipment and, ultimately, led to an indefinite suspension of further ISV operations at Pit 1. This report summarizes the technical accomplishments and status of the project in fulfilling these objectives through September 1997.

  10. Custom-made titanium devices as membranes for bone augmentation in implant treatment: Modeling accuracy of titanium products constructed with selective laser melting.

    Science.gov (United States)

    Otawa, Naruto; Sumida, Tomoki; Kitagaki, Hisashi; Sasaki, Kiyoyuki; Fujibayashi, Shunsuke; Takemoto, Mitsuru; Nakamura, Takashi; Yamada, Tomohiro; Mori, Yoshihide; Matsushita, Tomiharu

    2015-09-01

    The purpose of this study was to verify the modeling accuracy of various products, and to produce custom-made devices for bone augmentation in individual patients requiring implantation. Two-(2D) and three-dimensional (3D) specimens and custom-made devices that were designed as membranes for guided bone regeneration (GBR) were produced using a computer-aided design (CAD) and rapid prototyping (RP) method. The CAD design was produced using a 3D printing machine and selective laser melting (SLM) with pure titanium (Ti) powder. The modeling accuracy was evaluated with regard to: the dimensional accuracy of the 2D and 3D specimens; the accuracy of pore structure of the 2D specimens; the accuracy of porosity of the 3D specimens; and the error between CAD design and the scanned real product by overlapped images. The accuracy of the 2D and 3D specimens indicated precise results in various parameters, which were tolerant in ISO 2768-1. The error of overlapped images between the CAD and scanned data indicated that accuracy was sufficient for GBR. In integrating area of all devices, the maximum and average error were 292 and 139 μm, respectively. High modeling accuracy can be achieved in various products using the CAD/RP-SLM method. These results suggest the possibility of clinical applications. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  11. Mantle Convection beneath the Aegir Ridge, a Shadow in the Iceland Hotspot

    Science.gov (United States)

    Howell, S. M.; Ito, G.; Breivik, A. J.; Hanan, B. B.; Mjelde, R.; Sayit, K.; Vogt, P. R.

    2012-12-01

    The Iceland Hotspot has produced extensive volcanism spanning much of the ocean basin between Greenland and Norway, forming one of the world's largest igneous provinces. However, an apparent igneous "shadow" in hotspot activity is located at the fossil Aegir Ridge, which formed anomalously thin crust, despite this ridge being near the Iceland hotspot when it was active. The Aegir Ridge accommodated seafloor spreading northeast of present-day Iceland from the time of continental breakup at ~55 Ma until ~25 Ma, at which point spreading shifted west to the Kolbeinsey Ridge. To address the cause of the anomalously thin crust produced by the Aegir Ridge, we use three-dimensional numerical models to simulate the interaction between a mantle plume beneath the Iceland hotspot, rifting continental lithosphere, and the time-evolving North Atlantic ridge system. Two end-member hypotheses were investigated: (1) Material emanating from the Iceland mantle plume was blocked from reaching the Aegir Ridge by the thick lithosphere of the Jan Mayen Microcontinent as the Kolbeinsey Ridge began rifting it from Greenland at ~30 Ma, just east of the plume center; (2) Plume material was not blocked and did reach the Aegir Ridge, but had already experienced partial melting closer to the hotspot. This material was then unable to produce melt volumes at the Aegir Ridge comparable to those of pristine mantle. To test these hypotheses, we vary the volume flux and viscosity of the plume, and identify which conditions do and do not lead to the Aegir Ridge forming anomalously thin crust. Results show that the combination of plume material being drawn into the lithospheric channels beneath the Reykjanes Ridge and Kolbeinsey Ridge after their respective openings, and the impedance of plume flow by the Jan Mayen Microcontinent (hypothesis 1), can deprive the Aegir Ridge of plume influence. This leads to low crustal thicknesses that are comparable to those observed. We have yet to produce a model

  12. Features of melting of indium monohalides

    Energy Technology Data Exchange (ETDEWEB)

    Dmitriev, V S; Smirniv, V A [AN SSSR, Chernogolovka. Inst. Fiziki Tverdogo Tela

    1980-12-01

    The character of InCl, InBr and InI melting is investigated by the methods of DTA, calorimetry, conductometry and chemical analysis. Partial decomposition of monohalogenides during melting according to the reactions of disproportionation is shown. The presence of disproportionation products (In/sup 0/ and In/sup 3 +/) is manifested in the properties of solid monohalogenides, prepared by the crystallization from melt, in their photosensitivity and electroconductivity.

  13. PRODUCTION OF CATHODES AND HIGH PURITY TARGETS OF CHEMICALLY ACTIVE METALS BY MEANS OF ELECTRONIC-RAY MELTING

    Directory of Open Access Journals (Sweden)

    A. V. Alifanov

    2007-01-01

    Full Text Available The technical process of production and restoration of worn cathodes and targets of chemically active metals (Ti, Zr, V and others with the help of cathode ray in vacuum is developed. Regenerating of worn cathodes, targets is carried out by means of insertion in chill of worn base and successive cathode ray deposition on certain places of required quantity of metal (from 2 till 50mm.

  14. Oak Ridge reservation land-use plan

    Energy Technology Data Exchange (ETDEWEB)

    Bibb, W. R.; Hardin, T. H.; Hawkins, C. C.; Johnson, W. A.; Peitzsch, F. C.; Scott, T. H.; Theisen, M. R.; Tuck, S. C.

    1980-03-01

    This study establishes a basis for long-range land-use planning to accommodate both present and projected DOE program requirements in Oak Ridge. In addition to technological requirements, this land-use plan incorporates in-depth ecological concepts that recognize multiple uses of land as a viable option. Neither environmental research nor technological operations need to be mutually exclusive in all instances. Unique biological areas, as well as rare and endangered species, need to be protected, and human and environmental health and safety must be maintained. The plan is based on the concept that the primary use of DOE land resources must be to implement the overall DOE mission in Oak Ridge. This document, along with the base map and overlay maps, provides a reasonably detailed description of the DOE Oak Ridge land resources and of the current and potential uses of the land. A description of the land characteristics, including geomorphology, agricultural productivity and soils, water courses, vegetation, and terrestrial and aquatic animal habitats, is presented to serve as a resource document. Essentially all DOE land in the Oak Ridge area is being fully used for ongoing DOE programs or has been set aside as protected areas.

  15. Industrial production and purification of 32P by sulfur irradiation with partially moderated neutron fluxes and target melting

    International Nuclear Information System (INIS)

    Alanis, J.; Navarrete, M.

    2007-01-01

    Target purification of S α is carried out by distillation at 444±2 deg C under N atmosphere and diluting the vapors in CS 2 . The solution is filtered through fiberglass, Teflon and cellulose to obtain S α by CS 2 evaporation. Once 30 g of this target are irradiated with fast neutron fluxes from 4.5 to 7.4 x 10 12 n x cm -2 x s -1 from 6 to 12 hours, the nuclear reaction 32 S(n,p) 32 P takes place. So, the irradiated S α sample is placed in a Pyrex container situated inside a furnace as the most important piece of equipment in one aluminum and Lucite glove box. The distillation of irradiated sulfur takes place at 444±2 deg C under N atmosphere during 1-2 hours. The vapors are connected to a sulfur diluter containing 20% CS 2 aqueous solution, followed by an activated carbon filter and the two similar additional sulfur diluters. Once cooled, the distillation chamber keeps the radioactive, carrier-free 32 P stuck to the wall. Then 25-50 ml of 0.1N HCl acid was injected by suction and heated again at 110±2 deg C during 1 hour. The corresponding chemical reaction takes place and the labeled H 3 32 PO 4 solution is produced. In such a way, industrial production of 32 P labeled molecules has started in Mexico, with an initial production of 3700-5550 MBq per week. (author)

  16. Structuring and calorie control of bakery products by templating batter with ultra melt-resistant food-grade hydrogel beads.

    Science.gov (United States)

    Thompson, Benjamin R; Horozov, Tommy S; Stoyanov, Simeon D; Paunov, Vesselin N

    2017-08-01

    We report the use of a temperature insensitive, food-grade hydrogel to reduce the caloric density of pancakes that were prepared at temperatures much higher than the boiling point of water. This cheap, facile method utilises a mixed agar-methylcellulose hydrogel, which was blended to produce a slurry of hydrogel microbeads. The pancake batter was mixed with a controlled volume percentage of slurry of hydrogel beads and cooked. From bomb calorimetry experiments, the composites were found to have a reduced caloric density that reflects the volume percentage of hydrogel beads mixed with the batter. Using this procedure, we were able to reduce the caloric density of pancakes by up to 23 ± 3% when the volume percentage of hydrogel beads initially used was 25%. The method is not limited to pancakes and could potentially be applied to various other food products. The structure and morphology of the freeze-dried pancakes and pancake-hydrogel composites were investigated and pores of a similar size to the hydrogel beads were found, confirming that the gel beads maintained their structure during the cooking process. There is scope for further development of this method by the encapsulation of nutritionally beneficial or flavour enhancing ingredients within the hydrogel beads.

  17. Niobium interaction with chloride-carbonate melts

    International Nuclear Information System (INIS)

    Kuznetsov, S.A.; Kuznetsova, S.V.

    1996-01-01

    Niobium interaction with chloride-carbonate melt NaCl-KCl-K 2 CO 3 (5 mass %) in the temperature range of 973-1123 K has been studied. The products and niobium corrosion rate have been ascertained, depending on the temperature of melt and time of allowance. Potentials of niobium corrosion have been measured. Refs. 11, figs. 3, tabs. 2

  18. Melting under shock compression

    International Nuclear Information System (INIS)

    Bennett, B.I.

    1980-10-01

    A simple model, using experimentally measured shock and particle velocities, is applied to the Lindemann melting formula to predict the density, temperature, and pressure at which a material will melt when shocked from room temperature and zero pressure initial conditions

  19. Comparisons of seismic and electromagnetic structures of the MELT area

    Science.gov (United States)

    Evans, R. L.; Hirth, G.; Forsyth, D.; Baba, K.; Chave, A.

    2003-04-01

    Both seismic and electromagnetic (EM) models from the MELT experiment show similar broad scale features in the mantle beneath the Southern EPR. In all EM models, the conductivity in the upper 50-60˜km is considerably higher to the west of the ridge than to the east. Similarly, seismic models of short period Love waves are asymmetric in velocity structure, with slower velocities to the west of the ridge within the upper 60˜km. Body wave data suggest a similar asymmetry, although the depth extent is not as well defined. West of the ridge, both the higher conductivities and lower velocities have been attributed to the presence of a small melt fraction, although the anomalous regions estimated from different techniques do not entirely agree. To the east, there is a rapid increase in resistivity and S-wave velocity, indicating that within 25˜km of the axis the mantle above 70˜km is both dry and melt-free. Further away from the ridge, the boundary between a conductive asthenospheric mantle and a resistive overlying mantle flattens, at a depth around 60-80˜km. Rayleigh wave inversions also show fairly flat velocity contours with a broad minimum centered at 60-80˜km. Both of these features are consistent with a transition from dry to damp mantle. Also away from the ridge, EM data, shear-wave splitting, and Rayleigh waves all require an azimuthally anisotropic mantle consistent with the a-axis of olivine being preferentially oriented horizontally and perpendicular to the ridge. Anisotropy in EM data suggests damp mantle conditions in the 100-200˜km depth range, with enhanced conduction along the a-axis of olivine. Rayleigh waves are most sensitive to shallower structure and require anisotropy in the upper 70˜km. In the uppermost 40˜km, the most conductive and lowest velocity regions are close to the axis but offset 5-10˜km to the west. Some anisotropic inversions recover a vertically conductive feature that could be interpreted as a few percent melt distributed in

  20. Integrated hot-melt extrusion - injection molding continuous tablet manufacturing platform: Effects of critical process parameters and formulation attributes on product robustness and dimensional stability.

    Science.gov (United States)

    Desai, Parind M; Hogan, Rachael C; Brancazio, David; Puri, Vibha; Jensen, Keith D; Chun, Jung-Hoon; Myerson, Allan S; Trout, Bernhardt L

    2017-10-05

    This study provides a framework for robust tablet development using an integrated hot-melt extrusion-injection molding (IM) continuous manufacturing platform. Griseofulvin, maltodextrin, xylitol and lactose were employed as drug, carrier, plasticizer and reinforcing agent respectively. A pre-blended drug-excipient mixture was fed from a loss-in-weight feeder to a twin-screw extruder. The extrudate was subsequently injected directly into the integrated IM unit and molded into tablets. Tablets were stored in different storage conditions up to 20 weeks to monitor physical stability and were evaluated by polarized light microscopy, DSC, SEM, XRD and dissolution analysis. Optimized injection pressure provided robust tablet formulations. Tablets manufactured at low and high injection pressures exhibited the flaws of sink marks and flashing respectively. Higher solidification temperature during IM process reduced the thermal induced residual stress and prevented chipping and cracking issues. Polarized light microscopy revealed a homogeneous dispersion of crystalline griseofulvin in an amorphous matrix. DSC underpinned the effect of high tablet residual moisture on maltodextrin-xylitol phase separation that resulted in dimensional instability. Tablets with low residual moisture demonstrated long term dimensional stability. This study serves as a model for IM tablet formulations for mechanistic understanding of critical process parameters and formulation attributes required for optimal product performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Fission products behavior in molten fluoride salts: Speciation of La{sup 3+} and Cs{sup +} in melts containing oxide ions

    Energy Technology Data Exchange (ETDEWEB)

    Rollet, Anne-Laure [CEMHTI, Conditions Extremes et Materiaux: Haute Temperature et Irradiation, CNRS, Universite d' Orleans, 1D avenue de la recherche scientifique, 45071 Orleans cedex 2 (France); PECSA, Physico-chimie des Electrolytes, Colloiedes et Sciences Analytiques, CNRS-UPMC-ESPCI, 4 place Jussieu, 75005 Paris (France); Veron, Emmanuel [CEMHTI, Conditions Extremes et Materiaux: Haute Temperature et Irradiation, CNRS, Universite d' Orleans, 1D avenue de la recherche scientifique, 45071 Orleans cedex 2 (France); Bessada, Catherine, E-mail: catherine.bessada@cnrs-orleans.fr [CEMHTI, Conditions Extremes et Materiaux: Haute Temperature et Irradiation, CNRS, Universite d' Orleans, 1D avenue de la recherche scientifique, 45071 Orleans cedex 2 (France)

    2012-10-15

    Graphical abstract: - Abstract: In this paper we address the effects of fission products on the speciation in molten fluoride salts. Numerous systems with cross-connections have been investigated in order to better identify the influence of CsF in a fluoride melt containing rare earth and oxides : LaF{sub 3}-AF (A = Li, Na, K, Rb and Cs), LaF{sub 3}-LiF-CsF, LaF{sub 3}-LiF-CaF{sub 2}, LaF{sub 3}-LiF-CaO, LaF{sub 3}-LiF-CaO-CsF. In this goal, we performed high temperature NMR experiments and followed in situ the evolution of {sup 19}F, {sup 23}Na, {sup 85}Rb, {sup 133}Cs and {sup 139}La NMR chemical shifts. In LaF{sub 3}-AF-CsF and LaF{sub 3}-AF-CaF{sub 2} systems, the coordination number of lanthanum cation ranges from 6 to 8 depending on the LaF{sub 3} concentration and on the polarizability of the other cations. The addition of oxide (CaO) in the latter mixtures leads to the formation of lanthanum oxyfluoride species that precipitate in LaOF when CaO concentration is increased. The addition of CsF to LaF{sub 3}-LiF-CaO yields to a displacement of the dissolved versus precipitated LaOF proportion.

  2. Greenland ice sheet melt from MODIS and associated atmospheric variability.

    Science.gov (United States)

    Häkkinen, Sirpa; Hall, Dorothy K; Shuman, Christopher A; Worthen, Denise L; DiGirolamo, Nicolo E

    2014-03-16

    Daily June-July melt fraction variations over the Greenland ice sheet (GIS) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) (2000-2013) are associated with atmospheric blocking forming an omega-shape ridge over the GIS at 500 hPa height. Blocking activity with a range of time scales, from synoptic waves breaking poleward (days) to full-fledged blocks (≥5 days), brings warm subtropical air masses over the GIS controlling daily surface temperatures and melt. The temperature anomaly of these subtropical air mass intrusions is also important for melting. Based on the years with the greatest melt (2002 and 2012) during the MODIS era, the area-average temperature anomaly of 2 standard deviations above the 14 year June-July mean results in a melt fraction of 40% or more. Though the summer of 2007 had the most blocking days, atmospheric temperature anomalies were too small to instigate extreme melting. Short-term atmospheric blocking over Greenland contributes to melt episodesAssociated temperature anomalies are equally important for the meltDuration and strength of blocking events contribute to surface melt intensity.

  3. Measuring mandibular ridge reduction

    International Nuclear Information System (INIS)

    Steen, W.H.A.

    1984-01-01

    This thesis investigates the mandibular reduction in height of complete denture wearers and overdenture wearers. To follow this reduction in the anterior region as well as in the lateral sections of the mandible, an accurate and reproducible measuring method is a prerequisite. A radiologic technique offers the best chance. A survey is given of the literature concerning the resorption process after the extraction of teeth. An oblique cephalometric radiographic technique is introduced as a promising method to measure mandibular ridge reduction. The reproducibility and the accuracy of the technique are determined. The reproducibility in the positioning of the mandible is improved by the introduction of a mandibular support which permits a precise repositioning of the edentulous jaw, even after long periods of investigation. (Auth.)

  4. Environmental baseline survey report for West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge and parcel 21D in the vicinity of the East Technology Park, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    King, David A. [Oak Ridge Institute for Science and Education (ORISE), Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program

    2012-11-29

    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy?s (DOE?s) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only no-further-investigation (NFI) reports. Groundwater sampling was also conducted to support a Parcel 21d decision. Based on available data West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, and West Pine Ridge are not impacted by site operations and are not subject to actions per the Federal Facility Agreement (FFA). This determination is supported by visual inspections, records searches and interviews, groundwater conceptual modeling, approved NFI reports, analytical data, and risk analysis results. Parcel 21d data, however, demonstrate impacts from site

  5. Environmental baseline survey report for West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge and parcel 21D in the vicinity of the East Technology Park, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    King, David A.

    2012-01-01

    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy's (DOE's) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only no-further-investigation (NFI) reports. Groundwater sampling was also conducted to support a Parcel 21d decision. Based on available data West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, and West Pine Ridge are not impacted by site operations and are not subject to actions per the Federal Facility Agreement (FFA). This determination is supported by visual inspections, records searches and interviews, groundwater conceptual modeling, approved NFI reports, analytical data, and risk analysis results. Parcel 21d data, however, demonstrate impacts from site

  6. Magmatic tectonic effects of high thermal regime at the site of active ridge subduction: the Chile Triple Junction model

    Science.gov (United States)

    Lagabrielle, Yves; Guivel, Christèle; Maury, René C.; Bourgois, Jacques; Fourcade, Serge; Martin, Hervé

    2000-11-01

    High thermal gradients are expected to be found at sites of subduction of very young oceanic lithosphere and more particularly at ridge-trench-trench (RTT) triple junctions, where active oceanic spreading ridges enter a subduction zone. Active tectonics, associated with the emplacement of two main types of volcanic products, (1) MORB-type magmas, and (2) calc-alkaline acidic magmas in the forearc, also characterize these plate junction domains. In this context, MORB-type magmas are generally thought to derive from the buried active spreading center subducted at shallow depths, whereas the origin of calc-alkaline acidic magmas is more problematic. One of the best constrained examples of ridge-trench interaction is the Chile Triple Junction (CTJ) located southwest of the South American plate at 46°12'S, where the active Chile spreading center enters the subduction zone. In this area, there is a clear correlation between the emplacement of magmatic products and the migration of the triple junction along the active margin. The CTJ lava population is bimodal, with mafic to intermediate lavas (48-56% SiO 2) and acidic lavas ranging from dacites to rhyolites (66-73% SiO 2). Previous models have shown that partial melting of oceanic crust plus 10-20% of sediments, leaving an amphibole- and plagioclase-rich residue, is the only process that may account for the genesis of acidic magmas. Due to special plate geometry in the CTJ area, a given section of the margin may be successively affected by the passage of several ridge segments. We emphasize that repeated passages will lead to the development of very high thermal gradients allowing melting of rocks of oceanic origin at temperatures of 800-900°C and low pressures, corresponding to depths of 10-20 km depth only. In addition, the structure of the CTJ forearc domain is dominated by horizontal displacements and tilting of crustal blocks along a network of strike-slip faults. The occurrence of such a deformed domain implies

  7. Geomorphological investigation of multiphase glacitectonic composite ridge systems in Svalbard

    Science.gov (United States)

    Lovell, Harold; Benn, Douglas I.; Lukas, Sven; Spagnolo, Matteo; Cook, Simon J.; Swift, Darrel A.; Clark, Chris D.; Yde, Jacob C.; Watts, Tom

    2018-01-01

    Some surge-type glaciers on the High-Arctic archipelago of Svalbard have large glacitectonic composite ridge systems at their terrestrial margins. These have formed by rapid glacier advance into proglacial sediments during the active surge phase, creating multicrested moraine complexes. Such complexes can be formed during single surge advances or multiple surges to successively less-extensive positions. The few existing studies of composite ridge systems have largely relied on detailed information on internal structure and sedimentology to reconstruct their formation and links to surge processes. However, natural exposures of internal structure are commonly unavailable, and the creation of artificial exposures is often problematic in fragile Arctic environments. To compensate for these issues, we investigate the potential for reconstructing composite ridge system formation based on geomorphological evidence alone, focusing on clear morphostratigraphic relationships between ridges within the moraine complex and relict meltwater channels/outwash fans. Based on mapping at the margins of Finsterwalderbreen (in Van Keulenfjorden) and Grønfjordbreen (in Grønfjorden), we show that relict meltwater channels that breach outer parts of the composite ridge systems are in most cases truncated upstream within the ridge complex by an inner pushed ridge or ridges at their ice-proximal extents. Our interpretation of this relationship is that the entire composite ridge system is unlikely to have formed during the same glacier advance but is instead the product of multiple advances to successively less-extensive positions, whereby younger ridges are emplaced on the ice-proximal side of older ridges. This indicates that the Finsterwalderbreen composite ridge system has been formed by multiple separate advances, consistent with the cyclicity of surges. Being able to identify the frequency and magnitude of former surges is important as it provides insight into the past behaviour of

  8. Melting of Dense Sodium

    International Nuclear Information System (INIS)

    Gregoryanz, Eugene; Degtyareva, Olga; Hemley, Russell J.; Mao, Ho-kwang; Somayazulu, Maddury

    2005-01-01

    High-pressure high-temperature synchrotron diffraction measurements reveal a maximum on the melting curve of Na in the bcc phase at ∼31 GPa and 1000 K and a steep decrease in melting temperature in its fcc phase. The results extend the melting curve by an order of magnitude up to 130 GPa. Above 103 GPa, Na crystallizes in a sequence of phases with complex structures with unusually low melting temperatures, reaching 300 K at 118 GPa, and an increased melting temperature is observed with further increases in pressure

  9. Ocean Ridges and Oxygen

    Science.gov (United States)

    Langmuir, C. H.

    2014-12-01

    The history of oxygen and the fluxes and feedbacks that lead to its evolution through time remain poorly constrained. It is not clear whether oxygen has had discrete steady state levels at different times in Earth's history, or whether oxygen evolution is more progressive, with trigger points that lead to discrete changes in markers such as mass independent sulfur isotopes. Whatever this history may have been, ocean ridges play an important and poorly recognized part in the overall mass balance of oxidants and reductants that contribute to electron mass balance and the oxygen budget. One example is the current steady state O2 in the atmosphere. The carbon isotope data suggest that the fraction of carbon has increased in the Phanerozoic, and CO2 outgassing followed by organic matter burial should continually supply more O2 to the surface reservoirs. Why is O2 not then increasing? A traditional answer to this question would relate to variations in the fraction of burial of organic matter, but this fraction appears to have been relatively high throughout the Phanerozoic. Furthermore, subduction of carbon in the 1/5 organic/carbonate proportions would contribute further to an increasingly oxidized surface. What is needed is a flux of oxidized material out of the system. One solution would be a modern oxidized flux to the mantle. The current outgassing flux of CO2 is ~3.4*1012 moles per year. If 20% of that becomes stored organic carbon, that is a flux of .68*1012 moles per year of reduced carbon. The current flux of oxidized iron in subducting ocean crust is ~2*1012 moles per year of O2 equivalents, based on the Fe3+/Fe2+ ratios in old ocean crust compared to fresh basalts at the ridge axis. This flux more than accounts for the incremental oxidizing power produced by modern life. It also suggests a possible feedback through oxygenation of the ocean. A reduced deep ocean would inhibit oxidation of ocean crust, in which case there would be no subduction flux of oxidized

  10. Hot subduction: Magmatism along the Hunter Ridge, SW Pacific

    International Nuclear Information System (INIS)

    Crawford, A.J.; Verbeeten, A.; Danyushevsky, L.V.; Sigurdsson, I.A.; Maillet, P.; Monzier, M.

    1997-01-01

    The Hunter 'fracture zone' is generally regarded as a transform plate boundary linking the oppositely dipping Tongan and Vanuatu subduction systems. Dredging along the Hunter Ridge and sampling of its northernmost extent, exposed as the island of Kadavu in Fiji, has yielded a diversity of magmatic suites, including arc tholeiites and high-Ca boninites, high-Mg lavas with some affinities to boninites and some affinities to adakites, and true adakitic lavas associated with remarkable low-Fe, high-Na basalts with 8-16 ppm Nb (herein high-Nb basalts). Lavas which show clear evidence of slab melt involvement in their petrogenesis occur at either end of the Hunter Ridge, whereas the arc tholeiites and high-Ca boninites appear to be restricted to the south central part of the ridge. Mineralogical and whole rock geochemical data for each of these suites are summarized, and a tectono-magmatic model for their genesis and distribution is suggested. Trace element features and radiogenic isotope data for the Hunter Ridge lavas indicate compositions analogue to Pacific MORB-like mantle

  11. The extreme melt across the Greenland ice sheet in 2012

    Science.gov (United States)

    Nghiem, S. V.; Hall, D. K.; Mote, T. L.; Tedesco, M.; Albert, M. R.; Keegan, K.; Shuman, C. A.; DiGirolamo, N. E.; Neumann, G.

    2012-10-01

    The discovery of the 2012 extreme melt event across almost the entire surface of the Greenland ice sheet is presented. Data from three different satellite sensors - including the Oceansat-2 scatterometer, the Moderate-resolution Imaging Spectroradiometer, and the Special Sensor Microwave Imager/Sounder - are combined to obtain composite melt maps, representing the most complete melt conditions detectable across the ice sheet. Satellite observations reveal that melt occurred at or near the surface of the Greenland ice sheet across 98.6% of its entire extent on 12 July 2012, including the usually cold polar areas at high altitudes like Summit in the dry snow facies of the ice sheet. This melt event coincided with an anomalous ridge of warm air that became stagnant over Greenland. As seen in melt occurrences from multiple ice core records at Summit reported in the published literature, such a melt event is rare with the last significant one occurring in 1889 and the next previous one around seven centuries earlier in the Medieval Warm Period. Given its rarity, the 2012 extreme melt across Greenland provides an exceptional opportunity for new studies in broad interdisciplinary geophysical research.

  12. Complex Tectono-Magmatic Interaction along the George V Transform Fault, South-East Indian Ridge, 140°E, and Implications for Mantle Dynamics

    Science.gov (United States)

    Briais, A.; Ruellan, E.; Ceuleneer, G.; Maia, M.

    2017-12-01

    The 300 km-offset George V Transform Fault (TF) is the westernmost of the major, right-stepping transform faults that offset the South-East Indian Ridge between 140°E and 155°E. All these TFs have multiple shear zones with intra-transform ridge segments (ITRS), mostly unmapped yet. We present the results of the analysis of geophysical and petrological data collected during the STORM cruise (South Tasmania Ocean Ridge and Mantle). The data cover the western shear zone and part of two ITRSs. They reveal a complex interaction between tectonic processes at the plate boundary and near-axis volcanic activity along and across the transform fault. The western TF shear zone consists of two segments offset by a 50 km-long, 15 km-wide, up to 2000 m-high serpentinite massif. We infer that the massif is a push-up resulting from transpression along the transform, due to the lengthening of the western ITRS, with a mechanism similar to the processes currently uplifting the mylonitic massif along the St. Paul TF in the Equatorial Atlantic (1). The western ITRS is relatively shallow and magmatically robust, which is unexpected in a TF system. The bathymetric and backscatter maps also reveal a series of recent off-axis oblique volcanic ridges. Rocks dredged on one of these ridges consist of picrites (i.e. basalts rich in olivine phenocrysts). These observations suggest that the TF there is not magma starved like many mid-ocean ridge transforms, but is the locus of significant primitive melt supply. Such an unexpected production of high-Mg melt might be related to the presence of a mantle thermal anomaly beneath the easternmost SEIR, and/or to a western flow of mantle across the TF. *STORM cruise scientific party: A. Briais, F. Barrere, C. Boulart, D. Brunelli, G. Ceuleneer, N. Ferreira, B. Hanan, C. Hémond, S. Macleod, M. Maia, A. Maillard, S. Merkuryev, S.H. Park, S. Révillon, E. Ruellan, A. Schohn, S. Watson, and Y.S. Yang. (1) Maia et al. 2016 Nature Geo. doi:10.1038/ngeo2759

  13. Model of interfacial melting

    DEFF Research Database (Denmark)

    Mouritsen, Ole G.; Zuckermann, Martin J.

    1987-01-01

    A two-dimensional model is proposed to describe systems with phase transitions which take place in terms of crystalline as well as internal degrees of freedom. Computer simulation of the model shows that the interplay between the two sets of degrees of freedom permits observation of grain-boundar......-boundary formation and interfacial melting, a nonequilibrium process by which the system melts at the boundaries of a polycrystalline domain structure. Lipid membranes are candidates for systems with pronounced interfacial melting behavior....

  14. Continuous production of controlled release dosage forms based on hot-melt extruded gum arabic: Formulation development, in vitro characterization and evaluation of potential application fields.

    Science.gov (United States)

    Kipping, Thomas; Rein, Hubert

    2016-01-30

    Controlled release matrices based on gum arabic are prepared by applying a continuous hot-melt extrusion technology: the pre-mixture consisting of gum arabic and the incorporated API is plasticized by a co-rotating twin-screw extruder, an intermediate strand is formed by a round nozzle. Single dosed matrices are prepared by cutting the semi elastic strand with a rotary fly cutter. Paracetamol and phenazone are used as model drug substances. High drug loadings up to 70% can be realized. Matrices are characterized concerning their crystalline structure, in vitro dissolution, disintegration time and various physical parameters including glass transition temperature (Tg). Release characteristic behavior is mainly influenced by erosion of the matrices. At higher drug loadings also diffusion based transport gain importance. The solubility of the API shows an influence on the erosion rate of the matrix and should therefore be considered during formulation development. Tg is mainly influenced by the solubility of the API in the surrounding matrix. High soluble phenazone shows a decrease, whereas paracetamol addition has nearly no influence on the Tg of the polymeric system. Activation energy (EA) of the glass transition is determined via dynamic mechanical analysis. The addition of APIs leads to a reduction of EA indicating an increased molecular movement at Tg region compared to placebo extrudates. X-ray diffraction is used to determine the crystalline state of the extruded matrices and interaction between matrix and incorporated APIs. The production of thin layer matrices is an interesting option to provide a fast drug delivery to the oral cavity. High mechanical strength combined with fast disintegration times can be a great advantage for the development of oro-dispersible tablets. A great benefit of the evaluated processing technology is the simple adaption of the final dose by varying either the cutting length or the diameter of the nozzle resulting in a cost

  15. Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Melting Efficiency Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Principal Investigator Kent Peaslee; Co-PI’s: Von Richards, Jeffrey Smith

    2012-07-31

    Steel foundries melt recycled scrap in electric furnaces and typically consume 35-100% excess energy from the theoretical energy requirement required to pour metal castings. This excess melting energy is multiplied by yield losses during casting and finishing operations resulting in the embodied energy in a cast product typically being three to six times the theoretical energy requirement. The purpose of this research project was to study steel foundry melting operations to understand energy use and requirements for casting operations, define variations in energy consumption, determine technologies and practices that are successful in reducing melting energy and develop new melting techniques and tools to improve the energy efficiency of melting in steel foundry operations.

  16. Gondwana subduction-modified mantle domain prevents magmatic seafloor generation in the Central Indian Ridge

    Science.gov (United States)

    Morishita, T.; Nakamura, K.; Senda, R.; Suzuki, K.; Kumagai, H.; Sato, H.; Sato, T.; Shibuya, T.; Minoguchi, K.; Okino, K.

    2013-12-01

    The creation of oceanic crust at mid-ocean ridges is essential to understanding the genesis of oceanic plate and the evolution of the Earth. Detailed bathymetric measurements coupled with dense sample recovery at mid-ocean ridge revealed a wide range of variations in the ridge and seafloor morphologies, which cannot be simply explained by a spreading rate, but also by ridge geometry, mantle compositions and thermal structure (Dick et al., 2003 Nature; Cannat et al. 2006 Geology). It is now widely accepted that very limited magmatic activity with tectonic stretching generates oceanic core complex and/or smooth seafloor surface in the slow to ultraslow-spreading ridges, where serpentinized peridotite and gabbros are expected to be exposed associated with detachment faults (Cann et al., 1997 Nature; Cannat et al., 2006), although magmatism might be an essential role for the formation of oceanic core complexes (Buck et al., 2005 Nature; Tucholke et al 2008 JGR). A rising question is why magmatic activity is sometimes prevented during the oceanic plate formation. Ancient melting domain, that are too refractory to melt even in adiabatically upwelling to the shallow upper mantle, might cause the amagmatic spreading ridges (Harvey et al., 2006 EPSL, Liu et al.,2008 Nature). Its origin and effect on seafloor generations are, however, not well understood yet. We report an oceanic hill as an example of an ancient subduction-modified mantle domain, probably formed at continental margin of the Gondwanaland~Pangea supercontinent, existing beneath the Central Indian Ridge. This domain is the most likely to have prevented magmatic seafloor generation, resulting in creation of very deep oceanic valley and serpentine diaper (now the studied oceanic hill) at the present Central Indian ridge.

  17. The newly-discovered Late Cretaceous igneous rocks in the Nuocang district: Products of ancient crust melting trigged by Neo-Tethyan slab rollback in the western Gangdese

    Science.gov (United States)

    Jiang, Jun-Sheng; Zheng, You-Ye; Gao, Shun-Bao; Zhang, Yong-Chao; Huang, Jian; Liu, Jun; Wu, Song; Xu, Jing; Huang, Liang-Liang

    2018-05-01

    The newly discovered polymetallic Nuocang Pb-Zn skarn deposit is located in the southern Lhasa subterrane, western Gangdese, Tibet. The orebodies occur primarily at the contact zone between the Angjie Formation and the Linzizong volcanic rocks of Dianzhong Formation (LDF) that are dominated by basaltic andesitic tuff and rhyolite. Zircon U-Pb dating for two granite porphyries yield ages of 72.4 ± 0.2 Ma and 73.4 ± 0.9 Ma, which are different from the ages ( 69-60 Ma) of the LDF in the eastern Gangdese. The basaltic andesite tuff at Nuocang exhibits enrichment of MgO, TiO2, LILE, and LREE, with a relative depletion of SiO2, K2O, HFSE, and HREE, low Sr/Y ratios (32.9-38.0), and weak negative Eu anomalies (mean 0.86). They have 87Sr/86Sr(i) from 0.70695 to 0.70807 and εNd(t) values between -4.3 and -5.9. These features are similar to the Linzizong volcanic rocks of Dianzhong Formation in the Linzhou basin, indicating that they were associated with partial melting of mantle wedge mixing with 25-35% ancient Lhasa terrane basement. The rhyolite and granite porphyry show high SiO2 and K2O, and low Sr/Y ratio (1.2-9.9), enrichment of LILE and LREE and strong depletion of the HFSEs. They have pronounced negative Eu anomalies (mean 0.46), and εHf (t) values of the granite porphyry zircons range from -22.0 to -6.0. All these features suggest that they are the product of anatexis of ancient crustal materials heated by mantle-derived magma, the latter derived from Neo-Tethyan slab dehydration mechanisms. Combined with the previous geochronological and geochemical data, we proposed that the Nuocang district of western Gangdese in the southern Lhasa subterrane contains an ancient block, and the igneous rocks here were triggered by the Neo-Tethyan slab rollback starting at 82 Ma. The western Gangdese contains more ancient continental crustal materials and Late Cretaceous-Eocene Linzizong volcanic rocks and coeval intrusions than in the eastern Gangdese. Thus the western

  18. High resolution bathymetric and sonar images of a ridge southeast of Terceira Island (Azores plateau)

    Science.gov (United States)

    Lourenço, N.; Miranda, J. M.; Luis, J.; Silva, I.; Goslin, J.; Ligi, M.

    2003-04-01

    acoustic facies interpreted as pelagic and volcanic sediment. The numerous untectonized volcanic cones present to NE, in the northern flank of the North Hirondelle basin, align-up with the three volcanic systems of the Terceira Island (progressively less eroded towards west) and the Serreta ridge, thus suggesting propagation of a melt/thermal anomaly westwards through time. This volcanic area contrasts strongly with the highly fractured pattern observed in the ridge.

  19. Rapakivi texture formation via disequilibrium melting in a contact partial melt zone, Antarctica

    Science.gov (United States)

    Currier, R. M.

    2017-12-01

    In the McMurdo Dry Valleys of Antarctica, a Jurassic aged dolerite sill induced partial melting of granite in the shallow crust. The melt zone can be traced in full, from high degrees of melting (>60%) along the dolerite contact, to no apparent signs of melting, 10s of meters above the contact. Within this melt zone, the well-known rapakivi texture is found, arrested in various stages of development. High above the contact, and at low degrees of melting, K-feldspar crystals are slightly rounded and unmantled. In the lower half of the melt zone, mantles of cellular textured plagioclase appear on K-feldspar, and thicken towards the contact heat source. At the highest degrees of melting, cellular-textured plagioclase completely replaces restitic K-feldspar. Because of the complete exposure and intact context, the leading models of rapakivi texture formation can be tested against this system. The previously proposed mechanisms of subisothermal decompression, magma-mixing, and hydrothermal exsolution all fail to adequately describe rapakivi generation in this melt zone. Preferred here is a closed system model that invokes the production of a heterogeneous, disequilibrium melt through rapid heating, followed by calcium and sodium rich melt reacting in a peritectic fashion with restitic K-feldspar crystals. This peritectic reaction results in the production of plagioclase of andesine-oligoclase composition—which is consistent with not just mantles in the melt zone, but globally as well. The thickness of the mantle is diffusion limited, and thus a measure of the diffusive length scale of sodium and calcium over the time scale of melting. Thermal modeling provides a time scale of melting that is consistent with the thickness of observed mantles. Lastly, the distribution of mantled feldspars is highly ordered in this melt zone, but if it were mobilized and homogenized—mixing together cellular plagioclase, mantled feldspars, and unmantled feldspars—the result would be

  20. Cloud screening and melt water detection over melting sea ice using AATSR/SLSTR

    Science.gov (United States)

    Istomina, Larysa; Heygster, Georg

    2014-05-01

    of the product. Cloud detection over melting sea ice is a non-trivial problem as well. The sensitivity of AATSR 3.7 micron band to atmospheric reflectance is used to screen out clouds over melting sea ice.

  1. The Debate on the Prospective Interaction between SWIR 46°-52°E and Crozet hotspot: Constrain from the Geochemical Characteristics and Helium isotopes of MORBs from Southwest Indian Ridge

    Science.gov (United States)

    Yu, X.; Dick, H. J. B.; Chu, F.; Li, X.; Tang, L.

    2017-12-01

    The Southwest Indian Ridge with obvious mantle heterogeneity is often attributed to the influence of nearby hotspots. The Dragon Flag Supersegment between 46°E and 52°E on Marion Rise has thicker crust, shallower axial depth, and lower mantle Bouguer anomaly, which indicates ridge-hotspot interaction. However, the great distance between Crozet hotspot and the supersegment (about 1,000km) and the controversial geochemical data are both against the prospective ridge-hotspot interaction. Here we compiled major element, trace element, Sr-Nd-Pb and He isotopic data of new samples from the supersegment. The mantle source, partial melting process as well as the crystallization history of these basalts are further constrained based on the synthetic analysis of the dataset. Most basalts from the supersegment require 0 to 30% olivine and plagioclase fractionation to account for their present composition, whereas the crystallization of clinopyroxene appears to be rather limited. The parental magmas of the supersegment are distinctive from east to west. Most samples from the Eastern Group can be modeled as the product of 10% partial melting of a DMM-like source, while some extremely depleted samples from the central valley may require two stages of partial melting, i.e. ancient melting of DMM-like source, followed by recent remelting of the residues. The Western Group may be resulted from lower degree of partial melting (5-10%), or a previously less depleted mantle source. The Eastern Group is favor of the involvement of Crozet hotspot in terms of Pb isotope and helium isotope signatures, but the trace element and Sr-Nd isotopes are not supportive for this interaction. The especially high 206Pb/204Pb for some of the samples from the Eastern Group, similar to the Crozet hotspot, requires the sporadical entrainment of blobs of relatively enriched source material, like the Crozet component. The Crozet hotspot is distinctive in its Sr-Nd-Pb-He isotopes among different islands

  2. Magma plumbing system and seismicity of an active mid-ocean ridge volcano.

    Science.gov (United States)

    Schmid, Florian; Schlindwein, Vera; Koulakov, Ivan; Plötz, Aline; Scholz, John-Robert

    2017-02-20

    At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges.

  3. Molten (Mg0.88Fe0.12)2SiO4 at lower mantle conditions - Melting products and structure of quenched glasses

    Science.gov (United States)

    Williams, Quentin

    1990-01-01

    Infrared spectra of quenched magnesium silicate glasses synthesized by fusing olivine at pressures in excess of 50 GPa and temperatures greater than 2500 K demonstrate that silicon is dominantly present in four-fold coordination with respect to oxygen within these quenched glasses. This low coordination is attributed, by analogy with the structural behavior of glasses compressed at 300 K, to the instability of higher coordinations in glasses of these compositions on decompression. Spectra of glasses formed in a hydrous environment document that water is extensively soluble in melts at these high pressures and temperatures. Also, these results are consistent with the melting of (Mg0.88Fe0.12)2SiO4 compositions to liquids near pyroxene in stoichiometry under these conditions, with iron-rich magnesiowuestite being the liquidus phase.

  4. The mineral phase evolution behaviour in the production of glass-ceramics from municipal solid waste incineration fly ash by melting technology.

    Science.gov (United States)

    Luan, Jingde; Chai, Meiyun; Li, Rundong; Yao, Pengfei; Khan, Agha Saood

    2016-01-01

    High energy consumption was the major obstacle to the widespread application of melting technology in the treatment of municipal solid waste incineration fly ash. Aiming to lower the ash-melting temperature (AMT) for energy-saving, differential scanning calorimetry, X-ray diffraction and the scanning electron microscope were used to investigate the relations between AMT and the mineral evolution. The results indicated that the change of AMT was determined by the types and the contents of mineral crystals. The transition from refractory minerals to fluxing minerals was the key. The transition of the main crystalline phase from pseudowollastonite (Ca3(Si3O9)) to wollastonite (CaSiO3) played a significant role in AMT reduction. A quantum chemistry calculation was carried out to investigate the effect of crystal reaction activity on AMT. In the chemical reaction, the highest occupied molecular orbital and the lowest unoccupied molecular orbital played a more important role than any other orbits. Cations (Ca(2+), Mg(2+), Na(+), K(+)) were apt to enter into the crystal lattice of wollastonite and gehlenite mainly through Si (3), O (1), Si (6), O (10) and Al (2), O (10), and broke the covalent bonds of Si (3)-O (7), Al (1)-O (9) and Al (1)-O (15), respectively. This deconstruction behaviour provided convenient conditions for restructuring and promoted the formation of fluxing minerals. In melts, the excess SiO2 monomers which existed in the form of cristobalite and quartz caused AMT increase.

  5. ENVIRONMENTAL BASELINE SURVEY REPORT FOR WEST BLACK OAK RIDGE, EAST BLACK OAK RIDGE, MCKINNEY RIDGE, WEST PINE RIDGE, AND PARCEL 21D IN THE VICINITY OF THE EAST TENNESSEE TECHNOLOGY PARK, OAK RIDGE, TENNESSEE

    Energy Technology Data Exchange (ETDEWEB)

    David A. King

    2012-11-29

    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy’s (DOE’s) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. The goal is to obtain all media no-further-investigation (NFI) determinations for the subject parcels considering existing soils. To augment the existing soils-only NFI determinations, samples of groundwater, surface water, soil, and sediment were collected to support all media NFI decisions. The only updates presented here are those that were made after the original issuance of the NFI documents. In the subject parcel where the soils NFI determination was not completed for approval (Parcel 21d), the full process has been performed to address the soils as well. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only NFI

  6. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Oak Ridge Gaseous Diffusion Plant Site

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) technology, with the near-term goal to provide the necessary information to make a deployment decision by November 1992. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. A programmatic document for use in screening DOE sites to locate the U-AVLIS production plant was developed and implemented in two parts (Wolsko et al. 1991). The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were then subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the ORGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use, socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3. Following the site description and additional data requirements, Sec. 4 provides a short, qualitative assessment of potential environmental issues. 37 refs., 20 figs., 18 tabs.

