WorldWideScience

Sample records for additional blocking layer

  1. Morphology, microstructure, and hardness of titanium (Ti-6Al-4V) blocks deposited by wire-feed additive layer manufacturing (ALM)

    International Nuclear Information System (INIS)

    Brandl, Erhard; Schoberth, Achim; Leyens, Christoph

    2012-01-01

    Highlights: ► The microstructure and hardness of deposited Ti-6Al-4V blocks are investigated. ► Hardness is influenced by post heat treatment rather than by process parameters. ► Microstructure within the prior β-grains varies to some extent from grain to grain. ► A 600 °C/4 h treatment significantly increased the average hardness. - Abstract: Additive layer manufacturing offers a potential for time and cost savings, especially for aerospace components made from costly titanium alloys. In this paper, the morphology, microstructure, chemical composition, and hardness of additive manufactured Ti-6Al-4V blocks are investigated and discussed. Blocks (7 beads wide, 7 layers high) were deposited using Ti-6Al-4V wire and a Nd:YAG laser. Two different sets of parameters are used and three different post heat treatment conditions (as-built, 600 °C/4 h, 1200 °C/2 h) are investigated. The experiments reveal elementary properties of additive manufactured Ti-6Al-4V material in correlation to process parameters and heat treatments, which are discussed comprehensively.

  2. Morphology, microstructure, and hardness of titanium (Ti-6Al-4V) blocks deposited by wire-feed additive layer manufacturing (ALM)

    Energy Technology Data Exchange (ETDEWEB)

    Brandl, Erhard, E-mail: erhard.brandl@eads.net [EADS Innovation Works, Metallic Technologies and Surface Engineering, D-81663 Munich (Germany); Schoberth, Achim, E-mail: achim.schoberth@eads.net [EADS Innovation Works, Metallic Technologies and Surface Engineering, D-81663 Munich (Germany); Leyens, Christoph, E-mail: christoph.leyens@tu-dresden.de [Technical University of Dresden, Institute of Materials Science, Chair of Materials Technology, Berndt-Bau, Helmholtzstr. 7, D-01062 Dresden (Germany)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer The microstructure and hardness of deposited Ti-6Al-4V blocks are investigated. Black-Right-Pointing-Pointer Hardness is influenced by post heat treatment rather than by process parameters. Black-Right-Pointing-Pointer Microstructure within the prior {beta}-grains varies to some extent from grain to grain. Black-Right-Pointing-Pointer A 600 Degree-Sign C/4 h treatment significantly increased the average hardness. - Abstract: Additive layer manufacturing offers a potential for time and cost savings, especially for aerospace components made from costly titanium alloys. In this paper, the morphology, microstructure, chemical composition, and hardness of additive manufactured Ti-6Al-4V blocks are investigated and discussed. Blocks (7 beads wide, 7 layers high) were deposited using Ti-6Al-4V wire and a Nd:YAG laser. Two different sets of parameters are used and three different post heat treatment conditions (as-built, 600 Degree-Sign C/4 h, 1200 Degree-Sign C/2 h) are investigated. The experiments reveal elementary properties of additive manufactured Ti-6Al-4V material in correlation to process parameters and heat treatments, which are discussed comprehensively.

  3. Block copolymer/homopolymer dual-layer hollow fiber membranes

    KAUST Repository

    Hilke, Roland; Neelakanda, Pradeep; Behzad, Ali Reza; Nunes, Suzana Pereira; Peinemann, Klaus-Viktor

    2014-01-01

    We manufactured the first time block copolymer dual-layer hollow fiber membranes and dual layer flat sheet membranes manufactured by double solution casting and phase inversion in water. The support porous layer was based on polystyrene

  4. Organic photovoltaic cell incorporating electron conducting exciton blocking layers

    Science.gov (United States)

    Forrest, Stephen R.; Lassiter, Brian E.

    2014-08-26

    The present disclosure relates to photosensitive optoelectronic devices including a compound blocking layer located between an acceptor material and a cathode, the compound blocking layer including: at least one electron conducting material, and at least one wide-gap electron conducting exciton blocking layer. For example, 3,4,9,10 perylenetetracarboxylic bisbenzimidazole (PTCBI) and 1,4,5,8-napthalene-tetracarboxylic-dianhydride (NTCDA) function as electron conducting and exciton blocking layers when interposed between the acceptor layer and cathode. Both materials serve as efficient electron conductors, leading to a fill factor as high as 0.70. By using an NTCDA/PTCBI compound blocking layer structure increased power conversion efficiency is achieved, compared to an analogous device using a conventional blocking layers shown to conduct electrons via damage-induced midgap states.

  5. Block copolymer/homopolymer dual-layer hollow fiber membranes

    KAUST Repository

    Hilke, Roland

    2014-12-01

    We manufactured the first time block copolymer dual-layer hollow fiber membranes and dual layer flat sheet membranes manufactured by double solution casting and phase inversion in water. The support porous layer was based on polystyrene and the selective layer with isopores was formed by micelle assembly of polystyrene-. b-poly-4-vinyl pyridine. The dual layers had an excellent interfacial adhesion and pore interconnectivity. The dual membranes showed pH response behavior like single layer block copolymer membranes with a low flux for pH values less than 3, a fast increase between pH4 and pH6 and a constant high flux level for pH values above 7. The dry/wet spinning process was optimized to produce dual layer hollow fiber membranes with polystyrene internal support layer and a shell block copolymer selective layer.

  6. Fouling layer characterization and pore-blocking mechanisms in an ...

    African Journals Online (AJOL)

    Fouling layer characterization and pore-blocking mechanisms in an UF membrane externally coupled to a UASB reactor. ... Regarding pore-blocking mechanisms, standard blocking was the predominant mechanism at the beginning of filtration, coexisting at the end of it with cake filtration. In the first filtration cycle (1 h), after ...

  7. Additive Manufacturing of Molds for Fabrication of Insulated Concrete Block

    Energy Technology Data Exchange (ETDEWEB)

    Love, Lonnie J. [ORNL; Lloyd, Peter D. [ORNL

    2018-02-01

    ORNL worked with concrete block manufacturer, NRG Insulated Block, to demonstrate additive manufacturing of a multi-component block mold for its line of insulated blocks. Solid models of the mold parts were constructed from existing two-dimensional drawings and the parts were fabricated on a Stratasys Fortus 900 using ULTEM 9085. Block mold parts were delivered to NRG and installed on one of their fabrication lines. While form and fit were acceptable, the molds failed to function during NRG’s testing.

  8. Clustering network layers with the strata multilayer stochastic block model.

    Science.gov (United States)

    Stanley, Natalie; Shai, Saray; Taylor, Dane; Mucha, Peter J

    2016-01-01

    Multilayer networks are a useful data structure for simultaneously capturing multiple types of relationships between a set of nodes. In such networks, each relational definition gives rise to a layer. While each layer provides its own set of information, community structure across layers can be collectively utilized to discover and quantify underlying relational patterns between nodes. To concisely extract information from a multilayer network, we propose to identify and combine sets of layers with meaningful similarities in community structure. In this paper, we describe the "strata multilayer stochastic block model" (sMLSBM), a probabilistic model for multilayer community structure. The central extension of the model is that there exist groups of layers, called "strata", which are defined such that all layers in a given stratum have community structure described by a common stochastic block model (SBM). That is, layers in a stratum exhibit similar node-to-community assignments and SBM probability parameters. Fitting the sMLSBM to a multilayer network provides a joint clustering that yields node-to-community and layer-to-stratum assignments, which cooperatively aid one another during inference. We describe an algorithm for separating layers into their appropriate strata and an inference technique for estimating the SBM parameters for each stratum. We demonstrate our method using synthetic networks and a multilayer network inferred from data collected in the Human Microbiome Project.

  9. Additive Layer Manufacturing for Launcher's Applications

    Science.gov (United States)

    Vilanova, J.; Romera, P.; Lasagni, F.; Zorrilla, A.; Perinan, A.

    2014-06-01

    In the next years the European space industry has the challenge of maintaining its competitiveness in launch vehicles (LV) production, due to the growth of competition worldwide. It has to assure its position developing new applied technologies. In this field the effort is focussed on the production of short series of customized products, like payloads, flight components or launcher parts. ALM (Additive Layer Manufacturing) could be a powerful tool that offers new competitiveness factors for this industry, comprising a set of emerging technologies that are becoming a competitor to forming, casting and machining as well as being utilised directly as a complementary alternative.Originally used for prototypes and models, now ALM becomes a very useful technology capable to fabricate functional parts for the space industrial sector. Its demands on rapid technologies are different to "earth" industries, and they aren't so easily satisfied because space is a field with different requirements depending on its application: launchers, reusable vehicles, satellites, probes, low gravity researches, manned spacecraft, or even moon and planetary exploration.This paper reports on the ALM potential applications, under ESA requirements, exploring the challenges and possibilities for its use in the launchers market, trying to answer two basic questions: the first one, whether ALM is a mature technology to be ready for its use as flight hardware; and the second one, if it can be used to reduce the product cycle, and consequently, the development, production and operational costs.

  10. Blocking layer modeling for temperature analysis of electron transfer ...

    African Journals Online (AJOL)

    In this article, we simulate thermal effects on the electron transfer rate from three quantum dots CdSe, CdS and CdTe to three metal oxides TiO2, SnO2 and ZnO2 in the presence of four blocking layers ZnS, ZnO, TiO2 and Al2O3, in a porous quantum dot sensitized solar cell (QDSSC) structure, using Marcus theory.

  11. Improvement of Concrete Paving Blocks Properties by Mineral Additions

    Directory of Open Access Journals (Sweden)

    Aqeel Hatem Chkheiwer

    2017-03-01

    Full Text Available This research presents the results of experimental work on the various properties concrete paving blocks (CPB made with concrete containing different mineral additions.in this study, three types of mineral additions;Fly Ash (FA,Metakaolin (MK and Silica Fume (SF were used. Thirteen concretes mixes were cast at a water/binder ratio of 0.45 with 0, 5, 10,15and 20% cement replaced by either Fly ash,Metakaolin or Silica Fume. Theconcrete mixes were tested for slump, compressive strength, water absorption, and abrasion resistance.Metakaolin-contained concrete showed a better workability than fly ash and silica fume concrete. As the replacement level wasincreased, the 28-days compressive strength of the CPB containing MK increased similarly to that of the silica fume-containedCPB up to 20% replacement ratio. The replacement ratio of MK and SF from 5 to 20 % reduced water absorptionof CPB from5 to 19 than that of control mix. The increase in replacement ratio of MK andSF from 5 to 20 % leads to increasing abrasion resistance from 8 to 18% that of control mix

  12. Adaptive Multi-Layered Space-Time Block Coded Systems in Wireless Environments

    KAUST Repository

    Al-Ghadhban, Samir

    2014-12-23

    © 2014, Springer Science+Business Media New York. Multi-layered space-time block coded systems (MLSTBC) strike a balance between spatial multiplexing and transmit diversity. In this paper, we analyze the block error rate performance of MLSTBC. In addition, we propose an adaptive MLSTBC schemes that are capable of accommodating the channel signal-to-noise ratio variation of wireless systems by near instantaneously adapting the uplink transmission configuration. The main results demonstrate that significant effective throughput improvements can be achieved while maintaining a certain target bit error rate.

  13. Adaptive Multi-Layered Space-Time Block Coded Systems in Wireless Environments

    KAUST Repository

    Al-Ghadhban, Samir

    2014-01-01

    © 2014, Springer Science+Business Media New York. Multi-layered space-time block coded systems (MLSTBC) strike a balance between spatial multiplexing and transmit diversity. In this paper, we analyze the block error rate performance of MLSTBC

  14. Influence of anchor block size on the thickness of adsorbed block copolymer layers

    NARCIS (Netherlands)

    Belder, G.F; ten Brinke, G.; Hadziioannou, G

    1997-01-01

    We present surface force data on three different polystyrene/poly(2-vinylpyridine) block copolymers (PS/P2VP) with a fixed size of the nonadsorbing PS block but widely varying sizes of the adsorbing P2VP block. With respect to the sizes of the two blocks, they range from moderately to highly

  15. PIV measurement of turbulent mixing layer flow with polymer additives

    International Nuclear Information System (INIS)

    Ning, T; Guo, F; Chen, B; Zhang, X

    2009-01-01

    Turbulent mixing layer flow with polymer additives was experimentally investigated by PIV in present paper. The velocity ratio between high and low speed is 4:1 and the Reynolds number for pure water case based on the velocity differences of two steams and hydraulic diameter of the channel ranges from 14667∼73333. Flow field and turbulent quantities of turbulent mixing layer with 200ppm polymer additives were measured and compared with pure water mixing layer flow. It is shown that the dynamic development of mixing layer is greatly influenced by polymer addictives. The smaller vortices are eliminated and the coherent structure is much clearer. Similar with pure water case, Reynolds stress and vorticity still concentrate in a coniform area of central part of mixing layer and the width will increase with the Reynolds number increasing. However, compared with pure water case, the coniform width of polymer additives case is larger, which means the polymer additives will lead to the diffusion of coherent structure. The peak value of vorticity in different cross section will decrease with the development of mixing layer. Compared with pure water case, the vorticity is larger at the beginning of the mixing layer but decreases faster in the case with polymer additives.

  16. Comparison of single and dual layer detector blocks for pre-clinical MRI–PET

    International Nuclear Information System (INIS)

    Thompson, Christopher; Stortz, Greg; Goertzen, Andrew; Berg, Eric; Retière, Fabrice; Kozlowski, Piotr; Ryner, Lawrence; Sossi, Vesna; Zhang, Xuezhu

    2013-01-01

    Dual or multi-layer crystal blocks have been proposed to minimise the radial blurring effect in PET scanners with small ring diameters. We measured two potential PET detector blocks' performance in a configuration which would allow 16 blocks in a ring which could be inserted in a small animal 7T MRI scanner. Two crystal sizes, 1.60×1.60 mm 2 and 1.20×1.20 mm 2 , were investigated. Single layer blocks had 10 or 12 mm deep crystals, the dual layer blocks had 4 mm deep crystals on the top layer and 6 mm deep crystals on the bottom layer. The crystals in the dual layer blocks are offset by ½ of the crystal pitch to allow for purely geometric crystal identification. Both were read out with SensL 4×4 SiPM arrays. The software identifies 64 crystals in the single layer and either 85 or 113 crystals in the dual layer array, (either 49 or 64 in the lower layers and 36 or 49 in the upper layers). All the crystals were clearly visible in the crystal identification images and their resolvability indexes (average FWHM/crystal separation) were shown to range from 0.29 for the best single layer block to 0.33 for the densest dual layer block. The best coincidence response FWHM was 0.95 mm for the densest block at the centre of the field. This degraded to 1.83 mm at a simulated radial offset of 16 mm from the centre, while the single layer crystals blurred this result to 3.4 mm. The energy resolution was 16.4±2.2% averaged over the 113 crystals of the densest block

  17. Addition of dexmedetomidine to bupivacaine in supraclavicular brachial plexus block.

    Science.gov (United States)

    Aksu, Recep; Bicer, Cihangir

    2017-06-26

    Research is ongoing to determine the lowest dose of local anesthetics in brachial plexus block that provides adequate anesthesia and postoperative analgesia and reduces complications related to local anesthetics. Patients 18-65 years of age who underwent upper limb surgery and who received ultrasound-guided supraclavicular brachial plexus block at the Erciyes University Faculty of Medicine Hospital between February 2014 and January 2015 were included in the study (n=50). Supraclavicular brachial plexus blocks were performed on Group B cases by adding 30 ml 0.33% bupivacaine and on Group BD cases by adding 15 ml 0.33% bupivacaine and 1 µg / kg dexmedetomidine. Block success was evaluated by the onset and block duration of motor and sensory block and the duration of analgesia. The block success of Group B and Group BD was 92.6% and 89.3%, respectively (P = 1.000). Onset time of sensory block, degree of sensory block, duration of sensory block, onset time of motor block, degree of motor block and duration of motor block were similar in both groups in the intergroup comparison (P > 0.05). Duration of analgesia and the operative conditions of groups were similar (P > 0.05). In the implementation of ultrasound-guided supraclavicular brachial plexus block, block success, sensory and motor block and analgesia duration were similar for patients anaesthetized with 30 ml of bupivacaine in comparison with dexmedetomidine+bupivacaine (when the bupivacaine dose was reduced by 50% by the addition of the adjuvant).

  18. Copper based superconductors by the combination of blocking and mediating layers

    International Nuclear Information System (INIS)

    Shimizu, K.; Nobumasa, H.; Kawai, T.

    1992-01-01

    Copper based high temperature superconductors are composed of Cu-O 2 sheets in combination with thin atomic mediating layers and thick blocking layers which mediate and intercept interactions between Cu-O 2 sheets, respectively. New possible superconductors can be designed by the stacking of the Cu-O 2 sheets along with the periodic insertion of the mediating layers and different kinds of blocking layers. (orig.)

  19. Improved fill factor in inverted planar perovskite solar cells with zirconium acetate as the hole-and-ion-blocking layer.

    Science.gov (United States)

    Zhang, Xuewen; Liang, Chunjun; Sun, Mengjie; Zhang, Huimin; Ji, Chao; Guo, Zebang; Xu, Yajun; Sun, Fulin; Song, Qi; He, Zhiqun

    2018-03-14

    Planar perovskite solar cells (PSCs) have gained great interest due to their low-temperature solution preparation and simple process. In inverted planar PSCs, an additional buffer layer is usually needed on the top of the PCBM electron-transport layer (ETL) to enhance the device performance. In this work, we used a new buffer layer, zirconium acetate (Zr(Ac) 4 ). The inclusion of the Zr(Ac) 4 buffer layer leads to the increase of FF from ∼68% to ∼79% and PCE from ∼14% to ∼17% in the planar PSCs. The UPS measurement indicates that the Zr(Ac) 4 layer has a low HOMO level of -8.2 eV, indicating that the buffer layer can act as a hole-blocking layer. Surface morphology and surface chemistry investigations reveal that the elements I, MA and Pb can diffuse across the PCBM ETL, damaging the device performance. The covering Zr(Ac) 4 molecules fill in the pinholes of the PCBM layer and effectively block the ions/molecules of the perovskite from diffusion across the ETL. The resulting more robust PCBM/Zr(Ac) 4 ETL leads to weaker ionic charge accumulation and lower diode leakage current. The double role of hole-and-ion blocking of the Zr(Ac) 4 layer explains the improved FF and PCE in the PSCs.

  20. Electrochemical Characterization of TiO 2 Blocking Layers for Dye-Sensitized Solar Cells

    KAUST Repository

    Kavan, Ladislav

    2014-07-31

    Thin compact layers of TiO2 are grown by thermal oxidation of Ti, by spray pyrolysis, by electrochemical deposition, and by atomic layer deposition. These layers are used in dye-sensitized solar cells to prevent recombination of electrons from the substrate (FTO or Ti) with the hole-conducting medium at this interface. The quality of blocking is evaluated electrochemically by methylviologen, ferro/ferricyanide, and spiro-OMeTAD as the model redox probes. Two types of pinholes in the blocking layers are classified, and their effective area is quantified. Frequency-independent Mott-Schottky plots are fitted from electrochemical impedance spectroscopy. Certain films of the thicknesses of several nanometers allow distinguishing the depletion layer formation both in the TiO2 film and in the FTO substrate underneath the titania film. The excellent blocking function of thermally oxidized Ti, electrodeposited film (60 nm), and atomic-layer-deposited films (>6 nm) is documented by the relative pinhole area of less than 1%. However, the blocking behavior of electrodeposited and atomic-layer-deposited films is strongly reduced upon calcination at 500 °C. The blocking function of spray-pyrolyzed films is less good but also less sensitive to calcination. The thermally oxidized Ti is well blocking and insensitive to calcination. © 2014 American Chemical Society.

  1. Optimization of Aircraft Seat Cushion Fire Blocking Layers.

    Science.gov (United States)

    1983-03-01

    function of cost and weight, and the costs of labor involved in assembling a ccmposite seat cushion. The same classes of high char yield polymers that are...SEAT LATER DESIGN REPORT NRBBNBsg$$$$$$NN$$R$$$$$ SEAT DESIGN NUMBER: 009 LAYER NAME CODE NO. S MANUFACTURER 5 COST FACTORS . LABOR ...72621, 9096.. 7SS43. 73757. 77147. DELTA COSTS 0. 8340. 2922. 1136. 4327. ACOSOS in Iho..aS Of dollars. COST SUIRNY REPORT Re ....... VONR3 MORFA

  2. The dependence of the modulation transfer function on the blocking layer thickness in amorphous selenium x-ray detectors

    International Nuclear Information System (INIS)

    Hunter, David M.; Belev, Gueorgi; DeCrescenzo, Giovanni; Kasap, Safa O.; Mainprize, James G.; Rowlands, J. A.; Smith, Charles; Tuemer, Tuemay; Verpakhovski, Vladimir; Yin Shi; Yaffe, Martin J.

    2007-01-01

    Blocking layers are used to reduce leakage current in amorphous selenium detectors. The effect of the thickness of the blocking layer on the presampling modulation transfer function (MTF) and on dark current was experimentally determined in prototype single-line CCD-based amorphous selenium (a-Se) x-ray detectors. The sampling pitch of the detectors evaluated was 25 μm and the blocking layer thicknesses varied from 1 to 51 μm. The blocking layers resided on the signal collection electrodes which, in this configuration, were used to collect electrons. The combined thickness of the blocking layer and a-Se bulk in each detector was ∼200 μm. As expected, the dark current increased monotonically as the thickness of the blocking layer was decreased. It was found that if the blocking layer thickness was small compared to the sampling pitch, it caused a negligible reduction in MTF. However, the MTF was observed to decrease dramatically at spatial frequencies near the Nyquist frequency as the blocking layer thickness approached or exceeded the electrode sampling pitch. This observed reduction in MTF is shown to be consistent with predictions of an electrostatic model wherein the image charge from the a-Se is trapped at a characteristic depth within the blocking layer, generally near the interface between the blocking layer and the a-Se bulk

  3. Semiconducting Polymer Photodetectors with Electron and Hole Blocking Layers: High Detectivity in the Near-Infrared

    Directory of Open Access Journals (Sweden)

    Xiong Gong

    2010-07-01

    Full Text Available Sensing from the ultraviolet-visible to the infrared is critical for a variety of industrial and scientific applications. Photodetectors with broad spectral response, from 300 nm to 1,100 nm, were fabricated using a narrow-band gap semiconducting polymer blended with a fullerene derivative. By using both an electron-blocking layer and a hole-blocking layer, the polymer photodetectors, operating at room temperature, exhibited calculated detectivities greater than 1013 cm Hz1/2/W over entire spectral range with linear dynamic range approximately 130 dB. The performance is comparable to or even better than Si photodetectors.

  4. Structural Color for Additive Manufacturing: 3D-Printed Photonic Crystals from Block Copolymers.

    Science.gov (United States)

    Boyle, Bret M; French, Tracy A; Pearson, Ryan M; McCarthy, Blaine G; Miyake, Garret M

    2017-03-28

    The incorporation of structural color into 3D printed parts is reported, presenting an alternative to the need for pigments or dyes for colored parts produced through additive manufacturing. Thermoplastic build materials composed of dendritic block copolymers were designed, synthesized, and used to additively manufacture plastic parts exhibiting structural color. The reflection properties of the photonic crystals arise from the periodic nanostructure formed through block copolymer self-assembly during polymer processing. The wavelength of reflected light could be tuned across the visible spectrum by synthetically controlling the block copolymer molecular weight and manufacture parts that reflected violet, green, or orange light with the capacity to serve as selective optical filters and light guides.

  5. TiO2 nanofiber solid-state dye sensitized solar cells with thin TiO2 hole blocking layer prepared by atomic layer deposition

    International Nuclear Information System (INIS)

    Li, Jinwei; Chen, Xi; Xu, Weihe; Nam, Chang-Yong; Shi, Yong

    2013-01-01

    We incorporated a thin but structurally dense TiO 2 layer prepared by atomic layer deposition (ALD) as an efficient hole blocking layer in the TiO 2 nanofiber based solid-state dye sensitized solar cell (ss-DSSC). The nanofiber ss-DSSCs having ALD TiO 2 layers displayed increased open circuit voltage, short circuit current density, and power conversion efficiency compared to control devices with blocking layers prepared by spin-coating liquid TiO 2 precursor. We attribute the improved photovoltaic device performance to the structural integrity of ALD-coated TiO 2 layer and consequently enhanced hole blocking effect that results in reduced dark leakage current and increased charge carrier lifetime. - Highlights: • TiO 2 blocking locking layer prepared by atomic layer deposition (ALD) method. • ALD-coated TiO 2 layer enhanced hole blocking effect. • ALD blocking layer improved the voltage, current and efficiency. • ALD blocking layer reduced dark leakage current and increased electron lifetime

  6. TiO{sub 2} nanofiber solid-state dye sensitized solar cells with thin TiO{sub 2} hole blocking layer prepared by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jinwei; Chen, Xi; Xu, Weihe [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States); Nam, Chang-Yong, E-mail: cynam@bnl.gov [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973 (United States); Shi, Yong, E-mail: Yong.Shi@stevens.edu [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)

    2013-06-01

    We incorporated a thin but structurally dense TiO{sub 2} layer prepared by atomic layer deposition (ALD) as an efficient hole blocking layer in the TiO{sub 2} nanofiber based solid-state dye sensitized solar cell (ss-DSSC). The nanofiber ss-DSSCs having ALD TiO{sub 2} layers displayed increased open circuit voltage, short circuit current density, and power conversion efficiency compared to control devices with blocking layers prepared by spin-coating liquid TiO{sub 2} precursor. We attribute the improved photovoltaic device performance to the structural integrity of ALD-coated TiO{sub 2} layer and consequently enhanced hole blocking effect that results in reduced dark leakage current and increased charge carrier lifetime. - Highlights: • TiO{sub 2} blocking locking layer prepared by atomic layer deposition (ALD) method. • ALD-coated TiO{sub 2} layer enhanced hole blocking effect. • ALD blocking layer improved the voltage, current and efficiency. • ALD blocking layer reduced dark leakage current and increased electron lifetime.

  7. Addition of clonidine to bupivacaine in transversus abdominis plane block prolongs postoperative analgesia after cesarean section

    Directory of Open Access Journals (Sweden)

    Ranju Singh

    2016-01-01

    Conclusion: Addition of clonidine 1 μg/kg to 20 ml bupivacaine 0.25% in TAP block bilaterally for cesarean section significantly increases the duration of postoperative analgesia, decreases postoperative analgesic requirement, and increases maternal comfort compared to 20 ml of bupivacaine 0.25% alone.

  8. Ion blocking and channeling studies of heteroepitaxial GaN layers

    International Nuclear Information System (INIS)

    Flagmeyer, R.; Ehrlich, C.; Geist, V.; Otto, G.

    1978-01-01

    Ion channeling and blocking in backscattering measurements were used for the characterization of thin epitaxial GaN layers, which have varied lattice imperfections involved by different growth conditions. In particular, the following characteristics were examined: (1) the thickness and the uniformity of the layers, (2) the depth dependence of the crystalline imperfection, (3) the dislocation density, (4) the spread in the orientation distribution of tilted crystallites, and (5) some other types of imperfections, such as stacking faults, double positioning, twins and bending of the layer

  9. Efficiency of solution-processed multilayer polymer light-emitting diodes using charge blocking layers

    Science.gov (United States)

    Kasparek, Christian; Rörich, Irina; Blom, Paul W. M.; Wetzelaer, Gert-Jan A. H.

    2018-01-01

    By blending semiconducting polymers with the cross-linkable matrix ethoxylated-(4)-bisphenol-a-dimethacrylate (SR540), an insoluble layer is acquired after UV-illumination. Following this approach, a trilayer polymer light-emitting diode (PLED) consisting of a blend of poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] (poly-TPD) and SR540 as an electron-blocking layer, Super Yellow-Poly(p-phenylene vinylene) (SY-PPV) blended with SR540 as an emissive layer, and poly(9,9-di-n-octylfluorenyl-2,7-diyl) as a hole-blocking layer is fabricated from solution. The trilayer PLED shows a 23% increase in efficiency at low voltage as compared to a single layer SY-PPV PLED. However, at higher voltage, the advantage in current efficiency gradually decreases. A combined experimental and modelling study shows that the increased efficiency is not only due to the elimination of exciton quenching at the electrodes but also due to suppressed nonradiative trap-assisted recombination due to carrier confinement. At high voltages, holes can overcome the hole-blocking barrier, which explains the efficiency roll-off.

  10. Improved charge trapping flash device with Al2O3/HfSiO stack as blocking layer

    International Nuclear Information System (INIS)

    Zheng Zhi-Wei; Huo Zong-Liang; Zhu Chen-Xin; Xu Zhong-Guang; Liu Jing; Liu Ming

    2011-01-01

    In this paper, we investigate an Al 2 O 3 /HfSiO stack as the blocking layer of a metal—oxide—nitride—oxide—silicon-type (MONOS) memory capacitor. Compared with a memory capacitor with a single HfSiO layer as the blocking layer or an Al 2 O 3 /HfO 2 stack as the blocking layer, the sample with the Al 2 O 3 /HfSiO stack as the blocking layer shows high program/erase (P/E) speed and good data retention characteristics. These improved performances can be explained by energy band engineering. The experimental results demonstrate that the memory device with an Al 2 O 3 /HfSiO stack as the blocking layer has great potential for further high-performance nonvolatile memory applications. (interdisciplinary physics and related areas of science and technology)

  11. Effect of porcelain polishing addition of waste in properties blocks ceramic

    International Nuclear Information System (INIS)

    Santana, G.L.; Barbosa Neto, M.C.; Campos, L.F.; Macedo, D.A; Dutra, R.P.S.

    2016-01-01

    This work has as objective the study of the technological properties of ceramic blocks with addition of residue porcelain polishing. The test samples are produced with clay base, where the waste is introduced in concentrations of 10% and 20% by mass, to evaluate its influence on the properties of the ceramic block. All these materials were characterized by determining their chemical composition (XRF) and X-ray diffraction Sintering was performed at temperatures of 850 ° C, 950 ° C and 1100 ° C with a heating rate of 2 ° C / me and 60 minutes of landing. After this, there was obtained the technological properties of the samples such as: Loss on fire, the burning linear shrinkage, water absorption, porosity and density, as well as, mechanical strength properties through the flexural strength test. The results show that the addition of waste influenced both the technological properties, the mechanical properties evaluated in this study. (author)

  12. Growth of monolithic full-color GaN-based LED with intermediate carrier blocking layers

    Energy Technology Data Exchange (ETDEWEB)

    El-Ghoroury, Hussein S.; Yeh, Milton; Chen, J. C., E-mail: jc.chen@ostendo.com; Li, X.; Chuang, Chih-Li [EPI Lab, Ostendo Technologies, Inc., 679 Brea Canyon Rd, Walnut, CA 91789 (United States)

    2016-07-15

    Specially designed intermediate carrier blocking layers (ICBLs) in multi-active regions of III-nitride LEDs were shown to be effective in controlling the carrier injection distribution across the active regions. In principle, the majority of carriers, both holes and electrons, can be guided into targeted quantum wells and recombine to generate light of specific wavelengths at controlled current-densities. Accordingly we proposed and demonstrated a novel monolithic InGaN-based LED to achieve three primary colors of light from one device at selected current densities. This LED structure, which has three different sets of quantum wells separated with ICBLs for three primary red-green-blue (RGB) colors, was grown by metal-organic chemical vapor deposition (MOCVD). Results show that this LED can emit light ranging from 460 to 650 nm to cover the entire visible spectrum. The emission wavelength starts at 650 nm and then decreases to 460 nm or lower as the injection current increases. In addition to three primary colors, many other colors can be obtained by color mixing techniques. To the best of our knowledge, this is the first demonstration of monolithic full-color LED grown by a simple growth technique without using re-growth process.

  13. Growth of monolithic full-color GaN-based LED with intermediate carrier blocking layers

    International Nuclear Information System (INIS)

    El-Ghoroury, Hussein S.; Yeh, Milton; Chen, J. C.; Li, X.; Chuang, Chih-Li

    2016-01-01

    Specially designed intermediate carrier blocking layers (ICBLs) in multi-active regions of III-nitride LEDs were shown to be effective in controlling the carrier injection distribution across the active regions. In principle, the majority of carriers, both holes and electrons, can be guided into targeted quantum wells and recombine to generate light of specific wavelengths at controlled current-densities. Accordingly we proposed and demonstrated a novel monolithic InGaN-based LED to achieve three primary colors of light from one device at selected current densities. This LED structure, which has three different sets of quantum wells separated with ICBLs for three primary red-green-blue (RGB) colors, was grown by metal-organic chemical vapor deposition (MOCVD). Results show that this LED can emit light ranging from 460 to 650 nm to cover the entire visible spectrum. The emission wavelength starts at 650 nm and then decreases to 460 nm or lower as the injection current increases. In addition to three primary colors, many other colors can be obtained by color mixing techniques. To the best of our knowledge, this is the first demonstration of monolithic full-color LED grown by a simple growth technique without using re-growth process.

  14. A Thieno[3,2-b][1]benzothiophene Isoindigo Building Block for Additive- and Annealing-Free High-Performance Polymer Solar Cells

    KAUST Repository

    Yue, Wan; Ashraf, Raja Shahid; Nielsen, Christian B.; Collado-Fregoso, Elisa; Niazi, Muhammad Rizwan; Yousaf, Syeda Amber; Kirkus, Mindaugas; Chen, Hung-Yang; Amassian, Aram; Durrant, James R.; McCulloch, Iain

    2015-01-01

    A novel photoactive polymer with two different molecular weights is reported, based on a new building block: thieno[3,2-b][1]benzothiophene isoindigo. Due to the improved crystallinity, optimal blend morphology, and higher charge mobility, solar-cell devices of the high-molecular-weight polymer exhibit a superior performance, affording efficiencies of 9.1% without the need for additives, annealing, or additional extraction layers during device fabrication.

  15. A Thieno[3,2-b][1]benzothiophene Isoindigo Building Block for Additive- and Annealing-Free High-Performance Polymer Solar Cells

    KAUST Repository

    Yue, Wan

    2015-08-20

    A novel photoactive polymer with two different molecular weights is reported, based on a new building block: thieno[3,2-b][1]benzothiophene isoindigo. Due to the improved crystallinity, optimal blend morphology, and higher charge mobility, solar-cell devices of the high-molecular-weight polymer exhibit a superior performance, affording efficiencies of 9.1% without the need for additives, annealing, or additional extraction layers during device fabrication.

  16. A Randomized Controlled Trial Examining the Effect of the Addition of the Mandibular Block to Cervical Plexus Block for Carotid Endarterectomy.

    Science.gov (United States)

    Kavrut Ozturk, Nilgun; Kavakli, Ali Sait; Sagdic, Kadir; Inanoglu, Kerem; Umot Ayoglu, Raif

    2018-04-01

    Although the cervical plexus block generally provides adequate analgesia for carotid endarterectomy, pain caused by metal retractors on the inferior surface of the mandible is not prevented by the cervical block. Different pain relief methods can be performed for patients who experience discomfort in these areas. In this study, the authors evaluated the effect of mandibular block in addition to cervical plexus block on pain scores in carotid endarterectomy. A prospective, randomized, controlled trial. Training and research hospital. Patients who underwent a carotid endarterectomy. Patients scheduled for carotid endarterectomy under cervical plexus block were randomized into 2 groups: group 1 (those who did not receive a mandibular block) and group 2 (those who received a mandibular block). The main purpose of the study was to evaluate the mandibular block in addition to cervical plexus block in terms of intraoperative pain scores. Intraoperative visual analog scale scores were significantly higher in group 1 (p = 0.001). The amounts of supplemental 1% lidocaine and intraoperative intravenous analgesic used were significantly higher in group 1 (p = 0.001 and p = 0.035, respectively). Patient satisfaction scores were significantly lower in group 1 (p = 0.044). The amount of postoperative analgesic used, time to first analgesic requirement, postoperative visual analog scale scores, and surgeon satisfaction scores were similar in both groups. There was no significant difference between the groups with respect to complications. No major neurologic deficits or perioperative mortality were observed. Mandibular block in addition to cervical plexus block provides better intraoperative pain control and greater patient satisfaction than cervical plexus block alone. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Effect of substrate composition on atomic layer deposition using self-assembled monolayers as blocking layers

    International Nuclear Information System (INIS)

    Zhang, Wenyu; Engstrom, James R.

    2016-01-01

    The authors have examined the effect of two molecules that form self-assembled monolayers (SAMs) on the subsequent growth of TaN x by atomic layer deposition (ALD) on two substrate surfaces, SiO 2 and Cu. The SAMs that the authors have investigated include two vapor phase deposited, fluorinated alkyl silanes: Cl 3 Si(CH 2 ) 2 (CF 2 ) 5 CF 3 (FOTS) and (C 2 H 5 O) 3 Si(CH 2 ) 2 (CF 2 ) 7 CF 3 (HDFTEOS). Both the SAMs themselves and the TaN x thin films, grown using Ta[N(CH 3 ) 2 ] 5 and NH 3 , were analyzed ex situ using contact angle, spectroscopic ellipsometry, x-ray photoelectron spectroscopy (XPS), and low energy ion-scattering spectroscopy (LEISS). First, the authors find that both SAMs on SiO 2 are nominally stable at T s  ∼ 300 °C, the substrate temperature used for ALD, while on Cu, the authors find that HDFTEOS thermally desorbs, while FOTS is retained on the surface. The latter result reflects the difference in the head groups of these two molecules. The authors find that both SAMs strongly attenuate the ALD growth of TaN x on SiO 2 , by about a factor of 10, while on Cu, the SAMs have no effect on ALD growth. Results from LEISS and XPS are decisive in determining the nature of the mechanism of growth of TaN x on all surfaces. Growth on SiO 2 is 2D and approximately layer-by-layer, while on the surfaces terminated by the SAMs, it nucleates at defect sites, is islanded, and is 3D. In the latter case, our results support growth of the TaN x thin film over the SAM, with a considerable delay in formation of a continuous thin film. Growth on Cu, with or without the SAMs, is also 3D and islanded, and there is also a delay in the formation of a continuous thin film as compared to growth on SiO 2 . These results highlight the power of coupling measurements from both LEISS and XPS in examinations of ultrathin films formed by ALD

  18. Self-organization processes in polysiloxane block copolymers, initiated by modifying fullerene additives

    Science.gov (United States)

    Voznyakovskii, A. P.; Kudoyarova, V. Kh.; Kudoyarov, M. F.; Patrova, M. Ya.

    2017-08-01

    Thin films of a polyblock polysiloxane copolymer and their composites with a modifying fullerene C60 additive are studied by atomic force microscopy, Rutherford backscattering, and neutron scattering. The data of atomic force microscopy show that with the addition of fullerene to the bulk of the polymer matrix, the initial relief of the film surface is leveled more, the larger the additive. This trend is associated with the processes of self-organization of rigid block sequences, which are initiated by the field effect of the surface of fullerene aggregates and lead to an increase in the number of their domains in the bulk of the polymer matrix. The data of Rutherford backscattering and neutron scattering indicate the formation of additional structures with a radius of 60 nm only in films containing fullerene, and their fraction increases with increasing fullerene concentration. A comparative analysis of the data of these methods has shown that such structures are, namely, the domains of a rigid block and are not formed by individual fullerene aggregates. The interrelation of the structure and mechanical properties of polymer films is considered.

  19. Neutral wetting brush layers for block copolymer thin films using homopolymer blends processed at high temperatures

    International Nuclear Information System (INIS)

    Ceresoli, M; Palermo, M; Ferrarese Lupi, F; Seguini, G; Perego, M; Zuccheri, G; Phadatare, S D; Antonioli, D; Gianotti, V; Sparnacci, K; Laus, M

    2015-01-01

    Binary homopolymer blends of two hydroxyl-terminated polystyrene (PS-OH) and polymethylmethacrylate (PMMA-OH) homopolymers (Mn ∼ 16000 g mol"−"1) were grafted on SiO_2 substrates by high-temperature (T > 150 °C), short-time (t < 600 s) thermal treatments. The resulting brush layer was tested to screen preferential interactions of the SiO_2 substrate with the different symmetric and asymmetric PS-b-PMMA block copolymers deposited on top of the grafted molecules. By properly adjusting the blend composition and the processing parameters, an efficient surface neutralization path was identified, enabling the formation, in the block copolymer film, of homogeneous textures of lamellae or cylinders perpendicularly oriented with respect to the substrate. A critical interplay between the phase segregation of the homopolymer blends and their grafting process on the SiO_2 was observed. In fact, the polar SiO_2 is preferential for the PMMA-rich phase that forms a homogeneous layer on the substrate, while the PS-rich phase is located at the polymer-air interface. During the thermal treatment, phase segregation and grafting proceed simultaneously. Complete wetting of the PS rich phase on the PMMA rich phase leads to the formation of a PS/PMMA bilayer. In this case, the progressive diffusion of PS chains toward the polymer-SiO_2 interface during the thermal treatment allows tuning of the brush layer composition. (paper)

  20. Autonomously Self-Adhesive Hydrogels as Building Blocks for Additive Manufacturing.

    Science.gov (United States)

    Deng, Xudong; Attalla, Rana; Sadowski, Lukas P; Chen, Mengsu; Majcher, Michael J; Urosev, Ivan; Yin, Da-Chuan; Selvaganapathy, P Ravi; Filipe, Carlos D M; Hoare, Todd

    2018-01-08

    We report a simple method of preparing autonomous and rapid self-adhesive hydrogels and their use as building blocks for additive manufacturing of functional tissue scaffolds. Dynamic cross-linking between 2-aminophenylboronic acid-functionalized hyaluronic acid and poly(vinyl alcohol) yields hydrogels that recover their mechanical integrity within 1 min after cutting or shear under both neutral and acidic pH conditions. Incorporation of this hydrogel in an interpenetrating calcium-alginate network results in an interfacially stiffer but still rapidly self-adhesive hydrogel that can be assembled into hollow perfusion channels by simple contact additive manufacturing within minutes. Such channels withstand fluid perfusion while retaining their dimensions and support endothelial cell growth and proliferation, providing a simple and modular route to produce customized cell scaffolds.

  1. A dual layer DOI GSO block detector for a small animal PET

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi

    2009-01-01

    For a high resolution animal positron emission tomography (PET), depth-of-interaction (DOI) is a useful method to improve both spatial resolution and sensitivity. Gd 2 SiO 5 (GSO) with different amounts of Ce can provide different decay times and is ideal for DOI detector using pulse shape analysis. Dual layer DOI GSO block detectors using different amounts of Ce were developed for a new animal PET. The DOI GSO block detector employed two types of GSOs; one with 1.5 mol% Ce concentration (decay time: 35 ns) and the other with 0.5 mol% (decay time: 60 ns). These two GSO types were optically coupled in the DOI direction. The sizes of single GSOs were 1.9 mmx1.9 mmx6 mm and 1.9 mmx1.9 mmx9 mm, for 1.5 and 0.5 mol%, respectively. These GSO were arranged by 11x37 matrix and optically coupled to three position sensitive photomultiplier tubes (PSPMTs), where the PSPMTs used were Hamamatsu R8520U-00-C12. Different lengths of reflectors were used between crystals to increase the useful field-of-view (FOV) of the PSPMT and to avoid the dead areas between PSPMTs. With this configuration, almost all islands in a 2-D position histogram corresponding to GSO cells could be separated. The width of the GSO block was 22 mm in the transaxial direction and 74 mm in axial direction with no gaps. Also, two types of GSO of different decay time could be separated using dual integration method for pulse shape analysis. These results indicate that developed block detectors might be useful for a high resolution and high sensitivity animal PET with dual layer DOI detection capability, with no gaps in transaxial or axial directions.

  2. Atomic layer deposition assisted pattern transfer technology for ultra-thin block copolymer films

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wenhui; Luo, Jun; Meng, Lingkuan; Li, Junjie; Xiang, Jinjuan; Li, Junfeng; Wang, Wenwu; Chen, Dapeng; Ye, Tianchun; Zhao, Chao

    2016-08-31

    As an emerging developing technique for next-generation lithography, directed self-assembly (DSA) of block copolymer (BCP) has attracted numerous attention and has been a potential alternative to supplement the intrinsic limitations of conventional photolithography. In this work, the self-assembling properties of a lamellar diblock copolymer poly(styrene-b-methylmethacrylate) (PS-b-PMMA, 22k-b-22k, L{sub 0} = 25 nm) on Si substrate and an atomic layer deposition (ALD)-assisted pattern transfer technology for the application of DSA beyond 16/14 nm complementary metal oxide semiconductor (CMOS) technology nodes, were investigated. Firstly, two key processing parameters of DSA, i.e. annealing temperatures and durations of BCP films, were optimized to achieve low defect density and high productivity. After phase separation of BCP films, self-assembling patterns of low defect density should be transferred to the substrate. However, due to the nano-scale thickness and the weak resistance of BCP films to dry etching, it is nearly impossible to transfer the BCP patterns directly to the substrate. Therefore, an ALD-based technology was explored in this work, in which deposited Al{sub 2}O{sub 3} selectively reacts with PMMA blocks thus hardening the PMMA patterns. After removing PS blocks by plasma etching, hardened PMMA patterns were left and transferred to underneath SiO{sub 2} hard mask layer. Using this patterned hard mask, nanowire array of 25 nm pitch were realized on Si substrate. From this work, a high-throughput DSA baseline flow and related ALD-assisted pattern transfer technique were developed and proved to have good capability with the mainstream CMOS technology. - Highlights: • Optimization on self-assembly process for high productivity and low defectivity • Enhancement of etching ratio and resistance by atomic layer deposition (ALD) • A hard mask was used for pattern quality improvement and contamination control.

  3. Natural Rubber Modification For Upper Layer Of Rubberized Asphalt Paving Block AS Shock Absorber

    OpenAIRE

    Nasruddin, Nasruddin

    2017-01-01

    The research of rubber compounding modification for upper layer of rubberized asphalt paving block as shock absorber using natural rubber, styrene butadiene rubber (SBR) as synthetic rubber, fly ash as filler and also vegetable oil as plasticizer has been conducted. The research design was varying the filler Si-69, fly ash and palm oil. The five formulas A, B, C, D, and E designed by varying the amount of Si-69 (48.5; 50.75; 53.00; 55.25; and 57.50) phr; coal fly ash (4.75, 7.00, 9.25, 11.50 ...

  4. Boundary layers of aqueous surfactant and block copolymer solutions against hydrophobic and hydrophilic solid surfaces

    International Nuclear Information System (INIS)

    Steitz, Roland; Schemmel, Sebastian; Shi Hongwei; Findenegg, Gerhard H

    2005-01-01

    The boundary layer of aqueous surfactants and amphiphilic triblock copolymers against flat solid surfaces of different degrees of hydrophobicity was investigated by neutron reflectometry (NR), grazing incidence small angle neutron scattering (GISANS) and atomic force microscopy (AFM). Solid substrates of different hydrophobicities were prepared by appropriate surface treatment or by coating silicon wafers with polymer films of different chemical natures. For substrates coated with thin films (20-30 nm) of deuterated poly(styrene) (water contact angle θ w ∼ 90), neutron reflectivity measurements on the polymer/water interface revealed a water depleted liquid boundary layer of 2-3 nm thickness and a density about 90% of the bulk water density. No pronounced depletion layer was found at the interface of water against a less hydrophobic polyelectrolyte coating (θ w ∼ 63). It is believed that the observed depletion layer at the hydrophobic polymer/water interface is a precursor of the nanobubbles which have been observed by AFM at this interface. Decoration of the polymer coatings by adsorbed layers of nonionic C m E n surfactants improves their wettability by the aqueous phase at surfactant concentrations well below the critical micellar concentration (CMC) of the surfactant. Here, GISANS experiments conducted on the system SiO 2 /C 8 E 4 /D 2 O reveal that there is no preferred lateral organization of the C 8 E 4 adsorption layers. For amphiphilic triblock copolymers (PEO-PPO-PEO) it is found that under equilibrium conditions they form solvent-swollen brushes both at the air/water and the solid/water interface. In the latter case, the brushes transform to uniform, dense layers after extensive rinsing with water and subsequent solvent evaporation. The primary adsorption layers maintain properties of the precursor brushes. In particular, their thickness scales with the number of ethylene oxide units (EO) of the block copolymer. In the case of dip-coating without

  5. Influence of additional heat exchanger block on directional solidification system for growing multi-crystalline silicon ingot - A simulation investigation

    Science.gov (United States)

    Nagarajan, S. G.; Srinivasan, M.; Aravinth, K.; Ramasamy, P.

    2018-04-01

    Transient simulation has been carried out for analyzing the heat transfer properties of Directional Solidification (DS) furnace. The simulation results revealed that the additional heat exchanger block under the bottom insulation on the DS furnace has enhanced the control of solidification of the silicon melt. Controlled Heat extraction rate during the solidification of silicon melt is requisite for growing good quality ingots which has been achieved by the additional heat exchanger block. As an additional heat exchanger block, the water circulating plate has been placed under the bottom insulation. The heat flux analysis of DS system and the temperature distribution studies of grown ingot confirm that the established additional heat exchanger block on the DS system gives additional benefit to the mc-Si ingot.

  6. Determination of residual stresses in objects at their additive manufacturing by layer-by-layer photopolymerization method

    Science.gov (United States)

    Bychkov, P. S.; Chentsov, A. V.; Kozintsev, V. M.; Popov, A. L.

    2018-04-01

    A calculation-experimental technique is developed for identification of the shrinkage stresses generated in objects after their additive manufacturing by layer-by-layer photopolymerization. The technique is based on the analysis of shrinkage deformations at bending occurring in a series of samples in the form of plates-stripes with identical sizes, but with different time of polymerization which is predetermined during their production on the 3D printer.

  7. Analysis of Nanoparticle Additive Couple Stress Fluids in Three-layered Journal Bearing

    International Nuclear Information System (INIS)

    Rao, T V V L N; Sufian, S; Mohamed, N M

    2013-01-01

    The present theoretical study investigates the load capacity and friction coefficient in a three-layered journal bearing lubricated with nanoparticle additive couple stress fluids. The couple stresses effects are analyzed based on Stokes micro-continuum theory. The nondimensional pressure and shear stress expressions are derived using modified Reynolds equation. The nondimensional load capacity increases and the coefficient of friction decreases using nanoparticle additive lubricants with couple stress effects. The three-layered journal bearing performance characteristics are improved with increase in both (i) surface adsorbent fluid film layer thickness and (ii) dynamic viscosity ratio of surface to core layer.

  8. Effect of the addition of rocuronium to 2% lignocaine in peribulbar block for cataract surgery.

    Science.gov (United States)

    Patil, Vishalakshi; Farooqy, Allauddin; Chaluvadi, Balaraju Thayappa; Rajashekhar, Vinayak; Malshetty, Ashwini

    2017-01-01

    Peribulbar anesthesia is associated with delayed orbital akinesia compared with retrobulbar anesthesia. To test the hypothesis that rocuronium added to a mixture of local anesthetics (LAs) could improve speed of onset of akinesia in peribulbar block (PB), we designed this study. This study examined the effects of adding rocuronium 5 mg to 2% lignocaine with adrenaline to note orbital and eyelid akinesia in patients undergoing cataract surgery. In a prospective, randomized, double-blind study, 100 patients were equally randomized to receive a mixture of 0.5 ml normal saline, 6 ml lidocaine 2% with adrenaline and hyaluronidase 50 IU/ml (Group I), a mixture of rocuronium 0.5 ml (5 mg), 6 ml lidocaine 2% with adrenaline and hyaluronidase 50 IU/ml (Group II). Orbital akinesia was assessed on a 0-8 score (0 = no movement, 8 = normal) at 2 min intervals for 10 min. Time to adequate anesthesia was also recorded. Results are presented as mean ± standard deviation. Rocuronium group demonstrated significantly better akinesia scores than control group at 2 min intervals post-PB (significant P value obtained). No significant complications were recorded. Rocuronium added to a mixture of LA improved the quality of akinesia in PB and reduced the need for supplementary injections. The addition of rocuronium 5 mg to a mixture of lidocaine 2% with adrenaline and hyaluronidase 50 IU/ml shortened the onset time of peribulbar anesthesia in patients undergoing cataract surgery without causing adverse effects.

  9. A layers-overlapping strategy for robotic wire and arc additive manufacturing of multi-layer multi-bead components with homogeneous layers

    NARCIS (Netherlands)

    Li, Y.; Han, Qinglin; Zhang, Guangjun; Horvath, I.

    2018-01-01

    Robotic wire and arc additive manufacturing (WAAM) systems are required to provide predictable and efficient operations to fabricate solid metallic parts with high morphological fidelity and geometric accuracy. Since the metallic parts are fabricated based on a layer-by-layer principle, the

  10. A Study on Field Emission Characteristics of Planar Graphene Layers Obtained from a Highly Oriented Pyrolyzed Graphite Block.

    KAUST Repository

    Lee, Seok Woo; Lee, Seung S; Yang, Eui-Hyeok

    2009-01-01

    This paper describes an experimental study on field emission characteristics of individual graphene layers for vacuum nanoelectronics. Graphene layers were prepared by mechanical exfoliation from a highly oriented pyrolyzed graphite block and placed on an insulating substrate, with the resulting field emission behavior investigated using a nanomanipulator operating inside a scanning electron microscope. A pair of tungsten tips controlled by the nanomanipulator enabled electric connection with the graphene layers without postfabrication. The maximum emitted current from the graphene layers was 170 nA and the turn-on voltage was 12.1 V.

  11. A Study on Field Emission Characteristics of Planar Graphene Layers Obtained from a Highly Oriented Pyrolyzed Graphite Block.

    KAUST Repository

    Lee, Seok Woo

    2009-07-12

    This paper describes an experimental study on field emission characteristics of individual graphene layers for vacuum nanoelectronics. Graphene layers were prepared by mechanical exfoliation from a highly oriented pyrolyzed graphite block and placed on an insulating substrate, with the resulting field emission behavior investigated using a nanomanipulator operating inside a scanning electron microscope. A pair of tungsten tips controlled by the nanomanipulator enabled electric connection with the graphene layers without postfabrication. The maximum emitted current from the graphene layers was 170 nA and the turn-on voltage was 12.1 V.

  12. Charge carriers bulk recombination instead of electroplex emission after their tunneling through hole-blocking layer in OLEDs

    Science.gov (United States)

    Yang, S. Y.; Liu, D.; Jiang, Y.; Teng, F.; Xu, Z.; Hou, Y.; Xu, X. R.

    2006-08-01

    Charge carriers bulk recombination instead of forming electroplex after their tunneling through a hole-blocking layer, i.e. 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), in organic electroluminescence (EL) device ITO/poly-(N-vinyl-carbazole)(PVK)/BCP/tris(8-hydroxyquinoline) aluminum (Alq3)/Al is reported. By changing the thickness of BCP layer, one can find that high electric fields enhance the tunneling process of holes accumulated at the PVK/BCP interface into BCP layer instead of forming “electroplex emission” as reported earlier in literatures. Our experimental data show that charge carriers bulk recombination takes place in both PVK layer and BCP layer, and even in Alq3 layer when BCP layer is thin enough. Further, it is suggested that PVK is the origin of the emission shoulder at 595 nm in the EL spectra of trilayer device ITO/PVK/BCP/Alq3/Al.

  13. Does the Addition of Tramadol and Ketamine to Ropivacaine Prolong the Axillary Brachial Plexus Block?

    Directory of Open Access Journals (Sweden)

    Ahmet Can Senel

    2014-01-01

    Full Text Available Background and Objectives. A prospective, randomized, controlled, double-blind clinical trial to assess the effect of tramadol and ketamine, 50 mg, added to ropivacaine in brachial plexus anesthesia. Methods. Thirty-six ASA physical statuses I and II patients, between 18 and 60 years of age, scheduled for forearm and hand surgery under axillary brachial plexus block, were allocated to 3 groups. Group R received 0.375% ropivacaine in 40 mL, group RT received 0.375% ropivacaine in 40 mL with 50 mg tramadol, and group RK received 0.375% ropivacaine in 40 mL with 50 mg ketamine for axillary brachial plexus block. The onset times and the duration of sensory and motor blocks, duration of analgesia, hemodynamic parameters, and adverse events (nausea, vomiting, and feeling uncomfortable were recorded. Results. The onset time of sensorial block was the fastest in ropivacaine + tramadol group. Duration of sensorial and motor block was the shortest in the ropivacaine + tramadol group. Duration of analgesia was significantly longer in ropivacaine + tramadol group. Conclusion. We conclude that when added to brachial plexus analgesia at a dose of 50 mg, tramadol extends the onset and duration time of the block and improves the quality of postoperative analgesia without any side effects.

  14. A guide to the synthesis of block copolymers using reversible-addition fragmentation chain transfer (RAFT) polymerization.

    Science.gov (United States)

    Keddie, Daniel J

    2014-01-21

    The discovery of reversible-deactivation radical polymerization (RDRP) has provided an avenue for the synthesis of a vast array of polymers with a rich variety of functionality and architecture. The preparation of block copolymers has received significant focus in this burgeoning research field, due to their diverse properties and potential in a wide range of research environments. This tutorial review will address the important concepts behind the design and synthesis of block copolymers using reversible addition-fragmentation chain transfer (RAFT) polymerization. RAFT polymerization is arguably the most versatile of the RDRP methods due to its compatibility with a wide range of functional monomers and reaction media along with its relative ease of use. With an ever increasing array of researchers that possess a variety of backgrounds now turning to RDRP, and RAFT in particular, to prepare their required polymeric materials, it is pertinent to discuss the important points which enable the preparation of high purity functional block copolymers with targeted molar mass and narrow molar mass distribution using RAFT polymerization. The key principles of appropriate RAFT agent selection, the order of monomer addition in block synthesis and potential issues with maintaining high end-group fidelity are addressed. Additionally, techniques which allow block copolymers to be accessed using a combination of RAFT polymerization and complementary techniques are touched upon.

  15. Enhancing Carrier Injection Using Graded Superlattice Electron Blocking Layer for UVB Light-Emitting Diodes

    KAUST Repository

    Janjua, Bilal

    2014-12-01

    We have studied enhanced carrier injection by having an electron blocking layer (EBL) based on a graded superlattice (SL) design. Here, we examine, using a selfconsistent 6 × 6 k.p method, the energy band alignment diagrams under equilibrium and forward bias conditions while also considering carrier distribution and recombination rates (Shockley-Read-Hall, Auger, and radiative recombination rates). The graded SL is based on AlxGa1-xN (larger bandgap) Al0:5Ga0:5N (smaller bandgap) SL, where x is changed from 0.8 to 0.56 in steps of 0.06. Graded SL was found to be effective in reducing electron leakage and enhancing hole injection into the active region. Due to our band engineering scheme for EBL, four orders-of-magnitude enhancement were observed in the direct recombination rate, as compared with the conventional bulk EBL consisting of Al0:8Ga0:2N. An increase in the spatial overlap of carrier wavefunction was obtained due to polarization-induced band bending in the active region. An efficient single quantum-well ultraviolet-B light-emitting diode was designed, which emits at 280 nm. This is the effective wavelength for water disinfection application, among others.

  16. Application of poly (p-phenylene oxide) as blocking layer to reduce self-discharge in supercapacitors

    Science.gov (United States)

    Tevi, Tete; Yaghoubi, Houman; Wang, Jing; Takshi, Arash

    2013-11-01

    Supercapacitors are electrochemical energy storage devices with high power density. However, application of supercapacitors is limited mainly due to their high leakage current. In this work, application of an ultra-thin layer of electrodeposited poly (p-phenylene oxide) (PPO) has been investigated as a blocking layer to reduce the leakage current. The polymer was first deposited on a glassy carbon electrode. The morphology of the film was studied by atomic force microscopy (AFM), and the film thickness was estimated to be ˜1.5 nm by using the electrochemical impedance spectroscopy (EIS) technique. The same deposition method was applied to coat the surface of the activated carbon electrodes of a supercapacitor with PPO. The specific capacitance, the leakage current, and the series resistance were measured in two devices with and without the blocking layer. The results demonstrate that the application of the PPO layer reduced the leakage current by ˜78%. However, the specific capacitance was decreased by ˜56%, when the blocking layer was applied. Due to the lower rate of self-discharge, the suggested approach can be applied to fabricate devices with longer charge storage time.

  17. Observations and model calculations of an additional layer in the topside ionosphere above Fortaleza, Brazil

    Directory of Open Access Journals (Sweden)

    B. Jenkins

    1997-06-01

    Full Text Available Calculations using the Sheffield University plasmasphere ionosphere model have shown that under certain conditions an additional layer can form in the low latitude topside ionosphere. This layer (the F3 layer has subsequently been observed in ionograms recorded at Fortaleza in Brazil. It has not been observed in ionograms recorded at the neighbouring station São Luis. Model calculations have shown that the F3 layer is most likely to form in summer at Fortaleza due to a combination of the neutral wind and the E×B drift acting to raise the plasma. At the location of São Luis, almost on the geomagnetic equator, the neutral wind has a smaller vertical component so the F3 layer does not form.

  18. Electric Double-Layer Capacitor Fabricated with Addition of Carbon Nanotube to Polarizable Electrode

    OpenAIRE

    Yoshiyuki Show

    2012-01-01

    Electrical double-layer capacitor (EDLC) was fabricated with addition of carbon nanotube (CNT) to polarization electrodes as a conducting material. The CNT addition reduced the series resistance of the EDLC by one-twentieth, while the capacitance was not increased by the CNT addition. The low series resistance leaded to the high electrical energy stored in the EDLC. In this paper, the dependence of the series resistance, the specific capacitance, the energy, and the energy efficiencies on the...

