608 research outputs found
Subcooled water quenching on a super-hydrophilic surface under atmospheric pressure
No full textThe goal of this work is (i) to evaluate the cooling rate on a super-hydrophilic surface as a function of the subcooled degree Delta T-sub of the liquid coolant, (ii) to analyze the contact heat transfer q ''(c) of the liquid-solid contact, and (iii) to investigate the mechanism of microbubble emission boiling (MEB). We fabricated a super-hydrophilic surface by anodic oxidation of a zirconium vertical rod, so called completely wettable surface (CWS), which had surface microstructures with super-hydrophilicity. The CWS results in a decrease of the cooling time t(cool) as compared with the Bare Zirconium surface (BZS) results under small Delta T-sub (t(cool) similar to 50% decrease for Delta T-sub = 0, 15, and 40 K, respectively). However, its surface effect is limited in the case of large Delta T-sub (t(cool) similar to within 5% for Delta T-sub = 60 and 75 K). The fast quench on the CWS under Delta T-sub, explained by the increase in minimum film-boiling temperature T-MFB and rewetting velocity U, is due to the liquid-solid contact. We evaluate the contact area A(c) and volumetric absorption rate of the liquid dV/dt by conducting liquid absorption experiments. The increase in A(c) and dV/dt contribute to an increase in q"(c), by forming the liquid film at the liquid-solid contact spot. The orders of the time scale between capillary-wicking and liquid-solid contact are comparable. Destabilization of the large vapor bubble is caused by an increase in q"(c), which is a major reason for MEB generation, and this mechanism enables the q" to be significantly high on the CWS under subcooled quenching. (C) 2017 Elsevier Ltd. All rights reserved.116sciescopu
Acoustic emission during magnetization in 3％ Si-Fe single crystal
No full text학위논문(석사) - 한국과학기술원 : 물리학과, 1986.2, [ [iii], 56 p. ]한국과학기술원 : 물리학과
Induced liquid-solid contact via micro/nano multiscale texture on a surface and its effect on the Leidenfrost temperature
No full textA significant increase in the Leidenfrost temperature (LFT) was observed on a micro/nano rnultiscale textured surface (MTS) compared with a polished surface (PS) and a micro rough surface (MRS). MTS was fabricated by anodic oxidation and has nano-scaled needles with micro roughness. It showed improved surface wetting characteristics (0 contact angle with liquid spreading). On the other hand, MRS was fabricated by mechanical polishing and it only has micro roughness. LFT on MTS and MRS increased by approximately 150 degrees C and 30 degrees C, respectively, compared with one for PS. The textures on each surface influenced the water droplet dynamics. The relationship between LFT and the dynamics of water droplet were studied by high-speed photography. The key phenomenon determining LFT was the rebound process of the droplet during a few milliseconds. On MRS and MTS, the rebound phenomenon of the droplet was disturbed by the surface-texture-induced liquid-solid contact even when the surface was initially at a high temperature over 300 degrees C. The precursor wetting front, observed only on MTS and the capillary wicking phenomenon are likely the responsible mechanisms that significantly increased LFT on MTS. (C) 2017 Elsevier Inc. All rights reserved.1110sciescopu
Quenching of candidate materials for accident tolerant fuel-cladding in LWRs
No full textA quenching experiment with a vertical rod (diameter D = 10 mm and length L = 60 mm) was conducted under atmospheric pressure and saturation temperature of water to investigate the boiling parameters in the post-critical heat flux (CHF) regime for the candidate materials of accident tolerant fuel-cladding (ATF): FeCrAI(APMT) and SiC-CVD, compared to commercial cladding material Zircaloy-4(Zry-4) in light water reactors (LWRs). We prepared two test groups (plain surface PS and oxidized surface OS) and evaluated their surface parameters (roughness epsilon, contact angle theta(c), oxygen content of the surface, and oxide layer thickness delta(oxide)) and thermal properties (heat capacity rho C-p and thermal conductivity k) that influence the quenching performance. We analyzed the minimum film-boiling temperature T-MFB, minimum heat flux q"(min), and the heat transfer coefficient of film boiling h(film), under all test conditions. In particular, the surface damage of the SiC-CVD after quenching was analyzed by considering the post-CHF heat transfer condition, and its impact was evaluated at T-MFB during quenching. (C) 2017 Elsevier Ltd. All rights reserved.114sciescopu
