초음파 공명 분광법(RUS)을 이용한 SiC 입자강화 Al 기지복합재료의 탄성계수 해석

홍순형,주영상,정용무,정현규 韓國非破壞檢査學會 1999 한국비파괴검사학회지 Vol.19 No.3

SiC 입자강화 2124Al 금속복합재료의 강화재 부피분율에 따른 탄성 stiffness를 초음파 공명 스펙트로스코피(resonant ultrasound spectroscopy: RUS) 방법을 이용하여 측정하였다. RUS 방법은 한 개의 소형 시편으로 9개의 독립변수를 가진 사방정계(orthorhombic) 탄성계수를 간단한 실험으로 측정가능함을 보여주었다. SiC 강화재 부피분율 변화에 따른 탄성계수를 측정하였는데 이 경우 초기 추정 탄성계수를 구하기 위해서 부피분율에 따른 미세조직 사진으로부터 강화재의 형상(aspect ratio)과 방향을 고려한 유효 aspect ratio 개념을 도입하였고, Mori-Tanaka 이론식에 의한 계산결과를 이용하였다. 이로부터 계산된 공진주파수와 RUS의 측정 공진주파수 사이를 최소화함으로 정확한 탄성계수를 측정하였다. 측정된 stiffnesses로부터 공학적 탄성계수인 Young's modulus를 계산하였으며, 계산된 Young's modulus와 압출방향으로 인장시험한 Young's modulus를 비교분석하였다. SiC 입자의 부피분율이 증가함에 따라 탄성계수가 증가함을 나타내었고, 탄성 stiffness의 거동은 강화재가 많이 첨가될수록 횡등방성(transversely isotropic) 이 강하게 나타났으며 이것은 압출공정에 의해 강화재 입자의 방향성 재배열에 기인한다. 한편 일정크기 시편에 있어서 기본 공진주파수가 강화재 부피분율에 따라 고주파수 영역으로 이동하는 현상이 관찰되었으며, 이로 부터 비파괴적으로 강화재 부피분율을 예측할 수 있는 가능성을 제시하였다. The dynamic elastic properties of metal matrix composites were investigated by resonant ultrasound spectroscopy(RUS). The composites used in this study consisted of 2124 aluminum alloy reinforced with different concentrations of SiC particles. RUS can determine the nine independent elastic stiffness(C )for the orthorhombic symmetry on a small specimen simultaneously. The elastic constants were determined as a function of the volume fraction. A concept of effective aspect ratio, which combine the aspect ratio and the orientation of reinforcement, was used to calculate the initial moduli from Mori-Tanaka theory for the input of RUS minimization code. Young's moduli can be obtained from the measured stiffnesses. The results show that the elastic stiffness increases with increment of the particle content. The behavior of elastic stiffness indicates that the particle redistribution induced by the extrusion process enlarges the transversely isotropic symmetry as the fraction of reinforced particles increase. This relationship could be used for determination of the volume fractions of reinforcement as a potential tool of nondestructive material characterization.

서울의 PPNG 발생 빈도(1991-1992)

김재홍,윤기범,박평원,김영진,전경민,김영태,김중환,곽호,구상완,송민석,유옥,지혜구,김동원,문상은,박영립,정승호,성범진,성순제,엄주용,황정열,이기홍,이주협,전태진 대한화학요법학회 1994 대한화학요법학회지 Vol.12 No.1

The prevalence of PPNG among pretreated gonorrhea cases isolated at the STD clinic of Choong-Ku Public Health Center in Seoul has been studied and reported annually since 1981. In 1991, 123 strains of N.gonorrhoeae were isolated, among which 58(47.1%) were PPNG. In 1992, 98 starains of N.gonorrhoeae were isolated, among which 51(52.0%) were PPNG. In all, 109(49.3%) strains were found to be PPNG among 221 strains isolated between 1991-1992. The prevalence of PPNG in Seoul showed increased tendency till 1989, thereafter, it has been stationary or slightly decreasing.

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1998)

김재홍,김준호,반재용,이정우,황성주,정준규,정성태,강진문,조흔정,홍창의,정혜신,이한승,김이선,이봉길,이종호,선영우,한기덕,윤성필,이성훈,안종성,박석범,문승현,조항래,김형섭,류지호,황재영,박준홍,손상욱 한양대학교 의과대학 2001 한양의대 학술지 Vol.21 No.1

In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria gonorrhoeae(PPNG), we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by menas of the chromogenic cephalosporin method. In 1998, 93 strians of N. genorrhoeae were isolated, among which 60(64.5%) were PPNG. The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 64.5% in 1998.