  19. Increase of the blocking temperature of Fe–Ag granular multilayers with increasing number of the layers

    Energy Technology Data Exchange (ETDEWEB)

    Balogh, Judit [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Kaptás, Dénes, E-mail: kaptas.denes@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Kiss, László F. [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Dézsi, István [Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Nakanishi, Akio [Department of Physics, Shiga University of Medical Science, Shiga 520-2192 (Japan); Devlin, Eamonn; Vasilakaki, Marianna; Margaris, George; Trohidou, Kalliopi N. [Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Aghia Paraskevi, 15310 Athens (Greece)

    2016-03-01

    Multilayers of 0.4 nm Fe and 5 nm Ag with repetition number, n=1, 2, 5, 10 and 20 were prepared by vacuum evaporation onto Si wafer. The blocking temperature was determined by measuring the field cooled and zero field cooled magnetization curves with a SQUID magnetometer and it was found to increase by almost an order of magnitude from around 20 K for the single Fe layer sample up to around 160 K for n=20. Significant increase of the average size of the superparamagnetic Fe grains by increasing the number of the Fe layers was excluded by conversion electron Mössbauer spectroscopy measurements of the paramagnetic state. The role of the dipole–dipole interactions and their interplay with the out-of-plain magnetic anisotropy in the variation of the blocking temperature has been investigated by Monte-Carlo simulations. - Highlights: • Multilayers of [0.4 nm Fe/5 nm Ag]{sub n} (n=1,2,5,10, and 20) were grown over Si. • Large increase of the superparamagnetic blocking temperature up to n=10 is observed. • The average Fe grain size does not change in the subsequent layers. • Perpendicular anisotropy enhances the dipolar coupling and the blocking temperature.

  20. Contact problems of a rectangular block on an elastic layer of finite thickness. Part I: The thin layer

    NARCIS (Netherlands)

    Alblas, J.B.; Kuipers, M.

    1969-01-01

    We consider a layer of finite thickness loaded in plane strain by a stamp with a straight horizontal base, which is smooth and rigid. The stamp is pressed vertically into the layer and is slightly rotated by an external moment load subsequently. Two cases are considered successively: the lower side

  1. Contact problems of a rectangular block on an elastic layer of finite thickness: Part II: The thick layer

    NARCIS (Netherlands)

    Alblas, J.B.; Kuipers, M.

    1970-01-01

    We consider a layer of finite thickness loaded in plane strain by a stamp with a straight horizontal base, which is smooth and rigid. The stamp is pressed vertically into the layer and is slightly rotated by an external moment load subsequently. Two cases are considered successively: the lower side

  2. Significant performance enhancement of inverted organic light-emitting diodes by using ZnIx as a hole-blocking layer

    Science.gov (United States)

    Cheng, Chuan-Hui; Zhang, Bi-Long; Sun, Chao; Li, Ruo-Xuan; Wang, Yuan; Tian, Wen-Ming; Zhao, Chun-Yi; Jin, Sheng-Ye; Liu, Wei-Feng; Luo, Ying-Min; Du, Guo-Tong; Cong, Shu-Lin

    2017-06-01

    A highly efficient inverted organic light emitting diode using 1.0 nm-thick ZnIx as a hole-blocking layer is developed. We fabricate devices with the configuration ITO/ZnIx (1.0 nm)/Alq3 (50 nm)/NPB (50 nm)/MoO3 (6.0 nm)/Al (100 nm). The deposition of a ZnIx layer increases the maximum luminance by two orders of magnitude from 13.4 to 3566.1 cd/m2. In addition, the maximum current efficiency and power efficiency are increased by three orders of magnitude, and the turn-on voltage to reach 1 cd/m2 decreases from 13 to 8 V. The results suggest that the electron injection efficiency is not improved by introducing a ZnIx layer. Instead, the improved device performance originates from the strong hole-blocking ability of ZnIx. This work indicates that layered materials may lead to novel applications in optoelectronic devices.

  3. PIV measurement of turbulent bubbly mixing layer flow with polymer additives

    International Nuclear Information System (INIS)

    Ning, T; Guo, F; Chen, B; Zhang, X

    2009-01-01

    Based on experimental investigation of single-phase turbulent mixing layer flow with polymer additives, bubbly mixing layer was experimentally investigated by PIV. The velocity ratio between high and low speed is 4:1 and the Reynolds number based on the velocity difference of two steams and hydraulic diameter of the channel ranges is 73333. Gas bubbles with about 0.5% gas fraction were injected into pure water mixing layer with/without polymer additives from three different parts at the end of the splitter plate. The comparison between single phase and bubbly mixing layer shows clearly that the dynamic development of mixing layer is great influenced by the bubble injection. Similar with single phase, the Reynolds stress and vorticity still concentrate in a coniform area of central mixing flow field part and the width will increase with increasing the Reynolds number. Mean Reynolds stress will decrease with bubble injection in high Reynolds numbers and the decreasing of Reynolds stress with polymer additives is much more than pure water case.

  4. Microstructure engineering of Portland cement pastes and mortars through addition of ultrafine layer silicates

    DEFF Research Database (Denmark)

    Lindgreen, Holger; Geiker, Mette; Krøyer, Hanne

    2008-01-01

    Pozzolanic submicron-sized silica fume and the non-pozzolanic micron- and nano-sized layer silicates (clay minerals) kaolinite, smectite and palygorskite have been used as additives in Portland cement pastes and mortars. These layer silicates have different particle shape (needles and plates......), surface charge, and size (micron and nano). The structure of the resulting cement pastes and mortars has been investigated by atomic force microscopy (AFM), helium porosimetry, nitrogen adsorption (specific surface area and porosity), low-temperature calorimetry (LTC) and thermal analysis. The main result...... is that the cement paste structure and porosity can be engineered by addition of selected layer silicates having specific particle shapes and surface properties (e.g., charge and specific surface area). This seems to be due to the growth of calcium-silicate hydrates (C-S-H) on the clay particle surfaces...

  5. Electric Double-Layer Capacitor Fabricated with Addition of Carbon Nanotube to Polarizable Electrode

    International Nuclear Information System (INIS)

    Yoshiyuki, S.

    2012-01-01

    Electrical double-layer capacitor (EDLC) was fabricated with addition of carbon nano tube (CNT) to polarization electrodes as a conducting material. The CNT addition reduced the series resistance of the EDLC by one-twentieth, while the capacitance was not increased by the CNT addition. The low series resistance leaded to the high electrical energy stored in the EDLC. In this paper, the dependence of the series resistance, the specific capacitance, the energy, and the energy efficiencies on the CNT addition is discussed

  6. Electric Double-Layer Capacitor Fabricated with Addition of Carbon Nanotube to Polarizable Electrode

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Show

    2012-01-01

    Full Text Available Electrical double-layer capacitor (EDLC was fabricated with addition of carbon nanotube (CNT to polarization electrodes as a conducting material. The CNT addition reduced the series resistance of the EDLC by one-twentieth, while the capacitance was not increased by the CNT addition. The low series resistance leaded to the high electrical energy stored in the EDLC. In this paper, the dependence of the series resistance, the specific capacitance, the energy, and the energy efficiencies on the CNT addition is discussed.

  7. Sensing and controlling resin-layer thickness in additive manufacturing processes

    NARCIS (Netherlands)

    Kozhevnikov, A.

    2017-01-01

    This AM-TKI project in collaboration with TNO focusses on the sensing and control of resin-layer thickness in AM applications. Industrial Additive Manufacturing is considered to be a potential breakthrough production technology for many applications. A specific AM implementation is VAT photo

  8. Role of the electron blocking layer in the graded-index separate confinement heterostructure nitride laser diodes

    Science.gov (United States)

    Bojarska, Agata; Goss, Jakub; Stanczyk, Szymon; Makarowa, Irina; Schiavon, Dario; Czernecki, Robert; Suski, Tadeusz; Perlin, Piotr

    2018-04-01

    In this work, we investigate the role of the electron blocking layer (EBL) in laser diodes based on a graded index separate confinement heterostructure. We compare two sets of devices with very different EBL aluminum composition (3% and 12%) and design (graded and superlattice). The results of electro-optical characterization of these laser diodes reveal surprisingly modest role of electron blocking layer composition in determination of the threshold current and the differential efficiency values. However, EBL structure influences the operating voltage, which is decreased for devices with lower EBL and superlattice EBL. We observe also the differences in the thermal stability of devices - characteristic temperature is lower for lasers with 3% Al in EBL.

  9. HOLE-BLOCKING LAYERS FOR SILICON/ORGANIC HETEROJUNCTIONS: A NEW CLASS OF HIGH-EFFICIENCY LOW-COST PV

    Energy Technology Data Exchange (ETDEWEB)

    Sturm, James [Princeton Univ., NJ (United States)

    2017-12-04

    This project is the first investigation of the use of thin titanium dioxide layers on silicon as a hole-blocking / electron-transparent selective contact to silicon. The work was motivated by the goal of a high-efficiency low-cost silicon-based solar cells that could be processed entirely at low temperature (300 Degree Celsius) or less, without requiring plasma-processing.

  10. Self-assembly of block copolymer micelles: synthesis via reversible addition-fragmentation chain transfer polymerization and aqueous solution properties.

    Science.gov (United States)

    Mya, Khine Y; Lin, Esther M J; Gudipati, Chakravarthy S; Gose, Halima B A S; He, Chaobin

    2010-07-22

    Poly(hexafluorobutyl methacrylate) (PHFBMA) homopolymer was synthesized by reversible addition-fragmentation chain transfer (RAFT)-mediated living radical polymerization in the presence of cyano-2-propyl dithiobenzoate (CPDB) RAFT agent. A block copolymer of PHFBMA-poly(propylene glycol acrylate) (PHFBMA-b-PPGA) with dangling poly(propylene glycol) (PPG) side chains was then synthesized by using CPDB-terminated PHFBMA as a macro-RAFT agent. The amphiphilic properties and self-assembly of PHFBMA-b-PPGA block copolymer in aqueous solution were investigated by dynamic and static light scattering (DLS and SLS) studies, in combination with fluorescence spectroscopy and transmission electron microscopy (TEM). Although PPG shows moderately hydrophilic character, the formation of nanosize polymeric micelles was confirmed by fluorescence and TEM studies. The low value of the critical aggregation concentration exhibited that the tendency for the formation of copolymer aggregates in aqueous solution was very high due to the strong hydrophobicity of the PHFBMA(145)-b-PPGA(33) block copolymer. The combination of DLS and SLS measurements revealed the existence of micellar aggregates in aqueous solution with an association number of approximately 40 +/- 7 for block copolymer micelles. It was also found in TEM observation that there are 40-50 micelles accumulated into one aggregate and these micelles are loosely packed inside the aggregate.

  11. Electrochemical Characterization of TiO 2 Blocking Layers for Dye-Sensitized Solar Cells

    KAUST Repository

    Kavan, Ladislav; Té treault, Nicolas; Moehl, Thomas; Grä tzel, Michael

    2014-01-01

    Thin compact layers of TiO2 are grown by thermal oxidation of Ti, by spray pyrolysis, by electrochemical deposition, and by atomic layer deposition. These layers are used in dye-sensitized solar cells to prevent recombination of electrons from

  12. Au-coated 3-D nanoporous titania layer prepared using polystyrene-b-poly(2-vinylpyridine) block copolymer nanoparticles.

    Science.gov (United States)

    Shin, Won-Jeong; Basarir, Fevzihan; Yoon, Tae-Ho; Lee, Jae-Suk

    2009-04-09

    New nanoporous structures of Au-coated titania layers were prepared by using amphiphilic block copolymer nanoparticles as a template. A 3-D template composed of self-assembled quaternized polystyrene-b-poly(2-vinylpyridine) (Q-PS-b-P2VP) block copolymer nanoparticles below 100 nm was prepared. The core-shell-type nanoparticles were well ordered three-dimensionally using the vertical immersion method on the substrate. The polar solvents were added to the polymer solution to prevent particle merging at 40 degrees C when considering the interaction between polymer nanoparticles and solvents. Furthermore, Au-coated PS-b-P2VP nanoparticles were prepared using thiol-capped Au nanoparticles (3 nm). The 3-D arrays with Au-coated PS-b-P2VP nanoparticles as a template contributed to the preparation of the nanoporous Au-coated titania layer. Therefore, the nanoporous Au-coated titania layer was fabricated by removing PS-b-P2VP block copolymer nanoparticles by oxygen plasma etching.

  13. Effects of arginine and phytogenic additive supplementation on performance and health of brown-egg layers

    Directory of Open Access Journals (Sweden)

    Vitor Barbosa Fascina

    Full Text Available ABSTRACT This study was performed to evaluate the effects of the association of different digestible arginine and phytogenic additive dietary levels on performance and health status of brown-egg layers. In this study, a total of 504 33-week-old Hisex Brown layers were distributed into a completely randomized experimental design to a 4 × 3 factorial arrangement (dietary digestible arginine levels: 880, 968, 1056, or 1144 mg/kg of feed × phytogenic additive levels: 0, 100, and 200 mg/kg of feed with six replicate cages of seven birds per cage. The phytogenic additive was composed of extracts of Baccharis dracunculifolia (40%, Astragalus membranaceus lipopolysaccharides (20%, cinnamon, and grape seed (20%. Feed intake was reduced when diets containing 1056 mg of arginine were supplemented with 100 or 200 mg phytogenic additive per kg. Feed conversion ratio was improved when diets were supplemented with 100 mg of phytogenic additive or with 1056 mg of arginine per kg of feed. Egg mass was increased when diets were supplemented with 1056 mg arginine per kg of feed. Arginine supplementation quadratically increased albumen percentage and reduced yolk percentage. Higher arginine and phytogenic additive levels reduced heterophyl:lymphocyte ratio and blood uric acid, total cholesterol, very-low density lipoprotein, and triglyceride levels. Dietary supplementation of 100 mg of phytogenic additive associated with high arginine levels increased nitric oxide production by peritoneal macrophages and 1056 mg of arginine increased antibodies titers against Newcastle disease virus. Blood and intestinal malonaldehyde levels were reduced when 200 mg of the phytogenic additive was added. Dietary supplementation of 968 mg of arginine or 100 mg of a phytogenic additive (40% Baccharis dracunculifolia, 20% Astragalus membranaceus, 20% cinnamon, and 20% grape seed extracts per kilogram of diet improves the feed conversion ratio and associated inclusion of 1144 mg of

  14. Effect of the addition of rocuronium to 2% lignocaine in peribulbar block for cataract surgery

    Directory of Open Access Journals (Sweden)

    Vishalakshi Patil

    2017-01-01

    Conclusion: The addition of rocuronium 5 mg to a mixture of lidocaine 2% with adrenaline and hyaluronidase 50 IU/ml shortened the onset time of peribulbar anesthesia in patients undergoing cataract surgery without causing adverse effects.

  15. Performance enhancement of perovskite solar cells with Mg-doped TiO2 compact film as the hole-blocking layer

    International Nuclear Information System (INIS)

    Wang, Jing; Qin, Minchao; Tao, Hong; Ke, Weijun; Chen, Zhao; Wan, Jiawei; Qin, Pingli; Lei, Hongwei; Fang, Guojia; Xiong, Liangbin; Yu, Huaqing

    2015-01-01

    In this letter, we report perovskite solar cells with thin dense Mg-doped TiO 2 as hole-blocking layers (HBLs), which outperform cells using TiO 2 HBLs in several ways: higher open-circuit voltage (V oc ) (1.08 V), power conversion efficiency (12.28%), short-circuit current, and fill factor. These properties improvements are attributed to the better properties of Mg-modulated TiO 2 as compared to TiO 2 such as better optical transmission properties, upshifted conduction band minimum (CBM) and downshifted valence band maximum (VBM), better hole-blocking effect, and higher electron life time. The higher-lying CBM due to the modulation with wider band gap MgO and the formation of magnesium oxide and magnesium hydroxides together resulted in an increment of V oc . In addition, the Mg-modulated TiO 2 with lower VBM played a better role in the hole-blocking. The HBL with modulated band position provided better electron transport and hole blocking effects within the device

  16. Heat transfer and material flow during laser assisted multi-layer additive manufacturing

    International Nuclear Information System (INIS)

    Manvatkar, V.; De, A.; DebRoy, T.

    2014-01-01

    A three-dimensional, transient, heat transfer, and fluid flow model is developed for the laser assisted multilayer additive manufacturing process with coaxially fed austenitic stainless steel powder. Heat transfer between the laser beam and the powder particles is considered both during their flight between the nozzle and the growth surface and after they deposit on the surface. The geometry of the build layer obtained from independent experiments is compared with that obtained from the model. The spatial variation of melt geometry, cooling rate, and peak temperatures is examined in various layers. The computed cooling rates and solidification parameters are used to estimate the cell spacings and hardness in various layers of the structure. Good agreement is achieved between the computed geometry, cell spacings, and hardness with the corresponding independent experimental results.

  17. Enhancing Color Purity and Stable Efficiency of White Organic Light Diodes by Using Hole-Blocking Layer

    Directory of Open Access Journals (Sweden)

    Chien-Jung Huang

    2014-01-01

    Full Text Available The organic light-emitting diodes with triple hole-blocking layer (THBL formation sandwich structure which generate white emission were fabricated. The 5,6,11,12-tetraphenylnapthacene (Rubrene, (4,4′-N,N′-dicarbazolebiphenyl (CBP, and 4,4′-bis(2,2′diphenylvinil-1,1′-biphenyl (DPVBi were used as emitting materials in the device. The function of CBP layer is not only an emitting layer but also a hole-blocking layer (HBL, and the Rubrene was doped into the CBP. The optimal configuration structure was indium tin oxide (ITO/Molybdenum trioxide (MoO3 (5 nm/[4,4-bis[N-(1-naphthyl-N-phenylamino]biphenyl (NPB (35 nm/CBP (HBL1 (5 nm/DPVBi (I (10 nm/CBP (HBL2 : Rubrene (4 : 1 (3 nm/DPVBi (II (30 nm/CBP (HBL3 (2 nm/4,7-diphenyl-1,10-phenanthroline (BPhen (10 nm/Lithium fluoride (LiF/aluminum (Al. The result showed that the device with Rubrene doped in CBP (HBL2 exhibited a stable white emission with the color coordinates of (0.322, 0.368, and the coordinate with the slight shift of ±Δx,y = (0.001, 0.011 for applied voltage of 8–12 V was observed.

  18. Mode I type delamination fracture toughness of YBCO coated conductor with additional Cu layer

    International Nuclear Information System (INIS)

    Miyazato, T.; Hojo, M.; Sugano, M.; Adachi, T.; Inoue, Y.; Shikimachi, K.; Hirano, N.; Nagaya, S.

    2011-01-01

    A fracture toughness test method was developed for a YBCO coated conductor with an additional Cu layer. Mode I type tests were carried out using double cantilever beam (DCB) specimens. Delamination propagated into the YBCO layer, and sometimes reached the Ag/YBCO interface. The fracture toughness for YBCO was about 10 J/m 2 . That for Ag/YBCO interface was about 100 J/m 2 . Although interlaminar fracture at a YBa 2 Cu 3 O 7-δ (YBCO)/CeO 2 interface was reported for YBCO coated conductors, this has not yet been investigated by a fracture mechanical approach. In the present study, we developed a mode I type fracture toughness test method for a YBCO coated conductor with an additional Cu layer using double cantilever beam (DCB) specimens. Fracture mechanism was investigated by microscopic observation by a scanning electron microscope (SEM), together with composition analysis by an energy dispersive X-ray spectroscope (EDS). A pre-crack introduced at the YBCO/CeO 2 interface deviated from the interface, and propagated into the YBCO layer, and sometimes reached the Ag/YBCO interface. The fracture toughness, G R , for YBCO and the Ag/YBCO interface was evaluated to be 7-10 J/m 2 and 80-120 J/m 2 , respectively. The complex stress intensity factor ratio, K 2 /K 1 , at YBCO/CeO 2 interface was evaluated to be -0.19, and this ratio controlled the formation of microcracks in the YBCO layer. The main crack propagated into the YBCO layer accompanied with the formation of microcracks.

  19. Synthesis of Polythiophene–Fullerene Hybrid Additives as Potential Compatibilizers of BHJ Active Layers

    Directory of Open Access Journals (Sweden)

    Sofia Kakogianni

    2016-12-01

    Full Text Available Perfluorophenyl functionalities have been introduced as side chain substituents onto regioregular poly(3-hexyl thiophene (rr-P3HT, under various percentages. These functional groups were then converted to azides which were used to create polymeric hybrid materials with fullerene species, either C60 or C70. The P3HT–fullerene hybrids thus formed were thereafter evaluated as potential compatibilizers of BHJ active layers comprising P3HT and fullerene based acceptors. Therefore, a systematic investigation of the optical and morphological properties of the purified polymer–fullerene hybrid materials was performed, via different complementary techniques. Additionally, P3HT:PC70BM blends containing various percentages of the herein synthesized hybrid material comprising rr-P3HT and C70 were investigated via Transmission Electron Microscopy (TEM in an effort to understand the effect of the hybrids as additives on the morphology and nanophase separation of this typically used active layer blend for OPVs.

  20. Mechanical Behavior of Additive Manufactured Layered Materials, Part 2: Stainless Steels

    Science.gov (United States)

    2015-04-30

    materials. Elsevier, Oxford; 2007: 416 -420. [19] Deng, D., Chen, R., Sun, Q. and Li, X. Microstructural study of 17-4PH stainless steel after plasma...1 Mechanical Behavior of Additive Manufactured Layered Materials, Part 2: Stainless Steels * Todd M. Mower † and Michael J. Long M.I.T. Lincoln... stainless steel alloys produced with Direct Metal Laser Sintering (DMLS) was measured and is compared to that of similar conventional materials

  1. A Statistical Analysis on the Coating Layer Thicknesses of a TRISO of 350 MWth Block-type HTR

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Min; Jo, C. K.; Cho, M. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    A tri-isotropic coated fuel particle (TRISO) is a basic fuel element of a high temperature reactor (HTR). The block-type HTR fuel is a cylindrical graphite compact in which a large number of TRISOs are embedded. There are more than 11 billion TRISOs in a 350 MW{sub th} block-type HTR core. Among the RSM quadratic models, the BBD model produces the smallest errors at both interior and exterior points. The errors in the quadratic model of the small-type CCD is the biggest, particularly at exterior points. The CCD has a disadvantage of generating a number of decimal places in its factor levels because of its axial points. It is recommended to use the BBD or the full-type CCD with an adjusted axial point which does not produce the decimal places in its factor levels. More general statistical model for a TRISO design will be secured when the number of factors and responses increases. This study treats a statistical analysis on the optimal layer thicknesses of a UCO TRISO of 350 MW{sub th} block-type HTR which cause a minimum tangential stress to act on the SiC layer. Three response surface methods (RSMs) are used as statistical methods and their resulting quadratic models are compared.

  2. A Statistical Analysis on the Coating Layer Thicknesses of a TRISO of 350 MWth Block-type HTR

    International Nuclear Information System (INIS)

    Kim, Young Min; Jo, C. K.; Cho, M. S.

    2016-01-01

    A tri-isotropic coated fuel particle (TRISO) is a basic fuel element of a high temperature reactor (HTR). The block-type HTR fuel is a cylindrical graphite compact in which a large number of TRISOs are embedded. There are more than 11 billion TRISOs in a 350 MW_t_h block-type HTR core. Among the RSM quadratic models, the BBD model produces the smallest errors at both interior and exterior points. The errors in the quadratic model of the small-type CCD is the biggest, particularly at exterior points. The CCD has a disadvantage of generating a number of decimal places in its factor levels because of its axial points. It is recommended to use the BBD or the full-type CCD with an adjusted axial point which does not produce the decimal places in its factor levels. More general statistical model for a TRISO design will be secured when the number of factors and responses increases. This study treats a statistical analysis on the optimal layer thicknesses of a UCO TRISO of 350 MW_t_h block-type HTR which cause a minimum tangential stress to act on the SiC layer. Three response surface methods (RSMs) are used as statistical methods and their resulting quadratic models are compared

  3. Energy resolution of a four-layer depth of interaction detector block for small animal PET

    International Nuclear Information System (INIS)

    Tsuda, Tomoaki; Kawai, Hideyuki; Orita, Narimichi; Murayama, Hideo; Yoshida, Eiji; Inadama, Naoko; Yamaya, Taiga; Omura, Tomohide

    2004-01-01

    We are now planning to develop a positron emission tomograph dedicated to small animals such as rats and mice which meets the demand for higher sensitivity. We proposed a new depth of interaction (DOI) detector arrangement to obtain DOI information by using a four-layer detector with all the same crystal elements. In this DOI detector, we control the behavior of scintillation photons by inserting the reflectors between crystal elements so that the DOI information of four layers can be extracted from one two-dimensional (2D) position histogram made by Anger-type calculation. In this work, we evaluate the energy resolution of this four-layer DOI detector. (author)

  4. Increased luminance of MEH-PPV and PFO based PLEDs by using salmon DNA as an electron blocking layer

    International Nuclear Information System (INIS)

    Madhwal, Devinder; Rait, S.S.; Verma, A.; Kumar, Amit; Bhatnagar, P.K.; Mathur, P.C.; Onoda, M.

    2010-01-01

    The effect of salmon DNA-CTMA as an electron blocking layer (EBL) has been examined on the performance of MEH-PPV and PFO-based light emitting diodes. Though the turn-on voltage increases with incorporation of EBL, a significant increase in luminance and luminous efficiency for both the devices is observed. The EBL improves the device performance by blocking electrons at the EBL-polymer interface, thereby increasing the recombination probability of electrons and holes. The luminance of the MEH-PPV based Bio-LED increases to 100 cd/m 2 from 30 cd/m 2 while a corresponding increase for the PFO based LED is to 160 cd/m 2 from 80 cd/m 2 with and without EBL, respectively.

  5. Improving the photovoltaic parameters in Quantum dot sensitized solar cells through employment of chemically deposited compact titania blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Rajendra Prasad, M.B., E-mail: rajendraprasadmb75@gmail.com [Advanced Physics Laboratory, Department of Physics, SavitibaiPhule Pune University, Pune, 411007 (India); National Defence Academy, Khadakwasla, Pune, 411023 (India); Kadam, Vishal [Advanced Physics Laboratory, Department of Physics, SavitibaiPhule Pune University, Pune, 411007 (India); Joo, Oh-Shim [Korea Institute of Science and Technology, PO Box No. 131, Chongryang, Seoul, 130-650 (Korea, Republic of); Pathan, Habib M. [Advanced Physics Laboratory, Department of Physics, SavitibaiPhule Pune University, Pune, 411007 (India)

    2017-06-15

    Incorporation of compact blocking layer at the Transparent Conducting Oxide (TCO)/Electrolyte interface is an effective method to improve the device performance in QDSSC through mitigation of electron recombinations at this interface. This paper reports the most facile and cost effective method of depositing a rutile titania Compact Layer (CL) over Fluorine doped Tin Oxide (FTO) substrate and its application in titania based CdS QD sensitized solar cells. The deposited compact layers are characterized to study their structural, optical, morphological and electrochemical properties using X-Ray Diffractometry, UV–Visible spectroscopy, Scanning electron microscopy, Cyclic Voltammetry and Contact Angle measurements. Sandwich solar cells are fabricated using these CL based electrodes and characterized using Electrochemical Impedance Spectroscopy, Open Circuit Voltage Decay and J-V characteristics. The CL incorporated CdS QDSSC showed more than 100% increase in the photoconversion efficiency (1.68%) as compared to its bare FTO counterpart (0.73%) proving the efficacy of employed strategy. - Highlights: • Deposited titania compact layer by a facile room temperature chemical bath method. • Employed this to mitigate back electron transfer at TCO/Electrolyte interface. • Compact layer incorporation has improved the solar cell performance by 130%.

  6. Development of ultra pure germanium epi layers for blocked impurity band far infrared detectors

    International Nuclear Information System (INIS)

    Lutz, M.P.

    1991-05-01

    The main goals of this paper are: (1) To develop a low-pressure CVD (LPCVD) process that allows epitaxial growth at lower temperatures. Lower temperatures will allow the achievement of a sharp dopant profile at the substrate/epi-layer interface. Less out-diffusion from the substrate would allow the use of thinner epitaxial layers, which would lead to a larger depletion width in the photoactive region. LPCVD also avoids, to a great extent, gas-phase nucleation, which would cause Ge particulates to fall onto the wafer surface during growth. (2) To reduce high levels of oxygen and copper present at the wafer interface, as observed by secondary ion mass spectroscopy (SIMS). In order to achieve high-quality epitaxial layers, it is imperative that the substrate surface be of excellent quality. (3) To make and test detectors, after satisfactory epitaxial layers have been made

  7. Fabrication and characterization of organic light-emitting diodes using zinc complexes as hole-blocking layer.

    Science.gov (United States)

    Kim, Won Sam; You, Jung Min; Lee, Burm-Jong; Jang, Yoon-Ki; Kim, Dong-Eun; Kwon, Young-Soo

    2006-11-01

    2-(2-Hydroxyphenyl)benzoxazole (HPB) was employed as organic ligand and the corresponding zinc complexes (Zn(HPB)2 and Zn(HPB)q) were synthesized. And their EL properties were characterized. The structures of zinc complexes were determined with FT-NMR, FT-IR, UV-Vis, and XPS. The thermal stability showed up to about 300 degrees C under nitrogen flow, which was measured by TGA. The photoluminescence (PL) of zinc complexes were measured from the DMF solution. The PL emitted in blue and yellow region, respectively. The EL devices were fabricated by the vacuum deposition. Two kinds of OLEDs devices were fabricated; ITO/NPB (40 nm)/Zn complexes (60 nm)/LiF/Al and ITO/NPB (40 nm)/Alq3 (60 nm)/Zn complexes (5 nm)/LiF/Al. Both of the EL properties as the emitting and the hole-blocking layer were investigated. The EL emission of Zn(HPB)q exhibited green light centered at 532 nm. The device showed a turn-on voltage at 5 V and a luminance of 6073 cd/m2 at 10 V. Meanwhile, the maximum EL the emission of the Zn(HPB)2 device was found to be at 447 nm. And the device showed a luminance of 2813 cd/m2 at 10 V. The ITO/NPB (40 nm)/Alq3 (60 nm)/Zn(HPB)2 (5 nm)/LiF/Al device showed increased luminance of L=17000 cd/m2 compared to L=12000 cd/m2 for similar device fabricated without the hole-blocking layer. And the turn-on voltage was significantly affected by the existence of the hole-blocking layer.

  8. Very thin thermally stable TiO2 blocking layers with enhanced electron transfer for solar cells

    Czech Academy of Sciences Publication Activity Database

    Kment, Š.; Krýsová, Hana; Hubička, Zdeněk; Kmentová, H.; Kavan, Ladislav; Zbořil, R.

    2017-01-01

    Roč. 9, DEC 2017 (2017), s. 122-129 ISSN 2352-9407 R&D Projects: GA MŠk(CZ) LM2015073; GA ČR GA13-07724S Grant - others:GA MŠk(CZ) LO1305 Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Cyclic voltammetry * Impedance spectroscopy * Photochemistry * Solar cell * TiO blocking layer 2 Subject RIV: CG - Electrochemistry; BM - Solid Matter Physics ; Magnetism (FZU-D) OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis); Condensed matter physics (including formerly solid state physics, supercond.) (FZU-D)

  9. Tailoring of polarization in electron blocking layer for electron confinement and hole injection in ultraviolet light-emitting diodes

    International Nuclear Information System (INIS)

    Lu, Yu-Hsuan; Pilkuhn, Manfred H.; Fu, Yi-Keng; Chu, Mu-Tao; Huang, Shyh-Jer; Su, Yan-Kuin; Wang, Kang L.

    2014-01-01

    The influence of the AlGaN electron blocking layer (EBL) with graded aluminum composition on electron confinement and hole injection in AlGaN-based ultraviolet light-emitting diodes (LEDs) are investigated. The light output power of LED with graded AlGaN EBL was markedly improved, comparing to LED with conventional EBL. In experimental results, a high increment of 86.7% can be obtained in light output power. Simulation analysis shows that via proper modification of the barrier profile from the last barrier of the active region to EBL, not only the elimination of electron overflow to p-type layer can be achieved but also the hole injection into the active region can be enhanced, compared to a conventional LED structure. The dominant factor to the performance improvement is shown to be the modulation of polarization field by the graded Al composition in EBL

  10. Improving the color purity and efficiency of blue organic light-emitting diodes (BOLED) by adding hole-blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C.J., E-mail: chien@nuk.edu.t [Department of Applied Physics, National University of Kaohsiung, 700 Kaohsiung University Road, Nan-Tzu, Kaohsiung, Taiwan (China); Kang, C.C. [Department of Electro-Optical Engineering, Southern Taiwan University of Technology, 1 Nan-Tai St., Yung-Kang City, Tainan, Taiwan (China); Lee, T.C. [Department of Electrical Engineering, Southern Taiwan University of Technology, 1 Nan-Tai St., Yung-Kang City, Tainan, Taiwan (China); Chen, W.R.; Meen, T.H. [Department of Electronic Engineering, National Formosa University, 64 Wen-Hwa Road, Hu-Wei, Yunlin, Taiwan (China)

    2009-11-15

    This work demonstrates the fabrication of a bright blue organic light-emitting diode (BOLED) with good color purity using 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi) and bathocuproine (BCP) as the emitting layer (EML) and the hole-blocking layer (HBL), respectively. Devices were prepared by vacuum deposition on indium tin oxide (ITO)-glass substrates. The thickness of DPVBi used in the OLED has an important effect on color and efficiency. The blue luminescence is maximal at 7670 cd/m{sup 2} when 13 V is applied and the BCP thickness is 2 nm. The CIE coordinate at a luminance of 7670 cd/m{sup 2} is (0.165, 0.173). Furthermore, the current efficiency is maximum at 4.25 cd/A when 9 V is applied.

  11. Improving the color purity and efficiency of blue organic light-emitting diodes (BOLED) by adding hole-blocking layer

    International Nuclear Information System (INIS)

    Huang, C.J.; Kang, C.C.; Lee, T.C.; Chen, W.R.; Meen, T.H.

    2009-01-01

    This work demonstrates the fabrication of a bright blue organic light-emitting diode (BOLED) with good color purity using 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi) and bathocuproine (BCP) as the emitting layer (EML) and the hole-blocking layer (HBL), respectively. Devices were prepared by vacuum deposition on indium tin oxide (ITO)-glass substrates. The thickness of DPVBi used in the OLED has an important effect on color and efficiency. The blue luminescence is maximal at 7670 cd/m 2 when 13 V is applied and the BCP thickness is 2 nm. The CIE coordinate at a luminance of 7670 cd/m 2 is (0.165, 0.173). Furthermore, the current efficiency is maximum at 4.25 cd/A when 9 V is applied.

  12. Tailoring of polarization in electron blocking layer for electron confinement and hole injection in ultraviolet light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yu-Hsuan; Pilkuhn, Manfred H. [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Fu, Yi-Keng; Chu, Mu-Tao [Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, Hsinchu 31040, Taiwan (China); Huang, Shyh-Jer, E-mail: yksu@mail.ncku.edu.tw, E-mail: totaljer48@gmail.com [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90095 (United States); Su, Yan-Kuin, E-mail: yksu@mail.ncku.edu.tw, E-mail: totaljer48@gmail.com [Department of Electrical Engineering, Institute of Microelectronics and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan (China); Department of Electronic Engineering, Kun-Shan University, Tainan 71003, Taiwan (China); Wang, Kang L. [Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90095 (United States)

    2014-03-21

    The influence of the AlGaN electron blocking layer (EBL) with graded aluminum composition on electron confinement and hole injection in AlGaN-based ultraviolet light-emitting diodes (LEDs) are investigated. The light output power of LED with graded AlGaN EBL was markedly improved, comparing to LED with conventional EBL. In experimental results, a high increment of 86.7% can be obtained in light output power. Simulation analysis shows that via proper modification of the barrier profile from the last barrier of the active region to EBL, not only the elimination of electron overflow to p-type layer can be achieved but also the hole injection into the active region can be enhanced, compared to a conventional LED structure. The dominant factor to the performance improvement is shown to be the modulation of polarization field by the graded Al composition in EBL.

  13. An integrated simulator of structure and anisotropic flow in gas diffusion layers with hydrophobic additives

    Science.gov (United States)

    Burganos, Vasilis N.; Skouras, Eugene D.; Kalarakis, Alexandros N.

    2017-10-01

    The lattice-Boltzmann (LB) method is used in this work to reproduce the controlled addition of binder and hydrophobicity-promoting agents, like polytetrafluoroethylene (PTFE), into gas diffusion layers (GDLs) and to predict flow permeabilities in the through- and in-plane directions. The present simulator manages to reproduce spreading of binder and hydrophobic additives, sequentially, into the neat fibrous layer using a two-phase flow model. Gas flow simulation is achieved by the same code, sidestepping the need for a post-processing flow code and avoiding the usual input/output and data interface problems that arise in other techniques. Compression effects on flow anisotropy of the impregnated GDL are also studied. The permeability predictions for different compression levels and for different binder or PTFE loadings are found to compare well with experimental data for commercial GDL products and with computational fluid dynamics (CFD) predictions. Alternatively, the PTFE-impregnated structure is reproduced from Scanning Electron Microscopy (SEM) images using an independent, purely geometrical approach. A comparison of the two approaches is made regarding their adequacy to reproduce correctly the main structural features of the GDL and to predict anisotropic flow permeabilities at different volume fractions of binder and hydrophobic additives.

  14. Highly efficient and reliable high power LEDs with patterned sapphire substrate and strip-shaped distributed current blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Shengjun [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Yuan, Shu; Liu, Yingce [Quantum Wafer Inc., Foshan 528251 (China); Guo, L. Jay [Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109 (United States); Liu, Sheng, E-mail: victor_liu63@126.com [School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072 (China); Ding, Han [State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2015-11-15

    Graphical abstract: - Highlights: • TEM is used to characterize threading dislocation existing in GaN epitaxial layer. • Effect of threading dislocation on optical and electrical of LEDs is discussed. • Strip-shaped SiO{sub 2} DCBL is designed to improve current spreading performance of LEDs. - Abstract: We demonstrated that the improvement in optical and electrical performance of high power LEDs was achieved using cone-shaped patterned sapphire substrate (PSS) and strip-shaped SiO{sub 2} distributed current blocking layer (DCBL). We found through transmission electron microscopy (TEM) observation that densities of both the screw dislocation and edge dislocation existing in GaN epitaxial layer grown on PSS were much less than that of GaN epitaxial layer grown on flat sapphire substrate (FSS). Compared to LED grown on FSS, LED grown on PSS showed higher sub-threshold forward-bias voltage and lower reverse leakage current, resulting in an enhancement in device reliability. We also designed a strip-shaped SiO{sub 2} DCBL beneath a strip-shaped p-electrode, which prevents the current from being concentrated on regions immediately adjacent the strip-shaped p-electrode, thereby facilitating uniform current spreading into the active region. By implementing strip-shaped SiO{sub 2} DCBL, light output power of high power PSS-LED chip could be further increased by 13%.

  15. Enhanced light extraction efficiency of GaN-based light-emittng diodes by nitrogen implanted current blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Deok; Oh, Seung Kyu; Park, Min Joo; Kwak, Joon Seop, E-mail: jskwak@sunchon.ac.kr

    2016-10-15

    Highlights: • A nitrogen implanted current-blocking layer was successfully demonstrated. • Light-extraction efficiency and radiant intensity was increased by more than 20%. • Ion implantation was successfully implemented in GaN based light-emitting diodes. - Abstract: GaN-based light emitting diodes (LEDs) with a nitrogen implanted current-blocking layer (CBL) were successfully demonstrated for improving the light extraction efficiency (LEE) and radiant intensity. The LEE and radiant intensity of the LEDs with a shallow implanted CBL with nitrogen was greatly increased by more than 20% compared to that of a conventional LED without the CBL due to an increase in the effective current path, which reduces light absorption at the thick p-pad electrode. Meanwhile, deep implanted CBL with a nitrogen resulted in deterioration of the LEE and radiant intensity because of formation of crystal damage, followed by absorption of the light generated at the multi-quantum well(MQW). These results clearly suggest that ion implantation method, which is widely applied in the fabrication of Si based devices, can be successfully implemented in the fabrication of GaN based LEDs by optimization of implanted depth.

  16. Influence of carbon conductive additives on electrochemical double-layer supercapacitor parameters

    Science.gov (United States)

    Kiseleva, E. A.; Zhurilova, M. A.; Kochanova, S. A.; Shkolnikov, E. J.; Tarasenko, A. B.; Zaitseva, O. V.; Uryupina, O. V.; Valyano, G. V.

    2018-01-01

    Electrochemical double-layer capacitors (EDLC) offer energy storage technology, highly demanded for rapid transition processes in transport and stationary applications, concerned with fast power fluctuations. Rough structure of activated carbon, widely used as electrode material because of its high specific area, leads to poor electrode conductivity. Therefore there is the need for conductive additive to decrease internal resistance and to achieve high specific power and high specific energy. Usually carbon blacks are widely used as conductive additive. In this paper electrodes with different conductive additives—two types of carbon blacks and single-walled carbon nanotubes—were prepared and characterized in organic electrolyte-based EDLC cells. Electrodes are based on original wood derived activated carbon produced by potassium hydroxide high-temperature activation at Joint Institute for High Temperatures RAS. Electrodes were prepared from slurry by cold-rolling. For electrode characterization cyclic voltammetry, impedance spectra analysis, equivalent series resistance measurements and galvanostatic charge-discharge were used.

  17. A tribo-mechanical analysis of PVA-based building-blocks for implementation in a 2-layered skin model.

    Science.gov (United States)

    Morales Hurtado, M; de Vries, E G; Zeng, X; van der Heide, E

    2016-09-01

    Poly(vinyl) alcohol hydrogel (PVA) is a well-known polymer widely used in the medical field due to its biocompatibility properties and easy manufacturing. In this work, the tribo-mechanical properties of PVA-based blocks are studied to evaluate their suitability as a part of a structure simulating the length scale dependence of human skin. Thus, blocks of pure PVA and PVA mixed with Cellulose (PVA-Cel) were synthesised via freezing/thawing cycles and their mechanical properties were determined by Dynamic Mechanical Analysis (DMA) and creep tests. The dynamic tests addressed to elastic moduli between 38 and 50kPa for the PVA and PVA-Cel, respectively. The fitting of the creep compliance tests in the SLS model confirmed the viscoelastic behaviour of the samples with retardation times of 23 and 16 seconds for the PVA and PVA-Cel, respectively. Micro indentation tests were also achieved and the results indicated elastic moduli in the same range of the dynamic tests. Specifically, values between 45-55 and 56-81kPa were obtained for the PVA and PVA-Cel samples, respectively. The tribological results indicated values of 0.55 at low forces for the PVA decreasing to 0.13 at higher forces. The PVA-Cel blocks showed lower friction even at low forces with values between 0.2 and 0.07. The implementation of these building blocks in the design of a 2-layered skin model (2LSM) is also presented in this work. The 2LSM was stamped with four different textures and their surface properties were evaluated. The hydration of the 2LSM was also evaluated with a corneometer and the results indicated a gradient of hydration comparable to the human skin. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Nickel hydroxide ultrathin nanosheets as building blocks for electrochemically active layers

    Czech Academy of Sciences Publication Activity Database

    Schneiderová, Barbora; Demel, Jan; Pleštil, Josef; Janda, Pavel; Bohuslav, Jan; Ihiawakrim, D.; Ersen, O.; Rogez, G.; Lang, Kamil

    2013-01-01

    Roč. 1, č. 37 (2013), s. 11429-11437 ISSN 2050-7488 R&D Projects: GA ČR GAP207/10/1447; GA ČR GP13-09462P Institutional support: RVO:61388980 ; RVO:61389013 ; RVO:61388955 Keywords : layered hydroxide * delamination * nanosheet * batteries Subject RIV: CA - Inorganic Chemistry; CD - Macromolecular Chemistry (UMCH-V); CF - Physical ; Theoretical Chemistry (UFCH-W)

  19. Influences of alcoholic solvents on spray pyrolysis deposition of TiO{sub 2} blocking layer films for solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Changyun, E-mail: jiangc@imre.a-star.edu.sg [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Koh, Wei Lin; Leung, Man Yin [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Hong, Wei [Department of Chemical Engineering and Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave West ON, Waterloo, Canada N2L 3G1 (Canada); Li, Yuning, E-mail: yuning.li@uwaterloo.ca [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore); Department of Chemical Engineering and Waterloo Institute for Nanotechnology (WIN), University of Waterloo, 200 University Ave West ON, Waterloo, Canada N2L 3G1 (Canada); Zhang, Jie [Institute of Materials Research and Engineering, A-STAR, 3 Research Link, 117602 Singapore (Singapore)

    2013-02-15

    Influences of alcoholic solvents for titanium diisopropoxide bis(acetylacetonate) (TPA) precursor solutions on the spray pyrolysis deposited TiO{sub 2} films and the photovoltaic performance of the solid-state dye-sensitized solar cells (SDSCs) using these TiO{sub 2} films as the blocking layers were investigated. Smooth TiO{sub 2} films were obtained by spray pyrolysis deposition of a TPA solution in isopropanol (IPA) at a relatively low temperature of 260 Degree-Sign C. On the other hand, when ethanol was used as solvent, the TiO{sub 2} films fabricated at the same temperature showed much rougher surfaces with many pinholes. Our results showed that ethanol reacts with TPA to form titanium diethoxide bis(acetylacetonate) (TEA), which requires a higher thermal decomposition temperature than that of TPA. SDSCs with TiO{sub 2} blocking layer films fabricated using a TPA solution in IPA showed higher power conversion efficiencies with smaller variations. - Graphical abstract: Alcoholic solvents used for the TiO{sub 2} precursor play a critical role in determining the surface morphology of blocking layers and thus the photovoltaic performance of the SDSCs. Highlights: Black-Right-Pointing-Pointer Solvent influences morphology of spray pyrolysis deposited TiO{sub 2} blocking layer. Black-Right-Pointing-Pointer Ethanol reacts with TPA, resulting poor quality of blocking layer. Black-Right-Pointing-Pointer Isopropanol is better than ethanol for obtaining smooth blocking layer. Black-Right-Pointing-Pointer SDSC with blocking layer made with isopropanol showed better performance.

  20. Layer-by-Layer Formation of Block-Copolymer-Derived TiO2 for Solid-State Dye-Sensitized Solar Cells

    KAUST Repository

    Guldin, Stefan

    2011-12-15

    Morphology control on the 10 nm length scale in mesoporous TiO 2 films is crucial for the manufacture of high-performance dye-sensitized solar cells. While the combination of block-copolymer self-assembly with sol-gel chemistry yields good results for very thin films, the shrinkage during the film manufacture typically prevents the build-up of sufficiently thick layers to enable optimum solar cell operation. Here, a study on the temporal evolution of block-copolymer-directed mesoporous TiO 2 films during annealing and calcination is presented. The in-situ investigation of the shrinkage process enables the establishment of a simple and fast protocol for the fabrication of thicker films. When used as photoanodes in solid-state dye-sensitized solar cells, the mesoporous networks exhibit significantly enhanced transport and collection rates compared to the state-of-the-art nanoparticle-based devices. As a consequence of the increased film thickness, power conversion efficiencies above 4% are reached. Fabrication of sufficiently thick mesoporous TiO 2 photoelectrodes with morphology control on the 10 nm length scale is essential for solid-state dye-sensitized solar cells (ss-DSC). This study of the temporal evolution of block-copolymer-directed mesoporous TiO 2 films during annealing and calcination enables the build-up of sufficiently thick films for high-performance ssDSC devices. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Fatigue Life of Titanium Alloys Fabricated by Additive Layer Manufacturing Techniques for Dental Implants

    Science.gov (United States)

    Chan, Kwai S.; Koike, Marie; Mason, Robert L.; Okabe, Toru

    2013-02-01

    Additive layer deposition techniques such as electron beam melting (EBM) and laser beam melting (LBM) have been utilized to fabricate rectangular plates of Ti-6Al-4V with extra low interstitial (ELI) contents. The layer-by-layer deposition techniques resulted in plates that have different surface finishes which can impact significantly on the fatigue life by providing potential sites for fatigue cracks to initiate. The fatigue life of Ti-6Al-4V ELI alloys fabricated by EBM and LBM deposition techniques was investigated by three-point testing of rectangular beams of as-fabricated and electro-discharge machined surfaces under stress-controlled conditions at 10 Hz until complete fracture. Fatigue life tests were also performed on rolled plates of Ti-6Al-4V ELI, regular Ti-6Al-4V, and CP Ti as controls. Fatigue surfaces were characterized by scanning electron microscopy to identify the crack initiation site in the various types of specimen surfaces. The fatigue life data were analyzed statistically using both analysis of variance techniques and the Kaplan-Meier survival analysis method with the Gehan-Breslow test. The results indicate that the LBM Ti-6Al-4V ELI material exhibits a longer fatigue life than the EBM counterpart and CP Ti, but a shorter fatigue life compared to rolled Ti-6Al-4V ELI. The difference in the fatigue life behavior may be largely attributed to the presence of rough surface features that act as fatigue crack initiation sites in the EBM material.

  2. Logic For Qualification And Industrialisation Of Additive Layer Manufacturing Parts For Spatial Application

    Science.gov (United States)

    Brindeau, Aymeric; Lopes, Jean-Louis; Brivot, Frederic; Bourneaud, Florent; Desagulier, Christian

    2012-07-01

    ASTRIUM Space Transportation has been manufacturing composite equipments for satellite for 25 years. For this business, the development of Additive Layer Manufacturing (ALM) processes has been identified as a real opportunity to improve design and performances. For satellite equipments, ASTRIUM ST has chosen to investigate in the Electron Beam Melting process (patented EBM® process from Arcam AB company) for the manufacturing of Titanium parts, in collaboration with MECACHROME who has developed strong skills in this ALM process. This first development step has been achieved by introducing a titanium part realised by EBM on an equipment of Atlantic Bird 7 satellite launched in September 2011. The new step consists in the formal industrialisation of the EBM process for the procurement of titanium parts for satellite equipments. The present paper describes the logic retained for this industrialisation. It includes the technical requirements but also the verifications and inspections which have to be performed to guarantee that technical requirements are met.

  3. Additive Manufacturing of PLA and CF/PLA Binding Layer Specimens via Fused Deposition Modeling

    Science.gov (United States)

    Li, Yuhang; Gao, Shiyou; Dong, Rongmei; Ding, Xuebing; Duan, Xiaoxi

    2018-02-01

    As one of the most popular additive manufacturing techniques, fused deposition modeling (FDM) is successfully applied in aerospace, automotive, architecture, and other fields to fabricate thermoplastic parts. Unfortunately, as a result of the limited nature of the mechanical properties and mass in raw materials, there is a pressing need to improve mechanical properties and reduce weight for FDM parts. Therefore, this paper presents an experiment of a special polylactic acid (PLA) and carbon fiber (CF)/PLA-laminated experimental specimen fabricated using the FDM process. The mechanical properties and mass analysis of the new composites for the PLA and CF/PLA binding layer specimen are investigated experimentally. Through the experimental analysis, one can conclude that the mass of laminated specimen is lighter than the CF/PLA specimen, and the tensile and flexural mechanical properties are higher than the pure PLA specimen.

  4. DOES THE ADDITION OF DEXAMETHASON TO LOCAL ANESTHETIC PROLONG THE ANALGESIA OF INTERSCALEN PLEXUS BRACHIALIS BLOCK IN PATIENTS WITH SHOULDER SURGERY?

    Directory of Open Access Journals (Sweden)

    Nancheva Jasminka

    2016-07-01

    Full Text Available Abstract: Introduction: Peripherial nerve blocks is a suitable alternative to general anesthesia especially for one-day case surgery. Interscalene approach of plexus brachialis block as much as supraclavicular and infraclavicular provide reliable, safe, effective, low cost and most complete anesthesia with satisfactory postoperative analgesia for upper limb surgery. Postoperative analgesia of plexus brachialis blocks can be prolonged by using different drugs as adjuvants with local anesthetics. Dexamethasone has been shown to prolong the duration of postoperative analgesia when given as an adjunct for peripheral nerve blocks. The investigation was randomized, prospective, double blinded and controlled study. Objective: The study was designed to compare the effects of dexamethasone administered as an adjunct to bupivacaine in interscalene brachial plexus block on the onset, duration and postoperative analgesia in patients under the shoulder surgery. Methods: A prospective, double-blind study was undertaken in patients scheduled for shoulder surgeries under the interscalene brachial plexus block. We enrolled 60 patients, ASA I-II both sexes, aged 19-65 years, weighing 54-89 kg, divided to two groups G1 and G2. The brachial plexus block was performed by interscalene approach and mixture of 2% lidocaine (12ml and 0.5% bupivacaine (22 ml either alone or combined with dexamethasone (4 mg. The block was performed by using double technique neurostimulator/ultrasound technique. Results: In our investigation we found a significant increase in onset and duration of motor and sensory block in Group G2 (with dexamethasone as compared to Group G1 patients (p < 0.01. Conclusion: Addition of dexamethasone to local anesthetic drugs in interscalene plexus brachialis block, significantly prolongs the duration of analgesia and motor block in patients undergoing shoulder arthroscopy. Moreover, it is a remarkably safe and costeffective method of providing

  5. Bulk heterojunction perovskite solar cells based on room temperature deposited hole-blocking layer: Suppressed hysteresis and flexible photovoltaic application

    Science.gov (United States)

    Chen, Zhiliang; Yang, Guang; Zheng, Xiaolu; Lei, Hongwei; Chen, Cong; Ma, Junjie; Wang, Hao; Fang, Guojia

    2017-05-01

    Perovskite solar cells have developed rapidly in recent years as the third generation solar cells. In spite of the great improvement achieved, there still exist some issues such as undesired hysteresis and indispensable high temperature process. In this work, bulk heterojunction perovskite-phenyl-C61-butyric acid methyl ester solar cells have been prepared to diminish hysteresis using a facile two step spin-coating method. Furthermore, high quality tin oxide films are fabricated using pulse laser deposition technique at room temperature without any annealing procedure. The as fabricated tin oxide film is successfully applied in bulk heterojunction perovskite solar cells as a hole blocking layer. Bulk heterojunction devices based on room temperature tin oxide exhibit almost hysteresis-free characteristics with power conversion efficiency of 17.29% and 14.0% on rigid and flexible substrates, respectively.

  6. Asphaltene-laden interfaces form soft glassy layers in contraction experiments: a mechanism for coalescence blocking.

    Science.gov (United States)

    Pauchard, Vincent; Rane, Jayant P; Banerjee, Sanjoy

    2014-11-04

    In previous studies, the adsorption kinetics of asphaltenes at the water-oil interface were interpreted utilizing a Langmuir equation of state (EOS) based on droplet expansion experiments.1-3 Long-term adsorption kinetics followed random sequential adsorption (RSA) theory predictions, asymptotically reaching ∼85% limiting surface coverage, which is similar to limiting random 2D close packing of disks. To extend this work beyond this slow adsorption process, we performed rapid contractions and contraction-expansions of asphaltene-laden interfaces using the pendant drop experiment to emulate a Langmuir trough. This simulates the rapid increase in interfacial asphaltene concentration that occurs during coalescence events. For the contraction of droplets aged in asphaltene solutions, deviation from the EOS consistently occurs at a surface pressure value ∼21 mN/m corresponding to a surface coverage ∼80%. At this point droplets lose the shape required for validity of the Laplace-Young equation, indicating solidlike surface behavior. On further contraction wrinkles appear, which disappear when the droplet is held at constant volume. Surface pressure also decreases down to an equilibrium value near that measured for slow adsorption experiments. This behavior appears to be due to a transition to a glassy interface on contraction past the packing limit, followed by relaxation toward equilibrium by desorption at constant volume. This hypothesis is supported by cycling experiments around the close-packed limit where the transition to and from a solidlike state appears to be both fast and reversible, with little hysteresis. Also, the soft glass rheology model of Sollich is shown to capture previously reported shear behavior during adsorption. The results suggest that the mechanism by which asphaltenes stabilize water-in-oil emulsions is by blocking coalescence due to rapid formation of a glassy interface, in turn caused by interfacial asphaltenes rapidly increasing in

  7. Rendering of surface-geometries at job-generation level for camouflaging the layered nature of Additively Manufactured parts

    DEFF Research Database (Denmark)

    Pedersen, D. B.; Hansen, H. N.; Nielsen, J. S.

    2014-01-01

    The layered nature of Additive Manufactured parts, specifically those given from the Fused Deposition Modelling (FDM) process, exhibit a distinct surface definition. The origin of this is from the 2.5D deposition scheme, which leaves the seam between the individual layers clearly visible.[1...

  8. 4P-NPD ultra thin-films as efficient exciton blocking layers in DBP/C70 based organic solar cells

    DEFF Research Database (Denmark)

    Patil, Bhushan Ramesh; Liu, Yiming; Qamar, Talha

    2017-01-01

    Exciton blocking effects from ultra thin layers of N,N'-di-1-naphthalenyl-N,N'-diphenyl [1,1':4',1'':4'',1'''-quaterphenyl]-4,4'''-diamine (4P-NPD) was investigated in small molecule based inverted Organic Solar Cells (OSCs) using Tetraphenyldibenzoperiflanthene (DBP) as the electron donor material...... and fullerene (C70) as the electron acceptor material. The short-circuit current density (Jsc) and PCE of the optimized OSCs with 0.7 nm thick 4P-NPD were approx. 16 % and 24 % higher, respectively, compared to reference devices without exciton blocking layers. Drift diffusion based device modeling...... was conducted to model the full Current density – Voltage (JV) characteristics and EQE spectrum of the OSCs, and photoluminescence measurements was conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies...

  9. 4P-NPD ultra-thin films as efficient exciton blocking layers in DBP/C70 based organic solar cells

    Science.gov (United States)

    Patil, Bhushan R.; Liu, Yiming; Qamar, Talha; Rubahn, Horst-Günter; Madsen, Morten

    2017-09-01

    Exciton blocking effects from ultra-thin layers of N,N‧-di-1-naphthalenyl-N,N‧-diphenyl [1,1‧:4‧,1″:4″,1‴-quaterphenyl]-4,4‴-diamine (4P-NPD) were investigated in small molecule-based inverted organic solar cells (OSCs) using tetraphenyldibenzoperiflanthene as the electron donor material and fullerene (C70) as the electron acceptor material. The short-circuit current density (J SC) and power conversion efficiency (PCE) of the optimized OSCs with 0.7 nm thick 4P-NPD were approximately 16% and 24% higher, respectively, compared to reference devices without exciton blocking layers (EBLs). Drift diffusion-based device modeling was conducted to model the full current density-voltage (JV) characteristics and external quantum efficiency spectrum of the OSCs, and photoluminescence measurements were conducted to investigate the exciton blocking effects with increasing thicknesses of the 4P-NPD layer. Importantly, coupled optical and electrical modeling studies of the device behaviors and exciton generation rates and densities in the active layer for different 4P-NPD layer thicknesses were conducted, in order to gain a complete understanding of the observed increase in PCE for 4P-NPD layer thicknesses up to 1 nm, and the observed decrease in PCE for layer thicknesses beyond 1 nm. This work demonstrates a route for guiding the integration of EBLs in OSC devices.

  10. Design and manufacture of high performance hollow engine valves by Additive Layer Manufacturing

    International Nuclear Information System (INIS)

    Cooper, D.; Thornby, J.; Blundell, N.; Henrys, R.; Williams, M.A.; Gibbons, G.

    2015-01-01

    Highlights: • High performance engine valve has been redesigned and optimised for and using ALM. • FEA was utilised to optimise and select a design for manufacture and testing. • Micro computed tomography was used in design and validation as an NDT technique. • Real world test of components was conducted to evaluate their performance. • Has demonstrated the potential for ALM in a high performance engineering context. - Abstract: Additive Layer Manufacture (ALM) of metallic components provides significant opportunities for the reduction of component weight, in order to realise improvements in vehicle fuel efficiency or performance. This paper examines the potential benefits of ALM with regard to reducing the weight of Internal Combustion Engine inlet or exhaust valves. A case study component is presented, for which an improved ALM design has been created, manufactured and evaluated. Micro-Computed Tomography (μ-CT) scanning was utilised to reverse engineer an original component, and to assess the ALM component’s internal geometry and material integrity. The case study valve was re-designed using Finite Element Analysis (FEA) to select a light weighted design which provides a conservative 9.4 g, (20%) weight saving on the Original Equipment Manufacturer (OEM) component. An engine test of over 175,000 cycles at between 2000 and 9500 rpm was conducted, after which μ-CT scanning confirmed no evidence of internal cracking, failure or significant deformation

  11. Additive Routes to Action Learning: Layering Experience Shapes Engagement of the Action Observation Network.

    Science.gov (United States)

    Kirsch, Louise P; Cross, Emily S

    2015-12-01

    The way in which we perceive others in action is biased by one's prior experience with an observed action. For example, we can have auditory, visual, or motor experience with actions we observe others perform. How action experience via 1, 2, or all 3 of these modalities shapes action perception remains unclear. Here, we combine pre- and post-training functional magnetic resonance imaging measures with a dance training manipulation to address how building experience (from auditory to audiovisual to audiovisual plus motor) with a complex action shapes subsequent action perception. Results indicate that layering experience across these 3 modalities activates a number of sensorimotor cortical regions associated with the action observation network (AON) in such a way that the more modalities through which one experiences an action, the greater the response is within these AON regions during action perception. Moreover, a correlation between left premotor activity and participants' scores for reproducing an action suggests that the better an observer can perform an observed action, the stronger the neural response is. The findings suggest that the number of modalities through which an observer experiences an action impacts AON activity additively, and that premotor cortical activity might serve as an index of embodiment during action observation. © The Author 2015. Published by Oxford University Press.

  12. Effect of hydrophobic additive on oxygen transport in catalyst layer of proton exchange membrane fuel cells

    Science.gov (United States)

    Wang, Shunzhong; Li, Xiaohui; Wan, Zhaohui; Chen, Yanan; Tan, Jinting; Pan, Mu

    2018-03-01

    Oxygen transport resistance (OTR) is a critical factor influencing the performance of proton exchange membrane fuel cells (PEMFCs). In this paper, an effective method to reduce the OTR of catalyst layers (CLs) by introducing a hydrophobic additive into traditional CLs is proposed. A low-molecular-weight polytetrafluoroethylene (PTFE) is selected for its feasibility to prepare an emulsion, which is mixed with a traditional catalyst ink to successfully fabricate the CL with PTFE of 10 wt%. The PTFE film exists in the mesopores between the carbon particles. The limiting current of the hydrophobic CL was almost 4000 mA/cm2, which is 500 mA/cm2 higher than that of the traditional CL. PTFE reduces the OTR of the CL in the dry region by as much as 24 s/m compared to the traditional CL and expands the dry region from 2000 mA/cm2 in the traditional CL to 2500 mA/cm2. Furthermore, the CL with the hydrophobic agent can improve the oxygen transport in the wet region (>2000 mA/cm2) more effectively than that in the dry region. All these results indicate that the CL with the hydrophobic agent shows a superior performance in terms of optimizing water management and effectively reduces the OTR in PEMFCs.

