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Sample records for caradoc mixed siliciclastic-carbonate

  1. The nature of matrix in mixed siliciclastic-carbonate turbidites: An example from the Oquirrh-Wood River basin

    SciTech Connect

    Geslin, J.K. . Dept. of Earth and Space Sciences)

    1992-01-01

    Upper Pennsylvanian to Lower Permian strata of the Oquirrh-Wood River basin (OWRB) in southern Idaho are dominated by mixed siliciclastic-carbonate sediment gravity flows, including amalgamated sandy turbidites or grain flows, and silty turbidites. Previously, the petrology of the carbonate fraction of mixed siliciclastic-carbonate turbidites from the OWRB has been described as predominantly micrite. A source of micrite is present in phylloid algal mounds, which comprise a carbonate platform on the eastern basin margin. Visible micritized skeletal grains and fusulinids are uncommon in these sediments. It has been proposed that the micrite was subsequently neomorphosed to microspar or large, blocky spar. The actual volume of micrite in these deposits is enigmatic. Classic studies of turbidite hydrodynamics indicate that matrix accounts for no more than 20 percent, and commonly less, of the experimental turbidite deposits. Therefore, it is unlikely, based on hydrodynamics, that mixed siliciclastic-carbonate turbidites contain more than 20 percent micritic matrix. To resolve this enigma, multiple samples of the siliciclastic-carbonate turbidites from the OWRB were examined using a fluorescence (blue-light) microscope and the white-card technique. Under fluorescence the carbonate fraction of these samples was determined to contain micritized skeletal fragments; peloids, and micritized fusulinids. During diagenesis many of the carbonate grains were deformed and crushed to form carbonate pseudomatrix. Abundant carbonate grains indicate that mixed siliciclastic-carbonate turbidites from the OWRB adhere to established hydrodynamic principles, and contain less than 20 percent detrital matrix.

  2. Recognition of maximum flooding events in mixed siliciclastic-carbonate systems: Key to global chronostratigraphic correlation

    USGS Publications Warehouse

    Mancini, E.A.; Tew, B.H.

    1997-01-01

    The maximum flooding event within a depositional sequence is an important datum for correlation because it represents a virtually synchronous horizon. This event is typically recognized by a distinctive physical surface and/or a significant change in microfossil assemblages (relative fossil abundance peaks) in siliciclastic deposits from shoreline to continental slope environments in a passive margin setting. Recognition of maximum flooding events in mixed siliciclastic-carbonate sediments is more complicated because the entire section usually represents deposition in continental shelf environments with varying rates of biologic and carbonate productivity versus siliciclastic influx. Hence, this event cannot be consistently identified simply by relative fossil abundance peaks. Factors such as siliciclastic input, carbonate productivity, sediment accumulation rates, and paleoenvironmental conditions dramatically affect the relative abundances of microfossils. Failure to recognize these complications can lead to a sequence stratigraphic interpretation that substantially overestimates the number of depositional sequences of 1 to 10 m.y. duration.

  3. Mixing mechanisms in siliciclastic-carbonate successions of Khan Formation (Permian), Central Iran

    NASA Astrophysics Data System (ADS)

    Shadan, Mahdi; Hosseini-Barzi, Mahboubeh

    2010-05-01

    Mixing mechanisms in siliciclastic-carbonate successions of Khan Formation (Permian), Central Iran M. Shadan & M. Hosseini-Barzi Geology Department, Faculty of Earth Science, Shahid Beheshti University, Tehran, Iran shadangeo@gmail.com Mixing mechanisms in siliciclastic-carbonate successions of Khan Formation (Permian) have been studied in two sections (Chahroof with 197 m thick in north and Cheshmeh Bakhshi with 204 m thick in south) along basement Kalmard fault in Posht-e-Badam block, Central Iran. Siliciclastic units are characterized by well sorted, fine to medium grain quartzarenites with laterite interbeds, deposited in shoreline zone (foreshore, upper and lower shoreface) influencing wave and longshore currents. Longshore sands which have been transported along the coast made the sand bars in the shoreface. Further along the coast, returning of these currents as rip currents produced erosive channel inlets and caused to carry fine grain into the deeper regions of the basin. Based on this sedimentary model we introduced longshore currents as a probable agent for mixing, by transporting some volumes of sands into the adjacent carbonate environments. Vertically, clastic units of Khan Formation underlined by carbonate units of a tidal flat and high-energy inner ramp system. Repeating of this pattern produced 3 cycles in each section. Cyclic evolution, in studied sections, is accompanied with discrepancy in erosion and sedimentation. These factors caused to disperse local sub-aerial exposures in successions which are recognizable by laterite and conglomerate interbeds. These horizons of sub-aerial exposures are more often in Chahroof section than in Cheshmeh Bakhshi section and indicate more fluctuations of relative sea level probably due to more local tectonic activity in the northern part of the Kalmard fault than in the southern part of it. Also, thicker siliciclastic units in Chahroof section show higher rate of sediment supply and/or more accommodation space

  4. Stratigraphic framework of sediment-starved sand ridges on a mixed siliciclastic/carbonate inner shelf; west-central Florida

    USGS Publications Warehouse

    Edwards, J.H.; Harrison, S.E.; Locker, S.D.; Hine, A.C.; Twichell, D.C.

    2003-01-01

    Seismic reflection profiles and vibracores have revealed that an inner shelf, sand-ridge field has developed over the past few thousand years situated on an elevated, broad bedrock terrace. This terrace extends seaward of a major headland associated with the modern barrier-island coastline of west-central Florida. The overall geologic setting is a low-energy, sediment-starved, mixed siliciclastic/carbonate inner continental shelf supporting a thin sedimentary veneer. This veneer is arranged in a series of subparallel, shore-oblique, and to a minor extent, shore-parallel sand ridges. Seven major facies are present beneath the ridges, including a basal Neogene limestone gravel facies and a blue-green clay facies indicative of dominantly authigenic sedimentation. A major sequence boundary separates these older units from Holocene age, organic-rich mud facies (marsh), which grades upward into a muddy sand facies (lagoon or shallow open shelf/seagrass meadows). Cores reveal that the muddy shelf facies is either in sharp contact or grades upward into a shelly sand facies (ravinement or sudden termination of seagrass meadows). The shelly sand facies grades upward to a mixed siliciclastic/carbonate facies, which forms the sand ridges themselves. This mixed siliciclastic/carbonate facies differs from the sediment on the beach and shoreface, suggesting insignificant sediment exchange between the offshore ridges and the modern coastline. Additionally, the lack of early Holocene, pre-ridge facies in the troughs between the ridges suggests that the ridges themselves do not migrate laterally extensively. Radiocarbon dating has indicated that these sand ridges can form relatively quickly (???1.3 ka) on relatively low-energy inner shelves once open-marine conditions are available, and that frequent, high-energy, storm-dominated conditions are not necessarily required. We suggest that the two inner shelf depositional models presented (open-shelf vs. migrating barrier-island) may

  5. Facies analysis and sequence stratigraphy of the Cenomanian-Turonian mixed siliciclastic-carbonate sediments in west Sinai, Egypt

    NASA Astrophysics Data System (ADS)

    Anan, Tarek I.

    2014-06-01

    The unconformity bounded Cenomanian-Turonian succession in west Sinai is subdivided into three formations: the Raha, Abu Qada, and Wata. These rock units were deposited in a mixed siliciclastic-carbonate system on a ramp setting. The studied ramp only includes inner and mid-ramp facies, whereas the outer ramp facies occurs in northern Sinai. Four sequence boundaries (SB) were recognized in the studied formations due to the presence of subaerial exposure or flooding events in the facies stacking pattern. The first and last sequence boundaries (SB1 and SB4) might be considered as Type 1 sequence boundary attributable to the presence of widespread erosion. It is difficult to determine type of the second and third sequence boundaries (SB2 and SB3) because of their minor unconformity and minimal erosion. Determination of systems tracts within the Wata Formation is debatable owing to the action of dolomitization that has destroyed both original components and sedimentary structures. The lowstand systems tracts of the recorded sequences are characterized by sandstones, siltstones, and sandy shales, while fossiliferous shale and limestone with oysters prevailed during sea level rise. The highstand systems tracts are generally characterized by shallow intertidal and subtidal deposits that are made up of abundant oyster wackestones with benthic foraminifera and ostracods.

  6. Sequence boundaries in uppermost Proterozoic mixed siliciclastic-carbonate rocks: Deep Spring Formation, southern Basin and Range

    SciTech Connect

    Parsons, S.M.; Rees, M.N. . Geosciences Dept.)

    1993-04-01

    The authors propose that a sequence boundary lies at the top of the Reed Dolomite and another at the top of the lower member of the overlying Deep Spring Formation. These boundaries should be useful in correlating critical pre-trilobite Neoproterozoic rocks across the southern Basin and Range Province. Furthermore, the mixed siliciclastic-carbonate rocks between these boundaries reflect an intimate interplay between subsidences, sea-level change and the different rates at which siliciclastic and carbonate sediments accumulate. The Type 2 sequence boundary at the top of the Reed Dolomite is marked in outcrop near Bishop, California by minor channelization and dissolution surfaces that resulted from subaerial exposure of the carbonate platform. This sea level low stand is recorded in the lower Deep Spring Formation, 150 km northwest, by carbonate sediment-gravity-flow deposits. With initiation of transgression, siliciclastics buried the eroded platform and carbonate sedimentation continued in the northwest. As sea level continued to rise, carbonate deposition occurred across the region. Time of maximum flooding is represented by lagoonal deposits in the southeast and a condensed section to the northwest. The condensed section is characterized by dolomitized limestones containing glauconite and small shelly fossils that are overlain by thinly interbedded shales and siltstones with rare trace fossils. The slower rate of siliciclastic deposition on the rapidly subsiding shelf produced an increase in accommodation space resulting in development of an ooid shoal to the southeast. To the northwest, however, continued submarine deposition produced thinly interbedded limestone turbidities and shales. Ooid accumulation outpaced subsidence and together with sea level fall resulted in extensive subaerial exposure of the oolite. Thus, the top of the lower member of the Deep Spring Formation represents the second Type 2 sequence boundary.

  7. Late Oligocene-Early Miocene larger benthic foraminifera from the mixed siliciclastic-carbonate and reefal strata of Kharabeh Sanji stratigraphic section, NW Iran

    NASA Astrophysics Data System (ADS)

    Hosseinzadeh, R.

    2012-04-01

    The marine Oligo-Miocene sediments of the Qom Formation at Kharabeh Sanji section west Uromieh consisting of mixed siliciclastic-carbonates changing to reefal strata were studied in detail to establish a high resolution biostratigraphic zonal scheme. Contineous distribution of larger benthic foraminifera (mainly miogypsinids) allowed us to correlate the identified taxa with the shallow benthic zonation (SBZ) already introduced for European sequences and to ascribe detailed age to the study section based on the determined biozones. The identified fauna include the genera Miogypsinodes, Miogypsina, Neorotalia, Nephrolepidina, Eulepidina and Spiroclypeus. The foraminifereal assemblage resemble to the fauna described from European basins characterizing the SBZ 23 to SBZ 25 zones representing a time interval from the Late Chattian to Burdigalian.

  8. Carbonate cementation as related to the diagenesis of clay in a mixed siliciclastic-carbonate system: Examples from the Centerfield biostrome, east central Pennsylvania

    SciTech Connect

    Burns, C.D. )

    1994-03-01

    The Middle Devonian Mahantango Formation consists of siliciclastic and mixed carbonate-siliciclastic sediment packages that pulse in and out of the stratigraphy. The formation crops out in several places throughout the folded rocks of eastern Pennsylvania and Maryland. The Centerfield Member is one of the mixed siliciclastic-carbonate packages in the Mahantango Fm. This member crops out in east central Pennsylvania. The Centerfield Mbr. has been interpreted as a series of biostromes and contain abundant rugosan corals, crinoids, bryozoans, and brachiopods. The biostromes have undergone a complex diagenetic history. Illite, smectite, chlorite and muscovite have been found with the use of powder x-ray diffraction and petrographic analysis. The smectite and some of the illite are depositional clays, while, the remaining illite, chlorite and muscovite represent recrystallization of the depositional clays. There are six phases of cement in the biostrome. The paragenetic sequence of the cements is as follows: non-ferroan low magnesian calcite (LMC), intermediate ferroan LMC, ferroan LMC, non-ferroan dolomite, ferroan baroque dolomite, and quartz cement in the form of chert and blocky cement. Staining shows that the iron content of the cement changes within individual crystals and between cement phases. Preliminary data suggest that the cements may be directly related to the steady release of ions during the diagenesis of the surrounding clays in the shale.

  9. Depositional framework and sequence stratigraphic aspects of the Coniacian Santonian mixed siliciclastic/carbonate Matulla sediments in Nezzazat and Ekma blocks, Gulf of Suez, Egypt

    NASA Astrophysics Data System (ADS)

    El-Azabi, M. H.; El-Araby, A.

    2007-04-01

    Superb outcrops of mixed siliciclastic/carbonate rocks mark the Coniacian-Santonian Matulla Formation exposed in Nezzazat and Ekma blocks, west central Sinai. They are built up of various lithofacies that reflect minor fluctuations in relative sea-level from lower intertidal to slightly deep subtidal settings. Relying on the facies characteristics and stratal geometries, the siliciclastic rocks are divided into seven depositional facies, including beach foreshore laminated sands, upper shoreface cross-bedded sandstone, lower shoreface massive bioturbated and wave-rippled sandstones, shallow subtidal siltstone and deep subtidal shale/claystone. The carbonate rocks comprise lower intertidal lime-mudstone, floatstone and dolostone, shallow subtidal skeletal shoal of oyster rudstone/bioclastic grainstone, and shoal margin packstone. Oolitic grain-ironstone and ferribands are partially intervened the facies types. Deposition has taken place under varied conditions of restricted, partly open marine circulation, low to high wave energy and normal to raised salinity during alternating periods of abundant and ceased clastic supply. The facies types are arranged into asymmetric upward-shallowing cycles that record multiple small-scale transgressive-regressive events. Lime-mudstone and sandstone normally terminate the regressive events. Four sequence boundaries marking regional relative sea-level falls divide the Matulla Formation into three stratigraphic units. These boundaries are Turonian/Coniacian, intra-Coniacian, Coniacian/Santonian and Santonian/Campanian. They do not fit with those sequence boundaries proposed in Haq et al.'s global eustatic curves (1988) except for the sea-level fall associated with the intra-Coniacian boundary. Other sequence boundaries have resulted from regional tectonic impact of the Syrian Arc Fold System that has been initiated in north Egypt during the Latest Turonian-Coniacian. These boundaries enclose three well-defined 3rd order

  10. Brunhes Evolution of the Belize Mixed Siliciclastic Carbonate Margin: Source to Sink Dynamics Relative to Glacial-Interglacial Sea Level Fluctuations

    NASA Astrophysics Data System (ADS)

    Olson, B. E.; Droxler, A. W.; Dickens, G.; Beaufort, L.

    2004-12-01

    Mixed siliciclastic carbonate systems are developed on continental margins where significant volumes of terrigenous sand and mud interact with shallow water tropical carbonate barrier reefs and banks. These systems represent highly dynamic environments, directly influenced by sea level fluctuations and climatic changes. In current sequence stratigraphy models, neritic carbonates flourish, exporting sediments to the basins during sea level highstands, while siliciclastic input to the basins is maximum during lowstands. In contrast, this study demonstrates that siliciclastic and carbonate sedimentation is not in phase with late Quaternary glacial-interglacial lowstand/highstand cycles on the central Belize margin. This study is based on the analyses of a well-dated continuous 37.7 m long piston core, MD02 2532, collected 3 km offshore the central Belize Barrier reef in the distal slope of Gladden Basin at 333 m of water depth by the R/V Marion Dufresne (IPEV). A robust chronology is established using high resolution planktic oxygen isotope stratigraphy, anchored by several nannofossil stratigraphic and tephrochronologic markers, as well as radiocarbon ages in the upper part of the core, and demonstrates that the core represents most of the Brunhes (about 0.7 My). The upper 26m of MD02 2532 penetrated five subunits of the distal portion of a sedimentary wedge, likely corresponding to interglacial intervals from Marine Isotope Stage (MIS) 11 to MIS 1 (Holocene), while the lower 11.7m recovered the upper portion of an underling subparrallel reflector seismic unit. Bulk carbonate percent values cyclically vary down the core; low values of 40 to 50% typically occur during the interglacial to glacial transitions, whereas high values of 70 to 80% typically occur at the glacial to interglacial transitions. The Holocene interval is characterized by the highest values observed in the entire core, reaching 82-83%. Calculated siliciclastic fluxes to the slope are greatest during

  11. Total assemblages of benthic foraminifera from a mixed siliciclastic/carbonate inner shelf; preliminary results from the bays of Soline and Nin (Adriatic Sea, Croatia)

    NASA Astrophysics Data System (ADS)

    Vidović, J.; Ćosović, V.; Juračić, M.; Benac, Č.

    2012-04-01

    Eastern Adriatic shelf is mixed siliciclastic/carbonate area with a great proportion of carbonate biogenous production. This study presents analysis and comparison of total benthic foraminiferal assemblages (their composition, diversity and distribution) in surface sediments from two Eastern Adriatic shallow water bays (Soline and Nin Bay), sampled seasonally from 2006 to 2008. In order to characterize the carbonate sediment production, 62 samples along the bathymetric profiles (from 2 to 20 m) were collected by scuba diving with short PVC corers. Granulometrical analysis was done using method of wet sieving. Statistical analyses (cluster analysis, PCA) were performed using Past program. The most abundant biogenous components in different sediments from Soline Bay (muddy sandy gravel and mud) are foraminifera, followed by fragments of mollusks, gastropods, bryozoans and sea urchins. Foraminiferal assemblages are high diversified as confirmed by Shannon-Wiener index varying from 2.14 to 3.39, Fisher α index from 5.74 to 16.30 and Equitability from 0.32 to 0.72. The shallowest part of the bay is covered with the sand, consisted of high proportion of siliciclastic component and impoverished in biogenous remnants. Foraminiferal assemblages have low diversity (Shannon-Wiener index 1.36, Fisher α index 2.31 and Equitability 0.32). Throughout Nin Bay, sediments (classified as sand, muddy sand and mud) are consisted of various biogenic remnants. Foraminiferal assemblages have high biodiversity, with Shannon-Wiener index varying from 2.51 to 3.20, α-Fisher index from 7.84 to 12.64 and Equitability from 0.37 to 0.77. Statistical analyses (cluster analysis and PCA) grouped foraminifera in two major assemblages, related to sediment type. On sandy and gravely substrates, assemblage is dominated by epifaunal genera and species: Quinqueloculina sp. (6-20%), Elphidium sp. (5-16%), Neoconorbina terquemi (6-10 %) and Asterigerinata mamilla (5-7%). Infaunal species, Ammonia

  12. Preliminary results in larger benthic foraminifera assemblage in a mixed siliciclastic-carbonate platform from the Upper Cretaceous of the External Prebetic Domain (Valencia province, SE Spain)

    NASA Astrophysics Data System (ADS)

    Robles-Salcedo, Raquel; Vicedo, Vicent

    2016-04-01

    In the External Prebetic Domain (Betic Mountain Range, Valencia province, SE Spain) it is difficult to find good outcrops to study larger benthic foraminifera (LBF), particularly in the Upper Cretaceous deposits, because of three main reasons. During the Upper Cretaceous, the complex paleogeography in the northern Prebetic Domain developed a complex system of shallow-water platforms. This is directly linked to the complexity in the distribution of the facies observed nowadays, which may change drastically in lateral, closely related outcrops having a special negative impact in the lateral extension of stratigraphical levels containing LBF. The second reason is the nature of the shallow water environments in which the larger foraminifera lived. The local continental influence derived in the establishment of very complex mixed platforms. Thus, there is not a complete register through carbonate rocks, but an alternation of microconglomerates, sandstones, calcarenites and carbonates that can be observed in the stratigraphic series of the Upper Cretaceous. This affects negatively in observing changes in the evolutionary trends of taxa. The third reason difficulting the study of LBF in northern localities of the Prebetic Domain is diagenetic. Dolomitization affects a huge part of the Mesozoic rocks deleting all fossil microfauna in the affected rocks. Such three reasons are behind the difficulty in developing correlations and having a comprehensive understanding of the biostratigraphy and phylogeny of the taxa involved. However, after several field trips developed in the northern Prebetic area, an excellent reference section for the study of the LBF in the Prebetic Domain has been identified in the surroundings of the Pinet village (Valencia province). Here, a relatively continuous section with scarce dolomitization and good conditions of accessibility exists. The larger foraminifera assemblages appering in the Pinet section will be compared with other paleobiogeographic

  13. Trace element signature of Late Jurassic siliciclastic-carbonate sedimentary strata from western Montana, southeastern British Columbia and southern Alberta

    SciTech Connect

    Sablock, J. . Dept. of Geosciences)

    1992-01-01

    A trace element signature, a characteristic pattern of enrichment and depletion of trace elements, was determined for a group of siliciclastic-carbonate Oxfordian and Kimmeridgian sedimentary strata, collected from outcrops in western Montana, southeastern British Columbia and southern Alberta. The average values, by petrofacies, of 10 major and 18 trace elements were measured for 40 samples. These data were normalized to Upper Continental Crust (UCC), and plotted against averaged published values of graywackes from the same facies. The rare earth elements (REEs), as well as Ti, Zr, Nb and Y are considered immobile even through diagenesis, and at least low level metamorphism. So these elements should form a reliable part of the geochemical signature. Compared to UCC and average graywacke, Jurassic samples are very depleted in Zr, Nb and Y. Oxfordian samples have slightly higher rare earth element values, i.e. La, Ce and Nd, than either other Jurassic samples or average graywacke. The most likely source of REE values are garnets and tourmaline which occur as inclusions in monocrystalline quartz grains. This pattern, and petrological study, point to a sedimentary source area, deficient in feldspar, heavy minerals and rock fragments. The consistency of the signature throughout this time may indicate slow uplift of a widespread sedimentary source area, or could be an effect of greater mixing and shorter residence time of dissolved materials in an epeiric sea.

  14. Evolution of the siliciclastic-carbonate shelf system of the northern Kenyan coastal belt in response to Late Pleistocene-Holocene relative sea level changes

    NASA Astrophysics Data System (ADS)

    Accordi, Giovanni; Carbone, Federico

    2016-11-01

    A classification of depositional environments of the Lamu Archipelago is proposed based on a sedimentary facies analysis of unconsolidated and hard bottoms of the study area. The genesis of the siliciclastic-carbonate depositional pattern, typical of this East African region, is closely related both to the presence of a quartz-dominate Pleistocene riverine net-flooded during the Holocene sea level rise-and to the coeval development on the shallow shelf of a coral ecosystem producing vast skeletal sediments. The present facies pattern originates from the variable contribution in time and space of three sediment types: skeletal carbonate, quartz and palimpsest debris. The facies analysis allowed to distinguish 10 depositional facies and to differentiate them into three main types of substratum: soft bottom, reefal hard bottom and non-reefal hard bottom. These three types define both the loose facies typical of the channelized coastal belt and several facies of the shallow shelf. In the first, the amounts and textures of the stored sediment are strictly related to three major geomorphic types of substratum: sheltered mangal flat, shallow channel and deep channel. In the second and the third, a wide range of textures is related to coastal flats, benches, islets and emerging rocks. This modern facies pattern is implemented through a series of evolutionary phases: i-during the Last Interglacial Period, since isotope substage 5b, the shallow shelf-above -20 m-is permanently exposed for about 80 ka, with erosion, karstification and cuts of river channels through the shelf; ii-after the Last Glacial Maximum, when the sea level fell to about 110-115 m b.p.s.l. (below present sea level) at 18-17 ka BP, the sea level rose at -20 m for about 9 ka, flooding the shallow shelf area and gradually drowning the riverine net; iii-the maximum flooding of the coastal belt was reached at about 4.5 ka BP, when a gradual moisture reduction caused a decrease of siliciclastic sediment supply

  15. Holocene siliciclastic-carbonate facies mosaics, Northern Belize: Exploration analog to some midcontinent Pennsylvanian (Morrowan) reservoirs

    SciTech Connect

    Lowe, D.B.; Mazzullo, S.J.

    1995-09-01

    Midwinter Lagoon is a large, shallow coastal lagoon, bordered on its seaward side by a barrier, along the mainland coast of northern Belize. As much as 19 ft of Holocene sediments, deposited on karsted Tertiary limestones during the Flandrian transgression, consist of a complex mosaic of mixed siliciclastic and carbonate facies. Basal transgressive marine, intra-lagoonal facies are variously siliciclastic-rich carbonates to carbonate-rich siliciclastics, locally with layers of shoreline mangrove peat. These facies shallow-upward to either siliciclastic or carbonate-dominated sands or muds. Lagoonal facies were deposited within a broad topographic low, locally punctuated by bedrock highs, on the underlying limestone. The seaward edge of the barrier bar complex, which was deposited on a linear topographic high, consists mostly of quartz sands, whereas the lagoonal side is a mixture of quartzose and carbonate sediments (sands and muds). The barrier bar appears to have accreted southward in response to southerly longshore drift as a tidal inlet-spit complex; quartz sands are being transported into the lagoon from its seaward side. In terms of geometry, modern and buried, intra-lagoonal carbonate sands occur as lobes deposited proximal to extant and older tidal inlets. Either carbonate or siliciclastic sands variously occur as erratically distributed, anastomosing beach deposits around small mangrove islands and along the irregular mainland coast. In contrast, siliciclastic sands on the seaward side of the barrier define a narrow but areally persistent linear trend. Similar complex facies associations and geometries are typical of many Pennsylvanian (Morrowan) reservoirs in the midcontinent US.

  16. Tectonic and eustatic control on a mixed siliciclastic-carbonate platform during the Late Oxfordian-Kimmeridgian (La Rochelle platform, western France)

    NASA Astrophysics Data System (ADS)

    Carcel, Damien; Colombié, Claude; Giraud, Fabienne; Courtinat, Bernard

    2010-01-01

    Boreal and Tethyan realms of Western Europe present significant sedimentological, paleontological, and stratigraphic differences. The purpose of this study is to constrain regional versus global controls on the dynamics of a sedimentary system located at the interface of these two realms in order to better understand the origin of their differences. Detailed sedimentological, palynofacies and calcareous nannofossil analyses were performed on two sections from the La Rochelle platform (western France). The Pas section includes part of the Late Oxfordian and Early Kimmeridgian, and the Rocher d'Yves section is assigned to the Late Kimmeridgian. They correspond to monotonous marl-argillaceous limestone alternations. Limestones are essentially mudstones with echinoderms, bivalves and foraminifera that suggest low-energy, open-marine conditions. Highly bioclastic and/or peloidal deposits occur commonly, and show wackestones to wacke-pack-grainstones textures. These deposits indicate frequent high-energy events, and are interpreted as storm deposits. Marls dominate in the most proximal depositional environments, while calcareous deposits are more important in more distal environments. The Rocher d'Yves section is globally more marly than the Pas section, suggesting a more proximal setting. Palynofacies are dominated by woody particles, suggesting shallow-water, proximal depositional environments. Calcareous nannofossils are ascidian spicules, coccoliths, and schizospheres. Watznaueria britannica dominate calcareous nannofossil assemblages in the Pas section. The Rocher d'Yves assemblages are quasi-exclusively composed of Cyclagelosphaera margerelii, and indicate more proximal paleoenvironments than those of the Pas section. Different orders of depositional sequences are defined, with sequence boundaries corresponding to the most rapid relative sea-level falls. They are hierarchically stacked, and correlate, on the basis of ammonite zones, with the sequences of contemporaneous sections from Tethyan and boreal realms. The stacking pattern of these sequences suggests an orbital control on sedimentation. Small-, medium- and large-scale sequences correspond to precession (20 ky) cycles and to 100 ky and 400 ky eccentricity cycles, respectively. The elementary sequences have durations shorter than 20 ky. The Kimmeridgian was a period of global sea-level rise that ended in the Late Kimmeridgian. More proximal depositional environments in the Rocher d'Yves section (Late Kimmeridgian) than in the Pas section (Early Kimmeridgian) imply a progradation of the La Rochelle platform during the Kimmeridgian. This progradation resulted from a slowdown of the subsidence in the Aquitaine Basin during the Kimmeridgian, corresponding to the first steps of Atlantic Ocean opening. High-frequency cycles on the La Rochelle platform formed in sync with Milankovitch orbital cycles, while tectonics controlled the formation of the low-frequency cycles.

  17. Deglacial origin of barrier reefs along low-latitude mixed siliciclastic and carbonate continental shelf edges.

    PubMed

    Droxler, André W; Jorry, Stéphan J

    2013-01-01

    Because the initial phase of barrier reef evolution is often buried under more recent phases of coralgal growth, the origins of modern barrier reefs have remained elusive. Direct observations on the nature of the substrate on top of which barrier reefs have developed are lacking, and simple questions about whether the substrate contributes to their overall linear morphology have remained unanswered. We present here a review dedicated to late-Quaternary shelf-edge deposition in tropical mixed siliciclastic-carbonate systems. These modern analogs are used to develop a quantitative understanding of shelf-edge barrier reef formation during different segments of relatively well-established sea-level cycles. The onset of rapid sea-level rise during early deglaciations, when siliciclastics were deposited along newly formed coasts at up-dip positions, provided opportune time windows for coralgal communities to establish themselves on top of maximum lowstand siliciclastic coastal deposits, such as beach ridges and lowstand shelf-edge deltas.

  18. Integrated workflow for characterizing and modeling a mixed sedimentary system: The Ilerdian Alveolina Limestone Formation (Graus-Tremp Basin, Spain)

    NASA Astrophysics Data System (ADS)

    Hamon, Youri; Deschamps, Remy; Joseph, Philippe; Doligez, Brigitte; Schmitz, Julien; Lerat, Olivier

    2016-09-01

    This paper proposes an advanced stochastic workflow to jointly model sedimentary facies and diagenesis. The formation of interest is the Early Eocene Alveolina Limestone Formation, which outcrops in the Serraduy area (Graus-Tremp Basin, NE Spain). Ten sedimentary lithotypes representing facies or facies associations of a mixed siliciclastic-carbonate ramp system were identified within the succession. A 3D model describing the depositional architecture is also proposed. The results from the diagenetic study evidenced the occurrence of several successive calcite cements, which were grouped into five diagenetic imprints for modeling. These imprints were then quantified to ease their integration into numerical models. The following step consisted in building a 3D gridded model with seven different modeling units. They were populated using a bi-plurigaussian simulation approach that reproduced both the sedimentary organization and the observed diagenetic imprint distributions. Last, the simulation results were validated referring to paleogeographic and diagenetic conceptual maps.

  19. Modern cool-water siliciclastic/carbonate sediments, lacepede shelf South Australia

    SciTech Connect

    Bone, Y.; Gostin, V. ); James, N.P. ); Von der Borch, C.C. )

    1991-03-01

    The Lacepeded Shelf is a 130 km {times} 100 km open embayment along the southern passive continental margin of Australia. The shelf includes the mouth of the River Murray - Australia's largest drainage system- the extensive arcuate Coorong strand, the 50-70 m deep and flat plateau of the shelf proper, the nonrimmed shelf break, and the upper slope to depths of 200 m. The shelf bathymetry is locally interrupted by seafloor highs, reflecting the underlying rugged terrain of deformed Precambrian and early Paleozoic bedrock in the west and Tertiary limestones and Quaternary dunes in the east. The late Pleistocene/Holocene sediment blanket is formed by discrete sedimentary facies. Quartz sands cover a significant cross-shelf zone opposite the river mouth, with current generated offsets. High-resolution seismic profiles reveal buried lowstand channels. The mid-shelf is an area of conspicuously coarse-grained, mud-free loose sediments composed of variable amounts of bryozoans and bivalves. The shelf break and upper slop bryozoan sands are similar, apart from species differences, from 40 to 100 m, with an increase in mud below 100 m. The seafloor highs are sites of prolific bryozoan, calcareous algae, sponge, and bivalve growth, the skeletons of which are shed onto the shelf. Bryozoan distribution is moderated by water depth and substrate type. Most forms are low-Mg calcite to high-Mg calcite, but two major groups are aragonitic. Distribution of these different mineralogical types is important for later diagenesis. Both terrigenous clastic and carbonate sediments are a mixture of relict and modern components, depending upon location, and reflect Holocene glacio-eustatic sea-level changes.

  20. Sediment-starved sand ridges on a mixed carbonate/siliciclastic inner shelf off west-central Florida

    USGS Publications Warehouse

    Harrison, S.E.; Locker, S.D.; Hine, A.C.; Edwards, J.H.; Naar, D.F.; Twichell, D.C.; Mallinson, D.J.

    2003-01-01

    currents. An elevated rock terrace extending from the headland supports these ridges in a shallower water environment than the surrounding shelf, allowing them to be more easily influenced by currents and surface gravity waves. Tidal currents, storm-generated flows, and seasonally developed flows are shore-parallel and oriented obliquely to the NW-SE trending ridges, indicating that they have developed as described by the Huthnance model. Although inner shelf sand ridges have been extensively examined elsewhere, this study is the first to describe them in a low-energy, sediment-starved, dominantly mixed siliciclastic/carbonate sedimentary environment situated on a former limestone platform. ?? 2003 Elsevier B.V. All rights reserved.

  1. Mixed Dementia

    MedlinePlus

    ... community Use our Virtual Library Treatment and outcomes back to top Because most people with mixed dementia are diagnosed with a single type of dementia, physicians often base their prescribing decisions on the type of dementia ...

  2. Ion mixing

    NASA Technical Reports Server (NTRS)

    Matteson, S.; Nicolet, M.-A.

    1983-01-01

    Recent experimental studies of the ion-mixing phenomenon are summarized. Ion mixing is differentiated from ion implantation and shown to be a useful technique for overcoming the sputter-dependent limitations of implantation processes. The fundamental physical principles of ion/solid interactions are explored. The basic experimental configurations currently in use are characterized: bilayered samples, multilayered samples, and samples with a thin marker layer. A table listing the binary systems (metal-semiconductor or metal-metal) which have been investigated using each configuration is presented. Results are discussed, and some sample data are plotted. The prospects for future application of ion mixing to the alteration of solid surface properties are considered. Practical applications are seen as restricted by economic considerations to the production of small, expensive components or to fields (such as the semiconductor industry) which already have facilities for ion implantation.

  3. Lateral Mixing

    DTIC Science & Technology

    2011-09-30

    ocean as it responds to mesoscale forcing. APPROACH Figure 1: MVP system deployed from stern of R/V Endeavor in Sargasso Sea . My approach for...therefore requires integrative efforts with other sea -going investigators and numerical modelers. The Lateral Mixing Experiment project was an ideal...also participated in the sea -going part of this project, taking my group on the R/V Endeavor in June 2011. Our role was to sample around the center of

  4. Mixed cryoglobulinemia

    PubMed Central

    Ferri, Clodoveo

    2008-01-01

    Mixed cryoglobulinemia (MC), type II and type III, refers to the presence of circulating cryoprecipitable immune complexes in the serum and manifests clinically by a classical triad of purpura, weakness and arthralgias. It is considered to be a rare disorder, but its true prevalence remains unknown. The disease is more common in Southern Europe than in Northern Europe or Northern America. The prevalence of 'essential' MC is reported as approximately 1:100,000 (with a female-to-male ratio 3:1), but this term is now used to refer to a minority of MC patients only. MC is characterized by variable organ involvement including skin lesions (orthostatic purpura, ulcers), chronic hepatitis, membranoproliferative glomerulonephritis, peripheral neuropathy, diffuse vasculitis, and, less frequently, interstitial lung involvement and endocrine disorders. Some patients may develop lymphatic and hepatic malignancies, usually as a late complication. MC may be associated with numerous infectious or immunological diseases. When isolated, MC may represent a distinct disease, the so-called 'essential' MC. The etiopathogenesis of MC is not completely understood. Hepatitis C virus (HCV) infection is suggested to play a causative role, with the contribution of genetic and/or environmental factors. Moreover, MC may be associated with other infectious agents or immunological disorders, such as human immunodeficiency virus (HIV) infection or primary Sjögren's syndrome. Diagnosis is based on clinical and laboratory findings. Circulating mixed cryoglobulins, low C4 levels and orthostatic skin purpura are the hallmarks of the disease. Leukocytoclastic vasculitis involving medium- and, more often, small-sized blood vessels is the typical pathological finding, easily detectable by means of skin biopsy of recent vasculitic lesions. Differential diagnoses include a wide range of systemic, infectious and neoplastic disorders, mainly autoimmune hepatitis, Sjögren's syndrome, polyarthritis, and B

  5. Mixed cryoglobulinemia.

    PubMed

    Ferri, Clodoveo

    2008-09-16

    Mixed cryoglobulinemia (MC), type II and type III, refers to the presence of circulating cryoprecipitable immune complexes in the serum and manifests clinically by a classical triad of purpura, weakness and arthralgias. It is considered to be a rare disorder, but its true prevalence remains unknown. The disease is more common in Southern Europe than in Northern Europe or Northern America. The prevalence of 'essential' MC is reported as approximately 1:100,000 (with a female-to-male ratio 3:1), but this term is now used to refer to a minority of MC patients only. MC is characterized by variable organ involvement including skin lesions (orthostatic purpura, ulcers), chronic hepatitis, membranoproliferative glomerulonephritis, peripheral neuropathy, diffuse vasculitis, and, less frequently, interstitial lung involvement and endocrine disorders. Some patients may develop lymphatic and hepatic malignancies, usually as a late complication. MC may be associated with numerous infectious or immunological diseases. When isolated, MC may represent a distinct disease, the so-called 'essential' MC. The etiopathogenesis of MC is not completely understood. Hepatitis C virus (HCV) infection is suggested to play a causative role, with the contribution of genetic and/or environmental factors. Moreover, MC may be associated with other infectious agents or immunological disorders, such as human immunodeficiency virus (HIV) infection or primary Sjögren's syndrome. Diagnosis is based on clinical and laboratory findings. Circulating mixed cryoglobulins, low C4 levels and orthostatic skin purpura are the hallmarks of the disease. Leukocytoclastic vasculitis involving medium- and, more often, small-sized blood vessels is the typical pathological finding, easily detectable by means of skin biopsy of recent vasculitic lesions. Differential diagnoses include a wide range of systemic, infectious and neoplastic disorders, mainly autoimmune hepatitis, Sjögren's syndrome, polyarthritis, and B

  6. Non-seagrass meadow sedimentary facies of the Pontinian Islands, Tyrrhenian Sea: A modern example of mixed carbonate siliciclastic sedimentation

    NASA Astrophysics Data System (ADS)

    Brandano, Marco; Civitelli, Giacomo

    2007-10-01

    epibathyal zones that represent shelf-break and upper slope sedimentation. The Maerl facies (F4a,b; mf4a,b) and the skeletal sands (F2a,b; mf2a1, mf2a2, mf2b) fall within the circalittoral zone. The circalittoral zone in the water depth interval between 82 m and 112 m display relict facies (F6, mf6). Finally facies F5 (Siliciclastic sands) includes subfacies F5b (mf5b), located in the circalittoral zone at depths of 49 to 101 mwd and restricted to the western and eastern sectors of Ponza, and subfacies F5a in the upper infralittoral zone (15 mwd/25 mwd) where erosional processes prevail. Carbonate content analyses indicate that maximum carbonate production on the Pontinian shelf took place in the 60-80 mwd interval. Facies F4 (Maerl) represents the environment characterized by the highest carbonate production rates. In the Pontian area siliciclastic-carbonate mixing took place in the infralittoral zone and in the lower circalittoral zone. In the infralittoral zone erosional processes on the rocky shoreline produced lithoclasts and vulcanoclastic deposits that were reworked by wave-induced near-shore currents. In the lower circalittoral zone the prolific production by photic biota (red algae) ends, while skeletal remains of the aphotic environment mixes with planktonic sediments characterized by low carbonate values. Sand (63 μm-2 mm) is the dominant grain size class, however gravel-dominated facies (F4 Maerl) are present in water depths (50 to 112 mwd) which are significantly below the storm wave base. Glauconite mineralization appears on the Pontinian shelf from 50 mwd and increases in abundance along the deeper bathymetries. The compositional characteristics of relict facies F6 shows the concurrence of biota assemblages of the infralittoral and circalittoral zones, likely representing the record of the last Holocene transgressive event (18 ky) and expressed by the overlapping of components of different environments.

  7. Mixing in explosions

    SciTech Connect

    Kuhl, A.L.

    1993-12-01

    Explosions always contain embedded turbulent mixing regions, for example: boundary layers, shear layers, wall jets, and unstable interfaces. Described here is one particular example of the latter, namely, the turbulent mixing occurring in the fireball of an HE-driven blast wave. The evolution of the turbulent mixing was studied via two-dimensional numerical simulations of the convective mixing processes on an adaptive mesh. Vorticity was generated on the fireball interface by baroclinic effects. The interface was unstable, and rapidly evolved into a turbulent mixing layer. Four phases of mixing were observed: (1) a strong blast wave phase; (2) and implosion phase; (3) a reshocking phase; and (4) an asymptotic mixing phase. The flowfield was azimuthally averaged to evaluate the mean and r.m.s. fluctuation profiles across the mixing layer. The vorticity decayed due to a cascade process. This caused the corresponding enstrophy parameter to increase linearly with time -- in agreement with homogeneous turbulence calculations of G.K. Batchelor.

  8. Mixing in astrophysics

    SciTech Connect

    Fryer, Christopher Lee

    2011-01-07

    Turbulent mixing plays a vital role in many fields in astronomy. Here I review a few of these sites, discuss the importance of this turbulent mixing and the techniques used by astrophysicists to solve these problems.

  9. Mixed methods research.

    PubMed

    Halcomb, Elizabeth; Hickman, Louise

    2015-04-08

    Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

  10. Mixing and compaction temperatures for Superpave mixes

    NASA Astrophysics Data System (ADS)

    Yildirim, Yetkin

    According to Superpave mixture design, gyratory specimens are mixed and compacted at equiviscous binder temperatures corresponding to viscosities of 0.17 and 0.28 Pa.s. respectively. These were the values previously used in the Marshal mix design method to determine optimal mixing and compaction temperatures. In order to estimate the appropriate mixing and compaction temperatures for Superpave mixture design, a temperature-viscosity relationship for the binder needs to be developed (ASTM D 2493, Calculation of Mixing and Compaction Temperatures). The current approach is simple and provides reasonable temperatures for unmodified binders. However, some modified binders have exhibited unreasonably high temperatures for mixing and compaction using this technique. These high temperatures can result in construction problems, damage of asphalt, and production of fumes. Heating asphalt binder to very high temperatures during construction oxidizes the binder and separates the polymer from asphalt binder. It is known that polymer modified asphalt binders have many benefits to the roads, such as; increasing rutting resistance, enhancing low temperature cracking resistance, improving traction, better adhesion and cohesion, elevating tensile strength which are directly related to the service life of the pavement. Therefore, oxidation and separation of the polymer from the asphalt binder results in reduction of the service life. ASTM D 2493 was established for unmodified asphalt binders which are Newtonian fluids at high temperatures. For these materials, viscosity does not depend on shear rate. However, most of the modified asphalt binders exhibit a phenomenon known as pseudoplasticity, where viscosity does depend on shear rate. Thus, at the high shear rates occurring during mixing and compaction, it is not necessary to go to very high temperatures. This research was undertaken to determine the shear rate during compaction such that the effect of this parameter could be

  11. Mixed oxide solid solutions

    DOEpatents

    Magno, Scott; Wang, Ruiping; Derouane, Eric

    2003-01-01

    The present invention is a mixed oxide solid solution containing a tetravalent and a pentavalent cation that can be used as a support for a metal combustion catalyst. The invention is furthermore a combustion catalyst containing the mixed oxide solid solution and a method of making the mixed oxide solid solution. The tetravalent cation is zirconium(+4), hafnium(+4) or thorium(+4). In one embodiment, the pentavalent cation is tantalum(+5), niobium(+5) or bismuth(+5). Mixed oxide solid solutions of the present invention exhibit enhanced thermal stability, maintaining relatively high surface areas at high temperatures in the presence of water vapor.

  12. Cement mixing with vibrator

    SciTech Connect

    Allen, T.E.

    1991-07-09

    This patent describes a method of cementing a casing string in a bore hole of a well. It comprises introducing water and dry cement material into a mixing vessel; mixing the water and dry cement material in the mixing vessel to form a cement slurry, the slurry including lumps of the dry cement material, the mixing including steps of: agitating the slurry; and while agitating the slurry, transmitting vibrational energy into the slurry and thereby aiding disintegration and subsequent wetting of the lumps of the dry cement material in the slurry; and pumping the slurry into an annulus between the casing string and the bore hole.

  13. Mixed waste minimization/mixed waste avoidance

    SciTech Connect

    Todisco, L.R.

    1994-12-31

    This presentation describes methods for the minimization and volume reduction of low-level radioactive and mixed wastes. Many methods are presented including: source reduction, better waste monitoring activities, waste segregation, recycling, administrative controls, and optimization of waste-generating processes.

  14. Admission mixing duct assembly

    NASA Technical Reports Server (NTRS)

    Orlando, Robert J. (Inventor); Dunbar, Lawrence W. (Inventor)

    1995-01-01

    A variable cycle jet engine is provided with a mixing duct assembly which mixes core engine exhaust gas with bypass air when the engine is operating in a turbofan mode and which blocks flow from the core engine and isolates the core engine from the bypass flow when the engine is operating as a ramjet.

  15. Dilution Zone Mixing

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1983-01-01

    Studies to characterize dilution zone mixing; experiments on the effects of free-stream turbulence on a jet in crossflow; and the development of an interactive computer code for the analysis of the mixing of jets with a confined crossflow are reviewed.

  16. Microfluidic Mixing: A Review

    PubMed Central

    Lee, Chia-Yen; Chang, Chin-Lung; Wang, Yao-Nan; Fu, Lung-Ming

    2011-01-01

    The aim of microfluidic mixing is to achieve a thorough and rapid mixing of multiple samples in microscale devices. In such devices, sample mixing is essentially achieved by enhancing the diffusion effect between the different species flows. Broadly speaking, microfluidic mixing schemes can be categorized as either “active”, where an external energy force is applied to perturb the sample species, or “passive”, where the contact area and contact time of the species samples are increased through specially-designed microchannel configurations. Many mixers have been proposed to facilitate this task over the past 10 years. Accordingly, this paper commences by providing a high level overview of the field of microfluidic mixing devices before describing some of the more significant proposals for active and passive mixers. PMID:21686184

  17. Theory for Neutrino Mixing

    NASA Astrophysics Data System (ADS)

    He, Xiao-Gang

    2016-07-01

    Since the discovery of neutrino oscillations, for which Takaaki Kajita and Arthur B. McDonald were awarded the 2015 Nobel prize in physics, tremendous progresses have been made in measuring the mixing angles which determine the oscillation pattern. A lot of theoretical efforts have been made to understand how neutrinos mix with each other. Present data show that in the standard parameterization of the mixing matrix, θ23 is close to π/4 and the CP violating phase is close to - π/2. In this talk I report results obtained in arXiv:1505.01932 (Phys. Lett. B750(2015)620) and arXive:1404.01560 (Chin. J. Phys.53(2015)100101) and discuss some implications for theoretical model buildings for such mixing pattern. Specific examples for neutrino mixing based on A4 family symmetry are given.

  18. High-mix insulins

    PubMed Central

    Kalra, Sanjay; Farooqi, Mohammad Hamed; El-Houni, Ali E.

    2015-01-01

    Premix insulins are commonly used insulin preparations, which are available in varying ratios of different molecules. These drugs contain one short- or rapid-acting, and one intermediate- or long-acting insulin. High-mix insulins are mixtures of insulins that contain 50% or more than 50% of short-acting insulin. This review describes the clinical pharmacology of high-mix insulins, including data from randomized controlled trials. It suggests various ways, in which high-mix insulin can be used, including once daily, twice daily, thrice daily, hetero-mix, and reverse regimes. The authors provide a rational framework to help diabetes care professionals, identify indications for pragmatic high-mix use. PMID:26425485

  19. MHD turbulent mixing layers

    SciTech Connect

    Esquivel, A.; Lazarian, A.; Benjamin, R.A.; Cho, J.; Leitner, S.N.

    2005-09-28

    Turbulent mixing layers have been proposed to explain observations of line ratios of highly ionized elements in the interstellar medium. We present preliminary results of numerical simulations of turbulent mixing layers in a magnetized medium. We developed a MHD code with radiative cooling. The magnetic field is expected to be a controlling factor by suppressing instabilities that lead to the turbulent mixing. Our results suggest that the difference in turbulent mixing in the unmagnetized case as compared to the case of a weak magnetic field, {beta} = Pgas/Pmag {approx} 10, is insignificant. With a more thorough exploration of parameter space, this work will provide more reliable diagnostics of turbulent mixing layers than those available today.

  20. ADVANCED MIXING MODELS

    SciTech Connect

    Lee, S; Richard Dimenna, R; David Tamburello, D

    2008-11-13

    The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four dual-nozzle jet mixers located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The work described in this report establishes the basis for further development of the theory leading to the identified mixing indicators, the benchmark analyses demonstrating their consistency with widely accepted correlations, and the application of those indicators to SRS waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in height from zero to 10 ft. The sludge has been characterized and modeled as micron-sized solids, typically 1 to 5 microns, at weight fractions as high as 20 to 30 wt%, specific gravities to 1.4, and viscosities up to 64 cp during motion. The sludge is suspended and mixed through the use of submersible slurry jet pumps. To suspend settled sludge, water is added to the tank as a slurry medium and stirred with the jet pump. Although there is considerable technical literature on mixing and solid suspension in agitated tanks, very little literature has been published on jet mixing in a large-scale tank. If shorter mixing times can be shown to support Defense Waste Processing Facility (DWPF) or other feed requirements, longer pump lifetimes can be achieved with associated operational cost and

  1. ADVANCED MIXING MODELS

    SciTech Connect

    Lee, S; Dimenna, R; Tamburello, D

    2011-02-14

    The process of recovering and processing High Level Waste (HLW) the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank with one to four mixers (pumps) located within the tank. The typical criteria to establish a mixed condition in a tank are based on the number of pumps in operation and the time duration of operation. To ensure that a mixed condition is achieved, operating times are typically set conservatively long. This approach results in high operational costs because of the long mixing times and high maintenance and repair costs for the same reason. A significant reduction in both of these costs might be realized by reducing the required mixing time based on calculating a reliable indicator of mixing with a suitably validated computer code. The focus of the present work is to establish mixing criteria applicable to miscible fluids, with an ultimate goal of addressing waste processing in HLW tanks at SRS and quantifying the mixing time required to suspend sludge particles with the submersible jet pump. A single-phase computational fluid dynamics (CFD) approach was taken for the analysis of jet flow patterns with an emphasis on the velocity decay and the turbulent flow evolution for the farfield region from the pump. Literature results for a turbulent jet flow are reviewed, since the decay of the axial jet velocity and the evolution of the jet flow patterns are important phenomena affecting sludge suspension and mixing operations. The work described in this report suggests a basis for further development of the theory leading to the identified mixing indicators, with benchmark analyses demonstrating their consistency with widely accepted correlations. Although the indicators are somewhat generic in nature, they are applied to Savannah River Site (SRS) waste tanks to provide a better, physically based estimate of the required mixing time. Waste storage tanks at SRS contain settled sludge which varies in

  2. Mixing in Microfluidic Systems

    NASA Astrophysics Data System (ADS)

    Beskok, A.

    Flow and species transport in micro-scales experience laminar, even Stokes flow conditions. In absence of turbulence, species mixing becomes diffusion dominated, and requires very long mixing length scales (l m ). This creates significant challenges in the design of Lab-on-a-chip (LOC) devices, where mixing of macromolecules and biological species with very low mass diffusivities are often desired. The objectives of this chapter are to introduce concepts relevant to mixing enhancement in microfluidic systems, and guide readers in the design of new mixers via numerical simulations. A distinguishing feature is the identification of flow kinematics that enhance mixing, followed with systematic characterization of mixing as a function of the Schmidt number at fixed kinematic conditions. In this chapter, we briefly review the routes to achieve chaotic advection in Stokes flow, and then illustrate the characteri-zation of a continuous flow chaotic stirrer via appropriate numerical tools, including the Poincaré section, finite time Lyapunov exponent, and mixing index.

  3. The mixing of fluids

    SciTech Connect

    Ottino, J.M.

    1989-01-01

    What do the eruption of Krakatau, the manufacture of puff pastry and the brightness of stars have in common Each involves some aspect of mixing. Mixing also plays a critical role in modern technology. Chemical engineers rely on mixing to ensure that substances react properly, to produce polymer blends that exhibit unique properties and to disperse drag-reducing agents in pipelines. Yet in spite of its of its ubiquity in nature and industry, mixing is only imperfectly under-stood. Indeed, investigators cannot even settle on a common terminology: mixing is often referred to as stirring by oceanographers and geophysicists, as blending by polymer engineers and as agitation by process engineers. Regardless of what the process is called, there is little doubt that it is exceedingly complex and is found in a great variety of systems. In constructing a theory of fluid mixing, for example, one has to take into account fluids that can be miscible or partially miscible and reactive or inert, and flows that are slow and orderly or very fast and turbulent. It is therefore not surprising that no single theory can explain all aspect of mixing in fluids and that straightforward computations usually fail to capture all the important details. Still, both physical experiments and computer simulations can provide insight into the mixing process. Over the past several years the authors and his colleague have taken both approaches in an effort to increase understanding of various aspect of the process-particularly of mixing involving slow flows and viscous fluids such as oils.

  4. Nearly discontinuous chaotic mixing

    SciTech Connect

    Sharp, David Howland; Lim, Hyun K; Yu, Yan; Glimm, James G

    2009-01-01

    A new scientific approach is presented for a broad class of chaotic problems involving a high degree of mixing over rapid time scales. Rayleigh-Taylor and Richtmyer-Meshkov unstable flows are typical of such problems. Microscopic mixing properties such as chemical reaction rates for turbulent mixtures can be obtained with feasible grid resolution. The essential dependence of (some) fluid mixing observables on transport phenomena is observed. This dependence includes numerical as well as physical transport and it includes laminar as well as turbulent transport. A new approach to the mathematical theory for the underlying equations is suggested.

