• Title/Summary/Keyword: NCD

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고속도강에 Ti/W 복합중간층을 이용한 나노결정질 다이아몬드 코팅

  • Na, Bong-Gwon;Myeong, Jae-U;Gang, Chan-Hyeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.127-127
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    • 2012
  • 나노결정질 다이아몬드(Nanocrystalline Diamond: NCD) 박막은 고경도와 낮은 마찰계수를 가지고 있어 고속도강과 같은 절삭공구 위에 코팅하여 공구의 성능 향상을 도모하고자 하는 노력이 있어 왔다. 그러나 NCD 박막의 잔류응력이 크고, 철계금속에는 NCD가 증착되지 않는다는 문제점이 있다. 잔류응력 완화와 다이아몬드 핵생성을 위하여 제3의 중간층 재료가 필요하다. 본 연구에서는 Ti과 W을 중간층으로 하여 고속도강(SKH51)에 NCD 박막을 코팅하고 기계적 특성을 비교하였다. 고속도강 위에 DC 마그네트론 스퍼터를 이용하여 2 ${\mu}m$ 두께의 Ti 또는 W 중간층을 증착하고, 그 위에 Microwave Plasma Chemical Vapor Deposition (MPCVD) 방법으로 NCD 박막을 2 ${\mu}m$ 두께로 코팅 한 것과 Ti, W순으로 각각 1 ${\mu}m$ 두께로 증착 후 그 위에 NCD 박막을 2 ${\mu}m$ 두께로 코팅 한 시편을 비교하였다. 세 가지 종류의 시편에 대하여 FESEM을 이용하여 표면과 단면의 형상을 관찰하였고, XRD와 Raman spectroscopy를 통해 NCD 박막의 결정성을 확인하였다. 그리고 Tribometer를 이용해 코팅된 박막의 내마모성을 비교하였으며 Rockwell C Indentation test를 이용하여 접합력을 비교하였다. 연구 결과 Ti/W 복합중간층 위에 코팅된 NCD의 접합력이 가장 우수하였으며 그 다음 W, Ti 순으로 나타났다. NCD와 고속도강의 큰 열팽창계수 차이가 복합중간층으로 인해 줄어들고 잔류응력이 완화되어 접합력이 향상되는 것으로 여겨진다.

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A Study on the Management of Non-Communicable Disease in Fiji (피지에서의 만성병 관리)

  • Kim, Daeseon;Romakin, Pablo;Rafai, Eric;Lee, Chulwoo
    • Journal of Appropriate Technology
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    • v.6 no.2
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    • pp.163-173
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    • 2020
  • For the successful execution of an ODA project, it is necessary to know what areas are weak and necessary to the country of demand exactly. The health sector is also a top priority in most of developing countries. This study was carried out to introduce non-communicable disease (NCD) in Fiji for ODA projects planning. The major causes of death in Fiji in 2016 are diabetes, ischemic heart disease, cerebrovascular disease, chronic kidney disease, lower respiratory infect, asthma in ranking. The major causes of death in Korea in same year are cancer, ischemic heart diseases, cerebrovascular diseases, pneumonia, suicide, diabetes in the order of ranking. The chronic disease as non-communicable disease (NCD) has been increasing continuously due to changes in lifestyle and consumption patterns and population aging in prevalence rate. This global trend is also apparent in Fiji and Korea, reflected in increasing mortality and personal costs for the treatment and management of NCD. The need for a sustained comprehensive treatment tailored for individual patients has suggested from many studies and the development of a systematic program to manage NCD patients to provide such care have been recommended. The Fiji government developed Non-communicable Diseases Strategic Plan 2015-2019 and has tried to reduce the prevalence rate of non-communicable diseases by factors. The WHO global action plan guiding national-level NCD policies requires an NCD prevention and control model at the community level, presenting strategic goals and detailed options for the introduction and application of the approach to communities. It is necessary to develop an NCD prevention and control model, consisting of a strategy of community intervention, education for students and NCD patients, and the legal enactment of NCD that adequately meets the needs of community members.

