• 제목/요약/키워드: X-group

검색결과 4,356건 처리시간 0.032초

리튬 2차전지용 양극소재 $LiFePO_4/C$의 합성 및 리트벨트 구조분석 (Synthesis and Rietveld Refinement of the Cathode Material $LiFePO_4/C$ for Rechargeable Lithium Batteries)

  • 황길찬;최진범;김재광;안주현
    • 한국광물학회지
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    • 제22권1호
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    • pp.63-72
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    • 2009
  • 개량된 MA법으로 합성된 $LiFe(PO_4)/C$에 대해 X-선 회절분석을 실시하여 리트벨트법에 의해 결정학적 연구를 수행하였다. 리트벨트 계산 결과 리트벨트 R 지수 값은 $R_p=8.14%,\;R_{wp}=11.1%,\;R_{exp}=9.09%,\;R_B=3.88%$, S (GofF, Goodness of fit) = 1.2으로 계산이 잘 이루어졌음을 알 수 있다. $LiFePO_4/C$는 공간군 Pnma를 가지며, 격자상수 값은 a = 10.3229(3)${\AA}$, b = 6.0052(2) ${\AA}$, c = 4.6939(1) ${\AA}$이고 체적값은 V = 290.98(1) ${\AA}^3$으로 기존 다른 합성법의 연구결과와 잘 일치한다. 분말 입자는 고순도를 가지고 나노 크기($65{\sim}90nm$)로 기존 MA법보다 상대적으로 미세하고 균질도가 향상되었다. 따라서 개량된 MA법은 상업용 리튬 2차 전지의 양극물질 생산을 위한 우수한 제조법으로 판단된다.

Updated Assessment of the Association of the XRCC1 Arg399Gln Polymorphism with Lung Cancer Risk in the Chinese Population

  • Yang, Hai-Yan;Yang, Si-Yu;Shao, Fu-Ye;Wang, Hai-Yu;Wang, Ya-Dong
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권2호
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    • pp.495-500
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    • 2015
  • Background: Published studies have reported relationships between X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism and lung cancer risk in Chinese population. However, the epidemiological results remained controversial. The objective of this study was to clarify the association of XRCC1 Arg399Gln polymorphism with lung cancer risk in the Chinese population. Materials and Methods: Systematic searches were performed through the database of Medline/Pubmed, Web of Science, Embase, CNKI and WanFang Medical Online. Odds ratios (ORs) with 95% confidence interval (95%CI) were calculated to estimate the strength of the association. Results: Overall, we observed an increased lung cancer risk among subjects carrying XRCC1 codon 399 Gln/Gln genotype (OR=1.36, 95%CI: 1.09-1.71) in the Chinese population on the basis of 19 studies with 5,416 cases and 5,782 controls. We did not observe any association between XRCC1 codon 399 Arg/Gln and Arg/Gln+Gln/Gln polymorphisms and lung cancer risk (OR=1.00, 95%CI: 0.92-1.08 and OR=1.05, 95%CI: 0.97-1.13, respectively). Limiting the analysis to studies with controls in agreement with Hardy-Weinberg equilibrium (HWE), we observed an increased lung cancer risk among subjects carrying XRCC1 codon 399 Gln/Gln genotype (OR=1.18, 95%CI: 1.01-1.38). When stratified by source of control, we observed an increased lung cancer risk among subjects carrying XRCC1 codon 399 Arg/Gln+Gln/Gln genotype on the basis of hospitalized patient-based controls (OR=1.21, 95%CI: 1.04-1.42) and among subjects carrying XRCC1 codon 399 Gln/Gln genotype on the basis of healthy subject-based controls (OR=1.22, 95%CI: 1.04-1.43). Conclusions: Our findings indicated that certain XRCC1 Arg399Gln variants might affect the susceptibility of lung cancer in Chinese population. Larger sample size studies are required to confirm our findings.

