Characteristics of Fluid Flow and Heat Transfer in a Fluidized Heat Exchanger with Circulating Solid Particles

Ahn, Soo-Whan,Lee, Byung-Chang,Kim, Won-Cheol,Bae, Myung-Whan,Lee, Yoon-Pyo The Korean Society of Mechanical Engineers 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.9

The commercial viability of heat exchanger is mainly dependent on its long-term fouling characteristic because the fouling increases the pressure loss and degrades the thermal performance of a heat exchanger. An experimental study was performed to investigate the characteristics of fluid flow and heat transfer in a fluidized bed heat exchanger with circulating various solid particles. The present work showed that the higher densities of particles had higher drag force coefficients, and the increases in heat transfer were in the order of sand, copper, steel, aluminum, and glass below Reynolds number of 5,000.

Induction of Apoptosis by the Licochalcone E in Endothelial Cells <i>via</i> Modulation of NF-κB and Bcl-2 Family

Chang, Hee Jung,Yoon, Goo,Park, Jung Sun,Kim, Mi Ha,Baek, Min Kyung,Kim, Nam Ho,Shin, Boo Ahn,Ahn, Bong Whan,Cheon, Seung Hoon,Jung, Young Do Pharmaceutical Society of Japan 2007 Biological & pharmaceutical bulletin Vol.30 No.12

<P>Licochalcones have a variety of biological properties including anti-tumor, anti-parasitic and anti-bacterial activities. Recently, a new retrochalcone (licochalcone E, Lico-E) was isolated from the roots of <I>Glycyrrhiza inflata</I> (<I>Chem. Pharm. Bull.</I>, 53, 2005, Yoon <I>et al.</I>) by cytotoxicity-guided fractionation. This study examined whether or not Lico-E-induced endothelial cell death occurs through apoptosis, and investigated molecular mechanisms involved in this process. Lico-E was found to suppress ECV304 cell growth and induce apoptosis. The induction of apoptosis by Lico-E was confirmed by the ladder-patterned DNA fragmentation, the presence of cleaved and condensed nuclear chromatin and the increased number of annexin V-positive cells. Lico-E could effectively inhibit the constitutive NF-κB activation, as revealed by the electrophoretic mobility shift assay and NF-κB-dependent luciferase reporter study. In addition, the Lico-E treatment caused a change in the Bax/Bcl-2 ratio that favored apoptosis. These results suggest that Lico-E induces endothelial cell apoptosis by modulating NF-κB and the Bcl-2 family.</P>

GIS를 이용한 인위적 홍수방재구역의 설정

안창환(Chang-Whan Ahn),최현(Hyun Choi),남광우(Kwang-Woo Nam),강인준(In-Joon Kang) 대한공간정보학회 2007 한국지형공간정보학회 학술대회 Vol.2007 No.6

본 연구는 화포천의 경우와 마찬가지로 하천 본류의 외수위가 하천의 내수위보다 높아 홍수 시 외수위의 범람을 방지하기 위해 본류와의 합류지점을 차단하여 유역 내 모든 홍수유출량을 하도가 부담해야하는 상황일 때, 하도가 부담할 수 있는 홍수유출량을 계산하고 GIS를 이용하여 유역내의 보다 공간적인 접근을 통하여 극한의 상황에서 초과되는 홍수유출량을 인위적으로 저류할 수 있는 홍수터를 사전에 설정함으로써 피해가 최소화 될 수 있는 방안을 마련하는데 대한 연구이며, 개발행위를 억제할 수 있는 홍수방재 구역의 법적 제도를 마련하는데 필요한 기초 자료를 제공하는데 그 연구목적이 있다.

