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Sample records for deciphering formation processes

  1. Deciphering the influence of the thermal processes on the early passive margins formation

    NASA Astrophysics Data System (ADS)

    Bousquet, Romain; Nalpas, Thierry; Ballard, Jean-François; Ringenbach, Jean-Claude; Chelalou, Roman; Clerc, Camille

    2015-04-01

    Many large-scale dynamic processes, from continental rifting to plate subduction, are intimately linked to metamorphic reactions. This close relation between geodynamic processes and metamorphic reactions is, in spite of appearances, yet poorly understood. For example, during extension processes, rocks will be exposed to important temperature, pressures and stress changes. Meanwhile less attention has been paid to other important aspects of the metamorphic processes. When reacting rocks expand and contract, density and volume changes will set up in the surrounding material. While several tectonic models are proposed to explain the formation of extensive basins and passive margins ( simple shear detachment mantle exhumation .... ) a single thermal model (McKenzie , 1978), as a dogma, is used to understanding and modeling the formation and evolution of sedimentary basins . This model is based on the assumption that the extension is only by pure shear and it is instantaneous. Under this approach, the sedimentary deposits occur in two stages. i) A short step , 1 to 10 Ma , controlled by tectonics. ii) A longer step , at least 50 Ma as a result of the thermal evolution of the lithosphere.
However, most stratigraphic data indicate that less thermal model can account for documented vertical movements. The study of the thermal evolution , coupled with other tectonic models , and its consequences have never been studied in detail , although the differences may be significant and it is clear that the petrological changes associated with changes in temperature conditions , influence changes reliefs.
In addition, it seems that the relationship between basin formation and thermal evolution is not always the same:
- Sometimes the temperature rise above 50 to 100 Ma tectonic extension. In the Alps, a significant rise in geothermal gradient Permo -Triassic followed by a "cold" extension , leading to the opening of the Ligurian- Piedmont ocean, from the Middle Jurassic .

  2. Deciphering site formation processes through soil micromorphology at Contrebandiers Cave, Morocco.

    PubMed

    Aldeias, Vera; Goldberg, Paul; Dibble, Harold L; El-Hajraoui, Mohamed

    2014-04-01

    Contrebandiers Cave preserves a Late Pleistocene sequence containing Middle Stone Age (MSA) so-called Maghrebian Mousterian and Aterian occupations, spanning from ∼126 to 95 ka (thousands of years ago), followed by spatially restricted Iberomaurusian industries. Micromorphological analyses, complemented by instrumental mineralogical identification and fabric orientation, allowed for the reconstruction of the main site formation processes at the site. Initial deposition is characterized by local reworking of marine shelly sands dating to Marine Isotopic Stage 5e (MIS5e). The subsequent stratification reveals sedimentary dynamics predominantly associated with gravity-driven inputs and contributions from weathering of the encasing bedrock, at the same time that anthropogenic sediments were being accumulated. The allochthonous components reflect soil degradation and vegetation changes around the cave during the last interglacial. Human occupations seems to be somewhat ephemeral in nature, with some stratigraphic units apparently lacking archaeological components, while in others the human-associated deposits (e.g., burned bones, charcoal, and ashes) can be substantial. Ephemeral breaks in sedimentation and/or erosion followed by stabilization are mainly discernible microscopically by the presence of phosphatic-rich laminae interpreted as short-lived surfaces, peaks of increased humidity and colonization by plants. More substantial erosion affects the uppermost Aterian layers, presumably due to localized reconfigurations of the cave's roof. The subsequent Iberomaurusian deposits are not in their primary position and are associated with well-sorted silts of aeolian origin. While the effects of chemical diagenesis are limited throughout the whole stratigraphic sequence, physical bioturbation (e.g., by wasps, rodents, and earthworms) is more pervasive and leads to localized movement of the original sedimentary particles. PMID:24650737

  3. Space Weathering of Apollo 16 Sample 62255: Lunar Rocks as Witness Plates for Deciphering Regolith Formation Processes

    NASA Technical Reports Server (NTRS)

    Wentworth, S. J.; McKay, D. S.; Keller, L. P.

    2004-01-01

    Space weathering, or alteration that occurs at the surfaces of materials exposed directly to space, has been one of the primary areas of focus of lunar studies for the past several years. It is caused by processes such as micrometeorite impacts and solar wind bombardment, and effects can include microcraters, spall zones, and vapor deposits. Much of the recent work on space weathering has been concentrated on nanoscale features, especially the amorphous rims commonly found on individual lunar soil grains. The rims typically contain nanophase Fe metal globules, which, along with Fe metal globules in agglutinates, have a profound effect on optical properties of lunar soils. The nanophase metallic iron globules cause the characteristic optical changes (reddening and darkening) found in mature lunar soils.

  4. Deciphering Dynamical Patterns of Growth Processes

    ERIC Educational Resources Information Center

    Kolakowska, A.

    2009-01-01

    Large systems of statistical physics often display properties that are independent of particulars that characterize their microscopic components. Universal dynamical patterns are manifested by the presence of scaling laws, which provides a common insight into governing physics of processes as vastly diverse as, e.g., growth of geological…

  5. Deciphering the Physical Basis of Biomineralization through Investigations of Nanoscale Growth Processes

    NASA Astrophysics Data System (ADS)

    Dove, P. M.; Davis, K. J.; De Yoreo, J. J.; Orme, C. A.

    2001-12-01

    Microbes and higher organisms direct the formation of complex structures in controlled biomineralization. Using biologically mediated crystallization strategies that have evolved over millenia, organisms have developed the ability to produce nanophase structures as single crystals and composite materials with remarkable properties that fulfill specific functional needs. Modern organisms, as well as those found in the sediment and rock records, chronicle Nature's ability to synthesize sophisticated nanostructures. Although biomineral compositions and their morphologies are windows to interpreting environments of prosperity and decline, most current interpretations lack an understanding of fundamental processes. Hence, the physical basis of biological mineralization continues as one of Nature's best kept secrets. Recently, the biomineralization processes of marine microorganisms have emerged as particularly important owing to the use of biomineral products as paleoclimate indicators. Besides providing critical information on crystal growth history, the minor and trace elements found in these materials also behave as impurities to regulate their properties and formation rates. Using integrated approaches, we are investigating the kinetics and thermodynamics of calcite growth to decipher mechanisms of biomineral formation. Our focus is to link molecular interactions with surface processes and nanoscale controls on crystal morphology. The molecular-scale structure of the crystalline interface is a critical growth determinant, especially when considering nanocrystalline phases. By combining in situ AFM studies of growth that use carefully characterized solution chemistries with molecular modeling and surface spectroscopic investigations, we couple observations of nanoscale growth mechanisms with quantitative kinetic and thermodynamic information. This approach is showing how key inorganic growth impurities, Mg2+ and Sr2+, affect mineralization through complex ion

  6. Geochemistry of the Neoproterozoic Johnnie Formation and Stirling Quartzite, southern Nopah Range, California: Deciphering the roles of climate, tectonics, and sedimentary process in reconstructing the early evolution of a rifted continental margin

    NASA Astrophysics Data System (ADS)

    Schoenborn, William A.

    The Neoproterozoic Stirling Quartzite and Johnnie Formation in the southern Nopah Range, southeastern California, comprise a thick sequence of predominantly siliciclastic sediment that is exposed along the Cordilleran margin. Located above the syn-rift Kingston Peak Formation, they mark the early deposits of passive margin sedimentation during the breakup of the Rodinia supercontinent. Disagreement exists between field-based observations and subsidence modeling as to whether these units represent rift or passive margin deposition. In this study, major-, trace-, and rare earth--element (REE) geochemistry, and U-Pb detrital zircon geochronology are used to determine their provenance, paleoclimatic information, and, consequently their paleotectonic setting. Geochemical and petrologic evidence confirm that Johnnie Formation mudstones and sandstones were the initial siliciclastic deposits laid along the Cordilleran Laurentian margin following the Neoproterozoic break-up of Rodinia. Johnnie Formation sediment has corrected CIA values between 63 and 83, and likely higher, which suggests moderate to intense weathering of the source. Modeling suggests the unweathered source likely possessed a composition of a 90% granodiorite + 10% high-K granite. This mixture balances petrographic observations, major element geochemistry, and the REE: (La/Sm)N = 4.19 +/- 1.26, (Gd/Yb)N = 1.34 +/- 0.38, Eu/Eu* = 0.63 +/- 0.09 and (La/Yb)N = 9.55 +/- 2.27. The hypothesis of a primary tectonic control on sediment composition (i.e. rift-basin deposition) is rejected because Johnnie Formation sediments largely lack lithic fragments that are indicative of derivation from a source area with rugged topography. Feldspars are distributed unevenly in finer grained sediments. Observed fluctuations in feldspar content of sediments from the lower to upper Johnnie Formation are attributed to increased abrasion and hydrodynamic sorting, which differentially segregated feldspars into finer grained

  7. Deciphering How Pore Formation Causes Strain-Induced Membrane Lysis of Lipid Vesicles.

    PubMed

    Jackman, Joshua A; Goh, Haw Zan; Zhdanov, Vladimir P; Knoll, Wolfgang; Cho, Nam-Joon

    2016-02-01

    Pore formation by membrane-active antimicrobial peptides is a classic strategy of pathogen inactivation through disruption of membrane biochemical gradients. It remains unknown why some membrane-active peptides also inhibit enveloped viruses, which do not depend on biochemical gradients. Here, we employ a label-free biosensing approach based on simultaneous quartz crystal microbalance-dissipation and ellipsometry measurements in order to investigate how a pore-forming, virucidal peptide destabilizes lipid vesicles in a surface-based experimental configuration. A key advantage of the approach is that it enables direct kinetic measurement of the surface-bound peptide-to-lipid (P:L) ratio. Comprehensive experiments involving different bulk peptide concentrations and biologically relevant membrane compositions support a unified model that membrane lysis occurs at or above a critical P:L ratio, which is at least several-fold greater than the value corresponding to the onset of pore formation. That is consistent with peptide-induced pores causing additional membrane strain that leads to lysis of highly curved membranes. Collectively, the work presents a new model that describes how peptide-induced pores may destabilize lipid membranes through a membrane strain-related lytic process, and this knowledge has important implications for the design and application of membrane-active peptides. PMID:26751083

  8. Quantitative Proteomic and Phosphoproteomic Approaches for Deciphering the Signaling Pathway for Tension Wood Formation in Poplar.

    PubMed

    Mauriat, Mélanie; Leplé, Jean-Charles; Claverol, Stéphane; Bartholomé, Jérôme; Negroni, Luc; Richet, Nicolas; Lalanne, Céline; Bonneu, Marc; Coutand, Catherine; Plomion, Christophe

    2015-08-01

    Trees adjust their growth following forced changes in orientation to re-establish a vertical position. In angiosperms, this adjustment involves the differential regulation of vascular cambial activity between the lower (opposite wood) and upper (tension wood) sides of the leaning stem. We investigated the molecular mechanisms leading to the formation of differential wood types through a quantitative proteomic and phosphoproteomic analysis on poplar subjected to a gravitropic stimulus. We identified and quantified 675 phosphopeptides, corresponding to 468 phosphoproteins, and 3 763 nonphosphorylated peptides, corresponding to 1 155 proteins, in the differentiating xylem of straight-growing trees (control) and trees subjected to a gravitational stimulus during 8 weeks. About 1% of the peptides were specific to a wood type (straight, opposite, or tension wood). Proteins quantified in more than one type of wood were more numerous: a mixed linear model showed 389 phosphopeptides and 556 proteins to differ in abundance between tension wood and opposite wood. Twenty-one percent of the phosphoproteins identified here were described in their phosphorylated form for the first time. Our analyses revealed remarkable developmental molecular plasticity, with wood type-specific phosphorylation events, and highlighted the involvement of different proteins in the biosynthesis of cell wall components during the formation of the three types of wood. PMID:26112267

  9. An interdisciplinary approach to decipher different phases of soil formation using root abundances and geochemical methods

    NASA Astrophysics Data System (ADS)

    Wiesenberg, Guido; Gocke, Martina

    2015-04-01

    Pedogenic processes are commonly thought to be restricted mainly to the uppermost few dm of soils. However, often processes like water infiltration and - more obviously - rooting lead to much deeper penetration of soil, soil parent material and, if present, paleosols. The extent to which root penetration and subsequent organic matter incorporation, release of root exudates and microbial activity influence the general chemical and physical properties of deeper soil horizons remains largely unknown. We determined the lateral extent of root-derived overprint of the soil parent material as well as the overprint of the chemical properties in paleosols by combining root quantities obtained in the field with a large variety of inorganic and organic chemical as well as microbial properties in bulk soils and rhizosphere samples. Soils, soil parent material and paleosols were sampled along a transect from The Netherlands via Germany and Hungary towards Serbia, where soil and underlying loess, sand, and paleosol profiles were excavated in pits of 2 m to 13 m depth. Root counting on horizontal levels and profile walls during field campaigns, assisted by three-dimensional X-ray microtomographic scanning of undisturbed samples, enabled the quantitative assessment of recent and ancient root systems. Ages were determined by 14C dating for the latter, and by OSL dating for sediments, respectively. The bulk elemental composition of soils, sediments and paleosols and molecular structure of organic matter therein helped to quantitatively assess the root-related overprint in different depth intervals. The results point to the significance of deep roots as a soil forming factor extending into soil parent material, as well as the overprint of geochemical proxies in paleosols due to intense root penetration at various phases after burial. The shown examples highlight potential pitfalls in assessing rooted soil and paleosol profiles and their ages, and provide potential solutions for

  10. Deciphering the molecular and biologic processes that mediate histone deacetylase inhibitor-induced thrombocytopenia.

    PubMed

    Bishton, Mark J; Harrison, Simon J; Martin, Benjamin P; McLaughlin, Nicole; James, Chloé; Josefsson, Emma C; Henley, Katya J; Kile, Benjamin T; Prince, H Miles; Johnstone, Ricky W

    2011-03-31

    Histone deacetylase inhibitor (HDACI)-induced thrombocytopenia (TCP) is a major dose-limiting toxicity of this new class of drugs. Using preclinical models to study the molecular and biologic events that underpin this effect of HDACI, we found that C57BL/6 mice treated with both the HDAC1/2-selective HDACI romidepsin and the pan-HDACI panobinostat developed significant TCP. HDACI-induced TCP was not due to myelosuppression or reduced platelet lifespan, but to decreased platelet release from megakaryocytes. Cultured primary murine megakaryocytes showed reductions in proplatelet extensions after HDACI exposure and a dose-dependent increase in the phosphorylation of myosin light chain 2 (MLC2). Phosphorylation of MLC to phospho-MLC (pMLC) and subsequent proplatelet formation in megakaryocytes is regulated by the Rho-GTPase proteins Rac1, CDC42, and RhoA. Primary mouse megakaryocytes and the human megakaryoblastic cell line Meg-01 showed reductions in Rac1, CDC42, and RhoA protein levels after treatment with HDACIs. We were able to overcome HDACI-induced TCP by administering the mouse-specific thrombopoietin (TPO) mimetic AMP-4, which improved platelet numbers to levels similar to untreated controls. Our report provides the first detailed account of the molecular and biologic processes involved in HDACI-mediated TCP. Moreover, our preclinical studies provide evidence that dose-limiting TCP induced by HDACIs may be circumvented using a TPO mimetic. PMID:21292776

  11. Prominence Formation Processes

    NASA Astrophysics Data System (ADS)

    Welsch, B. T.; DeVore, C. R.; Antiochos, S. K.

    2005-01-01

    Martens and Zwaan (ApJ v. 558 872) have proposed a prominence/ filament formation model in which differential rotation drives reconnection between two initially unconnected active regions to form helical field lines that support mass and are held down by overlying field. Using an MHD solver with adaptive refinement we simulated this process by imposing a shear flow meant to mimic differential rotation on two bipolar flux distributions meant to mimic distinct active regions. In some runs the flux systems are initially potential while in others they have been twisted by footpoint rotation to inject helicity prior to imposing the shear flow. The resulting structures are studied to understand the role of helicity in the formation of prominence-like structures.

  12. Deciphering the Role of Surface and Subsurface Processes on Solute Dynamics at the Catchment Scale

    NASA Astrophysics Data System (ADS)

    Scanlon, T. M.; Riscassi, A. L.; Ingram, S. M.

    2008-12-01

    Nitrate (NO3-) leakage from forested watersheds due to disturbance is a well-documented but not well- understood process that can contribute to the degradation of receiving waters through eutrophication. Several studies have shown large-scale defoliation events in small forested watersheds in the Eastern U.S. cause immediate and dramatic increases in NO3- flux to steams with large differences in recovery time. Here, we analyze water-quality and discharge data collected from the time period 1992-2004 following a large-scale gypsy moth defoliation in Shenandoah National Park, Virginia. Following the defoliation, groundwater NO3- concentrations declined exponentially with a distinct seasonal pattern. Initial NO3- groundwater concentrations were related to the magnitude of defoliation within each watershed. Surprisingly, no long-term trend or seasonal pattern were found for soil water NO3- concentrations, as inferred from a mixing model applied to individual storm events. By comparing decay constants associated with groundwater discharge with constants for nitrate recovery to background concentrations, we find a hydrological imprint on the recovery time. This was confirmed by performing similar analysis on data from Hubbard Brook and Coweeta, where more rapid recovery times are attributed to the distinct biogeochemical processes associated with deforestation or crown damage. Synoptic measurements of NO3- concentrations collected on eight occasions within a stream network during the period of recovery are used to fit a model designed to capture the observed spatial variability. We find that upland terrestrial processes, rather than in-stream processes, account for the greatest proportion of this variability.

  13. Deciphering seismic signatures of physical processes in dynamic complex systems: an experimental approach

    NASA Astrophysics Data System (ADS)

    Arciniega-Ceballos, A.; Alatorre-Ibarguengoitia, M. A.; Perton, M.; Sanchez-Sesma, F. J.; Dingwell, D. B.

    2012-12-01

    Seismic evaluation of well-controlled experimental simulations of volumetric sources (e.g. explosions, cavitations, burst, pressure drops) is a powerful tool for better understanding of the seismic wave field of complex systems. In this work, we describe two distinct well-constrained physical models, which under controlled laboratory conditions enable the simulation of complex systems; volcanic explosions and fluid-filled wells. For volcanic explosion simulations, several experiments were performed to study seismic signals associated with fragmentation processes of volcanic rocks by rapid decompression. These experiments were performed in a shock-tube apparatus at room temperature and a pressure range of 4 to 20 MPa. Pumice samples from Popocatepetl volcano of different porosity were studied. To investigate the elastic wave propagation inside a fluid-filled well, we present a hollow cylinder model surrounded by water, excited by a ultrasonic laser beam emitting pulses between 5 and 8 ns in duration, causing micro-cavitations. Adequate instrumentation of these mechanical systems, using high-precision sensors, enabled us to capture and to analyze seismic wave fields, characterizing also their source mechanism. Although these laboratory analogues have simplified geometries and media properties, these experimental investigations are based upon the hypothesis that, in comparable systems, any physical process (e.g. pressure drops, fragmentation, vibration, elastic deformation, etc) conducts to equivalent system responses, causing the same distinctive effects, which are independent on the scale. These effects engender particular seismic signatures, reflecting the dynamics of the process, and are comparable with numerical simulations and seismic field observations. Therefore, laboratory models can validate the inverse problem solution, indicating that the source mechanism and the system nature can both be inferred from field-based seismograms.

  14. Deciphering the photochemical mechanisms describing the UV-induced processes occurring in solvated guanine monophosphate

    NASA Astrophysics Data System (ADS)

    Altavilla, Salvatore; Segarra-Martí, Javier; Nenov, Artur; Conti, Irene; Rivalta, Ivan; Garavelli, Marco

    2015-04-01

    The photophysics and photochemistry of water-solvated guanine monophosphate (GMP) are here characterized by means of a multireference quantum-chemical/molecular mechanics theoretical approach (CASPT2//CASSCF/AMBER) in order to elucidate the main photo-processes occurring upon UV-light irradiation. The effect of the solvent and of the phosphate group on the energetics and structural features of this system are evaluated for the first time employing high-level ab initio methods and thoroughly compared to those in vacuo previously reported in the literature and to the experimental evidence to assess to which extent they influence the photoinduced mechanisms. Solvated electronic excitation energies of solvated GMP at the Franck-Condon (FC) region show a red shift for the ππ* La and Lb states, whereas the energy of the oxygen lone-pair nπ* state is blue-shifted. The main photoinduced decay route is promoted through a ring-puckering motion along the bright lowest-lying La state towards a conical intersection (CI) with the ground state, involving a very shallow stationary point along the minimum energy pathway in contrast to the barrierless profile found in gas-phase, the point being placed at the end of the minimum energy path (MEP) thus endorsing its ultrafast deactivation in accordance with time-resolved transient and photoelectron spectroscopy experiments. The role of the nπ* state in the solvated system is severely diminished as the crossings with the initially populated La state and also with the Lb state are placed too high energetically to partake prominently in the deactivation photo-process. The proposed mechanism present in solvated and in vacuo DNA/RNA chromophores validates the intrinsic photostability mechanism through CI-mediated non-radiative processes accompanying the bright excited-state population towards the ground state and subsequent relaxation back to the FC region.

  15. Deciphering and modeling interconnections in ecohydrology: The role of scale, thresholds and stochastic storage processes

    NASA Astrophysics Data System (ADS)

    Bartlett, M. S.; McDonnell, J. J.; Porporato, A. M.

    2013-12-01

    Several components of ecohydrological systems are characterized by an interplay of stochastic inputs, finite capacity storage, and nonlinear, threshold-like losses, resulting in a complex partitioning of the rainfall input between the different basin scales. With the goal of more accurate predictions of rainfall partitioning and threshold effects in ecohydrology, we examine ecohydrological processes at the various scales, including canopy interception, soil storage with runoff/percolation, hillslope filling-spilling mechanisms, and the related groundwater recharge and baseflow contribution to streamflow. We apply a probabilistic approach to a hierarchical arrangement of cascading reservoirs that are representative of the components of the basin system. The analytical results of this framework help single out the key parameters controlling the partitioning of rainfall within the storage compartments of river basins. This theoretical framework is a useful learning tool for exploring the physical meaning of known thresholds in ecohydrology.

  16. What Controls the Sizes and Shapes of Volcanic Ash? Integrating Morphological, Textural and Geochemical Ash Properties to Decipher Eruptive Processes

    NASA Astrophysics Data System (ADS)

    Liu, E. J.; Cashman, K. V.; Rust, A.

    2015-12-01

    Volcanic ash particles encompass a diverse spectrum of shapes as a consequence of differences in the magma properties and the magma ascent and eruption conditions. We show how the quantitative analysis of ash particle shapes can be a valuable tool for deciphering magma fragmentation and transport processes. Importantly, integrating morphological data with ash texture (e.g. bubble and crystal sizes) and dissolved volatile data provides valuable insights into the physical and chemical controls on the resulting ash deposit. To explore the influence of magma-water interaction (MWI) on fine ash generation, we apply this multi-component characterisation to tephra from the 2500BC Hverfjall Fires, Iceland. Here, coeval fissure vents spanned sub-aerial to shallow lacustrine environments. Differences in the size and morphology of pyroclasts thus reflect fragmentation mechanisms under different near-surface conditions. Using shape parameters sensitive to both particle roughness and internal vesicularity, we quantify the relative proportions of dense fragments, bubble shards, and vesicular grains from 2-D SEM images. We show that componentry (and particle morphology) varies as a function of grain size, and that this variation can be related back to the bubble size distribution. Although both magmatic and hydromagmatic deposits exhibit similar component assemblages, they differ in how these assemblages change with grain size. These results highlight the benefits of characterising ash deposits over a wide range of grain sizes, and caution against inferring fragmentation mechanism from a narrow grain size range. Elevated matrix glass S concentrations in hydromagmatic ash (600-1500 ppm) compared to those in magmatic ash and scoria lapilli (200-500 ppm) indicate interrupted vesiculation. In contrast to the subaerial 'dry' deposits, fragmentation during MWI likely occurred over a greater range of depths with quench rates sufficient to prevent post-fragmentation degassing. High

  17. The Permian Whitehill Formation (Karoo Basin, South Africa): deciphering the complexity and potential of an unconventional gas resource

    NASA Astrophysics Data System (ADS)

    Götz, Annette E.

    2014-05-01

    A key energy policy objective of the South African government is to diversify its energy mix from coal which constitutes 85% of the current mix. Gas will play a key role in the future South African economy with demand coming from electricity generation and gas-to-liquids projects. A study on world shale reserves conducted by the Energy Information Agency (EIA) in 2011 concluded that there could be as much as 485 Tcf recoverable reserves of shale gas in the South African Karoo Basin. However, the true extent and commercial viability is still unknown, due to the lack of exploration drilling and modern 3D seismic. The present study compiles existing data from literature review and new data from outcrop analogue studies on the Permian Whitehill Formation, the main target formation for future shale gas production, including thickness, depth, maturity, TOC, lithologies, sedimentary and organic facies, and dolerite occurrence to provide a first reference dataset for further investigations and resource estimates.

  18. Dissipative processes in galaxy formation.

    PubMed Central

    Silk, J

    1993-01-01

    A galaxy commences its life in a diffuse gas cloud that evolves into a predominantly stellar aggregation. Considerable dissipation of gravitational binding energy occurs during this transition. I review here the dissipative processes that determine the critical scales of luminous galaxies and the generation of their morphology. The universal scaling relations for spirals and ellipticals are shown to be sensitive to the history of star formation. Semiphenomenological expressions are given for star-formation rates in protogalaxies and in starbursts. Implications are described for elliptical galaxy formation and for the evolution of disk galaxies. PMID:11607396

  19. Deciphering Timescales and Mechanisms of Mineral Reactions During Exhumation Processes Using Element Zoning in Exsolution Lamellae in a Garnet Pyroxenite From the Granulitgebirge in Saxony, Germany

    NASA Astrophysics Data System (ADS)

    Muller, T.; Massonne, H.; Willner, A. P.

    2013-12-01

    The chemical composition of a solid-solution phase is a function of external (intensive) variables, such as temperature and/or pressure. Hence, the dynamic nature of many geological processes such as subduction or exhumation leads to the adjustment of the mineral composition which is typically used for geothermobarometry. The change of chemical composition, however, requires mass transport of major and trace elements, which is often kinetically controlled. As a result, incomplete equilibration is preserved as element zoning in the mineral. In addition, mineral growth itself is often controlled by transport properties of elements and can thus likewise produce a zoning pattern containing information on the growth mechanism and time. Unraveling such zoning patterns combined with geothermobarometry is thus the key tool to decipher the origin and evolution of a mineral along a P-T-t-path. In this study we present data of a garnet pyroxenite from the Granulitgebirge, Germany. The rock contains remarkable exsolution textures from former megacrysts that produced up to mm-wide, alternating lamellae of garnet (grt) and clinopyroxene (cpx). Based on textural observations it is impossible to identify whether the precursor megacryst was a majoritic garnet or an Al-rich clinopyroxene. Compositional profiles of major and trace elements measured with the electron microprobe perpendicular to the grt-cpx interfaces reveal systematic zoning patterns for Fe, Mg, Al, Si, Cr, Ti in cpx and Ca, Fe, Mg, Mn in grt. We combine thermodynamic data with a numerical finite difference scheme that simulates growth and simultaneous diffusive exchange between grt and cpx along a virtual cooling path. The model assumes local equilibrium at the interface and diffusive fluxes are constrained by mass balance. It is shown that some zoning patterns such as Fe-Mg exchange between grt and cpx can be used to extract cooling rates and thus timescales of exhumation, while other profiles, such as Ca, Al, and

  20. Rapid gas hydrate formation process

    SciTech Connect

    Brown, Thomas D.; Taylor, Charles E.; Unione, Alfred J.

    2013-01-15

    The disclosure provides a method and apparatus for forming gas hydrates from a two-phase mixture of water and a hydrate forming gas. The two-phase mixture is created in a mixing zone which may be wholly included within the body of a spray nozzle. The two-phase mixture is subsequently sprayed into a reaction zone, where the reaction zone is under pressure and temperature conditions suitable for formation of the gas hydrate. The reaction zone pressure is less than the mixing zone pressure so that expansion of the hydrate-forming gas in the mixture provides a degree of cooling by the Joule-Thompson effect and provides more intimate mixing between the water and the hydrate-forming gas. The result of the process is the formation of gas hydrates continuously and with a greatly reduced induction time. An apparatus for conduct of the method is further provided.

  1. A computer-assisted thin-section study of Lake Baikal sediments: a tool for understanding sedimentary processes and deciphering their climatic signal

    NASA Astrophysics Data System (ADS)

    Francus, Pierre; Karabanov, Eugene

    A freeze-drying technique for cutting thin-sections of soft sediments without disturbance is used to study several Lake Baikal sedimentary microstructures. Image analysis methodology is applied to selected thin-sections. This new technique provides quantification of the size, shape, orientation and packing of the objects forming the sedimentary structures. Sedimentary processes, which were previously poorly documented, have been identified, and others are better understood. Spheroidal lens-like pure aggregates of the diatom genus Synedra are found in hemipelagic sediments, providing a new insight into their traditional paleoecological interpretation. They are possibly related to a transportation mechanism from the littoral zone or to lacustrine snow. Laminae of Aulacoseira have also been recorded. Evidence of rapid sedimentation suggests they are due to massive algal blooms. The depositional mechanism that was suggested by other studies for explaining the laminations at the Buguldeika uplift is confirmed: the hemipelagic sedimentation is interrupted by terrigenous pulses due to discharge events. The sedimentation rate appears to be increasing during these pulses. Preliminary results from the Academician Ridge show stronger microbioturbation during cold periods. This observation strengthens the hypothesis of intense water circulation during colder times. Thin-section image analysis provides crucial information for deciphering lacustrine records and their regional and palaeoclimatic significance.

  2. Processes and problems in secondary star formation

    SciTech Connect

    Klein, R.I.; Whitaker, R.W.; Sandford M.T. II

    1984-03-01

    Recent developments relating the conditions in molecular clouds to star formation triggered by a prior stellar generation are reviewed. Primary processes are those that lead to the formation of a first stellar generation. The secondary processes that produce stars in response to effects caused by existing stars are compared and evaluated in terms of the observational data presently available. We discuss the role of turbulence to produce clumpy cloud structures and introduce new work on colliding inter-cloud gas flows leading to non-linear inhomogeneous cloud structures in an intially smooth cloud. This clumpy morphology has important consequences for secondary formation. The triggering processes of supernovae, stellar winds, and H II regions are discussed with emphasis on the consequences for radiation driven implosion as a promising secondary star formation mechanism. Detailed two-dimensional, radiation-hydrodynamic calculations of radiation driven implosion are discussed. This mechanism is shown to be highly efficient in synchronizing the formation of new stars in congruent to 1-3 x 10/sup 4/ years and could account for the recent evidence for new massive star formation in several UCHII regions. It is concluded that, while no single theory adequately explains the variety of star formation observed, a uniform description of star formation is likely to involve several secondary processes. Advances in the theory of star formation will require multiple dimensional calculations of coupled processes. The important non-linear interactions include hydrodynamics, radiation transport, and magnetic fields.

  3. Process for recovering oil from subterranean formations

    SciTech Connect

    Volz, H.; Schnepel, F.M.

    1986-05-20

    A process is described for reducing the loss of relatively high molecular weight polymers to a subterranean formation containing high salinity connate water during an enhanced oil recovery operation in a formation penetrated by at least one injection well and at least one production well, which comprises: injecting into the formation a sacrificial agent in solution selected from the group consisting of polyethylene glycol, polypropylene glycol, a mixture of polyethylene glycol and polypropylene glycol, and ethylene oxide/propylene oxide copolymer; the sacrificial agent having an average molecular weight between about 600 and about 1200.

  4. Instabilities and structure formation in laser processing

    SciTech Connect

    Baeuerle, D.; Arenholz, E.; Arnold, N.; Heitz, J.; Kargl, P.B.

    1996-12-31

    This paper gives an overview on different types of instabilities and structure formation in various fields of laser processing. Among the examples discussed in detail are non-coherent structures observed in laser-induced chemical vapor deposition (LCVD), in laser-induced surface modifications, and in laser ablation of polymers.

  5. Bistatic SAR: Signal Processing and Image Formation.

    SciTech Connect

    Wahl, Daniel E.; Yocky, David A.

    2014-10-01

    This report describes the significant processing steps that were used to take the raw recorded digitized signals from the bistatic synthetic aperture RADAR (SAR) hardware built for the NCNS Bistatic SAR project to a final bistatic SAR image. In general, the process steps herein are applicable to bistatic SAR signals that include the direct-path signal and the reflected signal. The steps include preprocessing steps, data extraction to for a phase history, and finally, image format. Various plots and values will be shown at most steps to illustrate the processing for a bistatic COSMO SkyMed collection gathered on June 10, 2013 on Kirtland Air Force Base, New Mexico.

  6. Grain processes in massive star formation

    NASA Technical Reports Server (NTRS)

    Wolfire, M. G.; Cassinelli, J. P.

    1986-01-01

    Observational evidence suggests that stars greater than 100 M(solar) exist in the Galaxy and Large Magellanic Cloud (LMC), however classical star formation theory predicts stellar mass limits of only approx. 60 M(solar). A protostellar accretion flow consists of inflowing gas and dust. Grains are destroyed as they are near the central protostar creating a dust shell or cocoon. Radiation pressure acting on the grain can halt the inflow of material thereby limiting the amount of mass accumulated by the protostar. We first consider rather general constraints on the initial grain to gas ratio and mass accretion rates that permit inflow. We further constrain these results by constructing a numerical model. Radiative deceleration of grains and grain destruction processes are explicitly accounted for in an iterative solution of the radiation-hydrodynamic equations. Findings seem to suggest that star formation by spherical accretion requires rather extreme preconditioning of the grain and gas environment.

