• 제목/요약/키워드: Capillary Wave

검색결과 55건 처리시간 0.026초

쓴 맛 물질의 표면 장력과 쓴 맛의 상관 관계 (Research on the Correlation of the Surface Tension and Sensory Quality of Bitter Substances)

  • 김정미
    • 한국식품과학회지
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    • 제27권5호
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    • pp.646-651
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    • 1995
  • 순수 물질 수용액의 표면장력치 측정과 JND를 통한 맛 관능 분석에 의해 쓴 맛 물질의 표면 장력과 쓴 맛 간의 상관성을 연구한 결과, 모든 쓴 맛 물질 수용액은 용액의 농도가 증가함에 따라 표면 장력이 감소되어 Szyszkowski 방정식과 Techplot program으로 표면 장력 감소 곡선을 수학적으로 나타낼 수 있었고 또한 관능 분석에 의한 JND 맛 곡선도 같은 방법으로 묘사하여 상호 비교됨을 알 수 있었다. 또한 측정된 모든 쓴 맛 성분들에 대하여 표면 장력 곡선으로부터 상수 a, b 값을, 맛 곡선으로부터 상수 A, B 값을 계산하여 쓴 맛 인지역치 $log\;C_{1}$과 평형 상수 b 값 간의 음의 상관 관계식을 구하였다. 또한 쓴 맛 인지역치 농도 $log\;C_{1}$과 기계적인 측정치로 산출된 parameter들의 상관성을 PV-wave 프로그램을 이용해서 3차원적으로 비교한 $log\;C_{1}$/a/b와 $log\;C_{1}$/A/B간의 상관관계는 주목할 만하며 이는 용액과 기체간의 계면 system에서의 계면 흡착 모델이 구강 내에서의 조직과 용액 간의 관능적 모델에도 적용됨을 나타내며 나아가 표면장력치의 측정이, 신경자극 전달 측정을 위한 Beidler의 이론과 Szyszkowski 방정식을 이용하여 쓴 맛을 기계적으로 측정하는 독립적인 방법을 개발하는데 응용될 수 있음을 시사해 준다.

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전진하며 동요하는 2차원 특이점에 의하여 발생되는 자유표면파에 미치는 표면장력의 영향 (Surface-Tension Effects on the Flow Caused by a Two-Dimensional Pulsating Source Moving with a Constant Speed beneath the Free Surface)

  • 최항순;최재식
    • 대한조선학회지
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    • 제27권1호
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    • pp.57-62
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    • 1990
  • 본 논문에서는 표면장력 효과를 포함한 선형포텐셜이론을 이용하여 전진하며 동요하는 2차원 소오스에 의하여 발생되는 자유표면파를 해석하였다. 속도를 U, 진동수를 $\omega$ 그리고 중력가속도를 g라 할 때, ${\tau}=U{\omega}/g$로 정의된 무차원 진동수가 임계치 1/4보다 작을 때에는 6개의 파성분이 나타남을 보였다. 이 중에서 특히 2개의 파성분은 표면장력의 영향을 지배적으로 받아 소오스 앞면에 발생하는 데, 그중 하나는 전진속도 방향으로 다른 하나는 반대방향으로 매우 느리게 전파한다. 동요수가 작을 경우에는 표면장력의 영향이 약해지며 임계치 1/4보다 조금 큰 진동수에서 공진이 발생한다. 그러나 동요수가 클 때에는 (${\upsilon}={\omega}^2/g>20$) 표면장력효과가 크게 작용하여 발생파의 진폭이 감소하며 분산되어 임계치에서의 공진현상이 사라진다. 한편 전진속도가 표면장력파의 최소위상속도인 0.232m/sec일 때어는 해가 존재하지 않는다.

