• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.2
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• pp.240-248
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• 1996

To clarify the potentiality of sea cucumbers as dietary food, the effects of those glycoprotein on dietary proteins and physicochemical properties of those proteins were studied. Crude glycoprotein was efficiently extracted using 20mM sodium phosphate beffer(pH 7.0) and by salting out with 80% ammoniym sulfate saturation. The fractions obtained through the DEAE-cellulose ion exchange chromatography was identified as glycoprotein by Schiff's reagent and SDS polyacrylanide gel electro-phoresis. The yields of each glycoprotein from the three kinds of sea cucumbers were 0.814(red), 0.184(blue) and 0.232(black) and the molecular weights of the glycoproteins subunits were ranged from 20,000 dalton(blue and black) to 29,000 dalton(red), respectively. The electrophoretic patterns of the glycoprotein isolates were similar to each other and any significant difference in amino acid pattern was observed. Predominant arnino scids were Asx(aspartic acid and asparagine) and Glx(glutamic acid and glutamine) ; in contrast, histidine and methionine were below 2% as compared to total amino acids. water holding capacities of the glycoprotein isolates from red, blue and black cucumbers were equally 100% and emulsion activities ranged from 53% to 64%. In addition the emulsion stabilities were 7.04, 1.37 and 2.44, respectively. In vitro digestibility of some proteins(casein, SPI and squid) was decreased as increasing the level of the freeze dried sea cucumber powder and glycoprotein isolates. But squid protein was not affected.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1999.10a
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• pp.433-435
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• 1999

대기 중에 존재하는 에어로졸은 물리ㆍ화학적인 반응에 의하여 생성되며 금속, 수용성 성분을 비롯한 탄소입자 등으로 복잡하게 이루어져 있다. 이들은 대기중에서 시정감소와 광산란을 야기시킬 뿐 아니라 인체에 흡입되어 호흡기질환등을 야기 시킨다(Holt,1988). 또한 분진은 입자의 크기가 작을수록 상대적으로 표면적이 증가하여 각종 유해 대기오염물질과 흡착하여 인체에 악영향을 미친다(Simpson, 1992; John et al., 1990).(중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.11a
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• pp.339-340
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• 2000

에어로졸의 장거리 이동에 대한 연구는 황사의 수송과 기상특성, 황사의 연직 구조 분석, 황사의 성분 및 변질 등 황사 에어로졸의 화학적ㆍ물리적ㆍ기상학적 분석을 통하여 시행되어 왔다. 최근에 들어 인공위성을 이용한 대기의 광학적 두께(aerosol optical depth) 및 황사 에어로졸의 장거리 이동에 대한 위성관측은 황사현상에 대한 발현 예보를 가능하게 하였다. 광주과학기술원 환경모니터링 신기술연구센터는 기상청의 예보를 토대로 비정규적 황사 현상에 대한 에어로졸의 광ㆍ화학적 장거리 이동특성을 조사하기 위하여 예상 황사기간에 시정집중모니터링을 실시하였다. (중략)

• Food Science and Preservation
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• v.10 no.4
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• pp.498-505
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• 2003

This was studied to evaluate the rheology properties of the Dumpling shell added chitosans(commercial and prepared from fungal), polyphosphate, guargum and tapioca. The physicochemical properties of fungal chitosans (FCs95 and FCs 40) were as follows respectively. The nitrogen was 6.71% and 6.9％, the solubility 99.05% and 99.13％, the viscosity 2.23cps and 2.21cps, the acetylation 12.0% and 12.7% and the molecular weight 3.12${\times}$10$\^$5/Dalton and 3.01${\times}$10$\^$5/Dalton. From the above facts, the components and physicochemical properties of two kinds of fungal chitosan had little difference. The addition of polyphosphate, guargum and tapioca showed effect on the texture parameters(hardness, cohesiveness, springiness and gumminess) of Dumpling shell dough and the optimum addition concentration wag 0.074%, 6.59% and 0.062%(w/w), respectively. In case of chiotsans addition, texture of the dough by added SCs, FCs95 and FCs40 showed effect.

