• 천문학회지
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• 제46권4호
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• pp.151-159
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• 2013

We discuss the orbital period changes of the Algol semi-detached eclipsing binary DI Peg by constructing the (O-C) residual diagram via using all the available precise minima times. We conclude that the period variation can be explained by a sine-like variation due to the presence of a third body orbiting the binary, together with a long-term orbital period increase (dP/dt=0.17 sec/century) that can be interpreted to be due to mass transfer from the evolved secondary component (of rate $1.52{\times}10^{-8}M_{\odot}/yr$) to the primary one. The detected low-mass third body ($M_{3min.}=0.22{\pm}0.0006M_{\odot}$) is responsible for a periodic variation of about 55 years light time effect. We have determined the orbital parameters of the third component which show a considerable eccentricity $e_3=0.77{\pm}0.07$ together with a longitude of periastron ${\omega}_3=300^{\circ}{\pm}10^{\circ}$.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.770-776
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• 2000

This paper represents our efforts to diagnose nutrient stresses using physiological instruments in cucumber plants. The stresses could be detected by measuring and analyzing the difference of chlorophyll content, photosynthetic efficiency(Fv/Fm), differential temperature(DT), stomatal resistance and light absorbance values between deficient and controlled plants. From the all over experiments, the stresses could be first diagnosed in the 8th day after treatment and the overall diagnosis rate was estimated at more than 50%.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.III
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• pp.736-743
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• 2000

This paper represents our efforts to diagnose environmental stresses using physiological instruments in cucumber plants. The stresses could be detected by measuring and analyzing the difference of chlorophyll content, photosynthetic efficiency(Fv/Fm), differential temperature(DT), stomatal resistance and light absorbance values between treated and controlled plants. From the all over experiments, the stresses could be first diagnosed on the 1st to 5th day after treatment and the overall diagnosis rate was estimated at more than 50%.

• Journal of Chest Surgery
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• 제23권1호
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• pp.9-15
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• 1990

This study was designed to investigate the protective effect of chlorpromazine against the reperfusion injury of myocardium after high potassium cardioplegic arrest. Langendorff`s preparations of rat heart were infused with high potassium cardioplegic solution[St. Thomas Hospital Solution] at 25oC. Chlorpromazine [10-7Ｍ] increased the recovery of myocardial contractility[dp/dt], left ventricular pressure[LVP], and coronary flow rate of the reperfused heart. Both in control and experimental groups, the restoration of myocardial activity could not reach to the level of preplegic control. These results suggest that the etiologic factors of the reperfusion injury include the influence of high potassium cardioplegic solution and/or reperfusion itself, and that chlorpromazine protects myocardium from the reperfusion injury.

• 에너지공학
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• 제6권2호
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• pp.198-202
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• 1997

The oxidation behavior of UO$_2$pellets was studied using a thermogravimetric analyzer and an XRD in the temperature range of 300 to 550$^{\circ}C$ in air. From XRD studies it is found that UO$_2$is converted to U$_3$O$\_$8/ and the weight gains of UO$_2$specimen are characterized by S-shape curves. After complete oxidation the specimens broke into fine powder and the average weight gain was about 3.93 wt%. The activation energy of 50% conversion of UO$_2$to U$_3$O$\_$8/ is 81.6 kJ/mol and the oxidation rate per unit time was found to be as follows dw/dt=6.54${\times}$10$\^$6/ e (equation omitted), wt%/h : at 50% conversion of UO$_2$into U$_3$O$\_$8/ where w, t and T were wt% gain, conversion time and temperature, respectively.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1992년도 한국우주과학회보 제1권1호
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• pp.11-11
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• 1992

The most celebrated problem in artificial satellite theory is undoubtedly the critical inclination problem. The KITSAT-1 satellite launched by Arian 42P from Guiana in August 11, 1992 has orbital inclination close to the critical value cos-1(1/rs). In that case, there is a singularity in some perturbation terms and therefore perigee will be fixed because do/dt is equals to zero. But actually the long periodic behaviour in argument of perigee, u is affected by luni-solar gravity andrelativistic effect, etc. Luni-solar gravity induces periodic perturbations in allorbital elements except the semi-major axis, and secular variations in 0, u and M.We have obtained nodal rate and inclination variations in case of the KITSAT-1.In this paper, we will also show the geopotential perturbations in 0, M of the Satellite in CIUding J2, J3, J4, J22 terms.

