痲醉와 獸因性 疾患

金光宇 최신의학사 1975 最新醫學 Vol.18 No.10

노화(老化)에 의한 아스팔트 시멘트 형질변화(形質變化)의 HP-GPC 분석(分析)

김광우,연규석,최중대,Kim, Kwang Woo,Yeon, Kyu Seok,Choi, Joong Dae 대한토목학회 1992 대한토목학회논문집 Vol.12 No.4

This study was conducted to evaluate physical property change of asphalt cement chromatograms (by HP-GPC) were experimentally obtained from 3 types of AC-20 virgin ACs, 5 and 24-hour artificially aged ACs, and naturally aged 4 ACs that were recovered from 4 different roads. Absolute viscosity, kinematic visoosity and penetration were the physical properties tested. THF was used for mobil phase and RI detector was used as a detector for Hp-GPC testing. Correlation between each physical property change and the chromatogram variation was evaluated. Each chromatogram was divided into ten-equal-time slices. The percentage areas of 10 slices and each physical property were used for statistical correlation evaluation. Statistical analysis results showed that eaoh physical property had a strong correlation with the chromatogram characteristics. Aging was identified as a mechanism of change of molecular size distribution - increasing large size molecules and reducing coresponding samll size molecules. 본 연구(?究)는 노화(老化)에 의한 아스팔트시멘트의 물리적 성질변화를 크로마토그램에 근거(根據)하여 유성학적(流性學的)으로 고찰(考察)하였다. 3종류의 AC-20 아스팔트시멘트와 그것을 인공노화(人工老化)시킨 것 그리고 도로(道路)포장의 코어로부터 추출(抽出)해낸 자연노화(自然老化)된 아스팔트에 대하여 3가지 물리적 성질과, 고압(高壓) 겔 투과(透過) 크로마토그래프(HP-GPC)를 이용한 크로마토그램(분자입도분포(分子粒度分布))을 측정(測定)하였다. 이 물리적 성질과 HP-GPC 결과를 분석(分析)하여 노화전후(老化前後)의 크로마토그램과 물리적 성질의 상관관계(相關關係)를 고찰(考察)하였다. 물리적 성질로는 점도(粘度), 동점도(動粘度), 퇴입도(退入度)를 구하였으며, HP-GPC 시험에서는 THF가 순환용액으로 사용되고 RI 검출기가 사용되었다. 크로마토그램을 같은 시간간격(時間間隔)의 10구간으로 분할(分割)하여, 각 구간의 분할면적비(分割面積比)와 물리적 성질이 통계분석(統計分析)에 사용되었다. 이 연구결과(?究結果) 아스팔트시멘트의 물리적 성질은 크로마토그램 특성과 매우 밀접한 관계가 있음을 알 수 있었다. 또한 아스팔트의 노화는 유성학적으로 분자입도의 구성비가 변환되는 과정임을 알 수 있었다.

상부위장관내시경 소견과 핵심칠정척도 단축형을 활용한 정서적 특성 연구

김광우,고경진,한민석,강성현,강형원,류영수 대한한방신경정신과학회 2022 동의신경정신과학회지 Vol.33 No.1

Objectives: To perform correlation analysis between the Core Seven Emotions Inventory-Short Form (CSEI-s), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), upper gastrointestinal symptoms, and gastroscopic findings and to compare emotional characteristics with upper gastrointestinal endoscopic findings. Methods: In this study, medical records of 38 participants who visited the hospital for examination purposes or complained upper gastrointestinal symptoms and completed the CSEI-s, BAI, BDI, and Questionnaire for upper gastrointestinal symptoms were analyzed using SPSS (Statistical Package for the Social Sciences) version 25.0. Frequency Analysis, Descriptive Analysis, Independent t-test, Mann- Whitney’s U-test, and Correlation analysis were performed. Results: The upper gastrointestinal symptom group showed higher levels of anger, sorrow, depression, and anxiety than the asymptomatic group. On gastroscopy, the normal group had higher levels of Joy than the abnormal group. The reflux esophagitis group showed higher levels of thought, depression, sorrow, and anxiety than the non-reflux esophagitis group. Joy showed a negative correlation with BDI score. However, anger, depression, sorrow, BAI, and BDI score showed positive correlations. Conclusions: Results of this study suggest that CSEI-s can be used to treat patients with upper gastrointestinal symptoms and reflux esophagitis.