  7. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Oak Ridge Gaseous Diffusion Plant Site

    International Nuclear Information System (INIS)

    1991-09-01

    In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) technology, with the near-term goal to provide the necessary information to make a deployment decision by November 1992. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. A programmatic document for use in screening DOE sites to locate the U-AVLIS production plant was developed and implemented in two parts (Wolsko et al. 1991). The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were then subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the ORGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use, socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3. Following the site description and additional data requirements, Sec. 4 provides a short, qualitative assessment of potential environmental issues. 37 refs., 20 figs., 18 tabs

  8. A correlated-cluster model and the ridge phenomenon in hadron–hadron collisions

    Energy Technology Data Exchange (ETDEWEB)

    Sanchis-Lozano, Miguel-Angel, E-mail: Miguel.Angel.Sanchis@ific.uv.es [Instituto de Física Corpuscular (IFIC) and Departamento de Física Teórica, Centro Mixto Universitat de València-CSIC, Dr. Moliner 50, E-46100 Burjassot, Valencia (Spain); Sarkisyan-Grinbaum, Edward, E-mail: sedward@cern.ch [Experimental Physics Department, CERN, 1211 Geneva 23 (Switzerland); Department of Physics, The University of Texas at Arlington, Arlington, TX 76019 (United States)

    2017-03-10

    A study of the near-side ridge phenomenon in hadron–hadron collisions based on a cluster picture of multiparticle production is presented. The near-side ridge effect is shown to have a natural explanation in this context provided that clusters are produced in a correlated manner in the collision transverse plane.

  9. A correlated-cluster model and the ridge phenomenon in hadron-hadron collisions

    CERN Document Server

    Sanchis-Lozano, Miguel-Angel

    2017-03-10

    A study of the near-side ridge phenomenon in hadron-hadron collisions based on a cluster picture of multiparticle production is presented. The near-side ridge effect is shown to have a natural explanation in this context provided that clusters are produced in a correlated manner in the collision transverse plane.

  10. Melting point of yttria

    International Nuclear Information System (INIS)

    Skaggs, S.R.

    1977-06-01

    Fourteen samples of 99.999 percent Y 2 O 3 were melted near the focus of a 250-W CO 2 laser. The average value of the observed melting point along the solid-liquid interface was 2462 +- 19 0 C. Several of these same samples were then melted in ultrahigh-purity oxygen, nitrogen, helium, or argon and in water vapor. No change in the observed temperature was detected, with the exception of a 20 0 C increase in temperature from air to helium gas. Post test examination of the sample characteristics, clarity, sphericity, and density is presented, along with composition. It is suggested that yttria is superior to alumina as a secondary melting-point standard

  11. Oak Ridge Leadership Computing Facility (OLCF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Oak Ridge Leadership Computing Facility (OLCF) was established at Oak Ridge National Laboratory in 2004 with the mission of standing up a supercomputer 100 times...

  12. Oak Ridge Geochemical Reconnaissance Program

    International Nuclear Information System (INIS)

    Arendt, J.W.

    1977-03-01

    The Oak Ridge reconnaissance program is responsible for the geochemical survey in a 12-state area covering Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Minnesota, Wisconsin, Michigan, Iowa, Indiana, and Illinois as part of the National Uranium Resource Evaluation Program. The program concept is outlined and the planning and organization of the program is discussed

  13. Force induced DNA melting

    International Nuclear Information System (INIS)

    Santosh, Mogurampelly; Maiti, Prabal K

    2009-01-01

    When pulled along the axis, double-strand DNA undergoes a large conformational change and elongates by roughly twice its initial contour length at a pulling force of about 70 pN. The transition to this highly overstretched form of DNA is very cooperative. Applying a force perpendicular to the DNA axis (unzipping), double-strand DNA can also be separated into two single-stranded DNA, this being a fundamental process in DNA replication. We study the DNA overstretching and unzipping transition using fully atomistic molecular dynamics (MD) simulations and argue that the conformational changes of double-strand DNA associated with either of the above mentioned processes can be viewed as force induced DNA melting. As the force at one end of the DNA is increased the DNA starts melting abruptly/smoothly above a critical force depending on the pulling direction. The critical force f m , at which DNA melts completely decreases as the temperature of the system is increased. The melting force in the case of unzipping is smaller compared to the melting force when the DNA is pulled along the helical axis. In the case of melting through unzipping, the double-strand separation has jumps which correspond to the different energy minima arising due to sequence of different base pairs. The fraction of Watson-Crick base pair hydrogen bond breaking as a function of force does not show smooth and continuous behavior and consists of plateaus followed by sharp jumps.

  14. On-line redox sensors in industrial glass melting tanks

    NARCIS (Netherlands)

    Laimböck, P.R.; Beerkens, R.G.C.; Schaaf, van der J.; Kieffer, J.

    2002-01-01

    The oxidation state or partial oxygen pressure (pO2) of the glass melt influences many glass melt and glass product properties such as fining and foaming behavior, radiant heat transfer, forming characteristics via (a color-dependent) cooling rate, and the glass color of the final product. For these

  15. Single scan vector prediction in selective laser melting

    NARCIS (Netherlands)

    Wits, Wessel Willems; Bruins, R.; Terpstra, L.; Huls, R.A.; Geijselaers, Hubertus J.M.

    2015-01-01

    In selective laser melting (SLM) products are built by melting layers of metal powder successively. Optimal process parameters are usually obtained by scanning single vectors and subsequently determining which settings lead to a good compromise between product density and build speed. This paper

  16. InRidge program: Preliminary results from the first cruise

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Murthy, K.S.R.; Iyer, S.D.; Rao, M.M.M.; Banerjee, R.; Subrahmanyam, A.S.; Shirodkar, P.V.; Ghose, I.

    The first cruise under India's own Ridge research initiative, InRidge collected new data on bathymetry, free-air gravity and magnetic anomalies across the ridge axis between the Vema and Zhivago transform faults in the Central Indian Ridge...

  17. The beach ridges of India: A review

    Digital Repository Service at National Institute of Oceanography (India)

    Kunte, P.D.; Wagle, B.G.

    , and is presented in a consolidated form. Beach ridges of the east and west coast of India are grouped in thirteen-beach ridge complexes based on their association. Review indicates that the beach ridges of India are not older than the Holocene age...

  18. BWR core melt progression phenomena: Experimental analyses

    International Nuclear Information System (INIS)

    Ott, L.J.

    1992-01-01

    In the BWR Core Melt in Progression Phenomena Program, experimental results concerning severe fuel damage and core melt progression in BWR core geometry are used to evaluate existing models of the governing phenomena. These include control blade eutectic liquefaction and the subsequent relocation and attack on the channel box structure; oxidation heating and hydrogen generation; Zircaloy melting and relocation; and the continuing oxidation of zirconium with metallic blockage formation. Integral data have been obtained from the BWR DF-4 experiment in the ACRR and from BWR tests in the German CORA exreactor fuel-damage test facility. Additional integral data will be obtained from new CORA BWR test, the full-length FLHT-6 BWR test in the NRU test reactor, and the new program of exreactor experiments at Sandia National Laboratories (SNL) on metallic melt relocation and blockage formation. an essential part of this activity is interpretation and use of the results of the BWR tests. The Oak Ridge National Laboratory (ORNL) has developed experiment-specific models for analysis of the BWR experiments; to date, these models have permitted far more precise analyses of the conditions in these experiments than has previously been available. These analyses have provided a basis for more accurate interpretation of the phenomena that the experiments are intended to investigate. The results of posttest analyses of BWR experiments are discussed and significant findings from these analyses are explained. The ORNL control blade/canister models with materials interaction, relocation and blockage models are currently being implemented in SCDAP/RELAP5 as an optional structural component

  19. The Oak Ridge Reservation Annual Site Environmental Report, 2007

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, Joan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Thompson, Sharon [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Page, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2008-09-30

    The Oak Ridge Reservation (ORR) consists of three major government-owned, contractor-operated facilities: the Y-12 National Security Complex, Oak Ridge National Laboratory, and East Tennessee Technology Park. The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced materials for the first atomic bombs. The reservation’s role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the United States. Both the work carried out for the war effort and subsequent research, development, and production activities have involved, and continue to involve, the use of radiological and hazardous materials. The Oak Ridge Reservation Annual Site Environmental Report and supporting data are available at Http://www.ornl.gov/sci/env_rpt or from the project director.

  20. Melting temperature of graphite

    International Nuclear Information System (INIS)

    Korobenko, V.N.; Savvatimskiy, A.I.

    2001-01-01

    Full Text: Pulse of electrical current is used for fast heating (∼ 1 μs) of metal and graphite specimens placed in dielectric solid media. Specimen consists of two strips (90 μm in thick) placed together with small gap so they form a black body model. Quasy-monocrystal graphite specimens were used for uniform heating of graphite. Temperature measurements were fulfilled with fast pyrometer and with composite 2-strip black body model up to melting temperature. There were fulfilled experiments with zirconium and tungsten of the same black body construction. Additional temperature measurements of liquid zirconium and liquid tungsten are made. Specific heat capacity (c P ) of liquid zirconium and of liquid tungsten has a common feature in c P diminishing just after melting. It reveals c P diminishing after melting in both cases over the narrow temperature range up to usual values known from steady state measurements. Over the next wide temperature range heat capacity for W (up to 5000 K) and Zr (up to 4100 K) show different dependencies of heat capacity on temperature in liquid state. The experiments confirmed a high quality of 2-strip black body model used for graphite temperature measurements. Melting temperature plateau of tungsten (3690 K) was used for pyrometer calibration area for graphite temperature measurement. As a result, a preliminary value of graphite melting temperature of 4800 K was obtained. (author)

  1. Hydrothermal plume anomalies over the southwest Indian ridge: magmatic control

    Science.gov (United States)

    Yue, X.; Li, H.; Tao, C.; Ren, J.; Zhou, J.; Chen, J.; Chen, S.; Wang, Y.

    2017-12-01

    Here we firstly reported the extensive survey results of the hydrothermal activity along the ultra-slow spreading southwest Indian ridge (SWIR). The study area is located at segment 27, between the Indomed and Gallieni transform faults, SWIR. The seismic crustal thickness reaches 9.5km in this segment (Li et al., 2015), which is much thicker than normal crustal. The anomaly thickened crust could be affected by the Crozet hotspot or highly focused melt delivery from the mantle. The Duanqiao hydrothermal field was reported at the ridge valley of the segment by Tao et al (2009). The Deep-towed Hydrothermal Detection System (DHDS) was used to collect information related with hydrothermal activity, like temperature, turbidity, oxidation-reduction potential (ORP) and seabed types. There are 15 survey lines at the interval of 2 to 3 km which are occupied about 1300 km2 in segment 27. After processing the raw data, including wiping out random noise points, 5-points moving average processing and subtracting the ambient, we got anomalous Nephelometric Turbidity Units values (ΔNTU). And dE/dt was used to identify the ORP anomalous as the raw data is easily influenced by electrode potentials drifting (Baker et al., 2016). According to the results of water column turbidity and ORP distributions, we confirmed three hydrothermal anomaly fields named A1, A2 and A3. The three fields are all located in the western part of the segment. The A1 field lies on the ridge valley, west side of Duanqiao field. The A2 and A3 field lie on the northern and southern of the ridge valley, respectively. We propose that recent magmatic activity probably focus on the western part of segment 27.And the extensive distribution of hydrothermal plume in the segment is the result of the discrete magma intrusion. References Baker E T, et al. How many vent fields? New estimates of vent field populations on ocean ridges from precise mapping of hydrothermal discharge locations. EPSL, 2016, 449:186-196. Li J

  2. Sulfide geochronlogy along the Southwest Indian Ridge

    Science.gov (United States)

    Yang, W.; Tao, C.; Li, H.; Liang, J.; Liao, S.

    2017-12-01

    Dragon Flag and Duanqiao hydrothermal field is located between the Indomed and Gallieni fracture zones in the ultraslow-spreading Southwest Indian Ridge (SWIR). Ten subsamples from active and inactive vents of Dragon Flag hydrothermal field and twenty-eight subsamples from Duanqiao hydrothermal field were dated using the 230Th/238U method. Four main episodes of hydrothermal activity of Duanqiao were determined according to the restricted results: 68.9-84.3, 43.9-48.4, 25.3-34.8, and 0.7-17.3 kyrs. Hydrothermal activity of Duanqiao probably started about 84.3 (±0.5) kyrs ago and ceased about 0.737 (±0.023) kyrs ago. And sulfide samples from the nearby Dragon Flag filed at the same time and the results show that the ages of most sulfides from Dragon Flag field range from 1.496(±0.176) to 5.416 (±0.116) kyrs with the oldest age estimated at 15.997 (±0.155) kyrs Münch et al. (2001) reconstructed the evolution history of Mt. Jourdanne hydrothermal field. The age dating results indicate activity in two episodes, at 70-40 and 27-13 kyrs. The hydrothermal activity in Dragon Flag field is much more recent than that of Duanqiao or Mt. Jourdanne fields. The massive sulfides are younger than the sulfides from other hydrothermal fields such as Rainbow, Sonne and Ashadze-2. All these results suggest that hydrothermal activity of Dragon Flag field is much more recent than that of Duanqiao or Mt. Jourdanne fields. Mt. Jourdanne is situated on an axial volcanic ridge which has both volcanic and tectonic activity. This is necessary to develop the heat source and pathways for the fluid convection, which enables the hydrothermal circulation. Hydrothermal activity in Dragon Flag Field is located next to the detachment fault termination. The detachment fault system provides a pathway for hydrothermal convection. Such style of heat source can contribute to continuous hydrothermal activity for over 1000 years. Duanqiao field is located near the central volcano and there is a hot

  3. In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 2: Site characterization report of the Pit 1 area

    Energy Technology Data Exchange (ETDEWEB)

    Spalding, B.P.; Bogle, M.A.; Cline, S.R.; Naney, M.T.; Gu, B.

    1997-12-01

    A treatability study was initiated in October 1993, initially encompassing the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was to have supported a possible Interim Record of Decision (IROD) or removal action for closure of one or more of the seepage pits and trenches as early as FY 1997. The Remedial Investigation/Feasibility Study for Waste Area Grouping (WAG) 7, which contains these seven seepage pits and trenches, will probably not begin until after the year 2000. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability to overlap melt settings that are necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of {sup 137}Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. This report summarizes the site characterization information gathered through the end of September 1996 which supports the planning and assessment of ISV for Pit 1 (objective 4 above).

  4. In situ vitrification demonstration at Pit 1, Oak Ridge National Laboratory. Volume 2: Site characterization report of the Pit 1 area

    International Nuclear Information System (INIS)

    Spalding, B.P.; Bogle, M.A.; Cline, S.R.; Naney, M.T.; Gu, B.

    1997-12-01

    A treatability study was initiated in October 1993, initially encompassing the application of in situ vitrification (ISV) to at least two segments of Oak Ridge National Laboratory (ORNL) seepage Pit 1 by the end of fiscal year (FY) 1995. This treatability study was to have supported a possible Interim Record of Decision (IROD) or removal action for closure of one or more of the seepage pits and trenches as early as FY 1997. The Remedial Investigation/Feasibility Study for Waste Area Grouping (WAG) 7, which contains these seven seepage pits and trenches, will probably not begin until after the year 2000. This treatability study will establish the field-scale technical performance of ISV for (1) attaining the required depth, nominally 15 ft, to incorporate source contamination within and beneath the pits; (2) demonstrating field capability to overlap melt settings that are necessary to achieve fused, melted segments of the source contamination; (3) demonstrating off-gas handling technology for accommodating and minimizing the volatilization of 137 Cs; (4) demonstrating adequate site characterization techniques to predict ISV melting kinetics, processing temperatures, and product durability; and (5) promoting public acceptance of ISV technology by demonstrating its safety, implementability, site impacts, and air emissions and by coordinating the treatability study within the regulatory closure process. This report summarizes the site characterization information gathered through the end of September 1996 which supports the planning and assessment of ISV for Pit 1 (objective 4 above)

  5. Two stage melt-rock interaction in the lower oceanic crust of the Parece Vela basin (Philippine sea), evidence from the primitive troctolites from the Godzilla Megamullion

    Science.gov (United States)

    Sanfilippo, A.; Dick, H. J.; Ohara, Y.

    2011-12-01

    Godzilla Megamullion is a giant oceanic core complex exposed in an extinct slow- to intermediate-spreading segment of the Parece Vela Basin (Philippine sea) [1; 2]. It exposes lower crust and mantle rocks on the sea-floor, offering a unique opportunity to unravel the architecture and the composition of the lower oceanic lithosphere of an extinct back arc basin. Here we present data on primitive troctolites and associated olivine-gabbros from the breakaway area of the Godzilla Megamullion. On the basis of the olivine/plagioclase volume ratio, the troctolites are subdivided into Ol-troctolites (Ol/Pl >1) and Pl-troctolites (Ol/Plthe olivine and a melt crystallizing plagioclase and clinopyroxene. We interpret these rocks as reaction products of a dunite matrix with transient basaltic melts [e.g. 3; 4]. Pl-troctolites have euhedral plagioclase and poikilitic olivine and clinopyroxene. Irregular shapes and inverse zoning of the plagioclase chadacrysts within the olivine indicate disequilibrium between existing plagioclase and an olivine-clinopyroxene saturated melt. The occurrence of plagioclase chadacrysts within clinopyroxene ranging from irregular to euhedral in shape suggests crystallization of new lower-Na plagioclase with the clinopyroxene. Olivine oikocrysts in the Pl-troctolites have low-NiO olivine in equilibrium with a high-MgO melt. The Pl-troctolites, then, may be the product of reaction between a plagioclase cumulate and a basaltic melt produced by mixing the high-MgO melt residual to the formation of the Ol-troctolites with new magma. The effect of melt-rock reaction in the Pl- and Ol- troctolites explains the sharp decrease in plagioclase An with respect to Mg# in clinopyroxene and olivine. Furthermore, the melt is shifted towards lower Na, which is consistent with the low Na8 values of the associated MORB glasses (2.4-2.7 wt %). Our results, then, show that melt-rock interaction was a process active in the lower oceanic crust of the Parece Vela basin and

  6. Bose enhancement and the ridge

    Energy Technology Data Exchange (ETDEWEB)

    Altinoluk, Tolga [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Armesto, Néstor, E-mail: nestor.armesto@usc.es [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, 15706 Santiago de Compostela, Galicia (Spain); Beuf, Guillaume [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel); Kovner, Alex [Physics Department, University of Connecticut, 2152 Hillside Road, Storrs, CT 06269-3046 (United States); Lublinsky, Michael [Department of Physics, Ben-Gurion University of the Negev, Beer Sheva 84105 (Israel)

    2015-12-17

    We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

  7. Bose enhancement and the ridge

    Directory of Open Access Journals (Sweden)

    Tolga Altinoluk

    2015-12-01

    Full Text Available We point out that Bose enhancement in a hadronic wave function generically leads to correlations between produced particles. We show explicitly, by calculating the projectile density matrix in the Color Glass Condensate approach to high-energy hadronic collisions, that the Bose enhancement of gluons in the projectile leads to azimuthal collimation of long range rapidity correlations of the produced particles, the so-called ridge correlations.

  8. Oak Ridge National Laboratory Review

    Energy Technology Data Exchange (ETDEWEB)

    Krause, C.; Pearce, J.; Zucker, A. (eds.)

    1992-01-01

    This report presents brief descriptions of the following programs at Oak Ridge National Laboratory: The effects of pollution and climate change on forests; automation to improve the safety and efficiency of rearming battle tanks; new technologies for DNA sequencing; ORNL probes the human genome; ORNL as a supercomputer research center; paving the way to superconcrete made with polystyrene; a new look at supercritical water used in waste treatment; and small mammals as environmental monitors.

  9. Chemical provinces and dynamic melting of the NE Atlantic mantle

    Science.gov (United States)

    Tronnes, R. G.

    2009-12-01

    Low-degree melting of fertile parts of the NE Atlantic mantle yields primitive alkaline basalts in the Icelandic off-rift zones and at Jan Mayen. Olivine tholeiites in the Icelandic rift zones and oceanic spreading ridges are formed by protracted decompressional melting. The V-shaped ridges SW and NE of Iceland indicate that rising, hot material is supplied by a pulsating plume and deflected laterally for distances of about 1000 km from Iceland (Jones et al. GGG 2002; Breivik et al. JGR 2006). Plume material deflected along the rift zones and spreading ridges undergoes mixing with the ambient asthenosphere and extensive melting at shallow level, whereas material deflected in other directions may flow laterally at deeper levels and remain largely unmelted and fertile. A recent investigation of a suite of primitive off-rift basalts from Iceland and Jan Mayen (Debaille et al., 2009, GCA) demonstrated an important source contribution from subcontinental lithospheric mantle (SCLM). Available data on the primitive off-rift basalts and tholeiitic basalts from Iceland and the NE Atlantic ridges indicates the existence of three main composite mantle components, characterized by the following relative isotope ratios (H: high, I: intermediate and L: low ratio) for 87/86Sr, 143/144Nd, 206/204Pb, 187/188Os and 3/4He, respectively: 1. Iceland plume with depleted lower mantle mixed with recycled oceanic crust: I, I, H, H, H 2. Strongly depleted and later re-enriched SCLM: H, L, I, L, L 3. Depleted asthenosphere: L, H, L, I, L The two first composite components contain enriched and depleted subcomponents with distinct isotope signatures. The isotope ratio variations between the fertile components are larger than between the refractory components. The 3/4He ratio, however, is much higher in the depleted plume component than in the depleted SCLM and asthenospheric components. The old SCLM material could in principle be recycled and embedded in the lower mantle and supplied to the

  10. Olivine-hosted melt inclusions as an archive of redox heterogeneity in magmatic systems

    Science.gov (United States)

    Hartley, Margaret E.; Shorttle, Oliver; Maclennan, John; Moussallam, Yves; Edmonds, Marie

    2017-12-01

    The redox state of volcanic products determines their leverage on the oxidation of Earth's oceans and atmosphere, providing a long-term feedback on oxygen accumulation at the planet's surface. An archive of redox conditions in volcanic plumbing systems from a magma's mantle source, through crustal storage, to eruption, is carried in pockets of melt trapped within crystals. While melt inclusions have long been exploited for their capacity to retain information on a magma's history, their permeability to fast-diffusing elements such as hydrogen is now well documented and their retention of initial oxygen fugacities (fO2) could be similarly diffusion-limited. To test this, we have measured Fe3+/ΣFe by micro-XANES spectroscopy in a suite of 65 olivine-hosted melt inclusions and 9 matrix glasses from the AD 1783 Laki eruption, Iceland. This eruption experienced pre-eruptive mixing of chemically diverse magmas, syn-eruptive degassing at the vent, and post-eruptive degassing during lava flow up to 60 km over land, providing an ideal test of whether changes in the fO2 of a magma may be communicated through to its cargo of crystal-hosted melt inclusions. Melt inclusions from rapidly quenched tephra samples have Fe3+/ΣFe of 0.206 ± 0.008 (ΔQFM of +0.7 ± 0.1), with no correlation between their fO2 and degree of trace element enrichment or differentiation. These inclusions preserve the redox conditions of the mixed pre-eruptive Laki magma. When corrected for fractional crystallisation to 10 wt.% MgO, these inclusions record a parental magma [Fe3+/ΣFe](10) of 0.18 (ΔQFM of +0.4), significantly more oxidised than the Fe3+/ΣFe of 0.10 that is often assumed for Icelandic basalt magmas. Melt inclusions from quenched lava selvages are more reduced than those from the tephra, having Fe3+/ΣFe between 0.133 and 0.177 (ΔQFM from -0.4 to +0.4). These inclusions have approached equilibrium with their carrier lava, which has been reduced by sulfur degassing. The progressive re

  11. Melting of gold microclusters

    International Nuclear Information System (INIS)

    Garzon, I.L.; Jellinek, J.

    1991-01-01

    The transition from solid-like to liquid-like behavior in Au n , n=6, 7, 13, clusters is studied using molecular dynamics simulations. A Gupta-type potential with all-neighbour interactions is employed to incorporate n-body effects. The melting-like transition is described in terms of short-time averages of the kinetic energy per particle, root-mean-square bond length fluctuations and mean square displacements. A comparison between melting temperatures of Au n and Ni n clusters is presented. (orig.)

  12. Electron beam melting state-of-the-art 1984

    International Nuclear Information System (INIS)

    Bakish, R.

    1984-01-01

    In 1984 electron beam melting and refining appear poised for an important new growth phase. The driving force for this phase is improved production economics made possible by technological advances. There is also a new and exciting growth application for electron beam melting: its use for surface properties beneficiation. This article is based in part on the content of the Conference on Electron Beam Melting and Refining, The State-of-the-Art 1983, held in November 1983 in Reno, Nevada

  13. Data Sharing Report Characterization of Isotope Row Facilities Oak Ridge National Laboratory Oak Ridge TN

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Phyllis C. [Oak Ridge Inst. for Science and Education (ORISE), Oak Ridge, TN (United States)

    2013-12-12

    The U.S. Department of Energy (DOE) Oak Ridge Office of Environmental Management (EM-OR) requested that Oak Ridge Associated Universities (ORAU), working under the Oak Ridge Institute for Science and Education (ORISE) contract, provide technical and independent waste management planning support using funds provided by the American Recovery and Reinvestment Act (ARRA). Specifically, DOE EM-OR requested ORAU to plan and implement a survey approach, focused on characterizing the Isotope Row Facilities located at the Oak Ridge National Laboratory (ORNL) for future determination of an appropriate disposition pathway for building debris and systems, should the buildings be demolished. The characterization effort was designed to identify and quantify radiological and chemical contamination associated with building structures and process systems. The Isotope Row Facilities discussed in this report include Bldgs. 3030, 3031, 3032, 3033, 3033A, 3034, 3036, 3093, and 3118, and are located in the northeast quadrant of the main ORNL campus area, between Hillside and Central Avenues. Construction of the isotope production facilities was initiated in the late 1940s, with the exception of Bldgs. 3033A and 3118, which were enclosed in the early 1960s. The Isotope Row facilities were intended for the purpose of light industrial use for the processing, assemblage, and storage of radionuclides used for a variety of applications (ORNL 1952 and ORAU 2013). The Isotope Row Facilities provided laboratory and support services as part of the Isotopes Production and Distribution Program until 1989 when DOE mandated their shutdown (ORNL 1990). These facilities performed diverse research and developmental experiments in support of isotopes production. As a result of the many years of operations, various projects, and final cessation of operations, production was followed by inclusion into the surveillance and maintenance (S&M) project for eventual decontamination and decommissioning (D&D). The

  14. GLASS MELTING PHENOMENA, THEIR ORDERING AND MELTING SPACE UTILISATION

    Directory of Open Access Journals (Sweden)

    Němec L.

    2013-12-01

    Full Text Available Four aspects of effective glass melting have been defined – namely the fast kinetics of partial melting phenomena, a consideration of the melting phenomena ordering, high utilisation of the melting space, and effective utilisation of the supplied energy. The relations were defined for the specific melting performance and specific energy consumption of the glass melting process which involve the four mentioned aspects of the process and indicate the potentials of effective melting. The quantity “space utilisation” has been treated in more detail as an aspect not considered in practice till this time. The space utilisation was quantitatively defined and its values have been determined for the industrial melting facility by mathematical modelling. The definitions of the specific melting performance and specific energy consumption have been used for assessment of the potential impact of a controlled melt flow and high space utilisation on the melting process efficiency on the industrial scale. The results have shown that even the partial control of the melt flow, leading to the partial increase of the space utilisation, may considerably increase the melting performance, whereas a decrease of the specific energy consumption was determined to be between 10 - 15 %.

  15. Significance testing in ridge regression for genetic data

    Directory of Open Access Journals (Sweden)

    De Iorio Maria

    2011-09-01

    Full Text Available Abstract Background Technological developments have increased the feasibility of large scale genetic association studies. Densely typed genetic markers are obtained using SNP arrays, next-generation sequencing technologies and imputation. However, SNPs typed using these methods can be highly correlated due to linkage disequilibrium among them, and standard multiple regression techniques fail with these data sets due to their high dimensionality and correlation structure. There has been increasing interest in using penalised regression in the analysis of high dimensional data. Ridge regression is one such penalised regression technique which does not perform variable selection, instead estimating a regression coefficient for each predictor variable. It is therefore desirable to obtain an estimate of the significance of each ridge regression coefficient. Results We develop and evaluate a test of significance for ridge regression coefficients. Using simulation studies, we demonstrate that the performance of the test is comparable to that of a permutation test, with the advantage of a much-reduced computational cost. We introduce the p-value trace, a plot of the negative logarithm of the p-values of ridge regression coefficients with increasing shrinkage parameter, which enables the visualisation of the change in p-value of the regression coefficients with increasing penalisation. We apply the proposed method to a lung cancer case-control data set from EPIC, the European Prospective Investigation into Cancer and Nutrition. Conclusions The proposed test is a useful alternative to a permutation test for the estimation of the significance of ridge regression coefficients, at a much-reduced computational cost. The p-value trace is an informative graphical tool for evaluating the results of a test of significance of ridge regression coefficients as the shrinkage parameter increases, and the proposed test makes its production computationally feasible.

  16. Slab melting and magma formation beneath the southern Cascade arc

    Science.gov (United States)

    Walowski, Kristina J.; Wallace, Paul J.; Clynne, Michael A.; Rasmussen, D.J.; Weis, D.

    2016-01-01

    The processes that drive magma formation beneath the Cascade arc and other warm-slab subduction zones have been debated because young oceanic crust is predicted to largely dehydrate beneath the forearc during subduction. In addition, geochemical variability along strike in the Cascades has led to contrasting interpretations about the role of volatiles in magma generation. Here, we focus on the Lassen segment of the Cascade arc, where previous work has demonstrated across-arc geochemical variations related to subduction enrichment, and H-isotope data suggest that H2O in basaltic magmas is derived from the final breakdown of chlorite in the mantle portion of the slab. We use naturally glassy, olivine-hosted melt inclusions (MI) from the tephra deposits of eight primitive (MgO>7 wt%) basaltic cinder cones to quantify the pre-eruptive volatile contents of mantle-derived melts in this region. The melt inclusions have B concentrations and isotope ratios that are similar to mid-ocean ridge basalt (MORB), suggesting extensive dehydration of the downgoing plate prior to reaching sub-arc depths and little input of slab-derived B into the mantle wedge. However, correlations of volatile and trace element ratios (H2O/Ce, Cl/Nb, Sr/Nd) in the melt inclusions demonstrate that geochemical variability is the result of variable addition of a hydrous subduction component to the mantle wedge. Furthermore, correlations between subduction component tracers and radiogenic isotope ratios show that the subduction component has less radiogenic Sr and Pb than the Lassen sub-arc mantle, which can be explained by melting of subducted Gorda MORB beneath the arc. Agreement between pMELTS melting models and melt inclusion volatile, major, and trace element data suggests that hydrous slab melt addition to the mantle wedge can produce the range in primitive compositions erupted in the Lassen region. Our results provide further evidence that chlorite-derived fluids from the mantle portion of the

  17. A new method for the continuous production of single dosed controlled release matrix systems based on hot-melt extruded starch: analysis of relevant process parameters and implementation of an in-process control.

    Science.gov (United States)

    Kipping, Thomas; Rein, Hubert

    2013-05-01

    In the present study, we evaluated a novel processing technique for the continuous production of hot-melt extruded controlled release matrix systems. A cutting technique derived from plastics industry, where it is widely used for cutting of cables and wires was adapted into the production line. Extruded strands were shaped by a rotary fly cutter. Special focus is laid on the development of a process analytical technology by evaluating signals obtained from the servo control of the rotary fly cutter. The intention is to provide a better insight into the production process and to offer the ability to detect small variations in process-variables. A co-rotating twin-screw extruder ZSE 27 HP-PH from Leistritz (Nürnberg, Germany) was used to plasticize the starch; critical extrusion parameters were recorded. Still elastic strands were shaped by a rotary fly-cutter type Dynamat 20 from Metzner (Neu-Ulm, Germany). Properties of the final products were analyzed via digital image analysis to point out critical parameters influencing the quality. Important aspects were uniformity of diameter, height, roundness, weight, and variations in the cutting angle. Stability of the products was measured by friability tests and by determining the crushing strength of the final products. Drug loading studies up to 70% were performed to evaluate the capacity of the matrix and to prove the technological feasibility. Changes in viscosities during API addition were analyzed by a Haake Minilab capillary rheometer. X-ray studies were performed to investigate molecular structures of the matrices. External shapes of the products were highly affected by die-swelling of the melt. Reliable reproducibility concerning uniformity of mass could be achieved even for high production rates (>2500cuts/min). Both mechanical strength and die-swelling of the products could be linked to the ratio of amylose to amylopectin. Formulations containing up to 70% of API could still be processed. Viscosity

  18. Melt layer behavior of metal targets irradiatead by powerful plasma streams

    International Nuclear Information System (INIS)

    Bandura, A.N.; Byrka, O.V.; Chebotarev, V.V.; Garkusha, I.E.; Makhlaj, V.A.; Solyakov, D.G.; Tereshin, V.I.; Wuerz, H.

    2002-01-01

    In this paper melt layer erosion of metal targets under pulsed high-heat loads is studied. Experiments with steel, copper, aluminum and titanium samples were carried out in two plasma accelerator devices with different time durations of the heat load. The surfaces of the resolidified melt layers show a considerable roughness with microcraters and ridge like relief on the surface. For each material the mass loss was determined. Melt layer erosion by melt motion was clearly identified. However it is masked by boiling, bubble expansion and bubble collapse and by formation of a Kelvin-Helmholtz instability. The experimental results can be used for validation of numerical codes which model melt layer erosion of metallic armour materials in off-normal events, in tokamaks

  19. Melt layer behavior of metal targets irradiatead by powerful plasma streams

    Energy Technology Data Exchange (ETDEWEB)

    Bandura, A.N.; Byrka, O.V.; Chebotarev, V.V.; Garkusha, I.E. E-mail: garkusha@ipp.kharkov.ua; Makhlaj, V.A.; Solyakov, D.G.; Tereshin, V.I.; Wuerz, H

    2002-12-01

    In this paper melt layer erosion of metal targets under pulsed high-heat loads is studied. Experiments with steel, copper, aluminum and titanium samples were carried out in two plasma accelerator devices with different time durations of the heat load. The surfaces of the resolidified melt layers show a considerable roughness with microcraters and ridge like relief on the surface. For each material the mass loss was determined. Melt layer erosion by melt motion was clearly identified. However it is masked by boiling, bubble expansion and bubble collapse and by formation of a Kelvin-Helmholtz instability. The experimental results can be used for validation of numerical codes which model melt layer erosion of metallic armour materials in off-normal events, in tokamaks.

  20. Variational Ridging in Sea Ice Models

    Science.gov (United States)

    Roberts, A.; Hunke, E. C.; Lipscomb, W. H.; Maslowski, W.; Kamal, S.

    2017-12-01

    This work presents the results of a new development to make basin-scale sea ice models aware of the shape, porosity and extent of individual ridges within the pack. We have derived an analytic solution for the Euler-Lagrange equation of individual ridges that accounts for non-conservative forces, and therefore the compressive strength of individual ridges. Because a region of the pack is simply a collection of paths of individual ridges, we are able to solve the Euler-Lagrange equation for a large-scale sea ice field also, and therefore the compressive strength of a region of the pack that explicitly accounts for the macro-porosity of ridged debris. We make a number of assumptions that have simplified the problem, such as treating sea ice as a granular material in ridges, and assuming that bending moments associated with ridging are perturbations around an isostatic state. Regardless of these simplifications, the ridge model is remarkably predictive of macro-porosity and ridge shape, and, because our equations are analytic, they do not require costly computations to solve the Euler-Lagrange equation of ridges on the large scale. The new ridge model is therefore applicable to large-scale sea ice models. We present results from this theoretical development, as well as plans to apply it to the Regional Arctic System Model and a community sea ice code. Most importantly, the new ridging model is particularly useful for pinpointing gaps in our observational record of sea ice ridges, and points to the need for improved measurements of the evolution of porosity of deformed ice in the Arctic and Antarctic. Such knowledge is not only useful for improving models, but also for improving estimates of sea ice volume derived from altimetric measurements of sea ice freeboard.

  1. MELT-IIIB: an updated version of the melt code

    International Nuclear Information System (INIS)

    Tabb, K.K.; Lewis, C.H.; O'Dell, L.D.; Padilla, A. Jr.; Smith, D.E.; Wilburn, N.P.

    1979-04-01

    The MELT series is a reactor modeling code designed to investigate a wide variety of hypothetical accident conditions, particularly the transient overpower sequence. MELT-IIIB is the latest in the series

  2. Remedial investigation work plan for Chestnut Ridge Operable Unit 4 (Rogers Quarry/Lower McCoy Branch) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    The Oak Ridge Y-12 Plant includes - 800 acres near the northeast comer of the reservation and adjacent to the city of Oak Ridge (Fig. 1-1). The plant is a manufacturing and developmental engineering facility that produced components for various nuclear weapons systems and provides engineering support to other Energy Systems facilities. More than 200 contaminated sites have been identified at the Y-12 Plant that resulted from past waste management practices. Many of the sites have operable units (OUs) based on priority and on investigative and remediation requirements. This Remedial Investigation RI work plan specifically addresses Chestnut Ridge OU 4. Chestnut Ridge OU 4 consists of Rogers Quarry and Lower McCoy Branch (MCB). Rogers Quarry, which is also known as Old Rogers Quarry or Bethel Valley Quarry was used for quarrying from the late 1940s or early 1950s until about 1960. Since that time, the quarry has been used for disposal of coal ash and materials from Y-12 production operations, including classified materials. Disposal of coal ash ended in July 1993. An RI is being conducted at this site in response to CERCLA regulations. The overall objectives of the RI are to collect data necessary to evaluate the nature and extent of contaminants of concern, support an Ecological Risk Assessment and a Human Health Risk Assessment, support the evaluation of remedial alternatives, and ultimately develop a Record of Decision for the site. The purpose of this work plan is to outline RI activities necessary to define the nature and extent of suspected contaminants at Chestnut Ridge OU 4. Potential migration pathways also will be investigated. Data collected during the RI will be used to evaluate the risk posed to human health and the environment by OU 4.

  3. Processing of Oak Ridge B ampersand C pond sludge surrogate in the transportable vitrification system

    International Nuclear Information System (INIS)

    Zamecnik, J.R.; Young, S.R.; Peeler, D.K.; Smith, M.E.

    1997-01-01

    The Transportable Vitrification System (TVS) developed at the Savannah River Site is designed to process low-level and mixed radioactive wastes into a stable glass product. The TVS consists of a feed preparation and delivery system, a joule-heated melter, and an offgas treatment system. Surrogate Oak Ridge Reservation (ORR) B ampersand amp;C pond sludge was treated in a demonstration of the TVS system at Clemson University and at ORR. After initial tests with soda-lime-silica (SLS) feed, three melter volumes of glass were produced from the surrogate feed. A forthcoming report will describe glass characterization; and melter feeding, operation, and glass pouring. Melter operations described will include slurry characterization and feeding, factors affecting feed melt rates, glass pouring and pour rate constraints, and melter operating temperatures. Residence time modeling of the melter will also be discussed. Characterization of glass; including composition, predicted liquidity and viscosity, Toxic Characteristic Leaching Procedure (TCLP), and devitrification will be covered. Devitrification was a concern in glass container tests and was found to be mostly dependent on the cooling rate. Crucible tests indicated that melter shutdown with glass containing Fe and Li was also a devitrification concern, so the melter was flushed with SLS glass before cooldown

  4. Influence of gas-generation on melt/concrete interaction

    International Nuclear Information System (INIS)

    Powers, D.A.

    1979-01-01

    Gases formed during the interaction of a high-temperature melt with concrete are shown to stem from the thermal dehydration and decarboxylation of the concrete. The kinetics of these decomposition reactions are described. Gases within the melt cause an apparent swelling of the melt. The observed swelling is not easily correlated to the rate of gas evolution. Metallic melts cause CO 2 /CO and H 2 O liberated from the melt to be reduced to CO and hydrogen. When these gases escape from the melt they assist in aerosol formation. As the gases cool they react along a pathway whose oxygen fugacity is apparently buffered by the iron-Wuestite equilibrium. Methane is a product of the gas-phase reaction. (orig./HP) [de

  5. Analysis of crustal thickness and off-axis low-velocity zones at the Endeavour segment of the Juan de Fuca Ridge

    Science.gov (United States)

    Wells, A. E.; Hooft, E. E.; Toomey, D. R.; Wilcock, W. S.; Weekly, R. T.

    2010-12-01

    Construction of the oceanic crust is often thought to occur by delivery of melt from the mantle to the ridge axis that is both segment-centered and rise-centered. However, recent seismic studies at the fast-spreading East Pacific Rise show that mantle melt delivery can be skewed relative to the rise leading to off-axis delivery of melt. Furthermore foci of mantle melt delivery occur on a length-scale shorter than that of a ridge segment and the region of greater melt supply, as measured by crustal thickness, does not correspond to the segment center. We use seismic data from the intermediate-spreading Endeavour segment of the Juan de Fuca Ridge to investigate the spatial and temporal pattern of melt supply in this setting and whether off-axis delivery and transport of melt is a common occurrence. The Juan de Fuca Ridge has a transitional morphology characterized by fault-bounded ridges that parallel the spreading center. Previous models of the Endeavour segment inferred that the off-axis ridges are constructed during periods of enhanced magmatism and that these are separated by the remains of rift valleys generated during periods of reduced magmatism. This model may imply that crustal thickness should vary rapidly, with thicker crust beneath the off-axis ridges and thinner crust in between. Alternatively, on the basis of recent seismic reflection images of crustal magma bodies along the Juan de Fuca ridge this topography is thought to reflect magma-induced deformation resulting from feedbacks between the rheology of the crust above the magma sill and dike intrusion. In this case, short wavelength crustal thickness variations may not be present. The melting anomalies associated with various nearby seamount chains also influence processes along the Juan de Fuca Ridge. The seismic reflection work indicates that there is a ~40-km-wide plateau of greater crustal thickness (~0.5-1.0 km) at the center of the Endeavour segment that began forming about 0.7 Ma. The plateau

  6. Why Archaean TTG cannot be generated by MORB melting in subduction zones

    Science.gov (United States)

    Martin, Hervé; Moyen, Jean-François; Guitreau, Martin; Blichert-Toft, Janne; Le Pennec, Jean-Luc

    2014-06-01

    Until recently it was assumed that the Archaean continental crust (made of TTGs: tonalites, trondhjemites, and granodiorites) was generated through partial melting of MORB-like basalts in hot subduction environments, where the subducted oceanic crust melted at high pressure, leaving a garnet-bearing amphibolitic or eclogitic residue. However, recent geochemical models as well as basalt melting experiments have precluded MORB as a plausible source for TTGs. Rather, geochemical and experimental evidences indicate that formation of TTG required a LILE-enriched source, similar to oceanic plateau basalts. Moreover, subduction is a continuous process, while continental growth is episodic. Several “super-growth events” have been identified at ~ 4.2, ~ 3.8, ~ 3.2, ~ 2.7, ~ 1.8, ~ 1.1, and ~ 0.5 Ga, which is inconsistent with the regular pattern that would be expected from a subduction-driven process. In order to account for this periodicity, it has been proposed that, as subduction proceeds, descending residual slabs accumulate at the 660-km seismic discontinuity. When stored oceanic crust exceeds a certain mass threshold, it rapidly sinks into the mantle as a cold avalanche, which induces the ascent of mantle plumes that in turn produce large amounts of magmas resulting in oceanic plateaus. However, melting at the base of thick oceanic plateaus does not appear to be a realistic process that can account for TTG genesis. Modern oceanic plateaus contain only small volumes (≤ 5%) of felsic magmas generally formed by high degrees of fractional crystallization of basaltic magmas. The composition of these felsic magmas drastically differs from that of TTGs. In Iceland, the interaction between a mantle plume and the mid-Atlantic ridge gives rise to an anomalously (Archaean-like) high geothermal gradient resulting in thick basaltic crust able to melt at shallow depth. Even in this favorable context though, the characteristic Archaean TTG trace element signature is not being

  7. Melting of polydisperse hard disks

    NARCIS (Netherlands)

    Pronk, S.; Frenkel, D.

    2004-01-01

    The melting of a polydisperse hard-disk system is investigated by Monte Carlo simulations in the semigrand canonical ensemble. This is done in the context of possible continuous melting by a dislocation-unbinding mechanism, as an extension of the two-dimensional hard-disk melting problem. We find

  8. Thermodynamics of Oligonucleotide Duplex Melting

    Science.gov (United States)

    Schreiber-Gosche, Sherrie; Edwards, Robert A.

    2009-01-01

    Melting temperatures of oligonucleotides are useful for a number of molecular biology applications, such as the polymerase chain reaction (PCR). Although melting temperatures are often calculated with simplistic empirical equations, application of thermodynamics provides more accurate melting temperatures and an opportunity for students to apply…

  9. Analysis of elementary process steps in industrial glass melting tanks: some ideas on innovations in industrial glass melting

    NARCIS (Netherlands)

    Beerkens, R.G.C.

    2008-01-01

    Conventional industrial glass furnaces show broad glass melt residence time distributions in the melting tanks and average residence times may be up to more than two days for high quality glass products, such as float glass or TV glass, despite the minimum residence times of 8-10 hours (or even less

  10. Anisotropy of the upper mantle beneath the equatorial part of the Mid-Atlantic Ridge

    Science.gov (United States)

    Kendall, J. M.; Rychert, C.; Harmon, N.; Tharimena, S.; Agius, M. R.

