터빈 실(seal)의 유동 해석

송범호(Bum Ho Song),송성진(Seung Jin Song) 한국유체기계학회 2000 유체기계 연구개발 발표회 논문집 Vol.- No.-

Secondary flows in gas turbines, especially those associated tip clearance and labyrinth seals, have become a focus of interest for engine manufacturers. In the past, many analytical and experimental studies, which focused solely on the flows in either tip clearances or seals, have been conducted. This paper presents an analytical model that describes the flow response in a single stage turbine induced by a finite sealing gap at the turbine rotor. The flow is assumed to be axisymmetric and the analysis is done in the meridional plane. Upon going through the stage, the radially uniform upstream flow is assumed to split into two streams one associated with the seal and the other which has gone through the blades. The former is referred to as the leakage flow, and the latter is referred to as the passage flow. The passage flow is assumed to be inviscid and incompressible while the flow in the seal can be modeled as either inviscid or viscous. Thus, the model is capable of predicting the kinematic effects of labyrinth seals on the turbine flow field.

일반계 및 다수계 찹쌀 전분의 점성 특성

송범호(Bum-Ho Song),김성곤(Sung-Kon Kim),이규한(Kyu-Han Lee),변유량(Yu-Ryang Pyun),이신영(Shin-Young Lee) 한국식품과학회 1985 한국식품과학회지 Vol.17 No.2

빈혈판정 지표로서의 헤모글로빈, 헤마토크릿 및 혈청 페리틴

정해랑(Chung Hae-Rang),문현경(Moon Hyun-Kyung),송범호(Song Bum-Ho),김미경(Kim Mi Kyung) 韓國營養學會 1991 Journal of Nutrition and Health Vol.24 No.5

7일 실측법에 의한 영양소섭취량의 개인간변이와 개인내변이

정해랑(Chung Hae-Rang ),문현경(Moon Hyun-Kyung ),송범호(Song Bum-Ho ),김미경(Kim Mi Kyung) 韓國營養學會 1992 Journal of Nutrition and Health Vol.25 No.2

빈혈판정 지표로서의 헤모글로빈, 헤마토크릿 및 혈청 페리틴

정해랑,문현경,송범호,김미경 이화여자대학교 생명과학연구소 1991 생명과학연구논문집 Vol.2 No.-

본 연구는 생화학적 검사에 의한 철 영양상태의 판정시 검사항목에 따른 판정의 정확도를 보기 위하여 외견상 건강한 18!21세의 여대생 57명을 대상으로 혈액성분 중 Hb, Hct, serum ferritin을 측정하고 그 상관성을 분석하였다. 1) 조사대상자의 Hb는 평균이 13.9±0.96g/dl, 중앙값이 14.2g/dl였다. Hct의 평균은 41.4±2.85%, 중앙값은 42.0%였고,ferritin은 평균 20.7±15.5ng/ml, 중앙값 16.5ng/ml,최빈값 3.40ng/ml였다. Hb, Hct, ferritin값 모두 Kolmogorov-Smirnov test결과 정규분포 하는 것으로 나타났다. 2) Hb와 Hct간에는 r=0.9467(p<0.001)로 <Hct=2.28+2.81×Hb>의 회귀관계를 보였다. Hb와 ferritin간에 r=0.5591((P<0.001)로 <log(ferritin)= -1.73+0.07×Hct>의 회귀식이 구해졌다. 3) 빈혈발현율은 Hb 12g/dl를 기준시 5.3%, Hct 36% 기준시 10.5%, ferritin 12ng/ml 기준시 36.8%였다. 4) fFerritin함량을 기준하여 Hb, Hct판정에 대한 신뢰도를 분석한 결과, 빈혈 판정시 많이 이용되는 Hb 12g/dl 미만이나 Hct 36% 이하를 기준했을 때 두 방법 모두 sensitivity가 매우 낮았으며 specificity는 매우 높은 값을 보여, 빈혈 발현율이 높은 우리나라의 경우 Hb나 Hct의 판정기준치를 높일 필요가 있는 것으로 나타났다. 5) 빈혈 판정을 위한 검사방법으로서의 Hb측정은 sensitivity, specificity등을 고려할 때 판정 기준치를 14g/dl로 하는 것이 타당할 것으로 보인다. Hct의 경우 판정치를 40%로 높일 경우에 false-negative rate가 42.9로 낮아졌다. The iron status of 57female college students was evaluated by measurements of hemoglobin(Hb). hematocrit(Hct) and serum ferritin(Ferritin). Mean values for Hb. Hct and Ferritin were 13.9±0.96g/dl. 41.4±2.85% and 20.7±15.5ng/ml. respectively. Ferritin as well as Hb. Hct were not statistically different from normal distribution. although ferritin were skewed to the right. The prevalence of anemia defined by Hb<12g/dl. Hct≤36% and Ferritin<12ng/ml were found to be 5.3,10.3 and 36.8%. respectively. By using Hb as a screening tool at a cutoff point fo 12g/dl. 2.8% of healthy subjects will be incorrectly classified as anemic and 90.5% of anemic as healthy. Sensitivity and specificity were calculated at various cutoff points of Hb and Hct. The estimates of sensitivity and specificity allow Hb 14.0g/dl as cutoff point for good predictor of anemia.