  5. Liquid air mixing system

    NASA Technical Reports Server (NTRS)

    Martin, Robert B. (Inventor)

    1997-01-01

    A device for mixing liquid nitrogen and liquid oxygen to form liquid air. The mixing device consists of a tube for transferring liquid oxygen positioned within a tube for transferring liquid nitrogen. Supply vessels for liquid oxygen and liquid nitrogen are equally pressurized and connected to the appropriate tubes. Liquid oxygen and nitrogen flow from the supply vessels through the respective tubes and are mixed to form liquid air upon exiting the outlets of the tube. The resulting liquid air is transferred to a holding vessel.

  6. Mixing method and apparatus

    DOEpatents

    Green, Norman W.

    1982-06-15

    Method of mixing particulate materials comprising contacting a primary source and a secondary source thereof whereby resulting mixture ensues; preferably at least one of the two sources has enough motion to insure good mixing and the particulate materials may be heat treated if desired. Apparatus for such mixing comprising an inlet for a primary source, a reactor communicating therewith, a feeding means for supplying a secondary source to the reactor, and an inlet for the secondary source. Feeding means is preferably adapted to supply fluidized materials.

  7. Remotely controllable mixing system

    NASA Technical Reports Server (NTRS)

    Belew, R. R. (Inventor)

    1986-01-01

    This invention relates to a remotely controllable mixing system in which a plurality of mixing assemblies are arranged in an annular configuration, and wherein each assembly employs a central chamber and two outer, upper and lower chambers. Valves are positioned between chambers, and these valves for a given mixing assembly are operated by upper and lower control rotors, which in turn are driven by upper and lower drive rotors. Additionally, a hoop is compressed around upper control rotors and a hoop is compressed around lower control rotors to thus insure constant frictional engagement between all control rotors and drive rotors. The drive rollers are driven by a motor.

  8. Guidelines for mixed waste minimization

    SciTech Connect

    Owens, C.

    1992-02-01

    Currently, there is no commercial mixed waste disposal available in the United States. Storage and treatment for commercial mixed waste is limited. Host States and compacts region officials are encouraging their mixed waste generators to minimize their mixed wastes because of management limitations. This document provides a guide to mixed waste minimization.

  9. Mixed-Media Owls

    ERIC Educational Resources Information Center

    Schultz, Kathy

    2010-01-01

    The fun of creating collages is there are unlimited possibilities for the different kinds of materials one can use. In this article, the author describes how her eighth-grade students created an owl using mixed media.

  10. Mixed-Media Owls

    ERIC Educational Resources Information Center

    Schultz, Kathy

    2010-01-01

    The fun of creating collages is there are unlimited possibilities for the different kinds of materials one can use. In this article, the author describes how her eighth-grade students created an owl using mixed media.

  11. Artificial upwelling and mixing

    SciTech Connect

    Not Available

    1989-01-01

    The authors present results related to artificial upwelling and coastal mariculture using deep ocean water and mixing in coastal waters. They discuss the application of research results for marine waste disposal.

  12. Asymmetric antiproton debuncher: No bad mixing, more good mixing

    SciTech Connect

    Visnjic, V.

    1994-07-01

    An asymmetric lattice for the Fermilab Antiproton Debuncher is designed. The lattice has zero mixing between the pickups and the kickers (bad mixing) while the mixing in the rest of the machine (good mixing) can be varied (even during the operation of the machine) in order to optimize the stochastic cooling. As an example, a lattice with zero bad mixing and twice the good mixing is presented. The betatron cooling rate in this lattice is twice its present value.

  13. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 10 rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  14. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 19 equivalent rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  15. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 19 equivalent rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  16. Mixed waste management options

    SciTech Connect

    Owens, C.B.; Kirner, N.P.

    1991-12-31

    Disposal fees for mixed waste at proposed commercial disposal sites have been estimated to be $15,000 to $40,000 per cubit foot. If such high disposal fees are imposed, generators may be willing to apply extraordinary treatment or regulatory approaches to properly dispose of their mixed waste. This paper explores the feasibility of several waste management scenarios and attempts to answer the question: Can mixed waste be managed out of existence? Existing data on commercially generated mixed waste streams are used to identify the realm of mixed waste known to be generated. Each waste stream is evaluated from both a regulatory and technical perspective in order to convert the waste into a strictly low-level radioactive or a hazardous waste. Alternative regulatory approaches evaluated in this paper include a delisting petition, no migration petition, and a treatability variance. For each waste stream, potentially available treatment options are identified that could lead to these variances. Waste minimization methodology and storage for decay are also considered. Economic feasibility of each option is discussed broadly.

  17. [Mixed states and schizophrenia].

    PubMed

    Fakra, E; Belzeaux, R; Pringuey, D; Cermolacce, M; Corréard, N; Micoulaud-Franchi, J-A; Azorin, J-M

    2013-12-01

    Because of their compilation of contrasted symptoms and their variable clinical presentation, mixed episodes have been withdrawn from the DSM. However, mixed states question not only the bonds between depression and mania, but also the distinction between bipolar disorders and schizophrenia. Indeed, doubts about the dichotomy introduced by Kraepelin between bipolar disorders and schizophrenia is as old as the nosolgy itself, as attest the later works of this author revealing his hesitations on his own classification. But findings here reviewed issued from recent technical advances, particularly in the imaging and genetic fields, offer a better understanding of the boundaries between these two disorders. Yet, when confronted to an acute episode, clinicians may find it challenging to distinguish a mixed state from a schizophrenic relapse. Indeed, there is no pathognomonic manifestation allowing to retain a diagnosis with confidence. The physician will therefore have to identify a pattern of signs, which will orient his assessment with no certainty. Thus, negative rather than affective or psychotic symptomatology appears to be useful in discriminating schizophrenia (or schizoaffective) disorders from mixed mania. However, a conclusion during this acute stage appears in definitive a formal exercise, first because the final diagnosis will only be ascertained once the symptoms are amended, and second because, according to our classifications, a mood episode, including mania and mixed mania, can be observed without ruling out the diagnosis of schizophrenia. Copyright © 2013 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

  18. Natural convective mixing flows

    NASA Astrophysics Data System (ADS)

    Ramos, Eduardo; de La Cruz, Luis; del Castillo, Luis

    1998-11-01

    Natural convective mixing flows. Eduardo Ramos and Luis M. de La Cruz, National University of Mexico and Luis Del Castillo San Luis Potosi University. The possibility of mixing a fluid with a natural convective flow is analysed by solving numerically the mass, momentum and energy equations in a cubic container. Two opposite vertical walls of the container are assumed to have temperatures that oscillate as functions of time. The phase of the oscillations is chosen in such a way that alternating corrotating vortices are formed in the cavity. The mixing efficiency of this kind of flow is examined with a Lagrangian tracking technique. This work was partially financed by CONACyT-Mexico project number GE0044

  19. Remotely controllable mixing system

    NASA Technical Reports Server (NTRS)

    Belew, Robert R. (Inventor)

    1987-01-01

    A remotely controllable mixing system (210) in which a plurality of mixing assemblies (10a-10e) are arranged in an annular configuration, and wherein each assembly (10) employs a central chamber (16) and two outer, upper and lower, chambers (12, 14). Valves (18, 20) are positioned between chambers, and these valves (18, 20) for a given mixing assembly (10) are operated by upper and lower control rotors (29), which in turn are driven by upper and lower drive rotors (270, 270b). Additionally, a hoop (278) is compressed around upper control rotors (29) and a hoop (278b) is compressed around lower control rotors (29) to thus insure constant frictional engagement between all control rotors (29) and drive rotors (270, 270b). The drive rollers (270, 270b) are driven by a motor (213).

  20. Dilution jet mixing program

    NASA Technical Reports Server (NTRS)

    Srinivasan, R.; Coleman, E.; Johnson, K.

    1984-01-01

    Parametric tests were conducted to quantify the mixing of opposed rows of jets (two-sided injection) in a confined cross flow. Results show that jet penetrations for two sided injections are less than that for single-sided injections, but the jet spreading rates are faster for a given momentum ratio and orifice plate. Flow area convergence generally enhances mixing. Mixing characteristics with asymmetric and symmetric convergence are similar. For constant momentum ratio, the optimum S/H(0) with in-line injections is one half the optimum value for single sided injections. For staggered injections, the optimum S/H(0) is twice the optimum value for single-sided injection. The correlations developed predicted the temperature distributions within first order accuracy and provide a useful tool for predicting jet trajectory and temperature profiles in the dilution zone with two-sided injections.

  1. Mixed waste: Proceedings

    SciTech Connect

    Moghissi, A.A.; Blauvelt, R.K.; Benda, G.A.; Rothermich, N.E.

    1993-12-31

    This volume contains the peer-reviewed and edited versions of papers submitted for presentation a the Second International Mixed Waste Symposium. Following the tradition of the First International Mixed Waste Symposium, these proceedings were prepared in advance of the meeting for distribution to participants. The symposium was organized by the Mixed Waste Committee of the American Society of Mechanical Engineers. The topics discussed at the symposium include: stabilization technologies, alternative treatment technologies, regulatory issues, vitrification technologies, characterization of wastes, thermal technologies, laboratory and analytical issues, waste storage and disposal, organic treatment technologies, waste minimization, packaging and transportation, treatment of mercury contaminated wastes and bioprocessing, and environmental restoration. Individual abstracts are catalogued separately for the data base.

  2. Mixed crystal organic scintillators

    DOEpatents

    Zaitseva, Natalia P; Carman, M Leslie; Glenn, Andrew M; Hamel, Sebastien; Hatarik, Robert; Payne, Stephen A; Stoeffl, Wolfgang

    2014-09-16

    A mixed organic crystal according to one embodiment includes a single mixed crystal having two compounds with different bandgap energies, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source, wherein the signal response signature does not include a significantly-delayed luminescence characteristic of neutrons interacting with the organic crystal relative to a luminescence characteristic of gamma rays interacting with the organic crystal. According to one embodiment, an organic crystal includes bibenzyl and stilbene or a stilbene derivative, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source.

  3. Mixing navigation on networks

    NASA Astrophysics Data System (ADS)

    Zhou, Tao

    2008-05-01

    In this article, we propose a mixing navigation mechanism, which interpolates between random-walk and shortest-path protocol. The navigation efficiency can be remarkably enhanced via a few routers. Some advanced strategies are also designed: For non-geographical scale-free networks, the targeted strategy with a tiny fraction of routers can guarantee an efficient navigation with low and stable delivery time almost independent of network size. For geographical localized networks, the clustering strategy can simultaneously increase efficiency and reduce the communication cost. The present mixing navigation mechanism is of significance especially for information organization of wireless sensor networks and distributed autonomous robotic systems.

  4. Turbulence and Interfacial Mixing

    SciTech Connect

    Glimm, James; Li, Xiaolin

    2005-03-15

    The authors study mix from analytical and numerical points of view. These investigations are linked. The analytical studies (in addition to laboratory experiments) provide bench marks for the direct simulation of mix. However, direct simulation is too detailed to be useful and to expensive to be practical. They also consider averaged equations. Here the major issue is the validation of the closure assumptions. They appeal to the direct simulation methods for this step. They have collaborated with several NNSA teams; moreover, Stony Brook alumni (former students, faculty and research collaborators) presently hold staff positions in NNSA laboratories.

  5. Atomization and Mixing Study

    NASA Technical Reports Server (NTRS)

    Ferrenberg, A.; Hunt, K.; Duesberg, J.

    1985-01-01

    The primary objective was the obtainment of atomization and mixing performance data for a variety of typical liquid oxygen/hydrocarbon injector element designs. Such data are required to establish injector design criteria and to provide critical inputs to liquid rocket engine combustor performance and stability analysis, and computational codes and methods. Deficiencies and problems with the atomization test equipment were identified, and action initiated to resolve them. Test results of the gas/liquid mixing tests indicated that an assessment of test methods was required. A series of 71 liquid/liquid tests were performed.

  6. Atomization and mixing study

    NASA Technical Reports Server (NTRS)

    Ferrenberg, A.; Jaqua, V. W.

    1983-01-01

    The state of the art in atomization and mixing for triplet, pentad, and coaxial injectors is described. Injectors that are applicable for LOX/hydrocarbon propellants and main chamber and fuel rich preburner/gas generator mixture ratios are of special interest. Various applicable correlating equations and parameters as well as test data found in the literature are presented. The validity, utility, and important aspects of these data and correlations are discussed and the measurement techniques used are evaluated. Propellant mixing tests performed are described and summarized, results are reported, and tentative conclusions are included.

  7. Sylgard® Mixing Study

    SciTech Connect

    Bello, Mollie; Welch, Cynthia F.; Goodwin, Lynne Alese; Keller, Jennie

    2014-08-22

    Sylgard® 184 and Sylgard® 186 silicone elastomers form Dow Corning® are used as potting agents across the Nuclear Weapons Complex. A standardized mixing procedure is required for filled versions of these products. The present study is a follow-up to a mixing study performed by MST-7 which established the best mixing procedure to use when adding filler to either 184 or 186 base resins. The most effective and consistent method of mixing resin and curing agent for three modified silicone elastomer recipes is outlined in this report. For each recipe, sample size, mixing type, and mixing time was varied over 10 separate runs. The results show that the THINKY™ Mixer gives reliable mixing over varying batch sizes and mixing times. Hand Mixing can give improved mixing, as indicated by reduced initial viscosity; however, this method is not consistent.

  8. Long-term effect of the Kärdla crater (Hiiumaa, Estonia) on Late Ordovician carbonate sedimentation

    NASA Astrophysics Data System (ADS)

    Ainsaar, Leho; Suuroja, Kalle; Semidor, Maili

    Kärdla impact crater, 4 km in diameter, was formed in the early Caradoc (Late Ordovician) in the Baltoscandian shelf sea, a sediment-starved temperate-water carbonate basin. The Upper Ordovician post-impact sediments that cover the Kärdla crater are 15-275 m thick. The crater rimwall is composed of three separate basement rises that formed islands or shoals in the Late Ordovician shelf sea and influenced the sedimentation in the surrounding area. The rises provide the means to study the shallow-water sedimentary environments and sea-level history. This may be one of the few cases, where shore environments of the Baltoscandian Ordovician palaeobasin are preserved in the geological record. Lithofacies distribution was studied in the crater area from data of about 100 drillcores. Grain size distribution and composition of the non-carbonate material were analyzed in six core sections in order to reconstruct the history of crater erosion. The post-impact marine deposits lie on a partly redeposited and mixed ejecta layer derived from the Cambrian to Lower Ordovician silici-clastic deposits in the target area. Beds of marine carbonate sediments of Caradoc age, wackestones and mudstones, on-lap on the slope of the crater rim. A shift of sedimentation towards the crater rim during the Caradoc is evidence of a relative sea-level rise, which was a combination of early Caradoc eustatic rise, crater area subsidence, and compaction of pre-impact and impact sediments. The occurrences of coarse sand and gravel in specific stratigraphic intervals reflect the intensity of wave action and sea-level changes in the area. A detailed curve of sea-level changes during Late Ordovician has been constructed and different post-impact sedimentation models are presented for the crater area. The sedimentation pattern changed during the Caradoc as a result of sea-level rise and climatic change. The synchronous appearance of echinoderm bioclastic accumulations in shoal areas in Estonian mainland

  9. Radial Mixing in Turbomachines

    DTIC Science & Technology

    1991-03-31

    Belgium March 31, 1991 Final Scientific Report June 1, 1989 - July 31, 1990 VUB -STR -17 Approved for public release; distribution unlimited. - Prepared ...secondary flows and turbulence as sources of mixing was investigated by conducting experiments using hot-wire anemometry and ehtylene tracer gas

  10. Stabilizer for mixed fuels

    SciTech Connect

    Yamamura, M.; Igarashi, T.; Ukigai, T.

    1984-03-13

    A stabilizer for mixed fuels containing a reaction product obtained by reacting (1) a polyol having at least 3 hydroxyl groups in the molecule and a molecular weight of 400-10,000 with (2) an epihalohydrin, as the principal component.

  11. Mixing and Transport.

    ERIC Educational Resources Information Center

    Ditmars, John D.

    1978-01-01

    Presents a literature review of longitudinal dispersion, mixing and transport in streams, rivers, lakes, reservoirs, estuaries, and oceans. This review covers also: (1) fluid-solid mixtures and (2) oil spill behavior. A list of 189 references published in 1976 and 1977 is presented. (HM)

  12. True Anonymity Without Mixes

    NASA Astrophysics Data System (ADS)

    Molina-Jimenez, C.; Marshall, L.

    2002-04-01

    Anonymizers based on mix computers interposed between the sender and the receiver of an e-mail message have been used in the Internet for several years by senders of e-mail messages who do not wish to disclose their identity. Unfortunately, the degree of anonymity provided by this paradigm is limited and fragile. First, the messages sent are not truly anonymous but pseudo-anonymous since one of the mixes, at least, always knows the sender's identity. Secondly, the strength of the system to protect the sender's identity depends on the ability and the willingness of the mixes to keep the secret. If the mixes fail, the sender/'s anonymity is reduced to pieces. In this paper, we propose a novel approach for sending truly anonymous messages over the Internet where the anonymous message is sent from a PDA which uses dynamically assigned temporary, non-personal, random IP and MAC addresses. Anonymous E-cash is used to pay for the service.

  13. Mixed-Initiative Clustering

    ERIC Educational Resources Information Center

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  14. Mixed-Initiative Clustering

    ERIC Educational Resources Information Center

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  15. Mixing and Transport.

    ERIC Educational Resources Information Center

    Ditmars, John D.

    1978-01-01

    Presents a literature review of longitudinal dispersion, mixing and transport in streams, rivers, lakes, reservoirs, estuaries, and oceans. This review covers also: (1) fluid-solid mixtures and (2) oil spill behavior. A list of 189 references published in 1976 and 1977 is presented. (HM)

  16. Mixed valent metals

    NASA Astrophysics Data System (ADS)

    Riseborough, P. S.; Lawrence, J. M.

    2016-08-01

    We review the theory of mixed-valent metals and make comparison with experiments. A single-impurity description of the mixed-valent state is discussed alongside the description of the nearly-integer valent or Kondo limit. The degeneracy N of the f-shell plays an important role in the description of the low-temperature Fermi-liquid state. In particular, for large N, there is a rapid cross-over between the mixed-valent and the Kondo limit when the number of f electrons is changed. We discuss the limitations on the application of the single-impurity description to concentrated compounds such as those caused by the saturation of the Kondo effect and those due to the presence of magnetic interactions between the impurities. This discussion is followed by a description of a periodic lattice of mixed-valent ions, including the role of the degeneracy N. The article concludes with a comparison of theory and experiment. Topics covered include the single-impurity Anderson model, Luttinger’s theorem, the Friedel sum rule, the Schrieffer-Wolff transformation, the single-impurity Kondo model, Kondo screening, the Wilson ratio, local Fermi-liquids, Fermi-liquid sum rules, the Noziéres exhaustion principle, Doniach’s diagram, the Anderson lattice model, the Slave-Boson method, etc.

  17. Experiments in mixed reality

    NASA Astrophysics Data System (ADS)

    Krum, David M.; Sadek, Ramy; Kohli, Luv; Olson, Logan; Bolas, Mark

    2010-01-01

    As part of the Institute for Creative Technologies and the School of Cinematic Arts at the University of Southern California, the Mixed Reality lab develops technologies and techniques for presenting realistic immersive training experiences. Such experiences typically place users within a complex ecology of social actors, physical objects, and collections of intents, motivations, relationships, and other psychological constructs. Currently, it remains infeasible to completely synthesize the interactivity and sensory signatures of such ecologies. For this reason, the lab advocates mixed reality methods for training and conducts experiments exploring such methods. Currently, the lab focuses on understanding and exploiting the elasticity of human perception with respect to representational differences between real and virtual environments. This paper presents an overview of three projects: techniques for redirected walking, displays for the representation of virtual humans, and audio processing to increase stress.

  18. Mixing by individual swimmers

    NASA Astrophysics Data System (ADS)

    Pushkin, Dmitri; Shum, Henry; Yeomans, Julia

    2012-11-01

    Despite their evolutionary and technological importance, different biomixing mechanisms, their effectiveness and universality remain poorly understood. In this talk we focus on the Lagrangian transport of the surrounding fluid by swimmers. Low Re passive tracers advected by swimmers move in loops that are, in general, almost closed. We analyze the reasons for this behavior and, as non-closedness of the loops is a natural requirement for an efficient mixing, propose a classification of possible mechanisms for biogenic mixing. Next, we discuss the universal (common to all swimmers) and the swimmer-dependent features of the resulting tracer displacements and analyze the Darwin drift, the total fluid volume displaced by a swimmer passing from and to infinity. We show that the Darwin drift is finite for force-free swimmers and can be decomposed into a universal and a swimmer-dependent part. We illustrate our consideration with examples for model swimmers and biological data.

  19. Nozzle mixing apparatus

    SciTech Connect

    Mensink, D.L.

    1992-12-31

    This invention is comprised of a nozzle device for causing two fluids to mix together. In particular, a spray nozzle comprise two hollow, concentric housings, an inner housing and an outer housing. The inner housing has a channel formed therethrough for a first fluid. Its outer surface cooperates with the interior surface of the outer housing to define the second channel for a second fluid. The outer surface of the inner housing and the inner surface of the outer housing each carry a plurality of vanes that interleave but do not touch, each vane of one housing being between two vanes of the other housing. The vanes are curved and the inner surface of the outer housing and the outer surface of the inner housing converge to narrow the second channel. The shape of second channel results in a swirling, accelerating second fluid that will impact the first fluid just past the end of the nozzle where mixing will take place.

  20. Neutrino-Modulino Mixing

    SciTech Connect

    Benakli, K.; Smirnov, A.Y.

    1997-12-01

    We suggest an existence of light singlet fermion, S, which interacts with observable matter only via Planck mass suppressed interaction: {approximately}m{sub 3/2}/M{sub P}, where m{sub 3/2} is the supergravity gravitino mass. If the mass of the singlet equals {approximately}m{sup 2}{sub 3/2}/M{sub P}, then {nu}{sub e}{r_arrow}S resonance conversion solves the solar neutrino problem or leads to observable effects. The {nu}S mixing changes supernova neutrino fluxes and has an impact on the primordial nucleosynthesis. The singlet S can originate as the supersymmetric partner of the moduli fields in supergravity or low energy effective theory stemming from superstrings. The {nu}S mixing may be accompanied by observable R-parity breaking effects. {copyright} {ital 1997} {ital The American Physical Society}

  1. Magnetically driven surface mixing

    NASA Astrophysics Data System (ADS)

    Belkin, M.; Snezhko, A.; Aranson, I. S.; Kwok, W.-K.

    2009-07-01

    Magnetic microparticles suspended on the surface of liquid and energized by vertical alternating magnetic field exhibit complex collective behavior. Various immobile and self-propelled self-assembled structures have been observed. Here, we report on experimental studies of mixing and surface diffusion processes in this system. We show that the pattern-induced surface flows have properties of quasi-two-dimensional turbulence. Correspondingly, the surface advection of tracer particle exhibits properties of Brownian diffusion.

  2. Sedimentologic and tectonic evolution of the Upper Cretaceous-Lower Tertiary succession at Wadi Qena, Egypt

    NASA Astrophysics Data System (ADS)

    Soliman, Mohamed A.; Habib, Mohamed E.; Ahmed, Ezzat A.

    1986-01-01

    The Upper Cretaceous-Lower Tertiary rocks around Wadi Qena, Egypt, represent a mixed siliciclastic-carbonate-phosphorite succession including (from base to top) the Nubia Sandstone, Quseir Shale, Duwi Formation, Dakhla Shale, Tarawan Chalk, Esna Shale and Thebes Formation. Facies and microfacies investigations were carried out. The Nubia Sandstone was deposited by a fluviatile system, whereas the Quseir Shale was laid down by deltaic sedimentation. The Dakhla Shale, Esna Shale and Tarawan Chalk were formed in open marine (pelagic) realms. The Thebes Formation is a shallowing carbonate facies. Phosphorites were accumulated as lag deposits by reworking and winnowing of pre-existing phosphatic materials. The sedimentation of the Upper Cretaceous-Lower Tertiary rocks were affected by regional and local tectonics (i.e., faulting). The latter played a substantial role in the distribution of the different facies particularly the siliciclastic-carbonate facies.

  3. Stochastic neutrino mixing mechanism

    NASA Astrophysics Data System (ADS)

    Guzzo, M. M.; de Holanda, P. C.; Peres, O. L. G.; Zavanin, E. M.

    2013-05-01

    We propose a mechanism which provides an explanation of the Gallium and antineutrino reactor anomalies. Differently from original Pontecorvo’s hypothesis, this mechanism is based on the phenomenological assumption in which the admixture of neutrino mass eigenstates in the moments of neutrino creation and detection can assume different configurations around the admixture parametrized by the usual values of the mixing angles θ12, θ23, and θ13. For simplicity, we assume a Gaussian distribution for the mixing angles in such a way that the average value of this distribution is given by the usual values of the mixing angles, and the width of the Gaussian is denoted by α. We show that the proposed mechanism provides a possible explanation for very short-baseline neutrino disappearance, necessary to accommodate Gallium and antineutrino reactor anomalies, which is not allowed in usual neutrino oscillations based on Pontecorvo’s original hypotheses. We also can describe high-energy oscillation experiments, like LSND, Fermi, and NuTeV, assuming a weakly energy dependent width parameter, α(E), that nicely fits all experimental results.

  4. Flows, Turbulence, and Mixing

    NASA Astrophysics Data System (ADS)

    Lazarian, Alex

    2003-07-01

    HST and FUSE spectra of distant UV-bright sources reveal interstellar absorption lines of high stages of ionization {O VI, C IV, N V, Si IV} arising in many different astrophysical environments such as superbubbles, interstellar chimneys, high-velocity clouds, galaxy halos and cosmic filaments. Turbulence, always present in the magnetized ISM, must mix the hot { 10^6 K} gas with cooler gas within "turbulent mixing layers". Present theory, based on 1D steady-state flows, suggest the line ratios in these layers differ significantly from photoionized gas, radiative shocks, cooling zones, or conduction fronts. These models are use to infer mass and energy fluxes important to understanding the ISM. We propose to develop a suite of 3D time-dependent models that properly calculate turbulent mixing. We will produce synthetic UV absorption lines and optical emission lines directly relevant to HST observations that use GHRS, STIS, and eventually, COS. These models will allow us to explore the sensitivity of the spectral diagnostics to magnetic field strength, turbulence intensity, and relative velocity of the hot and cold gas. We will publish the resulting grid of spectral diagnostics and make them available through the Web.

  5. Mixing kaons with mixed action chiral perturbation theory

    NASA Astrophysics Data System (ADS)

    Aubin, Christopher

    2006-12-01

    We calculate the neutral kaon mixing parameter, BK , to next-to-leading order in mixed action (domain-wall valence with staggered sea quarks) chiral perturbation theory. We find the expres- sion for BK in this mixed-action case only differs from the continuum partially quenched expres- sion by an additional analytic term. Additionally, in preparation for a lattice calculation of BK with a mixed action, we discuss quantitatively the effects of the taste violations as well as finite volume effects.

  6. MixSIAR: advanced stable isotope mixing models in R

    EPA Science Inventory

    Background/Question/Methods The development of stable isotope mixing models has coincided with modeling products (e.g. IsoSource, MixSIR, SIAR), where methodological advances are published in parity with software packages. However, while mixing model theory has recently been ex...

  7. MixSIAR: advanced stable isotope mixing models in R

    EPA Science Inventory

    Background/Question/Methods The development of stable isotope mixing models has coincided with modeling products (e.g. IsoSource, MixSIR, SIAR), where methodological advances are published in parity with software packages. However, while mixing model theory has recently been ex...

  8. The Value of Mixed Methods Research: A Mixed Methods Study

    ERIC Educational Resources Information Center

    McKim, Courtney A.

    2017-01-01

    The purpose of this explanatory mixed methods study was to examine the perceived value of mixed methods research for graduate students. The quantitative phase was an experiment examining the effect of a passage's methodology on students' perceived value. Results indicated students scored the mixed methods passage as more valuable than those who…

  9. Mixed marriages. Some key questions.

    PubMed

    Barbara, A

    1994-01-01

    The author discusses various aspects of intercultural or mixed marriage. Factors considered include trends in different countries; determinants of mixed marriage; cultural and social class differences; and mate selection. (SUMMARY IN FRE AND SPA)

  10. Cornell Mixing Zone Expert System

    EPA Pesticide Factsheets

    This page provides an overview Cornell Mixing Zone Expert System water quality modeling and decision support system designed for environmental impact assessment of mixing zones resulting from wastewater discharge from point sources

  11. Magnetically coupled system for mixing

    DOEpatents

    Miller, III, Harlan; Meichel, George; Legere, Edward; Malkiel, Edwin; Woods, Robert Paul; Ashley, Oliver; Katz, Joseph; Ward, Jason; Petersen, Paul

    2014-04-01

    The invention provides a mixing system comprising a magnetically coupled drive system and a foil for cultivating algae, or cyanobacteria, in an open or enclosed vessel. The invention provides effective mixing, low energy usage, low capital expenditure, and ease of drive system component maintenance while maintaining the integrity of a sealed mixing vessel.

  12. Magnetically coupled system for mixing

    DOEpatents

    Miller, III, Harlan; Meichel, George; Legere, Edward; Malkiel, Edwin; Woods, Robert Paul; Ashley, Oliver; Katz, Joseph; Ward, Jason; Petersen, Paul

    2015-09-22

    The invention provides a mixing system comprising a magnetically coupled drive system and a foil for cultivating algae, or cyanobacteria, in an open or enclosed vessel. The invention provides effective mixing, low energy usage, low capital expenditure, and ease of drive system component maintenance while maintaining the integrity of a sealed mixing vessel.

  13. Mix/Cast Contamination Control

    NASA Technical Reports Server (NTRS)

    Wallentine, M.

    2005-01-01

    Presented is a training handbook for Mix/Cast Contamination Control; a part of a series of training courses to qualify access to Mix/Cast facilities. Contents: List Contamination Control Requirements; Identify foreign objects debris (FOD), Control Areas and their guidelines; Describe environmental monitoring; List Contamination Control Initiatives; Describe concern for Controlled Materials; Identify FOD Controlled Areas in Mix/Cast.

  14. Error Estimates for Mixed Methods.

    DTIC Science & Technology

    1979-03-01

    This paper presents abstract error estimates for mixed methods for the approximate solution of elliptic boundary value problems. These estimates are...then applied to obtain quasi-optimal error estimates in the usual Sobolev norms for four examples: three mixed methods for the biharmonic problem and a mixed method for 2nd order elliptic problems. (Author)

  15. The mixed chemistry problem

    NASA Astrophysics Data System (ADS)

    Guzman-Ramirez, L.; Zijlstra, A. A.; Gesicki, K.; Lagadec, E.; Jones, D.; Millar, T. J.; Woods, P. M.; Chuimin, R. N.

    2014-04-01

    Planetary nebulae (PNe) represent the last stage of evolution of intermediate mass stars (0.8 to 8M⊙) and, hence, by their very nature are fundamental to galactic evolution. The massive envelopes ejected during their earlier evolution (AGB phase) are an important source of recycled material in the form of dust and molecular gas into the interstellar medium. A small fraction of PNe show both O- and C-rich features and are therefore classified as mixed-chemistry objects. The origin of their mixed-chemistry is still uncertain. Our chemical models show that the PAHs may form in irradiated dense tori, and HST images confirm the presence of such tori in some of the objects. Using the VISIR/VLT, we spatially resolved the precise location of the PAHs. We find a dense dusty structures in all of the objects observed. The ionised [SIV] material is located inside the dusty tori, while the PAHs are present at the outer edges of these tori. This confirms that the PAHs formation is due to the photodissociation of CO. In the Galactic Disk, very few PNe have shown to harbour these mixed-chemistry phenomenon. We propose to observe the tori of a sample of bipolar PNe from the Galactic Disk that harbour a close binary system inside them. The chemical models show that the formation of long C-chain molecules is possible to occur in O-rich environments, but the formation of these C-rich molecules require a very dense region (Av˜4). To test this theory we propose to observe the very dense tori of these Galactic Disk PNe and compare these sample with the already observed sample of PNe in the Galactic Bulge (Guzman-Ramirez, et al., 2011;Guzman-Ramirez, et al., 2013, submitted).

  16. The boundary is mixed

    NASA Astrophysics Data System (ADS)

    Bianchi, Eugenio; Haggard, Hal M.; Rovelli, Carlo

    2017-08-01

    We show that in Oeckl's boundary formalism the boundary vectors that do not have a tensor form represent, in a precise sense, statistical states. Therefore the formalism incorporates quantum statistical mechanics naturally. We formulate general-covariant quantum statistical mechanics in this language. We illustrate the formalism by showing how it accounts for the Unruh effect. We observe that the distinction between pure and mixed states weakens in the general covariant context, suggesting that local gravitational processes are naturally statistical without a sharp quantal versus probabilistic distinction.

  17. B Lifetimes and Mixing

    SciTech Connect

    Evans, Harold G.; /Indiana U.

    2009-05-01

    The Tevatron experiments, CDF and D0, have produced a wealth of new B-physics results since the start of Run II in 2001. We've observed new B-hadrons, seen new effects, and increased many-fold the precision with which we know the properties of b-quark systems. In these proceedings, we will discuss two of the most fruitful areas in the Tevatron B-physics program: lifetimes and mixing. We'll examine the experimental issues driving these analyses, present a summary of the latest results, and discuss prospects for the future.

  18. Radial Mixing in Turbomachines.

    DTIC Science & Technology

    1988-02-01

    entrainment rate F force defect thickness f blade force, wake model function (eq 9.3) g wake model function (eq 9.4) H shape factor , H Head’s shape factor h...and wake predictions . A new mixing procedure based on the explicit computation of the full transport equation is proposed. This full computation...8217 caused by an overall non-uniform inlet flow as predicted by a through-flow computation, and an ’end-wall boundary layer passage vortex’. 2.2

  19. Intrinsically mixed states: an appreciation

    NASA Astrophysics Data System (ADS)

    Ruetsche, Laura

    An "intrinsically mixed" state is a mixed state of a system that is (in a sense to be elaborated) 'orthogonal' to every pure state of that system. Although the presence of such states in the quantum theories of infinite systems is well known to those who work with such theories, intrinsically mixed states are virtually unheralded in the philosophical literature. Rob Clifton was thoroughly familiar with intrinsically mixed states. I aim here to introduce them to a wider audience-and to encourage that audience to cultivate their acquaintance by suggesting that intrinsically mixed states undermine assumptions framing standard discussions of the quantum measurement problem.

  20. Mixing incompatibilities and toxic exposures.

    PubMed

    Olson, K R; Shusterman, D J

    1993-01-01

    A number of consumer and commercial products may react, upon inappropriate mixing, to produce substances of greater toxicity than the starting materials. Consumer product mixing incompatibilities have been well documented and warning labels appear on high-risk products. In industry, a wider array of potential mixing incompatibilities exists and includes potential accidents in chemical storage and hazardous material handling. Emergency response personnel are a group who often deal with inadvertent mixing related to transportation and other hazardous materials incidents. This article assembles some better-known examples of toxicologically significant exposures resulting from inadvertent or deliberate mixing of incompatible materials.

  1. Transition mixing study

    NASA Technical Reports Server (NTRS)

    Reynolds, R.; White, C.

    1986-01-01

    A computer model capable of analyzing the flow field in the transition liner of small gas turbine engines is developed. A FORTRAN code has been assembled from existing codes and physical submodels and used to predict the flow in several test geometries which contain characteristics similar to transition liners, and for which experimental data was available. Comparisons between the predictions and measurements indicate that the code produces qualitative results but that the turbulence models, both K-E and algebraic Reynolds Stress, underestimate the cross-stream diffusion. The code has also been used to perform a numerical experiment to examine the effect of a variety of parameters on the mixing process in transition liners. Comparisons illustrate that geometries with significant curvature show a drift of the jet trajectory toward the convex wall and weaker wake region vortices and decreased penetration for jets located on the convex wall of the liner, when compared to jets located on concave walls. Also shown were the approximate equivalency of angled slots and round holes and a technique by which jet mixing correlations developed for rectangular channels can be used for can geometries.

  2. [Mixed states and neuroimaging].

    PubMed

    Kaladjian, A; Belzeaux, R; Micoulaud-Franchi, J A; Cermolacce, M; Fakra, E; Azorin, J-M

    2013-12-01

    Despite the growing number of neuroimaging studies in bipolar disorder over the past years, the brain regions involved in mood dysregulation in this disease are still poorly understood. If some neurofunctional abnormalities seem to be independent of mood state, others were preferentially associated with mania or depression, involving the amygdala and other limbic regions as well as ventral frontal regions, with a likely hemispheric lateralization of these abnormalities according to the thymic state that was examined. Very few imaging studies became interested in bipolar patients in a mixed state, making it harder to connect brain malfunction to a given mood state. However, data obtained so far support the hypothesis of a lateralization of brain abnormalities in relation to bipolar symptomatology, suggesting that neurofonctional abnormalities preferentially located in the right ventral frontal and limbic areas may underlie the depressive component, associated with abnormalities of the left similar regions for the manic component. Identification of brain dysfunctions that may explain the emergence of mixed symptoms will likely provide useful information to better understand the respective roles of each hemisphere in the pathophysiology of bipolar disorder. Copyright © 2013 Sociedade Brasileira de Farmacognosia. Published by Elsevier Masson SAS.. All rights reserved.

  3. Collisional atomic mixing

    NASA Astrophysics Data System (ADS)

    Biersack, Jochen P.

    The collisional mixing of thin metal markers in silicon is investigated with the computer program TRIM-DYNAMIC (T-DYN). This code assumes that at high dose irradiation, the substrate Si or Ge, will get fully amorphized, and the recoil atom can stop in any position after slowing down below a certain final energy Ef (taken here as 3 eV). In order to avoid chemical effects, the system Au marker in a silicon matrix was chosen for the TRIM simulation. The results are in good agreement with the experimental findings, as compiled in the review article by Paine and Averback. Similar collisional mixing effects occur in the process of SIMS or Auger electron depth profiling, and cannot be avoided. An example is given here for a thin layer of arsenic vapor deposited on Si and covered by amorphous silicon. The analysing ion beam in this case was 14.5 keV Cs+ incident at 37° towards the surface normal. In comparison with the SIMS measurements by modern depth profiling equipment, again good agreement was found between the T-DYN results and the experiment.

  4. Wave mixing spectroscopy

    SciTech Connect

    Smith, R.W.

    1980-08-01

    Several new aspects of nonlinear or wave mixing spectroscopy were investigated utilizing the polarization properties of the nonlinear output field and the dependence of this field upon the occurrence of multiple resonances in the nonlinear susceptibility. First, it is shown theoretically that polarization-sensitive detection may be used to either eliminate or controllably reduce the nonresonant background in coherent anti-Stokes Raman spectroscopy, allowing weaker Raman resonances to be studied. The features of multi-resonant four-wave mixing are examined in the case of an inhomogeneously broadened medium. It is found that the linewidth of the nonlinear output narrows considerably (approaching the homogeneous width) when the quantum mechanical expressions for the doubly- and triply-resonant susceptibilities are averaged over a Doppler or strain broadened profile. Experimental studies of nonlinear processes in Pr/sup +3/:LaF/sub 3/ verify this linewidth narrowing, but indicate that this strain broadened system cannot be treated with a single broadening parameter as in the case of Doppler broadening in a gas. Several susceptibilities are measured from which are deduced dipole matrix elements and Raman polarizabilities related to the /sup 3/H/sub 4/, /sup 3/H/sub 6/, and /sup 3/P/sub 0/ levels of the praseodymium ions.

  5. Mixed methods, mixed methodology health services research in practice.

    PubMed

    Johnstone, P Lynne

    2004-02-01

    Mixed methods, mixed methodology research is a little documented but increasingly accepted approach employed to investigate organizational phenomena. The author presents a synthesis of literature that informed the decision to adopt a mixed methods, mixed methodology, dominantly naturalistic study approach to health services research in which she explored the process and organizational consequences of new artifact adoption in surgery. She describes the way whereby a collective case study involving five Australian hospitals yielded quantitative and qualitative data that were analyzed using inductive and/or deductive reasoning. She goes beyond the theoretical rational for employing a mixed methods, mixed methodology approach to present a summative conceptual model of the research process and describe the structural aspects of the dissertation in which the research was reported that should benefit researchers contemplating the value of such an approach.

  6. Radioactive mixed waste disposal

    SciTech Connect

    Jasen, W.G.; Erpenbeck, E.G.

    1993-02-01

    Various types of waste have been generated during the 50-year history of the Hanford Site. Regulatory changes in the last 20 years have provided the emphasis for better management of these wastes. Interpretations of the Atomic Energy Act of 1954 (AEA), the Resource Conservation and Recovery Act of 1976 (RCRA), and the Hazardous and Solid Waste Amendments (HSWA) have led to the definition of radioactive mixed wastes (RMW). The radioactive and hazardous properties of these wastes have resulted in the initiation of special projects for the management of these wastes. Other solid wastes at the Hanford Site include low-level wastes, transuranic (TRU), and nonradioactive hazardous wastes. This paper describes a system for the treatment, storage, and disposal (TSD) of solid radioactive waste.

  7. Mixed Mode Matrix Multiplication

    SciTech Connect

    Meng-Shiou Wu; Srinivas Aluru; Ricky A. Kendall

    2004-09-30

    In modern clustering environments where the memory hierarchy has many layers (distributed memory, shared memory layer, cache,...), an important question is how to fully utilize all available resources and identify the most dominant layer in certain computations. When combining algorithms on all layers together, what would be the best method to get the best performance out of all the resources we have? Mixed mode programming model that uses thread programming on the shared memory layer and message passing programming on the distributed memory layer is a method that many researchers are using to utilize the memory resources. In this paper, they take an algorithmic approach that uses matrix multiplication as a tool to show how cache algorithms affect the performance of both shared memory and distributed memory algorithms. They show that with good underlying cache algorithm, overall performance is stable. When underlying cache algorithm is bad, superlinear speedup may occur, and an increasing number of threads may also improve performance.

  8. Nation's water picture mixed

    NASA Astrophysics Data System (ADS)

    The nation's water picture for April showed mixed trends: More than half of the index gaging stations reported normal streamflow conditions during the month, while the spring snowmelt boosted streamflow in the Northeast and Northwest to well above normal levels. Parts of the Southeast, however, from West Virginia south to the Carolinas, reported well-below normal streamflow conditions, according to a month-end check on water resources conditions by the U.S. Geological Survey, Department of the Interior.After nearly 2 years of drought conditions the three major reservoirs supplying New York City reached full storage capacity and were spilling during April. Combined contents of the three reservoirs on May 1, 1982, was 272 billion gallons, 101% of their full usable capacity. The full reservoirs and the generally good surface and groundwater conditions throughout the Delaware River basin allowed the Delaware River Basin Commission to lift its drought emergency warning on April 27.

  9. Biogenic inputs to ocean mixing.

    PubMed

    Katija, Kakani

    2012-03-15

    Recent studies have evoked heated debate about whether biologically generated (or biogenic) fluid disturbances affect mixing in the ocean. Estimates of biogenic inputs have shown that their contribution to ocean mixing is of the same order as winds and tides. Although these estimates are intriguing, further study using theoretical, numerical and experimental techniques is required to obtain conclusive evidence of biogenic mixing in the ocean. Biogenic ocean mixing is a complex problem that requires detailed understanding of: (1) marine organism behavior and characteristics (i.e. swimming dynamics, abundance and migratory behavior), (2) mechanisms utilized by swimming animals that have the ability to mix stratified fluids (i.e. turbulence and fluid drift) and (3) knowledge of the physical environment to isolate contributions of marine organisms from other sources of mixing. In addition to summarizing prior work addressing the points above, observations on the effect of animal swimming mode and body morphology on biogenic fluid transport will also be presented. It is argued that to inform the debate on whether biogenic mixing can contribute to ocean mixing, our studies should focus on diel vertical migrators that traverse stratified waters of the upper pycnocline. Based on our understanding of mixing mechanisms, body morphologies, swimming modes and body orientation, combined with our knowledge of vertically migrating populations of animals, it is likely that copepods, krill and some species of gelatinous zooplankton and fish have the potential to be strong sources of biogenic mixing.

  10. Fluid mixing in stratified gravity currents: the Prandtl mixing length.

    PubMed

    Odier, P; Chen, J; Rivera, M K; Ecke, R E

    2009-04-03

    Shear-induced vertical mixing in a stratified flow is a key ingredient of thermohaline circulation. We experimentally determine the vertical flux of momentum and density of a forced gravity current using high-resolution velocity and density measurements. A constant eddy-viscosity model provides a poor description of the physics of mixing, but a Prandtl mixing length model relating momentum and density fluxes to mean velocity and density gradients works well. For the average gradient Richardson number Ri(g) approximately 0.08 and a Taylor Reynolds number Re(lambda) approximately 100, the mixing lengths are fairly constant, about the same magnitude, comparable to the turbulent shear length.

  11. Affective and schizoaffective mixed states.

    PubMed

    Marneros, Andreas; Röttig, Stephan; Wenzel, Andreas; Blöink, Raffaela; Brieger, Peter

    2004-04-01

    Although both DSM-IV and ICD-10 define schizoaffective mixed states, they have not received much attention-neither in the clinical nor in research context. We present preliminary results of a prospective study of bipolar affective (n = 100) and bipolar schizoaffective (n = 177) patients. 25% of the bipolar affective and 32% of the bipolar schizoaffective patients had at least one (schizo)mixed episode during the illness course. Nevertheless, (schizo)mixed episodes were rare-only 5.6% of all episodes. There was a trend that patients with (schizo)mixed episodes were more often women and exhibited more disability (reflected by higher rates of disability payments). Nevertheless, these differences failed to reach significance. Overall, schizo-mixed episodes are as frequent as "pure" affective mixed episodes. They might be linked to a less favourable course. Nevertheless, while their diagnostic criteria are problematic, they are systematically underdiagnosed.

  12. Authoring Immersive Mixed Reality Experiences

    NASA Astrophysics Data System (ADS)

    Misker, Jan M. V.; van der Ster, Jelle

    Creating a mixed reality experience is a complicated endeavour. From our practice as a media lab in the artistic domain we found that engineering is “only” a first step in creating a mixed reality experience. Designing the appearance and directing the user experience are equally important for creating an engaging, immersive experience. We found that mixed reality artworks provide a very good test bed for studying these topics. This chapter details three steps required for authoring mixed reality experiences: engineering, designing and directing. We will describe a platform (VGE) for creating mixed reality environments that incorporates these steps. A case study (EI4) is presented in which this platform was used to not only engineer the system, but in which an artist was given the freedom to explore the artistic merits of mixed reality as an artistic medium, which involved areas such as the look and feel, multimodal experience and interaction, immersion as a subjective emotion and game play scenarios.

  13. Estimating beta-mixing coefficients

    PubMed Central

    McDonald, Daniel J.; Shalizi, Cosma Rohilla; Schervish, Mark

    2015-01-01

    The literature on statistical learning for time series assumes the asymptotic independence or “mixing” of the data-generating process. These mixing assumptions are never tested, and there are no methods for estimating mixing rates from data. We give an estimator for the beta-mixing rate based on a single stationary sample path and show it is L1-risk consistent. PMID:26279742

  14. Optimal broadcasting of mixed states

    SciTech Connect

    Dang Guifang; Fan Heng

    2007-08-15

    The N to M (M{>=}N) universal quantum broadcasting of mixed states {rho}{sup xN} is proposed for a qubit system. The broadcasting of mixed states is universal and optimal in the sense that the shrinking factor is independent of the input state and achieves the upper bound. The quantum broadcasting of mixed qubits is a generalization of the universal quantum cloning machine for identical pure input states. A pure state decomposition of the identical mixed qubits {rho}{sup xN} is obtained.

  15. Overview of Neutrino Mixing Models and Their Mixing Angle Predictions

    SciTech Connect

    Albright, Carl H.

    2009-11-01

    An overview of neutrino-mixing models is presented with emphasis on the types of horizontal flavor and vertical family symmetries that have been invoked. Distributions for the mixing angles of many models are displayed. Ways to differentiate among the models and to narrow the list of viable models are discussed.

  16. Mixed voltage VLSI design

    NASA Technical Reports Server (NTRS)

    Panwar, Ramesh; Rennels, David; Alkalaj, Leon

    1993-01-01

    A technique for minimizing the power dissipated in a Very Large Scale Integration (VLSI) chip by lowering the operating voltage without any significant penalty in the chip throughput even though low voltage operation results in slower circuits. Since the overall throughput of a VLSI chip depends on the speed of the critical path(s) in the chip, it may be possible to sustain the throughput rates attained at higher voltages by operating the circuits in the critical path(s) with a high voltage while operating the other circuits with a lower voltage to minimize the power dissipation. The interface between the gates which operate at different voltages is crucial for low power dissipation since the interface may possibly have high static current dissipation thus negating the gains of the low voltage operation. The design of a voltage level translator which does the interface between the low voltage and high voltage circuits without any significant static dissipation is presented. Then, the results of the mixed voltage design using a greedy algorithm on three chips for various operating voltages are presented.

  17. Mixed cryoglobulinemia: new concepts.

    PubMed

    Ramos-Casals, M; Trejo, O; García-Carrasco, M; Cervera, R; Font, J

    2000-01-01

    The most documented extrahepatic manifestation of hepatitis C virus (HCV) infection is mixed cryoglobulinemia (MC). MC is characterised by the presence of temperature-sensitive protein complexes: in type II MC, cryoglobulins are composed of a monoclonal rheumatoid factor (usually, IgMkappa) against polyclonal IgG. In type III MC, all components are polyclonal. The presence of microheterogeneity and other new types of cryoglobulins is a novel and recent observation. The production of different autoantibodies and circulating immune complexes, including the cryoglobulins, are responsible for systemic vasculitis and various organ damage. In a limited number of MC patients, a malignancy, that is B-cell non-Hodgkin's lymphoma or hepatocellular carcinoma, may also develop. Finally, results of interferon and/or ribavirin treatments in MC patients represent an indirect proof for the pathogenetic link between MC and HVC infection. The discovery of the relation between HCV infection and MC shows the striking association between a viral infection and an autoimmune disease and, thus, a potential link between the systemic autoimmune and lymphoproliferative disorders.

  18. Measures on mixing angles

    SciTech Connect

    Gibbons, Gary W.; Gielen, Steffen; Pope, C. N.; Turok, Neil

    2009-01-01

    We address the problem of the apparently very small magnitude of CP violation in the standard model, measured by the Jarlskog invariant J. In order to make statements about probabilities for certain values of J, we seek to find a natural measure on the space of Kobayashi-Maskawa matrices, the double quotient U(1){sup 2}/SU(3)/U(1){sup 2}. We review several possible, geometrically motivated choices of the measure, and compute expectation values for powers of J for these measures. We find that different choices of the measure generically make the observed magnitude of CP violation appear finely tuned. Since the quark masses and the mixing angles are determined by the same set of Yukawa couplings, we then do a second calculation in which we take the known quark mass hierarchy into account. We construct the simplest measure on the space of 3x3 Hermitian matrices which reproduces this known hierarchy. Calculating expectation values for powers of J in this second approach, we find that values of J close to the observed value are now rather likely, and there does not seem to be any fine-tuning. Our results suggest that the choice of Kobayashi-Maskawa angles is closely linked to the observed mass hierarchy. We close by discussing the corresponding case of neutrinos.

  19. Neutrino Masses and Mixing

    SciTech Connect

    Ishikawa, K.; Tobita, Y.

    2008-05-21

    We report (1) the current status of neutrino parameters and (2) our recent work on implications of particle's coherence, which are weakly related each others. In the first part, current status of the neutrino parameters obtained from oscillation experiments and their prospects are briefly reviewed. From various oscillation experiments, existence of three mass scales have been confirmed. One value of the difference of mass squared is around 10{sup -3}eV{sup 2} and another is around 10{sup -5}eV{sup 2}. Although mixing angles are partly found, one important angle, {theta}{sub 13} is left unknown.In the second part, implications of coherence length of particles in the scattering of ultra-high energy cosmic rays (UHCR) with cosmic background radiations (CBR) is discussed. Although coherence length is regarded usually irrelevant to observations, its role is important in several situations of recent experiments which include that of the ultra-high energy charged particles. Here we discuss the scattering of UHCR with CBR.

  20. Postictal mixed transcortical aphasia.

    PubMed

    Yankovsky, A E; Treves, T A

    2002-06-01

    Postictal aphasia has been described in left temporal lobe seizures. It may be of fluent, non-fluent or global type. We present here a patient who displayed signs of mixed transcortical aphasia (MTCA). The patient was a 67 year old man who underwent excision of a left frontal parasagittal meningioma in 1987. Since then he has been treated with phenytoin for generalized tonic-clonic seizures (GTCS). He was admitted in status epilepticus. On awakening, the patient was non-fluent with palilalia and echolalia. His repetition was relatively preserved but all the other language functions were impaired. This picture faded away within a few hours. Brain CT, performed during this postictal state, was normal except for signs related to frontal craniotomy. SPECT, which was performed after language functions returned to normal, displayed left frontal, cingular and insular hypoperfusion. The postictal language dysfunction of the patient corresponded to MTCA. Although our case has frontal, he had no other structural lesion that could explain either diffuse ischemia of the left hemisphere or watershed areas secondary to the generalized seizures. The uniqueness of this case is the combination of postictal MTCA with good prognosis. Copyright 2002 BEA Trading Ltd. Published by Elsevier Science Ltd. All rights reserved.

  1. Mixed oxide fuel development

    SciTech Connect

    Leggett, R.D.; Omberg, R.P.

