• Title/Summary/Keyword: Cooling patch

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Effect of cooling patches on performance of photovoltaic-thermoelectric hybrid energy devices (쿨링패치 부착에 따른 태양광-열전 융합소자의 성능 연구)

  • Lee, Jaehwan;Cho, Kyoungah;Park, Yoonbeom;Kim, Sangsig
    • Journal of IKEEE
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    • v.25 no.4
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    • pp.716-720
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    • 2021
  • In this study, we examine the availability of a cooling patch to enhance the output power of a hybrid energy device (HED) comprising a photovoltaic cell (PVC) and a thermoelectric generator (TEG). The cooling patch attached on the back of the TEG drops the temperature of the PVC via the TEG and makes a large thermal gradient across the TEG under irradiances in a range of 200 to 1000 W/m2. The cooling patch is more effective for the output power of the HED as the irradiance increases, and it enhances the maximum output power of the HED to 42.1 mW at an irradiance of 1000 W/m2. The increment in the maximum output power reaches 27% owing to the attachment of the cooling patch that does not consume any power.

The impact of ram pressure on the multi-phase ISM probed by the TIGRESS simulation

  • Choi, Woorak;Kim, Chang-Goo;Chung, Aeree
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.62.1-62.1
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    • 2018
  • Galaxies in the cluster environment interact with the intracluster medium (ICM), losing the interstellar medium (ISM) and alternating their evolution. Observational evidences of the extraplanar ISM stripped by the ICM's ram pressure are prevalent in HI imaging studies of cluster galaxies. However, current theoretical understanding of the ram pressure stripping (or ICM-ISM interaction in general) is still limited mainly due to the lack of numerical resolution at ISM scales in large-scale simulations. Especially, self-consistent modeling of the turbulent, multiphase ISM is critical to understand star formation in galaxies interacting with the ICM. To achieve this goal, we utilize the TIGRESS simulation suite, simulating a local patch of galactic disks with high resolution to resolve key physical processes in the ISM, including cooling/heating, self-gravity, MHD, star formation, and supernova feedback. We then expose the ISM disk to ICM flows and investigate the evolution of star formation rate and the properties of the ISM. By exploring ICM parameter space, we discuss an implication of the simple ram pressure stripping condition (so called the Gunn-Gott condition) to the realistic ISM.

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A literatual study on the causes and treatments of the melasma. (기미에 關한 文獻的 考察)

  • Shin, Yun-sang;Roh, Sek-seon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.11 no.1
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    • pp.82-98
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    • 1998
  • In the literatual studies on the causes and treatments of the melasma, the results were as follows. 1. Melasma is the blackish patch on the face, is belong to the cartegory of the 'Myunjin(面塵)', 'Myunganzung(면간증)', 'Jakban(雀斑)' etc. in Oriental medicine 2. Melasma is deeply associated with Yangming channel in Meridian, with the spleen, stomach, heart and kidney in Viscera. 3. The pathogenic factors of Melasma is divided five parts. One is insufficient of Yangming's energy in Neijing(內經). Two is incoordination between vital energy and blood caused by wind-evil and phlegm-retention syndrome. Three is anxiety impairing the spleen. Four is kidney-asthenia and fire-hyperactivity. Five is heat-evil. 4. In the treatments of Melasma, Sthenia-syndrome was used cooling blood and activating blood circulation, or dispelling wind-evil and promoting meridian, or expelling fire-evil and removing toxic material etc. Asthenia-syndrome was used invigorating the liver and kidney, or nourishing yin and keeping fire downwards etc. 5. Melasma is concerned with sun-light, is mostly seen in female. 6. In the prescription of Melasma, it was used Jujesamultang(酒製四物湯加減), Okyong -san(玉容散), Chunghwasungitang(沖和順氣湯), Okyongseosisan(玉容西施散), Yukmiji-hwanghwan(六味地黃丸) etc.

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Modeling and analysis of selected organization for economic cooperation and development PKL-3 station blackout experiments using TRACE

  • Mukin, Roman;Clifford, Ivor;Zerkak, Omar;Ferroukhi, Hakim
    • Nuclear Engineering and Technology
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    • v.50 no.3
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    • pp.356-367
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    • 2018
  • A series of tests dedicated to station blackout (SBO) accident scenarios have been recently performed at the $Prim{\ddot{a}}rkreislauf-Versuchsanlage$ (primary coolant loop test facility; PKL) facility in the framework of the OECD/NEA PKL-3 project. These investigations address current safety issues related to beyond design basis accident transients with significant core heat up. This work presents a detailed analysis using the best estimate thermal-hydraulic code TRACE (v5.0 Patch4) of different SBO scenarios conducted at the PKL facility; failures of high- and low-pressure safety injection systems together with steam generator (SG) feedwater supply are considered, thus calling for adequate accident management actions and timely implementation of alternative emergency cooling procedures to prevent core meltdown. The presented analysis evaluates the capability of the applied TRACE model of the PKL facility to correctly capture the sequences of events in the different SBO scenarios, namely the SBO tests H2.1, H2.2 run 1 and H2.2 run 2, including symmetric or asymmetric secondary side depressurization, primary side depressurization, accumulator (ACC) injection in the cold legs and secondary side feeding with mobile pump and/or primary side emergency core coolant injection from the fuel pool cooling pump. This study is focused specifically on the prediction of the core exit temperature, which drives the execution of the most relevant accident management actions. This work presents, in particular, the key improvements made to the TRACE model that helped to improve the code predictions, including the modeling of dynamical heat losses, the nodalization of SGs' heat exchanger tubes and the ACCs. Another relevant aspect of this work is to evaluate how well the model simulations of the three different scenarios qualitatively and quantitatively capture the trends and results exhibited by the actual experiments. For instance, how the number of SGs considered for secondary side depressurization affects the heat transfer from primary side; how the discharge capacity of the pressurizer relief valve affects the dynamics of the transient; how ACC initial pressure and nitrogen release affect the grace time between ACC injection and subsequent core heat up; and how well the alternative feeding modes of the secondary and/or primary side with mobile injection pumps affect core quenching and ensure stable long-term core cooling under controlled boiling conditions.

