• Journal of the Korean GEO-environmental Society
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• v.13 no.12
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• pp.75-79
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• 2012

In the recycling of industrial waste unlike household waste, the legislation and the governmental systematic support, etc. were not also established due to an anxiety of hazard or harmfulness, etc. and a preconception. So the legislation and the system should be urgently established for the recycling of industrial waste. In this study, the environmental analyzing method of industrial waste-mixed coal ash in ash pond to recycle as a construction material is suggested by considering and analyzing test process and results about environmental impact factors of mixed coal ash. It is certified that there are not environmental problems in the recycling of mixed coal ash in ash pond as a construction material, according as its classification is general waste and each corresponding item of the leaching test result are satisfied with the 'environmental safety criteria' suggested in this study. And to build database, it is necessary to survey the environmental impact on surrounding areas with time after its recycling as a construction material.

• Applied Chemistry for Engineering
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• v.17 no.3
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• pp.317-320
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• 2006

The optimum mobile phase condition for analysis of the six purine derivatives (caffeine, guanine, hypoxanthine, purine, theobromine, and theophylline) were determined by a HCI program. Reversed-phase HPLC system was used with the binary mobile phase, water and methanol. Three retention models (Snyder, Langmuir, and Binary polynomial) were considered to predict the retention factors. The elution profiles were calculated by the plate theory based on the binary polynomial retention model. From the final calculated results, the binary polynomial retention model showed the best agreements between the calculated and experimental data. In the isocratic mode, the optimum mobile phase composition of water/methanol is 93/7(v/v). However, we used step-gradient mode to decrease the run-time ($1^{st}$ mobile phase : water/methanol = 93/7 (v/v), gradient time : 5 min, $2^{nd}$ mobile phase : water/methanol = 75/25 (v/v)). The experimental and simulated profiles of above the two conditions show a good agreement.

• Journal of Biomedical Engineering Research
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• v.25 no.1
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• pp.11-19
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• 2004

Stage 1 sleep provides important information regarding interpretation of nocturnal polysomnography, particularly sleep onset. It is a short transition period from wakeful consciousness to sleep. Lack of prominent sleep events characterizing stage 1 sleep is a major obstacle in automatic sleep stage scoring. In this study, we attempted to utilize simultaneous EEC and EOG processing and analyses to detect stage 1 sleep automatically. Relative powers of the alpha waves and the theta waves were calculated from spectral estimation. Either the relative power of alpha waves less than 50％ or the relative power of theta waves more than 23％ was regarded as stage 1 sleep. SEM (slow eye movement) was defined as the duration of both eye movement ranging from 1.5 to 4 seconds and regarded also as stage 1 sleep. If one of these three criteria was met, the epoch was regarded as stage 1 sleep. Results f ere compared to the manual rating results done by two polysomnography experts. Total of 169 epochs was analyzed. Agreement rate for stage 1 sleep between automatic detection and manual scoring was 79.3％ and Cohen's Kappa was 0.586 (p＜0.01). A significant portion (32％) of automatically detected stage 1 sleep included SEM. Generally, digitally-scored sleep s1aging shows the accuracy up to 70％. Considering potential difficulties in stage 1 sleep scoring, the accuracy of 79.3％ in this study seems to be robust enough. Simultaneous analysis of EOG provides differential value to the present study from previous oneswhich mainly depended on EEG analysis. The issue of close relationship between SEM and stage 1 sleep raised by Kinnariet at. remains to be a valid one in this study.

• Korean Journal of Plant Resources
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• v.15 no.2
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• pp.164-171
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• 2002

Morphological characteristics and growth pattern of 10 Polygonatum collections indigenous to Korea were examined to select the promising medicinal, edible resources and horticultural crops. Plant heights of I0 collections ranged from 15 to 102cm. Stem type was ascending or erect, and node numbers per a stem was 6.2 to 23.2. Phyllotaxis type was alternate or verticillate, and leaf shape was elliptical or linear. Leave numbers per a stem was 5.2 to 63.4, and bract types were classified into bracteate and nonbracteate. Flowers bloomed from May 7 to May 30, and flowering period was 5 to 13 days. Inflorescence types were classified into racemose, corymbose, and umbellate. Flower numbers per a stem was 1.5 to 125.2, and flower length was 13.1 to 30.2㎜. Perianth shapes were classified into tubular, constrict and urceolate. Surface colors of rhizome were pale yellow, pale brown, brown, and dark brown. As a result of this experiment, P. sibiricum, P. odoratum var. pluriflorum and P. odoratum var. thunbergii were thought to be useful as the medicinal and edible resources plants. On the other hand, P. odoratum var. pluriflorum 'Variegata', and P. odoratum var. maximowiczii, P. lasianthum. P. involucratum, P. desoulavyi, P. humile, and P. inflatum were thought to be useful as horticultural plants.

