• Title/Summary/Keyword: HOMO

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Production and Heat-Stable Characteristics of Emulsion Made from Buckwheat Sprout Extracts (메밀 싹 추출물 에멀젼의 제조 및 에멀젼의 열 안정 특성)

  • Cha, Bo-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.10
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    • pp.1549-1554
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    • 2014
  • This study analyzed the production and heat stability of an emulsion made from buckwheat sprout extracts with high rutin content. To obtain high rutin contents, buckwheat was sprouted and the polyphenols and rutin were extracted from buckwheat sprouts. Concentrated extracts were made into an emulsion using a homo mixer and hydraulic homogenizer, after which heat stability was analyzed. The polyphenol contents were highest in ground sprouts grown for 8 days (10.66 mg/g), which was 10 times higher than those of buckwheat seeds. Extraction with 50% ethanol after blanching was the most effective method for obtaining extracts with higher polyphenol content and rutin content. Extracts were concentrated up to 60% soluble solid content and then emulsified using a homo mixer and hydraulic homogenizer. Heat stability of the emulsion passed through the hydraulic homogenizer was slightly higher than that made using the homo mixer. The heat stability of the emulsion was more strongly affected by heating time than temperature. In conclusion, the buckwheat concentrate emulsion passed through the hydraulic homogenizer was more heat stable than buckwheat extract alone.

Synthesis and Photovoltaic Properties of Copolymers with Fluorinated Quinoxaline and Fluorene Moiety (Fluorine이 도입된 Quinoxaline과 Fluorene 골격을 가진 고분자의 합성 및 특성분석)

  • Song, Suhee;Choi, Hyo Il;Shin, In Soo;Park, Seong Soo;Lee, Gun Dae;Park, Sung Heum;Jin, Youngeup
    • Applied Chemistry for Engineering
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    • v.27 no.5
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    • pp.467-471
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    • 2016
  • New electron deficient moiety, 6,7-difluoro-2,3-dihexylquinoxaline, was developed for the push-pull type copolymer for organic photovoltaics (OPVs). The PFDTQxF with lower HOMO energy level was synthesized using fluorene and 6,7-difluoro- 2,3-dihexylquinoxaline by Suzuki polymerization. The PFDTQxF thin film shows two absorption peaks at 368 and 493 nm. The HOMO and LUMO energy levels of PFDTQxF are calculated -5.55 and -3.91 eV, respectively. The device comprising PFDTQxF showed a $V_{OC}$ value of 0.47 V, a $J_{SC}$ value of $4.48mA/cm^2$, and a FF of 0.32, which yielded PCE of 0.78%, under the illumination of AM 1.5.

Interfacial Charge Transport Anisotropy of Organic Field-Effect Transistors Based on Pentacene Derivative Single Crystals with Cofacial Molecular Stack (코페이셜 적층 구조를 가진 펜타센 유도체 단결정기반 유기트랜지스터의 계면 전하이동 이방성에 관한 연구)

  • Choi, Hyun Ho
    • Journal of Adhesion and Interface
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    • v.20 no.4
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    • pp.155-161
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    • 2019
  • Understanding charge transport anisotropy at the interface of conjugated nanostructures basically gives insight into structure-property relationship in organic field-effect transistors (OFET). Here, the anisotropy of the field-effect mobility at the interface between 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) single crystal with cofacial molecular stacks in a-b basal plane and SiO gate dielectric was investigated. A solvent exchange method has been used in order for TIPS-pentacene single crystals to be grown on the surface of SiO2 thin film, corresponding to the charge accumulation at the interface in OFET structure. In TIPS-pentacene OFET, the anisotropy ratio between the highest and lowest measured mobility is revealed to be 5.2. By analyzing the interaction of a conjugated unit in TIPS-pentacene with the nearest neighbor units, the mobility anisotropy can be rationalized by differences in HOMO-level coupling and hopping routes of charge carriers. The theoretical estimation of anisotropy based on HOMO-level coupling is also consistent with the experimental result.

