Analytical-Numerical Modeling Of Komatiite Lava Emplacement And...
Modeling Of Komatiite Lava Emplacement And Thermal Erosion At Perseverance, Western Australia Jump to: navigation, search OpenEI Reference LibraryAdd to library...
Ehrlich, S.A.; Douglass, D.L.
1982-06-01T23:59:59.000Z
The compatibility of several binary and ternary alloys in a magma environment was studied. Binary alloys containing molybdenum and ternary alloys containing chromium and molybdenum were exposed to basaltic lava at 1150/sup 0/C for periods of 24 and 96 hours. A cover gas was used to produce oxygen and sulfur fugacities corresponding to those of the gases dissolved in basaltic melts. Three base metals were used. These included iron, nickel, and cobalt. The primary reactions in binary alloys were found to be sulfidation. Oxide scales with a spinel layer formed on ternary alloys. The synergistic effect of molybdenum and chromium additions in ternary alloys exhibited superior corrosion resistance to binary alloys which formed base-metal sulfides down grain-boundaries. Extensive analyses of the reaction products by scanning electron microscopy, X-ray energy dispersive analysis, electron microprobe analysis, and metallography are presented for each alloys. The products formed are discussed with reference to thermodynamic stability diagrams, and the reaction path concept is used to explain some of the corrosion.
Bennecke, W.M.
1996-10-01T23:59:59.000Z
A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an idealized basalt lava flow model was generated that used a set of nomenclature that would be standard for the basalt lava flows studied. An upper vesicular zone, a sometimes absent columnar zone, central zone, and lower vesicular zone make up the basalt lava flow model. The overall distinction between the different zones are based on the vesicle shape size, vesicularity, and fractures present. The results of the studies also indicated that the basalt lava flows at the INEL are distal to medial facies pahoehoe lava flows with close fitting contacts. The most permeable zones identified in these basalts are fractured vesiculated portions of the top of the lava flow, the columnar areas, and basalt-flow contacts in order of importance. This was determined from impeller flowmeter logging at the INEL. Having this information a detailed stratigraphy of individual basalt lava flows and the corresponding permeable units were generated. From this it was concluded that groundwater flow at the ICPP prefers to travel along thin basalt lava flows or flow-units. Flow direction and velocity of intrawell flows detected by flowmeter is controlled by a nearby pumping well.
JOURNAL OF PETROLOGY VOLUME 39 NUMBER 1 PAGES 125154 1998 Chemical and Isotopic Composition of Lavas
Stern, Robert J.
of the Mariana Trough extension axis. The source, reflecting the arc-like nature of the source region and isotopic compositions of igneous rocks the mantle. `True' back-arc basin basalts are generated upwelling in mature ex-basalts in the south which become increasingly similar to arc lavas tensional
Poreda, Robert J.
. It remains in the public domain. 91 Geochemical Discrimination of Five Pleistocene Lava-Dam Outburst- Flood@usgs.gov) A B S T R A C T Pleistocene basaltic lava dams and outburst-flood deposits in the western Grand Canyon outburst-flood deposit came from a common source, a lava dam. With these data, it is possible
Lithium isotopes in global mid-ocean ridge basalts Paul B. Tomascak a,*, Charles H. Langmuir b
Langmuir, Charles H.
Lithium isotopes in global mid-ocean ridge basalts Paul B. Tomascak a,*, Charles H. Langmuir b January 2008 Abstract The lithium isotope compositions of 30 well-characterized samples of glassy lavas
Pressure grouting of fractured basalt flows
Shaw, P.; Weidner, J.; Phillips, S.; Alexander, J.
1996-04-01T23:59:59.000Z
This report describes a field trial of pressure grouting in basalt and the results of subsequent coring and permeability measurement activities. The objective was to show that the hydraulic conductivity of fractured basalt bedrock can be significantly reduced by pressure injection of cementitious materials. The effectiveness of the pressure grout procedure was evaluated by measuring the change in the hydraulic conductivity of the bedrock. The extent of grout penetration was established by analyzing postgrout injection drilling chips for the presence of a tracer in the grout and also by examining cores of the treated basalt. Downhole radar mapping was used to establish major lava flow patterns and follow water movement during a surface infiltration test. A site called Box Canyon, which is located northwest of the INEL, was chosen for this study due to the similarity of this surface outcrop geology to that of the underlying bedrock fracture system found at the Radioactive Waste Management Complex. This study showed that hydraulic conductivity of basalt can be reduced through pressure grouting of cementitious material.
Wells, S. [Univ. of California, Riverside, CA (United States). Dept. of Earth Sciences; McFadden, L.; Perry, F. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Geology; Forman, S. [Ohio State Univ., Columbus, OH (United States). Byrd Polar Research Center; Crowe, B.; Pothis, J.; Olinger, C. [Los Alamos National Lab., NM (United States)
1992-12-31T23:59:59.000Z
Evaluation of volcanic hazards near the proposed high-level radioactive waste repository at Yucca Mountain provides the impetus for a series of detailed field and geochronologic studies of selected small late Quaternary basaltic scoria cones and lava flows in Nevada and California. Two of the most significant results of these studies are: the presence of chronostratigraphic units which indicate multiple eruptions with significant intervals of no activity between events (polycyclic volcanism); and a marked difference between conventional, numerical ages derived from K-Ar and Ar-40/Ar-39 methods and numerical, calibrated, and relative ages derived from thermoluminescence, cosmogenic He-3, the degree of soil development, and geomorphology of these volcanic landforms. Soil-bounded unconformities and buried stone pavements define the boundaries of chronostratigraphic units within these small volume basaltic centers. Volcanic centers displaying this type of stratigraphy may appear morphological simple but cannot be considered mongenetic. Recent studies by Perry and Crowe demonstrate that geochemical variations within a single basaltic volcanic center in NV are consistent with several magma batches forming a complex polycyclic volcano. The K-Ar and Ar-40/Ar-39 ages are 1--2 orders of magnitude older than either TL or cosmogenic He-3 and appear to have insufficient precision to constrain the ages of chronostratigraphic units within polycyclic volcanoes. In contrast, preliminary data indicate the TL and cosmogenic He-3 dating methods have the ability to resolve the late Quaternary volcanic stratigraphy, and results from these dating methods are consistent with the degree of soil development and geomorphic modification of the volcanic units. K-Ar and Ar-40/Ar-39 dates from these small basaltic volcanic centers have been used to calibrate new Quaternary dating methods, e.g. rock varnish, which in turn have been used to interpret landscape evolution in the SW US.
Reidel, S.P. (Washington State Univ., Pullman (United States)); Tolan, T.L. (Portland State Univ., OR (United States))
1992-12-01T23:59:59.000Z
Flows of the Teepee Butte Member, Grande Ronde Basalt, issued from a vent system in southeastern Washington, northeastern Oregon, and western Idaho. Three distinct basalt flows were erupted: the Limekiln Rapids flow, the Joseph Creek flow, and the Pruitt Draw flow. Together these mappable flows cover more than 52,000 km[sup 2] and have a volume exceeding 5,000 km[sup 3]. A portion of the vent system for the Joseph Creek flow is exposed in cross section in Joseph Canyon, Washington; it is one of the best preserved Columbia River Basalt Group vent complexes known. The vent complex is about 1 km in cross section, 30 m high, and composed of deposits characteristic of Hawaiian-type volcanism. The vent is asymmetrical; the eastern rampart consists of intercalated pyroclastic deposits and thin pahoehoe flows; the western rampart is composed wholly of pahoehoe flows. Flows of the Teepee Butte Member are compositionally homogeneous and were emplaced as sheet flows, each having several local flow units. Our study supports the importance of linear vent systems and the westward Palouse Slope, along with the large-volume lava flows, in controlling the distribution of Columbia River Basalt Group flows. Other factors, including the number of active fissure segments and topography, modified the shape of the flows and the number of flow units. 45 refs., 19 figs., 2 tabs.
Decreasing Magmatic Footprints of Individual Volcanos in a Waning Basaltic Field
G.A> Valentine; F.V. Perry
2006-06-06T23:59:59.000Z
The distribution and characteristics of individual basaltic volcanoes in the waning Southwestern Nevada Volcanic Field provide insight into the changing physical nature of magmatism and the controls on volcano location. During Pliocene-Pleistocene times the volumes of individual volcanoes have decreased by more than one order of magnitude, as have fissure lengths and inferred lava effusion rates. Eruptions evolved from Hawaiian-style eruptions with extensive lavas to eruptions characterized by small pulses of lava and Strombolian to violent Strombolian mechanisms. These trends indicate progressively decreasing partial melting and length scales, or magmatic footprints, of mantle source zones for individual volcanoes. The location of each volcano is determined by the location of its magmatic footprint at depth, and only by shallow structural and topographic features that are within that footprint. The locations of future volcanoes in a waning system are less likely to be determined by large-scale topography or structures than were older, larger volume volcanoes.
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G.A. Valentine; F.V. Perry; D. Krier; G.N. Keating; R.E. Kelley; A.H. Cogbill
2006-04-04T23:59:59.000Z
Five Pleistocene basaltic volcanoes in Crater Flat (southern Nevada) demonstrate the complexity of eruption processes associated with small-volume basalts and the effects of initial emplacement characteristics on post-eruptive geomorphic evolution of the volcanic surfaces. The volcanoes record eruptive processes in their pyroclastic facies ranging from ''classical'' Strombolian mechanisms to, potentially, violent Strombolian mechanisms. Cone growth was accompanied, and sometimes disrupted, by effusion of lavas from the bases of cones. Pyroclastic cones were built upon a gently southward-sloping surface and were prone to failure of their down-slope (southern) flanks. Early lavas flowed primarily southward and, at Red and Black Cone volcanoes, carried abundant rafts of cone material on the tops of the flows. These resulting early lava fields eventually built platforms such that later flows erupted from the eastern (at Red Cone) and northern (at Black Cone) bases of the cones. Three major surface features--scoria cones, lava fields with abundant rafts of pyroclastic material, and lava fields with little or no pyroclastic material--experienced different post-eruptive surficial processes. Contrary to previous interpretations, we argue that the Pleistocene Crater Flat volcanoes are monogenetic, each having formed in a single eruptive episode lasting months to a few years, and with all eruptive products having emanated from the area of the volcanoes main cones rather than from scattered vents. Geochemical variations within the volcanoes must be interpreted within a monogenetic framework, which implies preservation of magma source heterogeneities through ascent and eruption of the magmas.
Smith, S.T.; Lim, J.J.; Phillips, J.R.; Tisinger, R.M.; Brown, D.C.; FitzGerald, P.D.
1986-01-01T23:59:59.000Z
At Los Alamos National Laboratory, we have developed an original methodology for performing risk analyses on subject systems characterized by a general set of asset categories, a general spectrum of threats, a definable system-specific set of safeguards protecting the assets from the threats, and a general set of outcomes resulting from threats exploiting weaknesses in the safeguards system. The Los Alamos Vulnerability and Risk Assessment Methodology (LAVA) models complex systems having large amounts of ''soft'' information about both the system itself and occurrences related to the system. Its structure lends itself well to automation on a portable computer, making it possible to analyze numerous similar but geographically separated installations consistently and in as much depth as the subject system warrants. LAVA is based on hierarchical systems theory, event trees, fuzzy sets, natural-language processing, decision theory, and utility theory. LAVA's framework is a hierarchical set of fuzzy event trees that relate the results of several embedded (or sub-) analyses: a vulnerability assessment providing information about the presence and efficacy of system safeguards, a threat analysis providing information about static (background) and dynamic (changing) threat components coupled with an analysis of asset ''attractiveness'' to the dynamic threat, and a consequence analysis providing information about the outcome spectrum's severity measures and impact values. By using LAVA, we have modeled our widely used computer security application as well as LAVA/CS systems for physical protection, transborder data flow, contract awards, and property management. It is presently being applied for modeling risk management in embedded systems, survivability systems, and weapons systems security. LAVA is especially effective in modeling subject systems that include a large human component.
Cooling of Kilauea Iki lava lake
Hills, R.G.
1982-02-01T23:59:59.000Z
In 1959 Kilauea Iki erupted leaving a 110 to 120 m lake of molten lava in its crater. The resulting lava lake has provided a unique opportunity to study the cooling dynamics of a molten body and its associated hydrothermal system. Field measurements taken at Kilauea Iki indicate that the hydrothermal system above the cooling magma body goes through several stages, some of which are well modeled analytically. Field measurements also indicate that during most of the solidification period of the lake, cooling from above is controlled by 2-phase convection while conduction dominates the cooling of the lake from below. A summary of the field work related to the study of the cooling dynamics of Kilauea Iki is presented. Quantitative and qualitative cooling models for the lake are discussed.
Analytical-Numerical Modeling Of Komatiite Lava Emplacement And Thermal
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Subduction Controls of Hf and Nd Isotopes in Lavas of the Aleutian Island Arc
Yogodzinski, Gene; Vervoort, Jeffery; Brown, Shaun Tyler; Gerseny, Megan
2010-08-29T23:59:59.000Z
The Hf and Nd isotopic compositions of 71 Quaternary lavas collected from locations along the full length of the Aleutian island arc are used to constrain the sources of Aleutian magmas and to provide insight into the geochemical behavior of Nd and Hf and related elements in the Aleutian subduction-magmatic system. Isotopic compositions of Aleutian lavas fall approximately at the center of, and form a trend parallel to, the terrestrial Hf-Nd isotopic array with {var_epsilon}{sub Hf} of +12.0 to +15.5 and {var_epsilon}{sub Nd} of +6.5 to +10.5. Basalts, andesites, and dacites within volcanic centers or in nearby volcanoes generally all have similar isotopic compositions, indicating that there is little measurable effect of crustal or other lithospheric assimilation within the volcanic plumbing systems of Aleutian volcanoes. Hafnium isotopic compositions have a clear pattern of along-arc increase that is continuous from the eastern-most locations near Cold Bay to Piip Seamount in the western-most part of the arc. This pattern is interpreted to reflect a westward decrease in the subducted sediment component present in Aleutian lavas, reflecting progressively lower rates of subduction westward as well as decreasing availability of trench sediment. Binary bulk mixing models (sediment + peridotite) demonstrate that 1-2% of the Hf in Aleutian lavas is derived from subducted sediment, indicating that Hf is mobilized out of the subducted sediment with an efficiency that is similar to that of Sr, Pb and Nd. Low published solubility for Hf and Nd in aqueous subduction fluids lead us to conclude that these elements are mobilized out of the subducted component and transferred to the mantle wedge as bulk sediment or as a silicate melt. Neodymium isotopes also generally increase from east to west, but the pattern is absent in the eastern third of the arc, where the sediment flux is high and increases from east to west, due to the presence of abundant terrigenous sediment in the trench east of the Amlia Fracture Zone, which is being subducting beneath the arc at Seguam Island. Mixing trends between mantle wedge and sediment end members become flatter in Hf-Nd isotope space at locations further west along the arc, indicating that the sediment end member in the west has either higher Nd/Hf or is more radiogenic in Hf compared to Nd. This pattern is interpreted to reflect an increase in pelagic clay relative to the terrigenous subducted sedimentary component westward along the arc. Results of this study imply that Hf does not behave as a conservative element in the Aleutian subduction system, as has been proposed for some other arcs.
Seismic Structure And Seismicity Of The Cooling Lava Lake Of...
Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Seismic Structure And Seismicity Of The Cooling Lava Lake Of Kilauea Iki, Hawaii Abstract The...
The Influence of Basalt Layers on Seismic Wave Propagation
Hanssen, Peter
are to examine the effects of basalts on seismic wave propagation and the concequent implications for imaging sedimentary structures beneath them. From studies of basalt propertiesand borehole data in connection with foreward modelling and real data, I show...
Aciego, S.M.; Jourdan, F.; DePaolo, D.J.; Kennedy, B.M.; Renne, P.R.; Sims, K.W.W.
2009-10-01T23:59:59.000Z
Late Quaternary, post-shield lavas from the Mauna Kea and Kohala volcanoes on the Big Island of Hawaii have been dated using the {sup 40}Ar/{sup 39}Ar and U-Th/He methods. The objective of the study is to compare the recently demonstrated U-Th/He age method, which uses basaltic olivine phenocrysts, with {sup 40}Ar/{sup 39}Ar ages measured on groundmass from the same samples. As a corollary, the age data also increase the precision of the chronology of volcanism on the Big Island. For the U-Th/He ages, U, Th and He concentrations and isotopes were measured to account for U-series disequilibrium and initial He. Single analyses U-Th/He ages for Hamakua lavas from Mauna Kea are 87 {+-} 40 ka to 119 {+-} 23 ka (2{sigma} uncertainties), which are in general equal to or younger than {sup 40}Ar/{sup 39}Ar ages. Basalt from the Polulu sequence on Kohala gives a U-Th/He age of 354 {+-} 54 ka and a {sup 40}Ar/{sup 39}Ar age of 450 {+-} 40 ka. All of the U-Th/He ages, and all but one spurious {sup 40}Ar/{sup 39}Ar ages conform to the previously proposed stratigraphy and published {sup 14}C and K-Ar ages. The ages also compare favorably to U-Th whole rock-olivine ages calculated from {sup 238}U - {sup 230}Th disequilibria. The U-Th/He and {sup 40}Ar/{sup 39}Ar results agree best where there is a relatively large amount of radiogenic {sup 40}Ar (>10%), and where the {sup 40}Ar/{sup 36}Ar intercept calculated from the Ar isochron diagram is close to the atmospheric value. In two cases, it is not clear why U-Th/He and {sup 40}Ar/{sup 39}Ar ages do not agree within uncertainty. U-Th/He and {sup 40}Ar/{sup 39}Ar results diverge the most on a low-K transitional tholeiitic basalt with abundant olivine. For the most alkalic basalts with negligible olivine phenocrysts, U-Th/He ages were unattainable while {sup 40}Ar/{sup 39}Ar results provide good precision even on ages as low as 19 {+-} 4 ka. Hence, the strengths and weaknesses of the U-Th/He and {sup 40}Ar/{sup 39}Ar methods are complimentary for basalts with ages of order 100-500 ka.
Karlsson, Brynjar
. It is known that basalt fibers have better tensile strength than E-glass fibers, greater failure strain than mention Compar model o fibres re time in regions failure o the mat then tak FRP com The use type is s function which m is anoth was des by dam has been of beam In colum column where om environ ned as conti red
Pederson, Neil
Site name: Khorgo Lava Pine, Mongolia Collectors: A. Hessl, N. Pederson Empire, and modern Mongolia. Proceedings of the National Academy of Science collected in 2010 and 2012 across the Khorgo lava field near Tariat, Mongolia
Numerical Integration Numerical Summation
Cohen, Henri
Numerical Integration Numerical Summation Numerical Extrapolation Numerical Recipes for Multiprecision Computations #12;Numerical Integration Numerical Summation Numerical Extrapolation Multiprecision, integration, summation, extrapolation, evaluation of continued fractions, Euler products and sums, complete
Basics of lava-lamp convection Balzs Gyre1
Jánosi, Imre M.
marketed only since the sixties 1 . The most essential ingredients are two immis- cible fluids of densities function, the lava lamp has been used also as visual aid in geoscience courses 2 demonstrat- ing phenomena such as the transformation of energy, force and motion, adiabatic circulations in the atmosphere and oceans, or magma
Physical Constraints on Geologic CO2 Sequestration in Low-Volume Basalt Formations
Ryan M. Pollyea; Jerry P. Fairley; Robert K. Podgorney; Travis L. McLing
2014-03-01T23:59:59.000Z
Deep basalt formations within large igneous provinces have been proposed as target reservoirs for carbon capture and sequestration on the basis of favorable CO2-water-rock reaction kinetics that suggest carbonate mineralization rates on the order of 102–103 d. Although these results are encouraging, there exists much uncertainty surrounding the influence of fracture-controlled reservoir heterogeneity on commercial-scale CO2 injections in basalt formations. This work investigates the physical response of a low-volume basalt reservoir to commercial-scale CO2 injections using a Monte Carlo numerical modeling experiment such that model variability is solely a function of spatially distributed reservoir heterogeneity. Fifty equally probable reservoirs are simulated using properties inferred from the deep eastern Snake River Plain aquifer in southeast Idaho, and CO2 injections are modeled within each reservoir for 20 yr at a constant mass rate of 21.6 kg s–1. Results from this work suggest that (1) formation injectivity is generally favorable, although injection pressures in excess of the fracture gradient were observed in 4% of the simulations; (2) for an extensional stress regime (as exists within the eastern Snake River Plain), shear failure is theoretically possible for optimally oriented fractures if Sh is less than or equal to 0.70SV; and (3) low-volume basalt reservoirs exhibit sufficient CO2 confinement potential over a 20 yr injection program to accommodate mineral trapping rates suggested in the literature.
Graham, David W.
Discussion Helium isotopes in historical lavas from Mount Vesuvius Comment on `Noble gas isotopic. Introduction Helium isotope results recently published by Tedesco et al. [1] appear to show a decrease in 3 He. Results Helium isotope results from our laboratory are reported in Table 1. The 3 He/4 He ratio has been
A Primitive Alkali Basaltic Stratovolcano And Associated Eruptive...
Significance Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Primitive Alkali Basaltic Stratovolcano And Associated Eruptive Centres,...
Paces, J.B. (Michigan Technological Univ., Houghton (USA)); Bell, K. (Carleton Univ., Ottawa, Ontario (Canada))
1989-08-01T23:59:59.000Z
Midcontinent Rift flood basalts represent a sample of the relatively shallow, sub-continental upper mantle beneath the Canadian Shield at 1.1 Ga. A thick sequence of olivine tholeiite lavas, including minor intermediate to rhyolitic lavas, from the Portage Lake Volcanics (PLV) in northern Michigan have initial Nd and Sr isotopic compositions which cluster near Bulk Earth values. The effects of assimilation of old LREE-enriched continental crust into mantle-derived fractionating liquids are isotopically discernible in evolved lavas as well as in olivine tholeiites from the lowest portion of the volcanic pile. However, the effects of crustal contamination decrease with stratigraphic height and are absent in more primitive lavas in the upper half of the section. The source for PLV tholeiites is substantially less depleted than previously reported mantle values from the Superior Province. An origin for the PLV source is compatible with either of several mantle evolution models. The PLV source may have been associated with upwelling of a LIL element-enriched, asthenospheric plume which emplaced non-depleted material from deeper sources into the shallow sub-continental mantle beneath the Midcontinent Rift during continental break-up. Alternatively, the PLV source may have originated by enrichment of refractory sub-continental lithospheric mantle which was previously depleted in incompatible trace elements during Archean-aged melt extraction and continental crust formation. Concurrent generation of carbonatite magmas in other areas beneath the Superior Province indicates the widespread presence of sub-continental mantle with substantially higher {epsilon}{sub Nd}(T) and lower {epsilon}{sub Sr}(T) than the PLV source.
Germanium abundances in lunar basalts: Evidence of mantle metasomatism
Dickinson, T.; Taylor, G.J.; Keil, T.K.; Bild, R.W.
1988-01-01T23:59:59.000Z
To fill in gaps in the present Ge data base, mare basalts were analyzed for Ge and other elements by RNAA and INAA. Mare basalts from Apollo 11, 12, 15, 17 landing sites are rather uniform in Ge abundance, but Apollo 14 aluminous mare basalts and KREEP are enriched in Ge by factors of up to 300 compared to typical mare basalts. These Ge enrichments are not associated with other siderophile element enrichments and, thus, are not due to differences in the amount of metal segregated during core formation. Based on crystal-chemical and inter-element variations, it does not appear that the observed Ge enrichments are due to silicate liquid immiscibility. Elemental ratios in Apollo 14 aluminous mare basalts, green and orange glass, average basalts and KREEP suggest that incorporation of late accreting material into the source regions or interaction of the magmas with primitive undifferentiated material is not a likely cause for the observed Ge enrichments. We speculate that the most plausible explanation for these Ge enrichments is complexing and concentration of Ge by F, Cl or S in volatile phases. In this manner, the KREEP basalt source regions may have been metasomatized and Apollo 14 aluminous mare basalt magmas may have become enriched in Ge by interacting with these metasomatized areas. The presence of volatile- and Ge-rich regions in the Moon suggests that the Moon was never totally molten. 71 refs., 1 fig., 6 tabs.
Consequences of melt transport for uranium series disequilibrium in young lavas
Spiegelman, Marc W.
Consequences of melt transport for uranium series disequilibrium in young lavas Marc Spiegelman do not actu- ally include melt transport. Here we explore the be- haviour of short
Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA
Received 6 May 2005 Availble online 7 February 2006 Abstract The failure of a lava dam 165,000 yr ago dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. FailurePeak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA Cassandra R
Initial advance of long lava flows in open channels Daisuke Takagi, Herbert E. Huppert
Huppert, Herbert
cooling-limited when it reaches a maximum length attainable for a given supply of lava from the vent to cooling become important. Theoretical results are applied to the study of long lava flows that descended the dynamic properties of the bulk flow. In contrast, effects due to cooling played a major role throughout
Cooling rate of some active lavas determined using an orbital imaging spectrometer
Wright, Robert
Click Here for Full Article Cooling rate of some active lavas determined using an orbital imaging flow is an important physical property to measure. Through its influence on lava crystallinity, cooling modeling problem that will aid in the analysis of data acquired by future hyperspectral remote sensing
Plio-Pleistocene time-averaged field in southern Patagonia recorded in lava flows
Singer, Bradley S.
Plio-Pleistocene time-averaged field in southern Patagonia recorded in lava flows V. Mejia and N. D of 53 lava flows from southern Patagonia (latitudes 49.5Â°Â52.1Â°S) that include the Pali-Aike volcanic, 7 figures, 3 tables. Keywords: paleomagnetic secular variation; Patagonia; Pali-Aike Volcanic Field
Breakthroughs in Seismic and Borehole Characterization of Basalt Sequestration Targets
Sullivan, E. C.; Hardage, Bob A.; McGrail, B. Peter; Davis, Klarissa N.
2011-04-01T23:59:59.000Z
Mafic continental flood basalts form a globally important, but under-characterized CO2 sequestration target. The Columbia River Basalt Group (CRBG) in the northwestern U.S. is up to 5 km thick and covers over 168,000 km2. In India, flood basalts are 3 km thick and cover greater than 500,000 km2. Laboratory experiments demonstrate that the CRBG and other basalts react with formation water and super critical (sc) CO2 to precipitate carbonates, thus adding a potential mineral trapping mechanism to the standard trapping mechanisms of most other types of CO2 sequestration reservoirs. Brecciated tops of individual basalt flows in the CRBG form regional aquifers that locally have greater than 30% porosity and three Darcies of permeability. Porous flow tops are potential sites for sequestration of gigatons of scCO2 in areas where the basalts contain unpotable water and are at depths greater than 800 m. In this paper we report on the U.S. DOE Big Sky Regional Carbon Sequestration Partnership surface seismic and borehole geophysical characterization that supports a field test of capacity, integrity, and geochemical reactivity of CRBG reservoirs in eastern Washington, U.S.A. Traditional surface seismic methods have had little success in imaging basalt features in on-shore areas where the basalt is thinly covered by sediment. Processing of the experimental 6.5 km, 5 line 3C seismic swath included constructing an elastic wavefield model, identifying and separating seismic wave modes, and processing the swath as a single 2D line. Important findings include: (1) a wide variety of shear wave energy modes swamp the P-wave seismic records; (2) except at very short geophone offsets, ground roll overprints P-wave signal; and (3) because of extreme velocity contrasts, P-wave events are refracted at incidence angles greater than 7-15 degrees. Subsequent removal of S-wave and other noise during processing resulted in tremendous improvement in image quality. The application of wireline logging to onshore basalts is underexploited. Full waveform sonic logs and resistivity-based image logs acquired in the 1250 m basalt pilot borehole provide powerful tools for evaluating geomechanics and lithofacies. The azimuth of the fast shear wave is parallel to SH and records the changes through time in basalt flow and tectonic stress tensors. Combined with image log data, azimuthal S-wave data provide a borehole technique for assessing basalt emplacement and cooling history that is related to the development of reservoirs and seals, as well as the orientation of tectonic stresses and fracture systems that could affect CO2 transport or containment. Reservoir and seal properties are controlled by basalt lithofacies, and rescaled P- and S- wave slowness curves, integrated with image logs, provide a tool for improved recognition of subsurface lithofacies.
Preliminary Hydrogeologic Characterization Results from the Wallula Basalt Pilot Study
B.P. McGrail; E. C. Sullivan; F. A. Spane; D. H. Bacon; G. Hund; P. D. Thorne; C. J. Thompson; S. P. Reidel; F. S. Colwell
2009-12-01T23:59:59.000Z
The DOE's Big Sky Regional Carbon Sequestration Partnership has completed drilling the first continental flood basalt sequestration pilot borehole to a total depth (TD) of 4,110 feet on the Boise White Paper Mill property at Wallula, Washington. Site suitability was assessed prior to drilling by the 2007-2008 acquisition, processing and analysis of a four-mile, five-line three component seismic swath, which was processed as a single data-dense line. Analysis of the seismic survey data indicated a composite basalt formation thickness of {approx}8,000 feet and absence of major geologic structures (i.e., faults) along the line imaged by the seismic swath. Drilling of Wallula pilot borehole was initiated on January 13, 2009 and reached TD on April 6, 2009. Based on characterization results obtained during drilling, three basalt breccia zones were identified between the depth interval of 2,716 and 2,910 feet, as being suitable injection reservoir for a subsequent CO2 injection pilot study. The targeted injection reservoir lies stratigraphically below the massive Umtanum Member of the Grande Ronde Basalt, whose flow-interior section possesses regionally recognized low-permeability characteristics. The identified composite injection zone reservoir provides a unique and attractive opportunity to scientifically study the reservoir behavior of three inter-connected reservoir intervals below primary and secondary caprock confining zones. Drill cuttings, wireline geophysical logs, and 31one-inch diameter rotary sidewall cores provided geologic data for characterization of rock properties. XRF analyses of selected rock samples provided geochemical characterizations of the rocks and stratigraphic control for the basalt flows encountered by the Wallula pilot borehole. Based on the geochemical results, the pilot borehole was terminated in the Wapshilla Ridge 1 flow of the Grande Ronde Basalt Formation. Detailed hydrologic test characterizations of 12 basalt interflow reservoir zones and 3 flow-interior/caprock intervals were performed during drilling and immediately following reaching the final borehole drilling depth (i.e., 4,110 ft). In addition, six of the 12 basalt interflow zones were selected for detailed hydrochemical characterization. Results from the detailed hydrologic test characterization program provided the primary information on basalt interflow zone transmissivity/injectivity, and caprock permeability characteristics.
Simulating infiltration tests in fractured basalt at the Box Canyon Site, Idaho
Unger, Andre J.A.; Faybishenko, Boris; Bodvarsson, Gudmundur S.; Simmons, Ardyth M.
2003-04-01T23:59:59.000Z
The results of a series of ponded infiltration tests in variably saturated fractured basalt at Box Canyon, Idaho, were used to build confidence in conceptual and numerical modeling approaches used to simulate infiltration in fractured rock. Specifically, we constructed a dual-permeability model using TOUGH2 to represent both the matrix and fracture continua of the upper basalt flow at the Box Canyon site. A consistent set of hydrogeological parameters was obtained by calibrating the model to infiltration front arrival times in the fracture continuum as inferred from bromide samples collected from fracture/borehole intersections observed during the infiltrating tests. These parameters included the permeability of the fracture and matrix continua, the interfacial area between the fracture and matrix continua, and the porosity of the fracture continuum. To calibrate the model, we multiplied the fracture-matrix interfacial area by a factor between 0.1 and 0.01 to reduce imbibition of water from the fracture continuum into the matrix continuum during the infiltration tests. Furthermore, the porosity of the fracture continuum, as calculated using the fracture aperture inferred from pneumatic-test permeabilities, was increased by a factor of 50 yielding porosity values for the upper basalt flow in the range of 0.01 to 0.02. The fracture-continuum porosity was a highly sensitive parameter controlling the arrival times of the simulated infiltration fronts. Porosity values are consistent with those determined during the Large-Scale Aquifer Pumping and Infiltration Test at the Idaho National Engineering and Environmental Laboratory.
Origin of enriched ocean ridge basalts and implications for mantle dynamics
Langmuir, Charles H.
Origin of enriched ocean ridge basalts and implications for mantle dynamics Kathleen E. Donnellya that a small proportion of basalt are enriched in incompatible elements (enriched mid-ocean ridge basalts, E-MORB) from the MARK area. It is apparent that enriched magma sources, not associated with hot spots
Tuesday, March 14, 2006 POSTER SESSION I: LUNAR BASALTIC VOLCANISM
Rathbun, Julie A.
Africa 003-A is a 124 g new lunar meteorite (low-Ti mare basalt) found in northern Libya in the wadi Zam lithology of a new, 124 g lunar meteorite Northeast Africa 003 found in northern Libya in the wadi Zam Zam
Singer, Bradley S.
Ar/Ar ages from transitionally magnetized lavas on La Palma, Canary Islands, and the geomagnetic the north and south walls of Barranco de los Tilos on the island of La Palma, Canary Islands, reveals from transitionally magnetized lavas on La Palma, Canary Islands, and the geomagnetic instability
Cervantes, Pablo
1999-01-01T23:59:59.000Z
Melt inclusions in olivine phenocrysts from primitive lavas from five different volcanoes in the Sierra Chichinautzin (Central Mexico) were analyzed by infrared spectroscopy and electron microprobe to determine their major ...
Wright, Robert
Using infrared satellite data to drive a thermo-rheological/stochastic lava flow emplacement model the downhill paths that a lava flow could possibly follow and a thermorheological model to terminate, and A. J. L. Harris (2008), Using infrared satellite data to drive a thermo-rheological/stochastic lava
Short communication Origins and implications of zigzag rift patterns on lava lakes
Manga, Michael
the zigzags. Similar patterns are observed in analog wax experiments in which molten wax acts as cooling and solidifying lava. We perform a series of these wax experiments to find the relationship between , A of spreading and solidification speeds; the amplitude A is limited by the thickness of the solid wax crust
Smith, M.J.
1980-05-01T23:59:59.000Z
This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed.
Ilmenite exsolution schemes in Apollo-17 high-Ti basalts
Vaniman, D.; Heiken, G. (Los Alamos National Lab., NM (USA)); Muhich, T. (College of St. Thomas, St. Paul, MN (USA). Dept. of Geology)
1990-01-01T23:59:59.000Z
Combined electron microprobe and scanning electron microscope (SEM) x-ray image analyses are used to obtain semiquantitative data on the relations between ilmenite grains and their exsolved chromite and rutile. Comparisons of these data for ilmenites in four Apollo-17 high-Ti basalts with a database of electron microprobe analyses from the literature indicates that Cr expulsion from ilmenite can be as important as Fe{sup 2+} reduction in causing subsolidus exsolution of chromite and rutile from ilmenite. 12 refs., 4 figs., 5 tabs.
Suckale, Jenny
2011-01-01T23:59:59.000Z
Multiphase flows are an essential component of natural systems: They affect the explosivity of volcanic eruptions, shape the landscape of terrestrial planets, and govern subsurface flow in hydrocarbon reservoirs. Advancing ...
Flood and Shield Basalts from Ethiopia: Magmas from the African Superswell
Demouchy, Sylvie
Flood and Shield Basalts from Ethiopia: Magmas from the African Superswell BRUNO KIEFFER1, ETHIOPIA 4 DEEPARTEMENT DES SCIENCES DE LA TERRE ET DE L'ENVIRONNEMENT, UNIVERSITEE LIBRE DE BRUXELLES 50 the shield volcanoes. KEY WORDS: Ethiopia; flood basalts; shield volcanism; superswell INTRODUCTION According
Vallino, Joseph J.
Effects of Biochar and Basalt Additions on Carbon Sequestration and Fluxes of Greenhouse Gases Emissions--Carbon Dioxide Emissions--Sequestration and Storage--Biochar--Basalt--Organic Fertilizers, this investigation focuses on the range of potential of different soil additives to enhance sequestration and storage
Mason, Olivia U.; Di Meo-Savoie, Carol A.; Van Nostrand, Joy D.; Zhou, Jizhong; Fisk, Martin R.; Giovannoni, Stephen J.
2008-09-30T23:59:59.000Z
We used molecular techniques to analyze basalts of varying ages that were collected from the East Pacific Rise, 9 oN, from the rift axis of the Juan de Fuca Ridge, and from neighboring seamounts. Cluster analysis of 16S rDNA Terminal Restriction Fragment Polymorphism data revealed that basalt endoliths are distinct from seawater and that communities clustered, to some degree, based on the age of the host rock. This age-based clustering suggests that alteration processes may affect community structure. Cloning and sequencing of bacterial and archaeal 16S rRNA genes revealed twelve different phyla and sub-phyla associated with basalts. These include the Gemmatimonadetes, Nitrospirae, the candidate phylum SBR1093 in the c, andin the Archaea Marine Benthic Group B, none of which have been previously reported in basalts. We delineated novel ocean crust clades in the gamma-Proteobacteria, Planctomycetes, and Actinobacteria that are composed entirely of basalt associated microflora, and may represent basalt ecotypes. Finally, microarray analysis of functional genes in basalt revealed that genes coding for previously unreported processes such as carbon fixation, methane-oxidation, methanogenesis, and nitrogen fixation are present, suggesting that basalts harbor previously unrecognized metabolic diversity. These novel processes could exert a profound influence on ocean chemistry.
