• 제목/요약/키워드: Material alteration

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Alteration of Physical Properties of Nanoparticle Embedded liquid Crystal Causing the Enhancement of the Performance of LCDs

  • Kobayashi, Shunsuke;Kineri, Tohru;Takatoh, Kohki;Akimoto, Mitsuhiro;Hoshi, Hajime;Nishida, Naoto;Toshima, Naoki;Sano, Satoru
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1473-1476
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    • 2008
  • Doping the nanoparticles of Pd, p-$BaTiO_3$, $SiO_2$ and MgO into LCs alters their physical properties such as $K_{ii}$, $\Delta\varepsilon$, ${\Delta}n$, $\gamma_1$ and $T_{NI}$. Except for $K_{33}$, all these parameters decreases and thus bring the reduction of operating voltage and/or response times.

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외상성 관절염 진행에 따른 경골 골단 해면골에서의 골 미세구조 변화 패턴 추적 관찰 (Longitudinal Tracking of Alteration Pattern on Trabecular Bone Microarchitecture at Tibial Epiphysis Induced by Post Traumatic Osteoarthritis Over Time)

  • 이주형;전경진;이권용;김대준;김한성;임도형
    • 대한기계학회논문집B
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    • 제36권11호
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    • pp.1081-1090
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    • 2012
  • 외상성 관절염 발생시 슬관절에서의 해면골 미세구조 변화 특성에 대한 연구는 부족한 실정이다. 따라서 본 연구에서는 생체 내 미세 단층 촬영을 통해, 소동물(SD rat; 10 마리)의 경골 골단 해면골 미세구조 변화패턴을 연속적으로 추적 관찰하여 정량적으로 분석하였다. 외상성 관절염 군(5 마리)에는 전방십자인대절제술을 실시하였고, 정상군(5 마리)에는 아무런 외과적 처치를 가하지 않았다. 외상성 관절염군은 정상군과 비교시 수술후 8 주까지 약 4-16%의 유의한 골 미세구조 차이를 나타내었다(P<0.05). 동일 기간 동안 골 밀집 정도 및 골 형성 정도는 5-15% 정도로 유의한 차이를 나타내었다(P<0.05). 본 연구는 외상성 관절염 발생에 의한 경골 골단 해면골의 골 미세구조 변화 특성 기준 정립 및 외상성 관절염의 이해와 치료에 도움이 될 것으로 기대된다.

사회 변동에 따른 범죄의 행태적 변화에 대한 고찰 - 1970년대 이후 한국의 범죄 변화 추이를 중심으로 - (A Study on the Crime Transition about Social Environment Evolution)

  • 공배완
    • 시큐리티연구
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    • 제15호
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    • pp.7-27
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    • 2008
  • 사회범죄는 갈수록 다양화 광역화 전문화 지능화 무차별화 되어가는 양상을 보이고 있다. 사회가 발전하고 국민소득이 향상될수록 사회갈등요인과 범죄가 줄어들 것이라는 예측과는 달리 오히려 범죄의 양상도 사회발전과 더불어 더욱 다양화 전문화되면서 발전되어가는 경향을 보이고 있다. 이러한 현상은 사회발전과 범죄의 비례적 관계로 설명되어질 수 있고, 이는 자본주의의 발달과 사회의 발전이 밀접한 연관성을 갖기 때문으로 분석된다. 이에 따라 본 연구는 양자 간의 상관관계에 대해 역사적인 과정을 통한 실질적인 검증과 사실관계의 규명을 논하고 있다. 따라서 본 연구의 내용은 크게 세부분으로 나누어서 분석하고 있다. 첫째, 산업화의 진행과정에서 나타나는 범죄의 유형 및 행태와 이에 대한 사회적인 구조를 사회학적인 관점에서 분석하고 있다. 둘째, 산업사회 이후의 정보화 시대가 도래되면서 나타나는 새로운 범죄의 모습을 사회적으로 분석하고 있다. 마지막 단락에서는 사회의 변동에 따른 범죄의 행태적 변화에 대한 전반적인 분석을 하고 있으며, 사회변동은 결국 범죄의 변화를 초래한다는 상관관계를 입증하고 있다.