  13. Additive diagnostic role of imaging in glaucoma: optical coherence tomography and retinal nerve fiber layer photography.

    Science.gov (United States)

    Kim, Ko Eun; Kim, Seok Hwan; Oh, Sohee; Jeoung, Jin Wook; Suh, Min Hee; Seo, Je Hyun; Kim, Martha; Park, Ki Ho; Kim, Dong Myung

    2014-11-20

    To investigate the additive diagnostic role of spectral-domain optical coherence tomography (SD-OCT) and red-free retinal nerve fiber layer photography (RNFLP) in making clinical glaucoma diagnosis. Four diagnostic combination sets, including the most recent image from each measurement of 196 glaucoma eyes (including the 44 preperimetric glaucoma eyes) and 101 healthy eyes, were prepared: (1) stereo disc photography and Humphrey visual field (SH), (2) SH and SD-OCT (SHO), (3) SH and RNFLP (SHR), and (4) SHR and SD-OCT (SHRO). Each randomly sorted set was serially presented at 1-month intervals to five glaucoma specialists who were asked to evaluate them in a subjective and independent manner. The specialists' glaucoma-diagnostic performances based on the sets were then compared. For each specialist, adding SD-OCT to SH or SHR increased the glaucoma-diagnostic sensitivity but not to a level of statistical significance. For one specialist, adding RNFLP to SH significantly increased the sensitivity. Each specialist showed a high level of specificity regardless of the diagnostic set. The overall sensitivity of all specialists' assessments was significantly increased by adding RNFLP or the combination of SD-OCT and RNFLP to SH (P < 0.001); however, adding SD-OCT to SH or SHR did not significantly increase the sensitivity. A similar relationship was noted also for the preperimetric glaucoma subgroup. In contrast to RNFLP, SD-OCT did not significantly enhance the diagnostic accuracy of detecting glaucoma or even of preperimetric glaucoma. Our results suggest that, at least for glaucoma specialists, the additive diagnostic role of OCT is limited. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  14. Randomized controlled trial to study the effect of dexamethasone as additive to ropivacaine on duration of ultrasound-guided transversus abdominis plane block in cesarean section

    Directory of Open Access Journals (Sweden)

    Jasleen Sachdeva

    2016-01-01

    Full Text Available Background: Transversus abdominis plane (TAP block is a regional anesthesia technique whose efficacy has been proven for postoperative pain relief after cesarean section (CS. Dexamethasone, a glucocorticoid, is now emerging as a new adjunct to local anesthetics for prolonging the duration of action and has been studied in different brachial plexus blocks. The primary outcome was to study the effect of dexamethasone as additive to ropivacaine on the duration of TAP block as assessed by time to first analgesic (TFA . The secondary outcome was total postoperative analgesic consumption, postoperative nausea and vomiting, and patient satisfaction. Method: This RCT was conducted on seventy American Society of Anesthesiology Grade I and II patients undergoing CS under subarachnoid block. Patients were randomly allocated to two groups comprising 35 patients each. Patients in Group I received ultrasound-guided bilateral TAP block at the end of surgery using 40 ml ropivacaine 0.2% and 2 ml saline, and patients in Group II received the block using 40 ml ropivacaine 0.2% and 2 ml (8 mg dexamethasone. Result: TFA was significantly longer in Group II (5.92 ± 1.02 vs. 3.11 ± 0.82 h, P = 0. Group II also had decreased tramadol requirement postoperatively (100.00 ± 0.00 vs. 140.00 ± 50.26 mg, P = 0.046. The incidence of nausea and vomiting was also lower (82.86% vs. 97.14%, P = 0.02318. The patient satisfaction with regard to pain relief was more (57.14% vs. 25.71%, P = 0.038. Conclusion: Addition of dexamethasone to ropivacaine in TAP block prolonged the duration of the block. There was no complication seen with TAP block in any of the patients.

  15. Effect of Fe inter-diffusion on properties of InP layers grown with addition of RE elements

    International Nuclear Information System (INIS)

    Prochazkova, O.; Zavadil, J.; Zdansky, K.

    2005-01-01

    This contribution reports the redistribution behaviour of Fe during the growth of InP layers from liquid phase with addition of some rare earth elements on semi-insulating InP:Fe substrates. We have studied the influence of different rare earths on the Fe diffusion into InP layer and compared it with the phenomenon of an extraction of iron from Fe doped materials into adjacent layers doped by Zn, Cd and Be, reported recently. In the case of Tm addition a conversion of electrical conductivity of InP layer to semi-insulating as a consequence of Fe diffusion has been observed while no significant Fe inter-diffusion has been confirmed in the presence of other investigated rare earth additions. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Effect of W addition on the electroless deposited NiP(W) barrier layer

    International Nuclear Information System (INIS)

    Tao, Yishi; Hu, Anmin; Hang, Tao; Peng, Li; Li, Ming

    2013-01-01

    Electroless deposition of NiP, NiWP thin film on p-type Si as the barrier layer to prevent the diffusion of Cu into Si was investigated. The thermal stability of the Si/Ni(W)P/Cu layers were evaluated by measuring the changes of resistance of the samples after annealed at various temperatures. XRD was applied to detect the formation of Cu 3 Si and evaluate the barrier performance of the layers. The results of XRD of the stacked Si/NiP/Cu, Si/NiWP-1/Cu, Si/NiWP–2/Cu films reveal that Cu atom could diffuse through NiP barrier layer at 450 °C, Cu could hardly diffuse through NiWP layer at 550 °C. This means that with W added in the layer, the barrier performance is improved. Although the resistance of Si/NiWP-1 and Si/NiWP-2 are higher than that of Si/NiP, the resistance of stacked layers of Si/NiWP-1/Cu and Si/NiWP–2/Cu are close to that of Si/NiP/Cu. This means that using NiWP as barrier layer is acceptable.

  17. Enhancing carrier injection in the active region of a 280nm emission wavelength LED using graded hole and electron blocking layers

    KAUST Repository

    Janjua, Bilal

    2014-02-27

    A theoretical investigation of AlGaN UV-LED with band engineering of hole and electron blocking layers (HBL and EBL, respectively) was conducted with an aim to improve injection efficiency and reduce efficiency droop in the UV LEDs. The analysis is based on energy band diagrams, carrier distribution and recombination rates (Shockley-Reed-Hall, Auger, and radiative recombination rates) in the quantum well, under equilibrium and forward bias conditions. Electron blocking layer is based on AlaGa1-aN / Al b → cGa1-b → 1-cN / AldGa 1-dN, where a < d < b < c. A graded layer sandwiched between large bandgap AlGaN materials was found to be effective in simultaneously blocking electrons and providing polarization field enhanced carrier injection. The graded interlayer reduces polarization induced band bending and mitigates the related drawback of impediment of holes injection. Similarly on the n-side, the Alx → yGa1-x → 1-yN / AlzGa 1-zN (x < z < y) barrier acts as a hole blocking layer. The reduced carrier leakage and enhanced carrier density in the active region results in significant improvement in radiative recombination rate compared to a structure with the conventional rectangular EBL layers. The improvement in device performance comes from meticulously designing the hole and electron blocking layers to increase carrier injection efficiency. The quantum well based UV-LED was designed to emit at 280nm, which is an effective wavelength for water disinfection application.

  18. Enhancing carrier injection in the active region of a 280nm emission wavelength LED using graded hole and electron blocking layers

    KAUST Repository

    Janjua, Bilal; Ng, Tien Khee; Alyamani, Ahmed Y.; El-Desouki, Munir M.; Ooi, Boon S.

    2014-01-01

    A theoretical investigation of AlGaN UV-LED with band engineering of hole and electron blocking layers (HBL and EBL, respectively) was conducted with an aim to improve injection efficiency and reduce efficiency droop in the UV LEDs. The analysis is based on energy band diagrams, carrier distribution and recombination rates (Shockley-Reed-Hall, Auger, and radiative recombination rates) in the quantum well, under equilibrium and forward bias conditions. Electron blocking layer is based on AlaGa1-aN / Al b → cGa1-b → 1-cN / AldGa 1-dN, where a < d < b < c. A graded layer sandwiched between large bandgap AlGaN materials was found to be effective in simultaneously blocking electrons and providing polarization field enhanced carrier injection. The graded interlayer reduces polarization induced band bending and mitigates the related drawback of impediment of holes injection. Similarly on the n-side, the Alx → yGa1-x → 1-yN / AlzGa 1-zN (x < z < y) barrier acts as a hole blocking layer. The reduced carrier leakage and enhanced carrier density in the active region results in significant improvement in radiative recombination rate compared to a structure with the conventional rectangular EBL layers. The improvement in device performance comes from meticulously designing the hole and electron blocking layers to increase carrier injection efficiency. The quantum well based UV-LED was designed to emit at 280nm, which is an effective wavelength for water disinfection application.

  19. A novel strategy for high-stability lithium sulfur batteries by in situ formation of polysulfide adsorptive-blocking layer

    Science.gov (United States)

    Jin, Liming; Li, Gaoran; Liu, Binhong; Li, Zhoupeng; Zheng, Junsheng; Zheng, Jim P.

    2017-07-01

    Lithium sulfur (Lisbnd S) batteries are one of the most promising energy storage devices owing to their high energy and power density. However, the shuttle effect as a key barrier hinders its practical application by resulting in low coulombic efficiency and poor cycling performance. Herein, a novel design of in situ formed polysulfide adsorptive-blocking layer (PAL) on the cathode surface was developed to tame the polysulfide shuttling and promote the cycling stability for Lisbnd S batteries. The PAL is consisted of La2S3, which is capable to chemically adsorb polysulfide via the strong interaction of Lasbnd S bond and Ssbnd S bond, and build an effective barrier against sulfur escaping. Moreover, the La2S3 is capable to suppress the crystallization of Li2S and promote the ion transfer, which contributes to the reduced internal resistance of batteries. Furthermore, the by-product LiNO3 simultaneously forms a stable anode solid and electrolyte interface to further inhibit the polysulfide shuttle. By this simple and convenient method, the resultant Lisbnd S batteries achieved exceptional cycling stability with an ultralow decay rate of 0.055% since the 10th cycle.

  20. Experimental study of core bypass flow in a prismatic VHTR based on a two-layer block model

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huhu, E-mail: huhuwang@tamu.edu; Hassan, Yassin A., E-mail: y-hassan@tamu.edu; Dominguez-Ontiveros, Elvis, E-mail: elvisdom@tamu.edu

    2016-09-15

    Bypass flow in a prismatic very high temperature gas-cooled nuclear reactor (VHTR) plays an important role in determining the coolant distribution in the core region. Efficient removal of heat from the core relies on the majority of coolant passing through the coolant channels instead of the bypass gaps. Consequently, the bypass flow fraction and its flow characteristic are important in the design process of the prismatic VHTR. The objective of this study is to experimentally investigate the flow behavior including the turbulence characteristics inside the bypass gaps using laser Doppler velocimetry (LDV), bypass fraction and pressure drops in the system. The experiment facility constructed at Texas A&M University is a scaled model consisting of two layers of fuel blocks. The distributions of the mean streamwise velocity, turbulence intensity and turbulence kinetic energy within the bypass gap at two different elevations under different Reynolds number were investigated. Uncertainties in the bypass flow fraction estimation were evaluated. The velocity and turbulence study in this work is considered to be unique, and may serve as a benchmark for the related numerical calculations.

  1. Enhancement of Endurance in HfO2-Based CBRAM Device by Introduction of a TaN Diffusion Blocking Layer

    KAUST Repository

    Chand, Umesh

    2017-08-05

    We propose a new method to improve resistive switching properties in HfO2 based CBRAM crossbar structure device by introducing a TaN thin diffusion blocking layer between the Cu top electrode and HfO2 switching layer. The Cu/TaN/HfO2/TiN device structure exhibits high resistance ratio of OFF/ON states without any degradation in switching during endurance test. The improvement in the endurance properties of the Cu/TaN/HfO2/TiN CBRAM device is thus attributed to the relatively low amount of Cu migration into HfO2 switching layer.

  2. The improvement of GaN-based LED grown on concave nano-pattern sapphire substrate with SiO2 blocking layer

    International Nuclear Information System (INIS)

    Lin, Jyun-Hao; Huang, Shyh-Jer; Su, Yan-Kuin; Huang, Kai-Wen

    2015-01-01

    Highlights: • Concave nano-patterned sapphire substrates with SiO 2 blocking layer. • The IQE is almost two times larger than that of conventional one. • The EQE was extremely enhanced more than 100%. - Abstract: In contrast to convex nano-pattern sapphire substrates (NPSS), which are frequently used to fabricate high-quality nitride-based light-emitting diodes (LEDs), concave NPSS have been paid relatively less attention. In this study, a concave NPSS was fabricated, and its nitride epitaxial growth process was evaluated in a step by step manner. A SiO 2 layer was used to avoid nucleation over the sidewall and bottom of the nano-patterns to reduce dislocation reformation. Traditional LED structures were grown on the NPSS layer to determine its influence on device performance. X-ray diffraction, etched pit density, inverse leakage current, and internal quantum efficiency (IQE) results showed that dislocations and non-radiative recombination centers are reduced by the NPSS constructed with a SiO 2 blocking layer. An IQE twice that on a planar substrate was also achieved; such a high IQE significantly enhanced the external quantum efficiency of the resultant device. Taken together, the results demonstrate that the SiO 2 blocking layer proposed in this work can enhance the performance of LEDs.

  3. Electrodeposition of Fe_3O_4 layer from solution of Fe_2(SO_4)_3 with addition ethylene glycol

    International Nuclear Information System (INIS)

    Dahlan, Dahyunir; Asrar, Allan

    2016-01-01

    The electrodeposition of Fe_3O_4 layer from the solution Fe_2(SO_4)_3 with the addition of ethylene glycol on Indium Tin Oxide (ITO) substrate has been performed. The electrodeposition was carried out using a voltage of 5 volts for 120 seconds, with and without the addition of 2% wt ethylene glycol. Significant effects of temperature on the resulting the samples is observed when they are heated at 400 °C. Structural characterization using X-ray diffraction (XRD) shows that all samples produce a layer of Fe_3O_4 with particle size less than 50 nanometers. The addition of ethylene glycol and the heating of the sample causes a shrinkage in particle size. The scanning electron microscopy (SEM) characterization shows that Fe_3O_4 layer resulting from the process of electrodeposition of Fe_2(SO_4)_3 without ethylene glycol, independent of whether the sample is heated or not, is uneven and buildup. Layer produced by the addition of ethylene glycol without heating produces spherical particles. On contrary, when the layer is heated the spherical particles transform to irregularly-shaped particles with smaller size.

  4. Effects of Au nanoparticle addition to hole transfer layer in organic solar cells based on copper naphthalocyanine and fullerene

    Institute of Scientific and Technical Information of China (English)

    Akihiko Nagata; Takeo Okun; Tsuyoshi Akiyaman; Atsushi Suzuki

    2014-01-01

    Organic solar cells based on copper naphthalocyanine (CuNc) and fullerene (C60) were fabricated, and their photovoltaic properties were investigated. C60 and CuNc were used as n-type and p-type semiconductors, respectively. In addition, the effect of Au nanoparticle addition on a hole transfer layer was investigated, and the power conversion efficiency of the devices was improved after blending the Au nanoparticles into the hole transport layer. Nanostructures of Au nanoparticles were investigated by transmission electron microscopy and X-ray diffraction. Energy levels of molecules were calculated by molecular orbital calculations, and the nanostructure and electronic properties were discussed.

  5. Synthesis of butyl acrylate-styrene block copolymers in emulsion by reversible addition-fragmentation chain transfer : effect of surfactant migration upon film formation

    NARCIS (Netherlands)

    Monteiro, M.J.; Sjöberg, M.; Göttgens, C.M.; Vlist, van der J.

    2000-01-01

    The synthesis of block copolymers in an environmentally friendly medium was carried out in emulsion polymerizations through the reversible addition-fragmentation chain transfer process, using a transfer active xanthate (MADIX) agent, under batch and starved-feed conditions. First, ab initio

  6. No Additional Benefits of Block- Over Evenly-Distributed High-Intensity Interval Training within a Polarized Microcycle.

    Science.gov (United States)

    McGawley, Kerry; Juudas, Elisabeth; Kazior, Zuzanna; Ström, Kristoffer; Blomstrand, Eva; Hansson, Ola; Holmberg, Hans-Christer

    2017-01-01

    Introduction: The current study aimed to investigate the responses to block- versus evenly-distributed high-intensity interval training (HIT) within a polarized microcycle. Methods: Twenty well-trained junior cross-country skiers (10 males, age 17.6 ± 1.5 and 10 females, age 17.3 ± 1.5) completed two, 3-week periods of training (EVEN and BLOCK) in a randomized, crossover-design study. In EVEN, 3 HIT sessions (5 × 4-min of diagonal-stride roller-skiing) were completed at a maximal sustainable intensity each week while low-intensity training (LIT) was distributed evenly around the HIT. In BLOCK, the same 9 HIT sessions were completed in the second week while only LIT was completed in the first and third weeks. Heart rate (HR), session ratings of perceived exertion (sRPE), and perceived recovery (pREC) were recorded for all HIT and LIT sessions, while distance covered was recorded for each HIT interval. The recovery-stress questionnaire for athletes (RESTQ-Sport) was completed weekly. Before and after EVEN and BLOCK, resting saliva and muscle samples were collected and an incremental test and 600-m time-trial (TT) were completed. Results: Pre- to post-testing revealed no significant differences between EVEN and BLOCK for changes in resting salivary cortisol, testosterone, or IgA, or for changes in muscle capillary density, fiber area, fiber composition, enzyme activity (CS, HAD, and PFK) or the protein content of VEGF or PGC-1α. Neither were any differences observed in the changes in skiing economy, [Formula: see text] or 600-m time-trial performance between interventions. These findings were coupled with no significant differences between EVEN and BLOCK for distance covered during HIT, summated HR zone scores, total sRPE training load, overall pREC or overall recovery-stress state. However, 600-m TT performance improved from pre- to post-training, irrespective of intervention ( P = 0.003), and a number of hormonal and muscle biopsy markers were also significantly

  7. Efficient blue-green and green electroluminescent devices obtained by doping iridium complexes into hole-block material as supplementary light-emitting layer

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Liang [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Zheng, Youxuan, E-mail: yxzheng@mail.nju.edu.cn [State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Deng, Ruiping; Feng, Jing; Song, Mingxing; Hao, Zhaomin [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Zhang, Hongjie, E-mail: hongjie@ciac.jl.cn [State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Zuo, Jinglin; You, Xiaozeng [State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China)

    2014-04-15

    In this work, organic electroluminescent (EL) devices with dominant and supplementary light-emitting layers (EMLs) were designed to further improve the EL performances of two iridium{sup III}-based phosphorescent complexes, which have been reported to provide EL devices with slow EL efficiency roll-off. The widely used hole-block material 2,2′,2''-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) was selected as host material to construct the supplementary EML. Compared with single-EML devices, double-EMLs devices showed higher EL efficiencies, higher brightness, and lower operation voltage attributed to wider recombination zone and better balance of carriers. In addition, the insertion of supplementary EML is instrumental in facilitating carriers trapping, thus improving the color purity. Finally, high performance blue-green and green EL devices with maximum current efficiencies of 35.22 and 90.68 cd/A, maximum power efficiencies of 26.36 and 98.18 lm/W, and maximum brightness of 56,678 and 112,352 cd/m{sup 2}, respectively, were obtained by optimizing the doping concentrations. Such a device design strategy extends the application of a double EML device structure and provides a chance to simplify device fabrication processes. -- Highlights: • Electroluminescent devices with supplementary light-emitting layer were fabricated. • Doping concentrations and thicknesses were optimized. • Better balance of holes and electrons causes the enhanced efficiency. • Improved carrier trapping suppresses the emission of host material.

  8. Improving the performance of AlGaN-based deep-ultraviolet light-emitting diodes using electron blocking layer with a heart-shaped graded Al composition

    Science.gov (United States)

    Kwon, M. R.; Park, T. H.; Lee, T. H.; Lee, B. R.; Kim, T. G.

    2018-04-01

    We propose a design for highly efficient AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs) using a heart-shaped graded Al composition electron-blocking layer (EBL). This novel structure reduced downward band bending at the interface between the last quantum barrier and the EBL and flattened the electrostatic field in the interlayer between the barriers of the multi-quantum barrier EBL. Consequently, electron leakage was significantly suppressed and hole injection efficiency was found to have improved. The parameter values of simulation were extracted from the experimental data of the reference DUV LEDs. Using the SimuLED, we compared the electrical and optical properties of three structures with different Al compositions in the active region and the EBL. The internal quantum efficiency of the proposed structure was shown to exceed those of the reference DUV LEDs by a factor of 1.9. Additionally, the output power at 20 mA was found to increase by a factor of 2.1.

  9. Transition layers formation on the boundaries carbon fiber-copper dependence on the active additions

    International Nuclear Information System (INIS)

    Wlosinski, W.; Pietrzak, K.

    1993-01-01

    The basic problem connected with fabrication of carbon fiber-copper composites is to overcome the problem of low wettability of carbon fiber by copper. One of the possible solutions of that problem is to use the copper doped with active metals. The investigation results of transition layer forming on the phase boundary in the system have been discussed in respect of the kind and content of active elements added to the copper. 5 refs, 5 figs, 5 tabs

  10. Dynamics of proteins and of their hydration layer studied by neutron scattering and additional biophysical methods

    International Nuclear Information System (INIS)

    Gallat, Francois-Xavier

    2011-01-01

    This thesis work focused on the dynamics of proteins, surrounded by their hydration layer, a water shell around the protein vital for its biological function. Each of these components is accompanied by a specific dynamics which union reforms the complex energy landscape of the system. The joint implementation of selective deuteration, incoherent neutron scattering and tera-hertz spectroscopy allowed to explore the dynamics of proteins and that of the hydration shell. The influence of the folding state of protein on its dynamics has been studied by elastic neutron scattering. Globular proteins were less dynamic than its intrinsically disordered analogues. Themselves appear to be stiffer than non-physiological unfolded proteins. The oligomerization state and the consequences on the dynamics were investigated. Aggregates of a globular protein proved to be more flexible than the soluble form. In contrast, aggregates of a disordered protein showed lower average dynamics compared to the soluble form. These observations demonstrate the wide range of dynamics among the proteome. Incoherent neutron scattering experiences on the hydration layer of globular and disordered proteins have yielded information on the nature of water motion around these proteins. The measurements revealed the presence of translational motions concomitant with the onset of the transition dynamics of hydration layers, at 220 K. Measurements have also shown a stronger coupling between a disordered protein and its hydration water, compared to a globular protein and its hydration shell. The nature of the hydration layer and its influence on its dynamics has been explored with the use of polymers that mimic the water behavior and that act as a source of flexibility for the protein. Eventually, the dynamics of methyl groups involved in the dynamical changes observed at 150 and 220 K, was investigated. (author) [fr

  11. Mixed layers of sodium caseinate + dextran sulfate: influence of order of addition to oil-water interface.

    Science.gov (United States)

    Jourdain, Laureline S; Schmitt, Christophe; Leser, Martin E; Murray, Brent S; Dickinson, Eric

    2009-09-01

    We report on the interfacial properties of electrostatic complexes of protein (sodium caseinate) with a highly sulfated polysaccharide (dextran sulfate). Two routes were investigated for preparation of adsorbed layers at the n-tetradecane-water interface at pH = 6. Bilayers were made by the layer-by-layer deposition technique whereby polysaccharide was added to a previously established protein-stabilized interface. Mixed layers were made by the conventional one-step method in which soluble protein-polysaccharide complexes were adsorbed directly at the interface. Protein + polysaccharide systems gave a slower decay of interfacial tension and stronger dilatational viscoelastic properties than the protein alone, but there was no significant difference in dilatational properties between mixed layers and bilayers. Conversely, shear rheology experiments exhibited significant differences between the two kinds of interfacial layers, with the mixed system giving much stronger interfacial films than the bilayer system, i.e., shear viscosities and moduli at least an order of magnitude higher. The film shear viscoelasticity was further enhanced by acidification of the biopolymer mixture to pH = 2 prior to interface formation. Taken together, these measurements provide insight into the origin of previously reported differences in stability properties of oil-in-water emulsions made by the bilayer and mixed layer approaches. Addition of a proteolytic enzyme (trypsin) to both types of interfaces led to a significant increase in the elastic modulus of the film, suggesting that the enzyme was adsorbed at the interface via complexation with dextran sulfate. Overall, this study has confirmed the potential of shear rheology as a highly sensitive probe of associative electrostatic interactions and interfacial structure in mixed biopolymer layers.

  12. The influence of polarity of additive molecules on micelle structures of polystyrene-block-poly(4-vinylpyridine) in the fabrication of nano-porous templates.

    Science.gov (United States)

    Chua, Kee Sze; Koh, Ai Peng; Lam, Yeng Ming

    2010-11-01

    Block copolymers are useful for in situ synthesis of nanoparticles as well as producing nanoporous templates. As such, the effects of precursors on the block copolymer micelle structure is important. In this study, we investigate the effects of polarity of molecules introduced into block copolymer micelle cores on the micelle structure. The molecular dipole moment of the additive molecules has been evaluated and their effects on the block copolymer micelles investigated using light scattering spectroscopy, small-angle X-ray scattering, transmission electron microscopy and atomic force microscopy. The molecule with the largest dipole moment resulted in spherical structures with a polydispersity of less than 0.06 in a fully translational diffusion system. Surprisingly, the less polar additive molecules produced elongated micelles and the aspect ratio increases with decreasing polarity. The change in structure from spherical to elongated structure was attributed to P4VP chain extension, where compounds with polarity most similar to P4VP induce the most chain extension. The second virial coefficients of the solutions with elongated micelles are lower than that for spherical micelle systems by up to one order in magnitude, indicating a strong tendency for micelles to coalesce. On rinsing the spin-cast films, pores were obtained from spherical micelles and ridges from elongated micelles, suggesting a viable alternative for morphology modification using mild conditions where external annealing treatments to the film are not preferred. The knowledge of polarity effects of additive molecules on micelle structure has wider implications for supramolecular block copolymer systems where, depending on the application requirements, changes to the shape of the micelle structure can be induced or avoided. Copyright 2010 Elsevier Inc. All rights reserved.

  13. Flexible strategy for immobilizing redox-active compounds using in situ generation of diazonium salts. Investigations of the blocking and catalytic properties of the layers.

    Science.gov (United States)

    Noël, Jean-Marc; Sjöberg, Béatrice; Marsac, Rémi; Zigah, Dodzi; Bergamini, Jean-François; Wang, Aifang; Rigaut, Stéphane; Hapiot, Philippe; Lagrost, Corinne

    2009-11-03

    A versatile two-step method is developed to covalently immobilize redox-active molecules onto carbon surfaces. First, a robust anchoring platform is grafted onto surfaces by electrochemical reduction of aryl diazonium salts in situ generated. Depending on the nature of the layer termini, -COOH or -NH(2), a further chemical coupling involving ferrocenemethylamine or ferrocene carboxylic acid derivatives leads to the covalent binding of ferrocene centers. The chemical strategy using acyl chloride activation is efficient and flexible, since it can be applied either to surface-reactive end groups or to reactive species in solution. Cyclic voltammetry analyses point to the covalent binding of ferrocene units restricted to the upper layers of the underlying aryl films, while AFM measurements show a lost of compactness of the layers after the chemical attachment of ferrocene centers. The preparation conditions of the anchoring layers were found to determine the interfacial properties of the resulted ferrocenyl-modified electrodes. The ferrocene units promoted effective redox mediation providing that the free redox probes are adequately chosen (i.e., vs size/formal potential) and the underlying layers exhibit strong blocking properties. For anchoring films with weaker blocking effect, the coexistence of two distinct phenomena, redox mediation and ET at pinholes could be evidenced.

  14. Performance improvement of CdS quantum dots sensitized TiO{sub 2} solar cells by introducing a dense TiO{sub 2} blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Tachibana, Yasuhiro; Umekita, Kazuya; Otsuka, Yasuhide; Kuwabata, Susumu [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Yamada-oka, Suita, Osaka 565-0871 (Japan)], E-mail: y.tachibana@chem.eng.osaka-u.ac.jp

    2008-05-21

    A dense TiO{sub 2} electron blocking layer was introduced on a conducting glass in CdS quantum dots sensitized solar cells to investigate electron leakage into the electrolyte. A ferricyanide/ferrocyanide redox couple was employed, as a model electrolyte, possessing a high standard rate constant. The analysis of the I-V characteristics, using a one-diode model, revealed that an increase in this layer, up to 50 nm, significantly suppresses the electron leakage, enhancing the shunt resistance by a factor of 200. An energy conversion efficiency of 1.0% was attained on account of the improved open circuit voltage and fill factor. (fast track communication)

  15. Superconductivity in REO0.5F0.5BiS2 with high-entropy-alloy-type blocking layers

    Science.gov (United States)

    Sogabe, Ryota; Goto, Yosuke; Mizuguchi, Yoshikazu

    2018-05-01

    We synthesized new REO0.5F0.5BiS2 (RE: rare earth) superconductors with high-entropy-alloy-type (HEA-type) REO blocking layers. The lattice constant a systematically changed in the HEA-type samples with the RE concentration and the RE ionic radius. A sharp superconducting transition was observed in the resistivity measurements for all the HEA-type samples, and the transition temperature of the HEA-type samples was higher than that of typical REO0.5F0.5BiS2. The sharp superconducting transition and the enhanced superconducting properties of the HEA-type samples may indicate the effectiveness of the HEA states of the REO blocking layers in the REO0.5F0.5BiS2 system.

  16. Effect of porcelain polishing addition of waste in properties blocks ceramic; Efeito da adicao do residuo de polimento de porcelanato nas propriedades de blocos ceramicos

    Energy Technology Data Exchange (ETDEWEB)

    Santana, G.L.; Barbosa Neto, M.C.; Campos, L.F.; Macedo, D.A; Dutra, R.P.S., E-mail: geovanalira1@gmail.com [Universidade Federal da Paraiba (UFPB), PB (Brazil)

    2016-07-01

    This work has as objective the study of the technological properties of ceramic blocks with addition of residue porcelain polishing. The test samples are produced with clay base, where the waste is introduced in concentrations of 10% and 20% by mass, to evaluate its influence on the properties of the ceramic block. All these materials were characterized by determining their chemical composition (XRF) and X-ray diffraction Sintering was performed at temperatures of 850 ° C, 950 ° C and 1100 ° C with a heating rate of 2 ° C / me and 60 minutes of landing. After this, there was obtained the technological properties of the samples such as: Loss on fire, the burning linear shrinkage, water absorption, porosity and density, as well as, mechanical strength properties through the flexural strength test. The results show that the addition of waste influenced both the technological properties, the mechanical properties evaluated in this study. (author)

  17. Microstructures of iron aluminides processed by additive layer manufacturing and spark plasma sintering

    Czech Academy of Sciences Publication Activity Database

    Michalcová, A.; Palm, M.; Senceková, L.; Rolink, G.; Weisheit, A.; Kubatík, Tomáš František

    2015-01-01

    Roč. 15, č. 4 (2015), s. 610-614 ISSN 1213-2489 Institutional support: RVO:61389021 Keywords : Intermetallics * Laser additive manufacturing * Powder metal lurgy Subject RIV: JK - Corrosion ; Surface Treatment of Materials

  18. Influence of Weak Base Addition to Hole-Collecting Buffer Layers in Polymer:Fullerene Solar Cells

    Directory of Open Access Journals (Sweden)

    Jooyeok Seo

    2017-02-01

    Full Text Available We report the effect of weak base addition to acidic polymer hole-collecting layers in normal-type polymer:fullerene solar cells. Varying amounts of the weak base aniline (AN were added to solutions of poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate (PEDOT:PSS. The acidity of the aniline-added PEDOT:PSS solutions gradually decreased from pH = 1.74 (AN = 0 mol% to pH = 4.24 (AN = 1.8 mol %. The electrical conductivity of the PEDOT:PSS-AN films did not change much with the pH value, while the ratio of conductivity between out-of-plane and in-plane directions was dependent on the pH of solutions. The highest power conversion efficiency (PCE was obtained at pH = 2.52, even though all devices with the PEDOT:PSS-AN layers exhibited better PCE than those with the pristine PEDOT:PSS layers. Atomic force microscopy investigation revealed that the size of PEDOT:PSS domains became smaller as the pH increased. The stability test for 100 h illumination under one sun condition disclosed that the PCE decay was relatively slower for the devices with the PEDOT:PSS-AN layers than for those with pristine PEDOT:PSS layers.

  19. Increase in transmission loss of single panels by addition of mass inclusions to a poro-elastic layer: Experimental investigation

    Science.gov (United States)

    Kidner, M. R. F.; Fuller, C. R.; Gardner, B.

    2006-06-01

    The insertion loss of standard acoustic blankets can be significantly improved at low frequencies by the addition of randomly placed mass inclusions to the poro-elastic layers. The improvement is much greater than that due to the mass effect alone. The mass inclusions act as resonant systems and so increase the structure impedance. This paper reports the results of experimental investigations into this phenomenon. Increases in insertion loss of 15 dB in the 100 Hz third octave band are reported.

  20. Broadband pH-Sensing Organic Transistors with Polymeric Sensing Layers Featuring Liquid Crystal Microdomains Encapsulated by Di-Block Copolymer Chains.

    Science.gov (United States)

    Seo, Jooyeok; Song, Myeonghun; Jeong, Jaehoon; Nam, Sungho; Heo, Inseok; Park, Soo-Young; Kang, Inn-Kyu; Lee, Joon-Hyung; Kim, Hwajeong; Kim, Youngkyoo

    2016-09-14

    We report broadband pH-sensing organic field-effect transistors (OFETs) with the polymer-dispersed liquid crystal (PDLC) sensing layers. The PDLC layers are prepared by spin-coating using ethanol solutions containing 4-cyano-4'-pentyl-biphenyl (5CB) and a diblock copolymer (PAA-b-PCBOA) that consists of LC-philic block [poly(4-cyano-biphenyl-4-oxyundecyl acrylate) (PCBOA)] and acrylic acid block [poly(acrylic acid) (PAA)]. The spin-coated sensing layers feature of 5CB microdomains (pH with only small amounts (10-40 μL) of analyte solutions in both static and dynamic perfusion modes. The positive drain current change is measured for acidic solutions (pH pH > 7) result in the negative change of drain current. The drain current trend in the present PDLC-i-OFET devices is explained by the shrinking-expanding mechanism of the PAA chains in the diblock copolymer layers.

  1. Effect of Ti additive on (Cr, Fe)7C3 carbide in arc surfacing layer and its refined mechanism

    International Nuclear Information System (INIS)

    Zhou Yefei; Yang Yulin; Yang Jian; Hao Feifei; Li Da; Ren Xuejun; Yang Qingxiang

    2012-01-01

    Arc surfacing layer of hypoeutectic high chromium cast iron (HCCI) expects refiner carbides in the microstructure to improve its mechanical properties. In this paper, Ti additive as a strong carbide forming element was added in the hypoeutectic HCCI arc surfacing layer. Microstructure of titaniferous hypoeutectic HCCI was studied by optical microscopy, X-ray diffraction and field emission scanning electronic microscopy with energy dispersive spectrometer. Furthermore, the M(M = Cr, Fe) 7 C 3 carbide refinement mechanism was explained by the phase diagram calculation and lattice misfit theory. The results show that, the M 7 C 3 carbide in arc surfacing microstructure of hypoeutectic HCCI has been refined with 2 wt.% Ti additive, and TiC carbide can be observed in/around the M 7 C 3 carbide. With Ti addictive increasing, the micro-hardness along the depth in profile section of layer becomes more uniform, and the wear resistance has been improved. According to the phase diagram calculation, MC carbide precipitates prior to M 7 C 3 carbide in Fe-Cr-C-Ti alloy. In addition, the lattice misfit between (1 1 0) TiC and (010) Cr 7 C 3 is 9.257%, which indicates that the TiC as heterogeneous nuclei of the M 7 C 3 is medium effective. Therefore, the M 7 C 3 carbide can be refined.

  2. Cross-Layer Framework for Multiuser Real Time H.264/AVC Video Encoding and Transmission over Block Fading MIMO Channels Using Outage Probability

    Directory of Open Access Journals (Sweden)

    Slavche Pejoski

    2014-01-01

    Full Text Available We present a framework for cross-layer optimized real time multiuser encoding of video using a single layer H.264/AVC and transmission over MIMO wireless channels. In the proposed cross-layer adaptation, the channel of every user is characterized by the probability density function of its channel mutual information and the performance of the H.264/AVC encoder is modeled by a rate distortion model that takes into account the channel errors. These models are used during the resource allocation of the available slots in a TDMA MIMO communication system with capacity achieving channel codes. This framework allows for adaptation to the statistics of the wireless channel and to the available resources in the system and utilization of the multiuser diversity of the transmitted video sequences. We show the effectiveness of the proposed framework for video transmission over Rayleigh MIMO block fading channels, when channel distribution information is available at the transmitter.

  3. Layer-by-Layer Formation of Block-Copolymer-Derived TiO2 for Solid-State Dye-Sensitized Solar Cells

    KAUST Repository

    Guldin, Stefan; Docampo, Pablo; Stefik, Morgan; Kamita, Gen; Wiesner, Ulrich; Snaith, Henry J.; Steiner, Ullrich

    2011-01-01

    Morphology control on the 10 nm length scale in mesoporous TiO 2 films is crucial for the manufacture of high-performance dye-sensitized solar cells. While the combination of block-copolymer self-assembly with sol-gel chemistry yields good results

  4. Effect of the addition of Sm2O3 on the microstructure of laser cladding alloy coating layers

    Science.gov (United States)

    Zhang, Shi Hong; Li, Ming Xi; Cho, Tong Yul; Yoon, Jae Hong; Fang, Wei; Joo, Yun Kon; Kang, Jin Ho; Lee, Chan Gyu

    2008-06-01

    The effects on the microstructures and phases of coating layers by the addition of micron-sized (m) and nano-sized (n) (m&n) Sm2O3 powders were investigated. The coating materials, which were prepared by means of 2.0 kW CO2 laser cladding, consist of a powder mixture of m Ni-based alloy (NBA) powders comprising 1.5 wt.% m Sm2O3 and 3.0% n Sm2O3 powders. The results indicate that γ-Ni, Cr23C6 and Ni3B are the primary phases of the NBA coatings. The Fe7Sm and Ni3Si phases are highlighted by the addition of m&n Sm2O3 powders. From the substrate, planar crystal layers are first grown in all NBA and m&n Sm2O3/NBA coatings. The dendrite growth then occurs as a result of the addition of the m Sm2O3 powder, and the equiaxed dendrite growth occurs as a result of the addition of the n Sm2O3. With the addition of a rare earth oxide such as Sm2O3 powder, the width of the planar crystal becomes smaller than that of the NBA coating.

  5. Poly(Lactic Acid) Hemodialysis Membranes with Poly(Lactic Acid)-block-Poly(2-Hydroxyethyl Methacrylate) Copolymer As Additive: Preparation, Characterization, and Performance.

    Science.gov (United States)

    Zhu, Lijing; Liu, Fu; Yu, Xuemin; Xue, Lixin

    2015-08-19

    Poly(lactic acid) (PLA) hemodialysis membranes with enhanced antifouling capability and hemocompatibility were developed using poly(lactic acid)-block-poly(2-hydroxyethyl methacrylate) (PLA-PHEMA) copolymers as the blending additive. PLA-PHEMA block copolymers were synthesized via reversible addition-fragmentation (RAFT) polymerization from aminolyzed PLA. Gel permeation chromatography (GPC) and (1)H-nuclear magnetic resonance ((1)H NMR) were applied to characterize the synthesized products. By blending PLA with the amphiphilic block copolymer, PLA/PLA-PHEMA membranes were prepared by nonsolvent induced phase separation (NIPS) method. Their chemistry and structure were characterized with X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and atomic force microscopy (AFM). The results revealed that PLA/PLA-PHEMA membranes with high PLA-PHEMA contents exhibited enhanced hydrophilicity, water permeability, antifouling and hemocompatibility. Especially, when the PLA-PHEMA concentration was 15 wt %, the water flux of the modified membrane was about 236 L m(-2) h(-1). Its urea and creatinine clearance was more than 0.70 mL/min, lysozyme clearance was about 0.50 mL/min, BSA clearance was as less as 0.31 mL/min. All the results suggest that PLA-PHEMA copolymers had served as effective agents for optimizing the property of PLA-based membrane for hemodialysis applications.

  6. Substantiation of the Fault-Block Structure for Effective Additional Exploration and Development of the West-Kommunarsky Field

    Directory of Open Access Journals (Sweden)

    M.A. Lobusev

    2017-08-01

    Full Text Available While the seismic exploration and methodological geological interpretation of geological data for drilling various wells and other types of research are improved for a significant part of the fields being developed in the Samara Region, the reliability of the structure of geological and recoverable oil and gas reserves increases. The complication of the structure and multiple recalculations of reserves at a number of fields are due to the introduction into the development of undiscovered to the required conditions of complex geological fields and licensed areas. The example of the West-Kommunarsky field shows how its geological structure becomes more complex as its study becomes more extensive. Thus, the oil reservoir in the Lower Paschian sediments, according to the created integrated model, has horizontal positions, but with different levels of water-oil contact in adjacent blocks separated by downthrows. The justification of disjunctive dislocations, which have been planned but not tracked due to their uncertainty in seismic data and determination of their main characteristics, was performed by stratigraphic correlation of well sections using the rules of projective geometry and confirmed by other traditional methodical methods. With each new tectonic movement along the strike-slip, a near-faul fracture of rocks is formed parallel to it, as a reflection of geodynamic stresses and energy-intensive processes in the downthrows and strike-slips of rocks along the fault plane. Near-fault regular changes in the fracturing of rocks and the dependence of well productivity on their location relative to the disjunctive make it possible to predict the latitudinal reservoirs zonation in near-fault area: fractured, porous-fractured, fractured-porous and porous types. Such a dialectical process of movement towards a real model of the field ensures the reliability of revised reserves and updated technological documents for the development of fields.

  7. Hierarchical random additive process and logarithmic scaling of generalized high order, two-point correlations in turbulent boundary layer flow

    Science.gov (United States)

    Yang, X. I. A.; Marusic, I.; Meneveau, C.

    2016-06-01

    Townsend [Townsend, The Structure of Turbulent Shear Flow (Cambridge University Press, Cambridge, UK, 1976)] hypothesized that the logarithmic region in high-Reynolds-number wall-bounded flows consists of space-filling, self-similar attached eddies. Invoking this hypothesis, we express streamwise velocity fluctuations in the inertial layer in high-Reynolds-number wall-bounded flows as a hierarchical random additive process (HRAP): uz+=∑i=1Nzai . Here u is the streamwise velocity fluctuation, + indicates normalization in wall units, z is the wall normal distance, and ai's are independently, identically distributed random additives, each of which is associated with an attached eddy in the wall-attached hierarchy. The number of random additives is Nz˜ln(δ /z ) where δ is the boundary layer thickness and ln is natural log. Due to its simplified structure, such a process leads to predictions of the scaling behaviors for various turbulence statistics in the logarithmic layer. Besides reproducing known logarithmic scaling of moments, structure functions, and correlation function [" close="]3/2 uz(x ) uz(x +r ) >, new logarithmic laws in two-point statistics such as uz4(x ) > 1 /2, 1/3, etc. can be derived using the HRAP formalism. Supporting empirical evidence for the logarithmic scaling in such statistics is found from the Melbourne High Reynolds Number Boundary Layer Wind Tunnel measurements. We also show that, at high Reynolds numbers, the above mentioned new logarithmic laws can be derived by assuming the arrival of an attached eddy at a generic point in the flow field to be a Poisson process [Woodcock and Marusic, Phys. Fluids 27, 015104 (2015), 10.1063/1.4905301]. Taken together, the results provide new evidence supporting the essential ingredients of the attached eddy hypothesis to describe streamwise velocity fluctuations of large, momentum transporting eddies in wall-bounded turbulence, while observed deviations suggest the need for further extensions of the

  8. A tribo-mechanical analysis of PVA-based building-blocks for implementation in a 2-layered skin model

    NARCIS (Netherlands)

    Morales Hurtado, Marina; de Vries, Erik G.; Zeng, Xiangqiong; van der Heide, Emile

    2016-01-01

    Poly(vinyl) alcohol hydrogel (PVA) is a well-known polymer widely used in the medical field due to its biocompatibility properties and easy manufacturing. In this work, the tribo-mechanical properties of PVA-based blocks are studied to evaluate their suitability as a part of a structure simulating

  9. A Comparative Study of Additively Manufactured Thin Wall and Block Structure with Al-6.3%Cu Alloy Using Cold Metal Transfer Process

    Directory of Open Access Journals (Sweden)

    Baoqiang Cong

    2017-03-01

    Full Text Available In order to build a better understanding of the relationship between depositing mode and porosity, microstructure, and properties in wire + arc additive manufacturing (WAAM 2319-Al components, several Al-6.3%Cu deposits were produced by WAAM technique with cold metal transfer (CMT variants, pulsed CMT (CMT-P and advanced CMT (CMT-ADV. Thin walls and blocks were selected as the depositing paths to make WAAM samples. Porosity, microstructure and micro hardness of these WAAM samples were investigated. Compared with CMT-P and thin wall mode, CMT-ADV and block process can effectively reduce the pores in WAAM aluminum alloy. The microstructure varied with different depositing paths and CMT variants. The micro hardness value of thin wall samples was around 75 HV from the bottom to the middle, and gradually decreased toward the top. Meanwhile, the micro hardness value ranged around 72–77 HV, and varied periodically in block samples. The variation in micro hardness is consistent with standard microstructure characteristics.

  10. Enantioselective ProPhenol-catalyzed addition of 1,3-diynes to aldehydes to generate synthetically versatile building blocks and diyne natural products.

    Science.gov (United States)

    Trost, Barry M; Chan, Vincent S; Yamamoto, Daisuke

    2010-04-14

    A highly enantioselective method for the catalytic addition of terminal 1,3-diynes to aldehydes was developed using our dinuclear zinc ProPhenol (1) system. Furthermore, triphenylphosphine oxide was found to interact synergistically with the catalyst to substantially enhance the chiral recognition. The generality of this catalytic transformation was demonstrated with aryl, alpha,beta-unsaturated and saturated aldehydes, of which the latter were previously limited in alkynyl zinc additions. The chiral diynol products are also versatile building blocks that can be readily elaborated; this was illustrated through highly selective trans-hydrosilylations, which enabled the synthesis of a beta-hydroxyketone and enyne. Additionally, the development of this method allowed for the rapid total syntheses of several biologically important diynol-containing natural products.

  11. Microstructure and thermal stability of nickel layers electrodeposited from an additive-free sulphamate-based electrolyte

    DEFF Research Database (Denmark)

    Rasmussen, Anette Alsted; Møller, Per; Somers, Marcel A. J.

    2006-01-01

    and scanning electron microscopy and X-ray diffraction; the Vickers hardness was measured in cross sections. The present is meant as a reference for forthcoming articles on the investigation of various strengthening mechanisms on the microstructure, hardness and thermal stability of Ni (alloys) electrodeposits.......The influences of the current density and the temperature on the microstructure and hardness of Ni layers electrodeposited from an additive-free sulphamate bath were investigated. The microstructure and thermal stability of the electrodeposits was investigated with a combination of transmission...

  12. High breakdown voltage in AlGaN/GaN HEMTs using AlGaN/GaN/AlGaN quantum-well electron-blocking layers.

    Science.gov (United States)

    Lee, Ya-Ju; Yao, Yung-Chi; Huang, Chun-Ying; Lin, Tai-Yuan; Cheng, Li-Lien; Liu, Ching-Yun; Wang, Mei-Tan; Hwang, Jung-Min

    2014-01-01

    In this paper, we numerically study an enhancement of breakdown voltage in AlGaN/GaN high-electron-mobility transistors (HEMTs) by using the AlGaN/GaN/AlGaN quantum-well (QW) electron-blocking layer (EBL) structure. This concept is based on the superior confinement of two-dimensional electron gases (2-DEGs) provided by the QW EBL, resulting in a significant improvement of breakdown voltage and a remarkable suppression of spilling electrons. The electron mobility of 2-DEG is hence enhanced as well. The dependence of thickness and composition of QW EBL on the device breakdown is also evaluated and discussed.

  13. Effect of location on microstructure and mechanical properties of additive layer manufactured Inconel 625 using gas tungsten arc welding

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.F. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Sun, Q.J., E-mail: qjsun@hit.edu.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Wang, H. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Liu, J.P. [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); China Nuclear Industry 23 Construction Co., Ltd., Beijing 101300 (China); Feng, J.C. [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China)

    2016-10-31

    Additive layer manufacturing (ALM), using gas tungsten arc welding (GTAW) as heat source, is a promising technology in producing Inconel 625 components due to significant cost savings, high deposition rate and convenience of processing. With the purpose of revealing how microstructure and mechanical properties are affected by the location within the manufactured wall component, the present study has been carried out. The manufactured Inconel 625 consists of cellular grains without secondary dendrites in the near-substrate region, columnar dendrites structure oriented upwards in the layer bands, followed by the transition from directional dendrites to equiaxed grain in the top region. With the increase in deposited height, segregation behavior of alloying elements Nb and Mo constantly strengthens with maximal evolution in the top region. The primary dendrite arm spacing has a well coherence with the content of Laves phase. The microhardness and tensile strength show obvious variation in different regions. The microhardness and tensile strength of near-substrate region are superior to that of layer bands and top region. The results are further explained in detail through the weld pool behavior and temperature field measurement.

  14. Effect of location on microstructure and mechanical properties of additive layer manufactured Inconel 625 using gas tungsten arc welding

    International Nuclear Information System (INIS)

    Wang, J.F.; Sun, Q.J.; Wang, H.; Liu, J.P.; Feng, J.C.

    2016-01-01

    Additive layer manufacturing (ALM), using gas tungsten arc welding (GTAW) as heat source, is a promising technology in producing Inconel 625 components due to significant cost savings, high deposition rate and convenience of processing. With the purpose of revealing how microstructure and mechanical properties are affected by the location within the manufactured wall component, the present study has been carried out. The manufactured Inconel 625 consists of cellular grains without secondary dendrites in the near-substrate region, columnar dendrites structure oriented upwards in the layer bands, followed by the transition from directional dendrites to equiaxed grain in the top region. With the increase in deposited height, segregation behavior of alloying elements Nb and Mo constantly strengthens with maximal evolution in the top region. The primary dendrite arm spacing has a well coherence with the content of Laves phase. The microhardness and tensile strength show obvious variation in different regions. The microhardness and tensile strength of near-substrate region are superior to that of layer bands and top region. The results are further explained in detail through the weld pool behavior and temperature field measurement.

  15. Adductor canal block for post-operative analgesia after simultaneous bilateral total knee replacement: A randomised controlled trial to study the effect of addition of dexmedetomidine to ropivacaine

    Directory of Open Access Journals (Sweden)

    Rakhee Goyal

    2017-01-01

    Full Text Available Background and Aims: Knee replacement surgery causes tremendous post-operative pain and adductor canal block (ACB is used for post-operative analgesia. This is a randomised, controlled, three-arm parallel group study using different doses of dexmedetomidine added to ropiavcaine for ACB. Methods: A total of 150 patients aged 18–75 years, scheduled for simultaneous bilateral total knee replacement, received ultrasound-guided ACB. They were randomised into three groups -Group A received ACB with plain ropivacaine; Groups B and C received ACB with ropivacaine and addition of dexmedetomidine 0.25 μg/kg and 0.50 μg/kg, respectively, on each side of ACB. The primary outcome was the duration of analgesia. Total opioid consumption, success of early ambulation, and level of patient satisfaction were also assessed. Results: The patient characteristics and block success rates were comparable in all groups. Group C patients had longer duration of analgesia (Group C 18.4 h ± 7.4; Group B 14.6 ± 7.1; Group A 10.8 ± 7; P < 0.001; lesser tramadol consumption (Group C 43.8 mg ± 53.2; Group B 76.4 ± 49.6; Group A 93.9 mg ± 58.3; P < 0.001 and lesser pain on movement (P < 0.001. The patients in Group B and C walked more steps than in Group A (P < 0.002. The level of patient satisfaction was highest in Group C (P < 0.001. Conclusions: The addition of dexmedetomidine to ropivacaine resulted in longer duration of analgesia after adductor canal block for simultaneous bilateral total knee replacement surgery.

  16. Building blocks for the development of an interface for high-throughput thin layer chromatography/ambient mass spectrometric analysis: a green methodology.

    Science.gov (United States)

    Cheng, Sy-Chyi; Huang, Min-Zong; Wu, Li-Chieh; Chou, Chih-Chiang; Cheng, Chu-Nian; Jhang, Siou-Sian; Shiea, Jentaie

    2012-07-17

    Interfacing thin layer chromatography (TLC) with ambient mass spectrometry (AMS) has been an important area of analytical chemistry because of its capability to rapidly separate and characterize the chemical compounds. In this study, we have developed a high-throughput TLC-AMS system using building blocks to deal, deliver, and collect the TLC plate through an electrospray-assisted laser desorption ionization (ELDI) source. This is the first demonstration of the use of building blocks to construct and test the TLC-MS interfacing system. With the advantages of being readily available, cheap, reusable, and extremely easy to modify without consuming any material or reagent, the use of building blocks to develop the TLC-AMS interface is undoubtedly a green methodology. The TLC plate delivery system consists of a storage box, plate dealing component, conveyer, light sensor, and plate collecting box. During a TLC-AMS analysis, the TLC plate was sent to the conveyer from a stack of TLC plates placed in the storage box. As the TLC plate passed through the ELDI source, the chemical compounds separated on the plate would be desorbed by laser desorption and subsequently postionized by electrospray ionization. The samples, including a mixture of synthetic dyes and extracts of pharmaceutical drugs, were analyzed to demonstrate the capability of this TLC-ELDI/MS system for high-throughput analysis.

  17. Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells.

    Science.gov (United States)

    Krýsová, Hana; Krýsa, Josef; Kavan, Ladislav

    2018-01-01

    For proper function of the negative electrode of dye-sensitized and perovskite solar cells, the deposition of a nonporous blocking film is required on the surface of F-doped SnO 2 (FTO) glass substrates. Such a blocking film can minimise undesirable parasitic processes, for example, the back reaction of photoinjected electrons with the oxidized form of the redox mediator or with the hole-transporting medium can be avoided. In the present work, thin, transparent, blocking TiO 2 films are prepared by semi-automatic spray pyrolysis of precursors consisting of titanium diisopropoxide bis(acetylacetonate) as the main component. The variation in the layer thickness of the sprayed films is achieved by varying the number of spray cycles. The parameters investigated in this work were deposition temperature (150, 300 and 450 °C), number of spray cycles (20-200), precursor composition (with/without deliberately added acetylacetone), concentration (0.05 and 0.2 M) and subsequent post-calcination at 500 °C. The photo-electrochemical properties were evaluated in aqueous electrolyte solution under UV irradiation. The blocking properties were tested by cyclic voltammetry with a model redox probe with a simple one-electron-transfer reaction. Semi-automatic spraying resulted in the formation of transparent, homogeneous, TiO 2 films, and the technique allows for easy upscaling to large electrode areas. The deposition temperature of 450 °C was necessary for the fabrication of highly photoactive TiO 2 films. The blocking properties of the as-deposited TiO 2 films (at 450 °C) were impaired by post-calcination at 500 °C, but this problem could be addressed by increasing the number of spray cycles. The modification of the precursor by adding acetylacetone resulted in the fabrication of TiO 2 films exhibiting perfect blocking properties that were not influenced by post-calcination. These results will surely find use in the fabrication of large-scale dye-sensitized and perovskite solar

  18. Improvement of inverted organic solar cells using acetic acid as an additive for ZnO layer processing

    Directory of Open Access Journals (Sweden)

    Yang Li

    2018-02-01

    Full Text Available In this work, we used acetic acid as an additive for the preparation of ZnO layers and improved the performance of poly{4,8-bis[(2-ethylhexyl-oxy]benzo[1,2-b:4,5-b’] dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexylcarbonyl]thieno[3,4-b]thiophene- 4,6-diyl} (PTB7-based inverted organic solar cells. The addition of acetic acid to the ZnO precursor solution improved the transparency and conductivity of the sol-gel-synthesized ZnO film, by increasing the grain size of the film. Accordingly, the power conversion efficiency (PCE of the organic solar cells was improved from 6.42% to 7.55%, which was mainly caused by the enhanced current density and fill factor. The best sample demonstrated a high PCE of 7.85% with negligible hysteresis and good stability. Our results indicate that using acetic acid as an additive for the preparation of ZnO is a simple and effective way of fabricating high-performance inverted organic solar cells.

  19. Improvement of inverted organic solar cells using acetic acid as an additive for ZnO layer processing

    Science.gov (United States)

    Li, Yang; Liu, Yawen; Liu, Zhihai; Xie, Xiaoyin; Lee, Eun-Cheol

    2018-02-01

    In this work, we used acetic acid as an additive for the preparation of ZnO layers and improved the performance of poly{4,8-bis[(2-ethylhexyl)-oxy]benzo[1,2-b:4,5-b'] dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophene- 4,6-diyl} (PTB7)-based inverted organic solar cells. The addition of acetic acid to the ZnO precursor solution improved the transparency and conductivity of the sol-gel-synthesized ZnO film, by increasing the grain size of the film. Accordingly, the power conversion efficiency (PCE) of the organic solar cells was improved from 6.42% to 7.55%, which was mainly caused by the enhanced current density and fill factor. The best sample demonstrated a high PCE of 7.85% with negligible hysteresis and good stability. Our results indicate that using acetic acid as an additive for the preparation of ZnO is a simple and effective way of fabricating high-performance inverted organic solar cells.

  20. In patients undergoing fast track total knee arthroplasty, addition of buprenorphine to a femoral nerve block has no clinical advantage A prospective, double-blinded, randomized, placebo controlled trial

    NARCIS (Netherlands)

    van Beek, Rienk; Zonneveldt, Harry J.; van der Ploeg, Tjeerd; Steens, Jeroen; Lirk, Phillip; Hollmann, Marcus W.

    2017-01-01

    Background: Several adjuvants have been proposed to prolong the effect of peripheral nerve blocks, one of which is buprenorphine. In this randomized double blinded placebo controlled trial we studied whether the addition of buprenorphine to a femoral nerve block prolongs analgesia in patients

  1. Non-surface activity and micellization behavior of cationic amphiphilic block copolymer synthesized by reversible addition-fragmentation chain transfer process.

    Science.gov (United States)

    Ghosh, Arjun; Yusa, Shin-ichi; Matsuoka, Hideki; Saruwatari, Yoshiyuki

    2011-08-02

    Cationic amphiphilic diblock copolymers of poly(n-butylacrylate)-b-poly(3-(methacryloylamino)propyl)trimethylammonium chloride) (PBA-b-PMAPTAC) with various hydrophobic and hydrophilic chain lengths were synthesized by a reversible addition-fragmentation chain transfer (RAFT) process. Their molecular characteristics such as surface activity/nonactivity were investigated by surface tension measurements and foam formation observation. Their micelle formation behavior and micelle structure were investigated by fluorescence probe technique, static and dynamic light scattering (SLS and DLS), etc., as a function of hydrophilic and hydrophobic chain lengths. The block copolymers were found to be non-surface active because the surface tension of the aqueous solutions did not change with increasing polymer concentration. Critical micelle concentration (cmc) of the polymers could be determined by fluorescence and SLS measurements, which means that these polymers form micelles in bulk solution, although they were non-surface active. Above the cmc, the large blue shift of the emission maximum of N-phenyl-1-naphthylamine (NPN) probe and the low micropolarity value of the pyrene probe in polymer solution indicate the core of the micelle is nonpolar in nature. Also, the high value of the relative intensity of the NPN probe and the fluorescence anisotropy of the 1,6-diphenyl-1,3,5-hexatriene (DPH) probe indicated that the core of the micelle is highly viscous in nature. DLS was used to measure the average hydrodynamic radii and size distribution of the copolymer micelles. The copolymer with the longest PBA block had the poorest water solubility and consequently formed micelles with larger size while having a lower cmc. The "non-surface activity" was confirmed for cationic amphiphilic diblock copolymers in addition to anionic ones studied previously, indicating the universality of non-surface activity nature.

  2. Compound La[B5O8(OH)2] with a new type of pentaborate layer based on the 5[3T + 2Δ] block: Topology-symmetry analysis and the position in the structural system

    International Nuclear Information System (INIS)

    Ivanova, A. G.; Belokoneva, E. L.; Dimitrova, O. V.; Mochenova, N. N.

    2006-01-01

    Crystals of a new rare-earth borate, LaB 5 O 8 (OH) 2 (space group P2 1 /n), are synthesized under hydrothermal conditions. The crystal structure is determined by the heavy-atom method without prior knowledge of the chemical formula. The radical anion is a layer composed of pentaborate blocks 5[3T + 2Δ]. The topological and symmetric patterns of their condensation differ from those observed in all known layered pentaborates containing the same block. The building blocks are shared by vertices of tetrahedra to form chains. These chains are joined into a corrugated layer in such a way that one of the BO 3 triangles of the building block is terminal and the layer itself is denser than those previously revealed in all other borates. In contrast to the majority of layer borates, the new La borate does not contain water molecules, because it crystallizes from more concentrated solutions. The La atoms are located inside the walls of the hollows of corrugated layers, thus centering the holes of the layers

  3. Multi-layer concept for containments in an integrated construction method by using steel composite building block modules

    International Nuclear Information System (INIS)

    Friedrich, F.

    1987-01-01

    Containments consisting of steel modules have been developed as an alternative design and solution to the double shell containments comprising two separate structures. The combination of different reinforcement layers of steel plates and round reinforcing bars in one cross section provides a high loadbearing capacity. The multiple utilization of the steel plates in the composite section as formwork in the construction state and as reinforcement and liner in the operation or damage/failure states, respectively, yields a number of advantages. The main effect is being achieved due to the high degree of prefabrication and completion (finishing) of the steel modules and the reduction of expenditure on the job site connected with same. (orig.)

