• 제목/요약/키워드: Team Atmosphere

검색결과 180건 처리시간 0.028초

Sol-Gel법을 이용한 구형 UO2 Kernel 제조에 관한 기초연구 (A Basic Study on Spherical UO2 Kernel Preparation Using the Sol-Gel Method)

  • 김연구;정경채;오승철;조문성;나상호;이영우;장종화
    • 한국세라믹학회지
    • /
    • 제42권9호
    • /
    • pp.618-623
    • /
    • 2005
  • HTGR (High Temperature Gas-Cooled Reactor) is highlighted to next generation power plant for producing the clean hydrogen gas. In this study, the spherical $UO_2$ kernel via $UO_3$ gel particles was prepared by the sol-gel process. Raw material of slightly Acid Deficient Uranyl Nitrate (ADUN) solution, which has pH = 1.10 and $[NO_3]/[U]$ mole ratio = 1.93, was obtained from dissolution of $U_3O_8$ powder with conc.-$HNO_3$. The surface of these spherical $UO_3$ gel particles, which was prepared from the broth solution, consisted of 1 M-uranium, 1 M-HMTA, and urea, were covered with the fine crystallite aggregates, and these particles were so hard that crushed well. But the other $UO_3$ gel particles prepared with the broth solution, consisted of 2 M-uranium, 2 M-HMTA, and urea, have soft surface characteristics and an amorphous phase. This type of $UO_3$ gel particles is some chance of doing possibility of high density from the compaction. The amorphous $UO_3$ gel particles was converted to $U_3O_8$ and then $UO_2$ by calcination at $600^{\circ}C\;in\;4\%\;-\;H_2\;+\;N2$ atmosphere.

MOD법으로 제조된 Copper Manganite 박막의 구조 및 NTCR 특성 (Micro-structure and NTCR Characteristics of Copper Manganite Thin Films Fabricated by MOD Process)

  • 이귀웅;전창준;정영훈;윤지선;남중희;조정호;백종후;윤종원
    • 한국전기전자재료학회논문지
    • /
    • 제27권7호
    • /
    • pp.452-457
    • /
    • 2014
  • Copper manganite thin films were fabricated on $SiN_x/Si$ substrate by metal organic decomposition (MOD) process. They were burned-out at $400^{\circ}C$ and annealed at various temperatures ($400{\sim}800^{\circ}C$) for 1h in ambient atmosphere. Their micro-structure and negative temperature coefficient of resistance (NTCR) characteristics were analyzed for micro-bolometer application. The copper manganite film with a cubic spinel structure was well developed at $500^{\circ}C$ which confirmed by XRD and HRTEM analysis. It showed a low resistivity ($47.5{\Omega}{\cdot}cm$) at room temperature and high NTCR characteristics of $-4.12%/^{\circ}C$ and $-2.15%/^{\circ}C$ at room temperature and $85^{\circ}C$, implying a good thin film for micro-bolometer application. Furthermore, its crystallinity was enhanced with increasing temperature to $600^{\circ}C$. However, the appearance of secondary phase at temperatures higher than $600^{\circ}C$ lead to deteriorate the NTCR characteristics.

대기 중에서 가스상 유기염소계 살충제의 반감기 (Half lives of Gaseous Organochlorine Pesticides in Atmosphere)

  • 최민규;천만영
    • Environmental Analysis Health and Toxicology
    • /
    • 제22권2호통권57호
    • /
    • pp.177-184
    • /
    • 2007
  • Gaseous organochlorine pesticides (OCPs : heptachlor epoxide, p, p'-DDE, ${\gamma}-HCH,\;{\alpha}-chlordane,\;{\gamma}-chlordane$ and trans-nonachlor) concentration was measured using PUF high volume sampler from June, 2000 to June, 2002 in the semi-rural atmosphere. The OCPs concentration in atmosphere, which is estimated by the slope (m) of Clausius-Clapeyron equation and phase-transition energy $({\Delta}H)$, was influenced by revolatilization from environmental matrix (soil, water and tree leaves) and a long range transportation of air mass. But the former affected OCPs concentration more than the latter. The degradation rate constants (k) of OCPs calculated using multiple regression analysis and revised standard temperature method were in good agreement each other. The value of k of ${\gamma}-HCH$ was very low as -0.0007, but the range of k of other components were $-0.00l8{\sim}-0.0038$. The half-life $({\tau})$ which was calculated by k of ${\gamma}-HCH$ was 2.6 years-the longest one, but that of heptachlor epoxide was in 0.5 year-the shortest one. $({\tau})\;of\;{\alpha}-chlordane,\;{\gamma}-chlordane$ and trans-nonachlor in technical chlordane was 1.0, 1.1 and 0.7 year respectively.

