• 한국지구과학회지
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• 제23권1호
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• pp.52-58
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• 2002

A colorless and transparent zirconium oxide ($Zr_{0.73}Y_{0.27}O_{1.87}$) crystal has been synthesized by the Bridgman-Stockbager method. The gem-quality material is produced by adding 20${\sim}$25 wt.% $Y_2O_3$ (stabilizer) and 0.04 wt.% $Nd_2O_3$ (decolorising agent) to the $ZrO_2$ powder. It shows a vitreous luster with a slight oily appearance. Under a polarizing microscope, it shows isotropic nature with no appreciable anisotropism. Mohs hardness value and specific gravity is measured to be 8${\sim}$$8{\frac{1}{2}}$ and 5.85, respectively. Under ultraviolet light it shows a faint white glow. The crystal structure of yttria-stabilized zirconia with 0.27 at.% Y has been re-investigated, using single crystal X-ray diffraction, and confirmed to be a cubic symmetry, space group $Fm{\overline{3}}m$ ($O^5_h$) with a=5.1552(5) ${{\AA}}$, V=136.99(5) ${{\AA}}^3$, Z=4. The stabilizer atoms randomly occupy the zirconium sites and there are displacements of oxygen atoms with amplitudes of ${\Delta}/a{\sim}$0.033 and 0.11 along <110> and <111> from the ideal positions of the fluorite structure, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 추계학술대회 논문집
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• pp.73-76
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• 1992

The amorphous phase of bulk and thin film in the As-Se-S-Ge system was observed by X-ray diffraction. Thermal analysis using DSC, DTA and TGA method has been used for the determination of the glass transition temperature, Tg. The glass transition temperature, Tg for the composition were $238^{\circ}C$ in $As_{40}Se_{15}S_{35}Ge_{10}$ and $231^{\circ}C$ in $AS_{40}Se_{25}S_{25}Ge_{10}$ and $As_{40}Se_{50}Ge_{10}$. The phase seperation of continuous phase and dispersive phase was observed by the optical texture of the polarizing microscope. Also, the glass transition temperature of the thin film was near $200^{\circ}C$. As the results of SEM-EDS analysis, the phase transition of the films by thermal treatment and light illumination was the amorphous to amorphous.

• 보존과학연구
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• 통권16호
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• pp.123-128
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• 1995

For establishing the plan of scientific conservation on the Kyongch′onsa and site of Won-gaksa 10 floors pagodas, the investigation on the rocks consisting these pagodas has been made on the rock phase and weathering characteristics. The Kyongch′onsa pagoda consists of fine grained pale graylimestone containing abundant fossils of shell and fragments of organisms. The site of Won-gaksa pagoda is composed of marble of pale gray, white and/or light brown color, which is intercalated with thin mica schist. The marble, the recrystallized limestone, consists mainly of recrystallized calcite accompanied with minor amount of muscovite. Especially carbonate rocks are somewhat different in chemical weathering from such granitic rocks. The field survey and laboratory experiment using polarizing microscope had been done during 30 days from Feb, 13 to March, 31, 1995. The rocks equivalent to that of the site of Kyongch′onsa were identified from the Myobong limestone formation and taken samples around the road from P′yongch′ang to Mitan, P′yongch′ang-gun. The rocks similar to that of the site of Won-gaksa pagoda were distributed around Pan-un-ri, Chunch′on-myon, Yong-wol-gun. The rocks of the Silluksa pagoda consisting of white recrystallized limestone with banded structure are similar to the marble of the Hyangsan-riformation distributed around Suanbo, Ch′ungch′ongbuk-do.

