• 제목/요약/키워드: Stagnation

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상변화 물질을 이용한 전자 장비 방열 설계의 수치 해석적 연구 (Numerical Analysis for Thermal Design of Electronic Equipment Using Phase Change Material)

  • 이동균;이원희;박성우;강성욱;조지현
    • 대한기계학회논문집B
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    • 제41권4호
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    • pp.285-291
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    • 2017
  • 본 연구에서는 무인 항공 장비에 장착되는 전자 장비에 상변화 물질을 적용한 방열 설계를 수치적으로 진행하였다. 상변화 물질에 대한 열특성 실험을 통해 용융점($T_m$), 용융시 온도 증분(${\Delta}T_m$) 및 체적 팽창을 확인하였으며, 이를 통해 해석 모델 검증을 진행하였다. 용융시 용융점에서 발생하는 온도 정체 현상을 모사하기 위해 등가 비열법으로 계산한 열 물성치를 상변화 물질의 해석 모델 물성치로 입력하였으며, 실험 결과와의 비교를 통해 해석 모델의 신뢰성을 검증하였다. 검증된 해석 모델을 통해 핀과 함께 상변화 물질이 충진된 장비 하우징의 방열 성능을 향상시키고, 이를 통해 장비의 열적 안정성을 확보하였다. 현재 상변화 물질이 충진된 하우징의 방열 성능 극대화를 위해 핀 최적 설계에 대한 추가적인 연구가 진행 중에 있다.

폰탄 수술에서 문합방법에 따른 혈류 변화 (Blood Flow Changes by Anastomotic Method in Fontan Operation)

  • 김상현;박영환;조범구;김종훈;홍유선;김영호;김승수
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1996년도 춘계학술대회
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    • pp.203-206
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    • 1996
  • To understand the local fluid dynamics for different desists of Fontan operation, five models were made out of Pyrex glass to facilitate in-vitro study. Model I, II and III have same position of the center of the anastomosis of the IVC( inferior vena cava) with that of the SVC(superior vena cava), but Model IV and V have 10 mm offset between them. Also the anastomotic junction angles are different(Model I and $IV:90^{\circ}$, Model II and $V:70^{\circ}$, Model $III:45^{\circ}$). These models were then connected to a flow loop for flow visualization study. In Model I any dominant vortex was not seen in the central region of the juntion, but a large unstable vortex was created in the Model II and III. In Model IV and V a significant stagnation region was created in the middle of the offset region. It also showed that the flow direction from the IVC and SVC to the LPA(left pulmonary artery) and RPA(right pulmonary artery) highly depends on the offset of the junction rather than the anastomotic junction angle.

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대상포진에 대한 한방 단독 치료 치험 2례 (Two Cases Report of Herpes Zoster Patients Improved by Korean Medicine Treatment alone)

  • 배재룡;김수진;장상철;필감매;노주희
    • 대한의료기공학회지
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    • 제16권1호
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    • pp.116-136
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    • 2016
  • Objectives : The purpose of this study is to report a 67-year-old male patient with Herpes zoster(caseI) and a 38-year-old female patient with Herpes zoster(caseII), whose symptoms were relieved after Korean medicine treatment alone. Methods : Both patients took Yeonryeonggobondan and Pyungwee-san daily. Everytime they came to the hospital, they received acupuncture treatment, Hwidam's Su-Gi therapy and External Gigong Therapy. Acupuncture was applied by gall bladder seunggyeok(膽勝格, GB-), spleen jeonggyeok(脾正格, SP+), large intestine seunggyeok(大腸勝格, LI-) of Saam's Acupuncture Method. Hwidam's Su-Gi therapy was applied on neck. External Gigong Therapy was applied on skin lesion area. the patients' symptoms were evaluated with photographs and VAS. Results : The results were as follows: 1. In the case of a 67-year-old male patient, it took 14 days to recover the skin lesions and to reduce the pain after treatment started. And he visited 13 times during that period. 2. In the case of a 38-year-old female patient, it took 23 days to recover the skin lesions to reduce and the pain after treatment started. And she visited 10 times during that period. 3. Intensive treatment early in treating herpes zoster helped to shorten the treatment period. 4. Taking Yeonryeonggobondan and Pyungwee-san and receiving acupuncture treatment(SP+) can help to improve immunity and recover skin lesions in herpes zoster diagnosed with spleen deficiency with dampness encumbrance(脾虛濕困) and blood stasis due to qi stagnation (氣滯血瘀). 5. The combination of acupuncture treatment(GB-) and External Gigong Therapy was effective in controlling pain. 6. External Gigong Therapy is considered to be effective for the recovery of the skin as well as the pain of the herpes zoster. Conclusions : Korean medicine treatment alone has a great effect on the above two patients with herpes zoster. I hope the active research about Korean medicine treatment will be done not only for herpes zoster but also for various intractable pain diseases.

