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Mössbauer Study on the Variation in Magnetic Properties of CuO Induced by 57Fe Addition (57Fe 이온이 CuO에 미치는 효과에 관한 Mössbauer 분광 연구)

  • Park, Jae-Yun;Kim, Kwang-Joo
    • Journal of the Korean Magnetics Society
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    • v.19 no.3
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    • pp.113-119
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    • 2009
  • $^{57}Fe_xCu_{1-x}O$(x = 0.0, 0.02) powders were prepared by sol-gel method and their crystallographic and magnetic hyperfine properties have been studied using X-ray diffraction and $M{\ddot{o}}ssbauer$ spectroscopy (MS). The crystal structure of the samples is found to be monoclinic without any secondary phases and their lattice parameters increase with increasing annealing temperature ($T_A$), which is attributed to an increase in oxygen-vacancy content. MS measurements at room temperature indicate that $Fe^{3+}$ ions substitute $Cu^{2+}$ sites and ferromagnetic phase grow with increasing $T_A$. Magnetic hyperfine and quadrupole interactions of $^{57}Fe_{0.02}Cu_{0.98}O$ ($T_A=500^{\circ}C$) in the antiferromagnetic state at 17 K have been studied, yielding the following results: $H_{hf}=426.94\;kOe$, ${\Delta}E_Q=-3.67\;mm/s$, I.S.=0.32 mm/s, ${\theta}=65^{\circ}$, ${\phi}=0^{\circ}$, and ${\eta}=0.6$.

Petrology and Geochemistry of Peridotite Xenoliths from Miocene Alkaline Basalt Near the Mt. Baekdu Area (백두산 지역의 마이오세 알칼리 현무암에 포획된 페리도타이트의 암석학적/지화학적 특성)

  • Kim, Eunju;Park, Geunyeong;Kim, Sunwoong;Kil, Youngwoo;Yang, Kyounghee
    • The Journal of the Petrological Society of Korea
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    • v.26 no.4
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    • pp.311-325
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    • 2017
  • Peridotite xenoliths in middle Miocene alkaline basalt from the Mt. Baekdu area are mainly anhydrous spinel lherzolites, displaying coarse-grained protogranular texture. These xenoliths have late-stage secondary orthopyroxene replacing olivine as the metasomatic mineral and glass formed along the grain boundaries. The studied xenoliths are characterized by the high $Mg{\sharp}[=100{\times}Mg/(Mg+Fe_{total})$ atomic ratio] of olivine, orthopyroxene and clinopyroxene (89~92) and the $Cr{\sharp}[=100{\times}Cr/(Cr+Al)$ atomic ratio] of spinel (10~29). Based on major-element data, the studied xenoliths are similar to those from the abyssal peridotites. Clinopyroxenes of the xenoliths are mostly enriched in incompatible trace elements, exhibiting two types of REE patterns: (1) LREE-depleted with $(La/Yb)_N$ of 0.1~0.2 and $(La/Ce)_N$ of 0.4~0.8. (2) LREE enriched with $(La/Yb)_N$ of 2.2~3.8 and $(La/Ce)_N$ of 1.2~1.6. The calculated equilibrium temperatures and oxygen fugacities resulted in $920{\sim}1050^{\circ}C$ and ${\Delta}fO_2(QFM)=-0.8{\sim}0.2$, respectively. It is suggested that the Mt. Baekdu peridotite xenoliths represent residues left after variable degrees of melt extraction(less than 15 vol%), which was subsequently subjected to different degrees of modal/cryptic metasomatism by silica- and LREE-enriched fluids (or melts).

Development of GPS/IMU/SPR Integrated Algorithm and Performance Analysis for Determination of Precise Car Positioning (정밀 차량 위치결정을 위한 GPS/IMU/SPR 통합 알고리즘 개발 및 성능 분석)

  • Han, Joong-Hee;Kang, Beom Yeon;Kwon, Jay Hyoun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.2
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    • pp.163-171
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    • 2014
  • Based on the GPS/IMU integration, the car navigation has unstable conditions as well as drastically reduces accuracies in urban region. Nowadays, many cars mounted the camera to record driving states. If the ground coordinates of street furniture are known, the position and attitude of camera can be determined through SPR(Single Photo Resection). Therefore, an estimated position and attitude from SPR can be applied measurements in Kalman filter for updating errors of navigation solutions from GPS/IMU integration. In this study, the GPS/IMU/SPR integration algorithm was developed in loosely coupled modes through extended Kalman filters. Also, in order to analyze performances of GPS/IMU/SPR, simulation tests were conducted in GPS signal reception environments and the GCPs (Ground Control Points) distributions. In fact, the position and attitude gathered from GPS/IMU/SPR integration are more precise than the position and attitude from GPS/IMU integration. When IPs (image points), corresponded to GCPs, were concentrated in the center of image, the position error in the optical axis respectively increased. To understand effects from SPR, we plan to carry additional test on the magnitude of GCP, IP and initial exterior orientation errors.