• 박물관보존과학
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• 제17권
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• pp.85-100
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• 2016

경북대학교박물관에서 소장하고 있는 봉화 북지리 석조반가상은 국립중앙박물관 특별전 '고대불교조각대전 <불상, 간다라에서 서라벌까지>'의 전시를 위해 운송과정을 거쳐 보존처리를 수행하였다. 석조반가상에는 표면에 오염물, 입상분해, 균열 등이 발생한 상태였으며 특히, 하단부가 사선으로 파손되어 단독으로 세울 수 없었으므로 전시 시 직립 안정성을 확보하기 위한 받침대를 제작하였다. 또한 암석의 구성광물을 동정하고 오염물을 확인하기 위해 편광현미경 및 실체현미경 관찰, SEM-EDS분석을 실시하였다. 그 결과, 봉화 북지리 석조반가상은 흑운모 화강암으로 구성된 것을 확인하였다. 새로 제작한 받침대에 원형의 우레탄수지로 만든 봉을 여러 군데 박아 넣었고 이에 대한 마찰력 실험으로 받침대 안정성을 평가하였다. 우레탄수지 및 에폭시수지의 마찰력 비교실험에서는 에폭시수지보다 우레탄수지가 높은 마찰계수 결과를 나타냈다. 따라서 봉화 북지리 석조반가상은 우레탄봉을 사용한 받침대를 받침으로써 보다 안정적인 전시가 가능하였다.

• 치과방사선
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• 제26권2호
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• pp.33-44
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• 1996

This study was for comparing healing patterns and effects between with odontogenic and nonodontogenic tissues on the defected mandible. Experimental bone defects that measured 3 mm in diameter were created on the mandibular body of guinea pig by removal of bone with the use of trephine burs and bone defects were grafted with Biogran(Orthovita Co., U.S.A.) and covered with Dura Mata(Pfrimmer-Viggo GmbH Co., Germany). Guinea pigs were serially terminated by fours on the 3 days, the 1 week, the 2 weeks, the 3 weeks, the 4 weeks, and the 5 weeks after experiment, and the mandibular body was removed and fixed with 10％ neutral formalin. They were decalcified and embedded in paraffin as using the usual methods. The specimen sectioned and stained with hematoxylin and eosin and toluidine blue. They were observed with a light microscope and a polarizing microscope. The obtained results were as follows : 1. Defected bone was healed fast from the odontogenic tissues in early stage of the experiment. 2. The arrangement of the bone matrix was relatively regular in the bone from the nonodontogenic tissues, but irregular in the bone from the odontogenic tissues. 3. Compact bone has started to be resorbed and changed to the pattern of matrix bone tissue from 3 weeks after experiment.

• 대한소아치과학회지
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• 제39권3호
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• pp.257-266
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• 2012

인공 우식 용액으로 72개의 건전한 치아에 백색 병소를 형성을 유도하고 $CavityShield^{TM}$(Group I), $FluroDose^{TM}$(Group II) 그리고 $Flor-Opal^{(R)}$ Varnish(Group III)를 2주 간격으로 1, 2, 3회 도포하였다. 마지막 불소 바니쉬 도포 2주 후 QLF-D 영상을 촬영하여 광도 변화량(${\Delta}L$)을 측정하였고, 편광 현미경으로 법랑질 탈회 깊이 변화량(${\Delta}D$)을 측정하여 통계적으로 비교하였다. 1. Group I, II, III에서 QLF-D로 관찰한 결과, 1회 도포군보다 2주 간격으로 2, 3회 도포군에서 유의하게 ${\Delta}L$ 값이 증가하였고, 각 불소 바니쉬에서 도포 횟수에 따라 회귀 분석 결과, y = 3.878x + 90.612, y = 3.133x + 37.168, y = 3.509x + 82.322의 회귀 방정식이 산출되었다(p < 0.05). 2. Group I, II, III에서 편광 현미경으로 관찰한 결과, 1회 도포군보다 2주 간격으로 2, 3회 도포군에서 유의하게 ${\Delta}D$ 값이 감소하였고, 각 불소 바니쉬에서 도포 횟수에 따라 회귀 분석 결과, y = -2.336x + 107.235, y = -2.158x + 101.620, y = -1.940x + 94.806의 회귀 방정식이 산출되었다(p < 0.05). 3. 불소 바니쉬 적용하고 편광 현미경으로 관찰한 인공 우식의 깊이 변화량과 QLF-D로 관찰한 광도 변화량 사이의 피어슨 상관 계수는 Group I에서 -0.673, Group II에서 -0.574, 그리고 Group III에서 -0.431이었다(p < 0.05).

