• 제목/요약/키워드: glancing

검색결과 68건 처리시간 0.023초

Superhard SiC Thin Films with a Microstructure of Nanocolumnar Crystalline Grains and an Amorphous Intergranular Phase

  • Lim, Kwan-Won;Sim, Yong-Sub;Huh, Joo-Youl;Park, Jong-Keuk;Lee, Wook-Seong;Baik, Young-Joon
    • Corrosion Science and Technology
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    • 제18권5호
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    • pp.206-211
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    • 2019
  • Silicon carbide (SiC) thin films become superhard when they have microstructures of nanocolumnar crystalline grains (NCCG) with an intergranular amorphous SiC matrix. We investigated the role of ion bombardment and deposition temperature in forming the NCCG in SiC thin films. A direct-current (DC) unbalanced magnetron sputtering method was used with pure Ar as sputtering gas to deposit the SiC thin films at fixed target power of 200 W and chamber pressure of 0.4 Pa. The Ar ion bombardment of the deposited films was conducted by applying a negative DC bias voltage 0-100 V to the substrate during deposition. The deposition temperature was varied between room temperature and $450^{\circ}C$. Above a critical bias voltage of -80 V, the NCCG formed, whereas, below it, the SiC films were amorphous. Additionally, a minimum thermal energy (corresponding to a deposition temperature of $450^{\circ}C$ in this study) was required for the NCCG formation. Transmission electron microscopy, Raman spectroscopy, and glancing angle X-ray diffraction analysis (GAXRD) were conducted to probe the samples' structural characteristics. Of those methods, Raman spectroscopy was a particularly efficient non-destructive tool to analyze the formation of the SiC NCCG in the film, whereas GAXRD was insufficiently sensitive.

A Study on the Magnetic Properties of Ion Irradiated Cu/Co Multilayer System

  • Kim, T.Y.;Chang, G.S.;Son, J.H.;Kim, S.H.;Shin, S.W.;Chae, K.H.;Sung, M.C.;Lee, J.;Jeong, K.;Lee, Y.P.;;Whang, C.N
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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    • pp.163-163
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    • 2000
  • In this research, we used the ion irradiation technique which has an advantae in improving intentionally the properties of surface and interface in a non-equilibrium, instead of the conventional annealing method which has been known to improve the material properties in the equilibrium stat. Cu/Co multilayered films were prepared on SiN4/SiO2/Si substrates by the electron-beam evaporation for the Co layers and the thermal evaporation for the Cu layers in a high vacuum. The ion irradiation with a 80keV Ar+ was carried out at various ion doses in a high vacuum. Hysteresis loops of the films were investigated by magneto-optical polar Kerr spectroscopy at various experimental conditions. The change of atomic structure of the films before and after the ion irradiation was studied by glancing angle x-ray diffraction, and the intermixing between Co and Cu sublayers was confirmed by Rutherford backscattering spectroscopy. The surface roughness and magneto-resistance were measured by atomic force microscopy and with a four-point probe system, respectively. During the magneto-resistance measurement, we changed temperature and the direction of magnetization. From the results of experiments, we found that the change at the interfaces of the Cu/Co multilayered film induced by ion irradiation cause the change of magnetic properties. According to the change in hysteresis loop, the surface inplane component of magnetic easy axis was isotropic before the ion irradiation, but became anisotropic upon irradiation. It was confirmed that this change influences the axial behavior of magneto-resistance. Especially, the magneto-resistance varied in accordance with an external magnetic field and the direction of current, which means that magneto-resistance also shows the uniaxial behavior.

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GLAD법으로 증착한 Smart window용 WO3와 TiO2의 전기변색적 특성 비교

