• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.1
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• pp.97-102
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• 2012

A hermetically sealed oil transformer is designed by applying expanding function of the tank due to the volume changes of the insulation oil according to the temperature rises. When the insulation oil expands, an increase in the volume of the corrugated fin prevents a pressure rise of the transformer. For a wind turbine transformer, a vegetable-oil-immersed transformer has the advantages of excellent biodegradation and fire-resistant properties like an exceptionally high fire point. When vegetable oil is substituted for mineral oil, however, the maximum winding temperature rises because of the decrease in the internal circulation flow rate resulting from the variations of the oil's physical characteristics, such as density and viscosity. The purpose of this study is to develop a hermetically sealed vegetable oil transformer that can be applied in a wind turbine and to analyze the thermal stability of the active part of the transformer to deal with pressure variations due to the temperature changes. In addition, thermal tests for the vegetable oil transformer have been performed, and the measured values are compared with the analysis results.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.89-92
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• 1993

In this article, we present and analyze the results of the three consecutive in vivo experiments of the LVAD to evaluate the function of the LVAD and the adverse effects on living animals. We applied the LVAD consecutively to three mongrel dogs and the circulation of the blood was assisted under the anesthesia. We used in general both the asynchronous mode and the synchronous mode to drive the LVAD. During the experiments we monitored the dogs with a polygraph to evaluate the function of the LVAD and the additional effects on the natural hearts. We also examined several clinical pathologic tests in order to see the effects of the LVAD to the red blood cells and the other internal organs. The dogs survived for two to there days. The LVAD assisted the circulatory system at the maximum assist flow rate of 3.0 1/min. Although the red blood cells of the dogs had mechanical damages by the LVAD to result in the hemolysis, the degree of the hemolysis was not so high and the damages caused by the hemolysis on the dogs were not serious. The myocardium of the first dog was gradually worsened and eventually failed. The damage of the myocardium was due to the asynchronous driving mode of the LVAD. The other organs did not have serious damages due to the application of the LVAD. The main purpose of this paper is to evaluate the results of the in vivo experiments of the LVAD and to find better ways to the application of the LVAD to human beings.

• The Korean Journal of Pain
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• v.34 no.4
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• pp.427-436
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• 2021

Background: Pharmacological and non-pharmacological therapies have been used to treat patients with chemotherapy-induced peripheral neuropathy (CIPN). However, the effect of therapies in cancer patients has yet to be investigated comprehensively. We hypothesized that cyclic thermal therapy would improve blood flow and microcirculation and improve the symptoms driven by CIPN. Methods: The criteria of assessment were blood volume in region of interest (ROI) in the images, and European Organization for Research and Treatment of Cancer-Quality of Life Questionnaire-Chemotherapy-Induced Peripheral Neuropathy 20 questionnaire scores. The blood volume was quantified by using red blood cell (RBC) scintigraphy. All patients were treated 10 times during 10 days. The thermal stimulations, between 15° and 41°, were repeatedly delivered to the patient's hands. Results: The total score of the questionnaires, the score of questions related to the upper limbs, the score of questions closely related to the upper limbs, and the score excluding the upper limbs questions was decreased. The blood volume was decreased, and the variance of blood volume was decreased. During cooling stimulation, the blood volume was decreased, and its variance was decreased. During warming stimulation, the blood volume was decreased, and its variance was decreased. Conclusions: We suggest that cyclic thermal therapy is useful to alleviate CIPN symptoms by blood circulation improvement. RBC scintigraphy can provide the quantitative information on blood volume under certain conditions such as stress, as well as rest, in peripheral tissue.