bluuebunny/crossref_metadata_2025_split huggingface dataset:
View-based strategy for reorientation by geometry
Authors: Pecchia Tommaso , Vallortigara Giorgio 
Published: August 2010

SUMMARY
Human and non-human animals can use geometric information (metric information and left–right discrimination sense) to reorient themselves in an environment. The hypothesis that in so doing they rely on allocentric (map-like) representations has received wide consensus. However, theoretical models suggest that egocentric representations may represent efficient strategies for visuo-spatial navigation. Here, we provide, for the first time, evidence that a view-based strategy is effectively used by animals to reorient themselves in an array of landmarks. Domestic chicks were trained to locate a food-reward in a rectangular array of either four indistinguishable or distinctive pipes. In the key experimental series, the pipes had four openings, only one of which allowed the chicks to access the reward. The direction of the open access relative to the array was either maintained stable or it was changed throughout training. The relative position of the pipes in the array was maintained stable in both training conditions. Chicks reoriented according to configural geometry as long as the open access pointed in the same direction during training but failed when the positions of the openings was changed throughout training. When the correct pipe was characterized by a distinctive featural cue, chicks learnt to locate the reward irrespective of the stability of the direction to openings, indicating that place-navigation was dissociated from non-spatial learning. These findings provide evidence that view-based strategies to reorient by geometry could be used by animals.
The neuronal proteins CIPP, Cypin and IRSp53 form a tripartite complex mediated by PDZ and SH3 domains
Authors: Barilari Manuela , Dente Luciana 
Published: August 2010

Abstract
Here we report the dissection of a tripartite complex formed by CIPP (channel-interacting PDZ protein), IRSp53 (insulin receptor tyrosine kinase substrate protein) and Cypin (cytosolic PSD-95 interactor) in cultured cells. The three proteins are expressed in similar neuronal districts, where CIPP binds to different membrane channels and receptors, IRSp53 regulates the morphogenesis of actin-rich dendritic spines, and Cypin promotes dendrite branching and patterning by binding to tubulin heterodimers. We observed that the interaction among the three proteins is mediated by small binding domains: CIPP works as a bridge, linking the carboxy-termini of IRSp53 and Cypin with its PDZ domains; IRSp53 connects Cypin, through an unusual SH3-mediated association, which can be impaired by substituting two crucial positively charged residues of Cypin. The observation that the three engineered proteins co-localize in the cytoplasm, and at the tip of induced neurites in neuronal cells, raises the interesting possibility that they work together in the formation of neuronal protrusions.
Synthesis and Characterization of Bimetallic Pd-Co Nano Magnetic Materials in Mesoporous Silica
Authors: Tatineni Balaji , Kumar Dhananjay , Perkins Joslyn , Yarmolenko Sergey , Kuila Debasish 
Published: August 2010

ABSTRACTAn one-pot procedure was developed for the synthesis of mesoporous silica containing bimetallic PdCo using Pd(NO3)2 and CoCl2, and cetyl trimethyl ammonium bromide (CTAB) as the templating agent, and tetramethoxy silane (TMOS) as the precursor. The materials were characterized using high resolution scanning transmission electron microscopy (HRSTEM), elemental analysis, X-ray diffraction (XRD), and magnetic measurements. The data indicate that the bimetallic Pd-Co nanoparticles are uniformly distributed on the inner pore walls of silica. The magnetic measurements of reduced Pd-Co nanoparticles (4-5 nm) in mesoporous silica reveal a typical ferromagnetic behavior up to 20 K and exhibit superparamagnetic properties above 30 K.
Oxygen vacancy migration in CSZ using density functional theory
Authors: Lee Byeong-Eon , Kim Dae-Hee , Kim Yeong-Cheol 
Published: August 2010