Nanocrystalline Diamond Coating on Steel with SiC Interlayer (철강 위에 SiC 중간층을 사용한 나노결정질 다이아몬드 코팅)

  • Myung, Jae-Woo;Kang, Chan Hyoung
    • Journal of the Korean institute of surface engineering
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    • v.47 no.2
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    • pp.75-80
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    • 2014
  • Nanocrystalline diamond(NCD) films on steel(SKH51) has been investigated using SiC interlayer film. SiC was deposited on SKH51 or Si wafer by RF magnetron sputter. NCD was deposited on SiC at $600^{\circ}C$ for 0.5~4 h employing microwave plasma CVD. Film morphology was observed by FESEM and FIB. Film adherence was examined by Rockwell C adhesion test. The growth rate of NCD on SiC/Si substrate was much higher than that on SiC/SKH51. During particle coalescence, NCD growth rate was slow since overall rate was determined by the diffusion of carbon on SiC surface. After completion of particle coalescence, NCD growth became faster with the reaction of carbon on NCD film controlling the whole process. In the case of SiC/SKH51 substrate, a complete NCD film was not formed even after 4 h of deposition. The adhesion test of NCD/SiC/SKH51 samples revealed a delamination of film whereas that of SiC/SKH51 showed a good adhesion. Many voids of less than 0.1 ${\mu}m$ were detected on NCD/SiC interface. These voids were believed as the reason for the poor adhesion between NCD and SiC films. The origin of voids was due to the insufficient coalescence of diamond particles on SiC surface in the early stage of deposition.

금속중간층을 이용한 나노결정질 다이아몬드 박막 코팅

  • Na, Bong-Gwon;Myeong, Jae-U;Gang, Chan-Hyeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.99-99
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    • 2013
  • 나노결정질 다이아몬드(Nanocrystalline Diamond: NCD) 박막은 고경도와 낮은 마찰계수를 가지고 있어 초경합금이나 고속도강과 같은 절삭공구 위에 코팅하여 공구의 성능 향상을 도모하려는 노력이 있어 왔다. 그러나 NCD 박막의 잔류응력이 크고, 초경합금과 철계 금속에 NCD가 증착되지 않는다는 문제점이 있다. 따라서 잔류응력 완화와 다이아몬드 핵생성을 위하여 제3의 중간층 재료가 필요하다. 본 연구에서는 W과 Ti을 중간층으로 하여 초경합금(WC-Co)과 고속도강(SKH51)에 NCD 박막을 코팅하고 기계적 특성을 비교하였다. 초경합금 또는 고속도강기판 위에 W 또는 Ti 중간층을 DC magnetron sputter를 이용해 각 1 ${\mu}m$의 두께로 증착하고 그 위에 MPCVD (Microwave Plasma Chemical Vapor Deposition)를 이용해 NCD 박막을 2${\mu}m$의 두께로 코팅하였다. FESEM을 이용하여 표면과 단면의 형상을 관찰하였고, XRD와 Raman spectroscopy를 통해 NCD 박막의 결정성을 확인하였다. 그리고 tribology test를 실시하여 코팅된 박막의 내마모성을 비교하였으며, Rockwell C indentation test를 이용하여 밀착력을 비교하였다. 초경합금에 적용 시, W이 Ti보다 중간층으로서 더 우수한 것으로 나타났으며 이는 열팽창계수 차이에 의한 잔류응력의 차이에 의한 것으로 여겨진다. 중간층 두께에 따른 박막의 기계적 특성 변화를 알아보기 위해 W 중간층의 두께를 1, 2, 4 ${\mu}m$로 변화를 주었다. 중간층 두께가 2 ${\mu}m$ 이상일 때 박막의 밀착력이 증가되는 것으로 나타났다. 고속도강 위에 같은 방법으로 1 ${\mu}m$의 W 또는 Ti 중간층 위에 2 ${\mu}m$의 NCD 박막을 코팅한 시편들은 초경합금에 코팅한 것과 달리 두 시편 모두 낮은 밀착력을 나타내었다. 열팽창계수 차이에 의한 잔류응력을 완화하기 위해 고속도강에 W/Ti 복합박막을 중간층으로 Ti, W순으로 각각 1 ${\mu}m$ 두께로 증착 후 그 위에 NCD 박막을 2 ${\mu}m$ 두께로 코팅 한 후 특성을 비교하였다. Ti/W 복합 중간층 위에 코팅된 NCD 박막의 밀착력이 W 혹은 Ti 단일 중간층에 코팅된 박막에 비해 우수한 것으로 나타났다. 그러나 실제 공구에 적용하기에는 박막의 밀착력 개선이 요구되며 이를 위해서 더 연구가 필요하다.

