WorldWideScience

Sample records for junction formation processes

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

    Science.gov (United States)

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

    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.

  2. Formation of bubbles in a multisection flow-focusing junction.

    Science.gov (United States)

    Hashimoto, Michinao; Whitesides, George M

    2010-05-01

    The formation of bubbles in a flow-focusing (FF) junction comprising multiple rectangular sections is described. The simplest junctions comprise two sections (throat and orifice). Systematic investigation of the influence on the formation of bubbles of the flow of liquid and the geometry of the junction identifies regimes that generate monodisperse, bidisperse, and tridisperse trains of bubbles. The mechanisms by which these junctions form monodisperse and bidisperse bubbles are inferred from the shapes of the gas thread during breakup: these mechanisms differ primarily by the process in which the gas thread collapses in the throat and/or orifice. The dynamic self-assembly of bidisperse bubbles leads to unexpected groupings of bubbles during their flow along the outlet channel.

  3. Defect formation in long Josephson junctions

    DEFF Research Database (Denmark)

    Gordeeva, Anna; Pankratov, Andrey

    2010-01-01

    We study numerically a mechanism of vortex formation in a long Josephson junction within the framework of the one-dimensional sine-Gordon model. This mechanism is switched on below the critical temperature. It is shown that the number of fluxons versus velocity of cooling roughly scales according...

  4. Model Building to Facilitate Understanding of Holliday Junction and Heteroduplex Formation, and Holliday Junction Resolution

    Science.gov (United States)

    Selvarajah, Geeta; Selvarajah, Susila

    2016-01-01

    Students frequently expressed difficulty in understanding the molecular mechanisms involved in chromosomal recombination. Therefore, we explored alternative methods for presenting the two concepts of the double-strand break model: Holliday junction and heteroduplex formation, and Holliday junction resolution. In addition to a lecture and…

  5. Formation and stability of ridge-ridge-ridge triple junctions in rheologically realistic lithosphere model

    Science.gov (United States)

    Gerya, Taras; Burov, Evgueni

    2015-04-01

    Triple junctions are probably the most remarkable features of plate boundaries since their presence constitutes one of the major demonstrations of plate tectonics theory. Divergent (R-R-R) triple junctions (at 120° and T junctions) are particular ones since their stability depends on the exact values of the relative velocities of plate divergence and hence is strongly affected by plate rheology and processes of crustal accretion. The mechanisms of their formation and long-term steadiness are not well understood even though it is commonly accepted, generally based on common sense, that the geometry and stability of triple junctions should be related to the intuitively acceptable geometric considerations that 3-branch configurations should be "stable" over the time on a 3D Earth surface. That said, most plate boundaries are in fact 2D in terms that they involve only two plates, while junctions with 3 and more branches, if even mechanically not excluded, are generally short-lived and hence rarely observed at tectonic scale. Indeed, it has been long-time suggested that triple junctions result from evolution of short-lived quadruple junctions, yet, without providing a consistent mechanical explanation or experimental demonstration of this process, due to the rheological complexity of the lithosphere and that of strain localization and crustal accretion processes. For example, it is supposed that R-R-R junctions form as result of axisymmetric mantle upwellings. However, impingement of buoyant fluid on a non-pre-stressed lithosphere should result in multiple radial cracks, as is well known from previous analog and numerical experiments. In case of uni-directionally pre-stressed lithosphere, it has also shown that linear 2D rift structures should be formed. Therefore, a complete 3D thermos-mechanically consistent approach is needed to understand the processes of formation of multi-branch junctions. With this goal we here reproduce and study the processes of multi

  6. The Rho target PRK2 regulates apical junction formation in human bronchial epithelial cells.

    Science.gov (United States)

    Wallace, Sean W; Magalhaes, Ana; Hall, Alan

    2011-01-01

    Rho GTPases regulate multiple signaling pathways to control a number of cellular processes during epithelial morphogenesis. To investigate the downstream pathways through which Rho regulates epithelial apical junction formation, we screened a small interfering RNA (siRNA) library targeting 28 known Rho target proteins in 16HBE human bronchial epithelial cells. This led to the identification of the serine-threonine kinase PRK2 (protein kinase C-related kinase 2, also called PKN2). Depletion of PRK2 does not block the initial formation of primordial junctions at nascent cell-cell contacts but does prevent their maturation into apical junctions. PRK2 is recruited to primordial junctions, and this localization depends on its C2-like domain. Rho binding is essential for PRK2 function and also facilitates PRK2 recruitment to junctions. Kinase-dead PRK2 acts as a dominant-negative mutant and prevents apical junction formation. We conclude that PRK2 is recruited to nascent cell-cell contacts through its C2-like and Rho-binding domains and promotes junctional maturation through a kinase-dependent pathway.

  7. Processing of Superconductor-Normal-Superconductor Josephson Edge Junctions

    Science.gov (United States)

    Kleinsasser, A. W.; Barner, J. B.

    1997-01-01

    The electrical behavior of epitaxial superconductor-normal-superconductor (SNS) Josephson edge junctions is strongly affected by processing conditions. Ex-situ processes, utilizing photoresist and polyimide/photoresist mask layers, are employed for ion milling edges for junctions with Yttrium-Barium-Copper-Oxide (YBCO) electrodes and primarily Co-doped YBCO interlayers.

  8. Droplet formation in microfluidic T-junction generators operating in the transitional regime. II. Modeling.

    Science.gov (United States)

    Glawdel, Tomasz; Elbuken, Caglar; Ren, Carolyn L

    2012-01-01

    This is the second part of a two-part study on the generation of droplets at a microfluidic T-junction operating in the transition regime. In the preceding paper [Phys. Rev. E 85, 016322 (2012)], we presented our experimental observations of droplet formation and decomposed the process into three sequential stages defined as the lag, filling, and necking stages. Here we develop a model that describes the performance of microfluidic T-junction generators working in the squeezing to transition regimes where confinement of the droplet dominates the formation process. The model incorporates a detailed geometric description of the drop shape during the formation process combined with a force balance and necking criteria to define the droplet size, production rate, and spacing. The model inherently captures the influence of the intersection geometry, including the channel width ratio and height-to-width ratio, capillary number, and flow ratio, on the performance of the generator. The model is validated by comparing it to speed videos of the formation process for several T-junction geometries across a range of capillary numbers and viscosity ratios.

  9. The Rho Target PRK2 Regulates Apical Junction Formation in Human Bronchial Epithelial Cells ▿

    OpenAIRE

    Wallace, Sean W.; Magalhaes, Ana; Hall, Alan

    2010-01-01

    Rho GTPases regulate multiple signaling pathways to control a number of cellular processes during epithelial morphogenesis. To investigate the downstream pathways through which Rho regulates epithelial apical junction formation, we screened a small interfering RNA (siRNA) library targeting 28 known Rho target proteins in 16HBE human bronchial epithelial cells. This led to the identification of the serine-threonine kinase PRK2 (protein kinase C-related kinase 2, also called PKN2). Depletion of...

  10. Systematic study of shallow junction formation on germanium substrates

    DEFF Research Database (Denmark)

    Hellings, Geert; Rosseel, Erik; Clarysse, Trudo

    2011-01-01

    Published results on Ge junctions are benchmarked systematically using RS–XJ plots. The electrical activation level required to meet the ITRS targets is calculated. Additionally, new results are presented on shallow furnace-annealed B junctions and shallow laser-annealed As junctions. Co-implanti...

  11. APP-dependent glial cell line-derived neurotrophic factor gene expression drives neuromuscular junction formation.

    Science.gov (United States)

    Stanga, Serena; Zanou, Nadège; Audouard, Emilie; Tasiaux, Bernadette; Contino, Sabrina; Vandermeulen, Gaëlle; René, Frédérique; Loeffler, Jean-Philippe; Clotman, Frédéric; Gailly, Philippe; Dewachter, Ilse; Octave, Jean-Noël; Kienlen-Campard, Pascal

    2016-05-01

    Besides its crucial role in the pathogenesis of Alzheimer's disease, the knowledge of amyloid precursor protein (APP) physiologic functions remains surprisingly scarce. Here, we show that APP regulates the transcription of the glial cell line-derived neurotrophic factor (GDNF). APP-dependent regulation of GDNF expression affects muscle strength, muscular trophy, and both neuronal and muscular differentiation fundamental for neuromuscular junction (NMJ) maturation in vivo In a nerve-muscle coculture model set up to modelize NMJ formation in vitro, silencing of muscular APP induces a 30% decrease in secreted GDNF levels and a 40% decrease in the total number of NMJs together with a significant reduction in the density of acetylcholine vesicles at the presynaptic site and in neuronal maturation. These defects are rescued by GDNF expression in muscle cells in the conditions where muscular APP has been previously silenced. Expression of GDNF in muscles of amyloid precursor protein null mice corrected the aberrant synaptic morphology of NMJs. Our findings highlight for the first time that APP-dependent GDNF expression drives the process of NMJ formation, providing new insights into the link between APP gene regulatory network and physiologic functions.-Stanga, S., Zanou, N., Audouard, E., Tasiaux, B., Contino, S., Vandermeulen, G., René, F., Loeffler, J.-P., Clotman, F., Gailly, P., Dewachter, I., Octave, J.-N., Kienlen-Campard, P. APP-dependent glial cell line-derived neurotrophic factor gene expression drives neuromuscular junction formation.

  12. Evaluation of the formation of a junctional DNA nanostructure through annealing curve analysis.

    Science.gov (United States)

    Shin, Seung Won; Park, Kyung Soo; Um, Soong Ho

    2015-02-20

    During the self-assembly of different numbers of oligonucleotides comprising junctional DNA nanostructures, a change in environmental variables (e.g., temperature or salt concentration) has a substantial influence on the final products. Further, distinctive annealing temperatures of oligonucleotides are observed depending on the state of hybridization. Here, we present an evaluation of the annealing characteristics of oligonucleotides for the formation of a simple junctional DNA nanostructure using an annealing curve analysis. This method may be useful for analyzing the formation of complex junctional DNA nanostructures.

  13. Holliday junction processing enzymes as guardians of genome stability.

    Science.gov (United States)

    Sarbajna, Shriparna; West, Stephen C

    2014-09-01

    Holliday junctions (HJs) are four-stranded DNA intermediates that arise during the recombinational repair of DNA double-strand breaks (DSBs). Their timely removal is crucial for faithful chromosome segregation and genome stability. In mammalian cells, HJs are processed by the BTR (BLM-topoisomerase IIIα-RMI1-RMI2) complex, the SLX-MUS (SLX1-SLX4-MUS81-EME1) complex, and the GEN1 resolvase. Recent studies have linked the deficiency of one or more of these enzymes to perturbed DNA replication, impaired crosslink repair, chromosomal instability, and defective mitoses, coupled with the transmission of widespread DNA damage and high levels of mortality. We review these key advances and how they have cemented the status of HJ-processing enzymes as guardians of genome integrity and viability in mammalian cells. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Formation and branch migration of Holliday junctions mediated by eukaryotic recombinases.

    Science.gov (United States)

    Murayama, Yasuto; Kurokawa, Yumiko; Mayanagi, Kouta; Iwasaki, Hiroshi

    2008-02-21

    Holliday junctions (HJs) are key intermediates in homologous recombination and are especially important for the production of crossover recombinants. Bacterial RecA family proteins promote the formation and branch migration of HJs in vitro by catalysing a reciprocal DNA-strand exchange reaction between two duplex DNA molecules, one of which contains a single-stranded DNA region that is essential for initial nucleoprotein filament formation. This activity has been reported only for prokaryotic RecA family recombinases, although eukaryotic homologues are also essential for HJ production in vivo. Here we show that fission yeast (Rhp51) and human (hRad51) RecA homologues promote duplex-duplex DNA-strand exchange in vitro. As with RecA, a HJ is formed between the two duplex DNA molecules, and reciprocal strand exchange proceeds through branch migration of the HJ. In contrast to RecA, however, strand exchange mediated by eukaryotic recombinases proceeds in the 3'-->5' direction relative to the single-stranded DNA region of the substrate DNA. The opposite polarity of Rhp51 makes it especially suitable for the repair of DNA double-strand breaks, whose repair is initiated at the processed ends of breaks that have protruding 3' termini.

  15. Extracellular domains play different roles in gap junction formation and docking compatibility.

    Science.gov (United States)

    Bai, Donglin; Wang, Ao Hong

    2014-02-15

    GJ (gap junction) channels mediate direct intercellular communication and play an important role in many physiological processes. Six connexins oligomerize to form a hemichannel and two hemichannels dock together end-to-end to form a GJ channel. Connexin extracellular domains (E1 and E2) have been shown to be important for the docking, but the molecular mechanisms behind the docking and formation of GJ channels are not clear. Recent developments in atomic GJ structure and functional studies on a series of connexin mutants revealed that E1 and E2 are likely to play different roles in the docking. Non-covalent interactions at the docking interface, including hydrogen bonds, are predicted to form between interdocked extracellular domains. Protein sequence alignment analysis on the docking compatible/incompatible connexins indicate that the E1 domain is important for the formation of the GJ channel and the E2 domain is important in the docking compatibility in heterotypic channels. Interestingly, the hydrogen-bond forming or equivalent residues in both E1 and E2 domains are mutational hot spots for connexin-linked human diseases. Understanding the molecular mechanisms of GJ docking can assist us to develop novel strategies in rescuing the disease-linked connexin mutants.

  16. Claudin-16 Deficiency Impairs Tight Junction Function in Ameloblasts, Leading to Abnormal Enamel Formation.

    Science.gov (United States)

    Bardet, Claire; Courson, Frédéric; Wu, Yong; Khaddam, Mayssam; Salmon, Benjamin; Ribes, Sandy; Thumfart, Julia; Yamaguti, Paulo M; Rochefort, Gael Y; Figueres, Marie-Lucile; Breiderhoff, Tilman; Garcia-Castaño, Alejandro; Vallée, Benoit; Le Denmat, Dominique; Baroukh, Brigitte; Guilbert, Thomas; Schmitt, Alain; Massé, Jean-Marc; Bazin, Dominique; Lorenz, Georg; Morawietz, Maria; Hou, Jianghui; Carvalho-Lobato, Patricia; Manzanares, Maria Cristina; Fricain, Jean-Christophe; Talmud, Deborah; Demontis, Renato; Neves, Francisco; Zenaty, Delphine; Berdal, Ariane; Kiesow, Andreas; Petzold, Matthias; Menashi, Suzanne; Linglart, Agnes; Acevedo, Ana Carolina; Vargas-Poussou, Rosa; Müller, Dominik; Houillier, Pascal; Chaussain, Catherine

    2016-03-01

    Claudin-16 protein (CLDN16) is a component of tight junctions (TJ) with a restrictive distribution so far demonstrated mainly in the kidney. Here, we demonstrate the expression of CLDN16 also in the tooth germ and show that claudin-16 gene (CLDN16) mutations result in amelogenesis imperfecta (AI) in the 5 studied patients with familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC). To investigate the role of CLDN16 in tooth formation, we studied a murine model of FHHNC and showed that CLDN16 deficiency led to altered secretory ameloblast TJ structure, lowering of extracellular pH in the forming enamel matrix, and abnormal enamel matrix protein processing, resulting in an enamel phenotype closely resembling human AI. This study unravels an association of FHHNC owing to CLDN16 mutations with AI, which is directly related to the loss of function of CLDN16 during amelogenesis. Overall, this study indicates for the first time the importance of a TJ protein in tooth formation and underlines the need to establish a specific dental follow-up for these patients. © 2015 American Society for Bone and Mineral Research.

  17. Cluster-formation in the Rosette molecular cloud at the junctions of filaments

    CERN Document Server

    Schneider, N; Hennemann, M; Motte, F; Didelon, P; Federrath, C; Bontemps, S; Di Francesco, J; Arzoumanian, D; Minier, V; André, Ph; Hill, T; Zavagno, A; Nguyen-Luong, Q; Attard, M; Bernard, J -Ph; Elia, D; Fallscheer, C; Griffin, M; Kirk, J; Klessen, R; Könyves, V; Martin, P; Men'shchikov, A; Palmeirim, P; Peretto, N; Pestalozzi, M; Russeil, D; Sadavoy, S; Sousbie, T; Testi, L; Tremblin, P; Ward-Thompson, D; White, G

    2012-01-01

    For many years feedback processes generated by OB-stars in molecular clouds, including expanding ionization fronts, stellar winds, or UV-radiation, have been proposed to trigger subsequent star formation. However, hydrodynamic models including radiation and gravity show that UV-illumination has little or no impact on the global dynamical evolution of the cloud. The Rosette molecular cloud, irradiated by the NGC2244 cluster, is a template region for triggered star-formation, and we investigated its spatial and density structure by applying a curvelet analysis, a filament-tracing algorithm (DisPerSE), and probability density functions (PDFs) on Herschel column density maps, obtained within the HOBYS key program. The analysis reveals not only the filamentary structure of the cloud but also that all known infrared clusters except one lie at junctions of filaments, as predicted by turbulence simulations. The PDFs of sub-regions in the cloud show systematic differences. The two UV-exposed regions have a double-peak...

  18. Sparse Matrix Vector Processing Formats

    NARCIS (Netherlands)

    Stathis, P.T.

    2004-01-01

    In this dissertation we have identified vector processing shortcomings related to the efficient storing and processing of sparse matrices. To alleviate existent problems we propose two storage formats denoted as Block Based Compression Storage (BBCS) format and Hierarchical Sparse Matrix (HiSM) stor

  19. Synthesis of silicon carbide nano-junctions in a catalyst-assisted process

    Science.gov (United States)

    Deng, S. Z.; Wu, Z. S.; Zhou, Jun; Xu, N. S.; Chen, Jian; Chen, Jun

    2002-10-01

    Nano-Y-junctions and nano-staggered-junctions that are formed by SiC nanorods were grown at elevated temperatures in a catalyst-assisted process. Transmission electron microscopy shows that the nanorods are typically around 20 nm in diameter and around 2 μm in length. Nanorods with diameter down to below 2 nm may be observed from nano-junctions. High-resolution transmission electron microscopy shows that the nanorods are crystalline β-SiC.

  20. Dynamic formation of microenvironments at the myotendinous junction correlates with muscle fiber morphogenesis in zebrafish

    OpenAIRE

    Snow, Chelsi J.; Henry, Clarissa A.

    2008-01-01

    Muscle development involves the specification and morphogenesis of muscle fibers that attach to tendons. After attachment, muscles and tendons then function as an integrated unit to transduce force to the skeletal system and stabilize joints. The attachment site is the myotendinous junction, or MTJ, and is the primary site of force transmission. We find that attachment of fast-twitch myofibers to the MTJ correlates with the formation of novel microenvironments within the MTJ. The expression o...

  1. Droplet formation in microfluidic T-junction generators operating in the transitional regime. III. Dynamic surfactant effects.

    Science.gov (United States)

    Glawdel, Tomasz; Ren, Carolyn L

    2012-08-01

    This study extends our previous work on droplet generation in microfluidic T-junction generators to include dynamic interfacial tension effects created by the presence of surfactants. In Paper I [T. Glawdel, C. Elbuken, and C. L. Ren, Phys. Rev. E 85, 016322 (2012)], we presented experimental findings regarding the formation process in the squeezing-to-transition regime, and in Paper II [T. Glawdel, C. Elbuken, and C. L. Ren, Phys. Rev. E 85, 016323 (2012)] we developed a theoretical model that describes the performance of T-junction generators without surfactants. Here we study dynamic interfacial tension effects for two surfactants, one with a small molecular weight that adsorbs quickly, and the other with a large molecular weight that adsorbs slowly. Using the force balance developed in Paper II we extract the dynamic interfacial tension from high speed videos obtained during experiments. We then develop a theoretical model to predict the dynamic interfacial tension in microfluidic T-junction generators as a function of the surfactant properties, flow conditions, and generator design. This model is then incorporated into the overall model for generator performance to effectively predict the size of droplets produced when surfactants are present.

  2. Time-resolved mixing and flow-field measurements during droplet formation in a flow-focusing junction

    Science.gov (United States)

    Carrier, Odile; Gökhan Ergin, F.; Li, Huai-Zhi; Watz, Bo B.; Funfschilling, Denis

    2015-08-01

    Highly monodispersed emulsions can be produced in microfluidic flow-focusing junctions (Anna et al 2003 Appl. Phys. Lett. 82 364-6, Baroud et al 2010 Lab Chip 10 2032-45). This is the reason why many industrial processes in the medical industry among others are based on droplet manipulation and involve at some point a step of dripping within a junction. However, only a few studies have focused on the flow field inside and outside the droplet, even though it is a necessary step for understanding the physical mechanism involved and for modeling the droplet formation process. Water-in-oil emulsions are produced in flow-focusing junctions of square cross sections. The fluids constituting the emulsion are (i) a 5.0 mPa·s silicon oil for the oil phase and (ii) distilled water containing 2.0 wt% of sodium dodecyl sulfate surfactant for the aqueous phase. Time-resolved shadow particle images are acquired using a microscale particle image velocimetry (µPIV) system and flow fields are calculated using an adaptive PIV algorithm in combination with dynamic masking. Inside the microchannel and in the permanent regime, the droplet has an internal circulation that has been well established by Sarrazin et al (AICHE J. 52 4061-70). But during the formation of a droplet in a flow-focusing junction, the flow field is not so well known, and the circulation in the finger flows forward along the sides and returns along the center. The mechanism can be described in terms of four distinct steps: droplet growth, necking, rupture, and recoil. The liquid expelled from the neck just before rupture is also well observed. The flow field and mixing are measured in detail during a complete cycle of formation of a main droplet and satellite droplets using high-speed imaging. This allows us to develop a better understanding of the different forces that are present and of the physical mechanism of droplet formation.

  3. The multifaceted planetesimal formation process

    CERN Document Server

    Johansen, Anders; Tanaka, Hidekazu; Ormel, Chris; Bizzarro, Martin; Rickman, Hans

    2014-01-01

    Accumulation of dust and ice particles into planetesimals is an important step in the planet formation process. Planetesimals are the seeds of both terrestrial planets and the solid cores of gas and ice giants forming by core accretion. Left-over planetesimals in the form of asteroids, trans-Neptunian objects and comets provide a unique record of the physical conditions in the solar nebula. Debris from planetesimal collisions around other stars signposts that the planetesimal formation process, and hence planet formation, is ubiquitous in the Galaxy. The planetesimal formation stage extends from micrometer-sized dust and ice to bodies which can undergo run-away accretion. The latter ranges in size from 1 km to 1000 km, dependent on the planetesimal eccentricity excited by turbulent gas density fluctuations. Particles face many barriers during this growth, arising mainly from inefficient sticking, fragmentation and radial drift. Two promising growth pathways are mass transfer, where small aggregates transfer u...

  4. Interfering amino terminal peptides and functional implications for heteromeric gap junction formation

    Directory of Open Access Journals (Sweden)

    Richard David Veenstra

    2013-05-01

    Full Text Available Connexin43 (Cx43 is widely expressed in many different tissues of the human body. In cells of some organs, Cx43 is co-expressed with other connexins (Cx, including Cx46 and Cx50 in lens, Cx40 in atrium, Purkinje fibers, and the blood vessel wall, Cx45 in heart, and Cx37 in the ovary. Interactions with the co-expressed connexins may have profound functional implications. The abilities of Cx37, Cx45, Cx46, and Cx50 to function in heteromeric gap junction combinations with Cx43 are well documented. Different studies disagree regarding the ability of Cx43 and Cx40 to produce functional heteromeric gap junctions with each other. We review previous studies regarding the heteromeric interactions of Cx43. The possibility of negative functional interactions between the cytoplasmic pore-forming amino terminal (NT domains of these connexins was assessed using pentameric connexin sequence-specific NT domain (iNT peptides applied to cells expressing homomeric Cx40, Cx37, Cx45, Cx46, and Cx50 gap junctions. A Cx43 iNT peptide corresponding to amino acids 9 to 13 (Ac-KLLDK-NH2 specifically inhibited the electrical coupling of Cx40 gap junctions in a transjunctional (Vj voltage-dependent manner without affecting the function of homologous Cx37, Cx46, Cx50, and Cx45 gap junctions. A Cx40 iNT (Ac-EFLEE-OH peptide counteracted the Vj-dependent block of Cx40 gap junctions, whereas a similarly charged Cx50 iNT (Ac-EEVNE-OH peptide did not, suggesting that these NT domain interactions are not solely based on electrostatics. These data are consistent with functional Cx43 heteromeric gap junction formation with Cx37, Cx45, Cx46, and Cx50 and suggest that Cx40 uniquely experiences functional suppressive interactions with a Cx43 NT domain sequence. These findings present unique functional implications about the heteromeric interactions between Cx43 and Cx40 that may influence cardiac conduction in atrial myocardium and the specialized conduction system.

  5. Parametric Optical Signal Processing in Silicon Waveguides with Reverse-biased p-i-n Junctions

    DEFF Research Database (Denmark)

    Peucheret, C.; Da Ros, Francesco; Vukovic, Dragana;

    2014-01-01

    The use of silicon-on-insulator waveguides with free carriers removal using a reverse-biased p-i-n junction for parametric optical signal processing is reviewed. High-efficiency wavelength conversion and phase-sensitive regeneration are reported.......The use of silicon-on-insulator waveguides with free carriers removal using a reverse-biased p-i-n junction for parametric optical signal processing is reviewed. High-efficiency wavelength conversion and phase-sensitive regeneration are reported....

  6. The multifaceted planetesimal formation process

    DEFF Research Database (Denmark)

    Johansen, Anders; Blum, Jürgen; Tanaka, Hidekazu

    2013-01-01

    Accumulation of dust and ice particles into planetesimals is an important step in the planet formation process. Planetesimals are the seeds of both terrestrial planets and the solid cores of gas and ice giants forming by core accretion. Left-over planetesimals in the form of asteroids, trans-Nept...

  7. Fluid displacement during droplet formation at microfluidic flow-focusing junctions.

    Science.gov (United States)

    Huang, Haishui; He, Xiaoming

    2015-11-07

    Microdroplets and microcapsules have been widely produced using microfluidic flow-focusing junctions for biomedical and chemical applications. However, the multiphase microfluidic flow at the flow-focusing junction has not been well investigated. In this study, the displacement of two (core and shell) aqueous fluids that disperse into droplets altogether in a carrier oil emulsion was investigated both numerically and experimentally. It was found that extensive displacement of the two aqueous fluids within the droplet during its formation could occur as a result of the shear effect of the carrier fluid and the capillary effect of interfacial tension. We further identified that the two mechanisms of fluid displacement can be evaluated by two dimensionless parameters. The quantitative relationship between the degree of fluid displacement and these two dimensionless parameters was determined experimentally. Finally, we demonstrated that the degree of fluid displacement could be controlled to generate hydrogel microparticles of different morphologies using planar or nonplanar flow-focusing junctions. These findings should provide useful guidance to the microfluidic production of microscale droplets or capsules for various biomedical and chemical applications.

  8. Identification of RecQL1 as a Holliday junction processing enzyme in human cell lines

    Science.gov (United States)

    LeRoy, Gary; Carroll, Robert; Kyin, Saw; Seki, Masayuki; Cole, Michael D.

    2005-01-01

    Homologous recombination provides an effective way to repair DNA double-strand breaks (DSBs) and is required for genetic recombination. During the process of homologous recombination, a heteroduplex DNA structure, or a ‘Holliday junction’ (HJ), is formed. The movement, or branch migration, of this junction is necessary for recombination to proceed correctly. In prokaryotes, the RecQ protein or the RuvA/RuvB protein complex can promote ATP-dependent branch migration of Holliday junctions. Much less is known about the processing of Holliday junctions in eukaryotes. Here, we identify RecQL1 as a predominant ATP-dependent, HJ branch migrator present in human nuclear extracts. A reduction in the level of RecQL1 induced by RNA interference in HeLa cells leads to an increase in sister chromatid exchange. We propose that RecQL1 is involved in the processing of Holliday junctions in human cells. PMID:16260474

  9. Synthesis of magnetic tunnel junctions with full in situ atomic layer and chemical vapor deposition processes

    Energy Technology Data Exchange (ETDEWEB)

    Mantovan, R., E-mail: roberto.mantovan@mdm.imm.cnr.it [Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza (Italy); Vangelista, S.; Kutrzeba-Kotowska, B.; Cocco, S.; Lamperti, A.; Tallarida, G. [Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Mameli, D. [Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza (Italy); Dipartimento di Scienze Chimiche, Universita di Cagliari, Cittadella Universitaria, 09042 Monserrato, Cagliari (Italy); Fanciulli, M. [Laboratorio MDM, IMM-CNR, Via C. Olivetti 2, 20864 Agrate Brianza (Italy); Dipartimento di Scienza dei Materiali, Universita degli studi Milano-Bicocca, Via R Cozzi 53, 20125 Milano (Italy)

    2012-05-01

    Magnetic tunnel junctions, i.e. the combination of two ferromagnetic electrodes separated by an ultrathin tunnel oxide barrier, are core elements in a large variety of spin-based devices. We report on the use of combined chemical vapor and atomic layer deposition processes for the synthesis of magnetic tunnel junctions with no vacuum break. Structural, chemical and morphological characterizations of selected ferromagnetic and oxide layers are reported, together with the evidence of tunnel magnetoresistance effect in patterned Fe/MgO/Co junctions.

  10. Lattice Boltzmann simulation of droplet formation in T-junction geometries

    Science.gov (United States)

    Busuioc, Sergiu; Ambruş, Victor E.; Sofonea, Victor

    2017-01-01

    The formation of droplets in T-junction configurations is investigated using a two-dimensional Lattice Boltzmann model for liquid-vapor systems. We use an expansion of the equilibrium distribution function with respect to Hermite polynomials and an off-lattice velocity set. To evolve the distribution functions we use the second order corner transport upwind numerical scheme and a third order scheme is used to compute the gradient operators in the force term. The droplet formation successfully recovers the squeezing, dripping and jetting regimes. We find that the droplet length decreases proportionally with the flow rate of the continuous phase and increases with the flow rate of the dispersed phase in all simulation configurations and has a linear dependency on the surface tension parameter κ.

  11. Rapid gas hydrate formation process

    Science.gov (United States)

    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.

  12. Insular dentin formation pattern in human odontogenesis in relation to the scalloped dentino-enamel junction.

    Science.gov (United States)

    Radlanski, Ralf J; Renz, Herbert

    2007-01-01

    This study is a first report on the modality of early dentin formation in respect to the scalloped pattern of the dentino-enamel junction (DEJ). We applied scanning electron microscopy (SEM), transmission electron microscopy (TEM), histological serial sections, and three-dimensional (3D) reconstructions. TEM and SEM showed scallops and secondary scallops on the DEJ of deciduous dental primordia and on deciduous teeth with the enamel cap removed. This peculiar outline of the DEJ requires a specific dentin formation pattern; histological sections showed that dentin formation began at the brims of the scallops, seen as triangular spikes in serial sections. The dentin formation front was not uniform; instead, it was characterized by multiple, insular forming centers, as revealed by our 3D reconstructions. As thicker dentin layers formed, the islands became confluent. Factors are discussed, which may lead to crimpling of the inner enamel epithelium, and maintained as the scalloped pattern of the DEJ develops. Signaling patterns in accordance with the insular dentin formation are unknown so far.

  13. The multifaceted planetesimal formation process

    DEFF Research Database (Denmark)

    Johansen, Anders; Blum, Jürgen; Tanaka, Hidekazu

    2013-01-01

    Accumulation of dust and ice particles into planetesimals is an important step in the planet formation process. Planetesimals are the seeds of both terrestrial planets and the solid cores of gas and ice giants forming by core accretion. Left-over planetesimals in the form of asteroids, trans...... micrometer-sized dust and ice to bodies which can undergo run-away accretion. The latter ranges in size from 1 km to 1000 km, dependent on the planetesimal eccentricity excited by turbulent gas density fluctuations. Particles face many barriers during this growth, arising mainly from inefficient sticking...

  14. JNK signaling regulates E-cadherin junctions in germline cysts and determines primordial follicle formation in mice.

    Science.gov (United States)

    Niu, Wanbao; Wang, Ye; Wang, Zhengpin; Xin, Qiliang; Wang, Yijing; Feng, Lizhao; Zhao, Lihua; Wen, Jia; Zhang, Hua; Wang, Chao; Xia, Guoliang

    2016-05-15

    Physiologically, the size of the primordial follicle pool determines the reproductive lifespan of female mammals, while its establishment largely depends on a process of germline cyst breakdown during the perinatal period. The mechanisms regulating this process are poorly understood. Here we demonstrate that c-Jun amino-terminal kinase (JNK) signaling is crucial for germline cyst breakdown and primordial follicle formation. JNK was specifically localized in oocytes and its activity increased as germline cyst breakdown progressed. Importantly, disruption of JNK signaling with a specific inhibitor (SP600125) or knockdown technology (Lenti-JNK-shRNAs) resulted in significantly suppressed cyst breakdown and primordial follicle formation in cultured mouse ovaries. Our results show that E-cadherin is intensely expressed in germline cysts, and that its decline is necessary for oocyte release from the cyst. However, inhibition of JNK signaling leads to aberrantly enhanced localization of E-cadherin at oocyte-oocyte contact sites. WNT4 expression is upregulated after SP600125 treatment. Additionally, similar to the effect of SP600125 treatment, WNT4 overexpression delays cyst breakdown and is accompanied by abnormal E-cadherin expression patterns. In conclusion, our results suggest that JNK signaling, which is inversely correlated with WNT4, plays an important role in perinatal germline cyst breakdown and primordial follicle formation by regulating E-cadherin junctions between oocytes in mouse ovaries. © 2016. Published by The Company of Biologists Ltd.

  15. Afadin regulates puncta adherentia junction formation and presynaptic differentiation in hippocampal neurons.

    Directory of Open Access Journals (Sweden)

    Daisaku Toyoshima

    Full Text Available The formation and remodeling of mossy fiber-CA3 pyramidal cell synapses in the stratum lucidum of the hippocampus are implicated in the cellular basis of learning and memory. Afadin and its binding cell adhesion molecules, nectin-1 and nectin-3, together with N-cadherin, are concentrated at puncta adherentia junctions (PAJs in these synapses. Here, we investigated the roles of afadin in PAJ formation and presynaptic differentiation in mossy fiber-CA3 pyramidal cell synapses. At these synapses in the mice in which the afadin gene was conditionally inactivated before synaptogenesis by using nestin-Cre mice, the immunofluorescence signals for the PAJ components, nectin-1, nectin-3 and N-cadherin, disappeared almost completely, while those for the presynaptic components, VGLUT1 and bassoon, were markedly decreased. In addition, these signals were significantly decreased in cultured afadin-deficient hippocampal neurons. Furthermore, the interevent interval of miniature excitatory postsynaptic currents was prolonged in the cultured afadin-deficient hippocampal neurons compared with control neurons, indicating that presynaptic functions were suppressed or a number of synapse was reduced in the afadin-deficient neurons. Analyses of presynaptic vesicle recycling and paired recordings revealed that the cultured afadin-deficient neurons showed impaired presynaptic functions. These results indicate that afadin regulates both PAJ formation and presynaptic differentiation in most mossy fiber-CA3 pyramidal cell synapses, while in a considerable population of these neurons, afadin regulates only PAJ formation but not presynaptic differentiation.

  16. Kartogenin induces cartilage-like tissue formation in tendon-bone junction

    Institute of Scientific and Technical Information of China (English)

    Jianying Zhang; James H-C Wang

    2014-01-01

    Tendon-bone junctions (TBJs) are frequently injured, especially in athletic settings. Healing of TBJ injuries is slow and is often repaired with scar tissue formation that compromises normal function. This study explored the feasibility of using kartogenin (KGN), a biocompound, to enhance the healing of injured TBJs. We first determined the effects of KGN on the proliferation and chondrogenic differentiation of rabbit bone marrow stromal cells (BMSCs) and patellar tendon stem/progenitor cells (PTSCs) in vitro. KGN enhanced cell proliferation in both cell types in a concentration-dependent manner and induced chondrogenic differentiation of stem cells, as demonstrated by high expression levels of chondrogenic markers aggrecan, collagen II and Sox-9. Besides, KGN induced the formation of cartilage-like tissues in cell cultures, as observed through the staining of abundant proteoglycans, collagen II and osteocalcin. When injected into intact rat patellar tendons in vivo, KGN induced cartilage-like tissue formation in the injected area. Similarly, when KGN was injected into experimentally injured rat Achilles TBJs, wound healing in the TBJs was enhanced, as evidenced by the formation of extensive cartilage-like tissues. These results suggest that KGN may be used as an effective cell-free clinical therapy to enhance the healing of injured TBJs.

  17. Afadin Regulates Puncta Adherentia Junction Formation and Presynaptic Differentiation in Hippocampal Neurons

    Science.gov (United States)

    Toyoshima, Daisaku; Mandai, Kenji; Maruo, Tomohiko; Supriyanto, Irwan; Togashi, Hideru; Inoue, Takahito; Mori, Masahiro; Takai, Yoshimi

    2014-01-01

    The formation and remodeling of mossy fiber-CA3 pyramidal cell synapses in the stratum lucidum of the hippocampus are implicated in the cellular basis of learning and memory. Afadin and its binding cell adhesion molecules, nectin-1 and nectin-3, together with N-cadherin, are concentrated at puncta adherentia junctions (PAJs) in these synapses. Here, we investigated the roles of afadin in PAJ formation and presynaptic differentiation in mossy fiber-CA3 pyramidal cell synapses. At these synapses in the mice in which the afadin gene was conditionally inactivated before synaptogenesis by using nestin-Cre mice, the immunofluorescence signals for the PAJ components, nectin-1, nectin-3 and N-cadherin, disappeared almost completely, while those for the presynaptic components, VGLUT1 and bassoon, were markedly decreased. In addition, these signals were significantly decreased in cultured afadin-deficient hippocampal neurons. Furthermore, the interevent interval of miniature excitatory postsynaptic currents was prolonged in the cultured afadin-deficient hippocampal neurons compared with control neurons, indicating that presynaptic functions were suppressed or a number of synapse was reduced in the afadin-deficient neurons. Analyses of presynaptic vesicle recycling and paired recordings revealed that the cultured afadin-deficient neurons showed impaired presynaptic functions. These results indicate that afadin regulates both PAJ formation and presynaptic differentiation in most mossy fiber-CA3 pyramidal cell synapses, while in a considerable population of these neurons, afadin regulates only PAJ formation but not presynaptic differentiation. PMID:24587018

  18. Treatment with AICAR inhibits blastocyst development, trophectoderm differentiation and tight junction formation and function in mice.

    Science.gov (United States)

    Calder, Michele D; Edwards, Nicole A; Betts, Dean H; Watson, Andrew J

    2017-09-13

    What is the impact of adenosine monophosphate-activated protein kinase (AMPK) activation on blastocyst formation, gene expression, and tight junction formation and function? AMPK activity must be tightly controlled for normal preimplantation development and blastocyst formation to occur. AMPK isoforms are detectable in oocytes, cumulus cells and preimplantation embryos. Cultured embryos are subject to many stresses that can activate AMPK. Two primary experiments were carried out to determine the effect of AICAR treatment on embryo development and maintenance of the blastocoel cavity. Embryos were recovered from superovulated mice. First, 2-cell embryos were treated with a concentration series (0-2000 μM) of AICAR for 48 h until blastocyst formation would normally occur. In the second experiment, expanded mouse blastocysts were treated for 9 h with 1000 μM AICAR. Outcomes measured included development to the blastocyst stage, cell number, blastocyst volume, AMPK phosphorylation, Cdx2 and blastocyst formation gene family expression (mRNAs and protein measured using quantitative RT-PCR, immunoblotting, immunofluorescence), tight junction function (FITC dextran dye uptake assay), and blastocyst ATP levels. The reversibility of AICAR treatment was assessed using Compound C (CC), a well-known inhibitor of AMPK, alone or in combination with AICAR. Prolonged treatment with AICAR from the 2-cell stage onward decreases blastocyst formation, reduces total cell number, embryo diameter, leads to loss of trophectoderm cell contacts and membrane zona occludens-1 staining, and increased nuclear condensation. Treatment with CC alone inhibited blastocyst development only at concentrations that are higher than normally used. AICAR treated embryos displayed altered mRNA and protein levels of blastocyst formation genes. Treatment of blastocysts with AICAR for 9 h induced blastocyst collapse, altered blastocyst formation gene expression, increased tight junction permeability and

  19. The role of Rap1 in cell-cell junction formation

    NARCIS (Netherlands)

    Kooistra, M.R.H.

    2008-01-01

    Both epithelial and endothelial cells form cell-cell junctions at the cell-cell contacts to maintain tissue integrity. Proper regulation of cell-cell junctions is required for the organisation of the tissue and to prevent leakage of blood vessels. In endothelial cells, the cell-cell junctions are

  20. Phase diagrams of the Katz-Lebowitz-Spohn process on lattices with a junction

    Science.gov (United States)

    Tian, Bo; Jiang, Rui; Ding, Zhong-Jun; Hu, Mao-Bin; Wu, Qing-Song

    2013-06-01

    This paper studies the Katz-Lebowitz-Spohn (KLS) process on lattices with a junction, where particles move on parallel lattice branches that combine into a single lattice at the junction. It is shown that 11 kinds of phase diagrams could be observed, depending on the two parameters ɛ and δ in the KLS process. We have investigated the phase diagrams as well as bulk density analytically based on flow rate conservation and the extremal current principle. Extensive Monte Carlo computer simulations are performed, and it is found that they are in excellent agreement with theoretical prediction.

  1. Phase diagrams of the Katz-Lebowitz-Spohn process on lattices with a junction.

    Science.gov (United States)

    Tian, Bo; Jiang, Rui; Ding, Zhong-Jun; Hu, Mao-Bin; Wu, Qing-Song

    2013-06-01

    This paper studies the Katz-Lebowitz-Spohn (KLS) process on lattices with a junction, where particles move on parallel lattice branches that combine into a single lattice at the junction. It is shown that 11 kinds of phase diagrams could be observed, depending on the two parameters ε and δ in the KLS process. We have investigated the phase diagrams as well as bulk density analytically based on flow rate conservation and the extremal current principle. Extensive Monte Carlo computer simulations are performed, and it is found that they are in excellent agreement with theoretical prediction.

  2. A Lattice Boltzmann study of the effects of viscoelasticity on droplet formation in microfluidic cross-junctions

    CERN Document Server

    Gupta, Anupam

    2015-01-01

    Based on mesoscale lattice Boltzmann (LB) numerical simulations, we investigate the effects of viscoelasticity on the break-up of liquid threads in microfluidic cross-junctions, where droplets are formed by focusing a liquid thread of a dispersed (d) phase into another co-flowing continuous (c) immiscible phase. Working at small Capillary numbers, we investigate the effects of non-Newtonian phases in the transition from droplet formation at the cross-junction (DCJ) to droplet formation downstream of the cross-junction (DC) (Liu $\\&$ Zhang, ${\\it Phys. ~Fluids.}$ ${\\bf 23}$, 082101 (2011)). We will analyze cases with ${\\it Droplet ~Viscoelasticity}$ (DV), where viscoelastic properties are confined in the dispersed phase, as well as cases with ${\\it Matrix ~Viscoelasticity}$ (MV), where viscoelastic properties are confined in the continuous phase. Moderate flow-rate ratios $Q \\approx {\\cal O}(1)$ of the two phases are considered in the present study. Overall, we find that the effects are more pronounced in ...

  3. Gap Junction in the Teleost Fish Lineage: Duplicated Connexins May Contribute to Skin Pattern Formation and Body Shape Determination.

    Science.gov (United States)

    Watanabe, Masakatsu

    2017-01-01

    Gap junctions are intercellular channels that allow passage of ions and small molecules between adjacent cells. Gap junctions in vertebrates are composed of connexons, which are an assembly of six proteins, connexins. Docking of two connexons on the opposite cell surfaces forms a gap junction between the cytoplasm of two neighboring cells. Connexins compose a family of structurally related four-pass transmembrane proteins. In mammals, there are ~20 connexins, each of which contributes to unique permeability of gap junctions, and mutations of some connexin-encoding genes are associated with human diseases. Zebrafish has been predicted to contain 39 connexin-encoding genes; the high number can be attributed to gene duplication during fish evolution, which resulted in diversified functions of gap junctions in teleosts. The determination of body shapes and skin patterns in animal species is an intriguing question. Mathematical models suggest principle mechanisms explaining the diversification of animal morphology. Recent studies have revealed the involvement of gap junctions in fish morphological diversity, including skin pattern formation and body shape determination. This review focuses on connexins in teleosts, which are integrated in the mathematical models explaining morphological diversity of animal skin patterns and body shapes.

  4. Role of Two Cell Wall Amidases in Septal Junction and Nanopore Formation in the Multicellular Cyanobacterium Anabaena sp. PCC 7120

    Directory of Open Access Journals (Sweden)

    Jan Bornikoel

    2017-09-01

    Full Text Available Filamentous cyanobacteria have developed a strategy to perform incompatible processes in one filament by differentiating specialized cell types, N2-fixing heterocysts and CO2-fixing, photosynthetic, vegetative cells. These bacteria can be considered true multicellular organisms with cells exchanging metabolites and signaling molecules via septal junctions, involving the SepJ and FraCD proteins. Previously, it was shown that the cell wall lytic N-acetylmuramyl-L-alanine amidase, AmiC2, is essential for cell–cell communication in Nostoc punctiforme. This enzyme perforates the septal peptidoglycan creating an array of nanopores, which may be the framework for septal junction complexes. In Anabaena sp. PCC 7120, two homologs of AmiC2, encoded by amiC1 and amiC2, were identified and investigated in two different studies. Here, we compare the function of both AmiC proteins by characterizing different Anabaena amiC mutants, which was not possible in N. punctiforme, because there the amiC1 gene could not be inactivated. This study shows the different impact of each protein on nanopore array formation, the process of cell–cell communication, septal protein localization, and heterocyst differentiation. Inactivation of either amidase resulted in significant reduction in nanopore count and in the rate of fluorescent tracer exchange between neighboring cells measured by FRAP analysis. In an amiC1 amiC2 double mutant, filament morphology was affected and heterocyst differentiation was abolished. Furthermore, the inactivation of amiC1 influenced SepJ localization and prevented the filament-fragmentation phenotype that is characteristic of sepJ or fraC fraD mutants. Our findings suggest that both amidases are to some extent redundant in their function, and describe a functional relationship of AmiC1 and septal proteins SepJ and FraCD.

  5. Double-side fabrication process and millimeter wave response of intrinsic Josephson junctions

    Institute of Scientific and Technical Information of China (English)

    WU JingBo; YI DongChao; GU ZhengHao; KANG Lin; XU WeiWei; CHEN Jian; WU PeiHeng

    2009-01-01

    We adopted double-side fabrication process to prepare intrinsic Josephson junctions (IJJs) based on Bi2Sr2CaCu2O8-x(BSCCO) single crystals. Using crystal cleavage and double-side argon ion milling, we have successfully fabricated very uniform IJJs with the thickness of single crystal slice less than 200 nm. Using quasi-optical system, the response of the IJJs to millimeter wave radiation was studied. With applied magnetic field perpendicular to a-b plane, we have observed Shapiro steps under millimeter wave radiation, and the Josephson oscillation of each junction was phase-locking.

  6. Soft versus hard junction formation for α-terthiophene molecular wires and their charge transfer complexes

    Science.gov (United States)

    Vezzoli, Andrea; Grace, Iain M.; Brooke, Carly; Nichols, Richard J.; Lambert, Colin J.; Higgins, Simon J.

    2017-03-01

    We used a range of scanning tunnelling microscopy (STM)-based methods to conduct a detailed study of single molecule junction conductance enhancement upon charge transfer complex formation, using bis(thiaalkyl)arene molecular wires as electron donors and tetracyanoethylene (TCNE) as an electron acceptor. Using the "hard" STM break junction (STM-BJ) method, in which a Au STM tip is pushed into a Au substrate and then withdrawn in the presence of molecules, we see a single, very broad, peak in the resulting conductance histogram when all data are used; the conductance enhancement is 25-fold for a terthiophene donor and 15-fold for a phenyl group. After rational data selection, in which only current-distance curves that contain a current plateau >0.2 nm long are used in the conductance histogram, three sharper peaks are resolved in the histograms for the charge transfer complexes; two substantially lower-conductance peaks are resolved for the uncomplexed molecules. Using the "soft" STM I(s) technique, in which initial contact between tip and substrate is avoided and the current limit is about an order of magnitude lower, we were able to resolve two peaks for the uncomplexed molecules depending upon the initial set point current (i.e., tip height), one at the same value as the lower of the two data-selected STM-BJ histogram peaks and an additional peak beyond the low-current limit for the STM-BJ experiment. For the terthiophene, the low, medium, and high conductance peaks for the TCNE complex are, respectively, ca. 70, 70, and 46 times higher in conductance than the corresponding peaks for the free molecule.

  7. ROCK activity regulates functional tight junction assembly during blastocyst formation in porcine parthenogenetic embryos

    Directory of Open Access Journals (Sweden)

    Jeongwoo Kwon

    2016-04-01

    Full Text Available The Rho-associated coiled-coil-containing protein serine/threonine kinases 1 and 2 (ROCK1 and ROCK2 are Rho subfamily GTPase downstream effectors that regulate cell migration, intercellular adhesion, cell polarity, and cell proliferation by stimulating actin cytoskeleton reorganization. Inhibition of ROCK proteins affects specification of the trophectoderm (TE and inner cell mass (ICM lineages, compaction, and blastocyst cavitation. However, the molecules involved in blastocyst formation are not known. Here, we examined developmental competence and levels of adherens/tight junction (AJ/TJ constituent proteins, such as CXADR, OCLN, TJP1, and CDH1, as well as expression of their respective mRNAs, after treating porcine parthenogenetic four-cell embryos with Y-27632, a specific inhibitor of ROCK, at concentrations of 0, 10, 20, 100 µM for 24 h. Following this treatment, the blastocyst development rates were 39.1, 20.7, 10.0, and 0% respectively. In embryos treated with 20 µM treatment, expression levels of CXADR, OCLN, TJP1, and CDH1 mRNA and protein molecules were significantly reduced (P < 0.05. FITC-dextran uptake assay revealed that the treatment caused an increase in TE TJ permeability. Interestingly, the majority of the four-cell and morula embryos treated with 20 µM Y-27643 for 24 h showed defective compaction and cavitation. Taken together, our results indicate that ROCK activity may differentially affect assembly of AJ/TJs as well as regulate expression of genes encoding junctional proteins.

  8. High density processing electronics for superconducting tunnel junction x-ray detector arrays

    Energy Technology Data Exchange (ETDEWEB)

    Warburton, W.K., E-mail: bill@xia.com [XIA LLC, 31057 Genstar Road, Hayward, CA 94544 (United States); Harris, J.T. [XIA LLC, 31057 Genstar Road, Hayward, CA 94544 (United States); Friedrich, S. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2015-06-01

    Superconducting tunnel junctions (STJs) are excellent soft x-ray (100–2000 eV) detectors, particularly for synchrotron applications, because of their ability to obtain energy resolutions below 10 eV at count rates approaching 10 kcps. In order to achieve useful solid detection angles with these very small detectors, they are typically deployed in large arrays – currently with 100+ elements, but with 1000 elements being contemplated. In this paper we review a 5-year effort to develop compact, computer controlled low-noise processing electronics for STJ detector arrays, focusing on the major issues encountered and our solutions to them. Of particular interest are our preamplifier design, which can set the STJ operating points under computer control and achieve 2.7 eV energy resolution; our low noise power supply, which produces only 2 nV/√Hz noise at the preamplifier's critical cascode node; our digital processing card that digitizes and digitally processes 32 channels; and an STJ I–V curve scanning algorithm that computes noise as a function of offset voltage, allowing an optimum operating point to be easily selected. With 32 preamplifiers laid out on a custom 3U EuroCard, and the 32 channel digital card in a 3U PXI card format, electronics for a 128 channel array occupy only two small chassis, each the size of a National Instruments 5-slot PXI crate, and allow full array control with simple extensions of existing beam line data collection packages.

  9. Vitamin D3 regulates the formation and degradation of gap junctions in androgen-responsive human prostate cancer cells.

    Directory of Open Access Journals (Sweden)

    Linda Kelsey

    Full Text Available 1α-25(OH2 vitamin D3 (1-25D, an active hormonal form of Vitamin D3, is a well-known chemopreventive and pro-differentiating agent. It has been shown to inhibit the growth of several prostate cancer cell lines. Gap junctions, formed of proteins called connexins (Cx, are ensembles of cell-cell channels, which permit the exchange of small growth regulatory molecules between adjoining cells. Cell-cell communication mediated by gap junctional channels is an important homeostatic control mechanism for regulating cell growth and differentiation. We have investigated the effect of 1-25D on the formation and degradation of gap junctions in an androgen-responsive prostate cancer cell line, LNCaP, which expresses retrovirally-introduced Cx32. Connexin32 is expressed by the luminal and well-differentiated cells of normal prostate and prostate tumors. Our results document that 1-25D enhances the expression of Cx32 and its subsequent assembly into gap junctions. Our results further show that 1-25D prevents androgen-regulated degradation of Cx32, post-translationally, independent of androgen receptor (AR-mediated signaling. Finally, our findings document that formation of gap junctions sensitizes Cx32-expressing LNCaP cells to the growth inhibitory effects of 1-25D and alters their morphology. These findings suggest that the growth-inhibitory effects of 1-25D in LNCaP cells may be related to its ability to modulate the assembly of Cx32 into gap junctions.

  10. Eya1 protein phosphatase regulates tight junction formation in lung distal epithelium.

    Science.gov (United States)

    El-Hashash, Ahmed H K; Turcatel, Gianluca; Varma, Saaket; Berika, Mohamed; Al Alam, Denise; Warburton, David

    2012-09-01

    Little is known about the regulatory mechanisms underlying lung epithelial tight junction (TJ) assembly, which is inextricably linked to the preservation of epithelial polarity, and is highly coordinated by proteins that regulate epithelial cell polarity, such as aPKCζ. We recently reported that Eya1 phosphatase functions through aPKCζ-Notch1 signaling to control cell polarity in the lung epithelium. Here, we have extended these observations to TJ formation to demonstrate that Eya1 is crucial for the maintenance of TJ protein assembly in the lung epithelium, probably by controlling aPKCζ phosphorylation levels, aPKCζ-mediated TJ protein phosphorylation and Notch1-Cdc42 activity. Thus, TJs are disassembled after interfering with Eya1 function in vivo or during calcium-induced TJ assembly in vitro. These effects are reversed by reintroduction of wild-type Eya1 or partially inhibiting aPKCζ in Eya1siRNA cells. Moreover, genetic activation of Notch1 rescues Eya1(-/-) lung epithelial TJ defects. These findings uncover novel functions for the Eya1-aPKCζ-Notch1-Cdc42 pathway as a crucial regulatory mechanism of TJ assembly and polarity of the lung epithelium, providing a conceptual framework for future mechanistic and translational studies in this area.

  11. Dynamic formation of microenvironments at the myotendinous junction correlates with muscle fiber morphogenesis in zebrafish.

    Science.gov (United States)

    Snow, Chelsi J; Henry, Clarissa A

    2009-01-01

    Muscle development involves the specification and morphogenesis of muscle fibers that attach to tendons. After attachment, muscles and tendons then function as an integrated unit to transduce force to the skeletal system and stabilize joints. The attachment site is the myotendinous junction, or MTJ, and is the primary site of force transmission. We find that attachment of fast-twitch myofibers to the MTJ correlates with the formation of novel microenvironments within the MTJ. The expression or activation of two proteins involved in anchoring the intracellular cytoskeleton to the extracellular matrix, Focal adhesion kinase (Fak) and beta-dystroglycan is up-regulated. Conversely, the extracellular matrix protein Fibronectin (Fn) is down-regulated. This degradation of Fn as fast-twitch fibers attach to the MTJ results in Fn protein defining a novel microenvironment within the MTJ adjacent to slow-twitch, but not fast-twitch, muscle. Interestingly, however, Fak, laminin, Fn and beta-dystroglycan concentrate at the MTJ in mutants that do not have slow-twitch fibers. Taken together, these data elucidate novel and dynamic microenvironments within the MTJ and indicate that MTJ morphogenesis is spatially and temporally complex.

  12. Functional consequences of heterogeneous gap junction channel formation and its influence in health and disease.

    Science.gov (United States)

    Cottrell, G Trevor; Burt, Janis M

    2005-06-10

    The capacity of multiple connexins to hetero-oligomerize into functional heterogeneous gap junction channels has been demonstrated in vivo, in vitro, and in nonmammalian expression systems. These heterogeneous channels display gating activity, channel conductances, selectivity and regulatory behaviors that are sometimes not predicted by the behaviors of the corresponding homogeneous channels. Such observations suggest that heteromerization of gap junction proteins offers an efficient cellular strategy for finely regulating cell-to-cell communication. The available evidence strongly indicates that heterogeneous gap junction assembly is important to normal growth and differentiation, and may influence the appearance of several disease states. Definitive evidence that heterogeneous gap junction channels differentially regulate electrical conduction in excitable cells is absent. This review examines the prevalence, regulation, and implications of gap junction channel hetero-oligomerization.

  13. aPKC phosphorylates JAM-A at Ser285 to promote cell contact maturation and tight junction formation.

    Science.gov (United States)

    Iden, Sandra; Misselwitz, Steve; Peddibhotla, Swetha S D; Tuncay, Hüseyin; Rehder, Daniela; Gerke, Volker; Robenek, Horst; Suzuki, Atsushi; Ebnet, Klaus

    2012-03-05

    The PAR-3-atypical protein kinase C (aPKC)-PAR-6 complex has been implicated in the development of apicobasal polarity and the formation of tight junctions (TJs) in vertebrate epithelial cells. It is recruited by junctional adhesion molecule A (JAM-A) to primordial junctions where aPKC is activated by Rho family small guanosine triphosphatases. In this paper, we show that aPKC can interact directly with JAM-A in a PAR-3-independent manner. Upon recruitment to primordial junctions, aPKC phosphorylates JAM-A at S285 to promote the maturation of immature cell-cell contacts. In fully polarized cells, S285-phosphorylated JAM-A is localized exclusively at the TJs, and S285 phosphorylation of JAM-A is required for the development of a functional epithelial barrier. Protein phosphatase 2A dephosphorylates JAM-A at S285, suggesting that it antagonizes the activity of aPKC. Expression of nonphosphorylatable JAM-A/S285A interferes with single lumen specification during cyst development in three-dimensional culture. Our data suggest that aPKC phosphorylates JAM-A at S285 to regulate cell-cell contact maturation, TJ formation, and single lumen specification.

  14. Tunnel Field-Effect Transistor with Epitaxially Grown Tunnel Junction Fabricated by Source/Drain-First and Tunnel-Junction-Last Processes

    Science.gov (United States)

    Morita, Yukinori; Mori, Takahiro; Migita, Shinji; Mizubayashi, Wataru; Tanabe, Akihito; Fukuda, Koichi; Masahara, Meishoku; Ota, Hiroyuki

    2013-04-01

    We fabricate p- and n-channel Si tunnel field-effect transistors (TFETs) with an epitaxially grown tunnel junction. In a novel source/drain-first and tunnel-junction-last fabrication process, a thin epitaxial undoped Si channel (epichannel) is deposited on a preferentially fabricated p- or n-type source area. The epichannel sandwiched by a gate insulator and a highly doped source well acts as a parallel-plate tunnel capacitor, which effectively multiplies drain current with an enlarged tunnel area. On the basis of its simple structure and easy fabrication, symmetric n- and p-transistor and complementary metal oxide semiconductor inverter operations were successfully demonstrated.

  15. Final audit report of remedial action construction at the UMTRA Project, Grand Junction, Colorado, processing site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    This final audit report (FAR) for remedial action at the Grand Junction, Colorado, Uranium Mill Tailings Remedial Action (UMTRA) Project processing site consists of a summary of the radiological surveillances/ audits, the quality assurance (QA) in-process surveillances, and the QA final close-out inspection performed by the US Department of Energy (DOE) and Technical Assistance Contractor (TAC). The FAR also summarizes other surveillances performed by the US Nuclear Regulatory Commission (NRC). To summarize, a total of one finding and 127 observations were noted during DOE/TAC audit and surveillance activities. The NRC noted general site-related observations during the OSCRs. Follow-up to responses required from MK-Ferguson for the DOE/TAC finding and observations indicated that all issues related to the Grand Junction processing site were resolved and closed out to the DOE`s satisfaction. The NRC OSCRs resulted in no issues related to the Grand Junction processing site requiring a response from MK-Ferguson.