Characteristics of Fluid Flow and Heat Transfer in a Fluidized Heat Exchanger with Circulating Solid Particles

Soo Whan Ahn,Byung-Chang Lee,Won-Cheol Kim,Myung-Whan Bae,Yoon Pyo Lee 대한기계학회 2002 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.16 No.9

The commercial viability of heat exchanger is mainly dependent on its long-term fouling characteristic because the fouling increases the pressure loss and degrades the thermal perform­ance of a heat exchanger. An experimental study was performed to investigate the characteristics of fluid flow and heat transfer in a fluidized bed heat exchanger with circulating various solid particles. The present work showed that the higher densities of particles had higher drag force coefficients, and the increases in heat transfer were in the order of sand, copper, steel, aluminum, and glass below Reynolds number of 5,000.<br/>

1998, 1999년도 우리나라에서 시행된 유방보존수술 후 방사선치료 현황 조사

서창옥(Chang-Ok Suh),신현수(Hyun Soo Shin),조재호(Jae Ho Cho),박원(Won Park),안승도(Seung Do Ahn),신경환(Kyung Hwan Shin),정은지(Eun Ji Chung),금기창(Ki Chang Keum),하성환(Sung Whan Ha),안성자(Sung Ja Ahn),김우철(Woo Cheol Kim),이명자( 대한방사선종양학회 2004 Radiation Oncology Journal Vol.22 No.3