  4. Tris(trimethylsilyl)phosphate as electrolyte additive for self-discharge suppression of layered nickel cobalt manganese oxide

    International Nuclear Information System (INIS)

    Liao, Xiaolin; Zheng, Xiongwen; Chen, Jiawei; Huang, Ziyu; Xu, Mengqing; Xing, Lidan; Liao, Youhao; Lu, Qilun; Li, Xiangfeng; Li, Weishan

    2016-01-01

    Highlights: • TMSP is effective for self-discharge suppression of the charged NCM under 4.5 V. • TMSP oxidizes preferentially forming protective cathode interface film on NCM. • The film suppresses electrolyte decomposition and prevents NCM destruction. - Abstract: Application of layered nickel cobalt manganese oxide as cathode under higher potential than conventional 4.2 V yields a significant improvement in energy density of lithium ion battery. However, the cathode fully charged under high potential suffers serious self-discharge, in which the interaction between the cathode and electrolyte proceeds without potential limitation. In this work, we use tris(trimethylsilyl)phosphate (TMSP) as an electrolyte additive to solve this problem. A representative layered nickel cobalt manganese oxide, LiNi 1/3 Co 1/3 Mn 1/3 O 2 , is considered. The effect of TMSP on self-discharge behavior of LiNi 1/3 Co 1/3 Mn 1/3 O 2 is evaluated by physical and electrochemical methods. It is found that the self-discharge of charged LiNi 1/3 Co 1/3 Mn 1/3 O 2 can be suppressed significantly by using TMSP. TMSP is oxidized preferentially in comparison with the standard electrolyte during initial charging process forming a protective cathode interface film, which avoids the interaction between cathode and electrolyte at any potential and thus prevents electrolyte decomposition and protects LiNi 1/3 Co 1/3 Mn 1/3 O 2 from structure destruction.

  5. Design and development of a layer-based additive manufacturing process for the realization of metal parts of designed mesostructure

    Science.gov (United States)

    Williams, Christopher Bryant

    Low-density cellular materials, metallic bodies with gaseous voids, are a unique class of materials that are characterized by their high strength, low mass, good energy absorption characteristics, and good thermal and acoustic insulation properties. In an effort to take advantage of this entire suite of positive mechanical traits, designers are tailoring the cellular mesostructure for multiple design objectives. Unfortunately, existing cellular material manufacturing technologies limit the design space as they are limited to certain part mesostructure, material type, and macrostructure. The opportunity that exists to improve the design of existing products, and the ability to reap the benefits of cellular materials in new applications is the driving force behind this research. As such, the primary research goal of this work is to design, embody, and analyze a manufacturing process that provides a designer the ability to specify the material type, material composition, void morphology, and mesostructure topology for any conceivable part geometry. The accomplishment of this goal is achieved in three phases of research: (1) Design---Following a systematic design process and a rigorous selection exercise, a layer-based additive manufacturing process is designed that is capable of meeting the unique requirements of fabricating cellular material geometry. Specifically, metal parts of designed mesostructure are fabricated via three-dimensional printing of metal oxide ceramic powder followed by post-processing in a reducing atmosphere. (2) Embodiment ---The primary research hypothesis is verified through the use of the designed manufacturing process chain to successfully realize metal parts of designed mesostructure. (3) Modeling & Evaluation ---The designed manufacturing process is modeled in this final research phase so as to increase understanding of experimental results and to establish a foundation for future analytical modeling research. In addition to an analysis of

  6. Nerve Blocks

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Nerve Blocks A nerve block is an injection to ... the limitations of Nerve Block? What is a Nerve Block? A nerve block is an anesthetic and/ ...

  7. Improved light emission from n-ZnO/p-Si heterojunction with HfO{sub 2} as an electron blocking layer

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhao; Li, Borui [Key Lab of Artificial Micro- and Nano- structures of Ministry of Education of China, Department of Electronic Science and Technology, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Mo, Xiaoming [School of Physical Science and Technology, Guangxi University, Nanning, Guangxi 530004 (China); Zhou, Kai [Key Lab of Artificial Micro- and Nano- structures of Ministry of Education of China, Department of Electronic Science and Technology, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Li, Songzhan [School of Electronic and Electrical Engineering, Wuhan Textile University, Wuhan 430073 (China); Song, Zengcai; Lei, Hongwei; Wen, Jian; Zhu, Ziqiang [Key Lab of Artificial Micro- and Nano- structures of Ministry of Education of China, Department of Electronic Science and Technology, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Fang, Guojia, E-mail: gjfang@whu.edu.cn [Key Lab of Artificial Micro- and Nano- structures of Ministry of Education of China, Department of Electronic Science and Technology, School of Physics and Technology, Wuhan University, Wuhan 430072 (China)

    2017-04-15

    Light-emitting diodes (LEDs) based on ZnO were fabricated on a p-Si substrate by using a pulsed laser deposition system. Significant electroluminescence (EL) improvement was demonstrated with the insertion of an HfO{sub 2} electron blocking layer (EBL) in n-ZnO/p-Si heterojunctions. Distinct near-band-edge emission at around 392 nm accompanying by a broadly strong visible emission was achieved when a proper thickness of HfO{sub 2} EBL was used. Current-voltage and capacitance-voltage measurements confirmed that a proper thickness of the HfO{sub 2} EBL can effectively balance the injection of electrons and holes, resulting in an increase of radiative recombination in the ZnO active layer and thus enhancing the EL performance of the devices. Five independent emissions corresponding to five different transition processes were proposed to clarify the EL origination of the n-ZnO/HfO{sub 2}/p-Si heterojunction LEDs by Gaussian deconvolutions. It is hoped that results in this work should be helpful for the development of ZnO-based LEDs that can integrate ZnO with the Si planar technology.

  8. Microstructure and thermoelectric properties of screen-printed thick-films of misfit-layered cobalt oxides with Ag addition

    DEFF Research Database (Denmark)

    Van Nong, Ngo; Samson, Alfred Junio; Pryds, Nini

    2012-01-01

    Thermoelectric properties of thick (~60 μm) films prepared by a screen-printing technique using p-type misfit-layered cobalt oxide Ca3Co4O9+δ with Ag addition have been studied. The screen-printed films were sintered in air at various temperatures ranging from 973 K to 1223 K. After each sintering...... process, crystal and microstructure analyses were carried out to determine the optimal sintering condition. The results show that the thermoelectric properties of pure Ca3Co4O9+δ thick film are comparable to those of cold isostatic pressing (CIP) samples. We found that the maximum power factor...... was improved by about 67% (to 0.3 mW/m K2) for film with proper silver (Ag) metallic inclusions as compared with 0.18 mW/m K2 for pure Ca3Co4O9+δ film under the same sintering condition of 1223 K for 2 h in air....

  9. Electrodeposition of Fe{sub 3}O{sub 4} layer from solution of Fe{sub 2}(SO{sub 4}){sub 3} with addition ethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Dahlan, Dahyunir, E-mail: dahyunir@yahoo.com; Asrar, Allan [Department of Physics, Andalas University, Limau Manih Padang 25163, West Sumatera (Indonesia)

    2016-03-11

    The electrodeposition of Fe{sub 3}O{sub 4} layer from the solution Fe{sub 2}(SO{sub 4}){sub 3} with the addition of ethylene glycol on Indium Tin Oxide (ITO) substrate has been performed. The electrodeposition was carried out using a voltage of 5 volts for 120 seconds, with and without the addition of 2% wt ethylene glycol. Significant effects of temperature on the resulting the samples is observed when they are heated at 400 °C. Structural characterization using X-ray diffraction (XRD) shows that all samples produce a layer of Fe{sub 3}O{sub 4} with particle size less than 50 nanometers. The addition of ethylene glycol and the heating of the sample causes a shrinkage in particle size. The scanning electron microscopy (SEM) characterization shows that Fe{sub 3}O{sub 4} layer resulting from the process of electrodeposition of Fe{sub 2}(SO{sub 4}){sub 3} without ethylene glycol, independent of whether the sample is heated or not, is uneven and buildup. Layer produced by the addition of ethylene glycol without heating produces spherical particles. On contrary, when the layer is heated the spherical particles transform to irregularly-shaped particles with smaller size.

  10. Internal reforming of methane in a mono-block-layer build solid oxide fuel cell with an embedding porous pipe: Numerical analysis

    International Nuclear Information System (INIS)

    Ramírez-Minguela, J.J.; Mendoza-Miranda, J.M.; Muñoz-Carpio, V.D.; Rangel-Hernández, V.H.; Pérez-García, V.; Rodríguez-Muñoz, J.L.

    2014-01-01

    Highlights: • A MOLB-type SOFC with different biogas compositions is modeled. • Internal reforming of methane and water gas shift in the anode side are considered. • Changes in the SOFC according to the phenomena inside of them are assessed. • A new configuration for the MOLB-type geometry is proposed. • Temperature gradients effects in the new configuration are significant. - Abstract: A mono-block-layer build type (MOLB-type) geometry, composed with trapezoidal cross-section channels for fuel and air, of solid oxide fuel cell (SOFC), is modeled in this study using a three dimensional computational fluid dynamics (CFD). The model is used to obtain the performance of the SOFC considering internal reforming of methane in the anode side with different biogas compositions. From the results obtained, a new configuration for the MOLB-type geometry is proposed. The model takes into account the mass transfer, heat transfer, species transport, chemical and electrochemical reactions, detailed comparisons of species concentration, temperature and electric fields inside the cell analyzed in the present study. Results show that the biogas from local sludge has the lower temperature gradient and more homogeneous current density distributions along of the fuel cell, on the other hand, with the new configuration proposed for the MOLB-type geometry the temperature distribution inside of the fuel cell has lower temperature gradients

  11. Study on characteristics of a double-conductible channel organic thin-film transistor with an ultra-thin hole-blocking layer

    International Nuclear Information System (INIS)

    Guang-Cai, Yuan; Zheng, Xu; Su-Ling, Zhao; Fu-Jun, Zhang; Xue-Yan, Tian; Xu-Rong, Xu; Na, Xu

    2009-01-01

    The properties of top-contact organic thin-film transistors (TC-OTFTs) using ultra-thin 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline (BCP) as a hole-blocking interlayer have been improved significantly and a BCP interlayer was inserted into the middle of the pentacene active layer. This paper obtains a fire-new transport mode of an OTFT device with double-conductible channels. The accumulation and transfer of the hole carriers are limited by the BCP interlayer in the vertical region of the channel. A huge amount of carriers is located not only at the interface between pentacene and the gate insulator, but also at the two interfaces of pentacene/BCP interlayer and pentacene/gate insulator, respectively. The results suggest that the BCP interlayer may be useful to adjust the hole accumulation and transfer, and can increase the hole mobility and output current of OTFTs. The TC-OTFTs with a BCP interlayer at V DS = −20 V showed excellent hole mobility μFE and threshold voltage V TH of 0.58 cm 2 /(V·s) and −4.6 V, respectively

  12. Effect of additive gases and injection methods on chemical dry etching of silicon nitride, silicon oxynitride, and silicon oxide layers in F2 remote plasmas

    International Nuclear Information System (INIS)

    Yun, Y. B.; Park, S. M.; Kim, D. J.; Lee, N.-E.; Kim, K. S.; Bae, G. H.

    2007-01-01

    The authors investigated the effects of various additive gases and different injection methods on the chemical dry etching of silicon nitride, silicon oxynitride, and silicon oxide layers in F 2 remote plasmas. N 2 and N 2 +O 2 gases in the F 2 /Ar/N 2 and F 2 /Ar/N 2 /O 2 remote plasmas effectively increased the etch rate of the layers. The addition of direct-injected NO gas increased the etch rates most significantly. NO radicals generated by the addition of N 2 and N 2 +O 2 or direct-injected NO molecules contributed to the effective removal of nitrogen and oxygen in the silicon nitride and oxide layers, by forming N 2 O and NO 2 by-products, respectively, and thereby enhancing SiF 4 formation. As a result of the effective removal of the oxygen, nitrogen, and silicon atoms in the layers, the chemical dry etch rates were enhanced significantly. The process regime for the etch rate enhancement of the layers was extended at elevated temperature

  13. Addition of Liposome Bupivacaine to Bupivacaine HCl Versus Bupivacaine HCl Alone for Interscalene Brachial Plexus Block in Patients Having Major Shoulder Surgery

    NARCIS (Netherlands)

    Vandepitte, C.; Kuroda, M.; Witvrouw, R.; Anne, L.; Bellemans, J.; Corten, K.; Vanelderen, P.J.; Mesotten, D.; Leunen, I.; Heylen, M.; Boxstael, S. Van; Golebiewski, M.; Velde, M. van de; Knezevic, N.N.; Hadzic, A.

    2017-01-01

    BACKGROUND AND OBJECTIVES: We examined whether liposome bupivacaine (Exparel) given in the interscalene brachial plexus block lowers pain in the setting of multimodal postoperative pain management for major shoulder surgery. METHODS: Fifty-two adult patients were randomized to receive either 5 mL of

  14. Controlled radical copolymerization of styrene and maleic anhydride and the synthesis of novel polyolefin-based block copolymers by reversible addition-fragmentation chain-transfer (RAFT) polymerization

    NARCIS (Netherlands)

    Brouwer, de J.A.M.; Schellekens, M.A.J.; Klumperman, B.; Monteiro, M.J.; German, A.L.

    2000-01-01

    Reversible addn.-fragmentation chain transfer (RAFT) was applied to the copolymn. of styrene and maleic anhydride. The product had a low polydispersity and a predetd. molar mass. Novel, well-defined polyolefin-based block copolymers were prepd. with a macromol. RAFT agent prepd. from a com.

  15. About the effect of melted zinc mass additives on the formation on layers during hot galvanizing; Zur Wirkung von Zusaetzen zur Zinkschmelze auf die Schichtbildung beim Feuerverzinken

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, P.; Schulz, W.D. [Institut fuer Korrosionsschutz Dresden GmbH, Gostritzer Str. 61-63, D-01217 Dresden (Germany)

    2002-09-01

    The influence of various melted zinc mass additives on the galvanizing behaviour of steels is examined by way of comparison. The mechanisms influencing the formation of layers are very different. In case tin is added, a material barrier of enriched tin develops in the zinc coating, which inhibits the iron transport. The mechanisms of Ni, Ti and Al in the melted zinc mass are explained by means of a new theory on the formation of layers, which is based on the influence of the growth of layers via hydrogen escaping from the steel surface during hot galvanizing. This behaviour makes it clear why the single melted mass additives only have a layer-thickness reducing effect on steels with very definite Si contents. The different inhibitions of the growth of the layer during hot galvanizing are discussed. (Abstract Copyright[2002], Wiley Periodicals, Inc.) [German] Der Einfluss unterschiedlicher Zinkschmelzezusaetze auf das Verzinkungsverhalten der Staehle wird vergleichend untersucht. Die Mechanismen der Einflussnahme auf die Schichtbildung sind sehr unterschiedlich. Bei Zusatz von Zinn entsteht im Zinkueberzug eine Materialbarriere aus angereichertem Zinn, die den Eisentransport hemmt. Die Wirkungsweise von Ni, Ti und Al in der Zinkschmelze wird mit Hilfe einer neuen Theorie der Schichtbildung erklaert. Diese beruht auf der Beeinflussung des Schichtwachstums durch Wasserstoff, der waehrend des Feuerverzinkens aus der Stahloberflaeche austritt. Diese Erklaerung macht verstaendlich, warum die einzelnen Schmelzezusaetze nur bei Staehlen mit ganz bestimmten Si-Gehalten schichtdickenreduzierend wirken. Die unterschiedlichen Hemmungen des Schichtwachstums beim Feuerverzinken werden diskutiert. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

  16. Effect of Nonionic Surfactant Additive in PEDOT:PSS on PFO Emission Layer in Organic-Inorganic Hybrid Light-Emitting Diode.

    Science.gov (United States)

    Cho, Seong Rae; Porte, Yoann; Kim, Yun Cheol; Myoung, Jae-Min

    2018-03-21

    Poly(9,9-dioctylfluorene) (PFO) has attracted significant interests owing to its versatility in electronic devices. However, changes in its optical properties caused by its various phases and the formation of oxidation defects limit the application of PFO in light-emitting diodes (LEDs). We investigated the effects of the addition of Triton X-100 (hereinafter shortened as TX) in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to induce interlayer diffusion between PEDOT:PSS and PFO to enhance the stability of the PFO phase and suppress its oxidation. Photoluminescence (PL) measurement on PFO/TX-mixed PEDOT:PSS layers revealed that, upon increasing the concentration of TX in the PEDOT:PSS layer, the β phase of PFO could be suppressed in favor of the glassy phase and the wide PL emission centered at 535 nm caused by ketone defects formed by oxidation was decreased considerably. LEDs were then fabricated using PFO as an emission layer, TX-mixed PEDOT:PSS as hole-transport layer, and zinc oxide (ZnO) nanorods as electron-transport layer. As the TX concentration reached 3 wt %, the devices exhibited dramatic increases in current densities, which were attributed to the enhanced hole injection due to TX addition, along with a shift in the dominant emission wavelength from a green electroluminescence (EL) emission centered at 518 nm to a blue EL emission centered at 448 nm. The addition of TX in PEDOT:PSS induced a better hole injection in the PFO layer, and through interlayer diffusion, stabilized the glassy phase of PFO and limited the formation of oxidation defects.

  17. The effect of location on the microstructure and mechanical properties of titanium aluminides produced by additive layer manufacturing using in-situ alloying and gas tungsten arc welding

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yan; Cuiuri, Dominic; Hoye, Nicholas; Li, Huijun; Pan, Zengxi, E-mail: zengxi@uow.edu.au

    2015-04-17

    An innovative and low cost additive layer manufacturing (ALM) process is used to produce γ-TiAl based alloy wall components. Gas tungsten arc welding (GTAW) provides the heat source for this new approach, combined with in-situ alloying through separate feeding of commercially pure Ti and Al wires into the weld pool. This paper investigates the morphology, microstructure and mechanical properties of the additively manufactured TiAl material, and how these are affected by the location within the manufactured component. The typical additively layer manufactured morphology exhibits epitaxial growth of columnar grains and several layer bands. The fabricated γ-TiAl based alloy consists of comparatively large α{sub 2} grains in the near-substrate region, fully lamellar colonies with various sizes and interdendritic γ structure in the intermediate layer bands, followed by fine dendrites and interdendritic γ phases in the top region. Microhardness measurements and tensile testing results indicated relatively homogeneous mechanical characteristics throughout the deposited material. The exception to this homogeneity occurs in the near-substrate region immediately adjacent to the pure Ti substrate used in these experiments, where the alloying process is not as well controlled as in the higher regions. The tensile properties are also different for the vertical (build) direction and horizontal (travel) direction because of the differing microstructure in each direction. The microstructure variation and strengthening mechanisms resulting from the new manufacturing approach are analysed in detail. The results demonstrate the potential to produce full density titanium aluminide components directly using the new additive layer manufacturing method.

  18. The effect of location on the microstructure and mechanical properties of titanium aluminides produced by additive layer manufacturing using in-situ alloying and gas tungsten arc welding

    International Nuclear Information System (INIS)

    Ma, Yan; Cuiuri, Dominic; Hoye, Nicholas; Li, Huijun; Pan, Zengxi

    2015-01-01

    An innovative and low cost additive layer manufacturing (ALM) process is used to produce γ-TiAl based alloy wall components. Gas tungsten arc welding (GTAW) provides the heat source for this new approach, combined with in-situ alloying through separate feeding of commercially pure Ti and Al wires into the weld pool. This paper investigates the morphology, microstructure and mechanical properties of the additively manufactured TiAl material, and how these are affected by the location within the manufactured component. The typical additively layer manufactured morphology exhibits epitaxial growth of columnar grains and several layer bands. The fabricated γ-TiAl based alloy consists of comparatively large α 2 grains in the near-substrate region, fully lamellar colonies with various sizes and interdendritic γ structure in the intermediate layer bands, followed by fine dendrites and interdendritic γ phases in the top region. Microhardness measurements and tensile testing results indicated relatively homogeneous mechanical characteristics throughout the deposited material. The exception to this homogeneity occurs in the near-substrate region immediately adjacent to the pure Ti substrate used in these experiments, where the alloying process is not as well controlled as in the higher regions. The tensile properties are also different for the vertical (build) direction and horizontal (travel) direction because of the differing microstructure in each direction. The microstructure variation and strengthening mechanisms resulting from the new manufacturing approach are analysed in detail. The results demonstrate the potential to produce full density titanium aluminide components directly using the new additive layer manufacturing method

  19. Diversity of shrub tree layer, leaf litter decomposition and N release in a Brazilian Cerrado under N, P and N plus P additions

    International Nuclear Information System (INIS)

    Khan Baiocchi Jacobson, Tamiel; Cunha Bustamante, Mercedes Maria da; Rodrigues Kozovits, Alessandra

    2011-01-01

    This study investigated changes in diversity of shrub-tree layer, leaf decomposition rates, nutrient release and soil NO fluxes of a Brazilian savanna (cerrado sensu stricto) under N, P and N plus P additions. Simultaneous addition of N and P affected density, dominance, richness and diversity patterns more significantly than addition of N or P separately. Leaf litter decomposition rates increased in P and NP plots but did not differ in N plots in comparison to control plots. N addition increased N mass loss, while the combined addition of N and P resulted in an immobilization of N in leaf litter. Soil NO emissions were also higher when N was applied without P. The results indicate that if the availability of P is not increased proportionally to the availability of N, the losses of N are intensified. - Highlights: → Simultaneous addition of N and P affected richness and diversity of the shrub-tree layer of a Brazilian savanna more significantly than addition of N or P separately. → Leaf litter decomposition rates increased in P and NP plots but did not differ in N plots in comparison to control plots. N addition increased N mass loss, while the combined addition of N and P resulted in an immobilization of N in leaf litter. Soil NO emissions were also higher when N was applied without P. → The results indicated that if increases in N deposition in Cerrado ecosystems are not accompanied by P additions, higher N losses through leaching and gas emissions can occur with other ecosystem impacts. - Shrub-tree diversity and functioning of Brazilian savanna are affected by increasing nutrient availability.

  20. Diversity of shrub tree layer, leaf litter decomposition and N release in a Brazilian Cerrado under N, P and N plus P additions

    Energy Technology Data Exchange (ETDEWEB)

    Khan Baiocchi Jacobson, Tamiel, E-mail: tamiel@unb.br [Departamento de Ecologia, Universidade de Brasilia, Brasilia-DF 70919-970 (Brazil); Cunha Bustamante, Mercedes Maria da, E-mail: mercedes@unb.br [Departamento de Ecologia, Universidade de Brasilia, Brasilia-DF 70919-970 (Brazil); Rodrigues Kozovits, Alessandra, E-mail: kozovits@icep.ufop.br [Departamento de Ecologia, Universidade de Brasilia, Brasilia-DF 70919-970 (Brazil)

    2011-10-15

    This study investigated changes in diversity of shrub-tree layer, leaf decomposition rates, nutrient release and soil NO fluxes of a Brazilian savanna (cerrado sensu stricto) under N, P and N plus P additions. Simultaneous addition of N and P affected density, dominance, richness and diversity patterns more significantly than addition of N or P separately. Leaf litter decomposition rates increased in P and NP plots but did not differ in N plots in comparison to control plots. N addition increased N mass loss, while the combined addition of N and P resulted in an immobilization of N in leaf litter. Soil NO emissions were also higher when N was applied without P. The results indicate that if the availability of P is not increased proportionally to the availability of N, the losses of N are intensified. - Highlights: > Simultaneous addition of N and P affected richness and diversity of the shrub-tree layer of a Brazilian savanna more significantly than addition of N or P separately. > Leaf litter decomposition rates increased in P and NP plots but did not differ in N plots in comparison to control plots. N addition increased N mass loss, while the combined addition of N and P resulted in an immobilization of N in leaf litter. Soil NO emissions were also higher when N was applied without P. > The results indicated that if increases in N deposition in Cerrado ecosystems are not accompanied by P additions, higher N losses through leaching and gas emissions can occur with other ecosystem impacts. - Shrub-tree diversity and functioning of Brazilian savanna are affected by increasing nutrient availability.

  1. Identification of Typical Left Bundle Branch Block Contraction by Strain Echocardiography Is Additive to Electrocardiography in Prediction of Long-Term Outcome After Cardiac Resynchronization Therapy

    DEFF Research Database (Denmark)

    Risum, Niels; Tayal, Bhupendar; Hansen, Thomas F

    2015-01-01

    BACKGROUND: Current guidelines suggest that patients with left bundle branch block (LBBB) be treated with cardiac resynchronization therapy (CRT); however, one-third do not have a significant activation delay, which can result in nonresponse. By identifying characteristic opposing wall contraction...... (ECG) morphology and duration. METHODS: From 2 centers, 208 CRT candidates (New York Heart Association classes II to IV, ejection fraction ≤35%, QRS duration ≥120 ms) with LBBB by ECG were prospectively included. Before CRT implantation, longitudinal strain in the apical 4-chamber view determined...... whether typical LBBB contraction was present. The pre-defined outcome was freedom from death, left ventricular assist device, or heart transplantation over 4 years. RESULTS: Two-thirds of patients (63%) had a typical LBBB contraction pattern. During 4 years, 48 patients (23%) reached the primary endpoint...

  2. Effect of addition of dexamethasone to ropivacaine on post-operative analgesia in ultrasonography-guided transversus abdominis plane block for inguinal hernia repair: A prospective, double-blind, randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Uma Datt Sharma

    2018-01-01

    Full Text Available Background and Aims: Ultrasonography (USG-guided transversus abdominis plane (TAP block is an abdominal field block with high efficacy. This study was undertaken with the aim of determining the effect of the addition of dexamethasone to 0.5% ropivacaine on post-operative analgesia in USG-guided TAP block for inguinal hernia repair. Methods: A double-blind randomised control study was conducted on sixty patients posted for inguinal hernia repair with the American Society of Anesthesiologists physical Status I or II, who were allocated two groups of 30 each. Patients in Group RS received 0.5% ropivacaine (20 ml and normal saline (2 ml whereas patients in Group RD received 0.5% ropivacaine (20 ml and dexamethasone (2 ml, i.e., 8 mg, in USG-guided TAP Block on the same side, after repair of inguinal hernia under spinal anaesthesia. Visual analogue scale (VAS scores, time for request of first analgesia and total tramadol consumption in first 24 h were compared. Unpaired Student's t-test and Mann–Whitney U-test were performed using SPSS 23 Software. Results: Patients in Group RD had significantly lower VAS scores as compared to Group RS from 4th to 12th h, postoperatively. Duration of analgesia was significantly more in Group RD (547.50 [530,530] min when compared with Group RS (387.50 [370,400] min (P < 0.001. The demand for intravenous tramadol was significantly low in Group RD (223.33 ± 56.83 mg as compared to Group RS (293.33 ± 25.71 mg (P < 0.001. Conclusion: Addition of dexamethasone to ropivacaine in USG-guided TAP block significantly reduces post-operative pain and prolongs the duration of post-operative analgesia, thereby reducing analgesic consumption.

  3. Effect of addition of dexamethasone to ropivacaine on post-operative analgesia in ultrasonography-guided transversus abdominis plane block for inguinal hernia repair: A prospective, double-blind, randomised controlled trial.

    Science.gov (United States)

    Sharma, Uma Datt; Prateek; Tak, Himani

    2018-05-01

    Ultrasonography (USG)-guided transversus abdominis plane (TAP) block is an abdominal field block with high efficacy. This study was undertaken with the aim of determining the effect of the addition of dexamethasone to 0.5% ropivacaine on post-operative analgesia in USG-guided TAP block for inguinal hernia repair. A double-blind randomised control study was conducted on sixty patients posted for inguinal hernia repair with the American Society of Anesthesiologists physical Status I or II, who were allocated two groups of 30 each. Patients in Group RS received 0.5% ropivacaine (20 ml) and normal saline (2 ml) whereas patients in Group RD received 0.5% ropivacaine (20 ml) and dexamethasone (2 ml, i.e., 8 mg), in USG-guided TAP Block on the same side, after repair of inguinal hernia under spinal anaesthesia. Visual analogue scale (VAS) scores, time for request of first analgesia and total tramadol consumption in first 24 h were compared. Unpaired Student's t -test and Mann-Whitney U-test were performed using SPSS 23 Software. Patients in Group RD had significantly lower VAS scores as compared to Group RS from 4 th to 12 th h, postoperatively. Duration of analgesia was significantly more in Group RD (547.50 [530,530] min) when compared with Group RS (387.50 [370,400] min) ( P consumption.

  4. Epidural block

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000484.htm Epidural block - pregnancy To use the sharing features on this page, please enable JavaScript. An epidural block is a numbing medicine given by injection (shot) ...

  5. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  6. Functional solid additive modified PEDOT:PSS as an anode buffer layer for enhanced photovoltaic performance and stability in polymer solar cells

    Science.gov (United States)

    Xu, Binrui; Gopalan, Sai-Anand; Gopalan, Anantha-Iyengar; Muthuchamy, Nallal; Lee, Kwang-Pill; Lee, Jae-Sung; Jiang, Yu; Lee, Sang-Won; Kim, Sae-Wan; Kim, Ju-Seong; Jeong, Hyun-Min; Kwon, Jin-Beon; Bae, Jin-Hyuk; Kang, Shin-Won

    2017-01-01

    Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is most commonly used as an anode buffer layer in bulk-heterojunction (BHJ) polymer solar cells (PSCs). However, its hygroscopic and acidic nature contributes to the insufficient electrical conductivity, air stability and restricted photovoltaic (PV) performance for the fabricated PSCs. In this study, a new multifunctional additive, 2,3-dihydroxypyridine (DOH), has been used in the PEDOT: PSS buffer layer to obtain modified properties for PEDOT: PSS@DOH and achieve high PV performances. The electrical conductivity of PEDOT:PSS@DOH films was markedly improved compared with that of PEDOT:PSS. The PEDOT:PSS@DOH film exhibited excellent optical characteristics, appropriate work function alignment, and good surface properties in BHJ-PSCs. When a poly(3-hexylthiohpene):[6,6]-phenyl C61-butyric acid methyl ester blend system was applied as the photoactive layer, the power conversion efficiency of the resulting PSCs with PEDOT:PSS@DOH(1.0%) reached 3.49%, outperforming pristine PEDOT:PSS, exhibiting a power conversion enhancement of 20%. The device fabricated using PEDOT:PSS@DOH (1.0 wt%) also exhibited improved thermal and air stability. Our results also confirm that DOH, a basic pyridine derivative, facilitates adequate hydrogen bonding interactions with the sulfonic acid groups of PSS, induces the conformational transformation of PEDOT chains and contributes to the phase separation between PEDOT and PSS chains. PMID:28338088

  7. Permuting the PGF Signature Motif Blocks both Archaeosortase-Dependent C-Terminal Cleavage and Prenyl Lipid Attachment for the Haloferax volcanii S-Layer Glycoprotein.

    Science.gov (United States)

    Abdul Halim, Mohd Farid; Karch, Kelly R; Zhou, Yitian; Haft, Daniel H; Garcia, Benjamin A; Pohlschroder, Mechthild

    2015-12-28

    For years, the S-layer glycoprotein (SLG), the sole component of many archaeal cell walls, was thought to be anchored to the cell surface by a C-terminal transmembrane segment. Recently, however, we demonstrated that the Haloferax volcanii SLG C terminus is removed by an archaeosortase (ArtA), a novel peptidase. SLG, which was previously shown to be lipid modified, contains a C-terminal tripartite structure, including a highly conserved proline-glycine-phenylalanine (PGF) motif. Here, we demonstrate that ArtA does not process an SLG variant where the PGF motif is replaced with a PFG motif (slg(G796F,F797G)). Furthermore, using radiolabeling, we show that SLG lipid modification requires the PGF motif and is ArtA dependent, lending confirmation to the use of a novel C-terminal lipid-mediated protein-anchoring mechanism by prokaryotes. Similar to the case for the ΔartA strain, the growth, cellular morphology, and cell wall of the slg(G796F,F797G) strain, in which modifications of additional H. volcanii ArtA substrates should not be altered, are adversely affected, demonstrating the importance of these posttranslational SLG modifications. Our data suggest that ArtA is either directly or indirectly involved in a novel proteolysis-coupled, covalent lipid-mediated anchoring mechanism. Given that archaeosortase homologs are encoded by a broad range of prokaryotes, it is likely that this anchoring mechanism is widely conserved. Prokaryotic proteins bound to cell surfaces through intercalation, covalent attachment, or protein-protein interactions play critical roles in essential cellular processes. Unfortunately, the molecular mechanisms that anchor proteins to archaeal cell surfaces remain poorly characterized. Here, using the archaeon H. volcanii as a model system, we report the first in vivo studies of a novel protein-anchoring pathway involving lipid modification of a peptidase-processed C terminus. Our findings not only yield important insights into poorly understood

  8. Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

    International Nuclear Information System (INIS)

    Li, Shuo; Bhushan, Bharat

    2016-01-01

    Highlights: • Mg/Al-, Zn/Al- and Zn/Mg/Al-layered double hydroxide were synthesized. • Mg/Al-LDH had superior tribological performance compared to other LDHs. • The best thermal stability of Mg/Al-LDH was responsible for its friction property. - Abstract: Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.

  9. Lubrication performance and mechanisms of Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxide nanoparticles as lubricant additives

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shuo [School of Materials Science and Technology, China University of Geosciences (Beijing), 29 Xueyuan Road, Haidian Distract, Beijing 100083 (China); Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue Columbus, OH 43210-1142 (United States); Bhushan, Bharat, E-mail: bhushan.2@osu.edu [Nanoprobe Laboratory for Bio- & Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue Columbus, OH 43210-1142 (United States)

    2016-08-15

    Highlights: • Mg/Al-, Zn/Al- and Zn/Mg/Al-layered double hydroxide were synthesized. • Mg/Al-LDH had superior tribological performance compared to other LDHs. • The best thermal stability of Mg/Al-LDH was responsible for its friction property. - Abstract: Solid lubricant particles are commonly used as oil additives for low friction and wear. Mg/Al-, Zn/Al-, and Zn/Mg/Al-layered double hydroxides (LDH) were synthesized by coprecipitation method. The benefits of LDH nanoparticles are that they can be synthesized using chemical methods where size and shape can be controlled, and can be modified organically to allow dispersal in fluids. The LDH nanoparticles were characterized by X-ray diffraction, scanning electron microscope, thermogravimetry, and differential scanning calorimetry. A pin-on-disk friction and wear tester was used for evaluating the friction and wear properties of LDH nanoparticles as lubricant additives. LDH nanoparticles have friction-reducing and anti-wear properties compared to oil without LDHs. Mg/Al-LDH has the best lubrication, possibly due to better thermal stability in severe conditions.

  10. Additional Layers of Violence: The Intersections of Gender and Disability in the Violence Experiences of Women With Physical Disabilities in South Africa.

    Science.gov (United States)

    van der Heijden, Ingrid; Abrahams, Naeemah; Harries, Jane

    2016-04-27

    South Africa has unprecedented levels of violence and many South African women are exposed to violence during their lifetime. This article explores how gender and disability intersect in women's experiences of violence during their lifetime. Repeat in-depth qualitative interviews with 30 physically disabled women in Cape Town reveal that women with physical disabilities are exposed to various forms of violence, and shows how their impairments shape their violence experiences. The most common forms of violence women with disabilities experience are psychological violence, financial abuse, neglect, and deprivation, with disability stigma playing a central role and contributing to how women with disabilities are exploited and dehumanized. Constructions of women as asexual shape their sexual relationships and experiences of sexual violence. This article identifies that women with disabilities are more at risk and experience additional layers of violence than women without disabilities. These additional risks and layers of violence need to be recognized and inform interventions to prevent and respond to violence against women with disabilities in the country. Prevention of violence against women with physical disabilities in South Africa needs to address the role of disability stigma that shapes the types of violence they experience, change gender norms, and create accessible and safe environments and economic empowerment opportunities. © The Author(s) 2016.

  11. Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells

    Czech Academy of Sciences Publication Activity Database

    Krýsová, Hana; Krýsa, J.; Kavan, Ladislav

    2018-01-01

    Roč. 9, APR 2018 (2018), s. 1135-1145 ISSN 2190-4286 R&D Projects: GA ČR GA17-20008S; GA ČR(CZ) GA18-08959s Institutional support: RVO:61388955 Keywords : blocking films * FTO * solar cells Subject RIV: CG - Electrochemistry OBOR OECD: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis) Impact factor: 3.127, year: 2016

  12. Optical and electronic proprieties of thin films based on (Z-5-(4-chlorobenzylidene-3-(2-ethoxyphenyl-2 thioxothiazolidin-4-one, (CBBTZ and possible application as exciton-blocking layer in heterojunction organic solar cells

    Directory of Open Access Journals (Sweden)

    Morsli M.

    2012-06-01

    Full Text Available In this work, organic thin film solar cells with structures based on CuPc/C60 bulk heterojunctions, have been fabricated and characterized. The effect of introducing an exciton blocking layer (EBL between the active layer and the metal layer in the solar cell was investigated. For that (Z-5-(4-chlorobenzylidene-3-(2-ethoxyphenyl-2-thioxothiazolidin-4-one, that we called (CBBTZ has been synthesized, characterized and probed as EBL. It was shown that optimized structures containing EBLs resulted in an improvement in solar cell conversion efficiencies. The energy levels corresponding to the highest occupied molecular orbital (HOMO and the lowest unoccupied molecular orbital (LUMO of the CBBTZ have been determined from the first oxidation and reduction potential respectively, using cyclic voltametric (CV measurements. From CV curves, CBBTZ in dichloromethane showed a one electron reversible reduction and oxidation waves. The values of its HOMO and LUMO have been estimated to be 6.42 eV and 3.42 eV respectively. Such values show that CBBTZ could be probed as EBL in organic solar cells based on the ED/EA couple copper phthalocyanine(CuPc/fullerene (C60. The photovoltaic solar cells have been obtained by sequential deposition under vacuum of the different films where their thicknesses were measured in situ by a quartz monitor. When obtained, the averaged efficiency of the cells using the CBBTZ is higher than that achieved without EBL layer.

  13. Cross-stacked carbon nanotube film as an additional built-in current collector and adsorption layer for high-performance lithium sulfur batteries.

    Science.gov (United States)

    Sun, Li; Kong, Weibang; Li, Mengya; Wu, Hengcai; Jiang, Kaili; Li, Qunqing; Zhang, Yihe; Wang, Jiaping; Fan, Shoushan

    2016-02-19

    Cross-stacked carbon nanotube (CNT) film is proposed as an additional built-in current collector and adsorption layer in sulfur cathodes for advanced lithium sulfur (Li-S) batteries. On one hand, the CNT film with high conductivity, microstructural rough surface, high flexibility and mechanical durability retains stable and direct electronic contact with the sulfur cathode materials, therefore decreasing internal resistivity and suppressing polarization of the cathode. On the other hand, the highly porous structure and the high surface area of the CNT film provide abundant adsorption points to support and confine sulfur cathode materials, alleviate their aggregation and promote high sulfur utilization. Moreover, the lightweight and compact structure of the CNT film adds no extra weight or volume to the sulfur cathode, benefitting the improvement of energy densities. Based on these characteristics, the sulfur cathode with a 100-layer cross-stacked CNT film presents excellent rate performances with capacities of 986, 922 and 874 mAh g(-1) at cycling rates of 0.2C, 0.5C and 1C for sulfur loading of 60 wt%, corresponding to an improvement of 52%, 109% and 146% compared to that without a CNT film. Promising cycling performances are also demonstrated, offering great potential for scaled-up production of sulfur cathodes for Li-S batteries.

  14. Block storage subsystem performance analysis

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    You feel that your service is slow because of the storage subsystem? But there are too many abstraction layers between your software and the raw block device for you to debug all this pile... Let's dive on the platters and check out how the block storage sees your I/Os! We can even figure out what those patterns are meaning.

  15. Charge trapping characteristics of Au nanocrystals embedded in remote plasma atomic layer-deposited Al2O3 film as the tunnel and blocking oxides for nonvolatile memory applications

    International Nuclear Information System (INIS)

    Lee, Jaesang; Kim, Hyungchul; Park, Taeyong; Ko, Youngbin; Ryu, Jaehun; Jeon, Heeyoung; Park, Jingyu; Jeon, Hyeongtag

    2012-01-01

    Remote plasma atomic layer deposited (RPALD) Al 2 O 3 films were investigated to apply as tunnel and blocking layers in the metal-oxide-semiconductor capacitor memory utilizing Au nanocrystals (NCs) for nonvolatile memory applications. The interface stability of an Al 2 O 3 film deposited by RPALD was studied to observe the effects of remote plasma on the interface. The interface formed during RPALD process has high oxidation states such as Si +3 and Si +4 , indicating that RPALD process can grow more stable interface which has a small amount of fixed oxide trap charge. The significant memory characteristics were also observed in this memory device through the electrical measurement. The memory device exhibited a relatively large memory window of 5.6 V under a 10/-10 V program/erase voltage and also showed the relatively fast programming/erasing speed and a competitive retention characteristic after 10 4 s. These results indicate that Al 2 O 3 films deposited via RPALD can be applied as the tunnel and blocking oxides for next-generation flash memory devices.

  16. A Perron–Frobenius theory for block matrices associated to a multiplex network

    International Nuclear Information System (INIS)

    Romance, Miguel; Solá, Luis; Flores, Julio; García, Esther; García del Amo, Alejandro; Criado, Regino

    2015-01-01

    The uniqueness of the Perron vector of a nonnegative block matrix associated to a multiplex network is discussed. The conclusions come from the relationships between the irreducibility of some nonnegative block matrix associated to a multiplex network and the irreducibility of the corresponding matrices to each layer as well as the irreducibility of the adjacency matrix of the projection network. In addition the computation of that Perron vector in terms of the Perron vectors of the blocks is also addressed. Finally we present the precise relations that allow to express the Perron eigenvector of the multiplex network in terms of the Perron eigenvectors of its layers

  17. A Perron-Frobenius theory for block matrices associated to a multiplex network

    Science.gov (United States)

    Romance, Miguel; Solá, Luis; Flores, Julio; García, Esther; García del Amo, Alejandro; Criado, Regino

    2015-03-01

    The uniqueness of the Perron vector of a nonnegative block matrix associated to a multiplex network is discussed. The conclusions come from the relationships between the irreducibility of some nonnegative block matrix associated to a multiplex network and the irreducibility of the corresponding matrices to each layer as well as the irreducibility of the adjacency matrix of the projection network. In addition the computation of that Perron vector in terms of the Perron vectors of the blocks is also addressed. Finally we present the precise relations that allow to express the Perron eigenvector of the multiplex network in terms of the Perron eigenvectors of its layers.

  18. Effect of sodium acetate additive in successive ionic layer adsorption and reaction on the performance of CdS quantum-dot-sensitized solar cells

    Science.gov (United States)

    Liu, I.-Ping; Chen, Liang-Yih; Lee, Yuh-Lang

    2016-09-01

    Sodium acetate (NaAc) is utilized as an additive in cationic precursors of the successive ionic layer adsorption and reaction (SILAR) process to fabricate CdS quantum-dot (QD)-sensitized photoelectrodes. The effects of the NaAc concentration on the deposition rate and distribution of QDs in mesoporous TiO2 films, as well as on the performance of CdS-sensitized solar cells are studied. The experimental results show that the presence of NaAc can significantly accelerate the deposition of CdS, improve the QD distribution across photoelectrodes, and thereby, increase the performance of solar cells. These results are mainly attributed to the pH-elevation effect of NaAc to the cationic precursors which increases the electrostatic interaction of the TiO2 film to cadmium ions. The light-to-energy conversion efficiency of the CdS-sensitized solar cell increases with increasing concentration of the NaAc and approaches a maximum value (3.11%) at 0.05 M NaAc. Additionally, an ionic exchange is carried out on the photoelectrode to transform the deposited CdS into CdS1-xSex ternary QDs. The light-absorption range of the photoelectrode is extended and an exceptional power conversion efficiency of 4.51% is achieved due to this treatment.

  19. Thin Layer Chromatographic Resolution of Some β-adrenolytics and a β2-Agonist Using Bovine Serum Albumin as Chiral Additive in Stationary Phase.

    Science.gov (United States)

    Malik, Poonam; Bhushan, Ravi

    2018-01-01

    Direct enantiomeric resolution of commonly used five racemic β-adrenolytics, namely, bisoprolol, atenolol, propranolol, salbutamol and carvedilol has been achieved by thin layer chromatography using bovine serum albumin (BSA) as chiral additive in stationary phase. Successful resolution of the enantiomers of all racemic β-adrenolytics was achieved by use of different composition of simple organic solvents having no buffer or inorganic ions. The effect of variation in pH, temperature, amount of BSA as the additive, and composition of mobile phase on resolution was systematically studied. Spots were visualized in iodine vapors. Native enantiomers for each of the five analytes were isolated and identified and their elution order was determined. The limit of detection was found to be 0.7, 1.2, 0.84, 1.6 and 0.9 μg (per spot) for each enantiomer of bisoprolol, atenolol, propranolol, salbutamol and carvedilol, respectively. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. THE THICKNESS DEPENDENCE OF OXYGEN PERMEABILITY IN SOL-GEL DERIVED CGO-COFE2O4 THIN FILMS ON POROUS CERAMIC SUBSTRATES: A SPUTTERED BLOCKING LAYER FOR THICKNESS CONTROL

    Energy Technology Data Exchange (ETDEWEB)

    Brinkman, K

    2009-01-08

    Mixed conductive oxides are a topic of interest for applications in oxygen separation membranes as well as use in producing hydrogen fuel through the partial oxidation of methane. The oxygen flux through the membrane is governed both by the oxygen ionic conductivity as well as the material's electronic conductivity; composite membranes like Ce{sub 0.8}Gd{sub 0.2}O{sub 2-{delta}} (CGO)-CoFe{sub 2}O{sub 4} (CFO) use gadolinium doped ceria oxides as the ionic conducting material combined with cobalt iron spinel which serves as the electronic conductor. In this study we employ {approx} 50 nm sputtered CeO{sub 2} layers on the surface of porous CGO ceramic substrates which serve as solution 'blocking' layers during the thin film fabrication process facilitating the control of film thickness. Films with thickness of {approx} 2 and 4 microns were prepared by depositing 40 and 95 separate sol-gel layers respectively. Oxygen flux measurements indicated that the permeation increased with decreasing membrane thickness; thin film membrane with thickness on the micron level showed flux values an order of magnitude greater (0.03 {micro}mol/cm{sup 2} s) at 800 C as compared to 1mm thick bulk ceramic membranes (0.003 {micro}mol/cm{sup 2}).

  1. Detection block

    International Nuclear Information System (INIS)

    Bezak, A.

    1987-01-01

    A diagram is given of a detection block used for monitoring burnup of nuclear reactor fuel. A shielding block is an important part of the detection block. It stabilizes the fuel assembly in the fixing hole in front of a collimator where a suitable gamma beam is defined for gamma spectrometry determination of fuel burnup. The detector case and a neutron source case are placed on opposite sides of the fixing hole. For neutron measurement for which the water in the tank is used as a moderator, the neutron detector-fuel assembly configuration is selected such that neutrons from spontaneous fission and neutrons induced with the neutron source can both be measured. The patented design of the detection block permits longitudinal travel and rotation of the fuel assembly to any position, and thus more reliable determination of nuclear fuel burnup. (E.S.). 1 fig

  2. Nearly Efficiency-Droop-Free AlGaN-Based Ultraviolet Light-Emitting Diodes with a Specifically Designed Superlattice p-Type Electron Blocking Layer for High Mg Doping Efficiency

    Science.gov (United States)

    Zhang, Zi-Hui; Huang Chen, Sung-Wen; Chu, Chunshuang; Tian, Kangkai; Fang, Mengqian; Zhang, Yonghui; Bi, Wengang; Kuo, Hao-Chung

    2018-04-01

    This work reports a nearly efficiency-droop-free AlGaN-based deep ultraviolet light-emitting diode (DUV LED) emitting in the peak wavelength of 270 nm. The DUV LED utilizes a specifically designed superlattice p-type electron blocking layer (p-EBL). The superlattice p-EBL enables a high hole concentration in the p-EBL which correspondingly increases the hole injection efficiency into the multiple quantum wells (MQWs). The enhanced hole concentration within the MQW region can more efficiently recombine with electrons in the way of favoring the radiative recombination, leading to a reduced electron leakage current level. As a result, the external quantum efficiency for the proposed DUV LED structure is increased by 100% and the nearly efficiency-droop-free DUV LED structure is obtained experimentally.

  3. Plasma confinement modification and convective transport suppression in the scrape-off layer using additional gas puffing in the STOR-M tokamak

    International Nuclear Information System (INIS)

    Dreval, M; Hubeny, M; Ding, Y; Onchi, T; Liu, Y; Hthu, K; Elgriw, S; Xiao, C; Hirose, A

    2013-01-01

    The influence of short gas puffing (GP) pulses on the scrape-off layer (SOL) transport is studied. Similar responses of ion saturation current and floating potential measured near the GP injection valve and in the 90° toroidally separated cross-section suggest that the GP influence on the SOL region should be global. A drop in plasma temperature and a decrease in the rotational velocity of the plasma are observed in the SOL region immediately after the GP pulse; however, an unexpected increase in electron and ion temperatures is observed in the second stage of the plasma response. The decrease in floating potential fluctuations indicates that the turbulent transport is dumped immediately after the GP pulse. The GP-induced modification of turbulence properties in the SOL points to a convective transport suppression in the STOR-M tokamak. A substantial decrease in the skewness and kurtosis of ion saturation current fluctuations is observed in the SOL region resulting in the probability distribution function (PDF) getting closer to the Gaussian distribution. The plasma potential reduction, the change in plasma rotation and the suppression of turbulent transport in the SOL region indicate that the plasma confinement is modified after the GP injection. Some features of the H-mode-like confinement in the plasma bulk also accompany the SOL observations after application of the additional sharp GP pulse. (paper)

  4. Effect of La2O3 addition on interface chemistry between 4YSZ top layer and Ni based alloy bond coat in thermal barrier coating by EB PVD.

    Science.gov (United States)

    Park, Chan-Young; Yang, Young-Hwan; Kim, Seong-Won; Lee, Sung-Min; Kim, Hyung-Tae; Jang, Byung-Koog; Lim, Dae-Soon; Oh, Yoon-Suk

    2014-11-01

    The effect of a 5 mol% La2O3 addition on the forming behavior and compositional variation at interface between a 4 mol% Yttria (Y2O3) stabilized ZrO2 (4YSZ) top coat and bond coat (NiCrAlY) as a thermal barrier coating (TBC) has been investigated. Top coats were deposited by electron beam physical vapor deposition (EB PVD) onto a super alloy (Ni-Cr-Co-Al) substrate without pre-oxidation of the bond coat. Top coats are found to consist of dense columnar grains with a thin interdiffusion layer between metallic bond coats. In the as-received 4YSZ coating, a thin interdiffusion zone at the interface between the top and bond coats was found to consist of a Ni-Zr intermetallic compound with a reduced quantity of Y, Al or O elements. On the other hand, in the case of an interdiffusion area of 5 mol% La2O3-added 4YSZ coating, it was found that the complicated composition and structure with La-added YSZ and Ni-Al rich compounds separately. The thermal conductivity of 5 mol% La2O3-added 4YSZ coating (- 1.6 W/m x k at 1100 degrees C) was lower than a 4YSZ coating (- 3.2 W/m x k at 1100 degrees C) alone.

  5. Modelling of current-voltage characteristics of infrared photo-detectors based on type – II InAs/GaSb super-lattice diodes with unipolar blocking layers

    Directory of Open Access Journals (Sweden)

    Vishnu Gopal

    2015-09-01

    Full Text Available It is shown that current-voltage characteristics of infrared photo-detectors based on type-II InAs/GaSb super-lattices with uni-polar blocking layers can be modelled similar to a junction diode with a finite series resistance on account of blocking barriers. As an example this paper presents the results of a study of current-voltage characteristics of a type II InAs/GaSb super-lattice diode with PbIbN architecture using a recently proposed [J. Appl. Phys. 116, 084502 (2014] method for modelling of illuminated photovoltaic detectors. The thermal diffusion, generation – recombination (g-r, and ohmic currents are found as principal components besides a component of photocurrent due to background illumination. The experimentally observed reverse bias diode current in excess of thermal current (diffusion + g-r, photo-current and ohmic shunt current is reported to be best described by an exponential function of the type, Iexcess = Ir0 + K1exp(K2 V, where Ir0, K1 and K2 are fitting parameters and V is the applied bias voltage. The present investigations suggest that the exponential growth of excess current with the applied bias voltage may be taking place along the localized regions in the diode. These localized regions are the shunt resistance paths on account of the surface leakage currents and/or defects and dislocations in the base of the diode.

  6. Predictability of blocking

    International Nuclear Information System (INIS)

    Tosi, E.; Ruti, P.; Tibaldi, S.; D'Andrea, F.

    1994-01-01

    Tibaldi and Molteni (1990, hereafter referred to as TM) had previously investigated operational blocking predictability by the ECMWF model and the possible relationships between model systematic error and blocking in the winter season of the Northern Hemisphere, using seven years of ECMWF operational archives of analyses and day 1 to 10 forecasts. They showed that fewer blocking episodes than in the real atmosphere were generally simulated by the model, and that this deficiency increased with increasing forecast time. As a consequence of this, a major contribution to the systematic error in the winter season was shown to derive from the inability of the model to properly forecast blocking. In this study, the analysis performed in TM for the first seven winter seasons of the ECMWF operational model is extended to the subsequent five winters, during which model development, reflecting both resolution increases and parametrisation modifications, continued unabated. In addition the objective blocking index developed by TM has been applied to the observed data to study the natural low frequency variability of blocking. The ability to simulate blocking of some climate models has also been tested

  7. Toward Composable Hardware Agnostic Communications Blocks Lessons Learned

    Science.gov (United States)

    2016-11-01

    block-by-block level or on a multi- block level. In the block-by-block pushback approach, queues between each block are small and blocks processing data...medium access, and physical layers of the waveform has limited our ability to take advantage of technology advances in signal processing , rate...pro- cessing functions, and application processing functions as shown in Figure 1 [1]. Transceiver functions are functions associated with transmitting

  8. Electronic structures of (Pb sub 2 Cu)Sr sub 2 Eu sub x Ce sub n sub - sub x Cu sub 2 O sub 2 sub n sub + sub 6 (n=2, 3): Effect of fluorite blocks between adjacent CuO sub 2 layers

    CERN Document Server

    Arai, M

    2003-01-01

    The electronic structures of (Pb sub 2 Cu)Sr sub 2 Eu sub x Ce sub n sub - sub x Cu sub 2 O sub 2 sub n sub + sub 6 (n = 2, 3) compounds which have fluorite blocks between two adjacent CuO sub 2 layers have been studied by using ab-initio method. It is found that the anisotropy is enhanced by inserting the fluorite blocks. The Fermi velocity perpendicular to the CuO sub 2 layers decreases as the thickness of fluorite blocks increases. The Eu substitution is found to affect both the atomic positions and electronic structures. The distance between apical oxygen and copper becomes shorter by the Eu substitution. The energy bands derived from oxygens in the fluorite blocks approach Fermi energy as the content of Eu substitution increases. (author)

  9. Addition of Mn to Ge quantum dot surfaces—interaction with the Ge QD {105} facet and the Ge(001) wetting layer

    International Nuclear Information System (INIS)

    Nolph, C A; Kassim, J K; Floro, J A; Reinke, P

    2013-01-01

    The interaction of Mn with Ge quantum dots (QD), which are bounded by {105} facets, and the strained Ge wetting layer (WL), terminated by a (001) surface, is investigated with scanning tunneling microscopy (STM). These surfaces constitute the growth surfaces in the growth of Mn-doped QDs. Mn is deposited on the Ge QD and WL surface in sub-monolayer concentrations, and subsequently annealed up to a temperature of 400 ° C. The changes in bonding and surface topography are measured with STM during the annealing process. Mn forms flat islands on the Ge{105} facet, whose shape and position are guided by the rebonded step reconstruction of the facet. Voltage-dependent STM images reflect the Mn-island interaction with the empty and filled states of the Ge{105} reconstruction. Scanning tunneling spectra (STS) of the Ge{105} facet and as-deposited Mn-islands show a bandgap of 0.8 eV, and the Mn-island spectra are characterized by an additional empty state at about 1.4 eV. A statistical analysis of Mn-island shape and position on the QD yields a slight preference for edge positions, whereas the QD strain field does not impact Mn-island position. However, the formation of ultra-small Mn-clusters dominates on the Ge(001) WL, which is in contrast to Mn interaction with unstrained Ge(001) surfaces. Annealing to T 5 Ge 3 from a mass balance analysis. This reaction is accompanied by the disappearance of the original Mn-surface structures and de-wetting of Mn is complete. This study unravels the details of Mn–Ge interactions, and demonstrates the role of surface diffusion as a determinant in the growth of Mn-doped Ge materials. Surface doping of Ge-nanostructures at lower temperatures could provide a pathway to control magnetism in the Mn–Ge system. (paper)

  10. Effect of zinc addition on properties of cadmium sulfide layer and performance of Cu(In,Ga)Se{sub 2} solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Dowon, E-mail: bae.dowon@yahoo.co.kr; Gho, Junghwan; Shin, Minjung; Kwon, Sehan

    2013-05-01

    Cd{sub (1−x)}Zn{sub x}S (CdS:Zn) thin films were grown on an indium tin oxide-coated glass substrate and Cu(In,Ga)Se{sub 2} (CIGS) surface by chemical bath deposition for solar cell applications, and their composition, and optical properties were studied to decide the optimum process conditions for buffer layer growth. The average conversion efficiency of CIGS solar panels (24-in.) with the CdS:Zn layer was 0.35% higher than that of conventional solar panels mainly because of the increased open-circuit voltage. This efficiency improvement was not due to modification of the optical properties of the buffer layer, but due to the change in the deposition rate during buffer layer growth. - Highlights: ► CdS:Zn buffer layers were fabricated for Cu(In,Ga)Se{sub 2} (CIGS) photovoltaic (PV) panels. ► Composition of buffer layers on indium–tin–oxide (ITO) and CIGS was investigated. ► Transmittance of CdS:Zn on ITO coated glass showed 5% higher than CdS. ► Efficiency of CdS:Zn solution adopted panels showed 0.47% higher than that with CdS. ► However, it was revealed that only Cd and S ions were found at the surface of CIGS.

  11. Effect of zinc addition on properties of cadmium sulfide layer and performance of Cu(In,Ga)Se2 solar cell

    International Nuclear Information System (INIS)

    Bae, Dowon; Gho, Junghwan; Shin, Minjung; Kwon, Sehan

    2013-01-01

    Cd (1−x) Zn x S (CdS:Zn) thin films were grown on an indium tin oxide-coated glass substrate and Cu(In,Ga)Se 2 (CIGS) surface by chemical bath deposition for solar cell applications, and their composition, and optical properties were studied to decide the optimum process conditions for buffer layer growth. The average conversion efficiency of CIGS solar panels (24-in.) with the CdS:Zn layer was 0.35% higher than that of conventional solar panels mainly because of the increased open-circuit voltage. This efficiency improvement was not due to modification of the optical properties of the buffer layer, but due to the change in the deposition rate during buffer layer growth. - Highlights: ► CdS:Zn buffer layers were fabricated for Cu(In,Ga)Se 2 (CIGS) photovoltaic (PV) panels. ► Composition of buffer layers on indium–tin–oxide (ITO) and CIGS was investigated. ► Transmittance of CdS:Zn on ITO coated glass showed 5% higher than CdS. ► Efficiency of CdS:Zn solution adopted panels showed 0.47% higher than that with CdS. ► However, it was revealed that only Cd and S ions were found at the surface of CIGS

  12. Layer-by-layer strippable Ag multilayer films fabricated by modular assembly.

    Science.gov (United States)

    Li, Yan; Chen, Xiaoyan; Li, Qianqian; Song, Kai; Wang, Shihui; Chen, Xiaoyan; Zhang, Kai; Fu, Yu; Jiao, Yong-Hua; Sun, Ting; Liu, Fu-Chun; Han, En-Hou

    2014-01-21

    We have developed a new method to fabricate multilayer films, which uses prepared thin films as modular blocks and transfer as operation mode to build up multilayer structures. In order to distinguish it from the in situ fabrication manner, this method is called modular assembly in this study. On the basis of such concept, we have fabricated a multilayer film using the silver mirror film as the modular block and poly(lactic acid) as the transfer tool. Due to the special double-layer structure of the silver mirror film, the resulting multilayer film had a well-defined stratified architecture with alternate porous/compact layers. As a consequence of the distinct structure, the interaction between the adjacent layers was so weak that the multilayer film could be layer-by-layer stripped. In addition, the top layer in the film could provide an effective protection on the morphology and surface property of the underlying layers. This suggests that if the surface of the film was deteriorated, the top layer could be peeled off and the freshly exposed surface would still maintain the original function. The successful preparation of the layer-by-layer strippable silver multilayer demonstrates that modular assembly is a feasible and effective method to build up multilayer films capable of creating novel and attractive micro/nanostructures, having great potential in the fabrication of nanodevices and coatings.

  13. Cutaneous Sensory Block Area, Muscle-Relaxing Effect, and Block Duration of the Transversus Abdominis Plane Block

    DEFF Research Database (Denmark)

    Støving, Kion; Rothe, Christian; Rosenstock, Charlotte V

    2015-01-01

    BACKGROUND AND OBJECTIVES: The transversus abdominis plane (TAP) block is a widely used nerve block. However, basic block characteristics are poorly described. The purpose of this study was to assess the cutaneous sensory block area, muscle-relaxing effect, and block duration. METHODS: Sixteen...... healthy volunteers were randomized to receive an ultrasound-guided unilateral TAP block with 20 mL 7.5 mg/mL ropivacaine and placebo on the contralateral side. Measurements were performed at baseline and 90 minutes after performing the block. Cutaneous sensory block area was mapped and separated...... into a medial and lateral part by a vertical line through the anterior superior iliac spine. We measured muscle thickness of the 3 lateral abdominal muscle layers with ultrasound in the relaxed state and during maximal voluntary muscle contraction. The volunteers reported the duration of the sensory block...