  16. Arc/Forearc Lengthening at Plate Triple Junctions and the Formation of Ophiolitic Soles

    Science.gov (United States)

    Casey, John; Dewey, John

    2013-04-01

    The principal enigma of large obducted ophiolite slabs is that they clearly must have been generated by some form of organized sea-floor spreading/plate-accretion, such as may be envisioned for the oceanic ridges, yet the volcanics commonly have arc affinity (Miyashiro) with boninites (high-temperature/low-pressure, high Mg and Si andesites), which are suggestive of a forearc origin. PT conditions under which boninites and metamorphic soles form and observations of modern forearc systems lead us to the conclusion that ophiolite formation is associated with overidding plate spreading centers that intersect the trench to form ridge-trench-trench of ridge-trench-tranform triple junctions. The spreading centers extend and lengthen the forearc parallel to the trench and by definition are in supra-subduction zone (SSZ) settings. Many ophiolites likewise have complexly-deformed associated mafic-ultramafic assemblages that suggest fracture zone/transform t along their frontal edges, which in turn has led to models involving the nucleation of subduction zones on fracture zones or transpressional transforms. Hitherto, arc-related sea-floor-spreading has been considered to be either pre-arc (fore-arc boninites) or post-arc (classic Karig-style back arc basins that trench-parallell split arcs). Syn-arc boninites and forearc oceanic spreading centers that involve a stable ridge/trench/trench triple or a ridge-trench-transform triple junction, the ridge being between the two upper plates, are consistent with large slab ophiolite formation in a readied obduction settting. The direction of subduction must be oblique with a different sense in the two subduction zones and the oblique subduction cannot be partitioned into trench orthogonal and parallel strike-slip components. As the ridge spreads, new oceanic lithosphere is created within the forearc, the arc and fore-arc lengthen significantly, and a syn-arc ophiolite forearc complex is generated by this mechanism. The ophiolite

  17. A fast formation process for lithium batteries

    Science.gov (United States)

    Lee, Hsiang-Hwan; Wang, Yung-Yun; Wan, Chi-Chao; Yang, Mo-Hua; Wu, Hung-Chun; Shieh, Deng-Tswen

    The formation process presently used in the manufacture of lithium-ion batteries includes the solid electrolyte interface (SEI) growth process and another process for lithium intercalation into carbon. The latter process is both time and energy consuming. This study proposes a new concepts that can shorten the formation time by narrowing the potential range and bypassing the intercalation step during formation. The optimum cut-off voltage is 3.7 V for industrial LiCoO 2|C cells, and the formation time is reduced to less than one half of that required in the conventional formation procedure. Cycle performance is not affected significantly because the desired SEI growth is mainly completed in the potential range. These results suggest that the new method is superior to conventional formation.

  18. Effect of unequal injection rates on asymmetric exclusion processes with junction

    Institute of Scientific and Technical Information of China (English)

    Xiao Song; Liu Ming-Zhe; Wang Jian-Jun; Wang Hua

    2011-01-01

    In this paper, we investigate the effect of unequal injection rates on totally asymmetric simple exclusion processes (TASEPs) with a 2-input 1-output junction and parallel update. A mean-field approach is developed to deal with the junction that connects two sub-chains and the single main chain. We obtain the stationary particle currents, density profiles and phase diagrams. Interestingly, we find that the number of stationary-state phases is changeable depending on the value of α1 (α1 is the injection rate on the first sub-chain). When α1 > 1/3, there are seven stationary-state phases in the system, however when α1 < 1/3, only six stationary-state phases exist in the system. The theoretical calculations are shown to be in agreement with Monte Carlo simulations.

  19. Formation of Schottky-type metal/SrTiO{sub 3} junctions and their resistive properties

    Energy Technology Data Exchange (ETDEWEB)

    Stoecker, Hartmut; Zschornak, Matthias [Technische Universitaet Dresden, Institut fuer Strukturphysik, Dresden (Germany); TU Bergakademie Freiberg, Institut fuer Experimentelle Physik, Freiberg (Germany); Seibt, Juliane; Hanzig, Florian; Wintz, Susi; Abendroth, Barbara; Meyer, Dirk C. [TU Bergakademie Freiberg, Institut fuer Experimentelle Physik, Freiberg (Germany); Kortus, Jens [TU Bergakademie Freiberg, Institut fuer Theoretische Physik, Freiberg (Germany)

    2010-08-15

    Motivated by the successful use of strontium titanate with different doping metals for memory cells on the basis of resistive switching and the recent findings on the major importance of oxygen vacancy redistribution in this compound, the present work shows the possibility of a non-volatile resistance change memory based on vacancy-doped SrTiO{sub 3}. The formation of corresponding metal/SrTiO{sub 3-{delta}} junctions ({delta}>0) in an electric field will be discussed as well as the switching between ohmic and Schottky-type contact behavior. A notable hysteresis in the current-voltage characteristics is used to carry out Write, Read, and Erase operations exemplifying the memory cell properties of such junctions. But whereas the electric field-induced formation of Schottky-type junctions is explainable by oxygen vacancy redistribution, the resistive switching needs to be discussed in terms of vacancies serving as electron trap states at the metal/oxide interface. (orig.)

  20. Development and process control of magnetic tunnel junctions for magnetic random access memory devices

    Science.gov (United States)

    Kula, Witold; Wolfman, Jerome; Ounadjela, Kamel; Chen, Eugene; Koutny, William

    2003-05-01

    We report on the development and process control of magnetic tunnel junctions (MTJs) for magnetic random access memory (MRAM) devices. It is demonstrated that MTJs with high magnetoresistance ˜40% at 300 mV, resistance-area product (RA) ˜1-3 kΩ μm2, low intrinsic interlayer coupling (Hin) ˜2-3 Oe, and excellent bit switching characteristics can be developed and fully integrated with complementary metal-oxide-semiconductor circuitry into MRAM devices. MTJ uniformity and repeatability level suitable for mass production has been demonstrated with the advanced processing and monitoring techniques.

  1. A self-aligned nano-fabrication process for vertical NbN-MgO-NbN Josephson junctions

    Science.gov (United States)

    Grimm, A.; Jebari, S.; Hazra, D.; Blanchet, F.; Gustavo, F.; Thomassin, J.-L.; Hofheinz, M.

    2017-10-01

    We present a new process for fabricating vertical NbN-MgO-NbN Josephson junctions using self-aligned silicon nitride spacers. It allows for a wide range of junction areas from 0.02 to several 100 μm2. At the same time, it is suited for the implementation of complex microwave circuits with transmission line impedances ranging from 1 {{k}}{{Ω }}. The constituent thin films and the finished junctions are characterized. The latter are shown to have high gap voltages (> 4 {mV}) and low sub-gap leakage currents.

  2. Laser Annealing of Self-Aligned As+ Implants in Contact Windows for Ultrashallow Junction Formation

    NARCIS (Netherlands)

    Biasotto, C.; Gonda, V.; Nanver, L.K.; Van der Cingel, J.; Jovanovic, V.

    2009-01-01

    In the past it has been shown that ultrashallow junctions with minimum lateral dimensions can be made by implanting self-aligned to the contact window and using one-shot excimer laser annealing (ELA) to activate the dopants. Besides the recrystallization of the implanted Si, the final structuring at

  3. Zurek-Kibble domain structures: The dynamics of spontaneous vortex formation in annular Josephson tunnel junctions

    DEFF Research Database (Denmark)

    Monaco, R.; Mygind, Jesper; Rivers, R.J.

    2002-01-01

    Phase transitions create a domain structure with defects, which has been argued by Zurek and Kibble (ZK) to depend in a characteristic way on the quench rate. We present an experiment to measure the ZK scaling exponent sigma. Using long symmetric Josephson tunnel junctions, for which the predicted...

  4. Gap Junctions

    Science.gov (United States)

    Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L.; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

    2013-01-01

    Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1981-2035, 2012. PMID:23723031

  5. Gap junctions.

    Science.gov (United States)

    Nielsen, Morten Schak; Axelsen, Lene Nygaard; Sorgen, Paul L; Verma, Vandana; Delmar, Mario; Holstein-Rathlou, Niels-Henrik

    2012-07-01

    Gap junctions are essential to the function of multicellular animals, which require a high degree of coordination between cells. In vertebrates, gap junctions comprise connexins and currently 21 connexins are known in humans. The functions of gap junctions are highly diverse and include exchange of metabolites and electrical signals between cells, as well as functions, which are apparently unrelated to intercellular communication. Given the diversity of gap junction physiology, regulation of gap junction activity is complex. The structure of the various connexins is known to some extent; and structural rearrangements and intramolecular interactions are important for regulation of channel function. Intercellular coupling is further regulated by the number and activity of channels present in gap junctional plaques. The number of connexins in cell-cell channels is regulated by controlling transcription, translation, trafficking, and degradation; and all of these processes are under strict control. Once in the membrane, channel activity is determined by the conductive properties of the connexin involved, which can be regulated by voltage and chemical gating, as well as a large number of posttranslational modifications. The aim of the present article is to review our current knowledge on the structure, regulation, function, and pharmacology of gap junctions. This will be supported by examples of how different connexins and their regulation act in concert to achieve appropriate physiological control, and how disturbances of connexin function can lead to disease. © 2012 American Physiological Society. Compr Physiol 2:1853-1872, 2012.

  6. Dissipative processes in superconducting nanodevices: Nanowire-resonators, shunted nanowires, and graphene proximity junctions

    Science.gov (United States)

    Brenner, Matthew W.

    The topic of superconducting nanowires has recently been an interesting field of research which has included the study of the superconductor to insulator transition (SIT), the observation of macroscopic quantum behavior such as quantum phase slips (QPS), and the potential use of nanowires as qubits. Superconducting coplanar microwave waveguide resonators have also become a popular way of studying superconducting junctions and qubits, as they provide an extremely low noise environment. For example, superconducting two-dimensional Fabry-Perot resonators have been used by other groups to make non-demolition measurements of a qubit. The motivation of this thesis will be the merging of the fields of superconducting nanowires and the technique of using superconducting microwave resonators to study junctions by incorporating a nanowire into the resonator itself at a current anti-node. By doing this, the nonlinear effects of the nanowire can be studied which may find application in single photon detectors, mixers, and the readout of qubits. We also employ the technique of molecular templating to fabricate some of the thinnest superconducting nanowires ever studied (down to ˜ 5 nm in diameter in some cases). In this thesis, we extend the understanding of the nonlinear properties of a nanowire-resonator system and investigate a new type of nonlinearity that involves a pulsing regime between the superconducting and normal phases of the nanowire. We develop a model, which describes the results quantitatively and by modeling the system, we are able to extract information regarding the relaxation time of the nanowire back into the superconducting state. We also study double nanowire-resonator systems where two closely spaced parallel nanowires interrupt the resonator center conductor and form a loop where vortex tunneling processes can occur. Using a double nanowire-resonator we are able to observe the Little-Parks effect at low temperatures (where the resistance of the wires

  7. Anodization-based process for the fabrication of all niobium nitride Josephson junction structures

    Directory of Open Access Journals (Sweden)

    Massimiliano Lucci

    2017-03-01

    Full Text Available We studied the growth and oxidation of niobium nitride (NbN films that we used to fabricate superconductive tunnel junctions. The thin films were deposited by dc reactive magnetron sputtering using a mixture of argon and nitrogen. The process parameters were optimized by monitoring the plasma with an optical spectroscopy technique. This technique allowed us to obtain NbN as well as good quality AlN films and both were used to obtain NbN/AlN/NbN trilayers. Lift-off lithography and selective anodization of the NbN films were used, respectively, to define the main trilayer geometry and/or to separate electrically, different areas of the trilayers. The anodized films were characterized by using Auger spectroscopy to analyze compounds formed on the surface and by means of a nano-indenter in order to investigate its mechanical and adhesion properties. The transport properties of NbN/AlN/NbN Josephson junctions obtained as a result of the above described fabrication process were measured in liquid helium at 4.2 K.

  8. Fabrication of nano-sized magnetic tunnel junctions using lift-off process assisted by atomic force probe tip.

    Science.gov (United States)

    Jung, Ku Youl; Min, Byoung-Chul; Ahn, Chiyui; Choi, Gyung-Min; Shin, Il-Jae; Park, Seung-Young; Rhie, Kungwon; Shin, Kyung-Ho

    2013-09-01

    We present a fabrication method for nano-scale magnetic tunnel junctions (MTJs), employing e-beam lithography and lift-off process assisted by the probe tip of atomic force microscope (AFM). It is challenging to fabricate nano-sized MTJs on small substrates because it is difficult to use chemical mechanical planarization (CMP) process. The AFM-assisted lift-off process enables us to fabricate nano-sized MTJs on small substrates (12.5 mm x 12.5 mm) without CMP process. The e-beam patterning has been done using bi-layer resist, the poly methyl methacrylate (PMMA)/ hydrogen silsesquioxane (HSQ). The PMMA/HSQ resist patterns are used for both the etch mask for ion milling and the self-aligned mask for top contact formation after passivation. The self-aligned mask buried inside a passivation oxide layer, is readily lifted-off by the force exerted by the probe tip. The nano-MTJs (160 nm x 90 nm) fabricated by this method show clear current-induced magnetization switching with a reasonable TMR and critical switching current density.

  9. Junction formation of Cu3BiS3 investigated by Kelvin probe force microscopy and surface photovoltage measurements

    Science.gov (United States)

    Mesa, Fredy; Chamorro, William; Vallejo, William; Baier, Robert; Dittrich, Thomas; Grimm, Alexander; Lux-Steiner, Martha C

    2012-01-01

    Summary Recently, the compound semiconductor Cu3BiS3 has been demonstrated to have a band gap of ~1.4 eV, well suited for photovoltaic energy harvesting. The preparation of polycrystalline thin films was successfully realized and now the junction formation to the n-type window needs to be developed. We present an investigation of the Cu3BiS3 absorber layer and the junction formation with CdS, ZnS and In2S3 buffer layers. Kelvin probe force microscopy shows the granular structure of the buffer layers with small grains of 20–100 nm, and a considerably smaller work-function distribution for In2S3 compared to that of CdS and ZnS. For In2S3 and CdS buffer layers the KPFM experiments indicate negatively charged Cu3BiS3 grain boundaries resulting from the deposition of the buffer layer. Macroscopic measurements of the surface photovoltage at variable excitation wavelength indicate the influence of defect states below the band gap on charge separation and a surface-defect passivation by the In2S3 buffer layer. Our findings indicate that Cu3BiS3 may become an interesting absorber material for thin-film solar cells; however, for photovoltaic application the band bending at the charge-selective contact has to be increased. PMID:22497001

  10. Junction formation of Cu3BiS3 investigated by Kelvin probe force microscopy and surface photovoltage measurements

    Directory of Open Access Journals (Sweden)

    Fredy Mesa

    2012-03-01

    Full Text Available Recently, the compound semiconductor Cu3BiS3 has been demonstrated to have a band gap of ~1.4 eV, well suited for photovoltaic energy harvesting. The preparation of polycrystalline thin films was successfully realized and now the junction formation to the n-type window needs to be developed. We present an investigation of the Cu3BiS3 absorber layer and the junction formation with CdS, ZnS and In2S3 buffer layers. Kelvin probe force microscopy shows the granular structure of the buffer layers with small grains of 20–100 nm, and a considerably smaller work-function distribution for In2S3 compared to that of CdS and ZnS. For In2S3 and CdS buffer layers the KPFM experiments indicate negatively charged Cu3BiS3 grain boundaries resulting from the deposition of the buffer layer. Macroscopic measurements of the surface photovoltage at variable excitation wavelength indicate the influence of defect states below the band gap on charge separation and a surface-defect passivation by the In2S3 buffer layer. Our findings indicate that Cu3BiS3 may become an interesting absorber material for thin-film solar cells; however, for photovoltaic application the band bending at the charge-selective contact has to be increased.

  11. Abstruse neologism formation: parallel processing revisited.

    Science.gov (United States)

    Christman, S S

    1992-01-01

    Aspects of two different approaches to normal syllable formation (Berg, 1989; Clements, 1988, 1990) are incorporated into a model of abstruse neologism production characterized by redundant coding of sonority at various levels of parallel language processing. Data suggesting that the sonority profiles of abstruse neologisms accord with patterns found in legitimate English words are presented. Discussion explores neologism genesis from two well-known theoretical perspectives, illustrates how each theory of syllable formation might be instantiated within the model, and illustrates the role of sonority in constraining abstruse neologism production at several levels of parallel processing.

  12. Transforming growth factor-alpha abrogates glucocorticoid-stimulated tight junction formation and growth suppression in rat mammary epithelial tumor cells.

    Science.gov (United States)

    Buse, P; Woo, P L; Alexander, D B; Cha, H H; Reza, A; Sirota, N D; Firestone, G L

    1995-03-24

    The glucocorticoid and transforming growth factor-alpha (TGF-alpha) regulation of growth and cell-cell contact was investigated in the Con8 mammary epithelial tumor cell line derived from a 7,12-dimethylbenz(alpha)anthracene-induced rat mammary adenocarcinoma. In Con8 cell monolayers cultured on permeable filter supports, the synthetic glucocorticoid, dexamethasone, coordinately suppressed [3H]thymidine incorporation, stimulated monolayer transepithelial electrical resistance (TER), and decreased the paracellular leakage of [3H]inulin or [14C]mannitol across the monolayer. These processes dose dependently correlated with glucocorticoid receptor occupancy and function. Constitutive production of TGF-alpha in transfected cells or exogenous treatment with TGF-alpha prevented the glucocorticoid growth suppression response and disrupted tight junction formation without affecting glucocorticoid responsiveness. Treatment with hydroxyurea or araC demonstrated that de novo DNA synthesis is not a requirement for the growth factor disruption of tight junctions. Immunofluorescence analysis revealed that the ZO-1 tight junction protein is localized exclusively at the cell periphery in dexamethasone-treated cells and that TGF-alpha caused-ZO-1 to relocalize from the cell periphery back to a cytoplasmic compartment. Taken together, our results demonstrate that glucocorticoids can coordinately regulate growth inhibition and cell-cell contact of mammary tumor cells and that TGF-alpha, can override both effects of glucocorticoids. These results have uncovered a novel functional "cross-talk" between glucocorticoids and TGF-alpha which potentially regulates the proliferation and differentiation of mammary epithelial cells.

  13. Electro-Optical Characteristics of P+n In0.53Ga0.47As Hetero-Junction Photodiodes in Large Format Dense Focal Plane Arrays

    Science.gov (United States)

    DeWames, R.; Littleton, R.; Witte, K.; Wichman, A.; Bellotti, E.; Pellegrino, J.

    2015-08-01

    This paper is concerned with focal plane array (FPA) data and use of analytical and three-dimensional numerical simulation methods to determine the physical effects and processes limiting performance. For shallow homojunction P+n designs the temperature dependence of dark current for T InGaAs interface. In this description the fitting property is the effective conductivity, σ eff( T), in mho cm-1. Variation in the data suggests σ eff (300 K) values of 1.2 × 10-11-4.6 × 10-11 mho cm-1). Substrate removal extends the quantum efficiency (QE) spectral band into the visible region. However, dead-layer effects limit the QE to 10% at a wavelength of 0.5 μm. For starlight-no moon illumination conditions, the signal-to-noise ratio is estimated to be 50 at an operating temperature of 300 K. A major result of the 3D numerical simulation of the device is the prediction of a perimeter G-R current not associated with the properties of the metallurgical interface. Another is the prediction that for a junction positioned in the larger band gap InP cap layer the QE is bias-dependent and that a relatively large reverse bias ≥0.9 V is needed for the QE to saturate to the shallow homojunction value. At this higher bias the dark current is larger than the shallow homojunction value. The 3D numerical model and the analytical model agree in predicting and explaining the measured radiatively limited diffusion current originating at the n-side of the junction. The calculations of the area-dependent G-R current for the condition studied are also in agreement. Unique advantages of the 3D numerical simulation are the ability to mimic real device structures, achieve deeper understanding of the real physical effects associated with the various methods of junction formation, and predict how device designs will function.

  14. Sambamba : Fast processing of NGS alignment formats

    NARCIS (Netherlands)

    Tarasov, Artem; Vilella, Albert J.; Cuppen, Edwin; Nijman, Isaac J.; Prins, Pjotr

    2015-01-01

    Summary: Sambamba is a high-performance robust tool and library for working with SAM, BAM and CRAM sequence alignment files; the most common file formats for aligned next generation sequencing data. Sambamba is a faster alternative to samtools that exploits multi-core processing and dramatically red

  15. Formation of a pn junction on an anisotropically etched GaAs surface using metalorganic chemical vapor deposition

    Science.gov (United States)

    Leon, R. P.; Bailey, S. G.; Mazaris, G. A.; Williams, W. D.

    1986-01-01

    A continuous p-type GaAs epilayer has been deposited on an n-type sawtooth GaAs surface using MOCVD. A wet chemical etching process was used to expose the intersecting (111)Ga and (-1 -1 1)Ga planes with 6-micron periodicity. Charge-collection microscopy was used to verify the presence of the pn junction thus formed and to measure its depth. The ultimate goal of this work is to fabricate a V-groove GaAs cell with improved absorptivity, high short-circuit current, and tolerance to particle radiation.

  16. Self-planarized process for the fabrication of Josephson junction devices

    Energy Technology Data Exchange (ETDEWEB)

    Merker, Michael; Meckbach, Johannes Maximilian; Buehler, Simon; Il' in, Konstantin; Siegel, Michael [Institut fuer Mikro- und Nanoelektronische Systeme (IMS), Karlsruher Institut fuer Technologie (KIT) (Germany)

    2013-07-01

    High performance Josephson junction (JJ) devices require good control of lateral dimensions. Various JJ devices can benefit from sub-μm feature sizes. In our conventional Nb/Al-AlO{sub x}/Nb process, the minimum feature size is however limited by the step height of the layers beneath. In order to overcome this constraint, we refined our process, resulting in almost flat surfaces at intermediate processing steps without the need for time consuming chemical-mechanical polishing (CMP). Sub-μm feature sizes can be achieved using electron beam lithography (EBL). Due to the application of mix and match lithography, (combination of EBL and photolithography), the turn-around time is not increased significantly compared to our conventional process. Transport properties of sub-μm JJs at 4.2 K will be presented. Our JJ process yields excellent quality parameters with sub-μm feature sizes even in the third metal layer, and is therefore very promising for fabricating sub-μm JJs for quantum devices such as SQUIDs or receiver devices.

  17. Junction formation in CuInSe{sub 2}-based thin-film devices

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Wiesner, H.; Asher, S.; Bhattacharya, R.N.; Keane, J.; Contreras, M.A.; Noufi, R. [National Center for Photovoltaics, National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401 (United States)

    1999-03-01

    The nature of the interface between CuInSe{sub 2} (CIS) and the chemical bath deposited CdS layer has been investigated. We show that heat-treating the absorbers in Cd- or Zn-containing solutions in the presence of ammonium hydroxide sets up a chemical reaction which facilitates an extraction of Cu from the lattice and an in-diffusion of Cd. The characteristics of devices made in this manner suggest that the reaction generates a thin, n-doped region in the absorber. It is quite possible that the CdS/CuInSe{sub 2} device is a buried, shallow junction with a CdS window layer, rather than a heterojunction. We have used these ideas to develop methods for fabricating devices without CdS or Cd. A 14.2{percent} efficiency ZnO/CIGS device was obtained through aqueous treatment in Zn solutions. {copyright} {ital 1999 American Institute of Physics.}

  18. Junction Formation in CuInSe{sub 2} Based Thin Film Devices

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, K.; Wiesner, H.; Asher, S.; Bhattacharya, R. N.; Keane, J.; Contreras, M.; Noufi, R.

    1998-11-18

    The nature of the interface between CuInSe{sub 2} (CIS) and the chemical bath deposited CdS layer has been investigated. We show that heat-treating the absorbers in Cd- or Zn-containing solutions in the presence of ammonium hydroxide sets up a chemical reaction which facilitates an extraction of Cu from the lattice and an in-diffusion of Cd. The characteristics of devices made in this manner suggest that the reaction generates a thin, n-doped region in the absorber. It is quite possible that the CdS/CuInSe{sub 2} device is a buried, shallow junction with a CdS window layer, rather than a heterojunction. We have used these ideas to develop methods for fabricating devices without CdS or Cd. A 14.2% efficiency ZnO/CIGS device was obtained through aqueous treatment in Zn solutions.

  19. Bistatic SAR: Signal Processing and Image Formation.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Mus81 cleavage of Holliday junctions: a failsafe for processing meiotic recombination intermediates?

    Science.gov (United States)

    Gaskell, Louise J; Osman, Fekret; Gilbert, Robert J C; Whitby, Matthew C

    2007-04-04

    The Holliday junction (HJ) is a central intermediate of homologous recombination. Its cleavage is critical for the formation of crossover recombinants during meiosis, which in turn helps to establish chiasmata and promote genetic diversity. Enzymes that cleave HJs, called HJ resolvases, have been identified in all domains of life except eukaryotic nuclei. Controversially, the Mus81-Eme1 endonuclease has been proposed to be an example of a eukaryotic nuclear resolvase. However, hitherto little or no HJ cleavage has been detected in recombinant preparations of Mus81-Eme1. Here, we report the purification of active forms of recombinant Schizosaccharomyces pombe Mus81-Eme1 and Saccharomyces cerevisiae Mus81-Mms4, which display robust HJ cleavage in vitro, which, in the case of Mus81-Eme1, is as good as the archetypal HJ resolvase RuvC in single turnover kinetic analysis. We also present genetic evidence that suggests that this activity might be utilised as a back-up to Mus81-Eme1's main activity of cleaving nicked HJs during meiosis in S. pombe.

  1. An Efficient Solution-Processed Intermediate Layer for Facilitating Fabrication of Organic Multi-Junction Solar Cells

    DEFF Research Database (Denmark)

    Ning Li; Baran, Derya; Forberich, Karen

    2013-01-01

    ):poly(styrenesulfonate) (PEDOT:PSS) is demonstrated for series-connected multi-junction organic solar cells (OSCs). Drying at 80 °C in air is sufficient for this solution-processed IML to obtain excellent functionality and reliability, which allow the use of most of high performance donor materials in the tandem structure...... simulations, which are reliable and promising guidelines for the design and investigation of multi-junction OSCs, are discussed. The outcome of optical and electrical simulations is in excellent agreement with the experimental data, indicating the outstanding efficiency and functionality of this solution...

  2. Two Distinct MUS81-EME1 Complexes from Arabidopsis Process Holliday Junctions1[W

    Science.gov (United States)

    Geuting, Verena; Kobbe, Daniela; Hartung, Frank; Dürr, Jasmin; Focke, Manfred; Puchta, Holger

    2009-01-01

    The MUS81 endonuclease complex has been shown to play an important role in the repair of stalled or blocked replication forks and in the processing of meiotic recombination intermediates from yeast to humans. This endonuclease is composed of two subunits, MUS81 and EME1. Surprisingly, unlike other organisms, Arabidopsis (Arabidopsis thaliana) has two EME1 homologs encoded in its genome. AtEME1A and AtEME1B show 63% identity on the protein level. We were able to demonstrate that, after expression in Escherichia coli, each EME1 protein can assemble with the unique AtMUS81 to form a functional endonuclease. Both complexes, AtMUS81-AtEME1A and AtMUS81-AtEME1B, are not only able to cleave 3′-flap structures and nicked Holliday junctions (HJs) but also, with reduced efficiency, intact HJs. While the complexes have the same cleavage patterns with both nicked DNA substrates, slight differences in the processing of intact HJs can be detected. Our results are in line with an involvement of both MUS81-EME1 endonuclease complexes in DNA recombination and repair processes in Arabidopsis. PMID:19339504

  3. Two distinct MUS81-EME1 complexes from Arabidopsis process Holliday junctions.

    Science.gov (United States)

    Geuting, Verena; Kobbe, Daniela; Hartung, Frank; Dürr, Jasmin; Focke, Manfred; Puchta, Holger

    2009-06-01

    The MUS81 endonuclease complex has been shown to play an important role in the repair of stalled or blocked replication forks and in the processing of meiotic recombination intermediates from yeast to humans. This endonuclease is composed of two subunits, MUS81 and EME1. Surprisingly, unlike other organisms, Arabidopsis (Arabidopsis thaliana) has two EME1 homologs encoded in its genome. AtEME1A and AtEME1B show 63% identity on the protein level. We were able to demonstrate that, after expression in Escherichia coli, each EME1 protein can assemble with the unique AtMUS81 to form a functional endonuclease. Both complexes, AtMUS81-AtEME1A and AtMUS81-AtEME1B, are not only able to cleave 3'-flap structures and nicked Holliday junctions (HJs) but also, with reduced efficiency, intact HJs. While the complexes have the same cleavage patterns with both nicked DNA substrates, slight differences in the processing of intact HJs can be detected. Our results are in line with an involvement of both MUS81-EME1 endonuclease complexes in DNA recombination and repair processes in Arabidopsis.

  4. Formation of antiwaves in gap-junction-coupled chains of neurons

    Science.gov (United States)

    Urban, Alexander; Ermentrout, Bard

    2012-07-01

    Using network models consisting of gap-junction-coupled Wang-Buszaki neurons, we demonstrate that it is possible to obtain not only synchronous activity between neurons but also a variety of constant phase shifts between 0 and π. We call these phase shifts intermediate stable phase-locked states. These phase shifts can produce a large variety of wavelike activity patterns in one-dimensional chains and two-dimensional arrays of neurons, which can be studied by reducing the system of equations to a phase model. The 2π periodic coupling functions of these models are characterized by prominent higher order terms in their Fourier expansion, which can be varied by changing model parameters. We study how the relative contribution of the odd and even terms affects what solutions are possible, the basin of attraction of those solutions, and their stability. These models may be applicable to the spinal central pattern generators of the dogfish and also to the developing neocortex of the neonatal rat.

  5. Doping Evolution and Junction Formation in Stacked Cyanine Dye Light-Emitting Electrochemical Cells.

    Science.gov (United States)

    Jenatsch, Sandra; Wang, Lei; Bulloni, Matia; Véron, Anna C; Ruhstaller, Beat; Altazin, Stéphane; Nüesch, Frank; Hany, Roland

    2016-03-01

    Cyanine dyes are fluorescent organic salts with intrinsic conductivity for ionic and electronic charges. Recently ( J. Am. Chem. Soc. 2013 , 135 , 18008 - 18011 ), these features have been exploited in cyanine light-emitting electrochemical cells (LECs). Here, we demonstrate that stacked, constant-voltage driven trimethine cyanine LECs with various counteranions develop a p-i-n junction that is composed of p- and n-doped zones and an intrinsic region where light-emission occurs. We introduce a method that combines spectral photocurrent response measurements with optical modeling and find that at maximum current the intrinsic region is centered at ∼37% away from the anode. Transient capacitance, photoluminescence and attenuance experiments indicate a device situation with a narrow p-doped region, an undoped region that occupies ∼72% of the dye layer thickness and an n-doped region with a maximum doping concentration of 0.08 dopant/cyanine molecule. Finally, we observe that during device relaxation the parent cyanines are not reformed. We ascribe this to irreversible reactions between doped cyanine radicals. For sterically conservative cyanine dyes, this suggests that undesired radical decomposition pathways limit the LEC long-term stability in general.

  6. ATP Is Required and Advances Cytokine-Induced Gap Junction Formation in Microglia In Vitro

    Directory of Open Access Journals (Sweden)

    Pablo J. Sáez

    2013-01-01

    Full Text Available Microglia are the immune cells in the central nervous system. After injury microglia release bioactive molecules, including cytokines and ATP, which modify the functional state of hemichannels (HCs and gap junction channels (GJCs, affecting the intercellular communication via extracellular and intracellular compartments, respectively. Here, we studied the role of extracellular ATP and several cytokines as modulators of the functional state of microglial HCs and GJCs using dye uptake and dye coupling techniques, respectively. In microglia and the microglia cell line EOC20, ATP advanced the TNF-α/IFN-γ-induced dye coupling, probably through the induction of IL-1β release. Moreover, TNF-α/IFN-γ, but not TNF-α plus ATP, increased dye uptake in EOC20 cells. Blockade of Cx43 and Panx1 HCs prevented dye coupling induced by TNF-α/IFN-γ, but not TNF-α plus ATP. In addition, IL-6 prevented the induction of dye coupling and HC activity induced by TNF-α/IFN-γ in EOC20 cells. Our data support the notion that extracellular ATP affects the cellular communication between microglia through autocrine and paracrine mechanisms, which might affect the timing of immune response under neuroinflammatory conditions.

  7. JAM-A and aPKC: A close pair during cell-cell contact maturation and tight junction formation in epithelial cells.

    Science.gov (United States)

    Ebnet, Klaus

    2013-01-01

    Cell-cell adhesion plays a critical role in the formation of barrier-forming epithelia. The molecules which mediate cell-cell adhesion frequently act as signaling molecules by recruiting and/or assembling cytoplasmic protein complexes. Junctional Adhesion Molecule (JAM)-A interacts with the cell polarity protein PAR-3, a member of the PAR-3-aPKC-PAR-6 complex, which regulates the formation of cell-cell contacts and the development of tight junctions (TJs). In our recent study we found that JAM-A is localized at primordial, spot-like cell-cell junctions (pAJs) in a non-phosphorylated form. After the recruitment of the PAR-aPKC complex and its activation at pAJs, aPKC phosphorylates JAM-A at Ser285 to promote the maturation of immature junctions. In polarized epithelial cells, aPKC phosphorylates JAM-A selectively at the TJs to maintain the barrier function of TJs. Thus, through mutual regulation, JAM-A and aPKC form a functional unit that regulates the establishment of barrier-forming junctions in vertebrate epithelial cells.

  8. Involvement of YAP, TAZ and HSP90 in contact guidance and intercellular junction formation in corneal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Vijay Krishna Raghunathan

    Full Text Available The extracellular environment possesses a rich milieu of biophysical and biochemical signaling cues that are simultaneously integrated by cells and influence cellular phenotype. Yes-associated protein (YAP and transcriptional co-activator with PDZ-binding motif (WWTR1; TAZ, two important signaling molecules of the Hippo pathway, have been recently implicated as nuclear relays of cytoskeletal changes mediated by substratum rigidity and topography. These proteins intersect with other important intracellular signaling pathways (e.g. Wnt and TGFβ. In the cornea, epithelial cells adhere to the stroma through a 3-dimensional topography-rich basement membrane, with features in the nano-submicron size-scale that are capable of profoundly modulating a wide range of fundamental cell behaviors. The influences of substratum-topography, YAP/TAZ knockdown, and HSP90 inhibition on cell morphology, YAP/TAZ localization, and the expression of TGFβ2 and CTGF, were investigated. The results demonstrate (a that knockdown of TAZ enhances contact guidance in a YAP dependent manner, (b that CTGF is predominantly regulated by YAP and not TAZ, and (c that TGFβ2 is regulated by both YAP and TAZ in these cells. Additionally, inhibition of HSP90 resulted in nuclear localization and subsequent transcriptional-activation of YAP, formation of cell-cell junctions and co-localization of E-cadherin and β-catenin at adherens junctions. Results presented in this study reflect the complexities underlying the molecular relationships between the cytoskeleton, growth factors, heat shock proteins, and co-activators of transcription that impact mechanotransduction. The data reveal the importance of YAP/TAZ on the cell behaviors, and gene and protein expression.

  9. Droplet formation in a T-shaped microchannel junction: A model system for membrane emulsification

    NARCIS (Netherlands)

    Graaf, van der S.; Steegmans, M.L.J.; Sman, van der R.G.M.; Schroën, C.G.P.H.; Boom, R.M.

    2005-01-01

    Droplet formation was studied in a glass microchip with a small channel containing to-be-dispersed phase perpendicular to a large channel with a cross-flowing continuous phase. This resembles the situation during cross-flow membrane emulsification. In this model system, droplets are formed at a

  10. Speed distributions at a controlled junction using microscopic real data from image processing

    NARCIS (Netherlands)

    Wilmink, I.R.; Arem, B. van

    2008-01-01

    Modeling realistic driving behavior at signalized junctions is fundamental for many applications, for instance for determining the signal capacity or for estimating traffic emissions. For these measures, the knowledge of speed, acceleration and deceleration of individual vehicles passing the signal

  11. Speed distributions at a controlled junction using microscopic real data from image processing

    NARCIS (Netherlands)

    Wilmink, I.R.; Arem, B. van

    2008-01-01

    Modeling realistic driving behavior at signalized junctions is fundamental for many applications, for instance for determining the signal capacity or for estimating traffic emissions. For these measures, the knowledge of speed, acceleration and deceleration of individual vehicles passing the signal

  12. Plasma Separation Process: Betacell (BCELL) code: User's manual. [Bipolar barrier junction

    Energy Technology Data Exchange (ETDEWEB)

    Taherzadeh, M.

    1987-11-13

    The emergence of clearly defined applications for (small or large) amounts of long-life and reliable power sources has given the design and production of betavoltaic systems a new life. Moreover, because of the availability of the plasma separation program, (PSP) at TRW, it is now possible to separate the most desirable radioisotopes for betacell power generating devices. A computer code, named BCELL, has been developed to model the betavoltaic concept by utilizing the available up-to-date source/cell parameters. In this program, attempts have been made to determine the betacell energy device maximum efficiency, degradation due to the emitting source radiation and source/cell lifetime power reduction processes. Additionally, comparison is made between the Schottky and PN junction devices for betacell battery design purposes. Certain computer code runs have been made to determine the JV distribution function and the upper limit of the betacell generated power for specified energy sources. A Ni beta emitting radioisotope was used for the energy source and certain semiconductors were used for the converter subsystem of the betacell system. Some results for a Promethium source are also given here for comparison. 16 refs.

  13. Orbital entanglement in bond-formation processes

    CERN Document Server

    Boguslawski, Katharina; Barcza, Gergely; Legeza, Ors; Reiher, Markus

    2013-01-01

    The accurate calculation of the (differential) correlation energy is central to the quantum chemical description of bond-formation and bond-dissociation processes. In order to estimate the quality of single- and multi-reference approaches for this purpose, various diagnostic tools have been developed. In this work, we elaborate on our previous observation [J. Phys. Chem. Lett. 3, 3129 (2012)] that one- and two-orbital-based entanglement measures provide quantitative means for the assessment and classification of electron correlation effects among molecular orbitals. The dissociation behavior of some prototypical diatomic molecules features all types of correlation effects relevant for chemical bonding. We demonstrate that our entanglement analysis is convenient to dissect these electron correlation effects and to provide a conceptual understanding of bond-forming and bond-breaking processes from the point of view of quantum information theory.

  14. Effect of gating and pressure on the electronic transport properties of crossed nanotube junctions: formation of a Schottky barrier

    Energy Technology Data Exchange (ETDEWEB)

    Havu, P; Hashemi, M J; Kaukonen, M; Nieminen, R M [Department of Applied Physics, Aalto University, PO Box 11100, FI-00076 Aalto (Finland); Seppaelae, E T [Nokia Research Center, Itaemerenkatu 11-13, FI-00180 Helsinki (Finland)

    2011-03-23

    The electronic transport properties of crossed carbon nanotube junctions are investigated using ab initio methods. The optimal atomic structures and the intertube distances of the junctions are obtained using van der Waals corrected density functional theory. The effect of gating on the intertube conductance of the junctions is explored, showing the charge accumulation to the nanotube contact and the charge depletion region at the metal-semiconductor Schottky contact. Finally, it is shown how the conductance of the junctions under the gate voltage is affected by pressure applied to the nanotube film. (fast track communication)

  15. Expression pattern of odontogenic ameloblast-associated and amelotin during formation and regeneration of the junctional epithelium

    Directory of Open Access Journals (Sweden)

    S Kuroda

    2010-12-01

    Full Text Available The junctional epithelium (JE adheres to the tooth surface, and seals off periodontal tissues from the oral environment. This incompletely differentiated epithelium is formed initially by the fusion of the reduced enamel organ with the oral epithelium (OE. Two proteins, odontogenic ameloblast-associated (ODAM and amelotin (AMTN, have been identified in the JE. The objective of this study was to evaluate their expression pattern during formation and regeneration of the JE. Cytokeratin 14 was used as a differentiation marker for oral epithelial cells, and Ki67 for cell proliferation. Immunohistochemistry was carried out on erupting rat molars, and in regenerating JE following gingivectomy. In the reducing enamel organ and in established JE, ODAM and AMTN were present at the cell-tooth interface while only ODAM and CK14 were found throughout the JE. Both were also conspicuously present in cell clusters situated between the erupting tooth and OE. During JE regeneration, ODAM was detected first at the leading wound edge and then in the regenerating JE. Some cell clusters in the subjacent connective tissue were also positive for ODAM. AMTN appeared later and both AMTN and ODAM accumulated at the interface with the tooth. Cytokeratin 14 gradually appeared in the regenerating JE but the cell clusters showed variable labeling. Cells associated with JE formation and regeneration exhibited higher division activity than adjacent epithelial cells. These findings suggest that ODAM and AMTN have a role at the cell-tooth interface, and that ODAM is likely also implicated in cellular events during formation and regeneration of the JE.

  16. The role of gap junctions and mechanical loading on mineral formation in a collagen-I scaffold seeded with osteoprogenitor cells.

    Science.gov (United States)

    Damaraju, Swathi; Matyas, John R; Rancourt, Derrick E; Duncan, Neil A

    2015-05-01

    Fracture nonunions represent one of many large bone defects where current treatment strategies fall short in restoring both form and function of the injured tissue. In this case, the use of a tissue-engineered scaffold for promoting bone healing offers an accessible and easy-to-manipulate environment for studying bone formation processes in vitro. We have previously shown that mechanical prestimulation using confined compression of differentiating osteoblasts results in an increase in mineralization formed in a 3D collagen-I scaffold. This study builds on this knowledge by evaluating the short and long-term effects of blocking gap junction-mediated intercellular communication among osteogenic cells on their effectiveness to mineralize collagen-I scaffolds in vitro, and in the presence and absence of mechanical stimulation. In this study, confined compression was applied in conjunction with octanol (a general communication blocker) or 18-α-glycerrhetinic acid (AGA, a specific gap junction blocker) using a modified FlexCell plate to collagen-I scaffolds seeded with murine embryonic stem cells stimulated toward osteoblast differentiation using beta-glycerol phosphate. The activity, presence, and expression of osteoblast cadherin, connexin-43, as well as various pluripotent and osteogenic markers were examined at 5-30 days of differentiation. Fluorescence recovery after photobleaching, immunofluorescence, viability, histology assessments, and reverse-transcriptase polymerase chain reaction assessments revealed that inhibiting communication in this scaffold altered the lineage and function of differentiating osteoblasts. In particular, treatment with communication inhibitors caused reduced mineralization in the matrix, and dissociation between connexin-43 and integrin α5β1. This dissociation was not restored even after long-term recovery. Thus, in order for this scaffold to be considered as an alternative strategy for the repair of large bone defects, cell

  17. Syringomyelia associated with arachnoid septum at the craniovertebral junction, contradicting the currently prevailing theory of syringomyelia formation.

    Science.gov (United States)

    Chang, Han Soo; Tsuchiya, Tsukasa; Fujisawa, Naoaki; Oya, Soichi; Matsui, Toru

    2012-01-01

    Despite a number of various hypotheses in the literature, the pathophysiology of syringomyelia is still not well understood. In this article, we report two cases of cervical syringomyelia not associated with Chiari I malformation. Both cases had a septum-like structure in the subarachnoid space on the dorsal side of the cord at the craniovertebral junction. Cardiac-gated phase-contrast cine-mode magnetic resonance imaging (MRI) demonstrated decreased cerebrospinal fluid (CSF) flow on the dorsal side of the spinal cord. Surgical excision of this septum, restoring the CSF flow, resulted in a prompt reduction of the syrinx size in both cases. Findings in these cases contradict the currently prevailing hypothesis of syrinx formation that postulate that the piston-like movement of the cerebellar tonsils enhance the pulsatile CSF flow in the spinal subarachnoid space, driving the CSF into the syrinx through the perivascular space of Virchow and Robin. The authors propose that a mechanism based on the decreased pulsatile CSF flow in the spinal subarachnoid space will be more suitable as a hypothesis in studying the pathophyisiology of syringomyelia. These cases also provide an important lesson in managing the patients with syringomyelia not associated with Chiari I malformation.

  18. Semiconductor device PN junction fabrication using optical processing of amorphous semiconductor material

    Science.gov (United States)

    Sopori, Bhushan; Rangappan, Anikara

    2014-11-25

    Systems and methods for semiconductor device PN junction fabrication are provided. In one embodiment, a method for fabricating an electrical device having a P-N junction comprises: depositing a layer of amorphous semiconductor material onto a crystalline semiconductor base, wherein the crystalline semiconductor base comprises a crystalline phase of a same semiconductor as the amorphous layer; and growing the layer of amorphous semiconductor material into a layer of crystalline semiconductor material that is epitaxially matched to the lattice structure of the crystalline semiconductor base by applying an optical energy that penetrates at least the amorphous semiconductor material.

  19. Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles.

    Science.gov (United States)

    Wei, Xi; Syed, Abeer; Mao, Pan; Han, Jongyoon; Song, Yong-Ak

    2016-03-13

    Polydimethylsiloxane (PDMS) is the prevailing building material to make microfluidic devices due to its ease of molding and bonding as well as its transparency. Due to the softness of the PDMS material, however, it is challenging to use PDMS for building nanochannels. The channels tend to collapse easily during plasma bonding. In this paper, we present an evaporation-driven self-assembly method of silica colloidal nanoparticles to create nanofluidic junctions with sub-50 nm pores between two microchannels. The pore size as well as the surface charge of the nanofluidic junction is tunable simply by changing the colloidal silica bead size and surface functionalization outside of the assembled microfluidic device in a vial before the self-assembly process. Using the self-assembly of nanoparticles with a bead size of 300 nm, 500 nm, and 900 nm, it was possible to fabricate a porous membrane with a pore size of ~45 nm, ~75 nm and ~135 nm, respectively. Under electrical potential, this nanoporous membrane initiated ion concentration polarization (ICP) acting as a cation-selective membrane to concentrate DNA by ~1,700 times within 15 min. This non-lithographic nanofabrication process opens up a new opportunity to build a tunable nanofluidic junction for the study of nanoscale transport processes of ions and molecules inside a PDMS microfluidic chip.

  20. Sputtered Zn(O,S) for junction formation in chalcopyrite-based thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Grimm, A.; Just, J.; Kieven, D.; Lauermann, I.; Rissom, T.; Klenk, R. [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Berlin (Germany); Palm, J. [AVANCIS GmbH and Co. KG, Munich (Germany); Neisser, A. [Sulfurcell Solartechnik GmbH, Berlin (Germany)

    2010-06-15

    In an effort to eliminate the standard CdS buffer layer from chalcopyrite-based thin film solar cells we have investigated sputtered Zn(O,S) films. They were prepared by partially reactive sputtering from a ZnS target in an argon/oxygen mixture. Single phase, polycrystalline films were achieved for substrate temperatures of at least 100 C. Test devices prepared in a completely dry process showed superior blue response and active area conversion efficiencies up to 13.7%. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. The Formation of Data on Nanotechnological Processes

    Directory of Open Access Journals (Sweden)

    Oleynik Olga Stepanovna

    2015-05-01

    Full Text Available The article presents the statistical monitoring of the main trends of nanotechnology development in Russia, as well as the review of the modern programs and documents devoted to urgent issues of nanotechnology development. The formation of system of statistical monitoring of nanotechnologies development in the Russian Federation includes the development of methodology and tools of statistical supervision over creation, commercialization, the use of nanotechnologies, and also the nanotechnological production. The authors carry out the analysis of the main directions and structure of co-funding of “The Program of nanotech industry development in the Russian Federation till 2015”. The sources of official statistical data on nanotechnologies in Russia are considered. The purpose of forming this essentially new direction of statistics consists in the creation of system of collecting, processing and submission of the regular, systematized and complex data which are adequately reflecting the state, the level of development and the prospects of nanotechnological sphere capacity which provide informational support to state policy and adoption of reasonable administrative decisions. The authors describe the system of statistical observations in the sphere of nanotechnologies. Today the statistics of nanotechnologies in Russia remains at the stage of formation and modernization according to the international standards, being supplemented every year with the new indicators which allow investigating different sides and tendencies of nanotech industry development. Nowadays the following aspects of the activity connected with nanotechnologies have already being studied by means of statistical methods: scientific research and developments; creation and use of nanotechnologies; demand for staff; production, including the innovative one.

  2. High efficiency back-contact back-junction thin-film monocrystalline silicon solar cells from the porous silicon process

    Science.gov (United States)

    Haase, F.; Kajari-Schröder, S.; Brendel, R.

    2013-11-01

    This work demonstrates the fabrication of a 45 μm thick back-contact back-junction thin-film monocrystalline silicon solar cell from the porous silicon process with an energy conversion efficiency of 18.9%. We demonstrate an efficiency improvement of 5.4% absolute compared to our prior record of 13.5% for back-contact back-junction thin-film monocrystalline silicon solar cells. This increase in efficiency is achieved by reducing the recombination at the base contact using a back surface field and by increasing the generation with a front texture. We investigate the loss mechanisms in the cell using finite element simulations. A free energy loss analysis based on experiments and simulations determines the dominating loss mechanisms. The efficiency loss by base recombination is 0.8% absolute and the loss by base contact recombination is 0.5% absolute in the 18.9% efficiency cell.

  3. Analysis of the turn-on process in 6 kV 4H-SiC junction diodes

    Science.gov (United States)

    Mnatsakanov, T. T.; Levinshtein, M. E.; Ivanov, P. A.; Palmour, J. W.; Das, M.; Agarwal, A. K.

    2005-01-01

    The switch-on process in 6 kV 4H-SiC junction diodes has been investigated experimentally and theoretically. The results of a detailed computer simulation are compared with the data furnished by the analytical theory. It is demonstrated that, at high current densities exceeding the critical value jcr = eNDvs (e is the elementary charge, ND is the base doping level, and vs is the carrier saturation velocity) and rather short current rise time (1 ns), an extremely fast base modulation can be achieved. In this mode, the base is spanned by an electron front that moves from the n+-n to the p+-n emitter with a velocity vs and by a relatively slow quasi-neutral hole front moving in the opposite direction, from the p+-n to the n+-n junction.

  4. Low-Cost, Manufacturable, 6-Inch Wafer Bonding Process for Next-Generation 5-Junction IMM+Ge Photovoltaic Devices Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the development of a 6-inch wafer bonding process to allow bonding of a multi-junction inverted metamorphic (IMM) tandem solar cell structure to an...

  5. Low-cost process for P-N junction-type solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Mooney, J.B.; Cubicciotti, D.D.; Bates, C.W. Jr.

    1980-03-01

    Spray pyrolysis of CuInS/sub 2/ was studied. The concentrations of copper and sulfur in the spray solutions were increased so as to increase the copper content of the films to the stoichiometric level. Although Auger analysis indicates that this was successful, x ray microanalysis has identified the growth of copper-rich crystals on the surfaces of the deposit. Heat treatment in H/sub 2/S did not improve the stoichiometry. The copper-rich crystals were also found on a sample sprayed from a solution with no excess copper. Heterojunctions of glass/SnO/sub 2/(Sb)/CdS/CdTe/carbon(Cu)/Ag-In were prepared with a number of methods used to restrict the junction. The various devices failed to exhibit a diode characteristic or a photo-response. Work on this project is being directed toward understanding the type of junction and how it is formed.

  6. Gap junction communication in myelinating glia.

    Science.gov (United States)

    Nualart-Marti, Anna; Solsona, Carles; Fields, R Douglas

    2013-01-01

    Gap junction communication is crucial for myelination and axonal survival in both the peripheral nervous system (PNS) and central nervous system (CNS). This review examines the different types of gap junctions in myelinating glia of the PNS and CNS (Schwann cells and oligodendrocytes respectively), including their functions and involvement in neurological disorders. Gap junctions mediate intercellular communication among Schwann cells in the PNS, and among oligodendrocytes and between oligodendrocytes and astrocytes in the CNS. Reflexive gap junctions mediating transfer between different regions of the same cell promote communication between cellular compartments of myelinating glia that are separated by layers of compact myelin. Gap junctions in myelinating glia regulate physiological processes such as cell growth, proliferation, calcium signaling, and participate in extracellular signaling via release of neurotransmitters from hemijunctions. In the CNS, gap junctions form a glial network between oligodendrocytes and astrocytes. This transcellular communication is hypothesized to maintain homeostasis by facilitating restoration of membrane potential after axonal activity via electrical coupling and the re-distribution of potassium ions released from axons. The generation of transgenic mice for different subsets of connexins has revealed the contribution of different connexins in gap junction formation and illuminated new subcellular mechanisms underlying demyelination and cognitive defects. Alterations in metabolic coupling have been reported in animal models of X-linked Charcot-Marie-Tooth disease (CMTX) and Pelizaeus-Merzbarcher-like disease (PMLD), which are caused by mutations in the genes encoding for connexin 32 and connexin 47 respectively. Future research identifying the expression and regulation of gap junctions in myelinating glia is likely to provide a better understanding of myelinating glia in nervous system function, plasticity, and disease. This

  7. Nanostructured p-type CZTS thin films prepared by a facile solution process for 3D p-n junction solar cells.

    Science.gov (United States)

    Park, Si-Nae; Sung, Shi-Joon; Sim, Jun-Hyoung; Yang, Kee-Jeong; Hwang, Dae-Kue; Kim, JunHo; Kim, Gee Yeong; Jo, William; Kim, Dae-Hwan; Kang, Jin-Kyu

    2015-07-07

    Nanoporous p-type semiconductor thin films prepared by a simple solution-based process with appropriate thermal treatment and three-dimensional (3D) p-n junction solar cells fabricated by depositing n-type semiconductor layers onto the nanoporous p-type thin films show considerable photovoltaic performance compared with conventional thin film p-n junction solar cells. Spin-coated p-type Cu2ZnSnS4 (CZTS) thin films prepared using metal chlorides and thiourea show unique nanoporous thin film morphology, which is composed of a cluster of CZTS nanograins of 50-500 nm, and the obvious 3D p-n junction structure is fabricated by the deposition of n-type CdS on the nanoporous CZTS thin films by chemical bath deposition. The photovoltaic properties of 3D p-n junction CZTS solar cells are predominantly affected by the scale of CZTS nanograins, which is easily controlled by the sulfurization temperature of CZTS precursor films. The scale of CZTS nanograins determines the minority carrier transportation within the 3D p-n junction between CZTS and CdS, which are closely related with the photocurrent of series resistance of 3D p-n junction solar cells. 3D p-n junction CZTS solar cells with nanograins below 100 nm show power conversion efficiency of 5.02%, which is comparable with conventional CZTS thin film solar cells.

  8. FORMATION OF BUSINESS PROCESS MANAGEMENT ENGINEERING COMPANY

    OpenAIRE

    Khatskevich, L.; Shishkin, I.

    2012-01-01

    In the proposed paper the relevance of management on the basis of machine-building enterprise business process management, building management systems business process engineering company, based on individual organizational functions. Business-process approach is based on rethinking the concept of middle management, where leadership is fundamental to middle managers

  9. High-T(sub c) Superconductor-Normal-Superconductor Junctions with Polyimide-Passivated Ambient Temperature Edge Formation

    Science.gov (United States)

    Barner, J. B.; Kleinsasser, A. W.; Hunt, B. D.

    1996-01-01

    The ability to controllably fabricate High-Temperature Superconductor (HTS) S-Normal-S (SNS) Josephson Juntions (JJ's) enhances the possibilities fro many applications, including digital circuits, SQUID's, and mixers. A wide variety of approaches to fabricating SNS-like junctions has been tried and analyzed in terms of proximity effect behavior.

  10. Formation of a Stable p-n Junction in a Liquid-Gated MoS2 Ambipolar Transistor

    NARCIS (Netherlands)

    Zhang, Y. J.; Ye, J. T.; Yornogida, Y.; Takenobu, T.; Iwasa, Y.

    2013-01-01

    Molybdenum disulfide (MoS2) has gained attention because of its high mobility and circular dichroism. As a crucial step to merge these advantages into a single device, we present a method that electronically controls and locates p-n junctions in liquid-gated ambipolar MoS2 transistors. A bias-indepe

  11. Effect of Gas- and Liquid-injection Methods on Formation of Bubble and Liquid Slug at Merging Micro T-junction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jun Kyoung [Kyungnam Univ., Changwon (Korea, Republic of); Lee, Chi Young [Pukyong Nat’l Univ., Busan (Korea, Republic of)

    2016-04-15

    In the present experimental study, the effect of gas- and liquid-injected methods on the formation of bubble and liquid slug at the merging micro T-junction of a square microchannel with dimensions 600 μm × 600 μm was investigated. Nitrogen and water were used as test fluids. The superficial velocities of the liquid and gas were in the range of 0.05 - 1 m/s, and 0.1 - 1 m/s, respectively, where the Taylor flow was observed. The bubble length, liquid slug length, bubble velocity, and bubble generation frequency were measured by analyzing the images captured using a high-speed camera. Under similar inlet superficial velocity conditions, in the case of gas injection to the main channel at the merging T-junction (T{sub g}as-liquid), the lengths of the bubble and liquid slug were longer, and the bubble generation frequency was lower than in the case of liquid injection to the main channel at the merging T-junction (T{sub l}iquid-gas). On the other hand, in both cases, the bubble velocity was almost the same. The previous correlation proposed using experimental data for T{sub l}iquid-gas had predicted the present experimental data of bubble length, bubble velocity, liquid slug length, and bubble generation frequency for T{sub g}as-liquid to be ~24%, ~9%, ~39%, ~55%, respectively.

  12. Fabrication of Al/AlOx/Al Josephson junctions and superconducting quantum circuits by shadow evaporation and a dynamic oxidation process

    Institute of Scientific and Technical Information of China (English)

    Wu Yu-Lin; Deng Hui; Yu Hai-Feng; Xue Guang-Ming; Tian Ye; Li Jie; Chen Ying-Fei

    2013-01-01

    Besides serving as promising candidates for realizing quantum computing,superconducting quantum circuits are one of a few macroscopic physical systems in which fundamental quantum phenomena can be directly demonstrated and tested,giving rise to a vast field of intensive research work both theoretically and experimentally.In this paper we report our work on the fabrication of superconducting quantum circuits,starting from its building blocks:Al/AlOx/Al Josephson junctions.By using electron beam lithography patterning and shadow evaporation,we have fabricated aluminum Josephson junctions with a controllable critical current density (jc) and wide range of junction sizes from 0.01 μm2 up to 1 μm2.We have carried out systematical studies on the oxidation process in fabricating Al/AlOx/Al Josephson junctions suitable for superconducting flux qubits.Furthermore,we have also fabricated superconducting quantum circuits such as superconducting flux qubits and charge-flux qubits.

  13. Mathematical modeling of biomass fuels formation process.

    Science.gov (United States)

    Gaska, Krzysztof; Wandrasz, Andrzej J

    2008-01-01

    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.

  14. Endoplasmic reticulum-plasma membrane junctions: structure, function and dynamics.

    Science.gov (United States)

    Okeke, Emmanuel; Dingsdale, Hayley; Parker, Tony; Voronina, Svetlana; Tepikin, Alexei V

    2016-06-01

    Endoplasmic reticulum (ER)-plasma membrane (PM) junctions are contact sites between the ER and the PM; the distance between the two organelles in the junctions is below 40 nm and the membranes are connected by protein tethers. A number of molecular tools and technical approaches have been recently developed to visualise, modify and characterise properties of ER-PM junctions. The junctions serve as the platforms for lipid exchange between the organelles and for cell signalling, notably Ca(2+) and cAMP signalling. Vice versa, signalling events regulate the development and properties of the junctions. Two Ca(2+) -dependent mechanisms of de novo formation of ER-PM junctions have been recently described and characterised. The junction-forming proteins and lipids are currently the focus of vigorous investigation. Junctions can be relatively short-lived and simple structures, forming and dissolving on the time scale of a few minutes. However, complex, sophisticated and multifunctional ER-PM junctions, capable of attracting numerous protein residents and other cellular organelles, have been described in some cell types. The road from simplicity to complexity, i.e. the transformation from simple 'nascent' ER-PM junctions to advanced stable multiorganellar complexes, is likely to become an attractive research avenue for current and future junctologists. Another area of considerable research interest is the downstream cellular processes that can be activated by specific local signalling events in the ER-PM junctions. Studies of the cell physiology and indeed pathophysiology of ER-PM junctions have already produced some surprising discoveries, likely to expand with advances in our understanding of these remarkable organellar contact sites. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  15. Dross formation during laser cutting process

    Energy Technology Data Exchange (ETDEWEB)

    Yilbas, B S; Aleem, B J Abdul [Mechanical Engineering Department, King Fahd University of Petoleum and Minerals, Dhahran 32161 (Saudi Arabia)

    2006-04-07

    Melt formation during laser cutting of metallic substrates is considered and the melt thickness is formulated using a lump parameter analysis. The droplet diameter is also predicted and compared with the experimental results. A CO{sub 2} laser with variable pulse frequency is used in the experiment. Oxygen, as assisting gas, impinging coaxially with the laser beam, is used at different pressures. SEM and XRD are carried out to obtain micrographs and oxide compounds formed in the dross. It is found that the liquid layer thickness increases with increasing laser output power and reduces with increasing assisting gas velocity. The droplet formed is spherical and the droplet size predicted agrees well with the experimental results.

