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

  • Kim Jung-Young;Chung Keun-Wo;Kim Young-Wun;Jo Won-Oh
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2004.11a
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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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Ureterolithotomy using Retrograde Hydropropulsion in a Dog (개에서 역행성 관류를 이용한 요관결석 제거술)

  • Yang, Wo-Jong;Chang, Hwa-Seok;Chung, Dai-Jung;Lee, Jae-Hoon;Kang, Eun-Hee;Kim, Dae-Hyun;Chung, Wook-Hun;Chi-Bong, Choi;Kim, Hwi-yool
    • Journal of Veterinary Clinics
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    • v.28 no.1
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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.

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

  • Lee, Soomin;Park, Yeji;Lee, Jae Hun;Patel, Rajkumar
    • Membrane Journal
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    • v.29 no.6
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    • pp.299-307
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    • 2019
  • Photocatalysis is an environment friendly technique for degrading organic dyes in water. Tungsten oxide is becoming an active area of research in photocatalysis nanomaterials for having a smaller bandgap than the previously favored titanium dioxide. Synthesis of hierarchical structures, doping platinum (Pt), coupling with nanocomposites or other semiconductors are investigated as valid methods of improving the photocatalytic degradation efficiency. These impact the reaction by creating a redshift in the wavelength of light used, effecting charge transfer, and the formation/recombination of electron-hole pairs. Each of the methods mentioned above are investigated in terms of synthesis and photocatalytic efficiency, with the simplest being modification on the morphology of tungsten oxide, since it does not need synthesis of other materials, and the most efficient in photocatalytic degradation being complex coupling of metal oxides and carbon composites. The photocatalysis technology can be incorporated with water purification membrane by modularization process and applied to advanced water treatment system.

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

  • Lee, Jin Wo;Kim, Hyoung Sup;Woo, Hyo Seop
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.3
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    • pp.79-91
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    • 1993
  • An analysis of flow duration characteristics of the five major rivers in Korea was conducted with extensive river flow data available. The analysis reveals that, for most river stage-gauging stations at the rivers investigated in this study, the flow duration characteristics have changed drastically at some stations after major dammings in the river basins. Streamflow variability. which is newly defined in this study as the ratio of the 2.5 percents (or 10 day) duration discharge over the 97.5 percents (or 355 day) duration one, was also reduced by the dammings. The result of the study shows that the Han and the Yeongsan rivers have relatively small flow variation, while the Seomjin and the Keum rivers have relatively large now variation, which implies that the latter two river basins need new water resources development.

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

  • Lee, Jae-Hoon;Kim, Song-Ho;Yang, Wo-Jong;Kang, Eun-Hee;Chang, Hwa-Seok;Chung, Dai-Jung;Kim, Hwi-Yool
    • Journal of Veterinary Clinics
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    • v.27 no.3
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    • pp.295-298
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    • 2010
  • A five-year-old, castrated male, Pung-san dog was referred to Konkuk University Veterinary Teaching Hospital with trauma and persistent hemorrhage in the inguinal region. The dog had a history of being wounded by a wild boar at 5 days prior to presentation. Rupture of the membranous urethra and urethrocutaneous fistula were demonstrated by the retrograde positive contrast urethrography. A urinary catheter was placed to identify the urethra and urethrocutaneous fistula. The necrotic tissues and damaged tissues by urine leakage around urethrocutaneous fistula were debrided. An urethral anastomosis over an indwelling catheter was performed. The dog maintained normal urination without other complications including dysuria and hematouria at the follow-up evaluation after 1 month postoperatively. A retrograde urethrogram repeated at 2 months after surgery showed no urethral stricture.

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

  • Ju, Jin-Wo
    • The Journal of the Korean Society for Microbiology
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    • v.22 no.4
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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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Reaction Characteristics of Thermochemical Methane Reforming on Ferrite-Based Metal Oxide Mediums (페라이트계 금속 산화물 매체 상에서 열화학 메탄 개질 반응 특성)

  • Cha, Kwang-Seo;Lee, Dong-Hee;Jo, Won-Jun;Lee, Young-Seak;Kim, Young-Ho
    • Transactions of the Korean hydrogen and new energy society
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    • v.18 no.2
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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.

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

  • Lee, Eui-Ju;Jung, Yong-Jae;Kwak, Chang-Kyu;Hwang, Min-Woo;Yoo, Jung-Hee;Ko, Wo-Suk;Kim, Kyung-Soo;Koh, Byung-Hee
    • Journal of Sasang Constitutional Medicine
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    • v.19 no.2
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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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Effects of Microneedle Therapy System(MTS) and Hwangryeonhaedoktang Pharmacopuncture Solution on Hair Growth in an Alopecia Model of C57BL/6N Mouse (C57BL/6N 마우스 탈모모델에서 미세다륜침(MTS)과 황련해독탕 약침액 도포가 모발성장에 미치는 영향)

  • Kang, Na-Ru;Yoon, Hwa-Jung;Ko, Wo-Shin
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.29 no.1
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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.

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

  • Kim, Yong-Chin;Jeong, Dong-Myong
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.38 no.3
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    • pp.47-54
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    • 2001
  • This study is to analyze the impedance response in human body by acoustic stimulation on acupoints and contrast parte; for objectification of the meridian substance. It is to verify meridian pathway and channel theory or bio-energy in body. This paper proposes to make an hypothesis about the underground water theory. The meridian has not tube or pipe line type channel but bio-energy flow along the channel similar to flowing pattern of underground water in body. It was analyzed the current characteristic or impedance response after acoustic stimulation by sound wave of 5 specific tones. The response characteristics of current stimulation are measured by the average current magnitude and variation ratio or meridian. The current variation ratio or Live Meridian(gung) 33.2%, Heart Meridian(sang) 30.7% Kidney Meridian (gak) 33.1%, Spleen Meridian(chi) 33.9%, Lung Meridian (wo) 30.7% are to be compared to contrast parts (non-acupoint and meridian). In experimental results, meridian is discrimination to non-meridian, and 5 vital meridians have a reciprocal relationship with sound wave of 5 specific tones.

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