• Journal of the Korean Electrochemical Society
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• v.10 no.4
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• pp.306-310
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• 2007

Characteristics of GDL (Gas Diffusion Layer) mainly determine the gas diffusion and water removal in a cell, thereby changing the performance and affecting durability of PEFC. To optimize the water management and understand the two phase flow in a GDL, it is important to study the behaviors of GDL micro structure under the real operating condition. In the clamped condition of cell, the GDL beneath the rib is more compressed than beneath the channel. Many researches on physical, electrochemical, mechanical behaviors of gas diffusion layer has been conducted. However, changes in surface properties under clamped condition have rarely studied. In present study, the morphology of broken connections of carbon fibers and detachment of PTFE coatings on the fibers were shown from the microscopic observations. In addition, changes in wetting properties of GDL by compression were investigated by using XPS and liquid uptake methods. The hydrophobic characteristics of GDL surface beneath the rib of the flow field plate are changed due to the deformation of micro structure.

• 한국문화재보존과학회:학술대회논문집
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• 2004.03a
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• pp.78-91
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• 2004

염(Salts)은 일반적으로 가장 강력한 풍화요인 물질 중 하나이다. 염의 결정화(crystallization) 및 수화(hydration)작용은 석재의 화학적 풍화 뿐만이 아니라 물리적 풍화를 가속화 시킨다. 감은사지 석탑은 오랜 세월 대기 중에 노출되어 대기환경오염으로 인한 화학적 풍화 뿐만이 아니라 지리적으로 바다에 인접해 있어 바다에서 기원한 염화나트륨(NaCl)의 영향으로 다른 석조물에 비해 심한 물리적 풍화현상을 보이고 있다. 편광 현미경 및 SEM, XRD, XRF를 이용하여 석탑의 구성석재 및 염(salts)에 대한분석을 실시하였으며, 용출실험을 통해 얻은 용액에 대해서는 IC와 ICP-AES를 이용하여 분석하였고, 염류와 석재의 반응산물로 만들어진 염에 대해서는 정방위시료와 부정방위시료를 제작하여 분석하였다. 감은사지 석탑을 이루는 암석은 결정응회암으로 주 구성 광물은 사장석 및 정장석이며 소량의 석영 및 흑운모 등이 함유되어 있고 소량의 유리질 석기로 구성되어 있다. 석재의 표면에는 주 구성 광물들의 화학적 풍화로 인해서 생성된 2차 광물로 팽창성 점토광물인 스멕타이트가 존재하며, 대기오염물질과의 결합에 의해 생성된 대표적인 황산염인 석고$(gypsum,\;CaSO_4{\cdot}2H_2O)$, 소금(halite, NaCl), 해양기원 염류인 소금성분과 대기오염물질이 만들어낸 테나다이트$(thenardite,\;Na_2SO_4)$가 존재한다. 이들 염류는 일차적으로 암석의 표면에 백화현상을 초래하기도 하고, 대기 중의 오염물질과 결합하여 일부는 흑화현상을 보이기도 한다. 또한 암석 내 수분이 증가할 경우 이들 염들이 암석의 공극이나 열극을 따라 내부로 이동하여 subflorescence를 발생시켜 박락 및 박탈의 원인이 되었으며, 온도와 수분의 변화에 따른 이들 염(salts)의 수화 및 결정 작용 그리고 새로운 염(salts)의 침전작용을 반복하면서 석재 내부와 외부의 암석 및 결정에 균열과 미세열극 등이 생성되어 석재 자체의 구조적 안정성에 영향을 주고 있다. 따라서 감은사지 석탑은 지리적 환경 차이로 인해 일반적인 환경의 석조물들과는 다른 형태의 풍화양상을 보이고 있어서 풍화양상 및 풍화형태에 대한 정확한 연구와 이해를 바탕으로 보존대책이 마련되어야 한다.

