• 제목/요약/키워드: multicomponent

검색결과 251건 처리시간 0.028초

Molecular Layer Deposition of Organic/Inorganic Nanohybrid Dielectrics for OTFTs

  • 이병훈;이광현;임성일;성명모
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.56-56
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    • 2010
  • We report a low-temperature fabrication of organic/inorganic nanohybrid dielectrics for organic thin film transistors. The self-assembled organic layers (SAOLs) were grown by repeated sequential adsorptions of C=C-terminated alkylsilane and metal (Al or Ti) hydroxyl with ozone activation, which was called "molecular layer deposition (MLD)". The $TiO_2$ and $Al_2O_3$ inorganic layers were grown by ALD, which relies on sequential saturated surface reactions resulting in the formation of a monolayer in each sequence and is a potentially powerful method for preparing high quality multicomponent superlattices. The MLD method combined with ALD (MLD-ALD) was applied to fabricate SAOLs-$Al_2O_3$-SAOLs-$TiO_2$ nanohybrid superlattices on polymer substrates at relatively low temperature. The MLD method is an ideal fabrication technique for various flexible electronic devices.

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이중도가니법에 의해 제조된 다성분계 화이버의 광학적ㆍ구조적 특성 (Optical & Structural Properties of multicomponent fiber fabricated by double crucible method)

  • 오영석;이회관;이용수;강원호
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2001년도 추계산학기술 심포지엄 및 학술대회 발표논문집
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    • pp.153-156
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    • 2001
  • 광전자 기술의 발전 및 광 응용 분야의 확대에 따라 광전송치의 개발이 필수적이다. 이에 본 연구에서는 보다 넓은 영역의 광을 투과시키고, UV/VIS/NIR의 파장 영역에서 낮은 광 손실을 갖는 fiber를 제조하기 위하여 SiO₂,PbO를 주성분으로 하고 K₂O, Na₂O, B₂O₃등의 산화물을 적량 배합함으로써 core/clad유리의 제조 및 제조된 유리의 물성을 측정하였다. Core/clad의 match를 고려하여 최적조성을 선정하였으며, 이중도가니법을 이용하여 fiber를 제조하였다. 또한, 제조된 fiber의 구조적 특성을 관찰하였으며, 성형시 조건에 따라 50-200㎛의 직경을 갖는 fiber를 제조할 수 있었다. Fiber의 optical loss는 0.3-1.8㎛에서 측정하였다.

Approximate Nonrandom Two-Fluid Lattice-Hole Theory. General Derivation and Description of Pure Fluids

  • 유기풍;신훈용;이철수
    • Bulletin of the Korean Chemical Society
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    • 제18권9호
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    • pp.965-972
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    • 1997
  • An approximate molecular theory of classical fluids based on the nonrandom lattice statistical-mechanical theory is presented. To obtain configurational Helmholtz free energy and equation of state (EOS), the lattice-hole theory of the Guggenheim combinatorics is approximated by introducing the nonrandom two-fluid theory. The approximate nature in the derivation makes the model possible to unify the classical lattice-hole theory and to describe correctly the configurational properties of real fluids including macromolecules. The theory requires only two molecular parameters for a pure fluid. Results obtained to date have demonstrated that the model correlates quantitatively the first- and second-order thermodynamic properties of real fluids. The basic simplicity of the model can readily be generalized to multicomponent systems. The model is especially relevant to (multi) phase equilibria of systems containing molecularly complex species.

The Emerging Role of Fast MR Techniques in Traumatic Brain Injury

  • Yoo, Roh-Eul;Choi, Seung Hong
    • Investigative Magnetic Resonance Imaging
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    • 제25권2호
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    • pp.76-80
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    • 2021
  • Post-concussion syndrome (PCS) following mild traumatic brain injury (mTBI) is a major factor that contributes to the increased socioeconomic burden caused by TBI. Myelin loss has been implicated in the development of PCS following mTBI. Diffusion tensor imaging (DTI), a traditional imaging modality for the evaluation of axonal and myelin integrity in mTBI, has intrinsic limitations, including its lack of specificity and its time-consuming and labor-intensive post-processing analysis. More recently, various fast MR techniques based on multicomponent relaxometry (MCR), including QRAPMASTER, mcDESPOT, and MDME sequences, have been developed. These MCR-based sequences can provide myelin water fraction/myelin volume fraction, a quantitative parameter more specific to myelin, which might serve as a surrogate marker of myelin volume, in a clinically feasible time. In this review, we summarize the clinical application of the MCR-based fast MR techniques in mTBI patients.