  7. Oligosaccharide formation during commercial pear juice processing.

    PubMed

    Willems, Jamie L; Low, Nicholas H

    2016-08-01

    The effect of enzyme treatment and processing on the oligosaccharide profile of commercial pear juice samples was examined by high performance anion exchange chromatography with pulsed amperometric detection and capillary gas chromatography with flame ionization detection. Industrial samples representing the major stages of processing produced with various commercial enzyme preparations were studied. Through the use of commercially available standards and laboratory scale enzymatic hydrolysis of pectin, starch and xyloglucan; galacturonic acid oligomers, glucose oligomers (e.g., maltose and cellotriose) and isoprimeverose were identified as being formed during pear juice production. It was found that the majority of polysaccharide hydrolysis and oligosaccharide formation occurred during enzymatic treatment at the pear mashing stage and that the remaining processing steps had minimal impact on the carbohydrate-based chromatographic profile of pear juice. Also, all commercial enzyme preparations and conditions (time and temperature) studied produced similar carbohydrate-based chromatographic profiles. PMID:26988479

  8. Facilitating collaboration in rare genetic disorders through effective matchmaking in DECIPHER.

    PubMed

    Chatzimichali, Eleni A; Brent, Simon; Hutton, Benjamin; Perrett, Daniel; Wright, Caroline F; Bevan, Andrew P; Hurles, Matthew E; Firth, Helen V; Swaminathan, Ganesh J

    2015-10-01

    DECIPHER (https://decipher.sanger.ac.uk) is a web-based platform for secure deposition, analysis, and sharing of plausibly pathogenic genomic variants from well-phenotyped patients suffering from genetic disorders. DECIPHER aids clinical interpretation of these rare sequence and copy-number variants by providing tools for variant analysis and identification of other patients exhibiting similar genotype-phenotype characteristics. DECIPHER also provides mechanisms to encourage collaboration among a global community of clinical centers and researchers, as well as exchange of information between clinicians and researchers within a consortium, to accelerate discovery and diagnosis. DECIPHER has contributed to matchmaking efforts by enabling the global clinical genetics community to identify many previously undiagnosed syndromes and new disease genes, and has facilitated the publication of over 700 peer-reviewed scientific publications since 2004. At the time of writing, DECIPHER contains anonymized data from ∼250 registered centers on more than 51,500 patients (∼18000 patients with consent for data sharing and ∼25000 anonymized records shared privately). In this paper, we describe salient features of the platform, with special emphasis on the tools and processes that aid interpretation, sharing, and effective matchmaking with other data held in the database and that make DECIPHER an invaluable clinical and research resource. PMID:26220709

  9. Facilitating Collaboration in Rare Genetic Disorders Through Effective Matchmaking in DECIPHER

    PubMed Central

    Chatzimichali, Eleni A.; Brent, Simon; Hutton, Benjamin; Perrett, Daniel; Wright, Caroline F.; Bevan, Andrew P.; Hurles, Matthew E.; Firth, Helen V.

    2015-01-01

    ABSTRACT DECIPHER (https://decipher.sanger.ac.uk) is a web‐based platform for secure deposition, analysis, and sharing of plausibly pathogenic genomic variants from well‐phenotyped patients suffering from genetic disorders. DECIPHER aids clinical interpretation of these rare sequence and copy‐number variants by providing tools for variant analysis and identification of other patients exhibiting similar genotype–phenotype characteristics. DECIPHER also provides mechanisms to encourage collaboration among a global community of clinical centers and researchers, as well as exchange of information between clinicians and researchers within a consortium, to accelerate discovery and diagnosis. DECIPHER has contributed to matchmaking efforts by enabling the global clinical genetics community to identify many previously undiagnosed syndromes and new disease genes, and has facilitated the publication of over 700 peer‐reviewed scientific publications since 2004. At the time of writing, DECIPHER contains anonymized data from ∼250 registered centers on more than 51,500 patients (∼18000 patients with consent for data sharing and ∼25000 anonymized records shared privately). In this paper, we describe salient features of the platform, with special emphasis on the tools and processes that aid interpretation, sharing, and effective matchmaking with other data held in the database and that make DECIPHER an invaluable clinical and research resource. PMID:26220709

  10. Towards successful OSL sampling strategies in glacial environments: deciphering the influence of depositional processes on bleaching of modern glacial sediments from Jostedalen, Southern Norway

    NASA Astrophysics Data System (ADS)

    King, G. E.; Robinson, R. A. J.; Finch, A. A.

    2014-04-01

    The optically stimulated luminescence (OSL) signals of quartz and K-feldspar are known to bleach poorly within some glacial settings, and can present a major challenge to dating applications. However, because the OSL signal is extremely sensitive to sunlight exposure history, the residual luminescence signals of modern glacial sediments also encode information about transport and depositional processes. Through examination of the residual luminescence properties (equivalent dose (De) and overdispersion values) of a suite of modern glacial sediments from different depositional settings (sandar, proglacial delta and main meltwater channel), this study provides insights not only into which sediments are likely to be fully bleached within glacial settings, but also into how OSL can be used to trace different depositional processes across sedimentary landforms. Improved understanding of the processes of sediment bleaching will enable better sample selection and may improve the accuracy and precision of OSL dating of glacial sediments.

  11. Situ microbial plugging process for subterranean formations

    DOEpatents

    McInerney, Michael J.; Jenneman, Gary E.; Knapp, Roy M.; Menzie, Donald E.

    1985-12-17

    Subterranean paths of water flow are impeded or changed by the facilitation of microbial growth therein. Either indigenous bacterial growth may be stimulated with nutrients or the formation may be first seeded with bacteria or their spores which inhibit fluid flow after proliferation. These methods and bacteria are usable to alter the flow of water in a waterflooded oil formation and to impede the outflow of contaminated water.

  12. Bio-orthogonally Deciphered Binary Nanoemitters for Tumor Diagnostics.

    PubMed

    An, Hong-Wei; Qiao, Sheng-Lin; Li, Li-Li; Yang, Chao; Lin, Yao-Xin; Wang, Yi; Qiao, Zeng-Ying; Wang, Lei; Wang, Hao

    2016-08-01

    Bioinspired design concept has been recognized as one of the most promising strategies for discovering new biomaterials. However, smart biomaterials that are of growing interests in biomedical field need biological processability to meet their emergent applications in vivo. Herein, a new bio-orthogonally deciphered approach has been demonstrated for modulating optical properties of nanomaterials in living systems. The self-assembled nanoemitters based on cyanine-pyrene molecule 1 with inert optical property are designed and prepared. The structure and optical feature of the nanoemitters 1 can be efficiently and reliably modulated by a unique bio-orthogonal mechanism with abundant glutathione (GSH) as an activator. As a result, the self-assembled nanoemitters 1 spontaneously exhibits binary emissions for high-performance tumor imaging in vivo. We believe that this bio-orthogonally deciphered strategy opens a new avenue for designing variable smart biomaterials or devices in biomedical applications. PMID:27434548

  13. Adaptation Processes in Chinese: Word Formation.

    ERIC Educational Resources Information Center

    Pasierbsky, Fritz

    The typical pattern of Chinese word formation is to have native material adapt to changed circumstances. The Chinese language neither borrows nor lends words, but it does occasionally borrow concepts. The larger cultural pattern in which this occurs is that the Chinese culture borrows, if necessary, but ensures that the act of borrowing does not…

  14. Mathematical modeling of biomass fuels formation process

    SciTech Connect

    Gaska, Krzysztof Wandrasz, Andrzej J.

    2008-07-01

    The increasing demand for thermal and electric energy in many branches of industry and municipal management accounts for a drastic diminishing of natural resources (fossil fuels). Meanwhile, in numerous technical processes, a huge mass of wastes is produced. A segregated and converted combustible fraction of the wastes, with relatively high calorific value, may be used as a component of formed fuels. The utilization of the formed fuel components from segregated groups of waste in associated processes of co-combustion with conventional fuels causes significant savings resulting from partial replacement of fossil fuels, and reduction of environmental pollution resulting directly from the limitation of waste migration to the environment (soil, atmospheric air, surface and underground water). The realization of technological processes with the utilization of formed fuel in associated thermal systems should be qualified by technical criteria, which means that elementary processes as well as factors of sustainable development, from a global viewpoint, must not be disturbed. The utilization of post-process waste should be preceded by detailed technical, ecological and economic analyses. In order to optimize the mixing process of fuel components, a mathematical model of the forming process was created. The model is defined as a group of data structures which uniquely identify a real process and conversion of this data in algorithms based on a problem of linear programming. The paper also presents the optimization of parameters in the process of forming fuels using a modified simplex algorithm with a polynomial worktime. This model is a datum-point in the numerical modeling of real processes, allowing a precise determination of the optimal elementary composition of formed fuels components, with assumed constraints and decision variables of the task.

  15. Physical processes causing the formation of penitentes.

    PubMed

    Claudin, P; Jarry, H; Vignoles, G; Plapp, M; Andreotti, B

    2015-09-01

    Snow penitentes form in sublimation conditions by differential ablation. Here we investigate the physical processes at the initial stage of penitente growth and perform the linear stability analysis of a flat surface submitted to the solar heat flux. We show that these patterns do not simply result from the self-illumination of the surface-a scale-free process-but are primarily controlled by vapor diffusion and heat conduction. The wavelength at which snow penitentes emerge is derived and discussed. We found that it is controlled by aerodynamic mixing of vapor above the ice surface. PMID:26465564

  16. Particle contamination formation in magnetron sputtering processes

    SciTech Connect

    Selwyn, G.S.; Sequeda, F.; Huang, C.

    1997-07-01

    Defects caused by particulate contamination are an important concern in the fabrication of thin film products. Often, magnetron sputtering processes are used for this purpose. Particle contamination generated during thin film processing can be detected using laser light scattering, a powerful diagnostic technique which provides real-time, {ital in situ} imaging of particles {gt}0.3 {mu}m on the target, substrate, or in the plasma. Using this technique, we demonstrate that the mechanisms for particle generation, transport, and trapping during magnetron sputter deposition are different from the mechanisms reported in previously studied plasma etch processes, due to the inherent spatial nonuniformity of magnetically enhanced plasmas. During magnetron sputter deposition, one source of particle contamination is linked to portions of the sputtering target surface exposed to weaker plasma density. There, film redeposition induces filament or nodule growth. Sputter removal of these features is inhibited by the dependence of sputter yield on angle of incidence. These features enhance trapping of plasma particles, which then increases filament growth. Eventually the growths effectively {open_quotes}short-circuit{close_quotes} the sheath, causing high currents to flow through these features. This, in turn, causes mechanical failure of the growth resulting in fracture and ejection of the target contaminants into the plasma and onto the substrate. Evidence of this effect has been observed in semiconductor fabrication and storage disk manufacturing. Discovery of this mechanism in both technologies suggests it may be universal to many sputter processes. {copyright} {ital 1997 American Vacuum Society.}

  17. Spray formation processes of impinging jet injectors

    NASA Technical Reports Server (NTRS)

    Anderson, W. E.; Ryan, H. M.; Pal, S.; Santoro, R. J.

    1993-01-01

    A study examining impinging liquid jets has been underway to determine physical mechanisms responsible for combustion instabilities in liquid bi-propellant rocket engines. Primary atomization has been identified as an important process. Measurements of atomization length, wave structure, and drop size and velocity distribution were made under various ambient conditions. Test parameters included geometric effects and flow effects. It was observed that pre-impingement jet conditions, specifically whether they were laminar or turbulent, had the major effect on primary atomization. Comparison of the measurements with results from a two dimensional linear aerodynamic stability model of a thinning, viscous sheet were made. Measured turbulent impinging jet characteristics were contrary to model predictions; the structure of waves generated near the point of jet impingement were dependent primarily on jet diameter and independent of jet velocity. It has been postulated that these impact waves are related to pressure and momentum fluctuations near the impingement region and control the eventual disintegration of the liquid sheet into ligaments. Examination of the temporal characteristics of primary atomization (ligament shedding frequency) strongly suggests that the periodic nature of primary atomization is a key process in combustion instability.

  18. Synthetic aperture radar processing with polar formatted subapertures

    SciTech Connect

    Doerry, A.W.

    1994-10-01

    Synthetic Aperture Radar (SAR) uses the motion of a small real antenna to synthesize a larger aperture, and thereby achieve very fine azimuth resolution. Efficient SAR image formation requires modelling the radar echo and compensating (focusing) the delay and phase for various positions in the target scene. Polar-Format processing is one successful algorithm developed to process large scenes at fine resolutions, but is still limited, especially at resolutions near a wavelength. This paper shows how using tiers of subapertures can overcome the limitations of Polar-Format processing and increase the focused scene size substantially while using only efficient vector multiplies and Fast Fourier Transforms.

  19. The formation process of flight crews

    NASA Technical Reports Server (NTRS)

    Ginnett, Robert C.

    1987-01-01

    A study which uses Hackman's Normative Model (1986) for group effectiveness to see if there are any differences between the behaviors of effective and less effective captains at building and maintaining their crews is presented. Captains were selected using crew evaluations, creating a final pool of six effective crew managers and four captains less proficient as crew leaders. Data collection began at crew briefings, and continued through two trips, with intense data gathering during critical incidents for both task and process events. It was found that a predetermined set of interactions that can occur between crew members exists for the forming crew. It is concluded that effective captains expand the set of interactions, decreasing the limitations on how the group will work together.

  20. Making Room for Formative Assessment Processes: A Multiple Case Study

    ERIC Educational Resources Information Center

    McEntarffer, Robert E.

    2012-01-01

    This qualitative instrumental multiple case study (Stake, 2005) explored how teachers made room for formative assessment processes in their classrooms, and how thinking about assessment changed during those formative assessment experiences. Data were gathered from six teachers over three months and included teacher interviews, student interviews,…

  1. A Process Model of Family Formation and Development

    ERIC Educational Resources Information Center

    Garland, Diana R.

    2012-01-01

    Theoretical models of family formation have assumed sexual coupling as the foundation of family life. This article proposes instead a model of family formation predicated on the processes of taking care of one another, eating together, and sharing life together. The interpersonal dynamics that distinguish a family from other close relationships…

  2. Processing treatments for mitigating acrylamide formation in sweetpotato French fries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acrylamide formation in sweetpotato French fries (SPFF) is likely a potential health concern as there is an increasing demand for good-quality fries from carotene-rich sweetpotatoes (SP). This is the first report on acrylamide formation in SPFF as affected by processing methods. Acrylamide levels in...

  3. Deciphering a neural code for vision.

    PubMed

    Passaglia, C; Dodge, F; Herzog, E; Jackson, S; Barlow, R

    1997-11-11

    Deciphering the information that eyes, ears, and other sensory organs transmit to the brain is important for understanding the neural basis of behavior. Recordings from single sensory nerve cells have yielded useful insights, but single neurons generally do not mediate behavior; networks of neurons do. Monitoring the activity of all cells in a neural network of a behaving animal, however, is not yet possible. Taking an alternative approach, we used a realistic cell-based model to compute the ensemble of neural activity generated by one sensory organ, the lateral eye of the horseshoe crab, Limulus polyphemus. We studied how the neural network of this eye encodes natural scenes by presenting to the model movies recorded with a video camera mounted above the eye of an animal that was exploring its underwater habitat. Model predictions were confirmed by simultaneously recording responses from single optic nerve fibers of the same animal. We report here that the eye transmits to the brain robust "neural images" of objects having the size, contrast, and motion of potential mates. The neural code for such objects is not found in ambiguous messages of individual optic nerve fibers but rather in patterns of coherent activity that extend over small ensembles of nerve fibers and are bound together by stimulus motion. Integrative properties of neurons in the first synaptic layer of the brain appear well suited to detecting the patterns of coherent activity. Neural coding by this relatively simple eye helps explain how horseshoe crabs find mates and may lead to a better understanding of how more complex sensory organs process information. PMID:9356504

  4. EFFECT OF SEPARATION PROCESSES ON THE FORMATION OF BROMINATED THMS

    EPA Science Inventory

    Separation treatment processes are being investigated as a way to control the formation of disinfection by-products (DBPs) in finished waters. These processes remove natural organic matter before a disinfection is applied, thus limiting the amount of material available to form D...

  5. Analysis of the Particle Formation Process of Structured Microparticles.

    PubMed

    Baldelli, Alberto; Boraey, Mohammed A; Nobes, David S; Vehring, Reinhard

    2015-08-01

    The particle formation process for microparticles of cellulose acetate butyrate dried from an acetone solution was investigated experimentally and theoretically. A monodisperse droplet chain was used to produce solution microdroplets in a size range of 55-70 μm with solution concentrations of 0.37 and 10 mg/mL. As the droplets dried in a laminar air flow with a temperature of 30, 40, or 55 °C, the particle formation process was recorded by two independent optical methods. Dried particles in a size range of 10-30 μm were collected for morphology analysis, showing hollow, elongated particles whose structure was dependent on the drying gas temperature and initial solution concentration. The setup allowed comprehensive measurements of the particle formation process to be made, including the period after initial shell formation. The early particle formation process for this system was controlled by the diffusion of cellulose acetate butyrate in the liquid phase, whereas later stages of the process were dominated by shell buckling and folding. PMID:25685865

  6. Characterisation of a laser droplet formation process by acoustic emission.

    PubMed

    Govekar, E; Klemencic, J; Kokalj, T; Jahrsdörfer, B; Muzic, P; Grabec, I

    2004-04-01

    The aim of this article is to describe an application of acoustic emission to characterise a process of laser droplet formation from a metal wire. Laser droplet formation is a crucial process in new laser droplet welding technology, where parts are joined by means of the heat content of a liquid metal droplet deposited onto the parts to be joined. A laser beam is used for heating and melting the wire tip, and for detaching the molten pendant droplet. Depending on the process parameters, three different outcomes of the process can be observed: (1) no droplet formed; (2) a droplet formed but not detached; (3) a droplet formed and detached from the wire. It is shown that AE can be used to monitor the process and to indicate the different process outcomes. PMID:15047268

  7. Polycyclic aromatic hydrocarbons' formation and occurrence in processed food.

    PubMed

    Singh, Lochan; Varshney, Jay G; Agarwal, Tripti

    2016-05-15

    Polycyclic aromatic hydrocarbons (PAHs) emerged as an important contaminant group in a gamut of processed food groups like dairy, nuts, herbs, beverages, meat products etc. Different cooking processes and processing techniques like roasting, barbecuing, grilling, smoking, heating, drying, baking, ohmic-infrared cooking etc. contribute towards its formation. The level of PAHs depends on factors like distance from heat source, fuel used, level of processing, cooking durations and methods, whereas processes like reuse, conching, concentration, crushing and storage enhance the amount of PAHs in some food items. This review paper provides insight into the impact of dietary intake of PAHs, its levels and formation mechanism in processed food items and possible interventions for prevention and reduction of the PAHs contamination. The gaps and future prospects have also been assessed. PMID:26776034

  8. Diffused Matrix Format: A New Storage and Processing Format for Airborne Hyperspectral Sensor Images

    PubMed Central

    Martínez, Pablo; Cristo, Alejandro; Koch, Magaly; Pérez, Rosa Mª.; Schmid, Thomas; Hernández, Luz M.

    2010-01-01

    At present, hyperspectral images are mainly obtained with airborne sensors that are subject to turbulences while the spectrometer is acquiring the data. Therefore, geometric corrections are required to produce spatially correct images for visual interpretation and change detection analysis. This paper analyzes the data acquisition process of airborne sensors. The main objective is to propose a new data format called Diffused Matrix Format (DMF) adapted to the sensor's characteristics including its spectral and spatial information. The second objective is to compare the accuracy of the quantitative maps derived by using the DMF data structure with those obtained from raster images based on traditional data structures. Results show that DMF processing is more accurate and straightforward than conventional image processing of remotely sensed data with the advantage that the DMF file structure requires less storage space than other data formats. In addition the data processing time does not increase when DMF is used. PMID:22399919

  9. On possibility of diamond formations in radiation process

    NASA Technical Reports Server (NTRS)

    Fisenko, A. V.; Semjonova, L. F.; Bolsheva, L. N.; Grachjova, T. V.; Verchovsky, A. B.; Shukolyukov, Yu. A.

    1993-01-01

    The possibility of diamond formation in radiation processes was checked by studying diamond contents in carburanium sample. The diamonds were not found and this result is discussed. At present one possible process of formation of nanometer-size diamond crystals in some meteorites and Earth's diamonds (carbonado), the radiation mechanism, is suggested: the formation of diamonds from carbonaceous matter in tracks of U fragment fissions and heavy fragmentation due to the action of energetic particles of cosmic rays. Bjakov et. al. have carried out the calculations and shown that the volume of formed diamonds in carbonaceous chondrites by radiation processes corresponds to discovery of diamond volume in chondrites. The discovery by Ozima et. al. of the unsupported fission of Xe and Kr in carbonado supports the supposition that carbonado could be formed by radiation processes. The possibility of diamond formation in radiation processes leads to the study of diamond contents in Earth's samples enriched by uranium and carbon. The attempt to release the diamonds from carburanium was undertaken.

  10. Gypsic pedofeatures and elementary pedogenetic processes of their formation

    NASA Astrophysics Data System (ADS)

    Yamnova, I. A.; Pankova, E. I.

    2013-12-01

    Elementary pedogenetic processes forming gypsic pedofeatures in gypsiferous soils are discussed. Several groups of such processes are distinguished: (1) weathering of gypsum-bearing rocks; (2) gypsum formation associated with weathering of sulfuric (pyritic) rocks; (3) precipitation of gypsum owing to the inflow of soil solutions saturated with Ca and SO4 and their evaporative concentration; (4) gypsum formation owing to exchange reactions in soils between calcium in the exchange complex and sodium sulfate solutions; (5) gypsum formation upon interaction of calcium carbonates with sodium sulfate water resulting in the loss of CaCO3 and gypsum accumulation (decalcification process); (6) colluvial and alluvial redeposition of gypsum in the landscape with its accumulation in the subordinate positions, where gypsiferous soils are formed; and (7) eolian deposition of gypsum on the soil surface with the formation of gypsum-bearing horizons. The micromorphological specificity of the gypsic pedofeatures reflects the processes of their destruction and/or accumulation in the soil profiles. It is shown that gypsum accumulation in soils is a pedogeochemical process that manifests itself in different natural zones upon the presence of gypsum sources.

  11. Studying the star formation process with adaptive optics

    NASA Astrophysics Data System (ADS)

    Menard, Francois; Dougados, Catherine; Duchene, Gaspard; Bouvier, Jerome; Duvert, Gilles; Lavalley, Claudia; Monin, Jean-Louis; Beuzit, Jean-Luc

    2000-07-01

    Young Stellar Objects (YSOs) are the builders of worlds. During its infancy, a star transforms ordinary interstellar dust particles into astronomical gold: planets to say the process is complex, and largely unknown to data. Yet, violent and spectacular events of mass ejection are witnessed, disks in keplerian rotation are detected, multiple stars dancing around each other are found. These are as many traces of the stellar and planet formation process. The high angular resolution provided by adaptive optics, and the related gain in sensitivity, have allowed major breakthrough discoveries to be made in each of these specific fields and our understanding of the various physical processes involved in the formation of a star has leaped forward tremendously over the last few years. In the following, meant as a report of the progress made recently in star formation due to adaptive optics, we will describe new results obtained at optical and near- infrared wavelengths, in imaging and spectroscopic modes. Our images of accretion disks and ionized stellar jets permit direct measurements of many physical parameters and shed light into the physics of the accretion and ejection processes. Although the accretion/ejection process so fundamental to star formation is usually studied around single objects, most of young stars form as part of multiple systems. We also present our findings on how the fraction of stars in binary systems evolves with age. The implications of these results on the conditions under which these stars must have formed are discussed.

  12. Investigation of formation mechanisms of chips in orthogonal cutting process

    NASA Astrophysics Data System (ADS)

    Ma, W.

    2012-08-01

    This work investigates the formation mechanisms of chips in orthogonal cutting of mild steel and the transformation conditions between various morphology chips. It is supposed that the modeling material follows the Johnson-Cook constitutive model. In orthogonal cutting process, both the plastic flow and the instability behaviors of chip materials are caused by the plane strain loadings. Therefore, the general instability behaviors of materials in plane strain state are first analyzed with linear perturbation method and a universal instability criterion is established. Based on the analytical results, the formation mechanisms of chips and the transformation conditions between continuous and serrated chips are further studied by instability phase diagram method. The results show that the chip formation strongly depends on the intensity ratios between shear and normal stresses. The ratios of dissipative rates of plastic work done by compression and shear stresses govern the transformation from continuous to serrated chips. These results are verified by the numerical simulations on the orthogonal cutting process.

  13. Deciphering records of geomagnetic reversals

    NASA Astrophysics Data System (ADS)

    Valet, Jean-Pierre; Fournier, Alexandre

    2016-06-01

    Polarity reversals of the geomagnetic field are a major feature of the Earth's dynamo. Questions remain regarding the dynamical processes that give rise to reversals and the properties of the geomagnetic field during a polarity transition. A large number of paleomagnetic reversal records have been acquired during the past 50 years in order to better constrain the structure and geometry of the transitional field. In addition, over the past two decades, numerical dynamo simulations have also provided insights into the reversal mechanism. Yet despite the large paleomagnetic database, controversial interpretations of records of the transitional field persist; they result from two characteristics inherent to all reversals, both of which are detrimental to an ambiguous analysis. On the one hand, the reversal process is rapid and requires adequate temporal resolution. On the other hand, weak field intensities during a reversal can affect the fidelity of magnetic recording in sedimentary records. This paper is aimed at reviewing critically the main reversal features derived from paleomagnetic records and at analyzing some of these features in light of numerical simulations. We discuss in detail the fidelity of the signal extracted from paleomagnetic records and pay special attention to their resolution with respect to the timing and mechanisms involved in the magnetization process. Records from marine sediments dominate the database. They give rise to transitional field models that often lead to overinterpret the data. Consequently, we attempt to separate robust results (and their subsequent interpretations) from those that do not stand on a strong observational footing. Finally, we discuss new avenues that should favor progress to better characterize and understand transitional field behavior.

  14. Reducing the potential for processing contaminant formation in cereal products

    PubMed Central

    Curtis, Tanya Y.; Postles, Jennifer; Halford, Nigel G.

    2014-01-01

    Processing contaminants may be defined as substances that are produced in a food when it is cooked or processed, are not present or are present at much lower concentrations in the raw, unprocessed food, and are undesirable either because they have an adverse effect on product quality or because they are potentially harmful. The presence of very low levels of processing contaminants in common foods is becoming an increasingly important issue for the food industry, as developments in analytical techniques and equipment bring foods under closer and closer scrutiny. This review considers the formation of lipid oxidation products, hydrogenation of polyunsaturated fatty acids to prevent lipid oxidation and the associated risk of trans fatty acid formation. The formation of acrylamide in the Maillard reaction is described, as well as the genetic and agronomic approaches being taken to reduce the acrylamide-forming potential of cereal grain. The multiple routes for the formation of furan and associated chemicals, including hydroxymethylfurfuryl, are also described. The evolving regulatory and public perception situations for these processing contaminants and their implications for the cereal supply chain are discussed, emphasising the need for cereal breeders to engage with the contaminants issue. PMID:24882936

  15. Processing biological literature with customizable Web services supporting interoperable formats

    PubMed Central

    Rak, Rafal; Batista-Navarro, Riza Theresa; Carter, Jacob; Rowley, Andrew; Ananiadou, Sophia

    2014-01-01

    Web services have become a popular means of interconnecting solutions for processing a body of scientific literature. This has fuelled research on high-level data exchange formats suitable for a given domain and ensuring the interoperability of Web services. In this article, we focus on the biological domain and consider four interoperability formats, BioC, BioNLP, XMI and RDF, that represent domain-specific and generic representations and include well-established as well as emerging specifications. We use the formats in the context of customizable Web services created in our Web-based, text-mining workbench Argo that features an ever-growing library of elementary analytics and capabilities to build and deploy Web services straight from a convenient graphical user interface. We demonstrate a 2-fold customization of Web services: by building task-specific processing pipelines from a repository of available analytics, and by configuring services to accept and produce a combination of input and output data interchange formats. We provide qualitative evaluation of the formats as well as quantitative evaluation of automatic analytics. The latter was carried out as part of our participation in the fourth edition of the BioCreative challenge. Our analytics built into Web services for recognizing biochemical concepts in BioC collections achieved the highest combined scores out of 10 participating teams. Database URL: http://argo.nactem.ac.uk. PMID:25006225

  16. Processing biological literature with customizable Web services supporting interoperable formats.

    PubMed

    Rak, Rafal; Batista-Navarro, Riza Theresa; Carter, Jacob; Rowley, Andrew; Ananiadou, Sophia

    2014-01-01

    Web services have become a popular means of interconnecting solutions for processing a body of scientific literature. This has fuelled research on high-level data exchange formats suitable for a given domain and ensuring the interoperability of Web services. In this article, we focus on the biological domain and consider four interoperability formats, BioC, BioNLP, XMI and RDF, that represent domain-specific and generic representations and include well-established as well as emerging specifications. We use the formats in the context of customizable Web services created in our Web-based, text-mining workbench Argo that features an ever-growing library of elementary analytics and capabilities to build and deploy Web services straight from a convenient graphical user interface. We demonstrate a 2-fold customization of Web services: by building task-specific processing pipelines from a repository of available analytics, and by configuring services to accept and produce a combination of input and output data interchange formats. We provide qualitative evaluation of the formats as well as quantitative evaluation of automatic analytics. The latter was carried out as part of our participation in the fourth edition of the BioCreative challenge. Our analytics built into Web services for recognizing biochemical concepts in BioC collections achieved the highest combined scores out of 10 participating teams. Database URL: http://argo.nactem.ac.uk. PMID:25006225

  17. Kinetics of Elementary Processes Relevant to Incipient Soot Formation

    SciTech Connect

    Lin, M C; Heaven, M C

    2008-04-30

    Soot formation and abatement processes are some of the most important and challenging problems in hydrocarbon combustion. The key reactions involved in the formation of polycyclic aromatic hydrocarbons (PAH's), the precursors to soot, remain elusive. Small aromatic species such as C5H5, C6H6 and their derivatives are believed to play a pivotal role in incipient soot formation. The goal of this project is to establish a kinetic database for elementary reactions relevant to soot formation in its incipient stages. In the past year, we have completed by CRDS the kinetics for the formation and decomposition of C6H5C2H2O2 in the C6H5C2H2 +O2 reaction and the formation of C10H7O2 in the C10H7 + O2 reaction by directly monitoring C6H5C2H2O2 and C10H7O2 radicals in the visible region; their mechanisms have been elucidated computationally by quantum-chemical calculations. The O + C2H5OH reaction has been studied experimentally and computationally and the OH + HNCN reaction has been investigated by ab initio molecular orbital calculation. In addition, a new pulsed slit molecular beam system has been constructed and tested for spectroscopic studies of aromatic radicals and their derivatives by the cavity ringdown technique (CRDS).

  18. Modified Polar-Format Software for Processing SAR Data

    NASA Technical Reports Server (NTRS)

    Chen, Curtis

    2003-01-01

    HMPF is a computer program that implements a modified polar-format algorithm for processing data from spaceborne synthetic-aperture radar (SAR) systems. Unlike prior polar-format processing algorithms, this algorithm is based on the assumption that the radar signal wavefronts are spherical rather than planar. The algorithm provides for resampling of SAR pulse data from slant range to radial distance from the center of a reference sphere that is nominally the local Earth surface. Then, invoking the projection-slice theorem, the resampled pulse data are Fourier-transformed over radial distance, arranged in the wavenumber domain according to the acquisition geometry, resampled to a Cartesian grid, and inverse-Fourier-transformed. The result of this process is the focused SAR image. HMPF, and perhaps other programs that implement variants of the algorithm, may give better accuracy than do prior algorithms for processing strip-map SAR data from high altitudes and may give better phase preservation relative to prior polar-format algorithms for processing spotlight-mode SAR data.

  19. Controlled formation of multiple Taylor cones in electrospinning process

    NASA Astrophysics Data System (ADS)

    Vaseashta, A.

    2007-02-01

    Electrospinning is a versatile technique for preparation of micro- and nanoscale fibers using polymer solutions. The study presented here describes an observation of multiple Taylor cones in electrospinning processes. Plausible physical models explaining the formation and modeling of multiple Taylor cones in terms of the process and polymer solution parameters are presented. A thorough understanding of the process will lead to the preparation of fibers by design, system on fibers, and e-textiles having applications ranging from biomedical devices, environmental pollution and prevention, to global security and defense.

  20. What triggered the early planet formation processes in HL Tau?

    NASA Astrophysics Data System (ADS)

    Plevne, O.

    2016-06-01

    T Tauri stars are in the pre-main sequence phase of stellar evolution. These stars convert their own gravitational potential energy to light, but their cores do not have enough temperature for nuclear reactions like a main sequence star. T Tauri stars are surrounded by a circumstellar disk, hot plasma and dust. Some T Tauri stars host protoplanetary objects in their circumstellar disk such as HL Tau. In this case HL Tau system is a good example for stellar evolution and planet formation. But HL Tau's protoplanetary objects were formed earlier than planet formation theories' expectations. With this purpose, this study will discuss "What triggered the early planet formation processes in HL Tau system?" with XMM-Newton and Chandra observations of HL Tau system.

  1. The formation of blobs from a pure interchange process

    SciTech Connect

    Zhu, P.; Sovinec, C. R.; Hegna, C. C.

    2015-02-15

    In this work, we focus on examining a pure interchange process in a shear-less slab configuration as a prototype mechanism for blob formation. We employ full magnetohydrodynamic simulations to demonstrate that the blob-like structures can emerge through the nonlinear development of a pure interchange instability originating from a pedestal-like transition region. In the early nonlinear stage, filamentary structures develop and extend in the direction of the effective gravity. The blob-like structures appear when the radially extending filaments break off and disconnect from the core plasma. The morphology and the dynamics of these filaments and blobs vary dramatically with a sensitive dependence on the dissipation mechanisms in the system and the initial perturbation. Despite the complexity in morphology and dynamics, the nature of the entire blob formation process in the shear-less slab configuration remains strictly interchange without involving any change in magnetic topology.

  2. Collisional and dynamical processes in moon and planet formation

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The collisional and dynamical processes in moon and planet formation are discussed. A hydrodynamic code of collision calculations, the orbital element changes due to gravitational scattering, a validation of the mass shifting algorithm, a theory of rotations, and the origin of asteroids are studied. A numerical model of planet growth is discussed and a methodology to evaluate the rate at which megaregolith increases its depth as a function of total accumulate number of impacts on an initially smooth, coherent surface is described.