    2017-12-01

    It has been long-known that the mantle beneath ocean spreading centres is anisotropic, holding the signature of the formation of new oceanic lithosphere and its coupling with the underlying convecting asthenosphere. Numerical studies have suggested that there should be significant differences between the anisotropy at slow versus fast spreading centres, but there is little observational evidence to calibrate these simulations, especially at slow spreading centres. Near the ridge axis, the anisotropic effects of melt versus the lattice preferred orientation of minerals is not well understood. Finally, the mantle flow near ridge-transform interactions is also poorly understood. Here we present observations of SKS splitting in a region of the Mid-Atlantic Ridge near the equator and offset by the Romanche and Chain Fracture Zones. An array of 37 ocean-bottom seismometers were deployed for a year in depths of up to nearly 6000m, with the aim of studying the nature of the lithosphere-asthenosphere boundary as it forms (the PiLAB - Passive Imaging of the lithosphere-asthenosphere boundary - experiment). Stations were deployed on crust that varies from newly formed to 80 My old. We analyse 40 teleseismic events of magnitude greater than 5.8 and with epicentral distances between 88 and 130 degrees. The ocean-bottom is a noisy environment and a range of filters are used to isolate the SKS, SKKS, and related signals. Furthermore, stacking splitting error envelopes is used to improve confidence in the splitting parameters. Many of the splitting measurements show an orientation parallel to the direction of plate spreading, as expected, but variability in the orientation of the anisotropy increases towards the ridge axis. The magnitude of the anisotropy is also quite variable and suggests larger delay times near the ridge axis. Off-axis anisotropy is interpreted in terms of deformation of peridotite due to mantle flow. Near the ridge axis, the effect of ridge-parallel melt

  11. Trace Elements in Basalts From the Siqueiros Fracture Zone: Implications for Melt Migration Models

    Science.gov (United States)

    Pickle, R. C.; Forsyth, D. W.; Saal, A. E.; Nagle, A. N.; Perfit, M. R.

    2008-12-01

    Incompatible trace element (ITE) ratios in MORB from a variety of locations may provide insights into the melt migration process by constraining aggregated melt compositions predicted by mantle melting and flow models. By using actual plate geometries to create a 3-D thermodynamic mantle model, melt volumes and compositions at all depths and locations may be calculated and binned into cubes using the pHMELTS algorithm [Asimow et al., 2004]. These melts can be traced from each cube to the surface assuming several migration models, including a simplified pressure gradient model and one in which melt is guided upwards by a low permeability compacted layer. The ITE ratios of all melts arriving at the surface are summed, averaged, and compared to those of the actual sample compositions from the various MOR locales. The Siqueiros fracture zone at 8° 20' N on the East Pacific Rise (EPR) comprises 4 intra-transform spreading centers (ITSCs) across 140 km of offset between two longer spreading ridges, and is an excellent study region for several reasons. First, an abundance of MORB data is readily available, and the samples retrieved from ITSCs are unlikely to be aggregated in a long-lived magma chamber or affected by along-axis transport, so they represent melts extracted locally from the mantle. Additionally, samples at Siqueiros span a compositional range from depleted to normal MORB within the fracture zone yet have similar isotopic compositions to samples collected from the 9-10° EPR. This minimizes the effect of assuming a uniform source composition in our melting model despite a heterogeneous mantle, allowing us to consistently compare the actual lava composition with that predicted by our model. Finally, it has been demonstrated with preliminary migration models that incipient melts generated directly below an ITSC may not necessarily erupt at that ITSC but migrate laterally towards a nearby ridge due to enhanced pressure gradients. The close proximity of the

  12. Monitoring of polymer melt processing

    International Nuclear Information System (INIS)

    Alig, Ingo; Steinhoff, Bernd; Lellinger, Dirk

    2010-01-01

    The paper reviews the state-of-the-art of in-line and on-line monitoring during polymer melt processing by compounding, extrusion and injection moulding. Different spectroscopic and scattering techniques as well as conductivity and viscosity measurements are reviewed and compared concerning their potential for different process applications. In addition to information on chemical composition and state of the process, the in situ detection of morphology, which is of specific interest for multiphase polymer systems such as polymer composites and polymer blends, is described in detail. For these systems, the product properties strongly depend on the phase or filler morphology created during processing. Examples for optical (UV/vis, NIR) and ultrasonic attenuation spectra recorded during extrusion are given, which were found to be sensitive to the chemical composition as well as to size and degree of dispersion of micro or nanofillers in the polymer matrix. By small-angle light scattering experiments, process-induced structures were detected in blends of incompatible polymers during compounding. Using conductivity measurements during extrusion, the influence of processing conditions on the electrical conductivity of polymer melts with conductive fillers (carbon black or carbon nanotubes) was monitored. (topical review)

  13. Pavement Snow Melting

    Energy Technology Data Exchange (ETDEWEB)

    Lund, John W.

    2005-01-01

    The design of pavement snow melting systems is presented based on criteria established by ASHRAE. The heating requirements depends on rate of snow fall, air temperature, relative humidity and wind velocity. Piping materials are either metal or plastic, however, due to corrosion problems, cross-linked polyethylene pipe is now generally used instead of iron. Geothermal energy is supplied to systems through the use of heat pipes, directly from circulating pipes, through a heat exchanger or by allowing water to flow directly over the pavement, by using solar thermal storage. Examples of systems in New Jersey, Wyoming, Virginia, Japan, Argentina, Switzerland and Oregon are presented. Key words: pavement snow melting, geothermal heating, heat pipes, solar storage, Wyoming, Virginia, Japan, Argentina, Klamath Falls.

  14. Transient fuel melting

    International Nuclear Information System (INIS)

    Roche, L.; Schmitz, F.

    1982-10-01

    The observation of micrographic documents from fuel after a CABRI test leads to postulate a specific mode of transient fuel melting during a rapid nuclear power excursion. When reaching the melt threshold, the bands which are characteristic for the solid state are broken statistically over a macroscopic region. The time of maintaining the fuel at the critical enthalpy level between solid and liquid is too short to lead to a phase separation. A significant life-time (approximately 1 second) of this intermediate ''unsolide'' state would have consequences on the variation of physical properties linked to the phase transition solid/liquid: viscosity, specific volume and (for the irradiated fuel) fission gas release [fr

  15. Sepentinized Peridotite Spinel Composition: Northern Central Indian Ridge at 6°39

    Science.gov (United States)

    Ray, D.; Banerjee, R.; Iyer, S. D.; Balaram, V.; Speakman, J.

    2005-12-01

    Exposures of serpentinized peridotites on the seafloor at slow-spreading ridges have been interpreted either as accretion of ridge segments in a magma-starved condition along the non-transform setting or as preferential outcrops at ridge offsets in transform fault setting. Here we present the mineral chemistry and geochemistry of serpentinites and serpentinized spinel peridotites recovered from an off axis region (corner high) at south of Vityaz transform fault (6°39'S), Northern Central Indian Ridge. Our purpose is to use mineral chemical data of serpentine and spinel to investigate the effect of low temperature alteration processes and degree of partial melting. Serpentine composition shows presence of high Mg-rich lizardite and chrysotile pseudomorphs and these rocks mostly preserve `mesh rim', `window' and `hourglass' textures, representing extensive hydration during low temperature hydrothermal alteration. In thin section, serpentine veins (mainly lensoidal, pinch and swell or anastomosing) are common, sometime crosscutting the `mesh rim' textures to attest to the intensity of serpentinization process. In one sample, a 1.9 cm-thick feldspathic vein crosscut the serpentinite as a porphyroblast and this indicates discontinuity in magmatic crust caused due to less magma input at off-axis region facilitate the intrusion of short-living feeder dykes of highly fractionated late magmatic liquids within the peridotite. In addition, in hand specimen, presence of smaller-scale striations analogous to slickenlines on serpentinite surfaces suggests low-angle faulting, which could have enhanced pervasive serpentinization during their subsequent emplacement. Individual serpentine grain displays very low Ca content (0.01 wt%) suggesting possible absence of any secondary Ca-rich phases also verified by very low Sr content (connotation. Limited data on composition of individual spinel porphyroclast exhibits substantial variation in their Mg# (mole [Mg/ Mg+Fe2]) and Cr# (mole

  16. Entangled Polymer Melts in Extensional Flow

    DEFF Research Database (Denmark)

    Hengeller, Ludovica

    Many commercial materials derived from synthetic polymers exhibit a complex response under different processing operations such as fiber formation, injection moulding,film blowing, film casting or coatings. They can be processed both in the solid or in the melted state. Often they may contain two...... or more different polymers in addition to additives, fillers or solvents in order to modify the properties of the final product. Usually, it is also desired to improve the processability. For example the supplement of a high molecular weight component improves the stability in elongational flows....... Understanding the behaviour of polymer melts and solutions in complex non-linearflows is crucial for the design of polymeric materials and polymer processes. Through rheological characterization, in shear and extensional flow, of model polymer systems,i.e. narrow molar mass distribution polymer melts...

  17. Scrap uranium recycling via electron beam melting

    International Nuclear Information System (INIS)

    McKoon, R.

    1993-11-01

    A program is underway at the Lawrence Livermore National Laboratory (LLNL) to recycle scrap uranium metal. Currently, much of the material from forging and machining processes is considered radioactive waste and is disposed of by oxidation and encapsulation at significant cost. In the recycling process, uranium and uranium alloys in various forms will be processed by electron beam melting and continuously cast into ingots meeting applicable specifications for virgin material. Existing vacuum processing facilities at LLNL are in compliance with all current federal and state environmental, safety and health regulations for the electron beam melting and vaporization of uranium metal. One of these facilities has been retrofitted with an auxiliary electron beam gun system, water-cooled hearth, crucible and ingot puller to create an electron beam melt furnace. In this furnace, basic process R ampersand D on uranium recycling will be performed with the goal of eventual transfer of this technology to a production facility

  18. Emergency preparedness at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Skipper, M.N.

    1990-03-01

    Emergency preparedness for industry was commonly believed to be an essential responsibility on the part of management. Therefore, this study was conducted to research and accumulate information and data on emergency preparedness at Oak Ridge National Laboratory (ORNL). The objective of this study was to conduct a thorough evaluation of emergency preparedness knowledge among employees to determine if they were properly informed or if they needed more training. Also, this study was conducted to provide insight to management as to what their responsibility was concerning this training. To assess employee emergency preparedness knowledge, a questionnaire was developed and administered to 100 employees at ORNL. The data was analyzed using frequencies and percentages of response and was displayed through the use of graphs within the report. 22 refs., 22 figs

  19. Emergency preparedness at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Skipper, M.N.

    1990-03-01

    Emergency preparedness for industry was commonly believed to be an essential responsibility on the part of management. Therefore, this study was conducted to research and accumulate information and data on emergency preparedness at Oak Ridge National Laboratory (ORNL). The objective of this study was to conduct a thorough evaluation of emergency preparedness knowledge among employees to determine if they were properly informed or if they needed more training. Also, this study was conducted to provide insight to management as to what their responsibility was concerning this training. To assess employee emergency preparedness knowledge, a questionnaire was developed and administered to 100 employees at ORNL. The data was analyzed using frequencies and percentages of response and was displayed through the use of graphs within the report. 22 refs., 22 figs.

  20. Metallogenesis along the Indian Ocean Ridge System

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Ray, Dwijesh

    including India. Among these studies majority were concentrated around the Central Indian Ridge and the Southwest Indian Ridge areas, while a few observations were made around the rest of the areas in the IORS. The findings of these studies are discussed...

  1. Sex Determination from Fingerprint Ridge Density | Gungadin ...

    African Journals Online (AJOL)

    This study was conducted with an aim to establish a relationship between sex and fingerprint ridge density. The fingerprints were taken from 500 subjects (250 males and 250 females) in the age group of 18-60 years. After taking fingerprints, the ridges were counted in the upper portion of the radial border of each print for all ...

  2. Differential melt scaling for oblique impacts on terrestrial planets

    Science.gov (United States)

    Abramov, Oleg; Wong, Stephanie M. Wong; Kring, David A. Kring

    2012-01-01

    Analytical estimates of melt volumes produced by a given projectile and contained in a given impact crater are derived as a function of impact velocity, impact angle, planetary gravity, target and projectile densities, and specific internal energy of melting. Applications to impact events and impact craters on the Earth, Moon, and Mars are demonstrated and discussed. The most probable oblique impact (45°) produces ∼1.6 times less melt volume than a vertical impact, and ∼1.6 and 3.7 times more melt volume than impacts with 30° and 15° trajectories, respectively. The melt volume for a particular crater diameter increases with planetary gravity, so a crater on Earth should have more melt than similar-size craters on Mars and the Moon. The melt volume for a particular projectile diameter does not depend on gravity, but has a strong dependence on impact velocity, so the melt generated by a given projectile on the Moon is significantly larger than on Mars. Higher surface temperatures and geothermal gradients increase melt production, as do lower energies of melting. Collectively, the results imply thinner central melt sheets and a smaller proportion of melt particles in impact breccias on the Moon and Mars than on Earth. These effects are illustrated in a comparison of the Chicxulub crater on Earth, linked to the Cretaceous–Tertiary mass extinction, Gusev crater on Mars, where the Mars Exploration Rover Spirit landed, and Tsiolkovsky crater on the Moon. The results are comparable to those obtained from field and spacecraft observations, other analytical expressions, and hydrocode simulations.

  3. Development of high-frequency induction melting system for radioactive solid wastes

    International Nuclear Information System (INIS)

    Kawaguchi, Ichiro; Yamazaki, Seichiro; Takahashi, Noriaki; Kugai, Katsutoshi; Yokozawa, Minoru

    2004-01-01

    Kawasaki Heavy Industries, Ltd. developed an active insulation (AI) method radiofrequency melting system as a new melting treatment system of radioactive solid wastes and proved production of waste satisfied the treatment performances and burying by repeating many practical melting tests. The melting vessel uses a low-priced ceramic canister with nonelectrical conductivity, which is able to treat wastes with large amount of inorganic substances. The wastes melted in the canister is taken out the canister itself from radiofrequency melting reactor and solidified after cooling. The cool canister is stored in 2001 metal drum filling up a gap with mortal for laying underground. New radiofrequency melting reactor, 1/3 scale melting test, estimation of scale effects, melting tests for practical use and the total system are explained. (S.Y.)

  4. Ridge interaction features of the Line Islands

    Science.gov (United States)

    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

  5. Oak Ridge Reservation environmental report for 1991

    International Nuclear Information System (INIS)

    Mucke, P.C.

    1992-10-01

    The Oak Ridge Reservation Environmental Report for 1991 is the 21st in a series that began in 1971. The report documents the annual results of a comprehensive program to estimate the impact of the US Department of Energy (DOE) Oak Ridge operations upon human health and the environment. The report is organized into ten sections that address various aspects of effluent monitoring, environmental surveillance, dose assessment, waste management, and quality assurance. A compliance summary gives a synopsis of the status of each facility relative to applicable state and federal regulations. Data are included for the following: Oak Ridge Y-12 Plant; Oak Ridge National Laboratory (ORNL); and Oak Ridge K-25 Site. Effluent monitoring and environmental surveillance programs are intended to serve as effective indicators of contaminant releases and ambient contaminant concentrations that have the potential to result in adverse impacts to human health and the environment

  6. Interpretation of bathymetric and magnetic data from the easternmost segment of Australian-Antarctic Ridge, 156°-161°E

    Science.gov (United States)

    Choi, H.; Kim, S.; Park, S.

    2013-12-01

    From 2011 to 2013, Korea Polar Research Institute (KOPRI) conducted a series of geophysical and geochemical expeditions on the longest and easternmost segment of Australian-Antarctic Ridge, located at 61°-63°S, and 156°-161°E. This ridge segment plays an important role in constraining the tectonics of the Antarctic plate. Using IBRV ARAON, the detailed bathymetric data and eleven total magnetic profiles were collected. The studied ridge has spread NNW-SSE direction and tends to be shallower to the west and deeper to the east. The western side of the ridge (156°-157.50°E) shows a broad axial high and a plenty of seamounts as an indicative of massive volcanism. Near the center of the ridge (158°-159°E), a seamount chain is formed stretching toward the south from the ridge. Also, the symmetric seafloor fabric is clearly observed at the eastern portion (158.50°-160°E) of the seamount chain. From the topographic change along the ridge axis, the western part of the ridge appears to have a sufficient magma supply. On the contrary, the eastern side of the ridge (160°-161°E) is characterized by axial valley and relatively deeper depth. Nevertheless, the observed total magnetic field anomalies exhibit symmetric patterns across the ridge axis. Although there have not been enough magnetic survey lines, the spreading rates of the ridge are estimated as the half-spreading rate of 37.7 mm/y and 35.3 mm/y for the western portion of the ridge and 42.3 mm/y for the eastern portion. The studied ridge can be categorized as an intermediate spreading ridge, confirming previous studies based on the spreading rate of global ridge system. Here we will present the preliminary results on bathymetric changes along the ridge axis and its relationship with melt supply distribution, and detailed magnetic properties of the ridge constrained by the observed total field anomalies.

  7. Precipitation of metal nitrides from chloride melts

    International Nuclear Information System (INIS)

    Slater, S.A.; Miller, W.E.; Willit, J.L.

    1996-01-01

    Precipitation of actinides, lanthanides, and fission products as nitrides from molten chloride melts is being investigated for use as a final cleanup step in treating radioactive salt wastes generated by electrometallurgical processing of spent nuclear fuel. The radioactive components (eg, fission products) need to be removed to reduce the volume of high-level waste that requires disposal. To extract the fission products from the salt, a nitride precipitation process is being developed. The salt waste is first contacted with a molten metal; after equilibrium is reached, a nitride is added to the metal phase. The insoluble nitrides can be recovered and converted to a borosilicate glass after air oxidation. For a bench-scale experimental setup, a crucible was designed to contact the salt and metal phases. Solubility tests were performed with candidate nitrides and metal nitrides for which there are no solubility data. Experiments were performed to assess feasibility of precipitation of metal nitrides from chloride melts

  8. VIBROCASTING CRUCIBLES OF DIFFERENT COMPOSITION FOR FRYING INDUCTION MELTING ALLOYS

    Directory of Open Access Journals (Sweden)

    V. V. Primachenko

    2012-01-01

    Full Text Available It is shown that PSC «UKRNIIO them. A.S.Berezhnogo  has developed technologies for a wide range of induction melting temperature alloys and started commercial production of crucibles of different composition.

  9. VIBROCASTING CRUCIBLES OF DIFFERENT COMPOSITION FOR FRYING INDUCTION MELTING ALLOYS

    OpenAIRE

    V. V. Primachenko; V. V. Martynenko; I. G. Szulik; S. V. Chaplyanko; L. V. Gritsyuk; L. P. Tkachenko

    2012-01-01

    It is shown that PSC «UKRNIIO them. A.S.Berezhnogo  has developed technologies for a wide range of induction melting temperature alloys and started commercial production of crucibles of different composition.

  10. Heck and Heckle Seamounts, northeast Pacific Ocean: High extrusion rates of primitive and highly depleted mid-ocean ridge basalt on off-ridge seamounts

    Science.gov (United States)

    Leybourne, M. I.; van Wagoner, N. A.

    1991-09-01

    We analyzed, petrographically and chemically, basalt from eight dredge hauls from the Heck and Heckle seamounts, northeast Pacific Ocean. Major elements were determined for mineral, glass, and whole rock samples, and trace and rare earth elements were determined for glass and whole rock samples. The dredge hauls included hyaloclastites and fragments from sheet flows and pillows. The clinkery fragments are interpreted to be deformed sheet flow tops, characteristic of high effusion rates. The hyaloclastites recovered are reworked deposits, as indicated by the wide compositional range of the glass shards, abundance of clay and calcite matrix, and bedding. Most rocks are aphyric, but the analyzed plagioclase and olivine phenocrysts and microcrysts are equilibrium compositions and show minor compositional zonation (up to 7.5% An, chains have a limited range of incompatible element ratios, whereas the adjacent West Valley Segment of the Juan de Fuca Ridge is highly heterogeneous. In contrast, lavas from the East Pacific near-ridge seamounts exhibit a wider range of incompatible element ratios than do the adjacent East Pacific Rise basalts. On the West Valley Segment, magma supply is less robust associated with lower spreading rates compared to the East Pacific Rise at 10°N. In contrast, at fast spreading centers robust melting produces a mixed mantle signature in axial lavas, while suppressed melting at the seamounts reveals the heterogeneities. We suggest that at some spreading ridges, more fertile portions of the mantle are preferentially melted such that the outwelled portions of the mantle tapped by the seamounts are more depleted.

  11. Development and quality assessments of commercial heat production of ATF FeCrAl tubes

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    Development and quality assessment of the 2nd generation ATF FeCrAl tube production with commercial manufacturers were conducted. The manufacturing partners include Sophisticated Alloys, Inc. (SAI), Butler, PA for FeCrAl alloy casting via vacuum induction melting, Oak Ridge National Laboratory (ORNL) for extrusion process to prepare the master bars/tubes to be tube-drawn, and Rhenium Alloys, Inc. (RAI), North Ridgeville, OH, for tube-drawing process. The masters bars have also been provided to Los Alamos National Laboratory (LANL) who works with Century Tubes, Inc., (CTI), San Diego, CA, as parallel tube production effort under the current program.

  12. Chemical, physical, and histologic studies on four commercial apatites used for alveolar ridge augmentation

    DEFF Research Database (Denmark)

    Pinholt, E M; Ruyter, I E; Haanaes, H R

    1992-01-01

    The purpose of this study was to evaluate four commercial apatite products. Subperiosteal alveolar ridge augmentation was performed on the maxilla of rats by implantation of granules of two dense products and of two porous products, and the tissue response was compared with the material character...

  13. Method of melting solid waste

    International Nuclear Information System (INIS)

    Ootsuka, Katsuyuki; Mizuno, Ryokichi; Kuwana, Katsumi; Sawada, Yoshihisa; Komatsu, Fumiaki.

    1982-01-01

    Purpose: To enable the volume reduction treatment of a HEPA filter containing various solid wastes, particularly acid digestion residue, or an asbestos separator at a relatively low temperature range. Method: Solid waste to be heated and molten is high melting point material treated by ''acid digestion treatment'' for treating solid waste, e.g. a HEPA filter or polyvinyl chloride, etc. of an atomic power facility treated with nitric acid or the like. When this material is heated and molten by an electric furnace, microwave melting furnace, etc., boron oxide, sodium boride, sodium carbonate, etc. is added as a melting point lowering agent. When it is molten in this state, its melting point is lowered, and it becomes remarkably fluid, and the melting treatment is facilitated. Solidified material thus obtained through the melting step has excellent denseness and further large volume reduction rate of the solidified material. (Yoshihara, H.)

  14. Logistics Reduction: Heat Melt Compactor

    Data.gov (United States)

    National Aeronautics and Space Administration — The Advanced Exploration Systems (AES) Logistics Reduction (LR) project Heat Melt Compactor (HMC) technology is a waste management technology. Currently, there are...

  15. Melting in trivalent metal chlorides

    International Nuclear Information System (INIS)

    Saboungi, M.L.; Price, D.L.; Scamehorn, C.; Tosi, M.P.

    1990-11-01

    We report a neutron diffraction study of the liquid structure of YCl 3 and combine the structural data with macroscopic melting and transport data to contrast the behaviour of this molten salt with those of SrCl 2 , ZnCl 2 and AlCl 3 as prototypes of different melting mechanisms for ionic materials. A novel melting mechanism for trivalent metal chlorides, leading to a loose disordered network of edge-sharing octahedral units in the liquid phase, is thereby established. The various melting behaviours are related to bonding character with the help of Pettifor's phenomenological chemical scale. (author). 25 refs, 4 figs, 3 tabs

  16. The temperature of primary melts and mantle sources of komatiites, OIBs, MORBs and LIPs

    Science.gov (United States)

    Sobolev, Alexander

    2015-04-01

    There is general agreement that the convecting mantle, although mostly peridotitic in composition, is compositionally and thermally heterogeneous on different spatial scales. The amount, sizes, temperatures and compositions of these heterogeneities significantly affect mantle dynamics because they may diverge greatly from dominant peridotites in their density and fusibility. Differences in potential temperature and composition of mantle domains affect magma production and cannot be easily distinguished from each other. This has led to radically different interpretations of the melting anomalies that produce ocean-island basalts, large igneous provinces and komatiites: most scientists believe that they originate as hot, deep-sourced mantle plumes; but a small though influential group (e.g. Anderson 2005, Foulger, 2010) propose that they derive from high proportions of easily fusible recycled or delaminated crust, or in the case of komatiites contain large amount of H2O (e.g. Grove & Parman, 2004). The way to resolve this ambiguity is an independent estimation of temperature and composition of mantle sources of various types of magma. In this paper I report application of newly developed olivine-spinel-melt geothermometers based on partition of Al, Cr, Sc and Y for different primitive lavas from mid-ocean ridges, ocean-island basalts, large igneous provinces and komatiites. The results suggest significant variations of crystallization temperature for the same Fo of high magnesium olivines of different types of mantle-derived magmas: from the lowest (down to 1220 degree C) for MORB to the highest (up to over 1500 degree C) for komatiites and Siberian meimechites. These results match predictions from Fe-Mg olivine-melt equilibrium and confirm the relatively low temperature of the mantle source of MORB and higher temperatures in the mantle plumes that produce the OIB of Iceland, Hawaii, Gorgona, Archean komatiites and several LIPs (e.g Siberian and NAMP). The

  17. Level 3 Baseline Risk Assessment for Building 3515 at Oak Ridge National Lab., Oak Ridge, TN

    Energy Technology Data Exchange (ETDEWEB)

    Wollert, D.A.; Cretella, F.M.; Golden, K.M. [Univ. of Tennessee, Knoxville, TN (United States)] [and others

    1995-08-01

    The baseline risk assessment for the Fission Product Pilot Plant (Building 3515) at the Oak Ridge National laboratory (ORNL) provides the Decontamination and Decommissioning (D&D) Program at ORNL and Building 3515 project managers with information concerning the results of the Level 3 baseline risk assessment performed for this building. The document was prepared under Work Breakdown Structure 1.4.12.6.2.01 (Activity Data Sheet 3701, Facilities D&D) and includes information on the potential long-term impacts to human health and the environment if no action is taken to remediate Building 3515. Information provided in this document forms the basis for the development of remedial alternatives and the no-action risk portion of the Engineering Evaluation/Cost Analysis report.

  18. Level 3 Baseline Risk Assessment for Building 3515 at Oak Ridge National Lab., Oak Ridge, TN

    International Nuclear Information System (INIS)

    Wollert, D.A.; Cretella, F.M.; Golden, K.M.

    1995-08-01

    The baseline risk assessment for the Fission Product Pilot Plant (Building 3515) at the Oak Ridge National laboratory (ORNL) provides the Decontamination and Decommissioning (D ampersand D) Program at ORNL and Building 3515 project managers with information concerning the results of the Level 3 baseline risk assessment performed for this building. The document was prepared under Work Breakdown Structure 1.4.12.6.2.01 (Activity Data Sheet 3701, Facilities D ampersand D) and includes information on the potential long-term impacts to human health and the environment if no action is taken to remediate Building 3515. Information provided in this document forms the basis for the development of remedial alternatives and the no-action risk portion of the Engineering Evaluation/Cost Analysis report

  19. Melting method for miscellaneous radioactive solid waste and melting furnace

    International Nuclear Information System (INIS)

    Osaki, Toru; Furukawa, Hirofumi; Uda, Nobuyoshi; Katsurai, Kiyomichi

    1998-01-01

    A vessel containing miscellaneous solid wastes is inserted in a crucible having a releasable material on the inner surface, they are induction-heated from the outside of the crucible by way of low temperature heating coils to melt low melting point materials in the miscellaneous wastes within a temperature range at which the vessel does not melt. Then, they are induction-heated by way of high temperature heating coils to melt the vessel and not yet melted materials, those molten materials are cooled, solidified molten material and the releasable material are taken out, and then the crucible is used again. Then, the crucible can be used again, so that it can be applied to a large scaled melting furnace which treats wastes by a unit of drum. In addition, since the cleaning of the used crucible and the application of the releasable material can be conducted without interrupting the operation of the melting furnace, the operation cycle of the melting furnace can be shortened. (N.H.)

  20. Waste glass melting stages

    International Nuclear Information System (INIS)

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1994-01-01

    Three simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C to 1000 degrees C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentru Karlsruhe (KfK) in Germany were used. The samples were thin sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. The behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied. 2 refs., 8 tabs

  1. Waste glass melting stages

    International Nuclear Information System (INIS)

    Anderson, L.D.; Dennis, T.; Elliott, M.L.; Hrma, P.

    1993-04-01

    Three different simulated nuclear waste glass feeds, consisting of dried waste and glass frit, were heat treated for 1 hour in a gradient furnace at temperatures ranging from approximately 600 degrees C--1000 degrees C. Simulated melter feeds from the Hanford Waste Vitrification Plant (HWVP), the Defense Waste Processing Facility (DWPF), and Kernforschungszentrum Karlsruhe (KfK) in Germany were used. The samples were thin-sectioned and examined by optical microscopy to investigate the stages of the conversion from feed to glass. Various phenomena were seen, such as frit softening, bubble formation, foaming, bubble motion and removal, convective mixing, and homogenization. Behavior of different feeds was similar, although the degree of gas generation and melt homogenization varied

  2. Oak Ridge rf Test Facility

    International Nuclear Information System (INIS)

    Gardner, W.L.; Hoffman, D.J.; McCurdy, H.C.; McManamy, T.J.; Moeller, J.A.; Ryan, P.M.

    1985-01-01

    The rf Test Facility (RFTF) of Oak Ridge National Laboratory (ORNL) provides a national facility for the testing and evaluation of steady-state, high-power (approx.1.0-MW) ion cyclotron resonance heating (ICRH) systems and components. The facility consists of a vacuum vessel and two fully tested superconducting development magnets from the ELMO Bumpy Torus Proof-of-Principle (EBT-P) program. These are arranged as a simple mirror with a mirror ratio of 4.8. The axial centerline distance between magnet throat centers is 112 cm. The vacuum vessel cavity has a large port (74 by 163 cm) and a test volume adequate for testing prototypic launchers for Doublet III-D (DIII-D), Tore Supra, and the Tokamak Fusion Test Reactor (TFTR). Attached to the internal vessel walls are water-cooled panels for removing the injected rf power. The magnets are capable of generating a steady-state field of approx.3 T on axis in the magnet throats. Steady-state plasmas are generated in the facility by cyclotron resonance breakdown using a dedicated 200-kW, 28-GHz gyrotron. Available rf sources cover a frequency range of 2 to 200 MHz at 1.5 kW and 3 to 18 MHz at 200 kW, with several sources at intermediate parameters. Available in July 1986 will be a >1.0-MW, cw source spanning 40 to 80 MHz. 5 figs

  3. Oak Ridge National Laboratory's isotope enrichment program

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.C.

    1997-01-01

    The Isotope Enrichment Program (IEP) at Oak Ridge National Laboratory (ORNL) is responsible for the production and distribution of ∼225 enriched stable isotopes from 50 multi-isotopic elements. In addition, ORNL distributes enriched actinide isotopes and provides extensive physical- and chemical-form processing of enriched isotopes to meet customer requirements. For more than 50 yr, ORNL has been a major provider of enriched isotopes and isotope-related services to research, medical, and industrial institutions throughout the world. Consolidation of the Isotope Distribution Office (IDO), the Isotope Research Materials Laboratory (IRML), and the stable isotope inventories in the Isotope Enrichment Facility (IEF) have improved operational efficiencies and customer services. Recent changes in the IEP have included adopting policies for long-term contracts, which offer program stability and pricing advantages for the customer, and prorated service charges, which greatly improve pricing to the small research users. The former U.S. Department of Energy (DOE) Loan Program has been converted to a lease program, which makes large-quantity or very expensive isotopes available for nondestructive research at a nominal cost. Current efforts are being pursued to improve and expand the isotope separation capabilities as well as the extensive chemical- and physical-form processing that now exists. The IEF's quality management system is ISO 9002 registered and accredited in the United States, Canada, and Europe

  4. Magdalena Ridge Observatory Interferometer: Status Update

    National Research Council Canada - National Science Library

    Creech-Eakman, M. J; Bakker, E. J; Buscher, D. F; Coleman, T. A; Haniff, C. A; Jurgenson, C. A; Klinglesmith, III, D. A; Parameswariah, C. B; Romero, V. D; Shtromberg, A. V; Young, J. S

    2006-01-01

    The Magdalena Ridge Observatory Interferometer (MROI) is a ten element optical and near-infrared imaging interferometer being built in the Magdalena mountains west of Socorro, NM at an altitude of 3230 m...

  5. A deep structural ridge beneath central India

    Science.gov (United States)

    Agrawal, P. K.; Thakur, N. K.; Negi, J. G.

    A joint-inversion of magnetic satellite (MAGSAT) and free air gravity data has been conducted to quantitatively investigate the cause for Bouguer gravity anomaly over Central Indian plateaus and possible fold consequences beside Himalayan zone in the Indian sub-continent due to collision between Indian and Eurasian plates. The appropriate inversion with 40 km crustal depth model has delineated after discriminating high density and magnetisation models, for the first time, about 1500 km long hidden ridge structure trending NW-SE. The structure is parallel to Himalayan fold axis and the Indian Ocean ridge in the Arabian Sea. A quantitative relief model across a representative anomaly profile confirms the ridge structure with its highest point nearly 6 km higher than the surrounding crustal level in peninsular India. The ridge structure finds visible support from the astro-geoidal contours.

  6. Rhenium corrosion in chloride melts

    International Nuclear Information System (INIS)

    Stepanov, A.D.; Shkol'nikov, S.N.; Vetyukov, M.M.

    1989-01-01

    The results investigating rhenium corrosion in chloride melts containing sodium, potassium and chromium ions by a gravimetry potentials in argon atmosphere in a sealing quarth cell are described. Rhenium corrosion is shown to be rather considerable in melts containing CrCl 2 . The value of corrosion rate depending on temperature is determined

  7. UNCONSTRAINED MELTING AND SOLIDIFICATION INSIDE ...

    African Journals Online (AJOL)

    2015-09-01

    Sep 1, 2015 ... There is a large number of experimental and numerical works on melting and solidification of PCM[6-10], and also its usage as thermal management in building [11-14], electronic devices [15-16] and solar energy. [17-20].Most investigated geometries in melting and freezing process are sphere (spherical.

  8. The interaction of a core melt with concrete

    International Nuclear Information System (INIS)

    Reimann, M.; Holleck, H.; Skokan, A.; Perinic, D.

    1977-01-01

    In its fourth phase, a hypothetic core melt interacts with the concrete of the reactor foundation. This phase may last several days. Experimental laboratory investigations and theoretical models on the basis of model experiments aim at determining the time curve of the temperature of the core melt in order to quantify the processes up to the solidification of the melt and the end of concrete destroyal. Material interactions: 1) The two phases of the core melt, oxidic and metallic, remain separate for a long period of time. In dependence of the degree of oxidation of the system, the elemental distribution and, in particular, the fission products in the melt may be assessed. 2) The changes in the material values of the core melt in dependence of the temperature curve may be qualitatively assessed. 3) The solidification temperature of the oxidic phase of the core melt may be given in dependence of (UO 2 + ZrO 2 ) content. Thermal interactions: 1) The ratio vertical/radial erosion, which determines the cavity shape, is described in the correct order of magnitude by the extended film model. 2) The correct order of magnitude of the erosion rates is described by the concrete destruction model coupled with the film model. 3) The effects of the different concrete destruction enthalpies and concrete compositions (amount of gaseous decomposition products) may be estimated by the model calculations. (orig./HP) [de

  9. Induction melting of simulated transuranic waste

    International Nuclear Information System (INIS)

    Tenaglia, R.D.; McCall, J.L.

    1983-06-01

    Coreless induction melting was investigated as a method to melt and consolidate waste material representative of the transuranic waste (TRU) stored at the Idaho National Engineering Laboratory (INEL). Waste material was introduced onto the surface of a molten cast iron bath in a coreless induction furnace. Waste metallics were incorporated into the bath. Noncombustibles formed a slag which was poured or skimmed from the bath surface. Stack sampling was performed to characterize the off-gas and particulate matter evolved. Experimental melting tests were performed for a variety of types of wastes including metallics, chemical sludge, soil, concrete, and glass. Each test also included a representative level of combustible materials consisting of paper, wood, cloth, polyvinyl chloride and polyethylene. Metallic wastes were readily processed by induction melting with a minimum of slag production. Test waste consisting primarily of chemical sludge provided fluid slags which could be poured from the bath surface. Processing of wastes consisting of soil, concrete, or glass was limited by the inability to achieve fluid slags. It appears from test results that coreless induction melting is a feasible method to process INEL-type waste materials if two problems can be resolved. First, slag fluidity must be improved to facilitate the collection of slags formed from soil, concrete, or glass containing wastes. Secondly, refractory life must be further optimized to permit prolonged processing of the waste materials. The use of a chrome-bearing high-alumina refractory was found to resist slag line attach much better than a magnesia refractory, although some attack was still noted

  10. In vessel core melt progression phenomena

    International Nuclear Information System (INIS)

    Courtaud, M.

    1993-01-01

    For all light water reactor (LWR) accidents, including the so called severe accidents where core melt down can occur, it is necessary to determine the amount and characteristics of fission products released to the environment. For existing reactors this knowledge is used to evaluate the consequences and eventual emergency plans. But for future reactors safety authorities demand decrease risks and reactors designed in such a way that fission products are retained inside the containment, the last protective barrier. This requires improved understanding and knowledge of all accident sequences. In particular it is necessary to be able to describe the very complex phenomena occurring during in vessel core melt progression because they will determine the thermal and mechanical loads on the primary circuit and the timing of its rupture as well as the fission product source term. On the other hand, in case of vessel failure, knowledge of the physical and chemical state of the core melt will provide the initial conditions for analysis of ex-vessel core melt progression and phenomena threatening the containment. Finally a good understanding of in vessel phenomena will help to improve accident management procedures like Emergency Core Cooling System water injection, blowdown and flooding of the vessel well, with their possible adverse effects. Research and Development work on this subject was initiated a long time ago and is still in progress but now it must be intensified in order to meet the safety requirements of the next generation of reactors. Experiments, limited in scale, analysis of the TMI 2 accident which is a unique source of global information and engineering judgment are used to establish and assess physical models that can be implemented in computer codes for reactor accident analysis

  11. Melting behaviour of raw materials and recycled stone wool waste

    DEFF Research Database (Denmark)

    Schultz-Falk, Vickie; Agersted, Karsten; Jensen, Peter Arendt

    2018-01-01

    Stone wool is a widely used material for building insulation, to provide thermal comfort along with fire stability and acoustic comfort for all types of buildings. Stone wool waste generated either during production or during renovation or demolition of buildings can be recycled back into the sto...... wool melt production. This study investigates and compares the thermal response and melting behaviour of a conventional stone wool charge and stone wool waste. The study combines differential scanning calorimetry (DSC), hot stage microscopy (HSM) and X-ray diffraction (XRD). DSC reveals...... that the conventional charge and stone wool waste have fundamentally different thermal responses, where the charge experiences gas release, phase transition and melting of the individual raw materials. The stone wool waste experiences glass transition, crystallization and finally melting. Both DSC and HSM measurements...

  12. Method of melting to solidify radioactive powder wastes

    International Nuclear Information System (INIS)

    Ootsuka, Katsuyuki; Miyazaki, Hitoshi.

    1981-01-01

    Purpose: To improve the microwave irradiation efficiency in a melting furnace. Constitution: Pelletization, sludgification and granularization are carried out as powderous dust reducing treatment. In the granularization, for example, radioactive burning ashes are sent from a hopper to a mixer and mixed with processing aids such as binders. Then, they are pelletized in a pelletizer into granular products and sent to a microwave melting furnace by way of a sieve screen. The granular products are melted by microwaves from a microwave guide tube and taken out through an exit. This can prevent powderous dusts from floating and scattering in the melting furnace and prevent the reduction in the microwave irradiation efficiency due to generation of electric discharges. (Seki, T.)

  13. Oak Ridge Reservation annual site environmental report for 2008

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2009-09-01

    The Oak Ridge Reservation (ORR) consists of three major government-owned, contractor-operated facilities: the Y-12 National Security Complex, Oak Ridge National Laboratory, and East Tennessee Technology Park. The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced materials for the first atomic bombs. The reservation’s role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the United States. Both the work carried out for the war effort and subsequent research, development, and production activities have involved, and continue to involve, the use of radiological and hazardous materials. The Oak Ridge Reservation Annual Site Environmental Report and supporting data are available at http://www.ornl.gov/sci/env_rpt or from the project director. This document is prepared annually to summarize environmental activities, primarily environmental monitoring activities, on the Oak Ridge Reservation (ORR) and within the ORR surroundings. The document fulfills the requirement of Department of Energy (DOE) Order 231.1A, Environment, Safety and Health Reporting, for an annual summary of environmental data to characterize environmental performance. The environmental monitoring criteria are described in DOE Order 450.1A, Environmental Protection Program. The results summarized in this report are based on data collected prior to and through 2008. This report is not intended to provide the results of all sampling on the ORR. Additional data collected for other site and regulatory purposes, such as environmental restoration/remedial investigation reports, waste management characterization sampling data, and environmental permit compliance data, are presented in other documents that have been prepared in accordance with applicable DOE guidance and/or laws and are referenced herein as appropriate. Corrections to the report for the previous year are found in Appendix

  14. Recycling of aluminium swarf by direct incorporation in aluminium melts

    OpenAIRE

    Puga, Hélder; Barbosa, J.; Soares, Delfim; Silva, Filipe Samuel; Ribeiro, Carlos Silva

    2009-01-01

    The purpose of this work was to recover a standard AlSi12Cu1 alloy from machining chips inside the foundry plant, by using an environmentally friend technique to produce cast ingots with characteristics similar to those of the commercially available 2nd melt raw material. The recyclability of aluminium swarf using different melting techniques and the influence of chips preparation in the aluminium alloy recovery rate and dross production was experimentally studied and evaluated...

  15. Reactive Melt Infiltration Of Silicon Into Porous Carbon

    Science.gov (United States)

    Behrendt, Donald R.; Singh, Mrityunjay

    1994-01-01

    Report describes study of synthesis of silicon carbide and related ceramics by reactive melt infiltration of silicon and silicon/molybdenum alloys into porous carbon preforms. Reactive melt infiltration has potential for making components in nearly net shape, performed in less time and at lower temperature. Object of study to determine effect of initial pore volume fraction, pore size, and infiltration material on quality of resultant product.

  16. Nickel and helium evidence for melt above the core-mantle boundary.

    Science.gov (United States)

    Herzberg, Claude; Asimow, Paul D; Ionov, Dmitri A; Vidito, Chris; Jackson, Matthew G; Geist, Dennis

    2013-01-17

    High (3)He/(4)He ratios in some basalts have generally been interpreted as originating in an incompletely degassed lower-mantle source. This helium source may have been isolated at the core-mantle boundary region since Earth's accretion. Alternatively, it may have taken part in whole-mantle convection and crust production over the age of the Earth; if so, it is now either a primitive refugium at the core-mantle boundary or is distributed throughout the lower mantle. Here we constrain the problem using lavas from Baffin Island, West Greenland, the Ontong Java Plateau, Isla Gorgona and Fernandina (Galapagos). Olivine phenocryst compositions show that these lavas originated from a peridotite source that was about 20 per cent higher in nickel content than in the modern mid-ocean-ridge basalt source. Where data are available, these lavas also have high (3)He/(4)He. We propose that a less-degassed nickel-rich source formed by core-mantle interaction during the crystallization of a melt-rich layer or basal magma ocean, and that this source continues to be sampled by mantle plumes. The spatial distribution of this source may be constrained by nickel partitioning experiments at the pressures of the core-mantle boundary.

  17. DEPENDENCY OF SULFATE SOLUBILITY ON MELT COMPOSITION AND MELT POLYMERIZATION

    International Nuclear Information System (INIS)

    JANTZEN, CAROL M.

    2004-01-01

    Sulfate and sulfate salts are not very soluble in borosilicate waste glass. When sulfate is present in excess it can form water soluble secondary phases and/or a molten salt layer (gall) on the melt pool surface which is purported to cause steam explosions in slurry fed melters. Therefore, sulfate can impact glass durability while formation of a molten salt layer on the melt pool can impact processing. Sulfate solubility has been shown to be compositionally dependent in various studies, (e.g. , B2O3, Li2O, CaO, MgO, Na2O, and Fe2O3 were shown to increase sulfate solubility while Al2O3 and SiO2 decreased sulfate solubility). This compositional dependency is shown to be related to the calculated melt viscosity at various temperatures and hence the melt polymerization

  18. Preliminary results from the first InRidge cruise to the central Indian Ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Mukhopadhyay, R.; Murthy, K.S.R.; Iyer, S.D.; Rao, M.M.M.; Banerjee, R.; Subrahmanyam, A.S.; Shirodkar, P.V.; Ghose, I.; Ganesan, P.; Rao, A.K.; Suribabu, A.; Ganesh, C.; Naik, G.P.

    stream_size 1 stream_content_type text/plain stream_name Inter_Ridge_News_7_40.pdf.txt stream_source_info Inter_Ridge_News_7_40.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  19. Plasma arc melting of zirconium

    International Nuclear Information System (INIS)

    Tubesing, P.K.; Korzekwa, D.R.; Dunn, P.S.