    1987-05-08

    This paper describes the success of the ongoing mixed-oxide fuel development program in the United States aimed at qualifying an economical fuel system for liquid metal cooled reactors. This development has been the cornerstone of the US program for the past 20 years and has proceeded in a deliberate and highly disciplined fashion with high emphasis on fuel reliability and operational safety as major features of an economical fuel system. The program progresses from feature testing in EBR-II to qualifying full size components in FFTF under fully prototypic conditions to establish a basis for extending allowable lifetimes. The development program started with the one year (300 EFPD) core, which is the FFTF driver fuel, continued with the demonstration of a two year (600 EFPD) core and is presently evaluating a three year (900 EFPD) fuel system. All three of these systems, consistent with other LMR fuel programs around the world, use fuel pellets gas bonded to a cladding tube that is assembled into a bundle and fitted into a wrapper tube or duct for ease of insertion into a core. The materials of construction progressed from austenitic CW 316 SS to lower swelling austenitic D9 to non swelling ferritic/martensitic HT9. 6 figs., 2 tabs.

  2. Mixing in polymeric microfluidic devices.

    SciTech Connect

    Schunk, Peter Randall; Sun, Amy Cha-Tien; Davis, Robert H.; Brotherton, Christopher M. (University of Colorado at Boulder, Boulder, CO)

    2006-04-01

    This SAND report describes progress made during a Sandia National Laboratories sponsored graduate fellowship. The fellowship was funded through an LDRD proposal. The goal of this project is development and characterization of mixing strategies for polymeric microfluidic devices. The mixing strategies under investigation include electroosmotic flow focusing, hydrodynamic focusing, physical constrictions and porous polymer monoliths. For electroosmotic flow focusing, simulations were performed to determine the effect of electroosmotic flow in a microchannel with heterogeneous surface potential. The heterogeneous surface potential caused recirculations to form within the microchannel. These recirculations could then be used to restrict two mixing streams and reduce the characteristic diffusion length. Maximum mixing occurred when the ratio of the mixing region surface potential to the average channel surface potential was made large in magnitude and negative in sign, and when the ratio of the characteristic convection time to the characteristic diffusion time was minimized. Based on these results, experiments were performed to evaluate the manipulation of surface potential using living-radical photopolymerization. The material chosen to manipulate typically exhibits a negative surface potential. Using living-radical surface grafting, a positive surface potential was produced using 2-(Dimethylamino)ethyl methacrylate and a neutral surface was produced using a poly(ethylene glycol) surface graft. Simulations investigating hydrodynamic focusing were also performed. For this technique, mixing is enhanced by using a tertiary fluid stream to constrict the two mixing streams and reduce the characteristic diffusion length. Maximum mixing occurred when the ratio of the tertiary flow stream flow-rate to the mixing streams flow-rate was maximized. Also, like the electroosmotic focusing mixer, mixing was also maximized when the ratio of the characteristic convection time to the

  3. Anomalous Sediment Mixing by Bioturbation

    NASA Astrophysics Data System (ADS)

    Roche, K. R.; Aubeneau, A. F.; Xie, M.; Packman, A. I.

    2013-12-01

    Bioturbation, the reworking of sediments by animals and plants, is the dominant mode of sediment mixing in low-energy environments, and plays an important role in sedimentary biogeochemical processes. Mixing resulting from bioturbation has historically been modeled as a diffusive process. However, diffusion models often do not provide a sufficient description of sediment mixing due to bioturbation. Stochastic models, such as the continuous time random walk (CTRW) model, provide more general descriptions of mixing behavior that are applicable even when regular diffusion assumptions are not met. Here we present results from an experimental investigation of anomalous sediment mixing by bioturbation in freshwater sediments. Clean and heavy-metal-contaminated sediments were collected from Lake DePue, a backwater lake of the Illinois River. The burrowing worm species Lumbriculus variegatus was introduced to homogenized Lake DePue sediments in aerated aquaria. We then introduced inert fine fluorescent particles to the sediment-water interface. Using time-lapse photography, we observed the mixing of the fluorescent particles into the sediment bed over a two-week period. We developed image analysis software to characterize the concentration distribution of the fluorescent particles as a function of sediment depth, and applied this to the time-series of images to evaluate sediment mixing. We fit a one-dimensional CTRW model to the depth profiles to evaluate the underlying statistical properties of the mixing behavior. This analysis suggests that the sediment mixing caused by L. variegatus burrowing is subdiffusive in time and superdiffusive in space. We also found that heavy metal contamination significantly reduces L. variegatus burrowing, causing increasingly anomalous sediment mixing. This result implies that there can be important feedbacks between sediment chemistry, organism behavior, and sediment mixing that are not considered in current environmental models.

  4. Microfluidic mixing using contactless dielectrophoresis.

    PubMed

    Salmanzadeh, Alireza; Shafiee, Hadi; Davalos, Rafael V; Stremler, Mark A

    2011-09-01

    The first experimental evidence of mixing enhancement in a microfluidic system using contactless dielectrophoresis (cDEP) is presented in this work. Pressure-driven flow of deionized water containing 0.5 μm beads was mixed in various chamber geometries by imposing a dielectrophoresis (DEP) force on the beads. In cDEP the electrodes are not in direct contact with the fluid sample but are instead capacitively coupled to the mixing chamber through thin dielectric barriers, which eliminates many of the problems encountered with standard DEP. Four system designs with rectangular and circular mixing chambers were fabricated in PDMS. Mixing tests were conducted for flow rates from 0.005 to 1 mL/h subject to an alternating current signal range of 0-300 V at 100-600 kHz. When the time scales of the bulk fluid motion and the DEP motion were commensurate, rapid mixing was observed. The rectangular mixing chambers were found to be more efficient than the circular chambers. This approach shows potential for mixing low diffusivity biological samples, which is a very challenging problem in laminar flows at small scales.

  5. Iowa City Ready Mix, Inc.

    EPA Pesticide Factsheets

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Iowa City Ready Mix, Inc., for alleged violations at a facility located at 1854 South Riverside, Iowa City, IA (“facility”). The facility produces and transports ready mixe

  6. Mixed Waste Working Group report

    SciTech Connect

    Not Available

    1993-11-09

    The treatment of mixed waste remains one of this country`s most vexing environmental problems. Mixed waste is the combination of radioactive waste and hazardous waste, as defined by the Resource Conservation and Recovery Act (RCRA). The Department of Energy (DOE), as the country`s largest mixed waste generator, responsible for 95 percent of the Nation`s mixed waste volume, is now required to address a strict set of milestones under the Federal Facility Compliance Act of 1992. DOE`s earlier failure to adequately address the storage and treatment issues associated with mixed waste has led to a significant backlog of temporarily stored waste, significant quantities of buried waste, limited permanent disposal options, and inadequate treatment solutions. Between May and November of 1993, the Mixed Waste Working Group brought together stakeholders from around the Nation. Scientists, citizens, entrepreneurs, and bureaucrats convened in a series of forums to chart a course for accelerated testing of innovative mixed waste technologies. For the first time, a wide range of stakeholders were asked to examine new technologies that, if given the chance to be tested and evaluated, offer the prospect for better, safer, cheaper, and faster solutions to the mixed waste problem. In a matter of months, the Working Group has managed to bridge a gap between science and perception, engineer and citizen, and has developed a shared program for testing new technologies.

  7. Mixed-Methods Research Methodologies

    ERIC Educational Resources Information Center

    Terrell, Steven R.

    2012-01-01

    Mixed-Method studies have emerged from the paradigm wars between qualitative and quantitative research approaches to become a widely used mode of inquiry. Depending on choices made across four dimensions, mixed-methods can provide an investigator with many design choices which involve a range of sequential and concurrent strategies. Defining…

  8. Mixed connective tissue disease.

    PubMed

    Gunnarsson, Ragnar; Hetlevik, Siri Opsahl; Lilleby, Vibke; Molberg, Øyvind

    2016-02-01

    The concept of mixed connective tissue disease (MCTD) as a separate connective tissue disease (CTD) has persisted for more than four decades. High titers of antibodies targeting the U1 small nuclear ribonucleoprotein particle (U1 snRNP) in peripheral blood are a sine qua non for the diagnosis of MCTD, in addition to distinct clinical features including Raynaud's phenomenon (RP), "puffy hands," arthritis, myositis, pleuritis, pericarditis, interstitial lung disease (ILD), and pulmonary hypertension (PH). Recently, population-based epidemiology data from Norway estimated the point prevalence of adult-onset MCTD to be 3.8 per 100,000 and the mean annual incidence to be 2.1 per million per year, supporting the notion that MCTD is the least common CTD. Little is known about the etiology of MCTD, but recent genetic studies have confirmed that MCTD is a strongly HLA (​human leukocyte antigen)-linked disease, as the HLA profiles of MCTD differ distinctly from the corresponding profiles of ethnically matched healthy controls and other CTDs. In the first section of this review, we provide an update on the clinical, immunological, and genetic features of MCTD and discuss the relationship between MCTD and the other CTDs. Then we proceed to discuss the recent advances in therapy and our current understanding of prognosis and prognostic factors, especially those that are associated with the more serious pulmonary and cardiovascular complications of the disease. In the final section, we discuss some of the key, unresolved questions related to anti-RNP-associated diseases and indicate how these questions may be approached in future studies.

  9. Biomass conversion to mixed alcohols

    SciTech Connect

    Holtzapple, M.T.; Loescher, M.; Ross, M.

    1996-10-01

    This paper discusses the MixAlco Process which converts a wide variety of biomass materials (e.g. municipal solid waste, sewage sludge, agricultural residues) to mixed alcohols. First, the biomass is treated with lime to enhance its digestibility. Then, a mixed culture of acid-forming microorganisms converts the lime-treated biomass to volatile fatty acids (VFA) such as acetic, propionic, and butyric acids. To maintain fermentor pH, a neutralizing agent (e.g. calcium carbonate or lime) is added, so the fermentation actually produces VFA salts such as calcium acetate, propionate, and butyrate. The VFA salts are recovered and thermally converted to ketones (e.g. acetone, methylethyl ketone, diethyl ketone) which are subsequently hydrogenated to mixed alcohols (e.g. isopropanol, isobutanol, isopentanol). Processing costs are estimated at $0.72/gallon of mixed alcohols making it potentially attractive for transportation fuels.

  10. CHARACTERIZING PULSATING MIXING OF SLURRIES

    SciTech Connect

    Bamberger, Judith A.; Meyer, Perry A.

    2007-12-01

    This paper describes the physical properties for defining the operation of a pulse jet mixing system. Pulse jet mixing operates with no moving parts located in the vessel to be mixed. Pulse tubes submerged in the vessel provide a pulsating flow due to a controlled combination of applied pressure to expel the fluid from the pulse tube nozzle followed by suction to refill the pulse tube through the same nozzle. For mixing slurries nondimensional parameters to define mixing operation include slurry properties, geometric properties and operational parameters. Primary parameters include jet Reynolds number and Froude number; alternate parameters may include particle Galileo number, particle Reynolds number, settling velocity ratio, and hindered settling velocity ratio. Rating metrics for system performance include just suspended velocity, concentration distribution as a function of elevation, and blend time.

  11. Mixing in confined stratified aquifers

    NASA Astrophysics Data System (ADS)

    Bolster, Diogo; Valdés-Parada, Francisco J.; LeBorgne, Tanguy; Dentz, Marco; Carrera, Jesus

    2011-03-01

    Spatial variability in a flow field leads to spreading of a tracer plume. The effect of microdispersion is to smooth concentration gradients that exist in the system. The combined effect of these two phenomena leads to an 'effective' enhanced mixing that can be asymptotically quantified by an effective dispersion coefficient (i.e. Taylor dispersion). Mixing plays a fundamental role in driving chemical reactions. However, at pre-asymptotic times it is considerably more difficult to accurately quantify these effects by an effective dispersion coefficient as spreading and mixing are not the same (but intricately related). In this work we use a volume averaging approach to calculate the concentration distribution of an inert solute release at pre-asymptotic times in a stratified formation. Mixing here is characterized by the scalar dissipation rate, which measures the destruction of concentration variance. As such it is an indicator for the degree of mixing of a system. We study pre-asymptotic solute mixing in terms of explicit analytical expressions for the scalar dissipation rate and numerical random walk simulations. In particular, we divide the concentration field into a mean and deviation component and use dominant balance arguments to write approximate governing equations for each, which we then solve analytically. This allows us to explicitly evaluate the separate contributions to mixing from the mean and the deviation behavior. We find an approximate, but accurate expression (when compared to numerical simulations) to evaluate mixing. Our results shed some new light on the mechanisms that lead to large scale mixing and allow for a distinction between solute spreading, represented by the mean concentration, and mixing, which comes from both the mean and deviation concentrations, at pre-asymptotic times.

  12. Baroclinic mixing in HE fireballs

    SciTech Connect

    Kuhl, A.L.; Ferguson, R.E.; Priolo, F.; Chien, K.Y.; Collins, J.P.

    1993-08-01

    Numerical simulations of the turbulent mixing in the fireball of an HE blast wave were performed with a second-order Godunov code. Adaptive mesh refinement was used to capture the convective mixing processes on the computational grid. The calculations revealed that the interface between the shock-compressed air and the dense detonation products was unstable. Vorticity was generated in that region by baroclinic effects. This caused the interface to roll-up into a turbulent mixing layer. Four phases of mixing were identified: a strong blast wave phase, where the mixing region was swept outward by the shockinduced flow; an implosion phase, that stretched the inner boundary of the mixing region back toward the origin; a re-shocking phase, where the imploding shock expands back outward from the origin and re-energizes the mixing later by RichtmyerMeshkov effects; and an asymptotic mixing phase, where line-scale structures are continually recreated by folding effects but the overall vorticity decays through a cascade process. The flowfield was azimuthally averaged to evaluate the mean-flow profiles and r.m.s. fluctuation profiles across the mixing layer. The mean kinetic energy rapidly approached zero as the blast wave decayed, but the fluctuating kinetic energy asymptotically approached a small constant value. This represents the rotational kinetic energy driven by the vorticity field, that continued to mix the fluid at late times. It was shown that the vorticity field corresponds to a function that fluctuates between plus and minus values-with a volume-averaged mean of zero.

  13. Turbidity Current Head Mixing

    NASA Astrophysics Data System (ADS)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    coastal diffusion using image analysis. Applied Scientific Research 59,.191-204. 1998. [5] J.M. Redondo. Turbulent mixing in the Atmosphere and Ocean. Fluid Physics. 584-597. World Scientific. New York. 1994

  14. Compressibility effects on turbulent mixing

    NASA Astrophysics Data System (ADS)

    Panickacheril John, John; Donzis, Diego

    2016-11-01

    We investigate the effect of compressibility on passive scalar mixing in isotropic turbulence with a focus on the fundamental mechanisms that are responsible for such effects using a large Direct Numerical Simulation (DNS) database. The database includes simulations with Taylor Reynolds number (Rλ) up to 100, turbulent Mach number (Mt) between 0.1 and 0.6 and Schmidt number (Sc) from 0.5 to 1.0. We present several measures of mixing efficiency on different canonical flows to robustly identify compressibility effects. We found that, like shear layers, mixing is reduced as Mach number increases. However, data also reveal a non-monotonic trend with Mt. To assess directly the effect of dilatational motions we also present results with both dilatational and soleniodal forcing. Analysis suggests that a small fraction of dilatational forcing decreases mixing time at higher Mt. Scalar spectra collapse when normalized by Batchelor variables which suggests that a compressive mechanism similar to Batchelor mixing in incompressible flows might be responsible for better mixing at high Mt and with dilatational forcing compared to pure solenoidal mixing. We also present results on scalar budgets, in particular on production and dissipation. Support from NSF is gratefully acknowledged.

  15. Langmuir Mixing Affects Global Climate

    NASA Astrophysics Data System (ADS)

    Li, Q.; Webb, A.; Fox-Kemper, B.; Arbetter, T. E.; Craig, A.; Danabasoglu, G.; Large, W.; Vertenstein, M.

    2016-02-01

    The effects of Langmuir turbulence on the surface ocean mixing and thereby the global climate are assessed in the CESM earth system model by adding a parameterization of Langmuir mixing to the K-Profile Parameterization (KPP). A global wave field is needed by this Langmuir mixing parameterization to provide the Stokes drift that drives Langmuir mixing. Both a prognostic wave model, WAVEWATCH III, and a climatological data wave model have been coupled with CESM and tested. Nearly identical and substantial improvements in the simulated mixed layer depth and intermediate water ventilation are found in both cases when Langmuir mixing is included. The greatest improvement occurs in the Southern Ocean. A climatological data wave model, which responds to simulated winds, but with fixed wind-wave relationships, can therefore reproduce the primary improvements of Langmuir mixing, but with much less computational cost than even a coarse-resolution prognostic wave model. Progress toward an improved wave-induced entrainment through the bottom of ocean surface boundary layer will also be discussed.

  16. Mixed features in bipolar disorder.

    PubMed

    Solé, Eva; Garriga, Marina; Valentí, Marc; Vieta, Eduard

    2016-12-29

    Mixed affective states, defined as the coexistence of depressive and manic symptoms, are complex presentations of manic-depressive illness that represent a challenge for clinicians at the levels of diagnosis, classification, and pharmacological treatment. The evidence shows that patients with bipolar disorder who have manic/hypomanic or depressive episodes with mixed features tend to have a more severe form of bipolar disorder along with a worse course of illness and higher rates of comorbid conditions than those with non-mixed presentations. In the updated Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5), the definition of "mixed episode" has been removed, and subthreshold nonoverlapping symptoms of the opposite pole are captured using a "with mixed features" specifier applied to manic, hypomanic, and major depressive episodes. However, the list of symptoms proposed in the DSM-5 specifier has been widely criticized, because it includes typical manic symptoms (such as elevated mood and grandiosity) that are rare among patients with mixed depression, while excluding symptoms (such as irritability, psychomotor agitation, and distractibility) that are frequently reported in these patients. With the new classification, mixed depressive episodes are three times more common in bipolar II compared with unipolar depression, which partly contributes to the increased risk of suicide observed in bipolar depression compared to unipolar depression. Therefore, a specific diagnostic category would imply an increased diagnostic sensitivity, would help to foster early identification of symptoms and ensure specific treatment, as well as play a role in suicide prevention in this population.

  17. Mapping the Mixed Methods–Mixed Research Synthesis Terrain

    PubMed Central

    Sandelowski, Margarete; Voils, Corrine I.; Leeman, Jennifer; Crandell, Jamie L.

    2012-01-01

    Mixed methods–mixed research synthesis is a form of systematic review in which the findings of qualitative and quantitative studies are integrated via qualitative and/or quantitative methods. Although methodological advances have been made, efforts to differentiate research synthesis methods have been too focused on methods and not focused enough on the defining logics of research synthesis—each of which may be operationalized in different ways—or on the research findings themselves that are targeted for synthesis. The conduct of mixed methods–mixed research synthesis studies may more usefully be understood in terms of the logics of aggregation and configuration. Neither logic is preferable to the other nor tied exclusively to any one method or to any one side of the qualitative/quantitative binary. PMID:23066379

  18. [Marketing mix in health service].

    PubMed

    Ameri, Cinzia; Fiorini, Fulvio

    2015-01-01

    The marketing mix is the combination of the marketing variables that a firm employs with the purpose to achieve the expected volume of business within its market. In the sale of goods, four variables compose the marketing mix (4 Ps): Product, Price, Point of sale and Promotion. In the case of providing services, three further elements play a role: Personnel, Physical Evidence and Processes (7 Ps). The marketing mix must be addressed to the consumers as well as to the employees of the providing firm. Furthermore, it must be interpreted as employees ability to satisfy customers (interactive marketing).

  19. Waveguide Four-Wave Mixing

    DTIC Science & Technology

    1991-10-01

    PL-TR--91-1045 /’--"PL-TR-- AD-A243 555 91-1045 WAVEGUIDE FOUR -WAVE MIXING Thomas B. Simpson Jia-ming Liu JAYCOR San Diego, CA 92186-5154 October...Final Report; May 88 - Mar 91 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS WAVEGUIDE FOUR -WAVE MIXING C: F29601-88-C-0023 PE: 62601F PR: 3326 6. AUTHOR(S...for public release; distribution unlimited. 13. ABSTRACT (Maximum 200 words) This program has investigated four -wave mixing (4-win) in non- linear

  20. Mixed deterministic and probabilistic networks

    PubMed Central

    Dechter, Rina

    2010-01-01

    The paper introduces mixed networks, a new graphical model framework for expressing and reasoning with probabilistic and deterministic information. The motivation to develop mixed networks stems from the desire to fully exploit the deterministic information (constraints) that is often present in graphical models. Several concepts and algorithms specific to belief networks and constraint networks are combined, achieving computational efficiency, semantic coherence and user-interface convenience. We define the semantics and graphical representation of mixed networks, and discuss the two main types of algorithms for processing them: inference-based and search-based. A preliminary experimental evaluation shows the benefits of the new model. PMID:20981243

  1. Biodegradation of mixed pesticides by mixed pesticide enriched cultures.

    PubMed

    Krishna, K Rama; Philip, Ligy

    2009-01-01

    This paper discusses the degradation kinetics of mixed (lindane, methyl parathion and carbofuran) pesticides by mixed pesticide enriched cultures (MEC) under various environmental conditions. The bacterial strains isolated from the mixed microbial consortium were identified as Pseudomonas aeruginosa (MTCC 9236), Bacillus sp. (MTCC 9235) and Chryseobacterium joostei (MTCC 9237). Batch studies were conducted to estimate the biokinetic parameters like the maximum specific growth rate (mu(max)), Yield Coefficient (Y(T)), half saturation concentration (K(s)) and inhibition concentration (Ki) for individual and mixed pesticide enriched cultures. The cultures enriched in a particular pollutant always showed high growth rate and low inhibition in that particular pollutant compared to MEC. After seven weeks of incubation, mixed pesticide enriched cultures were able to degrade 72% lindane, 95% carbofuran and 100% of methyl parathion in facultative co-metabolic conditions. In aerobic systems, degradation efficiencies of lindane methyl parathion and carbofuran were increased by the addition of 2g L(- 1) of dextrose. Though many metabolic compounds of mixed pesticides were observed at different time intervals, none of the metabolites were persistent. Based on the observed metabolites, a degradation pathway was postulated for different pesticides under various environmental conditions.

  2. Modeling Mix in ICF Implosions

    NASA Astrophysics Data System (ADS)

    Weber, C. R.; Clark, D. S.; Chang, B.; Eder, D. C.; Haan, S. W.; Jones, O. S.; Marinak, M. M.; Peterson, J. L.; Robey, H. F.

    2014-10-01

    The observation of ablator material mixing into the hot spot of ICF implosions correlates with reduced yield in National Ignition Campaign (NIC) experiments. Higher Z ablator material radiatively cools the central hot spot, inhibiting thermonuclear burn. This talk focuses on modeling a ``high-mix'' implosion from the NIC, where greater than 1000 ng of ablator material was inferred to have mixed into the hot spot. Standard post-shot modeling of this implosion does not predict the large amounts of ablator mix necessary to explain the data. Other issues are explored in this talk and sensitivity to the method of radiation transport is found. Compared with radiation diffusion, Sn transport can increase ablation front growth and alter the blow-off dynamics of capsule dust. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  3. Mixed-mu superconducting bearings

    DOEpatents

    Hull, J.R.; Mulcahy, T.M.

    1998-03-03

    A mixed-mu superconducting bearing is disclosed including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure. 9 figs.

  4. Is the tribimaximal mixing accidental?

    SciTech Connect

    Abbas, Mohammed; Smirnov, A. Yu.

    2010-07-01

    The tribimaximal (TBM) mixing is not accidental if structures of the corresponding leptonic mass matrices follow immediately from certain (residual or broken) flavor symmetry. We develop a simple formalism which allows one to analyze effects of deviations of the lepton mixing from TBM on the structure of the neutrino mass matrix and on the underlying flavor symmetry. We show that possible deviations from the TBM mixing can lead to strong modifications of the mass matrix and strong violation of the TBM-mass relations. As a result, the mass matrix may have an 'anarchical' structure with random values of elements or it may have some symmetry that differs from the TBM symmetry. Interesting examples include matrices with texture zeros, matrices with certain 'flavor alignment' as well as hierarchical matrices with a two-component structure, where the dominant and subdominant contributions have different symmetries. This opens up new approaches to understanding the lepton mixing.

  5. Mixed-mu superconducting bearings

    DOEpatents

    Hull, John R.; Mulcahy, Thomas M.

    1998-01-01

    A mixed-mu superconducting bearing including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure.

  6. Cutaneous mixed infections in AIDS.

    PubMed

    Piérard, G E; Piérard-Franchimont, C; Estrada, J A; Rurangirwa, A; Dosal, F L

    1990-02-01

    We report a new case of mixed infection occurring at the same site of the skin in a human immune deficiency virus-positive patient. Hyperkeratotic and crusted erosions contained fusospirochetal organisms, Cryptococcus neoformans, and another unidentified fungus.

  7. Barium Stars and Thermohaline Mixing

    SciTech Connect

    Husti, Laura

    2008-01-24

    Barium stars are formed in binary systems through mass transfer from the carbon and s-element rich primary in the AGB phase, to the secondary star which is in a less evolved evolutionary stage. The mixing of the accreted material from the AGB donor with the envelope of the secondary results in a dilution of the s-element abundances. Dilution in red giants is explained by the occurence of the first dredge up, while in case of dwarfs thermohaline mixing would determine it. A comparison between the theoretical predictions of the AGB stellar models and the spectroscopical observations of a large sample of barium stars has been made. Dilution due to thermohaline mixing was taken into account when searching for best fits of the observational data. The importance of thermohaline mixing in barium dwarfs is discussed.

  8. Mixed jamming method for SAR

    NASA Astrophysics Data System (ADS)

    Zhao, Hong-feng; Zhang, Peng; Wang, Yong-sheng

    2007-11-01

    The mixed jamming method of synthetic aperture radar is analyzed and discussed. The methods of active noise and deception jamming and the signal model of transmitting is described. The raw echo signal of SAR and the model of jammed echo signal are expatiated, the characteristic of SAR and the evaluating method of jamming effect are established. Finally, the mixed jamming imaging of SAR is simulated.

  9. Perspectives on dilution jet mixing

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1986-01-01

    A microcomputer code which displays 3-D oblique and 2-D plots of the temperature distribution downstream of jets mixing with a confined crossflow has been used to investigate the effects of varying the several independent flow and geometric parameters on the mixing. Temperature profiles calculated with this empirical model are presented to show the effects of orifice size and spacing, momentum flux ratio, density ratio, variable temperature mainstream, flow area convergence, orifice aspect ratio, and opposed and axially staged rows of jets.

  10. Mixing of discontinuously deforming media.

    PubMed

    Smith, L D; Rudman, M; Lester, D R; Metcalfe, G

    2016-02-01

    Mixing of materials is fundamental to many natural phenomena and engineering applications. The presence of discontinuous deformations-such as shear banding or wall slip-creates new mechanisms for mixing and transport beyond those predicted by classical dynamical systems theory. Here, we show how a novel mixing mechanism combining stretching with cutting and shuffling yields exponential mixing rates, quantified by a positive Lyapunov exponent, an impossibility for systems with cutting and shuffling alone or bounded systems with stretching alone, and demonstrate it in a fluid flow. While dynamical systems theory provides a framework for understanding mixing in smoothly deforming media, a theory of discontinuous mixing is yet to be fully developed. New methods are needed to systematize, explain, and extrapolate measurements on systems with discontinuous deformations. Here, we investigate "webs" of Lagrangian discontinuities and show that they provide a template for the overall transport dynamics. Considering slip deformations as the asymptotic limit of increasingly localised smooth shear, we also demonstrate exactly how some of the new structures introduced by discontinuous deformations are analogous to structures in smoothly deforming systems.

  11. Quantifying mixing using equilibrium reactions

    NASA Astrophysics Data System (ADS)

    Wheat, Philip M.; Posner, Jonathan D.

    2009-03-01

    A method of quantifying equilibrium reactions in a microchannel using a fluorometric reaction of Fluo-4 and Ca2+ ions is presented. Under the proper conditions, equilibrium reactions can be used to quantify fluid mixing without the challenges associated with constituent mixing measures such as limited imaging spatial resolution and viewing angle coupled with three-dimensional structure. Quantitative measurements of CaCl and calcium-indicating fluorescent dye Fluo-4 mixing are measured in Y-shaped microchannels. Reactant and product concentration distributions are modeled using Green's function solutions and a numerical solution to the advection-diffusion equation. Equilibrium reactions provide for an unambiguous, quantitative measure of mixing when the reactant concentrations are greater than 100 times their dissociation constant and the diffusivities are equal. At lower concentrations and for dissimilar diffusivities, the area averaged fluorescence signal reaches a maximum before the species have interdiffused, suggesting that reactant concentrations and diffusivities must be carefully selected to provide unambiguous, quantitative mixing measures. Fluorometric equilibrium reactions work over a wide range of pH and background concentrations such that they can be used for a wide variety of fluid mixing measures including industrial or microscale flows.

  12. Mixed-dimensional Bose polaron

    NASA Astrophysics Data System (ADS)

    Loft, Niels Jakob Søe; Wu, Zhigang; Bruun, G. M.

    2017-09-01

    A new generation of cold atom experiments trapping atomic mixtures in species-selective optical potentials opens up the intriguing possibility to create systems in which different atoms live in different spatial dimensions. Inspired by this, we investigate a mixed-dimensional Bose polaron consisting of an impurity particle moving in a two-dimensional (2D) layer immersed in a 3D Bose-Einstein condensate (BEC), using a theory that includes the mixed-dimensional vacuum scattering between the impurity and the bosons exactly. We show that similarly to the pure 3D case, this system exhibits a well-defined polaron state for attractive boson-impurity interaction that evolves smoothly into a mixed-dimensional dimer for strong attraction, as well as a well-defined polaron state for weak repulsive interaction, which becomes overdamped for strong interaction. We furthermore find that the properties of the polaron depend only weakly on the gas parameter of the BEC as long as the Bogoliubov theory remains a valid description for the BEC. This indicates that higher-order correlations between the impurity and the bosons are suppressed by the mixed-dimensional geometry in comparison to a pure 3D system, which led us to speculate that the mixed-dimensional polaron has universal properties in the unitarity limit of the impurity-boson interaction.

  13. Aspects of Leptonic Flavour Mixing

    NASA Astrophysics Data System (ADS)

    Feruglio, Ferruccio

    2017-09-01

    Since the discovery of neutrino oscillations many ideas have been put forward to explain the special features of the leptonic mixing and the differences with respect to the quark sector. In this talk I review some of these proposals, emphasizing especially their predictability. In the light of the new data, I first revisit fixed-point relations among mixing angles and phases. Then I briefly comment on radiative neutrino masses. Finally I discuss the role of flavour symmetries. Given the very many existing models I focus on two classes of models. On the one hand I illustrate the ability of models based on a generalization of the anarchy idea in reproducing the main features of both the quark and the lepton spectrum, also in a GUT framework. On the other hand I discuss less ambitious but more predictive models based on discrete flavour symmetries, centered on the properties of the leptonix mixing matrix.

  14. Turbulent mix experiments and simulations

    SciTech Connect

    Dimonte, G.; Schneider, M.; Frerking, C.E.

    1995-08-01

    Hydrodynamic instabilities produce material mixing that can significantly degrade weapons performance. We investigate the Richtmyer-Meshkov (RM) and Rayleigh-Taylor (RT) instabilities in the turbulent regime in two experimental venues. RM experiments are conducted on the Nova laser with strong radiatively driven shocks (Mach > 20) in planar, two fluid targets. Interfacial perturbations are imposed with single sinusoidal modes to test linear theory and with three dimensional (3D) random modes to produce turbulent mix. RT experiments are conducted on a new facility, the Linear Electric Motor (LEM), in which macroscopic fluids are accelerated with arbitrary temporal profiles. This allows detailed diagnosis of the turbulence over a wide range of conditions. The Nova experiments study the high compression regime whereas the LEM experiments are incompressible. The results are compared to hydrodynamic simulations with the arbitrary Lagrangian-Eulerian code (CALE). The goal is to develop and test engineering models of mix.

  15. Investigation of Turbulent Mixing Processes

    NASA Technical Reports Server (NTRS)

    Viktorin, K.

    1946-01-01

    With water as driving medium and delivered medium in a device similar to a simple jet apparatus, the pressure and velocity fields of the mixing zone were explored with a pitot bar; the ratio of delivered to driving volume ranged between the values 0, 1, 2, and 4. An attempt was also made to analyze the mixing flow mathematically by integration of the equation of motion, with the aid of conventional formulas for the turbulent shearing stress, but this succeeded only approximately for the very simplified case that a driving jet is introduced in an unlimited parallel flow, while the pressure over the whole mixing field is assumed to be constant. In spite of these dissimilar assumptions for the theory and the experiment, the form of the measured and the computed velocity profiles indicates a very high degree of approximation. The pressure rise, which was approximated by Flugel's formulas, disclosed good agreement with the measured values.

  16. Nonideal Rayleigh–Taylor mixing

    PubMed Central

    Lim, Hyunkyung; Iwerks, Justin; Glimm, James; Sharp, David H.

    2010-01-01

    Rayleigh–Taylor mixing is a classical hydrodynamic instability that occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh–Taylor (RT) mixing are regularizations (physical and numerical), which produce deviations from a pure Euler equation, scale invariant formulation, and nonideal (i.e., experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We interpret mathematical theories of existence and nonuniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations; in other words, indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as nonunique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, in the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and Prandtl numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength initial conditions and long wavelength perturbations are observed to play a role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing in different proportions in these two different contexts. PMID:20615983

  17. Ion mixing of semiconductor superlattices

    NASA Astrophysics Data System (ADS)

    Xia, W.; Hsu, S. N.; Han, C. C.; Pappert, S. A.; Zhu, B.; Cozzolino, C.; Yu, P. K. L.; Lau, S. S.; Poker, D. B.; White, C. W.; Schwarz, S. A.

    1991-07-01

    Compositional disordering of III-V compound superlattice structures has received considerable attention recently due to its potential application for photonic devices. The conventional method to induce compositional disorder is to implant a moderate dose of impurity ions (˜ 10 15 cm -2) into the structure at room temperature, followed by a high-temperature annealing step (this process is referred to as IA here). Ion irradiation at room temperature alone does not cause any significant intermixing of layers. The subsequent high-temperature annealing step tends to restrict device processing flexibility. Ion mixing (IM) is capable of enhancing compositional disordering of layers at a rate which increases exponentially with the ion irradiation temperature. As a processing technique to planarize devices, ion mixing appears to be an attractive technology. In this work, we investigate compositional disordering in the AlGaAs/GaAs and the InGaAs/InP systems using ion mixing. We found that the ion mixing behavior of these two systems shows a thermally activated regime as well as an athermal regime, similar to that observed for metal-metal and metal-semiconductor systems. Ion mixing is observed to induce compositional disordering at significantly lower temperatures than that for the IA process. We have compared the two processes in terms of four parameters (1) irradiation temperature, (2) dose dependence, (3) annealing, and (4) electrically active ions. We found that the IM process is more efficient in utilizing the defects generated by ion irradiation to cause disordering. Both the physical mechanism of ion mixing and possible device implications will be discussed.

  18. Ion mixing of semiconductor superlattices

    NASA Astrophysics Data System (ADS)

    Xia, W.; Hsu, S. N.; Han, C. C.; Pappert, S. A.; Zhu, B.; Cozzolino, C.; Yu, P. K. L.; Lau, S. S.; Poker, D. B.; White, C. W.

    Compositional disordering of III-V compound superlattice structures has received considerable attention recently due to its potential application for photonic devices. The conventional method in induce compositional disorder is to implant a moderate dose of impurity ions (approx. 10 (exp 15)/sq cm) into the structure at room temperature, followed by a high temperature annealing step (this process is referred to as IA here). Ion irradiation at room temperature alone does not cause any significant intermixing of layers. The subsequent high temperature annealing step tends to restrict device processing flexibility. Ion mixing (IM) is capable of enhancing compositional disordering of layers at a rate which increases exponentially with the ion irradiation temperature. As a processing technique to planarize devices, ion mixing appears to be an attractive technology. Compositional disordering was studied disordering in the AlGaAs/GaAs and the InGaAs/InP systems using ion mixing. It was found that the ion mixing behavior of these two systems shows a thermally activated regime as well as an athermal regime, similar to that observed for metal-metal and metal-semiconductor systems. Ion mixing is observed to induce compositional disordering at significantly lower temperatures than that for the IA process. The two processes were compared in terms of five parameters (1) irradiation temperature, (2) dose dependence (3) annealing, and (4) electrically active ions. It was found that the IM process is more efficient in utilizing the defects generated by ion irradiation to cause disordering. Both the physical mechanism of ion mixing and possible device implications will be discussed.

  19. Further evidence for mixed emotions.

    PubMed

    Larsen, Jeff T; McGraw, A Peter

    2011-06-01

    Emotion theorists have long debated whether valence, which ranges from pleasant to unpleasant states, is an irreducible aspect of the experience of emotion or whether positivity and negativity are separable in experience. If valence is irreducible, it follows that people cannot feel happy and sad at the same time. Conversely, if positivity and negativity are separable, people may be able to experience such mixed emotions. The authors tested several alternative interpretations for prior evidence that happiness and sadness can co-occur in bittersweet situations (i.e., those containing both pleasant and unpleasant aspects). One possibility is that subjects who reported mixed emotions merely vacillated between happiness and sadness. The authors tested this hypothesis in Studies 1-3 by asking subjects to complete online continuous measures of happiness and sadness. Subjects reported more simultaneously mixed emotions during a bittersweet film clip than during a control clip. Another possibility is that subjects in earlier studies reported mixed emotions only because they were explicitly asked whether they felt happy and sad. The authors tested this hypothesis in Studies 4-6 with open-ended measures of emotion. Subjects were more likely to report mixed emotions after the bittersweet clip than the control clip. Both patterns occurred even when subjects were told that they were not expected to report mixed emotions (Studies 2 and 5) and among subjects who did not previously believe that people could simultaneously feel happy and sad (Studies 3 and 6). These results provide further evidence that positivity and negativity are separable in experience.

  20. Mixing in Magnetized Turbulent Media

    NASA Astrophysics Data System (ADS)

    Sur, Sharanya; Pan, Liubin; Scannapieco, Evan

    2014-04-01

    Turbulent motions are essential to the mixing of entrained fluids and are also capable of amplifying weak initial magnetic fields by small-scale dynamo action. Here we perform a systematic study of turbulent mixing in magnetized media, using three-dimensional magnetohydrodynamic simulations that include a scalar concentration field. We focus on how mixing depends on the magnetic Prandtl number, Pm, from 1 to 4 and the Mach number, { {M}}, from 0.3 to 2.4. For all subsonic flows, we find that the velocity power spectrum has a k -5/3 slope in the early kinematic phase, but steepens due to magnetic back reactions as the field saturates. The scalar power spectrum, on the other hand, flattens compared to k -5/3 at late times, consistent with the Obukohov-Corrsin picture of mixing as a cascade process. At higher Mach numbers, the velocity power spectrum also steepens due to the presence of shocks, and the scalar power spectrum again flattens accordingly. Scalar structures are more intermittent than velocity structures in subsonic turbulence, whereas for supersonic turbulence, velocity structures appear more intermittent than the scalars only in the kinematic phase. Independent of the Mach number of the flow, scalar structures are arranged in sheets in both the kinematic and saturated phases of the magnetic field evolution. For subsonic turbulence, scalar dissipation is hindered in the strong magnetic field regions, probably due to Lorentz forces suppressing the buildup of scalar gradients, whereas for supersonic turbulence, scalar dissipation increases monotonically with increasing magnetic field strength. At all Mach numbers, mixing is significantly slowed by the presence of dynamically important small-scale magnetic fields, implying that mixing in the interstellar medium and in galaxy clusters is less efficient than modeled in hydrodynamic simulations.

  1. Nonideal Rayleigh-Taylor mixing.

    PubMed

    Lim, Hyunkyung; Iwerks, Justin; Glimm, James; Sharp, David H

    2010-07-20

    Rayleigh-Taylor mixing is a classical hydrodynamic instability that occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh-Taylor (RT) mixing are regularizations (physical and numerical), which produce deviations from a pure Euler equation, scale invariant formulation, and nonideal (i.e., experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We interpret mathematical theories of existence and nonuniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations; in other words, indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as nonunique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, in the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and Prandtl numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength initial conditions and long wavelength perturbations are observed to play a role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing in different proportions in these two different contexts.

  2. Nonideal Rayleigh-Taylor mixing

    SciTech Connect

    Sharp, David Howland; Lin, Hyun K; Iwerks, Justin G; Gliman, James G

    2009-01-01

    Rayleigh-Taylor mixing is a classical hydrodynamic Instability, which occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh-Taylor (RT) mixing are regularizations (physical and numerical) which produce deviations from a pure Euler equation, scale Invariant formulation, and non Ideal (i.e. experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We Interpret mathematical theories of existence and non-uniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations, in other words indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as non unique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, In the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and PrandtJ numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength Initial conditions and long wavelength perturbations are observed to playa role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing In different proportions In these two different contexts.

  3. Mixing in magnetized turbulent media

    SciTech Connect

    Sur, Sharanya; Scannapieco, Evan; Pan, Liubin E-mail: evan.scannapieco@asu.edu

    2014-04-01

    Turbulent motions are essential to the mixing of entrained fluids and are also capable of amplifying weak initial magnetic fields by small-scale dynamo action. Here we perform a systematic study of turbulent mixing in magnetized media, using three-dimensional magnetohydrodynamic simulations that include a scalar concentration field. We focus on how mixing depends on the magnetic Prandtl number, Pm, from 1 to 4 and the Mach number, M, from 0.3 to 2.4. For all subsonic flows, we find that the velocity power spectrum has a k {sup –5/3} slope in the early kinematic phase, but steepens due to magnetic back reactions as the field saturates. The scalar power spectrum, on the other hand, flattens compared to k {sup –5/3} at late times, consistent with the Obukohov-Corrsin picture of mixing as a cascade process. At higher Mach numbers, the velocity power spectrum also steepens due to the presence of shocks, and the scalar power spectrum again flattens accordingly. Scalar structures are more intermittent than velocity structures in subsonic turbulence, whereas for supersonic turbulence, velocity structures appear more intermittent than the scalars only in the kinematic phase. Independent of the Mach number of the flow, scalar structures are arranged in sheets in both the kinematic and saturated phases of the magnetic field evolution. For subsonic turbulence, scalar dissipation is hindered in the strong magnetic field regions, probably due to Lorentz forces suppressing the buildup of scalar gradients, whereas for supersonic turbulence, scalar dissipation increases monotonically with increasing magnetic field strength. At all Mach numbers, mixing is significantly slowed by the presence of dynamically important small-scale magnetic fields, implying that mixing in the interstellar medium and in galaxy clusters is less efficient than modeled in hydrodynamic simulations.

  4. Mixe de Tlahuitoltepec, Oaxaca (Mixe of Tlahuitoltepec, Oaxaca).

    ERIC Educational Resources Information Center

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Mixe, an indigenous language of Mexico spoken in Tlahuitoltepec, in the state of Oaxaca. The objective of collecting such a representative sampling of the…

  5. Use and abuse of mixing models (MixSIAR)

    EPA Science Inventory

    Background/Question/MethodsCharacterizing trophic links in food webs is a fundamental ecological question. In our efforts to quantify energy flow through food webs, ecologists have increasingly used mixing models to analyze biological tracer data, often from stable isotopes. Whil...

  6. Use and abuse of mixing models (MixSIAR)

    EPA Science Inventory

    Background/Question/MethodsCharacterizing trophic links in food webs is a fundamental ecological question. In our efforts to quantify energy flow through food webs, ecologists have increasingly used mixing models to analyze biological tracer data, often from stable isotopes. Whil...

  7. Polarization mixing optical parametric oscillator.

    SciTech Connect

    Pearl, Shaul; Smith, Arlee Virgil; Arie, Ady; Blau, Pinhas; Kalmani, Gal

    2005-05-01

    We report the experimental realization of a new type of optical parametric oscillator in which oscillation is achieved by polarization rotation in a linear retarder, followed by nonlinear polarization mixing. The mixing is performed by a type II degenerate parametric downconversion in a periodically poled KTP crystal pumped by a 1064 nm pulsed Nd:YAG pump. A single, linearly polarized beam, precisely at the degenerate wavelength is generated. The output spectrum has a narrow linewidth (below the instrumentation bandwidth of 1 nm) and is highly stable with respect to variations in the crystal temperature.

  8. Bs Mixing at the Tevatron

    SciTech Connect

    Gomez-Ceballos, Guillelmo; /Cantabria Inst. of Phys.

    2006-04-01

    The Tevatron collider at Fermilab provides a very rich environment for the study of B{sub s} mesons. B{sub s} Mixing is the most important analysis within the B Physics program of both experiments. In this paper they summarize the most recent results on this topic from both D0 and CDF experiments. There were very important updates in both experiments after his last talk, hence the organizers warmly recommended me to include the latest available results on B{sub s} mixing, instead of what he presents there.

  9. Mixed ternary heterojunction solar cell

    DOEpatents

    Chen, Wen S.; Stewart, John M.

    1992-08-25

    A thin film heterojunction solar cell and a method of making it has a p-type layer of mixed ternary I-III-VI.sub.2 semiconductor material in contact with an n-type layer of mixed binary II-VI semiconductor material. The p-type semiconductor material includes a low resistivity copper-rich region adjacent the back metal contact of the cell and a composition gradient providing a minority carrier mirror that improves the photovoltaic performance of the cell. The p-type semiconductor material preferably is CuInGaSe.sub.2 or CuIn(SSe).sub.2.

  10. Mixing of atmospheric gas concentrations.

    PubMed

    Clement, C F; Ford, I J; Twohy, C H

    2000-04-24

    Atmospheric gas concentrations were measured at 1 s intervals in the upper troposphere during a flight through and near the anvil of a storm. The observed very high correlations between the concentrations of CO and CH4 are interpreted as arising from the mixing of two distinct air masses with differing concentrations of each species, and is due to the nearly identical diffusivities of CO and CH4 in air. We find that the correlations depend on the period over which each concentration measurement was made. Correlations in measurements made over short periods decay with time, while correlations over larger scales remain high. We interpret this using a simple mixing model.

  11. An Efficient Alternative Mixed Randomized Response Procedure

    ERIC Educational Resources Information Center

    Singh, Housila P.; Tarray, Tanveer A.

    2015-01-01

    In this article, we have suggested a new modified mixed randomized response (RR) model and studied its properties. It is shown that the proposed mixed RR model is always more efficient than the Kim and Warde's mixed RR model. The proposed mixed RR model has also been extended to stratified sampling. Numerical illustrations and graphical…

  12. On the quantification of mixing in microfluidics.

    PubMed

    Hashmi, Ali; Xu, Jie

    2014-10-01

    Methods for quantifying mixing in microfluidics have varied largely in the past, and various indices have been employed to represent the extent of mixing. Mixing between two or more colored liquids is usually quantified using simple mathematical functions operated over a sequence of images. The function, usually termed mixing indices, involves a measure of standard deviation. Here, we first review some mixing indices and then experimentally verify the index most representative of a mixing event. It is observed that the relative mixing index is not affected by the lighting conditions, unlike other known mixing indices. Based on this finding, the use of a relative mixing index is advocated for further use in the lab-on-a-chip community for quantifying mixing events. © 2014 Society for Laboratory Automation and Screening.

  13. Towards understanding turbulent scalar mixing

    NASA Technical Reports Server (NTRS)

    Girimaji, Sharath S.

    1992-01-01

    In an effort towards understanding turbulent scalar mixing, we study the effect of molecular mixing, first in isolation and then by accounting for the effects of the velocity field. The chief motivation for this approach stems from the strong resemblance of the scalar probability density function (PDF) obtained from the scalar field evolving from the heat conduction equation that arises in a turbulent velocity field. However, the evolution of the scalar dissipation is different for the two cases. We attempt to account for these differences, which are due to the velocity field, using a Lagrangian frame analysis. After establishing the usefulness of this approach, we use the heat-conduction simulations (HCS), in lieu of the more expensive direct numerical simulations (DNS), to study many of the less understood aspects of turbulent mixing. Comparison between the HCS data and available models are made whenever possible. It is established that the beta PDF characterizes the evolution of the scalar PDF during mixing from all types of non-premixed initial conditions.

  14. Simple rheology of mixed proteins

    USDA-ARS?s Scientific Manuscript database

    Mixing different proteins to form strong gel networks for food applications may create synergistic increases in viscoelasticity that cannot be achieved with a single protein. In this study, small amplitude oscillatory shear analyses were used to investigate the rheology of calcium caseinate (CC), e...

  15. Turbulent Mixing Chemistry in Disks

    NASA Astrophysics Data System (ADS)

    Semenov, D.; Wiebe, D.

    2006-11-01

    A gas-grain chemical model with surface reaction and 1D/2D turbulent mixing is available for protoplanetary disks and molecular clouds. Current version is based on the updated UMIST'95 database with gas-grain interactions (accretion, desorption, photoevaporation, etc.) and modified rate equation approach to surface chemistry (see also abstract for the static chemistry code).

  16. Racially Mixed People in America.

    ERIC Educational Resources Information Center

    Root, Maria P. P., Ed.

    This book offers a comprehensive look at the social and psychological adjustment of multiracial people, models for identity development, contemporary immigration and marriage patterns, and methodological issues involved in conducting research with mixed-race people, all in the context of America's multiracial past and present. The following 26…

  17. Racially Mixed People in America.

    ERIC Educational Resources Information Center

    Root, Maria P. P., Ed.

    This book offers a comprehensive look at the social and psychological adjustment of multiracial people, models for identity development, contemporary immigration and marriage patterns, and methodological issues involved in conducting research with mixed-race people, all in the context of America's multiracial past and present. The following 26…

  18. Bayesian stable isotope mixing models

    EPA Science Inventory

    In this paper we review recent advances in Stable Isotope Mixing Models (SIMMs) and place them into an over-arching Bayesian statistical framework which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixtur...

  19. [Treatment of depressive mixed states].

    PubMed

    Dubois, M; Dassa, D; Belzeaux, R; Fakra, E; Cermolacce, M; Corréard, N; Kaladjian, A; Azorin, J-M

    2013-12-01

    Mixed states are a frequent mood state characterized by the mixture of manic and depressive symptoms. Their clinical description has been studied for centuries but has known a renewal of interest recently. Several authors intend to redefine its diagnostic criteria to develop an appropriate therapeutic strategy. Current recommendations suggest to treat mixed depression as a mixed state whatever the dominant polarity is, and therefore according to the rules of therapeutic management of the manic state. Mood stabilizers and antipsychotic medications are indicated and have proven their effectiveness. Lithium, which was considered controversial, now appears to have some therapeutic value, especially in the prevention of suicidal behavior. The depressive component of mixed states, even pronounced, should not be an argument for a prescription of antidepressants, at the risk of aggravating clinical components such as irritability and impulsivity and increasing the danger of suicide attempt. Furthermore, electroconvulsivetherapy represents a real alternative ; psychotherapies have their place in relapse prevention and psychoeducation, but not during acute phases. Finally, an accurate assessment and appropriate management of suicide risk should be a constant concern for the clinicians. Copyright © 2013 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

  20. Mixing It Up with Acrylics.

    ERIC Educational Resources Information Center

    Laird, Shirley

    1999-01-01

    Presents an art activity for fifth-grade students in which they learn about basic shapes and what happens when shapes overlap, draw seven overlapping geometric shapes, review the use of acrylic paint and mixing colors, and finally paint with primary colors. (CMK)

  1. Mixed Ability Teaching Versus Streaming.

    ERIC Educational Resources Information Center

    Marklund, Sixten

    1984-01-01

    Discusses development of pupil grouping in European compulsory education into two opposite class organization types, mixed ability classes and ability-grouped classes. Categorizes the types along two dimensions with three program types and three grouping types, yielding nine teaching categories. Discusses comparative results of streaming and mixed…

  2. Colour Mixing Based on Daylight

    ERIC Educational Resources Information Center

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

  3. Mixing and transport. [Water pollution

    SciTech Connect

    Roberts, P.J.W.

    1982-06-01

    The mixing and transport of water pollution is the subject of this literature review with 110 references. The environmental transport of pollutants is examined in streams, rivers, reservoirs, ponds, estuaries, salt marshes and coastal waters. The dynamics of fluid flow, and the physical properties of jets, plumes, and stratified fluids are discussed. (KRM)

  4. CASKAD. Manual Mixing in Bioreactor

    NASA Image and Video Library

    2013-10-05

    ISS037-E-005694 (5 Oct. 2013) --- Russian cosmonaut Sergey Ryazanskiy, Expedition 37 flight engineer, prepares to manually mix samples in a Bioreactor for the CASKAD experiment in the Poisk Mini-Research Module 2 (MRM2) of the International Space Station.

  5. CASKAD. Manual Mixing in Bioreactor

    NASA Image and Video Library

    2013-10-05

    ISS037-E-005692 (5 Oct. 2013) --- Russian cosmonaut Sergey Ryazanskiy, Expedition 37 flight engineer, prepares to manually mix samples in a Bioreactor for the CASKAD experiment in the Poisk Mini-Research Module 2 (MRM2) of the International Space Station.

  6. Bayesian stable isotope mixing models

    EPA Science Inventory

    In this paper we review recent advances in Stable Isotope Mixing Models (SIMMs) and place them into an over-arching Bayesian statistical framework which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixtur...

  7. Colour Mixing Based on Daylight

    ERIC Educational Resources Information Center

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

  8. Mixing It Up with Acrylics.

    ERIC Educational Resources Information Center

    Laird, Shirley

    1999-01-01

    Presents an art activity for fifth-grade students in which they learn about basic shapes and what happens when shapes overlap, draw seven overlapping geometric shapes, review the use of acrylic paint and mixing colors, and finally paint with primary colors. (CMK)

  9. Advances in compressible turbulent mixing

    SciTech Connect

    Dannevik, W.P.; Buckingham, A.C.; Leith, C.E.

