• 제목/요약/키워드: Penetration rates

검색결과 211건 처리시간 0.026초

에멀젼 연료를 이용한 디젤엔진의 분무 및 배기특성 연구 (Spray Charaeteristics and Exhaust Emission Tests far a Diesel Engine Using Emulsified Fuels)

  • 서희준;오승묵;허환일
    • 한국자동차공학회논문집
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    • 제10권4호
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    • pp.60-68
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    • 2002
  • Experiments have been conducted to investigate the effects of emulsified fuels on the spray characteristics and exhaust emissions in a diesel engine. Four different fuels were examined : diesel, emulsified fuels with water contents which were varied with 13, 15, and l7wt%. Characteristics of fuel spray were measured by an optical method, PLLIF(planar liquid laser induced fluorescence). Compared to diesel fuel, emulsified fuels which had relatively high kinematic viscosity showed smaller spray angle and longer spray tip penetration. The qualitative droplet distributions of emulsified fuels showed worse atomization process than that of diesel fuel. As the water contents were increased, PM and NOx could be reduced simultaneously. It was specially noted that the emulsified fuel with l7wt% water content was found to be the best in reducing rates, NOx 30% and PM 40%.

Effects of $\beta$-Mercaptoethanol on Lipid Peroxidation and Fertilization Ability In Vitro by Xanthine-Xanthine Oxidase System in Pig

  • Sa S.J.;H.T. Cheong;B.K. Yang;Kim, C.I.;Park, C.K.
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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    • pp.74-74
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    • 2002
  • This study was undertaken to evaluate the effects of β-mercaptoethanol on lipid peroxidation and fertilization ability in vitro by xanthine (X)-xanthine oxidase (XO) system in boar spermatozoa frozen-thawed. When spermatozoa were inseminated in medium with X and/or XO, the penetration rates in all conditions were higher in medium with that than without β-mercaptoethanol. However, significant differences were not observed between medium with and without β-mercaptoethanol. The lipid peroxidation of sperm was evaluated on the basis of malondialdehyde (MDA) production. (omitted)

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극초고압영역에서의 디젤연료의 자유분무특성에 관한 연구 (A Study on Spray Characteristics Analysis of Free Spray of Diesel Fuel with Ultra High Pressure)

  • 정대용;이종태;홍기배
    • 한국분무공학회지
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    • 제7권4호
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    • pp.16-22
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    • 2002
  • The characteristics of free spray with ultra injection pressure was analyzed to clear the limit pressure of diesel engine. To obtain final goal, ultra high pressure injection equipment was developed, spray patterns were visualized under various ultra injection pressures. Spray penetration and spray width, volume and entrained air mass were increased with the increase of injection pressure. Sauter mean diameter and injection durstion wert decreased. But over 3,000bar of ultra injection pressure region the rates of increase show almost similar and finally the reversed tendencies at 4,140bar.

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분류에 의한 SLURRY 마멸 (Slurry Wear Test on the Liquid Jet)

  • 우창기;조견식
    • 한국공작기계학회논문집
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    • 제11권5호
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    • pp.88-92
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    • 2002
  • This research is about slurry wear of SM45C and SUS304, which using standard sand and KUM river sand. The results are as follows ; 1. Mass loss rates of both standard sand and KUM river sand were linearly increased as increasement of time and velocity. 2. The average diameter of sand from relatively, less wear rate and portion of larger particles. 3. Wear resistance was linear with time and velocity of liquid jet regardless of type of sand. Also, it was able to evaluate with the formula, $HV^2$/E calibrated with n, the velocity index. 4. The wear surface in liquid jet experiment was smooth. The maximum wear depth was observed at the location 2~4mm apart from the center in the condition of $90^{\circ}$ of collision angle 6mm of nozzle diameter, and 20mm of collision distance. The sectional shape in radial appeared as 'W'shape.

금강 토사에 의한 SLURRY 마멸 (Slurry Wear of Sand from the Kum River)

  • 우창기;조견식;김대업;강동명;이하성
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.798-801
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    • 2001
  • This research is about slurry wear of SM45C and SUS304, which using standard sand and KUM river sand. The results are as follows ; 1. Mass loss rates of both standard sand and KUM river sand were linearly increased as increasement of time and velocity. 2. The average diameter of sand from relatively, less wear rate and portion of larger particles. 3. Wear resistance was linear with time and velocity of liquid jet regardless of type of sand. Also it was able to evaluate with the formula, HV2/E calibrated with n, the velocity index. 4. The wear surface in liquid jet experiment was smooth. The maximum wear depth was observed at the location, 2~4mm apart from the center in the condition of 90$^{\circ}$of collision angle 6mm of nozzle diameter, and 20mm of collision distance. The sectional shape in radial appeared as 'W' shape.

