• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.203-206
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• 2004

For the realization of PRAM, $Ge_2Sb_2Te_5$ (GST) has been employed for the phase transition between the crystal and amorphous states by electrical joule heating. Although there has been a vast amount of results concerning the GST in material aspect for the laser-induced optical storage disc applications, the process-related issues of GST for the PRAM applications have not been reported. In this work, the etching behaviors of GST were investigated when the processing conditions were varied in the high-density helicon plasma. The etching parameters of RF main power, RF bias power, and chamber pressure were fixed at 600 W, 150 W, and 5 mTorr, respectively. For the etching processes, gas mixtures of $Ar/Cl_2$, $Ar/CF_4$, and $Ar/CHF_3$ were employed, in which the etching rates and etching selectivities of GST thin film in given gas mixtures were evaluated. From obtained results, it is found that we can arbitrarily design the etching process according to given cell structures and material combinations for PRAM cell fabrications.

• KSBB Journal
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• v.17 no.6
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• pp.571-576
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• 2002

Recombinant E. coli DH5 ${\alpha}$/pSB311 was made by cloning the genes encoding bacterial luciferase and aldehyde substrate proteins from Photohabdus luminescense, to complement defects of Lumistox, which is normally used in bioassays to monitor toxic substances in water environmental systems. The conditions for stable light production by the recombinant strains were investigated with respect to cell growth stage, cell number, and buffer conditions. The optimum growth stage was a middle-exponential stage with an OD$_{660nm}$ value of 0.6-0.7. ADout 10$^{6}$-10$^{7}$ cells per test tube was optimum for stable light emission. The effect of buffer was not significant if an optimum viable cell number was maintained. The bioluminescence of the recombinant E. coli harboring the lux operon of Photohabdus luminescense was not affected by temperature, while the bioluminescence of Lumistox was temperature sensitive. The recombinant E. coli was more sensitive to heavy metals (Cd, Cu, Hg, Zn) than Lumistox, because it does not require high concentrations of NaCl in the buffer.

• The Korean Journal of Pharmacology
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• v.8 no.2
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• pp.49-54
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• 1972

The component and pharmacologic action on Dianthus sinensis L. were investigated as follows: 1) The components of Dianthus sinensis L. were suggested 8 kind of components by means of thin layer chromatography and paper chromatography. The one of them were suggested as a steroidal saponin by means of IR-spectrum and Liebermann-Burchard, Salkowiski, $SbCl_3$ reaction. 2) Sodium level in serum were reduced by administration of the sample to the rabbits, while in urine were elevated. 3) Blood sugar level of normal rabbits administered with sample, no significant variation were detected. 4) When the hyperglycemic rabbits treated with alloxan were administered sample, blood-sugar level were significantly decreased than control group.

• Solar Energy
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• v.8 no.2
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• pp.19-25
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• 1988

[ $SnO_2$ ] thin films have been deposited on the pyrex glasses and silicon wafers by CVD method. Tin oxide films had a good transmittance above 80% in the visible region and the lowest sheet resistance at $520^{\circ}C$. When the ratio of $SbCl_3$ was 2wt%. The optimum conditions were obtained at the oxidation time of 3 minutes in the case that Voc and Jsc were 0.40V and $33.5mA/cm^2$ respectively and the corresponding conversion efficiency was 6.07%.

• Journal of the Speleological Society of Korea
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• v.33 no.34
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• pp.7-22
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• 1993

본 연구에서는 단양지역에 분포한 석회암동굴계의 수질에 대한 주요 원소와 미량 원소 그리고 오염실태를 살펴보았다. 풍화물에 존재하는 미량 원소가 기반암보다 수 배 내지 수 백배 이상 부하되어 있었다. TSD와 EC 등은 화강암의 지하수 보다 높은 경향이 있었고 pH는 중성 내지 알칼리성이었다. Ca와 Mg은 기반암에서 용탈되어 지하수로 용존된 것으로 50ppm이상을 함유하고 있다. Fe과 K은 다른 주요 원소보다 현저히 낮은 경향이 있었다. 주요 음이온인 F$^{-}$ , Cl$^{-}$ , NO$_3$$^{-}$ , SO$_4$$^{-}$ 등은 환경기준치 보다도 현저히 낮은 상태이며, 따라서 오염이 안된 상태로 볼 수 있다. 미량 원소중 Al, Sr, Ba등이 높은 반면에 Co, Mo, Sb, Cs, W, Pb, U, Mn 등은 매우 극소량으로 존재하는 것으로 나타났다. 연구지역 중 온달굴, 고수굴, 천동, 노동 등지는 오염이 거의 안된 상태로 매우 양호한 편이나 천동굴은 관광객으로 인하여 일부 원소가 오염되어 있는 실정이다.