  14. Characterization of the Organic Thin Film Solar Cells with Active Layers of PTB7/PC71BM Prepared by Using Solvent Mixtures with Different Additives

    Directory of Open Access Journals (Sweden)

    Masakazu Ito

    2014-01-01

    Full Text Available Organic thin film solar cells (OTFSCs were fabricated with blended active layers of poly[[4,8-bis[(2-ethylhexyloxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexylcarbonyl]thieno[3,4-b]thiophenediyl

  15. Isotope heating block

    International Nuclear Information System (INIS)

    Wenk, E.

    1976-01-01

    A suggestion is made not to lead the separated nuclear 'waste' from spent nuclear fuel elements directly to end storage, but to make use of the heat produced from the remaining radiation, e.g. for seawater desalination. According to the invention, the activated fission products are to be processed, e.g. by calcination or vitrification, so that one can handle them. They should then be arranged in layers alternately with plate-shaped heat conducting pipes to form a homogeneous block; the heat absorbed by the thermal plates should be further passed on to evaporators or heat exchangers. (UWI) [de

  16. Graphene Oxide as a Monoatomic Blocking Layer

    DEFF Research Database (Denmark)

    Petersen, Søren; Glyvradal, Magni; Bøggild, Peter

    2012-01-01

    Monolayer graphene oxide (mGO) is shown to effectively protect molecular thin films from reorganization and function as an atomically thin barrier for vapor-deposited Ti/Al metal top electrodes. Fragile organic Langmuir–Blodgett (LB) films of C22 fatty acid cadmium salts (cadmium(II) behenate) were...

  17. Internet of Things building blocks and business models

    CERN Document Server

    Hussain, Fatima

    2017-01-01

    This book describes the building blocks and introductory business models for Internet of Things (IoT). The author provide an overview of the entire IoT architecture and constituent layers, followed by detail description of each block . Various inter-connecting technologies and sensors are discussed in context of IoT networks. In addition to this, concepts of Big Data and Fog Computing are presented and characterized as per data generated by versatile IoT applications . Smart parking system and context aware services are presented as an hybrid model of cloud and Fog Afterwards, various IoT applications and respective business models are discussed. Finally, author summarizes the IoT building blocks and identify research issues in each, and suggest potential research projects worthy of pursuing. .

  18. An efficient, block-by-block algorithm for inverting a block tridiagonal, nearly block Toeplitz matrix

    International Nuclear Information System (INIS)

    Reuter, Matthew G; Hill, Judith C

    2012-01-01

    We present an algorithm for computing any block of the inverse of a block tridiagonal, nearly block Toeplitz matrix (defined as a block tridiagonal matrix with a small number of deviations from the purely block Toeplitz structure). By exploiting both the block tridiagonal and the nearly block Toeplitz structures, this method scales independently of the total number of blocks in the matrix and linearly with the number of deviations. Numerical studies demonstrate this scaling and the advantages of our method over alternatives.

  19. EnviroAtlas - Phoenix, AZ - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Phoenix, AZ EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  20. EnviroAtlas - Fresno, CA - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Fresno, CA EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  1. EnviroAtlas - Cleveland, OH - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Cleveland, OH EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded...

  2. Analysis of Block OMP using Block RIP

    OpenAIRE

    Wang, Jun; Li, Gang; Zhang, Hao; Wang, Xiqin

    2011-01-01

    Orthogonal matching pursuit (OMP) is a canonical greedy algorithm for sparse signal reconstruction. When the signal of interest is block sparse, i.e., it has nonzero coefficients occurring in clusters, the block version of OMP algorithm (i.e., Block OMP) outperforms the conventional OMP. In this paper, we demonstrate that a new notion of block restricted isometry property (Block RIP), which is less stringent than standard restricted isometry property (RIP), can be used for a very straightforw...

  3. Proposal to negotiate an amendment to an exisiting contract for the supply of additional Multi-layer Insulation (MLI) blankets for the LHC

    CERN Document Server

    2006-01-01

    This document concerns the proposal to negotiate an amendment to an existing contract for the supply of additional sets of MLI blankets. For the reasons explained in this document, the Finance Committee is invited to approve an amendment to an existing contract with JEHIER (FR) for the supply of additional MLI blanket sets for an amount of 1 020 000 euros (1 625 000 Swiss francs), bringing the total to a maximum amount of 8 954 359 euros (14 266 084 Swiss francs), subject to revision for inflation. The amounts in Swiss francs have been calculated using the present rate of exchange.

  4. Proposal to negotiate an amendment to an existing contract for the supply of additional Multi-Layer Insulation (MLI) blankets for the LHC

    CERN Document Server

    2005-01-01

    This document concerns the proposal to negotiate an amendment to an existing contract for the supply of additional sets of MLI blankets. For the reasons explained in this document, the Finance Committee is invited to approve an amendment to an existing contract with JEHIER (FR) for the supply of an additional 2 420 MLI blankets for an amount of 1 863 400 euros (2 909 513 Swiss francs), subject to revision for inflation, bringing the total to a maximum amount of 7 934 359 euros (12 388 708 Swiss francs), subject to revision for inflation. The amounts in Swiss francs have been calculated using the present rate of exchange.

  5. Block coordination copolymers

    Science.gov (United States)

    Koh, Kyoung Moo; Wong-Foy, Antek G; Matzger, Adam J; Benin, Annabelle I; Willis, Richard R

    2012-11-13

    The present invention provides compositions of crystalline coordination copolymers wherein multiple organic molecules are assembled to produce porous framework materials with layered or core-shell structures. These materials are synthesized by sequential growth techniques such as the seed growth technique. In addition, the invention provides a simple procedure for controlling functionality.

  6. Bullet-Block Science Video Puzzle

    Science.gov (United States)

    Shakur, Asif

    2015-01-01

    A science video blog, which has gone viral, shows a wooden block shot by a vertically aimed rifle. The video shows that the block hit dead center goes exactly as high as the one shot off-center. (Fig. 1). The puzzle is that the block shot off-center carries rotational kinetic energy in addition to the gravitational potential energy. This leads a…

  7. SNUPPS power block engineering

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, C A [Bechtel Power Corp., San Francisco, Calif. (USA)

    1975-11-01

    The Standard Power Block is based on a modular concept and consists of the following: turbine building, auxiliary building, fuel building, control building, radwaste building, diesel generators building, and outside storage tanks and transformers. Each power block unit includes a Westinghouse pressurized water reactor and has a thermal power rating of 3425 MW(t). The corresponding General Electric turbine generator net electrical output is 1188 MW(e). This standardization approach results in not only a reduction in the costs of engineering, licensing, procurement, and project planning, but should also result in additional savings by the application of experience gained in the construction of the first unit to the following units and early input of construction data to design.

  8. Southern Hemisphere Additional Ozonesondes (SHADOZ) Ozone Climatology (2005-2009): Tropospheric and Tropical Tropopause Layer (TTL) Profiles with Comparisons to Omi-based Ozone Products

    Science.gov (United States)

    Thompson, Anne M.; Miller, Sonya K.; Tilmes, Simone; Kollonige, Debra W.; Witte, Jacquelyn C.; Oltmans, Samuel J.; Johnson, Brian J.; Fujiwara, Masatomo; Schmidlin, F. J.; Coetzee, G. J. R.; hide

    2012-01-01

    We present a regional and seasonal climatology of SHADOZ ozone profiles in the troposphere and tropical tropopause layer (TTL) based on measurements taken during the first five years of Aura, 2005-2009, when new stations joined the network at Hanoi, Vietnam; Hilo, Hawaii; Alajuela Heredia, Costa Rica; Cotonou, Benin. In all, 15 stations operated during that period. A west-to-east progression of decreasing convective influence and increasing pollution leads to distinct tropospheric ozone profiles in three regions: (1) western Pacific eastern Indian Ocean; (2) equatorial Americas (San Cristobal, Alajuela, Paramaribo); (3) Atlantic and Africa. Comparisons in total ozone column from soundings, the Ozone Monitoring Instrument (OMI, on Aura, 2004-) satellite and ground-based instrumentation are presented. Most stations show better agreement with OMI than they did for EPTOMS comparisons (1998-2004; Earth-ProbeTotal Ozone Mapping Spectrometer), partly due to a revised above-burst ozone climatology. Possible station biases in the stratospheric segment of the ozone measurement noted in the first 7 years of SHADOZ ozone profiles are re-examined. High stratospheric bias observed during the TOMS period appears to persist at one station. Comparisons of SHADOZ tropospheric ozone and the daily Trajectory-enhanced Tropospheric Ozone Residual (TTOR) product (based on OMIMLS) show that the satellite-derived column amount averages 25 low. Correlations between TTOR and the SHADOZ sondes are quite good (typical r2 0.5-0.8), however, which may account for why some published residual-based OMI products capture tropospheric interannual variability fairly realistically. On the other hand, no clear explanations emerge for why TTOR-sonde discrepancies vary over a wide range at most SHADOZ sites.

  9. Ultrasound guided supraclavicular block.

    LENUS (Irish Health Repository)

    Hanumanthaiah, Deepak

    2013-09-01

    Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

  10. Alteration effect of the PGFsub(2α) inhibition on the 3H-norepinephrine release caused by α2 receptor blocking, sodium loading and 4-aminopyridine addition in isolated pulmonary arteries of rabbit

    International Nuclear Information System (INIS)

    Bunyevacs, Zs.; Toeroek, T.; Hadhazy, P.; Magyar, K.; Feher, L.; Vizi, E.Sz.

    1983-01-01

    The tritium labelled norepinephrine release was measured in isolated pulmonary artery of rabbit. If the 3 H-norepinephrine release was induced by nerves stimulated with electric current, the PGFsub(2α) inhibited the release by 62%. In the presence of Yohimbin the inhibitory effect of FGFsub(2α) was increased to 78.8%. If the Na + pump activity was reduced by potassium-free medium the PGFsub(2α) inhibition remained at 62%. In the presence of 4-aminopyridine the potassium channel was blocked and the PGFsub(2α) inhibition decreased to 32.1%. The endogen prostaglandin may serve as a modulator of the neurotransmitter release. (L.G.)

  11. High-Tg Polynorbornene-Based Block and Random Copolymers for Butanol Pervaporation Membranes

    Science.gov (United States)

    Register, Richard A.; Kim, Dong-Gyun; Takigawa, Tamami; Kashino, Tomomasa; Burtovyy, Oleksandr; Bell, Andrew

    Vinyl addition polymers of substituted norbornene (NB) monomers possess desirably high glass transition temperatures (Tg); however, until very recently, the lack of an applicable living polymerization chemistry has precluded the synthesis of such polymers with controlled architecture, or copolymers with controlled sequence distribution. We have recently synthesized block and random copolymers of NB monomers bearing hydroxyhexafluoroisopropyl and n-butyl substituents (HFANB and BuNB) via living vinyl addition polymerization with Pd-based catalysts. Both series of polymers were cast into the selective skin layers of thin film composite (TFC) membranes, and these organophilic membranes investigated for the isolation of n-butanol from dilute aqueous solution (model fermentation broth) via pervaporation. The block copolymers show well-defined microphase-separated morphologies, both in bulk and as the selective skin layers on TFC membranes, while the random copolymers are homogeneous. Both block and random vinyl addition copolymers are effective as n-butanol pervaporation membranes, with the block copolymers showing a better flux-selectivity balance. While polyHFANB has much higher permeability and n-butanol selectivity than polyBuNB, incorporating BuNB units into the polymer (in either a block or random sequence) limits the swelling of the polyHFANB and thereby improves the n-butanol pervaporation selectivity.

  12. High Temperature, Low Relative Humidity, Polymer-type Membranes Based on Disulfonated Poly(arylene ether) Block and Random Copolymers Optionally Incorporating Protonic Conducting Layered Water insoluble Zirconium Fillers

    Energy Technology Data Exchange (ETDEWEB)

    McGrath, James E.; Baird, Donald G.

    2010-06-03

    hydrophobic segments. If, like in Nafion, connectivity is established between the hydrophilic domains in these multiblock copolymers, they will not need as much water, and hence will show much better protonic conductivity than the random copolymers (with similar degree of sulfonation, or IEC) at partially hydrated conditions. The goal of this research is to develop a material suitable for use as a polymer electrolyte membrane which by the year 2010 will meet all the performance requirements associated with fuel cell operation at high temperatures and low relative humidity, and will out-perform the present standard Nafion{reg_sign}. In particular, it is our objective to extend our previous research based on the use of thermally, oxidatively, and hydrolytically, ductile, high Tg ion containing polymers based on poly(arylene ethers) to the production of polymer electrolyte membranes which will meet all the performance requirements in addition to having an areal resistance of < 0.05 ohm-cm{sup 2} at a temperature of up to 120 C, relative humidity of 25 to 50%, and up to 2.5 atm total pressure. In many instances, our materials already out performs Nafion{reg_sign}, and it is expected that with some modification by either combining with conductive inorganic fillers and/or synthesizing as a block copolymer it will meet the performance criteria at high temperatures and low relative humidity. A key component in improving the performance of the membranes (and in particular proton conductivity) and meeting the cost requirements of $40/m{sup 2} is our development of a film casting process, which shows promise for generation of void free thin films of uniform thickness with controlled polymer alignment and configuration.

  13. Homogeneous bilateral block shifts

    Indian Academy of Sciences (India)

    Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

  14. Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

    Directory of Open Access Journals (Sweden)

    Pierre Boufflet

    2016-10-01

    Full Text Available The microstructure of the active blend layer has been shown to be a critically important factor in the performance of organic solar devices. Block copolymers provide a potentially interesting avenue for controlling this active layer microstructure in solar cell blends. Here we explore the impact of backbone fluorination in block copolymers of poly(3-octyl-4-fluorothiophenes and poly(3-octylthiophene (F-P3OT-b-P3OT. Two block co-polymers with varying block lengths were prepared via sequential monomer addition under Kumada catalyst transfer polymerisation (KCTP conditions. We compare the behavior of the block copolymer to that of the corresponding homopolymer blends. In both types of system, we find the fluorinated segments tend to dominate the UV–visible absorption and molecular vibrational spectral features, as well as the thermal behavior. In the block copolymer case, non-fluorinated segments appear to slightly frustrate the aggregation of the more fluorinated block. However, in situ temperature dependent Raman spectroscopy shows that the intramolecular order is more thermally stable in the block copolymer than in the corresponding blend, suggesting that such materials may be interesting for enhanced thermal stability of organic photovoltaic active layers based on similar systems.

  15. Testing block subdivision algorithms on block designs

    Science.gov (United States)

    Wiseman, Natalie; Patterson, Zachary

    2016-01-01

    Integrated land use-transportation models predict future transportation demand taking into account how households and firms arrange themselves partly as a function of the transportation system. Recent integrated models require parcels as inputs and produce household and employment predictions at the parcel scale. Block subdivision algorithms automatically generate parcel patterns within blocks. Evaluating block subdivision algorithms is done by way of generating parcels and comparing them to those in a parcel database. Three block subdivision algorithms are evaluated on how closely they reproduce parcels of different block types found in a parcel database from Montreal, Canada. While the authors who developed each of the algorithms have evaluated them, they have used their own metrics and block types to evaluate their own algorithms. This makes it difficult to compare their strengths and weaknesses. The contribution of this paper is in resolving this difficulty with the aim of finding a better algorithm suited to subdividing each block type. The proposed hypothesis is that given the different approaches that block subdivision algorithms take, it's likely that different algorithms are better adapted to subdividing different block types. To test this, a standardized block type classification is used that consists of mutually exclusive and comprehensive categories. A statistical method is used for finding a better algorithm and the probability it will perform well for a given block type. Results suggest the oriented bounding box algorithm performs better for warped non-uniform sites, as well as gridiron and fragmented uniform sites. It also produces more similar parcel areas and widths. The Generalized Parcel Divider 1 algorithm performs better for gridiron non-uniform sites. The Straight Skeleton algorithm performs better for loop and lollipop networks as well as fragmented non-uniform and warped uniform sites. It also produces more similar parcel shapes and patterns.

  16. Coastal protection using topological interlocking blocks

    Science.gov (United States)

    Pasternak, Elena; Dyskin, Arcady; Pattiaratchi, Charitha; Pelinovsky, Efim

    2013-04-01

    The coastal protection systems mainly rely on the self-weight of armour blocks to ensure its stability. We propose a system of interlocking armour blocks, which form plate-shape assemblies. The shape and the position of the blocks are chosen in such a way as to impose kinematic constraints that prevent the blocks from being removed from the assembly. The topological interlocking shapes include simple convex blocks such as platonic solids, the most practical being tetrahedra, cubes and octahedra. Another class of topological interlocking blocks is so-called osteomorphic blocks, which form plate-like assemblies tolerant to random block removal (almost 25% of blocks need to be removed for the assembly to loose integrity). Both classes require peripheral constraint, which can be provided either by the weight of the blocks or post-tensioned internal cables. The interlocking assemblies provide increased stability because lifting one block involves lifting (and bending) the whole assembly. We model the effect of interlocking by introducing an equivalent additional self-weight of the armour blocks. This additional self-weight is proportional to the critical pressure needed to cause bending of the interlocking assembly when it loses stability. Using beam approximation we find an equivalent stability coefficient for interlocking. It is found to be greater than the stability coefficient of a structure with similar blocks without interlocking. In the case when the peripheral constraint is provided by the weight of the blocks and for the slope angle of 45o, the effective stability coefficient for a structure of 100 blocks is 33% higher than the one for a similar structure without interlocking. Further increase in the stability coefficient can be reached by a specially constructed peripheral constraint system, for instance by using post-tension cables.

  17. Poly(ferrocenylsilane)-block-Polylactide Block Copolymers

    NARCIS (Netherlands)

    Roerdink, M.; van Zanten, Thomas S.; Hempenius, Mark A.; Zhong, Zhiyuan; Feijen, Jan; Vancso, Gyula J.

    2007-01-01

    A PFS/PLA block copolymer was studied to probe the effect of strong surface interactions on pattern formation in PFS block copolymer thin films. Successful synthesis of PFS-b-PLA was demonstrated. Thin films of these polymers show phase separation to form PFS microdomains in a PLA matrix, and

  18. Block That Pain!

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Block That Pain! Past Issues / Fall 2007 Table of ... contrast, most pain relievers used for surgical procedures block activity in all types of neurons. This can ...

  19. Bundle Branch Block

    Science.gov (United States)

    ... known cause. Causes can include: Left bundle branch block Heart attacks (myocardial infarction) Thickened, stiffened or weakened ... myocarditis) High blood pressure (hypertension) Right bundle branch block A heart abnormality that's present at birth (congenital) — ...

  20. H-Seda: Partial Packet Recovery with Heterogeneous Block Sizes for Wireless Sensor Networks

    KAUST Repository

    Meer, Ammar M.

    2012-12-08

    Wireless sensor networks (WSN) have been largely used in various applications due to its ease of deployment and scalability. The throughput of such networks, however, suffers from high bit error rates mainly because of medium characteristics. Maximizing bandwidth utilization while maintaining low frame error rate has been an interesting problem. Frame fragmentation into small blocks with dedicated error detection codes per block can reduce the unnecessary retransmission of the correctly received blocks. The optimal block size, however, varies based on the wireless channel conditions. In addition, blocks within a frame can have different optimal sizes based on the variations on interference patterns. This thesis studies two dynamic partial packet recovery approaches experimentally over several interference intensities with various transmission-power levels. It also proposes a dynamic data link layer protocol: Hybrid Seda (H-Seda). H-Seda effectively addresses the challenges associated with dynamic partitioning of blocks while taking the observed error patterns into consideration. The design of H-Seda is discussed in details and compared to other previous approaches, namely Seda+ and Seda. The implementation of H-Seda shows substantial enhancements over fixed-size partial packet recovery protocols, achieving up to 2.5x improvement in throughput when the channel condition is noisy, while delay experienced decreases to only 14 % of the delay observed in Seda. On average, it shows 35% gain in goodput across all channel conditions used in our experiments. This significant improvement is due to the selective nature of H-Seda which minimizes retransmission overhead by selecting the appropriate number of blocks in each data frame. Additionally, H-Seda successfully reduces block overhead by 50% through removing block number field reaching to better performance when channel conditions are identical.

  1. Backfilling of deposition tunnels, block alternative

    International Nuclear Information System (INIS)

    Keto, P.; Roennqvist, P.-E.

    2007-03-01

    This report presents a preliminary process description of backfilling the deposition tunnels with pre-compacted blocks consisting of a mixture of bentonite and ballast (30:70). The process was modified for the Finnish KBS-3V type repository assuming that the amount of spent fuel canisters disposed of yearly is 40. Backfilling blocks (400 x 300 x 300 mm) are prepared in a block production plant with a hydraulic press with an estimated production capacity of 840 blocks per day. Some of the blocks are modified further to fit the profile of the tunnel roof. Prior to the installation of the blocks, the deposition tunnel floor is levelled with a mixture of bentonite and ballast (15:85). The blocks are placed in the tunnel with a modified reach truck. Centrifugal pellet throwing equipment is used to fill the gap between the blocks and the rock surface with bentonite pellets. Based on a preliminary assessment, the average dry density achieved with block backfill is sufficient to fulfil the criteria set for the backfill in order to ensure long-term safety and radiation protection. However, there are uncertainties concerning saturation, homogenisation, erosion, piping and self-healing of the block backfill that need to be studied further with laboratory and field tests. In addition, development efforts and testing concerning block manufacturing and installation are required to verify the technical feasibility of the concept. (orig.)

  2. Generalized Block Failure

    DEFF Research Database (Denmark)

    Jönsson, Jeppe

    2015-01-01

    Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...... shows that no readily available tests with a well-defined substantial eccentricity have been performed. This paper presents theoretical and experimental work leading towards generalized block failure capacity methods. Simple combination of normal force, shear force and moment stress distributions along...... yield lines around the block leads to simple interaction formulas similar to other interaction formulas in the codes....

  3. On the AlxGa1-xN/AlyGa1-yN/AlxGa1-xN (x>y) p-electron blocking layer to improve the hole injection for AlGaN based deep ultraviolet light-emitting diodes

    Science.gov (United States)

    Chu, Chunshuang; Tian, Kangkai; Fang, Mengqian; Zhang, Yonghui; Li, Luping; Bi, Wengang; Zhang, Zi-Hui

    2018-01-01

    This work proposes the [0001] oriented AlGaN-based deep ultraviolet (DUV) light-emitting diode (LED) possessing a specifically designed p-electron blocking layer (p-EBL) to achieve the high internal quantum efficiency. Both electrons and holes can be efficiently injected into the active region by adopting the Al0.60Ga0.40N/Al0.50Ga0.50N/Al0.60Ga0.40N structured p-EBL, in which a p-Al0.50Ga0.50N layer is embedded into the p-EBL. Moreover, the impact of different thicknesses for the p-Al0.50Ga0.50N insertion layer on the hole and electron injections has also been investigated. Compared with the DUV LED with the bulk p-Al0.60Ga0.40N as the EBL, the proposed LED architectures improve the light output power if the thickness of the p-Al0.50Ga0.50N insertion layer is properly designed.

  4. 2,1,3-benzothiadiazole-5,6-dicarboxylic imide - A versatile building block for additive- and annealing-free processing of organic solar cells with effi ciencies exceeding 8%

    KAUST Repository

    Nielsen, Christian Bergenstof

    2014-12-15

    A new photoactive polymer comprising benzo[1,2-b:3,4-b′:5,6-d′]trithiophene and 2,1,3-benzothiadiazole-5,6-dicarboxylic imide is reported. The synthetic design allows for alkyl chains to be introduced on both electron-rich and electron-deficient components, which in turn allows for rapid optimization of the alkyl chain substitution pattern. Consequently, the optimized polymer shows a maximum efficiency of 8.3% in organic photovoltaic devices processed in commercially viable fashion without solvent additives, annealing, or device engineering.

  5. 2,1,3-benzothiadiazole-5,6-dicarboxylic imide - A versatile building block for additive- and annealing-free processing of organic solar cells with effi ciencies exceeding 8%

    KAUST Repository

    Nielsen, Christian Bergenstof; Ashraf, Raja Shahid; Treat, Neil D.; Schroeder, Bob C.; Donaghey, Jenny E.; White, Andrew J P; Stingelin, Natalie; McCulloch, Iain

    2014-01-01

    A new photoactive polymer comprising benzo[1,2-b:3,4-b′:5,6-d′]trithiophene and 2,1,3-benzothiadiazole-5,6-dicarboxylic imide is reported. The synthetic design allows for alkyl chains to be introduced on both electron-rich and electron-deficient components, which in turn allows for rapid optimization of the alkyl chain substitution pattern. Consequently, the optimized polymer shows a maximum efficiency of 8.3% in organic photovoltaic devices processed in commercially viable fashion without solvent additives, annealing, or device engineering.

  6. Modulation of solid electrolyte interphase of lithium-ion batteries by LiDFOB and LiBOB electrolyte additives

    Science.gov (United States)

    Huang, Shiqiang; Wang, Shuwei; Hu, Guohong; Cheong, Ling-Zhi; Shen, Cai

    2018-05-01

    Solid-electrolyte interphase (SEI) layer is an organic-inorganic composite layer that allows Li+ transport across but blocks electron flow across and prevents solvent diffusing to electrode surface. Morphology, thickness, mechanical and chemical properties of SEI are important for safety and cycling performance of lithium-ion batteries. Herein, we employ a combination of in-situ AFM and XPS to investigate the effects of two electrolyte additives namely lithium difluoro(oxalate)borate (LiDFOB) and lithium bis(oxalato)borate (LiBOB) on SEI layer. LiDFOB is found to result in a thin but hard SEI layer containing more inorganic species (LiF and LiCO3); meanwhile LiBOB promotes formation of a thick but soft SEI layer containing more organic species such as ROCO2Li. Findings from present study will help development of electrolyte additives that promote formation of good SEI layer.

  7. Blocked Randomization with Randomly Selected Block Sizes

    Directory of Open Access Journals (Sweden)

    Jimmy Efird

    2010-12-01

    Full Text Available When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  8. 31 CFR 595.301 - Blocked account; blocked property.

    Science.gov (United States)

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM SANCTIONS REGULATIONS General Definitions § 595.301 Blocked account; blocked property. The terms blocked account and blocked...

  9. The Adobe Photoshop layers book

    CERN Document Server

    Lynch, Richard

    2011-01-01

    Layers are the building blocks for working in Photoshop. With the correct use of the Layers Tool, you can edit individual components of your images nondestructively to ensure that your end result is a combination of the best parts of your work. Despite how important it is for successful Photoshop work, the Layers Tool is one of the most often misused and misunderstood features within this powerful software program. This book will show you absolutely everything you need to know to work with layers, including how to use masks, blending, modes and layer management. You'll learn professional tech

  10. PLSS Townships and Sections, This layer is kept up-to-date with the addition of new survey data, as the data comes in. We have all known data incorporated, but there still remains about 40% of the County that needs more work., Published in 2013, Not Applicable scale, Chippewa County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — PLSS Townships and Sections dataset current as of 2013. This layer is kept up-to-date with the addition of new survey data, as the data comes in. We have all known...

  11. Polystyrene-block-Poly(ionic liquid) Copolymers as Work Function Modifiers in Inverted Organic Photovoltaic Cells.

    Science.gov (United States)

    Park, Jong Baek; Isik, Mehmet; Park, Hea Jung; Jung, In Hwan; Mecerreyes, David; Hwang, Do-Hoon

    2018-02-07

    Interfacial layers play a critical role in building up the Ohmic contact between electrodes and functional layers in organic photovoltaic (OPV) solar cells. These layers are based on either inorganic oxides (ZnO and TiO 2 ) or water-soluble organic polymers such as poly[(9,9-dioctyl-2,7-fluorene)-alt-(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)] and polyethylenimine ethoxylated (PEIE). In this work, we have developed a series of novel poly(ionic liquid) nonconjugated block copolymers for improving the performance of inverted OPV cells by using them as work function modifiers of the indium tin oxide (ITO) cathode. Four nonconjugated polyelectrolytes (n-CPEs) based on polystyrene and imidazolium poly(ionic liquid) (PSImCl) were synthesized by reversible addition-fragmentation chain transfer polymerization. The ratio of hydrophobic/hydrophilic block copolymers was varied depending on the ratio of polystyrene to the PSImCl block. The ionic density, which controls the work function of the electrode by forming an interfacial dipole between the electrode and the block copolymers, was easily tuned by simply changing the PSImCl molar ratio. The inverted OPV device with the ITO/PS 29 -b-PSImCl 60 cathode achieved the best power conversion efficiency (PCE) of 7.55% among the synthesized block copolymers, exhibiting an even higher PCE than that of the reference OPV device with PEIE (7.30%). Furthermore, the surface properties of the block copolymers films were investigated by contact angle measurements to explore the influence of the controlled hydrophobic/hydrophilic characters on the device performances.

  12. Addition of an indoleamine 2,3,-dioxygenase inhibitor to B cell-depletion therapy blocks autoreactive B cell activation and recurrence of arthritis in K/BxN mice.

    Science.gov (United States)

    Pigott, Elizabeth; Mandik-Nayak, Laura

    2012-07-01

    To define the role of indoleamine 2,3-dioxygenase (IDO) in driving pathogenic B cell responses that lead to arthritis and to determine if inhibitors of the IDO pathway can be used in conjunction with therapeutic B cell depletion to prevent the reemergence of autoantibodies and arthritis following reconstitution of the B cell repertoire. Immunoglobulin-transgenic mice were treated with the IDO inhibitor 1-methyltryptophan (1-MT) and monitored for the extent of autoreactive B cell activation. Arthritic K/BxN mice were treated with B cell depletion alone or in combination with 1-MT. Mice were monitored for the presence of autoantibody-secreting cells, inflammatory cytokines, and joint inflammation. Treatment with 1-MT did not affect the initial activation or survival of autoreactive B cells, but it did inhibit their ability to differentiate into autoantibody-secreting cells. Treatment with anti-CD20 depleted the B cell repertoire and attenuated arthritis symptoms; however, the arthritis symptoms rapidly returned as B cells repopulated the repertoire. Administration of 1-MT prior to B cell repopulation prevented the production of autoantibodies and inflammatory cytokines and flare of arthritis symptoms. IDO activity is essential for the differentiation of autoreactive B cells into antibody-secreting cells, but it is not necessary for their initial stages of activation. Addition of 1-MT to therapeutic B cell depletion prevents the differentiation of autoantibody-secreting cells and the recurrence of autoimmune arthritis following reconstitution of the B cell repertoire. These data suggest that IDO inhibitors could be used in conjunction with B cell depletion as an effective cotherapeutic strategy in the treatment of rheumatoid arthritis. Copyright © 2012 by the American College of Rheumatology.

  13. Lateral femoral cutaneous nerve block after total hip arthroplasty

    DEFF Research Database (Denmark)

    Thybo, K H; Mathiesen, O; Dahl, J B

    2016-01-01

    in this prospective, randomised, blinded, placebo-controlled trial. Group A received an LFCN block with 8 ml of 0.75% ropivacaine followed after 45 min by an additional LFCN block with 8 ml of saline. Group B received an LFCN block with 8 ml of saline followed after 45 min by an additional LFCN block with 8 ml of 0.......75% ropivacaine. RESULTS: We found a difference of 17 mm (95% CI, 4-31 mm; P

  14. Nanosized amorphous calcium carbonate stabilized by poly(ethylene oxide)-b-poly(acrylic acid) block copolymers.

    Science.gov (United States)

    Guillemet, Baptiste; Faatz, Michael; Gröhn, Franziska; Wegner, Gerhard; Gnanou, Yves

    2006-02-14

    Particles of amorphous calcium carbonate (ACC), formed in situ from calcium chloride by the slow release of carbon dioxide by alkaline hydrolysis of dimethyl carbonate in water, are stabilized against coalescence in the presence of very small amounts of double hydrophilic block copolymers (DHBCs) composed of poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA) blocks. Under optimized conditions, spherical particles of ACC with diameters less than 100 nm and narrow size distribution are obtained at a concentration of only 3 ppm of PEO-b-PAA as additive. Equivalent triblock or star DHBCs are compared to diblock copolymers. The results are interpreted assuming an interaction of the PAA blocks with the surface of the liquid droplets of the concentrated CaCO3 phase, formed by phase separation from the initially homogeneous reaction mixture. The adsorption layer of the block copolymer protects the liquid precursor of ACC from coalescence and/or coagulation.

  15. Block Cipher Analysis

    DEFF Research Database (Denmark)

    Miolane, Charlotte Vikkelsø

    ensurethat no attack violatesthe securitybounds specifiedbygeneric attack namely exhaustivekey search and table lookup attacks. This thesis contains a general introduction to cryptography with focus on block ciphers and important block cipher designs, in particular the Advanced Encryption Standard(AES...... on small scale variants of AES. In the final part of the thesis we present a new block cipher proposal Present and examine its security against algebraic and differential cryptanalysis in particular....

  16. BTP: a Block Transfer Protocol for Delay Tolerant Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Hansen, Morten Tranberg; Biagioni, Edoardo S.

    2010-01-01

    Wireless sensor networks that are energy-constrained must transmit and receive data as efficiently as possible.  If the transmission is delay tolerant, transferring blocks of accumulated data can be more efficient than transferring each sensed measurement as soon as it is available.  This paper...... proposes a Block Transfer Protocol (BTP) designed for efficient and reliable transmission in wireless sensor networks.  BTP reduces the time it takes to reliably transfer a block of packets compared to conventional link layer protocols, by piggybacking in data packets information about the transfer......, minimizing the number of acknowledgements needed for reliable transmission, and reducing the need for timeouts, which can substantially slow down communication when transmission is unreliable.  In addition, BTP improves reliability by handling false positive acknowledgements and by letting the receivers...

  17. EnviroAtlas - New York, NY - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the New York, NY EnviroAtlas community. The block groups are from the US Census Bureau and are included/excluded based...

  18. Related Drupal Nodes Block

    NARCIS (Netherlands)

    Van der Vegt, Wim

    2010-01-01

    Related Drupal Nodes Block This module exposes a block that uses Latent Semantic Analysis (Lsa) internally to suggest three nodes that are relevant to the node a user is viewing. This module performs three tasks. 1) It periodically indexes a Drupal site and generates a Lsa Term Document Matrix.

  19. Designers Block 2002

    DEFF Research Database (Denmark)

    Dickson, Thomas

    2002-01-01

    Artiklen indleder med: ved siden aaf Londons etablerede designmesse '100% Design', er der vokset et undergrundsmiljø af designudstillinger op. Det dominerende og mest kendte initiativ er Designers Block, der i år udstillede to steder i byen. Designers Block er et mere uformelt udstillingsforum...

  20. S-layer architectures : extending the morphogenetic potential of S-layer protein self-assembly

    International Nuclear Information System (INIS)

    Schuster, D.

    2013-01-01

    Self-assembly of molecular building blocks is a common principle for bottom up based building principles in nature. One example are crystalline bacterial surface layers, termed S-layers, which are the most commonly observed cell surface structures in prokaryotic organisms. They recrystallize into highly ordered, porous protein meshworks with unit cell sizes of 3 to 30 nm and pore sizes of 2 to 8 nm. In this work, S-layers were self-assembled on various three dimensional scaffolds in order to fabricate novel S-layer architectures. Exploiting the stabilizing effect of silica deposited on the S-layer protein meshwork led to the construction of hollow S-layer nano-containers derived from coated liposomes. Transmission electron microscopy (TEM) techniques and release experiments with fluorescent dyes confirmed the dissolution of the supporting lipids. Silica deposition on different spherical particles in solution, as well as on planar S-layer coated surfaces, could be monitored by measuring the ζ-potential, the decline of monosilicic acid in solution, by using scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis or by quartz crystal microbalance with dissipation monitoring (QCM-D). Both, ζ-potential and release experiments showed differences between silicified plain liposomes and silicified S-layer coated liposomes. In addition, nanocapsules with calcium carbonate cores served as another template for the construction of silica supported S-layer architectures. These were investigated by SEM and fluorescence microscopy after fluorescence labeling. Additional coating with polyelectrolytes increased the stability of the nanocapsules. Their mechanical properties were characterized by atomic force microscopy (AFM). The influence of silica deposition was investigated by AFM and SEM. Further on, emulsomes and gas filled lipid supported microbubbles may serve as other templates for the design of spherical protein constructs although extraction of the

  1. Additive manufacturing.

    Science.gov (United States)

    Mumith, A; Thomas, M; Shah, Z; Coathup, M; Blunn, G

    2018-04-01

    Increasing innovation in rapid prototyping (RP) and additive manufacturing (AM), also known as 3D printing, is bringing about major changes in translational surgical research. This review describes the current position in the use of additive manufacturing in orthopaedic surgery. Cite this article: Bone Joint J 2018;100-B:455-60.

  2. Food additives

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Food additives URL of this page: //medlineplus.gov/ency/article/ ...

  3. Contributions of hard and soft blocks in the self-healing of metal-ligand-containing block copolymers

    NARCIS (Netherlands)

    Bose, Ranjita K.; Enke, Marcel; Grande, Antonio M.; Zechel, Stefan; Schacher, Felix H.; Hager, Martin D.; Garcia, Santiago J.; Schubert, Ulrich S.; van der Zwaag, Sybrand

    2017-01-01

    The main aim of this work is to study the respective contribution of the hard and soft blocks of a metal-ligand containing block copolymer to the self-healing behavior. To this aim, different block copolymers containing terpyridine were synthesized using reversible addition-fragmentation chain

  4. Contributions of hard and soft blocks in the self-healing of metal-ligand-containing block copolymers

    NARCIS (Netherlands)

    Bose, R.K.; Enke, Marcel; Grande, A.M.; Zechel, Stefan; Schacher, Felix H.; Hager, Martin D.; Garcia Espallargas, Santiago J.; Schubert, Ulrich S.; van der Zwaag, S.

    2017-01-01

    The main aim of this work is to study the respective contribution of the hard and soft blocks of a metal-ligand containing block copolymer to the self-healing behavior. To this aim, different block copolymers containing terpyridine were synthesized using reversible addition-fragmentation chain

  5. 31 CFR 594.301 - Blocked account; blocked property.

    Science.gov (United States)

    2010-07-01

    ... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY GLOBAL TERRORISM SANCTIONS REGULATIONS General Definitions § 594.301 Blocked account; blocked property. The terms blocked account and...

  6. RX for Writer's Block.

    Science.gov (United States)

    Tompkins, Gail E.; Camp, Donna J.

    1988-01-01

    Describes four prewriting techniques that elementary and middle grade students can use to gather and organize ideas for writing, and by so doing, cure writer's block. Techniques discussed are: (1) brainstorming; (2) clustering; (3) freewriting; and (4) cubing.

  7. Block copolymer battery separator

    Science.gov (United States)

    Wong, David; Balsara, Nitash Pervez

    2016-04-26

    The invention herein described is the use of a block copolymer/homopolymer blend for creating nanoporous materials for transport applications. Specifically, this is demonstrated by using the block copolymer poly(styrene-block-ethylene-block-styrene) (SES) and blending it with homopolymer polystyrene (PS). After blending the polymers, a film is cast, and the film is submerged in tetrahydrofuran, which removes the PS. This creates a nanoporous polymer film, whereby the holes are lined with PS. Control of morphology of the system is achieved by manipulating the amount of PS added and the relative size of the PS added. The porous nature of these films was demonstrated by measuring the ionic conductivity in a traditional battery electrolyte, 1M LiPF.sub.6 in EC/DEC (1:1 v/v) using AC impedance spectroscopy and comparing these results to commercially available battery separators.

  8. Blocking in Category Learning

    OpenAIRE

    Bott, Lewis; Hoffman, Aaron B.; Murphy, Gregory L.

    2007-01-01

    Many theories of category learning assume that learning is driven by a need to minimize classification error. When there is no classification error, therefore, learning of individual features should be negligible. We tested this hypothesis by conducting three category learning experiments adapted from an associative learning blocking paradigm. Contrary to an error-driven account of learning, participants learned a wide range of information when they learned about categories, and blocking effe...

  9. Theory of circuit block switch-off

    Directory of Open Access Journals (Sweden)

    S. Henzler

    2004-01-01

    Full Text Available Switching-off unused circuit blocks is a promising approach to supress static leakage currents in ultra deep sub-micron CMOS digital systems. Basic performance parameters of Circuit Block Switch-Off (CBSO schemes are defined and their dependence on basic circuit parameters is estimated. Therefore the design trade-off between strong leakage suppression in idle mode and adequate dynamic performance in active mode can be supported by simple analytic investigations. Additionally, a guideline for the estimation of the minimum time for which a block deactivation is useful is derived.

  10. Round Gating for Low Energy Block Ciphers

    DEFF Research Database (Denmark)

    Banik, Subhadeep; Bogdanov, Andrey; Regazzoni, Francesco

    2016-01-01

    design techniques for implementing block ciphers in a low energy fashion. We concentrate on round based implementation and we discuss how gating, applied at round level can affect and improve the energy consumption of the most common lightweight block cipher currently used in the internet of things....... Additionally, we discuss how to needed gating wave can be generated. Experimental results show that our technique is able to reduce the energy consumption in most block ciphers by over 60% while incurring only a minimal overhead in hardware....

  11. Análise experimental de blocos intertravados de concreto com adição de resíduos do processo de recauchutagem de pneus = Analysis of experimental interlocking blocks of concrete with addition of residues of process the tires retreading production

    Directory of Open Access Journals (Sweden)

    Cesar Fabiano Fioriti

    2010-07-01

    Full Text Available Com o aumento da população nos últimos anos, a indústria de modo geral tem se adequado à demanda resultante. A indústria do processo de recauchutagem de pneus gera resíduos que em sua maioria têm sido descartados sem nenhum controle. Este fato contribui para aumentar a poluição ambiental e favorecer a proliferação de vetores nocivos àsaúde. Visando encontrar uma aplicação para esse tipo de resíduo, neste trabalho serão apresentados resultados experimentais de blocos intertravados para pavimentos de concreto, com traços adicionados de resíduos de pneus. Foram confeccionados blocos intertravados em que se determinou, por meio de ensaios laboratoriais, a necessidade de se fixar o traço que desse maior retorno quanto às características analisadas. Verificaram-se quatro tipos de traços de concreto com resíduos de pneus. Procedeu-se aos ensaios de resistência mecânicaà compressão, absorção de água e resistência ao impacto. Pelos resultados preliminares obtidos, verificou-se que são satisfatórios, confirmando-se a possibilidade de aplicação desse tipo de bloco intertravado em ambientes com solicitações baixas, o que traria, além da economia das fontes naturais de agregados, benefícios ecológicos pela reutilização dos resíduos da recauchutagem de pneus.With the population growth in recent years, industry in general has ajusted itself to resulting demand. the industry of tire retreading generates residues that have been discarded without any control. this adds to environmental pollution and promotes the proliferation of vectors harmful to health. aiming to find an application for this type of residues, this study presents experimental results to interlocking concrete block pavements, with addition of residuestires. interlocking blocks were built up and we determined, through laboratory tests, the need to set the mark that provide greater return regarding analyzed characteristics. there are four types of dosage

  12. Uniaxial backfill block compaction

    International Nuclear Information System (INIS)

    Koskinen, V.

    2012-05-01

    The main parts of the project were: to make a literature survey of the previous uniaxial compaction experiments; do uniaxial compaction tests in laboratory scale; and do industrial scale production tests. Object of the project was to sort out the different factors affecting the quality assurance chain of the backfill block uniaxial production and solve a material sticking to mould problem which appeared during manufacturing the blocks of bentonite and cruched rock mixture. The effect of mineralogical and chemical composition on the long term functionality of the backfill was excluded from the project. However, the used smectite-rich clays have been tested for mineralogical consistency. These tests were done in B and Tech OY according their SOPs. The objective of the Laboratory scale tests was to find right material- and compaction parameters for the industrial scale tests. Direct comparison between the laboratory scale tests and industrial scale tests is not possible because the mould geometry and compaction speed has a big influence for the compaction process. For this reason the selected material parameters were also affected by the previous compaction experiments. The industrial scale tests were done in summer of 2010 in southern Sweden. Blocks were done with uniaxial compaction. A 40 tons of the mixture of bentonite and crushed rock blocks and almost 50 tons of Friedland-clay blocks were compacted. (orig.)

  13. Impression block with orientator

    International Nuclear Information System (INIS)

    Brilin, V I; Ulyanova, O S

    2015-01-01

    Tool review, namely the impression block, applied to check the shape and size of the top of fish as well as to determine the appropriate tool for fishing operation was realized. For multiple application and obtaining of the impress depth of 3 cm and more, the standard volumetric impression blocks with fix rods are used. However, the registered impress of fish is not oriented in space and the rods during fishing are in the extended position. This leads to rods deformation and sinking due to accidental impacts of impression block over the borehole irregularity and finally results in faulty detection of the top end of fishing object in hole. The impression blocks with copy rods and fixed magnetic needle allow estimating the object configuration and fix the position of magnetic needle determining the position of the top end of object in hole. However, the magnetic needle fixation is realized in staged and the rods are in extended position during fishing operations as well as it is in standard design. The most efficient tool is the impression block with copy rods which directs the examined object in the borehole during readings of magnetic needles data from azimuth plate and averaging of readings. This significantly increases the accuracy of fishing toll direction. The rods during fishing are located in the body and extended only when they reach the top of fishing object

  14. Additive manufacturing of metals

    International Nuclear Information System (INIS)

    Herzog, Dirk; Seyda, Vanessa; Wycisk, Eric; Emmelmann, Claus

    2016-01-01

    Additive Manufacturing (AM), the layer-by layer build-up of parts, has lately become an option for serial production. Today, several metallic materials including the important engineering materials steel, aluminium and titanium may be processed to full dense parts with outstanding properties. In this context, the present overview article describes the complex relationship between AM processes, microstructure and resulting properties for metals. It explains the fundamentals of Laser Beam Melting, Electron Beam Melting and Laser Metal Deposition, and introduces the commercially available materials for the different processes. Thereafter, typical microstructures for additively manufactured steel, aluminium and titanium are presented. Special attention is paid to AM specific grain structures, resulting from the complex thermal cycle and high cooling rates. The properties evolving as a consequence of the microstructure are elaborated under static and dynamic loading. According to these properties, typical applications are presented for the materials and methods for conclusion.

  15. Caracterização Estrutural e da Capacidade de Absorção de Água em Bloco de Cimento com Adição de Resíduo de Pneu (Ecobloco = Water Absorption Capacity and Structural Characterization of Cement Block with Addition of Tire Residue (Ecobloco.

    Directory of Open Access Journals (Sweden)

    Maria da Conceição S. Gomes

    2007-12-01

    Full Text Available Foram feitos caracterizações estruturais com ensaios em corpo de prova, medidas granulométricas do resíduo, docimento, do pó de brita e da areia, e a medida da capacidade de absorção de água em blocos de cimento (chamados de ecoblocos com adição de 5%, 10%, 15%, 25% e 35% de resíduo de pneu, obtido por meio de raspagem de pneus automotivos inservíveis. A geometria de confecção dos ecoblocos foi projetada para serem encaixados no empilhamento vertical, requerendo o mínimo de massa de cimento para a confecção de parede de vedação. = Experiment for structural characterizations were made in test body as well as measurements of the capacity of water absorption in cement blocks (called ecoblocos with the addition of 5%, 10%, 15%, 25% and 35% of tire residue.These additions are obtained by means of worn out tire’s scratching. The ecoblocos´ design was projected for them to be inserted in the vertical piling up, requesting the minimum of mortar for the construction of walls.

  16. Integral-fuel blocks

    International Nuclear Information System (INIS)

    Cunningham, C.; Simpkin, S.D.

    1975-01-01

    A prismatic moderator block is described which has fuel-containing channels and coolant channels disposed parallel to each other and to edge faces of the block. The coolant channels are arranged in rows on an equilateral triangular lattice pattern and the fuel-containing channels are disposed in a regular lattice pattern with one fuel-containing channel between and equidistant from each of the coolant channels in each group of three mutually adjacent coolant channels. The edge faces of the block are parallel to the rows of coolant channels and the channels nearest to each edge face are disposed in two rows parallel thereto, with one of the rows containing only coolant channels and the other row containing only fuel-containing channels. (Official Gazette)

  17. Right bundle branch block

    DEFF Research Database (Denmark)

    Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse

    2013-01-01

    AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included...... in the Copenhagen City Heart Study examined in 1976-2003 free from previous myocardial infarction (MI), chronic heart failure, and left bundle branch block through registry linkage until 2009 for all-cause mortality and cardiovascular outcomes. The prevalence of RBBB/IRBBB was higher in men (1.4%/4.7% in men vs. 0.......5%/2.3% in women, P block was associated with significantly...

  18. Photocatalytic Nanostructuring of Graphene Guided by Block Copolymer Self-Assembly

    DEFF Research Database (Denmark)

    Wang, Zhongli; Li, Tao; Schulte, Lars

    2016-01-01

    graphene nanomesh was fabricated by photocatalysis of single-layer graphene suspended on top of TiO2-covered nanopillars, which were produced by combining block copolymer nanolithography with atomic layer deposition. Graphene nanoribbons were also prepared by the same method applied to a line-forming block...

  19. ["Habitual" left branch block alternating with 2 "disguised" bracnch block].

    Science.gov (United States)

    Lévy, S; Jullien, G; Mathieu, P; Mostefa, S; Gérard, R

    1976-10-01

    Two cases of alternating left bundle branch block and "masquerading block" (with left bundle branch morphology in the stnadard leads and right bundle branch block morphology in the precordial leads) were studied by serial tracings and his bundle electrocardiography. In case 1 "the masquerading" block was associated with a first degree AV block related to a prolongation of HV interval. This case is to our knowledge the first cas of alternating bundle branch block in which his bundle activity was recorded in man. In case 2, the patient had atrial fibrilation and His bundle recordings were performed while differents degrees of left bundle branch block were present: The mechanism of the alternation and the concept of "masquerading" block are discussed. It is suggested that this type of block represents a right bundle branch block associated with severe lesions of the "left system".

  20. E-Block: A Tangible Programming Tool with Graphical Blocks

    OpenAIRE

    Danli Wang; Yang Zhang; Shengyong Chen

    2013-01-01

    This paper designs a tangible programming tool, E-Block, for children aged 5 to 9 to experience the preliminary understanding of programming by building blocks. With embedded artificial intelligence, the tool defines the programming blocks with the sensors as the input and enables children to write programs to complete the tasks in the computer. The symbol on the programming block's surface is used to help children understanding the function of each block. The sequence information is transfer...

  1. Block Copolymers: Synthesis and Applications in Nanotechnology

    Science.gov (United States)

    Lou, Qin

    This study is focused on the synthesis and study of (block) copolymers using reversible deactivation radical polymerizations (RDRPs), including atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization. In particular, two primary areas of study are undertaken: (1) a proof-of-concept application of lithographic block copolymers, and (2) the mechanistic study of the deposition of titania into block copolymer templates for the production of well-ordered titania nanostructures. Block copolymers have the ability to undergo microphase separation, with an average size of each microphase ranging from tens to hundreds of nanometers. As such, block copolymers have been widely considered for nanotechnological applications over the past two decades. The development of materials for various nanotechnologies has become an increasingly studied area as improvements in many applications, such as those found in the semiconductor and photovoltaic industries are constantly being sought. Significant growth in developments of new synthetic methods ( i.e. RDRPs) has allowed the production of block copolymers with molecular (and sometimes atomic) definition. In turn, this has greatly expanded the use of block copolymers in nanotechnology. Herein, we describe the synthesis of statistical and block copolymers of 193 nm photolithography methacrylate and acrylate resist monomers with norbornyl and adamantyl moieties using RAFT polymerization.. For these resist (block) copolymers, the phase separation behaviors were examined by atomic force microscopy (AFM). End groups were removed from the polymers to avoid complications during the photolithography since RAFT end groups absorb visible light. Poly(glycidyl methacrylate-block-polystyrene) (PGMA-b-PS) was synthesize by ATRP and demonstrated that this block copolymer acts as both a lithographic UV (365 nm) photoresist and a self-assembly material. The PGMA segments can undergo cationic

  2. Linoleum Block Printing Revisited.

    Science.gov (United States)

    Chetelat, Frank J.

    1980-01-01

    The author discusses practical considerations of teaching linoleum block printing in the elementary grades (tool use, materials, motivation) and outlines a sequence of design concepts in this area for the primary, intermediate and junior high grades. A short list of books and audiovisual aids is appended. (SJL)

  3. Spice Blocks Melanoma Growth

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    Curcumin, the pungent yellow spice found in both turmeric and curry powders, blocks a key biological pathway needed for development of melanoma and other cancers, according to a study that appears in the journal Cancer. Researchers from The University of Texas M. D. Anderson Cancer Center demonstrate how curcumin stops laboratory strains of…

  4. Contaminated soil concrete blocks

    NARCIS (Netherlands)

    de Korte, A.C.J.; Brouwers, Jos; Limbachiya, Mukesh C.; Kew, Hsein Y.

    2009-01-01

    According to Dutch law the contaminated soil needs to be remediated or immobilised. The main focus in this article is the design of concrete blocks, containing contaminated soil, that are suitable for large production, financial feasible and meets all technical and environmental requirements. In

  5. Nanostructured Polysulfone-Based Block Copolymer Membranes

    KAUST Repository

    Xie, Yihui

    2016-01-01

    polycondensation and reversible addition-fragmentation chain-transfer polymerization. The obtained membrane has a highly porous interconnected skin layer composed of elongated micelles with a flower-like arrangement, on top of the graded finger-like macrovoids

  6. Arthroscopic medial meniscus trimming or repair under nerve blocks: Which nerves should be blocked?

    Science.gov (United States)

    Taha, AM; Abd-Elmaksoud, AM

    2016-01-01

    Background: This study aimed to determine the role of the sciatic and obturator nerve blocks (in addition to femoral block) in providing painless arthroscopic medial meniscus trimming/repair. Materials and Methods: One hundred and twenty patients with medial meniscus tear, who had been scheduled to knee arthroscopy, were planned to be included in this controlled prospective double-blind study. The patients were randomly allocated into three equal groups; FSO, FS, and FO. The femoral, sciatic, and obturator nerves were blocked in FSO groups. The femoral and sciatic nerves were blocked in FS group, while the femoral and obturator nerves were blocked in FO group. Intraoperative pain and its causative surgical maneuver were recorded. Results: All the patients (n = 7, 100%) in FO group had intraoperative pain. The research was terminated in this group but completed in FS and FSO groups (40 patients each). During valgus positioning of the knee for surgical management of the medial meniscus tear, the patients in FS group experienced pain more frequently than those in FSO group (P = 0.005). Conclusion: Adding a sciatic nerve block to the femoral nerve block is important for painless knee arthroscopy. Further adding of an obturator nerve block may be needed when a valgus knee position is required to manage the medial meniscus tear. PMID:27375382

  7. The Keck keyword layer

    Science.gov (United States)

    Conrad, A. R.; Lupton, W. F.

    1992-01-01

    Each Keck instrument presents a consistent software view to the user interface programmer. The view consists of a small library of functions, which are identical for all instruments, and a large set of keywords, that vary from instrument to instrument. All knowledge of the underlying task structure is hidden from the application programmer by the keyword layer. Image capture software uses the same function library to collect data for the image header. Because the image capture software and the instrument control software are built on top of the same keyword layer, a given observation can be 'replayed' by extracting keyword-value pairs from the image header and passing them back to the control system. The keyword layer features non-blocking as well as blocking I/O. A non-blocking keyword write operation (such as setting a filter position) specifies a callback to be invoked when the operation is complete. A non-blocking keyword read operation specifies a callback to be invoked whenever the keyword changes state. The keyword-callback style meshes well with the widget-callback style commonly used in X window programs. The first keyword library was built for the two Keck optical instruments. More recently, keyword libraries have been developed for the infrared instruments and for telescope control. Although the underlying mechanisms used for inter-process communication by each of these systems vary widely (Lick MUSIC, Sun RPC, and direct socket I/O, respectively), a basic user interface has been written that can be used with any of these systems. Since the keyword libraries are bound to user interface programs dynamically at run time, only a single set of user interface executables is needed. For example, the same program, 'xshow', can be used to display continuously the telescope's position, the time left in an instrument's exposure, or both values simultaneously. Less generic tools that operate on specific keywords, for example an X display that controls optical

  8. Tuning of Block Copolymer Membrane Morphology through Water Induced Phase Inversion Technique

    KAUST Repository

    Madhavan, Poornima

    2016-06-01

    Isoporous membranes are attractive for the regulation and detection of transport at the molecular level. A well-defined asymmetric membranes from diblock copolymers with an ordered nanoporous membrane morphologies were fabricated by the combination of block copolymer self-assembly and non-solvent-induced phase separation (NIPS) technique. This is a straightforward and fast one step procedure to develop integrally anisotropic (“asymmetric”) membranes having isoporous top selective layer. Membranes prepared via this method exhibit an anisotropic cross section with a thin separation layer supported from underneath a macroporous support. These membrane poses cylindrical pore structure with ordered nanopores across the entire membrane surfaces with pore size in the range from 20 to 40 nm. Tuning the pore morphology of the block copolymer membranes before and after fabrication are of great interest. In this thesis, we first investigated the pore morphology tuning of asymmetric block copolymer membrane by complexing with small organic molecules. We found that the occurrence of hydrogen-bond formation between PS-b-P4VP block copolymer and –OH/ –COOH functionalized organic molecules significantly tunes the pore morphology of asymmetric nanoporous membranes. In addition, we studied the complexation behavior of ionic liquids with PS-b-P4VP block copolymer in solutions and investigated their effect on final membrane morphology during the non-solvent induced phase separation process. We found that non-protic ionic liquids facilitate the formation of hexagonal nanoporous block copolymer structure, while protic ionic liquids led to a lamella-structured membrane. Secondly, we demonstrated the catalytic activity of the gold nanoparticle-enhanced hollow fiber membranes by the reduction of nitrophenol. Also, we systematically investigated the pore morphology of isoporous PS-b-P4VP using 3D imaging technique. Thirdly, we developed well-distributed silver nanoparticles on the

  9. Abdominal wall blocks in adults

    DEFF Research Database (Denmark)

    Børglum, Jens; Gögenür, Ismail; Bendtsen, Thomas F

    2016-01-01

    been introduced with success. Future research should also investigate the effect of specific abdominal wall blocks on neuroendocrine and inflammatory stress response after surgery.  Summary USG abdominal wall blocks in adults are commonplace techniques today. Most abdominal wall blocks are assigned......Purpose of review Abdominal wall blocks in adults have evolved much during the last decade; that is, particularly with the introduction of ultrasound-guided (USG) blocks. This review highlights recent advances of block techniques within this field and proposes directions for future research.......  Recent findings Ultrasound guidance is now considered the golden standard for abdominal wall blocks in adults, even though some landmark-based blocks are still being investigated. The efficiency of USG transversus abdominis plane blocks in relation to many surgical procedures involving the abdominal wall...

  10. Change Around the Block?

    Science.gov (United States)

    Berlin, Joey

    2017-04-01

    Proponents of a block grant or per-capita cap trumpet them as vehicles for the federal government to give the states a capped amount of funding for Medicaid that legislatures would effectively distribute how they see fit. Questions abound as to what capped Medicaid funding would look like, and what effect it would have on the current Medicaid-eligible population, covered services, and physician payments.

  11. SUPERFICIAL CERVICAL PLEXUS BLOCK

    Directory of Open Access Journals (Sweden)

    Komang Mega Puspadisari

    2014-01-01

    Full Text Available Superficial cervical plexus block is one of the regional anesthesia in  neck were limited to thesuperficial fascia. Anesthesia is used to relieve pain caused either during or after the surgery iscompleted. This technique can be done by landmark or with ultrasound guiding. The midpointof posterior border of the Sternocleidomastoid was identified and the prosedure done on thatplace or on the level of cartilage cricoid.

  12. Biological effects of blocking blue and other visible light on the mouse retina.

    Science.gov (United States)

    Narimatsu, Toshio; Ozawa, Yoko; Miyake, Seiji; Kubota, Shunsuke; Yuki, Kenya; Nagai, Norihiro; Tsubota, Kazuo

    2014-08-01

    To elucidate the biological effects of blocking fluorescent light on the retina using specific blocking materials. Seven- to 8-week-old BALB/c mice were divided into three groups and placed in one of the three boxes: one blocked ultraviolet and violet wavelengths of light (violet blockade), one blocked ultraviolet, violet, blue and some other visible wavelengths (blue-plus blockade), and one allowed most visible light to pass through (control). They were then exposed to a white fluorescent lamp for 1 h at 5.65E-05 mW/cm(2) /s. After treatment, the electroretinogram, retinal outer nuclear layer thickness and retinal outer segment length were measured. In addition, retinal apoptotic cells were quantified by TdT-mediated dUTP nick-end labelling assay and c-Fos messenger RNA, and protein levels were measured by real-time reverse-transcription polymerase chain reaction and immunoblot analyses, respectively. The blue-plus blockade group retained a significantly better electroretinogram response following light exposure than the control or violet blockade groups. The blue-plus blockade group also exhibited greater outer nuclear layer thickness and greater outer-segment length, and fewer apoptotic cells after light exposure than the other groups. The c-Fos messenger RNA and protein levels were substantially reduced in the blue-plus blockade group and reduced to a lesser extent in the violet blockade group. The blockade of blue plus additional visible wavelengths of light was most effective in protecting the retina from light-induced damage. The blockade of violet light alone was also effective in reducing intracellular molecular responses, but these effects were not sufficient for attenuating retinal degeneration. © 2013 Royal Australian and New Zealand College of Ophthalmologists.

  13. E-Block: A Tangible Programming Tool with Graphical Blocks

    Directory of Open Access Journals (Sweden)

    Danli Wang

    2013-01-01

    Full Text Available This paper designs a tangible programming tool, E-Block, for children aged 5 to 9 to experience the preliminary understanding of programming by building blocks. With embedded artificial intelligence, the tool defines the programming blocks with the sensors as the input and enables children to write programs to complete the tasks in the computer. The symbol on the programming block's surface is used to help children understanding the function of each block. The sequence information is transferred to computer by microcomputers and then translated into semantic information. The system applies wireless and infrared technologies and provides user with feedbacks on both screen and programming blocks. Preliminary user studies using observation and user interview methods are shown for E-Block's prototype. The test results prove that E-Block is attractive to children and easy to learn and use. The project also highlights potential advantages of using single chip microcomputer (SCM technology to develop tangible programming tools for children.