Organic Transistor-Based Chemical Sensors for Wearable Bioelectronics
No full textCONSPECTUS: Bioelectronics for healthcare that monitor the health information on users in real time have stepped into the limelight as crucial electronic devices for the future due to the increased demand for "point-of-care" testing, which is defined as medical diagnostic testing at the time and place of patient care. In contrast to traditional diagnostic testing, which is generally conducted at medical institutions with diagnostic instruments and requires a long time for specimen analysis, point-of-care testing can be accomplished personally at the bedside, and health information on users can be monitored in real time. Advances in materials science and device technology have enabled next-generation electronics, including flexible, stretchable, and biocompatible electronic devices, bringing the commercialization of personalized healthcare devices increasingly within reach, e.g., wearable bioelectronics attached to the body that monitor the health information on users in real time. Additionally, the monitoring of harmful factors in the environment surrounding the user, such as air pollutants, chemicals, and ultraviolet light, is also important for health maintenance because such factors can have short- and long-term detrimental effects on the human body. The precise detection of chemical species from both the human body and the surrounding environment is crucial for personal health care because of the abundant information that such factors can provide when determining a person's health condition. In this respect, sensor applications based on an organic-transistor platform have various advantages, including signal amplification, molecular design capability, low cost, and mechanical robustness (e.g., flexibility and stretchability). This Account covers recent progress in organic transistor-based chemical sensors that detect various chemical species in the human body or the surrounding environment, which will be the core elements of wearable electronic devices. There has been considerable effort to develop high-performance chemical sensors based on organic-transistor platforms through material design and device engineering. Various experimental approaches have been adopted to develop chemical sensors with high sensitivity, selectivity, and stability, including the synthesis of new materials, structural engineering, surface functionalization, and device engineering. In this Account, we first provide a brief introduction to the operating principles of transistor-based chemical sensors. Then we summarize the progress in the fabrication of transistor-based chemical sensors that detect chemical species from the human body (e.g., molecules in sweat, saliva, urine, tears, etc.). We then highlight examples of chemical sensors for detecting harmful chemicals in the environment surrounding the user (e.g., nitrogen oxides, sulfur dioxide, volatile organic compounds, liquid-phase organic solvents, and heavy metal ions). Finally, we conclude this Account with a perspective on the wearable bioelectronics, especially focusing on organic electronic materials and devices.11sciescopu
Effect of Dual Coplanar Electrodes on Mercury-Free Flat Fluorescent Lamps for Liquid Crystal Display
No full textThe effects of dual coplanar electrodes on a Hg-free flat fluorescent lamp were studied. For a dual coplanar lamp, brightness and efficacy were improved by 80% compared to a conventional coplanar lamp. The improvement is regarded as the result of reduced diffusion loss and the effective usage of the discharge volume in the dual coplanar lamps. An efficacy of 35.9 lm/w (14900 cd/m(2)) was achieved for 250 torr of a Xe(30%)/Ne(70%) gas mixture, by a 20-kHz ac pulse driving
A Study on Lee Ho-Cheol's War Novels and Discourse on Memory
No full text이호철은 피난, 월남 등 작가의 체험과 관련하여 분단의식을 규명하는 연구가 많이 진행되었다. 하지만 대부분의 연구가 전쟁이후의 체험에 초점을 두고 있음을 확인할 수 있다. 그렇기에 본고는 이호철의 작가의식을 살펴보기 위해서는 전쟁참전의 경험에서부터 출발하여 그 기억으로 인한 변화양상 역시 중요하게 논의되어야 한다는 문제의식을 기반으로 한다. 따라서 이호철 소설 중 전쟁기억이 드러난 텍스트를 ‘기억이론’을 통해 살펴봄으로써, 각 시기별 기억의 양상과 그 결이 변화하는 과정을 통해 나름의 의의를 고찰하는데 그 목적이 있다.
