응집계 분자 환경에서 전기장 효과 연구

학위논문 (박사)-- 서울대학교 대학원 자연과학대학 화학부, 2017. 8. 강헌.In this dissertation, I studied the effect of electric field on a condensed-phase molecular system. Many experiments have been performed for the investigation of field-induced phenomena, but only a few experiments are available for well-defined experimental conditions with strong electric field. We invented the ice film capacitor method, which can apply strong electricfield across a frozen molecular film. The effect of the electric field was examined using this method. Chapter I introduces various experimental methods that are currently used to study field-induced phenomena. The advantages of the ice film capacitor method over other existing technique are briefly mentioned. In chapter II, the experimental methods used for the study in this thesis are explained. The detailed procedure of the ice film capacitor method and the basic principle of reflection absorption IR spectroscopy are introduced. Instrumentation of the methods is also described. In chapter III, the conformational change of 1, 2-dichloroethane (DCE) is investigated under the external electric field. Reflection absorption infrared spectroscopy was used for monitoring the molecular changes such as gauche/trans conversion and the reorientation of gauche-DCE. Trans-DCE molecules converted to gauche-DCE under an external electric field, and this conversion led to the reorientation of gauche-DCE along the electric field. The field-induced changes were occurred at 50 - 90 K, but not at 8 K, indicating that both thermal and electrostatic energies are needed to induce the conformational changes in a frozen molecular film. In chapter IV, the field-induced dissociation of acetic acid (AA) is studied using the ice film capacitor method. The dissociation of acid was monitored by using infrared spectroscopy and the mechanism of field-induced acid dissociation was discussed. AA molecules were dissociated into acetate ions by the external electric field at an acid-base interface. The amount of field-induced dissociation depended on the direction of the applied electric field, which suggests that the reaction was aided by the reorientation of reagent molecules. The effect of molecular size was studied by comparing the results of formic acid and propionic acid with those obtained for AA. The dissociation of smaller acids was more enhanced, supporting our interpretation that field-induced dissociation occurred via molecular reorientation.Chapter I. Introduction 1 I-1. Experimental Methods for Studying the Electric Field Effect 2 I-2. Advantages of Ice Film Capacitor Method 3 Reference 5 Chapter Ⅱ. Method 6 Ⅱ-1. Ice Film Capacitor Method 6 Ⅱ-2. Reflection Absorption FT-IR Spectroscopy 11 Ⅱ-3. Instruments 16 Reference 19 Chapter III. Electric Field-Induced Conformational Changes of 1,2-Dichloroethane in Frozen Films 29 Abstract 29 III-1. Introduction 31 III-2. Experimental Methods 32 III-3. Results and Discussion 34 III-4. Summary 42 Reference 44 Chapter IV. Field-Induced Acid Dissociation at the Acid-Base Interface 51 Abstract 51 IV-1. Introduction 53 IV-2. Experimental Methods 54 IV-3. Results 57 IV-4. Discussion 61 IV-5. Conclusion 65 Reference 66 Supporting Information 76 List of Publications 83 Abstract in Korean (Korean) 85Docto

A Study on the Point of View in Modern Picture Images and Main Agents of Visual Recognition : Focusing on the Rhetoric of View Point and Reading Logic of Picture

영화의 視點은 美學的 修辭學인 동시에, 관객의 力動的 태도와 결부되어 獨創的인 讀解 論理를 창출한다. 영화의 視點에 대한 이해는 영화 매체의 독자성과 특수성에 대한 이해의 시작이며, 視覺 매체이자 복합 매체로서의 영화의 無限한 表現可能性에 대한 탐구이다. 현재 우리 주변에서 과도할 정도로 범람하는 영상 이미지들을 수용하는 視覺的 主體와 리얼리티를 논의했다. 다양한 視點들이 결합, 상충하면서 統合的으로 관객에게 형성시키는 태도와, 그것이 텍스트의 어떤 의도와 목적을 달성하는가를 밝히고자 하였다. 영화에 대한 旣存의 視點 논의를 정리하여 시사점을 찾은 후, 영화 「파라노말 액티비티」와 CCTV의 메커니즘에서 드러나는 無視點과 非美學性의 요소들을 분석하였다. 무엇이 진짜로 보는 것이고 무엇이 거짓으로 보는 것인지, 그 한계는 어디에 있으며, ‘진짜’ 현실이 더 우리를 기만하는 경우는 없는지, 영화의 진정한 성질은 무엇인가 하는 점에 대한 깊이 있는 통찰이 필요하다

뉴럴 네트워크 구조를 이용한 햅틱 질감 표현 시스템

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Haptic Texture Modeling Using Photometric Stereo

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바이오센싱 어플리케이션을 위한 SiNW FET 의 AC 특성에 대한 조사

MasterSi NW-based BioFETs were successfully fabricated using top-down processes and their AC characteristics were investigated for pH sensing and biochemical applications. The output voltage gain in the range of 100 Hz to 300 kHz was extracted with various PBS concentration and pH values at room temperature. The gain increased proportional to PBS concentration above 100 kHz. Below 10 kHz, little variation with different PBS concentration was observed. Besides, the gain showed the enhancement of pH sensitivity above 100 kHz, similar to those of PBS concentration. These results indirectly indicate that AC operation can be useful to effectively extend Debye length and thus improve the sensitivity in point-of-care-testing (POCT) application

이미지를 이용한 맨손 환경에서의 햅틱 질감 렌더링 시스템

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Hybrid Haptic Texture Rendering Using Kinesthetic and Vibrotactile Feedback

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Photometric Stereo를 이용한 햅틱 질감 표현

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