• Journal of the Korean Solar Energy Society
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• v.36 no.5
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• pp.63-71
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• 2016

Installed PV module in field is affected by shading caused by various field environmental factors. Bypass diodes are installed in PV module for preventing a power loss and degradation of PV module by shading. But, Bypass diode is easily damaged by surge voltage and has often initial a defect. This paper propose the electric characteristic variation and the power prediction of PV module with damaged bypass diode. Firstly, the resistance for normal bypass diode and damaged bypass diode of resistance was measured by changing the current. When the current increases, the resistance of normal bypass diode is almost constant but the resistance of damaged bypass diode increases. Next, To estimate power of PV module by damaged bypass diode, the equation for the current is derived using solar cell equivalent circuit. Finally, the derived equation was simulated by using MatLab tools, was verified by comparing experimental data.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.424.2-424.2
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• 2016

Solar cell converts light energy to electric energy. But a solar cell generates low power, PV module is fabricated by connected in series with dozens of solar cell. Owing to solar cell connected in series, power of PV module is influenced by shading or mismatch power of solar cells. To prevent power loss of PV module by shading or mismatch current, Bypass diodes are installed in PV module. Bypass diode operating reverse voltage by shading or mismatch power of solar cells bypass mismatch current. However, bypass diode in module exposed outdoor is easily damaged by surge voltage. In this paper, we confirm characteristics variation of PV module with damaged bypass diode. As a result, power of PV module with damaged bypass diode is reduced and Temperature of that is increased.

• Journal of Chest Surgery
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• v.18 no.2
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• pp.193-204
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• 1985

During the period from February to March, 1984, we employed a partial left heart bypass [left atrium to ascending aorta] in 2 patients who could not weaned from cardiopulmonary bypass with inotropic agents and cardiac pacing after coronary bypass surgery. These two patients showed significant improvement in ventricular function 18 to 47 hours after inserting the left heart bypass and were able to wean from the left heart bypass under using inotropic agents. Two patients died of multiple organ failures 11 days and 15 days postoperatively. These results indicate that early institution of left heart bypass in ventricular failure patients after open heart surgery can provide satisfactory long-term result.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.203-210
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• 1988

The clinical experience with the activated clotting time[A.C.T.] for the control of heparin and protamine therapy during cardiopulmonary bypass in 40 patients between April, 1987 and September, 1987 is reviewed retrospectively. All of patients used with cold blood potassium cardioplegia for myocardial protection under standard cardiopulmonary bypass, priming and perfusate techniques respectively. This study was divided into 2 groups of patients followed by cardiopulmonary bypass time. Twenty patients, within 60 minutes of cardiopulmonary bypass time[group A] were compared with twenty patients, from 60 to 120 minutes of cardiopulmonary bypass time[group B]. Using blood cardioplegia for myocardial protection, Author observed wide variation of A.C.T. in individual response to initial heparinization[2mg /kg] and no requirement of additional heparin during cardiopulmonary bypass until 120 minutes. Total heparin amount during cardiopulmonary bypass was not related to body weight and body surface area in the both groups. After cardiopulmonary bypass, amounts of protamine for neutralization of heparin were more required in group B.

• Journal of Microbiology and Biotechnology
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• v.6 no.5
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• pp.315-320
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• 1996

The role of glyoxylate bypass in a lysine-producing Corynebacterium lactofermentum strain was analyzed. Unlike the wild type, the strain expressed enzymes of glyoxylate bypass during growth in the fermentation broth containing glucose as the carbon source. To evaluate the importance of glyoxylate bypass in the strain, we disrupted chromosomal aceA by using a cloned fragment of the gene. Site-specific disruption of aceA which codes for the isocitrate lyase, the first enzyme of the bypass, was confirmed by Southern blot analysis. The aceA mutant strain completely lost isocitrate lyase activity and ability to grow in a minimal medium containing acetate as the sole carbon source. The mutant strain was similar to its parental strain in growth characteristics and produced comparable amounts of lysine in shake flasks containing glucose as the carbon source. The amount of oxaloacetate accumulated in the fermentation medium was similar for both strains, suggesting that expression of glyoxylate bypass does not necessarily lead to the increase in intracellular oxaloacetate. These data clearly demonstrate that glyoxylate bypass does not function as one of the routes of carbon supply for lysine production in the strain. It appears that the leakiness of the glyoxylate bypass in the strain might be the result of a secondary mutation which arose during previous strain development by random mutagenesis.