  • 김성한;송풍근
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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    • pp.198-198
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    • 2015
  • 전기변색재료는 전압을 인가하였을 때 전계방향에 따라 가역적으로 색이 변화하는 재료를 말한다. 스마트윈도우용 전기 변색재료는 지속적으로 전기를 가해줄 필요 없이 한번 변색되면 색이 지속되는 특징을 가지므로 에너지 효율적으로 우수하여 태양열 차단 창호나 디스플레이 분야에 응용될 것으로 기대된다. 이러한 전기 변색재료에는 산화형 전기 변색 재료, 환원형 전기 변색 재료가 있는데 이중 가장 널리 연구되고 있는 재료는 환원형 전기변색재료이다. 대표적인 재료로 $WO_3$가 쓰이는 데 이는 전기 변색적 특성이 우수하고 또한 내구성이 다른 재료에 비해 우수하다는 장점 때문이다. 그러나, 상용화를 위해서는 내구성의 개선이 요구되고 있다. 한편, $TiO_2$는 안정성이 매우 뛰어나지만 전기변색적 특성이 $WO_3$에 비해 낮은 점이 지적되고 있다. 이러한 $WO_3$$TiO_2$ 박막은 스퍼터링 또는 sol-gel법 등으로 제작되고 있는데, 일반적으로 스퍼터링의 경우 치밀한 박막이 형성되기 때문에 Porous 한 박막을 얻기 힘들다. 따라서 본 연구에서는 기판에 입사하는 스퍼터 입자들의 각도를 조절하여 shadowing 효과로 인해 박막의 구조가 porous해지는 Glancing angle deposition을 도입하였다. 이러한 증착법을 이용하여 $WO_3$$TiO_2$를 각도를 조절하여 증착하고 $TiO_2$$WO_3$ 박막의 특성을 비교하여 본다. 두께 300 nm를 가지는 $WO_3$$TiO_2$ 박막은 GLAD RF 마그네트론 스퍼터링법을 이용하여 Corning glass(corning E-2000)기판 위에 증착하였다. 기판 입사 각도는 $0^{\circ}$, $30^{\circ}$, $45^{\circ}$, $60^{\circ}$로 증착하였고 직경 3 in의 $TiO_2$, $WO_3$ 타겟을 사용하였다. 또한 스퍼터링 파워는 400 W, 작업압력 1.0 Pa, 그리고 스퍼터링 가스는 O2/Ar+O2 유량 10%에서 30%로 증착을 상온에서 진행하였다. 전기화학적 특성을 평가하기 위하여 $TiO_2$$WO_3$ 박막을 100 nm 두께의 ITO/glass 위에서 증착하였다. 박막의 미세구조는 XRD와 SEM을 통해 확인하였고, 전기화학적 특성은 Ar 분위기의 Glove box안에서 parstat 2273을 통해 측정하였다. 전해질은 1 M $LiPF_6/PC$로 진행하였고, 대향 전극는 Pt전극을, 참고 전극은 칼로멜 전극을 사용하였다. Potential 범위는 2 V에서 4 V로 진행하였고, scan rate는 50 mV/s로 측정하였다. 투과도는 UV/VIS spectrometer로 측정하였다. 전기변색 특성의 상관관계 및 에 대해서는 학회 당일 발표할 예정이다.

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CHARACTERISTICS OF HETEROEPITAXIALLY GROWN $Y_2$O$_3$ FILMS BY r-ICB FOR VLSI

  • Choi, S.C.;Cho, M.H.;Whangbo, S.W.;Kim, M.S.;Whang, C.N.;Kang, S.B.;Lee, S.I.;Lee, M.Y.
    • 한국표면공학회지
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    • 제29권6호
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    • pp.809-815
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    • 1996
  • $Y_2O_3$-based metal-insulator-semiconductor (MIS) structure on p-Si(100) has been studied. Films were prepared by UHV reactive ionized cluster beam deposition (r-ICBD) system. The base pressure of the system was about $1 \times 10^{-9}$ -9/ Torr and the process pressure $2 \times 10^{-5}$ Torr in oxygen ambience. Glancing X-ray diffraction(GXRD) and in-situ reflection high energy electron diffracton(RHEED) analyses were performed to investigate the crystallinity of the films. The results show phase change from amorphous state to crystalline one with increasingqr acceleration voltage and substrate temperature. It is also found that the phase transformation from $Y_2O_3$(111)//Si(100) to $Y_2O_3$(110)//Si(100) in growing directions takes place between $500^{\circ}C$ and $700^{\circ}C$. Especially as acceleration voltage is increased, preferentially oriented crystallinity was increased. Finally under the condition of above substrate temperature $700^{\circ}C$ and acceleration voltage 5kV, the $Y_2O_3$films are found to be grown epitaxially in direction of $Y_2O_3$(1l0)//Si(100) by observation of transmission electron microscope(TEM). Capacitance-voltage and current-voltage measurements were conducted to characterize Al/$Y_2O_3$/Si MIS structure with varying acceleration voltage and substrate temperature. Deposited $Y_2O_3$ films of thickness of nearly 300$\AA$ show that the breakdown field increases to 7~8MV /cm at the same conditon of epitaxial growing. These results also coincide with XPS spectra which indicate better stoichiometric characteristic in the condition of better crystalline one. After oxidation the breakdown field increases to 13MV /cm because the MIS structure contains interface silicon oxide of about 30$\AA$. In this case the dielectric constant of only $Y_2O_3$ layer is found to be $\in$15.6. These results have demonstrated the potential of using yttrium oxide for future VLSI/ULSI gate insulator applications.

