• 제목/요약/키워드: successive synthesis

검색결과 65건 처리시간 0.025초

Synthesis and Exploitation in Solar Cells of Hydrothermally Grown ZnO Nanorods Covered by ZnS Quantum Dots

  • Mehrabian, Masood;Afarideh, Hossein;Mirabbaszadeh, Kavoos;Lianshan, Li;Zhiyong, Tang
    • Journal of the Optical Society of Korea
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    • 제18권4호
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    • pp.307-316
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    • 2014
  • Improved power conversion efficiency of hybrid solar cells with ITO/ZnO seed layer/ZnO NRs/ZnS QDs/P3HT/PCBM/Ag structure was obtained by optimizing the growth period of ZnO nanorods (NRs). ZnO NRs were grown using a hydrothermal method on ZnO seed layers, while ZnS quantum dots (QDs) (average thickness about 24 nm) were fabricated on the ZnO NRs by the successive ionic layer adsorption and reaction (SILAR) technique. Morphology, crystalline structure and optical absorption of layers were analyzed by a scanning electron microscope (SEM), X-ray diffraction (XRD) and UV-Visible absorption spectra, respectively. The XRD results implied that ZnS QDs were in the cubic phase (sphalerite). Other experimental results showed that the maximum power conversion efficiency of 4.09% was obtained for a device based on ZnO NR10 under an illumination of one Sun (AM 1.5G, $100mW/cm^2$).

A New Approach of BK products of Fuzzy Relations for Obstacle Avoidance of Autonomous Underwater Vehicles

  • Bui, Le-Diem;Kim, Yong-Gi
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제4권2호
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    • pp.135-141
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    • 2004
  • This paper proposes a new heuristic search technique for obstacle avoidance of autonomous underwater vehicles equipped with a looking ahead obstacle avoidance sonar. We suggest the fuzzy relation between the sonar sections and the properties of real world environment. Bandler and Kohout's fuzzy relational method are used as the mathematical implementation for the analysis and synthesis of relations between the partitioned sections of sonar over the real-world environmental properties. The direction of the section with optimal characteristics would be selected as the successive heading of AUVs for obstacle avoidance. For the technique using in this paper, sonar range must be partitioned into multi equal sections; membership functions of the properties and the corresponding fuzzy rule bases are estimated heuristically. With the two properties Safety, Remoteness and sonar range partitioned in seven sections, this study gives the good result that enables AUVs to navigate through obstacles in the optimal way to goal.

Synthesis and Guest Binding Properties of Cyclophanes Containing Two Benzo[b]furan Rings

  • Park, Kwang-Hee;Kim, Sun-Hyuk;Park, Joon-Woo
    • Bulletin of the Korean Chemical Society
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    • 제25권11호
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    • pp.1635-1640
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    • 2004
  • The cyclophanes 1a-d containing two benzo[b]furan rings connected by various bridges have been prepared and their binding behaviors with N-benzylphenethylammonium cation 2 were examined by NMR titration method. The successive alkylation reactions of 4-hydroxyl groups and then 2-hydroxyl groups of 2,4-dihydroxybenzophenonse gave macrocycles 5a-c. Photoirradiation of the macrocycles 5a-c with 350 nm mercury lamp followed by dehydration afforded the cyclophanes 1a-c. Hydrolysis of two ester groups pendant on a bridge of 1b produced the carboxyl group-containing cyclophane 1d. The cyclophane 1a having a p-xylene bridge showed 1 : 1 binding with 2 with the binding constant of $36{\pm}6M^{-1}$ in 3 : 1 $CDCl_3$/methanol-$d_4$ solvent, while 1b and 1c which have neutral flexible bridges exhibited no appreciable binding with 2. The disodium salt of 1d showed much higher binding affinity for 2 forming 1 : 1 and 1 : 2 complexes.