Perfect, Ed
Uraniumlead systematics of low-Ti basaltic meteorite Dhofar 287A: Affinity to Apollo 15 green as the crystallization age of Dho 287A, is similar to crystallization ages of Apollo 15 low-Ti olivine-normative basalts different from the reported -values of 300 for mare basalts from the Apollo collections, including
Basalt petrogenesis beneath slow- and ultraslow-spreading Arctic mid-ocean ridges
Elkins, Lynne J
2009-01-01T23:59:59.000Z
To explore the ability of melting mafic lithologies to produce alkaline ocean-island basalts (OIB), an experimental study was carried out measuring clinopyroxene (Cpx)melt and garnet (Gt)-melt partition coefficients during ...
Petrology of some oceanic island basalts: PRIMELT2.XLS software for primary magma calculation
Petrology of some oceanic island basalts: PRIMELT2.XLS software for primary magma calculation C potential temperature; primary magma. Index Terms: 3621 Mineralogy and Petrology: Mantle processes (1038); 3610 Mineralogy and Petrology: Geochemical modeling (1009, 8410); 3630 Mineralogy and Petrology
Siebel, Wolfgang
Petrogenesis of the Linxi granitoids, northern Inner Mongolia of China: Constraints on basaltic in the Linxi area, northern Inner Mongolia of China, divided into two suites, are mainly granodiorite growth; Granitoid petrogenesis; Northern Inner Mongolia 1. Introduction Phanerozoic granitoids
Jackson, Matthew G. (Matthew Gerald)
2008-01-01T23:59:59.000Z
Chapter 1 presents the first published measurements of Sr-isotope variability in olivine-hosted melt inclusions. Melt inclusions in just two Samoan basalt hand samples exhibit most of the total Sr-isotope variability ...
Nakata, Dorene Samantha
2010-01-01T23:59:59.000Z
Mid-ocean ridge basalts (MORBs) exhibit a wide range of CO2 concentrations, reflecting saturation to supersaturation (and rarely undersaturation) relative to their emplacement depths. In this study, we explore the mechanisms ...
Paris-Sud XI, Université de
-829 MOSSBAUER STUDIES OF ICELANDIC LAVAS 0. HELGASON, S. STEINTHORSSON Science Institute, University of Iceland ktudiks par la spectroscopie Mossbauer. On a trouvk qu'une haute vitesse de solidification cause un plus. Abstract. - Two samples of lava from Iceland have been studied by use of Mossbauer spec- troscopy
Reidel, Steve P.; Spane, Frank A.; Johnson, Vernon G.
2002-08-08T23:59:59.000Z
This report provides the technical background and a guide to characterizing a site for storing natural gas in the Columbia River Basalt
Hausrath, E.M.
2008-01-01T23:59:59.000Z
Basalt weathering rates on Earth and the duration of liquidCarlisle, PA 17013 Earth Sciences Division, Lawrencetime to liquid water: on Earth, mineral persistence times
Bindeman, Ilya N.
and compositional zoning in selected grains, and subtle to severe D18 O (melt-olivine) and D18 O (plagioclase isotope laser fluorination analyses of 55 individual and bulk olivine crystals, coexisting individual different lavas, and variable core-to-rim oxygen isotopic zoning is present in selected olivine grains. Many
Preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt
Taylor, C.L.; O'Rourke, J.E.; Allirot, D.; O'Connor, K.
1980-09-01T23:59:59.000Z
This report presents results of a study leading to preconceptual designs for plugging boreholes, shafts, and tunnels to a nuclear waste repository in basalt. Beginning design criteria include a list of preferred plug materials and plugging machines that were selected to suit the environmental conditions, and depths, diameters, and orientations of the accesses to a nuclear waste repository in the Columbia River basalts located in eastern Washington State. The environmental conditions are described. The fiscal year 1979-1980 Task II work is presented in two parts: preliminary testing of materials for plugging of man-made accesses to a repository in basalt (described in a separate report); and preconceptual systems and equipment for plugging of man-made accesses to a repository in basalt (described in this report). To fulfill the scope of the Task II work, Woodward-Clyde Consultants (WCC) was requested to: provide preconceptual systems for plugging boreholes, tunnels, and shafts in basalt; describe preconceptual borehole plugging equipment for placing the selected materials in man-made accesses; utilize the quality assurance program, program plan and schedule, and work plans previously developed for Task II; and prepare a preliminary report.
Spane, F.A. Jr.; Webber, W.D.
1995-09-01T23:59:59.000Z
As part of the Hanford Site Ground-Water Surveillance Project, Flow System Characterization Task. Pacific Northwest Laboratory examines the potential for offsite migration of contamination within the upper basalt confined aquifer system for the US Department of Energy (DOE). As part of this activity, groundwater samples were collected over the past 2 years from selected wells completed in the upper Saddle Mountains Basalt. The hydrochemical and isotopic information obtained from these groundwater samples provides hydrologic information concerning the aquifer-flow system. Ideally, when combined with other hydrologic property information, hydrochemical and isotopic data can be used to evaluate the origin and source of groundwater, areal groundwater-flow patterns, residence and groundwater travel time, rock/groundwater reactions, and aquifer intercommunication for the upper basalt confined aquifer system. This report presents the first comprehensive Hanford Site-wide summary of hydrochemical properties for the upper basalt confined aquifer system. This report provides the hydrogeologic characteristics (Section 2.0) and hydrochemical properties (Section 3.0) for groundwater within this system. A detailed description of the range of the identified hydrochemical parameter subgroups for groundwater in the upper basalt confined aquifer system is also presented in Section 3.0. Evidence that is indicative of aquifer contamination/aquifer intercommunication and an assessment of the potential for offsite migration of contaminants in groundwater within the upper basalt aquifer is provided in Section 4.0. The references cited throughout the report are given in Section 5.0. Tables that summarize groundwater sample analysis results for individual test interval/well sites are included in the Appendix.
Basalt waste isolation project. Quarterly report, October 1, 1980-December 31, 1980
Deju, R.A.
1981-02-01T23:59:59.000Z
In September 1977, the National Waste Terminal Storage Program was restructured to support investigations of two US DOE sites - Hanford and Nevada. The Basalt Waste Isolation Project within Rockwell Hanford Operations has been chartered with the responsibility of conducting these investigations. The overall Basalt Waste Isolation Project is divided into the following principal work areas: systems integration, geosciences, hydrology, engineered barriers, near-surface test facility, engineering testing, and repository studies. Summaries of major accomplishments for each of these areas are reported in this document.
Utrecht, Universiteit
Palaeomagnetism of flood basalts in the Pilbara Craton, Western Australia: Late Archaean in the Nullagine Synclinorium (and Meentheena Centrocline) of the East Pilbara Basin, Western Australia, has been. Langereis, Palaeomagnetism of flood basalts in the Pilbara Craton, Western Australia: Late Archaean
Taylor, Lawrence A.
THE MOST REDUCED ROCK FROM THE MOON Â APOLLO 14 BASALT 14053: EXTREME REDUCTION ENTIRELY FROM A RE: With the return of the Apollo 14 rocks and soil, the Preliminary Examination Team reported that the majority] speculated that the hi-Al Apollo 14 basalts actually had an impact-melt origin. Likewise, unique reduction
Taylor, Lawrence A.
NEW INSIGHTS INTO THE ORIGIN OF 14053 Â THE ONLY BASALTIC ROCK RETURNED BY APOLLO 14. Rhiannon G of Geological Sciences, University of Tennessee, Knoxville, Tennessee, 37996. Introduction: The Apollo 14 to the hy- pothesis that 14053 and other Apollo 14 hi-Al basalts actually had an impact-melt origin
Aciego, S.M.
2010-01-01T23:59:59.000Z
to Mineralogy and Petrology 84(4), 390-405. Frey F. A. ,to Mineralogy and Petrology 100, 383-397. Williams A.J. ,series lavas. Journal of Petrology 38(7), 911-939. Dunai T.
Flow of Volatile-Free and Volatile-Rich Basaltic Magmas through Elastic-Walled Dikes
Al Hanbali, Ahmad
averaged in "one-dimensional" flow tube. #12;Questions: · Can we obtain a simple 1D symmetric model) · Anisotropy 1 in horizontal and vertical rock stress #12;Elastic flow equations · Continuity equation t(m bFlow of Volatile-Free and Volatile-Rich Basaltic Magmas through Elastic-Walled Dikes O. Bokhove
Mineralization of Basalts in the CO2-H2O-H2S System. | EMSL
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
HT, BP McGrail, AT Owen, and BW Arey.2013."Mineralization of Basalts in the CO2-H2O-H2S System."International Journal of Greenhouse Gas Control 16:187-196. doi:10.1016...
Generation of CO2-rich melts during basalt magma ascent and degassing
Boyer, Edmond
to solubilities. In contrast, the rate of vesiculation controls the final melt CO2 concentration. HighGeneration of CO2-rich melts during basalt magma ascent and degassing Michel Pichavant . Ida Di magma degassing, continuous decompressions of volatile-bearing (2.7-3.8 wt% H2O, 600-1300 ppm CO2
The carbon dioxide solubility in alkali basalts: an experimental PRISCILLE LESNE 1,*
Paris-Sud XI, Université de
1 The carbon dioxide solubility in alkali basalts: an experimental study PRISCILLE LESNE 1 in both fluid and melt is required since, because of its low solubility, carbon dioxide is usually a major in silicate melts dramatically influence the physical properties of magmas, such as density, viscosity
Temperatures in ambient mantle and plumes: Constraints from basalts, picrites, and komatiites
below oceanic ridges, islands, and plateaus, on the basis of the petrology and geochemistry of erupted plumes; ambient mantle temperatures; petrology; mid ocean ridge basalt. Index Terms: 3610 Mineralogy and Petrology: Geochemical modeling (1009, 8410); 3619 Mineralogy and Petrology: Magma genesis and partial
Use of low frequencies for sub-basalt imaging Anton Ziolkowski,1
Edinburgh, University of
, Murchison House, West Mains Road, Edinburgh EH9 3LA, 3 Veritas DGC Limited, Crompton Way, Manor Royal Estate14 4HA, UK Received June 2002, revision accepted August 2002 ABSTRACT Many prospective passive ocean of passive ocean margins are covered by basalts, which are often opaque to conventional seismic reflection
Brandt, C.A.; Rickard, W.H. Jr.; Biehert, R.W.; Newell, R.L.; Page, T.L.
1989-01-01T23:59:59.000Z
The Basalt Waste Isolation Project (BWIP) was undertaken to environmentally characterize a portion of the US Department of Energy's Hanford Site in Washington State as a potential host for the nation's first mined commercial nuclear waste repository. Studies were terminated by Congress in 1987. Between 1976 and 1987, 72 areas located across the Hanford Site were disturbed by the BWIP. These areas include borehole pads, a large Exploratory Shaft Facility, and the Near Surface Test Facility. Most boreholes were cleared of vegetation, leveled, and stabilized with a thick layer of compacted pit-run gravel and sand. The Near Surface Test Facility consists of three mined adits, a rock-spoils bench, and numerous support facilities. Restoration began in 1988 with the objective of returning sites to pre-existing conditions using native species. The Hanford Site retains some of the last remnants of the shrub-steppe ecosystem in Washington. The primary constraints to restoring native vegetation at Hanford are low precipitation and the presence of cheatgrass, an extremely capable alien competitor. 5 figs.
Zakharova, Natalia V.; Goldberg, David S.; Sullivan, E. C.; Herron, Michael M.; Grau, Jim A.
2012-11-02T23:59:59.000Z
Abstract This study presents borehole geophysical data and sidewall core chemistry from the Wallula Pilot Sequestration Project in the Columbia River flood basalt. The wireline logging data were reprocessed, core-calibrated and interpreted in the framework of reservoir and seal characterization for carbon dioxide storage. Particular attention is paid to the capabilities and limitations of borehole spectroscopy for chemical characterization of basalt. Neutron capture spectroscopy logging is shown to provide accurate concentrations for up to 8 major and minor elements but has limited sensitivity to natural alteration in fresh-water basaltic reservoirs. The Wallula borehole intersected 26 flows from 7 members of the Grande Ronde formation. The logging data demonstrate a cyclic pattern of sequential basalt flows with alternating porous flow tops (potential reservoirs) and massive flow interiors (potential caprock). The log-derived apparent porosity is extremely high in the flow tops (20%-45%), and considerably overestimates effective porosity obtained from hydraulic testing. The flow interiors are characterized by low apparent porosity (0-8%) but appear pervasively fractured in borehole images. Electrical resistivity images show diverse volcanic textures and provide an excellent tool for fracture analysis, but neither fracture density nor log-derived porosity uniquely correlate with hydraulic properties of the Grande Ronde formation. While porous flow tops in these deep flood basalts may offer reservoirs with high mineralization rates, long leakage migration paths, and thick sections of caprock for CO2 storage, a more extensive multi- well characterization would be necessary to assess lateral variations and establish sequestration capacity in this reservoir.
Jung, Hun Bok; Kabilan, Senthil; Carson, James P.; Kuprat, Andrew P.; Um, Wooyong; Martin, Paul F.; Dahl, Michael E.; Kafentzis, Tyler A.; Varga, Tamas; Stephens, Sean A.; Arey, Bruce W.; Carroll, KC; Bonneville, Alain; Fernandez, Carlos A.
2014-08-01T23:59:59.000Z
Composite Portland cement-basalt caprock cores with fractures, as well as neat Portland cement columns, were prepared to understand the geochemical and geomechanical effects on the integrity of wellbores with defects during geologic carbon sequestration. The samples were reacted with CO2-saturated groundwater at 50 ºC and 10 MPa for 3 months under static conditions, while one cement-basalt core was subjected to mechanical stress at 2.7 MPa before the CO2 reaction. Micro-XRD and SEM-EDS data collected along the cement-basalt interface after 3-month reaction with CO2-saturated groundwater indicate that carbonation of cement matrix was extensive with the precipitation of calcite, aragonite, and vaterite, whereas the alteration of basalt caprock was minor. X-ray microtomography (XMT) provided three-dimensional (3-D) visualization of the opening and interconnection of cement fractures due to mechanical stress. Computational fluid dynamics (CFD) modeling further revealed that this stress led to the increase in fluid flow and hence permeability. After the CO2-reaction, XMT images displayed that calcium carbonate precipitation occurred extensively within the fractures in the cement matrix, but only partially along the fracture located at the cement-basalt interface. The 3-D visualization and CFD modeling also showed that the precipitation of calcium carbonate within the cement fractures after the CO2-reaction resulted in the disconnection of cement fractures and permeability decrease. The permeability calculated based on CFD modeling was in agreement with the experimentally determined permeability. This study demonstrates that XMT imaging coupled with CFD modeling represent a powerful tool to visualize and quantify fracture evolution and permeability change in geologic materials and to predict their behavior during geologic carbon sequestration or hydraulic fracturing for shale gas production and enhanced geothermal systems.
Mineralization of Basalts in the CO2-H2O-SO2-O2 System. | EMSL
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
SO2-O2 System. Mineralization of Basalts in the CO2-H2O-SO2-O2 System. Abstract: Sequestering carbon dioxide (CO2) containing minor amounts of co-contaminants in geologic...
Barr, G.E.; Dunn, E.; Dockery, H.; Barnard, R. [Sandia National Labs., Albuquerque, NM (United States)] [Sandia National Labs., Albuquerque, NM (United States); Valentine, G.; Crowe, B. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States)
1993-08-01T23:59:59.000Z
Basaltic volcanism has been identified as a possible future event initiating a release of radionuclides from a potential repository at the proposed Yucca Mountain high-level waste repository site. The performance assessment method set forth in the Site Characterization Plan (DOE, 1988) requires that a set of scenarios encompassing all significant radionuclide release paths to the accessible environment be described. This report attempts to catalogue the details of the interactions between the features and processes produced by basaltic volcanism in the presence of the presumed groundwater flow system and a repository structure, the engineered barrier system (EBS), and waste. This catalogue is developed in the form of scenarios. We define a scenario as a well-posed problem, starting from an initiating event or process and proceeding through a logically connected and physically possible combination or sequence of features, events, and processes (FEPs) to the release of contaminants.
Tian, Liyan
2011-01-01T23:59:59.000Z
and D. R. Hilton (2011), Petrology and Sr-Nd-Pb-He isotopeinvestigation of the petrology and geochemistry of basaltsF. Lonsdale (2008), Petrology and geochemistry of abandoned
Uranium-lead isotope systematics of Mars inferred from the basaltic shergottite QUE 94201
Gaffney, A M; Borg, L E; Connelly, J N
2006-12-22T23:59:59.000Z
Uranium-lead ratios (commonly represented as {sup 238}U/{sup 204}Pb = {mu}) calculated for the sources of martian basalts preserve a record of petrogenetic processes that operated during early planetary differentiation and formation of martian geochemical reservoirs. To better define the range of {mu} values represented by the source regions of martian basalts, we completed U-Pb elemental and isotopic analyses on whole rock, mineral and leachate fractions from the martian meteorite Queen Alexandra Range 94201 (QUE 94201). The whole rock and silicate mineral fractions have unradiogenic Pb isotopic compositions that define a narrow range ({sup 206}Pb/{sup 204}Pb = 11.16-11.61). In contrast, the Pb isotopic compositions of weak HCl leachates are more variable and radiogenic. The intersection of the QUE 94201 data array with terrestrial Pb in {sup 206}Pb/{sup 204}Pb-{sup 207}Pb/{sup 204}Pb-{sup 208}Pb/{sup 204}Pb compositional space is consistent with varying amounts of terrestrial contamination in these fractions. We calculate that only 1-7% contamination is present in the purified silicate mineral and whole rock fractions, whereas the HCl leachates contain up to 86% terrestrial contamination. Despite the contamination, we are able to use the U-Pb data to determine the initial {sup 206}Pb/{sup 204}Pb of QUE 94201 (11.086 {+-} 0.008) and calculate the {mu} value of the QUE 94201 mantle source to be 1.823 {+-} 0.008. This is the lowest {mu} value calculated for any martian basalt source, and, when compared to the highest values determined for martian basalt sources, indicates that {mu} values in martian source reservoirs vary by at least 100%. The range of source {mu} values further indicates that the {mu} value of bulk silicate Mars is approximately three. The amount of variation in the {mu} values of the mantle sources ({mu} {approx} 2-4) is greater than can be explained by igneous processes involving silicate phases alone. We suggest the possibility that a small amount of sulfide crystallization may generate large extents of U-Pb fractionation during formation of the mantle sources of martian basalts.
Kelley, Jill Lynn
2002-01-01T23:59:59.000Z
reported values 44 5 Sample runs and duplicate runs 45 6 Major element analyses of glass, Leg 187 46 7 Major element and LOI analyses for fresh basalt samples, Leg 187 47 8 Major element analyses of altered basalts from Leg 187 49 9 Major oxides... and LOI analyses of altered dredge basalts 51 10 Computed mass change terms after Gresens and Grant 55 11 Correlation coefficients for Leg 187 altered basalts 59 ix LIST OF FIGURES FIGURE Page I Southeast Indian Ocean regional map showing...
Spane, Frank A.
2013-04-29T23:59:59.000Z
Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects
Edmonds, Marie
2014-12-18T23:59:59.000Z
/La and pressure derived from H2O-CO2 saturation (not shown); this is due to both melt 315 heterogeneity inducing variable relationships between degassing and crystallization; and to 316 the effects of post-entrapment crystallization on CO2 sequestration into a... result in a much higher Dv m than 367 observed for terrestrial basalts. The anomalies are unlikely to be due to CO2 fluxing, as 368 observed in carbon-rich systems on Earth (Métrich and Wallace, 2008), as unreasonable 369 fluxes of CO2 would...
Dunbar, Nelia W.
309 NEW MEXICO BUREAU OF GEOLOGY & MINERAL RESOURCES, BULLETIN 160, 2004 Cosmogenic 36Cl ages of lava flows in the ZuniÂBandera volcanic field, northcentral New Mexico, U.S.A. Nelia W. Dunbar1 and Fred M. Phillips2 1New Mexico Bureau of Geology and Mineral Resources, New Mexico Institute of Mining
Geometric Numerical Methods for Numerical Weather Prediction
Langdon, Stephen
-Mesh (HPM) Method · Label space is discretised into N particles with coordinates on the momentum phase space and Sij = (1 - ^2xx)-1. Geometric Numerical Methods for Numerical Weather Prediction p. 8/28 #12;HPM Equations of shallow water motions · The canonical HPM equations of 1D shallow water motion on TS1 are P
Archer, Paul Lawrence
1978-01-01T23:59:59.000Z
1978) Paul Lawrence Archer, B. S. , The Pennsylvania State University Chairman of Advisory Committee: Andrew Hajash Natural seawater and mid-ocean ridge tholeiitic basalt were allowed to react at 100-500'C, and 1000 bars at water/rock mass ratios... temperature experiments at 500'C and temperature- gradient experiments reacted from 200'C to 500 C 53 57 LIST OF FIGURES Figure Page Graphs of Na, Ca, K, and Mg concentrations in 5/1 and 50/1 seawater/basalt experiments as a function of temperature 17...
Lovley, Derek
Hydrogen Chemistry of Basalt Aquifers -- Treiman et al. 282 (5397): 21... http. 2194 DOI: 10.1126/science.282.5397.2194e LETTERS Hydrogen Chemistry of Basalt Aquifers In their report "Evidence against hydrogen-based microbial ecosystems in basalt aquifers" (14 Aug., p. 976), Robert T
Simulating Geologic Co-sequestration of Carbon Dioxide and Hydrogen Sulfide in a Basalt Formation
Bacon, Diana H.; Ramanathan, Ramya; Schaef, Herbert T.; McGrail, B. Peter
2014-01-15T23:59:59.000Z
Co-sequestered CO2 with H2S impurities could affect geologic storage, causing changes in pH and oxidation state that affect mineral dissolution and precipitation reactions and the mobility of metals present in the reservoir rocks. We have developed a variable component, non-isothermal simulator, STOMP-COMP (Water, Multiple Components, Salt and Energy), which simulates multiphase flow gas mixtures in deep saline reservoirs, and the resulting reactions with reservoir minerals. We use this simulator to model the co-injection of CO2 and H2S into brecciated basalt flow top. A 1000 metric ton injection of these supercritical fluids, with 99% CO2 and 1% H2S, is sequestered rapidly by solubility and mineral trapping. CO2 is trapped mainly as calcite within a few decades and H2S is trapped as pyrite within several years.
Nicholson, S.W.; Cannon, W.F. (Geological Survey, Reston, VA (United States)); Woodruff, L.G. (Geological Survey, St. Paul, MN (United States))
1992-01-01T23:59:59.000Z
Whole-rock oxygen (n = 32) and strontium (n = 12) isotopic compositions of basalts erupted during the 1.1 Ga Midcontinent rift event provide evidence for both regional hydrothermal alteration during subsidence and more local alteration related to native Cu mineralization. In the Porcupine Mountains area of northern Michigan, the fissure-fed rift basalts of the Portage Lake volcanics show delta O-18 ca 8--9[per thousand] and Sr-87/Sr-86 = 0.7029--0.7042. Overlying the Portage Lake volcanics are the remnants of a stratavolcano, the Porcupine volcanics. Basalts near the base of the Porcupine Volcanics have delta O-18 ca 8--9[per thousand] and Sr-87/Sr-86 = 0.7027-0.7049, similar to those of the Portage Lake Volcanics. In contrast, basalts near the top of the Porcupine volcanics show higher delta O-18. These values are similar to values for thin basalt flows (Lake Shore Traps) intercalated with conglomerates and sandstones overlying the stratavolcano. The Sr isotopic analyses for basalts from the Porcupine Volcanics, Portage Lake Volcanics and Lake Shore Traps yield an age of 1,060.8 [+-] 66.2 Ma, most probably reflecting the age of the regional hydrothermal alteration. Elevated delta O-18 values of basalts from the lower part of the section can be attributed to pervasive regional prehnite-pumpellyite alteration during burial shortly after eruption. Native Cu mineralization is minor or absent in these rocks. Heavier O-isotopic compositions of the Lake Shore Traps and of the basalts at the top of the Porcupine volcanics reflect localized alteration near deposits of native copper; thus, these upper basalts may have reacted with hydrothermal fluids channeled through adjacent thick conglomerates.
Oxygen buffering of Kilauea volcanic gases and the oxygen fugacity of Kilauea basalt
Gerlach, T.M. (Geological Survey, Vancouver, WA (United States))
1993-02-01T23:59:59.000Z
Volcanic gases collected during episode 1 of the Puu Oo eruption along the east rift zone of Kilauea Volcano, Hawaii, have uniform C-O-H-S-Cl-F compositions that are sharply depleted in CO[sub 2]. The CO[sub 2]-poor gases are typical of Type II volcanic gases (GERLACH and GRAEBER, 1985) and were emitted from evolved magma stored for a prolonged period of time in the east rift zone after releasing CO[sub 2]-rich gases during an earlier period of temporary residence in the summit magma chamber. The samples are remarkably free of contamination by atmospheric gases and meteoric water. Thermodynamic evaluation of the analytical data shows that the episode 1 gases have equilibrium compositions appropriate for temperatures between 935 and 1032[degrees]C. Open- and closed-system equilibrium models of species distributions for the episode 1 gases show unequivocally that coexisting lavas buffered the gas oxygen fugacities during cooling. These models indicate that the F[sub o[sub 2
Teague, L.S.
2010-01-01T23:59:59.000Z
of secondary and primary mineral phases in basalts of theB. , 1975. Perched silia minerals on mordenite fibers. Jour.lt;. UC—70 I SECONDARY MINERALS FOUND IN CORES DC2 AI AND
Santelli, Cara M
2007-01-01T23:59:59.000Z
Basaltic ocean crust has the potential to host one of the largest endolithic communities on Earth. This portion of the biosphere, however, remains largely unexplored. In this study, we utilize molecular biological, ...
2005-10-20T23:59:59.000Z
Page 1. LAB #8. Numerical Methods. Goal: The purpose of this lab is to explain how computers numerically ... Also you will examine what .... (7) Now consider the differential equation ... 3-exp(2*y)+sqrt(t)/y; (Don't forget the “;” at the end.).
M. N. Pace; R. C. Bartholomay (USGS); J. J. Rosentreter (ISU)
1999-07-01T23:59:59.000Z
The U.S. Geological Survey and Idaho State University, in cooperation with the U.S. Department of Energy, are conducting a study to determine and evaluate strontium distribution coefficients (Kds) of subsurface materials at the Idaho National Engineering and Environmental Laboratory (INEEL). The purpose of this study is to aid in assessing the variability of strontium Kds at the INEEL as part of an ongoing investigation of chemical transport of strontium-90 in the Snake River Plain aquifer. Batch experimental techniques were used to determine Kds of six basalt core samples, five samples of sediment infill of vesicles and fractures, and six standard material samples. Analyses of data from these experiments indicate that the Kds of the sediment infill samples are significantly larger than those of the basalt samples. Quantification of such information is essential of furthering the understanding of transport processes of strontium-90 in the Snake River Plain aquifer and in similar environments.
Dove, F.H.; Cole, C.R.; Foley, M.G.
1982-09-01T23:59:59.000Z
A technology demonstration of current performance assessment techniques as applied to a nuclear waste repository in the Columbia Plateau Basalts was conducted. Hypothetical repository coordinates were selected for an actual geographical setting on the Hanford Reservation in the state of Washington. Published hydrologic and geologic data used in the analyses were gathered in 1979 or earlier. The following report documents the technology demonstration in basalt. Available information has been used to establish the data base and initial hydrologic and geologic interpretations for this site-specific application. A simplified diagram of the AEGIS analyses is shown. Because an understanding of the dynamics of ground-water flow is essential to the development of release scenarios and consequence analyses, a key step in the demonstration is the systems characterization contained in the conceptual model. Regional and local ground-water movement patterns have been defined with the aid of hydrologic computer models. Hypothetical release scenarios have been developed and evaluated by a process involving expert opinion and a Geologic Simulation Model for basalt. (The Geologic Simulation Model can also be used to forecast future boundary conditions for the hydrologic simulation.) Chemical reactivity of the basalt with ground water will influence the leaching and transport of radionuclides; solubility equilibria based on available data are estimated with geochemical models. After the radionuclide concentrations are mathematically introduced into the ground-water movement patterns, waste movement patterns are outlined over elapsed time. Contaminant transport results are summarized for significant radionuclides that are hypothetically released to the accessible environment and to the biosphere.
Paces, J.B.; Neal, C.R.; Taylor, L.A. (Univ. of Tennessee, Knoxville (United States)); Nakai, Shun'ichi; Halliday, A.N.; Lee, D.C. (Univ. of Michigan, Ann Arbor (United States))
1991-07-01T23:59:59.000Z
A combined Sr and Nd isotopic study of 15 Apollo 17 high-Ti mare basalts was undertaken to investigate geochronological and compositional differences between previously identified magma types (A, B1, B2, and C). Whole-rock and mineral separates for one of the least-evolved Type B1 basalts, 70139, yield Sm-Nd and Rb-Sr isochron ages of 3.71 {plus minus} 0.12 Ga and 3.65 {plus minus} 0.07 Ga and a Rb-Sr isochron age of 3.67 {plus minus} 0.10 Ga. Although these two ages are non-resolvable by themselves, compilation of all available geochronological data allows resolution of Type A and B1/B2 ages at high levels of confidence (> 99%). The most reliably dated samples, classified according to their geochemical type, yield weighted average ages of 3.75 {plus minus} 0.02 Ga for Type A (N = 4) and 3.69 {plus minus} 0.02 Ga for Type B1/B2 (N = 3) basalts. Insufficient geochronological data are available to place the rare, Type C basalts within this stratigraphy. The authors propose that age differences correlate with geochemical magma type, and that early magmatism was dominated by eruption of Type A basalts while later activity was dominated by effusion of Type B1 and B2 basalts.
Site characterization report for the basalt waste isolation project. Volume II
None
1982-11-01T23:59:59.000Z
The reference location for a repository in basalt for the terminal storage of nuclear wastes on the Hanford Site and the candidate horizons within this reference repository location have been identified and the preliminary characterization work in support of the site screening process has been completed. Fifteen technical questions regarding the qualification of the site were identified to be addressed during the detailed site characterization phase of the US Department of Energy-National Waste Terminal Storage Program site selection process. Resolution of these questions will be provided in the final site characterization progress report, currently planned to be issued in 1987, and in the safety analysis report to be submitted with the License Application. The additional information needed to resolve these questions and the plans for obtaining the information have been identified. This Site Characterization Report documents the results of the site screening process, the preliminary site characterization data, the technical issues that need to be addressed, and the plans for resolving these issues. Volume 2 contains chapters 6 through 12: geochemistry; surface hydrology; climatology, meteorology, and air quality; environmental, land-use, and socioeconomic characteristics; repository design; waste package; and performance assessment.
Numerical Analysis Gordon K. Smyth
Smyth, Gordon K.
Numerical Analysis Gordon K. Smyth May 1997 Numerical analysis is concerned with the accurate discipline of numerÂ ical analysis is almost entirely a product of the period since 1950 during which biostatisticians can benefit from familiarity with numerical analysis. An understanding of the numerical methods
Summary of INEL research on the iron-enriched basalt waste form
Reimann, G.A.; Grandy, J.D.; Eddy, T.L.; Anderson, G.L.
1992-01-01T23:59:59.000Z
This report summarizes the knowledge base on the iron-enriched basalt (IEB) waste form developed at the Idaho National Engineering Laboratory (INEL) during 1979--1982. The results presented discuss the applicability of IEB in converting retrieved transuranic (TRU) waste from INEL`s Radioactive Waste Management Complex (RWMC) into a vitreous/ceramic (glassy/rock) stable waste form suitable for permanent disposal in an appropriate repository, such as the Waste Isolation Pilot Plant (WIPP) in New Mexico. Borosilicate glass (BSG), the approved high-level waste form, appears unsuited for this application. Melting the average waste-soil mix from the RWMC produces the IEB composition and attempting to convert IEB to the BSG composition would require additions of substantial B{sub 2}0{sub 3}, Na, and SiO{sub 2} (glass frit). IEB requires processing temperatures of 1400 to 1600{degrees}C, depending upon the waste composition. Production of the IEB waste form, using Joule heated melters, has proved difficult in the past because of electrode and refractory corrosion problems associated with the high temperature melts. Higher temperature electric melters (arc and plasma) are available to produce this final waste form. Past research focused on extensive slag property measurements, waste form leachability tests, mechanical, composition, and microstructure evaluations, as well as a host of experiments to improve production of the waste form. Past INEL studies indicated that the IEB glass-ceramic is a material that will accommodate and stabilize a wide range of heterogeneous waste materials, including long lived radionuclides and scrap metals, while maintaining a superior level of chemical and physical performance characteristics. Controlled cooling of the molten IEB and subsequent heat treatment will produce a glass-ceramic waste form with superior leach resistance.
Summary of INEL research on the iron-enriched basalt waste form
Reimann, G.A.; Grandy, J.D.; Eddy, T.L.; Anderson, G.L.
1992-01-01T23:59:59.000Z
This report summarizes the knowledge base on the iron-enriched basalt (IEB) waste form developed at the Idaho National Engineering Laboratory (INEL) during 1979--1982. The results presented discuss the applicability of IEB in converting retrieved transuranic (TRU) waste from INEL's Radioactive Waste Management Complex (RWMC) into a vitreous/ceramic (glassy/rock) stable waste form suitable for permanent disposal in an appropriate repository, such as the Waste Isolation Pilot Plant (WIPP) in New Mexico. Borosilicate glass (BSG), the approved high-level waste form, appears unsuited for this application. Melting the average waste-soil mix from the RWMC produces the IEB composition and attempting to convert IEB to the BSG composition would require additions of substantial B{sub 2}0{sub 3}, Na, and SiO{sub 2} (glass frit). IEB requires processing temperatures of 1400 to 1600{degrees}C, depending upon the waste composition. Production of the IEB waste form, using Joule heated melters, has proved difficult in the past because of electrode and refractory corrosion problems associated with the high temperature melts. Higher temperature electric melters (arc and plasma) are available to produce this final waste form. Past research focused on extensive slag property measurements, waste form leachability tests, mechanical, composition, and microstructure evaluations, as well as a host of experiments to improve production of the waste form. Past INEL studies indicated that the IEB glass-ceramic is a material that will accommodate and stabilize a wide range of heterogeneous waste materials, including long lived radionuclides and scrap metals, while maintaining a superior level of chemical and physical performance characteristics. Controlled cooling of the molten IEB and subsequent heat treatment will produce a glass-ceramic waste form with superior leach resistance.
Till, Christy B.
Plagioclase and spinel lherzolite thermometry and barometry are applied to an extensive geochemical dataset of young (<10.5?Ma) primitive basaltic lavas from across Oregon's High Lava Plains, California's Modoc Plateau, ...
Numerical Integration Gordon K. Smyth
Smyth, Gordon K.
Numerical Integration Gordon K. Smyth in Encyclopedia of Biostatistics (ISBN 0471 975761) Edited by Peter Armitage and Theodore Colton John Wiley & Sons, Ltd, Chichester, 1998 #12;Numerical Integration Numerical integration is the study of how the numerical value of an integral can be found. Also called
11. NUMERICAL TECHNIQUES 1 Numerical identification of effective multipole
Boyer, Edmond
11. NUMERICAL TECHNIQUES 1 Numerical identification of effective multipole moments of polarizable of the induced multipole moments. A general multipole theory is available in the literature, however, only linear multipole model is usually exploited when determining numerically these effective moments. Since this axial
Cohen, Barbara Anne
processing. Rapid extraction of partial melts from a range of depths could leave intact the range of characterized 171 feldspathic clasts in these meteorites in terms of texture, mineralogy, and mineral compo to represent a common igneous (generally basaltic) lithology and whose mafic minerals show a normal igneous
Perfect, Ed
differences in the mantle source to explain the $25% difference in whole-rock TiO2, and corresponding-normative basalt types, based on their different SiO2, FeO, and TiO2 whole-rock compositions. Previous studies have as originating from different lunar mantle source regions. To provide new information on the compositions
Numerical Integration Gordon K. Smyth
Smyth, Gordon K.
Numerical Integration Gordon K. Smyth May 1997 Numerical integration is the study of how the numerical value of an integral can be found. Also called quadrature, which refers to finding a square whose \\Lambda . Of central interest is the process of approximating a definite integral from values of the in
Numerical Analysis Gordon K. Smyth
Smyth, Gordon K.
Numerical Analysis Gordon K. Smyth in Encyclopedia of Biostatistics (ISBN 0471 975761) Edited by Peter Armitage and Theodore Colton John Wiley & Sons, Ltd, Chichester, 1998 #12;Numerical Analysis Numerical analysis is concerned with the accurate and efficient evalua- tion of mathematical expressions
Dynamical Spacetimes from Numerical Hydrodynamics
Allan Adams; Nathan Benjamin; Arvin Moghaddam; Wojciech Musial
2014-11-07T23:59:59.000Z
We numerically construct dynamical asymptotically-AdS$_4$ metrics by evaluating the fluid/gravity metric on numerical solutions of dissipative hydrodynamics in (2+1) dimensions. The resulting numerical metrics satisfy Einstein's equations in (3+1) dimensions to high accuracy.