  3. Segment formation in Annelids: patterns, processes and evolution.

    PubMed

    Balavoine, Guillaume

    2014-01-01

    The debate on the origin of segmentation is a central question in the study of body plan evolution in metazoans. Annelids are the most conspicuously metameric animals as most of the trunk is formed of identical anatomical units. In this paper, I summarize the various patterns of evolution of the metameric body plan in annelids, showing the remarkable evolvability of this trait, similar to what is also found in arthropods. I then review the different modes of segment formation in the annelid tree, taking into account the various processes taking place in the life histories of these animals, including embryogenesis, post-embryonic development, regeneration and asexual reproduction. As an example of the variations that occur at the cellular and genetic level in annelid segment formation, I discuss the processes of teloblastic growth or posterior addition in key groups in the annelid tree. I propose a comprehensive definition for the teloblasts, stem cells that are responsible for sequential segment addition. There are a diversity of different mechanisms used in annelids to produce segments depending on the species, the developmental time and also the life history processes of the worm. A major goal for the future will be to reconstitute an ancestral process (or several ancestral processes) in the ancestor of the whole clade. This in turn will provide key insights in the current debate on ancestral bilaterian segmentation. PMID:25690963

  4. Diagnostics of Nano-Particle Formation in Process Plasmas

    NASA Astrophysics Data System (ADS)

    Kersten, Holger

    2015-09-01

    The main sources of particle generation during plasma surface processing and the formation of nano-composite materials are (i) the formation of large molecules, mesoscopic clusters and particles in the plasma bulk by chemically reactive gases, and (ii) the formation and incorporation of particles at surfaces (target, substrate) by means of plasma-wall interaction. The plasma process promotes the particle formation by excitation, dissociation and reaction of the involved species in the gas phase. The different stages of the particle growth in the gas phase can be observed by various plasma diagnostics as mass spectrometry, laser induced evaporation, photo-detachment, IR absorption, microwave cavity measurements, Mie scattering and self-excited electron resonance spectroscopy (SEERS). Common diagnostics of particle formation also use the observation and analysis of harmonics and other discharge characteristics. Especially the early stages of the particle growth are not well investigated since they are experimentally inaccessible by standard methods as mentioned above. A novel collection method based on neutral drag was tested in order to get a better insight into the early stages of particle growth. The experiments were performed in an asymmetric, capacitively coupled rf-discharge, where multiple growth cycles can be obtained. Making use of the correlation between the particle growth cycles and the bias voltage as well as the phase angle between discharge current and voltage it was possible to monitor each growth process in-situ. This allowed to collect particles at any desired stage of the growth cycle via the neutral drag method. Size distributions of the nanoparticles at the different stages of the growth cycle were determined ex-situ by transmission electron microscopy. The observed correlations of particle size and bias voltage, which can be used for prediction of the particle growth, are qualitatively explained. Furthermore, the change of the electron density

  5. Chemical and Chemoenzymatic Synthesis of Glycoproteins for Deciphering Functions

    PubMed Central

    Wang, Lai-Xi; Amin, Mohammed N.

    2014-01-01

    Summary Glycoproteins are an important class of biomolecules involved in a number of biological recognition processes. However, natural and recombinant glycoproteins are usually produced as mixtures of glycoforms that differ in the structures of the pendent glycans, which are difficult to separate in pure glycoforms. As a result, synthetic homogeneous glycopeptides and glycoproteins have become indispensable probes for detailed structural and functional studies. A number of elegant chemical and biological strategies have been developed for synthetic construction of tailor-made, full-size glycoproteins to address specific biological problems. In this review, we highlight recent advances in chemical and chemoenzymatic synthesis of homogeneous glycoproteins. Selected examples are given to demonstrate the applications of tailor-made, glycan-defined glycoproteins for deciphering glycosylation functions. PMID:24439206

  6. Formation characteristics of PCDD and PCDF during pyrolysis processes.

    PubMed

    Weber, R; Sakurai, T

    2001-12-01

    In recent years, pyrolysis processes have become technologies developed to industrial scale and discussed as alternatives to the existing waste combustion technology. However, little information is published regarding PCDD/F formation characteristics during pyrolysis processes. Two common shredder fractions--industrial light shredder (ILS) and refrigerators (REF)--both with high chlorine and copper content were pyrolysed for this pyrolysis study using a pilot plant with a capacity of 100 kg/h. At oxygen concentrations below 2% and temperatures between 430 degrees C and 470 degrees C, considerable amounts of PCDD/F were formed during the pyrolysis. More than 90% of total TEQ was found in the oil fraction (gas phase). The PCDD/PCDF ratio and the homologue pattern differed significantly from those formed during waste incineration. Considering mono- to octachlorinated congeners, up to 400 times more PCDF were formed compared to PCDD. For the investigated pyrolysis conditions, the formation of low chlorinated congeners was highly favoured. The distribution of TEQ within the individual congeners were very similar in all investigated runs. More than 80% of total TEQ stem from 2,3,7,8-substituted T4CDF and P5CDF. The isomer pattern, however, did not show significant differences compared to the common waste incineration pattern suggesting that the basic formation routes are similar. PMID:11695624

  7. [Study on bromate formation of catalytic ozonation process].

    PubMed

    Wu, Lin; Yang, Hong-Wei; Yang, Shao-Xia; Lü, Miao; Cheng, Wen

    2011-08-01

    In a batch reactor, the BrO3(-) formation was investigated in the ozonation and catalytic ozonation of Br(-)-containing Yellow river water, using the different heterogeneous catalysts. The results showed that BrO3(-) minimization was achieved in the catalytic ozonation with NiO, CuO, Fe3O4 and Al2O3 as catalysts and the percent reductions of BrO3(-) were 34.0%, 32.8%, 29.2% and 20.8% respectively. In the reaction R(ct), the ratio of concentration of *OH to O3, decreased with the reaction time, and the range of R(ct) was from 10(-8) to 10(-6). In the ozonation process, one of the main reaction pathways of BrO3(-) formation was the combination oxidation of Br(-) by *OH and then O3, another was the combination oxidation of Br(-) by O3 and then *OH. In the catalytic ozonation with Fe3O4 catalyst, the main pathway was the combination oxidation by *OH and then O3. Moreover, about 60.7% removal for UV254 was obtained after 20 min in the catalytic ozonation reaction. In our study, it was found that the catalytic ozonation process can effectively minimize the formation of BrO3(-) and also oxidize organic compounds. PMID:22619950

  8. Phase formation and melt processing of Yb- 123.

    SciTech Connect

    Athur, S. P.; Putman, P.; Balachandran, U.; Salama, K.; Energy Technology; Univ. of Houston

    1998-01-01

    The formation of Yb-123 has been studied at different temperatures in air and in reduced oxygen partial pressure. It is found that the stability and/or the formation kinetics of Yb-123 phase is a major hurdle in manufacturing phase-pure Yb-123 in air. However, under reduced oxygen partial pressure, Yb-123 forms rapidly and more than 90% phase-pure Yb-123 is achieved within three sintering steps. Rods made from this powder were melt-processed in air and showed a T{sub c} of 90 K. Kinetic studies performed by interrupting the growth during the directional solidification of these rods revealed a growth mechanism similar to that of Y-123 and a maximum growth rate of 7.2 mm/h for a stable planar interface. EPMA of the interface showed the liquid to be rich in barium cuprates with a Ba:Cu ratio of 1:3.

  9. Processing treatments for mitigating acrylamide formation in sweetpotato French fries.

    PubMed

    Truong, Van-Den; Pascua, Yvette T; Reynolds, Rong; Thompson, Roger L; Palazoğlu, T Koray; Mogol, Burce Atac; Gökmen, Vural

    2014-01-01

    Acrylamide formation in sweetpotato French fries (SPFF) is likely a potential health concern as there is an increasing demand for good-quality fries from carotene-rich sweetpotatoes (SP). This is the first report on acrylamide formation in SPFF as affected by processing methods. Acrylamide levels in SPFF from untreated SP strips fried at 165 °C for 2, 3, and 5 min were 124.9, 255.5, and 452.0 ng/g fresh weight, which were reduced by about 7 times to 16.3, 36.9, and 58.3 ng/g, respectively, when the strips were subjected to processing that included water blanching and soaking in 0.5% sodium acid pyrophosphate before frying. An additional step of strip soaking in 0.4% calcium chloride solution before par-frying increased the calcium content from 0.2 to 0.8 mg/g and decreased the acrylamide levels to 6.3, 17.6, and 35.4 ng/g, respectively. SPFF with acrylamide level of <100 ng/g or several times lower than that of white potato French fries can be obtained by integrating processing treatments commonly used in the food industry. PMID:24328312

  10. Carbon formation and metal dusting in advanced coal gasification processes

    SciTech Connect

    DeVan, J.H.; Tortorelli, P.F.; Judkins, R.R.; Wright, I.G.

    1997-02-01

    The product gases generated by coal gasification systems contain high concentrations of CO and, characteristically, have relatively high carbon activities. Accordingly, carbon deposition and metal dusting can potentially degrade the operation of such gasifier systems. Therefore, the product gas compositions of eight representative gasifier systems were examined with respect to the carbon activity of the gases at temperatures ranging from 480 to 1,090 C. Phase stability calculations indicated that Fe{sub 3}C is stable only under very limited thermodynamic conditions and with certain kinetic assumptions and that FeO and Fe{sub 0.877}S tend to form instead of the carbide. As formation of Fe{sub 3}C is a necessary step in the metal dusting of steels, there are numerous gasifier environments where this type of carbon-related degradation will not occur, particularly under conditions associated with higher oxygen and sulfur activities. These calculations also indicated that the removal of H{sub 2}S by a hot-gas cleanup system may have less effect on the formation of Fe{sub 3}C in air-blown gasifier environments, where the iron oxide phase can exist and is unaffected by the removal of sulfur, than in oxygen-blown systems, where iron sulfide provides the only potential barrier to Fe{sub 3}C formation. Use of carbon- and/or low-alloy steels dictates that the process gas composition be such that Fe{sub 3}C cannot form if the potential for metal dusting is to be eliminated. Alternatively, process modifications could include the reintroduction of hydrogen sulfide, cooling the gas to perhaps as low as 400 C and/or steam injection. If higher-alloy steels are used, a hydrogen sulfide-free gas may be processed without concern about carbon deposition and metal dusting.

  11. Process and apparatus for formation of photovoltaic compounds

    DOEpatents

    Hall, Robert B.; Rocheleau, Richard E.

    1985-01-01

    The invention relates to a process and apparatus for formation and deposition of thin films on a substrate, in a vacuum, by evaporation of the elements to form a Zn.sub.x Cd.sub.1-x S compound having a preselected fixed ratio of cadmium to zinc, characterized by the evaporation of cadmium and zinc at a rate the ratio of which is proportional to the stoichiometric ratio of those elements in the intended compound and evaporation of sulfur at a rate at least twice the combined rates of cadmium and zinc, and at least twice that required by the stoichiometry of the intended compound.

  12. Deciphering Transcriptional Dynamics In Vivo by Counting Nascent RNA Molecules

    PubMed Central

    Choubey, Sandeep; Kondev, Jane; Sanchez, Alvaro

    2015-01-01

    Abstract Deciphering how the regulatory DNA sequence of a gene dictates its expression in response to intra and extracellular cues is one of the leading challenges in modern genomics. The development of novel single-cell sequencing and imaging techniques, as well as a better exploitation of currently available single-molecule imaging techniques, provides an avenue to interrogate the process of transcription and its dynamics in cells by quantifying the number of RNA polymerases engaged in the transcription of a gene (or equivalently the number of nascent RNAs) at a given moment in time. In this paper, we propose that measurements of the cell-to-cell variability in the number of nascent RNAs provide a mostly unexplored method for deciphering mechanisms of transcription initiation in cells. We propose a simple kinetic model of transcription initiation and elongation from which we calculate nascent RNA copy-number fluctuations. To demonstrate the usefulness of this approach, we test our theory against published nascent RNA data for twelve constitutively expressed yeast genes. Rather than transcription being initiated through a single rate limiting step, as it had been previously proposed, our single-cell analysis reveals the presence of at least two rate limiting steps. Surprisingly, half of the genes analyzed have nearly identical rates of transcription initiation, suggesting a common mechanism. Our analytical framework can be used to extract quantitative information about dynamics of transcription from single-cell sequencing data, as well as from single-molecule imaging and electron micrographs of fixed cells, and provides the mathematical means to exploit the quantitative power of these technologies. PMID:26544860

  13. Formation of niobium nitride by rapid thermal processing.

    PubMed

    Angelkort, C; Lewalter, H; Warbichler, P; Hofer, F; Bock, W; Kolbesen, B O

    2001-09-01

    The formation of group V transition metal nitride films by means of rapid thermal processing (RTP) has been investigated. Here we focus on the nitridation of niobium films of 200-500 nm thickness in the temperature range from 500 to 1,100 degrees C under laminar flow of molecular nitrogen or ammonia. The nitride phases formed were characterized by X-ray diffraction (XRD). Secondary neutral mass spectrometry (SNMS) and transmission electron microscopy (TEM) in combination with electron energy loss spectroscopy (EELS) were carried out on samples of selected experiments to provide more detailed information about the initial stages of nitride formation and the microstructure of the films. A classical formation sequence of nitride phases was observed with increasing nitrogen content in the order: alpha-Nb(N) --> beta-Nb2N --> gamma-Nb4N3 --> delta'-NbN --> Nb5N6. Furthermore, oxide enriched regions were discovered inside the metal films. These turned out to be formed mainly in the nitride sequence between the a-alphaNb(N) and beta-Nb2N-phases at the Nb/SiO2 interface due to a reaction of the Nb with the SiO2 layer of the silicon substrates on which the films had been deposited. The SiO2 layer acts as diffusion barrier for nitrogen but also as source for oxygen, according to SNMS and TEM/EELS studies, resulting in the formation of Nb-oxides and/or oxynitrides at the Nb/SiO2 interface. PMID:11666087

  14. Formation of niobium nitride by rapid thermal processing

    NASA Astrophysics Data System (ADS)

    Angelkort, C.; Lewalter, H.; Warbichler, P.; Hofer, F.; Bock, W.; Kolbesen, B. O.

    2001-09-01

    The formation of group V transition metal nitride films by means of rapid thermal processing (RTP) has been investigated. Here we focus on the nitridation of niobium films of 200-500 nm thickness in the temperature range from 500 to 1100°C under laminar flow of molecular nitrogen or ammonia. The nitride phases formed were characterized by X-ray diffraction (XRD). Secondary neutral mass spectrometry (SNMS) and transmission electron microscopy (TEM) in combination with electron energy loss spectroscopy (EELS) were carried out on samples of selected experiments to provide more detailed information about the initial stages of nitride formation and the microstructure of the films. A classical formation sequence of nitride phases was observed with increasing nitrogen content in the order: α-Nb(N)→β-Nb 2N→γ-Nb 4N 3→δ'-NbN→Nb 5N 6. Furthermore, oxide enriched regions were discovered inside the metal films. These turned out to be formed mainly in the nitride sequence between the a-αNb(N) and β-Nb 2N-phases at the Nb/SiO 2 interface due to a reaction of the Nb with the SiO 2 layer of the silicon substrates on which the films had been deposited. The SiO 2 layer acts as diffusion barrier for nitrogen but also as source for oxygen, according to SNMS and TEM/EELS studies, resulting in the formation of Nb-oxides and/or oxynitrides at the Nb/SiO 2 interface.

  15. PSEUDOBULGE FORMATION AS A DYNAMICAL RATHER THAN A SECULAR PROCESS

    SciTech Connect

    Guedes, Javiera; Mayer, Lucio; Carollo, Marcella; Madau, Piero

    2013-07-20

    We investigate the formation and evolution of the pseudobulge in 'Eris', a high-resolution N-body + smoothed particle hydrodynamic cosmological simulation that successfully reproduces a Milky-Way-like massive late-type spiral in an cold dark matter universe. At the present epoch, Eris has a virial mass M{sub vir} {approx_equal} 8 Multiplication-Sign 10{sup 11} M{sub Sun }, a photometric stellar mass M{sub *} = 3.2 Multiplication-Sign 10{sup 10} M{sub Sun }, a bulge-to-total ratio B/T = 0.26, and a weak nuclear bar. We find that the bulk of the pseudobulge forms quickly at high redshift via a combination of non-axisymmetric disk instabilities and tidal interactions or mergers, both occurring on dynamical timescales, not through slow secular processes at lower redshift. Its subsequent evolution is not strictly secular either, and is closely intertwined with the evolution of the stellar bar. In fact, the structure that we recognize as a pseudobulge today evolved from a stellar bar that formed at high redshift due to tidal interactions with satellites, was destroyed by minor mergers at z {approx} 3, re-formed shortly after, and weakened again following a steady gas inflow at z {approx}< 1. The gradual dissolution of the bar ensued at z {approx} 1 and continues until the present without increasing the stellar velocity dispersion in the inner regions. In this scenario, the pseudobulge is not a separate component from the inner disk in terms of formation path; rather, it is the first step in the inside-out formation of the baryonic disk, in agreement with the fact that pseudobulges of massive spiral galaxies typically have a dominant old stellar population. If our simulations do indeed reproduce the formation mechanisms of massive spirals, then the progenitors of late-type galaxies should have strong bars and small photometric pseudobulges at high redshift.

  16. Aroma formation by immobilized yeast cells in fermentation processes.

    PubMed

    Nedović, V; Gibson, B; Mantzouridou, T F; Bugarski, B; Djordjević, V; Kalušević, A; Paraskevopoulou, A; Sandell, M; Šmogrovičová, D; Yilmaztekin, M

    2015-01-01

    Immobilized cell technology has shown a significant promotional effect on the fermentation of alcoholic beverages such as beer, wine and cider. However, genetic, morphological and physiological alterations occurring in immobilized yeast cells impact on aroma formation during fermentation processes. The focus of this review is exploitation of existing knowledge on the biochemistry and the biological role of flavour production in yeast for the biotechnological production of aroma compounds of industrial importance, by means of immobilized yeast. Various types of carrier materials and immobilization methods proposed for application in beer, wine, fruit wine, cider and mead production are presented. Engineering aspects with special emphasis on immobilized cell bioreactor design, operation and scale-up potential are also discussed. Ultimately, examples of products with improved quality properties within the alcoholic beverages are addressed, together with identification and description of the future perspectives and scope for cell immobilization in fermentation processes. PMID:25267117

  17. Particle Formation by Supercritical Fluid Extraction and Expansion Process

    PubMed Central

    Zhou, Junbo; Li, Haiting; Quan, Can

    2013-01-01

    Supercritical fluid extraction and expansion (SFEE) patented technology combines the advantages of both supercritical fluid extraction (SFE) and rapid expansion of supercritical solution (RESS) with on-line coupling, which makes the nanoparticle formation feasible directly from matrix such as Chinese herbal medicine. Supercritical fluid extraction is a green separation technology, which has been developed for decades and widely applied in traditional Chinese medicines or natural active components. In this paper, a SFEE patented instrument was firstly built up and controlled by LABVIEW work stations. Stearic acid was used to verify the SFEE process at optimized condition; via adjusting the preexpansion pressure and temperature one can get different sizes of particles. Furthermore, stearic acid was purified during the SFEE process with HPLC-ELSD detecting device; purity of stearic acid increased by 19%, and the device can purify stearic acid. PMID:24223031

  18. The Stratigraphic Expression of Formative Processes in Channels

    NASA Astrophysics Data System (ADS)

    Hubbard, S. M.; Covault, J. A.; Fildani, A.; Romans, B.

    2014-12-01

    The stratigraphic record of sinuous fluvial and deep sea channel deposits contains a wealth of information about formative sedimentary processes. For fluvial systems, deposits are considered in the context of processes observed in rivers, with the point bar facies model, as an example, representing a well-established linkage between process and product. A direct link has not been achieved in the deep sea as direct monitoring of coarse-grained sediment transport is challenging, exacerbated by the sporadic and infrequent nature of flows. Until a method for direct observation is developed and widely applied, the stratigraphic record of sediment transfer in the deep sea provides a critical perspective and unique insight into processes that shape not only ancient basin margin slopes, but also the present day seascape. Despite the obvious similarity in sinuous planforms of open, single thread fluvial and deep sea channels, outcrop characteristics, validated in many instances by experimental and theoretical work, indicate different processes. Meandering fluvial systems are most commonly represented by deposits that reflect point bar migration, a process whereby bank erosion and bar growth are genetically linked. At the bed scale, cross-stratification reflects bedload sediment transport and deposition by traction sedimentation. Single thread deep sea channel-fill strata are commonly characterized by sandstone-filled channelform bodies, which reflect both traction and suspension sedimentation. Heterolithic thin beds and cross-stratification can be locally preserved above channel bases and against channel margins, but the majority of depositional thickness comprises tabular sandstone turbidites that bi-directionally lap onto channel edges. The stratal record indicates a distinction between phases of channel maintenance (e.g., erosion, sediment bypass) and phases of substantial infilling with coarse-grained sediment - they are not contemporaneous. This is a key departure from

  19. Are amphitheater headed canyons indicative of a particular formative process?

    NASA Astrophysics Data System (ADS)

    Ryan, A. J.; Whipple, K. X.; Johnson, J. P.

    2012-12-01

    Tributary canyons with amphitheater-shaped heads have previously been interpreted as evidence for groundwater seepage erosion, particularly in environments where fluvial processes are assumed to be negligible. However, some have questioned whether this canyon morphology is truly diagnostic of a particular formative process. We seek to determine the relative roles of fluvial and groundwater-related processes and the strength of stratigraphic control on the Colorado Plateau through a combination of fieldwork and GIS analysis. Amphitheater valleys may have overhanging or steep-sided headwalls with a semicircular plan-view pattern. It is reasonable to assume that this form is a result of focused erosion at the base of the headwall (i.e. sapping). Two frequently cited agents may lead to undermining: plunge-pool scour at the base of waterfalls and seepage induced weathering and erosion where the groundwater table intersects the land surface. Both processes are enhanced where weaker, less permeable layers underlie stronger cap rock. We conducted preliminary fieldwork in two locations on the Colorado Plateau, where there are many classic examples of amphitheater headed canyons. The Escalante River landscape is highly variable with a range of canyon and valley-head forms, many of which cut through the thick Navajo Sandstone into the underlying shale and sand of the Kayenta Formation. Northeast of Escalante National Monument, at the base of the Henry Mountains, is Tarantula Mesa. The canyons there are also considerably variable, with nearly all containing at least one abrupt amphitheater knickpoint at the valley head or farther downstream. Our observations are presented here with an analysis of the canyon profiles, surrounding topography, and potential structural controls. We have found that nearly all amphitheaters in both locales show signs of groundwater seepage weathering and plausibly seepage erosion. However, many also contain plunge pools and evidence of substantial

  20. POX 186: A Dwarf Galaxy in the Process of Formation?

    NASA Astrophysics Data System (ADS)

    Corbin, Michael R.; Vacca, William D.

    2002-12-01

    We present deep U-, V-, and I-band images of the ``ultracompact'' blue dwarf galaxy POX 186 obtained with the Planetary Camera 2 of the Hubble Space Telescope. We have also obtained a near-ultraviolet spectrum of the object with the Space Telescope Imaging Spectrograph and combine this with a new ground-based optical spectrum. The images confirm the galaxy to be extremely small, with a maximum extent of only 300 pc, a luminosity of ~10-4L*, and an estimated mass of ~107 Msolar. Its morphology is highly asymmetric, with a tail of material on its western side that may be tidal in origin. The U-band image shows this tail to be part of a stream of material in which stars have recently formed. Most of the star formation in the galaxy is, however, concentrated in a central, compact (d~10-15 pc) star cluster. We estimate this cluster to have a total mass of ~105 Msolar, to be forming stars at a rate of less than 0.05 yr-1, and to have a maximum age of a few million years. The outer regions of the galaxy are significantly redder than the cluster, with V-I colors consistent with a population dominated by K and M stars. From our analysis of the optical spectrum we find the galaxy to have a metallicity Z~=0.06 Zsolar and to contain a significant amount of internal dust [E(B-V)~=0.28] both values agree with previous estimates. While these results rule out earlier speculation that POX 186 is a protogalaxy, its morphology, mass, and active star formation suggest that it represents a recent (within ~108 yr) collision between two clumps of stars of subgalactic size (~100 pc). POX 186 may thus be a very small dwarf galaxy that, dynamically speaking, is still in the process of formation. This interpretation is supported by the fact that it resides in a void, so its morphology cannot be explained as the result of an encounter with a more massive galaxy. Clumps of stars this small may represent the building blocks required by hierarchical models of galaxy formation, and these results

  1. Chemical inhibition of PCDD/F formation in incineration processes.

    PubMed

    Ruokojärvi, Päivi H; Asikainen, Arja H; Tuppurainen, Kari A; Ruuskanen, Juhani

    2004-06-01

    This review summarises results of our pilot-scale experiments to find suitable inhibitors for preventing the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) during waste incineration and to specify the role of the main factors affecting the inhibition process, and is based on doctoral dissertation of Ruokojaärvi (2002). Results of previous experiments reported by other researchers are also presented and compared with ours. The detailed aims of our experiments were (1) to compare the effects of different inhibitors on PCDD/F formation during incineration in a pilot plant, (2) to investigate the role of the particle size distribution of the flue gas on the inhibition of PCDD/Fs, and (3) to find the main parameters affecting PCDD/F inhibition in waste incineration. Prevention of the formation of PCDD/Fs with chemical inhibitors and the effects of different supply points, feed temperatures and process parameters were studied in a pilot scale incinerator (50 kW) using light heating oil and refuse-derived fuel as test fuels. Various concentrations of the gaseous inhibitors (sulfur dioxide, ammonia, dimethylamine and methyl mercaptan) were sprayed into the flue gases after the furnace, in addition to which urea was dissolved in water and injected in at different concentrations. The residence time of the flue gas between the furnace and the PCDD/F sampling point was varied in the tests. In another set of urea tests, urea-water solutions at three concentrations were mixed with the RDF prior to incineration. PCDD/F and chlorophenol concentrations, together with other flue gas parameters (e.g. temperature, O2, CO, CO2 and NO), were analysed in the cooling flue gases. The gaseous and liquid inhibitors both notably reduced PCDD/F concentrations in the flue gas, the reductions achieved with the gaseous inhibitors varying from 50 to 78%, with dimethyl amine the most effective, while that produced with urea was up to 90%. The PCDD/F reductions were

  2. Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal

    SciTech Connect

    Liu, Hui-Hai; Rutqvist, Jonny; Zheng, Liange; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens

    2010-08-31

    As a result of the termination of the Yucca Mountain Project, the United States Department of Energy (DOE) has started to explore various alternative avenues for the disposition of used nuclear fuel and nuclear waste. The overall scope of the investigation includes temporary storage, transportation issues, permanent disposal, various nuclear fuel types, processing alternatives, and resulting waste streams. Although geologic disposal is not the only alternative, it is still the leading candidate for permanent disposal. The realm of geologic disposal also offers a range of geologic environments that may be considered, among those clay shale formations. Figure 1-1 presents the distribution of clay/shale formations within the USA. Clay rock/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at Mol site, Belgium (Barnichon et al., 2005) have all been under intensive scientific investigations (at both field and laboratory scales) for understanding a variety of rock properties and their relations with flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated and plastic clays (Tsang et al., 2005). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. For both clay rocks, coupled thermal, hydrological, mechanical and chemical (THMC) processes are expected to have a significant impact on the long-term safety of a clay repository. For

  3. Deciphering DOC export dynamics in a small catchment using high frequency monitoring and numerical modeling

    NASA Astrophysics Data System (ADS)

    Fleckenstein, Jan H.; Frei, Sven; Knorr, Klaus-Holger; Peiffer, Stefan; Matzner, Egbert; Strohmeier, Stefan; Partington, Daniel

    2014-05-01

    Concentrations of dissolved organic carbon (DOC) in stream water have been increasing across Northern Europe and in other parts of the world posing problems for the ecological health of aquatic systems and drinking water production from surface water. Elevated loads of DOC in reservoirs increase the costs for drinking water production and may result in the formation of toxic by-products during chlorination of the raw water. Understanding the dynamics and mechanisms of DOC export from catchments is an important prerequisite for a mitigation of these problems. Developing robust quantitative models that can replicate observed current dynamics or even predict future trends is challenging as catchments are complex systems that integrate a large number of hydrologic and biogeochemical processes to generate an integral solute flux signal at the catchment outlet. Physically based numerical process models that try to represent all possible processes and simulate the system bottom-up are often unwieldy and difficult to parameterize (e.g. equifinality). Simpler conceptual models are typically based on a set of assumptions about the functioning of the system that are often not grounded in the "reality" or complexity of a specific site and which can constrain our ability to understand the system. New sensing technologies that provide highly resolved data sets (in time and space) can open a complimentary window to look at the system in a data-driven top-down approach. Export of DOC from a small forested catchment in southern Germany is used as an example to illustrate how highly resolved concentration and discharge time series can help to decipher complex DOC export dynamics and challenge and/or support process representations and assumptions in a conceptual and a process-based numerical model for the catchment.

  4. The mineralogy and formation processes of Mars soil

    NASA Technical Reports Server (NTRS)

    Banin, Amos

    1992-01-01

    The mineralogical nature of Mars soil is far from being understood, nor are the formation time and weathering processes known. Quantitatively, the two major mineral-forming elements in Mars soil are silicon and iron, constituting 44 and 19 percent of the soils as SiO4 and Fe2O3, respectively. The silicate phases have been studied only briefly, mostly because of their limited spectral fingerprinting in the VIS and NIR. Much attention was given to the iron minerals in the soil, due to their pronounced absorption in the VIS and NIR, making them easily detectable by telescopic observations. The available information on Mars soil mineralogy, mostly obtained by remote sensing, is reviewed, and it is hypothesized that it leads to the suggestion that nanophase short-range-order (amorphous) phases of the silicates and iron oxides abound in the soil.

  5. mRNA retroposition in human cells: processed pseudogene formation.

    PubMed Central

    Maestre, J; Tchénio, T; Dhellin, O; Heidmann, T

    1995-01-01

    Using a sensitive assay for detection of reverse transcription events, we demonstrate that human HeLa cells can 'retropose', i.e. reverse transcribe and integrate, the mRNA of a naive reporter gene, at a low but detectable frequency. Furthermore, we show that the retroposed copies have all the hallmarks of the processed pseudogenes naturally found in the mammalian genome: they lack intron and 5' promoter sequence, they have acquired a 3' poly(A) tail, and they are flanked by short repeats (< 15 bp) of target DNA sequence. These results demonstrate that human cells possess an endogenous reverse transcription activity, which is not restricted to transcripts of transposable elements, and which is likely to be involved in the formation, still ongoing, of a large fraction of the eukaryotic genome. Images PMID:8557053

  6. Evaluating Key Processes the Formation of Giant Planet Cores

    NASA Astrophysics Data System (ADS)

    Levison, Harold F.; Thommes, E.; Duncan, M. J.

    2009-09-01

    One of the most challenging problems we face in our understanding of planet formation is how Jupiter and Saturn could have formed before the the solar nebula dispersed. The most popular model of giant planet formation is the so-called 'core accretion' model. In this model a large planetary embryo formed first, mainly by two-body accretion. This is then followed by a period of inflow of nebular gas directly onto the growing planet. The core accretion model has an Achilles heel, namely the very first step. We have undertaken the most comprehensive study of this process to date. In this study we numerically integrate the orbits of a number of planetary embryos embedded in a swarm of planetesimals. In these experiments we have included a large number of physical processes that might enhance accretion. In particular, we have included: 1) aerodynamic gas drag, 2) collisional damping between planetesimals, 3) enhanced embryo cross-sections due to their atmospheres, 4) planetesimal fragmentation, and 5) planetesimal driven migration. We find that the gravitational interaction between the embryos and the planetesimals lead to the wholesale redistribution of material - regions are cleared of material and gaps open near the embryos. Indeed, in 90% of our simulations without fragmentation, the region near that embryos is cleared of planetesimals before much growth can occur. The remaining 10%, however, the embryos undergo a burst of outward migration that significantly increases growth. On timescales of 100,000 years, the outer embryo can migrate 6 AU and grow to roughly 30 Earth-masses. We also find that the inclusion of planetesimal fragmentation tends to inhibit growth. This work as been directly supported by a grant from the National Science Foundation (Award ID 0708775). HFL is also grateful for funding from NASA's Origins and OPR programs.

  7. Basics of Polar-Format algorithm for processing Synthetic Aperture Radar images.

    SciTech Connect

    Doerry, Armin Walter

    2012-05-01

    The purpose of this report is to provide a background to Synthetic Aperture Radar (SAR) image formation using the Polar Format (PFA) processing algorithm. This is meant to be an aid to those tasked to implement real-time image formation using the Polar Format processing algorithm.

  8. An electrical test system for conductor formation process analysis

    NASA Astrophysics Data System (ADS)

    Estes, T. A.; Rhodes, R. J.

    1994-01-01

    Sandia National Laboratories has designed and built an electrical test system which fulfills a requirement to quickly, accurately, and precisely measure the resistance of conductors formed on Printed Wiring Board (PWB) substrates. This requirement stems from the need to measure small variations in conductors and thus to determine the source of the variations. With this test technology, experiments can be conducted with new materials, equipment, and processes in a timely and scientific manner. Conductor formation processes can be optimized for both conductor yield and uniformity, and process equipment can be fine-tuned prior to processing product to ensure that conductor attributes fulfill requirements. Significant resources were spent by Sandia National Laboratories and Texas Instruments modifying commercially available two-probe testers. AT&T has built a two-probe tester and obtained a commercially available 'bed-of-nails' test system. The two-probe systems have limitations in speed and precision; the 'bed-of-nails' system has proved to be superior to the two-probe designs but is expensive and lacks test pattern flexibility and ease of use. Due to the need to establish a testing technology which meets the requirements of Sandia National Laboratories and the National Center for Manufacturing Sciences PWB Consortium Imaging Team (current Imaging Team members; AT&T, Texas Instruments, AlliedSignal, IBM, and Sandia National Laboratories), a prototype test system was designed and built by Sandia. This paper will discuss the design and performance of the test system and the results of a comparison to other test systems.

  9. An electrical test system for conductor formation process analysis

    SciTech Connect

    Estes, T.A.; Rhodes, R.J.

    1994-03-01

    Sandia National Laboratories has designed and built an electrical test system which fulfills a requirement to quickly, accurately and precisely measure the resistance of conductors formed on Printed Wiring Board (PWB) substrates. This requirement stems from the need to measure small variations in conductors and thus to determine the source of the variations. With this test technology, experiments can be conducted with new materials, equipment, and processes in a timely and scientific manner. Conductor formation processes can be optimized for both conductor yield and uniformity, and process equipment can be fine-tuned prior to processing product to ensure that conductor attributes fulfill requirements. Significant resources have been spent by Sandia National Laboratories and Texas Instruments modifying commercially available two-probe testers. AT&T has built a two-probe tester and obtained a commercially available ``bed-of-nails`` test system. The two-probe systems have limitations in speed and precision; the ``bed-of-nails`` system has proved to be superior to the two-probe designs but is expensive, and lacks test pattern flexibility and ease of use. Due to the need to establish a testing technology which meets the requirements of Sandia National Laboratories and the National Center for Manufacturing Sciences PWB Consortium Imaging Team (current Imaging Team members; AT&T, Texas Instruments, AlliedSignal, IBM, and Sandia National Laboratories), a prototype test system was designed and built by Sandia. This paper will discuss the design and performance of the test system and the results of a comparison to other test systems.

  10. Deciphering Antarctic Intermediate Water Variability during the PLIO-PLEISTOCENE

    NASA Astrophysics Data System (ADS)

    Karas, C.; deMenocal, P. B.; Goldstein, S. L.