    1992-01-01

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

  10. Reductant injection and mixing system

    SciTech Connect

    Reeves, Matt; Henry, Cary A.; Ruth, Michael J.

    2016-02-16

    A gaseous reductant injection and mixing system is described herein. The system includes an injector for injecting a gaseous reductant into an exhaust gas stream, and a mixer attached to a surface of the injector. The injector includes a plurality of apertures through which the gaseous reductant is injected into an exhaust gas stream. The mixer includes a plurality of fluid deflecting elements.

  11. Bilarge neutrino mixing and the Cabibbo angle

    NASA Astrophysics Data System (ADS)

    Boucenna, S. M.; Morisi, S.; Tórtola, M.; Valle, J. W. F.

    2012-09-01

    Recent measurements of the neutrino mixing angles cast doubt on the validity of the so-far popular tribimaximal mixing Ansatz. We propose a parametrization for the neutrino mixing matrix where the reactor angle seeds the large solar and atmospheric mixing angles, equal to each other in first approximation. We suggest such a bilarge mixing pattern as a model-building standard, realized when the leading order value of θ13 equals the Cabibbo angle λC.

  12. A mixed relaxed clock model

    PubMed Central

    2016-01-01

    Over recent years, several alternative relaxed clock models have been proposed in the context of Bayesian dating. These models fall in two distinct categories: uncorrelated and autocorrelated across branches. The choice between these two classes of relaxed clocks is still an open question. More fundamentally, the true process of rate variation may have both long-term trends and short-term fluctuations, suggesting that more sophisticated clock models unfolding over multiple time scales should ultimately be developed. Here, a mixed relaxed clock model is introduced, which can be mechanistically interpreted as a rate variation process undergoing short-term fluctuations on the top of Brownian long-term trends. Statistically, this mixed clock represents an alternative solution to the problem of choosing between autocorrelated and uncorrelated relaxed clocks, by proposing instead to combine their respective merits. Fitting this model on a dataset of 105 placental mammals, using both node-dating and tip-dating approaches, suggests that the two pure clocks, Brownian and white noise, are rejected in favour of a mixed model with approximately equal contributions for its uncorrelated and autocorrelated components. The tip-dating analysis is particularly sensitive to the choice of the relaxed clock model. In this context, the classical pure Brownian relaxed clock appears to be overly rigid, leading to biases in divergence time estimation. By contrast, the use of a mixed clock leads to more recent and more reasonable estimates for the crown ages of placental orders and superorders. Altogether, the mixed clock introduced here represents a first step towards empirically more adequate models of the patterns of rate variation across phylogenetic trees. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. PMID:27325829

  13. A mixed relaxed clock model.

    PubMed

    Lartillot, Nicolas; Phillips, Matthew J; Ronquist, Fredrik

    2016-07-19

    Over recent years, several alternative relaxed clock models have been proposed in the context of Bayesian dating. These models fall in two distinct categories: uncorrelated and autocorrelated across branches. The choice between these two classes of relaxed clocks is still an open question. More fundamentally, the true process of rate variation may have both long-term trends and short-term fluctuations, suggesting that more sophisticated clock models unfolding over multiple time scales should ultimately be developed. Here, a mixed relaxed clock model is introduced, which can be mechanistically interpreted as a rate variation process undergoing short-term fluctuations on the top of Brownian long-term trends. Statistically, this mixed clock represents an alternative solution to the problem of choosing between autocorrelated and uncorrelated relaxed clocks, by proposing instead to combine their respective merits. Fitting this model on a dataset of 105 placental mammals, using both node-dating and tip-dating approaches, suggests that the two pure clocks, Brownian and white noise, are rejected in favour of a mixed model with approximately equal contributions for its uncorrelated and autocorrelated components. The tip-dating analysis is particularly sensitive to the choice of the relaxed clock model. In this context, the classical pure Brownian relaxed clock appears to be overly rigid, leading to biases in divergence time estimation. By contrast, the use of a mixed clock leads to more recent and more reasonable estimates for the crown ages of placental orders and superorders. Altogether, the mixed clock introduced here represents a first step towards empirically more adequate models of the patterns of rate variation across phylogenetic trees.This article is part of the themed issue 'Dating species divergences using rocks and clocks'.

  14. Paleoenvironment of the Permian rocks: a comparison between central and eastern Alborz, Iran

    NASA Astrophysics Data System (ADS)

    Lankarani, M.; Amini, A.; Mosadegh, H.

    2009-04-01

    The succession of Permian rocks in Alborz region is composed of siliciclastic and carbonate facies. All of the sediments were deposited in the Paleotethyan passive continental margin but they show different facies architecture and paleoenvironmental condition in various parts of the region. This study, as part of a wider project, has investigated sedimentary facies and paleoenvironment of the Permian rocks in central and eastern Alborz. The Permian rocks in central Alborz are dominated by siliciclastic facies (Doroud Formation) in the lower, and carbonate facies (Ruteh Formation) in the upper half. Field studies and laboratory measurements resulted in recognition of 4 terrigenous and 13 carbonate facies in the succession. A siliciclastic shallow marine system was determined as depositional environment of the terrigenous facies. A homoclinal carbonate ramp, with scattered patch reefs, was determined as depositional environment of the carbonate facies. Dasycladacean green algae, ancestral red algae, hermatypic corals and bryozoans were the major bioconstructors of the ramp. The abundance of skeletal shoals respect to ooidal shoals in the ramp margin was high. The Permian rocks in eastern Alborz are dominated by mixed siliciclastic-carbonate facies (Ruteh Formation) in the lower, and siliciclastic facies (Nesen Formation) in the upper half. The studies resulted in recognition of 5 terrigenous and 6 carbonate facies in the succession. A mixed siliciclastic-carbonate shelf with high sediment influx was determined as depositional environment of the mixed siliciclastic-carbonate facies. Occurrence of the small patch reefs with high coral diversity in this mixed shelf indicates normal marine (hyposaline) condition. Upper terrigenous facies were deposited in fluvial-flood plain system. Difference in paleoclimate and tectonic activity of two sub-basins seems to be the major cause of the differences between the Permian facies in central and eastern Alborz.

  15. Mixed methods research in mental health nursing.

    PubMed

    Kettles, A M; Creswell, J W; Zhang, W

    2011-08-01

    Mixed methods research is becoming more widely used in order to answer research questions and to investigate research problems in mental health and psychiatric nursing. However, two separate literature searches, one in Scotland and one in the USA, revealed that few mental health nursing studies identified mixed methods research in their titles. Many studies used the term 'embedded' but few studies identified in the literature were mixed methods embedded studies. The history, philosophical underpinnings, definition, types of mixed methods research and associated pragmatism are discussed, as well as the need for mixed methods research. Examples of mental health nursing mixed methods research are used to illustrate the different types of mixed methods: convergent parallel, embedded, explanatory and exploratory in their sequential and concurrent combinations. Implementing mixed methods research is also discussed briefly and the problem of identifying mixed methods research in mental and psychiatric nursing are discussed with some possible solutions to the problem proposed.

  16. HETEROGENEOUS REBURNING BY MIXED FUELS

    SciTech Connect

    Wei-Yin Chen; Benson B. Gathitu

    2005-01-14

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  17. Pediatric Mixed Connective Tissue Disease.

    PubMed

    Berard, Roberta A; Laxer, Ronald M

    2016-05-01

    Pediatric-onset mixed connective tissue disease is among the rare disease entities in pediatric rheumatology and includes features of arthritis, polymyositis/dermatomyositis, systemic lupus erythematosus, and systemic sclerosis. Accurate recognition and diagnosis of the disease is paramount to prevent long-term morbidity. Advances in the genetic and immunologic understanding of the factors involved in the etiopathogenesis provide an opportunity for improvements in prognostication and targeted therapy. The development of a multinational cohort of patients with mixed connective tissue disease would be invaluable to provide more updated data regarding the clinical presentation, to develop a standardized treatment approach, disease activity and outcome tools, and to provide data on long-term outcomes and comorbidities.

  18. Mixing enhancement using axial flow

    NASA Technical Reports Server (NTRS)

    Papamoschou, Dimitri (Inventor)

    2003-01-01

    A method and an apparatus for enhancing fluid mixing. The method comprises the following: (a) configuring a duct to have an effective outer wall, an effective inner wall, a cross-sectional shape, a first cross-sectional area and an exit area, the first cross-sectional area and the exit area being different in size; (b) generating a first flow at the first cross-sectional area, the first flow having a total pressure and a speed equal to or greater than a local speed of sound; and (c) generating a positive streamwise pressure gradient in a second flow in proximity of the exit area. The second flow results from the first flow. Fluid mixing is enhanced downstream from the duct exit area.

  19. Topological mixing with ghost rods

    NASA Astrophysics Data System (ADS)

    Gouillart, Emmanuelle; Thiffeault, Jean-Luc; Finn, Matthew D.

    2006-03-01

    Topological chaos relies on the periodic motion of obstacles in a two-dimensional flow in order to form nontrivial braids. This motion generates exponential stretching of material lines, and hence efficient mixing. Boyland, Aref, and Stremler [J. Fluid Mech. 403, 277 (2000)] have studied a specific periodic motion of rods that exhibits topological chaos in a viscous fluid. We show that it is possible to extend their work to cases where the motion of the stirring rods is topologically trivial by considering the dynamics of special periodic points that we call “ghost rods”, because they play a similar role to stirring rods. The ghost rods framework provides a new technique for quantifying chaos and gives insight into the mechanisms that produce chaos and mixing. Numerical simulations for Stokes flow support our results.

  20. Topological mixing with ghost rods.

    PubMed

    Gouillart, Emmanuelle; Thiffeault, Jean-Luc; Finn, Matthew D

    2006-03-01

    Topological chaos relies on the periodic motion of obstacles in a two-dimensional flow in order to form nontrivial braids. This motion generates exponential stretching of material lines, and hence efficient mixing. Boyland, Aref, and Stremler [J. Fluid Mech. 403, 277 (2000)] have studied a specific periodic motion of rods that exhibits topological chaos in a viscous fluid. We show that it is possible to extend their work to cases where the motion of the stirring rods is topologically trivial by considering the dynamics of special periodic points that we call "ghost rods", because they play a similar role to stirring rods. The ghost rods framework provides a new technique for quantifying chaos and gives insight into the mechanisms that produce chaos and mixing. Numerical simulations for Stokes flow support our results.

  1. Kinetic mixing at strong coupling

    NASA Astrophysics Data System (ADS)

    Del Zotto, Michele; Heckman, Jonathan J.; Kumar, Piyush; Malekian, Arada; Wecht, Brian

    2017-01-01

    A common feature of many string-motivated particle physics models is additional strongly coupled U (1 )'s. In such sectors, electric and magnetic states have comparable mass, and integrating out modes also charged under U (1 ) hypercharge generically yields C P preserving electric kinetic mixing and C P violating magnetic kinetic mixing terms. Even though these extra sectors are strongly coupled, we show that in the limit where the extra sector has approximate N =2 supersymmetry, we can use formal methods from Seiberg-Witten theory to compute these couplings. We also calculate various quantities of phenomenological interest such as the cross section for scattering between visible sector states and heavy extra sector states as well as the effects of supersymmetry breaking induced from coupling to the minimal supersymmetric Standard Model.

  2. Heterogeneous Reburning By Mixed Fuels

    SciTech Connect

    Anderson Hall

    2009-03-31

    Recent studies of heterogeneous reburning, i.e., reburning involving a coal-derived char, have elucidated its variables, kinetics and mechanisms that are valuable to the development of a highly efficient reburning process. Young lignite chars contain catalysts that not only reduce NO, but they also reduce HCN that is an important intermediate that recycles to NO in the burnout zone. Gaseous CO scavenges the surface oxides that are formed during NO reduction, regenerating the active sites on the char surface. Based on this mechanistic information, cost-effective mixed fuels containing these multiple features has been designed and tested in a simulated reburning apparatus. Remarkably high reduction of NO and HCN has been observed and it is anticipated that mixed fuel will remove 85% of NO in a three-stage reburning process.

  3. MISO - Mixed Integer Surrogate Optimization

    SciTech Connect

    Mueller, Juliane

    2016-01-20

    MISO is an optimization framework for solving computationally expensive mixed-integer, black-box, global optimization problems. MISO uses surrogate models to approximate the computationally expensive objective function. Hence, derivative information, which is generally unavailable for black-box simulation objective functions, is not needed. MISO allows the user to choose the initial experimental design strategy, the type of surrogate model, and the sampling strategy.

  4. Mixing in the solar tachocline

    NASA Astrophysics Data System (ADS)

    Brun, Allan Sacha

    We conduct numerical simulations of updated solar models including a physical treatment of the tachocline (Spiegel & Zahn 1992), the rotational transition layer localized at the base of the solar convection zone. We first describe what is the current understanding of this thin shear layer. We then show that we improve substantially the agreement between the models and the observed Sun by taking into account the macroscopic mixing occurring within this region.

  5. Turbulent Mixing of Multiphase Flow

    DTIC Science & Technology

    2003-12-01

    field modeling approach to investigate capillary induced effects on mixing. Phase- field modeling has been applied to simulation of multi-phase flow... effect of surface tension on stirring flows. The phase-field function C denotes the phase of the fluid: C = ±1 corresponds to fluid phase 1 and 2...force is non-zero only at the interface: F, = (unti + Osa•)6(¢), where au is the Marangoni force, with s the axclength and 9 the unit vectors along the

  6. Lidar for Lateral Mixing (LATMIX)

    DTIC Science & Technology

    2013-09-30

    km, i.e., the “ submesoscale ”. We aim to understand the underlying mechanisms and forcing, as well as the temporal, spatial, and scale variability of...the overall objectives of the Lateral Mixing DRI to try to determine the extent to which submesoscale stirring is driven by a cascade of energy down...technical goal of our work is to develop the use of airborne LIDAR surveys of evolving dye experiments as a tool for studying submesoscale lateral dispersion

  7. Mixed real/complex factorization

    SciTech Connect

    Lima, L.T.G. . Dept. of Electrical Engineering); Martines, N.; Pinto, H.J.C.P. . Centro de Pesquisas de Energia Electrica)

    1993-02-01

    This paper describes a mixed real/complex sparse matrix factorization and solution scheme applied to a large matrix problem. Large system eigenanalysis and frequency domain methods will directly benefit from the proposed scheme, which can reduce both memory and CPU time requirements when compared to conventional complex-only solutions. The application in hand is the small signal electromechanical stability analysis of large power systems. The savings obtained are significant considering the CPU intensive nature of these matrix problems.

  8. Precise predictions for Dirac neutrino mixing

    NASA Astrophysics Data System (ADS)

    Abbas, Gauhar; Abyaneh, Mehran Zahiri; Srivastava, Rahul

    2017-04-01

    The neutrino mixing parameters are thoroughly studied using renormalization-group evolution of Dirac neutrinos with recently proposed parametrization of the neutrino mixing angles referred to as "high-scale mixing relations." The correlations among all neutrino mixing and C P violating observables are investigated. The predictions for the neutrino mixing angle θ23 are precise, and could be easily tested by ongoing and future experiments. We observe that the high-scale mixing unification hypothesis is incompatible with Dirac neutrinos due to updated experimental data.

  9. Shear mixing in classical Novae

    NASA Astrophysics Data System (ADS)

    Alexakis, A.; Calder, A. C.; Dursi, L. J.; Times, F. X.; Truran, J. W.; Rosner, R.; Lamb, D. M.; Mignone, A.; Fryxel, B.; Zingale, M.; Olson, K.; Ricker, P.

    2003-03-01

    The mixing of white dwarf material with the accretion envelope in classical novae scenarios is essential for the later evolution and the outburst. One of the plausible mechanisms for the enrichment involves the coupling of large scale flows like convection or accretion with the breaking interfacial waves at the white dwarf surface. We examine how the interaction of accretion wind with a white dwarf surface can lead to a substantial C/O enrichment that can power a novae. We use the FLASH code to perform two and three dimensional simulations of wind driven gravity waves and investigate their growth and non-linear development for a variety of wind profiles. Our results show that even weak winds generate gravity waves through a resonant mechanism with the wind that grow nonlinear and break leading to spray formation and mixing. The total amount of white dwarf material mixed at late times, is shown to be proportional to the square of the maximum wind velocity, inversely proportional to gravity and independent of the functional form of the wind profile. This work has been supported by the DOE ASCI/Alliances program at the University of Chicago under grant No. B341495.

  10. Ion mixing and phase diagrams

    NASA Astrophysics Data System (ADS)

    Lau, S. S.; Liu, B. X.; Nicolet, M.-A.

    1983-05-01

    Interactions induced by ion irradiation are generally considered to be non-equilibrium processes, whereas phase diagrams are determined by phase equilibria. These two entities are seemingly unrelated. However, if one assumes that quasi-equilibrium conditions prevail after the prompt events, subsequent reactions are driven toward equilibrium by thermodynamical forces. Under this assumption, ion-induced reactions are related to equilibrium and therefore to phase diagrams. This relationship can be seen in the similarity that exists in thin films between reactions induced by ion irradiation and reactions induced by thermal annealing. In the latter case, phase diagrams have been used to predict the phase sequence of stable compound formation, notably so in cases of silicide formation. Ion-induced mixing not only can lead to stable compound formation, but also to metastable alloy formation. In some metal-metal systems, terminal solubilities can be greatly extended by ion mixing. In other cases, where the two constituents of the system have different crystal structures, extension of terminal solubility from both sides of the phase diagram eventually becomes structurally incompatible and a glassy (amorphous) mixture can form. The composition range where this bifurcation is likely to occur is in the two-phase regions of the phase diagram. These concepts are potentially useful guides in selecting metal pairs that from metallic glasses by ion mixing. In this report, phenomenological correlation between stable (and metastable) phase formation and phase diagram is discussed in terms of recent experimental data.

  11. Mixed Alcohol Synthesis Catalyst Screening

    SciTech Connect

    Gerber, Mark A.; White, James F.; Stevens, Don J.

    2007-09-03

    National Renewable Energy Laboratory (NREL) and Pacific Northwest National Laboratory (PNNL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially available or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. From the standpoint of producing C2+ alcohols as the major product, it appears that the rhodium catalyst is the best choice in terms of both selectivity and space-time yield (STY). However, unless the rhodium catalyst can be improved to provide minimally acceptable STYs for commercial operation, mixed alcohol synthesis will involve significant production of other liquid coproducts. The modified Fischer-Tropsch catalyst shows the most promise for providing both an acceptable selectivity to C2+ alcohols and total liquid STY. However, further optimization of the Fischer-Tropsch catalysts to improve selectivity to higher alcohols is highly desired. Selection of a preferred catalyst will likely entail a decision on the preferred coproduct slate. No other catalysts tested appear amenable to the significant improvements needed for acceptable STYs.

  12. Assessing mixed waste treatment technologies

    SciTech Connect

    Berry, J.B.; Bloom, G.A.; Hart, P.W.

    1994-06-01

    The US Department of Energy (DOE) is responsible for the management and treatment of its mixed low-level wastes (MLLW). As discussed earlier in this conference MLLW are regulated under both the Resource Conservation and Recovery Act and various DOE orders. During the next 5 years, DOE will manage over 1,200,000 m{sup 3} of MLLW and mixed transuranic (MTRU) waste at 50 sites in 22 states (see Table 1). The difference between MLLW and MTRU waste is in the concentration of elements that have a higher atomic weight than uranium. Nearly all of this waste will be located at 13 sites. More than 1400 individual mixed waste streams exist with different chemical and physical matrices containing a wide range of both hazardous and radioactive contaminants. Their containment and packaging vary widely (e.g., drums, bins, boxes, and buried waste). This heterogeneity in both packaging and waste stream constituents makes characterization difficult, which results in costly sampling and analytical procedures and increased risk to workers.

  13. Scalable Lateral Mixing and Coherent Turbulence (LatMix) DRI: Turbulence-Resolving Simulations of Upper-Ocean Lateral Mixing

    DTIC Science & Technology

    2013-09-30

    The interaction of finescale and submesoscale upper-ocean mixing at fronts. OBJECTIVES Physically-based parameterizations of vertical mixed layer...dimensions of the oblong domain geometry on realized submesoscale instabilities. Figure 1: Surface buoyancy b from LES of baroclinic mixed layer

  14. Testing Mixed Distributions when the Mixing Distribution Is Known

    NASA Astrophysics Data System (ADS)

    Pommeret, Denys

    In this paper we present smooth goodness of fit tests for testing the mixture distribution of a sequence of i.i.d. random variables. We consider mixture models when the mixing distribution is known. We adapt a Schwarz’s criteria initiated by Ledwina (J Am Stat Assoc 89:1000-1005, 1994) and inspired by the Neyman (Skandinavian Aktuarial 20:149-199, 1937) smooth test procedure. A Monte Carlo study is provided in order to assess the performance of the test.

  15. A survey of mixed finite element methods

    NASA Technical Reports Server (NTRS)

    Brezzi, F.

    1987-01-01

    This paper is an introduction to and an overview of mixed finite element methods. It discusses the mixed formulation of certain basic problems in elasticity and hydrodynamics. It also discusses special techniques for solving the discrete problem.

  16. Understanding Mixed Emotions: Paradigms and Measures.

    PubMed

    Kreibig, Sylvia D; Gross, James J

    2017-06-01

    In this review, we examine the paradigms and measures available for experimentally studying mixed emotions in the laboratory. For eliciting mixed emotions, we describe a mixed emotions film library that allows for the repeated elicitation of a specific homogeneous mixed emotional state and appropriately matched pure positive, pure negative, and neutral emotional states. For assessing mixed emotions, we consider subjective and objective measures that fall into univariate, bivariate, and multivariate measurement categories. As paradigms and measures for objectively studying mixed emotions are still in their early stages, we conclude by outlining future directions that focus on the reliability, temporal dynamics, and response coherence of mixed emotions paradigms and measures. This research will build a strong foundation for future studies and significantly advance our understanding of mixed emotions.

  17. Model Verification of Mixed Dynamic Systems

    NASA Technical Reports Server (NTRS)

    Evensen, D. A.; Chrostowski, J. D.; Hasselman, T. K.

    1982-01-01

    MOVER uses experimental data to verify mathematical models of "mixed" dynamic systems. The term "mixed" refers to interactive mechanical, hydraulic, electrical, and other components. Program compares analytical transfer functions with experiment.

  18. The importance and challenge of hyporheic mixing

    NASA Astrophysics Data System (ADS)

    Hester, Erich T.; Cardenas, M. Bayani; Haggerty, Roy; Apte, Sourabh V.

    2017-05-01

    The hyporheic zone is the interface beneath and adjacent to streams and rivers where surface water and groundwater interact. The hyporheic zone presents unique conditions for reaction of solutes from both surface water and groundwater, including reactions which depend upon mixing of source waters. Some models assume that hyporheic zones are well-mixed and conceptualize the hyporheic zone as a surface water-groundwater mixing zone. But what are the controls on and effects of hyporheic mixing? What specific mechanisms cause the relatively large (>˜1 m) mixing zones suggested by subsurface solute measurements? In this commentary, we explore the various processes that might enhance mixing in the hyporheic zone relative to deeper groundwater, and pose the question whether the substantial mixing suggested by field studies may be due to the combination of fluctuating boundary conditions and multiscale physical and chemical spatial heterogeneity. We encourage investigation of hyporheic mixing using numerical modeling and laboratory experiments to ultimately inform field investigations.

  19. Bounding CKM Mixing with a Fourth Family

    SciTech Connect

    Chanowitz, Michael S.

    2009-04-22

    CKM mixing between third family quarks and a possible fourth family is constrained by global fits to the precision electroweak data. The dominant constraint is from nondecoupling oblique corrections rather than the vertex correction to Z {yields} {bar b}b used in previous analyses. The possibility of large mixing suggested by some recent analyses of FCNC processes is excluded, but 3-4 mixing of the same order as the Cabbibo mixing of the first two families is allowed.

  20. Mixed wasted integrated program: Logic diagram

    SciTech Connect

    Mayberry, J.; Stelle, S.; O`Brien, M.; Rudin, M.; Ferguson, J.; McFee, J.

    1994-11-30

    The Mixed Waste Integrated Program Logic Diagram was developed to provide technical alternative for mixed wastes projects for the Office of Technology Development`s Mixed Waste Integrated Program (MWIP). Technical solutions in the areas of characterization, treatment, and disposal were matched to a select number of US Department of Energy (DOE) treatability groups represented by waste streams found in the Mixed Waste Inventory Report (MWIR).

  1. A Call for Conducting Multivariate Mixed Analyses

    ERIC Educational Resources Information Center

    Onwuegbuzie, Anthony J.

    2016-01-01

    Several authors have written methodological works that provide an introductory- and/or intermediate-level guide to conducting mixed analyses. Although these works have been useful for beginning and emergent mixed researchers, with very few exceptions, works are lacking that describe and illustrate advanced-level mixed analysis approaches. Thus,…

  2. Entropy of Mixing of Distinguishable Particles

    ERIC Educational Resources Information Center

    Kozliak, Evguenii I.

    2014-01-01

    The molar entropy of mixing yields values that depend only on the number of mixing components rather than on their chemical nature. To explain this phenomenon using the logic of chemistry, this article considers mixing of distinguishable particles, thus complementing the well-known approach developed for nondistinguishable particles, for example,…

  3. Foam-Mixing-And-Dispensing Machine

    NASA Technical Reports Server (NTRS)

    Chong, Keith Y.; Toombs, Gordon R.; Jackson, Richard J.

    1996-01-01

    Time-and-money-saving machine produces consistent, homogeneously mixed foam, enhancing production efficiency. Automatically mixes and dispenses polyurethane foam in quantities specified by weight. Consists of cart-mounted, air-driven proportioning unit; air-activated mechanical mixing gun; programmable timer/counter, and controller.

  4. Entropy of Mixing of Distinguishable Particles

    ERIC Educational Resources Information Center

    Kozliak, Evguenii I.

    2014-01-01

    The molar entropy of mixing yields values that depend only on the number of mixing components rather than on their chemical nature. To explain this phenomenon using the logic of chemistry, this article considers mixing of distinguishable particles, thus complementing the well-known approach developed for nondistinguishable particles, for example,…

  5. Code Mixing and Modernization across Cultures.

    ERIC Educational Resources Information Center

    Kamwangamalu, Nkonko M.

    A review of recent studies addressed the functional uses of code mixing across cultures. Expressions of code mixing (CM) are not random; in fact, a number of functions of code mixing can easily be delineated, for example, the concept of "modernization.""Modernization" is viewed with respect to how bilingual code mixers perceive…

  6. Pragmatism, Evidence, and Mixed Methods Evaluation

    ERIC Educational Resources Information Center

    Hall, Jori N.

    2013-01-01

    Mixed methods evaluation has a long-standing history of enhancing the credibility of evaluation findings. However, using mixed methods in a utilitarian way implicitly emphasizes convenience over engaging with its philosophical underpinnings (Denscombe, 2008). Because of this, some mixed methods evaluators and social science researchers have been…

  7. Qualitative Approaches to Mixed Methods Practice

    ERIC Educational Resources Information Center

    Hesse-Biber, Sharlene

    2010-01-01

    This article discusses how methodological practices can shape and limit how mixed methods is practiced and makes visible the current methodological assumptions embedded in mixed methods practice that can shut down a range of social inquiry. The article argues that there is a "methodological orthodoxy" in how mixed methods is practiced…

  8. Mixed pneumoconiosis: silicosis, asbestosis, talcosis, and berylliosis.

    PubMed

    Mark, G J; Monroe, C B; Kazemi, H

    1979-06-01

    Mixed pneumoconiosis is pulmonary disease due to two or more inhaled mineral irritants. Chronic disease due to beryllium has not been a component of any described mixed pneumoconiosis. A man with occupational exposure to a combination of dusts developed severe pulmonary disease. Silicosis, talcosis, asbestosis, and berylliosis were all documented by an open biopsy of the lung. The varieties of mixed pneumoconiosis are summarized.

  9. Contact sensitization to Compositae mix in children.

    PubMed

    Belloni Fortina, Anna; Romano, Ilaria; Peserico, Andrea

    2005-11-01

    The prevalence of contact sensitization to Compositae mix was investigated in 641 consecutive children. Seventeen children (12 with atopic dermatitis) tested positive for Compositae mix. We suggest adding Compositae mix to a pediatric screening series when investigating airborne dermatitis in children with atopic dermatitis.

  10. Moments, Mixed Methods, and Paradigm Dialogs

    ERIC Educational Resources Information Center

    Denzin, Norman K.

    2010-01-01

    I reread the 50-year-old history of the qualitative inquiry that calls for triangulation and mixed methods. I briefly visit the disputes within the mixed methods community asking how did we get to where we are today, the period of mixed-multiple-methods advocacy, and Teddlie and Tashakkori's third methodological moment. (Contains 10 notes.)

  11. Foam-Mixing-And-Dispensing Machine

    NASA Technical Reports Server (NTRS)

    Chong, Keith Y.; Toombs, Gordon R.; Jackson, Richard J.

    1996-01-01

    Time-and-money-saving machine produces consistent, homogeneously mixed foam, enhancing production efficiency. Automatically mixes and dispenses polyurethane foam in quantities specified by weight. Consists of cart-mounted, air-driven proportioning unit; air-activated mechanical mixing gun; programmable timer/counter, and controller.

  12. Moments, Mixed Methods, and Paradigm Dialogs

    ERIC Educational Resources Information Center

    Denzin, Norman K.

    2010-01-01

    I reread the 50-year-old history of the qualitative inquiry that calls for triangulation and mixed methods. I briefly visit the disputes within the mixed methods community asking how did we get to where we are today, the period of mixed-multiple-methods advocacy, and Teddlie and Tashakkori's third methodological moment. (Contains 10 notes.)

  13. Teaching Vocabulary through Code-Mixing.

    ERIC Educational Resources Information Center

    Celik, Mehmet

    2003-01-01

    Examined code-mixing, a little-known technique used in teaching vocabulary. Found that using code-mixing to introduce new vocabulary can be an efficient and effective method. Discusses procedures and cognitive processes involved in vocabulary learning and explains the use of code mixing to introduce vocabulary. (Author/VWL)

  14. Qualitative Approaches to Mixed Methods Practice

    ERIC Educational Resources Information Center

    Hesse-Biber, Sharlene

    2010-01-01

    This article discusses how methodological practices can shape and limit how mixed methods is practiced and makes visible the current methodological assumptions embedded in mixed methods practice that can shut down a range of social inquiry. The article argues that there is a "methodological orthodoxy" in how mixed methods is practiced…

  15. Manpower Mix for Health Services

    PubMed Central

    Shuman, Larry J.; Young, John P.; Naddor, Eliezer

    1971-01-01

    A model is formulated to determine the mix of manpower and technology needed to provide health services of acceptable quality at a minimum total cost to the community. Total costs include both the direct costs associated with providing the services and with developing additional manpower and the indirect costs (shortage costs) resulting from not providing needed services. The model is applied to a hypothetical neighborhood health center, and its sensitivity to alternative policies is investigated by cost-benefit analyses. Possible extensions of the model to include dynamic elements in health delivery systems are discussed, as is its adaptation for use in hospital planning, with a changed objective function. PMID:5095652

  16. Thin film mixed potential sensors

    DOEpatents

    Garzon, Fernando H.; Brosha, Eric L.; Mukundan, Rangachary

    2007-09-04

    A mixed potential sensor for oxidizable or reducible gases and a method of making. A substrate is provided and two electrodes are formed on a first surface of the substrate, each electrode being formed of a different catalytic material selected to produce a differential voltage between the electrodes from electrochemical reactions of the gases catalyzed by the electrode materials. An electrolytic layer of an electrolyte is formed over the electrodes to cover a first portion of the electrodes from direct exposure to the gases with a second portion of the electrodes uncovered for direct exposure to the gases.

  17. [Short history of mixed states].

    PubMed

    Cermolacce, M; Belzeaux, R; Corréard, N; Dassa, D; Dubois, M; Micoulaud-Franchi, J-A; Pringuey, D; Fakra, E; Maurel, M; Azorin, J-M

    2013-12-01

    The notion of mixed states is classically associated with descriptions and categories inherited from Kraepelin. However, simultaneous descriptions of depressive and manic manifestations can be traced back to ancient times. Semiology and definitions of these clinical associations have evolved across the times. We provide here a short insight on four distinct periods: Greek authors from ancient times, pre-Kraepelinian psychiatry (18th and 19th centuries), Kraepelin's conceptualization, and contemporary psychiatry (20th and 21st centuries). Copyright © 2013 Sociedade Brasileira de Farmacognosia. Published by Elsevier Masson SAS.. All rights reserved.

  18. Ergodicity and mixing in quantum dynamics

    NASA Astrophysics Data System (ADS)

    Zhang, Dongliang; Quan, H. T.; Wu, Biao

    2016-08-01

    After a brief historical review of ergodicity and mixing in dynamics, particularly in quantum dynamics, we introduce definitions of quantum ergodicity and mixing using the structure of the system's energy levels and spacings. Our definitions are consistent with the usual understanding of ergodicity and mixing. Two parameters concerning the degeneracy in energy levels and spacings are introduced. They are computed for right triangular billiards and the results indicate a very close relation between quantum ergodicity (mixing) and quantum chaos. At the end, we argue that, besides ergodicity and mixing, there may exist a third class of quantum dynamics which is characterized by a maximized entropy.

  19. Mixed Strategies in cyclic competition

    NASA Astrophysics Data System (ADS)

    Intoy, Ben; Pleimling, Michel

    2015-03-01

    Physicists have been using evolutionary game theory to model and simulate cyclically competing species, with applications to lizard mating strategies and competing bacterial strains. However these models assume that each agent plays the same strategy, which is called a pure strategy in game theory, until they are beaten by a better strategy which they immediately adopt. We relax this constraint of an agent playing a single strategy by instead letting the agent pick its strategy randomly from a probability distribution, which is called a mixed strategy in game theory. This scheme is very similar to multiple occupancy models seen in the literature, the major difference being that interactions happen between sites rather than within them. Choosing strategies out of a distribution also has applications to economic/social systems such as the public goods game. We simulate a model of mixed strategy and cylic competition on a one-dimensional lattice with three and four strategies and find interesting spatial and stability properties depending on how discretized the choice of strategy is for the agents. This work is supported by the US National Science Foundation through Grant DMR-1205309.

  20. Mixing stops at the LHC

    SciTech Connect

    Agrawal, Prateek; Frugiuele, Claudia

    2014-01-01

    We study the phenomenology of a light stop NLSP in the presence of large mixing with either the first or the second generation. R-symmetric models provide a prime setting for this scenario, but our discussion also applies to the MSSM when a significant amount of mixing can be accommodated. In our framework the dominant stop decay is through the flavor violating mode into a light jet and the LSP in an extended region of parameter space. There are currently no limits from ATLAS and CMS in this region. We emulate shape-based hadronic SUSY searches for this topology, and find that they have potential sensitivity. If the extension of these analyses to this region is robust, we find that these searches can set strong exclusion limits on light stops. If not, then the flavor violating decay mode is challenging and may represent a blind spot in stop searches even at 13 TeV. Thus, an experimental investigation of this scenario is well motivated.

  1. Tracer mixing at fracture intersections

    SciTech Connect

    Li, Guomin

    2001-02-10

    Discrete network models are one of the approaches used to simulate a dissolved contaminant, which is usually represented as a tracer in modeling studies, in fractured rocks. The discrete models include large numbers of individual fractures within the network structure, with flow and transport described on the scale of an individual fracture. Numerical simulations for the mixing characteristics and transfer probabilities of a tracer through a fracture intersection are performed for this study. A random-walk, particle-tracking model is applied to simulate tracer transport in fracture intersections by moving particles through space using individual advective and diffusive steps. The simulation results are compared with existing numerical and analytical solutions for a continuous intersection over a wide range of Peclet numbers. This study attempts to characterize the relative concentration at the outflow branches for a continuous intersection with different flow fields. The simulation results demonstrate that the mixing characteristics at the fracture intersections are a function not only of the Peclet number but also of the flow field pattern.

  2. Nanoscale Mixing of Soft Solids

    SciTech Connect

    Choi, Soo-Hyung; Lee, Sangwoo; Soto, Haidy E.; Lodge, Timothy P.; Bates, Frank S.

    2013-03-07

    Assessing the state of mixing on the molecular scale in soft solids is challenging. Concentrated solutions of micelles formed by self-assembly of polystyrene-block-poly(ethylene-alt-propylene) (PS-PEP) diblock copolymers in squalane (C{sub 30}H{sub 62}) adopt a body-centered cubic (bcc) lattice, with glassy PS cores. Utilizing small-angle neutron scattering (SANS) and isotopic labeling ({sup 1}H and {sup 2}H (D) polystyrene blocks) in a contrast-matching solvent (a mixture of squalane and perdeuterated squalane), we demonstrate quantitatively the remarkable fact that a commercial mixer can create completely random mixtures of micelles with either normal, PS(H), or deuterium-labeled, PS(D), cores on a well-defined bcc lattice. The resulting SANS intensity is quantitatively modeled by the form factor of a single spherical core. These results demonstrate both the possibility of achieving complete nanoscale mixing in a soft solid and the use of SANS to quantify the randomness.

  3. Can whales mix the ocean?

    NASA Astrophysics Data System (ADS)

    Lavery, T. J.; Roudnew, B.; Seuront, L.; Mitchell, J. G.; Middleton, J.

    2012-07-01

    Ocean mixing influences global climate and enhances primary productivity by transporting nutrient rich water into the euphotic zone. The contribution of the swimming biosphere to diapycnal mixing in the ocean has been hypothesised to occur on scales similar to that of tides or winds, however, the extent to which this contributes to nutrient transport and stimulates primary productivity has not been explored. Here, we introduce a novel method to estimate the diapycnal diffusivity that occurs as a result of a sperm whale swimming through a pycnocline. Nutrient profiles from the Hawaiian Ocean are used to further estimate the amount of nitrogen transported into the euphotic zone and the primary productivity stimulated as a result. We estimate that the 80 sperm whales that travel through an area of 104 km2 surrounding Hawaii increase diapycnal diffusivity by 10-6 m2 s-1 which results in the flux of 105 kg of nitrogen into the euphotic zone each year. This nitrogen input subsequently stimulates 6 × 105 kg of carbon per year. The nutrient input of swimming sperm whales is modest compared to dominant modes of nutrient transport such as nitrogen fixation but occurs more consistently and thus may provide the nutrients necessary to enable phytoplankton growth and survival in the absence of other seasonal and daily nutrient inputs.

  4. Mixing in straight shear layers

    NASA Technical Reports Server (NTRS)

    Karasso, P. S.; Mungal, M. G.

    1992-01-01

    Planar laser-induced fluorescence measurements were performed in a liquid plane mixing layer to extract the probability density function (pdf) of the mixture fraction of a passive scalar across the layer. Three Reynolds number (Re) cases were studied, 10,000, 33,000 and 90,000, with Re based on velocity difference and visual thickness. The results show that a non-marching pdf (central hump invariant from edge to edge of the layer) exists for Re = 10,000 but that a marching type pdf characterizes the Re = 33,000 and Re = 90,000 cases. For all cases, a broad range of mixture fraction values is found at each location across the layer. Streamwise and spanwise ramps across the layer, and structure-to-structure variation were observed and are believed to be responsible for the above behavior of the composition field. Tripping the boundary layer on the high-speed side of the splitter plate for each of the above three cases resulted in increased three-dimensionality and a change in the composition field. Average and average mixed fluid compositions are reported for all cases.

  5. [Mixed states: evolution of classifications].

    PubMed

    Pringuey, D; Cherikh, F; Giordana, B; Fakra, E; Dassa, D; Cermolacce, M; Belzeaux, R; Maurel, M; Azorin, J-M

    2013-12-01

    The nosological position of mixed states has followed the course of classifying methods in psychiatry, the steps of the invention of the clinic, progress in the organization of care, including the discoveries of psychopharmacology. The clinical observation of a mixture of symptoms emerging from usually opposite clinical conditions is classical. In the 70s, a syndromic specification fixed the main symptom combinations but that incongruous assortment failed to stabilize the nosological concept. Then stricter criteriology was proposed. To be too restrictive, a consensus operates a dimensional opening that attempts to meet the pragmatic requirements of nosology validating the usefulness of the class system. This alternation between rigor of categorization and return to a more flexible criteriological option reflects the search for the right balance between nosology and diagnosis. The definition of mixed states is best determined by their clinical and prognostic severity, related to the risk of suicide, their lower therapeutic response, the importance of their psychiatric comorbidities, anxiety, emotional lability, alcohol abuse. Trying to compensate for the lack of categorical definitions and better reflecting the clinical field problems, new definitions complement criteriology with dimensional aspects, particularly taking into account temperaments.

  6. Mixed waste characterization reference document

    SciTech Connect

    1997-09-01

    Waste characterization and monitoring are major activities in the management of waste from generation through storage and treatment to disposal. Adequate waste characterization is necessary to ensure safe storage, selection of appropriate and effective treatment, and adherence to disposal standards. For some wastes characterization objectives can be difficult and costly to achieve. The purpose of this document is to evaluate costs of characterizing one such waste type, mixed (hazardous and radioactive) waste. For the purpose of this document, waste characterization includes treatment system monitoring, where monitoring is a supplement or substitute for waste characterization. This document establishes a cost baseline for mixed waste characterization and treatment system monitoring requirements from which to evaluate alternatives. The cost baseline established as part of this work includes costs for a thermal treatment technology (i.e., a rotary kiln incinerator), a nonthermal treatment process (i.e., waste sorting, macronencapsulation, and catalytic wet oxidation), and no treatment (i.e., disposal of waste at the Waste Isolation Pilot Plant (WIPP)). The analysis of improvement over the baseline includes assessment of promising areas for technology development in front-end waste characterization, process equipment, off gas controls, and monitoring. Based on this assessment, an ideal characterization and monitoring configuration is described that minimizes costs and optimizes resources required for waste characterization.

  7. Mixing stops at the LHC

    DOE PAGES

    Agrawal, Prateek; Frugiuele, Claudia

    2014-01-01

    We study the phenomenology of a light stop NLSP in the presence of large mixing with either the first or the second generation. R-symmetric models provide a prime setting for this scenario, but our discussion also applies to the MSSM when a significant amount of mixing can be accommodated. In our framework the dominant stop decay is through the flavor violating mode into a light jet and the LSP in an extended region of parameter space. There are currently no limits from ATLAS and CMS in this region. We emulate shape-based hadronic SUSY searches for this topology, and find thatmore » they have potential sensitivity. If the extension of these analyses to this region is robust, we find that these searches can set strong exclusion limits on light stops. If not, then the flavor violating decay mode is challenging and may represent a blind spot in stop searches even at 13 TeV. Thus, an experimental investigation of this scenario is well motivated.« less

  8. Collaboration Patterns as a Function of Article Genre among Mixed Researchers: A Mixed Methods Bibliometric Study

    ERIC Educational Resources Information Center

    Jordan, John; Wachsmann, Melanie; Hoisington, Susan; Gonzalez, Vanessa; Valle, Rachel; Lambert, Jarod; Aleisa, Majed; Wilcox, Rachael; Benge, Cindy L.; Onwuegbuzie, Anthony J.

    2017-01-01

    Surprisingly, scant information exists regarding the collaboration patterns of mixed methods researchers. Thus, the purpose of this mixed methods bibliometric study was to examine (a) the distribution of the number of co-authors in articles published in the flagship mixed methods research journal (i.e., "Journal of Mixed Methods…

  9. Diffusion in mixed solvents. II - The heat of mixing parameter

    NASA Technical Reports Server (NTRS)

    Carapellucci, P. A.

    1975-01-01

    Correlation of second-order rate constants for many reactions involving electron transfer between organic molecules, solvated electron reactions, iodine diffusion coefficients, and triplet state electron transfer reactions has been made with the heat of mixing parameter (HMP) for the aqueous binary solvent systems. The aqueous binary solvents studied are those containing methanol or ethanol (type I solvent); 1-propanol or tert-butyl alcohol (type II solvent); or sucrose or glycerol (type III solvent). A plot of the HMP vs. the diffusion parameter for each reaction yields superimposable curves for these reactions in a particular solvent mixture over the entire solvent mixture range, irrespective of the value of the reaction's rate constant or diffusion coefficient in water.

  10. Diffusion in mixed solvents. II - The heat of mixing parameter

    NASA Technical Reports Server (NTRS)

    Carapellucci, P. A.

    1975-01-01

    Correlation of second-order rate constants for many reactions involving electron transfer between organic molecules, solvated electron reactions, iodine diffusion coefficients, and triplet state electron transfer reactions has been made with the heat of mixing parameter (HMP) for the aqueous binary solvent systems. The aqueous binary solvents studied are those containing methanol or ethanol (type I solvent); 1-propanol or tert-butyl alcohol (type II solvent); or sucrose or glycerol (type III solvent). A plot of the HMP vs. the diffusion parameter for each reaction yields superimposable curves for these reactions in a particular solvent mixture over the entire solvent mixture range, irrespective of the value of the reaction's rate constant or diffusion coefficient in water.

  11. PREFACE: Turbulent Mixing and Beyond Turbulent Mixing and Beyond

    NASA Astrophysics Data System (ADS)

    Abarzhi, Snezhana I.; Gauthier, Serge; Rosner, Robert

    2008-10-01

    The goals of the International Conference `Turbulent Mixing and Beyond' are to expose the generic problem of Turbulence and Turbulent Mixing in Unsteady Flows to a wide scientific community, to promote the development of new ideas in tackling the fundamental aspects of the problem, to assist in the application of novel approaches in a broad range of phenomena, where the non-canonical turbulent processes occur, and to have a potential impact on technology. The Conference provides the opportunity to bring together scientists from the areas which include, but are not limited to, high energy density physics, plasmas, fluid dynamics, turbulence, combustion, material science, geophysics, astrophysics, optics and telecommunications, applied mathematics, probability and statistics, and to have their attention focused on the long-standing formidable task. The Turbulent Mixing and Turbulence in Unsteady Flows, including multiphase flows, plays a key role in a wide variety of phenomena, ranging from astrophysical to nano-scales, under either high or low energy density conditions. Inertial confinement and magnetic fusion, light-matter interaction and non-equilibrium heat transfer, properties of materials under high strain rates, strong shocks, explosions, blast waves, supernovae and accretion disks, stellar non-Boussinesq and magneto-convection, planetary interiors and mantle-lithosphere tectonics, premixed and non-premixed combustion, oceanography, atmospheric flows, unsteady boundary layers, hypersonic and supersonic flows, are a few examples to list. A grip on unsteady turbulent processes is crucial for cutting-edge technology such as laser-micromachining and free-space optical telecommunications, and for industrial applications in aeronautics. Unsteady Turbulent Processes are anisotropic, non-local and multi-scale, and their fundamental scaling, spectral and invariant properties depart from the classical Kolmogorov scenario. The singular aspects and similarity of the

  12. A Darwinian mechanism for biogenic ocean mixing

    NASA Astrophysics Data System (ADS)

    Katija, Kakani; Dabiri, John

    2009-11-01

    Recent observations of biogenic turbulence in the ocean have led to conflicting ideas regarding the contribution of animal swimming to ocean mixing. Previous measurements indicate elevated turbulent dissipation in the vicinity of large populations of planktonic animals swimming in concert. However, elevated turbulent dissipation is by itself insufficient proof of substantial biogenic mixing. We conducted field measurements of mixing efficiency by individual Mastigias sp. (a Palauan jellyfish) using a self-contained underwater velocimetry apparatus. These measurements revealed another mechanism that contributes to animal mixing besides wake turbulence. This mechanism was first described by Sir Charles Galton Darwin and is in fact the dominant mechanism of mixing by swimming animals. The efficiency of Darwin's mechanism (or drift) is dependent on animal shape rather than fluid length scale and, unlike turbulent wake mixing, is enhanced by the fluid viscosity. Therefore, it provides a means of biogenic mixing that can be equally effective in small plankton and large mammals.

  13. Expandable mixing section gravel and cobble eductor

    DOEpatents

    Miller, Arthur L.; Krawza, Kenneth I.

    1997-01-01

    In a hydraulically powered pump for excavating and transporting slurries in hich it is immersed, the improvement of a gravel and cobble eductor including an expandable mixing section, comprising: a primary flow conduit that terminates in a nozzle that creates a water jet internal to a tubular mixing section of the pump when water pressure is applied from a primary supply flow; a tubular mixing section having a center line in alignment with the nozzle that creates a water jet; a mixing section/exit diffuser column that envelopes the flexible liner; and a secondary inlet conduit that forms an opening at a bas portion of the column and adjacent to the nozzle and water jet to receive water saturated gravel as a secondary flow that mixes with the primary flow inside of the mixing section to form a combined total flow that exits the mixing section and decelerates in the exit diffuser.

  14. Differences in bone-cement porosity by vacuum mixing, centrifugation, and hand mixing.

    PubMed

    Macaulay, William; DiGiovanni, Christopher W; Restrepo, Andres; Saleh, Khaled J; Walsh, Heather; Crossett, Lawrence S; Peterson, Margaret G E; Li, Stephen; Salvati, Eduardo A

    2002-08-01

    The mean pore size and percent porosity of vacuum-mixed cement were compared with centrifuged cement and cement hand mixed by skilled specialized operating room technicians. Centrifuged cement samples had the smallest mean pore size when compared with vacuum-mixed specimens. The mean pore size for the hand-mixed specimens was intermediate and not significantly different from the other 2 mixing techniques. Results were reversed, however, for mean percent porosity. Centrifuged cement had the highest percent porosity; vacuum-mixed cement, the lowest; and hand-mixed cement, intermediate. The porosity of vacuum-mixed Simplex P (Howmedica, Rutherford, NJ) bone-cement was similar from the initial to the remnant cement extruded from the cement gun. There was no reduced cement porosity with vacuum mixing or centrifugation as anticipated. Reversion to hand mixing by highly skilled technicians could result in a significant cost savings without negative effects on cement porosity.

  15. Microgravity acoustic mixing for particle cloud combustors

    NASA Technical Reports Server (NTRS)

    Pla, Frederic; Rubinstein, Robert I.

    1990-01-01

    Experimental and theoretical investigations of acoustic mixing procedures designed to uniformly distribute fuel particles in a combustion tube for application in the proposed Particle Cloud Combustion Experiment (PCCE) are described. Two acoustic mixing methods are investigated: mixing in a cylindrical tube using high frequency spinning modes generated by suitably phased, or quadrature speakers, and acoustic premixing in a sphere. Quadrature mixing leads to rapid circumferential circulation of the powder around the tube. Good mixing is observed in the circulating regions. However, because axial inhomogeneities are necessarily present in the acoustic field, this circulation does not extend throughout the tube. Simultaneous operation of the quadrature-speaker set and the axial-speaker was observed to produce considerably enhanced mixing compared to operation of the quadrature-speaker set alone. Mixing experiments using both types of speakers were free of the longitudinal powder drift observed using axial-speakers alone. Vigorous powder mixing was obtained in the sphere for many normal modes: however, in no case was the powder observed to fill the sphere entirely. Theoretical analysis indicated that mixing under steady conditions cannot fill more than a hemisphere except under very unusual conditions. Premixing in a hemisphere may be satisfactory; otherwise, complete mixing in microgravity might be possible by operating the speaker in short bursts. A general conclusion is that acoustic transients are more likely to produce good mixing than steady state conditions. The reason is that in steady conditions, flow structures like nodal planes are possible and often even unavoidable. These tend to separate the mixing region into cells across which powder cannot be transferred. In contrast, transients not only are free of such structures, they also have the characteristics, desirable for mixing, of randomness and disorder. This conclusion is corroborated by mixing

  16. Flavor mixings in flux compactifications

    NASA Astrophysics Data System (ADS)

    Buchmuller, Wilfried; Schweizer, Julian

    2017-04-01

    A multiplicity of quark-lepton families can naturally arise as zero modes in flux compactifications. The flavor structure of quark and lepton mass matrices is then determined by the wave function profiles of the zero modes. We consider a supersymmetric S O (10 )×U (1 ) model in six dimensions compactified on the orbifold T2/Z2 with Abelian magnetic flux. A bulk 16 -plet charged under the U (1 ) provides the quark-lepton generations whereas two uncharged 10 -plets yield two Higgs doublets. Bulk anomaly cancellation requires the presence of additional 16 - and 10 -plets. The corresponding zero modes form vectorlike split multiplets that are needed to obtain a successful flavor phenomenology. We analyze the pattern of flavor mixings for the two heaviest families of the Standard Model and discuss possible generalizations to three and more generations.

  17. Seasoning mixed-oak fuelwood

    SciTech Connect

    McKiel, C.G.; Husband, T.P.

    1986-01-01

    In trials in Rhode Island, logs of Quercus velutina and Q. alba were cut into 18-inch lengths, split if diameter is greater than 5 inches and stacked in racks with plywood sides to simulate a continuous stack. Racks were shaded or unshaded, and with or without weather protection. Trials were started on six dates during September 1978 - April 1980. Storage racks were weighed monthly and apparent percentage moisture was calculated assuming that all weight changes resulted from water loss. From the results it was concluded that weather protection with good air circulation is desirable for seasoning mixed-oak fuelwood. Cutting in spring or early summer gives faster initial drying than cutting in autumn or winter, but is unlikely to result in 20% moisture content by the following heating season. Without protection, moisture content less than 30% are unlikely. Shade locations resulted in slower drying rates. 3 references.

  18. Mediterranean outflow mixing and dynamics.

    PubMed

    Price, J F; Baringer, M O; Lueck, R G; Johnson, G C; Ambar, I; Parrilla, G; Cantos, A; Kennelly, M A; Sanford, T B

    1993-02-26

    The Mediterranean Sea produces a salty, dense outflow that is strongly modified by entrainment as it first begins to descend the continental slope in the eastern Gulf of Cadiz. The current accelerates to 1.3 meters per second, which raises the internal Froude number above 1, and is intensely turbulent through its full thickness. The outflow loses about half of its density anomaly and roughly doubles its volume transport as it entrains less saline North Atlantic Central water. Within 100 kilometers downstream, the current is turned by the Coriolis force until it flows nearly parallel to topography in a damped geostrophic balance. The mixed Mediterranean outflow continues westward, slowly descending the continental slope until it becomes neutrally buoyant in the thermocline where it becomes an important water mass.