Reidel, Steve P.; Spane, Frank A.; Johnson, Vernon G.
2005-09-24T23:59:59.000Z
Between 1999 and 2002, Pacific Gas Transmission Company (PGT) (now TransCanada Pipeline Company) and AVISTA Corporation, together with technical support provided by the Pacific Northwest National Laboratory and the U.S. Department of Energy (DOE) examined the feasibility of developing a subsurface, natural gas-storage facility in deep, underlying Columbia River basalt in south-central Washington state. As part of this project, the 100 Circles #1 well was drilled and characterized in addition to surface studies. This report provides data and interpretations of the geology and hydrology collected specific to the Canoe Ridge site as part of the U.S. DOE funding to the Pacific Northwest National Laboratory in support of this project.
Palmour, H. III; Dosch, R.G.; Macedo, P.B.; Machiels, A.J.; Owen, D.E.
1981-09-01T23:59:59.000Z
The purpose of the Peer Review Panel was to provide an independent review by experts in nuclear waste processing and materials on the adequacy of the existing data base for the iron-enriched basalt waste form developed by EG and G Idaho, and to evaluate the broad range of proposed applications for this waste form. It was not the purpose of this review to specifically rank iron-enriched basalt against other nuclear waste forms. It was the concensus of the Peer Review Panel that the concept, experimental research, and identification of potential applications of the iron-enriched basalt waste form were of high quality. Iron-enriched basalt is a primarily ceramic waste form with a residual glass phase. It has a broad range of composition, permitting the incorporation of a wide variety of nuclear wastes. The product has good mechanical strength and produces very low quantities of respirable particles under impact conditions. Matrix dissolution rates under neutral pH conditions are comparable to or lower than those of borosilicate glass. In the area of waste form characterization, the Panel recommended additional static and dynamic leaching tests as a function of pH and CO/sub 2/ in solution, and in brine solutions of varying composition. The panel also recommended that unprocessed transuranic (TRU) wastes be subjected to leach tests. Large-scale iron-enriched basalt castings in which the grain growth was uncontrolled have been observed to be less durable than controlled-grain-growth laboratory-scale castings. Therefore, the Panel also recommended leaching tests as a function of microstructure to determine ranges of acceptable microstructure. In the area of the IEB production process, the Panel recommended a variety of laboratory-scale and pilot plant-scale research.
Numerical Modeling of HCCI Combustion
Broader source: Energy.gov (indexed) [DOE]
Numerical Modeling of HCCI Combustion Salvador M. Aceves, Daniel L. Flowers, J. Ray Smith, Joel Martinez-Frias, Francisco Espinosa-Loza, Tim Ross, Bruce Buchholz, Nick...
NumericalS imulation of Cooling Gas Injection Using
NumericalS imulation of Cooling Gas Injection Using Adaptive Multiscale Techniques Wolfgang Dahmen words:fi nite volume method,fi lm cooling, cooling gas injection, multiscale techniques, grid adaptation#ciency is investigated. Keywords: Finite Volum Method,Film cooling, Cooling gas injection, Multiscale techniques, Grid
The Numerical Simulation of Turbulence
W. Schmidt
2007-12-06T23:59:59.000Z
In this contribution, I give an overview of the various approaches toward the numerical modelling of turbulence, particularly, in the interstellar medium. The discussion is placed in a physical context, i. e. computational problems are motivated from basic physical considerations. Presenting selected examples for solutions to these problems, I introduce the basic ideas of the most commonly used numerical methods.
NUMERICAL ANALYSIS KENDALL E. ATKINSON
Atkinson, Kendall
of mathematics and computer science that creates, analyzes, and implements algorithms for solving nu- merically mathematical models in science and engineering, and numerical analysis of increasing sophistication has been of numerical analysis varies from quite theoretical mathematical studies (e.g. see [5]) to computer science
Johnson, Phillip R
2013-06-05T23:59:59.000Z
ELEMENTAL AND TECHNOLOGICAL ANALYSES OF BASALT ADZE MANUFACTURE ON TUTUILA, AMERIKA SAMOA: ECONOMIC INTENSIFICATION AND SPECIALIZATION DURING THE MONUMENT BUILDING PERIOD A Dissertation by PHILLIP RAY JOHNSON II Submitted... to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Chair of Committee, Suzanne Eckert Committee Members, William D. James Michael R. Waters Ted...
C. Doc Richardson; Nancy W. Hinman; Jill R. Scott
2013-10-01T23:59:59.000Z
Evidence of microbial activity associated with mineralization of secondary Na-sulphate minerals (thenardite, mirabilite) in the basaltic subsurface of Craters of the Moon National Monument (COM), Idaho were examined by scanning electron microscopy, X-ray diffraction, laser desorption Fourier transform ion cyclotron resonance mass spectrometry (LD-FTICR-MS), Fourier transform infrared spectroscopy (FTIR) and isotope ratio mass spectrometry. Peaks suggestive of bio/organic compounds were observed in the secondary Na-sulphate deposits by LD-FTICR-MS. FTIR provided additional evidence for the presence of bio/organic compounds. Sulphur fractionation was explored to assist in determining if microbes may play a role in oxidizing sulphur. The presence of bio/organic compounds associated with Na-sulphate deposits, along with the necessity of oxidizing reduced sulphur to sulphate, suggests that biological activity may be involved in the formation of these secondary minerals. The secondary Na-sulphate minerals probably form from the overlying basalt through leached sodium ions and sulphate ions produced by bio-oxidation of Fe-sulphide minerals. Since the COM basalts are one of the most comparable terrestrial analogues for their Martian counterparts, the occurrence of biological activity in the formation of sulphate minerals at COM has direct implications for the search for life on Mars. In addition, the presence of caves on Mars suggests the importance of these environments as possible locations for growth and preservation of microbial activity. Therefore, understanding the physiochemical pathways of abiotic and biotic mineralization in the COM subsurface and similar basaltic settings has direct implications for the search for extinct or extant life on Mars.
Crisman, D.P.; Jacobs, G.K.
1982-01-01T23:59:59.000Z
Copper deposits in the Portage Lake Volcanics of northern Michigan have been evaluated as a natural analogue for canister material to be emplaced in a nuclear waste repository located in the basalts beneath the Hanford Site near Richland, Washington. Te native copper, which precipitated from high temperature (200/sup 0/C to 300/sup 0/C) hydrothermal solutions between 500 and 800 million yr ago, has remained relatively unaltered in the Portage lake basalt-groundwater system. The results of this study illustrate the stability of copper in solutions of moderate pH, low to moderate Eh, and low total dissolved solids. Chemical trends and geochemical modeling of te near-surface waters suggestthat similarities (moderate pH, low E, low total dissolved solids) exist between the groundwater-basalt system of the Keweenaw Peninsula and the groundwater-basalt system at the Hanford Site. These similarities and the stability of copper in the Keweenswan basalts imply that copper alloys are adequate materials for nuclear waste canisters emplaced in a repository located in basalt.
Jeff Sondrup; Gail Heath; Trent Armstrong; Annette Shafer; Jesse Bennett; Clark Scott
2011-04-01T23:59:59.000Z
This report presents the seismic refraction results from the depth to bed rock surveys for two areas being considered for the Remote-Handled Low-Level Waste (RH-LLW) disposal facility at the Idaho National Laboratory. The first area (Site 5) surveyed is located southwest of the Advanced Test Reactor Complex and the second (Site 34) is located west of Lincoln Boulevard near the southwest corner of the Idaho Nuclear Technology and Engineering Center (INTEC). At Site 5, large area and smaller-scale detailed surveys were performed. At Site 34, a large area survey was performed. The purpose of the surveys was to define the topography of the interface between the surficial alluvium and underlying basalt. Seismic data were first collected and processed using seismic refraction tomographic inversion. Three-dimensional images for both sites were rendered from the data to image the depth and velocities of the subsurface layers. Based on the interpreted top of basalt data at Site 5, a more detailed survey was conducted to refine depth to basalt. This report briefly covers relevant issues in the collection, processing and inversion of the seismic refraction data and in the imaging process. Included are the parameters for inversion and result rendering and visualization such as the inclusion of physical features. Results from the processing effort presented in this report include fence diagrams of the earth model, for the large area surveys and iso-velocity surfaces and cross sections from the detailed survey.
Walton, A.W.; Salter, T.L.; Zetterlund, D.
1980-08-01T23:59:59.000Z
Geological environments present in southwestern New Mexico include thick sequences of sedimentary rock including limestone, conglomerates, sandstone, and shale: igneous intrusions with associated metal deposits; caldera centers, margins, and outflow facies; and basins with marginal faults and thick late Cenozoic sedimentary fillings. Predominant rock types are Paleozoic carbonates, Mesozoic terrigeneous rocks and carbonates, and Cenozoic volcanic rocks and basin-filling terrigeneous rocks. Consideration of information available in Preliminary Reconnaissance Reports and in Hydrogeochemical and Stream Reconnaissance Reports together with 347 new whole rock chemical analyses points to three areas of anomalous uranium abundance in Hidalgo County, New Mexico. The area has experienced three major periods of igneous activity in Phanerozoic time: one associated with the Laramide cycle of the Late Cretaceous and early Tertiary, mid-Tertiary cycle of silicic volcanism with abundant calderas, and a late Tertiary cycle of mafic volcanism. Silicic volcanic rocks are the most common exposed rock type in the area, and the most enriched in uranium (range, 0.4 to 19 ppM). The most likely source for any uranium ore-forming solutions lies with this cycle of volcanism. Solutions might have been introduced during volcanism or formed later by groundwater leaching of cooled volcanic rocks. Results indicate that groundwater leaching of cooled volcanic rocks was not an effective means of mobilizing uranium in the area. Study of several rhyolite lava flows indicates that they were emplaced in supercooled condition and may have crystallized completely at temperatures well below their liquids, or they may have warmed as crystallization released latent heat. Statistical comparison of the uranium concentration revealed no differences between vitrophyres and associated felsites.
Physical and Numerical Space Running Head: Biases in Physical and Numerical Space
Chatterjee, Anjan
Physical and Numerical Space 1 Running Head: Biases in Physical and Numerical Space Elementary school children's attentional biases in physical and numerical space Tilbe GÃ¶ksun: April 30, 2012 #12; Physical and Numerical Space 2 Abstract Numbers
Numerical methods in heat transfer
Emery, A.F.; Douglass, R.W.
1988-01-01T23:59:59.000Z
This book contains nine papers. Some of the titles are: Numerical calculation of bubble growth in nucleate boiling from inception through departure; An evaluation of a translator for finite element data to resistor/capacitor data for the heat diffusion; Thermophoretic deposition due to jet impingement on an inclined plane; and A three-dimensional boundary-fitted coordinate system.
Numerical bifurcation analysis of piecewise smooth systems
( ) ( ) ( ) ( ), , outoutinin inin xffxff xhhxgg xxxx == == #12;Numerical bifurcation analysis of piecewise smooth systems INRIA
Lava Dome | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer Plant Jump to:Landowners and Wind Energy DevelopmentLaurentian Energy Authority Jump to:Dome
Numerical integration of variational equations
Ch. Skokos; E. Gerlach
2010-09-29T23:59:59.000Z
We present and compare different numerical schemes for the integration of the variational equations of autonomous Hamiltonian systems whose kinetic energy is quadratic in the generalized momenta and whose potential is a function of the generalized positions. We apply these techniques to Hamiltonian systems of various degrees of freedom, and investigate their efficiency in accurately reproducing well-known properties of chaos indicators like the Lyapunov Characteristic Exponents (LCEs) and the Generalized Alignment Indices (GALIs). We find that the best numerical performance is exhibited by the \\textit{`tangent map (TM) method'}, a scheme based on symplectic integration techniques which proves to be optimal in speed and accuracy. According to this method, a symplectic integrator is used to approximate the solution of the Hamilton's equations of motion by the repeated action of a symplectic map $S$, while the corresponding tangent map $TS$, is used for the integration of the variational equations. A simple and systematic technique to construct $TS$ is also presented.
Numerical simulation of hydraulic fracturing
Warner, Joseph Barnes
1987-01-01T23:59:59.000Z
~ared that the results of such treatments were not always adequately described by the two-dimensional models. With recent advances in hydraulic fracturing and computing technology, attempts have been made to formulate more realistic fracture models. These three...NUMERICAL SIMULATION OF HYDRAULIC FRACTURING A Thesis by JOSEPH BARNES WARNER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1987 Maj or Subj ect...
Numerical calculation of Green's functions
Urrea-Beltran, Julian
1975-01-01T23:59:59.000Z
, for his assistance in the preparation of this thesis, and Dr. Francis J. Narcowich and Dr. Phillip J. Green for serving as members of my committee. I am also grateful to Dr. Norman W. Naugle for hia guidance in using the Hewlett Packard Computer... concerning the numerical results (V) are given. The computations were done on the IBM 360 of Texas A&M University and the graphs on the Hewlett Packard 9830A digital computer of the Mathematics Department. The citations on the following pages follow...
Disruptive Innovation in Numerical Hydrodynamics
Waltz, Jacob I. [Los Alamos National Laboratory
2012-09-06T23:59:59.000Z
We propose the research and development of a high-fidelity hydrodynamic algorithm for tetrahedral meshes that will lead to a disruptive innovation in the numerical modeling of Laboratory problems. Our proposed innovation has the potential to reduce turnaround time by orders of magnitude relative to Advanced Simulation and Computing (ASC) codes; reduce simulation setup costs by millions of dollars per year; and effectively leverage Graphics Processing Unit (GPU) and future Exascale computing hardware. If successful, this work will lead to a dramatic leap forward in the Laboratory's quest for a predictive simulation capability.
Class Generation for Numerical Wind Atlases
Class Generation for Numerical Wind Atlases RisÃ¸ National Laboratory Wind Energy Department and The Technical University of Denmark Informatics and Mathematical Modelling Department Nicholas J. Cutler s000144 Constructing a Numerical Wind Atlas 5 2.1 Introduction
Simulating Reionization in Numerical Cosmology
Aaron Sokasian; Tom Abel; Lars E. Hernquist
2001-05-10T23:59:59.000Z
The incorporation of radiative transfer effects into cosmological hydrodynamical simulations is essential for understanding how the intergalactic medium (IGM) makes the transition from a neutral medium to one that is almost fully ionized. Here, we present an approximate numerical method designed to study in a statistical sense how a cosmological density field is ionized by a set of discrete point sources. A diffuse background radiation field is also computed self-consistently in our procedure. The method requires relatively few time steps and can be employed with simulations having high resolution. We describe the details of the algorithm and provide a description of how the method can be applied to the output from a pre-existing cosmological simulation to study the systematic reionization of a particular ionic species. As a first application, we compute the reionization of He II by quasars in the redshift range 3 to 6.
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2005; 12:683
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2005; 12:683 Published Numerical Linear Algebra and its Applications The fourth workshop of the ERCIM Working Group on `Matrix Computations and Statistics' and the First International workshop on `Numerical Linear Algebra and its
Numerical Simulations of Thermobaric Explosions
Kuhl, A L; Bell, J B; Beckner, V E; Khasainov, B
2007-05-04T23:59:59.000Z
A Model of the energy evolution in thermobaric explosions is presented. It is based on the two-phase formulation: conservation laws for the gas and particle phases along with inter-phase interaction terms. It incorporates a Combustion Model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gas dynamic fields. The Model takes into account both the afterburning of the detonation products of the booster with air, and the combustion of the fuel (Al or TNT detonation products) with air. Numerical simulations were performed for 1.5-g thermobaric explosions in five different chambers (volumes ranging from 6.6 to 40 liters and length-to-diameter ratios from 1 to 12.5). Computed pressure waveforms were very similar to measured waveforms in all cases - thereby proving that the Model correctly predicts the energy evolution in such explosions. The computed global fuel consumption {mu}(t) behaved as an exponential life function. Its derivative {dot {mu}}(t) represents the global rate of fuel consumption. It depends on the rate of turbulent mixing which controls the rate of energy release in thermobaric explosions.
February 25, 2005 NUMERICAL ENERGY CONSERVATION FOR
TÃ¼bingen, UniversitÃ¤t
February 25, 2005 NUMERICAL ENERGY CONSERVATION FOR MULTIÂFREQUENCY OSCILLATORY DIFFERENTIAL systems, modulated Fourier expansion, energy conservation, oscillatory solutions. 1 Introduction
February 6, 2004 NUMERICAL ENERGY CONSERVATION FOR
Hairer, Ernst
February 6, 2004 NUMERICAL ENERGY CONSERVATION FOR MULTIÂFREQUENCY OSCILLATORY DIFFERENTIAL, Hamiltonian systems, modulated Fourier expansion, energy conservation, oscillatory solutions. 1 Introduction
Adjoint Sensitivity Analysis for Numerical Weather Prediction
Alexandru Cioaca
2011-09-02T23:59:59.000Z
Sep 2, 2011 ... Adjoint Sensitivity Analysis for Numerical Weather Prediction: Applications to Power Grid Optimization. Alexandru Cioaca(alexgc ***at*** vt.edu)
The Joint Essential Numerical Range of operators
Li, Chi-Kwong
The Joint Essential Numerical Range of operators: Convexity and Related Results Chi-Kwong Li Classification 47A12, 47A13, 47A55. Keywords Joint essential numerical range, self-adjoint operator, Hilbert the joint behavior of several operators A1, . . . , Am. One may see [1, 5, 12, 14, 15, 16, 19, 23, 28, 31
Numerical Simulation of Cooling Gas Injection Using
Numerical Simulation of Cooling Gas Injection Using Adaptive Multiscale Techniques Wolfgang Dahmen: finite volume method, film cooling, cooling gas injection, multiscale techniques, grid adaptation AMS@igpm.rwth-aachen.de (Thomas Gotzen) #12;Numerical simulation of cooling gas injection using adaptive multiscale techniques
Numerical Study of a Turbulent Hydraulic Jump
Zhao, Qun
Numerical Study of a Turbulent Hydraulic Jump Qun Zhao, Shubhra Misra, Ib. A. Svendsen and James T of a Turbulent Hydraulic Jump p.1/14 #12;Objective Our ultimate goal is to study the breaking waves. Numerical Study of a Turbulent Hydraulic Jump p.2/14 #12;A moving bore Qiantang Bore China (Courtesy of Dr J
Nonclassicality thresholds for multiqubit states: Numerical analysis
Gruca, Jacek; Zukowski, Marek [Institute of Theoretical Physics and Astrophysics, University of Gdansk, PL-80-952 Gdansk (Poland); Laskowski, Wieslaw [Institute of Theoretical Physics and Astrophysics, University of Gdansk, PL-80-952 Gdansk (Poland); Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, D-80799 Muenchen (Germany); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Kiesel, Nikolai [Faculty of Physics, University of Vienna, A-1090 Vienna (Austria); Wieczorek, Witlef; Weinfurter, Harald [Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, D-80799 Muenchen (Germany); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Schmid, Christian [Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, D-80799 Muenchen (Germany); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); European Organisation for Astronomical Research in the Southern Hemisphere, D-85748 Garching (Germany)
2010-07-15T23:59:59.000Z
States that strongly violate Bell's inequalities are required in many quantum-informational protocols as, for example, in cryptography, secret sharing, and the reduction of communication complexity. We investigate families of such states with a numerical method which allows us to reveal nonclassicality even without direct knowledge of Bell's inequalities for the given problem. An extensive set of numerical results is presented and discussed.
Buscaglia, Gustavo C.
2012-01-01T23:59:59.000Z
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING Int. J. Numer. Meth. Biomed iterative coupling of dimen- sionally heterogeneous flow models in computational hemodynamics. INTRODUCTION In recent years, several efforts have been directed at integrating different mathematical models
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2011; 18:961980
De Sterck, Hans
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2011; 18:961980 Published aggregation method of [1], and the Markov chain algebraic multigrid (MCAMG) method of [3] using the OTF
West, Matthew
momentum and energy conservation characteristics, as several numerical examples demonstrate. Copyright 2005INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING Int. J. Numer. Meth. Engng 2005; 64Center for Advanced Computing Research, California Institute of Technology, Mail Code 158-79, Pasadena
Toward standard testbeds for numerical relativity
Miguel Alcubierre; Gabrielle Allen; Carles Bona; David Fiske; Tom Goodale; F. Siddharta Guzman; Ian Hawke; Scott H. Hawley; Sascha Husa; Michael Koppitz; Christiane Lechner; Denis Pollney; David Rideout; Marcelo Salgado; Erik Schnetter; Edward Seidel; Hisa-aki Shinkai; Bela Szilagyi; Deirdre Shoemaker; Ryoji Takahashi; Jeffrey Winicour
2003-05-06T23:59:59.000Z
In recent years, many different numerical evolution schemes for Einstein's equations have been proposed to address stability and accuracy problems that have plagued the numerical relativity community for decades. Some of these approaches have been tested on different spacetimes, and conclusions have been drawn based on these tests. However, differences in results originate from many sources, including not only formulations of the equations, but also gauges, boundary conditions, numerical methods, and so on. We propose to build up a suite of standardized testbeds for comparing approaches to the numerical evolution of Einstein's equations that are designed to both probe their strengths and weaknesses and to separate out different effects, and their causes, seen in the results. We discuss general design principles of suitable testbeds, and we present an initial round of simple tests with periodic boundary conditions. This is a pivotal first step toward building a suite of testbeds to serve the numerical relativists and researchers from related fields who wish to assess the capabilities of numerical relativity codes. We present some examples of how these tests can be quite effective in revealing various limitations of different approaches, and illustrating their differences. The tests are presently limited to vacuum spacetimes, can be run on modest computational resources, and can be used with many different approaches used in the relativity community.
Provably Efficient Algorithms for Numerical Tensor Edgar Solomonik
California at Berkeley, University of
Provably Efficient Algorithms for Numerical Tensor Algebra Edgar Solomonik Electrical Engineering for Numerical Tensor Algebra by Edgar Solomonik A dissertation submitted in partial satisfaction-Gordon Fall 2014 #12;Provably Efficient Algorithms for Numerical Tensor Algebra Copyright 2014 by Edgar
Origin and evolution of magmas on the Ontong Java Plateau J. GODFREY FITTON 1 & MARGUERITE GODARD 2
Demouchy, Sylvie
DrillingProject (DSDP) and Ocean DrillingProgram (ODP) drill sites on the plateau and in the adjacent on the plateau (Deep Sea Drilling Project (DSDP) Site 289 and Ocean Drilling Program (ODP) Sites 803 and 807) had penetrated basaltic basement. Five more basement sites were drilled during ODP Leg 192; basaltic lava flows
KWIC Index for Numerical Linear Algebra
Carpenter, J.A.
1983-07-01T23:59:59.000Z
This report is a sequel to ORNL/CSD-106 in the ongoing supplements to Professor A.S. Householder's KWIC Index for Numerical Algebra. Beginning with the previous supplement, the subject has been restricted to Numerical Linear Algebra, roughly characterized by the American Mathematical Society's classification sections 15 and 65F but with little coverage of infinite matrices, matrices over fields of characteristics other than zero, operator theory, optimization and those parts of matrix theory primarily combinatorial in nature. Some consideration is given to the uses of graph theory in Numerical Linear Algebra, particularly with respect to algorithms for sparse matrix computations. The period covered by this report is roughly the calendar year 1982 as measured by the appearance of the articles in the American Mathematical Society's Contents of Mathematical Publications lagging actual appearance dates by up to nearly half a year. The review citations are limited to the Mathematical Reviews (MR).
High performance computing and numerical modelling
,
2014-01-01T23:59:59.000Z
Numerical methods play an ever more important role in astrophysics. This is especially true in theoretical works, but of course, even in purely observational projects, data analysis without massive use of computational methods has become unthinkable. The key utility of computer simulations comes from their ability to solve complex systems of equations that are either intractable with analytic techniques or only amenable to highly approximative treatments. Simulations are best viewed as a powerful complement to analytic reasoning, and as the method of choice to model systems that feature enormous physical complexity such as star formation in evolving galaxies, the topic of this 43rd Saas Fee Advanced Course. The organizers asked me to lecture about high performance computing and numerical modelling in this winter school, and to specifically cover the basics of numerically treating gravity and hydrodynamics in the context of galaxy evolution. This is still a vast field, and I necessarily had to select a subset ...
Developments in Petroleum Science, 6 FUNDAMENTALS OF NUMERICAL
Santos, Juan
Developments in Petroleum Science, 6 FUNDAMENTALS OF NUMERICAL RESERVOIR SIMULATION DONALD WCongressCatalogingin PublicationData Peaceman, Donald W Fundamentals of numerical reservoir simulation. (develrpents in petroleum
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth. Fluids 2011; 00:123
Buscaglia, Gustavo C.
, magma chambers, fluidfuel interactions, crude oil recovery, spray cans, sediment transport in riversINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth. Fluids 2011; 00 for the treatment of discontinuous pressures in multifluid flows Roberto F. Ausas1 , Gustavo C. Buscaglia1
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2008; 15:115139
De Sterck, Hans
NUMERICAL LINEAR ALGEBRA WITH APPLICATIONS Numer. Linear Algebra Appl. 2008; 15:115139 Published-two interpolation for parallel algebraic multigrid Hans De Sterck1, Robert D. Falgout2, Joshua W. Nolting3, Campus Box 526, Boulder, CO 80302, U.S.A. SUMMARY Algebraic multigrid (AMG) is one of the most efficient
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING Int. J. Numer. Meth. Engng (2014)
Leyendecker, Sigrid
2014-01-01T23:59:59.000Z
to ensure exact energy conservation in conservative systems, and the right rate of energy decayINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING Int. J. Numer. Meth. Engng (2014Computational Mechanics Group, California Institute of Technology, Mail Code 105-50, Pasadena, CA 91125, USA 2
Ortiz, Michael
in order to ensure exact energy conservation in conservative systems, and the right rate of energy decayINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING Int. J. Numer. Meth. Engng 2014; 100,*, and M. Ortiz1 1Computational Mechanics Group, California Institute of Technology, Mail Code 105
Jiao, Xiangmin "Jim"
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING Int. J. Numer. Meth. Engng 2004; 61 Jiao and Michael T. Heath, Computational Science and Engineering, University of Illinois at Urbana, and combustion, in an efficient and accurate manner. The multidisciplinary nature of such systems suggests
ENERGY CONSERVATION BY ORMERTYPE NUMERICAL INTEGRATORS
TÃ¼bingen, UniversitÃ¤t
ENERGY CONSERVATION BY ST Â¨ ORMERÂTYPE NUMERICAL INTEGRATORS ERNST HAIRER \\Lambda AND CHRISTIAN the longÂtime energy conservation by a class of methods which integrate the linear part of oscillatory. HAIRER AND CH. LUBICH 2. Energy conservation by symmetric methods used with small step size
Numerical Linear Algebra and Optimization on Facebook
Sidorov, Nikita
Numerical Linear Algebra and Optimization on Facebook: "In a relationship" or "It's complicated indicate their "relationship status" on Facebook (!!!). (I don't need to define Facebook, right?) #12;Facebook is close to ubiquitous (1.2 billion users in March 2014). 556 million people log on to Facebook
Threedimensional numerical simulation for various geometries
Herbin, Raphaèle
modelling and numerical simulation of natural gasfed solid oxide cells (Solid Oxide Fuel Cell, SOFC) at a stationary regime. The principle of a Solid Oxide Fuel Cell (SOFC) is based on the conversion of the chemical is taken into account in the present model. The SOFC systems seem to be of great interest for use
Numerical Analysis Department Robustness improvement of
Vuik, Kees
Numerical Analysis Department Robustness improvement of polyhedral mesh method for airbag of polyhedral mesh method for airbag deployment simulations MASTER OF SCIENCE THESIS For the degree of Master entitled ROBUSTNESS IMPROVEMENT OF POLYHEDRAL MESH METHOD FOR AIRBAG DEPLOYMENT SIMULATIONS by SANTIAGO
Two physical characteristics of numerical apparent horizons
Ivan Booth
2007-12-20T23:59:59.000Z
This article translates some recent results on quasilocal horizons into the language of $(3+1)$ general relativity so as to make them more useful to numerical relativists. In particular quantities are described which characterize how quickly an apparent horizon is evolving and how close it is to either equilibrium or extremality.
Symplectic numerical integration of Hamiltonian systems
Scovel, C.
1989-09-11T23:59:59.000Z
This paper describes some general techniques available for symplectic or Lie-Poisson integration and illustrate the results with some numerical computations. In this spirit, I also discuss reversible integration, equivariant integration, integration of volume preserving flows, and symplectic cellular automata. My intention is not to be exhaustive but to give a representative review. 76 refs., 5 figs.
Numerical likelihood analysis of cosmic ray anisotropies
Carlos Hojvat et al.
2003-07-02T23:59:59.000Z
A numerical likelihood approach to the determination of cosmic ray anisotropies is presented which offers many advantages over other approaches. It allows a wide range of statistically meaningful hypotheses to be compared even when full sky coverage is unavailable, can be readily extended in order to include measurement errors, and makes maximum unbiased use of all available information.
Numerical Valuation of Discrete Barrier Options with
Chu, Hao-hua
Numerical Valuation of Discrete Barrier Options with the Adaptive Mesh Model and Other Competing for discrete barrier options such that many methods have been suggested and declared to price discrete barrier options fast and accurately but no one can tell exactly that what method is the best. We also make
NUMERICAL APPROACHES TO THERMALLY COUPLED PERFECT PLASTICITY
Bartels, Soeren
NUMERICAL APPROACHES TO THERMALLY COUPLED PERFECT PLASTICITY S¨OREN BARTELS AND TOM´AS ROUB at small strains exhibiting also stress-driven Prandtl-Reuss perfect plasticity are considered limit passage. Keywords: Thermodynamics, Prandtl-Reuss plasticity, Kelvin-Voigt rheology, thermal
Fluid = particles A Conservative Numerical Scheme
Al Hanbali, Ahmad
of this continuum formulation will 'directly' lead to a discrete Hamiltonian scheme: HPM. · alternative is fully Lagrangian description, which can be discretized into SPH. · both HPM and SPH require some sort of smoothing to maintain accuracy over long-time integrations. Eulerian grid in HPM allows for efficient numerical
RIS-M-2393 GANDALF -A GENERALLY APPLICABLE NUMERICAL DATA
computer languages. INIS descriptors; DATA ACQUISITION; DATA PROCESSING; G CODES; NUMERICAL DATA UDC 681
Applications of Numerical Optimal Control to Nonlinear Hybrid Systems
Zefran, MiloÂ?
, Eaton Corporation, Eden Prairie, Minnesota Abstract This paper develops a technique for numerically
PLUTO: a Numerical Code for Computational Astrophysics
A. Mignone; G. Bodo; S. Massaglia; T. Matsakos; O. Tesileanu; C. Zanni; A. Ferrari
2007-03-12T23:59:59.000Z
We present a new numerical code, PLUTO, for the solution of hypersonic flows in 1, 2 and 3 spatial dimensions and different systems of coordinates. The code provides a multi-physics, multi-algorithm modular environment particularly oriented towards the treatment of astrophysical flows in presence of discontinuities. Different hydrodynamic modules and algorithms may be independently selected to properly describe Newtonian, relativistic, MHD or relativistic MHD fluids. The modular structure exploits a general framework for integrating a system of conservation laws, built on modern Godunov-type shock-capturing schemes. Although a plethora of numerical methods has been successfully developed over the past two decades, the vast majority shares a common discretization recipe, involving three general steps: a piecewise polynomial reconstruction followed by the solution of Riemann problems at zone interfaces and a final evolution stage. We have checked and validated the code against several benchmarks available in literature. Test problems in 1, 2 and 3 dimensions are discussed.
Lattice Boltzmann Model for Numerical Relativity
Ilseven, E
2015-01-01T23:59:59.000Z
In the Bona-Masso formulation, Einstein equations are written as a set of flux conservative first order hyperbolic equations that resemble fluid dynamics equations. Based on this formulation, we construct a lattice Boltzmann model for Numerical Relativity. Our model is validated with well-established tests, showing good agreement with analytical solutions. Furthermore, we show that by increasing the relaxation time, we gain stability at the cost of losing accuracy, and by decreasing the lattice spacings while keeping a constant numerical diffusivity, the accuracy and stability of our simulations improves. Finally, in order to show the potential of our approach a linear scaling law for parallelisation with respect to number of CPU cores is demonstrated. Our model represents the first step in using lattice kinetic theory to solve gravitational problems.
Exploring New Physics Frontiers Through Numerical Relativity
Vitor Cardoso; Leonardo Gualtieri; Carlos Herdeiro; Ulrich Sperhake
2014-09-02T23:59:59.000Z
The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology.
Exploring New Physics Frontiers Through Numerical Relativity
Cardoso, Vitor; Herdeiro, Carlos; Sperhake, Ulrich
2014-01-01T23:59:59.000Z
The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations -- along with some spectacular results -- in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology.
The numerical evaluation of many dimensional integrals
Rhodes, Duane Lewis
1967-01-01T23:59:59.000Z
assistance, and to the members of my committee, Drs. H. A. Luther and R, R. Hocking. TABLE OF CONTENTS Chapter Page I. INTRODUCTION Il. EXISTING METHODS OF NUMERICAL INTEGRATION . 3 Classical Methods Mo nte Carlo Methods . III. AN ERROR ANALYSIS . 10... Derivation of a Criterion. Error Approximation Using the Classical Method . . Error Estimate Using the Crude Monte Carlo Method 10 12 16 IV, EXPERIMENTS WITH CRUDE MONTE CARLO AND THE CLASSICAL METHOD. 18 A Method for Finding Exact Solutions...
Lava Creek Geothermal Area | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOf Kilauea Volcano,Lakefront Tow Tank JumpLatvia: Energy
Issues in Numerical Simulation of Fire Suppression
Tieszen, S.R.; Lopez, A.R.
1999-04-12T23:59:59.000Z
This paper outlines general physical and computational issues associated with performing numerical simulation of fire suppression. Fire suppression encompasses a broad range of chemistry and physics over a large range of time and length scales. The authors discuss the dominant physical/chemical processes important to fire suppression that must be captured by a fire suppression model to be of engineering usefulness. First-principles solutions are not possible due to computational limitations, even with the new generation of tera-flop computers. A basic strategy combining computational fluid dynamics (CFD) simulation techniques with sub-grid model approximations for processes that have length scales unresolvable by gridding is presented.
Numerical Simulations Unravel the Cosmic Web
C. -A. Faucher-Giguere; A. Lidz; L. Hernquist
2008-03-03T23:59:59.000Z
The universe is permeated by a network of filaments, sheets, and knots collectively forming a "cosmic web.'' The discovery of the cosmic web, especially through its signature of absorption of light from distant sources by neutral hydrogen in the intergalactic medium, exemplifies the interplay between theory and experiment that drives science, and is one of the great examples in which numerical simulations have played a key and decisive role. We recount the milestones in our understanding of cosmic structure, summarize its impact on astronomy, cosmology, and physics, and look ahead by outlining the challenges faced as we prepare to probe the cosmic web at new wavelengths.
Numerical modeling of vertical cavity semiconductor lasers
Chow, W.W.; Hadley, G.R.
1996-08-01T23:59:59.000Z
A vertical cavity surface emitting laser (VCSEL) is a diode laser whose optical cavity is formed by growing or depositing DBR mirror stacks that sandwich an active gain region. The resulting short cavity supports lasing into a single longitudinal mode normal to the wafer, making these devices ideal for a multitude of applications, ranging from high-speed communication to high-power sources (from 2D arrays). This report describes the development of a numerical VCSEL model, whose goal is to both further their understanding of these complex devices and provide a tool for accurate design and data analysis.
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries PvtStratosolar Jump to:HoldingsTechintIsNumeric Jump to: navigation, search This is
NEW NUMERICAL TECHNOLOGIES FOR THE SIMULATION OF ARC WELDING PROCESSES
Paris-Sud XI, Université de
NEW NUMERICAL TECHNOLOGIES FOR THE SIMULATION OF ARC WELDING PROCESSES Michel Bellet 1 , Makhlouf Antipolis, France; soudage@transvalor.com Keywords: welding, finite elements, material deposit, adaptive for arc welding simulation and analysis. The new numerical technologies essentially consist first
Numerical simulation of micro-fluidic passive and active mixers
Kumar, Saurabh
2002-01-01T23:59:59.000Z
Numerical simulations of mixing using passive and active techniques are performed. For passive mixing, numerical modeling of a micro-fluidic device, build by Holden and Cremer, was performed. The micro-fluidic device consists of a Y...
Numerical uncertainty in computational engineering and physics
Hemez, Francois M [Los Alamos National Laboratory
2009-01-01T23:59:59.000Z
Obtaining a solution that approximates ordinary or partial differential equations on a computational mesh or grid does not necessarily mean that the solution is accurate or even 'correct'. Unfortunately assessing the quality of discrete solutions by questioning the role played by spatial and temporal discretizations generally comes as a distant third to test-analysis comparison and model calibration. This publication is contributed to raise awareness of the fact that discrete solutions introduce numerical uncertainty. This uncertainty may, in some cases, overwhelm in complexity and magnitude other sources of uncertainty that include experimental variability, parametric uncertainty and modeling assumptions. The concepts of consistency, convergence and truncation error are overviewed to explain the articulation between the exact solution of continuous equations, the solution of modified equations and discrete solutions computed by a code. The current state-of-the-practice of code and solution verification activities is discussed. An example in the discipline of hydro-dynamics illustrates the significant effect that meshing can have on the quality of code predictions. A simple method is proposed to derive bounds of solution uncertainty in cases where the exact solution of the continuous equations, or its modified equations, is unknown. It is argued that numerical uncertainty originating from mesh discretization should always be quantified and accounted for in the overall uncertainty 'budget' that supports decision-making for applications in computational physics and engineering.