Prospect of plant molecular cytogenetics in the 21st century

  • Mukai, Yasuhiko
    • 한국생명과학회:학술대회논문집
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    • 한국생명과학회 2003년도 제40회 국제학술심포지움
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    • pp.14-27
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    • 2003
  • The genomes of Arabidopsis and rice have been fully sequenced. Genomic sequencing provides global information about genome structure and organization. A comprehensive research account of our recent studies conducted on genome painting, comparative genomics and genome fusion is provided in order to project the prospects of plant cytogenetic research in post-genomics era. Genome analysis by GISH using genome painting is demonstrated as an excellent means suitable for visualization of a whole genome, since total genomic DNA representing the overall molecular composition of the genome is used as a probe. FISH on extended DNA fibers has been developed for high-resolution FISH and has contributed to determining the copy number and order of genes. We have also mapped a number of genes involving starch synthesis on wheat chromosomes by FISH and compared the position of these genes on linkage map of rice. Macro synteny between wheat and rice can be observed by comparing the location of these genes in spite of the fact that the size of DNA per chromosome differs by 20 fold in two. Moreover, to approach our goal towards making bread and udon noodles from rice flour in future by incorporating bread making and the noodle qualifies in rice, we have been successful in introducing large genomic DNA fragments containing agronomically important genes of wheat into a rice by successive introduction of large insert BAC clones, there by expanding genetic variability in rice. We call this method genome fusion.

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간에서의 RNA, 단백질 생합성에 미치는 인삼성분의 생화학적 연구 (Biochemical Studies of Ginseng Saponin on RNA and Protein Biosynthesis in the Rat Liver)

  • Oura Hikokichi
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1988년도 학술대회지
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    • pp.1-10
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    • 1988
  • 조사포닌을 복강내 투여하면 1) 핵내의 RNA polymerase의 활성도, 2) 핵내의 RNA합성, 3) 세포질의 RNA합성,4) 세포질내의 폴리리보좀 함량, 5) in vitro 상태에서의 쥐간의 polysome과 micro-some으로의 아미노산 유입율, 6) 방사능 표지된 아미노산의 혈청 단백질로의 유입율이 증가하였음을 과거에 보고 한 바 있으며 또한 4주간 조사포닌을 투여한 쥐에서 적출한 간세포를 전자 현미경으로 조사한 결과, 조면 소포체가 상당히 증가하였으며 초원심분리기로서 막에 결합한 ribosome에서의 polysome함량의 증가를 확인하였다. 최근 streptozotocin으로 유도한 단백질 결핍성 당뇨병 쥐에 $Rb_2$를 계속적으로 주사한 결과 blood urea nitrogen과 간내의 urea 농도가 현저히 감소하였으며 혈청내의 총단백질과 알부민의 농도가 대조군의 수치에 비하여 증가한 반면 간내의 RNA와 총 ribosome, 막에 결합된 ribosome의 함량이 증가하였다. 또한 $Rb_2$투여로 혈청내의 총단백질로의 방사능 표지 전구물질의 유입량이 증가하였으며 당뇨쥐에서의 질소균형을 개선시켰다. 이러한 실험적 결과에 근거하여 인삼 사포닌은 대사를 촉진시키고 RNA, 단백질 합성 등을 촉진하는 것으로 생각된다.

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흑한우와 한우 및 수입우를 판별하기 위한 multiplex PCR 기술 (PCR Technique for Determining Jeju Black Cattle, Hanwoo and Imported Beef)

