• Journal of Environmental Science International
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• v.10 no.6
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• pp.387-391
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• 2001

The hydroxyapatite(HAp) as a carrier the for ion exchange agent of $Ag^+$ions was prepared in semiconductor fabrication, The Ca/P molar ratio of the HAp was 1.65. The HAp is molded in shape of the antimcrobial ball and then sintered at 100$0^{\circ}C$ Ag-containing HAp(HAp-Ag) was prepared by incorporating $Ag^+$/ions in HAp crystals through an ion-exchange reaction in solutions containing 0.01M $AgNO_3$. The antimicrobial effect of HAp-Ag for bacteria such as Escherichial coli and Staphylococcus aureus has been Investigated. The concentrations of silver in the antimicrobial ball was determined by inductively coupled plasma and the amount of $Ag^+$ions was 9.0$\mu\textrm{g}$/g. The HAp-Ag exhibited excellent antimicrobial effect for bacteria such as E. coli and S. aureus. The bactericidal activity was considered to be caused by direct contact of bacteria with $Ag^+$ions in the HAp crystals. The HAp would likely to be possible as a carrier of antimicrobial metal ions such as Ag, Cu, and Zn by recycling of waste sludge in the semiconductor fabrication process.

• 한국석유지질학회:학술대회논문집
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• spring
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• pp.48-55
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• 1998

The Pohang Basin is located in Pohang City and adjacent coastal areas in the southeastern Korea. It has a sequence of 900 meters of Neogene marine sediments (Yeonil Group) while offshore basins in the East Sea, e.g., the Ulleng basin, is over 10 Km in thickness. An understanding of the marine Yeonil Group in the Pohang Basin may provide insights into the hydrocarbon potential of the offshore East Sea regions. Heulandite, smectite, dolomite, kaolinite and opal-CT are commonly found as diagenetic minerals in the Yeonil Group. Among these minerals, heulandite occurs as a main cement only in sandstones consisting of volcanic matrix, Smectite composition and diagenetic mineral facies such as heulandite and opal-CT may reflect that the Yeonil Group has undergone shallow burial, temperatures below about 60 degrees. This suggest that sandstones have experiened weak diagenetic alteration. In order to reconstruct the thermal history of the basin, apatite fission-track analysis was carried out. Aapparent apatite fission-track ages (AFTAs) exhibit a broader range of ages from 238 Ma to 27 Ma with mean track lengths in the range of $15.24\pm8.0$ micrometers, indicating that these samples had undergone significant predepositional thermal alteration. The Triassic to Cretaceous AFTAs seem In represent the timing of cooling of their sedimentary sources. Late Cretaceous mean AFTA $(79.0\pm8.0 Ma)$ on the Neogene Yeonil Group indicates that the Yeonil Group had not been buried deeper than 2km since its deposition. The organic matters of. the Pohang Basin remain in the immature stage of thermal evolution because burial depth and temperature were not sufficient enough for maturation even in the deep section of the basin.

• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.13.2-13.2
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• 2011

뼈의 역학기능을 예측하는 인자(predictive factor) 로서 골밀도(BMD)만으로는 충분하지 않다는 최근의 임상결과는, 골밀도 이외의 새로운 뼈의 강도 및 골절리스크를 지배하는 인자의 중요성을 보여준다. 이와 같은 골역학기능에 대한 골밀도 이외의 부가적인 지배인자를 골질(bone quality)이라고 하는데, 다양한 골질관련인자(bone quality-related factor) 중 하나의 지표로서 뼈의 주성분인 생체아파타이트(BAp)의 결정학적 방향성에 주목, 대표적인 경조직 질환을 해석하였다. 파골세포결손에 의해 대리석증을 유발하는 op/op마우스는 골밀도의 변화뿐만 아니라, 골질의 유의한 변화가 있었다. 즉, 이와 같은 결과는 파골세포결손에 의한 조골세포의 활성저하의 의해 골질이 저하됨을 시사하는 결과이며, 파골세포 과잉의 의해 골다공증을 유발하는 OPG-KO마우스는 골밀도가 급격히 저하됨과 동시에, BAp배향성도 급격히 낮아졌다. 즉, 골대사회전의 상승에 따른 섬유성골(woven bone)의 형성에 의해 BAp의 결정성장이 억제되며, 그 결과 BAp배향성이 저하된다고 사료된다. 이상, 본 연구에서는 대표적인 골 질환조직을 각각의 정상골과 비교함으로써, 골양(BMD)의 변화뿐만 아니라 골질(BAp배향성)의 변화를 발견하였다. 이와 같은 변화는 골질지표로서 BAp배향성이 유효하다는 것을 강하게 시사한다. 따라서 본 연구에 의해 얻어진 견해는 경조직 질환의 병리해명에 적용 가능함과 동시에, 경조직 질환의 진단 응용이나 치료약 개발, 임플란트 개발 등 폭넓은 분야에 유용하다고 할 수 있다.

