• Title/Summary/Keyword: SiC filament

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Inhibitory effects of Electroacupuncture & Acupuncture at Hu-gye(SI03), Wijung(BL40),Hu-gye(SI03)ㆍWijung(BL40) on Neuropathic Pain in Rats (위중(委中), 후계(後谿), 위중배후계(委中配後谿) 전침(電鍼) 및 침자(鍼刺)가 백서(白鼠)의 신경병리성(神經病理性) 동통(疼痛) 억제(抑制)에 미치는 영향(影響))

  • Oh, Chang-log;Na, Chang-su;Lyu, Chung-yeol;Cho, Myung-rae
    • Journal of Acupuncture Research
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    • v.22 no.1
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    • pp.77-90
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    • 2005
  • Objective : Neuropathic pain sometimes arises from a partial peripheral nerve injury. This kind of pain is usually accompanied by spontaneous burning pain, allodynia and hyperalgesia. It has been well known that acupuncture is effective to the pain control from ancient time in Asia. However, it is not clear whether Electroacupuncture(EA) & Acupuncture(AC) can control neuropathic pain effectively. The aim of this study is to examine if Electroacupuncture&Acupuncture at Hu-gye(SI03), Wijung(BL4O), Hu-gye(SI03) Wijung(BL40) may be effective to the neuropathic pain (mechanical allodynia cold allodynia) in a rat model of neuropathic pain. Methods : A rat model of neuropathic pain was made by injurying tibial nerve and sural nerve while common peroneal nerve was maintained. After the neuropathic surgery, we examined if the rats exhibited the behavioral signs allodynia. The allodynia was assessed by stimulating the medial malleolus with von frey filament and acetone. Three weeks after the neuropathic surgery, electroacupuncture &, acupuncture stimulation was delivered to Hu-gye(SI03), Wijung(BL40), Hu-gye(SI03) Wijung(BL40) one time a day for one week. After that we examined the withdrawal response of neuropathic rats' legs by von frey filament and acetone stimulation, c-fos and AchE(Acetylcholine esterase) in the periaqe- ductal gray(PAG) of neuropathic rats' brain. Results : 1. Electroacupuncture&Acupuncture at Hu-gye(SI03), Wijung(BL40), Hu-gye(SI03) Wijung(BL4O) significantly decreased the withdrawal response of mechanically allodynia in EA-BL40+SI03 group and AC-SI03 group as compared with control group on 6th day. 2. Electroacupuncture &Acupuncture at Hu-gye(SI03), Wijung(BL40), Hu-gye (SI03) Wijung (BL40) significantly decreased the withdrawal response of chemical allodynia(cold allodynia) in EA-SI03 group, EA-BL40+SI03 group and AC-SI03 group as compared with control group on 6th day. 3. Electroacupuncture & Acupuncture at Hu-gye ( SI03), Wijung (BL40), Hu-gye (SI03) Wijung(BL40) significantly decreased the expression of c-fos in the periaqe- ductal gray(PAC) of neuropathic rats' brain in EA-BL40+SI03 group and AC-SI03 group as compared with control group. 4. Electroacupuncture&Acupuncture at Hu-gye(SI03), Wijung(BL40), Hu-gye (SI03) Wijung(BL40) significantly decreased the expression of AchE in the periaqe- ductal gray(PAG) of neuropathic rats' brain in EA-BL40+SI03 group and AC-SI03 group as compared with control group. Conclusions : Based on the above results it is assumed that Electroacupuncture at Hu-gye(SI03) Wijung(BL40) and Acupuncture at Hu-gye(SI03) can help the treatment of neuropathic pain.

