• 제목/요약/키워드: WO3

검색결과 723건 처리시간 0.022초

Anti-wear performance and life evaluation of wheel bearing type greases

  • Kim Jung-Young;Chung Keun-Wo;Kim Young-Wun;Jo Won-Oh
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2004년도 학술대회지
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    • pp.111-116
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    • 2004
  • Li-complex and urea type greases (each 10 species) which were furnished by Chang-Am LS, analyzed anti-wear performance into fretting wear tester & four-bail wear tester. from the results of fretting wear test, the wear volume of Li-complex greases are $4.6\~8.9mg\;and\;8.3\~14.4mg$ with the test of urea greases. The anti-wear performance for 4-ball wear test of greases produced results around 0.5mm at the value of WSD. The grease life performance were evaluated by SKF-ROF Grease Tester and wheel bearing life tester. From the results of SKF-ROF tester, the life performance evaluated by whole working time produced results $50\~300hr$ with the Li-complex greases and 100-1000hr with the urea greases. That is to say, in spite of severe condition at the higher of $10^{\circ}C$ reaction temp, the life performance with Urea type greases are much superior to Li-complex type greases. Prior to wheel bearing life tester, the grease selected performance evaluation(=anti-wear test) are tested by wheel bearing tester. In this results, we can confirm results those are similar with SKF-ROF tester. In this study, we can draw two major conclusions, one is that Li-complex greases are superior to urea greases with anti-wear properties and the other is that urea greases are much superior to Li-complex greases with life performance.

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개에서 역행성 관류를 이용한 요관결석 제거술 (Ureterolithotomy using Retrograde Hydropropulsion in a Dog)

  • 양우종;장화석;정다정;이재훈;강은희;김대현;정욱헌;최치봉;김휘율
    • 한국임상수의학회지
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    • 제28권1호
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    • pp.144-148
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    • 2011
  • A Shihtzu (6-year-old, intact female) was referred to Konkuk University Teaching Animal Hospital for cystic calculus and hydronephrosis of right kiney. The dog was suspected to have ureteral rupture and peritonitis. Radiographic findings included cyctic calculi and right kidney enlargement. On ultrasonographic examination hyperechoic mass with severe acoustic shadowing was located in the right proximal ureter which was dilated. Hydronephrosis of the right kidney, right ureteral caculus and cytic calculus were confirmed by radiography and ultrasonography. Cystotomy for removal of calculus in the bladder and ureterotomy for removal of calculus in the right ureter were performed. Excretory urography (EU) performed one month after surgery revealed that the right ureter was homogeneously opacified and decreased to 3 to 6 mm in diameter. Surgical removal of ureteroliths was appropriate treatment for the ureteral and cystic calculi. The result suggests that ureterotomy is effective treament for the dilation and calculi of ureter.

전이 금속 산화물을 이용한 가시광선 기반 광촉매 분해 (Visible Light-based Photocatalytic Degradation by Transition Metal Oxide)

  • 이수민;박예지;이재훈;라즈쿠마 파텔
    • 멤브레인
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    • 제29권6호
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    • pp.299-307
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    • 2019
  • 광촉매는 물에서 유기 염료를 분해하는 친환경적 기술이다. 산화 텅스텐은 이산화 티타늄에 비해 더 작은 밴드갭을 지니고 있어 광촉매 나노물질로서 활발히 연구되고 있다. 계층적 구조의 합성, 백금 도핑, 나노 복합물 또는 다른 반도체와의 결합 등이 광촉매 분해 효율을 향상시키는 방법들로 연구되고 있다. 이들 방법들은 광 파장의 적색편이를 유도하여 전자 이동, 전자-정공 쌍의 형성과 재결합에 영향을 미친다. 산화 텅스텐의 형태 개질을 통해 앞서 언급한 광촉매 분해 효율을 향상시키는 방법들과 합성에 대해 분석하였으며 금속 산화물과 탄소 복합재를 결합하는 방법이 새로운 물질의 합성이 필요없으며 가장 효율적인 방법으로 조사되었다. 이러한 광촉매 기술은 수처리 분리막기술과 모듈화하여 정수처리 목적으로 사용될 수 있다.

댐건설(建設)로 인한 5대수계(大水系) 본류(本流)의 유황변화(流況變化) 분석(分析) (An Analysis of the Effect of Damming on Flow Duration Characteristics of Five Major Rivers in Korea)

  • 이진원;김형섭;우효섭
    • 대한토목학회논문집
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    • 제13권3호
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    • pp.79-91
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    • 1993
  • 한강, 낙동강, 금강, 섬진강, 영산강 등 우리나라 5대강 본류 주요지점에서의 광범위한 수문자료(水文資料)를 토대로 유황분석(流況分析)을 수행하였다. 우리나라 하천유량 자료의 신뢰도상의 한계를 감안하여, 특히 저수위시수위(低水位時水位)-유량(流量) 관계곡선의 검토 동 본 유황분석에서 이용된 유량자료의 검토에 세심한 배려를 하였다. 본 연구에 의하면, 우리나라 주요 수계의 유황은 상류에 다목적댐 건설로 상당히 개선된 것으로 나타났으며, 이러한 유황개선 효과는 주요 수계의 하상계수(河狀係數)가 댐 건설이전 자연상태에서 300-400 정도이었으나 댐 건설이후 100-300 정도로 감소한 사실과 본 연구에서 제시된 '유황계수(流況係數)'가 대폭 감소한 사실 등에 의해서 확인되어진다. 수계별로는 한강과 영산강의 유황은 상대적으로 안정되어 있고 금강과 섬진강의 유황은 불안정한 것으로 나타났으며, 이러한 결과는 금강과 섬진강에 새로운 수자원 개발의 필요성을 간접적으로 시사하고 있다.

