• Journal of Chest Surgery
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• v.23 no.6
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• pp.1263-1269
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• 1990

Two patients with uncorrectable cyanotic cardiac anomalies underwent total cavopulmonary shunt[modified Fontan operation]. Case I was a 14 years old male with dyspnea and cyanosis after birth. Aortogram showed TGA combined with overriding of aorta, pulmonary stenosis, complete atrioventricular septal defect, interruption of inferior vena cava, and situs inversus totalis. We had performed total cavopulmonary shunt using with 16 mm Gortex Graft in single atrium to bypass the hepatic vein to pulmonary artery. Postoperatively, patient sustained low PaCO2 and low cardiac output and then expired at 19th postoperative day. The cause of death of the patient would be low cardiac output. Case II was a 6 years old female with dyspnea and cyanosis after birth. Aortogram showed tricuspid atresia[Type IIb], transposition of great arteries, atrial septal defect, ventricular septal defect and pulmonary stenosis, We had performed total cavo-pulmonary shunt using intraatrial baffle[tunnel] with Goretex patch. The postoperative course of this patient was good without event.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.7
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• pp.979-982
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• 2003

Two rapeseed meal samples (Sample A, hybrid 5900 and sample B, double low rapeseed No.4) obtained from China and one Canola meal sample obtained from a local crushing plant in Canada were used to investigate the amino acid degradability of rapeseed/Canola meal in rumen and amino acid digestibility of ruminal incubation residues by precision-fed rooster bioassay. Results show that in ruminal incubation the degradation rate of non amino acid nitrogen in crude protein is higher than that for amino acid nitrogen in crude protein, the results also suggest that the degradation rate of amino acid nitrogen in Chinese rapeseed meal sample B was lower than that for Canadian Canola, but that in Chinese rapeseed meal sample A is much close to that for Canadian canola meal. For all amino acids the digestibility of the bypass or residual protein as measured by the precision-fed rooster bioassay tended to be lower for Chinese rapeseed meal sample A than for sample B or Canadian canola meal which had similar digestibility values. However following a calculation of total amino acid availability, involving the digestibility of amino acids in the rumen and rooster bioassay the results are less contradictory. Results indicated that in traditional roasting-expelling process, heat treatment, especially dry heat treatmeat could decrease amino acids degradability in rumen of rapeseed/canola meal, but also may decrease total availability of amino acids of rapeseed/canola meal.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.4
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• pp.631-640
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• 2016

A dual-mode power management for a hybrid-electric UAV with a cruise power of 200W is proposed and empirically verified. The subject vehicle is a low-speed long-endurance UAV powered by a solar cell, a fuel cell, and a battery pack, which operate in the same voltage bounds. These power sources of different operational characteristics can be managed in two different methods: passive management and active management. This study proposes a new power management system named PMS2, which employs a bypass circuit to control the individual power sources. The PMS2 normally operates in active mode, and the bypass circuit converts the system into passive mode when necessary. The output characteristics of the hybrid system with the PMS2 are investigated under simulated failures in the power sources and the conversion of the power management methods. The investigation also provides quantitative comparisons of efficiencies of the system under the two distinct power management modes. In the case of the solar cell, the efficiency difference between the active and the passive management is shown to be 0.34% when the SOC of the battery is between 25-65%. However, if the SOC is out of this given range, i.e. when the SOC is at 90%, using active management displays an improved efficiency of 6.9%. In the case of the fuel cell, the efficiency of 55% is shown for both active and passive managements, indicating negligible differences.

• 한국태양에너지학회:학술대회논문집
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• 2008.04a
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• pp.257-262
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• 2008

In this paper, we study the electric characteristics of shading effects in photovoltaic module in case of outdoor operation. When fabricating PV module, solar cells are connected serially to obtain the high voltage because of its low open circuit voltage. And total current is determined by lowest current among solar cells. When the shading happens on PV module's surface, the current of shaded solar cell determine the total current flow. Because of this, generally by-pass diode is installed on junction box. The bypass diode operate when revered and shaded solar cell's voltage is over 0.6 voltage. The reverse-biased solar cell gives reduced maximum power of PV module and might give negative effect on durability. So, adequate by-pass installation and selection is needed.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.353-358
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• 2001

Turbo-charging or Super-charging has been used to boost engine power for Gasoline Engine and Diesel Engine came to the world at the beginning of $20^{th}$ century. So far Turbo-Charger has enjoyed a high reputation in the charging filed for its technical advantages such as no demand of operation power from engine and an excellent charging effect in the event of a static operation at mid- and high engine speed. A mechanically driven Super-Charger, however, is now emerging in order to meet demands of the age of speed such as high engine power for a quick change of the driving mode - high engine torque even at low engine speed. Since Super-Charger needs driving power from engine, it cannot improve its relatively higher fuel consumption against that of Turbo-Charger. This negative point is still an obstacle to the wide use of Super-Charger. Super-Charger using Screw-type compressor which has already had a considerable base in air compressor market will fulfill this purpose of improving fuel consumption by minimizing operation power owing to no charging at idling or partially loading driving. This study aims to develop power control concept to achieve this minimization of operation power.

