• Journal of the Korean Ceramic Society
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• v.14 no.1
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• pp.7-11
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• 1977

Domestic Anyang feldspar was treated in autoclave with 1N sodium hydroxide solution for 1-6 hrs at 100-20$0^{\circ}C$ By X-ray diffraction patterns and cation exchange capacity, the products were examined. The following concecutive reaction was valid. AlbitelongrightarrowAmorphous aluminosilicatelongrightarrowAnalcime The reaction rate constants, k1 and k2, were 0.20 and 0.15(1/hr) at 20$0^{\circ}C$ respectively. The activiation energy from albite to amorphous aluminosilicate was 10 kcal/mol, and from amorphous aluminosilicate to analcine 13 kcal/mol. The analcime obtained was excellent in cation exchange capacity, amounting to 210meq./100g.

• Journal of the Korean Ceramic Society
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• v.16 no.2
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• pp.99-105
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• 1979

Themogravimetric analysis was used to investigate the kinetics of the $Si_3N_4$ formation from Korean rice hulls in the temperature range from $1990^{\circ}C$ to $1370^{\circ}C$. The experimental results indicated that the reaction rate controlling step in the overall process is the diffusion of CO gas from the surface of carbon particle to main body of $N_2$ gas fluid through the stagnant gas film around the carbon particle. The kinetics followed a nearly linear rate law at the initil reaction stage. The activiation energy for the formation of $Si_3N_4$ from Korean rice hulls was 43.5Kcal/mole.

• Journal of the Korean institute of surface engineering
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• v.21 no.4
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• pp.160-167
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• 1988

Electrochemical behaviors od chromium electrodeposition from 0.05M chromium (III) sulface complexes in aqueous solutions using sodium formate-glycine mixtures as a complexing agent were studied. In the cathodic current-potential cures, it is found that the intial limiting current of Cr(III) is proportional to square root of scan rate and activiation energy from Arrhenius plot is s obtained 3.05Kcal/mol. From this results, the reaction is considered, Cr3++e longrightarrow Cr2+, which is controlled diffusion of Cr (III). It is also found that the chromium is deposited when the potential reaches to hydrogen evolution potential. Effects of NaSCN as a catalyser in the electrolyte were investigated NCS- anion seems to react strongly by specific absorption at the inner HelmholtZ layer, so that, it is considered to suppress the electrodeposition reaction reaction for chromjum, and also it is considered multipe-bridge such as Cr(III)-NCS---M(M;cathode).

• Korea Trade Review
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• v.47 no.4
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• pp.293-309
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• 2022

The purpose of this paper is to analyze the import and export volume of Jeollabuk-do to establish a plan to activiation Saemangeum New Port. To this end, this study utilized the HHI(Herfindahl-Hirschman Index), LQ(Location Quotient) analysis using the annual data set from the Korea Trade Statistics Promotion Institution between 2015 to 2020. As a result, it has been confirmed that the degree of export volume concentration (HHI (Herfindahl-Hirschman Index)) in Jeollabuk-do has been increasing over the past 5 years. According to results of LQ(Location Quotient) analysis, Brazil had the highest index in the case of exporting countries, and Meat, edible meat offal (HS 2) had the highest index in the case of export items. This paper is meaningful in analyzing the export structure using import and export volumes and proposing a plan to improve the competitiveness of Saemangeum New Port.

• Journal of Environmental Health Sciences
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• v.17 no.1
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• pp.120-128
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• 1991

Saccharomyces cerevisiae was immobilized by incubating iron oxides with calcium alginate, and by polyacrylamide entrapment to use repeatedly for the conversion of glucose to ethanol. Magnetic and non-magnetic immobilized yeast and polyacrylamide immobilized yeast were compared with the native yeast a batch-fermentation of ethanol from glucose. Three kinds of immobilized yeast tended almost identically, having ethanol productivity as well as the final yield about the same to what was found for the native yeast. The long-term operational stability of three kinds of immobilized yeast were significant difference according as immobilized yeast activation or non-activation before ethanol fermentation. In the non-activation they lost their activity of fermentation rapidly in the beginning stage an slower at a later stage. On the other hand, in the activation with nutrient media, their activities were increased to some extent and stable in the later stage. The cell count of three kinds of immobilized yeast after activiation by incubating nutrient media, increased by a factor of about 45 to 48, whereas the fermenting capacity increased by a factor of 174 to 178. In the prearation of immobilized biocatalysts, magnetic matter does not seem to have any adverse affect on the properties of the microorganism. The immobilized biocatalysts by utilizing magnetic matter have some advantages, especially in application of viscous media or insoluble particle-containing media, for this work was linked with microbial utilization of environmental wastes and elimination of envirnmental pollutant.

• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.66-70
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• 2005

For the application in HI decomposition reaction of thermochemical water-splitting IS process, the carbonized membranes using the polymer material (polyimide) were prepared, and SiC membrane was also prepared by SiO treatment on those carbonized membranes. The weight change by the carbonation of polyimide was about 50%, and the weight decreased with an increase of carbonation temperature. The gas permeance ($H_2$ or $N_2$) of carbonized membrane decreased with an increase of carbonation temperature led to the pore closing. The gas permeance ($H_2$ or $N_2$) of SiC membrane increased with an increase of SiO treatment concentration, and the gas permeation mechanism was changed from the activiation energy flow to Knudsen flow.

