• 제목/요약/키워드: step-changed

검색결과 553건 처리시간 0.026초

역마이셀을 이용한 Sm2O3 도핑 CeO2 나노분말의 합성 및 특성 (Synthesis and Characterization of Sm2O3 Doped CeO2 Nanopowder by Reverse Micelle Processing)

  • 김준섭;배동식
    • 한국재료학회지
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    • 제22권4호
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    • pp.207-210
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    • 2012
  • The preparation of $Sm_2O_3$ doped $CeO_2$ in Igepal CO-520/cyclohexane reverse micelle solutions has been studied. In the present work, we synthesized nanosized $Sm_2O_3$ doped $CeO_2$ powders by reverse micelle process using aqueous ammonia as the precipitant; hydroxide precursor was obtained from nitrate solutions dispersed in the nanosized aqueous domains of a micro emulsion consisting of cyclohexane as the oil phase, and poly (xoyethylene) nonylphenylether (Igepal CO-520) as the non-ionic surfactant. The synthesized and calcined powders were characterized by Thermogravimetry-differential thermal analysis (TGA-DTA), X-ray diffraction analysis (XRD), and Transmission electron microscopy (TEM). The crystallite size was found to increase with increase in water to surfactant (R) molar ratio. Average particle size and distribution of the synthesized $Sm_2O_3$ doped $CeO_2$ were below 10 nm and narrow, respectively. TG-DTA analysis shows that phase of $Sm_2O_3$ doped $CeO_2$ nanoparticles changed from monoclinic to tetragonal at approximately $560^{\circ}C$. The phase of the synthesized $Sm_2O_3$ doped $CeO_2$ with heating to $600^{\circ}C$ for 30 min was tetragonal $CeO_2$. This study revealed that the particle formation process in reverse micelles is based on a two step model. The rapid first step is the complete reduction of the metal to the zero valence state. The second step is growth, via reagent exchanges between micelles through the inter-micellar exchange.

척수장애인의 성적적응과 관련요인에 관한 모형구축 (Model Construction of Sexual Adjustment of Patients with Spinal Cord Injury)

  • 강현숙;고정은;서연옥
    • 대한간호학회지
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    • 제30권4호
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    • pp.1018-1034
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    • 2000
  • The purpose of this study was to construct model of sexual adjustment in people with spinal cord injury and to determine factors that relate to sexual adjustment using methodological triangulation. A total of 134 persons who were registered members of spinal cord injury organization and admitted rehabilitation unit in the hospital were included in the study. Participants answered questionnaire concerning importance of life events, sexual concern, sexual adjustment. Qualitative data were collected through semi-structured indepth interviews from 10 individuals with spinal cord injury who were previously included in the quantitative study. Constant compatative method was used to analyze the data. The results were as follows : 1) With respect to eleven other areas of life, sex life ranked the sixth and economic status ranked the highest in terms of importance. However social life ranked the lowest among the 11areas. 2) Among seven topics related to sexuality were methods and techniques to achieve sexual satisfaction, and helping a partner cope emotionally with limitation on sexual dysfunction was the second greastest. 3) The mean score for sexual adjustment was 19.47 which can be considered. 4) A process on how individuals with spinal cord injury adjust to their changed sexual life immerged from the qualitative data. It includs 4 stages: 'stage of loss' 'stage of endeavoring' 'stage of effort' and 'stage of adjustment'. Categories showing context for the action/interaction strategies were 'steadiness' and 'rediscovery as a sexual being'. There were three factors which may stimulate the adjustment process while the others may interrupt it. Those factors included personal matters, family matters and social matters. The individuals may follow each stage step by step but may go back to the previous step depending on the outcomes of their adjustment. 5) There were three factors which may stimulate the adjustment process while the others may interrupt it. Those factors included personal matters, family matters and social matters.