  16. Export Processing Zones and Global Class Formation

    NARCIS (Netherlands)

    Neveling, Patrick

    2015-01-01

    This chapter is concerned with one of the most striking developments in the global political economy of capitalism after the Second World War; the rise of export processing zones and special economic zones. Building on long-term ethnohistorical research on the zones’ global spread from one zone in

  17. Export Processing Zones and Global Class Formation

    NARCIS (Netherlands)

    Neveling, Patrick

    2015-01-01

    This chapter is concerned with one of the most striking developments in the global political economy of capitalism after the Second World War; the rise of export processing zones and special economic zones. Building on long-term ethnohistorical research on the zones’ global spread from one zone in P

  18. Embryogenesis, a process of pattern formation

    Institute of Scientific and Technical Information of China (English)

    Meng-Xiang SUN

    2011-01-01

    @@ Plant embryogenesis is traditionally defined as a develop-mental process from zygote to mature embryo, which has the potential to form a complete plant (Bhojwani, 1974; Hu,2005).In dicotyledonous species, the fertilized egg or zygote usually divides according to a stereotyped pattern and gives rise to an embryo that consists of an embryonic shoot,cotyledons, hypocotyls, and an embryonic root.Thus, the basic body plan of the plant is established during the embryogenesis.Interestingly, the shoot-leaf-stem structure,not including the root, is repeatedly photocopied as a basic unit throughout plant vegetative growth (Wolpert et al.,2002).

  19. Spray formation processes of impinging jet injectors

    Science.gov (United States)

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

    1993-11-01

    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.

  20. Illegitimate V(D)J recombination-mediated deletions in Notch1 and Bcl11b are not sufficient for extensive clonal expansion and show minimal age or sex bias in frequency or junctional processing

    Energy Technology Data Exchange (ETDEWEB)

    Champagne, Devin P., E-mail: devin.champagne@uvm.edu; Shockett, Penny E., E-mail: pshockett@selu.edu

    2014-03-15

    Highlights: • Examines illegitimate V(D)J deletion junctions in Notch1 and Bcl11b. • Suggests little influence of deletions alone on clonal outgrowth in wild-type mice. • No age or sex biases in frequency, clonality, or junctional processing observed. • Contrasts with previous results at TCRβ and HPRT1 loci. • Deletions in Bcl11b may be tolerated more easily than those in Notch1. - Abstract: Illegitimate V(D)J recombination at oncogenes and tumor suppressor genes is implicated in formation of several T cell malignancies. Notch1 and Bcl11b, genes involved in developing T cell specification, selection, proliferation, and survival, were previously shown to contain hotspots for deletional illegitimate V(D)J recombination associated with radiation-induced thymic lymphoma. Interestingly, these deletions were also observed in wild-type animals. In this study, we conducted frequency, clonality, and junctional processing analyses of Notch1 and Bcl11b deletions during mouse development and compared results to published analyses of authentic V(D)J rearrangements at the T cell receptor beta (TCRβ) locus and illegitimate V(D)J deletions observed at the human, nonimmune HPRT1 locus not involved in T cell malignancies. We detect deletions in Notch1 and Bcl11b in thymic and splenic T cell populations, consistent with cells bearing deletions in the circulating lymphocyte pool. Deletions in thymus can occur in utero, increase in frequency between fetal and postnatal stages, are detected at all ages examined between fetal and 7 months, exhibit only limited clonality (contrasting with previous results in radiation-sensitive mouse strains), and consistent with previous reports are more frequent in Bcl11b, partially explained by relatively high Recombination Signal Information Content (RIC) scores. Deletion junctions in Bcl11b exhibit greater germline nucleotide loss, while in Notch1 palindromic (P) nucleotides are more abundant, although average P nucleotide length is

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

    Science.gov (United States)

    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...

  2. A Process Model of Family Formation and Development

    Science.gov (United States)

    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…

  3. INSTITUTIONAL ENVIRONMENT OF THE AGRICULTURAL MARKET FORMATION PROCESS

    Directory of Open Access Journals (Sweden)

    S. Revenko

    2013-11-01

    Full Text Available This article considers institutional aspects of the organized agricultural market formation process. Theoretical base to distinguish institute and institutes is given. In order to find out main influential institutes of the “organization” phenomenon author analyses Ukrainian institutional environment that is under construction process. Author considers main processes which are running during the organized market formation. Author researches theoretical approaches to the institutional staff. In order to structure the most common approaches and theoretical knowledge of this problem author proposes few schemes. Author’s points of view for many questions of the organized market formation process are proposed. Researcher analyzes effectiveness of the institutes and governmental regulation of the agricultural market. Readers can find strategically new approach to the agricultural market formation policy from the governmental point of view. Essence of the socioeconomic formation of agricultural market is considered. Main factors of agriculture market formation are outlined. Agricultural market structural parts consideration systematic approach is proposed. Ineffectiveness of the agriculture market relations without regulation process is proved. The most unfavorable reasons of the agricultural market formation are determined.

  4. Numerical Simulation of Chip Formation in Metal Cutting Process

    Directory of Open Access Journals (Sweden)

    HUANG Meixia

    2012-07-01

    Full Text Available In order to study the chip formation mechanism in metal cutting process, based on finite element software ABAQUS, establish finite element model, and carry out numerical simulation on serrated chip formation of Ni-base superalloy GH4169 and ribbon chip formation of 45# steel respectively.In addition, analyze the influence law of three factors (cutting speed, feed rate, back cutting depth on cutting force and the distribution rule of cutting heat in serrated chip formation of GH4169.  

  5. Homo-junction ferroelectric field-effect-transistor memory device using solution-processed lithium-doped zinc oxide thin films

    KAUST Repository

    Nayak, Pradipta K.

    2012-06-22

    High performance homo-junction field-effect transistor memory devices were prepared using solution processed transparent lithium-doped zinc oxide thin films for both the ferroelectric and semiconducting active layers. A highest field-effect mobility of 8.7 cm2/Vs was obtained along with an Ion/Ioff ratio of 106. The ferroelectric thin filmtransistors showed a low sub-threshold swing value of 0.19 V/dec and a significantly reduced device operating voltage (±4 V) compared to the reported hetero-junction ferroelectrictransistors, which is very promising for low-power non-volatile memory applications.

  6. Graphene-SnO2 nanocomposites decorated with quantum tunneling junctions: preparation strategies, microstructures and formation mechanism.

    Science.gov (United States)

    Wang, Qingxiu; Wu, Xianzheng; Wang, Lijun; Chen, Zhiwen; Wang, Shilong

    2014-09-28

    Tin dioxide (SnO2) and graphene are versatile materials that are vitally important for creating new functional and smart materials. A facile, simple and efficient ultrasonic-assisted hydrothermal synthesis approach has been developed to prepare graphene-SnO2 nanocomposites (GSNCs), including three samples with graphene/Sn weight ratios = 1 : 2 (GSNC-2), 1 : 1 (GSNC-1), and graphene oxide/Sn weight ratio = 1 : 1 (GOSNC-1). Low-magnification electron microscopy analysis indicated that graphene was exfoliated and adorned with SnO2 nanoparticles, which were dispersed uniformly on both the sides of the graphene nanosheets. High-magnification electron microscopy analysis confirmed that the graphene-SnO2 nanocomposites presented network tunneling frameworks, which were decorated with the SnO2 quantum tunneling junctions. The size distribution of SnO2 nanoparticles was estimated to range from 3 to 5.5 nm. Comparing GSNC-2, GSNC-1, and GOSNC-1, GOSNC-1 was found to exhibit a significantly better the homogeneous distribution and a considerably smaller size distribution of SnO2 nanoparticles, which indicated that it was better to use graphene oxide as a supporting material and SnCl4·5H2O as a precursor to synthesize hybrid graphene-SnO2 nanocomposites. Experimental results suggest that the graphene-SnO2 nanocomposites with interesting SnO2 quantum tunneling junctions may be a promising material to facilitate the improvement of the future design of micro/nanodevices.

  7. An outdoor investigation of the absorption degradation of single-junction amorphous silicon photovoltaic module due to localized heat/hot spot formation

    Indian Academy of Sciences (India)

    Osayemwenre Gilbert O; Meyer Edson L; Mamphweli Sampson

    2016-04-01

    This paper investigates the absorbance degradation of single-junction amorphous silicon (a-Si:H) photovoltaic (PV) module, due to the presence of localized heat. The decrease in optical density is a huge challenge due to the long-term degradation of PV modules. The reduction in solar cell optical density causes a decline in its conversion efficiency. This decreases the photogenerating current, hence reduces the effective efficiency of the PV device. An infrared thermography was used for mapping the module temperature profile. Fourier transform infrared spectroscopy (FTIR) was used for the absorption characterization. The rationale behind the outdoor deployment was to deduce a practical effect of hot spot formation on the module’s absorption ability.The results show a direct correlation between localized heat and the absorption degradation.

  8. Solar System Processes Underlying Planetary Formation, Geodynamics, and the Georeactor

    CERN Document Server

    Herndon, J M

    2006-01-01

    Only three processes, operant during the formation of the Solar System, are responsible for the diversity of matter in the Solar System and are directly responsible for planetary internal-structures, including planetocentric nuclear fission reactors, and for dynamical processes, including and especially, geodynamics. These processes are: (i) Low-pressure, low-temperature condensation from solar matter in the remote reaches of the Solar System or in the interstellar medium; (ii) High-pressure, high-temperature condensation from solar matter associated with planetary-formation by raining out from the interiors of giant-gaseous protoplanets, and; (iii) Stripping of the primordial volatile components from the inner portion of the Solar System by super-intense solar wind associated with T-Tauri phase mass-ejections, presumably during the thermonuclear ignition of the Sun. As described herein, these processes lead logically, in a causally related manner, to a coherent vision of planetary formation with profound imp...

  9. Quantum Junction Solar Cells

    KAUST Repository

    Tang, Jiang

    2012-09-12

    Colloidal quantum dot solids combine convenient solution-processing with quantum size effect tuning, offering avenues to high-efficiency multijunction cells based on a single materials synthesis and processing platform. The highest-performing colloidal quantum dot rectifying devices reported to date have relied on a junction between a quantum-tuned absorber and a bulk material (e.g., TiO 2); however, quantum tuning of the absorber then requires complete redesign of the bulk acceptor, compromising the benefits of facile quantum tuning. Here we report rectifying junctions constructed entirely using inherently band-aligned quantum-tuned materials. Realizing these quantum junction diodes relied upon the creation of an n-type quantum dot solid having a clean bandgap. We combine stable, chemically compatible, high-performance n-type and p-type materials to create the first quantum junction solar cells. We present a family of photovoltaic devices having widely tuned bandgaps of 0.6-1.6 eV that excel where conventional quantum-to-bulk devices fail to perform. Devices having optimal single-junction bandgaps exhibit certified AM1.5 solar power conversion efficiencies of 5.4%. Control over doping in quantum solids, and the successful integration of these materials to form stable quantum junctions, offers a powerful new degree of freedom to colloidal quantum dot optoelectronics. © 2012 American Chemical Society.

  10. INCLUSIVEEDUCATION CULTURE: ESPECIAL EDUCATION AND THE FORMATIVE PROCESSES OF TEACHERS

    Directory of Open Access Journals (Sweden)

    Guacira de Azambuja

    2012-12-01

    Full Text Available The articlepresents a bibliography research. Its objective is to discuss the formativeprocesses particularities of especial educational teacher by an inclusiveeducational culture. It was found thatexist specifities that mark the formation of special educational teacher. Thesespecificities are origin of historical educational context mark by NacionalPolicy on Inclusive Perspective. This perspective suggest the existence ofother factor that influenced and do influence the special education and theteachers in this area. Among the factors associated to this process are: socioculturalvariants, initial formation and the continuous formation. It’s concluded that notjust a challenging proposal in the formation of special educational teacher is enoughto effectively attend the student’s educational needs, it’s necessary to focusin the special educational ‘s laws and the development of public policies ofgeneral formation.

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

    Science.gov (United States)

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

    2015-08-03

    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.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Pablo Martínez

    2010-05-01

    Full Text Available 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.

  14. Optimization of a plasma immersion ion implantation process for shallow junctions in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Ashok; Nori, Rajashree; Bhatt, Piyush; Lodha, Saurabh; Pinto, Richard, E-mail: rpinto@ee.iitb.ac.in; Rao, Valipe Ramgopal [Department of Electrical Engineering, Indian Institute of Technology Bombay, Mumbai 400076 (India); Jomard, François; Neumann-Spallart, Michael [Groupe d' Étude de la Matière Condensée, C.N.R.S./Université de Versailles-St.Quentin, 45, Avenue des États-Unis, 78035 Versailles Cedex (France)

    2014-11-01

    A plasma immersion ion implantation (PIII) process has been developed for realizing shallow doping profiles of phosphorus and boron in silicon using an in-house built dual chamber cluster tool. High Si etch rates observed in a 5% PH{sub 3} in H{sub 2} plasma have been ascribed to high concentration of H(α) radicals. Therefore, subsequent work was carried out with 5% PH{sub 3} in He, leading to much smaller etch rates. By optical emission spectroscopy, the radical species H(α), PH*{sub 2}, and PH* have been identified. The concentration of all three species increased with pressure. Also, ion concentrations increased with pressure as evidenced by Langmuir data, with a maximum occurring at 0.12 mbar. The duty cycle of pulsed DC bias has a significant bearing on both the implantation and the etching process as it controls the leakage of positive charge collected at the surface of the silicon wafer during pulse on-time generated primarily due to secondary electron emission. The P implant process was optimized for a duty cycle of 10% or less at a pressure of 0.12 mbar with implant times as low as 30 s. Secondary ion mass spectroscopy showed a P dopant depth of 145 nm after rapid thermal annealing (RTA) at 950 °C for 5 s, resulting in a sheet resistance of 77 Ω/◻. Si n{sup +}/p diodes fabricated with phosphorus implantation using optimized PIII and RTA conditions exhibit J{sub on}/J{sub off} > 10{sup 6} with an ideality factor of nearly 1.2. Using similar conditions, shallow doping profiles of B in silicon have also been realized.

  15. Direct observation of the carrier transport process in InGaN quantum wells with a pn-junction

    Science.gov (United States)

    Wu, Haiyan; Ma, Ziguang; Jiang, Yang; Wang, Lu; Yang, Haojun; Li, Yangfeng; Zuo, Peng; Jia, Haiqiang; Wang, Wenxin; Zhou, Junming; Liu, Wuming; Chen, Hong

    2016-11-01

    A new mechanism of light-to-electricity conversion that uses InGaN/GaN QWs with a p-n junction is reported. According to the well established light-to-electricity conversion theory, quantum wells (QWs) cannot be used in solar cells and photodetectors because the photogenerated carriers in QWs usually relax to ground energy levels, owing to quantum confinement, and cannot form a photocurrent. We observe directly that more than 95% of the photoexcited carriers escape from InGaN/GaN QWs to generate a photocurrent, indicating that the thermionic emission and tunneling processes proposed previously cannot explain carriers escaping from QWs. We show that photoexcited carriers can escape directly from the QWs when the device is under working conditions. Our finding challenges the current theory and demonstrates a new prospect for developing highly efficient solar cells and photodetectors. Project supported by the National Natural Science Foundation of China (Grant Nos. 11574362, 61210014, and 11374340) and the Innovative Clean-energy Research and Application Program of Beijing Municipal Science and Technology Commission, China (Grant No. Z151100003515001).

  16. Key Properties of Solar Chromospheric Line Formation Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The distribution or wavelength-dependence of the formation regions of frequently used solar lines, Hα, Hβ, CaIIH and CaII8542, in quiet Sun, faint and bright flares is explored in the unpolarized case. We stress four aspects characterising the property of line formation process: 1) width of line formation core; 2) lineformation region; 3) influence of the temperature minimum region; and 4) wavelength ranges within which one can obtain pure chromospheric and photospheric filtergrams. It is shown that the above four aspects depend strongly on the atmo spheric physical condition and the lines used. The formation regions of all the wave length points within a line may be continuously distributed over one depth domain or discretely distributed because of no contribution coming from the temperature minimum reg:on, an important domain in the solar atmosphere that determines the distribution pattern of escape photons. On the other hand, the formation region of one wavelength point may cover only one height range or spread over two domains which are separated again by the temperature minimum region. Different lines may form in different regions in the quiet Sun. However, these line formation regions be come closer ir. solar flaring regions. Finally, though the stratification of line-of-sight velocity can alter the position of the line formation core within the line band and result in the asymmetry of the line formation core about the shifted line center, it can only lead to negligible changes in the line formation region or the line formation core width. All these results can be instructive to solar filtering observations.

  17. FORMATION OF VANILLIN AND SYRINGALDEHYDE IN AN OXYGEN DELIGNIFICATION PROCESS

    Directory of Open Access Journals (Sweden)

    Zhaojiang Wong

    2010-05-01

    Full Text Available The formation of vanillin and syringaldehyde during an oxygen delignification process was evaluated. The cleavage of conjugated Cα-Cβ bonds in phenolic lignin caused by the attack of oxygen leads to the formation of aromatic aldehydes and ketones. The formation mechanism was confirmed by the organic compounds identified in the spent liquor by GC/MS. Additionally, the formation of aromatic aldehydes and ketones of hardwood, softwood, and grass was investigated. The results showed that the formed aromatic aldehydes and ketones were related to the units of lignin structure. Among the aromatic aldehydes and ketones present in the spent liquor from oxygen delignification, vanillin and syringaldehyde are of high content, making the spent liquor a potential resource for vanillin and syringaldehyde production.

  18. Formation process of Malaysian modern architecture under influence of nationalism

    OpenAIRE

    宇高, 雄志; 山崎, 大智

    2001-01-01

    This paper examines the Formation Process of Malaysian Modern Architecture under Influence of Nationalism,through the process of independence of Malaysia. The national style as "Malaysian national architecture" which hasengaged on background of political environment under the post colonial situation. Malaysian urban design is alsodetermined under the balance of both of ethnic culture and the national culture. In Malaysia, they decided to choosethe Malay ethnic culture as the national culture....

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

    Science.gov (United States)

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

    2014-05-01

    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.

  20. Recovering probabilities for nucleotide trimming processes for T cell receptor TRA and TRG V-J junctions analyzed with IMGT tools.

    Science.gov (United States)

    Bleakley, Kevin; Lefranc, Marie-Paule; Biau, Gérard

    2008-10-02

    Nucleotides are trimmed from the ends of variable (V), diversity (D) and joining (J) genes during immunoglobulin (IG) and T cell receptor (TR) rearrangements in B cells and T cells of the immune system. This trimming is followed by addition of nucleotides at random, forming the N regions (N for nucleotides) of the V-J and V-D-J junctions. These processes are crucial for creating diversity in the immune response since the number of trimmed nucleotides and the number of added nucleotides vary in each B or T cell. IMGT sequence analysis tools, IMGT/V-QUEST and IMGT/JunctionAnalysis, are able to provide detailed and accurate analysis of the final observed junction nucleotide sequences (tool "output"). However, as trimmed nucleotides can potentially be replaced by identical N region nucleotides during the process, the observed "output" represents a biased estimate of the "true trimming process." A probabilistic approach based on an analysis of the standardized tool "output" is proposed to infer the probability distribution of the "true trimmming process" and to provide plausible biological hypotheses explaining this process. We collated a benchmark dataset of TR alpha (TRA) and TR gamma (TRG) V-J rearranged sequences and junctions analysed with IMGT/V-QUEST and IMGT/JunctionAnalysis, the nucleotide sequence analysis tools from IMGT, the international ImMunoGeneTics information system, http://imgt.cines.fr. The standardized description of the tool output is based on the IMGT-ONTOLOGY axioms and concepts. We propose a simple first-order model that attempts to transform the observed "output" probability distribution into an estimate closer to the "true trimming process" probability distribution. We use this estimate to test the hypothesis that Poisson processes are involved in trimming. This hypothesis was not rejected at standard confidence levels for three of the four trimming processes: TRAV, TRAJ and TRGV. By using trimming of rearranged TR genes as a benchmark, we

  1. Recovering probabilities for nucleotide trimming processes for T cell receptor TRA and TRG V-J junctions analyzed with IMGT tools

    Directory of Open Access Journals (Sweden)

    Lefranc Marie-Paule

    2008-10-01

    Full Text Available Abstract Background Nucleotides are trimmed from the ends of variable (V, diversity (D and joining (J genes during immunoglobulin (IG and T cell receptor (TR rearrangements in B cells and T cells of the immune system. This trimming is followed by addition of nucleotides at random, forming the N regions (N for nucleotides of the V-J and V-D-J junctions. These processes are crucial for creating diversity in the immune response since the number of trimmed nucleotides and the number of added nucleotides vary in each B or T cell. IMGT® sequence analysis tools, IMGT/V-QUEST and IMGT/JunctionAnalysis, are able to provide detailed and accurate analysis of the final observed junction nucleotide sequences (tool "output". However, as trimmed nucleotides can potentially be replaced by identical N region nucleotides during the process, the observed "output" represents a biased estimate of the "true trimming process." Results A probabilistic approach based on an analysis of the standardized tool "output" is proposed to infer the probability distribution of the "true trimmming process" and to provide plausible biological hypotheses explaining this process. We collated a benchmark dataset of TR alpha (TRA and TR gamma (TRG V-J rearranged sequences and junctions analysed with IMGT/V-QUEST and IMGT/JunctionAnalysis, the nucleotide sequence analysis tools from IMGT®, the international ImMunoGeneTics information system®, http://imgt.cines.fr. The standardized description of the tool output is based on the IMGT-ONTOLOGY axioms and concepts. We propose a simple first-order model that attempts to transform the observed "output" probability distribution into an estimate closer to the "true trimming process" probability distribution. We use this estimate to test the hypothesis that Poisson processes are involved in trimming. This hypothesis was not rejected at standard confidence levels for three of the four trimming processes: TRAV, TRAJ and TRGV. Conclusion By

  2. Mixing in T-junctions

    NARCIS (Netherlands)

    Kok, Jacobus B.W.; van der Wal, S.

    1996-01-01

    The transport processes that are involved in the mixing of two gases in a T-junction mixer are investigated. The turbulent flow field is calculated for the T-junction with the k- turbulence model by FLOW3D. In the mathematical model the transport of species is described with a mixture fraction

  3. COMMUNICATION COMPONENT FORMATION OF TEACHERS’ COMPETENCE IN THE MENTORING PROCESS

    Directory of Open Access Journals (Sweden)

    Vera T. Sopegina

    2016-01-01

    Full Text Available The aim of this article is to present the integration process and special pedagogical competence in solving production and pedagogical challenges in the educational organizations and production enterprises engaged in the training of mentors.Methods. The methods involve the analysis of psycho-pedagogical and methodological literature on the issue; analysis of the Federal State Educational Standards and professional standards; modeling of processes.Results and scientific novelty. The problems of formation of communicative competence in the preparation of teachers are considered. The characteristic of the formation levels of mentoring such as «mentor-formal»; «mentor-theoretician», a «mentor-coach»; «mentor-adviser»; «mentor-professional» are given. The pedagogical potential of the phenomenon of «mentoring» is disclosed; an innovative way of mentoring within the competence approach is shown. The integrative activity of the teacher in solving production and pedagogical problems is analysed.Practical significance. The results can be used by trainers and mentors in the formation of communicative competence of students. The implementation of integration model of pedagogical and production tasks will provide the formation of communicative competence as part of vocational training. Using the obtained results can improve the effectiveness of vocational teacher education.

  4. Dynamic Model Visualizing the Process of Viral Plaque Formation

    Directory of Open Access Journals (Sweden)

    Boriana Marintcheva

    2012-09-01

    Full Text Available In Microbiology and Virology courses, viral plaques are often presented to students as the way one can visualize viruses/bacteriophages. While students generally grasp the idea that counting plaques is essentially the same as counting viruses in their sample (assuming that one virus entering the cell is sufficient for productive infection, the process of plaque formation itself remains largely obscure. Many students fail to appreciate that viral plaques are actually a “laboratory-made” phenomenon allowing us to observe and study the growth of lytic viruses. The latter often presents a challenge for the interpretation of experimental data related to viral growth and drug discovery using plaque reduction assay. The hands-on model described here creates an opportunity for students to experience the process of viral plaque formation while engaging multiple senses and creating a lasting impression.  

  5. Ground-water flow and contaminant transport at a radioactive-materials processing site, Wood River Junction, Rhode Island

    Science.gov (United States)

    Ryan, Barbara J.; Kipp, Kenneth L.

    1997-01-01

    Liquid wastes from an enriched-uranium cold-scrap recovery plant at Wood River Junction, Rhode Island, were discharged to the environment through evaporation ponds and trenches from 1966 through 1980. Leakage from the ponds and trenches resulted in a plume of contaminated ground water extending northwestward to the Pawcatuck River through a highly permeable sand and gravel aquifer of glacial origin.

  6. The human myotendinous junction

    DEFF Research Database (Denmark)

    Knudsen, A B; Larsen, M; Mackey, Abigail

    2015-01-01

    The myotendinous junction (MTJ) is a specialized structure in the musculotendinous system, where force is transmitted from muscle to tendon. Animal models have shown that the MTJ takes form of tendon finger-like processes merging with muscle tissue. The human MTJ is largely unknown and has never ...

  7. Specific detection of DNA and RNA targets using a novel isothermal nucleic acid amplification assay based on the formation of a three-way junction structure.

    Science.gov (United States)

    Wharam, S D; Marsh, P; Lloyd, J S; Ray, T D; Mock, G A; Assenberg, R; McPhee, J E; Brown, P; Weston, A; Cardy, D L

    2001-06-01

    The formation of DNA three-way junction (3WJ) structures has been utilised to develop a novel isothermal nucleic acid amplification assay (SMART) for the detection of specific DNA or RNA targets. The assay consists of two oligonucleotide probes that hybridise to a specific target sequence and, only then, to each other forming a 3WJ structure. One probe (template for the RNA signal) contains a non-functional single-stranded T7 RNA polymerase promoter sequence. This promoter sequence is made double-stranded (hence functional) by DNA polymerase, allowing T7 RNA polymerase to generate a target-dependent RNA signal which is measured by an enzyme-linked oligosorbent assay (ELOSA). The sequence of the RNA signal is always the same, regardless of the original target sequence. The SMART assay was successfully tested in model systems with several single-stranded synthetic targets, both DNA and RNA. The assay could also detect specific target sequences in both genomic DNA and total RNA from Escherichia coli. It was also possible to generate signal from E.coli samples without prior extraction of nucleic acid, showing that for some targets, sample purification may not be required. The assay is simple to perform and easily adaptable to different targets.

  8. Process Dynamics and Fractal Analysis of New Phase Formation in Thermal Processes

    Institute of Scientific and Technical Information of China (English)

    Wang J; Shen Z.W; Shen Z. Q

    2001-01-01

    Boiling and fouling are taken as typical examples of new phase formation process to be analyzed and discussed in this paper. The process dynamics of nucleate boiling is analyzed and its mechanism is discussed from the view point of self-organization. Fouling, which is a more complicated phenomenon of new phase formation, involves series of underlying processes. The morphology and fractal analysis of fouling on low-energy surface and that with fouling inhibitors are studied and discussed. It is suggested that considering the process dynamics, fractal analysis and self-organization, a new avenue of research should be found.

  9. Doped semiconductor nanocrystal junctions

    Energy Technology Data Exchange (ETDEWEB)

    Borowik, Ł.; Mélin, T., E-mail: thierry.melin@isen.iemn.univ-lille1.fr [Institut d’Electronique, de Microélectronique et de Nanotechnologie, CNRS-UMR8520, Avenue Poincaré, F-59652 Villeneuve d’Ascq (France); Nguyen-Tran, T.; Roca i Cabarrocas, P. [Laboratoire de Physique des Interfaces et des Couches Minces, CNRS-UMR7647, Ecole Polytechnique, F-91128 Palaiseau (France)

    2013-11-28

    Semiconductor junctions are the basis of electronic and photovoltaic devices. Here, we investigate junctions formed from highly doped (N{sub D}≈10{sup 20}−10{sup 21}cm{sup −3}) silicon nanocrystals (NCs) in the 2–50 nm size range, using Kelvin probe force microscopy experiments with single charge sensitivity. We show that the charge transfer from doped NCs towards a two-dimensional layer experimentally follows a simple phenomenological law, corresponding to formation of an interface dipole linearly increasing with the NC diameter. This feature leads to analytically predictable junction properties down to quantum size regimes: NC depletion width independent of the NC size and varying as N{sub D}{sup −1/3}, and depleted charge linearly increasing with the NC diameter and varying as N{sub D}{sup 1/3}. We thus establish a “nanocrystal counterpart” of conventional semiconductor planar junctions, here however valid in regimes of strong electrostatic and quantum confinements.

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

    Directory of Open Access Journals (Sweden)

    Ma W.

    2012-08-01

    Full Text Available 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.

  11. Vertical triple-junction RGB optical sensor with signal processing based on the determination of the space-charge region borders.

    Science.gov (United States)

    Tadić, Nikša; Schidl, Stefan; Zimmermann, Horst

    2014-09-01

    A triple-junction RGB optical sensor with vertically stacked photodiodes and signal processing that provides precise values of the currents generated by blue, green, and red light is presented. The signal processing is based on the determination of the border depths of the space-charge regions of all three photodiodes. A current-mode implementation using current conveyors and variable-gain current amplifiers is introduced. The responsivities of all three photodiodes calculated using the proposed approach are in very good agreement with the measured results.

  12. Modeling of Fume Formation from Shielded Metal Arc Welding Process

    Science.gov (United States)

    Sivapirakasam, S. P.; Mohan, Sreejith; Santhosh Kumar, M. C.; Surianarayanan, M.

    2017-04-01

    In this study, a semi-empirical model of fume formation rate (FFR) from a shielded metal arc welding (SMAW) process has been developed. The model was developed for a DC electrode positive (DCEP) operation and involves the calculations of droplet temperature, surface area of the droplet, and partial vapor pressures of the constituents of the droplet to predict the FFR. The model was further extended for predicting FFR from nano-coated electrodes. The model estimates the FFR for Fe and Mn assuming constant proportion of other elements in the electrode. Fe FFR was overestimated, while Mn FFR was underestimated. The contribution of spatters and other mechanism in the arc responsible for fume formation were neglected. A good positive correlation was obtained between the predicted and experimental FFR values which highlighted the usefulness of the model.

  13. Modeling of Fume Formation from Shielded Metal Arc Welding Process

    Science.gov (United States)

    Sivapirakasam, S. P.; Mohan, Sreejith; Santhosh Kumar, M. C.; Surianarayanan, M.

    2017-01-01

    In this study, a semi-empirical model of fume formation rate (FFR) from a shielded metal arc welding (SMAW) process has been developed. The model was developed for a DC electrode positive (DCEP) operation and involves the calculations of droplet temperature, surface area of the droplet, and partial vapor pressures of the constituents of the droplet to predict the FFR. The model was further extended for predicting FFR from nano-coated electrodes. The model estimates the FFR for Fe and Mn assuming constant proportion of other elements in the electrode. Fe FFR was overestimated, while Mn FFR was underestimated. The contribution of spatters and other mechanism in the arc responsible for fume formation were neglected. A good positive correlation was obtained between the predicted and experimental FFR values which highlighted the usefulness of the model.

  14. Electrochemical Processes for the Formation of Hydroxyapatite Powders

    Directory of Open Access Journals (Sweden)

    Adrian Nur

    2014-10-01

    Full Text Available Electrochemical synthesis of hydroxyapatite particles was performed from a homogeneous solution of Na2H2EDTA.2H2O, KH2PO4 and CaCl2 without stirring to investigate the mechanism of hydroxyapa-tite formation. We found that OH- ions generated by water reduction at the cathode play an important role in the formation of hydroxyapatite particles. The OH- ions induce the liberation of Ca2+ ions and the dissociation of phosphoric acid, which serve as the reactants for the formation of hydroxyapatite particles. Two layers with a clear boundary were formed during electrolysis. The upper layer comprises the produced particles and the lower layer is a homogeneous solution. The produced particles were held in the region between the electrodes mainly due to the electrostatic interactions of charged particles in an electric field. The hydroxyapatite particles are agglomerates consisting of spherical particles. Aging the suspension for 24 h after electrolysis leads to the transformation of hydroxyapatite to brushite. Thus, if producing hydroxyapatite is desired, the particles should be continuously removed from the system. This method appears to be promising as a continuous process to produce hydroxyapatite parti-cles using an electrochemical method. © 2014 BCREC UNDIP. All rights reservedReceived: 10th April 2014; Revised: 25th May 2014; Accepted: 27th June 2014How to Cite: Nur, A., Setyawan, H., Widjaja, A., Lenggoro, I.W. (2014. Electrochemical Processes for the Formation of Hydroxyapatite Powders. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (3: 168-175. (doi:10.9767/bcrec.9.3.6686.168-175Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.3.6686.168-175

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Sputter deposition of Cu{sub 2}O thin films, nitrogen-doping and formation of Cu{sub 2}O-ZnO p/n junctions

    Energy Technology Data Exchange (ETDEWEB)

    Graubner, Swen; Kronenberger, Achim; Benz, Julian; Reppin, Daniel; Fischer, Martin; Polity, Angelika; Hofmann, Detlef; Henning, Torsten; Klar, Peter; Meyer, Bruno K. [I. Physikalisches Institut, JLU Giessen (Germany)

    2010-07-01

    Cu{sub 2}O is one of the rare intrinsically p-type conducting semiconductors, in addition the energy of its band gap is in the visible spectral range. Thus it is considered to be a promising material for thin-film-solar cell applications. Metallic and ceramic sputtering processes can be used for the thin-film deposition. Depending on the oxygen partial-pressure, the stoichiometric properties of Cu{sub x}O are adjustable from x=2 to x=1. The electrical properties change considerably depending on the copper-to-oxygen-ratio. It is commonly assumed that copper-vacancies are the dominant intrinsic acceptors in Cu{sub 2}O, thus high carrier concentrations come along with a reduced crystalline quality. Using nitrogen-gas for doping allows carrier concentrations of p=10{sup 15}-10{sup 17} cm{sup -3} without significantly reducing the structural properties of the Cu{sub 2}O-thin-films. By using ZnO as n-type semiconductor, first p/n hetero-junctions were realized. The mesa etched structures show rectifying behaviour and its electrical properties are discussed on the conference.

  17. Concept formation: a supportive process for early career nurses.

    Science.gov (United States)

    Thornley, Tracey; West, Sandra

    2010-09-01

    Individuals come to understand abstract constructs such as that of the 'expert' through the formation of concepts. Time and repeated opportunity for observation to support the generalisation and abstraction of the developing concept are essential if the concept is to form successfully. Development of an effective concept of the 'expert nurse' is critical for early career nurses who are attempting to integrate theory, values and beliefs as they develop their clinical practice. This study explores the use of a concept development framework in a grounded theory study of the 'expert nurse'. Qualitative. Using grounded theory methods for data collection and analysis, semi-structured interviews were conducted with registered nurses. The participants were asked to describe their concept of the 'expert nurse' and to discuss their experience of developing this. Participants reported forming their concept of the 'expert nurse', after multiple opportunities to engage with nurses identified as 'expert'. This identification did not necessarily relate to the designated position of the 'expert nurse' or assigned mentors. When the early career nurse does not successfully form a concept of the 'expert nurse', difficulties in personal and professional development including skill/knowledge development may arise. To underpin development of their clinical practice effectively, early career nurses need to be provided with opportunities that facilitate the purposive formation of their own concept of the 'expert nurse'. Formation of this concept is not well supported by the common practice of assigning mentors. Early career nurses must be provided with the time and the opportunity to individually develop and refine their concept of the 'expert nurse'. To achieve this, strategies including providing opportunities to engage with expert nurses and discussion of the process of concept formation and its place in underpinning personal judgments may be of assistance. © 2010 Blackwell Publishing

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

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, Javiera; Mayer, Lucio; Carollo, Marcella [Institute for Astronomy, ETH Zuerich, Wolgang-Pauli-Strasse 27, 8093 Zurich (Switzerland); Madau, Piero [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

    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.

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

    Science.gov (United States)

    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. Copyright © 2014 John Wiley & Sons, Ltd.

  20. Fuzzy social choice models explaining the government formation process

    CERN Document Server

    C Casey, Peter; A Goodman, Carly; Pook, Kelly Nelson; N Mordeson, John; J Wierman, Mark; D Clark, Terry

    2014-01-01

    This book explores the extent to which fuzzy set logic can overcome some of the shortcomings of public choice theory, particularly its inability to provide adequate predictive power in empirical studies. Especially in the case of social preferences, public choice theory has failed to produce the set of alternatives from which collective choices are made.  The book presents empirical findings achieved by the authors in their efforts to predict the outcome of government formation processes in European parliamentary and semi-presidential systems.  Using data from the Comparative Manifesto Project (CMP), the authors propose a new approach that reinterprets error in the coding of CMP data as ambiguity in the actual political positions of parties on the policy dimensions being coded. The range of this error establishes parties’ fuzzy preferences. The set of possible outcomes in the process of government formation is then calculated on the basis of both the fuzzy Pareto set and the fuzzy maximal set, and the pre...

  1. Formats

    Directory of Open Access Journals (Sweden)

    Gehmann, Ulrich

    2012-03-01

    Full Text Available In the following, a new conceptual framework for investigating nowadays’ “technical” phenomena shall be introduced, that of formats. The thesis is that processes of formatting account for our recent conditions of life, and will do so in the very next future. It are processes whose foundations have been laid in modernity and which will further unfold for the time being. These processes are embedded in the format of the value chain, a circumstance making them resilient to change. In addition, they are resilient in themselves since forming interconnected systems of reciprocal causal circuits.Which leads to an overall situation that our entire “Lebenswelt” became formatted to an extent we don’t fully realize, even influencing our very percep-tion of it.

  2. Radiological audit of remedial action activities at the processing site, transfer site, and Cheney disposal site Grand Junction, Colorado: Audit date, August 9--11, 1993. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    The Uranium Mill Tailing Remedial Action (UMTRA) Project`s Technical Assistance Contractor (TAC) performed a radiological audit of the Remedial Action Contractor (RAC), MK-Ferguson and CWM Federal Environmental Services, Inc., at the processing site, transfer site, and Cheney disposal site in Grand Junction, Colorado. Jim Hylko and Bill James of the TAC conducted this audit August 9 through 11, 1993. Bob Cornish and Frank Bosiljevec represented the US Department of Energy (DOE). This report presents one programmatic finding, eleven site-specific observations, one good practice, and four programmatic observations.

  3. Laser-assisted controlled in-diffusion processes for preparation of optical waveguides and ultrashallow semiconductor junctions

    Science.gov (United States)

    Dinescu, Maria; Chitica, N.; Lita, Adriana; Pantelica, D.; Bucur, B.; Ferrari, A.; Maiello, Gabriella; Bertolotti, Mario; Michailova, Galina; Gerardi, C.; Giorgi, Rossella; Dekonimos-Makris, T.; Montecchi, Marco

    1995-03-01

    We present new results in the laser doping of two materials of major interest for applications: LiNbO3 and Si. In both cases a solid dopant source was used. Using a free running ruby laser, we have doped single crystalline lithium niobate with Ti down to 1.5 micrometers . A step- like Ti profile was determined by Rutherford BAckscattering Spectrometry. Irradiating with a cw CO2 laser Si wafers coated with a P-containing paste, n-p junctions were obtained.

  4. TEACHER ROLE IN FORMATION POLITENESS OF STUDENT LEARNING PROCESS

    Directory of Open Access Journals (Sweden)

    Wahyuni Oktavia

    2016-09-01

    Full Text Available Language as a communication tool has an important role in human interaction. Language can be used to convey ideas, ideas, feelings, desires, and so forth to others. To be able to communicate well certainly should be able to adjust the language used. One of the main functions of communication is to maintain the continuity of the relationship between the narrator and hearer. Language is an important pillar in the formation of character, in addition to religious education and moral education. In education, teachers must have pedagogical, professional, personal, and social. Teachers who have a good competence speech acts certainly have a good and well mannered to students. In the learning process, teachers and students communicate in give and receive course materials. The learning process is certainly not only provides knowledge alone, but give the values of character to students. In this case, the teacher must have a principle that must be controlled properly, correctly and precisely. Thus, teachers are expected to master the communication and understanding the principles of politeness in speaking well and correctly. The goal is a description of a form of politeness in the learning process. This research is a descriptive study which seeks to describe a form of politeness in the learning process. Data collection method used is the method refer to the data collection techniques are 1 recording technique using a tape recorder, and 2 technical note on the data card. Furthermore, methods of data analysis using pragmatic frontier.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  6. Driving Mechanism of Jets and Outflows in Star Formation Process

    CERN Document Server

    Machida, Masahiro N; Matsumoto, Tomoaki

    2007-01-01

    The driving mechanism of jets and outflows in star formation process is studied using resistive MHD nested grid simulations. We calculated cloud evolution from the molecular cloud core to the stellar core. In the collapsing cloud core, we found two distinct flows: Low-velocity flows (sim 5 km/s) with a wide opening angle, driven from the adiabatic core, and high-velocity flows (sim 30 km/s) with good collimation, driven from the protostar. High-velocity flows are enclosed by low-velocity flows after protostar formation. The difference in the degree of collimation between the two flows is caused by the strength of the magnetic field and configuration of the magnetic field lines. The magnetic field around an adiabatic core is strong and has an hourglass configuration; therefore, flows from the adiabatic core are driven mainly by the magnetocentrifugal mechanism and guided by the hourglass-like field lines. In contrast, the magnetic field around the protostar is weak and has a straight configuration owing to Ohm...

  7. Dynamically Multivalued Self-Organisation and Probabilistic Structure Formation Processes

    CERN Document Server

    Kirilyuk, A P

    2004-01-01

    The unreduced, universally nonperturbative analysis of arbitrary many-body interaction process reveals the irreducible, purely dynamic source of randomness. It leads to the universal definition of real system complexity (physics/9806002), where the internally chaotic self-organisation emerges as a limiting case of complex interaction dynamics (physics/0211071). It extends also the concept of "self-organised criticality" and corresponds to formation of distinct enough (but always internally chaotic) structures occurring if the system is far from characteristic frequency resonances. Transition to the opposite limiting regime of multivalued interaction dynamics, that of uniform (global) chaos, takes place around the main frequency resonance(s), which provides the absolutely universal criterion of global chaos onset, applicable to any kind of system, as well as the new, extended interpretation of the phenomenon of resonance itself. As a result, one obtains the causally complete description of world structure emer...

  8. Behavior of Zirconium Sponge Formation in the Kroll Process

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Yong-Ik; Sohn, Ho-Sang [Kyungpook National University, Daegu (Korea, Republic of); Jung, Jae-Young [Research Institute of Industrial Science and Technology(RIST), Pohang (Korea, Republic of)

    2014-04-15

    The Kroll process of magnesium reduction of titanium tetrachloride is used for mass production of zirconium sponges. This study is conducted in a laboratory-scale reactor in order to develop a better understanding of the zirconium sponge formation mechanism in the Kroll reactor with respect to the reaction degrees and reaction time. The MgCl{sub 2} produced during the initial stage of the reaction does not sink into the molten magnesium, but remains on the surface of the molten magnesium. As a result, ZrCl{sub 4} feed reacts with the Mg exposed on the edge of the molten MgCl{sub 2} in the crucible. Therefore, the Zr particles produced at the later reaction stage descend into the molten magnesium at the crucible wall.

  9. Zirconium hydride formation in Hanford production reactor process tubes

    Energy Technology Data Exchange (ETDEWEB)

    Winegardner, W.K.; Griggs, B.

    1967-12-01

    Examination of Zircaloy-2 process tubes from Hanford Production Reactors has revealed extensive zirconium hydride formation. In general, attack is limited to the downstream portions of tubes where aluminum spacers are located. Most of the hydride platelets are contained in a case or layer on the inner surface of the tube. It is not unusual to find cases 0.004 to 0.005 in. thick. Analyses of the 0.037 in. wall tubes with such cases intact often reveal hydrogen concentrations greater than 1000 ppM. Investigation indicates that the hydriding is the result of galvanic contact between aluminum and Zircaloy-2. The galvanic couple (contact between dissimilar metals in the presence of reactor cooling water which serves as the electrolyte) results in the cathodic charging of hydrogen into the Zircaloy.

  10. Cluster B personality symptoms in persons at genetic risk for schizophrenia are associated with social competence and activation of the right temporo-parietal junction during emotion processing.

    Science.gov (United States)

    Goldschmidt, Micaela Giuliana; Villarreal, Mirta Fabiana; de Achával, Delfina; Drucaroff, Lucas Javier; Costanzo, Elsa Yolanda; Castro, Mariana Nair; Pahissa, Jaime; Camprodon, Joan; Nemeroff, Charles; Guinjoan, Salvador Martín

    2014-01-30

    Personality disorders are common in nonpsychotic siblings of patients with schizophrenia, and some personality traits in this group may be associated with an increased risk for full-blown psychosis. We sought to establish if faulty right-hemisphere activation induced by social cognitive tasks, as previously described in patients with schizophrenia, is associated with specific personality symptoms in their unaffected siblings. We observed that cluster B personality symptoms in this group were inversely related to activation in the right temporo parietal junction (rTPJ, a structure critical in social cognitive processing) in response to a basic emotion processing task and also to social competence, whereas in contrast to our initial hypothesis, cluster A traits were not associated with right hemisphere activation during emotion processing or with social competence. These findings suggest the existence of clinical traits in at-risk individuals which share a common neurobiological substrate with schizophrenia, in regards to social performance.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Shh and Gli3 regulate formation of the telencephalic-diencephalic junction and suppress an isthmus-like signaling source in the forebrain.

    Science.gov (United States)

    Rash, Brian G; Grove, Elizabeth A

    2011-11-15

    In human holoprosencephaly (HPE), the forebrain does not separate fully into two hemispheres. Further, the border between the telencephalon and diencephalon, the telencephalic/diencephalic junction (TDJ), is often indistinct, and the ventricular system can be blocked at the third ventricle, creating a forebrain 'holosphere'. Mice deficient in Sonic Hedgehog (Shh) have previously been described to show HPE and associated cyclopia. Here we report that the third ventricle is blocked in Shh null mutants, similar to human HPE, and that characteristic telencephalic and diencephalic signaling centers, the cortical hem and zona limitans intrathalamica (ZLI), are merged, obliterating the TDJ. The resulting forebrain holosphere comprises Foxg1-positive telencephalic- and Foxg1-negative diencephalic territories. Loss of one functional copy of Gli3 in Shh nulls rescues ventricular collapse and substantially restores the TDJ. Characteristic regional gene expression patterns are rescued on the telencephalic side of the TDJ but not in the diencephalon. Further analysis of compound Shh;Gli3 mutants revealed an unexpected type of signaling center deregulation. In Shh;Gli3 mutants, adjacent rings of Fgf8 and Wnt3a expression are induced in the diencephalon at the ZLI, reminiscent of the Fgf8/Wnt1-expressing isthmic organizer. Neither Shh nor Gli3 single mutants show this forebrain double ring of Fgf/Wnt expression; thus both Shh and Gli3 are independently required to suppress it. Adjacent tissue is not respecified to a midbrain/hindbrain fate, but shows overgrowth, consistent with ectopic mitogen expression. Our observations indicate that the separation of the telencephalon and diencephalon depends on interactions between Shh and Gli3, and, moreover, demonstrate that both Shh and Gli3 suppress a potential Fgf/Wnt signaling source in the forebrain. That optional signaling centers are actively repressed in normal development is a striking new insight into the processes of vertebrate

  13. Microstructural characterization of CIGS formation using different selenization processes

    Science.gov (United States)

    Liao, Kuang-Hsiang; Su, Cherng-Yuh; Ding, Yu-Ting; Koo, Horng-Show

    2013-04-01

    Cu(In1-x,Gax)Se2 (CIGS) thin films were prepared by the sputtering of CuInGa precursors followed by chalcogenization via an isothermal (one-zone) selenization and a two-zone selenization. The effects of two selenization processes on the microstructural characteristics of CIGS films were also studied. In addition, we varied the selenization temperature for the two processes between 450 °C and 580 °C to investigate this effect on the microstructural characteristics and compositions of the CIGS films. The results indicated that the CIGS thin films formed using isothermal selenization had dense grain structure whose grains increased in size after an increase in the selenized temperature. However, the Se/(Cu + In + Ga) ratios of the films indicated that Se was distributed non-uniformly in the films, with Se-saturated CIGS present on the front side of the films and incompletely formed CIGS on the back side. In addition, it was noticed that Ga accumulated in large amounts in the films, depending on the chemical affinity between In and Se. Comparatively, the films prepared using two-zone selenization showed Ga accumulation that was only slightly greater than that in the films fabricated by the isothermal selenization. It is likely that the slow selenization of the CIG precursors reduced the extent of Ga accumulation because of the presence of Se in insufficient amounts. However, the presence of Se in insufficient amounts may also format the CIGS thin films with a porous microstructure.

  14. Subglacial till formation: Microscale processes within the subglacial shear zone

    Science.gov (United States)

    Hart, Jane K.

    2017-08-01

    This was a study of subglacial deformation till genesis from a modern temperate glacier, at Skálafellsjökull, Iceland. Detailed microscale properties of till samples (from Scanning Electron Microscope [SEM] and thin section analysis) were examined from a glacial site with in situ subglacial process monitoring and an exposed subglacial surface in the foreland. Two lithofacies were examined, a grey sandy till derived from the ash and basalt, and a silty reddish brown till derived from oxidized paleosols and/or tephra layers. These also represented a clay-content continuum from low (0.3%) to high (22.3%). The evolution from debris to subglacial till was investigated. This included a reduction in grain-size (21% for grey lithology, 13% reddish brown lithology), and reduction in rounding (RA) (32% for the grey lithology, 26% for the reddish brown lithology), and the quantification and analysis of the different grain erosion/comminution processes in the resultant till. It was shown that the microstructures within a till were dependent on shear strain and glaciological conditions (deformation history). The low clay content tills were dominated by linear structures (lineations and boudins, and anisotropic microfabric) whilst the higher clay content tills were dominated by rotational structures (turbates and plaster, and isotropic microfabric). These results are important in our understanding of the formation of both modern and Quaternary tills and informs our reconstruction of past glacial dynamics.

  15. Analysis and evalaution in the production process and equipment area of the low-cost solar array project. [including modifying gaseous diffusion and using ion implantation

    Science.gov (United States)

    Goldman, H.; Wolf, M.

    1979-01-01

    The manufacturing methods for photovoltaic solar energy utilization are assessed. Economic and technical data on the current front junction formation processes of gaseous diffusion and ion implantation are presented. Future proposals, including modifying gaseous diffusion and using ion implantation, to decrease the cost of junction formation are studied. Technology developments in current processes and an economic evaluation of the processes are included.

  16. SAMMate: a GUI tool for processing short read alignments in SAM/BAM format

    Directory of Open Access Journals (Sweden)

    Flemington Erik

    2011-01-01

    Full Text Available Abstract Background Next Generation Sequencing (NGS technology generates tens of millions of short reads for each DNA/RNA sample. A key step in NGS data analysis is the short read alignment of the generated sequences to a reference genome. Although storing alignment information in the Sequence Alignment/Map (SAM or Binary SAM (BAM format is now standard, biomedical researchers still have difficulty accessing this information. Results We have developed a Graphical User Interface (GUI software tool named SAMMate. SAMMate allows biomedical researchers to quickly process SAM/BAM files and is compatible with both single-end and paired-end sequencing technologies. SAMMate also automates some standard procedures in DNA-seq and RNA-seq data analysis. Using either standard or customized annotation files, SAMMate allows users to accurately calculate the short read coverage of genomic intervals. In particular, for RNA-seq data SAMMate can accurately calculate the gene expression abundance scores for customized genomic intervals using short reads originating from both exons and exon-exon junctions. Furthermore, SAMMate can quickly calculate a whole-genome signal map at base-wise resolution allowing researchers to solve an array of bioinformatics problems. Finally, SAMMate can export both a wiggle file for alignment visualization in the UCSC genome browser and an alignment statistics report. The biological impact of these features is demonstrated via several case studies that predict miRNA targets using short read alignment information files. Conclusions With just a few mouse clicks, SAMMate will provide biomedical researchers easy access to important alignment information stored in SAM/BAM files. Our software is constantly updated and will greatly facilitate the downstream analysis of NGS data. Both the source code and the GUI executable are freely available under the GNU General Public License at http://sammate.sourceforge.net.

  17. Transcriptional mechanisms coordinating tight junction assembly during epithelial differentiation.

    Science.gov (United States)

    Boivin, Felix J; Schmidt-Ott, Kai M

    2017-06-01

    Epithelial tissues form a selective barrier via direct cell-cell interactions to separate and establish concentration gradients between the different compartments of the body. Proper function and formation of this barrier rely on the establishment of distinct intercellular junction complexes. These complexes include tight junctions, adherens junctions, desmosomes, and gap junctions. The tight junction is by far the most diverse junctional complex in the epithelial barrier. Its composition varies greatly across different epithelial tissues to confer various barrier properties. Thus, epithelial cells rely on tightly regulated transcriptional mechanisms to ensure proper formation of the epithelial barrier and to achieve tight junction diversity. Here, we review different transcriptional mechanisms utilized during embryogenesis and disease development to promote tight junction assembly and maintenance of intercellular barrier integrity. We focus particularly on the Grainyhead-like transcription factors and ligand-activated nuclear hormone receptors, two central families of proteins in epithelialization. © 2017 New York Academy of Sciences.

  18. Pseudobulge Formation as a Dynamical Rather than a Secular Process

    CERN Document Server

    Guedes, Javiera; Carollo, Marcella; Madau, Piero

    2012-01-01

    We investigate the formation and evolution of the pseudobulge in "Eris", a high-resolution N-body + smoothed particle hydrodynamics (SPH) cosmological simulation that successfully reproduces a Milky Way-like massive late-type spiral in a cold dark matter (LCDM) universe. At the present epoch, Eris has a virial mass Mvir=8x10^11 Msun, a photometric stellar mass M*=3.2x10^10 Msun, 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 evolves from a stellar bar that formed at high redshift, was destroyed by minor mergers at z~3, reformed shortly after, and weakened again ...

  19. FORMATION PROCESS AND HISTORICAL FUNCTIONS OF OLD AKIHA ROAD

    Science.gov (United States)

    Nakane, Yoji; Okuda, Masao; Kani, Yukihiko; Hayakawa, Kiyoshi; Matsui, Tamotsu

    An object of this study is the old Akiha road located along the southern parts of the Akaishi Mountains in Sizuoka Prefecture. The old Akiha road between Hamamatsu city in Enshu and Iida city in Shinshu had been utilized by people for the purposes of making a pilgrimage, megalithic faith, transporting obsidian since the primitive age, practicing the mountaineering asceticism, operating the military activities in the warlike age, transporting salt from coastal area to mountainous area and so on. Through the investigation of literature, site reconnaissance and hearing, the formation process and the historical functions of the old Akiha road were studied, including the situation in medieval times or before. As the results, it was elucidated that the oldest road between two cities had located over the Hyoukoshi Pass, the road routes had the lowering trend from mountainside to riverside, and the historical functions of old Akiha road were the passage for transportation of various kinds of goods and human being, faith and culture.

  20. Internal social processes of discipline formation: the case of kinanthropometry.

    Science.gov (United States)

    Vangrunderbeek, Hans; Claessens, Albrecht L; Delheye, Pascal

    2013-01-01

    In 1972, the term 'kinanthropometry', derived from the Greek words 'kinein' (to move), 'anthropos' (human) and 'metrein' (to measure), was launched in the international, Francophone journal Kinanthropologie by the Canadian William Ross and the Belgians, Marcel Hebbelinck, Bart Van Gheluwe and Marie-Louise Lemmens. The authors defined this neologism as 'the scientific discipline for the study of the size, shape, proportion, scope and composition of the human being and its gross motor functions'. Presenting a theoretical framework for the analysis of the internal social processes of discipline formation - derived from the social history-of-science tradition - this article critically examines whether kinanthropometry was indeed promoted and developed by its community members as a scientific discipline. Therefore, the focus will be on its conceptualisation and positioning within the field of kinanthropology/kinesiology and on its development by a scholarly association, i.e. the International Working Group on Kinanthropometry (IWGK). The strong emphasis of the kinanthropometry community on the standardisation of measurement techniques and its practical and professional application hampered its disciplinary development. Findings of this study could serve as a basis for future 'fundamental' investigations addressing questions of disciplinary development within the field(s) of physical education, kinesiology and sport science(s).

  1. Cogeneration systems and processes for treating hydrocarbon containing formations

    Science.gov (United States)

    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.

  2. Solution processed, hybrid 2D/3D MoS2/Si heterostructures with superior junction characteristics.

    Science.gov (United States)

    Mukherjee, Subhrajit; Biswas, Souvik; Das, Soumen; Ray, Samit K

    2017-02-03

    We report a theoretical and experimental investigation of the hybrid heterostructure interfaces between atomically thin MoS2 nanocrystals (NCs) on Si platform for their potential applications towards next generation electrical and optical devices. Mie theory based numerical analysis and COMSOL simulations based on finite element method (FEM) have been utilized to study the optical absorption characteristics and light matter interactions in variable sized MoS2 NCs. The size dependent absorption characteristics and the enhancement of electric field of the heterojunction in the UV-visible spectral range agree well with the experimental results. A lithography-free, wafer scale, 2D materials on a 3D substrate hybrid vertical heterostructure has been fabricated using colloidal n-MoS2 NCs on p-Si. The fabricated p-n heterojunction exhibited excellent junction characteristics with a high rectification ratio suitable for voltage clipper and rectifier applications. The current-voltage characteristics of the devices under illumination have been performed in the temperature range of 10-300 K. The device exhibits a high photo-to-dark current ratio of ~3 x 103 and a responsivity comparable to a commercial Si photodetector. The excellent heterojunction characteristics demonstrate the great potential of MoS2 NCs based hybrid electronic and optoelectronic devices in near future.

  3. Josephson junctions with ferromagnetic interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Wild, Georg Hermann

    2012-03-04

    We report on the fabrication of superconductor/insulator/ferromagnetic metal/superconductor (Nb/AlO{sub x}/Pd{sub 0.82}Ni{sub 0.18}/Nb) Josephson junctions (SIFS JJs) with high critical current densities, large normal resistance times area products, and high quality factors. For these junctions, a transition from 0- to {pi}-coupling is observed for a thickness d{sub F}=6 nm of the ferromagnetic Pd{sub 0.82}Ni{sub 0.18} interlayer. The magnetic field dependence of the critical current of the junctions demonstrates good spatial homogeneity of the tunneling barrier and ferromagnetic interlayer. Magnetic characterization shows that the Pd{sub 0.82}Ni{sub 0.18} has an out-of-plane anisotropy and large saturation magnetization indicating negligible dead layers at the interfaces. A careful analysis of Fiske modes up to about 400 GHz provides valuable information on the junction quality factor and the relevant damping mechanisms. Whereas losses due to quasiparticle tunneling dominate at low frequencies, at high frequencies the damping is explained by the finite surface resistance of the junction electrodes. High quality factors of up to 30 around 200 GHz have been achieved. They allow to study the junction dynamics, in particular the switching probability from the zero-voltage into the voltage state with and without microwave irradiation. The experiments with microwave irradiation are well explained within semi-classical models and numerical simulations. In contrast, at mK temperature the switching dynamics without applied microwaves clearly shows secondary quantum effects. Here, we could observe for the first time macroscopic quantum tunneling in Josephson junctions with a ferromagnetic interlayer. This observation excludes fluctuations of the critical current as a consequence of an unstable magnetic domain structure of the ferromagnetic interlayer and affirms the suitability of SIFS Josephson junctions for quantum information processing.