Sex-Gender Differences in Irritable Bowel Syndrome

  • Kim, Young Sun;Kim, Nayoung
    • Journal of Neurogastroenterology and Motility
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    • 제24권4호
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    • pp.544-558
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    • 2018
  • Because of the sex-gender differences that are shown in a diversity of physiological and psychological factors, it can be speculated that the clinical presentation of symptoms as well as treatment strategies in women and men with irritable bowel syndrome (IBS) may differ. Studies have revealed that IBS is more common in women than men. As for the IBS subtype, IBS with constipation is significantly more prevalent among women than men. Sex hormones and gender differences may play important roles in the pathophysiology of IBS. However, its pathophysiologic mechanisms still remain largely unknown, and therapeutic implications are limited. Moreover, women IBS patients have been reported to feel more fatigue, depression, anxiety, and lower quality of life than men IBS patients. Furthermore, there has been evidence of differences in the appropriate treatment efficacy to IBS in men and women, although relatively few men are enrolled in most relevant clinical trials. A more sex-gender-oriented approach in the medical care setting could improve understanding of heterogeneous patients suffering from IBS. An individualized and multicomponent approach including sex and gender issues might help improve the treatment of IBS.

Topological Analysis on the Modulus and Network Structure of Miscible Polymer Blends

  • 손정모;박형석
    • Bulletin of the Korean Chemical Society
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    • 제16권2호
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    • pp.169-180
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    • 1995
  • A topological theory is introduced to extend Tsenoglou's theory to polymer blends having temporary and permanent networks composed of multicomponent polymers which have miscible and flexible chains. The topological theory may estimate the values of free elastic energy, the molecular weight between entanglements, and the equilibrium shear moduli, and it may establish more correctly the topological relations among these physical quantities. Through such introduction of the topological theory, there can be topologically analyzed the mixing law for the rubbery plateau modulus of a fluid polymer blend, and there can be considered the topological relationship to the equilibrium modulus of an interpenetrating polymer network containing trapped entanglements and dangling segments. The theoretically predictive values are compared and show good agreement with the experimental data for several miscible polymer blends.

Rich Phase Separation Behavior of Biomolecules

  • Shin, Yongdae
    • Molecules and Cells
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    • 제45권1호
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    • pp.6-15
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    • 2022
  • Phase separation is a thermodynamic process leading to the formation of compositionally distinct phases. For the past few years, numerous works have shown that biomolecular phase separation serves as biogenesis mechanisms of diverse intracellular condensates, and aberrant phase transitions are associated with disease states such as neurodegenerative diseases and cancers. Condensates exhibit rich phase behaviors including multiphase internal structuring, noise buffering, and compositional tunability. Recent studies have begun to uncover how a network of intermolecular interactions can give rise to various biophysical features of condensates. Here, we review phase behaviors of biomolecules, particularly with regard to regular solution models of binary and ternary mixtures. We discuss how these theoretical frameworks explain many aspects of the assembly, composition, and miscibility of diverse biomolecular phases, and highlight how a model-based approach can help elucidate the detailed thermodynamic principle for multicomponent intracellular phase separation.

비만치료를 목적으로 마테(Yerba Mate, Ilex paraguariensis)를 함유한 복합투여물의 효과 및 부작용에 대한 고찰 (A Review of Combination Effects and Adverse Effects of Yerba Mate (Ilex paraguariensis) on the Treatment of Obesity)