IKUTON" 발효(醱酵) 고구마 전분박(澱粉粕)의 양돈사료(養豚飼料) 대체(代替)에 관(關)한 연구(硏究) (Studies on "IKUTON" Fermented Sweet Potato Starch Pulp for Growing-Finnishing Swine Ration)

  • 한성욱;정창조
    • 농업과학연구
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    • 제3권2호
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    • pp.192-197
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    • 1976
  • IKUTON 발효(醱酵) 고구마 전분박(澱粉粕)의 농후사료대축수준(濃厚飼料代蓄水準) 調査하기 위하여 Large Yorkshire, Landrace, Duroc Jersey 삼품종(三品種) 교잡종(交雜種) 25두(頭)를 공시(供試)하여 농후사료(濃厚飼料)를 급여(給與)한 대조구(對照區)와 IKUTON 발효(醱酵) 고구마 전분박(澱粉粕) 10%, 20%, 30% 및 40%를 대치한 5개처리구(個處理區)를 완전임의배치(完全任意配置)하여 시험(試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 사료섭취량(飼料攝取量)은 40% 구(區)를 제외(除外)한 기타(其他)의 각처리구(各處理區)에서는 대조구(對照區)에 비(比)하여 유의적(有意的) (P<0.05)인 차이(差異)를 인정(認定)할 수 없었으며 40% 이상(以上)의 대체수준(代替水準)에서 사료섭취량(飼料攝取量)이 감소(減少)되고 있었다. 사료효율(飼料效率)은 20% 구(區); 3.43, 30% 구(區); 3.80, 10% 구(區) 3.97, 40% 구(區); 4.20, 0% 구(區0; 4.53의 순(順)으로 대조구(對照區)에 비(比)하여 높은 사료효율(飼料效率)을 나타내고 있었다. 증체량과 80kg 도달주수(到達週數)는 10% 구(區); 12주(週), 0%구(區); 13주(週), 20% 및 30%구(區)가 14주(週)였고 40%구(區)는 15주(週)까지도 80kg에 도달(到達)치 못하고 있었으며 대조구(對照區)에 비(比)하여 64%의 증체밖에 되지 않었다. 시험사료(試驗飼料)의 소화율(消化率)은 75.2~87.5%였으며 급수율(給水率)은 사료섭취(飼料攝取) 1kg당(當) $1.95-2.01{\ell}$로 되고 있어 사료급여회수(飼料給與回數)는 소화율(消化率)과 급수율(給水率)에 아무런 영향을 주지 않었다.

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TM31010 계열의 공동이온전리함과 TG-51을 이용한 선형가속기광자선의 5년간 출력선량 평가 (Evaluation of the Output Dose of a Linear Accelerator Photon Beams by Using the Ionization Chamber TM31010 Series through TG-51 Protocol to Postal Monitoring Output of RPC for 5 Years)

  • 최태진;김옥배
    • 한국의학물리학회지:의학물리
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    • 제22권2호
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    • pp.92-98
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    • 2011
  • 방사선의 출력선량계수는 모든 선량계획과 치료선량결정에 영향을 주게 되므로, 정확한 선량평가가 강조되고 있다. 저자들은 물흡수선량을 결정하는 선량프로토콜을 종전의 TG-21에서 TG-51로 전환하여 2007년부터 새로운 버전과 새로운 공동전리함으로 선량을 평가하기 위해 SSDL의 $N_k$$N_{dw}{^{Co-60}}$로 변환하여 적용하였다, 평가된 물흡수선량계수는 치료선량결정과 RPC의 선량모니터링을 통해 비교되었으며, 선량평가는 2% 이내를 보였지만 불안정성을 확인하게 되었으며, 선량평가과정을 후향적으로 모니터하였다. 점검결과 새 전리함의 교정계수가 -2.8% 낮은 것을 확인하고 PSDL의 물흡수선량교정계수를 구하여 출력선량계수를 구하였으며, 선량평가 결과 2010년부터 안정되었고 지속적으로 1% 이내의 오차를 나타내었다.

C.M.I.간이법에 의한 노인들의 건강수소율 (Health Complaints of Elderly Persons Using a Modified C.M.I.)