  4. An important impact of the molecule-electrode couplings asymmetry on the efficiency of bias-driven redox processes in molecular junctions

    CERN Document Server

    Baldea, Ioan

    2015-01-01

    Two recent experimental (Li, J.~\\emphj{et al}, \\emph{Proc.\\ Natl.\\ Acad.\\ Sci.\\ U.~S.~A.} {\\bf 2014}, 111, 1282-1287) and theoretical studies (B\\^aldea, I, \\emph{Phys.\\ Chem.\\ Chem.\\ Phys.}\\ {\\bf 2014}, 16, 25942-25949) have addressed the problem of tuning molecular charge and vibrational properties of single molecules embedded in nanojunctions. These are molecular characteristics escaping so far to an efficient experimental control in broad ranges. Here, we present a general argument demonstrating why, out of various experimental platforms possible, those wherein active molecules are asymmetrically coupled to electrodes are to be preferred to those symmetrically coupled for achieving a(n almost) complete redox process, and why electrochemical environment has advantages over "dry" setups. This study aims at helping to nanofabricate molecular junctions using the most appropriate platforms enabling the broadest possible bias-driven control of the redox state and vibrational modes of single molecules linked to e...

  5. Study the Formation Process of Cuboid Microprotrusion by Glass Molding Process

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2017-02-01

    Full Text Available This paper investigates the formation process of a typical microstructure in the glass microfluidic chip, i.e., cuboid microprotrusion, by the soda-lime glass molding process (GMP. The finite element models on the platform Abaqus/Standard were established for simulating the glass molding process. The glass viscoelasticity at pressing temperature was described by the General Maxwell model. The influence of the temperature, aspect ratio and side wall angle on the replication ratio was investigated, and the corresponding predicted molded profiles were demonstrated as well. The established simulation model was verified by experimental results eventually. It could provide a fundamental experience for optimizing glass molding parameters to fabricate microstructures on glass chips.

  6. Marriage formation as a process intermediary between migration and childbearing

    Directory of Open Access Journals (Sweden)

    Lesia Nedoluzhko

    2008-06-01

    Full Text Available In studies of differences in fertility between migrants and non-migrants, marriage interferes because migration can be motivated by an impending marriage or can entail entry into a marriage market with new opportunities. One would therefore expect elevated fertility after migration, although a competing theory states that on the contrary fertility ought to be reduced in the time around the move because migration temporarily disturbs the life of the migrant. In any case marriage appears as a process that is intermediary between migration and childbearing. To handle such issues it pays to have a technique that allows the analyst to separate any disruptive effects of migration from any boosting effects of marriage in studies of childbearing. The purposes of the present paper are (i to remind us that such a technique is available, in fact is straightforward, and (ii to apply the technique to further analyze a set of data on migration and first-time parenthood in Kyrgyzstan recently used by the second author and Gunnar Andersson. The technique has the neat feature that it allows us to operate with several "clocks" at the same time. In the analysis of first births we keep track of time since migration (for migrants and time since marriage formation (for the married beside the respondent's age (for women at childbearing ages; in other connections there may be more clocks. For such analyses we make use of a flexible graphical housekeeping device that allows the analyst to keep track of a feature like whether migration occurs before or after marriage, or at the same time. This is a half-century-old flow chart of statuses and transitions and is not much more complex than the famous Lexis diagram, which originated with Gustav Zeuner, as we now know. These reflexions were first presented at a symposium dedicated to Professor Zeuner.

  7. The development of the myotendinous junction. A review.

    Science.gov (United States)

    Charvet, Benjamin; Ruggiero, Florence; Le Guellec, Dominique

    2012-04-01

    The myotendinous junction (MTJ) is a complex specialized region located at the muscle-tendon interface that represents the primary site of force transmission. Despite their different embryologic origins, muscle and tendon morphogenesis occurs in close spatial and temporal association. After muscle attachment, muscle and tendon constitute a dynamic and functional integrated unit that transduces muscle contraction force to the skeletal system. We review here the current understanding of MTJ formation describing changes during morphogenesis and focusing on the crosstalk between muscle and tendon cells that leads to the development of a functional MTJ. Molecules involved in the formation of the linkage, both at the tendon side and at the muscle side of the junction are described. Much of this knowledge comes from studies using different animal models such as mice, zebrafish and Drosophila where powerful methods for in vivo imaging and genetic manipulations can be used to enlighten this developmental process.

  8. Characterization of pure boron depositions integrated in silicon diodes for nanometer-deep junction applications

    NARCIS (Netherlands)

    Sarubbi, F.

    2010-01-01

    Doping technologies for formation of ultrashallow and highly-doped p+ junctions are continuously demanded to face the challenges in front-end processing that have emerged due to the aggressive downscaling of vertical dimensions for future semiconductor devices. As an alternative to implantations, cu

  9. Characterization of pure boron depositions integrated in silicon diodes for nanometer-deep junction applications

    NARCIS (Netherlands)

    Sarubbi, F.

    2010-01-01

    Doping technologies for formation of ultrashallow and highly-doped p+ junctions are continuously demanded to face the challenges in front-end processing that have emerged due to the aggressive downscaling of vertical dimensions for future semiconductor devices. As an alternative to implantations, cu

  10. Rapid neutron capture process in supernovae and chemical element formation

    NARCIS (Netherlands)

    Baruah, Rulee; Duorah, Kalpana; Duorah, H. L.

    2009-01-01

    The rapid neutron capture process (r-process) is one of the major nucleosynthesis processes responsible for the synthesis of heavy nuclei beyond iron. Isotopes beyond Fe are most exclusively formed in neutron capture processes and more heavier ones are produced by the r-process. Approximately half o

  11. HFC-134a refrigerant gas hydrate formation process and RIN model

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this paper, the macroscopic visualization experiments of HFC-134a refrigerant gas hydrate formation are investigated. According to the macroscopic photos and Mori's microscopic photos of HFC-134a hydrate formation process, the mechanism of gas hydrate formation is analyzed.A random inducement nucleation model is presented to describe the hydrate formation process. The factors affecting the fractal growth dimension in the model, such as step,branch increment and angle, are discussed.``

  12. The Ly6 protein coiled is required for septate junction and blood brain barrier organisation in Drosophila.

    Directory of Open Access Journals (Sweden)

    Assia Hijazi

    Full Text Available BACKGROUND: Genetic analysis of the Drosophila septate junctions has greatly contributed to our understanding of the mechanisms controlling the assembly of these adhesion structures, which bear strong similarities with the vertebrate tight junctions and the paranodal septate junctions. These adhesion complexes share conserved molecular components and have a common function: the formation of paracellular barriers restraining the diffusion of solutes through epithelial and glial envelopes. METHODOLOGY/PRINCIPAL FINDINGS: In this work we characterise the function of the Drosophila cold gene, that codes for a protein belonging to the Ly6 superfamily of extracellular ligands. Analysis of cold mutants shows that this gene is specifically required for the organisation of the septate junctions in epithelial tissues and in the nervous system, where its contribution is essential for the maintenance of the blood-brain barrier. We show that cold acts in a cell autonomous way, and we present evidence indicating that this protein could act as a septate junction component. CONCLUSION/SIGNIFICANCE: We discuss the specific roles of cold and three other Drosophila members of the Ly6 superfamily that have been shown to participate in a non-redundant way in the process of septate junction assembly. We propose that vertebrate Ly6 proteins could fulfill analogous roles in tight junctions and/or paranodal septate junctions.

  13. Transport processes and reduction of IcRn product in YBaCuO/PrBaCuO/YBaCuO ramp-type Josephson junctions

    NARCIS (Netherlands)

    Boguslavskij, Y.M.; Gao, J.; Rijnders, A.J.H.M.; Terpstra, D.; Gerritsma, G.J.; Rogalla, H.

    1993-01-01

    The mechanisms of current passage and the causes of IcRn (critical-current normal-resistance) product reduction of YBCO/PBCO/YBCO ramp-type junctions are analyzed. At PBCO (PrBa2Cu3Ox ) barrier thicknesses L=8-20 nm the junction characteristics are determined by the thickness of the PBCO barrier and

  14. Zurek–Kibble Symmetry Breaking Process in Superconducting Rings; Spontaneous Fluxon Formation in Annular Josephson Tunnel Junctions

    DEFF Research Database (Denmark)

    Aarøe, Morten; Monaco, Roberto; Dmitriev, P

    2007-01-01

    -superconducting transition. A trapped fluxon unambiguously is detected as a zero-field step in the DC I-V characteristic. Experimentally we plot the fluxon trapping probability versus the quench rate, varied over 4 decades. An allometric scaling behavior is found. By fitting to the theoretical curve we get sigma sime 0.......5 for the ZK critical scaling exponent sigma, which does not agree with an earlier theoretical prediction of sigma = 0.25. A novel theory based on the proximity effect leading to sigma = 0.50 has been proposed. The dependence of the gap voltage on temperature is measured and used for precise monitoring...

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

    Science.gov (United States)

    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.

  16. Mechanical behaviour and formation process of silkworm silk gut.

    Science.gov (United States)

    Cenis, José L; Madurga, Rodrigo; Aznar-Cervantes, Salvador D; Lozano-Pérez, A Abel; Marí-Buyé, Núria; Meseguer-Olmo, Luis; Plaza, Gustavo R; Guinea, Gustavo V; Elices, Manuel; Del Pozo, Francisco; Pérez-Rigueiro, José

    2015-12-14

    High performance silk fibers were produced directly from the silk glands of silkworms (Bombyx mori) following an alternative route to natural spinning. This route is based on a traditional procedure that consists of soaking the silk glands in a vinegar solution and stretching them by hand leading to the so called silkworm guts. Here we present, to the authors' best knowledge, the first comprehensive study on the formation, properties and microstructure of silkworm gut fibers. Comparison of the tensile properties and microstructural organization of the silkworm guts with those of naturally spun fibers allows gain of a deeper insight into the mechanisms that lead to the formation of the fiber, as well as the relationship between the microstructure and properties of these materials. In this regard, it is proved that an acidic environment and subsequent application of tensile stress in the range of 1000 kPa are sufficient conditions for the formation of a silk fiber.

  17. Shewanella putrefaciens adhesion and biofilm formation on food processing surfaces

    DEFF Research Database (Denmark)

    Bagge, Dorthe; Hjelm, M.; Johansen, C.

    2001-01-01

    Laboratory model systems were developed for studying Shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. S. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. S. putrefaciens bacteria suspended...... (modified Robbins device) (reaching 10(2) CFU/cm(2)) than in a batch system (reaching 10(7) CFU/cm(2)), and maximum numbers were reached after 24 h. When nutrients were supplied, S. putrefaciens grew in biofilms with layers of bacteria. The rate of biofilm formation and the thickness of the film were...

  18. Feedback Processes [in Massive Star Formation]: A Theoretical Perspective

    CERN Document Server

    Mac Low, Mordecai-Mark

    2007-01-01

    I review the evidence for the importance of feedback from massive stars at small and large scales. The feedback mechanisms include accretion luminosity, ionizing radiation, collimated outflows, and stellar winds. The good news is that feedback doesn't entirely prevent the formation of massive stars, while the bad news is that we don't know what does limit their masses. Feedback from massive stars also influences their surroundings. I argue that this does not produce a triggering efficiency above unity, nor does it prevent lots of prompt star formation in GMCs, though it may preserve massive remnants of the clouds for many dynamical times.

  19. Pyruvate formate lyase acts as a formate supplier for metabolic processes during anaerobiosis in Staphylococcus aureus.

    Science.gov (United States)

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

    2011-02-01

    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.

  20. Molecular electronic junction transport

    DEFF Research Database (Denmark)

    Solomon, Gemma C.; Herrmann, Carmen; Ratner, Mark

    2012-01-01

    Whenasinglemolecule,oracollectionofmolecules,isplacedbetween two electrodes and voltage is applied, one has a molecular transport junction. We discuss such junctions, their properties, their description, and some of their applications. The discussion is qualitative rather than quantitative, and f...

  1. Defining Sustainable Universities Following Public Opinion Formation Process

    Science.gov (United States)

    Zaptcioglu Celikdemir, Deniz; Gunay, Gonca; Katrinli, Alev; Penbek Alpbaz, Sebnem

    2017-01-01

    Purpose: The purpose of this paper is to define the sustainable university in Turkey, by considering perspectives of various stakeholders such as experts, intellectual, public, political parties and media using public opinion formation analysis. The paper aims to re-define the "sustainable university" with all dimensions including…

  2. Comparison of boron diffusion in silicon during shallow p{sup +}/n junction formation by non-melt excimer and green laser annealing

    Energy Technology Data Exchange (ETDEWEB)

    Aid, Siti Rahmah; Matsumoto, Satoru [Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama, Kanagawa 223-8522 (Japan); Fuse, Genshu [SEN Corporation, SBS Tower 9F, 4-10-1 Yoga, Setagaya-ku, Tokyo 158-0097 (Japan); Sakuragi, Susumu [Sumitomo Heavy Industries Ltd., 19 Natsushima-cho, Yokosuka, Kanagawa 237-8555 (Japan)

    2011-12-15

    The combination of Ge pre-amorphization implantation, low-energy boron implantation, and non-melt laser annealing is a promising method for forming ultrashallow p{sup +}/n junctions in silicon. In this study, shallow p{sup +}/n junctions were formed by non-melt annealing implanted samples using a green laser (visible laser). The dopant diffusion, activation, and recrystallization of an amorphous silicon layer were compared with those obtained in our previous study in which non-melt annealing was performed using a KrF excimer laser (UV laser). The experimental results reveal that only slight diffusion of boron in the tail region occurred in green-laser-annealed samples. In contrast, remarkable boron diffusion occurred in KrF-laser-annealed samples for very short annealing times. Recrystallization of the amorphous silicon layer was slower in green-laser-annealed samples than in KrF-laser-annealed samples. We consider the penetration depth and the pulse duration are important factors that may affect boron diffusion. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Shewanella putrefaciens adhesion and biofilm formation on food processing surfaces

    DEFF Research Database (Denmark)

    Bagge, Dorthe; Hjelm, M.; Johansen, C.

    2001-01-01

    Laboratory model systems were developed for studying Shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. S. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. S. putrefaciens bacteria suspended...... in buffer adhered readily to stainless steel surfaces. Maximum numbers of adherent bacteria per square centimeter were reached in 8 h at 25 degreesC and reflected the cell density in suspension. Numbers of adhering bacteria from a suspension containing 10(8) CFU/ml were much lower in a laminar flow system...... (modified Robbins device) (reaching 10(2) CFU/cm(2)) than in a batch system (reaching 10(7) CFU/cm(2)), and maximum numbers were reached after 24 h. When nutrients were supplied, S. putrefaciens grew in biofilms with layers of bacteria. The rate of biofilm formation and the thickness of the film were...

  4. Influence of Process Parameters on Nitrogen Oxide Formation in

    DEFF Research Database (Denmark)

    Lans, Robert Pieter Van Der; Glarborg, Peter; Dam-Johansen, Kim

    1997-01-01

    This paper describes the influence of burner operating conditions, burner geometry and fuel parameters on the formation of nitrogen oxide during combustion of pulverized coal. Main attention has been paid to combustion test facilities with self-sustaining flames, while extensions have been made...... to full scale boilers and furnace modeling. Since coal combustion and flame aerodynamics have been reviewed earlier, these phenomena are only treated briefly....

  5. Suffixes in word-formation processes in scientific English

    OpenAIRE

    Montero Fleta, Maria Begoña

    2011-01-01

    Scholars have stated the particularities of the language used in specialized discourse but little attention has been so far paid to the role derivational morphology may play in register variation. The present research makes a contribution to the study of word-formation in scientific registers by means of a corpus-based approach to the productivity of 14 suffixes in two scientific English registers, i.e., computer science and medicine. In order to empirically examine the prod...

  6. The Role of Parieto-Occipital Junction in the Interaction between Dorsal and Ventral Streams in Disparity-Defined Near and Far Space Processing.

    Directory of Open Access Journals (Sweden)

    Aijun Wang

    Full Text Available Neuropsychological and functional MRI data suggest that two functionally and anatomically dissociable streams of visual processing exist: a ventral perception-related stream and a dorsal action-related stream. However, relatively little is known about how the two streams interact in the intact brain during the production of adaptive behavior. Using functional MRI and a virtual three-dimensional paradigm, we aimed at examining whether the parieto-occipital junction (POJ acts as an interface for the integration and processing of information between the dorsal and ventral streams in the near and far space processing. Virtual reality three-dimensional near and far space was defined by manipulating binocular disparity, with -68.76 arcmin crossed disparity for near space and +68.76 arcmin uncrossed disparity for near space. Our results showed that the POJ and bilateral superior occipital gyrus (SOG showed relative increased activity when responded to targets presented in the near space than in the far space, which was independent of the retinotopic and perceived sizes of target. Furthermore, the POJ showed the enhanced functional connectivity with both the dorsal and ventral streams during the far space processing irrespective of target sizes, supporting that the POJ acts as an interface between the dorsal and ventral streams in disparity-defined near and far space processing. In contrast, the bilateral SOG showed the enhanced functional connectivity only with the ventral stream if retinotopic sizes of targets in the near and far spaces were matched, which suggested there was a functional dissociation between the POJ and bilateral SOG.

  7. Rapid Neutron Capture Process in Supernovae and Chemical Element Formation

    Indian Academy of Sciences (India)

    Rulee Baruah; Kalpana Duorah; H. L. Duorah

    2009-09-01

    The rapid neutron capture process (r-process) is one of the major nucleosynthesis processes responsible for the synthesis of heavy nuclei beyond iron. Isotopes beyond Fe are most exclusively formed in neutron capture processes and more heavier ones are produced by the r-process. Approximately half of the heavy elements with mass number ≻ 70 and all of the actinides in the solar system are believed to have been produced in the r-process. We have studied the r-process in supernovae for the production of heavy elements beyond = 40 with the newest mass values available. The supernova envelopes at a temperature ≻ 109 K and neutron density of 1024 cm-3 are considered to be one of the most potential sites for the r-process. The primary goal of the r-process calculations is to fit the global abundance curve for solar system r-process isotopes by varying time dependent parameters such as temperature and neutron density. This method aims at comparing the calculated abundances of the stable isotopes with observation.We have studied the r-process path corresponding to temperatures ranging from 1.0 × 109 K to 3.0 × 109 K and neutron density ranging from 1020 cm-3 to 1030 cm-3. With temperature and density conditions of 3.0 × 109 K and 1020 cm-3 a nucleus of mass 273 was theoretically found corresponding to atomic number 115. The elements obtained along the r-process path are compared with the observed data at all the above temperature and density range.

  8. Fabrication of BiOBr nanosheets@TiO{sub 2} nanobelts p–n junction photocatalysts for enhanced visible-light activity

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yang [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Huang, Xiang [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); School of Science, Tibet University, Lhasa 850000 (China); Tan, Xin [School of Science, Tibet University, Lhasa 850000 (China); Yu, Tao, E-mail: yutao@tju.edu.cn [School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China); Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072 (China); Li, Xiangli [School of Environmental Science and Engineering, Tianjin University, Tianjin 300072 (China); Yang, Libin [College of Chemical Engineering and Materials Science, Tianjin University of Science & Technology, Tianjin Key Laboratory of Marine Resources and Chemistry, Tianjin 300457 (China); Wang, Shucong [School of Environmental Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2016-03-01

    Graphical abstract: - Highlights: • BiOBr nanosheets@TiO{sub 2} nanobelts p–n junction photocatalysts have been synthesized. • The p–n junction photocatalysts improved water splitting and dye degradation activity. • BiOBr amount in the BiOBr@TiO{sub 2} photocatalysts was investigated. - Abstract: The construction of p–n junction structure is a smart strategy for improving the photocatalytic activity, since p–n junctions can inhibit the recombination of photo-induced charges. Herein, BiOBr nanosheets@TiO{sub 2} nanobelts p–n junction photocatalysts were prepared by assembling BiOBr nanosheets on the surface of TiO{sub 2} nanobelts via a hydrothermal route followed by a co-precipitation process. BiOBr@TiO{sub 2} p–n junction photocatalysts exhibited enhanced photocatalytic activity in photocatalytic H{sub 2} production over water splitting and photodegradation of Rhodamine B (RhB) under visible light irradiation. Mott–Schottky plots confirmed the formation of p–n junctions in the interface of BiOBr and TiO{sub 2}. The enhanced photocatalytic performance can be ascribed to the 1D nanostructure and the formation of p–n junctions. This work shows a potential application of low cost BiOBr as a substitute for noble metals in photocatalytic H{sub 2} production under visible light irradiation.

  9. Shewanella putrefaciens Adhesion and Biofilm Formation on Food Processing Surfaces

    Science.gov (United States)

    Bagge, Dorthe; Hjelm, Mette; Johansen, Charlotte; Huber, Ingrid; Gram, Lone

    2001-01-01

    Laboratory model systems were developed for studying Shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. S. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. S. putrefaciens bacteria suspended in buffer adhered readily to stainless steel surfaces. Maximum numbers of adherent bacteria per square centimeter were reached in 8 h at 25°C and reflected the cell density in suspension. Numbers of adhering bacteria from a suspension containing 108 CFU/ml were much lower in a laminar flow system (modified Robbins device) (reaching 102 CFU/cm2) than in a batch system (reaching 107 CFU/cm2), and maximum numbers were reached after 24 h. When nutrients were supplied, S. putrefaciens grew in biofilms with layers of bacteria. The rate of biofilm formation and the thickness of the film were not dependent on the availability of carbohydrate (lactate or glucose) or on iron starvation. The number of S. putrefaciens bacteria on the surface was partly influenced by the presence of other bacteria (Pseudomonas fluorescens) which reduced the numbers of S. putrefaciens bacteria in the biofilm. Numbers of bacteria on the surface must be quantified to evaluate the influence of environmental factors on adhesion and biofilm formation. We used a combination of fluorescence microscopy (4′,6′-diamidino-2-phenylindole staining and in situ hybridization, for mixed-culture studies), ultrasonic removal of bacteria from surfaces, and indirect conductometry and found this combination sufficient to quantify bacteria on surfaces. PMID:11319118

  10. Formation processes and time scales for meteorite parent bodies

    Science.gov (United States)

    Weidenschilling, S. J.

    1988-01-01

    The transition from small particles suspended in the solar nebula to the planetesimals (asteroids) that became the parent bodies of meteorites is examined. Planetesimals probably grew by coagulation of grain aggregates that collided due to different rates of settling and drag-induced orbital decay. Their growth was accompanied by radial transport of solids, possibly sufficient to deplete the primordial mass in the asteroid zone, but with relatively little mixing. The formation of asteroid-sized planetesimals was probably rapid, on a time scale less than 1 Myr.

  11. Transition and separation process in brine channels formation

    Energy Technology Data Exchange (ETDEWEB)

    Berti, Alessia, E-mail: alessia.berti@unibs.it [Facoltà di Ingegneria, Università e-Campus, Via Isimbardi 10, 22060 Novedrate, CO (Italy); Bochicchio, Ivana, E-mail: ibochicchio@unisa.it [Dipartimento di Matematica, Universitá degli Studi di Salerno, Via Giovanni Paolo II, 84084 Fisciano, SA (Italy); Fabrizio, Mauro, E-mail: mauro.fabrizio@unibo.it [Dipartimento di Matematica, Università di Bologna, Piazza di Porta S. Donato, 40126 Bologna (Italy)

    2016-02-15

    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.

  12. Copper Aluminum Nano Junction Normal Temperature Processes and Methods Applied to the LED High Heat Transfer Performance

    Directory of Open Access Journals (Sweden)

    Ming-Wen Wang

    2014-03-01

    Full Text Available High-power light-emitting diodes (LED have extremely broad applications. However, with the job requirements of high-brightness and high color temperature from light-emitting diodes, it must be followed to enlarge the operating current, thus heating up more rapidly. If its heat dissipation problem cannot be effectively solved, operation will be prone to bring about color shift, and it may even considerably shorten its life. Moreover, application value will therefore be greatly reduced. So in order to enhance the high-power LED luminous brightness and life to cope with the future development needs of high-power LED components, it is necessary to replace the use of conductive silver paste to stick thermally conductive Cu slug fixing grain and lead frame heat dissipation aluminum sheet. This is done by directly bonding thermally conductive Cu slug with pure aluminum, the formation of highly efficient direct heat conduction cooling structure. Therefore the topic points at the crux of the LED heat dissipation difficulty, puts forward of copper and aluminum bonding technology in the ordinary temperature and pressure, method to effectively improve thermal conductivity performance between LED die bond Cu slug and joining aluminum cooling module. This will ultimately make the LED's operation and applications perfect.

  13. A linear process-algebraic format with data for probabilistic automata

    NARCIS (Netherlands)

    Katoen, Joost-Pieter; Pol, van de Jaco; Stoelinga, Mariëlle; Timmer, Mark

    2011-01-01

    This paper presents a novel linear process-algebraic format for probabilistic automata. The key ingredient is a symbolic transformation of probabilistic process algebra terms that incorporate data into this linear format while preserving strong probabilistic bisimulation. This generalises similar te

  14. Novelty processing and memory formation in Parkinson's disease

    NARCIS (Netherlands)

    Schomaker, J; Berendse, H W; Foncke, E M J; van der Werf, Y D; van den Heuvel, O A; Theeuwes, J; Meeter, M

    BACKGROUND: Parkinson's disease (PD) is characterized by a degeneration of nigrostriatal dopaminergic cells, resulting in dopamine depletion. This depletion is counteracted through dopamine replacement therapy (DRT). Dopamine has been suggested to affect novelty processing and memory, which suggests

  15. Electrical Measurement to Assess Hydration Process and the Porosity Formation

    Institute of Scientific and Technical Information of China (English)

    WEI Xiaosheng; XIAO Lianzhen; LI Zongjin

    2008-01-01

    The change of electrical resistivity with time at early ages was used to investigate the hydration process and the porosity development. Porosity reduction process of cement-based materials hydration was developed by a proposed method. The porosity reduction is fast at the setting period. The results find that the pore discontinuity occurs faster at lower water/cement ratios than at higher water/cement ratios which is similar to the results of the Percolation method.

  16. Tandem Solar Cells from Solution-Processed CdTe and PbS Quantum Dots Using a ZnTe-ZnO Tunnel Junction.

    Science.gov (United States)

    Crisp, Ryan W; Pach, Gregory F; Kurley, J Matthew; France, Ryan M; Reese, Matthew O; Nanayakkara, Sanjini U; MacLeod, Bradley A; Talapin, Dmitri V; Beard, Matthew C; Luther, Joseph M

    2017-02-08

    We developed a monolithic CdTe-PbS tandem solar cell architecture in which both the CdTe and PbS absorber layers are solution-processed from nanocrystal inks. Due to their tunable nature, PbS quantum dots (QDs), with a controllable band gap between 0.4 and ∼1.6 eV, are a promising candidate for a bottom absorber layer in tandem photovoltaics. In the detailed balance limit, the ideal configuration of a CdTe (Eg = 1.5 eV)-PbS tandem structure assumes infinite thickness of the absorber layers and requires the PbS band gap to be 0.75 eV to theoretically achieve a power conversion efficiency (PCE) of 45%. However, modeling shows that by allowing the thickness of the CdTe layer to vary, a tandem with efficiency over 40% is achievable using bottom cell band gaps ranging from 0.68 and 1.16 eV. In a first step toward developing this technology, we explore CdTe-PbS tandem devices by developing a ZnTe-ZnO tunnel junction, which appropriately combines the two subcells in series. We examine the basic characteristics of the solar cells as a function of layer thickness and bottom-cell band gap and demonstrate open-circuit voltages in excess of 1.1 V with matched short circuit current density of 10 mA/cm(2) in prototype devices.

  17. Tandem Solar Cells from Solution-Processed CdTe and PbS Quantum Dots Using a ZnTe–ZnO Tunnel Junction

    Energy Technology Data Exchange (ETDEWEB)

    Crisp, Ryan W.; Pach, Gregory F.; Kurley, J. Matthew; France, Ryan M.; Reese, Matthew O.; Nanayakkara, Sanjini U.; MacLeod, Bradley A.; Talapin, Dmitri V.; Beard, Matthew C.; Luther, Joseph M.

    2017-01-10

    We developed a monolithic CdTe-PbS tandem solar cell architecture in which both the CdTe and PbS absorber layers are solution-processed from nanocrystal inks. Due to their tunable nature, PbS quantum dots (QDs), with a controllable band gap between 0.4 and ~1.6 eV, are a promising candidate for a bottom absorber layer in tandem photovoltaics. In the detailed balance limit, the ideal configuration of a CdTe (Eg = 1.5 eV)-PbS tandem structure assumes infinite thickness of the absorber layers and requires the PbS band gap to be 0.75 eV to theoretically achieve a power conversion efficiency (PCE) of 45%. However, modeling shows that by allowing the thickness of the CdTe layer to vary, a tandem with efficiency over 40% is achievable using bottom cell band gaps ranging from 0.68 and 1.16 eV. In a first step toward developing this technology, we explore CdTe-PbS tandem devices by developing a ZnTe-ZnO tunnel junction, which appropriately combines the two subcells in series. We examine the basic characteristics of the solar cells as a function of layer thickness and bottom-cell band gap and demonstrate open-circuit voltages in excess of 1.1 V with matched short circuit current density of 10 mA/cm2 in prototype devices.

  18. Nanostructured Cadmium Sulfide: Sonochemical Synthesis, Optical Properties and Formation Process

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Semiconductor CdS nanoparticles were synthesized by the sonochemical reduction of a mixed aqueous solution ofCdCl2, Na2S2O3 and (CH3)2CHOH in Ar atmosphere at room temperature. The results of a detailed investigationwith X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectrum and optical absorption spec-troscopy are reported. A clearly red shift of the absorption edge and a broad absorption band related to the surfacestates of nanoparticles have been observed in the optical absorption spectra with the increasing of CdS particle size.The mechanisms of the CdS nanoparticle formation and size growth during sonochemical irradiation were discussed.This convenient method is found to be an efficient way to produce other chalcogenides as well.

  19. Grand Junction projects office mixed-waste treatment program, VAC*TRAX mobile treatment unit process hazards analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, R.R.

    1996-04-01

    The objective of this report is to demonstrate that a thorough assessment of the risks associated with the operation of the Rust Geotech patented VAC*TRAX mobile treatment unit (MTU) has been performed and documented. The MTU was developed to treat mixed wastes at the US Department of Energy (DOE) Albuquerque Operations Office sites. The MTU uses an indirectly heated, batch vacuum dryer to thermally desorb organic compounds from mixed wastes. This process hazards analysis evaluated 102 potential hazards. The three significant hazards identified involved the inclusion of oxygen in a process that also included an ignition source and fuel. Changes to the design of the MTU were made concurrent with the hazard identification and analysis; all hazards with initial risk rankings of 1 or 2 were reduced to acceptable risk rankings of 3 or 4. The overall risk to any population group from operation of the MTU was determined to be very low; the MTU is classified as a Radiological Facility with low hazards.

  20. Formation of hypernuclei in evaporation and fission processes

    CERN Document Server

    Botvina, A S; Ergun, A; Ogul, R; Bleicher, M; Pochodzalla, J

    2016-01-01

    There are excellent opportunities to produce excited heavy hyper residues in relativistic hadron and peripheral heavy-ion collisions. We investigate the disintegration of such residues into hyper nuclei via evaporation of baryons and light clusters and their fission. Previously these processes were well known for normal nuclei as the decay channels at low excitation energies. We have generalized these models for the case of hyper-matter. In this way we make extension of nuclear reaction studies at low temperature into the strange sector. We demonstrate how the new decay channels can be integrated in the whole disintegration process. Their importance for mass and isotope distributions of produced hyper-fragments is emphasized. New and exotic isotopes obtained within these processes may provide a unique opportunity for investigating hyperon interaction in nuclear matter.

  1. Formation of hypernuclei in evaporation and fission processes

    Science.gov (United States)

    Botvina, A. S.; Buyukcizmeci, N.; Ergun, A.; Ogul, R.; Bleicher, M.; Pochodzalla, J.

    2016-11-01

    There are excellent opportunities to produce excited heavy hyperresidues in relativistic hadron and peripheral heavy-ion collisions. We investigate the disintegration of such residues into hypernuclei via evaporation of baryons and light clusters and their fission. Previously these processes were well known for normal nuclei as the decay channels at low excitation energies. We have generalized these models for the case of hypermatter. In this way we make extension of nuclear reaction studies at low temperature into the strange sector. We demonstrate how the new decay channels can be integrated in the whole disintegration process. Their importance for mass and isotope distributions of produced hyperfragments is emphasized. New and exotic isotopes obtained within these processes may provide a unique opportunity for investigating hyperon interaction in nuclear matter.

  2. Formation Process of a TiO2 Inverse Opal

    Institute of Scientific and Technical Information of China (English)

    倪培根; 程丙英; 张道中

    2002-01-01

    Inverse opals of TiO2 with different filling fractions were fabricated by using an opal of polystyrene spheres as a template. Scanning electron microscopy showed the accumulative process of TiO2. The transmission spectra of inverse opals with different filling fractions were measured and the shifts of transmission dip with the filling fraction were observed. Our investigation made the infiltration process clear, and it might be helpful for further improvement of the fabrication of TiO2 inverse opals.

  3. Increasing gap junctional coupling: a tool for dissecting the role of gap junctions.

    Science.gov (United States)

    Axelsen, Lene Nygaard; Haugan, Ketil; Stahlhut, Martin; Kjølbye, Anne-Louise; Hennan, James K; Holstein-Rathlou, Niels-Henrik; Petersen, Jørgen Søberg; Nielsen, Morten Schak

    2007-03-01

    Much of our current knowledge about the physiological and pathophysiological role of gap junctions is based on experiments where coupling has been reduced by either chemical agents or genetic modification. This has brought evidence that gap junctions are important in many physiological processes. In a number of cases, gap junctions have been implicated in the initiation and progress of disease, and experimental uncoupling has been used to investigate the exact role of coupling. The inverse approach, i.e., to increase coupling, has become possible in recent years and represents a new way of testing the role of gap junctions. The aim of this review is to summarize the current knowledge obtained with agents that selectively increase gap junctional intercellular coupling. Two approaches will be reviewed: increasing coupling by the use of antiarrhythmic peptide and its synthetic analogs and by interfering with the gating of gap junctional channels.

  4. Fabrication of high-quality submicron Nb/Al-AlOx/Nb tunnel junctions

    Institute of Scientific and Technical Information of China (English)

    Yu Hai-Feng; Cao Wen-Hui; Zhu Xiao-Bo; Yang Hai-Fang; Yu Hong-Wei; Ren Yu-Feng; Gu Chang-Zhi; Chen Geng-Hua; Zhao Shi-Ping

    2008-01-01

    Nb/Al-AlOx/Nb tunnel junctions are often used in the studies of macroscopic quantum phenomena and supercon-ducting qubit applications of the Josepheon devices. In this work, we describe a convenient and reliable process using electron beam lithography for the fabrication of high-quality, submicron-sized Nb/Al-AlOx/Nb Josephson junctions.The technique follows the well-known selective Nb etching process and produces high-quality junctions with Vm=100 mV at 2.3 K for the typical critical current density of 2.2 kA/cm2, which can be adjusted by controlling the oxygen pressure and oxidation time during the formation of the tunnelling barrier. We present the results of the temperature depen-dence of the sub-gap current and in-plane magnetic-field dependence of the critical current, and compare them with the theoretical predictions.

  5. The environmental accountability of efficiency evaluation of processing technogenic formations

    Directory of Open Access Journals (Sweden)

    Olga Sergeyevna Bryantseva

    2011-06-01

    Full Text Available This paper considers environmental and economic aspects of inclusion of man-made iron and steel resources. Theoretical approaches to the concept of damage from environmental pollution caused by activities of metallurgical enterprises are investigated, in particular, the problem of disposal. The importance of categories of damage in the development of economic instruments to address environmental problems of industrial waste storage is emphasized. The total damage from pollution is regarded as a synergistic set of economic and environmental damage. Thus, the basic criterion in determining the economic damage appears to be the cost of resources needed to compensate for the damage to the environment - the time required for self-healing of the system. The possibilities of using waste steel from electric melting production as feedstock for the production of zinc are discussed. An assessment of the effectiveness of the investment project to engage in the processing of industrial wastes in Chelyabinsk Zinc Plant is made. The high efficiency of commercial and financial viability of the proposed technology for processing zinc-containing industrial wastes is shown. Calculations are performed to assess the damage avoided as a result of the processing of man-made structures, which is composed of damage prevention and land degradation and damage from pollution by chemicals. It is shown that cost-effective processing of man-made iron and steel resources is essential to address environmental problems of the metallurgical complex.

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

    Science.gov (United States)

    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.

  7. Particle contamination formation and detection in magnetron sputtering processes

    Energy Technology Data Exchange (ETDEWEB)

    Selwyn, G.S. [Los Alamos National Lab., NM (United States); Weiss, C.A. [Materials Research Corp., Congers, NY (United States). Sputtering Systems Div.; Sequeda, F.; Huang, C. [Seagate Peripherals Disk Div., Milpitas, CA (United States)

    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.

  8. Direct formation of ferrite films in wet process

    Science.gov (United States)

    Abe, M.; Tanno, Y.; Tamaura, Y.

    1985-04-01

    We have prepared a polycrystalline Co-ferrite film by the electroless ferrite-plating technique of our invention [J. Appl. Phys. 55, 2614 (1984)] in an aqueous solution at 70 °C on substrates of organic compounds (polyethylene terephthalate, polymethyl methacrylate, polycarbonate, Teflon), a stainless steel, and a polyester fiber. We used no intermediate layer, which we needed previously to enhance the adhesion of the ferrite film to the surface. By exposing the organic substrates to an rf-excited air plasma, the wettability of the surface improved, which enhanced the adhesion of the film to the substrate. Here we have measured the adhesion by a cross-cut test. The plasma forms hydrophilic groups such as -OH and -COOH, which improve the wettability. The OH group adsorbs the metal ions in the reaction solution, initiating the ferrite film formation. The glass shows a strong adhesion to the film even when it is not exposed to the plasma, because the glass has the OH group on the surface inherently. The stainless steel does not enhance the adhesion by the plasma treatment because the plasma forms no OH group on the metal surface. The adhesion power higher than ˜10 kg/cm2 has been obtained between the Co-ferrite film and the glass (not plasma treated), the polyethylene terephthalate (plasma treated) and the Teflon (plasma treated).

  9. FORMATIVE ADAPTIVE TESTING SERVICE WEB TO INDIVIDUALIZE ELEARNING PROCESS

    Directory of Open Access Journals (Sweden)

    NOUR-EDDINE El FADDOULI

    2011-06-01

    Full Text Available In most of the existing E-learning systems, the content and the order of activities are presented in a static manner without taking into consideration the learner’s characteristics. Therefore, customizing and adapting the environment to the learner’s profile has shown important improvement in education quality. There are several adaptation approaches of E-learning environments, such as, adaptive hypermedia system, semantic web, etc. In our proposed system (RIMEV, we adopted a Competency Based Approach (CBA, and we found that a welladapted system depends mainly on the adequacy of the information collected through a personal diagnostic. This diagnostic takes place via an adaptive test using the Item Response Theory (IRT in a formative approach. This Intelligent test administers optimal items in an appropriate order in a short time and produces a goodassessment of the learner’s skills with accurate results. Thus the e-learning systems can lead the learner to gradually acquire a skill by taking into account his/her characteristics and predispositions.Concerning the technological aspect, the system is implemented as a composed web service, which calls several basic services that coordinate according to an orchestration plan. This allows interoperability with heterogeneous learning systems.

  10. Influences of different types of magnetic fields on HCFC-141b gas hydrate formation processes

    Institute of Scientific and Technical Information of China (English)

    SHU; Bifen; MA; Xiaolin; GUO; Kaihua; LI; Jianhong

    2004-01-01

    In this study, visualizations and experiments are carried out on the influence of static and rotating magnetic fields on the characteristics of HCFC-141b gas hydrate formation, such as crystallization form, formation temperature and induction time. It has been found that a proper rotating magnetic field can considerably improve the low-pressure gas hydrate formation process,especially in increasing the formation temperature and shortening the induction time. The morphology of the gas hydrate formation appears rather complex and compact. However, a proper static magnetic field can make the gas hydrate crystal more organized, which will be benefit to heat transfer.

  11. FORMATION OF SIX SIGMA INFRASTRUCTURE FOR THE CORONARY STENTING PROCESS

    Directory of Open Access Journals (Sweden)

    Mehmet Tolga Taner

    2013-10-01

    Full Text Available The purpose of this study is to show how a tertiary care center in Turkey operating mainly in cardiology initiated Six Sigma principles to reduce the number of complications occuring during coronary stent insertion process. A Six Sigma’s Define-Measure-Analyze-Improve-Control (DMAIC model for coronary stent insertion is suggested. Data were collected for 24-months. Twenty-two Critical-to-Quality (CTQ factors were identified for successful coronary stent insertion. The most frequent causes of complications in the process were found to be patients with previous bypass surgery or PCI, inexperience of staff members, highly damaged vessel structure, thin and/or long vessel diameter, inappropriate selection of stent type, inappropriate selection of balloon type and poor image quality.

  12. Study on the formation mechanism of shock wave in process of coal and gas outburst

    Institute of Scientific and Technical Information of China (English)

    SUN Dong-ling; MIAO Fa-tian; LIANG Yun-pei

    2009-01-01

    According to the research results of motion parameters of coal-gas flow, ana-lyzed the formation mechanism of shock waves at different states of coal-gas flow in the process of coal and gas outburst, and briefly described the two possible cases of outburst shock wave formation and their formation conditions in the process of coal and gas out-burst, and then pointed out that a high degree of under-expanded coal-gas flow was the main reason for the formation of a highly destructive shock wave. The research results improved the shock wave theory in coal and gas outburst.

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

    Science.gov (United States)

    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

  14. The Drosophila genes crumbs and stardust are involved in the biogenesis of adherens junctions.

    Science.gov (United States)

    Grawe, F; Wodarz, A; Lee, B; Knust, E; Skaer, H

    1996-03-01

    Morphogenetic movements of epithelia during development underlie the normal elaboration of the final body plan. The tissue integrity critical for these movements is conferred by anchorage of the cytoskeleton by adherens junctions, initially spot and later belt-like, zonular structures, which encircle the apical side of the cell. Loss-of-function mutations in the Drosophila genes crumbs and stardust lead to the loss of cell polarity in most ectodermally derived epithelia, followed in some, such as the epidermis, by extensive apoptosis. Here we show that both mutants fail to establish proper zonulae adherentes in the epidermis. Our results suggest that the two genes are involved in different aspects of this process. Further, they are compatible with the hypothesis that crumbs delimits the apical border, where the zonula adherens usually forms and where Crumbs protein is normally most abundant. In contrast, stardust seems to be required at an earlier stage for the assembly of the spot adherence junctions. In both mutants, the defect observed at the ultrastructural level are preceded by a misdistribution of Armadillo and DE-cadherin, the homologues of beta-catenin and E-cadherin, respectively, which are two constituents of the vertebrate adherens junctions. Strikingly, expansion of the apical membrane domain in epidermal cells by overexpression of crumbs also abolishes the formation of adherens junctions and results in the disruption of tissue integrity, but without loss of membrane polarity. This result supports the view that membrane polarity is independent of the formation of adherens junctions in epidermal cells.

  15. Identification of neuronal and angiogenic growth factors in an in vitro blood-brain barrier model system: Relevance in barrier integrity and tight junction formation and complexity.

    Science.gov (United States)

    Freese, Christian; Hanada, Sanshiro; Fallier-Becker, Petra; Kirkpatrick, C James; Unger, Ronald E

    2017-05-01

    We previously demonstrated that the co-cultivation of endothelial cells with neural cells resulted in an improved integrity of the in vitro blood-brain barrier (BBB), and that this model could be useful to evaluate the transport properties of potential central nervous system disease drugs through the microvascular brain endothelial. In this study we have used real-time PCR, fluorescent microscopy, protein arrays and enzyme-linked immunosorbent assays to determine which neural- and endothelial cell-derived factors are produced in the co-culture and improve the integrity of the BBB. In addition, a further improvement of the BBB integrity was achieved by adjusting serum concentrations and growth factors or by the addition of brain pericytes. Under specific conditions expression of angiogenic, angiostatic and neurotrophic factors such as endostatin, pigment epithelium derived factor (PEDF/serpins-F1), tissue inhibitor of metalloproteinases (TIMP-1), and vascular endothelial cell growth factor (VEGF) closely mimicked the in vivo situation. Freeze-fracture analysis of these cultures demonstrated the quality and organization of the endothelial tight junction structures and their association to the two different lipidic leaflets of the membrane. Finally, a multi-cell culture model of the BBB with a transendothelial electrical resistance up to 371 (±15) Ω×cm(2) was developed, which may be useful for preliminary screening of drug transport across the BBB and to evaluate cellular crosstalk of cells involved in the neurovascular unit.

  16. Interpersonal Communication in the Process of Value Formation

    Directory of Open Access Journals (Sweden)

    Jozek Milan

    2014-12-01

    Full Text Available Issues of communication, isolation, and education are part of our everyday lives, whether private or professional. The behaviour of the young generation at school and at home has different forms. It demonstrates their actions, way of thinking and feeling. Furthermore, their behaviour expresses their future tendencies. These forms of behaviour are strongly influenced by a lack of communication. As a result, the educational process is made harder, sometimes even impossible. Many experts in ethics, pedagogy and psychology have been paying attention to this issue and have started to evaluate its impact on the young.

  17. Formation of lead dioxide electrodes by the Plante process

    Energy Technology Data Exchange (ETDEWEB)

    Afifi, S.E.; Edwards, W.H.; Hampson, N.A.

    1976-03-01

    The effects of forming agents (aggressive ions) on the electro-oxidation of massive lead (the Plante electrode process) in sulfuric acid solution are reported. Linear sweep voltametric measurements corresponding to the most effective forming agents, ClO/sub 4//sup -/, NO/sub 3//sup -/, BF/sub 4//sup -/, and CH/sub 3/ COO/sup -/, are presented. Other methods of Plante electrode production involving ''ac/dc'' and ''immediate post-deposition oxidation'' are described.

  18. Liquid Argon TPC Signal Formation, Signal Processing and Hit Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Baller, Bruce [Fermilab

    2017-03-11

    This document describes the early stage of the reconstruction chain that was developed for the ArgoNeuT and MicroBooNE experiments at Fermilab. These experiments study accelerator neutrino interactions that occur in a Liquid Argon Time Projection Chamber. Reconstructing the properties of particles produced in these interactions requires knowledge of the micro-physics processes that affect the creation and transport of ionization electrons to the readout system. A wire signal deconvolution technique was developed to convert wire signals to a standard form for hit reconstruction, to remove artifacts in the electronics chain and to remove coherent noise.

  19. Binaries in the field: fossils of the star formation process?

    CERN Document Server

    Parker, Richard J

    2014-01-01

    Recent observations of binary stars in the Galactic field show that the binary fraction and the mean orbital separation both decrease as a function of decreasing primary mass. We present $N$-body simulations of the effects of dynamical evolution in star-forming regions on primordial binary stars to determine whether these observed trends can be explained by the dynamical processing of a common binary population. We find that dynamical processing of a binary population with an initial binary fraction of unity and an initial excess of intermediate/wide separation (100 - 10$^4$ au) binaries does not reproduce the observed properties in the field, even in initially dense ($\\sim 10^3$M$_\\odot$ pc$^{-3}$) star-forming regions. If instead we adopt a field-like population as the initial conditions, most brown dwarf and M-dwarf binaries are dynamically hard and their overall fractions and separation distributions are unaffected by dynamical evolution. G-dwarf and A-star binaries in the field are dynamically intermedia...

  20. Liquid argon TPC signal formation, signal processing and reconstruction techniques

    Science.gov (United States)

    Baller, B.

    2017-07-01

    This document describes a reconstruction chain that was developed for the ArgoNeuT and MicroBooNE experiments at Fermilab. These experiments study accelerator neutrino interactions that occur in a Liquid Argon Time Projection Chamber. Reconstructing the properties of particles produced in these interactions benefits from the knowledge of the micro-physics processes that affect the creation and transport of ionization electrons to the readout system. A wire signal deconvolution technique was developed to convert wire signals to a standard form for hit reconstruction, to remove artifacts in the electronics chain and to remove coherent noise. A unique clustering algorithm reconstructs line-like trajectories and vertices in two dimensions which are then matched to create of 3D objects. These techniques and algorithms are available to all experiments that use the LArSoft suite of software.

  1. VISUAL OBSERBATION OF HCFC141b GAS HYDRATE FORMATION/DECOMPOSITION PROCESS OUTSIDE OF A TUBE

    Institute of Scientific and Technical Information of China (English)

    谢应明; 郭开华; 樊栓狮; 梁德青; 顾建明

    2003-01-01

    In order to design a kind of heat exchanger suitable to the indirect-touched gas hydrate cool storage vessel, a visual observation of HCFC141b gas hydrate formation/decomposition process was presented through a self-designed small-scale visualization apparatus of gas hydrate cool storage. Based on the shooted photos and recorded temperatures, the formation/decomposition process of HCFC141b are described, some characteristics are concluded, and some suggestions of designing heat exchanger are indicated according to the specific characteristics of HCFC141b gas hydrate formation/decomposition process.

  2. A study on NiGe-contacted Ge n+/p Ge shallow junction prepared by dopant segregation technique

    Science.gov (United States)

    Tsui, Bing-Yue; Shih, Jhe-Ju; Lin, Han-Chi; Lin, Chiung-Yuan

    2015-05-01

    In this work, the effect of dopant segregation on the NiGe/n-Ge contact is studied by experiments and first-principles calculations. Both Al-contacted and NiGe-contacted n+/p junctions were fabricated. Phosphorus and arsenic ions were Implanted Before Germanide (IBG) formation or Implanted After Germanide (IAG) formation. The NiGe-contacted junction always exhibit higher forward current than the Al-contacted junction due to dopant segregation. First principles calculations predict that phosphorus atoms tend to segregate on both NiGe side and Ge side while arsenic atoms tend to segregate at Ge side. Since phosphorus has higher activation level and lower diffusion coefficient than arsenic, we propose a phosphorus IBG + arsenic IAG process. Shallow n+/p junction with junction depth 90 nm below the NiGe/Ge interface is achieved. The lowest and average contact resistivity is 2 × 10-6 Ω cm2 and 6.7 × 10-6 Ω cm2, respectively. Methods which can further reduce the junction depth and contact resistivity are suggested.

  3. Process Approach to Formation of the Strategy of Innovation Development of Enterprises

    Directory of Open Access Journals (Sweden)

    Yukhymenko Vita V.

    2013-12-01

    Full Text Available The article considers the process of formation of the strategy of innovation development on the basis of the process approach. The author studies and identifies the most significant cause-effect interrelations between the factors that influence efficiency of the process of formation of the strategy of innovation development of enterprises and their consequences. The article offers a process approach to building the K. Ishikawa diagram based on empirical assessment of management of business processes at railway engineering enterprises. The author’s approach would help solving multiple problems of railway engineering and also could be used in other sectors of economy.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Foam formation in a biotechnological process for the removal of hydrogen sulfide from gas streams

    NARCIS (Netherlands)

    Kleinjan, W.E.; Marcelis, C.L.M.; Keizer, de A.; Janssen, A.J.H.; Cohen Stuart, M.A.

    2006-01-01

    Foam formation in aqueous suspensions of biologically produced sulfur is studied in a foam generator at 30°C, with the objective of describing trends and phenomena that govern foam formation in a biotechnological hydrogen sulfide removal process. Air is bubbled through a suspension and the developme

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

    Science.gov (United States)

    Kleyböcker, A; Liebrich, M; Kasina, M; Kraume, M; Wittmaier, M; Würdemann, H

    2012-06-01

    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) the degradation of volatile fatty acids in the aggregates. Furthermore, this mechanism enabled a stable process performance after re-activation of biogas production. In contrast, during the counter measure with NaOH aggregate formation was only minor resulting in a rapid process failure subsequent the increase of the organic loading rate.

  7. Rapid image-segmentation and perceptual transparency share a process which utilises X-junctions generated by temporal integration in the visual system.

    Science.gov (United States)

    Mitsudo, Hiroyuki

    2004-01-01

    Perceptual transparency requires local same-polarity X-junctions, which can also be generated by temporal integration under natural dynamic conditions. In this study, segmentation performance and target appearance were measured for a uniform gray target embedded in a random-dot frame presented with a temporally adjacent mask. Although static cues for both segmentation and transparency were unavailable, transparency was observed only when collinear same-polarity edges reduced backward masking, in both the fovea and the perifovea. These results suggest that the visual system has a common underlying mechanism for rapid segmentation and transparency, which utilises same-polarity X-junctions generated by temporal integration.

  8. Investigation of complex formation processes of hydroxypropylmethylcellulose and polymethacrylic acid in aqueous solutions

    Directory of Open Access Journals (Sweden)

    M. Katayeva

    2012-12-01

    Full Text Available The complex formation process of hydroxypropylcellulose (HPC with polymethacrylic acid (PMA have been studied using methods of turbidimetric and viscosimetric titration. Position of maximum depending on polymer concentration and molecular mass of polysaccharide have different values.

  9. In vivo formation and bioavailability of isothiocyanates from glucosinolates in broccoli as affected by processing conditions

    NARCIS (Netherlands)

    Oliviero, T.; Verkerk, R.; Vermeulen, M.; Dekker, M.

    2014-01-01

    Scope: To study the effect of residual myrosinase (MYR) activity in differently processed broccoli on sulforaphane (SR) and iberin (IB) formation, bioavailability, and excretion in human volunteers. Methods and results: Five different broccoli products were obtainedwith similar glucoraphanin (GR)

  10. Simulation of sub-micron particle formation and growth during combustion processes

    Institute of Scientific and Technical Information of China (English)

    WEI Feng; ZHANG Junying; ZHENG Chuguang

    2005-01-01

    Sub-micron particle formation and growth during combustion processes is very complex because of its strong uncertainty and randomness. A model to simulate the sub-micron particle formation and growth during the combustion process is developed based on the gas kinetic theory and is expressed by the vapor concentration changes and particle loading changes, which reflects effect characteristics of different mechanism (nucleation, condensation and coagulation) in particle formation processes. The developed characteristic time is used to token the three mechanisms. It is thought that environmental temperature and pressure, vapor temperature and critical pressure are important factors influencing the sub-micron particle formation and growth. The sub-micron particle formation processes under different conditions are studied and the effect characteristics of these mechanisms are analyzed, which show that the nucleation, condensation,and coagulation occur simultaneously during the sub-micron particle formation and growth process. Nucleation contributes to the sub-micron particle formation, while condensation and coagulation is helpful to the growth of the particle size.

  11. On the formation and evolution of the Pannonian Basin: Constraints derived from the structure of the junction area between the Carpathians and Dinarides

    NARCIS (Netherlands)

    Matenco, L.; Radivojević, D.

    2012-01-01

    The large number and distribution of rollback systems in Mediterranean orogens infer the possibility of interacting extensional back-arc deformation driven by different slabs. The formation of the Pannonian back-arc basin is generally related to the rapid Miocene rollback of a slab attached to the E

  12. The fission yeast meiosis-specific Dmc1 recombinase mediates formation and branch migration of Holliday junctions by preferentially promoting strand exchange in a direction opposite to that of Rad51.

    Science.gov (United States)

    Murayama, Yasuto; Tsutsui, Yasuhiro; Iwasaki, Hiroshi

    2011-03-01

    Homologous recombination proceeds via the formation of several intermediates including Holliday junctions (HJs), which are important for creating crossover products. DNA strand exchange is a core reaction that produces these intermediates that is directly catalyzed by RecA family recombinases, of which there are two types in eukaryotes: universal Rad51 and meiosis-specific Dmc1. We demonstrated previously that Rad51 promotes four-strand exchange, mimicking the formation and branch migration of HJs. Here we show that Dmc1 from fission yeast has a similar activity, which requires ATP hydrolysis and is independent of an absolute requirement for the Swi5-Sfr1 complex. These features are critically different from three-strand exchange mediated by Dmc1, but similar to those of four-strand exchange mediated by Rad51, suggesting that strand exchange reactions between duplex-duplex and single-duplex DNAs are mechanistically different. Interestingly, despite similarities in protein structure and in reaction features, the preferential polarities of Dmc1 and Rad51 strand exchange are different (Dmc1 promotes exchange in the 5'-to-3' direction and Rad51 promotes exchange in the 3'-to-5' direction relative to the ssDNA region of the DNA substrate). The significance of the Dmc1 polarity is discussed within the context of the necessity for crossover production.

  13. Magnetic tunnel junctions (MTJs)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We review the giant tunnel magnetoresistance (TMR) in ferromagnetic-insulator-ferromagnetic junctions discovered in recent years, which is the magnetoresistance (MR) associated with the spin-dependent tunneling between two ferromagnetic metal films separated by an insulating thin tunnel barrier. The theoretical and experimental results including junction conductance, magnetoresistance and their temperature and bias dependences are described.

  14. Stacked Josephson Junctions

    DEFF Research Database (Denmark)

    Madsen, Søren Find; Pedersen, Niels Falsig; Christiansen, Peter Leth

    2010-01-01

    Long Josephson junctions have for some time been considered as a source of THz radiation. Solitons moving coherently in the junctions is a possible source for this radiation. Analytical computations of the bunched state and bunching-inducing methods are reviewed. Experiments showing THz radiation...

  15. The effect of an East Pacific Rise offset on the formation of secondary cracks ahead of the Cocos-Nazca Rift at the Galapagos Triple Junction

    Science.gov (United States)

    Smith, D. K.; Montesi, L. G.; Schouten, H.; Zhu, W.

    2011-12-01

    A succession of short-lived, E-W trending cracks at the Galapagos Triple Junction north and south of the Cocos-Nazca (C-N) Rift, has been explained by a simple crack interaction model. The locations of where the cracks initiate are controlled by tensile stresses generated at the East Pacific Rise (EPR) by two interacting cracks: One representing the north-south trending EPR, and the other the large, westward propagating C-N Rift, whose tip is separated from the EPR by a distance D. The model predicts symmetric cracking at the EPR north and south of the C-N Rift tip. Symmetry in the distribution of cracks north and south of the C-N Rift is observed and especially remarkable between 2.5 and 1.5 Ma when the rapid jumping of cracks toward the C-N Rift appears synchronous. The rapid jumping can be explained by decreasing D, which means that the tip of the C-N Rift was moving closer to the EPR. Symmetry of cracking breaks down at 1.5 Ma, however, with the establishment of the Dietz Deep Rift, the southern boundary of the Galapagos microplate. Symmetry of cracking also breaks down on older crust to the east between about 100 35'W and 100 45'W (about 2.6 Ma) where a rapid jumping of cracks toward the C-N Rift is observed in the south cracking region. There is no evidence of similar rapid jumping in the north cracking region. It could be simply that the response to changing the value of D is not always as predicted. It could also be that the shape of the EPR has not always been symmetric about the C-N Rift, as assumed in the model. Currently, an overlapping spreading center with a 15 km east-west offset between the limbs of the EPR has formed at 1 50'N. We assess the importance of the geometry of the EPR on the crack interaction model. The model has been modified to include a ridge offset similar to what is observed today. We find that the region of stress enhancement at the EPR (where cracks initiate) is subdued south of the C-N Rift tip because of the EPR offset. It is

  16. Estimation of Wellbore and Formation Temperatures during the Drilling Process under Lost Circulation Conditions

    Directory of Open Access Journals (Sweden)

    Mou Yang

    2013-01-01

    Full Text Available Significant change of wellbore and surrounding formation temperatures during the whole drilling process for oil and gas resources often leads by annulus fluid fluxes into formation and may pose a threat to operational security of drilling and completion process. Based on energy exchange mechanisms of wellbore and formation systems during circulation and shut-in stages under lost circulation conditions, a set of partial differential equations were developed to account for the transient heat exchange process between wellbore and formation. A finite difference method was used to solve the transient heat transfer models, which enables the wellbore and formation temperature profiles to be accurately predicted. Moreover, heat exchange generated by heat convection due to circulation losses to the rock surrounding a well was also considered in the mathematical model. The results indicated that the lost circulation zone and the casing programme had significant effects on the temperature distributions of wellbore and formation. The disturbance distance of formation temperature was influenced by circulation and shut-in stages. A comparative perfection theoretical basis for temperature distribution of wellbore-formation system in a deep well drilling was developed in presence of lost circulation.

  17. Galaxy formation in the Planck cosmology III: star-formation histories and post-processing magnitude reconstruction

    CERN Document Server

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

    2015-01-01

    We adapt the L-Galaxies semi-analytic model to follow the star-formation histories (SFH) 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 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: SF...