기억이론, 특히 ‘상흔의 기억(Trauma)’은 이호철과 한국전쟁의 관계 속에 놓인 여러 문제들을 관통할 수 있는 개념이다. 프로이트, 라깡, 오카마리, 라카프라 등에 의하면 트라우마는 개인의 심리적 상처이지만 이를 애도하고, 타자에 대한 윤리적 책무를 깨닫는 순간 사회를 변화시킬 수 있는 힘으로 나아갈 수 있음을 밝힌바 있다. 이는 트라우마가 가진 역동적 메커니즘을 통해 텍스트와 작가, 사회가 얽히는 복잡한 관계를 아울러서 살펴볼 수 있음을 의미한다. 그렇기에 유일의 분단국가로서 아직까지 한국전쟁을 이용한 기억의 정치가 작동되는 한국사회와 그로 인해 파생된 기억의 문제 안에 자리한 이호철의 연관관계를 살펴볼 수 있는 방법인 것이다.
Ⅱ장에서는 한국전쟁 직후 진행된 강력한 기억정치로 인해, 인민군으로 참전했던 이호철의 전쟁경험이 트라우마화될 수밖에 없었음을 주목한다. 이러한 트라우마는 압제받는 체험이자 부인되어야 하는 기억이지만, 잊기에는 너무 경악스럽기에 강박적으로 반복되는 증상(acting out)으로써 회귀한다. 갑작스럽게 도래하는 상처의 기억은 주체로 하여금 분열될 수밖에 없도록 만들고, 언어까지도 분열시킨다. 이는 전쟁기억에 다가가기 거부하면서도, 결국 거리감을 상실하고 무차별적인 합일에 이르는 분열된 이중언어로 등장한다. 상흔의 기억에 가깝게 다가갈 때 혹은 기억이 갑작스럽게 침투하는 순간 뚜렷해지는 혼란은 전쟁에서 살아남은 생존자임에도 희생자와 같은 삶을 살고 있음을 보여준다.
하지만 억압받았던 기억을 이야기하는 것이 허용되는 사회적 분위기가 형성되는 순간, 상처를 위로하려는 애도(mourning)의 움직임이 시작된다. 이호철 역시 이를 시도하는데, Ⅲ장에서 자전적 소설인 『남녘사람 북녁사람』연작을 통해 전쟁기억을 재인식하려는 작가의 노력을 구체적으로 살펴본다. 연작 안에서 등장한 전쟁기억들은 그간 강건하게 형성되어 있던 공적기억의 틀을 흐림으로써 목소리를 낼 수 있는 자리를 확보할 수 있게 만들고, 이어 타인과의 관계를 통해 생존자로서의 새로운 정체성을 구축하게 된다. 이러한 작업은 불가해했던 상흔의 기억에 의미를 채우면서도, 그 안에 있는 공백을 그대로 드러내는 이중언어를 통해서 구체화된다. 그리고 이를 통해 트라우마는 비로써 애도되고, 그럼에도 남는 사건의 잉여로 인해 또 다른 움직임으로 나아갈 수 있게 된다.
트라우마가 필연적으로 지니게 되는 공백은 전쟁기억을 편안히 망각할 수 없도록 만든다. 그렇기에 Ⅳ장에서 작가는 한국전쟁의 기억을 개인적 경험의 수준을 넘어 사회적인 수준으로 전환하려 하는 적극적 태도를 견지하게 된다. 이제 다양한 자리에서 전쟁을 겪은 사람들의 고통이 현현되어 개개의 기억으로 분유(分有)되기 시작하고, 동시에 그 기억들은 적층되어 새로운 기억을 구축하는 반복의 과정을 시행한다. 이러한 과정은 타자들로 하여금 상처의 기억을 쉽게 말할 수 있도록 안정의 언어를 구사하면서도, 동시에 대화에 내재되어 있는 불안을 남겨둠으로써 대화가 계속될 수 있게 하는 전략의 이중언어를 통해 지속된다. 그리고 이는 사실과 허구를 뒤섞는 실험적 형식과 구술의 언어를 통해서 강화된다. 이러한 서사적 긴장감은 생산적인 대화를 이끌어냄으로써, 성찰적 극복(working through)의 과정을 끊임없이 실천하는 윤리적인 태도로까지 나아가게 된다.