    2015-12-01

    Antarctic Intermediate Water (AAIW) plays a fundamental role in the modern global thermohaline circulation because it is the coldwater route from the Southern Hemisphere to the North Atlantic Ocean replacing North Atlantic Deep Water (NADW) (e.g. Oppo and Curry, 2012). Additionally, AAIW is also an important source water in (sub)tropical upwelling regions in the equatorial eastern Pacific and Benguela region (Kubota et al., 2014; Sarmiento et al., 2004). Deciphering AAIW variability through time is critical to understanding its role in global climate change (e.g. Santoso and England, 2004). Our study focuses on reconstructing AAIW during the warm Pliocene (~4 million years ago) and early Pleistocene. This time period marks the transition from warm Pliocene greenhouse conditions towards icehouse conditions, which most likely affected AAIW variability (Karas et al., 2011). To reconstruct changes in AAIW formation, northward extent and possible influence on (sub)tropical upwelling regions, we will use foraminiferal neodymium isotopes (ɛNd) and benthic Mg/Ca from South Atlantic Site 516 and Southwest Pacific Site 1125.

  11. Scale-Free Processes in Galaxy Formation at High Redshift

    NASA Astrophysics Data System (ADS)

    Dekel, Avishai

    2015-08-01

    Key processes of galaxy formation in the Einstein-de Sitter cosmological phase are scale free. For example, 1. The specific accretion rate into dark-matter halos, and that of baryons into the central galaxies, is mass independent and scales as a generic power-law (1+z)^{5/2}. 2. The main-sequence of star-forming galaxies is evolving self-similarly accordingly. Its confinement is determined by generic evolution of galaxies through a sequence of compaction and quenching events. 3. The evolution of the overall gas and stellar content of galaxies can be addressed via a very simple and useful bathtub toy model, which converges to a self-similar quasi-steady-state solution. 4. The spin parameter of the halos, and of the baryons in the galaxy, as built up by streams from the cosmic web, is independent of mass and cosmic time. 5. Counter-rotating streams, self-similar on all scales, may play a major role in generating compaction events and stimulating disk instability. 6. The violent disk instability in the gas-rich high-z galaxies is manifested in a scale-free mass function of clumps. 7. This instability is nonlinear, stimulated by the intense gas inflow into the galaxies, and it may involve scale-free compressive modes of turbulence. These processes are studied using toy models and cosmological simulations.

  12. Deciphering Interactions in Moving Animal Groups

    PubMed Central

    Gautrais, Jacques; Ginelli, Francesco; Fournier, Richard; Blanco, Stéphane; Soria, Marc; Chaté, Hugues; Theraulaz, Guy

    2012-01-01

    Collective motion phenomena in large groups of social organisms have long fascinated the observer, especially in cases, such as bird flocks or fish schools, where large-scale highly coordinated actions emerge in the absence of obvious leaders. However, the mechanisms involved in this self-organized behavior are still poorly understood, because the individual-level interactions underlying them remain elusive. Here, we demonstrate the power of a bottom-up methodology to build models for animal group motion from data gathered at the individual scale. Using video tracks of fish shoal in a tank, we show how a careful, incremental analysis at the local scale allows for the determination of the stimulus/response function governing an individual's moving decisions. We find in particular that both positional and orientational effects are present, act upon the fish turning speed, and depend on the swimming speed, yielding a novel schooling model whose parameters are all estimated from data. Our approach also leads to identify a density-dependent effect that results in a behavioral change for the largest groups considered. This suggests that, in confined environment, the behavioral state of fish and their reaction patterns change with group size. We debate the applicability, beyond the particular case studied here, of this novel framework for deciphering interactions in moving animal groups. PMID:23028277

  13. Cogeneration systems and processes for treating hydrocarbon containing formations

    DOEpatents

    Vinegar, Harold J.; Fowler, Thomas David; Karanikas, John Michael

    2009-12-29

    A system for treating a hydrocarbon containing formation includes a steam and electricity cogeneration facility. At least one injection well is located in a first portion of the formation. The injection well provides steam from the steam and electricity cogeneration facility to the first portion of the formation. At least one production well is located in the first portion of the formation. The production well in the first portion produces first hydrocarbons. At least one electrical heater is located in a second portion of the formation. At least one of the electrical heaters is powered by electricity from the steam and electricity cogeneration facility. At least one production well is located in the second portion of the formation. The production well in the second portion produces second hydrocarbons. The steam and electricity cogeneration facility uses the first hydrocarbons and/or the second hydrocarbons to generate electricity.

  14. Challenges of deciphering gastric cancer heterogeneity

    PubMed Central

    Hudler, Petra

    2015-01-01

    Gastric cancer is in decline in most developed countries; however, it still accounts for a notable fraction of global mortality and morbidity related to cancer. High-throughput methods are rapidly changing our view and understanding of the molecular basis of gastric carcinogenesis. Today, it is widely accepted that the molecular complexity and heterogeneity, both inter- and intra-tumour, of gastric adenocarcinomas present significant obstacles in elucidating specific biomarkers for early detection of the disease. Although genome-wide sequencing and gene expression studies have revealed the intricate nature of the molecular changes that occur in tumour landscapes, the collected data and results are complex and sometimes contradictory. Several aberrant molecules have already been tested in clinical trials, although their diagnostic and prognostic utilities have not been confirmed thus far. The gold standard for the detection of sporadic gastric cancer is still the gastric endoscopy, which is considered invasive. In addition, genome-wide association studies have confirmed that genetic variations are important contributors to increased cancer risk and could participate in the initiation of malignant transformation. This hypothesis could in part explain the late onset of sporadic gastric cancers. The elaborate interplay of polymorphic low penetrance genes and lifestyle and environmental risk factors requires additional research to decipher their relative impacts on tumorigenesis. The purpose of this article is to present details of the molecular heterogeneity of sporadic gastric cancers at the DNA, RNA, and proteome levels and to discuss issues relevant to the translation of basic research data to clinically valuable tools. The focus of this work is the identification of relevant molecular changes that could be detected non-invasively. PMID:26457012

  15. Deciphering Ecohydrological Interactions Using Stable Isotopes

    NASA Astrophysics Data System (ADS)

    McDonnell, J.; Evaristo, J. A.; Jasechko, S.

    2014-12-01

    Deciphering the nature of ecohydrological interconnections and scaling that knowledge gained at single points to watersheds is challenging. One tool that that has proved useful in this regard is stable isotope tracing. Single isotope studies have been used recently to quantify landuse change effects on streamflow source apportionment and ecological effects on transit time distributions of water at the catchment scale. However, most work to date has assumed that plant transpiration, groundwater recharge and streamflow are all sourced or mediated by the same well mixed reservoir—the soil. Recent work in Oregon and Mexico has shown evidence of ecohydrological separation, whereby different subsurface compartmentalized pools of water supply either plant transpiration fluxes or the combined fluxes of groundwater recharge and streamflow. However, these findings have not yet been widely tested. Here we assemble the first dual isotope database for δ2H and δ18O extracted from 47 globally-distributed stable isotopic datasets. We use these data to test the ecohydrological separation hypothesis. We combine this dual isotope dataset with global precipitation, streamwater, groundwater and soil water datasets. Our results show that precipitation, streamwater and groundwater from the 47 sites plot approximately along the δ2H/δ18O slope of eight, suggesting that local precipitation inputs supply streamwater and groundwater. Soil waters extracted from the 47 studies plot below the regression of local streamwater and groundwater with a slope of 6.6±0.05 ‰. Local plant xylem waters from our matched dataset plot on a slope 6.6±0.07 ‰ consistent with local soil waters. The tight association of soil water slopes and not that of local groundwater or streamflow suggests that plants use soil water that does not itself contribute to groundwater recharge or stream water. This ubiquity of subsurface water compartmentalization is surprising and has important implications for how we

  16. Challenges of deciphering gastric cancer heterogeneity.

    PubMed

    Hudler, Petra

    2015-10-01

    Gastric cancer is in decline in most developed countries; however, it still accounts for a notable fraction of global mortality and morbidity related to cancer. High-throughput methods are rapidly changing our view and understanding of the molecular basis of gastric carcinogenesis. Today, it is widely accepted that the molecular complexity and heterogeneity, both inter- and intra-tumour, of gastric adenocarcinomas present significant obstacles in elucidating specific biomarkers for early detection of the disease. Although genome-wide sequencing and gene expression studies have revealed the intricate nature of the molecular changes that occur in tumour landscapes, the collected data and results are complex and sometimes contradictory. Several aberrant molecules have already been tested in clinical trials, although their diagnostic and prognostic utilities have not been confirmed thus far. The gold standard for the detection of sporadic gastric cancer is still the gastric endoscopy, which is considered invasive. In addition, genome-wide association studies have confirmed that genetic variations are important contributors to increased cancer risk and could participate in the initiation of malignant transformation. This hypothesis could in part explain the late onset of sporadic gastric cancers. The elaborate interplay of polymorphic low penetrance genes and lifestyle and environmental risk factors requires additional research to decipher their relative impacts on tumorigenesis. The purpose of this article is to present details of the molecular heterogeneity of sporadic gastric cancers at the DNA, RNA, and proteome levels and to discuss issues relevant to the translation of basic research data to clinically valuable tools. The focus of this work is the identification of relevant molecular changes that could be detected non-invasively. PMID:26457012

  17. Deciphering the Minimal Algorithm for Development and Information-genesis

    NASA Astrophysics Data System (ADS)

    Li, Zhiyuan; Tang, Chao; Li, Hao

    During development, cells with identical genomes acquires different fates in a highly organized manner. In order to decipher the principles underlining development, we used C.elegans as the model organism. Based on a large set of microscopy imaging, we first constructed a ``standard worm'' in silico: from the single zygotic cell to about 500 cell stage, the lineage, position, cell-cell contact and gene expression dynamics are quantified for each cell in order to investigate principles underlining these intensive data. Next, we reverse-engineered the possible gene-gene/cell-cell interaction rules that are capable of running a dynamic model recapitulating the early fate decisions during C.elegans development. we further formulized the C.elegans embryogenesis in the language of information genesis. Analysis towards data and model uncovered the global landscape of development in the cell fate space, suggested possible gene regulatory architectures and cell signaling processes, revealed diversity and robustness as the essential trade-offs in development, and demonstrated general strategies in building multicellular organisms.

  18. Evidence of biogeochemical processes in iron duricrust formation

    NASA Astrophysics Data System (ADS)

    Levett, Alan; Gagen, Emma; Shuster, Jeremiah; Rintoul, Llew; Tobin, Mark; Vongsvivut, Jitraporn; Bambery, Keith; Vasconcelos, Paulo; Southam, Gordon

    2016-11-01

    Canga is a moderately hard iron-rich duricrust primarily composed of goethite as a result of the weathering of banded iron formations. Canga duricrusts lack a well-developed soil profile and consequently form an innate association with rupestrian plants that may become ferruginised, contributing to canga possessing macroscopic biological features. Examination of polished canga using a field emission scanning electron microscope (FE-SEM) revealed the biological textures associated with canga extended to the sub-millimetre scale in petrographic sections and polished blocks. Laminae that formed by abiotic processes and regions where goethite cements were formed in association with microorganisms were observed in canga. Biological cycling of iron within canga has resulted in two distinct forms of microbial fossilisation: permineralisation of multispecies biofilms and mineralisation of cell envelopes. Goethite permineralised biofilms frequently formed around goethite-rich kaolinite grains in close proximity to goethite bands and were composed of micrometre-scale rod-shaped, cocci and filamentous microfossils. In contrast, the cell envelopes immobilised by authigenic iron oxides were primarily of rod-shaped microorganisms, were not permineralised and occurred in pore spaces within canga. Complete mineralisation of intact rod-shaped casts and the absence of permineralisation suggested mineralised cell envelopes may represent fossilised iron-oxidising bacteria in the canga ecosystem. Replication of these iron-oxidising bacteria appeared to infill the porous regions within canga. Synchrotron-based Fourier transform infrared (FTIR) microspectroscopy demonstrated that organic biomarkers were poorly preserved with only weak bands indicative of aliphatic methylene (CH2) associated with permineralised microbial biofilms. High resolution imaging of microbial fossils in canga that had been etched with oxalic acid supported the poor preservation of organic biomarkers within canga

  19. Diagenetic saline formation waters: Their role in crustal processes

    SciTech Connect

    Land, L.S. . Dept. Geology)

    1992-01-01

    Formation waters typical of most sedimentary basins are Bi-rich, Na-Ca-Cl brines. High Cl content is due to halite dissolution and high Ca content to albitization of metastable detrital plagioclase deposited in both sands and shales. High Br content is due to halite recrystallization, especially during deformation, and to the conversion of carnallite to sylvite. Minor elements and isotopes are all controlled by mineral/water reactions. Saline formation waters are thus a normal diagenetic product formed during burial. Diagenetic formation waters constitute a previously unrecognized loop in crustal cycling. Transfer of Li, B, S, Cl, Ca, and Br from sediments to brines, and then discharge of brines back to the ocean, explains why these six elements are depleted in the average igneous crust relative to the average sedimentary crust. Diagenetic saline formation waters are limited in volume only by the availability of sedimentary halite and detrital plagioclase. Thus, the volume of fluids available for MVT-type mineralization and late stage sediment diagenesis is much larger than would be true if formation waters were modified surficial brines. Discharge of saline formation waters from sedimentary basins accounts for efficient chloride cycling (225 Ma residence time in the ocean), and for most of the chloride content of the world's rivers not due to aerosols. Expulsion of large volumes of diagenetic formation waters during tectonism can account for rapid excursions in oceanic chemistry, as in the case of [sup 87]Sr/[sup 86]Sr.

  20. Rapid gas hydrate formation processes: Will they work?

    DOE PAGESBeta

    Brown, Thomas D.; Taylor, Charles E.; Bernardo, Mark P.

    2010-06-07

    Researchers at DOE’s National Energy Technology Laboratory (NETL) have been investigating the formation of synthetic gas hydrates, with an emphasis on rapid and continuous hydrate formation techniques. The investigations focused on unconventional methods to reduce dissolution, induction, nucleation and crystallization times associated with natural and synthetic hydrates studies conducted in the laboratory. Numerous experiments were conducted with various high-pressure cells equipped with instrumentation to study rapid and continuous hydrate formation. The cells ranged in size from 100 mL for screening studies to proof-of-concept studies with NETL’s 15-Liter Hydrate Cell. The results from this work demonstrate that the rapid and continuousmore » formation of methane hydrate is possible at predetermined temperatures and pressures within the stability zone of a Methane Hydrate Stability Curve.« less

  1. Rapid gas hydrate formation processes: Will they work?

    SciTech Connect

    Brown, Thomas D.; Taylor, Charles E.; Bernardo, Mark P.

    2010-06-07

    Researchers at DOE’s National Energy Technology Laboratory (NETL) have been investigating the formation of synthetic gas hydrates, with an emphasis on rapid and continuous hydrate formation techniques. The investigations focused on unconventional methods to reduce dissolution, induction, nucleation and crystallization times associated with natural and synthetic hydrates studies conducted in the laboratory. Numerous experiments were conducted with various high-pressure cells equipped with instrumentation to study rapid and continuous hydrate formation. The cells ranged in size from 100 mL for screening studies to proof-of-concept studies with NETL’s 15-Liter Hydrate Cell. The results from this work demonstrate that the rapid and continuous formation of methane hydrate is possible at predetermined temperatures and pressures within the stability zone of a Methane Hydrate Stability Curve.

  2. Consideration of formation process for the nuclei on precursor

    NASA Astrophysics Data System (ADS)

    Nagata, J.; Okamoto, M.

    2003-12-01

    The very isotropic microwave background and the Hubble expansion indicate that the universe has evolved from an earlier state of high temperature and density that can be reasonably well described by Friedman-Lemaitre-Robertson-Walker cosmological models. The nuclear evolution of non-degenerate matter expanding from very high temperature was studied in detail for various values of the expansion rate and of the proton-neutron abundance difference and baryon density[1,2,3]. In this calculation, many nuclear reactions were included, and its results suggested important reaction process for the evolution of nuclear abundances. 3He and 4He are very important elements in these nuclear reactions as the primordial nucleosynthesis. Microscopic study for few body system is one main topic in nuclear theoretical physics. In this field, very accurate calculations are available by using the Faddeev equations[4]. Recently, many data for pd, p-3He and d-3He have been obtained including polarized observables. Model calculations for systems including 3He and 4He (for example, d + 3He -> p + 4He) are carried out using the Faddeev equations based on the meson exchange models[4]. This model reproduces well the empirical phase shifts which are determined by so-called phase-shift analyses using all of available scattering data measured at various laboratories around the world[5,6,7]. Constructions of models for the nuclear reactions including 3He and 4He will give important information for calculations of the primordial nucleosynthesis after big-ban. The calculations are carried out until the sum of the abundances at each mass number ceases to change. Various different set of initial conditions for the baryon mass density, the expansion rate and the neutron-proton ratio are used. Dusts kept in precursor asteroid nebular form precursor asteroid, then, formations of planet start [8]. Possible values of parameters in the initial conditions for theoretical calculations will be searched

  3. Formation and Processing of Organics in the Early Solar System

    NASA Astrophysics Data System (ADS)

    Kerridge, John F.

    1999-10-01

    Until pristine samples can be returned from cometary nuclei, primitive meteorites represent our best source of information about organic chemistry in the early solar system. However, this material has been affected by secondary processing on asteroidal parent bodies which probably did not affect the material now present in cometary nuclei. Production of meteoritic organic matter apparently involved the following sequence of events: Molecule formation by a variety of reaction pathways in dense interstellar clouds; Condensation of those molecules onto refractory interstellar grains; Irradiation of organic-rich interstellar-grain mantles producing a range of molecular fragments and free radicals; Inclusion of those interstellar grains into the protosolar nebula with probable heating of at least some grain mantles during passage through the shock wave bounding the solar accretion disc; Agglomeration of residual interstellar grains and locally produced nebular condensates into asteroid-sized planetesimals; Heating of planetesimals by decay of extinct radionuclides; Melting of ice to produce liquid water within asteroidal bodies; Reaction of interstellar molecules, fragments and radicals with each other and with the aqueous environment, possibly catalysed by mineral grains; Loss of water and other volatiles to space yielding a partially hydrated lithology containing a complex suite of organic molecules; Heating of some of this organic matter to generate a kerogen-like complex; Mixing of heated and unheated material to yield the meteoritic material now observed. Properties of meteoritic organic matter believed to be consistent with this scenario include: Systematic decrease of abundance with increasing C number in homologous series of characterisable molecules; Complete structural diversity within homologous series; Predominance of branched-chain isomers; Considerable isotopic variability among characterisable molecules and within kerogen-like material; Substantial

  4. Formation and processing of organics in the early solar system.

    PubMed

    Kerridge, J F

    1999-01-01

    Until pristine samples can be returned from cometary nuclei, primitive meteorites represent our best source of information about organic chemistry in the early solar system. However, this material has been affected by secondary processing on asteroidal parent bodies which probably did not affect the material now present in cometary nuclei. Production of meteoritic organic matter apparently involved the following sequence of events: Molecule formation by a variety of reaction pathways in dense interstellar clouds; Condensation of those molecules onto refractory interstellar grains; Irradiation of organic-rich interstellar-grain mantles producing a range of molecular fragments and free radicals; Inclusion of those interstellar grains into the protosolar nebula with probable heating of at least some grain mantles during passage through the shock wave bounding the solar accretion disc; Agglomeration of residual interstellar grains and locally produced nebular condensates into asteroid-sized planetesimals; Heating of planetesimals by decay of extinct radionuclides; Melting of ice to produce liquid water within asteroidal bodies; Reaction of interstellar molecules, fragments and radicals with each other and with the aqueous environment, possibly catalysed by mineral grains; Loss of water and other volatiles to space yielding a partially hydrated lithology containing a complex suite of organic molecules; Heating of some of this organic matter to generate a kerogen-like complex; Mixing of heated and unheated material to yield the meteoritic material now observed. Properties of meteoritic organic matter believed to be consistent with this scenario include: Systematic decrease of abundance with increasing C number in homologous series of characterisable molecules; Complete structural diversity within homologous series; Predominance of branched-chain isomers; Considerable isotopic variability among characterisable molecules and within kerogen-like material; Substantial

  5. Heating hydrocarbon containing formations in a checkerboard pattern staged process

    SciTech Connect

    de Rouffignac, Eric Pierre; Pingo-Almada, Monica M; Miller, David Scott

    2009-06-02

    Method for treating a hydrocarbon containing formation are described herein. Methods may include providing heat to two or more first sections of the formation with one or more first heaters in two or more of the first sections. The provided heat may mobilize first hydrocarbons in two or more of the first sections. At least some of the mobilized first hydrocarbons are produced through production wells located in two or more second sections of the formation. The first sections and the second sections are arranged in a checkerboard pattern. A portion of at least one of the second sections proximate at least one production well is provided some heat from the mobilized first hydrocarbons, but is not conductively heated by heat from the first heaters. Heat may be provided to the second sections with one or more second heaters in the second sections to further heat the second sections.

  6. Heating hydrocarbon containing formations in a line drive staged process

    DOEpatents

    Miller, David Scott

    2009-07-21

    Method for treating a hydrocarbon containing formation are described herein. Methods may include providing heat to a first section of the formation with one or more first heaters in the first section. First hydrocarbons may be heated in the first section such that at least some of the first hydrocarbons are mobilized. At least some of the mobilized first hydrocarbons may be produced through a production well located in a second section of the formation. The second section may be located substantially adjacent to the first section. A portion of the second section may be provided some heat from the mobilized first hydrocarbons, but is not conductively heated by heat from the first heaters. Heat may be provided to the second section with one or more second heaters in the second section to further heat the second section.

  7. Pyruvate Formate Lyase Acts as a Formate Supplier for Metabolic Processes during Anaerobiosis in Staphylococcus aureus▿

    PubMed Central

    Leibig, Martina; Liebeke, Manuel; Mader, Diana; Lalk, Michael; Peschel, Andreas; Götz, Friedrich

    2011-01-01

    Previous studies demonstrated an upregulation of pyruvate formate lyase (Pfl) and NAD-dependent formate dehydrogenase (Fdh) in Staphylococcus aureus biofilms. To investigate their physiological role, we constructed fdh and pfl deletion mutants (Δfdh and Δpfl). Although formate dehydrogenase activity in the fdh mutant was lost, it showed little phenotypic alterations under oxygen-limited conditions. In contrast, the pfl mutant displayed pleiotropic effects and revealed the importance of formate production for anabolic metabolism. In the pfl mutant, no formate was produced, glucose consumption was delayed, and ethanol production was decreased, whereas acetate and lactate production were unaffected. All metabolic alterations could be restored by addition of formate or complementation of the Δpfl mutant. In compensation reactions, serine and threonine were consumed better by the Δpfl mutant than by the wild type, suggesting that their catabolism contributes to the refilling of formyl-tetrahydrofolate, which acts as a donor of formyl groups in, e.g., purine and protein biosynthesis. This notion was supported by reduced production of formylated peptides by the Δpfl mutant compared to that of the parental strain, as demonstrated by weaker formyl-peptide receptor 1 (FPR1)-mediated activation of leukocytes with the mutant. FPR1 stimulation could also be restored either by addition of formate or by complementation of the mutation. Furthermore, arginine consumption and arc operon transcription were increased in the Δpfl mutant. Unlike what occurred with the investigated anaerobic conditions, a biofilm is distinguished by nutrient, oxygen, and pH gradients, and we thus assume that Pfl plays a significant role in the anaerobic layer of a biofilm. Fdh might be critical in (micro)aerobic layers, as formate oxidation is correlated with the generation of NADH/H+, whose regeneration requires respiration. PMID:21169491

  8. BATHYMETRIC IRREGULARITIES, JET FORMATION, AND SUBSEQUENT MIXING PROCESSES

    EPA Science Inventory

    It is well known that bathymetric contours influence and steer currents and that irregularities in bathymetry contribute to the formation of aquatic non-buoyant jets and buoyant plumes. For example, bathymetric irregularities can channel flow through canyons or accelerate flow ov...

  9. Well completion process for formations with unconsolidated sands

    DOEpatents

    Davies, David K.; Mondragon, III, Julius J.; Hara, Philip Scott

    2003-04-29

    A method for consolidating sand around a well, involving injecting hot water or steam through well casing perforations in to create a cement-like area around the perforation of sufficient rigidity to prevent sand from flowing into and obstructing the well. The cement area has several wormholes that provide fluid passageways between the well and the formation, while still inhibiting sand inflow.

  10. Core Formation Under Dynamic Conditions: Physical Processes and Geochemical Signatures

    NASA Technical Reports Server (NTRS)

    Rushmer, T.; Gaetani, G.; Jones, J. H.; Sparks, J.

    2001-01-01

    We have experimentally investigated liquid metal segregation from a solid silicate matrix under conditions of applied stress. Liquid moves in fractures and formation of fayalitic olivine from orthopyroxene by migrating Fe-Ni-S-O liquids is observed. Additional information is contained in the original extended abstract.

  11. Single molecule image formation, reconstruction and processing: introduction.

    PubMed

    Ashok, Amit; Piestun, Rafael; Stallinga, Sjoerd

    2016-07-01

    The ability to image at the single molecule scale has revolutionized research in molecular biology. This feature issue presents a collection of articles that provides new insights into the fundamental limits of single molecule imaging and reports novel techniques for image formation and analysis. PMID:27409708

  12. Optically thin ice clouds in Arctic; Formation processes

    NASA Astrophysics Data System (ADS)

    Jouan, Caroline; Pelon, Jacques; Girard, Eric; Blanchet, Jean-Pierre; Wobrock, Wolfram; Gayet, Jean-Franćois; Schwarzenböck, Alfons; Gultepe, Ismail; Delanoë, Julien; Mioche, Guillaume

    2010-05-01

    Arctic ice cloud formation during winter is poorly understood mainly due to lack of observations and the remoteness of this region. Yet, their influence on Northern Hemisphere weather and climate is of paramount importance, and the modification of their properties, linked to aerosol-cloud interaction processes, needs to be better understood. Large concentration of aerosols in the Arctic during winter is associated to long-range transport of anthropogenic aerosols from the mid-latitudes to the Arctic. Observations show that sulphuric acid coats most of these aerosols. Laboratory and in-situ measurements show that at cold temperature (< -30°C), acidic coating lowers the freezing point and deactivates ice nuclei (IN). Therefore, the IN concentration is reduced in these regions and there is less competition for the same available moisture. As a result, large ice crystals form in relatively small concentrations. It is hypothesized that the observed low concentration of large ice crystals in thin ice clouds is linked to the acidification of aerosols. To check this, it is necessary to analyse cloud properties in the Arctic. Extensive measurements from ground-based sites and satellite remote sensing (CloudSat and CALIPSO) reveal the existence of two types of extended optically thin ice clouds (TICs) in the Arctic during the polar night and early spring. The first type (TIC-1) is seen only by the lidar, but not the radar, and is found in pristine environment whereas the second type (TIC-2) is detected by both sensors, and is associated with high concentration of aerosols, possibly anthropogenic. TIC-2 is characterized by a low concentration of ice crystals that are large enough to precipitate. To further investigate the interactions between TICs clouds and aerosols, in-situ, airborne and satellite measurements of specific cases observed during the POLARCAT and ISDAC field experiments are analyzed. These two field campaigns took place respectively over the North Slope of

  13. Optically thin ice clouds in Arctic : Formation processes

    NASA Astrophysics Data System (ADS)

    Jouan, C.; Girard, E.; Pelon, J.; Blanchet, J.; Wobrock, W.; Gultepe, I.; Gayet, J.; Delanoë, J.; Mioche, G.; Adam de Villiers, R.

    2010-12-01

    Arctic ice cloud formation during winter is poorly understood mainly due to lack of observations and the remoteness of this region. Their influence on Northern Hemisphere weather and climate is of paramount importance, and the modification of their properties, linked to aerosol-cloud interaction processes, needs to be better understood. Large concentration of aerosols in the Arctic during winter is associated to long-range transport of anthropogenic aerosols from the mid-latitudes to the Arctic. Observations show that sulphuric acid coats most of these aerosols. Laboratory and in-situ measurements show that at cold temperature (<-30°C), acidic coating lowers the freezing point and deactivates ice nuclei (IN). Therefore, the IN concentration is reduced in these regions and there is less competition for the same available moisture. As a result, large ice crystals form in relatively small concentrations. It is hypothesized that the observed low concentration of large ice crystals in thin ice clouds is linked to the acidification of aerosols. Extensive measurements from ground-based sites and satellite remote sensing (CloudSat and CALIPSO) reveal the existence of two types of extended optically thin ice clouds (TICs) in the Arctic during the polar night and early spring. The first type (TIC-1) is seen only by the lidar, but not the radar, and is found in pristine environment whereas the second type (TIC-2) is detected by both sensors, and is associated with high concentration of aerosols, possibly anthropogenic. TIC-2 is characterized by a low concentration of ice crystals that are large enough to precipitate. To further investigate the interactions between TICs clouds and aerosols, in-situ, airborne and satellite measurements of specific cases observed during the POLARCAT and ISDAC field experiments are analyzed. These two field campaigns took place respectively over the North Slope of Alaska and Northern part of Sweden in April 2008. Analysis of cloud type can be

  14. Process for biological material carbon-carbon bond formation

    DOEpatents

    Hollingsworth, Rawle I.; Jung, Seunho; Mindock, Carol A.

    1998-01-01

    A process for providing vicinal dimethyl long chain between alkyl groups of organic compounds is described. The process uses intact or disrupted cells of various species of bacteria, particularly Thermoanaerobacter sp., Sarcina sp. and Butyrivibrio sp. The process can be conducted in an aqueous reaction mixture at room temperatures.

  15. Process for biological material carbon-carbon bond formation

    DOEpatents

    Hollingsworth, R.I.; Jung, S.; Mindock, C.A.

    1998-12-22

    A process for providing vicinal dimethyl long chain between alkyl groups of organic compounds is described. The process uses intact or disrupted cells of various species of bacteria, particularly Thermoanaerobacter sp., Sarcina sp. and Butyrivibrio sp. The process can be conducted in an aqueous reaction mixture at room temperatures. 8 figs.

  16. Tool and process for stimulating a subterranean formation

    SciTech Connect

    Trost, S.A.

    1989-01-17

    A tool is described for stimulating a subterranean formation comprising, an elongate propellant stack constructed from propellant material modules that are formed from a combination of propellant materials such that the propellant module combination will have a desired burn rate, propellant modules of a center portion to have identical convex and concave surfaces as the respective top and bottom faces thereof with end propellant modules to form the propellant stack ends each having an end face to fit within or over one of the center portion propellant modules convex or concave faces; adhesive means containing grains of a propellant or explosive mixed therein to provide a burn rate that is approximately that of the propellant stack for bonding the selected propellant modules together, the adhesive means to burn with the propellant stack; means for supporting and lowering the propellant stack into a well bore to a subterranean formation to be stimulated; and means for igniting the propellant stack.

  17. Two contemporaneous processes of volcanic ash formation at Stromboli volcano, Italy

    NASA Astrophysics Data System (ADS)

    Kueppers, Ulrich; Andronico, Daniele; Taddeucci, Jacopo

    2014-05-01

    Explosive volcanic eruptions involve the fragmentation and ejection of pyroclasts. Volcanic ash is the smallest grain size fraction and can be generated by a plethora of processes inside the conduit, during the rise of the gas-particle mixture in the conduit or the eruption column as well as during the (sub)-horizontal transport before final deposition. Volcanic deposits are commonly used to infer for fragmentation and emplacement processes. Different fragmentation modes, eruption styles and emplacement dynamics can be deciphered. Additionally, the characterisation of clasts of different types is used to infer for the ratio of fresh magma to older/altered lava or significantly older country rocks. During a 10 days observation period in May 2013, The North-East Crater of Stromboli volcano (Italy) showed weak explosive eruptions every 10-30 minutes that emitted incandescent blocks and lapilli to heights of up to 200 m above the crater as well as large amounts of black scoriaceous ash. The larger clasts were landing in the vicinity of the crater and continued rolling down the Sciara del Fuoco. Immediately upon impact, light brown ash was lofted by the rolling blocks and dispersed by the wind. These two kinds of primary volcanic ash were deposited together. The black ash is more angular and generally exhibits a higher porosity (magma with the highest porosity) whereas the brown ash (abrasion of rolling lapilli and bombs) can be significantly denser. This quasi-contemporaneous generation of fresh volcanic ash by two distinctly different processes has to be taken into consideration when discerning the ratio of juvenile/lithic components at explosive volcanoes.

  18. Text Processing and Formatting: Composure, Composition and Eros.

    ERIC Educational Resources Information Center

    Blair, John C., Jr.

    1984-01-01

    Review of computer software offering text editing/processing capabilities highlights work habits, elements of computer style and composition, buffers, the CRT, line- and screen-oriented text editors, video attributes, "swapping,""cache" memory, "disk emulators," text editing versus text processing, and UNIX operating system. Specific programs…

  19. Star formation and cosmic massive black hole formation, a universal process organized by angular momenta

    SciTech Connect

    Colgate, S. A.

    2004-01-01

    It is suggested that star formation is organized following the same principles as we have applied in a recent explanation of galaxy and massive black hole formation. In this scenario angular momentum is randomly distributed by tidal torquing among condensations, Lyman-{alpha} clouds or cores for star formation during the initial non-linear phase of collapse. This angular momentum is characterized by the parameter, {lambda}, the ratio of the angular momentum of the cloud to that of a Keplerian orbit with the same central mass and radius. This parameter is calculated in very many simulations of structure formation of the universe as well as core formation and appears to be universal and independent of any scale. The specific angular momentum during the collapse of every cloud is locally conserved and universally produces a near flat rotation curve M{sub formation of a flat rotation curve (protostellar) disk of mass M{sub dsk} {sup -}30 M{sub o} of radius R{sub dsk} {approx_equal} 1100 AU or 5.4 x 10{sup -3} pc. In such a disk {Sigma} {proportional_to} 1/R and reaches the RVI condition at R{sub crit} {approx_equal} 40 AU where M{sub

  20. Transition and separation process in brine channels formation

    NASA Astrophysics Data System (ADS)

    Berti, Alessia; Bochicchio, Ivana; Fabrizio, Mauro

    2016-02-01

    In this paper, we discuss the formation of brine channels in sea ice. The model includes a time-dependent Ginzburg-Landau equation for the solid-liquid phase change, a diffusion equation of the Cahn-Hilliard kind for the solute dynamics, and the heat equation for the temperature change. The macroscopic motion of the fluid is also considered, so the resulting differential system couples with the Navier-Stokes equation. The compatibility of this system with the thermodynamic laws and a maximum theorem is proved.

  1. Process for recovering hydrocarbons from a hydrocarbon-bearing formation

    SciTech Connect

    Alston, R.B.; Braden, W.B.; Flournoy, K.H.