  18. Septal Junctions in Filamentous Heterocyst-Forming Cyanobacteria.

    Science.gov (United States)

    Flores, Enrique; Herrero, Antonia; Forchhammer, Karl; Maldener, Iris

    2016-02-01

    In the filaments of heterocyst-forming cyanobacteria, septal junctions that traverse the septal peptidoglycan join adjacent cells, allowing intercellular communication. Perforations in the septal peptidoglycan have been observed, and proteins involved in the formation of such perforations and putative protein components of the septal junctions have been identified, but their relationships are debated.

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

    Science.gov (United States)

    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.

  20. Atomically Abrupt Topological p-n Junction.

    Science.gov (United States)

    Kim, Sung Hwan; Jin, Kyung-Hwan; Kho, Byung Woo; Park, Byeong-Gyu; Liu, Feng; Kim, Jun Sung; Yeom, Han Woong

    2017-08-24

    Topological insulators (TI's) are a new class of quantum matter with extraordinary surface electronic states, which bear great potential for spintronics and error-tolerant quantum computing. In order to put a TI into any practical use, these materials need to be fabricated into devices whose basic units are often p-n junctions. Interesting electronic properties of a 'topological' p-n junction were proposed theoretically such as the junction electronic state and the spin rectification. However, the fabrication of a lateral topological p-n junction has been challenging because of materials, process, and fundamental reasons. Here, we demonstrate an innovative approach to realize a p-n junction of topological surface states (TSS's) of a three-dimensional (3D) topological insulator (TI) with an atomically abrupt interface. When a ultrathin Sb film is grown on a 3D TI of Bi2Se3 with a typical n-type TSS, the surface develops a strongly p-type TSS through the substantial hybridization between the 2D Sb film and the Bi2Se3 surface. Thus, the Bi2Se3 surface covered partially with Sb films bifurcates into areas of n- and p-type TSS's as separated by atomic step edges with a lateral electronic junction of as short as 2 nm. This approach opens a different avenue toward various electronic and spintronic devices based on well-defined topological p-n junctions with the scalability down to atomic dimensions.

  1. The Dissolution of Double Holliday Junctions

    DEFF Research Database (Denmark)

    Bizard, Anna H; Hickson, Ian D

    2014-01-01

    as "double Holliday junction dissolution." This reaction requires the cooperative action of a so-called "dissolvasome" comprising a Holliday junction branch migration enzyme (Sgs1/BLM RecQ helicase) and a type IA topoisomerase (Top3/TopoIIIα) in complex with its OB (oligonucleotide/oligosaccharide binding......) fold containing accessory factor (Rmi1). This review details our current knowledge of the dissolution process and the players involved in catalyzing this mechanistically complex means of completing homologous recombination reactions....

  2. TRANSFORMATION OF EFFUSION AND FORMATION OF GRANULATION TISSUE IN PATHOLOGIC PROCESS OF OTITIS MEDIA WITH EFFUSION

    Institute of Scientific and Technical Information of China (English)

    韦俊荣; 张青; 张全安

    2003-01-01

    Objective To explore the diversity of stagnant effusions and the pathologic processes leading to granulation tissue formation in otitis media with effusion(OME). Methods Temporal bone slides from 306 ears with OME were studied histopathologically under the light microscope. Results Results of this study revealed a pathologic process in witch the type and the condition of stagnant effusion in the middle ear cleft was a variable in the dynamics of OME progression from an early stage to an advanced stage. The location of granulation tissue and retentive effusion were found to be closely related. Conclusion Early stage granulation tissue formation exhibited a pathologic process in which granulation tissue formation occurred only in areas where effusion had stagnated or was absorbed. The incidence of the retentive effusion and formation of granulation tissue was much higher and the pathologic changes most extensive in the area around the ossicular chain.

  3. Assemble four-arm DNA junctions into nanoweb

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    DNA is of structural polymorphism, which is useful in nanoarchitecture; especially, four-arm DNA junc tions can be used to assemble nanowebs. The static four-arm DNA junctions were designed and synthesized. One-arm DNA and two-arm DNA came out simultaneously with the four-arm DNA junction's formation. A new method, termed the two-step method, was proposed and the productivity of four-arm DNA junctions was increased. A nanoweb was assembled successfully, but it showed irregularity itself. It was not the same as we expected. We consider that it is aresult from the flexibility of four-arm DNA junction.

  4. The experimental production of matrix lumps within chondrules: Evidence of post-formational processes

    Science.gov (United States)

    Connolly, Harold C., Jr.; Hewins, Roger H.

    1993-01-01

    The processes that acted upon chondrules after their formation are as important clues to the nature of the early solar nebula as are the exact processes that formed the chondrules. Recent experiments have studied the rim forming processes and the effects the processes have on chondrules. We present below information on how matrix inclusions found within chondrules may have been formed and the potential usefulness of this information.

  5. Alternative types of molecule-decorated atomic chains in Au–CO–Au single-molecule junctions

    Directory of Open Access Journals (Sweden)

    Zoltán Balogh

    2015-06-01

    Full Text Available We investigate the formation and evolution of Au–CO single-molecule break junctions. The conductance histogram exhibits two distinct molecular configurations, which are further investigated by a combined statistical analysis. According to conditional histogram and correlation analysis these molecular configurations show strong anticorrelations with each other and with pure Au monoatomic junctions and atomic chains. We identify molecular precursor configurations with somewhat higher conductance, which are formed prior to single-molecule junctions. According to detailed length analysis two distinct types of molecule-affected chain-formation processes are observed, and we compare these results to former theoretical calculations considering bridge- and atop-type molecular configurations where the latter has reduced conductance due to destructive Fano interference.

  6. Increasing gap junctional coupling: a tool for dissecting the role of gap junctions

    DEFF Research Database (Denmark)

    Axelsen, Lene Nygaard; Haugan, Ketil; Stahlhut, Martin;

    2007-01-01

    . In a number of cases, gap junctions have been implicated in the initiation and progress of disease, and experimental uncoupling has been used to investigate the exact role of coupling. The inverse approach, i.e., to increase coupling, has become possible in recent years and represents a new way of testing......Much of our current knowledge about the physiological and pathophysiological role of gap junctions is based on experiments where coupling has been reduced by either chemical agents or genetic modification. This has brought evidence that gap junctions are important in many physiological processes...... the role of gap junctions. The aim of this review is to summarize the current knowledge obtained with agents that selectively increase gap junctional intercellular coupling. Two approaches will be reviewed: increasing coupling by the use of antiarrhythmic peptide and its synthetic analogs...

  7. Heterodimers formed through a partial anionic exchange process: scanning tunneling spectroscopy to monitor bands across the junction vis-à-vis photoinduced charge separation

    Science.gov (United States)

    Bera, Abhijit; Saha, Sudip K.; Pal, Amlan J.

    2015-10-01

    We report controlled formation of heterodimers and their charge separation properties. CdS|CdTe heterodimers were formed through an anionic exchange process of CdS nanostructures. With control over the duration of the anionic exchange process, bulk|dot, bulk|bulk, and then dot|bulk phases of the semiconductors could be observed to have formed. A mapping of density of states as derived from scanning tunneling spectroscopy (STS) brought out conduction and valence band-edges along the nanostructures and heterodimers. The CdS|CdTe heterodimers evidenced a type-II band-alignment between the semiconductors along with the formation of a depletion region at the interface. The width (of the depletion region) and the energy-offset at the interface depended on the size of the semiconductors. We report that the width that is instrumental for photoinduced charge separation in the heterodimers has a direct correlation with the performance of hybrid bulk-heterojunction solar cells based on the nanostructures in a polymer matrix.We report controlled formation of heterodimers and their charge separation properties. CdS|CdTe heterodimers were formed through an anionic exchange process of CdS nanostructures. With control over the duration of the anionic exchange process, bulk|dot, bulk|bulk, and then dot|bulk phases of the semiconductors could be observed to have formed. A mapping of density of states as derived from scanning tunneling spectroscopy (STS) brought out conduction and valence band-edges along the nanostructures and heterodimers. The CdS|CdTe heterodimers evidenced a type-II band-alignment between the semiconductors along with the formation of a depletion region at the interface. The width (of the depletion region) and the energy-offset at the interface depended on the size of the semiconductors. We report that the width that is instrumental for photoinduced charge separation in the heterodimers has a direct correlation with the performance of hybrid bulk

  8. Advanced nanopattern formation by a subtractive self-organization process with focused ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Lugstein, A. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria)]. E-mail: alois.lugstein@tuwien.ac.at; Basner, B. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria); Brezna, W. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria); Weil, M. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria); Golka, S. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria); Bertagnolli, E. [Technical University Vienna, Floragasse 7, 1040 Vienna (Austria)

    2006-01-15

    We have studied the evolution of the GaAs, InAs and GaSb surfaces due to FIB exposure. In contrast to conventional bottom up or top down processes the observed nanopattern formation is discussed, based on a subtractive self-organization process relying on material decomposition induced by FIB exposure.

  9. Heteroepitaxial Junction in Au-ZnSe Nanostructure: Experiment versus First-Principle Simulation.

    Science.gov (United States)

    Bose, Riya; Wasey, A H M Abdul; Das, Gour P; Pradhan, Narayan

    2014-06-05

    Composing together the experimental as well as the simulated results, we demonstrate here the atomic placements and the electronic structure at the epitaxial junction of a solution-processed heteronanostructure Au-ZnSe. Despite the large lattice mismatch (∼32%) between fcc Au and zinc-blende structured ZnSe, the heterostructures are formed via coincidence site epitaxy, which appears periodically because of the arrangements of their proper unit cell placements at the junction. This reduces the interface energy and drives the formation of such heteronanostructures. Details of the physical processes involved in the formation of these nanostructures have been discussed in this letter, and epitaxy at the heterojunction is strongly supported by HRTEM measurement and DFT calculation. This material has the possibility of plasmon-exciton coupling and therefore might be a futuristic material for utilizations in catalysis, nanoelectronics, and other related applications.

  10. Comparative analysis of gas–liquid flow in T-junction microchannels with different inlet orientations

    Directory of Open Access Journals (Sweden)

    Dongren Liu

    2016-03-01

    Full Text Available In this study, a comparative analysis of two-phase flow in T-junction microchannels with different inlet orientations was carried out. Based on computational fluid dynamics and the volume-of-fluid model, bubble size, bubble velocities, and pressure distributions were analyzed. The numerical algorithm was validated with the experimental observations from former literatures; the results show that when the capillary number, Ca, is low, the length of gas and liquid slug in the symmetric T-junction is higher than that in the cross-flow T-junction. The effect of different forces acting on the slugs during the process of bubble formation was studied by investigating the velocity gradient and pressure distribution in the mixing zone. The result shows that the shear stress in cross-flow T-junction is over two times of that in T-junction with two symmetric inlets under the same operating conditions, which indicates that the size of bubble and liquid slug depends on the shear stress at low Ca number.

  11. "Formative ""Use"" of Assessment Information: It's a Process, so Let's Say What We Mean"

    Directory of Open Access Journals (Sweden)

    Robert Good

    2011-02-01

    Full Text Available The term formative assessment is often used to describe a type of assessment. The purpose of this paper is to challenge the use of this phrase given that formative assessment as a noun phrase ignores the well-established understanding that it is a process more than an object. A model that combines content, context, and strategies is presented as one way to view the process nature of assessing formatively. The alternate phrase formative use of assessment information is suggested as a more appropriate way to describe how content, context, and strategies can be used together in order to close the gap between where a student is performing currently and the intended learning goal.

  12. N-nitrosamines in processed meat products – analysis, occurrence, formation, mitigation and exposure

    DEFF Research Database (Denmark)

    Herrmann, Susan Strange

    products already available, though several areas especially regarding non-volatile NA (NVNA) are relatively unexplored. Studies performed in actual meat products are also scarce. The more that is understood about which factors affects the formation of both volatile NA (VNA) and NVNA the more likely...... is it to identify strategies for the prevention of NA formation in general and not only for a few NA. The aim of the present thesis was therefore to study the role of ingoing amount of nitrite, factors relevant for industrial processing of meat, fat content and the effect of heat treatment on the formation of VNA...... nitrite was added. This may indicate that the relevant precursors are not present. Studies by others have indicated especially the formation of NDMA to depend more on factors as meat quality including feeding and/or breeding conditions and processing factors as temperatures and duration of drying...

  13. Managing fear in public health campaigns: a theory-based formative evaluation process.

    Science.gov (United States)

    Cho, Hyunyi; Witte, Kim

    2005-10-01

    The HIV/AIDS infection rate of Ethiopia is one of the world's highest. Prevention campaigns should systematically incorporate and respond to at-risk population's existing beliefs, emotions, and perceived barriers in the message design process to effectively promote behavior change. However, guidelines for conducting formative evaluation that are grounded in proven risk communication theory and empirical data analysis techniques are hard to find. This article provides a five-step formative evaluation process that translates theory and research for developing effective messages for behavior change. Guided by the extended parallel process model, the five-step process helps message designers manage public's fear surrounding issues such as HIV/AIDS. An entertainment education project that used the process to design HIV/AIDS prevention messages for Ethiopian urban youth is reported. Data were collected in five urban regions of Ethiopia and analyzed according to the process to develop key messages for a 26-week radio soap opera.

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

    Science.gov (United States)

    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.

  15. Rho/Rho-associated Kinase-II Signaling Mediates Disassembly of Epithelial Apical Junctions

    OpenAIRE

    2007-01-01

    Apical junctional complex (AJC) plays a vital role in regulation of epithelial barrier function. Disassembly of the AJC is observed in diverse physiological and pathological states; however, mechanisms governing this process are not well understood. We previously reported that the AJC disassembly is driven by the formation of apical contractile acto-myosin rings. In the present study, we analyzed the signaling pathways regulating acto-myosin–dependent disruption of AJC by using a model of ext...

  16. Equivalent Josephson junctions

    Science.gov (United States)

    Boyadjiev, T. L.; Semerdjieva, E. G.; Shukrinov, Yu. M.

    2008-01-01

    The magnetic field dependences of critical current are numerically constructed for a long Josephson junction with a shunt-or resistor-type microscopic inhomogeneities and compared to the critical curve of a junction with exponentially varying width. The numerical results show that it is adequate to replace the distributed inhomogeneity of a long Josephson junction by an inhomogeneity localized at one of its ends, which has certain technological advantages. It is also shown that the critical curves of junctions with exponentially varying width and inhomogeneities localized at the ends are unaffected by the mixed fluxon-antifluxon distributions of the magnetic flow. This fact may explain the improvement of the spectra of microwave radiation noted in the literature.

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

    Science.gov (United States)

    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).

  18. Structure-Property Relationships in Atomic-Scale Junctions: Histograms and Beyond.

    Science.gov (United States)

    Hybertsen, Mark S; Venkataraman, Latha

    2016-03-15

    Over the past 10 years, there has been tremendous progress in the measurement, modeling and understanding of structure-function relationships in single molecule junctions. Numerous research groups have addressed significant scientific questions, directed both to conductance phenomena at the single molecule level and to the fundamental chemistry that controls junction functionality. Many different functionalities have been demonstrated, including single-molecule diodes, optically and mechanically activated switches, and, significantly, physical phenomena with no classical analogues, such as those based on quantum interference effects. Experimental techniques for reliable and reproducible single molecule junction formation and characterization have led to this progress. In particular, the scanning tunneling microscope based break-junction (STM-BJ) technique has enabled rapid, sequential measurement of large numbers of nanoscale junctions allowing a statistical analysis to readily distinguish reproducible characteristics. Harnessing fundamental link chemistry has provided the necessary chemical control over junction formation, enabling measurements that revealed clear relationships between molecular structure and conductance characteristics. Such link groups (amines, methylsuflides, pyridines, etc.) maintain a stable lone pair configuration that selectively bonds to specific, undercoordinated transition metal atoms available following rupture of a metal point contact in the STM-BJ experiments. This basic chemical principle rationalizes the observation of highly reproducible conductance signatures. Subsequently, the method has been extended to probe a variety of physical phenomena ranging from basic I-V characteristics to more complex properties such as thermopower and electrochemical response. By adapting the technique to a conducting cantilever atomic force microscope (AFM-BJ), simultaneous measurement of the mechanical characteristics of nanoscale junctions as they

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  1. Junctional neurulation: a unique developmental program shaping a discrete region of the spinal cord highly susceptible to neural tube defects.

    Science.gov (United States)

    Dady, Alwyn; Havis, Emmanuelle; Escriou, Virginie; Catala, Martin; Duband, Jean-Loup

    2014-09-24

    In higher vertebrates, the primordium of the nervous system, the neural tube, is shaped along the rostrocaudal axis through two consecutive, radically different processes referred to as primary and secondary neurulation. Failures in neurulation lead to severe anomalies of the nervous system, called neural tube defects (NTDs), which are among the most common congenital malformations in humans. Mechanisms causing NTDs in humans remain ill-defined. Of particular interest, the thoracolumbar region, which encompasses many NTD cases in the spine, corresponds to the junction between primary and secondary neurulations. Elucidating which developmental processes operate during neurulation in this region is therefore pivotal to unraveling the etiology of NTDs. Here, using the chick embryo as a model, we show that, at the junction, the neural tube is elaborated by a unique developmental program involving concerted movements of elevation and folding combined with local cell ingression and accretion. This process ensures the topological continuity between the primary and secondary neural tubes while supplying all neural progenitors of both the junctional and secondary neural tubes. Because it is distinct from the other neurulation events, we term this phenomenon junctional neurulation. Moreover, the planar-cell-polarity member, Prickle-1, is recruited specifically during junctional neurulation and its misexpression within a limited time period suffices to cause anomalies that phenocopy lower spine NTDs in human. Our study thus provides a molecular and cellular basis for understanding the causality of NTD prevalence in humans and ascribes to Prickle-1 a critical role in lower spinal cord formation.

  2. Diffusion effects on formation process of mesoporous molecular sieve MCM-41

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The regular mesoporous molecular sieve MCM-41 has been investigated at different stages during its formation,using high resolution transmission electron microscopy and powder X-ray diffraction.The results not only support the liquid-crystal templating mechanism previously postulated,but allow the extension fo its scope to discribe ditails of MCM-41 formation.It has been observed that formation of the hexagonal liquid crystal phase on the one hand and of silica aggregates on the other,occurs simultaneously at the inception of gel formation and throughout the crystallisation.This process is most probably affected by diffusion of both the surfactant molecules and the oligomeric silicate ions.With this postulate it becomes possible to explain several experimental observation(both old and new)and to develop a multi-step synthesis method to grow large particles of MCM-41 using small calcined crystals of MCM-41 as seeds.

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

    Science.gov (United States)

    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.

  4. Dislocation Multi-junctions and Strain Hardening

    Energy Technology Data Exchange (ETDEWEB)

    Bulatov, V; Hsiung, L; Tang, M; Arsenlis, A; Bartelt, M; Cai, W; Florando, J; Hiratani, M; Rhee, M; Hommes, G; Pierce, T; Diaz de la Rubia, T

    2006-06-20

    At the microscopic scale, the strength of a crystal derives from the motion, multiplication and interaction of distinctive line defects--dislocations. First theorized in 1934 to explain low magnitudes of crystal strength observed experimentally, the existence of dislocations was confirmed only two decades later. Much of the research in dislocation physics has since focused on dislocation interactions and their role in strain hardening: a common phenomenon in which continued deformation increases a crystal's strength. The existing theory relates strain hardening to pair-wise dislocation reactions in which two intersecting dislocations form junctions tying dislocations together. Here we report that interactions among three dislocations result in the formation of unusual elements of dislocation network topology, termed hereafter multi-junctions. The existence of multi-junctions is first predicted by Dislocation Dynamics (DD) and atomistic simulations and then confirmed by the transmission electron microscopy (TEM) experiments in single crystal molybdenum. In large-scale Dislocation Dynamics simulations, multi-junctions present very strong, nearly indestructible, obstacles to dislocation motion and furnish new sources for dislocation multiplication thereby playing an essential role in the evolution of dislocation microstructure and strength of deforming crystals. Simulation analyses conclude that multi-junctions are responsible for the strong orientation dependence of strain hardening in BCC crystals.

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

    Science.gov (United States)

    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.

  6. Pearl formation: persistence of the graft during the entire process of biomineralization.

    Science.gov (United States)

    Arnaud-Haond, S; Goyard, E; Vonau, V; Herbaut, C; Prou, J; Saulnier, D

    2007-01-01

    Most bivalves species of the genus Pinctada are well known throughout the world for production of white or black pearls of high commercial value. For cultured pearl production, a mantle allograft from a donor is implanted into the gonad of a recipient oyster, together with a small inorganic bead. Because of the dedifferentiation of cells during the first steps of the host oyster's immunological reaction, so far the fate of the graft and its exact role in the process of pearl formation could not be determined via classical histological methods. Here we report the first molecular evidence of the resilience of the graft in the recipient organism by showing that cells containing genome from the donor are still present at the end of pearl formation. These results suggest the existence of a unique biological cooperation leading to the successful biomineralization process of nacreous secretion in pearl formation.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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…

  10. Socio-psychological processes of identity formation among EE/ESD enthusiast

    DEFF Research Database (Denmark)

    Læssøe, Jeppe; Lysgaard, Jonas Greve

    Introduction: When engaging with normative educational ideals such as education for sustainable development (ESD), such ideals heavily influence socio-psychological processes of identity formation among individuals and groups. This is especially important when looking into enthusiasts and facilit......Introduction: When engaging with normative educational ideals such as education for sustainable development (ESD), such ideals heavily influence socio-psychological processes of identity formation among individuals and groups. This is especially important when looking into enthusiasts...... and facilitators that often play an important role when dealing with ESD issues especially in a non-formal perspective among e.g. NGO. Objectives: In this paper we argue that socio-psychological processes of identity formation within non-formal ESD are under illuminated and should play a greater role when...... navigating the often contradictionary field of ESD, Methods: This paper is a theoretical study drawing on theories focusing on socio-psychological processes of identity formation such as psychoanalysis, European-continental social psychology and micro-sociology. The paper also draws on recent empirical...

  11. Formation, Molecular Structure, and Morphology of Humins in Biomass Conversion : Influence of Feedstock and Processing Conditions

    NARCIS (Netherlands)

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

    2013-01-01

    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 ex

  12. Analysis of the hydrolysis process in the formation of supergene zone mining areas

    Directory of Open Access Journals (Sweden)

    Sherstjuk N.P.

    2010-06-01

    Full Text Available The analysis of processes of hydrolysis of silicates and alumosilicat which arrive in a landscape from tails of enrichment of iron ore is carried out. Assessment and forecast formation of minerals zone hipcrhenezu iron deposits was carried out.

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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…

  16. A System for Processing and Shelving Works of Mixed Media Format.

    Science.gov (United States)

    Mann, Thomas J.

    1979-01-01

    A system for processing and shelving mixed media works is described, the advantage of which is its ability to make value judgments reflecting the author's intention as to which format is primary. Security needs, storage space problems, and desirability of maintaining browsing capabilities are also incorporated in this system. (Author/MBR)

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

    Science.gov (United States)

    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 (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.

  18. The Mediating Role of Psychosocial Benefits in the Satisfaction Formation Process

    NARCIS (Netherlands)

    O. Prevo; P. Leunisse; H. Roest (Henk)

    1999-01-01

    textabstractIn this paper we investigate the mediating role of psychosocial benefits in the customer satisfaction/dissatisfaction formation process. Most research on this subject deals with the causality direction of psychosocial benefits and satisfaction, sometimes preceded by an overall functional

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

    Science.gov (United States)

    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…

  20. The emotional effects of news frames on information processing and opinion formation

    NARCIS (Netherlands)

    Kühne, R.; Schemer, C.

    2015-01-01

    Current approaches explain the effects of news frames on judgments in terms of cognitive mechanisms, such as accessibility and applicability effects. We investigated the emotional effects of two news frames—an "anger" frame and a "sadness" frame—on information processing and opinion formation. We

  1. Researching International Processes of Education Policy Formation: Conceptual and Methodological Considerations

    Science.gov (United States)

    Edwards, D. Brent, Jr.

    2012-01-01

    This article elaborates one approach to conceptualizing and investigating international processes of education policy formation (IPEPF), which are dynamic, multi-level and processual in nature. This contribution is important because, although research is increasingly conducted on phenomena with such characteristics, extended discussions of how…

  2. The Mediating Role of Psychosocial Benefits in the Satisfaction Formation Process

    NARCIS (Netherlands)

    O. Prevo; P. Leunisse; H. Roest (Henk)

    1999-01-01

    textabstractIn this paper we investigate the mediating role of psychosocial benefits in the customer satisfaction/dissatisfaction formation process. Most research on this subject deals with the causality direction of psychosocial benefits and satisfaction, sometimes preceded by an overall functional

  3. Formation of a Methodological Approach to Evaluating the State of Management of Enterprise Flow Processes

    Directory of Open Access Journals (Sweden)

    Dzobko Iryna P.

    2016-02-01

    Full Text Available The formation of a methodological approach to evaluating management of the state of enterprise flow processes has been considered. Proceeding from the developed and presented in literary sources theoretical propositions on organization of management of enterprise flow processes, the hypothesis of the study is correlation of quantitative and qualitative evaluations of management effectiveness and formation of the integral index on their basis. The article presents stages of implementation of a methodological approach to evaluating the state of management of enterprise flow processes, which implies indicating the components, their characteristics and methods of research. The composition of indicators, on the basis of which it is possible to evaluate effectiveness of management of enterprise flow processes, has been determined. Grouping of such indicators based on the flow nature of enterprise processes has been performed. The grouping of indicators is justified by a pairwise determination of canonical correlations between the selected groups (the obtained high correlation coefficients confirmed the author’s systematization of indicators. It is shown that a specificity of the formation of a methodological approach to evaluating the state of management of enterprise flow processes requires expansion in the direction of aggregation of the results and determination of factors that influence effectiveness of flow processes management. The article carries out such aggregation using the factor analysis. Distribution of a set of objects into different classes according to the results of the cluster analysis has been presented. To obtain an integral estimation of effectiveness of flow processes management, the taxonomic index of a multidimensional object has been built. A peculiarity of the formed methodological approach to evaluating the state of management of enterprise flow processes is in the matrix correlation of integral indicators calculated on

  4. The critical power to maintain thermally stable molecular junctions

    Science.gov (United States)

    Wang, Yanlei; Xu, Zhiping

    2014-07-01

    With the rise of atomic-scale devices such as molecular electronics and scanning probe microscopies, energy transport processes through molecular junctions have attracted notable research interest recently. In this work, heat dissipation and transport across diamond/benzene/diamond molecular junctions are explored by performing atomistic simulations. We identify the critical power Pcr to maintain thermal stability of the junction through efficient dissipation of local heat. We also find that the molecule-probe contact features a power-dependent interfacial thermal resistance RK in the order of 109 kW-1. Moreover, both Pcr and RK display explicit dependence on atomic structures of the junction, force and temperature. For instance, Pcr can be elevated in multiple-molecule junctions, and streching the junction enhances RK by a factor of 2. The applications of these findings in molecular electronics and scanning probing measurements are discussed, providing practical guidelines in their rational design.

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

    Energy Technology Data Exchange (ETDEWEB)

    Amdursky, Nadav; Gazit, Ehud [Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978 (Israel); Rosenman, Gil, E-mail: gilr@eng.tau.ac.il [School of Electrical Engineering, Iby and Aladar Fleischman, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978 (Israel)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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 μg/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.

  7. GENDER ORIENTATION FORMATION FEATURES OF YOUNGER PUPILS IN THE EDUCATIONAL PROCESS

    Directory of Open Access Journals (Sweden)

    Yulia V. KURBATOVA

    2015-01-01

    Full Text Available In the modern Russian society modernization of education, accompanied by a rethinking, re-evaluating and adopting new values and orientations. Significant changes have affected and General education, in which the system-activity approach is crucial. The subject of study in this paper is the development of gender orientations of younger students in the educational process. In the process of research used complex methods of research: analysis of scientific literature on the research problem, theoretical analysis and synthesis of interview and participant observation. Scientific novelty consists in the fact that the essence of gender identity and the features of its formation in primary school; the pedagogical potential of management of development of gender orientations of younger students in the educational process. Conducted scientific study of the problem of formation of a gender orientations of younger students in the educational process due to the value of a healthy gender identity to the full development of the person. An empirical study of gender identity younger students showed the existence of problems of formation of a gender orientations in the educational process. Most younger students recorded a rigid gender identity. 

  8. Curcumin complexation with cyclodextrins by the autoclave process: Method development and characterization of complex formation.

    Science.gov (United States)

    Hagbani, Turki Al; Nazzal, Sami

    2017-03-30

    One approach to enhance curcumin (CUR) aqueous solubility is to use cyclodextrins (CDs) to form inclusion complexes where CUR is encapsulated as a guest molecule within the internal cavity of the water-soluble CD. Several methods have been reported for the complexation of CUR with CDs. Limited information, however, is available on the use of the autoclave process (AU) in complex formation. The aims of this work were therefore to (1) investigate and evaluate the AU cycle as a complex formation method to enhance CUR solubility; (2) compare the efficacy of the AU process with the freeze-drying (FD) and evaporation (EV) processes in complex formation; and (3) confirm CUR stability by characterizing CUR:CD complexes by NMR, Raman spectroscopy, DSC, and XRD. Significant differences were found in the saturation solubility of CUR from its complexes with CD when prepared by the three complexation methods. The AU yielded a complex with expected chemical and physical fingerprints for a CUR:CD inclusion complex that maintained the chemical integrity and stability of CUR and provided the highest solubility of CUR in water. Physical and chemical characterizations of the AU complexes confirmed the encapsulated of CUR inside the CD cavity and the transformation of the crystalline CUR:CD inclusion complex to an amorphous form. It was concluded that the autoclave process with its short processing time could be used as an alternate and efficient methods for drug:CD complexation. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Void formation in Nb3Sn-Cu superconducting wire produced by the external tin process

    Science.gov (United States)

    Verhoeven, J. D.; Efron, A.; Gibson, E. D.; Cheng, C. C.

    1986-03-01

    The tin (Sn) diffusion step for producing Nb3Sn-Cu superconducting wire by the external Sn process was modeled in experiments where either pure Sn or a Cu-Sn alloy was plated on sheets of either pure Cu or a Cu-Sn bronze. Each stage of the three-stage solid-state diffusion process was evaluated and it was found that rows of voids are produced in stage I of the process. These voids coarsen in stages II and III and in the worst case they are observed to coalesce and cause complete spalling away of the Sn-rich diffusion layers. Methods for minimizing void formation and possible causes of the void formation are discussed.

  10. The Process of TiB2-Cu Composite Phase and Structure Formation during Combustion Synthesis

    Institute of Scientific and Technical Information of China (English)

    XU Qiang; ZHANG Xinghong; HAN Jiecai; PAN Wei

    2006-01-01

    The reaction process of combustion synthesis for TiB2- Cu was investigated in detail using combustion-wave arresting experiment, X-ray diffraction (XRD) analysis, SEM analysis and differential thermal analysis ( DTA ). The XRD analysis results for the different parts of the quenched specimen shaw that TiCux intermetallic phase firstly forms with the propagation of combustion wave, and then Ti1.87 B50 and Ti3 B4 metastable phases come forth due to the diffusion of B atoms and finally the stable TiB2 phase forms because of the continuous diffusion of B atoms. The formation of TiB2 phase is not completed by one step, but undergoes several transient processes. The process of reaction synthesis for Ti-B-Cu ternary system can be divided into three main stages: melting of Cu and Ti, and the formation of Cu- Ti melt and few TiCux , TiBx intermetallic phases; large numbers of TiCux intermetallic phases formation and some fine TiB2 particles precipitation; and the TiB2 particles coarsening and the stable TiB2 and Cu two phases formation in the final product.

  11. Automation benefits in the formation process of lead-acid batteries

    Directory of Open Access Journals (Sweden)

    Márcio Duarte Zanconato

    2017-03-01

    Full Text Available In this work, the automated formation process of lead-acid battery and its industrial positive impact on the battery efficiency are evaluated toward the manual process. The problems in the lead-acid batteries formation are related to the α-PbO2 and β-PbO2 production during the first electric charge. The lead-acid battery formation problems frequently occur when electrical current sources with manual control are used. The main drawback of the manual method is addressed to the electric current interruptions between the plates during the battery charging. Thus, the lead oxides phases in the plates were used as parameter to correlate the chemical composition to the failure on the batteries formation process. X-ray powder diffraction technique was used to identify the lead phases. The results showed that the use of automated electric power supply has higher efficiency than the manual one. The benefits of automation include the increased productivity, reduction on the production costs, and lower consumption of natural resources.

  12. The general mechanisms of Cu cluster formation in the processes of condensation from the gas phase

    Indian Academy of Sciences (India)

    I V Chepkasov; Yu Ya Gafner; S L Gafner; S P Bardakhanov

    2015-06-01

    Technological applications of metallic clusters impose very strict requirements for particle size, shape, structure and defect density. Such geometrical characteristics of nanoparticles are mainly determined by the process of their growth. This work represents the basic mechanisms of cluster formation from the gas phase that has been studied on the example of copper. The process of Cu nanoclusters synthesis has been studied by the moleculardynamics method based on tight-binding potentials. It has been shown that depending on the size and temperature of the initial nanoclusters the process of nanoparticle formation can pass through different basic scenarios. The general conditions of different types of particles formation have been defined and clear dependence of the cluster shape from collision temperature of initial conglomerates has been shown. The simulation results demonstrate a very good agreement with the available experimental data. Thus, it has been shown that depending on the specific application of the synthesized particles or in electronics, where particles of a small size with a spherical shape are required, or in catalytic reactions, where the main factor of effectiveness is the maximum surface area with the help of temperature of the system it is possible to get the realization of a certain frequency of this or that scenario of the shape formation of nanocrystalline particles.

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

    Science.gov (United States)

    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.

  14. Modeling of the process of heat transfer formation during steam flooding

    Energy Technology Data Exchange (ETDEWEB)

    Malofeev, G.E.; Sheinman, A.B.; Kennavi, F.A.

    1971-01-01

    This work describes experimental data on distribution of temperature in a formation and loss of heat during radial flow of saturated steam. The problem is formulated mathematically and dimensionless parameters characterizing the process are described. The study also throws light on laboratory equipment, experimental techniques and the results obtained. Experimental data are compared with calculated values. The results can be used for evaluating thermal phenomena in high temperature formations in the presence of natural convection and for determining temperature distribution in the case of artificial steam injection. (14 refs.)

  15. Formation Mechanism and Exhumation Processes for HP-UHP Metamorphic Rocks in Dabie Mountains

    Institute of Scientific and Technical Information of China (English)

    Hou Mingjin; Tang Jiafu

    2004-01-01

    The high, ultrahigh pressure metamorphic rocks, widely distributed in Dabie Mountains, were described in terms of the geological setting, the marks of the petrology and the mineralogy of the ultrahigh pressure (UHP) metamorphic rocks. According to the estimated uplifting and denudation of the Dabie Mountains, and to the thermodynamics theory, were assessed the depth and pressure (high pressure autoclave) of the formation setting of the UHP metamorphic rocks. Based on all the information mentioned above, a new explanation is derived from the mechanism of formation and the processes of exhumation of the UHP metamorphic rocks.

  16. Avrami behavior of magnetite nanoparticles formation in co-precipitation process

    Directory of Open Access Journals (Sweden)

    Ahmadi R.

    2011-01-01

    Full Text Available In this work, magnetite nanoparticles (mean particle size about 20 nm were synthesized via coprecipitation method. In order to investigate the kinetics of nanoparticle formation, variation in the amount of reactants within the process was measured using pH-meter and atomic absorption spectroscopy (AAS instruments. Results show that nanoparticle formation behavior can be described by Avrami equations. Transmission electron microscopy (TEM and X-ray diffraction (XRD were performed to study the chemical and morphological characterization of nanoparticles. Some simplifying assumptions were employed for estimating the nucleation and growth rate of magnetite nanoparticles.

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

    Science.gov (United States)

    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.

  18. Thermal Diffusion Processes in Metal-Tip-Surface Interactions: Contact Formation and Adatom Mobility

    DEFF Research Database (Denmark)

    Sørensen, Mads Reinholdt; Jacobsen, Karsten Wedel; Jonsson, Hannes

    1996-01-01

    We have carried out computer simulations to identify and characterize various thermally activated atomic scale processes that can play an important role in room temperature experiments where a metal tip is brought close to a metal surface. We find that contact formation between the tip...... and the surface can occur by a sequence of atomic hop and exchange processes which become active on a millisecond time scale when the tip is about 3-5 Angstrom from the surface. Adatoms on the surface are stabilized by the presence of the tip and energy barriers for diffusion processes in the region under the tip...

  19. Statistical Behavior of Formation Process of Magnetic Vortex State in Ni80Fe20 Nanodisks

    Energy Technology Data Exchange (ETDEWEB)

    Im, Mi-Young; Fischer, Peter; Keisuke, Yamada; Kasai, Shinya

    2011-01-14

    Magnetic vortices in magnetic nanodots, which are characterized by an in-plane (chirality) and an out-of-plane (polarity) magnetizations, have been intensively attracted because of their high potential for technological application to data storage and memory scheme as well as their scientific interest for an understanding of fundamental physics in magnetic nanostructures. Complete understanding of the formation process of vortex state in magnetic vortex systems is very significant issue to achieve storage and memory technologies using magnetic vortices and understand intrinsic physical properties in magnetic nanostructures. In our work, we have statistically investigated the formation process of vortex state in permalloy (Py, Ni{sub 80}Fe{sub 20}) nanodisks through the direct observation of vortex structure utilizing a magnetic transmission soft X-ray microscopy (MTXM) with a high spatial resolution down to 20 nm. Magnetic imaging in Py nanodots was performed at the Fe L{sub 3} (707 eV) absorption edge. Figure 1 shows in-plane and out-of-plane magnetic components observed in 40 nm thick nanodot arrays with different dot radius of r = 500 and 400 nm, respectively. Vortex chirality, either clockwise (CW) or counter-clockwise (CCW), and polarity, either up or down, are clearly visible in both arrays. To investigate the statistical behavior in formation process of the vortex state, the observation of vortex structure at a remanant state after saturation of nanodots by an external magnetic field of 1 kOe has been repeatedly performed over 100 times for each array. The typical MTXM images of vortex chirality taken in two successive measurements together with their overlapped images in nanodot arrays of r = 500 and 400 nm are displayed in Fig. 2. Within the statistical measurement, the formation process of chirality of either CW or CCW is quite stochastic in each nanodot. Similar behavior is also witnessed in the formation of vortex polarity observed in consecutive

  20. Have a break: determinants of meiotic DNA double strand break (DSB) formation and processing in plants.

    Science.gov (United States)

    Edlinger, Bernd; Schlögelhofer, Peter

    2011-03-01

    Meiosis is an essential process for sexually reproducing organisms, leading to the formation of specialized generative cells. This review intends to highlight current knowledge of early events during meiosis derived from various model organisms, including plants. It will particularly focus on cis- and trans-requirements of meiotic DNA double strand break (DSB) formation, a hallmark event during meiosis and a prerequisite for recombination of genetic traits. Proteins involved in DSB formation in different organisms, emphasizing the known factors from plants, will be introduced and their functions outlined. Recent technical advances in DSB detection and meiotic recombination analysis will be reviewed, as these new tools now allow analysis of early meiotic recombination in plants with incredible accuracy. To anticipate future directions in plant meiosis research, unpublished results will be included wherever possible.

  1. Formulation of Non-steady-state Dust Formation Process in Astrophysical Environments

    Science.gov (United States)

    Nozawa, Takaya; Kozasa, Takashi

    2013-10-01

    The non-steady-state formation of small clusters and the growth of grains accompanied by chemical reactions are formulated under the consideration that the collision of key gas species (key molecule) controls the kinetics of dust formation process. The formula allows us to evaluate the size distribution and condensation efficiency of dust formed in astrophysical environments. We apply the formulation to the formation of C and MgSiO3 grains in the ejecta of supernovae, as an example, to investigate how the non-steady effect influences the formation process, condensation efficiency f con, ∞, and average radius a ave, ∞ of newly formed grains in comparison with the results calculated with the steady-state nucleation rate. We show that the steady-state nucleation rate is a good approximation if the collision timescale of key molecule τcoll is much smaller than the timescale τsat with which the supersaturation ratio increases; otherwise the effect of the non-steady state becomes remarkable, leading to a lower f con, ∞ and a larger a ave, ∞. Examining the results of calculations, we reveal that the steady-state nucleation rate is applicable if the cooling gas satisfies Λ ≡ τsat/τcoll >~ 30 during the formation of dust, and find that f con, ∞ and a ave, ∞ are uniquely determined by Λon at the onset time t on of dust formation. The approximation formulae for f con, ∞ and a ave, ∞ as a function of Λon could be useful in estimating the mass and typical size of newly formed grains from observed or model-predicted physical properties not only in supernova ejecta but also in mass-loss winds from evolved stars.

  2. Applications of all optical signal processing for advanced optical modulation formats

    Science.gov (United States)

    Nuccio, Scott R.

    signal processing may play a role in the future development of more efficient optical transmission systems. The hope is that performing signal processing in the optical domain may reduce optical-to-electronic conversion inefficiencies, eliminate bottlenecks and take advantage of the ultrahigh bandwidth inherent in optics. While 40 to 50 Gbit/s electronic components are the peak of commercial technology and 100 Gbit/s capable RF components are still in their infancy, optical signal processing of these high-speed data signals may provide a potential solution. Furthermore, any optical processing system or sub-system must be capable of handling the wide array of data formats and data rates that networks may employ. It is also worth noting that future networks may use a combination of data-rates and formats while it has been estimated that "we may start seeing the first commercial use of Terabit Ethernets by 2015". -Robert Metcalfe. To this end, the work presented in this Ph.D. dissertation is aimed at addressing the issue of optical processing for advanced optical modulation formats. All optical multiplexing and demultiplexing of Pol-MUX and phase and QAM encoded signals at the 100 Gbit/s Ethernet standard is addressed. The creation and development of an extremely large continuously tunable all-optical delay capable of handling a variety of modulation formats and data rates is presented. As optical delays are viewed as a critical element to achieve efficient and reconfigurable signal processing, the presented delay line is also utilized to enable a tunable packet buffer capable of handling data packets of varying rate, varying size, and multiple modulation formats.

  3. Motivational influences on impression formation: outcome dependency, accuracy-driven attention, and individuating processes.

    Science.gov (United States)

    Neuberg, S L; Fiske, S T

    1987-09-01

    How might being outcome dependent on another person influence the processes that one uses to form impressions of that person? We designed three experiments to investigate this question with respect to short-term, task-oriented outcome dependency. In all three experiments, subjects expected to interact with a young man formerly hospitalized as a schizophrenic, and they received information about the person's attributes in either written profiles or videotapes. In Experiment 1, short-term, task-oriented outcome dependency led subjects to use relatively individuating processes (i.e., to base their impressions of the patient on his particular attributes), even under conditions that typically lead subjects to use relatively category-based processes (i.e., to base their impressions on the patient's schizophrenic label). Moreover, in the conditions that elicited individuating processes, subjects spent more time attending to the patient's particular attribute information. Experiment 2 demonstrated that the attention effects in Experiment 1 were not merely a function of impression positivity and that outcome dependency did not influence the impression formation process when attribute information in addition to category-level information was unavailable. Finally, Experiment 3 manipulated not outcome dependency but the attentional goal of forming an accurate impression. We found that accuracy-driven attention to attribute information also led to individuating processes. The results of the three experiments indicate that there are important influences of outcome dependency on impression formation. These results are consistent with a model in which the tendency for short-term, task-oriented outcome dependency to facilitate individuating impression formation processes is mediated by an increase in accuracy-driven attention to attribute information.

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

    Science.gov (United States)

    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.

  5. High-throughput process development of chromatography steps: advantages and limitations of different formats used.

    Science.gov (United States)

    Łącki, Karol M

    2012-10-01

    In the past, development of a chromatographic separation method has been accomplished by performing a series of experiments using either manual or automated chromatography systems. The screening of a vast experimental space became very expensive because all experiments had to be performed in a serial manner, and the chromatography systems used were designed for relatively large columns and, therefore, the experiments required large sample volumes. To address these issues, high-throughput miniaturized methods employing different operating principles and/or formats have been introduced. Herein, a technical review of the most common high-throughput formats used for the development of chromatographic purification steps is presented. The formats considered include minicolumns, prefilled pipette tips, and microtiter filter plates prefilled with chromatography resins. Advantages and limitations of each format are discussed through the prism of chromatographic theory, engineering principles, and known mass-transfer mechanisms. A roadmap for applicability of the different formats for process development purposes and implementation of a Quality by Design initiative for designing/optimization of chromatography steps is also discussed.

  6. Transcriptomic analysis of the process of biofilm formation in Rhizobium etli CFN42.

    Science.gov (United States)

    Reyes-Pérez, Agustín; Vargas, María Del Carmen; Hernández, Magdalena; Aguirre-von-Wobeser, Eneas; Pérez-Rueda, Ernesto; Encarnacion, Sergio

    2016-11-01

    Organisms belonging to the genus Rhizobium colonize leguminous plant roots and establish a mutually beneficial symbiosis. Biofilms are structured ecosystems in which microbes are embedded in a matrix of extracellular polymeric substances, and their development is a multistep process. The biofilm formation processes of R. etli CFN42 were analyzed at an early (24-h incubation) and mature stage (72 h), comparing cells in the biofilm with cells remaining in the planktonic stage. A genome-wide microarray analysis identified 498 differentially regulated genes, implying that expression of ~8.3 % of the total R. etli gene content was altered during biofilm formation. In biofilms-attached cells, genes encoding proteins with diverse functions were overexpressed including genes involved in membrane synthesis, transport and chemotaxis, repression of flagellin synthesis, as well as surface components (particularly exopolysaccharides and lipopolysaccharides), in combination with the presence of activators or stimulators of N-acyl-homoserine lactone synthesis This suggests that R. etli is able to sense surrounding environmental conditions and accordingly regulate the transition from planktonic and biofilm growth. In contrast, planktonic cells differentially expressed genes associated with transport, motility (flagellar and twitching) and inhibition of exopolysaccharide synthesis. To our knowledge, this is the first report of nodulation and nitrogen assimilation-related genes being involved in biofilm formation in R. etli. These results contribute to the understanding of the physiological changes involved in biofilm formation by bacteria.

  7. Formulation of Non-steady-state Dust Formation Process in Astrophysical Environments

    CERN Document Server

    Nozawa, Takaya

    2013-01-01

    The non-steady-state formation of small clusters and the growth of grains accompanied by chemical reactions are formulated under the consideration that the collision of key gas species (key molecule) controls the kinetics of dust formation process. The formula allows us to evaluate the size distribution and condensation efficiency of dust formed in astrophysical environments. We apply the formulation to the formation of C and MgSiO3 grains in the ejecta of supernovae, as an example, to investigate how the non-steady effect influences the formation process, condensation efficiency f_{con}, and average radius a_{ave} of newly formed grains in comparison with the results calculated with the steady-state nucleation rate. We show that the steady-state nucleation rate is a good approximation if the collision timescale of key molecule tau_{coll} is much smaller than the timescale tau_{sat} with which the supersaturation ratio increases; otherwise the effect of the non-steady state becomes remarkable, leading to a lo...

  8. Junction trees of general graphs

    Institute of Scientific and Technical Information of China (English)

    Xiaofei WANG; Jianhua GUO

    2008-01-01

    In this paper,we study the maximal prime subgraphs and their corresponding structure for any undirected graph.We introduce the notion of junction trees and investigate their structural characteristics,including junction properties,induced-subtree properties,running-intersection properties and maximum-weight spanning tree properties.Furthermore,the characters of leaves and edges on junction trees are discussed.

  9. Depression and the impression-formation continuum: piecemeal processing despite the availability of category information.

    Science.gov (United States)

    Edwards, J A; Weary, G

    1993-04-01

    A study explored depressed-nondepressed differences in impression formation. From S. T. Fiske and S. L. Neuberg's (1990) model of impression formation, mildly depressed perceivers were hypothesized to engage in more piecemeal processing when forming an impression of a target other, even when nondepressed perceivers would typically use less effortful, categorical processing. With an idiographic technique designed by M. Pavelchak (1989), depressed Ss were shown to use trait attributes in evaluating a person, even when induced to categorize the individual. Nondepressed Ss relied on category information when available, replicating Pavelchak's study. Depressed Ss' results are interpreted as arising from a motivation to engage in effortful analysis of social information, stemming from feelings of lack of control over life events.

  10. Nanoparticle formation in the expansion process of a laser ablated plume

    Energy Technology Data Exchange (ETDEWEB)

    Takiya, T [Hitachi Zosen Corporation, Taisho-ku, Osaka 551-0022 (Japan); Umezu, I [Konan University, Higashinada-ku, Kobe 658-8501 (Japan); Yaga, M [University of the Ryukyus, Nishihara, Okinawa 903-0213 (Japan); Han, M [Nanjing University, Nanjing 210093 (China)

    2007-04-15

    In the present article, we describe the process of nanoparticle formation during pulsed laser ablation in an inert gas atmosphere. We investigated the interaction between laser ablated plumes and shock waves using one dimensional Eulerian fluid dynamics equations combined with a rate equation relating to a classical nucleation model of supersaturated vapors. The initial values for the plume immediately after laser irradiation onto a silicon target were calculated based on stochastic thermodynamics, which was first used by Houle et al. We found a certain case wherein the rate of nanoparticle formation becomes higher when a reflected shock wave passes through the plume. In that particular case, mono-dispersed nanoparticles can be generated by carrying out nucleation and nanoparticle growth as separate processes.

  11. PROPOSITION OF A SYSTEMATIC EVALUATION OF LEARNING FOR MANAGERS FORMATION BASED ON MANAGERIAL PROCESS

    Directory of Open Access Journals (Sweden)

    Chiara da Silva Simões

    2013-12-01

    Full Text Available Managers are the outcomes of production systems rationality designed. The manager as outcome is a mix of knowledge, skills and behavior pattern whose utility is directly proportional to the consistency of your professional formation, just the production systems rationality designed. Thus, this paper aims to present a systematic evaluation of learning based on managerial process functions: planning, organization, directing and control. It consist of ten steps: definition of knowledge to be evaluate; definition of skills to be evaluate; choosing of test framework; writing of questions; definition of test solution norms; evaluation pre-test; testing; organization of data; evaluation of results; and analyzing the causes of failure and replanning. The results show that manager formation process can be optimized if higher education institutions use the system in accordance with the course objectives.

  12. The information technologies in the initial formation process of the professional of education.

    Directory of Open Access Journals (Sweden)

    Oliurca Padilla García

    2012-12-01

    Full Text Available Universities should give the students methods, aids and ways to obtain knowledge, in correspondence with the scientific development reached, so that they can assume a transformer position in the different acting contexts. In this sense, the information technologies not only provide the student with tools and resources of information, but also propitiate an environment that promotes interactions and educative exchange experiences between the students and teachers. Deepening about the role these resources play in the educational environment is of great importance to get its integration in a systematic and systemic way to the initial formation process of the professional of education so, its application in their formation surpasses the traditional concept of using de aims, and becomes an element that significantly strikes in a new configuration of the didactic approach of the process in the nowadays conditions.

  13. EXPERIMENTALLY-STATISTICAL MODEL OF CLADDING LAYER FORMATION PROCESS ON SLIDE-WAYS

    Directory of Open Access Journals (Sweden)

    N. N. Maksimchenko

    2010-01-01

    Full Text Available The developed experimentally-statistical model of the cladding composite layer formation process on slide-ways allows to operate technological modes of cladding by flexible instrument (CFI in order to obtain the set properties of a coating (thickness, continuity, adhesion strength.The established optimum technological modes of CFI process providing formation of continuous, strongly adhered to a basis composite coatings of the required thickness have been used for applying coatings on working surfaces of slide-ways of metal-cutting machine tool beds that has allowed to lower friction factor in coupling on the average by 1.3–1.7-fold and to improve uniformity of slow moving of machine tool units by 1.74-fold in comparison with slide-ways without a coating. 

  14. Deuteration and evolution in the massive star formation process: the role of surface chemistry

    OpenAIRE

    Fontani, F.; Busquet, G.; Palau, Aina; Caselli, P.; Van, A; Sanchez-Monge; Tan, J. C.; Audard, M.

    2014-01-01

    An ever growing number of observational and theoretical evidence suggests that the deuterated fraction (column density ratio between a species containing D and its hydrogenated counterpart, Dfrac) is an evolutionary indicator both in the low- and the high-mass star formation process. However, the role of surface chemistry in these studies has not been quantified from an observational point of view. In order to compare how the deuterated fractions of species formed only in the gas and partiall...

  15. Invited presentation:'Synchrotron Methods to Reveal Chemical Processes at Interfaces During Material Formation and Transformation'

    OpenAIRE

    Breynaert, Eric

    2016-01-01

    Material chemistry depends on interdisciplinary research targeting design, (trans-) formation, structure analysis and application of materials and minerals. Insight in the chemical processes occurring at interfaces not only enables design and synthesis of new technologically attractive structures, but also provides key information for a score of other research fields with direct impact on our daily lives. X-ray based techniques play a key role as they provide essential information...

  16. Logic of historical development of the formation process of architectural and construction solutions

    OpenAIRE

    Baranov Valeriy Aleksandrovich

    2014-01-01

    In research field of development processes of architectural and construction decisions (ACD) there is already very considerable scientific, normative and technical material. And still in the end of the research boom in this area (the 90th) many authors stated their weak return in practical design. High methodological potential gives understanding of the act of ACD formation as a special kind of activity, and its structure - as historical phenomenon that allows to put two main methodological p...

  17. Formation of CuInS{sub 2}-carbon multilayers in the spray ILGAR process

    Energy Technology Data Exchange (ETDEWEB)

    Camus, Christian; Abou-Ras, Daniel; Allsop, Nicholas A.; Gledhill, Sophie E.; Koehler, Tristan; Lauermann, Iver; Lux-Steiner, Martha C.; Fischer, Christian-Herbert [Helmholtz Zentrum Berlin fuer Materialien und Energie, Glienicker Str. 100, 14109 Berlin (Germany); Rappich, Joerg [Helmholtz Zentrum Berlin fuer Materialien und Energie, Kekulestr. 5, 12489 Berlin (Germany)

    2010-01-15

    In this paper, the incorporation of carbon into CuInS{sub 2} (CIS) thin films is described as observed in spray ion layer gas reaction (ILGAR) deposition of such thin films. It is shown that this carbon incorporation leads to the formation of a CIS-carbon multilayer stack. Its growth mechanism is explained by the interaction of the copper and indium precursor compounds used in the deposition process. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  18. Children's processing of new advertising formats: how to improve children's dispositional and situational advertising literacy?

    OpenAIRE

    Hudders, Liselot; De Pauw, Pieter; Cauberghe, Veroline; Panic, Katarina; Zarouali, Brahim

    2015-01-01

    Compared to traditional advertising formats, contemporary advertising is characterized by a more subtle, less intrusive commercial nature. Commercial messages are now frequently integrated in or merged with highly entertaining and fun media content, which distract the users from systematically and critically processing the content. This makes it difficult for consumers, especially young consumers with limited advertising literacy, to evaluate the persuasion attempt critically. Not only do...

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

    Science.gov (United States)

    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. Copyright © 2014 Elsevier B.V. All rights

  20. Analysis and evaluation in the production process and equipment area of the Low-Cost Solar Array Project. Quarterly report, January-April 1979

    Energy Technology Data Exchange (ETDEWEB)

    Goldman, H.; Wolf, M.

    1979-06-01

    Significant economic and technical data on the current front junction formation processes of Spectrolab's gaseous diffusion, and of involving the Varian-Extrion 200 to 1000 implanter were tabulated, and were used to judge the feasibility of diffusion proposals by Motorola and RCA and ion implantation proposals by Lockheed, Motorola, RCA, and Spire to meet future LSA-JPL guidelines. Cost calculations, consistent with the SAMICS methodology, were performed for the junction formation processes studied.

  1. Formation process of liquid in interface of Ti/Cu contact reaction couple

    Institute of Scientific and Technical Information of China (English)

    WU Ming-fang; YU Chun; YU Zhi-shi; LI Rui-feng

    2005-01-01

    By using the Ti/Cu contact reaction couples,the dissolution behavior of Ti and Cu in the eutectic reaction process was investigated under different conditions.The results show that the formation of eutectic liquid phase has a directional property,I.e.the eutectic liquid phase forms first at the Cu side and then spreads along the depth direction of Cu.The width of the eutectic liquid zone when Ti is placed on Cu is wider than that when Ti is placed under Cu.The shape of the upside liquid zone is wave-like.This phenomenon indicates that the formation process and spreading behavior in the upside are different from those in the underside,and there exists void effect in the Cu side of underside liquid zone,this will result in the delaying phenomenon of the contact reaction between Ti and Cu,and distinctly different shapes of the both liquid zones.The formation process of Ti/Cu eutectic liquid zone is similar to that of the traditional solid-state diffusion layer,and the relationship between the width of liquid zone and holding time obeys a square root law.

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

    Science.gov (United States)

    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.

  3. Characterization of aquatic humic substances to DBPs formation in advanced treatment processes for conventionally treated water.

    Science.gov (United States)

    Kim, Hyun-Chul; Yu, Myong-Jin

    2007-05-01

    An advanced water treatment demonstration plant consisted of ozone/granular activated carbon processes was operated to study feasibility of the processes. Natural organic matter (NOM) from raw and process waters at the demonstration plant was isolated into humic and non-humic fractions by physicochemical fractionation method to investigate characteristics of humic fraction (i.e., humic substances, HS) as a predominant haloform reactant. Ozone did not significantly oxidize the carboxylic fraction (from 39.1 to 35.9%), while GAC removed some of the carboxylic fraction (from 35.9 to 29.1%). Formation potential of trihalomethanes (THMs) as compared to haloacetic acids formation potential (HAAFP) was highly influenced by HS. Higher yields of THMs resulted from chlorination of HS with a higher phenolic content and phenolic fraction in the HS gradually decreased from 60.5% to 15.8% through the water treatment. The structural and functional changes of HS were identified by elemental, Fourier-transform infrared (FT-IR) and proton nuclear magnetic resonance ((1)H NMR) analyses, and these results were mutually consistent. The functional distribution data obtained by using A-21 resin could be used to support the interpretation of data obtained from the spectroscopic analyses. Decreases in ratio of UV absorbance at 253 nm and 203 nm (A(253)/A(203)) and DBPFPs/DOC showed consistent trends, therefore, A(253)/A(203) ratio may be a good indicator for the disinfection by-product formation potentials (DBPFPs).

  4. Understanding nanoparticle formation by a wire explosion process through experimental and modelling studies

    Science.gov (United States)

    Sindhu, T. K.; Sarathi, R.; Chakravarthy, S. R.

    2008-01-01

    A wire explosion process (WEP) has been used to produce nano aluminium powder in nitrogen, argon and helium atmospheres. The impact of energy deposited into the exploding conductor on the size and shape of the particles was analysed using TEM analysis, which forms the first part of the study. It is observed that the higher the energy deposited, the smaller the particles formed. In the second part, modelling studies were carried out by solving the general dynamic equation through the nodal approach, and the particle size distributions were predicted. It is realized that, at the point of high saturation ratio and nucleation rate, the size of the critical nucleus formed is low. The particle size distribution predicted by the model correlates well with the experimental results. Time-series analysis of particle formation indicates that particles of lower dimensions form and, in the process of coagulation, larger particles are formed. It is realized that the plasma formed during the explosion plays a major role in the particle formation, and the modelling studies confirm that particle formation is not an instantaneous process but requires a certain time period to form stable sizes and shapes.

  5. Effect of solvent type on the nanoparticle formation of atorvastatin calcium by the supercritical antisolvent process.

    Science.gov (United States)

    Kim, Min-Soo; Song, Ha-Seung; Park, Hee Jun; Hwang, Sung-Joo

    2012-01-01

    The aims of this study were to identify how the solvent selection affects particle formation and to examine the effect of the initial drug solution concentration on mean particle size and particle size distribution in the supercritical antisolvent (SAS) process. Amorphous atorvastatin calcium was precipitated from seven different solvents using the SAS process. Particles with mean particle size ranging between 62.6 and 1493.7 nm were obtained by varying organic solvent type and solution concentration. By changing the solvent, we observed large variations in particle size and particle size distribution, accompanied by different particle morphologies. Particles obtained from acetone and tetrahydrofuran (THF) were compact and spherical fine particles, whereas those from N-methylpyrrolidone (NMP) and dimethylsulfoxide (DMSO) were agglomerated, with rough surfaces and relatively larger particle sizes. Interestingly, the mean particle size of atorvastatin calcium increased with an increase in the boiling point of the organic solvent used. Thus, for atorvastatin particle formation via the SAS process, particle size was determined mainly by evaporation of the organic solvent into the antisolvent phase. In addition, the mean particle size was increased with increasing drug solution concentration. In this study, from the aspects of particle size and solvent toxicity, acetone was the better organic solvent for controlling nanoparticle formation of atorvastatin calcium.