Cabboic Xenoliths in Alkaline Basalts from Jeju Island (제주도 알칼리 현무암에 포획된 반려암질 포획암)

  • Eom, Young-Bo;Nam, Bok-Hyun;Hwang, Byoung-Hoon;Kim, Jin-Seop;Yang, Kyung-Hee
    • Journal of the Mineralogical Society of Korea
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    • v.20 no.2 s.52
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    • pp.103-114
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    • 2007
  • Gabbroic xenoliths in poikilitic and equigrnular textures and plagioclase megacrysts, up to 15 cm in size, are trapped in alkaline basalts from Sinsanri and Sangeumburi, Jeju island. Gabbroic xenoliths are gabbro norite in composition. Plagioclase is the most dominantly present $(42{\sim}94vol%)$, while olivine crystals are absent. Pokilitic xenoliths, interpreted as cumulates, include euhedral opx+cpx in oikocryst plagioclase. Equigranular xenoliths include subhedral to anhedral opx+cpx+pl. Based on the textural and geochemical natures, occurrence mode at the outcrops, poikiltic and equigranular xenoliths and plagioclase megacrysts were from rigid zone, mushy zone and crystal-suspended zone of the magma chamber, respectively. The gabbroic xenoliths in alkaline basalts of the Juju island represent crystallization products of relatively evolved basaltic magma at the Jeju magma reservoir beneath the Jeju Island. They are gabbro fragments that represent crystallization-isolation-capture processes associated with magma batches temporarily occupying reservoirs.

The Safety and Usefulness of Synthetic Absorbable Monofilament, Glycoside-$\varepsilon$-caprolactonetrimethylene Carbonate Interpolymer, in Gastrointestinal Anastomosis and Closure (위장관문합 및 봉합 시 인공 흡수성 단사인 Glycoside-$\varepsilon$- caprolactone-trimethylene Carbonate 혼성중합체의 안정성 및 유용성)

  • Lee Hyuk-Joon;Kim Yoon Ho;Yang Han-Kwang;Lee Kuhn Uk;Choe Kuk Jin
    • Journal of Gastric Cancer
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    • v.3 no.2
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    • pp.93-96
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    • 2003
  • Purpose: Synthetic absorbable monofilaments offer excellent glide characteristics and cause minimal tissue trauma as a result of their smooth monofilament structure and gradual absorption within the healing tissues. For these reasons, these suture materials are commonly used in various surgical fields such as gastroenterology, urology, gynecology, and plastic surgery. The aim of this study was to evaluate the safety and usefulness of a new synthetic absorbable monofilament, Glycoside-..-caprolactone-trimethylene carbonate interpolymer (GCT), in gastrointestinal anastomosis and closure. Materials and Methods: We evaluated 55 gastrointestinal anastomoses and closures using GCT $MONOSYN^{R}$, B. Braun, Germany) in 47 patients who underwent gastric surgery between December 2001 and May 2002 at Seoul National University Hospital. Patient's characteristics, operative procedure, surgeon's opinion of handling properties of GCT, and suture-related complications were analyzed. Results: There were 34 males and 13 females (M:F= 2.6:1) with an average age of 54.2 years old. Forty-five cases of gastrointestinal anastomosis (20 gastrojejunostomies and 25 jejunojejunostomies) and 10 cases of intestinal closure (7 gastrostomy closures and 3 duodenal stump closures) were performed in 41 cases of stomach cancer, three of peptic ulcer disease, two of GIST, and one MALToma. The handling properties of GCT according to the criteria of knot breaking load, knot security, and placing property were always scored with 7 to 9 points (10=excellent, 1=very poor). Two cases of postoperative complications ($3.6\%$) were noted. One was a leak of the gastrojejunostomy site which was successfully managed conservatively, and the other was a stricture of the gastrojejunostomy site which was managed by reoperation (side-to-side jejunojejunostomy). Conclusion: GCT seems to be an applicable suture material for various gastrointestinal anastomoses and closures.