    1980-03-11

    A method is described for transporting heavy crude oil through a pipeline which involves introducing into a pipeline or well-bore with the viscous hydrocarbons an aqueous solution containing (1) a sulfonate surfactant, (2) a rosin soap or a naphthenic acid soap and, optionally (3) coupling agent whereby there is spontaneously formed a low viscosity, salt tolerant, oil-in-water emulsion. Also disclosed is a method of recovery of hydrocarbons from a hydrocarbon bearing formation employing an aqueous solution containing (1) a sulfonate surfactant, (2) a rosin soap or a naphthenic acid soap and, optionally (3) a coupling agent.

  2. Core Formation Process and Light Elements in the Planetary Core

    NASA Astrophysics Data System (ADS)

    Ohtani, E.; Sakairi, T.; Watanabe, K.; Kamada, S.; Sakamaki, T.; Hirao, N.

    2015-12-01

    Si, O, and S are major candidates for light elements in the planetary core. In the early stage of the planetary formation, the core formation started by percolation of the metallic liquid though silicate matrix because Fe-S-O and Fe-S-Si eutectic temperatures are significantly lower than the solidus of the silicates. Therefore, in the early stage of accretion of the planets, the eutectic liquid with S enrichment was formed and separated into the core by percolation. The major light element in the core at this stage will be sulfur. The internal pressure and temperature increased with the growth of the planets, and the metal component depleted in S was molten. The metallic melt contained both Si and O at high pressure in the deep magma ocean in the later stage. Thus, the core contains S, Si, and O in this stage of core formation. Partitioning experiments between solid and liquid metals indicate that S is partitioned into the liquid metal, whereas O is weakly into the liquid. Partitioning of Si changes with the metallic iron phases, i.e., fcc iron-alloy coexisting with the metallic liquid below 30 GPa is depleted in Si. Whereas hcp-Fe alloy above 30 GPa coexisting with the liquid favors Si. This contrast of Si partitioning provides remarkable difference in compositions of the solid inner core and liquid outer core among different terrestrial planets. Our melting experiments of the Fe-S-Si and Fe-O-S systems at high pressure indicate the core-adiabats in small planets, Mercury and Mars, are greater than the slope of the solidus and liquidus curves of these systems. Thus, in these planets, the core crystallized at the top of the liquid core and 'snowing core' formation occurred during crystallization. The solid inner core is depleted in both Si and S whereas the liquid outer core is relatively enriched in Si and S in these planets. On the other hand, the core adiabats in large planets, Earth and Venus, are smaller than the solidus and liquidus curves of the systems. The

  3. Formative Assessment: A Systematic and Artistic Process of Instruction for Supporting School and Lifelong Learning

    ERIC Educational Resources Information Center

    Clark, Ian

    2012-01-01

    Formative assessment is a potentially powerful instructional process because the practice of sharing assessment information that supports learning is embedded into the instructional process by design. If the potential of formative assessment is to be realized, it must transform from a collection of abstract theories and research methodologies and…

  4. Effect of channel plane form on formation process of Sandbars

    NASA Astrophysics Data System (ADS)

    Takahashi, Gen; Yasuda, Hiroyasu

    Almost no explanation is given about development process of sand bar in non-straighten channel because the phenomenon of sand bar has been investigated using straighten channel. This study conducted a numerical experiment of development process of sand bar in a meandering channel and a figure-of-eight(gourd) as fixed wall. The results shows that the development process clearly differs in channel of straighten, meandering and figure-of-eight(gourd). The result of figure-of-eight(gourd) doesn't occur mode degradation and keep multiple bars.

  5. Colloidal crystal formation: nano-dewetting and the assembly process

    NASA Astrophysics Data System (ADS)

    Marlow, Frank; Muldarisnur, Mulda

    2016-04-01

    Self-assembly of colloidal particles is a promising approach for fabrication of three-dimensional periodic structures which are especially interesting for photonic crystals. This approach is simple and cheap, but it still suffers under the existence of many intrinsic defects. The efforts to improve the self-assembly process have led to many deposition methods with a different degree of controllability. One of the best fabrication techniques is the capillary deposition method leading to non-scattered photon propagation in the order of 80 μm. To improve understanding of the selfassembly process we investigate the stages of the process separately. The most important stage is likely the deposition of suspended particles into a dense arrangement forming a crystal. This is studied spectroscopically. Another crucial stage is the drying of colloidal crystal which is connected with a continuous shrinkage process. Several minutes after starting the drying, a surprise occurs: The system expands shortly before it shrinks monotonously until reaching its final state after about one day. We called this "v"-event because of the characteristic shape of the curve for the Bragg peak. The event is assigned to the start of a nano-dewetting process occurring at the colloidal particles.

  6. Chondritic Meteorites: Nebular and Parent-Body Formation Process

    NASA Technical Reports Server (NTRS)

    Rubin, Alan E.

    1997-01-01

    Chondritic meteorites are the products of condensation, agglomeration and accretion of material in the solar nebula; these objects are the best sources of information regarding processes occurring during the early history of the solar system. We obtain large amounts of high-quality chemical and petrographic data and use them to infer chemical fractionation processes that occurred in the solar nebula and on meteorite parent bodies during thermal metamorphism, shock metamorphism and aqueous alteration. We compare diverse groups of chondrites and model their different properties in terms of processes that differed at different nebular locations or on different parent-bodies. In order to expand our set of geochemically important elements (particularly Si, C, P and S) and to distinguish the different oxidation states of Fe, Greg Kallemeyn spent three months (1 Sept. - 30 Nov. 1995) at the Smithsonian Institution to learn Eugene Jarosewich's wet chemical techniques. Key specimens from the recently established CK, CR and R chondrite groups were analyzed.

  7. Modeling of formation of deposited layer by plasma spray process

    NASA Astrophysics Data System (ADS)

    Lee, Joo-Dong; Ra, Hyung-Yong; Hong, Kyung-Tae; Hur, Sung-Kang

    1992-03-01

    An analytical model is developed to describe the plasma deposition process in which average solidified thickness and coating and substrate temperatures are obtained. During the deposition process, the solidification rate is periodically varied, due to the impingement of liquid splats, and the amount of liquid in the coating layer increases. Periodical variation of the solidification rate causes temperature fluctuation in coating and substrate. The nature of interfacial structure of plasma-sprayed NiCrBSi MA powder is compared with the result predicted using the model, which indicates that the liquid deposited at the coating surface during deposition causes discontinuous boundaries within the coating. The spraying rate and the solidification rate reverse periodically with spraying process.

  8. Chondritic Meteorites: Nebular and Parent-Body Formation Processes

    NASA Technical Reports Server (NTRS)

    Rubin, Alan E.; Lindstrom, David (Technical Monitor)

    2002-01-01

    It is important to identify features in chondrites that formed as a result of parent-body modification in order to disentangle nebular and asteroidal processes. However, this task is difficult because unmetamorphosed chondritic meteorites are mixtures of diverse components including various types of chondrules, chondrule fragments, refractory and mafic inclusions, metal-sulfide grains and fine-grained matrix material. Shocked chondrites can contain melt pockets, silicate-darkened material, metal veins, silicate melt veins, and impact-melt-rock clasts. This grant paid for several studies that went far in helping to distinguish primitive nebular features from those produced during asteroidal modification processes.

  9. Modified Process For Formation Of Silicon Carbide Matrix Composites

    NASA Technical Reports Server (NTRS)

    Behrendt, Donald R.; Singh, Mrityunjay

    1996-01-01

    Modified version of process for making SiC-fiber/SiC-matrix composite material reduces damage to SiC (SCS-6) fibers and to carbon-rich coatings on fibers. Modification consists of addition of second polymer-infiltration-and-pyrolysis step to increase carbon content of porous matrix before infiltration with liquid silicon or silicon alloy.

  10. Particle contamination formation and detection in magnetron sputtering processes

    SciTech Connect

    Selwyn, G.S.; Weiss, C.A.; Sequeda, F.; Huang, C.

    1996-10-01

    Defects caused by particulate contamination are an important concern in the fabrication of thin film products. Often, magnetron sputtering processes are used for this purpose. Particle contamination can cause electrical shorting, pin holes, problems with photolithography, adhesion failure, as well as visual and cosmetic defects. Particle contamination generated during thin film processing can be detected using laser light scattering, a powerful diagnostic technique that provides real-time, {ital in-situ} imaging of particles > 0.3 {mu}m in diameter. Using this technique, the causes, sources and influences on particles in plasma and non-plasma and non-plasma processes may be independently evaluated and corrected. Several studies employing laser light scattering have demonstrated both homogeneous and heterogeneous causes of particle contamination. In this paper, we demonstrate that the mechanisms for particle generation, transport and trapping during magnetron sputter deposition are different from the mechanisms reported in previously studied plasma etch processes. During magnetron sputter deposition, one source of particle contamination is linked to portions of the sputtering target surface exposed to weaker plasma density. In this region, film redeposition is followed by filament or nodule growth and enhanced trapping which increases filament growth. Eventually the filaments effectively ``short circuit`` the sheath, causing high currents to flow through these features. This, in turn, causes heating failure of the filament fracturing and ejecting the filaments into the plasma and onto the substrate. Evidence of this effect has been observed in semiconductor (IC) fabrication and storage disk manufacturing. Discovery of this mechanism in both technologies suggests that this mechanism may be universal to many sputtering processes.

  11. Radical formation, chemical processing, and explosion of interstellar grains

    NASA Technical Reports Server (NTRS)

    Greenberg, J. M.

    1976-01-01

    The ultraviolet radiation in interstellar space is shown to create a sufficient steady-state density of free radicals in the grain mantle material consisting of oxygen, carbon, nitrogen, and hydrogen to satisfy the critical condition for initiation of chain reactions. The criterion for minimum critical particle size for maintaining the chain reaction is of the order of the larger grain sizes in a distribution satisfying the average extinction and polarization measures. The triggering of the explosion of interstellar grains leading to the ejection of complex interstellar molecules is shown to be most probable where the grains are largest and where radiation is suddenly introduced; i.e., in regions of new star formation. Similar conditions prevail at the boundaries between very dark clouds and H II regions. When the energy released by the chemical activity of the free radicals is inadequate to explode the grain, the resulting mantle material must consist of extremely large organic molecules which are much more resistant to the hostile environment of H II regions than the classical dirty-ice mantles made up of water, methane, and ammonia.

  12. Formative Processes Governing Ross Sea Polynya Areal Variability

    NASA Astrophysics Data System (ADS)

    Ward, J. M.

    2014-12-01

    Of the 17 million km^2 of sea ice in the Southern Ocean, ~10% is generated through coastal polynyal systems. The largest and greatest contributor to sea ice formation in the Antarctic is the Ross Sea Polynya which exists in a region where sea ice trends are positive and significant. Understanding polynya areal dynamics and the contributing physical factors will give further insight into the future of Ross Sea ice production. Previous studies have established coastal winds and surface temperatures as key contributors to the development and maintenance of coastal polynyas. However, much that is understood is based on physically sound inference. While the influence of these variables have been studied separately, their concerted roles have not been quantified, neither has any indication of their variation with time been established. Automatic weather station data produced by the Antarctic Automatic Weather Station Program was acquired from the National Oceanic and Atmospheric Administration, and polynya area data was produced through the application of the Polynya Signature Simulation Method onto Special Sensor Microwave Imager input acquired from the National Snow and Ice Data Center. Wind speed, wind direction, sea surface temperature, near surface air temperature, oceanic temperature, and tidal fluctuations are examined as physically significant contributors to polynya areal variability and are considered in a multivariate regression model at a 95% confidence level. This study quantifies the degree to which each variable contributes to Ross Sea Polynya areal dynamics, and determines how their influences vary seasonally and in the long term.

  13. Texture formation in bulk iron processed by simple shear

    SciTech Connect

    Gibbs, M.A.; Hartwig, K.T.; Cornwell, L.R.; Goforth, R.E.; Payzant, E.A.

    1998-11-13

    The preferred orientation of grains in iron after conventional deformation by cold rolling or drawing is characterized as sheet or fiber texture respectively. The main texture component in the rolling direction is [110](001). For the case of wire drawing, again, the [110] direction aligns with the wire axis. A novel method of straining materials called equal channel angular extrusion (ECAE), has recently been developed. This new processing method has the capability of introducing large amounts of plastic strain into bulk material in a relatively uniform manner without a reduction in workpiece cross-section. The processing concept is elegant; press a block of solid material through a constant cross-section tunnel composed of two intersecting channels. The purpose of the work reported here is to determine which kinds of texture are developed by three basic schemes of multipass ECAE. The schemes examined include what are termed route A, route B and route C. Route A maintains the same orientation of the shear plane and shear direction relative to the extrusion direction during all extrusions. Route B involves rotating the billet +90{degree} about the extrusion direction before each even numbered extrusion and {minus}90{degree} before each odd numbered extrusion. Route C processing includes an even number of extrusion passes with a +180{degree} or {minus}180{degree} rotation of the workpiece around the extrusion direction before each extrusion. Conventional sheet and fiber textures can be developed in bulk iron by using multipass ECAE processing. A shear texture results after a single extrusion. Multipass extrusions that return structural elements to their original shape after an even number of passes result in a texture that shows characteristics of both shear and the original texture.

  14. Thermoplastic processing of proteins for film formation--a review.

    PubMed

    Hernandez-Izquierdo, V M; Krochta, J M

    2008-03-01

    Increasing interest in high-quality food products with increased shelf life and reduced environmental impact has encouraged the study and development of edible and/or biodegradable polymer films and coatings. Edible films provide the opportunity to effectively control mass transfer among different components in a food or between the food and its surrounding environment. The diversity of proteins that results from an almost limitless number of side-chain amino-acid sequential arrangements allows for a wide range of interactions and chemical reactions to take place as proteins denature and cross-link during heat processing. Proteins such as wheat gluten, corn zein, soy protein, myofibrillar proteins, and whey proteins have been successfully formed into films using thermoplastic processes such as compression molding and extrusion. Thermoplastic processing can result in a highly efficient manufacturing method with commercial potential for large-scale production of edible films due to the low moisture levels, high temperatures, and short times used. Addition of water, glycerol, sorbitol, sucrose, and other plasticizers allows the proteins to undergo the glass transition and facilitates deformation and processability without thermal degradation. Target film variables, important in predicting biopackage performance under various conditions, include mechanical, thermal, barrier, and microstructural properties. Comparisons of film properties should be made with care since results depend on parameters such as film-forming materials, film formulation, fabrication method, operating conditions, testing equipment, and testing conditions. Film applications include their use as wraps, pouches, bags, casings, and sachets to protect foods, reduce waste, and improve package recyclability. PMID:18298745

  15. Formation and Degradation of Beta-casomorphins in Dairy Processing

    PubMed Central

    Nguyen, Duc Doan; Johnson, Stuart Keith; Busetti, Francesco; Solah, Vicky Ann

    2015-01-01

    Milk proteins including casein are sources of peptides with bioactivity. One of these peptides is beta-casomorphin (BCM) which belongs to a group of opioid peptides formed from β-casein variants. Beta-casomorphin 7 (BCM7) has been demonstrated to be enzymatically released from the A1 or B β-casein variant. Epidemiological evidence suggests the peptide BCM 7 is a risk factor for development of human diseases, including increased risk of type 1 diabetes and cardiovascular diseases but this has not been thoroughly substantiated by research studies. High performance liquid chromatography coupled to UV-Vis and mass spectrometry detection as well as enzyme–linked immunosorbent assay (ELISA) has been used to analyze BCMs in dairy products. BCMs have been detected in raw cow's milk and human milk and a variety of commercial cheeses, but their presence has yet to be confirmed in commercial yoghurts. The finding that BCMs are present in cheese suggests they could also form in yoghurt, but be degraded during yoghurt processing. Whether BCMs do form in yoghurt and the amount of BCM forming or degrading at different processing steps needs further investigation and possibly will depend on the heat treatment and fermentation process used, but it remains an intriguing unknown. PMID:25077377

  16. The Q, Compound Q is Finally Deciphered

    PubMed Central

    Bhagi-Damodaran, Ambika; Lu, Yi

    2015-01-01

    Methane monooxygenases (MMOs) activate the high energy C-H bond of methane and convert it to methanol with high selectivity and under physiological conditions. Despite decades of efforts focusing on elucidating the structure, function and mechanism of soluble MMOs, the structure of a key intermediate (called compound Q) remained unknown. This article highlights a recent report by Banerjee et. al. which not only firmly establishes the core-structure of Q, but also provides significant insight into its formation, reaction with methane and eventual decay. PMID:26346336

  17. Deciphering skeletal patterning: clues from the limb.

    PubMed

    Mariani, Francesca V; Martin, Gail R

    2003-05-15

    Even young children can distinguish a Tyrannosaurus rex from a Brontosaurus by observing differences in bone size, shape, number and arrangement, that is, skeletal pattern. But despite our extensive knowledge about cartilage and bone formation per se, it is still largely a mystery how skeletal pattern is established. Much of what we do know has been learned from studying limb development in chicken and mouse embryos. Based on the data from such studies, models for how limb skeletal pattern is established have been proposed and continue to be hotly debated. PMID:12748649

  18. Secondary organic aerosol formation through fog processing of VOCs

    NASA Astrophysics Data System (ADS)

    Herckes, P.; Hutchings, J. W.

    2010-07-01

    Volatile Organic Compounds (VOCs) including benzene, toluene, ethylbenzene and xylenes (BTEX) have been determined in highly concentrated amounts (>1 ug/L) in intercepted clouds in northern Arizona (USA). These VOCs are found in concentrations much higher than predicted by partitioning alone. The reactivity of BTEX in the fog/cloud aqueous phase was investigated through laboratory studies. BTEX species showed fast degradation in the aqueous phase in the presence of peroxides and light. Observed half-lives ranged from three and six hours, substantially shorter than the respective gas phase half-lives (several days). The observed reaction rates were on the order of 1 ppb/min but decreased substantially with increasing concentrations of organic matter (TOC). The products of BTEX oxidation reactions were analyzed using HPLC-UV and LCMS. The first generation of products identified included phenol and cresols which correspond to the hydroxyl-addition reaction to benzene and toluene. Upon investigating of multi-generational products, smaller, less volatile species are predominant although a large variety of products is found. Most reaction products have substantially lower vapor pressure and will remain in the particle phase upon droplet evaporation. The SOA generation potential of cloud and fog processing of BTEX was evaluated using simple calculations and showed that in ideal situations these reactions could add up to 9% of the ambient aerosol mass. In more conservative scenarios, the contribution of the processing of BTEX was around 1% of ambient aerosol concentrations. Overall, cloud processing of VOC has the potential to contribute to the atmospheric aerosol mass. However, the contribution will depend upon many factors such as the irradiation, organic matter content in the droplets and droplet lifetime.

  19. Novel ArF photoresist polymer to suppress the roughness formation in plasma etching processes

    NASA Astrophysics Data System (ADS)

    Kato, Keisuke; Yasuda, Atsushi; Maeda, Shin-ichi; Uesugi, Takuji; Okada, Takeru; Wada, Akira; Samukawa, Seiji

    2013-03-01

    The serious problem associated with 193-nm lithography using an ArF photoresist is roughness formation of photoresist polymer during plasma processes. We have previously investigated the mechanism of roughness formation caused by plasma. The main deciding factor for roughness formation is a chemical reaction between photoresist polymer and reactive species from plasma. The lactone group in photoresist polymer is highly chemically reactive, and shrinking the lactone structure enhances the roughness formation. In this paper, on the basis of the mechanism of roughness formation, we propose a novel ArF photoresist polymer. The roughness formation was much more suppressed in the novel photoresist polymer during plasma etching process than in the previous type. In the novel photoresist polymer, chemical reactions were spread evenly on the photoresist film surface by adding the polar structure. As a result, decreases in the lactone group were inhibited, leading to suppressing ArF photoresist roughness.

  20. Scaling properties of pyramidal islands formation process at epitaxial growth

    NASA Astrophysics Data System (ADS)

    Kharchenko, Vasyl O.; Kharchenko, Dmitrii O.; Dvornichenko, Alina V.

    2015-01-01

    We study scaling properties of the surface morphology at epitaxial growth in a generalized phase-field model by taking into account dynamics of the adsorbate temperature. We have found that growth processes are defined by a set of roughness and growth exponents. It is shown that the growth rate of the averaged mean area of islands can be controlled by deposition flux, interaction strength of adsorbate and time scale for the temperature relaxation. We have shown, that both number of islands and average island size behave in a power-law form over exposing time. We have discussed two different numerical approaches allowing one to determine the distribution function of islands over sizes. Obtained distributions are universal and do not change with variation in main system parameters.

  1. Recovery and regeneration of spent MHD seed material by the formate process

    DOEpatents

    Sheth, A.C.; Holt, J.K.; Rasnake, D.G.; Solomon, R.L.; Wilson, G.L.; Herrigel, H.R.

    1991-10-15

    The specification discloses a spent seed recovery and regeneration process for an MHD power plant employing an alkali metal salt seed material such as potassium salt wherein the spent potassium seed in the form of potassium sulfate is collected from the flue gas and reacted with calcium hydroxide and carbon monoxide in an aqueous solution to cause the formation of calcium sulfate and potassium formate. The pH of the solution is adjusted to suppress formation of formic acid and to promote precipitation of any dissolved calcium salts. The solution containing potassium formate is then employed to provide the potassium salt in the form of potassium formate or, optionally, by heating the potassium formate under oxidizing conditions to convert the potassium formate to potassium carbonate. 5 figures.

  2. Recovery and regeneration of spent MHD seed material by the formate process

    DOEpatents

    Sheth, Atul C.; Holt, Jeffrey K.; Rasnake, Darryll G.; Solomon, Robert L.; Wilson, Gregory L.; Herrigel, Howard R.

    1991-01-01

    The specification discloses a spent seed recovery and regeneration process for an MHM power plant employing an alkali metal salt seed material such as potassium salt wherein the spent potassium seed in the form of potassium sulfate is collected from the flue gas and reacted with calcium hydroxide and carbon monoxide in an aqueous solution to cause the formation of calcium sulfate and potassium formate. The pH of the solution is adjusted to supress formation of formic acid and to promote precipitation of any dissolved calcium salts. The solution containing potassium formate is then employed to provide the potassium salt in the form of potassium formate or, optionally, by heating the potassium formate under oxidizing conditions to convert the potassium formate to potassium carbonate.

  3. The speculation of the formation process about dark matter

    NASA Astrophysics Data System (ADS)

    Han, Yongquan

    2015-04-01

    Rotation makes the radiation of the object convergence, the linear speed of the object decides the degree of convergence about object. The characteristics of the convergence object is: radiation intensity in the process of convergence become stronger, but the radiation radius is getting smaller and smaller, and the radiation will eventually converge in the objects inside, that is the dark matter. To validate that advice: 1, make a luminous ball. 2, The experimenter stay far from the light sphere in the empty night observer, until just can not see the ball or can just see extremely fuzzy (due to the distance, the light is weak and sparse). 3, high speed rotate (the rotation instead of rotate around), when the speed reaches a certain value, if we can see the ball become clear, that remains the light rays bend, radiation get smaller, but in the radiation range, the intensity of radiation become stronger. Verify that the material rotation speed reaching the speed of light, it becomes the inflection point of matter and dark matter, ultra light rotation becomes dark matter. Verify that if an object superluminal rotation, it is the dark matter

  4. Processes of ordered structure formation in polypeptide thin film solutions.

    SciTech Connect

    Botiz, I.; Schlaad, H.; Reiter, G.

    2010-06-17

    An experimental study is presented on the hierarchical assembly of {alpha}-helical block copolymers polystyrene-poly({gamma}-benzyl-L-glutamate) into anisotropic ordered structures. We transformed thin solid films into solutions through exposure to solvent vapor and studied the nucleation and growth of ordered three-dimensional structures in such solutions, with emphasis on the dependence of these processes on supersaturation with respect to the solubility limit. Interestingly, polymer solubility could be significantly influenced via variation of humidity in the surrounding gas phase. It is concluded that the interfacial tension between the ordered structures and the solution increased with humidity. The same effect was observed for other protic non-solvents in the surrounding gas phase and is attributed to a complexation of poly({gamma}-benzyl-L-glutamate) by protic non-solvent molecules (via hydrogen-bonding interactions). This change of polymer solubility was demonstrated to be reversible by addition or removal of small amounts of protic non-solvent in the surrounding gas phase. At a constant polymer concentration, ordered ellipsoidal structures could be dissolved by removing water or methanol present in the solution. Such structures formed once again when water or methanol was reintroduced via the vapor phase.

  5. Wavefront curvature limitations and compensation to polar format processing for synthetic aperture radar images.

    SciTech Connect

    Doerry, Armin Walter

    2006-01-01

    Limitations on focused scene size for the Polar Format Algorithm (PFA) for Synthetic Aperture Radar (SAR) image formation are derived. A post processing filtering technique for compensating the spatially variant blurring in the image is examined. Modifications to this technique to enhance its robustness are proposed.

  6. A Process of Identity Formation in Relation to Peers and Peer Groups.

    ERIC Educational Resources Information Center

    Asbridge, Donald J.

    This paper presents a flowsheet model describing the interpersonal process of adolescent identity formation in relation to peers and peer groups within a social-psychological context. The model describes a primary route, a secondary route, and a vicious circle as pathways toward identity formation in relation to peers and peer groups. In the…

  7. Comparison of different procedures to stabilize biogas formation after process failure in a thermophilic waste digestion system: Influence of aggregate formation on process stability

    SciTech Connect

    Kleyboecker, A.; Liebrich, M.; Kasina, M.; Kraume, M.; Wittmaier, M.; Wuerdemann, H.

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Mechanism of process recovery with calcium oxide. Black-Right-Pointing-Pointer Formation of insoluble calcium salts with long chain fatty acids and phosphate. Black-Right-Pointing-Pointer Adsorption of VFAs by the precipitates resulting in the formation of aggregates. Black-Right-Pointing-Pointer Acid uptake and phosphate release by the phosphate-accumulating organisms. Black-Right-Pointing-Pointer Microbial degradation of volatile fatty acids in the aggregates. - Abstract: Following a process failure in a full-scale biogas reactor, different counter measures were undertaken to stabilize the process of biogas formation, including the reduction of the organic loading rate, the addition of sodium hydroxide (NaOH), and the introduction of calcium oxide (CaO). Corresponding to the results of the process recovery in the full-scale digester, laboratory experiments showed that CaO was more capable of stabilizing the process than NaOH. While both additives were able to raise the pH to a neutral milieu (pH > 7.0), the formation of aggregates was observed particularly when CaO was used as the additive. Scanning electron microscopy investigations revealed calcium phosphate compounds in the core of the aggregates. Phosphate seemed to be released by phosphorus-accumulating organisms, when volatile fatty acids accumulated. The calcium, which was charged by the CaO addition, formed insoluble salts with long chain fatty acids, and caused the precipitation of calcium phosphate compounds. These aggregates were surrounded by a white layer of carbon rich organic matter, probably consisting of volatile fatty acids. Thus, during the process recovery with CaO, the decrease in the amount of accumulated acids in the liquid phase was likely enabled by (1) the formation of insoluble calcium salts with long chain fatty acids, (2) the adsorption of volatile fatty acids by the precipitates, (3) the acid uptake by phosphorus-accumulating organisms and (4

  8. Research on droplet formation and dripping behavior during the electroslag remelting process

    NASA Astrophysics Data System (ADS)

    Cao, Yu-long; Dong, Yan-wu; Jiang, Zhou-hua; Cao, Hai-bo; Hou, Dong; Feng, Qian-long

    2016-04-01

    A better understanding of droplet formation and dripping behavior would be useful in the efficient removal of impurity elements and nonmetallic inclusions from liquid metals. In the present work, we developed a transparent experimental apparatus to study the mechanisms of droplet formation and the effects of filling ratio on droplet behavior during the electroslag remelting (ESR) process. A high-speed camera was used to clearly observe, at small time scales, the droplet formation and dripping phenomenon at the slag/metal interface during a stable ESR process. The results illustrate that a two-stage process for droplet formation and dripping occurs during the ESR process and that the droplet diameter exhibits a parabolic distribution with increasing filling ratio because of the different shape and thermal state of the electrode tip. This work also confirms that a relatively large filling ratio reduces electricity consumption and improves ingot quality.

  9. A survey of SAR image-formation processing for earth resources applications

    NASA Technical Reports Server (NTRS)

    Bayma, R. W.; Jordan, R. L.; Manning, B. N.

    1977-01-01

    Currently there is considerable interest in active microwave sensors for earth resources applications, such as the SEASAT-A radar. However, to obtain spatial resolutions comparable to optical sensors at radar frequencies, sophisticated image formation processing techniques must be applied to the raw data. Processing requirements for non-coherent optical and coherent radar imaging systems are compared. The image formation processing requirements for synthetic aperture radar (SAR) systems are discussed. Both optical and digital techniques are addressed, and examples of hardware and imagery for each processing technique are presented.

  10. A survey of SAR image-formation processing for earth resources applications

    NASA Technical Reports Server (NTRS)

    Bayma, R. W.; Jordan, R. L.; Manning, B. N.

    1977-01-01

    Currently there is considerable interest in active microwave sensors for earth resources applications. A particular example is the Seasat-A radar. However, to obtain spatial resolutions comparable to optical sensors at radar frequencies, sophisticated image formation processing techniques must be applied to the raw data. This paper briefly compares processing requirements for non-coherent optical and coherent radar imaging systems, and then discusses the image formation processing requirements for synthetic aperture radar (SAR) systems. Both optical and digital techniques are addressed, and examples of hardware and imagery for each processing technique are presented.

  11. Formation kinetics of potential fermentation inhibitors in a steam explosion process of corn straw.

    PubMed

    Zhang, Yuzhen; Wang, Lan; Chen, Hongzhang

    2013-01-01

    The weak acids, furan derivatives, and phenolic compounds formed during lignocellulose pretreatment are potential inhibitors of subsequent enzymatic and microbial processes. In this work, the effects of the steam explosion process on the formation of weak acids, furan derivatives, and phenolic compounds were explored. The correlations of different steam explosion conditions and formation kinetics of degradation products showed that the formation of weak acids and furan derivatives was in the first-order reactions, which are expressed as [Formula: see text]. The formation of weak acids and furan derivatives increases with pretreatment temperature and time. On the other hand, the formation of phenolic compounds showed typical characteristics of continuous reaction, expressed as [Formula: see text]. The formation was affected by the active energies in two stages, temperature and time, and thus existed at extreme value. This work revealed the formation rules of weak acids, furan derivatives, and phenolic compounds in a steam explosion process and provided theoretical guidelines for improving the process and limiting the production of certain inhibitors. PMID:23188657

  12. Pre-Processing Code System for Data in ENDF/B Format.

    SciTech Connect

    CULLEN, D. E.

    2015-04-01

    Version 08 PREPRO2015-2 is a modular set of computer codes, each of which reads evaluated nuclear data in the ENDF/B format, processes the data and outputs it in the ENDF/B format. Each code performs one or more independent operations on the data. The codes are named "the pre-processing" codes, because they are designed to pre process ENDF/B data, for later, further processing for use in applications. These codes are designed to operate on virtually any type of computer with the included capability of optimization on any given computer. They can process datasets in any ENDF/B format, ENDF/B-I through ENDF/B-VII. This package containes updated content. Additional information is available on the PREPRO website: http://www-nds.iaea.org/ndspub/endf/prepro/.

  13. Pre-Processing Code System for Data in ENDF/B Format.

    Energy Science and Technology Software Center (ESTSC)

    2015-04-01

    Version 08 PREPRO2015-2 is a modular set of computer codes, each of which reads evaluated nuclear data in the ENDF/B format, processes the data and outputs it in the ENDF/B format. Each code performs one or more independent operations on the data. The codes are named "the pre-processing" codes, because they are designed to pre process ENDF/B data, for later, further processing for use in applications. These codes are designed to operate on virtually anymore » type of computer with the included capability of optimization on any given computer. They can process datasets in any ENDF/B format, ENDF/B-I through ENDF/B-VII. This package containes updated content. Additional information is available on the PREPRO website: http://www-nds.iaea.org/ndspub/endf/prepro/.« less

  14. Deciphering and Reversing Tumor Immune Suppression

    PubMed Central

    Motz, Greg T.; Coukos, George

    2013-01-01

    Generating an anti-tumor immune response is a multi-step process that is executed by effector T cells that can recognize and kill tumor targets. However, tumors employ multiple strategies to attenuate the effectiveness of T cell-mediated attack. This is achieved by interfering with nearly every step required for effective immunity, from deregulation of antigen-presenting cells, to establishment of a physical barrier at the vasculature that prevents homing of effector tumor-rejecting cells, and through the suppression of effector lymphocytes through the recruitment and activation of immunosuppressive cells like myeloid-derived suppressor cells (MDSCs), tolerogenic monocytes and T regulatory cells (Tregs). Here, we review the ways in which tumors exert immune suppression and highlight the new therapies that seek to reverse this phenomenon and promote anti-tumor immunity. Understanding anti-tumor immunity, and how it becomes disabled by tumors, will ultimately lead to improved immune therapies and prolonged survival of patients. PMID:23890064

  15. Galaxy formation in the Planck cosmology - II. Star-formation histories and post-processing magnitude reconstruction

    NASA Astrophysics Data System (ADS)

    Shamshiri, Sorour; Thomas, Peter A.; Henriques, Bruno M.; Tojeiro, Rita; Lemson, Gerard; Oliver, Seb J.; Wilkins, Stephen

    2015-08-01

    We adapt the L-GALAXIES semi-analytic model to follow the star formation histories (SFHs) of galaxies - by which we mean a record of the formation time and metallicities of the stars that are present in each galaxy at a given time. We use these to construct stellar spectra in post-processing, which offers large efficiency savings and allows user-defined spectral bands and dust models to be applied to data stored in the Millennium data repository. We contrast model SFHs from the Millennium Simulation with observed ones from the VESPA algorithm as applied to the Sloan Digital Sky Survey 7 (SDSS-7) catalogue. The overall agreement is good, with both simulated and SDSS galaxies showing a steeper SFH with increased stellar mass. The SFHs of blue and red galaxies, however, show poor agreement between data and simulations, which may indicate that the termination of star formation is too abrupt in the models. The mean star formation rate (SFR) of model galaxies is well defined and is accurately modelled by a double power law at all redshifts: SFR ∝ 1/(x-1.39 + x1.33), where x = (ta - t)/3.0 Gyr, t is the age of the stars and ta is the lookback time to the onset of galaxy formation; above a redshift of unity, this is well approximated by a gamma function: SFR ∝ x1.5e-x, where x = (ta - t)/2.0 Gyr. Individual galaxies, however, show a wide dispersion about this mean. When split by mass, the SFR peaks earlier for high-mass galaxies than for lower mass ones, and we interpret this downsizing as a mass-dependence in the evolution of the quenched fraction: the SFHs of star-forming galaxies show only a weak mass-dependence.