• 한국광물학회지
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• 제9권2호
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• pp.102-112
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• 1996

The precious serpentine, referring to a rare and highly valuable gem variety of serpentine group minerals, is found to occur in serpentinite from Booyo Gren Jade Mine which is located in Oesan-myun, Booyo-gun of Chungchungnam-do. Geommological properties of the precious serpentine have been investigated by use of polarizing microscope, specific gravity balance, refractometer, hardness pencils, X-ray diffractometer, XRF, ICP-MS analyser, and infrared absorption spectroscope.The precious serpentine from Booyo is colored deep green with oily luster and semi-transparent. It is highly tough and Mohs's scale of hardness is measured to be 5-6. Specific gravity is determined to be 2.67, and a single refractive index ND=1.56 is observed by a spot method, using sodium light source. X-ray powder diffraction data is represented by the reflection lines at 7.40(100), 4.64(25), 3.68(68), 2.757(69), 2.530(49), 2.549(32), and 1.710(21${\AA}$), which compares very well with that of antigorite of serpentine group minerals. The major chemical compositions of the precious serpentine group minerals. The major chemical compositions of the precious serpentine are SiO2 42.49%, MgO 39.08%, Fe2O3 3.85%, and H2O 11.87%. Besides, trace elements such as Cr(2188), Ni(1110ppm), Co(58ppm), and Ta (108ppm) are relatively spectrum shows peaks at 3670, 1190, 1070, 980 and 610cm-1. Strong absorption at 3670cm-1 is due to OH stretching, and 1190, 1070 and 980cm-1 due to SiO stretching. The absorption 610cm-1 is formed by alteration of pre-existing ultramafic rock, namely peridotite, with an introduction of fluid with very little content of CO2, under 400$^{\circ}C$ environment. Magnetite inclusions, finely disseminated in the precious serpentine, may be a result of Fe precipitation, during serpentinization of olivine-bearing country rock.

• 치과방사선
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• 제24권2호
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• pp.263-274
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• 1994

The purpose of this study was to investigate the remodeling process of the streptozotocin-induced diabetic rat's resected condyle. This experiment was performed with male Sprague-Dawly strain rats weighing approximately 250 gm, which were rendered diabetic by an intravenous injection of streptozotocin(70㎎/㎏ body weight). After condylectomy, experimental rats were serially terminated on the 1st week, the 2nd week, the 3rd week, and the 4th week. The following termination, the mandibles were dissected out to make specimens. Each mandibular condyle was radiographed with Hitex HA-80(Hitex Co., Ltd. Japan). In addition to radiographic observation, the mandibular condyles, further decalcified and embedded in paraffin, were sectioned and stained with Hematoxylin and Eosin, Toluidine blue and Masson's trichrome. They were observed with a light microscope and a polarizing microscope. The results were as follows. 1. Soft X-ray radiograms revealed proliferation of bone after 1 week in both groups. Irregularly repaired bones and dense trabeculae were clearly observed in experimental group. 2. The resected condyles were repaired by intramembraneous and endochondral bone formation in both groups. 3. Bone tissue repair was initiated from the adjacent margin of resected bone, and cartilaginous tissues were observed at the top of repaired bone in both groups. 4. The number of osteoblasts of experimental group was small, compared with control group. Each osteoblast was small and flat. The thin trabeculae were irregularly formed. 5. Collagens of bone were gradually matured in both groups, but the degree of maturation was lower in experimental group. 6. Fibrous tissues covered the upper parts of repaired bone were densely arranged in the both groups. Conclusively, atrophied osteoblasts, immature collagen of bone, and thin and irregular trabeculae which were characterized in the diabetes experimental group showed diabetes disturbed osteoblastic function and caused disturbance of remodeling process of bone.

