• 제목/요약/키워드: Pressure effects

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The Effects of Vertical Laryngeal Movements on the Vocal Folds (후두 수직운동이 성대에 미치는 영향)

  • Hong, Ki-Hwan;Kim, Hyun-Ki
    • Speech Sciences
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    • v.1
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    • pp.261-274
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    • 1997
  • In spite of the presumed importance of the strap muscles on laryngeal valving and speech production, there is little research concerning the physiological role and the functional differences among the strap muscles. Generally, the strap muscles have been shown to cause a decrease in the fundamental frequency(Fo) of phonation during contraction. In this study, an in vivo canine laryngeal model was used to show the effects of strap muscles on the laryngeal function by measuring the Fo, subglottal pressure, vocal intensity, vocal fold length, cricothyroid distance, and vertical laryngeal movement. Results demonstrated that the contraction of sternohyoid and sternothyroid muscles corresponded to a rise in subglottal pressure, shortened cricothyroid distance, lengthened vocal fold, and raised Fo and vocal intensity. The thyrohyoid muscle corresponded to lowered subglottal pressure, widened cricothyroid distance, shortened vocal fold, and lowered Fo and vocal intensity. It was postulated that the mechanism of altering Fa and other variables after stimulation of the strap muscles is due to the effects of laryngotracheal pulling, upward or downward, and laryngotracheal forward bending, by the external forces during strap muscle contraction.

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Studies on Hypotensive Mechanism of Ginseng Components (인삼성분(人蔘成分)의 혈압강하기전(血壓降下機轉)에 관한 연구(硏究))

  • Kim, Nak-Doo;Kim, In-Chull
    • Korean Journal of Pharmacognosy
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    • v.9 no.1
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    • pp.41-47
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    • 1978
  • Total saponins and ether extracts of red and white ginseng were obtained and their effects on blood pressure in cat and their histamine liberating activities in rabbits were measured. 1) Ether extract of red ginseng showed a transient hypotensive effect and subsequently showed a remarkable and persistent hypotensive effect, whereas other three fractions, such as saponin fractions of red and white ginseng and ether extract of white ginseng showed only a initial transient hypotensive effects. 2) Histamine levels liberated into blood after administration of each fractions measured by the bioassay with guinea pig ileum. Ether extract of red ginseng immediately increased histamine contents in plasma but the histamine levels decreased to normal level within 10min in spite of decreased blood pressure was sustained. Although white ginseng saponin lowered blood pressure immediately when it is administered, histamine release was observed after 10min. The results suggest that hypotensive effects of ginseng seems to have no correlation with the histamine liberating activity. Ginseng appears to show hypotensive effect via some other mechanisms.

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Computational analysis of compressibility effects on cavity dynamics in high-speed water-entry

  • Chen, Chen;Sun, Tiezhi;Wei, Yingjie;Wang, Cong
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.495-509
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    • 2019
  • The objective of this study is to analyze the compressibility effects of multiphase cavitating flow during the water-entry process. For this purpose, the water-entry of a projectile at transonic speed is investigated computationally. A temperature-adjusted Tait equation is used to describe the compressibility effects in water, and air and vapor are treated as ideal gases. First, the computational methodology is validated by comparing the simulation results with the experimental measurements of drag coefficient and the theoretical results of cavity shape. Second, based on the computational methodology, the hydrodynamic characteristics of flow are investigated. After analyzing the cavitating flow in compressible and incompressible fluids, the characteristics under compressible conditions are focused upon. The results show that the compressibility effects play a significant role in the development of cavitation and the pressure inside the cavity. More specifically, the drag coefficient and cavity size tend to be larger in the compressible case than those in the incompressible case. Furthermore, the influence of entry velocities on the hydrodynamic characteristics is investigated to provide an insight into the compressibility effects on cavitating flow. The results show that the drag coefficient and the impact pressure vary with the entry velocity, and the prediction formulas for drag coefficient and impact pressure are established respectively in the present study.