• Rapid Communication in Photoscience
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• v.3 no.4
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• pp.70-72
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• 2014

Visible-light irradiation of MeCN solution containing di(hydroxo)metallo(tetraphenyl)porphyrin complex $(tppM(OH)_2$: 1a; $M=Sb(V)^+Br^-$, 1b; $M=P(V)^+Cl^-$, 1c; M=Ge(IV)) and 2-mercaptoethanol (2-ME) as a substrate under aerated condition gave bis(2-hydroxyethyl)disulfide (2-HEDS) as an oxidative product of 2-ME. It is indicated that the oxidation of 2-ME should proceed with a photocatalytic process by 1, because the turn over number (TON) for the formation of 2-HEDS was over unit. The TON was determined to be 642 as a maximum value when 1a was used as a sensitizer. The formation of 2-HDES was extremely slow under argon atmosphere. The fluorescence of 1 was not quenched by 2-ME at all, and the free energy change (${\Delta}G$) with electron transfer (ET) from 2-ME to excited triplet state of $1(^31^*)$ was estimated as a negative value. The quenching rate constant ($k_r$) of $^31^*$ by 2-ME, obtained by the kinetics for the formation of 2-HEDS, strongly depends on ${\Delta}G$. These findings indicate that 1-sensitized oxidation was initiated by photoinduced ET from 2-ME to $^31^*$ to generate both radical cation of 2-ME ($2-ME^{+\bulle}$) and porphyrin radical anion ($1^{-\bulle}$), resulting that the formation of 2-HEDS can be proceeded by the dimerization of $2-ME^{+\bulle}$, and through a catalytic cycle due to returning to 1 by the ET from $1^{-\bulle}$ to molecular oxygen.

• The Korean Journal of Nuclear Medicine
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• v.23 no.1
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• pp.71-83
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• 1989

For the development of $^{99m}Tc-labelled$ antimony sulfide colloid and hydroxyethyl starch, various experiments such as preparation of colloid, control of the distribution of particle size, establishment of labelling conditions, determination of labelling yield and radiochemical purity, examination of stability, and organ imagings of rabbits etc. were carried out. 1) Antimony sulfide colloid was readily prepared by the reaction of aqueous solution of antimony potassium tartrate with hydrogen sulfide generated by treating ferrous sulfide with dilute sulfuric acid. The colloid could be stabilized by adding small amount of polyvinylpyrrolidone. 2) Electron microscopy analysis exhibited the distribution of colloid size in the range of $1\sim15nm$ with a major portion of 9 m. The colloid solution was sterilized by membrane filtration $(0.2{\mu}m)$ and then stored at $4^{\circ}C$. This sterilized colloid was so stable that it was usable at least for one year. 3) The antimony sulfide colloid was labelled by adding sodium $pertechnetate-^{99m}Tc$ solution to the reaction vial, followed by adding hydrochloric acid and then boiled for 30 min. The optimal pH of the reaction mixture was found to be in the range of $1.3\sim1.4$. Instant thin layer chromatography (ITLC) analysis showed high labelling yield of above 99.5%. This labelled colloid maintained high radio-chemical purity of above 99% until 10 hours after labelling. 4) Animal studies showed high uptake of $^{99m}Tc-Sb_2S_3$ colloid at lymph vessels and nodes indicating a suitable agent for lymphoscintigraphy. Satisfactory results were also abtained in other clinical studies. 5) Hydroxyethyl starch (HES $0.6\sim1.0%$) was labelled with $Na^{99m}TcO_4$ in the presence of $SnCl_2$ with high labelling yield of above 99.5%. The optimal pH of the reaction mixture was in the range of $1.8\sim2.0$. $^{99m}Tc-HES$ maintained high radiochemical purity of above 99% until 10 hours after labelling. 6) Animal studies showed that $^{99m}Tc-HES$ migrated more rapidly from the injection sites into the lymph vessels than $^{99m}Tc-Sb_2S_3$ colloid while less amount of the former was uptaken at lymph nodes than that of the latter. Similar phenomenon was also observed in other clinical studies. As a result, $^{99m}Tc-Sb_2S_3$ colloid was found to be more effective lymphoscintigraphic agent than $^{99m}Tc-HES$.