  • 김찬수;고정문;차현철;박중국;정준
    • 생명과학회지
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    • 제24권8호
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    • pp.910-914
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    • 2014
  • 본 연구는 현행 한우확인시험법에 이용되는 Microsatellite (MS)와 소의 유전형질 중 품종 판별에 주로 이용되는 Melanocortin Receptor 1 (MC1R) 유전자상의 Single Nucleotide Polymorphism (SNP)를 분석하여 설계한 Primer를 Multiplex PCR을 활용하여 소의 품종을 판별하였다. MC1R 유전자형은 $E^D$, $E^+$, e형의 3Type으로 나뉘며 $E^D/E^D$, $E^D/E^+$, $E^D/e$, $E^+/E^+$, $E^+/e$, e/e의 6가지 유전자형을 가진다. $E^D$유전자형은 외래종이 지닌 유전자형으로 $E^D/E^D$, $E^D/E^+$, $E^D/e$이 이에 속하며, e유전자형은 한우가 지닌 유전자형으로 e/e의 유전자형을 가진다. 흑한우의 경우 $E^D$, $E^+$, e의 모든 유전자형을 가지고 있으나 이는 교잡에 의해 나타난 것으로 보이며 $E^+$유전자형이 흑한우 고유의 유전자형으로 추정되어 본 연구에서는 이에 따라 $E^+/E^+$, $E^+/e$의 유전자형을 흑한우로 분류하였다. 그러나 $E^D$, $E^+$의 경우 단순 PCR기법만으로는 그 판별에 어려움이 있어, MS Maker를 활용한 다형성 분석을 통해 흑한우와 수입우를 판별할 수 있는 새로운 Primer를 설계하였으며, 이를 통해 소의 품종을 판별하였다.

R-Stereoselective Amidase from Rhodococcus erythropolis No. 7 Acting on 4-Chloro-3-Hydroxybutyramide

  • Park, Ha-Ju;Uhm, Ki-Nam;Kim, Hyung-Kwoun
    • Journal of Microbiology and Biotechnology
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    • 제18권3호
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    • pp.552-559
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    • 2008
  • Ethyl (S)-4-chloro-3-hydroxybutyrate is an intermediate for the synthesis of Atorvastatin, a chiral drug used for hypercholesterolemia. A Rhodococcus erythropolisstrain (No.7) able to convert 4-chloro-3-hydroxybutyronitrile into 4-chloro-3-hydroxybutyric acid has recently been isolated from soil. This activity has been regarded as having been caused by the successive actions of the nitrile hydratase and amidase. In this instance, the corresponding amidase gene was cloned from the R. erythropolis strain and expressed in Escherichia coli cells. A soluble active form of amidase enzyme was obtained at $18^{\circ}C$. The Ni column-purified recombinant amidase was found to have a specific activity of 3.89 U/mg toward the substrate isobutyramide. The amidase was found to exhibit a higher degree of activity when used with mid-chain substrates than with short-chain ones. Put differently, amongst the various amides tested, isobutyramide and butyramide were found to be hydrolyzed the most rapidly. In addition to amidase activity, the enzyme was found to exhibit acyltransferase activity when hydroxyl amine was present. This dual activity has also been observed in other enzymes belonging to the same amidase group (E.C. 3.5.1.4). Moreover, the purified enzyme was proven to be able to enantioselectively hydrolyze 4-chloro-3-hydroxybutyramide into the corresponding acid. The e.e. value was measured to be 52% when the conversion yield was 57%. Although this e.e. value is low for direct commercial use, molecular evolution could eventually result in this amidase being used as a biocatalyst for the production of ethyl (S)-4-chloro-3-hydroxybutyrate.

Discussing Architecture and the City as a Metaphor for the Human Body : From Marcus Vitruvius Pollio, Leon Battista Alberti, Andrea Palladio to Other Renaissance Architects