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저출력 레이저 조사가 성견의 실험적 치주질환 치유에 미치는 영향에 관한 조직병리학적 연구 (THE HEALING EFFECTS OF LOW POWER DENSITY LASER TO THE EXPERIMENTAL PERIODONTITIS;HISTOPATHOLOGIC STUDY)

  • 김동운;이재현;정진형
    • Journal of Periodontal and Implant Science
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    • 제23권1호
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    • pp.16-26
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    • 1993
  • In order to investigate the healing effect on inflammation and bone regeneration of low power density laser radiation in dogs, experimental periodontitis was made in dog mandibular 3rd, 4th premolars. All teeth were classified with four groups of two experimental group and control groups. The second group were irradiated on periodontitis site and the first group were control. The fourth group were irradiated on periodontitis site flap operation and the third group were flap control. Experimental groups were irradiated with GaAs low power density laser of pulse wave and continuous wave of 904nm every day by five days respectively and then control group and experimental groups were evaluated by histo-pathological study. The results were as follows : 1. Experimental periodontits site of dog were irradiated with GaAs low power laser results in reducing of pseudoepitheliomatous proliferation and inflammation at light microscope. 2. After irradiation with low power density laser, experimental groups were revealed that PDL forming activity were increased and newly formed collagen deposition were observed. 3. Low power density lsaer irradiation on experimental periodontits site after flap operation showed that decreasing of inflammation, reducing of osteoclast activity. Capillary proliferation, reduction of pseudoepitheliomatous proliferation. 4. After irradiation with low power density laser on flap experimental site, experimental groups were revealed that newly formed collagen in periodontal ligament and alveolar bone were detected on MT staining.

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광로차 보상회로가 부착된 마이켈슨 간섭계에 의한 탄성파 신호검출 (Detection of Elastic Waves Using Stabilized Michelson Interferometer)

  • 김영환;소철호;권오양
    • 비파괴검사학회지
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    • 제13권4호
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    • pp.32-41
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    • 1994
  • 탄성파에 의한 미소 동적 변위를 측정하기 위하여 안정화 회로가 부착된 Michelson 간섭계를 개발하였다. 안정화 회로는 외부 진동신호에 따른 광로차의 교란을 보상하기 위하여 압전구동기가 부착된 기준거울을 사용하였다. 안정화 회로를 사용함으로써, 간섭계는 외부 진동신호의 영향을 줄일 수 있었고, 항상 직각조건(quadrature condition)을 만족하여 광검출기의 출력신호가 최대의 감도와 선형성을 유지할 수 있었다. 검출가능한 최소 변위는 10MHz 대역에서 0.3nm 이었다. 개발된 간섭계를 사용하여 유리관 파괴 및 강철구 충격에 의한 진앙점에서의 변위를 검출하여 이론적으로 계산된 값과 비교하였다.

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수직하방 분사된 주의 비선형 거동에 관한 연구 (A Study on the Nonlinear Motion of a Vertical Liquid Jet)

  • 석지권;정환문;문수연;이충원
    • 대한기계학회논문집B
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    • 제26권1호
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    • pp.45-54
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    • 2002
  • The breakup phenomena of a vertical laminar jet issuing from capillary tubes in a quiescent ambient air are investigated using a forced vibration analysis of the surface wave. Using a linear approach to the transient jet velocity, an approximate solution fur the longitudinal motion of a vertical liquid jet is theoretically derived, thus performing an instability analysis by a vibration method. The damping term of this equation is nonlinear as it depends on dimensionless parameters, a Weber number, and an Ohnesorge number. The instability condition is determined based on whether the coefficient of the damping term is less than zero or not. Uniform drop formation is dependent on the vibration frequency fur the forced vibration case.

고양이 위(胃)의 수축 및 전기활동에 대한 에탄올과 칼슘의 관계 (Relation of Ethanol and Calcium to Contractile and Electrical Activity of Cat Stomach)