• Journal of Sensor Science and Technology
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• v.6 no.3
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• pp.207-213
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• 1997

A field effect transistor(FET) type dissolved carbon dioxide($pCO_{2}$) sensor with a double layer structure of hydrogel membrane and $CO_{2}$ gas permeable membrane was fabricated by utilizing a $H^{+}$ ion selective field effect transistor(pH-ISFET) with Ag/AgCl reference electrode as a base chip. Formation of hydrogel membrane with photo-crosslinkable PVA-SbQ or PVP-PVAc/photosensitizer system was not suitable with the photolithographic process. Furthermore, hydrogel membrane on pH-ISFET base chip could be fabricated by photolithographic method with the aid of N,N,N',N'-tetramethyl othylenediarnine(TED) as $O_{2}$ quencher without using polyester film as a $O_{2}$ blanket during UV irradiation process. Photosensitive urethane acrylate type oligomer was used as gas permeable membrane on top of hydrogel layer. The FET type $pCO_{2}$ sensor fabricated by photolithographic method showed good linearity (linear calibration curve) in the range of $10^{-3}{\sim}10^{0}\;mol/{\ell}$ of dissolved $CO_{2}$ in aqueous solution with high sensitivity.

• Journal of Environmental Impact Assessment
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• v.15 no.6
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• pp.425-433
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• 2006

Instrumental neutron activation analysis was used to measure the concentrations of 27 elements associated with respirable particulate matter (PM10) that were collected from the Third and Fourth Industrial Complex Area of Daejeon City. The distribution patterns of elements were clearly distinguished with their concentrations varying across more than four orders of magnitude. The mean for Al were recorded to be the highest value of 1,527 $ng/m^3$, while that for In showed the lowest value of 0.1 $ng/m^3$. If compared in terms of enrichment factors, it was found that certain elements (e.g., As, Br, Cl, Cr, I, In, Sb, Se, and Zn) are enriched in PM10 samples of the study site. The results of factor analysis indicated six factors with statistical significance, which may exert dominant controls on regulating the elemental concentration levels in the study area.

• Economic and Environmental Geology
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• v.31 no.1
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• pp.1-10
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• 1998

Copper mineralization of the Donghwa and Hwanghagsan mines was deposited in hydrothermal quartz veins which filled fissures in Cretacous sedimentary rocks. Ore minerals are pyrite, sphalerite, chalcopyrite, bornite, galena, wittichenite and unidentified Cu-Bi-Pb-Sb-S mineral. On the basis of salinities and homogenization temperatures for fluid inclusions, the Donghwa deposit was deposited from $300^{\circ}C$ to $220^{\circ}C$ with 2.5 to 0.2 wt.% eq. NaCl, and the Hwanghagsan deposits was deposited from $300^{\circ}C$ to $160^{\circ}C$ with 4.0 to 0.0 wt.% eq. NaCl. Evidence of boiling suggests pressure of 170 to 60 bar, these pressures correspond to 1700 m to 600 m. The ${\delta}^{34}S_{H_2S}$ values of the Donghwa deposit (4.8~7.4%) are higher than those of the Hwanghagsan deposit (3.5~4.5%), sulfur isotope compositions indicate that ore fluids partially reacted with meteoric water and wall-rock. Equilibrium thermodynamic interpretation indicates that the temperature versus $fs_2$ of the Donghwa deposit (> $420^{\circ}C$, $10^{-3.2}atm$) is higher condition than that of the Hwanghagsan deposit (> $290^{\circ}C$, $10^{-7.0}atm$). K-Ar ages for biotite granite and quartz porphyry in the study area are 64.7 Ma, and 60.9 Ma, reapectively. Mineralization age using sericite in the Donghwa deposits is 59.8 Ma. Therfore, Copper mineralization in the study area was associated with acidic igneous activity such as biotite granite or quartz porphyry.