  • Kim, Young Jae
    • Architectural research
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    • 제18권1호
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    • pp.1-12
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    • 2016
  • This thesis explores Vitruvius and his impact upon other Renaissance architects who compare a city to a building or a building to a city, who match the city and the building into a human body, and who develop their own works. The objective of this study is to furnish an interpretation of their theory and practice through their literature and designs. In this point of view, this article takes notice of Vitruvius's six concepts coined from venustas and divides them into two parts: i.e. aesthetic quality (ordinatio, dispositio, and distributio) and technical activity (eurythmia, symmetria, and $d{\acute{e}}cor$) each. This thesis indicates that Vitruvius's successive impacts from the concepts bring about concrete design principles through proportional measurements, placing together, and hierarchic values for the former, as well as appropriate use through beautiful look, symmetrical harmony, and appropriate uses for the latter, tracking notions between a city as a house and vice versa, and either the ideas of the house or the city in the synthesis of the human body, which follows the perfect number and module based on the human body. The thesis shows that the representations of architecture and the city take place with the form of a circle and a square that express the religious belief and the cosmos, substantiating the connection between the proportions of the human body and numbers, and ultimately satisfying a concept of centrality, which is slowly extended to the enclosed plaza at the urban level from chambers, atrium, and corridors at the residence level.

폐 패각과 정유 폐촉매를 사용한 Tricalcium Aluminate 클링커의 합성에 관한 연구 (Study on the Synthesis of Tricalcium Aluminate Clinker from Waste Shell and Spent Oil-Refining Catalyst)

  • 이건호;송태웅
    • 한국세라믹학회지
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    • 제41권12호
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    • pp.933-938
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    • 2004
  • [ $3CaO{\cdot}Al_{2}O_3$ ] 클링커 제조 원료로서의 굴 패각과 정유 폐 촉매의 사용 가능성과 이들 조합물의 클링커 소성성 및 광물 생성거동을 광물상과 미구조 관찰을 중심으로 확인하였다. 굴 패각에 함유된 불순물은 클링커의 합성에 영향을 미치지 않았고 이들 조합물은 비교적 저온에서 $12CaO{\cdot}7Al_{2}O_3$를 생성한 후 다시 CaO와의 반응으로 $3CaO{\cdot}Al_{2}O_3$를 생성하므로 $1400^{\circ}C$에서의 1회 소성으로 클링커 합성이 가능하였다. 그 이상의 온도에서는 분해용융이 진행되었으며 동일한 소성 조건에서 알루미나원으로 수산화알루미늄을 사용할 경우에는 $3CaO{\cdot}Al_{2}O_3$의 생성이 완료되기 전에 용융되어 클링커의 합성이 불가능하였다.

은 카바메이트 복합체를 이용한 라디칼 중합에 의한 은/폴리스티렌 나노복합체의 제조 (Preparation of Silver/Polystyrene Nanocomposites by Radical Polymerization Using Silver Carbamate Complex)

  • 박헌수;박형석;공명선
    • 폴리머
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    • 제34권2호
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    • pp.144-149
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    • 2010
  • Ag/polystyrene(PS) 나노복합체를 110 $^{\circ}C$의 가열법에 의하여 silver 2-ethylhexylcarbamate(Ag-CB) 복합체의 환원과 동시에 라디칼 중합을 진행하여 제조하였다. 또한, 이러한 전통적인 가열법과는 대조적으로 마이크로파를 조사하여 스티렌 단량체의 중합이 진행됨이 없이 은 나노입자가 잘 분산된 콜로이드 스티렌 용액을 제조할 수 있었다. 이렇게 단지 마이크로파를 조사하여 은 나노입자를 제조하는 방법은 반응기 내의 전체 용액 속에서 균일하고 빠르게 진행되어 매우 입자가 작고 균일한 은 나노콜로이드 용액을 제조할 수 있었다. 또한, 연속적으로 얻어진 은 나노입자를 포함하는 단량체 용액을 라디칼 중합시킴으로써 PS 고분자 매트릭스에 은 나노입자가 잘 분산된 Ag/PS 나노복합체를 얻을 수 있었다. Ag/PS(0.1/100) 나노복합체는 Ag/PS(4.0/100)를 마스터배치로 사용하여 용융-혼합 방법에 의하여 성공적으로 제조할 수 있었으며 그러한 나노복합체를 UV-VIS spectroscopy, TEM, 그리고 XRD를 이용하여 확인하였다.