• Title/Summary/Keyword: Throat Area

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Harm of Passive Smoking (간접 흡연의 유해성)

  • Lee, Dong-Uk
    • Journal of Korea Association of Health Promotion
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    • v.3 no.2
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    • pp.165-171
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    • 2005
  • Passive smoking is the involuntary inhalation of tobacco smoke by a person, especially a non-smoker, who occupies and area with smokers or a smoker. Passive smoking may cause eye and nose irritation, sore throat, headache, cough to everyone, and it is known that non-smokers have the same kinds of illness with smokers. Smoking rate among the adults aged over 20 in Korea is higher than that of the US or European conturies. Therefore we suppose that Koreans may be exposured to passive smoking than the people of other conturies. It is necessary that people have the knowledge on the heath problems caused by passive smoking and on prevention from the involuntary inhalation of tobacco smoke. I propose that the smokers should be informed the importance of smoking cessation.

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Analysis of the Characteristics of an Aerospike Pintle Nozzle in terms of Stroke and Operating Pressure

  • Kim, Jeongjin
    • Journal of Aerospace System Engineering
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    • v.14 no.4
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    • pp.1-9
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    • 2020
  • The characteristics of an aerospike pintle nozzle system with excellent altitude compensation were analyzed using cold air testing. It was confirmed that reducing the stroke of the aerospike nozzle is effective in increasing the thrust. However, the results of additional numerical analysis indicated that the discharge coefficient factor was significantly lower at the maximum stroke. The Vena contracta due to the cowl reduction angle decreased the effective nozzle throat area at the maximum stroke and hindered expansion. Complementing the cowl design may thus increase the efficiency of a solid-propellant rocket engine that uses the aerospike pintle nozzle system.

A Case of Mixed Cavernous, Capillary Hemangioma Arising from Supraglottis (성문 상부에 발생한 혼합형 혈관종)

  • Lee, Eun-Kyeung;Kwon, Seong-Keun
    • Korean Journal of Bronchoesophagology
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    • v.16 no.2
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    • pp.161-164
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    • 2010
  • Laryngeal hemangioma occurs mostly in infantile patients and infantile hemangiomas can be frequently seen in the subglottic area. So, respiratory distress is a main symptom in this entity. But adult hemangiomas are rare and can be seen in different locations such as in epiglottis, aryepiglottic fold, arytenoids and false and true vocal folds. Authors experienced a case of mixed hemangioma at the right aryepiglottic fold in a 42 years-old-man who was presented with snoring, throat foreign body sense for 3 months. So, we report this case with a review of the literature.

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S-N Fatigue Strength of Small Diameter Branch Welded Pipe with Variation of Welding Shapes and Welding Procedures (용접부의 형상과 공정변화에 따른 소구경 분기배관의 피로강도 특성평가)

  • 백종현;김우식
    • Journal of Welding and Joining
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    • v.22 no.3
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    • pp.50-55
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    • 2004
  • S-N fatigue tests were conducted to investigate the fatigue strength of small diameter socket and butt welded joints made of carbon steels. Experimental parameters were pipe diameter, throat depth, shape of socket welds and welding procedure. Filler metals used in SMAW and GTAW procedure were E9016-G with diameter of 4.0 m and ER70S-G with diameter of 2.4 m. API 5L Gr.B pipes were adopted as a small diameter branch pipes. All socket fittings were machined from ASTM A105 carbon steel. Tensile strength was not affected by the welding procedure. Fatigue strength in socket weld joints increased with increasing pipe diameter, area of weld metal and weld leg length of pipe side.

Patent Review on Drive Mechanism of Multi-Axis Pintle Thrusters (다축 핀틀 추력기 구동 메카니즘의 특허 분석)

  • Kim, Seong-Su;Huh, Hwan-Il;Lee, Ho-Sung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.262-267
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    • 2012
  • For DACS system which controls pintle position to change nozzle throat area, one actuator has been used for each modulatable pintle thruster. This ten actuator system drove to complex system structure and complicated control mechanism. In order to overcome this shortcomings, international patents were reviewed, analysed and presented.

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Effect of Bore an Aerodynamic Loads in Modulatable Thrust Devices (노즐목 가변 추력기에서 Bore가 구동기의 공력하중에 미치는 영향)

  • Wang, Seung-Won;Huh, Hwan-Il
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.04a
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    • pp.189-192
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    • 2011
  • In solid rockets, a pintle thruster is a modulatable thrust device which controlls nozzle throat area. In this study, effect of bore on aerodynamic loads in a SNECMA modulatable thruster was carried out. Existence of bore resulted in reduced aerodynamic load.