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A Study on the Possibility of Using Fire-Retardant Working Cloth Made from Silicon Carbide (SiC) Composite Spun Yarns (Silicon Carbide (SiC) 복합방적사로부터 제조된 원단의 방화복 활용 가능성에 관한 연구)

  • Kang, Hyun-Ju;Kang, Gun-Woong;Kwon, Oh-Hoon;Kwon, Hyeon-Myoung;Hwang, Ye-Eun;Jeon, Hye-Ji;Joo, Jong-Hyun;Park, Yong-Wan
    • Science of Emotion and Sensibility
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    • v.24 no.4
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    • pp.149-156
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    • 2021
  • The mechanical properties of a woven fabric made of SiC (silicon carbide) fibers were determined in this study using the KES-FB system. The woven fabric is used in high heat settings above 1500℃. Composite spun yarns were used to create SiC fibers. By analyzing the wearing properties, we studied the prospect of using the textiles as fire-retardant work clothes. Mechanical properties determine the wearing attributes. Therefore, the tensile linearity (LT), tensile resilience (RT), and shear stiffness (G) values of the fabric varied according to the yarn type (filament or spun yarn). The thickness, weight per square meter, and density of the fabric were found to have an effect on the shear hysteresis (2HG) and compression resilience (RC) values. In terms of wearable clothing qualities, the fabric qualities of the SiC composite yarn demonstrated the highest ratio of compressive energy to thickness (WC/T), which indicates bulkiness. The fabric manufactured from SiC composite yarns passed the KFI criteria for carbonation length and cumulative flame time in the flame-retardant test. Therefore, we discovered that the material can be used as a fire-resistant work cloth.

Effects of Acupuncture at SI3, BL40, SI3·BL40 on Neuropathic pain control and c-Fos protein expression in rats (후계(後谿), 위중(委中), 후계배위중(後谿配委中) 침자(鍼刺)가 백서(白鼠)의 신경병리성(神經病理性) 동통억제(疼痛抑制) 및 c-Fos 단백(蛋白) 발현(發顯)에 미치는 영향(影響))

  • Jung, Jung-hee;Yun, Dae-whan;Na, Chang-su;Ryu, Choong-ryul;Yun, Yeo-chung;Cho, Myung-rae
    • Journal of Acupuncture Research
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    • v.21 no.1
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    • pp.240-251
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    • 2004
  • Objective: We have studied to know effects of acupuncture at SI3, BL40, SI3 BL40 on mechnical allodynia, cold allodynia and c-fos protein expression in a model of neuropathic pain of rat. Methods: A model of neuropathic pain was made by injuring tibial nerve and sural nerve while common peroneal nerve was maintained. after 2 weeks, we performed behavioral tests for 7 days to try out mechnical allodynia using von frey filament and cold allodynia using acetone, which are calculated by counting withdrawal response on foot. Rat brains removed and sliced on 8th days. Serial sections were immunohistochemically reacted with polyclonal c-fos antibody. The numbers of c-Fos protein immunoreactive neurons in the central gray were examined using scion image program. Results: Mechanical allodynia in the SI3, BL40, SI3 BL40 groups were diminished compared with the control group. Cold allodynia in the SI3, BL40, SI3 BL40 groups were diminished compared with the control group. c-Fos protein expression on the central gray in the SI3 group were lower than that of the control group. Conclusions: We have noticed that acupuncture at SI3, BL40, SI3 BL40 diminished mechanical allodynia and cold allodynia in a model of neuropathic pain compared with the control group. c- Fos protein expression in the central gray of that group was also decreased compared with the control group. pain control using acupunture was accumulated as time goes by. This study can be used as a basic resource on a study and a treatment of pain.

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Fused Filament Fabrication of Poly (Lactic Acid) Reinforced with Silane-Treated Cellulose Fiber for 3D Printing