이호철 소설에서 한국전쟁에 관한 기억의 양상과 그 의미를 살펴보는 일을 통해 작가가 자신의 체험을 단순히 형상화해내는 것에 그치지 않고, 사회‧정치적인 과정에 관여할 수 있도록 의식적인 확장을 시도했다는 것을 확인했다. 이는 이호철 소설에 대한 그간의 평가와는 다른 의미의 윤리성을 새롭게 확보한 것이며, 나아가 한국전쟁을 다룬 다른 작가들과도 차별되는, 자신만의 문학적 깊이와 무게감을 보여준 작가라는 의미를 획득하게 된다.
이호철은 현재까지도 창작활동을 멈추지 않고 있는 건재한 작가이다. 그렇기에 지금도 계속되고 있는 그의 노력이 어떻게 변모할지는 예상할 수 없다. 하지만 그럼에도 확신할 수 있는 것은 그의 이러한 기억작업이, 더불어 넓게는 그가 보이고 있는 분단의식이 정치‧권력의 압제를 떠나 온전히 평가받을 수 있는 날이 오기까지 계속될 것이란 점이다. 그렇기에 긴장의 끈을 놓지 말고, 이후에도 이어질 이호철의 문학작업을 계속해서 주목해야 할 것이다.;As for Lee Ho-Cheol, many studies have been done for examining division consciousness related to his experience including seeking refuge and coming from North Korea. However, it shows that most studies are focused on postwar experiences. Therefore, this study is based on the critical issue as follows. To examine writer's consciousness of Lee Ho-Cheol, beginning from his experience of entry into the war, transition by such memory has to be discussed with emphasis. So, among Lee Ho-Cheol's novels, while inspecting texts memory of war reveals through the 'Memory Theory', this study intends to examine aspects of memory by period with their significance through a transition process.
A memory theory, particularly trauma is the concept penetrating many issues in regard to Lee Ho-Cheol and the Korean War. According to Freud, Lacan, Okamari and LaCapra, though trauma is an individual psychological wound, as soon as he mourns for it and recognize his ethical obligation to others, it may be the driving force for changing a society. It means that it's possible to examine complex relationship text, writer and society are entangled through a dynamic mechanism of trauma. Accordingly, it's the method for reviewing Lee Ho-Cheol's connection in the Korean society there's still politics of memory using the war as the only divided nation and resulting problems of memory.
In Chapter Ⅱ, this study pays attention to the war experience of Lee Ho-Cheol, who joined the war as a North Korean Peoples Army owing to the strong politics of memory after the Korean War, becoming the trauma. Such a trauma is experience to be oppressed and memory to be denied but it's too shocking to forget so returns to obsessively repetitive acting out. Memory of wound coming suddenly makes a subject disrupted, even to the language. It appears as the disrupted bilingual, rejecting to approach the war memory but losing a sense of distance and reaching indiscriminate unity in the end. Confusion manifesting itself when approaching the memory of a scar, or when memory penetrates suddenly, shows that he's living a life like a victim despite a survivor from the war.
However, the moment there's a social atmosphere to permit telling the oppressed memory, movement of mourning begins to soothe the wound. Lee Ho-Cheol also attempts it. In Chapter Ⅲ, this study examines his effort to re-perceive the war memory through his autobiographical novel series, 『The Southerners, Northerners』. War memory in the series ensures a place for voicing by obscuring a frame of the public memory that has been stabilized, constructing a new identity as a survivor through relations with others. Such a work comes to be embodied by the bilingual adding the meaning to the incomprehensible memory of a scar but showing its vacuum. Through such a work, trauma is mourned at last, but due to the remainder of events, further movement may be advanced forward.