  19. Mixing in SRS Closure Business Unit Applications

    SciTech Connect

    POIRIER, MICHAELR.

    2004-06-23

    The following equipment is commonly used to mix fluids: mechanical agitators, jets (pumps), shrouded axial impeller mixers (Flygt mixers), spargers, pulsed jet mixers, boiling, static mixers, falling films, liquid sprays, and thermal convection. This discussion will focus on mechanical agitators, jets, shrouded axial impeller mixers, spargers, and pulsed jet mixers, as these devices are most likely to be employed in Savannah River Site (SRS) Closure Business applications. In addressing mixing problems in the SRS Tank Farm, one must distinguish between different mixing objectives. These objectives include sludge mixing (e.g., Extended Sludge Processing), sludge retrieval (e.g., sludge transfers between tanks), heel retrieval (e.g., Tanks 18F and 19F), chemical reactions (e.g., oxalic acid neutralization) and salt dissolution. For example, one should not apply sludge mixing guidelines to heel removal applications. Mixing effectiveness is a function of both the mixing device (e.g., slurry pump, agitator, air sparger) and the properties of the material to be mixed (e.g., yield stress, viscosity, density, and particle size). The objective of this document is to provide background mixing knowledge for the SRS Closure Business Unit personnel and to provide general recommendations for mixing in SRS applications.

  20. Extrusion-mixing compared with hand-mixing of polyether impression materials?

    PubMed

    McMahon, Caroline; Kinsella, Daniel; Fleming, Garry J P

    2010-12-01

    The hypotheses tested were two-fold (a) whether altering the base:catalyst ratio influences working time, elastic recovery and strain in compression properties of a hand-mixed polyether impression material and (b) whether an extrusion-mixed polyether impression material would have a significant advantage over a hand-mixed polyether impression material mixed to the optimum base:catalyst ratio. The polyether was hand-mixed at the optimum (manufacturers recommended) base:catalyst ratios (7:1) and further groups were made by increasing or decreasing the catalyst length by 25%. Additionally specimens were also made from an extrusion-mixed polyether impression material and compared with the optimum hand-mixed base:catalyst ratio. A penetrometer assembly was used to measure the working time (n=5). Five cylindrical specimens for each hand-mixed and extrusion mixed group investigated were employed for elastic recovery and strain in compression testing. Hand-mixing polyether impression materials with 25% more catalyst than that recommended significantly decreased the working time while hand-mixing with 25% less catalyst than that recommended significantly increased the strain in compression. The extrusion-mixed polyether impression material provided similar working time, elastic recovery and strain in compression to the hand-mixed polyether mixed at the optimum base:catalyst ratio.

  1. Investigation on flow and mixing characteristics of supersonic mixing layer induced by forced vibration of cantilever

    NASA Astrophysics Data System (ADS)

    Zhang, Dongdong; Tan, Jianguo; Lv, Liang

    2015-12-01

    The mixing process has been an important issue for the design of supersonic combustion ramjet engine, and the mixing efficiency plays a crucial role in the improvement of the combustion efficiency. In the present study, nanoparticle-based planar laser scattering (NPLS), particle image velocimetry (PIV) and large eddy simulation (LES) are employed to investigate the flow and mixing characteristics of supersonic mixing layer under different forced vibration conditions. The indexes of fractal dimension, mixing layer thickness, momentum thickness and scalar mixing level are applied to describe the mixing process. Results show that different from the development and evolution of supersonic mixing layer without vibration, the flow under forced vibration is more likely to present the characteristics of three-dimensionality. The laminar flow region of mixing layer under forced vibration is greatly shortened and the scales of rolled up Kelvin-Helmholtz vortices become larger, which promote the mixing process remarkably. The fractal dimension distribution reveals that comparing with the flow without vibration, the turbulent fluctuation of supersonic mixing layer under forced vibration is more intense. Besides, the distribution of mixing layer thickness, momentum thickness and scalar mixing level are strongly influenced by forced vibration. Especially, when the forcing frequency is 4000 Hz, the mixing layer thickness and momentum thickness are 0.0391 m and 0.0222 m at the far field of 0.16 m, 83% and 131% higher than that without vibration at the same position, respectively.

  2. Mercury removal from solid mixed waste

    SciTech Connect

    Gates, D.D.; Morrissey, M.; Chava, K.K.; Chao, K.

    1994-12-31

    The removal of mercury from mixed wastes is an essential step in eliminating the temporary storage of large inventories of mixed waste throughout the Department of Energy (DOE) complex. Currently thermal treatment has been identified as a baseline technology and is being developed as part of the DOE Mixed Waste Integrated Program (MWIP). Since thermal treatment will not be applicable to all mercury containing mixed waste and the removal of mercury prior to thermal treatment may be desirable, laboratory studies have been initiated at Oak Ridge National Laboratory (ORNL) to develop alternative remediation technologies capable of removing mercury from certain mixed waste. This paper describes laboratory investigations of the KI/I{sub 2} leaching processes to determine the applicability of this process to mercury containing solid mixed waste.

  3. Droplet mixers: Microfluidics, mixing measures and optimization

    NASA Astrophysics Data System (ADS)

    Stone, Zachary; Stone, Howard

    2003-11-01

    Rapid mixing is essential in a variety of microfluidic applications but is often difficult to achieve at low Reynolds numbers. Inspired by a recently developed microdevice that mixes reagents in droplets, which simply flow along a periodic serpentine channel (Song, Tice and Ismagilov, 2003), we investigate a model ``droplet mixer". The model consists of a spherical droplet immersed in a periodic sequence of distinct external flows, which are superpositions of uniform and shear flows. We label the fluid inside the droplet with two colors and visualize mixing with a method we call ``backtrace imaging", which allows us to render cross-sections of the droplet at arbitrary times during the mixing cycle. To analyze our results, we present a simple measure of mixing, which allows us to locate sets of parameters that optimize mixing over a small number of flow cycles. We also consider shear flows in multiple directions and the effect of random variations in the durations of external flows.

  4. Electrothermal blinking vortices for chaotic mixing

    NASA Astrophysics Data System (ADS)

    Loire, Sophie; Kauffmann, Paul; Gimenez, Paul; Meinhart, Carl; Mezic, Igor

    2012-11-01

    We present an experimental and theoretical study of electrothermal chaotic mixing using blinking of asymmetric 2D electrothermal vortices. Electrothermal flows are modelled with 2D finite element method using COMSOL software based on an enhanced electrothermal model. Velocities in top-view and side-view devices are measured by micro particle image velocimetry (μPIV). The experimentally reconstructed velocity profile shows a dramatic asymmetry between the two vortices, in good agreement with the FEM model. The separation line between the two vortices is shifted and tilted making the blinking vortices overlap. We use the mix-variance coefficient (MVC) on experimental particle detection data and numerical trajectory simulations to evaluate mixing at different scales including the layering of fluid interfaces by the flow, a keypoint for efficient mixing. The blinking vortices method greatly improve mixing efficiency. Theoretical, experimental and simulation results of the mixing process will be presented.

  5. Children's understanding and experience of mixed emotions.

    PubMed

    Larsen, Jeff T; To, Yen M; Fireman, Gary

    2007-02-01

    Though some models of emotion contend that happiness and sadness are mutually exclusive in experience, recent findings suggest that adults can feel happy and sad at the same time in emotionally complex situations. Other research has shown that children develop a better conceptual understanding of mixed emotions as they grow older, but no research has examined children's actual experience of mixed emotions. To examine developmental differences in the experience of mixed emotions, we showed children ages 5 to 12 scenes from an animated film that culminated with a father and daughter's bittersweet farewell. In subsequent interviews, older children were more likely than younger children to report experiencing mixed emotions. These results suggest that in addition to having a better conceptual understanding of mixed emotions, older children are more likely than younger children to actually experience mixed emotions in emotionally complex situations.

  6. Quantifying uncertainty in stable isotope mixing models

    DOE PAGES

    Davis, Paul; Syme, James; Heikoop, Jeffrey; ...

    2015-05-19

    Mixing models are powerful tools for identifying biogeochemical sources and determining mixing fractions in a sample. However, identification of actual source contributors is often not simple, and source compositions typically vary or even overlap, significantly increasing model uncertainty in calculated mixing fractions. This study compares three probabilistic methods, SIAR [Parnell et al., 2010] a pure Monte Carlo technique (PMC), and Stable Isotope Reference Source (SIRS) mixing model, a new technique that estimates mixing in systems with more than three sources and/or uncertain source compositions. In this paper, we use nitrate stable isotope examples (δ15N and δ18O) but all methods testedmore » are applicable to other tracers. In Phase I of a three-phase blind test, we compared methods for a set of six-source nitrate problems. PMC was unable to find solutions for two of the target water samples. The Bayesian method, SIAR, experienced anchoring problems, and SIRS calculated mixing fractions that most closely approximated the known mixing fractions. For that reason, SIRS was the only approach used in the next phase of testing. In Phase II, the problem was broadened where any subset of the six sources could be a possible solution to the mixing problem. Results showed a high rate of Type I errors where solutions included sources that were not contributing to the sample. In Phase III some sources were eliminated based on assumed site knowledge and assumed nitrate concentrations, substantially reduced mixing fraction uncertainties and lowered the Type I error rate. These results demonstrate that valuable insights into stable isotope mixing problems result from probabilistic mixing model approaches like SIRS. The results also emphasize the importance of identifying a minimal set of potential sources and quantifying uncertainties in source isotopic composition as well as demonstrating the value of additional information in reducing the uncertainty in calculated

  7. Lagrangian Mixing in an Axisymmetric Hurricane Model

    DTIC Science & Technology

    2010-07-23

    particle integration, and are computed for nonlocal regions. The global measures of mixing derived from finite-time Lyapunov exponents , rel- ative...mixing derived from finite-time Lyapunov exponents , relative dispersion, and a measured mixing rate are applied to distinct regions representing...field varies slowly both in space and time. Some of the local techniques currently in use are finite-time Lyapunov exponents , (Haller, 2002; Haller

  8. Quantifying uncertainty in stable isotope mixing models

    SciTech Connect

    Davis, Paul; Syme, James; Heikoop, Jeffrey; Fessenden-Rahn, Julianna; Perkins, George; Newman, Brent; Chrystal, Abbey E.; Hagerty, Shannon B.

    2015-05-19

    Mixing models are powerful tools for identifying biogeochemical sources and determining mixing fractions in a sample. However, identification of actual source contributors is often not simple, and source compositions typically vary or even overlap, significantly increasing model uncertainty in calculated mixing fractions. This study compares three probabilistic methods, SIAR [Parnell et al., 2010] a pure Monte Carlo technique (PMC), and Stable Isotope Reference Source (SIRS) mixing model, a new technique that estimates mixing in systems with more than three sources and/or uncertain source compositions. In this paper, we use nitrate stable isotope examples (δ15N and δ18O) but all methods tested are applicable to other tracers. In Phase I of a three-phase blind test, we compared methods for a set of six-source nitrate problems. PMC was unable to find solutions for two of the target water samples. The Bayesian method, SIAR, experienced anchoring problems, and SIRS calculated mixing fractions that most closely approximated the known mixing fractions. For that reason, SIRS was the only approach used in the next phase of testing. In Phase II, the problem was broadened where any subset of the six sources could be a possible solution to the mixing problem. Results showed a high rate of Type I errors where solutions included sources that were not contributing to the sample. In Phase III some sources were eliminated based on assumed site knowledge and assumed nitrate concentrations, substantially reduced mixing fraction uncertainties and lowered the Type I error rate. These results demonstrate that valuable insights into stable isotope mixing problems result from probabilistic mixing model approaches like SIRS. The results also emphasize the importance of identifying a minimal set of potential sources and quantifying uncertainties in source isotopic composition as well as demonstrating the value of additional information in reducing the

  9. Cowles Dissolver Fire Involving IR Flare Mix

    DTIC Science & Technology

    1994-08-01

    fluoroethylene (PTFE), and a fluoroelastomer binder dissolved in acetone. Hexane is used to precipitate the binder and wash the mix. During the wash...ethylene (PTFE), and a fluoroelastomer binder. The fluoroelastomer binder is dissolved in acetone before the mix is made. The PTFE and magnesium...the binder precipitates on the surface of the suspended particles. The solids are allowed to settle and the liquid is siphoned from the mix bowl

  10. Optimal Control of Evolution Mixed Variational Inclusions

    SciTech Connect

    Alduncin, Gonzalo

    2013-12-15

    Optimal control problems of primal and dual evolution mixed variational inclusions, in reflexive Banach spaces, are studied. The solvability analysis of the mixed state systems is established via duality principles. The optimality analysis is performed in terms of perturbation conjugate duality methods, and proximation penalty-duality algorithms to mixed optimality conditions are further presented. Applications to nonlinear diffusion constrained problems as well as quasistatic elastoviscoplastic bilateral contact problems exemplify the theory.

  11. Mechanisms of tolerance induced via mixed chimerism.

    PubMed

    Sykes, Megan

    2007-05-01

    Mixed hematopoietic chimerism provides a powerful means of inducing robust, donor-specific tolerance. In this article, the minimal requirements for achieving mixed chimerism, the development of new reagents that promote its achievement, and the mechanisms by which peripheral and intrathymic tolerance are achieved via mixed chimerism are discussed. An emerging understanding of these mechanisms, along with the development of new immunosuppressive reagents, is allowing advancement toward clinical application of this approach.

  12. Quantifying uncertainty in stable isotope mixing models

    NASA Astrophysics Data System (ADS)

    Davis, Paul; Syme, James; Heikoop, Jeffrey; Fessenden-Rahn, Julianna; Perkins, George; Newman, Brent; Chrystal, Abbey E.; Hagerty, Shannon B.

    2015-05-01

    Mixing models are powerful tools for identifying biogeochemical sources and determining mixing fractions in a sample. However, identification of actual source contributors is often not simple, and source compositions typically vary or even overlap, significantly increasing model uncertainty in calculated mixing fractions. This study compares three probabilistic methods, Stable Isotope Analysis in R (SIAR), a pure Monte Carlo technique (PMC), and Stable Isotope Reference Source (SIRS) mixing model, a new technique that estimates mixing in systems with more than three sources and/or uncertain source compositions. In this paper, we use nitrate stable isotope examples (δ15N and δ18O) but all methods tested are applicable to other tracers. In Phase I of a three-phase blind test, we compared methods for a set of six-source nitrate problems. PMC was unable to find solutions for two of the target water samples. The Bayesian method, SIAR, experienced anchoring problems, and SIRS calculated mixing fractions that most closely approximated the known mixing fractions. For that reason, SIRS was the only approach used in the next phase of testing. In Phase II, the problem was broadened where any subset of the six sources could be a possible solution to the mixing problem. Results showed a high rate of Type I errors where solutions included sources that were not contributing to the sample. In Phase III some sources were eliminated based on assumed site knowledge and assumed nitrate concentrations, substantially reduced mixing fraction uncertainties and lowered the Type I error rate. These results demonstrate that valuable insights into stable isotope mixing problems result from probabilistic mixing model approaches like SIRS. The results also emphasize the importance of identifying a minimal set of potential sources and quantifying uncertainties in source isotopic composition as well as demonstrating the value of additional information in reducing the uncertainty in calculated

  13. Mixed methods research for the novice researcher.

    PubMed

    Giddings, Lynne S; Grant, Barbara M

    2006-10-01

    Mixed methods research is becoming increasingly popular in the health and social science disciplines. The aim of this article is to give an overview of the varieties of mixed methods designs. We begin by situating mixed methods research in the context of a paradigmatic framework which assists a researcher in making decisions concerning the design of their study. Although the most commonly used mixed methods designs are underpinned by positivist/postpositivist assumptions, the combination of qualitative and quantitative methods can be used within any research paradigm.

  14. Passive Microfluidic device for Sub Millisecond Mixing

    PubMed Central

    McMahon, Jay; Mohamed, Hisham; Barnard, David; Shaikh, Tanvir R.; Mannella, Carmen A.; Wagenknecht, Terence; Lu, Toh-Ming

    2009-01-01

    We report the investigation of a novel microfluidic mixing device to achieve submillisecond mixing. The micromixer combines two fluid streams of several microliters per second into a mixing compartment integrated with two T- type premixers and 4 butterfly-shaped in-channel mixing elements. We have employed three dimensional fluidic simulations to evaluate the mixing efficiency, and have constructed physical devices utilizing conventional microfabrication techniques. The simulation indicated thorough mixing at flow rate as low as 6 µL/s. The corresponding mean residence time is 0.44 ms for 90% of the particles simulated, or 0.49 ms for 95% of the particles simulated, respectively. The mixing efficiency of the physical device was also evaluated using fluorescein dye solutions and FluoSphere-red nanoparticles suspensions. The constructed micromixers achieved thorough mixing at the same flow rate of 6 µL/s, with the mixing indices of 96% ± 1%, and 98% ± 1% for the dye and the nanoparticle, respectively. The experimental results are consistent with the simulation data. The device demonstrated promising capabilities for time resolved studies for macromolecular dynamics of biological macromolecules. PMID:20161619

  15. TANK MIXING STUDY WITH FLOW RECIRCULATION

    SciTech Connect

    Lee, S.

    2014-06-25

    The primary objective of this work is to quantify the mixing time when two miscible fluids are mixed by one recirculation pump and to evaluate adequacy of 2.5 hours of pump recirculation to be considered well mixed in SRS tanks, JT-71/72. The work scope described here consists of two modeling analyses. They are the steady state flow pattern analysis during pump recirculation operation of the tank liquid and transient species transport calculations based on the initial steady state flow patterns. The modeling calculations for the mixing time are performed by using the 99% homogeneity criterion for the entire domain of the tank contents.

  16. An Introduction to LANL Mixed Potential Sensors

    SciTech Connect

    Mukundan, Rangachary; Brosha, Eric Lanich; Kreller, Cortney

    2015-01-26

    These are slides for a webinar given on the topics of an introduction to LANL mixed potential sensors. Topics include the history of LANL electrochemical sensor work, an introduction to mixed potential sensors, LANL uniqueness, and an application of LANL mixed potential sensors. The summary is as follows: Improved understanding of the mixed-potential sensor mechanism (factors controlling the sensor response identified), sensor design optimized to maximize sensor sensitivity and durability (porous electrolyte/dense electrodes), electrodes selected for various specific applications (CO, HC, H2), sensor operating parameters optimized for improved gas selectivity (NOx, NH3).

  17. Samoan Passage Abyssal Mixing Experiment

    NASA Astrophysics Data System (ADS)

    Mickett, J. B.; Voet, G.; Alford, M. H.; Girton, J. B.; Carter, G. S.

    2012-12-01

    The majority of the bottom water entering the North Pacific, about 6 Sv of mostly Antarctic origin, flows northward through the Samoan Passage (SP), where previous hydrographic studies have inferred extremely strong watermass modification as it transits the complicated, narrow passage. Global-scale numerical models at best poorly resolve this critical aspect of the global ocean circulation and the processes that affect it. We are in the midst of conducting a major next-generation experiment, coupling hydrographic/lowered ADCP and microstructure profiler measurements with simultaneous high-resolution profiling moorings and detailed numerical simulations. Our goals are to: (1) quantify the flow and its pathways through the SP, and compare them to measurements made 20 years ago as part of the World Ocean Circulation Experiment (WOCE), 2) quantify, with direct measurements, the turbulence and mixing the flow undergoes and the processes that lead to it, and 3) use the resulting knowledge to determine the best strategy for future monitoring of the SP. Here we present initial results from the first two of the experiment's three cruises, which have provided a detailed view of the flow magnitude, pathways and turbulence as it transits the passage's sills. Bathymetry, stratification, rotation, and inertia all play important roles in selecting the pathways taken by the flow, with the lighter layers siphoning off through the shallower sills to the west and the densest water following the deeper main eastern channel. Flows in this main channel are initially O(0.1 m/s), accelerating to > 0.4 m/s at the northernmost of the two major sills, leading to strong shears and warming of the bottom water from 0.66 to 0.72 C through mixing within the stratified overflow and entrainment of overlying water. Direct microstructure measurements show large vertical diffusivities of 10^{-4}-10^{-3} m^2/s throughout the passage and up to 10^{-2} m^2/s past the northern sill, where the flow

  18. Mixing it but not mixed-up: mixed methods research in medical education (a critical narrative review).

    PubMed

    Maudsley, Gillian

    2011-01-01

    Some important research questions in medical education and health services research need 'mixed methods research' (particularly synthesizing quantitative and qualitative findings). The approach is not new, but should be more explicitly reported. The broad search question here, of a disjointed literature, was thus: What is mixed methods research - how should it relate to medical education research?, focused on explicit acknowledgement of 'mixing'. Literature searching focused on Web of Knowledge supplemented by other databases across disciplines. Five main messages emerged: - Thinking quantitative and qualitative, not quantitative versus qualitative - Appreciating that mixed methods research blends different knowledge claims, enquiry strategies, and methods - Using a 'horses for courses' [whatever works] approach to the question, and clarifying the mix - Appreciating how medical education research competes with the 'evidence-based' movement, health services research, and the 'RCT' - Being more explicit about the role of mixed methods in medical education research, and the required expertise Mixed methods research is valuable, yet the literature relevant to medical education is fragmented and poorly indexed. The required time, effort, expertise, and techniques deserve better recognition. More write-ups should explicitly discuss the 'mixing' (particularly of findings), rather than report separate components.

  19. First principles nonequilibrium plasma mixing

    NASA Astrophysics Data System (ADS)

    Ticknor, C.; Herring, S. D.; Lambert, F.; Collins, L. A.; Kress, J. D.

    2014-01-01

    We have performed nonequilibrium classical and quantum-mechanical molecular dynamics simulations that follow the interpenetration of deuterium-tritium (DT) and carbon (C) components through an interface initially in hydrostatic and thermal equilibrium. We concentrate on the warm, dense matter regime with initial densities of 2.5-5.5 g/cm3 and temperatures from 10 to 100 eV. The classical treatment employs a Yukawa pair-potential with the parameters adjusted to the plasma conditions, and the quantum treatment rests on an orbital-free density functional theory at the Thomas-Fermi-Dirac level. For times greater than about a picosecond, the component concentrations evolve in accordance with Fick's law for a classically diffusing fluid with the motion, though, described by the mutual diffusion coefficient of the mixed system rather than the self-diffusion of the individual components. For shorter times, microscopic processes control the clearly non-Fickian dynamics and require a detailed representation of the electron probability density in space and time.

  20. Treatment of mixed waste coolant

    SciTech Connect

    Kidd, S.; Bowers, J.S.

    1995-02-01

    The primary processes used at Lawrence Livermore National Laboratory (LLNL) for treatment of radioactively contaminated machine coolants are industrial waste treatment and in situ carbon adsorption. These two processes simplify approaches to meeting the sanitary sewer discharge limits and subsequent Land Disposal Restriction criteria for hazardous and mixed wastes (40 CFR 268). Several relatively simple technologies are used in industrial water treatment. These technologies are considered Best Demonstrated Available Technologies, or BDAT, by the Environmental Protection Agency. The machine coolants are primarily aqueous and contain water soluble oil consisting of ethanol amine emulsifiers derived from fatty acids, both synthetic and natural. This emulsion carries away metal turnings from a part being machined on a lathe or other machining tool. When the coolant becomes spent, it contains chlorosolvents carried over from other cutting operations as well as a fair amount of tramp oil from machine bearings. This results in a multiphasic aqueous waste that requires treatment of metal and organic contaminants. During treatment, any dissolved metals are oxidized with hydrogen peroxide. Once oxidized, these metals are flocculated with ferric sulfate and precipitated with sodium hydroxide, and then the precipitate is filtered through diatomaceous earth. The emulsion is broken up by acidifying the coolant. Solvents and oils are adsorbed using powdered carbon. This carbon is easily separated from the remaining coolant by vacuum filtration.

  1. Treatment of mixed waste coolant

    SciTech Connect

    Kidd, S.; Bowers, J.S.

    1995-09-01

    The primary processes used at Lawrence Livermore National Laboratory (LLNL) for treatment of radioactively contaminated machine coolants are industrial waste treatment and in situ carbon adsorption. These two processes simplify approaches to meetings the sanitary sewer discharge limits and subsequent Land Disposal REstriction criteria for hazardous and mixed wastes (40 CFR 268). Several relatively simple technologies are used in industrial water treatment. These technologies are considered {open_quotes}Best Demonstrated Available Technologies,{close_quotes} or BDAT, by the Environmental Protection Agency. The machine coolants are primarily aqueous and contain water soluble oil consisting of ethanol amine emulsifiers derived from fatty acids, both synthetic and natural. This emulsion carries away metal turnings from a part being machined on a lathe or other machining tool. When the coolant becomes spent, it contains chlorosolvents carried over from other cutting operations as well as a fair amount of tramp oil from machine bearings. This results in a mutiphasic aqueous waste that requires treatment of metal and organic contaminants. During treatment, any dissolved metals are oxidized with hydrogen peroxide. Once oxidized, these metals are flocculated with ferric sulfate and precipitated with sodium hydroxide, and then the precipitate is filtered through diatomaceous earth. The emulsion is broken up by acidifying the coolant. Solvents and oils are adsorbed using powdered carbon. This carbon is easily separated from the remaining coolant by vacuum filtration.

  2. First principles nonequilibrium plasma mixing.

    PubMed

    Ticknor, C; Herring, S D; Lambert, F; Collins, L A; Kress, J D

    2014-01-01

    We have performed nonequilibrium classical and quantum-mechanical molecular dynamics simulations that follow the interpenetration of deuterium-tritium (DT) and carbon (C) components through an interface initially in hydrostatic and thermal equilibrium. We concentrate on the warm, dense matter regime with initial densities of 2.5-5.5 g/cm3 and temperatures from 10 to 100 eV. The classical treatment employs a Yukawa pair-potential with the parameters adjusted to the plasma conditions, and the quantum treatment rests on an orbital-free density functional theory at the Thomas-Fermi-Dirac level. For times greater than about a picosecond, the component concentrations evolve in accordance with Fick's law for a classically diffusing fluid with the motion, though, described by the mutual diffusion coefficient of the mixed system rather than the self-diffusion of the individual components. For shorter times, microscopic processes control the clearly non-Fickian dynamics and require a detailed representation of the electron probability density in space and time.

  3. Mixed Reality Meets Pharmaceutical Development.

    PubMed

    Forrest, William P; Mackey, Megan A; Shah, Vivek M; Hassell, Kerry M; Shah, Prashant; Wylie, Jennifer L; Gopinath, Janakiraman; Balderhaar, Henning; Li, Li; Wuelfing, W Peter; Helmy, Roy

    2017-09-01

    As science evolves, the need for more efficient and innovative knowledge transfer capabilities becomes evident. Advances in drug discovery and delivery sciences have directly impacted the pharmaceutical industry, though the added complexities have not shortened the development process. These added complexities also make it difficult for scientists to rapidly and effectively transfer knowledge to offset the lengthened drug development timelines. While webcams, camera phones, and iPads have been explored as potential new methods of real-time information sharing, the non-"hands-free" nature and lack of viewer and observer point-of-view render them unsuitable for the R&D laboratory or manufacturing setting. As an alternative solution, the Microsoft HoloLens mixed-reality headset was evaluated as a more efficient, hands-free method of knowledge transfer and information sharing. After completing a traditional method transfer between 3 R&D sites (Rahway, NJ; West Point, PA and Schnachen, Switzerland), a retrospective analysis of efficiency gain was performed through the comparison of a mock method transfer between NJ and PA sites using the HoloLens. The results demonstrated a minimum 10-fold gain in efficiency, weighing in from a savings in time, cost, and the ability to have real-time data analysis and discussion. In addition, other use cases were evaluated involving vendor and contract research/manufacturing organizations. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  4. Methods of testing parameterizations: Vertical ocean mixing

    NASA Technical Reports Server (NTRS)

    Tziperman, Eli

    1992-01-01

    The ocean's velocity field is characterized by an exceptional variety of scales. While the small-scale oceanic turbulence responsible for the vertical mixing in the ocean is of scales a few centimeters and smaller, the oceanic general circulation is characterized by horizontal scales of thousands of kilometers. In oceanic general circulation models that are typically run today, the vertical structure of the ocean is represented by a few tens of discrete grid points. Such models cannot explicitly model the small-scale mixing processes, and must, therefore, find ways to parameterize them in terms of the larger-scale fields. Finding a parameterization that is both reliable and plausible to use in ocean models is not a simple task. Vertical mixing in the ocean is the combined result of many complex processes, and, in fact, mixing is one of the less known and less understood aspects of the oceanic circulation. In present models of the oceanic circulation, the many complex processes responsible for vertical mixing are often parameterized in an oversimplified manner. Yet, finding an adequate parameterization of vertical ocean mixing is crucial to the successful application of ocean models to climate studies. The results of general circulation models for quantities that are of particular interest to climate studies, such as the meridional heat flux carried by the ocean, are quite sensitive to the strength of the vertical mixing. We try to examine the difficulties in choosing an appropriate vertical mixing parameterization, and the methods that are available for validating different parameterizations by comparing model results to oceanographic data. First, some of the physical processes responsible for vertically mixing the ocean are briefly mentioned, and some possible approaches to the parameterization of these processes in oceanographic general circulation models are described in the following section. We then discuss the role of the vertical mixing in the physics of the

  5. Inference of ICF implosion core mix using experimental data and theoretical mix modeling

    SciTech Connect

    Sherrill, Leslie Welser; Haynes, Donald A; Cooley, James H; Sherrill, Manolo E; Mancini, Roberto C; Tommasini, Riccardo; Golovkin, Igor E; Haan, Steven W

    2009-01-01

    The mixing between fuel and shell materials in Inertial Confinement Fusion (lCF) implosion cores is a current topic of interest. The goal of this work was to design direct-drive ICF experiments which have varying levels of mix, and subsequently to extract information on mixing directly from the experimental data using spectroscopic techniques. The experimental design was accomplished using hydrodynamic simulations in conjunction with Haan's saturation model, which was used to predict the mix levels of candidate experimental configurations. These theoretical predictions were then compared to the mixing information which was extracted from the experimental data, and it was found that Haan's mix model predicted trends in the width of the mix layer as a function of initial shell thickness. These results contribute to an assessment of the range of validity and predictive capability of the Haan saturation model, as well as increasing confidence in the methods used to extract mixing information from experimental data.

  6. Tests of Parameterized Langmuir Circulation Mixing in the Oceans Surface Mixed Layer II

    DTIC Science & Technology

    2017-08-11

    Parameterized Langmuir-Circulation Mixing in the Ocean’s Surface Mixed Layer II Paul J. Martin Ocean Dynamics and Prediction Branch Oceanography...Division ivan B. Savelyev Coastal and Ocean Remote Sensing Branch Remote Sensing Division August 11, 2017 i REPORT DOCUMENTATION PAGE Form ApprovedOMB No...the ocean found that LC can significantly increase the rate of mixing within the SML and sometimes increase the mixed layer depth (MLD). This report

  7. Neutrino mixing and oscillations in astrophysical environments

    SciTech Connect

    Balantekin, A. B.

    2014-05-02

    A brief review of the current status of neutrino mixing and oscillations in astrophysical environments, with particular emphasis on the Sun and core-collapse supernovae, is given. Implications of the existence of sterile states which mix with the active neutrinos are discussed.

  8. Mixed Methods Approaches in Family Science Research

    ERIC Educational Resources Information Center

    Plano Clark, Vicki L.; Huddleston-Casas, Catherine A.; Churchill, Susan L.; Green, Denise O'Neil; Garrett, Amanda L.

    2008-01-01

    The complex phenomena of interest to family scientists require the use of quantitative and qualitative approaches. Researchers across the social sciences are now turning to mixed methods designs that combine these two approaches. Mixed methods research has great promise for addressing family science topics, but only if researchers understand the…

  9. 7 CFR 29.3532 - Mixed (M).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Mixed (M). 29.3532 Section 29.3532 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3532 Mixed (M). Variegated or distinctly different colors of the type mingled...

  10. Tower Water-Vapor Mixing Ratio

    SciTech Connect

    Guastad, Krista; Riihimaki, Laura; none,

    2013-04-01

    The purpose of the Tower Water-Vapor Mixing Ratio (TWRMR) value-added product (VAP) is to calculate water-vapor mixing ratio at the 25-meter and 60-meter levels of the meteorological tower at the Southern Great Plains (SGP) Central Facility.

  11. Mixed Methods Research Designs in Counseling Psychology

    ERIC Educational Resources Information Center

    Hanson, William E.; Creswell, John W.; Clark, Vicki L. Plano; Petska, Kelly S.; Creswell, David J.

    2005-01-01

    With the increased popularity of qualitative research, researchers in counseling psychology are expanding their methodologies to include mixed methods designs. These designs involve the collection, analysis, and integration of quantitative and qualitative data in a single or multiphase study. This article presents an overview of mixed methods…

  12. Treatment of mixed features in bipolar disorder.

    PubMed

    Rosenblat, Joshua D; McIntyre, Roger S

    2016-09-13

    Mood episodes with Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)-defined mixed features are highly prevalent in bipolar disorder (BD), affecting ~40% of patients during the course of illness. Mixed states are associated with poorer clinical outcomes, greater treatment resistance, higher rates of comorbidity, more frequent mood episodes, and increased rates of suicide. The objectives of the current review are to identify, summarize, and synthesize studies assessing the efficacy of treatments specifically for BD I and II mood episodes (ie, including manic, hypomanic, and major depressive episodes) with DSM-5-defined mixed features. Two randomized controlled trials (RCTs) and 6 post-hoc analyses were identified, all of which assessed the efficacy of second-generation antipsychotics (SGAs) for the acute treatment of BD mood episodes with mixed features. Results from these studies provide preliminary support for SGAs as efficacious treatments for both mania with mixed features and bipolar depression with mixed features. However, there are inadequate data to definitively support or refute the clinical use of specific agents. Conventional mood stabilizing agents (eg, lithium and divalproex) have yet to have been adequately studied in DSM-5-defined mixed features. Further study is required to assess the efficacy, safety, and tolerability of treatments specifically for BD mood episodes with mixed features.

  13. 7 CFR 29.3532 - Mixed (M).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Mixed (M). 29.3532 Section 29.3532 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... Type 95) § 29.3532 Mixed (M). Variegated or distinctly different colors of the type mingled...

  14. Is There a School Mix Effect?

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2006-01-01

    This paper uses the notion of "pathological" social science, wherein large claims to knowledge are made on the basis of very small differences in the data, to consider the notion of the school mix effect. It describes a variety of plausible alternative explanations for the same sets of findings, including the school mix effect, but also errors in…

  15. Film processing investigation. [improved chemical mixing system

    NASA Technical Reports Server (NTRS)

    Kelly, J. L.

    1972-01-01

    The present operational chemical mixing system for the Photographic Technology Division is evaluated, and the limitations are defined in terms of meeting the present and programmed chemical supply and delivery requirements. A major redesign of the entire chemical mixing, storage, analysis, and supply system is recommended. Other requirements for immediate and future implementations are presented.

  16. Flowmeter determines mix ratio for viscous adhesives

    NASA Technical Reports Server (NTRS)

    Lemons, C. R.

    1967-01-01

    Flowmeter determines mix ratio for continuous flow mixing machine used to produce an adhesive from a high viscosity resin and aliphatic amine hardener pumped through separate lines to a rotary blender. The flowmeter uses strain gages in the two flow paths and monitors their outputs with appropriate instrumentation.

  17. Mixed Methods Approaches in Family Science Research

    ERIC Educational Resources Information Center

    Plano Clark, Vicki L.; Huddleston-Casas, Catherine A.; Churchill, Susan L.; Green, Denise O'Neil; Garrett, Amanda L.

    2008-01-01

    The complex phenomena of interest to family scientists require the use of quantitative and qualitative approaches. Researchers across the social sciences are now turning to mixed methods designs that combine these two approaches. Mixed methods research has great promise for addressing family science topics, but only if researchers understand the…

  18. "Reading" Mixed Methods Research: Contexts for Criticism

    ERIC Educational Resources Information Center

    Freshwater, Dawn

    2007-01-01

    Health and social care researchers, in their haste to "belong" to academia, have adopted the system of mixed methodology research, overestimating its ability to reveal the truth and occasionally imprisoning their thought in one system. In this article, some of the assumptions underpinning mixed methodology research and its discourse are subjected…

  19. Chemical Reactions in Turbulent Mixing Flows

    DTIC Science & Technology

    1989-10-15

    GROUP Turbulence, shear layers, jets, mixing, combustion , 21 ni numerical simulation, light detection diagnostics 21 02 9. ABSTRACT (Conmmna on...mixing chemical reactions and combustion processes in turbulent, subsonic and supersonic flows. This program is comprised of several efforts. In...permit the full chemical kinetics of the combustion process to be incorporated. Our recent analytical efforts have concentrated on a 20

  20. Thin films of mixed metal compounds

    DOEpatents

    Mickelsen, Reid A.; Chen, Wen S.

    1985-01-01

    A compositionally uniform thin film of a mixed metal compound is formed by simultaneously evaporating a first metal compound and a second metal compound from independent sources. The mean free path between the vapor particles is reduced by a gas and the mixed vapors are deposited uniformly. The invention finds particular utility in forming thin film heterojunction solar cells.

  1. Discontinuous Mixed Covolume Methods for Parabolic Problems

    PubMed Central

    Zhu, Ailing

    2014-01-01

    We present the semidiscrete and the backward Euler fully discrete discontinuous mixed covolume schemes for parabolic problems on triangular meshes. We give the error analysis of the discontinuous mixed covolume schemes and obtain optimal order error estimates in discontinuous H(div) and first-order error estimate in L2. PMID:24983008

  2. Critical Appraisal of Mixed Methods Studies

    ERIC Educational Resources Information Center

    Heyvaert, Mieke; Hannes, Karin; Maes, Bea; Onghena, Patrick

    2013-01-01

    In several subdomains of the social, behavioral, health, and human sciences, research questions are increasingly answered through mixed methods studies, combining qualitative and quantitative evidence and research elements. Accordingly, the importance of including those primary mixed methods research articles in systematic reviews grows. It is…

  3. Mixed Methods, Triangulation, and Causal Explanation

    ERIC Educational Resources Information Center

    Howe, Kenneth R.

    2012-01-01

    This article distinguishes a disjunctive conception of mixed methods/triangulation, which brings different methods to bear on different questions, from a conjunctive conception, which brings different methods to bear on the same question. It then examines a more inclusive, holistic conception of mixed methods/triangulation that accommodates…

  4. 7 CFR 51.576 - Mixed blanch.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... Standards for Celery Definitions § 51.576 Mixed blanch. Mixed blanch consists of green and fairly...

  5. 7 CFR 51.576 - Mixed blanch.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... Standards for Celery Definitions § 51.576 Mixed blanch. Mixed blanch consists of green and fairly...

  6. Mixed Methods Research Designs in Counseling Psychology

    ERIC Educational Resources Information Center

    Hanson, William E.; Creswell, John W.; Clark, Vicki L. Plano; Petska, Kelly S.; Creswell, David J.

    2005-01-01

    With the increased popularity of qualitative research, researchers in counseling psychology are expanding their methodologies to include mixed methods designs. These designs involve the collection, analysis, and integration of quantitative and qualitative data in a single or multiphase study. This article presents an overview of mixed methods…

  7. Efficiency of Metal Mixing in Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Hirai, Yutaka; Saitoh, Takayuki R.

    2017-04-01

    Metal mixing plays a critical role in the enrichment of metals in galaxies. The abundance of elements such as Mg, Fe, and Ba in metal-poor stars helps us understand the metal mixing in galaxies. However, the efficiency of metal mixing in galaxies is not yet understood. Here we report a series of N-body/smoothed particle hydrodynamics simulations of dwarf galaxies with different efficiencies of metal mixing using a turbulence-induced mixing model. We show that metal mixing apparently occurs in dwarf galaxies from Mg and Ba abundances. We find that a scaling factor for metal diffusion larger than 0.01 is necessary to reproduce the measured abundances of Ba in dwarf galaxies. This value is consistent with the value expected from turbulence theory and experiments. We also find that the timescale of metal mixing is less than 40 Myr. This timescale is shorter than the typical dynamical times of dwarf galaxies. We demonstrate that the determination of a degree of scatters of Ba abundance by the observation will help us to better constrain the efficiency of metal mixing.

  8. Mixed refrigerant Joule-Thomson sorption cryocoolers

    NASA Astrophysics Data System (ADS)

    Tzabar, Nir; Grossman, Gershon

    2014-01-01

    Joule-Thomson (JT) sorption cryocooling is the most mature technology for cooling from a normal Room-Temperature (RT) down to temperatures below 100 K in the absence of moving parts. Therefore, high reliability and no vibrations are attainable, in comparison with other cryocoolers. Cooling to 80 - 100 K with JT cryocoolers is often implemented with pure nitrogen. Alternatively, mixed refrigerants have been suggested for reducing the operating pressures to enable closed cycle cryocooling. There is a variety of publications describing nitrogen sorption cryocoolers with different configurations of sorption compressors. In the present research we suggest a novel sorption JT cryocooler that operates with a mixed refrigerant. Merging of sorption cryocooling and a mixed refrigerant enables the use of a simple, single stage compressor for cooling to 80 - 100 K, lower operating temperatures of the sorption cycle, and thus - reduced power consumption. In previous studies we have analyzed sorption compressors for mixed gases and mixed refrigerants for JT cryocoolers, separately. In this paper the option of mixed refrigerant sorption JT cryocoolers is explored. The considerations for developing mixed refrigerants to be driven by sorption compressors and to be utilized with JT cryocoolers are provided. It appears that, unlike with pure nitrogen, mixed refrigerants can be suitable for JT cryocooling with a single stage sorption compressor.

  9. Estimating growth and yield of mixed stands

    Treesearch

    Stephen R. Shifley; Burnell C. Fischer

    1989-01-01

    A mixed stand is defined as one in which no single species comprises more than 80 percent of the stocking. The growth estimation methods described below can be used not only in mixed stands but in almost any stand, regardless of species composition, age structure, or size structure. The methods described are necessary to accommodate the complex species mixtures and...

  10. Critical Appraisal of Mixed Methods Studies

    ERIC Educational Resources Information Center

    Heyvaert, Mieke; Hannes, Karin; Maes, Bea; Onghena, Patrick

    2013-01-01

    In several subdomains of the social, behavioral, health, and human sciences, research questions are increasingly answered through mixed methods studies, combining qualitative and quantitative evidence and research elements. Accordingly, the importance of including those primary mixed methods research articles in systematic reviews grows. It is…

  11. Mixed methods research in music therapy research.

    PubMed

    Bradt, Joke; Burns, Debra S; Creswell, John W

    2013-01-01

    Music therapists have an ethical and professional responsibility to provide the highest quality care possible to their patients. Much of the time, high quality care is guided by evidence-based practice standards that integrate the most current, available research in making decisions. Accordingly, music therapists need research that integrates multiple ways of knowing and forms of evidence. Mixed methods research holds great promise for facilitating such integration. At this time, there have not been any methodological articles published on mixed methods research in music therapy. The purpose of this article is to introduce mixed methods research as an approach to address research questions relevant to music therapy practice. This article describes the core characteristics of mixed methods research, considers paradigmatic issues related to this research approach, articulates major challenges in conducting mixed methods research, illustrates four basic designs, and provides criteria for evaluating the quality of mixed methods articles using examples of mixed methods research from the music therapy literature. Mixed methods research offers unique opportunities for strengthening the evidence base in music therapy. Recommendations are provided to ensure rigorous implementation of this research approach.

  12. "Reading" Mixed Methods Research: Contexts for Criticism

    ERIC Educational Resources Information Center

    Freshwater, Dawn

    2007-01-01

    Health and social care researchers, in their haste to "belong" to academia, have adopted the system of mixed methodology research, overestimating its ability to reveal the truth and occasionally imprisoning their thought in one system. In this article, some of the assumptions underpinning mixed methodology research and its discourse are subjected…

  13. Mixing efficiency of turbulent stratified flows

    NASA Astrophysics Data System (ADS)

    White, B. L.; Scotti, A. D.

    2012-12-01

    Small-scale mixing in the stratified interior of the ocean is a fundamental, but poorly characterized, controlling factor of the global Meridional Overturning Circulation (MOC). The mixing efficiency in the ocean has typically been assumed to be 20%, which is used as a basis to estimate the required turbulent dissipation to support the ocean diapycnal buoyancy flux. In this talk, we use DNS datasets to calculate the mixing efficiency in different classes of stratified turbulent flows. In particular, we compare flows forced thermodynamically by production of Available Potential Energy (APE) at a boundary, such as horizontal convection (a simple model for an ocean forced by differential surface heating) and flows that are forced mechanically by surface stresses. The mixing efficiency is calculated based on the irreversible diapycnal flux of buoyancy (Winters and D'Asaro, 1996; Scotti et al., 2006) instead of the more customary turbulent buoyancy flux, thereby isolating mixing from reversible processes (e.g., internal waves). For mechanically-driven flows, profiles of mixing efficiency vs. buoyancy Reynolds number are in agreement with accepted values for stratified turbulent shear flows. However, for flows in which mixing is driven in part or fully by thermodynamic forcing and an excess of APE, DNS results show much higher values of the mixing efficiency, approaching unity for horizontal convection. Implications of these results for the energy budget of the MOC are discussed. Note: The DNS data sets of turbulent stratified channel flow are provided courtesy of M. Garcia-Villalba and J. C. del Alamo.

  14. Toponium-Z/sup 0/ mixing

    SciTech Connect

    Franzini, P.J.

    1986-11-01

    The subject of Z/sup 0/-toponium interference is briefly reviewed. The qualitative features of the Z/sup 0/ mixing with one t anti t state are discussed. Effects of mixing with the full t anti t spectrum, of the smearing due to beam spread, and of different potentials, are then shown.

  15. Transformative Paradigm: Mixed Methods and Social Justice

    ERIC Educational Resources Information Center

    Mertens, Donna M.

    2007-01-01

    The intersection of mixed methods and social justice has implications for the role of the researcher and choices of specific paradigmatic perspectives. The transformative paradigm with its associated philosophical assumptions provides a framework for addressing inequality and injustice in society using culturally competent, mixed methods…

  16. Mixed Methods, Triangulation, and Causal Explanation

    ERIC Educational Resources Information Center

    Howe, Kenneth R.

    2012-01-01

    This article distinguishes a disjunctive conception of mixed methods/triangulation, which brings different methods to bear on different questions, from a conjunctive conception, which brings different methods to bear on the same question. It then examines a more inclusive, holistic conception of mixed methods/triangulation that accommodates…

  17. Mixing Methods in Assessing Coaches' Decision Making

    ERIC Educational Resources Information Center

    Vergeer, Ineke; Lyle, John

    2007-01-01

    Mixing methods has recently achieved respectability as an appropriate approach to research design, offering a variety of advantages (Tashakkori & Teddlie, 2003). The purpose of this paper is to outline and evaluate a mixed methods approach within the domain of coaches' decision making. Illustrated with data from a policy-capturing study on…

  18. Quark lepton universality and large leptonic mixing

    NASA Astrophysics Data System (ADS)

    Joshipura, Anjan S.; Smirnov, A. Yu.

    2006-08-01

    A unified description of fermionic mixing is proposed which assumes that in certain basis (i) a single complex unitary matrix V diagonalizes mass matrices of all fermions to the leading order, (ii) the SU(5) relation M=MlT exists between the mass matrices of the down quarks and the charged leptons, and (iii) Md†=M. These assumptions automatically lead to different mixing patterns for quarks and leptons: Quarks remain unmixed to leading order (i.e. V=1) while leptons have non-trivial mixing given by a symmetric unitary matrix VPMNS0=VV. V depends on two physical mixing angles and for values of these angles ˜20°-25° it reproduces the observed mixing patterns rather well. We identify conditions under which the universal mixing V follows from the universal mass matrices of fermions. Relatively small perturbations to the leading order structure lead to the CKM mixing and corrections to VPMNS0. We find that if the correction matrix equals the CKM matrix, the resulting lepton mixing agrees well with data and predicts ()e3>0.08.

  19. The Generative Potential of Mixed Methods Inquiry

    ERIC Educational Resources Information Center

    Greene, Jennifer C.

    2005-01-01

    A mixed method approach to educational and social inquiry is presented as an important counterpoint to the contemporary debate about what constitutes valid, rigorous, and "scientific" research. By welcoming all legitimate methodological traditions, mixed method inquiry meaningfully engages with difference and thus offers some generative potential…

  20. Physical properties of mixed dairy food proteins

    USDA-ARS?s Scientific Manuscript database

    Mixed food protein gels are complex systems, which changes functional behaviors such as gelling properties and viscosity depending on the miscibility of the proteins. We have noted that differences in co-solubility of mixed proteins created unique network structures and gel properties. The effects o...

  1. Milestone M4900: Simulant Mixing Analytical Results

    SciTech Connect

    Kaplan, D.I.

    2001-07-26

    This report addresses Milestone M4900, ''Simulant Mixing Sample Analysis Results,'' and contains the data generated during the ''Mixing of Process Heels, Process Solutions, and Recycle Streams: Small-Scale Simulant'' task. The Task Technical and Quality Assurance Plan for this task is BNF-003-98-0079A. A report with a narrative description and discussion of the data will be issued separately.

  2. Physics of collisionless phase mixing

    SciTech Connect

    Tsiklauri, D.; Haruki, T.

    2008-11-15

    Previous studies of phase mixing of ion cyclotron (IC), Alfvenic, waves in the collisionless regime have established the generation of parallel electric field and hence acceleration of electrons in the regions of transverse density inhomogeneity. However, outstanding issues were left open. Here we use the 2.5 D, relativistic, fully electromagnetic particle-in-cell code and an analytic magnetohydrodynamic (MHD) formulation, to establish the following points: (i) Using the generalized Ohm's law we find that the parallel electric field is supported mostly by the electron pressure tensor, with a smaller contribution from the electron inertia term. (ii) The generated parallel electric field and the fraction of accelerated electrons are independent of the IC wave frequency remaining at a level of six orders of magnitude larger than the Dreicer value and approximately 20%, respectively. The generated parallel electric field and the fraction of accelerated electrons increase with the increase of IC wave amplitude. The generated parallel electric field seems to be independent of plasma beta, while the fraction of accelerated electrons strongly increases with the decrease of plasma beta (for plasma beta of 0.0001 the fraction of accelerated electrons can be as large as 47%). (iii) In the collisionless regime IC wave dissipation length (that is defined as the distance over which the wave damps) variation with the driving frequency shows a deviation from the analytical MHD result, which we attribute to a possible frequency dependence of the effective resistivity. (iv) Effective anomalous resistivity, inferred from our numerical simulations, is at least four orders of magnitude larger than the classical Spitzer value.

  3. The mixed waste management facility

    SciTech Connect

    Streit, R.D.

    1995-10-01

    During FY96, the Mixed Waste Management Facility (MWMF) Project has the following major objectives: (1) Complete Project Preliminary Design Review (PDR). (2) Complete final design (Title II) of MWMF major systems. (3) Coordinate all final interfaces with the Decontamination and Waste Treatment Facility (DWTF) for facility utilities and facility integration. (4) Begin long-lead procurements. (5) Issue Project Baseline Revision 2-Preliminary Design (PB2), modifying previous baselines per DOE-requested budget profiles and cost reduction. Delete Mediated Electrochemical Oxidation (MEO) as a treatment process for initial demonstration. (6) Complete submittal of, and ongoing support for, applications for air permit. (7) Begin detailed planning for start-up, activation, and operational interfaces with the Laboratory`s Hazardous Waste Management Division (HWM). In achieving these objectives during FY96, the Project will incorporate and implement recent DOE directives to maximize the cost savings associated with the DWTF/MWMF integration (initiated in PB1.2); to reduce FY96 new Budget Authority to {approximately}$10M (reduced from FY97 Validation of $15.3M); and to keep Project fiscal year funding requirements largely uniform at {approximately}$10M/yr. A revised Project Baseline (i.e., PB2), to be issued during the second quarter of FY96, will address the implementation and impact of this guidance from an overall Project viewpoint. For FY96, the impact of this guidance is that completion of final design has been delayed relative to previous baselines (resulting from the delay in the completion of preliminary design); ramp-up in staffing has been essentially eliminated; and procurements have been balanced through the Project to help balance budget needs to funding availability.

  4. Patterns of Age Mixing and Gender Mixing among Children and Adolescents at an Ungraded School.

    ERIC Educational Resources Information Center

    Gray, Peter; Feldman, Jay

    1997-01-01

    Examined age and gender mixing among students, ages 4-19, at an ungraded, self-directed, democratically structured school. Found that age mixing was more frequent for 12- to 15-year-olds than for younger or older students, and that gender mixing was less frequent for 8- to 11-year-olds than for any other age group. (MDM)

  5. Mixed Methods Research in School Psychology: A Mixed Methods Investigation of Trends in the Literature

    ERIC Educational Resources Information Center

    Powell, Heather; Mihalas, Stephanie; Onwuegbuzie, Anthony J.; Suldo, Shannon; Daley, Christine E.

    2008-01-01

    This article illustrates the utility of mixed methods research (i.e., combining quantitative and qualitative techniques) to the field of school psychology. First, the use of mixed methods approaches in school psychology practice is discussed. Second, the mixed methods research process is described in terms of school psychology research. Third, the…

  6. The use of "mixing" procedure of mixed methods in health services research.

    PubMed

    Zhang, Wanqing; Creswell, John

    2013-08-01

    Mixed methods research has emerged alongside qualitative and quantitative approaches as an important tool for health services researchers. Despite growing interest, among health services researchers, in using mixed methods designs, little has been done to identify the procedural aspects of doing so. To describe how mixed methods researchers mix the qualitative and quantitative aspects of their studies in health services research. We searched the PubMed for articles, using mixed methods in health services research, published between January 1, 2006 and December 30, 2010. We identified and reviewed 30 published health services research articles on studies in which mixed methods had been used. We selected 3 articles as illustrations to help health services researcher conceptualize the type of mixing procedures that they were using. Three main "mixing" procedures have been applied within these studies: (1) the researchers analyzed the 2 types of data at the same time but separately and integrated the results during interpretation; (2) the researchers connected the qualitative and quantitative portions in phases in such a way that 1 approach was built upon the findings of the other approach; and (3) the researchers mixed the 2 data types by embedding the analysis of 1 data type within the other. "Mixing" in mixed methods is more than just the combination of 2 independent components of the quantitative and qualitative data. The use of "mixing" procedure in health services research involves the integration, connection, and embedding of these 2 data components.