AbstractWe studied oxygen migration in calcia-stabilized cubic zirconia (CSZ) using density functional theory. A Ca atom was substituted for a Zr atom in a 2×2×2 ZrO2 cubic supercell, and an oxygen vacancy was produced to satisfy the charge neutrality condition. We found that the formation energies of an oxygen vacancy, as a function of its location with respect to the Ca atom, were varied. The relative formation energies of the oxygen vacancies located at the first-, second-, third-, and fourth-nearest-neighbors were 0.0, −0.07, 0.19, and 0.19 eV, respectively. Therefore, the oxygen vacancy located at the second-nearest-neighbor site of the Ca atom was the most favorable, the oxygen vacancy located at the first-nearest-neighbor site was the second most favorable, and the oxygen vacancies at the third- and fourth-nearest-neighbor sites were the least favorable. We also calculated the energy barriers for the oxygen vacancy migration between oxygen sites. The energy barriers between the first and the second nearest sites, the second and third nearest sites, and the third and fourth nearest sites were 0.11, 0.46, and 0.23 eV, respectively. Therefore, the oxygen vacancies favored the first- and second-nearest-neighbor oxygen sites when they drifted under an electric field.
Real Structure - Oxygen Mobility Relationship in Nanocrystalline Doped Ceria-Zirconia Fluorite-Like Solid Solutions Promoted by Pt
Authors: Sadykov Vladislav , Mezentseva N. , Muzykantov V. , Efremov D. , Gubanova E. , Sazonova N. , Bobin A. , Paukshtis E. , Ishchenko A. , Voronin V. , Ross J. , Mirodatos C. , van Veen A. 
Published: August 2010

AbstractThis work considers effect of type and content of dopant on the real structure, state of surface Pt species and oxygen mobility of nanocrystalline Lnx(Ce0.5Zr0.5)1-xO2-δ (Ln=La3+, Gd3+, Pr3+/4+) solid solutions prepared by Pechini route. For the reactions of methane selective oxidation and dry reforming into syngas, catalytic activity correlates rather well with either surface (in diluted feeds) or bulk (in realistic feeds) oxygen mobility as well as Pt dispersion controlled by the type and content of a dopant.
Thickness Dependent Effects of Thermal Annealing and Solvent Vapor Treatment of Poly (3-hexylthiophene) and Fullerene Bulk Heterojunction Photovoltaics
Authors: Zhao Zhouying , Rice Lynn , Efstathiadis Harry , Haldar Pradeep 
Published: August 2010

AbstractWe have utilized room-temperature solvent vapor treatment followed by thermal annealing to process bulk heterojunction (BHJ) photovoltaic devices based on blends of poly (3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) of varied active layer thickness. The morphological and photovoltaic performance characteristics of the cells subject to these treatments were found to be dependent on active layer thickness. The devices were characterized using atomic force microscopy (AFM) and opto-electrical and external quantum efficiency measurements in order to analyze the mechanism underlying the observed trend. Performance indicators including fill factor, short-circuit current and power conversion efficiency were correlated to the ordering of device active layers and morphology. The maximum power conversion efficiency achieved was 4.1 %.
Modeling of pH Elevation Due to the Reaction of Saline Groundwater with Hydrated Ordinary Portland Cement Phases
Authors: Honda Akira , Masuda Kenta , Nakanishi Hiroshi , Fujita Hideki , Negishi Kumi 
Published: August 2010

AbstractThermodynamic calculations of the reaction between hydrated OPC phases and saline groundwater indicate an elevated pH > 13, which is not associated with the well known initial release of the alkalis. Instead, the pH elevation is attributed to the generation of OH− accompanied with the precipitation of Friedel's salt (Ca3Al2O6·CaCl2·10H2O; AFm-Cl2) from the reaction of portlandite (Ca(OH)2;CH) and hydrogarnet (Ca3Al2O6·6H2O; C3AH6) with chloride ions from the saline groundwater. If such a reaction mechanism were to occur in the context of the geological disposal of radioactive wastes, the impact of a hyper alkaline plume on other barrier components, such as a bentonite buffer, could be significant. Experimental investigations were therefore conducted using only portlandite and hydrogarnet to represent hydrated OPC and NaCl solution to represent a saline groundwater. The pH elevation was confirmed and showed good agreement with the thermodynamic calculations. The experiments were repeated using hardened OPC paste to confirm this reaction mechanism in the presence of other hydrated OPC phases. In this case, however, the pH elevation was not as high as expected. This deviation can be explained by the residual aluminum, after being partially consumed by AFt and/or AFm, not being wholly assigned to hydrogarnet and a better agreement between the thermodynamic calculations and the experimentally measured results can be made assuming a fraction of aluminum is incorporated into the C-S-H gel phase.
Release of Colloids from Injection Grout Silica Sol
Authors: Hölttä Pirkko L , Hakanen Martti , Lahtinen Mari , Leskinen Anumaija , Lehto Jukka , Juhola Piia 
Published: August 2010