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N6/NCD 복합방사 소재개발 및 제품개발에 관한 연구

  • Sim, Seung-Beom;Seo, Mal-Yong;Choe, Gwang-Seok;Son, Hyeon-Sik
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2009.11a
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    • pp.145-146
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    • 2009
  • This is studies about development of light nylon fabric and development of low denier NCD/nylon6 filament using mixed spinning technique of nylon6 and NCD(Nylon Cation Dyeable) polymer. We study how the manufactured fabrics effect on downproof & windproof properties according to conditions of low denier N/NCD filament yarn, fabrication, and dyeing and finishing.

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Growth of Nanocrystalline Diamond on W and Ti Films (W 및 Ti 박막 위에서 나노결정질 다이아몬드의 성장 거동)

  • Park, Dong-Bae;Myung, Jae-Woo;Na, Bong-Kwon;Kang, Chan Hyoung
    • Journal of the Korean institute of surface engineering
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    • v.46 no.4
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    • pp.145-152
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    • 2013
  • The growth behavior of nanocrystalline diamond (NCD) film has been studied for three different substrates, i.e. bare Si wafer, 1 ${\mu}m$ thick W and Ti films deposited on Si wafer by DC sputter. The surface roughness values of the substrates measured by AFM were Si < W < Ti. After ultrasonic seeding treatment using nanometer sized diamond powder, surface roughness remained as Si < W < Ti. The contact angles of the substrates were Si ($56^{\circ}$) > W ($31^{\circ}$) > Ti ($0^{\circ}$). During deposition in the microwave plasma CVD system, NCD particles were formed and evolved to film. For the first 0.5h, the values of NCD particle density were measured as Si < W < Ti. Since the energy barrier for heterogeneous nucleation is proportional to the contact angle of the substrate, the initial nucleus or particle densities are believed to be Si < W < Ti. Meanwhile, the NCD growth rate up to 2 h was W > Si > Ti. In the case of W substrate, NCD particles were coalesced and evolved to the film in the short time of 0.5 h, which could be attributed to the fact that the diffusion of carbon species on W substrate was fast. The slower diffusion of carbon on Si substrate is believed to be the reason for slower film growth than on W substrate. The surface of Ti substrate was observed as a vertically aligned needle shape. The NCD particle formed on the top of a Ti needle should be coalesced with the particle on the nearby needle by carbon diffusion. In this case, the diffusion length is longer than that of Si or W substrate which shows a relatively flat surface. This results in a slow growth rate of NCD on Ti substrate. As deposition time is prolonged, NCD particles grow with carbon species attached from the plasma and coalesce with nearby particles, leaving many voids in NCD/Ti interface. The low adhesion of NCD films on Ti substrate is related to the void structure of NCD/Ti interface.