GRChombo : Numerical Relativity with Adaptive Mesh Refinement
Katy Clough; Pau Figueras; Hal Finkel; Markus Kunesch; Eugene A. Lim; Saran Tunyasuvunakool
2015-03-11T23:59:59.000Z
Numerical relativity has undergone a revolution in the past decade. With a well-understood mathematical formalism, and full control over the gauge modes, it is now entering an era in which the science can be properly explored. In this work, we introduce GRChombo, a new numerical relativity code written to take full advantage of modern parallel computing techniques. GRChombo's features include full adaptive mesh refinement with block structured Berger-Rigoutsos grid generation which supports non-trivial "many-boxes-in-many-boxes" meshing hierarchies, and massive parallelism through the Message Passing Interface (MPI). GRChombo evolves the Einstein equation with the standard BSSN formalism, with an option to turn on CCZ4 constraint damping if required. We show that GRChombo passes all the standard "Apples-to-Apples" code comparison tests. We also show that it can stably and accurately evolve vacuum black hole spacetimes such as binary black hole mergers, and non-vacuum spacetimes such as scalar collapses into black holes. As an illustration of its AMR capability, we demonstrate the evolution of triple black hole merger, which can be set up trivially in GRChombo.
GRChombo : Numerical Relativity with Adaptive Mesh Refinement
Clough, Katy; Finkel, Hal; Kunesch, Markus; Lim, Eugene A; Tunyasuvunakool, Saran
2015-01-01T23:59:59.000Z
Numerical relativity has undergone a revolution in the past decade. With a well-understood mathematical formalism, and full control over the gauge modes, it is now entering an era in which the science can be properly explored. In this work, we introduce GRChombo, a new numerical relativity code written to take full advantage of modern parallel computing techniques. GRChombo's features include full adaptive mesh refinement with block structured Berger-Rigoutsos grid generation which supports non-trivial "many-boxes-in-many-boxes" meshing hierarchies, and massive parallelism through the Message Passing Interface (MPI). GRChombo evolves the Einstein equation with the standard BSSN formalism, with an option to turn on CCZ4 constraint damping if required. We show that GRChombo passes all the standard "Apples-to-Apples" code comparison tests. We also show that it can stably and accurately evolve vacuum black hole spacetimes such as binary black hole mergers, and non-vacuum spacetimes such as scalar collapses into b...
Numerical Results for the Blue Phases
G. P. Alexander; J. M. Yeomans
2009-06-04T23:59:59.000Z
We review recent numerical work investigating the equilibrium phase diagram, and the dynamics, of the cholesteric blue phases. In equilibrium numerical results confirm the predictions of the classic analytical theories, and extend them to incorporate different values of the elastic constants, or the effects of an applied electric field. There is a striking increase in the stability of blue phase I in systems where the cholesteric undergoes helical sense inversion, and the anomalous electrostriction observed in this phase is reproduced. Solving the equations of motion allows us to present results for the phase transition kinetics of blue phase I under dielectric or flexoelectric coupling to an applied electric field. We also present simulations of the blue phases in a flow field, showing how the disclination network acts to oppose the flow. The results are based on the Landau-de Gennes exapnsion of the liquid crystal free energy: that such a simple and elegant theory can predict such complex and subtle physical behaviour is remarkable.
RELAP-7 Numerical Stabilization: Entropy Viscosity Method
R. A. Berry; M. O. Delchini; J. Ragusa
2014-06-01T23:59:59.000Z
The RELAP-7 code is the next generation nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). The code is based on the INL's modern scientific software development framework, MOOSE (Multi-Physics Object Oriented Simulation Environment). The overall design goal of RELAP-7 is to take advantage of the previous thirty years of advancements in computer architecture, software design, numerical integration methods, and physical models. The end result will be a reactor systems analysis capability that retains and improves upon RELAP5's capability and extends the analysis capability for all reactor system simulation scenarios. RELAP-7 utilizes a single phase and a novel seven-equation two-phase flow models as described in the RELAP-7 Theory Manual (INL/EXT-14-31366). The basic equation systems are hyperbolic, which generally require some type of stabilization (or artificial viscosity) to capture nonlinear discontinuities and to suppress advection-caused oscillations. This report documents one of the available options for this stabilization in RELAP-7 -- a new and novel approach known as the entropy viscosity method. Because the code is an ongoing development effort in which the physical sub models, numerics, and coding are evolving, so too must the specific details of the entropy viscosity stabilization method. Here the fundamentals of the method in their current state are presented.
Symbolic Numeric Index Analysis Algorithm for Differential Algebraic Equations
Linninger, Andreas A.
. For the numerical solution of BVPs, global methods such as orthogonal collocation,1 finite elements,2 or spectral
Numerical simulations for nodal domains and spectral minimal partitions
Vial, Grégory
unpublished results of [HHO2] with efficient numerical computations. This is the main goal of this paper
Upcoming Numerical Linear Algebra Issues in Systems and Control Theory
Upcoming Numerical Linear Algebra Issues in Systems and Control Theory Paul Van Dooren University in the interdisciplinary area of numerical linear algebra and systems and control theory. Although we do not claimto, and normalized coprime factorizations in robust control. Key words. Numerical algorithms, linear algebra, sparse
Upcoming Numerical Linear Algebra Issues in Systems and Control Theory
Upcoming Numerical Linear Algebra Issues in Systems and Control Theory Paul Van Dooren University in the interdisciplinary area of numerical linear algebra and systems and control theory. Although we do not claim, and normalized coprime factorizations in robust control. Key words. Numerical algorithms, linear algebra, sparse
Heft 87 Olaf Cirpka CONTRACT: A Numerical Tool
Cirpka, Olaf Arie
Heft 87 Olaf Cirpka CONTRACT: A Numerical Tool for Contaminant Transport and Chemical Transformations #12;Heft 87 CONTRACT: A Numerical Tool for Contaminant Transport and Chemical Transformations der UniversitÃ¤t Stuttgart #12;CONTRACT: A Numerical Tool for Contaminant Transport and Chemical
On the Numerical Simulation of Waterflooding of Heterogeneous
Douglas Jr., Jim
On the Numerical Simulation of Waterflooding of Heterogeneous Petroleum Reservoirs Jim Douglas, Jr displacement in petroleum reservoirs. A very detailed description of the numerical method is presented. Follow, 22290 Rio de Janeiro, RJ, Brazil #12; On the Numerical Simulation of Waterflooding of Heterogeneous
Numerical Simulation of Unsteady Three-Dimensional Sheet Cavitation
Twente, Universiteit
Numerical Simulation of Unsteady Three-Dimensional Sheet Cavitation A.H. Koop #12;Numerical Simulation of Unsteady Three-Dimensional Sheet Cavitation A.H. Koop Thesis University of Twente, Enschede, the Netherlands #12;NUMERICAL SIMULATION OF UNSTEADY THREE-DIMENSIONAL SHEET CAVITATION PROEFSCHRIFT ter
Paris-Sud XI, Université de
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS Int. J. Numer. Anal Methods in Geomechanics (2012) 19 pages" DOI : 10.1002/nag.1138 #12;2 B. NEDJAR AND R. LE ROY asymptotic
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth. Fluids 2013; 71:175184
Navon, Michael
laser heat deposition on the flow field near shock crossing. The influence of energy impulse was imi.1002/fld.3652 Numerical control of two-dimensional shock waves in dual solution domain by instant reflections in the dual solution domain is addressed in an optimization statement. The gradient
A numerical approximation to distribution function
Tuttle, Keith Allan
1977-01-01T23:59:59.000Z
then is to approximate F(Y) numerically. We sub- divide the unit cube Q into N cubes eqch of length h I/N on a n n side. Within each individual subcube Q , we will define an affine approximation to f, W = g(x , . . . , x ), which requires the gradient of 1' ' 'n our... & h/2, k k i + 1/2 2 n k k = 1, 2, . . . , n]. Let f(x) f C [Q ] the space of twice continuously n differentiable functions on Q , and define the auxiliary function g(x) as the tangent to f at x. i + 1 2 for x f Q. . That is, if x I Q i (x) f (x1 2...
NUMERICAL MODELING OF CATHODE CONTACT MATERIAL DENSIFICATION
Koeppel, Brian J.; Liu, Wenning N.; Stephens, Elizabeth V.; Khaleel, Mohammad A.
2011-11-01T23:59:59.000Z
Numerical modeling was used to simulate the constrained sintering process of the cathode contact layer during assembly of solid oxide fuel cells (SOFCs). A finite element model based on the continuum theory for sintering of porous bodies was developed and used to investigate candidate low-temperature cathode contact materials. Constitutive parameters for various contact materials under investigation were estimated from dilatometry screening tests, and the influence of processing time, processing temperature, initial grain size, and applied compressive stress on the free sintering response was predicted for selected candidate materials. The densification behavior and generated stresses within a 5-cell planar SOFC stack during sintering, high temperature operation, and room temperature shutdown were predicted. Insufficient constrained densification was observed in the stack at the proposed heat treatment, but beneficial effects of reduced grain size, compressive stack preload, and reduced thermal expansion coefficient on the contact layer densification and stresses were observed.
Dynamics of Dry Friction: A Numerical Investigation
Y. F. Lim; Kan Chen
1998-03-18T23:59:59.000Z
We perform extended numerical simulation of the dynamics of dry friction, based on a model derived from the phenomenological description proposed by T. Baumberger et al.. In the case of small deviation from the steady sliding motion, the model is shown to be equivalent to the state- and rate-dependent friction law which was first introduced by Rice and Ruina on the basis of experiments on rocks. We obtain the dynamical phase diagram that agrees well with the experimental results on the paper-on-paper systems. In particular, the bifurcation between stick-slip and steady sliding are shown to change from a direct (supercritical) Hopf type to an inverted (subcritical) one as the driving velocity increases, in agreement with the experiments.
Very high numerical aperture light transmitting device
Allison, Stephen W. (Knoxville, TN); Boatner, Lynn A. (Oak Ridge, TN); Sales, Brian C. (Knoxville, TN)
1998-01-01T23:59:59.000Z
A new light-transmitting device using a SCIN glass core and a novel calcium sodium cladding has been developed. The very high index of refraction, radiation hardness, similar solubility for rare earths and similar melt and viscosity characteristics of core and cladding materials makes them attractive for several applications such as high-numerical-aperture optical fibers and specialty lenses. Optical fibers up to 60 m in length have been drawn, and several simple lenses have been designed, ground, and polished. Preliminary results on the ability to directly cast optical components of lead-indium phosphate glass are also discussed as well as the suitability of these glasses as a host medium for rare-earth ion lasers and amplifiers.
Direct numerical simulation of turbulent reacting flows
Chen, J.H. [Sandia National Laboratories, Livermore, CA (United States)
1993-12-01T23:59:59.000Z
The development of turbulent combustion models that reflect some of the most important characteristics of turbulent reacting flows requires knowledge about the behavior of key quantities in well defined combustion regimes. In turbulent flames, the coupling between the turbulence and the chemistry is so strong in certain regimes that is is very difficult to isolate the role played by one individual phenomenon. Direct numerical simulation (DNS) is an extremely useful tool to study in detail the turbulence-chemistry interactions in certain well defined regimes. Globally, non-premixed flames are controlled by two limiting cases: the fast chemistry limit, where the turbulent fluctuations. In between these two limits, finite-rate chemical effects are important and the turbulence interacts strongly with the chemical processes. This regime is important because industrial burners operate in regimes in which, locally the flame undergoes extinction, or is at least in some nonequilibrium condition. Furthermore, these nonequilibrium conditions strongly influence the production of pollutants. To quantify the finite-rate chemistry effect, direct numerical simulations are performed to study the interaction between an initially laminar non-premixed flame and a three-dimensional field of homogeneous isotropic decaying turbulence. Emphasis is placed on the dynamics of extinction and on transient effects on the fine scale mixing process. Differential molecular diffusion among species is also examined with this approach, both for nonreacting and reacting situations. To address the problem of large-scale mixing and to examine the effects of mean shear, efforts are underway to perform large eddy simulations of round three-dimensional jets.
Force budget: I. Theory and numerical methods
van der Veen, Cornelis J.; Whillans, I. M.
1989-10-05T23:59:59.000Z
,y) and vertical (z). Balance of forces is expressed by: 8 h- J Rxxdz8x b ~ 8 h ~ Rxx(h)- + - J Rxydz - Rxy(h)-8 +8x 8y yb (11 ) 8C1XX 8C1xy 8C1xz + + 0 (1)8x 8y 8z 8C1xy 8C1yy 8C1yz 0 (2)+ +8x 8y 8z 8 h 8x J Rxydz b (12) 8C1XZ 8C1yz 8C1ZZ + + ---- - pg = 0 (3)8x 8... are small compared to pg. This is satisfied if 8Rxz/ax = aC1xz/aX * 0 and 8Ryz/ay = aC1yz/ay * O.When the balance equations are solved numerically, this approximation is not necessary, and the value of Rzz can be obtained from Equation (3) for vertical force...
Direct numerical simulations of convective heat transfer
Pointel, G.; Acharya, S.; Sharma, C. [Louisiana State Univ., Baton Rouge, LA (United States). Mechanical Engineering Dept.
1996-11-01T23:59:59.000Z
This paper deals with the development of a direct numerical simulation (DNS) code for solving the incompressible Navier-Stokes equation using higher order finite difference schemes. The time dependent Navier Stokes equation has been discretized using semi-implicit second order time splitting scheme, which requires the solution of pressure Poisson equation. For this purpose a Galerkin Fourier transform in the spanwise direction and a matrix diagonalization technique is used. The convection terms are formulated in non-conservative form on a collocated grid. A fifth order upwind biased scheme is used for this purpose. Diffusion terms are differenced using a sixth order central difference scheme. The algorithm is implemented on the MasPar MP-1, a Single Instruction Multiple Data computer where efficient data parallelization is used to get DNS results. The code has been used to get results for smooth channel flow at Re{sub {tau}} = 180. Results are now being obtained for the energy equation and for flow in a periodic ribbed channel.
A numerical model of aerosol scavenging
Bradley, M.M.; Molenkamp, C.R.
1991-10-01T23:59:59.000Z
Using a three-dimensional numerical cloud/smoke-plume model, we have simulated the burning of a large, mid-latitude city following a nuclear exchange. The model includes 18 dynamic and microphysical equations that predict the fire-driven airflow, cloud processes, and smoke-cloud interactions. In the simulation, the intense heating from the burning city produces a firestorm with updraft velocities exceeding 60 m/s. Within 15 minutes of ignition, the smoke plume penetrates the tropopause. The updraft triggers a cumulonimbus cloud that produces significant quantities of ice, snow, and hail. These solid hydrometeors, as well as cloud droplets and rain, interact with the smoke particles from the fire. At the end of the one-hour simulation, over 20% of the smoke is in slowly falling snowflakes. If the snow reaches the ground before the flakes completely sublimate (or melt and then evaporate), then only approximately 50% of the smoke will survive the scavenging processes and remain in the atmosphere to affect the global climate.
Collisionless microinstabilities in stellarators. II. Numerical simulations
Proll, J. H. E.; Xanthopoulos, P.; Helander, P. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, Wendelsteinstraße 1, 17491 Greifswald, Germany and Max-Planck/Princeton Research Center for Plasma Physics, 17491 Greifswald (Germany)] [Max-Planck-Institut für Plasmaphysik, EURATOM Association, Teilinstitut Greifswald, Wendelsteinstraße 1, 17491 Greifswald, Germany and Max-Planck/Princeton Research Center for Plasma Physics, 17491 Greifswald (Germany)
2013-12-15T23:59:59.000Z
Microinstabilities exhibit a rich variety of behavior in stellarators due to the many degrees of freedom in the magnetic geometry. It has recently been found that certain stellarators (quasi-isodynamic ones with maximum-J geometry) are partly resilient to trapped-particle instabilities, because fast-bouncing particles tend to extract energy from these modes near marginal stability. In reality, stellarators are never perfectly quasi-isodynamic, and the question thus arises whether they still benefit from enhanced stability. Here, the stability properties of Wendelstein 7-X and a more quasi-isodynamic configuration, QIPC, are investigated numerically and compared with the National Compact Stellarator Experiment and the DIII-D tokamak. In gyrokinetic simulations, performed with the gyrokinetic code GENE in the electrostatic and collisionless approximation, ion-temperature-gradient modes, trapped-electron modes, and mixed-type instabilities are studied. Wendelstein 7-X and QIPC exhibit significantly reduced growth rates for all simulations that include kinetic electrons, and the latter are indeed found to be stabilizing in the energy budget. These results suggest that imperfectly optimized stellarators can retain most of the stabilizing properties predicted for perfect maximum-J configurations.
Status of NINJA: the Numerical INJection Analysis project
Benjamin Aylott; John G. Baker; William D. Boggs; Michael Boyle; Patrick R. Brady; Duncan A. Brown; Bernd Brügmann; Luisa T. Buchman; Alessandra Buonanno; Laura Cadonati; Jordan Camp; Manuela Campanelli; Joan Centrella; Shourov Chatterjis; Nelson Christensen; Tony Chu; Peter Diener; Nils Dorband; Zachariah B. Etienne; Joshua Faber; Stephen Fairhurst; Benjamin Farr; Sebastian Fischetti; Gianluca Guidi; Lisa M. Goggin; Mark Hannam; Frank Herrmann; Ian Hinder; Sascha Husa; Vicky Kalogera; Drew Keppel; Lawrence E. Kidder; Bernard J. Kelly; Badri Krishnan; Pablo Laguna; Carlos O. Lousto; Ilya Mandel; Pedro Marronetti; Richard Matzner; Sean T. McWilliams; Keith D. Matthews; R. Adam Mercer; Satyanarayan R. P. Mohapatra; Abdul H. Mroué; Hiroyuki Nakano; Evan Ochsner; Yi Pan; Larne Pekowsky; Harald P. Pfeiffer; Denis Pollney; Frans Pretorius; Vivien Raymond; Christian Reisswig; Luciano Rezzolla; Oliver Rinne; Craig Robinson; Christian Röver; Lucía Santamaría; Bangalore Sathyaprakash; Mark A. Scheel; Erik Schnetter; Jennifer Seiler; Stuart L. Shapiro; Deirdre Shoemaker; Ulrich Sperhake; Alexander Stroeer; Riccardo Sturani; Wolfgang Tichy; Yuk Tung Liu; Marc van der Sluys; James R. van Meter; Ruslan Vaulin; Alberto Vecchio; John Veitch; Andrea Viceré; John T. Whelan; Yosef Zlochower
2009-05-26T23:59:59.000Z
The 2008 NRDA conference introduced the Numerical INJection Analysis project (NINJA), a new collaborative effort between the numerical relativity community and the data analysis community. NINJA focuses on modeling and searching for gravitational wave signatures from the coalescence of binary system of compact objects. We review the scope of this collaboration and the components of the first NINJA project, where numerical relativity groups shared waveforms and data analysis teams applied various techniques to detect them when embedded in colored Gaussian noise.
Numerical simulation of three-dimensional electrical flow through geomaterials
Akhtar, Anwar Saeed
1998-01-01T23:59:59.000Z
95 99 V ELECTRICAL FLOW AROUND AN ELECTRICAL CONE PENETROMETER 104 5. 1 INTRODUCTION 5. 2 ANALYTICAL SOLUTION FOR ELECTRICAL FLOW AROUND AN ELECTRICAL CONE PENETROMETER 5. 3 NUMERICAL INVESTIGATION 5. 4 COMPARISON OF ANALYTICAL AND NUMERICAL... RESULTS 5. 5 CONCLUSION AND APPLICATION 5. 5. 1 Utilization of Numerical Results 104 106 110 113 115 116 VI EXPERIMENTAL EQUIPMENT DESIGN 121 6. 1 INTRODUCTION 6. 2 ELECTRICAL POWER SOURCE 6. 3 ELECTRICAL RESISTIVITY CONE PENETROMETER 6. 4...
Efficient numerical methods for computing ground states and ...
2010-08-06T23:59:59.000Z
Jul 8, 2010 ... New efficient and accurate numerical methods are proposed to ... ating integrals with high singularity and thus they are more efficient and ...
A Numerical Evaluation Of Electromagnetic Methods In Geothermal...
Published Journal International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1996 DOI 10.1016S0148-9062(97)87449-9 Citation . 1996. A Numerical...
Numerical Methods for Transport{Dominated Flows in ...
Numerical Methods for Transport{Dominated Flows in. Heterogeneous Porous Media. Jim Douglas, Jr. Frederico Furtado y. Felipe Pereira z. Li-Ming Yeh x.
Numerical Modeling At Dixie Valley Geothermal Area (McKenna ...
McKenna & Blackwell, 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Numerical Modeling At Dixie Valley Geothermal Area (McKenna &...
adaptive numerical methods: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Websites Summary: An adaptive numerical method for the Richards equation with root growth Olga Wilderotter and plant root growth is presented. It allows the calculation of the...
Energy stable schemes and numerical simulations of two phase ...
Title: Energy stable schemes and numerical simulations of two phase complex fluids by the phase-field method Abstact: We present an energetic variational ...
An Integrated Experimental and Numerical Study: Developing a...
and natural geothermal systems. The simulator can also be used to evaluate long-term CO2 sequestration potentials. State Minnesota Objectives Modify a numerical simulator (TOUGH2)...
Numerical study of reaction in porous catalysts under composition modulation
Hsiao, Hsu-Wen
2010-01-01T23:59:59.000Z
Numerical methods for chemical engineering: applications incycling of the feed." Chemical Engineering Science 54(20): [computer." Computers & Chemical Engineering 26(3): 439-
Numerical Data Advisory Board assembly of mathematial and physical sciences
Not Available
1980-07-30T23:59:59.000Z
The Numerical Data Advisory Board (NDAB) is an advisory body that provides expert overview, on a broad basis, of data needs and data programs as required for the advancement of science and technology. Board members, representing various disciplines, concern themselves with the quality, reliability, availability, accessibility, and dissemination of numerical data in physical, chemical, engineering, and interdisciplinary subjects as well as numeric and non-numeric data that arise in biology and geology. Topics of concern are addressed by the NDAB membership, or by specific, carefully chosen committees and panels established by NDAB in order to include experts appropriate to the subject at hand.
adaptive numerical dissipative: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
linear function while the frictional dissipation rate is a cubic power of surface wind speed, the dissipation rate is generally smaller Wang, Yuqing 7 An Adaptive Numerical...
Numerical Modeling of the Nucleation Conditions of Petal-Centerline...
Coso Geothermal Field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: Numerical Modeling of the Nucleation Conditions of...
Optimization Online - On mutual impact of numerical linear algebra ...
Marco D'Apuzzo
2008-03-12T23:59:59.000Z
Mar 12, 2008 ... On mutual impact of numerical linear algebra and large-scale optimization with focus on interior point methods.
The Numerical Approximation of Solutions of ... - Purdue University
2009-05-05T23:59:59.000Z
numerical simulation of waterflooding of heterogeneous petroleum reservoirs. Computational Geosciences, 1 (1997). 155–190. J. Douglas, Jr., C.-S. Huang, and ...
Preliminary LSG Numerical Reliability DATt 5 January 1971
Rathbun, Julie A.
of the component application analysis and the FMEA. I . f.: I #12;· .... ATM-937 HY.MO. Preliminary l.SG Numerical
Practical Experience in the Numerical Dangers of Heterogeneous Computing
Dongarra, Jack
in writing reliable numerical library software for heterogeneous computing environments. Although a lot ways to avoid potential pitfalls, or if that is not possible, we recommend that the software;1. INTRODUCTION There are special challenges associated with writing reliable numerical software on networks
A new shock-capturing numerical scheme for ideal hydrodynamics
Zuzana Feckova; Boris Tomasik
2015-01-07T23:59:59.000Z
We present a new algorithm for solving ideal relativistic hydrodynamics based on Godunov method with an exact solution of Riemann problem for an arbitrary equation of state. Standard numerical tests are executed, such as the sound wave propagation and the shock tube problem. Low numerical viscosity and high precision are attained with proper discretization.
A new shock-capturing numerical scheme for ideal hydrodynamics
Feckova, Zuzana
2015-01-01T23:59:59.000Z
We present a new algorithm for solving ideal relativistic hydrodynamics based on Godunov method with an exact solution of Riemann problem for an arbitrary equation of state. Standard numerical tests are executed, such as the sound wave propagation and the shock tube problem. Low numerical viscosity and high precision are attained with proper discretization.
Numerical Analysis of Nonlinear Multiharmonic Eddy Current Problems
Schoeberl, Joachim
Numerical Analysis of Nonlinear Multiharmonic Eddy Current Problems F. Bachinger U. Langer J. Sch¨oberl April 2004 Abstract This work provides a complete analysis of eddy current problems, rang- ing from at providing a complete analysis of general nonlinear eddy current problems and their numerical treatment
Numerical integration and importance 2.1 Quadrature
Schofield, Jeremy
2 Numerical integration and importance sampling 2.1 Quadrature Consider the numerical evaluation of the integral I(a, b) = b a dx f(x) · Rectangle rule: on small interval, construct interpolating function and integrate over interval. Polynomial of degree 0 using mid-point of interval: (a+1)h ah dx f(x) h f ((ah
Buoyant melting instabilities beneath extending lithosphere: 1. Numerical models
Tackley, Paul J.
Buoyant melting instabilities beneath extending lithosphere: 1. Numerical models John W. Hernlund,1,2 Paul J. Tackley,1,3 and David J. Stevenson4 Received 18 November 2006; revised 18 October 2007 diffusely extending lithosphere is studied using numerical convection models covering a wide range
A Numerical Investigation of Wettability Alteration during Immiscible CO2
Hossain, M. Enamul
A Numerical Investigation of Wettability Alteration during Immiscible CO2 Flooding Process, April 2012 #12;2 Table of Contest Abstract 3 Introduction 3 Literature Review 5 CO2 Flooding 7 New alteration during CO2 flooding. However, limited research on numerical and/or analytical modeling
A Numerical quadrature for the Schwarz-Chimera Method
A Numerical quadrature for the Schwarz-Chimera Method J. -B. Apoung Kamga1 and Olivier Pironneau2 1 Curie Olivier.Pironneau@upmc.fr Summary. Chimera [9] happens to be a version of Schwarz' method quadrature for the Schwarz-Chimera Method 3 3 Numerical Quadrature As such, the scheme is too costly
Numerical simulation of transpiration cooling through porous , T. Gotzen1
55, 52056 Aachen SUMMARY Transpiration cooling using ceramic matrix composite (CMC) materials to facilitate such numerical simulations for a carbon/carbon material mounted in the side wall of a hot gasNumerical simulation of transpiration cooling through porous material W. Dahmen1 , T. Gotzen1 and S
Richard # 9501 EXPERIMENTAL AND NUMERICAL ANALYSIS OF CORROSION-
Paris-Sud XI, UniversitÃ© de
Richard # 9501 Page 1/9 EXPERIMENTAL AND NUMERICAL ANALYSIS OF CORROSION- INDUCED COVER CRACKING to present both experimental and numerical studies of the corrosion induced cracking pattern evolution of a reinforced concrete sample subjected to accelerated corrosion. The sample was a concrete beam (1000x250x100
Evolution of the Bohemian Massif: Insights from numerical modeling
Cerveny, Vlastislav
Evolution of the Bohemian Massif: Insights from numerical modeling Petra Maierová Supervisor: Doc of Geophysics Faculty of Mathematics and Physics Charles University in Prague #12;February 4, 2013Evolution Conclusions Outline #12;February 4, 2013Evolution of the Bohemian Massif: Insights from numerical modeling 3
CSU ATS703 Fall 2012 Numerical Weather Prediction
CSU ATS703 Fall 2012 Numerical Weather Prediction ATS703 is based on the course notes and papers method. A crucial element of accurate weather prediction is initialization, which is briefly discussed in Chapter 11. In the next decade, numerical weather prediction will expe- rience a revolution in model
KH Computational Physics-2006 Basic Numerical Algorithms Integration
Glashausser, Charles
KH Computational Physics- 2006 Basic Numerical Algorithms Integration Numerical integration competing factors one needs to consider · speed - number of function evaluations or grid points · precision or "smart" meshes with lower order routines Kristjan Haule, 2006 1 #12;KH Computational Physics- 2006
Numerical Simulation in Applied Geophysics. From the Mesoscale to the
Santos, Juan
Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale Juan E. Santos Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale p. #12;Introduction. I layering, fractures and craks at the mesoscale (on the order of centimeters) are common in the earth
NUMERICAL INVESTIGATION OF CAVITATION IN MULTI-DIMENSIONAL COMPRESSIBLE FLOWS
NUMERICAL INVESTIGATION OF CAVITATION IN MULTI-DIMENSIONAL COMPRESSIBLE FLOWS KRISTEN J. DEVAULT, cavitation, pseudospectral AMS subject classifications. 35Q30, 65M70, 76N99 1. Introduction. A long to first make a careful numerical study of the simplest possible scenario where one could expect cavitation
Numerical Simulation of a Natural Circulation Steam Generator
WeinmÃ¼ller, Ewa B.
Numerical Simulation of a Natural Circulation Steam Generator W. Linzer \\Lambda , K. Ponweiser circulation steam generator. We focus on a model with a simple geometry consisting of two vertical pipes properties of water and steam. We present a numerical algorithm based on an explicit upwind discretization
Peirce, Anthony
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS Int. J. Numer. Anal of engineering applications such as pavement design, stress analysis of mining excavations, and hydraulic. In the petroleum industry, hydraulic fractures are deliberately created in oil and gas reservoirs to substantially
Simple intrinsic defects in GaAs : numerical supplement.
Schultz, Peter Andrew
2012-04-01T23:59:59.000Z
This Report presents numerical tables summarizing properties of intrinsic defects in gallium arsenide, GaAs, as computed by density functional theory. This Report serves as a numerical supplement to the results published in: P.A. Schultz and O.A. von Lilienfeld, 'Simple intrinsic defects in GaAs', Modelling Simul. Mater. Sci Eng., Vol. 17, 084007 (2009), and intended for use as reference tables for a defect physics package in device models. The numerical results for density functional theory calculations of properties of simple intrinsic defects in gallium arsenide are presented.
Grid-independent Issue in Numerical Heat Transfer
Yao Wei; Wang Jian; Liao Guangxuan
2006-09-26T23:59:59.000Z
Grid independent is associated with the accuracy or even rationality of numerical results. This paper takes two-dimensional steady heat transfer for example to reveal the effect of grid resolution on numerical results. The law of grid dependence is obtained and a simple mathematical formula is presented. The production acquired here can be used as the guidance in choosing grid density in numerical simulation and get exact grid independent value without using infinite fine grid. Through analyzing grid independent, we can find the minimum number of grid cells that is needed to get grid-independent results. Such strategy can save computational resource while ensure a rational computational result.
Benjamin Aylott; John G. Baker; William D. Boggs; Michael Boyle; Patrick R. Brady; Duncan A. Brown; Bernd Brügmann; Luisa T. Buchman; Alessandra Buonanno; Laura Cadonati; Jordan Camp; Manuela Campanelli; Joan Centrella; Shourov Chatterji; Nelson Christensen; Tony Chu; Peter Diener; Nils Dorband; Zachariah B. Etienne; Joshua Faber; Stephen Fairhurst; Benjamin Farr; Sebastian Fischetti; Gianluca Guidi; Lisa M. Goggin; Mark Hannam; Frank Herrmann; Ian Hinder; Sascha Husa; Vicky Kalogera; Drew Keppel; Lawrence E. Kidder; Bernard J. Kelly; Badri Krishnan; Pablo Laguna; Carlos O. Lousto; Ilya Mandel; Pedro Marronetti; Richard Matzner; Sean T. McWilliams; Keith D. Matthews; R. Adam Mercer; Satyanarayan R. P. Mohapatra; Abdul H. Mroué; Hiroyuki Nakano; Evan Ochsner; Yi Pan; Larne Pekowsky; Harald P. Pfeiffer; Denis Pollney; Frans Pretorius; Vivien Raymond; Christian Reisswig; Luciano Rezzolla; Oliver Rinne; Craig Robinson; Christian Röver; Lucía Santamaría; Bangalore Sathyaprakash; Mark A. Scheel; Erik Schnetter; Jennifer Seiler; Stuart L. Shapiro; Deirdre Shoemaker; Ulrich Sperhake; Alexander Stroeer; Riccardo Sturani; Wolfgang Tichy; Yuk Tung Liu; Marc van der Sluys; James R. van Meter; Ruslan Vaulin; Alberto Vecchio; John Veitch; Andrea Viceré; John T. Whelan; Yosef Zlochower
2009-07-09T23:59:59.000Z
The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave data analysis communities. The purpose of NINJA is to study the sensitivity of existing gravitational-wave search algorithms using numerically generated waveforms and to foster closer collaboration between the numerical relativity and data analysis communities. We describe the results of the first NINJA analysis which focused on gravitational waveforms from binary black hole coalescence. Ten numerical relativity groups contributed numerical data which were used to generate a set of gravitational-wave signals. These signals were injected into a simulated data set, designed to mimic the response of the Initial LIGO and Virgo gravitational-wave detectors. Nine groups analysed this data using search and parameter-estimation pipelines. Matched filter algorithms, un-modelled-burst searches and Bayesian parameter-estimation and model-selection algorithms were applied to the data. We report the efficiency of these search methods in detecting the numerical waveforms and measuring their parameters. We describe preliminary comparisons between the different search methods and suggest improvements for future NINJA analyses.
NUMERICAL SOLUTION OF BIVARIATE AND POLYANALYTIC POLYNOMIAL SYSTEMS
problem in robotics, computer modeling and graphics, computational geometry and numerical optimization. We) the Research Council KU Leuven: (a) OT/10/038, (b) PF/10/002 Optimization in Engineering (OPTEC), (2
NUMERICAL SOLUTION OF BIVARIATE AND POLYANALYTIC POLYNOMIAL SYSTEMS
problem in robotics, computer modeling and graphics, computational geometry and numerical optimization. We) the Research Council KU Leuven: (a) project OT/10/038, (b) CoE EF/05/006 Optimization in Engineering (OPTEC
LONGTIME ENERGY CONSERVATION OF NUMERICAL METHODS FOR OSCILLATORY DIFFERENTIAL EQUATIONS
TÃ¼bingen, UniversitÃ¤t
LONGÂTIME ENERGY CONSERVATION OF NUMERICAL METHODS FOR OSCILLATORY DIFFERENTIAL EQUATIONS ERNSTÂtime energy conservation, secondÂorder symmetric methods, frequency expansion, backward error analysis, Fermi
An investigation of the numerical treatment of condensation
Sasson, Joseph
The simulation of complete condensation continues to challenge the numerical methods currently used for multi-phase flow modeling; especially at low pressures, the change of phase process from a two-phase mixture to liquid ...
Numerical Simulations of Gamma-Ray Burst Explosions
Lazzati, Davide; López-Cámara, Diego
2015-01-01T23:59:59.000Z
Gamma-ray bursts are a complex, non-linear system that evolves very rapidly through stages of vastly different conditions. They evolve from scales of few hundred kilometers where they are very dense and hot to cold and tenuous on scales of parsecs. As such, our understanding of such a phenomenon can truly increase by combining theoretical and numerical studies adopting different numerical techniques to face different problems and deal with diverse conditions. In this review, we will describe the tremendous advancement in our comprehension of the bursts phenomenology through numerical modeling. Though we will discuss studies mainly based on jet dynamics across the progenitor star and the interstellar medium, we will also touch upon other problems such as the jet launching, its acceleration, and the radiation mechanisms. Finally, we will describe how combining numerical results with observations from Swift and other instruments resulted in true understanding of the bursts phenomenon and the challenges still lyi...
Geometric numerical integration of nonholonomic systems and optimal control problems
M. de Leon; D. Martin de Diego; A. Santamaria Merino
2002-12-02T23:59:59.000Z
A geometric derivation of numerical integrators for nonholonomic systems and optimal control problems is obtained. It is based in the classical technique of generating functions adapted to the special features of nonholonomic systems and optimal control problems.
Numerical modelling of hyperbolic conservation laws using bicharacteristics
Hanke-Bourgeois, Martin
volume methods -1- #12;Overview I. Hyperbolic Conservation Laws Theory of bicharacteristics and evolution, bicharacteritsics stability, accuracy, error analysis III. Numerical Experiments: Wave equation system, Euler eqs finite volume methods -2- #12;· airflow · hydraulic schock · meteorological flow Source: efluid
Numerical Simulation Study on Transpired Solar Air Collector
Wang, C.; Guan, Z.; Zhao, X.; Wang, D.
2006-01-01T23:59:59.000Z
The unglazed transpired solar air collector is now a well-recognized solar air heater for heating outside air directly. In this article, researchers introduced numerical simulation tools into the solar air collector research area, analyzed...