Metaverse as a future living environment of Homo Culturalis (문화적 인간의 미래 생활환경으로서 메타버스)

  • Lee, Arum;Oh, Min Jung
    • Journal of the Korea Convergence Society
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    • v.13 no.2
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    • pp.167-176
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    • 2022
  • In this paper, the metaverse is viewed as a future space for the living environment of Homo Culturalis. Although the metaverse is perceived as a digital 'virtual' space, it should be understood as an extension of the real space. A human dreams of a reincarnation in the digital space, but a human has a body that cannot be completely separated from the physical environment. This means that human activities are not disconnected from reality and more specifically the human existence ought to be found in the socio-cultural context of reality. If the way of life in Metaverse becomes increasingly common, humans should be able to access this metaverse as a reality. Therefore, in this paper, the metaverse that creates the world of creation, play, and empathy, becomes considered as the world of human life of Homo Culturalis, where the realization of human desires and desires in that world are made.

Solid-State High-Resolution 1H-NMR Study for Ammonia Borane of Hydrogen Storage Material

  • Han, J.H.;Lee, Cheol-Eui;Kim, Se-Hun;Kim, Chang-Sam;Han, Doug-Young
    • Journal of the Korean Magnetic Resonance Society
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    • v.14 no.1
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    • pp.38-44
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    • 2010
  • In liquids NMR, $^{1}H$ is the most widely observed nucleus, which is not the case in solids NMR. The reason is due to the strong homo-dipolar interactions between the hydrogen atoms which mask the useful chemical shift information. Therefore we must remove the strong homo-dipolar interactions in order to get structural information, which can be investigated by the isotropic chemical shift. There are two ways of obtaining it. One is the ultra-fast MAS of ca. 70 kHz spinning speed, which has become available only recently. The other way is devising a pulse sequence which can remove the strong homo-dipolar interaction. In the latter way, MAS with a moderate spinning rate of a few kHz, is enough to remove the chemical shift anisotropy. In this report, 1D-CRAMPS and 2D MASFSLG techniques are utilized and their results will be compared. This kind of highresolution $^{1}H$ NMR for solids, should become a valuable analytical tool in the understanding and the developing of a new class of hydrogen storage materials. Here ammonium borane $-NH_{3}BH_{3}$, whose hydrogen content is high, is used as a sample.

Analysis of the characteristic and types of 'Homo Mutant' in Science Fiction (SF 속 '호모 뮤턴트'의 특성과 유형에 관한 연구)

  • Kang, Bora
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.135-140
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    • 2009
  • The characteristic of mutant has long history, which is shown in various science fictions. There are different types and characters like Satyrs from Ancient Greek to superheroes in present. In fact, however, mutant as a cultural content has not been discussed sufficiently in Korea, even if related analyses were required indeed. In the thesis the characteristic and types of 'Homo Mutant' will be introduced and analyzed in many aspects and look for the reason why 'Homo Mutant' can be revealed and apply for further possibilities.

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Expression of Δ-desaturase Gene in a Recombinant Pichia pastoris GS115 Strain and Its Activity (재조합 Pichia pastoris GS115에서 Δ-desaturase의 발현과 그 활성)

  • Bae, Kyung-Dong
    • KSBB Journal
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    • v.26 no.6
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    • pp.557-560
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    • 2011
  • It has been known that Δ-desaturase (TAD5) in the biosynthetic pathway of long chain polyunsaturated fatty acids of Thraustochytrium aureumis responsible for the conversion of di-homo-${\gamma}$-linolenic acid (C20:4) into arachidonic acid (C20:4). The genetic sequence analysis on TAD5 of Thraustochytrium aureum ATCC34304 used in this study showed that it has two amino acid changes when compared to that of Thraustochytrium aureum TAD5 first reported in 2003. Accordingly, Thraustochytrium aureum ATCC34304 TAD5 was named TAD5_1. TAD5_1-inserted methylotropic Pichia pastoris was prepared and then cultured with a precursor fatty acid, di-homo-${\gamma}$-linolenic acid. GC analysis confirmed that a certain amount of the precursor fatty acid was converted into arachidonic acid. In this study, not only a recombinant Pichia pastoris with the typical activity of ${\Delta}5$-desaturase which plays an essential role in the biosynthesis of LCPUFAs was successfully made but also the preparationpotential of a recombinant Pichia pastoris strain which may synthesize eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that are important in maintaining and improving human's brain function was proposed.