• 한국환경보건학회지
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• 제17권1호
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• pp.39-49
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• 1991

고온에서 황화수소(H$_{2}$S)를 제거하기 위한 흡착제를 개발할 목적으로 ZnO에 $Fe_{2}O_{3}$를 5~50 atomic %까지 첨가시켜 제조한 다공성 흡착제와 황화수소와의 반응(sulfidation)을 thermogravimetric analyzer (Shimadzu DT-30)로 수행하였으며, 고정층세서 zinc ferrite 흡착제의 흡착능을 측정하였다. 반응온도는723$^{\circ}$K~973$^{\circ}$K범위이며, 반응기체는 황화수소(2vol.%)와 질소와 혼합기체로서 total gas flow rate는 200ml/min으로 고정시켰다. Grain Model을 사용하여 실험데이터를 분석한 결과 전화율이 낮을 때 zinc ferrite와 황화수소 반응의 율속단계는 화학반응이었고 황화수소 농도에 대해 1차 반응이었다. 실험한 흡착제 중 10 atomic %의 $Fe_{2}O_{3}$를 첨가하여 제조한 zinc ferrite형 흡착제가 반응속도, 흡착능, 그리고 재생성면에서 우수한 흡착제로 밝혀졌다.

• 천문학회지
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• 제48권1호
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• pp.1-7
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• 2015

The orbital period changes of the W UMa eclipsing binary AU Ser are studied using the (O-C) method. We conclude that the period variation is due to mass transfer from the primary star to the secondary one at a very low and decreasing rate $dP/dt=-8.872{\times}10^{-8}$, superimposed on the sinusoidal variation due to a third body orbiting the binary with period $42.87{\pm}3.16$ years, orbital eccentricity $e=0.52{\pm}0.12$ and a longitude of periastron passage ${\omega}=133^{\circ}.7{\pm}15$. On studying the magnetic activity, we have concluded that the Applegate mechanism failed to describe the cycling variation of the (O-C) diagram of AU Ser.

• Agricultural and Biosystems Engineering
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• 제2권1호
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• pp.1-6
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• 2001

This paper represents methods to diagnose nutrient deficient stresses of cucumber plants using several physiological instruments. The stresses could be detected by measuring and analyzing the difference of chlorophyll content, photochemical efficiency (Fv/Fm), temperature difference (DT) and light absorbance at wavelengths of 480nm, 560nm and 710nm between deficient and control plants. From the all over experiments, the stresses could be first diagnosed in the 3rd to 5th day in general after treatment and the overall diagnosis rate was estimated at more than 50% up to 100%.

• Journal of Plant Biology
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• 제21권1_4호
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• pp.33-38
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• 1978

Phosphate absorption from a Na2H32PO4 solution by Oryza sativa L. was studied in order to elucidate kinetic mechanisms of ion transport. The rates of phosphate absorption from different concentraitons indicated the presence of dual mechanisms in root tips, one in the low (1$\times$10-6 to 8$\times$10-5M) and the other in the high (1$\times$10-4 to 8$\times$10-3M). A phosphate compensation point of phosphate transport was revealed with a 1$\times$10-6M solution of Na2H32PO4. The kinetic model that ion transport involves an exchange reaction of absorption and desorptin is prosposed as follows: where C represents an ionic-specific organic carrier in the membrane; M, Mo and Mi are the mineral ions, M-outside and M-inside; MC is a carrier-ion complex; and the K's represent rate constants. In this model, the Mi velocity, v, is given by: {{{{v= {dMi} over {dt}= {(K1K3Mo-K2K4Mi) Ct} over {(K2＋K3)＋K1Mo＋K4Mi} }} where Ct is equal to C＋MC, and t is time.