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풍산 개에서 발생한 외상성 요도 절단과 요도 피부 누공의 수술적 교정 (Surgical Repair of the Traumatic Urethral Transection with Urethrocutaneous Fistula in a Pung-san Dog)

  • 이재훈;김성호;양우종;강은희;장화석;정다정;김휘율
    • 한국임상수의학회지
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    • 제27권3호
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    • pp.295-298
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    • 2010
  • 5살의 중성화된 수컷 풍산 개가 서혜부에 지속적인 출혈 증상으로 내원하였다. 내원 5일 전에 멧돼지에게 공격을 받은 병력을 가지고 있었으며, 양성 요도 조영술에서 막성 요도의 파열과 요도 피부 누공이 있음을 확인 하였다. 수술 중 요도 카테터를 장착하여서 요도와 요도 피부 누공을 확인 하였고, 오줌의 누출로 인해 발생한 괴사 조직과 손상된 조직을 제거 하였다. 요도 카테터를 장착하여 요도 문합술을 실시하였다. 술 후 한달 째 배뇨장애나 혈뇨 증상이 없이, 정상적인 배뇨를 유지하였으며, 수술 후 2 달째 실시한 역행성 양성 요도 조영술에서 요도 협착 소견을 보이지 않았다.

Vibrio vulnificus 백신제조원의 혈청형균주 분리 (Isolation of Vibrio vulnificus Serotype Strains for Vaccine Preparation)

  • 주진우
    • 대한미생물학회지
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    • 제22권4호
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    • pp.393-402
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    • 1987
  • The halophilic bacterium Vibrio vulnificus, previously called lactose-positive(L+) Vibrio and Beneckea vulnifica, causes acute, fulminating wound infections and septicemia in humans. Septicemia is very serious infection with a fatality rate of about 50%. Most patients with primary septicemia due to V. vulnificus have preexisting liver disease. V. vulnificus also cause severe wound infections usually after trauma and exposure to marine animals or the marine environment. The mortality rate is not nearly as high as in primary septicemia caused by this organism. In most cases human disease results from ingestion of contaminated seafood or from infection of a wound, frequently of seawater or crab origin. The author made an attempt to isolation of the V vulnificus from seawater, seamud, fish, shellfish, and algae on the southern sea of Korea from January to September in 1987, using for the purpose of vaccine preparation. The author investigated for bacteriological identification, hemolysis and determination of serotypes of isolated V. vulnificus strains. Eighty-five strains(5.9%) out of 1450 specimens collected of V. vulnificus were isolated. The distribution of the 85 isolates were as follows: 21 strains from seawater, 11 strains from seamud, 28 strains from fish, 19 strains from shellfish, and 6 strains from algae, respectively. All 85 isolates were positive reaction on human blood agar. The distribution of serotypes of V. vulnificus isolates were O1 to O8: 13 strains of O1, 6 strains of O2, 11 strains of O3, 9 strains of O4, 10 strains of O5, 7 strains of O6, 15 strains of O7, and 10 strains of O8, respectively. Eighty-one strains showed agglutination with O antisera, but 4 strains failed to show agglutination. In this study, the author suspected that serotypes of V. vulnificus isolates distributed also in the seaside of Korea as well as in most seaside of the world, and new serotypes were in existence in the seaside of Korea except reported up to now.

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페라이트계 금속 산화물 매체 상에서 열화학 메탄 개질 반응 특성 (Reaction Characteristics of Thermochemical Methane Reforming on Ferrite-Based Metal Oxide Mediums)

  • 차광서;이동희;조원준;이영석;김영호
    • 한국수소및신에너지학회논문집
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    • 제18권2호
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    • pp.140-150
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    • 2007
  • Thermochemical 2-step methane reforming, involving the reduction of metal oxide with methane to produce syngas and the oxidation of the reduced metal oxide with water to produce pure hydrogen, was investigated on ferrite-based metal oxide mediums. The mediums, CoFZ, CuFZ, or MnFZ, were composed of the mixture of M(M=Co, Cu or Mn)-substituted ferrite as an active component and $ZrO_2$ as a binder, respectively. The WZ medium, composed of the mixture of $WO_3$ and $ZrO_2$, was also prepared to compare. With an addition of $ZrO_2$, the surface area of the mediums was slightly increased and the sintering of active components was greatly suppressed during the reduction. The higher reactivity of the reduced mediums for water splitting was confirmed by the temperature programmed reaction. From the results of the thermochemical 2-step methane reforming, the reactivity of $CH_4$ reduction and water splitting with ferrite-based metal oxide mediums was relatively higher than that with WZ, and the order of reactivity of the mediums was MnFZ>CoFZ>CuFZ>WZ.