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NSIS 프로토콜을 이용한 사전자원예약 방안 (A Pre-Resource Reservation Mechanism using NSIS protocol)

  • 김선영;변해선;이미정
    • 한국정보과학회논문지:정보통신
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    • 제35권6호
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    • pp.538-548
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    • 2008
  • IETF(Internet Engineering Task Force) NSIS(Next Step in Signaling) 워킹그룹에서는 MN(Mobile Node)의 핸드오버로 인해 데이타 전달 경로가 변경된 경우, 이전 경로와 새로운 경로가 분기 또는 통합되는 지점에 있는 노드인 CRN(Crossover Node)을 발견하는 방안을 제안하였다. 이 방안에서는 CRN 발견을 통해 새로운 경로 상에 자원예약 시그널링 지연을 줄이고 이전 경로와 새로운 경로의 공통경로 상에 중복 자원예약을 피함으로써 핸드오버 이후의 자원예약을 효율적으로 수행한다. 그러나 MN이 핸드오버하는 동안 지속적으로 QoS(Quality of Service)를 보장받기 위해서는 핸드오버 이전에 새로운 경로 상의 사전자원예약이 이루어져야 한다. 그런데 아직 핸드오버하지 않은 MN이 새로운 경로 상에 사전자원예약을 수행하려는 경우에는 기존의 CRN 메커니즘을 적용하기 어렵다. 이에 본 논문에서는 현재 자인이 예약된 경로와 MN이 핸드오버 할 가능성이 있는 하나 이상의 지역의 새로운 경로 상에 CRN이 될 가능성이 있는 노드인 PCRN(Passive Crossover Node)을 발견하고, 이후 새로운 경로 상에 사전자원예약을 수행하는 방안을 제안한다.

ISFET 이온감지기구의 Site Binding 모형 확장과 그 $Si_3N_4$ 수소이온 감지막에의 적용 (Extension of the Site Binding Model for Ion Sensing Mechanism of ISFET and Its Application to the Hydrogen Ion Sensing $Si_3N_4$ Membrane)

  • 서화일;권대혁;이종현;손병기
    • 대한전자공학회논문지
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    • 제25권11호
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    • pp.1358-1366
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    • 1988
  • 독립적인 nitridation step이 포함된 급속 열처리 공정을 이용하여 125-180A 두께의 이중 절연박막을 단결정 실리콘 상에 형성하였다. HCl 가스의 첨가량과 공정시간의 변화에 따른 박막 특성의 변화를 고찰하였고, 이에 따른 박막의 전기적 특성을 관찰하였다. HCl 가스의 첨가에 의해 초기의 산화막 두께의 성장은 현저하게 나타났으나, nitridation 후의 박막두께의 변화는 10A 이하로 매우 저조하였다. 이중 절연박막의 항복전압은 HCl 가스의 첨가량에 비례하여 점차 증가하였고, 절연강도는 furnace나 독립적인 nitridation step이 포함되지 않은 급속 열처리 공정으로 형성한 같은 두께의 박막에 비해 높은 것으로 분석되었다.

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HCI 첨가에 의한 RTO/RTN 이중 절연박막의 전기적 특성 변화 (Effects of the Contents of Hydrochloric Gas on the Electrical Properties of the RTO/RTN Dual Dielectric Films)

  • 김윤태;박성호;배남진;김보우;마동성
    • 대한전자공학회논문지
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    • 제25권11호
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    • pp.1350-1357
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    • 1988
  • 독립적인 nitridation step이 포함된 급속 열처리 공정을 이용하여 125-180A 두께의 이중 절연박막을 단결정 실리콘 상에 형성하였다. HCl 가스의 첨가량과 공정시간의 변화에 따른 박막 특성의 변화를 고찰하였고, 이에 따른 박막의 전기적 특성을 관찰하였다. HCl 가스의 첨가에 의해 초기의 산화막 두께의 성장은 현저하게 나타났으나, nitridation 후의 박막두께의 변화는 10A 이하로 매우 저조하였다. 이중 절연박막의 항복전압은 HCl 가스의 첨가량에 비례하여 점차 증가하였고, 절연강도는 furnace나 독립적인 nitridation step이 포함되지 않은 급속 열처리 공정으로 형성한 같은 두께의 박막에 비해 높은 것으로 분석되었다.