    1997-01-01

    Zirconium, like some other refractory metals, has an undesirable sensitivity to interstitials such as oxygen. Traditionally, zirconium is processed by electron beam melting to maintain minimum interstitial contamination. Electron beam melted zirconium, however, does not respond positively to mechanical processing due to its large grain size. The authors undertook a study to determine if plasma arc melting (PAM) technology could be utilized to maintain low interstitial concentrations and improve the response of zirconium to subsequent mechanical processing. The PAM process enabled them to control and maintain low interstitial levels of oxygen and carbon, produce a more favorable grain structure, and with supplementary off-gassing, improve the response to mechanical forming

  20. An Account of Oak Ridge National Laboratory's Thirteen Research Reactors

    International Nuclear Information System (INIS)

    Rosenthal, Murray Wilford

    2009-01-01

    The Oak Ridge National Laboratory has built and operated 13 nuclear reactors in its 66-year history. The first was the graphite reactor, the world's first operational nuclear reactor, which served as a plutonium production pilot plant during World War II. It was followed by two aqueous-homogeneous reactors and two red-hot molten-salt reactors that were parts of power-reactor development programs and by eight others designed for research and radioisotope production. One of the eight was an all-metal fast burst reactor used for health physics studies. All of the others were light-water cooled and moderated, including the famous swimming-pool reactor that was copied dozens of times around the world. Two of the reactors were hoisted 200 feet into the air to study the shielding needs of proposed nuclear-powered aircraft. The final reactor, and the only one still operating today, is the High Flux Isotope Reactor (HFIR) that was built particularly for the production of californium and other heavy elements. With the world's highest flux and recent upgrades that include the addition of a cold neutron source, the 44-year-old HFIR continues to be a valuable tool for research and isotope production, attracting some 500 scientific visitors and guests to Oak Ridge each year. This report describes all of the reactors and their histories.

  1. Role of crucible partition in improving Czochralski melt conditions

    Science.gov (United States)

    Jafri, I. H.; Prasad, V.; Anselmo, A. P.; Gupta, K. P.

    1995-09-01

    Many of the inhomogeneities and defects in the crystal grown from a pool of melt are because of the inherent unsteady growth kinetics and flow instabilities of the process. A scaled up version of the Czochralski process induces oscillatory and turbulent conditions in the melt, thereby resulting in the production of non-uniform silicon crystals. This numerical study reveals that a crucible partition shorter than the melt height can significantly improve the melt conditions. The obstruction at the bottom of the crucible is helpful but the variations in heat flux and flow patterns remain random. However, when the obstruction is introduced at the top of the melt, the flow conditions become much more desirable and oscillations are greatly suppressed. It is also found that a full-melt height partition or a double-crucible may not be a good choice. An optimal size of the blockage and its location to produce the most desirable process conditions will depend on the growth parameters including the melt height and the crucible diameter. These findings should be particularly useful in designing a solid polysilicon pellets-feed continuous Czochralski process for Si crystals.

  2. Transition in the fractal geometry of Arctic melt ponds

    Directory of Open Access Journals (Sweden)

    C. Hohenegger

    2012-10-01

    Full Text Available During the Arctic melt season, the sea ice surface undergoes a remarkable transformation from vast expanses of snow covered ice to complex mosaics of ice and melt ponds. Sea ice albedo, a key parameter in climate modeling, is determined by the complex evolution of melt pond configurations. In fact, ice–albedo feedback has played a major role in the recent declines of the summer Arctic sea ice pack. However, understanding melt pond evolution remains a significant challenge to improving climate projections. By analyzing area–perimeter data from hundreds of thousands of melt ponds, we find here an unexpected separation of scales, where pond fractal dimension D transitions from 1 to 2 around a critical length scale of 100 m2 in area. Pond complexity increases rapidly through the transition as smaller ponds coalesce to form large connected regions, and reaches a maximum for ponds larger than 1000 m2, whose boundaries resemble space-filling curves, with D ≈ 2. These universal features of Arctic melt pond evolution are similar to phase transitions in statistical physics. The results impact sea ice albedo, the transmitted radiation fields under melting sea ice, the heat balance of sea ice and the upper ocean, and biological productivity such as under ice phytoplankton blooms.

  3. Origin of lavas from the Ninetyeast Ridge, Eastern Indian Ocean: An evaluation of fractional crystallization models

    Energy Technology Data Exchange (ETDEWEB)

    Ludden, J.N.; Thompson, G.; Bryan, W.B.; Frey, F.A.

    1980-08-10

    Ferrobasalts from DSDP sites 214 and 216 on the Ninetyeast Ridge are characterized by high absolute iron (FeO>12.9 wt %), FeO/MgO>1.9, and TiO/sub 2/>2.0 wt %. Their trace element abundances indicate a tholeiitic affinity; however, they are distinct from midocean ridge incompatible element-depleted tholeiites owing to higher contents of Ba, Zr, and Sr and flat to slightly light-REE-enriched, chondrite-normalized REE patterns. Calculations using major and trace element abundances and phase compositions are generally consistent with a model relating most major elements and phase compositions in site 214 and 216 ferrobasalts by fractionation of clinopyroxene and plagio-class. However, some incompatible element abundances for site 216 basalts are not consistent with the fractional crystallization models. Baslats from site 214 can be related to andesitic rocks from the same site by fractionating clinopyroxene, plagioclase and titanomagnetite. Site 254 basalts, at the southern end of the Ninetyeast Ridge, and island tholeiites in the southern Indian Ocean (Amsterdam-St. Paul or Kerguelen-Heard volcanic provinces) possibly represent the most recent activity associated with a hot spot forming the Ninetyeast Ridge. These incompatible-element-enriched tholeiites have major element compositions consistent with those expected for a parental liquid for the site 214 and 216 ferrobasalts. However, differences in the trace element contents of the basalts from the Ninetyeast Ridge sites are not consistent with simple fractional crystallization derivation but require either a complex melting model or a heterogeneous mantle source.

  4. Remedial Investigation Work Plan for Chestnut Ridge Operable Unit 1 (Chestnut Ridge Security Pits) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1994-03-01

    This document outlines the activities necessary to conduct a Remedial Investigation (RI) of the Chestnut Ridge Security Pits (CRSP) at the Oak Ridge Y-12 Plant. The CRSP, also designated Chestnut Ridge Operable Unit (OU) 1, is one of four OUs along Chestnut Ridge on the Oak Ridge Reservation (ORR). The purpose of the RI is to collect data to (1) evaluate the nature and extent of known and suspected contaminants, (2) support an Ecological Risk Assessment (ERA) and a Human Health Risk Assessment (HHRA), (3) support the feasibility study in the development and analysis of remedial alternatives, and (4) ultimately, develop a Record of Decision (ROD) for the site. This chapter summarizes the regulatory background of environmental investigation on the ORR and the approach currently being followed and provides an overview of the RI to be conducted at the CRSP. Subsequent chapters provide details on site history, sampling activities, procedures and methods, quality assurance (QA), health and safety, and waste management related to the RI

  5. Remedial Investigation Work Plan for Chestnut Ridge Operable Unit 1 (Chestnut Ridge Security Pits) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1994-03-01

    This document outlines the activities necessary to conduct a Remedial Investigation (RI) of the Chestnut Ridge Security Pits (CRSP) at the Oak Ridge Y-12 Plant. The CRSP, also designated Chestnut Ridge Operable Unit (OU) 1, is one of four OUs along Chestnut Ridge on the Oak Ridge Reservation (ORR). The purpose of the RI is to collect data to (1) evaluate the nature and extent of known and suspected contaminants, (2) support an Ecological Risk Assessment (ERA) and a Human Health Risk Assessment (HHRA), (3) support the feasibility study in the development and analysis of remedial alternatives, and (4) ultimately, develop a Record of Decision (ROD) for the site. This chapter summarizes the regulatory background of environmental investigation on the ORR and the approach currently being followed and provides an overview of the RI to be conducted at the CRSP. Subsequent chapters provide details on site history, sampling activities, procedures and methods, quality assurance (QA), health and safety, and waste management related to the RI.

  6. Nitrogen Control in VIM Melts

    Science.gov (United States)

    Jablonski, P. D.; Hawk, J. A.

    NETL has developed a design and control philosophy for the addition of nitrogen to austenitic and ferritic steels. The design approach uses CALPHAD as the centerpiece to predict the level to which nitrogen is soluble in both the melt and the solid. Applications of this technique have revealed regions of "exclusion" in which the alloy, while within specification limits of prescribed, cannot be made by conventional melt processing. Furthermore, other investigations have found that substantial retrograde solubility of nitrogen exists, which can become problematic during subsequent melt processing and/or other finishing operations such as welding. Additionally, the CALPHAD method has been used to adjust primary melt conditions. To that end, nitrogen additions have been made using chrome nitride, silicon nitride, high-nitrogen ferrochrome as well as nitrogen gas. The advantages and disadvantages of each approach will be discussed and NETL experience in this area will be summarized with respect to steel structure.

  7. Theoretical melting curve of caesium

    International Nuclear Information System (INIS)

    Simozar, S.; Girifalco, L.A.; Pennsylvania Univ., Philadelphia

    1983-01-01

    A statistical-mechanical model is developed to account for the complex melting curve of caesium. The model assumes the existence of three different species of caesium defined by three different electronic states. On the basis of this model, the free energy of melting and the melting curve are computed up to 60 kbar, using the solid-state data and the initial slope of the fusion curve as input parameters. The calculated phase diagram agrees with experiment to within the experimental error. Other thermodynamic properties including the entropy and volume of melting were also computed, and they agree with experiment. Since the theory requires only one adjustable constant, this is taken as strong evidence that the three-species model is satisfactory for caesium. (author)

  8. Melting curves of gammairradiated DNA

    International Nuclear Information System (INIS)

    Hofer, H.; Altmann, H.; Kehrer, M.

    1978-08-01

    Melting curves of gammairradiated DNA and data derived of them, are reported. The diminished stability is explained by basedestruction. DNA denatures completely at room temperature, if at least every fifth basepair is broken or weakened by irradiation. (author)

  9. Pressure melting and ice skating

    Science.gov (United States)

    Colbeck, S. C.

    1995-10-01

    Pressure melting cannot be responsible for the low friction of ice. The pressure needed to reach the melting temperature is above the compressive failure stress and, if it did occur, high squeeze losses would result in very thin films. Pure liquid water cannot coexist with ice much below -20 °C at any pressure and friction does not increase suddenly in that range. If frictional heating and pressure melting contribute equally, the length of the wetted contact could not exceed 15 μm at a speed of 5 m/s, which seems much too short. If pressure melting is the dominant process, the water films are less than 0.08 μm thick because of the high pressures.

  10. Californium-252 sales and loans at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    King, L.J.

    1987-01-01

    The production and distribution in the United States of 252 Cf has recently been consolidated at the Oak Ridge National Laboratory (ORNL). The 252 Cf Industrial Sales/Loan Program and the 252 Cf University Load Program, which were formerly located at the Savannah River Plant (SRP), have been combined with the californium production and distribution activities of the Transuranium Element Production Program at ORNL. Californium-252 is sold to commercial users in the form of bulk californium oxide, palladium-californium alloy pellets, or alloy wires. Neutron source capsules, which are fabricated for loans to DOE or other US government agencies, are still available in all forms previously available. The consolidation of all 252 Cf distribution activities at the production site is expected to result in better service to users. In particular, customers for neutrons sources will be ale to select from a wider range of neutron source forms, including custom designs, through a single contact point

  11. Treatment of contaminated wastewater at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Robinson, S.M.; Kent, T.E.; Arnold, W.D.

    1993-01-01

    Oak Ridge National Laboratory (ORNL), an energy research and radioisotope production facility, operates two centralized liquid waste treatment systems, one for liquid low-level waste (LLLW) system and the other for process waste (PW). New regulatory and waste minimization requirements have led ORNL to consider zeolite ion exchangers for removing cesium and strontium from LLLW and PW streams for their economic advantages, selective molecular sieve properties, and ease of disposal. Natural and synthetic zeolites have been compared with inorganic and organic ion exchangers for these applications

  12. Environmental assessment. Y-12 Plant Site, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1982-12-01

    The Oak Ridge Y-12 Plant, operated by Union Carbide Corporation, Nuclear Division, under contract to the US Department of Energy (DOE), has the following five major responsibilities: production of nuclear weaposn components; fabrication support for weapon design agencies; support for other UCC-ND installations; support and assistance to otehr government agencies; and processing of source and special nuclear materials. This Environmental Assessment describesthe ongoing opertions of Y-12 and evaluates the actual and possible impacts on the environment that continuation of these operatios entails. Information is presented under the following section headings: purpose and need for the proposed action; alternatives; affected environment;; and, environmental consequences

  13. Observation of melting conditions in selective laser melting of metals (SLM)

    Science.gov (United States)

    Thombansen, U.; Abels, Peter

    2016-03-01

    Process observation in 3D printing of metals currently is one of the central challenges. Many companies strive to employ this additive manufacturing process in their production chains in order to gain competitive advantages through added flexibility in product design and embedded features. The new degrees of freedom are accompanied with the challenge to manufacture every detail of the product to the predefined specifications. Products with filigree internal structures for example require a perfect build to deliver the performance that was designed into these structures. Melting conditions determine properties such as grain structure and density of the finished part before it is sent to post processing steps. Monitoring of such melting conditions is still a challenge where the use of photodiodes, pyrometry and camera systems contribute to an overall picture that might identify errors or deviations during the build process. Additional considerations must be made to decide if these sensors are applied coaxially or from a lateral perspective. Furthermore, setting parameters of focal plane array (FPA) sensors are discussed and events that are seen in the machine vision image are compared against the pyrometry data. The resume of the experiments suggests the application of multiple sensors to the selective laser melting process (SLM) as they jointly contribute to an identification of events. These events need to be understood in order to establish cause effect relationships in the future.

  14. Melting in super-earths.

    Science.gov (United States)

    Stixrude, Lars

    2014-04-28

    We examine the possible extent of melting in rock-iron super-earths, focusing on those in the habitable zone. We consider the energetics of accretion and core formation, the timescale of cooling and its dependence on viscosity and partial melting, thermal regulation via the temperature dependence of viscosity, and the melting curves of rock and iron components at the ultra-high pressures characteristic of super-earths. We find that the efficiency of kinetic energy deposition during accretion increases with planetary mass; considering the likely role of giant impacts and core formation, we find that super-earths probably complete their accretionary phase in an entirely molten state. Considerations of thermal regulation lead us to propose model temperature profiles of super-earths that are controlled by silicate melting. We estimate melting curves of iron and rock components up to the extreme pressures characteristic of super-earth interiors based on existing experimental and ab initio results and scaling laws. We construct super-earth thermal models by solving the equations of mass conservation and hydrostatic equilibrium, together with equations of state of rock and iron components. We set the potential temperature at the core-mantle boundary and at the surface to the local silicate melting temperature. We find that ancient (∼4 Gyr) super-earths may be partially molten at the top and bottom of their mantles, and that mantle convection is sufficiently vigorous to sustain dynamo action over the whole range of super-earth masses.

  15. Melting the vacuum

    International Nuclear Information System (INIS)

    Rafelski, J.

    1998-01-01

    Results presented at the Quark Matter 97 conference, held in December in Tsukuba, Japan, have provided new insights into the confinement of quarks in matter. The current physics paradigm is that the inertial masses of protons and neutrons, and hence of practically all of the matter around us, originate in the zero-point energy caused by the confinement of quarks inside the small volume of the nucleon. Today, 25 years after Harald Fritzsch, Heinrich Leutwyler and Murray Gell-Mann proposed quantum chromodynamics (QCD) as a means for understanding strongly interacting particles such as nucleons and mesons, our understanding of strong interactions and quark confinement remains incomplete. Quarks and the gluons that bind them together have a ''colour'' charge that may be red, green or blue. But quarks are seen in particles that are white: baryons such as protons and neutrons consist of three quarks with different colour charges, while mesons consist of a quark and an antiquark, and again the colour charge cancels out. To prove that confinement arises from quark-gluon fluctuations in the vacuum that quantum theories dictate exists today, we need to find a way of freeing the colour charge of quarks. Experiments must therefore ''melt'' the vacuum to deconfine quarks and the colour charge. By colliding nuclei at high energies, we hope to produce regions of space filled with free quarks and gluons. This deconfined phase is known as the quark-gluon plasma. At the Tsukuba meeting, Scott Pratt of Michigan State University in the US discussed measurements that show that the hot dense state of matter created in these collisions exists for only 2x10 -23 s. So does the quark gluon plasma exist? No-one doubts that it did at one time, before the vacuum froze into its current state about 20 into the life of the universe, causing the nucleons to form as we know them today. The issue is whether we can recreate this early stage of the universe in laboratory experiments. And if we did

  16. Glacial melting in Himalaya

    Directory of Open Access Journals (Sweden)

    Kavita Tariyal

    2013-07-01

    Full Text Available Mountains are amongst the most flimsy environments on Earth. They are prosperous repositories of biodiversity, water and providers of ecosystem goods and services on which downstream communities, both regional and global, rely. The transport of atmospheric pollutants and climate-altering substances can significantly impact high mountain areas, which are generally considered “clean” regions. The snow glaciers of the Himalayas, considered the “third pole”, one of the largest stores of water on the planet and accelerated melting could have far-reaching effects, such as flooding in the short-term and water shortages in the long-term as the glaciers shrink. The data available on temperature in Himalayas indicate that warming during last 3-4 decades has been more than the global average over the last century. Some of the values indicate that the Himalayas are warming 5-6 times more than the global average. Mountain systems are seen globally as the prime sufferers from climate change. There is a severe gap in the knowledge of the short and long-term implications of the impact of climate change on water and hazards in the Himalayas, and their downstream river basins. Most studies have excluded the Himalayan region because of its extreme and complex topography and the lack of adequate rain gauge data. There is an urgent need to close the knowledge gap by establishing monitoring schemes for snow, ice and water; downscaling climate models; applying hydrological models to predict water availability; and developing basin wide scenarios, which also take water demand and socioeconomic development into account. Climate change induced hazards such as floods, landslides and droughts will impose considerable stresses on the livelihoods of mountain people and downstream populations. Enhancing resilience and promoting adaptation in mountain areas have thus become among the most important priorities of this decade. It is important to strengthen local

  17. Investigation of the stability of melt flow in gating systems

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat; Larsen, Per

    2011-01-01

    Melt flow in four different gating systems designed for production of brake discs was analysed experimentally and by numerical modelling. In the experiments moulds were fitted with glass fronts and melt flow was recorded on video. The video recordings were compared with modelling of melt flow...... in the gating systems. Particular emphasis was on analysing local pressure and formation of pressure waves in the gating system. It was possible to compare melt flow patterns in experiments directly to modelled flow patterns. Generally there was good agreement between flow patterns and filling times. However...... description of free liquid surfaces proved to be incorrect in the numerical model. Modelled pressure fields served to explain how specific parts of the gating systems cause instability and are a good tool to describe the quality of a gating system. The results shows clearly that sharp changes in the geometry...

  18. Using Flory-Huggins phase diagrams as a pre-formulation tool for the production of amorphous solid dispersions: a comparison between hot-melt extrusion and spray drying.

    Science.gov (United States)

    Tian, Yiwei; Caron, Vincent; Jones, David S; Healy, Anne-Marie; Andrews, Gavin P

    2014-02-01

    Amorphous drug forms provide a useful method of enhancing the dissolution performance of poorly water-soluble drugs; however, they are inherently unstable. In this article, we have used Flory-Huggins theory to predict drug solubility and miscibility in polymer candidates, and used this information to compare spray drying and melt extrusion as processes to manufacture solid dispersions. Solid dispersions were prepared using two different techniques (hot-melt extrusion and spray drying), and characterised using a combination of thermal (thermogravimetric analysis and differential scanning calorimetry), spectroscopic (Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction methods. Spray drying permitted generation of amorphous solid dispersions across a wider drug concentration than melt extrusion. Melt extrusion provided sufficient energy for more intimate mixing to be achieved between drug and polymer, which may improve physical stability. It was also confirmed that stronger drug-polymer interactions might be generated through melt extrusion. Remixing and dissolution of recrystallised felodipine into the polymeric matrices did occur during the modulated differential scanning calorimetry analysis, but the complementary information provided from FTIR confirms that all freshly prepared spray-dried samples were amorphous with the existence of amorphous drug domains within high drug-loaded samples. Using temperature-composition phase diagrams to probe the relevance of temperature and drug composition in specific polymer candidates facilitates polymer screening for the purpose of formulating solid dispersions. © 2013 Royal Pharmaceutical Society.

  19. Artificial magma program: Report on workshop held in Oak Ridge, Tennessee on March 29-30, 1994

    International Nuclear Information System (INIS)

    Naney, M.T.; Jacobs, G.K.

    1995-03-01

    A workshop was organized and conducted in Oak Ridge, Tennessee, on March 29 and 30, 1994, to evaluate the use of in situ vitrification (ISV) technology to produce large silicate melts that would serve as analogs for natural magmas for the study of magmatic properties and processes. ISV technology would permit experiments to test hypotheses or provide new data that cannot be tested or obtained through bench-top experimentation or the study of natural systems. The scale of ISV melts is intermediate between that of natural lava lakes and laboratory crucible experiments, with melt volumes from 15 to 300 m 3 easily obtained. This approach permits investigation of dynamic processes which operate on scales difficult to simulate through bench-top experimentation and that are not amenable to direct observation or control in natural systems (e.g., degassing, convection, and crystal settling). Several aspects of the ISV process make it uniquely applicable for the study of magma systems. The process produces open-quotes containerlessclose quotes silicate melts, which permits development of important analog components of natural magma systems including: partial melt zones, stopping, contact metamorphic haloes, and open-quotes hydrothermalclose quotes fluids. The lack of a melt open-quotes containerclose quotes also enables use of standard field-scale geophysical instrumentation for studying the seismic and electrical properties of the melt and host materials. In addition, volatile and particulate emissions from the melt can be sampled using methods that avoid reaction with, and contamination by, host rocks. The consensus of the group was that the use of melts generated by ISV technology provided unique opportunities to advance the understanding of magmas and magmatic processes and warranted development of a proposal

  20. Alveolar Ridge Carcinoma. Two Cases Report

    International Nuclear Information System (INIS)

    Pupo Triguero, Raul J; Vivar Bauza, Miriam; Alvarez Infante, Elisa

    2008-01-01

    Two cases with alveolar ridge carcinoma due to prosthetist traumatism are discussed in this paper, after 9 and 10 years of using dental prosthesis. Both patients began with disturbance in the alveolar ridge. The clinical examination and biopsy showed a well differenced carcinoma. The treatment was radical surgery and radiotherapy in the first patient, and conservative surgery with radiotherapy in the second case .The patients had xerostomia after radiotherapy and the woman had difficulties with mastication. The advantages and disadvantages of the treatment were discussed, focused on the prevention and treatment for oral

  1. ORLANDO - Oak Ridge Large Neutrino Detector

    International Nuclear Information System (INIS)

    Bugg, W.; Cohn, H.; Efremenko, Yu.; Fazely, A.; Gabriel, T.; Kamyshkov, Yu.; Plasil, F.; Svoboda, R.

    1999-01-01

    We discuss a proposal for construction of an Oak Ridge LArge Neutrino DetectOr (ORLANDO) to search for neutrino oscillations at the Spallation Neutron Source (SNS). A 4 MW SNS is proposed to be built at the Oak Ridge National Laboratory with the first stage to be operative around 2006. It will have two target stations, which makes it possible with a single detector to perform a neutrino oscillation search at two different distances. Initial plans for the placement of the detector and the discovery potential of such a detector are discussed

  2. Three-Dimensional Seismic Structure of the Mid-Atlantic Ridge: An Investigation of Tectonic, Magmatic, and Hydrothermal Processes in the Rainbow Area

    Science.gov (United States)

    Dunn, Robert A.; Arai, Ryuta; Eason, Deborah E.; Canales, J. Pablo; Sohn, Robert A.

    2017-12-01

    To test models of tectonic, magmatic, and hydrothermal processes along slow-spreading mid-ocean ridges, we analyzed seismic refraction data from the Mid-Atlantic Ridge INtegrated Experiments at Rainbow (MARINER) seismic and geophysical mapping experiment. Centered at the Rainbow area of the Mid-Atlantic Ridge (36°14'N), this study examines a section of ridge with volcanically active segments and a relatively amagmatic ridge offset that hosts the ultramafic Rainbow massif and its high-temperature hydrothermal vent field. Tomographic images of the crust and upper mantle show segment-scale variations in crustal structure, thickness, and the crust-mantle transition, which forms a vertical gradient rather than a sharp boundary. There is little definitive evidence for large regions of sustained high temperatures and melt in the lower crust or upper mantle along the ridge axes, suggesting that melts rising from the mantle intrude as small intermittent magma bodies at crustal and subcrustal levels. The images reveal large rotated crustal blocks, which extend to mantle depths in some places, corresponding to off-axis normal fault locations. Low velocities cap the Rainbow massif, suggesting an extensive near-surface alteration zone due to low-temperature fluid-rock reactions. Within the interior of the massif, seismic images suggest a mixture of peridotite and gabbroic intrusions, with little serpentinization. Here diffuse microearthquake activity indicates a brittle deformation regime supporting a broad network of cracks. Beneath the Rainbow hydrothermal vent field, fluid circulation is largely driven by the heat of small cooling melt bodies intruded into the base of the massif and channeled by the crack network and shallow faults.

  3. Additive Manufacturing Processes: Selective Laser Melting, Electron Beam Melting and Binder Jetting—Selection Guidelines

    Science.gov (United States)

    Konda Gokuldoss, Prashanth; Kolla, Sri; Eckert, Jürgen

    2017-01-01

    Additive manufacturing (AM), also known as 3D printing or rapid prototyping, is gaining increasing attention due to its ability to produce parts with added functionality and increased complexities in geometrical design, on top of the fact that it is theoretically possible to produce any shape without limitations. However, most of the research on additive manufacturing techniques are focused on the development of materials/process parameters/products design with different additive manufacturing processes such as selective laser melting, electron beam melting, or binder jetting. However, we do not have any guidelines that discuss the selection of the most suitable additive manufacturing process, depending on the material to be processed, the complexity of the parts to be produced, or the design considerations. Considering the very fact that no reports deal with this process selection, the present manuscript aims to discuss the different selection criteria that are to be considered, in order to select the best AM process (binder jetting/selective laser melting/electron beam melting) for fabricating a specific component with a defined set of material properties. PMID:28773031

  4. Additive Manufacturing Processes: Selective Laser Melting, Electron Beam Melting and Binder Jetting-Selection Guidelines.

    Science.gov (United States)

    Gokuldoss, Prashanth Konda; Kolla, Sri; Eckert, Jürgen

    2017-06-19

    Additive manufacturing (AM), also known as 3D printing or rapid prototyping, is gaining increasing attention due to its ability to produce parts with added functionality and increased complexities in geometrical design, on top of the fact that it is theoretically possible to produce any shape without limitations. However, most of the research on additive manufacturing techniques are focused on the development of materials/process parameters/products design with different additive manufacturing processes such as selective laser melting, electron beam melting, or binder jetting. However, we do not have any guidelines that discuss the selection of the most suitable additive manufacturing process, depending on the material to be processed, the complexity of the parts to be produced, or the design considerations. Considering the very fact that no reports deal with this process selection, the present manuscript aims to discuss the different selection criteria that are to be considered, in order to select the best AM process (binder jetting/selective laser melting/electron beam melting) for fabricating a specific component with a defined set of material properties.

  5. Normalization Ridge Regression in Practice I: Comparisons Between Ordinary Least Squares, Ridge Regression and Normalization Ridge Regression.

    Science.gov (United States)

    Bulcock, J. W.

    The problem of model estimation when the data are collinear was examined. Though the ridge regression (RR) outperforms ordinary least squares (OLS) regression in the presence of acute multicollinearity, it is not a problem free technique for reducing the variance of the estimates. It is a stochastic procedure when it should be nonstochastic and it…

  6. Methods for Melting Temperature Calculation

    Science.gov (United States)

    Hong, Qi-Jun

    Melting temperature calculation has important applications in the theoretical study of phase diagrams and computational materials screenings. In this thesis, we present two new methods, i.e., the improved Widom's particle insertion method and the small-cell coexistence method, which we developed in order to capture melting temperatures both accurately and quickly. We propose a scheme that drastically improves the efficiency of Widom's particle insertion method by efficiently sampling cavities while calculating the integrals providing the chemical potentials of a physical system. This idea enables us to calculate chemical potentials of liquids directly from first-principles without the help of any reference system, which is necessary in the commonly used thermodynamic integration method. As an example, we apply our scheme, combined with the density functional formalism, to the calculation of the chemical potential of liquid copper. The calculated chemical potential is further used to locate the melting temperature. The calculated results closely agree with experiments. We propose the small-cell coexistence method based on the statistical analysis of small-size coexistence MD simulations. It eliminates the risk of a metastable superheated solid in the fast-heating method, while also significantly reducing the computer cost relative to the traditional large-scale coexistence method. Using empirical potentials, we validate the method and systematically study the finite-size effect on the calculated melting points. The method converges to the exact result in the limit of a large system size. An accuracy within 100 K in melting temperature is usually achieved when the simulation contains more than 100 atoms. DFT examples of Tantalum, high-pressure Sodium, and ionic material NaCl are shown to demonstrate the accuracy and flexibility of the method in its practical applications. The method serves as a promising approach for large-scale automated material screening in which

  7. Wrinkle Ridges and Young Fresh Crater

    Science.gov (United States)

    2002-01-01

    (Released 10 May 2002) The Science Wrinkle ridges are a very common landform on Mars, Mercury, Venus, and the Moon. These ridges are linear to arcuate asymmetric topographic highs commonly found on smooth plains. The origin of wrinkle ridges is not certain and two leading hypotheses have been put forth by scientists over the past 40 years. The volcanic model calls for the extrusion of high viscosity lavas along linear conduits. This thick lava accumulated over these conduits and formed the ridges. The other model is tectonic and advocates that the ridges are formed by compressional faulting and folding. Today's THEMIS image is of the ridged plains of Lunae Planum located between Kasei Valles and Valles Marineris in the northern hemisphere of the planet. Wrinkle ridges are found mostly along the eastern side of the image. The broadest wrinkle ridges in this image are up to 2 km wide. A 3 km diameter young fresh crater is located near the bottom of the image. The crater's ejecta blanket is also clearly seen surrounding the sharp well-defined crater rim. These features are indicative of a very young crater that has not been subjected to erosional processes. The Story The great thing about the solar system is that planets are both alike and different. They're all foreign enough to be mysterious and intriguing, and yet familiar enough to be seen as planetary 'cousins.' By comparing them, we can learn a lot about how planets form and then evolve geologically over time. Crinkled over smooth plains, the long, wavy raised landforms seen here are called 'wrinkle ridges,' and they've been found on Mars, Mercury, Venus, and the Moon - that is, on rocky bodies that are a part of our inner solar system. We know from this observation that planets (and large-enough moons) follow similar processes. What we don't know for sure is HOW these processes work. Scientists have been trying to understand how wrinkle ridges form for 40 years, and they still haven't reached a conclusion. That

  8. Ridge regression estimator: combining unbiased and ordinary ridge regression methods of estimation

    Directory of Open Access Journals (Sweden)

    Sharad Damodar Gore

    2009-10-01

    Full Text Available Statistical literature has several methods for coping with multicollinearity. This paper introduces a new shrinkage estimator, called modified unbiased ridge (MUR. This estimator is obtained from unbiased ridge regression (URR in the same way that ordinary ridge regression (ORR is obtained from ordinary least squares (OLS. Properties of MUR are derived. Results on its matrix mean squared error (MMSE are obtained. MUR is compared with ORR and URR in terms of MMSE. These results are illustrated with an example based on data generated by Hoerl and Kennard (1975.

  9. Large fault fabric of the Ninetyeast Ridge implies near-spreading ridge formation

    Digital Repository Service at National Institute of Oceanography (India)

    Sager, W.W.; Paul, C.F.; Krishna, K.S.; Pringle, M.S.; Eisin, A.E.; Frey, F.A.; Rao, D.G.; Levchenko, O.V.

    of the high ridge. At 26°S, prominent NE-SW 97 oriented lineations extend southwest from the ridge. Some appear to connect with N-S fracture 98 zone troughs east of NER, implying that the NE-SW features are fracture zone scars formed after 99 the change... to the 105 ridge (Fig. 3). This is especially true for NER south of ~4°S. Where KNOX06RR crossed a 106 gravity lineation, negative gradient features correspond to troughs whereas positive gradient 107 features result from igneous basement highs (Fig. 3...

  10. Treatability studies of actual listed waste sludges from the Oak Ridge Reservation (ORR)

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Peeler, D.K.; Gilliam, T.M.; Bleier, A.; Spence, R.D.

    1996-01-01

    Oak Ridge National Laboratory (ORNL) and Savannah River Technology Center (SRTC) are investigating vitrification for various low-level and mixed wastes on the Oak Ridge Reservation (ORR). Treatability studies have included surrogate waste formulations at the laboratory-, pilot-, and field-scales and actual waste testing at the laboratory- and pilot-scales. The initial waste to be processing through SRTC's Transportable Vitrification System (TVS) is the K-1407-B and K-1407-C (B/C) Pond sludge waste which is a RCRA F-listed waste. The B/C ponds at the ORR K-25 site were used as holding and settling ponds for various waste water treatment streams. Laboratory-, pilot-, and field- scale ''proof-of-principle'' demonstrations are providing needed operating parameters for the planned field-scale demonstration with actual B/C Pond sludge waste at ORR. This report discusses the applied systems approach to optimize glass compositions for this particular waste stream through laboratory-, pilot-, and field-scale studies with surrogate and actual B/C waste. These glass compositions will maximize glass durability and waste loading while optimizing melt properties which affect melter operation, such as melt viscosity and melter refractory corrosion. Maximum waste loadings minimize storage volume of the final waste form translating into considerable cost savings

  11. Melting of superheated molecular crystals

    Science.gov (United States)

    Cubeta, Ulyana; Bhattacharya, Deepanjan; Sadtchenko, Vlad

    2017-07-01

    Melting dynamics of micrometer scale, polycrystalline samples of isobutane, dimethyl ether, methyl benzene, and 2-propanol were investigated by fast scanning calorimetry. When films are superheated with rates in excess of 105 K s-1, the melting process follows zero-order, Arrhenius-like kinetics until approximately half of the sample has transformed. Such kinetics strongly imply that melting progresses into the bulk via a rapidly moving solid-liquid interface that is likely to originate at the sample's surface. Remarkably, the apparent activation energies for the phase transformation are large; all exceed the enthalpy of vaporization of each compound and some exceed it by an order of magnitude. In fact, we find that the crystalline melting kinetics are comparable to the kinetics of dielectric α-relaxation in deeply supercooled liquids. Based on these observations, we conclude that the rate of non-isothermal melting for superheated, low-molecular-weight crystals is limited by constituent diffusion into an abnormally dense, glass-like, non-crystalline phase.

  12. Improved capacitive melting curve measurements

    International Nuclear Information System (INIS)

    Sebedash, Alexander; Tuoriniemi, Juha; Pentti, Elias; Salmela, Anssi

    2009-01-01

    Sensitivity of the capacitive method for determining the melting pressure of helium can be enhanced by loading the empty side of the capacitor with helium at a pressure nearly equal to that desired to be measured and by using a relatively thin and flexible membrane in between. This way one can achieve a nanobar resolution at the level of 30 bar, which is two orders of magnitude better than that of the best gauges with vacuum reference. This extends the applicability of melting curve thermometry to lower temperatures and would allow detecting tiny anomalies in the melting pressure, which must be associated with any phenomena contributing to the entropy of the liquid or solid phases. We demonstrated this principle in measurements of the crystallization pressure of isotopic helium mixtures at millikelvin temperatures by using partly solid pure 4 He as the reference substance providing the best possible universal reference pressure. The achieved sensitivity was good enough for melting curve thermometry on mixtures down to 100 μK. Similar system can be used on pure isotopes by virtue of a blocked capillary giving a stable reference condition with liquid slightly below the melting pressure in the reference volume. This was tested with pure 4 He at temperatures 0.08-0.3 K. To avoid spurious heating effects, one must carefully choose and arrange any dielectric materials close to the active capacitor. We observed some 100 pW loading at moderate excitation voltages.

  13. Automatic Control of Silicon Melt Level

    Science.gov (United States)

    Duncan, C. S.; Stickel, W. B.

    1982-01-01

    A new circuit, when combined with melt-replenishment system and melt level sensor, offers continuous closed-loop automatic control of melt-level during web growth. Installed on silicon-web furnace, circuit controls melt-level to within 0.1 mm for as long as 8 hours. Circuit affords greater area growth rate and higher web quality, automatic melt-level control also allows semiautomatic growth of web over long periods which can greatly reduce costs.

  14. Internal doses in Oak Ridge. The Internet beams

    International Nuclear Information System (INIS)

    Passchier, W.F.

    1997-01-01

    A brief overview is given of the information, presented by the Radiation Internal Dose Information Center (RIDIC) of the Oak Ridge Associated Universities in Oak Ridge, TN, USA, via Internet (www.orau.gov/ehsd/ridic.htm)

  15. Efficiency of local surface plasmon polariton excitation on ridges

    DEFF Research Database (Denmark)

    Radko, Ilya; Bozhevolnyi, Sergey I.; Boltasseva, Alexandra

    2008-01-01

    We investigate experimentally and numerically the efficiency of surface plasmon polariton excitation by a focused laser beam using gold ridges. The dependence of the efficiency on geometrical parameters of ridges and wavelength dependence are examined. The experimental measurements accomplished...

  16. DEVELOPMENT OF A RIDGE PROFILE WEEDER

    African Journals Online (AJOL)

    ES Obe

    1980-03-01

    driven rotating horizontal short shaft which is connected by universal joints to two gangs of rotary hoe weeders. With the short shaft nearly at the bottom of a furrow between two ridges, the gangs of weeders lie on the sides of ...

  17. Oak Ridge Reservation Waste Management Plan

    International Nuclear Information System (INIS)

    Turner, J.W.

    1995-02-01

    This report presents the waste management plan for the Oak Ridge Reservation facilities. The primary purpose is to convey what facilities are being used to manage wastes, what forces are acting to change current waste management systems, and what plans are in store for the coming fiscal year

  18. Remedial Investigation Work Plan for Chestnut Ridge Operable Unit 1 (Chestnut Ridge Security Pits) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    This Remedial Investigation (RI) Work Plan specifically addresses Chestnut Ridge Operable Unit 1, (OU1) which consists of the Chestnut Ridge Security Pits (CRSP). The CRSP are located {approximately}800 ft southeast of the central portion of the Y-12 Plant atop Chestnut Ridge, which is bounded to the northwest by Bear Creek Valley and to the southeast by Bethel Valley. Operated from 1973 to 1988, the CRSP consisted of a series of trenches used for the disposal of classified hazardous and nonhazardous waste materials. Disposal of hazardous waste materials was discontinued in December 1984, while nonhazardous waste disposal ended on November 8, 1988. An RI is being conducted at this site in response to CERCLA regulations. The overall objectives of the RI are to collect data necessary to evaluate the nature and extent of contaminants of concern (COC), support an ecological risk assessment (ERA) and a human health risk assessment (HHRA), support the evaluation of remedial alternatives, and ultimately develop a Record of Decision for the site. The purpose of this Work Plan is to outline RI activities necessary to define the nature and extent of suspected contaminants at Chestnut Ridge OU1. Potential migration pathways also will be investigated. Data collected during the RI will be used to evaluate the overall risk posed to human health and the environment by OU1.

  19. Alveolar ridge augmentation by osteoinduction in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Bang, G; Haanaes, H R

    1990-01-01

    The purpose of this study was to evaluate bone substitutes for alveolar ridge augmentation by osteoinduction. Allogenic, demineralized, and lyophilized dentin and bone was tested for osteoinductive properties in order to establish an experimental model for further studies. Implantations were perf...

  20. Oak Ridge Reservation Waste Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Turner, J.W. [ed.

    1995-02-01

    This report presents the waste management plan for the Oak Ridge Reservation facilities. The primary purpose is to convey what facilities are being used to manage wastes, what forces are acting to change current waste management systems, and what plans are in store for the coming fiscal year.

  1. 25 MV tandem accelerator at Oak Ridge

    International Nuclear Information System (INIS)

    Jones, C.M.

    1980-01-01

    A new heavy-ion accelerator facility is under construction at the Oak Ridge National Laboratory. A brief description of the scope and status of this project is presented with emphasis on the first operational experience with the 25 MV tandem accelerator

  2. Remedial Investigation Work Plan for Chestnut Ridge Operable Unit 1 (Chestnut Ridge Security Pits) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1993-09-01

    This Remedial Investigation (RI) Work Plan specifically addresses Chestnut Ridge Operable Unit 1, (OU1) which consists of the Chestnut Ridge Security Pits (CRSP). The CRSP are located ∼800 ft southeast of the central portion of the Y-12 Plant atop Chestnut Ridge, which is bounded to the northwest by Bear Creek Valley and to the southeast by Bethel Valley. Operated from 1973 to 1988, the CRSP consisted of a series of trenches used for the disposal of classified hazardous and nonhazardous waste materials. Disposal of hazardous waste materials was discontinued in December 1984, while nonhazardous waste disposal ended on November 8, 1988. An RI is being conducted at this site in response to CERCLA regulations. The overall objectives of the RI are to collect data necessary to evaluate the nature and extent of contaminants of concern (COC), support an ecological risk assessment (ERA) and a human health risk assessment (HHRA), support the evaluation of remedial alternatives, and ultimately develop a Record of Decision for the site. The purpose of this Work Plan is to outline RI activities necessary to define the nature and extent of suspected contaminants at Chestnut Ridge OU1. Potential migration pathways also will be investigated. Data collected during the RI will be used to evaluate the overall risk posed to human health and the environment by OU1

  3. Petrography of basalts from the Carlsberg ridge

    Digital Repository Service at National Institute of Oceanography (India)

    Banerjee, R.; Iyer, S.D.

    Petrographic characteristics of basalts collected from a segment of the Carlsberg Ridge (lat. 3 degrees 35'N to 3 degrees 41'N; long. 64 degrees 05'E to 64 degrees 09'E) show typical pillow lava zonations with variable concentrations of plagioclase...

  4. Seismic Structure of the Shallow Mantle Beneath the Endeavor Segment of the Juan de Fuca Ridge

    Science.gov (United States)

    VanderBeek, B. P.; Toomey, D. R.; Hooft, E. E.; Wilcock, W. S.; Weekly, R. T.; Soule, D. C.

    2013-12-01

    We present tomographic images of the seismic structure of the shallow mantle beneath the intermediate-spreading Endeavor segment of the Juan de Fuca ridge. Our results provide insight into the relationship between magma supply from the mantle and overlying ridge crest processes. We use seismic energy refracted below the Moho (Pn), as recorded by the Endeavor tomography (ETOMO) experiment, to image the anisotropic and isotropic P wave velocity structure. The ETOMO experiment was an active source seismic study conducted in August 2009 as part of the RIDGE2000 science program. The experimental area extends 100 km along- and 60 km across-axis and encompasses active hydrothermal vent fields near the segment center, the eastern end of the Heck seamount chain, and two overlapping spreading centers (OSCs) at either end of the segment. Previous tomographic analyses of seismic arrivals refracted through the crust (Pg), and reflected off the Moho (PmP), constrain a three-dimensional starting model of crustal velocity and thickness. These Pg and PmP arrivals are incorporated in our inversion of Pn travel-time data to further constrain the isotropic and anisotropic mantle velocity structure. Preliminary results reveal three distinct mantle low-velocity zones, inferred as regions of mantle melt delivery to the base of the crust, that are located: (i) off-axis near the segment center, (ii) beneath the Endeavor-West Valley OSC, and (iii) beneath the Cobb OSC near Split Seamount. The mantle anomalies are located at intervals of ~30 to 40 km along-axis and the low velocity anomalies beneath the OSCs are comparable in magnitude to the one located near the segment center. The direction of shallow mantle flow is inferred from azimuthal variations in Pn travel-time residuals relative to a homogeneous isotropic mantle. Continuing analysis will focus on constraining spatial variations in the orientation of azimuthal anisotropy. On the basis of our results, we will discuss the transport of

  5. 3001 canal radiological characterization and waste removal report, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Ritchie, M.G.

    1996-12-01

    An underground steel reinforced concrete transfer and storage canal was built in 1943 and operated as an integral part of the Oak Ridge Graphite Reactor Building (3001) until 1963 when the reactor was shutdown. During operation, the canal was used for under water transfer of irradiated materials and other metals from the reactor in Building 3001 to the Building 3019 hot cell for further processing. After shutdown of the reactor, the canal was used for storage of irradiated materials and fission products until 1990 when the larger materials were removed and stored in the Department of Energy (DOE) approved solid waste management storage facilities. At that time it was discovered that a considerable amount of sludge had accumulated over the intervening years and subsequent analysis showed that the sludge contained Resource Conservation and Recovery Act (RCRA) materials that violated quantities allowed by the RCRA regulations. It was also recognized in 1990 that the canal was losing water to evaporation and the ground at the rate of approximately 400 gallons per day. To maintain water quality; i.e., radionuclide content at or near DOE derived concentration guidelines (DCG), the water in the canal is constantly demineralized using a demineralizer in the Building 3001 and demineralized make up water is supplied from the Building 3004 demineralizer. This report summarizes the 301 Canal Cleanup Task and the solid waste removed from the 3001 Canal in 1996

  6. The Northern Central Indian Ridge: Geology and tectonics of fracture zones-dominated spreading ridge segments

    Digital Repository Service at National Institute of Oceanography (India)

    Drolia, R.K.; Iyer, S.D.; Chakraborty, B.; Kodagali, V.N.; Ray, Dwijesh; Misra, S.; Andrade, R.; Sarma, K.V.L.N.S.; Rajasekhar, R.P.; Mukhopadhyay, R.