학령전 아동의 성장에 영향을 미치는 환경요인 연구 : 신장-체중 지표에 의한 분석 Analysis with Weight-Length Index

문현경,송범호,정해랑 대한보건협회 1992 대한보건연구 Vol.18 No.1

To identify important environmental factors affecting growth of children in Korea, 906 children between 4 and 6 years old were studied in Seoul and Chunsunggun. Anthropometric measurements and interview were done by trained interviewers between May and June, 1988. Heights and weights were converted to WLI(Weight-Length Index). With WLI, 11.7% of surveyed children was underweight, 65.4%, was normal. 15.8% was overweight and 7.1% was obese. Each factor was compared by WLI groups by the analysis of variance. Mean of father's weight and mother's weight were significantly different among WLI groups(P<0.01). Mean of father's height and mother's height showed no differences among WLI groups(P>0.05). Proportions of children from urban area were higher in overweight and obese group than that from rural area(P<0.05). Mean of father's schooling showed no difference, but mother's schooling were increasing by increasing WLI(P<0.05). Mean of family incomes and housing index were increasing by increasing WLI(P<0.01). There were no significant differences in eight nutrient intakes among WLI groups. Generally, normal and overweight group has higher nutrient intake than underweight and obese group. For the growth of preschool aged children, socio-economic factors seems to be important determinants in Korea.

한국인의 상용 식품중 무기질함량과 분석방법 비교연구 : 1. 나트륨 1. Sodium

문현경,정해랑,송범호,이주돈,김희재,황성희 한국식품위생안전성학회 1991 한국식품위생안전성학회지 Vol.6 No.3

In order to observe the Na contents, Korean common foods, especially processed foods were analyzed by Atomic Absorption Spectrophotometer. 1. The Na contents of instant noodle (ramen) was 400-900 mg/100 g and Na contents of their soup powder was 10000-16000 mg/100 g. 2. The Na contents of corns snd beans was very low but their processed foods, corn flake and soybean milk, had relatively high Ns contents. 3. The Na contents of meats was 40-60 mg/100 g but the Na contents of meats products was 700-900 mg/ 100 g. 4. The Na contents of flavoring salt was 12000-38000 mg/100 g, those of soybean products was 3000-6000 mg/100 g, and that of seasoning MSG was 8000-17000 mg/100 g. 5. There was no statistical difference between the results of wet ash method and dry ash method in the Na contents of all food groups.

문헌의 식품중 콜레스테롤 함량에 관한 고찰

정해랑,문현경,송범호 한국지질학회 1991 韓國脂質學會誌 Vol.1 No.1

Since the level of blood choledterol known to be one of the major risk factor for the cardiovascular disease and hypertension, there have been many research to lower the level of blood cholesterol. Because it is known that dietary cholesterol is one of the factor affecting the levels of blood cholesterol, the choleaterol content of foods have been used to guide patient, to educate people for the prevention, and also to do research in the area of nutritional epidemiology. In the published literature, there are different levels of cholesterol for the same food, because of different sampling and analysis methods. Because it is necessary to know the range of cholesterol levels for the same food to use properly, the published literatures are reviewed for the cholesterol content of foods. There were many methods for the analysis of cholesterol contents in foods. Presently, enzyme methods and gas chromatography methods are prevailed. Gas choromatograph methods are known to be more reliable and valid method than other methods.

韓國 低所得層 幼兒의 成長類型과 發育標準値 선택에 관한 考察

文玄卿,鄭해랑,宋凡鎬,朴惠蓮 대한보건협회 1989 대한보건연구 Vol.15 No.1

One of the fundamental, but controversial issues in evaluating the growth patterns of children in developing countries has been whether or not the application of the uniform growth reference worldwide is justifiable and advisable. The prevailing view aeems to have been that it can be applied to children of any ethnic group, since the genetic origin does not make much difference in child's growth. This view has recently been challenged by some scholars. Noting that when the growth performances of children of some ethnic group, particularly of Asiatic origin, were compared to the NCHS growth standard, they displayed a consistent, and sizable growth faltering from the second year after birth. It was suggested that the growth faltering should be attributed to their physiological difference rather than nutritional inadequacy or poor nutritional environment, and that it is to blame for the smaller adult size of Asiatic peoples. When one compares the Korean growth standard with the NCHS growth curve, he can draw the same conclusion. The growth standards set up in 1966, 1975, and 1985 received a continued upward readjustment, narrowing the overall gap between them and the NCHS standards, in corresponding years. But all the three Korean growth standards are the same in that they recognize the growth faltering starting 6 to 7 months after birth. For example, the Korean weight and height standards for the period of 6 months after birth amount to the 70~90th percentile of the NCHS standard, while those at the end of the two year after birth belong to the 30~50th percentile. The result of a study conducted by the Korea Advanced Food Research Institute in 1987 for the sample of 679 infants taken from three different regions(first, a major city, Daejon; second, a minor city, Chunchon; third, a rural area, Chunsong county) seems to support the theory. The study found that the z-scores of both weight and height of Korean children from 2~3 months after birth were consistently faltering and size of the faltering reached about 2 s.d. for about one half years when analyzed based on the NHCS standard. When the data was compared to the Korean standard, however, the z-scores of both weight and height of them were found to be increasing in the normal range for 3~4 months thereafter and begin to fall again from around 7~8 months after birth, the time of starting weaning generally in Korea. These facts may well lead us to believe that genetic difference matters, and that the Korean standard, rather than the NCHS standard, can provide us with more accurate information about and safer assessment of the nutritional status and growth performance of Korean children.