• Analytical Science and Technology
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• v.29 no.5
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• pp.219-224
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• 2016

불산 중 극미량 음이온의 고상추출과 이온크로마토그래프를 이용한 고감도 분석법이 개발되었다. 불산 중 불소이온이 고상에 의해 제거하였고 이어서 음이온 (F⁻, CH₃COO⁻, Cl⁻, Br⁻, NO₃⁻, PO₄³⁻, SO₄²⁻)들이 이온크로마토그래프를 이용하여 연속적으로 분리하였다. 고상 추출법에 영향을 주는 각 인자들 (흡착제의 선택, 시료의 부피 및 pH, 용출 용액과 용출용액의 부피)을 결정하였으며 그 결과 흡착제로서 Oasis WAX 컬럼이 가장 우수하였고 1.0 mL의 시료부피, 용출용액으로 50 mM 초산암모늄염 5 mL가 분리능에서 가장 우수하였다. 개발한 방법에 의한 음이온 (Cl⁻, Br⁻, NO₃⁻, PO₄³⁻, SO₄²⁻)들의 방법검출한계는 25 % 불산용액 (w/w) 중에 0.04~0.30 µg/L의 범위를 보였고 정밀도는 20.0와 40.0 µg/L의 농도에서 5 % 이내를 보였다. 한 제조회사에 의한 25 % 불산 중 음이온의 4.2에서 47.5 µg/L의 범위로 모두 검출되었다. 이 방법은 시험절차가 간단하고, 재현성 및 감도가 좋아서 반도체회사에서 불산 중 음이온 불순물을 정도 관리하는데 매우 유용한 방법이 될 것으로 판단된다.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.352-355
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• 2012

산성광산배수(Acid Mine Drainage)는 낮은 pH, 높은 Sulfate, 상대적으로 높은 Fe, Al, Mn 등의 중금속 농도가 특징으로 다양한 오염인자를 가지고 있으며, 각각의 오염인자가 오염에 미치는 영향이 매우 다양하게 나타난다. 특히 산성광산배수는 유역 내 시각적, 생태학적 문제를 일으켜 많은 환경오염을 야기하고 있으며, 많은 중금속을 용출시켜 주변 하천의 생태계를 파괴하게 된다. 이러한 산성광산 배수에 의한 환경피해의 심각성은 이미 국 내외에서 널리 인식되고 있으며, 이를 효과적으로 관리하기 위해서 산성광산배수의 거동 매커니즘 조사에 대한 연구가 필요하다. 따라서 본 연구에서는 금강수계 거풍광산 유역 장연천을 대상으로 하여 광산주변 표토, 계절별 거리별 하천수 및 저질토에서의 오염특성을 조사하고 그 영향을 평가하고자 하였다. 연구결과 하천수의 경우 대부분의 중금속 농도가 오염물질의 축적이 가장 많을 것으로 예상되는 5월에 높은 농도를 보였으며, 강우가 시작되는 6월, 7월까지 건기에 비해 높은 농도를 유지하다가, 강우가 지속됨에 따라 희석되어 농도가 감소되는 현상을 나타냈다. 저질토의 경우도 비슷한 양상을 타나냈다. 거리별 영향의 경우 하천수는 산성광산배수가 유입되는 상류에서 지속적으로 높은 농도를 나타냈으나, 저질토의 경우 건기에는 비슷한 양상을 나타내다가 우기에 강우의 영향으로 하천 하류에서 전체적으로 농도가 높아지는 경향을 나타냈다.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.183-186
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• 1992

Jindo Hongju is a traditional liquor in Korea. The characteristic of Hongju are its unique flavour and red color which is extracted from the root of gromwell (Lithospermum erythrorhizon). It is due to these color and flavour that Hongju attracts visual charm. However, the commercial value of Hongju is reduced because of the discoloration of red pigment during storage. Therefore, factors which cause the discoloration of red pigment and methods to prevent discoloration were investigated. The results obtained from this study are summarized as follows. The factors that cause the discoloration were visible light, temperature (beyond $40^{\circ}C$), pH (above 10) and inorganic ion ($Cu^{2-}$). Among all the additives added, Cystein (100 ppm) was the most effective inhibitor of pigment discoloration.