    Multi-beam and single-beam bathymetric, gravity and magnetic data, across seven ridge segments (length varying between 37 and 84 km), offset by six transform discontinuities (ranging in dislocation length between 48 and 344 km) of the Northern...

  7. Origins and Driving Mechanisms for Shallow Methane Accumulations on the Svyatogor Ridge, Fram Strait

    Science.gov (United States)

    Waghorn, K. A.; Bunz, S.; Plaza-Faverola, A. A.; Westvig, I. M.; Johnson, J. E.

    2015-12-01

    The Svyatogor Ridge, located west of the Knipovich Spreading Ridge (KR) and south of the Molloy Transform Fault (MTF), is hypothesized to have once been the south tip of Vestnesa Ridge; a large sediment drift that was offset during the last 2 Ma along the MTF. The sedimentary cover across Svyatogor Ridge is limited, compared to Vestnesa Ridge, and basement outcrops are identified ~850 mbsf on the apex of the ridge. Despite the limited sedimentation, and its unique location at the intersection between the KR and MTF, Svyatogor Ridge has evidence of shallow gas accumulations; a strong BSR indicating a gas hydrate and underlying free gas system, and fluid flow pathways to the seafloor culminating in pockmarks. Using a high-resolution P-Cable 3D seismic survey, 2D seismic, and multibeam bathymetry data, we investigate how tectonic and sedimentary regimes have influenced the formation of a well-developed gas hydrate system. Sedimentation related with the Vestnesa drift on Svyatogor Ridge is interpreted to have begun ~2-3 Ma. The young age of the underlying oceanic crust, and subsequent synrift sediments below drift strata, suggests gas production from early Miocene aged hydrocarbon source identified in ODP Site 909 to the west, is unlikely in this region. Additionally, given the ultra-slow, magma limited spreading regime of the KR, we do not expect significant thermogenic methane generation from shallow magmatic sources. Therefore, in addition to some microbial gas production, Johnson et al. (2015) hypothesize a contribution from an abiotic source may explain the well-developed gas hydrate system. Large-scale basement faults identified in the seismic data are interpreted as detachment faults, which have exhumed relatively young ultramafic rocks. These detachment faults act as conduits for fluid flow, allowing circulation of seawater to drive serpentinization and subsequently act as pathways for fluids and abiotic methane to reach the shallow subsurface. This work aims

  8. Ferric iron partitioning between pyroxene and melt during partial melting of the Earth's upper mantle

    Science.gov (United States)

    Rudra, A.; Hirschmann, M. M.

    2017-12-01

    The oxidation state of the Earth's mantle influences melt production, volatile behavior, partitioning of key trace elements and possible saturation of alloy at depth. Average Fe3+/FeT ratios in MORBs indicate oxygen fugacitiy of the source regions is close to QFM, in contrast to a 3 log unit variation of fO2 recorded by abyssal peridotites. Quantification of the relationship between basalt and source Fe3+/FeT, oxygen fugacity, and melting requires constraints on Fe3+ partitioning between melt and mantle minerals and in particular the principal Fe3+ host, pyroxene. McCanta et al. (2004) investigated valence dependent partitioning of Fe between Martian ferroan pigeonites and melt, but behavior in terrestrial pyroxene compositions relevant to MORB petrogenesis has not been investigated. We are conducting 1 atm controlled fO2 experiments over 4 log unit variation of fO2 between ΔQFM = 2.5 to -1.5 to grow pyroxenes of variable tetrahedral and octahedral cationic population from andesitic melts of varying Mg#, alumina and alkali content. Dynamic crystallization technique facilitates growth of pyroxene crystals (100-200 um) that EPMA analyses show to be compositionally homogeneous and in equilibrium with the melt. Fe3+/FeT ratio of the synthetic pyroxenes have been analyzed by XAFS spectroscopy at the APS (GSECARS) synchrotron. To quantify the x-ray anisotropy in pyroxenes, we collected Fe K-edge XAFS spectra of oriented natural single crystals for a wide range compositions whose Fe3+/FeT ratios we determined by Mossbauer spectroscopy. We have collected both XANES and EXAFS spectral regions spanning from 7020-7220 eV to explore predictive capabilities of different spectral regions about ferric iron concentration and site occupancy. Our results will document the Fe3+ compatibility in pyroxenes of different compositions under a variety of fO2 conditions, which in turn will better constrain the interrelationship between mantle redox and melting.

  9. Magnetic susceptibility of semiconductor melts

    International Nuclear Information System (INIS)

    Kutvitskij, V.A.; Shurygin, P.M.

    1975-01-01

    The temperature dependences chi of various alloys confirm the existence of cluster formations in molten semiconductors, the stability of these formations in melts being considerably affected by the anion nature. The concentrational dependences of the magnetic susceptibility for all the investigated systems exhibit the diamagnetism maxima corresponding to the compound compositions. Heating the melt causes ''smearing'' the maxima, which is related with the cluster structure dissociation. The existence of the maxima concentrational dependence chi corresponding to BiTe and BiSe is found in the isotherms. The non-linear dependence of chi on the composition shows the absence of a single-valued relation between the phase diagram and the chi-diagram for melts

  10. Design assessment for the Bethel Valley FFA Upgrades at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1995-09-01

    This report describes the proposed upgrades to Building 3025 and the Evaporator Area at Oak Ridge National Laboratory. Design assessments, specifications and drawings are provided. Building 3025 is a general purpose research facility utilized by the Materials and Ceramics Division to conduct research on irradiated materials. The Evaporator Area, building 2531, serves as the collection point for all low-level liquid wastes generated at the Oak Ridge National Laboratory

  11. Deformation associated with the denudation of mantle-derived rocks at the Mid-Atlantic Ridge 13°-15°N: The role of magmatic injections and hydrothermal alteration

    Science.gov (United States)

    Picazo, Suzanne; Cannat, Mathilde; Delacour, AdéLie; EscartíN, Javier; RouméJon, StéPhane; Silantyev, Sergei

    2012-09-01

    Outcrops of deeply derived ultramafic rocks and gabbros are widespread along slow spreading ridges where they are exposed in the footwall of detachment faults. We report on the microstructural and petrological characteristics of a large number of samples from ultramafic exposures in the walls of the Mid-Atlantic Ridge (MAR) axial valley at three distinct locations at lat. 13°N and 14°45'N. One of these locations corresponds to the footwall beneath a corrugated paleo-fault surface. Bearing in mind that dredging and ROV sampling may not preserve the most fragile lithologies (fault gouges), this study allows us to document a sequence of deformation, and the magmatic and hydrothermal history recorded in the footwall within a few hundred meters of the axial detachment fault. At the three sampled locations, we find that tremolitic amphiboles have localized deformation in the ultramafic rocks prior to the onset of serpentinization. We interpret these tremolites as hydrothermal alteration products after evolved gabbroic rocks intruded into the peridotites. We also document two types of brittle deformation in the ultramafic rocks, which we infer could produce the sustained low magnitude seismicity recorded at ridge axis detachment faults. The first type of brittle deformation affects fresh peridotite and is associated with the injection of the evolved gabbroic melts, and the second type affects serpentinized peridotites and is associated with the injection of Si-rich hydrothermal fluids that promote talc crystallization, leading to strain localization in thin talc shear zones. We also observed chlorite + serpentine shear zones but did not identify samples with serpentine-only shear zones. Although the proportion of magmatic injections in the ultramafic rocks is variable, these characteristics are found at each investigated location and are therefore proposed as fundamental components of the deformation in the footwall of the detachment faults associated with denudation of

  12. Oak Ridge Reservation annual site environmental report for 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    The US Department of Energy currently oversees activities on the Oak Ridge Reservation (ORR), a government-owned, contractor-operated facility. Three sites compose the reservation: the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory, and East Tennessee Technology Park (formerly the K-25 Site). The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced the materials for the first atomic bombs. The reservation`s role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the US. Both the work carried out for the war effort and subsequent research, development, and production activities have produced (and continue to produce) radiological and hazardous wastes. This document contains a summary of environmental monitoring activities on the ORR and its surroundings. Environmental monitoring on the ORR consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring involves the collection and analysis of samples or measurements of liquid and gaseous effluents prior to release into the environment; these measurements allow the quantification and official reporting of contaminants, assessment of radiation exposures to the public, and demonstration of compliance with applicable standards and permit requirements. Environmental surveillance consists of the collection and analysis of environmental samples from the site and its environs; this provides direct measurement of contaminants in air, water, groundwater, soil, foods, biota, and other media subsequent to effluent release into the environment. Environmental surveillance data verify ORR`s compliance status and, combined with data from effluent monitoring, allow the determination of chemical and radiation dose/exposure assessment of ORR operations and effects, if any, on the local environment.

  13. Oak Ridge Reservation annual site environmental report for 1996

    International Nuclear Information System (INIS)

    1997-10-01

    The US Department of Energy currently oversees activities on the Oak Ridge Reservation (ORR), a government-owned, contractor-operated facility. Three sites compose the reservation: the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory, and East Tennessee Technology Park (formerly the K-25 Site). The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced the materials for the first atomic bombs. The reservation's role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the US. Both the work carried out for the war effort and subsequent research, development, and production activities have produced (and continue to produce) radiological and hazardous wastes. This document contains a summary of environmental monitoring activities on the ORR and its surroundings. Environmental monitoring on the ORR consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring involves the collection and analysis of samples or measurements of liquid and gaseous effluents prior to release into the environment; these measurements allow the quantification and official reporting of contaminants, assessment of radiation exposures to the public, and demonstration of compliance with applicable standards and permit requirements. Environmental surveillance consists of the collection and analysis of environmental samples from the site and its environs; this provides direct measurement of contaminants in air, water, groundwater, soil, foods, biota, and other media subsequent to effluent release into the environment. Environmental surveillance data verify ORR's compliance status and, combined with data from effluent monitoring, allow the determination of chemical and radiation dose/exposure assessment of ORR operations and effects, if any, on the local environment

  14. Some improved classification-based ridge parameter of Hoerl and ...

    African Journals Online (AJOL)

    Some improved classification-based ridge parameter of Hoerl and Kennard estimation techniques. ... This assumption is often violated and Ridge Regression estimator introduced by [2]has been identified to be more efficient than ordinary least square (OLS) in handling it. However, it requires a ridge parameter, K, of which ...

  15. Does the lateral intercondylar ridge disappear in ACL deficient patients?

    NARCIS (Netherlands)

    van Eck, C.F.; Martins, C.A.Q.; Vyas, S.M.; Celentano, U.; van Dijk, C.N.; Fu, F.H.

    2010-01-01

    The aim of this study was to determine whether there is a difference in the presence of the lateral intercondylar ridge and the lateral bifurcate ridge between patients with sub-acute and chronic ACL injuries. We hypothesized that the ridges would be present less often with chronic ACL deficiency.

  16. Management initiatives to waste management decisions and environmental compliance in Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.G.

    1988-01-01

    Martin Marietta Energy Systems, Inc. (MMES) has been the operating contractor for the nuclear production and research facilities at Oak Ridge, Tennessee and Paducah, Kentucky for about four and one-half years. Environmental compliance, regulatory interaction, and public confidence have been very significant issues during this time. This presentation will review the environmental situation in Oak Ridge in 1984 and will discuss management initiatives and experience in the development and implementation of effective environmental and waste management and health and safety programs committed to the protection of the environment, our workers and the public with an overall goal of full compliance with all current and anticipated regulations.

  17. Quality assurance consideration for cement-based grout technology programs at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    McDaniel, E.W.; Tallent, O.K.; Sams, T.L.; Delzer, D.B.

    1987-01-01

    Oak Ridge National Laboratory has developed and is continuing to refine a method of immobilizing low-level radioactive liquid wastes by mixing them with cementitious dry-solid blends. A quality assurance program is vital to the project because Nuclear Regulatory Commission (NRC), Environmental Protection Agency (EPA) and state environmental regulations must be demonstrably met (the work must be defensible in a court of law). The end result of quality assurance (QA) is, by definition, a product of demonstrable quality. In the laboratory, this entails traceability, repeatability, and credibility. This paper describes the application of QA in grout technology development at Oak Ridge National Laboratory

  18. Management initiatives to waste management decisions and environmental compliance in Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Jones, C.G.

    1988-01-01

    Martin Marietta Energy Systems, Inc. (MMES) has been the operating contractor for the nuclear production and research facilities at Oak Ridge, Tennessee and Paducah, Kentucky for about four and one-half years. Environmental compliance, regulatory interaction, and public confidence have been very significant issues during this time. This presentation will review the environmental situation in Oak Ridge in 1984 and will discuss management initiatives and experience in the development and implementation of effective environmental and waste management and health and safety programs committed to the protection of the environment, our workers and the public with an overall goal of full compliance with all current and anticipated regulations

  19. A study on the particle melting by plasma spraying

    International Nuclear Information System (INIS)

    Jung, In Ha; Ji, C. G.; Bae, S. O.; Yoon, J. H.; Kwon, H. I.

    2001-12-01

    As a preliminary study for fabricating a thick and dense free standing type deposit, powder melting studies were carried out. Various morphologies and sizes of powder having the same chemical compositions were applied in particle melting experiments with varying systematic parameters. Through the study of powder melting by inductively coupled plasma, we can conclude as followings: Argon-hydrogen plasma gas with a higher plasma power gave good quality of splats and shown a higher density with a higher build-up rate. Reproducibility of the experiments appeared in the range of 99%. Degree of particle melting and its density just before impinging played a predominant role in the density of a deposit. Chamber pressure has an effect on degree of deformation of the splats, i.e. on the particle momentum. Completely melted particle showed a high deformation appearance. Build-up rate had a relation with a fraction of the fully melted particle, and this also closely associates with productivity and economical efficiency. For increasing the fraction of the fully melted particle, either increasing the power or limiting the particle size was recommended. Mean pore size and its distribution of a deposit seemed to have a relation with a viscosity of the melted powder, i.e. particle temperature, and also with a chamber pressure and spraying distances. Particle temperature may be governed by a plasma power, plasma gas property, probe position, and spraying distance in the present experimental range. Some results might be appeared with mutual interactions of the effects, for example, particle residence time and momentum with chamber pressure, particle temperature with chamber pressure, spraying distance and its size

  20. A study on the particle melting by plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Jung, In Ha; Ji, C. G.; Bae, S. O.; Yoon, J. H.; Kwon, H. I

    2001-12-01

    As a preliminary study for fabricating a thick and dense free standing type deposit, powder melting studies were carried out. Various morphologies and sizes of powder having the same chemical compositions were applied in particle melting experiments with varying systematic parameters. Through the study of powder melting by inductively coupled plasma, we can conclude as followings: Argon-hydrogen plasma gas with a higher plasma power gave good quality of splats and shown a higher density with a higher build-up rate. Reproducibility of the experiments appeared in the range of 99%. Degree of particle melting and its density just before impinging played a predominant role in the density of a deposit. Chamber pressure has an effect on degree of deformation of the splats, i.e. on the particle momentum. Completely melted particle showed a high deformation appearance. Build-up rate had a relation with a fraction of the fully melted particle, and this also closely associates with productivity and economical efficiency. For increasing the fraction of the fully melted particle, either increasing the power or limiting the particle size was recommended. Mean pore size and its distribution of a deposit seemed to have a relation with a viscosity of the melted powder, i.e. particle temperature, and also with a chamber pressure and spraying distances. Particle temperature may be governed by a plasma power, plasma gas property, probe position, and spraying distance in the present experimental range. Some results might be appeared with mutual interactions of the effects, for example, particle residence time and momentum with chamber pressure, particle temperature with chamber pressure, spraying distance and its size.

  1. Thickness of Knox Group overburden on Central Chestnut Ridge, Oak Ridge Reservation

    International Nuclear Information System (INIS)

    Staub, W.P.; Hopkins, R.A.

    1984-05-01

    The thickness of residual soil overlying the Knox Group along Central Chestnut Ridge was estimated by a conventional seismic refraction survey. The purpose of this survey was to identify sites on the Department of Energy's Oak Ridge Reservation where ample overburden exists above the water table for the shallow land burial of low-level radioactive waste. The results of the survey suggest that the upper slopes of the higher ridges in the area have a minimum of 16 to 26 m (52 to 85 ft) of overburden and that the crests of these ridges may have more than 30 m (100 ft). Therefore, it is unlikely that sound bedrock would be encountered during trench excavation [maximum of 10 m (32 ft)] along Central Chestnut Ridge. Also, the relatively low seismic wave velocities measured in the overburden suggest that the water table is generally deep. On the basis of these preliminary results, Central Chestnut Ridge appears to be suitable for further site characterization for the shallow land burial of low-level radioactive waste. 3 references, 5 figures, 1 table

  2. Radiogenic isotopes in enriched mid-ocean ridge basalts from Explorer Ridge, northeast Pacific Ocean

    Science.gov (United States)

    Cousens, Brian; Weis, Dominique; Constantin, Marc; Scott, Steve

    2017-09-01

    Extreme gradients in topography related to variations in magma supply are observed on the Southern Explorer Ridge (SER), part of the northern Juan de Fuca ridge system. We report radiogenic isotope (Pb, Sr, Nd, Hf) and geochemical data for twenty-four basalt whole-rock and glass samples collected from the length of the SER and from Explorer Deep, a rift to the north of the SER. Lavas from the SER form a north-south geochemical gradient, dominated by E-MORB at the northern axial high, and range from T-MORB to N-MORB towards the southern deepest part of the ridge. Linear relationships between incompatible element ratios and isotopic ratios in MORB along the ridge are consistent with mixing of magmas beneath the ridge to generate the geographic gradient from E- to N-MORB. The E-MORB have high Sr and Pb, and low Nd and Hf isotopic ratios, typical of enriched mantle that includes a FOZO or HIMU isotopic component. The West Valley and Endeavour segments of the northern Juan de Fuca ridge also include this isotopic component, but the proportion of the FOZO or HIMU component is more extreme in the SER basalts. The FOZO or HIMU component may be garnet-bearing peridotite, or a garnet pyroxenite embedded in peridotite. Recycled garnet pyroxenite better explains the very shallow SER axial high, high Nb/La and La/Sm, and the ;enriched; isotopic compositions.

  3. On the rapid melt quenching

    International Nuclear Information System (INIS)

    Usatyuk, I.I.; Novokhatskij, I.A.; Kaverin, Yu.F.

    1994-01-01

    Specific features of instrumentation of traditionally employed method of melt spinning (rapid quenching), its disadvantages being discussed, were analyzed. The necessity of the method upgrading as applied to the problems of studying fine structure of molten metals and glasses was substantiated. The principle flowsheet of experimental facility for extremely rapid quenching of the melts of metals is described, specificity of its original functional units being considered. The sequence and character of all the principal stages of the method developed were discussed. 18 refs.; 3 figs

  4. High Resolution Melting Analysis for fast and cheap polymorphism screening of marine populations

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Anne-Leila Meistertzheim, Isabelle Calves, Sébastien Artigaud, Carolyn S. Friedman, Christine Paillard, Jean Laroche & Claude Ferec ### Abstract This protocol permits the mutation scanning of PCR products by high-resolution DNA melting analysis requiring the inclusion of a saturating intercalating dye in the PCR mix without labelled probe. During a scanning process, fluorescent melting curves of PCR amplicons are analyzed. Mutations modifying melting curve shapes, are allowed...

  5. Oak Ridge Reservation annual site environmental report for 1997: Color your tomorrow

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, L.V. [and others

    1998-10-01

    The U.S. Department of Energy currently oversees activities on the Oak Ridge Reservation (ORR), a government-owned, contractor-operated facility. The reservation contains three major operating sites: the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory, and East Tennessee Technology Park (formerly the K-25 Site). The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced the materials for the first atomic bombs. The reservation's role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the United States. Both the work carried out for the war effort and subsequent research, development, and production activities have involved (and continue to involve) radiological and hazardous materials.

  6. Oak Ridge Reservation annual site environmental report for 1997: Color your tomorrow

    International Nuclear Information System (INIS)

    Hamilton, L.V.

    1998-01-01

    The U.S. Department of Energy currently oversees activities on the Oak Ridge Reservation (ORR), a government-owned, contractor-operated facility. The reservation contains three major operating sites: the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory, and East Tennessee Technology Park (formerly the K-25 Site). The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced the materials for the first atomic bombs. The reservation's role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the United States. Both the work carried out for the war effort and subsequent research, development, and production activities have involved (and continue to involve) radiological and hazardous materials

  7. Effects of ridge tillage on photosynthesis and root characters of rice

    Directory of Open Access Journals (Sweden)

    Yao Yuan-zhi

    2015-03-01

    Full Text Available Rice (Oryza sativa L. is an important crop and breeding has not been able to improve yield. Root characteristics of hybrid rice 'Zhuliangyou 02' under conventional tillage and ridge tillage were studied in a Calcisols in Huaihua, China, from 2011 to 2013 to find better tillage methods to resolve massive water consumption, improve yield, and enhance productivity of agricultural labor for rice cultivation. Results showed ridge tillage increased photosynthetic parameters such as photosynthetic rate (P N, stomatal conductance (g s, and water use efficiency (WUE. It also significantly enhanced rice root number, root activity, and antioxidant enzyme activities; it also increased effective panicle number and actual yield by 22.12% and 15.18%, respectively, and enhanced aerenchymae during the early growth stage. Overall, ridge tillage could promote hybrid rice yields by enhancing root absorption, gas exchange, and reducing water consumption. It could be widely used in rice cultivation.

  8. How Greenland melts

    Directory of Open Access Journals (Sweden)

    van den Broeke M.R.

    2010-12-01

    Full Text Available Satellite altimetry and gravimetry show that the Greenland ice sheet has been losing volume and mass since the beginning of this century. However, from these short time series of direct measurements we cannot infer what the causes of the mass loss are, i.e. ice dynamics or surface processes, or that maybe the ice sheet returns to normal after a period of volume increase and mass gain. By modelling and observing the individual components of the ice sheet mass balance, i.e. snowfall, meltwater runoff and iceberg production, we are able to identify the processes that led to the recent mass loss. We conclude that the Greenland ice sheet is significantly out of balance. Acceleration of outlet glaciers and increased runoff have contributed equally to recent Greenland mass loss. The potential for mass loss by surface processes, however, was three times greater than actually observed, due to refreezing and enhanced snowfall.

  9. Numerical simulation of fragmentation of hot metal and oxide melts with the computer code IVA3

    International Nuclear Information System (INIS)

    Mussa, S.; Tromm, W.

    1994-01-01

    The phenomena of fragmentation of melts caused by water-inlet from the bottom with the computer code IVA3/11,12,13/ are investigated. With the computer code IVA3 three-component-multiphase flows can be numerically simulated. Two geometrical models are used. Both consist of a cylindrical vessel for water lying beneath a cylindrical vessel for melt. The vessels are connected to each other through a hole. Steel and UO 2 melts are. The following parameters were varied: the type of the melt (steel,UO 2 ), the water supply pressure and the geometry of the hole in the bottom plate through which the water and melt vessels are connected. As results of the numerical simulations temperature and pressure versus time curves are plotted. Additionally the volume flow rates and the volume fractions of the various phases in the vessels and the increase in surface and enthalpy of the melt during the time of simulation are depicted. With steel melts the rate of fragmentation increases with increasing water pressure and melt temperature, whereby stable channels are formed in the melt layer showing a very low flow resistance for steam. With UO 2 the formations of channels are also observed. However, these channels are not so stable that they eventually break apart and lead to the fragmentation of the UO 2 melt in drops. The fragmentation of the steel melt in water vessel is less than that of UO 2 . No essential solidification of the melt is observed in the respective duration of the simulations. However, a small drop in the melt temperature is observed. With a slight or no water pressure the melt flows from the upper vessel into the water vessel via the connecting hole. The processes take place in a very slow manner and with such a low steam production so that despite the occuring pressure peaks no sign of steam explosions could be observed. (orig./HP) [de

  10. Acoustic detection of melt particles

    International Nuclear Information System (INIS)

    Costley, R.D. Jr.

    1988-01-01

    The Reactor Safety Research Department at Sandia National Laboratories is investigating a type of Loss of Coolant Accident (LOCA). In this particular type of accident, core meltdown occurs while the pressure within the reactor pressure vessel (RPV) is high. If one of the instrument tube penetrations in the lower head fails, melt particles stream through the cavity and into the containment vessel. This experiment, which simulates this type accident, was performed in the Surtsev Direct Heating Test Facility which is approximately a 1:10 linear scaling of a large dry containment volume. A 1:10 linear scale model of the reactor cavity was placed near the bottom of the Surtsey vessel so that the exit of the cavity was at the vertical centerline of the vessel. A pressure vessel used to create the simulated molten core debris was located at the scaled height of the RPV. In order to better understand how the melt leaves the cavity and streams into the containment an array of five acoustic sensors was placed directly in the path of the melt particles about 30 feet from the exit of the sealed cavity. Highly damped, broadband sensors were chosen to minimize ringing so that individual particle hits could be detected. The goal was to count the signals produced by the individual particle hits to get some idea of how the melt particles left the cavity. This document presents some of the results of the experiment. 9 figs

  11. Thermodynamics of freezing and melting

    DEFF Research Database (Denmark)

    Pedersen, Ulf Rørbæk; Costigliola, Lorenzo; Bailey, Nicholas

    2016-01-01

    phases at a single thermodynamic state point provide the basis for calculating the pressure, density and entropy of fusion as functions of temperature along the melting line, as well as the variation along this line of the reduced crystalline vibrational mean-square displacement (the Lindemann ratio...

  12. Nuclear Safety Co-Ordination within Oak Ridge Operations Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, W. A.; Pryor, W. A. [Research and Development Division, United States Atomic Energy Commission, Oak Ridge, TN (United States)

    1966-05-15

    The Oak Ridge Operations Office of the USAEC has within its jurisdiction multiple contractors and facilities for research and for the production of fissile materials for the atomic energy programme. Among these facilities are gaseous diffusion plants for the production of {sup 235}U-enriched uranium hexafluoride, plants for the fabrication of special components and fuel for research and production reactors, and laboratories for pilot plant studies and basic research in nuclear technology. One research laboratory is also actively engaged in criticality experimental programmes and has been a major contributor of criticality data for safety applications. These diversified programmes include the processing, fabrication and transport of practically all forms and isotopic enrichments of uranium in quantities commensurate with both laboratory and volume production requirements. Consequently, adequate nuclear safety control with reasonable economy for operations of this magnitude demands not only co-ordination and liaison between contractor and USAEC staffs, but a continuing reappraisal of safety applications in light of the most advanced information. This report outlines the role of the Oak Ridge Operations Office in these pursuits and describes as examples some specific problems in which this office co-ordinated actions necessary for their resolution. Other examples are given of parametric and procedural applications in plant processes and fissile shipments emphasizing the use of recent experimental or calculated data. These examples involve the use of mass and geometric variables, neutron absorbers and moderation control. Departures from limits specified in existing nuclear safety guides are made to advantage in light of new data, special equipment design, contingencies and acceptable risks. (author)

  13. Implications of spinel compositions for the petrotectonic history of abyssal peridotite from Southwest Indian Ridge (SWIR)

    Science.gov (United States)

    Chen, T.; Jin, Z.; Wang, Y.; Tao, C.

    2012-12-01

    Abyssal peridotites generate at mid-ocean ridges. Lherzolite and harzburgite are the main rock types of peridotites in the uppermost mantle. The lherzolite subtype, less depleted and less common in ophiolites, characterizes mantle diapirs and slow-spreading ridges. Along the Earth's mid-ocean ridges, abyssal peridotites undergo hydration reactions to become serpentinite minerals, especially in slow to ultraslow spreading mid-ocean ridges. Spinel is common in small quantities in peridotites, and its compositions have often been used as petrogenetic indicators [1]. The Southwest Indian Ridge (SWIR) is one of the two ultraslow spreading ridges in the world. The studied serpentinized peridotite sample was collected by the 21st Voyage of the Chinese oceanic research ship Dayang Yihao (aka Ocean No. 1) from a hydrothermal field (63.5°E, 28.0°S, and 3660 m deep) in SWIR. The studied spinels in serpentinized lherzolite have four zones with different compositions: relic, unaltered core is magmatic Al-spinels; micro- to nano- sized ferrichromite zoned particles; narrow and discontinuous magnetite rim; and chlorite aureoles. The values Cr# of the primary Al-spinels indicate the range of melting for abyssal peridotites from SWIR extends from ~4% to ~7% [2]. The alteration rims of ferrichromite have a chemical composition characterized by Fe enrichment and Cr# increase indicating chromite altered under greenschist-amphibolite facies. Magnetites formed in syn- and post- serpentinization. Chlorite (clinochlore) formed at the boundary and crack of spinel indicating it had undergone with low-temperature MgO- and SiO2-rich hydrothermal fluids [3]. It suggests that serpentinized lherzolite from SWIR had undergone poly-stage hydration reactions with a wide range of temperature. Acknowledgments: EMPA experiment was carried out by Xihao Zhu and Shu Zheng in The Second Institute of Oceanography and China University of Geosciences, respectively. The work was supported by NSFC

  14. Unexpected HIMU-type late-stage volcanism on the Walvis Ridge

    Science.gov (United States)

    Homrighausen, S.; Hoernle, K.; Geldmacher, J.; Wartho, J.-A.; Hauff, F.; Portnyagin, M.; Werner, R.; van den Bogaard, P.; Garbe-Schönberg, D.

    2018-06-01

    Volcanic activity at many oceanic volcanoes, ridges and plateaus often reawakens after hiatuses of up to several million years. Compared to the earlier magmatic phases, this late-stage (rejuvenated/post-erosional) volcanism is commonly characterized by a distinct geochemical composition. Late-stage volcanism raises two hitherto unanswered questions: Why does volcanism restart after an extended hiatus and what is the origin of this volcanism? Here we present the first 40Ar/39Ar age and comprehensive trace element and Sr-Nd-Pb-Hf isotopic data from seamounts located on and adjacent to the Walvis Ridge in the South Atlantic ocean basin. The Walvis Ridge is the oldest submarine part of the Tristan-Gough hotspot track and is famous as the original type locality for the enriched mantle one (EM I) end member. Consistent with the bathymetric data, the age data indicates that most of these seamounts are 20-40 Myr younger than the underlying or nearby Walvis Ridge basement. The trace element and isotope data reveal a distinct compositional range from the EM I-type basement. The composition of the seamounts extend from the St. Helena HIMU (high time-integrated 238U/204Pb mantle with radiogenic Pb isotope ratios) end member to an enriched (E) Mid-Ocean-Ridge Basalt (MORB) type composition, reflecting a two-component mixing trend on all isotope diagrams. The EMORB end member could have been generated through mixing of Walvis Ridge EM I with normal (N) MORB source mantle, reflecting interaction of Tristan-Gough (EM I-type) plume melts with the upper mantle. The long volcanic quiescence and the HIMU-like geochemical signature of the seamounts are unusual for classical hotspot related late-stage volcanism, indicating that these seamounts are not related to the Tristan-Gough hotspot volcanism. Two volcanic arrays in southwestern Africa (Gibeon-Dicker Willem and Western Cape province) display similar ages to the late-stage Walvis seamounts and also have HIMU-like compositions

  15. Site characterization report for Building 3515 at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

    International Nuclear Information System (INIS)

    1994-08-01

    Building 3515 at Oak Ridge National Laboratory (ORNL), also known as the Fission Product Pilot Plant, is a surplus facility in the main plant area to the east of the South Tank Farm slated for decontamination and decommissioning (D ampersand D). The building consists of two concrete cells (north and south) on a concrete pad and was used to extract radioisotopes of ruthenium, strontium, cesium, cerium, rhenium and other elements from aqueous fission product waste. Site characterization activities of the building were initiated. The objective of the site characterization was to provide information necessary for engineering evaluation and planning of D ampersand D approaches, planning for personal protection of D ampersand D workers, and estimating waste volumes from D ampersand D activities. This site characterization report documents the investigation with a site description, a summary of characterization methods, chemical and radiological sample analysis results, field measurement results, and waste volume estimates

  16. Iron and oxygen isotope signatures of the Pea Ridge and Pilot Knob magnetite-apatite deposits, southeast Missouri, USA

    Science.gov (United States)

    Childress, Tristan; Simon, Adam C.; Day, Warren C.; Lundstrom, Craig C.; Bindeman, Ilya N.

    2016-01-01

    New O and Fe stable isotope ratios are reported for magnetite samples from high-grade massive magnetite of the Mesoproterozoic Pea Ridge and Pilot Knob magnetite-apatite ore deposits and these results are compared with data for other iron oxide-apatite deposits to shed light on the origin of the southeast Missouri deposits. The δ18O values of magnetite from Pea Ridge (n = 12) and Pilot Knob (n = 3) range from 1.0 to 7.0 and 3.3 to 6.7‰, respectively. The δ56Fe values of magnetite from Pea Ridge (n = 10) and Pilot Knob (n = 6) are 0.03 to 0.35 and 0.06 to 0.27‰, respectively. These δ18O and the δ56Fe values suggest that magnetite crystallized from a silicate melt (typical igneous δ56Fe ranges 0.06–0.49‰) and grew in equilibrium with a magmatic-hydrothermal aqueous fluid. We propose that the δ18O and δ56Fe data for the Pea Ridge and Pilot Knob magnetite-apatite deposits are consistent with the flotation model recently proposed by Knipping et al. (2015a), which invokes flotation of a magmatic magnetite-fluid suspension and offers a plausible explanation for the igneous (i.e., up to ~15.9 wt % TiO2 in magnetite) and hydrothermal features of the deposits.

  17. Unfaulting the Sardarapat Ridge, Southwest Armenia

    Science.gov (United States)

    Wetmore, P.; Connor, C.; Connor, L. J.; Savov, I. P.; Karakhanyan, A.

    2012-12-01

    Armenia is located near the core of contractional deformation associated with the collision between the Arabian and Eurasian tectonic plates. Several studies of this region, including portions of adjacent Georgia, Iran, and Turkey, have indicated that 1-2 mm/yr of intra-plate, north-south shortening is primarily accommodated by a network of E-W trending thrust faults, and NW-trending (dextral) and NE-trending (sinistral) strike-slip faults. One proposed fault in this network, the Sardarapat Fault (SF), was investigated as part of a regional seismic hazard assessment ahead of the installation of a replacement reactor at the Armenian Nuclear Power Plant (ANPP). The SF is primarily defined by the Sardarapat Ridge (SR), which is a WNW-trending, 40-70 m high topographic feature located just north of the Arax River and the Turkey-Armenia border. The stratigraphy comprising this ridge includes alluvium overlying several meters of lacustrine deposits above a crystal-rich basaltic lava flow that yields an Ar-Ar age of 0.9 +/- 0.02 Ma. The alluvial sediments on the ridge contain early Bronze age (3832-3470 BP) artifacts at an elevation 25 m above those of the surrounding alluvial plane. This has lead to the suggestion that the SR is bound to the south (the steepest side) by the SF, which is uplifting the ridge at a rate of 0.7 mm/yr. However, despite the prominence and trend of the ridge there are no unequivocal observations, such as scarps or exposures of fault rocks, to support the existence of the SF. The goal of the investigation of the SR area was to test various models for the formation of the ridge including faulting and combined volcanic and erosional processes. We therefore collected gravimetric, magnetic, magneto-tellurics (MT), and transient electromagnetic (TEM) data across an area of ~400 km2, and used correlations of stratigraphic data from coreholes drilled proximal to the study area to define the geometry of the contact between the basement and basin fill to

  18. Model selection in kernel ridge regression

    DEFF Research Database (Denmark)

    Exterkate, Peter

    2013-01-01

    Kernel ridge regression is a technique to perform ridge regression with a potentially infinite number of nonlinear transformations of the independent variables as regressors. This method is gaining popularity as a data-rich nonlinear forecasting tool, which is applicable in many different contexts....... The influence of the choice of kernel and the setting of tuning parameters on forecast accuracy is investigated. Several popular kernels are reviewed, including polynomial kernels, the Gaussian kernel, and the Sinc kernel. The latter two kernels are interpreted in terms of their smoothing properties......, and the tuning parameters associated to all these kernels are related to smoothness measures of the prediction function and to the signal-to-noise ratio. Based on these interpretations, guidelines are provided for selecting the tuning parameters from small grids using cross-validation. A Monte Carlo study...

  19. Fe-15Ni-13Cr austenitic stainless steels for fission and fusion reactor applications. I. Effects of minor alloying elements on precipitate phases in melt products and implication in alloy fabrication

    International Nuclear Information System (INIS)

    Lee, E.H.; Mansur, L.K.

    2000-01-01

    In an effort to develop alloys for fission and fusion reactor applications, 28Fe-15Ni-13Cr base alloys were fabricated by adding various combinations of the minor alloying elements, Mo, Ti, C, Si, P, Nb, and B. The results showed that a significant fraction of undesirable residual oxygen was removed as oxides when Ti, C, and Si were added. Accordingly, the concentrations of the latter three essential alloying elements were reduced also. Among these elements, Ti was the strongest oxide former, but the largest oxygen removal (over 80%) was observed when carbon was added alone without Ti, since gaseous CO boiled off during melting. This paper recommends an alloy melting procedure to mitigate solute losses while reducing the undesirable residual oxygen. In this work, 14 different types of precipitate phases were identified. Compositions of precipitate phases and their crystallographic data are documented. Finally, stability of precipitate phases was examined in view of Gibbs free energy of formation

  20. Oak Ridge National Laboratory Waste Management Plan

    International Nuclear Information System (INIS)

    1992-12-01

    The objective of the Oak Ridge National Laboratory Waste Management Plan is to compile and to consolidate information annually on how the ORNL Waste Management Program is conducted, which waste management facilities are being used to manage wastes, what forces are acting to change current waste management systems, what activities are planned for the forthcoming fiscal year (FY), and how all of the activities are documented

  1. ORNL (Oak Ridge National Laboratory) 89

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, T.D.; Appleton, B.R.; Jefferson, J.W.; Merriman, J.R.; Mynatt, F.R.; Richmond, C.R.; Rosenthal, M.W.

    1989-01-01

    This is the inaugural issues of an annual publication about the Oak Ridge National Laboratory. Here you will find a brief overview of ORNL, a sampling of our recent research achievements, and a glimpse of the directions we want to take over the next 15 years. A major purpose of ornl 89 is to provide the staff with a sketch of the character and dynamics of the Laboratory.

  2. ORNL [Oak Ridge National Laboratory] 89

    International Nuclear Information System (INIS)

    Anderson, T.D.; Appleton, B.R.; Jefferson, J.W.; Merriman, J.R.; Mynatt, F.R.; Richmond, C.R.; Rosenthal, M.W.

    1989-01-01

    This is the inaugural issues of an annual publication about the Oak Ridge National Laboratory. Here you will find a brief overview of ORNL, a sampling of our recent research achievements, and a glimpse of the directions we want to take over the next 15 years. A major purpose of ornl 89 is to provide the staff with a sketch of the character and dynamics of the Laboratory

  3. Oak Ridge National Laboratory Waste Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    The objective of the Oak Ridge National Laboratory Waste Management Plan is to compile and to consolidate information annually on how the ORNL Waste Management Program is conducted, which waste management facilities are being used to manage wastes, what forces are acting to change current waste management systems, what activities are planned for the forthcoming fiscal year (FY), and how all of the activities are documented.

  4. Estimation of structural strength of 38KhN3MFA steel, melted using different methods

    International Nuclear Information System (INIS)

    Kudrya, A.V.; Mochalov, B.V.; Fadeev, Yu.I.

    1982-01-01

    Quantity of steel melted by different methods using criteria of fracture mechanics is evaluated. Three technological variants of the 38KhN3MFA steel melting: acid Martin steel prepared by the duplex-process (melt 1); the main Martin steel melting with deoxidation and alloying in a ladle by liquid alloy and treatment with synthetic slag with argon purging after production (melt 2) and its electroslag remelt - ESP process (melt 3) are investigated. The analysis of the investigated melts has revealed that crack resistances of the acid Martin steel is higher than that of other melts at practically similar standard mechanical properties with 0.35 probability at 0.05 significance level in the low-tempered state; in the tempered state the best crack resistance is observed in the ESP main Martin steel. Metal of the main Martin melting has lower crack resistance as compared with other meltings at both strength levels. The results of the work point out the necessity of applying the criteria of fracture mechanics for obtaining an objective evaluation of the steel quality

  5. Global survey of lunar wrinkle ridge formation times

    Science.gov (United States)

    Yue, Z.; Michael, G. G.; Di, K.; Liu, J.

    2017-11-01

    Wrinkle ridges are a common feature of the lunar maria and record subsequent contraction of mare infill. Constraining the timing of wrinkle ridge formation from crater counts is challenging because they have limited areal extent and it is difficult to determine whether superposed craters post-date ridge formation or have alternatively been uplifted by the deformation. Some wrinkle ridges do allow determination to be made. This is possible where a ridge shows a sufficiently steep boundary or scarp that can be identified as deforming an intersecting crater or the crater obliterates the relief of the ridge. Such boundaries constitute only a small fraction of lunar wrinkle ridge structures yet they are sufficiently numerous to enable us to obtain statistically significant crater counts over systems of structurally related wrinkle ridges. We carried out a global mapping of mare wrinkle ridges, identifying appropriate boundaries for crater identification, and mapping superposed craters. Selected groups of ridges were analyzed using the buffered crater counting method. We found that, except for the ridges in mare Tranquilitatis, the ridge groups formed with average ages between 3.5 and 3.1 Ga ago, or 100-650 Ma after the oldest observable erupted basalts where they are located. We interpret these results to suggest that local stresses from loading by basalt fill are the principal agent responsible for the formation of lunar wrinkle ridges, as others have proposed. We find a markedly longer interval before wrinkle ridge formation in Tranquilitatis which likely indicates a different mechanism of stress accumulation at this site.

  6. Computationally efficient thermal-mechanical modelling of selective laser melting

    NARCIS (Netherlands)

    Yang, Y.; Ayas, C.; Brabazon, Dermot; Naher, Sumsun; Ul Ahad, Inam

    2017-01-01

    The Selective laser melting (SLM) is a powder based additive manufacturing (AM) method to produce high density metal parts with complex topology. However, part distortions and accompanying residual stresses deteriorates the mechanical reliability of SLM products. Modelling of the SLM process is

  7. Alveolar ridge keratosis - a retrospective clinicopathological study

    Science.gov (United States)

    2013-01-01

    Background Alveolar ridge keratosis (ARK) is a distinct, benign clinicopathological entity, characterized by a hyperkeratotic plaque or patch that occurs on the alveolar edentulous ridge or on the retromolar trigone, considered to be caused by chronic frictional trauma. The aim of this retrospective study is to present the clinicopathological features of 23 consecutive cases of ARK. Material and methods The 23 biopsy samples of ARK were selected and pathological features were revised (keratosis, acanthosis, surface architecture, and inflammation). Factors such as the patient’s gender, age, anatomical location, tobacco and alcohol use were analyzed. Results Sixteen out of the 23 cases studied were men and 7 women with a mean age of 55.05 (age ranged from 17 to 88 years). Thirteen cases had a history of tobacco habit, amongst whom, 4 also presented alcohol consumption. All the cases presented only unilateral lesions. Nineteen cases involved the retromolar trigone while 4 cases involved edentulous alveolar ridges. When observed microscopically, the lesions were mainly characterized by moderate to important hyperorthokeratosis. Inflammation was scanty or absent. In four of the cases, the presence of melanin pigment in the superficial corium or in the cytoplasm of macrophages was detected. None of the cases showed any features of dysplasia. Conclusion Our results reveal that ARK is a benign lesion. However, the high prevalence of smokers amongst the patients might suggest that some potentially malignant disorders such as tobacco associated leukoplakia may clinically mimic ARK. PMID:23587097

  8. The effect of melt composition on the partitioning of trace elements between titanite and silicate melt

    Science.gov (United States)

    Prowatke, S.; Klemme, S.

    2003-04-01

    The aim of this study is to systematically investigate the influence of melt composition on the partitioning of trace elements between titanite and different silicate melts. Titanite was chosen because of its important role as an accessory mineral, particularly with regard to intermediate to silicic alkaline and calc-alkaline magmas [e.g. 1] and of its relative constant mineral composition over a wide range of bulk compositions. Experiments at atmospheric pressure were performed at temperatures between 1150°C and 1050°C. Bulk compositions were chosen to represent a basaltic andesite (SH3 - 53% SiO2), a dacite (SH2 - 65 SiO2) and a rhyolite (SH1 - 71% SiO2). Furthermore, two additional experimental series were conducted to investigate the effect of Al-Na and the Na-K ratio of melts on partitioning. Starting materials consisted of glasses that were doped with 23 trace elements including some selected rare earth elements (La, Ce, Pr, Sm, Gd, Lu), high field strength elements (Zr, Hf, Nb, Ta) and large ion lithophile elements (Cs, Rb, Ba) and Th and U. The experimental run products were analysed for trace elements using secondary ion mass spectrometry at Heidelberg University. Preliminary results indicate a strong effect of melt composition on trace element partition coefficients. Partition coefficients for rare-earth elements uniformly show a convex-upward shape [2, 3], since titanite accommodates the middle rare-earth elements more readily than the light rare-earth elements or the heavy rare-earth elements. Partition coefficients for the rare-earth elements follow a parabolic trend when plotted against ionic radius. The shape of the parabola is very similar for all studied bulk compositions, the position of the parabola, however, is strongly dependent on bulk composition. For example, isothermal rare-earth element partition coefficients (such as La) are incompatible (D>1) in alkali-poor melt compositions. From our experimental data we present an model that combines

  9. Long-term evolution of a propagating non-transform offset on the Mid-Atlantic Ridge over the last 26 m.y.

    Science.gov (United States)

    Zheng, T.; Tucholke, B. E.; Lin, J.

