Korean | English

pISSN : 1225-1429 / eISSN : 2234-5078

2020 KCI Impact Factor : 0.17
Home > Explore Content > All Issues > Article List

2004, Vol.14, No.2

  • 1.

    Adsorption properties and metal growth aspects on the surface of activated carbon monolith electrochemically deposited woth Ag

    Oh Won Chun | Chang Sung Lim | 2004, 14(2) | pp.37~46 | number of Cited : 0
    Abstract PDF
    The electrochemical adsorption of the Ag ions from aqueous solution on pelletized activated carbon monolith was investigated over wide range of operation time. The adsorption capacities of pelletized activated carbon monolith are associated with their internal porosity and are related properties such as surface area, pore size distribution. The chemical industry generates wastewater that contains toxic matters like heavy metals in small concentrations so that their economic recovery is not feasible. But, the method using activated carbon monolith can be used to withdrawal of heavy metals in waste water. After the electrochemical treatment, the quantitative properties in Ag ion solutions are also examined by pH concentration and studied elemental analysis by ICP-Atomic Emission Spectrometer and Energy Disperse X-ray (EDX) spectra. It is consider that the pH is very important factor at the reason of water pollutant with increasing acidity in industrial field. The result of quantitative analysis using Inductively Coupled Plasma-Atomic Emission Spectrometer of metal after electrochemical reaction in Ag ions solution depending on time are shown that the amount of Ag ions deposited was decreased with growth of Ag particles on the carbon surfaces as increasing electrochemically treated time. And, surface morphologies are investigated by scanning electron microscopy (SEM) to explain the changes in adsorption properties
  • 2.

    Impact of gate protection silicon nitride film on the sub-quarter micron transistor performances

    최준호 | 2004, 14(2) | pp.47~49 | number of Cited : 0
    Abstract PDF
    Gate protection SiNx as an alternative to a conventional re-oxidation proces in Dynamic Random AcesMemory devices is investigated. This process can not only protect the gate electrode tungsten against oxidation, but alsosave the thermal budget due to the re-oxidation. The protection SiNx process is applied to the poly-Si gate, and its deviceperformance is measured and compared with the re-oxidation processed poly-Si gate. The results on the gate dielectricintegrity show that etch damage-curing capability of protection SiNx is comparable to the re-oxidation process. In addition,the hot carrier immunity of the SiNx deposited gate is superior to that of re-oxidation procesed gate.
  • 3.

    Growth and characterization of lead bromide: application to mercurous bromide

    Geug-Tae Kim | 2004, 14(2) | pp.50~57 | number of Cited : 1
    Abstract PDF
    Mercurous Bromide (Hg2Br2) crystals hold promise for many acousto-optic and opto-electronic applications. Thismaterial is prepared in closed ampoules by the physical vapor transport (PVT) growth method. We investigate the effects ofsolutal convection the crystal growth rate in a horizontal configuration for difusive-convection conditions and purelydifusion conditions achievable in a low gravity environment. Our results show that the growth rate is decreased by a factorof one-fourth with a ten reduction of gravitational acceleration near y = 2.0 cm. For 0.1 g0, the growth rate pattern exhibitsrelatively flat which is intimately related to difusion-dominated processes. The growth rate nonuniformity is regardles ofaspect ratio across the interfacial positions from 0 to 1.5. Also, the effect of a factor of the ten reduction in thegravitational acceleration is same to both Ar = 5 and 2. The enlargement in the molecular weight of B from 50 to 500 bya factor 4 causes a decrease in the maximum growth rate by the same factor, indicative of the effect of solutal gradients.
  • 4.

    Effect of anisotropic diffusion coefficient on the evolution of the interface void in copper metallization for integrated circuits

    최준호 | 2004, 14(2) | pp.58~62 | number of Cited : 1
    Abstract PDF
    The shape evolution of the interface void of copper metalization for intergrated circuits under electromigrationstres is modeled. A 2-dimensional finite-diference numerical method is employed for computing time evolution of thevoid shape driven by surface difusion, and the electrostatic problem is solved by boundary element method. When thedifusion coefficient is isotropic, the numerical results agree wel with the known case of wedge-shape void evolution. Thenumerical results for the anisotropic difusion coefficient show that the initialy circular void evolves to become a fatal slit-like shape when the electron wind force is large, while the shape becomes non-fatal and circular as the electron wind forcedecreases. The results indicate that the open circuit failure caused by slit-like void shape is far less probable to be observedfor copper metalization under a normal electromigration stress condition.
  • 5.

    Structural change of cobalt dodecanesulfate

    Young Duk Huh | 권석순 | 김지현 | 2004, 14(2) | pp.63~67 | number of Cited : 0
    Abstract PDF
    The layered structure of cobalt dodecanesulfate was synthesized. A phase transition takes place at varioustemperature ranges and results in a drastic change of the layer distance. A monolayer structure of cobalt dodecanesulfate atrom temperature transformed to a bilayer structure as a dehydrated form at high temperature
  • 6.

    Melt growth and superconducting properties of Sm-doped YBCO super-conductor by zone melting method

    김소정 | 2004, 14(2) | pp.68~72 | number of Cited : 0
    Abstract PDF
    Sm-doped YBCO high Tc superconductor was directionaly grown by zone melt growth process in airatmosphere. Cylindrical green rods of (Sm/Y)1.8Ba2.4Cu3.4O7 - x[(Sm/Y)1.8] oxides were fabricated by cold isostatic pressing(CIP) method using ruber mold. Based on the variation of melting temperature and growth rate, the microstructure andsuperconducting properties were systematically measured by using optical micrographs, TEM and SQUID magnetometer. Inthis study, optimum melting temperature and growth rate were 1085oC and 3.5 mm/hr respectively. Nonsuperconducting(Sm/Y)2BaCuO5 inclusions of (Sm/Y)1.8 superconductor were uniformly distributed within the superconducting (Sm/Y)Ba2Cu3O7 - x matrix. The directionaly melt-textured (Sm/Y)1.8 superconductor showed an onset Tc 90 K and sharpsuperconducting transition.
  • 7.

    The color enhancement of natural Zambian amethyst by the hydrothermal treatment method

    박춘원 | KIM PAN CHAE | 2004, 14(2) | pp.73~77 | number of Cited : 2
    Abstract PDF
    The color enhancement for natural Zambian amethyst of low quality was carried out by the hydrothermaltreatment method. The hydrothermal treatment conditions were as folows: reaction temperature; 300oC, duration; 30 hrs,filing; 40 %, solvent; 6 M-HCl solution. The redish purple amethyst of high quality was obtained under these conditions.From the result of ICP/AES, it was known that color enhancement was affected by a Fe elemental content to exist in theinside of natural Zambian amethyst. Also, from the result of UV-VIS-NIR, it was shown that the absorption peak at50 nm after hydrothermal treatment is slightly lower than those of non-treated natural Zambian amethyst. In this study, itwas known that hydrothermal treatment method was a way to suitable for increase of commercial value of natural Zambianamethyst.
  • 8.

    The cultivation and characterization of imaged abalone pearls

    박라영 | KIM PAN CHAE | 2004, 14(2) | pp.78~81 | number of Cited : 0
    Abstract PDF
    The nacre of imaged abalone pearls was obtained as a calcium carbonate of aragonite type. This result wassame the nacre of natural abalone pearl. From the observation of SEM for the nacre adhered on the pearl nucleus, it wasknown that the layers of calcium carbonate and conchiolin were stratified. The growth rate of nacre was found to be0.0056~0.0074 mm/day, which is twice faster than that of traditional method used shells. The pendant and brooch weremanufactured using the imaged abalone pearls.