• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.541-546
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• 1987

An experimental study has been conducted to investigate the suction performance of a designed inlet. Total pressure distortion in the inlet S-duct was measured and the effect of lip thickness and throat area was analyzed. The volume flow rate of air into the turbojet engine was controlled to observe the effect of engine RPM to the total pressure distortion. The pressure data from 36 air tubes were obtained using scanivalve, pressure transducer, and visicoder system.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2003년도 제20회 춘계학술대회 논문집
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• pp.123-126
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• 2003

실험에서 측정변수에 발생되는 불확도가 터빈 전효율의 불확도에 미치는 영향을 실험을 통하여 분석하였다. 단단 축류형 3차원 터빈이 실험에 사용되었으며 평균반경에서 반동도가 0.373이며 상온 저압 상태에서 실험이 수행되었다. 입구/출구전압력에 의하여 발생되는 불확도는 터빈 전효율의 불확도로 전파되는 영향이 상당히 크게 나타나므로 상온저압시험에서는 높은 정밀도를 갖는 압력계가 필요하게 된다. 측정변수의 불확도가 전효율의 불확도에 차지하는 영향은 토오크에 의하여 발생되는 불확도가 가장 크게 나타났으며 회전수에 의한 불확도가 가장 적었다. 토오크의 불확도 영향은 회전수의 증가에 따라 증가하는 경향이 있다. 전압력의 경우는 출구측에서의 불확도가 입구측에 비하여 영향력이 크게 나타났다.

• 한국초전도ㆍ저온공학회논문지
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• 제8권3호
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• pp.5-8
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• 2006

The effect of annealing time in Metal Organic Deposition(MOD) method was investigated at reduced total pressure. As the total annealing pressure was reduced, the growth rate of YBCO films increased from 0.14nm/sec at atmospheric pressure to 4.2nm/sec at 1 Torr. For the total pres sure of 700, 500, 300, 100, and 1 Torr, the optimal annealing times of 60, 40, 20, 10, 2minutes were found in our experimental conditions. When the an nealing time was short, poor crystallinity or un-reacted phase was obtained. Also, the degradation of YBCO films occurred when exposed longer to the humid ambient at the high annealing temperature. The reduced pressure was found effective to in crease the growth rate and to control the pore size of the YBCO films in MOD method. A fast growth of MOD-YBCO films was realized with high critical current density over $1MA/cm^2$ using reduced pressure annealing. Large pores, usually observed at atmospheric pressure in MOD method, disappeared and also, the number of pores was reduced.

• 대한치과기공학회지
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• 제11권1호
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• pp.89-93
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• 1989

The purpose of this study was to evaluate the effect of sprue length and casting pressure on the relative castability of the base metal alloys, commonly used to make porcelain metal restoration. Samples of total 30 were constucted and devided into 6 groups according to three variables (low, medium, high). The total number of complety cast squares were counted, verified and recorded. The results of this 1. main effect of casting pressure was statistically significant.(P<0.05). 2. main effect of sprue length was not statistically significant.

• 한국항공우주학회지
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• 제31권8호
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• pp.107-114
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• 2003

본 연구에서는 터빈 전효율의 불확도에 영향을 미치는 측정변수들의 불확도에 대한 영향을 실험의 결과로부터 분석하였다. 실험에 사용된 터빈은 축류형 3차원 단단터빈으로써 평균반경에서 반동도가 0.373이며 상온저압 상태에서 실험이 수행되었다. 입구전압력과 출구전압력에 의하여 발생되는 불확도는 전효율의 불확도에 전파되는 영향이 상당히 크게 나타나므로 상온저압시험에서는 높은 정밀도를 갖는 압력계를 사용하여야 한다. 측전변수의 불확도가 효율의 불확도에 차지하는 영향은 토오크에 의하여 발생되는 불확도가 가장 크게 나타났으며 회전수의 불확도가 가장 적었다. 토오크의 불확도 영향은 회전수의 증가에 따라 증가하는 경향이 있다. 전압력의 경우는 출그측에서의 불확도가 입구측에 비하여 영향력이 크게 나타났다.

• 한국세라믹학회지
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• 제45권5호
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• pp.280-284
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• 2008

In order to investigate residence time effect on the growth of ZrC film, the ZrC films grew with various system total pressure (P) and total flow rate (Q) by low pressure chemical vapor deposition because residence time is function of system total pressure and total flow rate. Thermodynamic calculations predict that the decomposition of source gases ($ZrCl_4$ and $CH_4$) would be low as increasing the residence time. Thermodynamic calculations results were proved by investigating deposition rate with various residence time. Deposition rate decreased with residence time of source gas increased. Besides, depletion effect accelerated diminution of deposition rate at high residence time. On the other hands, the deposition rated was increased as decreasing the residence time because fast moving of intermediate gas species decrease the depletion effect. The crystal structure was not changed with residence time. However, the largest size of faceted grain showed up to specific residence time and the size of grain was decreased whether residence time increase or not.