  7. Mixed Methods Research in School Psychology: A Mixed Methods Investigation of Trends in the Literature

    ERIC Educational Resources Information Center

    Powell, Heather; Mihalas, Stephanie; Onwuegbuzie, Anthony J.; Suldo, Shannon; Daley, Christine E.

    2008-01-01

    This article illustrates the utility of mixed methods research (i.e., combining quantitative and qualitative techniques) to the field of school psychology. First, the use of mixed methods approaches in school psychology practice is discussed. Second, the mixed methods research process is described in terms of school psychology research. Third, the…

  8. Imaging of microscale mixing in biological suspensions

    NASA Astrophysics Data System (ADS)

    Son, Kwangmin; Stocker, Roman

    2015-11-01

    In many biological processes, reaction rates are set by the degree of mixing. A prime example is virus-host infection. Protocols and approaches in the study of these processes often ignore fundamental principles on stirring and mixing, which show how difficult or lengthy it can be to truly mix biological scalars, such a microorganisms. Such results date back to the classical works of Purcell (JFM 1978) and Batchelor (JFM 1979), yet were mostly limited to theoretical predictions, which have awaited accurate experimental testing and have not made their way into biological applications to date. Here we investigate the stirring and mixing of suspensions of motile and nonmotile microorganisms by real-time imaging with optical microscopy, testing theoretical predictions and demonstrating that fundamental protocols in biology often vastly underestimate the heterogeneity in biological suspensions arising from incomplete mixing.

  9. Thin films of mixed metal compounds

    DOEpatents

    Mickelsen, R.A.; Chen, W.S.

    1985-06-11

    Disclosed is a thin film heterojunction solar cell, said heterojunction comprising a p-type I-III-IV[sub 2] chalcopyrite substrate and an overlying layer of an n-type ternary mixed metal compound wherein said ternary mixed metal compound is applied to said substrate by introducing the vapor of a first metal compound to a vessel containing said substrate from a first vapor source while simultaneously introducing a vapor of a second metal compound from a second vapor source of said vessel, said first and second metals comprising the metal components of said mixed metal compound; independently controlling the vaporization rate of said first and second vapor sources; reducing the mean free path between vapor particles in said vessel, said gas being present in an amount sufficient to induce homogeneity of said vapor mixture; and depositing said mixed metal compound on said substrate in the form of a uniform composition polycrystalline mixed metal compound. 5 figs.

  10. Continuous Microfluidic Mixing Using Pulsatile Micropumps

    NASA Astrophysics Data System (ADS)

    Deshmukh, Ajay; Liepmann, Dorian

    2000-11-01

    For many microfluidic and micro-TAS applications, the mixing of two fluids is required. At small length scales, however, traditional means of mixing, such as turbulence generation, are impossible yet diffusion is often too slow. For laminar mixing, 3 degrees of freedom are required. Since MEMS are normally 2-D, time-dependence is added for the third degree of freedom. This process involves the use of two positive displacement pumps to alternatively deliver two different fluids into a common channel and utilizing Taylor dispersion to mix them. This mixing process was modelled numerically and confirmed via experimental observation of fluorescent dye in a fabricated MEMS mixer. The pumps used in the device are a new design consisting of a bubble-piston and two check valves.

  11. Dilution Jet Mixing Program, phase 1

    NASA Technical Reports Server (NTRS)

    Srinivasan, R.; Berenfeld, A.; Mongia, H. C.

    1982-01-01

    The effect of jet to mainstream density ratio, flow area convergence as encounted in transition sections, and nonuniform mainstream profile upstream of dilution orifices on the mixing of a row of jets with a confined cross flow was quantified. It is found that: (1) jet spreading rate in transverse direction is increased with increasing J, H/D and with decreasing S/D; (2) the density ratio has only a second order effect on the jet mixing characteristics for a constant momentum ratio; (3) the temperature distributions in the jet mixing region are strongly influenced by the undisturbed mainstream profile; (4) flow area convergence enhances mixing in radial and transverse directions. An asymmetric convergent duct with flat wall injection has the same jet mixing characteristics as a symmetric convergent duct. An asymmetric convergent duct with slant wall injection has a faster jet spreading rate in the transverse direction.

  12. CFD simulation of mixing in anaerobic digesters.

    PubMed

    Terashima, Mitsuharu; Goel, Rajeev; Komatsu, Kazuya; Yasui, Hidenari; Takahashi, Hiroshi; Li, Y Y; Noike, Tatsuya

    2009-04-01

    A three-dimensional CFD model incorporating the rheological properties of sludge was developed and applied to quantify mixing in a full-scale anaerobic digester. The results of the model were found to be in good agreement with experimental tracer response curve. In order to predict the dynamics of mixing, a new parameter, UI (uniformity index) was defined. The visual patterns of tracer mixing in simulation were well reflected in the dynamic variation in the value of UI. The developed model and methods were applied to determine the required time for complete mixing in a full-scale digester at different solid concentrations. This information on mixing time is considered to be useful in optimizing the feeding cycles for better digester performance.

  13. Mixed waste characterization, treatment & disposal focus area

    SciTech Connect

    1996-08-01

    The mission of the Mixed Waste Characterization, Treatment, and Disposal Focus Area (referred to as the Mixed Waste Focus Area or MWFA) is to provide treatment systems capable of treating DOE`s mixed waste in partnership with users, and with continual participation of stakeholders, tribal governments, and regulators. The MWFA deals with the problem of eliminating mixed waste from current and future storage in the DOE complex. Mixed waste is waste that contains both hazardous chemical components, subject to the requirements of the Resource Conservation and Recovery Act (RCRA), and radioactive components, subject to the requirements of the Atomic Energy Act. The radioactive components include transuranic (TRU) and low-level waste (LLW). TRU waste primarily comes from the reprocessing of spent fuel and the use of plutonium in the fabrication of nuclear weapons. LLW includes radioactive waste other than uranium mill tailings, TRU, and high-level waste, including spent fuel.

  14. Investigating Turbulent Mix in HEDLP Experiments

    NASA Astrophysics Data System (ADS)

    Flippo, K. A.; Doss, F. W.; Devolder, B.; Fincke, J. R.; Loomis, E. N.; Kline, J. L.; Welser-Sherrill, L.

    2016-03-01

    Mix is an important issue in High Energy Density Laboratory Plasmas (HEDLP), specifically Inertial Confinement Fusion (ICF) implosions. In ICF, shock waves traverse fuel capsule defects and material interfaces, and due to hydrodynamic instabilities transitioning into turbulence, these shocks can initiate mix between shell and fuel, degrading yield. To this end, a series of laser-driven mix experiments has been designed for the OMEGA and NIF laser facilities to investigate the turbulent mixing of materials proceeded by reshock and shear, which initiates Richtmyer-Meshkov and\\or Kelvin-Helmholtz instabilities on a tracer layer. The experiments are designed to understand if the Besnard-Harlow-Rauenzahn (BHR) mix model that has been implemented in LANL's RAGE hydrodynamics code has coefficients that are properly determined for an HEDLP environment.

  15. PREFACE Turbulent Mixing and Beyond

    NASA Astrophysics Data System (ADS)

    Abarzhi, Snezhana I.; Gauthier, Serge; Niemela, Joseph J.

    2010-12-01

    The goals of the International Conference 'Turbulent Mixing and Beyond', TMB-2009, are to expose the generic problem of non-equilibrium turbulent processes to a broad scientific community, to promote the development of new ideas in tackling the fundamental aspects of the problem, to assist in the application of novel approaches in a broad range of phenomena, where the turbulent processes occur, and to have a potential impact on technology. The Conference provides the opportunity to bring together researchers from different areas, which include but are not limited to fluid dynamics, plasmas, high energy density physics, astrophysics, material science, combustion, atmospheric and Earth sciences, nonlinear and statistical physics, applied mathematics, probability and statistics, data processing and computations, optics and telecommunications, and to have their attention focused on the long-standing formidable task of non-equilibrium processes. Non-equilibrium turbulent processes play a key role in a broad variety of phenomena spanning astrophysical to atomistic scales and high or low energy density regimes. Inertial confinement and magnetic fusion, light-matter interaction and non-equilibrium heat transfer, strong shocks and explosions, material transformation under high strain rate, supernovae and accretion disks, stellar non-Boussinesq and magneto-convection, planetary interiors and mantle-lithosphere tectonics, premixed and non-premixed combustion, non-canonical wall-bounded flows, hypersonic and supersonic boundary layers, dynamics of atmosphere and oceanography, are just a few examples. A grip on non-equilibrium turbulent processes is crucial for cutting-edge technology such as laser micro-machining, nano-electronics, free-space optical telecommunications, and for industrial applications in the areas of aeronautics and aerodynamics. Non-equilibrium turbulent processes are anisotropic, non-local, multi-scale and multi-phase, and often are driven by shocks or

  16. Nationwide review of mixed and non-mixed components from different manufacturers in total hip arthroplasty

    PubMed Central

    Peters, Rinne M; van Steenbergen, Liza N; Bulstra, Sjoerd K; Zeegers, Adelgunde V C M; Stewart, Roy E; Poolman, Rudolf W; Hosman, Anton H

    2016-01-01

    Background and purpose Combining components from different manufacturers in total hip arthroplasty (THA) is common practice worldwide. We determined the proportion of THAs used in the Netherlands that consist of components from different manufacturers, and compared the revision rates of these mixed THAs with those of non-mixed THAs. Patients and methods Data on primary and revision hip arthroplasty are recorded in the LROI, the nationwide population-based arthroplasty register in the Netherlands. We selected all 163,360 primary THAs that were performed in the period 2007–2014. Based on the manufacturers of the components, 4 groups were discerned: non-mixed THAs with components from the same manufacturer (n = 142,964); mixed stem-head THAs with different manufacturers for the femoral stem and head (n = 3,663); mixed head-cup THAs with different head and cup manufacturers (n = 12,960), and mixed stem-head-cup THAs with different femoral stem, head, and cup manufacturers (n = 1,773). Mixed prostheses were defined as THAs (stem, head, and cup) composed of components made by different manufacturers. Results 11% of THAs had mixed components (n = 18,396). The 6-year revision rates were similar for mixed and non-mixed THAs: 3.4% (95% CI: 3.1w–3.7) for mixed THAs and 3.5% (95% CI: 3.4–3.7) for non-mixed THAs. Revision of primary THAs due to loosening of the acetabulum was more common in mixed THAs (16% vs. 12%). Interpretation Over an 8-year period in the Netherlands, 11% of THAs had mixed components—with similar medium-term revision rates to those of non-mixed THAs. PMID:27348544

  17. Mixed Waste Integrated Program: A technology assessment for mercury-containing mixed wastes

    SciTech Connect

    Perona, J.J.; Brown, C.H.

    1993-03-01

    The treatment of mixed wastes must meet US Environmental Protection Agency (EPA) standards for chemically hazardous species and also must provide adequate control of the radioactive species. The US Department of Energy (DOE) Office of Technology Development established the Mixed Waste Integrated Program (MWIP) to develop mixed-waste treatment technology in support of the Mixed Low-Level Waste Program. Many DOE mixed-waste streams contain mercury. This report is an assessment of current state-of-the-art technologies for mercury separations from solids, liquids, and gases. A total of 19 technologies were assessed. This project is funded through the Chemical-Physical Technology Support Group of the MWIP.

  18. Evaluation of a metering, mixing, and dispensing system for mixing polysulfide adhesive

    NASA Technical Reports Server (NTRS)

    Evans, Kurt B.

    1989-01-01

    Tests were performed to evaluate whether a metered mixing system can mix PR-1221 polysulfide adhesive as well as or better than batch-mixed adhesive; also, to evaluate the quality of meter-mixed PR-1860 and PS-875 polysulfide adhesives. These adhesives are candidate replacements for PR-1221 which will not be manufactured in the future. The following material properties were evaluated: peel strength, specific gravity and adhesive components of mixed adhesives, Shore A hardness, tensile adhesion strength, and flow rate. Finally, a visual test called the butterfly test was performed to observe for bubbles and unmixed adhesive. The results of these tests are reported and discussed.

  19. Effects of mixing protocol and mixing time on viscoelasticity of compatibilized PP/PS blends

    NASA Astrophysics Data System (ADS)

    Salehiyan, Reza; Choi, Woo Jin; Lee, Jun Hyup; Hyun, Kyu

    2014-08-01

    Linear and non-linear viscoelastic properties of Polypropylene (PP)/Polystyrene (PS) blends with organoclay (C20A) as a compatibilizer were investigated using dynamic oscillatory measurement, i.e., small amplitude oscillatory shear (SAOS) and large amplitude oscillatory shear (LAOS) tests. Four different mixing protocols were applied to probe the effect of mixing sequence on rheological properties. Moreover, each protocol was conducted at three mixing times, i.e., 1, 3, and 8 min, to investigate the effect of mixing time on final rheological properties. Final results revealed that mixing time had no significant effect on either the viscoelastic response of the simultaneously mixed blends or the PP+C20A/PS (PP and C20A mixed for 30 seconds and then PS added) blend. On the other hand, rheological properties of the PS+C20A/PP (PS and C20A mixed for 30 seconds and then PP added) blend significantly increased upon 1 min of total mixing time, whereas 3 and 8 min of mixing demonstrated almost the same results as their other blended counterparts. TEM pictures revealed migration of C20A particles from PS phase towards the interface with increasing mixing time.

  20. Mixing in microfluidic devices and enhancement methods

    PubMed Central

    Ward, Kevin; Fan, Z Hugh

    2015-01-01

    Mixing in microfluidic devices presents a challenge due to laminar flows in microchannels, which result from low Reynolds numbers determined by the channel’s hydraulic diameter, flow velocity, and solution’s kinetic viscosity. To address this challenge, novel methods of mixing enhancement within microfluidic devices have been explored for a variety of applications. Passive mixing methods have been created, including those using ridges or slanted wells within the microchannels, as well as their variations with improved performance by varying geometry and patterns, by changing the properties of channel surfaces, and by optimization via simulations. In addition, active mixing methods including microstirrers, acoustic mixers, and flow pulsation have been investigated and integrated into microfluidic devices to enhance mixing in a more controllable manner. In general, passive mixers are easy to integrate, but difficult to control externally by users after fabrication. Active mixers usually take efforts to integrate within a device and they require external components (e.g. power sources) to operate. However, they can be controlled by users to a certain degree for tuned mixing. In this article, we provide a general overview of a number of passive and active mixers, discuss their advantages and disadvantages, and make suggestions on choosing a mixing method for a specific need as well as advocate possible integration of key elements of passive and active mixers to harness the advantages of both types. PMID:26549938

  1. Mixing in colliding, ultrasonically levitated drops.

    PubMed

    Chainani, Edward T; Choi, Woo-Hyuck; Ngo, Khanh T; Scheeline, Alexander

    2014-02-18

    Lab-in-a-drop, using ultrasonic levitation, has been actively investigated for the last two decades. Benefits include lack of contact between solutions and an apparatus and a lack of sample cross-contamination. Understanding and controlling mixing in the levitated drop is necessary for using an acoustically levitated drop as a microreactor, particularly for studying kinetics. A pulsed electrostatic delivery system enables addition and mixing of a desired-volume droplet with the levitated drop. Measurement of mixing kinetics is obtained by high-speed video monitoring of a titration reaction. Drop heterogeneity is visualized as 370 nl of 0.25 M KOH (pH: 13.4) was added to 3.7 μL of 0.058 M HCl (pH: 1.24). Spontaneous mixing time is about 2 s. Following droplet impact, the mixed drop orbits the levitator axis at about 5 Hz during homogenization. The video's green channel (maximum response near 540 nm) shows the color change due to phenolphthalein absorption. While mixing is at least an order of magnitude faster in the levitated drop compared with three-dimensional diffusion, modulation of the acoustic waveform near the surface acoustic wave resonance frequency of the levitated drop does not substantially reduce mixing time.

  2. Mixing in microfluidic devices and enhancement methods.

    PubMed

    Ward, Kevin; Fan, Z Hugh

    2015-09-01

    Mixing in microfluidic devices presents a challenge due to laminar flows in microchannels, which result from low Reynolds numbers determined by the channel's hydraulic diameter, flow velocity, and solution's kinetic viscosity. To address this challenge, novel methods of mixing enhancement within microfluidic devices have been explored for a variety of applications. Passive mixing methods have been created, including those using ridges or slanted wells within the microchannels, as well as their variations with improved performance by varying geometry and patterns, by changing the properties of channel surfaces, and by optimization via simulations. In addition, active mixing methods including microstirrers, acoustic mixers, and flow pulsation have been investigated and integrated into microfluidic devices to enhance mixing in a more controllable manner. In general, passive mixers are easy to integrate, but difficult to control externally by users after fabrication. Active mixers usually take efforts to integrate within a device and they require external components (e.g. power sources) to operate. However, they can be controlled by users to a certain degree for tuned mixing. In this article, we provide a general overview of a number of passive and active mixers, discuss their advantages and disadvantages, and make suggestions on choosing a mixing method for a specific need as well as advocate possible integration of key elements of passive and active mixers to harness the advantages of both types.

  3. Mixing in microfluidic devices and enhancement methods

    NASA Astrophysics Data System (ADS)

    Ward, Kevin; Fan, Z. Hugh

    2015-09-01

    Mixing in microfluidic devices presents a challenge due to laminar flows in microchannels, which result from low Reynolds numbers determined by the channel’s hydraulic diameter, flow velocity, and solution’s kinetic viscosity. To address this challenge, novel methods of mixing enhancement within microfluidic devices have been explored for a variety of applications. Passive mixing methods have been created, including those using ridges or slanted wells within the microchannels, as well as their variations with improved performance by varying geometry and patterns, by changing the properties of channel surfaces, and by optimization via simulations. In addition, active mixing methods including microstirrers, acoustic mixers, and flow pulsation have been investigated and integrated into microfluidic devices to enhance mixing in a more controllable manner. In general, passive mixers are easy to integrate, but difficult to control externally by users after fabrication. Active mixers usually take efforts to integrate within a device and they require external components (e.g. power sources) to operate. However, they can be controlled by users to a certain degree for tuned mixing. In this article, we provide a general overview of a number of passive and active mixers, discuss their advantages and disadvantages, and make suggestions on choosing a mixing method for a specific need as well as advocate possible integration of key elements of passive and active mixers to harness the advantages of both types.

  4. Incomplete Mixing in a Small, Urban stream

    NASA Astrophysics Data System (ADS)

    Ryan, R. J.; Boufadel, M. C.

    2006-05-01

    Conservative solute tracer experiments were conducted in Indian Creek, a small urban stream located in Philadelphia, Pennsylvania, USA. Estimated flow rates were between 46 L s-1 and 81 L s-1, average stream width was 5.5 m and average stream depth was 0.2 m. Given these dimensions, most researchers would think it reasonable to assume that the stream is completely mixed vertically and horizontally. However, we found that the stream was not vertically completely mixed in a 0.95 m deep, 30 m long pool. The limited mixing was demonstrated by the vertical stratification of a tracer cloud which was completely mixed both laterally and vertically across the stream prior to entering the pool. We suggest that the cause of limited mixing is due to a balance between groundwater inflow and transverse dispersion at the cross section. We show that the unsupported assumption of complete mix may result in a wide range, and thus increased uncertainty, of the values of stream flow and longitudinal dispersion coefficient estimated from these data. We conclude that the assumption of complete mix and one-dimensional modeling must be checked against actual field conditions, even in small streams.

  5. Fast Mix Table Construction for Material Discretization

    SciTech Connect

    Johnson, Seth R

    2013-01-01

    An effective hybrid Monte Carlo--deterministic implementation typically requires the approximation of a continuous geometry description with a discretized piecewise-constant material field. The inherent geometry discretization error can be reduced somewhat by using material mixing, where multiple materials inside a discrete mesh voxel are homogenized. Material mixing requires the construction of a ``mix table,'' which stores the volume fractions in every mixture so that multiple voxels with similar compositions can reference the same mixture. Mix table construction is a potentially expensive serial operation for large problems with many materials and voxels. We formulate an efficient algorithm to construct a sparse mix table in $O(\\text{number of voxels}\\times \\log \\text{number of mixtures})$ time. The new algorithm is implemented in ADVANTG and used to discretize continuous geometries onto a structured Cartesian grid. When applied to an end-of-life MCNP model of the High Flux Isotope Reactor with 270 distinct materials, the new method improves the material mixing time by a factor of 100 compared to a naive mix table implementation.

  6. Fast mix table construction for material discretization

    SciTech Connect

    Johnson, S. R.

    2013-07-01

    An effective hybrid Monte Carlo-deterministic implementation typically requires the approximation of a continuous geometry description with a discretized piecewise-constant material field. The inherent geometry discretization error can be reduced somewhat by using material mixing, where multiple materials inside a discrete mesh voxel are homogenized. Material mixing requires the construction of a 'mix table,' which stores the volume fractions in every mixture so that multiple voxels with similar compositions can reference the same mixture. Mix table construction is a potentially expensive serial operation for large problems with many materials and voxels. We formulate an efficient algorithm to construct a sparse mix table in O(number of voxels x log number of mixtures) time. The new algorithm is implemented in ADVANTG and used to discretize continuous geometries onto a structured Cartesian grid. When applied to an end-of-life MCNP model of the High Flux Isotope Reactor with 270 distinct materials, the new method improves the material mixing time by a factor of 100 compared to a naive mix table implementation. (authors)

  7. Viscoelastic behaviour of cold recycled asphalt mixes

    NASA Astrophysics Data System (ADS)

    Cizkova, Zuzana; Suda, Jan

    2017-09-01

    Behaviour of cold recycled mixes depends strongly on both the bituminous binder content (bituminous emulsion or foamed bitumen) and the hydraulic binder content (usually cement). In the case of cold recycled mixes rich in bitumen and with low hydraulic binder content, behaviour is close to the viscoelastic behaviour of traditional hot mix asphalt. With decreasing bituminous binder content together with increasing hydraulic binder content, mixes are characteristic with brittle behaviour, typical for concrete pavements or hydraulically bound layers. The behaviour of cold recycled mixes with low content of both types of binders is similar to behaviour of unbound materials. This paper is dedicated to analysing of the viscoelastic behaviour of the cold recycled mixes. Therefore, the tested mixes contained higher amount of the bituminous binder (both foamed bitumen and bituminous emulsion). The best way to characterize any viscoelastic material in a wide range of temperatures and frequencies is through the master curves. This paper includes interesting findings concerning the dependency of both parts of the complex modulus (elastic and viscous) on the testing frequency (which simulates the speed of heavy traffic passing) and on the testing temperature (which simulates the changing climate conditions a real pavement is subjected to).

  8. Rate of chaotic mixing in localized flows

    NASA Astrophysics Data System (ADS)

    Jop, Pierre; Boujlel, Jalila; Gouillart, Emmanuelle; Pigeonneau, Franck; Surface du Verre et Interfaces Team

    2016-11-01

    Most of the pastes in building materials are yield-stress fluids. Mixing them efficiently is required for industrial processes but linking the rate of the mixing to the fluid properties is a challenge. We study experimentally the rate of chaotic mixing in viscoplastic fluids by using a rod-stirring protocol with a rotating vessel. Only a limited zone localized around the stirring rods is highly sheared at a given time. Using a dyed spot as the initial condition, we measure the decay of concentration fluctuations of dye as mixing proceeds. Due to numerical simulations and experimental measurements, we relate the volume of highly sheared fluid to the parameters of the flow. We propose a quantitative two-zone model for the mixing rate, taking into account the geometry of the highly sheared zone as well as the rate at which fluid is renewed inside this zone. The model predicts correctly the scaling of the exponential mixing rates during a first rapid stage and a second slower one. Moreover we show that an optimal mixing exists when varying the ratio of the rotation rate of the vessel and the velocity of the rods. French ANR (ANR-11-JS09-015).

  9. Finishing bacterial genome assemblies with Mix

    PubMed Central

    2013-01-01

    Motivation Among challenges that hamper reaping the benefits of genome assembly are both unfinished assemblies and the ensuing experimental costs. First, numerous software solutions for genome de novo assembly are available, each having its advantages and drawbacks, without clear guidelines as to how to choose among them. Second, these solutions produce draft assemblies that often require a resource intensive finishing phase. Methods In this paper we address these two aspects by developing Mix , a tool that mixes two or more draft assemblies, without relying on a reference genome and having the goal to reduce contig fragmentation and thus speed-up genome finishing. The proposed algorithm builds an extension graph where vertices represent extremities of contigs and edges represent existing alignments between these extremities. These alignment edges are used for contig extension. The resulting output assembly corresponds to a set of paths in the extension graph that maximizes the cumulative contig length. Results We evaluate the performance of Mix on bacterial NGS data from the GAGE-B study and apply it to newly sequenced Mycoplasma genomes. Resulting final assemblies demonstrate a significant improvement in the overall assembly quality. In particular, Mix is consistent by providing better overall quality results even when the choice is guided solely by standard assembly statistics, as is the case for de novo projects. Availability Mix is implemented in Python and is available at https://github.com/cbib/MIX, novel data for our Mycoplasma study is available at http://services.cbib.u-bordeaux2.fr/mix/. PMID:24564706

  10. Using mixed methods in health research

    PubMed Central

    Woodman, Jenny

    2013-01-01

    Summary Mixed methods research is the use of quantitative and qualitative methods in a single study or series of studies. It is an emergent methodology which is increasingly used by health researchers, especially within health services research. There is a growing literature on the theory, design and critical appraisal of mixed methods research. However, there are few papers that summarize this methodological approach for health practitioners who wish to conduct or critically engage with mixed methods studies. The objective of this paper is to provide an accessible introduction to mixed methods for clinicians and researchers unfamiliar with this approach. We present a synthesis of key methodological literature on mixed methods research, with examples from our own work and that of others, to illustrate the practical applications of this approach within health research. We summarize definitions of mixed methods research, the value of this approach, key aspects of study design and analysis, and discuss the potential challenges of combining quantitative and qualitative methods and data. One of the key challenges within mixed methods research is the successful integration of quantitative and qualitative data during analysis and interpretation. However, the integration of different types of data can generate insights into a research question, resulting in enriched understanding of complex health research problems. PMID:23885291

  11. Mixing of oxidized and bilayer phospholipids.

    PubMed

    Singh, Jasmeet; Ranganathan, Radha

    2015-07-01

    Composition and phase dependence of the mixing of 1,2-Dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and 1,2-Dioleoyl-sn-glycero-3-phosphocholine (DOPC), with the oxidized phospholipid, 1-palmitoyl-2-glutaryl-sn-glycero-3-phosphocholine (PGPC) were investigated by characterizing the aggregation states of DPPC/PGPC and DOPC/PGPC using a fluorescence quenching assay, dynamic light scattering, and time-resolved fluorescence quenching in the temperature range 5-60°C. PGPC forms 3.5nm radii micelles of aggregation number 33. In the gel phase, DPPC and PGPC fuse to form mixed vesicles for PGPC molar fraction, XPGPC≤0.3 and coexisting vesicles and micelles at higher XPGPC. Data suggest that liquid phase DPPC at 50°C forms mixed vesicles with segregated or hemi fused DPPC and PGPC for XPGPC≤0.3. At 60°C, DPPC and PGPC do not mix, but form coexisting vesicles and micelles. DOPC and PGPC do not mix in any proportion in the liquid phase. Two dissimilar aggregates of the sizes of vesicles and PGPC micelles were observed for all XPGPC for T≥22°C. DOPC-PGPC and DPPC-PGPC mixing is non-ideal for XPGPC>0.3 in both gel and fluid phases resulting in exclusion of PGPC from the bilayer. Formation of mixed vesicles is favored in the gel phase but not in the liquid phase for XPGPC≤0.3. For XPGPC≤0.3, aggregation states change progressively from mixed vesicles in the gel phase to component segregated mixed vesicles in the liquid phase close to the chain melting transition temperature to separated coexisting vesicles and micelles at higher temperatures. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Single particle diversity and mixing state measurements

    NASA Astrophysics Data System (ADS)

    Healy, R. M.; Riemer, N.; Wenger, J. C.; Murphy, M.; West, M.; Poulain, L.; Wiedensohler, A.; O'Connor, I. P.; McGillicuddy, E.; Sodeau, J. R.; Evans, G. J.

    2014-02-01

    A newly developed framework for quantifying aerosol particle diversity and mixing state based on information-theoretic entropy is applied for the first time to single particle mass spectrometry field data. Single particle mass fraction estimates for black carbon, organic aerosol, ammonium, nitrate and sulphate, derived using single particle mass spectrometer, aerosol mass spectrometer and multi-angle absorption photometer measurements are used to calculate single particle species diversity (Di). The average single particle species diversity (Dα) is then related to the species diversity of the bulk population (Dγ) to derive a mixing state index value (χ) at hourly resolution. The mixing state index is a single parameter representation of how internally/externally mixed a particle population is at a given time. The index describes a continuum, with values of 0% and 100% representing fully external and internal mixing, respectively. This framework was applied to data collected as part of the MEGAPOLI winter campaign in Paris, France 2010. Di values are low (∼2) for fresh traffic and woodburning particles that contain high mass fractions of black carbon and organic aerosol but low mass fractions of inorganic ions. Conversely, Di values are higher (∼4) for aged carbonaceous particles containing similar mass fractions of black carbon, organic aerosol, ammonium, nitrate and sulphate. Aerosol in Paris is estimated to be 59% internally mixed in the size range 150-1067 nm, and mixing state is dependent both upon time of day and air mass origin. Daytime primary emissions associated with vehicular traffic and woodburning result in low χ values, while enhanced condensation of ammonium nitrate on existing particles at night leads to higher χ values. Advection of particles from continental Europe containing ammonium, nitrate and sulphate leads to increases in Dα, Dγ and χ. The mixing state index represents a useful metric by which to compare and contrast ambient

  13. Single particle diversity and mixing state measurements

    NASA Astrophysics Data System (ADS)

    Healy, R. M.; Riemer, N.; Wenger, J. C.; Murphy, M.; West, M.; Poulain, L.; Wiedensohler, A.; O'Connor, I. P.; McGillicuddy, E.; Sodeau, J. R.; Evans, G. J.

    2014-06-01

    A newly developed framework for quantifying aerosol particle diversity and mixing state based on information-theoretic entropy is applied for the first time to single particle mass spectrometry field data. Single particle mass fraction estimates for black carbon, organic aerosol, ammonium, nitrate and sulfate, derived using single particle mass spectrometer, aerosol mass spectrometer and multi-angle absorption photometer measurements are used to calculate single particle species diversity (Di). The average single particle species diversity (Dα) is then related to the species diversity of the bulk population (Dγ) to derive a mixing state index value (χ) at hourly resolution. The mixing state index is a single parameter representation of how internally/externally mixed a particle population is at a given time. The index describes a continuum, with values of 0 and 100% representing fully external and internal mixing, respectively. This framework was applied to data collected as part of the MEGAPOLI winter campaign in Paris, France, 2010. Di values are low (~ 2) for fresh traffic and wood-burning particles that contain high mass fractions of black carbon and organic aerosol but low mass fractions of inorganic ions. Conversely, Di values are higher (~ 4) for aged carbonaceous particles containing similar mass fractions of black carbon, organic aerosol, ammonium, nitrate and sulfate. Aerosol in Paris is estimated to be 59% internally mixed in the size range 150-1067 nm, and mixing state is dependent both upon time of day and air mass origin. Daytime primary emissions associated with vehicular traffic and wood-burning result in low χ values, while enhanced condensation of ammonium nitrate on existing particles at night leads to higher χ values. Advection of particles from continental Europe containing ammonium, nitrate and sulfate leads to increases in Dα, Dγ and χ. The mixing state index represents a useful metric by which to compare and contrast ambient particle

  14. Dilution jet mixing program, phase 3

    NASA Technical Reports Server (NTRS)

    Srinivasan, R.; Coleman, E.; Myers, G.; White, C.

    1985-01-01

    The main objectives for the NASA Jet Mixing Phase 3 program were: extension of the data base on the mixing of single sided rows of jets in a confined cross flow to discrete slots, including streamlined, bluff, and angled injections; quantification of the effects of geometrical and flow parameters on penetration and mixing of multiple rows of jets into a confined flow; investigation of in-line, staggered, and dissimilar hole configurations; and development of empirical correlations for predicting temperature distributions for discrete slots and multiple rows of dilution holes.

  15. Tri-bimaximal Mixing from Cascades

    SciTech Connect

    Takahashi, Ryo

    2008-11-23

    We investigate fermion mass matrices of the cascade form which lead to the tri-bimaximal mixing in the lepton sector. The cascade neutrino matrix predicts a parameter-independent relation among the observables, which are the neutrino mixing angles and mass squared differences. The relation predicts that the atmospheric neutrino mixing angle is close to maximal. We also study phenomenological aspect of the cascade form in supersymmetric theory, which are lepton flavor violation and thermal leptogenesis. A dynamical realivation of the cascade mass matrix are also presented in U(1) flavor theory.

  16. A gas mixing device for MOCVD

    NASA Astrophysics Data System (ADS)

    Blaauw, C.; Miner, C. J.

    1987-08-01

    Epitaxial layers of Ga zIn 1- zAs have been grown in a horizontal, low pressure metalorganic chemical vapour deposition reactor, using a mixing manifold of radial symmetry. The effect of the inlet configuration of the reactant gases on the compositional uniformity of the layers has been investigated by photoluminescence spectroscopy. It was found that incomplete gas phase mixing of the reactants resulted in poor uniformity of the grown layers. By incorporating a mixing device in the gas line, which imparted a rotational component to the gas flow, epitaxial layer uniformities were markedly improved.

  17. Cutaneous mucinosis in mixed connective tissue disease.

    PubMed

    Favarato, Maria Helena Sampaio; Miranda, Sofia Silveira de Castro; Caleiro, Maria Teresa Correia; Assad, Ana Paula Luppino; Halpern, Ilana; Fuller, Ricardo

    2013-01-01

    Cutaneous mucinosis is a group of conditions involving an accumulation of mucin or glycosaminoglycan in the skin and its annexes. It is described in some connective tissue diseases but never in association with mixed connective tissue disease. This report concerns two cases of cutaneous mucinosis in patients with mixed connective tissue disease in remission; one patient presented the papular form, and the other reticular erythematous mucinosis. These are the first cases of mucinosis described in mixed connective tissue disease. Both cases had skin lesions with no other clinical or laboratorial manifestations, with clinical response to azathioprine in one, and to an association of chloroquine and prednisone in the other.

  18. B mixing and flavor tagging at CDF

    SciTech Connect

    Russ, James S.; /Carnegie Mellon U.

    2004-12-01

    The CDF Collaboration has made a preliminary measurement of B{sub d} mixing as a first step toward measuring mixing in the B{sub s} system. Flavor tagging using opposite-side jets and muons as well as same-side tagging schemes have been applied. Results agree well with precise results from the B-factories. They use these results to estimate CDF's B{sub s} mixing range using the present data set ({approx} 250 pb{sup -1}) and extrapolate to the potential from larger data sets in future running.

  19. Gaussian ensembles distributions from mixing quantum systems

    NASA Astrophysics Data System (ADS)

    Gomez, Ignacio S.; Portesi, M.

    2017-08-01

    In the context of dynamical systems we present a derivation of the Gaussian ensembles distributions from quantum systems having a classical analogue that is mixing. We find that factorization property is satisfied for the mixing quantum systems expressed as a factorization of quantum mean values. For the case of the kicked rotator and in its fully chaotic regime, the factorization property links decoherence by dephasing with Gaussian ensembles in terms of the weak limit, interpreted as a decohered state. Moreover, a discussion about the connection between random matrix theory and quantum chaotic systems, based on some attempts made in previous works and from the viewpoint of the mixing quantum systems, is presented.

  20. Mixed Method Designs in Implementation Research

    PubMed Central

    Aarons, Gregory A.; Horwitz, Sarah; Chamberlain, Patricia; Hurlburt, Michael; Landsverk, John

    2010-01-01

    This paper describes the application of mixed method designs in implementation research in 22 mental health services research studies published in peer-reviewed journals over the last 5 years. Our analyses revealed 7 different structural arrangements of qualitative and quantitative methods, 5 different functions of mixed methods, and 3 different ways of linking quantitative and qualitative data together. Complexity of design was associated with number of aims or objectives, study context, and phase of implementation examined. The findings provide suggestions for the use of mixed method designs in implementation research. PMID:20967495

  1. Mixed method designs in implementation research.

    PubMed

    Palinkas, Lawrence A; Aarons, Gregory A; Horwitz, Sarah; Chamberlain, Patricia; Hurlburt, Michael; Landsverk, John

    2011-01-01

    This paper describes the application of mixed method designs in implementation research in 22 mental health services research studies published in peer-reviewed journals over the last 5 years. Our analyses revealed 7 different structural arrangements of qualitative and quantitative methods, 5 different functions of mixed methods, and 3 different ways of linking quantitative and qualitative data together. Complexity of design was associated with number of aims or objectives, study context, and phase of implementation examined. The findings provide suggestions for the use of mixed method designs in implementation research.

  2. Strong intrinsic mixing in vortex magnetic fields.

    PubMed

    Martin, James E; Shea-Rohwer, Lauren; Solis, Kyle J

    2009-07-01

    We report a method of magnetic mixing wherein a "vortex" magnetic field applied to a suspension of magnetic particles creates strong homogeneous mixing throughout the fluid volume. Experiments designed to elucidate the microscopic mechanism of mixing show that the torque is quadratic in the field, decreases with field frequency, and is optimized at a vortex field angle of approximately 55 degrees . Theory and simulations indicate that the field-induced formation of volatile particle chains is responsible for these phenomena. This technique has applications in microfluidic devices and is ideally suited to applications such as accelerating the binding of target biomolecules to biofunctionalized magnetic microbeads.

  3. Cutaneous mucinosis in mixed connective tissue disease*

    PubMed Central

    Favarato, Maria Helena Sampaio; Assad, Ana Paula Luppino; Miranda, Sofia Silveira de Castro; Halpern, Ilana; Caleiro, Maria Teresa Correia; Fuller, Ricardo

    2013-01-01

    Cutaneous mucinosis is a group of conditions involving an accumulation of mucin or glycosaminoglycan in the skin and its annexes. It is described in some connective tissue diseases but never in association with mixed connective tissue disease. This report concerns two cases of cutaneous mucinosis in patients with mixed connective tissue disease in remission; one patient presented the papular form, and the other reticular erythematous mucinosis. These are the first cases of mucinosis described in mixed connective tissue disease. Both cases had skin lesions with no other clinical or laboratorial manifestations, with clinical response to azathioprine in one, and to an association of chloroquine and prednisone in the other. PMID:24068142

  4. Laboratory studies of ocean mixing by microorganisms

    NASA Astrophysics Data System (ADS)

    Martinez-Ortiz, Monica; Dabiri, John O.

    2011-11-01

    Ocean mixing plays a major role in nutrient and energy transport and is an important input to climate models. Recent studies suggest that the contribution of fluid transport by swimming microorganisms to ocean mixing may be of the same order of magnitude as winds and tides. An experimental setup has been designed in order to study the mixing efficiency of vertical migration of plankton. To this end, a stratified water column is created to model the ocean's density gradient. The vertical migration of Artemia Salina (brine shrimp) within the water column is controlled via luminescent signals on the top and bottom of the column. By fluorescently labelling portions of the water column, the stirring of the density gradient by the animals is visualized and quantified. Preliminary results show that the vertical movement of these organisms produces enhanced mixing relative to control cases in which only buoyancy forces and diffusion are present.

  5. Neutrino masses, mixing, moments, and matter

    SciTech Connect

    Marciano, W.J.

    1988-01-01

    The present status of neutrino masses, mixing, and electromagnetic moments is surveyed. Potential enhancements of neutrino oscillations, decay, and spin-flavor precession due to their interactions with matter are described.

  6. Mixing Times in Evolutionary Game Dynamics

    NASA Astrophysics Data System (ADS)

    Black, Andrew J.; Traulsen, Arne; Galla, Tobias

    2012-07-01

    Without mutation and migration, evolutionary dynamics ultimately leads to the extinction of all but one species. Such fixation processes are well understood and can be characterized analytically with methods from statistical physics. However, many biological arguments focus on stationary distributions in a mutation-selection equilibrium. Here, we address the mixing time required to reach stationarity in the presence of mutation. We show that mixing times in evolutionary games have the opposite behavior from fixation times when the intensity of selection increases: in coordination games with bistabilities, the fixation time decreases, but the mixing time increases. In coexistence games with metastable states, the fixation time increases, but the mixing time decreases. Our results are based on simulations and the Wentzel-Kramers-Brillouin approximation of the master equation.

  7. Hawaii Ocean Mixing Experiment: Program Summary

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Chao, Benjamin F. (Technical Monitor)

    2002-01-01

    It is becoming apparent that insufficient mixing occurs in the pelagic ocean to maintain the large scale thermohaline circulation. Observed mixing rates fall a factor of ten short of classical indices such as Munk's "Abyssal Recipe." The growing suspicion is that most of the mixing in the sea occurs near topography. Exciting recent observations by Polzin et al., among others, fuel this speculation. If topographic mixing is indeed important, it must be acknowledged that its geographic distribution, both laterally and vertically, is presently unknown. The vertical distribution of mixing plays a critical role in the Stommel Arons model of the ocean interior circulation. In recent numerical studies, Samelson demonstrates the extreme sensitivity of flow in the abyssal ocean to the spatial distribution of mixing. We propose to study the topographic mixing problem through an integrated program of modeling and observation. We focus on tidally forced mixing as the global energetics of this process have received (and are receiving) considerable study. Also, the well defined frequency of the forcing and the unique geometry of tidal scattering serve to focus the experiment design. The Hawaiian Ridge is selected as a study site. Strong interaction between the barotropic tide and the Ridge is known to take place. The goals of the Hawaiian Ocean Mixing Experiment (HOME) are to quantify the rate of tidal energy loss to mixing at the Ridge and to identify the mechanisms by which energy is lost and mixing generated. We are challenged to develop a sufficiently comprehensive picture that results can be generalized from Hawaii to the global ocean. To achieve these goals, investigators from five institutions have designed HOME, a program of historic data analysis, modeling and field observation. The Analysis and Modeling efforts support the design of the field experiments. As the program progresses, a global model of the barotropic (depth independent) tide, and two models of the

  8. Fermion masses, flavour mixing and CP violation

    SciTech Connect

    Ross, G. G.

    2008-11-23

    The pattern of neutrino masses and mixings is characteristically different from those observed in the quark sector. I discuss how this can be elegantly explaned through a combination of an underlying family symmetry and the see-saw mechanism.

  9. Mixing lengths scaling in a gravity flow

    SciTech Connect

    Ecke, Robert E; Rivera, Micheal; Chen, Jun; Ecke, Robert E

    2009-01-01

    We present an experimental study of the mixing processes in a gravity current. The turbulent transport of momentum and buoyancy can be described in a very direct and compact form by a Prandtl mixing length model [1]: the turbulent vertical fluxes of momentum and buoyancy are found to scale quadraticatly with the vertical mean gradients of velocity and density. The scaling coefficient is the square of the mixing length, approximately constant over the mixing zone of the stratified shear layer. We show in this paper how, in different flow configurations, this length can be related to the shear length of the flow {radical}({var_epsilon}/{partial_derivative}{sub z}u{sup 3}).

  10. Hardy's criterion of nonlocality for mixed states

    SciTech Connect

    Ghirardi, GianCarlo; Marinatto, Luca

    2006-03-15

    We generalize Hardy's proof of nonlocality to the case of bipartite mixed statistical operators, and we exhibit a necessary condition which has to be satisfied by any given mixed state {sigma} in order that a local and realistic hidden variable model exists which accounts for the quantum mechanical predictions implied by {sigma}. Failure of this condition will imply both the impossibility of any local explanation of certain joint probability distributions in terms of hidden variables and the nonseparability of the considered mixed statistical operator. Our result can be also used to determine the maximum amount of noise, arising from imperfect experimental implementations of the original Hardy's proof of nonlocality, in presence of which it is still possible to put into evidence the nonlocal features of certain mixed states.

  11. Training Teachers for Mixed Ability Classes

    ERIC Educational Resources Information Center

    Wragg, E. C.

    1978-01-01

    Discusses the preparation of student teachers for mixed ability classes, based on the Nottingham/Leicester project. Outlines a ten-point attack highlighting the areas in which young teachers need to acquire professional skills. (Author/RK)

  12. Plasma kinetic effects on interfacial mix

    NASA Astrophysics Data System (ADS)

    Yin, L.; Albright, B. J.; Taitano, W.; Vold, E. L.; Chacon, L.; Simakov, A. N.

    2016-11-01

    Mixing at interfaces in dense plasma media is a problem central to inertial confinement fusion and high energy density laboratory experiments. In this work, collisional particle-in-cell simulations are used to explore kinetic effects arising during the mixing of unmagnetized plasma media. Comparisons are made to the results of recent analytical theory in the small Knudsen number limit and while the bulk mixing properties of interfaces are in general agreement, some differences arise. In particular, "super-diffusive" behavior, large diffusion velocity, and large Knudsen number are observed in the low density regions of the species mixing fronts during the early evolution of a sharp interface prior to the transition to a slow diffusive process in the small-Knudsen-number limit predicted by analytical theory. A center-of-mass velocity profile develops as a result of the diffusion process and conservation of momentum.

  13. Mixed waste minimization in a research environment

    SciTech Connect

    Kirner, N.

    1994-12-31

    This presentation describes minimization efforts and processes for mixed waste generated by research facilities. Waste stream assessment and treatment, and database management for various research-related waste streams is detailed.

  14. A colorimetric reaction to quantify fluid mixing

    NASA Astrophysics Data System (ADS)

    Oates, Peter M.; Harvey, Charles F.

    2006-11-01

    We found the colorimetric reaction of Tiron (1,2-dihydroxybenzene-3,5-disulfonic acid) and molybdate suitable for optical quantification of chemical reaction during fluid-fluid mixing in laboratory chambers. This reaction consists of two colorless reagents that mix to rapidly form colored, stable, soluble products. These products can be digitally imaged and quantified using light absorbance to study fluid-fluid mixing. Here we provide a model and equilibrium constants for the relevant complexation reactions. We also provide methods for relating light absorbance to product concentrations. Practical implementation issues of this reaction are discussed and an example of imaged absorbances for fluid-fluid mixing in heterogeneous porous media is given.

  15. Hawaii Ocean Mixing Experiment: Program Summary

    NASA Technical Reports Server (NTRS)

    Ray, Richard D.; Chao, Benjamin F. (Technical Monitor)

    2002-01-01

    It is becoming apparent that insufficient mixing occurs in the pelagic ocean to maintain the large scale thermohaline circulation. Observed mixing rates fall a factor of ten short of classical indices such as Munk's "Abyssal Recipe." The growing suspicion is that most of the mixing in the sea occurs near topography. Exciting recent observations by Polzin et al., among others, fuel this speculation. If topographic mixing is indeed important, it must be acknowledged that its geographic distribution, both laterally and vertically, is presently unknown. The vertical distribution of mixing plays a critical role in the Stommel Arons model of the ocean interior circulation. In recent numerical studies, Samelson demonstrates the extreme sensitivity of flow in the abyssal ocean to the spatial distribution of mixing. We propose to study the topographic mixing problem through an integrated program of modeling and observation. We focus on tidally forced mixing as the global energetics of this process have received (and are receiving) considerable study. Also, the well defined frequency of the forcing and the unique geometry of tidal scattering serve to focus the experiment design. The Hawaiian Ridge is selected as a study site. Strong interaction between the barotropic tide and the Ridge is known to take place. The goals of the Hawaiian Ocean Mixing Experiment (HOME) are to quantify the rate of tidal energy loss to mixing at the Ridge and to identify the mechanisms by which energy is lost and mixing generated. We are challenged to develop a sufficiently comprehensive picture that results can be generalized from Hawaii to the global ocean. To achieve these goals, investigators from five institutions have designed HOME, a program of historic data analysis, modeling and field observation. The Analysis and Modeling efforts support the design of the field experiments. As the program progresses, a global model of the barotropic (depth independent) tide, and two models of the

  16. [Determination of taste sensitivity with mixed solutions].

    PubMed

    Marco Algarra, R

    1990-01-01

    In the second part of our study we present the results of the mixture of four basic tastes in comparison with those of the simple solutions, mea ng as well the fatigue phenomenon with the mixed solutions.

  17. Microbiology: Mixing Wine, Chocolate, and Coffee.

    PubMed

    Goddard, Matthew R

    2016-04-04

    Yeasts associated with cocoa and coffee beans are genetically distinct. These populations have been created through the migration and mixing of populations associated with vineyards, trees in America, and the ancestral seat of this species in Far East Asia.

  18. Helicity in supercritical temporal mixing layers

    NASA Technical Reports Server (NTRS)

    Bellan, J.; Okong'o, N.

    2003-01-01

    Databases of transitional states obtained from Direct Numerical Simulations (DNS) of temporal, supercritical mixing layers for two species systems, 02/H2 and C7Hle/N2, are analyzed to elucidate species-specific turbulence aspects.

  19. Chaotic Mixing of Granitic and Basaltic Liquids

    NASA Astrophysics Data System (ADS)

    Decampos, C.; Ingrisch, W. E.; Perugini, D.; Dingwell, D. B.; Poli, G.

    2008-12-01

    Chaotic mixing in magma chambers may play a central role in determining the timing and dynamics of volcanic eruptions. The dynamics of such chaotic mixing has been investigated solely in analog systems and in numerical simulations to date. Here we report the first experimental study of the dynamics of chaotic mixing in molten silicates of geological relevance. A newly developed device for the simulation of chaotic dynamics has been successfully employed for this purpose. Its development is based on the importance of chaotic dynamics for mixing processes; and previous studies evidencing that chaotic dynamics could equally control magma mixing processes in nature (Perugini et al., 2006. EPSL, 234: 669-680 and references therein). The special device for chaotic mixing silicate melts at high temperatures (up to 1700°C) has been built after the journal-bearing or eccentric-cylinder geometry for viscous fluids for the study of chaotic mixing in slow flows (Swanson and Ottino, 1990. J. Fluid Mech., 213:227-249). In order to generate chaos in a flow, the streamlines must be time dependent, resulting from alternating movements between the two cylinders. The mixing experiments were performed using end-members of: haplogranite [In wt.%: SiO2(71.6), Al2O3(12.4), Na2O(7.0), K2O(9.0)] and haplobasalt [SiO2(48.6), Al2O3(16.3), CaO(23.8), MgO (11.4)]. The haplogranite was doped with trace amounts of Rb, Sr, Ba, Zr and REE oxides. The experimental protocol started with a single run of alternating movements of spindle and crucible. It lasted for 110 minutes at a temperature of 1400°C. The experiment terminated by stopping all movement and letting the sample cool to room temperature. A cylinder of the resultant mixed glassy sample was recovered by drilling. Horizontal sections of this cylinder at varying heights were prepared for microprobe and ICP-MS- Laser Ablation analyses. Preliminary optical and microprobe studies reveal crystal-free filaments of intermediary compositions

  20. Enhanced Mixing in a Rectangular Duct

    NASA Technical Reports Server (NTRS)

    Liscinsky, D. S.; True, B.

    2003-01-01

    An experimental investigation of the mixing of non-reacting opposed rows of jets injected normal to a confined rectangular crossflow has been conducted. Planar Mie-scattering was used to measure the time-average concentration distribution of the jet fluid in planes perpendicular to the duct axis. Particular emphasis was placed on the study of closely spaced orifice configurations applicable to the mixing zone of an RQL combustor. Baseline studies were performed of mixing under "ideal" conditions, i.e., plenum fed jets injecting into a crossflow uniform in velocity and turbulence intensity. In addition, more practical ("non-ideal") issues encountered during hardware design were also studied. As in other studies, mixing effectiveness, determined using a spatial unmixedness parameter based on the variance of mean jet concentration distributions, was found to be optimum when the spacing-to-duct-height ratio was inversely proportional to the square root of the jet-to-mainstream momentum-flux ratio. This relationship is suitable for design under ideal flow conditions. Inlet flow boundary conditions of the jet and approach flow (mainstream) were found to strongly influence mixing performance, but no attempt was made to determine optimum performance under non-ideal conditions. The tests performed do offer some guidance as to expected mixing behavior for several common variables likely to be imposed by hardware constraints. Additionally, in this study it was found that for rows of orifices with opposite centerlines inline, mixing was similar for blockages up to 89 percent (previous crossflow mixing studies concerned with dilution zone configurations, blockages were typically less than 50 percent). Lower levels of unmixedness were obtained as a function of downstream location when axial injection length was minimized. Mixing may be enhanced if orifice centerlines of opposed rows are staggered, but blockage must be =50 percent in this configuration. Round hole and "square

  1. Quantum Darwinism for mixed-state environment

    NASA Astrophysics Data System (ADS)

    Quan, Haitao; Zwolak, Michael; Zurek, Wojciech

    2009-03-01

    We exam quantum darwinism when a system is in the presence of a mixed environment, and we find a general relation between the mutual information for the mixed-state environment and the change of the entropy of the fraction of the environment. We then look at a particular solvable model, and we numerically exam the time evolution of the ``mutual information" for large environment. Finally we discuss about the exact expressions for all entropies and the mutual information at special time.