자궁근종의 치료에 대한 고찰 -2010년 중국내 발표 논문 중심으로- (The Study on the Treatment of Leiomyoma - Focusing on the Papers Published in 2010 within China -)

  • 백영주;김명동
    • 대한한방부인과학회지
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    • 제24권1호
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    • pp.109-131
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    • 2011
  • Objectives: This study aims to search the clinical cases that treated leiomyoma through the traditional Chinese medicine, to understand the study trend on leiomyoma in China, and to clairfy the cause of leiomyoma and its treatment by the oriental medicine herbs. Methods: We searched the key word "leiomyoma" in the China National Knowledge Infrastructure (CNKI)[http://www.cnki.net], and narrowed its searching area to the papers published in the year 2010. Of 720 study papers, we chose 21 clinical papers on the leiomyoma, and studied the patient case, treating method, result of treatment, and checked the category, cause, treatment method of leiomyoma. Results: The results are shown in the Table 1-3. Conclusions: Leiomyoma is categorized in the traditional Chinese medicine as both lump occuring inside the body and stony abdominal lump. The main cause of leiomyoma is qi-stagnation and blood stasis, essence deficiency and pathogen affluence. The treatment method is used by activating blood and resolving stasis but harmonizing the spleen and stomach to prevent damaging healthy qi. The development herbal medicine of treating leiomyoma is Gyehongbyeolgaphwan, Gyejibongnyeonggyonang, Gungryusogyonang, Angonpyoen etc. In treating leiomyoma, the herbs were much used to regulate qi as Baekbokryung, Danggwi, Baekchul, Doin, Moryeo, Achul, Mokdanpi etc. Traditional Chinese Medicine(TCM) treatment of leiomyoma has efficiency of improve symptom but low ratio of complete recovery.

체계적 문헌고찰과 델파이 기법을 활용한 갱년기장애 변증(辨證)진단 도구 개발을 위한 기초 연구 (Development of a Guideline for the Application of a Diagnostic Tool for Menopausal Syndromes Based on the Use of Systemic Review and Delphi Method)

  • 이인선;김동일;유정은;강창완
    • 대한한방부인과학회지
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    • 제30권4호
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    • pp.175-202
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    • 2017
  • Objectives: This study was conducted towards developing a screening tool for syndrome differentiation in the diagnosis of menopause in menopausal and perimenopausal women. Methods: We conducted a literature review of studies on menopausal diagnosis based on syndrome differentiation, and examined well-founded differentiated syndromes and their respective clinical symptoms. Based on the findings, we created a questionnaire through consultations with Oriental medicine experts in physiology, pathology, and diagnostics. Finally, the research team conducted an expert Delphi study on differentiated syndromes and the associated clinical symptoms. Results: Seven differentiated syndromes were selected, including Liver Depression (肝鬱), Kidney Yin Deficiency (腎陰虛), Kidney Yang Deficiency (腎陽虛), Liver and Kidney Yin Deficiency (肝腎陰虛), Kidney Yin and Yang Deficiency (腎陰陽兩虛), Heart-Kidney Noninteraction (心腎不交), and Dual Deficiency of Heart and Spleen (心脾兩虛); 4 disease locations, including liver (肝), heart (心), spleen (脾), and kidney (腎); and 3 disease natures, including Yin Deficiency (陰虛), Qi Stagnation (氣滯), and Blood Deficiency (血虛). In addition, we added 3 supplemental disease natures, including Yang Deficiency (陽虛), Qi Deficiency (氣虛), and Heat (火熱), in consideration of syndrome differentiation categories that may possibly be added in a follow-up clinical questionnaire. Conclusions: This resulted in a total of 7 differentiated syndromes, 4 disease locations, and 6 disease natures. We translated the clinical symptoms of these 17 categories into Korean Hangeul. After consulting with 5 Oriental medicine experts and a psychology expert, we produced a questionnaire for use in diagnosing menopause based on syndrome differentiation. The calculation of scores for the syndrome differentiation screening tool will be confirmed through clinical research based on the results of a review of existing literature.