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A Comparison of Wavelength Dependence for Laser-assisted Lipolysis Effect Using Monte Carlo Simulation

  • Youn, Jong-In
    • Journal of the Optical Society of Korea
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    • 제13권2호
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    • pp.267-271
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    • 2009
  • The aim of this study is to evaluate wavelength dependence for laser-assisted lipolysis using a mathematical simulation. In this study, a Monte Carlo simulation was performed to simulate light transport in fat and dermal tissue with 3 different laser wavelengths (${\lambda}\;=\;1064\;nm$, 1320 nm, and 1444 nm) that are currently used in clinic settings for laser-assisted lipolysis. The relative rates of heat generation versus penetration depth showed that the greatest amount of heat generation was seen in the tissues at ${\lambda}\;=\;1444\;nm$. This Monte Carlo simulation may help lend insight into the thermal events occurring inside the fat and dermal tissue during laser-assisted lipolysis.

철근콘크리트 구조물의 철근부식과 부식균열의 발생 예측 (Prediction of Steel Corrosion and Corrosion Cracking in Reinforced Concrete Structures)

  • 김호진;조호진;송하원;변근주
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.657-662
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    • 2003
  • In this study. a micro-corrosion model of steel in RC structure is established for micro-structure development in view to micro-mechanics and the model is composed of chloride penetration model and oxygen diffusion model to evaluate for corrosion rate and accumulated corrosion amounts. Also the model is composed of corrosion-cracking model for prediction of corrosion-cracking. The time and space dependent induced corrosion-cracking of RC structures including changes of corrosion rates and concentrations of chloride ion are simulated using the finite element analysis adopted the proposed model Then, results of the analysis are compared with test results for verification.

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가감팔물탕(加減八物湯)을 투여한 아토피 피부염 환자 104명의 경표피수분손실율 변화 (Changes in transepidermal water loss after medication of Gagampalmultang to 104 patients with atopic dermatitis)

  • 안상훈;이종훈
    • 대한한의학방제학회지
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    • 제11권1호
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    • pp.197-204
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    • 2003
  • The skin is a barrier between the living organism and its environment, and this barrier function resides in the stratum corneum. The main function of the stratum corneum is to serve as a barrier preventing the penetration of irritants and transepidermal water loss(TEWL). The rate of transepidermal water loss is a convenient parameter for expressing barrier function. Impaired barrier function was manifested by a greatly increased rate of transepidermal water loss. In atopic dermatitis the rate of transepidermal water lossis greatly increased transepidermal water loss. Medication of Gagampalmultang restored to normal the abnormally high rates of transepidermal water loss in the 104 patients with atopic dermatitis. It specifically plays an important role in regulating barrier function.

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고압 분사 디잴 인잭터의 노즐 형상이 분사 특성 및 분무 거동에 미치는 영향 (Effect of nozzle geometry on the injection characteristics and spray behavior)

  • 이창식;박성욱;전문수
    • 한국분무공학회지
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    • 제9권1호
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    • pp.1-7
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    • 2004
  • This paper describes the characteristics of injection rate and macroscopic behavior of fuel spray injected from common-rail type diesel injectors with different nozzle geometries. The injection rates according to the nozzle geometries were measured at different energizing duration of the injector solenoid and injection pressure by using the Bosch's injection rate meter based on the pressure variation in the tube. The spray behaviors injected from the different nozzles were visualized using the spray visualization system composed of an Ar-ion laser, an ICCD camera, and a synchronization system at various injection and ambient pressures. It is revealed that VCO nozzle has higher spray tip velocity at the early stage of injection duration and wider spray cone angle than the mini-sac nozzles. Also the spray cone angle is increased with the increase of nozzle diameter.

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불임여성중에 존재하는 투명대 자가항체의 측정과 이들 항체가 생쥐난자의 체외수정에 미치는 영향 (Detection of Autoantibodies to Zona Pellucida in Infertile Women and Their Effect on In Vitro Fertilizatin of Mouse Eggs)

  • 정형민;조인제;김종배;이훈택;정길생
    • 한국가축번식학회지
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    • 제15권3호
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    • pp.225-231
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    • 1991
  • These experiments were carried out ot detect autoantiboies to zona pellucida in sera from infertile women using indirect ELISA and IFA and to investigate their effect on in vitro fertilization of mouse ova. In inidirect ELISA test, 12 of 116(10.3%) serum samples form infertile women gave positive reaction whereas all of 16 samples from fertile women and men were negative. Furthermore, in indirect IFA test, 17 of 116 (14.7%) serum samples from infertile women gave positive fluorescence whereas all of control sera were negative fluorescence. The fertilization rates(15.9%) of mouse eggs treated with positive sera were significantly lower than those(51.9%+71.2%) autoantibodies to zonapellucida are responsible for infertility in unexplained infertile women, presumably by perventing sperm attachment and penetration.

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