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Phenocryst Composition of Mafic Volcanic Rocks in the Wangtian'e Volcano (망천아 화산 고철질 암석의 반정광물 조성 연구)

  • Yun, Sung-Hyo
    • The Journal of the Petrological Society of Korea
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    • v.28 no.1
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    • pp.15-24
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    • 2019
  • There are beautiful scenery with columnar jointing at 15 valley of southern slope of the Wangtian'e volcano in Mt. Baekdu volcanic field. The compositions of phenocryst minerals which have porphyritic textures in mafic volcanic rocks of this area were carried out. The Wangtian'e volcano consists of Changbai basalt~trachybasalt (lower part) and Wangtian'e basaltic trachyandesite~trachyte~alkali rhyolite (upper part). This study is focused on the mafic rocks of the Changbai trachybsalt and the Wangtian'e basaltic trachyandesite. Main phenocrysts are feldspar, pyroxene and olivine. The major element compositions of the phenocrysts were analyzed using EPMA. Plagioclase phenocrysts of the Wangtian'e basaltic trachyandesite are located at the border of andesine and oligoclase ($An_{24.1{\sim}36.0}$) in the An-Ab-Or diagram, and those of the Changbai trachybasalt are labradorite ($An_{54.2{\sim}65.2}$). Pyroxene phenocrysts are augite. Olivine phenocrysts of the Changbai trachybsalt are crysolite ($Mg_{0.79-0.77}Fe_{0.21-0.23}$) and microphenocrysts in the groundmass are hyalosiderite ($Mg_{0.58-0.56}Fe_{0.42-0.44}$). Calculated crystallization temperature of olivine phenocrysts is $1196{\sim}1123^{\circ}C$, clinopyroxene is $1122{\sim}1112^{\circ}C$, phenocrysts and laths of plagioclases are $1118{\sim}1107^{\circ}C$ and $1091{\sim}1089^{\circ}C$, respectively. The temperatures suggests that the olivine phenocrysts, clinopyroxene, plagioclase phenocrysts, and plagioclase laths were crystallized in the magma chamber in sequence.

종료종모돈이 3원 교잡종의 육질에 미치는 영향

  • 최임수
    • 종축개량
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    • v.20 no.1
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    • pp.93-102
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    • 1998
  • 3원교잡종의 지육지방축척과 육질에 대한 종료종모돈(두록종:D, 버크셔종:B, 매산돈:M)의 영향을 보기 위해, 랜드레이스종과 대요크셔종의 F1(LW) 종빈돈에 D, B 또는 M종의 3품종의 종모돈을 교배시켜 얻은 3원교 잡종(LWD, LWB, LWM)에 대해서 지육의 지방 축적량, 로스육의 물리적 특성과 화학적 조성 또는 근육섬유의 특성, 근육과 피하지방의 지방산 조성을 비교 검토했다. 시험돈은 3원교잡종 각각에 대해서 거세돈 수컷과 암컷을 각각 6두씩, 합계 36두를 공시했다. 단사(單飼), 무제한 급여 하에서 체중이 30kg에서 105kg가 될 때까지 사육했다. 도살한 돼지의 지육우반환(枝肉右半丸)의 제5-6, 8-9, 11-12, 13-14 흉추(胸椎) 간, 제16흉추-제1요추(腰推) 또는 최후요추-제1선추(仙推)간의 횡단면지방의 면적비율은 어떠한 부분에도 LMW이 LWD, LWB보다 통계적으로 유의가 많았다. 로스육의 물리적 특성치인 Tenderness는 $LWM961.3Kgw/cm^2)$ of $LWD(84.13KgW/cm^2)$$LWD(87.22KgW/cm^2)$보다 유의적으로 부드럽고, Pliability는 역으로 LWM이 LWD, LWB보다 유의 있게 낮았다. 또 로스육의 근육내 지방함량은 $LWM(3.23\%)$$LWD(2.32\%)$$LWB(2.35\%)$보다 유의성 있게 많았고, 가열 손실율(加熱損失率)은 LWM이 LWD, LWB보다 유의성 있게 높았다. 근섬유경(筋纖維經)은 LWD가 LWB, LWM보다 큰 경향으로 인정되어 지고, 근속(筋束)의 횡단면적은 LWD가 LWB 또는 LWM보다 유의 있게 조밀했다. LWM은 근육 내 지방산인 오레인산이 LWD, LWB보다 훨씬 높았고, 불포화 지방산의 비율이 높았다. 이상의 결과 종료종모돈이 3원교잡종의 육질에 영향을 미친다는 것이 명확하게 되었다.