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벤토나이트의 열수변질특성에 따른 중금속의 거동 특성 : 광물성 약재로의 활용 (Behavior of Heavy Metals Studies on the Hydrothermal Alteration Characteristics of Bentonite; Use as Medicinal Mineral)

  • 김선옥;왕수균
    • 자원환경지질
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    • 제56권3호
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    • pp.229-238
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    • 2023
  • 전통적인 광물성 약재로서 활용되어온 석지의 한 종류인 벤토나이트는 다양한 약리 활성을 가지고 있어 한의학에서는 황달, 설사, 지혈 등의 치료제로 쓰이며, 현대 의학에서는 제산제, 위장관보호제, 지사제 등의 의약품 원료 및 의약품 첨가제로 활용하고 있다. 국내에서 생산되는 벤토나이트는 포항, 경주 일대에 분포하는 제3기 화산쇄설물이 속성작용 또는 열수변질작용을 받아 생성되었다. 주로 제지용, 페인트용, 토목용, 주물용, 동물사료용 등의 산업적 용도로 사용하고 있으며, 최근 화장품 및 의약품으로 활용하기 위해 기술을 개발하고 있다. 이 연구에서는 경주 감포 지역과 포항 영일 지역에서 산출되는 벤토나이트 40종와 21종을 대상으로 주성분, 미량원소 분석을 실시하여, 산지별 벤토나이트의 지구화학적 특성을 파악하였고, 포항, 경주 일대에 분포하는 벤토나이트 광상의 생성환경별 유형을 분류하였다. 연구 결과, 연구 지역의 벤토나이트는 현무암질 암석이 열수 유체로부터 알칼리 성분들이 제거되는 이질화작용을 받아 생성되었으며, 이는 AI-CCPI 변질지수에서도 확인할 수 있었다. 또한 산지별 벤토나이트의 열수 변질과 중금속 원소(Pb, Cr, As)의 거동 특성과에는 상관관계가 있음을 알 수 있었다.

Extracellular Matrix of Fresh and Cryopreserved Porcine Aortic Tissues

  • Shon, Yun-Hee
    • BMB Reports
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    • 제30권2호
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    • pp.106-112
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    • 1997
  • The effect of cryopreservation on extracellular matrix was studied with the ultimate objective of permiting a prediction of the tendency of aorta conduit tissue to calcify following transplantation. Cryopreserved and fresh porcine aorta conduit tissues were extracted using guanidine-hydrochloride (Gdn-HCl) followed by sequential digestion of the tissues with collagenase, elastase, and papain. Glycosaminoglycans (GAGs) of the proteoglycans (PGs) were isolated and quantitated. Gdn-HCl extracted about 61% and 62% of the total GAG (proteoqlycan) material from cryopreserved and fresh tissues, respectively. Collagenasesolubilized proteoglycans from Gdn-HCl extracted tissue represented 20% and 13%, respectively, of the total GAGs present in cryopreserved and fresh tissues. Subsequent elastase hydrolysis of collagenase-digested tissue released about 11% of total GAGs from cryopreserved tissue and 16% from fresh tissue. The remaining 8%, from cryopreserved tissue, and 9%, from fresh tissue, of the total GAGs were obtained after using a papain hydrolysis. There was essentially no difference between fresh and cryopreserved tissues in the relative distribution of proteoglycans in the extracts and digestions except in the initial digestion step where more proteoglycans were obtained from collagenase solubilization of cryopreserved tissue than fresh tissue (p<0.05). The histologic status of the fresh and cryopreserved porcine aortic conduit did not differ markedly. The normal tissue architecture was not affected markedly by the cryopreservation procedure as neither alteration of elastic structure, fibrous proteins nor alteration of nuclear distribution or smooth muscle cell morphology was detected. Quantitative tissue mineral studies revealed that the mean calcium content of the cryopreserved aorta conduit tissue $(165{\pm}3\;{\mu}g/g\;wet\;tissue)$ was higher than that of the fresh tissue $(105{\pm}4\;{\mu}g/g\;wet\;tissue)$ $(p<0.05)$. The mean phosphorus content was $703{\pm}35\;{\mu}g$ wet tissue from cryopreserved tissue and $720{\pm}26\;{\mu}g$ wet tissue from fresh tissue. The study indicates that there is no significant alteration in the distribution of PGs in properly cryopreserved tissue, but the total calcium level appears to be increased in tissue cryopreserved by the cryopreservation process used in this study.

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Establishment of the Repair Cycle of the Components of the Apartment Housing

  • Lee, KangHee;Ahn, YongHan;Chae, Chang-U
    • KIEAE Journal
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    • 제14권2호
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    • pp.69-75
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    • 2014
  • Building has been deteriorated over the year after construction. The deterioration has caused to hinder the living condition and to decrease the building value. Thus, it is important to prevent or delay the building deterioration as well as to proceed the maintenance. The long-term repair program for the apartment in Korea plays a key role to make the repair plan after construction and to assure the function decent. This is not flexible to the change of the material and component because the program is provided by the Korean-law. Many items are omitted in the long-term program so that the maintenance experts face many difficulties to make a repair plan. In this paper, it aimed at providing the repair cycle and repair ratio according to the repair scope, which are not provided in the current program. This study shows that the repair ratio is presented with quartile range in 25%, 50%, 75% and 100%. This has an advantage to take an overall look in repair items. Under this presentation of the repair ratio, each item has a unique repair value. Second, the repair scope is divided into partly repair, fully repair, partly alteration and fully alteration. If a fully repair has a repair ratio close to 100%, it would mean that a fully repair is a fully alteration. Third, the short repair cycle means that it requires to maintain the function or performance of the components in a short term.