• Journal of the Korean Society of Safety
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• v.17 no.1
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• pp.72-78
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• 2002

Among the disposal techniques of inorganic wastewater sludges from industries most of sludges were dealed with buring underground inefficiently. But we have tried to recycle the resources that exhausted inorganic sludges were properly blended to certain ratioes to make lightweight aggregate, that means manufacturing of it can be possible through blending of various components, drying, sintering, cooling and crushing to certain sizes that are needed by consumers. As disposal method of inorganic wastewater sludge is changed to environmentally fraternative method, this method could be very useful to make lightweight aggregates for decoration of building and the other so many purposes of those usages. That could be economically useful due to expected income for buring costs of ordinary disposal method form industries and sales income after manufacturing it. The second important profit is saving foreign currency from purchasing self-developed lightweight aggregate insteas of importing expensive foreign product. This product will be also very impressive to user because of the fraternative lightweight to be composed of apatite structure that is important part of human body.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.2
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• pp.23-34
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• 1991

Even if we can recover the function of mastication, pronunciation and esthetic using the fixed or removable prosthesis in the loss of teeth or hard tissue in the oral cavity, we use several kinds of implants in order to solve the problem which can be occured when we can't install the denture because of excessive bone resolution or psychlogical affairs. At present Titanium implant plays a major role in this field and has osseointegrated. And the study on the modern material is going on, that result in developing and using the implant which is coated with HA, bone induced material. In this, I studied histologically the change of the bone tissue which is occured when three kinds of HA coated implants. Such as Integral, Sustain, Biovent implanted into mandible of dog and got a 8-weeks healing period. I got the conclusion as follows: 1. Most of the implant which is covered with serveral kinds of HA coating implant in bone after 8 weeks being implanted and has osseointegrated, partially converted into the connective tissue. 2. Biovent formed the connective tissue in the perforated area of inferior alveolar canal and has osseointegrated.

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.190-199
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• 1991

The purpose of this study was to evaluate the antimicrobial effect of root canal cements such as AH-26, Sealapex, Canals and Apatite root sealers(Type I, II, III) and to determine the efficacy of their activities. S.mutans(AHT), S.sanguis(NCTC 9811) and B.gingivalis(381) were streaked on blood agar and the PVC tybes filled with root canal cements were applied on. Then the microorganisms were cultured for 48 hours, anaerobically. B.cereus(KCTC 1012) was streaked on nutrient agar, PVC tubes were applied on and were cultured for 48 hours, aerobically. The inhibition zones of root canal cements were measured with vernier caliper. The data statistically analyzed, and the results were as followed. 1. Apatite root sealers(Type I, II, III) showed no inhibition zones. 2. AH-26, Sealapex and Canals had inhibition zones with varying degrees. The inhibition zone of AH-26 was greatest and followed by Canals and Sealapex(P<0.01). 3. As time goes by after mixing the root canal cements, AH-26, Canals and Sealapex showed significantly reducing inhibition zones(P<0.01). 4. There were the least inhibition zones of all the root canal cements on S.mutans and followed in such order as; B.gingivalis, S.sanguis and B.cereus(P<0.01).

• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.3950-3956
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• 2012

In order to improve the bioactivity and mechanical properties of hydroxyapatite (HAp), chitosan (Chi) was in situ combined into HAp to fabricate a composite scaffold by a sublimation-assisted compression method. A highly porous film with sufficient mechanical strength was prepared and the bioactivity was investigated by examining the apatite formed on the scaffolds incubated in simulated body fluid. In addition, the cytotoxicity of the HAp/Chi composite was studied by evaluating the viability of murine fibroblasts (L-929 cells) exposed to diluted extracts of the composite films. The apatite layer was assessed using scanning electronic microscopy, inductively coupled plasma-optical emission spectrometry and weight measurement. Composite analysis showed that a layer of micro-sized, needle-like crystals was formed on the surface of the composite film. Additionally, the WST-8 assay after L-929 cells were exposed to diluted extracts of the composite indicated that the HAp/Chi scaffold has good in vitro cytocompatibility. The results indicated that HAp/Chi composites with porous structure are promising scaffolding materials for bone-patch engineering because their porous morphology can provide an environment conductive to attachment and growth of osteoblasts and osteogenic cells.