급성심근경색증을 가진 한국인에 있어 Chlamydia Pneumoniae 감염의 영향에 대한 연구

이은미,오동주,황교승,안정천,송우혁,임도선,박창규,김영훈,서홍석,심완주,노영무,정희진,김우주,김종헌,송기준 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.4

연령증가에 따른 혈압요소들의 좌심실비대 및 관동맥질환과의 관련성

박재석,박창규,박미영,박재형,김용현,나진오,신성희,서순용,홍순준,박성미,임홍의,김응주,서홍석,오동주,노영무 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.2

울산지역 유아의 영양 상태에 관한 연구 : Ⅰ. 식습관과 식행동

홍순명,서영은,김현주 울산대학교 2001 생활과학논문집 Vol.3 No.1

본 연구는 울산에 거주하는 학령 전 어린이 142명을 대상으로 식습관과 식행동에 관하여 조사하였다. 조사대상 어린이는 남아 72명, 여아 70명으로 연령분포는 2세에서 7세 이었으며 규칙적인 식사시간을 지키는 남아가 48.6%이고, 여아는 42.9%였다. 조사대상자의 식습관에 있어서는 남아가 '좋은 편(13.9%)', '보통(58.3%)', '나쁜 편(27.8%)'으로 나타났고, 여아의 경우는 '좋은 편(11.4%)', '보통(62.9%)', '나쁜 편(25.7%)'으로 나타났다. 식습관 점수는 '보통'으로 평가되었고 남녀간의 유의적인 차이는 없었다. 조사대상자들의 긍정적인식행동 점수는 남아의 경우, '좋은 편(15.3%)', '보통(76.4%)', '나쁜 편(8.3%)' 이고, 여아는 '좋은 편(15.7%)', '보통(74.3%)', '나쁜 편(10.0%)'로 나타났다. 조사대상자들의 부정적인 식행동 점수는 남아의 경우, '나쁜 식행동이 적은 편(23.6%)', '보통(76.4%)', '나쁜 식행동이 많은 편(0.0%)'이고, 여아는 '나쁜 식행동이 적은 편(21.4%)', '보통(75.7%)', '나쁜 식행동이 많은 편(2.9%)'으로 나타났다. 조사대상자들의 식행동 총점은 '보통'으로 평가되었고, 남녀간의 유의적인(p<0.001) 차이를 나타내었다. 긍정적인 식행동과 식습관 간에는 유의적인 (p<0.05, p<0.001) 양의 상잔성이 있었고, 부정적인 식행동과 식습관 간에는 유의적인 ((p<0.05, p<0.001) 응의 상관성이 있었다 본 연구의 결과는 학령전 어린이에게 적용할 메뉴를 계획하는 프로그램과 영양교육의 자료로 이용될 수 있을 것이다. The nutritional status of 142 preschool children in Ulsan area was surveyed. A survey was conducted on parents using lluestionnaires including general characteristics, subjective symptoms, flood habit and eating behavior The children involved in this study were 72 boys and 70 girls, aged 2 to 7 years old. 48.6% in boys and 42.9% in girls were on'regular'meal times, The food habit score of the subjects was divided into Poor(27.8%), fair(58.3%) and good(13.9%) in boys, poor(25.7%), fair(62.9%) and good(11.4%) in girls. The positive eating behavior score of the subjects was divided into poor(8.3%), fair(76.4%) and good(15.3%) in boys, poor(10.0%), fair(74.3%) and good(15.7%) in girls. The negative eating behavior score of the subjects was divided into poor(0.0%), fair(76.4%) and good(23.6%) in boys, poor(2.9%), fair(75.7%) and good(21.4%) in girls. The relation of the flood habit and positive eating behavior is significantly(p<0.05, p<0.001) positive correlation and the relation of the food habit and negative eating behavior is significantly(p<0.05, p<0.001) negative correlation. The results of this study indicate that nutrition education and menu planning program should be applied to preschool children.