  2. Mixed oxide nanoparticles and method of making

    DOEpatents

    Lauf, Robert J.; Phelps, Tommy J.; Zhang, Chuanlun; Roh, Yul

    2002-09-03

    Methods and apparatus for producing mixed oxide nanoparticulates are disclosed. Selected thermophilic bacteria cultured with suitable reducible metals in the presence of an electron donor may be cultured under conditions that reduce at least one metal to form a doped crystal or mixed oxide composition. The bacteria will form nanoparticles outside the cell, allowing easy recovery. Selection of metals depends on the redox potentials of the reducing agents added to the culture. Typically hydrogen or glucose are used as electron donors.

  3. Chemical Reactions in Turbulent Mixing Flows

    DTIC Science & Technology

    1993-07-15

    investigations of turbulent mixing, chemical reaction and combustion processes in turbulent, subsonic and supersonic flows. The program was comprised of...34) n•4I Abstract The purpose of this research is to conduct fundamental investigations of tur- bulent mixing, chemical reaction and combustion processes ...Another issue to consider is that different data- processing used on the different sets of data might result in differences between sets of data. To this end

  4. B lifetimes and mixing with the SLD

    SciTech Connect

    1995-12-01

    The lifetimes of B{sup 0} and B{sup {plus_minus}} mesons have been measured with the SLD detector at the SLC using topological reconstructions of the B mesons. Studies of B{sub s} mixing, using similar techniques, show that the prospects for measuring B{sub s} mixing with an upgraded vertex detector are good if x{sub x} {le} 15.

  5. Nonadditive Mixed State Phases in Neutron Optics

    SciTech Connect

    Klepp, J.; Sponar, S.; Filipp, S.; Lettner, M.; Badurek, G.; Hasegawa, Y.

    2009-03-10

    In a neutron polarimetry experiment mixed neutron spin phases are determined. We consider evolutions leading to purely geometric, purely dynamical and combined phases. It is experimentally demonstrated that the sum of the geometric and dynamical phases--both obtained in separate measurements--is not equal to the associated total phase as obtained from a third measurement, unless the system is in a pure state. In this sense, mixed state phases are not additive.

  6. The mixed waste landfill integrated demonstration

    SciTech Connect

    Burford, T.D.; Williams, C.V.

    1994-05-01

    The Mixed Waste Landfill Integrated Demonstration (MWLID) focuses on ``in-situ`` characterization, monitoring, remediation, and containment of landfills in arid environments that contain hazardous and mixed waste. The MWLID mission is to assess, demonstrate, and transfer technologies and systems that lead to faster, better, cheaper, and safer cleanup. Most important, the demonstrated technologies will be evaluated against the baseline of conventional technologies and systems. The comparison will include the cost, efficiency, risk, and feasibility of using these innovative technologies at other sites.

  7. Entry Times Distribution for Mixing Systems

    NASA Astrophysics Data System (ADS)

    Haydn, N.; Yang, F.

    2016-04-01

    We consider the return times dynamics to Bowen balls for continuous maps on metric spaces which have invariant probability measures with certain mixing properties. These mixing properties are satisfied for instance by systems that allow Young tower constructions. We show that the higher order return times to Bowen balls are in the limit Poisson distributed. We also provide a general result for the asymptotic behavior of the recurrence time for Bowen balls for ergodic systems and those with specification.

  8. Quick-Mixing Studies Under Reacting Conditions

    NASA Technical Reports Server (NTRS)

    Leong, May Y.; Samuelsen, G. S.

    1996-01-01

    The low-NO(x) emitting potential of rich-burn/quick-mix/lean-burn )RQL) combustion makes it an attractive option for engines of future stratospheric aircraft. Because NO(x) formation is exponentially dependent on temperature, the success of the RQL combustor depends on minimizing high temperature stoichiometric pocket formation in the quick-mixing section. An experiment was designed and built, and tests were performed to characterize reaction and mixing properties of jets issuing from round orifices into a hot, fuel-rich crossflow confined in a cylindrical duct. The reactor operates on propane and presents a uniform, non-swirling mixture to the mixing modules. Modules consisting of round orifice configurations of 8, 9, 10, 12, 14, and 18 holes were evaluated at a momentum-flux ratio of 57 and jet-to-mainstream mass-flaw ratio of 2.5. Temperatures and concentrations of O2, CO2, CO, HC, and NO(x) were obtained upstream, down-stream, and within the orifice plane to determine jet penetration as well as reaction processes. Jet penetration was a function of the number of orifices and affected the mixing in the reacting system. Of the six configurations tested, the 14-hole module produced jet penetration close to the module half-radius and yielded the best mixing and most complete combustion at a plane one duct diameter from the orifice leading edge. The results reveal that substantial reaction and heat release occur in the jet mixing zone when the entering effluent is hot and rich, and that the experiment as designed will serve to explore satisfactorily jet mixing behavior under realistic reacting conditions in future studies.

  9. Techniques for Bs Mixing at CDF

    SciTech Connect

    Salamanna, Giuseppe; /Rome U. /INFN, Rome

    2005-12-01

    The techniques used to perform a measurement of the mixing frequency of the B{sub s} meson ({Delta}M{sub s}) with the CDF detector at the TeVatron collider are described. Particular stress is put on CDF techniques for flavor tagging, which is possibly the major issue for mixing measurements at a hadron collider. Also CDF performances on lifetime and final state reconstruction are described. The final result of the amplitude scanning presented at 2005 Winter Conferences is reported.

  10. Mixing gasdynamic laser with nonequilibrium arc excitation

    NASA Astrophysics Data System (ADS)

    Antonov, G. G.; Kovshechnikov, V. B.; Rutberg, F. G.

    2016-05-01

    A mixing gasdynamic laser with nonuniform arc excitation is investigated using a model setup. Tentative analysis of the results indicates the appropriateness of using plasmatrons to improve the efficiency of mixing gasdynamic lasers by making carbon dioxide molecules vibrationally more nonuniform. In addition, a plasmatron serves as a preionization source both for a fast-flow gas-discharge laser and for a gasdynamic laser with combined pumping.

  11. Supersonic mixing and combustion in scramjets

    NASA Technical Reports Server (NTRS)

    Northam, G. B.; Capriotti, D. P.; Byington, C. S.; Greenberg, I.

    1991-01-01

    Experimental and theoretical studies are being conducted to explore techniques to enhance mixing in scramjet combustors using parallel fuel injection from the base of swept and unswept wall-mounted ramps. The experiments reported herein were conducted using Mach 2 and 3 combustor inlet conditions. Supporting computational and cold flow studies indicated that the observed enhanced mixing for the swept ramp configuration is primarily due to the substantially higher degree of vorticity and entrainment generated by the swept trailing edges.

  12. Microwave mixing with niobium variable thickness bridges

    NASA Technical Reports Server (NTRS)

    Wang, L.-K.; Callegari, A.; Deaver, B. S., Jr.

    1977-01-01

    Niobium thin-film bridges 300-A thick, 1-micron wide, and 0.5-micron long joining two bulk films 5000-A thick and having normal resistance of the order of 1 ohm have been fabricated and used for microwave mixing at 10 GHz. They exhibit Josephson, bolometric, and multiple-flux-flow mixing and have useful response at 100-200 GHz. The data show in a direct way limitations imposed by flux flow and heating.

  13. [Hadamard transform spectrometer mixed pixels' unmixing method].

    PubMed

    Yan, Peng; Hu, Bing-Liang; Liu, Xue-Bin; Sun, Wei; Li, Li-Bo; Feng, Yu-Tao; Liu, Yong-Zheng

    2011-10-01

    Hadamard transform imaging spectrometer is a multi-channel digital transform spectrometer detection technology, this paper based on digital micromirror array device (DMD) of the Hadamard transform spectrometer working principle and instrument structure, obtained by the imaging sensor mixed pixel were analyzed, theory derived the solution of pixel aliasing hybrid method, simulation results show that the method is simple and effective to improve the accuracy of mixed pixel spectrum more than 10% recovery.

  14. Transcortical mixed aphasia with left frontoparietal lesions.

    PubMed

    Maeshima, S; Uematsu, Y; Terada, T; Nakai, K; Itakura, T; Komai, N

    1996-05-01

    We present a case of transcortical mixed aphasia following a left frontoparietal infarct caused by vasospasm after subarachnoid haemorrhage. Although CT showed low-density areas in the left frontal lobe and basal ganglia, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere, except for the left perisylvian speech areas. Hence, transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas due to disconnection from surrounding areas.

  15. Mixing insert for foam dispensing apparatus

    NASA Technical Reports Server (NTRS)

    Simpson, W. G. (Inventor)

    1976-01-01

    A device for mixing foam ingredients is described. The device comprises an arrangement of lands situated about a cylindrical elongated shaft-like member with each land having a slot. The slots of alternate lands are positioned 180 deg from each other so that as the ingredients flow through the mixing chamber they flow from adjacent one side of the housing to the other dividing as such passes around the shaft-like member.

  16. Convective stretching and applications to mantle mixing

    NASA Astrophysics Data System (ADS)

    Conjeepurm Subramanian, Natarajan

    In this dissertation I have developed a method to quantify the stretching and orientation of infinitesimal strain ellipsoids in three-dimensional, incompressible, and unsteady flow fields. The method is used to study the mixing properties of various mantle-like flows. Chapter 1 provides a introduction to the dissertation. In Chapter 2, I discuss the mixing properties of a three-dimensional, unsteady flow in which the time dependence and three-dimensionality of the flow can be varied independently. It is found that the time dependance of the flow is a more important control on mixing. In Chapter 3, I discuss the mixing properties in a plate-driven model of mantle convection which generates both toroidal, and poloidal components in the velocity field. It is found that as the toroidal energy in the flow is increased to match the poloidal energy, the mixing becomes more homogeneous. Computing the frequency-size distribution of the stretching experienced by the heterogeneities it is found that the marble cake structure is the most likely structure for the upper mantle. In Chapter 4, I discuss the mixing properties of iso-viscous, steady, thermal convection models at infinite Prandtl number. It is found that the strain rate in these models scales uniformly as Ra-0.55. The strain rate scaling law was used to compute the mixing time in the models. The mixing time for these models was computed as ˜ 410 My for whole mantle convection and ˜ 25 My for layered mantle convection for Ra = 1x108 and ˜ 1.4 By and ˜ 100 My for Ra = 1 x 107. As in the previous chapter, the frequency size distribution corresponding to the stretching values indicates a marble cake structure for the upper mantle. In Chapter 5, I conclude the dissertation.

  17. Robotics for mixed waste operations, demonstration description

    SciTech Connect

    Ward, C.R.

    1993-11-01

    The Department of Energy (DOE) Office of Technology Development (OTD) is developing technology to aid in the cleanup of DOE sites. Included in the OTD program are the Robotics Technology Development Program and the Mixed Waste Integrated Program. These two programs are working together to provide technology for the cleanup of mixed waste, which is waste that has both radioactive and hazardous constituents. There are over 240,000 cubic meters of mixed low level waste accumulated at DOE sites and the cleanup is expected to generate about 900,000 cubic meters of mixed low level waste over the next five years. This waste must be monitored during storage and then treated and disposed of in a cost effective manner acceptable to regulators and the states involved. The Robotics Technology Development Program is developing robotics technology to make these tasks safer, better, faster and cheaper through the Mixed Waste Operations team. This technology will also apply to treatment of transuranic waste. The demonstration at the Savannah River Site on November 2-4, 1993, showed the progress of this technology by DOE, universities and industry over the previous year. Robotics technology for the handling, characterization and treatment of mixed waste as well robotics technology for monitoring of stored waste was demonstrated. It was shown that robotics technology can make future waste storage and waste treatment facilities better, faster, safer and cheaper.

  18. Characterization of Mixing Between Water and Biofuels

    NASA Astrophysics Data System (ADS)

    Cotel, Aline; Green, Erica; Acevedo, Marina; Otero, Margarita; Demond, Avery

    2012-11-01

    Currently, gasoline containing ethanol is considered to be among the best alternatives to gasoline. However, the potential environmental impact of a spill of ethanol-based biofuels on aquatic environments is an area of open discussion and research. Since these fuels are a combination of a miscible fluid (ethanol) and an immiscible fluid (gasoline), models used for traditional gasoline fuels (immiscible in water) are not applicable. Preliminary experiments show that when a solution of ethanol and glycol is mixed with water, a third mixed fluid is formed. Two distinct mixing regimes were observed. An exothermic reaction also occurred between ethanol and water. In the first regime, a turbulent wake is created between the ethanol/glycol and water layers causing the ethanol and glycol solution to entrain and mix into with the water phase. Because the mixed fluid is denser than either parent fluid, a dramatic overturning is possible. The amount of mixing was found to be dependent upon the initial ratio of ethanol to glycol in the parent fluid. The second regime begins when the turbulent wake has dissipated and the internal wave created by the plate has begun to settle, typically within the first minute. At this point, Bénard-like cells, similar to those typically seen in Rayleigh-Bénard convection, form at the interface and relatively slow mass transfer is evident. The cells at the interface show distinct features of interfacial turbulence, including small transverse waves, denoting that instabilities exist there. Funding from UM-OVPR and NSF Advance.

  19. Transversal mixing in the gastrointestinal tract

    NASA Astrophysics Data System (ADS)

    Vainchtein, Dmitri; Orthey, Perry; Parkman, Henry

    2015-11-01

    We discuss results of numerical simulations and analytical modeling of transversal intraluminal mixing in the GI tract produced by segmentation and peristaltic contractions. Particles that start in different parts of the small intestine are traced over several contractions and mixing is described using the particles' probability distribution function. We show that there is optimal set of parameters of contractions, such as the depth and frequency, that produces the most efficient mixing. We show that contractions create well-defined advection patterns in transversal direction. The research is inspired by several applications. First, there is the study of bacteria populating the walls of the intestine, which rely on fluid mixing for nutrients. Second, there are gastrointestinal diseases, such as Crohn's disease, which can be treated effectively using a drug delivery capsule through GI tract, for which it is needed to know how long it takes for a released drug to reach the intestinal wall. And finally, certain neurological and muscular deceases change the parameters of contractions, thus reducing the efficiency of mixing. Understanding an admissible range of the parameters (when mixing is still sufficient for biological purposes) may indicate when the medical action is required.

  20. Visualizing turbulent mixing of gases and particles

    NASA Technical Reports Server (NTRS)

    Ma, Kwan-Liu; Smith, Philip J.; Jain, Sandeep

    1995-01-01

    A physical model and interactive computer graphics techniques have been developed for the visualization of the basic physical process of stochastic dispersion and mixing from steady-state CFD calculations. The mixing of massless particles and inertial particles is visualized by transforming the vector field from a traditionally Eulerian reference frame into a Lagrangian reference frame. Groups of particles are traced through the vector field for the mean path as well as their statistical dispersion about the mean position by using added scalar information about the root mean square value of the vector field and its Lagrangian time scale. In this way, clouds of particles in a turbulent environment are traced, not just mean paths. In combustion simulations of many industrial processes, good mixing is required to achieve a sufficient degree of combustion efficiency. The ability to visualize this multiphase mixing can not only help identify poor mixing but also explain the mechanism for poor mixing. The information gained from the visualization can be used to improve the overall combustion efficiency in utility boilers or propulsion devices. We have used this technique to visualize steady-state simulations of the combustion performance in several furnace designs.

  1. Experimental variable-density mixing statistics

    NASA Astrophysics Data System (ADS)

    Gerashchenko, Sergiy; Prestridge, Katherine

    2013-11-01

    Velocity and density statistics are studied experimentally for variable density mixing of a heavy fluid jet into air coflow at two Atwood numbers. The effect of buoyancy is found to be important for most turbulent quantities measured. The high At jet with larger Reynolds number shows reduced lateral spreading compared to the low At jet of smaller Reynolds number. Some universal features of variable density mixing are elucidated from PDFs of density and density gradients. The low Atwood number PDFs show fast and uniform mixing. High Atwood number PDFs of density have skewness toward the larger densities, indicating reduced rate of mixing of pure heavy fluid due to its inertia. This skewness is related to strong local compression events that can lead to enhanced molecular mixing. Turbulent kinetic energy decreases with distance from the jet for low Atwood number but increases for high Atwood number due to flow acceleration and generation of extra shear and turbulence. This is clearly a buoyancy-mediated effect. Statistical characteristics of mixing such as Favre-averaged Reynolds stress and its anisotropy, turbulent mass flux velocity, density-specific volume correlation, density power spectra are also examined in the near and far field from the jet.

  2. Cylindrical Mixing Layer Model in Stellar Jet

    NASA Astrophysics Data System (ADS)

    Choe, Seung-Urn; Yu, Kyoung Hee

    1994-12-01

    We have developed a cylindrical mixing layer model of a stellar jet including cooling effect in order to understand an optical emission mechanism along collimated high velocity stellar jets associated with young stellar objects. The cylindrical results have been calculated to be the same as the 2D ones presented by Canto & Raga(1991) because the entrainment efficiency in our cylindrical model has been obtained to be the same value as the 2D model has given. We have discussed the morphological and physical characteristics of the mixing layers by the cooling effect. As the jet Mach number increases, the initial temperature of the mixing layer goes high because the kinetic energy of the jet partly converts to the thermal energy of the mixing layer. The initial cooling of the mixing layer is very severe, changing its outer boundary radius. A subsequent change becomes adiabatic. The number of the Mach disks in the stellar jet and the total radiative luminosity of the mixing layer, based on our cylindrical calculation, have quite agreed with the observation.

  3. What is so new about mixed methods?

    PubMed

    Pelto, Pertti J

    2015-06-01

    In this article, I dispute claims that mixed methods research emerged only recently in the social sciences. I argue that some anthropologists and sociologists (and others) have used mixed methods in fieldwork for at least 80 years, and there are studies from early in the 20th century that clearly fall within the definition of "mixed methods." I explore some of the history of the mixing of qualitative and quantitative data in earlier ethnographic works and show that in some sectors of social science research, the "emergence" and proliferation of mixed methods were particularly notable around the middle of the 20th century. Furthermore, concerning issues about "paradigms of research" in the social sciences, I identify some of the types of research in which the mixing of QUAL and QUAN approaches was more likely to occur. I suggest that some of the literature about research paradigms has involved a certain amount of "myth-making" in connection with descriptions of qualitative and quantitative research assumptions and styles. © The Author(s) 2015.

  4. Neutrino mass and mixing with discrete symmetry.

    PubMed

    King, Stephen F; Luhn, Christoph

    2013-05-01

    This is a review paper about neutrino mass and mixing and flavour model building strategies based on discrete family symmetry. After a pedagogical introduction and overview of the whole of neutrino physics, we focus on the PMNS mixing matrix and the latest global fits following the Daya Bay and RENO experiments which measure the reactor angle. We then describe the simple bimaximal, tri-bimaximal and golden ratio patterns of lepton mixing and the deviations required for a non-zero reactor angle, with solar or atmospheric mixing sum rules resulting from charged lepton corrections or residual trimaximal mixing. The different types of see-saw mechanism are then reviewed as well as the sequential dominance mechanism. We then give a mini-review of finite group theory, which may be used as a discrete family symmetry broken by flavons either completely, or with different subgroups preserved in the neutrino and charged lepton sectors. These two approaches are then reviewed in detail in separate chapters including mechanisms for flavon vacuum alignment and different model building strategies that have been proposed to generate the reactor angle. We then briefly review grand unified theories (GUTs) and how they may be combined with discrete family symmetry to describe all quark and lepton masses and mixing. Finally, we discuss three model examples which combine an SU(5) GUT with the discrete family symmetries A₄, S₄ and Δ(96).

  5. Disruption of superlattice phonons by interfacial mixing

    NASA Astrophysics Data System (ADS)

    Huberman, Samuel C.; Larkin, Jason M.; McGaughey, Alan J. H.; Amon, Cristina H.

    2013-10-01

    Molecular dynamics simulations and lattice dynamics calculations are used to study the vibrational modes and thermal transport in Lennard-Jones superlattices with perfect and mixed interfaces. The secondary periodicity of the superlattices leads to a vibrational spectrum (i.e., dispersion relation) that is distinct from the bulk spectra of the constituent materials. The mode eigenvectors of the perfect superlattices are found to be good representations of the majority of the modes in the mixed superlattices for up to 20% interfacial mixing, allowing for extraction of phonon frequencies and lifetimes. Using the frequencies and lifetimes, the in-plane and cross-plane thermal conductivities are predicted using a solution of the Boltzmann transport equation (BTE), with agreement found with predictions from the Green-Kubo method for the perfect superlattices. For the mixed superlattices, the Green-Kubo and BTE predictions agree for the cross-plane direction, where thermal conductivity is dominated by low-frequency modes whose eigenvectors are not affected by the mixing. For the in-plane direction, mid-frequency modes that contribute to thermal transport are disrupted by the mixing, leading to an underprediction of thermal conductivity by the BTE. The results highlight the importance of using a dispersion relation that includes the secondary periodicity when predicting phonon properties in perfect superlattices and emphasize the challenges of estimating the effects of disorder on phonon properties.

  6. Effects of temporal fluctuations on mixing

    NASA Astrophysics Data System (ADS)

    Pool, Maria; Dentz, Marco; Post, Vincent E. A.; Simmons, Craig T.

    2016-04-01

    Mixing and dispersion in coastal aquifers are strongly influenced by periodic temporal flow fluctuations on multiple time-scales ranging from days (tides), seasons (pumping and recharge) to glacial cycles (regression and transgressions). Transient forcing effects lead to a complex space- ant time-dependent flow response which induces enhanced spreading and mixing of a dissolved substance. We study effective mixing and solute transport in temporally fluctuating one-dimensional flow for a stable stratification of two fluids of different density. We derive explicit expressions for the concentration distribution and variance to identify the controls and obtain realistic predictions of the coupling between mixing and oscillatory transient flow. We find that the magnitude of transient-driven mixing is mainly controlled by the hydraulic diffusivity, the period and the initial interface location. We also find a spatial dependence of the effective dispersion coefficient which at long times causes the concentration profile to become asymmetric. Sand column experiments under well-controlled laboratory conditions are presented to validate the theoretical effective model defined. The proposed formulation is found to provide very good predictions and correctly reproduces the experimental mixing dynamics.

  7. Charm CP violation and mixing at Belle

    NASA Astrophysics Data System (ADS)

    Rok Ko, Byeong; Belle Collaboration

    2014-11-01

    We present charm CP violation and mixing measurements at Belle. They are the first observation of D0 - bar D0 mixing in e+e- collisions from D0 → K+π- decays, the most precise mixing and indirect CP violation parameters from D0 → K0Sπ+π- decays, and the timeintegrated CP asymmetries in D0 → π0π0 and D0 → K0Sπ0 decays. Our mixing measurement in D0 → K+π- decays excludes the no-mixing hypothesis at the 5.1 standard deviation level. The mixing parameters x = (0.56 ± 0.19+0.03+0.06-0.09-0.09)%, y = (0.30 ± 0.15+0.04+0.03-0.05-0.06)% and indirect CP violation parameters |q/p| = (0.90+0.16+0.05+0.06-0.15-0.04-0.05)%, arg(q/p) = (-6 ± 11 ± 3+3-4)° measured from D0 → K0Sπ+π- decays, and the time-integrated CP asymmetries AD0→π0π0CP = (-0.03 ± 0.64 ± 0.10)% and AD0→K0Sπ0CP = (-0.21 ± 0.16 ± 0.07)% are the most precisemeasurements to date. Our measurements here are consistent with predictions of the standard model.

  8. LED color mixing with diffractive structures

    NASA Astrophysics Data System (ADS)

    Bonenberger, Theresa; Baumgart, Jörg; Wendel, Simon; Neumann, Cornelius

    2013-03-01

    Lighting solutions with colored LEDs provide many opportunities for illumination. One of these opportunities is to create a color tunable light source. In this way different kinds of white light (color temperature) as well as discrete colors may be realized. This opens the field for applications as mood lighting. But there is always a spatial separation of the distinct LEDs that might get converted into an angular separation by any collimating optics. This angular separation causes such problems like color fringes and colored shadows that cannot be accepted in most applications. Conventional methods to solve these problems include e.g. mixing rods or dichroic filters. A new approach is the use of the dispersive effect of a diffractive structure to compensate the angular separation of the different colors. In this contribution the potential and limitations of diffractive structures in LED color mixing applications are discussed. Ray tracing simulations were performed to analyze such important parameters like efficiency, color performance and the cross section of the color mixing optics. New means for the estimation of color mixing performance were developed. A software tool makes it possible to detect the color distribution within ray trace data and it provides a quality factor to estimate the color mixing performance. It can be shown that the spectral band width has a large influence on the mixing process. Ray tracing simulations are compared with results of an experimental setup such that both measured as well as simulated data is presented.

  9. Ion beam mixing by focused ion beam

    NASA Astrophysics Data System (ADS)

    Barna, Árpád; Kotis, László; Lábár, János L.; Osváth, Zoltán; Tóth, Attila L.; Menyhárd, Miklós; Zalar, Anton; Panjan, Peter

    2007-09-01

    Si amorphous (41 nm)/Cr polycrystalline (46 nm) multilayer structure was irradiated by 30 keV Ga+ ions with fluences in the range of 25-820 ions/nm2 using a focused ion beam. The effect of irradiation on the concentration distribution was studied by Auger electron spectroscopy depth profiling, cross-sectional transmission electron microscopy, and atomic force microscopy. The ion irradiation did not result in roughening on the free surface. On the other hand, the Ga+ irradiation produced a strongly mixed region around the first Si/Cr interface. The thickness of mixed region depends on the Ga+ fluence and it is joined to the pure Cr matrix with an unusual sharp interface. With increasing fluence the width of the mixed region increases but the interface between the mixed layer and pure Cr remains sharp. TRIDYN simulation failed to reproduce this behavior. Assuming that the Ga+ irradiation induces asymmetric mixing, that is during the mixing process the Cr can enter the Si layer, but the Si cannot enter the Cr layer, the experimental findings can qualitatively be explained.

  10. An Argo mixed layer climatology and database

    NASA Astrophysics Data System (ADS)

    Holte, James; Talley, Lynne D.; Gilson, John; Roemmich, Dean

    2017-06-01

    A global climatology and database of mixed layer properties are computed from nearly 1,250,000 Argo profiles. The climatology is calculated with both a hybrid algorithm for detecting the mixed layer depth (MLD) and a standard threshold method. The climatology provides accurate information about the depth, properties, extent, and seasonal patterns of global mixed layers. The individual profile results in the database can be used to construct time series of mixed layer properties in specific regions of interest. The climatology and database are available online at http://mixedlayer.ucsd.edu. The MLDs calculated by the hybrid algorithm are shallower and generally more accurate than those of the threshold method, particularly in regions of deep winter mixed layers; the new climatology differs the most from existing mixed layer climatologies in these regions. Examples are presented from the Labrador and Irminger Seas, the Southern Ocean, and the North Atlantic Ocean near the Gulf Stream. In these regions the threshold method tends to overestimate winter MLDs by approximately 10% compared to the algorithm.

  11. Using Multimedia Records To Support Mixed-Method Evaluation.

    ERIC Educational Resources Information Center

    Bennington, Tammy L.; Jones, Michael L. W.; Gay, Geri

    1999-01-01

    Explores how multimedia records, especially digital video, can enhance the analysis and presentation of research findings and can facilitate mixed-method research designs. Draws analogies between mixing methods and mixing technologies. (Author/SLD)

  12. Tribimaximal mixing, discrete family symmetries, and a conjecture connecting the quark and lepton mixing matrices

    NASA Astrophysics Data System (ADS)

    Low, Catherine I.; Volkas, Raymond R.

    2003-08-01

    Neutrino oscillation experiments (excluding the Liquid Scintillator Neutrino Detector experiment) suggest a tribimaximal form for the lepton mixing matrix. This form indicates that the mixing matrix is probably independent of the lepton masses, and suggests the action of an underlying discrete family symmetry. Using these hints, we conjecture that the contrasting forms of the quark and lepton mixing matrices may both be generated by such a discrete family symmetry. This idea is that the diagonalization matrices out of which the physical mixing matrices are composed have large mixing angles, which cancel out due to a symmetry when the CKM matrix is computed, but do not do so in the MNS case. However, in the cases where the Higgs bosons are singlets under the symmetry, and the family symmetry commutes with SU(2)L, we prove a no-go theorem: no discrete unbroken family symmetry can produce the required mixing patterns. We then suggest avenues for future research.

  13. Martian Mixed Layer during Pathfinder Mission

    NASA Astrophysics Data System (ADS)

    Martinez, G. M.; Valero, F.; Vazquez, L.

    2008-09-01

    In situ measurements of the Martian Planetary Boundary Layer (MPBL) encompass only the sur- face layer. Therefore, in order to fully address the MPBL, it becomes necessary to simulate somehow the behaviour of the martian mixed layer. The small-scale processes that happen in the MPBL cause GCM's ([1], [2]) to describe only partially the turbulent statistics, height, convective scales, etc, of the surface layer and the mixed layer. For this reason, 2D and 3D martian mesoscale models ([4], [5]), and large eddy simulations ([4], [6], [7], [8]) have been designed in the last years. Although they are expected to simulate more accurately the MPBL, they take an extremely expensive compu- tational time. Alternatively, we have derived the main turbu- lent characteristics of the martian mixed layer by using surface layer and mixed layer similarity ([9], [10]). From in situ temperature and wind speed measurements, together with quality-tested simu- lated ground temperature [11], we have character- ized the martian mixed layer during the convective hours of Pathfinder mission Sol 25. Mean mixed layer turbulent statistics like tem- perature variance < σ? >, horizontal wind speed variance < σu,v >, vertical wind speed variance < σw >, viscous dissipation rate < ǫ >, and turbu- lent kinetic energy < e > have been calculated, as well as the mixed layer height zi, and the convective scales of wind w? and temperature θ?. Our values, obtained with negligible time cost, match quite well with some previously obtained results via LES's ([4] and [8]). A comparisson between the above obtained mar- tian values and the typical Earth values are shown in Table 1. Convective velocity scale w doubles its counterpart terrestrial typical value, as it does the mean wind speed variances < σu,v > and < σw >. On the other hand, the temperature scale θ? and the mean temperature variance < σ > are virtually around one order higher on Mars. The limitations of these results concern the va- lidity

  14. Quantifying mixing using magnetic resonance imaging.

    PubMed

    Tozzi, Emilio J; McCarthy, Kathryn L; Bacca, Lori A; Hartt, William H; McCarthy, Michael J

    2012-01-25

    Mixing is a unit operation that combines two or more components into a homogeneous mixture. This work involves mixing two viscous liquid streams using an in-line static mixer. The mixer is a split-and-recombine design that employs shear and extensional flow to increase the interfacial contact between the components. A prototype split-and-recombine (SAR) mixer was constructed by aligning a series of thin laser-cut Poly (methyl methacrylate) (PMMA) plates held in place in a PVC pipe. Mixing in this device is illustrated in the photograph in Fig. 1. Red dye was added to a portion of the test fluid and used as the minor component being mixed into the major (undyed) component. At the inlet of the mixer, the injected layer of tracer fluid is split into two layers as it flows through the mixing section. On each subsequent mixing section, the number of horizontal layers is duplicated. Ultimately, the single stream of dye is uniformly dispersed throughout the cross section of the device. Using a non-Newtonian test fluid of 0.2% Carbopol and a doped tracer fluid of similar composition, mixing in the unit is visualized using magnetic resonance imaging (MRI). MRI is a very powerful experimental probe of molecular chemical and physical environment as well as sample structure on the length scales from microns to centimeters. This sensitivity has resulted in broad application of these techniques to characterize physical, chemical and/or biological properties of materials ranging from humans to foods to porous media (1, 2). The equipment and conditions used here are suitable for imaging liquids containing substantial amounts of NMR mobile (1)H such as ordinary water and organic liquids including oils. Traditionally MRI has utilized super conducting magnets which are not suitable for industrial environments and not portable within a laboratory (Fig. 2). Recent advances in magnet technology have permitted the construction of large volume industrially compatible magnets suitable for

  15. Quantifying Mixing using Magnetic Resonance Imaging

    PubMed Central

    Tozzi, Emilio J.; McCarthy, Kathryn L.; Bacca, Lori A.; Hartt, William H.; McCarthy, Michael J.

    2012-01-01

    Mixing is a unit operation that combines two or more components into a homogeneous mixture. This work involves mixing two viscous liquid streams using an in-line static mixer. The mixer is a split-and-recombine design that employs shear and extensional flow to increase the interfacial contact between the components. A prototype split-and-recombine (SAR) mixer was constructed by aligning a series of thin laser-cut Poly (methyl methacrylate) (PMMA) plates held in place in a PVC pipe. Mixing in this device is illustrated in the photograph in Fig. 1. Red dye was added to a portion of the test fluid and used as the minor component being mixed into the major (undyed) component. At the inlet of the mixer, the injected layer of tracer fluid is split into two layers as it flows through the mixing section. On each subsequent mixing section, the number of horizontal layers is duplicated. Ultimately, the single stream of dye is uniformly dispersed throughout the cross section of the device. Using a non-Newtonian test fluid of 0.2% Carbopol and a doped tracer fluid of similar composition, mixing in the unit is visualized using magnetic resonance imaging (MRI). MRI is a very powerful experimental probe of molecular chemical and physical environment as well as sample structure on the length scales from microns to centimeters. This sensitivity has resulted in broad application of these techniques to characterize physical, chemical and/or biological properties of materials ranging from humans to foods to porous media 1, 2. The equipment and conditions used here are suitable for imaging liquids containing substantial amounts of NMR mobile 1H such as ordinary water and organic liquids including oils. Traditionally MRI has utilized super conducting magnets which are not suitable for industrial environments and not portable within a laboratory (Fig. 2). Recent advances in magnet technology have permitted the construction of large volume industrially compatible magnets suitable for

  16. Measurements of Molecular Mixing in a High Schmidt Number Rayleigh-Taylor Mixing Layer

    SciTech Connect

    Mueschke, N J; Schilling, O; Youngs, D L; Andrews, M

    2007-12-03

    Molecular mixing measurements are performed for a high Schmidt number (Sc {approx} 10{sup 3}), small Atwood number (A {approx} 7.5 x 10{sup -4}) buoyancy-driven turbulent Rayleigh-Taylor mixing layer in a water channel facility. Salt was added to the top stream to create the desired density difference. The degree of molecular mixing was measured as a function of time by monitoring a diffusion-limited chemical reaction between the two fluid streams. The pH of each stream was modified by the addition of acid or alkali such that a local neutralization reaction occurred as the two fluids molecularly mixed. The progress of this neutralization reaction was tracked by the addition of phenolphthalein - a pH-sensitive chemical indicator - to the acidic stream. Accurately calibrated backlit optical techniques were used to measure the average concentration of the colored chemical indicator. Comparisons of chemical product formation for pre-transitional buoyancy- and shear-driven mixing layers are given. It is also shown that experiments performed at different equivalence ratios (acid/alkali concentration) can be combined to obtain a mathematical relationship between the colored product formed and the density variance. This relationship was used to obtain high-fidelity, quantitative measures of the degree of molecular mixing which are independent of probe resolution constraints. The dependence of such mixing parameters on the Schmidt and Reynolds numbers is examined by comparing the current Sc {approx} 10{sup 3} measurements with Sc = 0.7 gas-phase and Pr = 7 liquid-phase measurements. This comparison indicates that the Schmidt number has a large effect on the bulk quantity of mixed fluid at small Reynolds numbers Re{sub h} < 10{sup 3}. At late times, all mixing parameters indicated a greater degree of molecular mixing and a decreased Schmidt number dependence. Implications for the development and quantitative assessment of turbulent transport and mixing models appropriate for

  17. Application of the Fokker-Planck molecular mixing model to turbulent scalar mixing using moment methods

    NASA Astrophysics Data System (ADS)

    Madadi-Kandjani, E.; Fox, R. O.; Passalacqua, A.

    2017-06-01

    An extended quadrature method of moments using the β kernel density function (β -EQMOM) is used to approximate solutions to the evolution equation for univariate and bivariate composition probability distribution functions (PDFs) of a passive scalar for binary and ternary mixing. The key element of interest is the molecular mixing term, which is described using the Fokker-Planck (FP) molecular mixing model. The direct numerical simulations (DNSs) of Eswaran and Pope ["Direct numerical simulations of the turbulent mixing of a passive scalar," Phys. Fluids 31, 506 (1988)] and the amplitude mapping closure (AMC) of Pope ["Mapping closures for turbulent mixing and reaction," Theor. Comput. Fluid Dyn. 2, 255 (1991)] are taken as reference solutions to establish the accuracy of the FP model in the case of binary mixing. The DNSs of Juneja and Pope ["A DNS study of turbulent mixing of two passive scalars," Phys. Fluids 8, 2161 (1996)] are used to validate the results obtained for ternary mixing. Simulations are performed with both the conditional scalar dissipation rate (CSDR) proposed by Fox [Computational Methods for Turbulent Reacting Flows (Cambridge University Press, 2003)] and the CSDR from AMC, with the scalar dissipation rate provided as input and obtained from the DNS. Using scalar moments up to fourth order, the ability of the FP model to capture the evolution of the shape of the PDF, important in turbulent mixing problems, is demonstrated. Compared to the widely used assumed β -PDF model [S. S. Girimaji, "Assumed β-pdf model for turbulent mixing: Validation and extension to multiple scalar mixing," Combust. Sci. Technol. 78, 177 (1991)], the β -EQMOM solution to the FP model more accurately describes the initial mixing process with a relatively small increase in computational cost.

  18. Scalable Lateral Mixing and Coherent Turbulence DRI: Use of an AUV to Quantify Submesoscale Mixing Processes

    DTIC Science & Technology

    2012-09-30

    of an AUV to Quantify Submesoscale Mixing Processes Louis Goodman School for Marine Science and Technology (SMAST) University of Massachusetts...role of ocean turbulence in submesoscale dynamics. OBJECTIVES The objective of this project is to examine the role of ocean turbulence in... submesoscale mixing observed during the June 2011 LatMix experiment. Key questions to be addressed are the following: (1) What are the space and

  19. Liquid–liquid mixing studies in annular centrifugal contactors comparing stationary mixing vane options

    SciTech Connect

    Wardle, Kent E.

    2015-09-11

    Comparative studies of multiphase operation of an annular centrifugal contactor show the impact of housing stationary mixing vane configuration. A number of experimental results for several different mixing vane options are reported for operation of a 12.5 cm engineering-scale contactor unit. Fewer straight vanes give greater mixing-zone hold-up compared to curved vanes. Quantitative comparison of droplet size distribution also showed a significant decrease in mean diameter for four straight vanes versus eight curved vanes. This set of measurements gives a compelling case for careful consideration of mixing vane geometry when evaluating hydraulic operation and extraction process efficiency of annular centrifugal contactors.

  20. Development of a simplified asphalt mix stability procedure for use in Superpave volumetric mix design

    NASA Astrophysics Data System (ADS)

    Hafez, Ihab Hussein Fahmy

    Over the last five decades, two common test methods (Marshall and Hveem) have evolved for the design of asphaltic mixes. These design methods have been historically found to be generally reliable and reasonable for most application in design. However, premature distress in many flexible pavements suggests that these empirical methods of design do not guarantee a stable mix. Recently, many studies have been carried out in order to develop a rational mix design procedure that accounts for both the mix volumetric properties as well as fundamental engineering properties. Among those is the Superpave design procedure, which was originally divided into three, hierarchical levels termed the volumetric mix design (level I), the abbreviated mix design (level II), and the full mix design (level III). In the volumetric design, the entire mix design process is based upon the volumetric properties and does not include a test method to evaluate the stability/strength of the mix. Although both the abbreviated level and the full level of design included test methods that considered the engineering properties in a complete and a comprehensive manner; they required the purchase of very expensive equipment and a large number of samples to be tested. The objective of this research was to develop a new rational "fundamental" mix strength (stability) test for the design of dense graded mixes to overcome the limitations of the Hveem and Marshall empirical methods and to fill the gaps and major deficiencies in the current Superpave volumetric mix design. The new procedure is based upon the Superpave volumetric design (level I) but is augmented by the simple, but fundamental mix strength (stability) test. Such a test is now currently absent in the existing Superpave approach. The new procedure introduces the flow time as a fundamental engineering design criterion in the mix design. This parameter is defined as the time (in seconds) at which plastic flow in a mix occurs under creep loading

  1. Turbulent mixing in a precessing sphere

    SciTech Connect

    Goto, Susumu Shimizu, Masaki; Kawahara, Genta

    2014-11-15

    By numerically simulating turbulent flows at high Reynolds numbers in a precessing sphere, we propose a method to enhance the mixing of a fluid confined within a smooth cavity by its rotational motion alone. To precisely evaluate the mixing efficiency, we extend the quantification method proposed by Danckwerts [“The definition and measurement of some characteristics of mixtures,” Appl. Sci. Res. A 3, 279–296 (1952)] to the case in which only a finite number of fluid particle trajectories can be known. Our accurate numerical tracking of fluid particles in the flow, which is controlled by the Reynolds number (an indicator of the spin rate) and the Poincaré number (the precession rate), shows the following results. First, the mixing process on the time scale normalized by the spin period is independent of the Reynolds number as long as it is high enough for the flow to be developed turbulence. Second, fastest mixing is achieved under weak precession (Poincaré number ≈0.1); in such cases, perfect mixing requires only 10–15 spins of the container. Third, the power to sustain turbulence is a weakly increasing function of the Poincaré number, and the energy efficiency of the mixing is also maximized when the Poincaré number is about 0.1. Fourth, efficient mixing driven by the weak precession arises from the effective cooperation of complex large-scale flow and small-scale turbulence, which itself is sustained by the large-scale flow.

  2. Mixing, segregation, and flow of granular materials

    NASA Astrophysics Data System (ADS)

    McCarthy, Joseph J.

    1998-11-01

    This dissertation addresses mixing, segregation, and flow of granular materials with the ultimate goal of providing fundamental understanding and tools for the rational design and optimization of mixing devices. In particular, the paradigm cases of a slowly rotated tumbler mixer and flow down an inclined plane are examined. Computational work, as well as supporting experiments, are used to probe both two and three dimensional systems. In the avalanching regime, the mixing and flow can be viewed either on a global-scale or a local-scale. On the global-scale, material is transported via avalanches whose gross motion can be well described by geometrical considerations. On the local-scale, the dynamics of the particle motion becomes important; particles follow complicated trajectories that are highly sensitive to differences in size/density/morphology. By decomposing the problem in this way, it is possible to study the implications of the geometry and dynamics separately and to add complexities in a controlled fashion. This methodology allows even seemingly difficult problems (i.e., mixing in non-convex geometries, and mixing of dissimilar particles) to be probed in a simple yet methodical way. In addition this technique provides predictions of optimal mixing conditions in an avalanching tumbler, a criterion for evaluating the effect of mixer shape, and mixing enhancement strategies for both two and three dimensional mixers. In the continuous regime, the flow can be divided into two regions: a rapid flow region of the cascading layer at the free surface, and a fixed bed region undergoing solid body rotation. A continuum-based description, in which averages are taken across the layer, generates quantitative predictions about the flow in the cascading layer and agrees well with experiment. Incorporating mixing through a diffusive flux (as well as constitutive expression for segregation) within the cascading layer allows for the determination of optimal mixing conditions

  3. Theoretical analysis of mixing in liquid clouds - Part 3: Inhomogeneous mixing

    NASA Astrophysics Data System (ADS)

    Pinsky, Mark; Khain, Alexander; Korolev, Alexei

    2016-07-01

    An idealized diffusion-evaporation model of time-dependent mixing between a cloud volume and a droplet-free volume is analyzed. The initial droplet size distribution (DSD) in the cloud volume is assumed to be monodisperse. It is shown that evolution of the microphysical variables and the final equilibrium state are unambiguously determined by two non-dimensional parameters. The first one is the potential evaporation parameter R, proportional to the ratio of the saturation deficit to the liquid water content in the cloud volume, that determines whether the equilibrium state is reached at 100 % relative humidity, or is characterized by a complete evaporation of cloud droplets. The second parameter Da is the Damkölher number equal to the ratio of the characteristic mixing time to the phase relaxation time. Parameters R and Da determine the type of mixing.The results are analyzed within a wide range of values of R and Da. It is shown that there is no pure homogeneous mixing, since the first mixing stage is always inhomogeneous. The mixing type can change during the mixing process. Any mixing type leads to formation of a tail of small droplets in DSD and, therefore, to DSD broadening that depends on Da. At large Da, the final DSD dispersion can be as large as 0.2. The total duration of mixing varies from several to 100 phase relaxation time periods, depending on R and Da.The definitions of homogeneous and inhomogeneous types of mixing are reconsidered and clarified, enabling a more precise delimitation between them. The paper also compares the results obtained with those based on the classic mixing concepts. >

  4. Flavor mixing democracy and minimal CP violation

    NASA Astrophysics Data System (ADS)

    Gerard, Jean-Marc; Xing, Zhi-zhong

    2012-06-01

    We point out that there is a unique parametrization of quark flavor mixing in which every angle is close to the Cabibbo angle θC≃13° with the CP-violating phase ϕq around 1°, implying that they might all be related to the strong hierarchy among quark masses. Applying the same parametrization to lepton flavor mixing, we find that all three mixing angles are comparably large (around π/4) and the Dirac CP-violating phase ϕl is also minimal as compared with its values in the other eight possible parametrizations. In this spirit, we propose a simple neutrino mixing ansatz which is equivalent to the tri-bimaximal flavor mixing pattern in the ϕl→0 limit and predicts sin θ13=1/√{2}sin(ϕl/2) for reactor antineutrino oscillations. Hence the Jarlskog invariant of leptonic CP violation Jl=(sin ϕl)/12 can reach a few percent if θ13 lies in the range 7°⩽θ13⩽10°.

  5. Mixing Dynamics Between Water and Biofuels

    NASA Astrophysics Data System (ADS)

    Cotel, Aline; Demond, Avery; Lei, Jiariu; Green, Erica

    2013-11-01

    Currently, ethanol-based biofuels are considered to be among the best alternatives to gasoline. However, the potential environmental impact of a spill of such fuels on aquatic environments is an area of open discussion and research. Since these fuels are a combination of a miscible fluid (ethanol) and an immiscible fluid (gasoline), models used for traditional gasoline fuels (immiscible in water) are not applicable. Preliminary experiments show that when a solution of ethanol and glycol is mixed with water, a third mixed fluid is formed. Two distinct mixing regimes are observed. A turbulent wake is created between the ethanol/glycol and water layers to cause the ethanol and glycol solution to entrain and mix into with the water phase. In the first regime, due to nonlinear mixing behavior, a dramatic overturning is possible for a certain range of parameters. The second regime begins when the turbulent wake has dissipated and the internal wave created by the plate has begun to settle, typically within the first minute. At this point, Bénard-like cells, similar to those typically seen in Rayleigh-Bénard convection, form at the interface and relatively slow mass transfer is evident. Both regimes are described quantitatively with a set of dimensionless parameters.

  6. Mixed-species aggregations in arthropods.

    PubMed

    Boulay, Julien; Aubernon, Cindy; Ruxton, Graeme D; Hédouin, Valéry; Deneubourg, Jean-Louis; Charabidzé, Damien

    2017-06-28

    This review offers the first synthesis of the research on mixed-species groupings of arthropods and highlights the behavioural and evolutionary questions raised by such behaviour. Mixed-species groups are commonly found in mammals and birds. Such groups are also observed in a large range of arthropod taxa independent of their level of sociality. Several examples are presented to highlight the mechanisms underlying such groupings, particularly the evidence for phylogenetic proximity between members that promotes cross-species recognition. The advantages offered by such aggregates are described and discussed. These advantages can be attributed to the increase in group size and could be identical to those of non-mixed groupings, but competition-cooperation dynamics might also be involved, and such effects may differ between homo- and heterospecific groups. We discuss three extreme cases of interspecific recognition that are likely involved in mixed-species groups as vectors for cross-species aggregation: tolerance behaviour between two social species, one-way mechanism in which one species is attractive to others and two-way mechanism of mutual attraction. As shown in this review, the study of mixed-species groups offers biologists an interesting way to explore the frontiers of cooperation-competition, including the process of sympatric speciation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Who Moves to Mixed-Income Neighborhoods?*

    PubMed Central

    McKinnish, Terra; White, T. Kirk

    2011-01-01

    This paper uses confidential Census data, specifically the 1990 and 2000 Census Long Form data, to study the income dispersion of recent cohorts of migrants to mixed-income neighborhoods. We investigate whether neighborhoods with high levels of income dispersion attract economically diverse in-migrants. If recent in-migrants to mixed-income neighborhoods exhibit high levels of income dispersion, this is consistent with stable mixed-income neighborhoods. If, however, mixed-income neighborhoods are comprised of homogenous low-income (high-income) cohorts of long-term residents combined with homogenous high-income (low-income) cohorts of recent arrivals, this is consistent with neighborhood transition. Our results indicate that neighborhoods with high levels of income dispersion do in fact attract a much more heterogeneous set of in-migrants, particularly from the tails of the income distribution. Our results also suggest that the residents of mixed-income neighborhoods may be less heterogeneous with respect to lifetime income. PMID:21479114

  8. Mixing Enhancement in a Lobed Injector

    NASA Technical Reports Server (NTRS)

    Smith, L. L.; Majamaki, A. J.; Lam, I. T.; Delabroy, O.; Karagozian, A. R.; Marble, F. E.; Smith, O. I.

    1997-01-01

    An experimental investigation of the non-reactive mixing processes associated with a lobed fuel injector in a coflowing air stream is presented. The lobed fuel injector is a device which generates streamwise vorticity, producing high strain rates which can enhance the mixing of reactants while delaying ignition in a controlled manner. The lobed injectors examined in the present study consist of two corrugated plates between which a fuel surrogate, CO2, is injected into coflowing air. Acetone is seeded in the CO2 supply as a fuel marker. Comparison of two alternative lobed injector geometries is made with a straight fuel injector to determine net differences in mixing and strain fields due to streamwise vorticity generation. Planar laser-induced fluorescence (PLIF) of the seeded acetone yields two-dimensional images of the scalar concentration field at various downstream locations, from which local mixing and scalar dissipation rates are computed. It is found that the lobed injector geometry can enhance molecular mixing and create a highly strained flowfield, and that the strain rates generated by scalar energy dissipation can potentially delay ignition in a reacting flowfield.

  9. Entropy and Mixing : Titan's Humidity Revisited

    NASA Astrophysics Data System (ADS)

    Lorenz, R. D.

    2003-05-01

    Determinations of the relative humidity of methane near Titan's surface range from 40-60 %. The rationale advanced by Lunine in the global ocean hypothesis was that a mixed ethane-methane ocean in thermodynamic equilibrium with the atmosphere would be unsaturated due to methane vapor pressure supression by involatile ethane (much as salt or sugar dissolved in water slows its evaporation). Here I explore a nonequilibrium explanation for the incomplete saturation - the reason why the terrestrial atmosphere is not saturated. Specifically, saturated near-surface air is mixed with downwelling dry air, a mixing driven by vertical convection. The more vigorous the mixing, the dryer the near-surface air should be. Flasar (1983) made a crude empirical evaluation of transport processes : here I adopt a more fundamental thermodynamic approach. In reality both the involatile solute and the mixing mechanisms probably play a part in regulating methane humidity, and the utility of global and annual averages must be compromised by latitudinal and seasonal dependences. Comparison with the Earth - where moist processes play a dominant role in the entropy budget - will be instructive.

  10. Soil mixing of stratified contaminated sands.

    PubMed

    Al-Tabba, A; Ayotamuno, M J; Martin, R J

    2000-02-01

    Validation of soil mixing for the treatment of contaminated ground is needed in a wide range of site conditions to widen the application of the technology and to understand the mechanisms involved. Since very limited work has been carried out in heterogeneous ground conditions, this paper investigates the effectiveness of soil mixing in stratified sands using laboratory-scale augers. This enabled a low cost investigation of factors such as grout type and form, auger design, installation procedure, mixing mode, curing period, thickness of soil layers and natural moisture content on the unconfined compressive strength, leachability and leachate pH of the soil-grout mixes. The results showed that the auger design plays a very important part in the mixing process in heterogeneous sands. The variability of the properties measured in the stratified soils and the measurable variations caused by the various factors considered, highlighted the importance of duplicating appropriate in situ conditions, the usefulness of laboratory-scale modelling of in situ conditions and the importance of modelling soil and contaminant heterogeneities at the treatability study stage.

  11. TRENDS IN ESTIMATED MIXING DEPTH DAILY MAXIMUMS

    SciTech Connect

    Buckley, R; Amy DuPont, A; Robert Kurzeja, R; Matt Parker, M

    2007-11-12

    Mixing depth is an important quantity in the determination of air pollution concentrations. Fireweather forecasts depend strongly on estimates of the mixing depth as a means of determining the altitude and dilution (ventilation rates) of smoke plumes. The Savannah River United States Forest Service (USFS) routinely conducts prescribed fires at the Savannah River Site (SRS), a heavily wooded Department of Energy (DOE) facility located in southwest South Carolina. For many years, the Savannah River National Laboratory (SRNL) has provided forecasts of weather conditions in support of the fire program, including an estimated mixing depth using potential temperature and turbulence change with height at a given location. This paper examines trends in the average estimated mixing depth daily maximum at the SRS over an extended period of time (4.75 years) derived from numerical atmospheric simulations using two versions of the Regional Atmospheric Modeling System (RAMS). This allows for differences to be seen between the model versions, as well as trends on a multi-year time frame. In addition, comparisons of predicted mixing depth for individual days in which special balloon soundings were released are also discussed.

  12. Dynamical systems techniques for enhancing microfluidic mixing

    NASA Astrophysics Data System (ADS)

    Balasuriya, Sanjeeva

    2015-09-01

    Achieving rapid mixing is often desirable in microfluidic devices, for example in improving reation rates in biotechnological assays. Enhancing mixing within a particular context is often achieved by introducing problem-specific strategies such as grooved or twisted channels, ac electromagnetic fields or oscillatory microsyringe flows. Evaluating the efficiency of these methods is challenging since either experimental fabrication and sensing, or computationally expensive direct numerical simulations with complicated boundary conditions, are required. A review of how mixing can be quantified when velocity fields have been obtained from such situations is presented. A less-known alternative to these methods is offered by dynamical systems, which characterizes the motion of collective fluid parcel trajectories by studying crucial interior flow barriers which move unsteadily, but nevertheless strongly govern mixing possibilities. The methodology behind defining these barriers and quantifying the fluid transport influenced by them is explained. Their application towards several microfluidic situations (e.g. best cross-flow positioning in cross-channel micromixers, usage of channel curvature to enhance mixing within microdroplets traveling in a channel, optimum frequencies of velocity agitations to use) is discussed.