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Flow analysis of Buoyant Jets into Storage Tank through Variable Nozzles (각종 Nozzle을 통하여 저장조내로 유입되는 BUOYANT JETS의 유동해석)

  • Pak, Ee-Tong;Cho, Woon
    • Solar Energy
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    • v.9 no.2
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    • pp.42-50
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    • 1989
  • The Buoyant Jets were analysed experimentally changing flow rate (0.0291/s, 0.0371/s, 0.0451/s), ratio of nozzle tip area to throat area (aspect ratio ${\beta}$=0.4, 1.0, 1.9), and also the temperature difference (${\Delta}T=Ti-T{\infty}$) between the temperature of the inflow water into the storage tank ($1m{\times}1m{\times}3m$) and the mean temperature of the water in the storage tank were changed as $25^{\circ}C,\;35^{\circ}C$ and $45^{\circ}C$. The more aspect ratio decreased, the more the trajectories of Buoyant Jets center-line were decreased and not the more the trajectories of Buoyant Jets centerline were influenced by the increment of the difference of the temperature. The more aspect ratio decreased, the more the half widths and dilution ratio of Buoyant Jets were increased and not the more the half widths and dilution ratio of Buoyant Jets were influenced by the increment of the difference of the temperature. Fr number is the factor that can predict the flow pattern over the whole flow field. And yet for the consideration the near field of Buoyant Jets flow pattern is dominated by magnitude of momentum and buoyancy force.

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Evaluation of Structural Performance of Natural Draught Cooling Tower According to Shell Geometry Using Wind Damage Analysis - Part II : Two-Shell Geometry (풍하중에 의한 손상해석을 이용한 기하형상에 따른 자연 습식 냉각탑의 구조성능 평가 - Part II : Two-Shell 기하형상)

  • Lee, Sang-Yun;Noh, Sam-Young
    • Journal of Korean Association for Spatial Structures
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    • v.17 no.1
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    • pp.49-58
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    • 2017
  • The result of the previous work leads to the idea that the inner area of the hyperbolic shell generator should be minimized for the cooling tower with higher first natural frequency. In this study the inner area of the hyperbolic shell generator was graphically established under varying height of the throat and angle of the base lintel. From the graph, several shell geometries were selected and analysed in the aspect of the natural frequency. Three representative towers reinforced differently due to different first natural frequencies were analysed non-linearly and evaluated using a damage indicator based on the change of natural frequencies. The results demonstrated that the damage behaviour of the tower reinforced higher due to a lower first natural frequency was not necessarily advantageous than the others.

A Study for Testing Validity of Korean Pain Measurement Tool (국어통증척도의 타당도 연구)

  • 김주희
    • Journal of Korean Academy of Nursing
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    • v.16 no.1
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    • pp.81-88
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    • 1986
  • The main purpose of this study was to clarify the validity with patient's general background of Korean Pain Measurement tool. The subjects of this study were 195 patient from the 8 Med-Surgical wards in H. University Hospital in Seoul. The study was conducted over a 40 day period from Oct. 5, 1985 to Nov. 15, 1985. All patients had pain. Korean Pain Measurement tool and simple discriptive pain scale as Graphic Rating Scale were used to measure the pain, The Pearson Correlation Coefficient test was exercised to measure the correlation between the two kinds of pain tools. To clarify the Sensitivity of Korean Pain tool was used frequency with patient's response. To compare the difference in Pain levels with patient's general background, ANOVA and t-test was employed. To compare the difference in pain levels existed due to pain area of the body used mean numbers. The outcome of the study was as follows : 1. A positive correlation did exist between two pain measurement tools. (r=.2028∼.7768, p <0.002) 2. The sensitive subclass in Korean Pain Measurement tools was 7 subclass. The 7 subclass are inflammatory repeated pain, simple stimulating, traction pressure, dull pain, cavity pain, digestion related pain, suffering. related pain. 3. The existence of levels of pain in accordance with patient's general background, the department of hospital, pain area of the body and school age was supported. Age, sex, religion, marrital status, economic status, acute or chronic status was not supported. 4. The existence of higher pain levels of the body area was anus, chest, and lower pain levels of the body area was eye, ear, nose and throat. Based on the above results, it was found that sensitive subclasses of the Korean Pain Measurement tool was 7 subclass among all of 20 subclass. Thus it can be concluded that Korean Pain Mea-surement tool when partialy used and supplemented, can be an effective tool of pain measurement for the patient in Korea.

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Evaluation of Critical Pressure Ratios Sonic Nozzle at Low Reynolds Numbers (음속 노즐의 임계 압력비에 대한 저 레이놀즈수의 영향)

  • Choe, Yong-Mun;Park, Gyeong-Am;Cha, Ji-Seon;Choe, Hae-Man;Yun, Bok-Hyeon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.11
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    • pp.1535-1539
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    • 2000
  • A sonic nozzle is used as a reference flow meter in the area of gas flow rate measurement. The critical pressure ratio of sonic nozzle is an important factor in maintaining its operating condition. ISO9300 suggested the critical pressure ratio of sonic nozzle as a function of area ratio. In this study, 13 sonic nozzles were made by the design of ISC9300 with different half diffuser angles of 2。 to 8。 and throat diameters of 0.28 to 4.48 mm. The test results of half diffuser angles below 8。 ar quite similar to those of ISO9300. On the other hand, the critical pressure ratio for the nozzle of 8。 decreases by 5.5% in comparison with ISO9300. However, ISO9300 does not predict the critical pressure ratio at lower Reynolds numbers than 10(sup)5. Therefore, it is found that it is a better way for the flow of low Reynolds number to express the critical pressure ratio of sonic nozzle as a function of Reynolds number than area ratios. A correlation equation of critical pressure is introduced with uncertainty $\pm$3.2 % at 95% confidence level.