• The Korean Journal of Pesticide Science
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• v.7 no.1
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• pp.58-65
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• 2003

Various physicochemical parameters for the active ingredients of 245 herbicides were calculated to develope a diagnosis and estimation system for utility as herbicide. The range of physico-chemical parameters for each inhibitors of photo system II (H1), acetolactate synthase (ALS) (H2) and herbicides were confirmed. The distribution ranges of 85% dependence for each physicochemical parameters were Obs.logP :$-0.90\sim4.50$, dipol moment: $1.80\sim12.22$ (debye), molecular refractivity: $53.0\sim104.0(cm^3/mol)$, polarizability: $19.0\sim37.0(\AA^3)$, HOMO energy: $-9.98\sim-7.34$ (eV), LUMO energy:$-2.76\sim0.40$ (eV), Van der Waals molecular volumes: $558.0\sim995.0(cm^3)$, molecular weight: $202.0\sim430.0$ (amu) and surface areas (Grids): $194.0\sim356.0(\AA^2)$, hydration energy: $-10.16\sim114.7$ Kcal/mol, respectively. It is suggested that MR and polarizability constants will be able to distinguish between herbicides and medicinal drugs. Results revealed that various compounds based on the range of physicochemical parameters of herbicides could be diagnosed and estimated.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.754-760
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• 1999

The properties of the catalyst for a direct internal reforming type molten carbonate fuel cell were examined by ICP, BET, CHN, EDS, and $H_2$ chemisorption. Potassium and lithium, the components of carbonate electrolyte, were transported to the catalyst during the operation of fuel cell, and the amounts of the deposited alkali elements were reduced in the order of inlet, outlet, and the middle. From the direct correlation between the amount of alkali and the physical properties such as BET surface area and Ni dispersion, and from the observation of the lump of the alkali species on the poisoned catalyst, it was confirmed that the physical blocking of the catalyst by alkali deposition was the main reason for the deactivation. Although the amount of alkali species was greater at the inlet than at the oulet, the catalyst sampled from the outlet had lower activity. This was caused by the chemical interaction between the alkali species and the catalyst at the outlet where temperature was highest in the cell body, which was detected by FT-IR analyses.

• Journal of Ginseng Research
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• v.33 no.1
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• pp.13-25
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• 2009

Geochemical relationships between ginsengs and soils from three representative soil types, shale, phyllite and granite regions, from Keumsan were examined. High elements ere shown at the granite and shale areas of the weathered soils, the phyllite areas of he cultivated soils and the shale areas of the host rocks. T1 was enriched in ginsengs grown in the shale areas, Cs and B in the phyllite areas, and Be and Cd in the granite areas. Positive correlations were dominated by the shale areas. These relationships can be explained for mineral characteristics within the soils, and their behaviors related to the physio-chemical conditions. High elements were shown in the 2 year ginsengs of the hale areas, and 4 year ginsengs of the phyllite and granite areas in comparisons with ginsengs of the different ages from the same areas. These differences can be explained with ages of the ginsengs, solubilities of the minerals and physio-chemical differences within soils. The content differences of high elements such as Cs, T1 and Be were found between soils and ginsengs. Overall, these results suggest that components of ginsengs grown in the granite areas are chemically similar to the soils.

• Journal of the Korean Geosynthetics Society
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• v.5 no.2
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• pp.39-44
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• 2006

The resistance of flexible PVC geomembranes to leachate chemicals is an important factor when PVC geomembranes are being considered as a barrier layer in a composite liner system. This paper describes laboratory test results that evaluate the chemical compatibility of a 0.76 mm (30 mil) thick flexible PVC geomembrane exposed to a synthetic municipal solid waste (MSW) leachate. Changes in dimensional, physical, and mechanical properties were measured after exposure to the synthetic MSW leachate at $23^{\circ}C$ and $50^{\circ}C$ for 30, 60, 90, and 120 days. Although some variability of the test results is observed due to experimental factors and product variability, the synthetic MSW leachate did not significantly degrade the physical or mechanical properties of the flexible PVC geomembrane. As a result, this paper will conclude the PVC geomembranes are not adversely affected by the synthetic MSW leachate.