AbstractNon-cementitious grouts have been tested in Olkiluoto for the sealing of fractures with the small hydraulic aperture. A promising non-cementitious inorganic grout material for sealing the fractures of the apertures less than 0.05 mm is commercial colloidal silica called silica sol. The use of colloidal material has to be considered in the long-term safety assessment of a spent nuclear fuel repository. Objective of this work was to determine colloid release from the silica sol gel and stability of silica colloids in different groundwater conditions. To use silica sol as a grout, the injected colloids have to aggregate and form a gel within a predictable time by using a saline solution as an accelerator. Silica sol gel samples were stored in contact with medium salinity and low salinity groundwater simulates. Release of silica colloids and colloid stability was followed by analyzing the colloid concentration, particle size distribution, concentration of reactive silicon, solution pH and zeta potential after one month, half a year and one year. Malvern Zetasizer Nano ZS equipment was used to determine colloidal particle size distributions applying the dynamic light scattering method and zeta potential based on dynamic electrophoretic mobility. The colloidal particle concentration was estimated from Zetasizer measurements applying a standard series. Dissolved reactive silica concentration was determined using the molybdate blue method and total silica concentrations were determined using ICP–MS.
The release and stability of silica colloids were found to be dependent significantly on groundwater salinity. Zeta potential values near zero and the increase in particle size at first and then the disappearance of large particles indicated particle flocculation or coagulation and instable colloidal dispersion in a saline groundwater simulate. In low salinity ground water simulate high negative zeta potential values, small particle size and constant size distribution indicate the existence of stable silica colloids. The concentrations of the released colloids were slightly higher than determined in natural granitic ground waters. Under prevailing saline groundwater conditions in Olkiluoto no significant release of colloids from silica sol is expected but the possible influence of low salinity glacial melt waters has to be considered.
Mechanism of Decarburization of Alloy 617 at 1000°C in Helium Containing CO and CO2 as impurities
Authors: Kumar Deepak , Was Gary S. 
Published: August 2010

ABSTRACTThe objective of this study was to determine the mechanism of decarburization of alloy 617 by investigating the surface and bulk stabilities of the alloy in helium gas containing only CO and CO2 impurities over the temperature range 900-1000°C. For this purpose, the alloy was pre-oxidized at 900°C for 150h in He + 15 ppm CO + 1.6 ppm CO2 gas mixture and subsequently decarburized at 1000°C for additional 100h. The reaction mechanism was corroborated through gas phase analysis, microstructural examination and micro-probe measurements. It was determined that decarburization of the alloy occurred via a reaction between the porous Cr2O3 scale (formed during pre-oxidation) and carbon in the alloy, resulting in chromium metal and carbon monoxide. The chromium diffused back into the matrix, whereas the carbon monoxide escaped the sample through existing cracks and pores in the oxide. Therefore, this study shows that decarburization of alloy 617 occurs in a helium gas containing only CO and CO2 impurities.
Effects of hydrogen permeation on W, Mo and Cu Langmuir probes at ISTTOK
Authors: Nunes D. , Carvalho P.A. , Mateus R. , Nogueira I.D. , Deus A. Moita de , Correia J.B. , Shohoji N. , Gomes R.B. , Fernandes H. , Silva C. , Franco N. , Alves E. 
Published: August 2010

ABSTRACTThe microstructures of tungsten, molybdenum and copper wires used as Langmuir probes at ISTTOK edge plasma have been investigated. The probes cross-sections evidenced extensive grain growth, intergranular bubbles and increased hardness at the plasma exposed regions. Internal surfaces of large bubbles exhibited slip bands resulting from plastic deformation induced by high H2 pressure. Elastic recoil detection analysis was used to measure H concentration profiles. The present results suggest that H2 bubble formation in first wall components under long-term high thermal loads should be closely monitored in nuclear fusion devices. Strategies for H damage mitigation are proposed and discussed.
Catalytic Property of Chemically Pretreated Ni3Al/Ni Two-phase Alloy Foils for Methane Steam Reforming
Authors: Kamikihara Daisuke , Xu Ya , Demura Masahiko , Hirano Toshiyuki 
Published: August 2010