• Journal of Chest Surgery
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• v.28 no.7
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• pp.678-683
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• 1995

Arterial bypass for the chronic ischemia of the lower extremities underlying atherosclerotic obliterans has been performed with a number of alternative conduits from 1941 by Kunlin. It is indicated for the limb salvage of patients with threatened limb loss despite of several controversies in surgical treatment of atherosclerotic obliterans. From March 1991 to January 1995, 26 arterial bypasses were performed in 23 patients with the chronic ischemia of the lower extremities in our hospital. Their mean follow up period is 18.9 months ranging from 4 months to 44 months. Mean age is 60.9 years ranging 47 years to 76 years and the most prevalent incidence is the 6th decade. 21 patients are male and 2 patients are female. 19 of 23 patients are smokers. Clinical classifications by Fontaine are class II[21.7% , class III[34.8% and class IV[43.5% .Diabetes mellitus[47.8% , hypertension[43.5% , hyperlipid-emia[26% , tuberculosis[21.7% , cerebrovascular accident[13.0% and cardiac diseases[8.7% are associated. Aorto-single femoral bypass in 4 cases, aorto-bifemoral bypass in 5 cases, aortofemoral & femoropopliteal bypass in 2 cases, femoropopliteal bypass in 10 cases, popliteotibial bypass in 3 cases, femoropedal bypass[composite graft bypass in 2 cases were surgically approached. There are complicated early thrombosis in 4 cases those are required immediately reoperation, wound infection in 3 cases, hematoma in 3 cases, and so on. Postoperative complication rate is 53.8%.Postoperative patency rates are 84.6% at 6 months, 75.0% at 1 year, 70.0% at 2 years and 66.7% at 3 years. We usually used 6 mm & 8 mm graft for bypass, and the rate of thrombosis formation is 28.6%[2/7 in 6 mm graft and 12.5%[2/16 in 8 mm separately. In according to the graft materials, the rate of thrombosis formation is higher in the group using artificial graft than in that using autologous saphenous vein[16.6% vs 12.5% . Limb salvage rate is 76.9%. Postoperative mortality rate is zero %.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.1
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• pp.1-7
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• 2019

In this paper, a design technique using a bypass capacitor is proposed to improve the antenna efficiency of an inverted-F antenna (IFA) with a band stop matching circuit (BSMC). The proposed antenna operates in the LTE bands 26 and 5(814~ 894 MHz). The bandwidth of the IFA is expanded from 803~863 MHz to 800~888 MHz using the impedance change caused by the BSMC. To enhance the antenna efficiency in the expanded frequency band, the bypass capacitor is applied to the IFA with the BSMC. The bypass capacitor improves the efficiency of the antenna by reducing the current variation of the IFA with the BSMC. The proposed antenna has a bandwidth of 804~895 MHz and the antenna efficiency increases by more than 10 % in the extended frequency band by using the bypass capacitor.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.1
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• pp.11-19
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• 2001

To establish optimum cycle of the inverter-driven heat pump with a variation of frequency, the bypass orifice, which was a short tube haying a bypass hole in the middle, was designed and tested. Flow characteristics of the bypass orifice were measured as a function of orifice geometry and operating conditions. Flow trends with respect to frequency were compared with those of short tube orifices and capillary tubes. Generally, the bypass orifice showed the best flow trends among them. and it would enhance the seasonal energy efficiency ratio of an inverter heat pump system, Based on experimental data, a semi-empirical flow model was developed to predict mass flow rate through bypass orifices. The maximum difference between measured data and model`s prediction was within $\pm$5%.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.385-390
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• 2000

In this study we propose the computational model for the coronary circulation. The bypass from left ventricle is also considered. Lumped parameter model with three compartments in the coronary circulation is implemented in this study. We connected the coronary artery compartment with left ventricle to explain the bypass procedure from left ventricle. The asymmetric resistance is assumed in the bypass line from left ventricle. The present numerical method is tested for normal coronary circulation and the results are compared with the existing computational work. The bypass simulation is conducted and the flow pattern is delineated. The effect of shunt resistance and coronary compliance to circulation is investigated for the better design of the bypass shunt.

• Journal of Chest Surgery
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• v.26 no.11
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• pp.881-885
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• 1993

In the last few years there has been a resurgenceof interest in in-situ saphenous vein arterial bypass for lower extremity revascularization because of improved patency rates. we performed 1 in situ bypass oreration using the intraluminal valve-disruption tecnique. A 65-year-old female who had ztherosclerotic obstruction in the superficial and popliteal arteries underwent in situ saphenous vein arterial bypass. After harvesting of saphenous vein, we used LeMaitre retrograde valvulotome for valve-disruption technique. Completion of the arterrigraphy was performed to evaluate bothh the anastomoses. The two side brances were all ligated. In situ saphenous vein arterial bypass has become the procedure of choice for distal reconstruction in severely ischemic lower extremities because of improved long-term patency compared with reversed-saphenous vein bypass procedure.