장기간 보관한 멸균물품의 오염 상태에 관한 연구

주홍순,조순덕,정재심,신동분,임바올라,노은지,이선희,송영미,최정화,백병윤,김미나 대한병원감염관리학회 2003 의료관련감염관리 Vol.8 No.1

잣나무림의 林冠構造 및 分光特性에 關한 硏究

朱榮特,金英彩,金洪律 경희대학교 부설 식량자원개발연구소 1996 硏究論文集 Vol.17 No.-

잣나무 인공림의 林冠構造의 분석과 분광특성, 엽록소 함량을 비교 조사하기 위하여 Standard Cosine Receptor(LI-COR-1800-11)와 Portable Spectroradiometer(LI-COR-1800-22), 比色計(UV-spectrophotometer)를 이용, 경기도 광주군 퇴촌면 소재 경희대학교 연습림에 시험조사구를 설치 측정 조사한 결과를 요약하면 다음 과 같다 1. 조사대상지의 林冠構造는 평균수고 11.03±0.10(m)에 대하여 平均 樹冠長은 6.69±0.67(m)로서 약 63.4%의 수관심도를 갖는 우수한 林冠溝造를 나타내었다. 2. 樹冠構造에 따른 光合成 效率을 알아보기 위한 分光特性에서 잣나무 잎의 연령별 光反射 係敎는 당년생 잎이 가장 높은 값(0.063~0.49)를 보였으며 대체로 엽령이 높아질수록 광반사계수는 낮아졌다. 3. 또한 엽령별로 측정된 光透過率에 있어서 透過係數는 당년생 잎이 가장 높은 값(0.003~0.139)을 보였으며, 1년생, 2년생, 3년생의 葉齡別 順으로 점차 잎의 노령화에 따른 감소경향을 보이고 있었다. 4. 이상의 光透過率과 反射率에 있어서 斜面 位置別로 채취한 잎에서 나타난 결과는 항상 태양광선을 많이 받는 임목의 상부에서 가장 높은 反射率(0.06~0.47)을 보였으며, 光透過率은 斜面 中部의 잎에서 그 값이 가장 높게(0.002~0.130) 나타났다. 5. 각 조사 대상목의 잎에 대한 전체적인 葉綠素의 含量은 1년생 잎에서 Chlorophyll a : 1.59㎎/g, Chlorophyll b : 0.54㎎/g 로 제일 높게 나타났으나, 葉綠素 構成比에 있어서는 Chlorophyll a/b : 3.51 로 당면생 잎이 가장 높은 측정치 를 보였는데, 연령이 낮을수록 이들 값은 감소하는 경향을 보였다. This study was carried out to examine the variation of chlorophyll contents and spectral properties in the needle of Pinus koraiensis. The sample needles were collected from Kyung Hee Univ. experimental forest located on kyunggi province by slope gradients with lower, middle and upper levels. Clorophyll contents and spectrum analysis was conducted on current year, 1 year old, 2 years old and 3 years old needles. The best condition of forest canopy structure of investigation area was approximately 63.4% of crown depth. This study also shows the following results on the photosynthesis effiency of crown structure : (1) The higest values of reflection coefficient was 0.063∼0.490 obtained from the needle of current year. (2) The highest tansmittance coefficient was 0.003∼0.139 from the needle of current year. (3) Reflexibillity at upper position of trees and the transmittance at the middle slope had the highest values(0.06-0.47 and 0.002∼0.130, respectively). (4) The chlorophyll content of the 1 year old needle had the highest values(chlorophyll a : 1.59㎎/g), but a rate of chlorophyll content of current year showed highest values(chlorophyll a/b : 3.51).

복합문화공간의 색채계획 : 수원시 영통구 상업지구를 중심으로

서주환,여화선,최선주,박선영,김옥경,승지현,김홍균 경희대학교 부설 디자인연구원 2007 예술· 디자인학연구 Vol.10 No.1

The recognition on leisure living which have been enjoyed by prestige level from popular persons is now widely spreaded in modern capitalism society and change of the leisure living influenced very much to the society and Industry. The 5 day work per week system expanded to the school and contemporary leisure living of the people is recognised as one culture with various contents. This change of leisure living made a recognition on the need for a space for leisure culture contents, which related to a creation of Complex-culture facility to contain various type of multiple leisure culture. The Complex-culture facility is mainly focused on the entertainment space with increased leisure living, which is consist of important element of the Complex-culture facility as performance space, exhibition, sports and shopping space to construct performance hall, theater, exhibition room, sports center, shopping mall, leisure space and plaza. This study, therefore, will Investigate on the function and value of color, and review on the cases of Complex-cultural facility and then choose a space of cultural element lack. It will recompose in Complex-cultural facility.

생쥐 피부의 창상치유에 관한 형태학적 관찰

이향주,이영호,김홍선,김원식 충남대학교 의과대학 지역사회의학연구소 1989 충남의대잡지 Vol.16 No.1

The back skin of ICR mice were incised. The skin tissues were obtained from the incised wound on the 1st day, 1st weeks, and 2nd week after incision. And these tissue were fixed in 10% neutral buffered formalin and 2.5% glutaraldehyde solution. And, the formalin-fixed tissues were stained by PAS and alcian blue-safranin for the research of morphological changes of epidermis and the mast cells and granulation tissues of dermis. The tissues fixed in 2.5% glutaraldehyde solution were prepared for scanning electron micros-copy, and observed the crusts of scar surface. The results were as follows. 1. The collagen fibers in he granulation tissues at wound region were increased gradually, and became more dense than normal skin on the 2nd week after incision. 2. The newly-formed epidermis was thicker than that of normal skin at the 1st week, and increased in thickness to the 2nd week after incision gradually. 3. The mast cells were decreased in number than those of normal skin on the 1st day after incision, however, increased than those of normal skin on the 1st week after incision. On the 2nd week, the number of the mast cell were similar to those of normal skin. 4. Mixed mast cells containing both histamine and heparin appeared the granulation tissues on the 1st day and 1st week after incision. 5. In scanning electron microscopy, fibrin network on the scar began to appear on the 1st day, formed in a row on the 1st week. But fibrin network changed into irregular rough crusts on the 2nd week after incision.