학동기아동을 위한 체질진단검사지 개발 (Development of Sasangin Diagnosis Questionnaire for School Aged Children)

  • 이의주;정용재;곽창규;황민우;유정희;고우석;김경수;고병희
    • 사상체질의학회지
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    • 제19권2호
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    • pp.53-72
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    • 2007
  • 1. Objectives In oriental medicine, there is no method to diagnosis Sasang constitution of school aged children. The objective diagnostic method is necessary to improve the health condition of children. The method must be able to reduce time and to correct subjective error. So the purposes of this study are developing the questionnaire to diagnosis Sasang constitution of school-aged children. 2. Methods The questionnaire consists of selected substance of ${\ulcorner}$Dongyisusebowon${\lrcorner}$, characteristic questionnaire of children and questionnaire for the Sasangin Diagnosis Questionnaire(for adult). Experts, element school children and a scholar on Korean literature revise the questionnaire. 3. Results and Conclusion Experts examed pre-questionnaires and selected the final questionnaries by CVI 0.8 at propriety of contents. Sasangin Diagnosis Questionnaire (SDQ) for Child consists of 84 questions (24 questions for child, 48 questions and 12 questions for doctor).

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C57BL/6N 마우스 탈모모델에서 미세다륜침(MTS)과 황련해독탕 약침액 도포가 모발성장에 미치는 영향 (Effects of Microneedle Therapy System(MTS) and Hwangryeonhaedoktang Pharmacopuncture Solution on Hair Growth in an Alopecia Model of C57BL/6N Mouse)

  • 강나루;윤화정;고우신
    • 한방안이비인후피부과학회지
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    • 제29권1호
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    • pp.47-64
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    • 2016
  • Objective : This study was carried out to investigate the effect of Hwangryeonhaedoktang pharmacopuncture solution (HRHDT) and microneedle therapy system (MTS) on hair growth in an alopecia model of C57BL/6N mice.Methods : Six-week old mice were depilated and separated in 4 groups ; CON (saline), MXD (3% Minoxidil), MTS and HRHDT+MTS. The treatments were applied twice a week for 17 days. The hair growth was determined photographically. The hair density, thickness and length were identified by Folliscope and the weights of body and organs were measured. In dorsal skin tissue, the expression of hair growth-related gene and protein was analyzed by RT-PCR. In addition, the hair follicles in the dermis were observed by H&E staining.Results : The promotion of hair growth was observed in HRHDT+MTS and MTS compared to CON. The hair density, thickness and length were also improved in HRHDT+MTS and MTS compared to CON. The mRNA expression of IGF-1, PRL and PL and the protein expression of VEGF and IGF-1 were increased in HRHDT+MTS and MTS compared to CON. The hair follicles and hair root growth were improved in HRHDT+MTS and MTS compared to CON. In the above results, HRHDT+MTS were more effective than MTS.Conclusions : These results suggest that HRHDT and MTS have a hair growth activity and can be useful for the treatment of alopecia.

음향 자극에 의한 인체 경락의 반응분석 (Analysis of Meridian Response by Sound Stimulus in Body)

  • 김용진;정동명
    • 전자공학회논문지SC
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    • 제38권3호
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    • pp.47-54
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    • 2001
  • 본 논문에서는 경락의 실체를 객관화하기 위한 방법으로서, 경락과 비경락을 음향 자극하고 인체의 임피던스 변화를 분석하였으며, 인체 에너지에 대한 고전 동양의학 이론인 경락순행통로 학설의 타당성을 입증하기 위하여 경락지하수 학설을 제안하였다. 현대의학의 주장과 같이 경락은 그 존재를 증명할 만한 채널이나 파이프 형태의 해부학적 실체를 가지고 있지 않다. 그러나 생체에너지는 인체 안에서 관상구조없이 지하를 흐르는 지하수 흐름과 유사하게 경락을 따라 흐른다. 이러한 모델의 반응특성을 확인하기 위하여, 인체의 경락을 지하수가 흐르는 관로로 보고 지하수를 탐지하는 산업용 음향탐사기법을 적용하기 위하여, 피부와 청각을 구분하여 음향자극하고 경혈과 대조적인 비경혈에서의 인체 임피던스 반응을 분석하였다. 특히 자극 음향과 12경락과의 주파수 상관성을 추출하기 위하여, 5개의 특정 음으로 자극하고 측정전류의 평균치와 변화율을 처리하였다. 분석결과 전류 변화율은 족궐음간경(宮), 수소음심경(商) 30.6%, 족소음신경(角) 33.1%, 족태음비경(徵) 33.9%, 수태음폐경(羽) 30.7%로 대조점과 구별되는 특성을 가지고 있어서, 경락은 비경락과 구별되는 채널 특성을 나타내고 있으며 5개 경락은 5개의 특정 음과 상관성이 있음을 확인하였다.

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