• Journal of Dental Rehabilitation and Applied Science
• /
• v.33 no.2
• /
• pp.106-113
• /
• 2017

Purpose: The purpose of this study was to evaluate tissue dissolving capacity, antimicrobial effect of Hydroxyethylidene bisphosphonate (HEBP) interacting with sodium hypochlorite (NaOCl), Ethylenediaminetetraacetic acid (EDTA) as conventional endodontic irrigants and to determine tissue dissolving efficacy depended on temperature. Materials and Methods: A total of 80 bovine muscles were randomly distributed into 8 groups (n = 10). After their initial weights determined on a precision scale, the specimens in each group were immersed in the solutions for 5, 10 and 15 min and reweighted at each time period. Agar diffusion test inoculated with Enterococcus faecalis was performed for antimicrobial effect of each endodontic irrigants. Results: The ability to dissolve organic matter was greater in NaOCl group following NaOCl and HEBP mixture. Heated NaOCl ($40^{\circ}C$) and NaOCl/ HEBP mixture was greater tissue dissolving efficacy than room temperature ($25^{\circ}C$). Antimicrobial effect was greater and significant in the following order EDTA > EDTA + 1% NaOCl > $1%\;NaOCl{\geq}1%\;NaOCl$ + HEBP. Conclusion: HEBP as soft chelating agent does not disturb antimicrobial effect and less affected tissue dissolving efficacy as inherent properties of NaOCl. In the heated NaOCl/HEBP mixture analyzed, it dissolved more the organic matter than room temperature.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.04a
• /
• pp.247-248
• /
• 2005

중금속의 용해도에 미치는 지배요인 중에서 금속의 지화학적 phases, 용액의 pH 및 반응 시간 등이 중금속 원소의 용해에 미치는 영향을 규명하고자 하였다. 실험결과, 청양광산의 과거 광산사무실에 있었던 장소의 광미들은 탄산염광물을 함유하는 것으로 보이고 하천 둑에 땋여있는 광미들보다 산화작용이 더 많이 진행되어 있는 것으로 판단된다.

• Proceedings of the KSEEG Conference
• /
• 2003.04a
• /
• pp.57-60
• /
• 2003

광업활동이 중지된 후 적절한 조치없이 방치된 폐광석들은 보다 빠르게 풍화될 수 있는 환경에 접하게 된다. 황화광물이 풍화되면 중금속이 용해되어 주변의 지표수나 지하수 및 토양의 오염을 초래한다. 용해된 중금속 이온들은 물리화학적 환경변화가 야기되면 보다 안정한 상태로 침전, 공침 또는 흡착되어지게 될 것이다. 만약 침전된 2차광물들이 불용성 광물이거나, 산성환경에서 비교적 안정한 광물에 흡착되어 제거된 중금속이라면 자연적으로 발생하고 있는 화학반응을 통하여 자연정화가 일어난다고 할 수 있다. (중략)

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.396-399
• /
• 2004

산화환경에 노출된 폐광석에 포함되어 있는 황화광물은 산소와 물과의 화학반응을 통해 산화작용을 받게 되고, 이로 인하여 Fe, Mn, Pb, Zn, Cu 및 As등의 원소의 용해반응이 발생할 것으로 예상된다. 그러나 이와 같이 용해된 금속이온은 pH등 환경의 변화에 따라 2차광물(산화광물 및 황산염광물)로 침전되거나 흡착되어 수용액으로부터 제거되어 자연적으로 고정화 될 수 있다. 이처럼 황화광물의 산화작용에 의해 형성된 2차광물에 대한 광물학적 연구는 광산복원을 결정하는데 직접적인 지구화학적 자료로 활용될 수 있다. 삼산제일광산에 방치된 폐광석을 대상으로 XRD, SEM/EDS을 이용하여 광물학적 연구를 수행한 결과 침전과 공침, 흡착 등의 화학반응을 통하여 현재 고정화되고 있는 것이 확인되었다.

• Journal of the Speleological Society of Korea
• /
• no.86
• /
• pp.1-7
• /
• 2008

지질구조는 카르스트의 층위와 구조상의 배열에 있어서 다양한 카르스트의 지형을 결정한다. 카르스트의 발달은 조산 및 조륙운동, 석회암층의 두께, 구성물질의 유형, 단층 및 습곡의 다양성, 주향 및 절리면의 빈도, 기후변화 및 기상환경, 수문 및 유수의 유형, 토지이용 현황 외 환경오염 등에 따라서 차별성을 나타낸다. 특히 지질구조에 따른 카르스트의 발달은 석회암 등이 유수의 작용에 커다란 용해작용의 영향을 받으므로 지질구조의 요인인 단층과 습곡현황과 절리와 균열 등에 의한 카르스트의 발달에 가장 큰 기여를 한다. 지질구조에 의하여 카르스트 지표지형에는 karren과 hum, mogotes, doline와 uvala, towers, springs, 구조적 유역, Closed Systems 등이 형성되고, 지하지형에는 Phreatic 동굴, Vados 동굴, Chambers, Multileveling cavities, Vertical shafts 등이 형성되는 다양성을 가진다. 한반도에서는 습곡구조에 의한 동공의 발달이 탁월하며, 다단계 및 급사면형 동굴의 유형이 다양하게 분포되고 있다.