소 도로포장 재료로서 재생콘크리트의 역학적 특성

김광우,류능환,박용철 한국콘크리트학회 1996 콘크리트학회지 Vol.8 No.5

본 연구는 소도로 포장용 재료로서 재생콘크리트의 역학적 특성과 성능을 규명하였다. 재생콘크리트는 굵은 골재의 반을 재생골재로 대치하여 제조되었고 이와 함께 천연 잔골재와 유동화제 그리고 플라이애쉬(각각 시멘트 중량의 0.8% 및 5%)가 사용되었다. 실험을 통하여 재령28일 재생콘크리트의 휨강도, 압축강도, 탄성계수 및 파괴인성은 약 $45kg/cm^2$, $250kg/cm^2$, $230,000kg/cm^2$ 및 $0.863 MPa{\cdot}m^{1/2}$으로 나타났고 또한 6개월 지난 후 이 압축강도 및 파괴인성이 크게 향상되었다. 결론적으로 재생콘크리트는 역학적으로 도시나 농촌지역 소도로의 콘크리트 포장 재료로 충분히 적용 가능한 특성을 가진 것으로 판단되었다. This study evaluated mechanical characteristics and performance of recycled concrete as a pavement material for use in low volume road. The recycled concrete was prepared by replacing a half of coarse aggregate with recycled coarse aggregate. Natural sand from a source was used as fine aggregate together with admixtures, such as plasticizer and fly ash (0.8% and 5% by wt. of total binder, respectively). From experimental evaluation. it was found that flexural strength. compressive strength, elastic modulus and fracture toughness of recycled concrete at 28 days were approximately $45kg/cm^2$, $250kg/cm^2$, $230,000kg/cm^2$ 및 $0.863 MPa{\cdot}m^{1/2}$. respectively. Long term strength and fracture toughness were improved significantly at the age of 6 months. In conclusion. mechanical properties of the recycled concrete were acceptable for use as concrete pavement materials in low-volume roads in rural and urban areas.

전단 반사균열 모사 실험방법 개발 및 적용성 연구

김광우,임성빈,도영수,이석근,Kim, Kwang-Woo,Yim, Sung-Bin,Doh, Young-Soo,Rhee, Suk-Keun 한국도로학회 1999 한국도로포장공학회 논문집 Vol.1 No.1

본 연구에서는 노후된 기존 콘크리트 포장위에 아스팔트 덧씌우기를 했을 때 윤하중으로 인하여 발생하는 전단 반사균열을 모사할 수 있는 실내 실험방법을 개발하였다. 또한 각 혼합물의 기본 특성시험을 토대로 본 연구에서 개발한 실험방법을 사용하여 각 혼합물의 전단 반사균열 저항 특성을 비교 분석하였다. 그 결과 본 연구에서 개발한 실험방법을 사용하여 측정한 전단 반사균열 저항 특성이 재료 및 보강 효과의 차이를 적절히 보여 현장에서의 상황을 잘 모사할 수 있을 것으로 판단된다. 또한 일부 혼합물에 대하여 기존 피로수명 예측모델을 이용하여 전단 파괴수명을 예측한 결과 높은 상관성을 보여 향후 포장의 수명을 상대적으로 예측하는 것이 가능할 것으로 기대된다. This study was conducted to develop a test system for evaluating resistance against reflection cracking in shear mode caused by wheel load in asphalt concrete overlaid on the deteriorated cement concrete pavement. Reflection cracking resistance of selected polymer modified asphalt(PMA) mixtures with and without reinforcement was evaluated using this test system. It was shown that the test results accounted for the effectiveness of materials and reinforcement characteristics in terms of the difference in the resistance against reflection cracking. A shear failure life of a certain mixture was estimated with a high coefficient of determination. when the test results were used in a well known prediction model. Therefore, it seemed to be possible to use this technique for predicting a relative service life of on overlay.