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Na와 Dy 이온 첨가에 따른 MgWO4 형광체의 광학 특성

  • Kim, Mun-Ju;Gang, Hui-Seung;Park, Da-Jeong;Jo, Seon-Uk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.199-199
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    • 2016
  • 본 연구에서는 고상반응법을 사용하여 제조한 MgWO4:Dy,Na 형광체의 광학특성과 결정구조를 조사하였다. Fig.1 XRD 주 피크는 $23.9^{\circ}$에서 관측 되었으며 (110) 면에서 발생한 회절신호이다. 결정구조는 단사정계임을 알 수 있었다. Dy,Na의 함량비를 0 mol, 0.02 mol, 0.04 mol, 0.06 mol, 0.08 mol, 0.10 mol로 변화시켜 합성했으나, 함량비와는 관계없이 동일한 XRD 회절 피크 패턴이 관측되었다. Fig.2. 그림의 220-340 nm에서 관찰되는 넓은 밴드는 $O2-{\rightarrow}W6+$에 의해 발생한 LMCT(ligand to metal charge transfer)이고, Dy에서 WO42- 그룹으로 에너지 전달에 의해서 생긴 CTB 이다. 합성한 형광체를 295 nm로 여기 시킨 모든 형광체 분말의 발광 스펙트럼은 Dy 이온의 $4F9/2{\rightarrow}6H15/2$ 전이에 의한 487 nm, $4F9/2{\rightarrow}6H13/2$ 전이에 의한 577 nm, $4F9/2{\rightarrow}6H11/2$ 전이에 의한 668 nm의 발광 스펙트럼이 관측되었다. Dy 이온이 0.02 mol일 때, 발광 세기가 가장 강하였으며, 몰 비가 증가함에 따라 발광의 세기는 감소하는 농도 소광현상이 관측되었다.

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X-Ray and NMR Studies of Vanadium(V)-Nitrilotriacetate Complex (바나듐(V)-니크릴로트리아세테이트 착물의 X-선 및 핵자기공명 연구)

  • Lee, Man-Ho;Jeong, Woo-Won
    • Analytical Science and Technology
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    • v.10 no.3
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    • pp.196-202
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    • 1997
  • New vanadium(V) complex, $(NH_4)_2[VO_2NTA]$, has been synthesized and its structure has been determined by solution and solid-state NMR spectroscopies as well as X-ray crystallography. The unit cell of the monoclinic crystals contains four complexes with $a=6.923(1){\AA}$, $b=8.824(2){\AA}$, $c=19.218(11){\AA}$ and ${\beta}=91.60(3)^{\circ}$ in the space group of $P2_1/n$. The $[VO_2NTA]^{2-}$ anion has distorted octahedral geometry with cis-$VO_2$ moiety. It is confirmed that the octahedral geometry is retained in both of solution and solid-state complexes.

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사파이어 기판에 증착한 MgMoO4:Eu3+ 박막의 광학 특성

  • Gang, Dong-Gyun;Kim, Jin-Dae;Jo, Sin-Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.185.1-185.1
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    • 2015
  • 본 연구에서는 라디오파 마그네트론 스퍼터링 방법을 사용하여 증착 온도를 변화시켜면서 Eu 이온이 도핑된 MgMoO4 적색 형광체 박막을 사파이어 기판 상부에 성장하였다. 타겟은 고상반응법을 사용하여 직접 제작하였다. 형광체 박막의 구조, 표면, 광학적 특성은 X-선 회절장치, 주사전자현미경, 투과도 및 광여기발광 측정장치를 사용하여 측정하였다, 증착 온도는 100, 200, 300, $400^{\circ}C$이었으며, 증착 후 $870^{\circ}C$에서 열처리 공정을 실행하였다. 이와 더불어, $400^{\circ}C$에서 증착한 박막을 다양한 온도 $770-920^{\circ}C$에서 열처리를 수행하여 각각의 특성을 분석하였다. 증착 온도 $200^{\circ}C$에서 성장한 박막의 경우에 614 nm에 피크를 갖는 주 적색 발광 피크가 관측되었으며, 열처리 온도를 달리한 박막의 경우에는 $920^{\circ}C$에서 가장 강한 발광 피크가 나타났다. UV-VIS 분광광도계를 사용하여 박막의 투과도와 흡광도를 측정하였으며, Tauc의 모델을 사용하여 밴드갭 에너지를 계산하였다. 증착 온도 변화에 따라 성장된 박막의 투과도는 평균 82% 이상 이었으며 밴드갭 에너지는 4.1 eV이었다. 박막의 결정 구조는 단사정계임을 확인하였다. 특히, 결정 입자, 발광 피크의 세기와 투과도의 상관 관계를 조사하였다.

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