• 동아시아식생활학회지
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• 제19권6호
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• pp.1049-1053
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• 2009

본 연구는 두충을 주 원료로 고안된 한방 혼합 다류가 고혈압 질환자의 혈압, 혈청지질 및 혈액학적 변화에 미치는 영향을 평가하기 위하여 수행하였다. 한방 혼합 다류를 시험 4주간 복용한 그룹과 시험 전 그룹을 비교한 결과, 수축기 혈압은 167.14 mmHg에서 134.86 mmHg로, 이완기 혈압은 100.00 mmHg에서 87.10 mmHg로 뚜렷하게 저하되었다. 혈청지질 중 총콜레스테롤(TC), 고밀도-콜레스테롤(HDL-C), 저밀도-콜레스테롤(LDL-C)의 농도 및 동맥경화지수(AI)는 유의적인 차이가 없었다. 반면, 한방 혼합 다류를 복용 시 중성지방(TG) 농도가 237.10 mg/dL에서 145.00 mg/dL로 강하게 감소되었다. 시험 4주 후와 시험개시 전의 혈액학적 지표(적혈구, 백혈구, 헤마토크리트, 헤모글로빈, 혈소판 및 호모시스테인)를 비교한 경우, 유의적 변화는 관찰되지 않는 반면 평균 적혈구 혈색소 농도(MCHC)는 유의적으로 2.70% 증가되었다. 이상의 결과로 부터 두충을 주 원료로 고안된 한방 혼합 다류는 중성지방 농도를 감소시킴으로써 혈압을 저하시키는 것으로 추정하며, 평균 적혈 수혈 색소 농도를 증가시킴을 확인하였다.

• 전기학회논문지P
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• 제59권1호
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• pp.77-82
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• 2010

This study evaluated the characteristics and reliability of an auger crane with a built-in hydraulic extender. The field test of the hydraulic extender was performed with the hydraulic lines filled with hydraulic fluid and free of air. The pressure generated during the test was measured with a digital pressure gauge. The crane was considered to have undergone one cycle of the excavation process after it had performed excavation under three conditions at the same location. This process was performed three times in total. From the results of the excavation using the hydraulic extender, it was found that the maximum pressure and torque measured were 19.9 [MPa] and 895.4 [$kgf{\cdot}m$], respectively. The rotation force of the auger crane generated at this time signifies a horizontal force. If the excavation diameter of the auger crane is increased, the rotation speed is reduced causing the circumferential speed to also be reduced. The torsional shear stress of the extendable auger crane was calculated to be approximately 23.5 [MPa]. However, the rotation shaft material used for this system was carbon steel for machine structural use (SM45C). Since the minimum torsional yield stress is greater than 150 [MPa] according to KS D 3752, it means the equipment has secured a safety factor greater than 6. Therefore, it was found that when performing work using the extendable auger crane, it exhibited no problems with the safety and reliability of its shaft.

• 대한기계학회논문집B
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• 제20권9호
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• pp.2944-2952
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• 1996

In this paper the CSCM type upwind flux difference splitting Navier-Stokes method has been applied to study the ARL-SL19 transoni $c^ersonic compressor cascade flow. First, the general characteristics of baseline cascade flow were analyzed. At freestream Mach n.1.612 and exit/inlet pressure ratio 2.15, the results from current laminar flow were compared well in suction surface with the experiment; however, not well in pressure surface. Second, numerical study of the transoni $c^ersonic compressor cascade flow demonstrated the effectiveness of a passive control by the various size cavities. A cavity under the shock foot point at the suction surface of the blades was used as a passive control. The passive control of shock-boundary layer interaction by a cavity reduced total pressure losses. The effect of cavity length and depth was studied. The total pressure loss was reduced by about 10% and the isentropic efficiency was improved slightly. The effect of cavity depth in current study(d/l = 0.05, 0.02) was not found strong. Further adequate turbulence modeling and TVD schemes would help to capture the shock more accurately and increase the effectiveness of the current shock-boundary layer interaction study using upwind flux difference splitting computational methods.thods.

• 한국수소및신에너지학회논문집
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• 제24권6호
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• pp.524-534
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• 2013

Gasoline direct injection(GDI) engine has a high thermal efficiency, but it has a problem to increase carbon emissions such as soot and $CO_x$. In this study, the objective is to analyze numerically a problem for adding the hydrogen during the intake stroke so as to reduce the injected amount of gasoline in GDI engines. For selection of the base model, the cylinder pressure of simulation is matched to experimental data. The numerical analysis are carried out by a CFD model with the hydrogen addition of 2%, 3% and 4% on the volume basis. In the case of 3% hydrogen addition, the injected gasoline amount is only changed to match the maximum pressure of simulation to that of the base model for additional study. It is found that the combustion temperature and pressure increase with the hydrogen addition. And NO emission also increases because of the higher combustion temperature. $CO_x$ emissions, however, are reduced due to the decrease of injected gasoline amount. Also, as the injected gasoline amount is reduced for the same hydrogen addition ratio, the gross indicated work is no significant, But NO and $CO_x$ emissions are considerably decreased. On the order hand, $CO_x$ emissions of two cases are more decreased and their gross indicated works are higher obtained than those of the base model.