개질재.보강재를 이용한 덧씌우기 아스팔트 포장의 반사균열 지연 효과

김광우,도영수,임성빈,이석근,엄주용,Kim, Kwang-Woo,Doh, Young-Soo,Lim, Sung-Bin,Rhee, Suk-Keun,Eum, Joo-Yong 한국도로학회 1999 한국도로포장공학회 논문집 Vol.1 No.1

본 연구는 아스팔트 콘크리트 덧씌우기에서 야기되는 반사균열에 대한 저항성을 향상시키기 위하여 개질재 및 보강재를 사용하여 제조한 혼합물의 성능을 평가하기 위하여 수행하였다. 아스팔트 개질재로는 LDPE와 SBS 및 카본블랙을 이용하였고. 보강재로는 합성섬유(PF), 비닐(PV), 그리드(GG)를 이용하였다. 배합설계를 통해 얻은 최적아스팔트 함량으로 아스팔트 혼합물 슬래브를 제조하였다. 아스팔트 혼합물을 몰드에 붓기 전에 몰드 바닥에 비닐이나 그리드를 미리 깔아 보강 층으로서 만들었다. 갭(균열)이 있는 시멘트 콘크리트 위에 부착된 아스팔트 혼합물 공시체에 유압식 동적하중기를 이용하여 반복하중을 재하하였다. 반복하중에서 균열진전을 측정하여 각 처리 혼합물의 균열 지연효과를 평가하였다. 본 연구의 시험 결과로부터 특정 조합의 아스팔트 혼합물이 휨 파괴(Mode I)에 의한 반사균열 지연에 상당히 효과적인 것으로 나타났다. This study was performed to evaluate performance of polymer-modified asphalt mixtures and specially designed reinforcement techniques against reflection cracking of the asphalt pavement overlay. Selected polymers were used for asphalt modification and polyester fiber, a polypropylene film (vinyl) and a grid were used for mixture reinforcement. Using the asphalt mixture with optimum asphalt content, a slab was made and cut into two pieces of specimen. A layer of grid or vinyl was placed at the bottom of specimen to strengthen the pavement layer against crack. A repeated loading was applied to the asphalt mixture specimen which is Placed on a cement concrete with a pseudo-crack. Crack propagation under repeated loading was monitored and effectiveness of the devised crack retarding techniques was evaluated. From the test results. a significant retardation of mode I crack progress was monitored from some of the modified and reinforced asphalt mixtures.