  16. Deciphering Asthma Biomarkers with Protein Profiling Technology

    PubMed Central

    Kuang, Zhizhou; Wilson, Jarad J.; Luo, Shuhong; Zhu, Si-Wei; Huang, Ruo-Pan

    2015-01-01

    Asthma is a chronic inflammatory disease of the airways, resulting in bronchial hyperresponsiveness with every allergen exposure. It is now clear that asthma is not a single disease, but rather a multifaceted syndrome that results from a variety of biologic mechanisms. Asthma is further problematic given that the disease consists of many variants, each with its own etiologic and pathophysiologic factors, including different cellular responses and inflammatory phenotypes. These facets make the rapid and accurate diagnosis (not to mention treatments) of asthma extremely difficult. Protein biomarkers can serve as powerful detection tools in both clinical and basic research applications. Recent endeavors from biomedical researchers have developed technical platforms, such as cytokine antibody arrays, that have been employed and used to further the global analysis of asthma biomarker studies. In this review, we discuss potential asthma biomarkers involved in the pathophysiologic process and eventual pathogenesis of asthma, how these biomarkers are being utilized, and how further testing methods might help improve the diagnosis and treatment strain that current asthma patients suffer. PMID:26346739

  17. Deciphering the role of exosomes in tuberculosis.

    PubMed

    Kruh-Garcia, Nicole A; Wolfe, Lisa M; Dobos, Karen M

    2015-01-01

    Exosomes were originally described as small vesicles released from reticulocytes during the maturation process. These 40-200 nm microvesicles were hypothesized to be a mechanism for the removal of membrane proteins in lieu of intracellular degradation by Harding et al. (1984) and Johnstone et al. (1987) [1,2]. Exosomes can be distinguished from other extracellular vesicles (ectosomes, apoptotic blebs) based on their size and the protein indicators intercalated in their membrane (also, linking their derivation from the endocytic pathway) by Simpson (2012) [3]. The exact role which exosomes play in cell-to-cell communication and immune modulation is a topic of intense study. However, the focus of most reports has been directed towards discovering aberrations in exosomal protein and RNA content linked to disease onset and progression, and also primarily related to cancer. Nonetheless, exosomes are now documented to be released from a wide variety of cell types by Mathivanan et al. (2012), Simpson et al. (2012) and Kalra et al. (2012) [4-6] and have been isolated from all bodily fluids; thus, exosomes are an excellent source of biomarkers. Here we describe the discoveries related to the role exosomes play in tuberculosis disease, as well as translational work in vaccine development and how circulation of these dynamic vesicles can be harnessed for diagnostic purposes. PMID:25496995

  18. Fast processing of digital imaging and communications in medicine (DICOM) metadata using multiseries DICOM format

    PubMed Central

    Ismail, Mahmoud; Philbin, James

    2015-01-01

    Abstract. The digital imaging and communications in medicine (DICOM) information model combines pixel data and its metadata in a single object. There are user scenarios that only need metadata manipulation, such as deidentification and study migration. Most picture archiving and communication system use a database to store and update the metadata rather than updating the raw DICOM files themselves. The multiseries DICOM (MSD) format separates metadata from pixel data and eliminates duplicate attributes. This work promotes storing DICOM studies in MSD format to reduce the metadata processing time. A set of experiments are performed that update the metadata of a set of DICOM studies for deidentification and migration. The studies are stored in both the traditional single frame DICOM (SFD) format and the MSD format. The results show that it is faster to update studies’ metadata in MSD format than in SFD format because the bulk data is separated in MSD and is not retrieved from the storage system. In addition, it is space efficient to store the deidentified studies in MSD format as it shares the same bulk data object with the original study. In summary, separation of metadata from pixel data using the MSD format provides fast metadata access and speeds up applications that process only the metadata. PMID:26158117

  19. Fast processing of digital imaging and communications in medicine (DICOM) metadata using multiseries DICOM format.

    PubMed

    Ismail, Mahmoud; Philbin, James

    2015-04-01

    The digital imaging and communications in medicine (DICOM) information model combines pixel data and its metadata in a single object. There are user scenarios that only need metadata manipulation, such as deidentification and study migration. Most picture archiving and communication system use a database to store and update the metadata rather than updating the raw DICOM files themselves. The multiseries DICOM (MSD) format separates metadata from pixel data and eliminates duplicate attributes. This work promotes storing DICOM studies in MSD format to reduce the metadata processing time. A set of experiments are performed that update the metadata of a set of DICOM studies for deidentification and migration. The studies are stored in both the traditional single frame DICOM (SFD) format and the MSD format. The results show that it is faster to update studies' metadata in MSD format than in SFD format because the bulk data is separated in MSD and is not retrieved from the storage system. In addition, it is space efficient to store the deidentified studies in MSD format as it shares the same bulk data object with the original study. In summary, separation of metadata from pixel data using the MSD format provides fast metadata access and speeds up applications that process only the metadata. PMID:26158117

  20. Other factors to consider in the formation of chloropropandiol fatty esters in oil processes.

    PubMed

    Ramli, Muhamad Roddy; Siew, Wai Lin; Ibrahim, Nuzul Amri; Kuntom, Ainie; Abd Razak, Raznim Arni

    2015-01-01

    This paper examines the processing steps of extracting palm oil from fresh fruit bunches in a way that may impact on the formation of chloropropandiol fatty esters (3-MCPD esters), particularly during refining. Diacylglycerols (DAGs) do not appear to be a critical factor when crude palm oils are extracted from various qualities of fruit bunches. Highly hydrolysed oils, in spite of the high free fatty acid (FFA) contents, did not show exceptionally high DAGs, and the oils did not display a higher formation of 3-MCPD esters upon heat treatment. However, acidity measured in terms of pH appears to have a strong impact on 3-MCPD ester formation in the crude oil when heated at high temperatures. The differences in the extraction process of crude palm oil from current commercial processes and that from a modified experimental process showed clearly the effect of acidity of the oil on the formation of 3-MCPD esters. This paper concludes that the washing or dilution step in palm oil mills removes the acidity of the vegetative materials and that a well-optimised dilution/washing step in the extraction process will play an important role in reducing formation of 3-MCPD esters in crude palm oil upon further heat processing. PMID:25798697

  1. Surface Layer Formation When Finish-Hardening Processing of the Parts by Smoothing

    NASA Astrophysics Data System (ADS)

    Belyaev, V. N.; Tatarkin, E. Ju

    2016-04-01

    Problems of surface layer formation of the parts, when hydraulic smoothing, are considered in this work. The results of theoretical and pilot studies of smoothing in case of nanocarbons and copper salts introduction into the process liquid are given. The influence dependences of the processing modes on roughness and microhardness of surface layer are defined.

  2. Integrating Individual Learning Processes and Organizational Knowledge Formation: Foundational Determinants for Organizational Performance

    ERIC Educational Resources Information Center

    Song, Ji Hoon; Chermack, Thomas J.; Kim, Hong Min

    2008-01-01

    This research examined the link between learning processes and knowledge formation through an integrated literature review from both academic and practical viewpoints. Individuals' learning processes and organizational knowledge creation were reviewed by means of theoretical and integrative analysis based on a lack of empirical research on the…

  3. Probing Distinct Fullerene Formation Processes from Carbon Precursors of Different Sizes and Structures.

    PubMed

    Han, Jong Yoon; Choi, Tae Su; Kim, Soyoung; Lee, Jong Wha; Ha, Yoonhoo; Jeong, Kwang Seob; Kim, Hyungjun; Choi, Hee Cheul; Kim, Hugh I

    2016-08-16

    Fullerenes, cage-structured carbon allotropes, have been the subject of extensive research as new materials for diverse purposes. Yet, their formation process is still not clearly understood at the molecular level. In this study, we performed laser desorption ionization-ion mobility-mass spectrometry (LDI-IM-MS) of carbon substrates possessing different molecular sizes and structures to understand the formation process of fullerene. Our observations show that the formation process is strongly dependent on the size of the precursor used, with small precursors yielding small fullerenes and large graphitic precursors generally yielding larger fullerenes. These results clearly demonstrate that fullerene formation can proceed via both bottom-up and top-down processes, with the latter being favored for large precursors and more efficient at forming fullerenes. Furthermore, we observed that specific structures of carbon precursors could additionally affect the relative abundance of C60 fullerene. Overall, this study provides an advanced understanding of the mechanistic details underlying the formation processes of fullerene. PMID:27434606

  4. Deciphering Parameter Sensitivity in the BvgAS Signal Transduction

    PubMed Central

    Mapder, Tarunendu; Talukder, Srijeeta; Chattopadhyay, Sudip; Banik, Suman K.

    2016-01-01

    To understand the switching of different phenotypic phases of Bordetella pertussis, we propose an optimized mathematical framework for signal transduction through BvgAS two-component system. The response of the network output to the sensory input has been demonstrated in steady state. An analysis in terms of local sensitivity amplification characterizes the nature of the molecular switch. The sensitivity analysis of the model parameters within the framework of various correlation coefficients helps to decipher the contribution of the modular structure in signal propagation. Once classified, the model parameters are tuned to generate the behavior of some novel strains using simulated annealing, a stochastic optimization technique. PMID:26812153

  5. Deciphering the bacterial glycocode: recent advances in bacterial glycoproteomics

    PubMed Central

    Longwell, Scott A.; Dube, Danielle H.

    2012-01-01

    Bacterial glycoproteins represent an attractive target for new antibacterial treatments, as they are frequently linked to pathogenesis and contain distinctive glycans that are absent in humans. Despite their potential therapeutic importance, many bacterial glycoproteins remain uncharacterized. This review focuses on recent advances in deciphering the bacterial glycocode, including metabolic glycan labeling to discover and characterize bacterial glycoproteins, lectin-based microarrays to monitor bacterial glycoprotein dynamics, crosslinking sugars to assess the roles of bacterial glycoproteins, and harnessing bacterial glycosylation systems for the efficient production of industrially important glycoproteins. PMID:23276734

  6. Surfactant process for promoting gas hydrate formation and application of the same

    DOEpatents

    Rogers, Rudy E.; Zhong, Yu

    2002-01-01

    This invention relates to a method of storing gas using gas hydrates comprising forming gas hydrates in the presence of a water-surfactant solution that comprises water and surfactant. The addition of minor amounts of surfactant increases the gas hydrate formation rate, increases packing density of the solid hydrate mass and simplifies the formation-storage-decomposition process of gas hydrates. The minor amounts of surfactant also enhance the potential of gas hydrates for industrial storage applications.

  7. Process for enhancing recovery of oil from oil-bearing earth formations

    SciTech Connect

    Watson, J.M.; Butler, J.R.

    1984-04-03

    A process is claimed for increasing recovery of oil from oil-bearing earth formations wherein H/sub 2/S from sour wellhead gas is oxidized to SO/sub 3/ which in turn is reacted with a petroleum hydrocarbon mixture to produce a petroleum sulfonate. The petroleum sulfonate is incorporated into an oil recovery enhancing fluid and introduced through an injection well into an oil-bearing earth formation to displace oil toward a production well.

  8. In-situ process for recovering hydrocarbons from a diatomite-type formation

    SciTech Connect

    Davis, B.W.

    1984-12-04

    An in-situ process for recovering hydrocarbons from a diatomite-type formation which comprises contacting the diatomite formation with a C/sub 4/-C/sub 10/ alcohol and thereafter displacing the hydrocarbon-alcohol mixture with an aqueous alkaline solution towards a production well. The aqueous alkaline solution can be displaced with additional solution or another suitable medium such as a connate water drive.

  9. Formation of disinfection by-products in the ultraviolet/chlorine advanced oxidation process.

    PubMed

    Wang, Ding; Bolton, James R; Andrews, Susan A; Hofmann, Ron

    2015-06-15

    Disinfection by-product (DBP) formation may be a concern when applying ultraviolet light and free chlorine (UV/chlorine) as an advanced oxidation process (AOP) for drinking water treatment, due to typically large chlorine doses (e.g. 5-10 mg L(-1) as free chlorine). A potential mitigating factor is the low chlorine contact times for this AOP treatment (e.g. seconds). Full-scale and pilot-scale test results showed minimal trihalomethane (THM) and haloacetic acid (HAA) formation during UV/chlorine treatment, while dichloroacetonitrile (DCAN) and bromochloroacetonitrile (BCAN) were produced rapidly. Adsorbable organic halide (AOX) formation was significant when applying the UV/chlorine process in water that had not been previously chlorinated, while little additional formation was observed in prechlorinated water. Chlorine photolysis led to chlorate and bromate formation, equivalent to approximately 2-17% and 0.01-0.05% of the photolyzed chlorine, respectively. No perchlorate or chlorite formation was observed. During simulated secondary disinfection of AOP-treated water, DBP formation potential for THMs, HAAs, HANs, and AOX was observed to increase approximately to the same extent as was observed for pretreatment using the more common AOP of UV combined with hydrogen peroxide (UV/H2O2). PMID:25747363

  10. Overview of formative, process, and outcome evaluation methods used in the VERB campaign.

    PubMed

    Berkowitz, Judy M; Huhman, Marian; Heitzler, Carrie D; Potter, Lance D; Nolin, Mary Jo; Banspach, Stephen W

    2008-06-01

    Evaluation was an integral part of the VERB campaign. This paper describes the array of evaluation methods used to support the development, implementation, and assessment of campaign activities. The evaluation of VERB consisted of formative, process, and outcome evaluations and involved both qualitative and quantitative methods. Formative evaluation allowed staff to test ideas for messages and to gauge their appropriateness for the intended audiences. Process evaluation allowed staff to test and monitor the fidelity of the campaign's implementation to objectives and to make changes while the campaign was under way. Outcome evaluation allowed staff to determine the campaign's effects on the target audience. Because a comprehensive approach was used, which included formative and process evaluation, the VERB team's ability to interpret the results of the outcome evaluation was enhanced. PMID:18471602

  11. Raman and terahertz spectroscopical investigation of cocrystal formation process of piracetam and 3-hydroxybenzoic acid

    NASA Astrophysics Data System (ADS)

    Du, Yong; Zhang, Huili; Xue, Jiadan; Fang, Hongxia; Zhang, Qi; Xia, Yi; Li, Yafang; Hong, Zhi

    2015-03-01

    Cocrystallization can improve physical and chemical properties of active pharmaceutical ingredient, and this feature has great potential in pharmaceutical development. In this study, the cocrystal of piracetam and 3-hydroxybenzoic acid under grinding condition has been characterized by Raman and terahertz spectroscopical techniques. The major vibrational modes of individual starting components and cocrystal are obtained and assigned. Spectral results show that the vibrational modes of the cocrystal are different from those of the corresponding parent materials. The dynamic process of such pharmaceutical cocrystal formation has also been monitored directly with Raman and THz spectra. The formation rate is pretty fast in first several 20 min grinding time, and then it becomes slow. After ∼35 min, such process has been almost completed. These results offer us the unique means and benchmark for characterizing the cocrystal conformation from molecule-level and also provide us rich information about the reaction dynamic during cocrystal formation process in pharmaceutical fields.

  12. Aerosol effect on the warm rain formation process: Satellite observations and modeling

    NASA Astrophysics Data System (ADS)

    Suzuki, Kentaroh; Stephens, Graeme L.; Lebsock, Matthew D.

    2013-01-01

    This study demonstrates how aerosols influence the liquid precipitation formation process. This demonstration is provided by the combined use of satellite observations and global high-resolution model simulations. Methodologies developed to examine the warm cloud microphysical processes are applied to both multi-sensor satellite observations and aerosol-coupled global cloud-resolving model (GCRM) results to illustrate how the warm rain formation process is modulated under different aerosol conditions. The observational analysis exhibits process-scale signatures of rain suppression due to increased aerosols, providing observational evidence of the aerosol influence on precipitation. By contrast, the corresponding statistics obtained from the model show a much faster rain formation even for polluted aerosol conditions and much weaker reduction of precipitation in response to aerosol increase. It is then shown that this reduced sensitivity points to a fundamental model bias in the warm rain formation process that in turn biases the influence of aerosol on precipitation. A method of improving the model bias is introduced in the context of a simplified single-column model (SCM) that represents the cloud-to-rain water conversion process in a manner similar to the original GCRM. Sensitivity experiments performed by modifying the model assumptions in the SCM and their comparisons to satellite statistics both suggest that the auto-conversion scheme has a critical role in determining the precipitation response to aerosol perturbations and also provide a novel way of constraining key parameters in the auto-conversion schemes of global models.

  13. Biofilm formation of Salmonella serotypes in simulated meat processing environments and its relationship to cell characteristics.

    PubMed

    Wang, Huhu; Ding, Shijie; Dong, Yang; Ye, Keping; Xu, Xinglian; Zhou, Guanghong

    2013-10-01

    Salmonella attached to meat contact surfaces encountered in meat processing facilities may serve as a source of cross-contamination. In this study, the influence of serotypes and media on biofilm formation of Salmonella was investigated in a simulated meat processing environment, and the relationships between biofilm formation and cell characteristics were also determined. All six serotypes (Salmonella enterica serotype Heidelberg, Salmonella Derby, Salmonella Agona, Salmonella Indiana, Salmonella Infantis, and Salmonella Typhimurium) can readily form biofilms on stainless steel surfaces, and the amounts of biofilms were significantly influenced by the serotypes, incubation media, and incubation time used in this study. Significant differences in cell surface hydrophobicity, autoaggregation, motility, and growth kinetic parameters were observed between individual serotypes tested. Except for growth kinetic parameters, the cell characteristics were correlated with the ability of biofilm formation incubated in tryptic soy broth, whereas no correlation with biofilm formation incubated in meat thawing-loss broth (an actual meat substrate) was found. Salmonella grown in meat thawing-loss broth showed a "cloud-shaped" morphology in the mature biofilm, whereas when grown in tryptic soy broth it had a "reticulum-shaped" appearance. Our study provides some practical information to understand the process of biofilm formation on meat processing contact surfaces. PMID:24112581

  14. [Test report on the system components for film processing by the middle-format technology].

    PubMed

    Furnell, E C; Pohlenz, O

    1985-12-01

    Industrially developed accessories for use with medium-format equipment, which have been tested in a-clinical settery, were evaluated separately. The automatic mounting system (Delcadro) with the plastic mount (Cadrix) was accepted by all of our colleagues, and was rated as an advantage, with hardly any reservations. A slight modification is needed in the design of the mounts. This equipment would be a desirable addition to our own equipment for routine work. The daylight system (camera magazine and feeder) is, in principle, certainly a step in the right direction. Handling of the magazine proved to be too complicated and it was prone to malfunctions. Simplification, especially of the loading mechanism, would be desirable. The film feeder is designed for use with conventional roll processing machines. In our opinion, a feeder will always be put to full use if the films processed in this machine are mainly or exclusively of middle format; the darkroom is not permanently staffed and/or adaptation to an existing daylight system (large formats) has already been effected and/or depending on availability, both large and medium size-formats can be processed fully automatically as quickly as possible. However, if films of various formats are processed by an assistant in a darkroom, it is possible to deal with the total quantity of films faster than with a feeder by inserting 3 or 4 medium-format films (or 2 or 3 large-format films) simultaneously. The Heliomat film viewer offers impressive reproductions of 100 mm film on a glare-free glass screen.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:4089483

  15. Envirotyping for deciphering environmental impacts on crop plants.

    PubMed

    Xu, Yunbi

    2016-04-01

    Global climate change imposes increasing impacts on our environments and crop production. To decipher environmental impacts on crop plants, the concept "envirotyping" is proposed, as a third "typing" technology, complementing with genotyping and phenotyping. Environmental factors can be collected through multiple environmental trials, geographic and soil information systems, measurement of soil and canopy properties, and evaluation of companion organisms. Envirotyping contributes to crop modeling and phenotype prediction through its functional components, including genotype-by-environment interaction (GEI), genes responsive to environmental signals, biotic and abiotic stresses, and integrative phenotyping. Envirotyping, driven by information and support systems, has a wide range of applications, including environmental characterization, GEI analysis, phenotype prediction, near-iso-environment construction, agronomic genomics, precision agriculture and breeding, and development of a four-dimensional profile of crop science involving genotype (G), phenotype (P), envirotype (E) and time (T) (developmental stage). In the future, envirotyping needs to zoom into specific experimental plots and individual plants, along with the development of high-throughput and precision envirotyping platforms, to integrate genotypic, phenotypic and envirotypic information for establishing a high-efficient precision breeding and sustainable crop production system based on deciphered environmental impacts. PMID:26932121

  16. Deciphering an Image Cipher Based on Mixed Transformed Logistic Maps

    NASA Astrophysics Data System (ADS)

    Liu, Yuansheng; Fan, Hua; Xie, Eric Yong; Cheng, Ge; Li, Chengqing

    2015-12-01

    Since John von Neumann suggested utilizing Logistic map as a random number generator in 1947, a great number of encryption schemes based on Logistic map and/or its variants have been proposed. This paper re-evaluates the security of an image cipher based on transformed logistic maps and proves that the image cipher can be deciphered efficiently under two different conditions: (1) two pairs of known plain-images and the corresponding cipher-images with computational complexity of O(218 + L); (2) two pairs of chosen plain-images and the corresponding cipher-images with computational complexity of O(L), where L is the number of pixels in the plain-image. In contrast, the required condition in the previous deciphering method is 87 pairs of chosen plain-images and the corresponding cipher-images with computational complexity of O(27 + L). In addition, three other security flaws existing in most Logistic-map-based ciphers are also reported.

  17. Bromate formation from bromide oxidation by the UV/persulfate process.

    PubMed

    Fang, Jing-Yun; Shang, Chii

    2012-08-21

    Bromate formation from bromide oxidation by the UV/persulfate process was investigated, along with changes in pH, persulfate dosages, and bromide concentrations in ultrapure water and in bromide-spiked real water. In general, the bromate formation increased with increasing persulfate dosage and bromide concentration. The bromate formation was initiated and primarily driven by sulfate radicals (SO(4)(•-)) and involved the formation of hypobromous acid/hypobromite (HOBr/OBr(-)) as an intermediate and bromate as the final product. Under the test conditions, the rate of the first step driven by SO(4)(•-) is slower than that of the second step. Direct UV photolysis of HOBr/OBr(-) to form bromate and the photolysis of bromate are insignificant. The bromate formation was similar for pH 4-7 but decreased over 90% with increasing pH from 7 to above 9. Less bromate was formed in the real water sample than in ultrapure water, which was primarily attributable to the presence of natural organic matter that reacts with bromine atoms, HOBr/OBr(-) and SO(4)(•-). The extent of bromate formation and degradation of micropollutants are nevertheless coupled processes unless intermediate bromine species are consumed by NOM in real water. PMID:22831804

  18. Magnetic Evolution of the <100> Interstitial Loop Formation Process in bcc Iron

    NASA Astrophysics Data System (ADS)

    Xu, Haixuan; Stoller, Roger; Stocks, G. Malcolm

    2013-03-01

    Interstitial loops are a signature of radiation damage in materials and are only observed in systems far from equilibrium state due to their high formation energies (approximately 4eV). Unlike other bcc metals, in which the interstitial loops are almost exclusively 1/2 <111> type, two types of loops, <100>and 1/2 <111> are identified in bcc iron. Although 1/2 <111> loops can be formed directly by atomic displacment cascades, the mechanism of <100> loop formation had remained undetermined since they were observed fifty years ago. Recently, the formation mechanism has been discovered using self-evolving atomistic kinetic Monte Carlo (SEAKMC) simulations. Here we describe the influence of magnetism in the corresponding loop formation process using the ab initio locally self-consistent multiple-scattering (LSMS) method. Significant magnetic moment changes during the loop formation process are observed and their effect on the loop stability are evaluated. In addition, the effects of <100> loop formation on the microstructural evolution and material properties will be discussed. Work supported by the Center for Defect Physics, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.

  19. XAFS studies of monodisperse Au nanoclusters formation in the etching process

    NASA Astrophysics Data System (ADS)

    Yang, Lina; Huang, Ting; Liu, Wei; Bao, Jie; Huang, Yuanyuan; Cao, Yuanjie; Yao, Tao; Sun, Zhihu; Wei, Shiqiang

    2016-05-01

    Understanding the formation mechanism of gold nanoclusters is essential to the development of their synthetic chemistry. Here, by using x-ray absorption fine-structure (XAFS) spectroscopy, UV-Vis and MS spectra, the formation process of monodisperse Au13 nanoclusters is investigated. We find that a critical step involving the formation of smaller Au8-Au11 metastable intermediate clusters induced by the HCl + HSR etching of the polydisperse Aun precursor clusters occurs firstly. Then these intermediate species undergo a size-growth to Au13 cores, followed by a slow structure rearrangement to reach the final stable structure. This work enriches the understanding of cluster formation chemistry and may guide the way towards the design and the controllable synthesis of nanoclusters.

  20. Deciphering Late-Pleistocence landscape evolution: linking proxies by combining pedo-stratigraphy and luminescence dating

    NASA Astrophysics Data System (ADS)

    Kreutzer, Sebastian; Meszner, Sascha; Faust, Dominik; Fuchs, Markus

    2014-05-01

    Interpreting former landscape evolution asks for understanding the processes that sculpt such landforms by means of deciphering complex systems. For reconstructing terrestrial Quaternary environments based on loess archives this might be considered, at least, as a three step process: (1) Identifying valuable records in appropriate morphological positions in a previously defined research area, (2) analysing the profiles by field work and laboratory methods and finally (3) linking the previously considered pseudo-isolated systems to set up a comprehensive picture. Especially the first and the last step might bring some pitfalls, as it is tempting to specify single records as pseudo-isolated, closed systems. They might be, with regard to their preservation in their specific morphological position, but in fact they are part of a complex, open system. Between 2008 and 2013, Late-Pleistocene loess archives in Saxony have been intensively investigated by field and laboratory methods. Linking pedo- and luminescence dating based chronostratigraphies, a composite profile for the entire Saxonian Loess Region has been established. With this, at least, two-fold approach we tried to avoid misinterpretations that might appear when focussing on one standard profile in an open morphological system. Our contribution focuses on this multi-proxy approach to decipher the Late-Pleistocene landscape evolution in the Saxonian Loess Region. Highlighting the challenges and advantages of combining different methods, we believe that (1) this multi-proxy approach is without alternative, (2) the combination of different profiles may simplify the more complex reality, but it may be a useful generalisation to understand and reveal the stratigraphical significance of the landscape evolution in this region.

  1. Effect of Process Variables on the Formation of Streak Defects on Anodized Aluminum Extrusions: An Overview

    NASA Astrophysics Data System (ADS)

    Zhu, Hanliang; Couper, Malcolm J.; Dahle, Arne K.

    2012-04-01

    Streak defects are often present on anodized extrusions of 6xxx series aluminum alloys, increasing the fabrication cost of these products. Moreover, streaking often only becomes visible after etching and anodizing treatments, rather than in the as-extruded condition, making it difficult to identify the original causes and influencing factors of these defects. In this paper, various process variables that influence the formation of streak defects on anodized aluminium extrusions are reviewed on the basis of a literature review, industrial practice and experimental results. The influencing factors involved in various processing steps such as billet quality, extrusion process, die design and etching process are considered. Effective measures for preventing the formation of streak defects in industrial extrusion products are discussed.

  2. Excimer laser annealing: A gold process for CZ silicon junction formation

    NASA Technical Reports Server (NTRS)

    Wong, David C.; Bottenberg, William R.; Byron, Stanley; Alexander, Paul

    1987-01-01

    A cold process using an excimer laser for junction formation in silicon has been evaluated as a way to avoid problems associated with thermal diffusion. Conventional thermal diffusion can cause bulk precipitation of SiOx and SiC or fail to completely activate the dopant, leaving a degenerate layer at the surface. Experiments were conducted to determine the feasibility of fabricating high quality p-n junctions using a pulsed excimer laser for junction formation at remelt temperature with ion-implanted surfaces. Solar-cell efficiency exceeding 16 percent was obtained using Czochralski single-crystal silicon without benefit of back surface field or surface passivation. Characterization shows that the formation of uniform, shallow junctions (approximately 0.25 micron) by excimer laser scanning preserves the minority carrier lifetime that leads to high current collection. However, the process is sensitive to initial surface conditions and handling parameters that drive the cost up.

  3. Quantifying fiber formation in meat analogs under high moisture extrusion using image processing

    NASA Astrophysics Data System (ADS)

    Ranasinghesagara, J.; Hsieh, F.; Yao, G.

    2005-11-01

    High moisture extrusion using twin-screw extruders shows great promise of producing meat analog products with vegetable proteins. The resulting products have well defined fiber formations; resemble real meat in both visual appearance and taste sensation. Developing reliable non-destructive techniques to quantify the textural properties of extrudates is important for quality control in the manufacturing process. In this study, we developed an image processing technique to automatically characterize sample fiber formation using digital imaging. The algorithm is based on statistical analysis of Hough transform. This objective method can be used as a standard method for evaluating other non-invasive methods. We have compared the fiber formation indices measured using this technique and a non-invasive fluorescence polarization method and obtained a high correlation.

  4. NMDA-R inhibition affects cellular process formation in Tilapia melanocytes; a model for pigmented adrenergic neurons in process formation and retraction.

    PubMed

    Ogundele, Olalekan Michael; Okunnuga, Adetokunbo Adedotun; Fabiyi, Temitope Deborah; Olajide, Olayemi Joseph; Akinrinade, Ibukun Dorcas; Adeniyi, Philip Adeyemi; Ojo, Abiodun Ayodele

    2014-06-01

    Parkinson's disease has long been described to be a product of dopamine and (or) melanin loss in the substanstia nigra (SN). Although most studies have focused on dopaminergic neurons, it is important to consider the role of pigment cells in the etiology of the disease and to create an in vitro live cell model for studies involving pigmented adrenergic cells of the SN in Parkinsonism. The Melanocytes share specific features with the pigmented adrenergic neurons as both cells are pigmented, contain adrenergic receptors and have cellular processes. Although the melanocyte cellular processes are relatively short and observable only when stimulated appropriately by epinephrine and other factors or molecules. This study employs the manipulation of N-Methyl-D-Aspartate Receptor (NMDA-R), a major receptor in neuronal development, in the process formation pattern of the melanocyte in order to create a suitable model to depict cellular process elongation and shortening in pigmented adrenergic cells. NMDA-R is an important glutamate receptor implicated in neurogenesis, neuronal migration, maturation and cell death, thus we investigated the role of NMDA-R potentiation by glutamate/KCN and its inhibition by ketamine in the behavior of fish scale melanocytes in vitro. This is aimed at establishing the regulatory role of NMDA-R in this cell type (melanocytes isolated form Tilapia) in a similar manner to what is observable in the mammalian neurons. In vitro live cell culture was prepared in modified Ringer's solution following which the cells were treated as follows; Control, Glutamate, Ketamine, Glutamate + Ketamine, KCN + Ketamine and KCN. The culture was maintained for 10 min and the changes were captured in 3D-Time frame at 0, 5 and 10 min for the control and 5, 7 and 10 min for each of the treatment category. Glutamate treatment caused formation of short cellular processes localized directly on the cell body while ketamine treatment (inhibition of NMDA-R) facilitated

  5. Formation of Mesostructured Nanoparticles through Self-Assembly and Aerosol Process

    SciTech Connect

    Brinker, C. Jeffrey; Fan, Hongyou; Lu, Yunfeng; Rieker, Thomas; Stump, Arron; Ward, Timothy L.

    1999-05-07

    Silica nanoparticles exhibiting hexagonal, cubic, and vesicular mesostructures have been prepared using aerosol assisted, self-assembled process. This process begins with homogennous aerosol droplets containing silica source, water, ethanol, and surfactant, in which surfactant concentration is far below the critical micelle concentration (cmc). Solvent evaporation enriches silica and surfactant inducing interfacial self-assembly confined to a spherical aerosol droplet and results in formation of completely solid, ordered spherical particles with stable hexagonal, cubic, or vesicular mesostructures.

  6. A Case Study on the Formation and Sharing Process of Science Classroom Norms

    ERIC Educational Resources Information Center

    Chang, Jina; Song, Jinwoong

    2016-01-01

    The teaching and learning of science in school are influenced by various factors, including both individual factors, such as member beliefs, and social factors, such as the power structure of the class. To understand this complex context affected by various factors in schools, we investigated the formation and sharing process of science classroom…

  7. Influence of California-style black ripe olive processing on the formation of acrylamide.

    PubMed

    Charoenprasert, Suthawan; Mitchell, Alyson

    2014-08-27

    Methods used in processing California-style black ripe olives generate acrylamide. California-style black ripe olives contain higher levels of acrylamide (409.67 ± 42.60-511.91 ± 34.08 μg kg(-1)) as compared to California-style green ripe olives (44.02 ± 3.55-105.79 ± 22.01 μg kg(-1)), Greek olives (<1.42 μg kg(-1)), and Spanish olives (not detected), indicating that the higher temperatures used to sterilize the California-style green ripe and black ripe olives are required for acrylamide formation. Preprocessing brine storage influenced the formation of acrylamide in a time-dependent manner. Acrylamide increased during the first 30 days of storage. Longer brine storage times (>30 days) result in lower acrylamide levels in the finished product. The presence of calcium ions in the preprocessing brining solution results in higher levels of acrylamide in finished products. Air oxidation during lye processing and the neutralization of olives prior to sterilization significantly increase the formation of acrylamide in the finished products. Conversely, lye-processing decreases the levels of acrylamide in the final product. These results indicate that specific steps in the California-style black ripe olive processing may be manipulated to mitigate the formation of acrylamide in finished products. PMID:25110929

  8. Level of Processing Modulates the Neural Correlates of Emotional Memory Formation

    ERIC Educational Resources Information Center

    Ritchey, Maureen; LaBar, Kevin S.; Cabeza, Roberto

    2011-01-01

    Emotion is known to influence multiple aspects of memory formation, including the initial encoding of the memory trace and its consolidation over time. However, the neural mechanisms whereby emotion impacts memory encoding remain largely unexplored. The present study used a levels-of-processing manipulation to characterize the impact of emotion on…

  9. Processes Underlying Developmental Reversals in False-Memory Formation: Comment on Brainerd, Reyna, and Ceci (2008)

    ERIC Educational Resources Information Center

    Ghetti, Simona

    2008-01-01

    C. J. Brainerd, V. F. Reyna, and S. J. Ceci (2008) reviewed compelling evidence of developmental reversals in false-memory formation (i.e., younger children exhibit lower false-memory rates than do older children and adults) and proposed that this phenomenon depends on the development of gist processing (i.e., the ability to identify and process…

  10. A Formative Evaluation of Biological Science: Patterns and Processes, Final Report.

    ERIC Educational Resources Information Center

    Mayer, William V.; And Others

    Reported is a formative evaluation of the Biological Science Curriculum Study "Biological Science: Patterns and Processes", designed for academically unsuccessful students. "Criterion referenced" tests were developed, with items selected to indicate the extent of students' learning rather than to discriminate between students. An alternate form,…

  11. Formation process of high-purity Ge-on-insulator layers by Ge-condensation technique

    NASA Astrophysics Data System (ADS)

    Nakaharai, S.; Tezuka, T.; Hirashita, N.; Toyoda, E.; Moriyama, Y.; Sugiyama, N.; Takagi, S.