  • Young-Rok SEO;Birm-June KIM
    • Journal of the Korean Wood Science and Technology
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    • v.52 no.3
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    • pp.205-220
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    • 2024
  • Various polylactic acid (PLA) blends were reinforced with untreated or silane-treated micro-sized cellulose fiber (MCF), successfully prepared as 3D printing filaments and then printed using a fused filament fabrication (FFF) 3D printer. In this study, we focused on developing 3D-printed MCF/PLA composites through silane treatment of MCF and investigating the effect of silane treatment on the various properties of FFF 3D-printed composites. Fourier transform infrared spectra confirmed the increase in hydrophobic properties of silane-treated MCF by showing the new absorption peaks at 1,100 cm-1, 1,030 cm-1, and 815 cm-1 representing C-NH2, Si-O-Si, and Si-CH2 bonds, respectively. In scanning electron microscope images of silane-treated MCF filled PLA composites, the improved interfacial adhesion between MCF and PLA matrix was observed. The mechanical properties of the 3D-printed MCF/PLA composites with silane-treated MCF were improved compared to those of the 3D-printed MCF/PLA composites with untreated MCF. In particular, the highest tensile and flexural modulus values were observed for S-MCF10 (5,784.77 MPa) and S-MCF5 (2,441.67 MPa), respectively. The thermal stability of silane-treated MCF was enhanced by delaying the initial thermal decomposition temperature compared to untreated MCF. The thermal decomposition temperature difference at T95 was around 26℃. This study suggests that the effect of silane treatment on the 3D-printed MCF/PLA composites is effective and promising.

Effects of Oxygen Addition on the Growth Rate and Crystallinity in Diamond CVD (다이아몬드 CVD에서 산소혼입이 증착속도 및 결정성에 미치는 영향)

  • 서문규;이지화
    • Journal of the Korean Ceramic Society
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    • v.27 no.3
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    • pp.401-411
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    • 1990
  • Deposition of diamond films on Si(100) from the mixtures of methane and hydrogen were investigated using hot W filament CVD method. The nucleation density could be increased thousandfold by surface treatment with SiC powder. Upon oxygen addition to the mixture, crystal facets became developed more clearly by selectively removing non-diamond carbons, but the film growth rate generally decreased. However, at a very high methane content(e.g. 10%), a small amount of oxygen addition has resulted in an increase in the film deposition rate presumably by promotion of methane decomposition. When the gas pressure was varied, the growth rate exhibited a maxiumum at around 20torr and the film crystallinity steadily improved with the pressure increase. The observed variation of the growth rate by oxygen addition was discussed in terms of its role in the pyrolysis and the subsequent gas phase reactions.

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UHV Materials (초고진공계재료)

  • 박동수
    • Proceedings of the Korean Vacuum Society Conference
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    • 1998.02a
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    • pp.24-24
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    • 1998
  • 반도체장비를 포함하는 초고진공장비의 園훌化가 급속히 그리고 절실히 요구되고 있는 것이 현실정이다. 當面해서 실현할 국산진공장비의 대상은 廣範圍하다. 즉, 각종 진공 pump ( (rotary, dry, diffusion, cryo, ion, turbo melecular pump), 진공 chamber, 진공 line, gate valve 를 위 시 한 진공 V머ve, flange, gasket, fl않d야lU, mainpulater 퉁 진공 部品이 다. 진공계 의 핵심 은 適切하고 優良한 진공재료의 선태파 사용이다. 진공장비는 사용자가 원하는 진공도를 원하 는 시간 동안 륨空度를 유지해 주어야 한다. 진공재료 선태의 기준사항은:(1) 기체의 透過성 (2) 薰했훌 (3) 혔體放出특성 - -outgassing과 degassing- (4) 機械的 량훌度 (5) 온도 의존성 (6) 化學톡성 (7) 加I성 및 鎔接 성 (8) 課電특성 (9) 磁氣특성 (10) 高速함子 및 放射線 특성 (11) 經濟성 및 調達생 둥이 다. 우량한 초고진공계재료는 풍부하게 개발되어 왔고, 또 新材料들이 개발되고 있다. 여기에서는 주로 초고진공 내지는 극고진공계의 構造材料, 機能材料, 部品材料 일반파 몇가지 신재료의 특 성에 관해서 記述한다. M Mild SteeHSAE, 1112, 1010, 1020, 1022, etc)., S Stainless SteeHAlSI, 304, 304L, 310, 316, 321, 347): 구조재료, chamber, fl하1ges A Aluminum과 Alloys (1060, 1100, 2014, 4032, 6(뻐1): 구조재료, chamber, flanges, gaskets A AI, Al 떠loy는 SS에 代替하는 역 할올 시 작하고 있다. C Copper, Copper Alloys(C11$\alpha$)0, C26800, C61400, Cl7200): 내장인자, gasket, cryopanel, tubing T Titanium, Ziriconium, Haf띠um 및 Alloys: 특히 Ti은 10n pump 용 getter material 이 외 에 U UHV,XHV용 chamber계로서 관심올 끌고 있다. N Nickel, Nickel Alloys (200, 204, 211, monel, nichrome): 부식 방지 , 전자장치 , 자기 장치 귀 금속(Ag, Au, Pt, Pd, Rh, Ir, Os, Ru): 보조부품, gasket, filament, coating, thermocouple, 접 합부위 T TiC, SiC, zrC, HfC, TaC 둥의 탄화물과, BN, TiN, AlN 동의 질화물, 붕화물이 둥장하고 었 다. 유리: Soda Lime, Borosilicate, Potash Soda Lead: View Port, Chamber envelope C Ceramics: AlZ03, BeO, MgO, zrOz, SiOz, MgOzSiOz, 3Alz032SiOz, Z$textsc{k}$hSiOz S상N4: e electrical, thermal insulators, crucibles, boats, single crystals, sepctr려 windows 저자는 최근 저자들이 발견한 Zr-Ti-Cu-Ni-Be amorphous alloys coated cham뾰r가 radiation p proof로 이용될 수 있는 사실을 점검하고 었다 .. Z.Y. Hua 들은 Cs3Sb를 새로운 photocathode 재료로 보고하고 있다.

