• Title/Summary/Keyword: SANS

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Development of the 40m SANS Instrument at HANARO for Nanostructure Characterization (나노구조 분석을 위한 하나로 40m 소각중성자산란장치 개발)

  • Choi Sung-Min;Kim Tae-Hwan;Lee Ji-Hwan;Han Young-Soo;Lee Chang-Hee
    • Journal of the Korean Vacuum Society
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    • v.14 no.3
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    • pp.126-131
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    • 2005
  • Small-angle neutron scattering (SANS) is a very powerful techniques for nanostructure characterization. In this paper, we report the conceptual design and technical description of the 40 in small angle neutron scattering (SANS) insoument which is being developed by KAIST and KAERI for installation at 30 MW HANARO research reactor. For the optimal design of 40 m SANS, a series of computer simulation were pe.to.mod. The Q-.ange of the 40m SANS inst.ument is $0.0005\;\AA^{-1}-1.0\AA^{-1}$ which is a world top-class SANS Q-range. When the cold neutron spectrum used in the simulation is realized, the neutron flux at sample position is expected to be comparable to the current state-of-art SANS instrument in the world.

Control of Block Copolymer Microdomain: In-Situ and Real-Time SANS Studies of Polymerization-Induced Self-assembly of Block Copolymer Microdomain Structure

  • Koizumi, Satoshi;Yamauchi, Kazuhiro;Hasegawa, Hirokazu;Tanaka, Hirokazu;Motokawa, Ryuhei;Hashimoto, Takeji
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.71-72
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    • 2006
  • We investigated a simultaneous living anionic polymerization process of isoprene (I) and 4styrene-d_8$ (S) in $benzene-d_6$ as a solvent with sec-buthyllithium as an initiator into polyisoprene(PI)-block-poly($styrene-d_8$)(PS) and the polymerization-induced molecular self-assembling process. This process was observed in-situ by time-resolved small-angle neutron scattering (SANS) experiment. The SANS profiles measured exhibited three time regions, where (i) the selective growth of PI chains occurs; (ii) the living chain ends switch from isoprenyllithium to styryllithium, and (iii) the SANS exhibited the polymerization induced disorder-to-order transition and order-to-order transition.

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Small-Angle Neutron Scattering Study of the Structure of Micelles Formed by a Polystyrene-Poly(ethylene oxide) Diblock Copolymer in Aqueous Solution (수용액 내 폴리스티렌-폴리에틸옥사이드 이중블록공중합체 미셀 구조에 대한 소각중성자산란 연구)

  • Kang, Byoung-Yook;Choi, Mi-Ju;Hwang, Kyu-Hee;Lee, Kwang-Hee;Jin, Byoung-Suk
    • Polymer(Korea)
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    • v.33 no.5
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    • pp.485-489
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    • 2009
  • The temperature dependence of the structure of micelles formed by a deuterated polystyrene-poly(ethylene oxide) diblock copolymer (dPS-PEO) in heavy water were investigated with small-angle neutron scattering (SANS). SANS data were analyzed using the hard-sphere structure factor in combination with the form factor of a core-shell model. The micelle aggregation number and corona radius were obtained from the fits to the SANS data. The micelle aggregation numbers varied with temperature from 229 at $25^{\circ}C$ to 240 at $45^{\circ}C$, with a corresponding increase in the core radius. However, the shell thickness of micelles decreased with increasing temperature from 6.2 to 5.8 nm. These structural changes of micelles might be ascribed to the decrease in the hydration volume per hydrophilic group in the corona because of the increase in hydrophobicity of the PEO block with increasing temperature.

A Study of Dress Characteristics with Respect to Anti-Social Resisting Consciousness - Focus on the Relationship between 18th Century Sans-Culotte and a Hippy Style During the 1960s and 1970s as a Comparative Perspective - (반사회적 의식이 반영된 시대복식의 특성에 관한 연구 - 18세기 상-뀔로뜨와 1960, 70년대 히피 스타일의 비교를 중심으로 -)