  • 박오장
    • 대한간호학회지
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    • 제13권2호
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    • pp.44-57
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    • 1983
  • The explosion of the aging population is changing the social environment of today's older people. Traditionally in Korea, a large percentage(over 90%) of elderly parents have lived with their married first son. But today, the number of elderly who live with their married sons has decreased(65.6%) The number of those who live in a different situation such as with their married daughter, unmarried offspring, with a spouse or alone has increased (34.4%) We can expect that the number of the elderly who have to live in institution will increase. The objective of this investigation was to determine differences in the number of health Complaints of older people according to their living situation with a view to planning more effective health care. The sample consisted of 231 persons over 65 years of age, 60 living in an Old Age Home ana 171 living in their own home in Kwangju. Data were gathered from July 9 to 26, 1983 by nursing students using a Questionnaire which was a modified form of the Cornell Medical Index. The data were categorized according to the subjects, living, sex, educational level, previous occupation, hobbies and sexual activity. The date were analyzed for statistical significant differences using F and X²tests. findings included the following: 1. There was a higher number of health complaints from persons who live in the institution than those living at home, but the difference was not significant. 2. The highest number of health Complaints were from persons who live alone, followed by those living with their daughters, and then by those living in the institution. Persons who live with their sons had the least Complaints. The difference in the number of Complaints accord-ing to with whom they were living was significant. 3. Women had signincantly more Complaints than men. Persons who were not living with their spouses had significantly more complaints than those living with their spouses.4. The higher eductional level the persons had, the less health Complaints they had. The number of Complaints accoraing to educational level was significantly different. 5. The highest number of health complaints were from persons who had involved in Commerce and industry, followed by those in Agriculture. Persons who were civil servant had the least 6. There were more complains from persons who had no hobby than those with hobbies. The complaints. The difference was significant. difference was significant. 7. Persons who said they were sexually inactive had significantly more complaints than those who said they were sexually active. As age increased, sexual activity significantly decreased. Those who lived with their spouse were significantly more sexually active. 8. The highest number of Somatic Complaints were eye fatigue, followed by nocturnal frequency, lumbago, cramps in extremities, vertigo, stiffness in Shoulder, tinnitus, common cold and constipation. The order of Psychic Complaints from higher to lower were anger. sensitivity, anxiety, depression and loneliness. 9. This group of Elderly persons said they valued Health the most, followed by Harmony, Religion, Money and Honor.

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$Li_2$$CO_3$, ${NiCO_3}$, $CoCO_3$로부터 $LiNi_{1-y}$${Co_y}{O_2}$의 합성 및 전극특성 연구 (A Study on the Synthesis and the Electrochemical Properties of $LiNi_{1-y}$${Co_y}{O_2}$from $Li_2$$CO_3$, ${NiCO_3}$, and $CoCO_3$)

  • 임호;강성구;장순호;송명엽
    • 한국세라믹학회지
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    • 제38권6호
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    • pp.515-521
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    • 2001
  • 출발 물질로서 L $i_2$C $O_3$, NiC $O_3$, CoC $O_3$를 사용하고 조성과 합성 온도를 변화시켜, 고온 고상법에 의하여 LiN $i_{1-y}$ $Co_{y}$ $O_2$(y=0.1, 0.3, 0.5)를 합성하였다. 합성과 시료들의 결정구조, 미세구조 그리고 전기화학적 특성을 조사하였다. 80$0^{\circ}C$와 8$50^{\circ}C$에서 제조한 L $i_{x}$N $i_{1-y}$ $Co_{y}$ $O_2$는, 삼방정계(space group: R3m)의 $\alpha$-NaFe $O_2$구조로 결정화되어 있는 층상 구조를 형성하였다. LiN $i_{1-y}$ $Co_{y}$ $O_2$(y=0.1, 0.3, 0.5)는 Co의 양이 증가함에 따라 a축과 c축의 크기가 감소하였는데, 이는 코발트 이온의 크기가 니켈 이온의 크기보다 작은데 기인하는 것이다. 그러나 c축과 a축의 크기의 비(c/a)가 증가하였음은 이차원적 구조가 잘 발달됨을 보여준다. 니켈에 대한 코발트의 치환량에 따른 리튬 이온의 삽입/추출 가역성은 코발트의 치환량이 증가하면서 증가하여 y=0.3인 LiN $i_{0.9}$ $Co_{0.1}$ $O_2$에서 대체로 우수하였고 그 이상으로 y값이 증가하면 가역성이 나빠졌다. 80$0^{\circ}C$에서 합성한 LiN $i_{0.9}$ $Co_{0.1}$ $O_2$가 가장 큰 초기 방전 용량 146 mAh/g을 나타내었으며, 싸이클링 성능도 비교적 우수하였다. 8$50^{\circ}C$에서 합성한 LiN $i_{0.9}$ $Co_{0.1}$ $O_2$와 LiN $i_{0.7}$ $Co_{0.3}$ $O_2$가 우수한 싸이클링 성능을 보였다.다. 싸이클링 성능을 보였다.다.보였다.다.