  13. Mixed gaits in small avian terrestrial locomotion

    PubMed Central

    Andrada, Emanuel; Haase, Daniel; Sutedja, Yefta; Nyakatura, John A.; M. Kilbourne, Brandon; Denzler, Joachim; Fischer, Martin S.; Blickhan, Reinhard

    2015-01-01

    Scientists have historically categorized gaits discretely (e.g. regular gaits such as walking, running). However, previous results suggest that animals such as birds might mix or regularly or stochastically switch between gaits while maintaining a steady locomotor speed. Here, we combined a novel and completely automated large-scale study (over one million frames) on motions of the center of mass in several bird species (quail, oystercatcher, northern lapwing, pigeon, and avocet) with numerical simulations. The birds studied do not strictly prefer walking mechanics at lower speeds or running mechanics at higher speeds. Moreover, our results clearly display that the birds in our study employ mixed gaits (such as one step walking followed by one step using running mechanics) more often than walking and, surprisingly, maybe as often as grounded running. Using a bio-inspired model based on parameters obtained from real quails, we found two types of stable mixed gaits. In the first, both legs exhibit different gait mechanics, whereas in the second, legs gradually alternate from one gait mechanics into the other. Interestingly, mixed gaits parameters mostly overlap those of grounded running. Thus, perturbations or changes in the state induce a switch from grounded running to mixed gaits or vice versa. PMID:26333477

  14. Anomalous Alloy Properties in Mixed Halide Perovskites.

    PubMed

    Yin, Wan-Jian; Yan, Yanfa; Wei, Su-Huai

    2014-11-06

    Engineering halide perovskite through mixing halogen elements, such as CH3NH3PbI3-xClx and CH3NH3PbI3-xBrx, is a viable way to tune its electronic and optical properties. Despite many emerging experiments on mixed halide perovskites, the basic electronic and structural properties of the alloys have not been understood and some crucial questions remain, for example, how much Cl can be incorporated into CH3NH3PbI3 is still unclear. In this Letter, we chose CsPbX3 (X = I, Br, Cl) as an example and use a first-principle calculation together with cluster-expansion methods to systematically study the structural, electronic, and optical properties of mixed halide perovskites and find that unlike conventional semiconductor alloys, they exhibit many anomalous alloy properties such as small or even negative formation energies at some concentrations and negligible or even negative band gap bowing parameters at high temperature. We further show that mixed-(I,Cl) perovskite is hard to form at temperature below 625 K, whereas forming mixed-(Br,Cl) and (I,Br) alloys are easy at room temperature.

  15. Mixed gaits in small avian terrestrial locomotion.

    PubMed

    Andrada, Emanuel; Haase, Daniel; Sutedja, Yefta; Nyakatura, John A; Kilbourne, Brandon M; Denzler, Joachim; Fischer, Martin S; Blickhan, Reinhard

    2015-09-03

    Scientists have historically categorized gaits discretely (e.g. regular gaits such as walking, running). However, previous results suggest that animals such as birds might mix or regularly or stochastically switch between gaits while maintaining a steady locomotor speed. Here, we combined a novel and completely automated large-scale study (over one million frames) on motions of the center of mass in several bird species (quail, oystercatcher, northern lapwing, pigeon, and avocet) with numerical simulations. The birds studied do not strictly prefer walking mechanics at lower speeds or running mechanics at higher speeds. Moreover, our results clearly display that the birds in our study employ mixed gaits (such as one step walking followed by one step using running mechanics) more often than walking and, surprisingly, maybe as often as grounded running. Using a bio-inspired model based on parameters obtained from real quails, we found two types of stable mixed gaits. In the first, both legs exhibit different gait mechanics, whereas in the second, legs gradually alternate from one gait mechanics into the other. Interestingly, mixed gaits parameters mostly overlap those of grounded running. Thus, perturbations or changes in the state induce a switch from grounded running to mixed gaits or vice versa.

  16. Mixing in suspensions of active particles

    NASA Astrophysics Data System (ADS)

    Pushkin, Dmitri O.; Yeomans, Julia M.

    2014-03-01

    Microscopic active particles self-propelling in the surrounding fluid create flows that eventually lead to emergence of non-equilibrium states with long-ranged fluctuations. One of the technologically important consequences of these fluctuations is enhanced mixing of the surrounding fluid. It is also critical for understanding the ecology of a particular type of biological active systems, bacterial suspension, as the enhanced mixing strongly alters the fluxes of nutrients. We consider the theoretical foundations of fluid mixing enhancement in dilute suspensions of active force-free swimmers. We describe the impediments to fluid mixing imposed by the physical nature of fluid flows created by swimmers, and different ways of overcoming them. We show that fluid mixing in 3D suspensions of force-free (dipolar) swimmers is dominated by the effect of curvature of their trajectories, and obtain an exact analytical expression for the corresponding effective diffusion coefficient. Our results highlight limitations of alternative ``effective temperature'' approaches and may serve as a quantitative tool for designing technological applications.

  17. Diapycnal mixing in an Arctic coastal polynya

    NASA Astrophysics Data System (ADS)

    Bouruet-Aubertot, P.; Jardon, F.; Vivier, F.; Lourenço, A.; Cuypers, Y.

    2009-12-01

    Ocean mixing plays an important role in climate variability. In Arctic coastal polynyas, which are regions of dense water formation, internal wave activity and turbulent mixing can affect the ice cover through induced ocean-ice heat flux. Mixing can also affect the fate of dense waters once formed. In March 2007, a 60m-long ice tethered mooring, recording temperature and salinity at high frequency, with a relatively fine vertical resolution was deployed in the western part of Storfjorden in the Svalbard archipelago. Estimates of turbulent dissipation rates were derived from isopycnal vertical displacements. Eddy diffusivity was next inferred using a parameterization that depends on the energetics of the stratified turbulent flow. Observed levels of dissipation of turbulent potential energy per unit mass, 1.82 x 10e-7 W/kg, and diapycnal diffusivity, 2.8 x 10e-4 m2/s, were consistent with previous direct measurements in the region. The maximum values were found under the ice-ocean interface and down to 35m with a relative minimum in between, suggesting two differents energy source. As the ice cap limits mixing by the winds, internal ocean dynamics becomes a prominent source of mixing, especially in coastal regions. The influence of tides as a possible energy source for the internal wave field was therefore investigated. Finally, the internal wave field is compared with those at mid-latitudes and reasonable agreement with the Garret-Munk model is found.

  18. Flow and mixing by small intestine villi.

    PubMed

    Lim, Y F; de Loubens, C; Love, R J; Lentle, R G; Janssen, P W M

    2015-06-01

    Flow and mixing in the small intestine are multi-scale processes. Flows at the scale of the villi (finger-like structures of ≈500 μm length) are poorly understood. We developed a three-dimensional lattice-Boltzmann model to gain insight into the effects of villous movements and the rheology of digesta on flow, mixing and absorption of nutrients at the periphery of the intestinal lumen. Our model simulated the hydrodynamic consequences of villi movements that resulted from folding of the mucosa during longitudinal contractions. We found that cyclic approximation and separation of groups of villi generated laminar eddies at the edges of the group and augmented mass transfers in the radial direction between the inter-villous space and the intestinal lumen which improved the absorption of nutrients and mixing at the periphery of the lumen. This augmentation was greater with highly diffusible nutrients and with high levels of shear-thinning (pseudoplasticity) of the fluid. We compared our results with bulk flows simulations done by previous workers and concluded that villous movements during longitudinal contractions is a major radial mixing mechanism in the small intestine and increases mixing and absorption around the mucosa despite adverse rheology.

  19. Does Mixing Make Residential Ventilation More Effective?

    SciTech Connect

    Sherman, Max; Walker, Iain

    2010-08-16

    Ventilation dilutes or removes indoor contaminants to reduce occupant exposure. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. The total ventilation rate is the most important factor in determining the exposure of occupants to given sources, but the zone- specific distribution of exhaust and supply air, and the mixing of ventilation air can have significant roles. Different types of ventilation systems will provide different amounts of mixing depending on several factors such as air leakage through the building envelope, air distribution systems and the location of sources and occupants. This paper reports recent results of investigations to determine the impact that air mixing has on exposures of residential occupants to prototypical contaminants of concern. Evaluations of existing field measurements and simulations reported in the literature are combined with new analyses to provide an integrated overview of the topic. The results show that for extreme cases additional mixing can be a significant factor but for typical homes looking at average exposures mixing is not helpful and can even make exposures worse.

  20. Multipartite entangled states in particle mixing

    SciTech Connect

    Blasone, M.; Dell'Anno, F.; De Siena, S.; Di Mauro, M.; Illuminati, F.

    2008-05-01

    In the physics of flavor mixing, the flavor states are given by superpositions of mass eigenstates. By using the occupation number to define a multiqubit space, the flavor states can be interpreted as multipartite mode-entangled states. By exploiting a suitable global measure of entanglement, based on the entropies related to all possible bipartitions of the system, we analyze the correlation properties of such states in the instances of three- and four-flavor mixing. Depending on the mixing parameters, and, in particular, on the values taken by the free phases, responsible for the CP-violation, entanglement concentrates in certain bipartitions. We quantify in detail the amount and the distribution of entanglement in the physically relevant cases of flavor mixing in quark and neutrino systems. By using the wave packet description for localized particles, we use the global measure of entanglement, suitably adapted for the instance of multipartite mixed states, to analyze the decoherence, induced by the free evolution dynamics, on the quantum correlations of stationary neutrino beams. We define a decoherence length as the distance associated with the vanishing of the coherent interference effects among massive neutrino states. We investigate the role of the CP-violating phase in the decoherence process.

  1. Mixing Enhancement in a Lobed Injector

    NASA Technical Reports Server (NTRS)

    Smith, L. L.; Majamaki, A. J.; Lam, I. T.; Delabroy, O.; Karagozian, A. R.; Marble, F. E.; Smith, O. I.

    1997-01-01

    An experimental investigation of the non-reactive mixing processes associated with a lobed fuel injector in a coflowing air stream is presented. The lobed fuel injector is a device which generates streamwise vorticity, producing high strain rates which can enhance the mixing of reactants while delaying ignition in a controlled manner. The lobed injectors examined in the present study consist of two corrugated plates between which a fuel surrogate, CO2, is injected into coflowing air. Acetone is seeded in the CO2 supply as a fuel marker. Comparison of two alternative lobed injector geometries is made with a straight fuel injector to determine net differences in mixing and strain fields due to streamwise vorticity generation. Planar laser-induced fluorescence (PLIF) of the seeded acetone yields two-dimensional images of the scalar concentration field at various downstream locations, from which local mixing and scalar dissipation rates are computed. It is found that the lobed injector geometry can enhance molecular mixing and create a highly strained flowfield, and that the strain rates generated by scalar energy dissipation can potentially delay ignition in a reacting flowfield.

  2. 26 CFR 1.1092(b)-4T - Mixed straddles; mixed straddle account (temporary).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... year for which the taxpayer makes the election or January 1, 1984, whichever is later. See § 1.1092(b... Corporation stock or any stock in UVW Corporation. If B makes the mixed straddle account election under this... respect to each other. If B makes the mixed straddle account election under this section for all...

  3. MixSIAR: A Bayesian stable isotope mixing model for characterizing intrapopulation niche variation

    EPA Science Inventory

    Background/Question/Methods The science of stable isotope mixing models has tended towards the development of modeling products (e.g. IsoSource, MixSIR, SIAR), where methodological advances or syntheses of the current state of the art are published in parity with software packa...

  4. Prediction of dynamic and mixing characteristics of drop-laden mixing layers using DNS and LES

    NASA Technical Reports Server (NTRS)

    Okong'o, N.; Leboissetier, A.; Bellan, J.

    2004-01-01

    Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES) have been conducted of a temporal mixing layer laden with evaporating drops, in order to assess the ability of LES to reproduce dynamic and mixing aspects of the DNS which affect combustion, independently of combustion models.

  5. MixSIAR: A Bayesian stable isotope mixing model for characterizing intrapopulation niche variation

    EPA Science Inventory

    Background/Question/Methods The science of stable isotope mixing models has tended towards the development of modeling products (e.g. IsoSource, MixSIR, SIAR), where methodological advances or syntheses of the current state of the art are published in parity with software packa...

  6. Identifying geochemical processes using End Member Mixing Analysis to decouple chemical components for mixing ratio calculations

    NASA Astrophysics Data System (ADS)

    Pelizardi, Flavia; Bea, Sergio A.; Carrera, Jesús; Vives, Luis

    2017-07-01

    Mixing calculations (i.e., the calculation of the proportions in which end-members are mixed in a sample) are essential for hydrological research and water management. However, they typically require the use of conservative species, a condition that may be difficult to meet due to chemical reactions. Mixing calculation also require identifying end-member waters, which is usually achieved through End Member Mixing Analysis (EMMA). We present a methodology to help in the identification of both end-members and such reactions, so as to improve mixing ratio calculations. The proposed approach consists of: (1) identifying the potential chemical reactions with the help of EMMA; (2) defining decoupled conservative chemical components consistent with those reactions; (3) repeat EMMA with the decoupled (i.e., conservative) components, so as to identify end-members waters; and (4) computing mixing ratios using the new set of components and end-members. The approach is illustrated by application to two synthetic mixing examples involving mineral dissolution and cation exchange reactions. Results confirm that the methodology can be successfully used to identify geochemical processes affecting the mixtures, thus improving the accuracy of mixing ratios calculations and relaxing the need for conservative species.

  7. Prediction of dynamic and mixing characteristics of drop-laden mixing layers using DNS and LES

    NASA Technical Reports Server (NTRS)

    Okong'o, N.; Leboissetier, A.; Bellan, J.

    2004-01-01

    Direct Numerical Simulation (DNS) and Large Eddy Simulation (LES) have been conducted of a temporal mixing layer laden with evaporating drops, in order to assess the ability of LES to reproduce dynamic and mixing aspects of the DNS which affect combustion, independently of combustion models.

  8. Geometric uncertainty relation for mixed quantum states

    SciTech Connect

    Andersson, Ole Heydari, Hoshang

    2014-04-15

    In this paper we use symplectic reduction in an Uhlmann bundle to construct a principal fiber bundle over a general space of unitarily equivalent mixed quantum states. The bundle, which generalizes the Hopf bundle for pure states, gives in a canonical way rise to a Riemannian metric and a symplectic structure on the base space. With these we derive a geometric uncertainty relation for observables acting on quantum systems in mixed states. We also give a geometric proof of the classical Robertson-Schrödinger uncertainty relation, and we compare the two. They turn out not to be equivalent, because of the multiple dimensions of the gauge group for general mixed states. We give examples of observables for which the geometric relation provides a stronger estimate than that of Robertson and Schrödinger, and vice versa.

  9. Mixing Ratios of Transitions in 116Sn

    NASA Astrophysics Data System (ADS)

    Cross, David; Pore, J.; Andreoiu, C.; Chester, A. S.; Voss, P.; Bildstein, V.; Demand, G. A.; Diaz Varela, A.; Dunlop, R.; Garrett, P. E.; Hadinia, B.; Jigmeddorj, B.; Laffoley, A.; Liblong, A.; Svensson, C.; Ball, G. C.; Bender, P. C.; Garnsworthy, A.; Hackman, G.; Miller, D.; Noakes, B.; Wang, Z.-M.; Kanungo, R.; Wood, J. L.; Yates, S. W.

    2016-09-01

    The β decay of 116 m 1 , gIn to 116Sn, observed at TRIUMF-ISAC utilizing the 8 π array of 20 HPGe detectors augmented with 5 Si(Li) detectors, produced a high statistics data set from which E2/M1 mixing ratios from γγ angular correlations were obtained. Several new mixing ratios of transitions among the Iπ =4+ states were measured for the first time. In addition, the E0 component of the 42+-->41+ transition was determined. Previous analyses of 116Sn have explained the nature and mixing of the 4+ states on the basis of shared phonon strength. The results presented here indicate that models of 116Sn should explore alternative interpretations of their character. This observation has implications for ongoing theoretical and experimental research on 116Sn and neighboring tin isotopes. This work was supported by NSERC.

  10. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, I.O.

    1993-05-18

    Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7[times]10[sup [minus]3] to about 7[times]10[sup [minus]2] microns and the p.c.m. must be added to the silica in an amount of 80 wt. % or less p.c.m. per combined weight of silica and p.c.m. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a p.c.m. material. The silica-p.c.m. mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

  11. Lidar observation of marine mixed layer

    NASA Technical Reports Server (NTRS)

    Yamagishi, Susumu; Yamanouchi, Hiroshi; Tsuchiya, Masayuki

    1992-01-01

    Marine mixed layer is known to play an important role in the transportation of pollution exiting ship funnels. The application of a diffusion model is critically dependent upon a reliable estimate of a lid. However, the processes that form lids are not well understood, though considerable progress toward marine boundary layer has been achieved. This report describes observations of the marine mixed layer from the course Ise-wan to Nii-jima with the intention of gaining a better understanding of their structure by a shipboard lidar. These observations were made in the summer of 1991. One interesting feature of the observations was that the multiple layers of aerosols, which is rarely numerically modeled, was encountered. No attempt is yet made to present a systematic analysis of all the data collected. Instead we focus on observations that seem to be directly relevant to the structure of the mixed layer.

  12. Mixed-mode fracture of ceramics

    SciTech Connect

    Petrovic, J.J.

    1985-01-01

    The mixed-mode fracture behavior of ceramic materials is of importance for monolithic ceramics in order to predict the onset of fracture under generalized loading conditions and for ceramic composites to describe crack deflection toughening mechanisms. Experimental data on surface flaw mixed-mode fracture in various ceramics indicate that the flaw-plane normal stress at fracture decreases with increasing in-flaw-plane shear stress, although present data exhibit a fairly wide range in details of this sigma - tau relationship. Fracture from large cracks suggests that Mode II has a greater effect on Mode I fracture than Mode III. A comparison of surface flaw and large crack mixed-mode I-II fracture responses indicated that surface flaw behavior is influenced by shear resistance effects.

  13. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, I.O.

    1993-10-19

    Free flowing, conformable powder-like mix of silica particles and a phase change material (pcm) is disclosed. The silica particles have a critical size of about 7[times]10[sup [minus]3] to about 7[times]10[sup [minus]2] microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub. 10 figures.

  14. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, I.O.

    1994-02-01

    Free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a PCM material. The silica-PCM mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub. 2 figures.

  15. Turbulent jet mixing in a supersonic stream

    NASA Technical Reports Server (NTRS)

    Swanson, R. C.; Schetz, J. A.

    1971-01-01

    An experimental study of turbulent, subsonic, coaxial jet mixing of air in a supersonic air stream is presented. Data taken at five axial stations downstream of the exit of the jet supply tube, which was suspended through the nozzle throat of a supersonic wind tunnel, are given in the form of total pressure, Mach number, and velocity distributions. An investigation of the effect of swirl as a mixing aid was conducted. Swirl, produced by tangential injection of 50% of the total air mass flow leaving the jet supply tube, was examined through Schlieren photographs and total pressure surveys. From a comparison of nonswirl and swirl data, it is concluded that the swirl has no discernible effect on the mixing.

  16. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, Ival O.

    1992-01-01

    Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

  17. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, Ival O.

    1993-01-01

    Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garmets, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

  18. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, Ival O.

    1993-01-01

    Free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7.times.10.sup.-3 to about 7.times.10.sup.-2 microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

  19. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, Ival O.

    1994-01-01

    Free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a PCM material. The silica-PCM mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub.

  20. Zero-gravity transient thermal mixing simulation

    NASA Technical Reports Server (NTRS)

    Lands, J. F., Jr.; Ried, R. C., Jr.

    1971-01-01

    The experimental program described is an outgrowth of independent investigations into alternate redesign concepts for the Apollo SM cryogenic oxygen storage system. The experiments were continued, after the redesign was established, to provide physical insight into transient thermal mixing in zero-gravity and to aid in the characterization of the system performance in flight. Zero-gravity heat transfer and fluid mixing were simulated experimentally through an analogy between unsteady heat conduction and species diffusion. To further support numerical analyses of the cryogenic oxygen storage system, the experimental investigation was extended to include a cubical tank geometry, representative of existing numerical models. In general, the transient flow patterns in the cubical tank are far more complex than those of the spherical tank and the extent of fluid mixing is significantly greater but less repeatable.

  1. Mixed parity pairing in a dipolar gas

    NASA Astrophysics Data System (ADS)

    Bruun, G. M.; Hainzl, C.; Laux, M.

    2016-10-01

    We show that fermionic dipoles in a two-layer geometry form Cooper pairs with both singlet and triplet components when they are tilted with respect to the normal of the planes. The mixed parity pairing arises because the interaction between dipoles in the two different layers is not inversion symmetric. We use an efficient eigenvalue approach to calculate the zero-temperature phase diagram of the system as a function of the dipole orientation and the layer distance. The phase diagram contains purely triplet as well as mixed singlet and triplet superfluid phases. We show in detail how the pair wave function for dipoles residing in different layers smoothly changes from singlet to triplet symmetry as the orientation of the dipoles is changed. Our results indicate that dipolar quantum gases can be used to unambiguously observe mixed parity pairing.

  2. Mixed surfactant systems for enhanced oil recovery

    SciTech Connect

    Llave, F.M.; Gall, B.L.; Noll, L.A.

    1990-12-01

    The results of an evaluation of mixed surfactant systems for enhanced oil recovery are described. Several surfactant combinations have been studied. These include alkyl aryl sulfonates as primary surfactants and carboxymethylated ethoxylated (CME) surfactants and ethoxylated sulfonates (ES) as secondary surfactants. The ethoxylated surfactants increase the salinity tolerance of the primary surfactants and, in theory, allow tailoring of the surfactant system to match selected reservoir conditions. The experiments conducted included interfacial tension (IFT) measurements, phase behavior measurements, adsorption and/or chromatographic separation of mixed surfactant systems, measurements of solution properties such as the critical micelle concentration (CMC) of surfactant mixtures, and crude oil displacement experiments. The effects of temperature, surfactant concentration, salinity, presence of divalent ions, hydrocarbon type, and component proportions in the mixed surfactant combinations, and injection strategies on the performance potential of the targeted surfactant/hydrocarbon systems were studied. 40 refs., 37 figs., 8 tabs.

  3. Experiences with treatment of mixed waste

    SciTech Connect

    Dziewinski, J.; Marczak, S.; Smith, W.H.; Nuttall, E.

    1996-04-10

    During its many years of research activities involving toxic chemicals and radioactive materials, Los Alamos National Laboratory (Los Alamos) has generated considerable amounts of waste. Much of this waste includes chemically hazardous components and radioisotopes. Los Alamos chose to use an electrochemical process for the treatment of many mixed waste components. The electro-chemical process, which the authors are developing, can treat a great variety of waste using one type of equipment built at a moderate expense. Such a process can extract heavy metals, destroy cyanides, dissolve contamination from surfaces, oxidize toxic organic compounds, separate salts into acids and bases, and reduce the nitrates. All this can be accomplished using the equipment and one crew of trained operating personnel. Results of a treatability study of chosen mixed wastes from Los Alamos Mixed Waste Inventory are presented. Using electrochemical methods cyanide and heavy metals bearing wastes were treated to below disposal limits.

  4. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, I.O.

    1992-04-21

    A free flowing, conformable powder-like mix of silica particles and a phase change material (p.c.m.) is disclosed. The silica particles have a critical size of about 7 [times] 10[sup [minus]3] to about 7 [times] 10[sup [minus]2] microns and the pcm must be added to the silica in an amount of 80 wt. % or less pcm per combined weight of silica and pcm. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and in cementitious compositions of the type in which it is beneficial to use a pcm material. The silica-pcm mix can also be admixed with soil to provide a soil warming effect and placed about a tree, flower, or shrub. 9 figs.

  5. On the measurement of hospital case mix.

    PubMed

    Klastorin, T D; Watts, C A

    1980-06-01

    This article discusses a number of issues related to the measurement of hospital diagnostic case mix. We initially examine a number of previous attempts to measure case mix based on surrogate measures (e.g., facilities and services) and information from predetermined discharge-classification systems. Since a number of researchers have attempted to reduce diagnostic classification data into a single-valued (i.e., scalar) case mix index, we then discuss a number of concepts and assumptions implicit in the construction of such indices. Among these assumptions is the property of functional homogeneity; this property and a methodology baed on Q-type factor analysis for testing for the presence of this property are defined. In order to illustrate the use of the methodology, it is applied to data from 153 hospitals in downstate New York.

  6. Passive scalar mixing in vortex rings

    NASA Astrophysics Data System (ADS)

    Sau, Rajes; Mahesh, Krishnan

    2006-11-01

    Direct numerical simulations of passive scalar mixing in vortex rings are performed, with and without crossflow. The simulation results without crossflow agree well with experimental data for `formation number', total circulation, trajectory and entrainment fraction. Scalar profiles, mixedness and volume of scalar carrying fluid are used to quantify mixing, whose characteristics are quite different in the formation and propagation phases of the ring. These results are explained in terms of entrainment by the ring. The simulations with crossflow show that the ring tilts and deforms. When the stroke ratio is greater than formation number, the ring tilts in the direction of the crossflow. On the other hand, when the stroke ratio is less than formation number, the ring tilts in the opposite direction, such that its induced velocity opposes the crossflow. The Magnus effect may be used to provide a simple explanation. The impact of this behavior on mixing will be discussed.

  7. Mixing characterization in a slab tank

    SciTech Connect

    Stoots, C.M.; Gavlak, A.M.; Calabrese, R.V.; Kyser, E.A.; Tatterson, G.B.

    1989-01-01

    Due to safety requirements, slab tanks are often used to process radioactive materials. The configuration is that of a slit or a tank of rectangular cross section with very low aspect ratio. Due to its nonconventional geometry, very little is known about the slab tank mixing environment. To better understand it, experiments have been performed in a full scale standard configuration equipped with two stirrer shafts, each containing several axial impellers. To characterize the velocity field, mean and RMS turbulent velocities have been measured at several impeller speeds with a two-component Laser Doppler Anemometer (LDA). The LDA data have been supplemented with flow visualization, circulation time, and mixing time studies. Since the slab tank is often used as a precipitator, solids suspension studies have also been performed. The results of the various experiments will be presented and will be interpreted to elucidate slab tank dynamics. The implication to mixing efficiency will also be discussed.

  8. Effective mixing strategies with microbubble streaming flows

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Rallabandi, Bhargav; Guo, Lin; Hilgenfeldt, Sascha

    2013-11-01

    Homogeneous mixing of chemical/biological samples and reagents is one of the essential preparation steps for lab-on-a-chip systems. As effective Stokes flows driven by fast time scale oscillatory flows, microbubble streaming flows are a tool uniquely positioned between passive and active mixing approaches. Guided by thorough theoretical understanding of the flows and of micromixing itself, we investigate various designs of microbubble mixers, employing two key strategies: (a) introducing controlled unsteadiness in the acoustic driving pattern, e.g. by duty-cycling and driving frequency modulation, and (b) optimizing the arrangement of multiple bubbles, such as the number, position, and orientation of the microbubbles, particularly to generate 3D chaotic flow patterns. Both of these approaches significantly improve mixing over that of previous steady 2D bubble micro-mixers, and the strategies can be combined for greater effect. Current address: Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology

  9. Designing a Mixed Reality Intergenerational Entertainment System

    NASA Astrophysics Data System (ADS)

    Khoo, Eng Tat; Merritt, Tim; Cheok, Adrian David

    This chapter presents steps for designing an intergenerational mixed reality entertainment system, which focuses on physical and social interactions using a mixed reality floor system. The main design goals include the following: facilitating interactions between users with varied levels of skill in utilizing technology, utilizing the familiar physical motions from other activities to make an intuitive physical interface, and encouraging social interactions among families and friends. Detailed implementation of these steps is presented in the design of our intergenerational entertainment system, Age Invaders. Our design process is based on user-centered design. The results of the study help to focus the refinements of the existing platform from a usability standpoint and also aid in the development of new physical entertainment and interactive applications. This study provides insights into user issues including how users interact in a complex mixed reality experience.

  10. Superlubricity of a Mixed Aqueous Solution

    NASA Astrophysics Data System (ADS)

    Ma, Zhi-Zuo; Zhang, Chen-Hui; Luo, Jian-Bin; Lu, Xin-Chun; Wen, Shi-Zhu

    2011-05-01

    A super-low friction coefficient of 0.0028 is measured under a pressure of 300 MPa when the friction pair (the silicon nitride ball sliding on the silicate glass) is lubricated by the mixed aqueous solution of glycerol and boric acid. The morphorlogies of the hydroxylated glass plate are observed by an atomic force microscope (AFM) in deionized water, glycerol, boric acid and their mixed aqueous solution. Bonding peaks of the retained liquids adhered on the surface of the sliding track are detected by an infrared spectrum apparatus and a Raman spectrum apparatus. The mechanism of the superlubricity of the glycerol and boric acid mixed aqueous solution is discussed. It is deduced that the formation of the lubricant film has enough strength to support higher loads, the hydration effect offering the super lower shear resistance. Key words: superlubricity, water based lubricant, ultra-low friction

  11. Evidence for D0-D0 mixing.

    PubMed

    Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Grauges, E; Lopez, L; Palano, A; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Ronan, M T; Tackmann, K; Wenzel, W A; Del Amo Sanchez, P; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Schroeder, T; Steinke, M; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Williams, D C; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Brandt, T; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Béquilleux, J; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Fisher, P H; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, G; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Leruste, Ph; Malclès, J; Ocariz, J; Perez, A; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; D'Orazio, A; del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Roethel, W; Wilson, F F; Aleksan, R; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Hryn'ova, T; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H

    2007-05-25

    We present evidence for D0-D(0) mixing in D(0)-->K(+)pi(-) decays from 384 fb(-1) of e(+)e(-) colliding-beam data recorded near square root s=10.6 GeV with the BABAR detector at the PEP-II storage rings at the Stanford Linear Accelerator Center. We find the mixing parameters x('2)=[-0.22+/-0.30(stat)+/-0.21(syst)] x 10(-3) and y(')=[9.7+/-4.4(stat)+/-3.1(syst)] x 10(-3) and a correlation between them of -0.95. This result is inconsistent with the no-mixing hypothesis with a significance of 3.9 standard deviations. We measure R(D), the ratio of doubly Cabibbo-suppressed to Cabibbo-favored decay rates, to be [0.303+/-0.016(stat)+/-0.010(syst)]%. We find no evidence for CP violation.

  12. Convex set and linear mixing model

    NASA Technical Reports Server (NTRS)

    Xu, P.; Greeley, R.

    1993-01-01

    A major goal of optical remote sensing is to determine surface compositions of the earth and other planetary objects. For assessment of composition, single pixels in multi-spectral images usually record a mixture of the signals from various materials within the corresponding surface area. In this report, we introduce a closed and bounded convex set as a mathematical model for linear mixing. This model has a clear geometric implication because the closed and bounded convex set is a natural generalization of a triangle in n-space. The endmembers are extreme points of the convex set. Every point in the convex closure of the endmembers is a linear mixture of those endmembers, which is exactly how linear mixing is defined. With this model, some general criteria for selecting endmembers could be described. This model can lead to a better understanding of linear mixing models.

  13. Lithofacies and cyclicity of the Yates Formation, Permian basin: Implications for reservoir heterogeneity

    SciTech Connect

    Borer, J.M.; Harris, P.M. )

    1991-04-01

    Siliciclastics of the Yates Formation (Permian, upper Guadalupian) are significant hydrocarbon reservoirs in the US Permian basin. Subsurface and outcrop data show that the most porous lithofacies occur in a clastic-dominated middle shelf and that evaporitic inner shelf and carbonate outer shelf equivalents are mostly nonporous. Lithofacies relations and much of the heterogeneity in Yates reservoirs are related to the stacking of depositional sequences (i.e., siliciclastic-carbonate alternations and sandstone-argillaceous siltstone alternations) in response to three orders of orbitally forced, low-amplitude, eustatic variation. In general, siliciclastics dominated the Yates shelf during lowstand parts of asymmetric, 400-k.y. sea level fluctuations, whereas carbonates were deposited during sea level highstands. The character and position of sand depocenters on the Yates shelf during these lowstands were controlled by a longer duration third-order sea level variation. Shorter duration cycles controlled the heterogeneity within the 400-k.y. depositional sequences. The variation in cycle packaging, lithology, and reservoir quality between the Central Basin platform and Northwest shelf may be a response of eustatic variation on parts of the shelf with different slopes or subsidence profiles. The lithofacies described from the Yates Formation and the deposition model proposed to explain the stratigraphy may be valuable as analogs in other basins containing mixed siliciclastic-carbonate settings.

  14. Pulse Jet Mixing Tests With Noncohesive Solids

    SciTech Connect

    Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.; Fort, James A.; Wells, Beric E.; Sundaram, S. K.; Scott, Paul A.; Minette, Michael J.; Smith, Gary L.; Burns, Carolyn A.; Greenwood, Margaret S.; Morgen, Gerald P.; Baer, Ellen BK; Snyder, Sandra F.; White, Michael K.; Piepel, Gregory F.; Amidan, Brett G.; Heredia-Langner, Alejandro

    2012-02-17

    This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid. The tests were conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants, and the test data were used to develop models predicting two measures of mixing performance for full-scale WTP vessels. The models predict the cloud height (the height to which solids will be lifted by the PJM action) and the critical suspension velocity (the minimum velocity needed to ensure all solids are suspended off the floor, though not fully mixed). From the cloud height, the concentration of solids at the pump inlet can be estimated. The predicted critical suspension velocity for lifting all solids is not precisely the same as the mixing requirement for 'disturbing' a sufficient volume of solids, but the values will be similar and closely related. These predictive models were successfully benchmarked against larger scale tests and compared well with results from computational fluid dynamics simulations. The application of the models to assess mixing in WTP vessels is illustrated in examples for 13 distinct designs and selected operational conditions. The values selected for these examples are not final; thus, the estimates of performance should not be interpreted as final conclusions of design adequacy or inadequacy. However, this work does reveal that several vessels may require adjustments to design, operating features, or waste feed properties to ensure confidence in operation. The models described in this report will prove to be valuable engineering tools to evaluate options as designs are finalized for the WTP. Revision 1 refines data sets used for model development and summarizes models developed since the completion of Revision 0.

  15. NUCLEAR MIXING METERS FOR CLASSICAL NOVAE

    SciTech Connect

    Kelly, Keegan J.; Iliadis, Christian; Downen, Lori; Champagne, Art; José, Jordi

    2013-11-10

    Classical novae are caused by mass transfer episodes from a main-sequence star onto a white dwarf via Roche lobe overflow. This material possesses angular momentum and forms an accretion disk around the white dwarf. Ultimately, a fraction of this material spirals in and piles up on the white dwarf surface under electron-degenerate conditions. The subsequently occurring thermonuclear runaway reaches hundreds of megakelvin and explosively ejects matter into the interstellar medium. The exact peak temperature strongly depends on the underlying white dwarf mass, the accreted mass and metallicity, and the initial white dwarf luminosity. Observations of elemental abundance enrichments in these classical nova events imply that the ejected matter consists not only of processed solar material from the main-sequence partner but also of material from the outer layers of the underlying white dwarf. This indicates that white dwarf and accreted matter mix prior to the thermonuclear runaway. The processes by which this mixing occurs require further investigation to be understood. In this work, we analyze elemental abundances ejected from hydrodynamic nova models in search of elemental abundance ratios that are useful indicators of the total amount of mixing. We identify the abundance ratios ΣCNO/H, Ne/H, Mg/H, Al/H, and Si/H as useful mixing meters in ONe novae. The impact of thermonuclear reaction rate uncertainties on the mixing meters is investigated using Monte Carlo post-processing network calculations with temperature-density evolutions of all mass zones computed by the hydrodynamic models. We find that the current uncertainties in the {sup 30}P(p, γ){sup 31}S rate influence the Si/H abundance ratio, but overall the mixing meters found here are robust against nuclear physics uncertainties. A comparison of our results with observations of ONe novae provides strong constraints for classical nova models.

  16. Microsecond Molecular Dynamics Simulations of Lipid Mixing

    PubMed Central

    2015-01-01

    Molecular dynamics (MD) simulations of membranes are often hindered by the slow lateral diffusion of lipids and the limited time scale of MD. In order to study the dynamics of mixing and characterize the lateral distribution of lipids in converged mixtures, we report microsecond-long all-atom MD simulations performed on the special-purpose machine Anton. Two types of mixed bilayers, POPE:POPG (3:1) and POPC:cholesterol (2:1), as well as a pure POPC bilayer, were each simulated for up to 2 μs. These simulations show that POPE:POPG and POPC:cholesterol are each fully miscible at the simulated conditions, with the final states of the mixed bilayers similar to a random mixture. By simulating three POPE:POPG bilayers at different NaCl concentrations (0, 0.15, and 1 M), we also examined the effect of salt concentration on lipid mixing. While an increase in NaCl concentration is shown to affect the area per lipid, tail order, and lipid lateral diffusion, the final states of mixing remain unaltered, which is explained by the largely uniform increase in Na+ ions around POPE and POPG. Direct measurement of water permeation reveals that the POPE:POPG bilayer with 1 M NaCl has reduced water permeability compared with those at zero or low salt concentration. Our calculations provide a benchmark to estimate the convergence time scale of all-atom MD simulations of lipid mixing. Additionally, equilibrated structures of POPE:POPG and POPC:cholesterol, which are frequently used to mimic bacterial and mammalian membranes, respectively, can be used as starting points of simulations involving these membranes. PMID:25237736

  17. Mixing processes within the polar night jet

    NASA Technical Reports Server (NTRS)

    Pierce, R. Bradley; Fairlie, T. Duncan; Grose, William L.; Swinbank, Richard; O'Neill, Alan

    1994-01-01

    Lagrangian material line simulations are performed using U.K. Meteorological Office simulated winds and temperatures to examine mixing processes in the middle- and lower-stratospheric polar night jet during the 1992 Southern Hemisphere spring and Northern Hemisphere winter. The Lagrangian simulations are undertaken to provide insight into the effects of mixing within the polar night jet on observations of the polar vortex made by instruments onboard the Upper Atmosphere Research Satellite (UARS) during these periods. A moderate to strong kinematic barrier to large-scale isentropic exchange, similar to the barrier identified in General Circulation Model (GCM) simulations, is identified during both of these periods. Characteristic timescales for mixing by large-scale isentropic motions within the polar night jet range from 20 days in the Southern Hemisphere lower stratosphere to years in the Northern Hemisphere middle stratosphere. The long mixing timescales found in the Northern Hemisphere polar night jet do not persist. Instead, the Northern Hemisphere kinematic barriers are broken down as part of the large-scale stratospheric response to a strong tropospheric blocking event. A series of Lagrangian experiments are conducted to investigate the sensitivity of the kinematic barrier to diabatic effects and to small-scale inertial gravity wave motions. Differential diabatic descent is found to have a significant impact on mixing processes within the Southern Hemisphere middle-stratospheric jet core. The interaction between small-scale displacements by idealized, inertial gravity waves and the large-scale flow is found to have a significant impact on mixing within the polar night jet in both hemispheres. These sensitivity experiments suggest that scales of motion that are unresolved in global assimilated datasets may contribute to mass exchange across the kinematic barrier to large-scale isentropic motion.

  18. Scoping Study of Airlift Circulation Technologies for Supplemental Mixing in Pulse Jet Mixed Vessels

    SciTech Connect

    Schonewill, Philip P.; Berglin, Eric J.; Boeringa, Gregory K.; Buchmiller, William C.; Burns, Carolyn A.; Minette, Michael J.

    2015-04-07

    At the request of the U.S. Department of Energy Office of River Protection, Pacific Northwest National Laboratory (PNNL) conducted a scoping study to investigate supplemental technologies for supplying vertical fluid motion and enhanced mixing in Waste Treatment and Immobilization Plant (WTP) vessels designed for high solids processing. The study assumed that the pulse jet mixers adequately mix and shear the bottom portion of a vessel. Given that, the primary function of a supplemental technology should be to provide mixing and shearing in the upper region of a vessel. The objective of the study was to recommend a mixing technology and configuration that could be implemented in the 8-ft test vessel located at Mid-Columbia Engineering (MCE). Several mixing technologies, primarily airlift circulator (ALC) systems, were evaluated in the study. This technical report contains a review of ALC technologies, a description of the PNNL testing and accompanying results, and recommended features of an ALC system for further study.

  19. Friendship in high-functioning children with autism spectrum disorder: mixed and non-mixed dyads.

    PubMed

    Bauminger, Nirit; Solomon, Marjorie; Aviezer, Anat; Heung, Kelly; Brown, John; Rogers, Sally J

    2008-08-01

    Friendships containing a child with autism and a friend with typical development ("mixed" friendships, n = 26) and those of children with autism and a friend with a disability ("non-mixed," n = 16) were contrasted with friendships of typically developing subjects and their friends (n = 31). Measures included dyadic interaction samples, and interview and questionnaire data from subjects, friends, and parents. Mixed friendship interactions resembled typical friendships. Participants in mixed friendships were more responsive to one another, had stronger receptive language skills, exhibited greater positive social orientation and cohesion, and demonstrated more complex coordinated play than in the non-mixed dyads. Exposure to typical peers appears to have significant effects on friendship behaviors.

  20. Improvements in Mixing Time and Mixing Uniformity in Devices Designed for Studies of Protein Folding Kinetics

    SciTech Connect

    Yao, Shuhuai; Bakajin, Olgica

    2007-08-01

    Using a microfluidic laminar flow mixer designed for studies of protein folding kinetics, we demonstrate a mixing time of 1 +/- 1 micros with sample consumption on the order of femtomoles. We recognize two limitations of previously proposed designs: (1) size and shape of the mixing region, which limits mixing uniformity and (2) the formation of Dean vortices at high flow rates, which limits the mixing time. We address these limitations by using a narrow shape-optimized nozzle and by reducing the bend of the side channel streamlines. The final design, which combines both of these features, achieves the best performance. We quantified the mixing performance of the different designs by numerical simulation of coupled Navier-Stokes and convection-diffusion equations and experiments using fluorescence resonance energy-transfer (FRET)-labeled DNA.

  1. Neutrino Masses and Mixing from Supersymmetric Inflation

    NASA Astrophysics Data System (ADS)

    Lazarides, G.

    A supersymmetric model based on a l-right symmetric gauge group is proposed where hybrid inflation, baryogenesis and neutrino oscillations are linked.This scheme, supplemented by a familiar ansatz for the neutrino Dirac masses and mixing of the two heaviest families and with the MSW resolution of the solar neutrino puzzle, implies that 1 eVmντ ≲ 9 eV. The mixing angle θμτ is predicted to lie in a narrow range which will be partially tested by the Chorus/Nomad experiment.

  2. B^0_s mixing at CDF

    SciTech Connect

    Piedra, Jonatan; /Paris U., VI-VII

    2006-08-01

    The Tevatron collider at Fermilab provides a very rich environment for the study of b-hadrons. One of the most important analyses within the B physics program of the CDF experiment is B{sub s}{sup 0} mixing. Since the time this school was held, several improvements in the B{sub s}{sup 0} mixing analysis have made possible the measurement of the B{sub s}{sup 0} oscillation frequency, result that has been presented at the FPCP 2006 Conference.

  3. Histogenesis of ovarian malignant mixed mesodermal tumours.

    PubMed Central

    Clarke, T J

    1990-01-01

    The histogenesis of ovarian malignant mixed mesodermal tumours, which includes the concept of metaplastic carcinoma, is controversial. Four such tumours were examined for evidence of metaplastic transition from carcinoma to sarcoma using morphology and reticulin stains. Consecutive sections were stained immunohistochemically using cytokeratin and vimentin to determine whether cells at the interface between carcinoma and sarcoma expressed both cytokeratin and vimentin. There was no evidence of morphological, architectural, or immunohistochemical transitions from carcinoma to sarcoma in the four tumours studied. This suggests that ovarian malignant mixed mesodermal tumours are not metaplastic carcinomas but are composed of histogenetically different elements. Images PMID:2160478

  4. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, I.O.

    1994-12-06

    A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft. 3 figures.

  5. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, Ival O.

    1995-01-01

    A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft.

  6. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, I.O.

    1995-12-26

    A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft. 3 figs.

  7. Dry powder mixes comprising phase change materials

    DOEpatents

    Salyer, Ival O.

    1994-01-01

    A free flowing, conformable powder-like mix of silica particles and a phase change material (PCM) is provided. The silica particles have a critical size of about 0.005 to about 0.025 microns and the PCM must be added to the silica in an amount of 75% or less PCM per combined weight of silica and PCM. The powder-like mix can be used in tableware items, medical wraps, tree wraps, garments, quilts and blankets, and particularly in applications for heat protection for heat sensitive items, such as aircraft flight recorders, and for preventing brake fade in automobiles, buses, trucks and aircraft.

  8. A Stratospheric Mixing and Transport Sampler

    NASA Technical Reports Server (NTRS)

    Sparling, Lynn

    1999-01-01

    The mixing and transport of stratospheric chemical species occurs by a variety of physical mechanisms on a range of length and time scales. Slow vertical diffusion resembles Taylor diffusion in pipe flow, while rapid stirring by chaotic advection is essentially a "baker's transformation", via the stretching and folding of material lines in the flow. Other examples include global scale transport by large organized flow structures, such as the winter stratospheric "eggbeater" that brings tropical air to the north pole. This presentation is a survey of these different mixing and transport phenomena and how we see their signatures in observations of chemical tracers.

  9. Transition mixing study empirical model report

    NASA Technical Reports Server (NTRS)

    Srinivasan, R.; White, C.

    1988-01-01

    The empirical model developed in the NASA Dilution Jet Mixing Program has been extended to include the curvature effects of transition liners. This extension is based on the results of a 3-D numerical model generated under this contract. The empirical model results agree well with the numerical model results for all tests cases evaluated. The empirical model shows faster mixing rates compared to the numerical model. Both models show drift of jets toward the inner wall of a turning duct. The structure of the jets from the inner wall does not exhibit the familiar kidney-shaped structures observed for the outer wall jets or for jets injected in rectangular ducts.

  10. A Mixed Finite Analysis of Axial Foreshortening

    NASA Technical Reports Server (NTRS)

    Ruzicka, Gene; Rutkowski, Michael (Technical Monitor)

    2000-01-01

    In previous studies, a mixed finite element was derived and shown to be effective in facilitating accurate modal reduction of rotor blades. This study builds upon that earlier work through the development of algorithms that allow the element's Lagrangian axial displacement degrees of freedom to be eliminated in favor of the axial force degrees of freedom. This reduction process, which had been demonstrated previously for the case of a single mixed finite element, may be viewed as a generalization of the UMARC blade analysis methodology to arbitrary topologies. A unique strength of the method. developed here is that the model may consist of two dimensional or even three dimensional elements.

  11. A Mixed Approach Of Automated ECG Analysis

    NASA Astrophysics Data System (ADS)

    De, A. K.; Das, J.; Majumder, D. Dutta

    1982-11-01

    ECG is one of the non-invasive and risk-free technique for collecting data about the functional state of the heart. However, all these data-processing techniques can be classified into two basically different approaches -- the first and second generation ECG computer program. Not the opposition, but simbiosis of these two approaches will lead to systems with the highest accuracy. In our paper we are going to describe a mixed approach which will show higher accuracy with lesser amount of computational work. Key Words : Primary features, Patients' parameter matrix, Screening, Logical comparison technique, Multivariate statistical analysis, Mixed approach.

  12. Group theory and dynamics of neutrino mixing

    NASA Astrophysics Data System (ADS)

    Lam, C. S.

    2011-06-01

    There is a direct group-theoretical connection between neutrino mixing and horizontal symmetry that can be established without any dynamical input. Such a connection is reviewed and expanded in this article. For certain symmetry groups G including A4 and S4, it is shown that a generic U(1)×G Higgs potential of a valon yields exactly the alignments dictated by the group-theoretical approach, but energy can now be used to discriminate different alignments. This mechanism possibly explains why starting from an A4 group, the tribimaximal mixing matrix with an enhanced S4 symmetry is more preferable than the one without it.

  13. Mixed-Mode-Bending Delamination Apparatus

    NASA Technical Reports Server (NTRS)

    Crews, John H., Jr.; Reeder, James R.

    1991-01-01

    Mixed-mode-bending delamination apparatus generates two types of delamination stress simultaneously in specimen from single externally applied point load. In technique, indivial mode I and mode II contributions to delamination in specimen analyzed by use of simple beam-theory equations, eliminating need for time-consuming, difficult numerical analysis. Allows wider range of mode I/mode II ratios than possible with many other methods. Mixed-mode delamination testing of interest in all fields utilizing composite materials, used mostly in aerospace field, but also used in automobiles, lightweight armored military vehicles, boats, and sporting equipment. Useful in general lumber, plywood, and adhesive industries, as well.

  14. Multitasking and mixed systems for provider payment.

    PubMed

    Eggleston, Karen

    2005-01-01

    The problem of multitasking refers to the challenge of designing incentives to motivate appropriate effort across multiple tasks when the desired outcomes for some tasks are more difficult to measure than others. Multitasking is pervasive in health care. I use a simple model to show that the problem of multitasking further strengthens conventional arguments for mixed payment systems such as partial capitation. When pay-for-performance metrics are imperfect for rewarding service-specific quality efforts, using mixed payment helps to balance incentives for quality effort across services.

  15. Photochemistry and vertical mixing. [in Uranus atmosphere

    NASA Technical Reports Server (NTRS)

    Atreya, S. K.; Sandel, B. R.; Romani, P. N.

    1991-01-01

    Earth-based observations relevant to the question of photochemistry and vertical mixing are discussed. Phytolysis of methane, the only known photochemically active volatile in the Uranian atmosphere, produces heavier hydrocarbons, the most abundant of which are ethane, acetylene, and the polyacetylenes. Unlike Jupiter and Saturn, these hydrocarbon products condense at the low temperatures prevalent in the middle atmosphere. Contrary to the pre-Voyager notion that the atmosphere of Uranus is remarkable clear, it is found that the aerosols are widely and extensively distributed. Despite its photodestruction, methane remains stable in the Uranian atmosphere. The vertical mixing on Uranus is found to be the least efficient of any of the planetary atmospheres.

  16. Overview of robotics for Mixed Waste Operations

    SciTech Connect

    Ward, C.R.

    1994-02-01

    The Mixed Waste Operations Robotics program is developing robotics technology to make the handling and treatment of Department of Energy mixed waste; better, faster, safer and cheaper. This technology will provide remote operations and not require humans to be in contact with this radioactive and hazardous waste. The technology includes remote handling and opening of waste containers, remote removal of waste from the containers, remote characterization and sorting of the waste, and remote treatment and disposition of the waste. The initial technology development program culminated in an integrated demonstration in November 1993 and each aspect of this technology is described.

  17. Heat Transfer Problems of Mixed Refrigerants

    NASA Astrophysics Data System (ADS)

    Fujii, Tetsu; Koyama, Shigeru; Goto, Masao; Takamatsu, Hiroshi

    From the point of view of the application of non-azeotropic mixed refrigerants to heat pump and refrigeration cycles, literatures on condensation and evaporation are surveyed and future problems to be studied are extracted. All researches on the relevant problems are recently started and still in developing way except for condensation on a single horizontal tube. Particularly, the studies for condensation and evaporation of mixed Freon refrigerant in a horizontal tube, which are the most important in practice, are far backward in comparison with single component refrigerant in every point of heat transfer characteristics, flow pattern and theoretical analysis.

  18. Nondestructive assay confirmatory assessment experiments: mixed oxide

    SciTech Connect

    Lemming, J.F.

    1980-04-30

    The confirmatory assessment experiments demonstrate traceable nondestructive assay (NDA) measurements of plutonium in mixed oxide powder using commercially available spontaneous-fission assay systems. The experiments illustrate two major concepts: the production of calibration materials using calorimetric assay, and the use of paired measurements for measurement assurance. Two batches of well-characterized mixed oxide powder were used to establish the random and systematic error components. The major components of an NDA measurement assurance technique to establish and maintain traceability are identified and their functions are demonstrated. 20 refs., 10 figs., 10 tabs.

  19. Medicare case-mix index increase

    PubMed Central

    Ginsburg, Paul B.; Carter, Grace M.

    1986-01-01

    Medicare paid hospitals a higher amount per admission in 1984 than had been planned because the case-mix index (CMI), which reflects the proportion of patients in high-weighted DRG's versus low-weighted ones, increased more than had been projected. This study estimated the degree to which the increase in the CMI from 1981 reflected medical practice changes, the aging of the Medicare inpatient population, changes in coding practices of physicians and hospitals, and changes in the way that the Health Care Financing Administration collects the data on case-mix. All of the above, except for aging, contributed to the increase in the CMI. PMID:10311672

  20. Mixed Media Filters for Aircrew Breathing Systems.

    DTIC Science & Technology

    1980-12-01

    F AD-AiLT1 382 UMPQUA RESEARCH CO MYRTLE CREEK OR F/S 6/11 I MIXED MEDIA FILTERS FOR AIRCREW BREATHING SYSTEMS. CU) IDEC 80 G V COLOMBO F33615-76-C...O603 UNCLASSIFIED SAMTR-60-27 NL C Report SAM-TR-80.27 00 lot MIXED MEDIA FILTERS FOR AIRCREW BREATHING SYSTEMS Gerald V. Colombo, M.S. Umpqua Research...Texas 78235 0 ’: 0 010 T .A NOTICES This final report was submitted by Umpqua Research Company, Myrtle Creek, Oregon 97457, under contract F33615-76-C