    2017-12-01

    By making plate reconstructions from Chron 8n ( 26.54 Ma) to present and analyzing multibeam bathymetry, long-range HMR1 sidescan sonar images, residual mantle Bouguer gravity anomaly (RMBA) and gravity-derived crust thickness, we investigated the structure and evolution of a propagating non-transform discontinuity (NTD) and adjacent ridge segments that now intersect the Mid-Atlantic Ridge (MAR) axis at 25°37'N. The NTD has propagated consistently northward since Chron 8n at a rate of 4.76 km/m.y. Offset across the NTD since Chron 6an (22 Ma) has been right lateral and has ranged from 8-52 km. Key features are: 1) Inside-corner (IC) crust consistently has higher values of RMBA than the adjacent ridge segments, implying thinner crust. 2) IC crust typically exhibits elevated, irregular edifices. Slopes of the NTD walls are steeper at ICs than at outside corners (OCs). Steep (up to 40°), abrupt slopes are particularly pronounced at the IC on the north side of the NTD. 3) OC crust is deeper and normally exhibits long linear ridges that curve toward the MAR axis at the southern edge of the NTD but show little curvature at the northern edge. 4) Width of the NTD between its northern and southern walls (at mid-depth) has ranged from 2 to 22 km, averaging 15 km. 5) The NTD valley was intermittently crossed by individual ridges or blocks every 5-60 km (average 20 km) along the run of the NTD. The ridges curve along the transtensional plate boundary within the NTD but are often discontinuous. HMR1 data show lumpy small-scale topography and occasional volcanic cones on the ridges and blocks. Their intermittency indicates that melt intruded sporadically into the NTD. Propagation of the NTD occurred as the transtensional plate boundary within the NTD jumped northward from a volcanic ridge axis or block, apparently as magmatism waned. The jumps captured crust and transferred it to the east flank only within the NTD, not from the northern IC edifices. We propose two possible

  10. Groundwater quality monitoring well installation for Waste Area Grouping at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Environmental Restoration Program

    International Nuclear Information System (INIS)

    Mortimore, J.A.; Lee, T.A.

    1994-09-01

    This report documents the drilling and installation of 18 groundwater quality monitoring (GQM) wells on the perimeter of Waste Area Grouping (WAG) 11. WAG 11 (White Wing Scrap Yard) is located on the west end of East Fork Ridge between White Wing Road and the Oak Ridge Turnpike. The scrap yard is approximately 25 acres in size. The wells at WAG 11 were drilled and developed between January 1990 and October 1990. These wells were installed to characterize and assess the WAG in accordance with applicable Department of Energy, state, and Environmental Protection Agency regulatory requirements. The wells at WAG 11 were drilled with auger or air rotary rigs. Depending on the hydrogeologic conditions present at each proposed well location, one of four basic installation methods was utilized. Detailed procedures for well construction were specified by the Engineering Division to ensure that the wells would provide water samples representative of the aquifer. To ensure conformance with the specifications, Energy Systems Construction Engineering and ERCE provided continuous oversight of field activities. The purpose of the well installation program was to install GQM wells for groundwater characterization at WAG 11. Data packages produced during installation activities by the ERCE hydrogeologists are an important product of the program. These packages document the well drilling, installation, and development activities and provide valuable data for well sampling and WAG characterization. The forms contained in the packages include predrilling and postdrilling checklists, drilling and construction logs, development and hydraulic conductivity records, and quality control-related documents

  11. Phase 1 report on the Bear Creek Valley treatability study, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1997-04-01

    Bear Creek Valley (BCV) is located within the US Department of Energy (DOE) Oak Ridge Reservation and encompasses multiple waste units containing hazardous and radioactive wastes associated with past operations at the adjacent Oak Ridge Y-12 Plant. The BCV Remedial Investigation determined that disposal of wastes at the S-3 Site, Boneyard/Burnyard (BYBY), and Bear Creek Burial Grounds (BCBG) has caused contamination of both deep and shallow groundwater. The primary contaminants include uranium, nitrate, and VOCs, although other metals such as aluminum, magnesium, and cadmium persist. The BCV feasibility study will describe several remedial options for this area, including both in situ and ex situ treatment of groundwater. This Treatability Study Phase 1 Report describes the results of preliminary screening of treatment technologies that may be applied within BCV. Four activities were undertaken in Phase 1: field characterization, laboratory screening of potential sorbents, laboratory testing of zero valent iron products, and field screening of three biological treatment systems. Each of these activities is described fully in technical memos attached in Appendices A through G

  12. Phase 1 report on the Bear Creek Valley treatability study, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    Bear Creek Valley (BCV) is located within the US Department of Energy (DOE) Oak Ridge Reservation and encompasses multiple waste units containing hazardous and radioactive wastes associated with past operations at the adjacent Oak Ridge Y-12 Plant. The BCV Remedial Investigation determined that disposal of wastes at the S-3 Site, Boneyard/Burnyard (BYBY), and Bear Creek Burial Grounds (BCBG) has caused contamination of both deep and shallow groundwater. The primary contaminants include uranium, nitrate, and VOCs, although other metals such as aluminum, magnesium, and cadmium persist. The BCV feasibility study will describe several remedial options for this area, including both in situ and ex situ treatment of groundwater. This Treatability Study Phase 1 Report describes the results of preliminary screening of treatment technologies that may be applied within BCV. Four activities were undertaken in Phase 1: field characterization, laboratory screening of potential sorbents, laboratory testing of zero valent iron products, and field screening of three biological treatment systems. Each of these activities is described fully in technical memos attached in Appendices A through G.

  13. Computation and measurement of air temperature distribution of an industrial melt blowing die

    Directory of Open Access Journals (Sweden)

    Wu Li-Li

    2014-01-01

    Full Text Available The air flow field of the dual slot die on an HDF-6D melt blowing non-woven equipment is computed numerically. A temperature measurement system is built to measure air temperatures. The computation results tally with the measured results proving the correctness of the computation. The results have great valuable significance in the actual melt blowing production.

  14. Arctic sea-ice ridges—Safe heavens for sea-ice fauna during periods of extreme ice melt?

    Science.gov (United States)

    Gradinger, Rolf; Bluhm, Bodil; Iken, Katrin

    2010-01-01

    The abundances and distribution of metazoan within-ice meiofauna (13 stations) and under-ice fauna (12 stations) were investigated in level sea ice and sea-ice ridges in the Chukchi/Beaufort Seas and Canada Basin in June/July 2005 using a combination of ice coring and SCUBA diving. Ice meiofauna abundance was estimated based on live counts in the bottom 30 cm of level sea ice based on triplicate ice core sampling at each location, and in individual ice chunks from ridges at four locations. Under-ice amphipods were counted in situ in replicate ( N=24-65 per station) 0.25 m 2 quadrats using SCUBA to a maximum water depth of 12 m. In level sea ice, the most abundant ice meiofauna groups were Turbellaria (46%), Nematoda (35%), and Harpacticoida (19%), with overall low abundances per station that ranged from 0.0 to 10.9 ind l -1 (median 0.8 ind l -1). In level ice, low ice algal pigment concentrations (Turbellaria, Nematoda and Harpacticoida also were observed in pressure ridges (0-200 ind l -1, median 40 ind l -1), although values were highly variable and only medians of Turbellaria were significantly higher in ridge ice than in level ice. Median abundances of under-ice amphipods at all ice types (level ice, various ice ridge structures) ranged from 8 to 114 ind m -2 per station and mainly consisted of Apherusa glacialis (87%), Onisimus spp. (7%) and Gammarus wilkitzkii (6%). Highest amphipod abundances were observed in pressure ridges at depths >3 m where abundances were up to 42-fold higher compared with level ice. We propose that the summer ice melt impacted meiofauna and under-ice amphipod abundance and distribution through (a) flushing, and (b) enhanced salinity stress at thinner level sea ice (less than 3 m thickness). We further suggest that pressure ridges, which extend into deeper, high-salinity water, become accumulation regions for ice meiofauna and under-ice amphipods in summer. Pressure ridges thus might be crucial for faunal survival during periods of

  15. In situ vitrification demonstration for the stabilization of buried wastes at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Jacobs, G.K.; Spalding, B.P.; Carter, J.G.; Koegler, S.S.

    1987-01-01

    A demonstration of In Situ Vitrification (ISV) technology for the stabilization of radioactively contaminated soil sites at the Oak Ridge National Laboratory (ORNL) was successfully completed during July 1987. This demonstration is the first application of the ISV process not performed at the Hanford Site, where the technology was developed and patented by Pacific Northwest Laboratory (PNL). The joint ORNL-PNL pilot-scale demonstration was performed on a 3/8-scale trench (2 m deep x 1 m wide x 10 m long) that was constructed to simulate a typical seepage trench used for liquid low-level radioactive waste disposal at ORNL from 1951 to 1966. In the ISV process, electrodes are inserted around a volume of contaminated soil, power is applied to the electrodes, and the entire mass is melted from the surface of the soil down through the contaminated zone, thus making a glassy-to-microcrystalline waste form that incorporates the contaminants. Gases produced during the melting are collected, treated, monitored, and released through an off-gas process trailer. In the ORNL demonstration, a 25-t mass of melted rock approximately 1.2 m thick x 2.1 m wide x 4.9 m long was formed during 110 h of operation that consumed approximately 29 MWh of power. Data obtained on the operational performance of the test and waste-form durability will be used to assess the feasibility of applying the ISV technology to an actual waste trench

  16. On high-pressure melting of tantalum

    Science.gov (United States)

    Luo, Sheng-Nian; Swift, Damian C.

    2007-01-01

    The issues related to high-pressure melting of Ta are discussed within the context of diamond-anvil cell (DAC) and shock wave experiments, theoretical calculations and common melting models. The discrepancies between the extrapolations of the DAC melting curve and the melting point inferred from shock wave experiments, cannot be reconciled either by superheating or solid-solid phase transition. The failure to reproduce low-pressure DAC melting curve by melting models such as dislocation-mediated melting and the Lindemann law, and molecular dynamics and quantum mechanics-based calculations, undermines their predictions at moderate and high pressures. Despite claims to the contrary, the melting curve of Ta (as well as Mo and W) remains inconclusive at high pressures.

  17. The effects of buoyancy on shear-induced melt bands in a compacting porous medium

    Science.gov (United States)

    Butler, S. L.

    2009-03-01

    It has recently been shown [Holtzman, B., Groebner, N., Zimmerman, M., Ginsberg, S., Kohlstedt, D., 2003. Stress-driven melt segregation in partially molten rocks. Geochem. Geophys. Geosyst. 4, Art. No. 8607; Holtzman, B.K., Kohlstedt, D.L., 2007. Stress-driven melt segregation and strain partitioning in partially molten rocks: effects of stress and strain. J. Petrol. 48, 2379-2406] that when partially molten rock is subjected to simple shear, bands of high and low porosity are formed at a particular angle to the direction of instantaneous maximum extension. These have been modeled numerically and it has been speculated that high porosity bands may form an interconnected network with a bulk, effective permeability that is enhanced in a direction parallel to the bands. As a result, the bands may act to focus mantle melt towards the axis of mid-ocean ridges [Katz, R.F., Spiegelman, M., Holtzman, B., 2006. The dynamics of melt and shear localization in partially molten aggregates. Nature 442, 676-679]. In this contribution, we examine the combined effects of buoyancy and matrix shear on a deforming porous layer. The linear theory of Spiegelman [Spiegelman, M., 1993. Flow in deformable porous media. Part 1. Simple analysis. J. Fluid Mech. 247, 17-38; Spiegelman, M., 2003. Linear analysis of melt band formation by simple shear. Geochem. Geophys. Geosyst. 4, doi:10.1029/2002GC000499, Article 8615] and Katz et al. [Katz, R.F., Spiegelman, M., Holtzman, B., 2006. The dynamics of melt and shear localization in partially molten aggregates. Nature 442, 676-679] is generalized to include both the effects of buoyancy and matrix shear on a deformable porous layer with strain-rate dependent rheology. The predictions of linear theory are compared with the early time evolution of our 2D numerical model and they are found to be in excellent agreement. For conditions similar to the upper mantle, buoyancy forces can be similar to or much greater than matrix shear-induced forces. The

  18. Melting of fuel element racks and their recycling as granulate

    International Nuclear Information System (INIS)

    Quade, U.; Kluth, T.; Kreh, R.

    1998-01-01

    In order to increase the storage capacity for spent fuel elements in the Spanish NPPs of Almaraz and Asco, the existing racks were replaced by compact one in 1991/1993. The 28 racks from Almaraz NPP were cut on site, packed in 200-I-drums and taken to intermediate storage. For the remaining 28 racks of Asco NPP, ENRESA preferred the melting alternative. To demonstrate the recycling path melting in Germany, a test campaign with six racks was performed in 1997. As a result of this test melt, the limits for Carla melting plant were modified to 200 Bq/g total, α, β, γ 100 Bq/g nuclear fuels, max. 3g/100 kg 2,000 Bq/g total Fe55, H 3 , C-14 and Ni63. After the test melt campaign, the German authorities licensed the import and treatment of the remaining 22 racks on the condition that the waste resulting from the melting process as well as the granules produced were taken back to Spain. The shipment from Asco via France to Germany has been carried out in F 20-ft-IPII containers in accordance with ADR. Size reduction to chargeable dimensions was carried out by a plasma burner and hydraulic shears. For melting, a 3.2 Mg medium frequency induction furnace, operated in a separate housing, was used. For granules production outside this housing, the liquid iron was cast into a 5Mg ladle and then, through a water jet, into the granulating basin. The total mass of 287,659 Kg of 28 fuel elements racks and components of the storage basin yielded 297,914 kg of iron granulate. Secondary waste from melting amounted to 9,920 kg, corresponding to 3.45% of the input mass. The granulating process produced 6,589 kg, corresponding to 2.28% of the total mass to be melted. Radiological analysis of samples taken from the melt and different waste components confirmed the main nuclides Co60, Cs134 and Cs137. Fe55 was highly overestimated by the preliminary analysis. (Author) 2 refs

  19. On melting of boron phosphide under pressure

    OpenAIRE

    Solozhenko, Vladimir; Mukhanov, V. A.

    2015-01-01

    Melting of cubic boron phosphide, BP, has been studied at pressures to 9 GPa using synchrotron X-ray diffraction and electrical resistivity measurements. It has been found that above 2.6 GPa BP melts congruently, and the melting curve exhibits negative slope (–60 ± 7 K/GPa), which is indicative of a higher density of the melt as compared to the solid phase.

  20. The Taitao Granites: I-type granites formed by subduction of the Chile Ridge and its implication in growth of continental crusts

    Science.gov (United States)

    Anma, Ryo

    2016-04-01

    Late Miocene to Early Pliocene granite plutons are exposed at the tip of the Taitao peninsula, the westernmost promontory of the Chilean coast, together with a contemporaneous ophiolite with a Penrose-type stratigraphy. Namely, the Taitao granites and the Taitao ohiolite, respectively, are located at ~30 km southeast of the Chile triple junction, where a spreading center of the Chile ridge system is subducting underneath the South America plate. This unique tectonic setting provides an excellent opportunity to study the generation processes of granitic magmas at a ridge subduction environment, and the complex magmatic interactions between the subducting ridge, overlying crust and sediments, and mantle. This paper reviews previous studies on the Taitao ophiolite/granite complex and use geochemical data and U-Pb age distributions of zircons separated from igneous and sedimentary rocks from the area to discuss the mechanism that formed juvenile magma of calc-alkaline I-type granites during ridge subduction. Our model implies that the magmas of the Taitao granites formed mainly due to partial melting of hot oceanic crust adjacent to the subducting mid-oceanic ridge that has been under influence of deep crustal contamination and/or metasomatized sub-arc mantle through slab window. The partial melting took place under garnet-free-amphibolite conditions. The juvenile magmas then incorporated a different amount of subducted sediments to form the I-type granites with various compositions. The Taitao granites provide an ideal case study field that shows the processes to develop continental crusts out of oceanic crusts through ridge subduction.

  1. Design demonstrations for Category B tank systems at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1992-07-01

    This document presents design demonstrations conducted of liquid low-level waste (LLLW) storage tank systems located at the Oak Ridge National Laboratory (ORNL). ORNL has conducted research in energy related fields since 1943. The facilities used to conduct the research include nuclear reactors, chemical pilot plants, research laboratories, radioisotope production laboratories, and support facilities. These facilities have produced a variety of radioactive and/or hazardous wastes. These wastes have been stored and transported through an extensive network of piping and tankage. Demonstration of the design of these tank systems has been stipulated by the Federal Facility Agreement (FFA) between the US Environmental Protection Agency (EPA) - Region IV; the Tennessee Department of Environment and Conservation (TDEC); and the DOE. The FFA establishes four categories of tanks. These are: Category A -- New or Replacement Tank Systems with Secondary Containment; Category B -- Existing Tank Systems with Secondary Containment; Category C -- Existing Tank Systems without Secondary Containment; and Category D -- Existing Tank Systems without Secondary Containment that are; Removed from Service. This document provides a design demonstration of the secondary containment and ancillary equipment of 11 tank systems listed in the FFA as Category ''B.'' The design demonstration for each tank is presented in Section 2. The design demonstrations were developed using information obtained from the design drawings (as-built when available), construction specifications, and interviews with facility operators. The assessments assume that each tank system was constructed in accordance with the design drawings and construction specifications for that system unless specified otherwise. Each design demonstration addresses system conformance to the requirements of the FFA (Appendix F, Subsection C)

  2. Work plan for the Isotopes Facilities Deactivation Project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1995-08-01

    The purpose of the Isotopes Facilities Deactivation Project (IFDP) is to place former isotopes production facilities at the Oak Ridge National Laboratory in a safe, stable, and environmentally sound condition; suitable for an extended period of minimum surveillance and maintenance (S and M) and as quickly and economical as possible. Implementation and completion of the deactivation project will further reduce the risks to the environment and to public safety and health. Furthermore, completion of the project will result in significant S and M cost savings in future years. The IFDP work plan defines the project schedule, the cost estimate, and the technical approach for the project. A companion document, the EFDP management plan, has been prepared to document the project objectives, define organizational relationships and responsibilities, and outline the management control systems to be employed in the management of the project. The project has adopted the strategy of deactivating the simple facilities first, to reduce the scope of the project and to gain experience before addressing more difficult facilities. A decision support system is being developed to identify the activities that best promote the project mission and result in the largest cost savings. This work plan will be reviewed and revised annually. Deactivation of EFDP Facilities was initiated in FY 1994 and will be completed in FY 2000. The schedule for deactivation of facilities is shown. The total cost of the project is estimated to be $51M. The costs are summarized. Upon completion of deactivation, annual S and M costs of these facilities will be reduced from the current level of $5M per year to less than $1M per year

  3. Petrological Geodynamics of Mantle Melting I. AlphaMELTS + Multiphase Flow: Dynamic Equilibrium Melting, Method and Results

    Directory of Open Access Journals (Sweden)

    Massimiliano Tirone

    2017-10-01

    Full Text Available The complex process of melting in the Earth's interior is studied by combining a multiphase numerical flow model with the program AlphaMELTS which provides a petrological description based on thermodynamic principles. The objective is to address the fundamental question of the effect of the mantle and melt dynamics on the composition and abundance of the melt and the residual solid. The conceptual idea is based on a 1-D description of the melting process that develops along an ideal vertical column where local chemical equilibrium is assumed to apply at some level in space and time. By coupling together the transport model and the chemical thermodynamic model, the evolution of the melting process can be described in terms of melt distribution, temperature, pressure and solid and melt velocities but also variation of melt and residual solid composition and mineralogical abundance at any depth over time. In this first installment of a series of three contributions, a two-phase flow model (melt and solid assemblage is developed under the assumption of complete local equilibrium between melt and a peridotitic mantle (dynamic equilibrium melting, DEM. The solid mantle is also assumed to be completely dry. The present study addresses some but not all the potential factors affecting the melting process. The influence of permeability and viscosity of the solid matrix are considered in some detail. The essential features of the dynamic model and how it is interfaced with AlphaMELTS are clearly outlined. A detailed and explicit description of the numerical procedure should make this type of numerical models less obscure. The general observation that can be made from the outcome of several simulations carried out for this work is that the melt composition varies with depth, however the melt abundance not necessarily always increases moving upwards. When a quasi-steady state condition is achieved, that is when melt abundance does not varies significantly

  4. Alveolar ridge rehabilitation to increase full denture retention and stability

    Directory of Open Access Journals (Sweden)

    Mefina Kuntjoro

    2010-12-01

    Full Text Available Background: Atrophic mandibular alveolar ridge generally complicates prostetic restoration expecially full denture. Low residual alveolar ridge and basal seat can cause unstable denture, permanent ulcer, pain, neuralgia, and mastication difficulty. Pre-proshetic surgery is needed to improve denture retention and stability. Augmentation is a major surgery to increase vertical height of the atrophic mandible while vestibuloplasty is aimed to increase the denture bearing area. Purpose: The augmentation and vestibuloplasty was aimed to provide stability and retentive denture atrophic mandibular alveolar ridge. Case: A 65 years old woman patient complained about uncomfortable denture. Clinical evaluate showed flat ridge in the anterior mandible, flabby tissue and candidiasis, while residual ridge height was classified into class IV. Case management: Augmentation using autograph was conducted as the mandible vertical height is less than 15 mm. Autograph was used to achieve better bone quantity and quality. Separated alveolar ridge was conducted from left to right canine region and was elevated 0.5 mm from the previous position to get new ridge in the anterior region. The separated alveolar ridge was fixated by using T-plate and ligature wire. Three months after augmentation fixation appliances was removed vestibuloplasty was performed to increase denture bearing area that can make a stable and retentive denture. Conclusion: Augmentation and vestibuloplasty can improve flat ridge to become prominent.Latar belakang: Ridge mandibula yang atrofi pada umumnya mempersulit pembuatan restorasi prostetik terutama gigi tiruan lengkap (GTL. Residual alveolar ridge dan basal seat yang rendah menyebabkan gigi tiruan menjadi tidak stabil, menimbulkan ulser permanen, nyeri, neuralgia, dan kesulitan mengunyah. Tujuan: Augmentasi dan vestibuloplasti pada ridge mandibula yang atrofi dilakukan untuk menciptakan gigi tiruan yang stabil dan retentive. Kasus: Pasien wanita

  5. Filament stretching rheometry of polymer melts

    DEFF Research Database (Denmark)

    Hassager, Ole; Nielsen, Jens Kromann; Rasmussen, Henrik Koblitz

    2005-01-01

    The Filament Stretching Rheometry (FSR) method developed by Sridhar, McKinley and coworkers for polymer solutions has been extended to be used also for polymer melts. The design of a melt-FSR will be described and differences to conventional melt elongational rheometers will be pointed out. Results...

  6. Experiments on transient melting of tungsten by ELMs in ASDEX Upgrade

    Science.gov (United States)

    Krieger, K.; Balden, M.; Coenen, J. W.; Laggner, F.; Matthews, G. F.; Nille, D.; Rohde, V.; Sieglin, B.; Giannone, L.; Göths, B.; Herrmann, A.; de Marne, P.; Pitts, R. A.; Potzel, S.; Vondracek, P.; ASDEX-Upgrade Team; EUROfusion MST1 Team

    2018-02-01

    Repetitive melting of tungsten by power transients originating from edge localized modes (ELMs) has been studied in ASDEX Upgrade. Tungsten samples were exposed to H-mode discharges at the outer divertor target plate using the divertor manipulator II (DIM-II) system (Herrmann et al 2015 Fusion Eng. Des. 98-9 1496-9). Designed as near replicas of the geometries used also in separate experiments on the JET tokamak (Coenen et al 2015 J. Nucl. Mater. 463 78-84 Coenen et al 2015 Nucl. Fusion 55 023010; Matthews et al 2016 Phys. Scr. T167 7), the samples featured a misaligned leading edge and a sloped ridge respectively. Both structures protrude above the default target plate surface thus receiving an increased fraction of the parallel power flux. Transient melting by ELMs was induced by moving the outer strike point to the sample location. The temporal evolution of the measured current flow from the samples to vessel potential confirmed transient melting. Current magnitude and dependency from surface temperature provided strong evidence for thermionic electron emission as main origin of the replacement current driving the melt motion. The different melt patterns observed after exposures at the two sample geometries support the thermionic electron emission model used in the MEMOS melt motion code, which assumes a strong decrease of the thermionic net current at shallow magnetic field to surface angles (Pitts et al 2017 Nucl. Mater. Energy 12 60-74). Post exposure ex situ analysis of the retrieved samples show recrystallization of tungsten at the exposed surface areas to a depth of up to several mm. The melt layer transport to less exposed surface areas leads to ratcheting pile up of re-solidified debris with zonal growth extending from the already enlarged grains at the surface.

  7. Stagnation and Storage of Strongly Depleted Melts in Slow-Ultraslow Spreading Oceans: Evidence from the Ligurian Tethys

    Science.gov (United States)

    Piccardo, Giovanni; Guarnieri, Luisa; Padovano, Matteo

    2013-04-01

    mantle lithosphere under plagioclase-facies conditions, at shallow lithospheric levels, under brittle conditions and, frequently, after serpentinization. The presence and abundance of strongly depleted melts, which stagnated and were stored in the shallow mantle lithosphere, represent characteristic features of the Ligurian Tethys slow-ultraslow spreading basin. In modern oceans, plagioclase-enriched peridotites are abundant at slow-ultraslow spreading ridges (i.e., Mid-Atlantic Ridge, South-West Indian Ridge and Gakkel Ridge) and were recognized as melt-impregnated peridotites. Moreover, a peculiar gabbro-norite suite was found at MAR DSDP Site 334, indicating the presence of rocks formed by silica-saturated, strongly trace element depleted melts. So far, few studies have been devoted to abyssal plagioclase peridotites despite their relatively high abundance (30% of abyssal peridotites), because of their widespread sea-floor alteration. In some cases, rock freshness allowed us to recognize that the compositions of the plagioclase and clinopyroxene were in equilibrium with the percolated, strongly trace element depleted melts, which were stagnated in the shallow oceanic mantle lithosphere. The presence, abundance and stagnation of silica-saturated, strongly trace element depleted melts in the shallow mantle lithosphere to form plagioclase-enriched peridotites and gabbro-norites, seem to be characteristic and discriminant features of fossil and modern slow-ultraslow spreading basins.

  8. Development and melt growth of novel scintillating halide crystals

    Science.gov (United States)

    Yoshikawa, Akira; Yokota, Yuui; Shoji, Yasuhiro; Kral, Robert; Kamada, Kei; Kurosawa, Shunsuke; Ohashi, Yuji; Arakawa, Mototaka; Chani, Valery I.; Kochurikhin, Vladimir V.; Yamaji, Akihiro; Andrey, Medvedev; Nikl, Martin

    2017-12-01

    Melt growth of scintillating halide crystals is reviewed. The vertical Bridgman growth technique is still considered as very popular method that enables production of relatively large and commercially attractive crystals. On the other hand, the micro-pulling-down method is preferable when fabrication of small samples, sufficient for preliminary characterization of their optical and/or scintillation performance, is required. Moreover, bulk crystal growth is also available using the micro-pulling-down furnace. The examples of growths of various halide crystals by industrially friendly melt growth techniques including Czochralski and edge-defined film-fed growth methods are also discussed. Finally, traveling molten zone growth that in some degree corresponds to horizontal zone melting is briefly overviewed.

  9. An aerial radiological survey of the Oak Ridge Reservation and surrounding area, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Maurer, R.J.

    1989-09-01

    An aerial radiological survey of the Oak Ridge Reservation (ORR) and surrounding area in Oak Ridge, Tennessee, was conducted from September 12--29, 1989. The purpose of the survey was to measure and document the site's terrestrial radiological environment for use in effective environmental management and emergency response planning. The aerial survey was flown at an altitude of 91 meters (300 feet) along a series of parallel lines 152 meters (500 feet) apart. The survey encompassed an area of 440 square kilometers (170 square miles) as defined by the Tennessee Valley Authority Map S-16A of the entire Oak Ridge Reservation and adjacent area. The results of the aerial survey are reported as inferred exposure rates at 1 meter above ground level (AGL) in the form of a radiation contour map. Typical background exposure rates were found to vary from 5 to 14 microroentgens per hour (μR/h). The man-made radionuclides, cobalt-60, cesium-137, and protactinium-234m (a radioisotope indicative of depleted uranium), were detected at several facilities on the site. In support of the aerial survey, ground-based exposure rate and soil sample measurements were obtained at several locations within the survey boundary. In addition to the large scale aerial survey, two special flyovers were requested by the Department of Energy. The first request was to conduct a survey of a 1-mile x 2-mile area in south Knoxville, Tennessee. The area had been used previously to store contaminated scrap metals from operations at the Oak Ridge site. The second request was to fly several passes over a 5-mile length of railroad tracks leading from the Oak Ridge Y-12 Plant, north through the city of Oak Ridge. The railroad tracks had been previously used in the transport of cesium-137

  10. Deep and persistent melt layer in the Archaean mantle

    Science.gov (United States)

    Andrault, Denis; Pesce, Giacomo; Manthilake, Geeth; Monteux, Julien; Bolfan-Casanova, Nathalie; Chantel, Julien; Novella, Davide; Guignot, Nicolas; King, Andrew; Itié, Jean-Paul; Hennet, Louis

    2018-02-01

    The transition from the Archaean to the Proterozoic eon ended a period of great instability at the Earth's surface. The origin of this transition could be a change in the dynamic regime of the Earth's interior. Here we use laboratory experiments to investigate the solidus of samples representative of the Archaean upper mantle. Our two complementary in situ measurements of the melting curve reveal a solidus that is 200-250 K lower than previously reported at depths higher than about 100 km. Such a lower solidus temperature makes partial melting today easier than previously thought, particularly in the presence of volatiles (H2O and CO2). A lower solidus could also account for the early high production of melts such as komatiites. For an Archaean mantle that was 200-300 K hotter than today, significant melting is expected at depths from 100-150 km to more than 400 km. Thus, a persistent layer of melt may have existed in the Archaean upper mantle. This shell of molten material may have progressively disappeared because of secular cooling of the mantle. Crystallization would have increased the upper mantle viscosity and could have enhanced mechanical coupling between the lithosphere and the asthenosphere. Such a change might explain the transition from surface dynamics dominated by a stagnant lid on the early Earth to modern-like plate tectonics with deep slab subduction.

  11. Supercoil Formation During DNA Melting

    Science.gov (United States)

    Sayar, Mehmet; Avsaroglu, Baris; Kabakcioglu, Alkan

    2009-03-01

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

  12. Segmentation and Contrasting Magma Supply Along the South-East Indian Ridge, 130°E to 140°E: Results of the STORM Cruise

    Science.gov (United States)

    Briais, A.; Ruellan, E.; Maia, M.; Hemond, C.; Hanan, B. B.; Ceuleneer, G.; Graham, D. W.; Park, S. H.

    2017-12-01

    We present observations of the South-East Indian Ridge (SEIR) between 130°E to 140°E, mostly collected during the STORM cruise (South Tasmania Ocean Ridge and Mantle) on the N/O L'Atalante. The SEIR displays large variations of axial depth despite an almost constant intermediate full spreading rate of 75 km/m.y. In the study area the analysis of multibeam bathymetry maps shows that the axis displays a rise morphology to the east away from the discontinuities, and a rifted high morphology in the west and near the OSCs, as often observed along intermediate-spreading mid-ocean ridges. The ridge axis is offset by 27 km at 131°E and 20 km at 135°E by two large-offset overlapping spreading centers (OSCs) propagating westward, and by a smaller OSC at 137°17'E. These OSCs define four second-order ridge segments (A2 to A5 from west to east). We observe a general shallowing of the ridge axis from 3100 m depth in the west to 2400 m depth in the east, and a prominent deepening of the axis near the large OSCs. The easternmost segment A5 shows a very shallow axial ridge suggesting a robust magma supply despite its proximity to the George V transform fault (140°E). Major element variations in basalt glasses are systematically related to morphotectonic segmentation of the ridge axis, showing contrasts in crystal fractionation from one segment to another that may relate to differences in replenishment of axial melt lenses by primitive melts. Along segment A5, crystallization increases with proximity to the George V transform fault, consistent with an expected cold edge effect. In contrast, along segment A3 the extent of crystallization increases progressively from east to west in the direction of ridge propagation. *STORM Cruise Scientific Party: F. Barrere, C. Boulart, A. Briais, D. Brunelli, G. Ceuleneer, N. Ferreira, D. Graham, B. Hanan, C. Hémond, S. Macleod, M. Maia, A. Maillard, S. Merkuryev, S.H. Park, S. Révillon, E. Ruellan, A. Schohn, S. Watson, and Y.S. Yang.

  13. Generation of Silicic Melts in the Early Izu-Bonin Arc Recorded by Detrital Zircons in Proximal Arc Volcaniclastic Rocks From the Philippine Sea

    Science.gov (United States)

    Barth, A. P.; Tani, K.; Meffre, S.; Wooden, J. L.; Coble, M. A.; Arculus, R. J.; Ishizuka, O.; Shukle, J. T.

    2017-10-01

    A 1.2 km thick Paleogene volcaniclastic section at International Ocean Discovery Program Site 351-U1438 preserves the deep-marine, proximal record of Izu-Bonin oceanic arc initiation, and volcano evolution along the Kyushu-Palau Ridge (KPR). Pb/U ages and trace element compositions of zircons recovered from volcaniclastic sandstones preserve a remarkable temporal record of juvenile island arc evolution. Pb/U ages ranging from 43 to 27 Ma are compatible with provenance in one or more active arc edifices of the northern KPR. The abundances of selected trace elements with high concentrations provide insight into the genesis of U1438 detrital zircon host melts, and represent useful indicators of both short and long-term variations in melt compositions in arc settings. The Site U1438 zircons span the compositional range between zircons from mid-ocean ridge gabbros and zircons from relatively enriched continental arcs, as predicted for melts in a primitive oceanic arc setting derived from a highly depleted mantle source. Melt zircon saturation temperatures and Ti-in-zircon thermometry suggest a provenance in relatively cool and silicic melts that evolved toward more Th and U-rich compositions with time. Th, U, and light rare earth element enrichments beginning about 35 Ma are consistent with detrital zircons recording development of regional arc asymmetry and selective trace element-enriched rear arc silicic melts as the juvenile Izu-Bonin arc evolved.

  14. Neutron Imaging for Selective Laser Melting Inconel Hardware with Internal Passages

    Science.gov (United States)

    Tramel, Terri L.; Norwood, Joseph K.; Bilheux, Hassina

    2014-01-01

    Additive Manufacturing is showing great promise for the development of new innovative designs and large potential life cycle cost reduction for the Aerospace Industry. However, more development work is required to move this technology into space flight hardware production. With selective laser melting (SLM), hardware that once consisted of multiple, carefully machined and inspected pieces, joined together can be made in one part. However standard inspection techniques cannot be used to verify that the internal passages are within dimensional tolerances or surface finish requirements. NASA/MSFC traveled to Oak Ridge National Lab's (ORNL) Spallation Neutron Source to perform some non-destructive, proof of concept imaging measurements to assess the capabilities to understand internal dimensional tolerances and internal passages surface roughness. This presentation will describe 1) the goals of this proof of concept testing, 2) the lessons learned when designing and building these Inconel 718 test specimens to minimize beam time, 3) the neutron imaging test setup and test procedure to get the images, 4) the initial results in images, volume and a video, 4) the assessment of using this imaging technique to gather real data for designing internal flow passages in SLM manufacturing aerospace hardware, and lastly 5) how proper cleaning of the internal passages is critically important. In summary, the initial results are very promising and continued development of a technique to assist in SLM development for aerospace components is desired by both NASA and ORNL. A plan forward that benefits both ORNL and NASA will also be presented, based on the promising initial results. The initial images and volume reconstruction showed that clean, clear images of the internal passages geometry are obtainable. These clear images of the internal passages of simple geometries will be compared to the build model to determine any differences. One surprising result was that a new cleaning

  15. Modeling and analysis framework for core damage propagation during flow-blockage-initiated accidents in the advanced neutron source reactor at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.H.; Taleyarkhan, R.P.; Navarro-Valenti, S.; Georgevich, V. [Oak Ridge National Lab., TN (United States)

    1995-09-01

    This paper describes modeling and analysis to evaluate the extent of core damage during flow blockage events in the Advanced Neutron Source (ANS) reactor planned to be built at the Oak Ridge National Laboratory (ORNL). Damage propagation is postulated to occur from thermal conduction between damaged and undamaged plates due to direct thermal contact. Such direct thermal contact may occur because of fuel plate swelling during fission product vapor release or plate buckling. Complex phenomena of damage propagation were modeled using a one-dimensional heat transfer model. A scoping study was conducted to learn what parameters are important for core damage propagation, and to obtain initial estimates of core melt mass for addressing recriticality and steam explosion events. The study included investigating the effect of the plate contact area, the convective heat transfer coefficient, thermal conductivity upon fuel swelling, and the initial temperature of the plate being contacted by the damaged plate. Also, the side support plates were modeled to account for their effects on damage propagation. The results provide useful insights into how various uncertain parameters affect damage propagation.

  16. Real-Time N2O Gas Detection System for Agricultural Production Using a 4.6-µm-Band Laser Source Based on a Periodically Poled LiNbO3 Ridge Waveguide

    Directory of Open Access Journals (Sweden)

    Toshihiro Yoshihara

    2013-08-01

    Full Text Available This article describes a gas monitoring system for detecting nitrous oxide (N2O gas using a compact mid-infrared laser source based on difference-frequency generation in a quasi-phase-matched LiNbO3 waveguide. We obtained a stable output power of 0.62 mW from a 4.6-μm-band continuous-wave laser source operating at room temperature. This laser source enabled us to detect atmospheric N2O gas at a concentration as low as 35 parts per billion. Using this laser source, we constructed a new real-time in-situ monitoring system for detecting N2O gas emitted from potted plants. A few weeks of monitoring with the developed detection system revealed a strong relationship between nitrogen fertilization and N2O emission. This system is promising for the in-situ long-term monitoring of N2O in agricultural production, and it is also applicable to the detection of other greenhouse gases.

  17. Real-time N2O gas detection system for agricultural production using a 4.6-µm-band laser source based on a periodically poled LiNbO3 ridge waveguide.

    Science.gov (United States)

    Tokura, Akio; Asobe, Masaki; Enbutsu, Koji; Yoshihara, Toshihiro; Hashida, Shin-nosuke; Takenouchi, Hirokazu

    2013-08-05

    This article describes a gas monitoring system for detecting nitrous oxide (N2O) gas using a compact mid-infrared laser source based on difference-frequency generation in a quasi-phase-matched LiNbO3 waveguide. We obtained a stable output power of 0.62 mW from a 4.6-μm-band continuous-wave laser source operating at room temperature. This laser source enabled us to detect atmospheric N2O gas at a concentration as low as 35 parts per billion. Using this laser source, we constructed a new real-time in-situ monitoring system for detecting N2O gas emitted from potted plants. A few weeks of monitoring with the developed detection system revealed a strong relationship between nitrogen fertilization and N2O emission. This system is promising for the in-situ long-term monitoring of N2O in agricultural production, and it is also applicable to the detection of other greenhouse gases.

  18. Industrial opportunities of controlled melt flow during glass melting, part 1: Melt flow evaluation

    Czech Academy of Sciences Publication Activity Database

    Dyrčíková, Petra; Hrbek, Lukáš; Němec, Lubomír

    2014-01-01

    Roč. 58, č. 2 (2014), s. 111-117 ISSN 0862-5468 R&D Projects: GA TA ČR TA01010844 Institutional support: RVO:67985891 Keywords : glass melting * controlled flow * space utilization Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.435, year: 2014 http://www.ceramics-silikaty.cz/2014/pdf/2014_02_111.pdf

  19. Pre prosthetic reconstruction of alveolar ridge

    Directory of Open Access Journals (Sweden)

    Prabhuji Munivenkatappa Lakshmaiahenkatesh

    2011-01-01

    Full Text Available Dento-alveolar bony defects are common and occur due to a variety of causes, such as, pulpal pathology, traumatic tooth extraction, advanced periodontal disease, implant failure, tumor or congenital anomalies. These defects often cause a significant problem in dental treatment and rehabilitation. Many techniques exist for effective soft and hard tissue augmentation. The approach is largely based on the extent of the defect and specific procedures to be performed for the implant or prosthetic rehabilitation. This article presents case reports of soft and hard tissue ridge augmentation.

  20. Oak Ridge Reservation environmental report for 1991

    International Nuclear Information System (INIS)

    Mucke, P.C.

    1992-10-01

    The first two volumes of this report present data and supporting narratives regarding the impact of the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) on its surrounding environs and the public during 1991. Volume 1 includes all narrative descriptions, summaries, and conclusions and is intended to be a ''stand-alone'' report for the reader who does not want to review in detail all of the 1991 data for the ORR. This volume, Volume 2, includes the detailed data formats that ensure all the environmental data are represented. Narratives are not included. The information in Vol. 2 is addressed and analyzed in Vol. 1

  1. Oak Ridge Reservation environmental report for 1992

    International Nuclear Information System (INIS)

    Koncinski, W.S.

    1993-09-01

    The two volumes of this report present data and supporting narratives regarding the impact of the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) on its environs and the public during 1992. Volume 1 includes all narrative descriptions, summaries, and conclusions and is intended to be a ''stand-alone'' report for the reader who does not want to review in detail all of the 1992 data for the ORR. This volume (volume 2) includes the detailed data in formats that ensure all the environmental data are presented. Narratives are not included in Vol. 2

  2. The rise and fall of the ridge

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, Paul [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2011-04-01

    Recent data from heavy ion collisions at RHIC show unexpectedly large near-angle correlations that broaden longitudinally with centrality. The amplitude of this ridge-like correlation rises rapidly with centrality, reaches a maximum, and then falls in the most central collisions. In this talk we explain how this behavior can be easily understood in a picture where final momentum-space correlations are driven by initial coordinate space density fluctuations. We propose {nu}{sub n}{sup 2}/{epsilon}{sub n,part}{sup 2} as a useful way to study these effects and explain what it tells us about the collision dynamics.

  3. Oak Ridge TNS Program: a status report

    International Nuclear Information System (INIS)

    Roberts, M.

    1978-01-01

    The Oak Ridge TNS activities have been directed at characterizing the design space between TFTR and EPR with a fundamental emphasis on higher beta plasma systems than previously projected, i.e., anti β approximately 5 to 10% as compared to 1 to 3%. Based on the results of the FY 1977 System Studies, our activities this year are directed toward preconceptual design with particular emphasis placed on reducing the technological requirements through innovations in plasma engineering. Examples of the new innovations include microwave assisted start up to reduce power requirements and a reduced TF ripple constraint by more refined ripple loss calculations, to increase engineering feasibility through simpler, more maintainable designs

  4. Oak Ridge Reservation environmental report for 1992

    International Nuclear Information System (INIS)

    Koncinski, W.S.

    1993-09-01

    The two volumes of this report present data and supporting narratives regarding the impact of the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) on its environs and the public during 1992. This Volume (Volume 1) includes all narrative descriptions, summaries, and conclusions and is intended to be a ''stand-alone'' report for the reader who does not want to review in detail all of the 1992 data for the ORR. Volume 2 includes the detailed data in formats that ensure all the environmental data are represented. Narratives are not included in Vol. 2

  5. Oak Ridge Leadership Computing Facility Position Paper

    Energy Technology Data Exchange (ETDEWEB)

    Oral, H Sarp [ORNL; Hill, Jason J [ORNL; Thach, Kevin G [ORNL; Podhorszki, Norbert [ORNL; Klasky, Scott A [ORNL; Rogers, James H [ORNL; Shipman, Galen M [ORNL

    2011-01-01

    This paper discusses the business, administration, reliability, and usability aspects of storage systems at the Oak Ridge Leadership Computing Facility (OLCF). The OLCF has developed key competencies in architecting and administration of large-scale Lustre deployments as well as HPSS archival systems. Additionally as these systems are architected, deployed, and expanded over time reliability and availability factors are a primary driver. This paper focuses on the implementation of the Spider parallel Lustre file system as well as the implementation of the HPSS archive at the OLCF.

  6. Multimode Interference: Identifying Channels and Ridges in Quantum Probability Distributions

    OpenAIRE

    O'Connell, Ross C.; Loinaz, Will

    2004-01-01

    The multimode interference technique is a simple way to study the interference patterns found in many quantum probability distributions. We demonstrate that this analysis not only explains the existence of so-called "quantum carpets," but can explain the spatial distribution of channels and ridges in the carpets. With an understanding of the factors that govern these channels and ridges we have a limited ability to produce a particular pattern of channels and ridges by carefully choosing the ...