심병증 진단요건의 표준 설정을 위한 연구 (Study on Establishment of criteria for Heart Disease in Oriental Medicine)

  • 최선미;박경모;정찬길;성현제;안규석
    • 동의생리병리학회지
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    • 제17권4호
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    • pp.845-851
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    • 2003
  • The objective is to establish the standard of criteria for differential diagnosis of signs and symptoms. This study selected signs and symptoms related to heart which stands for Fire(火) as a kind of five phase(五行). Eleven experts was asked to evaluate the adequateness of criteria which was developed by Korea Institute of Oriental Medicine(KIOM) and to suggest the amendment of them. To implement the study, we used the questionnaire which asks about the diagnosis criteria for an insufficiency of the heart-qi(心氣虛證), deficiency of the heart blood(心血氣證), deficiency of the heart-yin(心陰虛證), insufficiency of the heart-yang(心陽虛證), exuberant fire due to hyperactivity of the heart(心火亢盛證), stagnation of the heart blood(心血瘀阻證), heart disturbed by phlegm-fire(痰火擾心證), attack of the heart by retainedfluid(水氣凌心證). Every criteria consists of primary symptoms, secondary symptoms, tongue findings. and pulse findings. In perspectives of the classification of patterns for signs and symptoms and criteria for diagnosis, the result shows that the previous standard doesn't have so many problem. So many of experts were agree with the criteria which was suggested but the trend is that they use, in their actual practice, less than the criteria. Additionally, they pointed that every element in a criterion should have the different weight value, criteria for the overlapped pattern should be added, and, in future, criteria which are based on clinical investigation should be established.

"상한론"에 나타난 계(悸)와 관련된 처방들의 현대 질환 범위 고찰 (Study on Diseases Scope of Prescriptions Related with the Palpitation in "Shanghanlun")

  • 박미선;김영목
    • 동의생리병리학회지
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    • 제29권1호
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    • pp.1-10
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    • 2015
  • This article is a study on palpitation of which disease cause, disease mechanism and formulas were analyzed with reference to annotations on "Shanghanlun" and "Jinkuiyaolue". And the scope of modern diseases related with palpitation was drawn by research on clinical papers. The source books are "Zhujieshanghanlun" and "Jinkuiyaoluefanglun" and the clinical papers are searched in China Academic Journals(CAJ) of China National Knowledge Infrastructure(CNKI). 13 clauses in "Shanghanlun" and 9 clauses in "Jinkuiyaolue" and 12 formulas are related with palpitation. Disease mechanisms of palpitation were classified as yang deficiency, yin deficiency, qi deficiency, blood deficiency, retained fluid, cold, etc and these days, qi stagnation, phlegm turbidity, blood stasis and fire heat are also considered as disease mechanisms. Modern diseases related with palpitation are arrhythmia(extrasystole, atrial fibrillation, bradycardia, tachycardia, sick sinus syndrome, atrioventricular block), vascular diseases(arterial occlusion, phlebothrombosis, Buerger's disease, coronary artery disease, vasculitis), blood pressure disorder(hypertension, hypotension) and heart diseases such as heart failure, angina pectoris, myocardial infarction, myocarditis, cardiomyopathy, pericardial effusion. And diseases related with psychological change(cardiac neurosis, anxiety neurosis, neurosis, depression, hyperthyroidism, hypothyroidism), pyrexia, anemia, drug intoxication, etc are also related with palpitation. Zhen Wu Tang showing an efficacy in dilating blood vessels and strengthening cardiac function, Wuling Powder with diuretic effect and Fried Glycyrrhizae Decoction acting on the ${\beta}$ receptor are applied to heart failure in different ways. Fried Glycyrrhizae Decoction(308 cases), Zhen Wu Tang(154), Wuling Powder(54), Xiao Chaihu Tang(34), Sini San(20) are reported to have been clinically applied to cardiovascular diseases and Zhen Wu Tang and Wuling Powder mainly applied to heart failure, Fried Glycyrrhizae Decoction, Lizhong Wan, Sini San and Zhen Wu Tang chiefly applied to arrhythmia related diseases. This study focuses on the general research and consideration on clinical applications and is a preliminary study to understand relations between Korean Medicine's symptoms and categories of modern diseases.