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이트리아를 첨가한 저코니아의 합성과 결정구조 (Synthesis and Crystal Structure of Yttria-Stabilized Zirconia)

  • 김원사;서일환;박로학;김문집;김헌준;이창희;김용채;성백석;이정수;심해섭;김이경;이진호
    • 한국지구과학회지
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    • 제18권6호
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    • pp.553-558
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    • 1997
  • 등축정계의 결정구조를 지니는 무색 투명한 저코니아($Zr_{0.73}Y_{0.27}O_{1.87}$) 결정을 $Y_2O_3$를 안정제로 사용하여 Bridgman-Stockbager법(또는 Skull 용융법)으로 합성하였다. 육성된 결정은 유리광택을 나타내며 동시에 약간의 지방 광택도 띤다. 저코니아 결정은 편광현미경하에서 등방성을 나타내며 이방성의 징후는 발견되지 않는다. 모스 경도는 $8{\sim}8\frac{1}{2}$이고 비중은 5.85이다. 자외선하에서는 약한 백색 형광을 낸다. 단결정법으로 결정한 저코니아의 결정구조는 등축정계이며, 공간군은 $Fm3m({O^5}_h)$이다. 단위포 상수(a)는 $5.1552(5){\AA}$이며, $V=136.99(5){\AA}$, Z=4, R=0.0488이다. 저코니움 원자는 각 모서리에 산소 원자가 자리잡고 있는 육면체의 중심에 위치하고 있으며, 각 산소 원자는 저코니움 원자로 되어 있는 사면체의 중심에 위치하고 있다. 결국 8:4의 배위수가 성립하는 구조를 하고 있다.

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하악골 전돌증을 동반한 안모비대칭의 유형 분석 (FACIAL ASYMMETRY WITH MANDIBULAR PROGNATHISM - A NEW TRIAL OF CLASSIFICATION AND INTERPRETATION -)

  • 윤규식;정영수;강군철;박형식
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제30권2호
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    • pp.108-120
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    • 2004
  • Object : Patients with facial asymmetry accompanying mandibular prognathism have various causes and clinical features. So, it is difficult to find a satisfactory treatment method functionally and esthetically. Every traditional classification and interpretation to find etiopathogenesis and/or to establish ideal surgical modality has many limitations because it can't be applied simply to various conditions of patients with facial asymmetry accompanying mandibular prognathism. Therefore, we employ a new classification to interpret more details of the morphologic change of mandible and the spatial change of mandible and maxilla. Materials and Methods : Using panoramic X-ray films, PA cephalograms and submentovertex films of 126 patients diagnosed with facial asymmetry accompanying mandibular prognathism as resources, the following results were gathered after analyzing each characteristics through distributing the patterns according to the morphological mandibular asymmetry and mandibular and maxillary spatial asymmetry. Results : Almost frequency of morphological mandibular asymmetry was shown. In case of condyle-ramus elongation and body elongation group, it's frequency was the highest. Higher frequency of compensating vertical growth was shown on the side of over growing maxilla in case of vertical length difference between left and right condyle-ramus. On the other hand, higher frequency of no compensating vertical growth difference between left and right side was shown in case of no vertical length difference in condyle-ramus. Spatial mandibular asymmetry generally occurred when there was no morphological mandibular asymmetry. Correlation between condyle length difference and condyle-ramus length difference between left and right side was very high, but correlation between condyle length difference and body length difference, and correlation between condyle length difference and body vertical length difference was low. Conclusion : In case of patients with facial asymmetry accompanying mandibular prognathism, it is suggested that various pattern of facial asymmetry is occurred by the independent growth of each unit rather than dependent growth of other unit by major growth unit abnormality. Due to the untypical pattern and the various asymmetry occurring according to the changes of each mandibular growth unit, it is considered that an appropriate surgical method should be searched based on the accurate recognition of the each pattern for patients with facial asymmetry accompanying mandibular prognathism.