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한국의 창안(創案)리더십 사례연구 - 사회편익(社會便益)의 공헌(貢獻)을 중심으로 - (A case study on Korea Creative Leadership - Focusing on the contribution of social benefiting)

  • 이경남
    • 한국철학논집
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    • 제23호
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    • pp.129-154
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    • 2008
  • 본 논문은 한국형 리더십 모형을 제시하는 시론의 하나로 기획된 연구로서, 창안리더십의 핵심가치와 사례에 대한 결과물이다. 이 연구를 통해보면, 창안리더의 특질은 특히 사회편익을 위한 실용과 생활혁신의 측면 즉 조직과 사회의 영역에서 빛을 발하고 있음을 알 수 있다. 창안리더십을 주도한 인물들은 대체로 개인영역에서 사회영역으로 양적, 질적 영역확대를 거친 사회적 리더로 밝혀졌다. 창안리더십의 발전과정을 보면, 개인영역(Self)의 핵심가치는 자기를 완성하는 정기(正己)로 자기 성찰을 통한 정체성을 확립하고 있으며, 이는 자기주도성, 관찰실험정신, 강한 탐구심 등의 역량으로 발휘되고 있다. 다음으로 관계영역(Relationship)의 핵심가치는 기혈상통(氣血相通)의 네트워킹(Networking) 활성화이며, 이는 타인존중과 배려, 유형분석, 설득의 역량으로 나타난다. 다음으로 조직영역(Team)의 핵심가치는 수시(授時)와 정음(正音)의 실용과 검증이며, 이는 조정과 조절, 팀워크(Teamwork) 조성과 개선으로 그 역량이 발휘되었다. 나아가 결국 사회영역(Community)에서는 훈민(訓民)과 활인(活人)의 사회기여라는 핵심가치로 결실을 맺는데, 그 구체적인 역량은 비전제시, 사회편익, 생활혁신 등으로 표출되어 실천된다. 본 논문의 의의를 살펴보면, 창안의 특질을 지닌 리더를 통해 한국형리더십의 원형을 구축해 보고, 사례분석을 통해 우리 고유의 리더십 속성이 무엇인지를 규명하고자한 점에서 의미가 있다고 본다.

고감도 H2S 감지를 위한 SnO2 장식된 Cr2O3 nanorods 이종구조 (Heterostructures of SnO2-Decorated Cr2O3 Nanorods for Highly Sensitive H2S Detection)

  • 정재한;조윤행;황준호;이수형;이승기;박시형;손성우;조동휘;이광재;심영석
    • 센서학회지
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    • 제33권1호
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    • pp.40-47
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    • 2024
  • The creation of vertically aligned one-dimensional (1D) nanostructures through the decoration of n-type tin oxide (SnO2) on p-type chromium oxide (Cr2O3) constitutes an effective strategy for enhancing gas sensing performance. These heterostructures are deposited in multiple stages using a glancing angle deposition technique with an electron beam evaporator, resulting in a reduction in the surface porosity of the nanorods as SnO2 is incorporated. In comparison to Cr2O3 films, the bare Cr2O3 nanorods exhibits a response 3.3 times greater to 50 ppm H2S at 300℃, while the SnO2-decorated Cr2O3 nanorods demonstrate an eleven-fold increase in response. Furthermore, when subjected to various gases (CH4, H2S, CO2, H2), a notable selectivity toward H2S is observed. This study paves the way for the development of p-type semiconductor sensors with heightened selectivity and sensitivity towards H2S, thus advancing the prospects of gas sensor technology.

계몽기·근대시조 DB의 개선 및 콘텐츠화 방안 연구 (A study on the improving and constructing the content for the Sijo database in the Period of Modern Enlightenment)