• The Korean Journal of Ceramics
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• v.5 no.2
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• pp.162-164
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• 1999

Microsotructure designed porous ceramics of calcium hydroxyapatite $(Ca_{10}(PO_4)_6(OH)_2)$ were prepared by hydrothermal method. The particle size, shape, and the micro-pore size of the porous hydroxyapatite ceramics could becontrolled. The hydroxyapatite was non-stoichiometric apatite with calcium deficient compositions (Ca/P ratio < 1.67). The composition of non-stoichiometric hydroxyapatite ceramics could be controlled from 1.50 to 1.63 in Ca/P ratio. The hydroxyapatite ceramics preparedc at $105^{\circ}C$ under the saturated vapor pressure for 20h were composed of rod-shaped crystals with about 10$\mu\textrm{m}$ in length with the mean aspect ratio of 40. The porous ceramics of calcium deficient hydroxyapatite had about 45% porosity with the inter-connecting pore structure. Porous hydroxyapatite ceramics prepared hydrothermally had the compressive strength of about 10 to 30 MPa. In addition, porous ceramics of $\beta$-tricalcium phosphate ($\beta-Ca_3(PO_4)_2$) were prepared from the calcium deficient hydroxyapatite.

• Journal of Biosystems Engineering
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• v.29 no.4
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• pp.347-356
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• 2004

치아인회석, 키토산, 시아노아크릴레이트 등의 생분해성 생체재료를 이용해 새로운 생체흡수성 골시멘트를 개발하고자 하였다. 이들 골시멘트들에 대해서 중합온도, 응고시간 등의 조작특성과 압축강도, 전단강도 등의 물성을 분석하였다. 특히, 치아인회석과 키토산의 미립가루와 부틸 시아노아크릴레이트의 강력접착제를 이용한 시멘트(B)에 대해서는 직접 접촉방법과 XTT 방법을 통해 세포독성을 분석하였고, 또한 쥐를 이용한 동물실험에서 시멘트(B)의 처리그룹에 따라 생체적합성을 분석하였다. 시아노아크릴레이트를 이용한 골시멘트의 최대중합온도는 약 33$^{\circ}C$, 조작(응고)시간은 3-6분, 압축강도는 약 15-25㎫, 전단강도는 약 0.4-l.7 ㎫를 나타내었다. 첨가제로 사용된 Lipiodol은 골시멘트의 주사성과 강력접착제의 초기 중합지연도를 높였고, 특히 송진가루는 시아노아크릴레이트의 초기중합을 지연시켰다. 시아노아크릴레이트를 이용한 시멘트(B)의 세포독성을 분석한 결과, 대부분의 처리 그룹에서 낮게 나타났고, 특히 키토산과 치아인회석을 사용한 경우 각각 세포 독성이 더 낮게 나타났다. 그리고 골시멘트(B)의 동물 생체적합성 실험의 방사선상 및 조직학적 분석에서도 뼈 형성 및 결합이 우수하게 나타났다.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2452-2463
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• 2018

Surface treatment of sol-gel bioglass is required to increase its biomedical applications. In this study, a dielectric barrier discharge (DBD) plasma treatment in atmospheric pressure was performed on the surface of [$SiO_2-CaO-P_2O_5-B_2O_3$] sol-gel derived glass. The obtained bioglass was treated by plasma using discharge current 12 mA with an exposure period for 30 min. The type of discharge can be characterized by measuring the discharge current and applied potential waveform and the power dissipation. Apatite formation on the surface of the DBD-treated and untreated samples after soaking in simulated body fluid (SBF) at $37^{\circ}C$ is characterized by Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), inductively coupled plasma (ICP-OES) and scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). We observed a marked increase in the amount of apatite deposited on the surface of the treated plasma samples than those of the untreated ones, indicating that DBD plasma treatment is an efficient method and capable of modifying the surface of glass beside effectively transforming it into highly bioactive materials.