• 대한한의학회지
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• 제18권1호
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• pp.299-315
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• 1997

The present experiments were designed to investigate the effects of Samsaengyeum. water extracts on the Cardiovascular System in the Experimental Animals. Thus, the changes of blood pressure and heart rate were measured after oral administration. Measurement of Mortality rate was observed for measuring the effect of Samsaengyeum water extract Samsaengyeum water extract against pulmonary thromboembolism induced by collagen the mixture(0.1me/10g, 2mg/kg B.W) plus serotonin(5mg/kg B.W) in mouse. The effect of Samsaengyeiim water extract was examined by observing the change of collagen-induced platelet aggregation, coagulation activity, ex vivo and in vitro fibrinolytic activity of euglobulin fraction in rats. The results were summarized as followings. 1. Samsaengyeum dropped the blood pressure in spontaneous hypertensive rat. 2. The drug increased the auricular blood flow in rabbit. 3. The drug relaxed the artery contraction by pretreated norepinephrine in rat. 4. The drug inhibited the death rate of mouse which was led to thromboembolism by serotonin and collagen. 5. The drug inhibited the platelet aggregation in rat. 6. The drug prolonged the prothrombin time and activated partial thromboplastin time on the test of plasma coagulation factor activity in rat, but was not valuable. 7. The drug reduced the fibrinogen lyses time and increased the lyses area of rat. 8. Samsaengyeum reduced fibrinogen lyses time of rat in vitro assay. According to the above mentioned results, Samsaengyeum increased the blood flow and dropped the blood pressure by the dilation of blood vessel. And the drug inhibited the platelet aggregation.

• 한국운동역학회지
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• 제31권2호
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• pp.104-112
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• 2021

Objective: This study aimed to analyze the effects of consecutive whole body vibration through heel raise posture on the center of pressure and electromyography of anterior tibial muscle, lateral gastrocnemius and soleus muscles during single-leg stance. Method: The subjects of this study included 30 healthy males in their 20's, with the following inclusion criteria: no history of orthopaedic medical history, no participation in regular exercises, no history of whole body vibration exercise, and right leg being the dominant leg. The experimental procedure involved pretreatment measurement of eye open single-leg stance, application of whole body vibration for 30 seconds, post-treatment measurement (3 measurements in total). Static and dynamic movements have been measured over 2 separate experiments, with 72 hours gap between the experiments. Static movement involved maintaining single-leg heel raise posture for 30 seconds while applying whole body vibration, and dynamic movement involved heel raise (15 repetitions over 30 seconds) while applying whole body vibration. The strength of applied whole body vibration was 35 Hz frequency and 2~4 mm amplitude. Results: As the single-leg posture after static heel raise posture, mediolateral velocity of the center of pressure at post 2 and post 3 were significantly reduced compared to the pre-treatment measurement. In addition, the percentage for reference voluntary contraction in anterior tibial muscle and soleus and median frequency at anterior tibial muscle and lateral gastrocnemius muscle at post 3 were significantly decreased compared to the pre-treatment value. As the single-leg posture after dynamic heel raise posture, the mediolateral 95% edge frequency of the center of pressure and median frequency at anterior tibial muscle, lateral gastrocnemius muscle, and soleus muscle at post 3 were significantly reduced compared to the pre-treatment value. Conclusion: Acute whole body vibration via static and dynamic heel raise posture have positive effect on mediolateral posture control during single-leg stance.

• Wind and Structures
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• 제30권2호
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• pp.181-198
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• 2020

In the traditional buffeting response analysis method, the spanwise incomplete correlation of buffeting forces is always assumed to be same as that of the incident wind turbulence and the action of the signature turbulence is ignored. In this paper, three typical bridge decks usually adopted in the real bridge engineering, a single flat box deck, a central slotted box deck and a two-separated paralleled box deck, were employed as the investigated objects. The wind induced pressure on these bridge decks were measured via a series of wind tunnel pressure tests of the sectional models. The influences of the wind speed in the tests, the angle of attack, the turbulence intensity and the characteristic distance were taken into account and discussed. The spanwise root coherence of buffeting forces was also compared with that of the incidence turbulence. The signature turbulence effect on the spanwise root coherence function was decomposed and explained by a new empirical method with a double-variable model. Finally, the formula of a sum of rational fractions that accounted for the signature turbulence effect was proposed in order to fit the results of the spanwise root coherence function. The results show that, the spanwise root coherence of the drag force agrees with that of incidence turbulence in some range of the reduced frequency but disagree in the mostly reduced frequency. The spanwise root coherence of the lift force and the torsional moment is much larger than that of the incidence turbulence. The influences of the wind speed and the angle of attack are slight, and they can be ignored in the wind tunnel test. The spanwise coherence function often involves several narrow peaks due to the signature turbulence effect in the high reduced frequency zone. The spanwise coherence function is related to the spanwise separation distance and the spanwise integral length scales, and the signature turbulence effect is related to the deck-width-related reduced frequency.