• Journal of the Mineralogical Society of Korea
• /
• v.13 no.3
• /
• pp.121-137
• /
• 2000

Weathering profiles which were developed under a temperate, humid environment and relatively steep geography, show a thick saprolite and soil horiaon in the Precambrian granitic gneiss of the Yoogoo area. In the weathering profiles, secondary minerals such as interstratified biotite/vermiculite, tri- or di-octahedral vermiculite, halloysite, kaolinite, illite, smectite, gibsite and geothite were observed. Kaolinization of biotite is the most prevalent mechanism but vermiculitization is a minor from all ofweathering profiles. Biotite altered to B/V mixed layer-vermiculite, to illite and to halloysite, kaolinite and gibbsite. Halloysite is the most frequently observed weathering product of biotite in these profiles. Goethite is observed at the around or opened fissures of altered biotite. Tubular halloysite aggregates was fDrmed from dissolution-precipitation of plagioclase. The occurrence of halloysite aggregates is divided into a preferentially oriented type and a wrinkled one which were resulted from the dissolved type of plagioclase. Fe-bearing minerals have also been subjected to dissolution leaving the precipitation of geothite along dissolution voids. The profile of granitic gneiss is a typical weathering pattern showing a clay minerals increase toward the surface. Weathering of minerals were controlled by locally acidic and good-drainage environment, and formed a various and complicated secondary minerals in this study area.

• Journal of Korea Soil Environment Society
• /
• v.5 no.3
• /
• pp.55-64
• /
• 2001

Many organochlorine pesticides are persistent in the environment and have a tendency to bioaccumulate significantly through food chains. Aquatic environments are particularly more affected because the pesticides applied to agriculture systems are eventually carried into water bodies, through surface runoff, rivers, and groundwater flow. The objective of this paper is to study the effect of the coexistence of a heavy metal on the solubility enhancement of the two representative organochlorine pesticides, lindane and dieldrin, by humic acids. The solubility enhancement of pesticides by humic acid in a single system was compared with that in a binary system. The extent of solubility enhancement of lindane by humic acids was constant. while that of dieldrin by humic acids increased. Also, the solubility enhancement of dieldrin by humic acid with Pb decreased than that by humic acid without Pb.

• Proceedings of the Korean Fiber Society Conference
• /
• 1996.10a
• /
• pp.478-483
• /
• 1996

다관능성 에폭사이드 PPE(Polyglycerol Polyglycidyl Ether)를 양모섬유에 처리하였을 때 부가반응의 특성을 고찰하였다. 에폭사이드 PPE에 의한 부가반응이 촉매작용을 하는 NaSCN 존재하에서 이관능성 EGDE보다 높은 부가율을 얻을 수 있었다. 에폭사이드 부가반응은 고온에서 반응이 잘 일어나며 에폭사이드 처리욕의 pH는 반응 초기 급격히 상승했다가 이후 점차 초기 값까지 안정화된다. 처리한 양모섬유를 FTIR의 KBr-pellet법과 ATR법에 의해 분석하여 absorbance ratio를 비교하였을 때 부가반응은 표면으로의 그라프트 반응이 우세함을 알 수 있었으며 이러한 결과는 SEM 관측을 통하여 확인할 수 있었다. Performic acid/Ammonia solubility를 에폭사이드 처리 양모섬유에 적용하여 용해도 변화를 보았을 때 부가된 양이 많을수록 용해도 값이 감소하며 특히 15.6%를 중심으로 용해도 변화가 둔화되었다. 아미노산 분석으로 에폭사이드가 반응한 아미노산이 cystine임을 알 수 있었으며 단백질 사슬간에 가교반응이 이루어졌음을 확인할 수 있었다.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.40 no.2
• /
• pp.163-170
• /
• 2014

Lipid membranes composed of phosphatidylcholine (PC) are used in biophysical study to mimic cellular membranes and interactions between the membrane and chemicals, where organics solvents are used in dissolving lipids or chemicals. Later, solvents are removed from the solution under nitrogen gas at room temperature, followed by the further removal of the solvent at vacuum condition for several hours. In this process, some solvents are easily removed under described conditions above and others are required more severe conditions. In this study, $^{31}P$ solid-state nuclear magnetic resonance (SSNMR) techniques and differential scanning calorimetry (DSC) were used to see any changes in the line shapes of $^{31}P$ NMR spectra of multilamellar vesicles (MLVs) samples of POPC and in the phase change temperature of multilamellar vesicles (MLVs) of DPPC in DSC thermogram with or without any residual solvents. The thermodynamic parameters associated with the solvents did exhibit noticeable changes depending on solvent types. Thus, it is concluded that solvents should be carefully chosen and removed completely and experimental results should also be interpreted with caution particularly for the experiments investigating lipid phase changes and related topics.

• Korean Journal of Food Science and Technology
• /
• v.19 no.2
• /
• pp.89-96
• /
• 1987

The denaturation mechanism of the protein during heating of myosin and paramyosin extracted from the ordinary muscle of yellowtail (Seriola qrinqueradits) and the adductor muscle of whelk (Neptunea arthritica cuming) were investigated by analyzing the hydrophobicity, solubility, SH group and protein-protein interaction. The free hydrophobic residue of the two proteins were increased by increase of heating temperature up to $65^{\circ}C$ and then decreased for further temperature raise. The protein-protein interaction was proportional to the increment of the free hydrophobic residue. The aggregation of protein was begun from $65^{\circ}C$ with the decrease of the free hydrophobic residues. The results of Arrhenius equation for the data on proteinprotein interaction showed that the denaturation course was made up with multi-steps in the myosin and two-steps in the paramyosin. The number of free hydrophobic residue and SH group, solubility and protein-protein interaction were significantly differed with the denaturation temperature (p<0.01).