  7. Petrology of the axial ridge of the Mariana Trough backarc spreading center

    International Nuclear Information System (INIS)

    Hawkins, J.W.; Lonsdale, P.F.; Macdougall, J.D.; Volpe, A.M.

    1990-01-01

    The axial ridge of the Mariana Trough backarc basin, between 17deg40'N and 18deg30'N rises as much as 1 km above the floor of a 10-15 km wide rift valley. Physiographic segmentation, with minor ridge offsets and overlaps, coincides with a petrologic segmentation seen in trace element and isotope chemistry. Analyses of 239 glass and 40 aphyric basalt samples, collected with ALVIN and by dredging, show that the axial ridge is formed largely of (olivine) hypersthene-normative tholeiitic basalt. About half of these are enriched in both LIL elements and volatiles, but are depleted in HFS elements like other rocks found throughout much of the Mariana Trough. The LIL enrichments distinguish these rocks from N-MORB even though Nd and Sr isotope ratios indicate that much of the crust formed from a source similar to that for N-MORB. In addition to LIL-enriched basalt there is LIL depleted basalts even more closely resembling N-MORB in major and trace elements as well as Sr, Nd and Pb isotopes. Both basalt varieties have higher Al and lower total Fe than MORB at equivalent Mg level. Mg ranges from relatively ''primitive'' (e.g. Mg 65-70) to more highly fractionated (e.g. Mg 45-50). Highest parts of the axial ridge are capped by pinnacles with elongated pillows of basaltic andesite (e.g. 52-56%) SiO 2 . These are due to extreme fractional crystallization of basalts forming the axial ridge. Active hydrothermal vents with chimneys and mats of opaline silica, barite, sphalerite and lesser amounts of pyrite, chalcopyrite and galena formed near these silicic rocks. The vents are surrounded by distinctive vent animals, polychaete worms, crabs and barnacles. Isotope data indicate that the Mariana Trough crust was derived from a heterogeneous source including mantle resembling the MORB-source and an ''arc-source'' component. The latter was depleted in HFS elements in previous melting events and later modified by addition of H 2 O and LIL elements. (orig.)

  8. Removal action report on the Building 3001 canal at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1997-05-01

    Oak Ridge National Laboratory (ORNL) is a federal facility managed by Lockheed Martin C, Energy Research, Inc., for the U.S. Department of Energy (DOE). ORNL on the Oak Ridge Reservation in East Tennessee at the Anderson and Roane County lines, approximately 38 km (24 miles) west of Knoxville, Tennessee, and 18 km (11 miles) southwest of downtown Oak Ridge. The Oak Ridge Graphite Reactor and its storage and transfer canal are located in Bldg. 3001 in the approximate center of Waste Area Grouping I in the ORNL main complex. 4:1 The Bldg. 3001 Storage Canal is an L-shaped, underground, reinforced-concrete structure running from the back and below the Graphite Reactor in Bldg. 3001 to a location beneath a hot cell in the adjacent Bldg. 3019. The Graphite Reactor was built in 1943 to produce small quantities of plutonium and was subsequently used to produce other isotopes for medical research before it was finally shut down in 1963. The associated canal was used to transport, under water, spent fuel slugs and other isotopes from the back of the reactor to the adjacent Bldg. 31319 hot cell for further processing. During its operation and years subsequent to operation, the canal's concrete walls and floor became contaminated with radioisotopes from the water.This report documents the activities involved with replacing the canal water with a solid, controlled, low-strength material (CLSM) in response to a Comprehensive Environmental Response, Compensation, and Liability Act non-time-critical removal action

  9. Comprehensive integrated planning: A process for the Oak Ridge Reservation, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1998-05-01

    The Oak Ridge Comprehensive Integrated Plan is intended to assist the US Department of Energy (DOE) and contractor personnel in implementing a comprehensive integrated planning process consistent with DOE Order 430.1, Life Cycle Asset Management and Oak Ridge Operations Order 430. DOE contractors are charged with developing and producing the Comprehensive Integrated Plan, which serves as a summary document, providing information from other planning efforts regarding vision statements, missions, contextual conditions, resources and facilities, decision processes, and stakeholder involvement. The Comprehensive Integrated Plan is a planning reference that identifies primary issues regarding major changes in land and facility use and serves all programs and functions on-site as well as the Oak Ridge Operations Office and DOE Headquarters. The Oak Ridge Reservation is a valuable national resource and is managed on the basis of the principles of ecosystem management and sustainable development and how mission, economic, ecological, social, and cultural factors are used to guide land- and facility-use decisions. The long-term goals of the comprehensive integrated planning process, in priority order, are to support DOE critical missions and to stimulate the economy while maintaining a quality environment

  10. Comprehensive integrated planning: A process for the Oak Ridge Reservation, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-05-01

    The Oak Ridge Comprehensive Integrated Plan is intended to assist the US Department of Energy (DOE) and contractor personnel in implementing a comprehensive integrated planning process consistent with DOE Order 430.1, Life Cycle Asset Management and Oak Ridge Operations Order 430. DOE contractors are charged with developing and producing the Comprehensive Integrated Plan, which serves as a summary document, providing information from other planning efforts regarding vision statements, missions, contextual conditions, resources and facilities, decision processes, and stakeholder involvement. The Comprehensive Integrated Plan is a planning reference that identifies primary issues regarding major changes in land and facility use and serves all programs and functions on-site as well as the Oak Ridge Operations Office and DOE Headquarters. The Oak Ridge Reservation is a valuable national resource and is managed on the basis of the principles of ecosystem management and sustainable development and how mission, economic, ecological, social, and cultural factors are used to guide land- and facility-use decisions. The long-term goals of the comprehensive integrated planning process, in priority order, are to support DOE critical missions and to stimulate the economy while maintaining a quality environment.

  11. Hydrothermal activity at slow-spreading ridges: variability and importance of magmatic controls

    Science.gov (United States)

    Escartin, Javier

    2016-04-01

    Hydrothermal activity along mid-ocean ridge axes is ubiquitous, associated with mass, chemical, and heat exchanges between the deep lithosphere and the overlying envelopes, and sustaining chemiosynthetic ecosystems at the seafloor. Compared with hydrothermal fields at fast-spreading ridges, those at slow spreading ones show a large variability as their location and nature is controlled or influenced by several parameters that are inter-related: a) tectonic setting, ranging from 'volcanic systems' (along the rift valley floor, volcanic ridges, seamounts), to 'tectonic' ones (rift-bounding faults, oceanic detachment faults); b) the nature of the host rock, owing to compositional heterogeneity of slow-spreading lithosphere (basalt, gabbro, peridotite); c) the type of heat source (magmatic bodies at depth, hot lithosphere, serpentinization reactions); d) and the associated temperature of outflow fluids (high- vs.- low temperature venting and their relative proportion). A systematic review of the distribution and characteristics of hydrothermal fields along the slow-spreading Mid-Atlantic Ridge suggests that long-lived hydrothermal activity is concentrated either at oceanic detachment faults, or along volcanic segments with evidence of robust magma supply to the axis. A detailed study of the magmatically robust Lucky Strike segment suggests that all present and past hydrothermal activity is found at the center of the segment. The association of these fields to central volcanos, and the absence of indicators of hydrothermal activity along the remaining of the ridge segment, suggests that long-lived hydrothermal activity in these volcanic systems is maintained by the enhanced melt supply and the associated magma chamber(s) required to build these volcanic edifices. In this setting, hydrothermal outflow zones at the seafloor are systematically controlled by faults, indicating that hydrothermal fluids in the shallow crust exploit permeable fault zones to circulate. While

  12. Isotopes facilities deactivation project at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Eversole, R.E.

    1997-05-01

    The production and distribution of radioisotopes for medical, scientific, and industrial applications has been a major activity at Oak Ridge National Laboratory (ORNL) since the late 1940s. As the demand for many of these isotopes grew and their sale became profitable, the technology for the production of the isotopes was transferred to private industry, and thus, many of the production facilities at ORNL became underutilized. In 1989, the U.S. Department of Energy (DOE) instructed ORNL to identify and prepare various isotopes production facilities for safe shutdown. In response, ORNL identified 19 candidate facilities for shutdown and established the Isotopes Facilities Shutdown Program. In 1993, responsibility for the program was transitioned from the DOE Office of Nuclear Energy to the DOE Office of Environmental Management and Uranium Enrichment Operation`s Office of Facility Transition and Management. The program was retitled the Isotopes Facilities Deactivation Project (IFDP), and implementation responsibility was transferred from ORNL to the Lockheed Martin Energy Systems, Inc. (LMES), Environmental Restoration (ER) Program.

  13. Isotopes facilities deactivation project at Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Eversole, R.E.

    1997-01-01

    The production and distribution of radioisotopes for medical, scientific, and industrial applications has been a major activity at Oak Ridge National Laboratory (ORNL) since the late 1940s. As the demand for many of these isotopes grew and their sale became profitable, the technology for the production of the isotopes was transferred to private industry, and thus, many of the production facilities at ORNL became underutilized. In 1989, the U.S. Department of Energy (DOE) instructed ORNL to identify and prepare various isotopes production facilities for safe shutdown. In response, ORNL identified 19 candidate facilities for shutdown and established the Isotopes Facilities Shutdown Program. In 1993, responsibility for the program was transitioned from the DOE Office of Nuclear Energy to the DOE Office of Environmental Management and Uranium Enrichment Operation's Office of Facility Transition and Management. The program was retitled the Isotopes Facilities Deactivation Project (IFDP), and implementation responsibility was transferred from ORNL to the Lockheed Martin Energy Systems, Inc. (LMES), Environmental Restoration (ER) Program

  14. Greenland Fracture Zone-East Greenland Ridge(s) revisited: Indications of a C22-change in plate motion?

    DEFF Research Database (Denmark)

    Døssing, Arne; Funck, T.

    2012-01-01

    a reinterpretation of the Greenland Fracture Zone -East Greenland Ridge based on new and existing geophysical data. Evidence is shown for two overstepping ridge segments (Segments A and B) of which Segment A corresponds to the already known East Greenland Ridge while Segment B was not detected previously......Changes in the lithospheric stress field, causing axial rift migration and reorientation of the transform, are generally proposed as an explanation for anomalously old crust and/or major aseismic valleys in oceanic ridge-transform-ridge settings. Similarly, transform migration of the Greenland...... Fracture Zone and separation of the 200-km-long, fracture-zone-parallel continental East Greenland Ridge from the Eurasia plate is thought to be related to a major change in relative plate motions between Greenland and Eurasia during the earliest Oligocene (Chron 13 time). This study presents...

  15. Bird mortality associated with wind turbines at the Buffalo Ridge wind resource area, Minnesota

    Science.gov (United States)

    Osborn, R.G.; Higgins, K.F.; Usgaard, R.E.; Dieter, C.D.; Neiger, R.D.

    2000-01-01

    Recent technological advances have made wind power a viable source of alternative energy production and the number of windplant facilities has increased in the United States. Construction was completed on a 73 turbine, 25 megawatt windplant on Buffalo Ridge near Lake Benton, Minnesota in Spring 1994. The number of birds killed at existing windplants in California caused concern about the potential impacts of the Buffalo Ridge facility on the avian community. From April 1994 through Dec. 1995 we searched the Buffalo Ridge windplant site for dead birds. Additionally, we evaluated search efficiency, predator scavenging rates and rate of carcass decomposition. During 20 mo of monitoring we found 12 dead birds. Collisions with wind turbines were suspected for 8 of the 12 birds. During observer efficiency trials searchers found 78.8% of carcasses. Scavengers removed 39.5% of carcasses during scavenging trials. All carcasses remained recognizable during 7 d decomposition trials. After correction for biases we estimated that approximately 36 ?? 12 birds (bird per turbine) were killed at the Buffalo Ridge windplant in 1 y. Although windplants do not appear to be more detrimental to birds than other man-made structures, proper facility sitting is an important first consideration in order to avoid unnecessary fatalities.

  16. Controls on ferromanganese crust composition and reconnaissance resource potential, Ninetyeast Ridge, Indian Ocean

    Science.gov (United States)

    Hein, James; Conrad, Tracey A.; Mizell, Kira; Banakar, Virupaxa K.; Frey, Frederick A.; Sager, William W.

    2016-01-01

    A reconnaissance survey of Fe-Mn crusts from the 5000 km long (~31°S to 10°N) Ninetyeast Ridge (NER) in the Indian Ocean shows their widespread occurrence along the ridge as well as with water depth on the ridge flanks. The crusts are hydrogenetic based in growth rates and discrimination plots. Twenty samples from 12 crusts from 9 locations along the ridge were analyzed for chemical and mineralogical compositions, growth rates, and statistical relationships (Q-mode factor analysis, correlation coefficients) were calculated. The crusts collected are relatively thin (maximum 40 mm), and those analyzed varied from 4 mm to 32 mm. However, crusts as thick as 80 mm can be expected to occur based on the age of rocks that comprise the NER and the growth rates calculated here. Growth rates of the crusts increase to the north along the NER and with water depth. The increase to the north resulted from an increased supply of Mn from the oxygen minimum zone (OMZ) to depths below the OMZ combined with an increased supply of Fe at depth from the dissolution of biogenic carbonate and from deep-sourced hydrothermal Fe. These increased supplies of Fe increased growth rates of the deeper-water crusts along the entire NER. Because of the huge terrigenous (rivers, eolian, pyroclastic) and hydrothermal (three spreading centers) inputs to the Indian Ocean, and the history of primary productivity, Fe-Mn crust compositions vary from those analyzed from open-ocean locations in the Pacific.

  17. Ridge Orientations of the Ridge-Forming Unit, Sinus Meridiani, Mars-A Fluvial Explanation

    Science.gov (United States)

    Wilkinson, M. Justin; Herridge, A.

    2013-01-01

    Imagery and MOLA data were used in an analysis of the ridge-forming rock unit (RFU) exposed in Sinus Meridiani (SM). This unit shows parallels at different scales with fluvial sedimentary bodies. We propose the terrestrial megafan as the prime analog for the RFU, and likely for other members of the layered units. Megafans are partial cones of fluvial sediment, with radii up to hundreds of km. Although recent reviews of hypotheses for the RFU units exclude fluvial hypotheses [1], inverted ridges in the deserts of Oman have been suggested as putative analogs for some ridges [2], apparently without appreciating The wider context in which these ridges have formed is a series of megafans [3], a relatively unappreciated geomorphic feature. It has been argued that these units conform to the megafan model at the regional, subregional and local scales [4]. At the regional scale suites of terrestrial megafans are known to cover large areas at the foot of uplands on all continents - a close parallel with the setting of the Meridiani sediments at the foot of the southern uplands of Mars, with its incised fluvial systems leading down the regional NW slope [2, 3] towards the sedimentary units. At the subregional scale the layering and internal discontinuities of the Meridiani rocks are consistent, inter alia, with stacked fluvial units [4]. Although poorly recognized as such, the prime geomorphic environment in which stream channel networks cover large areas, without intervening hillslopes, is the megafan [see e.g. 4]. Single megafans can reach 200,000 km2 [5]. Megafans thus supply an analog for areas where channel-like ridges (as a palimpsest of a prior landscape) cover the intercrater plains of Meridiani [6]. At the local, or river-reach scale, the numerous sinuous features of the RFU are suggestive of fluvial channels. Cross-cutting relationships, a common feature of channels on terrestrial megafans, are ubiquitous. Desert megafans show cemented paleo-channels as inverted

  18. US Department of Energy Oak Ridge Operations Environmental Management Public Involvement Plan for the Oak Ridge Reservation

    International Nuclear Information System (INIS)

    1996-03-01

    This document was prepared in accordance with CERCLA requirements for writing community relations plans. It includes information on how the DOE Oak Ridge Operations Office prepares and executes Environmental Management Community relations activities. It is divided into three sections: the public involvement plan, public involvement in Oak Ridge, and public involvement in 1995. Four appendices are also included: environmental management in Oak Ridge; community and regional overview; key laws, agreements, and policy; and principal contacts

  19. Wasteless combined aggregate-coal-fired steam-generator/melting-converter

    International Nuclear Information System (INIS)

    Pioro, L.S.; Pioro, I.L.

    2003-01-01

    A method of reprocessing coal sludge and ash into granulate for the building industry in a combined wasteless aggregate-steam-generator/melting-converter was developed and tested. The method involves melting sludge and ash from coal-fired steam-generators of power plants in a melting-converter installed under the steam-generator, with direct sludge drain from the steam generator combustion chamber. The direct drain of sludge into converter allows burnup of coal with high ash levels in the steam-generator without an additional source of ignition (natural gas, heating oil, etc.). Specific to the melting process is the use of a gas-air mixture with direct combustion inside a melt. This feature provides melt bubbling and helps to achieve maximum heat transfer from combustion products to the melt, to improve mixing, to increase rate of chemical reactions and to improve the conditions for burning the carbon residue from the sludge and ash. The 'gross' thermal efficiency of the combined aggregate is about 93% and the converter capacity is about 18 t of melt in 100 min. The experimental data for different aspects of the proposed method are presented. The effective ash/charging materials feeding system is also discussed. The reprocessed coal ash and sludge in the form of granules can be used as fillers for concretes and as additives in the production of cement, bricks and other building materials

  20. Does presence of a mid-ocean ridge enhance biomass and biodiversity?

    Directory of Open Access Journals (Sweden)

    Imants G Priede

    Full Text Available In contrast to generally sparse biological communities in open-ocean settings, seamounts and ridges are perceived as areas of elevated productivity and biodiversity capable of supporting commercial fisheries. We investigated the origin of this apparent biological enhancement over a segment of the North Mid-Atlantic Ridge (MAR using sonar, corers, trawls, traps, and a remotely operated vehicle to survey habitat, biomass, and biodiversity. Satellite remote sensing provided information on flow patterns, thermal fronts, and primary production, while sediment traps measured export flux during 2007-2010. The MAR, 3,704,404 km(2 in area, accounts for 44.7% lower bathyal habitat (800-3500 m depth in the North Atlantic and is dominated by fine soft sediment substrate (95% of area on a series of flat terraces with intervening slopes either side of the ridge axis contributing to habitat heterogeneity. The MAR fauna comprises mainly species known from continental margins with no evidence of greater biodiversity. Primary production and export flux over the MAR were not enhanced compared with a nearby reference station over the Porcupine Abyssal Plain. Biomasses of benthic macrofauna and megafauna were similar to global averages at the same depths totalling an estimated 258.9 kt C over the entire lower bathyal north MAR. A hypothetical flat plain at 3500 m depth in place of the MAR would contain 85.6 kt C, implying an increase of 173.3 kt C attributable to the presence of the Ridge. This is approximately equal to 167 kt C of estimated pelagic biomass displaced by the volume of the MAR. There is no enhancement of biological productivity over the MAR; oceanic bathypelagic species are replaced by benthic fauna otherwise unable to survive in the mid ocean. We propose that globally sea floor elevation has no effect on deep sea biomass; pelagic plus benthic biomass is constant within a given surface productivity regime.

  1. Analytical study of doubly excited ridge states

    International Nuclear Information System (INIS)

    Wong, H.Y.

    1988-01-01

    Two different non-separable problems are explored and analyzed. Non-perturbative methods need to be used to handle them, as the competing forces involved in these problems are equally strong and do not yield to a perturbative analysis. The first one is the study of doubly excited ridge states of atoms, in which two electrons are comparably excited. An analytical wavefunction for such states is introduced and is used to solve the two-electron Hamiltonian in the pair coordinates called hyperspherical coordinates variationally. The correlation between the electrons is built in analytically into the structure of the wavefunction. Sequences of ridge states out to very high excitation are computed and are organized as Rydberg series converging to the double ionization limit. Numerical results of such states in He and H - are compared with other theoretical calculations where available. The second problem is the analysis of the photodetachment of negative ions in an electric field via the frame transformation theory. The presence of the electron field requires a transformation from spherical to cylindrical symmetry for the outgoing photoelectron. This gives an oscillatory modulating factor as the effect of the electric field on cross-sections. All of this work is derived analytically in a general form applicable to the photodetachment of any negative ion. The expressions are applied to H - and S - for illustration

  2. Oak Ridge National Laboratory Waste Management Plan

    International Nuclear Information System (INIS)

    1991-12-01

    The goal of the Oak Ridge National Laboratory (ORNL) Waste Management Program is the protection of workers, the public, and the environment. A vital aspect of this goal is to comply with all applicable state, federal, and DOE requirements. Waste management requirements for DOE radioactive wastes are detailed in DOE Order 5820.2A, and the ORNL Waste Management Program encompasses all elements of this order. The requirements of this DOE order and other appropriate DOE orders, along with applicable Tennessee Department of Environment and Conservation (TDEC) and US Environmental Protection Agency (EPA) rules and regulations, provide the principal source of regulatory guidance for waste management operations at ORNL. The objective of the Oak Ridge National Laboratory Waste Management Plan is to compile and to consolidate information annually on how the ORNL Waste Management is to compile and to consolidate information annually on how the ORNL Waste Management Program is conducted, which waste management facilities are being used to manage wastes, what forces are acting to change current waste management systems, what activities are planned for the forthcoming fiscal year (FY), and how all of the activities are documented

  3. Tubular Initial Conditions and Ridge Formation

    Directory of Open Access Journals (Sweden)

    M. S. Borysova

    2013-01-01

    Full Text Available The 2D azimuth and rapidity structure of the two-particle correlations in relativistic A+A collisions is altered significantly by the presence of sharp inhomogeneities in superdense matter formed in such processes. The causality constraints enforce one to associate the long-range longitudinal correlations observed in a narrow angular interval, the so-called (soft ridge, with peculiarities of the initial conditions of collision process. This study's objective is to analyze whether multiform initial tubular structures, undergoing the subsequent hydrodynamic evolution and gradual decoupling, can form the soft ridges. Motivated by the flux-tube scenarios, the initial energy density distribution contains the different numbers of high density tube-like boost-invariant inclusions that form a bumpy structure in the transverse plane. The influence of various structures of such initial conditions in the most central A+A events on the collective evolution of matter, resulting spectra, angular particle correlations and vn-coefficients is studied in the framework of the hydrokinetic model (HKM.

  4. Behavior of Cell on Vibrating Micro Ridges

    Directory of Open Access Journals (Sweden)

    Haruka Hino

    2015-06-01

    Full Text Available The effect of micro ridges on cells cultured at a vibrating scaffold has been studied in vitro. Several parallel lines of micro ridges have been made on a disk of transparent polydimethylsiloxane for a scaffold. To apply the vibration on the cultured cells, a piezoelectric element was attached on the outside surface of the bottom of the scaffold. The piezoelectric element was vibrated by the sinusoidal alternating voltage (Vp-p < 16 V at 1.0 MHz generated by a function generator. Four kinds of cells were used in the test: L929 (fibroblast connective tissue of C3H mouse, Hepa1-6 (mouse hepatoma, C2C12 (mouse myoblast, 3T3-L1 (mouse fat precursor cells. The cells were seeded on the micro pattern at the density of 2000 cells/cm2 in the medium containing 10% FBS (fetal bovine serum and 1% penicillin/ streptomycin. After the adhesion of cells in several hours, the cells are exposed to the ultrasonic vibration for several hours. The cells were observed with a phase contrast microscope. The experimental results show that the cells adhere, deform and migrate on the scaffold with micro patterns regardless of the ultrasonic vibration. The effects of the vibration and the micro pattern depend on the kind of cells.

  5. Electron beam melting of sponge titanium

    International Nuclear Information System (INIS)

    Kanayama, Hiroshi; Kusamichi, Tatsuhiko; Muraoka, Tetsuhiro; Onouye, Toshio; Nishimura, Takashi

    1991-01-01

    Fundamental investigations were done on electron beam (EB) melting of sponge titanium by using 80 kW EB melting furnace. Results obtained are as follows: (1) To increase the melting yield of titanium in EB melting of sponge titanium, it is important to recover splashed metal by installation of water-cooled copper wall around the hearth and to decrease evaporation loss of titanium by keeping the surface temperature of molten metal just above the melting temperature of titanium without local heating. (2) Specific power consumption of drip melting of pressed sponge titanium bar and hearth melting of sponge titanium are approximately 0.9 kWh/kg-Ti and 0.5-0.7 kWh/kg-Ti, respectively. (3) Ratios of the heat conducted to water-cooled mould in the drip melting and to water-cooled hearth in the hearth melting to the electron beam input power are 50-65% and 60-65%, respectively. (4) Surface defects of EB-melted ingots include rap which occurs when the EB output is excessively great, and transverse cracks when the EB output is excessively small. To prevent surface defects, the up-down withdrawal method is effective. (author)

  6. Nuclear waste management by in-situ melting

    International Nuclear Information System (INIS)

    Angelo, J.A. Jr.

    1976-01-01

    A systematic assessment of the in-situ melting concept as an ultimate waste disposal option shows that the placement of solidifed, high-level radioactive wastes in an in-situ melting cavity with a crushed rock backfill not only eliminates the major deficiencies inherent in other in-situ melting schemes, but also satisfies reasonable criteria for ultimate disposal. In-situ melting reduces the waste isolation time requirements to several hundred years. Calculated spent fuel and processing waste afterheat values assess the role of actinide and cladding material nuclides in creating the total afterheat and provide quantitative variation with time for these values for contamporary and advanced-design fission reactors. The dominant roles of 134 Cs in thermal spectrum reactor afterheats during the first decade of cooling of the actinide nuclides in all typical waste after-heats following a century or two of cooling are identified. The spatial and temporal behavior of a spherically symmetric waste repository experiencing in-situ melting in an equal density, homogeneous medium for silicate rock and salt is controlled primarily by the overall volumetric thermal source strength, the time-dependent characteristics of the high-level wastes, and the thermophysical properties of the surrounding rock environment. Calculations were verified by experimental data. The hazard index for typical high-level wastes is dominated by the fission product nuclides for the first three centuries of decay. It is then controlled by the actinides, especially americium, which dominates for 10,000 years. With in-situ melting, the hazard index for the re-solidifed rock/waste matrix deepunderground falls below the hazard index of naturally occurring uranium ore bodies within a few hundred years, whether or not the more hazardous actinide nuclides are selectively removed from the wastes prior to storage

  7. Abnormal Winter Melting of the Arctic Sea Ice Cap Observed by the Spaceborne Passive Microwave Sensors

    Directory of Open Access Journals (Sweden)

    Seongsuk Lee

    2016-12-01

    Full Text Available The spatial size and variation of Arctic sea ice play an important role in Earth’s climate system. These are affected by conditions in the polar atmosphere and Arctic sea temperatures. The Arctic sea ice concentration is calculated from brightness temperature data derived from the Defense Meteorological Satellite program (DMSP F13 Special Sensor Microwave/Imagers (SSMI and the DMSP F17 Special Sensor Microwave Imager/Sounder (SSMIS sensors. Many previous studies point to significant reductions in sea ice and their causes. We investigated the variability of Arctic sea ice using the daily and monthly sea ice concentration data from passive microwave observations to identify the sea ice melting regions near the Arctic polar ice cap. We discovered the abnormal melting of the Arctic sea ice near the North Pole even during the summer and the winter. This phenomenon is hard to explain only surface air temperature or solar heating as suggested by recent studies. We propose a hypothesis explaining this phenomenon. The heat from the deep sea in Arctic Ocean ridges and/or the hydrothermal vents might be contributing to the melting of Arctic sea ice. This hypothesis could be verified by the observation of warm water column structure below the melting or thinning arctic sea ice through the project such as Coriolis dataset for reanalysis (CORA.

  8. Mid-ocean ridges produced thicker crust in the Jurassic than in Recent times

    Science.gov (United States)

    Van Avendonk, H. J.; Harding, J.; Davis, J. K.; Lawver, L. A.

    2016-12-01

    We present a compilation of published marine seismic refraction data to show that oceanic crust was 1.7 km thicker on average in the mid-Jurassic (170 Ma) than along the present-day mid-ocean ridge system. Plate reconstructions in a fixed hotspot framework show that the thickness of oceanic crust does not correlate with proximity to mantle hotspots, so it is likely that mid-plate volcanism is not the cause of this global trend. We propose that more melt was extracted from the upper mantle beneath mid-ocean ridges in the Jurassic than in recent times. Numerical studies show that temperature increase of 1 degree C in the mantle can lead to approximately 50-70 m thicker crust, so the upper mantle may have cooled 15-20 degrees C/100 Myr since 170 Ma. This average temperature decrease is larger than the secular cooling rate of the Earth's mantle, which is roughly 10 degrees C/100 Myr since the Archean. Apparently, the present-day configuration and dynamics of continental and oceanic plates removes heat more efficiently from the Earth's mantle than in its earlier history. The increase of ocean crustal thickness with plate age is also stronger in the Indian and Atlantic oceans than in the Pacific Ocean basin. This confirms that thermal insulation by the supercontinent Pangaea raised the temperature of the underlying asthenospheric mantle, which in turn led to more magmatic output at the Jurassic mid-ocean ridges of the Indian and Atlantic oceans.

  9. Geochronology and geochemistry of lavas from the 1996 North Gorda Ridge eruption

    Science.gov (United States)

    Rubin, K. H.; Smith, M. C.; Perfit, M. R.; Christie, D. M.; Sacks, L. F.

    1998-12-01

    Radiometric dating of three North Gorda Ridge lavas by the 210Po- 210Pb method confirms that an eruption occurred during a period of increased seismic activity along the ridge during late February/early March 1996. These lavas were collected following detection of enhanced T-phase seismicity and subsequent ocean bottom photographs documented the existence of a large pillow mound of fresh-appearing lavas. 210Po- 210Pb dating of these lavas indicates that an eruption coinciding with this seismicity did occur (within analytical error) and that followup efforts to sample the recent lava flows were successful. Compositions of the three confirmed young lavas and eleven other samples of this contiguous "new flow" sequence are distinct from older lavas from this area but are variable at a level outside analytical uncertainty. These intraflow variations can not easily be related to a single, common parent magma. Compositional variability within the new flow is compared to that of other recently documented individual flow sequences, and this comparison reveals a strong positive correlation of compositional variance with flow volumes spanning a range of >2 orders of magnitude. The geochemical heterogeneity in the North Gorda new flow probably reflects incomplete mixing of magmas generated from a heterogeneous mantle source or from slightly different melting conditions of a single source. The compositional variability, range in sample ages (up to 6 weeks) and range in active seismicity (4 weeks) imply that this relatively large flow was erupted over an interval of several weeks.

  10. Double melting in polytetrafluoroethylene γ-irradiated above its melting point

    International Nuclear Information System (INIS)

    Serov, S.A.; Khatipov, S.A.; Sadovskaya, N.V.; Tereshenkov, A.V.; Chukov, N.A.

    2012-01-01

    Highlights: ► PTFE irradiation leads to formation of double melting peaks in DSC curves. ► This is connected to dual crystalline morphology typical for PTFE. ► Two crystalline types exist in the PTFE irradiated in the melt. - Abstract: PTFE irradiation above its melting point leads to formation of double melting and crystallization peaks in DSC curves. Splitting of melting peaks is connected to dual crystalline morphology typical for PTFE irradiated in the melt. According to electron microscopy, two crystalline types with different size and packing density exist in the irradiated PTFE.

  11. Tin in granitic melts: The role of melting temperature and protolith composition

    Science.gov (United States)

    Wolf, Mathias; Romer, Rolf L.; Franz, Leander; López-Moro, Francisco Javier

    2018-06-01

    Granite bound tin mineralization typically is seen as the result of extreme magmatic fractionation and late exsolution of magmatic fluids. Mineralization, however, also could be obtained at considerably less fractionation if initial melts already had enhanced Sn contents. We present chemical data and results from phase diagram modeling that illustrate the dominant roles of protolith composition, melting conditions, and melt extraction/evolution for the distribution of Sn between melt and restite and, thus, the Sn content of melts. We compare the element partitioning between leucosome and restite of low-temperature and high-temperature migmatites. During low-temperature melting, trace elements partition preferentially into the restite with the possible exception of Sr, Cd, Bi, and Pb, that may be enriched in the melt. In high-temperature melts, Ga, Y, Cd, Sn, REE, Pb, Bi, and U partition preferentially into the melt whereas Sc, V, Cr, Co, Ni, Mo, and Ba stay in the restite. This contrasting behavior is attributed to the stability of trace element sequestering minerals during melt generation. In particular muscovite, biotite, titanite, and rutile act as host phases for Sn and, therefore prevent Sn enrichment in the melt as long as they are stable phases in the restite. As protolith composition controls both the mineral assemblage and modal contents of the various minerals, protolith composition eventually also controls the fertility of a rock during anatexis, restite mineralogy, and partitioning behavior of trace metals. If a particular trace element is sequestered in a phase that is stable during partial melting, the resulting melt is depleted in this element whereas the restite becomes enriched. Melt generation at high temperature may release Sn when Sn-hosts become unstable. If melt has not been lost before the breakdown of Sn-hosts, Sn contents in the melt will increase but never will be high. In contrast, if melt has been lost before the decomposition of Sn

  12. Chemical decontamination and melt densification

    International Nuclear Information System (INIS)

    Dillon, R.L.; Griggs, B.; Kemper, R.S.; Nelson, R.G.

    1976-01-01

    Preliminary studies on the chemical decontamination and densification of Zircaloy, stainless steel, and Inconel undissolved residues remaining after dissolution of the UO 2 --PuO 2 spent fuel material from sheared fuel bundles are reported. The studies were made on cold or very small samples to demonstrate the feasibility of the processes developed before proceeding to hot cell demonstrations with kg level of the sources. A promising aqueous decontamination method for Zr alloy cladding was developed in which oxidized surfaces are conditioned with HF prior to leaching with ammonium oxalate, ammonium citrate, ammonium fluoride, and hydrogen peroxide. Feasibility of molten salt decontamination of oxidized Zircaloy was demonstrated. A low melting alloy of Zircaloy, stainless steel, and Inconel was obtained in induction heated graphite crucibles. Segregated Zircaloy cladding sections were directly melted by the inductoslag process to yield a metal ingot suitable for storage. Both Zircaloy and Zircaloy--stainless steel--Inconel alloys proved to be highly satisfactory getters and sinks for recovered tritium

  13. Bidirectional optimization of the melting spinning process.

    Science.gov (United States)

    Liang, Xiao; Ding, Yongsheng; Wang, Zidong; Hao, Kuangrong; Hone, Kate; Wang, Huaping

    2014-02-01

    A bidirectional optimizing approach for the melting spinning process based on an immune-enhanced neural network is proposed. The proposed bidirectional model can not only reveal the internal nonlinear relationship between the process configuration and the quality indices of the fibers as final product, but also provide a tool for engineers to develop new fiber products with expected quality specifications. A neural network is taken as the basis for the bidirectional model, and an immune component is introduced to enlarge the searching scope of the solution field so that the neural network has a larger possibility to find the appropriate and reasonable solution, and the error of prediction can therefore be eliminated. The proposed intelligent model can also help to determine what kind of process configuration should be made in order to produce satisfactory fiber products. To make the proposed model practical to the manufacturing, a software platform is developed. Simulation results show that the proposed model can eliminate the approximation error raised by the neural network-based optimizing model, which is due to the extension of focusing scope by the artificial immune mechanism. Meanwhile, the proposed model with the corresponding software can conduct optimization in two directions, namely, the process optimization and category development, and the corresponding results outperform those with an ordinary neural network-based intelligent model. It is also proved that the proposed model has the potential to act as a valuable tool from which the engineers and decision makers of the spinning process could benefit.

  14. Recent massive sulfide deposits of the Semenov ore district, Mid-Atlantic Ridge, 13°31' N: Associated rocks of the oceanic core complex and their hydrothermal alteration

    Science.gov (United States)

    Pertsev, A. N.; Bortnikov, N. S.; Vlasov, E. A.; Beltenev, V. E.; Dobretsova, I. G.; Ageeva, O. A.

    2012-09-01

    The oceanic core complexes and large-offset detachment faults characteristic of the slow-spreading Mid-Atlantic Ridge are crucial for the structural control of large hydrothermal systems, including those forming sub-seafloor polymetallic sulfide mineralization. The structural-geological, petrographic, and mineralogical data are considered for the oceanic core complex enclosing the Semenov-1, -2, -3, -4, and -5 inactive hydrothermal sulfide fields recently discovered on the Mid-Oceanic Ridge at 13°31' N. The oceanic core complex is composed of serpentinized and talc-replaced peridotites and sporadic gabbroic rocks, however, all hydrothermal fields reveal compositional indications of basaltic substrate. The volcanic structures superposed on the oceanic core complex are marked by outcrops of pillow lavas with fresh quenched glass. Dolerites regarded as volcanic conduits seem to represent separate dike swarms. The superposed volcanic structures develop largely along the near-latitudinal high-angle tectonic zone controlling the Semenov-1, -2, -5, and -3 hydrothermal sulfide fields. The manifestations of hydrothermal metasomatic alteration are diverse. The widespread talcose rocks with pyrrhotite-pyrite mineralization after serpentinite, as well as finding of talc-chlorite metabasalt are interpreted as products of hydrothermal activity in the permeable zone of detachment fault. Chloritization and brecciation of basalts with superposed quartz or opal, barite, and pyrite or chalcopyrite mineralization directly related to the sub-seafloor sulfide deposition. The native copper mineralization in almost unaltered basalts at the Semenov-4 field is suggested to precipitate from ore-forming fluids before they reach the level of sub-seafloor sulfide deposition. Amphibolites with plagiogranite veinlets are interpreted as tectonic fragments of the highest-temperature portions of hydrothermal systems, where partial melting of basic rocks in the presence of aqueous fluid with

  15. Multiscale Models of Melting Arctic Sea Ice

    Science.gov (United States)

    2014-09-30

    Sea ice reflectance or albedo , a key parameter in climate modeling, is primarily determined by melt pond and ice floe configurations. Ice - albedo ...determine their albedo - a key parameter in climate modeling. Here we explore the possibility of a conceptual sea ice climate model passing through a...bifurcation points. Ising model for melt ponds on Arctic sea ice Y. Ma, I. Sudakov, and K. M. Golden Abstract: The albedo of melting

  16. a comparative study of some robust ridge and liu estimators

    African Journals Online (AJOL)

    Dr A.B.Ahmed

    estimation techniques such as Ridge and Liu Estimators are preferable to Ordinary Least Square. On the other hand, when outliers exist in the data, robust estimators like M, MM, LTS and S. Estimators, are preferred. To handle these two problems jointly, the study combines the Ridge and Liu Estimators with Robust.

  17. Some Improved Classification-Based Ridge Parameter Of Hoerl And ...

    African Journals Online (AJOL)

    Of Hoerl And Kennard Estimation Techniques. 1Adewale F. Lukmanand 1Kayode Ayinde. 1 Department of Statistics, ... ordinary least square (OLS) in handling it. However, it requires a ridge parameter, K, of which many have ... handle the problem of multicollinearity. They suggested the addition of ridge parameter K to the ...

  18. Effects of ridge and furrow rainfall harvesting system on Elymus ...

    African Journals Online (AJOL)

    ARL

    2012-05-10

    May 10, 2012 ... A ridge-furrow rainfall harvesting system (RFRHS) was designed to increase the available soil water for .... The solar energy passed through the plastic-film and heated up the air and the surface soil of ridge and then the heat was trapped by the greenhouse effect (Zhou et al., 2009). Meanwhile, the.

  19. Nonlinear Forecasting With Many Predictors Using Kernel Ridge Regression

    DEFF Research Database (Denmark)

    Exterkate, Peter; Groenen, Patrick J.F.; Heij, Christiaan

    This paper puts forward kernel ridge regression as an approach for forecasting with many predictors that are related nonlinearly to the target variable. In kernel ridge regression, the observed predictor variables are mapped nonlinearly into a high-dimensional space, where estimation of the predi...

  20. Site characterization of the West Chestnut Ridge site

    International Nuclear Information System (INIS)

    Ketelle, R.H.; Huff, D.D.

    1984-09-01

    This report summarizes the results of investigations performed to date on the West Chestnut Ridge Site, on the Department of Energy (DOE) Oak Ridge Reservation. The investigations performed include geomorphic observations, areal geologic mapping, surficial soil mapping, subsurface investigations, soil geochemical and mineralogical analyses, geohydrologic testing, groundwater fluctuation monitoring, and surface water discharge and precipitation monitoring. 33 references, 32 figures, 24 tables

  1. Oak Ridge Reservation Annual Site environmental report summary for 1994

    International Nuclear Information System (INIS)

    1995-09-01

    This document presents a summary of the information collected for the Oak Ridge Reservation 1994 site environmental report. Topics discussed include: Oak Ridge Reservation mission; ecology; environmental laws; community participation; environmental restoration; waste management; radiation effects; chemical effects; risk to public; environmental monitoring; and radionuclide migration

  2. Clinical management of highly resorbed mandibular ridge without fibrous tissue

    Directory of Open Access Journals (Sweden)

    Veeramalai N Devaki

    2012-01-01

    Full Text Available Alveolar ridge atrophy poses a clinical challenge toward the fabrication of successful prosthesis. Resorption of mandibular denture bearing areas results in unstable non-retentive dentures associated with pain and discomfort. This article describes rehabilitation procedure of a patient with resorbed ridge with maximal areas of coverage to improve support and neutral zone arrangement of teeth to improve stability of denture.

  3. Study on plasma melting treatment of crucibles, ceramic filter elements, asbestos, and fly ash

    International Nuclear Information System (INIS)

    Hoshi, Akiko; Nakasio, Nobuyuki; Nakajima, Mikio

    2004-01-01

    The Japan Atomic Energy Research Institute (JAERI) decided to adopt an advanced volume reduction program for low-level radioactive wastes. In this program, inorganic wastes are converted to stable glassy products suitable for disposal by a plasma melting system in the Waste Volume Reduction Facilities (WVRF). High melting point wastes such as refractories are excluded from the plasma melting treatment in the WVRF, and wastes difficult to handle such as asbestos are also excluded. However, it is describable to apply the plasma melting treatment to these wastes for stabilization and volume reduction from the viewpoint of disposal. In this paper, plasma melting test of crucibles, ceramic filter elements, asbestos, and simulated fly ashes were carried out as a part of technical support for WVRF. The plasma melting treatment was applicable for crucibles and asbestos because homogeneous and glassy products were obtained by controlling of waste and loading condition. It was found that SiC in ceramic filter elements was volatile with a plasma torch with inert gas, and adding reducer was ineffective against stabilizing volatile metals such as Zn, Pb in a solidified product in the melting test of simulated fly ash. (author)

  4. Rapid cooling rates at an active mid-ocean ridge from zircon thermochronology

    Science.gov (United States)

    Schmitt, Axel K.; Perfit, Michael R.; Rubin, Kenneth H.; Stockli, Daniel F.; Smith, Matthew C.; Cotsonika, Laurie A.; Zellmer, Georg F.; Ridley, W. Ian

    2011-01-01

    Oceanic spreading ridges are Earth's most productive crust generating environment, but mechanisms and rates of crustal accretion and heat loss are debated. Existing observations on cooling rates are ambiguous regarding the prevalence of conductive vs. convective cooling of lower oceanic crust. Here, we report the discovery and dating of zircon in mid-ocean ridge dacite lavas that constrain magmatic differentiation and cooling rates at an active spreading center. Dacitic lavas erupted on the southern Cleft segment of the Juan de Fuca ridge, an intermediate-rate spreading center, near the intersection with the Blanco transform fault. Their U–Th zircon crystallization ages (29.3-4.6+4.8 ka; 1δ standard error s.e.) overlap with the (U–Th)/He zircon eruption age (32.7 ± 1.6 ka) within uncertainty. Based on similar 238U-230Th disequilibria between southern Cleft dacite glass separates and young mid-ocean ridge basalt (MORB) erupted nearby, differentiation must have occurred rapidly, within ~ 10–20 ka at most. Ti-in-zircon thermometry indicates crystallization at 850–900 °C and pressures > 70–150 MPa are calculated from H2O solubility models. These time-temperature constraints translate into a magma cooling rate of ~ 2 × 10-2 °C/a. This rate is at least one order-of-magnitude faster than those calculated for zircon-bearing plutonic rocks from slow spreading ridges. Such short intervals for differentiation and cooling can only be resolved through uranium-series (238U–230Th) decay in young lavas, and are best explained by dissipating heat convectively at high crustal permeability.

  5. Arctic Amplification and the Northward shift of a new Greenland melting record

    Science.gov (United States)

    Tedesco, Marco; Mote, Thomas; Fettweis, Xavier; Hanna, Edward; Booth, James; Jeyaratnam, Jeyavinoth; Datta, Rajashree; Briggs, Kate

    2016-04-01

    Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Using reanalysis data and the outputs of a regional climate model, here we show that the persistence of an exceptional atmospheric ridge, centred over the Arctic Ocean was responsible for a northward shift of surface melting records over Greenland, and for increased accumulation in the south during the summer of 2015. Concurrently, new records of mean monthly zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5700±50 m isohypse over the Arctic were also set. An unprecedented (1948 - 2015) and sustained jet stream easterly flow promoted enhanced runoff, increased surface temperatures and decreased albedo in northern Greenland, while inhibiting melting in the south. The exceptional 2015 summer Arctic atmospheric conditions are consistent with the anticipated effects of Arctic Amplification, including slower zonal winds and increased jet stream wave amplitude. Properly addressing the impact of Arctic Amplification on surface runoff of the Greenland ice sheet is crucial for rigorously quantifying its contribution to current and future sea level rise, and the relative impact of freshwater discharge on the surrounding ocean.

  6. Calculation of melting points of oxides

    International Nuclear Information System (INIS)

    Bobkova, O.S.; Voskobojnikov, V.G.; Kozin, A.I.