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Effect of growth temperature on the growth and properties of carbon-nanotube prepared by Hot-filamnet PECVD method (Hot-filament 화학기상 증착법으로 성장시킨 성장온도에 따른 탄소나노튜브의 성장 및 특성)

  • Kim, Jung-Tae;Park, Yong-Seob;Kim, Hyung-Jin;Lee, Sung-Uk;Choi, Eun-Chang;Hong, Byung-You
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.120-120
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    • 2006
  • 탄소나노튜브는 nm급의 크기에 높은 전기전도도, 열전도 효율, 감한 기계적 강도 등의 장점을 가지며, FED(Field Emission Display), 극미세 전자 스위칭 소자, SET(Single Electron Transistor), AFM(Atomic Force Microscope) tip등 여러 분야로의 응용을 연구하고 있다. 본 연구에서는 탄소나노튜브를 Si 웨이퍼 위에 Ni/Ti 금속층을 촉매층으로 사용하고, 암모니아($NH_3$)가스와 아세틸렌 ($C_2H_2$)가스를 각각 희석가스와 성장원으로 사용하여 합성하였다. 탄소나노튜브의 성장은 Hot filament 화학기상증측(HFPECVD) 방식을 사용하였으며, 이 방법은 다량의 합성, 높은 균일성, 좋은 정렬 특성등의 장점을 가진다. 성장 온도는 탄소나노튜브의 성장 특성을 변화시키는 중요한 요소이다. 성장 온도에 따라 수직적 성장, 성장 밀도등의 특성 변화를 관찰하였다. 성장된 탄소나노튜브층 성분 분석은 에너지 분산형 X-선 측정기(EDS)를 통해 관찰하였고, 끝단에 촉매층이 존재하는 30~50 nm 폭을 가진 다중벽 탄소나노튜브를 고배율 투과전자현미경(HRTEM) 분석을 통해 관찰하였다. 전계방사 주사전자현미경(FESEM) 분석을 동해 1~3${\mu}m$의 길이를 가진 탄소나노튜브가 높은 밀도로 성장된 것을 확인하였다.