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

    Science.gov (United States)

    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.

  7. Silicon fiber with p-n junction

    Energy Technology Data Exchange (ETDEWEB)

    Homa, D.; Cito, A.; Pickrell, G.; Hill, C.; Scott, B. [Department of Materials Science and Engineering, Virginia Polytechnic Institute and State University, 312 Holden Hall, Blacksburg, Virginia 24060 (United States)

    2014-09-22

    In this study, we fabricated a p-n junction in a fiber with a phosphorous doped silicon core and fused silica cladding. The fibers were fabricated via a hybrid process of the core-suction and melt-draw techniques and maintained overall diameters ranging from 200 to 900 μm and core diameters of 20–800 μm. The p-n junction was formed by doping the fiber with boron and confirmed via the current-voltage characteristic. The demonstration of a p-n junction in a melt-drawn silicon core fiber paves the way for the seamless integration of optical and electronic devices in fibers.

  8. Evaluating evaluation as a communication process. What role for formative evaluation in ICT-based knowledge acquisition?

    Directory of Open Access Journals (Sweden)

    USEILLE Philippe

    2005-10-01

    Full Text Available This article examines how formative evaluation as a communication process contributes to knowledge acquisition in using ICT (Information and Communication Technologies. Previous studies, especially in the field of education and training, have shown that formative evaluation plays a crucial part in the learning process because it contributes to learning to learn. Through formative evaluation, the learner becomes aware of errors and can adjust learning strategies to the situation. In addition, formative evaluation provides the teaching side with significant and useful information. Consequently, ICT researches have developed a wide range of solutions for this specific purpose. It is however difficult to check the efficiency of these tools by considering the effects of ICT in the knowledge acquisition process. I suggest that formative evaluation includes also a communication system that has an effect on the learning process. This study tackles the issue by proposing an alternative approach to formative evaluation that considers it as both a learning and a communication process. The study is based on SADT (Structure Analysis and Design Technique that provides a suitable description for the whole complex communication process. It allows a rigorous understanding and identification of the variables of evaluation as a communication process in order to take care of an ICT frame. Finally, this article outlines a multidisciplinary method to evaluate formative evaluation by focusing on the validity facets of the communication process. Keywords: formative evaluation, communication process, validity criteria, ICT training context.

  9. Bromate Formation Characteristics of UV Irradiation, Hydrogen Peroxide Addition, Ozonation, and Their Combination Processes

    Directory of Open Access Journals (Sweden)

    Naoyuki Kishimoto

    2012-01-01

    Full Text Available Bromate formation characteristics of six-physicochemical oxidation processes, UV irradiation, single addition of hydrogen peroxide, ozonation, UV irradiation with hydrogen peroxide addition (UV/H2O2, ozonation with hydrogen peroxide addition (O3/H2O2, and ozonation with UV irradiation (O3/UV were investigated using 1.88 μM of potassium bromide solution with or without 6.4 μM of 4-chlorobenzoic acid. Bromate was not detected during UV irradiation, single addition of H2O2, and UV/H2O2, whereas ozone-based treatments produced . Hydroxyl radicals played more important role in bromate formation than molecular ozone. Acidification and addition of radical scavengers such as 4-chlorobenzoic acid were effective in inhibiting bromate formation during the ozone-based treatments because of inhibition of hydroxyl radical generation and consumption of hydroxyl radicals, respectively. The H2O2 addition was unable to decompose 4-chlorobenzoic acid, though O3/UV and O3/H2O2 showed the rapid degradation, and UV irradiation and UV/H2O2 showed the slow degradation. Consequently, if the concentration of organic contaminants is low, the UV irradiation and/or UV/H2O2 are applicable to organic contaminants removal without bromate formation. However, if the concentration of organic contaminants is high, O3/H2O2 and O3/UV should be discussed as advanced oxidation processes because of their high organic removal efficiency and low bromate formation potential at the optimum condition.

  10. The energy barrier at noble metal/TiO{sub 2} junctions

    Energy Technology Data Exchange (ETDEWEB)

    Hossein-Babaei, F., E-mail: fhbabaei@kntu.ac.ir, E-mail: fhbabaei@yahoo.com; Lajvardi, Mehdi M., E-mail: mm.lajvardi@gmail.com; Alaei-Sheini, Navid, E-mail: navid-alaei@yahoo.com [Electronic Materials Laboratory, Industrial Control Center of Excellence, Electrical Engineering Department, K. N. Toosi University of Technology, Tehran 16317-14191 (Iran, Islamic Republic of)

    2015-02-23

    Nobel metal/TiO{sub 2} structures are used as catalysts in chemical reactors, active components in TiO{sub 2}-based electronic devices, and connections between such devices and the outside circuitry. Here, we investigate the energy barrier at the junctions between vacuum-deposited Ag, Au, and Pt thin films and TiO{sub 2} layers by recording their electrical current vs. voltage diagrams and spectra of optical responses. Deposited Au/, Pt/, and Ag/TiO{sub 2} behave like contacts with zero junction energy barriers, but the thermal annealing of the reverse-biased devices for an hour at 523 K in air converts them to Schottky diodes with high junction energy barriers, decreasing their reverse electric currents up to 10{sup 6} times. Similar thermal processing in vacuum or pure argon proved ineffective. The highest energy barrier and the lowest reverse current among the devices examined belong to the annealed Ag/TiO{sub 2} contacts. The observed electronic features are described based on the physicochemical parameters of the constituting materials. The formation of higher junction barriers with rutile than with anatase is demonstrated.

  11. Modeling secondary organic aerosol formation through cloud processing of organic compounds

    Directory of Open Access Journals (Sweden)

    J. Chen

    2007-06-01

    Full Text Available Interest in the potential formation of secondary organic aerosol (SOA through reactions of organic compounds in condensed aqueous phases is growing. In this study, the potential formation of SOA from irreversible aqueous-phase reactions of organic species in clouds was investigated. A new proposed aqueous-phase chemistry mechanism (AqChem is coupled with the existing gas-phase Caltech Atmospheric Chemistry Mechanism (CACM and the Model to Predict the Multiphase Partitioning of Organics (MPMPO that simulate SOA formation. AqChem treats irreversible organic reactions that lead mainly to the formation of carboxylic acids, which are usually less volatile than the corresponding aldehydic compounds. Zero-dimensional model simulations were performed for tropospheric conditions with clouds present for three consecutive hours per day. Zero-dimensional model simulations show that 48-h averaged SOA formation are increased by 27% for a rural scenario with strong monoterpene emissions and 7% for an urban scenario with strong emissions of aromatic compounds, respectively, when irreversible organic reactions in clouds are considered. AqChem was also incorporated into the Community Multiscale Air Quality Model (CMAQ version 4.4 with CACM/MPMPO and applied to a previously studied photochemical episode (3–4 August 2004 focusing on the eastern United States. The CMAQ study indicates that the maximum contribution of SOA formation from irreversible reactions of organics in clouds is 0.28 μg m−3 for 24-h average concentrations and 0.60 μg m−3 for one-hour average concentrations at certain locations. On average, domain-wide surface SOA predictions for the episode are increased by 8.6% when irreversible, in-cloud processing of organics is considered.

  12. Vacuum Tight Threaded Junctions (VTTJ): A new solution for reliable heterogeneous junctions in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Agostinetti, P., E-mail: piero.agostinetti@igi.cnr.it; Palma, M. Dalla; Agostini, F. Degli; Marcuzzi, D.; Rizzolo, A.; Rossetto, F.; Sonato, P.; Zaccaria, P.

    2015-10-15

    Highlights: • Heterogeneous junctions represent a critical issue in Nuclear Fusion experiments. • We have developed a new technique for heterogeneous junctions, called VTTJ, whose main advantages are low cost, high reliability and easiness of construction. • The VTTJ junctions have passed all the tests required by ITER for the heterogeneous junctions of the divertor. • Further tests have demonstrated wide margins for operation (up to 700 °C and 500 bar). - Abstract: A new technique, called Vacuum Tight Threaded Junction (VTTJ), has been developed and patented by Consorzio RFX, permitting to obtain low-cost and reliable non-welded junctions, able to maintain vacuum tightness also in heavy loading conditions (high temperature and high mechanical loads). The technique can be applied also if the materials to be joint are not weldable and for heterogeneous junctions (for example, between steel and copper) and has been tested up to 500 bar internal pressure and up to 700 °C, showing excellent leak tightness in vacuum conditions and high mechanical resistance. The main advantages with respect to existing technologies (for example, friction welding and electron beam welding) are an easy construction, a low cost, a precise positioning of the junction and a high repeatability of the process. Due to these advantages, the new technique has been adopted for several components of the SPIDER experiment and it is proposed for ITER, in particular for the ITER Heat and Current Drive Neutral Beam Injector and for its prototype, the MITICA experiment, to be tested at Consorzio RFX. This paper gives a detailed description of the VTTJ technique, of the samples manufactured and of the qualification tests that have been carried out so far.

  13. Edge-Geometry NbN/MgO/NbN Tunnel Junctions

    Science.gov (United States)

    Hunt, Brian D.; Leduc, Henry G.

    1991-01-01

    Superconductor/insulator/superconductor (SIS) tunnel junctions fabricated with base and counter electrodes of NbN separated by thin layers of MgO. Useful as submillimeter-wave mixers and fast switches. Use of edge geometry to define small junction makes possible to fabricate junction by process including conventional photolithography.

  14. Experiments on the interaction between long Josephson junctions and a coplanar strip resonator

    DEFF Research Database (Denmark)

    Davidson, A.; Pedersen, Niels Falsig

    1992-01-01

    Experiments are reported on a new geometry designed to couple long Josephson junction fluxon oscillators to a resonant cavity. The junctions were made with a niobium-aluminum oxide-niobium trilayer process with a critical-current density of around 1000 A/cm2. Various numbers of such junctions wer...

  15. Logic of historical development of the formation process of architectural and construction solutions

    Directory of Open Access Journals (Sweden)

    Baranov Valeriy Aleksandrovich

    2014-05-01

    Full Text Available In research field of development processes of architectural and construction decisions (ACD there is already very considerable scientific, normative and technical material. And still in the end of the research boom in this area (the 90th many authors stated their weak return in practical design. High methodological potential gives understanding of the act of ACD formation as a special kind of activity, and its structure - as historical phenomenon that allows to put two main methodological principles in the basis of the research: the principle of activity and the principle of level organization of historically formed objects. As a result it was succeeded to reveal 6 main stages of historical development of ACD formation process and 6 levels of its modern organization. Origin stage - is the transition from animal to human construction and emergence of the first stage of ACD formation - a measurement. The reproductive stage is characterized by centuries-old reproduction of steady volume forms of constructions. At a composite stage professional presentation detaches external form of a construction from architectural and construction actions and techniques. There occurs transformation into a subject of architectural and construction activity and creation of a method of composition on this basis. At a constructive stage engineers are involved in construction process, there is a change of style of thinking, emergence of construction designs and emergence of a new function of ACD means of configuration, and, at last, final allocation and separation of architectural and construction design from construction. Technological stage is a product of industrialization of construction on which systematization is carried out not only on the level of subject, but also in respect to the operational contents that leads to emergence of ACD program formation. At the sixth, methodological stage of development of ASP, a leading way change of the ACD formation becomes a

  16. Percolation blockage: A process that enables melt pond formation on first year Arctic sea ice

    Science.gov (United States)

    Polashenski, Chris; Golden, Kenneth M.; Perovich, Donald K.; Skyllingstad, Eric; Arnsten, Alexandra; Stwertka, Carolyn; Wright, Nicholas

    2017-01-01

    Melt pond formation atop Arctic sea ice is a primary control of shortwave energy balance in the Arctic Ocean. During late spring and summer, the ponds determine sea ice albedo and how much solar radiation is transmitted into the upper ocean through the sea ice. The initial formation of ponds requires that melt water be retained above sea level on the ice surface. Both theory and observations, however, show that first year sea ice is so highly porous prior to the formation of melt ponds that multiday retention of water above hydraulic equilibrium should not be possible. Here we present results of percolation experiments that identify and directly demonstrate a mechanism allowing melt pond formation. The infiltration of fresh water into the pore structure of sea ice is responsible for blocking percolation pathways with ice, sealing the ice against water percolation, and allowing water to pool above sea level. We demonstrate that this mechanism is dependent on fresh water availability, known to be predominantly from snowmelt, and ice temperature at melt onset. We argue that the blockage process has the potential to exert significant control over interannual variability in ice albedo. Finally, we suggest that incorporating the mechanism into models would enhance their physical realism. Full treatment would be complex. We provide a simple temperature threshold-based scheme that may be used to incorporate percolation blockage behavior into existing model frameworks.

  17. AA6082 to DX56-Steel Laser Brazing: Process Parameter-Intermetallic Formation Correlation

    Science.gov (United States)

    Narsimhachary, D.; Pal, S.; Shariff, S. M.; Padmanabham, G.; Basu, A.

    2017-09-01

    In the present study, laser-brazed AA6082 to DX56-galvanized steel joints were investigated to understand the influence of process parameters on joint strength in terms of intermetallic layer formation. 1.5-mm-thick sheet of aluminum alloy (AA6082-T6) and galvanized steel (DX56) sheet of 0.7 mm thickness were laser-brazed with 1.5-mm-diameter Al-12% Si solid filler wire. During laser brazing, laser power (4.6 kW) and wire feed rate (3.4 m/min) were kept constant with a varying laser scan speed of 3.5, 3, 2.5, 2, 1.5, and 1 m/min. Microstructure of brazed joint reveals epitaxial growth at the aluminum side and intermetallic layer formation at steel interface. Intermetallic layer formation was confirmed by EDS analysis and XRD study. Hardness profile showed hardness drop in filler region, and failure during tensile testing was initiated through the filler region near the steel interface. As per both experimental study and numerical analysis, it was observed that intermetallic layer thickness decreases with increasing brazing speed. Zn vaporization from galvanized steel interface also affected the joint strength. It was found that high laser scan speed or faster cooling rate can be chosen for suppressing intermetallic layer formation or at least decreasing the layer thickness which results in improved mechanical properties.

  18. Process of Hypertrophic Scar Formation: Expression of Eukaryotic Initiation Factor 6

    Institute of Scientific and Technical Information of China (English)

    Qing-Qing Yang; Si-Si Yang; Jiang-Lin Tan; Gao-Xing Luo; Wei-Feng He; Jun Wu

    2015-01-01

    Background:Hypertrophic scar is one of the most common complications and often causes the disfigurement or deformity in bum or trauma patients.Therapeutic methods on hypertrophic scar treatment have limitations due to the poor understanding of mechanisms of hypertrophic scar formation.To throw light on the molecular mechanism of hypertrophic scar formation will definitely improve the outcome of the treatment.This study aimed to illustrate the negative role ofeukaryotic initiation factor 6 (eIF6) in the process of human hypertrophic scar formation,and provide a possible indicator of hypertrophic scar treatment and a potential target molecule for hypertrophic scar.Methods:In the present study,we investigated the protein expression of eIF6 in the human hypertrophic scar of different periods by immunohistochemistry and Western blot analysis.Results:In the hypertrophic scar tissue,eIF6 expression was significantly decreased and absent in the basal layer of epidermis in the early period,and increased slowly and began to appear in the basal layer of epidermis by the scar formation time.Conclusions:This study confirmed that eIF6 expression was significantly related to the development of hypertrophic scar,and the eIF6 may be a target molecule for hypertrophic scar control or could be an indicator of the outcomes for other treatment modalities.

  19. Modeling secondary organic aerosol formation through cloud processing of organic compounds

    Directory of Open Access Journals (Sweden)

    J. Chen

    2007-10-01

    Full Text Available Interest in the potential formation of secondary organic aerosol (SOA through reactions of organic compounds in condensed aqueous phases is growing. In this study, the potential formation of SOA from irreversible aqueous-phase reactions of organic species in clouds was investigated. A new proposed aqueous-phase chemistry mechanism (AqChem is coupled with the existing gas-phase Caltech Atmospheric Chemistry Mechanism (CACM and the Model to Predict the Multiphase Partitioning of Organics (MPMPO that simulate SOA formation. AqChem treats irreversible organic reactions that lead mainly to the formation of carboxylic acids, which are usually less volatile than the corresponding aldehydic compounds. Zero-dimensional model simulations were performed for tropospheric conditions with clouds present for three consecutive hours per day. Zero-dimensional model simulations show that 48-h average SOA formation is increased by 27% for a rural scenario with strong monoterpene emissions and 7% for an urban scenario with strong emissions of aromatic compounds, respectively, when irreversible organic reactions in clouds are considered. AqChem was also incorporated into the Community Multiscale Air Quality Model (CMAQ version 4.4 with CACM/MPMPO and applied to a previously studied photochemical episode (3–4 August 2004 focusing on the eastern United States. The CMAQ study indicates that the maximum contribution of SOA formation from irreversible reactions of organics in clouds is 0.28 μg m−3 for 24-h average concentrations and 0.60 μg m−3 for one-hour average concentrations at certain locations. On average, domain-wide surface SOA predictions for the episode are increased by 9% when irreversible, in-cloud processing of organics is considered. Because aldehydes of carbon number greater than four are assumed to convert fully to the corresponding carboxylic acids upon reaction with OH in cloud droplets and this assumption may overestimate

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

    Directory of Open Access Journals (Sweden)

    Cristina M Alberini

    2011-03-01

    Full Text Available 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 postreactivation 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.

  1. Enhancement of MgAl2O4 spinel formation from coprecipitated precursor by powder processing

    Indian Academy of Sciences (India)

    Soumen Pal; A K Bandyopadhyay; S Mukherjee; B N Samaddar; P G Pal

    2011-07-01

    Although low temperature fast coprecipitation technique has been used to synthesize stoichiometric (MgO–nAl2O3, = 1) MgAl2O4 spinel forming precursor, delayed spinellization has always been the concern in this process. In this article, the precursor of this ‘fast technique’ has been used for bulk production by further processing by high speed mixing with solvents and mechanical activation by attrition milling in terms of superior spinellization. At 1000°C, MgAl2O4 – -Al2O3 solid solution and MgO phases are formed (spinel formed by 1000°C is regarded as primary spinel). At higher temperatures, due to large agglomerate size, MgO can not properly interact with the exsolved -Al2O3 from spinel solid solution to form secondary spinel; and consequently spinellization gets affected. Solvent treatment and attrition milling of the coprecipitated precursor disintegrate the larger agglomerates into smaller size (effect is more in attrition). Then MgO comes in proper contact with exsolved alumina, and therefore total spinel formation (primary + secondary) is enhanced. Extent of spinellization, for processed calcined samples where some alumina exists as solid solution with spinel, can be determined from the percentage conversion of MgO. Analysis of the processed powders suggests that the 4 h attrited precursor is most effective in terms of nano size (< 25 nm) stoichiometric spinel crystallite formation at ≤ 1100°C.

  2. Microstructures and formation mechanism of hypoeutectic white cast iron by isothermal electromagnetic rheocast process

    Directory of Open Access Journals (Sweden)

    Zhang Wanning

    2010-05-01

    Full Text Available An investigation was made on the evolution of microstructures of hypoeutectic white cast iron slurry containing 2.5wt.%C and 1.8wt.%Si produced by rheocasting in which the solidifying alloy was vigorously agitated by electromagnetic stirrer during isothermal cooling processes. The results indicated that under the proper agitating temperatures and speeds applied, the dendrite structures in white cast iron slurry were gradually evolved into spherical structures during a certain agitating time. It also revealed that the bent dendrites were formed by either convection force or by the growth of the dendrites themselves in the bending direction; then, as they were in solidifying, they were gradually being alternated into separated particles and into more spherical structures at the end of the isothermal cooling process. Especially, the dendrites were granulated as the bending process proceeding, which suggested that they were caused by unwanted elements such as sulfur and phosphor usually contained in engineering cast iron. Convective flow of the melt caused corrosion on the dendritic segments where they were weaker in strength and lower in melting temperature because of higher concentration of sulfur or phosphor. And the granulation process for such dendrites formed in the melt became possible under the condition. Certainly, dendrite fragments are another factors considerable to function for spherical particles formation. A new mechanism, regarding to the rheocast structure formation of white cast iron, was suggested based on the structural evolution observed in the study.

  3. Holliday junction resolvases.

    Science.gov (United States)

    Wyatt, Haley D M; West, Stephen C

    2014-09-02

    Four-way DNA intermediates, called Holliday junctions (HJs), can form during meiotic and mitotic recombination, and their removal is crucial for chromosome segregation. A group of ubiquitous and highly specialized structure-selective endonucleases catalyze the cleavage of HJs into two disconnected DNA duplexes in a reaction called HJ resolution. These enzymes, called HJ resolvases, have been identified in bacteria and their bacteriophages, archaea, and eukaryotes. In this review, we discuss fundamental aspects of the HJ structure and their interaction with junction-resolving enzymes. This is followed by a brief discussion of the eubacterial RuvABC enzymes, which provide the paradigm for HJ resolvases in other organisms. Finally, we review the biochemical and structural properties of some well-characterized resolvases from archaea, bacteriophage, and eukaryotes. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

  4. Wireless Josephson Junction Arrays

    Science.gov (United States)

    Adams, Laura

    2015-03-01

    We report low temperature, microwave transmission measurements on a wireless two- dimensional network of Josephson junction arrays composed of superconductor-insulator -superconductor tunnel junctions. Unlike their biased counterparts, by removing all electrical contacts to the arrays and superfluous microwave components and interconnects in the transmission line, we observe new collective behavior in the transmission spectra. In particular we will show emergent behavior that systematically responds to changes in microwave power at fixed temperature. Likewise we will show the dynamic and collective response of the arrays while tuning the temperature at fixed microwave power. We discuss these spectra in terms of the Berezinskii-Kosterlitz-Thouless phase transition and Shapiro steps. We gratefully acknowledge the support Prof. Steven Anlage at the University of Maryland and Prof. Allen Goldman at the University of Minnesota. Physics and School of Engineering and Applied Sciences.

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

    Science.gov (United States)

    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.

  6. Calcium phosphate coating on magnesium alloy by biomimetic method :Investigation of morphology ,composition and formation process

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Magnesium alloy has similar mechanical properties with natural bone and can degrade via corrosion in the electrolytic environment of the human body.Calcium phosphate has been proven to possess bioactivity and bone inductivity.In order to integrate both advantages,calcium phosphate coating was fabricated on magnesium alloy by a biomimetic method.Supersaturated calcification solutions (SCSs) with different Ca/P ratio and C1- concentration were used as mimetic solutions.The morphology,composition and formation process of the coating were studied with scanning electron microscopy (SEM),energy dispersive spectrometer (EDS),Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD).The results show that a uniform calcium phosphate coating was observed on magnesium alloy,the properties of which could be adjusted by the SCSs with different Ca/P ratio.The formation process of the coating was explored by immersing magnesium alloy in SCSs with different Cl- concentration which could adjust the hydrogen production.According to SEM results,the hydrogen bubbles were associated with the formation of grass-like and flower-like coating morphologies.In conclusion,the biomimetic method was effective to form calcium phosphate coating on magnesium alloy and the morphology and composition of the coating could be accommodated by the Ca/P ratio and Cl- concentration in SCSs.

  7. Investigation of Formation Process of the Chrome-free Passivation Film of Electrodeposited Zinc

    Institute of Scientific and Technical Information of China (English)

    ZHU Li-qun; YANG Fei; HUANG Hui-jie

    2007-01-01

    The feasibility was investigated to substitute chrome-free passivation treatment of electrodeposited zinc in a titanium bath for chromate passivation treatment. The formation mechanism of the chrome-free passivation film was further analyzed. The surface morphologies and the elemental compositions of the treated samples with varied immersion times were observed by scanning electron microscopy (SEM) and determined by energy dispersion spectrometry (EDS), respectively. The electrode potential of the sample surface was recorded in the film formation process. The changes of the electrode potential are in accordance with that of SEM and EDS of the sample surface. The results of X-ray photoelectron spectroscopy (XPS) show the chrome-free passivation film composed of ZnO, SiO2,TiO2, Zn4Si2O7(OH)2, and SrF2. The anode zinc dissolution and the local pH value increase due to the cathode hydrogen ion reduction process result in the formation of the chrome-free passivation film. The macro-images of the chrome-free passivation films formed on electrodeposited zinc show that the color of the film changes from blue to iridescence with the increase of the immersion times.

  8. Limits Imposed on Heat Produced during Core Formation by Radiative Transfer Processes and Thermodynamic Laws

    Science.gov (United States)

    Criss, R. E.; Hofmeister, A.

    2010-12-01

    The popular view that Earth is sufficiently hot to still be shedding primordal heat, largely originating in the core, is inconsistent with thermodynamic constraints and recent heat transport studies. Previous work presumes that the large difference in gravitational potential energy (Ug) between a fictious, homogeneous reference state and Earth’s current layered configuration of metallic core and rocky mantle was converted to frictional heat during core formation, greatly increasing temperature (T) inside the Earth. However, heating (ΔT >0) was deduced by assuming that Ug is positive, which is inconsistent with Newton’s law of gravitation. Use of an erroneous sign for ΔUg has prevented recognition that the process is an exothermic transformation. Thermodynamic principles were not considered in previous analyses: neglecting the effect of the change in configuration on entropy and energy contributes greatly to the view that heat is retained. Instead, stringent limits are set on the permissible temperature increase by the rapid rate of ballistic radiative transfer, a process associated with transient events, as well as by the 1st and 2nd laws of thermodynamics. In the static, instantaneous model of core formation, configurational entropy (S) of the Earth decreases upon forming the ordered layered state; this entropy decrease is offset by a greater increase in S of the surrounding universe, which can only be accomplished by release of heat to space (the surroundings). Instantaneous dissipation of heat in the static model reasonably approximates radiative processes being superfast. Core formation involves negligible changes in volume and rotational energy, so Helmholtz free energy (=Ug-TS) is conserved, as in atmospheric processes and other graviational-thermodynamic problems. Because S of the universe is immense and heat must flow from hotter to colder bodies, negligible heat from core formation is retained, consistent with the exothermic nature of this transition

  9. Reorganization of microtubular cytoskeleton and formation of cellular processes during post-telophase in haemanthus endosperm.

    Science.gov (United States)

    Bajer, A S; Smirnova, E A

    1999-10-01

    We followed time-dependent post-telophase reorganization of the microtubule cytoskeleton on immunostained preparations of endosperm of the higher plant Haemanthus. After completion of mitosis, the phragmoplast continued to reorganize for several hours. This prompted the formation of phragmoplast-like derivatives (secondary and accessory phragmoplasts and peripheral microtubular ring). Next, elongated cellular protrusions (processes) appeared at the cell periphery. These processes contained long microtubule bundles and disorderly arranged actin filaments. Microtubule converging centers or accessory phragmoplasts were often present at the tips of the processes. Observation in vivo demonstrated that processes were formed at the cell periphery as extensions of lammelipodia or filopodia-type protrusions that commonly terminated with cytoplasmic blobs. We suggest that processes are derivatives of a peripheral microtubular ring that reorganizes gradually into cellular protrusions. Endosperm processes have several features of neuronal cells, or animal somatic cells with overexpressed MAPs. Since microtubule-containing processes were never detected shortly after extrusion of the cells from the embryo sac, this course of events might be restricted specifically to extruded endosperm and triggered either by removal of cells, their placement in monolayer on agar substrate, or both. Thus, post telophase behavior of endosperm cells offers a novel experimental system for studies of cytoskeleton in higher plants.

  10. Formation of Structure and Properties in Casting Processes on the Example of AZ91 Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    Augustyn B.

    2014-06-01

    Full Text Available Contemporary materials engineering requires the use of materials characterised by high mechanical properties, as these precisely properties determine the choice of material for parts of machinery and equipment. Owing to these properties it is possible to reduce the weight and, consequently, the consumption of both material and energy. Trying to meet these expectations, the designers are increasingly looking for solutions in the application of magnesium alloys as materials offering a very beneficial strength-to-weight ratio. However, besides alloying elements, the properties are to a great extent shaped by the solidification conditions and related structure. The process of structure formation depends on the choice of casting method forced by the specific properties of casting or by the specific intended use of final product. The article presents a comparison of AZ91 magnesium alloys processed by different casting technologies. A short characteristic was offered for materials processed by the traditional semi-continuous casting process, which uses the solidification rates comprised in a range of 5 - 20°C/s, and for materials made in the process of Rapid Solidification, where the solidification rate can reach 106 °C/s. As a result of the casting process, a feedstock in the form of billets and thin strips was obtained and was subjected next to the process of plastic forming. The article presents the results of structural analysis of the final product. The mechanical properties of the ø7 mm extruded rods were also evaluated and compared.

  11. Formation and fate of marine snow : small-scale processes with large-scale implications

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2001-01-01

    to the aggregate. Also, suspended bacteria may enjoy the elevated concentration of organic solutes in the plume. I explore these small-scale formation and degradation processes by means of models, experiments and field observations. The larger scale implications for the structure and functioning of pelagic food......Marine snow aggregates are believed to be the main vehicles for vertical material transport in the ocean. However, aggregates are also sites of elevated heterotrophic activity, which may rather cause enhanced retention of aggregated material in the upper ocean. Small-scale biological......-physical interactions govern the formation and fate of marine snow. Aggregates may form by physical coagulation: fluid motion causes collisions between small primary particles (e.g. phytoplankton) that may then stick together to form aggregates with enhanced sinking velocities. Bacteria may subsequently solubilise...

  12. [The effect of impression formation on memory of trait words: relation between coding and retrieval process].

    Science.gov (United States)

    Takaoka, M

    2000-08-01

    Three experiments investigated the effect of impression formation of a person on the recall and recognition of trait words. The subjects were assigned to one of four groups: Impression, Memory, Impression-Memory, and Incidental groups. Each subject performed an orienting task followed by free recall and recognition tests. In a recall test, false recall of antonyms of targets occurred more often in the Memory group than in the Impression group. There was no difference in the correct recall. In a multiple choice recognition test and a yes-no recognition test, false recognition to antonyms of targets occurred more often in the Memory group than in the Impression group. Hit to targets occurred more often in the Impression group than in the Memory group. These results were interpreted as showing that formation of an impression for a person had different effects for recall and recognition tests. The results were discussed in terms of a relation between encoding and retrieval processes.

  13. Factor analysis of processes of corporate culture formation at industrial enterprises of Ukraine

    Directory of Open Access Journals (Sweden)

    Illiashenko Sergii

    2016-06-01

    Full Text Available Authors have analyzed and synthesized the features of formation and development of the corporate culture at industrial enterprises of Ukraine and on this basis developed recommendations for application in the management of strategic development. During the research authors used the following general scientific methods: at research of patterns of interaction national culture, corporate culture and the culture of the individual authors used logical generalization method; for determining factors influencing corporate culture formation with the level of occurrence authors used factor analysis; for trend analysis of the corporate culture development at appropriate levels authors used comparative method. Results of the analysis showed that macro- and microfactors are external and mezofaktors (adaptability of business and corporate governance, corporate ethics, corporate social responsibility and personnel policies, corporate finance are internal for an enterprise. Authors have identified areas for each of the factors, itemized obstacles to the establishment and development of corporate culture at Ukrainian industrial enterprises and proposed recommendations for these processes management.

  14. The Chemical Evolution of Narrow Emission Line Galaxies: the Key to their Formation Processes The Chemical Evolution of Narrow Emission Line Galaxies: the Key to their Formation Processes

    Directory of Open Access Journals (Sweden)

    R. A. Ortega-Minakata

    2012-02-01

    Full Text Available Utilizando la mayor muestra de galaxias con líneas de emisión angostas disponible hasta el momento, se muestra que sus características espectrales están correlacionadas con diferentes parámetros físicos, como las abundancias químicas, las morfologías, las masas del bulbo, y la edad estelar promedio de las poblaciones estelares de la galaxia anfitriona. Por lo tanto, se sugiere que las variaciones espectrales observadas en diagramas de diagnóstico estándares no se deben únicamente a las variaciones de los parámetros o las estructuras de ionización, sino que reflejan también la evolución química de las galaxias, relacionada con diferentes procesos de formación.  Using the largest sample of narrow emission line galaxies available so far, we show that their spectral characteristics are correlated with different physical parameters, like the chemical abundances, the morphologies, the masses of the bulge and the mean stellar age of the stellar populations of the host galaxies. It suggests that the spectral variations observed in standard spectroscopic diagnostic diagrams are not due solely to variations of ionization parameters or structures but reflect also the chemical evolution of the galaxies, which in turn can be explained by different galaxy formation processes.

  15. The role of local heating in the formation process of UV written optical waveguides

    DEFF Research Database (Denmark)

    Svalgaard, Mikael; Harpøth, Anders; Andersen, Marc

    2005-01-01

    A behavior is reported where the index change process used for UV writing of integrated optical waveguides in deuterium loaded Ge:SiO2 glass can become unstable and suddenly switch off or on. It is shown that such discontinuities are associated with abrupt changes in the amount of absorbed UV power....... We suggest that these events are controlled by a coupling between UV absorption, local heating and the D2-GeO2 reaction rate. From our findings we predict, and confirm experimentally, that strong waveguides can not be fabricated under normal UV writing conditions in thin core layers with a low...... initial UV absorption. Our findings show that an improved understanding of the waveguide formation process and future process development requires that thermal effects are taken into account....

  16. Effect of Processing Pressure on Isolated Pore Formation during Controlled Directional Solidification in Small Channels

    Science.gov (United States)

    Cox, Matthew C.; Anilkumar, Amrutur V.; Grugel, RIchard N.; Lee, Chun P.

    2008-01-01

    Directional solidification experiments were performed, using succinonitrile saturated with nitrogen gas, to examine the effects of in-situ processing pressure changes on the formation growth, and evolution of an isolated, cylindrical gaseous pore. A novel solidification facility, capable of processing thin cylindrical samples (I.D. < 1.0 mm), under controlled pressure conditions, was used for the experiments. A new experimental method for growing the isolated pore from a seed bubble is introduced. The experimental results indicate that an in-situ processing pressure change will result in either a transient change in pore diameter or a complete termination of pore growth, indicating that pressure changes can be used as a control parameter to terminate bubble growth. A simple analytical model has been introduced to explain the experimental observations.

  17. Combustion and structure formation in SHS processes under microgravity conditions: SHS plans for microgravity experiments

    Science.gov (United States)

    Merzhanov, A. G.

    1995-01-01

    This paper outlines ISMAN suggestions for the joint NASA-RSA project 'Combustion and Structure formation in SHS Processes under Microgravity Conditions'. The basic ideas of this work naturally follow from our almost 30-year experience in the field of SHS. As a matter of fact, we have already obtained some results in the following two directions closely related to the microgravity problem. One is the studies on SHS processes in the field of centrifugal forces. These studies aimed at the intensification of gravity-sensitive SHS processes in multicomponent highly caloric systems forming melts at high overloads (up to 2000 g). In other words, these studies had the objectives that are inverse to those in the microgravity studies. The second group of results directly relates to the microgravity problem and the project under consideration. These experiments played the important role in establishing links between SHS and microgravity.

  18. Drebrin controls neuronal migration through the formation and alignment of the leading process.

    Science.gov (United States)

    Dun, Xin-peng; Bandeira de Lima, Tiago; Allen, James; Geraldo, Sara; Gordon-Weeks, Phillip; Chilton, John K

    2012-03-01

    Formation of a functional nervous system requires neurons to migrate to the correct place within the developing brain. Tangentially migrating neurons are guided by a leading process which extends towards the target and is followed by the cell body. How environmental cues are coupled to specific cytoskeletal changes to produce and guide leading process growth is unknown. One such cytoskeletal modulator is drebrin, an actin-binding protein known to induce protrusions in many cell types and be important for regulating neuronal morphology. Using the migration of oculomotor neurons as a model, we have shown that drebrin is necessary for the generation and guidance of the leading process. In the absence of drebrin, leading processes are not formed and cells fail to migrate although axon growth and pathfinding appear grossly unaffected. Conversely, when levels of drebrin are elevated the leading processes turn away from their target and as a result the motor neuron cell bodies move along abnormal paths within the brain. The aberrant trajectories were highly reproducible suggesting that drebrin is required to interpret specific guidance cues. The axons and growth cones of these neurons display morphological changes, particularly increased branching and filopodial number but despite this they extend along normal developmental pathways. Collectively these results show that drebrin is initially necessary for the formation of a leading process and subsequently for this to respond to navigational signals and grow in the correct direction. Furthermore, we have shown that the actions of drebrin can be segregated within individual motor neurons to direct their migration independently of axon guidance. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Enhanced photosensitization process induced by the p–n junction of Bi{sub 2}O{sub 2}CO{sub 3}/BiOCl heterojunctions on the degradation of rhodamine B

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Haijing [Key Laboratory of Photonic and Electric Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China); Xu, Lingling, E-mail: xulingling_hit@163.com [Key Laboratory of Photonic and Electric Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China); Wei, Bo [Department of Physics, Harbin Institute of Technology, Harbin 150080 (China); Zhang, Mingyi; Gao, Hong; Sun, Wenjun [Key Laboratory of Photonic and Electric Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025 (China)

    2014-06-01

    Herein, we report the enhanced photosensitization process in the nanosheet Bi{sub 2}O{sub 2}CO{sub 3}/BiOCl heterojunctions photocatalyst. The combined XRD, FT-IR and Raman results have confirmed the co-existence of Bi{sub 2}O{sub 2}CO{sub 3} and BiOCl phases in the composites. Although both Bi{sub 2}O{sub 2}CO{sub 3} and BiOCl are wide bandgap semiconductors, the composites showed an unexpectedly high catalytic activity in decomposing RhB (rhodamine B) aqueous solution under visible light irradiation. The mechanism of enhanced photocatalytic activity was ascribed to the inner electric field formed in the Bi{sub 2}O{sub 2}CO{sub 3}/BiOCl p–n junction.

  20. Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans.

    Science.gov (United States)

    Friedman, Mendel

    2015-06-01

    Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

  1. Understanding the process of social network evolution: Online-offline integrated analysis of social tie formation

    Science.gov (United States)

    Kwak, Doyeon

    2017-01-01

    It is important to consider the interweaving nature of online and offline social networks when we examine social network evolution. However, it is difficult to find any research that examines the process of social tie formation from an integrated perspective. In our study, we quantitatively measure offline interactions and examine the corresponding evolution of online social network in order to understand the significance of interrelationship between online and offline social factors in generating social ties. We analyze the radio signal strength indicator sensor data from a series of social events to understand offline interactions among the participants and measure the structural attributes of their existing online Facebook social networks. By monitoring the changes in their online social networks before and after offline interactions in a series of social events, we verify that the ability to develop an offline interaction into an online friendship is tied to the number of social connections that participants previously had, while the presence of shared mutual friends between a pair of participants disrupts potential new connections within the pre-designed offline social events. Thus, while our integrative approach enables us to confirm the theory of preferential attachment in the process of network formation, the common neighbor theory is not supported. Our dual-dimensional network analysis allows us to observe the actual process of social network evolution rather than to make predictions based on the assumption of self-organizing networks. PMID:28542367

  2. DEMONSTRATION OF THE STRATEGY FORMATION PROCESS: A CASE STUDY IN A INNOVATIVE ORGANIZATION

    Directory of Open Access Journals (Sweden)

    Daniel Teodoro Gomes

    2012-05-01

    Full Text Available This paper presents a study of strategy formation process with the following starting question: "How the strategy is shaped in an innovative company and how the factors manifesting in the process?". The research builds on a case study of a company considered innovative leader in its industry and a pioneer in providing various services in the area of mobile phone in Brazil. Data collection was through interviews semi-structured with directors and managers involved in strategy formation, supplemented by documents and direct observation. Data analysis is based on the techniques of discourse analysis, from the persuasion strategies suggested by Linhares and Faria (1993. The company's strategy studied can be defined as an entrepreneurial vision, focused on growth supported by a process of diversification of product lines from a new direction composed of three elements: (i componentization; (ii segmentation by products chain and; (iii external to finance leverage in order to resumption of innovative projects. It was concluded that the company's strategy focused on these three factors, supported by a deliberate vision of the future, conditions its historical trajectory type standard cultural, its core values, which acts as a motivator and guide for members of the organization decisions and actions.

  3. On the horizontal distribution of algal-bloom in Chaohu Lake and its formation process

    Science.gov (United States)

    Chen, Yuan-Ying; Liu, Qing-Quan

    2014-10-01

    Based on the remote sensing images of algae, the present work analyzes the horizontal distribution characteristics of algal blooms in Chaohu Lake, China, which also reveals the frequency of algal blooms under different wind directions. Further, an unstructured-grid, three-dimensional finite-volume coastal ocean model (FVCOM) is applied to investigate the wind-induced currents and the transport process to explain the reason why algal blooms occur at the detected places. We first deduce the primary distribution of biomass from overlaid satellite images, and explain the formation mechanism by analyzing the pollution sources, and simulating the flow field and transportation process under prevailing wind over Chaohu Lake. And then, we consider the adjustment action of the wind on the corresponding day and develop a two-time scale approach to describe the whole formation process of algae horizontal distribution in Chaohu Lake. That is, on the longer time scale, i.e., during bloom season, prevailing wind determines the primary distribution of biomass by inducing the characteristic flow field; on the shorter time scale, i.e., on the day when bloom occurs, the wind force adjusts the primary distribution of biomass to form the final distribution of algal bloom.

  4. Formation of asymmetrical structured silica controlled by a phase separation process and implication for biosilicification.

    Directory of Open Access Journals (Sweden)

    Jia-Yuan Shi

    Full Text Available Biogenetic silica displays intricate patterns assembling from nano- to microsize level and interesting non-spherical structures differentiating in specific directions. Several model systems have been proposed to explain the formation of biosilica nanostructures. Of them, phase separation based on the physicochemical properties of organic amines was considered to be responsible for the pattern formation of biosilica. In this paper, using tetraethyl orthosilicate (TEOS, Si(OCH2CH34 as silica precursor, phospholipid (PL and dodecylamine (DA were introduced to initiate phase separation of organic components and influence silica precipitation. Morphology, structure and composition of the mineralized products were characterized using a range of techniques including field emission scanning electron microscopy (FESEM, transmission electron microscope (TEM, X-ray diffraction (XRD, thermogravimetric and differential thermal analysis (TG-DTA, infrared spectra (IR, and nitrogen physisorption. The results demonstrate that the phase separation process of the organic components leads to the formation of asymmetrically non-spherical silica structures, and the aspect ratios of the asymmetrical structures can be well controlled by varying the concentration of PL and DA. On the basis of the time-dependent experiments, a tentative mechanism is also proposed to illustrate the asymmetrical morphogenesis. Therefore, our results imply that in addition to explaining the hierarchical porous nanopatterning of biosilica, the phase separation process may also be responsible for the growth differentiation of siliceous structures in specific directions. Because organic amine (e.g., long-chair polyamines, phospholipids (e.g., silicalemma and the phase separation process are associated with the biosilicification of diatoms, our results may provide a new insight into the mechanism of biosilicification.

  5. Metagenomic Analysis of Some Potential Nitrogen-Fixing Bacteria in Arable Soils at Different Formation Processes.

    Science.gov (United States)

    Wolińska, Agnieszka; Kuźniar, Agnieszka; Zielenkiewicz, Urszula; Banach, Artur; Izak, Dariusz; Stępniewska, Zofia; Błaszczyk, Mieczysław

    2017-01-01

    The main goal of the study was to determine the diversity of the potential nitrogen-fixing (PNF) bacteria inhabiting agricultural (A) soils versus wastelands serving as controls (C). The soils were classified into three groups based on the formation process: autogenic soils (Albic Luvisols, Brunic Arenosols, Haplic Phaeozem) formed on loess material, hydrogenic soils (Mollic Gleysols, Eutric Fluvisol, Eutric Histosol) formed under the effect of stagnant water and lithogenic soils (Rendzina Leptosols) formed on limestone. In order to determine the preferable conditions for PNF bacteria, the relationships between the soil chemical features and bacterial operational taxonomic units (OTUs) were tested. Additionally, the nitrogen content and fertilisation requirement of the lithogenic (LG), autogenic (AG) and hydrogenic (HG) soils were discussed. The composition of the bacterial communities was analysed with the next-generation sequencing (NGS) by the Ion Torrent™ technology. The sequences were clustered into OTU based on a 99 % similarity threshold. The arable soils tested were distinctly dominated by β-Proteobacteria representatives of PNF bacteria belonging to the genus Burkholderia. Bacteria from the α-Proteobacteria class and Devosia genus were subdominants. A free-living Cyanobacteria population dominated in A rather than in C soils. We have found that both soil agricultural management and soil formation processes are the most conducive factors for PNF bacteria, as a majority of these microorganisms inhabit the AG group of soils, whilst the LG soils with the lowest abundance of PNF bacteria revealed the need for additional mineral fertilisation. Our studies have also indicated that there are close relationships between soil classification with respect to soil formation processes and PNF bacteria preference for occupation of soil niches.

  6. Advanced transmission electron microscopy studies in low-energy ion implanted Si Semiconductors; Junctions; Silicon

    CERN Document Server

    Wang, T S

    2002-01-01

    As the dimensions of semiconductor devices shrink down to 0.1 mu m and beyond, low energy ion implantation is required to introduce shallower junctions to match such small devices. In this work, transmission electron microscopy (TEM) is employed to analyse low energy implanted junctions with both structural and chemical analyses. High resolution transmission electron microscopy (HRTEM) has been employed to observe Si crystal damage and amorphization due to low energy B sup + /As sup + ion implantations, and also, defect formation/annihilation during rapid thermal annealing (RTA). The damage effects due to different implant temperatures between 300 deg C and -150 deg C are also discussed. Since knowledge of the distribution of low energy ion implanted dopants in Si is extremely important for semiconductor device processing, energy filtered transmission electron microscopy (EFTEM) has been employed to determine implanted B distributions in Si while Z-contrast imaging and X-ray analytical mapping techniques are ...

  7. Enhanced photocatalytic performance of porous TiO2 nanobelts with phase junctions

    Science.gov (United States)

    Pang, Lai-xue; Wang, Xiao-ying; Tang, Xin-de

    2015-01-01

    Porous TiO2 nanobelts with rutile/anatase phase junctions are successfully prepared through a hydrothermal route and ion exchange process. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were conducted to characterize the products. The photocatalytic performance of the porous nanobelts was evaluated by measuring the degradation of methyl blue under UV light irradiation. The photocatalytic activity of the porous nanobelts is much superior to that of P-25 and pristine non-porous nanobelts. The excellent photocatalytic of porous nanobelts can be attributed to pores which enhanced ability in UV-light harvesting. What's more, the existence of rutile/anatase phase junction is favorable for the formation and separation of the hole-electron pair, resulting in a reduced electron-hole recombination.

  8. The Chemical Evolution of Narrow Emission Line Galaxies: the Key to their Formation Processes

    CERN Document Server

    Torres-Papaqui, J P; Ortega-Minakata, R A

    2011-01-01

    Using the largest sample of narrow emission line galaxies available so far, we show that their spectral characteristics are correlated with different physical parameters, like the chemical abundances, the morphologies, the masses of the bulge and the mean stellar age of the stellar populations of the host galaxies. It suggests that the spectral variations observed in standard spectroscopic diagnostic diagrams are not due solely to variations of ionization parameters or structures but reflect also the chemical evolution of the galaxies, which in turn can be explained by different galaxy formation processes.

  9. Quantum-chemical approach to defect formation processes in non-metallic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kotomin, E.A.; Shluger, A.L. (Latvijskij Gosudarstvennyj Univ., Riga (USSR))

    1989-01-01

    Results of the quantum-chemical simulation of the formation of structural and radiation defects are reviewed, using ice, silicon, and silicon dioxide as examples. The relationship between the structural elements of these crystals and the structural defects is analysed. Models of the main defects, their optical characteristics, and the activation energy of their migration are discussed. The relationship between the characteristics obtained by quantum-chemical calculations and the parameters of the macroscopic kinetics of the processes induced by defects in dielectric crystals is considered. (author).

  10. Investigating Processes of Materials Formation via Liquid Phase and Cryogenic TEM

    Energy Technology Data Exchange (ETDEWEB)

    De Yoreo, James J.; Sommerdijk, Nico

    2016-06-14

    The formation of materials in solutions is a widespread phenomenon in synthetic, biological and geochemical systems, occurring through dynamic processes of nucleation, self-assembly, crystal growth, and coarsening. The recent advent of liquid phase TEM and advances in cryogenic TEM are transforming our understanding of these phenomena by providing new insights into the underlying physical and chemical mechanisms. The techniques have been applied to metallic and semiconductor nanoparticles, geochemical and biological minerals, electrochemical systems, macromolecular complexes, and selfassembling systems, both organic and inorganic. New instrumentation and methodologies currently on the horizon promise new opportunities for advancing the science of materials synthesis.

  11. Relation between soil matrix potential changes and water conversion ratios during methane hydrate formation processes in loess

    Institute of Scientific and Technical Information of China (English)

    Peng Zhang; Qingbai Wu; Guanli Jiang; Yibin Pu

    2011-01-01

    With a new apparatus designed and assembled by ourselves,the matrix potential of non-saturated loess was firstly measured and studied during methane hydrate formation processes.The experimental results showed that during two formation processes,the matrix potential changes of the loess all presented a good linear relationship with water conversion ratios.In addition,although it was well known that the secondary gas hydrate formation was easier than the initial,our experimental results showed that the initial hydrate formation efficiency in non-saturated loess was higher than that of the secondary.

  12. Low-Cost Multi-Junction Photovoltaic Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed SBIR project will provide a pathway to dramatically reduce the cost of multi-junction solar cells. The project leverages a TRL6 micropackaging process...

  13. Ozone formation in relation with combustion processes in highly populated urban areas

    Directory of Open Access Journals (Sweden)

    Pasquale Avino

    2015-07-01

    Full Text Available The complex chain of photochemical reactions is one of the most important tasks in the air quality evaluation, expecially in urban areas. In fact, in this case there are high emission levels of NOx and no-methane hydrocarbons by combustion processes such as autovehicular traffic, domestic heating and industrial plants. Ozone is not emitted directly into the atmosphere but it is formed from a complex series of reactions between emitted nitrogen oxides (NOx and reactive organic compounds (ROC. The high ozone concentrations, which occur during photochemical episodes, are usually accompanied by elevated concentrations of other photochemical oxidants such as nitric acid (HNO3, peroxyacylnitrates (PANs, hydrogen peroxide (H2O2, etc. The complex series of these reactions constitutes the most important issue to the degradation of air quality. Further, the NMHCs play a key role in the formation of photochemical air pollution: they are considered as precursors for ozone production at the ground level when the sunlight and nitrogen oxides are present. From a practically point of view defining a quality standard or a limit is substantially correct but it is no sufficient to solve the problem. So it should become necessary to acquire knowledge on the different formation mechanisms of the photochemical pollution phenomena. In this paper there will be shown the results of a long-term study performed in Rome for evaluating the ozone formation in relationship with the autovehicular traffic density.

  14. Evaluation of the relationship between bulk organic precursors and disinfection byproduct formation for advanced oxidation processes.

    Science.gov (United States)

    Mayer, Brooke K; Daugherty, Erin; Abbaszadegan, Morteza

    2015-02-01

    Advanced oxidation processes (AOPs) are gaining traction as they offer mineralization potential rather than transferring contaminants between media. However, AOPs operated with limited energy and/or chemical inputs can exacerbate disinfection byproduct (DBP) formation, even as precursors such as dissolved organic carbon, UV254, and specific UV absorbance (SUVA) decrease. This study examined the relationship between DBP precursors and formation using TiO2 photocatalysis experiments, external AOP and non-AOP data, and predictive DBP models. The top-performing indicator, SUVA, generally correlated positively with trihalomethanes and haloacetic acids, but limited-energy photocatalysis yielded contrasting negative correlations. The accuracy of predicted DBP values from models based on bulk parameters was generally poor, regardless of use and extent of AOP treatment and type of source water. Though performance improved for scenarios bounded by conditions used in model development, only 0.5% of the model/dataset pairings satisfied all measured parameter boundary conditions, thereby introducing skepticism toward model usefulness. Study findings suggest that caution should be employed when using bulk indicators and/or models as a metric for AOP mitigation of DBP formation potential, particularly for limited-energy/chemical inputs.

  15. Study of process parameters on aluminium foam formation in the Al-6Si-3Mg alloy

    Directory of Open Access Journals (Sweden)

    J. Juarez-Hernandez

    2014-04-01

    Full Text Available The aim of this research was to study the process parameters that promote foam formation by injecting N2 into Al-6Si-3Mg wt % molten alloy with silicon carbide particles additions (SiC. An experimental design was proposed, in which the contents of SiC particles were 0, 10, 30 and 50 wt %, and the overheating was defined as ΔT= TF - TL , where TL is the liquidus temperature and was determined by the cooling curve method and the foaming temperatures were selected as TF at 630, 610, 580 and 570 °C. Flow and pressure of air blow were constant, 2,0 lt/min and 4,0 atm, respectively. The foam formation was possible only under two experimental conditions, 10 wt % SiC at ΔT > 12 °C and 30 wt % SiC at ΔT > 10 °C. The foams obtained under these conditions were stable, while with other conditions of experiments, bubble coallesence occurred. Finally, it was concluded that the foam formation occurred by SiC contents lower than 30 wt % SiC and temperatures slightly above the liquidus.

  16. Proteomic analysis of renal calculi indicates an important role for inflammatory processes in calcium stone formation.

    Science.gov (United States)

    Merchant, Michael L; Cummins, Timothy D; Wilkey, Daniel W; Salyer, Sarah A; Powell, David W; Klein, Jon B; Lederer, Eleanor D

    2008-10-01

    Even though renal stones/calculi occur in approximately 10% of individuals, they are an enormous economic burden to the entire US health system. While the relative metabolic composition of renal calculi is generally known, there is no clear understanding of the genetics of renal stone formation, nor are there clear prognostic indicators of renal stone formation. The application of proteomics to the analysis of renal calculi axiomatically holds that insight into renal stone pathobiology can be gained by a more comprehensive understanding of renal calculus protein composition. We analyzed isolated renal stone matrix proteins with mass spectrometric and immunohistochemical methods identifying 158 proteins with high confidence, including 28 common proteins. The abundant proteins included those identified previously in stones and proteins identified here for the first time, such as myeloid lineage-specific, integral membrane and lipid regulatory proteins. Pathway analyses of all proteins identified suggested that a significant fraction of the most abundant matrix proteins participate in inflammatory processes. These proteomic results support the hypothesis that stone formation induces a cellular inflammatory response and the protein components of this response contribute to the abundant stone matrix proteome.

  17. Role of VLDL Receptor in the Process of Foam Cell Formation

    Institute of Scientific and Technical Information of China (English)

    屈伸; 吴凡; 田俊; 李映红; 王燕; 王宇哲; 宗义强

    2004-01-01

    Summary: The role of very low density lipoprotein receptor (LVLDR) in the process of foam cell formation was investigated. After the primary cultured mouse peritoneal macrophages were incubated with VLDL, β-VLDL or low density lipoprotein (LDL), respectively for 24 h and 48 h, foam cells formation was identified by oil red O staining and cellular contents of triglyceride (TG) and total cholesterol (TC) were determined. The mRNA levels of LDLR, LDLR related protein (LRP)and VLDLR were detected by semi-quantitative RT-PCR. The results demonstrated that VLDL, βVLDL and LDL could increase the contents of TG and TC in macrophages. Cells treated with VLDL or β-VLDL showed markedly increased expression of VLDLR and decreased expression of LDLR, whereas LRP was up-regulated slightly. For identifying the effect of VLDL receptor on cellular lipid accumulation, Idl-A7-VR cells, which expresses VLDLR and trace amount of LRP without functional LDLR, was used to incubate with lipoproteins for further examination. The results elucidated that the uptake of triglyceride-rich lipoprotein mediated by VLDLR plays an important role in accumulation of lipid and the formation of foam cells.

  18. The Link between Rare-Earth Peak Formation and the Astrophysical Site of the R Process

    Science.gov (United States)

    Mumpower, Matthew R.; McLaughlin, Gail C.; Surman, Rebecca; Steiner, Andrew W.

    2016-12-01

    The primary astrophysical source of the rare-earth elements is the rapid neutron capture process (r process). The rare-earth peak that is seen in the solar r-process residuals has been proposed to originate as a pile-up of nuclei during the end of the r process. We introduce a new method utilizing Monte Carlo studies of nuclear masses in the rare-earth region, that includes self-consistently adjusting β-decay rates and neutron capture rates, to find the mass surfaces necessary for the formation of the rare-earth peak. We demonstrate our method with two types of astrophysical scenario, one corresponding to conditions typical of hot winds from core-collapse supernovae and stellar-mass accretion disks, and one corresponding to conditions typical of the ejection of the material from the tidal tails of neutron star mergers. In each type of astrophysical condition, this method successfully locates a region of enhanced stability in the mass surface that is responsible for the rare-earth peak. For each scenario, we find that the change in the mass surface has qualitatively different features, thus future measurements can shed light on the type of environment in which the r process occurred.

  19. Modifying the processing and handling of frozen broccoli for increased sulforaphane formation.

    Science.gov (United States)

    Dosz, Edward B; Jeffery, Elizabeth H

    2013-09-01

    Frozen broccoli can provide a cheaper product, with a longer shelf life and less preparation time than fresh broccoli. We previously showed that several commercially available frozen broccoli products do not retain the ability to generate the cancer-preventative agent sulforaphane. We hypothesized that this was because the necessary hydrolyzing enzyme myrosinase was destroyed during blanching, as part of the processing that frozen broccoli undergoes. This study was carried out to determine a way to overcome loss of hydrolyzing activity. Industrial blanching usually aims to inactivate peroxidase, although lipoxygenase plays a greater role in product degradation during frozen storage of broccoli. Blanching at 86 °C or higher inactivated peroxidase, lipoxygenase, and myrosinase. Blanching at 76 °C inactivated 92% of lipoxygenase activity, whereas there was only an 18% loss in myrosinase-dependent sulforaphane formation. We considered that thawing frozen broccoli might disrupt membrane integrity, allowing myrosinase and glucoraphanin to come into contact. Thawing frozen broccoli for 9 h did not support sulforaphane formation unless an exogenous source of myrosinase was added. Thermal stability studies showed that broccoli root, as a source of myrosinase, was not more heat stable than broccoli floret. Daikon radish root supported some sulforaphane formation even when heated at 125 °C for 10 min, a time and temperature comparable to or greater than microwave cooking. Daikon radish (0.25%) added to frozen broccoli that was then allowed to thaw supported sulforaphane formation without any visual alteration to that of untreated broccoli. © 2013 Institute of Food Technologists®

  20. THE ROLE OF CRYOGENIC PROCESSES IN THE FORMATION OF LOESS DEPOSITS

    Directory of Open Access Journals (Sweden)

    Vyacheslav N. Konishchev

    2015-01-01

    Full Text Available The paper describes a new approach to the analysis of the genetic nature of mineral substances in loess deposits. In permafrost under the influence of multiple alternate freezing and thawing in dispersed deposits, quartz particles accumulate the 0.05-0.01 mm fraction, while feldspars are crushed to a coarse fraction of 0.1-0.05 mm. In dispersed sediments formed in temperate and warm climatic zones, the granulometric spectrum of quartz and feldspar has the opposite pattern. The proposed methodology is based on a differential analysis of the distribution of these minerals by the granulometric spectrum. We have proposed two criteria - the coefficient of cryogenic contrast (CCC and the coefficient of distribution of heavy minerals, which allow determination of the degree of participation of cryogenic processes in the formation of loess sediments and processes of aeolian or water sedimentation.