    1975-01-01

    The correlation between the melting point and thermodynamic parameters characterizing the strength of oxides and compounds is given. Such thermodynamic paramters include the energy and antropy of atomization

  7. On the mean squared error of the ridge estimator of the covariance and precision matrix

    NARCIS (Netherlands)

    van Wieringen, Wessel N.

    2017-01-01

    For a suitably chosen ridge penalty parameter, the ridge regression estimator uniformly dominates the maximum likelihood regression estimator in terms of the mean squared error. Analogous results for the ridge maximum likelihood estimators of covariance and precision matrix are presented.

  8. Crustal structure and tectonics of the Ninetyeast Ridge from seismic and gravity studies

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.; Neprochnov, Y.P.; Rao, D.G.; Grinko, B.N.

    Seismic reflection and refraction, gravity, and bathymetric data across and along the central part of the Ninetyeast Ridge were analyzed to determine the crustal structure of the ridge and to understand its tectonics. The ridge in the study area...

  9. Optical dating of dune ridges on Rømø

    DEFF Research Database (Denmark)

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

    2007-01-01

    The application of optically stimulated luminescence (OSL) to the dating of recent aeolian sand ridges on Rømø, an island off the southwest coast of Denmark, is tested. These sand ridges began to form approximately 300 years ago, and estimates of the ages are available from historical records....... Samples for OSL dating were taken ~0.5 m below the crests of four different dune ridges; at least five samples were recovered from each ridge to test the internal consistency of the ages. Additional samples were recovered from the low lying areas in the swales and from the scattered dune formations......-defined building phases separated by inactive periods and the first major ridge formed ~235 years ago. This study demonstrates that optical dating can be successfully applied to these young aeolian sand deposits, and we conclude that OSL dating is a powerful chronological tool in studies of coastal change....

  10. Papillary fibroelastoma arising from the coumadin ridge

    Directory of Open Access Journals (Sweden)

    Mahim Malik

    2017-06-01

    Full Text Available Cardiac papillary fibroelastomas (CPF are rare cardiac tumors, mostly found on the valvular surfaces in the heart. These tumors are frond like in nature and are benign, intracardiac masses, rarely causing any hemodynamic disturbances. However, excision of these masses is indicated due to their propensity to embolize. We present a case report of the tumor found on the coumadin ridge, causing transient ischemic attacks in a patient. We performed complete excision of the tumor via median sternotomy on cardiopulmonary bypass support with cardiac arrest. The diagnosis was confirmed by histological examination. The patient had an uneventful postoperative course and was discharghed on postoperative day 4. She has had complete resolution of her symptoms post excision. The diagnosis of the mass was confirmed on histological examination.

  11. Oak Ridge Reservation environmental report for 1988

    International Nuclear Information System (INIS)

    Prince, N.L.

    1989-05-01

    The first two volumes of this report are devoted to a presentation of environmental data and supporting narratives for the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and surrounding environs during 1988. Volume 1 includes all narrative descriptions, summaries, and conclusions and is intended to be a ''stand-alone'' report for the ORR for the reader who does not want to review in detail all of the 1988 data. Volume 2 includes the detailed data summarized in a format to ensure that all environmental data are represented in the tables. Narratives are not included in Volume 2. The tables in Volume 2 are addressed in Volume 1. For this reason, Vol. 2 cannot be considered a stand-alone report but is intended to be used in conjunction with Volume 1

  12. Model Selection in Kernel Ridge Regression

    DEFF Research Database (Denmark)

    Exterkate, Peter

    Kernel ridge regression is gaining popularity as a data-rich nonlinear forecasting tool, which is applicable in many different contexts. This paper investigates the influence of the choice of kernel and the setting of tuning parameters on forecast accuracy. We review several popular kernels......, including polynomial kernels, the Gaussian kernel, and the Sinc kernel. We interpret the latter two kernels in terms of their smoothing properties, and we relate the tuning parameters associated to all these kernels to smoothness measures of the prediction function and to the signal-to-noise ratio. Based...... on these interpretations, we provide guidelines for selecting the tuning parameters from small grids using cross-validation. A Monte Carlo study confirms the practical usefulness of these rules of thumb. Finally, the flexible and smooth functional forms provided by the Gaussian and Sinc kernels makes them widely...

  13. Comparative Study on Two Melting Simulation Methods: Melting Curve of Gold

    International Nuclear Information System (INIS)

    Liu Zhong-Li; Li Rui; Sun Jun-Sheng; Zhang Xiu-Lu; Cai Ling-Cang

    2016-01-01

    Melting simulation methods are of crucial importance to determining melting temperature of materials efficiently. A high-efficiency melting simulation method saves much simulation time and computational resources. To compare the efficiency of our newly developed shock melting (SM) method with that of the well-established two-phase (TP) method, we calculate the high-pressure melting curve of Au using the two methods based on the optimally selected interatomic potentials. Although we only use 640 atoms to determine the melting temperature of Au in the SM method, the resulting melting curve accords very well with the results from the TP method using much more atoms. Thus, this shows that a much smaller system size in SM method can still achieve a fully converged melting curve compared with the TP method, implying the robustness and efficiency of the SM method. (paper)

  14. Melton Valley Storage Tanks Capacity Increase Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1995-04-01

    The US Department of Energy (DOE) proposes to construct and maintain additional storage capacity at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee, for liquid low-level radioactive waste (LLLW). New capacity would be provided by a facility partitioned into six individual tank vaults containing one 100,000 gallon LLLW storage tank each. The storage tanks would be located within the existing Melton Valley Storage Tank (MVST) facility. This action would require the extension of a potable water line approximately one mile from the High Flux Isotope Reactor (HFIR) area to the proposed site to provide the necessary potable water for the facility including fire protection. Alternatives considered include no-action, cease generation, storage at other ORR storage facilities, source treatment, pretreatment, and storage at other DOE facilities

  15. Source document for waste area groupings at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Osborne, P.L.; Kuhaida, A.J., Jr.

    1996-09-01

    This document serves as a source document for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and other types of documents developed for and pertaining to Environmental Restoration (ER) Program activities at Oak Ridge National Laboratory (ORNL). It contains descriptions of the (1) regulatory requirements for the ORR ER Program, (2) Oak Ridge Reservation (ORR) ER Program, (3) ORNL site history and characterization, and (4) history and characterization of Waste Area Groupings (WAGS) 1-20. This document was created to save time, effort, and money for persons and organizations drafting documents for the ER Program and to improve consistency in the documents prepared for the program. By eliminating the repetitious use of selected information about the program, this document will help reduce the time and costs associated with producing program documents. By serving as a benchmark for selected information about the ER Program, this reference will help ensure that information presented in future documents is accurate and complete

  16. Oak Ridge Health Studies phase 1 report, Volume 1: Oak Ridge Phase 1 overview

    Energy Technology Data Exchange (ETDEWEB)

    Yarbrough, M.I.; Van Cleave, M.L.; Turri, P.; Daniel, J.

    1993-09-01

    In July 1991, the State of Tennessee initiated the Health Studies Agreement with the United States Department of Energy to carry out independent studies of possible adverse health effects in people living in the vicinity of the Oak Ridge Reservation. The health studies focus on those effects that could have resulted or could result from exposures to chemicals and radioactivity released at the Reservation since 1942. The major focus of the first phase was to complete a Dose Reconstruction Feasibility Study. This study was designed to find out if enough data exist about chemical and radionuclide releases from the Oak Ridge Reservation to conduct a second phase. The second phase will lead to estimates of the actual amounts or the ``doses`` of various contaminants received by people as a result of off-site releases. Once the doses of various contaminants have been estimated, scientists and physicians will be better able to evaluate whether adverse health effects could have resulted from the releases.

  17. Oak Ridge Health Studies phase 1 report, Volume 1: Oak Ridge Phase 1 overview

    International Nuclear Information System (INIS)

    Yarbrough, M.I.; Van Cleave, M.L.; Turri, P.; Daniel, J.

    1993-09-01

    In July 1991, the State of Tennessee initiated the Health Studies Agreement with the United States Department of Energy to carry out independent studies of possible adverse health effects in people living in the vicinity of the Oak Ridge Reservation. The health studies focus on those effects that could have resulted or could result from exposures to chemicals and radioactivity released at the Reservation since 1942. The major focus of the first phase was to complete a Dose Reconstruction Feasibility Study. This study was designed to find out if enough data exist about chemical and radionuclide releases from the Oak Ridge Reservation to conduct a second phase. The second phase will lead to estimates of the actual amounts or the ''doses'' of various contaminants received by people as a result of off-site releases. Once the doses of various contaminants have been estimated, scientists and physicians will be better able to evaluate whether adverse health effects could have resulted from the releases

  18. Developing a Hygrometer for Water-Undersaturated Lherzolite Melts

    Science.gov (United States)

    Guild, M. R.; Till, C. B.

    2017-12-01

    The effect of water on the composition of primitive mantle melts at arc volcanoes is a topic of wide interest and has been addressed in a number of previous experimental studies including Hirose & Kawamoto (1995), Gaetani & Grove (1998), Till et al. (2012) and Mitchell & Grove (2015). The current study builds upon the work by previous authors in an effort to develop a more robust hygrometer for primitive lherzolite melts at water-undersaturated conditions. The starting composition for this experimental study is a mixture of 75% primitive upper mantle and 25% primitive basalt (Baker et al., 1991) with a bulk H2O content of 2 wt. %. Experiments were performed at Arizona State University in the Experimental Petrology and Igneous processes Center (EPIC) from 1.2-1.6 GPa at 1150-1300 ºC for 2 days in a piston cylinder apparatus to reflect conditions relevant for arc melt equilibration (Till 2017). A double capsule design was used to prevent Fe and H2O loss with an inner Fe-presaturated Au80Pd20 capsule and an outer Au80Pd20 capsule. Run products were analyzed by electron microprobe and determined to be successful when they demonstrated 0-5% Fe-loss, olivine-melt KDs of 0.27-0.30, and minimal H2O loss. The water-undersaturated melt composition are in equilibrium with ol+opx+sp±cpx. Run products at 1.6 GPa do not contain cpx in the mineral assemblage over the studied temperature range. Observed melt compositions have SiO2 contents of 48-49 wt. % at 1.2 GPa and 46-49 wt.% at 1.6 GPa. Our experimental results suggest an enhanced effect of water on increasing the SiO2 content of the melt compared to previous studies on systems with similar water contents and anhydrous systems. Baker, et al., JGR 96, 21819-21842 (1991). Gaetani & Grove, CMP 131, 323-346 (1998). Hirose & Kawamoto, EPSL 133, 463-473 (1995). Mitchell & Grove, CMP 170, 13 (2015). Till, Am. Mineral, 102, 931-947 (2017). Till, et al., JGR 117 (2012).

  19. Oak Ridge National Laboratory Technology Logic Diagram

    International Nuclear Information System (INIS)

    1993-09-01

    The Oak Ridge National Laboratory Technology Logic Diagram (TLD) was developed to provide a decision support tool that relates environmental restoration (ER) and waste management (WM) problems at Oak Ridge National Laboratory (ORNL) to potential technologies that can remediate these problems. The TLD identifies the research, development, demonstration testing, and evaluation needed to develop these technologies to a state that allows technology transfer and application to decontamination and decommissioning (D ampersand D), remedial action (RA), and WM activities. The TLD consists of three fundamentally separate volumes: Vol. 1, Technology Evaluation; Vol. 2, Technology Logic Diagram and Vol. 3, Technology EvaLuation Data Sheets. Part A of Vols. 1 and 2 focuses on RA. Part B of Vols. 1 and 2 focuses on the D ampersand D of contaminated facilities. Part C of Vols. 1 and 2 focuses on WM. Each part of Vol. 1 contains an overview of the TM, an explanation of the problems facing the volume-specific program, a review of identified technologies, and rankings of technologies applicable to the site. Volume 2 (Pts. A. B. and C) contains the logic linkages among EM goals, environmental problems, and the various technologies that have the potential to solve these problems. Volume 3 (Pts. A. B, and C) contains the TLD data sheets. This volume provides the technology evaluation data sheets (TEDS) for ER/WM activities (D ampersand D, RA and WM) that are referenced by a TEDS code number in Vol. 2 of the TLD. Each of these sheets represents a single logic trace across the TLD. These sheets contain more detail than is given for the technologies in Vol. 2

  20. Oak Ridge National Laboratory Technology Logic Diagram

    International Nuclear Information System (INIS)

    1993-09-01

    The Oak Ridge National Laboratory Technology Logic Diagram (TLD) was developed to provide a decision-support tool that relates environmental restoration (ER) and waste management (WM) problems at Oak Ridge National Laboratory (ORNL) to potential technologies that can remediate these problems. The TLD identifies the research, development, demonstration, testing, and evaluation needed to develop these technologies to a state that allows technology transfer and application to decontamination and decommissioning (D ampersand D), remedial action (RA), and WM activities. The TLD consists of three fundamentally separate volumes: Vol. 1 (Technology Evaluation), Vol. 2 (Technology Logic Diagram), and Vol. 3 (Technology Evaluation Data Sheets). Part A of Vols. 1 and 2 focuses on D ampersand D. Part B of Vols. 1 and 2 focuses on RA of contaminated facilities. Part C of Vols. 1 and 2 focuses on WM. Each part of Vol. 1 contains an overview of the TLD, an explanation of the program-specific responsibilities, a review of identified technologies, and the ranking os remedial technologies. Volume 2 (Pts. A, B, and C) contains the logic linkages among EM goals, environmental problems, and the various technologies that have the potential to solve these problems. Volume 3 (Pts. A, B, and C) contains the TLD data sheets. The focus of Vol. 1, Pt. B, is RA, and it has been divided into six chapters. The first chapter is an introduction, which defines problems specific to the ER Program for ORNL. Chapter 2 provides a general overview of the TLD. Chapters 3 through 5 are organized into necessary subelement categories: RA, characterization, and robotics and automation. The final chapter contains regulatory compliance information concerning RA

  1. Feasibility of re-melting NORM-contaminated scrap metal

    Energy Technology Data Exchange (ETDEWEB)

    Winters, S. J.; Smith, K. P.

    1999-10-26

    Naturally occurring radioactive materials (NORM) sometimes accumulate inside pieces of equipment associated with oil and gas production and processing activities. Typically, the NORM accumulates when radium that is present in solution in produced water precipitates out in scale and sludge deposits. Scrap equipment containing residual quantities of these NORM-bearing scales and sludges can present a waste management problem if the radium concentrations exceed regulatory limits or activate the alarms on radiation screening devices installed at most scrap metal recycling facilities. Although NORM-contaminated scrap metal currently is not disposed of by re-melting, this form of recycling could present a viable disposition option for this waste stream. Studies indicate that re-melting NORM-contaminated scrap metal is a viable recycling option from a risk-based perspective. However, a myriad of economic, regulatory, and policy issues have caused the recyclers to turn away virtually all radioactive scrap metal. Until these issues can be resolved, re-melting of the petroleum industry's NORM-impacted scrap metal is unlikely to be a widespread practice. This paper summarizes the issues associated with re-melting radioactive scrap so that the petroleum industry and its regulators will understand the obstacles. This paper was prepared as part of a report being prepared by the Interstate Oil and Gas Compact Commission's NORM Subcommittee.

  2. Residence time modeling of hot melt extrusion processes.

    Science.gov (United States)

    Reitz, Elena; Podhaisky, Helmut; Ely, David; Thommes, Markus

    2013-11-01

    The hot melt extrusion process is a widespread technique to mix viscous melts. The residence time of material in the process frequently determines the product properties. An experimental setup and a corresponding mathematical model were developed to evaluate residence time and residence time distribution in twin screw extrusion processes. The extrusion process was modeled as the convolution of a mass transport process described by a Gaussian probability function, and a mixing process represented by an exponential function. The residence time of the extrusion process was determined by introducing a tracer at the extruder inlet and measuring the tracer concentration at the die. These concentrations were fitted to the residence time model, and an adequate correlation was found. Different parameters were derived to characterize the extrusion process including the dead time, the apparent mixing volume, and a transport related axial mixing. A 2(3) design of experiments was performed to evaluate the effect of powder feed rate, screw speed, and melt viscosity of the material on the residence time. All three parameters affect the residence time of material in the extruder. In conclusion, a residence time model was developed to interpret experimental data and to get insights into the hot melt extrusion process. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Hardfacing of duplex stainless steel using melting and diffusion processes

    Science.gov (United States)

    Lailatul, H.; Maleque, M. A.

    2017-03-01

    Duplex stainless steel (DSS) is a material with high potential successes in many new applications such as rail car manufacturing, automotive and chemical industries. Although DSS is widely used in various industries, this material has faced wear and hardness problems which obstruct a wider capability of this material and causes problems in current application. Therefore, development of surface modification has been introduced to produce hard protective layer or coating on DSS. The main aim of this work is to brief review on hard surface layer formation on DSS using melting and diffusion processes. Melting technique using tungsten inert gas (TIG) torch and diffusion technique using gas nitriding are the effective process to meet this requirement. The processing route plays a significant role in developing the hard surface layer for any application with effective cost and environmental factors. The good understanding and careful selection of processing route to form products are very important factors to decide the suitable techniques for surface engineering treatment. In this paper, an attempt is also made to consolidate the important research works done on melting and diffusion techniques of DSS in the past. The advantages and disadvantages between melting and diffusion technique are presented for better understanding on the feasibility of hard surface formation on DSS. Finally, it can be concluded that this work will open an avenue for further research on the application of suitable process for hard surface formation on DSS.

  4. Extending remote sensing estimates of Greenland ice sheet melting

    Science.gov (United States)

    Heavner, M.; Loveland, R.

    2010-12-01

    The Melt Area Detection Index (MADI), a remote sensing algorithm to discriminate between dry and wet snow, has been previously developed and applied to the western portion of the Greenland ice sheet for the years 2000-2006, using Moderate Resolution Imaging Radiospectrometer (MODIS) data (Chylek et al, 2007). We extend that work both spatially and temporally by taking advantage of newly available data, and developing algorithms that facilitate the sensing of cloud cover and the automated inference of wet snow regions. The automated methods allow the development of a composite melt area data product with 0.25 km^2 spatial resolution and approximately two week temporal resolution. We discuss melt area dynamics that are inferred from this high resolution composite melt area. Chylek, P., M. McCabe, M. K. Dubey, and J. Dozier (2007), Remote sensing of Greenland ice sheet using multispectral near-infrared and visible radiances, J. Geophys. Res., 112, D24S20, doi:10.1029/2007JD008742.

  5. Melting metal waste for volume reduction and decontamination

    International Nuclear Information System (INIS)

    Copeland, G.L.; Heshmatpour, B.; Heestand, R.L.

    1980-01-01

    Melt-slagging was investigated as a technique for volume reduction and decontamination of radioactively contaminated scrap metals. Experiments were conducted using several metals and slags in which the partitioning of the contaminant U or Pu to the slag was measured. Concentrations of U or Pu in the metal product of about 1 ppM were achieved for many metals. A volume reduction of 30:1 was achieved for a typical batch of mixed metal scrap. Additionally, the production of granular products was demonstrated with metal shot and crushed slag

  6. Tiger team assessment of the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    none,

    1990-02-01

    This document contains findings identified during the Tiger Team Compliance Assessment of the Department of Energy's (DOE's) Y-12 Plant in Oak Ridge, Tennessee. The Y-12 Plant Tiger Team Compliance Assessment is comprehensive in scope. It covers the Environmental, Safety, and Health (including Occupational Safety and Health Administration (OSHA) compliance), and Management areas and determines the plant's compliance with applicable federal (including DOE), state, and local regulations and requirements. 4 figs., 12 tabs.

  7. Site descriptions of environmental restoration units at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Kuhaida, A.J. Jr.; Parker, A.F.

    1997-02-01

    This report provides summary information on Oak Ridge National Laboratory (ORNL) Environmental Restoration (ER) sites as listed in the Oak Ridge Reservation Federal Facility Agreement (FFA), dated January 1, 1992, Appendix C. The Oak Ridge National Laboratory was built in 1943 as part of the World War II Manhattan Project. The original mission of ORNL was to produce and chemically separate the first gram-quantities of plutonium as part of the national effort to produce the atomic bomb. The current mission of ORNL is to provide applied research and development in support of the U.S. Department of Energy (DOE) programs in nuclear fusion and fission, energy conservation, fossil fuels, and other energy technologies and to perform basic scientific research in selected areas of the physical, life, and environmental sciences. ER is also tasked with clean up or mitigation of environmental impacts resulting from past waste management practices on portions of the approximately 37,000 acres within the Oak Ridge Reservation (ORR). Other installations located within the ORR are the Gaseous Diffusion Plant (K-25) and the Y-12 plant. The remedial action strategy currently integrates state and federal regulations for efficient compliance and approaches for both investigations and remediation efforts on a Waste Area Grouping (WAG) basis. As defined in the ORR FFA Quarterly Report July - September 1995, a WAG is a grouping of potentially contaminated sites based on drainage area and similar waste characteristics. These contaminated sites are further divided into four categories based on existing information concerning whether the data are generated for scoping or remedial investigation (RI) purposes. These areas are as follows: (1) Operable Units (OU); (2) Characterization Areas (CA); (3) Remedial Site Evaluation (RSE) Areas; and (4) Removal Site Evaluation (RmSE) Areas.

  8. The Atlantis Bank Gabbro Massif, SW Indian Ridge: the Largest Know Exposure of the Lower Crust in the Oceans

    Science.gov (United States)

    Dick, H. J.; Kvassnes, A. J.; Kinoshita, H.; MacLeod, C. J.; Robinson, P. T.

    2017-12-01

    Until the discovery of oceanic core complexes little was known and much inferred about the lower ocean crust at slow-spreading ridges. Their study shows the ocean crust isn't simply a uniform layer-cake of pillow lavas, sheeted dikes and gabbros, but is highly variable in thickness, composition and architecture, and even absent over large regions. The 660 km2 Atlantis Bank Gabbro Massif in the rift-mountains of the SW Indian Ridge flanking the Atlantis II Transform is the magmatic end member for ocean core complexes, and best approximates `average' slow-spread crust. Thus it has been a focus for drilling since its discovery in 1986, leading to the current attempt to drill to Moho there (Project SloMo). There are 3 ODP and IODP drill holes on its crest: 1508-m deep Hole 735B, 158-m deep Hole 1105A, and 809.4-m deep Hole U1473. These provide a 200 Kyr view of lower crustal accretion at a slow-spread ocean ridge. Here we extend this view to 2.7 Myr. Mapping and sampling shows the gabbro massif extends nearly the length of a single 2nd order magmatic ridge segment. With numerous inliers of the dike-gabbro transition at numerous locations, and a crust-mantle boundary, traced for 30-km along the transform wall, it would appear to represent a full section of the lower crust. As Moho is at 5.5 ± 1 km mbsf near Hole 735B, and 4.5 km beneath the transform, it is likely a serpentinization front. The crust-mantle boundary was crossed by dives at 4 locations. In each case gabbros at the base of the crust crystallized from melt that had previously fractionated 50% or more from a likely parent. Thus the gabbro massif must be laterally zoned, and the parental mantle melts had to have been emplaced at the center of the paleo-ridge segment, before intruding laterally to the distal end of the complex. Gabbros on a lithospheric flow line down the center of the massif closely resemble those from the drill holes. This shows that while lateral variations in crustal composition and

  9. Modelling of the controlled melt flow in a glass melting space – Its melting performance and heat losses

    Czech Academy of Sciences Publication Activity Database

    Jebavá, Marcela; Dyrčíková, Petra; Němec, Lubomír

    2015-01-01

    Roč. 430, DEC 15 (2015), s. 52-63 ISSN 0022-3093 Institutional support: RVO:67985891 Keywords : glass melt flow * mathematical modelling * energy distribution * space utilizatios * melting performance Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.825, year: 2015

  10. Melting and Sintering of Ashes

    DEFF Research Database (Denmark)

    Hansen, Lone Aslaug

    1997-01-01

    -1300°C, and a trend of higher fusion temperatures with increasing contents of Al-silicates and quartz was found.c) Fly ashes, bottom ashes and deposits from coal/straw co-firing were all found to consist mainly of metal-alumina and alumina-silicates. These ashes all melt in the temperature range 1000......The thesis contains an experimental study of the fusion and sintering of ashes collected during straw and coal/straw co-firing.A laboratory technique for quantitative determination of ash fusion has been developed based on Simultaneous Thermal Analysis (STA). By means of this method the fraction......, the biggest deviations being found for salt rich (i.e. straw derived) ashes.A simple model assuming proportionality between fly ash fusion and deposit formation was found to be capable of ranking deposition rates for the different straw derived fly ashes, whereas for the fly ashes from coal/straw co-firing...

  11. The effect of polycrystalline rod insertion in a low Prandtl number melt for continuous Czochralski system

    Science.gov (United States)

    Nam, Phil-Ouk; Son, Seung-Suk; Yi, Kyung-Woo

    2010-04-01

    The increased wafer size results in greater instabilities and complexities within the silicon melt, and melt flow control through the application of magnetic fields is not adequate to stabilize the melt. Therefore, continuous Czochralski systems are being studied as a solution to these issues, with higher productivity and no change in size. The purpose of this study is to observe the effects of polycrystalline rod insertion on the melt for a continuous Czochralski system. In order to observe flow patterns within the melt both broadly and specifically, we employ experimentation on a model system in tandem with numerical simulation. The rod insertion do not significantly affect near the crystal edge. In the melt height from 0.14 to 0.09 m, an asymmetric temperature distributions arise when the crystal rotation is counterclockwise direction (-15 rpm) and the crucible rotation is clockwise direction (3 rpm). The axis-symmetrical temperature distribution is formed at lower melt heights (0.08 and 0.07 m). When the melt height is 0.07 m, the axis-symmetric temperature distribution is maintained even after the rod insertion.

  12. Eruption style at Kīlauea Volcano in Hawai‘i linked to primary melt composition

    Science.gov (United States)

    Sides. I.R.,; Edmonds, M.; Maclennan, J.; Swanson, Don; Houghton, Bruce F.

    2014-01-01

    Explosive eruptions at basaltic volcanoes have been linked to gas segregation from magmas at shallow depths in the crust. The composition of primary melts formed at greater depths was thought to have little influence on eruptive style. Ocean island basaltic volcanoes are the product of melting of a geochemically heterogeneous mantle plume and are expected to give rise to heterogeneous primary melts. This range in primary melt composition, particularly with respect to the volatile components, will profoundly influence magma buoyancy, storage and eruption style. Here we analyse the geochemistry of a suite of melt inclusions from 25 historical eruptions at the ocean island volcano of Kīlauea, Hawai‘i, over the past 600 years. We find that more explosive styles of eruption at Kīlauea Volcano are associated statistically with more geochemically enriched primary melts that have higher volatile concentrations. These enriched melts ascend faster and retain their primary nature, undergoing little interaction with the magma reservoir at the volcano’s summit. We conclude that the eruption style and magma-supply rate at Kīlauea are fundamentally linked to the geochemistry of the primary melts formed deep below the volcano. Magmas might therefore be predisposed towards explosivity right at the point of formation in their mantle source region.

  13. Melt refining of uranium contaminated copper, nickel, and mild steel

    International Nuclear Information System (INIS)

    Ren Xinwen; Liu Wencang; Zhang Yuan

    1993-01-01

    This paper presents the experiment results on melt refining of uranium contaminated metallic discards such as copper, nickel, and mild steel. Based on recommended processes, uranium contents in ingots shall decrease below 1 ppm; metal recovery is higher than 96%; and slag production is below 5% in weight of the metal to be refined. The uranium in the slag is homogeneously distributed. The slag seems to be hard ceramics, insoluble in water, and can be directly disposed of after proper packaging

  14. Site descriptions of environmental restoration units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Goddard, P.L.; Legeay, A.J.; Pesce, D.S.; Stanley, A.M.

    1995-11-01

    This report, Site Descriptions of Environmental Restoration Units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee, is being prepared to assimilate information on sites included in the Environmental Restoration (ER) Program of the K-25 Site, one of three major installations on the Oak Ridge Reservation (ORR) built during World War III as part of the Manhattan Project. The information included in this report will be used to establish program priorities so that resources allotted to the K-25 ER Program can be best used to decrease any risk to humans or the environment, and to determine the sequence in which any remedial activities should be conducted. This document will be updated periodically in both paper and Internet versions. Units within this report are described in individual data sheets arranged alphanumerically. Each data sheet includes entries on project status, unit location, dimensions and capacity, dates operated, present function, lifecycle operation, waste characteristics, site status, media of concern, comments, and references. Each data sheet is accompanied by a photograph of the unit, and each unit is located on one of 13 area maps. These areas, along with the sub-area, unit, and sub-unit breakdowns within them, are outlined in Appendix A. Appendix B is a summary of information on remote aerial sensing and its applicability to the ER program

  15. Microgravity survey of the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    Kaufmann, R.D.

    1996-05-01

    Karst features are known to exist within the carbonate bedrock of the Oak Ridge K-25 Site and may play an important role in groundwater flow and contaminant migration. This report discusses the results of a microgravity survey of the Oak Ridge K-25 Site. The main objective of the survey is to identify areas containing bedrock cavities. Secondary objectives included correlating the observed gravity to the geology and to variations in overburden thickness. The analysis includes 11 profile lines that are oriented perpendicular to the geologic strike and major structures throughout the K-25 Site. The profile lines are modeled in an effort to relate gravity anomalies to karst features such as concentrations of mud-filled cavities. Regolith thickness and density data provided by boreholes constrain the models. Areally distributed points are added to the profile lines to produce a gravity contour map of the site. In addition, data from the K-901 area are combined with data from previous surveys to produce a high resolution map of that site. The K-25 Site is located in an area of folded and faulted sedimentary rocks within the Appalachian Valley and Ridge physiographic province. Paleozoic age rocks of the Rome Formation, Knox Group, and Chickamauga Supergroup underlie the K-25 Site and contain structures that include the Whiteoak Mountain Fault, the K-25 Fault, a syncline, and an anticline. The mapped locations of the rock units and complex structures are currently derived from outcrop and well log analysis

  16. Site descriptions of environmental restoration units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Goddard, P.L.; Legeay, A.J.; Pesce, D.S.; Stanley, A.M.

    1995-11-01

    This report, Site Descriptions of Environmental Restoration Units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee, is being prepared to assimilate information on sites included in the Environmental Restoration (ER) Program of the K-25 Site, one of three major installations on the Oak Ridge Reservation (ORR) built during World War III as part of the Manhattan Project. The information included in this report will be used to establish program priorities so that resources allotted to the K-25 ER Program can be best used to decrease any risk to humans or the environment, and to determine the sequence in which any remedial activities should be conducted. This document will be updated periodically in both paper and Internet versions. Units within this report are described in individual data sheets arranged alphanumerically. Each data sheet includes entries on project status, unit location, dimensions and capacity, dates operated, present function, lifecycle operation, waste characteristics, site status, media of concern, comments, and references. Each data sheet is accompanied by a photograph of the unit, and each unit is located on one of 13 area maps. These areas, along with the sub-area, unit, and sub-unit breakdowns within them, are outlined in Appendix A. Appendix B is a summary of information on remote aerial sensing and its applicability to the ER program.

  17. Reduced energy consumption for melting in foundries

    Energy Technology Data Exchange (ETDEWEB)

    Skov-Hansen, S.

    2007-09-15

    By improving the gating technology in traditional gating systems it is possible to reduce the amount of metal to be re-melted, and hence reduce the energy consumption for melting in foundries. Traditional gating systems are known for a straight tapered down runner a well base and 90 deg. bends in the runner system. In the streamlined gating systems there are no sharp changes in direction and a large effort is done to confine and control the flow of the molten metal during mould filling. Experiments in real production lines have proven that using streamlined gating systems improves yield by decreasing the poured weight compared to traditional layouts. In a layout for casting of valve housings in a vertically parted mould the weight of the gating system was reduced by 1,1kg which is a 20% weight reduction for the gating system. In a layout for horizontally parted moulds the weight of the gating system has been reduced by 3,7kg which is a weight reduction of 60% for the gating system. The experiments casting valve housings in ductile iron also proved that it is possible to lower the pouring temperature from 1400 deg. C to 1300 deg. C without the risk of cold runs. Glass plate fronted moulds have been used to study the flow of melt during mould filling. These experiments have also been used for studying the flow pattern when ceramic filters are used. The thorough study of the use of filters revealed that the metal passing through the filter is divided into a number of small jets. This proves that filters do not have the claimed positive effect on the flow of metal. The volumes necessary on either side of the filter is not filled till a backpressure is build up and results in formation of pressure shocks when backfilled. These pressure shocks result in more turbulence inside the casting than the same gating system with no filter. Not using filters can mean a reduction in poured weight of 0,6kg. To examine if the experiments using glass plate fronted moulds give

  18. Reaction of soda-lime-silica glass melt with water vapour at melting temperatures

    Czech Academy of Sciences Publication Activity Database

    Vernerová, Miroslava; Kloužek, Jaroslav; Němec, Lubomír

    2015-01-01

    Roč. 416, MAY 15 (2015), s. 21-30 ISSN 0022-3093 R&D Projects: GA TA ČR TA01010844 Institutional support: RVO:67985891 Keywords : glass melt * sulfate * water vapour * bubble nucleation * melt foaming * glass melting Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.825, year: 2015

  19. High-pressure melting curve of KCl: Evidence against lattice-instability theories of melting

    International Nuclear Information System (INIS)

    Ross, M.; Wolf, G.

    1986-01-01

    We show that the large curvature in the T-P melting curve of KCl is the result of a reordering of the liquid to a more densely packed arrangement. As a result theories of melting, such as the instability model, which do not take into account the structure of the liquid fail to predict the correct pressure dependence of the melting curve

  20. 75 FR 19880 - Safety Zone; BW PIONEER at Walker Ridge 249, Outer Continental Shelf FPSO, Gulf of Mexico

    Science.gov (United States)

    2010-04-16

    ... BW PIONEER, a Floating Production, Storage and Offloading (FPSO) system, at Walker Ridge 249 in the Outer Continental Shelf. The purpose of the safety zone is to protect the FPSO from vessels operating... reduces the threat of allisions, oil spills, and releases of natural gas, and thereby protects the safety...

  1. MULTIDISCIPLINARY APPROACH TO STUDY MIGMATITES: ORIGIN AND TECTONIC HISTORY OF THE NASON RIDGE MIGMATITIC GNEISS, WENATCHEE BLOCK, CASCADES CRYSTALLINE CORE, WA, USA

    Directory of Open Access Journals (Sweden)

    Stowell Harold H.

    2008-12-01

    Full Text Available The Nason Ridge Migmatitic Gneiss of the Cascades Core is a migmatitic unit comprising concordant pelitic schist and gneiss, amphibolite, and tonalite gneiss, and cross cutting tonalite, quartz-rich granitoid, and pegmatite. There are several generations of 'igneous' lithologies (leucosomes = tonalite, quartz-rich granitoid, and pegmatite some of which are concordant; others clearly crosscut the strongly deformed host rocks. The host rocks are interpreted to be Chiwaukum Schist with metasedimentary (pelitic schist and some gneiss and metavolcanic(amphibolites origins. Metamorphic fabric in the Nason Ridge Migmatitic Gneiss is characterized by preferred orientation of platy minerals (continuous schistosity, compositional layering, mineral lineations (elongate grains and grain aggregates, and non-coaxial deformational features (asymmetric augen, grain offsets,rotated porphyroblasts, etc.. Compositional layering is characterized by quartz-plagioclase lenses and patches (mm to cm scale and by large variations in biotite content. This composite fabric is faulted and folded by mesoscopic structures. The most strongly foliated leucosomes (gneissic tonalites are generally concordant with the regional trend of foliation, while weakly foliated leucosomes (tonalites and pegmatite veins crosscut host rock and tonalite gneisses. Thin melanosome layers (biotiteand amphibole schist are developed locally around quartz - plagioclase lenses and patches. Metamorphism in the Nason Ridge Migmatitic Gneiss and the nearby Chiwaukum Schist likely peaked after intrusion of the Mt. Stuart Batholith ca. 91-94 Ma. Peak temperatures and pressures for the Nason Ridge Migmatitic Gneiss in the Wenatchee Ridge and Pacific Crest areas were 650 - 720 °C and 6 - 9 kbar with a pressure increase of £ 2.0 kbar during metamorphism. Thermodynamic modeling indicates that hydrous partial melting would begin at ca. 660 °C and is relatively pressure independent. Field

  2. Recent Changes in the Arctic Melt Season

    Science.gov (United States)

    Stroeve, Julienne; Markus, Thorsten; Meier, Walter N.; Miller, Jeff

    2007-01-01

    Melt-season duration, melt-onset and freeze-up dates are derived from satellite passive microwave data and analyzed from 1979 to 2005 over Arctic sea ice. Results indicate a shift towards a longer melt season, particularly north of Alaska and Siberia, corresponding to large retreats of sea ice observed in these regions. Although there is large interannual and regional variability in the length of the melt season, the Arctic is experiencing an overall lengthening of the melt season at a rate of about 2 weeks decade(sup -1). In fact, all regions in the Arctic (except for the central Arctic) have statistically significant (at the 99% level or higher) longer melt seasons by greater than 1 week decade(sup -1). The central Arctic shows a statistically significant trend (at the 98% level) of 5.4 days decade(sup -1). In 2005 the Arctic experienced its longest melt season, corresponding with the least amount of sea ice since 1979 and the warmest temperatures since the 1880s. Overall, the length of the melt season is inversely correlated with the lack of sea ice seen in September north of Alaska and Siberia, with a mean correlation of -0.8.

  3. Attenuation in Melting Layer of Precipitation

    NARCIS (Netherlands)

    Klaassen, W.

    1988-01-01

    A model of the melting layer is employed on radar measurements to simulate the attenuation of radio waves at 12, 20 and 30GHz. The attenuation in the melting layer is simulated to be slightly larger than that of rain with the same path length and precipitation intensity. The result appears to depend

  4. Multiscale approach to equilibrating model polymer melts

    DEFF Research Database (Denmark)

    Svaneborg, Carsten; Ali Karimi-Varzaneh, Hossein; Hojdis, Nils

    2016-01-01

    We present an effective and simple multiscale method for equilibrating Kremer Grest model polymer melts of varying stiffness. In our approach, we progressively equilibrate the melt structure above the tube scale, inside the tube and finally at the monomeric scale. We make use of models designed...

  5. Disordering and Melting of Aluminum Surfaces

    DEFF Research Database (Denmark)

    Stoltze, Per; Nørskov, Jens Kehlet; Landman, U.

    1988-01-01

    We report on a molecular-dynamics simulation of an Al(110) surface using the effective-medium theory to describe the interatomic interactions. The surface region is found to start melting ≅200 K below the bulk melting temperature with a gradual increase in the thickness of the disordered layer as...

  6. Feed Preparation for Source of Alkali Melt Rate Tests

    International Nuclear Information System (INIS)

    Stone, M. E.; Lambert, D. P.

    2005-01-01

    The purpose of the Source of Alkali testing was to prepare feed for melt rate testing in order to determine the maximum melt-rate for a series of batches where the alkali was increased from 0% Na 2 O in the frit (low washed sludge) to 16% Na 2 O in the frit (highly washed sludge). This document summarizes the feed preparation for the Source of Alkali melt rate testing. The Source of Alkali melt rate results will be issued in a separate report. Five batches of Sludge Receipt and Adjustment Tank (SRAT) product and four batches of Slurry Mix Evaporator (SME) product were produced to support Source of Alkali (SOA) melt rate testing. Sludge Batch 3 (SB3) simulant and frit 418 were used as targets for the 8% Na 2 O baseline run. For the other four cases (0% Na 2 O, 4% Na 2 O, 12% Na 2 O, and 16% Na 2 O in frit), special sludge and frit preparations were necessary. The sludge preparations mimicked washing of the SB3 baseline composition, while frit adjustments consisted of increasing or decreasing Na and then re-normalizing the remaining frit components. For all batches, the target glass compositions were identical. The five SRAT products were prepared for testing in the dry fed melt-rate furnace and the four SME products were prepared for the Slurry-fed Melt-Rate Furnace (SMRF). At the same time, the impacts of washing on a baseline composition from a Chemical Process Cell (CPC) perspective could also be investigated. Five process simulations (0% Na 2 O in frit, 4% Na 2 O in frit, 8% Na 2 O in frit or baseline, 12% Na 2 O in frit, and 16% Na 2 O in frit) were completed in three identical 4-L apparatus to produce the five SRAT products. The SRAT products were later dried and combined with the complementary frits to produce identical glass compositions. All five batches were produced with identical processing steps, including off-gas measurement using online gas chromatographs. Two slurry-fed melter feed batches, a 4% Na 2 O in frit run (less washed sludge combined with

  7. Aerodynamic roughness length related to non-aggregated tillage ridges

    Directory of Open Access Journals (Sweden)

    M. Kardous

    2005-11-01

    Full Text Available Wind erosion in agricultural soils is dependent, in part, on the aerodynamic roughness length (z0 produced by tillage ridges. Although previous studies have related z0 to ridge characteristics (ridge height (RH and spacing (RS, these relationships have not been tested for tillage ridges observed in the North African agricultural fields. In these regions, due to climate and soil conditions, small plowing tools are largely used. Most of these tools produce non-aggregated and closely-spaced small ridges. Thus, experiments were conducted in a 7-m long wind tunnel to measure z0 for 11 ridge types covering the range of geometric characteristics frequently observed in south Tunisia. Experimental results suggest that RH2/RS is the first order parameter controlling z0. A strong relationship between z0 and RH2/RS is proposed for a wide range of ridge characteristics.

  8. Hydrodynamic role of longitudinal ridges in a leatherback turtle swimming

    Science.gov (United States)

    Bang, Kyeongtae; Kim, Jooha; Lee, Sang-Im; Choi, Haecheon

    2015-11-01

    The leatherback sea turtle (Dermochelys coriacea), the fastest swimmer and the deepest diver among marine turtles, has five longitudinal ridges on its carapace. These ridges are the most remarkable morphological features distinguished from other marine turtles. To investigate the hydrodynamic role of these ridges in the leatherback turtle swimming, we model a carapace with and without ridges by using three dimensional surface data of a stuffed leatherback turtle in the National Science Museum, Korea. The experiment is conducted in a wind tunnel in the ranges of the real leatherback turtle's Reynolds number (Re) and angle of attack (α). The longitudinal ridges function differently according to the flow condition (i.e. Re and α). At low Re and negative α that represent the swimming condition of hatchlings and juveniles, the ridges significantly decrease the drag by generating streamwise vortices and delaying the main separation. On the other hand, at high Re and positive α that represent the swimming condition of adults, the ridges suppress the laminar separation bubble near the front part by generating streamwise vortices and enhance the lift and lift-to-drag ratio. Supported by the NRF program (2011-0028032).

  9. Shape evolution of a melting nonspherical particle

    Science.gov (United States)

    Kintea, Daniel M.; Hauk, Tobias; Roisman, Ilia V.; Tropea, Cameron

    2015-09-01

    In this study melting of irregular ice crystals was observed in an acoustic levitator. The evolution of the particle shape is captured using a high-speed video system. Several typical phenomena have been discovered: change of the particle shape, appearance of a capillary flow of the melted liquid on the particle surface leading to liquid collection at the particle midsection (where the interface curvature is smallest), and appearance of sharp cusps at the particle tips. No such phenomena can be observed during melting of spherical particles. An approximate theoretical model is developed which accounts for the main physical phenomena associated with melting of an irregular particle. The agreement between the theoretical predictions for the melting time, for the evolution of the particle shape, and the corresponding experimental data is rather good.

  10. Nanotexturing of surfaces to reduce melting point.

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Ernest J.; Zubia, David (University of Texas at El Paso El Paso, TX); Mireles, Jose (Universidad Aut%C3%94onoma de Ciudad Ju%C3%94arez Ciudad Ju%C3%94arez, Mexico); Marquez, Noel (University of Texas at El Paso El Paso, TX); Quinones, Stella (University of Texas at El Paso El Paso, TX)

    2011-11-01

    This investigation examined the use of nano-patterned structures on Silicon-on-Insulator (SOI) material to reduce the bulk material melting point (1414 C). It has been found that sharp-tipped and other similar structures have a propensity to move to the lower energy states of spherical structures and as a result exhibit lower melting points than the bulk material. Such a reduction of the melting point would offer a number of interesting opportunities for bonding in microsystems packaging applications. Nano patterning process capabilities were developed to create the required structures for the investigation. One of the technical challenges of the project was understanding and creating the specialized conditions required to observe the melting and reshaping phenomena. Through systematic experimentation and review of the literature these conditions were determined and used to conduct phase change experiments. Melting temperatures as low as 1030 C were observed.

  11. Melting Can Hinder Impact-Induced Adhesion

    Science.gov (United States)

    Hassani-Gangaraj, Mostafa; Veysset, David; Nelson, Keith A.; Schuh, Christopher A.

    2017-10-01

    Melting has long been used to join metallic materials, from welding to selective laser melting in additive manufacturing. In the same school of thought, localized melting has been generally perceived as an advantage, if not the main mechanism, for the adhesion of metallic microparticles to substrates during a supersonic impact. Here, we conduct the first in situ supersonic impact observations of individual metallic microparticles aimed at the explicit study of melting effects. Counterintuitively, we find that under at least some conditions melting is disadvantageous and hinders impact-induced adhesion. In the parameter space explored, i.e., ˜10 μ m particle size and ˜1 km /s particle velocity, we argue that the solidification time is much longer than the residence time of the particle on the substrate, so that resolidification cannot be a significant factor in adhesion.

  12. Modeling the summertim