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Machining Characteristics of SiC reinforced Composite by multiple diamond-coated drills (다이아몬드 피복공구에 의한 SiC 강화 복합재료의 절삭특성)

  • M. Chen;Lee, Y. M.;S. H. Yang;S. I. Jang
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.533-537
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    • 2003
  • Compared to sintered polycrystalline diamond (PCD), the deposited thin film diamond has a great advantage on the fabrication of cutting tools with complex geometries such as drills. Because of high performance in high speed machining non-ferrous difficult-to-cut materials in the field of automobiles industry, aeronautics and astronautics industry, diamond-coated drills find large potentialities in commercial applications. However, the poor adhesion of the diamond film on the substrate and high surface roughness of the drill flute adversely affect the tool lift and machining quality and they become the main technical barriers for the successful development and commercialization of diamond-coated drills. In this paper, diamond thin films were deposited on the commercial WC-Co based drills by the electron aided hot filament chemical vapor deposition (EACVD). A new multiple coating technology based on changing gas pressure in different process stages was developed. The large triangular faceted diamond grains may have great contribution to the adhesive strength between the film and the substrate, and the overlapping ball like blocks consisted of nanometer sized diamond crystals may contribute much to the very low roughness of diamond film. Adhesive strength and quality of diamond film were evaluated by scanning electron microscope (SEM), atomic force microscope (AFM), Raman spectrum and drilling experiments. The ring-block tribological experiments were also conducted and the results revealed that the friction coefficient increased with the surface roughness of the diamond film. From a practical viewpoint, the cutting performances of diamond-coated drills were studied by drilling the SiC particles reinforced aluminum-matrix composite. The good adhesive strength and low surface roughness of flute were proved to be beneficial to the good chip evacuation and the decrease of thrust and consequently led to a prolonged tool lift and an improved machining quality. The wear mechanism of diamond-coated drills is the abrasive mechanical attrition.

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Operating Characteristics of Amorphous GeSe-based Resistive Random Access Memory at Metal-Insulator-Silicon Structure (금속-절연층-실리콘 구조에서의 비정질 GeSe 기반 Resistive Random Access Memory의 동작 특성)

  • Nam, Ki-Hyun;Kim, Jang-Han;Chung, Hong-Bay
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.7
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    • pp.400-403
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    • 2016
  • The resistive memory switching characteristics of resistive random access memory (ReRAM) using the amorphous GeSe thin film have been demonstrated at Al/Ti/GeSe/$n^+$ poly Si structure. This ReRAM indicated bipolar resistive memory switching characteristics. The generation and the recombination of chalcogen cations and anions were suitable to explain the bipolar switching operation. Space charge limited current (SCLC) model and Poole-Frenkel emission is applied to explain the formation of conductive filament in the amorphous GeSe thin film. The results showed characteristics of stable switching and excellent reliability. Through the annealing condition of $400^{\circ}C$, the possibility of low temperature process was established. Very low operation current level (set current: ~ ${\mu}A$, reset current: ~ nA) was showed the possibility of low power consumption. Particularly, $n^+$ poly Si based GeSe ReRAM could be applied directly to thin film transistor (TFT).

Performance of BDD Electrodes Prepared on Various Substrates for Wastewater Treatment (다양한 기판에 형성된 BDD 전극의 폐수처리 특성)

  • Kwon, Jong-Ik;You, Mi-Young;Kim, Seo-Han;Song, Pung-Keun
    • Journal of Surface Science and Engineering
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    • v.52 no.2
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    • pp.53-57
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    • 2019
  • Stability and activity of boron doped diamond (BDD) electrode are key factors for water treatment. In this study, BDD electrodes were prepared on various substrates such as Nb, Si, Ti, and $TiN_x/Ti$ by hot filament chemical vapor deposition (HFCVD) method. BDD/Ti film showed the delamination between BDD and Ti substrate due to the formation of TiC layer caused by diffusion of carbon. On the other hand, $BDD/TiN_x/Ti$ showed remarkably improved stability, compared to BDD/Ti. It was confirmed that $TiN_x$ intermediate layer act as barrier layer for diffusion of carbon. High potential window of 2.8 eV was maintained on the $BDD/TiN_x/Ti$ electrode and, better wastewater treatment capability and longer electrode working life than BDD/Nb, BDD/Si and BDD/Ti were obtained.