  • 김명석;심상수;윤신희;한상준;김정진;최현
    • The Korean Journal of Physiology
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    • 제21권2호
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    • pp.259-272
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    • 1987
  • This was study carried out to investigate the effect of calcium on spontaneous contraction and electrical activity induced by ethanol in gastric smooth muscle. After peeling off the mucous membrane from the isolated whole stomach of 102 cats, two kinds of small muscle preparations $(2.0{\times}0.2\;cm)$, one longitudinal and the other circular, were excised from the fundus, the corpus and the antrum portion of each whole stomach specimen. The isometric contraction of the small muscle preparation was measured in a cylinder-shaped chamber filled with Krebs-Ringer-dextrose solution (pH 7.4, temperature $36{\pm}0.5^{\circ}C$) bubbling with 5% $CO_2$ in $O_2$. A large muscle preparation $(5.0{\times}1.2\;cm)$ was excised from the anterior wall of the corpus-antrum portion of the same specimen in 72 of 102 cats. The gastric electrical activity (slow wave and spike potential) was monopolarly recorded by four capillary electrodes (Ag-AgCl), of which two were placed on the corpus and two on the antrum, in a muscle chamber filled with the same solution as described above. Changes in the amplitude of the contraction, frequency of the gastric slow wave and the production of the spike potential were observed after adding ethanol and/or under the treatments with verapamil, $CaCl_2$ and Ca-free Krebs-Ringer-dextrose solution. The results were as follows: 1) After adding ethanol, the spontaneous phasic contraction of the corpus was reduced dose-dependently (0.125-2.0%), which was totally abolished by higher concentrations (2.0-8.0%) of ethanol. 2) The corporal phasic contraction was also completely abolished by verapamil $(3{\times}10^{-5}\;M)$ or Ca-free Krebs-Ringer-dextrose solution. The contraction was increased by $CaCl_2\;(1.8{\times}10^{-3}\;M)$, but the inhibitory effect of ethanol on the contraction persisted even under the treatment with $CaCl_2$. 3) At higher concentrations, ethanol caused tonic contraction of both preparations from the fundus, the corpus and the antrum in a dose-dependent manner. The tonic contraction of the fundus produced by ethanol was not influenced by $CaCl_2$ or verapamil, whereas the tonic contraction was not produced by ethanol in tile Ca-free solution. 4) Frequency of gastric slow wave was decreased dose-dependently by the addition of ethanol (0.25-1.0%), and tile slow wave was not produced by higher concentration of ethanol (2.0%). 5) The frequency of slow wave was significantly reduced by verapamil only and the inhibitory influence of ethanol on the slow wave frequency was reinforced by verapamil. 6) The treatment of $CaCl_2$ increased significantly the slow wave frequency, and attenuated the inhibitory effect of ethanol on the frequency. It is therefore suggested that ethanol regulates the phasic contraction and the production of slow wave by interfering with the transport of calcium in the stomach muscle of the cat.

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미병 정량 지표에 관한 중국의 임상연구 동향 분석 - China National Knowledge Infrastructure를 중심으로 - (Analysis of Clinical Research Trends on Quantitative Indicators of Mibyeong in China - Using China National Knowledge Infrastructure -)

  • 여민경;이영섭
    • 대한예방한의학회지
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    • 제22권1호
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    • pp.15-28
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    • 2018
  • Objectives : The purpose of this study was to analyze the trend of clinical research on quantitative indicators of Mibyeong in traditional chinese medicine(TCM). Method : The journal search was performed using china national knowledge infrastructure(CNKI) database. Our inclusion criteria were as following: TCM clinical researches for quantitative indicators of Mibyeong. Exclusion criteria were as following: non-TCM clinical researches, used intervention methods. Results : Eleven clinical researches were analyzed in this study. Four of these researches classify the Mibyeong as a type of pattern identification(PI) and studied the characteristics of the PI quantitative indicators. Mibyeong diagnosis was done through guidelines and questionnaires, each was used at a similar rate. Quantitative indicators mentioned in the selected researches were blood indices, nailfold capillary, complexion, color of tongue substance and coating, pulse wave diagrams and heart rate variability. Among them, seven researches related to blood indices were the most. Blood indicators include whole-blood viscosity, plasma viscosity, fibrinogen, packed cell volume(Hct), triglycerides, total cholesterol, HDL-C, LDL-C, glucose, BUN/CREA, luteinzing hormone, estradiol, follicle stimulating hormone, IgA, IgG, etc. Conclusions : Based on this results, in combination with western medicine, it seems necessary to try to interpret the Mibyeong in more various ways. Even if the same Mibyeong, it is necessary to identify the index which changes according to the PI or chief complaint, and to set the Mibyeong standard corresponding thereto.

Remote Sensing of Surface Films as a Tool for the Study of Oceanic Dynamic Processes