• Journal of Mechanical Science and Technology
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• 제14권4호
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• pp.456-465
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• 2000

An experiment was conducted to investigate the aerodynamic losses of high pressure steam turbine nozzle (526A) subjected to a large range of incident angles ($-34^{\circ}\;to\;26^{\circ}$) and exit Mach numbers (0.6 and 1.15). Measurements included downstream Pitot probe traverses, upstream total pressure, and end wall static pressures. Flow visualization techniques such as shadowgraph and color oil flow visualization were performed to complement the measured data. When the exit Mach number for nozzles increased from 0.9 to 1.1 the total pressure loss coefficient increased by a factor of 7 as compared to the total pressure losses measured at subsonic conditions ($M_2<0.9$). For the range of incidence tested, the effect of flow incidence on the total pressure losses is less pronounced. Based on the shadowgraphs taken during the experiment, it' s believed that the large increase in losses at transonic conditions is due to strong shock/ boundary layer interaction that may lead to flow separation on the blade suction surface.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.353-358
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• 2004

Tracing the study of the burst test of steam generator tube, few studies have been reported to effect of external pressure acting on secondary-side in service condition. In this study the burst tests of Inconel 690TT were conducted in order to evaluate burst strength characteristics under the effect of external pressure. We obtained the result that the burst strength of Inconel 690TT increased when external pressure increased while both total circumferential elongation and uniform burst elongation were not affected. Also, according to the increased of external pressure, the size of the burst opening became smaller and the tear was getting severe.

• 대한한방내과학회지
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• 제11권1호
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• pp.109-120
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• 1990

In order to investigate the therapeutic effects on blood pressure and hyper cholesteremia, aqueous extract of Chin Gan Sik Pung Tang were studied. The result of the total cholesterol contents in serum and blood pressure of each group were as follows, 1. The aqueous extract of Chin Gan Sik Pung Tang inhibited increased Total cholesterol in serum of rabbits administrated with cholesterol rich diet. 2. Blood pressure manifested gradual response by the fall of 4, 3, 9.2, 19.9 percent in proportion to the administration of 10, 30, 100 mg/kg of Chin Gan Sik pung Tang, respectively 3. Administration of Chin Gan Sik Pung Tang to the rabbit pretreated with Vagotomy, Atropine and Regitine did not show any significant difference in the blood pressure, compare with that of the control group. 4. Administration of Chin Gan Sik Pung Tang to the rabbit pretreated with propranolol show significant difference in the blood pressure, compare with that of the control group. From the above results, it is suggested that Chin Gam Sik Pung Tang has the action on adrenergic ${\beta}-receptor$ and can he used therapeutic effect on the hypertension, and inhibit the increase of Total Cholesterol contents in serum.

• 대한기계학회논문집B
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• 제26권9호
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• pp.1292-1301
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• 2002

An experimental study of turbine performance is conducted with various incidence angles on a rotating turbine rotor. 5 different incidence angles are applied from -17$^{\circ}$to 13$^{\circ}$with 7.5$^{\circ}$gaps. In order to precisely set up the incidence angles at the rotor inlet, 5 turbine discs are manufactured with the different fir tree section. Total-to-total efficiencies are obtained on the several off-design points with considering the exit total pressure, which is meas fred at 12 locations between the hub and casing using a pressure rake. The degree of reaction is 0.373 at the mean radius, and Reynolds number based on the rotor chord is 0.86$\times$10$^{5}$ at the turbine inlet on the design point experiment. The experiment on a single-stage turbine is conducted at the low-pressure and low-speed state, but it is sufficient to consider the blade loading effect due to the rotating apparatus even though the total pressure loss at the exit is increased proportionally to the turbine output power. The experimental results recommend 6$^{\circ}$as an optimum incidence angle on the turbine blade design. The total-to-total efficiency is steeply decreased when the incidence angle is over $\pm$9$^{\circ}$ from the optimum incidence angle. In the range of less than -10$^{\circ}$incidence angle, 7.5$^{\circ}$ reduction of incidence angle generates 15% decrease of total-to-total efficiency. This result is obtained on the same rotor blade by changing only the rotational speed to minimize the effect of profile and secondary flow loss in the passage. Experimental results show that the change rate of total-to-total efficiency according to the incidence angle change is unchanged although the turbine operates at the off-design condition.