  14. Temperature and anion responsive self-assembly of ionic liquid block copolymers coating gold nanoparticles

    Science.gov (United States)

    Li, Junbo; Zhao, Jianlong; Wu, Wenlan; Liang, Ju; Guo, Jinwu; Zhou, Huiyun; Liang, Lijuan

    2016-06-01

    In this paper, double hydrophilic ionic liquid block copolymers (ILBCs), poly poly[1-methyl-3-(2-methacryloyloxy propylimidazolium bromine)]- block-(N-isopropylacrylamide) (PMMPImB- b-PNIPAAm) was first synthesized by reversible additionfragmentation chain transfer (RAFT) and then attached on the surface of gold nanoparticles (Au NPs) via a strong gold-sulfur bonding for preparing hybrid nanoparticles (PMMPImB- b-PNIPAAm-@-Au NPs). The hybrid NPs had a three layers micelle-like structure, including a gold core, thermo-responsive inner shell and anion responsive outer corona. The self-assembling behavior of thermal- and anion-response from shell and corona were respectively investigated by change of temperature and addition of (CF3SO2)2N-. The results showed the hybrid NPs retained a stable dispersion beyond the lower critical solution temperature (LCST) because of the space or electrostatic protecting by outer PMMPImB. However, with increasing concentration of (CF3SO2)2N-, the micellization of self-assembling PMMPImB- b-PNIPAAm-@-Au NPs was induced to form micellar structure containing the core with hydrophobic PMMPImB-(CF3SO2)2N- surrounded by composite shell of Au NPs-PNIPAAm via the anionresponsive properties of ILBCs. These results indicated that the block copolymers protected plasmonic nanoparticles remain self-assembling properties of block copolymers when phase transition from outer corona polymer.

  15. Block and sub-block boundary strengthening in lath martensite

    NARCIS (Netherlands)

    Du, C.; Hoefnagels, J.P.M.; Vaes, R.; Geers, M.G.D.

    2016-01-01

    Well-defined uniaxial micro-tensile tests were performed on lath martensite single block specimens and multi-block specimens with different number of block boundaries parallel to the loading direction. Detailed slip trace analyses consistently revealed that in the {110}<111> slip system with the

  16. Does Transcranial Direct Current Stimulation Combined with Peripheral Electrical Stimulation Have an Additive Effect in the Control of Hip Joint Osteonecrosis Pain Associated with Sickle Cell Disease? A Protocol for a One-Session Double Blind, Block-Randomized Clinical Trial.

    Science.gov (United States)

    Lopes, Tiago da Silva; Silva, Wellington Dos Santos; Ribeiro, Sânzia B; Figueiredo, Camila A; Campbell, Fernanda Q; Daltro, Gildasio de Cerqueira; Valenzuela, Antônio; Montoya, Pedro; Lucena, Rita de C S; Baptista, Abrahão F

    2017-01-01

    Chronic pain in Sickle Cell Disease (SCD) is probably related to maladaptive plasticity of brain areas involved in nociceptive processing. Transcranial Direct Current Stimulation (tDCS) and Peripheral Electrical Stimulation (PES) can modulate cortical excitability and help to control chronic pain. Studies have shown that combined use of tDCS and PES has additive effects. However, to date, no study investigated additive effects of these neuromodulatory techniques on chronic pain in patients with SCD. This protocol describes a study aiming to assess whether combined use of tDCS and PES more effectively alleviate pain in patients with SCD compared to single use of each technique. The study consists of a one-session double blind, block-randomized clinical trial (NCT02813629) in which 128 participants with SCD and femoral osteonecrosis will be enrolled. Stepwise procedures will occur on two independent days. On day 1, participants will be screened for eligibility criteria. On day 2, data collection will occur in four stages: sample characterization, baseline assessment, intervention, and post-intervention assessment. These procedures will last ~5 h. Participants will be divided into two groups according to homozygous for S allele (HbSS) ( n = 64) and heterozygous for S and C alleles (HbSC) ( n = 64) genotypes. Participants in each group will be randomly assigned, equally, to one of the following interventions: (1) active tDCS + active PES; (2) active tDCS + sham PES; (3) sham tDCS + active PES; and (4) sham tDCS + sham PES. Active tDCS intervention will consist of 20 min 2 mA anodic stimulation over the primary motor cortex contralateral to the most painful hip. Active PES intervention will consist of 30 min sensory electrical stimulation at 100 Hz over the most painful hip. The main study outcome will be pain intensity, measured by a Visual Analogue Scale. In addition, electroencephalographic power density, cortical maps of the gluteus maximus muscle elicited by

  17. Habitat Blocks and Wildlife Corridors

    Data.gov (United States)

    Vermont Center for Geographic Information — Habitat blocks are areas of contiguous forest and other natural habitats that are unfragmented by roads, development, or agriculture. Vermonts habitat blocks are...

  18. Atrioventricular block, ECG tracing (image)

    Science.gov (United States)

    ... an abnormal rhythm (arrhythmia) called an atrioventricular (AV) block. P waves show that the top of the ... wave (and heart contraction), there is an atrioventricular block, and a very slow pulse (bradycardia).

  19. Space Launch Systems Block 1B Preliminary Navigation System Design

    Science.gov (United States)

    Oliver, T. Emerson; Park, Thomas; Anzalone, Evan; Smith, Austin; Strickland, Dennis; Patrick, Sean

    2018-01-01

    NASA is currently building the Space Launch Systems (SLS) Block 1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. In parallel, NASA is also designing the Block 1B launch vehicle. The Block 1B vehicle is an evolution of the Block 1 vehicle and extends the capability of the NASA launch vehicle. This evolution replaces the Interim Cryogenic Propulsive Stage (ICPS) with the Exploration Upper Stage (EUS). As the vehicle evolves to provide greater lift capability, increased robustness for manned missions, and the capability to execute more demanding missions so must the SLS Integrated Navigation System evolved to support those missions. This paper describes the preliminary navigation systems design for the SLS Block 1B vehicle. The evolution of the navigation hard-ware and algorithms from an inertial-only navigation system for Block 1 ascent flight to a tightly coupled GPS-aided inertial navigation system for Block 1B is described. The Block 1 GN&C system has been designed to meet a LEO insertion target with a specified accuracy. The Block 1B vehicle navigation system is de-signed to support the Block 1 LEO target accuracy as well as trans-lunar or trans-planetary injection accuracy. Additionally, the Block 1B vehicle is designed to support human exploration and thus is designed to minimize the probability of Loss of Crew (LOC) through high-quality inertial instruments and robust algorithm design, including Fault Detection, Isolation, and Recovery (FDIR) logic.

  20. Fermion-scalar conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Iliesiu, Luca [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States); Kos, Filip [Department of Physics, Yale University,217 Prospect Street, New Haven, CT 06520 (United States); Poland, David [Department of Physics, Yale University,217 Prospect Street, New Haven, CT 06520 (United States); School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, New Jersey 08540 (United States); Pufu, Silviu S. [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States); Simmons-Duffin, David [School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, New Jersey 08540 (United States); Yacoby, Ran [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States)

    2016-04-13

    We compute the conformal blocks associated with scalar-scalar-fermion-fermion 4-point functions in 3D CFTs. Together with the known scalar conformal blocks, our result completes the task of determining the so-called ‘seed blocks’ in three dimensions. Conformal blocks associated with 4-point functions of operators with arbitrary spins can now be determined from these seed blocks by using known differential operators.

  1. Powder wastes confinement block and manufacturing process of this block

    International Nuclear Information System (INIS)

    Dagot, L.; Brunel, G.

    1996-01-01

    This invention concerns a powder wastes containment block and a manufacturing process of this block. In this block, the waste powder is encapsulated in a thermo hardening polymer as for example an epoxy resin, the encapsulated resin being spread into cement. This block can contain between 45 and 55% in mass of wastes, between 18 and 36% in mass of polymer and between 14 and 32% in mass of cement. Such a containment block can be used for the radioactive wastes storage. (O.M.). 4 refs

  2. Nanostructured Polysulfone-Based Block Copolymer Membranes

    KAUST Repository

    Xie, Yihui

    2016-05-01

    The aim of this work is to fabricate nanostructured membranes from polysulfone-based block copolymers through self-assembly and non-solvent induced phase separation. Block copolymers containing polysulfone are novel materials for this purpose providing better mechanical and thermal stability to membranes than polystyrene-based copolymers, which have been exclusively used now. Firstly, we synthesized a triblock copolymer, poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) through polycondensation and reversible addition-fragmentation chain-transfer polymerization. The obtained membrane has a highly porous interconnected skin layer composed of elongated micelles with a flower-like arrangement, on top of the graded finger-like macrovoids. Membrane surface hydrolysis was carried out in a combination with metal complexation to obtain metal-chelated membranes. The copper-containing membrane showed improved antibacterial capability. Secondly, a poly(acrylic acid)-b-polysulfone-b-poly(acrylic acid) triblock copolymer obtained by hydrolyzing poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) formed a thin film with cylindrical poly(acrylic acid) microdomains in polysulfone matrix through thermal annealing. A phase inversion membrane was prepared from the same polymer via self-assembly and chelation-assisted non-solvent induced phase separation. The spherical micelles pre-formed in a selective solvent mixture packed into an ordered lattice in aid of metal-poly(acrylic acid) complexation. The space between micelles was filled with poly(acrylic acid)-metal complexes acting as potential water channels. The silver0 nanoparticle-decorated membrane was obtained by surface reduction, having three distinct layers with different particle sizes. Other amphiphilic copolymers containing polysulfone and water-soluble segments such as poly(ethylene glycol) and poly(N-isopropylacrylamide) were also synthesized through coupling reaction and copper0-mediated

  3. Infinite-degree-corrected stochastic block model

    DEFF Research Database (Denmark)

    Herlau, Tue; Schmidt, Mikkel Nørgaard; Mørup, Morten

    2014-01-01

    In stochastic block models, which are among the most prominent statistical models for cluster analysis of complex networks, clusters are defined as groups of nodes with statistically similar link probabilities within and between groups. A recent extension by Karrer and Newman [Karrer and Newman...... corrected stochastic block model as a nonparametric Bayesian model, incorporating a parameter to control the amount of degree correction that can then be inferred from data. Additionally, our formulation yields principled ways of inferring the number of groups as well as predicting missing links...

  4. Building Curriculum during Block Play

    Science.gov (United States)

    Andrews, Nicole

    2015-01-01

    Blocks are not just for play! In this article, Nicole Andrews describes observing the interactions of three young boys enthusiastically engaged in the kindergarten block center of their classroom, using blocks in a building project that displayed their ability to use critical thinking skills, physics exploration, and the development of language…

  5. Blocking the Hawking radiation

    DEFF Research Database (Denmark)

    Autzen, M.; Kouvaris, C.

    2014-01-01

    grows after its formation (and eventually destroys the star) instead of evaporating. The fate of the black hole is dictated by the two opposite mechanics, i.e., accretion of nuclear matter from the center of the star and Hawking radiation that tends to decrease the mass of the black hole. We study how...... the assumptions for the accretion rate can in fact affect the critical mass beyond which a black hole always grows. We also study to what extent degenerate nuclear matter can impede Hawking radiation due to the fact that emitted particles can be Pauli blocked at the core of the star....

  6. Evaluation of Advanced Polymers for Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Orlando [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carter, William G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kutchko, Cindy [PPG Industries, Pittsburgh, PA (United States); Fenn, David [PPG Industries, Pittsburgh, PA (United States); Olson, Kurt [PPG Industries, Pittsburgh, PA (United States)

    2017-09-08

    The goal of this Manufacturing Demonstration Facility (MDF) technical collaboration project between Oak Ridge National Laboratory (ORNL) and PPG Industries, Inc. (PPG) was to evaluate the feasibility of using conventional coatings chemistry and technology to build up material layer-by-layer. The PPG-ORNL study successfully demonstrated that polymeric coatings formulations may overcome many limitations of common thermoplastics used in additive manufacturing (AM), allow lightweight nozzle design for material deposition, and increase build rate. The materials effort focused on layer-by-layer deposition of coatings with each layer fusing together. The combination of materials and deposition results in an additively manufactured build that has sufficient mechanical properties to bear the load of additional layers, yet is capable of bonding across the z-layers to improve build direction strength. The formulation properties were tuned to enable a novel, high-throughput deposition method that is highly scalable, compatible with high loading of reinforcing fillers, and inherently low-cost.

  7. A standard graphite block

    Energy Technology Data Exchange (ETDEWEB)

    Ivkovic, M; Zdravkovic, Z; Sotic, O [Department of Reactor Physics and Dynamics, Boris Kidric Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)

    1966-04-15

    A graphite block was calibrated for the thermal neutron flux of the Ra-Be source using indium foils as detectors. Experimental values of the thermal neutron flux along the central vertical axis of the system were corrected for the self-shielding effect and depression of flux in the detector. The experimental values obtained were compared with the values calculated on the basis of solving the conservation neutron equation by the continuous slowing-down theory. In this theoretical calculation of the flux the Ra-Be source was divided into three resonance energy regions. The measurement of the thermal neutron diffusion length in the standard graphite block is described. The measurements were performed in the thermal neutron region of the system. The experimental results were interpreted by the diffusion theory for point thermal neutron source in the finite system. The thermal neutron diffusion length was calculated to be L= 50.9 {+-}3.1 cm for the following graphite characteristics: density = 1.7 g/cm{sup 3}; boron content = 0.1 ppm; absorption cross section = 3.7 mb.

  8. A standard graphite block

    International Nuclear Information System (INIS)

    Ivkovic, M.; Zdravkovic, Z.; Sotic, O.

    1966-04-01

    A graphite block was calibrated for the thermal neutron flux of the Ra-Be source using indium foils as detectors. Experimental values of the thermal neutron flux along the central vertical axis of the system were corrected for the self-shielding effect and depression of flux in the detector. The experimental values obtained were compared with the values calculated on the basis of solving the conservation neutron equation by the continuous slowing-down theory. In this theoretical calculation of the flux the Ra-Be source was divided into three resonance energy regions. The measurement of the thermal neutron diffusion length in the standard graphite block is described. The measurements were performed in the thermal neutron region of the system. The experimental results were interpreted by the diffusion theory for point thermal neutron source in the finite system. The thermal neutron diffusion length was calculated to be L= 50.9 ±3.1 cm for the following graphite characteristics: density = 1.7 g/cm 3 ; boron content = 0.1 ppm; absorption cross section = 3.7 mb

  9. A tandem queue with server slow-down and blocking

    NARCIS (Netherlands)

    van Foreest, N.D.; van Ommeren, Jan C.W.; Mandjes, M.R.H.; Scheinhardt, Willem R.W.

    2005-01-01

    We consider two variants of a two-station tandem network with blocking. In both variants the first server ceases to work when the queue length at the second station hits a 'blocking threshold.' In addition, in variant 2 the first server decreases its service rate when the second queue exceeds a

  10. A tandem queue with server slow-down and blocking.

    NARCIS (Netherlands)

    van Foreest, N.; van Ommeren, J.C.; Mandjes, M.R.H.; Scheinhardt, W.

    2005-01-01

    We consider two variants of a two-station tandem network with blocking. In both variants the first server ceases to work when the queue length at the second station hits a 'blocking threshold.' In addition, in variant 2 the first server decreases its service rate when the second queue exceeds a

  11. Divergent synthesis and optoelectronic properties of oligodiacetylene building blocks

    NARCIS (Netherlands)

    Pilzak, G.S.; Lagen, van B.; Sudhölter, E.J.R.; Zuilhof, H.

    2008-01-01

    A new and divergent synthetic route to oligodiacetylene (ODA) building blocks has been developed via Sonogashira reactions under a reductive atmosphere. These central building blocks provide a new way for rapid preparation of long ODAs. In addition, we report on their optoelectronic properties which

  12. 21 CFR 177.1810 - Styrene block polymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene block polymers. 177.1810 Section 177.1810... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The styrene...

  13. CEMENT KILN DUST AS A MATERIAL FOR BUILDING BLOCKS ...

    African Journals Online (AJOL)

    This paper presents the results of a study on the properties of hollow sandcrete blocks with cement kiln dust (CKD) as an additive and as a replacement for ordinary portland cement (OPC). When CKD was used as a replacement for cement, the compressive strength and density of blocks generally decreased with higher ...

  14. The wild tapered block bootstrap

    DEFF Research Database (Denmark)

    Hounyo, Ulrich

    In this paper, a new resampling procedure, called the wild tapered block bootstrap, is introduced as a means of calculating standard errors of estimators and constructing confidence regions for parameters based on dependent heterogeneous data. The method consists in tapering each overlapping block...... of the series first, the applying the standard wild bootstrap for independent and heteroscedastic distrbuted observations to overlapping tapered blocks in an appropriate way. Its perserves the favorable bias and mean squared error properties of the tapered block bootstrap, which is the state-of-the-art block......-order asymptotic validity of the tapered block bootstrap as well as the wild tapered block bootstrap approximation to the actual distribution of the sample mean is also established when data are assumed to satisfy a near epoch dependent condition. The consistency of the bootstrap variance estimator for the sample...

  15. Photovoltaic building blocks

    DEFF Research Database (Denmark)

    Hanberg, Peter Jesper; Jørgensen, Anders Michael

    2014-01-01

    efficiency of about 15% for commercial Silicon solar cells there is still much to gain. DTU Danchip provides research facilities, equipment and expertise for the building blocks that comprises fabricating the efficient solar cell. In order to get more of the sun light into the device we provide thin film......Photovoltaics (PV), better known as solar cells, are now a common day sight on many rooftops in Denmark.The installed capacity of PV systems worldwide is growing exponentially1 and is the third most importantrenewable energy source today. The cost of PV is decreasing fast with ~10%/year but to make...... it directcompetitive with fossil energy sources a further reduction is needed. By increasing the efficiency of the solar cells one gain an advantage through the whole chain of cost. So that per produced Watt of power less material is spent, installation costs are lower, less area is used etc. With an average...

  16. Celiac ganglia block

    International Nuclear Information System (INIS)

    Akinci, Devrim; Akhan, Okan

    2005-01-01

    Pain occurs frequently in patients with advanced cancers. Tumors originating from upper abdominal viscera such as pancreas, stomach, duodenum, proximal small bowel, liver and biliary tract and from compressing enlarged lymph nodes can cause severe abdominal pain, which do not respond satisfactorily to medical treatment or radiotherapy. Percutaneous celiac ganglia block (CGB) can be performed with high success and low complication rates under imaging guidance to obtain pain relief in patients with upper abdominal malignancies. A significant relationship between pain relief and degree of tumoral celiac ganglia invasion according to CT features was described in the literature. Performing the procedure in the early grades of celiac ganglia invasion on CT can increase the effectiveness of the CGB, which is contrary to World Health Organization criteria stating that CGB must be performed in patients with advanced stage cancer. CGB may also be effectively performed in patients with chronic pancreatitis for pain palliation

  17. Atomic Basic Blocks

    Science.gov (United States)

    Scheler, Fabian; Mitzlaff, Martin; Schröder-Preikschat, Wolfgang

    Die Entscheidung, einen zeit- bzw. ereignisgesteuerten Ansatz für ein Echtzeitsystem zu verwenden, ist schwierig und sehr weitreichend. Weitreichend vor allem deshalb, weil diese beiden Ansätze mit äußerst unterschiedlichen Kontrollflussabstraktionen verknüpft sind, die eine spätere Migration zum anderen Paradigma sehr schwer oder gar unmöglich machen. Wir schlagen daher die Verwendung einer Zwischendarstellung vor, die unabhängig von der jeweils verwendeten Kontrollflussabstraktion ist. Für diesen Zweck verwenden wir auf Basisblöcken basierende Atomic Basic Blocks (ABB) und bauen darauf ein Werkzeug, den Real-Time Systems Compiler (RTSC) auf, der die Migration zwischen zeit- und ereignisgesteuerten Systemen unterstützt.

  18. EDITORIAL: Nature's building blocks Nature's building blocks

    Science.gov (United States)

    Engel, Andreas

    2009-10-01

    The scanning tunnelling microscope (STM), invented by Gerd Binnig and Heinrich Rohrer in the early 1980s in the IBM Laboratory in Zurich, and the atomic force microscope (AFM) that followed shortly afterwards, were key developments that initiated a new era in scientific research: nanotechnology. These and related scanning probe microscopes have become fruitful tools in the study of cells, supramolecular assemblies and single biomolecules, as well as other nanoscale structures. In particular, the ability to investigate living matter in native environments made possible by atomic force microscopy, has allowed pronounced progress in biological research. The journal Nanotechnology was the first to serve as a publication platform for this rapidly developing field of science. The journal celebrates its 20th volume with this special issue, which presents a collection of original research articles in various fields of science, but all with the common feature that the structures, processes and functions all take place at the nanometre scale. Scanning probe microscopes are constantly being devised with increasingly sophisticated sensing and actuating features that optimize their performance. However, while these tools continue to provide impressive and informative images of nanoscale systems and allow single molecules to be manipulated with increasing dexterity, a wider field of research activity stimulated either by or for biology has emerged. The unique properties of matter at the nanoscale, such as localized surface plasmons supported by nanostructures, have been exploited in sensors with unprecedented sensitivity. Nanostructures have also found a profitable role in the encapsulation of molecules for 'smart' drug delivery. The potential application of DNA in the self-assembly of nanostructures guided by molecular recognition is another rapidly advancing area of research. In this issue a group of researchers in Germany report how the addition of copper ions can promote the

  19. Cement Stabilized Soil Blocks Admixed with Sugarcane Bagasse Ash

    Directory of Open Access Journals (Sweden)

    Jijo James

    2016-01-01

    Full Text Available The study involved investigating the performance of ordinary Portland cement (OPC stabilized soil blocks amended with sugarcane bagasse ash (SBA. Locally available soil was tested for its properties and characterized as clay of medium plasticity. This soil was stabilized using 4% and 10% OPC for manufacture of blocks of size 19 cm × 9 cm × 9 cm. The blocks were admixed with 4%, 6%, and 8% SBA by weight of dry soil during casting, with plain OPC stabilized blocks acting as control. All blocks were cast to one target density and water content followed by moist curing for a period of 28 days. They were then subjected to compressive strength, water absorption, and efflorescence tests in accordance with Bureau of Indian standards (BIS specifications. The results of the tests indicated that OPC stabilization resulted in blocks that met the specifications of BIS. Addition of SBA increased the compressive strength of the blocks and slightly increased the water absorption but still met the standard requirement of BIS code. It is concluded that addition of SBA to OPC in stabilized block manufacture was capable of producing stabilized blocks at reduced OPC content that met the minimum required standards.

  20. Some Blocks from Heliopolis

    Directory of Open Access Journals (Sweden)

    dr.Nageh Omar

    2005-01-01

    Full Text Available These group of Architectural Fragments have been discovered during Excavations at Souq el – Khamees Site at the end of Mostorod Street in el – Matarya Area by the Supreme Council of Antiquities Mission Season 2003 and none published before . The Site of Excavations is Situated about 500 metres to the west Obelisk of the King Senusert I According to the inscriptions on the block (pl.1.a,fig.1 represents the coronation name of the king Senusret III, the fifth king of the twelfth dynasty within the cartouche .Through This recent discover and his Sphinx statue we Suggest that the king Senusret III built a shrine or Temple at Heliopols which was possibly a part of the great Temple of the universal God of Heliopolis . For block dating to the king Akhenaten and many monuments are discovered in Heliopolis at the same period emphasized that the king Akhenaten built temple for the god Aten in Heliopolis and through Studies about the king Akhenaten, we suggest that the king Akhenaten take his new principles from Heliopolis . The king Ramesses II mentioned from stela which discovered at Manshyt el- Sader, in the second horizontal line that he erected oblesk and some statues at the great Temple in Heliopolis , this recent Discover about Statue of the king Ramesses II emphasized site of excavations perhaps a shrine or open court from temple of the king Ramesses II at the great Temple in Heliopolis For nbt – htpt, we could show that the goddess Hathor take a forward position in Heliopolis and become the Lady of Hetepet in Heliopolis since Eighteenth dynasty at least

  1. Strength of masonry blocks made with recycled concrete aggregates

    Science.gov (United States)

    Matar, Pierre; Dalati, Rouba El

    The idea of recycling concrete of demolished buildings aims at preserving the environment. Indeed, the reuse of concrete as aggregate in new concrete mixes helped to reduce the expenses related to construction and demolition (C&D) waste management and, especially, to protect the environment by reducing the development rate of new quarries. This paper presents the results of an experimental study conducted on masonry blocks containing aggregates resulting from concrete recycling. The purpose of this study is to investigate the effect of recycled aggregates on compressive strength of concrete blocks. Tests were performed on series of concrete blocks: five series each made of different proportions of recycled aggregates, and one series of reference blocks exclusively composed of natural aggregates. Tests showed that using recycled aggregates with addition of cement allows the production of concrete blocks with compressive strengths comparable to those obtained on concrete blocks made exclusively of natural aggregates.

  2. Support agnostic Bayesian matching pursuit for block sparse signals

    KAUST Repository

    Masood, Mudassir

    2013-05-01

    A fast matching pursuit method using a Bayesian approach is introduced for block-sparse signal recovery. This method performs Bayesian estimates of block-sparse signals even when the distribution of active blocks is non-Gaussian or unknown. It is agnostic to the distribution of active blocks in the signal and utilizes a priori statistics of additive noise and the sparsity rate of the signal, which are shown to be easily estimated from data and no user intervention is required. The method requires a priori knowledge of block partition and utilizes a greedy approach and order-recursive updates of its metrics to find the most dominant sparse supports to determine the approximate minimum mean square error (MMSE) estimate of the block-sparse signal. Simulation results demonstrate the power and robustness of our proposed estimator. © 2013 IEEE.

  3. Polymeric microcapsules assembled from a cationic/zwitterionic pair of responsive block copolymer micelles.

    Science.gov (United States)

    Addison, Timothy; Cayre, Olivier J; Biggs, Simon; Armes, Steven P; York, David

    2010-05-04

    Using a layer-by-layer (LbL) approach, this work presents the preparation of hollow microcapsules with a membrane constructed entirely from a cationic/zwitterionic pair of pH-responsive block copolymer micelles. Our previous work with such systems highlighted that, in order to retain the responsive nature of the individual micelles contained within the multilayer membranes, it is important to optimize the conditions required for the selective dissolution of the sacrificial particulate templates. Consequently, here, calcium carbonate particles have been employed as colloidal templates as they can be easily dissolved in aqueous environments with the addition of chelating agents such as ethylenediaminetetraacetic acid (EDTA). Furthermore, the dissolution can be carried out in solutions buffered to a desirable pH so not to adversely affect the pH sensitive micelles forming the capsule membranes. First, we have deposited alternating layers of anionic poly[2-(dimethylamino)ethyl methacrylate-block-poly(2-(diethylamino)ethyl methacrylate)] (PDMA-PDEA) and cationic poly(2-(diethylamino)ethyl)methacrylate-block-poly(methacrylic acid) (PDEA-PMAA) copolymer micelles onto calcium carbonate colloidal templates. After deposition of five micelle bilayers, addition of dilute EDTA solution resulted in dissolution of the calcium carbonate and formation of hollow polymer capsules. The capsules were imaged using atomic force microscopy (AFM) and scanning electron microscopy (SEM), which shows that the micelle/micelle membrane is sufficiently robust to withstand dissolution of the supporting template. Quartz crystal microbalance studies were conducted and provide good evidence that the micelle multilayer structure is retained after EDTA treatment. In addition, a hydrophobic dye was incorporated into the micelle cores prior to adsorption. After dissolution of the particle template, the resulting hollow capsules retained a high concentration of dye, suggesting that the core

  4. Effects of different building blocks designs on the statistical ...

    African Journals Online (AJOL)

    Tholang T. Mokhele

    Enumeration Areas (EAs), Small Area Layers (SALs) and SubPlaces) from the 2001 census data were used as building blocks for the generation of census output areas with AZTool program in both rural and urban areas of South Africa. One way-Analysis of Variance (ANOVA) was also performed to determine statistical ...

  5. Determination of thermal conductivities of some topsoils using block ...

    African Journals Online (AJOL)

    This study focuses on the determination of In situ measurement of the top soil layer, despite non-homogeneity of natural soils caused by changes in their water content, texture and structure. Thermal Conductivities of clay, loam and sand soils were determined using improved Block method with and without the use of ...

  6. THE LYCHEE TREE PROPAGATION BY LAYERING

    Directory of Open Access Journals (Sweden)

    LEILA CRISTINA ROSA LINS

    2015-06-01

    Full Text Available The aim of the study was to assess the influence of season and different substrates on rooting of air layers of lychee (Litchi chinensisSonn. for the production of seedlings to ensure the formation of uniform and productive orchards. Air layers were done in plants of the Bengal cultivar using leafy and healthy woody branches, with about 0.010 to 0.015 m in diameter, in which were performed complete girdling with 0.020 m wide at a distance of 0.30 to 0.40 m below the apex. Then the branches were wrapped in moistened substrate. The layering was made at six times of theyear (January, March, May, July, September and November and two substrates were used (coconut fiber and sphagnum in a 6 x 2 factorial design in a randomized block with ten replicates. After 90 days, layers were separated from the matrix plant and evaluated for rooting and callus formation, root number, considering only the primary roots, length, area and volume of the roots, beyond the dry weight of roots and calluses. The months of January, March, September and November showed the best results for all analyzed variables related to rooting. With respect to the substrates, the only difference was in January and March to the root number and dry weight of roots, where the sphagnum showed the best results. The month of July was more conducive to the formation of calluses. The period between September and March was more suitable to the propagation of lychee, when there were rooting percentages above 90%, in addition to the formation of large amount of roots.

  7. Simplified Casing Program for Development Wells in Mahu Well Block

    Directory of Open Access Journals (Sweden)

    Lu Zongyu

    2017-01-01

    Full Text Available In the Mahu well block of Junggar basin, the complex formation has many sets of pressure system. Especially, the formation with microcracks in the middle layer is loose and the pressure bearing capacity is low. Lost circulation is prone to occur in this layer. At present, high investment and long drilling period were the main problems in the exploration and development process. The geostress 3D model of Mahu well block was established by means of logging and drilling data. The model provided the three-pressure profiles of Mahu well block for casing program optimization and safety drilling. Each well could be optimized the intermediate casing setting position. The intermediate casing was saved 160 meters long. The total of drilling speed was improved 5 times compared with the past drilling process. Slim hole drilling technology raised ROP 51.96% higher, and the average drilling period is shorten to 24.83 days.

  8. Structural origins of broadband emission from layered Pb–Br hybrid perovskites† †Electronic supplementary information (ESI) available. CCDC 1521053–1521055, 1521057–1521060 and 1521067. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc01590a Click here for additional data file. Click here for additional data file.

    Science.gov (United States)

    Smith, Matthew D.; Jaffe, Adam; Dohner, Emma R.; Lindenberg, Aaron M.

    2017-01-01

    Through structural and optical studies of a series of two-dimensional hybrid perovskites, we show that broadband emission upon near-ultraviolet excitation is common to (001) lead-bromide perovskites. Importantly, we find that the relative intensity of the broad emission correlates with increasing out-of-plane distortion of the Pb–(μ-Br)–Pb angle in the inorganic sheets. Temperature- and power-dependent photoluminescence data obtained on a representative (001) perovskite support an intrinsic origin to the broad emission from the bulk material, where photogenerated carriers cause excited-state lattice distortions mediated through electron–lattice coupling. In contrast, most inorganic phosphors contain extrinsic emissive dopants or emissive surface sites. The design rules established here could allow us to systematically optimize white-light emission from layered hybrid perovskites by fine-tuning the bulk crystal structure. PMID:28970879

  9. Powered Explicit Guidance Modifications and Enhancements for Space Launch System Block-1 and Block-1B Vehicles

    Science.gov (United States)

    Von der Porten, Paul; Ahmad, Naeem; Hawkins, Matt; Fill, Thomas

    2018-01-01

    NASA is currently building the Space Launch System (SLS) Block-1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. NASA is also currently designing the next evolution of SLS, the Block-1B. The Block-1 and Block-1B vehicles will use the Powered Explicit Guidance (PEG) algorithm (of Space Shuttle heritage) for closed loop guidance. To accommodate vehicle capabilities and design for future evolutions of SLS, modifications were made to PEG for Block-1 to handle multi-phase burns, provide PEG updated propulsion information, and react to a core stage engine out. In addition, due to the relatively low thrust-to-weight ratio of the Exploration Upper Stage (EUS) and EUS carrying out Lunar Vicinity and Earth Escape missions, certain enhancements to the Block-1 PEG algorithm are needed to perform Block-1B missions to account for long burn arcs and target translunar and hyperbolic orbits. This paper describes the design and implementation of modifications to the Block-1 PEG algorithm as compared to Space Shuttle. Furthermore, this paper illustrates challenges posed by the Block-1B vehicle and the required PEG enhancements. These improvements make PEG capable for use on the SLS Block-1B vehicle as part of the Guidance, Navigation, and Control (GN&C) System.

  10. Double-layered buffer to enhance the thermal performance in a high-level radioactive waste disposal system

    International Nuclear Information System (INIS)

    Choi, Heui-Joo; Choi, Jongwon

    2008-01-01

    A thermal performance is one of the most important factors in the design of a geological disposal system for high-level radioactive wastes. According to the conceptual design of the Korean Reference disposal System, the maximum temperature of its buffer with a domestic Ca-bentonite is close to the thermal criterion, 100 deg. C. In order to improve the thermal conductivity of its buffer, several kinds of additives are compared. Among the additives, graphite shows the best result in that the thermal conductivity of the bentonite block is more than 2.0 W/m deg. C. We introduced the concept of a double-layered buffer instead of a traditional bentonite block in order to use the applied additive more effectively. The thermal analysis, based upon the three-dimensional finite element method, shows that a double-layered buffer could reduce the maximum temperature on a canister's surface by 7 deg. C under identical conditions when compared with a single-layered buffer. An analytical solution was derived to efficiently analyze the effects of a double-layered buffer. The illustrative cases show that the temperature differences due to a double-layered buffer depend on the thickness of the buffer

  11. Layered materials

    Science.gov (United States)

    Johnson, David; Clarke, Simon; Wiley, John; Koumoto, Kunihito

    2014-06-01

    Layered compounds, materials with a large anisotropy to their bonding, electrical and/or magnetic properties, have been important in the development of solid state chemistry, physics and engineering applications. Layered materials were the initial test bed where chemists developed intercalation chemistry that evolved into the field of topochemical reactions where researchers are able to perform sequential steps to arrive at kinetically stable products that cannot be directly prepared by other approaches. Physicists have used layered compounds to discover and understand novel phenomena made more apparent through reduced dimensionality. The discovery of charge and spin density waves and more recently the remarkable discovery in condensed matter physics of the two-dimensional topological insulating state were discovered in two-dimensional materials. The understanding developed in two-dimensional materials enabled subsequent extension of these and other phenomena into three-dimensional materials. Layered compounds have also been used in many technologies as engineers and scientists used their unique properties to solve challenging technical problems (low temperature ion conduction for batteries, easy shear planes for lubrication in vacuum, edge decorated catalyst sites for catalytic removal of sulfur from oil, etc). The articles that are published in this issue provide an excellent overview of the spectrum of activities that are being pursued, as well as an introduction to some of the most established achievements in the field. Clusters of papers discussing thermoelectric properties, electronic structure and transport properties, growth of single two-dimensional layers, intercalation and more extensive topochemical reactions and the interleaving of two structures to form new materials highlight the breadth of current research in this area. These papers will hopefully serve as a useful guideline for the interested reader to different important aspects in this field and

  12. Multi-layer universal correction magnet

    International Nuclear Information System (INIS)

    Parzen, G.

    1981-08-01

    This paper presents an approach for constructing a universal correction magnet in which the return currents play an active role in determining the field. The return currents are not hidden by the iron shield. The coil is wound in many layers, instead of just one layer. Each layer has a particular symmetry, and generates a particular class of field multipoles such that the location of the return current for each independently excited current block is clear. Three layers may be sufficient in many cases. This approach is applied to the ISABELLE storage accelerator correction system

  13. Strength and deformability of hollow concrete blocks: correlation of block and cylindrical sample test results

    Directory of Open Access Journals (Sweden)

    C. S. Barbosa

    Full Text Available This paper deals with correlations among mechanical properties of hollow blocks and those of concrete used to make them. Concrete hollow blocks and test samples were moulded with plastic consistency concrete, to assure the same material in all cases, in three diferente levels of strength (nominally 10 N/mm², 20 N/mm² and 30 N/mm². The mechanical properties and structural behaviour in axial compression and tension tests were determined by standard tests in blocks and cylinders. Stress and strain analyses were made based on concrete’s modulus of elasticity obtained in the sample tests as well as on measured strain in the blocks’ face-shells and webs. A peculiar stress-strain analysis, based on the superposition of effects, provided an estimation of the block load capacity based on its deformations. In addition, a tentative method to preview the block deformability from the concrete mechanical properties is described and tested. This analysis is a part of a broader research that aims to support a detailed structural analysis of blocks, prisms and masonry constructions.

  14. Blocking-resistant communication through domain fronting

    Directory of Open Access Journals (Sweden)

    Fifield David

    2015-06-01

    Full Text Available We describe “domain fronting,” a versatile censorship circumvention technique that hides the remote endpoint of a communication. Domain fronting works at the application layer, using HTTPS, to communicate with a forbidden host while appearing to communicate with some other host, permitted by the censor. The key idea is the use of different domain names at different layers of communication. One domain appears on the “outside” of an HTTPS request—in the DNS request and TLS Server Name Indication—while another domain appears on the “inside”—in the HTTP Host header, invisible to the censor under HTTPS encryption. A censor, unable to distinguish fronted and nonfronted traffic to a domain, must choose between allowing circumvention traffic and blocking the domain entirely, which results in expensive collateral damage. Domain fronting is easy to deploy and use and does not require special cooperation by network intermediaries. We identify a number of hard-to-block web services, such as content delivery networks, that support domain-fronted connections and are useful for censorship circumvention. Domain fronting, in various forms, is now a circumvention workhorse. We describe several months of deployment experience in the Tor, Lantern, and Psiphon circumvention systems, whose domain-fronting transports now connect thousands of users daily and transfer many terabytes per month.

  15. Common blocks for ASQS(12

    Directory of Open Access Journals (Sweden)

    Lorenzo Milazzo

    1997-05-01

    Full Text Available An ASQS(v is a particular Steiner system featuring a set of v vertices and two separate families of blocks, B and G, whose elements have a respective cardinality of 4 and 6. It has the property that any three vertices of X belong either to a B-block or to a G-block. The parameter cb is the number of common blocks in two separate ASQSs, both defined on the same set of vertices X . In this paper it is shown that cb ≤ 29 for any pair of ASQSs(12.

  16. Adductor Canal Block versus Femoral Nerve Block and Quadriceps Strength

    DEFF Research Database (Denmark)

    Jæger, Pia Therese; Nielsen, Zbigniew Jerzy Koscielniak; Henningsen, Lene Marianne

    2013-01-01

    : The authors hypothesized that the adductor canal block (ACB), a predominant sensory blockade, reduces quadriceps strength compared with placebo (primary endpoint, area under the curve, 0.5-6 h), but less than the femoral nerve block (FNB; secondary endpoint). Other secondary endpoints were...

  17. Strong signatures of high-latitude blocks and subtropical ridges in winter PM10 over Europe

    Science.gov (United States)

    Ordonez, C.; Garrido-Perez, J. M.; Garcia-Herrera, R.

    2017-12-01

    Atmospheric blocking is associated with persistent, slow-moving high pressure systems that interrupt the eastward progress of extratropical storm systems at middle and high latitudes. Subtropical ridges are low latitude structures manifested as bands of positive geopotential height anomalies extending from sub-tropical latitudes towards extra-tropical regions. We have quantified the impact of blocks and ridges on daily PM10 (particulate matter ≤ 10 µm) observations obtained from the European Environment Agency's air quality database (AirBase) for the winter period of 2000-2010. For this purpose, the response of the PM10 concentrations to the location of blocks and ridges with centres in two main longitudinal sectors (Atlantic, ATL, 30˚-0˚ W; European, EUR, 0˚-30˚ E) is examined. EUR blocking is associated with a collapse of the boundary layer as well as reduced wind speeds and precipitation occurrence, yielding large positive anomalies which average 12 µg m-3 over the whole continent. Conversely, the enhanced zonal flow around 50˚-60˚ N and the increased occurrence of precipitation over northern-central Europe on days with ATL ridges favour the ventilation of the boundary layer and the impact of washout processes, reducing PM10 concentrations on average by around 8 µg m-3. The presence of EUR blocks is also concurrent with an increased probability of exceeding the European air quality target (50 µg m-3 for 24-h averaged PM10) and the local 90th percentiles for this pollutant at many sites, while the opposite effect is found for ridges. In addition, the effect of synoptic persistence on the PM10 concentrations is particularly strong for EUR blocks. Finally, we have found that the effect of both synoptic patterns can partly control the interannual variability of winter mean PM10 at many sites of north-western and central Europe, with coefficients of determination (R2) exceeding 0.80 for southern Germany. These results indicate that the response of the

  18. The block transfer system

    International Nuclear Information System (INIS)

    Bradish, G.J. III; Reid, A.E.

    1986-01-01

    The central instrumentation control and data acquisition (CICADA) computer system is comprised of a functionally distributed hierarchical network of thirteen (13) 32-bit mini-computers that are the heart of the control, monitoring, data collection and data analysis for the tokamak fusion test reactor (TFTR). The CICADA system was designed with the goal of providing complete control, monitoring, and data acquisition for TFTR, which includes the acquisition and storage of 20M points of data within a five-minute shot cycle. It was realized early in the system design that in order to meet this goal an ancillary system would have to be provided to supplement the subsystem CAMAC systems that, due to the relatively slow throughput of the serial highways and the overhead of relaying data to the central facilities within a star network, would not provide the necessary throughput. The authors discuss how the block transfer system provided a means of moving data directly from the CAMAC crate to the application running on the central facility computers

  19. An Implant-Passivated Blocked Impurity Band Germanium Detector for the Far Infrared, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to fabricate a germanium blocked-impurity-band (BIB) detector using a novel process which will enable us to: 1- fabricate a suitably-doped active layer...

  20. Thermoablation of Liver Metastases: Efficacy of Temporary Celiac Plexus Block

    International Nuclear Information System (INIS)

    Beck, A.N.; Schaefer, M.; Werk, M.; Pech, M.; Wieners, G.; Cho, C.; Ricke, J.

    2005-01-01

    Purpose. To determine the efficacy of celiac plexus block during thermoablation of liver metastases. Methods. Fifty-five consecutive patients underwent thermoablation therapy of liver tumors by laser-induced thermotherapy. Twenty-nine patients received a temporary celiac plexus block, 26 patients acted as control group. In both groups fentanyl and midazolam were administered intravenously upon request of the patient. The duration of the intervention, consumption of opiates, and individual pain sensations were documented. Results. No complications resulting from the celiac plexus block were recorded. Celiac plexus block significantly reduced the amount of pain medication used during thermoablation therapy of liver tumors (with block, 2.45 μg fentanyl per kg body weight; without block, 3.58 μg fentanyl per kg body weight, p < 0.05; midazolam consumption was not reduced) in patients with metastases ≤5 mm from the liver capsule. For metastases farther away from the capsule no significant differences in opiate consumption were seen. Celiac plexus block reduced the time for thermoablation significantly (178 min versus 147 min, p < 0.05) no matter how far the metastases were from the liver capsule. Average time needed to set the block was 12 min (range 9-15 min); additional costs for the block were marginal. As expected (as pain medications were given according to individual patients' needs) pain indices did not differ significantly between the two groups. Conclusion. In patients with liver metastases ≤5 mm from the liver capsule, celiac plexus block reduces the amount of opiates necessary, simplifying patient monitoring. In addition celiac plexus block reduces intervention time, with positive effects on overall workflow for all patients

  1. Preheating to around 100°C under endcap blocks before welding at KHI.

    CERN Multimedia

    Loveless, D

    2000-01-01

    The 600mm thick sector blocks of the CMS endcaps are made from three layers of 200mm plates welded together. During the manufacture at KHI, the blocks are preheated to around 100°C to prevent cracks in the welds.

  2. Role of dexamethasone in brachial plexus block

    International Nuclear Information System (INIS)

    Dawood, M.

    2015-01-01

    To evaluate the effect of dexamethasone added to (lignocaine) on the onset and duration of axillary brachial plexus block. Study Design: Randomized controlled trial. Place and Duration of Study: Combined Military Hospital Rawalpindi, from September 2009 to March 2010. Patients and Methods: A total of 100 patients, who were scheduled for elective hand and forearm surgery under axillary brachial plexus block, were randomly allocated to group A in which patients received 40 ml 1.5% lidocaine with 2 ml of isotonic saline (0.9%) and group B in which patients received 40 ml 1.5% lidocaine with 2 ml of dexamethasone (8 mg). Nerve stimulator with insulated needle for multiple stimulations technique was used to locate the brachial plexus nerves. After the injection onset of action and duration of sensory blockade of brachial plexus were recorded at 5 minutes and 15 minutes interval. Results: Group A showed the onset of action of 21.64 ± 2.30 min and in group B it was 15.42 ± 1.44 min (p< 0.001). Duration of nerve block was 115.08 ± 10.92 min in group A and 265.42 ± 16.56 min in group B (p < 0.001). Conclusion: The addition of dexamethasone to 1.5% lignocaine solution in axillary brachial plexus block prolongs the duration of sensory blockade significantly. (author)

  3. OPAL Various Lead Glass Blocks

    CERN Multimedia

    These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

  4. Writing Blocks and Tacit Knowledge.

    Science.gov (United States)

    Boice, Robert

    1993-01-01

    A review of the literature on writing block looks at two kinds: inability to write in a timely, fluent fashion, and reluctance by academicians to assist others in writing. Obstacles to fluent writing are outlined, four historical trends in treating blocks are discussed, and implications are examined. (MSE)

  5. Region 9 Census Block 2010

    Science.gov (United States)

    Geography:The TIGER Line Files are feature classes and related database files (.) that are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER Line File is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Census Blocks are statistical areas bounded on all sides by visible features, such as streets, roads, streams, and railroad tracks, and/or by non visible boundaries such as city, town, township, and county limits, and short line-of-sight extensions of streets and roads. Census blocks are relatively small in area; for example, a block in a city bounded by streets. However, census blocks in remote areas are often large and irregular and may even be many square miles in area. A common misunderstanding is that data users think census blocks are used geographically to build all other census geographic areas, rather all other census geographic areas are updated and then used as the primary constraints, along with roads and water features, to delineate the tabulation blocks. As a result, all 2010 Census blocks nest within every other 2010 Census geographic area, so that Census Bureau statistical data can be tabulated at the block level and aggregated up t

  6. Enhancement of device performance of organic solar cells by an interfacial perylene derivative layer

    KAUST Repository

    Kim, Inho; Haverinen, Hanna M.; Li, Jian; Jabbour, Ghassan E.

    2010-01-01

    We report that device performance of organic solar cells consisting of zinc phthalocyanine and fullerene (C60) can be enhanced by insertion of a perylene derivative interfacial layer between fullerene and bathocuproine (BCP) exciton blocking layer

  7. Temperature-triggered micellization of block copolymers on an ionic liquid surface.

    Science.gov (United States)

    Lu, Haiyun; Akgun, Bulent; Wei, Xinyu; Li, Le; Satija, Sushil K; Russell, Thomas P

    2011-10-18

    In situ neutron reflectivity was used to study thermally induced structural changes of the lamellae-forming polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) block copolymer thin films floating on the surface of an ionic liquid (IL). The IL, 1-butyl-3-methylimidazolium trifluoromethanesulfonate, is a nonsolvent for PS and a temperature-tunable solvent for P2VP, and, as such, micellization can be induced at the air-IL interface by changing the temperature. Transmission electron microscopy and scanning force microscopy were used to investigate the resultant morphologies of the micellar films. It was found that highly ordered nanostructures consisting of spherical micelles with a PS core surrounded by a P2VP corona were produced. In addition, bilayer films of PS homopolymer on top of a PS-b-P2VP layer also underwent micellization with increasing temperature but the micellization was strongly dependent on the thickness of the PS and PS-b-P2VP layers. © 2011 American Chemical Society

  8. Building blocks of the universe

    International Nuclear Information System (INIS)

    Malamud, E.; O'Connor, C.; Cooper, A.

    1990-01-01

    COSI [Ohio's Center for Science and Industry], a well established science center, and SciTech, an emerging one, have formed a collaboration to develop a group of original interactive exhibits conveying to a wide audience the nature of the most fundamental features of the Universe, as revealed in the fascinating world of nuclear and particle science. These new exhibits will add to, and be supported by, the basic science exhibits which have already attracted large numbers of visitors to both centers. The new project, called Building Blocks of the Universe, aims to foster an appreciation of the way all features of the Universe arise from simple, basic rules and to lead the visitor from the perceived complexities of our surroundings, to the unperceived, but simpler features of the sub-nuclear world. It has already become apparent from individual prototypes that these simple but immensely far-reaching ideas can indeed be conveyed by hands-on exhibits. These exhibits will be linked and enhanced by an effective museum environment, using pictorial diagrams, accurate non-technical text, and artistic displays to create an atmosphere in which visitors can learn about phenomena beyond the range of direct perception. This paper describes the goals, content and organization of the exhibition. The authors also outline their experience with prototype exhibits, and thereby invite additional input into the development process

  9. Organic-Inorganic Hybrid Interfacial Layer for High-Performance Planar Perovskite Solar Cells.

    Science.gov (United States)

    Yang, Hao; Cong, Shan; Lou, Yanhui; Han, Liang; Zhao, Jie; Sun, Yinghui; Zou, Guifu

    2017-09-20

    4,7-Diphenyl-1,10-phenanthroline (Bphen) is an efficient electron transport and hole blocking material in organic photoelectric devices. Here, we report cesium carbonate (Cs 2 CO 3 ) doped Bphen as cathode interfacial layer in CH 3 NH 3 PbI 3-x Cl x based planar perovskite solar cells (PSCs). Investigation finds that introducing Cs 2 CO 3 suppresses the crystallization of Bphen and benefits a smooth interface contact between the perovskite and electrode, resulting in the decrease in carrier recombination and the perovskite degradation. In addition, the matching energy level of Bphen film in the PSCs effectively blocks the holes diffusion to cathode. The resultant power conversion efficiency (PCE) achieves as high as 17.03% in comparison with 12.67% of reference device without doping. Besides, experiments also demonstrate the stability of PSCs have large improvement because the suppressed crystallization of Bphen by doping Cs 2 CO 3 as a superior barrier layer blocks the Ag atom and surrounding moisture access to the vulnerable perovskite layer.

  10. Analysis of natural stone block pavements in urban shared areas

    Directory of Open Access Journals (Sweden)

    Pablo Zoccali

    2018-06-01

    Full Text Available This paper analysed and verified an existing block stone pavement in an urban shared area. Fatigue and rutting verification was performed respectively for bound and unbound pavement materials using analytical curves available in the literature. The commercial finite element (FE software Abaqus® was used to calculate the response of the pavement when subjected to different loading, construction and geometrical configurations (i.e. type of analysis, shape and size of meshes, boundary conditions, and bonding contacts between the pavements layers. At the end of this study, a static model of a structure with hexahedral blocks having sides of 0.02 m, with full bonded layers and restrained horizontal displacements on the model sides, was implemented to evaluate the maximum tensile stress induced in a block when the load is applied at its centre. This analysis highlighted the need for rigorous criteria for a correct design, in order to avoid inappropriate and expensive use of road materials. Keywords: Block pavement, Commercial vehicle loads, Finite element model, Hexagonal Stone block, Pedestrian pavement, Shared area

  11. Responsive block copolymer photonics triggered by protein-polyelectrolyte coacervation.

    Science.gov (United States)

    Fan, Yin; Tang, Shengchang; Thomas, Edwin L; Olsen, Bradley D

    2014-11-25

    Ionic interactions between proteins and polyelectrolytes are demonstrated as a method to trigger responsive transitions in block copolymer (BCP) photonic gels containing one neutral hydrophobic block and one cationic hydrophilic block. Poly(2-vinylpyridine) (P2VP) blocks in lamellar poly(styrene-b-2-vinylpyridine) block copolymer thin films are quaternized with primary bromides to yield swollen gels that show strong reflectivity peaks in the visible range; exposure to aqueous solutions of various proteins alters the swelling ratios of the quaternized P2VP (QP2VP) gel layers in the PS-QP2VP materials due to the ionic interactions between proteins and the polyelectrolyte. Parameters such as charge density, hydrophobicity, and cross-link density of the QP2VP gel layers as well as the charge and size of the proteins play significant roles on the photonic responses of the BCP gels. Differences in the size and pH-dependent charge of proteins provide a basis for fingerprinting proteins based on their temporal and equilibrium photonic response. The results demonstrate that the BCP gels and their photonic effect provide a robust and visually interpretable method to differentiate different proteins.

  12. Physical Layer Design in Wireless Sensor Networks for Fading Mitigation

    Directory of Open Access Journals (Sweden)

    Nuo Chen

    2013-09-01

    Full Text Available This paper presents the theoretical analysis, simulation results and suggests design in digital technology of a physical layer for wireless sensor networks. The proposed design is able to mitigate fading inside communication channel. To mitigate fading the chip interleaving technique is proposed. For the proposed theoretical model of physical layer, a rigorous mathematical analysis is conducted, where all signals are presented and processed in discrete time domain form which is suitable for further direct processing necessary for devices design in digital technology. Three different channels are used to investigate characteristics of the physical layer: additive white Gaussian noise channel (AWGN, AWG noise and flat fading channel and AWG noise and flat fading channel with interleaver and deinterleaver blocks in the receiver and transmitter respectively. Firstly, the mathematical model of communication system representing physical layer is developed based on the discrete time domain signal representation and processing. In the existing theory, these signals and their processing are represented in continuous time form, which is not suitable for direct implementation in digital technology. Secondly, the expressions for the probability of chip, symbol and bit error are derived. Thirdly, the communication system simulators are developed in MATLAB. The simulation results confirmed theoretical findings.

  13. Optimal thickness of hole transport layer in doped OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y.C.; Zhou, J.; Zhao, J.M.; Zhang, S.T.; Zhan, Y.Q.; Wang, X.Z.; Wu, Y.; Ding, X.M.; Hou, X.Y. [Fudan University, Surface Physics Laboratory (National Key Laboratory), Shanghai (China)

    2006-06-15

    Current-voltage (I-V) and electroluminescence (EL) characteristics of organic light-emitting devices with N,N'-Di-[(1-naphthalenyl)-N,N'-diphenyl]-(1,1'-biphenyl)-4,4'-diamine (NPB) of various thicknesses as the hole transport layer, and tris(8-hydroxyquinoline)aluminum (Alq{sub 3}) selectively doped with 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran (DCM) as the electron transport layer, have been investigated. A trapped charge induced band bend model is proposed to explain the I-V characteristics. It is suggested that space charge changes the injection barrier and therefore influences the electron injection process in addition to the carrier transport process. Enhanced external quantum efficiency of the devices due to the electron blocking effect of an inserted NPB layer is observed. The optimal thickness of the NPB layer is experimentally determined to be 12{+-}3 nm in doped devices, a value different from that for undoped devices, which is attributed to the electron trap effect of DCM molecules. This is consistent with the result that the proportion of Alq{sub 3} luminescence in the total electroluminescence (EL) spectra increases with NPB thickness up to 12 nm under a fixed bias. (orig.)

  14. Low molecular weight block copolymers as plasticizers for polystyrene

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Karsten; Nielsen, Charlotte Juel; Hvilsted, Søren

    2005-01-01

    /mol and minimum polystyrene content of 50 w/w%, which by us is predicted as the limits for solubility of polystyrene-b-alkyl in polystyrene. DSC showed polystyrene was plasticized, as seen by a reduction in glass transition temperature, by block copolymers consisting of a polystyrene block with molecular weight...... of approximately 1 kg/mol and an alkyl block with a molecular weight of approximately of 0.3 kg/mol. The efficiency of the block copolymers as plasticizers increases with decreasing molecular weight and polystyrene content. In addition, polystyrene-b-alkyl is found to be an efficient plasticizer also...... for polystyrene-b-polyisoprene-b-polystyrene (SIS) block copolymers. The end use properties of SIS plasticized with polystyrene-b-alkyl, measured as tensile strength, is higher than for SIS plasticized with dioctyl adipate. The polystyrene-b-polybutadiene-b-polystyrene and polystyrene-bpoly(propylene glycol...

  15. Subcostal Transverse Abdominis Plane Block for Acute Pain Management: A Review.

    Science.gov (United States)

    Soliz, Jose M; Lipski, Ian; Hancher-Hodges, Shannon; Speer, Barbra Bryce; Popat, Keyuri

    2017-10-01

    The subcostal transverse abdominis plane (SCTAP) block is the deposition of local anesthetic in the transverse abdominis plane inferior and parallel to the costal margin. There is a growing consensus that the SCTAP block provides better analgesia for upper abdominal incisions than the traditional transverse abdominis plane block. In addition, when used as part of a four-quadrant transverse abdominis plane block, the SCTAP block may provide adequate analgesia for major abdominal surgery. The purpose of this review is to discuss the SCTAP block, including its indications, technique, local anesthetic solutions, and outcomes.

  16. Layer-by-Layer Method for the Synthesis and Growth of Surface Mounted Metal-Organic Frameworks (SURMOFs

    Directory of Open Access Journals (Sweden)

    Osama Shekhah

    2010-02-01

    Full Text Available A layer-by-layer method has been developed for the synthesis of metal-organic frameworks (MOFs and their deposition on functionalized organic surfaces. The approach is based on the sequential immersion of functionalized organic surfaces into solutions of the building blocks of the MOF, i.e., the organic ligand and the inorganic unit. The synthesis and growth of different types of MOFs on substrates with different functionalization, like COOH, OH and pyridine terminated surfaces, were studied and characterized with different surface characterization techniques. A controlled and highly oriented growth of very homogenous films was obtained using this method. The layer-by-layer method offered also the possibility to study the kinetics of film formation in more detail using surface plasmon resonance and quartz crystal microbalance. In addition, this method demonstrates the potential to synthesize new classes of MOFs not accessible by conventional methods. Finally, the controlled growth of MOF thin films is important for many applications like chemical sensors, membranes and related electrodes.

  17. A study on amphiphilic fluorinated block copolymer in graphite exfoliation using supercritical CO2 for stable graphene dispersion.

    Science.gov (United States)

    Kim, Young Hyun; Lee, Hyang Moo; Choi, Sung Wook; Cheong, In Woo

    2018-01-15

    In this study, poly(2,2,2-trifluoroethyl methacrylate)-block-poly(4-vinylpyridine) (PTFEMA-b-PVP) was synthesized by stepwise reversible addition-fragmentation chain transfer (RAFT) polymerization for the preparation of graphene by the exfoliation of graphite nanoplatelets (GPs) in supercritical CO 2 (SCCO 2 ). Two different block copolymers (low and high molecular weights) were prepared with the same block ratio and used at different concentrations in the SCCO 2 process. The amount of PTFEMA-b-PVP adsorbed on the GPs and the electrical conductivity of the SCCO 2 -treated GP samples were evaluated using thermogravimetric analysis (TGA) and four-point probe method, respectively. All GP samples treated with SCCO 2 were then dispersed in methanol and the dispersion stability was investigated using online turbidity measurements. The concentration and morphology of few-layer graphene stabilized with PTFEMA-b-PVP in the supernatant solution were investigated by gravimetry, scanning electron microscopy, and Raman spectroscopy. Destabilization study of the graphene dispersions revealed that the longer block copolymer exhibited better affinity for graphene, resulting in a higher yield of stable graphene with minimal defects. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Two injection digital block versus single subcutaneous palmar injection block for finger lacerations.

    Science.gov (United States)

    Okur, O M; Şener, A; Kavakli, H Ş; Çelik, G K; Doğan, N Ö; Içme, F; Günaydin, G P

    2017-12-01

    We aimed to compare two digital nerve block techniques in patients due to traumatic digital lacerations. This was a randomized-controlled study designed prospectively in the emergency department of a university-based training and research hospital. Randomization was achieved by sealed envelopes. Half of the patients were randomised to traditional (two-injection) digital nerve block technique while single-injection digital nerve block technique was applied to the other half. Score of pain due to anesthetic infiltration and suturing, onset time of total anesthesia, need for an additional rescue injection were the parameters evaluated with both groups. Epinephrin added lidocaine hydrochloride preparation was used for the anesthetic application. Visual analog scale was used for the evaluation of pain scores. Outcomes were compared by using Mann-Whitney U test and Student t-test. Fifty emergency department patients ≥18 years requiring digital nerve block were enrolled in the study. Mean age of the patients was 33 (min-max: 19-86) and 39 (78 %) were male. No statistically significant difference was found between the two groups in terms of our main parameters; anesthesia pain score, suturing pain score, onset time of total anesthesia and rescue injection need. Single injection volar digital nerve block technique is a suitable alternative for digital anesthesias in emergency departments.

  19. A gas production system from methane hydrate layers by hot water injection and BHP control with radial horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Yamakawa, T.; Ono, S.; Iwamoto, A.; Sugai, Y.; Sasaki, K. [Kyushu Univ., Fukuoka, Fukuoka (Japan)

    2010-07-01

    Reservoir characterization of methane hydrate (MH) bearing turbidite channel in the eastern Nankai Trough, in Japan has been performed to develop a gas production strategy. This paper proposed a gas production system from methane hydrate (MH) sediment layers by combining the hot water injection method and bottom hole pressure control at the production well using radial horizontal wells. Numerical simulations of the cylindrical homogeneous MH layer model were performed in order to evaluate gas production characteristics by the depressurization method with bottom hole pressure control. In addition, the effects of numerical block modeling and averaging physical properties of MH layers were presented. According to numerical simulations, combining the existing production system with hot water injection and bottom hole pressure control results in an outward expansion of the hot water chamber from the center of the MH layer with continuous gas production. 10 refs., 15 figs.