  1. Differential photoacoustic cell to study the wetting process during porous silicon formation

    Energy Technology Data Exchange (ETDEWEB)

    German Espinosa-Arbelaez, Diego [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Posgrado en Ciencia e Ingenieria de Materiales, Edificio de Posgrado, Coyoacan, CP 04530, Mexico D. F. (Mexico); Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Blvd Juriquilla 3001, Campus Juriquilla, CP 76230, Queretaro, Qro. (Mexico); Velazquez-Hernandez, Ruben [Division de Investigacion y Posgrado, Facultad de Ingenieria, Universidad Autonoma de Queretaro, Cerro de las Campanas, CP 76010, Queretaro, Qro (Mexico); Petricioli-Carranco, Julio; Quintero-Torres, Rafael; Rodriguez-Garcia, Mario Enrique [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Blvd Juriquilla 3001, Campus Juriquilla, CP 76230, Queretaro, Qro. (Mexico)

    2011-06-15

    This paper shows the in-situ study of the wetting process in Silicon during anodization process using an electrochemical Differential photoacoustic Cell (DPC). The Photoacoustic amplitude and phase signals were obtained for samples in air, ethanol, ethanol/HF and finally air. According to these results ethanol is responsible for a mechanical contact reducing the superficial tension and ethanol/HF produce the removing of the SiO{sub x} and SiO{sub 2}species on the Silicon surface. It was found that the DPC is a powerful technique to study the wet surface before the formation of the porous silicon layer (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. ANALYSIS OF NANO CHANNEL FORMATION IN QUARTZ CUBES BY LASER-INDUCED PROCESS

    Institute of Scientific and Technical Information of China (English)

    QIN S.J.; Li Wen J.

    2004-01-01

    A novel laser processing technique was developed for making channels in the nano regime in this paper. A Nd:YAG laser was used to dry fabricate micro channels (25μm~100μm diameter) in a 1 cm3 fused silica substrate by thermal-induced processing. By controlling the locations of these initiating micro channels on a silica cube, 1D-controllable self-connecting nano fractures can be formed as rectangular channels. These nano channels are smooth and with extremely high aspect ratio (~104 depth to width ratio). A possible mechanism is proposed to explain the formation of the nano channels. This laser-based nano channel fabrication technique is fast and inexpensive, and with potential applications in capillary electrophoresis and electro-osmosis driven nano-filtration.

  3. System of economics' security management in economic activity of meat processing enterprises formation

    Directory of Open Access Journals (Sweden)

    Iryna Sosnovska

    2015-11-01

    Full Text Available This article is devoted to creation of economics' security management system production and economic activity of meat current processing enterprises. The article reflects research results of various scientists scientific works regarding interpretation of economic security system and shows the lack of this concept single interpretation. There are summarized observation of current activities of meat processing plants specifics as a conclusion there are a large number of different programs and concepts that are embedded in large industrial plants, but they are internal and are not system using. The factors that determine the necessity of system of the economics' security management of enterprises formation are specified. This text highlighted objectives and principles of enterprises system economic security management that clearly reflect its effectiveness in the production of business enterprises.

  4. Application of Fractional Calculus to Reaction-Subdiffusion Processes and Morphogen Gradient Formation

    CERN Document Server

    Yuste, S B; Lindenberg, K

    2010-01-01

    It is a well known fact that subdiffusion equations in terms of fractional derivatives can be obtained from Continuous Time Random Walk (CTRW) models with long-tailed waiting time distributions. Over the last years various authors have shown that extensions of such CTRW models incorporating reactive processes to the mesoscopic transport equations may lead to non-intuitive reaction-subdiffusion equations. In particular, one such equation has been recently derived for a subdiffusive random walker subject to a linear (first-order) death process. We take this equation as a starting point to study the developmental biology key problem of morphogen gradient formation, both for the uniform case where the morphogen degradation rate coefficient (reactivity) is constant and for the non-uniform case (position-dependent reactivity). In the uniform case we obtain exponentially decreasing stationary concentration profiles and we study their robustness with respect to perturbations in the incoming morphogen flux. In the non...

  5. String networks with junctions in competition models

    Science.gov (United States)

    Avelino, P. P.; Bazeia, D.; Losano, L.; Menezes, J.; de Oliveira, B. F.

    2017-03-01

    In this work we give specific examples of competition models, with six and eight species, whose three-dimensional dynamics naturally leads to the formation of string networks with junctions, associated with regions that have a high concentration of enemy species. We study the two- and three-dimensional evolution of such networks, both using stochastic network and mean field theory simulations. If the predation, reproduction and mobility probabilities do not vary in space and time, we find that the networks attain scaling regimes with a characteristic length roughly proportional to t 1 / 2, where t is the physical time, thus showing that the presence of junctions, on its own, does not have a significant impact on their scaling properties.

  6. String networks with junctions in competition models

    CERN Document Server

    Avelino, P P; Losano, L; Menezes, J; de Oliveira, B F

    2016-01-01

    In this work we give specific examples of competition models, with six and eight species, whose three-dimensional dynamics naturally leads to the formation of string networks with junctions, associated with regions that have a high concentration of enemy species. We study the two- and three-dimensional evolution of such networks, both using stochastic network and mean field theory simulations. If the predation, reproduction and mobility probabilities do not vary in space and time, we find that the networks attain scaling regimes with a characteristic length roughly proportional to $t^{1/2}$, where $t$ is the physical time, thus showing that the presence of junctions, on its own, does not have a significant impact on their scaling properties.

  7. Ventifact Formation in the Mojave Desert: Field Analogs for Martian Processes

    Science.gov (United States)

    Laity, J. E.; Bridges, N. T.; Boyle, T. K.

    2001-01-01

    Two field studies in the Mojave Desert, California, shed light on processes of ventifact formation. The field sites are located on a ridge at Little Cowhole Mountain, which lies approximately 12 km south of Baker, and on an unnamed ridge situated along the northern boundary of the Mojave River Sink (Rasor Road site). The rocks at Little Cowhole Mountain are a blue-grey marble/dolomite, whereas those at Rasor Road are Miocene volcanic rocks (basalt). At both sites the abrasive agent is a fine-grained aeolian sand which was probably derived largely from the Mojave River. There are minimal modem inputs of sand to either site: abrasion occurs as a result of unique climatic and topographic conditions which allow pre-existing sand to be recycled from one aspect of the ridge to the other. Climatic conditions are well suited for ventifact formation. Owing, to the dry climate (marked by low average relative humidity, infrequent dew, and low annual rainfall), rates of chemical weathering are low. Where resurfacing of the rocks by sand abrasion proceeds at a rate greater than weathering, the ventifacts are considered "active." Active ventifacts are found atop and straddling the ridge crests, in the zone of maximum wind velocity and sediment supply. Inactive ventifacts occur where modem weathering Processes exceed abrasion rates; principally on the basal two-thirds of the hillslope, where wind velocity and sediment supply are lower. At intermediate locations between the slope base and crest, ventifacts are either active or inactive, depending on local conditions. The presence of relict ventifacts at the study sites, as well as elsewhere in the eastern Mojave Desert, suggests that the conditions for venti fact formation must have been more intense and extensive in the past. Together, the studies illustrate that the processes that interact to form ventifacts are highly complex, and must be studied at many scales. Small-scale effects, such as local topography, plant cover, or

  8. Formation of nanoporous pyrobitumen residues during maturation processes within the Barnett Shale (Fort Worth Basin)

    Science.gov (United States)

    Bernard, S.; Wirth, R.; Schreiber, A.; Schulz, H.-M.; Horsfield, B.

    2012-04-01

    Hydrocarbon generation processes occur within organic-rich shales as a response to increases in thermal maturation. Shale gas reservoir quality is thought to be largely dependent on the extent to which solid organic material has been converted to pore space during catagenesis. Although pores may drastically vary in variety and abundance within differing shales, the occurrence of nanopores within organic particles has recently been documented for an important number of gas shale systems (i.e., Barnett, Haynesville, Utica, Eagle Ford, Woodford, Horn River, Marcellus, Posidonia …). However, despite their ubiquitous nature, the formation and the geochemical nature of these nanoporous organic compounds remain unclear. Here, we present the characterization of samples from the organic-rich Mississippian Barnett shale gas system (Fort Worth Basin, Texas, USA) at varying stages of thermal maturation. Using a combination of compositional organic geochemistry and spectromicroscopy techniques, including synchrotron-based scanning transmission X-ray microscopy (STXM - data collected using the CLS 10ID-1 STXM beamline) and transmission electron microscopy (TEM), we document a net increase in sample geochemical heterogeneity with increasing maturity. In addition to the presence of bitumen in samples of oil window maturity, very likely genetically derived from thermally degraded kerogen, the formation of nanoporous pyrobitumen has been inferred for samples of gas window maturity, likely resulting from the formation of gaseous hydrocarbons by secondary cracking of bitumen compounds. By providing in-situ insights into the fate of bitumen and pyrobitumen as a response to the thermal evolution of the macromolecular structure of kerogen, the present contribution constitutes an important step towards better constraining hydrocarbon generation processes occurring within unconventional gas shale systems.

  9. Processes and controlling factors of polygenetic dolomite formation in the Transdanubian Range, Hungary: a synopsis

    Science.gov (United States)

    Haas, János; Hips, Kinga; Budai, Tamás; Győri, Orsolya; Lukoczki, Georgina; Kele, Sándor; Demény, Attila; Poros, Zsófia

    2016-06-01

    In the Transdanubian Range (Hungary), dolostone and dolomitic limestone appear in a number of sedimentary successions formed from the Late Permian to the Late Triassic in various depositional settings and under various diagenetic conditions, whereas only a negligible amount of dolomite was detected in the post-Triassic formations. Seven dolomite-bearing units representing ramp, small and large carbonate platforms, and intraplatform basin settings are presented in this synopsis. In most cases, multi-stage and polygenetic dolomitization was inferred. The main mass of the dolostones was formed via near-surface diagenetic processes, which were commonly preceded by the formation of synsedimentary dolomite. Accordingly, surficial conditions that prevailed during sediment deposition controlled the dolomite-forming processes and thus the lateral extension and the time span of dolomitization. The area of episodic subaerial exposure was a critical controlling factor of the lateral extension of the near-surface dolomite genesis, whereas its temporal extension was mostly governed by climate. Burial diagenesis usually resulted in only moderate dolomitization, either in connection with compactional fluid flow or via thermal convection. The Triassic fault zones provided conduits for fluid flow that led to both replacive dolomitization and dolomite cement precipitation. In the Late Triassic extensional basins, synsedimentary fault-controlled dolomitization of basinal deposits was reconstructed.

  10. Simulation of coupled THM process in surrounding rock mass of nuclear waste repository in argillaceous formation

    Institute of Scientific and Technical Information of China (English)

    蒋中明; 陈永贵

    2015-01-01

    To investigate and analyze the thermo-hydro-mechanical (THM) coupling phenomena of a surrounding rock mass in an argillaceous formation, a nuclear waste disposal concept in drifts was represented physically in an in-situ test way. A transversely isotropic model was employed to reproduce the whole test process numerically. Parameters of the rock mass were determined by laboratory and in-situ experiments. Based on the numerical simulation results and in-situ test data, the variation processes of pore water pressure, temperature and deformation of surrounding rock were analyzed. Both the measured data and numerical results reveal that the thermal perturbation is the principal driving force which leads to the variation of pore water pressure and deformations in the surrounding rock. The temperature, pore pressure and deformation of rock mass change rapidly at each initial heating stage with a constant heating power. The temperature field near the heater borehole is relatively steady in the subsequent stages of the heating phase. However, the pore pressure and deformation fields decrease gradually with temperature remaining unchanged condition. It also shows that a transversely isotropic model can reproduce the THM coupling effects generating in the near-field of a nuclear waste repository in an argillaceous formation.

  11. PRELIMNARY STUDY ON THE EFFECT OF SUBSTANCE P IN THE PROCESS OF FORMATION OF NEEDLING SENSATION

    Institute of Scientific and Technical Information of China (English)

    Xu Guolong; Shen Dekai; Liu Xiangguo

    2001-01-01

    Object: To study the effect of SP in the process of formation of needling sensation in the rat. Methods:The pain threshold was determined by inducing rat's tail swing reaction when the electrical stimulation was gradually increased to a certain extent via two electrodes inserted in the bilateral sides of the tail. Right Zusanli (ST 36) was stimulated electrically for 30 min by setting the stimulating parameters as continuous waves, frequency of 20 Hz and a suitable strength (just generating slight muscular tremor). The relative SP contents of the spinal cord and the small intestine were displayed by using immunohistochemical method and evaluated using gray density value. The effect of "Zusanli"-injection of SP on pain threshold was observed by injecting 25 μL of SP (5 nm) into the bilateral ST 36. In ST 36, both the pain threshold and SP content of the spinal dorsal horn on the EA side increased significantly (P<portant role in the process of formation of needling sensation in the primary nerve center.

  12. Neural Correlates of Auditory Processing, Learning and Memory Formation in Songbirds

    Science.gov (United States)

    Pinaud, R.; Terleph, T. A.; Wynne, R. D.; Tremere, L. A.

    Songbirds have emerged as powerful experimental models for the study of auditory processing of complex natural communication signals. Intact hearing is necessary for several behaviors in developing and adult animals including vocal learning, territorial defense, mate selection and individual recognition. These behaviors are thought to require the processing, discrimination and memorization of songs. Although much is known about the brain circuits that participate in sensorimotor (auditory-vocal) integration, especially the ``song-control" system, less is known about the anatomical and functional organization of central auditory pathways. Here we discuss findings associated with a telencephalic auditory area known as the caudomedial nidopallium (NCM). NCM has attracted significant interest as it exhibits functional properties that may support higher order auditory functions such as stimulus discrimination and the formation of auditory memories. NCM neurons are vigorously dr iven by auditory stimuli. Interestingly, these responses are selective to conspecific, relative to heterospecific songs and artificial stimuli. In addition, forms of experience-dependent plasticity occur in NCM and are song-specific. Finally, recent experiments employing high-throughput quantitative proteomics suggest that complex protein regulatory pathways are engaged in NCM as a result of auditory experience. These molecular cascades are likely central to experience-associated plasticity of NCM circuitry and may be part of a network of calcium-driven molecular events that support the formation of auditory memory traces.

  13. Utilizing Stable Isotopes and Isotopic Anomalies to Study Early Solar System Formation Processes

    Science.gov (United States)

    Simon, Justin

    2017-01-01

    Chondritic meteorites contain a diversity of particle components, i.e., chondrules and calcium-, aluminum-rich refractory inclusions (CAIs), that have survived since the formation of the Solar System. The chemical and isotopic compositions of these materials provide a record of the conditions present in the protoplanetary disk where they formed and can aid our understanding of the processes and reservoirs in which solids formed in the solar nebula, an important step leading to the accretion of planetesimals. Isotopic anomalies associated with nucleosynthetic processes are observed in these discrete materials, and can be compared to astronomical observations and astrophysical formation models of stars and more recently proplyds. The existence and size of these isotopic anomalies are typically thought to reflect a significant state of isotopic heterogeneity in the earliest Solar System, likely left over from molecular cloud heterogeneities on the grain scale, but some could also be due to late stellar injection. The homogenization of these isotopic anomalies towards planetary values can be used to track the efficiency and timescales of disk wide mixing,

  14. Effects of stacking fault energy on defect formation process in face-centered cubic metals

    Science.gov (United States)

    Okita, Taira; Yang, Yingjuan; Hirabayashi, Junichi; Itakura, Mitsuhiro; Suzuki, Katsuyuki

    2016-05-01

    To elucidate the effect of stacking fault energies (SFEs) on defect formation by the collision cascade process for face-centred cubic metals, we used six sets of interatomic potentials with different SFEs while keeping the other properties almost identical. Molecular dynamic simulations of the collision cascade were carried out using these potentials with primary knock-on atom energies (EPKA) of 10 and 20 keV at 100 K. Neither the number of residual defects nor the size distributions for both self-interstitial atom (SIA) type and vacancy type clusters were affected by the difference in the SFE. In the case of EPKA = 20 keV, the ratio of glissile SIA clusters increased as the SFE decreased, which was not expected by a prediction based on the classical dislocation theory. The trend did not change after annealing at 1100 K for 100 ps. For vacancy clusters, few stacking fault tetrahedrons (SFTs) formed before the annealing. However, lower SFEs tended to increase the SFT fraction after the annealing, where large vacancy clusters formed at considerable densities. The findings of this study can be used to characterise the defect formation process in low SFE metals such as austenitic stainless steels.

  15. Interspecies interactions result in enhanced biofilm formation by co-cultures of bacteria isolated from a food processing environment

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Raghupathi, Prem Krishnan; Herschend, Jakob

    2015-01-01

    examined for multispecies biofilm formation. Eight strains from each sampling site were chosen and all possible combinations of four member co-cultures were tested for enhanced biofilm formation at 15°C and 24°C. In approximately 20% of the multispecies consortia grown at 15°C, the biofilm formation......Bacterial attachment and biofilm formation can lead to poor hygienic conditions in food processing environments. Furthermore, interactions between different bacteria may induce or promote biofilm formation. In this study, we isolated and identified a total of 687 bacterial strains from seven...... different locations in a meat processing environment and evaluated their biofilm formation capability. A diverse group of bacteria was isolated and most were classified as poor biofilm producers in a Calgary biofilm device assay. Isolates from two sampling sites, the wall and the meat chopper, were further...

  16. An induced junction photovoltaic cell

    Science.gov (United States)

    Call, R. L.

    1974-01-01

    Silicon solar cells operating with induced junctions rather than diffused junctions have been fabricated and tested. Induced junctions were created by forming an inversion layer near the surface of the silicon by supplying a sheet of positive charge above the surface. Measurements of the response of the inversion layer cell to light of different wavelengths indicated it to be more sensitive to the shorter wavelengths of the sun's spectrum than conventional cells. The greater sensitivity occurs because of the shallow junction and the strong electric field at the surface.

  17. Targeting Holliday junctions by origin DNA-binding protein of herpes simplex virus type 1.

    Science.gov (United States)

    Moiseeva, E D; Bazhulina, N P; Gursky, Y G; Grokhovsky, S L; Surovaya, A N; Gursky, G V

    2017-03-01

    In the present paper, the interactions of the origin binding protein (OBP) of herpes simplex virus type 1 (HSV1) with synthetic four-way Holliday junctions (HJs) were studied using electrophoresis mobility shift assay and the FRET method and compared with the interactions of the protein with duplex and single-stranded DNAs. It has been found that OBP exhibits a strong preference for binding to four-way and three-way DNA junctions and possesses much lower affinities to duplex and single-stranded DNAs. The protein forms three types of complexes with HJs. It forms complexes I and II which are reminiscent of the tetramer and octamer complexes with four-way junction of HJ-specific protein RuvA of Escherichia coli. The binding approaches saturation level when two OBP dimers are bound per junction. In the presence of Mg(2+) ions (≥2 mM) OBP also interacts with HJ in the stacked arm form (complex III). In the presence of 5 mM ATP and 10 mM Mg(2+) ions OBP catalyzes processing of the HJ in which one of the annealed oligonucleotides has a 3'-terminal tail containing 20 unpaired thymine residues. The observed preference of OBP for binding to the four-way DNA junctions provides a basis for suggestion that OBP induces large DNA structural changes upon binding to Box I and Box II sites in OriS. These changes involve the bending and partial melting of the DNA at A+T-rich spacer and also include the formation of HJ containing Box I and Box II inverted repeats and flanking DNA sequences.

  18. Process research of non-CZ silicon material. Quarterly report No. 2, January 1, 1984-March 31, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R.B.

    1984-05-01

    In this program, which started November 4, 1983, the fabrication of solar cells on N-base material using simultaneous diffusion of liquid boron and phosphorus dopants to from the desired P/sup +/NN/sup +/ cell structure is being studied. This simultaneous junction formation method is being compared to the sequential junction formation method where phosphorus is diffused to form an N/sup +/N back surface field followed by a boron diffusion for the P/sup +/N front junction. During the contract, the sensitivity of the process parameters will also be studied; and a cost analysis of the new junction formation process will be performed using SAMICS-IPEG methodology.

  19. Microemulsions and Aggregation Formation in Extraction Processes for Used Nuclear Fuel: Thermodynamic and Structural Studies

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Mikael [Univ. of California, Irvine, CA (United States)

    2016-05-04

    Advanced nuclear fuel cycles rely on successful chemical separation of various elements in the used fuel. Numerous solvent extraction (SX) processes have been developed for the recovery and purification of metal ions from this used material. However, the predictability of process operations has been challenged by the lack of a fundamental understanding of the chemical interactions in several of these separation systems. For example, gaps in the thermodynamic description of the mechanism and the complexes formed will make predictions very challenging. Recent studies of certain extraction systems under development and a number of more established SX processes have suggested that aggregate formation in the organic phase results in a transformation of its selectivity and efficiency. Aggregation phenomena have consistently been interfering in SX process development, and have, over the years, become synonymous with an undesirable effect that must be prevented. This multiyear, multicollaborative research effort was carried out to study solvation and self-organization in non-aqueous solutions at conditions promoting aggregation phenomena. Our approach to this challenging topic was to investigate extraction systems comprising more than one extraction reagent where synergy of the metal ion could be observed. These systems were probed for the existence of stable microemulsions in the organic phase, and a number of high-end characterization tools were employed to elucidate the role of the aggregates in metal ion extraction. The ultimate goal was to find connections between synergy of metal ion extraction and reverse micellar formation. Our main accomplishment for this project was the expansion of the understanding of metal ion complexation in the extraction system combining tributyl phosphate (TBP) and dibutyl phosphoric acid (HDBP). We have found that for this system no direct correlation exists for the metal ion extraction and the formation of aggregates, meaning that the

  20. Flame experiments at the advanced light source: new insights into soot formation processes.

    Science.gov (United States)

    Hansen, Nils; Skeen, Scott A; Michelsen, Hope A; Wilson, Kevin R; Kohse-Höinghaus, Katharina

    2014-05-26

    The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics Beamline of the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory(1-4). This video demonstrates how the complex chemical structures of laboratory-based model flames are analyzed using flame-sampling mass spectrometry with tunable synchrotron-generated vacuum-ultraviolet (VUV) radiation. This experimental approach combines isomer-resolving capabilities with high sensitivity and a large dynamic range(5,6). The first part of the video describes experiments involving burner-stabilized, reduced-pressure (20-80 mbar) laminar premixed flames. A small hydrocarbon fuel was used for the selected flame to demonstrate the general experimental approach. It is shown how species' profiles are acquired as a function of distance from the burner surface and how the tunability of the VUV photon energy is used advantageously to identify many combustion intermediates based on their ionization energies. For example, this technique has been used to study gas-phase aspects of the soot-formation processes, and the video shows how the resonance-stabilized radicals, such as C3H3, C3H5, and i-C4H5, are identified as important intermediates(7). The work has been focused on soot formation processes, and, from the chemical point of view, this process is very intriguing because chemical structures containing millions of carbon atoms are assembled from a fuel molecule possessing only a few carbon atoms in just milliseconds. The second part of the video highlights a new experiment, in which an opposed-flow diffusion flame and synchrotron-based aerosol mass spectrometry are used to study the chemical composition of the combustion-generated soot particles(4). The experimental results indicate that the widely accepted H-abstraction-C2H2-addition (HACA) mechanism is not the sole molecular growth process responsible for the formation

  1. Degradation of tert-butyl formate and its intermediates by an ozone/UV process.

    Science.gov (United States)

    Garoma, Temesgen; Gurol, Mirat D; Thotakura, Lalitha; Osibodu, Olufisayo

    2008-12-01

    In this paper, the oxidation of tert-butyl formate (TBF) in aqueous solution by an ozone/UV process was described. The oxidation process was investigated experimentally in a semibatch reactor. The results of the study indicated that the ozone/UV process was very effective in oxidizing TBF. tert-Butyl alcohol (TBA), hydroxy-iso-butyraldehyde (HiBA), acetone, formaldehyde, and formic acid were identified as major primary intermediates during the oxidation of TBF. About 90% organic carbon balance was obtained indicating that most reaction intermediates have been identified and quantified. Some of the primary intermediates were also oxidized in the ozone/UV system. Accordingly, HiBA, acetone, formaldehyde, and formic acid were the primary intermediates of TBA oxidation. The oxidation of acetone in the ozone/UV system generated formaldehyde, pyruvaldehyde, acetic acid, formic acid as primary intermediates. It was also observed that the reaction intermediates formed during the oxidation of TBF react well in the ozone/UV system and complete mineralization could be achieved by the process.

  2. Processes of benthic foraminiferal fossil assemblage formation on the continental slope

    Energy Technology Data Exchange (ETDEWEB)

    Loubere, P. (Northern Illinois Univ., DeKalb (United States))

    1991-03-01

    Theoretical analysis of benethic foraminiferal fossil assemblage formation shows that the assemblage eventually preserved in the sediments is an integrated result of species' test production rate, microhabitat behavior, and biogeochemical processes that control the probability of species' test preservation. The biogeochemical processes that influence test preservation in slope sediments are controlled by the flux of organic carbon to the sea-bed and the botton water oxygen concentration. These variables also affect the depth of the biotic habitation zone in the sediments. Therefore, organic carbon flux and bottom water oxygen content should be reflected in benthic foraminiferal fossil assemblages for both ecologic and taphonomic reasons. An integrated study of fossil assemblage generation was conducted on the Gulf of Mexico continental slope using box cores collected along depth transects across the oxygen minimum, and using live and dead assemblage analysis combined with {sup 210}Pb measurements to quantify biotic activity in the sediments and pore water nutrient and metals analysis to quantify biogeochemical processes acting in the sediment habitation zone. The results show that the size of the habitation zone and live standing stock are influenced by organic carbon flux and oxygen supply to the sea-bed. The fossil assemblage is created progressively through the upper 10-20 cm of sediment and biologichemically driven test destruction (taphonomic process) is important in determining the assemblage that enters the geologic record.

  3. Microstructure Formation Mechanism During a Novel Semisolid Rheo-rolling Process of AZ91 Magnesium Alloy

    Institute of Scientific and Technical Information of China (English)

    Zhanyong ZHAO; Renguo GUAN; Xiang WANG; Chunming LIU

    2013-01-01

    A novel semisolid rheo-rolling process of AZ91 alloy was proposed.The microstructure formation mechanism of AZ91 magnesium alloy during the process was studied.The results reveal that the eruptive nucleation and the heterogeneous nucleation exist.During the grain growth process,the grain breakage took place and transformed into fine spherical or rosette grains on the sloping plate gradually,the other grain growth style is direct globular growth.Due to the secondary crystallization of the remnant liquids in the roll gap,the microstructure of the strip becomes finer with the increment of the casting temperature from 650 ℃ to 690 ℃.But when the casting temperature reached 710 ℃,a part of the liquid alloy transformed into the eutectic phases,and the primary grains ripened to form coarse dendrites.In the casting temperature range from 650 ℃ to 690 ℃,AZ91 alloy strip with fine spherical or rosette grains was prepared by the proposed process.

  4. The link between rare earth peak formation and the astrophysical site of the $r$ process

    CERN Document Server

    Mumpower, M R; Surman, R; Steiner, A W

    2016-01-01

    The primary astrophysical source of the rare earth elements is the rapid neutron capture process ($r$ process). The rare earth peak that is seen in the solar $r$-process residuals has been proposed to originate as a pile-up of nuclei during the end of the $r$ process. We introduce a new method utilizing Monte Carlo studies of nuclear masses in the rare earth region, that includes self-consistently adjusting $\\beta$-decay rates and neutron capture rates, to find the mass surfaces necessary for the formation of the rare earth peak. We demonstrate our method with two types of astrophysical scenarios, one corresponding conditions typical of core-collapse supernova winds and one corresponding to conditions typical of the ejection of the material from the tidal tails of neutron star mergers. In each type of astrophysical conditions, this method successfully locates a region of enhanced stability in the mass surface that is responsible for the rare earth peak. For each scenario, we find that the change in the mass s...

  5. Removal of disinfection by-products formation potential by biologically intensified process

    Institute of Scientific and Technical Information of China (English)

    AN Dong; LI Wei-guang; CUI Fu-yi; HE Xin; ZHANG Jin-song

    2005-01-01

    The removal of disinfection by-products formation potential(DBPFP) in artificially intensified biological activated carbon(IBAC) process which is developed on the basis of traditional ozone granular activated carbon was evaluated. By IBAC removals of 31% and 68% for THMFP and HAAFP were obtained respectively. Under identical conditions, the removals of the same substances were 4% and 32% respectively only by the granular activated carbon(GAC) process. Compared with GAC, the high removal rates of the two formed potential substances were due to the increasing of bioactivity of the media and the synergistic capabilities of biological degradation cooperating with activated carbon adsorption of organic compounds. A clear linear correlation ( R2 = 0.9562 and R2 = 0.9007) between DOC HAAFP removal rate and Empty Bed Contact Time(EBCT) of IBAC process was observed, while that between THMFP removal rate and EBCT of GAC was R2 = 0.9782. In addition certain linear correlations between THMFP, HAAFP and UV254 ( R2 = 0.855 and R2 = 0.7702) were found for the treated water. For IBAC process there are also more advantages such as long backwashing cycle time, low backwashing intensity and prolonging activated carbon lifetime and so on.

  6. International Processes of Education Policy Formation: An Analytic Framework and the Case of Plan 2021 in El Salvador

    Science.gov (United States)

    Edwards, D. Brent, Jr.

    2013-01-01

    This article uses multiple perspectives to frame international processes of education policy formation and then applies the framework to El Salvador's Plan 2021 between 2003 and 2005. These perspectives are policy attraction, policy negotiation, policy imposition, and policy hybridization. Research reveals that the formation of Plan 2021 was the…

  7. International Processes of Education Policy Formation: An Analytic Framework and the Case of Plan 2021 in El Salvador

    Science.gov (United States)

    Edwards, D. Brent, Jr.

    2013-01-01

    This article uses multiple perspectives to frame international processes of education policy formation and then applies the framework to El Salvador's Plan 2021 between 2003 and 2005. These perspectives are policy attraction, policy negotiation, policy imposition, and policy hybridization. Research reveals that the formation of Plan 2021 was the…

  8. Ion-induced Processing of Cosmic Silicates: A Possible Formation Pathway to GEMS

    Science.gov (United States)

    Jäger, C.; Sabri, T.; Wendler, E.; Henning, Th.

    2016-11-01

    Ion-induced processing of dust grains in the interstellar medium and in protoplanetary and planetary disks plays an important role in the entire dust cycle. We have studied the ion-induced processing of amorphous MgFeSiO4 and Mg2SiO4 grains by 10 and 20 keV protons and 90 keV Ar+ ions. The Ar+ ions were used to compare the significance of the light protons with that of heavier, but chemically inert projectiles. The bombardment was performed in a two-beam irradiation chamber for in situ ion-implantation at temperatures of 15 and 300 K and Rutherford Backscattering Spectroscopy to monitor the alteration of the silicate composition under ion irradiation. A depletion of oxygen from the silicate structure by selective sputtering of oxygen from the surface of the grains was observed in both samples. The silicate particles kept their amorphous structure, but the loss of oxygen caused the reduction of ferrous (Fe2+) ions and the formation of iron inclusions in the MgFeSiO4 grains. A few Si inclusions were produced in the iron-free magnesium silicate sample pointing to a much less efficient reduction of Si4+ and formation of metallic Si inclusions. Consequently, ion-induced processing of magnesium-iron silicates can produce grains that are very similar to the glassy grains with embedded metals and sulfides frequently observed in interplanetary dust particles and meteorites. The metallic iron inclusions are strong absorbers in the NIR range and therefore a ubiquitous requirement to increase the temperature of silicate dust grains in IR-dominated astrophysical environments such as circumstellar shells or protoplanetary disks.

  9. A low-energy chilled ammonia process exploiting controlled solid formation for post-combustion CO2 capture.

    Science.gov (United States)

    Sutter, Daniel; Gazzani, Matteo; Mazzotti, Marco

    2016-10-20

    A new ammonia-based process for CO2 capture from flue gas has been developed, which utilizes the formation of solid ammonium bicarbonate to increase the CO2 concentration in the regeneration section of the process. Precipitation, separation, and dissolution of the solid phase are realized in a dedicated process section, while the packed absorption and desorption columns remain free of solids. Additionally, the CO2 wash section applies solid formation to enable a reduction of the wash water consumption. A rigorous performance assessment employing the SPECCA index (Specific Primary Energy Consumption for CO2 Avoided) has been implemented to allow for a comparison of the overall energy penalty between the new process and a standard ammonia-based capture process without solid formation. A thorough understanding of the relevant solid-solid-liquid-vapor phase equilibria and an accurate modeling of them have enabled the synthesis of the process, and have inspired the development of the optimization algorithm used to screen a wide range of operating conditions in equilibrium-based process simulations. Under the assumptions on which the analysis is based, the new process with controlled solid formation achieved a SPECCA of 2.43 MJ kgCO2(-1), corresponding to a reduction of 17% compared to the process without solid formation (with a SPECCA of 2.93 MJ kgCO2(-1)). Ways forward to confirm this significant improvement, and to increase the accuracy of the optimization are also discussed.

  10. Experimental demonstration of a format-flexible single-carrier coherent receiver using data-aided digital signal processing.

    Science.gov (United States)

    Elschner, Robert; Frey, Felix; Meuer, Christian; Fischer, Johannes Karl; Alreesh, Saleem; Schmidt-Langhorst, Carsten; Molle, Lutz; Tanimura, Takahito; Schubert, Colja

    2012-12-17

    We experimentally demonstrate the use of data-aided digital signal processing for format-flexible coherent reception of different 28-GBd PDM and 4D modulated signals in WDM transmission experiments over up to 7680 km SSMF by using the same resource-efficient digital signal processing algorithms for the equalization of all formats. Stable and regular performance in the nonlinear transmission regime is confirmed.

  11. The process of ghost-rock karstification and its role in the formation of cave systems

    Science.gov (United States)

    Dubois, C.; Quinif, Y.; Baele, J.-M.; Barriquand, L.; Bini, A.; Bruxelles, L.; Dandurand, G.; Havron, C.; Kaufmann, O.; Lans, B.; Maire, R.; Martin, J.; Rodet, J.; Rowberry, M. D.; Tognini, P.; Vergari, A.

    2014-04-01

    This paper presents an extensive review of the process of ghost-rock karstification and highlights its role in the formation of cave systems. The process integrates chemical weathering and mechanical erosion and extends a number of existing theories pertaining to continental landscape development. It is a two stage process that differs in many respects from the traditional single-stage process of karstification by total removal. The first stage is characterised by chemical dissolution and removal of the soluble species. It requires low hydrodynamic energy and creates a ghost-rock feature filled with residual alterite. The second stage is characterised by mechanical erosion of the undissolved particles. It requires high hydrodynamic energy and it is only then that open galleries are created. The transition from the first stage to the second is driven by the amount of energy within the thermodynamic system. The process is illustrated by detailed field observations and the results of the laboratory analyses of samples taken from the karstotype area around Soignies in southern Belgium. Thereafter, a series of case studies provide a synthesis of field observations and laboratory analyses from across western Europe. These studies come from geologically distinct parts of Belgium, France, Italy, and the United Kingdom. The process of ghost-rock karstification challenges a number of axioms associated with the process of karstification by total removal. On the basis of the evidence presented it is argued that it is no longer acceptable to use karst morphologies as a basis with which to infer specific karstogenetic processes and it is no longer necessary for a karst system to relate to base level as ghost-rock karstification proceeds along transmissive pathways in the rock. There is also some evidence to suggest that ghost-rock karstification may be superseded by karstification by total removal, and vice versa, according to the amount of energy within the thermodynamic system

  12. ADAMTS-10 and -6 differentially regulate cell-cell junctions and focal adhesions

    Science.gov (United States)

    Cain, Stuart A.; Mularczyk, Ewa J.; Singh, Mukti; Massam-Wu, Teresa; Kielty, Cay M.

    2016-01-01

    ADAMTS10 and ADAMTS6 are homologous metalloproteinases with ill-defined roles. ADAMTS10 mutations cause Weill-Marchesani syndrome (WMS), implicating it in fibrillin microfibril biology since some fibrillin-1 mutations also cause WMS. However little is known about ADAMTS6 function. ADAMTS10 is resistant to furin cleavage, however we show that ADAMTS6 is effectively processed and active. Using siRNA, over-expression and mutagenesis, it was found ADAMTS6 inhibits and ADAMTS10 is required for focal adhesions, epithelial cell-cell junction formation, and microfibril deposition. Either knockdown of ADAMTS6, or disruption of its furin processing or catalytic sites restores focal adhesions, implicating its enzyme activity acts on targets in the focal adhesion complex. In ADAMTS10-depleted cultures, expression of syndecan-4 rescues focal adhesions and cell-cell junctions. Recombinant C-termini of ADAMTS10 and ADAMTS6, both of which induce focal adhesions, bind heparin and syndecan-4. However, cells overexpressing full-length ADAMTS6 lack heparan sulphate and focal adhesions, whilst depletion of ADAMTS6 induces a prominent glycocalyx. Thus ADAMTS10 and ADAMTS6 oppositely affect heparan sulphate-rich interfaces including focal adhesions. We previously showed that microfibril deposition requires fibronectin-induced focal adhesions, and cell-cell junctions in epithelial cultures. Here we reveal that ADAMTS6 causes a reduction in heparan sulphate-rich interfaces, and its expression is regulated by ADAMTS10. PMID:27779234

  13. Control of disinfection by-product formation using ozone-based advanced oxidation processes.

    Science.gov (United States)

    Chen, Kuan-Chung; Wang, Yu-Hsiang

    2012-01-01

    The effects of ozone dosage, water temperature and catalyst addition in an ozonation-fluidized bed reactor (O3/FBR) on treated water quality and on the control of chlorinated and ozonated disinfection by-products (DBPs) were investigated. A biofiltration column was used to evaluate its removal efficiency on biodegradable organic matter and to reduce DBP formation. The Dong-Gang River, polluted by agricultural and domestic wastewater in Pingtung, Taiwan, was used as the water source. The treated water quality in terms of dissolved organic carbon (DOC), biodegradable DOC, ultraviolet absorbance at 254 nm (UV254) and specific UV absorbance (SUVA) improved with increasing ozone and catalyst dosages. Catalytic ozonation was more effective than ozonation alone at reducing the formation of DBPs at a given dosage. Experimental results show that water temperature had little effect on the treated water quality with the O3/FBR system used in this study (p > 0.05). The combination of O3/FBR and the biofiltration process effectively decreased the amount ofDBP precursors. The concentration of total trihalomethanes (TTHMs) was less than the maximum contaminant level (MCL) requirement, which is 80 microg/L, for all treated waters and the concentration of five haloacetic acids (HAA5) fell below 60 microg/L with an ozone dosage higher than 2.5 mg/L.

  14. Formation and fate of marine snow: small-scale processes with large- scale implications

    Directory of Open Access Journals (Sweden)

    Thomas Kiørboe

    2001-12-01

    Full Text Available Marine snow aggregates are believed to be the main vehicles for vertical material transport in the ocean. However, aggregates are also sites of elevated heterotrophic activity, which may rather cause enhanced retention of aggregated material in the upper ocean. Small-scale biological-physical interactions govern the formation and fate of marine snow. Aggregates may form by physical coagulation: fluid motion causes collisions between small primary particles (e.g. phytoplankton that may then stick together to form aggregates with enhanced sinking velocities. Bacteria may subsequently solubilise and remineralise aggregated particles. Because the solubilization rate exceeds the remineralization rate, organic solutes leak out of sinking aggregates. The leaking solutes spread by diffusion and advection and form a chemical trail in the wake of the sinking aggregate that may guide small zooplankters to the aggregate. Also, suspended bacteria may enjoy the elevated concentration of organic solutes in the plume. I explore these small-scale formation and degradation processes by means of models, experiments and field observations. The larger scale implications for the structure and functioning of pelagic food chains of export vs. retention of material will be discussed.

  15. Constraints on Feedback Processes during the Formation of Early-type Galaxies

    Science.gov (United States)

    Trevisan, M.; Ferreras, I.; de La Rosa, I. G.; La Barbera, F.; de Carvalho, R. R.

    2012-06-01

    Galaxies are found to obey scaling relations between a number of observables. These relations follow different trends at the low- and high-mass ends. The processes driving the curvature of scaling relations remain uncertain. In this Letter, we focus on the specific family of early-type galaxies, deriving the star formation histories of a complete sample of visually classified galaxies from Sloan Digital Sky Survey DR7 over the redshift range 0.01 < z < 0.025, covering a stellar mass interval from 109 to 3 × 1011 M ⊙. Our sample features the characteristic "knee" in the surface brightness versus mass distribution at M sstarf ~ 3 × 1010 M ⊙ . We find a clear difference between the age and metallicity distributions of the stellar populations above and beyond this knee, which suggests a sudden transition from a constant, highly efficient mode of star formation in high-mass galaxies, gradually decreasing toward the low-mass end of the sample. At fixed mass, our early-type sample is more efficient in building up the stellar content at early times in comparison to the general population of galaxies, with half of the stars already in place by redshift z ~ 2 for all masses. The metallicity-age trend in low-mass galaxies is not compatible with infall of metal-poor gas, suggesting instead an outflow-driven relation.

  16. Constraints on feedback processes during the formation of early-type galaxies

    CERN Document Server

    Trevisan, Marina; de la Rosa, Ignacio; La Barbera, Francesco; de Carvalho, Reinaldo

    2012-01-01

    Galaxies are found to obey scaling relations between a number of observables. These relations follow different trends at the low- and the high-mass ends. The processes driving the curvature of scaling relations remain uncertain. In this letter, we focus on the specific family of early-type galaxies, deriving the star formation histories of a complete sample of visually classified galaxies from SDSS-DR7 over the redshift range 0.01formation in high-mass galaxies, gradually decreasing towards the low-mass end of the sample. At fixed mass, our early-type sample is more efficient in building up the stellar content...

  17. Empirical analysis of the lane formation process in bidirectional pedestrian flow

    Science.gov (United States)

    Feliciani, Claudio; Nishinari, Katsuhiro

    2016-09-01

    This paper presents an experimental study on pedestrian bidirectional streams and the mechanisms leading to spontaneous lane formation by examining the flow formed by two groups of people walking toward each other in a mock corridor. Flow ratio is changed by changing each group size while maintaining comparable total flow and density. By tracking the trajectories of each pedestrian and analyzing the data obtained, five different phases were recognized as contributing to the transition from unidirectional to bidirectional flow including the spontaneous creation and dissolution of lanes. It has been shown that a statistical treatment is required to understand the fundamental characteristics of pedestrian dynamics and some two-dimensional quantities such as order parameter and rotation range were introduced to allow a more complete analysis. All the quantities observed showed a clear relationship with flow ratio and helped distinguishing between the different characteristic phases of the experiment. Results show that balanced bidirectional flow becomes the most stable configuration after lanes are formed, but the lane creation process requires pedestrians to laterally move to a largest extent compared to low flow-ratio configurations. This finding allows us to understand the reasons why balanced bidirectional flow is efficient at low densities, but quickly leads to deadlock formation at high densities.

  18. CONSTRAINTS ON FEEDBACK PROCESSES DURING THE FORMATION OF EARLY-TYPE GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Trevisan, M. [Departamento de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo/IAG, Sao Paulo (Brazil); Ferreras, I. [MSSL, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom); De La Rosa, I. G. [Instituto de Astrofisica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); La Barbera, F. [INAF-Osservatorio Astronomico di Capodimonte, Napoli (Italy); De Carvalho, R. R., E-mail: trevisan@astro.iag.usp.br [Instituto Nacional de Pesquisas Espaciais/MCT, S. J. dos Campos (Brazil)

    2012-06-20

    Galaxies are found to obey scaling relations between a number of observables. These relations follow different trends at the low- and high-mass ends. The processes driving the curvature of scaling relations remain uncertain. In this Letter, we focus on the specific family of early-type galaxies, deriving the star formation histories of a complete sample of visually classified galaxies from Sloan Digital Sky Survey DR7 over the redshift range 0.01 < z < 0.025, covering a stellar mass interval from 10{sup 9} to 3 Multiplication-Sign 10{sup 11} M{sub Sun }. Our sample features the characteristic 'knee' in the surface brightness versus mass distribution at M{sub *} {approx} 3 Multiplication-Sign 10{sup 10} M{sub Sun} . We find a clear difference between the age and metallicity distributions of the stellar populations above and beyond this knee, which suggests a sudden transition from a constant, highly efficient mode of star formation in high-mass galaxies, gradually decreasing toward the low-mass end of the sample. At fixed mass, our early-type sample is more efficient in building up the stellar content at early times in comparison to the general population of galaxies, with half of the stars already in place by redshift z {approx} 2 for all masses. The metallicity-age trend in low-mass galaxies is not compatible with infall of metal-poor gas, suggesting instead an outflow-driven relation.

  19. Transformation of humic acid and halogenated byproduct formation in UV-chlorine processes.

    Science.gov (United States)

    Li, Tong; Jiang, Yan; An, Xiaoqiang; Liu, Huijuan; Hu, Chun; Qu, Jiuhui

    2016-10-01

    The synergistic effect of ultraviolet light (UV) and chlorine on the structural transformation of Humic Acid (HA) and formation of chloro-disinfection byproducts (DBPs) in water were investigated, with chlorination as a reference. The transformation and mineralization of HA were enhanced upon co-exposure to UV and chlorine. Electron spin resonance (ESR) studies revealed that hydroxyl radical (OH) and chlorine radical (Cl) were predominant active species in a pH range from 4 to 7, while Cl dominated at pH 2 and pH higher than 7. The impact of different radicals on the transformation of HA was investigated by UV254, fluorescence and TOC measurements. OH were found to be responsible for the removal of chromophoric groups and mineralization of HA, while Cl mainly reacted with HA and intermediates from HA degradation. Due to the competitive and synergistic reaction of OH and Cl with HA, higher removal of HA and lower formation of chloro-DBPs appeared in UV-chlorine than chlorination, thus the combined UV-chlorine processes should be a promising method for water purification.

  20. Hall effect on a Merging Formation Process of a Field-Reversed Configuration

    Science.gov (United States)

    Kaminou, Yasuhiro; Guo, Xuehan; Inomoto, Michiaki; Ono, Yasushi; Horiuchi, Ritoku

    2015-11-01

    Counter-helicity spheromak merging is one of the formation methods of a Field-Reversed Configuration (FRC). In counter-helicity spheromak merging, two spheromaks with opposing toroidal fields merge together, through magnetic reconnection events and relax into a FRC, which has no or little toroidal field. This process contains magnetic reconnection and a relaxation phenomena, and the Hall effect has some essential effects on these process because the X-point in the magnetic reconnection or the O-point of the FRC has no or little magnetic field. However, the Hall effect as both global and local effect on counter-helicity spheromak merging has not been elucidated. In this poster, we conducted 2D/3D Hall-MHD simulations and experiments of counter-helicity spheromak merging. We find that the Hall effect enhances the reconnection rate, and reduces the generation of toroidal sheared-flow. The suppression of the ``slingshot effect'' affects the relaxation process. We will discuss details in the poster.

  1. Formation of NiAl intermetallic coatings on stainless steel by a conventional duplex process

    Energy Technology Data Exchange (ETDEWEB)

    Ashrafizadeh, F.; Hajdaie, A.H.; Miraghaie, S. [Isfahan Univ. of Technology, Dept. of Materials Engineering, Isfahan (Iran, Islamic Republic of)

    2003-07-01

    Nickel-aluminide coatings were formed on 403 stainless steel samples by a duplex process incorporating electro-deposition and diffusion coating. Nickel was deposited by conventional electroplating on some specimens to appropriate thickness. The uncoated and nickel-coated samples were then aluminized by a powder pack method. Process parameters including pack composition, temperature, coating and annealing cycles were optimized in terms of the intermetallic phases produced in the near surface layers. The coatings and interface regions were characterized by optical and scanning electron microscopy, x-ray diffraction, glow discharge spectroscopy, micro-hardness measurements and pin-on-disc wear testing. Experimental results indicate that deposition of nickel on 403 steel before aluminizing produced two distinct layers of NiAl and FeAl on the surface and below that, respectively. The formation of these phases depends on the coating and annealing temperatures. The intermetallic phase NiAl on steel substrate acts as an alumina forming material to increase the life of aluminized layer. The intermetallic coatings produced by this duplex process had dense structure and excellent adhesion to the substrate; these are suitable candidates for high temperature applications of steel components under oxidation and hot corrosion conditions. (author)

  2. Formation of Poultry Meat Flavor by Heating Process and Lipid Oxidation

    Directory of Open Access Journals (Sweden)

    Maijon Purba

    2014-09-01

    Full Text Available Flavor is an important factor in the acceptance of food. Flavor of poultry meat is naturally formed through a specific process of heating, where various chemical reactions complex occurred among nonvolatile precursors in fatty tissue or in lean tissue. The main flavor in the form of volatile and nonvolatile components play a major influence on the acceptance of various processed meat, especially the taste. Removal of sulfur components decreases meat flavor (meaty, while removal of carbonyl compounds decrease the specific flavor and increases common flavor of the meat. Poultry meat has a fairly high fat content that easily generates lipid oxidation. Lipid oxidation in poultry meat is a sign that the meat was damaged and caused off odor. Addition of antioxidants in the diet can inhibit lipid oxidation in the meat. Lipids interaction with proteins and carbohydrates is unavoidable during the thermal processing of food, causing the appearance of volatile components. The main reaction in meat flavor formation mechanism is Maillard reaction followed by Stecker reaction and degradation of lipids and thiamine. They involve in the reaction between carbonyl and amine components to form flavor compounds, which enhance the flavor of poultry meat.

  3. Monitoring process of human keloid formation based on second harmonic generation imaging

    Science.gov (United States)

    Jiang, X. S.; Chen, S.; Chen, J. X.; Zhu, X. Q.; Zheng, L. Q.; Zhuo, S. M.; Wang, D. J.

    2011-09-01

    In this paper, the morphological variation of collagen among the whole dermis from keloid tissue was investigated using second harmonic generation (SHG) microscopy. In the deep dermis of keloids, collagen bundles show apparently regular gap. In the middle dermis, the collagen bundles are randomly oriented and loosely arranged in the pattern of fine mesh while the collagen bundles are organized in a parallel manner in the superficial dermis near the epidermis. The developed parameters COI and BD can be used to further quantitatively describe these changes. Our results demonstrate the potential of SHG microscopy to understand the formation process of human keloid scar at the cellular level through imaging collagen variations in different depth of dermis.

  4. Coalescing Aid Influences on Acrylic Latexes Property and Film Formation Process

    Directory of Open Access Journals (Sweden)

    Wang Yi

    2016-01-01

    Full Text Available The coalescing aid of propylene glycol phenyl ether (PPh influences on the latexes system and its film formation process have been demonstrated in this paper. The latexes with different Tg are synthesized by seeded semicontinuous emulsion polymerization. The PPh have a significant impact on the water evaporation stage, in which PPh decreased the water evaporation rate for a low Tg latex system but accelerated the rate for a high Tg latex. This result was quantified using Routh-Russel model which was a useful model for the prediction of the latex particle deformation mechanisms. The different amounts of PPh can change the latex particle deformation mechanisms. The TGA results show that the PPh still exist in the latexes films during drying. The microstructures of the latex film which dry under 70°C with the PPh for different time display that the PPh can accelerate the polymer molecules motion and the diffusion rate for the latex coalescence stage.

  5. The Process of price formation and the skewness of asset returns

    CERN Document Server

    Reimann, S

    2006-01-01

    Distributions of assets returns exhibit a slight skewness. In this note we show that our model of endogenous price formation \\cite{Reimann2006} creates an asymmetric return distribution if the price dynamics are a process in which consecutive trading periods are dependent from each other in the sense that opening prices equal closing prices of the former trading period. The corresponding parameter $\\alpha$ is estimated from daily prices from 01/01/1999 - 12/31/2004 for 9 large indices. For the S&P 500, the skewness distribution of all its constituting assets is also calculated. The skewness distribution due to our model is compared with the distribution of the empirical skewness values of the ingle assets.

  6. Teachers and the religious socialization of adolescents: facilitation of meaningful religious identity formation processes.

    Science.gov (United States)

    Cohen-Malayev, Maya; Schachter, Elli P; Rich, Yisrael

    2014-02-01

    This study investigated the effects of religious education on student religious identity over and above parent religiosity by examining student perceptions of two aspects of teacher functioning: teacher caring and teacher as role-model. We posited that effects of these variables on students' religious identity are mediated by student perceptions that the school provides a non-alienating religious atmosphere and meaningful religious studies. Participants were 2691 male and female students (grades 9-12) in 152 classes of 25 schools from the Jewish public-religious sector in Israel. Results indicate that in addition to their parents' religiosity, adolescents' perceptions of their teachers as role models and their religious studies as meaningful are important variables affecting their religious identity. Moreover, this research suggests that religious identity formation processes flourish in an educational environment which students perceive as accommodating religious exploration. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  7. A formative approach to strategic message targeting through soap operas: using selective processing theories.

    Science.gov (United States)

    Dutta-Bergman, Mohan J

    2006-01-01

    In the past 2 decades, soap operas have been used extensively to attain prosocial change in other parts of the world. The role of the soap opera in achieving social change has become of special interest to strategic health message designers and planners in the United States. Before a strategic approach is implemented, however, researchers need to conduct formative research to interrogate the viability of soap operas and guide communication strategies. This article constructs a profile of the soap opera user who is younger, less educated, and earns less than the nonuser. Using selective processing theory, I argue that the health-oriented individual is most likely to remember health content from soap operas and incorporate the content in future behavior. Strategic media planning and message construction guidelines are provided for the use of soap operas as vehicles for reinforcing positive health behaviors and introducing new behaviors in the health oriented segment.

  8. Synthesis and formation mechanism of pinnoite by the phase transition process

    Science.gov (United States)

    Lin, Feng; Dong, Yaping; Peng, Jiaoyu; Wang, Liping; Li, Wu

    2016-06-01

    Pinnoite (MgB2O(OH)6) for the first time was synthesized using the solid-liquid-solid conversion method. The effects of reaction time, pH value and concentrations of magnesium and borate were investigated. Pinnoite was synthesized under the optimum condition of 8 mmol hungtsaoite and 1% boric acid solution at 80 °C. The products were determined using X-ray diffraction, Fourier-transform infrared spectroscopy, TG-DSC and a UV-vis spectrometer. The change processes of the surface morphology of pinnoite were investigated using scanning electron microscopy. In addition, the formation mechanism of pinnoite was discussed according to the changes in the content of precipitation and pH value.

  9. Formation process of a strong water-repellent alumina surface by the sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Feng Libang, E-mail: lepond@hotmail.com [School of Mechatronic Engineering, Lanzhou Jiaotong University, 88 West Anning Road, Lanzhou 730070 (China); Li Hui; Song Yongfeng; Wang Yulong [School of Mechatronic Engineering, Lanzhou Jiaotong University, 88 West Anning Road, Lanzhou 730070 (China)

    2010-03-01

    A novel strong water-repellent alumina thin film is fabricated by chemically adsorbing stearic acid (STA) layer onto the porous and roughened aluminum film coated with polyethyleneimine (PEI). The formation process and the structure of the strong water-repellent alumina film are investigated by means of contact angle measurement and atomic force microscope (AFM). Results show that the water contact angles for the alumina films increase with the increase of the immersion time in the boiling water, and meanwhile, the roughness of the alumina films increases with the dissolution of the boehmite in the boiling water. Finally, the strong water-repellent film with a high water contact angle of 139.1 deg. is obtained when the alumina films have distinct roughened morphology with some papillary peaks and porous structure. Moreover, both the roughened structure and the hydrophobic materials of the STA endow the alumina films with the strong water-repellence.

  10. Formation process of a strong water-repellent alumina surface by the sol-gel method

    Science.gov (United States)

    Feng, Libang; Li, Hui; Song, Yongfeng; Wang, Yulong

    2010-03-01

    A novel strong water-repellent alumina thin film is fabricated by chemically adsorbing stearic acid (STA) layer onto the porous and roughened aluminum film coated with polyethyleneimine (PEI). The formation process and the structure of the strong water-repellent alumina film are investigated by means of contact angle measurement and atomic force microscope (AFM). Results show that the water contact angles for the alumina films increase with the increase of the immersion time in the boiling water, and meanwhile, the roughness of the alumina films increases with the dissolution of the boehmite in the boiling water. Finally, the strong water-repellent film with a high water contact angle of 139.1° is obtained when the alumina films have distinct roughened morphology with some papillary peaks and porous structure. Moreover, both the roughened structure and the hydrophobic materials of the STA endow the alumina films with the strong water-repellence.

  11. Formation Processes of Nanocomposite Strengthening Particles in Rapidly Quenched Al-Sc-Zr Alloys

    Directory of Open Access Journals (Sweden)

    A.V. Kotko

    2012-03-01

    Full Text Available Decomposition processes of supersaturated solid solution of aluminium alloys alloyed with Sc and Zr have been studied in the work. The binary hypereutectic Al-Sc alloys, hyperperitectic Al-Zr alloys and ternary Al-Sc-Zr alloys were chosen. Alloys were obtained by the melt-spinning. Melts were quenched from temperatures of Т = 1000 C and Т = 1400 ºC. The study of the structure of rapidly solidifyed binary Al alloys alloyed with Sc and Zr showed that the crystallization of anomalously supersaturated solid solution (Tquen. = 1400 ºC or the crystallization with the formation of "fan" structure (Tquen. = 1000 ºC are possible depending on the quenching temperature of the melt. The decomposition of anomalously supersaturated solid solution is continuous, with the precipitation of nano-sized spherical Al3X (X-Sc, Zr particles of L12-ordered phase which is isomorphous to matrix. It was found that the loss of thermal stability of Al-Sc alloys is due to the loss of coherence of the strengthening Al3Sc phase. In Al-Zr alloys the loss of strength is due to the formation of a stable tetragonal DO23-ordered A13Zr phase. After co-alloying of Al by Sc and Zr a bimodal grained structure was observed for the hypereutectic ternary alloy (Tquen. = 400ºC. Nano-sized grains of 50-60 nm were present on the boundaries of 1-2 µm large-sized grains. TEM shows the formation of nanocomposite Al3Zr/Al3Sc particles. The formation of Al3Zr shell changes the nature of the interfacial fit of the particle with the matrix and slows down the decomposition during the coalescence. Ternary Al-Sc-Zr alloys have significantly higher thermal stability during aging as compared to binary Al-Sc and Al-Zr alloys. Decomposition processes of supersaturated solid solution of aluminium alloys alloyed with Sc and Zr have been studied in the work. The binary hypereutectic Al-Sc alloys, hyperperitectic Al-Zr alloys and ternary Al-Sc-Zr alloys were chosen. Alloys were

  12. The Formation Process of Silico-Ferrite of Calcium (SFC) from Binary Calcium Ferrite

    Science.gov (United States)

    Ding, Xiang; Guo, Xing-Min

    2014-08-01

    Silico-ferrite of calcium (SFC) is a significant equilibrium crystalline phase in the Fe2O3-CaO-SiO2 (FCS) ternary system and a key bonding phase in the sintering process of fine iron ore. In this work, the formation process of SFC from binary calcium ferrite has been determined by X-ray diffraction and field-emission scanning electron microscopy. Experiments were carried out under air at 1473 K (1200 °C) by adding SiO2 and Fe2O3 into CaO·Fe2O3 (CF). It was found that the formation of SFC is dominated by solid-state reactions in the FCS ternary system, in which Fe2O3 reacts with CaO·Fe2O3 to form the binary calcium ferrite phase. The chemical composition of binary calcium ferrite is Ca2.5Fe15.5O25 and approximately Ca2Fe12O20 (CaO·3Fe2O3). Then Si4+ and Ca2+ ions take the place of Fe3+ ion in preference located on the octahedral layers which belongs to (0 0 18) plane of binary calcium ferrite. The crystal structure of binary calcium ferrite gradually transforms from orthorhombic to triclinic, and the grain is refined with the addition of silica due to the smaller radius of Si4+ ion. A solid solution SFC forms completely when the content of SiO2 reaches approximately 3.37 wt pct at 1473 K (1200 °C).

  13. Formation of Nb/sub 3/Al in powder processed Nb-Al superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, P.E.

    1987-05-01

    In high magnetic fields, the critical current density is strongly dependent on the upper critical field, which is determined primarily by the stoichiometry of the Nb/sub 3/Al. The critical temperature (T/sub c/), like the upper critical field, is considered to be a measure of the ''intrinsic'' quality of the superconductor, indicating the stoichiometry, order, and strain. If the A15 phase is stoichiometric and well ordered, a high T/sub c/ (and high H/sub C/sub 2//) is expected, regardless of the volume fraction of superconductor. On the other hand, if sigma phase is present with the A15, the resultant composition gradient across the sigma-A15 interface(s) requires that some of the A15 be off-stoichiometric, and therefore that the T/sub c/ (and H/sub C/sub 2//) be low. Thus the extent of the A15 (Nb/sub 3/Al) reaction and the quality of the A15 formed are interdependent. This work focuses on the factors that control the extent of Nb/sub 3/Al formation in Nb/Al powder wires. The morphology and content of the reacted and unreacted wires are studied in optical, SEM, and TEM micrographs. Critical current density data and its dependence on processing are explained in terms of the unreacted microstructure and its effect on the extent of Nb/sub 3/Al formation. As a method of improving the critical current density, a new variation of the conventional powder process for wire manufacturing is developed and tested.