주조기와 매몰재의 성분변화에 따른 티타늄의 주조성에 관한 연구 (THE EFFECT OF CASTING MACHINE AND INVESTMENT ON THE CASTABILITY OF TITANIUM ALLOY)

  • 정다운;양홍서
    • 대한치과보철학회지
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    • 제44권5호
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    • pp.654-664
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    • 2006
  • Statement of problem: There has been a eat interest in the use of titanium for fixed and removable prostheses in recent because of its excellent biocompatibility. However, the melting temperature and chemical reactivity of titanium necessities casting system different from those used in conventional casting. The current titanium casting systems are based on an electric-arc design for melting the metal in an argon atmosphere and its exclusive investment. Despite the new development in Ti casting system, inadequate mold filling and internal porosity are frequently observed casting defects. Purpose : The purposes of this study were to compare the castibility and reaction layer of the casting titanium under the two casting machines and their investment condition. Material and method: coping and machine-milled titanium coping according to the casting methods and the marginal configurations. The total 28 specimens were used, and these are divided into 4 groups according to 2 casting machines and 2 investments. The castings were analyzed using x-ray microanalysis and microhardness testing. The reaction layer between margin of titanium casting and the investments was observed and analyzed with scanning electron microscope. Result: 1. Castabiliy of casting titanium specimen was best in the group of centrifugal casting machine and Selevest $CB^{\circledR}$ and good that of Selevest CB and pressure differential casting machine, Rematitan plus and centrifugal casting machine, Rematitan plus and pressure differential casting machine in order. 2. There was no significanct correlation in titanium castability in respect of casting machine. However ANOVA indicated that Selevest $CB^{\circledR}$ groups had significantly better castability than Rematitan $plus^{\circledR}$ groups.(p<0.05) 3. There was a significant microhardness difference between centrifugal casting machine groups and pressure differential groups.(p<0.05) Titanium castings in centifugal groups had significantly harder than those in pressure differential groups. 4. The addition of zirconia decreased interfacial reactivity. Conclusion: above result revealed that of the castability of titanium casting specimens had little correlation in casting machines and was better in magnesia-based investment contained ZrO2 groups. However in order to practice casting titanium in clininic, its castability should be improved, also there should be more research on factor of castability so that long-span prothesis and removable partial denture metla frame may be casted completly.

Silver diamine fluoride와 sodium fluoride (NaF) 바니쉬의 법랑질 인공우식병소 재광화 효과 (Effect of Silver Diamine Fluoride and Sodium Fluoride Varnish on Remineralization in Artificially Induced Enamel Caries: An in vitro Study)

  • 김소영;이상호;이난영;지명관
    • 대한소아치과학회지
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    • 제47권3호
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    • pp.266-276
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    • 2020
  • 이 연구의 목적은 법랑질 인공우식병소에서 silver diamine fluoride (SDF)와 sodiun fluoride (NaF) 바니쉬의 재광화 효과를 비교하는 것이다. 소의 절치를 이용해 인공적으로 법랑질 초기 우식병소를 형성하고 38% SDF와 5% NaF 바니쉬를 도포한 후 인공 타액에 3주동안 보관하면서 pH-cycling을 시행하여 법랑질 표면과 3개 층의 깊이에서 micro-CT를 이용하여 무기질 밀도를 측정하고 SEM-EDS를 이용하여 법랑질 표면의 미세구조를 분석함으로써 두 제제의 재광화 효과를 비교, 평가하였다. 38% SDF군와 5% NaF 바니쉬군 모두 탈회된 법랑질의 무기질 밀도와 정상수준으로 재광화된 법랑질의 부피는 시간 경과에 따라 21일까지 지속적으로 증가하였다. 38% SDF군은 5% NaF 바니쉬군보다 법랑질의 모든 깊이와 경과한 시간대에서 무기질 밀도 증가량(△HUV) 및 정상수준으로 재광화된 법랑질의 부피 모두 컸다(p = 0.001). SEM을 이용해 관찰한 재광화된 법랑질 표면은 38% SDF군이 5% NaF 바니쉬군에 비해 더 부드러웠다. SEM 사진상에서 38% SDF를 도포한 법랑질 표면에서 은 화합물 침착이 관찰되었으며 EDS 분석에서는 은 이온이 검출되었다. 이상의 연구 결과를 종합하면 38% SDF의 법랑질 인공우식병소에서의 재광화 효과는 5% NaF 바니쉬보다 더 큼을 알 수 있었으며 이러한 결과는 앞으로 SDF가 진행된 우식의 처치에 있어서도 중요한 역할을 할 수 있을 것으로 사료된다.