• Bulletin of the Korean Chemical Society
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• v.8 no.5
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• pp.372-376
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• 1987

Acetone solution of quinoline-8-carbaldehyde reacts with $[Rh(cod)(PPh_3)_2] PF_6$and $[Ir(cod)(PPh_3)_2] PF_6$ to yield $[Rh(NC_9H_6CO)(H)(PPh_3)_2(CH_3COCH_3)] PF_6$ (1) and $[Ir(NC_9H_6CO)(H)(PPh_3)_2(CH_3COCH_3)] PF_6$ (2), respectively. The compound $[Ir(cod)(PPh_3)_2] PF_6$ also reacts with $Ph_2PC_6H_4-o-CHO$ in the acetone / $H_2O$ mixture to give $[Ir(Ph_2PC_6H_4-o-CO)(H)(PPh_3)_2(CH_3COCH_3)] PF_6$ (3). Compounds 1, 2, and 3 were characterized by infrared, $^1H$ NMR, $^{31}P$ NMR spectra and conductivity measurement. The $^1H$ NMR spectra of 1, 2, and 3 support the presence of a terminal hydride that is cis to the phosphine. The IR band of 3 at 2185 $cm^{-1}$, which is assigned to $\nu$(Ir-H), and the hydride cleavage reaction of 3 with $CCl_4$, provide evidence for the Ir-H bond.

• New & Renewable Energy
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• v.3 no.4
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• pp.63-68
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• 2007

유리를 기판으로 하는 superstrate pin 비정질 실리콘 태양전진에서 전면 투명전도막(TCO)과 p-층의 계면은 태양전지 변환효율에 큰 영향을 미친다. 면투명전도막(TCO)으로 현재 일반적으로 사용되는 ZnO:Al는 $SnO_2:F$보다 전기, 광학적으로 우수하고, 안개율 (Haze)높으며, 수소 플라즈마에서 안정성이 높은 특징을 갖고 있다. 그래서 박막 태양전지의 특성향상에 매우 유리하나, 태양전지로 제조했을 때, $SnO_2$보다 충진율(Fill Factor:F.F)과 $V_{oc}$가 감소한다는 단점을 가지고 있다. 본 실험실에서는 $SnO_2:F$dml F.F.가 72%이 나온 반면 ZnO:Al의 F.F은 68%에 그쳤다. 이들 원인을 분석하기 위해 TCO/p-layer의 전기적 특성을 알아 본 결과, $SnO_2:F$보다 ZnO:Al의 직렬저항이 높게 측정되었다. 이러한 결과를 바탕으로 p-layer에 $R=(H_2/SiH_4)=25$로 변화, p ${\mu}c$-Si:H/p a-SiC:H로 p-layer 이중 증착, p-layer의 boron doping 농도를 증가시키는 실험을 하였다. 직렬저항이 가장 낮았던 p ${\mu}c$-Si:H/p a-SiC:H 인 p-layer 이중 증착에서 $V_{oc}$는 0.95V F.F는 70%이상이 나왔다. 이들 각 p층의 $E_a$(Activiation Energy)를 구해본 결과, ${\mu}c$-Si:H의 Ea 가 가장 낮은 것을 관찰 할 수 있었다.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.295-299
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• 1995

This study was conducted to find the control methods, status of overwintering and seasonal occurrence of Erioccoccus largerstroemiae on persimmon trees in Ch'ondo area, Kyongbuk province in Korea. Usually, overwintering eggs were sheltered in bark, among them the rate of alive eggs was 28.7%. The activiation of garpe-myrtle scale showed from late April, and they have three generations per year. The first occurrence of larval stage of Erioccoccus largerstroemiae starts from late June to early July, the second occurrence begins from middle August to late August, and from late June to early July, the second occurrence begins from middle August to late August, and from middle September to late September is the third, thus, three peaks of occurrence revealed in early July middle August, and late September respectively. Average number of eggs conceived in female adult was 229.3. Spray effect of chemical control showed as follows; lime sulfur with tow applications of pesticides (late June, late August) at 97.8%, machine oil with tow applications of pesticides (late June, late August) at 96.8%. And during the growing period, the spray results using three applications of pesticide only (late June, late August, amid September) showed 77.2% in field condition.

• Journal of Embryo Transfer
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• v.15 no.1
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• pp.23-31
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• 2000

This study was conducted to investigate the effects of quiescent treatment of donor cells and activation treatment time of recipient cytoplasm on nuclear remodeling and in vitro development of somatic cell-cloned bovine embryos. Serum starved, confluent and nonquiescent cycling adult skin cells were teansferred into enucleated oocytes. Nuclear transfer oocytes were activated at 30 min, 1 and 2 hrs after electrofusion. Some nuclear transfer embryos(23% to 35%) extruded a polar body, which was not affected by quiescent treatment of donor cells and activiation time of recipient cytoplasm. About 68% of nuclear transfer embryos fused with a serum starved cells has a chromatin clump, but which was not different from embryos fused with confluent(51%) and nonquiescent(47%) cells. The proportion of embryos with a single chromatin clump was sightly increased when nuclear transfer embryos were activated within 30 min after fusion(69%) compared to those were activated at 1 and 2 hrs after fusion, but there was not significantly different. Development rates to the blastocyst stage were 8.6% and 15.9% when serum starved and confluent cells were transferred, which were higher than that of control group. Developmental rate to the blastocyst stage was higher in embryos were activated within 30 min after fusion (17.3%) compared to those of embryos were activated at 1 and 2 hrs after fusion (P<0.05). From the present result, it is suggested that quiescent treatment of donor cells and activation time of recipient cytoplasm can affect the in vitro development. Quiescent plasm activation within 30 min after fusion could increase the number of embryos with a normal chromation structure, which results in increased in vitro development.