  • 장정수
    • 한국시조학회지:시조학논총
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    • 제44권
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    • pp.105-138
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    • 2016
  • 최근 검색 기능을 갖춘 "계몽기 근대시조의 XML 데이터베이스 문서화"라는 자료가 기초학문자료센터(http://www.krm.or.kr)를 통해 제공되고 있어 근대시조의 문화콘텐츠화를 진행할 수 있는 기반이 마련되었다. 이에 본고에서는 계몽기 근대시조 DB의 특성 및 문제점을 검토해 보고 개선 방향을 탐색함으로써 이 자료의 콘텐츠화 방안을 모색해 보았다. 계몽기 근대시조 DB는 12,500여 수에 이르는 방대한 양의 근대시조를 한자리에서 일별할 수 있도록 집성해 놓았다는 점과 문헌 및 작가명 작품명 검색, 원문 검색, 시기별 검색 등의 검색 기능을 갖춘 최초의 시조 DB라는 점에서 의의를 지닌다. 그러나 이 DB는 현대어 정규화 텍스트가 형성되지 않아 제목이나 원문이 고어나 한자로 표기되어 있는 경우 검색이 되지 않으며, 1945년 이후에 발표된 작품과 개인 시조집에 수록된 작품이 대거 누락되어 있어 계몽기 근대시조의 총체적 모습을 확인하는 데에 한계가 있다는 문제점을 지니고 있다. 또한 작자 표시가 실명, 호, 필명 등으로 다양하게 표기되어 있어 작가별 자료 추출에 불편함이 따르는 문제가 있다. 이러한 문제점을 해결하고 DB 활용을 제고(提高)하는 방안으로 본고에서는 현대어 정규화 텍스트 마련, 작품 별 내용소(內容素) 색인어 부여, 고시조 DB와의 통합, 작품 형식에 대한 정보 제공 등을 제시하였다. 나아가 '시조문화정보시스템'의 성격을 갖춘 복합적인 성격의 계몽기 근대시조 DB가 형성된다면 이를 연구 및 교육콘텐츠로 활용할 수 있음을 피력하였다. 그 구체적인 방안으로는 근대사 학습 및 근대기 국토 인식 등에 대한 보조 자료, 고유의 동식물 캐릭터 학습 및 상업적 캐릭터 생성을 위한 원천 자료, 시조놀이 등의 시조학습 도구로 활용할 수 있음을 제안하였다.

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가정학교육 영역에서의 인구교육문제에 관한 조사연구 -선임가정학자들을 대상으로- (A Study of the Attitude of/and Problems Encountered by Senjor Home Economist Toward the Integration of Family Planning Education in the Korean Formal School System)