대학병원 경영평가지표 개발

김광우,윤인희,Kim, Gwang-U,Yun, In-Hui 대한병원협회 1985 대한병원협회지 Vol.14 No.11

도로포장용 재생콘크리트의 피로저항 특성

김광우,김성태,김대영,조문진 한국도로학회 2003 한국도로학회 학술대회 발표논문 초록집 Vol.2003 No.10

GPC를 이용한 재생 아스팔트 혼합물내의 바인더 불균등노화 상태 분석

김광우,홍상기,김민수,이기호 한국도로학회 2003 한국도로학회 학술대회 발표논문 초록집 Vol.2003 No.10

혈중 Colloid Oncotic Pressure 가 심폐혈관종에 미치는 환경에 관한 실험적 연구

김광우 대한마취과학회 1980 Korean Journal of Anesthesiology Vol.13 No.2

20 of mongrel dogs induced hemorrhagic hypotensive state by bleeding through fernoral artery with one third of cardiac output, and divided into two experimental groups; one for autologous autotransfusion and the other for normovolemic hemodilution with infusion of 200c.c. of Hartmann's solution, and hypervolemic hemodilution with infusion of 800c.c. of Hartmann's solution. 4 channel monitor(Space lab Inc.) was recorded for electrocardiogram, mean artery pressure(MAP) by cannulation in femoral artery, mean central venous pressure(CVP), mean pulmonary artery pressure(PAP), and mean pulmonary capillary wedge pressure (PCWP) by IL 5F-thermal dilution catheter. Cardiac output was measured with IL 701-702 cardiac output computer system (Instrumentation Laboratory Inc.) connected IL thermaI dilution catheter by thermodilution principle. Colloid oncotic pressure(COP) was measured with IL 186 Weil oncometer system. We evaluated significances of COP and COP-PCWP gradient in various status of bleeding, autologous retransfusion, acute normovolemic and hypervolemic hemodilution with surveying cardiopulmonary hemodynamic changes in dogs. Results were followings; A) Autologous retransfusion study. Average MAP decreased from 138 torr to 70 torr by bleeding of 260 c.c. blood and increased to 118 torr by retransfusion of shed blood. During hemorrhagic hypotensive state, average values of CVP (6±0. 12 torr), PAP (16±0. 23 torr) PCWP (80±0.8 torr), CO (0.5±0.03 L/min), SVR(10,240±67.5 dyne*sec/cm(5)) and COP (15.7±0.2 torr) were significantly decreased than mean control values of CVP(9±0.08 torr), PAP(18±0.14 torr), PCWP(11±0.15 torr), .and CO(0.8±0.004L/min) (p$lt;0.005). Average values of PVR(1,280±7.28dyne*sec/cm(5))and PVR/SVR ratio(0.13)in hypotensive state were increased than those of control values(respectively, 700±5.25 dyne*sec/cm(5), 0.05) with minimal increased COP-PCWP gradient(from 7.6 torr as control, 7.7 torr after bleeding). After autologous retransfusion in same amounts. average values of CVP (8±0.1 torr),27 torr), PCWF(13±0.19 torr), CO(1.0±0.01L/mn), and COP(17.9±0.23 torr) were increased than those of after bleeding. Average values of SVR(9,440+58,2 dyne sec/cm), PVR(880±4.28 dyne*sec/cm), PVR/SVR ratio(0.09) and COP-PCWP gradient(+6.9) were decreased than those after bleeding. Average values of PVR and PVR/SVR ratio were larger than those of control. B) Acute normovolemic and hypervolemic hemodilution study by infusion of 200c.c. and 800 c.c. of Hartmann's solution. Average values of MAP decreased from control value of 170 torr to 74 torr by average 200c.c. of bleeding(1/3 of CO)and increased to 16l torr by infusion of 200c.c. of Hartmann's solution and then changed to 120 torr by infusion of 800c.c. of Hartmann's solution(p$lt;0.005). After infusion of 200c.c. of Hartmanns solution, average value of CVP(12±0.15 torr), PAP (28±0.33 torr), PCWP (100±0.08 torr), CO(0.7±0.008 L/min) and SVR (17, 028±90.2 dyne*sec/cm') were larger than those after bleeding; CVP (11±0.13 torr) PAP (16±0. 23 torr), PCWP r) CO (0.4±0.002 L/min) and SVR (12, 600$gt;70. 8 dyne*sec/cm) (p$lt;0.005). Among above average values after infusion of 200 c.c. of Hartmanns solution, PAP is only the value larger than the control value, and remainders were same or smaller than the control value. Average values of PVR(2,057±14.32 dyne* sec/cm) and PUR/SVR ratio(0.12) were smaller than those after bleeding; PVR(2,200±15.33 dyne*sec/cm) and PVR/SVR ratio(0. 18). After infusion of 800 c.c. of Hartmann's soltuion, average alues of CVP (17±0.20 torr), PAP(31±0.05 torr), PCWP(15±0.12 torr), CO (2.1±0.009L/min) were larger than those of control and after bleeding and 200c.c. of infusion of Hartmanns solution(p$lt;0.005). PVR(609±8.44 dyne*sec/cm) and SVR(S,924±35, 3 dyne sec/cm) were decreased from the state of 200 c.c. of infusion of Hartmanns solution(p$lt;0.005) with larger value of PVR/SVR ratio(0.15). Average values of COP (12.1±0. 13 torr) and COP-PCWP gradient(2.1 torr) were gradually decreased with increased amounts of infused Hartmann's so.005).