AbstractWe have found that Ni3Al intermetallics shows catalytic activity for H2 production reaction, such as methane steam reforming. In addition to the single-phase Ni3Al, we recently studied the catalytic property of the Ni3Al/Ni two-phase alloy in foil form, and have found that the catalytic activity is not so high in the cold-rolled state. In case of atomized Ni3Al powder with a NiAl/Ni3Al two-phase structure in fact, it is possible to improve the catalytic activity for methane steam reforming by chemical pretreatment in acid and subsequent alkali solutions [1]. The reason was similarly due to the formation of fine Ni particles on the porous surface. These results show a possibility to improve the catalytic activity of Ni3Al/Ni two-phase alloy foils by the two-step chemical treatment similar as powder. In this study we carried out this chemical pretreatment on the surface of Ni3Al/Ni two-phase alloy foil and the catalytic properties for methane steam reforming were evaluated. Ni3Al/Ni two-phase alloy foil (Ni-18 at% Al) with a thickness of 30 μm was used. The chemical pretreatment consisted of two steps, the first step was acid leaching (HCl + HNO3, vol. ratio 3:1) and the second step was alkali leaching (NaOH solution, 20 wt%). Methane steam reforming was carried out in a conventional fixed-bed flow reactor as described in previous reports [1]. Prior to the reaction, the foil was reduced at 873 K for 1 hour by H2. Then isothermal test was carried out at 1123 K for 50 hours under steam-to-carbon ratio of 1. The surface morphology was analyzed using SEM and EDS. The chemically pretreated foil showed much higher catalytic activity for methane steam reforming than the non-treated foil. Especially, the catalytic activity rapidly increased during in the first several hours, and then slowly increased during the subsequent reaction. The maximum H2 production rate was about 30 L/min/m2. This value was 40 times higher than the non-treated foil. This result indicated that the catalytic activity can be improved by chemical pretreatment in acid and subsequent alkali solutions. The surface morphology observation revealed that acid leaching dissolved Ni3Al phase and alkali leaching dissolved Al mainly, resulting in the Ni-enriched surface structure. We consider that this Ni-enriched surface introduced by the two-step chemical treatment attributed to the initial catalytic activity. It also revealed that many fine Ni particles were formed on the surface during the reaction, and the amount of fine Ni particles increased with time. We consider that these Ni particles produced during reaction, contributed to the increase of catalytic activity during reaction. [1] Y. Ma, Y. Xu, M. Demura, D.H. Chun, G.Q. Xie, T. Hirano, Catal. Lett. 112 (2006) 31
Transmission Electron Microscopy of Fe2Nb Laves Phase with C14 structure in Fe-Nb-Ni Alloys
Authors: Takata Naoki , Ishikawa Shigehiro , Matsuo Takashi , Takeyama Masao 
Published: August 2010

AbstractThe lattice structure of the C14 Fe2Nb Laves phase with Ni in solution in Fe-Nb-Ni ternary alloys was examined by transmission electron microscopy. Binary stoichiometric Fe2Nb (Fe-33.3 at.% Nb) exhibits a featureless morphology with a low dislocation density. A similar morphology was observed in stoichiometric Fe2Nb containing 20 at.% Ni and in binary Fe-rich Fe2Nb (Fe-27.5 at.% Nb). In contrast, many planar faults parallel to the basal plane of the C14 structure were observed in Fe-rich Fe2Nb with Ni in solution, and the fault density increases with increasing Ni content up to 33.1 at.%. The high resolution transmission electron microscope (HRTEM) analysis revealed that the planar faults are related to the local change in the stacking sequence of the three 36-nets (triple layer) of the C14 structure. These results suggest that the presence of both, the point defects (Fe sublattice sites occupied by Ni atoms) and the anti-site defects (Nb sublattice sites occupied by excess Fe atoms), facilitate the formation of the planar faults.
Wireless Remote 2-D Strain Sensor using SAW Delay Line
Authors: Nomura Toru , Saitoh Atushi 
Published: August 2010

AbstractTwo-dimensional (2-D) strain sensor utilizing surface acoustic wave (SAW) devices is demonstrated. SAW devices offer many attractive features for applications as chemical and physical sensors. In this paper, a novel SAW strain sensor that employs SAW delay lines has been designed. Two crossed delay lines were used to measure the two-dimensional strain. A wireless sensing system is also proposed for effective operation of the strain sensor.
Study the Conduction Mechanism and the Electrical Response of Strained Nano-thin 3C-SiC Films on Si used as Surface Sensors
Authors: Rahimi Ronak , Miller Christopher M , Munger Alan , Raghavan Srikanth , Stinespring C D , Korakakis D 
Published: August 2010