목 적: 유방암에 대한 방사선치료의 적정성과 안전성을 보장하고 궁극적으로 치료 효과를 향상시키기 위한 방사선치료 기술 표준화를 위하여 우리나라 전국의 병원을 대상으로 하는 치료 형태 조사연구(Patterns of Care Study)를 계획하였다. 그 첫 단계로 유방보존적 수술 후 시행한 방사선치료 방법에 대하여 조사하고 분석하였다. 대상 및 방법: 조사하고자 하는 입력 문항을 개발하였고 동시에 인터넷을 통하여 조사자가 직접 입력할 수있도록 Web 기반 입력 프로그램(www.pcs.re.kr)을 개발하였다. 대상 환자들은 1998년도와 1999년도에 유방보존술 후 방사선치료를 받은 환자로 전수 조사를 하지 않고 표본 추출하여 조사하였다. 입력 문항은 127개로 병력과 이학적 소견, 수술 소견과 병리 소견, 항암화학요법, 호르몬요법, 방사선치료계획, 방사선치료, 치료중 부작용, 치료 효과, 합병증, 미용 효과 등 10군으로 나누어져 있다. 15개 병원에서 입력된 261명의 데이터를 분석하였다. 결 과: 연령은 24∼85세(중앙값 45세)였다. 병리학적 유형은 관상피암종이 88.9%로 대부분을 차지하였으며 수질성암종이 4.2%, 소엽상피암종이 1.5%였다. 병기는 AJCC (American Joint Committee on Cancer) 5판에 따라 분류하였으며 T1이 59.7%, T2가 29.5%, Tis가 8.8%였으며 전체의 42.5%가 T1c에 해당하였다. 전체 환자의 91.2%에서 액와림프절 곽청술이 시행되었고 69.7%의 환자들에서는 액와림프절 전이가 없었으며 림프절 전이가 3개 이하인 경우가 15.3%, 4∼9개가 4.2%, 10개 이상 전이된 경우가 1.9%였다. 따라서 병기 0기가 8.4%, I기, 44.9%, IIA기, 33.3%, IIB기 8.4%였다. 에스트로겐수용체와 프로게스테론수용체 검사는 각각 71.6, 70.9 % 에서 이루어졌다. 유방보존적 수술 방법은 단순절제술(excision/lumpectomy)이 37.2%, 광범위절제술이 11.5% 사분원절제술(quadrantectomy)이 23%, 부분절제술(partial mastectomy)이 27.5%에서 시행되었다. 수술 후 10예 (3.8%)에서 절제연이 양성이었고 10예는 절제연이 종양에서 2 mm 이내였다. 항암화학요법은 I기에서 54.7%, IIA기에서 83.9%, IIB에서 100% 시행되었다. 방사선치료는 1예를 제외한 모든 환자들이 계획된 방사선량의 90% 이상을 조사 받음으로써 순응도가 매우 높은 치료임을 알 수 있었다. 방사선치료의 범위는 전체의 88% 가 유방만 치료받았고 5%는 유방과 쇄골상부림프절을, 4.2%는 유방, 쇄골상부림프절에 액와림프절후방추가조사를 하였으며, 유방, 쇄골상부림프절과 함께 내유방림프절을 치료하였던 예는 1예(0.4%) 뿐이었다. 유방치료에 사용된 방사선의 종류는 Co-60가 8명(3.1%), 4 MV X-ray가 115명(44.1%), 6 MV X-ray가 125명(47.8%) 이었으며 11명(4.2%)은 10 MV X-ray를 사용하였다. 조사된 방사선량은 유방 전체에 45∼59.4 Gy (중앙값 50.4), 원발 병소에 대한 추가 조사가 8∼20 Gy (중앙값 10 Gy)로 총 방사선 조사선량은 50.4∼70.4 Gy (중앙값 60.4 Gy)였다. 결 론: 조기 유방암에 대한 진단과 병기 결정 과정, 유방보존적 수술 후 시행되는 방사선치료는 큰 편향이없이 권고안대로 잘 시행되고 있었다. 다만 원발 병소에 대한 추가 치료는 비교적 다양하게 적용되고 있는데 이것이 치료 결과에 어떤 영향을 미치는지 추적조사연구가 필요하며 방사선치료 계획상의 세부 사항에 대한 분석과 평가가 향후 이루어져야 할 것이다. Purpose: To determine the patterns of evaluation and treatment in the patient with early breast cancer treated with conservative surgery and radiotherapy and to improve the radiotherapy techiniques, nationwide survey was performed. Materials and Methods: A web-based database system for Korean Patterns of Care Study (PCS) for 6 common cancers was developed. Two hundreds sixty-one randomly selected records of eligible patients treated between 1998∼1999 from 15 hospitals were reviewed. Results: The patients ages ranged from 24 to 85 years(median 45 years). Infiltrating ductal carcinoma was most common histologic type (88.9%) followed by medullary carcinoma (4.2%) and infiltrating lobular carcinoma (1.5%). Pathologic T stage by AJCC was T1 in 59.7% of the casses, T2 in 29.5% of the cases, Tis in 8.8% if the cases. Axillary lymph node dissection was performed in 91.2% of the cases and 69.7% were node negative. AJCC stage was 0 in 8.8% of the cases, stage I in 44.9% of the cases, stage IIa in 33.3% of the cases, and stage IIb in 8.4% of the cases. Estrogen and progesteron receptors were evaluated in 71.6%, and 70.9% of the patients, respectively. Surgical methods of breast-conserving surgery was excision/lumpectomy in 37.2%, wide excision in 11.5%, quadrantectomy in 23% and partial mastectomy in 27.5% of the cases. A pathologically confirmed negative margin was obtained in 90.8% of the cases. Pathological margin was involved with tumor in 10 patients and margin was close (less than 2 mm) in 10 patients. All the patients except one recieved more than 90% of the planned radiotherapy dose. Radiotherapy volume was breast only in 88% of the cases, breast+supraclavicular fossa (SCL) in 5% of the cases, and breast+SCL+posterior axillary boost in 4.2% of the cases. Only one patient received isolated internal mammary lymph node irradiation. Used radiation beam was Co-60 in 8 cases, 4 MV X-ray in 115 cases, 6 MV X-ray in 125 cases, and 10 MV X-ray in 11 cases. The radiation dose to the whole breast was 45∼59.4 Gy (median 50.4) and boost dose was 8∼20 Gy (median 10 Gy). The total radiation dose delivered was 50.4∼70.4 Gy (median 60.4 Gy). Conclusion: There was no major deviation from current standard in the patterns of evaluation and treatment for the patients with early breast cancer treated with breast conservation method. Some varieties were identified in boost irradiation dose. Separate analysis for the datails of radiotherapy planning will be followed and the outcome of treatment is needed to evaluate the process.

유한 요소 해석법을 이용한 척추경 나사못 삽입 상태가 고정력에 미치는 영향에 대한 연구

안면환(Myun-Whan Ahn),안창수(Chang-Soo Ahn),최용석(Yong-Suk Choi),서재성(Jae-Sung Seo),이춘열(Choon-Yeol Lee),정일섭(Il-Sub Chung) 대한정형외과학회 2002 대한정형외과학회지 Vol.37 No.1

슬관절 관절경술 300례에 대한 분석

안진환(Jin Whan Ahn),유명철(Myung Chul Yoo),정덕환(Duke Whan Chung),김회창(Hoi Chang Kim) 대한정형외과학회 1982 대한정형외과학회지 Vol.17 No.5

