5,254 research outputs found
Surface electronic properties of Na/Ge(111)-3x1
No full textThe electronic properties of Na overlayers on Ge(111) are investigated using ultraviolet photoemission spectroscopy. Adsorption of Na atoms on Ge(111)-c(2 x 8) and Na/Ge(111)-3 x 1 surfaces does not change the semiconducting surface property. The Na/Ge(111)-3 x 1 surface is characterized using photoemission of adsorbed xenon. The local work function measurement shows that there are two different sites in (3 x 1) surface. One is close to Na atoms and its local work function is 0.48 eV lower than that of the other site. This Na-induced short range interacting area is about 33% of total surface, which indicates that the Na coverage of the (3 x 1) phase is about 1/3 ML.Financial supports have partially been provided by the center for molecular science. One of us (J.M Seo) was supported by the basic science research institute program, Ministry of education, 1994, Project No. BSRI-94-2433
Angle-resolved photoemission of InSb(111)-2x2
No full textThe electronic band structure of InSb(111) along the Gamma-Lambda-L[111] direction was determined using angle-resolved photoemission spectroscopy for the photon energy between 9 and 39 eV via synchrotron radiation. The bulk band dispersion is in agreement with earlier theoretical calculations. The In- (group III-) terminated InSb(111) surface shows surface Umklapp transitions and reflection of the bulk density of states. We found two nondispersive features which were not reported before. They are related to the surface state and the resonance process of the InSb(111)-2 x 2.Financial
support was partially provided by the Centre for Molecular Science and the Pohang Light
Source. One of us (J M Seo) was supported by the Basic Science Research Institute
Programme, Ministry of Education, 1994, Project No BSRI-94-2433
Dynamic infinite elements for soil-structure interaction analysis in a layered soil medium
No full textThis paper presents the dynamic infinite element formulations that have been developed for soil-structure interaction analysis both in frequency domain and time domain by the present authors and our colleagues during the past 20 years. Axisymmetric, 2D and 3D layered half-space soil media were considered in the developments. The displacement shape functions of the infinite elements were established using approximate expressions of analytical solutions in frequency domain to represent the characteristics of multiple waves propagating into the unbounded outer domain of the media. The shape functions were determined in terms of the excitation frequency as well as the spatial and material characteristics of the far-field soil region. Thereby the element mass and stiffness matrices are frequency dependent. As for time domain analysis, the shape functions were further simplified to obtain closed-form frequency-dependent mass and stiffness matrices, which can analytically be transformed into time domain terms by the Fourier transform. The proposed infinite elements were verified using benchmark examples, which showed that the present formulations are very effective for the soil-structure interaction analysis either in frequency or in time domain. Example applications to actual soil-structure interaction problems are also given to demonstrate the capability and versatility of the present methodology
Reduction of gap states of ternary III-V semiconductor surfaces by sulfur passivation: Comparative studies of AlGaAs and InGaP
No full textThe effects of sulfur passivation on liquid-phase-epitaxy-grown n-type InGaP and AlGaAs surfaces have been studied using x-ray photoelectron spectroscopy. The surfaces were simultaneously prepared through degreasing and the use of an aqueous (NH4)(2)S-x treatment in air. For InGaP, sulfur atoms initially reacted with both surface In and Ga atoms and reacted negligibly with P atoms. The band bending was reduced by 0.7 eV compared to a sputter-cleaned surface. Presumably, sulfur eliminated P-vacancy-related gap states by occupying P sites and forming In-S and Ga-S bonds. By postheat treatment at 180 degrees C, S atoms were not removed from the surface and band bending was reduced further by 0.1 eV. For AlGaAs, S atoms initially reacted with Ga and As, but this treatment could not remove the Al oxide previously formed in the air. Postheat treatment at 180 degrees C simply induced S redistribution from As to Ga and As desorption, which reduced the band bending by 0.3 eV compared to the sputter-cleaned surface-a result similar to that for GaAs. (C) 1996 American Vacuum Society.The present studies were supported by the Basic Science
Research Institute program, Ministry of Education, 1994,
Project No. BSRI-94-2433. One of us ~S. K.! has been supported
by the Center for Molecular Science
Photoemission studies of the Na/Ge(111)-3x1 surface