• 한국의류산업학회지
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• 제18권5호
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• pp.716-723
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• 2016

The purpose of this study was to investigate the change in blood velocity(mm/sec) when compression and/or heat were applied to the knee joint for the elderly who has both normal and painful legs with osteoarthritis(OA). Experimental compression knee band was prepared from the 3D knee data of the average women in 60's. 3D replica of knee was reduced by 7, 10, and 13% from the nude pattern in course direction. Clothing pressure was measured at the front and back of each healthy and painful knee of elderly women for one minute while standing and sitting on the chair. Blood velocity was measured at 13 cm upper from the mid-patella for 15 minutes. Results are as follows: first, compression or heating treatment itself did not change blood velocity of both legs; second, combination treatment with heating and compression was effective to increase blood velocity. In details, for healthy legs, combination treatments with compression by 10% reduced pattern(about 1.3kPa) and heating($43^{\circ}C$) induced the maximal blood velocity, however, for knees with OA, 7% reduced pattern(about 1.0kPa) with simultaneous heating($43^{\circ}C$) was more effective than other cases. These results indicated that pain and spasticity of knee joint with OA could be reduced by applying heat and compression therapy, where the compression level of painful knee should be slightly lower than of healthy leg.

• 한국산학기술학회논문지
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• 제18권9호
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• pp.480-485
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• 2017

저널 베어링인 선미관 후부 베어링의 후방부에 발생하는 발열 사고는 프로펠러 하중이 추진축을 처지게 하여 후방부에 과도한 국부압착압력이 작용하는 것이 주된 원인이다. 선미관 베어링의 라이닝 재료로 사용되는 화이트 메탈보다 영률이 훨씬 작은 재료를 사용한다면 축과의 접촉 면적을 크게 함으로써 발열 사고의 원인이 되는 국부압착압력의 저감이 가능할 것이다. 본 연구의 목적은 영률이 작은 재료로 만들어진 베어링 제품의 적용에 앞서, 축계 해석을 통해 새로운 제품 적용시의 압착압력 분포특성을 파악하고 허용 압력을 결정하는데 있다. 국부압착압력의 계산에 있어서는 접촉 너비를 따라 반 타원형상의 압력 분포를 가정한 Hertzian 접촉 조건을 도입하였으며, 엔진 가동 상태의 프로펠러 하중, 열 효과 및 선체 변형을 고려하였다. 해석 결과를 통해 영률이 작은 제품은 기존 제품을 적용한 실적선에 비해 국부압착압력의 상당한 저감이 가능함을 확인하였고, 또한 하중 조건이 바뀌더라도 압력 분포의 변화가 작아 강건 설계가 가능한 장점이 있음을 알 수 있었다. 본 연구를 통해 제시되는 제품의 성능 사양을 제조사가 보장한다면 영률이 작은 제품의 적용이 가능하리라 판단된다.

• Applied Biological Chemistry
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• 제37권1호
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• pp.9-13
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• 1994

백하주의 증류현상을 살피보기 위하여 전통약주인 백하주를 제조하고 압력(760, 460, 260 mmHg)과 환류비(3.1 : 1, 1 : 1) 및 충전물질의 유무에 따른 증류조작에 대하여 연구한 결과는 다음과 같다. 백하주의 alcohol함량은 14.2%, 산도는 8.3 g/100 ml, ethyl acetate는 49 ppm, fusel oil은 657 ppm이었다. 증류가 진행됨에 따라 증류액의 alcohol 농도는 감소하였으며, 분액별 alcohol 농도는 상압이 감압 보다 높았다. Still액과 증기상의 alcohol 농도의 관계를 나타내는 기울기는 압력이 높을수록 크게 나타났다. 비환류시 증류종말점은 8분액 이었지만 환류시는 5분액 이었다. 또한 환류시 alcohol 평균농도는 환류비가 높을수록 증가하였으며, 상압상태에서 환류비가 3.1 : 1과 1 : 1 일 때 각각 0.56, 0.54 mole이었다. 증류속도는 증류가 진행됨에 따라 감소하였으며, 상압보다 감압에서 빨랐고 충전상태의 260 mmHg에서 0.14 ml/sec로 가장 빨랐다. 환류시는 환류비가 높을수록 감소하였고 평균 증류속도는 상압상태에서 환류비가 3.1 : 1과 1 : 1일 때 각각 0.05, 0.06 ml/sec이었다.