  • 안재현;이민호;이승훈;최도영;이재동
    • Journal of Acupuncture Research
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    • 제33권2호
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    • pp.135-150
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    • 2016
  • Objectives : The aim of this study is to review the combination effects and adverse effects of Yerba Mate (Ilex paraguariensis) on the treatment of obesity. Methods : Four databases were searched, including Pubmed, National assembly library, RISS4u, and NDSL, for studies published before March 31, 2016 using the keywords 'yerba mate', 'Ilex paraguariensis', and those related to 'obesity'. Clinical trials, and both in vivo and in vitro studies were classified according to the following categories: publication year, nationality, types and composition of test compounds, combination effects, adverse effects, and safety. Results : A total of 16 articles (14 clinical trials, one in vivo, one in vitro) were included in the analysis. Combination effects were reported from six YGD (Yerba Mate, Guarana, Damiana, Zotrim), five Meltdown, one Shred-matrix, one DBX (DymaBurn Xtreme), one XSIII research study, and adverse effects were reported from two YGD (Zotrim), four Meltdown, one Shred-matrix and one MetEF research study. YGD and Shred-matrix increased satiety while YGD and MetEF had adverse gastrointestinal effects potentially due to guarana. Meltdown and Shred-matrix increased energy expenditure and fat oxidation and had the adverse effects of increased heart rate and blood pressure due to the thermogenic effect of caffeine and yohimbine. DBX increased resting energy expenditure but no difference was observed in respiratory exchange ratio. XSIII reduced body weight gain and food intake more than each of the extracts did on their own. Conclusion : Taken together, the combination effects and adverse effects differed according to the composition of test compounds and the ratio of ingredients. Multicomponent approaches should be used for treating multifactorial diseases such as obesity. As a general conclusion, there is a place for a combination of herbal components including yerba mate, based on the principle of Kun-Shin-Choa-Sa for the treatment of obesity.

흡수식냉난방기용 다성분 리튬염 작동매체의 증기압 및 용해도 측정 (Measurement and Analysis on the Physical Properties of Multi Lithium Salts Solution in Absorption Heat-Pumps)

  • 주우성;김희택;오영삼;백영순
    • 공업화학
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    • 제9권1호
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    • pp.82-88
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    • 1998
  • 고효율 공냉형 흡수식 냉방기를 위한 신작동매체로 기존의 $LiBr-H_2O$계에 높은 흡수성과 용해성를 지닌 $LiNO_3$과 LiCl 무기물을 각각 첨가하여 제조하였다. 본 연구를 통하여 제조된 다성분계의 작동매체에 대한 용해도와 증기압을 측정하여 $LiBr-H_2O$계와 비교 분석하였으며, 이들에 대한 최적혼합비를 각각 구하였다. 용해도 측면에서 $LiBr-LiNO_3-H_2O$계의 경우, LiBr과 $LiNO_3$의 최적혼합 몰비는 5:1이었으며, 반면 $LiBr-LiNO_3-LiCl-H_2O$계의 경우 LiBr, $LiNO_3$, LiCl의 최적혼합몰비는 5:1:2로 나타났다. 한편 증기압은 $LiBr-H_2O$계에 $LiNO_3$의 첨가량이 증가하였으나, LiCl의 경우에는 첨가량이 증가함에 따라 감소하는 경향을 각각 나타내었다.

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건포도와 건바나나의 감마선 조사와 저장기간에 따른 열발광 및 전자스핀공명 특성과 관능적 품질 (Characteristics of Thermoluminescence and Electron Spin Resonance and Organoleptic Quality of Irradiated Raisin and Dried Banana During Storage)

  • 조덕조;권중호
    • 한국식품영양과학회지
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    • 제31권4호
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    • pp.609-614
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    • 2002
  • 방사선 조사(1~4 kGy)와 저장 기간(4$^{\circ}C$, 6개월)에 따른 건조과일의 TL 및 ESR검지 특성과 관능적 품질을 평가하였다. 건포도에서 분리된 mineral의 TL측정에서 비조사구는 200~30$0^{\circ}C$ 부근에서 매우 낮은 intensity의 glow curve(TLI)를 나타내었으나, 1 kGy 이상의 조사구에서는 특유의 peak가 18$0^{\circ}C$ 부근에서 나타나면서 선량 의존적으로 intensity가 증가되었다($R^2$=0.9684). 이로써 방사선 조사구와 비조사구의 판별이 6개월 동안 가능하였다. 또한 재조사(1 kG)에 의해 측정된 TL$_2$signal을 활용하여 TL ratio(TL$_1$/TL$_2$)를 계산하였을 때 검지결과의 신뢰도를 높일 수 있었다. 건 바나나의 ESR 측정에서 1 kGy 이상의 조사 시료는 crystalline sugar radical 유래의 전형적인 multicomponent line을 보여 주어 조사 여부의 판별이 가능하였고 signal의 강도는 선량 의존적($R^2$= 0.8977)으로 6개월 동안 비교적 안정하였다. 방사선 조사된 건조과일은 6개월까지 상품성이 잘 유지되었으므로 TL 및 ESR 분석은 건포도와 건 바나나의 검지 관리에 적합한 방법임이 확인되었다.