2004, Vol.14, No.2

Journal of the Korean Crystal Growth and Crystal Technology 2023 KCI Impact Factor : 0.19

pISSN : 1225-1429 / eISSN : 2234-5078
https://journal.kci.go.kr/jkcgct

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

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.

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.