  • Jun, Yuh-Sun;Kim, Young-Sam
    • Journal of the Korean Society of Costume
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    • v.62 no.6
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    • pp.112-126
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    • 2012
  • The style of a dress allows important characterization of an era since they reflect contemporary politics, society, culture and arts. Within a same category, period costumes develop into styles that reflect specific consciousness. The research method and the scope of the study are as follows: the research adopts a historical study method and a comparative research from a microscopic point. The scope includes resistance costumes that proceed with sans-culotte that comprises of the resistance party during the 18th French Revolution (1783-1799), and also a Hippy style which was popularized during the 1960s and 1970s for its anti-war movement. We researched both similarities and differences of design factors reflecting resisting consciousness in costumes that affected costume characteristics related to their socio-cultural background. Sans-culotte and the Hippie style reflect a common denominator in anti-social resisting customs. First, they show common characteristics that combine fashion trends of resistant element and design features. Second, they have common features which are the characteristics of deviation. On the other hand, these two customs also present a discriminative denominator in anti-social resisting customs. In the case of sans-culotte, they tend to symbolize confrontation by dividing into two equal parts: the old and new mode. Sans-culotte confronts the conventional mode and promotes practical costume styles based on justice standpoints. First, hippies pursue an exposition of individual emotions that disclose internal meanings of love and desire. Second, they focus on subjective characteristics and chase after masteries and pleasures by expressing intensity. Third, it extends and develops folk costumes from many countries that reveal ethnic trends. Therefore, this research compares and contrasts different changes in the fashions of revolutionary periods, and aims to recognize the relationship between design and costume characteristics, thus contributing to the predictions of future changes in fashion.

Thyroid Dysfunctions Associated with the Mood Symptoms and the Psychosomatic Symptoms in Patients with Schizophrenia (정신분열병 환자에서 갑상선기능과 기분증상 및 신체증상)

  • Kim, Se-Hee;Han, Doug-Hyun;Na, Churl;Min, Kyung-Joon;Joo, So-Youn
    • Korean Journal of Psychosomatic Medicine
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    • v.17 no.1
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    • pp.30-36
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    • 2009
  • Objectives : Thyroid function is associated with psychiatric disturbance such as mood symptoms, cognitive functions, anxiety and sleep problem. We evaluate the effects of thyroid dysfunction on negative symptoms of schizophrenia, mood symptoms and somatic symptoms in patients with schizophrenia. Methods : Sixty five patients with schizophrenia were recruited. The patients were classified into two groups; the patients with the history of abnormal thyroid indices level(group of abnormal thyroid function) and the patients without the history of normal thyroid indices level(group of normal thyroid function). At baseline and 8 weeks later, psychiatric symptoms were assessed with the Scale for the Assessment of Negative Symptoms (SANS), the Scale for the Assessment of Positive Symptoms(SAPS), and Beck Depression Inventory(BDI), Somatosensory Amplication Scale(SSAS). Results : During 8 weeks, there were significant differences in the changes of SANS, BDI, SSAS between group of abnormal thyroid function and group of normal thyroid function. Compared to group of normal thyroid function, group of abnormal thyroid function showed greater reduction of the scores of SANS(23.3%), BDI (19.6%), and SSAS(16.2%), respectively. However, there was no significant correlation between the scores of SANS, BDI, and SSAS. Conclusion : Our study suggested that abnormal thyroid indices would predict the prognosis of negative symptoms, mood symptoms, and somatic symtpoms in patients with schizophrenia.

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Body Modification in Fashion Illustrations Based on the Theory of 'Corps sans Organes' of Deleuze (들뢰즈의 기관 없는 신체론에 기반한 현대 패션일러스트레이션의 신체특성)

  • Lee, Jee-Hyun
    • Journal of the Korean Society of Costume
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    • v.61 no.9
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    • pp.27-38
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    • 2011
  • This study focused on the body modification in fashion illustration based on 'Corps sans Organes' of Deleuze. An argument about the changes of ideal body to define the aesthetic consciousness of times has lasted for a long time. Therefore, analyzing body modification in fashion illustration to express the ideal beauty could be effective motives to understand the changes of ideal bodies related with socio-cultural meanings, and be helpful to understand the overall trends of modern fashion illustration. To classify the types of body modification, the concept of 'Corps sans Organes' of Deleuze was used as an analyzing tool. As the final result, the characteristics of body modification could be divided into three groups; the fragmentation of bodies, the pastiche of bodies, and the abstraction of bodies. First, in the fragmentation of bodies, which is related with flexibility, pluralism, and subjective views on body, the bodies were separated as molecules. Second, the elements of pastiche of bodies could be subdivided into five sub-groups; sex, plants, animals, texts and figure, and machines. The pastiche of bodies was used to extend the limitation of human capabilities and to reinterpret the human identities. Last, the abstraction of bodies based on contingency, indeterminacy, and subjective associations could be related with the nomadic and indefinite body images. The body modification could be considered as the context of nomadism, indeterminacy, and virtuality of modern-times, and it would be the basic data to understand the body modification in fashion illustrations.