  20. Peatland restoration in Canada by the sphagnum moss layer transfer method

    Energy Technology Data Exchange (ETDEWEB)

    Rochefort, L.; Boismenu, C. [Laval Univ., Quebec City, PQ (Canada). Dept. de Phytologie, Peatland Ecology and Research Group; Quinty, F. [SNC-Lavalin, Montreal, PQ (Canada)

    2009-04-01

    This article described a peatland restoration approach that has received international recognition for restoring the ecological functions of cutover sphagnum dominated peatlands. The Peatland Ecology Research Group (PERG) conducted a long-term study at the Bois-des-Bel (BDB) peatland site in Quebec to restore plant composition to a peat accumulating ecosystem. The sphagnum moss layer transfer restoration method includes 5 obligatory steps and one optional. These include planning; surface preparation; plant collection and spreading; straw mulch spreading; blocking drainage ditches; and fertilization if needed. Variable moisture conditions throughout the restoration site contribute to the spatial variability in the development of the sphagnum layer. The site has been monitored each year since its restoration. sphagnum cover reached 60 per cent in the restored zone in 2005, a value close to the range of sphagnum cover found in natural sites. In addition, a new moss layer has developed with an average of 25 cm in thickness. 27 refs., 4 figs.

  1. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-08-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  2. Harmony of spinning conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Sobko, Evgeny [Stockholm Univ. (Sweden); Nordita, Stockholm (Sweden); Isachenkov, Mikhail [Weizmann Institute of Science, Rehovoth (Israel). Dept. of Particle Physics and Astrophysics

    2016-12-07

    Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

  3. Harmony of spinning conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Schomerus, Volker [DESY Hamburg, Theory Group,Notkestraße 85, 22607 Hamburg (Germany); Sobko, Evgeny [Nordita and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Isachenkov, Mikhail [Department of Particle Physics and Astrophysics, Weizmann Institute of Science,Rehovot 7610001 (Israel)

    2017-03-15

    Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

  4. Boundary-layer theory

    CERN Document Server

    Schlichting (Deceased), Hermann

    2017-01-01

    This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics). The new edition features an updated reference list and over 100 additional changes throughout the book, reflecting the latest advances on the subject.

  5. Additive manufacturing: From implants to organs

    African Journals Online (AJOL)

    Additive manufacturing (AM) constructs 3D objects layer by layer under computer control from 3D models. 3D printing is one ... anatomical models for surgery planning, and design and construction ... production of implants, particularly to replace bony structures, is ... Manufactured organs are, however, an elusive goal.

  6. Additive Layer Manufacturing of Biologically Inspired Short Fibre Reinforced Composites

    Science.gov (United States)

    2014-03-01

    ductile  fibre   coating  with  enhanced  mechanical...data   for   us   to   critically   assess   the   prospect   of   nanorod-­‐ coated   fibres  for  improved   ductility  in...fully   coated  with   zinc  acetate  seeds,  substrates   are  typically  dipped  in  the  solution  several  times

  7. Zero-block mode decision algorithm for H.264/AVC.

    Science.gov (United States)

    Lee, Yu-Ming; Lin, Yinyi

    2009-03-01

    In the previous paper , we proposed a zero-block intermode decision algorithm for H.264 video coding based upon the number of zero-blocks of 4 x 4 DCT coefficients between the current macroblock and the co-located macroblock. The proposed algorithm can achieve significant improvement in computation, but the computation performance is limited for high bit-rate coding. To improve computation efficiency, in this paper, we suggest an enhanced zero-block decision algorithm, which uses an early zero-block detection method to compute the number of zero-blocks instead of direct DCT and quantization (DCT/Q) calculation and incorporates two adequate decision methods into semi-stationary and nonstationary regions of a video sequence. In addition, the zero-block decision algorithm is also applied to the intramode prediction in the P frame. The enhanced zero-block decision algorithm brings out a reduction of average 27% of total encoding time compared to the zero-block decision algorithm.

  8. Nanocomposites from polymers and layered minerals

    NARCIS (Netherlands)

    Fischer, H.R.; Gielgens, L.H.; Koster, T.P.M.

    1999-01-01

    Composites consisting of polymer matrix materials and natural or synthetic layered minerals e.g. clays were prepared by using special compatibilizing agents betsveen these two intrinsically non-miscible components. Block or graft copolymers combining one part of the polymer that is identically

  9. Rolling block mazes are PSPACE-complete

    NARCIS (Netherlands)

    Buchin, K.; Buchin, M.

    2012-01-01

    In a rolling block maze, one or more blocks lie on a rectangular board with square cells. In most mazes, the blocks have size k × m × n where k, m, n are integers that determine the size of the block in terms of units of the size of the board cells. The task of a rolling block maze is to roll a

  10. Left bundle-branch block

    DEFF Research Database (Denmark)

    Risum, Niels; Strauss, David; Sogaard, Peter

    2013-01-01

    The relationship between myocardial electrical activation by electrocardiogram (ECG) and mechanical contraction by echocardiography in left bundle-branch block (LBBB) has never been clearly demonstrated. New strict criteria for LBBB based on a fundamental understanding of physiology have recently...

  11. Recursion Relations for Conformal Blocks

    CERN Document Server

    Penedones, João; Yamazaki, Masahito

    2016-09-12

    In the context of conformal field theories in general space-time dimension, we find all the possible singularities of the conformal blocks as functions of the scaling dimension $\\Delta$ of the exchanged operator. In particular, we argue, using representation theory of parabolic Verma modules, that in odd spacetime dimension the singularities are only simple poles. We discuss how to use this information to write recursion relations that determine the conformal blocks. We first recover the recursion relation introduced in 1307.6856 for conformal blocks of external scalar operators. We then generalize this recursion relation for the conformal blocks associated to the four point function of three scalar and one vector operator. Finally we specialize to the case in which the vector operator is a conserved current.

  12. Defying gravity using Jenga™ blocks

    Science.gov (United States)

    Tan, Yin-Soo; Yap, Kueh-Chin

    2007-11-01

    This paper describes how Jenga™ blocks can be used to demonstrate the physics of an overhanging tower that appears to defy gravity. We also propose ideas for how this demonstration can be adapted for the A-level physics curriculum.

  13. Risking Aggression: Reply to Block

    Directory of Open Access Journals (Sweden)

    Kris Borer

    2010-05-01

    Full Text Available In his paper, “Is There an ‘Anomalous’ Section of the Laffer Curve?”, Walter Block describes some situations in which it appears that a libertarian should violate the non-aggression principle. To rectify this, Block proposes a different perspective on libertarianism which he calls punishment theory. This paper argues that no new theory is needed, as the non-aggression principle can be used to resolve theapparent conundrums.

  14. Risking Aggression: Reply to Block

    OpenAIRE

    Kris Borer

    2010-01-01

    In his paper, “Is There an ‘Anomalous’ Section of the Laffer Curve?”, Walter Block describes some situations in which it appears that a libertarian should violate the non-aggression principle. To rectify this, Block proposes a different perspective on libertarianism which he calls punishment theory. This paper argues that no new theory is needed, as the non-aggression principle can be used to resolve theapparent conundrums.

  15. A Novel Tetrathiafulvalene Building Block

    DEFF Research Database (Denmark)

    Jeppesen, Jan Oskar; Takimiya, Kazuo; Thorup, Niels

    1999-01-01

    Efficient synthesis of a novel tetrathiafulvalene building block. 2,3-bis(2-cyanoethylthio)-6,7-bis(thiocyanato-methyl)tetrathiafulv alene (7) useful for stepwise and asymmetrical bis-function-alization is reported.......Efficient synthesis of a novel tetrathiafulvalene building block. 2,3-bis(2-cyanoethylthio)-6,7-bis(thiocyanato-methyl)tetrathiafulv alene (7) useful for stepwise and asymmetrical bis-function-alization is reported....

  16. Fibrinogen adsorption on blocked surface of albumin

    DEFF Research Database (Denmark)

    Holmberg, Maria; Hou, Xiaolin

    2011-01-01

    We have investigated the adsorption of albumin and fibrinogen onto PET (polyethylene terephthalate) and glass surfaces and how pre-adsorption of albumin onto these surfaces can affect the adsorption of later added fibrinogen. For materials and devices being exposed to blood, adsorption...... of fibrinogen is often a non-wanted event, since fibrinogen is part of the clotting cascade and unspecific adsorption of fibrinogen can have an influence on the activation of platelets. Albumin is often used as blocking agent for avoiding unspecific protein adsorption onto surfaces in devices designed to handle...... energies, the adsorption of both albumin and fibrinogen has been monitored simultaneously on the same sample. Information about topography and coverage of adsorbed protein layers has been obtained using AFM (Atomic Force Microscopy) analysis in liquid. Our studies show that albumin adsorbs in a multilayer...

  17. QuaBingo: A Prediction System for Protein Quaternary Structure Attributes Using Block Composition

    Directory of Open Access Journals (Sweden)

    Chi-Hua Tung

    2016-01-01

    Full Text Available Background. Quaternary structures of proteins are closely relevant to gene regulation, signal transduction, and many other biological functions of proteins. In the current study, a new method based on protein-conserved motif composition in block format for feature extraction is proposed, which is termed block composition. Results. The protein quaternary assembly states prediction system which combines blocks with functional domain composition, called QuaBingo, is constructed by three layers of classifiers that can categorize quaternary structural attributes of monomer, homooligomer, and heterooligomer. The building of the first layer classifier uses support vector machines (SVM based on blocks and functional domains of proteins, and the second layer SVM was utilized to process the outputs of the first layer. Finally, the result is determined by the Random Forest of the third layer. We compared the effectiveness of the combination of block composition, functional domain composition, and pseudoamino acid composition of the model. In the 11 kinds of functional protein families, QuaBingo is 23% of Matthews Correlation Coefficient (MCC higher than the existing prediction system. The results also revealed the biological characterization of the top five block compositions. Conclusions. QuaBingo provides better predictive ability for predicting the quaternary structural attributes of proteins.

  18. Two innovative solutions based on fibre concrete blocks designed for building substructure

    Science.gov (United States)

    Pazderka, J.; Hájek, P.

    2017-09-01

    Using of fibers in a high-strength concrete allows reduction of the dimensions of small precast concrete elements, which opens up new ways of solution for traditional construction details in buildings. The paper presents two innovative technical solutions for building substructure: The special shaped plinth block from fibre concrete and the fibre concrete elements for new technical solution of ventilated floor. The main advantages of plinth block from fibre concrete blocks (compared with standard plinth solutions) is: easier and faster assembly, higher durability and thanks to the air cavity between the vertical part of the block, the building substructure reduced moisture level of structures under the waterproofing layer and a comprehensive solution to the final surface of building plinth as well as the surface of adjacent terrain. The ventilated floor based on fibre concrete precast blocks is an attractive structural alternative for tackling the problem of increased moisture in masonry in older buildings, lacking a functional waterproof layer in the substructure.

  19. Recycled construction debris as an aggregates. Production of concrete blocks

    OpenAIRE

    Sousa, J. G. G.; Bauer, E.; Sposto, R. M.

    2003-01-01

    This paper analyzes the use of recycled construction and demolition debris as aggregate for the construction of concrete blocks to be used in sealing masonry. Initial studies addressed the definition of parameters used in the mix of conventional materials (traditionally used in the production of concrete blocks), involving cylindrical test specimens (100x200 mm), molded with the help of a vibratory table. In addition to these definitions, and based on the mixes showing the best results, a new...

  20. Functional polymers as nanoscopic building blocks

    International Nuclear Information System (INIS)

    Hernandez-Lopez, J.L.; Bauer, R.E.; Chang, W.-S.; Glasser, G.; Grebel-Koehler, D.; Klapper, M.; Kreiter, M.; Leclaire, J.; Majoral, J.-P.; Mittler, S.; Muellen, K.; Vasilev, K.; Weil, T.; Wu, J.; Zhu, T.; Knoll, W.

    2003-01-01

    Polyphenylene dendrimers are introduced as polymeric building blocks--with a strictly monodisperse particle size distribution within the nanometer range--for the construction of nanostructured materials and devices. The possibility for the introduction of different functionalities in the core, the scaffold or the periphery of the dendrimers offer their use as interesting modules for photonic, electronic or bioactive structures and supramolecular functional assemblies. Thus, dendrimers complement the available set of nanoscopic building blocks made from metals, e.g., Au nanoclusters and semiconductors, e.g., luminescent quantum dots. In a first set of experiments, we describe the fabrication of multilayer architectures using dendrimers with chargeable groups at the surface. This way, the polyelectrolyte deposition technique can be applied for the construction of hybrid layered assemblies with a control of the internal supramolecular structure at the nanometer level. Surface plasmon field-enhanced fluorescence spectroscopy is used to monitor the luminescent properties of dendrimers with a phthalocyanine core integrated into such a multilayer assembly. AFM and SEM micrographs demonstrate the use of surface-functionalized dendrimers (exposing sulfur groups at the periphery) in combination with Au nanoparticles for the controlled assembly of hybrid aggregates as nanoscopic functional devices

  1. Comparative study between ultrasound guided TAP block and paravertebral block in upper abdominal surgeries

    Directory of Open Access Journals (Sweden)

    Ruqaya M Elsayed Goda

    2017-01-01

    Conclusion: We concluded that ultrasound guided transverses abdominis plane block and thoracic paravertebral block were safe and effective anesthetic technique for upper abdominal surgery with longer and potent postoperative analgesia in thoracic paravertebral block than transverses abdominis block.

  2. Effect of ultrathin GeOx interfacial layer formed by thermal oxidation on Al2O3 capped Ge

    International Nuclear Information System (INIS)

    Han Le; Zhang Xiong; Wang Sheng-Kai; Xue Bai-Qing; Liu Hong-Gang; Wu Wang-Ran; Zhao Yi

    2014-01-01

    We propose a modified thermal oxidation method in which an Al 2 O 3 capping layer is used as an oxygen blocking layer (OBL) to form an ultrathin GeO x interfacial layer, and obtain a superior Al 2 O 3 /GeO x /Ge gate stack. The GeO x interfacial layer is formed in oxidation reaction by oxygen passing through the Al 2 O 3 OBL, in which the Al 2 O 3 layer could restrain the oxygen diffusion and suppress the GeO desorption during thermal treatment. The thickness of the GeO x interfacial layer would dramatically decrease as the thickness of Al 2 O 3 OBL increases, which is beneficial to achieving an ultrathin GeO x interfacial layer to satisfy the demand for small equivalent oxide thickness (EOT). In addition, the thickness of the GeO x interfacial layer has little influence on the passivation effect of the Al 2 O 3 /Ge interface. Ge (100) p-channel metal–oxide–semiconductor field-effect transistors (pMOSFETs) using the Al 2 O 3 /GeO x /Ge gate stacks exhibit excellent electrical characteristics; that is, a drain current on-off (I on /I off ) ratio of above 1×10 4 , a subthreshold slope of ∼ 120 mV/dec, and a peak hole mobility of 265 cm 2 /V·s are achieved. (condensed matter: structural, mechanical, and thermal properties)

  3. Diaphragm-Sparing Nerve Blocks for Shoulder Surgery.

    Science.gov (United States)

    Tran, De Q H; Elgueta, Maria Francisca; Aliste, Julian; Finlayson, Roderick J

    Shoulder surgery can result in significant postoperative pain. Interscalene brachial plexus blocks (ISBs) constitute the current criterion standard for analgesia but may be contraindicated in patients with pulmonary pathology due to the inherent risk of phrenic nerve block and symptomatic hemidiaphragmatic paralysis. Although ultrasound-guided ISB with small volumes (5 mL), dilute local anesthetic (LA) concentrations, and LA injection 4 mm lateral to the brachial plexus have been shown to reduce the risk of phrenic nerve block, no single intervention can decrease its incidence below 20%. Ultrasound-guided supraclavicular blocks with LA injection posterolateral to the brachial plexus may anesthetize the shoulder without incidental diaphragmatic dysfunction, but further confirmatory trials are required. Ultrasound-guided C7 root blocks also seem to offer an attractive, diaphragm-sparing alternative to ISB. However, additional large-scale studies are needed to confirm their efficacy and to quantify the risk of periforaminal vascular breach. Combined axillary-suprascapular nerve blocks may provide adequate postoperative analgesia for minor shoulder surgery but do not compare favorably to ISB for major surgical procedures. One intriguing solution lies in the combined use of infraclavicular brachial plexus blocks and suprascapular nerve blocks. Theoretically, the infraclavicular approach targets the posterior and lateral cords, thus anesthetizing the axillary nerve (which supplies the anterior and posterior shoulder joint), as well as the subscapular and lateral pectoral nerves (both of which supply the anterior shoulder joint), whereas the suprascapular nerve block anesthetizes the posterior shoulder. Future randomized trials are required to validate the efficacy of combined infraclavicular-suprascapular blocks for shoulder surgery.

  4. Block Storage Service: Status and Performance

    CERN Document Server

    Van der Ster, Daniel

    2014-01-01

    This memo summarizes the current status of the Ceph block storage service as it is used for OpenStack Cinder Volumes and Glance Images as of May 2014. We present the block storage activity on the current cluster, measuring IOPS and latencies, and present a cost/benefit analysis of using SSDs to optimize the cost and performance efficiency of the service. During tests in collaboration with IT-CF, we have concluded that by adding SSDs as the synchronous write journals (used to guarantee data durability), we are able increase the IOPS capacity by 4-5 times, at a cost of decreasing the available volume by 20%. Further, the testing has shown that the Ceph implementation is able to operate at the limit of the hardware performance; software-induced performance limitations were not yet observed in either the spinning disk or SSD configurations. In addition, we believe that increasing small write performance with SSDs is applicable only to the block storage use-case; high-bandwidth use-cases such as physics data stora...

  5. The Breakdown: Hillslope Sources of Channel Blocks in Bedrock Landscapes

    Science.gov (United States)

    Selander, B.; Anderson, S. P.; Rossi, M.

    2017-12-01

    Block delivery from hillslopes is a poorly understood process that influences bedrock channel incision rates and shapes steep terrain. Previous studies demonstrate that hillslope sediment delivery rate and grain size increases with channel downcutting rate or fracture density (Attal et al., 2015, ESurf). However, blocks that exceed the competence of the channel can inhibit incision. In Boulder Creek, a bedrock channel in the Colorado Front Range, large boulders (>1 m diameter) are most numerous in the steepest channel reaches; their distribution seems to reflect autogenic channel-hillslope feedback between incision rate and block delivery (Shobe et al., 2016, GRL). It is clear that the processes, rates of production, and delivery of large blocks from hillslopes into channels are critical to our understanding of steep terrain evolution. Fundamental questions are 1) whether block production or block delivery is rate limiting, 2) what mechanisms release blocks, and 3) how block production and transport affect slope morphology. As a first step, we map rock outcrops on the granodiorite hillslopes lining Boulder Creek within Boulder Canyon using a high resolution DEM. Our algorithm uses high ranges of curvature values in conjunction with slopes steeper than the angle of repose to quickly identify rock outcrops. We field verified mapped outcrop and sediment-mantled locations on hillslopes above and below the channel knickzone. We find a greater abundance of exposed rock outcrops on steeper hillslopes in Boulder Canyon. Additionally, we find that channel reaches with large in-channel blocks are located at the base of hillslopes with large areas of exposed bedrock, while reaches lacking large in-channel blocks tend to be at the base of predominately soil mantled and forested hillslopes. These observations support the model of block delivery and channel incision of Shobe et al. (2016, GRL). Moreover, these results highlight the conundrum of how rapid channel incision is

  6. Various semiclassical limits of torus conformal blocks

    Energy Technology Data Exchange (ETDEWEB)

    Alkalaev, Konstantin [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky ave. 53, Moscow, 119991 (Russian Federation); Department of General and Applied Physics, Moscow Institute of Physics and Technology,Institutskiy per. 7, Dolgoprudnyi, Moscow region, 141700 (Russian Federation); Geiko, Roman [Mathematics Department, National Research University Higher School of Economics,Usacheva str. 6, Moscow, 119048 (Russian Federation); Rappoport, Vladimir [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky ave. 53, Moscow, 119991 (Russian Federation); Department of Quantum Physics, Institute for Information Transmission Problems,Bolshoy Karetny per. 19, Moscow, 127994 (Russian Federation)

    2017-04-12

    We study four types of one-point torus blocks arising in the large central charge regime. There are the global block, the light block, the heavy-light block, and the linearized classical block, according to different regimes of conformal dimensions. It is shown that the blocks are not independent being connected to each other by various links. We find that the global, light, and heavy-light blocks correspond to three different contractions of the Virasoro algebra. Also, we formulate the c-recursive representation of the one-point torus blocks which is relevant in the semiclassical approximation.

  7. Growing Embossed Nanostructures of Polymer Brushes on Wet-Etched Silicon Templated via Block Copolymers

    Science.gov (United States)

    Lu, Xiaobin; Yan, Qin; Ma, Yinzhou; Guo, Xin; Xiao, Shou-Jun

    2016-02-01

    Block copolymer nanolithography has attracted enormous interest in chip technologies, such as integrated silicon chips and biochips, due to its large-scale and mass production of uniform patterns. We further modified this technology to grow embossed nanodots, nanorods, and nanofingerprints of polymer brushes on silicon from their corresponding wet-etched nanostructures covered with pendent SiHx (X = 1-3) species. Atomic force microscopy (AFM) was used to image the topomorphologies, and multiple transmission-reflection infrared spectroscopy (MTR-IR) was used to monitor the surface molecular films in each step for the sequential stepwise reactions. In addition, two layers of polymethacrylic acid (PMAA) brush nanodots were observed, which were attributed to the circumferential convergence growth and the diffusion-limited growth of the polymer brushes. The pH response of PMAA nanodots in the same region was investigated by AFM from pH 3.0 to 9.0.

  8. Transfer of Training in Simple Addition.

    Science.gov (United States)

    Chen, Yalin; Campbell, Jamie I D

    2017-04-18

    In recent years several researchers have proposed that skilled adults may solve single-digit addition problems (e.g. 3 + 1 = 4, 4 + 3 = 7) using a fast counting procedure. Practicing a procedure, often leads to transfer of learning and faster performance of unpracticed items. Such transfer has been demonstrated using a counting-based alphabet arithmetic task (e.g., B + 4 = C D E F) that indicated robust generalization of practice (i.e., RT gains) when untrained transfer problems at test had been implicitly practiced (e.g., practice B + 3, test B + 2 or B + 1). Here we constructed analogous simple addition problems (practice 4 + 3, test 4 + 2 or 4 + 1). In each of three experiments (total n = 108) participants received six practice blocks followed by two test blocks of new problems to examine generalization effects. Practice of addition identity-rule problems (i.e., 0 + N = N) showed complete transfer of RT gains made during practice to unpracticed items at test. In contrast, the addition ties (2 + 2, 3 + 3, etc.) presented large RT costs for unpracticed problems at test, but sped up substantially in the second test block. This pattern is consistent with item-specific strengthening of associative memory. The critical items were small non-tie additions (sum ≤ 10) for which the test problems would be implicitly practiced if counting was employed during practice. In all three experiments (and collectively) there was no evidence of generalization for these items in the first test block, but there was robust speed up when the items were repeated in the second test block. Thus, there was no evidence of the generalization of practice that would be expected if counting procedures mediated our participants' performance on small non-tie addition problems.

  9. Bier′s block using lignocaine and butorphanol

    Directory of Open Access Journals (Sweden)

    Abhishek Bansal

    2011-01-01

    Full Text Available Background : Opioids are most commonly used as adjuncts in intravenous regional anesthesia (IVRA to improve the quality of intraoperative and postoperative analgesia. There is paucity of literature on the use of butorphanol in IVRA. Aims : The aim of this study was to evaluate the likely benefits of addition of butorphanol to lignocaine in Bier′s block in terms of onset and duration of sensory block and also for analgesic requirement in postoperative period. Settings and Design : A randomized double blind study was conducted at Tertiary Care Educational Institute. Patients and Methods : A total of 40 adult ASA I or II patients scheduled to undergo upper limb surgery were randomized in two groups (n=20. Group I received 3 mg/kg of lignocaine alone and group II received 1 mg butorphanol in addition to 3 mg/kg lignocaine. Sensory block onset time and time to recovery from sensory block after tourniquet deflation were noted using the pin prick method. Duration of postoperative analgesia was noted using a visual analogue scale. All the patients were compared for the time to first rescue analgesic consumption and total analgesic consumption in first 24 hours postoperatively. Statistical Analysis Used : The statistical analysis was done using unpaired Student′s t-test. Results : Our study showed significant prolongation of postoperative analgesia in group II as noted by the time to first analgesic requirement. Total analgesic consumption in first 24 hours postoperatively was less in group II. Sensory block onset time and time to recovery from sensory block after tourniquet deflation, did not show any significant difference between the two groups. Conclusions : Addition of butorphanol to lignocaine in IVRA significantly prolongs the duration of postoperative analgesia and 24 hours analgesic consumption is less in patients receiving butorphanol along with lignocaine in IVRA. However, there is no effect on sensory block onset time and time to recovery

  10. Analysis in cytokinesis-blocked human lymphocytes

    International Nuclear Information System (INIS)

    Catena, C.; Mattoni, A.

    1987-01-01

    Biological dosimetry can be considered as an additional method to physical dosimetry for estimating dose absorption after exposure to ionizing radiation. Fully validated as well as new promising approaches in this field are reviewed. Recent experiments, carried out in our laboratory, on the analysis of micronuclei in cytokinesis-blocked human lymphocytes are presented. The possible relevance of differential human individual response to ionizing radiation, in view of the occurrence of radiosensitive syndromes, for the estimation of the absorbed dose in human is also discussed

  11. Crack layer theory

    Science.gov (United States)

    Chudnovsky, A.

    1987-01-01

    A damage parameter is introduced in addition to conventional parameters of continuum mechanics and consider a crack surrounded by an array of microdefects within the continuum mechanics framework. A system consisting of the main crack and surrounding damage is called crack layer (CL). Crack layer propagation is an irreversible process. The general framework of the thermodynamics of irreversible processes are employed to identify the driving forces (causes) and to derive the constitutive equation of CL propagation, that is, the relationship between the rates of the crack growth and damage dissemination from one side and the conjugated thermodynamic forces from another. The proposed law of CL propagation is in good agreement with the experimental data on fatigue CL propagation in various materials. The theory also elaborates material toughness characterization.

  12. Gravitational double layers

    International Nuclear Information System (INIS)

    Senovilla, José M M

    2014-01-01

    I analyze the properties of thin shells through which the scalar curvature R is discontinuous in gravity theories with Lagrangian F(R) = R − 2Λ + αR 2 on the bulk. These shells/domain walls are of a new kind because they possess, in addition to the standard energy–momentum tensor, an external energy flux vector, an external scalar pressure/tension and, most exotic of all, another energy–momentum contribution resembling classical dipole distributions on a shell: a double layer. I prove that all these contributions are necessary to make the entire energy–momentum tensor divergence-free. This is the first known occurrence of such a type of double layer in a gravity theory. I present explicit examples in constant-curvature five-dimensional bulks, with a brief study of their properties: new physical behaviors arise. (fast track communications)

  13. Surgical anesthesia with a combination of T12 paravertebral block and lumbar plexus, sacral plexus block for hip replacement in ankylosing spondylitis: CARE-compliant 4 case reports.

    Science.gov (United States)

    Ke, Xijian; Li, Ji; Liu, Yong; Wu, Xi; Mei, Wei

    2017-06-26

    Anesthesia management for patients with severe ankylosing spondylitis scheduled for total hip arthroplasty is challenging due to a potential difficult airway and difficult neuraxial block. We report 4 cases with ankylosing spondylitis successfully managed with a combination of lumbar plexus, sacral plexus and T12 paravertebral block. Four patients were scheduled for total hip arthroplasty. All of them were diagnosed as severe ankylosing spondylitis with rigidity and immobilization of cervical and lumbar spine and hip joints. A combination of T12 paravertebral block, lumbar plexus and sacral plexus block was successfully used for the surgery without any additional intravenous anesthetic or local anesthetics infiltration to the incision, and none of the patients complained of discomfort during the operations. The combination of T12 paravertebral block, lumbar plexus and sacral plexus block, which may block all nerves innervating the articular capsule, surrounding muscles and the skin involved in total hip arthroplasty, might be a promising alternative for total hip arthroplasty in ankylosing spondylitis.

  14. Plasma-assisted atomic layer deposition of TiO2 compact layers for flexible mesostructured perovskite solar cells

    NARCIS (Netherlands)

    Zardetto, V.; Di Giacomo, F.; Lucarelli, G.; Kessels, W.M.M.; Brown, T.M.; Creatore, M.

    2017-01-01

    In mesostructured perovskite solar cell devices, charge recombination processes at the interface between the transparent conductive oxide, perovskite and hole transport layer are suppressed by depositing an efficient compact TiO2 blocking layer. In this contribution we investigate the role of the

  15. Climatological features of blocking anticyclones

    International Nuclear Information System (INIS)

    Lupo, A.R.; Smith, P.J.; Oglesby, R.J.

    1994-01-01

    Several climatological studies have been previously performed using large observational data sets (i.e., 10 years or longer) in order to determine the predominant characteristics of blocking anticyclones, including favored development regions, duration, preferred seasonal occurrence, and frequency of occurrence. These studies have shown that blocking anticyclones occur most frequently from October to April over the eastern Atlantic and Pacific oceans downstream from both the North American and Asian continental regions and the storm track regions to the east of these continents. Some studies have also revealed the presence of a third region block formation in western Russia near 40 degrees E which is associated with another storm track region over the Mediterranean and western Asia

  16. MITRE sensor layer prototype

    Science.gov (United States)

    Duff, Francis; McGarry, Donald; Zasada, David; Foote, Scott

    2009-05-01

    and location of data sought by multiple processes to the attention of each processing station, just that specifically sought data is downloaded to each process application. The Sensor Layer Prototype participated in a proof-of-concept demonstration in April 2008. This event allowed multiple MITRE innovation programs to interact among themselves to demonstrate the ability to couple value-adding but previously unanticipated users to the enterprise. For this event, the Sensor Layer Prototype was used to show data entering the environment in real time. Multiple data types were encapsulated and added to the database via the Sensor Layer Prototype, specifically National Imagery Transmission Format 2.1 (NITF), NATO Standardization Format 4607 (STANAG 4607), Cursor-on-Target (CoT), Joint Photographic Experts Group (JPEG), Hierarchical Data Format (HDF5) and several additional sensor file formats describing multiple sensors addressing a common scenario.

  17. Block ground interaction of rockfalls

    Science.gov (United States)

    Volkwein, Axel; Gerber, Werner; Kummer, Peter

    2016-04-01

    During a rockfall the interaction of the falling block with the ground is one of the most important factors that define the evolution of a rockfall trajectory. It steers the rebound, the rotational movement, possibly brake effects, friction losses and damping effects. Therefore, if most reliable rockfall /trajectory simulation software is sought a good understanding of the block ground interaction is necessary. Today's rockfall codes enable the simulation of a fully 3D modelled block within a full 3D surface . However, the details during the contact, i.e. the contact duration, the penetration depth or the dimension of the marks in the ground are usually not part of the simulation. Recent field tests with rocks between 20 and 80 kg have been conducted on a grassy slope in 2014 [1]. A special rockfall sensor [2] within the blocks measured the rotational velocity and the acting accelerations during the tests. External video records and a so-called LocalPositioningSystem deliver information on the travel velocity. With these data not only the flight phases of the trajectories but also the contacts with the ground can be analysed. During the single jumps of a block the flight time, jump length, the velocity, and the rotation are known. During the single impacts their duration and the acting accelerations are visible. Further, the changes of rotational and translational velocity influence the next jump of the block. The change of the rotational velocity over the whole trajectory nicely visualizes the different phases of a rockfall regarding general acceleration and deceleration in respect to the inclination and the topography of the field. References: [1] Volkwein A, Krummenacher B, Gerber W, Lardon J, Gees F, Brügger L, Ott T (2015) Repeated controlled rockfall trajectory testing. [Abstract] Geophys. Res. Abstr. 17: EGU2015-9779. [2] Volkwein A, Klette J (2014) Semi-Automatic Determination of Rockfall Trajectories. Sensors 14: 18187-18210.

  18. Sodium Exposure Tests on Limestone Concrete Used as Sacrificial Protection Layer in FBR

    International Nuclear Information System (INIS)

    Parida, F.C.; Das, S.K.; Sharma, A.K.; Rao, P.M.; Ramesh, S.S.; Somayajulu, P.A.; Malarvizhi, B.; Kasinathan, N.

    2006-01-01

    Hot sodium coming in contact with structural concrete in case of sodium leak in FBR system cause damage as a result of thermo-chemical attack by burning sodium. In addition, release of free and bound water from concrete leads to generation of hydrogen gas, which is explosive in nature. Hence limestone concrete, as sacrificial layer on the structural concrete in FBR, needs to be qualified. Four concrete blocks of dimension 600 mm x 600 mm x 300 mm with 300 mm x 300 mm x 150 mm cavity were cast and subjected to controlled sodium exposure tests. They have composition of ordinary portland cement, water, fine and coarse aggregate of limestone in the ratio of 1: 0.58: 2.547: 3.817. These blocks were subjected to preliminary inspection by ultrasonic pulse velocity technique and rebound hammer tests. Each block was exposed for 30 minutes to about 12 kg of liquid sodium (∼ 120 mm liquid column) at 550 deg. C in open air, after which sodium was sucked back from the cavity of the concrete block into a sodium tank. On-line temperature monitoring was carried out at strategic locations of sodium pool and concrete block. After removing sodium from the cavity and cleaning the surfaces, rebound hammer testing was carried out on each concrete block at the same locations where data were taken earlier at pre-exposed stage. The statistical analysis of rebound hammer data revealed that one of the concrete block alone has undergone damage to the extent of 16%. The loss of mass occurred for all the four blocks varied from 0.6 to 2.4% due to release of water during the test duration. Chemical analysis of sodium in concrete samples collected from cavity floor of each block helped in generation of depth profiles of sodium monoxide concentration for each block. From this it is concluded that a bulk penetration of sodium up to 30 mm depth has taken place. However it was also observed that at few local spots, sodium penetrated into concrete up to 50 mm. Cylindrical core samples of 50 mm x 150

  19. Cryptanalysis of Selected Block Ciphers

    DEFF Research Database (Denmark)

    Alkhzaimi, Hoda A.

    , pseudorandom number generators, and authenticated encryption designs. For this reason a multitude of initiatives over the years has been established to provide a secure and sound designs for block ciphers as in the calls for Data Encryption Standard (DES) and Advanced Encryption Standard (AES), lightweight...... ciphers initiatives, and the Competition for Authenticated Encryption: Security, Applicability, and Robustness (CAESAR). In this thesis, we first present cryptanalytic results on different ciphers. We propose attack named the Invariant Subspace Attack. It is utilized to break the full block cipher...

  20. Block Textured a-Si:H Solar Cell

    Directory of Open Access Journals (Sweden)

    Seung Jae Moon

    2014-01-01

    Full Text Available A series of etching experiments on light trapping structure have been carried out by glass etching. The block structure provides long light traveling path and a constant distance between the cathode and anode electrodes regardless of the block height, which results in higher efficiency of the block textured solar cell. In terms of etching profile of the glass substrate, the addition of NH4F resulted in the smooth and clean etching profile, and the steep slope of the block was obtained by optimizing the composition of etching solution. For a higher HF concentration, a more graded slope was obtained and the addition of HNO3 and NH4F provided steep slope and clean etching profile. The effects of the block textured glass were verified by a comparison of the solar cell efficiency. For the textured solar cell, the surface was much rougher than that of the plain glass, which also contributes to the improvement of the efficiency. We accomplished block shaped light trapping structure for the first time by wet etching of the glass substrate, which enables the high efficiency thin film solar cell with the aid of the good step coverage deposition.

  1. Increase of rotation angle of soil layers during plow operation

    Science.gov (United States)

    Vasilenko, VV; Afonichev, D. N.; Vasilenko, S. V.; Khakhulin, A. N.

    2018-03-01

    One of the advantages of plowing is the ability of the plow to hide the weed seeds deep into the soil. The depth of the embankment exceeds 10-12 cm, from there the weeds can not rise to the surface of the soil. They perish halfway. But for this, it is necessary to wrap the soil layers at an angle close to 180 °. Modern ploughs can not turn the layers of soil at an angle of more than 135 °, therefore the plow is required to be equipped with additional working elements. The aim of the study is to create an adaptation to the plow to expand the furrow before laying the next soil layer. In a wide furrow, the formation will completely tip, the previous layer will not interfere with it. The device is a set of vertical shields. Each shield is fixed behind the working body of the plow. It is installed with an angle of attack of 20-25 ° to move the previous layer to expand the furrow by 10-12 cm. The model and industrial samples of the plow have shown improved agrotechnical indicators. The average angle of the formation rotation was 177 °, the burial of plant residues in the soil increased from 61 to 99%. The field surface with blocks more than 5 cm decreased from 36.3 to 13.4%, the height of the ridges decreased from 7 to 4 cm. The force of soil pressure on the shield was measured by a strain gage. It is 130-330 N depending on the depth of processing and the speed of movement. The increase in power costs for the four-hull plow was 190-750 W. The coulters on the plow are unnecessary, and this saves energy more than its increase for shields.

  2. SIMULATION AND INVESTIGATION OF TIRE TREAD BLOCKS INTERACTION WITH ICE

    Directory of Open Access Journals (Sweden)

    Andrius Ružinskas

    2017-12-01

    Full Text Available The car tire is an essential subject analysing its interaction with the road. From tire’s tread condition, geometry and rubber compound depends grip and vehicle stability. This is especially relevant in winter time, when roads are covered with the layer of snow or ice. Generally, new tires are tested in real traffic conditions using vehicles. However, ensuring these conditions requires many resources and sometimes it could be a big challenge. For this reason, simulation of the tire interaction with the road becomes more important in nowadays tire researches. Since the tire is a complex engineering subject, the tire tread blocks could be separated for individual analysis. The interaction between the dry ice and the tread block with sipes was analysed using finite element analysis. The tread block was described using hyperelastic Mooney­Rivlin material model. The deformations, distribution of the contact pressure and shear stresses were obtained for the soft and hard rubber compounds with different vertical load conditions. Also a solid tread block interaction was analysed and it was found that values of contact pressure and shear stresses are much lower comparing to siped tread block.

  3. Layering and Ordering in Electrochemical Double Layers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yihua [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States; Kawaguchi, Tomoya [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States; Pierce, Michael S. [Rochester Institute of Technology, School of Physics and Astronomy, Rochester, New York 14623, United States; Komanicky, Vladimir [Faculty of Science, Safarik University, 041 54 Kosice, Slovakia; You, Hoydoo [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States

    2018-02-26

    Electrochemical double layers (EDL) form at electrified interfaces. While Gouy-Chapman model describes moderately charged EDL, formation of Stern layers was predicted for highly charged EDL. Our results provide structural evidence for a Stern layer of cations, at potentials close to hydrogen evolution in alkali fluoride and chloride electrolytes. Layering was observed by x-ray crystal truncation rods and atomic-scale recoil responses of Pt(111) surface layers. Ordering in the layer is confirmed by glancing-incidence in-plane diffraction measurements.

  4. Optimization of the key geological target parameters of shale-gas horizontal wells in the Changning Block, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Hongzhi Yang

    2016-12-01

    Full Text Available In recent years, great progress has been made in geologic evaluation, engineering test and development optimization of the Lower Cambrian Wufeng Fm–Lower Silurian Longmaxi Fm shale gas in the Sichuan Basin, and the main shale gas exploitation technologies have been understood preliminarily. In addition, scale productivity construction has been completed in Jiaoshiba, Changning and Weiyuan blocks. In this paper, the Wufeng Fm–Longmaxi Fm shale gas wells in Changning Block were taken as the study object to provide technical reference for the development design of similar shale-gas horizontal wells. The technology combining geology with engineering, dynamic with static, and statistical analysis with simulation prediction was applied to quantify the main factors controlling shale-gas well productivity, develop the shale-gas well production prediction model, and optimize the key technical parameters of geologic target of shale-gas horizontal wells in the block (e.g. roadway orientation, location and spacing, horizontal section length and gas well production index. In order to realize high productivity of shale gas wells, it is necessary to maximize the included angle between the horizontal section orientation and the maximum major stress and fracture development direction, deploy horizontal-well roadway in top-quality shale layers, and drill the horizontal section in type I reservoirs over 1000 m long. It is concluded that high productivity of shale gas wells is guaranteed by the horizontal-well wellbore integrity and the optimized low-viscosity slickwater and ceramsite fracturing technology for complex fracture creation. Based on the research results, the technical policies for shale gas development of Changning Block are prepared and a guidance and reference are provided for the shale gas development and productivity construction in the block and the development design of similar shale-gas horizontal wells.

  5. Asymmetric PS-block-(PS-co-PB)-block-PS block copolymers: morphology formation and deformation behaviour

    International Nuclear Information System (INIS)

    Adhikari, Rameshwar; Huy, Trinh An; Buschnakowski, Matthias; Michler, Goerg H; Knoll, Konrad

    2004-01-01

    Morphology formation and deformation behaviour of asymmetric styrene/butadiene triblock copolymers (total polystyrene (PS) content ∼70%) consisting of PS outer blocks held apart by a styrene-co-butadiene random copolymer block (PS-co-PB) each were investigated. The techniques used were differential scanning calorimetry, transmission electron microscopy, uniaxial tensile testing and Fourier-transform infrared spectroscopy. A significant shift of the phase behaviour relative to that of a neat symmetric triblock copolymer was observed, which can be attributed to the asymmetric architecture and the presence of PS-co-PB as a soft block. The mechanical properties and the microdeformation phenomena were mainly controlled by the nature of their solid-state morphology. Independent of morphology type, the soft phase was found to deform to a significantly higher degree of orientation when compared with the hard phase

  6. Effect of block composition on thermal properties and melt viscosity of poly[2-(dimethylaminoethyl methacrylate], poly(ethylene oxide and poly(propylene oxide block co-polymers

    Directory of Open Access Journals (Sweden)

    2011-09-01

    Full Text Available To modify the rheological properties of certain commercial polymers, a set of block copolymers were synthesized through oxyanionic polymerization of 2-(dimethylaminoethyl methacrylate to the chain ends of commercial prepolymers, namely poly(ethylene oxide (PEO, poly(ethylene oxide-block-poly(propylene oxide-block-poly(ethylene oxide (PEO-PPO-PEO, and poly(propylene oxide (PPO. The formed block copolymers were analysed with size exclusion chromatography and nuclear magnetic resonance spectroscopy in order to confirm block formation. Thermal characterization of the resulting polymers was done with differential scanning calorimetry. Thermal transition points were also confirmed with rotational rheometry, which was primarily used to measure melt strength properties of the resulting block co-polymers. It was observed that the synthesised poly[2-(dimethylaminoethyl methacrylate]-block (PDM affected slightly the thermal transition points of crystalline PEO-block but the influence was stronger on amorphous PPO-blocks. Frequency sweeps measured above the melting temperatures for the materials confirmed that the pre-polymers (PEO and PEO-PPO-PEO behave as Newtonian fluids whereas polymers with a PDM block structure exhibit clear shear thinning behaviour. In addition, the PDM block increased the melt viscosity when compared with that one of the pre-polymer. As a final result, it became obvious that pre-polymers modified with PDM were in entangled form, in the melted state as well in the solidified form.

  7. Main-chain supramolecular block copolymers.

    Science.gov (United States)

    Yang, Si Kyung; Ambade, Ashootosh V; Weck, Marcus

    2011-01-01

    Block copolymers are key building blocks for a variety of applications ranging from electronic devices to drug delivery. The material properties of block copolymers can be tuned and potentially improved by introducing noncovalent interactions in place of covalent linkages between polymeric blocks resulting in the formation of supramolecular block copolymers. Such materials combine the microphase separation behavior inherent to block copolymers with the responsiveness of supramolecular materials thereby affording dynamic and reversible materials. This tutorial review covers recent advances in main-chain supramolecular block copolymers and describes the design principles, synthetic approaches, advantages, and potential applications.

  8. Layered double hydroxides

    DEFF Research Database (Denmark)

    López Rayo, Sandra; Imran, Ahmad; Hansen, Hans Chr. Bruun

    2017-01-01

    A novel zinc (Zn) fertilizer concept based on Zn doped layered double hydroxides (Zn-doped Mg-Fe-LDHs) has been investigated. Zn-doped Mg-Fe-LDHs were synthetized, their chemical composition was analyzed and their nutrient release was studied in buffered solutions with different pH values. Uptake...... equation showing maximum release at pH 5.2, reaching approximately 45% of the total Zn content. The Zn concentrations in the plants receiving the LDHs were between 2- and 9.5-fold higher than those in plants without Zn addition. A positive effect of the LDHs was also found in soil. This work documents...

  9. Smart ampholytic ABC block copolypeptide

    Czech Academy of Sciences Publication Activity Database

    Schlaad, H.; Sun, J.; Černoch, Peter; Ruokolainen, J.

    2017-01-01

    Roč. 254, 20 August (2017), s. 79 ISSN 0065-7727. [ACS National Meeting & Exposition /254./. 20.08.2017-24.08.2017, Washington] Institutional support: RVO:61389013 Keywords : block copolypeptide * smart ampholytic Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science

  10. First Degree Pacemaker Exit Block

    Directory of Open Access Journals (Sweden)

    Johnson Francis

    2016-10-01

    Full Text Available Usually atrial and ventricular depolarizations follow soon after the pacemaker stimulus (spike on the ECG. But there can be an exit block due to fibrosis at the electrode - tissue interface at the lead tip. This can increase the delay between the spike and atrial or ventricular depolarization.

  11. Building Blocks for Personal Brands

    Science.gov (United States)

    Thomas, Lisa Carlucci

    2011-01-01

    In this article, the author discusses the four essential building blocks for personal brands: (1) name; (2) message; (3) channels; and (4) bridges. However, outstanding building materials can only take a person so far. The author emphasizes that vision, determination, faith, a sense of humor, and humility are also required.

  12. Thermo-responsive block copolymers

    NARCIS (Netherlands)

    Mocan Cetintas, Merve

    2017-01-01

    Block copolymers (BCPs) are remarkable materials because of their self-assembly behavior into nano-sized regular structures and high tunable properties. BCPs are in used various applications such as surfactants, nanolithography, biomedicine and nanoporous membranes. In these thesis, we aimed to

  13. Cervical plexus block for thyroidectomy

    African Journals Online (AJOL)

    Adele

    RESEARCH. Southern African Journal of Anaesthesia & Analgesia - November 2003 ... Cervical plexus block has also been found useful for thy- .... lar, transverse cervical and supraclavicular nerves. ... administration of midazolam and pentazocine as required. ... find out if there were postoperative complications specific to.

  14. Blocking sets in Desarguesian planes

    NARCIS (Netherlands)

    Blokhuis, A.; Miklós, D.; Sós, V.T.; Szönyi, T.

    1996-01-01

    We survey recent results concerning the size of blocking sets in desarguesian projective and affine planes, and implications of these results and the technique to prove them, to related problemis, such as the size of maximal partial spreads, small complete arcs, small strong representative systems

  15. Patchy micelles based on coassembly of block copolymer chains and block copolymer brushes on silica particles.

    Science.gov (United States)

    Zhu, Shuzhe; Li, Zhan-Wei; Zhao, Hanying

    2015-04-14

    Patchy particles are a type of colloidal particles with one or more well-defined patches on the surfaces. The patchy particles with multiple compositions and functionalities have found wide applications from the fundamental studies to practical uses. In this research patchy micelles with thiol groups in the patches were prepared based on coassembly of free block copolymer chains and block copolymer brushes on silica particles. Thiol-terminated and cyanoisopropyl-capped polystyrene-block-poly(N-isopropylacrylamide) block copolymers (PS-b-PNIPAM-SH and PS-b-PNIPAM-CIP) were synthesized by reversible addition-fragmentation chain transfer polymerization and chemical modifications. Pyridyl disulfide-functionalized silica particles (SiO2-SS-Py) were prepared by four-step surface chemical reactions. PS-b-PNIPAM brushes on silica particles were prepared by thiol-disulfide exchange reaction between PS-b-PNIPAM-SH and SiO2-SS-Py. Surface micelles on silica particles were prepared by coassembly of PS-b-PNIPAM-CIP and block copolymer brushes. Upon cleavage of the surface micelles from silica particles, patchy micelles with thiol groups in the patches were obtained. Dynamic light scattering, transmission electron microscopy, and zeta-potential measurements demonstrate the preparation of patchy micelles. Gold nanoparticles can be anchored onto the patchy micelles through S-Au bonds, and asymmetric hybrid structures are formed. The thiol groups can be oxidized to disulfides, which results in directional assembly of the patchy micelles. The self-assembly behavior of the patchy micelles was studied experimentally and by computer simulation.

  16. Blocking effect and numerical study of polymer particles dispersion flooding in heterogeneous reservoir

    Science.gov (United States)

    Zhu, Weiyao; Li, Jianhui; Lou, Yu

    2018-02-01

    Polymer flooding has become an effective way to improve the sweep efficiency in many oil fields. Many scholars have carried out a lot of researches on the mechanism of polymer flooding. In this paper, the effect of polymer on seepage is analyzed. The blocking effect of polymer particles was studied experimentally, and the residual resistance coefficient (RRF) were used to represent the blocking effect. We also build a mathematical model for heterogeneous concentration distribution of polymer particles. Furthermore, the effects of polymer particles on reservoir permeability, fluid viscosity and relative permeability are considered, and a two-phase flow model of oil and polymer particles is established. In addition, the model was tested in the heterogeneous stratum model, and three influencing factors, such as particle concentration, injection volume and PPD (short for polymer particle dispersion) injection time, were analyzed. Simulation results show that PPD can effectively improve sweep efficiency and especially improve oil recovery of low permeability layer. Oil recovery increases with the increase of particle concentration, but oil recovery increase rate gradually decreases with that. The greater the injected amount of PPD, the greater oil recovery and the smaller oil recovery increase rate. And there is an optimal timing to inject PPD for specific reservoir.

  17. On the Eigenvalues and Eigenvectors of Block Triangular Preconditioned Block Matrices

    KAUST Repository

    Pestana, Jennifer

    2014-01-01

    Block lower triangular matrices and block upper triangular matrices are popular preconditioners for 2×2 block matrices. In this note we show that a block lower triangular preconditioner gives the same spectrum as a block upper triangular preconditioner and that the eigenvectors of the two preconditioned matrices are related. © 2014 Society for Industrial and Applied Mathematics.

  18. The fabrication of highly ordered block copolymer micellar arrays: control of the separation distances of silicon oxide dots

    Science.gov (United States)

    Yoo, Hana; Park, Soojin

    2010-06-01

    We demonstrate the fabrication of highly ordered silicon oxide dotted arrays prepared from polydimethylsiloxane (PDMS) filled nanoporous block copolymer (BCP) films and the preparation of nanoporous, flexible Teflon or polyimide films. Polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) films were annealed in toluene vapor to enhance the lateral order of micellar arrays and were subsequently immersed in alcohol to produce nano-sized pores, which can be used as templates for filling a thin layer of PDMS. When a thin layer of PDMS was spin-coated onto nanoporous BCP films and thermally annealed at a certain temperature, the PDMS was drawn into the pores by capillary action. PDMS filled BCP templates were exposed to oxygen plasma environments in order to fabricate silicon oxide dotted arrays. By addition of PS homopolymer to PS-b-P2VP copolymer, the separation distances of micellar arrays were tuned. As-prepared silicon oxide dotted arrays were used as a hard master for fabricating nanoporous Teflon or polyimide films by spin-coating polymer precursor solutions onto silicon patterns and peeling off. This simple process enables us to fabricate highly ordered nanoporous BCP templates, silicon oxide dots, and flexible nanoporous polymer patterns with feature size of sub-20 nm over 5 cm × 5 cm.

  19. The fabrication of highly ordered block copolymer micellar arrays: control of the separation distances of silicon oxide dots

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hana; Park, Soojin, E-mail: spark@unist.ac.kr [Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology, Banyeon-ri 100, Ulsan 689-798 (Korea, Republic of)

    2010-06-18

    We demonstrate the fabrication of highly ordered silicon oxide dotted arrays prepared from polydimethylsiloxane (PDMS) filled nanoporous block copolymer (BCP) films and the preparation of nanoporous, flexible Teflon or polyimide films. Polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) films were annealed in toluene vapor to enhance the lateral order of micellar arrays and were subsequently immersed in alcohol to produce nano-sized pores, which can be used as templates for filling a thin layer of PDMS. When a thin layer of PDMS was spin-coated onto nanoporous BCP films and thermally annealed at a certain temperature, the PDMS was drawn into the pores by capillary action. PDMS filled BCP templates were exposed to oxygen plasma environments in order to fabricate silicon oxide dotted arrays. By addition of PS homopolymer to PS-b-P2VP copolymer, the separation distances of micellar arrays were tuned. As-prepared silicon oxide dotted arrays were used as a hard master for fabricating nanoporous Teflon or polyimide films by spin-coating polymer precursor solutions onto silicon patterns and peeling off. This simple process enables us to fabricate highly ordered nanoporous BCP templates, silicon oxide dots, and flexible nanoporous polymer patterns with feature size of sub-20 nm over 5 cm x 5 cm.

  20. Membrane fouling mechanism of biofilm-membrane bioreactor (BF-MBR): Pore blocking model and membrane cleaning.

    Science.gov (United States)

    Zheng, Yi; Zhang, Wenxiang; Tang, Bing; Ding, Jie; Zheng, Yi; Zhang, Zhien

    2018-02-01

    Biofilm membrane bioreactor (BF-MBR) is considered as an important wastewater treatment technology that incorporates advantages of both biofilm and MBR process, as well as can alleviate membrane fouling, with respect to the conventional activated sludge MBR. But, to be efficient, it necessitates the establishment of proper methods for the assessment of membrane fouling. Four Hermia membrane blocking models were adopted to quantify and evaluate the membrane fouling of BF-MBR. The experiments were conducted with various operational conditions, including membrane types, agitation speeds and transmembrane pressure (TMP). Good agreement between cake formation model and experimental data was found, confirming the validity of the Hermia models for assessing the membrane fouling of BF-MBR and that cake layer deposits on membrane. Moreover, the influences of membrane types, agitation speeds and transmembrane pressure on the Hermia pore blocking coefficient of cake layer were investigated. In addition, the permeability recovery after membrane cleaning at various operational conditions was studied. This work confirms that, unlike conventional activated sludge MBR, BF-MBR possesses a low degree of membrane fouling and a higher membrane permeability recovery after cleaning. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Ultrathin, Ultrasmooth Gold Layer on Dielectrics without the Use of Additional Metallic Adhesion Layers

    DEFF Research Database (Denmark)

    Leandro, Lorenzo; Malureanu, Radu; Rozlosnik, Noemi

    2015-01-01

    With advances in the plasmonics and metamaterials research field, it has become more and more important to fabricate thin and smooth Au metal films in a reliable way. Here, by thin films we mean that their average height is below 10 mu and their average roughness is below 5% of the total thicknes...

  2. High strain rate deformation of layered nanocomposites.

    Science.gov (United States)

    Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A; Thomas, Edwin L

    2012-01-01

    Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10 nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

  3. High strain rate deformation of layered nanocomposites

    Science.gov (United States)

    Lee, Jae-Hwang; Veysset, David; Singer, Jonathan P.; Retsch, Markus; Saini, Gagan; Pezeril, Thomas; Nelson, Keith A.; Thomas, Edwin L.

    2012-11-01

    Insight into the mechanical behaviour of nanomaterials under the extreme condition of very high deformation rates and to very large strains is needed to provide improved understanding for the development of new protective materials. Applications include protection against bullets for body armour, micrometeorites for satellites, and high-speed particle impact for jet engine turbine blades. Here we use a microscopic ballistic test to report the responses of periodic glassy-rubbery layered block-copolymer nanostructures to impact from hypervelocity micron-sized silica spheres. Entire deformation fields are experimentally visualized at an exceptionally high resolution (below 10 nm) and we discover how the microstructure dissipates the impact energy via layer kinking, layer compression, extreme chain conformational flattening, domain fragmentation and segmental mixing to form a liquid phase. Orientation-dependent experiments show that the dissipation can be enhanced by 30% by proper orientation of the layers.

  4. Emplacement of small and large buffer blocks

    International Nuclear Information System (INIS)

    Saari, H.; Nikula, M.; Suikki, M.

    2010-05-01

    The report describes emplacement of a buffer structure encircling a spent fuel canister to be deposited in a vertical hole. The report deals with installability of various size blocks and with an emplacement gear, as well as evaluates the achieved quality of emplacement and the time needed for installing the buffer. Two block assembly of unequal size were chosen for examination. A first option involved small blocks, the use of which resulted in a buffer structure consisting of small sector blocks 200 mm in height. A second option involved large blocks, resulting in a buffer structure which consists of eight blocks. In these tests, the material chosen for both block options was concrete instead of bentonite. The emplacement test was a three-phase process. A first phase included stacking a two meter high buffer structure with small blocks for ensuring the operation of test equipment and blocks. A second phase included installing buffer structures with both block options to a height matching that of a canister-encircling cylindrical component. A third phase included testing also the installability of blocks to be placed above the canister by using small blocks. In emplacement tests, special attention was paid to the installability of blocks as well as to the time required for emplacement. Lifters for both blocks worked well. Due to the mass to be lifted, the lifter for large blocks had a more heavy-duty frame structure (and other lifting gear). The employed lifters were suspended in the tests on a single steel wire rope. Stacking was managed with both block sizes at adequate precision and stacked-up towers were steady. The stacking of large blocks was considerably faster. Therefore it is probably that the overall handling of the large blocks will be more convenient at a final disposal site. From the standpoint of reliability in lifting, the small blocks were safer to install above the canister. In large blocks, there are strict shape-related requirements which are

  5. A Bullet-Block Experiment that Explains the Chain Fountain

    Science.gov (United States)

    Pantaleone, J.; Smith, R.

    2018-05-01

    It is common in science for two phenomena to appear to be very different, but in fact follow from the same basic principles. Here we consider such a case, the connection between the chain fountain and a bullet-block collision experiment. When an upward moving bullet strikes a wooden block resting on a horizontal table, the block will rise to a higher height when the bullet strikes near the end of the block. This is because the quickly rotating block experiences an additional upward "reaction" force from its contact with the table. Such a reaction force also explains the chain fountain. When a chain falls from a pile in a container to the floor below, the chain rises up above the container. This rise occurs because the quickly rotating links in the container push off of the surface beneath them. We derive a model that accurately describes our measurements in the bullet-block experiment, and then use this same model to calculate an approximate expression for the distance the chain rises above the container. More extensive discussions of the chain fountain are available elsewhere.

  6. A basic review on the inferior alveolar nerve block techniques.

    Science.gov (United States)

    Khalil, Hesham

    2014-01-01

    The inferior alveolar nerve block is the most common injection technique used in dentistry and many modifications of the conventional nerve block have been recently described in the literature. Selecting the best technique by the dentist or surgeon depends on many factors including the success rate and complications related to the selected technique. Dentists should be aware of the available current modifications of the inferior alveolar nerve block techniques in order to effectively choose between these modifications. Some operators may encounter difficulty in identifying the anatomical landmarks which are useful in applying the inferior alveolar nerve block and rely instead on assumptions as to where the needle should be positioned. Such assumptions can lead to failure and the failure rate of inferior alveolar nerve block has been reported to be 20-25% which is considered very high. In this basic review, the anatomical details of the inferior alveolar nerve will be given together with a description of its both conventional and modified blocking techniques; in addition, an overview of the complications which may result from the application of this important technique will be mentioned.

  7. Comparison of three cell block techniques for detection of low frequency abnormal cells

    OpenAIRE

    McCormack M; Hecht SA

    2013-01-01

    Steven A Hecht, Matthew McCormackHologic Inc, Marlborough, MA, USABackground: The Cellient® Automated Cell Block System rapidly creates paraffin-embedded cell blocks by using vacuum filtration to deposit a layer of cells on a filter and infiltrate those cells with reagents and paraffin. This study used a “tracer” cell model to mimic low frequency abnormal cells and compare detection and representative sampling with simple sedimentation, Richard-Allan HistoGel&t...

  8. UAV PHOTOGRAMMETRY: BLOCK TRIANGULATION COMPARISONS

    Directory of Open Access Journals (Sweden)

    R. Gini

    2013-08-01

    Full Text Available UAVs systems represent a flexible technology able to collect a big amount of high resolution information, both for metric and interpretation uses. In the frame of experimental tests carried out at Dept. ICA of Politecnico di Milano to validate vector-sensor systems and to assess metric accuracies of images acquired by UAVs, a block of photos taken by a fixed wing system is triangulated with several software. The test field is a rural area included in an Italian Park ("Parco Adda Nord", useful to study flight and imagery performances on buildings, roads, cultivated and uncultivated vegetation. The UAV SenseFly, equipped with a camera Canon Ixus 220HS, flew autonomously over the area at a height of 130 m yielding a block of 49 images divided in 5 strips. Sixteen pre-signalized Ground Control Points, surveyed in the area through GPS (NRTK survey, allowed the referencing of the block and accuracy analyses. Approximate values for exterior orientation parameters (positions and attitudes were recorded by the flight control system. The block was processed with several software: Erdas-LPS, EyeDEA (Univ. of Parma, Agisoft Photoscan, Pix4UAV, in assisted or automatic way. Results comparisons are given in terms of differences among digital surface models, differences in orientation parameters and accuracies, when available. Moreover, image and ground point coordinates obtained by the various software were independently used as initial values in a comparative adjustment made by scientific in-house software, which can apply constraints to evaluate the effectiveness of different methods of point extraction and accuracies on ground check points.

  9. Small homologous blocks in phytophthora genomes do not point to an ancient whole-genome duplication.

    Science.gov (United States)

    van Hooff, Jolien J E; Snel, Berend; Seidl, Michael F

    2014-05-01

    Genomes of the plant-pathogenic genus Phytophthora are characterized by small duplicated blocks consisting of two consecutive genes (2HOM blocks) and by an elevated abundance of similarly aged gene duplicates. Both properties, in particular the presence of 2HOM blocks, have been attributed to a whole-genome duplication (WGD) at the last common ancestor of Phytophthora. However, large intraspecies synteny-compelling evidence for a WGD-has not been detected. Here, we revisited the WGD hypothesis by deducing the age of 2HOM blocks. Two independent timing methods reveal that the majority of 2HOM blocks arose after divergence of the Phytophthora lineages. In addition, a large proportion of the 2HOM block copies colocalize on the same scaffold. Therefore, the presence of 2HOM blocks does not support a WGD at the last common ancestor of Phytophthora. Thus, genome evolution of Phytophthora is likely driven by alternative mechanisms, such as bursts of transposon activity.