Heat Spreading Properties of CVD Diamond Coated Al Heat Sink (CVD 다이아몬드가 코팅된 알루미늄 방열판의 방열 특성)

  • Yoon, Min Young;Im, Jong Hwan;Kang, Chan Hyoung
    • Journal of the Korean institute of surface engineering
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    • v.48 no.6
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    • pp.297-302
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    • 2015
  • Nanocrystalline diamond(NCD) coated aluminium plates were prepared and applied as heat sinks for LED modules. NCD films were deposited on 1 mm thick Al plates for times of 2 - 10 h in a microwave plasma chemical vapor deposition reactor. Deposition parameters were the microwave power of 1.2 kW, the working pressure of 90 Torr, the $CH_4/Ar$ gas ratio of 2/200 sccm. In order to enhance diamond nucleation, DC bias voltage of -90 V was applied to the substrate during deposition without external heating. NCD film was identified by X-ray diffraction and Raman spectroscopy. The Al plates with about 300 nm thick NCD film were attached to LED modules and thermal analysis was carried out using Thermal Transient Tester (T3ster) in a still air box. Thermal resistance of the module with NCD/Al plate was 3.88 K/W while that with Al plate was 5.55 K/W. The smaller the thermal resistance, the better the heat emission. From structure function analysis, the differences between junction and ambient temperatures were $12.1^{\circ}C$ for NCD/Al plate and $15.5^{\circ}C$ for Al plate. The hot spot size of infrared images was larger on NCD/Al than Al plate for a given period of LED operation. In conclusion, NCD coated Al plate exhibited better thermal spreading performance than conventional Al heat sink.

Strategy of Research for Developing Model of Community Based Non-Communicable Diseases Control and Prevention (지역사회 기반 만성질환 관리모형 구축을 위한 연구방안)

  • Park, Yoon Hyung
    • Health Policy and Management
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    • v.26 no.1
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    • pp.1-3
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    • 2016
  • The prevalence of non-communicable disease (NCD) has been continuously increasing due to population ageing, and the change in consumption and lifestyle patterns. Cancers, cerebrovascular diseases, and hypertensive diseases have been the major causes of deaths in the Republic of Korea since 1983. Numerous studies have suggested the need for a sustained comprehensive treatment tailored for individual patients and recommend the development of a systematic program to manage NCD patients to provide such care. It's necessary to develop the Korean model of the community based NCD prevention and control, consisting strategy of community movement, education for the NCD patients, and partnership the primary care clinic with public health organization to meet the needs in community people.

A syudy of Algorithm using the method of HLMF and NCD on the 'Lak-seo nine palace' (HLMF 및 NCD 기법을 적용한 낙서구궁의 Algorithm에 관한 연구)

  • Han, Doung-Soo;Cho, Sung-Je
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.4 no.2
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    • pp.141-151
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    • 2011
  • This paper aim at producing a Digital Modeling of the science of divination using a study of a new method with a mathematical function on "Lak-seo nine palace". For that goal, we must study a new law of moving forward and a new common difference on 'Lak-seo nine place'. We call this "the method of HLMF and NCD". Therefore, When drawing up 'a plan of Lak-seo nine palace', we will provide convenience in the field, so we don't make it by handwrite, but will produce it by a digital mode.

Strategies to reduce risk factors of non-communicable diseases in South Korea (만성질환 위험요인 감소를 위한 전략과 방향)

  • Khang, Young-Ho
    • Korean Journal of Health Education and Promotion
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    • v.33 no.4
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    • pp.1-9
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    • 2016
  • Objectives: This review is to suggest strategies to reduce risk factors of non-communicable diseases (NCD) in South Korea. Methods: Prior research findings on the burden of NCD and associated risk factors and the effectiveness of intervention programs were reviewed. Strategies regarding the control of NCD risk factors were conceived. Results: The author presented research findings from the Global Burden of Disease study on the burden of non-communicable disease (NCD) and associated risk factors in South Korea. Strengths and limitations of population and high-risk strategies for preventing NCDs were introduced. The author also reviewed the evidence on the effectiveness of multiple cardiovascular risk factor interventions and community-based intervention programs on cardiovascular diseases conducted in industrialized countries. Finally, strategies to reduce NCD risk factors in South Korea were suggested. Conclusions: The evidence-based interventions and the importance of population strategies in NCD prevention were highlighted. The author indicated that strategies employed by unhealthy commodity industries to undermine effective public health policies and programs should be actively monitored. It has been suggested that effective high-risk strategies with ecological models to address social risks rather than medical risks among disadvantaged population should be further developed in South Korea.