  14. Formation of carbon vacancy in 4H silicon carbide during high-temperature processing

    Science.gov (United States)

    Ayedh, H. M.; Bobal, V.; Nipoti, R.; Hallén, A.; Svensson, B. G.

    2014-01-01

    As-grown and pre-oxidized silicon carbide (SiC) samples of polytype 4H have been annealed at temperatures up to 1950 °C for 10 min duration using inductive heating, or at 2000 °C for 30 s using microwave heating. The samples consisted of a n-type high-purity epitaxial layer grown on 4° off-axis ⟨0001⟩ n+-substrate and the evolution of the carbon vacancy (VC) concentration in the epitaxial layer was monitored by deep level transient spectroscopy via the characteristic Z1/2 peak. Z1/2 appears at ˜0.7 eV below the conduction band edge and arises from the doubly negative charge state of VC. The concentration of VC increases strongly after treatment at temperatures ≥ 1600 °C and it reaches almost 1015 cm-3 after the inductive heating at 1950 °C. A formation enthalpy of ˜5.0 eV is deduced for VC, in close agreement with recent theoretical predictions in the literature, and the entropy factor is found to be ˜5 k (k denotes Boltzmann's constant). The latter value indicates substantial lattice relaxation around VC, consistent with VC being a negative-U system exhibiting considerable Jahn-Teller distortion. The microwave heated samples show evidence of non-equilibrium conditions due to the short duration used and display a lower content of VC than the inductively heated ones. Finally, concentration-versus-depth profiles of VC favour formation in the "bulk" of the epitaxial layer as the prevailing process and not a Schottky type process at the surface.

  15. Cosmochemical evidence for astrophysical processes during the formation of our solar system.

    Science.gov (United States)

    MacPherson, Glenn J; Boss, Alan

    2011-11-29

    Through the laboratory study of ancient solar system materials such as meteorites and comet dust, we can recognize evidence for the same star-formation processes in our own solar system as those that we can observe now through telescopes in nearby star-forming regions. High temperature grains formed in the innermost region of the solar system ended up much farther out in the solar system, not only the asteroid belt but even in the comet accretion region, suggesting a huge and efficient process of mass transport. Bi-polar outflows, turbulent diffusion, and marginal gravitational instability are the likely mechanisms for this transport. The presence of short-lived radionuclides in the early solar system, especially (60)Fe, (26)Al, and (41)Ca, requires a nearby supernova shortly before our solar system was formed, suggesting that the Sun was formed in a massive star-forming region similar to Orion or Carina. Solar system formation may have been "triggered" by ionizing radiation originating from massive O and B stars at the center of an expanding HII bubble, one of which may have later provided the supernova source for the short-lived radionuclides. Alternatively, a supernova shock wave may have simultaneously triggered the collapse and injected the short-lived radionuclides. Because the Sun formed in a region where many other stars were forming more or less contemporaneously, the bi-polar outflows from all such stars enriched the local region in interstellar silicate and oxide dust. This may explain several observed anomalies in the meteorite record: a near absence of detectable (no extreme isotopic properties) presolar silicate grains and a dichotomy in the isotope record between (26)Al and nucleosynthetic (nonradiogenic) anomalies.

  16. THE PROCESS OF TRANSPLANTATION OF INSTITUTIONS AS THE FORMATION OF A NEW ECONOMIC SYSTEM

    Directory of Open Access Journals (Sweden)

    D. D. Burkaltseva

    2016-01-01

    Full Text Available In the article the problems of "transplant" for post-socialist countries. Institutional framework of the transformation of society has its own characteristics. Its institutions can ensure the eff ectiveness of economic development, as a rule, in the short run. After performing their tasks, these institutions are transformed or disposed of as such, it has already completed its mission.Purposes / tasks. The aim of this paper is to transplant institutions.Article tasks: to explore and identify: The term "transplantation"; Factors that cause an ineffi cient choice of institutions; The main tasks of institutional transformation in market transformation of the economy.Methodology. The methodological basis of the study is the dialectical method of scientifi c knowledge, a systematic and institutional approach to the study of transplantation of institutions as the formation of a new economic system.Results. The result of the successful application of the transplanted institutions must be economic and social security, the formation of eff ective collective decision-making mechanisms, the growth of state budget revenues and other socio-economic indicators. The institutions should be assessed as a specifi c kind of public goods. Their characteristic is a public good is important to consider the probability of positive and negative impacts that are measured in terms of various social strata, as well as determine the eff ectiveness of the existence of diff erent variants of the institutions adopted to regulate certain processes.Conclusions / importance. From the point of view of the determination of the economic security of its external and internal factors and risks, the main tasks of institutional transformation in market transformation of the economy are: the creation of favorable conditions for the implementation of tasks in the context of globalization and integration; maximum realization of competitive advantages of national priorities, economic

  17. High-temperature superconductor vertically-stacked Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

    Yoshinaga, Y; Kito, T; Izawa, S; Maruyama, M; Inoue, M; Fujimaki, A; Hayakawa, H [Department of Quantum Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2002-12-01

    We study vertically-stacked interface-treated Josephson junctions (ITJs). The barriers of ITJs are formed by Ar ion etching and subsequent annealing, not by depositing an artificial barrier. We have investigated the dependences of the junction properties on the processing parameters. It is found that the control of junction properties can be realized by controlling the incidence angle of Ar, and that the higher accelerating voltage of Ar reduces leakage paths in a barrier. Moreover, we have successfully eliminated the excess current of the junctions using the PrGaO{sub 3} (PGO) doping process. We conclude that the conjunction of the interface treatment and the PGO doping technique leads to highly integrated Josephson circuits.

  18. High-temperature superconductor vertically-stacked Josephson junctions

    CERN Document Server

    Yoshinaga, Y; Izawa, S; Maruyama, M; Inoue, M; Fujimaki, A; Hayakawa, H

    2002-01-01

    We study vertically-stacked interface-treated Josephson junctions (ITJs). The barriers of ITJs are formed by Ar ion etching and subsequent annealing, not by depositing an artificial barrier. We have investigated the dependences of the junction properties on the processing parameters. It is found that the control of junction properties can be realized by controlling the incidence angle of Ar, and that the higher accelerating voltage of Ar reduces leakage paths in a barrier. Moreover, we have successfully eliminated the excess current of the junctions using the PrGaO sub 3 (PGO) doping process. We conclude that the conjunction of the interface treatment and the PGO doping technique leads to highly integrated Josephson circuits.

  19. Regulation of Gap Junction Dynamics by UNC-44/ankyrin and UNC-33/CRMP through VAB-8 in C. elegans Neurons.

    Directory of Open Access Journals (Sweden)

    Lingfeng Meng

    2016-03-01

    Full Text Available Gap junctions are present in both vertebrates and invertebrates from nematodes to mammals. Although the importance of gap junctions has been documented in many biological processes, the molecular mechanisms underlying gap junction dynamics remain unclear. Here, using the C. elegans PLM neurons as a model, we show that UNC-44/ankyrin acts upstream of UNC-33/CRMP in regulation of a potential kinesin VAB-8 to control gap junction dynamics, and loss-of-function in the UNC-44/UNC-33/VAB-8 pathway suppresses the turnover of gap junction channels. Therefore, we first show a signal pathway including ankyrin, CRMP, and kinesin in regulating gap junctions.

  20. Impact of Process Parameters on the Laser-induced Nanoparticle Formation During Keyhole Welding under Remote Conditions

    Science.gov (United States)

    Scholz, Tobias; Dickmann, Klaus; Ostendorf, Andreas

    The interaction between the vapor plume and the incident laser radiation affects remote laser welding. Relating to laser systems with an emitted wavelength around 1 μm, a significant loss mechanism can be traced back to the extinction by laser-induced particle formation. Due to the tight coupling between the particle formation and the evaporation rate inside the keyhole, the particle formation shows a strong dependence on the keyhole geometry and thus on process parameters (e.g. feed rate and laser beam power). In order to verify the relationship between particle formation and process parameters, the beam of a broadband LED was guided through the vapor plume during the welding processes with a fiber laser. The attenuated probe beam was analyzed in dependence on the wavelength. In addition, the propagation of the vapor plume was investigated by using high speed imaging.

  1. Geochemistry of fossiliferous carbonate concretions from the Cretaceous Santana Formation - assessing the role of microbial processes

    Science.gov (United States)

    Heimhofer, Ulrich; Schwark, Lorenz; Ariztegui, Daniel; Martill, David M.; Immenhauser, Adrian

    2010-05-01

    Exceptional fossil preservation (incl. soft-tissue phosphatization) within organic-rich black shales is often associated with the formation of a protective carbonate shell surrounding the fossil specimen. Whereas the mechanisms controlling soft-tissue mineralization during the earliest stage of fossilization are considerably well understood (e.g. Briggs and Kear, 1993), only limited information is currently available on the complex biogeochemical processes which lead to the precipitation of the concretionary carbonate mantle around the fossils. This study focuses on the organic and inorganic geochemistry of carbonate concretions derived from black shale deposits of the Early Cretaceous Santana Formation, Araripe Basin, NE Brazil (Martill, 1993; Heimhofer et al. 2008). This konservat-type fossil lagerstätte is world famous for its fossiliferous concretions hosting an exceptionally preserved fish and reptile fauna. The principle aim is twofold including (1) identification of the type and source of organic matter trapped within the Santana concretions and (2) assessment of the different microbial or microbially-mediated processes associated with successive concretion growth during early burial. Based on sedimentological evidence and palaeoenvironmental considerations, the involvement of a prokaryotic mat in early fossilization of the Santana biota has been proposed (Martill, 1988). At this stage, 3 different carbonate concretions hosting fossil fish remains (incl. Notelops brama, Calamopleurus sp. und an unknown specimen) have been analysed with a combined approach including organic molecular geochemistry, high-resolution stable isotope analysis, micro-XRF scanning and sedimentary petrography. Petrographic inspection shows a distinct zonal pattern of the carbonate shell surrounding the fossils. The innermost zone I shows an undulating and discontinuous lamination superimposed on a clotted fabric. Zone II is characterized by the frequent abundance of finely dispersed

  2. Effects of low-intensity pulsed ultrasound on new trabecular bone during bone-tendon junction healing in a rabbit model: a synchrotron radiation micro-CT study.

    Directory of Open Access Journals (Sweden)

    Hongbin Lu

    Full Text Available This study was designed to evaluate the effects of low-intensity pulsed ultrasound on bone regeneration during the bone-tendon junction healing process and to explore the application of synchrotron radiation micro computed tomography in three dimensional visualization of the bone-tendon junction to evaluate the microarchitecture of new trabecular bone. Twenty four mature New Zealand rabbits underwent partial patellectomy to establish a bone-tendon junction injury model at the patella-patellar tendon complex. Animals were then divided into low-intensity pulsed ultrasound treatment (20 min/day, 7 times/week and placebo control groups, and were euthanized at week 8 and 16 postoperatively (n = 6 for each group and time point. The patella-patellar tendon specimens were harvested for radiographic, histological and synchrotron radiation micro computed tomography detection. The area of the newly formed bone in the ultrasound group was significantly greater than that of control group at postoperative week 8 and 16. The high resolution three dimensional visualization images of the bone-tendon junction were acquired by synchrotron radiation micro computed tomography. Low-intensity pulsed ultrasound treatment promoted dense and irregular woven bone formation at week 8 with greater bone volume fraction, number and thickness of new trabecular bone but with lower separation. At week 16, ultrasound group specimens contained mature lamellar bone with higher bone volume fraction and thicker trabeculae than that of control group; however, there was no significant difference in separation and number of the new trabecular bone. This study confirms that low-intensity pulsed ultrasound treatment is able to promote bone formation and remodeling of new trabecular bone during the bone-tendon junction healing process in a rabbit model, and the synchrotron radiation micro computed tomography could be applied for three dimensional visualization to quantitatively evaluate

  3. Recognition of Nucleic Acid Junctions Using Triptycene-Based Molecules

    OpenAIRE

    Barros, Stephanie A.; Chenoweth, David M.

    2014-01-01

    Nucleic acid modulation by small molecules is an essential process across the kingdoms of life. Targeting nucleic acids with small molecules represents a significant challenge at the forefront of chemical biology. Nucleic acid junctions are ubiquitous structural motifs in nature and in designed materials. Herein, we describe a new class of structure specific nucleic acid junction stabilizers based on a triptycene scaffold. Triptycenes provide significant stabilization of DNA and RNA three-way...

  4. Variable conformation of GAP junctions linking bone cells: a transmission electron microscopic study of linear, stacked linear, curvilinear, oval, and annular junctions.

    Science.gov (United States)

    Shapiro, F

    1997-10-01

    There is a marked variability in the conformation of bone cell gap junctions in newborn murine cortical bone as defined by transmission electron microscopy (TEM). Studies were done in newborn BALB/c mouse and Sprague-Dawley rat femurs and tibias. Femoral and tibial cortices were dissected into 1 mm3 fragments and prepared in standardized fashion using modified Karnovsky fixation, 7.5% EDTA decalcification, 1% osmium tetroxide-sym collidine buffer with 1% lanthanum nitrate postfixation, Epon resin, 60 nm sections, lead citrate/uranyl acetate staining, and examination at 60 kV. Previous TEM descriptions of bone junctions have, with rare exceptions, noted only isolated linear or mildly curvilinear structures. In this study we noted gap junctional shapes on thin-section TEM preparations of osteoblasts and osteocytes to be extremely variable and complex encompassing linear, curvilinear, stacked linear, oval, and annular conformations. Multiple observations revealed linear gap junctions linking surface osteoblast cell bodies; linear, curvilinear, stacked linear, and oval junctions linking osteoblast processes in osteoid; linear and curvilinear junctions where cell processes joined with osteocyte cell bodies and each of the five conformations linking osteocyte processes within canaliculi. The annular junctions were found within osteoblast and osteocyte cytoplasm and in osteocyte cell processes within canaliculi. The annular junctions are intracellular, degenerating structures which appear as ultrastructural markers of gap junction involution. The more complex shapes reported here must be considered in (1) interpreting quantitative studies using freeze-fracture replicas, thin sections, and confocal microscopy immunolabeled junction connexin-43 components and (2) assessing gap junction biogenesis and turnover. 3-D reconstruction of bone junctions will enhance our understanding of these complex conformations.

  5. Supernova Neutrino-Effects on R-Process Nucleosynthesis in Black Hole Formation

    CERN Document Server

    Sasaqui, T; Balantekin, A B

    2005-01-01

    Stars with a wide range of masses provide a variety of production sites for intermediate-to-heavy mass elements. Very massive stars with mass $\\geq 8 M_{\\odot}$ culminate their evolution by supernova explosions which are presumed to be the most viable candidate astrophysical sites of r-process nucleosynthesis. If the models for the supernova r-process are correct, then nucleosynthesis results could also pose a significant constraint on the remnant of supernova explosions, $i.e.$ neutron star or black hole. In the case of very massive core collapse, a remnant stellar black hole is thought to be formed. Intense neutrino flux from the neutronized core and the neutrino sphere might suddenly cease during the Kelvin-Helmholtz cooling phase because of the black hole formation. It is interesting to explore observable consequences of such a neutrino flux truncation. Arguments have recently been given in the literature that even the neutrino mass may be determined from the time delay of deformed neutrino energy spectru...

  6. Formation and growth process of dislocation loops in zircaloys under electron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakamichi, Haruo; Kinoshita, Chiken; Yasuda, Kazuhiro; Fukada, Shinya [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering

    1997-11-01

    We have investigated the formation and growth process of dislocation loops in Zircaloys (Zrys) under electron irradiation using a high voltage electron microscope (HVEM). Dislocation loops are of great importance to degradation phenomena in fuel claddings, such as irradiation growth and reduced ductility in light water reactors. TEM specimens of three kinds of Zircaloys (Zry-2, Zry-4 and improved Zry-2) were irradiated with 1 MeV electrons at temperatures from 320 K to 970 K in the HVEM. Interstitial-type dislocation loops with the Burgers vector b = 1/3<112-bar0> were formed on the pyramidal or the prismatic planes at the beginning of irradiation. It was found that the nucleation and growth process of those loops follows the kinetics based on the di-interstitial model where di-interstitials act as the nuclei of interstitial dislocation loops. Based on this model, migration energies of interstitials and vacancies were determined to be 0.15-0.22 eV and 1.0-1.2 eV, respectively, from the irradiation temperature dependence of the density and the growth rate of loops. (author)

  7. Influence of Powder Metallurgical Processing Routes on Phase Formations in a Multicomponent NbSi-Alloy

    Science.gov (United States)

    Seemüller, C.; Hartwig, T.; Mulser, M.; Adkins, N.; Wickins, M.; Heilmaier, M.

    2014-09-01

    Refractory metal silicide composites on the basis of Nbss-Nb5Si3 have been investigated as potential alternatives for nickel-base superalloys for years because of their low densities and good high-temperature strengths. NbSi-based composites are typically produced by arc-melting or casting. Samples in this study, however, were produced by powder metallurgy because of the potential for near net-shape component fabrication with very homogeneous microstructures. Either gas atomized powder or high-energy mechanically alloyed elemental powders were compacted by powder injection molding or hot isostatic pressing. Heat treatments were applied for phase stability evaluation. Slight compositional changes (oxygen, nitrogen, or iron) introduced by the processing route, i.e., powder production and consolidation, can affect phase formations and phase transitions during the process. Special focus is put on the distinction between different silicides (Nb5Si3 and Nb3Si) and silicide modifications (α-, β-, and γ-Nb5Si3), respectively. These were evaluated by x-ray diffraction and energy-dispersive spectroscopy measurements with the additional inclusion of thermodynamic calculations using the calculated phase diagram method.

  8. La biblioteca escolar y la formación lectora School Library and Reader Formation Process

    Directory of Open Access Journals (Sweden)

    Patricia Calonje Daly

    2008-06-01

    Full Text Available Este artículo discute los conceptos ideológicamente legitimados que dan sustento a las nociones socialmente predominantes acerca de la relación entre formación lectora y biblioteca escolar y, alternativamente, plantea las condiciones que deberían ser asumidas por esa misma relación para que se torne enriquecedora: grosso modo, el sentido de las prácticas que comprometen a la totalidad de la comunidad educativa, la creación de entornos favorables, las interacciones con diversos tipos de texto, las nuevas relaciones con los textos, las formas de organización diferentes, el carácter de los procesos para hacerse lector, el sentido del conocimiento, la biblioteca y los maestros y los bibliotecarios como mediadores.This article points out the relation between the school library and the reader formation as legitimated concepts that support predominant notions. Indeed, it supports the conditions that should be assumed by that same relationship for enriching the learning process. In this case, the educative community should be the main participant in this relation. It can create favorable environments, interactions with multiple kinds of texts, new relationships with texts, different kinds of organization, making the process of becoming a reader, knowledge purpose, finally library and teachers, and librarians as mediators.

  9. The oxide phase formation modelling at the deoxidization process in yttrium steels

    Directory of Open Access Journals (Sweden)

    Петро Степанович Харлашин

    2016-11-01

    Full Text Available In recent years approaches to high-quality steel production have significantly changed. The influence of the oxide and sulfide non-metallic inclusions should be noted in particular. Modifying is followed with the change in the inclusions chemical composition, they are generally being MnS inclusions and fragile oxidic inclusions. Modification results in the formation of spherical oxides and yttrium sulfides that don’t deform at rolling. Nowadays modifying with rare-earth elements has no broad application because of the use of cheaper lime which possesses similar efficiency. That is why REM are applied generally as microparticles, and their deoxidating and desulphurizing abilities are limited because of their high cost in comparison with the expenditures on modern extra oven processing of steel. Nonmetallic inclusions hardly influence on «volume» processes of plastic deformation and hardening. The use of rare-earth metals and their combinations as nonmetallic inclusions modifiers appear to have considerable promise. Therefore the modelling and further calculation of oxygen and sulfur interaction with yttrium in metal were carried out

  10. BIOFILM FORMATION OF Vibrio cholerae ON STAINLESS STEEL USED IN FOOD PROCESSING.

    Science.gov (United States)

    Fernández-Delgado, Milagro; Rojas, Héctor; Duque, Zoilabet; Suárez, Paula; Contreras, Monica; García-Amado, M Alexandra; Alciaturi, Carlos

    2016-01-01

    Vibrio cholerae represents a significant threat to human health in developing countries. This pathogen forms biofilms which favors its attachment to surfaces and its survival and transmission by water or food. This work evaluated the in vitro biofilm formation of V. cholerae isolated from clinical and environmental sources on stainless steel of the type used in food processing by using the environmental scanning electron microscopy (ESEM). Results showed no cell adhesion at 4 h and scarce surface colonization at 24 h. Biofilms from the environmental strain were observed at 48 h with high cellular aggregations embedded in Vibrio exopolysaccharide (VPS), while less confluence and VPS production with microcolonies of elongated cells were observed in biofilms produced by the clinical strain. At 96 h the biofilms of the environmental strain were released from the surface leaving coccoid cells and residual structures, whereas biofilms of the clinical strain formed highly organized structures such as channels, mushroom-like and pillars. This is the first study that has shown the in vitro ability of V. cholerae to colonize and form biofilms on stainless steel used in food processing.

  11. Pore Formation Process of Porous Ti3SiC2 Fabricated by Reactive Sintering

    Directory of Open Access Journals (Sweden)

    Huibin Zhang

    2017-02-01

    Full Text Available Porous Ti3SiC2 was fabricated with high purity, 99.4 vol %, through reactive sintering of titanium hydride (TiH2, silicon (Si and graphite (C elemental powders. The reaction procedures and the pore structure evolution during the sintering process were systematically studied by X-ray diffraction (XRD and scanning electron microscope (SEM. Our results show that the formation of Ti3SiC2 from TiH2/Si/C powders experienced the following steps: firstly, TiH2 decomposed into Ti; secondly, TiC and Ti5Si3 intermediate phases were generated; finally, Ti3SiC2 was produced through the reaction of TiC, Ti5Si3 and Si. The pores formed in the synthesis procedure of porous Ti3SiC2 ceramics are derived from the following aspects: interstitial pores left during the pressing procedure; pores formed because of the TiH2 decomposition; pores formed through the reactions between Ti and Si and Ti and C powders; and the pores produced accompanying the final phase synthesized during the high temperature sintering process.

  12. Hydrothermally processed 1D hydroxyapatite: Mechanism of formation and biocompatibility studies.

    Science.gov (United States)

    Stojanović, Zoran S; Ignjatović, Nenad; Wu, Victoria; Žunič, Vojka; Veselinović, Ljiljana; Škapin, Srečo; Miljković, Miroslav; Uskoković, Vuk; Uskoković, Dragan

    2016-11-01

    Recent developments in bone tissue engineering have led to an increased interest in one-dimensional (1D) hydroxyapatite (HA) nano- and micro-structures such as wires, ribbons and tubes. They have been proposed for use as cell substrates, reinforcing phases in composites and carriers for biologically active substances. Here we demonstrate the synthesis of 1D HA structures using an optimized, urea-assisted, high-yield hydrothermal batch process. The one-pot process, yielding HA structures composed of bundles of ribbons and wires, was typified by the simultaneous occurrence of a multitude of intermediate reactions, failing to meet the uniformity criteria over particle morphology and size. To overcome these issues, the preparation procedure was divided to two stages: dicalcium phosphate platelets synthesized in the first step were used as a precursor for the synthesis of 1D HA in the second stage. Despite the elongated particle morphologies, both the precursor and the final product exhibited excellent biocompatibility and caused no reduction of viability when tested against osteoblastic MC3T3-E1 cells in 2D culture up to the concentration of 2.6mg/cm(2). X-ray powder diffraction combined with a range of electron microscopies and laser diffraction analyses was used to elucidate the formation mechanism and the microstructure of the final particles. The two-step synthesis involved a more direct transformation of DCP to 1D HA with the average diameter of 37nm and the aspect ratio exceeding 100:1. The comparison of crystalline domain sizes along different crystallographic directions showed no signs of significant anisotropy, while indicating that individual nanowires are ordered in bundles in the b crystallographic direction of the P63/m space group of HA. Intermediate processes, e.g., dehydration of dicalcium phosphate, are critical for the formation of 1D HA alongside other key aspects of this phase transformation, it must be investigated in more detail in the continuous

  13. Low-Frequency Noise Characterization of Ultra-shallow Gate N-channel Junction Field Effect Transistors

    NARCIS (Netherlands)

    Piccolo, G.; Sarubbi, F.; Vandamme, L.J.K.; Macucci, M.; Scholtes, T.L.M.; Nanver, L.K.

    2007-01-01

    A recently developed technique for ultra shallow pn junction formation has been applied for the fabrication of ring-gate n-channel junction field effect devices (JFET) devices. Several different geometries, gate formation parameters and channel doping profiles have been realized and characterized wi

  14. Carbon Disulfide (CS2) Mechanisms in Formation of Atmospheric Carbon Dioxide (CO2) Formation from Unconventional Shale Gas Extraction and Processing Operations and Global Climate Change.

    Science.gov (United States)

    Rich, Alisa L; Patel, Jay T

    2015-01-01

    Carbon disulfide (CS2) has been historically associated with the production of rayon, cellophane, and carbon tetrachloride. This study identifies multiple mechanisms by which CS2 contributes to the formation of CO2 in the atmosphere. CS2 and other associated sulfide compounds were found by this study to be present in emissions from unconventional shale gas extraction and processing (E&P) operations. The breakdown products of CS2; carbonyl sulfide (COS), carbon monoxide (CO), and sulfur dioxide (SO2) are indirect greenhouse gases (GHGs) that contribute to CO2 levels in the atmosphere. The heat-trapping nature of CO2 has been found to increase the surface temperature, resulting in regional and global climate change. The purpose of this study is to identify five mechanisms by which CS2 and the breakdown products of CS2 contribute to atmospheric concentrations of CO2. The five mechanisms of CO2 formation are as follows: Chemical Interaction of CS2 and hydrogen sulfide (H2S) present in natural gas at high temperatures, resulting in CO2 formation;Combustion of CS2 in the presence of oxygen producing SO2 and CO2;Photolysis of CS2 leading to the formation of COS, CO, and SO2, which are indirect contributors to CO2 formation;One-step hydrolysis of CS2, producing reactive intermediates and ultimately forming H2S and CO2;Two-step hydrolysis of CS2 forming the reactive COS intermediate that reacts with an additional water molecule, ultimately forming H2S and CO2. CS2 and COS additionally are implicated in the formation of SO2 in the stratosphere and/or troposphere. SO2 is an indirect contributor to CO2 formation and is implicated in global climate change.

  15. Metallic Junction Thermoelectric Device Simulations

    Science.gov (United States)

    Duzik, Adam J.; Choi, Sang H.

    2017-01-01

    Thermoelectric junctions made of semiconductors have existed in radioisotope thermoelectric generators (RTG) for deep space missions, but are currently being adapted for terrestrial energy harvesting. Unfortunately, these devices are inefficient, operating at only 7% efficiency. This low efficiency has driven efforts to make high-figure-of-merit thermoelectric devices, which require a high electrical conductivity but a low thermal conductivity, a combination that is difficult to achieve. Lowered thermal conductivity has increased efficiency, but at the cost of power output. An alternative setup is to use metallic junctions rather than semiconductors as thermoelectric devices. Metals have orders of magnitude more electrons and electronic conductivities higher than semiconductors, but thermal conductivity is higher as well. To evaluate the viability of metallic junction thermoelectrics, a two dimensional heat transfer MATLAB simulation was constructed to calculate efficiency and power output. High Seebeck coefficient alloys, Chromel (90%Ni-10%Cr) and Constantan (55%Cu-45%Ni), produced efficiencies of around 20-30%. Parameters such as the number of layers of junctions, lateral junction density, and junction sizes for both series- and parallel-connected junctions were explored.

  16. Digital interpolators for polar format processing. [of synthetic aperture radar images

    Science.gov (United States)

    Adams, John W.; Hudson, Ralph E.; Bayma, Robert W.; Nelson, Jeffrey E.

    1989-01-01

    The polar format approach to SAR image formation requires data to be interpolated from a warped grid onto a Cartesian lattice. In general, this requires that data be interpolated between varying sampling rates. In this paper, frequency-domain optimality criteria for polar format interpolators are defined and justified, and an approach to designing the corresponding digital filters is described.

  17. Formation of shallow front emitters for solar cells by rapid thermal processing

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Hans B.; Svensson, Bengt G.; Monakhov, Edouard [Department of Physics/Center for Materials Science and Nanotechnology, University of Oslo, Sem Saelands vei 24, 0316 Oslo (Norway)

    2012-10-15

    In this work we report on formation of shallow front emitters by phosphorus in-diffusion during rapid thermal processing (RTP). Both Filmtronics P509 diffusant and concentrated phosphoric acid were deposited on 1 {Omega}cm p-type mono crystalline silicon samples. Diffused shallow emitters were realized by annealing at 900 C and 950 C in the range of 10 - 40 s using an Annealsys AS-Micro furnace. The chemical concentration versus depth profiles of phosphorus were measured by secondary ion mass spectrometry (SIMS) and the sheet resistance was measured by four-point probing. It is found that emitters with depths in the range 100 - 275 nm and the maximum doping concentrations in the range 2 x 10{sup 20} - 1 x 10{sup 21} cm{sup -3} can be formed after RTP. By varying the RTP-conditions, a sheet resistance of 314 - 40 {Omega}/sq for diffusant-treated samples and of 175 - 40 {Omega}/sq for phosphoric acid treated samples are obtained. The P509 diffusant and concentrated phosphoric acid gave similar emitter profiles. High solubility of phosphorus in silicon at elevated temperatures ensured a low sheet resistance even for short annealing times. It is shown that phosphorus in-diffusion during RTP is a viable method in formation of shallow front emitters for solar cells. In particular, the highest phosphorus peak concentration and the shallowest diffusion profile were achieved by in-diffusion from dehydrated phosphoric acid (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. DEVELOPMENT OF PSYCHOLOGICAL SAFETY OF PEDAGOGICAL COLLEGE STUDENT IN THE PROCESS OF PROFESSIONAL COMPETENCE FORMATION

    Directory of Open Access Journals (Sweden)

    Marina Aleksandrovna Kechina

    2013-11-01

    Full Text Available This article is devoted to studying of the interrelation between psychological safety and professional competence of pedagogical institutions students. The author points out the didactic unit elements of psychological disciplines which mastering forms the notions of the factors and ways of preventing or overcoming their effects. The article enlarges upon the certain sectional branches of psychological science (social and educational ones by means of which the differentiation of “risk” factors of psychological safety deprivation of the students is achieved, it also illustrates the mechanism of mastering-in these factors in the study of the course of “Psychology”. This work is performed by means of active application of humanitarian, psychological and educational technologies, interactive educational methods (i.e., social-and-psychological training, brainstorming, project method, group discussion method, case method in HEIs (Higher Eduction Institutions. The author reveals the importance of determination the psychological “risk” factors of psychological safety deprivation regarding the formation of professional competence of a pedagogical college student.Objective: To determine the “risk” factors of psychological safety deprivation of a Pedagogical college student in the process of formation of professional competence.Methods of the work performance: analysis of psychological and educational literature on the subject of the present study, a comparative analysis of learning didactic unit elements and identifying the “risk” factors of psychological safety deprivation.The work methodology: scientific research works of I.A. Bayeva, N.M. Borytko, and Y.V. Vardanyan.DOI: http://dx.doi.org/10.12731/2218-7405-2013-8-42

  19. High-speed carrier-depletion silicon Mach-Zehnder optical modulators with lateral PN junctions

    Directory of Open Access Journals (Sweden)

    Graham Trevor Reed

    2014-12-01

    Full Text Available This paper presents new experimental data from a lateral PN junction silicon Mach-Zehnder optical modulator. Efficiencies in the 1.4V.cm to 1.9V.cm range are demonstrated for drive voltages between 0V and 6V. High speed operation up to 52Gbit/s is also presented. The performance of the device which has its PN junction positioned in the centre of the waveguide is then compared to previously reported data from a lateral PN junction device with the junction self-aligned to the edge of the waveguide rib. An improvement in modulation efficiency is demonstrated when the junction is positioned in the centre of the waveguide. Finally we propose schemes for achieving high modulation efficiency whilst retaining self-aligned formation of the PN junction.

  20. Molecular dynamics simulation of the formation of sp3 hybridized bonds in hydrogenated diamondlike carbon deposition processes.

    Science.gov (United States)

    Murakami, Yasuo; Horiguchi, Seishi; Hamaguchi, Satoshi

    2010-04-01

    The formation process of sp3 hybridized carbon networks (i.e., diamondlike structures) in hydrogenated diamondlike carbon (DLC) films has been studied with the use of molecular-dynamics simulations. The processes simulated in this study are injections of hydrocarbon (CH3 and CH) beams into amorphous carbon (a-C) substrates. It has been shown that diamondlike sp3 structures are formed predominantly at a subsurface level when the beam energy is relatively high, as in the "subplantation" process for hydrogen-free DLC deposition. However, for hydrogenated DLC deposition, the presence of abundant hydrogen at subsurface levels, together with thermal spikes caused by energetic ion injections, substantially enhances the formation of carbon-to-carbon sp3 bonds. Therefore, the sp3 bond formation process for hydrogenated DLC films essentially differs from that for hydrogen-free DLC films.

  1. Linking varve-formation processes to climate and lake conditions at Tiefer See (NE Germany)

    Science.gov (United States)

    Dräger, Nadine; Kienel, Ulrike; Plessen, Birgit; Ott, Florian; Brademann, Brian; Pinkerneil, Sylvia; Brauer, Achim

    2017-04-01

    Annually laminated (varved) lake sediments represent unique archives in continental areas providing both, precise chronologies and seasonally resolving proxy data. Monitoring of physical, chemical and biological processes influencing lake sediment formation are a suitable approach for detailed proxy understanding of varved sediment records. Lake Tiefer See (NE Germany) indicates deposition of varved sediments today as well as millennia ago (Dräger et al., 2016; Kienel et al., 2013). Therefore, the lake provides the possibility to trace current seasonal layer formation in the lake and to pair these data to climate and lake conditions (Kienel et al., 2016). Lake Tiefer See was formed during the last glaciation and is part of the Klocksin Lake Chain, a subglacial channel system that crosses the Pomeranian terminal moraine. The lake is a mesotrophic hard water lake with a maximum depth of 63 m and a surface area of 0.75 km2. During four consecutive years (2012-2015) the particulate matter deposition was trapped at bi-weekly to monthly resolution at three different water depths (5, 12 and 50 m). The sediment trap material was analysed for sediment flux and organic matter and calcite content. In addition, we monitored limnological parameters (e.g. temperature, pH, conductivity, oxygen content) as well as the meteorological conditions (e.g. temperature, wind speed and direction, precipitation) with a monitoring and climate station installed on the lake. These data describe strength and duration of lake mixing and lake stagnation phases. Our results show distinct seasonal peaks in sediment formation, which correspond to the spring and summer productivity phases comprising of diatom blooms and calcite precipitation. This observation is in line with microfacies results from surface sediment cores. The content of biogenic calcite content decreases in the trapped material with increasing water depth indicating dissolution processes. However, the strength of calcite

  2. Low Cost Solar Array Project cell and module formation research area. Process research of non-CZ silicon material. Final report, November 26, 1980-September 30, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R.B.

    1983-01-01

    The primary objective of the work reported was to investigate high-risk, high-payoff research areas associated with the Westinghouse process for producing photovoltaic modules using non-Czochralski sheet material. These tasks were addressed: technical feasibility study of forming front and back junctions using liquid dopant techniques, liquid diffusion mask feasibility study, application studies of antireflective material using a meniscus coater, ion implantation compatibility/feasibility study, and cost analysis. (LEW)

  3. Single-molecule detection of dihydroazulene photo-thermal reaction using break junction technique

    Science.gov (United States)

    Huang, Cancan; Jevric, Martyn; Borges, Anders; Olsen, Stine T.; Hamill, Joseph M.; Zheng, Jue-Ting; Yang, Yang; Rudnev, Alexander; Baghernejad, Masoud; Broekmann, Peter; Petersen, Anne Ugleholdt; Wandlowski, Thomas; Mikkelsen, Kurt V.; Solomon, Gemma C.; Brøndsted Nielsen, Mogens; Hong, Wenjing

    2017-05-01

    Charge transport by tunnelling is one of the most ubiquitous elementary processes in nature. Small structural changes in a molecular junction can lead to significant difference in the single-molecule electronic properties, offering a tremendous opportunity to examine a reaction on the single-molecule scale by monitoring the conductance changes. Here, we explore the potential of the single-molecule break junction technique in the detection of photo-thermal reaction processes of a photochromic dihydroazulene/vinylheptafulvene system. Statistical analysis of the break junction experiments provides a quantitative approach for probing the reaction kinetics and reversibility, including the occurrence of isomerization during the reaction. The product ratios observed when switching the system in the junction does not follow those observed in solution studies (both experiment and theory), suggesting that the junction environment was perturbing the process significantly. This study opens the possibility of using nano-structured environments like molecular junctions to tailor product ratios in chemical reactions.

  4. Formation of Oxidized Organic Aerosol (OOA) through Fog Processing in the Po Valley

    Science.gov (United States)

    Gilardoni, S.; Paglione, M.; Rinaldi, M.; Giulianelli, L.; Massoli, P.; Hillamo, R. E.; Carbone, S.; Lanconelli, C.; Laaksonen, A. J.; Russell, L. M.; Poluzzi, V.; Fuzzi, S.; Facchini, C.

    2014-12-01

    Aqueous phase chemistry might be responsible for the formation of a significant fraction of the organic aerosol (OA) observed in the atmosphere, and could explain some of the discrepancies between OA concentration and properties predicted by models and observed in the environment. Aerosol - fog interaction and its effect on submicron aerosol properties were investigated in the Po Valley (northern Italy) during fall 2011, in the framework of the Supersite project (ARPA Emilia Romagna). Composition and physical properties of submicron aerosol were measured online by a High Resolution- Time of Flight - Aerosol Mass Spectrometer (HR-TOF-AMS), a Soot Photometer - Aerosol Mass Spectrometer (SP-AMS), and a Tandem Differential Mobility Particle Sizer (TDMPS). Organic functional group analysis was performed off-line by Hydrogen - Nuclear Magnetic Resonance (H-NMR) spectrometry and by Fourier Transform Infrared (FTIR) spectrometry. Aerosol absorption, scattering, and total extinction were measured simultaneously with a Particle Soot Absorption Photometer (PSAP), a Nephelometer, and a Cavity Attenuated Phase Shift Spectrometer particle extinction monitor (CAPS PMex), respectively. Water-soluble organic carbon in fog-water was characterized off-line by HR-TOF-AMS. Fourteen distinct fog events were observed. Fog dissipation left behind an aerosol enriched in particles larger than 400 nm, typical of fog and cloud processing, and dominated by secondary species, including ammonium nitrate, ammonium sulfate and oxidized OA (OOA). Source apportionment of OA allowed us to identify OOA as the difference between total OA and primary OA (hydrocarbon like OA and biomass burning OA). The formation of OOA through fog processing is proved by the correlation of OOA concentration with hydroxyl methyl sulfonate signal and by the similarity of OOA spectra with organic mass spectra obtained by re-aerosolization of fog water samples. The oxygen to carbon ratio and the hydrogen to carbon ratio of

  5. “Failures of the State”: Factors of Formation and Mechanisms of Influence on Economic Processes

    Directory of Open Access Journals (Sweden)

    Gontar Nikolay Vladimirovich

    2014-11-01

    Full Text Available The article is devoted to the problem of genesis and influence on real economic processes of “failures of the state”. The article designates the objective functions inherent in the state the realization of which can increase the efficiency of economic interactions reducing transaction expenses. Besides, the key factors of non-optimal activity of the state as well as actual “failures of the state” are considered. The approaches to the definition of “failures of the state” are analyzed. Taking into account functional approach the author proposes the model definition allowing to separate “failures of the state” from factors and conditions of their emergence. Among the emergence factors of “failures of the state” the author analyzes in detail the key division of economy subjects to net-payers and net-recipients of the income, the fact of distribution of consequences of state regulation to the sectors which are not direct objects of regulation as well as the influence of short-term decisions for long-term prospects are designated. The author also analyzes the range of “failures of the state”, including such as formation of monopolies, tax discouraging, failures of social security, nature of “state business”, derivation of resources and workers from economy, formation of an inequality and calculational (price chaos in economy. The key consequences and volume of the economic damage formed by “failures of the state” are considered, the corresponding quantitative estimates are given. The most important vectors of optimization of activity of the state which provide minimization of “failures of the state” and the related economic damage are designated. According to the author, such vectors include the priority of market self-regulation under the condition of refusal from substitutes in the form of “approach” of public sector to market standards. The minimization of public sector activity aimed at the exclusion of

  6. Constructing higher order DNA origami arrays using DNA junctions of anti-parallel/parallel double crossovers

    Science.gov (United States)

    Ma, Zhipeng; Park, Seongsu; Yamashita, Naoki; Kawai, Kentaro; Hirai, Yoshikazu; Tsuchiya, Toshiyuki; Tabata, Osamu

    2016-06-01

    DNA origami provides a versatile method for the construction of nanostructures with defined shape, size and other properties; such nanostructures may enable a hierarchical assembly of large scale architecture for the placement of other nanomaterials with atomic precision. However, the effective use of these higher order structures as functional components depends on knowledge of their assembly behavior and mechanical properties. This paper demonstrates construction of higher order DNA origami arrays with controlled orientations based on the formation of two types of DNA junctions: anti-parallel and parallel double crossovers. A two-step assembly process, in which preformed rectangular DNA origami monomer structures themselves undergo further self-assembly to form numerically unlimited arrays, was investigated to reveal the influences of assembly parameters. AFM observations showed that when parallel double crossover DNA junctions are used, the assembly of DNA origami arrays occurs with fewer monomers than for structures formed using anti-parallel double crossovers, given the same assembly parameters, indicating that the configuration of parallel double crossovers is not energetically preferred. However, the direct measurement by AFM force-controlled mapping shows that both DNA junctions of anti-parallel and parallel double crossovers have homogeneous mechanical stability with any part of DNA origami.

  7. Dissecting contact mechanics from quantum interference in single-molecule junctions of stilbene derivatives.

    Science.gov (United States)

    Aradhya, Sriharsha V; Meisner, Jeffrey S; Krikorian, Markrete; Ahn, Seokhoon; Parameswaran, Radha; Steigerwald, Michael L; Nuckolls, Colin; Venkataraman, Latha

    2012-03-14

    Electronic factors in molecules such as quantum interference and cross-conjugation can lead to dramatic modulation and suppression of conductance in single-molecule junctions. Probing such effects at the single-molecule level requires simultaneous measurements of independent junction properties, as conductance alone cannot provide conclusive evidence of junction formation for molecules with low conductivity. Here, we compare the mechanics of the conducting para-terminated 4,4'-di(methylthio)stilbene and moderately conducting 1,2-bis(4-(methylthio)phenyl)ethane to that of insulating meta-terminated 3,3'-di(methylthio)stilbene single-molecule junctions. We simultaneously measure force and conductance across single-molecule junctions and use force signatures to obtain independent evidence of junction formation and rupture in the meta-linked cross-conjugated molecule even when no clear low-bias conductance is measured. By separately quantifying conductance and mechanics, we identify the formation of atypical 3,3'-di(methylthio)stilbene molecular junctions that are mechanically stable but electronically decoupled. While theoretical studies have envisaged many plausible systems where quantum interference might be observed, our experiments provide the first direct quantitative study of the interplay between contact mechanics and the distinctively quantum mechanical nature of electronic transport in single-molecule junctions.

  8. Microwave-Synthesized Tin Oxide Nanocrystals for Low-Temperature Solution-Processed Planar Junction Organo-Halide Perovskite Solar Cells

    KAUST Repository

    Abulikemu, Mutalifu

    2017-03-25

    Tin oxide has been demonstrate to possess outstanding optoelectronic properties such as optical transparency and high electron mobility, therefore, it was successfully utilized as electron transporting layer in various kind of solar cells. In this study, for the first time, highly dispersible SnO2 nanoparticles were synthesized by microwave-assisted non-aqueous sol-gel route in an organic medium. Ethanol dispersion of the as-prepared nanoparticles was used to cast an uniform thin layer of SnO2 without the aid of aggregating agent and at low temperatures. Organohalide perovskite solar cells were fabricated using SnO2 as electron transporting layer. Morphological and spectroscopic investigations, in addition to the good photoconversion efficiency obtained evidenced that nanoparticles synthesized by this route have optimal properties such small size and crystallinity to form a continuous film, furthermore, this method allows high reproducibility and scalability of the film deposition process.

  9. How far can we go in hydrological modelling without any knowledge of runoff formation processes?

    Science.gov (United States)

    Ayzel, Georgy

    2016-04-01

    Hydrological modelling is a challenging scientific issue for the last 50 years and tend to be it further because of the highest level of runoff formation processes complexity at the different spatio-temporal scales. Enormous number of modelling-related papers have submitted to the top-ranked journals every year, but in this publication speed race authors have pay increasing attention to the models and data they use by itself rather than underlying watershed processes. Great community effort of the free and open-source models sharing with high availability of hydrometeorological data sources led to conceptual shifting paradigm of hydrological science to the technical-oriented direction. In the third-world countries this shifting is more clear by the reason of field studies absence and obligatory requirement of practical significance of the research supported by the government funds. As a result we get a state of hydrological modelling discipline closer to the aim of high Nash-Sutcliffe efficiency (NSE) achievement rather than watershed processes understanding. Both lumped physically-based land-surface model SWAP (Soil Water - Atmosphere - Plants) and SCE-UA (Shuffled Complex Evolution method developed at The University of Arizona) technique for robust model parameters search were used for the runoff modelling of 323 MOPEX watersheds. No one special data analysis and expert knowledge-based decisions were not performed. Median value of NSE is 0.652 and 90% of watersheds have efficiency bigger than 0.5. Thus without any information of particular features of each watershed satisfactory modelling results were obtained. To prove our conclusions we build cutting-edge conceptual rainfall-runoff model based on decision trees and adaptive boosting machine learning algorithms for the one small watershed in USA. No one special data analysis or feature engineering was not performed too. Obtained results demonstrate great model prediction power both for learning and testing

  10. Boric Acid Reduces the Formation of DNA Double Strand Breaks and Accelerates Wound Healing Process.

    Science.gov (United States)

    Tepedelen, Burcu Erbaykent; Soya, Elif; Korkmaz, Mehmet

    2016-12-01

    Boron is absorbed by the digestive and respiratory system, and it was considered that it is converted to boric acid (BA), which was distributed to all tissues above 90 %. The biochemical essentiality of boron element is caused by boric acid because it affects the activity of several enzymes involved in the metabolism. DNA damage repair mechanisms and oxidative stress regulation is quite important in the transition stage from normal to cancerous cells; thus, this study was conducted to investigate the protective effect of boric acid on DNA damage and wound healing in human epithelial cell line. For this purpose, the amount of DNA damage occurred with irinotecan (CPT-11), etoposide (ETP), doxorubicin (Doxo), and H2O2 was determined by immunofluorescence through phosphorylation of H2AX((Ser139)) and pATM((Ser1981)) in the absence and presence of BA. Moreover, the effect of BA on wound healing has been investigated in epithelial cells treated with these agents. Our results demonstrated that H2AX((Ser139)) foci numbers were significantly decreased in the presence of BA while wound healing was accelerated by BA compared to that in the control and only drug-treated cells. Eventually, the results indicate that BA reduced the formation of DNA double strand breaks caused by agents as well as improving the wound healing process. Therefore, we suggest that boric acid has important therapeutical effectiveness and may be used in the treatment of inflammatory diseases where oxidative stress and wound healing process plays an important role.

  11. Effect of urea on formation of hydroxyapatite through double-step hydrothermal processing

    Energy Technology Data Exchange (ETDEWEB)

    Parthiban, S. Prakash, E-mail: prakashparthiban@gmail.com; Kim, Ill Yong; Kikuta, Koichi; Ohtsuki, Chikara

    2011-10-10

    The effect of urea on the formation of hydroxyapatite (HAp) was studied by employing the double-step hydrothermal processing of a powder mixture of beta-tricalcium phosphate ({beta}-TCP) and dicalcium phosphate dihydrate (DCPD). Co-existence of urea was found to sustain morphology of HAp crystals in the compacts under an initial concentration of 2 mol dm{sup -3} and less. Homogenous morphology of needle-like crystals was observed on the compacts carbonated owing to decomposition of urea. Carbonate ions (CO{sub 3}{sup 2-}) was found to be substituted in both the phosphate and hydroxide sites of HAp lattice. The synthesized HAp was calcium deficient, as it had a Ca/P atomic ratio of 1.62 and the phase was identified as calcium deficient hydroxyapatite (CDHA). The release of CO{sub 3}{sup 2-} ions from urea during the hydrothermal treatment determined the morphology of the CDHA in the compacts. The usage of urea in the morphological control of carbonate-substituted HAp (CHAp) employing the double-step hydrothermal method is established. Highlights: {yields} Carbonate substituted hydroxyapatite (CHAp) compacts were developed by a new method, namely double-step hydrothermal processing. {yields} CHAp compacts with uniform micromorphology were obtained by using urea as solvent. {yields} Morphology was sustained even at higher concentration of urea, which emphasized the versatility of urea. {yields} Homogenous morphology of CHAp compacts were obtained for higher concentration of urea. Pores were also formed at higher concentration on the CHAp compacts. {yields} The slow dissociation of urea under hydrothermal conditions is the reason for morphology control.

  12. Imaging of cervicothoracic junction trauma

    Directory of Open Access Journals (Sweden)

    Wongwaisayawan S

    2013-01-01

    Full Text Available Sirote Wongwaisayawan,1 Ruedeekorn Suwannanon,2 Rathachai Kaewlai11Department of Radiology, Ramathibodi Hospital and Mahidol University, Bangkok, Thailand; 2Department of Radiology, Faculty of Medicine, Prince of Songkla University, Hat Yai, ThailandAbstract: Cervicothoracic junction trauma is an important cause of morbidity and mortality in trauma patients. Imaging has played an important role in identifying injuries and guiding appropriate, timely therapy. Computed tomography is currently a method of choice for diagnosing cervicothoracic junction trauma, in which the pattern of injuries often suggests possible mechanisms and potential injuries. In this article, the authors describe and illustrate common and uncommon injuries that can occur in the cervicothoracic junction.Keywords: cervicothoracic junction, cervical spine, trauma, imaging, radiology

  13. Effect of Plasma Processing and Organosilane Modifications of Polyethylene on Aeromonas hydrophila Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Dorota Kregiel

    2014-01-01

    Full Text Available The aim of our research was to study how the modifications of polyethylene—a material commonly used in medicine and water industry—influence bacterial cell attachment and biofilm formation. The native surface was activated and modified using two-step process consisting in the activation of native surface with a H2O vapor plasma followed by its treatment with various organosilanes, namely, [3(tertbutylamine-2hydroxy propyloxypropyl] diethoxymethylsilane, 1H,1H,2H,2H-perfluorooctylmethyldimethoxysilane, dimethoxydimethylsilane, and isobutylmethyldimethoxysilane. The effect of polyethylene modification after chemical treatment was analyzed using surface tension measurement. The adhesive properties of Aeromonas hydrophila LOCK0968 were studied in water with a low concentration of organic compounds, using luminometric and microscopic methods, and the viability of the adhered bacterial cells was evaluated using the colony forming units method. After two-week incubation the chemically modified materials exhibited better antiadhesive and antibacterial characteristics in comparison to the native surface. Among the examined modifying agents, dimethoxydimethylsilane showed the best desired properties.

  14. Formation process of structure 1 and 2 gas hydrates discovered in Kukuy, Lake Baikal

    Energy Technology Data Exchange (ETDEWEB)

    Hachikubo, A.; Sakagami, H.; Minami, H.; Nunokawa, Y.; Yamashita, S.; Takahashi, N.; Shoji, H. [Kitami Inst. of Technology, Kitami (Japan); Kida, M. [Advanced Industrial Science and Technology, Toyohira-ku, Sapporo, Hokkaido (Japan); Krylov, A. [All-Russia Research Inst. for Geology and Mineral Resources of the Ocean, St. Petersburg (Russian Federation); Khlystov, O.; Zemskaya, T. [Limnological Inst., Irkutsk (Russian Federation); Manakov, A. [Nikolaev Inst. of Inorganic Chemistry, Novosibirsk (Russian Federation); Kalmychkov, G. [Vinogradov Inst. of Geochemistry, Irkutsk (Russian Federation); Poort, J. [Ghent Univ., Krijgslaan (Belgium). Renard Centre of Marine Geology

    2008-07-01

    This study investigated the formation process of different crystal structures of gas hydrates found in Kukuy K-2, Lake Baikal, Russia. Gas compositions and isotopic ratios were taken from hydrate-bound gas and from dissolved gas in sediments by a headspace gas method. Structure 1 and 2 gas hydrates were observed in the same sediment cores of a mud volcano in the Kukuy Canyon, Lake Baikal. This paper discussed the results of the observations. The structure 2 gas hydrate contained about 13-15 per cent ethane, whereas the structure 1 gas hydrate contained about 1-5 per cent ethane and was placed beneath the structure 2 gas hydrate. The paper discussed the measurement of isotopic composition of dissociation gas from both type gas hydrates and dissolved gas in pore water. The paper also reported on these results. It was concluded that the current gas dissolved in pore water was not the source of these gas hydrates of both crystal structures in Kukuy K-2 mud volcano in Lake Baikal. In addition, isotopic data also provided useful information on how the double structure gas hydrates formed. 18 refs., 4 figs.

  15. Effect of Catalyst on the Formation of Silica Coating on Nickel Substrate by Sol -Gel Processing

    Institute of Scientific and Technical Information of China (English)

    Ali Ghasemi; F.Ashrafizadeh; M.A.Golozar; Ali Ashrafi

    2004-01-01

    In this research work silica coating was produced on nickel substrates by a sol-gel process. In order to increase the rate of hydrolysis and to reduce the rate of polymerization several acid catalysts including nitric acid-hydrochloric acid,acetic acid, hydrochloric acid and nitric acid were add to silica sol. Conversely, in order to control the rate of hydrolysis and to increase the rate of polymerization, basic catalyst of ammonia and ammonia hydroxyl were introduced in to the solution.Nickel specimens of known surface roughness were chemically cleaned and prepared by dipping in the sols. In order to produce a suitable silica coating the drying and firing cycles were optimized on these substrates. The structure and uniformity of the coatings produced were examined by scanning electron microscopy. Coatings composition was determined using glow discharge optical spectroscopy and EDAX microanalysis. Experimental result showed that hydrochloric acid, acetic acid, ammonia and acetic acid - ammonia are suitable catalytic agents for silica coating formation on nickel type substrate.

  16. Case studies on the formation of chalcogenide self-assembled monolayers on surfaces and dissociative processes

    Directory of Open Access Journals (Sweden)

    Yongfeng Tong

    2016-02-01

    Full Text Available This report examines the assembly of chalcogenide organic molecules on various surfaces, focusing on cases when chemisorption is accompanied by carbon–chalcogen atom-bond scission. In the case of alkane and benzyl chalcogenides, this induces formation of a chalcogenized interface layer. This process can occur during the initial stages of adsorption and then, after passivation of the surface, molecular adsorption can proceed. The characteristics of the chalcogenized interface layer can be significantly different from the metal layer and can affect various properties such as electron conduction. For chalcogenophenes, the carbon–chalcogen atom-bond breaking can lead to opening of the ring and adsorption of an alkene chalcogenide. Such a disruption of the π-electron system affects charge transport along the chains. Awareness about these effects is of importance from the point of view of molecular electronics. We discuss some recent studies based on X-ray photoelectron spectroscopy that shed light on these aspects for a series of such organic molecules.

  17. Formation of integral fins function-surface by extrusion-ploughing process

    Institute of Scientific and Technical Information of China (English)

    CHEN Ping; TANG Yong; LIU Xiao-kang; LIU Xiao-qing

    2006-01-01

    An extrusion-ploughing process was presented to fabricate the integral fin function-surface. Cutting edge inclination angle and rake angle can be calculated from the tool's geometry relationship. The description of fins' geometry characters was standardized. The experiments show that, when the middle cutting edge's inclination angle η is less than 35-, continuous fin will come out; when η is between 35- and 55-, the fins will be saw-tooth ones, and the fins will be torn when this angle is above 55-; when the extrusion angle θ is between 60- and 150-, the fins will appear, or else, the fins will be torn into chips from the base. Forming angle and clearance angle have little effect on fin's formation. For continuous fin, its height is close to cutting depth when it is small, but it will become approximately constant as cutting depth grows; for saw-tooth fins, the width, the height, as well as the clearance will increase with the increase of cutting depth, but the increment of clearance is small; neither for continuous fin, nor for saw-tooth ones, cutting velocity has little influence on their structure parameters.

  18. Numerical and experimental investigation of central cavity formation in aluminum during forward extrusion process

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, S. H.; Sedighi, M.; Mosayebnezhad, J. [Iran Univ., Tehran (Iran, Islamic Republic of)

    2016-05-15

    In the presented paper central cavity formation during the forward extrusion of commercially pure aluminum was investigated. For this purpose finite element analysis was utilized for simulation of this defect. The experimental tests were carried out on commercially pure aluminum. A good agreement between finite element simulations and experimental tests verified the adaptability of finite element simulations with the real process conditions. Taguchi method was performed for classifying the simulations regarding to consider synergistic parameters. The parameters include reduction of area, friction coefficient and die angle. Critical thickness, the representative waste material, was presented as a new criterion for optimizing the parametric study. By utilizing the Analyze Taguchi design, critical thickness was optimized and the effect of each parameter was recognized for different levels. In addition, the best levels with the minimum waste material were gained in which friction coefficient, die angle and reduction of area were 0.2, 5 .deg. and 20%, respectively. Also the amount of waste material was forecasted by just about 2% errors without FEA by Taguchi method.

  19. Effect of plasma processing and organosilane modifications of polyethylene on Aeromonas hydrophila biofilm formation.

    Science.gov (United States)

    Kregiel, Dorota; Niedzielska, Kamila

    2014-01-01

    The aim of our research was to study how the modifications of polyethylene--a material commonly used in medicine and water industry--influence bacterial cell attachment and biofilm formation. The native surface was activated and modified using two-step process consisting in the activation of native surface with a H2O vapor plasma followed by its treatment with various organosilanes, namely, [3(tertbutylamine-2hydroxy) propyloxypropyl] diethoxymethylsilane, 1H,1H,2H,2H-perfluorooctylmethyldimethoxysilane, dimethoxydimethylsilane, and isobutylmethyldimethoxysilane. The effect of polyethylene modification after chemical treatment was analyzed using surface tension measurement. The adhesive properties of Aeromonas hydrophila LOCK0968 were studied in water with a low concentration of organic compounds, using luminometric and microscopic methods, and the viability of the adhered bacterial cells was evaluated using the colony forming units method. After two-week incubation the chemically modified materials exhibited better antiadhesive and antibacterial characteristics in comparison to the native surface. Among the examined modifying agents, dimethoxydimethylsilane showed the best desired properties.

  20. The Formation Process of Massive Close Spectroscopic Binaries: The Fission Hypothesis Revisited

    Science.gov (United States)

    Zinnecker, H.; Ostriker, J.

    2013-06-01

    The vast majority of massive Main-Sequence stars (M>20 Mo) seem to be born in close interactive binary systems (Chini et al. 2012, Sana et al. 2012). The very process by which these systems form is still a mystery and has received little attention so far. Because the binary separation is so tight (less than 1AU), break-up of a critically rotating protostar ("fission") remains an interesting possibility. However, standard current star formation theory treats fission as unlikely (cf. Tohline 2002, ARAA). We question this view and investigate minimum energy states of compressible polytropic analogs to the well-known incompressible MacLaurin spheroids. Dynamical non-axisymmetric instability at a critical ratio of rotational to gravitational energy (cf. Ostriker and Bodenheimer 1973) during the shrinkage of an accreting, rapidly rotating, bloated, massive protostar AFTER ACCRETION DECLINES may provide the conditions for break-up into a close binary system. Time dependent hydro-dynamical simulations are required to either confirm or reject this hypothesis.