Vacuum trauma has inevitably makes one unforget the war memory easily. So, in Chapter Ⅳ, the writer comes to take an active attitude to convert memory of the Korean War to the social level beyond the private level of experience. Now, in the various places, suffering of people who went through the war manifests itself, beginning to be shared as individual memory. At the same time, such a memory gets accumulated and conducts a repetitive process to construct a new memory. Such a process continues through the bilingual with a strategy to speak the language of stability while making others tell memory of wound easily and continue conversation while leaving anxiety inherent in the conversation. In addition, it's intensified by the experimental mode mixing a fact and fiction with the oral language. Such a narrative tension derives a productive conversation, leading to the ethical attitude practicing a process of working through continually.
As for novels of Lee Ho-Cheol, examining aspects of memory of the Korean War and their significance, it shows that he attempted to expand consciousness to be involved in social ‧politic processes rather than simply illustrate his experience. It means that ethicality was ensured newly different from prior evaluations on novels of Lee Ho-Cheol. Furthermore, it has the significance that he's a writer who has shown his own literary depth and weight differentiated from others who have dealt with the Korean War.
Lee Ho-Cheol is the author who never stops creative activities even now. So, it's not possible to predict what change his ever-continuing efforts will undergo. However, it's certain that his memory working, broadly speaking, his division consciousness, until the day it can be evaluated as it is escaping from oppression by political power, will continue constantly. Therefore, heightening the tension, it's required to take notice of his literary working to be continued.Ⅰ. 서론 1
A. 연구사 검토 및 문제제기 1
B. 연구 방법 및 연구 대상 10
Ⅱ. 전쟁기억의 트라우마화와 강박적 반복 32
A. 무차별적 침투와 희생자 주체 34
B. 거부와 합일의 이중언어와 미결정적 서사 48
Ⅲ. 전쟁기억의 재인식과 의식적 애도 67
A. 사건의 의미화와 생존자 주체 69
B. 채움과 공백의 이중언어와 통찰적 서사 85
Ⅳ. 전쟁기억의 확장과 성찰적 극복 107
A. 증언의 분유와 수행자 주체 110
B. 안정과 불안의 이중언어와 윤리적 서사 124
Ⅴ. 결론 148
참고문헌 152
ABSTRACT 16
Disruption of Firmicutes and Actinobacteria abundance in tomato rhizosphere causes the incidence of bacterial wilt disease
No full textEnrichment of protective microbiota in the rhizosphere facilitates disease suppression. However, how the disruption of protective rhizobacteria affects disease suppression is largely unknown. Here, we analyzed the rhizosphere microbial community of a healthy and diseased tomato plant grown <30-cm apart in a greenhouse at three different locations in South Korea. The abundance of Gram-positive Actinobacteria and Firmicutes phyla was lower in diseased rhizosphere soil (DRS) than in healthy rhizosphere soil (HRS) without changes in the causative Ralstonia solanacearum population. Artificial disruption of Gram-positive bacteria in HRS using 500-μg/mL vancomycin increased bacterial wilt occurrence in tomato. To identify HRS-specific and plant-protective Gram-positive bacteria species, Brevibacterium frigoritolerans HRS1, Bacillus niacini HRS2, Solibacillus silvestris HRS3, and Bacillus luciferensis HRS4 were selected from among 326 heat-stable culturable bacteria isolates. These four strains did not directly antagonize R. solanacearum but activated plant immunity. A synthetic community comprising these four strains displayed greater immune activation against R. solanacearum and extended plant protection by 4 more days in comparison with each individual strain. Overall, our results demonstrate for the first time that dysbiosis of the protective Gram-positive bacterial community in DRS promotes the incidence of disease.
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