• Korean Chemical Engineering Research
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• v.44 no.6
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• pp.555-562
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• 2006

Recently, liquid chromatography (LC) has been used more frequently to separate drugs and natural substances. Especially, to selection of the solutes from the products, the operation condition of analytical chromatography should be necessarily determined. So accurate computer modeling and simulation of chromatographic performances has become a necessary part of the development and design of processes. High-Purity Separation Lab. Inha University developed the resulting HCI software for the purpose of the optimization of chromatographic performances. The HCI program was utilized to find the optimum operating condition more accurately and rapidly, reducing the number of many possible experiments. The elution profiles were calculated by the plate theory based on the three retention mechanism of capacity factor.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.2
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• pp.9-25
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• 2020

In 2010 and 2015, total 77 surface sediment samples were collected to assess the anthropogenic effects of trace metals in surface sediments of Garolim Bay, and the physical characteristics (particle size and specific surface area) and geochemical components (major (Al, Ca, Fe, K, Ba) and trace metals (Mn, Cs, Cr, Co, Ni, Cu, Zn, Pb), organic carbon and calcium carbonate) were analyzed. Mean grain size of Garolim Bay surface sediments ranged from 0.51-5.58 Ø (mean 3.98 Ø) and increased from the inlet of bay to the inner bay, and from the waterway to the land. Most of the metal concentrations except for some elements showed the similar distribution to those of mean grain size and specific surface area. As the particle size decreased and the specific surface area increased, the metal concentration increased. In order to estimate the factors controlling the concentration of trace metals, factor analysis was performed, and three factors were extracted (92.7% of the total variation). Factor 1 accounted for 71.3% of the total variation, which was a grain size factor. Factor 2 accounted for 14.2% of the total variation, Factor 3 accounted for 7.2% of the total variance. Enrichment factor was calculated using the particle size corrected background concentration. Metals with a enrichment factor of 1.5 or higher and the number of samples were 4 for Cr (St. 1, 16, 27, 39) and 1 for Pb (St. 39), but there were little differences in the concentrations of 1M HCl leached metals for these metals. The percentage of 1M HCl leached fraction to total metal concentration decreased in the order of Pb~Co>Cu>Zn~Mn>Ni>Cr. Comparing this value with contaminated and clean sediments in other coastal areas, the percentages for each metal were similar regardless of the trace metal levels in all regions. This fact might be resulted from the reaction between the 1M HCl solution and the different sediment constituents, indicating that there is a limit to apply this percentage of leached metal to the estimation of the contamination extent.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.456-463
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• 1996

The purpose of the present study is to estimate the regional and seasonal variations of dissolved inorganic nitrogen (DIN) flux across the sediment-water interface of the inner and central areas of Hiroshima Bay from August 1994 to May 1995. In addition it compares the measured methods and estimates the effect of DIN released from sediment to the primary production of Hiroshima Bay. One method used in this study is to calculate DIN flux from a concentration gradient between sediment porewaters and the overlying water, and the other method is to measure DIN flux from the sediment-core experiment. The fluxes of $NH_{4}^{+}-N\;and\;NO_{2}^{+}\;+\;NO_{3}^{-}-N$ in the inner area were higher than those in central area, all of which showed seasonal variation. $NH_{4}^{+}-N$ flux was maximum in August, while $NO_{2}^{-}\;+\;NO_{3}^{-}-N$ flux was high in January compared with the other seasons. The calculated $NH_{4}^{+}-N\;and\;NO_{2}^{-}+NO_{3}^{-}-N$ fluxes from sediments were $18.2\~60.8\;{\mu}g-at/m^2{\cdot}hr\;and\;0.24\~18.2\;{\mu}g-at/m^2{\cdot}hr$, respectively. The measured $NH_{4}^{+}-N\;and\;NO_{2}^{-}+NO_{3}^{-}-N$ fluxes across the sediment-water interface were $2.00\~111\;{\mu}g-at/m^2{\cdot}hr\;and\;-265\~82.9\;{\mu}g-at/m^2{\cdot}hr$, respectively. The former was lower than the tatter. The calculated $NH_{4}^{+}-N$ flux showed closer relation to environmental factors (dissolved of gen in the overlying water, temperature and redox condition of the sediments) than the measured one did. On the other hand, in the case of $NO_{2}^{-}+NO_{3}^{-}-N$ flux both the calculated and the measured showed little relation to environmental factors, while they turned out to have stronger relation with their concentration in sediments. DIN released from the sediment is expected to support about $25\%\~67\%$ of the primary production in Hiroshima Bay.