혼합대류에 의한 구 주위의 충류유동 및 열전달 해석 (Analysis of mixed convective laminar flow and heat transfer about a sphere)

  • 이준식;김택영
    • 대한기계학회논문집
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    • 제11권2호
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    • pp.345-353
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    • 1987
  • 본 연구에서는 구 주위의 혼합대류에 대하여 전 영역에 걸쳐 유효한 매개변수 를 차원해석에 의해 유도하고 이를 적용하여 지배방정식을 비상사 경계층 방정식의 형 태로 변환하고 이를 유한차분법에 의해 수치적으로 해석하였다. 단순 강제대류에서 부터 단순 자연대류 까지의 전 영역에 걸쳐 구 주위의 속도 및 온도분포,국소열전달계 수 및 마찰계수를 Gr/Re$^{2}$의 함수로 구하였으며 Prandtl수가 0.7과 7인 유체에 대 하여 계산을 수행함으로써 Prandtl수의 변화에 따른 강제대류 및 자연대류의 비교강도 의 영향에 대하여 고찰하였다. 자연대류의 영향에 의한 벽면에서의 운동에너지증가 에 따른 유동의 박리점 이동에 대하여도 고찰하였다.

환형 캐스케이드 내 고정된 터빈 블레이드 및 슈라우드에서의 열/물질전달 특성 (I) - 블레이드 끝단 인접 표면 - (Heat/Mass Transfer Characteristics on Stationary Turbine Blade and Shroud in a Low Speed Annular Cascade (I) - Near-tip Blade Surface -)

  • 이동호;조형희
    • 대한기계학회논문집B
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    • 제29권4호
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    • pp.485-494
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    • 2005
  • For the extensive investigation of local heat/mass transfer on the near-tip surface of turbine blade, experiments were conducted in a low speed stationary annular cascade. The turbine test section has a single stage composed of sixteen guide vanes and blades. The chord length and the height of the tested blade are 150 mm and about 125 mm, respectively. The blade has flat tip geometry and the mean tip clearance is about $2.5{\%}$ of the blade chord. Detailed mass transfer coefficient on the blade near-tip surface was obtained using a naphthalene sublimation technique. The inlet flow Reynolds number based on chord length and incoming flow velocity is changed from $1.0{\times}10^{5}\;to\;2.3{\times}10^{5}.$ Extremely complex heat transfer characteristics are observed on the blade surface due, to complicated flow patterns, such as flow acceleration, laminarization, transition, separation bubble and tip leakage flow. Especially, the suction side surface of the blade has higher heat/mass transfer coefficients and more complex distribution than the pressure side surface, which is related to the leakage flow. For all the tested Reynolds numbers, the heat/mass transfer characteristics on the turbine blade are the similar. The overall averaged $Sh_{c}$ values are proportional to $Re_{c}^{0.5}$ on the stagnation region and the laminar flow region such as the pressure side surface. However, since the flow is fully turbulent in the near-tip region, the heat/mass transfer coefficients are proportional to $Re_{c}^{0.8}.$

낙동강 하구의 용존 메탄 분포와 메탄 플럭스의 계절변화 (Seasonal Variation of Dissolved Methane Concentration and Flux in the Nakdong Estuary)

  • 류제희;안순모
    • 한국해양학회지:바다
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    • 제21권3호
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    • pp.91-102
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    • 2016
  • 낙동강 하구역의 메탄 분포에 영향을 미치는 요인들을 알아보기 위하여, 2014년 1월, 9월, 11월 낙동강 하구에서 수층 메탄 농도의 시공간 분포를 살펴보고, 하구 내 메탄의 유입과 유출을 정량화하였다. 수층 메탄 농도는 21~874 nM의 범위를 보였으며, 수온과 유량의 영향으로 인해 겨울보다 여름에 더 높은 값을 보였다. 메탄은 주로 육상으로부터 강물을 통해 하구로 유입되기 때문에 상류에서 바다로 갈수록 감소하는 경향을 보였으며, 조간대나 둑 인근의 유기물이 풍부한 퇴적물 등 또 다른 메탄 유입원이 국지적으로 영향을 미친 결과, 계절에 따라 공간 분포 패턴이 다르게 나타났다. 다른 연안 지역과 비교하였을 때 낙동강 하구 수층 메탄 농도는 높은 편이었다. 이는 유역에 발달한 호소 환경과 둑의 정체 효과로 인해 강물 메탄 유입이 많기 때문으로 판단된다. 하굿둑 외측에서 메탄의 거동을 정량화한 결과 메탄은 주로 담수를 통해 유입되며 대기를 통해 유출되는 것으로 추정되었다. 낙동강 하구가 면적 당 높은 대기 방출을 보이는 이유는 울타리 섬이나 하굿둑 등에 의해 체류시간이 길어져 수층 메탄이 대기로 방출될 시간이 많아진 결과로 추정된다.