Quantitative Analysis of ″Polymer-Balls″ in Aqueous Solutions by Small-Angle Neutron Scattering

  • Shibayama, Mitsuhiro;Okabe, Satoshi;Nagao, Michihiro;Sugihara, Shinji;Aoshima, Sadahito;Harada, Tamotsu;Matsuoka, Hideki
    • Macromolecular Research
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    • v.10 no.6
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    • pp.311-317
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    • 2002
  • The quantitative analysis of polymer micelles consisting of amphiphilic block copolymers was carried out by small-angle neutron scattering (SANS). The block copolymers, made of poly(2-ethoxyethyl vinyl ether-b-2-hydroxyethyl vinyl ether)(poly(EOVE-b-HOVE)), exhibited a sharp morphological transition from a homogeneous solution to a micelle structure with increasing temperature. This transition is accompanied by a formation of spherical domains of poly(EOVE) with a radius around 200 $\AA$. The variations of the size and its distribution of the domains were investigated as a function of polymer concentration and temperature. The validity of SANS analysis, including the wavelength- and incident-beam-smearing effects of the SANS instrument, was examined with a pre-calibrated polystyrene latex.

Sizes and Structures of Micelles of Cationic Octadecyl Trimethyl Ammonium Chloride and Anionic Ammonium Dodecyl Sulfate Surfactants in Aqueous Solutions

  • Kim, Hong-Un;Lim, Kyung-Hee
    • Bulletin of the Korean Chemical Society
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    • v.25 no.3
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    • pp.382-388
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    • 2004
  • The sizes and structures of micelles formed in aqueous solutions of cationic octadecyl trimethyl ammonium chloride (OTAC) and anionic ammonium dodecyl sulfate (ADS) surfactants were investigated using smallangle neutron scattering (SANS), self-diffusion coefficients by pulsed-gradient spin-echo (PGSE) NMR, and dynamic light scattering (DLS) methods. SANS and DLS data indicate that their structures are spherical at concentrations as high as 300 mM. As the total surfactant concentration increases, the peaks of SANS spectra shift to higher scattering vector and become sharper, indicating that the intermicellar distance decreases and its distribution becomes narrower. This is due to more compact packing of surfactant molecules at high concentrations. The intermicellar distance of around 100 ${\AA}$ above 200 mM corresponds approximately to the diameter of one micelle. The sizes of spherical micelles are 61 ${\AA}$ and 41 ${\AA}$ for 9 mM OTAC and 10 mM ADS, respectively. Also the self-diffusion coefficients by PGSE-NMR yield the apparent sizes 96 ${\AA}$ and 31 ${\AA}$ for micelles of 1 mM OTAC and 10 mM ADS, respectively. For ADS solutions of high concentrations (100-300 mM), DLS data show that the micelle size remains constant at $25{\pm}2{\AA}$. This indicates that the transition in micellar shape does not take place up to 300 mM, which is consistent with the SANS results.

Optical Font Recognition For Printed Korean Characters Using Serif Pattern of Strokes

  • Kim, Soo-Hyung;Kim, Sam-Soo;Kwag, Hee-Kue;Lee, Guee-Sang
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.916-919
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    • 2002
  • This paper introduces the problem of typeface classification of Hangul characters and proposes features for typeface classification among Serif and Sans-serif classes. Serif classes have a small decorative stroke around the beginning of vertical strokes, while Sans-serif classes have no serif. Therefore, the serif part is first segmented from the vertical strokes, and the direction of the serif is computed as the feature for Hangul typeface identification. To evaluate the performance of the proposed system, we used 3,000 characters extracted from Korean documents - 1,500 from Serif fonts, other 1,500 from Sans-serif fonts.

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SANS Study on Dynamics of Block Copolymer Micelles (소각 중성자 산란(SANS)을 이용한 블록 공중합체 마이셀의 동역학 연구)

  • Choi, Soohyung
    • Polymer Science and Technology
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    • v.24 no.6
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    • pp.585-589
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    • 2013
  • 고분자 시스템에서 동역학은 열역학적 평형상태에 도달하는 메카니즘을 밝히는 중요한 분야이다. 용융 고분자에 비해 상대적으로 블록 공중합체 마이셀에 대한 동역학 연구는 실험적 한계와 이론적 배경의 부재로 인해 충분한 연구가 이루어지지 못하였다. 하지만, 최근 TR-SANS를 이용하여 고분자 마이셀의 동역학 연구가 점차 증가하고 있는 추세이다. 마이셀 동역학과 관련하여 현재까지 이루어진 연구 결과도 충분히 중요한 통찰력을 제시해주고 있지만, 아직 개척되지 못한 부분이 많이 남아있는 것도 사실이다. TR-SANS의 개념은 고분자 마이셀 뿐만 아니라 다양한 고분자 시스템에 적용할 수 있고, 더 나아가 Neutron Reflectivity에 적용할 경우 박막 내에서 고분자의 동역학도 연구할 수 있을 것으로 기대된다. 또한, TR-SANS 개념은 고분자 동역학 연구 분야 외에도 의학/생명공학 등 넓은 분야에서 이용될 수 있을 것으로 기대된다.

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