Tne Measurements of internal Dynamic Pressure for Development of a High Performance Oil hydraulic Vane Pump(I) (고성능 유압 베인펌프 개발을 위한 내부 변동압력 측정 (I))

  • 정재연;정석훈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.16 no.2
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    • pp.191-199
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    • 1992
  • This paper presents in experimental study of the dynamic internal pressure within an oil hydraulic vane pump. The measurements of the dynamic internal pressures near the vane of a pressure balance type of an oil hydraulic vane pump with intravanes has been made to provide the essential information for the study of the pump dynamics and control, the pump design and the analysis of tribological problems in the sliding components. The influences of the discharge pressure and rotating speed of the vane on the dynamic pressure in four chambers surrounding a vane have been investigated. The results indicate that the surge pressures of the chambers at the instant moment of discharge and closure are affected by the rotating speed. The pressure in the intravane chamber maintains almost constant values, which remarkably effects the pulsating discharge pressure.

Modeling of Engine Intake Pressure for Predicting Braking Performance Affected by Altitude (고도에 따른 제동 성능 예측을 위한 엔진 흡기압 모델링)

  • An, Kwangman;Lee, Jisuk;Park, Jinil;Lee, Jonghwa
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.3
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    • pp.228-233
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    • 2014
  • Reduction of the atmospheric pressure in high altitude affects brake booster system which was operated by the difference between the intake pressure and the atmospheric pressure. So, braking system can not stably perform due to decrease of brake boost pressure. In this study, effects of altitude change on engine intake pressure was analyzed by prediction model of engine intake pressure which was studied previously. And engine intake pressure was simulated by simulation model in various driving conditions and environmental conditions.

Effects of San-Yin-Jio(SP-6) pressure on duration of delivery time and quantity of blood loss for primipara (삼음교(三陰交) 자극이 초산부(初産婦)의 분만(分娩) 소요시간과 실혈량(失血量)에 미치는 효과(效果))

  • Kim, Woo-hwan;Kim, Won-ill;Lee, Kyung-hee;Youn, Hyoun-min
    • Journal of Acupuncture Research
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    • v.20 no.5
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    • pp.82-92
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    • 2003
  • Objective: To appreciate the effect of San-Yin-Jiao(SP-6) pressure on duratof delivery time and quantity of blood loss in order to verify the possibility of application to clinic of San-Yin-Jiao pressure. Methods: The design of this study is nonequivalent control group non- synchronized design. The subjects are 39 persons who are made up of SP-6 pressure applied(experimental) group 20 persons and to control group 19 persons. Collected data were analyzed as frequency, percentage, t-test, $x^2-test$ using SPSS 10.0 WIN Program. Conclusions: San-Yin-Jiao(SP-6) pressure not only make short duration of delivery time, but also decline quantity of blood loss in effect. 1. It could be necessary that the study of the effects of San-Yin-Jio(SP-6) pressure on duration of delivery time and quantity of blood loss for primipara be done repeatedly. 2. It could be necessary to increase this sort of study through free random experimental design in order to generalize this experimental result.

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Effects of Semen Persicae Pharmacopuncture on Blood Pressure of Outpatients (도인약침(桃仁藥鍼)이 외래환자 혈압에 미치는 임상적 고찰)

  • Kim, Cheol-Hong;Youn, Hyoun-Min;Song, Choon-Ho;Ahn, Chang-Beohm;Jang, Kyung-Jeon
    • Journal of Acupuncture Research
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    • v.26 no.6
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    • pp.85-90
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    • 2009
  • Objectives : In order to study effects of drop of blood pressure by Semen Persicae Pharmacupuncture a clinical study was investigated. Methods : Semen Persicae Pharmacupuncture at Sp9 and Sp10 on 52 hypertension patients who are treating on Dong-Eui Oriental Medical Hospital. Results : 1. After one times Semen Persicae Pharmacupuncture at Sp9 and Sp10, the systolic blood pressure were droped. 2. After two times Semen Persicae Pharmacupuncture at Sp9 and Sp10, the diastolic blood pressure were droped significantly. 3. Headache, Dizziness that the subjective symptoms were droped after two times Semen Persicae Pharmacupuncture at Sp9 and Sp10. Conclusions : Continous Semen Persicae Pharmacupuncture at Sp9 and Sp10 implies drop of blood pressure and improvement of subjective symptoms.