• Journal of Chest Surgery
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• v.28 no.10
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• pp.885-891
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• 1995

In order to test the hypothesis that the pulmonic valve, when used to replace the aortic root as a pulmonary autograft, will remain a viable anatomical structure and will grow and develop normally along with the host, we performed aortic valve replacement with the pulmonary autograft in 15 neonatal piglets. The weight of the donor was 9.3 $\pm$ 0.2 kg, the recipient 9.6 $\pm$ 0.3 kg. Measured diameters of pulmonic annulus were 14 $\pm$ 0.2 mm for autograft and 14.2 $\pm$ 0.2 mm for pulmonary artery homograft. Operation was performed under cardiopulmonary bypass with deep hypothermia [20oC at low flow perfusion [70 ml/kg/min . The mean operation time was 227 $\pm$ 10 min., bypass time 152$\pm$ 7.6 min. and aortic cross clamp time 73$\pm$ 4.6 min.. 9 piglets survived more than 12 hours. One survived 12 days and died of pneumonia and the latest one survived in good condition and sacrificed at postoperative 6th week for cardiac catheterization and pathologic examination that revealed the viability and growing of the pulmonary autograft. Currently we are able to complete the operation with good preservation of cardiac function, and our postoperative care has evolved to the extent that we are now confident enough of having an acceptable percentage of long term survivors to undertake a definite study in this regard.

• Journal of Chest Surgery
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• v.26 no.7
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• pp.526-531
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• 1993

Sixty-one consecutive patients with coronary artery bypass graft for myocardial revascularization were retrospectively reviewed to analyze various pattern of postoperative complication and death during hospital stay from Nov. 1988 to Oct. 1992. Fortytwo of the patients were male and nineteen female. The mean age was 56 and 51 years in male and female. Preoperative diagnosises were unstable angina in 14 of patients, stable angina in 28, postmyocardial infarction state in 15, and state of failed percutaneous transluminal coronary angioplasty in 4. 141 stenosed coronary arteries were bypassed with use of 20 pedicled internal mammary artery and 124 reversed saphenous vein grafts. Postoperative complications and perioperative death were as follows: 1. Of 61 patients undergoing operation, peri and postoperative over all complication occured in 15 patients [ 25% ]; newly developed myocardial infarction in 4, intractable cardiac arrhythmia including atrial fibrillation and frequent ventricular premature contraction in 3, bleeding from gastrointestinal tract in 2, persistent vegetative state as a sequele of brain hypoxia in 1, wound necrosis in 1, left hemidiaphragmatic palsy in 3 and poor blood flow through graft in 2. 2. Operative mortality was 8%[5 patients]. 3 out of these died in operating room; 1 patient by bleeding from rupture of calcified aortic wall, 1 by air embolism through left atrial vent catheter, 1 by low cardiac output syndrome. 2 patients died during hospital stay; 1 by acute respiratory distress syndrome with multiuple organ failure, 1 by brain death after delayed diagnosis of pericardial tamponade.

• Journal of Chest Surgery
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• v.15 no.4
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• pp.402-408
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• 1982

The primary cardiac tumor was considered as a form of disease with poor prognosis in the past and it was hardly diagnosed before post mortem autopsy. But recent development of diagnostic procedure and the cardiac surgery using extracorporeal circulation increased the accuracy of diagnosis and the opportunity of successful treatment. The authors present two cases of left atrial myxoma which experienced during recent 4 years between 1979 and 1982. A 33 year old woman admitted with severe shortness of breath, generalized edema, ascites and the evidence of hepatopathy resulted from right sided heart failure. Preoperatively, the patient was treated with conservative medication to improve general condition for a few days. The tumor mass was removed successfully under the cardiopulmonary bypass. She, however, died of myocardial dysfunction showing low blood pressure. The tumor mass weighed 22gm and measured 5.2x4.5x3.6 cm in size. A 60 year old man admitted with shortness of breath on exertion and an episode of fainting. Following the removal of tumor mass under the cardiovascular bypass, the clinical course was satisfactory with no complication. The tumor mass weighed 105gm and measured 9x4x5 cm in size.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.5
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• pp.606-612
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• 2012

A highly efficient multi-mode balanced power amplifier(PA) structure is proposed for W-CDMA handset applications. The proposed PA has 2-stage amplifier configuration and the stage-bypass and load impedance switching techniques were applied to enhance power efficiency at medium power level as well as low output power level. Using the two techniques, four highly efficient power modes were realized. To demonstrate the usefulness of the proposed structure, a GaAs HBT balanced PA module was designed, fabricated, and measured.

• Journal of Chest Surgery
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• v.25 no.5
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• pp.458-468
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• 1992

With the aid of extracorporeal circulation, nine dogs underwent orthotopic cardiopulmonary transplantation after preservation of the donor heart in a hypothermic amino acid[glutamate, aspartate] enriched high potassium extracellular solution, and preservation of the donor lung with hypothermic low potassium dextran solution from June 1990 to May 1991. The mean body weights of dogs were 20kg and the recipients` preoperative hematologic and hemodynamic pictures were within normal range except slightly decreased level of albumin and total protein, which was supposed to be due to malnutrition. The following modifications of the original Stanford technique were emphasized: [1] the posterior mediastinum is dissected as little as possible with meticulous hemostasis; [2] the surgical procedure is kept away from the phrenic and vagus nerves; [3] the tracheal anastomosis may be wrapped with recipient`s pulmonary artery flap or surrouding soft tissues. A combination of Cyclosporine, Azathioprine, corticosteroid was used as perioperative immunosuppressive therapy. Postoperatively all recipients could be weaned from extracorporeal circulation, showing favorable vital signs, but within 24 hours, irreversible congetive heart failure, ascites, arrhythmias developed with a mean survival time 13.6$\pm$6.6[n=9, range=6~26] hours. Hemoglobin and platelet counts were significantly[p<0.05] decreased postoperatively, which is thought to be attributed to blood damage by cardiopulmonary bypass and hemodilution. Postmortem finding included multiple subendocardial patch hemorrhage in both atrial and ventricular cavities, pulmonary and liver congestion, and all tracheal anastomoses were intact. Further consideration about quality control of the animal, infection, rejection, the effect of cardiopulmonary bypass on the experimental animal is required to improve the results.