고감도 Ames test(microsuspension assay)와 임파구 소핵시험법을 이용한 변이원성에 관한 조사 연구

안지영,김해준,윤인재,성영자,김영환,장영철 大韓産業醫學會 1996 대한직업환경의학회지 Vol.8 No.3

In order to evaluate the mutagenic effects of extractable indoor air pollutants (organic matters), we measured the mutagenic activities by sensitive microsuspension Ames test using new tester strains (YG 1024 and YG 1029). And additionally to evaluate the mutagenic effects on vital cell, we examined the frequencies of micronucleus appearing in lymphocytes from dye handling workers and controls. This study was conducted from Jan. to May, 1995. The extractable indoor air pollutants were collected by low volume air sampler in a general office room and 3 of dye handling factories. And the environment of general office room divided into 3 different groups according to the type of room heaters. To determine the frequencies of micronucleus appearing in lymphocytes, we sampled peripheral venous blood from 20 of dye handling workers and 20 of controls, and cultured, and then examined the lymphocytes. The results obtained were as follows: 1. The indirect mutagenic activities of extractable organic matters from suspended particulates collected in a general office room were higher than the direct one. 2. The strain YG 1024 was the most sensitive, and the increasing order of test strains that showed higher number of revertant were YG 1024, YG 1029, TA 100, TA 98. 3. In the general office room, the room using kerosene heater showed the highest mutagenecity, and the next was buthan gas heater, and non-heating room in order. 4. The mutagenic effects of suspended particulates in dye handling factories on the strain YG 1024 was 1.2 times higher than YG 1029. 5. The frequencies of micronucleus appearing in lymphocyte of the circulating blood of dye handling workers and the control were 5.65±2.97‰ and 4.65±0.97‰, respectively. And the difference was statistically significant.

제품범주 내의 브랜드전략 유형

안길상,정창환 충북대학교 산업경영연구소 1997 産業과 經營 Vol.10 No.1

오늘날 제로섬 게임으로 치닫는 치열한 경쟁, 시장의 극세분화, 기술 및 고객욕구의 급속한 변화로 인해 제품/시장 내의 브랜드/세분시장구조가 역동적으로 변화하고 있는데 이러한 상황전개는 제품범주관리차원에서 보면 일면 성장의 기회를 제공해 주고 있어서 브랜드/세분시장관리의 중요성을 시사해 주고 있다. 본 연구에서는 제품범주 내에서의 기업의 브랜드전략대안으로서 브랜드침투전략, 브랜드교체전략, 브랜드확장전략, 브랜드다각화전략 등 네가지를 제시하고, 지난 수년간 우리나라 업계가 실행해 왔던 브랜드 및 마케팅전략의 실증분석을 통해 본 연구에서 제시한 브랜드전략유형의 실무에의 적용가능성을 확인하였다. 사례분석 결과를 통하여 브랜드전략실행의 성공률이 매우 낮은 것을 발견하였는데, 이는 브랜드/세분시장관점의 성장전략에 관한 학계의 연구부족과 업계의 무관심에도 그 원인이 있음을 암시해 주고 있어서 이 분야에 대한 지속적 관심이 요구되고 있다.

만성신부전 환자에서 발생한 기무라씨 질환에 의한 급성신부전 1예

장윤식,김창환,안석주,방병기,박철휘,장데레사 대한신장학회 1998 Kidney Research and Clinical Practice Vol.17 No.6

Kimura's disease is a granulomatous disease which develops in the skin, subcutaneous tissues and lymph nodes and is characterized histologically by the presence of lymphoid follicles, vascular proliferation and infiltration with eosinophils. The disease shows geographical predilection to Japan, China and South East Asia. The exact etiology and pathogenesis remain uncertain. Some patients had proteinuria or nephrotic syndrome. We have recently experienced the superimposed oliguric acute renal failure associated with Kimura's disease in a male patient with chronic renal failure who had been managed conservatively. Inguinal lymph node biopsy revealed Kimura's disease. He recovered from acute renal failure after being treated with hemodialysis and prednisolone. Lymphadenopathy and fever subsided with steroid treatment. We report a case of Kimura's disease which was comp- licated by acute renal failure in the patient with chronic renal failure.