Wavelet methods For the numerical simulation of incompressible fluids
Starck, Jean-Luc
Wavelet methods For the numerical simulation of incompressible fluids Erwan Deriaz Erwan Numerik, Seminar February 16th 2006 0-0 #12; Wavelets for the Navier-Stokes equations homogeneous or non homogeneous) With a wavelet discretization: £ ¦ ¨ 2 ©$# £ % ¦ ¨ 2 © & '' ( 1
NUMERICAL MODELING FOR MULTIPHASE INCOMPRESSIBLE FLOW WITH PHASE CHANGE
Abdou, Mohamed
NUMERICAL MODELING FOR MULTIPHASE INCOMPRESSIBLE FLOW WITH PHASE CHANGE Xiao-Yong Luo, Ming-Jiu Ni for multiphase flows. A con- tinuum surface force (CSF) tension model is used in the present cases. Phase change
Direct Numerical Simulation of the Flow in a Pebble Bed
Ward, Paul
2014-06-24T23:59:59.000Z
bed reactors: dust generation and scaling, proceedings of ICAPP 2012, Chicago, June 24–28, 2012 [3] A. Shams, F. Roelofs, EMJ. Komen, E. Baglietto, 2013. “Quasi-direct numerical simulation of a pebble bed configuration. Part I: Flow (velocity...
Numerical Approximations of Stochastic Optimal Stopping and Control Problems
Siska, David
2007-01-01T23:59:59.000Z
We study numerical approximations for the payoff function of the stochastic optimal stopping and control problem. It is known that the payoff function of the optimal stopping and control problem corresponds to the solution ...
Numerical investigation of the heating process inside an industrial furnace
Wolper, Pierre
Numerical investigation of the heating process inside an industrial furnace Proposition: Combined furnace taking into account convective, conductive and radiative heat transfer. The model: Catalysis, Energy Materials, Performance Materials and Recycling. Each business area is divided into market
Nondestructive Testing of Overhead Transmission Lines: Numerical and Experimental Investigation
Kulkarni, Salil Subhash
2011-02-22T23:59:59.000Z
line is the primary reason for absence of a theoretical solution to get the analytical dispersion curves. The numerical results are then verified with experimental tests using a non-contact and broadband laser detection technique. The methodology...
Numerical Simulation Study on Transpired Solar Air Collector
Wang, C.; Guan, Z.; Zhao, X.; Wang, D.
2006-01-01T23:59:59.000Z
The unglazed transpired solar air collector is now a well-recognized solar air heater for heating outside air directly. In this article, researchers introduced numerical simulation tools into the solar air collector research area, analyzed...
Numerical and Experimental Investigation of Tidal Current Energy Extraction
Sun, Xiaojing
2008-01-01T23:59:59.000Z
Numerical and experimental investigations of tidal current energy extraction have been conducted in this study. A laboratory-scale water flume was simulated using commercial computational fluid dynamics (CFD) code FLUENT. ...
CSE/Math 555: Numerical Optimization Techniques Course Announcement
Shontz, Suzanne M.
towards graduate students, researchers and faculty in · computer science and engineering · mathematics portfolios Description: The course will emphasize the design and mathematical analysis of numerical op: unconstrained optimization methods, automatic differentiation, nonlinear equations, constrained optimization
An experimental and numerical study of wind turbine seismic behavior
Prowell, I.
2011-01-01T23:59:59.000Z
3.2.1 Description of Test Wind Turbine . . . . . .Figure 1.2: Components of a modern wind turbine . . . . . .Experimental and Numerical Seismic Response of a 65-kW Wind
Numerical simulation of flow separation control by oscillatory fluid injection
Resendiz Rosas, Celerino
2005-08-29T23:59:59.000Z
and Lomax. The application of synthetic jet actuators is based in their ability to energize the boundary layer, thereby providing signifcant increase in the lift coefficient. This has been corroborated experimentally and it is corroborated numerically...
Householder Symposium on Numerical Linear Algebra June 1721, 2002
Higham, Nicholas J.
for discussions. This year's symposium is held at Peebles Hotel Hydro in the small town of Peebles (populationHouseholder Symposium on Numerical Linear Algebra June 17Â21, 2002 Peebles Hotel Hydro, Scotland
Multiscale numerical methods for some types of parabolic equations
Nam, Dukjin
2009-05-15T23:59:59.000Z
method. The goal of the second problem is to develop efficient multiscale numerical techniques for solving turbulent diffusion equations governed by celluar flows. The solution near the separatrices can be approximated by the solution of a system of one...
Prediction of Thermoacoustic Instabilities: Numerical Study of Mach number Effects.
Nicoud, Franck
Prediction of Thermoacoustic Instabilities: Numerical Study of Mach number Effects. K. Wieczorek equations. I. Introduction In the calculation of thermoacoustic instabilities, an assumption lead to significant changes in the evaluation of the thermo-acoustic modes present in the combustion
GEOMETRIC NUMERICAL INTEGRATION OF INEQUALITY CONSTRAINED, NONSMOOTH HAMILTONIAN SYSTEMS
Columbia University
and obtain an associated framework for composing ge- ometric numerical integration methods for inequality-equalityÂconstrained geometric integration setting, we target long-term structure preservation. In the inequality-constrained
Numerical simulation of flow separation control by oscillatory fluid injection
Resendiz Rosas, Celerino
2005-08-29T23:59:59.000Z
In this work, numerical simulations of flow separation control are performed. The sep-aration control technique studied is called 'synthetic jet actuation'. The developed code employs a cell centered finite volume scheme which handles viscous...
Assessment of the MUSTA approach for numerical relativistic dynamics
Blakely, P. M.; Nikiforakis, N.; Henshaw, W. D.
2015-03-04T23:59:59.000Z
waves 1. Introduction The numerical solution of the relativistic hydrodynamical equa- tions is of importance to the simulation of astrophysical phe- nomena such as gamma-ray bursts, supernova core-collapse, and relativistic wind accretion. Although...
2.086 Numerical Computation for Mechanical Engineers, Spring 2012
Patera, Anthony
This class introduces elementary programming concepts including variable types, data structures, and flow control. After an introduction to linear algebra and probability, it covers numerical methods relevant to mechanical ...
Characterization of Lung's Emphysema Distribution: Numerical Assessment of Disease Development
Paris-Sud XI, Université de
Characterization of Lung's Emphysema Distribution: Numerical Assessment of Disease Development M, Egypt. Abstract--Chronic Obstructive Pulmonary Disease (COPD) refers to a group of lung diseases bronchitis. Pulmonary emphysema is defined as a lung disease characterized by "abnormal enlargement
ASYMPTOTIC AND NUMERICAL MODELLING OF FLOWS IN FRACTURED POROUS MEDIA
Paris-Sud XI, Université de
numerical results are reported showing different kinds of flows in the case of impermeable or partially. Joliot Curie, F-13453 Marseille cedex 13. Email : [angot,fboyer,fhubert]@cmi.univ-mrs.fr cl EDP Sciences
Effective velocities in fractured media: a numerical study using the ...
2002-03-18T23:59:59.000Z
theories that predict the effective P- and S-wave velocities in fractured materials in ... can be treated only by numerical techniques because analyt- ... apply the rotated staggered grid (Saenger, Gold and Shapiro ..... (r ? 0:2) and for SH-
Segmented vs conventional numerals: legibility and long term retention
Hill, Steve Edgar
1971-01-01T23:59:59.000Z
SEGMENTED VS CONVENTIONAL NUMERALS: LEGIBILITY AND LONG TERM RETENTION A Thesis by STEVE EDGAR HILL Submitted to the Graduate College of Texas A8cM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 1971 Ma]or Subject: Industrial Engineering SEGMENTED VS CONVENTIONAL NUMERALS: LEGIBILITY AND LONG TERM RETENTION A Thesis STEVE EDGAR HILL Approved as to style and content by: Elias Chairman of Committee) r. A. W. ortham (Head...
Numerical studies of a simple Coulomb blockade model
Shao, Jianfeng
1991-01-01T23:59:59.000Z
NUMERICAL STUDIES OF A SIMPLE COULOMB BLOCKADE MODEL A Thesis by JIANFENG SHAO Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1991... Major Subject: Physics NUMERICAL STUDIES OF A SIMPLE COULOMB BLOCKADE MODEL A Thesis by JIANFENG SHAO Approved as to style and content by: Roland E, Allen (Chair of Committee) /, 1 r oseph H. R s ( Member) Chin B. Su (Member) Richard L...
Numerical simulation of imbibition process in fractured cores
Jiang, Chunhuan
1992-01-01T23:59:59.000Z
of the equations describing the imbibition of pure and carbonated water and the countercurrent flow of oil in porous rocks. Comparison between numerical solutions and experimental observations indicates that the models do simulate water imbibition and the COp.... ~~ +Blair 1964 presented a numerical solution for equations describing oil displacement by countercurrent water imbibition. Calculations were made for water imbibition into both linear and radial systems. Blair studied the effects on imbibition rates as a...
Griebel, Michael
, says: "The power supplies and the cooling systems could not cope with the constant heavy loads of data computer networks supplied by specialist organisations have performed the institute's numerical simulation
Chimera: A hybrid approach to numerical loop quantum cosmology
Diener, Peter; Singh, Parampreet
2013-01-01T23:59:59.000Z
The existence of a quantum bounce in isotropic spacetimes is a key result in loop quantum cosmology (LQC), which has been demonstrated to arise in all the models studied so far. In most of the models, the bounce has been studied using numerical simulations involving states which are sharply peaked and which bounce at volumes much larger than the Planck volume. An important issue is to confirm the existence of the bounce for states which have a wide spread, or which bounce closer to the Planck volume. Numerical simulations with such states demand large computational domains, making them very expensive and practically infeasible with the techniques which have been implemented so far. To overcome these difficulties, we present an efficient hybrid numerical scheme using the property that at the small spacetime curvature, the quantum Hamiltonian constraint in LQC, which is a difference equation with uniform discretization in volume, can be approximated by a Wheeler-DeWitt differential equation. By carefully choosi...
Numerical simulation of water flow around a rigid fishing net
Roger Lewandowski; Géraldine Pichot
2006-12-20T23:59:59.000Z
This paper is devoted to the simulation of the flow around and inside a rigid axisymmetric net. We describe first how experimental data have been obtained. We show in detail the modelization. The model is based on a Reynolds Averaged Navier-Stokes turbulence model penalized by a term based on the Brinkman law. At the out-boundary of the computational box, we have used a "ghost" boundary condition. We show that the corresponding variational problem has a solution. Then the numerical scheme is given and the paper finishes with numerical simulations compared with the experimental data.
Numerical Analysis of Spherically Convergent Rayleigh-Taylor Experiments
Galmiche, D.; Cherfils, C.; Glendinning, S.G.; Remington, B.A.; Richard, A.
2000-05-17T23:59:59.000Z
In the frame of a CEA/US DOE collaboration, radiation driven spherically convergent experiments were performed on the Nova laser in order m measure the Rayleigh-Taylor growth at the ablation front. Numerical simulations using the 2D Lagrangian code FCI2 have correctly reproduced experiments in moderate convergent geometry. [C. Cherfils et al., PRL 83, 5507 (1999)]. Experiments have addressed convergence ratios up to 4 by considering larger capsules, larger hohlraum and longer laser pulses [S.G. Glendinning et al., to be published in Physics of Plasmas]. Numerical analysis of these high convergence implosions is presented, and the effect of convergence on the Rayleigh-Taylor growth is investigated.
ATS 680 A6: Applied Numerical Weather Prediction MW, 1:00-1:50 PM, ACRC Room 212B
, Parameterization Schemes: Keys to Understanding Numerical Weather Prediction Models, Cambridge University Press in class. Numerical model The primary numerical model that will be u
Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions
Peirce, Anthony
Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions SANUM Conference (UMN) Eduard Siebrits (SLB) #12;2 Outline Â· Examples of hydraulic fractures Â· Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1
Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions
Peirce, Anthony
Hydraulic Fractures: multiscale phenomena, asymptotic and numerical solutions CSIRO CSS TCP Detournay (UMN) Eduard Siebrits (SLB) #12;2 Outline Â· Examples of hydraulic fractures Â· Governing equations well stimulation Fracturing Fluid Proppant #12;5 Quarries #12;6 Magma flow Tarkastad #12;7 Model EQ 1
Numerical Model of a Tensioner System and Flex Joint
Huang, Han
2013-07-27T23:59:59.000Z
Top Tensioned Riser (TTR) and Steel Catenary Riser (SCR) are often used in a floating oil/gas production system deployed in deep water for oil transport. This study focuses on the improvements to the existing numerical code, known as CABLE3D...
Pyrolysis in Porous Media: Numerical Analysis and Comparison to Experiments.
Paris-Sud XI, Université de
by the combustor [7,8]. Carbon- or oxide-based composite materials are preferred for thermal, mechanical components in aerospace vehicles such as combustors in rocket engines. The numerical simulation = activation energy (J.mol-1 ) H = enthalpy of reaction (J.mol-1 ) effk = effective thermal conductivity
Numerical Construction of Likelihood Distributions and the Propagation of Errors
J. Swain; L. Taylor
1997-12-12T23:59:59.000Z
The standard method for the propagation of errors, based on a Taylor series expansion, is approximate and frequently inadequate for realistic problems. A simple and generic technique is described in which the likelihood is constructed numerically, thereby greatly facilitating the propagation of errors.
Simple intrinsic defects in InAs : numerical predictions.
Schultz, Peter Andrew
2013-03-01T23:59:59.000Z
This Report presents numerical tables summarizing properties of intrinsic defects in indium arsenide, InAs, as computed by density functional theory using semi-local density functionals, intended for use as reference tables for a defect physics package in device models.
Numerical Convergence Properties of Option Pricing PDEs with Uncertain Volatility
Forsyth, Peter A.
is then simply the cost of this hedge. The principal source of risk is the price of the underlying assetNumerical Convergence Properties of Option Pricing PDEs with Uncertain Volatility D. M. Pooley , P, 2001 Abstract The pricing equations derived from uncertain volatility models in finance are often cast
NUMERICAL SIMULATIONS OF ROTATING SUNSPOTS G. J. J. Botha1
Rucklidge, Alastair
, at a depth of 0 to 5 Mm there exist subsurface horizontal vortical flows, while there are also suggestions's convection zone. The solution forms a central flux tube in the cylindrical numerical domain, with convection, vortical flow. As a result, the azimuthal velocity and mag- netic field have their maximum values close
Friction versus dilation revisited: Insights from theoretical and numerical models
Einat, Aharonov
Friction versus dilation revisited: Insights from theoretical and numerical models N. Makedonska,1 controlled by the frictional strength of the fault gouge, a granular layer that accumulates between the fault friction coefficient) of such granular layers is the systems resistance to dilation, a byprocess
Numerical studies of the metamodel fitting and validation processes
Boyer, Edmond
algorithms and application to a nuclear safety computer code show the relevance of this new sequential this problem consists in replacing cpu time expensive computer models by cpu inexpensive mathematical functions to fit the metamodel) has to provide adequate space filling properties. We adopt a numerical approach
Diffusion and Dispersion Characterization of a Numerical Tsunami Model
Tolkova, Elena
and numerical model. This plan is currently under devel- opment at the NCTR and a proof of concept has been-computed database of unit source solutions to determine the offshore tsunami waves. It then uses the MOST model (in nested grid mode) to propagate the offshore waves onshore for select regions. The critical factor
Efficient Numerical Simulation for Long Range Wave Propagation 1
Solna, Knut
Efficient Numerical Simulation for Long Range Wave Propagation 1 Kai Huang 2 George Papanicolaou 3 for simulating wave propagation over long dis- tances with both weak and strong scatterers. In domains with weak heterogeneities the wave field is decomposed into forward propagating and back scattered modes using two coupled
Numerical algorithms for the computation of the Smith normal
Seberry, Jennifer
Numerical algorithms for the computation of the Smith normal form of integral matrices C of the Smith normal form of integral matrices are described. More specifically, the comÂ pound matrix method of the algorithms. AMS Subject Classification: Primary 65F30, Secondary 15A21, 15A36. Key words and phrases: Smith
Numerical simulation of cooling gas injection using adaptive multiscale techniques
Numerical simulation of cooling gas injection using adaptive multiscale techniques Wolfgang Dahmen is investigated. Keywords: Finite Volume Method, Film cooling, Cooling gas injection, Multiscale techniques, Grid Mathematik, RWTH Aachen, Templergraben 55, 52056 Aachen Abstract The interaction of a jet of cooling gas
Numerical Simulation of Wave Loads on Static Offshore Structures
of Wave Loads on Static Offshore Structures Â p. #12;VOF Free Surface Flow Model Modelling of Free Surface-cell resolution of prescribed wave forms in relaxation zones Â· Support for dynamic mesh with 6-DOF solver meshNumerical Simulation of Wave Loads on Static Offshore Structures Hrvoje Jasak, Inno Gatin, Vuko
Translation and integration of numerical atomic orbitals in linear molecules
Heinäsmäki, Sami, E-mail: sami.heinasmaki@gmail.com [Department of Physics, University of Oulu, FIN-90014, Oulu (Finland)] [Department of Physics, University of Oulu, FIN-90014, Oulu (Finland)
2014-02-14T23:59:59.000Z
We present algorithms for translation and integration of atomic orbitals for LCAO calculations in linear molecules. The method applies to arbitrary radial functions given on a numerical mesh. The algorithms are based on pseudospectral differentiation matrices in two dimensions and the corresponding two-dimensional Gaussian quadratures. As a result, multicenter overlap and Coulomb integrals can be evaluated effectively.
Numerical integration of functions originating from quantum mechanics
Armiento, Rickard
Numerical integration of functions originating from quantum mechanics R. Armiento Department Applications in quantum physics commonly involve large batches of integrals of smooth but very oscillatory for evaluating such integrals. The routines studied include: two from the QUADPACK package based on Gauss
Breakdown of analyticity: From rigorous results to numerics
Doedel, Eusebius
work with Rafael de la Llave #12;Computing the breakdown Quasi-Periodic Solutions Outline QuasiBreakdown of analyticity: From rigorous results to numerics Renato Calleja Applied Mathematics-Periodic Solutions Twist Maps Models arising in Statistical Mechanics Computation of the Breakdown Small divisors
Numerical simulation of the truss spar 'Horn Mountain' using COUPLE
Theckum Purath, Basil
2006-08-16T23:59:59.000Z
using an integrated marine monitoring system attached to the truss spar. In this study, dynamic analysis of the truss spar interacting with its mooring and riser system was performed using a time-domain numerical code, known as Â?COUPLEÂ?. The simulated...
A Generic Framework for Interprocedural Analysis of Numerical Properties
MÃ¼ller-Olm, Markus
A Generic Framework for Interprocedural Analysis of Numerical Properties Markus MÂ¨uller-Olm1, Germany markus.mueller-olm@cs.uni-dortmund.de 2 TU MÂ¨unchen, Institut fÂ¨ur Informatik, I2 80333 M of the abstracted collecting semantics is also used by MÂ¨uller-Olm and Seidl in [12] where (in absence of equality
Black hole free energy during charged collapse: a numerical study
Hugues Beauchesne; Ariel Edery
2012-05-19T23:59:59.000Z
We perform a numerical investigation of the thermodynamics during the collapse of a charged (complex) scalar field to a Reissner-Nordstr\\"om (RN) black hole in isotropic coordinates. Numerical work on gravitational collapse in isotropic coordinates has recently shown that the negative of the total Lagrangian approaches the Helmholtz free energy F= E-TS of a Schwarzschild black hole at late times of the collapse (where E is the black hole mass, T the temperature and S the entropy). The relevant thermodynamic potential for the RN black hole is the Gibbs free energy G=E-TS-$\\Phi_H$ Q where Q is the charge and $\\Phi_H$ the electrostatic potential at the outer horizon. In charged collapse, there is a large outgoing matter wave which prevents the exterior from settling quickly to a static state. However, the interior region is not affected significantly by the wave. We find numerically that the interior contribution to the Gibbs free energy is entirely gravitational and accumulates in a thin shell just inside the horizon. The entropy is gravitational in origin and one observes dynamically that it resides on the horizon. We also compare the numerical value of the interior Lagrangian to the expected analytical value of the interior Gibbs free energy for different initial states and we find that they agree to within 10-13%. The two values are approaching each other so that their difference decreases with more evolution time.
IVCNZ 2002 SUBMISSION 1 Pose Estimation by Applied Numerical Techniques
McCane, Brendan
process of how to deform the model in order to bring it into agreement with the input image. An energy. Keywords--- Numerical Optimisation, Pose Estimation, AnalysisÂbyÂSynthesis, Optimisation Algorithms (HCI). Traditionally, researchers have split approaches into an appearanceÂbased approach and a model
Numerical Modeling of the 2011 Tohoku Earthquake Tsunami
Frandsen, Jannette B.
Evolution of Ocean WAVEs) to reconstruct the tsunami across the Pacific and its transformation aroundNumerical Modeling of the 2011 Tohoku Earthquake Tsunami Yoshiki Yamazaki Post-doctoral Research 2011 Tohoku earthquake (Mw 9.0) generated a massive tsunami devastated the entire Pacific coast
Chimera: A hybrid approach to numerical loop quantum cosmology
Peter Diener; Brajesh Gupt; Parampreet Singh
2013-11-12T23:59:59.000Z
The existence of a quantum bounce in isotropic spacetimes is a key result in loop quantum cosmology (LQC), which has been demonstrated to arise in all the models studied so far. In most of the models, the bounce has been studied using numerical simulations involving states which are sharply peaked and which bounce at volumes much larger than the Planck volume. An important issue is to confirm the existence of the bounce for states which have a wide spread, or which bounce closer to the Planck volume. Numerical simulations with such states demand large computational domains, making them very expensive and practically infeasible with the techniques which have been implemented so far. To overcome these difficulties, we present an efficient hybrid numerical scheme using the property that at the small spacetime curvature, the quantum Hamiltonian constraint in LQC, which is a difference equation with uniform discretization in volume, can be approximated by a Wheeler-DeWitt differential equation. By carefully choosing a hybrid spatial grid allowing the use of partial differential equations at large volumes, and with a simple change of geometrical coordinate, we obtain a surprising reduction in the computational cost. This scheme enables us to explore regimes which were so far unachievable for the isotropic model in LQC. Our approach also promises to significantly reduce the computational cost for numerical simulations in anisotropic LQC using high performance computing.
A probabilistic numerical method for optimal multiple switching problem
performing the numerical resolution, the storage of the Monte Carlo simulation paths is not needed. Then, we at the minimum cost under a given constraint on the loss of load probability or on the level of energy non to thank Thomas Vareschi, Xavier Warin and the participants of the FiME seminar and the Energy Finance
Numerical Prediction of High-Impact Local Weather: A
Xue, Ming
Chapter 6 Numerical Prediction of High-Impact Local Weather: A Driver for Petascale Computing Ming winds, lightning, hurricanes and winter storms, cause hundreds of deaths and average annual economic of mitigating the impacts of such events on the economy and society is obvious, our ability to do so
Numerical simulation of turbulent jet primary breakup in Diesel engines
Helluy, Philippe
Numerical simulation of turbulent jet primary breakup in Diesel engines Peng Zeng1 Marcus Herrmann" IRMA Strasbourg, 23.Jan.2008 #12;Introduction DNS of Primary Breakup in Diesel Injection Phase Transition Modeling Turbulence Modeling Summary Outline 1 Introduction 2 DNS of Primary Breakup in Diesel
Numerical and experimental investigation of nonlinear properties of rubber absorber
Paris-Sud XI, Université de
Numerical and experimental investigation of nonlinear properties of rubber absorber in rail, Shanghai, 201804 Abstract: A dynamic nonlinear model of rubber absorber in railway fastening is proposed in this paper based on a superposition principal demonstrating that the restoring force of rubber components
Department of Numerical Analysis Modeling the Austenite Ferrite
Vuik, Kees
Department of Numerical Analysis Modeling the Austenite Ferrite Transformation by Cellular Ferrite Transformation by Cellular Automaton Improving Interface Stability Master of Science Thesis. Computational Materials Science 48.3 (2010): 692-699] for the austenite to ferrite transformation in low
EXPERIMENTAL AND NUMERICAL STUDY OF TRANSIENT ELECTRONIC CHIP COOLING BY
component to ensure reliable and stable performance and prevent any failure or malfunction [2, 3]. The heatEXPERIMENTAL AND NUMERICAL STUDY OF TRANSIENT ELECTRONIC CHIP COOLING BY LIQUID FLOW State University, Columbus, Ohio, USA Cooling of electronic chips has become a critical aspect
Inertia ratchets: A numerical study versus theory B. Lindner,1
Lindner, Benjamin
Inertia ratchets: A numerical study versus theory B. Lindner,1 L. Schimansky-Geier,1 P. Reimann,2 P in a periodic but asymmetric potential ratchet is investigated. Our special focus is on the influence of inertia cur- rent in periodic structures that lack reflection symmetry ratchets , e.g. see the reviews 1
On the numerical solution of some problems of environmental pollution
Ehrhardt, Matthias
On the numerical solution of some problems of environmental pollution Quang A Dang1 , Matthias world and their importance will even increase in the future. High pollution of air, water and soil may to the mathematical formula- tion of air pollution models. Let G be a cylindrical domain in the three
Numerical Simulation of the Wave Bottom Boundary Layer
Slinn, Donald
boundary layer. Oscillatory boundary layers are examined using a high-resolution time-dependent threeNumerical Simulation of the Wave Bottom Boundary Layer Over a Smooth Surface. Part 1: Three for turbulent boundary layers that occur over a smooth bottom. Results indicate that turbulence levels
ROOF CHARACTERISATION RELATED TO FIRE PROPAGATION RISK BY A NUMERICAL
Paris-Sud XI, Université de
ROOF CHARACTERISATION RELATED TO FIRE PROPAGATION RISK BY A NUMERICAL APPROACH L. Fournier1 , A by thé roof: - one is thé use of intumescent strips on thé roof, - thé other consists of extending thé fire walls (typically 70 cm or 1 m) above thé roof levé1 in order to prevent thé flame from being blown
Numerical Modeling of Brain Dynamics in Traumatic Situations -Impulsive Translations
Burtscher, Martin
.S.A. Abstract We numerically model the brain dy- namics during and after impulsive head translations using brain injuries appear among boxers and shaken babies despite minimal rotations of their heads. Modeling head translations also helps understand the brain dynamics during head rotations about an arbitrary
Numerical Methods for the Valuation of Synthetic Collateralized Debt Obligations
Toronto, University of
Numerical Methods for the Valuation of Synthetic Collateralized Debt Obligations by Xiaofang Ma Methods for the Valuation of Synthetic Collateralized Debt Obligations Xiaofang Ma Doctor of Philosophy methods for synthetic CDO valuation are presented. iii #12;Acknowledgements Although many people have
Particle acceleration in solar flares: observations versus numerical simulations
Particle acceleration in solar flares: observations versus numerical simulations A O Benz, P C processes such as isotropization and magnetic trapping are made. Keywords: Particle acceleration, hard X. As the electric field of reconnection with possible parallel component capable of particle acceleration is limited
CGMurphi: Automatic Synthesis of Numerical Controllers for Nonlinear Hybrid Systems
Tronci, Enrico
CGMurphi: Automatic Synthesis of Numerical Controllers for Nonlinear Hybrid Systems Giuseppe Della, thus much work is being done to create automatic controller synthesis tools. When dealing with critical systems, most of the times such controllers are required to be optimal and robust, i.e., they must achieve
NUMERICAL APPROXIMATION OF P-SYSTEMS WITH COULOMB FRICTIONAL DAMPING
to the precise nature of the dissipation. Dry (Coulomb) friction is a limit case that has not been fully analyzed in the presence of dry Coulomb friction. A model is described in detail in Section 2. A discretizationNUMERICAL APPROXIMATION OF P-SYSTEMS WITH COULOMB FRICTIONAL DAMPING KRISTY COFFEY AND PIERRE A
Direct Numerical Simulations and Modeling of Jets in Crossflow
Mahesh, Krishnan
Direct Numerical Simulations and Modeling of Jets in Crossflow A THESIS SUBMITTED TO THE FACULTY. i #12;To my parents and my grandparents, and to Ramnath ii #12;Abstract Jets in crossflow are used to study the different aspects of round jets in a crossflow. The first problem studies
Control of Jets in Crossflow using Direct Numerical Simulations
Mahesh, Krishnan
Control of Jets in Crossflow using Direct Numerical Simulations A THESIS SUBMITTED TO THE FACULTY in crossflow by axial pulsing. Our main idea is that pulsing generates vortex rings; the effect of pulsing on jets in crossflow can therefore be explained by studying the behavior of vortex rings in crossflow
RisR1448(EN) Numerical Study of the
is the better understanding of the physics of the aeroelastic motion of wind turbine blades in order to improve of wind turbine blades in order to improve the numerical simulation of such dynamical systems. In previous works, both aerodynamic damping cal- culations and fully-coupled aeroelastic simulations of wind turbine
Numerical modelling and analysis of a room temperature magnetic
Numerical modelling and analysis of a room temperature magnetic refrigeration system Thomas Frank and analysis of a room temperature magnetic refrigeration system Department: Fuel Cells and Solid State-dimensional mathematical model of an Active Magnetic Regenerator (AMR) system which is used for magnetic refrigeration
Numerical Simulation of Titanium Production in the Plasma Quench Reactor
Numerical Simulation of Titanium Production in the Plasma Quench Reactor Ray A. Beny and Randall A the nucleation of condensates in the steady-state supersonic nozzle flow generated in a plasma quench reactor reactions. The device has been termed the Plasma Quench Reactor or PQR. The PQR has demonstrated the ability
On the Numerical Simulation of Waterflooding of Heterogeneous
Furtado, Fred
On the Numerical Simulation of Waterflooding of Heterogeneous Petroleum Reservoirs Jim Douglas, Jr Simulation of Waterflooding of Heterogeneous Petroleum Reservoirs Â· A two-stage operator-splitting allows consider as a model problem the two-phase immiscible displacement in petroleum reservoirs. A very detailed
Cavitation level-acoustic intensity hysteresis: experimental and numerical characterization
Boyer, Edmond
Cavitation level-acoustic intensity hysteresis: experimental and numerical characterization P such as sonoporation, inertial cavitation is commonly considered as the main candidate inducing membrane poration. Thus, characterizing inertial cavitation, as related to bubble size distribution and medium history, is of great
Probabilistic methods applied to 2D electromagnetic numerical dosimetry
Paris-Sud XI, Université de
the determinist solution is widely recast [Ghanem and Kruger, 1996] and the so called non intrusive method on the non intrusive method because of the limitation of the numerical resources. Indeed, the intrusive using the polyno- mial chaos. There are two approaches: the so called intrusive method where
On Numerical Methods for Hyperbolic Conservation Laws and Related Equations
Bürger, Raimund
A classical kinematical model of sedimentation of small equal-sized particles dispersed in a viscous fluidOn Numerical Methods for Hyperbolic Conservation Laws and Related Equations Modelling Sedimentation with nonlocal flux, systems of nonlinear conservation modelling the sedimentation of polydisperse suspensions
Simulation of the secondary settling process with reliable numerical methods
Bürger, Raimund
are placed in alphabetical order Abstract A consistent model for the settling-compression-dispersion process The sedimentation process in the secondary settling tank (SST) is still a challenge in modelling the full Sedimentation, clarifier, conservation law, partial differential equation, numerical flux INTRODUCTION
155: Numerical Models of Groundwater Flow and Transport
Sorek, Shaul
155: Numerical Models of Groundwater Flow and Transport EKKEHARD HOLZBECHER1 AND SHAUL SOREK2 1. #12;2402 GROUNDWATER Calibration as a task cannot be separated from the other tasks. Inverse modeling of the Negev, J. Blaustein Institutes for Desert Research, Sede Boker, Israel The article gives an introduction
RisR1252(EN) The Numerical Wind Atlas
potential from high quality wind measurements. It estimates the local influences on the wind by small hillsRisÃ¸ÂRÂ1252(EN) The Numerical Wind Atlas -- the KAMM/WAsP Method Helmut P. Frank, Ole Rathmann The method of combining the Karlsruhe Atmospheric Mesoscale Model, KAMM, with the Wind Atlas Analysis
university-logo Numerical stability analysis for thin film flow
Marzuola, Jeremy
university-logo Numerical stability analysis for thin film flow: toward rigorous verification Blake Barker Indiana University October 2, 2013 B. Rigorous verification #12;university-logo Viscous roll waves (Picture courtesy Neil Balmforth, UBC.) B. Rigorous verification #12;university-logo Viscous roll waves 0 2
Numerical Modeling of Human Effect on Indoor Propagation
Paris-Sud XI, Université de
several types of obstacles such a brick enclosure walls, one metal heater, two metal wardrobes, two metal antenna placed 85 cm above the floor level. The spatial step is /10, or is the wavelength, chosen by the numerical dispersions. The choice of the spatial step is a compromise between the minimization of inaccuracy
Carmignani, B
2005-01-01T23:59:59.000Z
Numerical simulations of welds of thick steel pieces of interest for the thermonuclear fusion ITER machine
Numerical Analysis of Non-Uniformities and Anisotropy in High-Temperature Superconducting Coils
Hu, Di; Ainslie, Mark D.; Zou, Jin; Cardwell, David A.
2014-12-12T23:59:59.000Z
, critical current density (superconductivity), high-temperature superconductors, numerical analysis, superconducting coils, transport ac loss....
Basalt, Colorado: Energy Resources | Open Energy Information
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Hamann, Bernd
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS Int. J. Numer. Anal geomechanics Boris Jeremi!cc1, *,y , Gerik Scheuermann2,3 , Jan Frey3 , Zhaohui Yang1 , Bernd Hamann2 , Kenneth is the visualization of stress tensors resulting from 3D numerical simulations in computational geomechanics
Numerical investigation of recirculation in the UTSI MHD combustor
Schulz, R.J.; Lee, J.J.; Giel, T.V. Jr.
1983-09-01T23:59:59.000Z
Numerical studies were carried out to investigate the gross structure of flow in cylindrical combustors. The combustor configurations studied are variations of a working design used at the University of Tennessee Space Institute to burn pulverized coal at temperatures in excess of 3000K for generation of a plasma feeding a magnetohydrodynamic channel. The numerical studies were conducted for an isothermal fluid; the main objective of the calculations was to study the effect of the oxidant injection pattern on the gross structure of recirculating flows within the combustor. The calculations illustrate the basic features of the flow in combustors of this type and suggest implications for the injection of coal and oxidizer in this type of combustor.
Numerical Estimation of Frictional Torques with Rate and State Friction
Arun K. Singh; T. N. Singh
2015-01-20T23:59:59.000Z
In this paper, numerical estimation of frictional torques is carried out of a rotary elastic disc on a hard and rough surface under different rotating conditions. A one dimensional spring- mass rotary system is numerically solved under the quasistatic condition with the rate and state dependent friction model. It is established that torque of frictional strength as well as torque of steady dynamic stress increases with radius and found to be maximum at the periphery of the disc. Torque corresponding to frictional strength estimated using the analytical solution matches closely with the simulation only in the case of high stiffness of the connecting spring. In steady relaxation simulation, a steadily rotating disc is suddenly stopped and relaxational angular velocity and corresponding frictional torque decreases with both steady angular velocity and stiffness of the connecting spring in the velocity strengthening regime. In velocity weakening regime, in contrast, torque of relaxation stress deceases but relaxation velocity increases. The reason for the contradiction is explained.
Regularization of spherical and axisymmetric evolution codes in numerical relativity
Milton Ruiz; Miguel Alcubierre; Dario Nunez
2007-09-11T23:59:59.000Z
Several interesting astrophysical phenomena are symmetric with respect to the rotation axis, like the head-on collision of compact bodies, the collapse and/or accretion of fields with a large variety of geometries, or some forms of gravitational waves. Most current numerical relativity codes, however, can not take advantage of these symmetries due to the fact that singularities in the adapted coordinates, either at the origin or at the axis of symmetry, rapidly cause the simulation to crash. Because of this regularity problem it has become common practice to use full-blown Cartesian three-dimensional codes to simulate axi-symmetric systems. In this work we follow a recent idea idea of Rinne and Stewart and present a simple procedure to regularize the equations both in spherical and axi-symmetric spaces. We explicitly show the regularity of the evolution equations, describe the corresponding numerical code, and present several examples clearly showing the regularity of our evolutions.
Numerical Relativity as a tool for studying the Early Universe
David Garrison
2014-03-12T23:59:59.000Z
Numerical simulations are becoming a more effective tool for conducting detailed investigations into the evolution of our universe. In this article, we show how the framework of numerical relativity can be used for studying cosmological models. The author is working to develop a large-scale simulation of the dynamical processes in the early universe. These take into account interactions of dark matter, scalar perturbations, gravitational waves, magnetic fields and a turbulent plasma. The code described in this report is a GRMHD code based on the Cactus framework and is structured to utilize one of several different differencing methods chosen at run-time. It is being developed and tested on the University of Houston's Maxwell cluster.
Numerical Modeling of Charged Black Holes with Massive Dilaton
T. L. Boyadjiev; P. P. Fiziev
2003-11-28T23:59:59.000Z
In this paper the static, spherically symmetric and electrically charged black hole solutions in Einstein-Born-Infeld gravity with massive dilaton are investigated numerically. The Continuous Analog of Newton Method (CANM) is used to solve the corresponding nonlinear multipoint boundary value problems (BVPs). The linearized BVPs are solved numerically by means of collocation scheme of fourth order. A special class of solutions are the extremal ones. We show that the extremal horizons within the framework of the model satisfy some nonlinear system of algebraic equations. Depending on the charge $q$ and dilaton mass $\\gamma$, the black holes can have no more than three horizons. This allows us to construct some Hermite polynomial of third order. Its real roots describe the number, the type and other characteristics of the horizons.