• 한국광물학회지
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• 제23권1호
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• pp.73-84
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• 2010

국내에서 투각섬석 석면이 채굴되었던 충남 보령지역의 석연광산인 중앙(신석)광산과 대보석산 광산에 대해서 투각섬석의 산출상태, 수반광물, 광물학적 특성, 형성과정을 연구하였다. 이곳의 투각섬석은 아주 긴 섬유상과 함께 침상, 도변상, 주상의 여러 형태가 같이 공존하였다. 유해석변의 기준에 해당되는 투각섬석에 대해 편광현미경과 주사전자현미경으로 형태를 분석한 결과, 길이가 최대 210 ${\mu}m$에 해당되는 입자도 있으나 평균치로는 31.2 ${\mu}m$이고, 폭은 평균 1.6 ${\mu}m$이며 종횡비는 평균 19.9이었다. 투각섬석의 신장방향에 대한 소광각은 6.1~20.2$^{\circ}$의 범위로 모두 사소광의 성질을 나타냈다. 석면상과 비석면상 투각섬석의 XRD 패턴도 약간의 차이를 나타냈다. EPMA의 분석 결과, 이곳의 투각섬석은 Mg성분이 Fe보다 월등히 높게 나타나서 Mg단종인 투각섬석에 가까운 것으로 확인되었다. 석면상과 주상의 투각섬석은 형성조건이 다소 다르며 석면상이 후기에 형성된 것으로 검토되였다.

• 대한치과교정학회지
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• 제30권3호
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• pp.317-333
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• 2000

급속 구개확장은 정중구개봉합을 이개하기 위하여 강한 힘을 치아에 가하게 된다. 확장후 정중구개봉합부에 존재하는 골모세포와 섬유모세포의 증식 활성도를 측정하여 정중구개확장이 생리적으로 진행되는지를 확인하고, 이때 개개 치아의 치주조직에서 나타나는 변화를 조사하기 위하여 약 10개월된 유성견 10마리를 대상으로 상악 제2소구치와 제1대구치에 Hyrak screw를 장착하였다. 실험동물은 대조군 1마리, 1주 확장한 군 3마리, 2주 확장한 군 3마리, 2주 확장후 2주 보정한 군 3마리로 구분하여, Screw를 1일 1/4회전시켜 확장하였고, 제2소구치, 제3소구치, 그리고 제 1대구치 부위의 정중구개봉합부와 치주조직을 절취하여 Soft X-ray로 관찰하고, 형태학적 및 면역조직화학적 변화를 광학현미경으로, 그리고 골개조를 편광현미경으로 관찰하여 다음과 같은 결과를 얻었다. 1. 편광현미경 소견에서는 대조군에 비하여 1주 확장군의 봉합부에서 골 형성과 흡수가 크게 증가되었으며, 2주 확장군에서 약간 감소를 보이다가, 보정군에서는 석회화가 크게 진행되었다. 2. 면역조직화학적 연구에서는 대조군에 비하여 1주 확장군의 봉합부에서 골모세포가 PCNA(Proliferating Cell Nuclear Antigen)에, 미분화 섬유모세포가 EGF(Epidermal Growth Factor)에 약간 증가된 양성 반응을 보였으며 EGF에 대한 골모세포의 반응은 낮았다. 2주 확장군에서는 섬유아세포와 골모세포에서 PCNA와 EGF에 대한 양성반응이 증가되었다. 보정군에서는 이들 PCNA와 EGF에 양성반응을 나타내는 세포들이 구개돌기 골단 주변에 집중되었다. 3. 확장기간 중 봉합부 주변에서 광범위한 골 흡수와 골형성을 동반한 골개조가 일어났으며, 보정군에서는 다소 감소하였다. 2주 확장군과 보정군의 제3소구치 와 제1대구치의 치근단에서 백악질 형성과 흡수가 나타났으며, 제1대구치의 협측 치경부에서 광범위한 초자양 변성대가 나타났다. 4. Soft X-ray소견에서 1주 확장군은 대조군에 비교하여 봉합부위의 여러부분에서 미세 파절과 저석회화된 결손부위를 보였다. 대조군과 보정군 사이 에는 정중구개봉합부의 석회화 정도에 별 차이 가 없었다. 2주 확장군과 보정군에서 제3소구치와 제1대구치는 협측으로 경사되는 경향을 보였다.