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대만 어린이암재단의 활동 (The Activities of Childhood Cancer Foundation in Taiwan)

  • Lee ChungHsiang
    • 호스피스학술지
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    • 제2권1호
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    • pp.182-192
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    • 2002
  • Childhood Cancer Foundation of ROC(CCFROC) has been founded since 1982. Its goal is to provide comprehensive care for cancer children and their families. And in turn, under the provision of good and complete care, they can be back to the school and society. To achieve this goal, it needs to get every body's effort of the society together. The foundation has been founder under this concept and tried to fulfil this task. The first step is to educate the public to know that childhood cancer can be cured and the process of treatment is long and expensive. In order to reach this life-saving procedure, campaigns for raising money is most important thing. Then, pediatric hematologists / oncologists try to organize study group, named Taiwan Pediatric Qncology Goupp(TPOG), to make treatment protocols for childhood cancers. Its primary purpose is to increase the cure rate to prove the earlier the diagnosis and treatment, the better the prognosis. The second step is to provide full support of medical expenses and further to give help for emergent need to living. Through the varieties of active exercises of cancer children or families, foundation provides opportunities for them to share the experience during the different periods of diseases. The third step is to extend the scope of training activities for many kinds of personnel who devote to the care for cancer children. On the other hand, it promotes the cooperation or communication with international organizations and sets up recreation playing ground in the communities. The aim is to provide a comprehensive and integrated care for cancer children during their education, breeding and even accomplishment period. Besides the financial support of medical care, it provides social services to give psychological support for children and their families, to strengthen doctor-patients or doctor-families relationship. The foundation provides the mourning religious activities to cherish the memory of their children who passed away and to comfort their sadness. Since the childhood cancer is curable, its treatment should be active, comprehensive and it needs to provide to all cancer children without exception. Indeed, the work of CCFROC should be changed according to the environment and different time period. But, it needs the full support from the society. We hope the scope and content of the work will be more extended and its achievement will be better than now in the future.

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BCl3-H2-Ar 분위기를 이용한 2단계 플라즈마 보로나이징 특성 (Characteristics of Two-Step Plasma-Assisted Boronizing Process in an Atmosphere of BCl3-H2-Ar)

  • 남기석;이구현;신평우;송요승;김배연;이득용
    • 한국세라믹학회지
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    • 제43권6호
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    • pp.358-361
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    • 2006
  • A two-step plasma-assisted boronizing process was carried out on the AISI 1045 steel substrate to reduce the pore density introduced by a conventional single plasma boronizing process. The specimens were plasma boronized for 1 h at $650^{\circ}C$ and subsequently far 7 h at $800^{\circ}C$ in an atmosphere of $BCl_3-H_2-Ar$. The boride layer thickness was parabolic in boronizing time, a high HV reading of 1540 was found up to the boride layer thickness of $25{\mu}m$. It was found that the morphology of the boride layer prepared by the two-step boronizing process was changed from a columnar to a tooth-like structure and the pores in the borided steel were eliminated completely in comparison to those synthesized by the conventional single boronizing process, implying that it is highly applicable for enhancing the dense and compact coating properties of the low-alloy steel.

금속산화물(Cu-ferrite)를 이용한 수소제조 연구 (Study on the hydrogen production using the metal oxide (Cu-ferrite))

  • 박주식;서인태;김정민;이상호;황갑진
    • 한국수소및신에너지학회논문집
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    • 제15권3호
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    • pp.201-207
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    • 2004
  • Redox characteristics of metal oxide for hydrogen production by thermochemical water-splitting were investigated. $CuFe_2O_4$ as a redox pair that had a different molar ratio of Cu and Fe were prepared by co-precipitation method. Hydrogen production consisted of water-splitting step and thermal reduction step was performed below 1200K. Redox characteristics of Cu-ferrites were studied using the thermal gravimetric analysis technique. Also, structure change of Cu-ferrite during thermal reduction was investigated using the high temperature controlled XRD. In results, oxygen release of Cu-ferrite during the thermal reduction was initiated at oxygen site combined with Cu. Consequently, oxygen release amount of Cu-ferrite was increased with increase of Cu molar ratio of Cu-ferrite. It was found that thermal reduction of Cu-ferrite was begun at $875^\circ{C}$. It was confirmed that structure of Cu-ferrite was changed to metal and cation excess metal oxide during the thermal reduction step.