Fractional Calculus in Hydrologic Modeling: A Numerical Perspective
David A. Benson; Mark M. Meerschaert; Jordan Revielle
2012-01-01T23:59:59.000Z
Fractional derivatives can be viewed either as a handy extension of classical calculus or, more deeply, as mathematical operators defined by natural phenomena. This follows the view that the diffusion equation is defined as the governing equation of a Brownian motion. In this paper, we emphasize that fractional derivatives come from the governing equations of stable Levy motion, and that fractional integration is the corresponding inverse operator. Fractional integration, and its multi-dimensional extensions derived in this way, are intimately tied to fractional Brownian (and Levy) motions and noises. By following these general principles, we discuss the Eulerian and Lagrangian numerical solutions to fractional partial differential equations, and Eulerian methods for stochastic integrals. These numerical approximations illuminate the essential nature of the fractional calculus.
Accurate complex scaling of three dimensional numerical potentials
Cerioni, Alessandro [European Synchrotron Radiation Facility, 6 rue Horowitz, BP220 38043 Grenoble Cedex 9 (France); Genovese, Luigi; Duchemin, Ivan; Deutsch, Thierry [Laboratoire de simulation atomistique (L-Sim), SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054 (France)
2013-05-28T23:59:59.000Z
The complex scaling method, which consists in continuing spatial coordinates into the complex plane, is a well-established method that allows to compute resonant eigenfunctions of the time-independent Schroedinger operator. Whenever it is desirable to apply the complex scaling to investigate resonances in physical systems defined on numerical discrete grids, the most direct approach relies on the application of a similarity transformation to the original, unscaled Hamiltonian. We show that such an approach can be conveniently implemented in the Daubechies wavelet basis set, featuring a very promising level of generality, high accuracy, and no need for artificial convergence parameters. Complex scaling of three dimensional numerical potentials can be efficiently and accurately performed. By carrying out an illustrative resonant state computation in the case of a one-dimensional model potential, we then show that our wavelet-based approach may disclose new exciting opportunities in the field of computational non-Hermitian quantum mechanics.
Hyperboloidal Slices and Artificial Cosmology for Numerical Relativity
Charles W. Misner
2006-03-11T23:59:59.000Z
This preliminary report proposes integrating the Maxwell equations in Minkowski spacetime using coordinates where the spacelike surfaces are hyperboloids asymptotic to null cones at spatial infinity. The space coordinates are chosen so that Scri+ occurs at a finite coordinate and a smooth extension beyond Scri+ is obtained. The question addressed is whether a Cauchy evolution numerical integration program can be easily modified to compute this evolution. In the spirit of the von Neumann and Richtmyer artificial viscosity which thickens a shock by many orders of magnitude to facilitate numerical simulation, I propose artificial cosmology to thicken null infinity Scri+ to approximate it by a de Sitter cosmological horizon where, in conformally compactified presentation, it provides a shell of purely outgoing null cones where asymptotic waves can be read off as data on a spacelike pure outflow outer boundary. This should be simpler than finding Scri+ as an isolated null boundary or imposing outgoing wave conditions at a timelike boundary at finite radius.
Non-Gaussian numerical errors versus mass hierarchy
Y. Meurice; M. B. Oktay
2000-05-12T23:59:59.000Z
We probe the numerical errors made in renormalization group calculations by varying slightly the rescaling factor of the fields and rescaling back in order to get the same (if there were no round-off errors) zero momentum 2-point function (magnetic susceptibility). The actual calculations were performed with Dyson's hierarchical model and a simplified version of it. We compare the distributions of numerical values obtained from a large sample of rescaling factors with the (Gaussian by design) distribution of a random number generator and find significant departures from the Gaussian behavior. In addition, the average value differ (robustly) from the exact answer by a quantity which is of the same order as the standard deviation. We provide a simple model in which the errors made at shorter distance have a larger weight than those made at larger distance. This model explains in part the non-Gaussian features and why the central-limit theorem does not apply.
On numerical considerations for modeling reactive astrophysical shocks
Papatheodore, Thomas L.; Messer, O. E. Bronson, E-mail: tpapathe@utk.edu, E-mail: bronson@ornl.gov [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States)
2014-02-10T23:59:59.000Z
Simulating detonations in astrophysical environments is often complicated by numerical approximations to shock structure. A common prescription to ensure correct detonation speeds and associated quantities is to prohibit burning inside the numerically broadened shock. We have performed a series of simulations to verify the efficacy of this approximation and to understand how resolution and dimensionality might affect its use. Our results show that in one dimension, prohibiting burning in the shock is important wherever the carbon burning length is not resolved, in keeping with the results of Fryxell et al. In two dimensions, we find that the prohibition of shock burning effectively inhibits the development of cellular structure for all but the most highly resolved cases. We discuss the possible impacts this outcome may have on sub-grid models and detonation propagation in models of Type Ia supernovae, including potential impacts on observables.
Refined numerical models for multidimensional Type Ia supernova simulations
Reinecke, M; Niemeyer, J C
2002-01-01T23:59:59.000Z
Following up on earlier work on this topic (Reinecke et al. 1999, A&A 347, pp. 724 and 739), we present an improved set of numerical models for simulations of white dwarfs exploding as Type Ia supernovae (SNe Ia). Two-dimensional simulations were used to test the reliability and numerical robustness of these algorithms; the results indicate that integral quantities like the total energy release are insensitive to changes of the grid resolution (above a certain threshold), which was not the case for our former code. The models were further enhanced to allow fully three-dimensional simulations of SNe Ia. A direct comparison of a 2D and a 3D calculation with identical initial conditions shows that the explosion is considerably more energetic in three dimensions; this is most likely caused by the assumption of axisymmetry in 2D, which inhibits the growth of flame instabilities in the azimuthal direction and thereby decreases the flame surface.
Refined numerical models for multidimensional Type Ia supernova simulations
M. Reinecke; W. Hillebrandt; J. C. Niemeyer
2001-11-26T23:59:59.000Z
Following up on earlier work on this topic (Reinecke et al. 1999, A&A 347, pp. 724 and 739), we present an improved set of numerical models for simulations of white dwarfs exploding as Type Ia supernovae (SNe Ia). Two-dimensional simulations were used to test the reliability and numerical robustness of these algorithms; the results indicate that integral quantities like the total energy release are insensitive to changes of the grid resolution (above a certain threshold), which was not the case for our former code. The models were further enhanced to allow fully three-dimensional simulations of SNe Ia. A direct comparison of a 2D and a 3D calculation with identical initial conditions shows that the explosion is considerably more energetic in three dimensions; this is most likely caused by the assumption of axisymmetry in 2D, which inhibits the growth of flame instabilities in the azimuthal direction and thereby decreases the flame surface.
Numerical solution of plasma fluid equations using locally refined grids
Colella, P., LLNL
1997-01-26T23:59:59.000Z
This paper describes a numerical method for the solution of plasma fluid equations on block-structured, locally refined grids. The plasma under consideration is typical of those used for the processing of semiconductors. The governing equations consist of a drift-diffusion model of the electrons and an isothermal model of the ions coupled by Poisson's equation. A discretization of the equations is given for a uniform spatial grid, and a time-split integration scheme is developed. The algorithm is then extended to accommodate locally refined grids. This extension involves the advancement of the discrete system on a hierarchy of levels, each of which represents a degree of refinement, together with synchronization steps to ensure consistency across levels. A brief discussion of a software implementation is followed by a presentation of numerical results.
Numerical analysis of nanostructures for enhanced light extraction from OLEDs
Zschiedrich, L; Burger, S; Schmidt, F; 10.1117/12.2001132
2013-01-01T23:59:59.000Z
Nanostructures, like periodic arrays of scatters or low-index gratings, are used to improve the light outcoupling from organic light-emitting diodes (OLED). In order to optimize geometrical and material properties of such structures, simulations of the outcoupling process are very helpful. The finite element method is best suited for an accurate discretization of the geometry and the singular-like field profile within the structured layer and the emitting layer. However, a finite element simulation of the overall OLED stack is often beyond available computer resources. The main focus of this paper is the simulation of a single dipole source embedded into a twofold infinitely periodic OLED structure. To overcome the numerical burden we apply the Floquet transform, so that the computational domain reduces to the unit cell. The relevant outcoupling data are then gained by inverse Flouqet transforming. This step requires a careful numerical treatment as reported in this paper.
On Numerical Considerations for Modeling Reactive Astrophysical Shocks
Papatheodore, Thomas L [ORNL] [ORNL; Messer, Bronson [ORNL] [ORNL
2014-01-01T23:59:59.000Z
Simulating detonations in astrophysical environments is often complicated by numerical approximations to shock structure. A common prescription to ensure correct detonation speeds (and associated quantities) is to prohibit burning inside the numerically broadened shock (Fryxell et al. 1989). We have performed a series of simulations to verify the efficacy of this approximation and to understand how resolution and dimensionality might affect its use. Our results show that, in one dimension, prohibiting burning in the shock is important wherever the carbon burning length is not resolved, in keeping with the results of Fryxell et al. (1989). In two dimensions, we find that the prohibition of shock burning effectively inhibits the development of cellular structure for all but the most highly-resolved cases. We discuss the possible impacts this outcome may have on sub-grid models and detonation propagation in Type Ia supernovae.
Numerical method for shear bands in ductile metal with inclusions
Plohr, Jee Yeon N [Los Alamos National Laboratory; Plohr, Bradley J [Los Alamos National Laboratory
2010-01-01T23:59:59.000Z
A numerical method for mesoscale simulation of high strain-rate loading of ductile metal containing inclusions is described. Because of small-scale inhomogeneities, such a composite material is prone to localized shear deformation (adiabatic shear bands). The modeling framework is the Generalized Method of Cells of Paley and Aboudi [Mech. Materials, vol. 14, pp. /27-139, 1992], which ensures that the micromechanical response of the material is reflected in the behavior of the composite at the mesoscale. To calculate the effective plastic strain rate when shear bands are present, the analytic and numerical analysis of shear bands by Glimm, Plohr, and Sharp [Mech. Materials, vol. 24, pp. 31-41, 1996] is adapted and extended.
Noncommutative Field Theory: Numerical Analysis with the Fuzzy Disc
Fedele Lizzi; Bernardino Spisso
2012-07-28T23:59:59.000Z
The fuzzy disc is a discretization of the algebra of functions on the two dimensional disc using finite matrices which preserves the action of the rotation group. We define a $\\varphi^4$ scalar field theory on it and analyze numerically for three different limits for the rank of the matrix going to infinity. The numerical simulations reveal three different phases: uniform and disordered phases already the present in the commutative scalar field theory and a nonuniform ordered phase as a noncommutative effects. We have computed the transition curves between phases and their scaling. This is in agreement with studies on the fuzzy sphere, although the speed of convergence for the disc seems to be better. We have performed also three the limits for the theory in the cases of the theory going to the commutative plane or commutative disc. In this case the theory behaves differently, showing the intimate relationship between the nonuniform phase and noncommutative geometry.
A Generic Framework for Interprocedural Analysis of Numerical Properties
Seidl, Helmut
A Generic Framework for Interprocedural Analysis of Numerical Properties Markus MË?ullerÂOlm 1, Germany markus.muellerÂolm@cs.uniÂdortmund.de 2 TU MË?unchen, Institut fË?ur Informatik, I2 80333 M of the abstracted collecting semantics is also used by MË?ullerÂOlm and Seidl in [12] where (in absence of equality
Numerical analysis of a microwave torch with axial gas injection
Gritsinin, S. I.; Davydov, A. M.; Kossyi, I. A., E-mail: kossyi@fpl.gpi.ru [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Kulumbaev, E. B. [National Research University Belgorod State University (Russian Federation)] [National Research University Belgorod State University (Russian Federation); Lelevkin, V. M. [Kyrgyz-Russian Slavic University (Kyrgyzstan)] [Kyrgyz-Russian Slavic University (Kyrgyzstan)
2013-07-15T23:59:59.000Z
The characteristics of a microwave discharge in an argon jet injected axially into a coaxial channel with a shortened inner electrode are numerically analyzed using a self-consistent equilibrium gas-dynamic model. The specific features of the excitation and maintenance of the microwave discharge are determined, and the dependences of the discharge characteristics on the supplied electromagnetic power and gas flow rate are obtained. The calculated results are compared with experimental data.
Comparative study of variational chaos indicators and ODEs' numerical integrators
Luciano A. Darriba; Nicolás P. Maffione; Pablo M. Cincotta; Claudia M. Giordano
2012-05-08T23:59:59.000Z
The reader can find in the literature a lot of different techniques to study the dynamics of a given system and also, many suitable numerical integrators to compute them. Notwithstanding the recent work of Maffione et al. (2011a) for mappings, a detailed comparison among the widespread indicators of chaos in a general system is still lacking. Such a comparison could lead to select the most efficient algorithms given a certain dynamical problem. Furthermore, in order to choose the appropriate numerical integrators to compute them, more comparative studies among numerical integrators are also needed. This work deals with both problems. We first extend the work of Maffione et al. (2011) for mappings to the 2D H\\'enon & Heiles (1964) potential, and compare several variational indicators of chaos: the Lyapunov Indicator (LI); the Mean Exponential Growth Factor of Nearby Orbits (MEGNO); the Smaller Alignment Index (SALI) and its generalized version, the Generalized Alignment Index (GALI); the Fast Lyapunov Indicator (FLI) and its variant, the Orthogonal Fast Lyapunov Indicator (OFLI); the Spectral Distance (D) and the Dynamical Spectras of Stretching Numbers (SSNs). We also include in the record the Relative Lyapunov Indicator (RLI), which is not a variational indicator as the others. Then, we test a numerical technique to integrate Ordinary Differential Equations (ODEs) based on the Taylor method implemented by Jorba & Zou (2005) (called taylor), and we compare its performance with other two well-known efficient integrators: the Prince & Dormand (1981) implementation of a Runge-Kutta of order 7-8 (DOPRI8) and a Bulirsch-St\\"oer implementation. These tests are run under two very different systems from the complexity of their equations point of view: a triaxial galactic potential model and a perturbed 3D quartic oscillator.
Efficiency improvements for the numerical computation of NLO corrections
Sebastian Becker; Christian Reuschle; Stefan Weinzierl
2012-06-25T23:59:59.000Z
In this paper we discuss techniques, which lead to a significant improvement of the efficiency of the Monte Carlo integration, when one-loop QCD amplitudes are calculated numerically with the help of the subtraction method and contour deformation. The techniques discussed are: holomorphic and non-holomorphic division into sub-channels, optimisation of the integration contour, improvement of the ultraviolet subtraction terms, importance sampling and antithetic variates in loop momentum space, recurrence relations.
Numerical Verification of Bounce Harmonic Resonances in Neoclassical
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Numerical Simulation of the Hydrodynamical Combustion to Strange Quark Matter
Brian Niebergal; Rachid Ouyed; Prashanth Jaikumar
2010-08-27T23:59:59.000Z
We present results from a numerical solution to the burning of neutron matter inside a cold neutron star into stable (u,d,s) quark matter. Our method solves hydrodynamical flow equations in 1D with neutrino emission from weak equilibrating reactions, and strange quark diffusion across the burning front. We also include entropy change due to heat released in forming the stable quark phase. Our numerical results suggest burning front laminar speeds of 0.002-0.04 times the speed of light, much faster than previous estimates derived using only a reactive-diffusive description. Analytic solutions to hydrodynamical jump conditions with a temperature dependent equation of state agree very well with our numerical findings for fluid velocities. The most important effect of neutrino cooling is that the conversion front stalls at lower density (below approximately 2 times saturation density). In a 2-dimensional setting, such rapid speeds and neutrino cooling may allow for a flame wrinkle instability to develop, possibly leading to detonation.
Notes on the integration of numerical relativity waveforms
Christian Reisswig; Denis Pollney
2011-09-22T23:59:59.000Z
A primary goal of numerical relativity is to provide estimates of the wave strain, $h$, from strong gravitational wave sources, to be used in detector templates. The simulations, however, typically measure waves in terms of the Weyl curvature component, $\\psi_4$. Assuming Bondi gauge, transforming to the strain $h$ reduces to integration of $\\psi_4$ twice in time. Integrations performed in either the time or frequency domain, however, lead to secular non-linear drifts in the resulting strain $h$. These non-linear drifts are not explained by the two unknown integration constants which can at most result in linear drifts. We identify a number of fundamental difficulties which can arise from integrating finite length, discretely sampled and noisy data streams. These issues are an artifact of post-processing data. They are independent of the characteristics of the original simulation, such as gauge or numerical method used. We suggest, however, a simple procedure for integrating numerical waveforms in the frequency domain, which is effective at strongly reducing spurious secular non-linear drifts in the resulting strain.
Transient productivity index for numerical well test simulations
Blanc, G.; Ding, D.Y.; Ene, A. [Institut Francais du Petrole, Pau (France)] [and others
1997-08-01T23:59:59.000Z
The most difficult aspect of numerical simulation of well tests is the treatment of the Bottom Hole Flowing (BHF) Pressure. In full field simulations, this pressure is derived from the Well-block Pressure (WBP) using a numerical productivity index which accounts for the grid size and permeability, and for the well completion. This productivity index is calculated assuming a pseudo-steady state flow regime in the vicinity of the well and is therefore constant during the well production period. Such a pseudo-steady state assumption is no longer valid for the early time of a well test simulation as long as the pressure perturbation has not reached several grid-blocks around the well. This paper offers two different solutions to this problem: (1) The first one is based on the derivation of a Numerical Transient Productivity Index (NTPI) to be applied to Cartesian grids; (2) The second one is based on the use of a Corrected Transmissibility and Accumulation Term (CTAT) in the flow equation. The representation of the pressure behavior given by both solutions is far more accurate than the conventional one as shown by several validation examples which are presented in the following pages.
Numerical Methods of Computational Electromagnetics for Complex Inhomogeneous Systems
Cai, Wei
2014-05-15T23:59:59.000Z
Understanding electromagnetic phenomena is the key in many scientific investigation and engineering designs such as solar cell designs, studying biological ion channels for diseases, and creating clean fusion energies, among other things. The objectives of the project are to develop high order numerical methods to simulate evanescent electromagnetic waves occurring in plasmon solar cells and biological ion-channels, where local field enhancement within random media in the former and long range electrostatic interactions in the latter are of major challenges for accurate and efficient numerical computations. We have accomplished these objectives by developing high order numerical methods for solving Maxwell equations such as high order finite element basis for discontinuous Galerkin methods, well-conditioned Nedelec edge element method, divergence free finite element basis for MHD, and fast integral equation methods for layered media. These methods can be used to model the complex local field enhancement in plasmon solar cells. On the other hand, to treat long range electrostatic interaction in ion channels, we have developed image charge based method for a hybrid model in combining atomistic electrostatics and continuum Poisson-Boltzmann electrostatics. Such a hybrid model will speed up the molecular dynamics simulation of transport in biological ion-channels.
Stochastic algorithms for the analysis of numerical flame simulations
Bell, John B.; Day, Marcus S.; Grcar, Joseph F.; Lijewski, Michael J.
2004-04-26T23:59:59.000Z
Recent progress in simulation methodologies and high-performance parallel computers have made it is possible to perform detailed simulations of multidimensional reacting flow phenomena using comprehensive kinetics mechanisms. As simulations become larger and more complex, it becomes increasingly difficult to extract useful information from the numerical solution, particularly regarding the interactions of the chemical reaction and diffusion processes. In this paper we present a new diagnostic tool for analysis of numerical simulations of reacting flow. Our approach is based on recasting an Eulerian flow solution in a Lagrangian frame. Unlike a conventional Lagrangian view point that follows the evolution of a volume of the fluid, we instead follow specific chemical elements, e.g., carbon, nitrogen, etc., as they move through the system . From this perspective an ''atom'' is part of some molecule of a species that is transported through the domain by advection and diffusion. Reactions cause the atom to shift from one chemical host species to another and the subsequent transport of the atom is given by the movement of the new species. We represent these processes using a stochastic particle formulation that treats advection deterministically and models diffusion and chemistry as stochastic processes. In this paper, we discuss the numerical issues in detail and demonstrate that an ensemble of stochastic trajectories can accurately capture key features of the continuum solution. The capabilities of this diagnostic are then demonstrated by applications to study the modulation of carbon chemistry during a vortex-flame interaction, and the role of cyano chemistry in rm NO{sub x} production for a steady diffusion flame.
Numerical studies of the stochastic Korteweg-de Vries equation
Lin Guang [Division of Applied Mathematics, Brown University, 182 George Street, Box F, Providence, RI 02912 (United States); Grinberg, Leopold [Division of Applied Mathematics, Brown University, 182 George Street, Box F, Providence, RI 02912 (United States); Karniadakis, George Em [Division of Applied Mathematics, Brown University, 182 George Street, Box F, Providence, RI 02912 (United States)]. E-mail: gk@dam.brown.edu
2006-04-10T23:59:59.000Z
We present numerical solutions of the stochastic Korteweg-de Vries equation for three cases corresponding to additive time-dependent noise, multiplicative space-dependent noise and a combination of the two. We employ polynomial chaos for discretization in random space, and discontinuous Galerkin and finite difference for discretization in physical space. The accuracy of the stochastic solutions is investigated by comparing the first two moments against analytical and Monte Carlo simulation results. Of particular interest is the interplay of spatial discretization error with the stochastic approximation error, which is examined for different orders of spatial and stochastic approximation.
Direct numerical integration for multi-loop integrals
Sebastian Becker; Stefan Weinzierl
2013-03-18T23:59:59.000Z
We present a method to construct a suitable contour deformation in loop momentum space for multi-loop integrals. This contour deformation can be used to perform the integration for multi-loop integrals numerically. The integration can be performed directly in loop momentum space without the introduction of Feynman or Schwinger parameters. The method can be applied to finite multi-loop integrals and to divergent multi-loop integrals with suitable subtraction terms. The algorithm extends techniques from the one-loop case to the multi-loop case. Examples at two and three loops are discussed explicitly.
Connecting Numerical Relativity and Data Analysis of Gravitational Wave Detectors
Shoemaker, Deirdre; London, Lionel; Pekowsky, Larne
2015-01-01T23:59:59.000Z
Gravitational waves deliver information in exquisite detail about astrophysical phenomena, among them the collision of two black holes, a system completely invisible to the eyes of electromagnetic telescopes. Models that predict gravitational wave signals from likely sources are crucial for the success of this endeavor. Modeling binary black hole sources of gravitational radiation requires solving the Eintein equations of General Relativity using powerful computer hardware and sophisticated numerical algorithms. This proceeding presents where we are in understanding ground-based gravitational waves resulting from the merger of black holes and the implications of these sources for the advent of gravitational-wave astronomy.
Diffusive mesh relaxation in ALE finite element numerical simulations
Dube, E.I.
1996-06-01T23:59:59.000Z
The theory for a diffusive mesh relaxation algorithm is developed for use in three-dimensional Arbitary Lagrange/Eulerian (ALE) finite element simulation techniques. This mesh relaxer is derived by a variational principle for an unstructured 3D grid using finite elements, and incorporates hourglass controls in the numerical implementation. The diffusive coefficients are based on the geometric properties of the existing mesh, and are chosen so as to allow for a smooth grid that retains the general shape of the original mesh. The diffusive mesh relaxation algorithm is then applied to an ALE code system, and results from several test cases are discussed.
Numerical investigation of closed-loop control for Hall accelerators
Barral, S.; Miedzik, J. [Institute of Plasma Physics and Laser Microfusion, 01497 Warsaw (Poland)
2011-01-01T23:59:59.000Z
Low frequency discharge current oscillations in Hall accelerators are conventionally damped with external inductor-capacitor (LC) or resistor-inductor-capacitor (RLC) networks. The role of such network in the stabilization of the plasma discharge is investigated with a numerical model and the potential advantages of proportional-integral-derivative (PID) closed-loop control over RLC networks are subsequently assessed using either discharge voltage or magnetic field modulation. Simulations confirm the reduction of current oscillations in the presence of a RLC network, but suggest that PID control could ensure nearly oscillation-free operation with little sensitivity toward the PID settings.
ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS
Chiswell, S.; Buckley, R.
2009-01-15T23:59:59.000Z
During the year 2008, the United States National Weather Service (NWS) completed an eight fold increase in sampling capability for weather radars to 250 m resolution. This increase is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current NWS operational model domains utilize grid spacing an order of magnitude larger than the radar data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of radar reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution was investigated under a Laboratory Directed Research and Development (LDRD) 'quick hit' grant to determine the impact of improved data resolution on model predictions with specific initial proof of concept application to daily Savannah River Site operations and emergency response. Development of software to process NWS radar reflectivity and radial velocity data was undertaken for assimilation of observations into numerical models. Data values within the radar data volume undergo automated quality control (QC) analysis routines developed in support of this project to eliminate empty/missing data points, decrease anomalous propagation values, and determine error thresholds by utilizing the calculated variances among data values. The Weather Research and Forecasting model (WRF) three dimensional variational data assimilation package (WRF-3DVAR) was used to incorporate the QC'ed radar data into input and boundary conditions. The lack of observational data in the vicinity of SRS available to NWS operational models signifies an important data void where radar observations can provide significant input. These observations greatly enhance the knowledge of storm structures and the environmental conditions which influence their development. As the increase in computational power and availability has made higher resolution real-time model simulations possible, the need to obtain observations to both initialize numerical models and verify their output has become increasingly important. The assimilation of high resolution radar observations therefore provides a vital component in the development and utility of numerical model forecasts for both weather forecasting and contaminant transport, including future opportunities to improve wet deposition computations explicitly.
Numerical analysis of decoy state quantum key distribution protocols
Harrington, Jim W [Los Alamos National Laboratory; Rice, Patrick R [Los Alamos National Laboratory
2008-01-01T23:59:59.000Z
Decoy state protocols are a useful tool for many quantum key distribution systems implemented with weak coherent pulses, allowing significantly better secret bit rates and longer maximum distances. In this paper we present a method to numerically find optimal three-level protocols, and we examine how the secret bit rate and the optimized parameters are dependent on various system properties, such as session length, transmission loss, and visibility. Additionally, we show how to modify the decoy state analysis to handle partially distinguishable decoy states as well as uncertainty in the prepared intensities.
Numerical solution of the linear least squares problem for splines
Vonderhaar, Thomas Jerome
1975-01-01T23:59:59.000Z
) Ci?. . &: , i ~ '(8'??. (Member) (Member) May 1975 ABSTRACT Numerical Solution of the Linear Least Squares Problem for Splines. (May 1975) Thomas Jerome Vonderhaar B. A. , Lewis University Chairman of Advisory Committee: Dr. Philip W. Smith... in the preparation of this thesis. I would also like to thank Dr. C. K. Chui and Dr. R. D. Larsen for serving on my committee. My sincere gratitude goes to Myra McWatt for her understanding and moral support during the completion of this paper. TABLE OF CONTENTS...
Sandia Energy - Numerical Manufacturing And Design Tool (NuMAD)
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AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal PwerPerkins County, Nebraska:PrecourtOid JumpEligSysSize JumpTechDsc JumpAlpha3 Jump to:Numeric
Lim, Sung Jin
2012-01-01T23:59:59.000Z
This dissertation mainly studied on numerical approximation methods as a solution of the integrability problem and the measure of welfare changes, and demonstrated how numerical algorithms can be applied in empirical studies ...
Mathiesen, Patrick; Kleissl, Jan
2011-01-01T23:59:59.000Z
transport and numerical weather modeling. J. Applied cross correlations. Weather and Forecasting, 8:4, 401?of radiation for numerical weather prediction and climate
NUMERICAL ANALYSIS OF A FINITE ELEMENT SCHEME FOR THE APPROXIMATION OF HARMONIC MAPS INTO SURFACES
Bartels, Soeren
NUMERICAL ANALYSIS OF A FINITE ELEMENT SCHEME FOR THE APPROXIMATION OF HARMONIC MAPS INTO SURFACES Geometric partial differential equations and their analysis as well as numerical simulation have recently
Radiative feedback and cosmic molecular gas: numerical method
Margarita Petkova; Umberto Maio
2012-02-27T23:59:59.000Z
We present results from self-consistent 3D numerical simulations of cosmic structure formation with a multi-frequency radiative transfer scheme and non-equilibrium molecular chemistry of 13 primordial species (e-, H, H+, H-, He, He+, He++, H2, H2+, D, D+, HD, HeH+), performed by using the simulation code GADGET. We describe our implementation and show tests for ionized sphere expansion in a static and dynamic density field around a central radiative source, and for cosmological abundance evolution coupled with the cosmic microwave background radiation. As a demonstrative application of radiative feedback on molecular gas, we run also cosmological simulations of early structure formation in a ~1Mpc size box. Our tests agree well with analytical and numerical expectations. Consistently with other works, we find that ionization fronts from central sources can boost H2 fractions in shock-compressed gas. The tight dependence on H2 lead to a corresponding boost of HD fractions, as well. We see a strong lowering of the the typical molecular abundances up to several orders of magnitudes which partially hinders further gas collapse of pristine neutral gas, and clearly suggests the need of re-ionized gas or metal cooling for the formation of the following generation of structures.
Numerical and experimental investigation of vortical flow-flame interaction
Najm, H.N.; Schefer, R.W.; Milne, R.B.; Mueller, C.J. [Sandia National Labs., Livermore, CA (United States); Devine, K.D.; Kempka, S.N. [Sandia National Labs., Albuquerque, NM (United States)
1998-02-01T23:59:59.000Z
A massively parallel coupled Eulerian-Lagrangian low Mach number reacting flow code is developed and used to study the structure and dynamics of a forced planar buoyant jet flame in two dimensions. The numerical construction uses a finite difference scheme with adaptive mesh refinement for solving the scalar conservation equations, and the vortex method for the momentum equations, with the necessary coupling terms. The numerical model construction is presented, along with computational issues regarding the parallel implementation. An experimental acoustically forced planar jet burner apparatus is also developed and used to study the velocity and scalar fields in this flow, and to provide useful data for validation of the computed jet. Burner design and laser diagnostic details are discussed, along with the measured laboratory jet flame dynamics. The computed reacting jet flow is also presented, with focus on both large-scale outer buoyant structures and the lifted flame stabilization dynamics. A triple flame structure is observed at the flame base in the computed flow, as is theoretically expected, but was not observable with present diagnostic techniques in the laboratory flame. Computed and experimental results are compared, along with implications for model improvements.
Numerical Model for Conduction-Cooled Current Lead Heat Loads
White, M.J.; Wang, X.L.; /Fermilab; Brueck, H.D.; /DESY
2011-06-10T23:59:59.000Z
Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world; however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal intercepts. The model is validated by comparing the numerical model results to ideal cases where analytical equations are valid. In addition, the XFEL (X-Ray Free Electron Laser) prototype current leads are modeled and compared to the experimental results from testing at DESY's XFEL Magnet Test Stand (XMTS) and Cryomodule Test Bench (CMTB).
MAGNETIZATION DEGREE OF GAMMA-RAY BURST FIREBALLS: NUMERICAL STUDY
Harrison, Richard; Kobayashi, Shiho, E-mail: R.M.Harrison@2006.ljmu.ac.uk [Astrophysics Research Institute, Liverpool John Moores University, Liverpool, L3 5RF (United Kingdom)
2013-08-01T23:59:59.000Z
The relative strength between forward and reverse shock emission in early gamma-ray burst (GRB) afterglow reflects that of magnetic energy densities in the two shock regions. We numerically show that with the current standard treatment, the fireball magnetization is underestimated by up to two orders of magnitude. This discrepancy is especially large in the sub-relativistic reverse shock regime (i.e., the thin shell and intermediate regime), where most optical flashes were detected. We provide new analytic estimates of the reverse shock emission based on a better shock approximation, which well describe numerical results in the intermediate regime. We show that the reverse shock temperature at the onset of afterglow is constant, ( {Gamma}-bar{sub d}-1){approx}8 Multiplication-Sign 10{sup -2}, when the dimensionless parameter {xi}{sub 0} is more than several. Our approach is applied to case studies of GRB 990123 and 090102, and we find that magnetic fields in the fireballs are even stronger than previously believed. However, these events are still likely to be due to a baryonic jet with {sigma} {approx} 10{sup -3} for GRB 990123 and {approx}3 Multiplication-Sign 10{sup -4} to 3 for GRB 090102.
Theory comparison and numerical benchmarking on neoclassical toroidal viscosity torque
Wang, Zhirui; Park, Jong-Kyu; Logan, Nikolas; Kim, Kimin; Menard, Jonathan E. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States); Liu, Yueqiang [Euratom/CCFE Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)] [Euratom/CCFE Association, Culham Science Centre, Abingdon OX14 3DB (United Kingdom)
2014-04-15T23:59:59.000Z
Systematic comparison and numerical benchmarking have been successfully carried out among three different approaches of neoclassical toroidal viscosity (NTV) theory and the corresponding codes: IPEC-PENT is developed based on the combined NTV theory but without geometric simplifications [Park et al., Phys. Rev. Lett. 102, 065002 (2009)]; MARS-Q includes smoothly connected NTV formula [Shaing et al., Nucl. Fusion 50, 025022 (2010)] based on Shaing's analytic formulation in various collisionality regimes; MARS-K, originally computing the drift kinetic energy, is upgraded to compute the NTV torque based on the equivalence between drift kinetic energy and NTV torque [J.-K. Park, Phys. Plasma 18, 110702 (2011)]. The derivation and numerical results both indicate that the imaginary part of drift kinetic energy computed by MARS-K is equivalent to the NTV torque in IPEC-PENT. In the benchmark of precession resonance between MARS-Q and MARS-K/IPEC-PENT, the agreement and correlation between the connected NTV formula and the combined NTV theory in different collisionality regimes are shown for the first time. Additionally, both IPEC-PENT and MARS-K indicate the importance of the bounce harmonic resonance which can greatly enhance the NTV torque when E×B drift frequency reaches the bounce resonance condition.
Fast numerical treatment of nonlinear wave equations by spectral methods
Skjaeraasen, Olaf [ProsTek, Institute for Energy Technology, P.O. Box 40, N-2027 Kjeller (Norway); Robinson, P. A. [School of Physics, University of Sydney, New South Wales 2006 (Australia); Newman, D. L. [Center for Integrated Plasma Studies, University of Colorado at Boulder, Boulder, Colorado 80309 (United States)
2011-02-15T23:59:59.000Z
A method is presented that accelerates spectral methods for numerical solution of a broad class of nonlinear partial differential wave equations that are first order in time and that arise in plasma wave theory. The approach involves exact analytical treatment of the linear part of the wave evolution including growth and damping as well as dispersion. After introducing the method for general scalar and vector equations, we discuss and illustrate it in more detail in the context of the coupling of high- and low-frequency plasma wave modes, as modeled by the electrostatic and electromagnetic Zakharov equations in multiple dimensions. For computational efficiency, the method uses eigenvector decomposition, which is particularly advantageous when the wave damping is mode-dependent and anisotropic in wavenumber space. In this context, it is shown that the method can significantly speed up numerical integration relative to standard spectral or finite difference methods by allowing much longer time steps, especially in the limit in which the nonlinear Schroedinger equation applies.
Numerical treatment of interfaces for second-order wave equations
F. Parisi; M. Cécere; M. Iriondo; O. Reula
2014-06-12T23:59:59.000Z
In this article we develop a numerical scheme to deal with interfaces between touching numerical grids when solving the second-order wave equation. We show that it is possible to implement an interface scheme of "penalty" type for the second-order wave equation, similar to the ones used for first-order hyperbolic and parabolic equations, and the second-order scheme used by Mattsson et al (2008). These schemes, known as SAT schemes for finite difference approximations and penalties for spectral ones, and ours share similar properties but in our case one needs to pass at the interface a smaller amount of data than previously known schemes. This is important for multi-block parallelizations in several dimensions, for it implies that one obtains the same solution quality while sharing among different computational grids only a fraction of the data one would need for a comparable (in accuracy) SAT or Mattsson et al.'s scheme. The semi-discrete approximation used here preserves the norm and uses standard finite-difference operators satisfying summation by parts. For the time integrator we use a semi-implicit IMEX Runge-Kutta method. This is crucial, since the explicit Runge-Kutta method would be impractical given the severe restrictions that arise from the stiff parts of the equations.
Comparing Post-Newtonian and Numerical-Relativity Precession Dynamics
Ossokine, Serguei; Kidder, Lawrence E; Pfeiffer, Harald P; Scheel, Mark A; Szilágyi, Béla
2015-01-01T23:59:59.000Z
Binary black-hole systems are expected to be important sources of gravitational waves for upcoming gravitational-wave detectors. If the spins are not colinear with each other or with the orbital angular momentum, these systems exhibit complicated precession dynamics that are imprinted on the gravitational waveform. We develop a new procedure to match the precession dynamics computed by post-Newtonian (PN) theory to those of numerical binary black-hole simulations in full general relativity. For numerical relativity NR) simulations lasting approximately two precession cycles, we find that the PN and NR predictions for the directions of the orbital angular momentum and the spins agree to better than $\\sim 1^{\\circ}$ with NR during the inspiral, increasing to $5^{\\circ}$ near merger. Nutation of the orbital plane on the orbital time-scale agrees well between NR and PN, whereas nutation of the spin direction shows qualitatively different behavior in PN and NR. We also examine how the PN equations for precession a...