  • 김지화
    • 대한가정학회지
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    • 제19권3호
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    • pp.83-101
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    • 1981
  • Under the full consideration of the growing need and importance of population education in the field of home economics in Korea, the study was carried out to verify and assess the following facts on the current issues of population education of home economists who are presently engaging in teaching professions as the teachers of middle and high school and professors of college and universities by setting its primary objectives of the study as followings; 1) to assess the degree of general knowledge and attitudes of home economists toward population education in the field of home economics, 2) to verify the problems encountered in implementing population education by home economists in its field, 3) to find an existing status of previous trainings received and other activities of population education of home economists aimed at utilizing these findings as a part of reference materials when the population education is conducted in the field of home economics. In order to attain these objectives described above, the questionnaire was carefully designed to house a total of 40 questions with good combination of multiple-choice and the simple answer questions. The mail questionnaire survey was conducted by establishing teachers of home economics at middle/high schools and college/universities as Senior Home Economists(SHE) who are from public, private liberal arts and vocational schools. The rate of response observed during the survey was 45.6 percent and the findings of the survey research are as follows: 1) Examining the status of the respondents by residence and religion, it was found that 45 percent of middle & high school teachers ar.d 59. 1 percent of college professors are residing in Seoul city area and that the largest percent of them are christian in their religion. Analyzing respondents by their ages, 56 percent of middle/high school teachers are in their 30s, 45 percent of college professors are in their 40s, and 37 percent of college teachers are in their 30s. In addition, 13 percent of the total respondents are found to be unmarried. The study also revealed that 71 percent of the college professors finished Master Degree course and 82 percent of middle/high school teachers are graduated from college level lasting 4 years. Looking over the status cf major fields of respondents, 68.4 percent of middle/high school teachers are specialized in home economic education and the college professors, on the other hand, show relatively even prortion by specializing in the order of food & nutrition science, clothes & textile science and home managerial science. As far as the length of teaching experience is concerned, a relatively longer period of teaching experience is observed in the college professors in comparison with that of middle/high school teachers. In other words, 33.3 percent of middle/high school teachers are experienced in teaching from 6 to 10 years on average while 43.9 percent of college professors show more than 16 years of experience. 2) Examining the status of existing number of children cf the respondents, one boy and one daughter pattern is predominant, showing 28.5 percent in middle/high school teachers and 21.1 percent in college professors. As for the desired number of children of unmarried respondents, it is observed that 43.8 percent of middle/high school teachers desire to have one boy and one girl, and 31.3 percent of college professors want to have one child regardless of the sex. By assessing the degree of awareness of the population education through their students, it is observed that 53 percent of middle/high school teachers and 50 percent of college professors are aware of population education in some extent and that a majority of respondents took the positive attitudes toward an inclusion of family planning components into the formal school education. Another noteworthy to observe is that a total of 84.8 percent out of middle/high school teachers pointed that the population education currently conducted at schools as a part of home economics are less sufficient than it should be. 3) Analyzing the tendency as to whether the respondents were experienced in receiving population education during the time when they were students, 75 percent of college professors and 59 percent of middle/high school teachers responded negative answers in the survey. In the mean time, a total of 50 percent of the respondents replied that they began to acknowledge the importance of population education mainly through the participation of some sort of population-education orientend seminars, experienced by 40 percent of college professors and 80 percent of middle/high school teachers. 4) What it calls attention in this study was to find that 96.5 percent of middle/high school teachers and 72 percent of college professors conduct population education to some extent during their lecture hours and that more than 80 percent of them are never experienced in teaching population and family planning contents in their regular classes. It is, on the other hand, found that no more than once was the response of those who believe themselves that they are experienced in teaching these relevant components to their students. Analyzing the contents of the subjects being taught in the class, a large percent of them are found to be consisted of population and family planning contents. According to this study, the current population education through the formal school is quite inactive. Analyzing the facts, 44.9 percent of the college professors responded that the population and family planning components are quite apart from their specialization which eventually generates lack of interest in the field. 5) It is also noticed through the study that the degree of frequency of commenting on population and family planning contents during the classes was depending significantly on their specializations which means that the degree of frequency varies from a major to another. Those who majored in home managerial science was the first one, as compared to others who majored in different specializations. Glancing over the status of correlations between ages of the respondents and numbers of seminar paticipation, it is quite clear that the aged group participated more than the younger group did, and that the most highest number of participations made by college professors were those who are in 50s. In addition, it is also found that those who are aged 20s and 60s of the respondents were the group who comments least on the contents of population and family planning at their classes. The suggestions and recommendation made through this survey research are as follows. 1) No one denies that the rapid increase of population, as compared to the limited size of land and resources, will certainly affect adversly to an enhancement of individual life quality which will, eventually, bring forth the poverty of the nation. This is the reasson why we are insisting that the world population be controlled up to an optimum level with a matter of global concerns. It is our understading that the primary aim for reducing number of population is believed to be attained only by conducting the systematic and comprehensive population education through the formal schools. Therefore, the role of home economists in the field of population/family planning education is considered very importment due to the fact that an ultimate goal of population education is placed in elevating the quality of family life by having optimum number of children through family planning program. 2) It is quite clear that home economists as teachers of formal school in all level are invited to pay their attention on redefining the ultimate goal of education and that of population education. We also understant that the primary objective of population education is to change the norm and value of the clients by replenishing the students with pertinent knowledge and attitudes on population and its related problems through a sort of education in order to attain the ultimate goal for enhancing the quality of life. There is no exception in the theory of home economics. An altimate goal of home economics is to elevate the general quality of life through an establishment of value existed in daily life. Considering the relations between population education and home economics, it is quite indespensable to bandle population components as an integral part in the field of home economics. We believe, therefore, that the senior home economists positive participation in the effort population control is more needed than it has been. 3) It is also strongly urged that population education should be a part of instructor training course for home economics. In other words, the teacher of home economics should be well aware of population and its problems by teaching interrelationship between population education and home economics, needs, contents and methods of population education during the instructor training courese for home economics. In addition, the senior home economists should be encouraged through positive participation on the short term training by types of domestic and international seminar, workshop, etc. 4) We certainly believe that the population education can not sustain itself without any backing-up of information and findings' of various and comprehensive researches of natural and social sciences. Accordingly, every senior home economist is invited to exert their maximum effort to conduct systematic study with an aim to utilize these findings and information at best in population education in the field of home economics. Therefore, we consider that the development of training material is imminent in order to provide effective and efficient population education through the for training of home economies. It should be noted that these training materials must be carefully designed, tailored and developed to meet the different classes of trainees under the considerations as to whether it is easily adaptable and infusable into the curricula of every field of home economics, and it is acceptable in the degree of difficulty and quality in its contents. 5) It is true that there are many domestic and international research rapers, reports and findings in the field of population education and family planning. However, there is a tendency that the most of research papers are heavily relying on the authors intension and preferences in its expression and publication. Under these circumstances, it is urged that the home economists should aware of the growing need of the technical training in order to keep these available information and research findings reprocessed and redesigned to insure the practical application into the population education in the field of home economics in Korea.

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