AbstractVarious superior properties of SiC such as high thermal conductivity, chemical and thermal stability and mechanical robustness provide the basis for electronic and MEMS devices of novel design [1]. This work evaluates heterostructures that consist of a few nanometers-thick 3C-SiC films on silicon substrates. Nano-thin SiC films differ significantly in their electrical behavior compared to the bulk material [2], a finding that gives rise to a potential use of these films as surface sensors. To gain a better understanding of the effect of surface states on the electrical response of these thin, strained films, several metal-semiconductor-metal heterostructures have been examined under variable conditions. The nano-thin, strained films were grown using gas source molecular beam epitaxy. Reflection high-energy electron diffraction patterns obtained from several 3C-SiC films indicate that these films are strained nearly 3% relative to the SiC lattice constant. Al, Cr and Pt contacts to a nano-thin film 3C-SiC were deposited and characterized. I-V measurements of the strained nano-thin films demonstrate metal-semiconductor-metal characteristics. Band offsets due to biaxial tensile strain introduced within the 3C-SiC films were calculated and band diagrams incorporating strain effects were simulated. Electron affinity of 3C-SiC has been extracted from experimental I-V curves and is in good agreement with the value that has been calculated for a strained 3C-SiC film [3]. On the basis of experimental and simulation results, an empirical model for the current transport has been proposed. Fabricated devices have been characterized in a controlled environment under hydrogen flow and also in a reactive ambient, while heating the sample and oxidizing the surface, to investigate the effects of the environment on the surface states. Observed changes in I-V characteristics suggest that these nano-thin films can be used as surface sensors.
Degradation of Vertically Aligned Carbon Nanotubes at Growth Interface Joints at High Temperatures and Its Impact on Electron Emission Properties
Authors: Jin Feng , Liu Yan , Day Chris , Little Scott 
Published: August 2010

AbstractDegradation of carbon nanotubes (CNTs) significantly affects CNT's electron emission capability and limits their applications as electron emitters. In this study, CNTs were placed in controlled environment and their degradations were studied. Two types of CNT degradations, thermal and chemical degradations were identified and their effects on electron emission were studied. It was found that CNTs placed in low vacuum environment at high temperature were subject to oxidation that led to severe degradation of CNTs and their electron emission ability, whereas, CNTs treated at the same high temperatures in an ultrahigh vacuum environment only suffered from morphological changes that had minor impact on electron emission. The CNT samples used in this study were grown on tungsten substrates via plasma enhanced chemical vapor deposition (PE-CVD). The surface morphology changes of the CNT emitters were examined using scanning electron microscopy (SEM). The field emission properties of the CNTs were measured and correlated to the morphology changes.
High Yield and High Throughput Reactive IBAD MgO Process for Long-length, HTS Wire Production at SuperPower
Authors: Xiong Xuming , Zdun karol , Kim Sunjing , Rar Andrei , Sambandam Senthil , Schmidt Robert , Chen Yimin , Lenseth Kenneth , Selvamanickam Venkat 
Published: August 2010

AbstractSuperPower's IBAD (ion beam assisted deposition) MgO process has been changed to reactive ion beam sputtering of Mg metal target instead of MgO ceramic target, which gives ∼ 60 % increase in deposition rate. The process speed was increased from 195 m/h to 360 m/h. Texture of IBAD MgO tapes by this reactive process was found to degrade faster during long length run. This uniform issue was resolved with feedback control during long run and from run to run. The bottleneck of alumina layer process due to slow ion beam sputtering deposition was removed by new high rate reactive magnetron sputtering at transition mode. The new alumina process speed can be as high as 3,000 m/h in our Pilot Buffer system. The yttria layer process was also changed to high rate reactive magnetron sputtering at transition mode with achievable speed as high as 10,000 m/h in our Pilot Buffer system. The routine production speed of alumina and yttria is 750 m/h due to limitation of tape driving system. The high rate magnetron-sputtered alumina/yttria yields the same texture of IBAD MgO as ion beam sputtered alumina/yttria. Now we are routinely producing IBAD MgO template tapes of ∼ 1.4 km with a uniform in-plane texture ∼ 6-7 degrees. Record high critical current of 813 A/cm over a one meter length and a world record critical current times length value of > 233,8100A-m was obtained with our routinely-produced high throughput IBAD MgO buffers. The requirements for a better IBAD texturing layer than IBAD MgO are also suggested.