Comparing Post-Newtonian and Numerical-Relativity Precession Dynamics
Serguei Ossokine; Michael Boyle; Lawrence E. Kidder; Harald P. Pfeiffer; Mark A. Scheel; Béla Szilágyi
2015-02-05T23:59:59.000Z
Binary black-hole systems are expected to be important sources of gravitational waves for upcoming gravitational-wave detectors. If the spins are not colinear with each other or with the orbital angular momentum, these systems exhibit complicated precession dynamics that are imprinted on the gravitational waveform. We develop a new procedure to match the precession dynamics computed by post-Newtonian (PN) theory to those of numerical binary black-hole simulations in full general relativity. For numerical relativity NR) simulations lasting approximately two precession cycles, we find that the PN and NR predictions for the directions of the orbital angular momentum and the spins agree to better than $\\sim 1^{\\circ}$ with NR during the inspiral, increasing to $5^{\\circ}$ near merger. Nutation of the orbital plane on the orbital time-scale agrees well between NR and PN, whereas nutation of the spin direction shows qualitatively different behavior in PN and NR. We also examine how the PN equations for precession and orbital-phase evolution converge with PN order, and we quantify the impact of various choices for handling partially known PN terms.
Pearce, Fred
2003-01-01T23:59:59.000Z
We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir
THESIS FOR THE DEGREE OF LICENTIATE OF ENGINEERING Numerical Folding of Airbags
Patriksson, Michael
THESIS FOR THE DEGREE OF LICENTIATE OF ENGINEERING Numerical Folding of Airbags Based of Technology and GÂ¨oteborg University GÂ¨oteborg, Sweden 2007 #12;Numerical Folding of Airbags BasedÂ¨oteborg, Sweden 2007 #12;Numerical Folding of Airbags Based on Optimization and Origami Christoffer Cromvik
Numerical study of high heat ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b
Maruyama, Shigeo
Numerical study of high heat ¯ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b , Shigeo simulation model of boiling heat transfer is proposed based on a numerical macrolayer model [S. Maruyama, M. Shoji, S. Shimizu, A numerical simulation of transition boiling heat transfer, in: Proceedings
Numerical Methods for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory
Zhihao Ge; Ruihua Li
2014-12-25T23:59:59.000Z
In the work, the numerical methods are designed for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory. The numerical methods are novel and effective to determine the critical transition temperature and approximate to the energy gap function of the above model. Finally, a numerical example confirming the theoretical results is presented.
Numerical Methods for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory
Zhihao Ge; Ruihua Li
2015-03-08T23:59:59.000Z
In the work, the numerical methods are designed for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory. The numerical methods are novel and effective to determine the critical transition temperature and approximate to the energy gap function of the above model. Finally, a numerical example confirming the theoretical results is presented.
NUMERICAL SOLUTION OF HYBRID OPTIMAL CONTROL PROBLEMS WITH APPLICATIONS IN ROBOTICS
Stryk, Oskar von
NUMERICAL SOLUTION OF HYBRID OPTIMAL CONTROL PROBLEMS WITH APPLICATIONS IN ROBOTICS Martin Buss.g. (Buss et al., 2000; Buss, 2001; Tomlin, 1999). The key to numerically solving HOCPs appears to lie (Buss et al., 2000; Stryk and Glocker, 2000). This paper presents numerical solution techniques
Mathematical and Numerical Analyses of Peridynamics for Multiscale Materials Modeling
Du, Qiang
2014-11-12T23:59:59.000Z
The rational design of materials, the development of accurate and efficient material simulation algorithms, and the determination of the response of materials to environments and loads occurring in practice all require an understanding of mechanics at disparate spatial and temporal scales. The project addresses mathematical and numerical analyses for material problems for which relevant scales range from those usually treated by molecular dynamics all the way up to those most often treated by classical elasticity. The prevalent approach towards developing a multiscale material model couples two or more well known models, e.g., molecular dynamics and classical elasticity, each of which is useful at a different scale, creating a multiscale multi-model. However, the challenges behind such a coupling are formidable and largely arise because the atomistic and continuum models employ nonlocal and local models of force, respectively. The project focuses on a multiscale analysis of the peridynamics materials model. Peridynamics can be used as a transition between molecular dynamics and classical elasticity so that the difficulties encountered when directly coupling those two models are mitigated. In addition, in some situations, peridynamics can be used all by itself as a material model that accurately and efficiently captures the behavior of materials over a wide range of spatial and temporal scales. Peridynamics is well suited to these purposes because it employs a nonlocal model of force, analogous to that of molecular dynamics; furthermore, at sufficiently large length scales and assuming smooth deformation, peridynamics can be approximated by classical elasticity. The project will extend the emerging mathematical and numerical analysis of peridynamics. One goal is to develop a peridynamics-enabled multiscale multi-model that potentially provides a new and more extensive mathematical basis for coupling classical elasticity and molecular dynamics, thus enabling next generation atomistic-to-continuum multiscale simulations. In addition, a rigorous study of nite element discretizations of peridynamics will be considered. Using the fact that peridynamics is spatially derivative free, we will also characterize the space of admissible peridynamic solutions and carry out systematic analyses of the models, in particular rigorously showing how peridynamics encompasses fracture and other failure phenomena. Additional aspects of the project include the mathematical and numerical analysis of peridynamics applied to stochastic peridynamics models. In summary, the project will make feasible mathematically consistent multiscale models for the analysis and design of advanced materials.
Monitoring Erebus volcano's active lava lake; tools, techniques and observations
Peters, Nial John
2015-03-03T23:59:59.000Z
are those that persistently expose magma at the Earth’s surface. In this respect, they encompass many of the popular stereo- types of volcanic activity, exhibiting sustained passive degassing, which is often ac- companied sporadically by varying degrees... serves the crater rim was replaced. The old system was approaching ten years of service, and had become overly com- plex, and unreliable. A combination of extreme winds and corrosive gases makes the crater rim of Erebus an unsuitable site for solar panels...
Lava Hot Springs Space Heating Low Temperature Geothermal Facility | Open
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer Plant Jump to:Landowners and Wind Energy DevelopmentLaurentian Energy Authority JumpEnergy
Quantum Cosmology will need to become a Numerical Subject
Anderson, Edward
2013-01-01T23:59:59.000Z
The inhomogeneous fluctuations that underlie structure formation - galaxies and CMB hotspots - might have been seeded by quantum cosmological fluctuations, as magnified by some inflationary mechanism. The Halliwell-Hawking model for these, as a lower-energy semiclassical limit, is expected to be shared by many theories. E.g. an O((H/m_pl)^2) suppression of power at large scales results from this. This model contains/suppresses very many terms; we want a qualitative understanding of the meaning of these terms and of different regimes resulting from different combinations of them. I study this with toy models that have tractable mathematics: minisuperspace and, especially, relational particle mechanics. In the present Seminar, I consider in particular averaged terms with some lessons from Hartree-Fock approach to Atomic and Molecular Physics. One needs to anchor this on variational principles; treating the subsequent equations is a numerical venture.
Quantum Cosmology will need to become a Numerical Subject
Edward Anderson
2013-06-26T23:59:59.000Z
The inhomogeneous fluctuations that underlie structure formation - galaxies and CMB hotspots - might have been seeded by quantum cosmological fluctuations, as magnified by some inflationary mechanism. The Halliwell-Hawking model for these, as a lower-energy semiclassical limit, is expected to be shared by many theories. E.g. an O((H/m_pl)^2) suppression of power at large scales results from this. This model contains/suppresses very many terms; we want a qualitative understanding of the meaning of these terms and of different regimes resulting from different combinations of them. I study this with toy models that have tractable mathematics: minisuperspace and, especially, relational particle mechanics. In the present Seminar, I consider in particular averaged terms with some lessons from Hartree-Fock approach to Atomic and Molecular Physics. One needs to anchor this on variational principles; treating the subsequent equations is a numerical venture.
Numerical analysis of kinematic soil-pile interaction
Castelli, Francesco; Maugeri, Michele [Department of Civil and Environmental Engineering, University of Catania, Viale Andrea Doria no. 6, 95125, Catania (Italy); Mylonakis, George [Department of Civil Engineering, University of Patras, Rio GR-26500, Patras (Greece)
2008-07-08T23:59:59.000Z
In the present study, the response of singles pile to kinematic seismic loading is investigated using the computer program SAP2000. The objectives of the study are: (1) to develop a numerical model that can realistically simulate kinematic soil-structure interaction for piles accounting for discontinuity conditions at the pile-soil interface, energy dissipation and wave propagation; (2) to use the model for evaluating kinematic interaction effects on pile response as function of input ground motion; and (3) to present a case study in which theoretical predictions are compared with results obtained from other formulations. To evaluate the effects of kinematic loading, the responses of both the free-field soil (with no piles) and the pile were compared. Time history and static pushover analyses were conducted to estimate the displacement and kinematic pile bending under seismic loadings.
Numerical computations of the dynamics of fluidic membranes and vesicles
Barrett, John W; Nürnberg, Robert
2015-01-01T23:59:59.000Z
Vesicles and many biological membranes are made of two monolayers of lipid molecules and form closed lipid bilayers. The dynamical behaviour of vesicles is very complex and a variety of forms and shapes appear. Lipid bilayers can be considered as a surface fluid and hence the governing equations for the evolution include the surface (Navier--)Stokes equations, which in particular take the membrane viscosity into account. The evolution is driven by forces stemming from the curvature elasticity of the membrane. In addition, the surface fluid equations are coupled to bulk (Navier--)Stokes equations. We introduce a parametric finite element method to solve this complex free boundary problem, and present the first three dimensional numerical computations based on the full (Navier--)Stokes system for several different scenarios. For example, the effects of the membrane viscosity, spontaneous curvature and area difference elasticity (ADE) are studied. In particular, it turns out, that even in the case of no viscosit...
Numerical integration of thermal noise in relativistic hydrodynamics
Clint Young
2013-06-03T23:59:59.000Z
Thermal fluctuations affect the dynamics of systems near critical points, the evolution of the early universe, and two-particle correlations in heavy-ion collisions. For the latter, numerical simulations of nearly-ideal, relativistic fluids are necessary. The correlation functions of noise in relativistic fluids are calculated, stochastic integration of the noise in 3+1-dimensional viscous hydrodynamics is implemented, and the effect of noise on observables in heavy-ion collisions is discussed. Thermal fluctuations will cause significant variance in the event-by-event distributions of integrated v2 while changing average values even when using the same initial conditions, suggesting that including thermal noise will lead to refitting of the hydrodynamical parameters with implications for understanding the physics of hot QCD.
Direct numerical simulation of pattern formation in subaqueous sediment
Kidanemariam, Aman G
2014-01-01T23:59:59.000Z
We present results of direct numerical simulation of incompressible fluid flow over a thick bed of mobile, spherically-shaped particles. The algorithm is based upon the immersed boundary technique for fluid-solid coupling and uses a soft-sphere model for the solid-solid contact. Two parameter points in the laminar flow regime are chosen, leading to the emergence of sediment patterns classified as `small dunes', while one case under turbulent flow conditions leads to `vortex dunes' with significant flow separation on the lee side. Wavelength, amplitude and propagation speed of the patterns extracted from the spanwise-averaged fluid-bed interface are found to be consistent with available experimental data. The particle transport rates are well represented by available empirical models for flow over a plane sediment bed in both the laminar and the turbulent regimes.
Progress report on LBL's numerical modeling studies on Cerro Prieto
Halfman-Dooley, S.E.; Lippman, M.J.; Bodvarsson, G.S.
1989-04-01T23:59:59.000Z
An exploitation model of the Cerro Prieto geothermal system is needed to assess the energy capacity of the field, estimate its productive lifetime and develop an optimal reservoir management plan. The model must consider the natural state (i.e., pre-exploitation) conditions of the system and be able to predict changes in the reservoir thermodynamic conditions (and fluid chemistry) in response to fluid production (and injection). This paper discusses the results of a three-dimensional numerical simulation of the natural state conditions of the Cerro Prieto field and compares computed and observed pressure and temperature/enthalpy changes for the 1973--1987 production period. 16 refs., 24 figs., 2 tabs.
Numerical simulation of laminar reacting flows with complex chemistry
Day, Marcus S.; Bell, John B.
1999-12-01T23:59:59.000Z
We present an adaptive algorithm for low Mach number reacting flows with complex chemistry. Our approach uses a form of the low Mach number equations that discretely conserves both mass and energy. The discretization methodology is based on a robust projection formulation that accommodates large density contrasts. The algorithm uses an operator-split treatment of stiff reaction terms and includes effects of differential diffusion. The basic computational approach is embedded in an adaptive projection framework that uses structured hierarchical grids with subcycling in time that preserves the discrete conservation properties of the underlying single-grid algorithm. We present numerical examples illustrating the performance of the method on both premixed and non-premixed flames.
Spherically symmetric cosmological spacetimes with dust and radiation — numerical implementation
Lim, Woei Chet [Department of Mathematics, University of Waikato, Private Bag 3105, Hamilton 3240 (New Zealand); Regis, Marco [Dipartimento di Fisica, Università di Torino and INFN, Torino (Italy); Clarkson, Chris, E-mail: wclim@waikato.ac.nz, E-mail: regis@to.infn.it, E-mail: chris.clarkson@gmail.com [Astrophysics, Cosmology and Gravity Centre, and Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town (South Africa)
2013-10-01T23:59:59.000Z
We present new numerical cosmological solutions of the Einstein Field Equations. The spacetime is spherically symmetric with a source of dust and radiation approximated as a perfect fluid. The dust and radiation are necessarily non-comoving due to the inhomogeneity of the spacetime. Such a model can be used to investigate non-linear general relativistic effects present during decoupling or big-bang nucleosynthesis, as well as for investigating void models of dark energy with isocurvature degrees of freedom. We describe the full evolution of the spacetime as well as the redshift and luminosity distance for a central observer. After demonstrating accuracy of the code, we consider a few example models, and demonstrate the sensitivity of the late time model to the degree of inhomogeneity of the initial radiation contrast.
Explicit Gravitational Radiation in Hyperbolic Systems for Numerical Relativity
C. Bona; C. Palenzuela
2002-02-28T23:59:59.000Z
A method for studying the causal structure of space-time evolution systems is presented. This method, based on a generalization of the well known Riemann problem, provides intrinsic results which can be interpreted from the geometrical point of view. A one-parameter family of hyperbolic evolution systems is presented and the physical relevance of their characteristic speeds and eigenfields is discussed. The two degrees of freedom corresponding to gravitational radiation are identified in an intrinsic way, independent of the space coordinate system. A covariant interpretation of these degrees of freedom is provided in terms of the geometry of the wave fronts. The requirement of a consistent geometrical interpretation of the gravitational radiation degrees of freedom is used to solve the ordering ambiguity that arises when obtaining first order evolution systems from the second order field equations. This achievement provides a benchmark which can be used to check both the existing and future first order hyperbolic formalisms for Numerical Relativity.
Numerical evaluation of effective unsaturated hydraulic properties for fractured rocks
Lu, Zhiming [Los Alamos National Laboratory; Kwicklis, Edward M [Los Alamos National Laboratory
2009-01-01T23:59:59.000Z
To represent a heterogeneous unsaturated fractured rock by its homogeneous equivalent, Monte Carlo simulations are used to obtain upscaled (effective) flow properties. In this study, we present a numerical procedure for upscaling the van Genuchten parameters of unsaturated fractured rocks by conducting Monte Carlo simulations of the unsaturated flow in a domain under gravity-dominated regime. The simulation domain can be chosen as the scale of block size in the field-scale modeling. The effective conductivity is computed from the steady-state flux at the lower boundary and plotted as a function of the averaging pressure head or saturation over the domain. The scatter plot is then fitted using van Genuchten model and three parameters, i.e., the saturated conductivity K{sub s}, the air-entry parameter {alpha}, the pore-size distribution parameter n, corresponding to this model are considered as the effective K{sub s}, effective {alpha}, and effective n, respectively.
Numerical investigation of the threshold for primordial black hole formation
J. C. Niemeyer
1998-06-02T23:59:59.000Z
First results of a numerical investigation of primordial black hole formation in the radiation dominated phase of the Early Universe are presented. The simulations follow the gravitational collapse of three different families of high-amplitude density fluctuations imposed at the time of horizon crossing. The threshold for black hole formation, \\delta_{c} \\approx 0.7, is found to be nearly identical for all perturbation families if the control parameter, \\delta, is chosen as the total excess mass within the initial horizon volume. Furthermore, we demonstrate that the scaling of black hole mass with distance from the formation threshold, known to occur in near-critical gravitational collapse, applies to primordial black hole formation.
A fast direct numerical simulation method for characterising hydraulic roughness
Chung, Daniel; MacDonald, Michael; Hutchins, Nicholas; Ooi, Andrew
2015-01-01T23:59:59.000Z
We describe a fast direct numerical simulation (DNS) method that promises to directly characterise the hydraulic roughness of any given rough surface, from the hydraulically smooth to the fully rough regime. The method circumvents the unfavourable computational cost associated with simulating high-Reynolds-number flows by employing minimal-span channels (Jimenez & Moin 1991). Proof-of-concept simulations demonstrate that flows in minimal-span channels are sufficient for capturing the downward velocity shift, that is, the Hama roughness function, predicted by flows in full-span channels. We consider two sets of simulations, first with modelled roughness imposed by body forces, and second with explicit roughness described by roughness-conforming grids. Owing to the minimal cost, we are able to conduct DNSs with increasing roughness Reynolds numbers while maintaining a fixed blockage ratio, as is typical in full-scale applications. The present method promises a practical, fast and accurate tool for character...
Numerically Tracking Contact Discontinuities with an Introduction for GPU Programming
Davis, Sean L [Los Alamos National Laboratory
2012-08-17T23:59:59.000Z
We review some of the classic numerical techniques used to analyze contact discontinuities and compare their effectiveness. Several finite difference methods (the Lax-Wendroff method, a Multidimensional Positive Definite Advection Transport Algorithm (MPDATA) method and a Monotone Upstream Scheme for Conservation Laws (MUSCL) scheme with an Artificial Compression Method (ACM)) as well as the finite element Streamlined Upwind Petrov-Galerkin (SUPG) method were considered. These methods were applied to solve the 2D advection equation. Based on our results we concluded that the MUSCL scheme produces the sharpest interfaces but can inappropriately steepen the solution. The SUPG method seems to represent a good balance between stability and interface sharpness without any inappropriate steepening. However, for solutions with discontinuities, the MUSCL scheme is superior. In addition, a preliminary implementation in a GPU program is discussed.
MHD Remote Numerical Simulations: Evolution of Coronal Mass Ejections
L. Hernandez-Cervantes; A. Santillan; A. R. Gonzalez-Ponce
2008-12-22T23:59:59.000Z
Coronal mass ejections (CMEs) are solar eruptions into interplanetary space of as much as a few billion tons of plasma, with embedded magnetic fields from the Sun's corona. These perturbations play a very important role in solar--terrestrial relations, in particular in the spaceweather. In this work we present some preliminary results of the software development at the Universidad Nacional Autonoma de Mexico to perform Remote MHD Numerical Simulations. This is done to study the evolution of the CMEs in the interplanetary medium through a Web-based interface and the results are store into a database. The new astrophysical computational tool is called the Mexican Virtual Solar Observatory (MVSO) and is aimed to create theoretical models that may be helpful in the interpretation of observational solar data.
Numerical Study of Induced False Vacuum Decay at High Energies
A. N. Kuznetsov; P. G. Tinyakov
1995-11-02T23:59:59.000Z
We calculate numerically the probability $\\exp[ {1\\over\\lambda} F(E/E_{sph},N/N_{sph})]$ of the false vacuum decay in the massive four-dimensional $-\\lambda\\phi^4$ model from multiparticle initial states with fixed number of particles $N$ and energy $E$ greater than the height of the barrier $E_{sph}$. We find that at $E\\lsim 3E_{sph}$ and $N\\lsim 0.4N_{sph}$ the decay is classically forbidden and thus is exponentially suppressed. We argue that the classically forbidden region extends at small $N$ at least up to $E\\sim 10 E_{sph}$ and, most likely, to all energies. Our data suggest that the false vacuum decay induced by two-particle collisions is exponentially suppressed at all energies.
A numerical model of aerosol scavenging: Part 1, Microphysics parameterization
Molenkamp, C.R.; Bradley, M.M.
1991-09-01T23:59:59.000Z
We have developed a three-dimensional numerical model (OCTET) to simulate the dynamics and microphysics of clouds and the transport, diffusion and precipitation scavenging of aerosol particles. In this paper we describe the cloud microphysics and scavenging parameterizations. The representation of cloud microphysics is a bulk- water parameterization which includes water vapor and five types of hydrometeors (cloud droplets, rain drops, ice crystals, snow, and graupel). A parallel parameterization represents the scavenging interactions between pollutant particles and hydrometeors including collection of particles because of condensation nucleation, Brownian and phoretic attachment, and inertial capture, resuspension because of evaporation and sublimation; and transfer interactions where particles collected by one type of hydrometeor are transferred to another type of freezing, melting, accretion, riming and autoconversion.
Electromagnetic Pulse Propagation over Nonuniform Earth Surface: Numerical Simulation
Alexei V. Popov; Vladimir V. Kopeikin
2007-04-14T23:59:59.000Z
We simulate EM pulse propagation along the nonuniform earth surface using so called time-domain parabolic equation. To solve it by finite differences, we introduce a time-domain analog of the impedance boundary condition and a nonlocal BC of transparency reducing open computational domain to a strip of finite width. Numerical examples demonstrate influence of soil conductivity on the wide-band pulse waveform. For a high-frequency modulated EM pulse, we develop an asymptotic approach based on the ray structure of the monochromatic wave field at carrier frequency. This radically diminishes the computation costs and allows for pulsed wave field calculation in vast domains measured by tens of thousands wavelengths.
Topological insulators and C*-algebras: Theory and numerical practice
Hastings, Matthew B., E-mail: mahastin@microsoft.com [Department of Physics, Duke University, Durham, NC 27708 (United States); Microsoft Research, Station Q, Elings Hall, University of California, Santa Barbara, CA 93106 (United States); Department of Mathematics and Statistics, University of New Mexico, Albuquerque, NM 87131 (United States); Loring, Terry A. [Department of Physics, Duke University, Durham, NC 27708 (United States); Microsoft Research, Station Q, Elings Hall, University of California, Santa Barbara, CA 93106 (United States); Department of Mathematics and Statistics, University of New Mexico, Albuquerque, NM 87131 (United States)
2011-07-15T23:59:59.000Z
Research Highlights: > We classify topological insulators using C* algebras. > We present new K-theory invariants. > We develop efficient numerical algorithms based on this technique. > We observe unexpected quantum phase transitions using our algorithm. - Abstract: We apply ideas from C*-algebra to the study of disordered topological insulators. We extract certain almost commuting matrices from the free Fermi Hamiltonian, describing band projected coordinate matrices. By considering topological obstructions to approximating these matrices by exactly commuting matrices, we are able to compute invariants quantifying different topological phases. We generalize previous two dimensional results to higher dimensions; we give a general expression for the topological invariants for arbitrary dimension and several symmetry classes, including chiral symmetry classes, and we present a detailed K-theory treatment of this expression for time reversal invariant three dimensional systems. We can use these results to show non-existence of localized Wannier functions for these systems. We use this approach to calculate the index for time-reversal invariant systems with spin-orbit scattering in three dimensions, on sizes up to 12{sup 3}, averaging over a large number of samples. The results show an interesting separation between the localization transition and the point at which the average index (which can be viewed as an 'order parameter' for the topological insulator) begins to fluctuate from sample to sample, implying the existence of an unsuspected quantum phase transition separating two different delocalized phases in this system. One of the particular advantages of the C*-algebraic technique that we present is that it is significantly faster in practice than other methods of computing the index, allowing the study of larger systems. In this paper, we present a detailed discussion of numerical implementation of our method.
NUMERICAL STUDY OF THE VISHNIAC INSTABILITY IN SUPERNOVA REMNANTS
Michaut, C.; Cavet, C.; Bouquet, S. E.; Roy, F.; Nguyen, H. C., E-mail: claire.michaut@obspm.fr [LUTH, Observatoire de Paris, CNRS, Universite Paris-Diderot, F-92190 Meudon (France)
2012-11-10T23:59:59.000Z
The Vishniac instability is thought to explain the complex structure of radiative supernova remnants in their Pressure-Driven Thin Shell (PDTS) phase after a blast wave (BW) has propagated from a central explosion. In this paper, the propagation of the BW and the evolution of the PDTS stage are studied numerically with the two-dimensional (2D) code HYDRO-MUSCL for a finite-thickness shell expanding in the interstellar medium (ISM). Special attention is paid to the adiabatic index, {gamma}, and three distinct values are taken for the cavity ({gamma}{sub 1}), the shell ({gamma}{sub 2}), and the ISM ({gamma}{sub 3}) with the condition {gamma}{sub 2} < {gamma}{sub 1}, {gamma}{sub 3}. This low value of {gamma}{sub 2} accounts for the high density in the shell achieved by a strong radiative cooling. Once the spherical background flow is obtained, the evolution of a 2D-axisymmetric perturbation is computed from the linear to the nonlinear regime. The overstable mechanism, previously demonstrated theoretically by E. T. Vishniac in 1983, is recovered numerically in the linear stage and is expected to produce and enhance anisotropies and clumps on the shock front, leading to the disruption of the shell in the nonlinear phase. The period of the increasing oscillations and the growth rate of the instability are derived from several points of view (the position of the perturbed shock front, mass fluxes along the shell, and density maps), and the most unstable mode differing from the value given by Vishniac is computed. In addition, the influence of several parameters (the Mach number, amplitude and wavelength of the perturbation, and adiabatic index) is examined and for wavelengths that are large enough compared to the shell thickness, the same conclusion arises: in the late stage of the evolution of the radiative supernova remnant, the instability is dampened and the angular initial deformation of the shock front is smoothed while the mass density becomes uniform with the angle. As a result, our model shows that the supernova remnant returns to a stable evolution and the Vishniac instability does not lead to the fragmentation of the shock as predicted by the theory.
Probing Modified Gravity with Atom-Interferometry: a Numerical Approach
Schlogel, Sandrine; Fuzfa, Andre
2015-01-01T23:59:59.000Z
Refined constraints on chameleon theories are calculated for atom-interferometry experiments, using a numerical approach consisting in solving for a four-region model the static and spherically symmetric Klein-Gordon equation for the chameleon field. By modeling not only the test mass and the vacuum chamber but also its walls and the exterior environment, the method allows to probe new effects on the scalar field profile and the induced acceleration of atoms. In the case of a weakly perturbing test mass, the effect of the wall is to enhance the field profile and to lower the acceleration inside the chamber by up to one order of magnitude. In the thin-shell regime, significant deviations from the analytical estimations are found, even when measurements are realized in the immediate vicinity of the test mass. Close to the vacuum chamber wall, the acceleration becomes negative and potentially measurable. This prediction could be used to discriminate between fifth-force effects and systematic experimental uncerta...
Numerical simulation of linear fiction welding (LFW) processes
Fratini, L.; La Spisa, D. [University of Palermo-Dept. of Industrial engineering (Italy)
2011-05-04T23:59:59.000Z
Solid state welding processes are becoming increasingly important due to a large number of advantages related to joining ''unweldable'' materials and in particular light weight alloys. Linear friction welding (LFW) has been used successfully to bond non-axisymmetric components of a range of materials including titanium alloys, steels, aluminum alloys, nickel, copper, and also dissimilar material combinations. The technique is useful in the research of quality of the joints and in reducing costs of components and parts of the aeronautic and automotive industries.LFW involves parts to be welded through the relative reciprocating motion of two components under an axial force. In such process the heat source is given by the frictional forces work decaying into heat determining a local softening of the material and proper bonding conditions due to both the temperature increase and the local pressure of the two edges to be welded. This paper is a comparative test between the numerical model in two dimensions, i.e. in plane strain conditions, and in three dimensions of a LFW process of AISI1045 steel specimens. It must be observed that the 3D model assures a faithful simulation of the actual threedimensional material flow, even if the two-dimensional simulation computational times are very short, a few hours instead of several ones as the 3D model. The obtained results were compared with experimental values found out in the scientific literature.
Numerical Relativity in Spherical Polar Coordinates: Off-center Simulations
Thomas W. Baumgarte; Pedro J. Montero; Ewald Müller
2015-06-03T23:59:59.000Z
We have recently presented a new approach for numerical relativity simulations in spherical polar coordinates, both for vacuum and for relativistic hydrodynamics. Our approach is based on a reference-metric formulation of the BSSN equations, a factoring of all tensor components, as well as a partially implicit Runge-Kutta method, and does not rely on a regularization of the equations, nor does it make any assumptions about the symmetry across the origin. In order to demonstrate this feature we present here several off-centered simulations, including simulations of single black holes and neutron stars whose center is placed away from the origin of the coordinate system, as well as the asymmetric head-on collision of two black holes. We also revisit our implementation of relativistic hydrodynamics and demonstrate that a reference-metric formulation of hydrodynamics together with a factoring of all tensor components avoids problems related to the coordinate singularities at the origin and on the axes. As a particularly demanding test we present results for a shock wave propagating through the origin of the spherical polar coordinate system.
DIPOLE COLLAPSE AND DYNAMO WAVES IN GLOBAL DIRECT NUMERICAL SIMULATIONS
Schrinner, Martin; Dormy, Emmanuel [MAG (ENS/IPGP), LRA, Ecole Normale Superieure, 24 Rue Lhomond, 75252 Paris Cedex 05 (France); Petitdemange, Ludovic, E-mail: martin@schrinner.eu [Previously at Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, 69117 Heidelberg, Germany. (Germany)
2012-06-20T23:59:59.000Z
Magnetic fields of low-mass stars and planets are thought to originate from self-excited dynamo action in their convective interiors. Observations reveal a variety of field topologies ranging from large-scale, axial dipoles to more structured magnetic fields. In this article, we investigate more than 70 three-dimensional, self-consistent dynamo models in the Boussinesq approximation obtained by direct numerical simulations. The control parameters, the aspect ratio, and the mechanical boundary conditions have been varied to build up this sample of models. Both strongly dipolar and multipolar models have been obtained. We show that these dynamo regimes in general can be distinguished by the ratio of a typical convective length scale to the Rossby radius. Models with a predominantly dipolar magnetic field were obtained, if the convective length scale is at least an order of magnitude larger than the Rossby radius. Moreover, we highlight the role of the strong shear associated with the geostrophic zonal flow for models with stress-free boundary conditions. In this case the above transition disappears and is replaced by a region of bistability for which dipolar and multipolar dynamos coexist. We interpret our results in terms of dynamo eigenmodes using the so-called test-field method. We can thus show that models in the dipolar regime are characterized by an isolated 'single mode'. Competing overtones become significant as the boundary to multipolar dynamos is approached. We discuss how these findings relate to previous models and to observations.
Numerical simulations of super-luminous supernovae of type IIn
Dessart, Luc; Hillier, D John
2015-01-01T23:59:59.000Z
We present numerical simulations that include 1-D Eulerian multi-group radiation-hydrodynamics, 1-D non-LTE radiative transfer, and 2-D polarised radiative transfer for super-luminous interacting supernovae (SNe). Our reference model is a ~10Msun inner shell with 10^51erg ramming into a ~3Msun cold outer shell (the circumstellar-medium, or CSM) that extends from 10^15cm to 2x10^16cm and moves at 100km/s. We discuss the light curve evolution, which cannot be captured adequately with a grey approach. In these interactions, the shock-crossing time through the optically-thick CSM is much longer than the photon diffusion time. Radiation is thus continuously leaking from the shock through the CSM, in disagreement with the shell-shocked model that is often invoked. Our spectra redden with time, with a peak distribution in the near-UV during the first month gradually shifting to the optical range over the following year. Initially Balmer lines exhibit a narrow line core and the broad line wings that are characteristi...
Topological Insulators and C^*-Algebras: Theory and Numerical Practice
M. B. Hastings; T. A. Loring
2010-12-05T23:59:59.000Z
We apply ideas from $C^*$-algebra to the study of disordered topological insulators. We extract certain almost commuting matrices from the free Fermi Hamiltonian, describing band projected coordinate matrices. By considering topological obstructions to approximating these matrices by exactly commuting matrices, we are able to compute invariants quantifying different topological phases. We generalize previous two dimensional results to higher dimensions; we give a general expression for the topological invariants for arbitrary dimension and several symmetry classes, including chiral symmetry classes, and we present a detailed $K$-theory treatment of this expression for time reversal invariant three dimensional systems. We can use these results to show non-existence of localized Wannier functions for these systems. We use this approach to calculate the index for time-reversal invariant systems with spin-orbit scattering in three dimensions, on sizes up to $12^3$, averaging over a large number of samples. The results show an interesting separation between the localization transition and the point at which the average index (which can be viewed as an "order parameter" for the topological insulator) begins to fluctuate from sample too sample, implying the existence of an unsuspected quantum phase transition separating two different delocalized phases in this system. One of the particular advantages of the $C^*$-algebraic technique that we present is that it is significantly faster in practice than other methods of computing the index, allowing the study of larger systems. In this paper, we present a detailed discussion of numerical implementation of our method.
Numerical simulations of X-rays Free Electron Lasers (XFEL)
Paolo Antonelli; Agissilaos Athanassoulis; Zhongyi Huang; Peter A. Markowich
2014-06-17T23:59:59.000Z
We study a nonlinear Schr\\"odinger equation which arises as an effective single particle model in X-ray Free Electron Lasers (XFEL). This equation appears as a first-principles model for the beam-matter interactions that would take place in an XFEL molecular imaging experiment in \\cite{frat1}. Since XFEL is more powerful by several orders of magnitude than more conventional lasers, the systematic investigation of many of the standard assumptions and approximations has attracted increased attention. In this model the electrons move under a rapidly oscillating electromagnetic field, and the convergence of the problem to an effective time-averaged one is examined. We use an operator splitting pseudo-spectral method to investigate numerically the behaviour of the model versus its time-averaged version in complex situations, namely the energy subcritical/mass supercritical case, and in the presence of a periodic lattice. We find the time averaged model to be an effective approximation, even close to blowup, for fast enough oscillations of the external field. This work extends previous analytical results for simpler cases \\cite{xfel1}.
Numerical simulations of compressively driven interstellar turbulence: I. Isothermal gas
Schmidt, Wolfram; Hupp, Markus; Kern, Sebastian; Niemeyer, Jens C
2008-01-01T23:59:59.000Z
We performed numerical simulations of supersonic isothermal turbulence driven by mostly compressive large-scale forcing, using both a static grid and adaptive mesh refinement with an effective resolution N=768^3. After a transient phase dominated by shocks, turbulence evolves into a steady state with an RMS Mach number about 2.5, in which cloud-like structures of over-dense gas are surrounded by highly rarefied gas. The index of the turbulence energy spectrum function beta = 2.0 in the shock-dominated phase. As the flow approaches statistical equilibrium, the spectrum flattens, with beta = 1.9. For the scaling exponent of the root mean square velocity fluctuation, we obtain gamma = 0.43 from the velocity structure functions of second order. These results are well within the range of observed scaling properties for the velocity dispersion in molecular clouds. Calculating structure functions of order p=1,...,5, we find for all scaling exponents significant deviations from the Kolmogorov-Burgers model proposed b...
Effective viscosity of active suspensions: Three-dimensional numerical modeling
Levan Jibuti; Walter Zimmermann; Salima Rafaï; Philippe Peyla
2014-12-10T23:59:59.000Z
A three-dimensional model is proposed for Chlamydomonas Reinhardtii swimming with a breaststroke-like beating of its two flagella. The model reveals unusual angular orbits of the active swimmer under a linear shear flow. Namely, the swimmer sustains orientation transiently across the flow when flagella plane is perpendicular to the shear plane, and amplify the shear-induced rotation along the flow. Such behavior is a result of the interplay between shear-induced deformation and swimmer's periodic beating motion that exerts internal torques on the torque-free swimmer. This particular behavior has some significant consequences on the rheological properties of the suspension that tends to confirm previous experimental results [Phys. Rev. Lett. 104, 098102 (2010)]. We calculated the intrinsic viscosity of the suspension with such isolated modeled microswimmers (dilute case) in shear flow using numerical simulations based on Rotne-Prager approximation. The results show an increased intrinsic viscosity for active swimmer suspensions in comparison to non-active ones in accordance with previous experimental measurements. A major enhancement of the active swimmer viscosity occurs due to the effectively extended shape of the deformable swimming cells. We also recover the experimentally observed shear thinning behavior.
Numerical study of energy diffusion in King models
Tom Theuns
1995-11-07T23:59:59.000Z
The energy diffusion coefficients D_n(E) (n=1,2) for a system of equal mass particles moving self-consistently in an N-body realisation of a King model are computed from the probability per unit time, P(E, Delta E), that a star with initial energy E will undergo an energy change Delta E. In turn, P is computed from the number of times during the simulation that a particle in a state of given energy undergoes a transition to another state. These particle states are defined directly from the time evolution of E by identifying them with the event occuring between two local maxima in the E(t) curve. If one assumes next that energy changes are uncorrelated between different states, one can use diffusion theory to compute D_n(E). The simulations employ N=512, 2048,... , 32768 particles and are performed using an implementation of Aarseth's direct integrator N-body1 on a massively parallel computer. The more than seven million transitions measured in the largest N simulation provide excellent statistics. The numerically determined D(E)'s are compared against their theoretical counterparts which are computed from phase-space averaged rates of energy change due to independent binary encounters. The overall agreement between them is impressive over most of the energy range, notwithstanding the very different type of approximations involved, giving considerable support to the valid usage of these theoretical expressions to simulate dynamical evolution in Fokker-Planck type calculations.