No full textThe electronic structure of a Na/Ge(111)3 x 1 surface was investigated by valence-band and core-level photoemission spectroscopy with synchrotron radiation. The two-dimensional energy-band dispersion of the surface Brillouin zone along (M) over bar-<(Gamma)over bar>-(K) over bar was mapped out. The experimental surface-state dispersions show a better agreement with the theoretical results for the buckled Seiwatz model than the extended Pandey model. The surface core-level shift of the (3 x 1) surface is explained on the basis of the buckled Seiwatz model. The (3 x 1) surface reveals more covalent bonding character than other Na-adsorbed surfaces at room temperature, and its surface Fermi level is close to the valence-band maximum.Partial financial support was provided by the Centre for Molecular
Science and the Pohang Light Source. One of us (JMS) was supported by the Basic Science
Research Institute Programme, Ministry of Education, 1995, Project No BSRI-95-2433
Surface core-level shift of InSb(111)-2x2
No full textSurface core-level photoemission of InSb(111)-2x2 was performed using a synchrotron radiation light source. There were two surface components of the In 4d core level. A higher binding component of In 4d is attributed to the surface In bonded to Sb atoms. The lower binding component with smaller intensity is due to the surface In cluster atoms. On the other hand, we were not able to observe any surface components in the Sb 4d core level. This puzzling behavior is interpreted with a different contribution of surface and bulk Madelung potential to the surface core-level shifts in relation with the atomic geometry.Financial support has been partially
provided by the Center for Molecular Science and the Pohang
Light Source. One of us ~J. M. S.! was supported by the
Basic Science Research Institute Program, Ministry of Education,
1994, Project No. BSRI-94-2433
Performance of anode-supported SOFC single cells using thin electrolyte of YSZ and ScSZ at intermediate temperatures
No full textThe SSC of the Generalised Jahangir’s Graph Jm,k and its Algebraic Characterizations
No full textIn this article, we present important combinatorial and algebraicproperties of spanning simplicial complex (SSC) of the generalised Jahangir’sgraph Jm,k. We describe the relation to find f−vectors associatedto Δs(Jm,k) and determine the Hilbert series for the SR-ring KΔs(Jm,k).In the end, we present the associated primes of the facet ideal IF(Δs(Jm,k))and the Cohen-Macaulay characterization of the SR-ring of Δs(Jm,k).AMS (MOS) Subject Classification Codes: Primary 13-P10, Secondary 13-F20, 13-C14, 13-H10.Corresponding Author: Agha KashifKey Words: Simplicial Complexes, f-vectors, Spanning Trees, Face Ring, Hilbert Series, CohenMacaulay
To <i>JM</i> on Its 75th Anniversary
No full text This article discusses how Journal of Marketing ( JM) has influenced marketing science and practice by publishing articles on substantive topics relevant to customers, managers, organizations, markets, and society. The journal's 75th anniversary coincides with the 50th anniversary of the Marketing Science Institute (MSI). Frequently, JM and MSI have collaborated to address important substantive marketing issues identified in MSI's Research Priorities. The author highlights seminal articles on brand equity; business-to-business marketing (including sales force management); connecting marketing information, metrics, and strategy; consumer behavior; innovation, new product development. and product management; marketing orientation and capabilities; and market research, methodology and services. She also draws attention to articles that have won the Sheth Foundation/ JM Award and the H. Paul Root Award. The article describes how JM‘s knowledge dissemination is amplified by powerful social network effects. Ideas in JM articles diffuse through the business community, influencing the mind-set of managers worldwide. </jats:p
JM-20, a Benzodiazepine-Dihydropyridine Hybrid Molecule, Inhibits the Formation of Alpha-Synuclein-Aggregated Species
No full text\ua9 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.Studies showed that JM-20, a benzodiazepine-dihydropyridine hybrid molecule, protects against rotenone and 6-hydroxydopamine neurotoxicity. However, its protective effects against cytotoxicity induced by endogenous neurotoxins involved in Parkinson’s disease (PD) pathogenesis have never been investigated. In this study, we evaluated the ability of JM-20 to inhibit alpha-synuclein (aSyn) aggregation. We also evaluated the interactions of JM-20 with aSyn by molecular docking and molecular dynamics and assessed the protective effect of JM-20 against aminochrome cytotoxicity. We demonstrated that JM-20 induced the formation of heterogeneous amyloid fibrils, which were innocuous to primary cultures of mesencephalic cells. Moreover, JM-20 reduced the average size of aSyn positive inclusions in H4 cells transfected with SynT wild-type and synphilin-1-V5, but not in HEK cells transfected with synphilin-1-GFP. In silico studies showed the interaction between JM-20 and the aSyn-binding site. Additionally, we showed that JM-20 protects SH-SY5Y cells against aminochrome cytotoxicity. These results reinforce the potential of JM-20 as a neuroprotective compound for PD and suggest aSyn as a molecular target for JM-20
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