  10. Tunneling of the blocked wave in a circular hydraulic jump

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, Jayanta K., E-mail: jkb@hri.res.in

    2017-02-19

    The formation of a circular hydraulic jump in a thin liquid layer involves the creation of a horizon where the incoming wave (surface ripples) is blocked by the fast flowing fluid. That there is a jump at the horizon is due to the viscosity of the fluid which is not relevant for the horizon formation. By using a tunneling formalism developed for the study of the Hawking radiation from black holes, we explicitly show that there will be an exponentially small tunneling of the blocked wave across the horizons as anticipated in studies of “analog gravity”. - Highlights: • A thin layer of radially flowing fluid traveling at high speed sweeps away the incoming ripples. • The speed decreases as the flow spreads out. • At some radius the flow speed decreases to match the ripple speed creating a “horizon”. • The “horizon” blocks out the incoming ripples mimicking a white hole horizon. • The fluctuations around the steady state allows an exponentially small penetration inside the horizon analogous to the Hawking effect.

  11. [THE TECHNOLOGY "CELL BLOCK" IN CYTOLOGICAL PRACTICE].

    Science.gov (United States)

    Volchenko, N N; Borisova, O V; Baranova, I B

    2015-08-01

    The article presents summary information concerning application of "cell block" technology in cytological practice. The possibilities of implementation of various modern techniques (immune cytochemnical analysis. FISH, CISH, polymerase chain reaction) with application of "cell block" method are demonstrated. The original results of study of "cell block" technology made with gelatin, AgarCyto and Shadon Cyoblock set are presented. The diagnostic effectiveness of "cell block" technology and common cytological smear and also immune cytochemical analysis on samples of "cell block" technology and fluid cytology were compared. Actually application of "cell block" technology is necessary for ensuring preservation of cell elements for subsequent immune cytochemical and molecular genetic analysis.

  12. Minimum description length block finder, a method to identify haplotype blocks and to compare the strength of block boundaries.

    Science.gov (United States)

    Mannila, H; Koivisto, M; Perola, M; Varilo, T; Hennah, W; Ekelund, J; Lukk, M; Peltonen, L; Ukkonen, E

    2003-07-01

    We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the significance of each block boundary. We have applied the method to the published data of Daly and colleagues. The results expose some problems that exist in the current methods for the evaluation of the significance of predicted block boundaries. Our method, MDL block finder, can be used to compare block borders in different sample sets, and we demonstrate this by applying the MDL-based method to define the block structure in chromosomes from population isolates.

  13. Adductor canal block versus femoral nerve block for analgesia after total knee arthroplasty

    DEFF Research Database (Denmark)

    Jaeger, Pia; Zaric, Dusanka; Fomsgaard, Jonna Storm

    2013-01-01

    Femoral nerve block (FNB), a commonly used postoperative pain treatment after total knee arthroplasty (TKA), reduces quadriceps muscle strength essential for mobilization. In contrast, adductor canal block (ACB) is predominately a sensory nerve block. We hypothesized that ACB preserves quadriceps...

  14. Liposomal bupivacaine peripheral nerve block for the management of postoperative pain.

    Science.gov (United States)

    Hamilton, Thomas W; Athanassoglou, Vassilis; Trivella, Marialena; Strickland, Louise H; Mellon, Stephen; Murray, David; Pandit, Hemant G

    2016-08-25

    Postoperative pain remains a significant issue with poor perioperative pain management associated with an increased risk of morbidity and mortality. Liposomal bupivacaine is an analgesic consisting of bupivacaine hydrochloride encapsulated within multiple, non-concentric lipid bi-layers offering a novel method of sustained release. To assess the analgesic efficacy and adverse effects of liposomal bupivacaine infiltration peripheral nerve block for the management of postoperative pain. We identified randomised trials of liposomal bupivacaine peripheral nerve block for the management of postoperative pain. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 1), Ovid MEDLINE (1946 to January Week 1 2016), Ovid MEDLINE In-Process (14 January 2016), EMBASE (1974 to 13 January 2016), ISI Web of Science (1945 to 14 January 2016), and reference lists of retrieved articles. We sought unpublished studies from Internet sources, and searched clinical trials databases for ongoing trials. The date of the most recent search was 15 January 2016. Randomised, double-blind, placebo- or active-controlled clinical trials of a single dose of liposomal bupivacaine administered as a peripheral nerve block in adults aged 18 years or over undergoing elective surgery at any surgical site. We included trials if they had at least two comparison groups for liposomal bupivacaine peripheral nerve block compared with placebo or other types of analgesia. Two review authors independently considered trials for inclusion in the review, assessed risk of bias, and extracted data. We performed analyses using standard statistical techniques as described in the Cochrane Handbook for Systematic Reviews of Interventions, using Review Manager 5. We planned to perform a meta-analysis, however there were insufficient data to ensure a clinically meaningful answer; as such we have produced a 'Summary of findings' table in a narrative format, and where possible we assessed the

  15. The Frontiers of Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-03

    Additive manufacturing, more commonly known as 3-D printing, has become a ubiquitous tool in science for its precise control over mechanical design. For additive manufacturing to work, a 3-D structure is split into thin 2D slices, and then different physical properties, such as photo-polymerization or melting, are used to grow the sequential layers. The level of control allows not only for devices to be made with a variety of materials: e.g. plastics, metals, and quantum dots, but to also have finely controlled structures leading to other novel properties. While 3-D printing is widely used by hobbyists for making models, it also has industrial applications in structural engineering, biological tissue scaffolding, customized electric circuitry, fuel cells, security, and more.

  16. Mechanical properties of millet husk ash bitumen stabilized soil block

    African Journals Online (AJOL)

    This study presents an investigation into the improvement of strength and durability properties of lateritic soil blocks using Millet Husk Ash (MHA) and Bitumen as additives so as to reduce its high cost and find alternative disposal method for agricultural waste. The lateritic soil samples were selected and treated with 0%, ...

  17. Calculation of power spectra for block coded signals

    DEFF Research Database (Denmark)

    Justesen, Jørn

    2001-01-01

    We present some improvements in the procedure for calculating power spectra of signals based on finite state descriptions and constant block size. In addition to simplified calculations, our results provide some insight into the form of the closed expressions and to the relation between the spect...

  18. Additive Manufacturing of Shape Memory Alloys

    Science.gov (United States)

    Van Humbeeck, Jan

    2018-04-01

    Selective Laser Melting (SLM) is an additive manufacturing production process, also called 3D printing, in which functional, complex parts are produced by selectively melting patterns in consecutive layers of powder with a laser beam. The pattern the laser beam is following is controlled by software that calculates the pattern by slicing a 3D CAD model of the part to be constructed. Apart from SLM, also other additive manufacturing techniques such as EBM (Electron Beam Melting), FDM (Fused Deposition Modelling), WAAM (Wire Arc Additive Manufacturing), LENS (Laser Engineered Net Shaping such as Laser Cladding) and binder jetting allow to construct complete parts layer upon layer. But since more experience of AM of shape memory alloys is collected by SLM, this paper will overview the potentials, limits and problems of producing NiTi parts by SLM.

  19. Structural Study and Modification of Support Layer for Forward Osmosis Membranes

    KAUST Repository

    Shi, Meixia

    2016-06-01

    Water scarcity is a serious global issue, due to the increasing population and developing economy, and membrane technology is an essential way to address this problem. Forward osmosis (FO) is an emerging membrane process, due to its low energy consumption (not considering the draw solute regeneration). A bottleneck to advance this technology is the design of the support layer for FO membranes to minimize the internal concentration polarization. In this dissertation, we focus on the structural study and modification of the support layer for FO membranes. Firstly, we digitally reconstruct different membrane morphologies in 3D and propose a method for predicting performance in ultrafiltration operations. Membranes with analogous morphologies are later used as substrate for FO membranes. Secondly, we experimentally apply substrates with different potentially suitable morphologies as an FO support layer. We investigate their FO performance after generating a selective polyamide layer on the top, by interfacial polymerization. Among the different substrates we include standard asymmetric porous membranes prepared from homopolymers, such as polysulfone. Additionally block copolymer membrane and Anodisc alumina membrane are chosen based on their exceptional structures, with cylindrical pores at least in part. 3D digitally reconstructed porous substrates, analogous to those investigated for ultrafiltration, are then used to model the performance in FO operation. Finally, we analyze the effect of intermediate layers between the porous substrate and the interfacial polymerized layer. We investigate two materials including chitosan and hydrogel. The main results are the following. Pore-scale modeling for digital membrane generation effectively predicts the velocity profile in different layers of the membrane and the performance in UF experiments. Flow simulations confirm the advantage of finger-like substrates over sponge-like ones, when high water permeance is sought

  20. Study of matrix micro-cracking in nano clay and acrylic tri-block-copolymer modified epoxy/basalt fiber-reinforced pressure-retaining structures

    Directory of Open Access Journals (Sweden)

    2011-10-01

    Full Text Available In fiber-reinforced polymer pressure-retaining structures, such as pipes and vessels, micro-level failure commonly causes fluid permeation due to matrix cracking. This study explores the effect of nano-reinforcements on matrix cracking in filament-wound basalt fiber/epoxy composite structures. The microstructure and mechanical properties of bulk epoxy nanocomposites and hybrid fiber-reinforced composite pipes modified with acrylic tri-block-copolymer and organophilic layered silicate clay were investigated. In cured epoxy, the tri-block-copolymer phase separated into disordered spherical micelle inclusions; an exfoliated and intercalated structure was observed for the nano-clay. Block-copolymer addition significantly enhanced epoxy fracture toughness by a mechanism of particle cavitation and matrix shear yielding, whereas toughness remained unchanged in nano-clay filled nanocomposites due to the occurrence of lower energy resistance phenomena such as crack deflection and branching.Tensile stiffness increased with nano-clay content, while it decreased slightly for block-copolymer modified epoxy. Composite pipes modified with either the organic and inorganic nanoparticles exhibited moderate improvements in leakage failure strain (i.e. matrix cracking strain; however, reductions in functional and structural failure strength were observed.

  1. Study on Surface Modification of Glass Bead by a Block Copolymer Coupling Agent

    Institute of Scientific and Technical Information of China (English)

    LI Yin; ZHANG Bing; ZHOU Xiao-dong

    2008-01-01

    A tri-block copolymer coupling agent polystyrene biock-poly(n-butyl-acrylate)-block-poly(r-methacryloxypro pylt rimethoxysilane)(PS-b-PnBA-b-PMPS)was synthesized by atom transfer radical polymerization(ATRP),and its molecular structure was characterized by fourier-transform infrared spectra,hydrogen nuclear magnetic resonance and gel permeation chromatography.The glass bead was treated with the block copolymer coupling agent,and then studied by transmission electron microscopy.The result showed that strong interaction was formed between the block copolymer coupling agent and the surface of glass bead,and then the block of poly(n-butylacrylate)formed a layer of film on the surface.

  2. Fibrinogen adsorption on blocked surface of albumin.

    Science.gov (United States)

    Holmberg, Maria; Hou, Xiaolin

    2011-05-01

    We have investigated the adsorption of albumin and fibrinogen onto PET (polyethylene terephthalate) and glass surfaces and how pre-adsorption of albumin onto these surfaces can affect the adsorption of later added fibrinogen. For materials and devices being exposed to blood, adsorption of fibrinogen is often a non-wanted event, since fibrinogen is part of the clotting cascade and unspecific adsorption of fibrinogen can have an influence on the activation of platelets. Albumin is often used as blocking agent for avoiding unspecific protein adsorption onto surfaces in devices designed to handle biological samples, including protein solutions. It is based on the assumption that proteins adsorbs as a monolayer on surfaces and that proteins do not adsorb on top of each other. By labelling albumin and fibrinogen with two different radioactive iodine isotopes that emit gamma radiation with different energies, the adsorption of both albumin and fibrinogen has been monitored simultaneously on the same sample. Information about topography and coverage of adsorbed protein layers has been obtained using AFM (Atomic Force Microscopy) analysis in liquid. Our studies show that albumin adsorbs in a multilayer fashion on PET and that fibrinogen adsorbs on top of albumin when albumin is pre-adsorbed on the surfaces. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. Blocking device especially for circulating pumps

    International Nuclear Information System (INIS)

    Susil, J.; Vychodil, V.; Lorenc, P.

    1976-01-01

    The claim of the invention is a blocking device which blocks reverse flow occurring after the shutdown of circulating pumps, namely in the operation of nuclear power plants or in pumps with a high delivery head. (F.M.)

  4. Thoracic paravertebral block versus transversus abdominis plane block in major gynecological surgery: a prospective, randomized, controlled, observer-blinded study

    Directory of Open Access Journals (Sweden)

    Melnikov AL

    2012-10-01

    Full Text Available Andrey L Melnikov,1 Steinar Bjoergo,1 Ulf E Kongsgaard21Department of Anesthesiology, Division of Emergencies and Critical Care, Oslo University Hospital, Oslo, Norway; 2Department of Research and Development, Division of Emergencies and Critical Care, Oslo University Hospital and Medical Faculty, University of Oslo, Oslo, NorwayBackground and objectives: Patients undergoing abdominal surgery often receive an epidural infusion for postoperative analgesia. However, when epidural analgesia is contraindicated or unwanted, the administration of opioids is the usual means used to relieve pain. Various regional analgesia techniques used in conjunction with systemic analgesia have been reported to reduce the cumulative postoperative opioid consumption and opioid-induced side effects. The objective of this trial was to assess the effectiveness of transversus abdominis plane block and paravertebral block in women undergoing major gynecological surgery.Methods: We analyzed 58 patients scheduled for a midline vertical laparatomy due to gynecological cancer. They were all equipped with a patient-controlled postoperative analgesia pump that delivered ketobemidon. In addition, some patients were randomized to receive either a bilateral transversus abdominis plane block (n = 19 or a bilateral paravertebral block at the level of Th10 (n = 19. Both blocks were performed preoperatively as a single injection of bupivacaine.Results: Cumulative ketobemidon consumption, postoperative pain scores at rest and while coughing, and postoperative nausea and vomiting scores were assessed by a blinded observer at 2, 4, 6, 24, and 48 hours postoperatively. Both blocks were associated with significant reductions in opioid consumption and pain scores throughout the study period compared with the control patients. Postoperative nausea and vomiting scores were low in all groups, but during the early postoperative period more control group patients needed antiemetics

  5. Reversible chronic acquired complete atrioventricular block.

    Science.gov (United States)

    Rakovec, P; Milcinski, G; Voga, G; Korsic, L

    1982-01-01

    The return of atrioventricular conduction is reported in a case after nearly four years of complete acquired heart block. After recovery from atrioventricular block, right bundle branch block persisted, but P-R interval and H-V interval were normal. Three months later a relapse of second degree infranodal atrioventricular block was noted. A short review of similar cases from the literature is given.

  6. Manipulating Interfaces through Surface Confinement of Poly(glycidyl methacrylate)-block-poly(vinyldimethylazlactone), a Dually Reactive Block Copolymer

    International Nuclear Information System (INIS)

    Lokitz, Bradley S.; Wei, Jifeng; Hinestrosa Salazar, Juan P.; Ivanov, Ilia N.; Browning, James B.; Ankner, John Francis; Kilbey, S. Michael II; Messman, Jamie M.

    2012-01-01

    The assembly of dually reactive, well-defined diblock copolymers incorporating the chemoselective/functional monomer, 4,4-dimethyl-2-vinylazlactone (VDMA) and the surface-reactive monomer glycidyl methacrylate (GMA) is examined to understand how competition between surface attachment and microphase segregation influences interfacial structure. Reaction of the PGMA block with surface hydroxyl groups not only anchors the copolymer to the surface, but limits chain mobility, creating brush-like structures comprising PVDMA blocks, which contain reactive azlactone groups. The block copolymers are spin coated at various solution concentrations and annealed at elevated temperature to optimize film deposition to achieve a molecularly uniform layer. The thickness and structure of the polymer thin films are investigated by ellipsometry, infrared spectroscopy, and neutron reflectometry. The results show that deposition of PGMA-b-PVDMA provides a useful route to control film thickness while preserving azlactone groups that can be further modified with biotin-poly(ethylene glycol)amine to generate designer surfaces. The method described herein offers guidance for creating highly functional surfaces, films, or coatings through the use of dually reactive block copolymers and postpolymerization modification.

  7. Block 3 X-band receiver-exciter

    Science.gov (United States)

    Johns, C. E.

    1987-01-01

    The development of an X-band exciter, for use in the X-Band Uplink Subsystem, was completed. The exciter generates the drive signal for the X-band transmitter and also generates coherent test signals for the S- and X-band Block 3 translator and a Doppler reference signal for the Doppler extractor system. In addition to the above, the exciter generates other reference signals that are described. Also presented is an overview of the exciter design and some test data taken on the prototype. A brief discussion of the Block 3 Doppler extractor is presented.

  8. MARINE BOTTOM COMMUNITIES OF BLOCK ISLAND WATERS

    Science.gov (United States)

    The sea has long been an integral part of Block Island's natural history, beginning when the rising sea surrounded the high spot on a Pleistocene terminal moraine that became Block Island. The southern New England continental shelf, which lies around Block Island, and the Great S...

  9. Encoders for block-circulant LDPC codes

    Science.gov (United States)

    Divsalar, Dariush (Inventor); Abbasfar, Aliazam (Inventor); Jones, Christopher R. (Inventor); Dolinar, Samuel J. (Inventor); Thorpe, Jeremy C. (Inventor); Andrews, Kenneth S. (Inventor); Yao, Kung (Inventor)

    2009-01-01

    Methods and apparatus to encode message input symbols in accordance with an accumulate-repeat-accumulate code with repetition three or four are disclosed. Block circulant matrices are used. A first method and apparatus make use of the block-circulant structure of the parity check matrix. A second method and apparatus use block-circulant generator matrices.

  10. 49 CFR 236.708 - Block.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Block. 236.708 Section 236.708 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.708 Block. A length of track of defined limits, the use of which by trains is governed by block signals, cab signals, or both. ...

  11. 49 CFR 236.804 - Signal, block.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Signal, block. 236.804 Section 236.804 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Signal, block. A roadway signal operated either automatically or manually at the entrance to a block. ...

  12. Block Play: Practical Suggestions for Common Dilemmas

    Science.gov (United States)

    Tunks, Karyn Wellhousen

    2009-01-01

    Learning materials and teaching methods used in early childhood classrooms have fluctuated greatly over the past century. However, one learning tool has stood the test of time: Wood building blocks, often called unit blocks, continue to be a source of pleasure and learning for young children at play. Wood blocks have the unique capacity to engage…

  13. Naming Block Structures: A Multimodal Approach

    Science.gov (United States)

    Cohen, Lynn; Uhry, Joanna

    2011-01-01

    This study describes symbolic representation in block play in a culturally diverse suburban preschool classroom. Block play is "multimodal" and can allow children to experiment with materials to represent the world in many forms of literacy. Combined qualitative and quantitative data from seventy-seven block structures were collected and analyzed.…

  14. 21 CFR 882.5070 - Bite block.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bite block. 882.5070 Section 882.5070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5070 Bite block. (a) Identification. A bite block...

  15. Large block test status report

    International Nuclear Information System (INIS)

    Wilder, D.G.; Lin, W.; Blair, S.C.

    1997-01-01

    This report is intended to serve as a status report, which essentially transmits the data that have been collected to date on the Large Block Test (LBT). The analyses of data will be performed during FY98, and then a complete report will be prepared. This status report includes introductory material that is not needed merely to transmit data but is available at this time and therefore included. As such, this status report will serve as the template for the future report, and the information is thus preserved

  16. Block-conjugate-gradient method

    International Nuclear Information System (INIS)

    McCarthy, J.F.

    1989-01-01

    It is shown that by using the block-conjugate-gradient method several, say s, columns of the inverse Kogut-Susskind fermion matrix can be found simultaneously, in less time than it would take to run the standard conjugate-gradient algorithm s times. The method improves in efficiency relative to the standard conjugate-gradient algorithm as the fermion mass is decreased and as the value of the coupling is pushed to its limit before the finite-size effects become important. Thus it is potentially useful for measuring propagators in large lattice-gauge-theory calculations of the particle spectrum

  17. Model Research On Synthesis Of Al2O3-C Layers By MOCVD

    Directory of Open Access Journals (Sweden)

    Sawka A.

    2015-06-01

    Full Text Available These are model studies whose aim is to obtain information that would allow development of new technology for synthesizing monolayers of Al2O3-C with adjusted microstructure on cemented carbides. The Al2O3-C layer will constitute an intermediate layer on which the outer layer of Al2O3 without carbon is synthesized. The purpose of the intermediate layer is to block the cobalt diffusion to the synthesized outer layer of Al2O3 and to stop the diffusion of air oxygen to the substrate during the synthesis of the outer layer. This layer should be thin, continuous, dense and uniform in thickness.

  18. Magnetic Reversal and Thermal Stability of CoFeB Perpendicular Magnetic Tunnel Junction Arrays Patterned by Block Copolymer Lithography

    KAUST Repository

    Tu, Kun-Hua; Fernandez Martin, Eduardo; almasi, hamid; Wang, Weigang; Navas Otero, David; Ntetsikas, Konstantinos; Moschovas, Dimitrios; Avgeropoulos, Apostolos; Ross, Caroline A

    2018-01-01

    Dense arrays of pillars, with diameters of 64 and 25 nm, were made from a perpendicular CoFeB magnetic tunnel junction thin film stack using block copolymer lithography. While the soft layer and hard layer in the 64 nm pillars reverse at different

  19. Absence of Rapid Propagation through the Purkinje Network as a Potential Cause of Line Block in the Human Heart with Left Bundle Branch Block.

    Science.gov (United States)

    Okada, Jun-Ichi; Washio, Takumi; Nakagawa, Machiko; Watanabe, Masahiro; Kadooka, Yoshimasa; Kariya, Taro; Yamashita, Hiroshi; Yamada, Yoko; Momomura, Shin-Ichi; Nagai, Ryozo; Hisada, Toshiaki; Sugiura, Seiryo

    2018-01-01

    Background: Cardiac resynchronization therapy is an effective device therapy for heart failure patients with conduction block. However, a problem with this invasive technique is the nearly 30% of non-responders. A number of studies have reported a functional line of block of cardiac excitation propagation in responders. However, this can only be detected using non-contact endocardial mapping. Further, although the line of block is considered a sign of responders to therapy, the mechanism remains unclear. Methods: Herein, we created two patient-specific heart models with conduction block and simulated the propagation of excitation based on a cellmodel of electrophysiology. In one model with a relatively narrow QRS width (176 ms), we modeled the Purkinje network using a thin endocardial layer with rapid conduction. To reproduce a wider QRS complex (200 ms) in the second model, we eliminated the Purkinje network, and we simulated the endocardial mapping by solving the inverse problem according to the actual mapping system. Results: We successfully observed the line of block using non-contact mapping in the model without the rapid propagation of excitation through the Purkinje network, although the excitation in the wall propagated smoothly. This model of slow conduction also reproduced the characteristic properties of the line of block, including dense isochronal lines and fractionated local electrocardiograms. Further, simulation of ventricular pacing from the lateral wall shifted the location of the line of block. By contrast, in the model with the Purkinje network, propagation of excitation in the endocardial map faithfully followed the actual propagation in the wall, without showing the line of block. Finally, switching the mode of propagation between the two models completely reversed these findings. Conclusions: Our simulation data suggest that the absence of rapid propagation of excitation through the Purkinje network is the major cause of the functional line

  20. Study on the relationship of the fault-block structure feature and sandstone uranium formation in Chaoshui basin north belt

    International Nuclear Information System (INIS)

    Liu Lin

    2006-12-01

    The mineralization conditions for three types of acclivity belt (Baojia Jing A' Lashan Youqi-Tangjia Gou and Taojia Jing CHAOSHUI BASIN NORTH BELT) are analyzed, according to the fault-block acclivity belt, the prospecting goal layer, the interlayer oxidized zone and uranium metallization characteristic and so on. It is considered that the positive fault-block acclivity belt favors containing oxygen and uranium water coming from eclipse source area to go into prospecting goal layer, and advanced the formation of interlayer oxidized zone and sandstone uranium metallization. The antithetic fault-block and the buried fault-block acclivity don't favors containing oxygen and uranium water into prospecting goal layer, and format difficultly interlayer oxidized belt and sandstone uranium metallization. Therefore A'Lashan Youqi-Tangjia Gou part is a uranium mineralization prospect sector. (authors)

  1. Additive manufacturing of RF absorbers

    Science.gov (United States)

    Mills, Matthew S.

    The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

  2. Additive Manufacturing Infrared Inspection

    Science.gov (United States)

    Gaddy, Darrell; Nettles, Mindy

    2015-01-01

    The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.

  3. Mesure de la capacité différencielle de la double couche électrique en milieu hydrocarbure. Etude de l'interface métal-additifs pour lubrifiants. Première partie Measuring the Differential Capacity of the Electric Double Layer in a Hydrocarbon Medium. Analysis of the Metal Additive Interface for Lubricants. Part One

    Directory of Open Access Journals (Sweden)

    Hipeaux J. C.

    2006-11-01

    Full Text Available Le phénomène d'adsorption d'additifs détergents-dispersants contenus dans les huiles lubrifiantes est à la base de l'action de ces produits. L'existence d'une double couche électrique est un des paramètres envisagés lors de l'étude de l'interface métal-milieu hydrocarbure. La structure de cette double couche en liaison avec le phénomène d'adsorption à l'interface (courbe électrocapillaire, énergie libre de surface, charge, capacité différentielle sont abordés. L'importance de la connaissance du potentiel de charge nulle est montrée. Une revue bibliographique des moyens d'accès à la mesure des capacités différentielles de la double couche est farte, l'objectif à atteindre étant le choix d'une technique de mesure possible en milieu hydrocarbure, sur électrode solide. Une méthode, basée sur l'étude du début de la charge de la double couche électrique et utilisant la superposition d'une tension carrée à une tension continue maintenue constante, est développée et l'étude théorique du circuit réalisée. Des courbes capacité différentielle = f (tension de polarisation sont tracées pour des solutions dans l'heptane de différents additifs utilisés en lubrification. Une réflexion sur les mécanismes d'adsorption est faite à partir de l'exploitation de ces courbes expérimentales. A titre de comparaison quelques tracés de courbes de capacité différentielle sont effectués avec un produit antistatique rendant fortement conducteur les hydrocarbures et un produit antiusure. Enfin un système de référence utilisant une électrode au calomel est proposé. The adsorption phenomena of detergent-dispersant additives contained in lubricating ails is behind for the action of such products. The existence of an electrical double layer is one of the parameters token into consideration when analyzing the métal/hydrocarbon medium interface. The structure of this double layer in connection with the adsorption phenomenon on

  4. Isostatic compression of buffer blocks. Middle scale

    International Nuclear Information System (INIS)

    Ritola, J.; Pyy, E.

    2012-01-01

    Manufacturing of buffer components using isostatic compression method has been studied in small scale in 2008 (Laaksonen 2010). These tests included manufacturing of buffer blocks using different bentonite materials and different compression pressures. Isostatic mould technology was also tested, along with different methods to fill the mould, such as vibration and partial vacuum, as well as a stepwise compression of the blocks. The development of manufacturing techniques has continued with small-scale (30 %) blocks (diameter 600 mm) in 2009. This was done in a separate project: Isostatic compression, manufacturing and testing of small scale (D = 600 mm) buffer blocks. The research on the isostatic compression method continued in 2010 in a project aimed to test and examine the isostatic manufacturing process of buffer blocks at 70 % scale (block diameter 1200 to 1300 mm), and the aim was to continue in 2011 with full-scale blocks (diameter 1700 mm). A total of nine bentonite blocks were manufactured at 70 % scale, of which four were ring-shaped and the rest were cylindrical. It is currently not possible to manufacture full-scale blocks, because there is no sufficiently large isostatic press available. However, such a compression unit is expected to be possible to use in the near future. The test results of bentonite blocks, produced with an isostatic pressing method at different presses and at different sizes, suggest that the technical characteristics, for example bulk density and strength values, are somewhat independent of the size of the block, and that the blocks have fairly homogenous characteristics. Water content and compression pressure are the two most important properties determining the characteristics of the compressed blocks. By adjusting these two properties it is fairly easy to produce blocks at a desired density. The commonly used compression pressure in the manufacturing of bentonite blocks is 100 MPa, which compresses bentonite to approximately

  5. Isostatic compression of buffer blocks. Middle scale

    Energy Technology Data Exchange (ETDEWEB)

    Ritola, J.; Pyy, E. [VTT Technical Research Centre of Finland, Espoo (Finland)

    2012-01-15

    Manufacturing of buffer components using isostatic compression method has been studied in small scale in 2008 (Laaksonen 2010). These tests included manufacturing of buffer blocks using different bentonite materials and different compression pressures. Isostatic mould technology was also tested, along with different methods to fill the mould, such as vibration and partial vacuum, as well as a stepwise compression of the blocks. The development of manufacturing techniques has continued with small-scale (30 %) blocks (diameter 600 mm) in 2009. This was done in a separate project: Isostatic compression, manufacturing and testing of small scale (D = 600 mm) buffer blocks. The research on the isostatic compression method continued in 2010 in a project aimed to test and examine the isostatic manufacturing process of buffer blocks at 70 % scale (block diameter 1200 to 1300 mm), and the aim was to continue in 2011 with full-scale blocks (diameter 1700 mm). A total of nine bentonite blocks were manufactured at 70 % scale, of which four were ring-shaped and the rest were cylindrical. It is currently not possible to manufacture full-scale blocks, because there is no sufficiently large isostatic press available. However, such a compression unit is expected to be possible to use in the near future. The test results of bentonite blocks, produced with an isostatic pressing method at different presses and at different sizes, suggest that the technical characteristics, for example bulk density and strength values, are somewhat independent of the size of the block, and that the blocks have fairly homogenous characteristics. Water content and compression pressure are the two most important properties determining the characteristics of the compressed blocks. By adjusting these two properties it is fairly easy to produce blocks at a desired density. The commonly used compression pressure in the manufacturing of bentonite blocks is 100 MPa, which compresses bentonite to approximately

  6. Ganglion block. When and how?

    International Nuclear Information System (INIS)

    Bale, R.

    2015-01-01

    Increasing understanding of the anatomy and physiology of neural structures has led to the development of surgical and percutaneous neurodestructive methods in order to target and destroy various components of afferent nociceptive pathways. The dorsal root ganglia and in particular the ganglia of the autonomous nervous system are targets for radiological interventions. The autonomous nervous system is responsible for the regulation of organ functions, sweating, visceral and blood vessel-associated pain. Ganglia of the sympathetic chain and non-myelinized autonomous nerves can be irreversibly destroyed by chemical and thermal ablation. Computed tomography (CT)-guided sympathetic nerve blocks are well established interventional radiological procedures which lead to vasodilatation, reduction of sweating and reduction of pain associated with the autonomous nervous system. Sympathetic blocks are applied for the treatment of various vascular diseases including critical limb ischemia. Other indications for thoracic and lumbar sympathectomy include complex regional pain syndrome (CRPS), chronic tumor associated pain and hyperhidrosis. Neurolysis of the celiac plexus is an effective palliative pain treatment particularly in patients suffering from pancreatic cancer. Percutaneous dorsal root ganglion rhizotomy can be performed in selected patients with radicular pain that is resistant to conventional pharmacological and interventional treatment. (orig.) [de

  7. Randomized Block Cubic Newton Method

    KAUST Repository

    Doikov, Nikita; Richtarik, Peter

    2018-01-01

    We study the problem of minimizing the sum of three convex functions: a differentiable, twice-differentiable and a non-smooth term in a high dimensional setting. To this effect we propose and analyze a randomized block cubic Newton (RBCN) method, which in each iteration builds a model of the objective function formed as the sum of the natural models of its three components: a linear model with a quadratic regularizer for the differentiable term, a quadratic model with a cubic regularizer for the twice differentiable term, and perfect (proximal) model for the nonsmooth term. Our method in each iteration minimizes the model over a random subset of blocks of the search variable. RBCN is the first algorithm with these properties, generalizing several existing methods, matching the best known bounds in all special cases. We establish ${\\cal O}(1/\\epsilon)$, ${\\cal O}(1/\\sqrt{\\epsilon})$ and ${\\cal O}(\\log (1/\\epsilon))$ rates under different assumptions on the component functions. Lastly, we show numerically that our method outperforms the state-of-the-art on a variety of machine learning problems, including cubically regularized least-squares, logistic regression with constraints, and Poisson regression.

  8. Randomized Block Cubic Newton Method

    KAUST Repository

    Doikov, Nikita

    2018-02-12

    We study the problem of minimizing the sum of three convex functions: a differentiable, twice-differentiable and a non-smooth term in a high dimensional setting. To this effect we propose and analyze a randomized block cubic Newton (RBCN) method, which in each iteration builds a model of the objective function formed as the sum of the natural models of its three components: a linear model with a quadratic regularizer for the differentiable term, a quadratic model with a cubic regularizer for the twice differentiable term, and perfect (proximal) model for the nonsmooth term. Our method in each iteration minimizes the model over a random subset of blocks of the search variable. RBCN is the first algorithm with these properties, generalizing several existing methods, matching the best known bounds in all special cases. We establish ${\\\\cal O}(1/\\\\epsilon)$, ${\\\\cal O}(1/\\\\sqrt{\\\\epsilon})$ and ${\\\\cal O}(\\\\log (1/\\\\epsilon))$ rates under different assumptions on the component functions. Lastly, we show numerically that our method outperforms the state-of-the-art on a variety of machine learning problems, including cubically regularized least-squares, logistic regression with constraints, and Poisson regression.

  9. Thyroid blocking after nuclear accidents

    International Nuclear Information System (INIS)

    Rendl, J.; Reiners, C.

    1999-01-01

    Following the Chernobyl accident a marked increase in thyroid cancer incidence among the children in Belarus, the Ukraine and Russia has been detected, strongly suggesting a causal relationship to the large amounts of radioactive iodine isotopes in the resulting fallout. Taking into account the Chernobyl experience the German Committee on Radiation Protection decided to reduce the intervention levels on the basis of the 1989 WHO recommendations and adopted a new concept concerning thyroid blocking in response to nuclear power plant accidents. Experimental animal studies and theoretical considerations show that thyroid blocking with potassium iodide (KI) in a dose of about 1.4 mg per kg body weight is most effective in reducing irradiation to the thyroid from the intake of radioiodine nuclides, provided KI is given within 2 hours after exposure. According to the new concept, persons over 45 years of age should not take iodine tablets because the drug could cause a greater health risk due to prevalent functional thyroid autonomy in this age group than the radioactive iodine averted by KI. On the basis of accident analysis and the new philosophy suitable distribution strategies and logistics are proposed and discussed. (orig.) [de

  10. [Food additives and healthiness].

    Science.gov (United States)

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  11. [Complete atrioventricular block in Duchenne muscular dystrophy].

    Science.gov (United States)

    Kuru, Satoshi; Tanahashi, Tamotsu; Matsumoto, Shinjirou; Kitamura, Tetsuya; Konagaya, Masaaki

    2012-01-01

    We report a case of complete atrioventricular (AV) block in a 40-year-old patient with Duchenne muscular dystrophy (DMD). While he was bed-ridden and required mechanical ventilation, his cardiac involvement was mild. He had the deletion of exon 45-52 in the dystrophin gene. He underwent transient complete AV block and came to require pacemaker implantation due to recurrence of complete AV block ten days after the first attack. Electrophysiological study revealed mild prolonged AH and HV interval. Although DMD patients with AV block have been rarely reported so far, attention should be paid to AV block for patients who prolonged their lives.

  12. ALS insertion device block measurement and inspection

    International Nuclear Information System (INIS)

    Marks, S.; Carrieri, J.; Cook, C.; Hassenzahl, W.V.; Hoyer, E.; Plate, D.

    1991-05-01

    The performance specifications for ALS insertion devices require detailed knowledge and strict control of the Nd-Fe-B permanent magnet blocks incorporated in these devices. This paper describes the measurement and inspection apparatus and the procedures designed to qualify and characterize these blocks. A detailed description of a new, automated Helmholtz coil facility for measurement of the three components of magnetic moment is included. Physical block inspection and magnetic moment measurement procedures are described. Together they provide a basis for qualifying blocks and for specifying placement of blocks within an insertion devices' magnetic structures. 1 ref., 4 figs

  13. How to block and tackle the face.

    Science.gov (United States)

    Zide, B M; Swift, R

    1998-03-01

    Regional blocking techniques as noted in dentistry, anesthesia, and anatomy texts may result in inconsistent and imperfect analgesia when needed for facial aesthetic surgery. The advent of laser facial surgery and more complicated aesthetic facial procedures has thus increased the demand for anesthesia support. Surgeons should know a fail-safe method of nerve blocks. Fresh cadaver dissections are used to demonstrate a series of eight regional nerve-blocking routes. This sequence of bilateral blocks will routinely provide profound full facial anesthesia. Certain groupings of blocks are effective for perioral or periorbital laser surgery.

  14. Double smectic self-assembly in block copolypeptide complexes

    KAUST Repository

    Haataja, Johannes S.; Houbenov, Nikolay; Iatrou, Hermis; Hadjichristidis, Nikolaos; Karatzas, A.; Faul, Charl F. J.; Rannou, Patrice; Ikkala, Olli T.

    2012-01-01

    We show double smectic-like self-assemblies in the solid state involving alternating layers of different polypeptide α-helices. We employed rod-coil poly(γ-benzyl l-glutamate)-block-poly(l-lysine) (PBLG-b-PLL) as the polymeric scaffold, where the PLL amino residues were ionically complexed to di-n-butyl phosphate (diC4P), di(2-ethylhexyl) phosphate (diC2/6P), di(2-octyldodecyl) phosphate (diC8/12P), or di-n-dodecyl phosphate (diC12P), forming PBLG-b-PLL(diC4P), PBLG-b-PLL(diC2/6P), PBLG-b-PLL(diC8/12P), and PBLG-b-PLL(diC12P) complexes, respectively. The complexes contain PBLG α-helices of fixed diameter and PLL-surfactant complexes adopting either α-helices of tunable diameters or β-sheets. For PBLG-b-PLL(diC4P), that is, using a surfactant with short n-butyl tails, both blocks were α-helical, of roughly equal diameter and thus with minor packing frustrations, leading to alternating PBLG and PLL(diC4P) smectic layers of approximately perpendicular alignment of both types of α-helices. Surfactants with longer and branched alkyl tails lead to an increased diameter of the PLL-surfactant α-helices. Smectic alternating PBLG and PLL(diC2/6P) layers involve larger packing frustration, which leads to poor overall order and suggests an arrangement of tilted PBLG α-helices. In PBLG-b-PLL(diC8/12P), the PLL(diC8/12P) α-helices are even larger and the overall structure is poor. Using a surfactant with two linear n-dodecyl tails leads to well-ordered β-sheet domains of PLL(diC12P), consisting of alternating PLL and alkyl chain layers. This dominates the whole assembly, and at the block copolypeptide length scale, the PBLG α-helices do not show internal order and have poor organization. Packing frustration becomes an important aspect to design block copolypeptide assemblies, even if frustration could be relieved by conformational imperfections. The results suggest pathways to control hierarchical liquid-crystalline assemblies by competing interactions and by

  15. Double smectic self-assembly in block copolypeptide complexes

    KAUST Repository

    Haataja, Johannes S.

    2012-11-12

    We show double smectic-like self-assemblies in the solid state involving alternating layers of different polypeptide α-helices. We employed rod-coil poly(γ-benzyl l-glutamate)-block-poly(l-lysine) (PBLG-b-PLL) as the polymeric scaffold, where the PLL amino residues were ionically complexed to di-n-butyl phosphate (diC4P), di(2-ethylhexyl) phosphate (diC2/6P), di(2-octyldodecyl) phosphate (diC8/12P), or di-n-dodecyl phosphate (diC12P), forming PBLG-b-PLL(diC4P), PBLG-b-PLL(diC2/6P), PBLG-b-PLL(diC8/12P), and PBLG-b-PLL(diC12P) complexes, respectively. The complexes contain PBLG α-helices of fixed diameter and PLL-surfactant complexes adopting either α-helices of tunable diameters or β-sheets. For PBLG-b-PLL(diC4P), that is, using a surfactant with short n-butyl tails, both blocks were α-helical, of roughly equal diameter and thus with minor packing frustrations, leading to alternating PBLG and PLL(diC4P) smectic layers of approximately perpendicular alignment of both types of α-helices. Surfactants with longer and branched alkyl tails lead to an increased diameter of the PLL-surfactant α-helices. Smectic alternating PBLG and PLL(diC2/6P) layers involve larger packing frustration, which leads to poor overall order and suggests an arrangement of tilted PBLG α-helices. In PBLG-b-PLL(diC8/12P), the PLL(diC8/12P) α-helices are even larger and the overall structure is poor. Using a surfactant with two linear n-dodecyl tails leads to well-ordered β-sheet domains of PLL(diC12P), consisting of alternating PLL and alkyl chain layers. This dominates the whole assembly, and at the block copolypeptide length scale, the PBLG α-helices do not show internal order and have poor organization. Packing frustration becomes an important aspect to design block copolypeptide assemblies, even if frustration could be relieved by conformational imperfections. The results suggest pathways to control hierarchical liquid-crystalline assemblies by competing interactions and by

  16. Functional materials derived from block copolymer self-assembly

    DEFF Research Database (Denmark)

    Li, Tao

    deposition methods, namely nanocasting and atomic layer deposition (ALD) will be applied to fabricate compact, inter-connected, and continuous metal oxide films. In this way, the structure integrity will be preserved after template removal during the annealing procedure. Another objective of this project......-casting, the block copolymer self-organizes into monolayer packed sphere pattern, without any surface treatment of the substrate and annealing process. Arrays of nano-pillars and nanowells of various materials are fabricated in dry etch processes over wafer scale without defects. We also show an in situ Al2O3 hard...

  17. Improved organic light-emitting device with tris-(8-hydroxyquinoline) aluminium inserted between hole-injection layer and hole-transporting layer

    Energy Technology Data Exchange (ETDEWEB)

    Divayana, Y [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore (Singapore); Sun, X W [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore (Singapore); Chen, B J [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore (Singapore); Sarma, K R [Aerospace Electronic Systems, Honeywell, 21111 N 19th Avenue, Phoenix, AZ 85027 (United States)

    2007-01-07

    A layer of tris-(8-hydroxyquinoline) aluminium (Alq{sub 3}), which is normally used as an electron-transporting and emissive layer, was incorporated between the hole-transporting layer and the hole-injection layer to balance the electron-hole injection. The Alq{sub 3} layer performed to block the hole current which is a majority carrier in a typical organic light-emitting device. An increase in current efficiency by almost 30%, from 3.1 to 4.0 cd A{sup -1}, with a minimum voltage shift was achieved with a 2 nm Alq{sub 3} layer as a hole-blocking layer. A reduction in HTL thickness was observed to reduce the efficiency due to electron leakage to the HIL, whereby an inefficient exciplex emission was observed.

  18. Multifunctional MgO Layer in Perovskite Solar Cells.

    Science.gov (United States)

    Guo, Xudong; Dong, Haopeng; Li, Wenzhe; Li, Nan; Wang, Liduo

    2015-06-08

    A multifunctional magnesium oxide (MgO) layer was successfully introduced into perovskite solar cells (PSCs) to enhance their performance. MgO was coated onto the surface of mesoporous TiO(2) by the decomposition of magnesium acetate and, therefore, could block contact between the perovskite and TiO(2). X-ray photoelectron spectroscopy and infrared spectroscopy showed that the amount of H(2)O/hydroxyl absorbed on the TiO(2) decreased after MgO modification. The UV/Vis absorption spectra of the perovskite with MgO modification revealed an enhanced photoelectric performance compared with that of unmodified perovskite after UV illumination. In addition to the photocurrent, the photovoltage and fill factor also showed an enhancement after modification, which resulted in an increase in the overall efficiency of the cell from 9.6 to 13.9 %. Electrochemical impedance spectroscopy (EIS) confirmed that MgO acts as an insulating layer to reduce charge recombination. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Perineural versus intravenous clonidine as an adjuvant to Bupivacaine in supraclavicular Brachial plexus block

    Directory of Open Access Journals (Sweden)

    Vikram Bedi

    2017-07-01

    Conclusion: Addition of clonidine 2mcg/kg to 28 ml of 0.5% bupivacaine in brachial plexus blocks results in a faster onset, increased duration of block and longer postoperative pain relief when compared to bupivacaine alone. These advantages are not observed when the same dose of clonidine is injected intravenously.

  20. Quantitative NMR Approach to Optimize the Formation of Chemical Building Blocks from Abundant Carbohydrates

    DEFF Research Database (Denmark)

    Elliot, Samuel Gilbert; Tolborg, Søren; Sádaba, Irantzu

    2017-01-01

    -containing catalysts such as Sn-Beta. These compounds are potential building blocks for polyesters with additional olefin and alcohol functionalities. We employ an NMR approach to identify, quantify and optimize the formation these building blocks in the chemocatalytic transformation of abundant carbohydrates by Sn...

  1. Differential erosion and the formation of layered yardangs in the Loulan region (Lop Nur), eastern Tarim Basin

    Science.gov (United States)

    Lin, Yongchong; Xu, Lishuai; Mu, Guijin

    2018-02-01

    Yardangs are a type of wind-sculpted landform which generally form in hyper-arid regions. Several factors affect the development of yardangs, and the relative importance of these factors likely varies with differences in regional environmental factors. In the Loulan region of Lop Nur, wind dynamics are the principal factor affecting the development of yardangs. However, layered yardangs, which have undergone a unique form of differential erosion, are common in the region. These erosional landforms differ from typical yardangs which are eroded solely by abrasion and deflation. We conducted field and laboratory investigations of layered yardangs to determine their origin. The results indicate that there are two types of strata comprising the yardangs: uncompacted sand-silt layers, with a lower carbonate content; and compacted clay-silt layers, with a higher carbonate content. Both types of strata are horizontal and occur in alternating layers. This type of structure enables the wind to more easily erode the less resistant sand-silt layers at different heights, leaving the more resistant compacted clay-silt layers relatively intact. Eventually the undercut remnant clay-silt layers collapse once the weight of the suspended strata exceeds their elastic resistance (more than 90% of the fallen blocks have length/thickness ratios between 1.2 and 2.5). Therefore, in addition to wind dynamics, the lithology and structure of the strata are important factors affecting the development of the layered yardangs. This type of differential erosion accelerates the development of the yardangs in the Loulan region.

  2. Highly conductive side chain block copolymer anion exchange membranes.

    Science.gov (United States)

    Wang, Lizhu; Hickner, Michael A

    2016-06-28

    Block copolymers based on poly(styrene) having pendent trimethyl styrenylbutyl ammonium (with four carbon ring-ionic group alkyl linkers) or benzyltrimethyl ammonium groups with a methylene bridge between the ring and ionic group were synthesized by reversible addition-fragmentation radical (RAFT) polymerization as anion exchange membranes (AEMs). The C4 side chain polymer showed a 17% increase in Cl(-) conductivity of 33.7 mS cm(-1) compared to the benzyltrimethyl ammonium sample (28.9 mS cm(-1)) under the same conditions (IEC = 3.20 meq. g(-1), hydration number, λ = ∼7.0, cast from DMF/1-propanol (v/v = 3 : 1), relative humidity = 95%). As confirmed by small angle X-ray scattering (SAXS), the side chain block copolymers with tethered ammonium cations showed well-defined lamellar morphologies and a significant reduction in interdomain spacing compared to benzyltrimethyl ammonium containing block copolymers. The chemical stabilities of the block copolymers were evaluated under severe, accelerated conditions, and degradation was observed by (1)H NMR. The block copolymer with C4 side chain trimethyl styrenylbutyl ammonium motifs displayed slightly improved stability compared to that of a benzyltrimethyl ammonium-based AEM at 80 °C in 1 M NaOD aqueous solution for 30 days.

  3. Effect of Epidural Block under General Anesthesia on Pulse Transit Time

    International Nuclear Information System (INIS)

    Choi, Byeong Cheol; Kim, Seong Min; Jung, Dong Keun; Kim, Gi Ryon; Lee, He Jeong; Jeon, Gye Rock

    2005-01-01

    Epidural block under general anesthesia has been widely used to control postoperative pain. In this anesthetic state many hemodynamic parameters are changed. Moreover pulse transit time is influenced by this memodynamic change. PPT change in the finger and the toe due to relaxation of arterial wall muscle after general anesthesia and epidural block under general anesthesia. This study, in the both general anesthesia and epidural block under general anesthesia, ΔPTT of the toe and of the finger are measured. In addition, ΔPTT(toe-finger) of the epidural block under general anesthesia and of the general anesthesia were compared

  4. Salt attack in parking garage in block of flats

    Science.gov (United States)

    Beran, Pavel; Frankeová, Dita; Pavlík, Zbyšek

    2017-07-01

    In recent years many new block of flats with parking garages placed inside the buildings were constructed. This tendency brings beyond question benefits for residents and also for city planning, but it requires new design and structural approaches and advanced material and construction solutions. The analysis of plaster damage on partition wall in parking garage in one of these buildings is presented in the paper. The damage of studied plaster is caused by the salts which are transported together with snow on cars undercarriage into garage area during winter. The snow melts and water with dissolved salts is transported by the capillary suction from concrete floor into the rendered partition wall. Based on the interior temperature, adsorbed water with dissolved chlorides evaporates and from the over saturated pore solution are formed salt crystals that damages the surface plaster layers. This damage would not occur if the partition wall was correctly isolated from the floor finish layer in the parking garage.

  5. Additives in yoghurt production

    Directory of Open Access Journals (Sweden)

    Milna Tudor

    2008-02-01

    Full Text Available In yoghurt production, mainly because of sensory characteristics, different types of additives are used. Each group, and also each substance from the same group has different characteristics and properties. For that reason, for improvement of yoghurt sensory characteristics apart from addition selection, the quantity of the additive is very important. The same substance added in optimal amount improves yoghurt sensory attributes, but too small or too big addition can reduce yoghurt sensory attributes. In this paper, characteristics and properties of mostly used additives in yoghurt production are described; skimmed milk powder, whey powder, concentrated whey powder, sugars and artificial sweeteners, fruits, stabilizers, casein powder, inulin and vitamins. Also the impact of each additive on sensory and physical properties of yoghurt, syneresis and viscosity, are described, depending on used amount added in yoghurt production.

  6. Additive manufacturing with polypropylene microfibers.

    Science.gov (United States)

    Haigh, Jodie N; Dargaville, Tim R; Dalton, Paul D

    2017-08-01

    The additive manufacturing of small diameter polypropylene microfibers is described, achieved using a technique termed melt electrospinning writing. Sequential fiber layering, which is important for accurate three-dimensional fabrication, was achieved with the smallest fiber diameter of 16.4±0.2μm obtained. The collector speed, temperature and melt flow rate to the nozzle were optimized for quality and minimal fiber pulsing. Of particular importance to the success of this method is appropriate heating of the collector plate, so that the electrostatically drawn filament adheres during the direct-writing process. By demonstrating the direct-writing of polypropylene, new applications exploiting the favorable mechanical, stability and biocompatible properties of this polymer are envisaged. Copyright © 2017. Published by Elsevier B.V.

  7. Exercising with blocked muscle glycogenolysis

    DEFF Research Database (Denmark)

    Nielsen, Tue L; Pinós, Tomàs; Brull, Astrid

    2018-01-01

    BACKGROUND: McArdle disease (glycogen storage disease type V) is an inborn error of skeletal muscle metabolism, which affects glycogen phosphorylase (myophosphorylase) activity leading to an inability to break down glycogen. Patients with McArdle disease are exercise intolerant, as muscle glycogen......-derived glucose is unavailable during exercise. Metabolic adaptation to blocked muscle glycogenolysis occurs at rest in the McArdle mouse model, but only in highly glycolytic muscle. However, it is unknown what compensatory metabolic adaptations occur during exercise in McArdle disease. METHODS: In this study, 8......-week old McArdle and wild-type mice were exercised on a treadmill until exhausted. Dissected muscles were compared with non-exercised, age-matched McArdle and wild-type mice for histology and activation and expression of proteins involved in glucose uptake and glycogenolysis. RESULTS: Investigation...

  8. Used, Blocking and Sleeping Patents

    DEFF Research Database (Denmark)

    Torrisi, Salvatore; Gambardella, Alfonso; Giuri, Paola

    2016-01-01

    This paper employs data from a large-scale survey (InnoS&T) of inventors in Europe, the USA, and Japan who were listed in patent applications filed at the European Patent Office with priority years between 2003 and 2005. We provide evidence regarding the reasons for patenting and the ways in which...... patents are being utilized. A substantial share of patents is neither used internally nor for market transactions, which confirms the importance of strategic patenting and inefficiency in the management of intellectual property. We investigate different types of unused patents—unused blocking patents...... and sleeping patents. We also examine the association between used and unused patents and their characteristics such as family size, scope, generality and overlapping claims, technology area, type of applicant, and the competitive environment from where these patents originate. We discuss our results...

  9. LARGE BLOCK TEST STATUS REPORT

    International Nuclear Information System (INIS)

    D.G. WILDER, W. LIN, S.C. BLAIR, T. BUSCHECK, R.C. CARLSON, K. LEE, A. MEIKE, A.L. RAMIREZ, J.L. WAGONER, AND J. WANG

    1997-01-01

    This report is intended to serve as a status report, which essentially transmits the data that have been collected to date on the Large Block Test (LBT). The analyses of data will be performed during FY98, and then a complete report will be prepared. This status report includes introductory material that is not needed merely to transmit data but is available at this time and therefore included. As such, this status report will serve as the template for the future report, and the information is thus preserved. The United States Department of Energy (DOE) is investigatinq the suitability of Yucca Mountain (YM) as a potential site for the nation's first high-level nuclear waste repository. As shown in Fig. 1-1, the site is located about 120 km northwest of Las Vegas, Nevada, in an area of uninhabited desert

  10. Vagal Blocking for Obesity Control

    DEFF Research Database (Denmark)

    Johannessen, Helene; Revesz, David; Kodama, Yosuke

    2017-01-01

    : VBLOC reduced body weight and food intake, which was associated with increased satiety but not with decreased hunger. Brain activities in response to VBLOC included increased gene expression of leptin and CCKb receptors, interleukin-1β, tumor necrosis factor, and transforming growth factor β1......BACKGROUND: Recently, the US FDA has approved "vagal blocking therapy or vBLoc® therapy" as a new treatment for obesity. The aim of the present study was to study the mechanism-of-action of "VBLOC" in rat models. METHODS: Rats were implanted with VBLOC, an intra-abdominal electrical device...... with leads placed around gastric vagal trunks through an abdominal incision and controlled by wireless device. Body weight, food intake, hunger/satiety, and metabolic parameters were monitored by a comprehensive laboratory animal monitoring system. Brain-gut responses were analyzed physiologically. RESULTS...

  11. Cavity nonlinear optics with layered materials

    Directory of Open Access Journals (Sweden)

    Fryett Taylor

    2017-12-01

    Full Text Available Unprecedented material compatibility and ease of integration, in addition to the unique and diverse optoelectronic properties of layered materials, have generated significant interest in their utilization in nanophotonic devices. While initial nanophotonic experiments with layered materials primarily focused on light sources, modulators, and detectors, recent efforts have included nonlinear optical devices. In this paper, we review the current state of cavity-enhanced nonlinear optics with layered materials. Along with conventional nonlinear optics related to harmonic generation, we report on emerging directions of nonlinear optics, where layered materials can potentially play a significant role.

  12. Emulsion Solvent Evaporation-Induced Self-Assembly of Block Copolymers Containing pH-Sensitive Block.

    Science.gov (United States)

    Wu, Yuqing; Wang, Ke; Tan, Haiying; Xu, Jiangping; Zhu, Jintao

    2017-09-26

    A simple yet efficient method is developed to manipulate the self-assembly of pH-sensitive block copolymers (BCPs) confined in emulsion droplets. Addition of acid induces significant variation in morphological transition (e.g., structure and surface composition changes) of the polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) assemblies, due to the hydrophobic-hydrophilic transition of the pH-sensitive P4VP block via protonation. In the case of pH > pKa (P4VP) (pKa (P4VP) = 4.8), the BCPs can self-assemble into pupa-like particles because of the nearly neutral wetting of PS and P4VP blocks at the oil/water interface. As expected, onion-like particles obtained when pH is slightly lower than pKa (P4VP) (e.g., pH = 3.00), due to the interfacial affinity to the weakly hydrophilic P4VP block. Interestingly, when pH was further decreased to ∼2.5, interfacial instability of the emulsion droplets was observed, and each emulsion droplet generated nanoscale assemblies including vesicles, worm-like and/or spherical micelles rather than a nanostructured microparticle. Furthermore, homopolymer with different molecular weights and addition ratio are employed to adjust the interactions among copolymer blocks. By this means, particles with hierarchical structures can be obtained. Moreover, owing to the kinetically controlled processing, we found that temperature and stirring speed, which can significantly affect the kinetics of the evaporation of organic solvent and the formation of particles, played a key role in the morphology of the assemblies. We believe that manipulation of the property for the aqueous phase is a promising strategy to rationally design and fabricate polymeric assemblies with desirable shapes and internal structures.

  13. Three-dimensional Reconstruction of Block Shape Irregularity and its Effects on Block Impacts Using an Energy-Based Approach

    Science.gov (United States)

    Zhang, Yulong; Liu, Zaobao; Shi, Chong; Shao, Jianfu

    2018-04-01

    This study is devoted to three-dimensional modeling of small falling rocks in block impact analysis in energy view using the particle flow method. The restitution coefficient of rockfall collision is introduced from the energy consumption mechanism to describe rockfall-impacting properties. Three-dimensional reconstruction of falling block is conducted with the help of spherical harmonic functions that have satisfactory mathematical properties such as orthogonality and rotation invariance. Numerical modeling of the block impact to the bedrock is analyzed with both the sphere-simplified model and the 3D reconstructed model. Comparisons of the obtained results suggest that the 3D reconstructed model is advantageous in considering the combination effects of rockfall velocity and rotations during colliding process. Verification of the modeling is carried out with the results obtained from other experiments. In addition, the effects of rockfall morphology, surface characteristics, velocity, and volume, colliding damping and relative angle are investigated. A three-dimensional reconstruction modulus of falling blocks is to be developed and incorporated into the rockfall simulation tools in order to extend the modeling results at block scale to slope scale.

  14. Cooperative storage of shared files in a parallel computing system with dynamic block size

    Science.gov (United States)

    Bent, John M.; Faibish, Sorin; Grider, Gary

    2015-11-10

    Improved techniques are provided for parallel writing of data to a shared object in a parallel computing system. A method is provided for storing data generated by a plurality of parallel processes to a shared object in a parallel computing system. The method is performed by at least one of the processes and comprises: dynamically determining a block size for storing the data; exchanging a determined amount of the data with at least one additional process to achieve a block of the data having the dynamically determined block size; and writing the block of the data having the dynamically determined block size to a file system. The determined block size comprises, e.g., a total amount of the data to be stored divided by the number of parallel processes. The file system comprises, for example, a log structured virtual parallel file system, such as a Parallel Log-Structured File System (PLFS).

  15. Temperature tunable micellization of polystyrene-block-poly(2-vinylpyridine) at Si-ionic liquid interface.

    Science.gov (United States)

    Lu, Haiyun; Lee, Dong Hyun; Russell, Thomas P

    2010-11-16

    Highly ordered and stable micelles formed from both symmetric and asymmetric block copolymers of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) at the Si-ionic liquid (IL) interface have been investigated by scanning force microscopy (SFM) and transmission electron microscopy (TEM). The 1-butyl-3-methylimidazolium trifluoromethanesulfonate IL, a selective and temperature-tunable solvent for the P2VP block, was used and gave rise to block copolymer micelles having different morphologies that strongly depended on the annealing temperature. The effects of film thickness, molecular weight of block copolymers, and experimental conditions, such as preannealing, rinsing, and substrate properties, on the morphologies of block copolymer micelles were also studied. In addition, spherical micelles consisting of PS core and P2VP shell could also be obtained by core-corona inversion by annealing the as-coated micellar film in the IL at high temperatures. The possible mechanism for micelle formation is discussed.

  16. VSWI Wetlands Advisory Layer

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset represents the DEC Wetlands Program's Advisory layer. This layer makes the most up-to-date, non-jurisdictional, wetlands mapping avaiable to the public...

  17. Contribution of ultrasound-guided fine-needle aspiration cell blocks of metastatic supraclavicular lymph nodes to the diagnosis of lung cancer

    Directory of Open Access Journals (Sweden)

    Hai-Ying Tian

    2015-01-01

    Conclusion: Cell-block samples from US-guided FNA is a promising, relatively noninvasive technique to provide additional information in lung cancer diagnosis. Analysis of cell blocks allows for genetic analysis of the patients with supraclavicular lymph nodes metastasis.

  18. Minimum Description Length Block Finder, a Method to Identify Haplotype Blocks and to Compare the Strength of Block Boundaries

    OpenAIRE

    Mannila, H.; Koivisto, M.; Perola, M.; Varilo, T.; Hennah, W.; Ekelund, J.; Lukk, M.; Peltonen, L.; Ukkonen, E.

    2003-01-01

    We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the ...

  19. LEO resistant PI-B-PDMS block copolymer films for solar array applications

    NARCIS (Netherlands)

    Lonkhuyzen, H. van; Bongers, E.; Fischer, H.R.; Dingemans, T.J.; Semprimoschnig, C.

    2013-01-01

    Due to their low atomic oxygen erosion yields PI-b-PDMS block copolymer films have considerable potential for application onto space exposed surfaces of satellites in low earth orbit. On solar arrays these materials might be used as electrical electrical insulation film, flexprint outer layer,

  20. Asymmetric block copolymer membranes with ultrahigh porosity and hierarchical pore structure by plain solvent evaporation

    KAUST Repository

    Yu, H.

    2016-09-14

    Membranes with a hierarchical porous structure could be manufactured from a block copolymer blend by pure solvent evaporation. Uniform pores in a 30 nm thin skin layer supported by a macroporous structure were formed. This new process is attractive for membrane production because of its simplicity and the lack of liquid waste.