    2009-01-01

    Formation process of Ge-on-insulator (GOI) layers by Ge condensation with very high purity of Ge is clarified in terms of diffusion behaviors of Si and Ge in a SiGe layer. It is shown that the diffusion behavior affects the Ge condensation process, and the purity of GOI layer can be determined by the relation between oxidation and diffusion of Si. Experimental results support a model of GOI formation that the selective oxidation of Si in SiGe continues until the formation of a GOI layer with the residual Si fraction of less than 0.01%. Based on this model, we quantitatively clarify the reason why GOI layers can reach very low residual Si fraction without oxidizing Ge by calculating the diffusion behavior of Si during the Ge condensation process. As a result, we have found that the thermal diffusion of Si is sufficiently fast so that the selective oxidation of Si can continue during the GOI formation process until the averaged residual Si fraction in the SGOI layer becomes lower than 0.03%, which is essentially consistent with the experimental results. In addition, we have found that, even if the GOI layer is thick, the Ge purity of GOI layer can approach 100% infinitely in principle by enhancing the Si diffusion in SGOI compared to the oxidation rate of SGOI.

  12. Evaluation of raster image compression in the context of large-format document processing

    NASA Astrophysics Data System (ADS)

    Sibade, Cedric; Barizien, Stephane; Akil, Mohamed; Perroton, Laurent

    2003-12-01

    We investigate the task of wide format still image manipulation and compression, within the framework of a document printing and copying data path. A typical document processing chain can benefit from the use of data compression, especially when it manages wide format color documents. In order to develop a new approach to use data compression for wide format printing systems, we expose in this article the benchmarking process of compression applied to large documents. Standard algorithms, from the imaging and document processing industry have been chosen for the compression of wide format color raster images. A database of image files has been created and classified for this purpose. The goal is to evaluate the performance in terms of data-flow reduction, along with quality losses in case of lossy compression. For the sake of a precise evaluation of performance of these compression algorithms, we include time measurements of the sole compression and decompression processes. A comparison of the memory footprint of each compression and decompression algorithms helps also to appreciate their resource consumptions.

  13. Embedded Formative Assessment and Classroom Process Quality: How Do They Interact in Promoting Science Understanding?

    ERIC Educational Resources Information Center

    Decristan, Jasmin; Klieme, Eckhard; Kunter, Mareike; Hochweber, Jan; Büttner, Gerhard; Fauth, Benjamin; Hondrich, A. Lena; Rieser, Svenja; Hertel, Silke; Hardy, Ilonca

    2015-01-01

    In this study we examine the interplay between curriculum-embedded formative assessment--a well-known teaching practice--and general features of classroom process quality (i.e., cognitive activation, supportive climate, classroom management) and their combined effect on elementary school students' understanding of the scientific concepts of…

  14. Formation Processes and Impacts of Reactive and Nonreactive Minerals in Permeable Reactive Barriers

    EPA Science Inventory

    Mineral precipitates in zero-valent iron PRBs can be classified by formation processes into three groups: 1) those that result from changes in chemical conditions (i.e., changes in pH, e.g., calcite); 2) those that are a consequence of microbial activity (i.e., sulfate reduction,...

  15. FORMATION PROCESSES AND CONSEQUENCES OF REACTIVE AND NON-REACTIVE MINERAL PRECIPITATES IN PERMEABLE REACTIVE BARRIERS

    EPA Science Inventory

    Mineral precipitates in zero-valent iron PRBs can be classified by formation processes into three groups: 1) those that result from changes in chemical conditions (i.e., change in pH, e.g., calcite); 2) those that are a consequence of microbial activity (i.e., sulfate reduction, ...

  16. Formation of low-dimensional crystalline nucleus region during insulin amyloidogenesis process

    SciTech Connect

    Amdursky, Nadav; Gazit, Ehud; Rosenman, Gil

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer We observe lag-phase crystallization process in insulin. Black-Right-Pointing-Pointer The crystallization is a result of the formation of higher order oligomers. Black-Right-Pointing-Pointer The crystallization also changes the secondary structure of the protein. Black-Right-Pointing-Pointer The spectroscopic signature can be used for amyloid inhibitors assay. -- Abstract: Insulin, as other amyloid proteins, can form amyloid fibrils at certain conditions. The self-assembled aggregation process of insulin can result in a variety of conformations, starting from small oligomers, going through various types of protofibrils, and finishing with bundles of fibrils. One of the most common consensuses among the various self-assembly processes that are suggested in the literature is the formation of an early stage nucleus conformation. Here we present an additional insight for the self-assembly process of insulin. We show that at the early lag phase of the process (prior to fibril formation) the insulin monomers self-assemble into ordered nanostructures. The most notable feature of this early self-assembly process is the formation of nanocrystalline nucleus regions with a strongly bound electron-hole confinement, which also change the secondary structure of the protein. Each step in the self-assembly process is characterized by an optical spectroscopic signature, and possesses a narrow size distribution. By following the spectroscopic signature we can measure the potency of amyloid fibrils inhibitors already at the lag phase. We further demonstrate it by the use of epigallocatechin gallate, a known inhibitor for insulin fibrils. The findings can result in a spectroscopic-based application for the analysis of amyloid fibrils inhibitors.

  17. Bromate ion formation in dark chlorination and ultraviolet/chlorination processes for bromide-containing water.

    PubMed

    Huang, Xin; Gao, Naiyun; Deng, Yang

    2008-01-01

    Bormate (BrO3(-)) is a carcinogenic chemical produced in ozonation or chlorination of bromide-containing water. Although its formation in seawater with or without sunlight has been previously investigated, the formation of bromate in dilute solutions, particularly raw water for water treatment plant, is unknown. In this article, the results of bench scale tests to measure the formation rates of bromate formation in dilute solutions, including de-ionized water and raw water from Yangtze River, were presented in dark chlorination and ultraviolet (UV)/chlorination processes. And the effects of initial pH, initial concentration of NaOCl, and UV light intensity on bromate formation in UV/chlorination of the diluted solutions were investigated. Detectable bromate was formed in dark chlorination of the two water samples with a relatively slow production rate. Under routine disinfecting conditions, the amount of formed bromate is not likely to exceed the national standards (10 microg/L). UV irradiation enhanced the decay of free chlorine, and, simultaneously, 6.6%--32% of Br was oxidized to BrO3(-). And the formation of bromate exhibited three stages: rapid stage, slow stage and plateau. Under the experimental conditions (pH = 4.41--11.07, Ccl2 = 1.23--4.50 mg/L), low pH and high chlorine concentration favored the generation of bromate. High light intensity promoted the production rate of bromate, but decreased its total generation amount due to acceleration of chlorine decomposition. PMID:18574968

  18. An evaluation of a formative assessment process used on post take ward rounds.

    PubMed

    Caldwell, G

    2013-01-01

    The purpose of clinical training is to develop doctors capable of delivering professional, personal, effective, high quality, safe clinical care with Intelligent Kindness. The processes supporting training must promote development towards excellence. In 2004 a formative assessment process for use on medical post take ward rounds was introduced based on a model of a Driving Instructor and Learner Driver. This process has been evaluated in comparison with the Case based Discussion (CbD) and mini-Cex by 140 of 369 trainees, using online surveys. Ten trainees were interviewed in depth. The majority of trainees reported that this process had helped them more in their development as doctors than the CbD or mini-CEX. Trainees were able to describe positive effects in areas such as diagnosis, prescribing and confidence in their work. In the NHS the assessments are meant to be "trainee driven", however all but one of the trainees stated that they preferred the routine provision of an assessment to having to ask for an assessment. This evaluation of a truly formative assessment process shows that the trainees benefit in their progression towards clinical excellence. Effective formative feedback can be provided on an Acute Medical Unit even within the constraints of busy post take ward rounds. Within a team of Consultants one should be allowed time to develop an extended Clinical Supervisor role. PMID:24364051

  19. The Policy Formation Process: A Conceptual Framework for Analysis. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Fuchs, E. F.

    1972-01-01

    A conceptual framework for analysis which is intended to assist both the policy analyst and the policy researcher in their empirical investigations into policy phenomena is developed. It is meant to facilitate understanding of the policy formation process by focusing attention on the basic forces shaping the main features of policy formation as a dynamic social-political-organizational process. The primary contribution of the framework lies in its capability to suggest useful ways of looking at policy formation reality. It provides the analyst and the researcher with a group of indicators which suggest where to look and what to look for when attempting to analyze and understand the mix of forces which energize, maintain, and direct the operation of strategic level policy systems. The framework also highlights interconnections, linkage, and relational patterns between and among important variables. The framework offers an integrated set of conceptual tools which facilitate understanding of and research on the complex and dynamic set of variables which interact in any major strategic level policy formation process.

  20. Evidence of reaction rate influencing cubic and hexagonal phase formation process in CdS nanocrystals

    NASA Astrophysics Data System (ADS)

    Deka, Kuldeep; Kalita, M. P. C.

    2016-05-01

    CdS nanocrystals are synthesized by co-precipitation method using 2-mercaptoethanol (ME) as capping agent. Cubic, hexagonal and their mixture are obtained by varying the ME concentration. Lower (higher) ME concentration results in cubic (hexagonal) phase. The crystallite sizes are in the range 3-7 nm. Increase in ME concentration lead to lower reaction rate between Cd2+ and S2- of the precursors, and slower reaction rate is found to favor hexagonal phase formation over the cubic one in CdS nanocrystals. Role of reaction rate in the phase formation process provides a way to synthesize CdS nanocrystals in desired crystal phase.

  1. Langevin Dynamics Deciphers the Motility Pattern of Swimming Parasites

    NASA Astrophysics Data System (ADS)

    Zaburdaev, Vasily; Uppaluri, Sravanti; Pfohl, Thomas; Engstler, Markus; Friedrich, Rudolf; Stark, Holger

    2011-05-01

    The parasite African trypanosome swims in the bloodstream of mammals and causes the highly dangerous human sleeping sickness. Cell motility is essential for the parasite’s survival within the mammalian host. We present an analysis of the random-walk pattern of a swimming trypanosome. From experimental time-autocorrelation functions for the direction of motion we identify two relaxation times that differ by an order of magnitude. They originate from the rapid deformations of the cell body and a slower rotational diffusion of the average swimming direction. Velocity fluctuations are athermal and increase for faster cells whose trajectories are also straighter. We demonstrate that such a complex dynamics is captured by two decoupled Langevin equations that decipher the complex trajectory pattern by referring it to the microscopic details of cell behavior.

  2. Essential processes for cognitive behavioral clinical supervision: Agenda setting, problem-solving, and formative feedback.

    PubMed

    Cummings, Jorden A; Ballantyne, Elena C; Scallion, Laura M

    2015-06-01

    Clinical supervision should be a proactive and considered endeavor, not a reactive one. To that end, supervisors should choose supervision processes that are driven by theory, best available research, and clinical experience. These processes should be aimed at helping trainees develop as clinicians. We highlight 3 supervision processes we believe should be used at each supervision meeting: agenda setting, encouraging trainee problem-solving, and formative feedback. Although these are primarily cognitive-behavioral skills, they can be helpful in combination with other supervision models. We provide example dialogue from supervision exchanges, and discuss theoretical and research support for these processes. Using these processes not only encourages trainee development but also models for them how to use the same processes and approaches with clients. PMID:25895121

  3. Formation of insoluble organic matter in type-1 and -2 chondrites: Radiolytic or thermal processes?

    NASA Astrophysics Data System (ADS)

    Quirico, E.; Orthous-Daunay, F.; Beck, P.; Bonal, L.; Brunetto, R.; Dartois, E.; Pino, T.; Montagnac, G.; Rouzaud, J.; Engrand, C.; Duprat, J.

    2014-07-01

    Insoluble organic matter (IOM) extracted from primitive chondrites comes in the form of a polyaromatic solid with a structure and composition resembling that of terrestrial kerogens. It bears large D/H and ^{15}N/^{14}N isotopic ratios that point to a formation in a cold environment and ion-molecule reactions. However, the nature of the chemical and physical processes that led to its formation is still actively discussed: formation in the parent body by slight thermal metamorphism [1], inheritance from interstellar medium [2], or formation in the upper layer of the protosolar disk [3]. Post-accretional evolution of organic matter has also emerged as a critical issue, as it may disturb or even obscure pre-accretional information. In type 1 and 2 chondrites, evidence of short duration thermal heating of OM has been found using a variety of techniques [4]. In order to unravel pre-accretional from post-accretional processes, we have performed a survey of the composition and structure of IOM on a series of 27 CR, CM, CI, and ungrouped C2 carbonaceous chondrites (Tagish Lake, Bells, Essebi, Acfer 094) using infrared and multi-wavelength Raman micro-spectroscopy (244-, 514-, and 785-nm laser excitations [5]). Our results show that chondritic IOM from PCA 91008 (CM2), WIS 91600 (CM2), QUE 93005 (CM2), Tagish Lake (C2 ungrouped), and possibly Cold Bokkeveld (CM2) has been subjected to the past action of short-duration thermal metamorphism, presumably triggered by impacts. The IOM in most of the CM chondrites that experienced moderate to heavy aqueous alteration may have been slightly modified by collision-induced heating. Even IOM from chondrites that escaped significant thermal metamorphism (e.g., the most primitive CR chondrites) displays Raman characteristics consistent with a formation by thermal processing. This process may have happened either in the protosolar disk or in the parent body. However, an alternative energetic process to thermal heating is ion irradiation

  4. Electrochemical oxide film formation at noble metals as a surface-chemical process

    NASA Astrophysics Data System (ADS)

    Conway, B. E.

    1995-08-01

    The mechanisms of electrochemical oxide film formation at noble metals are described and exemplified by the cases of Pt and Au, especially in the light of recent experimentation by means of cyclic voltammetry, ellipsometry and vacuum surface-science studies using LEED and AES. Unlike the mechanisms of base-metal oxidation, e.g., in corrosion processes, anodic oxide film formation at noble metals proceeds by surface chemical processes involving, initially, sub-monolayer, through monolayer, formation of 2-dimensional {OH}/{O} arrays. During such 2-d processes, place-exchange between electrosorbed OH or O species on the surface, and Pt or Au atoms within the surface lattice, takes place leading to a quasi-2-d compact film which then grows ultimately to a multilayer hydrous oxide film, probably by continuing injection of ions of the substrate metal and their migration through the growing film under the influence of the field. The initial, sub-monolayer stage of electrosorption of OH involves competitive chemisorption by anions, e.g. HSO 4-, ClO 4-, Cl -, which inhibits onset of the first stage of surface oxidation. These processes are demonstrable in experiments on single-crystal surfaces. The combination of such anion effects with place-exchange during the extension of the film, leads to a general mechanism of noble metal oxide film formation. The formation of the oxide films can be examined in detail by recording the distinguishable stages in the film's electrochemical reduction in linear-sweep voltammetry which is sensitive down to {OH}/{O} fractional coverages as low as 0.5% and over time-scales down to 50μs in experiments on time-evolution and transformation of the states of the oxide films. By means of LEED, AES and STM or AFM experiments, the reconstructions and perturbations (e.g. generation of stepped terraces) which oxide films cause on singlecrystal surfaces can be followed.

  5. Examining the role of reciprocity within the formative assessment process alongside prospective teachers

    NASA Astrophysics Data System (ADS)

    Kaftan, Juliann M.

    This self-study examines the role of reciprocity within the formative assessment process in order to explore preservice teacher understandings of the complexities of the teaching/learning/assessment process. I study myself in relation to my practice in order to provide an account of how my knowledge of teaching is lived out in practice. Through the various chapters, I give the reader glimpses of my background and the particular situations that draw out theory/practice relations. The conceptual framework gives the reader an idea of the assumptions that frame my thinking. In particular, I articulate knowledge as experiential and perception as multi-layered. Self-study methodology enables a sharing of my professional history in relation to my practice by making the interaction of theory/practice relations transparent. The chapters on formative assessment and the depth of reciprocity share my knowledge in action as seen through the course design, materials used, social interactions, temporality of the daily schedule and pivotal moments. There is a recognition of the importance played by noticing the details and being open to the unexpected during these pivotal moments. Interaction, complexity and growth are seen as pervasive qualities that permeate the reciprocity of formative assessment when it is used to promote embodied understandings. What emerges by studying the dynamics of reciprocity is the range of depth of understanding that is encountered and allowed by various students. A pedagogy of embodiment is revealed as being connected with the role of reciprocity in formative assessment. When formative assessment is used as a process to expose student thinking and foster interaction, the complexity of the teaching/learning/assessment interaction is brought to light. Students who actively attempt to give meaning to and make sense of this complexity, through the reciprocity of formative assessment, come to embody a new, lived understanding of the teaching

  6. The formation process of the He I lambda 10830 line in cool giant stars

    NASA Technical Reports Server (NTRS)

    Luttermoser, Donald G.

    1993-01-01

    The Final Report on the formation process of the He I lambda 10830 line in cool giant stars is presented. The research involves observing a sample of cool giant stars with ROSAT. These stars were selected from the list of bright stars which display He I lambda 10830 in absorption or emission and lie on the cool side of the coronal dividing line. With measured x ray fluxes or upper limits measured by the Position Sensitive Proportional Counter (PSPC), the role x rays play in the formation of this important line was investigated using the non-LTE radiative transfer code PANDORA. Hydrodynamic calculations were performed to investigate the contributions of acoustic wave heating in the formation of this line as well.

  7. α-Casein Inhibits Insulin Amyloid Formation by Preventing the Onset of Secondary Nucleation Processes.

    PubMed

    Librizzi, Fabio; Carrotta, Rita; Spigolon, Dario; Bulone, Donatella; San Biagio, Pier Luigi

    2014-09-01

    α-Casein is known to inhibit the aggregation of several proteins, including the amyloid β-peptide, by mechanisms that are not yet completely clear. We studied its effects on insulin, a system extensively used to investigate the properties of amyloids, many of which are common to all proteins and peptides. In particular, as for other proteins, insulin aggregation is affected by secondary nucleation pathways. We found that α-casein strongly delays insulin amyloid formation, even at extremely low doses, when the aggregation process is characterized by secondary nucleation. At difference, it has a vanishing inhibitory effect on the initial oligomer formation, which is observed at high concentration and does not involve any secondary nucleation pathway. These results indicate that an efficient inhibition of amyloid formation can be achieved by chaperone-like systems, by sequestering the early aggregates, before they can trigger the exponential proliferation brought about by secondary nucleation mechanisms. PMID:26278257

  8. Formation processes and main properties of hollow aluminosilicate microspheres in fly ash from thermal power stations

    SciTech Connect

    V.S. Drozhzhin; M.Ya. Shpirt; L.D. Danilin; M.D. Kuvaev; I.V. Pikulin; G.A. Potemkin; S.A. Redyushev

    2008-04-15

    The main parameters of aluminosilicate microspheres formed at thermal power stations in Russia were studied. These parameters are responsible for the prospective industrial application of these microspheres. A comparative analysis of the properties of mineral coal components, the conditions of coal combustion, and the effects of chemical and phase-mineralogical compositions of mineral impurities in coals from almost all of the main coal deposits on the formation of microspheres was performed. The effects of thermal treatment conditions on gas evolution processes in mineral particles and on the fraction of aluminosilicate microspheres in fly ash were considered. It was found that the yield of microspheres was higher in pulverized coal combustion in furnaces with liquid slag removal, all other factors being equal. The regularities of microsphere formation were analyzed, and the mechanism of microsphere formation in fly ash during the combustion of solid fuels was considered.

  9. Molecular mechanisms regulating formation, trafficking and processing of annular gap junctions.

    PubMed

    Falk, Matthias M; Bell, Cheryl L; Kells Andrews, Rachael M; Murray, Sandra A

    2016-01-01

    Internalization of gap junction plaques results in the formation of annular gap junction vesicles. The factors that regulate the coordinated internalization of the gap junction plaques to form annular gap junction vesicles, and the subsequent events involved in annular gap junction processing have only relatively recently been investigated in detail. However it is becoming clear that while annular gap junction vesicles have been demonstrated to be degraded by autophagosomal and endo-lysosomal pathways, they undergo a number of additional processing events. Here, we characterize the morphology of the annular gap junction vesicle and review the current knowledge of the processes involved in their formation, fission, fusion, and degradation. In addition, we address the possibility for connexin protein recycling back to the plasma membrane to contribute to gap junction formation and intercellular communication. Information on gap junction plaque removal from the plasma membrane and the subsequent processing of annular gap junction vesicles is critical to our understanding of cell-cell communication as it relates to events regulating development, cell homeostasis, unstable proliferation of cancer cells, wound healing, changes in the ischemic heart, and many other physiological and pathological cellular phenomena. PMID:27230503

  10. Spontaneous formation of the unlocked state of the ribosome is a multistep process

    PubMed Central

    Munro, James B.; Altman, Roger B.; Tung, Chang-Shung; Cate, Jamie H. D.; Sanbonmatsu, Kevin Y.; Blanchard, Scott C.

    2010-01-01

    The mechanism of substrate translocation through the ribosome is central to the rapid and faithful translation of mRNA into proteins. The rate-limiting step in translocation is an unlocking process that includes the formation of an “unlocked” intermediate state, which requires the convergence of large-scale conformational events within the ribosome including tRNA hybrid states formation, closure of the ribosomal L1 stalk domain, and subunit ratcheting. Here, by imaging of the pretranslocation ribosome complex from multiple structural perspectives using two- and three-color single-molecule fluorescence resonance energy transfer, we observe that tRNA hybrid states formation and L1 stalk closure, events central to the unlocking mechanism, are not tightly coupled. These findings reveal that the unlocked state is achieved through a stochastic-multistep process, where the extent of conformational coupling depends on the nature of tRNA substrates. These data suggest that cellular mechanisms affecting the coupling of conformational processes on the ribosome may regulate the process of translation elongation. PMID:20018653

  11. Elucidation of an Iterative Process of Carbon-Carbon Bond Formation of Prebiotic Significance

    NASA Astrophysics Data System (ADS)

    Loison, Aurélie; Dubant, Stéphane; Adam, Pierre; Albrecht, Pierre

    2010-12-01

    Laboratory experiments carried out under plausible prebiotic conditions (under conditions that might have occurred at primitive deep-sea hydrothermal vents) in water and involving constituents that occur in the vicinity of submarine hydrothermal vents (e.g., CO, H2S, NiS) have disclosed an iterative Ni-catalyzed pathway of C-C bond formation. This pathway leads from CO to various organic molecules that comprise, notably, thiols, alkylmono- and disulfides, carboxylic acids, and related thioesters containing up to four carbon atoms. Furthermore, similar experiments with organic compounds containing various functionalities, such as thiols, carboxylic acids, thioesters, and alcohols, gave clues to the mechanisms of this novel synthetic process in which reduced metal species, in particular Ni(0), appear to be the key catalysts. Moreover, the formation of aldehydes (and ketones) as labile intermediates via a hydroformylation-related process proved to be at the core of the chain elongation process. Since this process can potentially lead to organic compounds with any chain length, it could have played a significant role in the prebiotic formation of lipidic amphiphilic molecules such as fatty acids, potential precursors of membrane constituents.

  12. Effects of different forms of verbal processing on the formation of intrusions.

    PubMed

    Luo, Pinchao; Jiang, Yijie; Dang, Xiaojiao; Huang, Yuesheng; Chen, Xuejun; Zheng, Xifu

    2013-04-01

    This study used the trauma film paradigm to investigate different forms of posttrauma verbal processing relevant to the formation of intrusive memories. We designed 3 experiments to investigate verbal processing that could help to reduce the formation of posttraumatic intrusions. Experiments 1 and 2 looked at the effect of several forms of verbal processing, varied in emotional foci and vantage points, on the formation of posttraumatic intrusions. Experiment 3 utilized event-related potential (ERP) technology to control emotional focus and to further examine the effect of verbal processing from different vantage points. Data produced by Experiment 1 showed that the "what-focus" group had fewer intrusions than the "why-focus" group. Experiment 2 produced no significant difference between first- and third-person vantage points. Results from the last experiment showed the what-focus group was faster to judge the colors of the words in the emotional Stroop task, and the amplitude and latency of P2 for negative words were greater than neutral words in the what-focus group. Based on the results of the experiments, participants who were led to verbalize their traumatic experiences using the what-focus and the first-person vantage point ended up with fewer intrusions. PMID:23526670

  13. Dynamics of Faceted Nanoparticles Formation in a Crystalline Matrix During Ion Implantation Processing.

    PubMed

    Li, Kun-Dar

    2016-02-01

    The faceted nanoparticle synthesized by ion implantation, such as Zn, Cu or Ag nanoparticles, is one of the promising materials for the next generation of optical devices. To understand and better control the manufacturing processes of ion implantation, a theoretical model is applied to investigate the formation and evolution of faceted nanoparticles under various experimental conditions of implantation processing. In this study, the mechanisms of the anisotropic interfacial energy and kinetics with different ion distributions are taken into consideration to demonstrate the role of the crystallographic symmetry, ion energy and temperature on the faceted nanoparticles formation in a crystalline matrix. As presented in the numerical results, the morphological shape of the nanoparticles is mainly affected by the crystallographic symmetry, while the distribution of the precipitates is principally determined by the ion energy. For the condition of high-temperature implantation, a high mobility of ions causes the characteristic length of nanostructures to increase and creates a coarsening morphology of nanoparticles. It is attributed to a longer diffusion distance during the nucleation and growth processes. This model can be widely used for the predictions of the nanostructures formation with various ion implantation processes. PMID:27433726

  14. Spontaneous formation of the unlocked state of the ribosome is a multistep process.

    PubMed

    Munro, James B; Altman, Roger B; Tung, Chang-Shung; Cate, Jamie H D; Sanbonmatsu, Kevin Y; Blanchard, Scott C

    2010-01-12

    The mechanism of substrate translocation through the ribosome is central to the rapid and faithful translation of mRNA into proteins. The rate-limiting step in translocation is an unlocking process that includes the formation of an "unlocked" intermediate state, which requires the convergence of large-scale conformational events within the ribosome including tRNA hybrid states formation, closure of the ribosomal L1 stalk domain, and subunit ratcheting. Here, by imaging of the pretranslocation ribosome complex from multiple structural perspectives using two- and three-color single-molecule fluorescence resonance energy transfer, we observe that tRNA hybrid states formation and L1 stalk closure, events central to the unlocking mechanism, are not tightly coupled. These findings reveal that the unlocked state is achieved through a stochastic-multistep process, where the extent of conformational coupling depends on the nature of tRNA substrates. These data suggest that cellular mechanisms affecting the coupling of conformational processes on the ribosome may regulate the process of translation elongation. PMID:20018653

  15. Suppression of compensating native defect formation during semiconductor processing via excess carriers

    DOE PAGESBeta

    Alberi, Kirstin; Scarpulla, M. A.

    2016-06-21

    In many semiconductors, compensating defects set doping limits, decrease carrier mobility, and reduce minority carrier lifetime thus limiting their utility in devices. Native defects are often responsible. Suppressing the concentrations of compensating defects during processing close to thermal equilibrium is difficult because formation enthalpies are lowered as the Fermi level moves towards the majority band edge. Excess carriers, introduced for example by photogeneration, modify the formation enthalpy of semiconductor defects and thus can be harnessed during crystal growth or annealing to suppress defect populations. Herein we develop a rigorous and general model for defect formation in the presence of steady-statemore » excess carrier concentrations by combining the standard quasi-chemical formalism with a detailed-balance description that is applicable for any defect state in the bandgap. Considering the quasi-Fermi levels as chemical potentials, we demonstrate that increasing the minority carrier concentration increases the formation enthalpy for typical compensating centers, thus suppressing their formation. Furthermore, this effect is illustrated for the specific example of GaSb. While our treatment is generalized for excess carrier injection or generation in semiconductors by any means, we provide a set of guidelines for applying the concept in photoassisted physical vapor deposition.« less

  16. Suppression of compensating native defect formation during semiconductor processing via excess carriers

    NASA Astrophysics Data System (ADS)

    Alberi, K.; Scarpulla, M. A.

    2016-06-01

    In many semiconductors, compensating defects set doping limits, decrease carrier mobility, and reduce minority carrier lifetime thus limiting their utility in devices. Native defects are often responsible. Suppressing the concentrations of compensating defects during processing close to thermal equilibrium is difficult because formation enthalpies are lowered as the Fermi level moves towards the majority band edge. Excess carriers, introduced for example by photogeneration, modify the formation enthalpy of semiconductor defects and thus can be harnessed during crystal growth or annealing to suppress defect populations. Herein we develop a rigorous and general model for defect formation in the presence of steady-state excess carrier concentrations by combining the standard quasi-chemical formalism with a detailed-balance description that is applicable for any defect state in the bandgap. Considering the quasi-Fermi levels as chemical potentials, we demonstrate that increasing the minority carrier concentration increases the formation enthalpy for typical compensating centers, thus suppressing their formation. This effect is illustrated for the specific example of GaSb. While our treatment is generalized for excess carrier injection or generation in semiconductors by any means, we provide a set of guidelines for applying the concept in photoassisted physical vapor deposition.

  17. Suppression of compensating native defect formation during semiconductor processing via excess carriers

    PubMed Central

    Alberi, K.; Scarpulla, M. A.

    2016-01-01

    In many semiconductors, compensating defects set doping limits, decrease carrier mobility, and reduce minority carrier lifetime thus limiting their utility in devices. Native defects are often responsible. Suppressing the concentrations of compensating defects during processing close to thermal equilibrium is difficult because formation enthalpies are lowered as the Fermi level moves towards the majority band edge. Excess carriers, introduced for example by photogeneration, modify the formation enthalpy of semiconductor defects and thus can be harnessed during crystal growth or annealing to suppress defect populations. Herein we develop a rigorous and general model for defect formation in the presence of steady-state excess carrier concentrations by combining the standard quasi-chemical formalism with a detailed-balance description that is applicable for any defect state in the bandgap. Considering the quasi-Fermi levels as chemical potentials, we demonstrate that increasing the minority carrier concentration increases the formation enthalpy for typical compensating centers, thus suppressing their formation. This effect is illustrated for the specific example of GaSb. While our treatment is generalized for excess carrier injection or generation in semiconductors by any means, we provide a set of guidelines for applying the concept in photoassisted physical vapor deposition. PMID:27323863

  18. Suppression of compensating native defect formation during semiconductor processing via excess carriers.

    PubMed

    Alberi, K; Scarpulla, M A

    2016-01-01

    In many semiconductors, compensating defects set doping limits, decrease carrier mobility, and reduce minority carrier lifetime thus limiting their utility in devices. Native defects are often responsible. Suppressing the concentrations of compensating defects during processing close to thermal equilibrium is difficult because formation enthalpies are lowered as the Fermi level moves towards the majority band edge. Excess carriers, introduced for example by photogeneration, modify the formation enthalpy of semiconductor defects and thus can be harnessed during crystal growth or annealing to suppress defect populations. Herein we develop a rigorous and general model for defect formation in the presence of steady-state excess carrier concentrations by combining the standard quasi-chemical formalism with a detailed-balance description that is applicable for any defect state in the bandgap. Considering the quasi-Fermi levels as chemical potentials, we demonstrate that increasing the minority carrier concentration increases the formation enthalpy for typical compensating centers, thus suppressing their formation. This effect is illustrated for the specific example of GaSb. While our treatment is generalized for excess carrier injection or generation in semiconductors by any means, we provide a set of guidelines for applying the concept in photoassisted physical vapor deposition. PMID:27323863

  19. FTOOLS - A New Package of Programs to Manipulate and Process FITS Format Files

    NASA Astrophysics Data System (ADS)

    Pence, W. D.

    1992-05-01

    The High Energy Astrophysics Science Archive Research Center (HEASARC) is developing a comprehensive set of programs to manipulate and analyze files in FITS (Flexible Image Transport System) format. One consequence of this project is to greatly expand the usage of FITS from simply a transport or interchange format to a convenient and versatile format to be used directly for data reduction and analysis. The FTOOLS utilities are specifically being written to process the data from the Astro-D X-Ray satellite, but the tools themselves are very general and can be used to analyze any FITS format file. These utilities are built on top of the FITSIO subroutine library and are written in ANSI standard Fortran or C. The software is easily portable to different processing environments and will be available as an IRAF package as well as a set of stand-alone set of executable tasks on VMS or Unix systems. The current status of the FTOOLS project will be described along with plans for future enhancements.

  20. The indication of Martian gully formation processes by slope-area analysis

    USGS Publications Warehouse

    Conway, S.J.; Balme, M.R.; Murray, J.B.; Towner, M.C.; Okubo, C.H.; Grindrod, P.M.

    2011-01-01

    The formation process of recent gullies on Mars is currently under debate. This study aims to discriminate between the proposed formation processes - pure water flow, debris flow and dry mass wasting - through the application of geomorphological indices commonly used in terrestrial geomorphology. High-resolution digital elevation models (DEMs) of Earth and Mars were used to evaluate the drainage characteristics of small slope sections. Data from Earth were used to validate the hillslope, debris-flow and alluvial process domains previously found for large fluvial catchments on Earth, and these domains were applied to gullied and ungullied slopes on Mars. In accordance with other studies, our results indicate that debris flow is one of the main processes forming the Martian gullies that were being examined. The source of the water is predominantly distributed surface melting, not an underground aquifer. Evidence is also presented indicating that other processes may have shaped Martian crater slopes, such as ice-assisted creep and solifluction, in agreement with the proposed recent Martian glacial and periglacial climate. Our results suggest that, within impact craters, different processes are acting on differently oriented slopes, but further work is needed to investigate the potential link between these observations and changes in Martian climate. ?? The Geological Society of London 2011.