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Investigation of Droplet Vaporizatio Phenomena in High Pressure Environments (고압에서의 액적의 증발현상에 관한 연구)

  • Lee, Hyun-Chang;Baek, Seung-Wook
    • Journal of the Korean Society of Combustion
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    • v.13 no.3
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    • pp.17-23
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    • 2008
  • The spray combustion and spray cooling depends on droplet evaporation. So, evaporation model for spray has been requested and lots of investigation has been done and various reliable models have been developed also for last few decades. In the present study, One dimensional quasi-steady spherically symmetric droplet evaporation model for micro-gravity is developed. The gas phase was assumed as steady state and the thermophysical properties are calculated as a function of temperature, pressure and composition and the properties used in the model was validated by NIST web data and overall evaporation history results was compared with experimental results by Nomura and Qasim and gave satisfactory agreements. Through this model, diverse phenomenon was investigated, especially regarding the effects of ambient pressure and temperature. The effects of pressure for the droplet evaporation time were studied. The high pressure increased the droplet surface temperature and made effect on the evaporation time depend on atmospheric temperature. The role of the ambient temperature was investigated and explained. The basic investigation for the evaporation process according to variation of droplet diameter and surface temperature were also investigated and the well-known phenomena, like D-square-law, were reported, too.

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Effects of Huanglianjiedu-tang Granules for Transient Elevated Blood Pressure: A Case Series (일시적 혈압상승에 대한 황련해독탕 과립제의 효과 : 증례 보고)

  • Jeong, Sin-yeong;Jo, Hee-geun;Kim, Eun-mi;Jeong, Jun-su;Im, Hyeok-bin
    • The Journal of Internal Korean Medicine
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    • v.40 no.6
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    • pp.1288-1293
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    • 2019
  • Objective: This study reports the effects of Huanglianjiedu-tang (黃連解毒湯) granules as a treatment for transient hypertension. Methods: Four patients experienced sudden blood pressure elevation without a history of hypertension treatment. There was no specific history of disease, as confirmed by laboratory examination and image diagnosis. The patients were treated with Huanglianjiedu-tang (黃連解毒湯) granules and their blood pressure analyzed over time. Results: After treatment with Huanglianjiedu-tang granules, the mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) of all patients decreased significantly. Conclusions: The study suggests that Huanglianjiedu-tang (黃連解毒湯) granules could be a primary treatment for hypertension. A well-designed study should be conducted for further evaluation of the effectiveness of the treatment.

Effects of Casein Hydrolysate on the Systolic Blood Pressure and Serum Lipid Profiles in Spontaneously Hypertensive Rats

  • Do, Jeong-Ryong;Back, Su-Yeon;Lim, Sang-Dong;Kim, Hyun-Ku;Sung, Ki-Seung;Han, Chan-Kyu
    • Food Science of Animal Resources
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    • v.30 no.4
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    • pp.545-550
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    • 2010
  • The effects of casein hydrolysate on blood pressure (BP) and serum lipid profiles were investigated in spontaneously hypertensive rats (SHR). Twenty-four 6-wk old male SHRs were assigned to 3 groups in a completely randomized design. Experimental groups were as follow: control, market milk group (MLG) and casein hydrolysate group (CHG). Reference blood pressure (RBP) showed average $198.94{\pm}1.46mmHg$. Blood pressure (BP) of CHG reduced 24 mmHg after 2 wk of treatment, but these increased after 3 wk. BP of CHG was significantly lower than BP of Control in experimental time (p<0.05). Serum lipid profiles were not differ significantly among groups (p<0.05). These data suggest that casein hydrolysate may beneficially improvement of blood pressure level in SHR.