Structural and photocatalytic properties of TiO_2 films fabricated on silicon substrates by MOCVD method

Silicon(111) and Silicon(100) were employed for fabrication of TiO 2 films by metal organic chemical vapor deposition(MOCVD). Titanium(IV) isopropoxide(Ti[O(C 3H 7) 4]) was used as a precursor. The as deposited TiO 2 films were characterized with FE\|SEM, XRD and AFM. The photocatalytic properties were investigated by decomposition of aqueous OrangeⅡ. And UV VIS photospectrometer was used for checking the absorption characteristics and photocatalytic degradation activity. The crystalline and structural properties of TiO 2 film had crucial influences on the photodegradation efficiency. For MOCVD in situ deposited films on Si substrates, the photoactivities varied following a shape of “M': at lower(350℃), middle(500℃) and higher(800℃) temperature of deposition, relative lower photodegradation activities were observed. At 400℃ and 700℃ of deposition, relative higher efficiencies of degradation were obtained, because one predominant crystallite orientation could be obtained as deposition at the temperature of two levels, especially a single anatase crystalline TiO 2 film could be obtained at 700℃.

Molecular Phenotyping by Proteomic Pattern Analysis in Arabidopsis thaliana

We are conducting a large scale functional analysis of plant genes utilizing the promoter trap lines and proteomic analyses as a part of the Crop functional genomics research program of Korea. Here, I describe the progresses we have made during last 2.5 years and a future plan.

Fabrication and Photocatalytic Characteristics of TiO_2 Films on Silicon Substrates

Silicon (111) and Silicon (100) have been employed for fabrication of TiO_2films by metal organic chemical vapor deposition (MOCVD). Titanium (IV) isopropoxide (Ti[O(C_3H_7)_4]) was used as a precursor. The as-deposited TiO_2 films have been characterized withField emission scanning electron microscopy (FE-SEM), X ray diffraction (XRD) and atomic forcemicroscopy (AFM). The photocatalytic properties were investigated by decomposition of aqueous orangeII. The crystalline and structural propertiesof TiO_2 film had crucial influences on thephotodegradation efficiency. For MOCVD in-situ deposited films on Si substrates, the photoactivitiesvaried following a shape of 'M': At lower (350 °C ) middle (500 °C) and higher (800 °C)temperature of deposition, relative lower photodegradation activities have been observed. At 400 °Cand 700 'C of deposition, relative higher efficiencies of degradation have been obtained, becauseone predominant crystallite orientation could be obtained as deposition at those two temperatures,especially a single anatase crystalline TiO_2 film could be obtained at 700 °C growth.

ESTIMATES OF LOWER CRITICAL MAGNETICFIELD AND VORTEX PINNING BY INHOMO-GENEITIES IN TYPE II SUPERCONDUCTORS

The effect of an applied magnetic field on an inhomogeneous superconductor is studied and the value of the lower critical magnetic field HC1 at which superconducting vortices appear is estimated. In addition, the authors locate the vortices of local minimizers, which depends on the inhomogeneous term a(x).

ESTIMATE OF THE UPPER CRITICAL FIELD AND CONCENTRATION FOR SUPERCONDUCTOR

The effect of an applied magnetic field on an inhomogeneous superconductor is studied and the value of the upper critical magnetic field Hc3 at which superconductivity can nucleate is estimated. In addition, the authors locate the concentration of the order parameter, which depends on the inhomogeneous term a(x). Unlikely to the homogeneous case, the order parameter may concentrate in the interior of the superconducting material, due to the influence of the inhomogeneous term a(x).

s-REGULAR DIHEDRAL COVERINGS OF THE COMPLETE GRAPH OF ORDER 4

A graph is s-regular if its automorphism group acts regularly on the set of its s-arcs. An infinite family of cubic 1-regular graphs was constructed in [7] as cyclic coverings of the three-dimensional Hypercube, and a classification of all s-regular cyclic coverings of the complete bipartite graph of order 6 was given in [8] for each s ≥ 1, whose fibre-preserving automorphism subgroups act arc-transitively. In this paper, the authors classify all s-regular dihedral coverings of the complete graph of order 4 for each s ≥ 1, whose fibre-preserving automorphism subgroups act arc-transitively. As a result, a new infinite family of cubic 1-regular graphs is constructed.

On the Stabilizer of the Automorphism Group of a 4-valent Vertex-transitive Graph with Odd-prime-power Order

Abstract Let X be a 4-valent connected vertex-transitive graph with odd-prime-power order p^k (kS1), and let A be the full automorphism group of X. In this paper, we prove that the stabilizer Av of a vertex v in A is a 2-group if p p 5, or a {2,3}-group if p = 5. Furthermore, if p = 5 |Av| is not divisible by 3^2. As a result, we show that any 4-valent connected vertex-transitive graph with odd-prime-power order p^k (kS1) is at most 1-arc-transitive for p p 5 and 2-arc-transitive for p = 5.