Experimental cardiac transplantation in the mongrel dogs (II) (한국산 잡견에서의 실험적 심장 이식술 (II))

  • 이정렬
    • Journal of Chest Surgery
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    • v.23 no.5
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    • pp.844-853
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    • 1990
  • We have performed 27 cases of orthotopic homologous cardiac transplantation using Korean mongrel dogs and one case of sham operation for the evaluation of harmful effect of cardiopulmonary bypass itself on the dog from April, 1989 to June, 1990. Our previous reports have already demonstrated basal hemodynamic and hematologic data on the canine homologous heart transplantation and the fundamental principles of transplantation of the heart. The mean body weight of recipients was 13.2$\pm$1.2kg with a rage of 11 ~ 15kg, and the hemodynamic and hematologic pictures were almost same as the result of previous reports from our hospital, except marked decrease in postoperative platelet count[from 3.18 $\pm$0.80x106/mm3 to 1.41$\pm$0 37x 106/mm3]. Mean survival time was 24.82$\pm$49.40 hours with the longest survival of 264 hours. Donor cardiectomy included coronary vasodilatation with diltiazem, potassium arrest, and the rapid cooling of the heart suspending in the specially designed ice-bath. Median sternotomy provided excellent exposure of the surgical field. 6 \ulcorner0 prolene suture was used for the anastomosis of both atrial cuffs and the great arteries, and we found the fact that stenosis, bleeding, thrombus formation around the anastomotic site could be decreased with the use of everted horizontal mattress suture techniques. Immunosuppression was done with a combination of lower dose Cyclosporin-A, Azathioprine, methyl-prednisolone, but our cases still showed too short survival to worry about graft rejection. Still poor was our quality control of experimental animal, we had much difficulties in postmortem evaluation of the dogs. Low cardiac output due to biventricular failure, intractable supraventricular or ventricular tachyarrhythmia, postoperative massive bleeding, sepsis were most frequent findings that could be thought as a cause of death. A few cases showed subendocardial patch hemorrhage in both ventricular cavity or atrial septum at autopsy, suggesting acute subendocardial infarction. Although our team overcome most of the technical problems of orthotopic heart transplantation, we should pile up further knowledges about donor heart preservation, quality control of animal, infection, rejection, the effect of the cardiopulmonary bypass to improve the results.

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Open Heart Surgery for Six Cases of the Conegnital Heart Disease (선천성(先天性) 심장병(心臟病)의 개심술(開心術) -6례(例) 수술경험(手術經驗) -)

  • Lee, Sung Haing;Lee, Sung Koo;Han, Sung Sae;Lee, Kihl Rho;Kim, Song Myung;Lee, Kwang Sook;Lee, Chong Kook
    • Journal of Chest Surgery
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    • v.9 no.2
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    • pp.220-238
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    • 1976
  • Six cases of congenital heart disease were operated on by means of cardiopulmonary bypass between December, 1975 and April, 1976. Two cases of ventricular septal defects (VSD), two cases of VSD, associated with ruptured aneurysm of sinus Valsalva, two cases of atrial septal defects (ASD) and one case of pulmonic stenosis with patent ductus arteriosus were operated. Sarns roller pumps and Bentley Temptrol oxygenators were used for extracorporeal circulation. Pump oxygenator was primed with Ringer's lactate solution, 5% dextrose in water, mannitol, and ACD blood. Flow rate ranged from 2.0 to $2.4L/M^2/min$. Bicarbonate was added to the oxygenator with estimated amount as 15 mEq/L/hr. Venous catheters were introduced into superior and inferior vena cava, and oxygenated blood was returned to the body through aortic cannula inserted into ascending aorta. Moderate hypothermia ($30^{\circ}C$) was induced by core cooling. Aorta was cross clamped for 15 minutes and released for 3 minutes, and repeated clamping when necessary. Atrial and ventricular septal efects were closed by direct sutures. Aneurysms of sinus Valsalva ruptured into the right ventricle were repaired through right ventriculotomy by d:rect closure with Dacron patch reinforcement. Cardiopulmonary bypass time varied from 66 to 209 minutes, and aorta cross clamping time ranged from 13 to 56 minutes. Postoperative bleeding was minimal except one case who needed for evacuation of substernal hematoma. Intra- and postoperative urinary output was satisfactory. Acid-base balance, partial pressure of $O_2$, electrolytes, and hematological changes during intra- and post-perfusion period remained at the acceptable ranges. No mortality was experienced.

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