진동 억제를 위한 Wafer Packing Box 재료 최적화 (Wafer Packing Box for Vibration Suppression Material Optimization)

  • 윤재훈;허장욱;이일환
    • 반도체디스플레이기술학회지
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    • 제21권2호
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    • pp.51-56
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    • 2022
  • Recently, the demand for semiconductors is expanded to various industries, and the use of high-quality and high-performance chips is increasing. With the trend, the diameter magnification and high integration of the semiconductor wafers are mandatory. As a result, there is a growing demand for the productivity improvement and the surface precision. There have been many studies on the stabilization of the wafer manufacturing processes in order to satisfy those specifications. Many complaints have been appealed by the wafer buyers that there are many unacceptable wafers with surface defects and foreign material adhesion which are caused by the vibrations during transportation. This study intends to derive the material improvement of the packing box of the wafers to suppress the vibrations of the box, and eventually to reduce the surface defects and the foreign material adhesion. The result shows that optimal material can substantially decrease the vibration of the packing box.

Bandgap Alteration of Transparent Zinc Oxide Thin Film with Mg Dopant

  • Salina, M.;Ahmad, R.;Suriani, A.B.;Rusop, M.
    • Transactions on Electrical and Electronic Materials
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    • 제13권2호
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    • pp.64-68
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    • 2012
  • We have successfully demonstrated a bandgap alteration of transparent zinc oxide (ZnO) thin film with Mg dopant by using sol-gel spin coating technique. By increasing the dopant from 0 to 30 atomic percent (at.%), a decrement value in the cutoff is observed, where the absorption edge shifts continuously to the shorter wavelength side, towards 300 nm. This resulted in a significant bandgap increment from 3.28 to 3.57 eV. However, the transmittance of the thin film at 350-800 nm gradually downgraded, from 93 to 80 % which is most probably due to the grain size that becomes bigger, and it also affected the electrical properties. The decrement from 45 to 0.05 mA at +10 V was observed in the I-V characteristics, concluding the significant relationship; where higher optical bandgap materials will exhibit lower conductivity. These findings may be useful in optoelectronics devices.

Alteration of Genetic Make-up in Karnal Bunt Pathogen (Tilletia indica) of Wheat in Presence of Host Determinants

  • Gupta, Atul K.;Seneviratne, J.M.;Bala, Ritu;Jaiswal, J.P.;Kumar, Anil
    • The Plant Pathology Journal
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    • 제31권2호
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    • pp.97-107
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    • 2015
  • Alteration of genetic make-up of the isolates and mono-sporidial strains of Tilletia indica causing Karnal bunt (KB) disease in wheat was analyzed using DNA markers and SDS-PAGE. The generation of new variation with different growth characteristics is not a generalized feature and is not only dependant on the original genetic make up of the base isolate/monosporidial strains but also on interaction with host. Host determinant(s) plays a significant role in the generation of variability and the effect is much pronounced in monosporidial strains with narrow genetic base as compared to broad genetic base. The most plausible explanation of genetic variation in presence of host determinant(s) are the recombination of genetic material from two different mycelial/sporidia through sexual mating as well as through parasexual means. The morphological and development dependent variability further suggests that the variation in T. indica strains predominantly derived through the genetic rearrangements.

초정밀 가공기용 마이크로 스테이지의 힌지 형상에 따른 안정성 해석 (Stability Analysis According to Hinge Type Alteration on Micro Stage for Micro Cutting Machine)

  • 김재열;곽이구;심재기;안재신;송경석;한재호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.993-998
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    • 2002
  • Ultra precision processing technology is the field which is seriously protected its technology by advanced nations. Because of this reason, this technology is very difficult to supply for domestic companies, also domestic companies are revealed the limit of technology development by itself. And then, those are depend on the technology development of advanced nation, domestic companies are not conquer application step with already developed parts. Of course, some cases of its research are succeed. those are included element technology, system technology and so on, for development of ultra precision processing system. To conquer technology holding ultra precision processing accuracy of no level, active research are needed. In this paper, stability of ultra precision cutting unit is analyzed, this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for un it control.

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