여름철 실내 쾌적온도 설정 기준의 적합성 (Suitability of Setting Summer Indoor Temperature for Thermal Comfort)

  • 심현섭;정운선
    • 한국지역사회생활과학회지
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    • 제24권4호
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    • pp.583-589
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    • 2013
  • This study was to provide the information for optimum utilization of the air-conditioning system in the human health and energy saving perspective. Subjects were 17 male and female college students(7 males and 10 females) with normal weight. They wore a short sleeved shirt, knee length trousers, socks, and underwear(0.4clo). They were asked to choose the preferred temperature from different environmental temperatures($28^{\circ}C$, $25^{\circ}C$). The physiological responses were measured and the subjective sensation was voted during the step changes of environmental temperature, starting at $28^{\circ}C$ to $25^{\circ}C$ with $1^{\circ}C$ decrease every 20 minutes. The preferred temperature was $25.9{\pm}0.4^{\circ}C$ for males and $26.9{\pm}0.2^{\circ}C$ for females at $28^{\circ}C$ and $24.8{\pm}0.6^{\circ}C$ for males and $25.6{\pm}0.1^{\circ}C$ for females at $25^{\circ}C$. The preferred temperature decreased about $1.3^{\circ}C$ while the environmental temperature changed $3^{\circ}C$. During the environmental step changes, mean skin temperature decreased more in females while the oxygen uptake and rectal temperature were kept constant for both males and females. We found the preferred temperature was affected by the exposed temperature and the thermal sensation in the condition. Subjects preferred a lower environmental temperature when they were exposed to a lower temperature with cooler sensation. Therefore, in the perspective of human health and energy saving, it is recommended to start setting the air-conditioning temperature higher than the preferred temperature.

Alar Extension Graft를 이용한 콧방울뒤당김의 교정 (The Alar Extension Graft for Retracted Ala)

  • 김현수;노시균
    • Archives of Plastic Surgery
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    • 제36권1호
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    • pp.66-74
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    • 2009
  • Purpose: The importance of the deformities in alar - columellar complex has been underestimated in Asian ethnic groups for the last decades. Fortunately, with increasing familiarity of the open rhinoplasty techniques, the anatomic details of the nasal tip have been pointed up. Definitely, having an interest and demand for improving the sub - normal relationship between the alar rim and columella are indebted for such growing of knowledge about nasal tip anatomy. However, it is true that any single procedure is not settled as versatile and fully confident modality to correct the retracted notching of the alar rim. With this article, I should like to propose another useful option for treating retracted ala. Methods: The author has tried to correct alar rim retraction by means of: (1) Triangular onlay septal cartilage graft on the lower lateral cartilage with the medial end fixed to the anterior surface of the lateral crus(Alar extension graft), (2) Inserting lateral end of the alar extension graft to the vestibular skin pocket in the form of a finger - in - groove, (3) using the vestibular skin in the form of an advancement flap, and (4) using the soft shield graft to prevent possible visible step - off of the alar margin. Results: The author applied an alar extension graft to 16 patients in order to correct a retracted ala for the last 27 months (August, 2003 - October, 2005). The distances from alar rim to long axis of nostril were improved to be within 2 mm in all of the cases, and also the shape of the alar rim changed to a round form. Nostril asymmetry (6%) in one case, temporary palpable step - off (18%) in three cases, temporary visible step - off (6%) in one case, and temporary paresthesia of the tip (25%) in four cases were observed. Conclusion: The alar extension graft is simple and efficacious. It does not need donor sites other than the operative field, and its results are predictable. In particular, since it may give structural intensity to a weak lower lateral cartilage, it may be preferentially used for the correction of a retracted ala that arises from hypoplastic lower lateral cartilage. Moreover intensified lower lateral cartilage also improves the esthetic shape of lobule.