Numerical studies on the geomechanical stability ofhydrate-bearing sediments
Rutqvist, Jonny; Moridis, George J.
2007-05-01T23:59:59.000Z
The thermal and mechanical loading of oceanicHydrate-Bearing Sediments (HBS) can result in hydrate dissociation and asignificant pressure increase, with potentially adverse consequences onthe integrity and stability of the wellbore assembly, the HBS, and thebounding formations. The perception of HBS instability, coupled withinsufficient knowledge of their geomechanical behavior and the absence ofpredictive capabilities, have resulted in a strategy of avoidance of HBSwhen locating offshore production platforms, and can impede thedevelopment of hydrate deposits as gas resources.In this study weinvestigate in three cases of coupled hydraulic, thermodynamic andgeomechanical behavior of oceanic hydrate-bearing sediments. The firstinvolves hydrate heating as warm fluids from deeper conventionalreservoirs ascend to the ocean floor through uninsulated pipesintersecting the HBS. The second case describes system response duringgas production from a hydrate deposit, and the third involves mechanicalloading caused by the weight of structures placed on the ocean flooroverlying hydrate-bearing sediments.For the analysis of the geomechanicalstability of HBS, we developed and used a numerical model that integratesa commercial geomechanical code and a simulator describing the coupledprocesses of fluid flow, heat transport and thermodynamic behavior in theHBS. Our simulation results indicate that the stability of HBS in thevicinity of warm pipes may be significantly affected, especially if thesediments are unconsolidated and more compressible. Gas production fromoceanic deposits may also affect the geomechanical stability of HBS underthe conditions that are deemed desirablefor production. Conversely, theincreased pressure caused by the weight of structures on the ocean floorincreases the stability of underlying hydrates.
Measurement and numerical calculation of Rubidium Rydberg Stark spectra
Grimmel, Jens; Karlewski, Florian; Jessen, Florian; Reinschmidt, Malte; Sándor, Nóra; Fortágh, József
2015-01-01T23:59:59.000Z
We report on the measurement of Stark shifted energy levels of $^{87}$Rb Rydberg atoms in static electric fields by means of electromagnetically induced transparency (EIT). Electric field strengths of up to 500V/cm, ranging beyond the classical ionisation threshold, were applied using electrodes inside a glass cell with rubidium vapour. Stark maps for principal quantum numbers $n=35$ and $n=70$ have been obtained with high signal-to-noise ratio for comparison with results from ab initio calculations following the method described in [M. L. Zimmerman et al., Phys. Rev. A 20, 2251 (1979)], which was originally only verified for states around $n=15$. We also calculate the dipole matrix elements between low-lying states and Stark shifted Rydberg states to give a theoretical estimate of the relative strength of the EIT signal. The present work significantly extends the experimental verification of this numerical method in the range of both high principal quantum numbers and high electric fields with an accuracy of...
Numerical evaluation of multi-gluon amplitudes for High Energy Factorization
Bury, M
2015-01-01T23:59:59.000Z
We present a program to evaluate tree-level multi-gluon amplitudes with up to two of them off-shell. Furthermore, it evaluates squared amplitudes summed over colors and helicities for up to six external gluons. It employs both analytic expressions, obtained via BCFW recursion, and numerical BCFW recursion. It has been validated numerically with the help of an independent program employing numerical Dyson-Schwinger recursion.
13.002J Introduction to Numeric Analysis for Engineering, Spring 2003
Leonard, John J.
An introduction to the formulation, methodology, and techniques for numerical solution of engineering problems. Fundamental principles of digital computing and the implications for algorithm accuracy and stability. Error ...
Mathiesen, Patrick James
2013-01-01T23:59:59.000Z
Evaluation of numerical weather prediction solar irradiancecycle: The RUC. Monthly Weather Review, 132 (2), 495-518.representations. Monthly Weather Review, 139 (6), 1972-1995.
High Resolution Backside Imaging and Thermography using a Numerical Aperture Increasing Lens
High Resolution Backside Imaging and Thermography using a Numerical Aperture Increasing Lens M. S, representing the highest resolution subsurface thermography to date. Keywords: thermal imaging, high
Numerical Methods for Forward and Inverse Problems in Discontinuous Media
Timothy P. Chartier
2011-03-08T23:59:59.000Z
The research emphasis under this grantâ??s funding is in the area of algebraic multigrid methods. The research has two main branches: 1) exploring interdisciplinary applications in which algebraic multigrid can make an impact and 2) extending the scope of algebraic multigrid methods with algorithmic improvements that are based in strong analysis.The work in interdisciplinary applications falls primarily in the field of biomedical imaging. Work under this grant demonstrated the effectiveness and robustness of multigrid for solving linear systems that result from highly heterogeneous finite element method models of the human head. The results in this work also give promise to medical advances possible with software that may be developed. Research to extend the scope of algebraic multigrid has been focused in several areas. In collaboration with researchers at the University of Colorado, Lawrence Livermore National Laboratory, and Los Alamos National Laboratory, the PI developed an adaptive multigrid with subcycling via complementary grids. This method has very cheap computing costs per iterate and is showing promise as a preconditioner for conjugate gradient. Recent work with Los Alamos National Laboratory concentrates on developing algorithms that take advantage of the recent advances in adaptive multigrid research. The results of the various efforts in this research could ultimately have direct use and impact to researchers for a wide variety of applications, including, astrophysics, neuroscience, contaminant transport in porous media, bi-domain heart modeling, modeling of tumor growth, and flow in heterogeneous porous media. This work has already led to basic advances in computational mathematics and numerical linear algebra and will continue to do so into the future.
Numerical controlled polishing, continued force wear and part correction experiments
Hannah, P.R.; Day, R.D.; Hatch, D.J.; McClure, E.R.
1994-09-01T23:59:59.000Z
This abstract reports the near completion of the first phase of this program. It is the aim of this program to provide the operator of a N/C diamond turning machine or N/C grinding machine (jig grinder) with the wear characteristics necessary to achieve uniform material removal. The second phase of this program addresses a different problem, although solving this problem is highly dependent on the results of the first phase. Diamond turned, or any lathe turned surface, exhibits regular tool marks due to the tool passing over the surface being cut. Changes in depth of cut, feed rate and work rpm will change the character of these groves, but will not eliminate them. Optical surfaces produced by this process exhibit increased scattering as the light wavelength decreases limiting their use; at least for optical purposes, to IR and some visible applications. Utilizing wear information gathered in the first part of this program we will attempt to reduce these residual tool marks by polishing. The polishing of diamond turned surfaces is not new. Diamond turned metal surfaces, especially in electroless nickel and high phosphorus nickel electroplate have been polished to improve their scatter characteristics. What we believe is unique is the use of a spherical wheel, rotating on axis and being moved over the part in a prescribed manner by numerical control. Over the past year we have made some major changes in our polishing methods and procedures. We have listed below these changes, as a refresher for the reader as to our previous procedures. These changes will be addressed in the body of the text.
Representing Cloud Processing of Aerosol in Numerical Models
Mechem, D.B.; Kogan, Y.L.
2005-03-18T23:59:59.000Z
The satellite imagery in Figure 1 provides dramatic examples of how aerosol influences the cloud field. Aerosol from ship exhaust can serve as nucleation centers in otherwise cloud-free regions, forming ship tracks (top image), or can enhance the reflectance/albedo in already cloudy regions. This image is a demonstration of the first indirect effect, in which changes in aerosol modulate cloud droplet radius and concentration, which influences albedo. It is thought that, through the effects it has on precipitation (drizzle), aerosol can also affect the structure and persistence of planetary boundary layer (PBL) clouds. Regions of cellular convection, or open pockets of cloudiness (bottom image) are thought to be remnants of strongly drizzling PBL clouds. Pockets of Open Cloudiness (POCs) (Stevens et al. 2005) or Albrecht's ''rifts'' are low cloud fraction regions characterized by anomalously low aerosol concentrations, implying they result from precipitation. These features may in fact be a demonstration of the second indirect effect. To accurately represent these clouds in numerical models, we have to treat the coupled cloud-aerosol system. We present the following series of mesoscale and large eddy simulation (LES) experiments to evaluate the important aspects of treating the coupled cloud-aerosol problem. 1. Drizzling and nondrizzling simulations demonstrate the effect of drizzle on a mesoscale forecast off the California coast. 2. LES experiments with explicit (bin) microphysics gauge the relative importance of the shape of the aerosol spectrum on the 3D dynamics and cloud structure. 3. Idealized mesoscale model simulations evaluate the relative roles of various processes, sources, and sinks.
Numerical study and optimization of a diffraction grating for surface plasmon excitation
Floreano, Dario
Numerical study and optimization of a diffraction grating for surface plasmon excitation Ga¨etan L Laboratory EPFL-STI-NAM, Station 11, CH-1015 Lausanne, Switzerland ABSTRACT The numerical study of plasmonic plasmon polariton wave on a gold-air interface by a diffraction grating. Our calculations are performed
Maps preserving the joint numerical radius distance of operators Chi-Kwong Li
Li, Chi-Kwong
Maps preserving the joint numerical radius distance of operators Chi-Kwong Li and Edward Poon Dedicated to Professor David Lutzer on the occasion of his retirement. Abstract Denote the joint numerical radius of an m-tuple of bounded operators A = (A1, . . . , Am) by w(A). We give a complete description
Adequate Numerical Solution of Air Pollution Problems by positive Di#erence Schemes on
Ehrhardt, Matthias
Adequate Numerical Solution of Air Pollution Problems by positive Di#erence Schemes on unbounded In this work we deal with the numerical solution of some problems of air pollution. Since the problems) pollution. The e#ciency and accuracy of our method is illustrated by an example. Key words: air pollution
Adequate Numerical Solution of Air Pollution Problems by positive Difference Schemes on
Ehrhardt, Matthias
Adequate Numerical Solution of Air Pollution Problems by positive Difference Schemes on unbounded In this work we deal with the numerical solution of some problems of air pollution. Since the problems) pollution. The efficiency and accuracy of our method is illustrated by an example. Key words: air pollution
1. Department, Course Number, Title ORE 766 Numerical Methods in Ocean Engineering
Frandsen, Jannette B.
1. Department, Course Number, Title ORE 766 Numerical Methods in Ocean Engineering 2. Designation of numerical methods for simulating and solving ocean engineering problems. Topics include: Mathematical, & engineering Program Outcome 5: Use of latest tools in ocean engineering Program Outcome 6: Problem formulation
DIAGNOSIS OF INSULATED BUILDING WALLS USING PASSIVE INFRARED THERMOGRAPHY AND NUMERICAL SIMULATIONS
Paris-Sud XI, Université de
DIAGNOSIS OF INSULATED BUILDING WALLS USING PASSIVE INFRARED THERMOGRAPHY AND NUMERICAL SIMULATIONS This work presents the thermal monitoring of a multi-layered wall of a restored building (PANISSE platform parameters. Then they are compared with thermocouple measurements and numerical simulations. KEYWORDS
A New Book "NUMERICAL METHODS FOR LINEAR CONTROL SYSTEMS DESIGN AND ANALYSIS"
Datta, Biswa
A New Book "NUMERICAL METHODS FOR LINEAR CONTROL SYSTEMS DESIGN AND ANALYSIS" by Biswa Nath Datta I am pleased to announce publication of my book: "Numerical Methods for Linear Control Systems Design-of-the-art computationally viable algorithms for major tasks arising in linear control systems design and analysis
Clement, Prabhakar
Comparison of Numerical Techniques Used for Simulating Variable-Density Flow and Transport code by simulating two new variable-density-flow and transport experimental data sets. The experiments transport of a sinking groundwater plume and a rising groundwater plume. The numerical techniques used
Paris-Sud XI, Université de
- ever, they focus essentially on the pruning operation. In this paper, we present experimental evidences First-order numerical CSPs A numerical CSP (NCSP) is composed of variables whose domains are subsets by the compositional structure of the mixer: M = (A (E I S)) (V (C D True)). Formalisms derived from CSP have
Numerical Zoom for Multiscale Problems with an Application to Nuclear Waste Disposal
Numerical Zoom for Multiscale Problems with an Application to Nuclear Waste Disposal Jean of a nuclear waste repository site. Key words: Multiscale, Finite Element, Domain Decomposition, Chimera, Numerical Zoom, Nuclear Waste. PACS: 02.30.Jr, 47.11.Fg, 28.41.Kw, 47.55.P- 1 Introduction The present paper
On the Reliability of Numerical Solutions of Brine Transport in Groundwater: Analysis of In ltration
Bergamaschi, Luca
On the Reliability of Numerical Solutions of Brine Transport in Groundwater: Analysis of In#12, brine transport List of symbols c normalized salt concentration c k l value of concentration on triangle:37; p.2 #12; Reliability of Numerical Simulations of Brine Transport in Groundwater 3 equivalent
Numerical modeling of wave propagation in random anisotropic heterogeneous elastic media
Boyer, Edmond
Numerical modeling of wave propagation in random anisotropic heterogeneous elastic media Q.-A. Ta numerical experiments that were performed on wave propagation in a randomly generated anisotropic used for the propagation of waves in geophysical media are not compatible with the surface recordings
Walter, M.Todd
.53Â0.57 mm and the combustion gas is normal atmospheric pressure air. A detailed numerical simulationOn the spherically symmetrical combustion of methyl decanoate droplets and comparisons Biodiesel Biofuel Microgravity Numerical Droplet combustion a b s t r a c t This study presents
Chen, Qingyan "Yan"
. "Improvements on FFD modeling by using different numerical schemes," Numerical Heat Transfer, Part B (m) t time step (s) Greek Symbols ratio of mass flow rate to a flow domain over that out of the flow: Fundamentals, 58(1), 1-16. #12;2 Abstract Indoor environm ent design and air m anagement in buildings requires
A numerical framework for optimal control of switched affine systems with state
Paris-Sud XI, Université de
A numerical framework for optimal control of switched affine systems with state constraint Pierre optimal control, switched systems, complementarity systems, numerical method 1. INTRODUCTION Most of the results related to the optimal control of hybrid systems deal with subsystems sharing zero as common
Numerical Analysis of Non-constant Discounting with an Application to Renewable Resource Management
Karp, Larry S.
Numerical Analysis of Non-constant Discounting with an Application to Renewable Resource Management illustrate the approach by studying welfare and observational equivalence for a particular renewable resource man- agement problem. Keywords: Non-constant discounting, numerical methods, non-renewable resources
An efficient approach to the numerical solution of rate-independent problems with nonconvex energies
Bartels, Soeren
An efficient approach to the numerical solution of rate-independent problems with nonconvex energies S¨oren Bartelsa & Martin Kruz´ikb a Institut f¨ur Numerische Simulation, Rheinische Friedrich to the numerical treatment of non(quasi)convex rate-independent evolutionary problems. The main idea is to replace
Numerical tools applied to power reactor noise analysis Christophe Demazie`re*, Imre Pazsit
PÃ¡zsit, Imre
Review Numerical tools applied to power reactor noise analysis Christophe Demazie`re*, Imre Pa and application of the numerical tools employed. The code that was developed yields the space and non-critical systems with an external source. Some appli- cations of these tools to power reactor
Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent numerical simulations of multiphase (liquid-gas), multicomponent (H2OÂCO2) hydrothermal fluid flow
A Numerical quadrature for the Schwarz-Chimera J. -B. Apoung Kamga1
Pironneau, Olivier
A Numerical quadrature for the Schwarz-Chimera Method J. -B. Apoung Kamga1 and Olivier Pironneau2 1 Curie Olivier.Pironneau@upmc.fr Abstract Chimera [10] happens to be a version of Schwarz' method fvih, (8) #12;A Numerical quadrature for the Schwarz-Chimera Method 3 Theorem 2. (see Hecht et al. [4
NUMERICAL SIMULATION OF POOL BOILING FOR STEADY STATE AND TRANSIENT HEATING
Maruyama, Shigeo
1 NUMERICAL SIMULATION OF POOL BOILING FOR STEADY STATE AND TRANSIENT HEATING Ying He, Masahiro role in nucleate and transition boiling heat transfer at high heat flux. Many experiments have been in the numerical simulation of boiling heat transfer. In this study, based on the macrolayer evaporation model
Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and
Sites, James R.
Thesis Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and Explanation our supervision by Markus Gloeckler entitled "Numerical Modeling of CIGS Solar Cells: Definition. A three-layer structure, simulating a Cu(InGa)Se2 (CIGS) heterojunction solar cell, was set up using
NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE
Sites, James R.
NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE M. Gloeckler, A important complications that are often found in experimental CIGS and CdTe solar cells. 1. INTRODUCTION Numerical modeling of polycrystalline thin-film solar cells is an important strategy to test the viability
Numerical Study of Hypersonic Rarefied-Gas Flows About a Toroidal Ballute
Riabov, Vladimir V.
, pressure distribution, and drag have been found. Keywords: Torus, Balloon Parachute, Transition Rarefied-GasNumerical Study of Hypersonic Rarefied-Gas Flows About a Toroidal Ballute Vladimir V. Riabov investigated numerically using the Direct Simulation Monte-Carlo technique under transition rarefied-gas flow
Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters
Lee, Zhongping
Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters in the upper ocean, the vertical distribution of solar radiation (ESR) in the shortwave domain plays (2005), Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal
USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS,
Paris-Sud XI, UniversitÃ© de
USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS to develop a methodology to generate solar radiation maps using information from different sources. First with conclusions and next works in the last section. Keywords: Solar Radiation maps, Numerical Weather Predictions
A Flux-Limited Numerical Method for the MHD Equations to Simulate Propulsive Plasma Flows
Choueiri, Edgar
to be effective tools in plasma propulsion research, a higher order accu- rate solver that captures MHD shocks approach, numerical simulations are valuable tools in plasma thruster research. More- over, simulations can Simula- tions The importance of numerical simulation in advancing plasma thruster research was realized
The VOLNA code for the numerical modelling of tsunami waves: generation, propagation and
of the finite volume scheme implemented in the code. We explain the numerical treatment of the wet is decided on the base of inundation maps which are produced with this type of numerical tools. Finally we and the perspectives for future research presented. Key words: tsunami waves, shallow water equations, tsunami
Numerical evaluation of one-loop diagrams near exceptional momentum configurations
Walter T Giele; Giulia Zanderighi; E.W.N. Glover
2004-07-06T23:59:59.000Z
One problem which plagues the numerical evaluation of one-loop Feynman diagrams using recursive integration by part relations is a numerical instability near exceptional momentum configurations. In this contribution we will discuss a generic solution to this problem. As an example we consider the case of forward light-by-light scattering.
Energy and enstrophy transfer in numerical simulations of two-dimensional' turbulence
Vallis, Geoff
Energy and enstrophy transfer in numerical simulations of two-dimensional' turbulence Mathew E a significant fraction of the flow field,w and energy spectra from these simulations have slopes significantly October 1992; accepted 25 March 1993) Numerical simulations of statistically steady two-dimensional (2-D
Higham, Nicholas J.
423A HIGH-PERFORMANCE COMPUTING/NUMERICAL The International Journal of High Performance Computing and barriers in the development of high-performance computing (HPC) algorithms and software. The activity has computing, numerical analy- sis, roadmap, applications and algorithms, software 1 The High-performance
Numerical analysis of a one-dimensional elastodynamic model of dry friction and unilateral contact
Renard, Yves - Pôle de Mathématiques, Institut National des Sciences Appliquées de Lyon
.e. hyperbolic) model with dry friction. Since we consider a Coulomb friction law with a slip velocity dependentNumerical analysis of a one-dimensional elastodynamic model of dry friction and unilateral contact in the numerical analysis of more elaborated dynamic purely elastic problems with dry friction. Ó 2001 Elsevier
Numerical Investigation of a Transverse Jet in a Supersonic Crossflow using Large Eddy Simulation
Paris-Sud XI, Université de
Numerical Investigation of a Transverse Jet in a Supersonic Crossflow using Large Eddy Simulation injected fuel jets in hot supersonic crossflows. This paper describes the numerical algorithm being used into a supersonic crossflow computed on a coarse mesh. These results are discussed and similarity
An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling
Williamson, Mark
An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling Mark Williamson Working Paper 83 #12;An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling Mark for long time period simulations and large ensemble studies in Earth system models of intermediate
Ismagilov, Rustem F.
Effects of Shear Rate on Propagation of Blood Clotting Determined Using Microfluidics and Numerical-ismagilov@uchicago.edu Abstract: This paper describes microfluidic experiments with human blood plasma and numerical simulations removed. In addition, these results demonstrate the utility of simplified mechanisms and microfluidics
Numerical analysis of a model for Nickel-Iron alloy electrodeposition on rotating disk
Paris-Sud XI, Université de
Numerical analysis of a model for Nickel-Iron alloy electrodeposition on rotating disk electrode N the nickel-iron electrodeposition process, we have developed one-dimensional numerical model. This model ad can predict characteristic features of the nickel-iron sys- tem. this work was supported
Separation phenomena in the tritium source and numerical simulations of turbo-molecular pumps
Sharipov, Felix
Separation phenomena in the tritium source and numerical simulations of turbo-molecular pumps Felix In the previous works [1, 2], the results of numerical calculations of tritium flow from the buffer vessel up to the first vacuum system were reported. Two values of the tritium source temperature were considered, i.e. 27
Numerical assessment of stability criteria from disturbance energies in gaseous combustion
Nicoud, Franck
Numerical assessment of stability criteria from disturbance energies in gaseous combustion A, which corresponds to a ducted, laminar premixed propane-air flame, is used to assess the different terms a contribution from the unsteady heat flux-pressure correlation, allows a better agreement with the numerical
ON ACCURACY OF NUMERICAL EMC/EMI MODELING OVER A WIDE FREQUENCY RANGE
Loyka, Sergey
1 ON ACCURACY OF NUMERICAL EMC/EMI MODELING OVER A WIDE FREQUENCY RANGE Sergey Loyka EMC Lab: loyka@nemc.belpak.minsk.by Abstract - Numerical EMC/EMI modeling over a wide frequency range requires computational efficiency is proposed. I. INTRODUCTION Almost all the EMC problems are wide frequency range ones
OBJECT ORIENTED PROGRAMMING TECHNIQUES AND FAC METHOD IN NUMERICAL RESERVOIR SIMULATION \\Lambda
OBJECT ORIENTED PROGRAMMING TECHNIQUES AND FAC METHOD IN NUMERICAL RESERVOIR SIMULATION \\Lambda in numerical simulation of flow through hydrocarbon reservoirs within limitations in computing time and memory. These consist of solution of the conservation equations whichs govern the motion of fluid through the reservoir
Compact description of substrate-related aberrations in high numerical-aperture optical
Stallinga, Sjoerd
) and advanced optical disk4 (AOD) make use of GaN lasers with wavelength 0.405 m, with BD using a numericalCompact description of substrate-related aberrations in high numerical-aperture optical disk) through the substrate. Deviations of the thickness from the nominal value result in spherical aberration
Numerical study on optimal Stirling engine regenerator matrix designs taking into account matrix design that improves the efficiency of a Stirling engine has been developed in a numerical study of the existing SM5 Stirling engine. A new, detailed, one-dimensional Stirling engine model that delivers results
AI-Based Simulation: An Alternative to Numerical Simulation and Modeling
Mohaghegh, Shahab
: Numerical Modeling, Simulation, Artificial Intelligence, Data Min- ing, Reservoir Modeling, Reservoir data for brown fields. The run-time of AI-Based reservoir models that provide complete field responses Computational Fluid Dynamics (CFD) to Numer- ical Reservoir Simulation (NRS) most of the computational modeling
Corigliano, Alberto
Experimental characterization and numerical simulations of a syntactic-foam/glass-Â®bre composite core. Such core consists of a syntactic foam made by hollow glass microspheres embedded in an epoxy. Keywords: A. Glass Â®bre; Composite sandwich; Syntactic foam; Mechanical tests; Numerical simulations (FE) 1
A Numerical Study of Methods for Moist Atmospheric Flows: Compressible Equations
Duarte, Max; Balakrishnan, Kaushik; Bell, John B; Romps, David M
2013-01-01T23:59:59.000Z
We investigate different numerical techniques for evolving moist atmospheric flows within a fully compressible framework. In the standard numerical approach, the choice of variables is motivated by those that remain invariant in dry adiabatic flow, phase transitions are treated as an external energy source, and the physically-irrelevant fast acoustic modes are decoupled during the numerical integration. For the purposes of this study, we consider the compressible Euler equations in terms of the primitive thermodynamic variables, namely density, momentum, and total energy of moist air, without any special numerical treatment of the fast acoustic dynamics. This allows us to incorporate consistent moist thermodynamic properties throughout the numerical solution, and to thoroughly investigate both the standard two-step splitting approach for moist atmospheric flows as well as a fully coupled technique based on the use of variables that are conserved in moist flows, i.e. total energy of moist air and total water c...
Intermittent upwelling of asthenosphere beneath the Gregory Rift, Kenya
Tatsumi, Yoshiyuki (Univ. of Tasmania (Australia) Kyoto Univ. (Japan)); Kimura, Nobukazu (Kyoto Univ. (Japan)); Itaya, Tetsumaru (Okayama Univ. of Science (Japan)); Koyaguchi, Takehiro (Kumamoto Univ. (Japan)); Suwa, Kanenori (Nagoya Univ. (Japan))
1991-06-01T23:59:59.000Z
K-Ar dates and chemical compositions of basalts in the Gregory Rift, Kenya, demonstrate marked secular variation of lava chemistry. Two magmatic cycles characterized by incompatible element relative depletion are recognized; both occurring immediately after the peak of basaltic volcanism and coeval with both trachyte/phonolite volcanism and domal uplift of the region. These cycles may be attributed to increasing degree of partial melting of mantle source material in association with thinning of the lithosphere by thermal erosion through contact with hot upwelling asthenospheric mantle. Cyclic variation in asthenosphere upwelling may be considered an important controlling process in the evolution of the Gregory Rift.
Georgios Doulis; Oliver Rinne
2014-11-28T23:59:59.000Z
We describe a numerical method to construct Cauchy data extending to space-like infinity based on Corvino's (2000) gluing method. Adopting the setting of Giulini and Holzegel (2005), we restrict ourselves here to vacuum axisymmetric spacetimes and glue a Schwarzschildean end to Brill-Lindquist data describing two non-rotating black holes. Our numerical implementation is based on pseudo-spectral methods, and we carry out extensive convergence tests to check the validity of our numerical results. We also investigate the dependence of the total ADM mass on the details of the gluing construction.
Paris-Sud XI, Université de
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS Int. J. Numer. Anal and Analytical Methods in Geomechanics 29, 11 (2005) 1127-1155" DOI : 10.1002/nag.453 #12;1128 J.-M. PEREIRA ET
Apollo 15 yellow impact glasses: Chemistry, petrology, and exotic origin
Delano, J.W.; Lindsley, D.H.; Ma, M.; Schmitt, R.A.
1982-11-15T23:59:59.000Z
The Apollo 15 yellow impact glasses are characterized by moderate TiO/sub 2/ (approx.4.8%) and high abundances of the large ion lithophile elements (e.g., K, P, Hf, Th, REE). Since the chemistry of these glasses cannot be duplicated by any combination of local components presently known to occur at the Apollo 15 landing site, these yellow glasses seem to be exotic to that area. Chemical and petrologic constraints suggest that these samples were produced by impact melting of an immature mare regolith developed upon an unusual variety of mare basalt. We speculate that the target basalt were the youngest lava flows known to exist on the moon (i.e., Eratosphenian-age lavas in Oceanus Procellarum and Mare Imbrium). Specific tests are proposed for evaluating this provocative hypothesis.
Choueiri, Edgar
in plasma propulsion research, a high-order accurate solver that captures MHD shocks monotonically and works in plasma thruster research. Given the dearth of high-power test facilities, simulations can be valuable in these devices. 1.2. Existing work The importance of numerical simulations in advancing plasma thruster research
An Approach to 3D Magnetic Field Calculation Using Numerical and Differential Algebra Methods
Brady, V.
2011-01-01T23:59:59.000Z
number (n) the functions g. , g8, and g. are regarded asto derive from values of gr, g8, and g. at a single radius (numerical values of gr and g8 at a "central" location (zo)
Numerical Simulation of Enhanced Mixing in Scramjet Combustor Using Ramp, Tabs and Suction Collar
Hwang, Seung-Jae
2011-06-09T23:59:59.000Z
Numerical simulations of the scramjet combustor by using the commercial CFD code Fluent with the coupled implicit method with second-order accurate discretization have been obtained for the reacting flows with the parallel fuel injection (ramp...
Three-dimensional numerical manifold method simulations for blocky rock analysis
Shentu, Longfei
2011-01-01T23:59:59.000Z
After decades of development, people realize that there are wider and more various applications of numerical modeling and analysis. However, current feasible software tools cannot satisfy engineering and commercial goals. ...
Numerical methods for electromagnetic wave propagation and scattering in complex media
Moss, Christopher D. Q. (Christopher Doniert Q.), 1973-
2004-01-01T23:59:59.000Z
Numerical methods are developed to study various applications in electromagnetic wave propagation and scattering. Analytical methods are used where possible to enhance the efficiency, accuracy, and applicability of the ...
A numerical analysis of condenser performance of a seawater desalination system
Mohamed, Hassan, S.B. Massachusetts Institute of Technology
2009-01-01T23:59:59.000Z
This thesis presents the numerical analysis of three type condensers for desalination of seawater system. The condensers that were analyzed were a finned tube condenser that was built in Malaysia desalination plant, a ...
Numerical simulations of ion transport membrane oxy-fuel reactors for CO? capture applications
Hong, Jongsup
2013-01-01T23:59:59.000Z
Numerical simulations were performed to investigate the key features of oxygen permeation and hydrocarbon conversion in ion transport membrane (ITM) reactors. ITM reactors have been suggested as a novel technology to enable ...
RodrÃguez, Rodolfo
Numerical solution of transient eddy current problems with input current intensities as boundary to solve transient eddy current problems with input current intensities as data, formulated in terms: Eddy current problems, time-dependent electromagnetic problems, input current intensities, finite
MATHEMATICAL AND NUMERICAL ANALYSIS OF A TRANSIENT EDDY CURRENT PROBLEM ARISING FROM
RodrÃguez, Rodolfo
MATHEMATICAL AND NUMERICAL ANALYSIS OF A TRANSIENT EDDY CURRENT PROBLEM ARISING FROM transient axisymmetric eddy current problem governing such phenomenon. The resulting problem is degenerate. Electromagnetic forming, finite elements, eddy current, transient electromagnetics, degenerate parabolic problems
Analysis of Cold Air Distribution System in an Office Building by the Numerical Simulation Method
Jian, Y.; Li, D.; Xu, H.; Ma, X.
2006-01-01T23:59:59.000Z
Numerical simulation is carried out in this paper to calculate indoor air patterns, which include angles of inlet direction and induced ratios in a typical official room. According to the simulation results, the indoor air distribution and indoor...
Numerical modeling of elastic wave scattering by near-surface heterogeneities
Al Muhaidib, Abdulaziz
2013-01-01T23:59:59.000Z
A perturbation method for elastic waves and numerical forward modeling are used to calculate the effects of seismic wave scattering from arbitrary shape shallow subsurface heterogeneities. Wave propagation is simulated ...
Pham, Van Sang
We present a systematic, multiscale, fully detailed numerical modeling for dynamics of fluid flow and ion transport covering Ohmic, limiting, and overlimiting current regimes in conductance of ion-selective membrane. By ...
Numerical modeling of short pulse laser interaction with Au nanoparticle surrounded by water
Zhigilei, Leonid V.
Numerical modeling of short pulse laser interaction with Au nanoparticle surrounded by water Alexey, University of Virginia, USA Available online 3 February 2007 Abstract Short pulse laser interaction modeling; Nanoparticles; Cell targeting; Laser damage 1. Introduction Short pulse laser irradiation
A LOCAL DIMENSION TEST FOR NUMERICALLY APPROXIMATED POINTS ON ALGEBRAIC SETS
Sommese, Andrew J.
, denoted here as dimp(V ). This article presents a rigorous numerical local dimension test. The test (and computing the mult* *i- plicity if it is); 2.computing dimp(V ) for nonisolated
A LOCAL DIMENSION TEST FOR NUMERICALLY APPROXIMATED POINTS ON ALGEBRAIC SETS
Sommese, Andrew J.
, denoted here as dimp(V ). This article presents a rigorous numerical local dimension test. The test, which- plicity if it is); 2. computing dimp(V ) for nonisolated points p; 3. finding all irreducible components
A LOCAL DIMENSION TEST FOR NUMERICALLY APPROXIMATED POINTS ON ALGEBRAIC SETS
Sommese, Andrew J.
containing p, denoted here as dimp (V ). This article presents a rigorous numerical local dimension test the multiÂ plicity if it is); 2. computing dimp (V ) for nonisolated points p; 3. finding all irreducible
Analytical and numerical Gubser solutions of the second-order hydrodynamics
Long-Gang Pang; Yoshitaka Hatta; Xin-Nian Wang; Bo-Wen Xiao
2014-12-10T23:59:59.000Z
Evolution of quark-gluon plasma (QGP) near equilibrium can be described by the second-order relativistic viscous hydrodynamic equations. Consistent and analytically verifiable numerical solutions are critical for phenomenological studies of the collective behavior of QGP in high-energy heavy-ion collisions. A novel analytical solution based on the conformal Gubser flow which is a boost-invariant solution with transverse fluid velocity is presented. It is used to verify with high precision the numerical solution with a newly developed $(3+1)$-dimensional second-order viscous hydro code (CLVisc). The perfect agreement between the analytical and numerical solutions demonstrates the reliability of the numerical simulations with the second-order viscous corrections. This lays the foundation for future phenomenological studies that allow one to gain access to the second-order transport coefficients.
Numerical simulation of the impeller tip clearance effect on centrifugal compressor performance
Hoenninger, Corbett Reed
2001-01-01T23:59:59.000Z
This thesis presents the numerical simulation of flow in centrifugal compressors. A three-dimensional Navier-Stokes solver was employed to simulate flow through two centrifugal compressors. The first compressor simulated was the NASA low speed...
Z .Lithos 48 1999 153170 The evolution of continental roots in numerical thermo-chemical
Utrecht, Universiteit
Z .Lithos 48 1999 153170 The evolution of continental roots in numerical thermo-chemical mantle by a thick depleted root. q 1999 Elsevier Science B.V. All rights reserved. Keywords: Thermo
Tackley, Paul J.
TACKLEY ET AL.:THERMO-CHEMICAL PHILOSOPHY 1 Numerical and laboratory studies of mantle convection: Philosophy, accomplishments and thermo-chemical structure and evolution Paul J. Tackley Department of Earth
2D-Modelling of pellet injection in the poloidal plane: results of numerical tests
Paris-Sud XI, UniversitÃ© de
2D-Modelling of pellet injection in the poloidal plane: results of numerical tests P. Lalousis developed for computing the expansion of pellet-produced clouds in the poloidal plane. The expansion
Numerical and analytical studies of single and multiphase starting jets and plumes
Wang, Ruo-Qian
2014-01-01T23:59:59.000Z
Multiphase starting jets and plumes are widely observed in nature and engineering systems. An environmental engineering example is open-water disposal of sediments. The present study numerically simulates such starting ...
Course MA59800: Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale.
Santos, Juan
Course MA59800: Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale matrix properties, fine layering, frac- tures and craks at the mesoscale (on the order of centimeters
Course: Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale
Santos, Juan
Course: Numerical Simulation in Applied Geophysics. From the Mesoscale to the Macroscale Professor variations in the fluid and solid matrix properties, fine layering, frac- tures and craks at the mesoscale
An evaluation of pocket-model, numerical readout breath alcohol testing instruments
Van Tassel, William Edward
2004-11-15T23:59:59.000Z
Eight small-scale breath alcohol measurement devices were tested for accuracy, precision and the ability to not yield false positive and false negative readings. These pocket-sized breath testers (PMBTs), which provided numerical readout of Br...
Seamless Gluing of Numerical Continuation and a Multiple Solution Method for Elliptic PDEs
Kuehn, Christian
2014-01-01T23:59:59.000Z
Numerical continuation calculations for ordinary differential equations (ODEs) are, by now, an established tool for bifurcation analysis in dynamical systems theory as well as across almost all natural and engineering sciences. Although several excellent standard software packages are available for ODEs, there are - for good reasons - no standard numerical continuation toolboxes available for partial differential equations (PDEs), which cover a broad range of different classes of PDEs automatically. A natural approach to this problem is to look for efficient gluing computation approaches, with independent components developed by researchers in numerical analysis, dynamical systems, scientific computing and mathematical modelling. In this paper, we shall study several elliptic PDEs (Lane-Emden-Fowler, Lane-Emden-Fowler with microscopic force, Caginalp) via the numerical continuation software pde2path and develop a gluing component to determine a set of starting solutions for the continuation by exploting the v...