  • Mitnik, Leonid;Dubina, Vyacheslav;Konstantinov, Oleg;Fischenko, Vitaly;Darkin, Denis
    • Ocean and Polar Research
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    • 제31권1호
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    • pp.111-119
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    • 2009
  • Biogenic surface films, which are often present in coastal areas, may enhance the signatures of hydrodynamic processes in microwave, optical, and infrared imagery. We analyzed ERS-1/2 Synthetic Aperture Radar (SAR) and Envisat Advanced Synthetic Aperture Radar (ASAR) images taken over the Japan/East Sea (JES). We focused on the appearance of the contrast SAR signatures, particularly the dark features of different scales caused by various oceanic and atmospheric phenomena. Spiral eddies of different scales were detected through surface film patterns both near the coast and in the open regions of the JES in warm and cold seasons. During field experiments carried out at the Pacific Oceanological Institute (POI) Marine Station 'Cape Shults' in Peter the Great Bay, the sea surface roughness characteristics were measured during the day and night using a developed polarization spectrophotometer and various digital cameras and systems of floats. The velocity of natural and artificial slicks was estimated using video and ADCP time series of tracers deployed on the sea surface. The slopes of gravity-capillary wave power spectra varied between .4 and .5. Surface currents in the natural and artificial slicks increased with the distance from the coast, varying between 4 and 40 cm/s. The contrast of biogenic and anthropogenic slicks detected on vertical and horizontal polarization images against the background varied over a wide range. SAR images and ancillary satellite and field data were processed and analyzed using specialized GIS for marine coastal areas.

광-유체링공진기(OFRR) 바이오센서에 관한 공진이동과 양호도의 시뮬레이션 (Simulation of Resonance Shift and Quality Factor for Opto-fluidic Ring Resonator (OFRR) Biosensors)

  • 조한근;한진우;양길모
    • Journal of Biosystems Engineering
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    • 제36권1호
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    • pp.23-32
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    • 2011
  • In this work, the finite element method was used to investigate the shifts of resonance frequencies and quality factor of whispering-gallery-mode (WGM) for an opto-fluidic ring resonator (OFRR) biosensor. To describe the near-field radiation transfer, the time-domain Maxwell's equations were employed and solved by using the in-plane TE wave application mode of the COMSOL Multiphysics with RF module. The OFRR biosensor model under current study includes a glass capillary with a diameter of 100 mm and wall thickness of 3.0 mm. The resonance energy spectrum curves in the wavelength range from 1545 nm to 1560 nm were examined under different biosensing conditions. We mainly studied the sensitivity of resonance shifts affected by changes in the effective thickness of the sensor resonator ring with a 3.0 mm thick wall, as well as changes in the refractive index (RI) of the medium inside ring resonators with both 2.5 mm and 3.0 mm thick walls. In the bulk RI detection, a sensitivity of 23.1 nm/refractive index units (RIU) is achieved for a 2.5 mm thick ring. In small molecule detection, a sensitivity of 26.4 pm/nm is achieved with a maximum Q-factor of $6.3{\times}10^3$. These results compare favorably with those obtained by other researchers.

Anti-ischemic Effects of Nimesulide, a Cyclooxygenase-2 Inhibitor on the Ischemic Model of Rabbit Induced by Isoproterenol

  • Saeed, Sheikh Arshad;Ahmed, Sagheer
    • Archives of Pharmacal Research
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    • 제29권11호
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    • pp.977-983
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    • 2006
  • The objective was to devise an animal model of myocardial infarction (MI) against which cardioprotective drugs might be tested. We describe the effects of nimesulide, a COX experience with development and validation of such a model. The rabbit was chosen in preference to rodents because its heart and cardiac circulation more closely resemble those of human. Thus, the cardiovascular system of anaesthetized male rabbits, 1 to 1.5 kg (n=11), was stressed by a single bolus intravenous injection of isoprenaline (ISP), 65 mg/kg. The effects of the injection were followed for sixteen days and were evaluated in four ways: 1) measurements of creatinine kinase isozyme and troponin-I (TPI) in serum 2) Electrocardiographic (ECG) changes (ST elevation and Q wave development) 3) Cardiac histopathology observed in tissue sections of the isolated of the heart. The histopathological analysis showed that rabbit heart on 2nd day after ISP injection showed changes of coagulation necrosis. Day 4 total coagulation with the loss of nuclear and striation associated with heavy interstitial infiltrate of neutrophils was found. Day 8 after infarction showed collagen deposition with capillary channels in between the remaining islands of myocytes in the infarcted area. On the 16th day scarring was complete. Coronary perfusion rates (CPR) and heart rate (HR) of the infarcted and nimesulide (a COX-2 inhibitor) treated rabbits displayed significant improvement (n=11) on each corresponding day after infarction as compared to the infarcted and saline treated rabbits (P<0.05). All four indices revealed similarities with effects commonly associated with MI in humans.