OLED 소자의 효율 개선을 위한 소재 및 구조의 변화에 따른 특성 평가

  • Bae, Il-Ji;Hong, Yeong-Gyu;Yun, Dang-Mo;Sin, Jin-Guk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.227-227
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    • 2014
  • OLED 소자에 사용되는 유기물들은 대부분 전자에 비해 정공의 이동속도가 매우 빨라 소자 효율의 손실이 일어난다. 본 연구에서는 이러한 전하 이동도의 불균형에 의한 OLED 소자 성능의 감소를 개선하기 위해 HBL (hole blocking layer) 물질로 BCP (HOMO : 6.5 eV, LUMO : 2.83 eV)를 도입하였다. 그러나 BCP의 LUMO 값이 약 3 eV를 가지기 때문에 전자의 이동에 영향을 미치는 것으로 예상되어 더 높은 효율을 가지는 소자를 제작하기 위해 host 물질을 상용물질(PGH02)로 교체하였다. PGH02의 HOMO 값은 약 5.86 eV로 소자에 사용된 HTL (hole transport layer)의 HOMO 값(5.54 eV)에 비해 높은 값을 가지기 때문에 HBL의 역할 역시 가능하여 소자의 성능이 상당히 개선되는 것을 확인할 수 있었다. 또한 전하 이동도의 균형을 맞추기 위해 ETL 물질로는 기존에 많이 사용되고 있는 Alq3 (${\mu}{\sim}10-5cm2/Vs$)에 비해 이동도가 10배 이상 빠른 Bebq2 (${\mu}{\sim}10-4cm2/Vs$)를 사용하였다. HTL (hole transport layer) 물질로는 상용물질(LHT 259)를 사용하였고, LHT 259의 전하 이동도는 FET (field effect transistor)를 제작하여 측정하였다. 이를 기반으로 하여 ETL과 HTL의 두께를 조절하여 전하 이동도가 균형을 이루는 OLED 소자를 제작하기 위해 실험을 진행하였다.

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Electrochemical Study for 1,3-Bisdicyanovinylindane

  • Kim, Hyungjoo;Rao, Boddu Ananda;Son, Young-A
    • Textile Coloration and Finishing
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    • v.25 no.2
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    • pp.89-93
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    • 2013
  • The electrochemical study has been enjoyed in many areas of chemistry. Through this approach using electrochemical measurement, empirical HOMO and LUMO values can be calculated by three methods such as absorption measurement, cyclicvoltammetry and computational calculations. In this study, 1,3-bisdicyanovinylindane was prepared and investigated toward its optical properties. The absorption intensities were changed depending on changes of pH. These absorption changes are induced by resonance form of 1,3-bisdicyanovinylindane. The electron delocalization in ${\pi}$ system is related to the resonance form. In according to this electron density distribution and HOMO/LUMO values of 1,3-bisdicyanovinylindane were simulated and calculated by Material Studio 4.3, absorption measurement and cyclicvoltammograms. The 1,3-bisdicyanovinylindane is one of the most attracted acceptor units in D-${\pi}$-A system. This attempt is useful to determine more detailed characteristics of the energy potentials.

Growth and Energy Level Alignment of Pentacene on SiO2 Surfaces before and after OTS Treatment (OTS처리 전후 실리콘산화막 위에서 펜타신의 성장과 에너지준위의 정렬)

  • Kim, J.W.;Lee, Y.M.;Park, Y.
    • Journal of the Korean Vacuum Society
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    • v.17 no.5
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    • pp.394-399
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    • 2008
  • Growth and electronic structure of pentacene film on silicon oxide before and after octadecyltrichlorosilane (OTS) treatment have been studied by photoelectron spectroscopy and photoelectron emission microscopy. On the OTS-treated surface, due to the weak interaction between the substrate and pentacene, the diffusion of pentacene is enhanced and domain size gradually grows, leading to a gradual change of the HOMO offset position. On the bare silicon oxide, the change of the HOMO position is marginal because of relatively strong interaction between the substrate and pentacene from the beginning.