팀상호작용과 팀메타인지가 대학생 학습공동체 지속참여에 미치는 융복합적 영향 (A study about the convergent effects of team interaction and team metacognition affecting a continuous participation in learning community of university)

  • 노혜란;최미나
    • 디지털융복합연구
    • /
    • 제14권4호
    • /
    • pp.69-78
    • /
    • 2016
  • 이 연구는 대학 학습공동체에 참여한 대학생들의 팀상호작용과 팀메타인지가 학습공동체 활동의 지속참여 의향에 어떠한 융복합적 영향을 주는가를 분석하기 위한 것이다. 팀상호작용 19개 문항과 팀메타인지 17개 문항으로 된 측정도구로, A 대학교 학습공동체 프로그램에 참여한 15개 팀 113명의 대학생을 대상으로 실시하였다. 이항 로지스틱 회귀분석을 통하여 밝힌 연구 결과는 첫째, 학습공동체 지속참여 의향에 팀상호작용 수준과 팀메타인지 수준이 영향을 미치는 것으로 나타났다. 팀상호작용 수준이 높을수록, 팀메타인지 수준이 낮을수록 지속참여할 가능성이 증가하였다. 둘째, 학습공동체 지속참여 의향에 영향을 주는 팀상호작용 요인 중, 학습 횟수가 많을수록, 팀원들이 학습을 위해 서로 격려할수록 지속참여 가능성이 증가하였고, 팀원들이 열심히 활동하지 않을수록, 학습에 몰입하지 않을수록, 학습 시간이 적을수록 지속참여 가능성이 감소하는 것으로 나타났다. 셋째, 학습공동체 지속참여 의향에 영향을 주는 팀메타인지 요인 중, 학습 횟수가 많을수록 참여 의향 가능성이 증가하고, 다양한 학습도구를 사용할수록, 평균 학습시간이 많을수록 참여 의향 가능성이 감소하였다. 이상의 결과를 바탕으로 대학생의 학습공동체 지속참여를 위한 융복합적 지원 방안은 다음과 같다. 팀상호작용을 촉진하기 위해 학습 횟수를 늘리고, 팀원간 상호 격려하도록 지원하여 긍정적인 학습공동체 경험을 유도하고, 팀메타인지 활동의 필요성과 유용성을 학생들이 충분히 인식하도록 효과적인 활용 방법을 지원할 필요가 있다.

환자 및 간호사가 지각하는 치료적인 병실분위기 조성의 저해요인에 대한 조사 연구 (A Study on the Disturbing Factors which Work against Therapeutic Atmosphere & Environment on Hospital Wards as Perceived by Patients and Nurses)

  • 김영혜;한명은
    • 대한간호학회지
    • /
    • 제27권1호
    • /
    • pp.178-188
    • /
    • 1997
  • As a descriptive survey, this study was attempted to get basic data necessary to recognize the factors that disturb the therapeutic atmosphere of hospital wards as perceived by nurses and hospitalized patients, to identify differences between the perceptions of the nurses and of patients. The subjects, 159 patients in Pusan National Hospital and 68 nurses working there were sampled between March 18 and April 13, 1996. The tool used to measure the disturbing factors was an amended form of the one developed by Kim, Mae Ja(1983). The differences between each subject's score for each factor were analyzed using means & SD. and the highest 3 items above the mean score for each factor were collected and compared. The results are described below : 1. Subject's perception of main disturbing factors : patients reported that the main factors were 'loss of role & economic trouble', 'the prognosis of disease', 'the change of daily life' but nurses replied that the main factors were' the prognosis of disease', 'the communication trouble with the medical team & interpersonal relationships'. 'The change of daily life' was not a perceved factor by nurses, but ranked third by the patients. 2. Subject's perception degree of each disturbing factor : (1) among the items related to interpersonal relationship. the patient group reported that the worst disturbance was dur to severely ill patients in the same room' but the nurse group regarded 'greed to monopolize wheelchairs or other supplies' as the worst disturbance. (2) among the items related to physical factors. the patient group regarded 'limitations to wash their body, physical pain and limitations in physical activity' as the worst disturbance, but the nurse group regarded' physical pain', and 'limitations to activity or change of appearance' as the worst disturbance. (3) among the items related to the change of daily activity, the patient group regarded 'the boredom of hospitalization or infavorable diet' as the worst disturbance, but the nurse group regarded 'too much noise or unclean room' as the worst disturbance. (4) among the items related to the communication trouble with medical team, the patient group regarded 'the ignorance of their disease due to poor information. the inability to understand the language of the medical team or the difficulty in seeing physician in time' as the worst disturbance, but the nurse group regarded 'the inability to trust physicians and physician's poor attention to patients' as the worst disturbance.

  • PDF

새로운 방식의 유기박막트랜지스터 패시베이션 기술 (The novel encapsulation method for organic thin-film transistor)

  • 이정헌;김성현;김기현;임상철;조은나리;장진;정태형
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
    • /
    • pp.177-180
    • /
    • 2004
  • In this study, we report a novel encapsulation method for longevity of an organic thin-film transistor (OTFT) using pentaceneby means of an adhesive multiplayerincluded Al film. For encapsulation of OTFTs, the Al film adhered onto the OTFT in a dry nitrogen atmosphere using a proper adhesive. A lifetime, which was defined as the time necessary to reduce mobility to 2% of initial mobility value, was observed from the typical $I_{D-VD}$ characteristics of the field-effect transistor (FET). The initial field effect mobility ${\mu}$ was measured to be $2.0{\times}10^{-1}\;cm^2/Vs$. The characterization was maintained for long times in air. No substantial degeneration occurred. The performance and the stability are probably due to the encapsulation effect.