  1. Formation of Volatile Tea Constituent Indole During the Oolong Tea Manufacturing Process.

    PubMed

    Zeng, Lanting; Zhou, Ying; Gui, Jiadong; Fu, Xiumin; Mei, Xin; Zhen, Yunpeng; Ye, Tingxiang; Du, Bing; Dong, Fang; Watanabe, Naoharu; Yang, Ziyin

    2016-06-22

    Indole is a characteristic volatile constituent in oolong tea. Our previous study indicated that indole was mostly accumulated at the turn over stage of oolong tea manufacturing process. However, formation of indole in tea leaves remains unknown. In this study, one tryptophan synthase α-subunit (TSA) and three tryptophan synthase β-subunits (TSBs) from tea leaves were isolated, cloned, sequenced, and functionally characterized. Combination of CsTSA and CsTSB2 recombinant protein produced in Escherichia coli exhibited the ability of transformation from indole-3-glycerol phosphate to indole. CsTSB2 was highly expressed during the turn over process of oolong tea. Continuous mechanical damage, simulating the turn over process, significantly enhanced the expression level of CsTSB2 and amount of indole. These suggested that accumulation of indole in oolong tea was due to the activation of CsTSB2 by continuous wounding stress from the turn over process. Black teas contain much less indole, although wounding stress is also involved in the manufacturing process. Stable isotope labeling indicated that tea leaf cell disruption from the rolling process of black tea did not lead to the conversion of indole, but terminated the synthesis of indole. Our study provided evidence concerning formation of indole in tea leaves for the first time. PMID:27263428

  2. Processes of Formation of Spheroidal Concretions and Inferences for "Blueberries" in Meridiani Planum Sediments

    NASA Technical Reports Server (NTRS)

    Coleman, Max

    2005-01-01

    The MER Opportunity Athena Science team has described spheroidal hematite nodules in sediments at Meridiani Planum on Mars [1]. They were informally referred to as "Blueberries" in the initial press releases and for brevity that is the name to be used in this abstract. Not all spheroidal objects in sediments are nodular concretions, but this paper will discuss the diagenetic processes possibly relevant to understanding the origin of the Blueberries. There are many occurrences of spheroidal diagenetic concretions in terrestrial sediments and detailed work has been done to understand the processes of their formation. In particular, it is possible to reconstruct the controls on their shapes and compositions, both mineral and chemical. Although there may not be good analogs for the Meridiani Planum hematite spherules on Earth, it may be possible to deduce the former environmental conditions that led to their formation and whether they might retain (or even be) biosignatures.

  3. Robust carrier formation process in low-band gap organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Yonezawa, Kouhei; Kamioka, Hayato; Yasuda, Takeshi; Han, Liyuan; Moritomo, Yutaka

    2013-10-01

    By means of femto-second time-resolved spectroscopy, we investigated the carrier formation process against film morphology and temperature (T) in highly-efficient organic photovoltaic, poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b '] dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b] thiophenediyl

  4. Verbalization and imagery in the process of formation of operator labor skills

    NASA Technical Reports Server (NTRS)

    Mistyuk, V. V.

    1975-01-01

    Sensorimotor control tests show that mastering operational skills occurs under conditions that stimulate the operator to independent active analysis and summarization of current information with the goal of clarifying the signs and the integral images that are a model of the situation. Goal directed determination of such an image requires inner and external speech, activates and improves the thinking of the operator, accelerates the training process, increases its effectiveness, and enables the formation of strategies in anticipating the course of events.

  5. Studies into the formation of PBDEs and PBDD/Fs in the iron ore sintering process.

    PubMed

    Drage, D S; Aries, E; Harrad, S

    2014-07-01

    Polybrominated diphenyl ethers (PBDEs) and polybrominated dibenzo-p-dioxins and furans (PBDD/Fs) were detected in stack emissions from UK sinter plants. The sum of 36 PBDE congeners was measured at a mean concentration of 295 ng/N m(3) with a standard deviation of 96 ng/N m(3). The mean PBDD/F concentrations were 0.14 ng WHO-TEQ/m(3) (range=0.03-0.39). PBDD/F emission concentrations were approximately ten times lower than their PCDD/F homologues. To understand the possible formation mechanisms of brominated organic species in iron ore sintering, both full-scale and laboratory experiments using an experimental sintering process were carried out. A complete PBDE mass balance was undertaken for a full scale sinter plant showing that PBDEs were already present in the raw materials such as iron ores and coke breeze and that a significant proportion of the PBDE inputs were actually destroyed during the process. A number of controlled experiments were conducted using a laboratory-scale sintering apparatus (sinter pot). These were designed to investigate: (a) mass balance of PBDEs during sintering, (b) the relationship between the availability of bromide (as KBr) and PBDE emissions, and (c) the influence of the availability of both bromide and PBDEs on PBDD/F formation. As observed in the full scale plant, the PBDEs already present in the raw materials were mostly destroyed during the process (79-96%) for all sinter pot experiments. Increasing amounts of KBr in the raw sinter mix did not result in a significant increase in PBDE formation suggesting that there was no PBDE formation in sintering via de novo synthesis. No relationship was observed between PBDE inputs and PBDD/F emissions indicating that PBDEs did not act as precursors for PBDD/Fs formation. Finally, PBDD/F formation was enhanced substantially with increasing amounts of KBr suggesting that their formation mechanism was similar to that of PCDD/Fs via de novo synthesis. PMID:24742560

  6. Formation, molecular structure, and morphology of humins in biomass conversion: influence of feedstock and processing conditions.

    PubMed

    van Zandvoort, Ilona; Wang, Yuehu; Rasrendra, Carolus B; van Eck, Ernst R H; Bruijnincx, Pieter C A; Heeres, Hero J; Weckhuysen, Bert M

    2013-09-01

    Neither the routes through which humin byproducts are formed, nor their molecular structure have yet been unequivocally established. A better understanding of the formation and physicochemical properties of humins, however, would aid in making biomass conversion processes more efficient. Here, an extensive multiple-technique-based study of the formation, molecular structure, and morphology of humins is presented as a function of sugar feed, the presence of additives (e.g., 1,2,4-trihydroxybenzene), and the applied processing conditions. Elemental analyses indicate that humins are formed through a dehydration pathway, with humin formation and levulinic acid yields strongly depending on the processing parameters. The addition of implied intermediates to the feedstocks showed that furan and phenol compounds formed during the acid-catalyzed dehydration of sugars are indeed included in the humin structure. IR spectra, sheared sum projections of solid-state 2DPASS (13) C NMR spectra, and pyrolysis GC-MS data indicate that humins consist of a furan-rich polymer network containing different oxygen functional groups. The structure is furthermore found to strongly depend on the type of feedstock. A model for the molecular structure of humins is proposed based on the data presented. PMID:23836679

  7. Self-consistent modeling of jet formation process in the nanosecond laser pulse regime

    SciTech Connect

    Mezel, C.; Hallo, L.; Breil, J.; Souquet, A.; Guillemot, F.; Hebert, D.

    2009-12-15

    Laser induced forward transfer (LIFT) is a direct printing technique. Because of its high application potential, interest continues to increase. LIFT is routinely used in printing, spray generation and thermal-spike sputtering. Biological material such as cells and proteins have already been transferred successfully for the creation of biological microarrays. Recently, modeling has been used to explain parts of the ejection transfer process. No global modeling strategy is currently available. In this paper, a hydrodynamic code is utilized to model the jet formation process and estimate the constraints obeyed by the bioelements during the transfer. A self-consistent model that includes laser energy absorption, plasma formation via ablation, and hydrodynamic processes is proposed and confirmed with experimental results. Fundamental physical mechanisms via one-dimensional modeling are presented. Two-dimensional (2D) simplified solutions of the jet formation model equations are proposed. Predicted results of the model are jet existence and its velocity. The 2D simulation results are in good agreement with a simple model presented by a previous investigator.

  8. Design and process aspects of laboratory scale SCF particle formation systems.

    PubMed

    Vemavarapu, Chandra; Mollan, Matthew J; Lodaya, Mayur; Needham, Thomas E

    2005-03-23

    Consistent production of solid drug materials of desired particle and crystallographic morphologies under cGMP conditions is a frequent challenge to pharmaceutical researchers. Supercritical fluid (SCF) technology gained significant attention in pharmaceutical research by not only showing a promise in this regard but also accommodating the principles of green chemistry. Given that this technology attained commercialization in coffee decaffeination and in the extraction of hops and other essential oils, a majority of the off-the-shelf SCF instrumentation is designed for extraction purposes. Only a selective few vendors appear to be in the early stages of manufacturing equipment designed for particle formation. The scarcity of information on the design and process engineering of laboratory scale equipment is recognized as a significant shortcoming to the technological progress. The purpose of this article is therefore to provide the information and resources necessary for startup research involving particle formation using supercritical fluids. The various stages of particle formation by supercritical fluid processing can be broadly classified into delivery, reaction, pre-expansion, expansion and collection. The importance of each of these processes in tailoring the particle morphology is discussed in this article along with presenting various alternatives to perform these operations. PMID:15725549

  9. Apparatus and process to enhance the uniform formation of hollow glass microspheres

    DOEpatents

    Schumacher, Ray F

    2013-10-01

    A process and apparatus is provided for enhancing the formation of a uniform population of hollow glass microspheres. A burner head is used which directs incoming glass particles away from the cooler perimeter of the flame cone of the gas burner and distributes the glass particles in a uniform manner throughout the more evenly heated portions of the flame zone. As a result, as the glass particles are softened and expand by a released nucleating gas so as to form a hollow glass microsphere, the resulting hollow glass microspheres have a more uniform size and property distribution as a result of experiencing a more homogenous heat treatment process.

  10. Laboratory and Cloud Chamber Studies of Formation Processes and Properties of Atmospheric Ice Particles

    NASA Astrophysics Data System (ADS)

    Leisner, T.; Abdelmonem, A.; Benz, S.; Brinkmann, M.; Möhler, O.; Rzesanke, D.; Saathoff, H.; Schnaiter, M.; Wagner, R.

    2009-04-01

    The formation of ice in tropospheric clouds controls the evolution of precipitation and thereby influences climate and weather via a complex network of dynamical and microphysical processes. At higher altitudes, ice particles in cirrus clouds or contrails modify the radiative energy budget by direct interaction with the shortwave and longwave radiation. In order to improve the parameterisation of the complex microphysical and dynamical processes leading to and controlling the evolution of tropospheric ice, laboratory experiments are performed at the IMK Karlsruhe both on a single particle level and in the aerosol and cloud chamber AIDA. Single particle experiments in electrodynamic levitation lend themselves to the study of the interaction between cloud droplets and aerosol particles under extremely well characterized and static conditions in order to obtain microphysical parameters as freezing nucleation rates for homogeneous and heterogeneous ice formation. They also allow the observation of the freezing dynamics and of secondary ice formation and multiplication processes under controlled conditions and with very high spatial and temporal resolution. The inherent droplet charge in these experiments can be varied over a wide range in order to assess the influence of the electrical state of the cloud on its microphysics. In the AIDA chamber on the other hand, these processes are observable under the realistic dynamic conditions of an expanding and cooling cloud- parcel with interacting particles and are probed simultaneously by a comprehensive set of analytical instruments. By this means, microphysical processes can be studied in their complex interplay with dynamical processes as for example coagulation or particle evaporation and growth via the Bergeron - Findeisen process. Shortwave scattering and longwave absorption properties of the nucleating and growing ice crystals are probed by in situ polarised laser light scattering measurements and infrared extinction

  11. Instantaneous Formation of Block Copolymer Patterns via Solvo-Thermal Casting Process

    NASA Astrophysics Data System (ADS)

    Jung, Hyun Jung; Woo, Sanghoon; Huh, June; Bang, Joona

    2015-03-01

    A self-assembly of block copolymers (BCPs) exhibits one of the most promising alternative methods for the next-generation lithography. Many semiconductor companies have explored the possibility of implementing this process in actual chip process, whereas the critical challenges such as feature size control, defect density, and long processing time need to be overcome. Regarding the BCP process, the formation of BCP patterns usually requires long processing time via thermal or solvent annealing. Herein we developed a simple processing method to promote a microphase separation of BCPs using solvo-thermal spin casting process. Spin casting has a very similar mechanism to solvent vapor annealing but its short process time prevents BCP chains from reaching equilibrium morphology. To maximize the chain mobility, we employed a high boiling point solvent and also applied the heat during spin casting. As a result, a well ordered BCP patterns were obtained within less than 5 min via solvo-thermal casting process without further additional annealing step.

  12. The becoming: students' reflections on the process of professional identity formation in medical education.

    PubMed

    Sharpless, Joanna; Baldwin, Nell; Cook, Robert; Kofman, Aaron; Morley-Fletcher, Alessio; Slotkin, Rebecca; Wald, Hedy S

    2015-06-01

    Professional identity formation (PIF) within medical education is the multifaceted, individualized process through which students develop new ways of being in becoming physicians. Personal backgrounds, values, expectations, interests, goals, relationships, and role models can all influence PIF and may account for diversity of both experience and the active constructive process of professional formation. Guided reflection, including reflective writing, has been used to enhance awareness and meaning making within the PIF process for both students and medical educators and to shed light on what aspects of medical education are most constructive for healthy PIF. Student voices about the PIF process now emerging in the literature are often considered and interpreted by medical educators within qualitative studies or in broad theoretical overviews of PIF.In this Commentary, the authors present a chorus of individual student voices from along the medical education trajectory. Medical students (years 1-4) and a first-year resident in pediatrics respond to a variety of questions based on prevalent PIF themes extracted from the literature to reflect on their personal experiences of PIF. Topics queried included pretending in medical education, role of relationships, impact of formal and informal curricula on PIF (valuable aspects as well as suggestions for change), and navigating and developing interprofessional relationships and identities. This work aims to vividly illustrate the diverse and personal forces at play in individual students' PIF processes and to encourage future pedagogic efforts supporting healthy, integrated PIF in medical education. PMID:25881650

  13. Effect of process conditions on the microstructural formation of dc reactively sputter deposited AlN

    SciTech Connect

    Ekpe, Samuel D.; Jimenez, Francisco J.; Dew, Steven K.

    2010-09-15

    Thin film aluminum nitride (AlN), because of its attractive properties, is a material with many applications. Its microstructure and hence properties are greatly influenced by the deposition process conditions. In this work, AlN was reactively deposited in a dc magnetron sputtering system at different proportions of nitrogen in the process gas mixture and at different process conditions. The microstructure and composition of the films were analyzed using x-ray diffraction data, energy dispersive spectroscopy, and scanning electron microscopy. Results show that for a process gas pressure of 0.67 Pa, a magnetron power of 100 W, and a substrate-target distance of 10 cm, a near stoichiometeric AlN can be prepared at nitrogen proportions as low as 20%. At these process conditions, (002) was the preferred crystal orientation. Dense fibrous structures were obtained, especially at low deposition rates with high proportions of nitrogen. Increase in magnetron power and decrease in distance result in a more porous structure. High kinetic energies (average) of the sputtered Al particles and high deposition rates tend to favor AlN(101) formation, while low kinetic energies of the Al particles and low deposition rates generally favor more of the AlN(100) formation.

  14. CARMA Data Storage, Archiving, Pipeline Processing, and the Quest for a Data Format

    NASA Astrophysics Data System (ADS)

    Plante, R.; Pound, M. W.; Mehringer, D.; Scott, S. L.; Beard, A.; Daniel, P.; Hobbs, R.; Kraybill, J. C.; Wright, M.; Leitch, E.; Amarnath, N. S.; Rauch, K. P.; Teuben, P. J.

    In 2005, the BIMA and OVRO mm-wave interferometers will be merged into a new array, the Combined Array for Research in Millimeter-wave Astronomy (CARMA). Each existing array has its own visibility data format, storage facility, and tradition of data analysis software. The choice for CARMA was to use one of a number of existing formats or devise a format that combined the best of each. Furthermore, it had to address three important considerations. First, the CARMA data format must satisfy the sometimes orthogonal needs of both astronomers and engineers. Second, forcing all users to adopt a single off-line reduction package is not practical; thus, multiple end-user formats are necessary. Finally, CARMA is on a strict schedule to first light; thus, any solution must meet the restrictions of an accelerated software development cycle and take advantage of code reuse as much as possible. We describe our solution in which the pipelined data passes through two forms: a low-level database-based format oriented toward engineers and a high-level dataset-based form oriented toward scientists. The BIMA Data Archive at NCSA has been operating in production mode for a decade and will be reused for CARMA with enhanced search capabilities. The integrated BIMA Image Pipeline developed at NCSA will be used to produced calibrated visibility data and images for end-users. We describe the data flow from the CARMA telescope correlator to delivery to astronomers over the web and show current examples of pipeline-processed images of BIMA observations.

  15. Formation of metal and dielectric liners using a solution process for deep trench capacitors.

    PubMed

    Ham, Yong-Hyun; Kim, Dong-Pyo; Baek, Kyu-Ha; Park, Kun-Sik; Kim, Moonkeun; Kwon, Kwang-Ho; Shin, Hong-Sik; Lee, Kijun; Do, Lee-Mi

    2012-07-01

    We demonstrated the feasibility of metal and dielectric liners using a solution process for deep trench capacitor application. The deep Si trench via with size of 10.3 microm and depth of 71 microm were fabricated by Bosch process in deep reactive ion etch (DRIE) system. The aspect ratio was about 7. Then, nano-Ag ink and poly(4-vinylphenol) (PVPh) were used to form metal and dielectric liners, respectively. The thicknesses of the Ag and PVPh liners were about 144 and 830 nm, respectively. When the curing temperature of Ag film increased from 120 to 150 degrees C, the sheet resistance decreased rapidly from 2.47 to 0.72 Omega/sq and then slightly decreased to 0.6 Omega/sq with further increasing the curing temperature beyond 150 degrees C. The proposed liner formation method using solution process is a simple and cost effective process for the high capacity of deep trench capacitor. PMID:22966677

  16. Cloud processing of organic compounds: Secondary organic aerosol and nitrosamine formation

    NASA Astrophysics Data System (ADS)

    Hutchings, James W., III

    Cloud processing of atmospheric organic compounds has been investigated through field studies, laboratory experiments, and numerical modeling. Observational cloud chemistry studies were performed in northern Arizona and fog studies in central Pennsylvania. At both locations, the cloud and fogs showed low acidity due to neutralization by soil dust components (Arizona) and ammonia (Pennsylvania). The field observations showed substantial concentrations (20-5500 ng•L -1) of volatile organic compounds (VOC) in the cloud droplets. The potential generation of secondary organic aerosol mass through the processing of these anthropogenic VOCs was investigated through laboratory and modeling studies. Under simulated atmospheric conditions, in idealized solutions, benzene, toluene, ethylbenzene, and xylene (BTEX) degraded quickly in the aqueous phase with half lives of approximately three hours. The degradation process yielded less volatile products which would contribute to new aerosol mass upon cloud evaporation. However, when realistic cloud solutions containing natural organic matter were used in the experiments, the reaction kinetics decreased with increasing organic carbon content, resulting in half lives of approximately 7 hours. The secondary organic aerosol (SUA) mass formation potential of cloud processing of BTEX was evaluated. SOA mass formation by cloud processing of BTEX, while strongly dependent on the atmospheric conditions, could contribute up to 9% of the ambient atmospheric aerosol mass, although typically ˜1% appears realistic. Field observations also showed the occurrence of N-nitrosodimethylamine (NDMA), a potent carcinogen, in fogs and clouds (100-340 ng•L -1). Laboratory studies were conducted to investigate the formation of NDMA from nitrous acid and dimethylamine in the homogeneous aqueous phase within cloud droplets. While NDMA was produced in the cloud droplets, the low yields (<1%) observed could not explain observational concentrations

  17. Tectonic and Aqueous Processes in the Formation of Mass-wasting Features on Mars and Earth

    NASA Astrophysics Data System (ADS)

    Watkins, Jessica

    2015-10-01

    Fundamental to the advancement of planetary geology is an understanding of the interaction between tectonic and aqueous processes on planetary surfaces. This dissertation examines this interaction within two geomorphologic processes: landslide emplacement, on Mars and on Earth, and the formation of seasonal slope features on Mars. Long-runout landsliding in equatorial Valles Marineris, Mars is among the most prominent geomorphic occurrences shaping the canyon. However, the mechanism of landslide long-distance transport, and the highly debated role of water therein, remains elusive. Through systematic mapping of high-resolution satellite images, integrated with spectral analysis, we show that hydrated silicates played a decisive role in facilitating landslide transport by lubricating the basal sliding zone. This conclusion implies that clay minerals, generated by ancient water-rock interactions, exert a long-lasting influence on Mars surface processes. The Eureka Valley (EV) landslide is an unexamined, well-preserved long-runout landslide in arid southeast Eureka Valley, California. The field, photogeologic, spectral, and luminescence dating investigation presented here support initiation as a result of fault-generated fracture during the mid to early Holocene at minimum, and transport lubricated by the presence of basal clays, characterized by 3-D internal deformation, as the most likely EV landslide emplacement mechanism. This geomorphological characterization may be applied to long-runout landslides on Earth and other planetary surfaces, suggesting that their emplacement likely does not require the participation of water. Recurring slope lineae (RSL) are seasonal, narrow, low-albedo features extending down steep, equator-facing Mars slopes. RSL formation has been largely attributed to the seepage of near-surface water, though its source is not well understood. Through detailed analysis of high-resolution satellite images of RSL geologic contexts, we quantify the

  18. A Multiwavelength Study of the Process of High-Mass Star Formation

    NASA Astrophysics Data System (ADS)

    Howard, Eric M.

    1996-06-01

    Massive stars live short, violent lives that have a major impact on nearby star formation and the interstellar medium (ISM). To study the process of high-mass star formation and its effect on the surrounding ISM, we have observed four regions that include 10 HII regions representing ultracompact, compact, and nearly classical HII regions: Monoceros R2; K3-50; S255-2; and NS 14. Exciting stars of the 10 HII regions span a range of masses (B1 to O4 type stars). We have placed the objects in an evolutionary sequence with K3-50A, C1, and C2 representing the earliest, ultracompact HII region stage, S255-2 and NS 14 representing an intermediate compact stage, while MonR2, K3-50B and K3-50D are more evolved, representing a nearly classical HII region stage. The process of high-mass star formation does not have a well developed theoretical basis, in part, because many complete observational studies of such regions have not been made. Toward this end, we have obtained extensive infrared images of each region mentioned above with near-infrared (NIR) broadband filters and narrow band (1-2% spectral resolution) circular variable filters (CVFs). These are complemented by radio wavelength continuum and millimeter wavelength molecular aperture synthesis observations. Massive stars spend >= 10% of their lives embedded in molecular clouds and are generally enshrouded in gas and dust when they reach the main-sequence. To account for this, we have mapped dust extinction on small spatial scales and compared these maps with dense molecular gas structures. These comparisons yield mass and molecular abundance estimates. Massive toroidal clouds are found in each region and may be ubiquitous features. Such toroidal clouds may provide the collimation necessary to form jets from strong stellar winds. Bipolar ionized outflows or jets appear well correlated with evolutionary stage, with the youngest objects producing the strongest jets. The jets appear to entrain molecular material, thereby

  19. The influence of VAR processes and parameters on white spot formation in Alloy 718

    SciTech Connect

    Damkroger, B.K.; Kelley, J.B.; Schlienger, M.E.; Van Den Avyle, J.A.; Williamson, R.L.; Zanner, F.J.

    1994-05-01

    Significant progress has occurred lately regarding the classification, characterization, and formation of white spots during vacuum arc remelting (VAR). White spots have been generally split into three categories: discrete white spots, which are believed to be associated with undissolved material which has fallen in from the shelf, crown, or torus regions; dendritic white spots, usually associated with dendrite clusters having fallen from the electrode; and solidification white spots, believed to be caused by local perturbations in the solidifications conditions. Characteristics and proposed formation mechanisms of white spots are reviewed and discussed in context of physical processes occurring during VAR, such as fluid flow and arc behavior. Where possible, their formation mechanisms will be considered with respect to specific operating parameters. In order to more fully understand the formation of solidification white spots, an experimental program has been begun to characterize the solidification stability of Alloy 718 and variants with respect to changes in growth rate and thermal environment. A description of the experimental program and preliminary results are included.

  20. [Formation of Halogenated By-products in Co²⁺ Activated Peroxymonosulfate Oxidation Process].

    PubMed

    Liu, Kuo; Jin, Hao; Dong, Wei; Ji, Yue-fei; Lu, Jun-he

    2016-05-15

    Sulfate radicals (SO₄·⁻) generated by Co²⁺ catalyzed activation of peroxymonosulfate (PMS) are highly oxidative and can be applied to degrade various organic pollutants. It was revealed in this research that bromide could be transformed in this process to reactive bromine species which reacted with phenol subsequently, leading to the formation of bromophenols and brominated by-products such as bromoform and dibromoacetic acid. The formation of the brominated by-products first increased and then decreased. The maximum yields of bromoform (10.3 µmol · L⁻¹) and dibromoacetic acid (14.6 µmol · L⁻¹) occurred at approximately 8 h with initial phenol, PMS, Br⁻, Co²⁺, concentrations of 0.05, 1.0, 0.2, and 5 µmol · L⁻¹, respectively. Formation of the brominated by-products decreased with increasing pH. With constant total halides, increasing Cl⁻/Br⁻ ratio decreased the total formation of halogenated by- products but generated more chlorinated byproducts. The findings of this research can provide valuable information in assessing the feasibility of SO₄·⁻ based oxidation technologies in real practice. PMID:27506036

  1. Evidence for parallel processing of sensory information controlling dauer formation in Caenorhabditis elegans.

    PubMed

    Thomas, J H; Birnby, D A; Vowels, J J

    1993-08-01

    Dauer formation in Caenorhabditis elegans is induced by chemosensation of high levels of a constitutively secreted pheromone. Seven genes defined by mutations that confer a dauer-formation constitutive phenotype (Daf-c) can be congruently divided into two groups by any of three criteria. Group 1 genes (daf-11 and daf-21) are (1) strongly synergistic with group 2 genes for their Daf-c phenotype, (2) incompletely suppressed by dauer-formation defective (Daf-d) mutations in the genes daf-3 and daf-5 and (3) strongly suppressed by Daf-d mutations in nine genes that affect the structure of chemosensory endings. Group 2 genes (daf-1, daf-4, daf-7, daf-8 and daf-14) are (1) strongly synergistic with group 1 genes for their Daf-c phenotype, (2) fully suppressed by Daf-d mutations in daf-3 and daf-5 and (3) not suppressed by Daf-d mutations in the nine genes that affect chemosensory ending structure. Mutations in each group of genes also cause distinct additional behavioral defects. We propose that these two groups of Daf-c genes act in parallel pathways that process sensory information. The two pathways are partially redundant with each other and normally act in concert to control dauer formation. PMID:8375650

  2. DECIPHERING NATURALLY-OCCURRING PB CONTAMINATION IMPACTING DRINKING WATER WELLS: SHAKER VILLAGE CATCHMENT, MAINE.

    EPA Science Inventory

    Trace Pb concentrations in groundwater within glacial deposits across Maine fluctuate considerably. Deciphering the distribution and sources of naturally occurring Pb in groundwater with only the use of conventional anomaly identification techniques presents a challenge. In a rep...

  3. The role of reconsolidation and the dynamic process of long-term memory formation and storage.

    PubMed

    Alberini, Cristina M

    2011-01-01

    It is becoming increasingly clear that the processes of memory formation and storage are exquisitely dynamic. Elucidating the nature and temporal evolution of the biological changes that accompany encoding, storage, and retrieval is key to understand memory formation. For explicit or medial temporal lobe-dependent memories that form after a discrete event and are stored for a long time, the physical changes underlying the encoding and processing of the information (memory trace or engram) remain in a fragile state for some time. However, over time, the new memory becomes increasingly resistant to disruption until it is consolidated. Retrieval or reactivation of an apparently consolidated memory can render the memory labile again, and reconsolidation is the process that occurs to mediate its restabilization. Reconsolidation also evolves with the age of the memory: Young memories are sensitive to post-reactivation disruption, but older memories are more resistant. Why does a memory become labile again if it is retrieved or reactivated? Here I suggest that the main function of reconsolidation is to contribute to the lingering consolidation process and mediate memory strengthening. I also discuss the literature and results regarding the influence of the passage of time on the reconsolidation of memory. These points have important implications for the use of reconsolidation in therapeutic settings. PMID:21436877

  4. A case study on the formation and sharing process of science classroom norms

    NASA Astrophysics Data System (ADS)

    Chang, Jina; Song, Jinwoong

    2016-03-01

    The teaching and learning of science in school are influenced by various factors, including both individual factors, such as member beliefs, and social factors, such as the power structure of the class. To understand this complex context affected by various factors in schools, we investigated the formation and sharing process of science classroom norms in connection with these factors. By examining the developmental process of science classroom norms, we identified how the norms were realized, shared, and internalized among the members. We collected data through classroom observations and interviews focusing on two elementary science classrooms in Korea. From these data, factors influencing norm formation were extracted and developed as stories about norm establishment. The results indicate that every science classroom norm was established, shared, and internalized differently according to the values ingrained in the norms, the agent of norm formation, and the members' understanding about the norm itself. The desirable norms originating from values in science education, such as having an inquiring mind, were not established spontaneously by students, but were instead established through well-organized norm networks to encourage concrete practice. Educational implications were discussed in terms of the practice of school science inquiry, cultural studies, and value-oriented education.

  5. Processing of Double-Differential Cross Sections in the New ENDF-VI Format.

    Energy Science and Technology Software Center (ESTSC)

    1987-08-28

    Version 00 GROUPXS does file handling and processing of the double-differential continuum-emission cross sections stored in the new MF6 format of ENDF/VI. It treats the energy-angle data that are supposed to be represented by a Legendre-polynomial expansion in the center-of-mass system and can do the following: (1) Conversion of MF6 data from center-of-mass system to the laboratory system, with the possibility to continue the calculation with the options (2), (3), and (4). (2) Conversion ofmore » Legendre-polynomial representation into point-wise angular data, in MF6 format. (3) Conversion of data from MF6 into MF4 + MF5 (ENDF-V). (4) Calculation of group constants, scattering matrices and transfer matrices for arbitrary group structures with a fusion micro-flux weighting spectrum (PN-approximation). The code treats only continuum reaction types that are stored in the MF6 format with the restrictions as specified for the European Fusion File (EFF1). These restrictions are not inconvenient for the purpose of fusion neutronics calculations and they facilitate relatively simple processing .« less

  6. Adsorption and Thermal Processing of Glycolaldehyde, Methyl Formate, and Acetic Acid on Graphite at 20 K.

    PubMed

    Burke, Daren J; Puletti, Fabrizio; Woods, Paul M; Viti, Serena; Slater, Ben; Brown, Wendy A

    2015-07-01

    We present the first detailed comparative study of the adsorption and thermal processing of the three astrophysically important C2O2H4 isomers glycolaldehyde, methyl formate, and acetic acid adsorbed on a graphitic grain analogue at 20 K. The ability of the individual molecule to form intermolecular hydrogen bonds is extremely important, dictating the growth modes of the ice on the surface and the measured desorption energies. Methyl formate forms only weak intermolecular bonds and hence wets the graphite surface, forming monolayer, bilayer, and multilayer ices, with the multilayer having a desorption energy of 35 kJ mol(-1). In contrast, glycolaldehyde and acetic acid dewet the surface, forming clusters even at the very lowest coverages. The strength of the intermolecular hydrogen bonding for glycolaldehyde and acetic acid is reflected in their desorption energies (46.8 and 55 kJ mol(-1), respectively), which are comparable to those measured for other hydrogen-bonded species such as water. Infrared spectra show that all three isomers undergo structural changes as a result of thermal processing. In the case of acetic acid and glycolaldehyde, this can be assigned to the formation of well-ordered, crystalline, structures where the molecules form chains of hydrogen-bonded moieties. The data reported here are of relevance to astrochemical studies of hot cores and star-forming regions and can be used to model desorption from interstellar ices during the warm up phase with particular importance for complex organic molecules. PMID:26057183

  7. Platinum Partitioning at Low Oxygen Fugacity: Implications for Core Formation Processes

    NASA Technical Reports Server (NTRS)

    Medard, E.; Martin, A. M.; Righter, K.; Lanziroti, A.; Newville, M.

    2016-01-01

    Highly siderophile elements (HSE = Au, Re, and the Pt-group elements) are tracers of silicate / metal interactions during planetary processes. Since most core-formation models involve some state of equilibrium between liquid silicate and liquid metal, understanding the partioning of highly siderophile elements (HSE) between silicate and metallic melts is a key issue for models of core / mantle equilibria and for core formation scenarios. However, partitioning models for HSE are still inaccurate due to the lack of sufficient experimental constraints to describe the variations of partitioning with key variable like temperature, pressure, and oxygen fugacity. In this abstract, we describe a self-consistent set of experiments aimed at determining the valence of platinum, one of the HSE, in silicate melts. This is a key information required to parameterize the evolution of platinum partitioning with oxygen fugacity.

  8. Star Formation in Isolated LIRGs: Clues to Star-forming Processes at Higher z

    NASA Astrophysics Data System (ADS)

    Fuentes-Carrera, Isaura; Olguín, Lorenzo; Ambrocio-Cruz, Patricia; Verley, Simon; Rosado, Margarita; Verdes-Montenegro, Lourdes; Repetto, Paolo; Vázquez, Celia; Aguilera, Verónica

    2011-12-01

    Luminous infrared galaxies (LIRGs) are galaxies with LIR > 1011 L⊙. For a star-forming galaxy to emit at a LIRG level, it must have a very high star formation rate (SFR). In the local Universe, the star formation (SF) is primarily triggered by interactions. However, at intermediate redshift, a large fraction of LIRGs are disk galaxies with little sign of recent merger activity. The question arises whether the intermediate redshift LIRGs are ``triggered'' or experiencing ``normal'', if elevated, SF. Understanding these SF processes is important since this type of systems may have contributed to 20% or more of the cosmic SFR in the early Universe. In order to address this issue we study similar systems in the Local Universe, that is isolated late-type galaxies displaying LIRG activity. We use different observational techniques in order to trace the star-forming history of these systems. Here we present preliminary results.

  9. A coherent light scanner for optical processing of large format transparencies

    NASA Technical Reports Server (NTRS)

    Callen, W. R.; Weaver, J. E.; Shackelford, R. G.; Walsh, J. R.

    1975-01-01

    A laser scanner is discussed in which the scanning beam is random-access addressable and perpendicular to the image input plane and the irradiance of the scanned beam is controlled so that a constant average irradiance is maintained after passage through the image plane. The scanner's optical system and design are described, and its performance is evaluated. It is noted that with this scanner, data in the form of large-format transparencies can be processed without the expense, space, maintenance, and precautions attendant to the operation of a high-power laser with large-aperture collimating optics. It is shown that the scanned format as well as the diameter of the scanning beam may be increased by simple design modifications and that higher scan rates can be achieved at the expense of resolution by employing acousto-optic deflectors with different relay optics.

  10. Formation processes of nanometer sized particles in low pressure Ar/CH{sub 4} rf plasmas

    SciTech Connect

    Beckers, J.; Vacaresse, G. D. G. J.; Stoffels, W. W.

    2008-09-07

    In this paper, formation and growth processes of nanometer and micrometer sized dust particles in low pressure Ar/CH{sub 4} rf (13.56 MHz) plasmas are investigated as function of temperature in the range 25-100 deg. C. During experiments the pressure was typically 0.8 mbar and the forward power to the plasma was {approx}70 Watt. Measuring the fundamental voltage, current and phase angle together with their harmonics (up to the fourth) gives a good method to monitor the creation and growth of these dust particles in time. Furthermore, laser light scattering measurements are performed to give information about the dust particle density. It has been shown that dust particle formation in these conditions depends greatly on temperature.