  • PDF

External Gelation 방법을 이용한 구형 UO3 Gel 입자 제조 (Spherical UO3 Gel Preparation Using the External Gelation Method)

  • 정경채;김연구;오승철;조문성;이영우;장종화
    • 한국세라믹학회지
    • /
    • 제42권11호
    • /
    • pp.729-736
    • /
    • 2005
  • HTGR (High Temperature Gas-cooled Reactor) is spotlighted to next generation nuclear power plant for producing the clean hydrogen gas and the electricity. In this study, the spherical $UO_3$ gel particles were prepared by the external gelation process, and the characteristics of these particles were analyzed the particle shape, composition of precipitate, and thermal decomposition characteristics with the Streoscope, FT-IR, and X-ray diffractometer. Raw material of the ADUN (Acid Deficient Uranyl Nitrate) solution, which has [$NO_3$]/[U] mole ratio = 1.75, was obtained from dissolution of the $U_{3}O_{8}$ powder with concentrated $HNO_3$, and its concentration is 3.5 M-U/l. The broth solution is prepared with the ADUN, urea, PVA, and THFA solution. The droplets of the broth solution was made through a nozzle system. From this study, we obtained the following results; 1) an externel chemical gelation process is a suitable method in the spherical $UO_3$ particle production, 2) the particle shape are changed by an urea mixing time, THFA volume, and the viscosity of the broth solution, 3) the amorphous $UO_3$ particles obtained from these experiments was converted to $U_{3}O_{8}$ and then $UO_2$ by heat treatment in hydrogen atmosphere at $600^{\circ}C$.

Molten-salt 방법에 의해 합성되는 판상형 알루미나 분말 표면에 돌기형성 거동 (Formation of Asperites on the Plate-like Alumina Particles by Molten-salt Method)

  • 이윤주;김보연;신동근;김수룡;권우택;김영희
    • 한국세라믹학회지
    • /
    • 제51권6호
    • /
    • pp.560-565
    • /
    • 2014
  • Alumina nano-asperites were grown on plate-like alumina particles of which the surface had been covered with a capping agent to control the asperite formation sites on the particles. Utilized alumina source for asperite was nano sized ${\gamma}$-alumina, which was prepared by calcination of $Al(OH)_3$ at $600^{\circ}C$; silica suspension was used as the capping agent. Plate like alumina particles were covered by silica suspension and continuously heat-treated to $900^{\circ}C$ with nano sized ${\gamma}$-alumina, as the source material, under molten-salt atmosphere. Asperite growing site were controlled by the degree of coating of the capping agent; 10-20 nanosize of ${\theta}$-alumina were formed on the particle surface. On the other hand, alumina particles without capping agent were observed to undergo only step-like crystal growth during heat-treatment.

공학교육에서의 팀성취분담 협동학습 모형(STAD)의 적용과 효과 (The Study on the Effects of Applying Cooperative Learning Model, Student Teams-Achievement Division to Engineering Education)

  • 백현덕;박진원
    • 공학교육연구
    • /
    • 제15권6호
    • /
    • pp.34-42
    • /
    • 2012
  • Problem solving by homework assignment is a process of practicing what were discussed in classrooms and thus is considered as an essential part of learning procedure in engineering education. We introduced the concept of cooperative learning, Student Teams-Achievement Division(STAD), to improve the students' learning efficiency by in-class problem solving. The instructor explained fundamental concepts, and lecture materials were handed out to compensate for the time of in-class team activity. Brief tests were given after every chapter, and team-based additional credits were given for the improvement comparing the average of previous tests of each student. This attempt of modified STAD was evaluated to have brought about a significant improvement in students' academic achievement, in addition to activating classroom atmosphere.

협동 교육 프로그램을 활용한 팀 구성에 따른 교육효과에 관한 연구 (The Study on Evaluation of Team Grouping Method using Cooperative Education Program)

  • 김현진;김슬기;김명관
    • 한국인터넷방송통신학회논문지
    • /
    • 제10권6호
    • /
    • pp.125-130
    • /
    • 2010
  • 협동학습이란 서로 다른 능력을 갖는 학생들이 주어진 주제에 대한 이해를 증진하기 위하여 다양한 학습 방법을 사용하여 단지 무엇을 배울 것인지 뿐 아니라 팀 구성원들의 학습을 도움으로서 보다 높은 성취도를 갖게 하는 학습방법이다. 본 논문에서는 협동학습 교육프로그램 활용을 위한 효율적인 팀 구성 방법에 대해서 기술한다. 이를 위해 초등학교 학생들을 위한 영어와, 수학 협동학습 프로그램을 구현하였다. 이 협동학습 교육프로그램을 활용하여 학습자들은 협동학습을 수행하였으며 성적, 성별, 친밀도 별 실험을 실시하였다. 결과로 혼성이며 성적이 상호보완적인 팀이 가장 효율적임을 알 수 있었다.